This application claims priority from Japanese Patent Application No. 2014-154076 filed with the Japan Patent Office on Jul. 29, 2014, the entire content of which is hereby incorporated by reference.
1. Technical Field
Embodiments of the disclosure relate to a robot.
2. Description of the Related Art
Typically, a robot includes a base portion that is installed on a floor surface or the like and an arm portion that has a base end pivotably and swingably coupled to the base portion. On the tip of the arm portion, an end effector for various works is mounted.
As such a robot, a robot that includes a balancer is known (for example, see JP-A-2012-148392). The balancer utilizes the restoring force of an extendable member including a spring, a fluid, or the like to reduce the load applied to, for example, a motor and/or a reducer when the arm portion is swung.
One side of the above-described balancer is rotatably coupled to the base portion. The other side of the balancer is rotatably coupled to the arm portion.
A robot according to one aspect of embodiments includes: a base portion to be installed on an installation surface; an arm portion having a base end coupled to the base portion, the base end being rotatable around a rotation shaft disposed approximately parallel to the installation surface; a balancer having one side rotatably coupled to the base portion and another side rotatably coupled to the arm portion; and a one-side coupling part positioned on a tip side of the arm portion with respect to the rotation shaft in the base portion, the one-side coupling part coupling the one side of the balancer.
In the following detailed description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
Embodiments of the robot disclosed in this application will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the technique of this disclosure.
A description will be given of the configuration of a robot 10 according to a first embodiment with reference to
The following describes a so-called perpendicular articulated robot as illustrated in
For convenience of explanation, the positional relationship, the operating directions, and the like of the respective portions in the robot 10 will be described below with reference to the posture of the robot 10 illustrated in
As illustrated in the drawings, the robot 10 includes a base portion 11 and an arm portion 12. The base portion 11 is installed on a floor surface 100 (
The base portion 11 is, for example, formed from cast metal or the like. The base portion 11 includes a base 111 that is installed on the floor surface 100, and a pivot base 112 that is rotatably disposed on the base 111. This pivot base 112 is rotatably coupled to the base 111 via a pivot shaft 300 disposed approximately perpendicular to the floor surface 100 (see an arrow 310 in
The arm portion 12 includes a lower arm 121 that is one example of a first arm, and an upper arm 122 that is one example of a second arm. The lower arm 121 is turnably coupled to the pivot base 112 via the rotation shaft 200. Here, the lower arm 121 swings back and forth around the rotation shaft 200 by the power from a turning motor 19b illustrated in
The base end portion of the upper arm 122 is coupled to the tip portion of the lower arm 121 to be rotatable around a turning shaft 400 approximately parallel to the rotation shaft 200 (see an arrow 410 in
As illustrated in
As illustrated in
The lower arm 121 includes a left-side arm constituting plate 121L and a right-side arm constituting plate 121R. The left-side arm constituting plate 121L and the right-side arm constituting plate 121R are both coupled to the rotation shaft 200, and face each other. That is, the lower arm 121 includes a left-and-right pair of arm constituting plates 121L and 121R.
The robot 10 according to this embodiment includes a balancer 16 for gravity compensation. The balancer 16 has a cylinder portion 161 and a rod portion 162. In the cylinder portion 161, fluid such as nitrogen gas is enclosed. The rod portion 162 advances and retreats by the pressure of the fluid inside the cylinder portion 161. Incidentally, the fluid in the cylinder portion 161 is one example of the extendable member. As the fluid in the cylinder portion 161, another gas or liquid such as oil can be used instead of nitrogen gas or the like.
The balancer 16 according to this embodiment is a so-called PULL-type balancer. The balancer 16 is configured to reduce the drive load on the arm portion 12 while the rod portion 162 is retreating. That is, in the balancer, 16, when the rod portion 162 has advanced, the rod portion 162 is biased in the contracting direction (retreating direction) by the fluid inside the cylinder portion 161. Accordingly, the total length of the balancer 16 in the initial state becomes shorter than that of a PUSH-type balancer configured to reduce the drive load on the arm portion 12 while a rod is advancing. This contributes to downsizing of the entire robot 10.
