JP5107005B2 - Cable routing structure at the joint of the robot - Google Patents

Description

  The present invention relates to a cable wiring structure, and more particularly to a cable wiring structure in a joint portion of a robot suitable for use in a robot hand.

In a robot hand or the like, a cable for driving the robot hand is wired. As such cable wiring, a cable wiring structure in a welding robot disclosed in Patent Document 1 is conventionally known. In this cable wiring structure, the power supply cable and the gas hose are wound around the outer periphery of the power supply member with a winding radius and the number of turns determined in advance by the material and shape of the power supply cable to form a slack. In this cable wiring structure, the cable is loosened to reduce the load caused by the wiring when the robot is driven.
JP 2006-150378 A

  By the way, it is required to perform such cable wiring even in a small joint such as a robot hand, and the robot hand is also required to reduce a load caused by wiring. Here, by using the cable wiring structure disclosed in Patent Document 1 for the robot hand, it is possible to reduce the cable load when the robot hand is driven. However, since the robot hand is small, it is difficult to secure a space for slackening the cable.

  Since the cable wiring structure disclosed in Patent Document 1 is applied to a welding robot, a sufficient space for slackening can be secured, but the robot hand cannot secure the space. . Therefore, there is a problem that the cable wiring structure disclosed in Patent Document 1 cannot be applied to a small joint portion such as a joint of a robot hand.

  Therefore, an object of the present invention is to provide a cable wiring structure in a joint portion of a robot that can reduce a load when a small joint portion such as a joint of a robot hand is driven.

In the cable wiring structure in the joint portion of the robot according to the present invention that solves the above-described problem, the rod member is attached to the base member via the joint member, and the rod member is around one axis of the joint member with respect to the base member. It is possible to bend and is a cable wiring in a joint part of a robot wired between a rod member and a base member, wherein the cable mounting position in the rod member is a first mounting position, and the cable in the base member is The mounting position is defined as the second mounting position, and the first mounting position is set to a position in the vicinity of the joint member in the rod member, and the distal end portion of the rod member with respect to the base end portion mounted to the joint member is the second mounting position. The state that is relatively close to the first state is the first state, and the tip of the rod member is a position that is relatively far from the second mounting position. When the state is set to the second state, the first attachment position is set closer to the second attachment position when the rod member is in the first state than when the rod member is in the second state. When in the first state, the cable is loosely wired with two or more bending points, and when the rod member is in the second state, the cable is wired with two or more bending points eliminated. It is characterized by.

  In the cable wiring structure according to the present invention, when the rod member is driven around one axis of the joint member and the rod member is moved from the first state to the second state, the cable extends from the slack state. It becomes. At this time, since the cable is taken out from the first attachment position and the second attachment position in the above-described manner, the cable is wired in a direction in which a force is applied in the driving direction of the joint member. For this reason, the force which resists the direction which drives a rod member can be provided to a cable. On the other hand, since the cable is loosely wired with two or more bent portions, when the rod member moves from the second state to the first state, a load is applied in the direction in which the rod member is driven with respect to the cable. Can be reduced. Therefore, even when the deflection of the cable is reduced, when the rod member is driven from the first state to the second state, a force can be generated in the driving direction. Therefore, since the cable can be shortened, it can contribute to space saving correspondingly, and the load when a small joint portion such as a joint of a robot hand is driven can be reduced.

  Here, a plane that passes through the first attachment position, which is the attachment position of the cable in the rod member, and the second attachment position, which is the attachment position of the cable in the base member, and intersects with one axis is defined as a virtual plane. Wired along the plane, and at the first mounting position, is closer to the proximal end portion of the rod member in the first state than the distal end portion side of the rod member in the first state, and the distal end of the rod member in the second state It can be set as the aspect taken out toward the base end part side of the rod member in a 2nd state rather than the part side.

  According to this aspect, when the rod member is in the first state, the direction in which the cable is taken out is the direction approaching the joint member. For this reason, when shifting a rod member from a 1st state to a 2nd state, it becomes easy to apply force in the direction which a cable pushes out a rod member. Accordingly, since a large assist force can be applied at the rise when the rod member is moved, the rod member can be favorably operated when the rod member is repeatedly bent.

