JP2007223038A - Joint structure body and robot arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure body in a joint mechanism transmitting the driving force completely without any influence of motion of a joint, and also to provide a robot arm including the joint structure body. <P>SOLUTION: A second structure 2 is rotated around a first rotary joint by the drive of a first driving device 4 to thereby generate rotation around the first rotary joint of a movable rotary pulley 10 to the first and second rotary guide pulleys 30, 31, and a wire 7 is guided by the reverse rotation to the rotating direction around the movable rotary pulley to cancel increase and decrease in an amount applied to the first and second rotary guide pulley peripheral parts, whereby the distance between the first and second rotary guide pulleys and the movable rotary pulley is made invariable. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a joint structure applicable to a joint mechanism of a mechanical device such as a robot arm, and a robot arm including the joint structure.

  Conventionally, a multi-joint robot arm usually has a structure in which an actuator for driving the joint is arranged at or near the joint. However, in such a structure, a portion close to the hand, such as a wrist of a humanoid arm, is heavy. Since a motor or the like is disposed, the inertia of the hand increases, which impedes the improvement of the position control performance of the hand, or gives a large impact at the time of a collision, which must be considered in terms of safety.

  In order to solve such problems, a wire-driven robot arm has been developed in which an actuator is disposed apart from a joint to be driven and is located near the base, and a driving force is transmitted by a wire. The wire-driven robot arm has excellent features such as high-speed driving because the hand can be made lightweight.

  However, in a wire-driven robot arm, in order to reduce the inertia on the hand side, an actuator is arranged on the body, which is the base to which the arm is attached, and the wire is routed when driving the wrist. When the distance is increased, it is necessary to dispose the wire across the joint on the way, such as the elbow of a humanoid arm. In this case, when the motion of the joint in the middle is driven, the path length of the wire changes, and the problem arises that the motion of the joint of the tip part such as the wrist driven by the wire is affected. .

  With respect to this problem, Patent Document 1 discloses a configuration having a pair of guide pulleys arranged so as to deviate from the rotation center of the joint. Patent Document 2 discloses a configuration having a wire guide pulley whose center of rotation rotates with the movement of a joint.

Japanese Patent No. 3290709 Japanese Patent Publication No. 6-77914

  However, in the configuration of Patent Document 1, the change in the path length of the wire due to the motion of the joint cannot be completely removed, and the change in the path length increases as the rotation angle of the joint in the middle increases. Further, in the configuration of Patent Document 2, when a rotational movement of the wire guide pulley occurs with the rotation of the joint, in a state where the joint is bent, before the wire is bent in the direction of the distal arm member, the wire guide pulley Since the path of the wire is bent in the direction opposite to that of the distal arm member, the path of the wire cannot be made completely constant regardless of the movement of the joint.

  An object of the present invention is to solve the above-described problems of the conventional joint mechanism, and provide a joint structure capable of transmitting a driving force without being completely affected by the movement of the joint, and a robot arm including the joint structure There is to do.

  In order to achieve the above object, the present invention is configured as follows.

According to the first aspect of the present invention, the first structure,
A second structure;
A first rotary joint that rotatably connects the first structure and the second structure;
A first rotation guide with a guide groove disposed on the first structure or the second structure so as to be coaxial with the rotation axis of the first rotation joint and rotatable about the rotation axis and rotatable relative to each other. A pulley and a second rotating guide pulley with a guide groove;
A movable rotating guide pulley with a guide groove disposed so as to be relatively movable with respect to the second structure;
A mechanism for changing a distance between the first or second rotation guide pulley and the movable rotation guide pulley;
An auxiliary rotation guide pulley with a guide groove rotatably disposed in the first structure,
From one end side to the other end side, the guide groove of the first rotation guide pulley, the guide groove of the movable rotation guide pulley, the guide groove of the second rotation guide pulley, and the guide of the auxiliary rotation guide pulley A wire spanned in the order of the grooves,
A first drive device having one end fixed to the first structure and the other end connected to the second structure, the second drive capable of rotating the second structure around the first rotary joint;
One end is fixed to the first structure, and both the one end and the other end of the wire are fixed to the other end, and the wire is guided through the wire while being guided by the rotation of the auxiliary rotation guide pulley. And a second driving device capable of moving the movable rotation guide pulley relative to the second structure by swinging the lever at the one end.
Without driving the second driving device, the first driving device drives the second structure to rotate about the rotation axis of the first rotary joint, and the first and second rotation guide pulleys. Generating a relative rotational motion of the movable rotating pulley around the rotational axis of the first rotational joint, and rotating in a direction opposite to the rotational direction of the rotational motion around the rotational axis of the movable rotational pulley. As a result of the wire being guided by the rotational movement, the increase and decrease of the amount of the wire applied to the circumferential portion of the guide groove of each of the first and second rotation guide pulleys is offset, and the first and second rotation guides Provided is a robot arm in which the distance between each pulley and the movable rotating pulley is not changed.

  According to the present invention, the driving force of the second driving device (for example, a linear actuator) disposed in the first structure is passed over the rotating joint without being affected by the rotational motion at the rotating joint. It is possible to transmit to the previous part (for example, hand).

  Therefore, a second drive device such as an actuator that drives the movement of the wrist of the robot arm can be disposed on the base side of the robot arm, the inertia on the tip side of the robot arm is reduced, and position control and force can be reduced. Control performance related to control is improved, and it is possible to operate at high speed. Further, since the inertia is small, the kinetic energy is also reduced, and the safety at the time of collision is improved.

  Before continuing the description of the present invention, the same parts are denoted by the same reference numerals in the accompanying drawings.

  Before describing embodiments of the present invention in detail based on the drawings, various aspects of the present invention will be described below.

  According to the first aspect of the present invention, the first structure, the second structure, the rotary joint connecting the first structure and the second structure, the same axis as the rotation axis of the rotary joint, and the above A rotation guide pulley disposed so as to be rotatable around a rotation axis, a fixed guide disposed in the first structure and having an arc portion, and movable relative to the second structure. The movable rotation guide pulley disposed, the rotation guide pulley, the movable rotation guide pulley, the wire spanned in the order of the fixed guide, the first structure, and the rotation guide pulley with respect to the rotation guide pulley A first drive device capable of rotating the second structure around the rotary joint without changing the distance of the movable rotation guide pulley, the first structure provided in the first structure and capable of driving the wire; and , Above And a second driving device that moves the movable rotation guide pulley so as to change the distance to the rotation guide pulley, and changes the distance of the movable rotation guide pulley relative to the rotation guide pulley. Instead, a joint structure is provided in which the second structure is driven to rotate around the rotary joint by driving the first drive device.

  According to a second aspect of the present invention, there is provided the joint structure according to the first aspect, wherein the fixed guide is configured as a part of a member fixed to the first structure.

  According to a third aspect of the present invention, the movable rotation guide pulley includes a first movable rotation guide pulley in which a guide groove is located in the same plane as a plane including the guide groove of the rotation guide pulley, and a guide of the fixed guide. The joint structure according to the first aspect is characterized in that the second movable rotating guide pulley in which the guide groove is located in the same plane as the plane including the groove is integrally configured.

  According to the fourth aspect of the present invention, the movable rotation guide pulley includes a first guide groove located in the same plane as the plane including the guide groove of the rotation guide pulley, and a plane including the guide groove of the fixed guide. The joint structure according to the first aspect is provided, having a second guide groove located in the same plane.

  According to the fifth aspect of the present invention, the first structure, the second structure, the rotary joint connecting the first structure and the second structure, the same axis as the rotation axis of the rotary joint, and the above A first rotation guide pulley and a second rotation guide pulley which are respectively arranged in the first structure or the second structure and are rotatable relative to each other so as to be rotatable around a rotation axis, and the second structure A movable rotation guide pulley disposed so as to be relatively movable, an auxiliary rotation guide pulley rotatably disposed on the first structure, the first rotation guide pulley, the movable rotation guide pulley, The second rotating guide pulley and the auxiliary rotating guide pulley are spanned in this order and both ends are fixed to the second driving device, and the first structure includes the first and the second rotating guide pulleys. Second rotating guide pooh Without changing the distance of the movable rotation guide pulley relative to the first drive unit, the first drive device capable of rotating the second structure around the rotary joint, and the first structure can drive the wire. And a second driving device that moves the movable rotation guide pulley so as to change the distance to the first and second rotation guide pulleys by driving the wire. Provided is a joint structure characterized in that the second structure is driven to rotate around the rotary joint by driving the first drive device without changing the distance of the movable rotary guide pulley to the two-rotation guide pulley. To do.

