Laminated-type multi-joint portion drive mechanism and manufacturing method therefor, grasping hand and robot arm provided with the same

Abstract

A laminated-type multi-joint portion drive mechanism includes a bone member having at least two elastic deformation portions, a laminated-type pneumatic tube member having at least two-line tubes which are stacked on the bone member and which are connected to a pneumatic drive source, and a planar-type joint-portion deformation member which is stacked on the laminated-type pneumatic tube member and which are placed at joint portions confronting the deformation portions, respectively, and which are connected to the tubes, in which when pneumatic pressure is applied to pneumatic operation chamber, the joint portion corresponding to the pneumatic operation chamber to which the pneumatic pressure is applied is deformable.

Description

TECHNICAL FIELD

The present invention relates to a laminated-type multi-joint portion drive mechanism having a multi-joint portion and a manufacturing method therefor, a grasping hand and a robot arm provided with the same, as well as a robot provided with the grasping hand and the robot arm. In particular, the present invention relates to a laminated-type multi-joint portion drive mechanism and a manufacturing method therefor, as well as a grasping hand and a robot arm provided with the same, which mechanism. fulfills the grasping of various kinds of and diverse objects, the safety for persons who use the mechanism, and the flexible operation, and which mechanism is easily manufacturable with low cost.

BACKGROUND ART

Conventionally, the grasping hand with a multi-joint portion drive mechanism has been used for the grasping of particular components in a limited working environment of factory inside primarily as a hand of industrial robots, and has been under discussions and contrivance in view of higher precision, higher speed, and the like for specialized operations. In recent years, in contrast to this, there has been brisk development on the robot introduction in household aid and work aid, care aid for the aged or the physically challenged, and the like in home, hospitals, and the like, giving rise to a desire for a grasping hand which satisfies such conditions as the grasping of various and diverse objects, which could not be implemented by industrial robots, and the safety to persons who use the grasping hand and which is capable of fulfilling flexible operations. For the grasping of diverse objects, there has been known a robot hand described in Japanese Patent No. 3245095. This robot hand has five fingers consisting of 4-degree-of-freedom thumb having one 4-joint-portion and 3-degree-of-freedom four fingers each having 4-joint-portion, where miniature servomotors are contained at joint portions other than the finger-tip first joint portion, respectively, to drive the joint portions.

However, this robot hand, involving large numbers of component parts, requiring assembly and being high-priced, is still limited to research use for the present.

With regard to the grasping hand capable of fulfilling flexible operations, a pneumatic actuator, which is one constituent element, is known as described in Japanese Patent No. 3226219. This actuator is so designed that a plurality of partition walls are provided in a cylindrical elastic member to define pressure chambers, each of the pressure chambers is to be pressurized to flex the elastic member. This actuator is combined in a plurality to form a grasping hand, thus being enabled to grasp objects.

However, since there is provided no constituent element equivalent to the human bone, there would arise an issue that it may become hard for the actuator to keep grasping a grasping object depending on its configuration and weight. Also, in order to drive each actuator, there would arise a need for drive tubes of a number corresponding to the number of internal pressure chambers of the cylindrical elastic members. In this case, the number of tubes would increase, causing a load more than the flexural operation force of the actuators to be involved depending on the rigidity of the tubes, posing a possibility that the actuators might no longer flex enough.

With regard to these already reported grasping hands, there has been disclosed no grasping hand which comprises pneumatic pressure as a drive source and which includes a laminated-type pneumatic tube formation member, a planar-type joint-portion flexural deformation member and a bone member having a joint portion according to the present invention.

For introduction of robots for performing various kinds of aid into human living space, there is a need for a multi-joint portion drive mechanism for fulfilling a grasping hand that serves as a main part for aid operation. Also, the grasping hand provided with the multi-joint portion drive mechanism is required to have a grasping performance for grasping various and diverse objects and to be safe, simple in structure, and implementable with low cost.

An object of the present invention is to provide a laminated-type multi-joint portion drive mechanism, as well as a manufacturing method therefor, and further to provide a grasping hand and a robot arm provided with the laminated-type multi-joint portion drive mechanism as well as a robot provided with the grasping hand and the robot arm each of which solves the foregoing issues and each of which is capable of implementing a grasping hand having a grasping performance for various and diverse objects, safe and simple in structure and implementable with low cost.

DISCLOSURE OF INVENTION

In accomplishing the above object, the present invention has the following constitution.

According to a first aspect of the present invention, there is provided a laminated-type multi-joint portion drive mechanism comprising:

a pneumatic drive source for pneumatic pressure;

a bone member having at least two elastically-deformable elastic deformation portions;

a laminated-type pneumatic tube member having at least two-line tubes which are fixed so as to be laid on the bone member and which are connected to the pneumatic drive source; and

a planar-type joint-portion flexural deformation member which is fixed so as to be laid on the laminated-type pneumatic tube member and which has pneumatic operation chambers placed at joint portions confronting the elastic deformation portions of the bone member, respectively, and connected to the tubes, respectively, wherein with pneumatic pressure applied to the pneumatic operation chamber, the joint portion corresponding to the pneumatic operation chamber to which the pneumatic pressure is applied is deformable.

According to a sixth aspect of the present invention, there is provided a method for manufacturing the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects, the method comprising:

integrally molding the bone member having elastic hinges at at least the elastic deformation portions; and

stacking and bonding the laminated-type pneumatic tube member and the planar-type joint-portion flexural deformation member on the bone member.

According to a seventh aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects which is arranged face to face to be capable of grasping an object.

According to an eighth aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects.

According to a ninth aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects, and providing the grasping hand as defined in the seventh aspect at an end of the robot arm.

According to a 21st aspect of the present invention, there is provided a robot comprising: the robot arm which comprises the laminated-type multi-joint portion drive mechanism as defined in the first or second aspect; and the grasping hand as defined in the 10th aspect provided at an end of the robot arm.

BRIEF DESCRIPTION OF DRAWINGS

These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:

FIG. 1 is a sectional view of a laminated-type multi-joint portion drive mechanism according to a first embodiment of the present invention;

FIGS. 2A, 2B, 2C are a perspective view, a side view and an explanatory view, respectively, of a bone member in which an elastic hinge portion is provided at each joint portion of the laminated-type multi-joint portion drive mechanism according to the first embodiment;

FIGS. 3A and 3B are an exploded perspective view of constituent elements of a laminated-type pneumatic tube formation member of the laminated-type multi-joint portion drive mechanism according to the first embodiment, and a schematic enlarged sectional view of the laminated-type pneumatic tube formation member, respectively;

FIGS. 4A, 4B, 4C, 4D, 4E and 4F are sectional views, respectively, of the laminated-type pneumatic tube formation member for explaining fabrication processes of the laminated-type pneumatic tube formation member of the laminated-type multi-joint portion drive mechanism according to the first embodiment;

FIGS. 5A and 5B are an exploded perspective view of constituent elements of a planar-type joint-portion flexural deformation member of the laminated-type multi-joint portion drive mechanism according to the first embodiment, and an enlarged partial sectional view of the planar-type joint-portion flexural deformation member, respectively;

FIGS. 6A and 6B are a sectional view of a model for explaining a drive state of a joint portion in a case where a constrained layer of the planar-type joint-portion flexural deformation member of the laminated-type multi-joint portion drive mechanism according to the first embodiment is not restricted to any particular direction for its direction of expansion and contraction, and a sectional view of a model for explaining a drive state of the joint portion in a case where the constrained layer is restricted to a particular direction for its direction of expansion and contraction, respectively;

FIGS. 7A and 7B are plan views of a constrained layer in which fiber is knitted, and a model representing expansion and contraction in a case where pneumatic pressure is applied to the constrained layer, respectively;

FIG. 8 is a sectional view of a model for explaining a drive state of a joint portion in a case where the constrained layer of a planar-type joint-portion flexural deformation member of the laminated-type multi-joint portion drive mechanism according to the first embodiment is restricted to a particular direction for its direction of expansion and contraction;

FIG. 9 is a block diagram for explaining control operation of the laminated-type multi-joint portion drive mechanism according to the first embodiment;

FIG. 10 is a perspective view of a model in a case where the constrained layer of each planar-type joint-portion flexural deformation member of a grasping hand provided with a pair of planar-type joint-portion flexural deformation members according to a second embodiment of the present invention is restricted to a particular direction for its direction of expansion and contraction and where a bone member having an elastic hinge at each joint portion is provided;

FIG. 11 is a block diagram for explaining control operation of the grasping hand of FIG. 10;

