JPH08174229A - Pressure device for resistance welding - Google Patents

Abstract

PURPOSE: To prevent breakage of a conducting body part due to heat and spattering at welding by interposition electric conductive fluid as lubricant on the sliding face between a pressure cylinder and pressure rod and supplying electricity to a moving electrode from a pressure cylinder through a pressing rod. CONSTITUTION: The sliding boundary face between a cylinder cover part and pressure rod 12 is provided with an electric conductive fluid 14 of low melting point metal, etc., as a lubricant in annular shape, both sides are sealed by a seal member 15. By this method, the pressure cylinder 11 and pressure rod 12 are electrically connected through the electric conductive fluid 14. Concerning an electric conductive fluid, e.g. mercury, gallium, rubidium and these alloy are used. Among them, mercury has low melting point and is used for cold climate almost without restriction. By this method, breakage of the electric conducting body part due to heat and spattering at welding is not generated, power supply is done without occupying narrow space around electrode by the electric conducting body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a power feeding mechanism for a movable electrode of a pressure welding device for resistance welding.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, resistance welding pressurization for supplying power and pressurizing a welding portion by a movable electrode 43 attached to the tip of a pressure rod 42 slidable in a pressure cylinder 41. The device is known. Movable electrode 43 and fixed electrode 4
The workpieces 50 and 51 are pressed against each other by 4 and welded.
Power is supplied to the fixed electrode 44 from the welding power source 40 to the rigid conductor 45.
Power is supplied to the movable electrode 43 from the welding power source 40 by the rigid conductor 46, the flexible conductor 47, and the rigid conductor 48.
And 49. The flexible conductor 47 is necessary to allow the stroke movement of the movable electrode.

Since the flexible conductor 47 is exposed to heat and spatter generated during welding, it is apt to be damaged by repeated operation, and there is a problem that the reliability of the entire welding apparatus is lowered. Further, since the flexible conductor 47 that occupies a relatively large space is near the movable electrode 43, when the movable electrodes 43 are arranged in a narrow space, the existence of the flexible conductor 47 itself hinders the arrangement of the electrode 43. there were.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems of the prior art, the present invention occupies a narrow space near the electrode with a conductor without causing damage to the conductor portion due to heat or spatter during welding. An object of the present invention is to provide a pressurizing device for resistance welding, which has an improved power supply mechanism to the movable electrode so that power can be supplied without supplying power.

[0005]

In order to achieve the above object, the resistance welding pressurizing device of the present invention is a welding part by means of a movable electrode attached to the tip of a pressurizing rod that slidably moves in the pressurizing cylinder. In a pressure device for resistance welding that performs power supply and pressure application, a conductive fluid is interposed as a lubricant at the sliding interface between the pressure cylinder and the pressure rod, and the pressure cylinder moves to the movable electrode via the pressure rod. The feature is that power is supplied.

[0006]

According to the present invention, a conductive fluid is interposed as a lubricant at the sliding interface between the pressure cylinder and the pressure rod, electricity is supplied through the conductive fluid, and the pressure cylinder moves through the pressure rod through the pressure rod. Since the power is supplied to the electrodes, the flexible conductor exposed to the outside of the periphery of the movable electrode is not damaged and the flexible conductor does not hinder the arrangement of the plurality of electrodes in a narrow space as in the conventional case.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0008]

1 to 3 show a pressure welding device for resistance welding according to the present invention. 1 is a perspective view showing a main part of the pressurizing device, FIG. 2 is a horizontal sectional view taken along line II-II in FIG. 1, and FIG. 3 is line III in FIG.
It is a vertical sectional view in -III. The resistance welding pressurizing device of the present invention shown in the drawings is a pressurizing cylinder 1 whose one end is fixed to a mounting bracket 10 for mounting on a support frame (not shown).
A pressure rod 12 is slidably housed in the unit 1.
The pressure rod 12 penetrating through the central portion of the cover portion 11A that seals the other end of the pressure cylinder 11 and protruding to the outside.
The movable electrode 13 is attached to the tip of the.

Cylinder cover portion 11A and pressure rod 1
An electrically conductive fluid 14 such as a low melting point metal such as mercury is provided in an annular shape as a lubricant for allowing the sliding movement between the two and the sealing interface between the two sides. There is. Thereby, the pressure cylinder 11 and the pressure rod 12
Are electrically connected to each other via the conductive fluid 14. This continuity is maintained even if the pressure rod 12 slides in the direction of arrow B in FIG.

A normal insulating lubricant is interposed at the sliding interface between the pressure cylinder 11 and the pressure rod 12 other than the above. In the above structure, when a welding current is applied to the cover portion 11A of the pressurizing cylinder or the pressurizing cylinder 11 through an appropriate terminal or the like, the electric current passes through the conductive fluid 14 at the sliding interface and the pressurizing rod 12. It is supplied to the movable electrode 13.

The conductive fluid of the present invention includes mercury (melting point −38.842 ° C., resistivity 98.4 × 10 ⁻⁶ Ωcm),
Gallium (melting point 29.78 ° C, resistivity 17.4 × 10 ^-6
Ωcm), rubidium (melting point 38.89 ° C, resistivity 1
2.5 × 10 ⁻⁶ Ωcm) and alloys of these can be used. Among them, especially mercury has a low melting point, so that it can be used with almost no limitation even in a cold climate.

However, the conductive fluid used in the present invention is not limited to the above metals or alloys, and can exhibit the necessary lubricity and conductivity under the conditions (temperature, etc.) in which the pressurizing device operates. Any substance will do.

[0013]

As described above, according to the present invention, power can be supplied without causing damage to the conductor portion due to heat or spatter during welding and occupying a narrow space near the electrode with the conductor.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a pressure welding device for resistance welding according to the present invention.

FIG. 2 is a horizontal sectional view taken along line II-II in FIG.

FIG. 3 is a vertical cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a front view showing a main part of a conventional resistance welding pressurizing device.

[Explanation of symbols]

10 ... Bracket for mounting to a support stand (not shown) 11 ... Pressurizing cylinder 11A ... Cover part of the pressurizing cylinder 11 12 ... Pressurizing rod 13 ... Movable electrode 14 ... Conductive fluid provided annularly (like mercury) 15 ... Sealing member 40 ... Welding power source 41 ... Pressurizing cylinder 42 ... Pressurizing rod 43 ... Movable electrode 44 ... Fixed electrode 45 ... Rigid conductor 46 ... Rigid conductor 47 ... Flexible conductor 48 ... Rigid conductor 49 ... Rigid conductor 50 ... Work 51 ... Work

Claims (3)

[Claims] 1. A resistance welding pressurizing device for supplying power and pressurizing a welding part by a movable electrode attached to the tip of a pressurizing rod that slidably moves inside the pressurizing cylinder. A pressure welding device for resistance welding, characterized in that a conductive fluid is interposed as a lubricant at the sliding interface so that power is supplied from a pressure cylinder to a movable electrode via a pressure rod. 2. The pressure welding device for resistance welding according to claim 1, wherein the conductive fluid is a low melting point metal. 3. The pressure welding device for resistance welding according to claim 2, wherein the low melting point metal is mercury, gallium, rubidium, or an alloy thereof.