JP2012218105A - Robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot hand which can move a grabbing object without limitation of a movable range of a finger part.SOLUTION: This robot hand includes at least a pair of finger parts 101 and 102 for grabbing an object, and includes: a cylindrical rotary member 111 having a rotary axis identical to a long direction of the finger parts 101 and 102 in a portion facing the finger parts 101 and 102; a recess 121 for storing the cylindrical rotary member 111 in the finger part; and a rotation drive part 131 for rotating the cylindrical rotary member 111 inside the finger part. The cylindrical rotary member 111 protrudes more toward the object 4 side than a contact part 105.

Description

  The present invention relates to a robot hand.

  A robot hand that is attached to a robot apparatus such as an industrial robot arm and performs a predetermined operation by grasping or releasing an object is known. In recent years, for example, there has been proposed a multi-functional robot hand that grips a tool and performs operations such as assembling components, and grips a minute component and arranges it with high accuracy.

  For example, in the robot hand of Patent Document 1, three fingers that grip an object are attached to a finger support portion, and each finger is supported by the finger support portion so as to be movable in parallel through a drive mechanism. Yes. By simultaneously translating these three fingers, the object to be grasped can be translated while being grasped.

JP-A-6-155358

  In the technique of Patent Document 1, the translation of the gripping target is realized by translating the finger itself gripping the target. However, in this method, the range in which the object to be grasped can be moved greatly depends on the structure of the robot hand. Therefore, there has been a demand for a robot hand that can move the gripping object without being limited to the finger movable range.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A robot hand according to this application example is a robot hand having a plurality of finger parts that can be opened and closed, and has a rotating part that is rotated by a rotation driving part at least on the side facing the finger parts. The rotating unit rotates in contact with the object to move the object.

  According to this application example, the robot hand has a plurality of fingers that can be opened and closed. Therefore, the object can be gripped by opening and closing the finger part. And a finger part has a rotation part rotated by the rotation drive part on the opposite side. Therefore, the rotating part can be brought into contact with the object when gripping. And the force of the same direction can be applied to a grasp object by making a rotation part contact an object, and rotating a rotation part of a place which counters mutually reversely. Accordingly, the object can be moved without being limited to the range in which the finger part can be opened and closed.

  Application Example 2 In the robot hand according to the application example described above, it is preferable that the finger portion includes a concave portion that houses the rotating portion, and an elastic portion that urges the rotating portion so as to protrude from the concave portion. .

  According to this application example, the finger portion has a recess that houses the rotating portion. This recessed portion becomes a space for storing the rotating portion when gripping. For this reason, a rotation part can be accommodated in a recessed part. Thus, the rotating part can be completely stored during normal gripping, and the part in contact with the gripping object can be changed from line contact by the rotating part to surface contact between the rotating part and the finger part. Furthermore, the finger part has an elastic part that urges the rotating part to protrude from the concave part. These operations can be switched by changing the force applied to the elastic portion between the movement of the object and the gripping of the object. Therefore, the object can be reliably grasped when grasped, and the object can be moved with high quality when the object is desired to be moved.

  Application Example 3 The robot hand according to the application example described above includes a drive unit that opens and closes the pair of finger parts so that the pair of finger parts approaches or moves away from the object in synchronization. preferable.

  According to this application example, the drive unit opens and closes the pair of finger units to bring the pair of finger units closer to the object in synchronization. Accordingly, after the pair of finger portions are arranged at an equal distance from the object, the pair of finger portions are brought close to the object, thereby making it easier to stably hold the object. Moreover, when moving a target object, a finger part can be made to contact a target object from both surfaces by bringing a pair of finger part close to a target object by the same method. And an object can be moved by rotating a rotation part after making it contact. As a result, the object can be moved with high quality.

  [Application Example 4] In the robot hand according to the application example described above, the distance between the finger parts when opening and closing the finger parts located at opposite positions is the width of the object and the object is moved. It is preferable that it is determined by the operation content of whether to hold or hold.

  According to this application example, when the distance between the facing finger parts is narrower than the width of the object, the rotating part built in the finger part is housed in the recess. For this reason, an object can be grasped stably. Further, in the case where the width of the object is set to be approximately as large as the radius of the rotating part built in the finger part, the object and the finger part are in contact with each other only by the rotating part. For this reason, it will be in the holding state which can move a target object in a rotation part. Therefore, switching of the operation between when the object is moved by the rotating unit and when it is gripped can be realized by a very simple operation.