  According to a sixth aspect of the present invention, the first structure, the second structure, the rotary joint connecting the first structure and the second structure, the same axis as the rotation axis of the rotary joint, and the above A third rotation guide pulley disposed so as to be rotatable about a rotation axis, a fourth rotation guide pulley disposed rotatably on the second structure, and relatively movable with respect to the second structure The movable rotation guide pulley arranged in such a manner and the first structure body, the second structure body can be connected to the rotation joint without changing the distance of the movable rotation guide pulley relative to the rotation guide pulley. A first driving device capable of rotating around the first driving device, the first structure provided in the first structure body, capable of driving the wire, and driving the wire to change the distance to the rotating guide pulley. Movable rotating guy A second drive device for moving the pulley, the third rotation guide pulley, the movable rotation guide pulley, and the fourth rotation guide pulley are spanned in this order, and one end is fixed to the second drive device and the other end Including a wire fixed to the fourth rotation guide pulley, one end of which is rotatably supported by the first structure, and one end of which is the other end of the first parallel link. And a second parallel link whose other end is fixed to the fourth rotation guide pulley, and the one end of the first parallel link is supported with respect to the first structure. A portion connected to the other end portion of the first parallel link and the one end portion of the second parallel link, the other end portion of the second parallel link, and the fourth rotation guide pulley. Fixed part And a portion of the fourth rotating guide pulley that is rotatably disposed on the second structure body to form a four-joint parallel link structure, and the movable rotation with respect to the third rotating guide pulley There is provided a joint structure characterized in that the second structure is driven to rotate around the rotary joint by driving the first drive device without changing the distance of the guide pulley.

  According to a seventh aspect of the present invention, a first structure, a second structure, a rotation guide pulley disposed so as to be coaxial with the rotation axis of the rotary joint and rotatable about the rotation axis; A movable rotation guide pulley disposed so as to be relatively movable with respect to the second structure, and the first structure provided in the first structure without changing a distance of the movable rotation guide pulley with respect to the rotation guide pulley. A first drive device capable of rotating the second structure around the rotary joint; and the first structure provided in the first structure can drive the wire, and the wire is driven to drive the rotation. The second drive device that moves the movable rotating guide pulley so as to change the distance to the guide pulley, the rotating guide pulley, and the movable rotating guide pulley are spanned in this order, and one end is A first parallel link fixed to the second driving device and having the other end fixed to the movable rotating guide pulley and having one end rotatably supported by the first structure, and one end A second parallel link that is rotatably and slidably connected to the other end portion of the first parallel link and the other end portion is fixed to the movable rotation guide pulley, and the one end of the first parallel link A portion supported by the first structure, a portion where the other end of the first parallel link and the one end of the second parallel link are connected, and a portion of the second parallel link A four-joint parallel link structure having a fixed portion between the other end and the movable rotating guide pulley and a portion rotatably disposed on the second structure of the rotating guide pulley as four fulcrums. Configure the above rotating guide pulley Without changing the distance of the movable rotating guide pulley for, providing joint structure, characterized in that rotationally drives the second structure to the rotary joint about by the driving of the first driving device.

According to an eighth aspect of the present invention, the joint structure according to any one of the first to seventh aspects;
A hand disposed at a tip of the second structure opposite to the rotary joint side; a hand drive wire for connecting the movable rotary guide pulley and the hand; and the movable rotary guide pulley comprising: There is provided a robot arm characterized in that the hand is rotated with respect to the second structure by the hand driving wire by being relatively movable with respect to the second structure.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

(First embodiment)
1A and 1B are general views showing a joint structure according to a first embodiment of the present invention. In FIGS. 1A and 1B, the structure is shown by way of example in which the joint structure according to the first embodiment is applied to the robot arm 100.

  1A and 1B, reference numeral 1 denotes a rod-shaped first structure, which forms the upper arm of the robot arm 100. Reference numeral 2 denotes a rod-shaped second structure that forms the forearm of the robot arm 100. The first structure 1 and the second structure 2 are connected by a first rotary joint 3, and the first structure 1 and the second structure 2 are relatively centered on the joint axis 3 a of the first rotary joint 3. Forward and reverse rotation is possible. As an example, as shown in FIG. 1B, the first rotary joint side end of the second structure 2 is formed in a bifurcated branch 2a, and the lower end of the first structure 1 is formed in the branch 2a. The portion is sandwiched so as to be relatively rotatable with respect to the joint shaft 3a.

  Reference numerals 4-1 and 4-2 denote two first linear actuators, such as pneumatic artificial muscles, which can constitute a first linear actuator as an example of the first driving device. The upper end portions of the two first linear actuators 4-1 and 4-2 are fixed to the support plate 1 a fixed to the upper end portion. The lower ends of the two first linear actuators 4-1 and 4-2 are respectively connected to the rotating ends of the rotary joints 5-1 and 5-2 whose base ends are fixed to the second structure 2. Two first linear actuators 4-1 and 4-2 are connected to the first structure body 1 and the second structure body 2 by being rotatably connected, and the first structure body 1 and the second structure body The forward / reverse rotational motion of the second first rotational joint 3 is driven. That is, the base end portions of the rod-shaped rotary joints 5-1 and 5-2 are fixed to the second structure 2, and the first linear motion actuator 4-1 is attached to the front ends of the joints 5-1 and 5-2. The lower end of 4-2 is rotatably connected. As a result of the rotational joint 5-1 and the joint 5-2 being arranged symmetrically with respect to the rotational axis 3a of the first rotational joint 3, the lower end of the first linear actuator 4-1 rises and the first When the lower end portion of the linear actuator 4-2 is lowered, the second structure 2 rotates clockwise around the rotation axis 3a of the first rotary joint 3. On the other hand, when the lower end portion of the first linear motion actuator 4-1 is lowered and the lower end portion of the first linear motion actuator 4-2 is raised, the second structure 2 is rotated by the rotation shaft 3 a of the first rotary joint 3. Rotate counterclockwise.

  6-1, 6-2 (although they are overlapped in FIG. 1A, the second linear actuator on the front side is 6-1 and the second linear actuator on the back side is 6-2). For example, two second linear actuators such as pneumatic artificial muscles, motors, cylinders, etc., which can constitute a second linear actuator as an example of the second driving device, are two second linear actuators 6-1. 6-2, the arm bending wires 7-1 and 7-2 having their respective ends fixed to the lower ends of the second linear actuators 6-1 and 6-2 are pulled and driven.

  As shown in FIG. 3, the pneumatic artificial muscles constituting the linear motion actuators 4-1, 4-2, 6-1, and 6-2 are formed on the outer surface of the tubular elastic body 15 made of a rubber material. A restraining member 16 composed of a fiber cord is provided, and both ends of the tubular elastic body 15 are hermetically sealed with a sealing member 17. By supplying a compressive fluid such as air into the tubular elastic body 15 through a fluid injecting member 18 provided on the sealing member 17 at one end of the tubular elastic body 15, the internal pressure of the tubular elastic body 15 is increased. , The tubular elastic body 15 tends to expand mainly in the radial direction, but is converted into a movement in the central axis direction of the tubular elastic body 15 by the action of the restraining member 16, and the entire length of the tubular elastic body 15 contracts. . Conversely, when the pressure in the inner space of the tubular elastic body 15 is lowered by discharging a compressive fluid such as air from the tubular elastic body 15 through the fluid injecting member 18, the tubular elastic body 15 contracts mainly in the radial direction. However, due to the action of the restraining member 16, the tubular elastic body 15 is converted into movement in the central axis direction, and the entire length of the tubular elastic body 15 is extended. Since this pneumatic artificial muscle is mainly composed of an elastic body, it has a feature that it is a flexible, safe and lightweight actuator.

  Reference numerals 8-1 and 8-2 denote rotation guide pulleys with guide grooves 8a, which are coaxial with the rotation shaft 3a of the first rotation joint 3 at respective positions facing each other with the second structure 2 interposed therebetween, and the rotation shaft 3a. On the other hand, it is disposed in the second structure 2 so as to be rotatable with a bearing or the like interposed therebetween, and can rotate freely around the rotation shaft 3 a with respect to the second structure 2. In FIG. 1A, the rotation guide pulley 8-2 on the back side is not shown because it is a shadow of the rotation guide pulley 8-1 on the near side, but is shown in FIG. 1B.

  Reference numerals 9-1 and 9-2 denote fixed guide pulleys with guide grooves 9a, which are examples of fixed guides, and have the same radius as the rotation guide pulleys 8-1 and 8-2 and face each other with the second structure 2 in between. In this position, it is arranged on the outer side of the rotation guide pulleys 8-1 and 8-2 so as to be coaxial with the rotation shaft 3 a of the first rotation joint 3. The fixed guide pulleys 9-1 and 9-2 are fixed to the first structure 1 by the rotation shaft 3a, and the relative rotation between the fixed guide pulleys 9-1 and 9-2 and the first structure 1 is performed. There is no movement. In FIG. 1A, the fixed guide pulley 9-2 on the back side is not shown because it is a shadow of the fixed guide pulley 9-1 on the near side, but is shown in FIG. 1B. The rotating shaft 3a is fixed to the second structure 2 respectively.

