Patent Application
20210139294
The invention relates to a manipulator having a carriage movable along a beam, a scissor lift mechanism having one end on the carriage, and a grab on the other end of the scissor lift mechanism.
As manipulators, pallet robots are known that are used for moving objects. Objects are for example flat structures such as cardboard, wooden boards and the like. Other objects such as for example Euro pallets, boxes and the like can however also be transferred by a pallet robot of this type.
To move an object, the pallet robot has a grab vertically movable on an also movable beam. It is known, for movement of the grab, for a T-shaped beam to be for example mounted on a ceiling of a machine hall or else on a mounting stand, on which beam there is in turn a trolley. For this purpose, open designs are known, such that the known trolleys very quickly accumulate dirt, permit only straight-line travel, and are of cumbersome and voluminous construction.
The object of the invention is to improve a known manipulator with regard to its operation.
This object is achieved by the features of patent claim 1.
According to the invention, a manipulator is provided having a carriage movable along a beam, a scissor lift mechanism that has multiple scissor members and a first end on the carriage and a second end on a support plate movable relative to the carriage by the scissor lift mechanism, and a grab on the support plate, a drive for actuating the scissor lift mechanism on the carriage, wherein the beam has an H-shaped cross section formed by a center web and by upper and lower flanges that project from this center web. This beam is arranged and fastened for example on the ceiling of a factory hall using suitable means. Alternatively, it is conceivable for the beam to be erected on a work area by stands that are preferably arranged at the two ends of the beam. In this way, the manipulator can be easily and quickly relocated from one working location to another working location. The H-shaped cross section of the beam offers extremely high stability if not only the carriage is moved along this beam but if loads, that is to say objects, are picked up, moved, and set down again by the grab via the scissor lift mechanism. The center web together with the two upper and lower flanges projecting therefrom furthermore has the advantage that a structural space (intermediate region) protected on three sides is available in which functional elements of the manipulator can be arranged. Furthermore, the fourth side can also be closed by a side wall of the carriage, such that the functional elements that are in this structural space on the beam or of the carriage are protected against access and dirt accumulation. Such an H-section beam is very stable over its entire length, such that a large work area (movement travel of the carriage) can be realized without a support being required between the two ends of the beam. In particular if the beam is erected on the work area by stands at its two ends, there is no need for further supports, in particular center supports, in between. Furthermore, such an H-section beam has a very high moment of inertia relative to the drive carriage, such that the required stability and precision during movement is thus realized. Since inherent oscillations of the manipulator are considerably reduced or virtually prevented owing to this very high moment of inertia, no anchoring on the ground is required in the case of the manipulator being erected on the work area. Furthermore, such a beam offers the advantage that dynamic loads are minimized, and only low shear forces arise during operation of the manipulator.
In a refinement of the invention, the drive for the carriage, together with its at least one drive wheel, is arranged in a region between two flanges, and the center web that connects these, of the H-section beam. Thus, the drive, as at least one functional element of the manipulator, is relocated into the interior region of the H-section beam, such that the entire manipulator can be of compact construction. Ideally, the carriage, by way of its side parts, encloses the interior region formed by the center web with its two projecting flanges, such that the compact design is thus realized and this interior region is protected against access. This is advantageous in particular if drive motors, devices for generating compressed air and/or a vacuum, controllers, power rails, transmission devices for signals and the like are situated as functional elements in this interior region.
In a refinement of the invention, the at least one drive wheel of the drive for the carriage and at least one guide wheel that guides the carriage are supported on the center web of the H-section beam, wherein the at least one guide wheel is also between two flanges, and the center web that connects these, of the H-section beam. This two wheels are thus supported in each case on one side of the center web, preferably exactly in the central region of this web between the upper and the lower flange. This primarily provides optimum guidance during movement of the carriage along the beam. Secondly, the drive wheel bears optimally against the surface of the center web, such that slippage during movement of the carriage is prevented. Furthermore, the support of the two wheels on the center web has the advantage that the contact surface thereof is substantially protected against dirt accumulation, such that the drive and the guidance of the carriage can be performed optimally and are not impaired by dirt accumulations that often arise in the spaces in which such a manipulator is erected (for example factory halls with production and handling of objects).
