JPH0938883A - Robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a hold subject by a small fluid pressure surely by supporting bellows by a support member respectively so as to extend/contract facing to a hold subject side and forming the tip surface of each bellow to a hold surface. SOLUTION: When an adsorption nozzle N is adsorbed to an orange, the approaching drive to the orange side of a supporter 2 is stopped. A pressurized air is supplied from a first pump 3 in a main flow passage R1 and a piston 9 is pushed to a finger root side against the energizing force of a spring 14 and a support shaft 6 is moved inside the supporter 2 and the orange is lifted upto a hold position. A piston 9 reaches a stroke end and a sub-flow passage R2 is communicated with an air supply/discharge port 10 and the bellows 4 are extended by a pressurized air and the orange is held. As the bellows 4 is extended facing to the orange side, an entire extension force of the bellows 4 can be made to a hold force and the orange can be held surely by the small fluid pressure.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a robot hand.

[0002]

2. Description of the Related Art Conventionally, a robot hand, as disclosed in, for example, Japanese Patent Laid-Open No. 61-203287, supports a soft tubular finger-formation body having a bellows on its back with a support member, and an inner space of the finger-formation body. The pressure of the fluid supplied to the bellows extends the bellows, and the extension force of the bellows bends the finger forming body toward the abdomen to hold the gripping target.

[0003]

According to the above-mentioned conventional structure, since the direction in which the extension force of the bellows acts is deviated from the gripping direction, it is the extension force that acts on the object to be gripped as the gripping force. It is only a part, and the fluid pressure has to be considerably increased in order to reliably grasp the object to be grasped.

An object of the present invention is to provide a robot hand capable of reliably gripping an object to be gripped with a fluid pressure smaller than before.

[0005]

According to a first aspect of the present invention, a plurality of bag-shaped bellows that expand and contract by the fluid pressure of the fluid supplied to and discharged from the internal space expand and contract toward the object to be grasped. As described above, the support members individually support each other, and the tip end surface of each bellows is formed as a gripping surface.

According to a second aspect of the present invention, in the invention according to the first aspect, as the bellows expands,
A restraining portion that bends the tip gripping surface by pulling and restraining a predetermined portion of the tip end surface from the back side is provided in the bellows.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the peripheral portion of the bellows is
The bellows wall thickness of the first region is divided into a pair of first regions that face each other in the radial direction and a pair of second regions that are located between the first regions and that face each other in the radial direction. It is set to be thicker than the wall thickness of the bellows in the two regions.

According to a fourth aspect of the present invention, in the invention according to any one of the first, second and third aspects, a peripheral portion of the bellows is provided with a pair of first regions facing each other in a radial direction.
The height dimension of the pleats of the bellows in the first area is divided into a pair of second areas that are located between both the first areas and are opposed to each other in the radial direction. It is set lower than the size.

[0009]

The operation of the present invention will be described with reference to the drawings. [A] According to the structure of claim 1, the tip end surface is formed on the gripping surface 4a as shown in FIGS. 3 (a) and 3 (b). Since the bellows 4 expands and contracts toward the object to be grasped, almost all the extension force of the bellows 4 acts on the object to be grasped as a grasping force.

[B] According to the structure of claim 2, as shown in FIG. 4, as the bellows 4 expands, the restraining portion 5 pulls and restrains a predetermined portion of the gripping surface 4a from the back side to grip the gripping surface 4a. The surface is curved.

[C] According to the structure of claim 3, as shown in FIGS. 6, 7, and 8, the wall thickness of the bellows of the first region 11 is made equal to the wall thickness of the bellows of the second region 12. Since the thickness is set thicker than that of the first area 1, the expansion amount of the bellows 4 in the second area 12 is
The curved surface 4 is larger than the extension amount of the first bellows 4, and in the extended state, the gripping surface 4a is curved from the tip side of one bellows 4 of the second region 12 to the tip side of the other bellows 4.
a.

