JPH08323676A - Robot hand - Google Patents

Abstract

PURPOSE: To take out objects to be gripped one by one smoothly and surely by communicating and connecting a negative pressure forming space of a sucker with a hollow section of a piston shaft and sucking air in the negative pressure forming space of the sucker through the hollow section. CONSTITUTION: A hollow section 6a of a support shaft 6 is communicated with a negative pressure forming space in a suction nozzle N, and air in the negative pressure forming space in the suction nozzle N is sucked from the hollow section 6a of the support shaft 6 by a second pump 20 so that it can be sucked on a cucumber. Air is exhausted from an air supply and exhaust port communicating with the hollow section 6a of the support shaft 6 so that the suction can be released. Two auxiliary stream passages R2 are branched before a first stroke end on a side where they are remote from the suction nozzle N in a cylinder chamber 8, and pressurized air from the air supply and exhaust port 10 pushes a piston 9 away up to the first stroke end so that the cucumber is lifted by the suction nozzle N by a certain amount. After the suction nozzle N is retracted, a finger form body 1 is bent on a belly section side to grip the cucumber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of finger forming members formed of a cylindrical soft material having a base end portion opened and a free end portion closed.
Dispersedly arranged around a support member, each base end is supported by the support member, the opening of the finger formation is connected to a fluid supply unit, and the fluid supply unit is supplied through the opening. The robot hand configured such that each finger formation is bent to the abdominal side by the fluid pressure.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned robot hand, as shown in Japanese Patent Application Laid-Open No. 61-203287, only each finger-formed body holds an object to be grasped.
Then, when holding the grasped object, each finger formation is kept open, positioned on both sides of the grasped object, and then bent toward the abdomen.

[0003]

For example, in the case of grasping and taking out one cucumber one by one from among a large number of laminated cucumbers, the adjacent cucumbers of the uppermost layer are in contact with each other at both sides and the surface of the uppermost layer is contacted. In the above conventional configuration, when the finger formations in the opened state are positioned on both sides of the cucumber, the tip of the finger formation hits the adjacent cucumber, and Was difficult to position on both sides, and it was troublesome to grip.

The object of the present invention is, even if the uppermost layers of adjacent objects to be grasped are in contact with each other on both sides as described above and the surfaces of the uppermost layers are substantially flat, the The object is to enable the grasped objects to be taken out smoothly and surely one by one.

[0005]

According to a first aspect of the present invention, there is provided a hollow piston shaft having a tip end provided with an adsorbent capable of adsorbing and releasing adsorption to an object to be grasped, and a piston of the piston shaft. The support member is provided with a piston mechanism including a cylinder chamber capable of acting a fluid pressure from the tip end side of the piston shaft toward the base end side, in a state in which the adsorbent projects from the support member toward the gripping target, A protrusion actuating means for moving the piston shaft in a direction in which the adsorbent projects from the support member while discharging the pressurized fluid from the cylinder chamber is provided, and the adsorbent is supplied and discharged to and from the cylinder chamber. A protruding state in which each finger forming body is protruded to the outside of the fingertip portion in a grip release posture so that it can be adsorbed to the grasping object, and an object grasped by each finger forming body while being adsorbed to the grasping object. A fluid flow hole provided near the first stroke end on the side far from the adsorbent in the cylinder chamber, which is configured to be freely switchable to a retracted state in which the fingertip portion is retracted to a position where it can be held. Is connected to the opening of the finger forming body so that the suction body is in the retracted state or a state close to the retracted state, and then the opening is communicated with the fluid intake port in the cylinder chamber, The finger forming body is configured to bend to the abdomen side, the negative pressure forming space of the adsorbent body and the hollow portion of the piston shaft are connected in communication, and the negative pressure forming of the adsorbent body is performed through the hollow portion. It is configured to suck the air in the space.

According to a second aspect of the present invention, in the first aspect of the invention, the piston is formed at an intermediate portion in the longitudinal direction of the piston shaft, and the end portion of the cylinder chamber on the first stroke end side. The piston shaft is gently inserted from the base end side into the piston shaft insertion hole formed in, and as the piston moves from the first stroke end side to the other second stroke end side, the opening portion is formed. Is communicated with the gap between the piston shaft and the piston shaft insertion hole, and the pressurized fluid in the finger forming body is discharged from this gap.

