JPH08197475A - Mechanical hand for manipulator - Google Patents

Abstract

PURPOSE: To provide a general purpose mechanical hand for a manipulator that can handle by gripping various workpieces of different outline shape stably by the same fingers without changing the fingers according to the shape of an object workpiece. CONSTITUTION: In an outline holding type mechanical hand 6 for holding a workpiece between a pair of fingers to grip it, the base body 14 of the finger 7 is formed of a hollow body of such constitution that a thin-walled flexible elastic film 14a of circular arc cross section forming the workpiece grip face, and a thick-walled reinforcing pad 14b are integrally formed of rubber group elastic material and that a closed cavity 14c is formed inward. An air pressure source 18 and a pressure regulating valve 17 are connected as pressure means for applying fluid pressure into the cavity of the finger base body 14 from the outside, and the workpiece 12 is gripped in the state of the finger base body 14 being expanded with air pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical hand for a manipulator which is mounted on a gantry loader, an industrial robot or the like to handle and convey a work.

[0002]

2. Description of the Related Art First, an automatic loader for loading, unloading, and transferring a work is equipped with a mechanical hand as shown in FIG.
FIG. 7 shows a conventional structure of a two-finger type translational mechanical hand (outer shape holding type). In FIG. 6, reference numeral 1 is a garter rail laid on the work transfer path, and 2 is a carriage that moves on the rail. The carriage 2 has a manipulator arm 4 vertically moved by a lifting motor 3 and a wrist at the tip of the manipulator arm 4. A mechanical hand 6, which is an object of the present invention, is mounted in combination with the swing mechanism 5.

Further, in FIG. 7, a translational mechanical hand 6 has a pair of left and right fingers 7 made of a rigid material coupled to a slider 9 guided and supported by a slide guide 8, and the slider 9 being a link mechanism. It is configured to be connected to the air cylinder 11 via 10, and the work 12 is gripped between the fingers 7 by operating the air cylinder 11 to interlock a pair of left and right fingers 7 in the arrow direction. As the mechanical hand, in addition to the translational type shown in the drawing, a swing type hand in which fingers are swingably opened and closed is also known.

[0004]

By the way, in the above-mentioned conventional mechanical hand, as shown in FIGS. 8 (a) to 8 (c), the workpiece 12 to be handled (round bar, square bar, or extruded section having an irregular shape). Specialized fingers designed and manufactured according to the outer shape of the molded product are used. Therefore, when handling a wide variety of works on the same assembly line of production equipment, each time the target work changes, the operation of the autoloader is stopped and the fingers 7 of the mechanical hand 6 are changed to the outer shape of the target work. It is necessary to replace it with a corresponding dedicated finger, which requires time and effort for the finger replacement, and it also results in lost time during the operation, which also affects the productivity of the assembly line.

The present invention has been made in view of the above points, and it is possible to stably grip various works having different outer shapes with the same finger attached without exchanging the fingers according to the shape of the target work. The purpose of the present invention is to provide a mechanical hand for a manipulator with high versatility that can be handled easily.

[0006]

In order to achieve the above object, the mechanical hand of the present invention has a work holding surface formed of a flexible elastic film having an arcuate circular cross section and having a work holding surface. A finger having a hollow body as a base body in which a closed cavity is formed inside the elastic film in combination with a reinforcing pad for limiting excessive deformation of the finger, and a pressurizing means for applying a fluid pressure to the inside of the finger cavity from the outside. The finger base is configured to be gripped by the work while the finger base is swollen by the pressurized fluid.

Further, the fingers described above can be specifically implemented in the following modes. 1) A plurality of elastic films are arranged to form a work gripping surface of fingers. 2) An elastic film forming a work gripping surface and a reinforcing pad are integrally molded to form a finger base.

3) The finger base is made of an elastic tube whose both ends are closed, and a part of the peripheral surface serving as a work gripping surface is projected to the front side to store and hold the elastic tube in the groove of the reinforcing pad. 4) The finger base is made of a rubber material.

