JPS58188581A - Press welding method by electrical heating - Google Patents

Abstract

PURPOSE:To reduce the margin for press welding in a press-welded part and to make final finishing easy in the case of performing press welding by electrical heating, by performing the press welding while applying strong and weak repetitive oscillations to press welding force. CONSTITUTION:The work 1a on a stationary side and the work 1b on a movable side are placed so as to face each other coaxially and the respective forward end parts 2a, 2b of a circular conical shape are butted to each other and are supported. A transformer 4 for electrical heating is connected to electrodes 3a, 3b to flow electric current between the works 1a, 1b, thereby heating the same electrically. Strong and weak oscillations are applied to the press welding force to be exerted between the works 1a, 1b to make the pressure generated by a press welding cylinder 6 oscillate constantly and to repeat the generation of large and small quantities of heat in the press welding part, whereby the average quantity of the heat to be generated is increased. The part S of oxide, etc. is forced easily outward by the heat input which is changed to large and small outputs, then said part is flattened to a tray shape and is easily removed. The rate of consumption A is reduced as well.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an energization heating pressure welding method.
More specifically, the present invention relates to a current-heating press-welding method that utilizes the Joule heat generated by the specific resistance of the metal materials to be pressed and the contact resistance yc between the metal materials to be pressed.

In energization heating and pressure welding, the materials to be welded with conical tips are butted against each other, current density is concentrated on these tips to facilitate energization heating and melting, and a pressure welding cylinder applies pressure between the materials to be welded. By adding this, oxides and the like formed in the pressure contact part are pushed out to the outside of the pressure contact part, thereby improving the mechanical properties and pressure contact reliability of the pressure contact part. However, in the conventional energization heating pressure welding method, the pressure welding part, that is, the material to be welded, is often consumed and is uneconomical, and it also requires a lot of man-hours to remove extruded oxides. Ta.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an energization heating pressure welding method that reduces the number of pressure welded parts and eliminates the above-mentioned conventional drawbacks.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows an apparatus used in an embodiment of the present invention, in which a fixed side pressure welding material /a and a movable side pressure welding material /b coaxially face each other, each having a conical tip Ja, , 2b are butt-supported. EE contact materials /a and /b are electric & J, respectively.
They are clamped and electrically connected by a and jb. A transformer for current heating is connected to the electrodes 3a and Jb, and the material to be welded under pressure /a.

0JIIJJ＠ Apply current I between Jb and heat it.
A pressure welding cylinder 6 is connected to the pressure welded material /b via a support member S.
are connected to each other, and the pressure welding cylinder bK presses the pressure welded material /b to the pressure welded material /a. This pressure contact force is set by the pressurizing side pressure P of the pressure contact cylinder B, and the back pressure -j pressure gauge. Pressure equipped/δ.

The contact resistance R of the tip portions 2a and 2b of Jb is a constant K.

Letting the pressing force be F, it is expressed as R=/, which is inversely proportional to the pressing force. In addition, the gel heat generated in that case is
'l' (and is proportional to the resistance value R.

This invention is characterized by applying strong and weak vibrations to the pressure welding force applied between the pressure welded materials /a and /b, and therefore, the pressure generated in the pressure welding cylinder B is made to have a constant vibration, Does the amount of heat generated at the pressure welding part repeatedly change in size? Strain to increase the average heat generation. Looking at this in Figure 1, we can see that the heating pressure welding time during which the heating current ■ is applied is
When the pressure P on the back pressure side is made to oscillate at a constant period for a period of 1, the pressure on the pressurizing side oscillates with the strength of P7 and p and -p at a period t. Figure 3 shows the shape of the ridges in the heat pressure welding process using the above method.
= (■) - (E) Pressure welding progresses as shown in the figure, and the final K ([
[0 state is reached, and finally the portion S pushed outward, such as the VcM compound, is removed. Then, by varying the magnitude of the input heat, the portion S of oxides, etc. is easily pushed outward, and this portion becomes dish-shaped, and the removal of this portion S is easy. (1) The consumption amount A indicated by K is also reduced.

Further, by appropriately adjusting the strength and/or repetition period of the pressure welding force, heat and pressure welding can be performed under optimal conditions.

As described above, the present invention reduces the pressure contact part of the pressure contact part,
Moreover, it has the effect of facilitating final finishing, improving economic efficiency, and further improving the quality of heat-pressure welding.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a device used in an embodiment of the present invention, Fig. 1 is also a time chart diagram, Fig. 3 (1),
FIG. 4 is a schematic diagram showing the aspect of the pressure welding part in the heat pressure welding process. /a, Jb...material to be welded, 2a, 2k;...tip, 3a, Jb...electrode, da...transformer, S...support S@, 6...press-fit cylinder. In the drawings, the same reference numerals indicate the same parts or parts equivalent to -fo. Agent Shin Kuwano −・

Claims (1)

[Scope of Claims] (/1 When the materials to be welded are brought into contact with each other and subjected to energized heat pressure welding, the pressure welding is performed by repeatedly increasing the strength and weakness of the pressure welding force. Current heating and pressure welding method 5 (
, 2) An energization heating pressure welding method according to claim 1, in which the pressure applied to the pressure welding cylinder 7' which applies pressure welding force to the materials to be welded is vibrated. (3) The energization heating pressure welding method according to claim 1, wherein at least one of the strength of the pressure welding force and the repetitive vibration period σ is adjusted as appropriate.