JP2014233807A - Robot hand, gripping method of robot hand and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot hand, a gripping method of a robot hand and a robot in which an installation number of force sensors can be reduced as far as possible and plural objects to be gripped can be held certainly by a desirable force.SOLUTION: A robot hand 10 comprises a first holding member 5 which is tabular, a second holding member 6 which is arranged at the outer peripheral side of the first holding member 5 and is tabular, a third holding member 7 which is arranged at the outer peripheral side of the first holding member 5 and the opposite side to the second holding member 6, and is tabular, and a support mechanism 8 which supports the first holding member 5 and the second holding member 6 as capable of approaching and separating and supports the first holding member 5 and the third holding member 7 as capable of approaching and separating. The first holding member 5 includes a distortion sensor 52 which detects the own distortion of the first holding member 5.

Description

  The present invention relates to a robot hand, a method for gripping a robot hand, and a robot.

  Conventionally, a robot hand having a work chuck mechanism for gripping a work is known (for example, see Patent Document 1). The work chuck mechanism has a plurality of sandwiching pieces and is configured to sandwich the work between the sandwiching pieces. In such a conventional work chuck mechanism, a force sensor is usually arranged for each clamping piece. This force sensor detects the force applied to the corresponding clamping piece, and the detection result is used to determine whether or not the clamping force for the workpiece is appropriate.

JP-A-8-52682

However, in this work chuck mechanism, force sensors are usually arranged for each sandwich piece, and therefore force sensors are required as many as the number of sandwich pieces installed. The manufacturing cost of a hand will become high. There is also a problem that the more force sensors, the more complicated the structure and control of the robot hand.
An object of the present invention is to provide a robot hand, a robot hand gripping method, and a robot that can reduce the number of installed force sensors as much as possible and can securely hold a plurality of objects to be gripped with a desired force. It is in.

Such an object is achieved by the present invention described below.
(Application example 1)
The robot hand of the present invention includes a strain sensor that detects strain,
A first clamping part connected to one end of the strain sensor;
A second clamping part movable in a moving direction approaching or separating from the first clamping part;
A third sandwiching portion disposed at a position sandwiching the first sandwiching portion together with the second sandwiching portion and movable in the moving direction;
A holding portion that connects the other end of the strain sensor to hold the first holding portion and holds the second holding portion and the third holding portion and moves the holding portion in the moving direction. The object to be grasped is gripped between the first sandwiching part and the second sandwiching part or between the first sandwiching part and the third sandwiching part.
Thereby, the number of installed force sensors can be reduced as much as possible, and a plurality of objects to be grasped can be reliably clamped with a desired force.

(Application example 2)
In the robot hand of the present invention, it is preferable that the strain sensor detects a strain in the moving direction.
Thereby, it is possible to grasp the force generated when the object is held.
(Application example 3)
In the robot hand of the present invention, at least one of the first clamping unit, the second clamping unit, and the third clamping unit includes a frame body held by the holding unit, and an edge of the frame body. It is preferable to include an elastic film that fixes the portion and has elasticity.
Thereby, when the object to be grasped is sandwiched, the contact area between the object to be grasped and the elastic film is increased, and the object can be prevented from slipping unintentionally.

(Application example 4)
In the robot hand of the present invention, it is preferable that at least one of the first clamping unit, the second clamping unit, and the third clamping unit has a free end branched in a rake shape.
Thereby, many (three or more) to-be-held objects can be clamped with desired force collectively.

(Application example 5)
In the robot hand of the present invention, a plurality of different moving directions are crossed with the first holding portion as an intersection, and the second holding member and the third holding member are arranged in each of the different directions of movement. It is preferable.
Thereby, many (three or more) to-be-held objects can be clamped with desired force collectively.

(Application example 6)
A gripping method for a robot hand according to the present invention is a gripping method for a robot hand including a first sandwiching portion, a second sandwiching portion, and a third sandwiching portion,
Sandwiching a first object to be gripped between the first sandwiching portion provided with a strain sensor for detecting strain and the second sandwiching portion movable in a moving direction approaching or separating from the first sandwiching portion; Next, a second object to be grasped is sandwiched between the first sandwiching portion and the second sandwiching portion and the third sandwiching portion which is disposed at a position sandwiching the first sandwiching portion and movable in the moving direction. It is characterized by doing.
Thereby, the number of installed force sensors can be reduced as much as possible, and a plurality of objects to be grasped can be reliably clamped with a desired force.

(Application example 7)
In the gripping method of the robot hand of the present invention, the strain that increases when the first object to be grasped is detected, the movement of the second sandwiching portion is stopped, and then the first object to be grasped is detected. It is preferable to stop the movement of the third gripping portion by detecting the distortion that decreases when the second object to be gripped is sandwiched.
Thus, the clamping operation can be performed while sequentially confirming that the object to be grasped is securely clamped.