[D] According to the structure of claim 4, as shown in FIGS. 9, 10, and 11, the bellows 4 of the first region 11 is formed.
Since the height of the pleats of the second area 12 is set to be lower than that of the folds of the bellows 4 of the second area 12,
The expansion amount of the bellows 4 becomes larger than the expansion amount of the bellows 4 of the first region 11, and in the expanded state, the gripping surface 4a changes from the tip side of one bellows 4 of the second region 12 to the tip side of the other bellows 4. It becomes a curved surface that curves over. [E] As a result, according to the constitutions of claims 2, 3, and 4, in addition to the same action as the action [A] according to the constitution of the above-mentioned claim 1, for example, a spherical object to be grasped, cucumber, carrot, etc. The grip surface, such as a long object to be gripped, can be set to a shape suitable for the object to be gripped, and the object to be gripped can be easily gripped.

[0013]

Therefore, according to the constitution of claim 1, it is possible to provide the robot hand capable of reliably grasping the object to be grasped with a small fluid pressure by the action [a]. According to the configuration of 4, it is possible to provide a robot hand capable of more reliably gripping an object to be gripped with a small fluid pressure by the above operations [b], [c], [d], and [e]. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a two-fingered robot hand according to the present invention. This robot hand is used for sorting the mandarin oranges harvested in the harvest basket into different harvest baskets according to grades such as size. , Central body part 2
a and a pair of connecting projections 2b on both sides thereof are suspended and supported by a supporting body 2, and a supporting arm for supporting the supporting body 2 is repositioned by a driving device (both not shown) to form the supporting member. 2 is configured to be close to and separated from the harvest basket side.

In the main body portion 2a of the support member 2, the connecting projections 2b, and the finger forming member 1, there are air passages R communicating with each other.
The first pump 3 is formed in the air supply / discharge port 10 on the tip side of the main body 2a of the support 2 in the air flow passage R.
A bag-shaped bellows made of soft rubber that connects (communicates with a fluid supply unit) and expands and contracts due to the supply and discharge of pressurized air from the first pump 3 at the opening on the tip end side of each finger formation body 1. Four
Are connected by thermal fusion. Each bellows 4 is laterally supported by the tip portion of the finger forming body 1 so as to expand and contract toward the gripping target side, and the tip surface of the bellows 4 is held by the gripping surface 4a.
It is formed in. Further, as the bellows 4 extends, the central portion of the gripping surface 4a is pulled from the back side to restrain the gripping surface 4a.
A rubber cord 5 serving as a restraining part for bending is formed integrally with the back surface of the bellows 4 in the bellows 4 and heat-sealed to the tip portion of the finger forming body 1.

The air flow passage R includes one main flow passage R1 extending from the front end side to the base end side of the support body 2 and a pair of sub flow passages which are respectively connected to communicate with the main flow passage R1 from the finger formation body 1 side. It consists of R2. In the main flow passage R1, in a state where both longitudinal end portions of the main flow passage R1 are shielded from the outside air,
A hollow support shaft 6 is inserted from the tip side of the support body 2, and a bellows-shaped suction nozzle N capable of adsorbing mandarin orange is connected to the tip of the support shaft 6, and the suction nozzle N is connected to the main body 2a.
1 provided between the seal ring 7 on the tip side of the
In FIG. 4, the both finger formations 1 are urged so as to project outward from the tip end portions thereof. The suction nozzle N is configured such that the air in the suction nozzle N is sucked by the second pump 20 from the hollow portion of the support shaft 6 so that it can be adsorbed to mandarin orange, and the air supply / discharge port communicating with the hollow portion of the support shaft 6 is provided. Air is discharged from (not shown) so that the adsorption action can be released.

