JP5135464B1 - Robot arm, external force detection transmission device and shock absorber for robot arm - Google Patents

Abstract

An object of the present invention is to provide a buffer function that reduces damage caused by an external force having a force component in that direction applied to the arm portion in any of two or more directions in a non-powered state. To do.
An outer ring member connected to an arm portion and an inner ring member connected to a joint mechanism are orthogonal to both the direction of relative rotation around a fixed shaft and the longitudinal direction of the fixed shaft and the arm. Any of the relative rotation directions around the axis to be connected is connected in a relative movement state. In any of the two relative movement directions, when an external force having a force component in that direction exceeds a certain value is applied to the arm portion, the detection transmission member operates in a non-powered state using the external force, and interlocks with this. Thus, the power transmission state in which the relative movement in the relative movement direction corresponding to the force component of the external force is prohibited is canceled in the non-powered state.
[Selection] Figure 1

Description

  The present invention relates to a robot arm having a buffer function that reduces an impact when an external force is applied to an arm portion, and to an external force detection transmission device and a buffer device for the robot arm.

  Conventional robot arms are often used as industrial robots in various product manufacturing processes. An industrial robot is usually fixedly placed at a predetermined location on an automated production line and operates, so that it is possible that a situation in which a robot arm collides with surrounding obstacles will not occur. Not planned. In addition, there are many humans around industrial robots that are placed on automated production lines, or even if there are humans, they are specialized workers. There are no plans for a collision. On the other hand, in recent years, the field of use of robot arms has expanded, and active use of robot arms is expected in human care, medical practice, or at home. In such a use situation, it is expected that surrounding obstacles or humans collide with the robot arm. Therefore, even when an obstacle or a human collides with the robot arm, a technique is required to reduce the impact of the obstacle, the human, or the robot arm by reducing the impact.

Patent Document 1 discloses a robot arm that is provided with a flexible mechanism such as a damper or a spring at a joint portion, and can reduce the impact of the collision with the obstacle at the time of collision with the obstacle.
Further, Patent Document 2 discloses a plurality of circular convex portions arranged circumferentially on a joint surface of a servo horn connected to a servo device, and a plurality of concave portions provided on a joint surface of a connecting member. A robot arm is disclosed that is configured such that the rotational force of a servo device is transmitted to a coupling member by driving the arm unit connected to the coupling member. In this robot arm, the joint surface of the servo horn and the joint surface of the connecting member are biased toward each other by tightening the washer having the property of an elastic body. The connection with the recess is maintained. When a robot with this robot arm causes a fall accident and a large force is applied in the arm movement direction (direction of freedom), the convex part of the servo horn comes out of the concave part of the connecting member due to the elastic deformation of the washer. Is released. As a result, the arm portion is released from the servo device side and can freely move in the direction of freedom, thereby exhibiting a buffer function.

Since the flexible mechanism of the robot arm disclosed in Patent Document 1 is configured to exhibit a buffer function even in a non-powered state, a situation in which the buffer function cannot be performed due to electrical trouble does not occur. In this respect, there is an advantage that the reliability is high as compared with the configuration in which the buffer function is realized by electrical control . However while, the robot arm is the instantaneous impact at the time of collision can be buffered with parasitic state by a flexible mechanism, or continues to move the arm portion after collision toward the obstacle, even after the collision obstacle The contact pressure between the arm portion and the obstacle when the object pushes the arm portion cannot be reduced in the non-powered state. Electrical control is used in the configuration for reducing the contact pressure after the collision. Specifically, considering the detection result of the angle sensor provided at the joint and the influence of the flexible mechanism, the control target angle of the joint after the collision is corrected to be the angle detected after the collision, and the contact after the collision Drive control is performed so that the pressure is ideally zero. For this reason, the robot arm disclosed in Patent Document 1 cannot realize a buffer function in a broad sense including not only a momentary impact at the time of collision but also a reduction in pushing force after the collision in a non-powered state. In terms of reliability.

  Further, the flexible mechanism included in the robot arm disclosed in Patent Document 1 is disposed in a driving force transmission path for driving the arm portion. For this reason, when a robot arm is operated under a condition where a heavy driving load exceeding a certain level is applied, such as when moving a heavy object on the arm, the buffering function of the flexible mechanism is exhibited even if the arm does not collide with an obstacle. Will be. In this case, the movement position of the arm part deviates from the control target value, and it becomes difficult to realize appropriate drive control of the arm part. Therefore, the usage mode of such a robot arm is limited to a situation where a driving load for moving a relatively light object is small. On the other hand, if the flexibility of the flexible mechanism is reduced in order to realize appropriate drive control even under a large driving load, the buffer function at the time of collision becomes insufficient, and the target buffer function cannot be obtained.

  Further, in the robot arm disclosed in Patent Document 2, the arm portion is released from the servo device side after receiving the impact in the direction of freedom, so that the movement in the direction of freedom is free and the buffer function is exhibited. Is done. For this reason, according to this robot arm, a buffer function in a broad sense including not only a momentary impact reduction at the time of collision but also a reduction in contact pressure after the collision (hereinafter simply referred to as a “buffer function” in a broad sense). Can be realized without power supply and is highly reliable. However, even when this robot arm is operated under a condition where a large driving load exceeding a certain level is applied, such as when a heavy object is moved by the arm unit, the washer is not even when the arm unit collides with an obstacle. Due to the elastic deformation of the servo horn, the convex portion of the servo horn comes out of the concave portion of the connecting member, making it difficult to realize appropriate drive control of the robot arm. Therefore, the usage mode of the robot arm is also limited to a situation where the driving load for moving a relatively light object is small. On the other hand, if the elasticity of the washer is increased in order to realize appropriate drive control even under a situation where a large drive load is applied, the buffer function becomes insufficient, and the target buffer function cannot be obtained.

  Therefore, unless the external force of a certain level is applied to the arm part due to a collision with an obstacle or a human being, the present inventors do not exhibit a buffer function even under a situation where a large driving load is applied, and once the external force is applied. We have developed a highly reliable robot arm that can exhibit a buffer function when no power is applied. This robot arm is configured such that an arm portion attached to a joint mechanism with one degree of freedom having one joint portion rotates in the direction of freedom using the joint mechanism as a fulcrum. The joint part of the robot arm is composed of an outer disk (connecting part) that rotates along the direction of freedom and an inner disk (connected part) that can rotate inside the outer disk. The inner disk is connected to a driving source and rotates by a driving force from the driving source. The outer disk is connected to the arm portion, and the outer disk and the arm portion rotate together. On the inner disk, an inner slider (power transmission canceling means) urged radially outward is provided, and the urging direction front end is radially outward from the peripheral edge of the inner disk due to the urging. Project to Normally, the urging direction front end portion of the inner slider on the inner disk is maintained in a state of being fitted into a slider insertion recess provided in a part of the peripheral edge portion on the outer disk. Accordingly, the relative movement between the inner disk and the outer disk is prohibited during normal times, and these rotate integrally, so that the arm portion can be rotated in the direction of freedom by the driving force from the driving source.

  The side surface of the arm portion facing the direction of freedom of the robot arm is provided with an impacted plate that is pushed and displaced by external force from the direction of freedom. When the impacted plate is displaced, the inner slider on the inner disk slides radially inward via the link mechanism, and the connection between the inner slider and the outer disk is released. Thereby, the inner slider and the outer disk can be relatively moved. As a result, the arm portion is released from the drive source side and can freely move in the direction of freedom, thereby exhibiting a buffer function.

