JP2012183619A - Joint device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint device of a robot, which can achieve a relative rotation angle that exceeds 360 degrees even with a mechanism for regulating the relative rotation angle between a first connection part and a second connection part.SOLUTION: The joint device for connecting the first connection part 1 and the second connection part 2 through a bearing part includes: a first stopper pin 6 provided in the first connection part; a second stopper pin 8 provided in the second connection part 2; and an intermediate ring 7 concentrically formed with the second connection part 2 freely to rotate. The intermediate ring 7 includes: a projecting part 7d capable of rotating by only a first rotation angle (θ1) relative to the first stopper pin 6; and a recessed part 7e capable of rotating by only a second rotation angle (θ2) relative to the second stopper pin 8. After the rotation more than the first or the second rotation angle is regulated by any one of the projecting part 7d and the recessed part 7e, the maximum of the relative rotation angle between the first connection part and the second connection part is allowed to be (θ1+θ2) till the rotation is regulated by the another of the projecting part 7d and the recessed part 7e.

Description

  The present invention relates to a joint device for a robot in which a first connecting portion and a second connecting portion are connected via a bearing portion so as to be rotatable relative to a common rotating shaft.

  Industrial robots are used for various purposes such as automating human work, assembling parts, and inspection (for example, Patent Document 1 below). In such a robot, it is indispensable to provide a joint device, and the first connection portion and the second connection portion are connected to each other via a bearing portion so as to be relatively rotatable.

  In such a case, it may be necessary to limit the angle of the relative rotation. For example, it is a case where wiring is passed through a connecting portion. If the relative rotation angle greatly exceeds 360 ° and is set to unlimited, the wiring is twisted, resulting in problems such as disconnection. Therefore, it is necessary to regulate the relative rotation angle. FIG. 6 conceptually shows a configuration for restricting such a rotation angle.

  The 2nd connection part 200 is connected with respect to the 1st connection part 100 so that relative rotation is possible. A stopper pin 101 is fixedly attached to the first connecting part 100. The second connecting portion 200 is integrally formed with a regulation protrusion 201. In the state of FIG. 6, the second connecting part 200 cannot rotate further clockwise, but can rotate counterclockwise. After rotating by an angle α in the counterclockwise direction, the stopper pin 101 comes into contact with the opposite side and cannot be rotated further counterclockwise.

JP 2011-5635 A

  In the case of the above configuration, the angle α at which the second connecting part 200 can relatively rotate is 360 ° or less. This is in principle not allowed to exceed 360 ° as long as the size of the stopper pin 101 is finite. However, in reality, there is a desire to realize a relative rotation angle exceeding 360 °. This is because the operating range of the robot is expanded and the degree of freedom is further increased.

  The present invention has been made in view of the above circumstances, and its problem is that the joint apparatus of the robot exceeds 360 ° while having a mechanism for regulating the relative rotation angle between the first connecting portion and the second connecting portion. To provide a joint device capable of realizing a relative rotation angle.

In order to solve the above-described problems, the joint device according to the present invention provides:
A joint device for a robot in which a first connecting portion and a second connecting portion are connected via a bearing portion so as to be rotatable relative to a rotating shaft,
A first stopper member provided on one of the first connecting part or the second connecting part;
A second stopper member provided on the other of the first connecting part or the second connecting part;
An intermediate member that is concentric with the rotating shaft and freely rotatable on the first connecting portion or the second connecting portion,
A first rotation restricting portion that allows the intermediate member to rotate by a first rotation angle (θ1) between a position in contact with the first stopper member from a clockwise direction and a position in contact with the counterclockwise direction;
A second rotation restricting portion that is rotatable by a second rotation angle (θ2) between a position that contacts the second stopper member from the clockwise direction and a position that contacts the second stopper member from the counterclockwise direction;
Even after the further rotation is restricted by one of the first rotation restricting portion and the second rotation restricting portion, the rotation is restricted by either one of the first rotation restricting portion and the second rotation restricting portion. Until then, the relative rotation angle between the first connecting portion and the second connecting portion is configured to be allowed up to (θ1 + θ2).

  The operation and effect of the joint device having such a configuration will be described. For convenience of explanation, it is assumed that a first stopper member is provided at the first connecting portion and a second stopper member is provided at the second connecting portion. In the present invention, the first connecting portion may be provided with a second stopper member, and the second connecting portion may be provided with a first stopper member. The present invention is characterized in that the intermediate member is provided. The intermediate member is provided with a first rotation restricting portion that comes into contact with the first stopper member, thereby enabling relative rotation of the first rotation angle (θ1). Moreover, the 2nd rotation control part contact | abutted with respect to a 2nd stopper member is provided, and, thereby, the relative rotation of a 2nd rotation angle ((theta) 2) is attained.

