CN117897262A - Robot hand - Google Patents

Abstract

A robot hand (10) has a1 st finger (A), a2 nd finger (B), a base (20), and a drive unit (DA 1). The 1 st finger section (A) has a base link section (A1) connected to the base section (20), an intermediate link section (A2) connected to the base link section (A1), a tip link section (A3) connected to the intermediate link section (A2), a passive joint section (PA 2) rotatably supporting the base link section (A1) and the intermediate link section (A2), a passive joint section (PA 3) rotatably supporting the intermediate link section (A2) and the tip link section (A3), and a spring element (SA 2) holding the base link section (A1) and the intermediate link section (A2) in a basic posture.

Description

Robot hand

Technical Field

The present invention relates to a robot hand that grips a gripping object by gripping with 2 fingers.

Background

In order to perform a complicated task, a conventional robot hand is often constituted by a plurality of finger mechanisms having a plurality of joints and a plurality of actuators, such as human fingers. On the other hand, development of an underactuated robot hand having a small number of actuators relative to the degree of freedom of the system is also underway.

For example, in order to grasp an object whose shape or size is unknown, an underactuated robot hand that can perform a finger operation such as curling has been developed. In patent document 1, a finger assembly having a link mechanism including a proximal joint, an intermediate joint, and a distal joint is provided, and each joint is synchronously driven by a single actuator. Specifically, pulleys are provided in the joints, and the pulleys are rotated by the tension of the torsion wire wound around the pulleys, and the joints are locked and unlocked by the indirect brake mechanism, whereby various operations of the finger assembly are realized.

Patent document 1: japanese patent laid-open No. 2017-35780

Disclosure of Invention

The robot hand of patent document 1 has a problem of complicated structure. In addition, when switching from a state in which a plurality of objects to be gripped are aligned in a laminated manner to a state in which one object to be gripped is gripped stably, the robot hand of patent document 1 requires complicated control such as management of fine state switching and locking of fingers corresponding to the state. Specifically, in the case of performing an operation of cutting one object from a plurality of objects to be gripped aligned in order and then performing a sliding operation until the objects to be gripped can be wrapped in a state of being gripped, a complicated control operation for performing a complicated conversion of fingertips is required in patent document 1. Therefore, in patent document 1, it is necessary to design a control operation for each object to be gripped, and it may be difficult to generate a finger movement according to the type of the object to be gripped.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a robot hand capable of realizing a pick-up operation and a package gripping by a simple structure and a simple control which can be miniaturized.

In order to solve the above problems and achieve the object, a robot hand according to the present invention grips an object to be gripped. The robot hand is characterized by comprising: a finger portion having a 1 st finger portion and a 2 nd finger portion opposite to the 1 st finger portion; a base portion provided to an arm of the robot; and a driving unit connected to the base unit and configured to rotationally drive at least one of the 1 st finger unit and the 2 nd finger unit. The 1 st finger has: a 1 st link portion connected to the base portion; a 2 nd link portion connected to the 1 st link portion; a 3 rd link portion connected to the 2 nd link portion; a 1 st passive joint portion rotatably supporting the 1 st link portion and the 2 nd link portion; a 2 nd passive joint portion rotatably supporting the 2 nd link portion and the 3 rd link portion; and a 1 st elastic body that holds the 1 st link portion and the 2 nd link portion so as to be in a basic posture.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the robot hand of the present invention, the fishing operation and the package gripping are realized by a simple structure and a simple control which can be miniaturized.

Drawings

Fig. 1 is a conceptual diagram showing a robot system to which the robot hands of embodiments 1 to 12 are applied.

Fig. 2 is a conceptual diagram illustrating a robot hand according to embodiment 1.

Fig. 3 is a conceptual diagram showing a modification 1 of the robot hand according to embodiment 1.

Fig. 4 is a conceptual diagram showing modification 2 of the robot hand according to embodiment 1.

Fig. 5 is a diagram for explaining an operation when the robot hand according to modification 1 of embodiment 1 shown in fig. 3 grips an object to be gripped.

Fig. 6 is a conceptual diagram showing a configuration of a distal end portion of the robot hand according to embodiment 2.

Fig. 7 is a conceptual diagram showing a configuration of a modification of the distal end portion of the robot hand according to embodiment 2.

Fig. 8 is a conceptual diagram showing a configuration of a distal end portion of the robot hand according to embodiment 3.

Fig. 9 is a conceptual diagram showing the posture of the distal end portion of the robot hand according to embodiment 3 when gripping a flat gripping object placed horizontally on the ground.

Fig. 10 is a conceptual diagram showing a configuration of a distal end portion of the robot hand according to embodiment 4.

Fig. 11 is a conceptual diagram showing a state of a distal end portion when the robot hand according to embodiment 4 grips a gripping object.

Fig. 12 is a conceptual diagram showing the posture of the distal end portion of the robot hand according to embodiment 4 when gripping a flat gripping object placed horizontally on the ground.

Fig. 13 is a conceptual diagram showing a configuration of a distal end portion of a robot hand according to embodiment 5.

Fig. 14 is a conceptual diagram showing the structure of the robot hand according to embodiment 6.

Fig. 15 is an oblique view showing the structure of the robot hand according to embodiment 6.

Fig. 16 is a conceptual diagram showing the structure of the robot hand according to embodiment 7.

Fig. 17 is a conceptual diagram showing the structure of the robot hand according to embodiment 8.

Fig. 18 is a conceptual diagram showing the structure of the robot hand according to embodiment 9.

Fig. 19 is a conceptual diagram showing the structure of the robot hand according to embodiment 10.

Fig. 20 is a conceptual diagram showing the structure of the robot hand according to embodiment 10.

Fig. 21 is a conceptual diagram showing the structure of the robot hand according to embodiment 11.

Fig. 22 is a conceptual diagram showing the structure of the robot hand according to embodiment 12.

Fig. 23 is an oblique view showing the structure of the robot hand according to embodiment 12.

Detailed Description

The robot hand according to the embodiment will be described in detail below with reference to the drawings.

Fig. 1 is a conceptual diagram showing a robot system to which the robot hands according to embodiments 1 to 12 are applied. The robot system includes a robot 1, a robot hand 10, and a robot controller 2. The robot 1 has a plurality of arms 5. The robot hand 10 is connected to the front end of the arm 5 of the robot 1. The robot hand 10 is controlled by the robot controller 2 to grip the object W to be gripped.

Embodiment 1.

Fig. 2 is a conceptual diagram illustrating the robot hand 10 according to embodiment 1. As shown in fig. 2, the robot hand 10 includes: a base 20; and 1 st and 2 nd fingers a and B, which are mounted to the base 20, opposite to each other. The 1 st finger portion a has a driving portion DA1, a base end link portion A1 as A1 st link portion, a passive joint portion PA2 as A1 st passive joint portion, an intermediate link portion A2 as A2 nd link portion, a passive joint portion PA3 as A2 nd passive joint portion, a tip end link portion A3 as A3 rd link portion, and a spring element SA2 as A1 st elastic body. The 2 nd finger B has a base link portion B1. The base link B1 also functions as a tip link. The passive joint is a joint that is not driven by an actuator such as a motor.