  According to this robot arm, even when the robot arm is operated under a large driving load, such as when a heavy object is moved by the arm, the driving load has the action of sliding the inner slider inward in the radial direction. Therefore, the connection state between the inner disk and the outer disk is maintained. On the other hand, once a collision with an obstacle or a person occurs and the impacted plate of the arm portion is displaced by the external force, the connection state between the inner disk and the outer disk is released, and the buffer function is exhibited. Moreover, this buffer function is realized without using electrical control, and the buffer function is exhibited in a non-powered state.

However, this robot arm has a problem that the buffer function can be exhibited only with respect to an external force having a force component in a certain direction or more in one direction, which is a normal direction with respect to the plate surface of the impacted plate. It was.
In addition, this robot arm has a problem in that it can detect an external force having a force component in a certain direction or more only in one direction, which is a normal direction with respect to the plate surface of the colliding plate.

The present invention has been made in view of the above problems, and the object of the present invention is when an external force having a force component in a certain direction is applied to the arm portion in any of two or more directions. Another object of the present invention is to provide a highly reliable robot arm that can exhibit a buffer function that reduces damage caused by the external force in a non-powered state, and an external force detection transmission device and a buffer device for the robot arm.
In addition, the present invention provides an external force detection and transmission device for a robot arm that can detect an external force in any of two or more directions when an external force having a force component in that direction exceeds a certain value is applied to the arm portion. Also aimed.

According to a first aspect of the present invention, a driving source, an arm portion, an object handling portion connected to one longitudinal end of the arm portion, and the arm portion in a predetermined degree of freedom direction by a driving force from the driving source. The joint mechanism to be moved, the connecting portion connected to the arm portion, and the connected portion connected to the connecting portion are connected in a relatively movable state, and between the connecting portion and the connected portion. A connection release mechanism that can be switched in a non-powered state from a power transmission state in which relative movement is prohibited to a power transmission release state in which the prohibition of relative movement is canceled, and in the power transmission state by a driving force from the drive source The robot arm that moves the arm part in the predetermined direction of freedom, wherein the connection release mechanism connects the connection part and the connected part so as to be relatively movable in two or more relative movement directions. , The two or more relative For any of the dynamic direction, operating in the passive state by utilizing the external force when the external force having the direction of the force component constant or applied to the arm portion, even if an external force is applied to the object handling unit operation and has no external force detecting transmission mechanism having a detection transmission member, the connection release mechanism, the detection in conjunction with the operation of the transmission member, the relative movement direction corresponding to the force component external force applied to the arm portion has The power transmission state in which relative movement is prohibited is switched to the power transmission release state.
In this robot arm, the force component in the direction (hereinafter referred to as “specific force component”) is constant in any of two or more relative movement directions in which the connecting portion and the connected portion in the connection releasing mechanism can move relative to each other. When the external force having the above is applied to the arm portion, the detection transmission member moves in a non-powered state by using the external force, and the fact that the external force has been received can be transmitted to the connection release mechanism. Then, when the external force is applied to the arm portion and the detection transmission member is moved by the external force, the connection release mechanism is linked to the relative movement direction corresponding to the specific force component of the external force applied to the arm portion. The power transmission state in which relative movement is prohibited is switched to the release state. As a result, the relative movement between the connecting part and the connected part in the relative movement direction becomes free, and the specific force component of the external force applied to the arm part can be passed, and the buffer function that reduces damage due to the external force Can be demonstrated in a non-powered state.
As described above, according to the robot arm, when an external force having a force component in a certain direction is applied to the arm portion in any of two or more directions, the external force is detected in a non-powered state, and The buffer function that reduces damage caused by the external force can be exhibited in a non-powered state.

According to a second aspect of the present invention, in the robot arm of the first aspect, the external force detection and transmission mechanism includes two or more detection transmission members that differ for each of the two or more relative movement directions, and is added to the arm unit. Only the detection transmission member in the relative movement direction corresponding to the force component of the external force is configured to operate, and the connection release mechanism is operated in conjunction with the operation of each detection transmission member. The power transmission state in which the relative movement only in the relative movement direction corresponding to is prohibited is switched to the power transmission released state.
In this robot arm, the prohibition of relative movement of the connected portion and the connecting portion is canceled only in the relative moving direction corresponding to the specific force component of the external force applied to the arm portion. Thereby, only the buffer function in the direction necessary for buffering the external force applied to the arm portion is exhibited, and the buffer function in the unnecessary direction is not exhibited.

The invention according to claim 3 is the robot arm according to claim 1 or 2, wherein the connection release mechanism is a single connecting portion, and the connecting portion and the connected portion are relatively moved in the two or more relative movement directions. It is characterized by being connected movably.
In this robot arm, the connection release mechanism can be reduced in size compared to the case where the connected portion and the connecting portion are relatively movable in the two or more relative movement directions at a plurality of connecting locations. is there.

According to a fourth aspect of the present invention, in the robot arm according to any one of the first to third aspects, the detection transmission member of the external force detection transmission mechanism is configured to be movable along the longitudinal direction of the arm portion. The arm portion includes an arm side surface member that can be displaced in a direction to receive the force component by receiving an external force having a certain amount or more of a force component in a direction orthogonal to the longitudinal direction of the arm portion. The external force detection / transmission mechanism includes a link mechanism that moves the detection transmission member along the longitudinal direction of the arm portion in conjunction with the displacement of the arm side surface member.
In this robot arm, it is possible to easily realize a configuration capable of detecting an external force applied to the arm portion from a direction orthogonal to the longitudinal direction of the arm portion and smoothly transmitting it to the connection release mechanism.

According to a fifth aspect of the present invention, in the robot arm according to any one of the first to third aspects, the arm portion has a force component in a direction perpendicular to the longitudinal direction of the arm portion at a certain level or more. An arm side surface member configured by a fluid sealing member having flexibility that can be deformed by receiving an external force is provided, and the detection transmission member of the external force detection transmission mechanism is adapted to move the sealed fluid due to deformation of the fluid sealing member. It is configured to move in conjunction with each other.
In this robot arm, since the arm side surface member that receives external force is configured by a fluid sealing member having flexibility, the instantaneous moment at the time of collision is higher than when the arm side surface member is configured by a highly rigid material. Effective in reducing impact. Further, since the detection transmission member is configured to move in conjunction with the movement of the sealed fluid due to the deformation of the fluid sealing member, the deformation of the fluid sealing member can be performed no matter what direction external force is applied to the fluid sealing member. The stable movement of the sealed fluid can be realized, and the detection transmission member can be moved stably. Therefore, it becomes easy to deal with a wide range of force directions.

According to a sixth aspect of the present invention, there is provided a drive source, an arm portion, an object handling portion connected to one longitudinal end of the arm portion, and the arm portion with a predetermined degree of freedom by a driving force from the drive source. A joint mechanism that moves in a direction, a connecting portion that is connected to the arm portion, and a connected portion that is connected to the connecting portion are connected in a relatively movable state, and the connecting portion and the connected portion A connection release mechanism that can be switched in a non-powered state from a power transmission state in which relative movement is prohibited to a power transmission release state in which the prohibition of relative movement is canceled, and driving from the drive source in the power transmission state An external force detection and transmission device for a robot arm that detects an external force applied to the arm portion and transmits the external force to the disconnection mechanism in a robot arm that moves the arm portion in the direction of the predetermined degree of freedom by force. For any direction of the upper, by utilizing the external force when the external force having the direction of the force component constant or applied to the arm portion operating in the passive state, even if an external force is applied to the object handling unit It has a detection transmission member which does not operate .
In the external force detection and transmission device for a robot arm, in any of two or more directions (detection directions), when an external force having a force component in a certain direction is applied to the arm portion, the external force is used. Then, the detection transmission member moves, and the external force can be detected in a non-powered state and transmitted to the connection release mechanism. In addition, if the relative movement direction of the connecting part and the connected part in the connection release mechanism of the robot arm is set to 2 or more and the detection direction in the external force detection and transmission device is made to correspond to this, the direction of any of the two or more directions is determined. In addition, it is possible to exhibit a buffer function that can reduce damage caused by an external force having a force component in that direction over a certain level.