  For example, after the second connecting portion is rotated and further rotation is restricted by the second rotation restricting portion, until the rotation is restricted by the first rotation restricting portion, the first connecting portion and the second connecting portion. The maximum relative rotation angle of (θ1 + θ2) is possible. For example, as described above, neither θ1 nor θ2 can exceed 360 °. However, if configured as described above, a rotation angle exceeding 360 ° can be realized by (θ1 + θ2). As described above, it is possible to provide a joint device that can realize a relative rotation angle exceeding 360 ° with a simple configuration in which an intermediate member is provided.

  In the present invention, the intermediate member is formed in a ring shape, a protrusion as the first rotation restricting portion is formed on the outer diameter side, and an arc-shaped recess as the second rotation restricting portion is formed on the inner diameter side. It is preferable.

  As described above, by using the ring-shaped intermediate member, the configurations of the first and second rotation restricting portions can be efficiently arranged on the inner diameter side and the outer diameter side. Therefore, the intermediate member can be arranged without increasing the size of the joint device itself.

  In the present invention, it is preferable that the first stopper member and the second stopper member are each formed as a shaft-shaped member.

  By setting it as a shaft-shaped member, formation to a 1st connection part and a 2nd connection part can also be performed easily, and arrangement | positioning space can also be suppressed. In addition, as a shaft-shaped member, it can form with various shapes, such as a cylinder, a cylinder, and a prism, and is not limited to a specific shape.

  In this invention, it is preferable that the said internal diameter side of the said intermediate member is fitted by the cylindrical protrusion part provided in the 1st connection part or the 2nd connection part.

  With this configuration, the intermediate member can be rotatably attached. Further, a special member for fitting and attaching the intermediate member is not necessary.

Sectional drawing which shows the arm of the robot which has the joint apparatus of the robot which concerns on this invention Sectional view showing the configuration of the joint device External perspective view showing the configuration of the joint device Diagram explaining the action of the intermediate ring Diagram explaining the action of the intermediate ring Diagram explaining the action of the intermediate ring Diagram explaining the action of the intermediate ring The figure explaining the effect | action of the intermediate ring which concerns on another embodiment The figure explaining the effect | action of the intermediate ring which concerns on another embodiment The figure explaining the effect | action of the intermediate ring which concerns on another embodiment The figure explaining the effect | action of the intermediate ring which concerns on another embodiment Diagram explaining the problems of the prior art

  A preferred embodiment of a joint device for a robot according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an arm of a robot having a robot joint device according to the present invention. FIG. 2 is a cross-sectional view showing the configuration of the joint device. FIG. 3 is an external perspective view showing the configuration of the joint apparatus (view of the apparatus shown in FIGS. 1 and 2 as viewed from below).

<Configuration of joint device>
A first arm A1 and a second arm A2 constituting the robot are connected to each other by a joint device B so as to be rotatable. The joint device B includes a first connecting part 1 and a second connecting part 2. Further, a radial bearing 3 and upper and lower thrust bearings 4 and 5 are interposed between the first connecting portion 1 and the second connecting portion 2. The 1st connection part 1 and the 2nd connection part 2 are comprised so that relative rotation is possible around the perpendicular | vertical rotating shaft.

<First connecting part>
The 1st connection part 1 is comprised by the 1st main body 10 and the 2nd main body 11, and the 2nd main body 11 is formed in flat form. When the 1st main body 10 and the 2nd main body 11 are couple | bonded, the bearing accommodating recessed part 1a is formed in the inner surface side. The bottom surface 11 a of the second body 11 receives and positions the upper end portion of the radial bearing 3. The surface 11b of the second main body 11 receives and positions the thrust bearing 4.

  The upper surface 10 a that forms the bearing housing recess 1 a of the first main body 10 receives and positions the lower end portion of the radial bearing 3. The bottom surface 10 b of the first main body 10 receives and positions the thrust bearing 5.

  As shown in FIG. 3, the first main body 10 is provided with a large-diameter portion 10c (flange-shaped) projecting in the radial direction. A first stopper pin 6 that functions as a first stopper member is implanted on the surface of the large-diameter portion 10c by a method such as press fitting.

<Second connecting part>
The second connecting portion 2 is configured by combining the first main body 20, the second main body 21, and the third main body 22. The 1st main body 20 is cylindrical shape, The center part functions as a space for letting a wiring pass. The radial bearing 3 is fitted to the outer peripheral surface 20 a of the first main body 20. The radial bearing 3 is positioned by the step portion 20b.