FIG. 12 is a perspective view of a model in a case where the constrained layer of each planar-type joint-portion flexural deformation member of a grasping hand provided with two pairs of planar-type joint-portion flexural deformation members according to a modification of the second embodiment of the present invention is restricted to a particular direction for its direction of expansion and contraction and where a bone member having an elastic hinge at each joint portion is provided;

FIG. 13 is a block diagram for explaining control operation of the grasping hand of FIG. 12;

FIG. 14 is a perspective view of a model of a grasping hand in which laminated-type multi-joint portion drive mechanisms are provided left-and-right asymmetrically according to another modification of the second embodiment of the present invention;

FIG. 15 is a perspective view of a grasping hand in which a laminated-type multi-joint portion drive mechanism having a sensor on the grasping surface side according to yet another modification of the second embodiment of the present invention is provided;

FIG. 16 is a block diagram showing grasping operation of the grasping hand of FIG. 15;

FIG. 17 is a plan view showing a neutral state of the grasping hand of FIG. 15;

FIGS. 18A and 18B are a plan view showing a neutral state of the grasping hand of FIG. 15 before its grasping an object, and a plan view showing the grasping hand of FIG. 15 that is grasping an object, respectively;

FIGS. 19A and 19B are a plan view showing a neutral state of the grasping hand of FIG. 15 before its grasping an object, and a plan view showing the grasping hand of FIG. 15 that is grasping an object, respectively;

FIGS. 20A and 20B are a plan view showing a neutral state of the grasping hand of FIG. 15, and a plan view showing a state of the grasping hand of FIG. 15 that has broadened the opening distance more than in the neutral state, respectively;

FIG. 21 is a plan view showing the grasping hand of FIG. 15 that is grasping an object in FIG. 20B; and

FIG. 22 is a perspective view of a robot which uses a laminated-type multi-joint portion drive mechanism according to a third embodiment of the present invention and in which the laminated-type multi-joint portion drive mechanism of FIG. 1 is provided with the grasping hand of FIG. 12 according to the second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.

Hereinbelow, a first embodiment of the present invention is described in detail with reference to the accompanying drawings.

Before the embodiment is described below in detail with reference to the accompanying drawings, various aspects of the present invention is first described.

According to a first aspect of the present invention, there is provided a laminated-type multi-joint portion drive mechanism comprising:

a pneumatic drive source for pneumatic pressure;

a bone member having at least two elastically-deformable elastic deformation portions;

a laminated-type pneumatic tube member having at least two-line tubes which are fixed so as to be laid on the bone member and which are connected to the pneumatic drive source; and

a planar-type joint-portion flexural deformation member which is fixed so as to be laid on the laminated-type pneumatic tube member and which has pneumatic operation chambers placed at joint portions confronting the elastic deformation portions of the bone member, respectively, and connected to the tubes, respectively, wherein with pneumatic pressure applied to the pneumatic operation chamber, the joint portion corresponding to the pneumatic operation chamber to which the pneumatic pressure is applied is deformable.

With this constitution, the laminated-type multi-joint portion drive mechanism has a function of, by taking advantage of flexible drive that is an advantage of conventional pneumatic actuators and by overcoming the complexities of tubing, making it possible to realize a joint-portion drive mechanism which is smaller-size, more lightweight, and easier to manufacture as compared with actuators typified by motors, and to achieve an improvement in the grasping rigidity by virtue of its having the bone member.

According to a second aspect of the present invention, there is provided the laminated-type multi-joint portion drive mechanism as defined in the first aspect, wherein the laminated-type pneumatic tube member is so formed that a plurality of molded organic films are stacked one on another to form the tubes.

With this constitution, the laminated-type multi-joint portion drive mechanism has a function of making it easier to manufacture the laminated-type multi-joint portion drive mechanism and making it possible to achieve a cost reduction by virtue of its adopting a laminated structure of tubes which otherwise might affect the drive of the joint portions because of their complications in making up a drive mechanism using pneumatic pressure.

According to a third aspect of the present invention, there is provided the laminated-type multi-joint portion drive mechanism as defined in the first or second aspect, wherein the planar-type joint-portion flexural deformation member comprises a constrained layer for imparting a directivity of expandability and contractibility to the planar-type joint-portion flexural deformation member along its longitudinal direction, wherein when the joint portions of the planar-type joint-portion flexural deformation member are expanded, a flexural operation is performed by guide of the bone member.

With this constitution, the laminated-type multi-joint portion drive mechanism has a function of making it possible to transform energy, which is supplied to the joint-portion drive mechanism utilizing pneumatic pressure, into flexural operation of the joint portions with high efficiency.

According to a fourth aspect of the present invention, there is provided the laminated-type multi-joint portion drive mechanism as defined in any one of the first to third aspects, wherein the plurality of elastic deformation portions of the bone member are elastic hinge portions, respectively.

With this constitution, the laminated-type multi-joint portion drive mechanism has a function of making it possible to integrally manufacture the multi-joint portions, or even a multi-finger configuration, by machining the joint portions alone into an elastic-hinge configuration, other than individually manufacturing the respective joint portions of the bone member that has a plurality of joint portions.

According to a fifth aspect of the present invention, there is provided the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fourth aspects, wherein the constrained layer of the planar-type joint-portion flexural deformation member is a flexible organic film material in which reticulate fiber is knitted.

With this constitution, the laminated-type multi-joint portion drive mechanism has a function of making it possible to transform energy, which is supplied to the pneumatic pressure source, into flexural operation of the joint portions with high efficiency by restricting the direction of expansion and contraction of the planar-type joint-portion flexural deformation member to a particular direction by means of reticulate fiber.

According to a sixth aspect of the present invention, there is provided a method for manufacturing the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects, the method comprising:

integrally molding the bone member having elastic hinges at at least the elastic deformation portions; and

stacking and bonding the laminated-type pneumatic tube member and the planar-type joint-portion flexural deformation member on the bone member.

With this constitution, the laminated-type multi-joint portion drive mechanism is manufactured through the processes of molding the layers layer by layer and tightly bonding together the layers. Therefore, the laminated-type multi-joint portion drive mechanism has a function of making it possible to manufacture the laminated-type multi-joint portion drive mechanism with low cost by virtue of suppressing the component parts count to the least.

According to a seventh aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects which is arranged face to face to be capable of grasping an object.

With this constitution, the grasping hand has a function of making it possible to achieve grasping of various and diverse objects, the safety to persons who use the grasping hand and flexible operation.

According to an eighth aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects.

With this constitution, the robot arm is enabled to achieve safety to persons who use the robot arm as well as flexible positioning operation.

According to a ninth aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in any one of the first to fifth aspects, and providing the grasping hand as defined in the seventh aspect at an end of the robot arm.

With this constitution, since the grasping hand, in which the laminated-type multi-joint portion drive mechanism is arranged face to face, is provided at an end of the robot arm, the robot arm is enabled to safely position the grasping hand against an grasping object located within a movable range, thus making it possible to achieve safety to persons who use the robot arm as well as flexible positioning operation.

According to a 10th aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in the first or second aspect which is arranged face to face to be capable of grasping an object.

According to an 11th aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in the third aspect which is arranged face to face to be capable of grasping an object.

According to a 12th aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in the fourth aspect which is arranged face to face to be capable of grasping an object.

According to a 13th aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in the fifth aspect which is arranged face to face to be capable of grasping an object.

According to a 14th aspect of the present invention, there is provided a grasping hand having the laminated-type multi-joint portion drive mechanism as defined in the sixth aspect which is arranged face to face to be capable of grasping an object.

According to a 15th aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in the first or second aspect.

According to a 16th aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in the third aspect.

According to a 17th aspect of the present invention, there is provided a robot arm using the laminated-type multi-joint portion drive mechanism as defined in the fourth aspect.

According to a 18th aspect of the present invention, there is provided a robot arm providing the grasping hand as defined in the 10th aspect at an end of the arm.

According to a 19th aspect of the present invention, there is provided a robot arm providing the grasping hand as defined in the 11th aspect at an end of the arm.

According to a 20th aspect of the present invention, there is provided a robot arm providing the grasping hand as defined in the 12th aspect at an end of the arm.

According to a 21st aspect of the present invention, there is provided a robot comprising: the robot arm which comprises the laminated-type multi-joint portion drive mechanism as defined in the first or second aspect; and the grasping hand as defined in the 10th aspect provided at an end of the robot arm.

Hereinbelow, embodiments of the present invention are explained with reference to FIGS. 1 to 22.