According to a seventh aspect of the present invention, there is provided a drive source, an arm portion, an object handling portion connected to one longitudinal end portion of the arm portion, and the arm portion with a predetermined degree of freedom by a driving force from the drive source. For any of the joint mechanism that moves in the direction and the two or more directions, when an external force having a certain amount of force component in that direction is applied to the arm portion, the external force is used to operate in a non-powered state, In a shock absorber for a robot arm used for a robot arm having an external force detection transmission mechanism provided with a detection transmission member that does not operate even when an external force is applied to the object handling unit, the connection unit connected to the arm unit and the connection A connected portion connected to the portion is connected in a state of being relatively movable in two or more relative movement directions for receiving the force components in the two or more directions, and between the connected portion and the connected portion. Relative movement It has a connection release mechanism that can be switched in a non-powered state from a prohibited power transmission state to a power transmission release state that releases the prohibition of relative movement, and is added to the arm portion in conjunction with the operation of the detection transmission member Switching from the power transmission state in which the relative movement in the relative movement direction corresponding to the force component of the external force is prohibited is switched to the power transmission release state.
In this shock absorber for a robot arm, an external force having a certain force component (specific force component) in a certain direction in any of two or more relative movement directions in which the connecting portion and the connected portion can move relative to each other is provided on the arm. When the sensor is added to the part, in conjunction with the movement of the detection transmission member that detects this, the prohibition of relative movement in the relative movement direction that can reduce damage due to the external force is released in the non-powered state, and the buffer function is demonstrated. Is done.

  According to the present invention, in any of two or more directions, when an external force having a certain amount of force component in that direction is applied to the arm portion, a buffer function that reduces damage caused by the external force can be exhibited in a non-powered state. An excellent effect of providing a highly reliable robot arm can be obtained.

It is a front view of the robot arm in an embodiment. It is a side view of the robot arm. It is a perspective view which shows the principal part for implement | achieving the buffer function in the robot arm. (A) And (b) is sectional drawing which shows the structure and operation | movement of the external force detection transmission mechanism in embodiment. (A) And (b) is sectional drawing which shows the structure and operation | movement of a buffer mechanism in embodiment. It is a disassembled perspective view of the buffer mechanism. It is a disassembled perspective view of the inner ring member in an embodiment. (A) And (b) is explanatory drawing for demonstrating operation | movement of a damper spring when the external force which has more than fixed force component of the detection direction of a 1st detection transmission mechanism is added to an arm part. (A) And (b) is explanatory drawing for demonstrating operation | movement of a damper spring when the external force which has more than fixed force component of the detection direction of a 2nd detection transmission mechanism is added to an arm part. It is the elements on larger scale of the joint mechanism and arm part in the robot arm of a modification. (A) And (b) is explanatory drawing which shows the structure and operation | movement of the external force detection transmission mechanism in a modification. It is a perspective view which shows the structure of the joint mechanism in a modification. (A) And (b) is explanatory drawing for demonstrating the structure and operation | movement regarding a buffer function in the joint mechanism. It is explanatory drawing which shows the other example of the external force detection transmission mechanism using the fluid sealing member which has the softness | flexibility which can deform | transform by receiving external force.

Hereinafter, an embodiment of a robot arm according to the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a robot arm in the present embodiment.
FIG. 2 is a side view of the robot arm in the present embodiment.
The robot arm according to the present embodiment mainly includes a pedestal 10, a joint mechanism 20, and an arm unit 30. In this embodiment, an example in which a robot arm is mounted on a pedestal will be described. However, the robot arm according to the present invention is not limited to this, and for example, a humanoid robot arm, leg, head (neck) Including joints) and body parts (including hip joints).

  The pedestal 10 of this robot arm has a wheel 11 composed of an omni wheel or the like attached to the bottom surface of the lower plate 15. Thus, the robot arm is configured to move in all directions by the rotation of the wheels 11. On the upper surface of the lower plate 15 of the pedestal 10, a drive control unit 12 that performs drive control of the robot arm is mounted. The drive control unit 12 is configured by an electric circuit or the like on which an arithmetic device such as a CPU, a ROM that stores a drive control program, a data storage device such as a RAM that temporarily stores data, and the like are mounted. The drive control unit 12 realizes various operations such as movement of the arm unit 30 when the arithmetic device executes a predetermined drive control program. In addition, the pedestal 10 supports the upper plate 14 by six legs 13 extending upward in the vertical direction from the upper surface of the lower plate 15.

  The joint mechanism 20 of the robot arm realizes two degrees of freedom by a lower joint portion 21 and an upper joint portion 22 each having one degree of freedom. A turning drive motor 23 is mounted inside the casing of the lower joint portion 21. The turning drive motor 23 is disposed inside the casing of the lower joint portion 21 so that the motor shaft is along the vertical direction. The turning drive motor 23 is fixed to the upper plate 14 of the base 10. The base 22a of the upper joint portion 22 is fixed to the housing of the lower joint portion 21 via a harmonic drive (registered trademark). Therefore, when the turning drive motor 23 is rotationally driven according to the control command of the drive control unit 12, the portion on the arm unit 30 side including the upper joint portion 22 of the joint mechanism 20 in the robot arm is centered on the motor shaft. Relatively moves relative to the base 10. In this embodiment, since the pedestal 10 is fixed to the floor surface, the arm unit 30 can be swung around the motor shaft 23 by rotating the swivel drive motor.

  The upper joint portion 22 of the joint mechanism 20 is provided with two side plates 24, and the two side plates 24 are integrally formed by a connecting plate 24a. The two side plates 24 are rotatably supported by the base 22a of the upper joint portion 22. The upper joint portion 22 is mounted with the vertical rotation drive motor 25 so that the motor shaft of the vertical rotation drive motor 25 faces the horizontal direction (left and right direction in FIG. 1). The motor shaft of the vertical rotation drive motor 25 is attached to one of the two side plates 24 (the left side plate 24 in FIG. 1) via a speed reduction mechanism 26 such as a harmonic drive (registered trademark). Thus, when the vertical rotation drive motor 25 is rotationally driven in accordance with the control command of the drive control unit 12, the base 22a in which the two side plates 24 in the upper joint portion 22 are fixed to the lower joint portion 21 with the motor shaft as the rotation center. Moves relative to. A buffer mechanism 40 as a connection release mechanism is fixed to the upper part of the two side plates 24, and the arm portion 30 is attached to the two side plates 24 in the upper joint portion 22 via the buffer mechanism 40. . Therefore, by rotating the drive motor 25 for vertical rotation, the arm portion 30 can be rotated in the vertical direction with the motor shaft as the rotation center.

  The arm portion 30 of the robot arm includes a base portion 31 extending in the longitudinal direction of the arm, and an arm side surface member 32 attached to the base portion 31 so as to be displaceable in a direction orthogonal to the longitudinal direction of the arm portion (arm side surface direction). It is composed of The end of the base 31 on the side of the joint mechanism 20 is attached to a buffer mechanism 40 mounted on the joint mechanism 20. A hand 50 that is a gripping part for gripping an object to be transported by a robot arm is attached to an end of the base 31 on the tip side of the arm.