  On the other hand, a plane that passes through a first mounting position that is a cable mounting position on the rod member and a second mounting position that is a cable mounting position on the base member and intersects with one axis is defined as a virtual plane. The first end of the rod member in the first state and the proximal end of the rod member in the second state at the first mounting position It can also be set as the aspect taken out toward the front-end | tip part side of the rod member in a 2nd state rather than the part side.

  According to this aspect, when the rod member is in the first state, the direction in which the cable is taken out is a direction away from the joint member. For this reason, when the rod member shifts to the second state, a force for maintaining the second state can be applied and the rod member can be easily returned to the original position. Therefore, when the continuity which makes a rod member a 2nd state continuously is requested | required, high continuity can be exhibited.

  Moreover, it can be set as the aspect by which the folding | turning board which folds back the slack cable is standingly arranged in the position exceeding the 2nd attachment position seeing from the joint member in a base member. Since such a folded plate is erected, the cable can be prevented from escaping backward. As a result, the cable can be loosened more reliably.

  Furthermore, it can be set as the aspect by which the highly elastic member is used as a cable. Moreover, it can be set as the aspect by which the low-viscosity member is used as a cable. Thus, by using a highly elastic member or a low viscosity member as the cable, a large force can be applied when the base member is moved from the first state to the second state.

  The base member may be a palm member in the robot hand, the rod member may be a finger member in the robot hand, and the joint member may be a bent joint in the robot hand.

  Thus, the cable wiring structure according to the present invention can be suitably used as a robot hand.

  According to the cable wiring structure in the joint portion of the robot according to the present invention, it is possible to reduce a load when a small joint portion such as a joint of a robot hand is driven.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a side view of a robot hand including a cable wiring structure according to an embodiment of the present invention. As shown in FIG. 1, the robot hand 1 according to the present embodiment includes a palm member 2 serving as a base member. A bending joint 3 serving as a joint member is attached to the palm member 2. Furthermore, a finger member 4 that is a rod member is attached to the palm member 2 via a bending joint 3.

  The finger member 4 can be rotated around the rotation axis of the bending joint 3 by rotating the bending joint 3. This rotational axis is one axis of the present invention. The finger member 4 rotates the bending joint 3 to be extended toward the upper side in FIG. 1 and the bending state is to rotate the bending joint 3 to bend and extend toward the left in FIG. It is possible to transition between states. This extended state is the first state of the present invention, and the bent state is the second state of the present invention.

  The finger member 4 includes a fingertip portion 41, a finger middle portion 42, and a finger base portion 43. A first joint member 44 is provided between the fingertip portion 41 and the finger middle portion 42, and the finger middle portion 42 and the finger base portion are provided. A second joint member 45 is provided between the second joint member 45 and the second joint member 45. Further, the bending joint 3 is attached to the finger base portion 43. The finger base portion 43 can be bent by the bending joint 3. The middle finger part 42 can be bent by the second joint member 45, and the fingertip part 41 can be bent by the first joint member 44. When the first joint member 44 and the second joint member 45 are not driven, the finger member 4 can be bent by the bending joint 3. In the present embodiment, the first joint member 44 and the second joint member 45 are not always bent, and the fingertip portion 41, the finger middle portion 42, and the finger base portion 43 of the finger member 4 are arranged in a straight line. Give an explanation.

  A cable 5 is wired between the palm member 2 and the finger member 4. The cable 5 in the palm member 2 is attached to the palm member 2 at the second attachment position P2. The second attachment position P2 is located on the back side (back side of the hand) of the finger member 4.

  Further, the cable 5 is attached to the finger member 4 at the first attachment position P1. The first attachment position P <b> 1 is located on the back side of the finger base portion 43 of the finger member 4 located in the vicinity of the bending joint 3. For this reason, when the finger member 4 is in the extended state, the first attachment position P1 is set to a position closer to the second attachment position P2 than when it is in the bent state.

  The cable 5 is wired along the virtual plane when a virtual plane that is orthogonal to the rotation axis of the bending joint 3 and passes through the first mounting position P1 and the second mounting position P2 is defined. In addition, the cable 5 is connected so that the straight line connecting the first attachment position P1 and the second attachment position P2 overlaps with the finger member 4 in the extended state so that it is closer to the distal end side of the finger member 4 than the bending joint 3. Wired.

