JPH0815656B2 - Brazing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to brazing of a product made of a plurality of steel plates for use in automobiles, industrial vehicles and the like.

(Prior Art) As a prior art of the present invention, there is a brazing method for copper, silver, brass, nickel, etc., and as a method for supplying the brazing material, paste brazing, preform brazing, copper plating method, copper cladding method There is.

Automotive torque converter pumps that are press-formed from rolled steel sheets use copper brazing material and braze blades to the shell pump outer and core pump inner. After attaching, paste copper wax and hairpin-shaped preform wax are set on the joint area, and then placed on the mesh belt of a continuous furnace in an non-oxidizing atmosphere for preheating and main heating.
Brazing is performed at 1090 ℃ ~ 1150 ℃, then gradually cooled to 300 ℃, and then taken out of the furnace for brazing.

Further, in the copper plating method and the copper clad method, a blade is formed from a steel plate in which copper is plated or clad in advance, and the blade is assembled to the shell pump outer and core pump inner and brazed in the continuous furnace in the same manner as described above. .

(Problems to be Solved by the Invention) However, in the above-mentioned brazing material and preform brazing material, it is necessary to set the brazing material to a portion where brazing is necessary, but the problem is that the number of man-hours increases when the brazing portion has a complicated shape. On the other hand, the method in which copper is added to the area where brazing is required beforehand by plating or cladding does not require setting the brazing material, but the cost required for plating and clad is high, so the paste brazing material, preform It is more cost effective than using brazing material.

In addition, a typical continuous brazing furnace for copper brazing has the melting point of copper
Because of the high temperature of 1083 ℃, the heating zone is large and long, 5 to 6m.

Furthermore, with base copper braze and preform copper braze, the man-hours required to set the brazing filler metal increase when there are many joints such as the TOKUKU converter pump, and the man-hours required for plating and cladding copper do not require the man-hours required for setting. In the case of plating, it takes too many man-hours to secure the film thickness of 40 μm necessary for brazing, resulting in cost up.

Although it is easy to increase the film thickness of the cladding, there is a problem that the cladding cannot be formed after the blade has been formed, and it can be formed only by using a rough material, resulting in a significantly poor yield.

SUMMARY OF THE INVENTION The present invention has a technical object in a method of brazing a steel plate such as a torque converter pump, to facilitate the supply of the brazing material and further reduce the heating zone of the brazing furnace.

[Structure of Invention]

(Means for Solving Problems) The technical measures taken to solve the problems are as follows.

In a method of brazing a plurality of steel plates and brazing a joint part of the brazed part, copper brazing is sprayed on the joint part by an arc or plasma, and the joint part is brazed by the spray coating. A brazing method characterized by:

Further, in the above brazing method, it is a brazing method of preheating the brazed product by high frequency induction heating before brazing the brazed product.

(Function) By rotating multiple steel plates in a pre-assembled state by high-frequency induction heating from the outside while rotating them, and by further adhering molten copper particles to the product by arc or plasma spraying, the product temperature rises and copper brazing Also, the adhesive strength of the alloy becomes large, and the brazing after the preliminary heating can be performed efficiently.

(Examples) Examples will be described below.

A in FIG. 1 shows a part of a torque converter pump for an automobile formed of a plurality of steel plates as a product to be brazed, 1 is a shell pump outer, 2 is a core pump inner, 3 is a blade, 4 is a core caulking Parts 5 are copper brazed parts, and all materials of the torque converter are press-formed with rolled steel plates.

B of FIG. 2 is a plasma (arc) spraying device of the torque converter pump A, 11 is plasma spraying, 12 is molten copper particles, 13 is a high frequency induction heating coil, and 14 is a rotating shaft.

The brazed product A is rotated at 100 γpm to rapidly preheat the shell pump outer 1 with the high frequency induction heating coil. (20
kw, frequency 400KHZ, 45 seconds at 400 ℃), at the time of its preheating, copper brazing is adhered to the joining site by plasma spraying or arc spraying. There is no problem even if they are preheated in another step, that is, after copper brazing is applied.