1 is a schematic perspective view illustrating a configuration of a robot hand according to a first embodiment. The principal part expansion perspective view which shows a finger | toe part. The schematic diagram for demonstrating the front-end | tip internal structure of a finger | toe part. The schematic diagram for demonstrating the method to move a holding | grip object. The schematic diagram for demonstrating the method to hold | grip a holding object. The schematic perspective view which shows the structure of the finger | toe part concerning the modification 1. FIG. The schematic perspective view which shows the structure of the finger | toe part concerning the modification 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is made different from the actual scale in order to make each member recognizable.

(Embodiment 1)
FIG. 1 is a schematic perspective view illustrating the configuration of the robot hand according to the first embodiment. FIG. 2 is an enlarged perspective view of a main part showing a finger part. FIG. 3 is a schematic diagram for explaining the internal structure at the tip of the finger. FIG. 4 is a schematic diagram for explaining a method of moving the gripping target. FIG. 5 is a schematic diagram for explaining a method of gripping a gripping target.

  As shown in FIG. 1, the robot hand 1 includes at least a pair of fingers 101 to 104, a drive unit 160 that opens and closes the fingers 101 to 104, and a drive unit 170 that rotates the drive unit 160. Yes. The robot hand 1 is used by being incorporated in a robot (not shown). First, a schematic configuration of the robot hand 1 according to the first embodiment will be described.

  The robot hand 1 is used as a gripping device for an industrial robot that grips an object such as a tool or a part. The robot hand is not limited to an industrial robot, and may be used for other purposes (space-related, play equipment, etc.).

  In the first embodiment, four fingers are provided in the robot hand 1, but the number of pairs of fingers facing each other is not limited to two. One set or three or more sets may be used.

  The drive unit 160 is attached to one end of the finger units 101 to 104. The driving unit 160 opens and closes the pair of finger units 101 and 102 by moving the finger units 101 and 102 so as to approach or move away from the object in synchronization. The same applies to the finger portions 103 and 104.

  The drive unit 170 is attached to one end of the drive unit 160. The drive unit 170 rotates the drive unit 160 to rotate the entire robot hand 1. The robot hand 1 includes a control device 130, and the finger units 101 to 104, the drive unit 160, and the drive unit 170 operate according to control signals output from the control device 130.

  As shown in FIGS. 2 and 3, the finger parts 101 to 104 include a rotating member 111 as a rotating part and a concave part 121 for storing the rotating member 111 inside the finger part. The rotating member 111 has a cylindrical shape, and a part of the cylindrical curved surface is built in so that it can be seen from the opposing sides of the pair of finger portions 101 to 104. The recess 121 is slightly larger than the rotating member 111. This prevents the rotation from being hindered by preventing the rotation member 111 from contacting the inner surface of the recess 121 when the rotation member 111 is rotated. Each of the finger units 101 to 104 includes a rotation drive unit 131, and the rotation shaft of the rotation drive unit 131 is connected to the rotation member 111. The rotation drive unit 131 is made of, for example, an electric motor and can be rotated clockwise and counterclockwise.

  The finger parts 101 to 104 are parts for gripping an object. In the robot hand 1, the rotating member 111 built in the finger unit is rotated by the rotation driving unit 131 built in the finger unit while the object is gripped by at least the pair of finger units 101 and 102. The object can be moved horizontally.

  The rotating member 111 is provided so that a part protrudes compared with the contact part 105 which is a part which contacts a target object in the finger parts 101-104. Thus, when the object is gripped, it is the rotating member 111 that first contacts the object. Hereinafter, the description regarding the single finger 101 is applied to all four fingers.

  The rotating member 111 is desirably an elastic body typified by rubber. This is to prevent the object from being damaged. Further, the rotating member 111 can be brought into contact with the object by being deformed corresponding to the unevenness of the object. Thereby, contact resistance can be enlarged. The elastic body of the rotating member 111 is not limited to rubber, and various materials can be used. As the material of the rotating member 111, for example, various types of resins such as urethane and hollow structure materials such as sponge can be employed.

  The finger unit 101 includes a support member 141 that supports a rotation drive unit 131 that rotates the rotation member 111. The support member 141 is made of a material having elasticity, and has a function of absorbing and attenuating vibration even when the rotation drive unit 131 and the rotation member 111 vibrate.

  The finger unit 101 includes a rotation member 111, a support member 141, a rotation drive unit 131 typified by a motor, and an elastic body 151 as an elastic unit typified by a spring. Both ends of the support member 141 connect the rotation member 111 and the rotation drive unit 131. The support member 141 is provided with a rolling bearing (such as a ball bearing) that rotatably supports the rotating shaft of the rotating member 111. Thereby, the rotating member 111 rotates smoothly. The elastic body 151 connects the inside of the finger part 101 to the rotation drive part 131 and the rolling bearing. In a state where no force is applied, as described above, a part of the rotating member 111 is provided so as to protrude to the outside of the concave portion 121 as compared with the contact portion 105. The amount by which the rotating member 111 protrudes from the contact portion 105 is defined as a protrusion amount 112.

