JPS5881578A - Resistance welding device - Google Patents

Abstract

PURPOSE:To uniform temperature rise at the joining boundary and attain stable joining in a device that welds a conductor on the surface of an end of a conductor, by constructing specifically the press energizing face of electrode of at least one side. CONSTITUTION:For instance, an end of the pedestal 1 of the first conductor and a contact point 2 of the second conductor are held by the first and second electrodes 3, 4 and press energized. At least one of press energizing face of the electrodes 3, 4 is constituted of a conductor and an insulator, or two kinds of conductors different in electric resistance. When the insulator 9 is provided on the end face side of the end part 101 of the pedestal 1 of press energizing face of the electrode 4, and energized as mentioned above, welding current flows deviating to opposite side 102 of the end face direction of the end part 101 as shown by broken line arrows, and heat is generated there positively. Consequently, heat currents C, C' are formed in the direction 102 opposite to the end face direction of the end part 101. In this case, temperature difference between points A and B can be made as small as (TA-TB) by setting the contact area between the insulator 9 and pedestal 1 according to the size of the contact point 2 and pedestal 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resistance welding device, for example, a resistance welding device for spot welding a contact point to one end of a pedestal.

FIG. 1 is a block diagram showing a conventional resistance welding device. 1st
In the figure, one end (1
A contact point (2), which is a second conductor, is spot welded to the surface of 01). The first electrode (3) is the contact point (2
). The second electrode (4) is the first electrode (
3) and is in contact with the back surface of the pedestal (1). The welding power source (5) is the first one. Second electrode (3),' (4)
connected between.

Next, the operation of the conventional device will be explained. 1st. Second electrode (3
), (4) between the contact (2) and one end of the pedestal (1) (
101) and pressurized, the welding power source (5) energizes the contact (2) and one end (10) due to Joule heat generation.
1) were joined.

However, with such a so-called direct current type spot welding machine, the contact (2) is attached to one end of the pedestal (1) (
101), bonding failures were likely to occur due to uneven temperature rise at the bonding interface.
This will be explained based on the diagram.

FIG. 2 is a conceptual diagram showing a welding state using a conventional resistance welding device. In Figure 2, the bonding layer (6) is attached to the pedestal (1).
This is the layer where one end (101) of the contact point (2) is joined. The eluted metal (7) is metal eluted from the bonding layer (6). The defective joint (8) is located at one end (101) of the pedestal (1).
) and the contact (2) where the bonding layer (6) is not formed.

That is, as shown in FIG. 2, one end (101
), a bonding layer (6) is formed on the end side, and the eluted metal (7) drips down significantly. On the other hand, there is a strong tendency for bonding defects (8) such as notches to occur on the side opposite to the end of one end (101) of the pedestal (1). Next, the cause of the occurrence of such a joint defect portion (8) will be explained based on FIG. 8.

FIG. 8 is an explanatory diagram of causes of defects in conventional resistance welding equipment. As shown in FIG. 8, one end (101
), heat saturation occurs at the end face of the base (1), but conversely, at the other end, which is the opposite side, a flow path C is formed in the longitudinal direction. Therefore, A at the bonding interface
The temperature from point to point B has a steep downward slope like TA-TB, and as a result of joining, melting (8) occurs on the end side of one end (101) of the pedestal (1).

This invention was made in order to eliminate the drawbacks of the conventional ones as described above. Second electrode (3), (
By configuring at least one pressurized current-carrying surface in 4) with a conductor and an insulator or two types of conductors with different electrical resistivities, the temperature rise at the bonding interface is made uniform, thereby achieving stable bonding. The object of the present invention is to provide a resistance welding device that can perform the following steps. An embodiment of the present invention will be described below based on the drawings.

FIG. 4 is a configuration diagram showing an embodiment of a resistance welding apparatus according to the present invention. In the figure, the same parts as in FIG. 1 are given the same reference numerals. In FIG. 4, the insulator (9) is located at one end (1
01) is provided on the end face side.

Next, the operation of the apparatus of this invention will be explained using FIG.

Now, connect one end (101) of the pedestal (1), which is the first conductor, and the contact (2), which is the second conductor, to the first. Second electrode (3
) and (4) and apply pressure, the welding current flows to one end (1) of the pedestal (1) as shown by the broken line arrow in
01) flows toward the opposite side (102), actively generating heat on the opposite side (102). As a result, the pedestal (1
) toward the end face of one end (101) and the opposite side (102)
In the direction, heat flows C' and C are formed. In this case, by setting the contact surface of the insulator (9) with the pedestal (1) to an appropriate value according to the dimensions of the contact (2) and the pedestal (1), points A and B at the bonding interface can be set. The temperature difference between T and T shown in Figure 5 is
It is extremely small like A-TB, does not have bonding defects (8) such as dripping of eluted metal (7) or notches, and has a stable bonding layer (6). is obtained.

In the above embodiment, an insulator (9) is attached to a part of the pressurized current-carrying surface of the second electrode (4), and the current distribution is adjusted to the pedestal (1).
Although it is biased toward the other end (102), the insulator (9) may be attached to the pressurized current-carrying surface of the first electrode (3). Also, instead of the insulator (9), the first. Second electrode (3), (4
) may be provided.

As described above, according to the present invention, the first. This has the effect of making it possible to equalize the temperature rise at the bonding interface of the second conductor and significantly improving the stability of the bond.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing a conventional resistance welding device, Fig. 2 is a conceptual diagram showing a joining state by a conventional resistance welding device, Fig. 8 is an explanatory diagram of causes of defects in a conventional resistance welding device, and Fig. 4 is a configuration diagram showing an embodiment of a resistance welding device according to the present invention,
FIG. 6 is an explanatory diagram of the operation of this invention. In the figures, the same parts in each figure are given the same reference numerals.
(1) is the pedestal, (101) is one end, (102) is the other end, (2) is the contact, (3) and (4) are the first. The second electrode (5) is a welding power source, and (9) is an insulator. Agent Patent Attorney Makoto Kuzuno - Figure 1 -429 - Procedural Amendment (Voluntary) Commissioner of the Japan Patent Office 1, Indication of Case Patent Application No. 178564/1982 2
, Title of the invention Resistance welding device 3, Relationship with the case of the person making the amendment Patent applicant (1) 5. Column 6 for detailed explanation of the invention in the specification subject to the amendment 6. Contents of the amendment (1) Specification, No. On page 5, line 6, [Correct the ``contact surface'' to ``contact area.''Libel'AA (2)

Claims (2)

[Claims] (1) a first conductor to which a second conductor is bonded to the surface of one end; The first conductor holds the second conductor and is energized under pressure.
a second electrode; A resistance welding device characterized in that at least one pressurizing current-carrying surface of the second electrode is composed of a conductor and an insulator or two types of conductors having different electrical resistivities. (2) The insulator or the conductor with higher electrical resistivity of the two types of conductors is provided on the end surface side of one end of the first conductor of the pressurized current-carrying surface. resistance welding equipment.