JPS5846392B2 - Manufacturing method of laminated conductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminated conductor used in a current-carrying part of an electrical device.

Conductors made of laminated thin copper plates, etc. are used to connect fixed terminals and movable contact parts of current-carrying parts such as switches and circuit breakers, so they have excellent flexibility, thermal conductivity, and mechanical properties. It is desired that the material has excellent strength etc. and low contact resistance.

Therefore, it is mandatory to cover the contact surface with an Ag film in accordance with the standard (JEC181) in order to suppress temperature rise due to contact resistance.

As methods for joining this type of conductor, mechanical methods such as caulking and pressure welding, methods such as fusion welding, brazing, and soldering are known.

However, the caulking method has the disadvantages of poor current carrying performance, high processing costs due to the increased number of parts, and requires a device that generates a large pressing force because it performs strong mechanical processing on the material. Furthermore, since it is significantly deformed due to heavy processing, secondary processing is required to correct this.

In addition, the brazing method has the problem of deterioration of the mechanical properties of the base materials to be joined due to high heating, and the fusion welding method has the problem of maintaining the initial dimensions in addition to the problems mentioned in the brazing method. There is also the problem that the number of laminated sheets is limited due to difficulties.

Furthermore, brazing and soldering methods require the removal of flux as a post-processing process, which leads to problems with the formation of voids in the joints, and the production of cadmium oxide fumes that impair the working environment.
me) involves processing problems.

In addition, when applying an Ag film to the contact surface, partial plating is performed after the conductors are bonded, but with this method, the pretreatment liquid inside the lamination cannot be completely removed, leading to early rusting. This will lead to corrosion and damage.

In view of the problems of the conventional bonding methods described above, the present invention provides a method for bonding laminated conductors in which bonding can be easily performed using a simple device, and the conductors have good mechanical and electrical properties after bonding. The purpose is to provide.

In order to achieve this object, the method for manufacturing a laminated conductor according to the present invention involves inserting a conductive member in an overlapping manner between two electrodes having parallel surfaces facing each other, and moving the two electrodes to apply force to the conductive member. The method is characterized in that they are heated by applying electricity between the electrodes while applying pressure, and then rapidly cooled and bonded. 270℃～810℃
It is preferable to heat it to ℃ and then quickly cool it in water.

Next, a method for joining laminated conductors according to the present invention and embodiments will be described with reference to the drawings.

First, the method of the present invention will be explained.

FIG. 1 is a longitudinal sectional view of a bonding device used for bonding conductive members according to the present invention.

In FIG. 1, electrodes 1 and 2 made of carbon are arranged so that their parallel surfaces face each other, and electrode 2 is moved by air pressure generated within a cylinder 4.

Stack and insert the required number of flat conductive members 3 between the electrodes 1 and 2, move the electrodes 2 in the direction of the arrow using the cylinder 4, and place the conductive members 3 on the sword surface by 0.02 to 1.
kV/- (if it is less than 0.02, the pressure is not sufficient; if it exceeds 1, the conductive member will undergo plastic deformation), and the electrodes 1 and 2 are energized by a power supply (not shown) (approximately 1500OA, both AC and DC available).

Current between electrodes 1 and 2 flows through laminated conductive member 3
However, using this Joule heat, the temperature is raised to a certain temperature [T (270 to 810°C) in about 15 seconds as shown in the heating temperature control curve in Figure 2 in a certain atmosphere (for example, in the atmosphere), and
Thereafter, after maintaining T in the range of ±50° C. for 1 to 3 minutes by turning the current ON and OFF, the laminated conductive member 3 is left in the above atmosphere as necessary to cool down to some extent,
Furthermore, the bonding is completed by quenching in water.

Since this method involves bonding in the atmosphere, rapid cooling is required to suppress the formation of an oxide film during the cooling process.

Next, examples using the method of the present invention will be described.

Example 1 As the conductive member 3, 180 thin copper plates having a thickness of 0.1 mar were stacked and bonded by the method described above.

The atmosphere is atmospheric.

The pressure applied to the thin copper plate is 0.6k on the pressurized surface of the thin copper plate.
g/-.

In addition, the heating temperature T is the melting point Tm (1356°
T(OK)/Tm(0K)=04~0°8 for K)
A value within the range that satisfies this condition, here 650°C.

In this example, electricity is supplied between electrodes 1 and 2 (AC 14800A)
The temperature was raised to 650°C in 15 seconds using
It was maintained for a minute.