  10-1 and 10-2 are movable rotating pulleys with a guide groove 10a disposed in the middle portion of the second structure 2, and are disposed at the upper end of the lever 11-1 and the lower end 11-2 of the lever, The rotary shafts 10-1a and 10-2a can be rotated. The lower end portion of the lever 11-1 and the upper end portion of the lever 11-2 are disposed at respective positions facing each other across the second structure 2, and the lower end portion of the lever 11-1 and the lever 11-2 The upper end portion can swing around the fulcrums 11-1a and 11-2a.

  Reference numeral 12 denotes a hand for gripping an article or the like, which is connected to the second structure 2 by the second rotary joint 13 and can swing relative to the second structure 2 around the joint axis 13a. It is.

  Reference numerals 14-1 and 14-2 denote hand drive wires, and their ends are fixed to the rotary shafts 10-1a and 10-2a of the movable rotary pulleys 10-1 and 10-2, respectively. The portion is fixed at a symmetrical position about the joint axis 13 a of the hand 12.

  Next, the path of the arm bending wire 7-1 with respect to the rotation guide pulley 8-1, the fixed guide pulley 9-1 and the movable rotation pulley 10-1 will be described with reference to FIG. In addition, although it is hung so that a wire may be accommodated in each guide groove with respect to each pulley (refer FIG. 1B), description is abbreviate | omitted about the guide groove in the following description.

  The arm bending wire 7-1 having one end fixed to the lower end of the first linear actuator 6-1 is guided to the rotation guide pulley 8-1, and the path is bent by the rotation guide pulley 8-1 (arrow). (Refer to (1)), leading from below the joint shaft 3a of the first rotary joint 3 to the movable rotary pulley 10-1 on the paper surface of FIG. 2, and downwardly on the paper surface of FIG. 2 of the movable rotary pulley 10-1. (See arrow (2)). After that, the arm bending wire 7-1 is bent by the movable rotating pulley 10-1 so as to change its direction (see arrow (3)), and is fixed from the upper side on the paper surface of FIG. 2 of the movable rotating pulley 10-1. The guide pulley 9-1 is guided upward on the paper surface of FIG. 2 (see arrow (4)). Thereafter, after the arm bending wire 7-1 runs along the outer periphery of the fixed guide pulley 9-1 (see arrow (5)), the end portion of the arm bending wire 7-1 is fixed by the wire fixing pin 7p. It is fixed to -1.

  The path of the arm bending wire 7-2 with respect to the rotation guide pulley 8-2, the fixed guide pulley 9-2, and the movable rotation pulley 10-2 is the same as the path of the arm bending wire 7-1. Description is omitted.

  FIG. 4 is a diagram showing a configuration of a pneumatic supply driving system for driving the pneumatic artificial muscle. In FIG. 4, 19 is an air pressure source such as a compressor, and 20 is an air pressure adjusting unit in which an air pressure filter 20a, an air pressure reducing valve 20b, and an air pressure lubricator 20c are combined. Reference numeral 21 denotes a 5-port flow rate control electromagnetic valve that controls the flow rate by driving a spool valve or the like with the force of an electromagnet. Reference numeral 22 denotes a control computer constituted by, for example, a general personal computer, which is equipped with a D / A board 22a, and outputs a voltage command value to the 5-port flow rate control solenoid valve 21 so that each fluid can be injected and discharged. The flow rate of each air flowing through the member 18 can be controlled.

  According to the air pressure supply drive system shown in FIG. 4, the high-pressure air generated by the air pressure source 19 is depressurized by the air pressure adjusting unit 20, adjusted to a constant pressure such as 600 kPa, and supplied to the 5-port flow control electromagnetic valve 23. The The opening degree of the 5-port flow rate control solenoid valve 21 is controlled in proportion to the voltage command value output from the control computer 22 via the D / A board 22a. A fluid injecting member 18 of a tubular elastic body 15 of a pair of pneumatic artificial muscles 201-1 and 201-2 is connected to the 5-port flow rate control electromagnetic valve 21, respectively. The pair of pneumatic artificial muscles 201-1 and 201-2 are arranged substantially parallel along the support rod 203, and the end of each tubular elastic body 15 on the fluid injection member 18 side is fixed to the end of the support rod 203. The support plate 202 is fixed. On the other end side of the tubular elastic body 15 of the pair of pneumatic artificial muscles 201-1 and 201-2, a T-shaped rotating member 204 that is rotatably supported by the support rod 203 with the rotary joint shaft 200 is provided. The other end of each of the tubular elastic bodies 15 of the pair of pneumatic artificial muscles 201-1 and 201-2 is rotatably supported by the rotating member 204. Therefore, as described below, when the tubular elastic bodies 15 of the pair of pneumatic artificial muscles 201-1 and 201-2 expand and contract, the rotating member 204 is driven to rotate forward and backward around the rotary joint axis 200. .

  When a positive voltage command value is input from the D / A board 22a to the 5-port flow control solenoid valve 21 from the control computer 22, the state indicated by the pneumatic circuit symbol A as shown in FIG. A flow path from the air pressure source 21 side to the fluid injecting member 18 side of the tubular elastic body 15 of the pneumatic artificial muscle 201-1 is opened via the 5-port flow control solenoid valve 21, and is proportional to the absolute value of the voltage command value. A flow rate of air is supplied to the pneumatic artificial muscle 201-1 side. On the pneumatic artificial muscle 201-2 side, the flow path from the fluid injection member 18 of the tubular elastic body 15 to the atmospheric pressure side is opened via the 5-port flow control solenoid valve 21, and the absolute value of the voltage command value is set. A proportional air flow is exhausted from the pneumatic artificial muscle 201-2 side to the atmosphere. Therefore, as shown in FIG. 4, the total length of the pneumatic artificial muscle 201-1 is reduced and the total length of the pneumatic artificial muscle 201-2 is extended, so that the joint shaft 200 is indicated by an arrow at a speed proportional to the absolute value of the voltage command value. Perform a clockwise rotation as shown.

  On the other hand, when a negative voltage command value is input from the control computer 22 to the 5-port flow control solenoid valve 21 from the D / A board 22a, the 5-port flow control solenoid valve 21 is switched to indicate the pneumatic circuit symbol. In the state indicated by B, the operation of the pneumatic artificial muscle 201-2 is reversed, and the joint axis 200 performs a counterclockwise movement. That is, the flow path from the air pressure source 19 side to the fluid injecting member 18 side of the tubular elastic body 15 of the pneumatic artificial muscle 201-2 is opened via the 5-port flow rate control electromagnetic valve 21, and the absolute value of the voltage command value is set. A proportional flow rate of air is supplied to the pneumatic artificial muscle 201-2 side. On the pneumatic artificial muscle 201-1 side, the flow path from the fluid injection member 18 of the tubular elastic body 15 to the atmospheric pressure side is opened via the 5-port flow control solenoid valve 21, and the absolute value of the voltage command value is set. A proportional air flow is exhausted from the pneumatic artificial muscle 201-1 side into the atmosphere. Accordingly, when the total length of the pneumatic artificial muscle 201-2 is reduced and the total length of the pneumatic artificial muscle 201-1 is extended, the joint axis 200 is shown in the direction opposite to the arrow at a speed proportional to the absolute value of the voltage command value. Perform a rotational motion.

  The operation of the joint structure having the wire guiding mechanism configured as described above will be described.

  5A and 5B are diagrams respectively showing the operation of the robot arm when the joint structure in the first embodiment of the present invention is applied to the robot arm.

  As described above, the two first linear actuators 4-1 and 4-2 of the first linear actuator 4 are different from the first linear actuator 4-1 on the left side of FIG. 1A and another one on the right side of FIG. 1A. The first linear actuator 4-2 is connected to the second structure 2 by the rotary joints 5-1 and 5-2 so as to face the first rotary joint 3 with the first structure 1 interposed therebetween. Accordingly, when the first linear actuator 4-1 on the left side of FIG. 1A expands and the other first linear actuator 4-2 on the right side of FIG. 1A contracts, as shown in FIG. 5A, the first rotation is performed. A counterclockwise rotational movement around the rotational axis 3a of the joint 3 occurs. Conversely, if the first linear actuator 4-1 on the left side in FIG. 1A contracts and the other first linear actuator 4-2 on the right side in FIG. 1A expands, the first rotary joint 3 rotates about the rotation axis 3a. A clockwise rotational movement of is generated.

  Here, the first embodiment of the present invention is characterized in that the arm is bent by the rotation guide pulleys 8-1 and 8-2, the fixed guide pulleys 9-1 and 9-2, and the movable rotation pulleys 10-1 and 10-2. The wires 7-1 and 7-2 are guided. The operation will be described with reference to FIGS. 6A and 6B.