The balancer 16 is coupled to the base portion 11 by a first coupling part 161a that is disposed at the base end of the cylinder portion 161. Additionally, the balancer 16 is coupled to the arm portion 12 by a second coupling part 162a that is disposed at the tip of the rod portion 162. The first coupling part 161a and the second coupling part 162a are both formed in a ring shape.
More specifically, as illustrated in the drawings, the pivot base 112 of the base portion 11 includes a balancer mounting portion 113 that extends in the upper direction (the Z direction). The upper end of the balancer mounting portion 113 is formed to intervene between the left-side arm constituting plate 121L and the right-side arm constituting plate 121R in the lower arm 121. Here, the Z direction is the upper direction. More specifically, the Z direction is the normal direction of the installation surface (the floor surface 100).
At the upper end of the balancer mounting portion 113, a one-side coupling part 113a is disposed. The one-side coupling part 113a couples the first coupling part 161a that is disposed at the base end forming one side of the balancer 16. That is, in the lower arm 121, a balancer housing space 1210 is formed between the left-side arm constituting plate 121L and the right-side arm constituting plate 121R. The balancer mounting portion 113 is positioned in the balancer housing space 1210.
On the other hand, an other-side coupling part 121b is disposed in midway of the lower arm 121 (
As just described, the base portion 11 of the robot 10 according to this embodiment includes the one-side coupling part 113a. Accordingly, this one-side coupling part 113a is positioned on the tip side of the arm portion 12 with respect to the rotation shaft 200 at which the lower arm 121 of the arm portion 12 is rotatably supported. This one-side coupling part 113a couples the first coupling part 161a that is disposed at the base end side forming the one side of the balancer 16. In other words, the one-side coupling part 113a is formed at the position where the distance (installation length) to the one-side coupling part 113a from the installation surface in the normal direction (the Z direction) of the installation surface becomes longer than the installation length of the rotation shaft. That is, the base portion 11 includes the one-side coupling part 113a coupling the one side of the balancer 16 at the position where the one-side coupling part 113a has an installation length longer than that of the rotation shaft 200. On the other hand, the lower arm 121 of the robot 10 according to this embodiment has the other-side coupling part 121b. The other-side coupling part 121b couples the second coupling part 162a that is disposed on the tip side of the rod portion 162 forming the other side of the balancer 16.
The one-side coupling part 113a of the pivot base 112 is provided with a first shaft body 113b that extends approximately parallel to the rotation shaft 200. The first shaft body 113b pivotally supports the ring-shaped first coupling part 161a included in the balancer 16. On the other hand, the other-side coupling part 121b is similarly provided with a second shaft body 121c that extends approximately parallel to the rotation shaft 200. The second shaft body 121c pivotally supports the ring-shaped second coupling part 162a.
As just described, the entire balancer 16 according to this embodiment is arranged in the balancer housing space 1210 that is formed between the pair of arm constituting plates 121L and 121R. That is, as illustrated in
Accordingly, the balancer 16 according to this embodiment allows reducing the width of the robot 10, for example, in front view. This allows contributing to downsizing of the robot 10.
Incidentally, as illustrated in
Accordingly, in side view, the balancer 16 is arranged on the pivot shaft 300 side of the pivot base 112 with respect to the robot center line 800 and between the rotation shaft 200 and the turning shaft 400 in the lower arm 121.
In such a manner, the balancer 16 is coupled to the base portion 11 and the arm portion 12 to stride between these portions. Additionally, at least a part of the balancer 16 is arranged between the pair of arm constituting plates 121L and 121R. The one-side coupling part 113a disposed at the base portion 11 is formed to extend between the pair of arm constituting plates 121L and 121R.
The base end side of the balancer 16 is rotatably coupled to the base portion 11. Additionally, the tip side of the balancer 16 is rotatably coupled to the arm portion 12. In the balancer 16 according to this embodiment as the PULL-type balancer, as illustrated in
The rod portion 162 of the balancer 16 is preferred to be, for example, covered with an accordion cover member that expands and contracts to follow the advance and retreat of the rod. The cover member is effective to suppress the burning of the rod portion 162 due to sputtering or the like, for example, when the robot 10 is used for welding.