The main flow passage R1 is a main body portion 2a of the support body 2.
The diameter of the support body 2 is reduced in the vicinity of the center to form the tip end side portion of the support body 2 in the cylinder chamber 8 with respect to the reduced diameter portion, while the intermediate portion of the support shaft 6 reciprocally slides in the cylinder chamber 8. The piston 9 is bulged.

The two auxiliary flow passages R2 branch off before the stroke end of the cylinder chamber 8, and as shown in FIG. 3, the pressurized air from the air supply / discharge port 10 causes the piston 9 to reach the stroke end. Then, the sucking nozzle N lifts a certain amount of mandarin orange, and then the two secondary flow passages R2 communicate with the air supply port 10, whereby the bellows 4 extends toward the mandarin orange side, and the gripping surface 4a at the tip makes the mandarin orange. Is configured to be gripped.

Further, the reduced diameter portion is formed to have a larger diameter than the portion corresponding to the piston rod on the base end side of the support shaft 6, and a gap S is formed between the reduced diameter portion and the support shaft 6 to support the support shaft 6. An air discharge port 22 is formed on the side wall of the base end of the body 2, and when the grip is released, the pressurized air in the bellows 4 is first discharged a little from the air supply / discharge port 10, and then the air discharge is performed. It is configured to discharge from the outlet 22. That is, when the pressurized air is discharged from the air supply / exhaust port 10, the support shaft 6 is moved to the finger tip side by the urging force of the spring 14, and the piston 9 immediately moves to the auxiliary flow passage R2 and the air supply / exhaust port 10. When the support shaft 6 is further moved to the tip side of the finger, the side flow passage R2 is closed by the air outlet 2
The pressurized air in the bellows 4 is discharged from the air discharge port 22 in communication with the air passage 2.

A control device 21 (an example of control means) capable of controlling the drive device, the first pump 3 and the second pump 20 is provided, and the robot hand having the above-mentioned configuration is provided with the control device 21.
Execution of the control of 1 operates as follows. [1] The support 2 is close to the side of the harvest basket. When the suction nozzle N adsorbs to the tangerine, the proximity drive of the support 2 to the tangerine side is stopped. (As a means for stopping the drive of the support 2, for example, based on the contraction amount of the suction nozzle N, the controller 21 is used. There is a means to stop and control the drive.

[2] As shown in FIG. 3 (a), pressurized air is supplied from the first pump 3 into the main flow passage R1, and the piston 9 resists the urging force of the spring 14 to the fingertip side. When pushed, the support shaft 6 is moved inward of the support body 2 to lift the mandarin orange to the gripping position. [3] As shown in FIG. 3B, the piston 9 reaches the stroke end, the secondary flow passage R2 and the air supply / discharge port 10 communicate with each other, and the bellows 4 expands with the pressurized air to grip the mandarin orange. (See also FIG. 2). Since the bellows 4 extends toward the tangerine side, the entire extension force of the bellows 4 can be used as the gripping force, and the tangerine can be reliably gripped with a small fluid pressure. Further, as the bellows 4 expands, the rubber band 5 pulls a predetermined portion of the gripping surface 4a from the back side to restrain and hold the gripping surface 4a (see FIGS. 4 and 5). As a result, mandarin oranges can be easily grasped. When the gripping force becomes constant, the supply of the pressurized air is stopped, and in this state, the support 2 is separated from the harvest basket side and one mandarin orange is taken out. [4] The finger forming body 1 is located above a predetermined position in the box to be newly accommodated, the pressurized air is discharged from the air supply / discharge port 10, and the gripping is started to be released. As the pressurized air is discharged, the elastic restoring force of the spring 14 causes the support shaft 6 to move to the finger tip side, and the piston immediately shuts off the side flow passage R2 and the air supply / discharge port 10. When the support shaft 6 further moves to the finger tip side,
The sub-flow passage R2 communicates with the air outlet 22, the pressurized air in the bellows 4 is discharged from the air outlet 22 through the gap S, and the bellows 4 contracts. When this grip is released, the suction nozzle N projects to the fingertip side to place the mandarin orange at a predetermined position in the box. The air in the suction nozzle N is discharged from the air discharge port that communicates with the hollow portion of the support shaft 6 to release the suction of mandarin oranges.

