JPS61164790A - Gripper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a gripping device 11tC for a robot, a control type manipulator, etc., and particularly relates to a gripping device with a gripping force detection mechanism.

[Technical background of the invention and its problems] With the recent development of industrial robots, their field of application is expanding from simple tasks such as material handling to advanced assembly tasks. Under these circumstances, the application of various types of sensors is required to enhance the functionality of robots and further expand their application fields. One of these is a gripping force sensor that detects the force with which a workpiece is gripped. This plays an important role as feedback information to the operator, not only for industrial robots, but also for control type manipulators used in fields such as nuclear power, and is particularly useful for handling fragile objects such as snails. This is an essential function in some cases.

Conventionally, strain gauges have been widely used to detect gripping force, but
In order to detect a minute gripping force, an external force 1 can be detected by providing a notch 2 in the finger part l of the gripping device as shown in Figure 1 (2).
A method was adopted in which a strain gauge 3 was attached to the part C to increase the deformation caused by the second strain. However, according to this method, the detected value of the gripping force differs depending on the contact position between the workpiece and the fingers 1, and the contact friction force is small because the workpiece and the fingers are in point or line contact with the finger IFi, so the disadvantage is that the workpiece cannot be gripped with a small force. [Object of the Invention] The present invention aims to solve the above-mentioned conventional drawbacks and provide a gripping device that can grip a workpiece with a small force and detect the gripping force. Overview] In the present invention, the contact portion of the finger portion of the gripping device with the workpiece is made of a material that is easily deformed, and the inside thereof is filled with a sealed liquid. Further, the sealed liquid is guided through a tube 1 to a gripping force detector C which detects pressure changes.

When a workpiece is gripped by a gripping device having such a configuration, the shape of the workpiece C: Therefore, a part of the contact part of the finger part deforms, and the gripping force is transmitted to the gripping force detection device C as a pressure change. The contact area with the workpiece is large, making it possible to grip the workpiece with small force.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. 2.

In Fig. C:, 4 is a finger portion l of the gripping device (; the provided gripping portion is made of a material that is easily deformed such as a synthetic film. The filled liquid 5 is guided through a flexible tube 6 to the gripping force detector 7, which is partitioned in the center by a diaphragm 8, and the left side of the diaphragm 8 is filled with the filled liquid. The right side is in contact with the atmosphere, and a strain gauge 3 is affixed to the surface.In the gripping device full unit with the above configuration, a drive device (not shown) (from the second parallel link mechanism C unit above and below) Finger part up and down C;
When the workpiece is moved and gripped, the gripping part 4 deforms, and the pressure change of the sealed liquid 5 inside deforms the diaphragm 8 through the flexible tube 6v.

The gripping force is detected from the extra gauge 3C attached to the diaphragm 8. Since the gripping force 4 deforms according to the shape of the workpiece, the contact area with the workpiece is large and the workpiece can be gripped with a small force. With (:, it has the effect of being able to detect the gripping force as the average pressure/force of the entire contact surface.

In the embodiment shown in FIG. 2, a combination of a diaphragm 8 and a strain gauge 9 is used as the gripping force detector 7, but instead of these, a semiconductor pressure sensor utilizing a piezoresistive effect may be used.

[Effects of the Invention] I would like to explain this to you.According to the present invention, the shape of the workpiece C; therefore, the structure of the gripping portion that deforms and the pressure of the liquid sealed in the gripping portion (; a method for detecting the gripping force is adopted. Because I am doing
It is possible to grip a workpiece with a small force. 1: It is possible to provide a gripping device that can detect gripping force as the average pressure on the contact surface.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional gripping device. 1...Finger part 2...Notch 3...Strain gauge 4...Gripping part 5...Sealed liquid 6.
...Flexible tube 7...Gripping force detector 8
...Diaphragm agent Patent attorney Noriyuki Chika (
and 1 other person) Figure 1

Claims (1)

[Claims] Equipped with a gripping part made of a material that is filled with sealed liquid and easily deformed, a gripping force detector consisting of a diaphragm and a strain cage, and a flexible tube for transmitting the filled liquid between the gripping part and the gripping force detector. A gripping device characterized by