The robot 10 includes a rigging cable routed along the lower arm 121 (not illustrated). Here, the rigging cable includes a power supplying cable to the end effector and the respective motors, a hose, and the like.
In this embodiment, the balancer 16 is arranged between the left-side arm constituting plate 121L and the right-side atm constituting plate 121R. Accordingly, the rigging cable can be wired at any of the right and left sides of the lower arm 121 without interference with the balancer 16.
The base portion 11 of the robot 10 according to this embodiment includes the turning portion 17. The turning portion 17 has the rotation shaft 200 where the lower arm 121 of the atm portion 12 is supported at its both ends.
As illustrated in
Incidentally, as described above, the balancer 16 is arranged between the pair of arm constituting plates 121L and 121R. The axis line of the balancer 16 is arranged to approximately overlap with the robot center line 800 of the robot 10 in front view (see
The following describes the operation of the balancer 16 with reference to
The robot 10 in the state where the lower arm 121 stands approximately perpendicularly is illustrated in the upper part of
As illustrated in
Accordingly, when the lower arm 121 is tilted forward from the state illustrated in the upper part of
Thus, when the arm portion 12 is tilted, the balancer 16 causes the force supporting the arm portion 12 due to the restoring force caused by pulling of the rod portion 162 to act on the arm portion 12. Thus, it is possible to tilt the arm portion 12 including the upper arm 122, which extends further forward from the tip of the lower arm 121 having a predetermined length, in a wider range. On the other hand, the rod portion 162 of the balancer 16, which advances due to pulling, is biased in the retreating direction. This allows reducing the drive load when the tilted arm portion 12 is driven to be in a standing state.
The balancer 16 is arranged between the pair of arm constituting plates 121L and 121R. Additionally, the balancer 16 is arranged on the pivot shaft 300 side of the pivot base 112 with respect to the robot center line 800 in side view. Accordingly, even in the case where, for example, some peripheral members are present at the lower part of the robot 10 when the arm portion 12 is tilted forward (in the X direction), these members and the arm portion 12 are less likely to interfere with one another.
Additionally, the balancer 16 is arranged between the pair of arm constituting plates 121L and 121R and between the rotation shaft 200 and the turning shaft 400. Accordingly, the balancer 16 can contribute to downsizing of the robot 10.
A description will be given of the case where the lower arm 121 is tilted not obliquely forward but obliquely backward as the movement of the arm portion 12 of the robot 10.
As illustrated in
Accordingly, when the lower arm 121 is tilted backward from the state illustrated in the upper part of
Thus, when the arm portion 12 is tilted, the balancer 16 causes the force supporting the arm portion 12 due to the restoring force caused by pulling of the rod portion 162 to act on the arm portion 12. Thus, it is possible to tilt the arm portion 12 in a wide range. On the other hand, the rod portion 162 of the balancer 16, which advances due to pulling, is biased in the retreating direction. This allows reducing the drive load when the tilted arm portion 12 is driven to be in a standing state.
Even in this case, the balancer 16 is arranged between the pair of arm constituting plates 121L and 121R and between the rotation shaft 200 and the turning shaft 400. Accordingly, the balancer 16 can contribute to downsizing of the robot 10.
As described above, the robot 10 according to this embodiment can quickly change the posture of the arm portion 12 in a wide range without difficulty. This allows improving the efficiency for work using the robot 10.
Incidentally, the arrangement of the balancer 16 is not limited to the examples illustrated in
As described above, the robot 10 according to the first embodiment includes the base portion 11, the atm portion 12, and the balancer 16. The base portion 11 is installed on the installation surface such as the floor surface 100. The base end of the arm portion 12 is coupled to the base portion 11 to be rotatable around the rotation shaft 200 disposed approximately parallel to the installation surface. The one side of the balancer 16 is rotatably coupled to the base portion 11. The other side of the balancer 16 is rotatably coupled to the arm portion 12. The arm portion 12 (the lower arm 121) includes the pair of arm constituting plates 121L and 121R. The pair of the arm constituting plates 121L and 121R are both coupled to the rotation shaft 200 and face each other. At least a part of the balancer 16 is arranged between the pair of arm constituting plates 121L and 121R.