(Application example 8)
The robot of the present invention includes the robot hand of the present invention,
The robot hand includes at least one robot arm that is detachably attached to a tip.
Thereby, the number of installed force sensors can be reduced as much as possible, and a plurality of objects to be grasped can be reliably clamped with a desired force.

It is the top view which looked at the operating state of the robot with which the robot hand concerning the present invention (the 1st embodiment) was equipped from the perpendicular upper part. It is the perspective view which looked at the robot shown in FIG. 1 from the front side. It is the schematic of the robot shown in FIG. It is a block diagram of the principal part of the robot shown in FIG. It is a side view which shows the operation state (process until it hold | grips a workpiece | work) of the robot hand shown in FIG. It is a perspective view which shows 2nd Embodiment of the robot hand concerning this invention. It is a perspective view which shows 3rd Embodiment of the robot hand concerning this invention. It is the figure (plan view) seen from the arrow A direction in FIG. It is a top view which shows 4th Embodiment of the robot hand concerning this invention. It is a side view which shows 5th Embodiment of the robot hand concerning this invention. It is the figure seen from the arrow B direction in FIG. It is CC sectional view taken on the line in FIG. It is a side view which shows 6th Embodiment of the robot hand concerning this invention. It is a front view of the robot (7th Embodiment) concerning this invention.

Hereinafter, a robot hand, a robot hand gripping method, and a robot of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
FIG. 1 is a plan view of an operating state of a robot equipped with a robot hand (first embodiment) according to the present invention as viewed from above. FIG. 2 is a perspective view of the robot shown in FIG. 3 is a schematic diagram of the robot shown in FIG. 1, FIG. 4 is a block diagram of the main part of the robot shown in FIG. 1, and FIG. 5 is an operation state of the robot hand shown in FIG. It is a side view which shows a process. In the following, for convenience of explanation, the upper side of FIG. 2, FIG. 3, FIG. 5 (the same applies to FIG. 6, FIG. 7, FIG. 10, FIG. 11, FIG. 13, FIG. 14) ", The lower side is called" lower "or" lower ". Further, the base side of the robot is called “base end”, and the opposite side is called “tip”.

  A robot 1 shown in FIG. 1 includes a robot hand 10 that is detachably mounted. The robot 1 is electrically connected to a power source (not shown) that supplies power, and a first work (first object to be grasped) 701 and a second work (second object to be grasped) 702 are connected. It can be used in a transporting process. The first work 701 and the second work 702 are not particularly limited, and for example, a sphere having relatively high rigidity (hard) is given as an example in the present embodiment. Moreover, the said power supply is an industrial power supply, for example, can apply the alternating voltage of 200V.

  The robot 1 includes a base 11, four arms (links) 12, 13, 14, 15, and a wrist (link) 16, and a vertical articulated (6-axis) robot arm in which these are sequentially connected. It is. In the vertical articulated robot, the base 11, the arms 12 to 15, and the list 16 can be collectively referred to as an “arm”. The base 11 is a “first arm”, and the arm 12 is a “first”. 2 arms ", arm 13 as" third arm ", arm 14 as" fourth arm ", arm 15 as" fifth arm ", and list 16 as" sixth arm ".

As shown in FIG. 3, the arms 12 to 15 and the wrist 16 are supported so as to be independently displaceable with respect to the base 11.
The base 11 and the arm 12 are connected via a joint 171. Then, the arm 12 with respect to base 11, and can rotate in a vertical direction parallel to the rotation axis O ₁ around. The rotation about the rotation axis O ₁ is performed by driving the motor 401. The driving of the motor 401 is controlled by a motor driver 301 that is electrically connected to the motor 401 via a cable (not shown) (see FIG. 4).

The arm 12 and the arm 13 are connected via a joint 172. Then, the arm 13 relative to arm 12 (base 11), and is rotatable in a direction parallel to the horizontal rotation axis O ₂ around. The rotation about the rotation axis O ₂ is performed by driving the motor 402. The driving of the motor 402 is controlled by a motor driver 302 that is electrically connected to the motor 402 via a cable (not shown) (see FIG. 4).

The arm 13 and the arm 14 are connected via a joint 173. Then, the arm 14 relative to arm 13 (base 11), and is rotatable in a direction parallel to the horizontal rotation axis O ₃ around. The rotation about the rotation axis O ₃ is performed by driving the motor 403. The driving of the motor 403 is controlled by a motor driver 303 electrically connected to the motor 403 via a cable (not shown) (see FIG. 4).

The arm 14 and the arm 15 are connected via a joint 174. Then, the arm 15 relative to arm 14 (base 11), and can rotate around axis parallel to rotation axis O ₄ around the arm 14. The rotation about the rotation axis O ₄ is performed by driving the motor 404. The driving of the motor 404 is controlled by a motor driver 304 that is electrically connected to the motor 404 via a cable (not shown) (see FIG. 4).

