JPH07106464B2 - Ultrasonic spot welding method for metal plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for welding metal plates to each other and is effectively applied to, for example, ultrasonic spot welding, resistance spot welding, and the like.

[Prior art and its problems]

As a conventional welding method, for example, JP-A-53-12
There is a publication of 5480. In the welding method shown in this publication,
The two members to be welded are brought into contact with each other, and ultrasonic vibration is applied to the contacting points to weld the members to be welded to each other. In this welding method, when the welding area is very small compared to the contact areas of the members to be welded that are in contact with each other, even if a slight displacement of the positions of the members to be welded occurs, the welding Has almost no effect on.

In this welding method, when the contact area of the non-welded member is much larger than the area of the volume portion, the effect of slight misalignment can be neglected. When the area of the welded member is about the same as that of the welded member, there is a problem that the position of the welded member is displaced by a slight vibration. Therefore, there is a problem that it is very difficult to manage the relative positions of the members to be welded to each other.

[Means for solving problems]

In the present invention, the following measures are taken to solve the above problems. That is, a recessed portion that is approximately equal to the outer shape of the second metal plate is formed in the first metal plate. Then, a plurality of legs are formed on the outer peripheral portion of the second metal plate, and the second metal plate is positioned within the recess of the first metal plate. After that, the relative position of the second metal plate with respect to the first metal plate is maintained, and then the first metal plate and the second metal plate are welded to each other.

〔Example〕

Next, an example in which the present invention is applied to ultrasonic spot welding will be described.

FIG. 1 is a sectional view showing a state in which this embodiment is carried out, and FIG. 2 is a plan view showing a state in which the position of the second metal plate is held on the first metal plate. In FIG. 1, reference numeral 1 is an ultrasonic oscillator that oscillates ultrasonic waves. The electrical oscillation signal oscillated by the ultrasonic oscillator 1 is transmitted to the ultrasonic oscillator 2. Upon receiving this signal, the ultrasonic vibrator 2 generates minute vibrations, and the minute vibrations are transmitted to the ultrasonic horn 3 connected to the ultrasonic vibrator 2. The ultrasonic horn 3 increases this minute vibration and transmits it to the tool 4 connected to this ultrasonic horn 3. The tool 4 vibrates in the direction indicated by the arrow R in the figure, and in the present embodiment, the amplitude is 30 μ at a frequency of 20 KHz.

The first metal plate 5, which is the member to be welded, is placed on the anvil 9. A recess 12 is formed at the welded portion of the first metal plate 5. An inclined portion 8 having an inclination of about 23 degrees is formed on the peripheral edge of the hollow portion 12. The recess 12 has an outer shape that is substantially the same as the outer shape of the second metal plate 6.

As can be seen from FIG. 2, the second metal plate 6 has a disk portion 12 having a disk shape, and the outer peripheral edge of the disk portion 12 is equally spaced.
The foot portion 11 is provided at several places and protrudes outward. Second
The metal plate 6 of is made of a material such as aluminum or copper, and has a foot portion.
11 can be easily deformed when a force is applied in its protruding direction. When the second metal plate 6 is positioned in the recess 12, the tip of the foot portion 11 of the second metal plate 6 can secure a minute distance from the inclined portion 8 of the recess 12. The size is as follows.

It is necessary to form at least three legs 11, and the legs 11 are arranged so that only the tips of the legs 11 contact the recesses 12 and the outer peripheral edges of the discs 12 do not contact the inclined portions 8 of the recesses 12. There is.

Next, the welding procedure in this embodiment will be described. First, the recesses 12 as described above are formed on the first metal plate 5 at required locations. Then, the second metal plate 6 having the above-described shape is positioned in the recess 12. At this time, since the inclined portion 8 is formed on the peripheral edge of the recess 12, the second metal plate 6 can be easily located in the recess 12.

When the second metal plate 6 is located in the recess 12 and the relative position of the second metal plate 5 with respect to the first metal plate 5 is secured, the tool 4 is moved to the second metal plate 6 The upper surface is brought into contact with the second metal plate 6, and a pressing force is applied to the second metal plate 6, and then ultrasonic vibration is applied. As a result, the second metal plate 6 vibrates in the direction of arrow R in FIG. 1 with an amplitude of 30 μ at 20 KHz, and frictional heat is generated at the contact surface between the second metal plate 6 and the first metal plate 5. . The frictional heat and ultrasonic vibrations cause a plastic flow on the surface of the welding material due to the removal of the surface oxide film and the impurities at the contact point of the welding material, resulting in atomic bonding or interatomic diffusion bonding, and the first metal plate 5 And the second metal plate 6 are solid-phase bonded.