[0007]

According to the constitution of claim 1, the following effects can be achieved. For example, when a large number of cucumbers are stacked and the adjacent cucumbers in the uppermost layer are in contact with each other at both sides and the surfaces of the uppermost layers are substantially flat, the adsorbent first moves each finger in the grip release posture. It sticks to one cucumber while protruding outward from the fingertips of the formed body. Next, the fluid is supplied to the cylinder chamber, and the fluid pressure is applied to the piston from the tip side of the piston shaft to the base side, and the adsorbent adsorbed on the cucumber is located inward from the finger tips of each finger formation. Move to.
Then, after the adsorbent is in the retracted state or in a state close to the retracted state, the opening of the finger forming body communicates with the fluid intake port in the cylinder chamber, and each finger forming body is bent to the abdomen side by the fluid pressure. Hold the cucumber.

Since the cucumbers are gripped in this manner, even if the adjacent cucumbers in the uppermost layer are in contact with each other at both sides and the surfaces of the uppermost layer are substantially flat, the finger formations are You can avoid hitting the next cucumber.

As a structure in which the adsorbent can be switched between the projecting state and the retracted state, for example, a support shaft provided with the adsorbent at the tip is placed in a state in which the adsorbent projects from the support member toward the object to be grasped. There is also a structure in which the feed screw mechanism is inserted between the support member and the support shaft, and the screw mechanism is operated by an electric motor attached to the support member to move the suction member out of the support member. Not inconceivable. However, in this structure, since the electric motor and the screw mechanism are provided, the apparatus becomes large and heavy. Further, in this structure, if the finger-shaped body is configured to bend to the abdominal side after the adsorbent is in the retracted state or a state close to the retracted state, a sensor and a control for detecting the retracted state and the like are provided. A device must be provided to control each finger formation so that it bends toward the abdomen based on the detection result of the sensor, and such a control method complicates the control. On the other hand, in the configuration of claim 1, the piston mechanism is provided in the support member, and the fluid flow hole provided near the first stroke end on the side farther from the adsorbent in the cylinder chamber communicates with the opening of the finger forming body. After the connection is made and the adsorbent is in the retracted state or a state close to the retracted state, the opening is communicated with the fluid intake port in the cylinder chamber, and each finger formation is bent to the abdomen side. Therefore, it is possible to avoid the increase in size and weight of the structure including the feed screw mechanism, the electric motor, and the like as described above, and it is possible to prevent the control from becoming complicated.

Then, the negative pressure forming space of the adsorbent and the hollow portion of the piston shaft are connected in communication with each other, and the air in the negative pressure forming space of the adsorbent is sucked through the hollow portion. Therefore, as when a hose for sucking air in the negative pressure forming space is newly provided around the support member,
The hose does not get caught on other objects for excellent workability, and the number of parts can be reduced to simplify the structure.

According to the configuration of claim 2, in addition to the same operation as that of claim 1, the pressurized fluid in the finger forming body can be smoothly discharged. Since the piston shaft is gently inserted from the base end side into the piston shaft insertion hole formed in the end portion of the cylinder chamber on the first stroke end side, the piston shaft is in contact with the piston. Side wall,
It is supported at two points with the end of the cylinder chamber on the other side of the second stroke end. For example, the piston shaft is slidably inserted from the base end side into the piston shaft insertion hole to contact the piston. As shown in the case of supporting at three points, the side wall of the cylinder chamber and the ends of the cylinder chambers on both the first and second stroke ends, the piston shaft supporting force is unsatisfactory at each supporting point due to manufacturing errors. It is possible to avoid becoming uniform and to make it difficult to deform the piston shaft.

[0012]

As described above, according to the first aspect of the invention, when the gripping objects are taken out one by one from among a large number of stacked gripping objects, the gripping objects adjacent to each other in the uppermost layer have both sides. Even if the surfaces of the uppermost layer are in contact with each other and are almost planar, the object to be grasped can be taken out smoothly and reliably, and the structure can be made compact and lightweight. It was possible to provide a robot hand that can be controlled and can be easily controlled.