[0009]

When the finger having the above-mentioned structure is mounted on a mechanical hand and a work is gripped in a state where the fluid such as air and oil is pressure-introduced from the outside into the cavity of the finger base to inflate the finger, the work holding surface of the finger is Since the elastic film forming the part elastically deforms in a concave shape at the contact portion with the work following the outer shape of the target work, various works having different outer shapes and works that are easily damaged or damaged by the applied pressure. However, it can be stably and safely gripped and handled freely by manipulating the manipulator.
Further, the work gripping surface of the elastic film is restrained by the reinforcing pad to prevent excessive deformation.

Moreover, by making the circular cross-section of the elastic film which becomes the work holding surface into an arc shape, the work holding surface can be surely fitted to various target works having different outer shapes, and the elastic film is further formed. By arranging a plurality of lines to form the work gripping surface of the fingers, the work is gripped in a more stable state. Further, by forming the work holding surface of the finger base with an elastic film made of a rubber material having a large friction coefficient, it is possible to prevent the work from slipping off the finger even if the clamping force of the finger is slightly weak.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIGS. 1 (a) to 1 (c) show a basic embodiment of the present invention, in which a pair of left and right fingers 7 is a core metal 13 which functions as a finger support arm, and the core. It is configured by combining with a finger base 14 of a hollow body made of a molded product of an elastic material such as rubber which is joined along the longitudinal direction of the gold 13, and the core metal 13 is an actuator mechanism of a mechanical hand (FIG. 7). Is connected to the slider 9). Here, the finger base 14
As shown in the cross-sectional views of FIGS. 1 (b) and 1 (c), a thin elastic film 14a having a circular cross-section that forms a workpiece gripping surface along the longitudinal direction of the finger and the elastic film 14a.
A cavity 14c having an arcuate cross-section is formed between the cavity 14c and a thick reinforcing pad 14b integrally formed with the cavity 14c, and both ends of the cavity 14c are sealed with seals 14d. Further, a fluid pressure introducing pipe 15 which is connected to the finger base in communication with the cavity 14c is connected to an air pressure source 18 via an air hose 16 and a pressure adjusting valve 17.

With such a structure, the air pressure is appropriately adjusted by the pressure adjusting valve 17 and the pressurized air is introduced into the cavity 14c to inflate the finger base 14, and in this state,
When the work 12 is sandwiched between the fingers 7 as shown in (a), the contact portion is elastically deformed into a concave shape so that the elastic film 14a serving as a gripping surface fits following the outer shape of the work 12 as illustrated. Then, the work 12 is gripped between the fingers 7. Accordingly, regardless of the outer shape of the work 12, the work of various shapes can be stably gripped by the same finger 7. In this case, even if the load applied to the elastic film 14a is large, as shown in FIG.
Is restrained by the reinforcing pads 14b opposed to each other across the cavity 14c to prevent excessive deformation, and the synergistic effect of this restraint and the clamping force of the mechanical hand enables stable holding of a heavy work without slipping off.

Second Embodiment: FIG. 3 shows an application example of the first embodiment, in which the finger base 14 is a reinforcing pad 14.
In common with b, the elastic membranes 14a having an arc-shaped cross section including the cavity 14c are arranged in two rows on the left and right along the longitudinal direction of the fingers to form a work holding surface. Although not shown, the finger base 14 is connected to the actuator mechanism of the mechanical hand via a cored bar. In addition, the left and right 2 formed inside the finger base 14
The strip cavity 14c is connected to an air pressure source via a pressure regulating valve as in the first embodiment.

By thus forming the work gripping surface with the two elastic films 14a arranged side by side, the supporting point of the work is doubled as compared with the single-row elastic film shown in the first embodiment. The work can be gripped in a stable posture. Third Embodiment: FIG. 4 shows another application example of the first embodiment. In this embodiment, the reinforcing pad 14b forming the finger base 14 has a U-shaped cross section, and a part of the work gripping surface is further forward from the front end surface 14e of the pad 14b across the inner wall surfaces of the reinforcing pad 14b. An elastic film 14a having an arcuate cross section is integrally formed so as to project.