In a refinement of the invention, provision is made for the at least one drive wheel to be fixed on the carriage, and the at least one guide wheel is supported, in a manner decoupled by a spring, on a base of the carriage. The drive wheel is connected to the drive motor, for example an electric motor, and rotates in a manner driven by this drive motor in order to move the carriage relative to the beam. The reverse arrangement is also conceivable, in which, specifically, the drive wheel together with its drive motor is on the beam and acts on the carriage. Additionally, the at least one guide wheel is arranged so as to be supported on the base of the carriage in a manner decoupled by the spring (or equivalent elements, for example hydraulic or pneumatic cylinders or the like). In this way, the at least one drive wheel and the at least one guide wheel assigned thereto lie in an optimally interacting manner against the H-section beam, in particular the center web thereof, and thus effect smooth, slip-free and effective drive of the carriage. Ideally, each drive wheel is associated with an oppositely situated guide wheel, with the center web situated in between. It is conceivable for more than one drive wheel (for example two drive wheels) and more than one guide wheel (for example two guide wheels) to be provided. It is however also conceivable for only one drive wheel on one side of the center web to be assigned at least two, or else more than two, guide wheels on the opposite side of the center web. Owing to the assignment of at least one preferably spring-mounted guide wheel to the at least one drive wheel, use may also be made of a beam that has a curved longitudinal profile. This means that, for the invention, it may also be significant for use to be made not only of a beam of straight form in terms of its longitudinal profile, it rather also being possible to use a beam that has a curved longitudinal profile (for example has a slight curvature without or with a change in direction along the profile).
In a refinement of the invention, in each case at least one supporting wheel is on both sides of the center web of the H-section beam, and each wheel is supported on the lower flange. With these supporting wheels (support wheels), the carriage is supported in a vertical direction on the beam, such that an optimum load transfer of the load acting on the grab to the beam that is stationary is thus realized. It is optimally the case that a total of four supporting wheels are provided, and in each case one supporting wheel is provided approximately at the respective end of the carriage to the right and to the left of the center web.
In a refinement of the invention, provision is made for that region of the H-section beam that is open to the side to be provided (in single-part or else multi-part form) with a cover. With this cover, that is for example a constituent part of the carriage, the intermediate region between the center web and the upper and lower flanges projecting therefrom is entirely or almost entirely covered, such that the ingress of dirt into this intermediate region is prevented. Furthermore, this intermediate region is not readily accessible, that is advantageous in particular if hazardous functional elements (such as for example moving drive elements such as electric motors or the like or else power rails) are in this intermediate region. In order that this intermediate region can be made accessible for the purposes of installation or maintenance or cleaning or the like, provision is made in a further embodiment of the invention for the cover to be designed to be pivotable by a hinge. While, on the one hand, provision may be made for this cover to be on the carriage for example by way of a detent connection or else a screw connection, it is advantageous if the cover is designed to be pivotable by a hinge. In this way, the cover can be pivoted away in order to allow access to the intermediate region, and also cannot be lost in the process. This makes maintenance easier.
In a refinement of the invention, provision is made for a power supply at least for the drive of the carriage, optionally also for a drive for actuating the scissor lift mechanism and/or the grab, to be arranged in the region between two flanges, and the center web that connects these, of the H-section beam. This power supply preferably comprise a power rail that, in a refinement of the invention, is on the center web. Energy is supplied from an external source to the manipulator via this power rail, which energy is drawn by current collectors and distributed by power distributors to the functional elements of the carriage when the carriage is moved along the beam. A trailing cable can thus be omitted. Furthermore, the advantage is also realized here that the power supply is inside the H-section beam, such that it is thus significantly better protected against external access and dirt accumulation than if the beam were a T-shaped beam. This protection against external access and dirt accumulation is considerably increased yet further by the cover, formed by the carriage.
In a refinement of the invention, provision is made for the scissor lift mechanism to be on the carriage substantially so as to form the central vertical axis of the manipulator. By this substantially symmetrical arrangement of the scissor lift mechanism relative to the longitudinal and transverse axes of the carriage, through the intersection point of that the vertical axis runs, a uniform distribution of the load through the scissor lift mechanism and of the grab, that are arranged on the bottom side of the carriage, and of the load that acts on the carriage when an object has been picked up, on the carriage is realized, such that, in this way, a substantially uniform movement of the carriage is realized when it travels from the position where the object has been picked up to the position where the object is to be set down again. By this substantially uniform movement, the wear of the elements involved (in particular of the drive wheels, of the guide wheels and of the supporting wheels) is also considerably reduced. Altogether, the result is a very smooth movement sequence during operation of the manipulator. This embodiment, together with the high moment of inertia of the beam relative to the carriage, thus has a highly advantageous effect, because the dynamic loads are minimized and the shear forces during operation of the handling forces are only very low.
A manipulator (also referred to as a pallet robot) according to the invention will be described below with reference to an embodiment. The manipulator shown not only represents an embodiment according to the invention but also further essential features of the manipulator that, individually or in combination with one another, contribute to effective operation of this device.
This manipulator 1 comprises multiple components with their individual elements that will be described in detail below.