Next, the laminated thin copper plate was left in the air to cool to 300°C, and then rapidly cooled in ordinary tap water (about 15°C).

Figure 3 shows a laminated cross section of the thin copper plates 3 thus joined.
In the 0x micrograph, an orderly boundary between the bonded thin copper plates 3 due to solid phase diffusion can be seen.

Furthermore, it can be confirmed that each thin copper plate 3 maintains its respective structure, is less affected by bonding, and maintains the flexibility of the thin copper plate 3 itself.

Example 2 A laminated thin copper plate (the thickness of one plate is Q, lam) and a copper plate (
2) were overlapped and bonded in the same manner as in Example 1.

FIG. 4 is a micrograph of the cross section of the laminated conductor thus obtained, magnified 126 times.

FIG. 5 is a photograph of this laminated conductor after it has been tightened and used for a long period of time with holes for passing through the tightening screws.

As shown in Fig. 5, there is no deformation of the hole despite long-term tightening, and in the cross-sectional micrograph of Fig. 4, there is no disturbance in each layer of the thin copper plate 3 and copper plate 5. Flexibility prevents the tightening screw seating surface from sinking due to creep,
The influence on the contact surface due to the tightening between the conductive members can be improved.

Example 3 O01I in which a 3μ thick Ag plating layer was applied on both sides of the outermost surface of a laminated thin copper plate 3 (thickness of one sheet is Q, 1ffff).
Thin copper plates 6 of IM thickness were stacked and bonded in the same manner as in Example 1.

FIG. 6 is a micrograph of the cross section of the laminated conductor thus obtained, magnified 170 times.

As shown in FIG. 6, the Ag layer is not affected by the diffusion bonding and maintains the state before bonding in a straight line.

Therefore, an Ag plating process is not required as a post-treatment, there is no fear of corrosion damage, and excellent performance can be achieved as a contact surface while bonded.

Example 4 A copper plate 7 (2 mm thick) and a knitted copper wire 8 were stacked and bonded in the same manner as in Example 1.

FIG. 7 is a photograph of the conductor thus obtained.

It can be used as a conductor of a small current capacity, high frequency switch, and as in Example 2, it can improve the depression caused by creep of the screw fastening seat surface and the mechanical properties, making it an excellent contact end.

According to the present invention, it is possible to manufacture bonding conductors for electrical equipment to be mass-produced using a simple device, and the present invention is also applicable to small-volume production of a wide variety of products, so the product price can be reduced.

In addition, due to the physical, chemical, mechanical properties and characteristics of solid phase bonding, the electrical properties are also good and remain the same as before bonding, and there are no problems associated with bonding methods using high heat.
The resulting improvement is significant, as it reduces the number of man-hours, such as eliminating the need for Ag plating after bonding.

Furthermore, when thin plates with a wall thickness of about 0.1 mm are laminated, flexibility can be added.

Note that the method of the present invention does not preclude the use of other bonding methods in combination. For example, when pressurizing and heating the conductive member with an electrode, a brazing agent may be dripped onto the conductive member.

[Brief explanation of drawings]

Figure 1 shows the longitudinal cross-section of a bonding device for carrying out the method for manufacturing laminated conductors according to the present invention, Figure 2 is a diagram of the heating temperature control curve in the method of the present invention, and Figure 3 shows the laminated conductor manufactured by the method of the present invention. FIGS. 4 and 5 are micrographs of the cross section of the first embodiment of the laminated conductor at a magnification of 170 times, and FIGS. A front photograph, FIG. 6 is a 170x micrograph of the cross section of the third example of the laminated conductor manufactured by the method of the present invention, and FIG. 7 is a fourth example of the laminated conductor manufactured by the method of the present invention. This is a front photo. 1.2... Electrode, 3... Thin copper plate, 4... Cylinder, 5.7... Copper plate, 6... Ag plated copper plate, 8...
...Knitted copper wire.

Claims (1)

[Claims] 1. At least two conductive members are stacked and inserted between two electrodes having parallel surfaces facing each other, and the two electrodes are moved so that the conductive member is heated to 0.02 kli/myA. to 1
A method for manufacturing a laminated conductor, which comprises heating these to 270°C to 810°C by passing current between the electrodes while applying a pressure of kq/-, and then rapidly cooling and joining them. 2. A method for producing a laminated conductor according to claim 1, which comprises rapidly cooling in water.