The arm 15 and the wrist 16 are connected via a joint 175. Then, the list 16, the arm 15 with respect to (the base 11), and can rotate in a horizontal direction (y-axis direction) parallel to rotation axis _{O 5} around. The rotation about the rotation axis O ₅ is performed by driving the motor 405. The driving of the motor 405 is controlled by a motor driver 305 electrically connected to the motor 405 via a cable (not shown) (see FIG. 4). The wrist 16 can also be rotated around a rotation axis O ₆ perpendicular to the rotation axis O ₅ via a joint (joint) 176. The rotation about the rotation axis O ₆ is performed by driving the motor 406. The driving of the motor 406 is controlled by a motor driver 306 electrically connected to the motor 406 via a cable (not shown) (see FIG. 4).
The motors 401 to 406 are not particularly limited, and for example, a servo motor is preferably used. The cables are inserted through the robot 1.

  As shown in FIG. 4, the robot 1 is electrically connected to a personal computer (PC) 20 having a built-in CPU (Central Processing Unit) as control means. The personal computer 20 can operate the arms 12 to 15 and the wrist 16 independently, that is, the motors 401 to 406 can be controlled independently via the motor drivers 301 to 306. . This control program is stored in advance in a recording medium built in the personal computer 20.

As shown in FIG. 2, when the robot 1 is a vertical articulated robot, the base 11 is a portion that is positioned at the lowest position of the vertical articulated robot and is fixed to the floor 101. The fixing method is not particularly limited. For example, in the present embodiment shown in FIG. 2, a fixing method using a plurality of bolts 111 is used.
The base 11 has a hollow base body (housing) 112. The base body 112 can be divided into a cylindrical portion 113 having a cylindrical shape and a box-like portion (not shown) having a box shape formed integrally with the outer peripheral portion of the cylindrical portion 113. . In such a base body 112, for example, a motor 401 and motor drivers 301 to 306 are accommodated.

  Each of the arms 12 to 15 has a hollow arm main body 2, a drive mechanism 3, and a sealing means 4, and is disposed on the base 11, i.e., disposed on the entire robot 1, and others. The configuration is almost the same except that the outer shape is different. Hereinafter, for convenience of explanation, the arm body 2, the drive mechanism 3, and the sealing means 4 included in the arm 12 are referred to as “arm body 2 a”, “drive mechanism 3 a”, and “sealing means 4 a”, respectively. The arm body 2, the drive mechanism 3, and the sealing means 4 included in the arm 13 are referred to as “arm body 2 b”, “drive mechanism 3 b”, and “sealing means 4 b”, respectively. The sealing means 4 are referred to as “arm body 2 c”, “drive mechanism 3 c”, and “sealing means 4 c”, respectively. , “Drive mechanism 3d” and “sealing means 4d”.

The arm 12 is connected to the upper end portion (tip portion) of the base 11 in a posture inclined with respect to the horizontal direction. In this arm 12, the drive mechanism 3a has a motor 402 and is housed in the arm body 2a. The arm body 2a is hermetically sealed by the sealing means 4a.
The arm 13 is connected to the tip of the arm 12. In this arm 13, the drive mechanism 3b has a motor 403 and is housed in the arm body 2b. The arm body 2a is hermetically sealed by a sealing means 4b.

The arm 14 is connected to the tip of the arm 13. In this arm 14, the drive mechanism 3c has a motor 404 and is accommodated in the arm main body 2c. Further, the inside of the arm main body 2c is hermetically sealed by the sealing means 4c.
The arm 15 is connected to the tip of the arm 14 in parallel with the central axis direction. In this arm 15, the drive mechanism 3d has motors 405 and 406, and is housed in the arm body 2d. The arm body 2d is hermetically sealed by the sealing means 4d.

  A wrist 16 is connected to the tip of the arm 15 (the end opposite to the base 11). The robot hand 10 is detachably attached to the list 16. The robot 1 controls the operations of the arms 12 to 15, the wrist 16, and the like while holding the first work 701 and the second work 702 with the robot hand 10 attached to the wrist 16. 701 and the second work 702 can be transported together.

As shown in FIG. 2, the wrist 16 includes a wrist body (mounting portion) 161 that has a cylindrical shape (the outer shape is a column), and a wrist body 161 that is separate from the wrist body 161, and a base end of the wrist body 161. And a support ring 162 having a ring shape.
The robot hand 10 is attached to the wrist main body 161. Also, list body 161 is coupled to the drive mechanism 3d of the arm 15, by the driving of the motor 406 of the driving mechanism 3d, rotates rotation axis _{O 6} around.