The base 20 is, for example, cylindrical in shape, having a central axis. The driving unit DA1 is fixed to the base 20. The driving unit DA1 rotatably supports the base link portion A1, and rotatably drives the base link portion A1. The base link portion A1 is rotationally driven by the driving portion DA1 around the driving portion DA 1. The passive joint portion PA2 rotatably connects the distal end side of the base link portion A1 and the proximal end side of the intermediate link portion A2. The intermediate link portion A2 is rotationally driven about the passive joint portion PA 2. The spring element SA2 has a predetermined tension to connect the base link portion A1 and the intermediate link portion A2, and adjusts the base link portion A1 and the intermediate link portion A2 to balance at an angle θ1. That is, the spring element SA2 holds the base link portion A1 and the intermediate link portion A2 so as to be in the basic posture. θ1 is greater than or equal to 90 degrees. θ1 represents an angle on the abdominal side. The passive joint portion PA3 rotatably connects the distal end side of the intermediate link portion A2 and the proximal end side of the distal end link portion A3. The distal link portion A3 is rotationally driven around the passive joint portion PA 3. The distal link portion A3 is connected to the passive joint portion PA3, and therefore, if pushed by the environment, its posture changes. Although not shown, the distal end link portion A3 is preferably tapered to facilitate gripping of the object to be gripped. As the spring element SA2 connected to the base link portion A1 and the intermediate link portion A2, an elastic body other than a spring may be used.

The base link portion B1 is fixed to the base 20 and does not move relative to the base 20.

Fig. 3 is a conceptual diagram showing a modification 1 of the robot hand 10 according to embodiment 1. The robot hand 10 shown in fig. 3 includes: a base 20; and 1 st and 2 nd fingers a and B, which are mounted to the base 20, opposite to each other. The 1 st finger a shown in fig. 3 has the same structure as the 1 st finger a shown in fig. 2, and a repetitive description thereof is omitted.

The 2 nd finger portion B shown in fig. 3 has a base end link portion B1 as a 4 th link portion, a passive joint portion PB2 as a 3 rd passive joint portion, a tip end link portion B2 as a 5 th link portion, and a spring element SB2 as a 2 nd elastic body. The base link portion B1 is fixed to the base 20. The passive joint portion PB2 rotatably connects the distal end side of the base link portion B1 and the proximal end side of the distal link portion B2. The distal link portion B2 is rotationally driven around the passive joint portion PB 2. The spring element SB2 has a predetermined tension to connect the base link portion B1 and the tip link portion B2, and the rigidity is adjusted so that the base link portion B1 and the tip link portion B2 are balanced at the angle θ2.θ2 is greater than or equal to 90 degrees. θ2 represents an angle of the abdominal side.

As shown in fig. 3, the spring elements SA2 and SB2 are connected to apply tension in the clockwise direction around the passive joint portions PA2 and PB2, but the present invention is not limited thereto. For example, the spring elements SA2 and SB2 may be connected to apply tension in the counterclockwise direction around the passive joint portions PA2 and PB2, or may be connected to apply tension in both the clockwise and counterclockwise directions.

With the above configuration, the situation in which the width between the 1 st finger a and the 2 nd finger B is too wide to cause the object W to be gripped to fall during gripping, and the object W to be gripped is separated from between the 1 st finger a and the 2 nd finger B and cannot be gripped can be reduced.

The environment refers to the ground, the wall, or the surface of an object around the object W, in addition to the object W. That is, in the case of gripping the object W, the finger tip touch is applied to an external force when the robot 1 is moved and the robot hand 10 is moved.

Fig. 4 is a conceptual diagram showing a modification 2 of the robot hand 10 according to embodiment 1. In modification 2 shown in fig. 4, a stopper STA1 is provided in the 1 st passive joint portion PA2 of the 1 st finger portion a, and a stopper STA2 is provided in the passive joint portion PA 3. The stopper STA1 as the 1 st stopper is, for example, a plate member provided outside the distal end of the base link portion A1, and is provided to limit the movable range in the direction in which the intermediate link portion A2 expands with respect to the base link portion A1. The stopper STA2 is a plate member provided outside the distal end of the intermediate link portion A2, for example, and is provided to limit the movable range in the direction in which the distal end link portion A3 expands with respect to the intermediate link portion A2. By providing the stoppers STA1 and STA2 as described above, reaction forces F1 and F2 are generated from the object W with respect to the 1 st finger a when the object W is gripped. The stopper as described above may be provided to the passive joint portion PB2 of the 2 nd finger portion B shown in fig. 3. In addition, only either one of the stoppers STA1, STA2 may be provided in the 1 st finger a.

Fig. 5 is a diagram for explaining an operation when the robot hand 10 according to modification 1 of embodiment 1 shown in fig. 3 grips the gripping object W1. In this operation example, the one gripping object W1 is fished from the plurality of gripping objects W1, W2, W3, which are aligned so as to be bonded to each other, and then the gripping object W1 is wrapped and gripped. The thickness of the objects W1, W2, W3, & gtis small, has a flat rectangular parallelepiped shape. The plurality of objects W1, W2, W3 are placed on the floor surface Q.

First, as shown in the left view of fig. 5, the robot controller 2 moves the base 20 of the robot hand 10 by the robot 1, the distal end of the distal end link portion A3 of the 1 st finger portion a is inserted between the forefront object W1 and the 2 nd object W2 among the plurality of aligned objects W1, W2, W3, ··. The movement of the base 20 is performed by the movement of the robot 1.

In the right diagram of fig. 5, 3 operational states are shown for the 1 st finger a and 2 operational states are shown for the 2 nd finger B. Next, the robot control device 2 moves the base 20 by the robot 1, and presses the distal end link portion A3 of the 1 st finger portion a against the object W2 to be gripped at the 2 nd finger portion a as shown in the left-hand operation state of the 1 st finger portion a in the right view of fig. 5. At this time, the distal end link portion A3 is pressed in contact with the object W2 to be gripped at the 2 nd, and as indicated by an arrow E1, the rotational movement is started around the passive joint portion PA3 in the direction toward the 2 nd finger portion B side. At this time, the distal end link portion A3 passively moves by a reaction force generated by contact with the object W2 to be gripped. By this passive movement, the object W1 is rotated to separate the object W1 from the aligned rows of objects. The separation as described above is referred to as "single separation", but in embodiment 1, the structure of the tip link portion A3 for achieving single separation is characterized. The single separation operation using the tip link portion A3 has the following advantages over the case of simply pushing in the finger to perform the single separation.

That is, in the initial stage of gripping, the gap into which the finger portion enters becomes large, and the operation of gripping the object to be gripped becomes easy. In addition, the time for the finger to slide on the surface of the object W1 is reduced, and the object W1 is less likely to be damaged.

Then, as shown in the central operation state and the right operation state of the finger 1 a in the right view of fig. 5, the base end link A1 is rotated by the driving unit DA1, and the object W1 is gripped by the finger 1 a and the finger 2B to thereby grip the package. At this time, the distal end link portion B2 of the 2 nd finger portion B is pressed by the object W1 to be gripped, and the rotation movement is from the state shown by the broken line to the state shown by the solid line centering on the passive joint portion PB 2. In addition, during this gripping operation, the object W1 is slid on the ground Q by the rotational movement of the base end link portion A1. When the 1 st finger portion a is continuously closed by the driving portion DA1, the distal end link portion A3 and the intermediate link portion A2 passively move along the surface of the object W1 to be gripped.

According to the robot hand 10 of embodiment 1, it is possible to cope with the grasping operation in the case where the thin and flat grasping target object W1 shown in fig. 5 is placed horizontally on the ground surface Q. First, the robot 1 moves the base 20 of the robot hand 10, presses the rear surface side of the front link portion A3 against the ground surface Q, and rotates the front link portion A3 so as to follow the ground surface Q. Then, the base 20 is moved to bring the distal end link portion A3 closer to the object W1. Further, if the driving unit DA1 is driven to rotate in the direction to close the 1 st finger a, the flat object W1 to be gripped disposed on the ground Q can be gripped.

Next, a state in which the intermediate link portion A2 is balanced at the angle θ1 with respect to the base link portion A1 by the spring element SA2 will be described.