(First Embodiment)

FIG. 1 is a sectional view of a laminated-type multi-joint portion drive mechanism according to a first embodiment of the present invention. The laminated-type multi-joint portion drive mechanism shown in FIG. 1 is formed through the steps of stacking a plate-shaped laminated-type pneumatic tube formation member 2 and a planar-type joint-portion flexural deformation member 3 on a bone member 1 having elastic hinge portions 1A provided at a plurality of joint portions, respectively, and then tightly joining them by adhesively bonding them together with an adhesive such as polyimide-based adhesive. This multi-joint portion drive mechanism includes a pneumatic drive source 4 such as an air cylinder for feeding compressed air or the like, a pneumatic pressure introduction tube 5 for implementing a pneumatic introductory tube connected to the pneumatic drive source 4, a laminated-type pneumatic tube formation member 2 having gas passage through holes 2g, 2h, 2i connected to the pneumatic pressure introduction tube 5 via a plurality of tubes 2a, 2b, 2c having solenoid valves 17a, 17b, 17c, respectively, and a planar-type joint-portion flexural deformation member 3 tightly joined with the laminated-type pneumatic tube formation member 2, where pneumatic pressure is applied from the pneumatic drive source 4 to the gas passage through holes 2g, 2h, 2i of the laminated-type pneumatic tube formation member 2 so that the planar-type joint-portion flexural deformation member 3 is expanded, thus achieving flexure of the joint portions flexed with the elastic hinge portions 1A of the bone member 1 serving as flexure points.

Referring to FIGS. 1 and 2C, the bone member 1 includes a first bone member body portion 1B-1, a first elastic hinge portion 1A-1, a second bone member body portion 1B-2, a second elastic hinge portion 1A-2, a third bone member body portion 1B-3, a third elastic hinge portion 1A-3, and a fourth bone member body portion 1B-4, these members being arranged and connected in adjacency to one another from the base end portion side of the bone member 1 toward the fore end portion side thereof. In the following description, when a description is common to the first to fourth bone member body portions 1B-1 to 1B-4, the description is made with representation by the bone member body portions 1B, and likewise when a description is common to the first to third elastic hinge portions 1A-1 to 1A-3, the description is made with representation by the elastic hinge portions 1A. The elastic hinge portions 1A are formed thinner and thus elastically deformable, as compared with the bone member body portions 1B.

In the bone member 1, although the elastic hinge portions 1A are provided three in number so that the number of joint portions of the laminated-type multi-joint portion drive mechanism is set as three joint portions, the number of joint portions may be changed depending on the environment and objects with which this laminated-type multi-joint portion drive mechanism is put into use. Also, the width of the laminated-type multi-joint portion drive mechanism or the length of the individual member portions may also be changed likewise.

The laminated-type multi-joint portion drive mechanism is explained in its structure with reference to its manufacturing procedure.

FIGS. 2A and 2B are a perspective view and a sectional view, respectively, of the bone member 1 in which an elastic hinge portion 1A is provided at each joint portion of the laminated-type multi-joint portion drive mechanism. The bone member 1 is characterized by using high-rigidity, lightweight organic material (e.g., polyethylene terephthalate or polypropylene) and integrally molding its external configuration, the elastic hinge portions 1A, and the bone member body portions 1B. It is noted that the elastic hinge portion 1A refers to a portion of the bone member 1 which serves for flexure of the bone member 1 and which is molded so as to be about ½ to ¼ as thick as the bone member body portion 1B. In this embodiment of the present invention, whereas use of a single material for the integral molding of the bone member 1 makes the elastic hinge portions 1A and the bone member body portions 1B equal in modulus of elasticity to each other, it is possible to make the elastic hinge portions 1A preferentially flexed to the bone member body portions 1B due to a thickness difference therebetween. An example of the material of the bone member 1 is polypropylene. Polypropylene can be considered to be capable of improving the reliability of the multi-joint portion drive mechanism that requires iterative operations because the material of polypropylene itself has hinge property and high reiterative flexural strength. An example of the integral molding of the bone member 1 is a molding using a metal mold. Molding a large-width plate material and thereafter cutting and separating the material at desired widths allows a multiplicity of bone members 1 to be molded and manufactured with ease. As another manufacturing method for the bone member 1, there is listed a thermal process of plate material, where material texture of the elastic hinge portions 1A becomes dense by forming the elastic hinge portions 1A by heating and compression, providing a possibility that the reiterative flexural strength of the joint portions can also be improved. FIG. 2C is a perspective view showing dynamic characteristics of the elastic hinge portions 1A. The bone member 1, which is so configured that the individual bone member body portions 1B are connected to one another with the elastic hinge portions 1A serving as joint portions, a force 6 in a Z-axis direction applied to the bone member 1 can be supported as a moment force 7 on the base end side of the bone member 1. Properties of this moment force 7 are effective regardless of the flexural angle of the elastic hinge portions 1A under the condition of high torsional rigidity of the elastic hinge portions 1A and moreover independent of a force generated by the planar-type joint-portion flexural deformation member 3. As a result of these characteristics, as shown in FIG. 10, when a pair of laminated-type multi-joint portion drive mechanisms are arranged face to face like a hand, a force generated along a gravity drop direction (the Z-axis direction of FIG. 2C) of a grasping object which is vertical to a grasping direction (a direction perpendicular to both Z-axis direction and X-axis direction of FIG. 2C, i.e., a thicknesswise direction of the bone member 1) can be supported by the structural strength of the bone member 1, so that energy supplied from the pneumatic drive source 4 can efficiently be transformed into grasping force.

FIGS. 3A and 3B show an exploded perspective view of organic films 2A, 2B, 2C, which are constituent elements of the laminated-type pneumatic tube formation member 2 of the laminated-type multi-joint portion drive mechanism, and a sectional view of the laminated-type pneumatic tube formation member 2 after the stacking of the organic films 2A, 2B, 2C. The laminated-type pneumatic tube formation member 2, as shown in FIG. 3A, is formed from the organic films 2A, 2B, 2C which are identical in configuration to the bone member 1 and identical in configuration among the three and which are tightly stacked one on another. That is, on a first organic film 2A that serves as a base material, a second organic film 2B in which a tube is to be provided is tightly joined, then tube shaping process is performed by photolithography or the like, and a third organic film 2C is tightly joined thereon, followed by forming through holes for introduction of pneumatic pressure into the planar-type joint-portion flexural deformation member 3. Thus, the second organic film 2B has three tubes 2a, 2b, 2c which extend in parallel to one another and along the longitudinal direction of the laminated-type pneumatic tube formation member 2 so as to penetrate in its thicknesswise direction. The first laminated-type pneumatic tube 2a is the shortest, where a first circular gas supply hole 2d which has a diameter larger than the tube width and which penetrates in the thicknesswise direction is formed at a distal end of the tube. The second laminated-type pneumatic tube 2b is longer than the first laminated-type pneumatic tube 2a, where a circular gas supply hole 2e which has a diameter larger than the tube width and which penetrates in the thicknesswise direction is formed at a distal end of the tube. The third laminated-type pneumatic tube 2c is longer than the second laminated-type pneumatic tube 2b, where a circular gas supply hole 2f which has a diameter larger than the tube width and which penetrates in the thicknesswise direction is formed at a distal end of the tube.

Also, the first organic film 2A is formed into a plate shape in which through holes are not formed at all.

Meanwhile, near the base end portion of the third organic film 2C is formed a first circular gas passage through hole 2g which communicates with the first circular gas supply hole 2d of the second organic film 2B and which is larger in diameter than the first circular gas supply hole 2d and which penetrates in the thicknesswise direction. At an intermediate portion between the base end portion and the distal end portion is formed a second circular gas passage through hole 2h which communicates with the second circular gas supply hole 2e of the second organic film 2B and which is larger in diameter than the second circular gas supply hole 2e and which penetrates in the thicknesswise direction. At an intermediate portion between the base end portion and the distal end portion is formed a third circular gas passage through hole 2i which communicates with the third circular gas supply hole 2f of the second organic film 2B and which is larger in diameter than the third circular gas supply hole 2f and which penetrates in the thicknesswise direction.

Accordingly, the individual tubes 2a, 2b, 2c of the second organic film 2B are formed as passages between the third organic film 2C and the first organic film 2A.