  Next, a method for moving the robot hand 1 without gripping the object will be described. As shown in FIG. 4, when a control signal (finger part closing signal) is transmitted from the control device 130 to the drive unit 160, the drive unit 160 moves the finger units 101 to 104 according to the width 4 a of the object 4. To close. The closing operation refers to an operation for narrowing the interval between the finger portions 101 to 104. The width 4 a of the object 4 is measured by the user in advance and is input to the control device 130. When the closing operation is performed in order to perform the parallel movement of the object 4, a control signal indicating that the closing operation for translating the object 4 is performed from the control device 130 to the driving unit 160 is output. The drive part 160 moves the finger parts 101-104 according to a control signal. A width dimension of the object 4 is defined as a width 4a, and a distance between the contact portion 105 of the finger portion 101 and the contact portion 105 of the finger portion 102 is defined as a finger-to-finger distance 113 as a distance between the finger portions. That is, the inter-finger distance 113 is a distance between finger parts.

  Then, the driving unit 160 sets the inter-finger distance 113 to a distance longer than the width 4a and shorter than a distance obtained by adding twice the protrusion amount 112 and the width 4a. The drive unit 160 moves in the same manner for the finger unit 103 and the finger unit 104. Thereby, only the protrusion part of the rotation member 111 incorporated in each finger part 101,102,103,104 contacts with the target object 4. This state is referred to as a “parallel movement state”.

  In the parallel movement state, the control device 130 rotates the rotating member 111 built in the finger units 101 to 104 by the rotation driving unit 131. Thereby, a force is applied to the object 4 to move the object 4. The rotation member 111 rotates in synchronization with the rotation direction and the rotation speed so as to push out the object 4 in the same direction. At this time, the rotating direction of the rotating member 111 is reversed in the opposing finger portions 101 and 102. In addition, in the finger portions 101 and 103 having the same direction, the rotation direction of the rotation member 111 is set to the same direction.

  Next, a method in which the robot hand 1 holds the object 4 without moving in parallel will be described. As shown in FIG. 5, when a control signal (a finger closing operation signal) is transmitted from the control device 130 to the driving unit 160, the driving unit 160 changes the finger units 101 to 104 according to the width 4 a of the object 4. To close. At this time, a signal indicating that the closing operation is not accompanied by the parallel movement of the object 4 is sent to the drive unit 170.

  Then, the driving unit 160 sets the inter-finger distance 113 equal to the width 4a. At this time, the object 4 presses the rotating member 111. Then, the elastic body 151 contracts by the force applied from the object 4. As a result, the rotating member 111 is pushed into the recess 121 for storage. As a result, the object 4 and the finger parts 101 to 104 come into contact with not only the rotating member 111 but also the contact part 105. This state is hereinafter referred to as “stable gripping state”. In the stable gripping state, the rotating member 111 is housed in the recess 121 in the finger portions 101 to 104.

  According to the robot hand 1 of the present embodiment, the object 4 can be translated by rotating the rotating member 111 of the pair of finger portions 101 and 102 by the rotation driving unit 131. For example, when the object is a rectangular parallelepiped member placed on the work surface, the finger part 101 and the finger part 102 facing each other are gripped in a state in which the object is in contact with the object only by the rotating member 111. And At this time, the rotation member 111 is rotated in the opposite rotation direction by the rotation driving unit 131, so that a force for translation can be applied via a point in contact with the object 4. In this parallel movement, the moving distance depends only on the diameter and the number of rotations of the rotating member 111 and the length of the object, and does not depend on the mechanism of the hand. Therefore, it is possible to provide the robot hand 1 that holds the object with high productivity by moving the object in parallel with only the hand.

  According to the configuration of the robot hand 1, the concave portion 121 that houses the finger portion 101 and the elastic body 151 that biases the rotating member 111 are provided. Therefore, by applying a certain force or more to the rotating member 111, the elastic body contracts and the rotating member can be completely stored in the recess 121. Therefore, it is possible to switch between the parallel movement state and the stable gripping state only by changing the force applied to the rotating member.

  According to this configuration, since the drive unit 160 that opens and closes the pair of finger parts 101 and 102 is provided, the pair of finger parts 101 and 102 can easily hold the object. Therefore, it becomes easy to stably hold the object. Moreover, the opening / closing operation | movement of a pair of finger parts 101 and 102 is realizable with simple structure.

