JPH0938882A - Robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a hold object by a small fluid pressure surely by supporting a nozzle mechanism for pulling the hold object to a position holdable by each finger form body by a support member inside each finger form body. SOLUTION: A suction nozzle N in close proximity to a cucumber is sucked to the cucumber by the drive of a third cylinder C3. In a state where the finger back side space S1 of a finger form body 1 is free to discharge fluid, a second cylinder C2 supplies a pressurized air in a belly side space S2 and the finger form body 1 becomes in a hold object receiving posture folded to the finger back side. The cucumber is drawn in a hold position by the shrinkage of the suction nozzle N by the increase of inside negative pressure. When the cucumber is positioned in a hold position, in a state where the finger belly side space S2 of the finger form body 1 is free to discharge fluid, a first cylinder C1 supplies fluid to a finger back side space S1 and holds the cucumber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supports a plurality of finger forming bodies formed of a cylindrical soft material having a base end portion opened and a free end portion closed, by a supporting member, and the opening portion of the finger formation body. The present invention relates to a robot hand in which each finger forming body is configured to be bendable by supplying and discharging a fluid to and from the internal space of the finger forming body.

[0002]

2. Description of the Related Art Conventionally, as the above robot hand,
For example, as shown in Japanese Patent Laid-Open No. 61-203287,
The back side of the finger forming body is formed in a bellows shape as a whole, and when gripping an object to be grasped, each finger in a non-grasping state is configured so that each finger forming body can receive the object to be grasped in the initial posture. In some cases, the gap between the gripping portions of the formed body is set wide. In this configuration, the bellows is extended by the fluid pressure in the finger formation body, and the extension force causes the finger formation body to bend to the abdomen side to grasp the grasped object.

[0003]

However, according to the above-mentioned conventional structure, the finger forming body is bent only by the extension force of the bellows, and the acting direction of the extension force of the bellows changes from the gripping direction. Therefore, in order to reliably grasp the object to be grasped, the fluid pressure has to be increased considerably.

An object of the present invention is to provide a robot hand which can reliably grip an object to be gripped with a small fluid pressure.

[0005]

[Means for Solving the Problems]

[Structure] The characteristic structure of the invention according to claim 1 is such that, when gripping an object to be gripped, each finger-formed body is separated from each other so as to receive the object to be grasped, the gripping portion of each finger-formed body in a non-grip state. The interval between them is set to be narrow, and a partition wall for partitioning the internal space of the finger forming body into a space on the finger back side and a space on the finger pad side is formed on the finger forming body, and the space on the back side of the finger and the space on the finger pad side. Is connected to the fluid supply / drain portion separately, and one of the finger back side space and the finger pad side space is in a fluid supply state, and the other side is in a fluid dischargeable state,
Grips on the outer side of each finger formation are configured so that they can be switched between a grasping posture in which the finger formation is bent toward the finger pad side and a grasping object receiving posture in which the finger formation is bent toward the back of the finger. A nozzle mechanism that attracts a suction nozzle to an object and draws the grasped object to a position where it can be grasped by each finger forming body is supported by the supporting member inside each finger forming body. .

According to a second aspect of the present invention, in the invention according to the first aspect, in the nozzle mechanism, the suction nozzle is formed in a bellows shape, and the suction nozzle sucked on an object to be grasped. The length of the suction nozzle is set so that the object to be gripped is drawn into the gripping position by contracting with a negative pressure in the suction nozzle.

According to a third aspect of the present invention, in the invention according to the first or second aspect, a detent groove for preventing the suction nozzle from swinging in the radial direction is provided in the grip portion of each finger forming body. It is formed according to the outer shape of the suction nozzle.

[Operation] In the structure of claim 1, the object to be gripped is gripped by the following procedure, for example. That is, FIG. 1 and FIG.
As shown in (a), the third cylinder C3 is driven so that the suction nozzle N close to the gripping target sticks to the gripping target, and as shown in FIG. 3B, the finger back space S1. In a state in which the fluid can be discharged freely, the second cylinder C2 (an example of a fluid supply / discharge portion) supplies fluid to the abdomen side space S2, and the finger formation body 1 is bent to the back of the finger to receive the grasped object receiving posture. become. Then, as shown in FIG. 4C, the third cylinder C
By the drive of 3, the suction nozzle N pulls the gripping object to a position where it can be gripped by each finger forming body 1, and as shown in FIG. Then, the first cylinder C1 supplies the fluid to the space S1 on the back of the finger, and each finger formation 1 grips the grip target. When the gripping of the gripping target is released, the finger formation 1 is placed in the gripping target receiving posture, the suction of the gripping target by the suction nozzle N is released, and the gripping is released.