The support ring 162 is coupled to the drive mechanism 3d of the arm 15, by the driving of the motor 405 of the driving mechanism 3d, it rotates listwise body 161 rotation axis _{O 5} around. The support ring 162 is sandwiched between the cylindrical parts 50a and 50b. As a result, the wrist 16 can be reliably pivotably supported with respect to the arm 15.
The drive mechanisms 3a to 3d each have, for example, a pulley and a timing belt in addition to the motor.
Moreover, the sealing means 4a-4d can be set as the thing which has a plate-shaped cover and packing, respectively, for example.

  As shown in FIG. 1, the robot hand 10 is used while being attached to the list 16 of the robot 1. Hereinafter, this state is referred to as “wearing state”. In this mounted state, the robot hand 10 is electrically connected to the power source via a connector 165 provided on the front end surface 163 of the wrist 16 of the robot 1 at a connector (not shown). As a result, the support mechanism 8 of the robot hand 10 can operate by being supplied with electric power.

As shown in FIG. 5, the robot hand 10 includes a first clamping member 5, a second clamping member 6, a third clamping member 7, and a support mechanism 8.
The support mechanism 8 is a part that is attached to the wrist 16, and is a first mechanism that supports the first clamping member (first clamping part) 5 and the second clamping member (second clamping part) 6 so that they can approach and separate. 81, a second mechanism 82 that supports the first clamping member 5 and the third clamping member (third clamping part) 7 so as to be able to approach and separate, and a housing that houses the first mechanism 81 and the second mechanism 82. 83.

In the support mechanism 8, the first holding member 5 is fixedly supported, the second holding member 6 is supported movably through the first mechanism 81, and the third holding member 7 is connected through the second mechanism 82. It is supported movably.
The first mechanism 81 has, for example, a motor, a pulley, and a timing belt (all not shown), and the rotational force of the motor is transmitted to the second clamping member 6 via the pulley and the timing belt. Thereby, the 2nd clamping member 6 can move to the moving direction which approaches or leaves | separates reliably with respect to the 1st clamping member 5, can hold | grip the 1st workpiece | work 701 when approached, and when separated The first work 701 held between the two can be released.

  Similarly, the second mechanism 82 also has, for example, a motor, a pulley, and a timing belt (all not shown), and the rotational force of the motor is transmitted to the third clamping member 7 via the pulley and the timing belt. . Thereby, the 3rd clamping member 7 can move to the moving direction which approaches or leaves | separates reliably with respect to the 1st clamping member 5, can hold | grip the 2nd workpiece | work 702 when approached, and when separated The second work 702 that has been sandwiched between the two can be released.

By having the first mechanism 81 and the second mechanism 82 as described above, the second clamping member 6 and the third clamping member 7 can be supported independently and movable. As a result, the timing at which the first workpiece 701 is clamped between the first clamping member 5 and the second clamping member 6 and the second workpiece 702 is clamped between the first clamping member 5 and the third clamping member 7. A time difference can be given to the timing. That is, it is different from the clamping to the first workpiece 701 between the first clamping member 5 and the second clamping member 6 and the clamping to the second workpiece 702 between the first clamping member 5 and the third clamping member 7. This can be done at the timing (with the timing shifted).
The first clamping member 5 has a clamping member main body 51 composed of a plate-shaped (or columnar) member, and is cantilevered by the support mechanism 8 at its base end 511 (base end side). . The first clamping member 5 includes a strain sensor (strain gauge) 52 fixed (connected) to the clamping member main body 51.

The 2nd clamping member 6 is comprised by the member which makes plate shape (or column shape), and is cantilever supported by the 1st mechanism 81 by the base end part 61 (base end side). The second clamping member 6 is disposed opposite to the left surface 512 (outer peripheral side) of the clamping member main body 51 in FIG.
The 3rd clamping member 7 is comprised by the member which makes plate shape (or column shape), and is cantilevered by the 2nd mechanism 82 by the base end part 71 (base end side). The third sandwiching member 7 is disposed at a position sandwiching the first sandwiching member 5 together with the second sandwiching member 6, that is, facing the right surface 513 (outer peripheral side) of the sandwiching member main body 51 in FIG. Has been placed.

The constituent materials of the first clamping member 5, the second clamping member 6, and the third clamping member 7 are not particularly limited, and for example, various metal materials such as stainless steel, and other various resin materials can be used. .
Further, the first clamping member 5 has lower rigidity than the second clamping member 6 and the third clamping member 7. Thereby, the 1st clamping member 5 becomes easier to deform | transform than the 2nd clamping member 6 and the 3rd clamping member 7 (refer FIG.5 (b), (c)). In addition, as a method of satisfying such a magnitude relationship, there are a method of selecting a constituent material and a method of giving a magnitude relationship to the thickness of each clamping member.

