Method for Brazing a Tube Member and a Counterpart Member

Abstract

To provide a method for brazing and joining a pipe member end having a spool to a mated member, in which a brazing bond strength is increased and fluid leakage from a brazing part is prevented.SOLUTION: In a method for brazing an abutted part of an outer peripheral wall surface of a pipe member and an inner peripheral wall surface of a mated member, a pipe member end having a spool is inserted to a connection hole bored in the mated member, and at a neck lower part of the spool, a concavity is formed for infiltrating molten wax into a clearance part between a pipe end outer peripheral surface of a cylindrical metal member and the connection hole of the mated member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to a pipe member such as a metal pipe used as a supply path for automobiles or various machines and devices, etc., and a method of brazing and joining this pipe member to a mating member. More specifically, the present invention relates to a method of inserting a pipe end portion with a spool of the pipe member into the inside of the mating member and brazing and joining them.

Background Art

[0002] Conventionally, when brazing and joining the pipe end portion of a pipe member to a mating member, the pipe end portion of the pipe member is inserted into a connection hole drilled in the mating member, and a method of brazing and joining the contact portion between the outer peripheral wall surface of the pipe member and the inner peripheral wall surface of the mating member with copper brazing is generally performed. FIGS. 4 and 5 show an example thereof. A spool 11-2 having a diameter larger than the outer diameter of the metal part is formed on the outer periphery of the pipe end portion 11-1 of the cylindrical metal member (pipe member) 11. Then, with a copper paste brazing material (not shown in the drawing) disposed on the outer peripheral portion of the spool 11-2 of the pipe end portion 11-1 of the cylindrical metal member 11, the pipe end portion 11-1 of the cylindrical metal member 11 is inserted into a connection hole 12-1 drilled in the mating member (separate pipe, etc.) 12. After positioning (temporary fixing) in the inserted position by projection welding, the cylindrical metal member 11 and the mating member 12 are brazed and joined by a fillet 13 formed by heating in a continuous atmosphere furnace. A method is known.

[0003] In addition, as a brazing method for a metal pipe, while forming an expanded pipe portion at the tip of the cylindrical metal member and forming a flare at the tip of the expanded pipe portion, fitting a ring-shaped brazing material on the other metal pipe, inserting the end portion of the cylindrical metal member into the expanded pipe portion, and brazing by heating in a furnace in this state (see Patent Document 1), or in a method of brazing the outer peripheral wall surface of the pipe end portion of the pipe member to the inner peripheral wall surface of the mating member, fitting a brazing material ring on an annular engaging portion provided on the outer peripheral surface of the pipe end portion of the pipe member, inserting the pipe end portion of the pipe member with this brazing material ring into the mating member, and heating and melting the brazing material ring to braze the pipe end portion of the pipe member and the mating member (see Patent Document 2), etc. are disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional brazing joining method of the pipe member shown in FIGS. 4 and 5, that is, the pipe end of the cylindrical metal member (pipe member) 11 is inserted into the connection hole 12-1 formed in the mating member 12, and the contact portion between the outer peripheral wall surface of the cylindrical metal member 11 and the inner peripheral wall surface of the mating member 12 is brazed and joined. In this method, with a copper paste brazing material (not shown in the drawing) disposed on the portion of the spool 11-2 formed at the pipe end of the cylindrical metal member 11, the pipe end of the cylindrical metal member 11 is inserted into the connection hole 12-1 formed in the mating member 12, and in this state, the cylindrical metal member 11 and the mating member 12 are brazed and joined. There are the following problems. That is, in the conventional brazing joining method shown in FIG. 5, when brazing is performed by inserting the pipe end of the cylindrical metal member 11 with a spool into the connection hole 12-1 of the mating member 12, if brazing is performed in a state where there is no gap (substantially 0 mm) between the lower neck portion of the spool 11-2 of the cylindrical metal member 11 and the mating member 12, the molten copper brazing material does not penetrate (flow around) up to the gap 14 between the outer peripheral surface of the pipe end of the cylindrical metal member 11 and the connection hole 12-1 of the mating member 12. As shown in FIG. 5, it flows only to the front side of the mating member 12 and is brazed and joined only by the fillet 13 formed between the spool 11-2 of the cylindrical metal member 11 and the mating member 12. As a result, there is a problem that sufficient brazing joining strength cannot be obtained and the probability of fluid leakage from the brazed portion increases.