However, it is advantageous to perform them at the same time in terms of thermal efficiency and temperature uniformity of the work.

This is because the high frequency induction heating directly heats the shell pump outer 1, and the temperature rise of the blade and core pump inner is only due to the heat transfer from the shell pump outer, and with this alone, the temperature of the blade and shell pump outer is 50 ° C. Make a difference.

However, at this time, the core copper inner and the blades are heated by adhering the molten copper particles flying by plasma spraying from the core pump inner side, so that the whole brazed product has a uniform temperature. This means that the heat from the shell pump outer can be suppressed, so that the predetermined temperature can be easily reached with low heat input. And the strain which is a uniform temperature also becomes small.

Further, since the temperature of the product to be brazed is high, the adhesive strength of the copper brazing material is also large, so that peeling is difficult.

The method of supplying copper brazing material to the product to be brazed by plasma spraying or arc spraying is 100 by rotating the brazed product.
Since a film thickness of μm can be obtained, copper brazing can be supplied with high efficiency with almost no man-hours required.

FIG. 4 shows a heat pattern for copper brazing of a conventional torque converter, and shows a heat pattern for copper brazing of the torque converter of the present embodiment shown in FIG. 3. The high frequency induction heating as shown in FIG. By rapidly preheating up to 400 ° C. in the continuous furnace, it is possible to easily heat by the brazing temperature, so that the length of the heating zone can be halved.

In this example, the sample was preheated to 400 ° C., but may be heated to 500 ° C. However, if it is higher than this, strain increases and oxide scale adheres, which is not preferable.

Although the present embodiment is an example of brazing of a torque converter pump, it can be carried out for brazing of steel plates of industrial vehicles, home appliances and the like.

(Effects of the Invention) The present invention has the following effects. That is, (1) the brazing material can be easily supplied even if there are many copper brazing parts by supplying the copper brazing material by arc or plasma spraying.
(2) The number of steps for setting the brazing material can be reduced. (2) The number of steps can be reduced because the film can be made thicker than the plating method. Also, the cladding method can be done only at the stage of the material before forming multiple steel plates, but this method Since it can be easily done after molding, the material yield is improved.

(3) By rapidly preheating the brazed product by high-frequency induction heating, the brazing furnace can be downsized and the cost can be reduced.

(4) Since the temperature of the brazed product rises near 100 ° C. during thermal spraying, the thermal efficiency is improved by performing it simultaneously with the preheating of the high frequency induction heating.

(5) By spraying the copper braze at the time of preheating, the temperature of the sprayed part of the article to be brazed rises to 200 to 300 ° C., so that the adhesion of the braze increases and it becomes difficult to peel it off.

[Brief description of drawings]

1 (a) is a partially cutaway plan view of the torque converter pump, FIG. 1 (b) is a sectional view, FIG. 2 is a simplified explanatory view of the plasma spraying apparatus, and FIG. 3 is the torque converter of this embodiment. FIG. 4 is a heat pattern diagram of copper brazing of the pump, and FIG. 4 is a heat pattern diagram of copper brazing of the conventional torque converter pump. A: Torque converter pump, 1 ... Torque converter outer case, 3 ... Blade, 5 ... Copper brazing part, 11 ... Plasma spraying.

Continuation of front page (56) Reference JP 62-265185 (JP, A) JP 63-104780 (JP, A) JP 59-150662 (JP, A) JP 58-221670 (JP , A) Japanese Unexamined Patent Publication No. 1-133671 (JP, A) Shoukai 63-11166 (JP, U)

Claims (2)

[Claims] 1. A method for brazing a plurality of steel plates as a product to be brazed and brazing a joint part of the brazed product, wherein copper braze is sprayed on the joint part by an arc or plasma, A brazing method, which comprises brazing the joint portion. 2. The brazing method according to claim 1, wherein the brazed article is preheated by high frequency induction heating before brazing the joint portion.