As shown in fig. 2, with respect to the passive joint portion PA2, even if a displacement occurs, a force that returns to the basic posture is generated by the spring element SA 2. That is, the spring element SA2 acts a restoring force that returns to the basic posture. The basic posture shows an initial posture of the robot hand 10 when the gripping operation is started for gripping the object.

As an example of a specific basic posture, as shown in fig. 5, the direction of the central axis of the base 20 of the robot hand 10 is set to be substantially parallel to the gravitational direction, and the base link portion A1, the intermediate link portion A2, and the tip link portion A3 of the 1 st finger portion a extend downward from the base 20 of the robot hand 10. However, the posture is not particularly limited as long as it is a posture in which the angle θ1 is 90 degrees or more.

The basic posture of the 1 st finger a will be described. As described above, the arm 5 of the robot 1 is moved to place the base 20 of the robot hand 10 in the basic posture state in which the direction of the central axis of the base 20 coincides with the direction of gravity. In the state where the base 20 is in the basic posture, the robot hand 10 is in the open state, the arm 5 is moved to bring the robot hand 10 into proximity with the object to be gripped, the driving unit DA1 of the robot hand 10 is driven to the closed state, and the object to be gripped is gripped. The base link portion A1 rotates in the opening direction until the attitude thereof is horizontal to the ground, and rotates in the closing direction until the state is completely closed.

When the base link portion A1 and the ground are horizontal, the intermediate link portion A2 is adjusted to coincide with the gravitational direction. The reason why the intermediate link portion A2 is aligned in the gravity direction is that many of the gaps between the plurality of gripping objects aligned in alignment so as to overlap each other are parallel or slightly inclined to the gravity direction. When the tip link portion A3 of the 1 st finger portion a of the robot hand 10 is inserted into the gap as described above, the object to be gripped can be gripped most effectively if the intermediate link portion A2 is set to substantially coincide with the gravitational direction.

As described above, the base link portion A1 is closed as compared with the horizontal direction, and the intermediate link portion A2 is oriented in the direction aligned with the gravitational direction, which is an appropriate basic posture in embodiment 1. Here, it is understood that if focusing on the angle θ1 formed by the base link portion A1 and the intermediate link portion A2, there is a basic posture in the closing direction from the state where the base link portion A1 is set to be horizontal, and if the intermediate link portion A2 is contoured in the gravitational direction, the angle θ1 is necessarily equal to or greater than 90 degrees. That is, if a constraint condition that the angle θ1 formed by the base link portion A1 and the intermediate link portion A2 is equal to or greater than 90 degrees is added, the robot hand 10 of embodiment 1 can be used under appropriate conditions.

In the robot hand 10 according to embodiment 1, if the 1 st finger a is opened after the gripping operation, the original basic posture is automatically restored by gravity. The spring element SA2 added to the passive joint PA2 is expected to have an effect of preventing displacement by generating an appropriate resistance when the object to be gripped is gripped or the intermediate link A2 is in contact with the environment, but the intermediate link A2 is not expected to be contoured by gravity in the state of the basic posture, and cannot take the downward posture due to the influence of the spring element SA 2.

That is, the spring element SA2 is preferably adjusted to be in a basic posture in a state of a natural length. The hardness of the spring element SA2 may be adjusted to an appropriate hardness when the individual objects to be gripped are separated from each other in a state where the objects to be gripped are aligned. Specifically, the hardness is adjusted to such a degree that the intermediate link portion A2 cannot be fully opened in accordance with the movement of the driving portion DA1 to close the base end link portion A1.

Here, there are a plurality of configurations as the robot 1 to which the robot hand 10 is attached. Specific examples of the mechanism of the robot 1 include a serial link mechanism and a parallel link mechanism. The serial link mechanism has a structure in which links are arranged in series in a cantilever state from a ground fixed position, and is characterized by a large movable range. The parallel link mechanism has a closed link structure, and is characterized by high rigidity and high-speed operation.

Since the movable range of the robot differs depending on the configuration of the robot 1, when the operation of the robot hand 10 described above is realized, it is considered that the movable range is narrow in the parallel link and cannot be realized depending on the system. Each of the embodiments is applicable to any mechanism in which the base 20 of the robot 1 can be moved in translation and in rotation relative to the object to be gripped. That is, the respective embodiments are not particularly limited to the configuration of the robot 1.

The driving unit DA1 is described as constituting a rotary joint, but if the rotary joint is a joint that performs a rotary motion, a driving source may be disposed at another position via a belt, not shown, for example. If the base link portion A1 can be rotated, the driving portion DA1 may be replaced with a passive joint portion, and the base link portion A1 may be pressed by the driving portion DA1 that moves linearly. That is, the base link portion A1 may be configured to be movable with respect to the base portion 20 about a rotational joint.

Further, as the passive joint PA2, the passive joint PA3, and the passive joint PB2, any bearing such as a rolling bearing, a roller bearing, or a slide bearing may be used if the bearing rotates slidably about one axis. The passive joint portions PA2, PA3, and PB2 are configured to be rotationally displaced by rotational torque based on an external force applied to each link portion and rotational friction of the bearing. In addition, the passive joint PA2, the passive joint PA3, and the passive joint PB2 may be configured such that a spring or the like is attached between the fixed portion and the rotating portion of each passive joint in order to return to the original positions during each operation.

As described above, in patent document 1, the joint portions are connected to each other by pulleys and a torsion wire, and the joint portions perform a linked motion, but embodiment 1 is not the above-described configuration. In the mechanism of patent document 1, when one object to be gripped is separated from a plurality of objects to be gripped aligned as described above, when only the link portion at the tip of the finger portion is externally applied, the operation of pulling the object to be gripped from the object disposed adjacent to the link portion as described above does not occur. In contrast, according to the robot hand 10 of embodiment 1, the passive joint portion PA3 at the distal end does not operate in conjunction with other joints, and therefore, only the passive joint portion PA3 connected to the distal end link portion A3 generates joint displacement by reaction force from the object to be gripped, and an operation of pulling the object to be gripped away from the object disposed adjacent thereto can be realized.

As described above, according to embodiment 1, since the distal-most passive joint PA3 does not operate in conjunction with other joints, a single separation operation including a stable scooping operation and a package gripping can be realized by a simple structure and a simple control that can be miniaturized, and the success rate of the single separation operation can be improved. This can improve the productivity of the automated robot system.

Embodiment 2.

Fig. 6 is a conceptual diagram showing a configuration of a distal end portion of the robot hand according to embodiment 2. In embodiment 2, a tapered finger web portion 21 is further provided at a portion of the 1 st finger portion a and the 2 nd finger portion B of embodiment 1, which portion is in contact with the object to be gripped. The finger web 21, which is the 1 st finger web, has a thicker base end side and a tapered front end side. Fig. 6 shows the tip of the 1 st finger a, and the finger web 21 is fixed to the tip of the tip link A3. The finger belly portion 21 is provided to increase the contact area with the object to be gripped, and is formed in a shape suitable for direct contact with the object to be gripped, and is made of a soft material. For example, a material having an increased friction coefficient or an antibacterial material may be selected for hygiene in contact with the object to be gripped.

Fig. 7 is a conceptual diagram showing a configuration of a modification of the distal end portion of the robot hand according to embodiment 2. In fig. 7, the distal end link portion A3' is composed of a link portion 21a and a tapered finger web portion 21b, and the link portion 21a and the finger web portion 21b are composed of the same soft material.

As described above, according to embodiment 2, since the finger web portion of a soft material is provided at the tip of the 1 st finger portion a and the 2 nd finger portion B, the gripping success rate is improved and the yield is improved.