[0006] The present invention has been made to solve the problems of the conventional technology described above, and aims to propose a method of brazing a tubular member to a mating member, which enables molten copper brazing material to penetrate (flow around) from the neck portion of the spool to the gap between the end of the tubular member and the connecting hole of the mating member, thereby improving the brazing joint strength, preventing fluid leakage from the brazed portion, and reducing the welding current value when temporarily fixing the members by projection welding. [Means for solving the problem]

[0007] The method of brazing a tubular member and a mating member according to the present invention is a method of brazing a tubular metal member and a mating member by inserting the tube end of the tubular metal member into a connection hole formed in the mating member while a brazing material is placed on a spool portion formed on the tube end of the tubular metal member (tubular member), and brazing the tubular metal member to the mating member, the method comprising the steps of: injecting molten brazing material into an outer surface of the spool formed on the tube end of the tubular metal member and a neck portion on the tube end side of the spool, and causing the molten brazing material to penetrate into a gap between the outer peripheral surface of the tube end of the tubular metal member and the connection hole of the mating member. , and a recess for reducing the welding current value during projection welding in the temporary fixing of the outer peripheral surface of the pipe end portion of the cylindrical metal member and the mating member One or more in the circumferential direction of the spool by press working The method is characterized in that the outer surface of the spool portion and the contact surface of the mating member are temporarily fixed by projection welding, and then brazed.

[0008] In the brazing method, the shape of the recess formed in the neck portion of the spool of the tubular metal member is preferably a rectangle elongated in the circumferential direction (rectangular or a shape approximating a rectangle elongated in the circumferential direction), and the depth of the recess is preferably set according to the size of the spool (diameter, thickness in the longitudinal direction and radial direction of the tubular metal part, etc.). In addition, when a plurality of rectangular recesses elongated in the circumferential direction are formed in the spool neck portion of the cylindrical metal member, it is preferable that they are formed at desired intervals in the circumferential direction of the spool. Incidentally, the circumferential length and the number of formations of the concave portion are appropriately set according to the diameter of the cylindrical metal member, the size of the spool, etc., respectively. Although the brazing material is not particularly limited, a copper paste brazing material can be used.

Advantages of the Invention

[0009] According to the brazing method of the pipe member and the mating member of the present invention, when brazing by inserting the pipe end portion of the cylindrical metal member with a spool into the connection hole of the mating member, the concave portion formed in the lower portion of the spool neck and the gap between the outer peripheral surface of the pipe end portion of the pipe member and the inner peripheral surface of the connection hole of the mating member are connected, and a path for the molten brazing material to penetrate is formed. Therefore, the molten copper brazing material flows in the pipe axis direction, and the gap between the outer peripheral surface of the pipe end portion of the cylindrical metal member and the inner peripheral surface of the connection hole of the mating member is also filled and fixed with the brazing material. Therefore, sufficient brazing joint strength can be obtained, and leakage of fluid from the brazed portion can be prevented. Furthermore, according to the present invention, due to the action of the concave portion formed in the lower portion of the spool neck of the cylindrical metal member with a spool, the current for projection welding for positioning (temporary fixing) after inserting the cylindrical metal member can be reduced.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0011] The cylindrical metal member (metal tube) with a spool before brazing in one embodiment of the present invention will be described with reference to FIGS. 1 to 2. In the present invention, a rectangular recess 4 having a substantially rectangular shape that is long in the circumferential direction of the cylindrical metal member 1 and has a desired depth of depression is formed at four cross positions in the circumferential direction of the cylindrical metal member 1 at the lower neck portion of the annular spool 3 formed on the outer periphery of the tube end portion 2 of the cylindrical metal member 1. As a method for forming the rectangular recess 4, for example, it can be formed by pressing. Also, the circumferential length, depth of depression, number of formations, etc. of the rectangular recess 4 are appropriately determined according to the diameter, wall thickness, etc. of the cylindrical metal member 1. In this way, forming the rectangular recess 4 at the lower neck portion of the annular spool 3 is not only for the lower neck portion of the spool 3, but also to allow the melted brazing filler metal to penetrate into the gap 6 between the outer peripheral surface of the tube end portion 2 of the cylindrical metal member 1 and the inner peripheral surface of the connection hole 5-1 of the mating member 5, and fill the gap 6 with brazing filler metal.