As an example of fabrication of this laminated-type pneumatic tube formation member 2, a fabrication flow with polyimide film and photosensitive polyimide used as the material is shown in FIGS. 4A to 4F. First, a polyimide film (see FIG. 4A), which forms the first organic film 2A, as a base material, is coated with photosensitive polyimide, which forms the second organic film 2B (see FIG. 4B). This coating is followed by pre-baking, and thereafter the photosensitive polyimide is exposed to light with a photomask 8 having a tube pattern corresponding to the tubes 2a, 2b, 2c (see FIG. 4C), then, development and post-baking are performed to form the tubes 2a, 2b, 2c (see FIG. 4D). On the resulting film, a polyimide film with an adhesive thereon as the third organic film 2C is bonded in an airtight state (see FIG. 4E), and formation process for the first circular gas passage through hole 2g, the second circular gas passage through hole 2h, and the third circular gas passage through hole 2i, by which the tubes 2a, 2b, 2c and the planar-type joint-portion flexural deformation member 3 are connected to each other, is performed by laser beam machining with a laser beam 9 to form the laminated-type pneumatic tube formation member 2 (see FIG. 4F). Otherwise, the third organic film 2C, which is a polyimide film with adhesive attached and in which the first circular gas passage through hole 2g, the second circular gas passage through hole 2h, and the third circular gas passage through hole 2i have previously been formed, may be aligned and bonded in an airtight state on the second organic film 2B and the first organic film 2A, in which the tubes 2a, 2b, 2c have been formed. By arranging and forming the tubes 2a, 2b, 2c on a plane in such a manner, it becomes possible to integrally mold the tubes 2a, 2b, 2c for allowing the individual joint portions of the multi-joint portion drive mechanism to be operated independently of one another.

Between the tubes 2a, 2b, 2c and the pneumatic pressure introduction tube 5 are arranged solenoid valves, respectively, so that air supply into the tubes 2a, 2b, 2c can be made and halted independently and individually depending on the opening and closing of the solenoid valves.

FIGS. 5A and 5B show an exploded perspective view of a base member 3A, an elastic layer 3B, and a constrained layer 3C, which are constituent elements of the planar-type joint-portion flexural deformation member 3, and a sectional view of the planar-type joint-portion flexural deformation member 3 after the stacking of the base member 3A, the elastic layer 3B, and the constrained layer 3C. The planar-type joint-portion flexural deformation member 3 is so formed that an elastic layer 3B formed of an elastic material and having a rectangular first pneumatic operation hole 3g, a rectangular second pneumatic operation hole 3h, and a rectangular third pneumatic operation hole 3i formed therein so as to extend through the elastic layer 3B and to serve as voids that form pneumatic operation chambers 16 is hermetically bonded and joined on the base member 3A having a first circular gas supply hole 3d, a second circular gas supply hole 3e, and a third circular gas supply hole 3f which communicate with the first pneumatic operation hole 3g, the second pneumatic operation hole 3h, and the third pneumatic operation hole 3i, respectively and independently, and which are smaller in diameter than those, respectively, and further which extend through the base member 3A, and moreover the constrained layer 3C which is shaped into a flat plate with no through holes and which imparts a directivity to the expansion and contraction of the laminated-type multi-joint portion drive mechanism is hermetically bonded and joined thereon.

In this case, FIG. 6A is a sectional view of a model of joint portion drive in a case where the constrained layer 3C is not restricted in its direction of expansion and contraction thereof, representing a configuration resulting when the planar-type joint-portion flexural deformation member 3 is expanded upward, as viewed in FIG. 6A, by application of pneumatic pressure under that condition. In this case, the constrained layer 3C itself would preferentially expand due to the application of pneumatic pressure, inhibiting the flexural operation of an intended joint portion.

In contrast to this, FIG. 6B is a sectional view of a model of joint portion drive in a case where the expansion-and-contraction direction of the constrained layer 3C is restricted to one direction (i.e., the longitudinal direction of the constrained layer 3C), representing a configuration resulting when the planar-type joint-portion flexural deformation member 3 is expanded by application of pneumatic pressure under that condition. Like this, by the constrained layer 3C being expanded and contracted in one direction, it becomes possible to efficiently transform energy supplied from the pneumatic drive source 4 into flexural operation of the joint portion.

In order to restrict the extension-and-contraction direction of the constrained layer 3C to one direction, i.e., the longitudinal direction of the constrained layer 3C, it is effective to mold the constrained layer 3C with a flexible organic material in which fiber 10 has been knitted along a direction perpendicular to the extension-and-contraction direction of the constrained layer 3C as shown in FIG. 7A. FIG. 7B shows a plan view of a model representing an expanded state of the constrained layer 3C in which the fiber 10 has been knitted along a direction perpendicular to the extension-and-contraction direction in the case where pneumatic pressure is applied to the constrained layer 3C. The constrained layer 3C is expanded and contracted by the elasticity of the organic material in the direction (the left-and-right direction in FIGS. 7A and 7B, i.e., the longitudinal direction of the constrained layer 3C) perpendicular to the fiber 10 oriented along the up-and-down direction as viewed in FIGS. 7A and 7B, while an extension-and-contraction restrictive force due to the length of the fiber 10 acts along a direction parallel to the fiber 10 (the up-and-down direction in FIGS. 7A and 7B, i.e., the widthwise direction of the constrained layer 3C) so that the constrained layer 3C can be restricted in its expansion and contraction.

FIG. 8 is a sectional view of a model in the case where the constrained layer 3C is restricted to a particular direction of its expansion and contraction (i.e., the longitudinal direction of the constrained layer 3C) and where a bone member 1 having elastic hinges 1A at its joint portions is provided, the figure representing a configuration resulting when the planar-type joint-portion flexural deformation member 3 is expanded by application of pneumatic pressure under that condition. By virtue of the provision of the bone member 1 having the elastic hinges 1A at individual joint portions, respectively, in addition to the planar-type joint-portion flexural deformation member 3 that is driven by application of pneumatic pressure, the portions other than the joint portions are further constrained, thus producing an effect that the energy supplied from the pneumatic drive source 4 can be transformed into flexural operation of the joint portions more efficiently.

This flexural operation is described in detail. The first circular gas supply hole 2d and the first circular gas passage through hole 2g of the laminated-type pneumatic tube formation member 2 and the first circular gas supply hole 3d and the first pneumatic operation hole 3g of the planar-type joint-portion flexural deformation member 3 are connected together and arranged so as to confront the inner surface side of the first elastic hinge portion 1A-1. Then, pneumatic pressure, i.e., compressed air is supplied from the pneumatic drive source 4 to the first pneumatic operation hole 3g (first pneumatic operation chamber 16A) via the first laminated-type pneumatic tube 2a, the first circular gas supply hole 2d, the first circular gas passage through hole 2g, and the first circular gas supply hole 3d, by which a first joint portion 3a of the planar-type joint-portion flexural deformation member 3 near the first pneumatic operation chamber 16A is elastically deformed to extend along the longitudinal direction, so that the first bone member body portion 1B-1 and the second bone member body portions 1B-2 make the first elastic hinge portion 1A-1 flexed so as to be positioned inward.

Similarly, the second circular gas supply hole 2e and the second circular gas passage through hole 2h of the laminated-type pneumatic tube formation member 2 and the second circular gas supply hole 3e and the second pneumatic operation hole 3h of the planar-type joint-portion flexural deformation member 3 are connected together and arranged so as to confront the inner surface side of the second elastic hinge portion 1A-2. Then, pneumatic pressure, i.e., compressed air is supplied from the pneumatic drive source 4 to the second pneumatic operation hole 3h (second pneumatic operation chamber 16B) via the second laminated-type pneumatic tube 2b, the second circular gas supply hole 2e, the second circular gas passage through hole 2h, and the second circular gas supply hole 3e, by which a second joint portion 3b of the planar-type joint-portion flexural deformation member 3 near the second pneumatic operation chamber 16B is elastically deformed to extend along the longitudinal direction, so that the second bone member body portion 1B-2 and the third bone member body portion 1B-3 make the second elastic hinge portion 1A-2 flexed so as to be positioned inward.

Similarly, the third circular gas supply hole 2f and the third circular gas passage through hole 2i of the laminated-type pneumatic tube formation member 2 and the third circular gas supply hole 3f and the third pneumatic operation hole 3i of the planar-type joint-portion flexural deformation member 3 are connected together and arranged so as to confront the inner surface side of the third elastic hinge portion 1A-3. Then, pneumatic pressure, i.e., compressed air is supplied from the pneumatic drive source 4 to the third pneumatic operation hole 3i (third pneumatic operation chamber 16C) via the third laminated-type pneumatic tube 2c, the third circular gas supply hole 2f, the third circular gas passage through hole 2i, and the third circular gas supply hole 3f, by which a third joint portion 3c of the planar-type joint-portion flexural deformation member 3 near the third pneumatic operation chamber 16C is elastically deformed to extend along the longitudinal direction, so that the third bone member body portion 1B-3 and the fourth bone member body portion 1B-4 make the third elastic hinge portion 1A-3 flexed so as to be positioned inward.