Embodiment 3.

Fig. 8 is a conceptual diagram showing a configuration of a distal end portion of the robot hand according to embodiment 3. In embodiment 3, the shape of the tip link portion A3 of the 1 st finger portion a of embodiment 1 is changed. In the front end link portion A3 of embodiment 3, the back surface portion 22 is formed of a plane parallel to the central axis of the intermediate link portion A2. In the front end link portion A3 of embodiment 3, the back surface portion 22 is formed of a plane parallel to the direction in which the central axis of the intermediate link portion A2 extends. Further, on the finger web side of the distal end link portion A3 in embodiment 3, the proximal end portion 23 that is close to the passive joint portion PA3 has a convex portion shape that protrudes inward, i.e., toward the surface side, from the passive joint portion PA3, and the distal end portion 24 has a tapered cone shape. The base end portion 23 and the tip end portion 24 are connected not in a slope shape but in a steep step shape, and the tip end portion 24 is recessed with respect to the base end portion 23 in a convex shape.

The robot hand according to embodiment 3 is characterized in that it is capable of gripping an object to be gripped which is difficult to be taken out simply by a laterally symmetrical, thin-pointed claw-tip structure. As shown in fig. 5, the structure of the distal end link portion A3 needs to be tapered in order to perform the operation of inserting the finger between the object to be gripped and the object to be gripped. When the last object to be gripped is taken out, the shape along the wall is required in the case where the finger is inserted into the object to be gripped against the wall surface. In the robot hand according to embodiment 3, the finger is easily inserted in the above-described manner.

The operation of the robot hand in embodiment 3 will be described. The robot 1 is used to move the base 20 of the robot hand 10, and the tip link portion A3 is pushed against the environment, and as a result, the state of the tip link portion A3 along the environment is passively switched. Before starting gripping, a basic posture in which gripping is easy to succeed is obtained, and the robot hand 10 is operated in a designed gripping approaching direction.

Here, as a basic posture for gripping, a state is created in which the front end link portion A3 sags with respect to the intermediate link portion A2 due to its own weight. As shown in fig. 8, the robot hand 10 has a convex-shaped base end 23 on the web side of the distal link portion A3, and a distal end 24 that tapers toward the distal end.

The rear surface 22 of the front link portion A3 is in a state of sagging due to its own weight, and takes a shape of being parallel to the wall surface. That is, when the back surface portion 22 of the distal end link portion A3 sags due to its own weight, the fingertip and the back surface portion 22 are arranged in a substantially straight line. The abdomen side has a convex base end 23 and a tip end 24 that tapers toward the tip. By providing the convex-shaped base end portion 23 on the abdomen side, the contact surface can be increased with respect to the object to be gripped. As described above, in the robot hand according to embodiment 3, since the distal end portion 24 is formed to be tapered toward the distal end, the single separation is facilitated, and the convex-shaped proximal end portion 23 is provided on the abdomen side of the finger, so that the object to be gripped can be gripped stably.

When the robot hand according to embodiment 3 is mounted on the robot 1 and used, the robot hand is designed to have a basic posture as a fingertip of the robot hand, and an angle formed by the front end link portion A3 and the intermediate link portion A2 in a gravitational state is 180 degrees or less. For example, as shown in fig. 5, when the intermediate link portion A2 is vertical to the ground, the angle formed by the intermediate link portion A2 and the distal end link portion A3 is 180 degrees.

On the other hand, the base 20 of the robot hand may be set to a slightly inclined posture in the clockwise direction, and in this case, the intermediate link portion A2 may be set to a slightly inclined posture with respect to the ground as compared with the vertical direction. On the other hand, since the distal link portion A3 takes a substantially vertical posture with respect to the ground, the angle formed by the intermediate link portion A2 and the distal link portion A3 is slightly smaller than 180 degrees.

Fig. 9 is a conceptual diagram showing the posture of the distal end portion of the robot hand according to embodiment 3 when gripping a flat gripping object placed horizontally on the ground. As shown in fig. 9, in the case of the robot hand according to embodiment 3, the tip link portion A3 can be inserted between the flat object horizontally placed on the ground and the ground. First, the axial direction of the base 20 is set to a slightly inclined state, the intermediate link portion A2 is set to a state inclined at a right angle to the ground, and the rear surface side of the front end link portion A3 is set to a state in contact with the ground. In this state, the arm 5 of the robot 1 is moved, and the base 20 is moved in the direction of pressing against the ground. The distal link portion A3 rotates around the passive joint portion PA3 by a reaction force generated from the ground surface with the movement of the base portion 20. The robot control device 2 is controlled so that the distal end link portion A3 maintains a posture that changes due to the rotation of the passive joint portion PA3, and the 1 st finger portion a or the arm 5 of the robot 1 is moved in a direction in which the distal end link portion A3 is interposed between the object to be gripped horizontally placed on the ground and the ground. The movement in the direction of inserting the distal end link portion A3 may be any of a method of driving the 1 st finger portion a by the driving portion DA1 and a method of moving the base portion 20 by the arm 5 of the robot 1. When the front link portion A3 is moved in the direction of insertion between the ground surface and the lower surface of the object to be gripped, the front link portion A3 is restrained by the ground surface, and the front link portion A3 smoothly slides between the ground surface and the lower surface of the object to be gripped, and a state in which the front link portion A3 supports the lower surface of the object to be gripped can be switched.

When the distal end link portion A3 is inserted between the ground and the object to be gripped, if the method of driving the 1 st finger portion a by the driving portion DA1 is adopted, the intermediate link portion A2 approaches the ground along with the entire rotational movement of the 1 st finger portion a by the driving portion DA 1. At this time, the front end link portion A3 passively rotates with both the reaction force from the ground and the movement of the connection portion with the intermediate link portion A2. Thus, the rear surface portion approaching the front end link portion A3 becomes a substantially parallel posture with the ground as a passive motion. By this movement, the front end link portion A3 smoothly slides into the lower surface of the object to be gripped, and the state in which the front end link portion A3 supports the lower surface of the object to be gripped can be switched.

In the above example, the flat object to be gripped disposed on the ground has been described, but the same effect can be expected when the flat object to be gripped standing on the wall surface is gripped by being separated from the wall surface alone.

The distal end of the distal end link portion A3 is preferably concave to be tapered, but a soft material is adhered to a portion of the distal end link portion A3, which is in contact with the object to be gripped, so that the object to be gripped is less likely to fall off, and therefore, a soft member may be provided in the distal end of the distal end.

As described above, in the distal link portion A3 according to embodiment 3, the rear surface portion 22 is formed of a plane parallel to the intermediate link portion A2, and the base end portion 23 having a convex shape and the tapered distal end portion 24 are provided on the finger web side, so that the objects to be gripped that are disposed on the ground or the wall surface in a bonded manner can be smoothly separated from each other. Thereby, the production efficiency of the automated robot system is improved.

Embodiment 4.

Fig. 10 is a conceptual diagram showing a configuration of a distal end portion of the robot hand according to embodiment 4. Fig. 11 is a conceptual diagram showing a state of a distal end portion when the robot hand according to embodiment 4 grips a gripping object. The front end link portion A3 of the 1 st finger portion a of the robot hand according to embodiment 4 has a protruding portion 25 extending to the upper side than the passive joint portion PA3 and protruding to the rear side on the rear side. In other words, the distal link portion A3 of the 1 st finger portion a of the robot hand according to embodiment 4 has a protruding portion 25 that extends to the upper side than the passive joint portion PA3 and protrudes to the rear side than the passive joint portion PA3 in a state where it sags due to its own weight. The grasping portion 26 of the distal end link portion A3 grasping the object W to be grasped on the abdomen side has a bent shape, and a friction member 27 such as rubber is provided on the surface. In other words, the tip end side of the tip end link portion A3 of the 1 st finger portion a of the robot hand according to embodiment 4 from the passive joint portion PA3 is tapered, and the base end portion of the tip end side of the tip end link portion A3 from the passive joint portion PA3 protrudes to the back surface side and the front surface side.