  The second main body 21 is coupled to the upper end surface of the first main body 20 by a bolt 23. The back surface 21a of the second main body 21 receives and positions the thrust bearing 4. The second body 21 is configured by integrally forming a flat upper surface 21b, a cylindrical side surface 21c, and a flange-shaped large-diameter portion 21d. The large-diameter portion 21d has the same outer diameter as the large-diameter portion 10c of the first connecting portion 1, and faces each other close to each other.

  The third main body 22 has a flat plate shape and is coupled to the lower end surface of the first main body 20 by a bolt 24. The back surface (upper surface) 22 a of the third main body 22 receives and positions the thrust bearing 5. A tooth portion 22b is formed on the side surface of the third main body, and a belt described later is engaged therewith. A step portion 22d is formed on the bottom surface (lower surface) 22c of the third main body 22, and the intermediate ring 7 (corresponding to an intermediate member) is rotatably fitted. A through hole is also formed in the center of the third main body 22 for passing the wiring.

  A second stopper pin 8 that functions as a second stopper member is implanted on the bottom surface of the third main body 22 by press fitting or the like.

  In the intermediate ring 7, the inner diameter portion of the ring-shaped main body 7 a is fitted to the stepped portion 22 d of the third main body 22. A projecting portion 7 b that functions as a first rotation restricting portion is integrally formed on the outer peripheral surface of the intermediate ring 7. A first contact surface 7c and a second contact surface 7d that can directly contact the first stopper pin 6 are formed on the protruding portion 7b.

  An arcuate recess 7e that functions as a second rotation restricting portion is formed on the inner peripheral surface of the intermediate ring 7. A first contact surface 7f and a second contact surface 7g that can directly contact the second stopper pin 8 are formed in the arc-shaped recess 7e.

  As shown in FIG. 1, the interlocking gear 30 is coupled to the lower surface of the third main body 22 of the second connecting portion 2. The rotation axis of the interlocking gear 30 is set to be vertical. A drive gear 31 that meshes with the interlocking gear 30 is supported by a drive shaft 32. The rotation shaft of the drive gear 31 is set horizontally. The interlocking gear 30 is provided with a rotational position detecting mechanism (not shown), and the rotational position of the interlocking gear 30, that is, the rotational position of the second connecting portion 2 is detected. The drive shaft 32 is rotationally driven by a motor (not shown).

  Parts constituting the first arm A <b> 1 are accommodated in the cover member 40. The first main body 10 of the first connecting portion 1 is attached to the position of the bearing portion 40 a of the cover member 40. Parts constituting the second arm A <b> 2 are accommodated in the cover member 41. The second main body 21 of the second connecting portion 2 is coupled to the bearing portion 41 a of the cover member 41. Thereby, by driving the drive shaft 32, the second connecting portion 2 rotates and the second arm A2 is rotationally driven.

<Operation of intermediate ring (1)>
Next, the operation of the intermediate ring 7 which is a feature of the present invention will be described. 4A to 4D are views showing a state when the second connecting portion 2 is rotated, and is a view of the apparatus shown in FIGS. 1 and 2 as viewed from below. In the position of FIG. 4A, the first contact portion 7 c of the protruding portion 7 b is in contact with the first stopper pin 6 of the first connecting portion 1. Further, the first contact portion 7 f of the arcuate recess 7 e is in contact with the second stopper pin 8. Even if the second stopper pin 8 is rotated clockwise, it cannot be rotated any more.

  The 2nd connection part 2 is rotated counterclockwise from the state of FIG. 4A. Then, as shown in FIG. 4B, the second stopper pin 8 rotates counterclockwise, and the second stopper pin 8 comes into contact with the second contact portion 7g of the arcuate recess 7e. At this time, the rotation angle of the second stopper pin 8 is θ2. The positional relationship between the first stopper pin 6 and the first contact portion 7c is not changed.

  Further, when the second connecting portion 2 is rotated, as shown in FIG. 4C, the second stopper pin 8 rotates the intermediate ring 7 in the counterclockwise direction while pressing the second contact portion 7g of the arcuate recess 7e. . As shown in FIG. 4D, when the second contact portion 7d of the protruding portion 7b contacts the first stopper pin 6, it can no longer rotate counterclockwise. The angle at which the intermediate ring 7 rotates is θ1.

  Accordingly, the second connecting portion 2 can rotate with respect to the first connecting portion 1 by an angle of (θ1 + θ2). Neither θ1 nor θ2 can theoretically exceed 360 °, but (θ1 + θ2) can exceed 360 °. The operation when rotating the second connecting portion 2 in the clockwise direction follows FIGS. 4D to 4A, contrary to the above.