  The hand 50 includes a fixed hand unit 51, a movable hand unit 52, and a slide drive unit 53 provided therebetween. The slide drive unit 53 can drive the fixed hand unit 51 and the movable hand unit 52 in the direction of approaching / separating according to the control command of the drive control unit 12. Thereby, the operation | movement which clamps a conveyance target object between the fixed hand part 51 and the movable hand part 52 can be performed.

  As described above, the robot arm according to the present embodiment has two degrees of freedom: the pivoting movement of the arm unit 30 around the rotation axis extending in the vertical direction and the vertical rotation of the arm unit 30 around the rotation axis extending in the horizontal direction. Can be realized. And the conveyance object hold | gripped by 50 within this range of two degrees of freedom can be conveyed freely.

Next, the buffer function of the robot arm, which is a characteristic part of the present invention, will be described.
FIG. 3 is a perspective view showing a main part for realizing a buffer function in the robot arm of the present embodiment.
The robot arm according to the present embodiment applies an external force to the arm unit 30 when an external force having a certain force component in the direction is applied to the arm unit 30 in any direction orthogonal to the longitudinal direction of the arm unit 30. A configuration is adopted in which a buffering function that detects in a non-powered state and reduces damage caused by the external force can be exhibited in a non-powered state. This configuration mainly includes an external force detection / transmission mechanism (external force detection / transmission device for a robot arm) provided in the arm unit 30 that detects such an external force, and a joint mechanism that exhibits a buffer function according to the detection result. 20 is realized by the buffer mechanism 40 provided in the system 20.

  FIG. 3 shows a state in which the arm unit 30 on which the external force detection transmission mechanism is mounted and the buffer mechanism 40 are separated, but in a state after assembly, the base 31 of the arm unit 30 is the housing of the buffer mechanism 40. It is fixed to the two fixing members 41 on the body.

4A and 4B are cross-sectional views showing the configuration and operation of the external force detection transmission mechanism in the present embodiment.
The external force detection and transmission mechanism mounted on the arm portion 30 includes four fixing members 33A and 33B fixed to the inner wall of the cylindrical arm side surface member 32 and the base portion 31 of the arm portion 30 along the longitudinal direction of the arm. Movement of the slide members 34A and 34B, the four slide members 34A and 34B attached so as to be slidable, the connecting rods 35A and 35B for connecting the fixing members 33A and 33B and the slide members 34A and 34B, respectively. And slide rods 36A and 36B serving as detection transmission members that slide in conjunction with each other.

  The four fixing members 33A and 33B are arranged at positions where the circumferential positions of the cylindrical arm side surface members 32 are shifted from each other by 90 degrees. The four slide members 34A and 34B are arranged at positions facing the corresponding fixing members 33A and 33B, respectively. The fixing members 33A, 33B and the connecting rods 35A, 35B and the slide members 34A, 34B and the connecting rods 35A, 35B are all connected via ball joints.

  In the present embodiment, two fixing members 33A that face each other, and two slide members 34A, a connecting rod 35A, and a slide rod 36A that correspond to the fixing member 33A, constitute a set to constitute a first detection transmission mechanism. Yes. Further, the two detection members 33B facing each other, and the two slide members 34B, the connecting rod 35B, and the slide rod 36B corresponding to the two fixing members 33B constitute a pair to constitute a second detection transmission mechanism. The first detection transmission mechanism can detect and transmit an external force having a force component in a direction along the direction in which the two fixing members 33 </ b> A face each other (the left-right direction in FIG. 4) beyond a certain level. The second detection transmission mechanism can detect and transmit an external force having a force component in a direction along the direction in which the two fixing members 33B face each other (the front-rear direction in FIG. 4) to the buffer mechanism 40. . Each detection transmission mechanism functions like a parallel crank mechanism.

  In the arm portion 30 in the normal state shown in FIG. 4A, the arm side member 32 of the moving arm portion 30 collides with an obstacle, a human being, etc. (hereinafter referred to as “obstacle etc.”) or moved. An obstacle or the like may collide with the arm side member 32 of the arm portion 30 that is moving or not moving. In such a case, for example, when an external force having a force component in the left-right direction in FIG. 4, that is, the detection direction of the first detection transmission mechanism, exceeds a certain level, 32 is displaced by about 5 mm, for example, relative to the base 31 of the arm 30 in a direction (leftward in FIG. 4) for receiving the force component of the external force. Due to this displacement, an instantaneous impact when an obstacle or the like collides with the arm side member 32 is alleviated.

  Further, due to this displacement, the fixing member 33A on the side receiving the external force in the first detection transmission mechanism (the fixing member 33A on the right side in FIG. 4) approaches the base 31. The slide member 34A connected to the fixing member 33A via the connecting rod 35A slides toward the end opposite to the end in the arm longitudinal direction where the slide rod 36A is provided. On the other hand, the fixing member 33A on the opposite side to the side receiving the external force in the first detection transmission mechanism (the fixing member 33A on the left side in FIG. 4) is separated from the base 31. Then, the slide member 34A connected to the fixing member 33A via the connection rod 35A slides toward the end in the arm longitudinal direction where the slide rod 36A is provided. Due to the sliding movement of the sliding member 34A, the slide rod 36A is pushed by the end of the sliding member 34A and slides downward from the normal position shown in FIG. 4A toward the buffer mechanism 40 in FIG. As shown in FIG. 4B, it is located at the detection transmission position.

  When the arm side member 32 receives an external force from the left side in FIG. 4, the fixing member 33A on the opposite side to the side receiving the external force in the first detection transmission mechanism, that is, the right fixing member 33A in FIG. Leaves the base 31. Then, the slide member 34A connected to the fixing member 33A via the connecting rod 35A slides toward the arm longitudinal direction end on the slide rod 36A side, and the slide rod 36A is shown by the arrow in FIG. Slide in the direction (downward in the figure). Therefore, when an external force having a force component in the left-right direction in FIG. 4, that is, the detection direction of the first detection transmission mechanism, is applied to the arm side surface member 32, the slide rod may be directed in the right direction or the left direction in the figure. 36A slides in the direction of the arrow in FIG. 4B (downward in the figure), that is, toward the buffer mechanism 40.

  Similarly, for example, when an external force having a force component in the front-rear direction of the paper surface in FIG. 4, that is, the detection direction of the second detection transmission mechanism, exceeds a certain level, The member 32 is displaced in a direction to flow the force component of the external force (the back side in FIG. 4). Due to this displacement, the fixing member 33B on the side receiving the external force in the second detection transmission mechanism (the fixing member 33B on the near side in FIG. 4) approaches the base 31. Then, the slide member 34B connected to the fixing member 33B via the connecting rod 35B slides toward the end opposite to the end in the arm longitudinal direction where the slide rod 36B is provided. On the other hand, the fixing member 33B on the opposite side to the side receiving the external force in the second detection transmission mechanism (the fixing member 33B on the back side in FIG. 4) is separated from the base 31. Then, the slide member 34B connected to the fixing member 33B via the connecting rod 35B slides toward the end in the arm longitudinal direction where the slide rod 36B is provided. As the slide member 34B slides, the slide rod 36B is pushed by the end of the slide member 34B, slides downward from the normal position in FIG. 4, that is, toward the buffer mechanism 40, and is positioned at the detection transmission position. The same applies to the case where the arm side member 32 receives an external force from the back side in FIG.

  In this embodiment, since each fixing member 33A, 33B and each slide member 34A, 34B are connected by connecting rods 35A, 35B having ball joints, the fixing member 33A of the first detection transmission mechanism, The fixing member 33B of the second detection transmission mechanism can be displaced independently. Therefore, in the present embodiment, the external force in the detection direction of the first detection transmission mechanism and the external force in the detection direction of the second detection transmission mechanism can be distinguished and detected.