The strain sensor 52 is fixed on the surface 513 of the clamping member main body 51 that is configured separately from the strain sensor 52. The fixing method is not particularly limited, and examples thereof include a method using adhesion (adhesion with an adhesive or a solvent).
When the force is applied to the clamping member main body 51 (the first clamping member itself) and the clamping member main body 51 is deformed (bent), the strain sensor 52 deforms at that time (the second clamping member 6). , A sensor for detecting the distortion in the moving direction of the third clamping member 7. The robot 1 can grasp the clamping state of the first work 701 and the second work 702 according to the detection result, and can transport these works together with the robot hand 10.

Various strain sensors 52 can be used. For example, a sensor capable of detecting a plurality of axes is preferably used. This multi-axis strain sensor is a six-axis sensor that detects the forces in the directions of the three axes perpendicular to each other and the moments about the respective axes, and can easily and reliably detect the strain generated in the holding member main body 51. it can.
Further, the strain sensor 52 has a small piece shape and is configured separately from the holding member main body 51. Thereby, the strain sensor 52 can be disposed and fixed at a desired position of the holding member main body 51. And as this desired position, it is preferable that it is especially the base end part 511 vicinity of the clamping member main-body part 51. FIG. This “near base end portion 511” is a portion where distortion is most likely to occur in the clamping member main body 51 when a force is applied to the clamping member main body 51.

Next, a process from the time when the robot hand 10 grips the first work 701 and the second work 702 until the transfer is started will be described with reference to FIG. Here, the case where the clamping force with respect to each of the first work 701 and the second work 702 is set to “100 gf” is taken as an example.
First, as shown in FIG. 5A, the first work 701 and the second work 702 are respectively placed on the stage 800 at a predetermined interval, that is, separated from each other. The robot 1 causes the robot hand 10 to approach the first work 701 and the second work 702 in this state from above. At this time, the distance between the first clamping member 5 and the second clamping member 6 is larger than the diameter of the first workpiece 701, and the first workpiece 701 is disposed between these clamping members. Further, the distance between the first clamping member 5 and the third clamping member 7 is also larger than the diameter of the second workpiece 702, and the second workpiece 702 is disposed between these clamping members.
The detection value (distortion) detected by the strain sensor 52 is “zero”.

Next, from the state shown in FIG. 5A, as shown in FIG. 5B, the first mechanism 81 of the support mechanism 8 is operated to move the second holding member 6 toward the first holding member 5. Move and approach. As a result, the second clamping member 6 comes into contact with and presses the first workpiece 701, and the first workpiece 701 is clamped between the first clamping member 5 and the second clamping member 6.
At this time, the sandwiching member main body 51 of the first sandwiching member 5 receives a pressing force from the second sandwiching member 6 via the first work 701, and thus bends in the pressing direction (FIG. 5B). reference). As a result, the value detected by the strain sensor 52 increases (rises) from “zero”. Then, when the strain sensor 52 detects “50 gf”, the movement of the second clamping member 6 is stopped. At this time, the first work 701 is clamped with a clamping force of “50 gf”.

Next, as shown in FIG. 5C, the second mechanism 82 of the support mechanism 8 is operated to move and approach the third clamping member 7 toward the first clamping member 5. As a result, the third clamping member 7 comes into contact with and presses against the second workpiece 702, and the second workpiece 702 is clamped between the first clamping member 5 and the third clamping member 7.
At this time, the clamping member main body 51 of the first clamping member 5 receives a pressing force from the third clamping member 7 via the second workpiece 702, so that it bends in the pressing direction and returns to its original state. (See FIG. 5C). As a result, the value detected by the strain sensor 52 decreases (decreases) from “50 gf”. Then, when the strain sensor 52 detects “zero”, the movement of the third clamping member 7 is stopped. At this time, the first workpiece 701 and the second workpiece 702 are each clamped with the same clamping force of “100 gf”.

Next, as shown in FIG. 5 (d), the robot 1 can be actuated to raise the first work 701 and the second work 702 together with the robot hand 10 and carry them.
As described above, in the robot hand 10, one strain sensor 52 is used to sandwich two workpieces. That is, in the robot hand 10, one strain sensor 52 is configured by the clamping mechanism configured by the first clamping member 5 and the second clamping member 6, and the first clamping member 5 and the third clamping member 7. Shared (shared) with the clamping mechanism.

Therefore, the number of the strain sensors 52 installed in the robot hand 10 is reduced as much as possible (“one” in the present embodiment). Then, using the detection result of the single strain sensor 52, it is possible to reliably hold the two workpieces (a plurality of objects to be grasped) with a desired force (“100 gf” in the present embodiment).
In the configuration shown in FIG. 5, the clamping operation by the first clamping member 5 and the second clamping member 6 is performed, and then the clamping operation by the first clamping member 5 and the third clamping member 7 is performed. However, the order of the pinching operation may be reversed.

