JPS639920B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of welding a thin spring material to a base material. Traditionally, Fe and Cu have been used as automotive electrical components, for example.
An electrical contact for a relay was used in which a contact material was welded to one end of a plated base material, and a spring material was welded to the opposite end of the base material. However, such electric contacts are insufficient in welding strength between the base material and the spring material and in flat twisting strength, and there has been a strong demand for improvement. However, due to the unique shape of the spring material, there are very few parts that can be welded to the base material, so multi-point welding, which is effective in improving welding strength and torsional strength, is difficult. Furthermore, even if multi-point welding were possible, the thin spring material would become brittle due to heat effects, and the number of man-hours would increase, resulting in poor productivity. Furthermore, there is a method of installing a ring projection on the base material and welding the spring material at this part, but since it is difficult to process the ring projection, the ring projection may be large or small, tilted, etc. The accuracy varies significantly. As a result, the flatness of the welded portion of the spring material may not be achieved, or only one half of the spring material may be welded, resulting in low and uneven welding strength, resulting in instability. Moreover, ring projection welding requires high precision in attaching the upper and lower electrodes, which is difficult to satisfy. For the above reasons, the welding strength and torsion strength between the base material and the spring material have not yet been improved. The present invention was made in view of the current situation, and it is an object of the present invention to provide a method of welding a spring material that can reliably improve the welding strength and torsional strength of the spring material to the base material, reduce variations, and stabilize it. It is something to do. The spring material welding method of the present invention has a wall thickness of 0.5
When resistance welding a spring material of mm or less to a base material, a spherical projection is provided on the surface of the base material to which the spring material is welded, and the spherical projection is attached to the tip of the electrode that presses the spring material. This method is characterized in that welding is performed using an electrode provided with a ring-shaped protrusion having an inner diameter approximately equal to or larger than that of the excision. The details will be explained below with reference to the drawings. As shown in Fig. 1, a spherical projection 3 is provided on the surface of the base material 1 to which the spring material 2 is to be welded by pressing it with a punch from the opposite side. A flat spring material 2 is arranged on the projection 3 side of the base material 1. Then, an electrode 4 with a flat tip was provided from the base material 1 side, and a ring-shaped protrusion 5 having an inner diameter approximately the same as or larger than the projection 3 of the base material 1 was provided at the tip from the spring material 2 side. When the electrodes 6 are moved forward and the base material 1 and the spring material 2 are pressurized and energized, the spring material 2 is pressed against the base material 1 as shown in FIG.
Using the top of the projection 3 as a fulcrum, the electrode 6
is deformed into a spherical shape in the recess 7 of the electrode 6, and is pressed almost uniformly against the ring-shaped protrusion 5 of the electrode 6. At the same time as the base material 1 and the spring material 2 are brought into pressure contact, the current is concentrated here. The mixture flows and is melted and joined in a ring shape as shown in FIG. 3, and a ring-shaped recess 9 is formed on the surface of the melted and joined portion 8. The welding strength and twisting strength of the spring material 2 welded to the base material 1 in this manner are extremely high and stable with little variation. Note that the shape of the electrode 6 is not limited to that shown in FIGS. 1 and 2, and any shape is sufficient as long as the tip of the electrode becomes a ring-shaped protrusion as shown in FIGS. 4a, b, and c. It is something. The ring-shaped protrusion 5 and the recess 7 of the electrode 6 can be made by machining, or can be made by using a flat electrode with the spring material 2.
Another method is to weld the weld to the spherical projection 3 of the base material 1 about 10 times, thereby gradually increasing the size of the welding mark. Next, in order to clarify the effects of the spring material welding method according to the present invention, specific examples and conventional examples thereof will be described. Example As shown in Fig. 1, a spherical projector with a radius of curvature of 1 mm, a diameter of 1.2 mm, and a height of 0.2 mm was attached to the welding surface of the spring material of the base material 1 of 0.6 mm thickness, which was made of Fe with Cu plating of 6 to 10 μm. A flat spring material 2 made of 2W/OBe-Cu and having a thickness of 0.2 mm is arranged on the projection 3 side of this base material 1. Then, from the base material 1 side, there is an electrode 4 with a flat tip, and from the spring material 2 side, an electrode with a ring-shaped protrusion 5 with an inner diameter of 1.0 mm and an outer diameter of 2 mm, and a spherical recess 7 with a depth of 0.13 mm on the tip surface. 6, respectively, and remove the base material 1 and the spring material 2.
They were welded by applying pressure and electricity as shown in FIG. Conventional example: A ring projection with a diameter of 1.2 mm and a semicircular cross section and a width of 0.4 mm is provided on the spring material welding surface of a base material with the same dimensions and the same material as the example, and the ring projection side of this base material is provided with the ring projection. A spring material of the same size and material is arranged. Then, electrodes with flat tips were advanced from both the base material and the spring material side, and the base material and the spring material were welded by applying pressure and electricity. However, when the welding strength and torsional strength of 100 pieces of each of the spring materials of the example and the conventional example welded to the base material were measured, the results shown in the table below were obtained.

[Table] As is clear from the above table, the welding strength and torsional strength of the spring material to the base material in the example are much higher than those of the conventional example and are stable with less variation. As detailed above, the spring material welding method of the present invention has the excellent effect of greatly improving the welding strength and torsional strength of the spring material to the base material, and reducing variation and stabilizing it. .

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing the steps of the spring material welding method of the present invention, and FIG. 4 is a cross-sectional view showing another electrode according to the present invention. DESCRIPTION OF SYMBOLS 1... Base material, 2... Spring material, 3... Spherical projection, 4... Electrode with a flat tip, 5... Ring-shaped protrusion, 6... Having a recess 5 on the tip surface. Electrode, 7... recess of electrode 6, 8... melted joint portion, 9... annular recess.

Claims (1)

[Claims] 1. When resistance welding a spring material with a wall thickness of 0.5 mm or less to a base material, a spherical projection is provided on the surface of the base material where the spring material is to be welded, and a spherical projection is provided at the tip of the electrode that presses the spring material. 1. A method of welding a spring material, the method comprising welding using an electrode provided with a ring-shaped projection having an inner diameter approximately equal to or larger than that of a spherical projection.