Fig. 12 is a conceptual diagram showing the posture of the distal end portion of the robot hand according to embodiment 4 when gripping a flat gripping object placed horizontally on the ground. The left view of fig. 12 shows a state when the tip side of the tip link portion A3 is in contact with the ground (or the wall surface), and the right view of fig. 12 shows a state when the projection 25 on the root side of the tip link portion A3 is in contact with the ground (or the wall surface). As shown in the left view of fig. 12, when the tip end side of the tip end link portion A3 contacts the ground, the tip end link portion A3 rotates in the counterclockwise direction by a reaction force from the ground indicated by an arrow. On the other hand, as shown in the right view of fig. 12, when the root-side protruding portion 25 of the distal link portion A3 contacts the ground, the distal link portion A3 rotates in the clockwise direction by the reaction force from the ground indicated by the arrow. Therefore, the distal end link portion A3 can be automatically adjusted to a posture in which the distal end portion of the distal end link portion A3 easily enters between the object to be gripped and the ground (or the wall surface).

As described above, according to embodiment 4, since the protruding portion 25 that extends to the upper side than the passive joint portion PA3 and protrudes to the rear side is provided on the rear surface portion of the front end link portion A3, the front end link portion A3 can be automatically adjusted to a posture in which the front end portion of the front end link portion A3 easily enters between the object to be gripped and the ground (or the wall surface). Thus, the objects to be gripped which are disposed on the ground (or the wall surface) in a bonded manner can be smoothly separated from each other. Thereby, the production efficiency of the automated robot system is improved.

Embodiment 5.

Fig. 13 is a conceptual diagram showing a configuration of a distal end portion of a robot hand according to embodiment 5. The left diagram of fig. 13 shows the posture when the robot hand is in the initial posture, and the right diagram of fig. 13 shows the posture when a force in the gravitational direction shown by the arrow is applied to the driving unit DA1 of the robot hand. In embodiment 5, a spring element SA3 is also added to the periphery of the passive joint portion PA3 in relation to the robot hand 10 of embodiment 1. The spring element SA3 has a lower elasticity than the spring element SA2 surrounding the passive joint portion PA 2. That is, the spring is weaker as it advances toward the front end.

In this configuration, since the spring element SA3 on the tip end side is bent first and then the spring element SA2 is bendable, the behavior of the tip end link portion A3 is contoured on the wall surface or the ground surface as described above, and the tip end link portion can be restored to a constant basic posture. The spring may be mounted in any of 3 modes, that is, a case where tension is applied in a clockwise direction, a case where tension is applied in a counterclockwise direction, and a case where tension is applied from both of them around the passive joint portion PA 3.

When the same gripping operation is repeated, the tip of the tip link portion A3 may come into contact with the object to be gripped, and a desired operation of the tip may not occur, when the initial position of the tip link portion A3 performing the passive operation is changed each time, or when the tip is pressed by a shape such as a wall surface or a ground surface.

According to embodiment 5, since the spring element SA3 on the tip end side is bent first and then the spring element SA2 is bent, the operation of separating the fingertip from the wall surface or the ground surface can be performed stably each time, and the grip success rate is improved. As a result, the production efficiency of the production system can be improved.

Embodiment 6.

Fig. 14 is a conceptual diagram showing the structure of the robot hand according to embodiment 6. Fig. 15 is an oblique view showing the structure of the robot hand according to embodiment 6. Embodiment 6 further includes a robot fixing part 30 for connecting to the robot 1, and further includes a passive joint part P0 as a 4 th passive joint part between the base part 20 of the robot hand 10 and the robot fixing part 30, and a spring element S0 as a3 rd elastic body for holding the passive joint part P0 at an initial position, with respect to the robot hand 10 of embodiment 1. The initial position of the passive joint P0 is a position where the center axis of the base 20 is inclined so that the fingertip of the robot hand 10 is parallel to the gravitational direction.

In the conventional mechanism, when the fingertip of the robot hand is pressed in the shape of a wall surface or a floor surface, the wrist portion of the arm of the robot needs to be inclined with respect to the wall surface or the floor surface. In this case, the wrist portion of the arm has an inclination, and thus the elbow position of the arm is projected to the environment, and the wrist portion interferes with the environment, or the movable range is insufficient, and a state having an inclination with respect to the wall surface or the ground cannot be obtained.

By the configuration of embodiment 6, the posture of the base 20 is not significantly changed by the arm 5 of the robot 1, and when the tip link portion A3 is pushed against the ground or the wall surface as in embodiment 3, the tip end portion of the tip link portion A3 can be automatically brought into a state between the flat gripping object and the ground or the wall surface.

In particular, in the robot system, when the posture of the tip of the robot hand is changed by the operation of the robot arm, there is a possibility that the elbow of the robot arm interferes with the environment. In the configuration of embodiment 6, since the robot fixing part 30 and the passive joint part P0 are provided, the change in the posture of the arm 5 of the robot 1 can be reduced, and thus interference with the environment can be avoided, and the efficiency of the gripping operation can be improved. As a result, the production efficiency of the production system can be improved.

Embodiment 7.

Fig. 16 is a conceptual diagram showing the structure of the robot hand according to embodiment 7. In the robot hand according to embodiment 7, the 1 st finger a and the 2 nd finger B have the same structure, and the 1 st finger a and the 2 nd finger B have a laterally symmetrical structure. The 1 st finger portion a includes a 7 th passive joint portion PA1, a base end link portion A1, a passive joint portion PA2, an intermediate link portion A2, a passive joint portion PA3, a tip end link portion A3, a stopper STA1 as A2 nd stopper, a spring element SA2, and a soft friction member 27 such as rubber. The 2 nd finger portion B has a passive joint portion PB1 as an 8 th passive joint portion, a base end link portion B1 as a 6 th link portion, a passive joint portion PB2 as a 5 th passive joint portion, an intermediate link portion B2' as a 7 th link portion, a passive joint portion PB3 as a 6 th passive joint portion, a tip end link portion B3 as an 8 th link portion, a stopper STB1 as a2 nd stopper, a spring element SB2 as a 4 th elastic body, and a friction member 27.

The 1 st finger portion a of embodiment 7 replaces the driving portion DA1 of embodiment 1 with a passive joint portion PA1 having no driving mechanism. The base 20 includes a rotation driving unit D0 as a driving source and a transmission mechanism unit G0 for transmitting rotation of the rotation driving unit D0 to the passive joint units PA1 and PB 1. If the rotation driving unit D0 performs rotation driving, the passive joint units PA1 and PB1 rotate synchronously. The transmission mechanism G0 may be a gear or a combination of a timing belt and a pulley. The mechanism may be configured to be bilaterally symmetrical, and the transmission mechanism portion may transmit power to only either the 1 st finger portion a or the 2 nd finger portion B, and may be driven so as to sandwich either the 1 st finger portion a or the 2 nd finger portion B.

By adopting the configuration of embodiment 7 as described above, as in embodiment 3, when the tip link portion A3 is pressed against the ground or the wall surface, the 1 st finger portion a and the 2 nd finger portion B can each perform a single separation operation in the same manner. Therefore, when the single separation operation is performed by the 1 st finger a or the 2 nd finger B, the posture change of the robot hand for moving the position of the fingertip toward the gripping object becomes small, and the movement generated by the arm 5 of the robot 1 can be reduced. As a result, the gripping success rate and the gripping efficiency are improved, and the productivity of the system is improved.