[Other Embodiments] The rubber string 5 may not be provided.

As shown in FIGS. 6, 7 and 8, the peripheral portion of the bellows 4 is provided with a pair of first regions 11 opposed to each other in the radial direction.
The bellows 4 of the first region 11 is divided into a pair of second regions 12 located between the first regions 11 and facing each other in the radial direction.
May be set thicker than the wall thickness of the bellows 4 of the second area 12, or as shown in FIGS. 9, 10 and 11, the folds of the bellows 4 of the first area 11 may be set. May be set lower than the height of the pleats of the bellows 4 of the second region 12.

According to this structure, the bellows 4 of the second area 12 is formed.
Can be made larger than the expansion amount of the bellows 4 of the first area 11, so that the gripping surface 4a extends from the tip side of one bellows 4 of the second area 12 to the tip side of the other bellows 4. It can be formed into a curved surface that bends,
For example, when gripping a long object such as cucumber, the grip can be ensured.

The object to be grasped may be vegetables or fruits other than mandarin oranges, and may be something other than food.

Instead of the pressurized air, the posture of the finger forming body 1 may be switched with a liquid such as pressurized hydraulic oil.

The bellows 4 may be formed of another member such as vinyl urethane instead of the rubber material.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the configuration of the accompanying drawings by this entry.

[Brief description of drawings]

[Fig. 1] Vertical front view of robot hand

FIG. 2 is a perspective view of a tip portion of the robot hand showing a grasped state.

FIG. 3A is a vertical cross-sectional front view of the robot hand showing a state in which the suction nozzle sucking the object to be grasped pulls the object to be grasped to the grasping position. Longitudinal front view of hand

FIG. 4 is a vertical sectional front view of the bellows in a gripping state.

FIG. 5 is a vertical sectional view of a bellows.

FIG. 6 is a vertical sectional front view of a main part of another embodiment.

FIG. 7 is a cross-sectional plan view of essential parts of another embodiment.

FIG. 8 is a vertical cross-sectional view of the main part of another embodiment.

FIG. 9 is a vertical sectional front view of a main part of another embodiment.

FIG. 10 is a cross-sectional plan view of the essential parts of another embodiment.

FIG. 11 is a vertical cross-sectional view of the main part of another embodiment.

[Explanation of symbols]

 1 Support Member 4 Bellows 4a Gripping Surface 5 Checking Member 11 First Area 12 Second Area

Claims (4)

[Claims] 1. A plurality of bag-shaped bellows (4) that expand and contract by the fluid pressure of fluid supplied to and discharged from an internal space are individually supported by a support member (1) so as to expand and contract toward the object to be grasped. do it,
A robot hand in which the tip surface of each bellows (4) is formed as a gripping surface (4a). 2. The bellows (4) is provided with a restraining part (5) that bends the tip gripping surface (4a) by pulling and restraining a predetermined portion of the tip surface from the back side as the bellows (4) extends. ) The robot hand according to claim 1, wherein the robot hand is provided inside. 3. A pair of first regions (11) that face each other in the radial direction, and a pair of first regions that face each other in the radial direction and are located between the first regions (11). The wall thickness of the bellows (4) of the first area (11) is set to be thicker than the wall thickness of the bellows (4) of the second area (12) by being divided into two areas (12). The robot hand according to claim 1. 4. A pair of first regions (11) opposed to each other in the radial direction and a pair of first regions opposed to each other in the radial direction on the periphery of the bellows (4). The height dimension of the folds of the bellows (4) of the first area (11) is divided into two areas (12) from the height dimension of the folds of the bellows (4) of the second area (12). Claims 1, 2,
The robot hand according to any one of 3 above.