According to the structure of claim 2, in addition to the effect of the structure of claim 1, the pressurized fluid in the finger forming body can be smoothly discharged, and the piston shaft and the like can be made difficult to deform. Therefore, it is possible to provide a robot hand that can be controlled accurately and can be improved in durability.

[0014]

An embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, a finger forming body 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 configured to be supported by a support member 2 corresponding to a palm. A two-fingered robot hand is shown. This robot hand is used to sort the cucumbers harvested in the harvest basket into different boxes according to grades such as size. The support arm that supports the support member 2 at the tip portion is a drive device (both together). By changing the position (not shown), the support member 2 is configured to be closely spaced to the harvest basket side.

Each finger formation 1 has its end portion on the side of the opening 1a externally fitted to a pair of connection end portions projecting from the support member 2 and fixed by a ring-shaped clip 5. . Further, one of the pair of connecting ends is divided from the main body of the support member 2 and is bolt-connected to the main body so that the direction and length of the one finger forming body 1 are It is configured so that it can be changed and adjusted to match the direction and length of the other finger formation 1. The opening 1a of the finger body 1 is connected to an air flow passage R formed in the support member 2 so as to communicate with the air flow passage R.
The first pump 3 (an example of a fluid supply unit) is connected to the air supply / exhaust port 10 (an example of a fluid intake port) on the front end side of the support member 2 in FIG. The bellows 18 is formed so that the height dimension of each fold is higher toward the back side of the finger forming body 1 (see FIG. 4), and each finger forming body 1 is moved to the abdominal side by supplying and discharging pressurized air from the first pump 3. The posture of each finger forming body 1 can be freely switched between a grasping posture that is bent in a vertical direction and a grasping releasing posture that returns and extends to the back side.

The air flow passage R has one main flow passage R1 extending from the front end side to the base end side of the support member 2 and a pair of sub-flow passages branching from the main flow passage R1 and respectively communicating with the opening 1a. It is composed of a flow passage R2, and in the main flow passage R1,
The hollow support shaft 6 is inserted from the front end side of the support member 2 in a state where both longitudinal ends of the main flow passage R1 are shielded from the outside air. The support shaft 6 supports a bellows-shaped suction nozzle N (an example of a suction body) capable of suctioning cucumber by a protruding tip portion.

The intermediate portion of the support shaft 6 is connected to the piston 9
The support shaft 6 is formed into a bulge to form a piston shaft,
On the other hand, the main flow passage R1 is reduced in diameter in the vicinity of the center of the support member 2, and the tip side portion of the support member 2 with respect to the reduced diameter portion (an example of a piston shaft insertion hole) is attached to the piston 9 at the tip of the support shaft 6. Chamber 8 that can apply pressure from the side to the base end
It is formed on. Further, the suction nozzle N is attached to the support member 2
1 provided between the seal ring 7 on the tip side of the
In 4, the suction nozzle N is gripped so that it can be adsorbed by the cucumber by urging it in a direction projecting outward from the tip of the two-finger formation 1 and supplying and discharging pressurized air to and from the cylinder chamber 8. In the released posture, each finger formation body 1 protrudes outward from the fingertip portion of each finger formation body 1 and each finger formation body 1 while being adsorbed on the cucumber.
It is configured such that it can be switched to a retracted state in which the cucumber is gripped by the claw so as to be inward of the fingertip portion. The support shaft 6 and the cylinder chamber 8 form a piston mechanism A.

The hollow portion 6a of the support shaft 6 and the suction nozzle N
The hollow portion 6a of the support shaft 6 is communicated with the negative pressure forming space therein.
The air in the negative pressure forming space in the suction nozzle N from the second
The pump 20 is configured to be sucked and adsorbed on cucumber, and the adsorption action can be released by discharging air from an air supply / discharge port (not shown) communicating with the hollow portion 6a of the support shaft 6.

The two sub-flow passages R2 branch off before the first stroke end on the side far from the suction nozzle N of the cylinder chamber 8, and as shown in FIG.
Pressurized air from 0 pushes the piston 9 to the first stroke end, causes the suction nozzle N to lift a certain amount of cucumber, and after the suction nozzle N is in the retracted state, the two auxiliary flow passages R2 are air-cooled. It is configured to communicate with the supply port 10, whereby the finger formation 1 is bent toward the abdomen, and holds the cucumber. A fluid passage hole is formed at a portion of the auxiliary flow passage R2 on the cylinder chamber 8 side.

