JPH05337870A - Grip device for manipulator - Google Patents

Abstract

PURPOSE:To enable the execution of plural different kinds of work contents with a high accuracy so as to improve the handling operability. CONSTITUTION:The first to third links 15, 17, 19 of link mechanism for driving fingers 16 into the opened/closed state are accommodated in a housing 18, and this housing 18 is fitted to a manipulator base part 10 through a connecting member 20 connected elastically or rigidly, selectively according to the operating positions of the first to third links 15, 17, 19 (the grip force of the fingers 16). When a motor 11 is rotatory-driven to operate the first to third links 15, 17, 19 so that the fingers 16 are driven into the closed state, the connecting member 20 is connected elastically or rigidly according to the first to third links 15, 17, 19 (the grip force of the fingers 16), and elastic grip or rigid grip is changeover-set to accomplish the expected purpose.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripping device used in a manipulator constructed in outer space, for example.

[0002]

2. Description of the Related Art As is well known, in the field of space development, there is a concept of constructing a so-called space station in which human beings can reside in space, so-called space station. In such a space station construction concept, it is said that a manipulator system using a manipulator that carries out transportation of construction materials in place of a human is effective. A manipulator used in such a manipulator system is provided with a gripping device for holding an object to be gripped, as an end factor thereof. As this gripping device, a plurality of fingers, for example, two or three fingers, for gripping an object to be gripped are arranged on a manipulator base via a link mechanism, and a ball screw mechanism is connected to the link mechanism. Then, the rotational force of the rotary drive motor is transmitted to the ball screw mechanism, and the rotational force from the rotary drive motor is converted into a linear motion and transmitted to the link mechanism. The link mechanism is operated in conjunction with the drive of the ball screw mechanism,
The fingers are opened and closed to hold and release the object to be held.

By the way, in such a gripping device, the finger has a certain degree of softness (following property) when performing a fitting operation for inserting the object to be gripped with the finger into a predetermined position. It has a feature that it can be executed more smoothly. On the other hand, if the fingers are compliant,
When transferring an object to be grasped, there is a problem that the so-called cantilever natural frequency is lowered and the operation controllability of the manipulator is significantly lowered. And
This problem is especially caused when the mass of the object to be grasped is large.
Remarkably appears. As described above, the conventional gripping device has a problem that it is difficult to perform various operations with high accuracy. In addition, the said situation is the same also in the holding device in the manipulator system used on the ground.

[0004]

As described above, the conventional gripping device for a manipulator has a problem that it is difficult to perform various works with high accuracy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manipulator gripping device having a simple structure and capable of realizing highly accurate execution of various operations.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a link mechanism for opening and closing a plurality of fingers to release and grip an object to be grasped, and a manipulator base portion are supported, and a driving force from a driving source is applied to the link mechanism. A finger drive means for transmitting and controlling the link mechanism by operating the link mechanism to open and close the plurality of fingers and a base portion of the link mechanism for supporting and coupling to the manipulator base portion. A gripping device for a manipulator is provided with a coupling means for elastically coupling or rigidly coupling according to a gripping force.

[0007]

According to the above construction, the finger driving means controls the operation of the link mechanism so that it is rigidly connected to the manipulator base portion when rigidity for fitting work or the like is required, and elastic force for transferring work or the like. When it is required to have, the operation is controlled so that the link mechanism is elastically coupled to the manipulator base, and the coupling state is variably set,
The gripping by fingers is set to the optimum state according to the work content. As a result, a plurality of different types of work are executed in the best state, and high-precision work is possible in each work.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a gripping device for a manipulator according to an embodiment of the present invention.
At 0, a grip drive motor 11 is arranged. A ball screw 12 is engaged with a rotary shaft 11a of the motor 11 via a reduction gear mechanism 13 so that a rotational force can be transmitted, and a ball nut 14 is movably attached to the ball screw 12 in the directions of arrows A and B. It is screwed. One end of a first link 15 forming a parallel link mechanism is linked to the ball nut 14, respectively. The first link 15 is provided corresponding to, for example, two or three fingers 16 that constitute the finger mechanism, and the other end is linked to each finger. Further, one end of the second link 17 is coaxially linked to the other end of the first link 15, and this second link 17
The other end of is linked to the mounting portion 18a of the housing 18. One end of the third link 19 is linked to the attachment portion 18a in parallel with the second link 17, and the other end of the third link 19 is linked to the finger 16.

A slide bush 22 is fitted in the first link 15, and a guide shaft 21 is fitted in the slide bush 22. Thus, when the ball nut 14 is driven by the ball screw in the directions of arrows A and B, the first link 15 is moved by the slide bush 22 being guided by the guide shaft 21.

The housing 18 is a manipulator base 1.
It is supported via a coupling member 20 which is elastically deformable with respect to zero. As shown in FIG. 2, the coupling member 20 includes a first coupling portion 20a supported by the housing 18, a second coupling portion 20b supported by the manipulator base portion 10, and the first and second coupling portions 20a. , 20b is formed in combination with an elastic portion 20c interposed in the intermediate portion. Of these, the elastic portion 20c is formed of, for example, an elastic body such as a leaf spring made of stainless steel or synthetic resin as shown in FIG. 3, and a plurality of through holes 20d are formed at predetermined intervals in an intermediate portion thereof. Manufactured to be deformable in the direction of the arrow.

