JPH01264785A - Robot arm - Google Patents

Abstract

PURPOSE:To make an arm itself lightweight and drive a work supporting plate to the preset position with no change applied on the facing direction by providing elastic shrinkage bodies to drive a parallel link mechanism. CONSTITUTION:When a pressurized fluid is fed to elastic shrinkage bodies 32 and 34, the elastic shrinkage bodies 32 and 34 are expansion-deformed, a shrinkage force is generated in the axial direction. When the elastic shrinkage body 32 connected to a fixed plate 14 at one end is shrunk, a link member 18 related to the fixed plate 14 is rotated centering the junction point of these members. When the pressurized fluid is fed to the other elastic shrinkage body 34 fitted to a link member 26 related to a work supporting plate 28 at one end, the ling member 26 is rotated centering a junction point with a connecting plate 22. When these link members 18 and 26 of a parallel link mechanism are to be returned to the initial positions, the pressurized fluid is discharged from the related elastic shrinkage bodies 32 and 34.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a robot arm using a parallel link mechanism in the arm portion.

(Prior art and its section N) Parallel link mechanisms can always move the link opposite to a fixed link parallel to the fixed link, and are lightweight themselves, so they are useful for table lamps, etc. It is used for.

Normally, when changing the position of a lamp on such a stand, a portion of the link to which the lamp is attached is grasped and moved until the lamp assumes the desired position.

For this reason, there is a problem in that its application is limited to a range in which a user can directly displace the parallel link mechanism. To deal with this problem, some devices are equipped with a structure that uses an electric motor as an actuator to mechanically displace the device, but when using an electric motor, a deceleration means is required, so the device itself Another problem arises in that the weight increases and the lightweight advantage of the parallel link mechanism is lost.

The present invention was made in view of these problems.
The object is to provide a robot arm that uses parallel links without sacrificing their advantages.

(Means for Achieving the Object) In order to achieve this object, the robot arm of the present invention includes a fixed plate fixed to the base, and one end of each fixed plate rotatably supported and parallel to each other. a pair of link members spaced apart from each other; and a connecting plate rotatably supporting the other ends of these link members and rotatably supporting one end of each of the other set of link members spaced apart in parallel. , a work support plate that rotatably supports the other end of another link member, and a workpiece support plate that is arranged to intersect with the link member, one end of which is connected to the middle of one of the link members, and the other end of which is connected to the fixed plate and the connecting plate. It comprises at least a connected elastic contracting body that expands and deforms in diameter and contracts in the axial direction by supply of pressurized fluid.

(Function) When pressurized fluid is supplied to the elastic contractile body, the elastic contractile body expands and deforms in diameter and generates a contractile force in the axial direction. By the way, when an elastic contractile body whose one end is connected to, for example, the fixing plate contracts, the link member related to the fixing plate rotates around the connection point of these members.

Further, by supplying pressurized fluid to the other elastic contractile body, one end of which is attached to the link member associated with the work support plate, the link member is rotated about the connection point with the connection plate. I can do it.

Then, when it is desired to return these link members to their initial positions, pressurized fluid may be discharged from the associated elastic contracting bodies. Preferably, the return of these link members to their initial positions is made more reliable. Therefore, an elastic member is provided that generates an elastic force opposite to the contraction force of the elastic contraction body.

(Example) The apparatus of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, the robot arm of the present invention, designated by the reference numeral 10, has a fixing plate 14 fixed to a base L2 using a conventionally known suitable fixing means.

A pair of link members 18 are rotatably supported by respective connecting pins 16 which are attached to the ends of a fixed plate 14 spaced apart from each other from the base 12.

The link members 18 extend parallel to each other, and their other ends are rotatably attached to connecting pins 20 which are also mounted on a connecting plate 22 at a distance from each other.

This connection plate 22 is provided with another connection pin 24 spaced apart from the connection pin 20. On the other hand, the connection pin 24
rotatably supports one end of a pair of other link members 26 spaced parallel to each other.

These other link members 2 extending parallel to each other
6, the other end of which is attached to a workpiece support plate 28 to which, for example, a light, a robot hand, etc. is fixed.
Rotatably supported.

Next, two sets of link members 1 constituting a parallel link mechanism
One end of each of the elastic contracting bodies 32 and 34 is connected to the intermediate portion of one of the links of each set of link members 8 and 26, respectively. Specifically, as clearly shown in FIG. 1(b), a mount attached to the intermediate portion of one of the associated link members rotatably supports the bins 36 and 38. The other end of the elastic contractile body 32 is rotatably supported by a pin 40 mounted on a fixed plate 14 located closer to the connecting plate than the line connecting the connecting pins 16. This makes the movement of the link member stable.

