JPS59133982A - Method and device for cleaning electrode tip for spot welding - Google Patents

Abstract

PURPOSE:To remove and clean an adhering contamination in a short time without consuming a tip by generating an arc between the tip for electric resistance spot welding and an electricity conductive plate. CONSTITUTION:An electricity conductive plate 2 whose both surfaces are covered with insulating plates 6, 6a is placed between electric resistance spot welding tips 1, 1a to whose tip parts contamination adheres. The tip 1 is held by a clamp arm 4 formed so as to be wrapped in by a gas ring 5 and an electromagnetic coil. High frequency voltage is applied between the tip 1 and the electricity conductive plate 2 and an arc is generated between both of them. The arc rotates and moves by an electromagnetic coil, and gas which mixes some H2 in Ar is made to flow in through the gas ring 5. An oxide film and contamination adhering to the tip of the tip 1 are removed by a cleaning action of the arc and heat. In this way, the tip is cleaned easily and regenerated without executing a conventional method of cutting, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for cleaning tips of electrical resistance spot welding.

Dirt or deformation of the tip of the spot welding tip directly affects weldability. Particularly when welding plated steel plates or aluminum plates, the tips often get dirty, so the tips must be cut and replaced frequently.

In spot welding work using Rohonoto, this problem of tip replacement was a major problem.

The present invention does not regenerate the dirt on the tip by cutting as in the conventional method, but uses the cathode spot cleaning action of an arc to remove the dirt at high speed without wearing out the tip. That is, an arc is generated using the tip of the tip as a cathode, and the cleaning action of this arc removes the oxide film on the tip of the tip, and the high temperature of the arc cleanses deposited plating and other deposits. Furthermore, changes in the shape of the tip can be corrected by applying strong pressure to a mold that matches the shape of the tip and causing plastic deformation.

Hereinafter, the features of the present invention will be specifically explained according to the drawings.

Insert the current-carrying plate (2) whose both surfaces are covered with insulating plates (6) and (6a) between the tips (1) and (1a) of the welding head (not shown) with the chia 1 open. do. Insulating board (
A part of 6) is cut out in a circular shape, and a heat-resistant ring (3) is inserted there.
is attached, and a slight circular gap is formed between the chip (1) and the current-carrying plate (2).

A heat-resistant ring (3) is attached to the horizontally moved side (6a) as well as the (6) side.

The chip (1) is held in close contact with a clamp arm (4) which is divided into two halves in a semicircular shape and configured to sandwich the chip (1). The clamp arm (4) is equipped with a gas ring (5) which is divided into two parts in a semicircular shape, and an electromagnetic coil (
7) is attached so as to enclose the chip (11).

The clamp arm (4) and the current-carrying plate (2) are connected to the electromagnetic coil (7).
) to an arc power source (not shown).

If an arc is generated between the chip (1) and the current-carrying plate (2) under the above conditions using high frequency or the like, the arc runs around while being rotated by the electromagnetic coil (7). At this time, the current-carrying plate (21b) and the chip (1) are sufficiently cooled with cooling water, and a gas containing argon and some hydrogen is introduced through the gas ring (5).

The oxide film and dirt deposited on the tip of the tip (1) by the running arc column are removed by the cleaning action of the arc and by heat. (Changing the arc power source to alternating current,
It is also a good idea to make the most of the polarity of the arc by changing the polarity from time to time.) After cleaning the tip (1), move the current-carrying plate (2) horizontally and place the heat-resistant ring (3) on the (6a) side.
), and clean by generating an arc between the vc(la) and the current-carrying plate (2) as in 7 above.

In this way, the cheat tubes 10 and (1a) are cleaned. The cleaned tip is strongly pressed into a mold (8) made to have the same shape as the tip. The mold (8) itself may also be vibrated or rotated.

The position where the chips (+1 and (1a)) are arc cleaned and the position where they are shaped with the master die (8) can be moved in parallel on the same plane as the current-carrying plate (2), so stop at each position for an appropriate amount of time. By rotating or moving back and forth, the upper and lower electrode tips of the groove welding device can be automatically cleaned in a short time.

Particularly in welding work using a robot, the objects to be welded can be cleaned during the replacement time, and welding can be performed with high reproducibility.

The above describes the case where the upper and lower electrode tips are fully automatically cleaned. However, when cleaning the upper and lower electrodes individually manually, the above-mentioned current-carrying plate (2) and arm (4) can be combined into one unit. In this case, an extremely small and lightweight porta-pull type cleaning device can be obtained.

In addition, since the cleaning work simply involves generating an arc, workers can perform the work much easier than in the past. Suitable for welding work where the tip must be frequently cleaned.

As described above, according to the present invention, instead of cutting as in the past to remove dirt from the tip tip and adjust the shape,
An arc is generated, the oxide film is removed by the cleaning action of the cathode spot, and the attached plating and dirt are evaporated by heat.
Since the tip shape is maintained by cleaning and applying strong pressure to the mold, not only is there less wear on the tip, but in the case of robot welding work, cleaning can be done each time within the time it takes to attach and detach the object to be welded, improving welding quality. The effects are extremely large, such as being able to stably improve the

[Brief explanation of drawings]

Figure 1 is a perspective view of the device of the present invention. Figure 2 is a sectional view of the arc generating part (11(la) electrode tip, ('2) current carrying plate, (3) heat resistant ring, (4) clamp arm, (5) gas ring,(
6) Insulating plate f71 mm coil, (8) amphoteric type, (9
) Air noku ibrator

Claims (5)

[Claims] (1) Insert a current-carrying plate with a slight gap between it and the tip of the electrode tip, use the tip of the electrode tip as a cathode, generate an arc between the plate and the current-carrying plate, and use the cleaning action of the cathode to clean the tip of the tip. A method for cleaning an electrode tip for spot welding, characterized by: (2) A method for cleaning an electrode tip according to claim 1, characterized in that a magnetic field is formed coaxially with the arc current and the arc column is rotated around the tip of the tip. (3) An electrode tip cleaning device comprising means for inserting a current-carrying plate with a slight gap from the tip of the electrode tip, and means for generating an arc between the electrode tip and the current-carrying plate by using the electrode tip as a cathode. (4) An electromagnetic coil or permanent magnet that forms a magnetic field coaxial with the arc current is attached to either or both of the electrode tip and the current-carrying plate. An electrode tip cleaning device according to claim 3. (5) The electrode tip cleaning device according to claims 3 and 4, further comprising means for shaping the cleaned electrode tip by forcefully pressing it into a mold.