  When an external force having a certain amount or more of the force component in the detection direction of the first detection transmission mechanism and the force component in the detection direction of the second detection transmission mechanism is applied to the arm side surface member 32, both detection transmission mechanisms operate. Thus, the two slide rods 36 </ b> A and 36 </ b> B slide toward the buffer mechanism 40. Therefore, in the present embodiment, even when an external force is received from any of the circumferential directions of the cylindrical arm side member 32, the arm side member 32 is displaced in a direction to receive the external force, and the slide side 36A, 36B is interposed. Thus, detection of external force can be transmitted to the buffer mechanism 40.

Next, the configuration and operation of the buffer mechanism will be described in the case where an external force having a certain amount of force component in the detection direction of the first detection transmission mechanism is applied to the arm side member 32 of the arm unit 30.
5A and 5B are cross-sectional views showing the configuration and operation of the buffer mechanism 40 in the present embodiment.
The buffer mechanism 40 of this embodiment includes an outer ring member (connecting portion) 42 and an inner ring member (connected portion) 43 that can rotate relative to the outer ring member 42 therein. A fixed shaft 46 is fixed to the inner ring member 43 so as to penetrate the rotation center axis thereof, and both ends of the fixed shaft 46 are connected to the side plate 24 of the upper joint portion 22 in the joint mechanism 20 as shown in FIG. It is fixed to. As shown in FIGS. 3 and 5, two fixing members 41 for fixing the base portion 31 of the arm portion 30 are formed on the outer wall of the outer ring member 42. The arm portion 30 is fixed to the outer ring member 42 through the two fixing members 41.

  As shown in FIGS. 5A and 5B, the inner ring member 43 includes an inner slider 44 </ b> A as a power transmission release unit that is urged radially outward by a compression spring 45 </ b> A. In a normal state where no obstacle or the like collides with the arm side member 32 of the arm portion 30, as shown in FIG. 5A, the inner slider 44A urged radially outward by the urging force of the compression spring 45A. The distal end portion protrudes radially outward from the peripheral edge of the inner ring member 43. In this state, the tip end portion of the inner slider 44A passes through a slider insertion recess 42a provided at a part of the peripheral edge on the outer ring member 42. The tip of the inner slider 44A abuts on the tip of the slide rod 36A located at the normal position, and the position (projecting position) of the inner slider 44A is held in this state. Therefore, in the normal state, the inner slider 44A prohibits the relative rotation of the inner ring member 43 and the outer ring member 42 about the fixed shaft 46, and the inner ring member 43 and the outer ring member 42 are integrated. Since the inner ring member 43 is fixed to the side plate 24 of the upper joint part 22 in the joint mechanism 20, the arm part 30 fixed to the outer ring member 42 drives the upper joint part 22 and the lower joint part 21 in the joint mechanism 20. It can move with.

  On the other hand, in the normal state shown in FIG. 5 (a), an external force having a force component in the detection direction of the first detection transmission mechanism exceeding a certain level is applied to the arm side member 32 of the arm portion 30, and the slide rod is located at the normal position. When 36A slides to the detection transmission position, the inner slider 44A located at the projecting position is pushed by the slide rod 36A, and the tip thereof is the periphery of the inner ring member 43 as shown in FIG. Slide to the retracted position where it is retracted to the inside. When the inner slider 44A moves to the retracted position shown in FIG. 5B in this way, the power transmission cancel state in which the power transmission state in which the relative rotation between the inner ring member 43 and the outer ring member 42 is prohibited is released. Therefore, the outer ring member 42 can freely rotate around the fixed shaft 46 with respect to the inner ring member 43.

  Therefore, in the present embodiment, when an external force having a force component in the detection direction of the first detection transmission mechanism exceeding a certain value is applied to the arm side member 32 of the arm portion 30, the slide rod 36A of the first detection transmission mechanism slides. Then, the state where the relative rotation of the inner ring member 43 and the outer ring member 42 around the fixed shaft 46 is prohibited is released. As a result, the arm portion 30 fixed to the outer ring member 42 is released from the restraint of the inner ring member 43 and becomes rotatable in the rotation direction around the fixed shaft 46. That is, the arm portion 30 fixed to the outer ring member 42 is rotatable in a direction to flow the force component of the external force applied to the arm side surface member 32, and this external force buffering function is exhibited.

Next, the configuration and operation of the buffer mechanism will be described in the case where an external force having a certain amount or more of the force component in the detection direction of the second detection transmission mechanism is applied to the arm side member 32 of the arm portion 30.
FIG. 6 is an exploded perspective view of the buffer mechanism 40 in the present embodiment.
In the present embodiment, the direction in which the inner ring member 43 and the outer ring member 42 can move relative to each other is the relative rotation direction around the fixed shaft 46 that can flow the force component in the detection direction of the first detection transmission mechanism, and the second detection transmission. Two of the relative rotational directions centered on an axis orthogonal to the fixed shaft 46 (which is also orthogonal to the arm longitudinal direction; hereinafter referred to as “second relative rotational axis C”) that can flow the force component in the detection direction of the mechanism. It is.

  In the present embodiment, in order to realize the relative rotation in the two directions with a single connecting portion, as shown in FIG. 6, the inner ring member 43 has a drum-shaped peripheral surface with respect to the fixed shaft 46. The inner ring member 43 is used, and the inner wall surface of the outer ring member 42 disposed so as to cover the inner ring member 43 is also spherical in accordance with the peripheral surface shape of the inner ring member 43.

  Further, in this embodiment, in order to realize the relative rotation in the two directions with a single connecting portion, the inner ring member 43 is detected when the detection of the external force is transmitted through the slide rod 36A of the first detection transmission mechanism. As shown in FIG. 6, the outer ring through which the tip end portion of the inner slider 44B penetrates so that the slide rod 36B and the inner slider 44B of the second detection transmission mechanism do not hinder the relative rotation of the outer ring member 42 around the fixed shaft 46. A slider insertion recess 42 b on the member 42 extends in the circumferential direction of the fixed shaft 46.

  Similarly, when the detection of the external force is transmitted via the slide rod 36B of the second detection transmission mechanism, the relative rotation around the second relative rotation axis C between the inner ring member 43 and the outer ring member 42 is caused by the first detection transmission mechanism. As shown in FIG. 6, a slider insertion recess 42a on the outer ring member 42 through which the tip of the inner slider 44A penetrates extends in the circumferential direction of the second relative rotation axis C so that the slide rod 36A and the inner slider 44A do not interfere. ing. Further, the fixed shaft 46 fixed to the inner ring member 43 passes through the through holes 42d provided in both end plates 42c of the outer ring member 42 in the axial direction of the fixed shaft 46, and as shown in FIG. 20 is fixed to the side plate 24 of the upper joint portion 22. Therefore, when the inner ring member 43 and the outer ring member 42 rotate relative to each other around the second relative rotation axis C, the through holes 42d of the both end plates 42c are made to be the second relative rotation axis so that the fixed shaft 46 does not hinder. It is long in the circumferential direction of C.

FIG. 7 is an exploded perspective view of the inner ring member 43 in the present embodiment.
The inner sliders 44A and 44B are attached to the inner ring main shaft member 43a via a compression spring (not shown). In the present embodiment, a plurality of ball bears 43 c are incorporated on the outer surface of the peripheral surface member 43 b of the inner ring member 43 so that the inner ring member 43 can smoothly rotate relative to the outer ring member 42.