According to the structure of claim 1, [a] the spacing between the gripping portions of the finger-formed bodies in the non-grasping state is set to be narrow so that the finger-formed bodies are separated from each other to receive the object to be grasped. Therefore, it is possible to add the elastic restoring force to the grasping object side of the entire finger-formed body in the fluid supply state to the grasping force, and to increase the grasping force by the elastic restoring force as compared with the conventional one. it can.

[B] Since the above-mentioned nozzle mechanism is supported by the supporting member inside each finger forming body, for example, from a large number of laminated cucumbers (an example of an object to be grasped), cucumbers are used. When the cucumbers are picked up one by one and the cucumbers adjacent to each other in the uppermost layer are in contact with each other at both sides and the surface of the uppermost layer is substantially flat, the suction nozzles are formed into the fingers in the grip release posture. Stick it to the target cucumber by projecting it to the outside of the fingertips of the body and pulling it inward from the fingertips of each finger formation while adsorbing it in that way. Can hold cucumber,
It is possible to prevent each finger formation from hitting an adjacent cucumber during gripping.

According to the second aspect of the present invention, in addition to the same actions as the above-mentioned actions [A] and [B], the suction nozzle is formed in a bellows shape and sucked onto the object to be gripped. However, since the length of the suction nozzle is set so that the object to be gripped is drawn into the gripping position by contracting due to the negative pressure in the suction nozzle, for example, a piston mechanism is provided in the nozzle mechanism. The structure can be simplified as compared with the case in which the object is grasped and the object to be grasped is drawn to a position where it can be grasped by each finger formation body.

According to the configuration of claim 3, [d] the above-mentioned swing-stopping groove for preventing the swinging of the suction nozzle in the radial direction is formed in the grip portion of each finger forming body. In addition to the operations [a], [b], and [c], the suction nozzle can be surely sucked without diverting the suction nozzle from the object to be gripped. In particular, when the structure of the present invention is adopted in the structure of claim 2, the suction nozzle can be surely sucked to the object to be gripped, although the length of the suction nozzle is long.

[Effect] Therefore, according to the configuration of claim 1, the robot hand capable of reliably grasping the object to be grasped with a small fluid pressure by the action [a] and improving workability by the action [b]. Could be provided.

According to the structure of claim 2, in addition to the effect of the structure of claim 1, a compact structure can be obtained by the action [C].

According to the configuration of claim 3, in addition to the effect of the configuration of claim 2 or 3, due to the action [d]
It was possible to improve workability.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a finger member 1 formed of an elongated tubular rubber material (an example of a soft material) having a base end portion opened and a free end portion closed is supported by a support member 2, and an internal space of the finger member 1 is formed. 2 shows a two-fingered robot hand in which each finger formation 1 can be bent by supplying and discharging pressurized air.
This robot hand is used to sort cucumbers (an example of objects to be gripped) harvested in a harvest basket into different harvest baskets according to grades such as size. The position of the supporting arm to be supported is changed by a driving device (both not shown) so that the supporting member 2 is moved toward and away from the other harvest basket side.

Each finger-formed body 1 has a longitudinal intermediate portion formed in a bellows shape so that the gripped portions of the finger-formed bodies 1 in the non-grasping state are spaced apart from each other by the finger-formed bodies 1. With a narrow setting so as to receive cucumber, the ends on the opening side are individually fitted onto a pair of connecting round bosses 2a provided at both corners of the bottom of the supporting member 2 to form a ring-shaped clip. It is fixed at 8. Then, a partition wall 3 that vertically divides the internal space S of the finger forming body 1 into a finger back side space S1 and a finger pad side space S2 is formed in the finger forming body 1, and the finger back side space S1 and the finger pad side space S2 are formed. Are connected to a pair of air flow passages R in the support member 2 separately, and are connected to the respective air flow passages R so as to communicate with each other.
With the second air cylinders C1 and C2 (an example of a fluid supply / discharge unit),
Grip in which the finger formation body 1 is bent to the finger pad side by setting one of the finger back side space S1 and the finger pad side space S2 to a fluid supply state and the other side to a fluid dischargeable state The posture is freely switchable between the posture and the posture for receiving the grasped object bent to the back of the finger.

Further, a nozzle mechanism 4 for attracting a bellows-like suction nozzle N made of a soft material to the cucumbers on the outer side of each finger forming body 1 and pulling it to a position where each finger forming body 1 can hold it. ,
It is supported by the support member 2 inside each finger formation 1.