[0012] Next, a brazing method for the cylindrical metal member 1 with the spool 3 having the above structure and the mating member will be described with reference to FIG. 3. That is, when brazing the cylindrical metal member 1 with the spool 3 shown in FIGS. 1 to 2 and the mating member 5, in the same manner as in the prior art, with a copper paste brazing filler metal (not shown in the drawing) disposed on the outer peripheral portion of the spool 3 at the tube end portion 2 of the cylindrical metal member 1, the tube end portion 2 of the cylindrical metal member 1 is inserted into the connection hole 5-1 formed in the mating member 5. At this time, the four rectangular recesses 4 formed at the lower neck portion of the spool 3 are connected to the gap 6 between the outer peripheral surface of the tube end portion 2 of the cylindrical metal member 1 and the inner peripheral surface of the connection hole 5-1 of the mating member 5, and a path for the melted brazing filler metal to penetrate is formed. Therefore, the melted brazing filler metal passes through the four rectangular recesses 4 formed at the lower neck portion of the spool 3 and also melts and flows into the gap 6 between the outer peripheral surface of the tube end portion 2 of the cylindrical metal member 1 and the inner peripheral surface of the connection hole 5-1 of the mating member 5, and the gap portion is also filled with brazing filler metal. Therefore, the tube end portion 2 of the cylindrical metal member 1 and the mating member 5 are joined by, for example, a fillet 8 formed by heating in a continuous atmosphere furnace as shown in FIG. 3 and a brazed portion 9 that has melted and solidified between the tube end portion 2 of the cylindrical metal member 1 and the mating member 5.

[0013] Thus, according to the present invention, a rectangular recess 4 is formed at the lower neck portion of the spool 3 of the cylindrical metal member 1 to communicate with the gap 6 between the outer peripheral surface of the pipe end portion 2 of the cylindrical metal member 1 and the inner peripheral surface of the connection hole 5-1 of the mating member 5. As a result, it is joined by the fillet 8 formed between the spool 3 of the cylindrical metal member 1 and the mating member 5 and the melted and solidified brazed portion 9 between the pipe end portion 2 and the mating member 5, so that the brazing between the cylindrical metal member 1 and the mating member 5 can be made more reliable. Further, due to the action of the rectangular recess 4 provided at the lower neck portion of the spool 3 of the cylindrical metal member 1, the current that has been flowing over the entire circumference of the cylindrical metal member 1 changes to an intermittent flow, making it possible to reduce the welding current value during temporary fixing by projection welding.

Explanation of Reference Numerals

[0014] 1 Cylindrical metal member 2 Pipe end portion 3 Spool 4 Rectangular recess 5 Mating member 5-1 Connection hole 6 Gap 8 Fillet 9 Brazed portion

Claims

1. In a method for brazing and joining a tubular metal member to a mating member, a brazing material is placed on a spool portion formed on the end of the tubular metal member, and the end of the tubular metal member is inserted into a connection hole formed in a mating member, the method comprising the steps of: a tubular metal member having a connecting hole and a connecting portion for connecting the tubular metal member to the connecting hole of the connecting portion, the tubular metal member being connected to the connecting portion of the connecting portion and the connecting portion being connected to the connecting portion ...

2. 2. The method for brazing a tubular member and a mating member according to claim 1, characterized in that the recess formed in the spool neck portion of the tubular metal member is circumferentially rectangular or approximately rectangular in shape.

3. 3. The method for brazing a tubular member and a mating member according to claim 1, wherein a plurality of circumferentially elongated rectangular recesses are formed in the spool neck portion of the tubular metal member at desired intervals around the spool.

Images