  As shown in FIG. 2, the center part of the 2nd connection part 2 is used as a space for letting wiring pass. Therefore, when rotating the 2nd connection part 2 with respect to the 1st connection part 1, if comprised so that it can rotate infinitely, wiring will be twisted and malfunctions, such as a disconnection, will arise. Therefore, the relative rotation angle is regulated by providing a stopper pin or the like.

  On the other hand, if the stopper pin is simply provided, the rotatable angle is 360 ° or less. However, in reality, there is a desire to realize a rotation angle exceeding 360 °. As described above, by providing the intermediate ring 7, a rotation angle exceeding 360 ° can be realized. Thereby, the operation range as a robot is expanded, and the degree of freedom is further increased.

<Operation of the intermediate ring (2)>
In the above embodiment, the configuration in which the first connecting portion 1 is fixed and the second connecting portion 2 rotates is described. On the contrary, the operation when the first connecting portion 1 is rotated and the second connecting portion 2 is fixed will be described with reference to FIGS. That is, the operation when the drive source is connected to the first connecting portion 1 will be described. FIG. 5 is also a view as seen from the lower part of the apparatus, similar to FIG.

  The state shown in FIG. 5A is the same as FIG. 4A. The 1st stopper pin 6 of the 1st connection part 1 rotates clockwise from this state. FIG. 5B is in the middle of rotation. FIG. 5C shows a state in which the first stopper pin 6 is in contact with the first contact portion 7b of the protruding portion 7d by further rotating. The angle at which the first stopper pin 6 is rotated is θ1.

  If the 1st connection part 1 is further rotated from this state, the 1st stopper pin 6 will further push the intermediate ring 7, and will rotate the intermediate ring 7 clockwise. As a result, the first contact portion 7f of the arcuate recess 7e moves away from the second stopper pin 8, and the second contact portion 7g contacts the second stopper pin 8 as shown in FIG. 5D. As a result, the first stopper pin 6 can no longer rotate clockwise. Also in this case, the first connecting part 1 can rotate with respect to the second connecting part 2 by an angle of (θ1 + θ2), and (θ1 + θ2) can exceed 360 °.

<Another embodiment>
The robot using the joint device according to the present invention is not limited to a specific application. In the present embodiment, the intermediate ring 7 is provided in the second connecting portion 2, but may be provided in the first connecting portion 1. In the present embodiment, θ1 is set at a considerably larger angle than θ2, but the angle distribution can be set as appropriate.

A1 1st arm A2 2nd arm 1 1st connection part 2 2nd connection part 3 Radial bearing 4 Thrust bearing 5 Thrust bearing 6 1st stopper pin 7 Intermediate ring 7b Protrusion part 7c 1st contact surface 7d 2nd contact surface 7e Arc-shaped recess 7f First contact surface 7g Second contact surface 8 Second stopper pin 10 First body 11 Second body 20 First body 21 Second body 22 Third body

Claims (4)

A joint device for a robot in which a first connecting portion and a second connecting portion are connected via a bearing portion so as to be rotatable relative to a rotating shaft,
A first stopper member provided on one of the first connecting part or the second connecting part;
A second stopper member provided on the other of the first connecting part or the second connecting part;
An intermediate member that is concentric with the rotating shaft and freely rotatable on the first connecting portion or the second connecting portion,
A first rotation restricting portion that allows the intermediate member to rotate by a first rotation angle (θ1) between a position in contact with the first stopper member from a clockwise direction and a position in contact with the counterclockwise direction;
A second rotation restricting portion that is rotatable by a second rotation angle (θ2) between a position that contacts the second stopper member from the clockwise direction and a position that contacts the second stopper member from the counterclockwise direction;
Even after the further rotation is restricted by one of the first rotation restricting portion and the second rotation restricting portion, the rotation is restricted by either one of the first rotation restricting portion and the second rotation restricting portion. The joint device is configured to allow a maximum relative rotation angle of the first connecting portion and the second connecting portion up to (θ1 + θ2). The intermediate member is formed in a ring shape, a protrusion as the first rotation restricting portion is formed on the outer diameter side, and an arc-shaped recess as the second rotation restricting portion is formed on the inner diameter side. The joint device according to claim 1. The joint device according to claim 1, wherein each of the first stopper member and the second stopper member is formed as a shaft-like member. The joint device according to claim 2, wherein the inner diameter side of the intermediate member is fitted into a cylindrical protrusion provided in the first connection portion or the second connection portion.

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