With this structure, when the work is gripped, the elastic film 14a is deformed into a concave shape to sandwich the work between the fingers as described in FIG. 1, and a part of the peripheral surface of the work is the front end of the reinforcing pad 14b. It directly abuts on the surface 14e and is restrained in that position, and prevents the elastic film 14a from being excessively deformed. Embodiment 4: FIG. 5 shows still another embodiment of the present invention. In this embodiment, the finger base 14
A thin elastic tube 19 having a circular cross section with both ends closed,
Reinforcement pad 2 in which the elastic tube 19 is fitted and held in the groove
0, and a part of the peripheral surface of the elastic tube 19 projects forward from the reinforcing pad 20 to form a work gripping surface. If the reinforcing pad 20 is composed of a metal component that also serves as a finger supporting arm, the illustrated cored bar 13 becomes unnecessary.

[0016]

As described above, the structure of the present invention has the following effects. 1) Stable with the same fingers even for various works with different outer shapes (round bars, square bars, and works with irregular cross sections), and works that are easily damaged or damaged by pressure.
In addition, it can be gripped safely and freely handled by manipulator operation, which gives it high versatility, which eliminates the need for setup work to change the finger each time according to the shape of the target work like the conventional mechanical hand. Becomes Further, the work holding surface of the elastic film is restrained by the reinforcing pad to prevent excessive deformation, and the elastic film serving as the work holding surface has a circular cross section, so that various target works with different outer shapes can be obtained. Also, the work gripping surface can be surely fitted.

2) Further, by arranging a plurality of elastic films to form the work gripping surface of the fingers, the work can be gripped in a more stable state. 3) By forming the work holding surface of the finger base with an elastic film made of a rubber material having a large friction coefficient, it is possible to prevent the work from slipping off the finger even if the clamping force of the finger is slightly weak.

[Brief description of drawings]

FIG. 1 is a configuration diagram corresponding to a first embodiment of the present invention,
(A) is a diagram showing a workpiece gripping state Overall view of a canical hand, (b) and (c) are cross-sectional views of the finger in Fig. (A) and longitudinal sectional views, respectively.

FIG. 2 is a cross-sectional view showing elastic deformation of fingers in a work gripping state corresponding to FIG.

FIG. 3 is a cross sectional view of a finger corresponding to Example 2 of the present invention.

FIG. 4 is a cross sectional view of a finger corresponding to a third embodiment of the present invention.

FIG. 5 is a sectional view of a finger corresponding to Example 4 of the present invention.

FIG. 6 is a block diagram of an autoloader equipped with a mechanical hand that is the subject of the present invention.

7 is a configuration diagram of the mechanical hand in FIG.

FIG. 8 is a view exemplifying the shape of a target work-specific finger employed in a conventional mechanical hand, (a)
~ (C) shows the shape of dedicated fingers used for each target work with round bar, square bar, and irregular cross section.

[Explanation of symbols]

 6 Mechanical Hand 7 Finger 13 Core Bar 14 Finger Base 14a Elastic Membrane 14b Reinforcement Pad 14c Cavity 14d Cavity Seal Member 17 Pressure Control Valve 18 Air Pressure Source 19 Elastic Tube 20 Reinforcement Pad

Claims (5)

[Claims] 1. A mechanical hand for a manipulator which grips and handles a work from the outside by a plurality of fingers, wherein the work gripping surface is formed of a flexible elastic film having an arcuate cross section. Fingers based on a hollow body that forms a closed cavity inside the elastic membrane in combination with a reinforcing pad that limits excessive deformation of the work holding surface, and pressurization that applies external fluid pressure to the inside of the finger cavity A mechanical hand for a manipulator, comprising: means for gripping a work of various shapes having different outer shapes in a state where the finger base is swollen by a pressurized fluid. 2. A mechanical hand for a manipulator according to claim 1, wherein a plurality of elastic films are arranged to form a work gripping surface of a finger. 3. The mechanical hand for a manipulator according to claim 1, wherein an elastic film forming a work gripping surface and a reinforcing pad are integrally molded to form a finger base. . 4. The mechanical hand according to claim 1, wherein the base body of the finger is an elastic tube whose both ends are closed, and a part of the peripheral surface serving as a work gripping surface is projected to the front surface to form the elastic tube in the groove of the reinforcing pad. A mechanical hand for a manipulator, which is stored and held inside. 5. A mechanical hand for a manipulator according to claim 1, wherein the base body of the finger is made of a rubber material.