JPH07115199B2 - Method for resistance welding thin plate using elastic body and work support used in the method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a resistance welding of a thin plate work (hereinafter, simply referred to as a "work"), and a welding method for reducing a strain generated during the welding, and a method for the welding. Regarding work support.

[0002]

2. Description of the Related Art Conventionally, for example, in order to reduce the weight of an aircraft, light alloy thin plates such as aluminum and duralumin are often overlaid and welded by resistance welding to be used for flaps, moving blades, and the like. In the resistance welding, as shown in FIG. 13, the stacked works W1 and W2 are pressed and sandwiched by the upper electrode 21 and the lower electrode 22, and then the works are welded by energizing them while applying pressure. Therefore, the welded portion (the portion to be welded) W3 of the work is heated by Joule heat, melted, and then solidified and joined.

[0003]

However, when the plate thickness of the work is extremely thin (for example, about 0.3 mm to 0.4 mm), the above-mentioned upper electrode and the lower electrode are simply used.
If the method of welding while stacking and stacking a plurality of works under pressure, the following problems occur. (1) Distortion may occur in the welded part during welding, and the strain may spread to the vicinity of the welded part of the work. At this time, the work is
The welded part may bend or the joint surface may rise. This tendency increases as the workpiece becomes thinner, and in particular,
It is noticeable when the work has a processing strain generated in the previous process. (2) When welding multiple parts to the same work, the distortion of the weld part that occurs during welding may cause poor weldability of the joint surface between the work parts of other weld parts to be welded next and cause welding defects. Interferes with proper welding. If the joint surface is not familiar,
Specifically, excessive work lifting, excessive dents, irregular or irregular dents, electrode scratches near the dents, scattering, cracking, deformation of pores, irregular nuggets, etc., damage, etc. occur. (3) The distortion of the welded portion generated during welding does not recover even after welding and remains concave or convex. In this case, the distortion of the welded portion spreads or accumulates around the welded portion, and the work assembled by welding, that is, a part or the whole of the welded product is deformed. (4) Such defective welding, that is, welding defects and distortion of the welded portion and deformation of the welded product, also deteriorate the welding quality such as surface smoothness and appearance design (good appearance). This deterioration in quality significantly deteriorates the function and commercial value of the product using the welded product, and sometimes also deteriorates the workability and the processing quality of the subsequent process. (5) Therefore, in order to manufacture a welded product with excellent quality, it is necessary to prevent distortion of the weld portion that occurs during welding as much as possible and prevent defective welding. However, strict welding condition management has to rely on the skill of the worker, and no solution has been found.

[0004]

According to the present invention, first, after a plurality of stacked plate-like works are placed on an elastic body,
The work is sandwiched and held by the upper electrode, the lower electrode and the elastic body, and the upper electrode and the lower electrode are energized,
By the method of welding a plurality of the works to each other,
Further, a work provided on a lower electrode holder having a lower electrode holder having a height adjustable support base and an elastic body provided on the upper surface of the support base and penetrating a lower electrode for resistance welding. The above-mentioned problem was solved by the support tool.

[0005]

[Function] For resistance welding of a plurality of works, after placing a plurality of stacked plate-like works on the elastic body, the work is pinched and held by the upper electrode, the lower electrode and the elastic body. , The upper electrode and the lower electrode are energized. The elastic body presses the works by elasticity during welding, maintains the close contact between the works, and suppresses the distortion generated in the welded portion.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The work supporting member 30 is detachably provided in a lower electrode holder 31 which is integral with the lower electrode 32 and which penetrates the shaft-shaped lower electrode 32. The work support tool 30 includes an adjustment nut 33 screw-engaged with each other, a support base 34, and a rubber (shore hardness of about 40 to 8) provided on the upper surface of the support base 34.
0) elastic body 35. Electrode through holes 39 and 40 are formed in the support base 34 and the elastic body 35. Between the lower electrode 32 and the electrode through holes 39, 40,
A gap S is formed. A shaft-shaped upper electrode 36 faces the lower electrode 32.

