JPH0655279A - Spot welding equipment - Google Patents

Abstract

PURPOSE:To provide the spot welding equipment where stable work is performed in a short time and spatters are no scattered in the spot welding equipment which pressurizes materials to be welded from the upper and lower sides by a couple of upper and lower electrodes to perform welding. CONSTITUTION:The upper electrode 14 is provided projectingly below from an electrode holder 12, and electrode cap 18 consisting of a cylindrical insulator to cover the upper electrode 14 is fitted freely movably vertically for the electrode holder 12 and when it is in an unpressed state for the materials 30 and 32 to be welded, the electrode cap 18 is energized below by a spring 22 so that the lower end of the electrode cap 18 is protruded below from the lower end of the upper electrode 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding device.

[0002]

2. Description of the Related Art A spot welding apparatus performs welding by sandwiching a material to be welded between a pair of upper and lower electrodes.

The welding procedure is as follows. First, the material to be welded is pressed by a pair of upper and lower electrodes (hereinafter referred to as initial pressing).
Then, the material to be welded is fixed between the two electrodes, and then further pressure is applied to bring the upper and lower electrodes into complete contact with the material to be welded. Then, welding is performed by applying a welding current to the pair of upper and lower electrodes for a predetermined time.

However, the spot welding apparatus having the above structure has the following problems.

The operation for initial pressurization took time.

There is a problem that spatter may be scattered around during welding due to the change of the tip of the electrode with time, and the material to be welded may stick to the electrode.

In order to prevent these two problems, it is necessary to set delicate conditions for the initial pressure and the like, and at the same time,
In some cases, I had to change the settings each time.

Therefore, in view of the above problems, the present invention provides a spot welding apparatus which can perform stable work in a short time and in which spatter is not scattered.

[0009]

The spot welding apparatus of the present invention is a spot welding apparatus in which a material to be welded is pressed from above and below by a pair of upper and lower electrodes to perform spot welding, in which an upper electrode is projected downward from an electrode holder. When the electrode cap made of a cylindrical insulator covering the upper electrode is vertically movably attached to the electrode holder and is not pressed against the material to be welded, the lower end of the electrode cap is the upper electrode. The electrode cap is biased downward by an elastic body so as to project downward from the lower end.

[0010]

[Operation] When welding the material to be welded using the spot welding apparatus having the above-mentioned configuration, first, the material to be welded is sandwiched between the lower electrode and the electrode cap, and the material to be welded is fixed. In this case, since the electrode cap is biased downward by the elastic body, the initial pressure can be easily applied. Then, with this fixed state, move the upper electrode downward,
After completely adhering to the material to be welded, welding current is applied for a predetermined time to perform welding.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 10 is a spot welding apparatus, reference numeral 12 is an electrode holder, and reference numeral 14 is an electrode holder 1.
2 is an upper electrode provided on the lower surface of 2. The lower end of the upper electrode 14 has a truncated cone shape (CF type in JIS standard).

Reference numeral 16 is an outer peripheral cap provided on the lower surface of the electrode holder 12 so as to cover the upper portion of the upper electrode 14. The upper portion 16 a of the outer peripheral cap 16 is fixed to the electrode holder 12. Also, the outer peripheral cap 1
A cylindrical outer wall 16b is vertically provided from an upper portion 16a of the cylindrical member 6. Its height is approximately 3/4 the size of the upper electrode 14. Further, a flange portion 16c is provided inward from the lowermost end of the outer wall 16b.

Reference numeral 18 denotes a cylindrical electrode cap, on the outer periphery of which a groove 20 is provided in the circumferential direction. The electrode cap 18 is made of, for example, an insulator such as synthetic resin. The electrode cap 18 is the outer peripheral cap 16
It is inserted between the outer wall 16b of the and the upper electrode 14. The flange portion 16c of the outer peripheral cap 16 is fitted in the groove 20 of the electrode cap 18, and the electrode cap 18 can move in the vertical direction by the dimension of the groove portion 20 in the vertical direction.

Reference numeral 22 designates an upper portion 16 of the outer peripheral cap 16.
It is a coil-shaped spring provided between a and the upper end of the electrode cap 18. The spring 22 biases the electrode cap 18 downward.

Reference numeral 24 is a lower electrode disposed below the upper electrode 14.

A case where welding is performed using the spot welding apparatus 10 having the above structure will be described.

As shown in FIG. 1, two materials to be welded 30 and 32 are stacked on the lower electrode 24, and the electrode holder 12 is
Is moved downward and the lower end of the electrode cap 18 and the lower electrode 24 are initially pressed to fix the two materials 30 and 32 to be welded. This makes it possible to omit the conventional initial pressing time.

As shown in FIG. 2, when the electrode holder 12 is moved further downward from the initial pressure state, the upper electrode 14 moves downward against the bias of the spring 22.
Then, the upper electrode 14 is sufficiently adhered to the material 30 to be welded,
The two materials to be welded 30 and 32 are sandwiched between the upper and lower electrodes 14 and 24. After that, welding current is applied between the electrodes 14 and 24 for a predetermined time to perform welding. During this welding operation, the upper electrode 14 is completely covered with the electrode cap 18, so that scattering of spatter can be prevented.

As shown in FIG. 3, when welding is completed, the electrode holder 12 and the upper electrode 14 are raised. In the first stage of rising, the material 30 to be welded is held by the electrode cap 18 biased downward by the spring 22, so that only the upper electrode 14 is lifted and the material 30 to be welded is raised.
Does not rise when it sticks to the upper electrode 14.

[0021]

According to the spot welding apparatus of the present invention, the initial pressing time during welding can be omitted.

Further, since the upper electrode is covered with the electrode cap, spatter scattering can be prevented during welding.

Further, since the electrode cap is biased downward by the elastic body, the upper electrode and the material to be welded can be easily separated.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state in which two materials to be welded are sandwiched by a lower electrode and an electrode cap in a spot welding apparatus showing an embodiment of the present invention.

FIG. 2 is likewise a vertical sectional view of a spot welding apparatus during welding.

FIG. 3 is likewise a vertical cross-sectional view of the spot welding apparatus after welding is completed.

FIG. 4 is a perspective view of an electrode cap.

[Explanation of symbols]

 10 ... Spot welding device 12 ... Electrode holder 14 ... Upper electrode 16 ... Outer peripheral cap 16a ... Upper part of outer peripheral cap 16b ... Outer wall of outer peripheral cap 16c ... Flange 18 ... Electrode cap 20 ... Groove 22 ... Spring 24 ... Lower electrode

Claims (1)

[Claims] 1. A spot welding apparatus for pressing a material to be welded from above and below with a pair of upper and lower electrodes to weld the material to be welded, the upper electrode protruding downward from an electrode holder, and comprising a cylindrical insulator covering the upper electrode. The electrode cap is attached to the electrode holder so as to be movable up and down, and when the electrode cap is not pressed against the material to be welded, the lower end of the electrode cap is protruded downward from the lower end of the upper electrode by the elastic body. Spot welding device characterized by urging the cap downward.