The bone member 1, the laminated-type pneumatic tube formation member 2, and the planar-type joint-portion flexural deformation member 3, which are constituent elements, are bonded and joined together into a hermetic state, by which the laminated-type multi-joint portion drive mechanism of the first embodiment is fabricated.

A further description is given below on a case where the laminated-type multi-joint portion drive mechanism of the above construction is controlled for its drive by a control section 12. As shown in FIG. 9, the laminated-type multi-joint portion drive mechanism is placed and fixed to a fixing portion 11 with the root of the bone member 1 serving as a junction portion. The control section 12 controls the drive of the pneumatic drive source 4, and also controls the opening and closing of a first solenoid valve 17a interposed on the first laminated-type pneumatic tube 2a, the opening and closing of a second solenoid valve 17b interposed on the second laminated-type pneumatic tube 2b, and the opening and closing of a third solenoid valve 17c interposed on the third laminated-type pneumatic tube 2c. Further, the first pneumatic operation chamber 16A for driving the first joint portion 3a is provided by the first pneumatic operation hole 3g, where with air supplied to the first pneumatic operation chamber 16A, the first joint portion 3a is flexed about the first elastic hinge portion 1A-1 by the guide of the first bone member body portion 1B-1 and the second bone member body portion 1B-2 provided on both sides of the first elastic hinge portion 1A-1 as shown in FIG. 8. Also, the second pneumatic operation chamber 16B for driving the second joint portion 3b is provided by the second pneumatic operation hole 3h, where with air supplied to the second pneumatic operation chamber 16B, the second joint portion 3b is flexed about the second elastic hinge portion 1A-2 by the guide of the second bone member body portion 1B-2 and the third bone member body portion 1B-3 provided on both sides of the second elastic hinge portion 1A-2 as shown in FIG. 8. Also, the third pneumatic operation chamber 16C for driving the third joint portion 3c is provided by the third pneumatic operation hole 3i, where with air supplied to the third pneumatic operation chamber 16C, the third joint portion 3c is flexed about the third elastic hinge portion 1A-3 by the guide of the third bone member body portion 1B-3 and the fourth bone member body portion 1B-4 provided on both sides of the third elastic hinge portion 1A-3 as shown in FIG. 8.

Referring to operation of the multi-joint portion drive mechanism, first, the control section 12 acts to generate a signal for applying pneumatic pressure to the first pneumatic operation chamber 16A located at the first joint portion of the planar-type joint-portion flexural deformation member 3 of the multi-joint portion drive mechanism, and the pneumatic drive source 4 is driven and the first solenoid valve 17a is opened by the control section 12. As a result of this, air is supplied from the pneumatic drive source 4 to the first pneumatic operation hole 3g, i.e. the first pneumatic operation chamber 16A, via the first laminated-type pneumatic tube 2a, the first circular gas supply hole 2d, and the first circular gas supply hole 3d, so that air pressure, i.e., pneumatic pressure is applied to the first pneumatic operation chamber 16A. Along with this application of pneumatic pressure, the first pneumatic operation chamber 16A is expanded, causing the first joint portion to be flexed. To undo the flexure of the first joint portion, the drive of the pneumatic drive source 4 by the control section 12 is halted and the first solenoid valve 17a is opened, by which the expansion at the first pneumatic operation chamber 16A due to pneumatic pressure is released, so that the first joint portion is returned to the stretched state. Also, independent of the flexure of the first joint portion, the control section 12 acts to generate a signal for applying pneumatic pressure to the second pneumatic operation chamber 16B located at the second joint portion of the planar-type joint-portion flexural deformation member 3 of the multi-joint portion drive mechanism, and the pneumatic drive source 4 is driven and the second solenoid valve 17b is opened by the control section 12. As a result of this, air is supplied from the pneumatic drive source 4 to the second pneumatic operation hole 3h, i.e. the second pneumatic operation chamber 16B, via the second laminated-type pneumatic tube 2b, the second circular gas supply hole 2e, and the second circular gas supply hole 3e, so that air pressure, i.e.., pneumatic pressure is applied to the second pneumatic operation chamber 16B. Along with this application of pneumatic pressure, the second pneumatic operation chamber 16B is expanded, causing the second joint portion to be flexed. To undo the flexure of the second joint portion, the drive of the pneumatic drive source 4 by the control section 12 is halted and the second solenoid valve 17b is opened, by which the expansion at the second pneumatic operation chamber 16B due to pneumatic pressure is released, so that the second joint portion is returned to the stretched state. Further, independent of the flexure of the second joint portion, the control section 12 acts to generate a signal for applying pneumatic pressure to the third pneumatic operation chamber 16C located at the third joint portion of the planar-type joint-portion flexural deformation member 3 of the multi-joint portion drive mechanism, and the pneumatic drive source 4 is driven and the third solenoid valve 17c is opened by the control section 12. As a result of this, air is supplied from the pneumatic drive source 4 to the third pneumatic operation hole 3i, i.e. the third pneumatic operation chamber 16C, via the third laminated-type pneumatic tube 2c, the third circular gas supply hole 2f, and the third circular gas supply hole 3f, so that air pressure, i.e., pneumatic pressure is applied to the third pneumatic operation chamber 16C. Along with this application of pneumatic pressure, the third pneumatic operation chamber 16C is expanded, causing the third joint portion to be flexed. To undo the flexure of the third joint portion, the drive of the pneumatic drive source 4 by the control section 12 is halted and the third solenoid valve 17c is opened, by which the expansion at the third pneumatic operation chamber 16C due to pneumatic pressure is released, so that the third joint portion is returned to the stretched state.

According to the first embodiment, any arbitrary joint portion can be flexed securely by the opening-and-closing control of the solenoid valves 17a, 17b, 17c by the control section 12.

(Second Embodiment)

FIGS. 10 and 11 are a perspective view and a block diagram, respectively, of a grasping hand provided with the laminated-type multi-joint portion drive mechanism of the first embodiment, where a grasping function is given by providing a plurality, e.g., one pair of laminated-type multi-joint portion drive mechanisms face to face and left-and-right symmetrical. With the root of each bone member 1 serving as a junction portion, the laminated-type multi-joint portion drive mechanisms are placed and fixed at the fixing portion 11 so as to confront each other.

The control section 12 controls the drive of the pneumatic drive source 4, and also controls the opening and closing of first solenoid valves 17a, 17a interposed on left-and-right first laminated-type pneumatic tubes 2a, 2a, the opening and closing of second solenoid valves 17b, 17b interposed on left-and-right second laminated-type pneumatic tubes 2b, 2b, and the opening and closing of third solenoid valves 17c, 17c interposed on left-and-right third laminated-type pneumatic tubes 2c, 2c, respectively and independently. Further, the first pneumatic operation chambers 16A for driving the left-and-right first joint portions 3a, respectively, are provided by the first pneumatic operation holes 3g, where with air supplied to the first pneumatic operation chambers 16A, each first joint portion 3a is flexed about the first elastic hinge portion 1A-1 by the guide of the first bone member body portion 1B-1 and the second bone member body portion 1B-2 provided on both sides of the first elastic hinge portion 1A-1 as shown in FIG. 8. Also, the second pneumatic operation chambers 16B for driving the left-and-right second joint portions 3b are provided by the second pneumatic operation holes 3h, where with air supplied to the second pneumatic operation chambers 16B, the or each second joint portion 3b is flexed about the second elastic hinge portion 1A-2 by the guide of the second bone member body portion 1B-2 and the third bone member body portion 1B-3 provided on both sides of the second elastic hinge portion 1A-2 as shown in FIG. 8. Also, the third pneumatic operation chambers 16C for driving the left-and-right third joint portions 3c are provided by the third pneumatic operation holes 3i, where with air supplied to the third pneumatic operation chambers 16C, each third joint portion 3c is flexed about the third elastic hinge portion 1A-3 by the guide of the third bone member body portion 1B-3 and the fourth bone member body portion 1B-4 provided on both sides of the third elastic hinge portion 1A-3 as shown in FIG. 8.