  Furthermore, in the second attachment position P2, the cable 5 is closer to the fingertip side than the finger root side of the finger member 4 in the extended state, and in a direction closer to the fingertip side than the finger root side of the finger member 4 in the bent state. It is taken out and wired. Specifically, in the state shown in FIG. 1, it is taken out in a diagonally upward left direction. On the other hand, the cable 5 is closer to the fingertip side than the fingertip side of the finger member 4 in the extended state and closer to the fingertip side than the fingertip side of the finger member 4 in the bent state at the first attachment position P1. It is taken out in the direction and wired. Specifically, in the state shown in FIG. 1, it is taken out in a diagonally downward right direction.

  Further, the cable 5 is loosely wired with two bending points when the finger member 4 is in the extended state. Further, when the finger member 4 is in a bent state, the bending point is eliminated, and wiring is performed so as to form a gentle curve across the bending joint 3. On the other hand, a highly elastic material is used for the cable 5. Further, the cable 5 is made of a material having low viscosity and large internal hysteresis.

  Next, the operation of the cable wiring structure in the joint portion of the robot according to this embodiment will be described.

  In the cable wiring structure according to this embodiment, when the bending joint 3 is driven to move the finger member 4 between the extended state and the bending state, the load on the bending joint 3 and the finger member 4 can be reduced. it can. The operation will be described below. FIG. 2 is a side view schematically showing the robot hand 1.

  As shown by a solid line in FIG. 2, when the finger member 4 in the robot hand 1 is in the extended state, the cable 5 is in a generally N-shaped and slack state as shown by the solid line. From this state, as shown by the phantom line in FIG. 2, when the bending joint 3 is driven to move the finger member 4 to the bending state, the cable 5 changes to a gentle curve. Here, when the finger member 4 is in the extended state, the cable 5 has two bent portions. By having this bent portion, the load by the cable 5 can be reduced, but rather, the cable 5 tends to extend straight by the spring element of the cable 5.

  The force that the cable 5 tries to extend acts on the bending joint 3, and the force can be applied in the direction in which the finger member 4 is moved to the bent state. For this reason, even when the deflection of the cable 5 is reduced, a force can be generated in the driving direction of the finger member 4 when the finger member 4 is driven from the extended state to the bent state. Therefore, since the cable 5 can be shortened, it is possible to contribute to space saving and to reduce the load when the robot hand 1 is driven.

  Moreover, the cable 5 has high elasticity and low viscosity. By having such high elasticity, when the finger member 4 shifts from the extended state to the bent state, it becomes a force for pushing out the finger member 4, and the finger member 4 can be easily shifted to the bent state. Further, by having low viscosity, it is possible to prevent the cable 5 from becoming difficult to work with a force to extend straight. Therefore, the minute finger member 4 can be easily shifted to the bent state.

  On the other hand, when the finger member 4 transitions from the bent state to the extended state, a force for loosening the cable 5 is required, but compared with a bending operation that needs to provide a bending force for gripping and manipulation. In the extension operation, it is not particularly necessary to exert a working force on the extension side. For this reason, if it is below the maximum value of bending force, it is possible to exert the force for slackening the cable 5 on the extension side.

  Further, in the robot hand 1 according to the present embodiment, the first attachment position P <b> 1 is the finger base portion 43, and is in the vicinity of the bending joint 3. Here, in order to increase the force for assisting the movement of the finger member 4 by the cable 5 when the finger member 4 is shifted from the extended state to the bent state, it is preferable to make the curvature R of the cable 5 smaller. .

  At this time, as schematically shown in FIG. 3A, it is assumed that the first attachment position P1 is provided at a position far from the bending joint 3, for example, the fingertip portion 41 shown in FIG. In this case, the cable 5 exerts a free force between the first mounting position P1 and the second mounting position P2, and as shown in FIG. 3B, the curvature R tends to be uniform, and as a result. The curvature R becomes large. Therefore, the force for moving the finger member 4 cannot be increased. On the other hand, if the rigidity of the cable 5 can be increased, even if the first attachment position P1 is provided at a position far from the bending joint 3, the curvature R is not necessarily increased, and the finger member 4 is moved. A large force can be secured.