  As described above, by the operation of the first linear actuators 4-1 and 4-2, the counterclockwise rotational motion around the rotational axis 3 a of the first rotary joint 3 of the second structure 2 as shown in FIG. 5A. 6A, as shown by an arrow A in FIG. 6A, relative to the rotary guide pulley 8-1 and the fixed guide pulley 9-1, the movable rotary pulley 10-1 around the rotary shaft 3a of the first rotary joint 3 Rotational motion occurs. At this time, the amount of the arm bending wire 7-1 applied to the circumferential portion of the rotation guide pulley 8-1 increases by the circumference corresponding to the angle α and decreases by the circumference corresponding to the angle β. The arm bending wire 7-1 is guided by the clockwise rotational movement of the movable rotating pulley 10-1 around the rotational axis 10-1a indicated by the arrow B, and the increment and angle corresponding to the circumference corresponding to the angle α. The decrements that are the circumference corresponding to β cancel each other. Further, since the angle α = the angle β, the distance L between the rotation guide pulley 8-1 and the movable rotation pulley 10-1 does not change after all. Therefore, a relative rotational movement with respect to the second structure 2 around the fulcrum 11-1a of the lever 11-1 does not occur.

  The wire guiding operation described above is the same for guiding the arm bending wire 7-2 by the rotation guide pulley 8-2, the fixed guide pulley 9-2, and the movable rotation pulley 10-2.

  Therefore, relative rotation around the second rotary joint 13 with respect to the second structure 2 of the hand 12 connected to the levers 11-1 and 11-2 by the hand drive wire 14-1 and the hand drive wire 14-2. The motion is not generated by the rotational motion around the rotational axis 3 a of the first rotary joint 3 of the second structure 2 due to the operation of the first linear actuator 4.

  On the other hand, when the second linear actuator 6-1 is contracted and the second linear actuator 6-2 is extended, the arm bending wire 7-1 is pulled and rotated as indicated by an arrow C in FIG. 6B. As indicated by an arrow D, the guide pulley 8-1 performs a clockwise rotational movement around the rotation axis 3a of the first rotary joint 3, and moves the arm bending wire 7-1 to the second linear actuator 6-1 side. To send to. However, since the arm bending wire 7-1 is fixed to the fixed guide pulley 9-1 (see FIG. 2), the movable rotating pulley 10-1 moves around the rotating shaft 10-1a as indicated by an arrow E. While performing a clockwise rotational movement, as indicated by an arrow F, a movement toward the rotation guide pulley 8-1 is performed, and the distance L between the rotation guide pulley 8-1 and the movable rotation pulley 10-1 is, for example, , The distance L1 before the exercise is shortened to a distance L2 (where L1> L2). Therefore, as shown in FIG. 5B, the lever 11-1 performs a relative counterclockwise rotational movement with respect to the second structure 2 around the fulcrum 11-1a. On the contrary, in the induction of the arm bending wire 7-2 by the rotation guide pulley 8-2, the fixed guide pulley 9-2, and the movable rotation pulley 10-2, as shown in FIG. A clockwise relative rotational movement with respect to the second structure 2 around −2a is performed.

  Therefore, as shown in FIG. 5B, the hand 12 connected to the levers 11-1 and 11-2 by the hand driving wire 14-1 and the hand driving wire 14-2 is rotated second with respect to the second structure 2. A counter-clockwise relative rotational movement around the joint 13 is performed.

  As described above, according to the joint structure of the first embodiment of the present invention, the rotation guide pulleys 8-1 and 8-2, the fixed guide pulleys 9-1 and 9-2, the movable rotation pulleys 10-1 and 10. -2, the arm bending wires 7-1 and 7-2 are guided, so that the first structure 1 is not affected by the rotational motion of the first rotary joint 3 around the rotation axis 3a. The driving force of the arranged second linear actuator 6 can be transmitted to the distal end side of the robot arm 100 beyond the first rotary joint 3.

  Therefore, the actuator that drives the movement around the second rotary joint 13 can be disposed on the base side of the robot arm 100 like the second linear actuator 6, and the inertia on the tip side of the robot arm 100 is small. As a result, control performance related to position control and force control is improved, and it is possible to operate at high speed. Further, since the inertia is small, the kinetic energy is also reduced, and the safety at the time of collision is improved.

  In the first embodiment, as an example, the second structure 2 rotates about 60 degrees clockwise and counterclockwise around the rotation axis 3a from the posture of FIG. 1A with respect to the first structure 1. The hand 12 can also rotate about the rotation axis 3a by about 60 degrees clockwise and counterclockwise from the posture of FIG. 1A with respect to the second structure 2.

(Second Embodiment)
FIG. 7 is a perspective view showing the structure of the joint structure in the second embodiment of the present invention. In FIG. 7, only main parts are described, and other configurations are the same as those of the first embodiment shown in FIGS. 1A and 1B, and are omitted. In addition, although it is hung so that a wire may be accommodated in each guide groove (similar to FIG. 1B) with respect to each pulley, in the following description and a corresponding figure, it is for simplification. The guide groove is omitted.

  In FIG. 7, reference numeral 23-1 denotes a first movable rotation guide pulley, and 24-1 denotes a second movable rotation guide pulley. The first movable rotation guide pulley 23-1 and the second movable rotation guide pulley 24-1 have the same radius, are fixed to each other, and rotate together around the rotation shaft 10-1a. It is an alternative to the movable rotating pulley 10-1 of the embodiment. The first movable rotation guide pulley 23-1 is disposed on the same plane as the rotation guide pulley 8-1, and the second movable rotation guide pulley 24-1 is disposed on the same plane as the fixed guide pulley 9-1. Has been.

  Next, the wire path of the joint structure in the second embodiment will be described. Here, the arm bending wire 7-1 of the first embodiment is divided into a first arm bending wire 27A-1 and a second arm bending wire 27B-1. That is, the first arm bending wire 27A-1 is hung on the rotation guide pulley 8-1 (see arrow (1)) and bent in direction (see arrow (2)), and then the first movable rotation guide pulley. 23-1 (see arrow (3A)), the end is fixed at a wire fixing point 25-1 on the circumference of the first movable rotation guide pulley 23-1.

  Further, the end of the second arm bending wire 27B-1 is fixed to the wire fixing point 26-1 on the circumference of the second movable rotating guide pulley 24-1, and the second arm bending wire 27B-1 is fixed. Is routed around the second movable rotating guide pulley 24-1 (see arrow (3B)), and after being guided to the fixed guide pulley 9-1 side (see arrow (4)), the fixed guide pulley 9-1 The other end of the second arm bending wire 27B-1 is fixed to the wire fixing point 28-1 of the fixed guide pulley 9-1.

  The same configuration as the above configuration is the first movable rotation guide pulley 23-2, the second movable rotation guide pulley 24-2, and the arm bending first wire 27A at positions opposite to each other across the second structure 2. -2 and the arm bending second wire 27B-2, which replaces the movable rotating pulley 10-2 of the first embodiment.

  According to the joint structure of the second embodiment of the present invention described above, the first movable rotation guide pulleys 23-1, 23-2 and the second movable rotation guide pulleys 24-1, 24-2 are arranged. As a result, the paths of the first arm bending wires 27A-1 and 27A-2 and the second arm bending wires 27B-1 and 27B-2 are within one plane, and the arm bending wires are connected between the pulleys. There is no place where the arm is stretched obliquely, and the risk of the arm bending wire dropping off from the pulley can be reduced, and the robot arm 100 can be operated more reliably.

(Third embodiment)
FIG. 8 is a perspective view showing the structure of the joint structure in the third embodiment of the present invention. FIG. 8 shows only main parts, and other configurations are the same as those of the first embodiment of FIGS. In addition, although it is hung so that a wire may be accommodated in each guide groove (similar to FIG. 1B) with respect to each pulley, in the following description and a corresponding figure, it is for simplification. The guide groove is omitted.

  The joint structure in the third embodiment differs from the joint structure in the first embodiment in the configuration of the fixed guide 29-1. The fixed guide 29-1 is not in the shape of a disk like the fixed guide pulleys 9-1 and 9-2 of the joint structure in the first embodiment, but only in the vicinity of the portion where the arm bending wire 7-1 contacts. And a groove for guiding the arm bending wire 7-1 is formed. For example, the arm bending wire 7-1 is wound around the arc-shaped portion of the fixed guide 29-1 in the order of arrows (1) to (5) as in FIG.

  According to the above configuration, for example, the fixed guide 29-1 can be configured by forming a part of the first structure 1 and a part of other parts fixed to the first structure 1 in an arc shape. Therefore, a dedicated part for the fixed guide 29-1 is not necessary, and the number of parts can be reduced and the size can be reduced.

(Fourth embodiment)
9A and 9B are general views showing a robot arm when a joint structure in a joint mechanism according to a fourth embodiment of the present invention is applied to the robot arm.

  9A and 9B, reference numerals 30-1 and 30-2 denote first rotation guide pulleys, which are coaxial with the rotation shaft 3a of the first rotation joint 3 at respective positions facing each other with the second structure 2 interposed therebetween. The first structure 1 or the second structure 2 is rotatably arranged so as to be freely rotatable around the rotation shaft 3a via a bearing or the like. 9A and 9B, the first rotation guide pulley 30-2 on the back side is not shown because it is a shadow of the first rotation guide pulley 30-1 on the near side.