Before welding the works W1 and W2, the height of the elastic body 35 is set by using a test piece (not shown) by rotating the adjusting nut 33 to a height at which welding failure can be prevented. At this time, the elastic body 35 is substantially flush with the lower electrode 32,
Alternatively, it is adjusted higher than the lower electrode 32.

When welding the works W1 and W2, the works W1 and W2 are placed on the elastic body 35 in a stacked state, and then the upper electrode 36 is lowered so that the upper electrode 36, the lower electrode 32 and the elastic body 35 work together. Hold W1 and W2. Work W
When a current is applied to both electrodes 36 and 32 while sandwiching 1 and W2, welded portion W3 is heated by Joule heat, melted, and then solidified and joined. At this time, looking at the appearance of the welded portion W3, if there is distortion remaining in the welded portion W3, deformation of the depressions, or lifting of the workpieces W1 and W2, the adjusting nut 33 is rotated and the elastic body 35 is rotated. Readjust the height.

The workpieces W1 and W2 during welding are mounted on the upper electrode 3
6 and the elastic body 35 and the lower electrode 32, the contact area W4 is formed on the joint surface between the works with the welding portion W3 as the center. The contact area W4 is improved in contact area and adhesion as compared with the conventional case by the support of the works W1 and W2 near the welded portion by the elastic body 35 and the elastic action of the elastic body 35.
The strain generated in the contact area W4 due to heating and cooling is absorbed by the elastic body 35 and partly dispersed in the vicinity of the welded portion W3.

The elastic body 35 is made up of a wide range of works W1,
By supporting W2, it is possible to correct the inclination of the works W1 and W2 and reduce the deviation of the distortion of the welded portion W3. That is, the works W1 and W2 are supported by the elastic body 35 and are not welded in an inclined state as shown in FIG. If the welding is performed while tilted, the upper and lower electrodes 36 and 32 and the works W1 and W2 come into partial contact with each other, and as shown in FIG. This causes a local deviation indicated by W5 and W6, which causes distortion. Specifically, the surface of the workpieces W1 and W2 that are in contact with the electrodes 36 and 32 is distorted by dents, and the surface of the workpieces W1 and W2 on the back side thereof is distorted by protrusions.

The workpieces W1 and W2 have a lower temperature as they are farther from the welded portion W3, and the influence of heat is reduced, so that the distortion of the workpieces during welding is reduced. Therefore, the elastic body 3
The shape of 5 is as follows. As shown in FIG.
On the elastic body 35, a plurality of tapering projections 37 are radially formed around the electrode through hole 40 at substantially equal intervals. The projecting piece 37 has a smaller cross-sectional area as it approaches the tip, and the elasticity is gradually reduced. Therefore, each of the projecting pieces 37 presses the contacting work W2 by elastic force during welding,
The distortion during welding can be suppressed, and the distortion occurring in the welded portion W3 and the periphery of the welded portion during welding is reduced. The force with which the elastic body 35 presses the works W1 and W2 during welding,
The distribution of the reaction force between the works W1 and W2 is as shown in FIG. Further, since the protrusion 37 is tapered, the welding heat can easily escape.

Eight grooves 38 are formed in the base of the projecting piece 37 in a radial pattern with the electrode through holes 40 at the center at substantially equal intervals. The groove 38 is formed to reduce interference between adjacent projecting pieces 37 at the base when the projecting piece 37 is bent. When the work W1 and W2 are distorted in the preceding process and the work is deformed, the entire work support 30 is moved by the gap S in the horizontal direction (left and right in FIG. 1) and rotated. Then, the projecting piece 37 of the elastic body 35 is opposed to the processing strain, and then welding is performed.

In addition to the shape shown in FIG. 2, there are elastic bodies having the following shapes. Elastic body 135 shown in FIG.
Has a shape in which the tips of the eight protruding pieces 137 are cut off. The elastic body 135 also has an electrode through hole 140,
Eight grooves 138 are formed. The elastic body 235 shown in FIG. 4 has an electrode through hole 240 and eight projecting pieces 237. However, the groove is not formed. The elastic body 335 shown in FIG. 5 has an electrode through hole 340 and eight projecting pieces 337 whose tip is cut off. No groove is formed in this elastic body 335 either. Elastic body 43 shown in FIG.
In No. 5, only the electrode through hole 440 is formed, and the protruding piece and the groove are not formed. Therefore, the elastic body 435 has a ring shape. Elastic bodies 35, 135, 235, 335,
The outer diameters of 435 are all substantially the same. Also, the grooves 38, 1
In addition to the U shape, the shape of 38 is a square shape, a V shape, and a Y shape like the grooves 238, 338, and 438 shown in FIGS. 7, 8 and 9.
It may be letter-shaped.