  In addition, as shown in FIG. 3A, when the first mounting position P1 is provided at a position far from the bending joint 3, the first mounting position is determined when the finger member 4 is moved from the extended state to the bent state. The moving distance of P1 becomes long. As a result, the length of the cable 5 must be increased, and space is required accordingly.

  In this regard, in the robot hand 1 according to the present embodiment, the first attachment position P1 is set in the vicinity of the bending joint 3 as schematically shown in FIG. For this reason, as shown in FIG.4 (b), the curvature R of the cable 5 can be made small. Therefore, the force for moving the finger member 4 can be increased.

  Furthermore, since the first attachment position P1 is set in the vicinity of the bending joint 3, when the finger member 4 is moved from the extended state to the bent state, the moving distance of the first attachment position P1 is shortened. There is no need to increase the length of the cable 5. Therefore, the space for housing the cable 5 can be reduced accordingly.

  Further, the cable 5 is in a direction that is closer to the fingertip side than the finger root side of the finger member 4 in the extended state and closer to the fingertip side than the finger root side of the finger member 4 in the bent state at the second attachment position P2. It is taken out and wired, and at the first attachment position P1, it is closer to the fingertip side than the fingertip side of the finger member 4 in the extended state, and closer to the fingertip side than the fingertip side of the finger member 4 in the bent state. It is taken out in the direction and wired. For this reason, the direction in which the cable 5 is taken out becomes the direction approaching the bending joint 3. For this reason, when the finger member 4 is shifted from the extended state to the bent state, it is easy to apply a force in the direction in which the cable 5 pushes the finger member 4. Therefore, since a large assist force can be applied at the rise when the finger member 4 is moved, the finger member 4 can be favorably operated when the finger member 4 is bent repeatedly.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, as schematically shown in FIG. 5A, a folded plate 10 that folds the slack cable 5 is erected at a position beyond the second attachment position P2 when viewed from the bending joint 3 of the palm member 2. It can also be set as an aspect. By providing the folded plate 10, as shown in FIG. 5 (b), when the finger member 4 is shifted from the extended state to the bent state, the slack cable 5 is surely placed in the direction in which the finger member 4 is in the bent state. Can be extruded.

  Moreover, although the said embodiment demonstrated the aspect in which the cable 5 is one, it can also be set as the aspect which provides the cable 5 with two or more. When a plurality of cables 5 are provided, it is conceivable that the cables 5A and 5B overlap each other as shown in FIG. Thus, if the cables 5A and 5B overlap each other, the length of the cable 5 may be insufficient when the finger member 4 is bent.

  Therefore, when a plurality of cables 5 are provided, they can be wired in a state where they are arranged in parallel along the axial direction of the bending joint 3, and can be attached with a highly flexible tape or knitted with a thread. By arranging the cables in parallel in this way, the effects described in the above embodiment can be achieved, and the cables 5 can be prevented from overlapping.

  Moreover, in the said embodiment, although the bending part at the time of wiring the cable 5 is provided in two places, if the bending part is two or more places, it can also be set as the aspect which provides more parts. Furthermore, in the above embodiment, the wiring structure is intended for the robot hand, but other joint parts such as the elbow part of the robot arm can also be targeted.

  Moreover, in the said embodiment, the cable 5 is a fingertip side rather than the finger base side of the finger member 4 in the extended state in the 2nd attachment position P2, and is a fingertip rather than the finger base side of the finger member 4 in a bending state. The first finger is at the first attachment position P1 and is closer to the finger base than the fingertip side of the finger member 4 in the extended state, and more than the fingertip side of the finger member 4 in the bent state. It is taken out and wired in the direction of the finger base side. On the other hand, in the second attachment position P2, the finger member 4 is in the extended state and is closer to the fingertip side than the fingertip side, and is in the direction of the fingertip side of the finger member 4 in the bent state. In the first attachment position P1, the direction that is closer to the fingertip side than the finger root side of the finger member 4 in the extended state and closer to the fingertip side than the finger root side of the finger member 4 in the bent state It is taken out and wired. According to this aspect, when the finger member 4 is in the extended state, the direction in which the cable 5 is taken out is a direction away from the bending joint 3. For this reason, when the finger member 4 shifts to the bent state, a force for maintaining the bent state can be applied and the finger member 4 can be easily returned to the original position. Therefore, when the continuity which makes the finger member 4 bend continuously is requested | required, high continuity can be exhibited.