  Reference numerals 31-1 and 31-2 denote second rotation guide pulleys having a radius equal to that of the first rotation guide pulleys 30-1 and 30-2, and the first rotation guide pulleys 31-1 and 31-2 are opposed to each other with the second structure 2 therebetween. The rotary joint 3 is rotatably arranged so as to be coaxial with the rotary shaft 3a of the rotary joint 3 and the rotary shafts of the first rotary guide pulleys 30-1 and 30-2, and freely around the rotary shaft 3a via a bearing or the like. It can be rotated and can also be rotated relative to the first rotation guide pulleys 30-1 and 30-2. 9A and 9B, the second rotation guide pulleys 31-1 and 31-2 on the back side are not shown because they are shadows of the second rotation guide pulley 31-1 on the near side.

  32-1 and 32-2 are auxiliary rotation guide pulleys disposed in the first structure 1 so as to be rotatable with respect to the rotary shafts 32-1a and 32-2a via bearings or the like. The first structure is located at a position substantially opposite to the lower end of the linear actuators 6-1 and 6-2 and the second rotation guide pulleys 31-1 and 31-2 across the second structure 2. It is rotatably arranged with respect to the body 1 and can freely rotate. 9A and 9B, the auxiliary rotation guide pulley 32-2 on the back side is not shown because it is a shadow of the auxiliary rotation guide pulley 32-1 on the near side.

  Next, the wire path of the joint structure in the fourth embodiment will be described with reference to FIG. FIG. 10 is a perspective view showing details of the structure of the joint structure in the fourth embodiment of the present invention. In addition, although it is hung so that a wire may be accommodated in each guide groove (similar to FIG. 1B) with respect to each pulley, in the following description and a corresponding figure, it is for simplification. The guide groove is omitted.

  The arm bending wire 7-1 having one end fixed to the lower end of the second linear actuator 6-1 is guided to the first rotation guide pulley 30-1, and is routed by the first rotation guide pulley 30-1. Is bent (see arrow (11)), then guided from below the joint shaft 3a of the first rotary joint 3 to the movable rotary pulley 10-1 on the paper surface of FIG. 10 (see arrow (12)), and further The movable rotating pulley 10-1 is guided downward on the paper surface of FIG. Thereafter, the arm bending wire 7-1 is bent by the movable rotating pulley 10-1 so as to change its direction (see arrow (13)), and the upper side of the movable rotating pulley 10-1 on the paper surface of FIG. Thus, the second rotation guide pulley 31-1 is guided upward on the paper surface of FIG. 10 (see arrow (14)). Thereafter, the arm bending wire 7-1 makes one round along the outer periphery of the second rotation guide pulley 31-1 (see arrow (15)), and the auxiliary rotation guide pulley 32- 1 is led downward on the paper surface (see arrow (16)). The arm bending wire 7-1 guided to the auxiliary rotation guide pulley 32-1 is changed in direction by being along the outer periphery of the auxiliary rotation guide pulley 32-1 (see the arrow (17)), and the upper part on the paper surface. Finally, the other end of the arm bending wire 7-1 is substantially the same as the lower end of the second linear actuator 6-1 to which the one end of the arm bending wire 7-1 is fixed. It is fixed in the same place.

  A configuration similar to the above configuration has the first rotation guide pulley 30-2, the second rotation guide pulley 31-2, the auxiliary rotation guide pulley 32-2 and the arm at positions opposite to each other across the second structure 2. And a bending wire 7-2.

  The operation of the joint structure according to the fourth embodiment of the present invention described above will be described with reference to FIG.

  Regarding the relative swinging motion of the first structure 1 and the second structure 2 around the rotation axis 3a of the first rotary joint 3, the first structure 1 and the second structure are based on the same principle as in FIG. 6A. The movements of the levers 11-1 and 11-2 are not affected by the relative swinging movement of the two.

  On the other hand, when the second linear motion actuator 6-1 contracts, both ends of the arm bending wire 7-1 are pulled in the directions indicated by arrows A and B. In order to cope with this, the first rotation guide pulley 30-1 rotates clockwise as indicated by an arrow C, and sends the arm bending wire 7-1 upward. Further, the auxiliary rotation guide pulley 32-1 rotates clockwise as indicated by an arrow D, and the second rotation guide pulley 31-1 rotates counterclockwise as indicated by an arrow E, respectively. The wire 7-1 is sent out. Eventually, the movable rotating pulley 10-1 is attracted as shown by the arrow F, and the distance L from the rotating shaft 3a of the first rotating joint 3 to the rotating shaft 10-1a of the movable rotating pulley 10-1 is the distance before the exercise. It changes from L1 to distance L3. In addition, in FIG. 11, the movable rotation pulley 10-1 shown with the dotted line has shown the position of the movable rotation pulley 10-1 in FIG. 6B of 1st Embodiment, and rather than the distance L2 in this position, The distance L3 in FIG. 11 is smaller, and the moving distance of the movable rotating pulley 10-1 is increased by the difference (L2-L3).

  According to the joint structure of the fourth embodiment of the present invention, the second rotation guide pulleys 31-1 and 31-2 and the auxiliary rotation guide pulleys 32-1 and 32-2 are arranged, thereby bending the arm. Since the wires 7-1 and 7-2 are pulled at both ends by the second linear actuators 6-1 and 6-2, respectively, this is the amount of movement of the movable rotary pulleys 10-1 and 10-2 (L1-L2). The value of) is twice as large as the amount of movement (L1-L2) with respect to the same contraction amount of the second linear actuators 6-1, 6-2 as compared with the case of the first embodiment. Therefore, the movable range of the joint of the robot arm can be increased.

(Fifth embodiment)
FIG. 12 is an overall view showing a robot arm when the joint structure according to the fifth embodiment of the present invention is applied to the robot arm.

  In FIG. 12, 33-1 and 33-2 are 3rd rotation guide pulleys, and it is coaxial with the rotating shaft 3a of the 1st rotation joint 3 in each position which opposes on both sides of the 2nd structure 2. In FIG. It is rotatably arranged and can be freely rotated around the rotation shaft 3a via a bearing or the like. In FIG. 12, the third rotation guide pulley 33-2 on the back side is not shown because it is a shadow of the third rotation guide pulley 33-1 on the near side.

  Reference numerals 34-1 and 34-2 denote fourth rotation guide pulleys having the same radius as the third rotation guide pulleys 33-1 and 33-2, and the rotation shaft 34 fixed to the upper protruding portion 2c of the second structure 2. -1a and 34-2a are rotatably arranged on the second structure 2 at respective positions facing the second structure 2 with bearings or the like interposed therebetween, and the rotation shaft 34-1a , 34-2a as a center, it can rotate relative to the second structure 2.

  Reference numerals 35-1 and 35-2 denote first parallel links, each of which is connected to the first structure 1 at fulcrums 35-1a and 35-2a, and the fulcrums 35-1a and 35-2a. Is capable of swinging relative to the first structure 1.

  36-1 and 36-2 are 2nd parallel links, and each one end part is connected with the other end part of the 1st parallel links 35-1 and 35-2 in the fulcrum 36-1a and 36-2a. Oscillating relative to the first parallel links 35-1 and 35-2 around the fulcrums 36-1a and 36-2a. The other end portions of the second parallel links 35-1 and 35-2 are fixed to the fourth rotation guide pulleys 34-1 and 34-2, respectively, and the second parallel links 35-1 and 35-2 are fixed. The fourth rotation guide pulleys 34-1 and 34-2 are relatively immovable.

  The first parallel links 35-1 and 35-2, the second parallel links 36-1 and 36-2, the first structure 1, and the second structure 2 are fulcrums 35-1 a and 35-2 a and a fulcrum 36. -1a, 36-2a, the rotation shaft 3a of the first rotation joint 3, and the rotation shafts 34-1a, 34-2a of the fourth rotation guide pulleys 34-1 and 34-2 are used as four fulcrum links. (Parallel link structure).

  Next, the wire path of the wire guiding mechanism of the joint structure in the fifth embodiment will be described with reference to FIG. FIG. 13 is a perspective view showing details of the structure of the joint structure in the fifth embodiment of the present invention. In addition, although it is hung so that a wire may be accommodated in each guide groove (similar to FIG. 1B) with respect to each pulley, in the following description and a corresponding figure, it is for simplification. The guide groove is omitted.

  The arm bending wire 7-1 having one end fixed to the second linear actuator 6-1 is guided to the third rotation guide pulley 33-1, and the path is bent by the third rotation guide pulley 33-1. After (see arrow (21)), the lower side of the movable rotary pulley 10-1 on the plane of FIG. 13 from the lower side of the joint shaft 3a of the first rotary joint 3 to the movable rotary pulley 10-1 on the plane of FIG. (See arrow (22)). Thereafter, the arm bending wire 7-1 is bent so as to change its direction by the movable rotating pulley 10-1 (see arrow (23)), and the arm bending wire 7-1 is changed from the upper side on the paper surface of FIG. 13 of the movable rotating pulley 10-1. The two-rotation guide pulley 34-1 is guided upward on the paper surface of FIG. 13 (see arrow (24)). After that, after the arm bending wire 7-1 runs along the outer periphery of the fourth rotation guide pulley 34-1 (see arrow (25)), the end is fixed to the second rotation guide pulley 34-1 by the wire fixing pin 34p. Is done.