Second Embodiment
FIG. 6 is a perspective view showing a second embodiment of the robot hand according to the present invention.
Hereinafter, the robot hand, the robot hand gripping method, and the second embodiment of the robot according to the present invention will be described with reference to this figure. However, the differences from the above-described embodiment will be mainly described, and the same matters will be described. The description is omitted.
The present embodiment is the same as the first embodiment except that the configuration of the first clamping member is different from the number of arrangements of the second clamping member and the third clamping member.

In the robot hand 10 of this embodiment shown in FIG. 6, the first clamping member 5 itself is a strain sensor. Thereby, unlike the said 1st Embodiment, the 1st clamping member 5 becomes a thing by which the clamping member main-body part 51 was abbreviate | omitted, and becomes a simple structure.
The first clamping member 5 is branched into two in the distal direction in the middle of the longitudinal direction (vertical direction in FIG. 6), and has a first branch part 53 and a second branch part 54. ing.

Moreover, the 2nd clamping member 6 and the 3rd clamping member 7 have comprised the pair. The pair of the second clamping member 6 and the third clamping member 7 are arranged in two pairs (two sets) on the opposite sides via the central axis 55 of the first clamping member 5. One set of the second holding member 6 and the third holding member 7 are arranged to face each other via the first branching portion 53 of the first holding member 5, and the other set of the second holding member 6 and the third holding member 7. Are arranged opposite to each other via the second branch portion 54 of the first clamping member 5.
With such a configuration, the second holding member 6 and the first branching portion 53 of the first holding member 5, the third holding member 7 and the first branching portion 53 of the first holding member 5, the second A maximum of four workpieces can be placed at a total of four locations between the clamping member 6 and the second branching portion 54 of the first clamping member 5 and between the third clamping member 7 and the second branching portion 54 of the first clamping member 5. Can be held together.

<Third Embodiment>
FIG. 7 is a perspective view showing a third embodiment of the robot hand according to the present invention, and FIG. 8 is a view (plan view) seen from the direction of arrow A in FIG.
Hereinafter, the robot hand, the robot hand gripping method, and the third embodiment of the robot according to the present invention will be described with reference to these drawings. However, the differences from the above-described embodiment will be mainly described, and similar matters will be described. Will not be described. The configuration of the first clamping member is the same as that of the first embodiment except that the arrangement number of the second clamping member and the third clamping member is different.

In the robot hand 10 of the present embodiment shown in FIGS. 7 and 8, the clamping member main body 51 of the first clamping member 5 has a regular quadrangular prism shape. Of the four side surfaces 514, 515, 516, and 517 of the holding member main body 51, the strain sensors 52 are fixed to the side surfaces 514 and 515 that are adjacent (normal vectors are orthogonal).
Moreover, the 2nd clamping member 6 and the 3rd clamping member 7 have comprised the pair. Then, two pairs (two sets) of the paired second clamping member 6 and third clamping member 7 are arranged around the central axis 55 of the first clamping member 5. In other words, the second clamping member 6 and the third clamping member 7 that are paired cross the two different movement directions with the first clamping member 5 as an intersection, and the respective movement directions of the respective members are different. It is arranged against.

With such a configuration, between the second clamping member 6 and the side surface 514 of the first clamping member 5, between the third clamping member 7 and the side surface 516 of the first clamping member 5, between the second clamping member 6 and the first clamping member 5. A maximum of four workpieces can be clamped at a total of four locations between the side surface 515 of the clamping member 5 and between the third clamping member 7 and the side surface 517 of the first clamping member 5.
In the robot hand 10, the two strain sensors 52 can be used to hold four workpieces, and therefore the number of strain sensors 52 installed is reduced as much as possible.

<Fourth embodiment>
FIG. 9 is a plan view showing a fourth embodiment of the robot hand according to the present invention.
Hereinafter, the robot hand, the robot hand gripping method, and the fourth embodiment of the robot according to the present invention will be described with reference to this figure. The differences from the above-described embodiment will be mainly described, and the same matters will be described. The description is omitted.
The present embodiment is the same as the third embodiment except that the number of arrangement of the second clamping member and the third clamping member is different.

In the robot hand 10 of the present embodiment shown in FIG. 9, the clamping member main body 51 of the first clamping member 5 has a regular octagonal prism shape. Of the eight side surfaces 514, 515, 516, 517, 518, 519, 520, and 521 of the clamping member main body 51, the strain sensors 52 are fixed to the side surfaces 514 and 516, respectively, whose normal vectors are orthogonal to each other. .
Then, four pairs (four sets) of the paired second clamping member 6 and third clamping member 7 are arranged around the central axis 55 of the first clamping member 5.
With such a configuration, a maximum of eight workpieces can be collectively held between each of the eight clamping members and the side surface of the first clamping member 5 facing the clamping member.

