JPH0160359B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for welding copper to stainless steel or Fernico alloys by Teig welding.

Conventionally, for example, when manufacturing an ion pump, in order to degas the inside of the pump, a copper pipe b is attached to the pump body a as shown in the first diagram, the body a is heated from the outside, and the gas generated inside is passed through the pipe b. Suction is carried out using a degassing device c connected to the other end, but in this case the copper pipe b must be directly and airtightly attached by welding to a stainless steel flange d, which releases relatively little gas into the vacuum. Since this is not possible, it is common practice to first attach the copper pipe b to a cast iron flange e such as UFC-70 by silver brazing, and then attach it to a stainless steel flange d with bolts f. However, silver brazing is relatively expensive, and if a flange other than stainless steel such as UFC-70 is used, a large amount of gas will be emitted into the vacuum, which is undesirable. It is recommended that it be installed. Vacuum equipment is also required to attach copper pipes to a Fernico alloy (trade name: Kovar), but this also involves the same inconveniences as mentioned above because other materials are interposed.

The purpose of the present invention is to solve these inconveniences by bringing a copper base material and a stainless steel or Fernico alloy welded member to be welded into contact with each other, and When performing Teig welding with the side end as the welding surface, the welded material should be welded so that the thickness of the welded material from the corresponding contact surface at the welded surface is approximately twice the thickness of the welded surface of the base material. The welding surface of the base material is raised above the welding surface of the welded component by forming grooves, etc. in the component, and the difference in level created there is approximately 60% or less of the thickness of the base material. Features.

To explain one example with reference to the attached drawings, Fig. 2 shows a case where a stainless steel flange member to be welded 2 is welded to a base material 1 of a copper pipe, and the base material 1 is formed into the weld member 2. It is brought into contact by being inserted into the through hole 3, and Teig welding is performed using the side end of the contact surface 4 as the welding surface 5. In this case, the thickness A of the welding surface 5a from the corresponding contact surface 4 of the welded member 2 is the thickness A of the welding surface 5b from the contact surface 4 of the base material 1, as shown in the third diagram.
In the illustrated example, the thickness A is adjusted by forming a concave groove 6 around the through hole 3 of the member 2 to be welded. Further, the welding surface 5b of the base material 1 is raised above the welding surface 5a of the welded member 2, and the step C is approximately equal to the thickness A.
After adjusting to 60% or less, Teig welding is performed and the second
A product as shown is obtained.

Specifically, if the thickness B of the base material 1 is 1 mm, the groove 6 is formed so that the thickness A is 2 mm, and the step C is
Adjusted to 0.3 to 0.4mm. The depth of the groove 6 is 2
Although it is preferable that the depth is 1 mm or more, it may be possible to form a depth of only 1 mm due to limitations such as the shape of the welded member 2. In such a case, A is 1.5 mm and B is 1.5 mm as shown in the fourth figure. Even if it is 0.7 mm, C is adjusted to 0.3 to 0.4 mm, which is less than 60% of A.

When Teig welding a welded member 2 made of a Fernico alloy to a copper base material 1, for example, as shown in Figure 5, A is 1.5 mm, B is 0.7 mm, and C is 0.2 mm. In this case, the thickness A was formed to a predetermined dimension by providing a notch 7 in place of the groove 6. Reference numeral 8 in the figure indicates a stainless steel member that is further welded to the member 2 to be welded.

When the base metal is copper, it has good thermal conductivity, and the welding heat escapes during Teig welding, and the time it takes to reach the melting temperature does not match that of stainless steel or Fernico alloy parts to be welded, so both parts are fused together. However, as in the present invention, the thickness of the welded member 2 at the welding surface 5 is A is twice the thickness B of base material 1, and base material 1 has a step C that is 60% or less of its thickness B.
If the base metal 1 is raised up with the
melts and fuses together with the workpiece 2 to be welded, making it possible to perform welding without air circulation. The reason why both materials 1 and 2 melt at the same time in accordance with the present invention is that the base material 1 is raised up and the heat-receiving area increases, and the thickness of the welded material 2 is limited, which improves its heat dissipation and melts. This is thought to be due to the delay in start time, etc.

In this way, according to the present invention, the thickness A of the stainless steel or Fernico alloy member to be welded at the welding surface is approximately twice the thickness B of the copper base material, and the thickness of the base material is Since the height difference C is about 60% or less of B, it is possible to easily Teig weld the two materials, which are often used in vacuum equipment, with good airtightness, which simplifies the manufacturing process. There is.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is a cut-away side view of the embodiment of the present invention, Fig. 3 is a cut-away side view of the state in which the base metal and the workpiece to be welded are in contact before welding, and Fig. 4 and FIG. 5 are cutaway side views of another embodiment of the present invention. 1... Base metal, 2... Welded member, 4... Contact surface, 5...
Welding surface, A, B...thickness, C...step, 6...concave groove.

Claims (1)

[Claims] 1. When Teig welding is performed by bringing a copper base metal and a stainless steel or Fernico alloy workpiece to be welded into contact with each other, and using the side edges of the contact surfaces as the welding surfaces, A concave groove or the like is formed in the workpiece to be welded so that the thickness of the workpiece from the corresponding contact surface is approximately twice the thickness of the welding surface of the base metal. Teig welding is used to weld copper to stainless steel or Fernico alloy using Teig welding, which is characterized by raising the welding surface above the welding surface of the workpiece and making the step created there approximately 60% or less of the thickness of the base material. How to weld to.