  The path of the arm bending wire 7-2 with respect to the third rotating guide pulley 33-2, the fourth rotating guide pulley 34-2, and the movable rotating pulley 10-2 is the same as the path of the arm bending wire 7-1. Therefore, detailed description is omitted.

  The operation of the joint structure according to the fifth embodiment of the present invention described above will be described with reference to FIG.

  When the counterclockwise rotational motion around the rotational axis 3a of the first rotary joint 3 of the second structure 2 is generated by the operation of the first linear actuators 4-1, 4-2, the arrow A in FIG. As shown, relative rotational movement of the movable rotary pulley 10-1 and the fourth rotary guide pulley 34-1 about the rotary shaft 3a of the first rotary joint 3 with respect to the third rotary guide pulley 33-1 occurs. . At this time, the amount of the arm bending wire 7-1 applied to the circumferential portion of the third rotation guide pulley 33-1 increases by the circumference corresponding to the angle α.

  On the other hand, the perpendicular line X of the arm bending wire 7-1 spanned between the movable rotating pulley 10-1 and the fourth rotating guide pulley 34-1 when the movable rotating pulley 10-1 is at the position P. Arm bending wire stretched between the movable rotating pulley 10-1 and the fourth rotating guide pulley 34-1 when the movable rotating pulley 10-1 is in the Q position. Assuming that the angle formed by the perpendicular Z of 7-1 is β, the fourth rotation guide pulley 34-1 is connected to the first structure 1 by the parallel link structure, so that the rotational motion indicated by the arrow C does not occur. (However, the relative rotational movement of the fourth rotation guide pulley 34-1 and the second structure 2 occurs.) Therefore, the counterclockwise around the rotation axis 3a of the first rotation joint 3 of the second structure 2 is obtained. Bending arm by rotational movement in direction The amount of the wire 7-1 is applied to the circumferential portion of the fourth rotating guide pulley 34-1 is reduced by the circumference amount corresponding to the angle beta.

  Here, considering the geometrical relationship, since angle α = angle β, the increase corresponding to the angle α and the decrease corresponding to the angle β are equal to each other. After cancellation, the distance L between the first rotation guide pulley 33-1 and the movable rotation pulley 10-1 does not change. Therefore, a relative rotational movement with respect to the second structure 2 around the fulcrum 11-1a of the lever 11-1 does not occur.

  When the second linear actuator 6-1 contracts, the distance from the rotary shaft 3a of the first rotary joint 3 to the rotary shaft 10-1a of the movable rotary pulley 10-1 changes according to the same principle as in FIG. 6B. .

  According to the joint structure of the fifth embodiment of the present invention, the fourth rotation guide pulleys 34-1 and 34-2 to which the parallel link structure is connected are movable with the third rotation guide pulleys 33-1 and 33-2. Since it becomes possible to arrange | position in the same plane as the rotation pulleys 10-1 and 10-2, compared with the case of 1st Embodiment, the thickness along the axial direction of the rotating shaft 3a of the 1st rotation joint 3 is set. It can be made smaller. Accordingly, a robot arm having a compact joint structure can be provided. Further, the fourth rotation guide pulleys 34-1 and 34-2 can be disposed in the same plane as the third rotation guide pulleys 33-1 and 33-2 and the movable rotation pulleys 10-1 and 10-2. Therefore, the arm bending wires 7-1 and 7-2 are not easily detached from the guide grooves of the respective pulleys, and are suitable for high-speed movement of the robot arm.

(Sixth embodiment)
FIG. 15 is an overall view showing a robot arm when the joint structure according to the sixth embodiment of the present invention is applied to the robot arm.

  In FIG. 15, reference numerals 37-1 and 37-2 denote rotation guide pulleys, such as bearings so as to be coaxial with the rotation shaft 3 a of the first rotation joint 3 at respective positions facing each other with the second structure 2 interposed therebetween. Is arranged so as to be rotatable with respect to the rotary shaft 3a, and can be freely rotated around the rotary shaft 3a. In FIG. 15, the rotation guide pulley 37-2 on the back side is not shown because it is a shadow of the rotation guide pulley 37-1 on the near side.

  Reference numerals 38-1 and 38-2 denote movable guide pulleys having the same radius as the rotation guide pulleys 37-1 and 37-2, and rotatably disposed at the upper end portion of the lever 11-1 and the lower end portion 11-2 of the lever. Thus, it can rotate relative to the levers 11-1 and 11-2 around the rotation shafts 38-1a and 38-2a.

  Reference numerals 39-1 and 39-2 denote first parallel links, each of which is rotatably connected to the first structure 1 at fulcrums 35-1a and 35-2a. Oscillating motion is possible relative to the first structure 1 around 2a.

  Each of 40-1 and 40-2 is rotatably connected to translation / rotation joints 41-1 and 41-2, and the other end is fixed to movable guide pulleys 38-1 and 38-2. Two parallel links, which are connected to the first parallel links 39-1 and 39-2 by translation / rotation joints 41-1 and 41-2 so as to be able to translate and rotate. The translation / rotation joint 41-1 is slidably fitted in or clamped relative to the first parallel link 39-1 in the directions indicated by arrows A and B in FIG. 15 and translated. The translation / rotation joint 41-2 has the same structure with respect to the first parallel link 39-2. Therefore, the first parallel links 39-1 and 39-2 and the second parallel links 40-1 and 40-2 can be relatively translated by the translation / rotation joints 41-1 and 41-2. Dynamic movement is possible. The other ends of the second parallel links 40-1 and 40-2 are fixed to movable guide pulleys 38-1 and 38-2, respectively. Since the movable guide pulleys 38-1 and 38-2 are relatively immovable, respectively, the second parallel link 40-1, the movable guide pulley 38-1, the second parallel link 40-2, and the movable guide Each of the pulleys 38-2 is configured to rotate integrally.

  Therefore, the first parallel links 39-1 and 39-2, the second parallel links 40-1 and 40-2, the first structure 1, and the second structure 2 are fulcrums 35-1a, 35-2a, Four-joint link structure (parallel link structure) with translation / rotation joints 41-1 and 41-2, rotation shaft 3a of first rotation joint 3 and rotation shafts 38-1a and 38-2a of the movable guide pulley as four fulcrums ).

  Next, the wire path of the joint structure in the sixth embodiment will be described with reference to FIG. FIG. 16 is a perspective view showing details of the structure of the joint structure according to the sixth embodiment of the present invention. In addition, although it is hung so that a wire may be accommodated in each guide groove (similar to FIG. 1B) with respect to each pulley, in the following description and a corresponding figure, it is for simplification. The guide groove is omitted.

  The arm bending wire 7-1 having one end fixed to the second linear actuator 6-1 is guided to the rotation guide pulley 37-1, and the path is bent by the rotation guide pulley 37-1. From the lower side of the joint shaft 3a of the first rotary joint 3 on the paper surface, the movable rotary pulley 38-1 is guided to the lower side on the paper surface of FIG. 13 of the movable rotary pulley 38-1. Thereafter, after the arm bending wire 7-1 runs along the outer periphery of the rotary pulley 38-1, the end thereof is fixed to the movable pulley 38-1 by the wire fixing pin 38p.

  Since the path of the arm bending wire 7-2 with respect to the rotation guide pulley 37-2 and the movable pulley 38-2 is the same as the path of the arm bending wire 7-1, detailed description thereof is omitted.

  The operation of the joint structure according to the sixth embodiment of the present invention described above will be described with reference to FIG.

  When the counterclockwise rotational motion around the rotational axis 3a of the first rotary joint 3 of the second structure 2 is generated by the operation of the first linear actuators 4-1, 4-2, the arrow A in FIG. As shown, relative rotational movement of the movable pulley 38-1 around the rotation axis 3a of the first rotary joint 3 with respect to the rotation guide pulley 37-1 occurs. At this time, the amount of the arm bending wire 7-1 applied to the circumferential portion of the first rotation guide pulley 37-1 increases by the circumference corresponding to the angle α.

  On the other hand, when the movable pulley 38-1 is at the position P, it is parallel to the perpendicular line X of the arm bending wire 7-1 spanned between the first rotation guide pulley 37-1 and the movable pulley 38-1. Of the arm bending wire 7-1 spanned between the first rotation guide pulley 37-1 and the movable pulley 38-1 when the auxiliary line Y and the movable pulley 38-1 are at the position Q. Assuming that the angle formed by the perpendicular Z is β, the movable pulley 38-1 is connected to the first structure 1 by the parallel link structure, and therefore the rotational motion indicated by the arrow B does not occur (however, the movable pulley 38- 1 and the lever 11-1 are caused to rotate relative to each other.) Therefore, the arm bending wire 7 is obtained by the counterclockwise rotational movement around the rotation axis 3a of the first rotary joint 3 of the second structure 2. -1 is movable pulley 38- The amount applied to the circumferential portion is reduced by the circumference amount corresponding to the angle beta.