  Four damper springs 43 d are provided inside the inner ring member 43. The damper shaft portion 43e of the damper spring 43d extends to the outside of the inner ring member 43 along the axial direction of the fixed shaft 46 through through holes provided in both end plates 43f of the inner ring member 43 in the axial direction of the fixed shaft 46. It protrudes. The damper spring 43d is rotated when the inner ring member 43 and the outer ring member 42 are rotatable relative to each other by the external force applied to the arm portion 30 and the outer ring member 42 is rotated relative to the inner ring member 43 by the external force. It plays a function of absorbing power. In particular, the damper spring 32d of the present embodiment supports a load from the outside with a bone spring and absorbs vibration with a viscoelastic body covering the spring, so that a high buffering function can be realized. The damper spring 43d reversely rotates the outer ring member 42 rotated relative to the inner ring member 43 when the external force applied to the arm part 30 is lost, and again, the damper mechanism 43 and the arm part 30 It functions to return the arm side member 32 to the normal state.

FIGS. 8A and 8B are explanatory diagrams for explaining the operation of the damper spring 43d when an external force having a force component in the detection direction of the first detection transmission mechanism that exceeds a certain level is applied to the arm portion 30. FIG. .
In the normal state shown in FIG. 8A, when an external force having a force component in the detection direction of the first detection transmission mechanism exceeds a certain level is applied to the arm portion 30, for example, as shown in FIG. Rotates relative to the inner ring member 43 around the fixed shaft 46 in the direction of the arrow in the figure. Protrusions 42e are provided on the inner wall surfaces of both end plates 42c of the outer ring member 42. When the outer ring member 42 rotates relative to the inner ring member 43 around the fixed shaft 46, the inclined surface of the protrusion 42e facing the leading side in the relative rotation direction comes into contact with the damper shaft portion 43e of the inner ring member 43. As the relative rotation of the outer ring member 42 with respect to the inner ring member 43 proceeds, the damper shaft 43e of the inner ring member 43 is pushed in along the inclined surface of the protrusion 42e of the outer ring member 42. As a result, the impact is absorbed by the action of the viscoelastic body of the damper spring 32d of the damper shaft portion 43e.

  Furthermore, the damper spring 32d exhibits a drag force that attempts to return the pushing according to the pushing amount of the damper shaft portion 43e. This drag force is a force for returning the relative rotation of the outer ring member 42 with respect to the inner ring member 43, so that a force for pushing back the external force applied to the arm portion 30 is exhibited. As a result, when the external force applied to the arm portion 30 disappears, the outer ring member 42 that rotates relative to the inner ring member 43 rotates in the reverse direction. When the inner slider 44A of the inner ring member 43 rotates reversely to a position facing the slider insertion recess 42a of the outer ring member 42, the inner slider 44A is inserted into the slider insertion recess 42a by the urging force of the compression spring 45A, and the buffer mechanism 40 The state returns to the normal state (power transmission state) in which the relative rotation of the inner ring member 43 and the outer ring member 42 around the fixed shaft 46 is prohibited. Further, when the inner slider 44A is inserted into the slider insertion recess 42a, the slide rod 36A of the arm unit 30 is also pushed back from the detection transmission position to the normal position. As a result, the slide member 34A slides, and in conjunction with this, the fixing member 33A is displaced in the arm side surface direction, and the arm side member 32 returns to the normal state before receiving external force (before displacement).

FIGS. 9A and 9B are explanatory diagrams for explaining the operation of the damper spring 43d when an external force having a force component in the detection direction of the second detection transmission mechanism that exceeds a certain level is applied to the arm portion 30. FIG. .
In the normal state shown in FIG. 9A, when an external force having a force component in the detection direction of the second detection transmission mechanism exceeds a certain level is applied to the arm portion 30, for example, as shown in FIG. Rotates relative to the inner ring member 43 around the second relative rotation axis C in the direction of the arrow in the figure. When the outer ring member 42 rotates relative to the inner ring member 43 about the second relative rotation axis C, the inclined surface of the protrusion 42e facing the leading side in the relative rotation direction contacts the damper shaft 43e of the inner ring member 43. . As the relative rotation of the outer ring member 42 with respect to the inner ring member 43 proceeds, the damper shaft 43e of the inner ring member 43 is pushed in along the inclined surface of the protrusion 42e of the outer ring member 42. As a result, the impact is absorbed by the action of the viscoelastic body of the damper spring 32d of the damper shaft portion 43e.

  Furthermore, the damper spring 32d exhibits a drag force that attempts to return the pushing according to the pushing amount of the damper shaft portion 43e. This drag force is a force for returning the relative rotation of the outer ring member 42 with respect to the inner ring member 43, so that a force for pushing back the external force applied to the arm portion 30 is exhibited. As a result, when the external force applied to the arm portion 30 disappears, the outer ring member 42 that rotates relative to the inner ring member 43 rotates in the reverse direction. When the inner slider 44B of the inner ring member 43 rotates backward to a position facing the slider insertion recess 42b of the outer ring member 42, the inner slider 44B is inserted into the slider insertion recess 42b by the urging force of the compression spring 45B, and the buffer mechanism 40 The state returns to the normal state in which the relative rotation around the second relative rotation axis C between the inner ring member 43 and the outer ring member 42 is prohibited. Further, by inserting the inner slider 44B into the slider insertion recess 42b, the slide rod 36B of the arm unit 30 is also pushed back from the detection transmission position to the normal position. As a result, the slide member 34B slides, and in conjunction with this, the fixing member 33B is displaced in the arm side surface direction, and the arm side member 32 returns to the normal state before receiving external force (before displacement).

[Modification]
Next, a modification of the robot arm in the embodiment will be described.
The robot arm in this modification employs a fluid sealing member that has a flexibility that can be deformed by receiving an external force as an external force detection transmission mechanism. Moreover, in this modification, the structure of the buffer mechanism is also different from that of the above embodiment. Specifically, in the above-described embodiment, the outer ring member 42 and the inner ring member 43 are moved relative to the arm unit 30 by relative movement in two directions, that is, relative rotation about the fixed shaft 46 and relative rotation about the second relative rotation axis C. An external force having a force component of a certain level or more in two buffering directions of the detection direction of the first detection transmission mechanism and the detection direction of the second detection transmission mechanism can be buffered. On the other hand, there is only one buffering direction in this modification. In the following description, description of the same configuration and operation as in the above embodiment will be omitted.

FIG. 10 is a partially enlarged view of the joint mechanism 120 and the arm unit 130 in the robot arm of this modification.
The arm portion 130 of the robot arm includes a base portion 131 that extends in the longitudinal direction of the arm, and an arm side surface member that is configured by an air bag (fluid sealing member) 132 provided so as to cover the peripheral surface of the base portion 131. ing. As in the case of the above-described embodiment, an object handling unit or the like is appropriately attached to the end of the base 131 on the arm distal end side according to the use of the robot arm. On the other hand, the end (joint mechanism side end) of the base 131 opposite to the arm tip side end is fixed to the arm support member 124 of the joint mechanism 120.

FIGS. 11A and 11B are explanatory views showing the configuration and operation of the external force detection transmission mechanism in this modification.
The external force detection and transmission mechanism mounted on the arm unit 130 is provided so that an air bag (fluid sealing member) 132 having flexibility that can be deformed by receiving an external force covers the peripheral surface of the base 131. A fixing plate 133 is provided at the arm tip side end of the base 131 so that the air bag 132 does not move along the base 131 to the arm tip side. A movable plate 134 that is slidable relative to the base 131 is provided at the joint mechanism side end of the base 131. A slide rack 136 as a detection transmission member that slides in conjunction with the movement of the movable plate 134 abuts on the outer surface side of the movable plate 134.