<Fifth Embodiment>
10 is a side view showing a fifth embodiment of the robot hand according to the present invention, FIG. 11 is a view seen from the direction of arrow B in FIG. 10, and FIG. 12 is a cross-sectional view taken along the line CC in FIG. It is.
Hereinafter, the robot hand, the robot hand gripping method, and the fifth embodiment of the robot according to the present invention will be described with reference to these drawings. However, the differences from the above-described embodiment will be mainly described, and similar matters will be described. Will not be described.
This embodiment is the same as the first embodiment except that the configurations of the first clamping member, the second clamping member, and the third clamping member are different.

In the robot hand 10 of the present embodiment shown in FIG. 10, the clamping member main body 51 of the first clamping member 5 has a free end branched into two like a rake, and a first branching portion 53 and a second branching portion. 54. Since the 1st branch part 53 and the 2nd branch part 54 are the same structures, the 1st branch part 53 is demonstrated typically below.
The first branch portion 53 includes an elastic film 56 and a frame body 57.
The elastic film 56 is substantially rectangular (see FIG. 11) and is made of an elastic material. This material is not particularly limited, and for example, various rubber materials such as urethane rubber, silicone rubber, and fluorine rubber can be used.
The frame body 57 is a member that holds the edge of the elastic film 56.

As shown in FIG. 12, when the first work 701 is sandwiched by the first branch portion 53, the elastic film 56 is curved and deformed along the outer shape of the first work 701. Thereby, the elastic film 56 can prevent the contact area with the 1st workpiece | work 701 from increasing, and the said 1st workpiece | work 701 slipping down unintentionally. Further, even when the first work 701 is relatively easily damaged by contact with the outside, the elastic film 56 is preferable because it can prevent the first work 701 from being damaged.
In the robot hand 10, similarly to the first branching portion 53, the second holding member 6 also has an elastic film 62 having elasticity and a frame body 63 that holds the edge of the elastic film 62. . Further, the third clamping member 7 also has an elastic film 72 having elasticity and a frame body 73 that holds the edge of the elastic film 72.

<Sixth Embodiment>
FIG. 13 is a side view showing a sixth embodiment of the robot hand according to the present invention.
Hereinafter, the robot hand, the robot hand gripping method, and the sixth embodiment of the robot according to the present invention will be described with reference to this figure. The difference from the above-described embodiment will be mainly described, and the same matters will be described. The description is omitted.
This embodiment is the same as the fifth embodiment except that the robot hand includes a holding member different from the first to third holding members.

In the robot hand 10 of the present embodiment shown in FIG. 13, the second clamping member 6 is branched into two in the middle of the longitudinal direction, and has a first branch part 64 and a second branch part 65. Yes. And the 1st branch part 64 and the 2nd branch part 65 are the structures which have the elastic film 62 and the frame 63, respectively.
The third clamping member 7 is branched into two in the middle of the longitudinal direction, and has a first branch portion 74 and a second branch portion 75. And the 1st branch part 64 and the 2nd branch part 65 are the structures which have the elastic film 62 and the frame 63, respectively.

In the robot hand 10, a separate clamping member (fourth clamping member 60) is further arranged on the opposite side of the second clamping member 6 from the first clamping member 5, and the first clamping member 5 of the third clamping member 7. A separate clamping member (fifth clamping member 70) is further arranged on the opposite side. The fourth clamping member 60 and the fifth clamping member 70 can move independently by the operation of the support mechanism 8.
Similarly to the first branching portion 53, the fourth clamping member 60 has a configuration including an elastic film 601 having elasticity and a frame body 602 that holds an edge of the elastic film 601.
Similarly to the first branch portion 53, the fifth clamping member 70 also has an elastic film 704 having elasticity and a frame body 703 that holds the edge of the elastic film 704.
With the configuration as described above, a maximum of four workpieces can be clamped at a time between the clamping members at four locations.

<Seventh embodiment>
FIG. 14 is a front view of a robot (seventh embodiment) according to the present invention.
Hereinafter, the robot hand of the present invention, the robot hand gripping method, and the seventh embodiment of the robot will be described with reference to this figure. However, the differences from the above-described embodiment will be mainly described, and the same matters will be described. The description is omitted.
This embodiment is the same as the first embodiment except that the number of robot arms is different.

As shown in FIG. 14, in the present embodiment, the robot 1 includes a trunk portion 18 and two arms (robot arms) 19 supported on both sides of the trunk portion 18.
Each arm 19 is an articulated arm, and the robot hand 10 can be detachably attached to the tip of the arm 19. Thereby, the operation | work by the two robot hands 10 can be performed, Therefore The work efficiency improves.