  Here, considering the geometrical relationship, since angle α = angle β, the increase corresponding to the angle α and the decrease corresponding to the angle β are equal to each other. After cancellation, the distance L between the rotation guide pulley 37-1 and the movable pulley 38-1 does not change. Therefore, a relative rotational movement with respect to the second structure 2 around the fulcrum 11-1a of the lever 11-1 does not occur.

  When the second linear actuator 6-1 contracts, the arm bending wire 7-1 is pulled. However, since the end of the wire 7-1 is fixed to the movable pulley 38-1, the movable pulley 38- 1 is drawn toward the rotary guide pulley 37-1, and the distance L from the rotary shaft 3a of the first rotary joint 3 to the rotary shaft 38-1a of the movable pulley 38-1 changes. At this time, the translation / rotation joint 41-1 approaches the fulcrum 35-1a along the first parallel link 39-1 when the distance L is shortened by contraction of the second linear actuator 6-1. Translate in direction and maintain parallel link structure.

  The joint structure of the sixth embodiment of the present invention corresponds to a structure in which the second rotation guide pulleys 34-1 and 34-2 and the movable guide pulleys 10-1 and 10-2 of the fifth embodiment are integrated. To do.

  According to the joint structure of the sixth embodiment of the present invention, if there are only the rotation guide pulleys 37-1 and 37-2 and the movable pulleys 38-1 and 38-2 as the guide pulley, the operation can be performed. Can be reduced. Therefore, it is possible to provide a robot arm having a simple joint structure with a small number of parts.

(Seventh embodiment)
19A, 19B, and 19C are general views showing the structure of the wire guiding mechanism in the joint mechanism according to the seventh embodiment of the present invention. A seventh embodiment of the present invention shown in FIGS. 19A, 19B, and 19C is an example in which two movable rotating pulleys are provided.

  19A, 19B, and 19C, 401 is a rod-shaped first structure, 402 is a rod-shaped second structure, and the first structure 401 and the second structure 402 are connected by a rotating joint 403. Thus, the first structure 401 and the second structure 402 are relatively rotatable about the joint axis 403a of the rotary joint 403.

  Reference numeral 404 denotes a rotary guide pulley with a guide groove 404a, which is coaxial with the rotary shaft 403a of the rotary joint 403 and is disposed in the second structure 2 so as to be rotatable with respect to the rotary shaft 403a via a bearing or the like. Thus, it can freely rotate around the rotation shaft 403a.

  Reference numeral 405 denotes a fixed guide pulley with a guide groove 405a, which is an example of a fixed guide, and is disposed so as to have the same radius as that of the rotary guide pulley 404 and to be coaxial with the rotary shaft 403a of the rotary joint 403. In addition, the fixed guide pulley 405 is fixed to the first structure 401, and no relative rotational movement occurs between the fixed guide pulley 405 and the first structure 401.

  A gripper 406 includes a first finger 406a, a second finger 406b, and a hinge 406c. The first finger 406a and the second finger 406b can be opened and closed by a hinge 406c, and the hinge 406c is an end of the second structure 402 (an end different from the end connected to the first structure 401). ).

  Reference numeral 407 denotes a first movable rotating pulley with a guide groove 407b, which is disposed at the base end portion of the first finger 406a and is rotatable around the rotating shaft 407a.

  Reference numeral 408 denotes a second movable rotating pulley with a guide groove 408b, which is disposed at the base end portion of the second finger 406b and is rotatable around the rotating shaft 408a.

  Reference numeral 409 denotes a torsion coil spring. The coil portion is hooked on the hinge 406c, and both ends are hooked on the rotating shaft 407a of the first movable rotating pulley 407 and the rotating shaft 408a of the second movable rotating pulley 408, respectively. As a result, the gripper 406 tends to be held open as shown in FIG. 19A.

  Reference numeral 410 denotes a gripper drive wire, and one end of the gripper drive wire 410 is connected to a first drive actuator (for example, two first linear actuators 4-1 and 4-2 such as pneumatic artificial muscles in FIG. 1A). The gripper drive wire 410 is hung in the order of the guide groove 404 a of the rotation guide pulley 404, the guide groove 408 b of the second movable rotation pulley 408, and the guide groove 407 b of the first movable rotation pulley 407. The end is fixed to the fixed guide pulley 405 by a wire fixing pin 410p.

  Reference numeral 411 denotes a rotary joint drive pulley with a guide groove 411a, which is disposed so as to be coaxial with the rotary shaft 403a of the rotary joint 403. The rotary joint drive pulley 411 is fixed to the second structure 402, and no relative rotational motion occurs between the rotary joint drive pulley 411 and the second structure 402.

  Reference numeral 412 denotes a rotary joint drive wire, which is wound around the guide groove 411a of the rotary joint drive pulley 411, and has both end portions of a second drive actuator and a third drive actuator (both not shown, but an actuator can be configured, for example, pneumatic artificial It is fixed to a line, a motor, a cylinder, etc.).

  Next, the path of the gripper drive wire 410 with respect to the rotation guide pulley 404, the fixed guide pulley 405, the first movable rotation pulley 407, and the second movable rotation pulley 408 will be described with reference to FIG. As described above, each pulley is hung so that a wire is accommodated in each guide groove. However, in the following description, description of the guide groove is omitted.

  The gripper drive wire 410, one end of which is fixed to the first drive actuator, is guided to the rotation guide pulley 404, and after rotating around the rotation guide pulley 404 substantially once, the joint shaft 403a of the rotation joint 403 on the paper surface of FIG. The second movable rotary pulley 408 is guided downward from the lower side on the paper surface of FIG. 20 of the second movable rotary pulley 408 from below. After that, the gripper driving wire 410 is bent by the second movable rotating pulley 408 so as to change the direction upward, to the first movable rotating pulley 407 and to the right side of the first movable rotating pulley 407 on the paper surface of FIG. Led. Thereafter, the gripper drive wire 410 is bent by the first movable rotating pulley 407 so as to change the direction to the left, and the upper side of the first movable rotating pulley 407 in FIG. It is guided upward on the paper. Thereafter, the gripper drive wire 410 is fixed to the fixed guide pulley 405 at the end thereof by the wire fixing pin 410p after running along the outer periphery of the fixed guide pulley 405.

  The operation of the wire guiding mechanism having the above configuration will be described.

  When the gripper drive wire 410 is driven as indicated by an arrow X in FIG. 19B, the rotation guide pulley 404, the first movable rotation pulley 7, the second principle, and the second principle according to the same principle as described in FIG. 6B in the first embodiment. The operation is such that the distance between the rotation axes of the movable rotating pulley 408 is shortened, and the gripper 406 is closed from the state of FIG. 19A to the state of FIG. 19B. On the other hand, when the gripper drive wire 410 is driven in the direction of loosening in the direction opposite to the arrow X, the gripper 406 is opened from the state of FIG. 19B to the state of FIG. 19A by the repulsive force of the torsion coil spring 409.

  Next, when the rotary joint drive wire 412 is driven as indicated by an arrow Y in FIG. 19C, the rotary joint drive wire 412 is wound around the rotary joint drive pulley 411, and the rotary joint drive pulley 411 is attached to the second structure 402. Since it is fixed, a rotational motion of the rotary joint 403 occurs, and the gripper 406 performs a counterclockwise swinging motion from the state of FIG. 19A to the state of FIG. 19C. On the other hand, when the rotary joint drive wire 412 is driven in the direction opposite to the arrow Y, the gripper 406 performs a clockwise swing motion.

  During this oscillating movement, the distance between the rotation guide pulley 404, the first movable rotary pulley 407, and the second movable rotary pulley 408 between the rotation axes is determined according to the same principle as described in FIG. 6A in the first embodiment. The gripper 406 does not operate.

  As described above, according to the wire guiding mechanism of the seventh embodiment of the present invention, the gripper drive wire 410 is guided by the rotation guide pulley 404, the fixed guide pulley 405, the first movable rotation pulley 407, and the second movable rotation pulley 408. With this configuration, the opening / closing operation of the gripper 406 can be independently driven by the gripper driving wire 410 without being affected by the rotational motion of the rotary joint 403 around the rotation shaft 403a.

  By applying the gripper driving mechanism as described above, it is possible to realize a robot forceps system for laparoscopic surgery or remote surgery.

  In addition, this invention is not limited to the said embodiment, It can implement with another various aspect.

  For example, as shown in FIGS. 18A and 18B, instead of a swinging lever, linear guides 300-1 and 300-2 are provided along the longitudinal direction of the second structure 2, and these linear guides 300-1 are provided. , 300-2, the movable rotating pulleys 10-1 and 10-2 can be freely moved along the longitudinal direction of the second structure 2 by the arm bending wires 7-1 and 7-2. The same effect as a lever can be produced.