Embodiment 8.

Fig. 17 is a conceptual diagram showing the structure of the robot hand according to embodiment 8. In the robot hand according to embodiment 8, the 1 st finger a replaces the driving unit DA1 according to embodiment 1 with a passive joint PA1 as a 10 th passive joint that does not have a driving mechanism. The 1 st finger portion a has a passive joint portion PA1, a base end link portion A1, a passive joint portion PA2, an intermediate link portion A2, a passive joint portion PA3, a tip end link portion A3, and a spring element SA1 and a spring element SA2 as 6 th elastic bodies. The spring element SA1 holds the passive joint PA1 at the initial position, and the spring element SA2 holds the passive joint PA2 at the initial position.

The 2 nd finger portion B includes a driving portion DB1 that rotationally drives the base end link portion B1, the base end link portion B1 as the 9 th link portion, the passive joint portion PB2 as the 9 th passive joint portion, the distal end link portion B2 as the 10 th link portion, and the spring element SB2 as the 5 th elastic body. In embodiment 8, all joints of the 1 st finger a are passive joints having no driving mechanism, and the 2 nd finger B is rotationally driven by the driving unit DB 1.

In the robot hand according to embodiment 8, the robot hand 10 and the object W to be gripped are brought into contact with each other by the translational movement of the base 20 of the robot hand 10 by the arm 5 of the robot 1, and a single separation operation of the object W to be gripped is performed. Then, the driving unit DB1 is driven to move the 2 nd finger B in the closing direction, whereby the single separating operation by the 1 st finger a and the gripping operation by the 1 st and 2 nd fingers a and B are simultaneously performed. This makes it possible to change the gripping object in the robot hand to the gripping completed state at a high speed as compared with the configuration of embodiment 4.

That is, in embodiment 8, the 2 nd finger B is used as a finger for performing the movement of the link using the driving unit DB1 for sandwiching the object W, and the 1 st finger a is used as a finger for performing the single separation operation on the object W, and the function is separated, whereby the operation can be switched to the operation for sandwiching the object W without waiting until the completion of the single separation operation. Therefore, according to embodiment 8, the operation time required for gripping for 1 time is shortened, and as a result, the production efficiency of the production system can be improved.

Embodiment 9.

Fig. 18 is a conceptual diagram showing the structure of the robot hand according to embodiment 9. The robot hand according to embodiment 9 has the same structure as the 1 st finger a and the 2 nd finger B as the robot hand according to embodiment 7, and the 1 st finger a and the 2 nd finger B have a bilaterally symmetrical structure. In embodiment 9, a rotary joint JT0 and a driving unit D0 are disposed instead of the rotary driving unit D0, the transmission mechanism unit G0, and the passive joint units PA1 and PB1 in embodiment 7.

The 1 st finger a of the robot hand according to embodiment 9 includes a base end link portion A1, a passive joint portion PA2, an intermediate link portion A2, a passive joint portion PA3, a tip end link portion A3, a spring element SA2, and a stopper STA1 as a 4 th stopper that restricts rotation of the intermediate link portion A2 in the opening direction. The 2 nd finger B of the robot hand according to embodiment 9 includes a base end link B1 as an 11 th link, a passive joint PB2 as an 11 th passive joint, an intermediate link B2 'as a 12 th link, a passive joint PB3 as a 12 th passive joint, a tip end link B3 as a 13 th link, a spring element SB2 as a 7 th elastic body, and a stopper STB1 as a 5 th stopper that restricts rotation of the intermediate link B2' in the opening direction.

The base end link portions A1 and B1 of the 1 st and 2 nd finger portions a and B extend from the rotary joint portion JT0 in the direction of the driving portion D0. That is, the base end link portion A1 of the 1 st finger portion a has A1 st extension portion extending in the opposite direction to the intermediate link portion A2, and the base end link portion B1 of the 2 nd finger portion B has A2 nd extension portion extending in the opposite direction to the intermediate link portion B2'. The driving unit D0 connects the 1 st extending portion of the base link portion A1 and the 2 nd extending portion of the base link portion B1, presses the 1 st extending portion and the 2 nd extending portion with the connection point as an operating point, and rotationally drives the base link portions A1 and B1 with the rotary joint portion JT0 as a fulcrum. In embodiment 9, the driving unit D0 is operated to rotationally drive the 1 st finger a and the 2 nd finger B via the rotary joint JT0 while intersecting each other on the same rotation axis. The finger operation at this time operates on the same principle as scissors.

By adopting the configuration of embodiment 9, the driving unit D0 as an actuator in the robot hand can be disposed at a position further apart from the fingertip. Further, by disposing the operating point of the driving unit D0 as an actuator in the robot hand separately from the rotary joint unit JT0, the required output can be reduced by this principle, and the output can be suppressed at the time of the selection of the actuator. Thus, a small-sized actuator with a small output of the driving unit D0 can be selected, and the thickness of the robot hand can be reduced, and the size can be reduced.

As described above, according to embodiment 9, the case where gripping is impossible due to interference with the environment can be reduced, and the average operation time required for gripping can be shortened, and as a result, the production efficiency of the production system can be improved.

Embodiment 10.

Fig. 19 is a conceptual diagram showing the structure of the robot hand according to embodiment 10. Fig. 20 is a conceptual diagram showing the structure of the robot hand according to embodiment 10. Fig. 20 shows a state in which the tip portion of the robot hand is viewed obliquely. In the robot hand according to embodiment 10, the 1 st finger a replaces the passive joint PA3 of embodiment 1 with a plurality of passive joint PA3 α, PA3 β, PA3 γ, and the tip link A3 with a plurality of tip link A3 α, A3 β, A3 γ. The plurality of passive joint portions PA3 a, PA3 β, PA3 γ are coaxially connected, and the direction of the rotation axis of the plurality of passive joint portions PA3 a, PA3 β, PA3 γ is the same as that of the passive joint portion PA 2. Specifically, the passive joint portion PA3 α is connected to the intermediate link portion A2, and the passive joint portions PA3 β and PA3 γ are connected coaxially therewith. The distal end link portions a3α, a3β, a3γ are connected to the passive joint portions PA3α, PA3β, PA3γ, respectively. The base end sides of the distal link portions a3α, a3β, a3γ are thick, and have finger web portions formed in a shape tapered toward the distal end sides.

According to the configuration of embodiment 10, since the plurality of distal end link portions a3α, a3β, and a3γ are provided, in a case where the operation of inserting the finger into the object to be gripped is performed in a single separation operation of the object to be gripped, the finger is easy to be inserted compared with a case where the number of distal end link portions of the 1 st finger portion a is 1. In the embodiment in which the number of distal end link portions is 1, if there are irregularities in the shape of the object to be gripped, it is difficult to smoothly insert the finger tips. In particular, when there are irregularities such as food and fluctuations in the respective shapes, the distal end link portion has a plurality of links that can smoothly slide the finger between the object to be gripped and the object to be gripped. The reason for this is that the respective fingers are independently operated while being contoured on the surface of the object to be gripped, and thus the distal ends of the distal end link portions are contoured on the shape of the object to be gripped, respectively, and the distal end link portions a3α, a3β, a3γ are brought into a reliably contact state. As described above, the posture of the 1 st finger is switched and the single separating operation can be smoothly switched, and the contact surface is increased, whereby stable gripping can be realized.