On the other hand, the first and second coupling portions 20a, 20
In b, the recesses 20e and 20f forming the accommodating portion are provided corresponding to each other, and the elastic portions 20c are accommodated in the recesses 20e and 20f. Further, notches 20g and 20h are provided at the tips of the recesses 20e and 20fd of the first and second coupling portions 20a and 20b so as to correspond to each other.
The notches 20g and 20h are spaced apart from each other in a state where the elastic portions 20c are mounted in the recesses 20e and 20f, and realize elastic coupling by the action of the elastic portions 20c.
When c is deformed and abuts, the first and second coupling portions 20
a and 20b are integrally connected and rigidly connected.

In the above structure, when the motor 11 is rotationally driven, the ball screw 12 is rotationally driven via the reduction gear mechanism 13, and the ball nut 1 is driven according to the rotational direction.
4 is moved in the direction of arrow A or B to move the first link 1
5 is activated. Here, when the ball nut 14 is moved in the direction of the arrow B, the fingers move the second and third links 17,
It is opened and closed with respect to the housing 18 via 19 and grips an object to be gripped (not shown). In this gripped state, the urging force in the direction of arrow B is applied to the housing 18 by the action of the first to third links 15, 17, and 19, and the first and second coupling portions 20a of the coupling member 20 are provided. , 2
A compressive force is applied to the elastic portion 20c between 0b. As a result, the coupling member 20 is kept until the biasing force reaches a constant value.
Due to the elastic force of the elastic portion 20c, the notches 20g and 20h of the first and second coupling portions 20a and 20b are separated from each other, and the elastic coupling state is maintained by the action of the elastic portion 20c. As a result, the finger 16 is provided with followability according to the elasticity of the elastic portion 20c of the coupling member 20 suitable for moving work and the like, and is set in an elastic gripping state suitable for transferring work and the like.

When the ball nut 14 is further moved in the same direction to increase its urging force, the connecting member 2
In the case of 0, the first joint portion 20a is moved and biased in the direction of the second joint portion 20b, and the pressure contact force to the elastic portion 20c is increased. Thereby, the elastic portion 20c of the coupling member 20 is deformed, the cutout portions 20g, 20h of the first and second coupling portions 20a, 20b are abutted and rigidly coupled, and the housing 18 is attached to the manipulator base portion 10. Stiffly connected. As a result, the finger 16 is switched from the elastic gripping state to the rigid gripping state suitable for fitting work and the like.

When the gripping of the object to be gripped (not shown) by the finger 16 is released, the motor 11 is reversed. Then, the ball screw 12 is inverted and driven, and the ball nut 14 is moved in the direction of arrow A, so that the first to third links 15, 17, 19 are inverted and the finger 16 is moved.
The gripping of the object to be gripped is released by a motion substantially opposite to the gripping motion.

As described above, the gripping device of the manipulator described above includes the first to third link mechanisms for opening and closing the finger 16.
Housing the links 15, 17, 19 of
This housing 18 is connected to the first to third links 15, 1
The manipulator base 10 is attached to the manipulator base 10 via a coupling member 20 that is selectively elastically or rigidly coupled according to the operating positions of the fingers 7 and 19 (the gripping force of the finger 16). Third link 15, 17, 19
Is operated to close and drive the finger 16, the coupling member 20 is elastically or rigidly coupled in accordance with the first to third links 15, 17, 19 (grasping force of the finger 16) to elastically grasp. Alternatively, it is configured to be switched to rigid grip. According to this, by performing the fitting work and the like by elastic gripping and the transfer work and the like by rigid gripping, it is possible to perform a plurality of work contents of different types with high accuracy, and to operate the manipulator. The handling operability above can be improved.

In the above embodiment, the work content is as follows.
Although the case where the present invention is applied to the fitting work and the transfer work has been described as a representative, the present invention is not limited to this and can be applied to various other works. Also, the ball screw 12 is used to convert the rotational motion of the motor 11 into a linear motion.
The present invention is not limited to this and can be configured. Therefore, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

[0018]

As described above in detail, according to the present invention, it is possible to provide a gripping device for a manipulator, which has a simple structure and is capable of highly accurately executing various works.

[Brief description of drawings]

FIG. 1 is a view showing a gripping device for a manipulator according to an embodiment of the present invention.

FIG. 2 is a diagram showing the connecting member of FIG. 1 taken out.

FIG. 3 is a diagram showing an elastic portion of FIG.

[Explanation of symbols]

10 ... Manipulator base, 11 ... Motor, 12 ... Ball screw, 13 ... Reduction gear mechanism, 14 ... Ball nut, 1
5, 17, 19 ... First to third links, 16 ... Fingers, 1
8 ... Housing, 18a ... Attachment part, 20 ... Coupling member, 2
0a, 20b ... 1st and 2nd connection part, 20c ... Elastic part, 20d ... Through hole, 20e, 20f ... Recessed part, 20g, 2
0h ... Notch.

Claims (1)

[Claims] 1. A link mechanism that opens and closes a plurality of fingers to release and grasp an object to be grasped, and a link mechanism that is supported by a manipulator base and transmits a driving force from a drive source to the link mechanism. Control the
Finger driving means for driving the plurality of fingers to open and close, and a base portion of the link mechanism for supporting and coupling to the manipulator base portion, which is elastically coupled or rigidly coupled depending on a gripping force in a gripped state of the plurality of fingers. And a gripping device for a manipulator.