  In the various embodiments described above, the actuator that drives the robot arm is a linear actuator. However, the present invention is not limited to this. For example, even a rotary electric motor has a pulley on the rotation shaft of the motor. The same effect is exhibited even in a structure in which the wire is wound by rotation of the motor.

  In the various embodiments described above, the linear actuator is a pneumatic artificial muscle. However, the present invention is not limited to this, and the same effect can be obtained with other linear actuators such as a pneumatic cylinder, a hydraulic cylinder, and an electric linear actuator. Demonstrate.

  It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.

The joint structure of the present invention is useful as a joint structure in a joint mechanism of an articulated robot arm. Also applicable not only to robot arms, but also to joint structures for joint mechanisms of mechanical devices, such as joint mechanisms for rotation mechanisms in production facilities, etc., and joint structures for joint mechanisms of multi-joint robot arms of medical telesurgical devices Is possible.

  Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

These and other objects and features of the invention will become apparent from the following description taken in conjunction with the preferred embodiments with reference to the accompanying drawings.
FIG. 1A is a plan view showing almost the entire robot arm when the joint structure according to the first embodiment of the present invention is applied to the robot arm. FIG. 1B is a bottom view showing substantially the entire robot arm when the joint structure according to the first embodiment of the present invention is applied to the robot arm. FIG. 2 is a perspective view showing details of the structure of the joint structure according to the first embodiment of the present invention. FIG. 3 is a diagram showing the structure of a pneumatic artificial muscle that can constitute a linear motion actuator group as an example of a joint structure driving apparatus according to the first embodiment of the present invention. FIG. 4 is a diagram showing a configuration of a pneumatic supply drive system for driving the pneumatic artificial muscle. FIG. 5A is a side view showing the operation of the robot arm when the joint structure in the first embodiment of the present invention is applied to the robot arm. FIG. 5B is a side view showing the operation of the robot arm when the joint structure in the first embodiment of the present invention is applied to the robot arm. FIG. 6A is a diagram illustrating a wire guiding operation of the joint structure according to the first embodiment of the present invention during the operation of the first linear actuator. FIG. 6B is a diagram illustrating a wire guiding operation of the joint structure according to the first embodiment of the present invention during the operation of the second linear actuator. FIG. 7 is a perspective view showing details of the structure of the joint structure according to the second embodiment of the present invention. FIG. 8 is a perspective view showing details of the structure of the joint structure according to the third embodiment of the present invention. FIG. 9A is a side view showing the entire robot arm when the joint structure according to the fourth embodiment of the present invention is applied to the robot arm. FIG. 9B is a side view showing the entire robot arm when the joint structure according to the fourth embodiment of the present invention is applied to the robot arm. FIG. 10 is a perspective view showing details of the structure of the joint structure according to the fourth embodiment of the present invention. FIG. 11 is a diagram illustrating the operation of the joint structure according to the fourth embodiment of the present invention. FIG. 12 is a plan view showing almost the entire robot arm when the joint structure according to the fifth embodiment of the present invention is applied to the robot arm. FIG. 13 is a perspective view showing details of the structure of the joint structure according to the fifth embodiment of the present invention. FIG. 14 is a diagram illustrating the operation of the joint structure according to the fifth embodiment of the present invention. FIG. 15 is a plan view showing almost the entire robot arm when the joint structure according to the sixth embodiment of the present invention is applied to the robot arm. FIG. 16 is a perspective view showing details of the structure of the joint structure according to the sixth embodiment of the present invention. FIG. 17 is a diagram illustrating the operation of the joint structure according to the sixth embodiment of the present invention. FIG. 18A is a side view showing substantially the entire robot arm when a joint structure according to another embodiment of the present invention is applied to the robot arm. FIG. 18B is a bottom view showing almost the entire robot arm when the joint structure according to another embodiment of the present invention is applied to the robot arm. FIG. 19A is an overall view showing a structure of a wire guiding mechanism in a joint mechanism according to a seventh embodiment of the present invention and showing a gripper in an open state. FIG. 19B is an overall view showing the structure of the wire guiding mechanism in the joint mechanism according to the seventh embodiment of the present invention and showing the gripper in a closed state. FIG. 19C is an overall view showing the structure of the wire guiding mechanism in the joint mechanism according to the seventh embodiment of the present invention and showing a state where the gripper is swung. FIG. 20 is a perspective view showing the structure of the wire guiding mechanism in the joint mechanism according to the seventh embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st structure 1a Support plate 2 2nd structure 3 1st rotation joint 3a Rotating shaft of 1st rotation joint 4 1st linear motion actuator 4-1, 4-2 1st linear motion actuator 5-1, 5- 2 Joint 6 Second linear actuator 6-1, 6-2 Second linear actuator 7-1, 7-2 Arm bending wire 8-1, 8-2 Rotating guide pulley 9-1, 9-2 Fixed guide Pulley 10-1, 10-2 Movable rotation guide pulley 10-1a, 10-2a Rotation shaft 11-11, 11-2 lever 11-1a, 11-2a Lever fulcrum 12 Hand 13 Second rotation Joint 13a Rotating shafts 14-1 and 14-2 of second rotary joint 15 Wire for hand drive 15 Tubular elastic body 16 Restraining member 17 Sealing member 18 Fluid injecting member 19 Air pressure source 20 Air pressure adjusting unit G 20a Pneumatic filter 20b Pneumatic pressure reducing valve 20c Pneumatic lubricator 21 5-port flow control solenoid valve 22 Control computer 22a D / A board 23-1, 23-2 First movable rotation guide pulley 24-1, 24-2 Second movable Rotation guide pulleys 25-1, 25-2 Wire fixing points of the first movable rotation guide pulley 26-1, 26-2 Wire fixing points of the second movable rotation guide pulley 27A-1, 27A-2 First wire for arm bending 27B-1, 27B-2 Arm bending second wires 28-1, 28-2 Fixed guide pulley wire fixing points 29-1, 29-2 Fixed guides 30-1, 30-2 First rotating guide pulley 31- 1, 31-2 Second rotation guide pulley 32-1, 32-2 Auxiliary rotation guide pulley 33-1, 33-2 First rotation guide pulley 34-1 and 34-2 2nd rotation guide pulley 35-1, 35-2 1st parallel link 36-1, 36-2 2nd parallel link 37-1, 37-2 rotation guide pulley 38-1, 38- 2 movable guide pulleys 39-1 and 39-2 first parallel links 40-1 and 40-2 second parallel links 41-1 and 41-2 translation / rotation joint 100 robot arm 200 joint shafts 201-1 and 201-2 Pneumatic artificial muscle 202 Support plate 203 Support rod 204 Rotating member

Claims (2)

A first structure;
A second structure;
A first rotary joint that rotatably connects the first structure and the second structure;
A first rotation guide with a guide groove disposed on the first structure or the second structure so as to be coaxial with the rotation axis of the first rotation joint and rotatable about the rotation axis and rotatable relative to each other. A pulley and a second rotating guide pulley with a guide groove;
A movable rotating guide pulley with a guide groove disposed so as to be relatively movable with respect to the second structure;
A mechanism for changing a distance between the first or second rotation guide pulley and the movable rotation guide pulley;
An auxiliary rotation guide pulley with a guide groove rotatably disposed in the first structure,
From one end side to the other end side, the guide groove of the first rotation guide pulley, the guide groove of the movable rotation guide pulley, the guide groove of the second rotation guide pulley, and the guide of the auxiliary rotation guide pulley A wire spanned in the order of the grooves,
A first drive device having one end fixed to the first structure and the other end connected to the second structure, the second drive capable of rotating the second structure around the first rotary joint;
One end is fixed to the first structure, and both the one end and the other end of the wire are fixed to the other end, and the wire is guided through the wire while being guided by the rotation of the auxiliary rotation guide pulley. A second drive device that drives the mechanism to move the movable rotation guide pulley relative to the second structure,
Without driving the second driving device, the first driving device drives the second structure to rotate about the rotation axis of the first rotary joint, and the first and second rotation guide pulleys. Generating a relative rotational motion of the movable rotating pulley around the rotational axis of the first rotational joint, and rotating in a direction opposite to the rotational direction of the rotational motion around the rotational axis of the movable rotational pulley. As a result of the wire being guided by the rotational movement, the increase and decrease of the amount of the wire applied to the circumferential portion of the guide groove of each of the first and second rotation guide pulleys is offset, and the first and second rotation guides A robot arm that prevents the distance between each pulley and the movable rotating pulley from being changed. A hand arranged via a second rotary joint at the tip of the second structure opposite to the first rotary joint side;
By connecting the movable rotation guide pulley and the hand and moving the movable rotation guide pulley relative to the second structure by driving the second driving device, the second rotation joint is rotated. The robot arm according to claim 1, further comprising: a hand driving wire that enables the hand to rotate relative to the second structure.

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