  In the arm part 130 in the normal state shown in FIG. 11A, the air bag 132 of the moving arm part 130 collides with an obstacle or the like, or the air bag 132 of the arm part 130 that is moving or not moving. Obstacles may collide. In such a case, when an external force having a force component in the arm side surface direction exceeds a certain level is applied to the air bag 132 as shown in FIG. 11B, the portion of the air bag 132 that receives the external force is compressed and deformed. Due to this compression deformation, an instantaneous impact when an obstacle or the like collides with the air bag 132 is alleviated.

  Further, the portion receiving the external force is deformed so that the air in the air bag 132 moves due to compression deformation, and the air bag 132 extends in the arm longitudinal direction. As a result, as shown in FIG. 11B, the movable plate 134 provided at the joint mechanism side end of the air bladder 132 slides relative to the base 131. Then, the slide rack 136 is pushed by the sliding movable plate 134 and slides downward from the normal position shown in FIG. 11A toward the joint mechanism 120 in FIG. 11, and shown in FIG. 11B. As shown in FIG.

  In this modified example, even when an external force having a certain force component from the arm side surface direction is applied to the arm unit 130 from any direction in the arm circumferential direction, this can be detected and transmitted to the joint mechanism 120.

FIG. 12 is a perspective view showing the configuration of the joint mechanism 120 in the present modification.
The joint mechanism 120 of this modification realizes one degree of freedom by one joint part having one degree of freedom. The joint mechanism 120 includes a fixed frame 121 that is appropriately attached to a structure according to the use of the robot arm, such as attached to a carriage or attached to another joint mechanism. The fixed frame 121 rotatably supports the rotation shaft 123 of the arm support member 124. A drive input pulley 125 is fixed on the rotating shaft 123, and a timing belt (not shown) wound around a pulley provided on a motor shaft (not shown) is wound around the drive input pulley 125. It is done. The rotation shaft 123 of the arm support member 124 is attached to an input shaft of a speed reduction mechanism 126 such as a harmonic drive (registered trademark), and a drive gear 127 as a connected portion is connected to the output shaft of the speed reduction mechanism 126. Is attached. Therefore, when the drive motor is driven, the rotation shaft 123 of the arm support member 124 is rotated by the rotational driving force input to the drive input pulley 125 via the timing belt, and the drive gear 127 is rotated via the speed reduction mechanism 126. Rotate.

  In the normal state in which the slide rack 136 is located at the normal position shown in FIG. 11A, a rack portion 136a as a connecting portion provided at the lower end of the slide rack 136 in the drawing meshes with the drive gear 127. It is configured as follows. The relative movement of the slide rack 136 with respect to the rotation direction of the drive gear 127 is restricted with respect to the arm support member 124. Therefore, when the drive gear 127 rotates, the rack portion 136a moves in a direction of circling around the axis of the drive gear 127 along with this rotation. As a result, the slide rack 136 rotates about the rotation shaft 123 of the arm support member 124, and the arm support member 124 rotates about the rotation shaft 123 as the slide rack 136 rotates. Therefore, in the present modification, the arm portion 130 attached to the arm support member 124 can be rotated about the rotation shaft 123 by rotating the drive motor.

FIGS. 13A and 13B are explanatory diagrams for explaining the configuration and operation related to the buffer function in the joint mechanism 120 of this modification.
In the normal state shown in FIG. 13A, when an external force having a force component in the arm side surface direction and in the direction of the degree of freedom of the joint mechanism 120 is applied to the air bag 132 of the arm portion 130, the arm bag 130 is in the normal position. The slide rack 136 slides to the detection transmission position in conjunction with the movement of the movable plate 134. The slide rack 136 is attached to the arm support member 124 so as to be slidable along the longitudinal direction of the arm. When the slide rack 136 is slid, the rack portion 136a also moves along the arm longitudinal direction. Moves to the other side. As a result, as shown in FIG. 13B, the meshing state (power transmission state) in which the rack portion 136a and the drive gear 127 are meshed is released, and the power transmission is released. Therefore, the rack portion 136 a can freely rotate relative to the drive gear 127 around the rotation shaft 123.

  As described above, in this modified example, when an external force having a certain force component in the arm side surface direction and the degree of freedom of the joint mechanism 120 is applied to the air bag 132 of the arm unit 130, the slide rack 136 slides. Then, the power transmission state in which the relative rotation of the rack portion 136a and the drive gear 127 around the rotation shaft 123 is prohibited is released. As a result, the arm portion 130 fixed to the arm support member 124, whose relative rotation around the rotation shaft 123 is restricted with respect to the slide rack 136, leaves the restraint of the drive gear 127 and is centered on the rotation shaft 123. It will be in the state which can rotate freely in the direction of rotation. That is, the arm part 130 is rotatable in a direction to flow the force component of the external force applied to the air bag 132, and the buffering function of the external force is exhibited.

  Further, in this modified example, even when an external force having a force component in the arm side surface direction and perpendicular to the direction of freedom of the joint mechanism 120 is applied to the air bag 132 of the arm unit 130, The slide rack 136 located at the normal position slides to the detection transmission position. Therefore, even in this case, the arm unit 130 is free from the restraint of the drive gear 127 and can rotate in the rotation direction around the rotation shaft 123. However, in this case, the external force applied to the air bag 132 is not rotatable in the direction in which the force component is received, and thus the external force buffering function is not exhibited. However, since an abnormal situation occurs in which an obstacle collides with the arm portion 130 from the side of the arm, it is impossible to move the arm portion 130 by the drive motor by making the arm portion 130 rotatable. Useful in dealing with abnormal situations.

  In this modification, when the slide rack 136 leaves the restraint of the drive gear 127 and becomes rotatable about the rotation shaft 123, the drag that resists the rotational force of the slide rack 136 is exhibited. An elastic member such as the damper spring 43d in the embodiment is provided. Therefore, the slide rack 136 and the drive gear 127 can be rotated relative to each other by the external force applied to the arm unit 130. When the slide rack 136 rotates relative to the drive gear 127 by the external force, the rotational force is applied to this. It can be absorbed by the elastic member.

  The slide rack 136 is always applied with a biasing force from the detection transmission position to the normal position by a biasing means (not shown). Therefore, when the external force applied to the arm portion 130 is lost, the slide rack 136 is returned from the detection transmission position to the normal position by the biasing force. As a result, the rack portion 136a and the drive gear 127 return to the meshed state again. Further, the sliding movement of the movable plate 134 is also returned, whereby the air bag 132 extending in the arm longitudinal direction returns to the normal shape.

  In this modified example, as described above, an external force having a force component in a direction perpendicular to the direction of the degree of freedom of the joint mechanism 120 is applied to the air bag 132 of the arm unit 130 as described above. In some cases, the buffering function of the external force is not exhibited, but the buffering function of the external force can be exhibited. This configuration can be realized, for example, as follows.

  In the robot arm of this modification, the slide rack 136 is configured to be movable relative to the arm support member 124 along the axial direction of the rotation shaft 123. In a normal state where the rack portion 136a of the slide rack 136 is engaged with the drive gear 127, the relative movement of the slide rack 136 in the axial direction of the slide rack 136 with respect to the arm support member 124 is prohibited. When an external force having a certain amount or more of a force component in the arm side surface direction orthogonal to the direction of freedom of the joint mechanism 120 is applied to the air bag 132 of the arm unit 130, the slide rack 136 located at the normal position is used. Slides to the detection transmission position. As a result, when the meshing state of the rack portion 136a of the slide rack 136 and the drive gear 127 is released, the power transmission state in which relative movement of the slide rack 136 relative to the arm support member 124 in the axial direction is prohibited. To be released. As a result, the slide rack 136 is movable relative to the arm support member 124 along the axial direction of the rotation shaft 123. That is, the arm portion 130 fixed to the arm support member 124 is rotatable in a direction to receive the force component of the external force applied to the air bag 132, and the external force buffering function is exhibited.