One component is a beam with a carriage that is present in the upper part of the manipulator 1.
A further component is a grab for handling objects such as, for example, flat structures such as cardboard, wooden boards, Euro pallets and the like. This grab can be seen in the lower part of
A further component is a scissor lift mechanism that connects the upper part of the manipulator 1 to the grab.
These individual components of the manipulator 1 will be described in detail below.
As can be seen in
The longitudinal beam 3 is stationary. It is installed for example under the ceiling of a building, in particular of a factory hall. It is alternatively conceivable for this longitudinal beam to be mounted on stands at least two points, in particular exactly two points. Particularly advantageous is the arrangement of exactly two stands at the two ends of the longitudinal beam 3, because, in this way, the carriage 2 can travel along the entire intermediate region between these two points. The carriage 2 thus moves horizontally.
Below the carriage 2, for upward and downward (vertical) movement of the grabs arranged below this carriage, there is a scissor lift mechanism 7. The grab can be moved to different heights by this powered scissor lift mechanism 7. By the vertical movement of the grab and the horizontal movement of the carriage 2, objects can be picked up, moved to a different position, and set down again by the grab.
The scissor mechanism 7 is, in a manner known per se, composed of multiple scissor members 8. The ends of two scissor-lift-mechanism members 8 are secured by respective pivots 9 to the bottom side of the carriage 2. Respective pivots 10 mount the ends of two further scissor-lift-mechanism members 9 on a support plate 11 of the grab. The fastening points 9, 10 make it possible for the angle at which the respective scissor-lift-mechanism members 8 lie relative to the bottom side of the carriage 2 or the top side of the support plate 11, respectively, to be varied in order to thus be able to vary the height H between the grab and the carriage 2 in targeted fashion.
Arranged below the support plate 11 of the grab is at least one bearing point 12 that receives at least one guide rod 13. A grab element 14 is arranged at the end of the guide rod 13. In one specific embodiment, a total of four bearing points 12 are provided, and in each case two bearing points 12 are assigned to one guide rod 13. This means that two guide rods 13 are provided, and each of the two guide rods 13 are movable and guided in two bearing points 12. Thus, a grab element 14 is mounted at one end of each of the guide rods 13. The two oppositely situated grab elements 14 can, by a controllable drive motor 15 that acts on the guide rods 13, be varied in terms of their spacing A to one another in order to grip an object (by virtue of the spacing A being reduced) and release this object again after it has been set down (by virtue of the spacing A being increased again at least slightly).
The height H of the scissor lift mechanism 7 is varied by an adjusting element 16. The adjusting element 16 secured by a mounting block 17 to the grab. At the end opposite the mounting block 17, the adjusting element 16 is connected to a drive 18. The adjusting element 16 is for example a toothed belt that extends between the drive 18 and the mounting block 17. By actuation of the adjusting element 16 by the drive 18, the height H of the scissor lift mechanism 7 is varied, whereby the inclination angle of the individual scissor-lift-mechanism members 8 with respect to one another changes in a manner known per se.
An alternative embodiment with regard to the grab is shown in
Instead of movement of the grab elements 14 of the grab by an electrically operated drive motor 15, it is conceivable for the drive or movement of the grab elements 14 to be realized by compressed air. For this purpose, a device 21 for generating compressed air is provided in the carriage 2. In this case, too, the compressed air generated by the device 21 can be transmitted via compressed-air hoses to the grab elements 14. It is likewise conceivable for the compressed air to be transmitted from the device 21 to the grab elements 14 via the interior of the scissor-lift-mechanism members 8. In this case, too, the connecting points of the scissor-lift-mechanism members 8 to one another and the fastening points 9, 10 are of sealed design in order to prevent compressed air (or a vacuum) from being able to escape at these locations where movable parts are connected to one another. The two devices 20, 21 may be provided in each case exclusively, such that the grab is operated either only with a vacuum or only with compressed air. It is also conceivable for the grab elements 14 to be operated in a manner controlled by the drive motor 15, and for the suction cups 19 to additionally be provided, such that, in this case, the device 20 for generating a vacuum is also provided in addition to the drive motor 15. In this case, the device 21 for generating compressed air can be omitted. It is furthermore conceivable for the grab elements 14 to be operated by compressed air, such that, in this case, the device 21 for generating compressed air is also provided in addition to the suction cups 19 and the device 20 for generating a vacuum. Since the scissor lift mechanism 7 comprises two sets of scissor-lift-mechanism members 8, it is conceivable for one set or both sets to be designed and used for the transmission (and storage) of compressed air or for one set or both sets to be designed and used for the transmission (and storage) of a vacuum or for one set to be designed and used for the transmission (and storage) of compressed air and for the other set to be designed and used for the transmission (and storage) of a vacuum.