In embodiment 10, the number of the distal end link portions is not limited to 3, and any number may be used as long as it is 2 or more. In addition, embodiment 10 is applicable to the case where the 2 nd finger B is driven by the driving unit DB1 as in the configuration of embodiment 8 shown in fig. 17, and the case where the 2 nd finger B has the base end link portion, the intermediate link portion, and the tip link portion as in the 1 st finger a shown in fig. 19 and 20. When embodiment 10 is applied, the 2 nd finger portion B has a base end link portion as a 14 th link portion, an intermediate link portion as a 15 th link portion, a tip link portion as a 16 th link portion, a passive joint portion as a 13 th passive joint portion connecting the base end link portion and the intermediate link portion, a spring element as an 8 th elastic body connecting the passive joint portion as a 14 th passive joint portion and the tip link portion and connecting the base end link portion and the intermediate link portion, and a finger web portion having a shape that is thicker on the base end side and thinner toward the tip end side of the tip link portion. The plurality of distal link portions having the abdomen portion are provided, the plurality of passive joint portions connecting the distal link portions are provided, and the plurality of passive joint portions are coaxially connected. Embodiment 10 may be applied to at least one of the 1 st finger a and the 2 nd finger B of embodiment 7 shown in fig. 16 or embodiment 9 shown in fig. 18.

As described above, according to embodiment 10, since the number of the distal end link portions is plural, the gripping success rate and the gripping efficiency are improved, and the productivity of the system is improved.

Embodiment 11.

Fig. 21 is a conceptual diagram showing the structure of the robot hand according to embodiment 11. In embodiment 11, a spring element SA2 attached to a passive joint PA2 of a 1 st finger a and a spring element SB2 attached to a passive joint PB2 of a2 nd finger B in the robot hand of embodiment 7 shown in fig. 16 are removed, and the whole robot hand is covered with a covering member 40 having elasticity. Embodiment 11 is suitable for a case where a task is not intended to be performed in direct contact with the object to be gripped by the robot hand.

Here, since the robot hand according to embodiment 11 has a passive link fingertip, the strength of the elasticity of the covering member 40 needs to be selected in order to perform displacement in the rotational direction by a displacement amount that is desired to be displaced. That is, when the robot hand is pressed to the environment, the passive joint portions PA2 and PA3 need to be passively moved to displace the link portions. When the initial angle of the passive joint portion PA2 is θa2 and the initial angle of the passive joint portion PA3 is θa3, the driving ranges of the passive joint portions PA2 and PA3 are defined as θa2min, θa2max, θa3min, θa3, and θa3max. The predetermined driving range is achieved by providing a part of the elastic covering member 40 with the slack portion 40b and the thin portion 40 a.

For having slack, the following is described. The link portions connected to the passive joint portions PA2 and PA3 include a contact side with the environment and a gripping side for gripping the object to be gripped, but the slack portion 40b is formed in the outer portions of the passive joint portions PA2 and PA3 that are in contact with the environment. The same process is also performed in the 2 nd finger B. The thin portion 40a is provided at a position symmetrical to the passive joint portions PA2 and PA3 from a position having the slack portion 40b. Accordingly, when the 1 st finger a or the 2 nd finger B is brought into contact with the environment, it is easy to bend inward. Further, since the elastic coating member 40 covers the object to be gripped, if the object to be gripped is released after the object to be gripped is gripped with respect to the environment, that is, if the force acting with respect to the hand is released, the entire object tries to return to the equilibrium position, and even if the spring elements SA2 and SB2 are not present in the passive joint portion, the 1 st finger a and the 2 nd finger B can return to the original positions.

Further, as the elastic coating member 40, a material of a glove used in a food production site can be exemplified. Specifically, nitrile rubber, natural rubber, latex, etc. exist, but the material is not particularly limited. Further, although the elastic member such as polyethylene is not elastic, a sanitary and inexpensive member may be selected, and the elastic member may be bonded to the passive joint portion from the inside only to provide the joint with elasticity. With this structure, the joint has an appropriate slack portion suitable for rotation, and a force for restoring to the original position can be applied.

As described above, according to embodiment 11, a robot hand having a glove that is sanitary and disposable can be provided, and from the viewpoint of suppressing the cost for maintenance, the production efficiency can be improved. In embodiments 1 to 11, the spring element SA2 attached to the passive joint PA2 of the 1 st finger portion a, the spring element SA3 attached to the passive joint PA3, and the spring element SB2 attached to the passive joint PB2 of the 2 nd finger portion B are removed, and the elastic coating member 40 having the slack portion 40B and the thin-walled portion 40a is covered with the robot hand, whereby the functions of the respective spring elements can be realized. The coating member 40 may cover at least a part of the base link portion, a part of the intermediate link portion, and the passive joint portion PA 2.

Embodiment 12.

Fig. 22 is a conceptual diagram showing the structure of the robot hand according to embodiment 12. Fig. 23 is an oblique view showing the structure of the robot hand according to embodiment 12. In embodiment 12, the stopper STA1 of the robot hand 10 according to embodiment 1 is replaced with a stopper STA3 having a mechanism in which the position of the intermediate link portion A2 is restricted to be variable in the rotational direction. As shown in fig. 23, the stopper STA3 is constituted by a convex portion 50 formed at the base end portion of the intermediate link portion A2, a long hole 51 formed at the tip end portion of the base end link portion A1, and a pin 52 fixed to the base end link portion A1. The pin 52 is fixed to the base link portion A1, and penetrates the long hole 51. The pin 52 can be fixed at an arbitrary position in the long hole 51. By changing the fixing position of the pin 52, the rotation angle of the intermediate link portion A2 when the pin 52 contacts the convex portion 50 can be changed. Thereby, the position of the intermediate link portion A2 can be made variable.

As described above, according to embodiment 12, since the stopper STA3 having the mechanism that changes the position in which the direction in which the intermediate link portion A2 opens is restricted in the rotational direction is provided, the state in which the external force is applied to the passive joint portion PA2, that is, the posture when the intermediate link portion A2 is fully closed is changed. Therefore, the robot hand can grasp various objects with a finger posture that is easy to grasp by changing the grasping completion posture. Thus, the gripping object of a larger variety can be gripped by the same mechanism and structure.

The configuration shown in the above embodiment represents a part of the content of the present invention, and may be combined with other known techniques, and may be appropriately combined, or a part of the configuration may be omitted or changed without departing from the scope of the present invention.

Description of the reference numerals

A robot, A2-arm, a 10-robot hand, 20 base portions, 21B refer to abdomen portions, 22 back portions, 23 base portions, 24 tip portions, 25 projecting portions, 26 gripping portions, 27 friction members, 30 robot fixing portions, 40 sheathing members, 40a thin wall portions, 40B slack portions, 50 projecting portions, 51 elongated holes, 52 pins, A1 st finger portions, A1, B1 base end link portions, A2, B2 'intermediate link portions, A3', a3α, a3β, a3γ, B2, B3 tip link portions, B2 nd finger portions, D0, DA1, DB1 driving portions (rotation driving portions), G0 transmission mechanism portions, JT0 rotation joint portions, P0, PA2, PA3, PB1, PB2, PA3 α, PA3 β, PA3 γ passive joint portions, Q ground, S0, SA1, SA2, SA3, SB1, SB2 spring elements, STA1, STA2, STA1, W2, and a stopper STA1, W2.

Claims (19)

1. A robot hand for gripping an object to be gripped,

the robot hand is characterized in that,

the device comprises:

a finger having a 1 st finger and a 2 nd finger opposite the 1 st finger;

a base portion provided to an arm of the robot; and

a driving unit connected to the base unit and configured to rotationally drive at least one of the 1 st finger unit and the 2 nd finger unit,

the 1 st finger has:

a 1 st link portion connected to the base portion;

a 2 nd link portion connected to the 1 st link portion;

a 3 rd link portion connected to the 2 nd link portion;

a 1 st passive joint portion rotatably supporting the 1 st link portion and the 2 nd link portion;

a 2 nd passive joint portion rotatably supporting the 2 nd link portion and the 3 rd link portion; and

and a 1 st elastic body that holds the 1 st link portion and the 2 nd link portion so as to be in a basic posture.