Further, in this modification, when an external force having a certain force component from the arm side surface direction is applied to the arm unit 130, it is not configured to detect the difference in the direction of the external force. It is also possible to have a configuration that can. For example, a plurality of air bags may be disposed around the base 31 and a detection transmission member that can move independently for each air bag may be provided.
Further, the sealed fluid may not be air but may be other gas or liquid.

  Moreover, as an external force detection transmission mechanism using the fluid sealing member which has the softness | flexibility which can deform | transform by receiving external force, a structure as shown in FIG. 14 is also employable, for example. In this configuration, two air bags 132A and 132B are provided in series along the longitudinal direction of the arm, and the insides of these air bags 132A and 132B are connected by a connecting pipe 139. In this configuration, both ends in the arm longitudinal direction of the first air bag 132A apart from the joint mechanism 120 having a buffer function are pressed by the fixed plate 133A. Therefore, when an obstacle collides with the first air bag 132A, the first air bag 132A is compressed and deformed, so that the air in the first air bag 132A flows into the second air bag 132B. As a result, the second air bag 132B is deformed so as to extend in the longitudinal direction of the arm, and the movable plate 134 provided at the joint mechanism side end (the right end in FIG. 14) of the second air bag 132B is formed on the base 131. Move relative to the slide. Then, the slide rack 136 is slid by being pushed by the movable plate 134 that slides. Even when an obstacle collides with the second air bag 132B, the second air bag 132B is deformed so as to extend in the longitudinal direction of the arm, and the slide rack 136 slides. According to this configuration, even when an obstacle collides with either the first air bag 132A or the second air bag 132B arranged in series in the arm longitudinal direction, the buffer function of the joint mechanism 120 can be exhibited.

DESCRIPTION OF SYMBOLS 10 Base 20 Joint mechanism 21 Lower joint part 22 Upper joint part 23 Turning drive motor 24 Side plate 25 Up / down turning drive motor 30 Arm part 31 Base part 32 Side member 33A, 33B Fixing member 34A, 34B Slide member 35A, 35B Connecting rod 36A, 36B Slide rod 40 Buffer mechanism 41 Fixed member 42 Outer ring member 43 Inner ring members 44A, 44B Inner sliders 45A, 45B Compression spring 46 Fixed shaft 50 Hand 120 Joint mechanism 121 Fixed frame 123 Rotating shaft 124 Arm support member 127 Drive gear 130 Arm portion 131 Base portion 132 Air bag 133 Fixed plate 134 Movable plate 136 Slide rack 136a Rack portion

JP 2006-167820 A JP 2007-301704 A

Claims (7)

A driving source;
An arm,
An object handling unit connected to one longitudinal end of the arm unit;
A joint mechanism for moving the arm portion in a predetermined degree of freedom direction by a driving force from the driving source;
The linking power connected to the arm portion and the connected portion connected to the connecting portion are connected in a relatively movable state and the relative movement between the connecting portion and the connected portion is prohibited. A connection release mechanism that can be switched in a non-powered state from a transmission state to a power transmission release state that releases the prohibition of the relative movement;
A robot arm that moves the arm portion in the direction of the predetermined degree of freedom by a driving force from the driving source in the power transmission state;
The connection release mechanism connects the connecting portion and the connected portion so as to be relatively movable in two or more relative movement directions,
In any of the two or more relative movement directions, when an external force having a force component in that direction is applied to the arm unit, the external force is used to operate in a non-powered state, and the external force is applied to the object handling unit. Has an external force detection transmission mechanism with a detection transmission member that does not operate even if added ,
The connection release mechanism cancels the power transmission in a power transmission state in which relative movement in the relative movement direction corresponding to the force component of the external force applied to the arm portion is prohibited in conjunction with the operation of the detection transmission member. A robot arm characterized by switching to a state. The robot arm according to claim 1, wherein
The external force detection / transmission mechanism includes two or more detection transmission members that differ for each of the two or more relative movement directions, and a detection transmission member for a relative movement direction corresponding to the force component of the external force applied to the arm portion. Is configured to operate only,
The connection release mechanism switches the power transmission state in which relative movement only in the relative movement direction corresponding to the activated detection transmission member is prohibited to the power transmission release state in conjunction with the operation of each detection transmission member. Robot arm. The robot arm according to claim 1 or 2,
The robot release arm is a robot arm characterized in that the connection release mechanism is a single connection part and connects the connection part and the connected part so as to be relatively movable in the two or more relative movement directions. The robot arm according to any one of claims 1 to 3,
The detection transmission member of the external force detection transmission mechanism is configured to be movable along the longitudinal direction of the arm portion,
The arm portion includes an arm side surface member that is displaceable in a direction to flow the force component by receiving an external force having a force component in a direction perpendicular to the longitudinal direction of the arm portion at a certain level,
The robot arm according to claim 1, wherein the external force detection and transmission mechanism includes a link mechanism that moves the detection and transmission member along the longitudinal direction of the arm portion in conjunction with the displacement of the arm side surface member. The robot arm according to any one of claims 1 to 3,
The arm portion includes an arm side surface member configured by a fluid sealing member having flexibility that can be deformed by receiving an external force having a force component in a direction orthogonal to the longitudinal direction of the arm portion at a certain level or more. ,
The robot arm according to claim 1, wherein the detection transmission member of the external force detection transmission mechanism is configured to operate in conjunction with movement of the sealed fluid due to deformation of the fluid sealing member. A driving source, an arm unit, an object handling unit connected to one longitudinal end of the arm unit, a joint mechanism for moving the arm unit in a predetermined degree of freedom by a driving force from the driving source, and Power transmission in which the connecting portion connected to the arm portion and the connected portion connected to the connecting portion are connected in a relatively movable state, and relative movement between the connecting portion and the connected portion is prohibited. A connection release mechanism that can be switched from a state to a power transmission release state that releases the prohibition of relative movement in a non-powered state, and in the power transmission state, the arm portion is driven by the driving force from the drive source. An external force detection and transmission device for a robot arm that detects an external force applied to the arm portion and transmits the external force to the connection release mechanism in a robot arm that moves in a direction of freedom,
In any of the two or more directions, when an external force having a certain force component in that direction is applied to the arm portion, the external force is used to operate in a non-powered state, and the external force is applied to the object handling portion. An external force detection and transmission device for a robot arm, characterized by having a detection and transmission member that does not operate . A driving source, an arm part, an object handling part connected to one longitudinal end of the arm part, a joint mechanism for moving the arm part in a predetermined degree of freedom by a driving force from the driving source, and 2 In any of the above directions, when an external force having a force component in that direction is applied to the arm portion, the external force is used to operate in a non-powered state, and an external force is applied to the object handling portion. In a shock absorber for a robot arm used for a robot arm having an external force detection transmission mechanism including a detection transmission member that does not operate ,
A connecting portion connected to the arm portion and a connected portion connected to the connecting portion are connected in a state of being relatively movable in two or more relative movement directions for receiving the force components in the two or more directions, and A connection release mechanism capable of switching in a non-powered state from a power transmission state in which relative movement between the connection portion and the connected portion is prohibited to a power transmission release state in which the prohibition of the relative movement is canceled;
In conjunction with the operation of the detection transmission member, the power transmission state is switched from the power transmission state in which the relative movement in the relative movement direction corresponding to the force component possessed by the external force applied to the arm portion is prohibited to the power transmission release state. A shock absorber for the robot arm.

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