JPS5966971A - Brazing method - Google Patents

Abstract

PURPOSE:To form easily a brazed joint having high quality in the stage of brazing both members having a cylindrical joint surface by forming beforehand irregular ruggedness on the joint surfaces of both members. CONSTITUTION:Brazing of a seat 2 of a Co-Cr-W alloy, Ni-Cr-B-Si alloy, etc. having excellent resistance to heat, corrosion and wear to a mushroom-shaped valve body 1 made of a heat resisting steel to be used for a diesel engine is accomplished by spraying steel balls having a small diameter from a shot blast nozzle 3 onto the joint surface 1a of the body 1 to form irregular ruggedness on the surface 1a. Ruggedness is similarly formed on the joint part of a seat material 2 according to need, and a brazing material is cast into the space formed on the rugged face by butting both rugged surfaces. Such a joint part where a uniform space such as with a cylindrical body is difficult to form in the entire joint part is thus easily brazed.

Description

[Detailed description of the invention] This paper relates to improvements in the brazing method used since then.

Conventional. The "Roui" method is one of the joining methods that has been used for a long time as a simple method for joining. In this method, the gap between the joint surfaces is one of the important factors that affects the quality of the solder joint (particularly the strength of the joint). 1, that is, when the gap becomes wide. Insufficient soldering or voids may occur, or conversely, if the gaps are too small. The influx of wax is obstructed, and both of these factors lead to a decrease in heavy responsibility. Therefore, various methods have been used to maintain the gap between the joint surfaces of both joints in an ideal state at all times, but most of these methods depend on the joint shape and the precision of machining. .

However, depending on the wax printing method and the shape of the joint (joint shape), it is often difficult to maintain a constant 1/1 gap using the conventional method. Especially for cylindrical joints, it is difficult to maintain a uniform gap during brazing.

Even if it were possible, it would often require extremely complex and high-precision machining, which would require a lot of time and money. Therefore, it has been desired to develop a method that can reliably and easily secure the gap between the bonding surfaces.

The present invention was developed in view of this situation. The gap between the joint surfaces is the key to ensuring quality in the former wax capital. By simply and reliably maintaining a predetermined gap. The present invention provides a brazing method that can easily produce high-quality brazed joints.

That is, 1 the present invention has irregular irregularities 11+1 in advance on the joint surfaces of both joint parts that are machined to the required dimensions.
The method is characterized in that the above-mentioned members are joined by forming the above-mentioned parts into a shape FjV and supplying wax into the gaps created by the uneven surfaces. According to this method, the gaps created by the uneven surfaces processed in advance are , the solder easily penetrates, and there are almost no defective parts due to so-called soldering.

'1: The effects of the present invention are remarkable in joining one cylindrical member.

Hereinafter, a specific and detailed explanation of the present invention will be given by way of examples.

Figures 1 to 4 show the dimensions of one embodiment of the present invention.
The figure shows the configuration of a mushroom-shaped valve used in diesel engines.

In the figure, (1) is the mushroom-shaped valve body.

81J Jl Shrine', Nimonic material, or a heat-reduced steel with a considerable advantage of these materials is used. (2) Mushroom-shaped valve seam) A component of MIS, which is generally heat resistant and corrosion resistant.

Excellent wear resistance. '$11EhaCo-Or
-W meeting.

Special materials such as Ni Or B-8i alloy are used. (1B) and (2a) are the above members (1) and (
2) The respective joint surfaces are joined using a solder.

In this case, wax printing is generally performed using the in-furnace wax method in a vacuum or an inert atmosphere.

Other heating means may also be used. Rouri is.

Because mushroom-shaped valves are used at relatively high temperatures.

Generally, the brazing temperature is 900 to 1,200°C.
I-hot wax is used.

Joint surface (18) of this valve body (1) and notebook member (2)
Since the shape of (2a) is a joint shape consisting of a part of a conical shape, the gap between the joint surfaces of both parts is maintained uniformly. When it is misaligned, a gap is created where the gap becomes zero, and the inflow of wax is inhibited in this area.

In fact, there were cases where brazing defects occurred.

21 to 4 show the application of the present invention to a mushroom-shaped valve having the brazed structure shown in FIG. This is an example of one method for forming a surface. '1-i.e., the 21st
Regarding ¥1, the joint surface (18) of the valve body (1) is blasted beforehand with a small diameter steel ball ejected from the shot blast nozzle (3) to prevent any defects. A regular uneven surface (1'a) is formed. The surface roughness of this bonded uneven surface (after shot blasting of 1'nl is
Generally, the blasting time is controlled so that the depth is approximately 0.09 to 0.10. Of course, the deaf system and O
・Depending on the brazing conditions, the surface roughness t may exceed the above range.
You can also rub it.

On the other hand, in addition to the joint surface (la) of the valve body (1), is it also possible to perform blasting on the joint surface (2a) of the seat member (2)?In the case of the mushroom-shaped valve of the example,
Generally, the sheet system (2) has quite high hardness (llv5oo
~700) Almost no effect can be expected from soothing or blasting.

As a result, an irregular uneven surface (1'a) is formed on the joint surface (la) of the valve body (1). Even if there is a slight deviation in the setting of a certain number of songs, at least the joint surface (la)
The gap between the recesses can be maintained. Furthermore, since the gaps are arranged irregularly over the entire joint surface, it is easy for the solder to flow into the nine gaps, and defects such as holes are extremely reduced.

Figure 3 shows this situation schematically.

FIG. 4 shows a part of it enlarged.

In FIGS. 3 and 4, (1) shows the valve body, (2) shows the seat portion +J', and (4) shows the brazing filler metal that has flowed into the joint surface. Even if the joint surface (18) of the valve body (1) has an irregularly uneven surface due to blasting.

Although there are countless metal contact areas between the valve body (1) and the valve head (2), the individual contact areas between the two are extremely small, so in reality, the brazing filler metal (4) Due to the erosion action, the wax (4) easily flows between the valve body (1) and the seat member (2), resulting in a sound joint.

As described above, one aspect of the present invention is a method for performing C-brazing while reliably maintaining the gap between the joint surfaces, particularly when brazing two members having cylindrical joint surfaces.

This is a particularly useful method for obtaining a brazed joint of a product 'a' that has never been seen before.

[Brief explanation of the drawing]

Fig. 1 shows a partial side surface 1 of a mushroom valve showing an embodiment of the method of the present invention, Fig. 2 is a schematic diagram of a mode of forming an uneven surface by the method of the present invention, and Fig. 8 shows a joint obtained by the method of the present invention. FIG. No. 41-1 is an enlarged cross-sectional view of a part of FIG. 3. (1) Mushroom-shaped valve body, (2) 7-toe member,
<3) Niblasting nozzle, <4): Brazing metal, (1aH2a): Joint surface of both parts.

Claims (1)

[Claims] On the joint surfaces of both parts to be joined that have been processed to predetermined dimensions,
A soldering method whose special purpose is to join the above-mentioned members by forming an irregularly uneven surface and supplying wax to the gap created by the uneven surface.