Thus, the robot 10, which is streamlined and downsized and in which the arm portion 12 and the peripheral members are less likely to interfere with each other, can be provided according to this embodiment.
Incidentally, the lower arm 121 only needs to be supported at its both ends and include the balancer housing space 1210. Accordingly, the shapes of the arm constituting plates 121L and 121R included in the lower atm 121 and the like may be changed as necessary. In this embodiment, the front and back surfaces of the lower arm 121 are opened. Instead, for example, the front surface of the lower arm 121 (the surface on the wrist portion 13 side of the upper arm 122) may be closed. In this case, the structure (shape) of the lower arm 121 has an approximately U shape in lateral cross-sectional view. The closed surface of the lower arm 121 is preferred to be the surface on the side far from the balancer 16.
Additionally, in this embodiment, the one-side coupling part 113a coupled to the one side of the balancer 16 is formed integrally with the pivot base 112. Furthermore, the one-side coupling part 113a is disposed at the balancer mounting portion 113 that intervenes between the left-side arm constituting plate 121L and the right-side arm constituting plate 121R. However, the one-side coupling part 113a only needs to be disposed at the base portion 11 side and positioned on the tip side of the arm portion 12 with respect to the rotation shaft 200. The other configuration of the one-side coupling part 113a may be changed as necessary.
As illustrated in
In this embodiment, the balancer 16 is arranged to overlap with the robot center line 800 of the robot 10 in front view. However, the position of the balancer 16 is not limited thereto. The balancer 16 is preferred to be arranged along the arm portion 12 so as to be close to the robot center line 800 of the robot 10.
The following describes the configuration of a robot 10A according to a second embodiment with reference to
The robot 10A according to this embodiment is a so-called perpendicular articulated robot, similarly to the embodiment described above. The robot 10A is, for example, an industrial robot that performs painting work, welding work, workpiece handling work to hold a workpiece, or the like. The positional relationship, the operating directions, and the like of the respective portions in the robot 10A will be described with reference to the posture of the robot 10A illustrated in
The robot 10A according to this embodiment and the robot 10 according to the first embodiment described above are different in the configuration of the pivot base 112 of the base portion 11, the configuration of the lower arm 121 of the arm portion 12, and the mounting position of the balancer 16. Hereinafter, the same reference numerals to those in the first embodiment are assigned to elements of the robot 10A with substantially the same functions to those of the robot 10. Furthermore, the following mainly describes the configurations different from the first embodiment. The descriptions of common configurations are omitted as necessary.
As illustrated in the drawings, the lower arm 121 of the robot 10A has a single arm coupled to the rotation shaft 200. Specifically, the lower arm 121 includes a single arm cantilevered by the turning portion 17 that has the reducer 18 and the turning motor 19b. As illustrated in
On the other hand, the upper arm 122 is swingably coupled to the tip portion of the left side surface 121d via the turning portion 170 that has a driving motor 19e and the like.
As illustrated in
As illustrated in
The upper-side portion of the turning portion 17 in the pivot base 112 is extended further upward, and the plate-shaped one-side coupling part 113a is disposed at this extended portion. That is, the base portion 11 includes the one-side coupling part 113a on the tip side of the arm portion 12 with respect to the rotation shaft 200. The robot 10A according to this embodiment is installed on the floor surface 100. Accordingly, the one-side coupling part 113a coupling the first coupling part 161a of the balancer 16 is disposed higher than that of the rotation shaft 200.
As just described, the one-side coupling part 113a is disposed in the lower part of the left side surface 121d of the lower arm 121 and at the position close to the turning portion 17. On the other hand, in the upper part of the left side surface 121d of the lower arm 121 and at the position close to the turning portion 170 that causes the upper arm 122 to swing, the other-side coupling part 121b coupling the second coupling part 162a of the balancer 16 is disposed.
This configuration allows compactly housing the balancer 16 in the vicinity of the center of the left side surface 121d of the lower arm 121, while avoiding interference of the balancer 16 with the turning portion 17 and protrusion of the balancer 16 from the whole outer edge of the robot 10A in front view.