The nozzle mechanism 4 has a hollow support shaft 5 which is fixed through the center of the support member 2 from the base end side toward the tip end side.
The suction nozzle N is communicatively connected to the tip of the finger so that the nozzle tip projects from the tip of each finger body 1,
The base end of the hollow support shaft 5 is communicatively connected to the third air cylinder C3 so that the air in the negative pressure forming space in the suction nozzle N is sucked by the third cylinder C3. The suction nozzle N is configured such that the entire length thereof is set to be long, and the cucumber is attracted to the gripping position by contracting with a negative pressure in the suction nozzle N in a state of being adsorbed on the cucumber. . As shown in FIG. 2, the grip portion of each finger forming body 1 is formed with a stop groove 6 for preventing the suction nozzle N from swinging in the radial direction in accordance with the outer shape of the suction nozzle N. is there.

A control device 7 capable of controlling the drive device, the first, second, and third cylinders C1, C2, C3 is provided, and the robot hand having the above-mentioned structure moves the cucumber on the upper side of the cucumber as follows. And hold.

[1] The suction nozzle N close to the cucumber sucks the cucumber by driving the third cylinder C3 (see FIG. 3).
(I)). [2] The second cylinder C2 supplies pressurized air to the abdomen side space S2 in a state in which the finger back space S1 of the finger formation body 1 can be discharged freely, and the finger formation body 1 is folded to the finger back side. The bent object to be grasped is in the posture of receiving (FIG. 3B).

[4] The suction nozzle N contracts due to an increase in the negative pressure inside, and draws the cucumber into the gripping position (FIG. 4).
(C)). [5] When the cucumber is located at the gripping position, the first cylinder C1 supplies fluid to the finger back space S1 in a state in which the finger pulp side space S2 of the finger forming body 1 can be discharged, and grips the cucumber. (Fig. 4 (d)). [4] When the cucumber is released from the grip, the finger formation 1 is bent to the back of the finger to receive the object to be gripped, the suction of the suction nozzle N is stopped, and the cucumber is released from the grip.

[Other Embodiments] The object to be grasped may be vegetables or fruits other than cucumber, or may be something other than food. Instead of the pressurized air, the posture of the finger forming body 1 may be switched by a liquid such as pressurized hydraulic oil.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations 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 essential parts of a finger forming body and a nozzle mechanism.

FIG. 3 (a) is a vertical cross-sectional front view showing a state in which a suction nozzle is sucked onto a grasped object. (B) A vertical cross-sectional front view showing a state in which each finger formation is in a grasped object receiving posture.

FIG. 4C is a vertical cross-sectional front view showing a state in which the suction nozzle draws the grip target to the grip position. (D) A vertical cross-sectional front view showing a state in which each finger forming body is in a gripping posture.

[Explanation of symbols]

 1 Finger Forming Body 2 Support Member 3 Partition Wall 4 Nozzle Mechanism 6 Swing Groove C1, C2 Fluid Supply / Discharge Portion S Internal Space S1 Finger Back Side Space S2 Finger Abdominal Side Space N Adsorption Nozzle

Claims (3)

[Claims] 1. A finger forming body (1) supported by a supporting member (2), comprising a plurality of finger forming bodies (1) made of a cylindrical soft material having a base end portion opened and a free end portion closed. A robot hand in which each finger formation body (1) is configured to be bendable by supplying and discharging a fluid from the opening of the finger formation body (1) into the internal space of the finger formation body (1). In doing so, the spacing between the gripping portions of the finger-formed bodies (1) in the non-grasping state is set to be narrow so that the finger-formed bodies (1) are separated from each other to receive the gripping target. A partition wall (3) for partitioning the internal space (S) of 1) into a finger back side space (S1) and a finger pad side space (S2) is formed in the finger formation body (1), and the finger back side space ( The fluid supply / drainage section (C
1) and (C2) are separately connected to each other so that one of the finger back side space (S1) and the finger pad side space (S2) is in a fluid supply state and the other side is in a fluid dischargeable state. By doing so, the finger formation body (1) is configured to be freely switchable between a grasping posture in which the finger pad side is bent and a grasping object receiving posture in which the finger forming body is bent toward the finger back side. A nozzle mechanism (4) for attracting the gripping target (N) to the gripping target on the outer side of the body (1) and pulling the gripping target to a position that can be gripped by each finger formation (1). A robot hand, which is supported by the support member (2) inside each finger formation (1). 2. In the nozzle mechanism (4), the suction nozzle (N) is formed in a bellows shape, and the suction nozzle (N) sucked on an object to be gripped is the suction nozzle (N).
The robot hand according to claim 1, wherein the length of the suction nozzle (N) is set such that the object to be grasped is drawn into the grasping position by contracting with a negative pressure inside. 3. A holding groove (6) for preventing the suction nozzle (N) from swinging in the radial direction is provided in the grip portion of each finger forming body (1) in the outer shape of the suction nozzle (N). The robot hand according to claim 1, wherein the robot hand is formed together.