Referring to operation of the multi-joint portion drive mechanism, first, the control section 12 acts to generate signals for applying pneumatic pressure, for example synchronously, to the first pneumatic operation chambers 16A, 16A located at left-and-right first joint portions of the planar-type joint-portion flexural deformation members 3, 3 of the left-and-right multi-joint portion drive mechanisms, and, by the control section 12, the pneumatic drive source 4 is driven and the left-and-right first solenoid valves 17a, 17a are synchronously opened. As a result of this, air is supplied from the pneumatic drive source 4 to the left-and-right first pneumatic operation holes 3g, 3g, i.e. the left-and-right first pneumatic operation chambers 16A, 16A, via the left-and-right first laminated-type pneumatic tubes 2a, 2a, the left-and-right first circular gas supply holes 2d, 2d, and the left-and-right first circular gas supply holes 3d, 3d, respectively and synchronously, so that air pressure, i.e., pneumatic pressure is applied to the left-and-right first pneumatic operation chambers 16A, 16A, respectively and synchronously. Along with this left-and-right synchronized application of pneumatic pressure, the left-and-right first pneumatic operation chambers 16A, 16A are expanded respectively and synchronously, causing the left-and-right first joint portions to be flexed synchronously. To undo the flexure of the left-and-right first joint portions, the drive of the pneumatic drive source 4 by the control section 12 is halted and the first solenoid valves 17a, 17a are opened, by which the expansion at the first pneumatic operation chambers 16A, 16A due to pneumatic pressure is released, so that the left-and-right first joint portions are returned to the stretched state. Also, independent of the flexure of the left-and-right first joint portions, the control section 12 acts to generate signals for applying pneumatic pressure, for example synchronously, to the second pneumatic operation chambers 16B, 16B located at the left-and-right second joint portions of the planar-type joint-portion flexural deformation members 3, 3 of the left-and-right multi-joint portion drive mechanisms, and, by the control section 12, the pneumatic drive source 4 is driven and the left-and-right second solenoid valves 17b, 17b are synchronously opened. As a result of this, air is supplied from the pneumatic drive source 4 to the left-and-right second pneumatic operation holes 3h, 3h, i.e. the left-and-right second pneumatic operation chambers 16B, 16B, via the left-and-right second laminated-type pneumatic tubes 2b, 2b, the left-and-right second circular gas supply holes 2e, 2e, and the left-and-right second circular gas supply holes 3e, 3e, respectively and synchronously, so that air pressure, i.e., pneumatic pressure is applied to the left-and-right second pneumatic operation chambers 16B, 16B synchronously. Along with this left-and-right synchronized application of pneumatic pressure, the left-and-right second pneumatic operation chambers 16B, 16B are expanded synchronously, causing the left-and-right second joint portions to be flexed synchronously. To undo the flexure of the left-and-right second joint portions, the drive of the pneumatic drive source 4 by the control section 12 is halted and the second solenoid valves 17b, 17b are opened, by which the expansion at the second pneumatic operation chambers 16B, 16B due to pneumatic pressure is released, so that the left-and-right second joint portions are returned to the stretched state. Further, independent of the flexure of the left-and-right second joint portions, the control section 12 acts to generate signals for applying pneumatic pressure, for example synchronously, to the third pneumatic operation chambers 16C, 16C located at the left-and-right third joint portions of the planar-type joint-portion flexural deformation members 3, 3 of the left-and-right multi-joint portion drive mechanisms, and, by the control section 12, the pneumatic drive source 4 is driven and the left-and-right third solenoid valves 17c, 17c are synchronously opened. As a result of this, air is supplied from the pneumatic drive source 4 to the left-and-right third pneumatic operation holes 3i, 3i, i.e. the left-and-right third pneumatic operation chambers 16C, 16C, via the left-and-right third laminated-type pneumatic tubes 2c, 2c, the left-and-right third circular gas supply holes 2f, 2f, and the left-and-right third circular gas supply holes 3f, 3f, respectively and synchronously, so that air pressure, i.e., pneumatic pressure is applied to the left-and-right third pneumatic operation chambers 16C, 16C synchronously. Along with this left-and-right synchronized application of pneumatic pressure, the left-and-right third pneumatic operation chambers 16C, 16C are expanded synchronously, causing the left-and-right third joint portions to be flexed. To undo the flexure of the left-and-right third joint portions, the drive of the pneumatic drive source 4 by the control section 12 is halted and the third solenoid valves 17c, 17c are opened, by which the expansion at the third pneumatic operation chambers 16C, 16C due to pneumatic pressure is released, so that the left-and-right third joint portions are returned to the stretched state.

According to the second embodiment, grasping operation can be carried out by reliably flexing arbitrary left-and-right joint portions by virtue of the opening-and-closing control of the left-and-right solenoid valves 17a, 17b, 17c by the control section 12.

As an modification of the second embodiment, FIGS. 12 and 13 are a perspective view and a block diagram, respectively, of a grasping hand provided with the laminated-type multi-joint portion drive mechanism of the first embodiment, where a grasping function is given by providing two pairs of laminated-type multi-joint portion drive mechanisms face to face and left-and-right symmetrical. With the root of each bone member 1 serving as a junction portion, the laminated-type multi-joint portion drive mechanisms are placed and fixed at the fixing portion 11 so as to confront each other. Operation of each laminated-type multi-joint portion drive mechanism is the same as in the foregoing second embodiment of FIG. 10 and therefore its description is omitted.

Although an even number, e.g. two, of the laminated-type multi-joint portion drive mechanisms are arranged left-and-right symmetrically in FIGS. 12 and 13, yet it is also possible that left-hand two laminated-type multi-joint portion drive mechanisms and right-hand one laminated-type multi-joint portion drive mechanism are provided left-and-right asymmetrically as shown in a perspective view of FIG. 14, as another modification of the second embodiment of the present invention, depending on the configuration of grasping objects. Operation of each laminated-type multi-joint portion drive mechanism is the same as in the foregoing second embodiment of FIG. 10 and therefore its description is omitted.

Moreover, the laminated-type multi-joint portion drive mechanisms to be provided in a plurality may also be set with their length and width changed in response to their working objects.

As yet another modification of the second embodiment of the present invention, as shown in the perspective view and the block diagram of FIGS. 15 and 16, four laminated-type multi-joint portion drive mechanisms are set left-and-right symmetrically, i.e. each two on the left and right, so that their base end portions are fixed to the fixing portion 11, and the pneumatic drive sources 4 are connected to the laminated-type multi-joint portion drive mechanisms via their respective pneumatic pressure introduction tubes 5, respectively, and the four pneumatic drive sources 4, . . . , 4 are controlled for its drive by the control section 12. Further, on the grasping surface side of each bone member 1 are placed a contact sensor 13 which is connected to the control section 12 to detect contact with an object, a pressure-sensitive sensor 14 which is connected to the control section 12 to detect a pressure upon contact with the object, a friction sensor 15 which is connected to the control section 12 to detect a frictional force upon contact with the object, or the like. Then, grasping information as to an object detected by each of the sensors 13, 14, 15, respectively, is fed back to the control section 12, and the four pneumatic drive sources 4, . . . , 4 are controlled independently of one another by the control section 12 to control the pneumatic pressure supplied to their respective pneumatic operation chambers so that the flexural operation of their respective joint portions are controlled. Thus, it becomes possible to achieve the grasping operation more effectively. Further, by covering at least part of the grasping surface of the or each bone member 1 with a flexible material having a large frictional resistance, it becomes possible to improve the grasping power.

As shown above, according to the foregoing embodiment, the grasping hand is light in weight and small in size by virtue of the use of the above-described laminated-type multi-joint portion drive mechanism, and moreover high in compliance by virtue of the use of the driving source with pneumatic pressure used as the pneumatic drive source 4 for expansion of an elastic member, so that the grasping hand can be maintained safe enough in event of contact and collisions with persons by virtue of the above characteristics. Further, since electrical connections are not needed except for the sensor portions, there is an advantage that only with waterproof treatment of the sensor portions, the grasping hand becomes usable even under working environments in which water is used.

Next, with reference to FIGS. 17 to 22, for example, concrete grasping operation of a grasping hand according to still another modification of the second embodiment shown in FIGS. 15 and 16 is explained.

The operation of the grasping hand proceeds as follows, where a grasping operation of an object with the individual bone members 1 used as grasping surfaces is carried out by flexural operation.