On the other hand, in the robot 10A according to this embodiment, a rigging cable 21 is routed on a right side surface 121e on the side opposite to the left side surface 121d of the lower arm 121. The rigging cable 21 includes a power supplying cable to the end effector and the respective motors in the arm portion 12, a hose, and the like. That is, the rigging cable 21 is used for driving the arm portion. Usually, there are no large parts and the like on the right side surface 121e. Accordingly, as illustrated in
In such a manner, using both the side surfaces 121d and 121e of the lower arm 121, the balancer 16 and the rigging cable 21 are arranged independently from each other. Specifically, the balancer 16 and the rigging cable 21 are arranged on the respective different side surfaces 121d and e in the lower arm 121. Accordingly, as illustrated in
As a result, the one-side coupling part 113a is arranged close to the reducer 18. Accordingly, in the balancer 16 according to this embodiment, as illustrated in
This configuration allows reducing the offset amount between the reducer 18 arranged close to the left side surface 121d of the lower arm 121 and the axis line 160 of the balancer 16. Accordingly, similarly to the first embodiment, the moment load applied to the reducer 18 can be reduced by the compression load of the balancer 16 in the second embodiment. Thus, it is possible to suppress the adverse effect on the reducer 18 due to the moment load as much as possible.
A description will be given of the operation of the balancer 16 included in the robot 10A according to this embodiment.
The force supporting the arm portion 12 due to the restoring force caused by pulling of the rod portion 162 acts on the arm portion 12. Accordingly, it is possible to tilt the arm portion 12 in a wide range. On the other hand, the rod portion 162 of the balancer 16, which advances due to pulling, is biased in the retreating direction. This allows reducing the drive load when the tilted atm portion 12 is driven to be in a standing state.
As described above, the robot 10A according to this embodiment includes: the base portion 11; the arm portion 12 that has the base end rotatably coupled to the base portion 11 via the rotation shaft 200 disposed approximately horizontally; and the balancer 16 that has one side rotatably coupled to the base portion 11 and the other side rotatably coupled to the arm portion 12. The robot 10A includes the one-side coupling part 113a that is positioned on the tip side of the arm portion 12 with respect to the rotation shaft 200 in the base portion 11 and couples the one side of the balancer 16.
Thus, the arrangement of the balancer 16 that contributes to downsizing of the robot 10A can be provided according to this embodiment. Additionally, the robot 10A where the arm portion 12 and the peripheral members such as the balancer 16 are less likely to interfere with each other can be provided.
Incidentally, in this embodiment, the one-side coupling part 113a coupling the one side of the balancer 16 is disposed at the upper-side portion of the turning portion 17 in the pivot base 112. However, the one-side coupling part 113a only needs to be disposed on the base portion 11 side and positioned on the tip side of the arm portion 12 with respect to the rotation shaft 200. The other configuration of the one-side coupling part 113a may be changed as necessary.
Incidentally, in this embodiment, the balancer 16 is arranged on the pivot shaft 300 side of the pivot base 112 with respect to the robot center line 800 in side view. However, the position of the balancer 16 is not limited thereto. The balancer 16 may be arranged at the wrist portion 13 side of the upper arm 122 with respect to the robot center line 800 (see
According to the embodiments described above, a robot that includes the following respective means is provided. Specifically, the robot includes: means for installing; means for working that is rotatably cantilevered by the means for installing and performs a predetermined work; and means for compensating gravity that is disposed to stride between the means for installing and the means for working. The means for installing includes means for coupling one side on the tip side of the means for working with respect to means for supporting. The means for coupling one side couples one side of the means for compensating gravity. The means for supporting rotatably supports the means for working.
Additionally, a robot that includes the following respective means is also provided. Specifically, the robot includes: means for installing; means for working that is rotatably supported at its both ends by the means for installing via means for supporting and performs a predetermined work; and means for compensating gravity that is disposed to stride between the means for installing and the means for working. The means for working includes means for housing that houses at least a part of the means for compensating gravity.
