JPS6052790A - Touch sensor - Google Patents

Abstract

PURPOSE:To detect an object to be touched and detected even if this object is non-conductive or there is a paint, clothes, or the like on the surface of the object, by detecting a flexure of a touch bar, namely, a wire, which is generated when the object is touched, as a strain of a flat spring. CONSTITUTION:When a welding wires 2 touches an object 1 to be welded, a bend is generated in a flat spring 7, which is preliminarily brought into contact with the welding wire 2, by the flexure of the wire 2, and a strain is generated in the flat spring 7. This strain is detected by strain gauges 11 and 12 to detect that the object 1 to be welded and the welding wire 2 are brought into contact with each other. A protective plate 10 shields the flat spring to protect the flat spring 7 from sputter, heat, dust, etc. for welding and consists of metallic or heat-resisting materials. The number of flat springs 7 may be increased. Both strain gauges 11 and 12 are not always necessary, and the strain of the flat spring 7 can be detected only by the strain gauge 11 or 12. Positions to which these strain gauges are stuck may be changed to another positions of the flat spring 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a tactile sensor that detects when a welding wire touches a workpiece.

[Prior art]

A conventional device of this type is shown in FIG. In the figure, 1 is the object to be welded, 2 is the welding wire, 6 is the torch that holds the welding wire 2, 4 is the power source connected to the object to be welded 1 and the welding wire 2, and 5 is the current value supplied from the power source 4. is the resistance that limits the

Next, the operation will be explained. Workpiece 1 and welding wire 2
Since a power source 4 is connected between the two terminals 0 and 0, when the workpiece 1 and the welding wire 2 come into contact, a closed circuit is formed through the resistor 5 and current flows. By detecting this current, it is possible to detect that the welding wire 2 and the workpiece 1 have come into contact.

This conventional device is constructed as described above, so when the object to be welded 1 is conductive, one circuit is formed and current flows, but the object to be welded is a non-conductive material, that is, an insulating material or a paint on the surface. In the case of a conductor coated with , a circuit is not formed and no current flows, so there is a drawback that contact cannot be detected.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional methods as described above, and instead of detecting by electric current, the movement of the welding wire when it touches the workpiece is transmitted to the leaf spring to detect the welding material. It is an object of the present invention to provide a tactile sensor that detects contact between a workpiece and a welding wire by distorting a spring and detecting this with a strain gauge.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 1 is an object to be welded, and 2 is a welding wire.

6 is a torch that holds the wire 2; 6 is a case fitted into the torch; and 7 is four leaf springs, which are held by the cylinder 6 and a ring 9. 1° is a protective support plate, 1
1.12 is a strain gauge. There are a total of eight strain gauges 11 and four strain gauges 11 and four, which constitute a bridge circuit (not shown).

Next, the operation will be explained. Welding wire 2 is welded object 1
When the welding wire 2 is touched, the leaf spring 7 which is in contact with the welding wire 2 is deflected and bent. Distortion occurs in the leaf spring 7. This strain is detected by strain gauges 11 and 12, and it can be seen that the object to be welded 1 and the welding wire 2 have come into contact.

The protection plate 10 prevents spatter, heat, dust, etc. from hitting the plate spring 7 during welding, and is made of metal or a heat-resistant material.

In this embodiment, four leaf springs 7 are used, but the number of leaf springs 7 may be increased. Also, both of the strain gauges 11 and 12 are not necessarily required, and only the strain gauge 11 or the strain gauge 12 can be used.
It is possible to detect the strain in the temporary spring 7 by using only the spring 7. Also, the positions where these strain gauges are attached may be changed to other positions on the leaf spring 7.

Although the tactile sensor of this embodiment has been disclosed as being applied to a welding device using welding wire, it is clear that other applications such as assembly, inspection, and measurement are expected.

〔Effect of the invention〕

As described above, in this invention, the deflection of the tactile bar, that is, the wire when an object is touched, is detected as the distortion of the leaf spring, so even if the object to be touched is non-conductive, It has the effect of being able to detect even if there is paint or clothing on the surface.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional contact detection device for detecting contact, FIG. 2 is a cross-sectional view showing a tactile sensor according to an example of the present invention, and FIG. 3 is the same view taken from arrow A in FIG. FIG. 3 is a front view of an example tactile sensor. 1... object to be welded, 2... welding wire, 7... plate spring. 11.12...Strain gauge. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1

Claims (1)

[Claims] In a tactile sensor that detects that a tactile bar has touched an object to be touched, the tactile bar is protruded from a protective support, and four leaf springs are radially contacted at one end by the tactile bar. A tactile sensor characterized in that the other end is held by the protective support and a strain gauge is attached to each of the leaf springs.