In order to be able to control the height H between the support plate 11 and the carriage 2 in targeted fashion and pick up an object from a first position, move this object and set this object down again at a second desired position, it is necessary to detect the value of the height H, that is to say the spacing between the carriage 2 and the support plate 11. This detection is performed by a guide rod 22 that coacts with a sensor 23. The sensor 23 is coupled to one of the scissor-lift-mechanism members 8 such that, during the extension or contraction of the scissor lift mechanism 7, the spacing of the sensor 23 from the guide rod 22 changes, and this change is detected by the sensor 23 and is a measure for the height H. The output value of the sensor 23 is transmitted in wireless or wired fashion to the controller 6 (and possibly to a further control and/or monitoring device outside the manipulator 1). The sensor 23 is coupled by suitable coupling means (not illustrated) at a coupling point K to the scissor-lift-mechanism member 8 assigned thereto. In this case, the guide rod 22 serves merely for the guided movement of the sensor 23.
With regard to the illustration in
Further detail views of the longitudinal beam 3 in interaction with the carriage 2 are illustrated in
It can be seen in
The at least one drive wheel 4 that has already been schematically illustrated in
Depending on the design of the at least one drive wheel 4 (possibly with the aid of the at least one guide wheel 30), it is sufficient for the carriage 2 to be supported, on its movement travel, on the longitudinal beam 3. For the optimum guidance and also the best possible pick-up of objects and movement of objects that have been picked up and are to be moved by the grab, the carriage 2 has at least one supporting wheel 33 that, for example via a shaft 34, is arranged and supported on a base of the carriage 2 (for example of the side part thereof). For picking up loads, the at least one supporting wheel 33 is supported on the lower flange 27. It is of particular significance that the carriage 2 has in each case one supporting wheel 33 in each case approximately in the end region of this carriage, that is to say has a total of four supporting wheels 33. Two of the supporting wheels 33 are thus supported on the lower flange 27 on one side of the center web 25, and the two further supporting wheels 33 are supported on the other side. As an alternative to the four supporting wheels 33 as described above, use may also be made of three supporting wheels (tripod principle).
Alternatively or in addition to the power supply illustrated in
The invention will be described briefly once again in other words below:
Pallet robots are known that are used for moving objects. Objects are for example flat structures such as cardboards, wooden boards and the like. Other objects such as for example Euro pallets, boxes and the like can however also be transferred by a pallet robot of this type.
To move an object, the pallet robot has a grab that is vertically movable on an also movable beam. It is known, for movement of the grab, for a T-shaped beam to be for example mounted on a ceiling of a machine hall or on a mounting stand, on which beam there is in turn a trolley. For this purpose, open designs are known, such that the known trolleys very quickly accumulate dirt, permit only straight-line travel, and are of cumbersome and voluminous construction.
The invention is based on the object of providing a pallet robot having a drive for a grab that is improved relative to the known prior art.
According to the invention, an H-section beam is provided in the case of that the drive, the power supply for the drive, the data transmission means for the control of the drive and possibly of the grab, and support means, are arranged and covered between the two flanges of the H-section beam. By this compact design, dirt accumulation and thus wear are avoided, and the weight is considerably reduced. It is thus possible, in particular in the case of the H-section beam being mounted on stands, to realize relatively long movement travels without the need for intermediate supports relative to the ground.
The motor is advantageously integrated in the region between the flanges of the H-section beam. The drive wheel that is driven by the motor, is decoupled from the supporting wheel, such that the drive wheel is arranged in the middle of the “H”, while counterpart wheels for support purposes are provided on the other side of the “H”. These counterpart wheels are mounted in spring-loaded fashion, such that movement along a curve is possible. By the arrangement of the drive wheel and counterpart wheels that are supported on the center web of the “H”, a centered accommodation of load is realized. The power rail for the power supply for the drive motor may be integrated within the two flanges of the H. The movable carriage that supports the drive motor, the drive wheel, the counterpart wheels and further functionally important elements may be closed off on one side or else on both sides by a cover in order to prevent dirt accumulation. Furthermore, one side of the movable carriage can be pivoted away such that not only easy installation but also an easy exchange and easy maintenance are possible.
The H-section beam is provided with a highly stable arrangement over its longitudinal extent, such that either no central support or only very few central supports are required. Furthermore, such a beam has very high moments of inertia relative to the carriage, such that this beam is not only very stable but ideally requires no anchoring points on the ground. Furthermore, the dynamic loads are minimized, and very low shear forces arise in operation during movement of the carriage and thus during movement of the grab.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 112 237.0 | Jun 2017 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/064311 | 5/30/2018 | WO | 00 |