Here, the above-described means for installing corresponds to the base portion 11. The above-described means for working corresponds to the arm portion 12 coupled to the wrist portion 13 having the flange portion 14. The means for compensating gravity corresponds to the balancer 16. The means for supporting corresponds to the rotation shaft 200. Furthermore, the means for coupling one side corresponds to the balancer mounting portion 113. The means for housing corresponds to the balancer housing space 1210.
As the respective motors 19a to 19d used in the respective embodiments described above, servo motors can be preferably used.
In the above-described embodiments, the balancer 16 is of a cylinder type, which has the cylinder portion 161 that encloses the fluid and the rod portion 162 that advances and retreats by the pressure of the fluid. Instead, the balancer 16 may be of a spring type, which has a tension spring or the like.
In the above-described embodiments, a multi-axis robot with six axes is described as an example. However, the number of axes of the robot according to the embodiments of this disclosure is not limited to six. For example, the robot according to the embodiments of this disclosure may be a 7-axis robot.
In the above-described embodiments, a single arm robot is described as an example. However, the number of arms of the robot according to the embodiments of this disclosure is not limited to one. For example, the above-described embodiments may be applied to at least any arm of a multi-arm robot that is at least a dual-arm robot.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
The robot according to the embodiments of this disclosure may be the following first to eighth robots.
A first robot includes: a base portion to be installed on an installation surface; an arm portion where a base end is coupled to the base portion to be rotatable around a rotation shaft disposed approximately parallel to the installation surface; and a balancer where one side and another side are respectively rotatably coupled to the base portion and the arm portion. The base portion includes a one-side coupling part coupling the one side of the balancer at a position on a tip side of the arm portion with respect to the rotation shaft.
In a second robot according to the first robot, the balancer includes: a cylinder portion enclosing fluid; and a rod portion configured to advance and retreat by a pressure of the fluid. The balancer reduces a drive load on the arm portion when the rod portion retreats.
A third robot according to the first or second robot includes a turning portion having the rotation shaft. The arm portion is swingably mounted on the base portion via the turning portion. The balancer is arranged along the arm portion such that an axis line of the balancer and a center line becomes close to each other. The center line passes through a center of an axial direction of the turning portion.
In a fourth robot according to the third robot, the turning portion includes a reducer coupled to the rotation shaft. The one-side coupling part is arranged close to the reducer.
In a fifth robot according to any one of the first to fourth robots, the base portion includes: a base to be installed on the installation surface; and a pivot base that has the one-side coupling part and is rotatably disposed on the base via a pivot shaft disposed approximately perpendicular to the installation surface. The arm portion includes a first arm and a second arm coupled to a tip of the first arm. The first arm has an other-side coupling part coupling the other side of the balancer. The first arm is turnably coupled to the pivot base via the rotation shaft.
In a sixth robot according to the fifth robot, the first arm includes a pair of arm constituting plates each coupled to the rotation shaft. The arm constituting plates face each other. At least a part of the balancer is arranged between the pair of arm constituting plates.
A seventh robot includes: a base portion to be installed on an installation surface; an arm portion where a base end is coupled to the base portion to be rotatable around a rotation shaft disposed approximately parallel to the installation surface; and a balancer where one side and another side are respectively rotatably coupled to the base portion and the arm portion. The base portion includes a one-side coupling part coupling the one side of the balancer at a position where a distance from the installation surface in a normal direction of the installation surface is larger than a distance to the rotation shaft from the installation surface.
An eighth robot includes: a base portion; an arm portion where a base end is coupled to the base portion to be rotatable via a rotation shaft disposed approximately horizontally; and a balancer where one side and another side are respectively rotatably coupled to the base portion and the arm portion. The base portion includes a one-side coupling part coupling the one side of the balancer at a position on a tip side of the arm portion with respect to the rotation shaft.
The foregoing detailed description has been presented for the purposes of illustration and description. Many modifications and variations are possible in light of the above teaching. It is not intended to be exhaustive or to limit the subject matter described herein to the precise form disclosed. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims appended hereto.
Number | Date | Country | Kind |
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2014-154076 | Jul 2014 | JP | national |