JPS5819389B2 - How to apply electrode protectant to resistance spot welding machine electrode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of applying an electrode protective agent to an electrode of a resistance spot welding machine to prevent deposited foreign matter from adhering to the electrode.

In recent years, from the perspective of limited resources, even in automobiles, etc.
In order to save fuel, save materials, and increase service life, efforts are being made to reduce the weight of vehicles by making the steel plates used in vehicle bodies as thin as possible.

As mentioned above, if the thickness of the steel plate used for the car body is made thinner, if the coating surface applied to the outside of the steel plate is damaged, the period for the steel plate to rust and develop holes will be shortened accordingly. This will no longer lead to the aforementioned improvement in service life.

For this reason, efforts are being made to improve the adhesion of the paint itself to the steel plate, and to increase the durability of the paint against physical and chemical forces. Galvanized steel sheets and aluminium-plated steel sheets, which are coated with highly corrosion-resistant metals such as steel and aluminum, are increasingly being used in parts of vehicles that are prone to rust.

The zinc and aluminum plating films on the above-mentioned plated steel sheets have low melting points, so when these sheets are welded by regular spot welding, the plating material melts due to resistance heat and the surface of the electrode (copper alloy) is partially welded to the electrode material. It adheres in an alloyed state or, depending on the welding conditions, as an oxide of zinc or aluminum.

As a result, conductivity is impaired, temperature distribution during welding cannot be achieved in an ideal manner, and the nugget shape of the welded part becomes too small, or in some cases, no nugget is formed, resulting in poor welding strength. Reliability is significantly reduced.

In order to solve the above-mentioned problems, multifaceted improvement measures have been taken in the past regarding electrode materials, electrode shapes, welding conditions, etc., but they are still not sufficient.

In addition to the above-mentioned improvement measures, a relatively easy method is to use a liquid or grease-like electrode protectant (hereinafter simply referred to as a protectant) consisting of a component similar to the spatter preventive agent used during arc welding.

) to the electrode, or by applying a protective agent to the entire surface of a rust-proof alloy steel sheet such as a galvanized steel sheet or an aluminium-plated steel sheet, and spot welding with this applied state, the electrode is free from contaminants. Prevents adhesion.

However, it is economically disadvantageous to apply a protective agent to the entire surface of a rust-proofing alloy steel sheet, and it also has drawbacks such as considerable complexity in controlling the amount of application. .

In addition, in the method of applying a protective agent to the electrode, the worker applies an eye-sized amount of the protective agent to the fingertip and applies it to the electrode pressurizing surface, so there is no risk of the worker's fingertip being compressed by the electrode. Furthermore, it has various disadvantages such as difficulty in controlling the amount of protective agent applied, contamination of the worker's fingertips with the protective agent, and complicated application work.

The present invention relates to a method of applying a protective agent to an electrode by solving the above-mentioned conventional drawbacks.When applying a liquid or semi-solid protective agent to an electrode, the present invention is directed to a method of applying a protective agent to an electrode by applying the protective agent to an operator's fingertip. The purpose of the present invention is to provide a method that can easily apply a protective agent to an electrode without causing any trouble to the operator by eliminating dirt on fingertips, danger, excessive application amount, etc. .

Embodiments of the present invention will be described in detail below with reference to the drawings.

1.1', 1'', . . . each have a bag portion 10 approximately in the center thereof, and a predetermined amount of the liquid or semi-solid protective agent G described above is sealed in the bag portion 10. It is a foil bag.

The material of the foil-like bags 1, 1', 1'', etc. may be any metal or synthetic resin such as plastic, as long as it is airtight, and the thickness of the bag portion 10 is t. It is formed into a so-called foil shape with a thickness such that the bag portion 10 is easily broken by the pressing force of the electrode 2 and the lower electrode 3 in a resistance spot welding machine.

Reference numeral 20 indicates an upper electrode arm that supports the upper electrode 2 in a vertical manner, and 30 indicates a lower electrode arm that fixes the lower electrode 3.

In addition, each of the foil-like bags 1, 1', 1''... are provided with cuts of appropriate depth or holes at appropriate intervals in their adjacent portions C, C...... It is constructed so that the desired foil-like bag 1 can be easily separated from the adjacent foil-like bag 1', and the foil-like bags 1, 1', 1/
'... are connected in a series of strips.

When it becomes necessary to apply the protective agent G to the pressurizing surface 200 of the upper electrode 2 and the pressurizing surface 300 of the lower electrode 3 due to an increase in the number of welding points, in the present invention, the operator first applies a series of The foil-like bag 1 located at the leading edge of the foil-like bag group 1゜1/, 1'', etc. Position the bag at the position to be pressed and, for worker safety, hold another foil-like bag, such as 1' or 1'', that does not interfere with the upper electrode 2 and lower electrode 3 with your fingertips, and then press the upper The electrode 2 is pressurized to the lower electrode 3 by a welding machine control device (not shown), that is, it is blank-shot.