[0014]

When the plate-shaped work is welded by the resistance welding method according to the first aspect or by using the work supporting tool for resistance welding according to the second aspect, the distortion of the weld portion generated during the welding is caused by the elastic body. Since it can be suppressed by, even if it is a thin plate work, without deforming the work,
Welding can be performed reliably. In addition, since the distortion can be suppressed, the process of repairing the defective welding or the shape correcting process which has been conventionally performed is not required, and the productivity of the welding process can be improved. Further, since welding can be performed without causing deformation of the work, it becomes possible to accurately perform processing and assembly in other subsequent steps. Further, since the welding can be performed without causing the work to be deformed, the quality and the commercial value of the welded work or the product using the welded work can be improved. When the elastic body is provided with a plurality of tapered protrusions, the temperature becomes lower as the distance from the welded portion increases, and the work can be supported by the elastic force according to the tendency that the strain of the work becomes smaller. Therefore, it is possible to prevent unnecessary elasticity from being applied to the work. Further, when the projecting piece is tapered, the welding heat can be released, unnecessary melting is eliminated, and it is possible to prevent the occurrence of irregular recesses in the welded portion, electrode scratches, and the like. When a groove is formed between the projecting pieces of the elastic body as in claim 4, even if one projecting piece bends due to welding distortion, the bending is not transmitted to the adjacent projecting piece, so that it corresponds to each projecting piece. Distortion can be surely suppressed. When the elastic body has a ring shape as described in claim 5, a large distortion of the welded portion can be reliably suppressed in the entire elastic body.

[Brief description of drawings]

FIG. 1 is a view showing a state in which a work piece for resistance welding of the present invention is mounted on a lower electrode, and is a cross-sectional view taken along the longitudinal direction of the lower electrode.

FIG. 2 is a perspective view of an elastic body.

FIG. 3 is a perspective view of another elastic body.

FIG. 4 is a perspective view of another elastic body.

FIG. 5 is a perspective view of another elastic body.

FIG. 6 is a perspective view of another elastic body.

FIG. 7 is a front view of a groove having another shape.

FIG. 8 is a front view of a groove having another shape.

FIG. 9 is a front view of a groove having another shape.

FIG. 10 is a state diagram when a workpiece is welded in an oblique state.

FIG. 11 is a plan view of a welded portion when a workpiece is welded in an oblique state.

FIG. 12 is a diagram showing a distribution state of a force applied to a work when welding is performed using the work support tool.

FIG. 13 is a state diagram in the case of resistance welding a work without using the work support tool of the present invention.

[Explanation of symbols]

 W1, W2 work 30 work support 31 lower electrode holder 32 lower electrode 34 support stand 35, 135, 235, 335, 435, elastic body 36 upper electrode 37, 137, 237, 337 projecting piece 38, 138, 238, 338, 438 groove 40, 140, 240, 340, 440 electrode through hole

Claims (5)

[Claims] 1. A plurality of stacked plate-like works are placed on an elastic body, and the works are clamped and held by an upper electrode, a lower electrode and the elastic body, and the upper electrode and the A resistance welding method comprising energizing a lower electrode to weld a plurality of the works together. 2. A lower electrode holder having a lower electrode, which has a height adjustable support base and an elastic body provided on the upper surface of the support base, and which penetrates a lower electrode for resistance welding. A work support tool for resistance welding, characterized in that 3. The elastic body includes an electrode through hole through which the lower electrode penetrates, and a plurality of tapered projecting pieces radially formed around the electrode through hole. Work support tool for resistance welding. 4. The elastic body has grooves radially formed around the electrode through hole between the projecting pieces.
Workpiece support for resistance welding described. 5. The elastic body has a ring shape.
The work support tool for resistance welding according to claim 2.