  Furthermore, in the said embodiment, the 1st joint member 44 and the 2nd joint member 45 are not always bent, and the fingertip part 41 in the finger member 4, the finger middle part 42, and the finger base part 43 were arranged in linear form. Although described in the state, it is not limited to this mode. For example, the first joint member 44 between the fingertip portion 41 and the finger middle portion 42 is bent, the second joint member 45 between the finger middle portion 42 and the finger base portion 43 is bent, or both are bent. It can also be set as the mode which is doing.

It is a side view of a robot hand. It is a typical side view explaining movement of a robot hand. (A) is a schematic side view of the robot hand when a cable is attached to the fingertip part, and (b) is an explanatory diagram for explaining the curvature of the cable in the case of (a). (A) is a typical side view of the robot hand according to the present embodiment, and (b) is an explanatory diagram for explaining the curvature of the cable in the case of (a). (A) is a typical side view concerning other examples of a robot hand, (b) is an explanatory view for explaining a curvature of a cable in the case of (a). It is a typical side view showing the state where a cable overlaps when providing a plurality of cables.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Robot hand, 2 ... Palm member, 3 ... Bending joint, 4 ... Finger member, 5 (5A, 5B) ... Cable, 10 ... Folding plate, 41 ... Finger tip part, 42 ... Finger middle part, 43 ... Finger base part, 44 ... 1st joint member, 45 ... 2nd joint member, P1 ... 1st attachment position, P2 ... 2nd attachment position, R ... curvature.

Claims (6)

A rod member is attached to a base member via a joint member, and the rod member can be bent around one axis of the joint member with respect to the base member, and between the rod member and the base member Cable wiring in the joint part of the robot wired to
The attachment position of the cable in the rod member is defined as a first attachment position, and the attachment position of the cable in the base member is defined as a second attachment position,
The first attachment position is set in the vicinity of the joint member in the rod member,
A state in which the tip of the rod member relative to the base end attached to the joint member is relatively close to the second attachment position is a first state, and the tip of the rod member is the second attachment. When the state that is relatively far from the position is the second state,
The first attachment position is set to a position closer to the second attachment position when the rod member is in the first state than when the rod member is in the second state;
When the rod member is in the first state, the cable is loosely wired with two or more bending points,
The cable wiring structure in the joint portion of the robot, wherein when the rod member is in the second state, the cable is wired with the two or more bending points eliminated. A plane that passes through the first mounting position that is the mounting position of the cable in the rod member and the second mounting position that is the mounting position of the cable in the base member and intersects the one axis is defined as a virtual plane,
The cable is wired along the virtual plane, and at the first attachment position, the cable is closer to the proximal end of the rod member in the first state than to the distal end side of the rod member in the first state, 2. The cable wiring structure according to claim 1, wherein the cable wiring structure is taken out from a distal end portion side of the rod member in the second state toward a proximal end portion side of the rod member in the second state. A plane that passes through the first mounting position that is the mounting position of the cable in the rod member and the second mounting position that is the mounting position of the cable in the base member and intersects the one axis is defined as a virtual plane,
The cable is wired along the virtual plane, and at the first attachment position, the cable is closer to the distal end side of the rod member in the first state than the proximal end side of the rod member in the first state, 2. The cable wiring structure according to claim 1, wherein the cable wiring structure is taken out from a proximal end portion side of the rod member in the second state toward a distal end portion side of the rod member in the second state.   4. The folding plate according to claim 1, wherein a folded plate for folding the slack cable is provided at a position beyond the second attachment position when viewed from the joint member of the base member. 5. A cable wiring structure in the joint portion of the described robot.   The cable wiring structure in the joint portion of the robot according to claim 1, wherein a high-elasticity member is used as the cable. The base member is a palm member in a robot hand,
The rod member is a finger member in the robot hand,
6. The cable wiring structure in the joint portion of the robot according to claim 1 , wherein the joint member is a bent joint in the robot hand.

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