First, in a neutral state of the grasping hand shown in FIG. 17, there are generated signals for applying pneumatic pressure from the control section 12 to the first pneumatic operation chamber 16A, the second pneumatic operation chamber 16B, and the third pneumatic operation chamber 16C located at the individual joint portions of the planar-type joint-portion flexural deformation member 3 of each multi-joint portion drive mechanism. By these signals, the four pneumatic drive sources 4, . . . , 4 are controlled for drive independently of one another to perform the opening and closing of solenoid valves 17 provided halfway on their respective pneumatic pressure introduction tubes 5, so that pneumatic pressure is applied from the pneumatic drive sources 4 to the first pneumatic operation chamber 16A, the second pneumatic operation chamber 16B, and the third pneumatic operation chamber 16C through their respective pneumatic pressure introduction tubes 5 and laminated-type pneumatic tube formation members 2, synchronously or successively. Along with the application of pneumatic pressure, the first pneumatic operation chambers 16A, the second pneumatic operation chambers 16B, and the third pneumatic operation chambers 16C are expanded, respectively, so that the joint portions are flexed, respectively. As a result of this flexural operation, the grasping operation of an object 18 is performed with the individual bone members 1 serving as grasping surfaces.

FIG. 17 is a plan view showing a state of the grasping hand in a neutral state that pneumatic pressure is not applied to the multi-joint portion drive mechanisms (a state that the multi-joint portion drive mechanisms are straightly stretched). These laminated-type multi-joint portion drive mechanisms have a function that when pneumatic pressure is applied from their pneumatic drive sources 4 to their pneumatic operation chambers under the control by the control section 12, those multi-joint portion drive mechanisms are displaced toward a grasping direction, i.e. mutually approaching direction, and that when the drive of their respective pneumatic drive sources 4 is halted to stop pneumatic pressure application under the control by the control section 12, the multi-joint portion drive mechanisms are restored to their original positions by the elasticity of the elastic hinges 1A of the respective multi-joint portion drive mechanisms, thus the grasping hand maintaining a neutral state. In this neutral state, applying to the individual joint portions a pneumatic pressure corresponding to the grasping object under the control by the control section 12 allows the grasping operation to be fulfilled.

FIGS. 18A and 18B are plan views showing a model in a case where the object to be grasped is, for example, a cylindrical or columnar shaped grasping object 18 whose size (diameter or width) is nearly equal to the opening distance of each multi-joint portion drive mechanism in a neutral state of the grasping hand. As shown in FIG. 18A, first, the grasping hand is moved by an unshown carrier vehicle or the like on which the grasping hand is placed until the grasping object 18 comes close to a proximity to the fixing portion 11. Thereafter, under the control by the control section 12, pneumatic pressure is applied from the respective pneumatic drive sources 4 to the first pneumatic operation chambers 16A, which are the closer to the fixing portion 11, of the multi-joint portion drive mechanisms, respectively, as shown in FIG. 18B, so that the first joint portions are flexed inward, i.e., toward the grasping direction. At a time point when the respective grasping surfaces have come into contact with the grasping object 18 (e.g., a time point when contact sensors provided at the grasping surfaces of the individual multi-joint portion drive mechanisms have each inputted to the control section 12 signals representing contact with the grasping object 18), pneumatic pressure is applied from the pneumatic drive sources 4 to the second pneumatic operation chambers 16B, respectively, under the control by the control section 12, by which the respective second joint portions are flexed so that the grasping object 18 is embraced by the four multi-joint portion drive mechanisms, thus a grasping being achieved. For releasing the grasping, as described above, the drive of the respective pneumatic drive sources 4 is halted to stop the pneumatic pressure application under the control by the control section 12, so that the multi-joint portion drive mechanisms are restored to their original positions, not being flexed but being straightly stretched, by the elasticity of the elastic hinges 1A of the respective multi-joint portion drive mechanisms, thus the grasping hand coming into a neutral state, i.e., a grasping-released state.

FIGS. 19A and 19B are plan views showing a model in a case where the object to be grasped is, for example, a cylindrical or columnar shaped grasping object 19 whose diameter or width is smaller than the opening distance of each multi-joint portion drive mechanism in a neutral state of the grasping hand. As shown in FIG. 19A, first, the grasping hand is moved by an unshown carrier vehicle or the like with the grasping hand placed thereon until the grasping object 19 comes close to an end portion of each multi-joint portion drive mechanism. Thereafter, under the control by the control section 12, pneumatic pressure is applied from the respective pneumatic drive sources 4 to the first pneumatic operation chambers 16A, the second pneumatic operation chambers 16B, and the third pneumatic operation chambers 16C of the multi-joint portion drive mechanisms, successively in an order of increasing distance to the fixing portion 11, as shown in FIG. 19B, so that the joint portions are flexed inward, i.e., toward the grasping direction. At a time point when the respective grasping surfaces have come into contact with the grasping object 19 (e.g., a time point when contact sensors provided at the grasping surfaces of the respective multi-joint portion drive mechanisms have each inputted to the control section 12 signals representing contact with the grasping object 19), pneumatic pressure is further applied from the pneumatic drive sources 4 to the second pneumatic operation chambers 16B, respectively, under the control by the control section 12, by which the respective second joint portions are flexed so that the grasping object 19 is pinched by the four multi-joint portion drive mechanisms, thus a grasping being achieved. For releasing the grasping, as described above, the drive of the respective pneumatic drive sources 4 is halted to stop the pneumatic pressure application under the control by the control section 12, so that the multi-joint portion drive mechanisms are restored to their original positions, not being flexed but being straightly stretched, by the elasticity of the elastic hinges 1A of the respective multi-joint portion drive mechanisms, thus the grasping hand coming into a neutral state, i.e., a grasping-released state.

FIGS. 20A, 20B, and 21 are plan views showing a model in a case where the object to be grasped is, for example, a cylindrical or columnar shaped grasping object 20 whose diameter or width is larger than the opening distance of each multi-joint portion drive mechanism in a neutral state of the grasping hand. In this example, the pneumatic drive sources 4 connected to the respective laminated-type multi-joint portion drive mechanisms have a reverse drive (evacuative drive) controllability or forced evacuative function of pressure reducing pumps or the like in addition to the pneumatic pressure application function. By the respective pneumatic drive sources 4 being driven into evacuation under the control by the control section 12, in the neutral state of FIG. 20A, air is forcedly discharged from the first pneumatic operation chambers 16A, the second pneumatic operation chambers 16B, and the third pneumatic operation chambers 16C of each laminated-type multi-joint portion drive mechanism as shown in FIG. 20B, by which each laminated-type multi-joint portion drive mechanism is broadened in its opening distance even more than that of the neutral state in which pneumatic pressure is not applied, thus making it easier to put the grasping object 20 into the grasping hand. Thereafter, the grasping hand is moved by an unshown carrier vehicle or the like with the grasping hand placed thereon until the grasping object 20 comes close to an end portion of each multi-joint portion drive mechanism. Thereafter, under the control by the control section 12, pneumatic pressure is applied from the respective pneumatic drive sources 4 to the first pneumatic operation chambers 16A, the second pneumatic operation chambers 16B, and the third pneumatic operation chambers 16C of the multi-joint portion drive mechanisms, successively in an order of increasing distance to the fixing portion 11, as shown in FIG. 21, so that the joint portions are flexed inward, i.e., toward the grasping direction. At a time point when the respective grasping surfaces have come into contact with the grasping object 20 (e.g., a time point when contact sensors provided at the grasping surfaces of the individual multi-joint portion drive mechanisms have each inputted to the control section 12 signals representing contact with the grasping object 20), pneumatic pressure is further applied from the pneumatic drive sources 4 to the third pneumatic operation chambers 16C, respectively, under the control by the control section 12, by which the respective second joint portions are flexed so that the grasping object 20 is pinched by the four multi-joint portion drive mechanisms, thus a grasping being achieved. For releasing the grasping, as described above, the drive of the respective pneumatic drive sources 4 is halted to stop the pneumatic pressure application under the control by the control section 12, so that the multi-joint portion drive mechanisms are restored to their original positions, not being flexed but being straightly stretched, by the elasticity of the elastic hinges 1A of the respective multi-joint portion drive mechanisms, thus the grasping hand coming into a neutral state, i.e., a grasping-released state. Further, for more reliable releasing of the grasping, by forcedly discharging air from the first pneumatic operation chambers 16A, the second pneumatic operation chambers 16B, and the third pneumatic operation chambers 16C of each laminated-type multi-joint portion drive mechanism, the laminated-type multi-joint portion drive mechanism is broadened in its opening distance even more than that of the neutral state in which pneumatic pressure is not applied, thus making the grasping object 20 more easily disengaged from the grasping hand.

As shown above, the grasping hand having at least one pair of multi-joint portion drive mechanisms has a characteristic of making it possible to grasp various and diverse objects.

(Third Embodiment)

FIG. 22 is a perspective view of a robot which uses a laminated-type multi-joint portion drive mechanism according to a third embodiment of the present invention and in which the grasping hand of FIG. 12 according to the second embodiment is provided at the end of the robot arm of the laminated-type multi-joint portion drive mechanism of FIG. 1.