The reduced diameter portion is formed to have a diameter larger than that of the base end side portion of the support shaft 6, and a gap S is formed between the reduced diameter portion and the support shaft 6, and the base end side wall of the support member 2 is formed. When the air discharge port 22 is formed and the gripping of the finger formation body 1 is released, the pressurized air in the finger formation body 1 is first discharged a little from the air supply / discharge port 10, and thereafter the air discharge port is released. It is configured to discharge from 22. That is, as the pressurized air is discharged from the air supply / discharge port 10 and the piston 9 is moved from the first stroke end side to the other second stroke end side by the urging force of the spring 14, the piston 9 moves. When the sub-flow passage R2 and the air supply / exhaust port 10 are shut off and the piston 9 further moves to the finger tip side, the opening 1a and the sub-flow passage R2 communicate with the air exhaust port 22, and the finger forming body 1 is formed. The pressurized air inside is discharged from the gap S / air discharge port 22. The spring 14 and the mechanism for discharging the pressurized air from the cylinder chamber 8 constitute a protrusion actuating means B for moving the support shaft 6 in the direction in which the suction nozzle N projects from the support member 2.

A pair of fins 4 extending outward in the width direction are formed on the fingertips of each finger formation 1 (see FIG. 3) so that the cucumber can be reliably gripped with two fingers. As shown in FIGS. 1 and 4, the lead wire 15 is drawn from the support member 2 side into a groove formed in the abdomen along the longitudinal direction, and the first pressure-sensitive sensor 16 is provided on the distal end surface of the finger formation 1 and the abdomen. And a second pressure sensor 17 are provided separately (see FIG. 5). The second pressure-sensitive sensor 17 is an elastic pressure-sensitive sensor made of rubber, and the elastic pressure-sensitive sensor forms a grip surface.

The first and second pressure-sensitive sensors 16,
Based on the detection result of 17, the drive device, the first pump 3,
A control device 21 (an example of control means) capable of controlling the second pump 20 is provided.

The robot hand having the above-mentioned configuration is used in the control device 2
Execution of control No. 1 operates as follows. [1] The support member 2 approaches the harvest basket side. Suction nozzle N
Is adsorbed on one cucumber, the proximity drive of the support member 2 to the cucumber side is stopped (see FIG. 1. As means for stopping the drive of the support member 2, for example, based on the contraction amount of the suction nozzle N, There is a means of controlling the drive device to stop by the control device 21). In this case, when the tip portion of the finger forming body 1 comes into contact with something other than cucumber, for example, and a pressing force of a certain amount or more is applied, the first pressure-sensitive sensor 16 detects that the pressing force is applied, Based on this detection information, the proximity drive of the support member 2 to the cucumber side is stopped, and the finger formation body 1 is prevented from being damaged.

[2] Pressurized air is supplied from the first pump 3 into the cylinder chamber 8 of the main flow passage R1, the piston 9 receives the air pressure directed to the side opposite to the fingertip side, and the support shaft 6 moves to the spring 14. It moves inward of the support member 2 against the urging force, and lifts a certain amount of cucumber.

[3] As shown in FIG. 2, the piston 9 reaches the stroke end and is in the retracted state, the auxiliary flow passage R2 and the air supply / discharge port 10 communicate with each other, and the finger body 1 is pressed. Bend to the abdomen with air and hold the cucumber. When the second pressure-sensitive sensor 17 detects that the gripping force has become constant, the supply of pressurized air is stopped, the air pressure inside the finger forming body 1 becomes constant, and the bending operation stops. In this state, the support member 2 is separated from the harvest basket side and one cucumber is taken out.