At this time, a foot portion 11 is formed on the outer peripheral portion of the second metal plate 6, and the foot portion 11 is arranged in the inclined portion 8 of the recess portion 12 while maintaining a minute distance. The vibration of the second metal plate 6 is not restricted. That is, if it is assumed that the entire outer periphery of the second metal plate 6 is in contact with the inclined portion 8 of the recess 12, the second metal plate 6
That is, the vibration of the above is restrained by the contact between the outer periphery and the inclined portion of the recess 12, and an unstable state may occur in the welding state. However, in this embodiment, a plurality of legs are formed on the outer peripheral portion of the second metal plate 6, and only the legs contact the inner peripheral wall of the recess 12, that is, the inclined portion 8. Therefore, even if the moving force is further applied after the foot portion 11 comes into contact with the inclined portion 8, the foot portion 11 can be moved by bending or buckling, and the vibration of the second metal plate 5 is restrained. There is no need to worry.

If the outer periphery of the second metal plate 5 is entirely in contact with the inclined portion 8 of the recess 12, the external force applied to the metal plate 5 and the metal plate 6 and the thermal stress due to the temperature change of the atmosphere are affected. It is transmitted to the joint between the metal plate 5 and the metal plate 6 through the contact point, causing a problem of peeling and greatly affecting the welding quality. However, in the present embodiment, the entire circumference of the second metal plate 6 does not come into contact, and the foot portion
Since only the tip of 11 can contact the inner wall of the recess 12, that is, the inclined portion 8, the thermal stress as described above is applied to the foot 11.
Is deformed to be absorbed, and the welded portion between the first metal plate 5 and the second metal plate 6 is not separated.

In addition, in the present embodiment, the second metal plate 6 has a shape in which a plurality of foot portions 11 are symmetrically provided on the outer periphery of the disk portion 12,
The number of the legs 11 is not particularly limited to six. Further, the disc portion 12 is not limited to the disc shape, and may be, for example, a triangular shape or a hexagonal shape.
Further, although the inclined portion 8 of the recess 12 is formed in this embodiment, the inclined portion 8 is formed for the purpose of easily positioning the second metal plate 6 in the recess 12. The recessed portion 12 may be provided without forming the inclined portion 8 in particular.

The materials of the first metal plate 5 and the second metal plate 6 are applicable to all weldable metals such as aluminum and copper.

In addition, although an example of ultrasonic spot welding has been described in the present embodiment, it can be applied to other welding methods such as resistance spot welding.

Further, in the present embodiment, the ultrasonic wave applied to the second metal plate 6 had a frequency of 20 KHz and an amplitude of 30 μ. However, if the welding conditions allow welding, this value is selected at an appropriate time. It is possible.

〔The invention's effect〕

As described above, by using the welding method of the present invention, by positioning the second metal plate in the recess formed in the first metal plate, it is possible to easily secure the position of each other, Even if some external vibration force is applied to this metal plate, the positions of both metal plates do not shift. Therefore, the first
It is possible to perform welding continuously without having to worry about the relative positional deviation between the metal plate and the second metal plate. Further, by using the welding method of the present invention, it is possible to simplify a conventional jig for securing the relative positions of the first metal plate and the second metal plate, a position control confirmation device, or the like. In addition, it has an excellent effect that the facility cost can be reduced and the welding process can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a plan view showing a first metal plate and a second metal plate. 1 ... Ultrasonic oscillator, 2 ... Ultrasonic transducer, 3 ... Ultrasonic horn, 4 ... Tool, 5 ... First metal plate, 6 ... Second metal plate, 11 ... Foot , 12 …… Dimple part, 13 …… Disc part.

Claims (1)

[Claims] 1. A welding method for welding a second metal plate onto a first metal plate, the outer peripheral portion of the second metal plate projecting outward from an outer peripheral edge thereof, At least three foot portions that can be deformed in the protruding direction are formed, and an outer shape that is substantially the same as the outer shape that connects the outer ends of the foot portions of the second metal plate is formed at the welding location on the first metal plate. Forming a recessed portion having, the foot portion is formed in an array on the outer peripheral edge of the second metal plate so that only the tip end portion thereof can contact the inner peripheral wall of the recessed portion, An ultrasonic spot welding method for a metal plate, comprising: fitting a metal plate into the recess of the first metal plate and then performing welding.