The robot arm 21 of FIG. 22 is constructed by using the laminated-type multi-joint portion drive mechanism shown in FIG. 1 according to the first embodiment, its drive principle being as described in the first embodiment. The robot arm 21 is connected to a robot arm prop 22 having a pneumatic drive source a rolling mechanism 23 via a rolling mechanism 23, and further a grasping hand 24 shown in FIG. 12 according to the second embodiment is connected to an end portion of the robot arm 21. By the drive of the robot arm 21, the grasping hand 24 is positioned to an arbitrary position within a movable range to grasp a grasping object. This robot arm 21, which uses the laminated-type multi-joint portion drive mechanism of the present invention, makes it possible to achieve a flexible positioning that ensures safety to persons who use the robot arm as described above.

Furthermore, in the case where the laminated-type multi-joint portion drive mechanism is applied to the robot arm 21, it is more desirable to set its laminated surfaces along the vertical direction as in the third embodiment of FIG. 22. With such a construction, since the bone members 1 are high in in-plane rigidity, it becomes possible to support heavyweight grasping objects with the bone members 1, thus enabling the robot arm to treat heavyweight grasping objects.

The third embodiment of FIG. 22 has been described above on a construction in which the robot arm 21 is connected to the robot arm prop 22 via the rolling mechanism 23. However, without being limited to this, the construction may be given in other ways, for example, one in which such a uniaxial or multiaxial rolling mechanism is provided at the root portion of the robot arm prop 22 or between the robot arm 21 and the grasping hand 24. In combinations with such a multiaxial rolling mechanism, it becomes possible to make the grasping hand more flexibly postured.

By properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by the embodiments can be produced.

As described hereinabove, according to the present invention, the laminated-type multi-joint portion drive mechanism includes a bone member having at least two elastically-deformable elastic deformation portions, a laminated-type pneumatic tube member having at least two-line tubes which are fixed so as to be laid on the bone member and which are connected to the pneumatic drive source, and a planar-type joint-portion deformation member which is fixed so as to be laid on the laminated-type pneumatic tube member and which has pneumatic operation chambers placed at joint portions confronting the elastic deformation portions of the bone member, respectively, and connected to the tubes, respectively, wherein with pneumatic pressure applied to the pneumatic operation chambers, the joint portion(s) corresponding to the pneumatic operation chamber(s) to which the pneumatic pressure is applied is deformable, and wherein with pneumatic pressure applied to the pneumatic operation chamber(s) corresponding to the joint portion(s) which need to be driven, the joint portions become deformable. With this constitution, there can be provided a laminated-type multi-joint portion drive mechanism which is capable of realizing a grasping hand having a grasping performance for the grasping of various and diverse objects, and which is safe and simple in structure, and moreover which can be realized with low cost.

The grasping hand in which this laminated-type multi-joint portion drive mechanism is arranged face to face can be realized with a simple structure and low cost as a grasping hand which has a grasping performance for the grasping of various and diverse objects, and which is safe, and which has multi-joint portions.

Also, the laminated-type multi-joint portion drive mechanism can be manufactured simply and with low cost by integrally molding the bone member having elastic hinges at at least the elastic deformation portions and stacking and bonding the laminated-type pneumatic tube member and the planar-type joint-portion flexural deformation member together on the bone member in the manufacture of the laminated-type multi-joint portion drive mechanism.

Further, when the bone member forming a part of the multi-joint portion drive mechanism has elastic hinges at its joint portions, the laminated-type multi-joint portion drive mechanism of the present invention is enabled to improve the grasping rigidity by constraining the degree of freedom of the joint portions to one degree of freedom, so that the above working effects can be achieved more effectively.

Furthermore, the robot arm using the laminated-type multi-joint portion drive mechanism of the present invention, when provided with the grasping hand at its distal end, is enabled to fulfill a safe positioning of the grasping hand against a grasping object located within its movable range.

Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

Claims

1. A laminated-type multi-joint portion drive mechanism comprising: a pneumatic drive source for pneumatic pressure; a bone member having at least two elastically-deformable elastic deformation portions; a laminated-type pneumatic tube member having at least two-line tubes which are fixed so as to be laid on the bone member and which are connected to the pneumatic drive source; and a planar-type joint-portion flexural deformation member which is fixed so as to be laid on the laminated-type pneumatic tube member and which has pneumatic operation chambers placed at joint portions confronting the elastic deformation portions of the bone member, respectively, and connected to the tubes, respectively, wherein with pneumatic pressure applied to the pneumatic operation chamber, the joint portion corresponding to the pneumatic operation chamber to which the pneumatic pressure is applied is deformable.

2. The laminated-type multi-joint portion drive mechanism as defined in claim 1, wherein the laminated-type pneumatic tube member is so formed that a plurality of molded organic films are stacked one on another to form the tubes.

3. The laminated-type multi-joint portion drive mechanism as defined in claim 1, wherein the planar-type joint-portion flexural deformation member comprises a constrained layer for imparting a directivity of expandability and contractibility to the planar-type joint-portion flexural deformation member along its longitudinal direction, wherein when the joint portions of the planar-type joint-portion flexural deformation member are expanded, a flexural operation is performed by guide of the bone member.

4. The laminated-type multi-joint portion drive mechanism as defined in claim 1, wherein the plurality of elastic deformation portions of the bone member are elastic hinge portions, respectively.

5. The laminated-type multi-joint portion drive mechanism as defined in claim 3, wherein the plurality of elastic deformation portions of the bone member are elastic hinge portions, respectively.

6. The laminated-type multi-joint portion drive mechanism as defined in claim 3, wherein the constrained layer of the planar-type joint-portion flexural deformation member is a flexible organic film material in which reticulate fiber is knitted.

7. The laminated-type multi-joint portion drive mechanism as defined in claim 4, wherein the planar-type joint-portion flexural deformation member comprises a constrained layer for imparting a directivity of expandability and contractibility to the planar-type joint-portion flexural deformation member along its longitudinal direction, wherein when the joint portions of the planar-type joint-portion flexural deformation member are expanded, a flexural operation is performed by guide of the bone member, and wherein the constrained layer of the planar-type joint-portion flexural deformation member is a flexible organic film material in which reticulate fiber is knitted.

8. The laminated-type multi-joint portion drive mechanism as defined in claim 5, wherein the planar-type joint-portion flexural deformation member comprises a constrained layer for imparting a directivity of expandability and contractibility to the planar-type joint-portion flexural deformation member along its longitudinal direction, wherein when the joint portions of the planar-type joint-portion flexural deformation member are expanded, a flexural operation is performed by guide of the bone member, and wherein the constrained layer of the planar-type joint-portion flexural deformation member is a flexible organic film material in which reticulate fiber is knitted.

9. A method for manufacturing the laminated-type multi-joint portion drive mechanism as defined in claim 1, the method comprising: integrally molding the bone member having elastic hinges at at least the elastic deformation portions; and stacking and bonding the laminated-type pneumatic tube member and the planar-type joint-portion flexural deformation member on the bone member.

10. A grasping hand having the laminated-type multi-joint portion drive mechanism as defined in claim 1 which is arranged face to face to be capable of grasping an object.

11. A grasping hand having the laminated-type multi-joint portion drive mechanism as defined in claim 3 which is arranged face to face to be capable of grasping an object.

12. A grasping hand having the laminated-type multi-joint portion drive mechanism as defined in claim 4 which is arranged face to face to be capable of grasping an object.

13. A grasping hand having the laminated-type multi-joint portion drive mechanism as defined in claim 5 which is arranged face to face to be capable of grasping an object.

14. A grasping hand having the laminated-type multi-joint portion drive mechanism as defined in claim 6 which is arranged face to face to be capable of grasping an object.

15. A robot arm using the laminated-type multi-joint portion drive mechanism as defined in claim 1.

16. A robot arm using the laminated-type multi-joint portion drive mechanism as defined in claim 3.

17. A robot arm using the laminated-type multi-joint portion drive mechanism as defined in claim 4.

18. A robot arm providing the grasping hand as defined in claim 10 at an end of the arm.

19. A robot arm providing the grasping hand as defined in claim 11 at an end of the arm.

20. A robot arm providing the grasping hand as defined in claim 12 at an end of the arm.

21. A robot comprising: a robot arm which comprises a laminated-type multi-joint portion drive mechanism as defined in claim 1; and a grasping hand having a laminated-type multi-joint portion drive mechanism as defined in claim 1 which is arranged face to face to be capable of grasping an object, provided at an end of the robot arm.