[4] The finger-formed body 1 is located above a predetermined position in the box to be newly accommodated, and the pressurized air is discharged from the air supply / discharge port 10 so that the finger-formed body 1 releases the grip. start. 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 9 immediately shuts off the auxiliary flow passage R2 and the air supply / discharge port 10. Support shaft 6
When the finger moves to the tip side of the finger, the secondary flow passage R2 communicates with the air discharge port 22, and the pressurized air in the finger forming body 1 moves to the gap S.
Is discharged from the air discharge port 22 and the finger formation 1 returns to the grip release posture and extends. When this grip is released, the suction nozzle N projects toward the fingertip side and places the cucumber on the predetermined position in the box. The air in the suction nozzle N is discharged from the air discharge port communicating with the hollow portion 6a of the support shaft 6 to release the suction of the cucumber.

[Other Embodiments] The finger forming body 1 may be formed of another soft material such as vinyl urethane instead of the rubber material.

The object to be grasped may be vegetables or fruits other than cucumber, or may be something other than food.

Three or more finger forming bodies 1 may be provided.

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

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

[Brief description of drawings]

FIG. 1 is a front view of a partially cutaway robot hand before gripping.

FIG. 2 is a partial cutaway front view of a robot hand showing a gripping operation.

FIG. 3 is a rear view of the tip portion of the finger forming body.

FIG. 4 is a cross-sectional view of a bellows portion of a finger body.

FIG. 5 is a cross-sectional view of a finger formation body.

[Explanation of symbols]

 1 Finger Forming Body 1a Opening Part 2 Supporting Member 3 Fluid Supply Part 6 Piston Shaft 6a Hollow Part 9 Piston 8 Cylinder Chamber 10 Fluid Intake Port A Piston Mechanism B Projection Actuating Means N Adsorbing Body S Gap

Claims (2)

[Claims] 1. A plurality of finger forming bodies (1) formed of a cylindrical soft material having a base end portion opened and a free end portion closed, are dispersedly arranged around a support member (2), and each base is formed. An end portion is supported by the support member (2), and an opening portion (1a) of the finger forming body (1).
Is fluidly connected to the fluid supply part (3), and the opening part (1a)
A robot hand configured such that each finger formation (1) is bent to the abdominal side by the pressure of the fluid supplied from the fluid supply section (3) through the A hollow piston shaft (6) provided with a releasable adsorbent (N) at its tip, and a fluid flowing from the tip end side of the piston shaft (6) to the base end side of the piston (9) of this piston shaft (6). A piston mechanism (A) including a cylinder chamber (8) capable of exerting pressure is provided on the support member (2) in a state in which the adsorbent (N) projects from the support member (2) toward the gripping target. A protrusion actuating means (B) for moving the piston shaft (6) in a direction in which the adsorbent (N) protrudes from the support member (2) while discharging the pressurized fluid from the cylinder chamber (8). Provided,
By supplying / discharging the fluid to / from the cylinder chamber (8), the adsorbent (N) is made to protrude to the outside of the fingertips of the finger forming bodies (1) in the grip release posture so that the adsorbent (N) can be adsorbed to the object to be grasped. It can be switched between a protruding state and a retracted state in which the finger-shaped body (1) is retracted inward of the fingertip portion to a position where the finger-shaped body (1) can grasp the grasped object while being attracted to the grasped object. A fluid flow hole provided in the cylinder chamber (8) near the first stroke end on the side far from the adsorbent (N) is connected to the opening (1a) of the finger forming body (1). Then, after the adsorbent (N) is in the retracted state or in a state close to the retracted state, the opening (1a) communicates with the fluid intake port (10) in the cylinder chamber (8), The formed body (1) is configured to be bent toward the abdomen, and the adsorbent (N Of the negative pressure forming space of the adsorbent (N) is connected to the hollow portion (6a) of the piston shaft (6) so as to communicate the air in the negative pressure forming space of the adsorbent (N). A robot hand configured to suck. 2. The piston (9) is formed at an intermediate portion in the longitudinal direction of the piston shaft (6), and a piston shaft insertion hole is formed at an end of the cylinder chamber (8) on the first stroke end side. , The piston shaft (6) is gently inserted from the base end side, and the piston (9) is moved to the first side.
With the movement from the stroke end side to the other second stroke end side, the opening (1a) communicates with the gap (S) between the piston shaft (6) and the piston shaft insertion hole, The robot hand according to claim 1, wherein the pressurized fluid in the finger forming body (1) is discharged from the gap (S).