2. The robot hand according to claim 1, wherein the robot hand comprises,

the driving unit rotationally drives the 1 st link portion of the 1 st finger portion.

3. The robot hand according to claim 2, wherein,

the 2 nd finger has:

A 4 th link portion connected to the base portion;

a 5 th link portion connected to the 4 th link portion;

a 3 rd passive joint portion rotatably supporting the 4 th link portion and the 5 th link portion; and

and a 2 nd elastic body that holds the 4 th link portion and the 5 th link portion so as to be in a basic posture.

4. The robot hand according to claim 2, wherein,

the rigidity of the 1 st elastic body is set so that the 1 st link portion is closed as compared with the horizontal direction, and the 2 nd link portion is set to the basic posture in a state of matching the gravity direction.

5. A robot hand according to claim 2 or 3, characterized in that,

a1 st stopper is provided, and the 1 st stopper restricts rotation of at least the 2 nd link portion in an opening direction among the 2 nd link portion and the 3 rd link portion.

6. The robot hand according to any one of claims 2 to 4, characterized in that,

the 3 rd link portion has a 1 st web portion having a thicker base end side and a tapered tip end side.

7. The robot hand according to any one of claims 2 to 4, characterized in that,

the 3 rd connecting rod part is provided with a back surface part and a finger belly part,

The back surface portion has a plane parallel to a central axis of the 2 nd link portion,

the base end side of the finger web portion has a convex shape protruding toward the front surface side, and the tip end side of the finger web portion has a tapered shape.

8. The robot hand according to any one of claims 2 to 4, characterized in that,

the 3 rd link portion has a protruding portion that extends to the upper side of the 2 nd passive joint portion and protrudes to the rear side of the 2 nd passive joint portion in a state where the 3 rd link portion sags due to its own weight.

9. The robot hand according to claim 8, wherein the robot hand comprises,

the 3 rd link part has a tapered shape at the front end side from the 2 nd passive joint part,

the 3 rd link portion has a base end portion on a distal end side from the 2 nd passive joint portion protruding toward a rear surface side and a front surface side.

10. The robot hand according to any one of claims 2 to 9, characterized in that,

and a 3 rd elastic body having a smaller rigidity than the 1 st elastic body, and holding the 2 nd link portion and the 3 rd link portion in a basic posture.

11. The robot hand according to any of the claims 2 to 10, characterized in that,

The device also comprises:

a robot fixing unit fixed to the arm of the robot;

a 4 th passive joint portion rotatably supporting the robot fixing portion and the base portion; and

and a 3 rd elastic body that holds the robot fixing unit and the base unit in a basic posture.

12. The robot hand according to claim 1, wherein the robot hand comprises,

the 1 st finger portion further has a 2 nd stopper which restricts rotation of the 2 nd link portion in an opening direction,

the 2 nd finger has:

a 6 th link portion connected to the base portion;

a 7 th link portion connected to the 6 th link portion;

an 8 th link portion connected to the 7 th link portion;

a 5 th passive joint portion rotatably supporting the 6 th link portion and the 7 th link portion;

a 6 th passive joint portion rotatably supporting the 7 th link portion and the 8 th link portion;

a 4 th elastic body that holds the 6 th link portion and the 7 th link portion so as to be in a basic posture; and

a 3 rd stopper which restricts rotation of the 7 th link portion in an opening direction,

the 1 st finger portion has a 7 th passive joint portion rotatably supporting the 1 st link portion with respect to the base portion,

The 2 nd finger portion has an 8 th passive joint portion rotatably supporting the 6 th link portion with respect to the base portion,

the driving unit rotationally drives the 7 th passive joint unit and the 8 th passive joint unit.

13. The robot hand according to claim 1, wherein the robot hand comprises,

the 2 nd finger has:

a 9 th link portion connected to the base portion;

a 10 th link portion connected to the 9 th link portion;

a 9 th passive joint portion rotatably supporting the 9 th link portion and the 10 th link portion; and

a 5 th elastic body that holds the 9 th link portion and the 10 th link portion so as to be in a basic posture,

the driving part drives the 9 th connecting rod part of the 2 nd finger part to rotate,

the 1 st finger has:

a 10 th passive joint portion that rotatably supports the 1 st link portion with respect to the base portion; and

and a 6 th elastic body that holds the base portion and the 1 st link portion so as to be in a basic posture.

14. The robot hand according to claim 1, wherein the robot hand comprises,

the 1 st finger portion further has a 4 th stopper which restricts rotation of the 2 nd link portion in the opening direction,

The 2 nd finger has:

an 11 th link portion connected to the base portion;

a 12 th link portion connected to the 11 th link portion;

a 13 th link portion connected to the 12 th link portion;

an 11 th passive joint portion rotatably supporting the 11 th link portion and the 12 th link portion;

a 12 th passive joint portion rotatably supporting the 12 th link portion and the 13 th link portion;

a 7 th elastic body that holds the 11 th link portion and the 12 th link portion so as to be in a basic posture; and

a 5 th stopper which restricts rotation of the 11 th link portion in an opening direction,

the base portion has a rotary joint portion that rotatably supports the 1 st link portion and the 11 th link portion of the 1 st finger portion so as to intersect with the 11 th link portion of the 2 nd finger portion,

the 1 st link portion has a 1 st extension portion extending in a direction opposite to the 2 nd link portion,

the 11 th link portion has a 2 nd extension portion extending in a direction opposite to the 12 th link portion,

the driving unit presses the 1 st extending portion and the 2 nd extending portion, and rotates the 1 st link portion and the 11 th link portion about the rotation joint portion as a fulcrum.

15. The robot hand according to claim 6, wherein the robot hand comprises,

the number of the 3 rd connecting rod parts is plural,

the number of the 2 nd passive joint parts is a plurality,

the 1 st refers to a plurality of abdomen parts,

a plurality of the 2 nd passive joints are coaxially connected.

16. The robot hand according to claim 1, wherein the robot hand comprises,

the 2 nd finger has:

a 14 th link portion connected to the base portion;

a 15 th link portion connected to the 14 th link portion;

a 16 th link portion connected to the 15 th link portion;

a 13 th passive joint portion rotatably supporting the 14 th link portion and the 15 th link portion;

a 14 th passive joint portion rotatably supporting the 15 th link portion and the 16 th link portion; and

an 8 th elastic body which holds the 14 th link portion and the 15 th link portion so as to be in a basic posture,

the driving part drives the 14 th connecting rod part of the 2 nd finger part to rotate,

the 16 th link portion has a 2 nd web portion having a thicker base end side and a tapered shape toward a distal end side,

the number of the 16 th connecting rod parts is plural,

the 14 th passive joint part is provided with a plurality of parts,

the number of the 2 nd abdomen parts is a plurality,

A plurality of the 14 th passive joints are coaxially connected.

17. The robot hand according to any of claims 1 to 16, characterized in that,

the 1 st elastic body is an elastic coating member that covers at least a part of the 1 st link portion, a part of the 2 nd link portion, and the 1 st passive joint portion.

18. The robotic hand of claim 17, wherein the robotic hand comprises,

the coating member has a slack portion on the outer side of the 1 st passive joint portion and a thin portion on the inner side of the 1 st passive joint portion.

19. The robot hand according to claim 5, wherein,

the 1 st stopper has a mechanism that changes a position at which the 2 nd link portion is restricted in a rotational direction.