JPH0250832B2 - - Google Patents

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a resistance welding device.

[Background technology]

Generally, in this type of resistance welding equipment, welding is performed in the atmosphere, but the joints of the objects to be welded are oxidized, making the formation of alloy layers and diffusion layers unstable, and There was a problem that the strength of the parts was weak and unstable. In addition, in order to prevent changes in welding conditions due to rise in electrode temperature when welding is performed continuously, it is necessary to add a cooling device to the electrode, resulting in a problem that the electrode structure becomes complicated. Figure 1 shows the conventional electrode structure, where 1 is a fixed electrode, 2a is a movable electrode, 1
Reference numeral 1 designates a cooling device that allows cooling water to flow in the direction of the arrow, 12 a cooling water inlet, and 13 a cooling water outlet.

On the other hand, a method of resistance welding by dripping water onto the welded area was also announced (Japanese Unexamined Patent Publication No. 58-80220,
However, there was a problem that instability remained due to variations in the amount and angle of water dripping.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to prevent oxidation of the joint part to strengthen the joint strength, and to stabilize welding conditions by making the welding conditions constant. It is an object of the present invention to provide a resistance welding device that can reduce variations in bonding strength, and has a simple electrode structure.

[Disclosure of the invention]

(Embodiment) Fig. 2 shows an embodiment of the present invention, in which 1 is a fixed electrode, 2 is a movable electrode, and both electrodes 1 and 2 are arranged so that their end faces face each other at a predetermined interval _l0 . A workpiece X to be welded is inserted between both electrodes 1 and 2. Reference numeral 3 denotes a pressurizing device, which urges the movable electrode 2 toward the fixed electrode 1 (in the direction of arrow A) so as to clamp the object to be welded X between the end surfaces of both electrodes 1 and 2. 4 is a power supply device that applies an appropriate voltage between both electrodes 1 and 2, and includes a transformer TR that steps down the commercial power AC;
It is formed by a power switch SW. 5 is a liquid tank filled with a substantially insulating liquid 5a such as pure water, water, Freon, etc.; 6 is a liquid tank in which the liquid 5a is circulated by a circulation pump 7 and cooled by a cooling device 8 to maintain the temperature of the liquid; It is a liquid temperature control device that maintains a constant temperature, and the welding part (opposing part) of the fixed electrode 1 and the movable electrode 2 is placed in a liquid tank 5, and the workpiece X is resistance welded in the liquid 5a. ing. Note that the cooling device 7 may be controlled by providing a temperature sensor that detects the temperature of the liquid 5a in the liquid tank 5. Further, in the embodiment, a level adjustment outlet 9 is provided to keep the liquid level constant.

According to the present invention, the welding parts of the fixed electrode 1 and the movable electrode 2 are placed in the liquid tank 5, and the workpiece X is resistance welded in the liquid 5a without coming into contact with the atmosphere (particularly oxygen). Since oxidation of the bonded portion is prevented, the alloy layer and the diffusion layer are stably formed, the bonding strength is increased, and variations in bonding strength are reduced. Furthermore, as shown in FIG. 3, in the case of joining the contact 14 and the contact spring 15 made of a copper alloy, a fillet Y is formed at the joint of the workpiece X without using a brazing material, and the arc resistance is improved. This has the additional effect of improving performance. Furthermore, since the workpiece X and the welded parts of both electrodes 1 and 2 are covered with the liquid 5a, and the temperature of the liquid is kept constant by the liquid temperature control device, a good cooling effect can always be obtained. At the same time, the welding conditions are made constant, so welding can be performed stably, and variations in joint strength can be reduced. Furthermore, unlike the conventional example shown in FIG. 1, it is not necessary to provide the cooling device 11 to the electrode 2a, so the structure of the electrodes 1 and 2 is simplified.

〔Effect of the invention〕

As described above, the present invention includes a fixed electrode and a movable electrode arranged so that their end faces face each other, and a movable electrode fixed so that the workpiece to be welded inserted between the two electrodes is pinched between the end faces of both electrodes. In a resistance welding device consisting of a pressure device that energizes the electrode side and a power supply device that applies an appropriate voltage between both electrodes, there is a liquid tank filled with a substantially insulating liquid, and a liquid tank that circulates the liquid. A liquid temperature control device that maintains the liquid temperature constant by cooling is provided, and the welding parts of the fixed electrode and the movable electrode are placed in the liquid in the liquid tank, so that the object to be welded is resistance welded in the liquid. Since the objects to be welded are resistance welded without coming into contact with the atmosphere (particularly oxygen), oxidation of the joint is prevented and the joint strength is strengthened. Since the welding area is covered with liquid and the liquid temperature is kept constant by a liquid temperature control device, a good cooling effect is always obtained, welding conditions are kept constant, and welding is performed stably. This has the effect of reducing variations in bonding strength, and furthermore, simplifies the structure of both electrodes.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a conventional example, FIG. 2 is a diagram showing a schematic configuration of an embodiment of the present invention, and FIG. 3 is a diagram showing a state of a joint by a resistance welding apparatus according to the present invention. . 1 is a fixed electrode, 2 is a movable electrode, 3 is a pressurizing device,
4 is a power supply device, 5 is a liquid tank, 5a is a liquid, 6 is a liquid temperature control device, and X is a welded object.

Claims (1)

[Claims] 1 A fixed electrode and a movable electrode arranged so that their end faces face each other, and an application that biases the movable electrode toward the fixed electrode so that the object to be welded inserted between the two electrodes is pinched between the end faces of both electrodes. Resistance welding equipment consists of a pressure device and a power supply device that applies an appropriate voltage between both electrodes.The resistance welding device has a liquid tank filled with a substantially insulating liquid, and the temperature of the liquid is controlled by circulating and cooling the liquid. A resistance welding device comprising: a liquid temperature control device that maintains a constant temperature; the welding portions of a fixed electrode and a movable electrode are placed in the liquid in the liquid tank; and a workpiece to be welded is resistance welded in the liquid.