JPS5856075Y2 - Conductive connection device in resistance welding machine - Google Patents

Description

[Detailed description of the invention] This invention relates to a conductive connection device for connecting a welding power source to a movable electrode of a resistance welding machine via a conductive member.
More specifically, it relates to a conductive connection device useful for effectively protecting a long secondary conductive plate and preventing loss of welding current in a welding machine with a large electrode stroke and a long secondary circuit arm. It is.

As is well known, in the case of welding machines with long electrode strokes and long arms, especially when a heavy and long single flammable conductive plate or conductor is used as a secondary circuit connecting the welding transformer and the movable electrode. If bending or bending motion is applied to the conductive member due to the repeated linear motion of the movable electrode, fatigue and wire breakage will accelerate, causing current loss and shortening the life of the conductive member.

Therefore, as a countermeasure to this problem, conventionally, instead of using a single flexible copper plate or conductive wire, several conductive links were used.

The bars Bl and B2 are connected via pivots PI and P2 and P3, respectively, and the joints are slid and rotated in one plane to form the axes of the welding transformer T and fixed electrode 16 in the main body 0. The movable electrodes 1 on the line are connected.

In this case, the contacts of the joint are slid and rotated by the movement of the movable electrode that is moved up and down by the pressure cylinder 2, and welding current is supplied to the movable electrode through the sliding surface of the joint.

However, in the case of this type of link-bar-slide power feeding system, since the power is fed by sliding, the slide surface must be crimped with a uniform average force at all times, making the structure complex and requiring additional manufacturing man-hours and costs. .

In addition, the sliding surface often gets dirty and heat generation increases, which has the disadvantage of increasing current loss and adversely affecting welding results.

This invention is intended to solve the above-mentioned drawbacks, and involves connecting a plurality of U-shaped flexible conductive plates in relays and stages, so that the relay point of each conductive plate is connected in relation to the vertical stroke movement of the movable electrode. The connection structure is designed so that the movable electrodes can move in conjunction with each other while being supported and guided, and is designed to prevent current loss and improve the durability of the secondary conductive plate.

This invention will be explained below based on the "embodiments" shown in the drawings.

FIG. 2 shows the main parts of the conductive connection device according to this invention.A movable electrode 1 has an electrode arm 4 attached to the tip of a rod 3 of a pressure cylinder 2 fixed to the upper arm of a welding machine 0. An electrode tip 6 is attached to this electrode arm via an electrode holder 5.

A first U-shaped flexible conductive plate 7 is provided at the rear end of the electrode holder 5.
The end of a is fixedly tightened with a bolt 8.

A connecting piece 9a is provided at the other end of the first conductive plate 7a.
The end of the second U-shaped flexible conductive plate 7b is fixed through the third U-shaped flexible conductive plate 7b connected to the output terminal 10 of the welding transformer T. The ends of the flexible conductive plate 7c are connected via a connecting piece 9b.

Each connecting piece 9a, 9b is provided with a side of each conductive plate 7a, 7b facing each other so that each connecting part engages with and interlocks with the vertical stroke movement of the movable electrode 1 as a connecting metal fitting. A U-shaped bracket 11 corresponding to the stroke of the conductive plate and a T-shaped metal fitting 13 that engages with the projecting piece 12 of the bracket 11 on the opposite side are installed insulated from each other.

Guide rods 14 and 15 corresponding to guide devices supported and guided by the upper arms are connected to each of the connecting pieces 9a and 9b, respectively.

The movable electrode in the illustrated state is currently being lowered by the pressure cylinder.

Therefore, although the T-shaped metal fitting 13 of the connecting piece 9a and the other U-shaped receiver are at the midpoint of the fitting 11, when the movable electrode 1 is still lowered by the pressurizing cylinder 2, the first conductive plate 7a is lowered, and the aforementioned metal fitting 13, the above-mentioned receiver is caught on the projecting piece 12 of the fixture 11 and lowers the second conductive plate 7b connected to the next connecting piece 9b, and in the same way, the next metal fixture 13' is engaged with the next fixture 11'. At the same time, the third conductive plate 7C is pushed down and the entire conductive plates are lowered step by step by a predetermined stroke until the movable electrode comes into contact with the workpiece W of the fixed electrode 16.

In this case, each connecting piece 9a, 9b is connected to the guide rod 1.
4.15 allows the movable electrode 1 to move smoothly while being guided and supported during the movement period.

In this way, with the workpiece pressed between the two electrodes,
When the current is applied from the welding transformer, the current flows to the third point above.
Electric power flows from the conductive plate 7C through the second conductive plate 7b to the first conductive plate 7a, and is supplied to the electrode holder 5 and electrode tip 6 through the electrode arm 4 to perform welding.

After welding, the first conductive plate is moved by the upward movement of the movable electrode.

Second. The entire conductive plates are raised stepwise in the order of the third conductive plate.

As explained above, this invention allows the movable electrode to move up and down on the axis of the fixed electrode when the welding power source is connected via a conductive member to the movable electrode of a welding machine that has a long stroke and a long arm. A movable electrode and a welding transformer electrically connected between these electrodes are connected in series by a plurality of U-shaped flexible conductive plates whose ends are connected to each other, and each of the conductive plates is The connecting portion is provided with a connecting fitting so that adjacent connecting portions engage and interlock with each other in relation to the vertical movement of the movable electrode, and the connecting portion is provided with a metal fitting during the movement of the movable electrode. Provided is a conductive connection device characterized by being provided with a guide device for supporting and guiding.

Therefore, according to this invention, even when configuring a secondary circuit with a long electrode stroke, the movement of the movable electrode can be easily accommodated, and fatigue and disconnection of the conductive member can be eliminated as in the conventional method. First, it does not have an expensive and complicated structure like the slide feeding system, and it also has many excellent effects such as eliminating current loss and increasing the life of the conductive member.

[Brief explanation of drawings]

FIG. 1 is an overall side view of a spot welding machine showing a conventional conductive connection device using a conductive ring bar. FIG. 2 is a side view showing the main parts of a conductive connection device using a U-shaped flexible conductive plate according to an embodiment of the invention. 1...Movable electrode, 7a, 7b, 7C...U
Letter-shaped flexible conductive plates, 9a, 9b...connection pieces, 11.1
3... Connecting fittings, 14.15... Guide device.

Claims (1)

[Scope of utility model registration request] A movable electrode that moves up and down on the axis of a fixed electrode and a welding transformer that is electrically connected between these electrodes are connected in series by a U-shaped combustible conductive plate whose ends are connected to each other. Each connecting portion of the conductive plate is provided with a connecting fitting so that adjacent connecting portions engage and interlock with each other in relation to the vertical movement of the movable electrode, and a connecting fitting is provided in each connecting portion of the conductive plate so that the adjacent connecting portions engage and interlock with each other in relation to the vertical movement of the movable electrode. A conductive connection device for a resistance welding machine, comprising a guide device for supporting and guiding the connection portion therein.