As shown in FIG. 4, the pressure applied by this dry punching causes the foil skin 100 of the bag portion 10 of the foil bag 1 to break through the upper and lower electrode pressurizing surfaces 200, 300, and the bag portion 10 is filled. The protective agent G flows out to the outside and is applied in a predetermined amount near the pressure surfaces 200° and 300 of the upper electrode 2 and lower electrode 3.

Next, in this state, or with the upper and lower electrodes 2°3 spaced apart from each other, the foil-like bag 1 involved in the breaking is separated from the foil-like bag 1' adjacent to it at the previously swaged cut. etc., and abandon it as well.

After the protective agent has been applied to the pressure surfaces 200 and 300 of the upper and lower electrodes in this manner, spot welding of galvanized steel plates, etc. is performed as many times as necessary to prevent contaminants from adhering to the pressure surfaces 200 and 300. When the spot welding of 200.
Positioning the foil bag 11 with respect to the pressure surface 20
Apply the protective agent to 0°300.

The number of strokes of the spot welding machine that maintains the effect of the protective agent is approximately determined by the materials to be welded and the performance of the preservative. If you display this when it reaches
It becomes possible to obtain accurate protective agent application timing.

As described above, according to the present invention, since a certain amount of the protective agent is sealed in advance in the foil-like bag, a substantially constant amount of the protective agent is always applied to the electrode, making it possible to control the amount of the protective agent applied. In addition, the worker's fingertips are covered with protective agent because the worker holds any part of the foil bag body other than the bag part involved in breaking and pressurizes the upper and lower electrodes of the resistance spot welding machine during application work. This eliminates the risk of contamination between the upper and lower electrodes, making it safer, easier to work with, more economical, and more accurate than the conventional process of applying protective agent to the electrodes. It has the effect of significantly increasing

In the above description, only the manner in which the foil bags are arranged in a series of strips is described in detail, but the present invention does not necessarily mean that the foil bags are arranged in a series of strips. For example, each foil bag may have 1
Even when separated into individual foil bags, each foil bag must be held tightly around the bag portion where the protective agent is filled to the extent that the operator's fingertips do not interfere with the upper and lower electrodes of the resistance spot welding machine. It is a matter of course that any form can be applied to the present invention as long as there is room for it.

Furthermore, the present invention is not limited to rust-proofing alloy steel sheets as objects to be welded, but can also be applied to general steel sheets by preventing foreign matter from adhering to the electrodes without impairing the above-mentioned effects of the present invention. It is clear that the purpose can be fully achieved,
Furthermore, upon considering the idea of the present invention, it will be extremely easy for those skilled in the art to apply the method of the present invention to the prevention of foreign matter adhesion to the electrodes of various resistance welding machines other than resistance spot welding machines, and the nozzles of arc welding machines, etc. It is understood that

[Brief explanation of drawings]

Figures 1 to 4 are diagrams for explaining one embodiment of the present invention. Figure 1 is an overall view of the case in which each foil bag is arranged in a series of strips, and Figure 2 is a diagram showing an example of the present invention. 1 is a sectional view taken along line XX in FIG. 1. Fig. 3 is an overall view illustrating the case in which foil bags arranged in a strip shape are positioned in a resistance spot welding machine, and Fig. 4 is an overall view illustrating the case where foil bags arranged in a strip shape are positioned in a resistance spot welding machine. It is a sectional view explaining a case where a part is broken. 1.1', 1"...bow foil-shaped bag body, 10: bag part, 1
00: Foil-like skin of bag portion, 2: Upper electrode, 200: Upper electrode pressure surface, 3: Lower electrode, 300: Lower electrode pressure surface, G
: Electrode protective agent, t: Thickness of the foil-like skin of the bag portion, C: Adjacent portion of each foil-like bag body.

Claims (1)

[Claims] 1. A method of applying an electrode protective agent to the upper and lower electrodes to prevent foreign matter that adheres to the upper and lower electrode pressure surfaces of a resistance spot welding machine during welding work to the upper and lower electrodes. The bag portion of the foil-like bag with the agent sealed therein is placed in a position where it should be pinched by the upper and lower electrodes by sandwiching the remaining portion of the foil-like bag other than the bag portion, and then the upper A method for applying an electrode protective agent to a resistance spot welding machine electrode, comprising: breaking the skin of the bag portion using a lower electrode pressing force, and applying the electrode protective agent inside the bag portion to the pressurizing surfaces of the upper and lower electrodes. .