Further, the other end of the elastic contracting body 34 is also rotatably supported by the protruding end portion of the connecting pin 24, which is rotatably supported at one end of the link member 26.

The elastic contractile body used in this embodiment is of the so-called air bag type, and as shown in FIG.
A tubular body 50 made of rubber or a rubber-like elastic material is formed into a WAill reinforced structure 52 made of, for example, a twisted or untwisted bundle of aromatic polyamide fibers (Kevlar: trade name), filaments such as ultrafine metal wires, etc. The openings at both ends are sealed together with a closing member 54 and caulked with a caulking cap 54 to prevent them from falling out.

Here, the braided reinforcing structure 52 has a braided structure such that the braiding angle θ reaches a so-called rest angle (54°44') when the tubular body is at its maximum expanded diameter when pressurized fluid is applied to the tubular body. are doing. Therefore, supplying pressurized fluid into the internal cavity of at least one of the closure members through a connecting hole formed in the closure member increases the angular expansion of the braided reinforcement structure, i.e., the expansion diameter of the tubular body due to pantograph movement; A resulting axial contraction is produced.

Therefore, when a conduit (not shown) including a three-way valve connected to a pressure source such as an air compressor is connected to the elastic contracting body 32 and pressurized fluid is supplied, the elastic contracting body 32 will move in the axial direction. As it contracts, the arm portion including the link member 18 rotates around the connecting pin in the direction indicated by arrow A in the figure.

This also applies to the arm portion that includes the link member 26.

On the other hand, when the pressurized fluid applied to the elastic contracting body 32 is discharged from inside, the elastic contracting body is allowed to expand in the axial direction, and the arm portion returns to its initial position. .

In this embodiment, in order to make the return to the initial position more reliable, as shown in FIG. An elastic member such as a spiral spring 42 is attached to the connecting pin 16. The spiral spring 42 is not limited to this, as long as it generates an elastic force that opposes the movement of the link member 18 rotating in the direction of arrow B as the elastic contractile body 32 contracts. Similarly, the mounting positions and mounting directions of the elastic contracting body and the elastic member are not limited to these embodiments, and various changes can be made within the scope of the claims.

(Effects) As detailed above, according to the robot arm of the present invention,
Since the parallel link mechanism is itself lightweight, and the parallel link mechanism is driven by the elastic contracting body, the weight of the arm itself can be minimized to make it lightweight. Moreover, by supplying and discharging pressurized fluid to and from the elastic contractile body, the workpiece support plate can be driven to a predetermined position without changing the direction in which it is oriented.

[Brief explanation of the drawing]

FIG. 1(a) is a front view showing the robot arm of the present invention, FIG. 1(b) is a plan view of the device shown in FIG. 1(a), and FIG. 1(b) is a front view showing the robot arm of the present invention. FIG. 2 is an explanatory diagram showing a partially enlarged view of the apparatus shown in FIG. 10- Robot arm 12- Fixed part 14- Fixed play) 16, 20.24.30 Series connection bin 18.2
6--link member 22 series connection plate 28- work support member 32.34-elastic contraction body 36.38.40
-Mounting with pin 42-Spiral spring patent applicant Brideston Co., Ltd. (bJ (C) Procedures Amendment (Method) August 2, 1985 Commissioner of the Japan Patent Office Yoshi 1) Moon Yi 1
, Indication of the case Patent Application No. 92654 of 1988 2, Name of the invention Robot arm 3, Person making the amendment Relationship to the case Patent applicant Brideston Co., Ltd. 4, Agent 6, Subject of amendment 1, On page 9, line 10 of the specification, “Figure 1(b) is” replaced with “
Figure 1 (C) is corrected to ``.

Claims (1)

[Claims] 1. A fixed plate fixed to the base, a set of link members each having one end rotatably supported by the fixed plate and spaced parallel to each other, and the other end of these link members rotatably supported. Also, a connection plate rotatably supports one end of each of another pair of link members spaced apart in parallel, a work support plate rotatably supports the other end of the other link member, and a link member. arranged crosswise, one end connected to the middle of one of the link members, and the other end connected to the fixed plate and the connecting plate;
A robot arm comprising at least an elastic contractile body that expands in diameter and contracts in an axial direction when pressurized fluid is supplied.