  According to this configuration, at the time of a grip command, a finger that is the distance between the contact portions 105 of the opposing finger portions 101 and 102 in each state is sent simultaneously as a command indicating whether the state is a parallel movement state or a stable grip state. A distance 113 is set. That is, in the parallel movement state, the distance between the contact portions 105 of the finger portions 101 to 104 is set slightly wider than the width 4a of the target object 4 so that only the protruding portion of the rotating member 111 is in contact with the target object. On the other hand, in the stable gripping state, the distance between the contact portions 105 of the finger portions 101 and 102 is set to a distance equal to the width 4a of the object 4 in order to touch the object with the entire finger portion. At this time, the rotating member 111 is pushed into the recess 121 by the object 4. Therefore, the stable gripping state and the parallel movement state can be switched by the distance between the finger portions 101 to 104 facing each other.

  In addition, this invention is not limited to embodiment mentioned above, A various change, improvement, etc. can be added to embodiment mentioned above. A modification will be described below.

(Modification 1)
FIG. 6 is a schematic perspective view illustrating a configuration of a finger portion according to the first modification.
In Embodiment 1 described above, the rotating member 111 to be attached to one finger portion 101 to 104 has been described as having one configuration, but the present invention is not limited to this configuration. Hereinafter, the robot hand 2 according to Modification 1 will be described. In addition, about the component same as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

  As shown in FIG. 6, two or more rotating members 111 (hereinafter referred to as a rotating member 111 a as a rotating unit and a rotating member 111 b as a rotating unit) may be attached to the finger unit 190 of the robot hand 2. In addition, the rotation drive part 131 may install the same thing with respect to the rotation members 111a and 111b, and may be installed for every rotation member 111. FIG.

  When two or more rotating members 111 are built in the finger part 190, it is desirable to use the same rotating shaft. This is to increase stability when the rotating member 111 is pushed into the recess 121. However, this is not the case when assuming a state in which a plurality of rotation driving units 131 are prepared in order to individually change the rotation directions of the rotation members 111 incorporated in the same finger unit 190.

As described above, according to the robot hand 2 according to the present modification, in addition to the effects in the first embodiment, the following effects can be obtained.
By attaching a plurality of rotating members 111 to one finger part 190, it is possible to hold a larger object to be grasped and perform parallel movement. Moreover, it becomes possible to make the parallel movement of the target object 4 with a stronger force by increasing a rotation part.

(Modification 2)
FIG. 7 is a schematic perspective view illustrating a configuration of a finger portion according to the second modification.
In the first embodiment, the direction of the rotation axis of the rotating member 111 and the long direction of the finger portions 101 to 104 have been described as being in the same direction. However, the present invention is not limited to this configuration. Hereinafter, the robot hand 3 according to Modification 2 will be described. In addition, about the component same as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

  As shown in FIG. 7, a rotating member 201 is installed on the finger part 200 of the robot hand 3. The rotation axis of the rotation member 201 is perpendicular to the longitudinal direction of the finger part 200 and parallel to the surface of the contact part 105 of the finger part. In addition, the internal structure in this structure is easily realizable by utilizing gears, such as a rotation drive part 131 and a helical gear.

As described above, according to the robot hand 3 according to the present modification, in addition to the effects in the first embodiment, the following effects can be obtained.
By attaching the direction of the rotation axis of the rotating member 201 in a direction perpendicular to the long direction of the finger part 200, the object 4 can be moved in a direction different from that in the first embodiment.

  1, 2, 3 ... Robot hand, 101, 102, 103, 104 ... Finger part, 111, 111a, 111b ... Rotating member as rotating part, 113 ... Inter-finger distance as distance between finger parts, 121 ... Recessed part, 131... Rotation drive unit, 151... Elastic body as elastic unit, 160.

Claims (4)

A robot hand having a plurality of fingers that can be opened and closed,
At least a pair of the finger parts facing each other has a rotating part that is rotated by a rotation driving part, and the rotating part rotates in contact with an object to move the object. . The robot hand according to claim 1, wherein
2. The robot hand according to claim 1, wherein the finger portion includes a concave portion that houses the rotating portion, and an elastic portion that urges the rotating portion so as to protrude from the concave portion. In the robot hand according to claim 1 or 2,
A robot hand comprising: a drive unit that opens and closes the pair of finger parts so that the pair of finger parts approach or move away from the object in synchronization. In the robot hand according to any one of claims 1 to 3,
The distance between the finger parts when opening and closing the finger parts located at opposite positions is determined by the width of the object and the operation content of moving or grasping the object. Robot hand characterized by that.

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