As described above, the robot hand, the robot hand gripping method, and the robot according to the present invention have been described with respect to the illustrated embodiment. However, the present invention is not limited to this, and the parts constituting the robot hand and robot are the same It can be replaced with any structure that can exhibit the above function. Moreover, arbitrary components may be added.
In addition, the robot hand, the robot hand gripping method, and the robot of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

The number of robot arms provided in the robot is one in the first to sixth embodiments and two in the seventh embodiment. However, the number of robot arms is not limited to this. For example, the number of robot arms is three or more. May be.
Moreover, although it was a rigid body in the said 1st-7th embodiment as a 1st workpiece | work and a 2nd workpiece | work, it is not limited to this, An elastic body may be sufficient.
In the fifth embodiment, the first clamping member, the second clamping member, and the third clamping member each have an elastic film and a frame body. However, the present invention is not limited to this. One or two of the sandwiching member, the second sandwiching member, and the third sandwiching member may have an elastic film and a frame.

DESCRIPTION OF SYMBOLS 1 ... Robot 11 ... Base 111 ... Bolt 112 ... Base main body (housing) 113 ... Cylindrical part 12, 13, 14, 15 ... Arm (link) 16 ... List (link) 161 ... ... wrist body (mounting part) 162 ... support ring 163 ... tip surface 165 ... connector 171, 172, 173, 174, 175, 176 ... joint (joint) 2, 2a, 2b, 2c, 2d ... arm Main body 3, 3a, 3b, 3c, 3d ... Drive mechanism 4, 4a, 4b, 4c, 4d ... Sealing means 5 ... First clamping member (first clamping portion) 51 ... Holding member main body portion 511 ... ... Base end part 512, 513 ... Face 514, 515, 516, 517, 518, 519, 520, 521 ... Side face 52 ... Strain sensor (strain gauge) 53 ... First branch part 54 ... Second branch Part 55 …… Center axis 56 …… Elastic membrane 57 …… Frame body 6 …… Second clamping member (second clamping portion) 61 …… Base end 62 …… Elastic membrane 63 …… Frame body 64 …… First Branching portion 65 …… Second branching portion 7 …… Third clamping member (third clamping portion) 71 …… Base end portion 72 …… Elastic membrane 73 …… Frame body 74 …… First branching portion 75 …… Second Bifurcation 8 ... Support mechanism 81 ... First mechanism 82 ... Second mechanism 83 ... Case 10 ... Robot hand 18 ... Body 19 ... Arm (robot arm) 20 ... Personal computer (PC) 301, 302, 303, 304, 305, 306... Motor driver 401, 402, 403, 404, 405, 406... Motor 50a, 50b... Cylindrical part 60. ... Frame body 70 ... Fifth clamping member 7 03 …… Frame 704 …… Elastic film 101 …… Floor 701 …… First work (first object to be grasped) 702 …… Second work (second object to be grasped) 800 …… Stage O ₁ , O ₂ , O ₃ , O ₄ , O ₅ , O ₆ ...... Rotating shaft

Claims (8)

A strain sensor that detects strain;
A first clamping part connected to one end of the strain sensor;
A second clamping part movable in a moving direction approaching or separating from the first clamping part;
A third sandwiching portion disposed at a position sandwiching the first sandwiching portion together with the second sandwiching portion and movable in the moving direction;
A holding portion that connects the other end of the strain sensor to hold the first holding portion and holds the second holding portion and the third holding portion and moves the holding portion in the moving direction. A robot hand that grips an object to be grasped between the first clamping unit and the second clamping unit or between the first clamping unit and the third clamping unit.   The robot hand according to claim 1, wherein the strain sensor detects strain in the moving direction.   At least one of the first sandwiching portion, the second sandwiching portion, and the third sandwiching portion includes a frame body held by the holding portion, and an edge portion fixed to the frame body and elastic. The robot hand according to claim 1, further comprising: an elastic membrane having   The free end of at least one of the first clamping unit, the second clamping unit, and the third clamping unit has a free end branched in a rake shape. Robot hand.   A plurality of different moving directions are crossed with the first holding part as an intersection, and the second holding member and the third holding member are arranged in each of the different directions of movement. The robot hand according to any one of claims. A method for gripping a robot hand including a first clamping unit, a second clamping unit, and a third clamping unit,
Sandwiching a first object to be gripped between the first sandwiching portion provided with a strain sensor for detecting strain and the second sandwiching portion movable in a moving direction approaching or separating from the first sandwiching portion; Next, a second object to be grasped is sandwiched between the first sandwiching portion and the second sandwiching portion and the third sandwiching portion which is disposed at a position sandwiching the first sandwiching portion and movable in the moving direction. A method of gripping a robot hand, characterized in that:   Detecting the strain that increases when the first object is held, stops the movement of the second holding part, and then holds the first object while holding the first object. The robot hand gripping method according to claim 6, wherein the distortion that decreases when an object is sandwiched is detected to stop the movement of the third gripper. The robot hand according to any one of claims 1 to 5,
A robot comprising: at least one robot arm on which the robot hand is detachably attached to a tip.

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