JP3822039B2 - Pipe member brazing joining method and pipe joining structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brazing joining method and a pipe joining structure used in a manufacturing process of a brazing product such as an intake manifold attached to an automobile engine.
[0002]
[Prior art]
In-furnace brazing is widely used as a joining method for joining a metal pipe to a counterpart metal member. For example, in the manufacturing process of the intake manifold, in-furnace brazing is performed to join a branch pipe to a collector or the like.
[0003]
FIG. 5 is a view showing an intake manifold. The intake manifold 1 includes an aluminum die-cast collector 2, a plurality of branch pipes 3 made of aluminum pipes, and aluminum for fixing the branch pipes 3 to the engine. A die-cast mounting portion 4 is integrated with a brazed structure. Each of the branch pipes 3 is curved into a predetermined shape, and both ends thereof are joined to the collector 2 and the mounting portion 4 on the engine side.
[0004]
Next, FIG. 6 shows a junction between the branch pipe 3 and the collector 2. The brazing material 5 is filled on the upper surface side of the collector 2 so that the melted material flows into the gap around the branch pipe 3. Similarly, as shown in FIG. 7, the brazing material 5 is filled on the upper surface side of the attachment portion 4 at the joint portion between the branch pipe 3 and the attachment portion 4 on the engine side.
[0005]
[Problems to be solved by the invention]
Conventionally, when brazing the intake manifold in the furnace, it is necessary to determine the position and structure of the joints in consideration of the furnace position so that the brazing material does not fall. There is a problem of receiving.
[0006]
Moreover, when setting in a furnace, what was temporarily assembled must be set with the attitude | position shown in FIG. However, since it is necessary to fill the brazing material 5, it is difficult to position the tip of the branch tube 3 with respect to the collector 2, so that the tip of the branch tube 3 may protrude gradually. For this reason, it is necessary to perform temporary attachment before brazing so that the position of the branch pipe 3 does not shift, and careful setup in advance is indispensable in order to ensure mounting accuracy.
[0007]
Therefore, the object of the present invention is to solve the problems of the prior art, determine the shape and position of the joint without considering the posture in the furnace, and can braze efficiently and accurately. An object of the present invention is to provide a method for brazing and joining pipe members and a pipe joint structure.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, in a brazing joining method for joining a metal pipe to a mating member by brazing in a furnace, a position at a predetermined distance from the tip of the metal pipe. A thick portion raised from the outer peripheral surface of the metal pipe is previously formed in the circumferential direction, and a first stepped hole capable of press-fitting the thick portion of the metal pipe is formed in the mating member, While inserting the metal pipe into the stepped hole, the brazing material is press-fitted between the thick portion of the metal pipe and the stepped portion of the first stepped hole, and the end surface of the metal pipe is moved to the first step. Abuts against the stepped portion of the second stepped hole formed in the innermost side in the press-fitting direction from the stepped hole, positions the metal pipe, and accommodates the metal pipe in the furnace in a temporarily assembled state with the mating member It is also characterized by brazing in the furnace It is.
[0009]
According to a fourth aspect of the present invention, in a pipe joint structure in which a metal pipe is joined to a mating member by brazing in a furnace, a circumferential direction is formed in advance at a position away from a tip of the metal pipe. been, has a thick portion that raised from the outer peripheral surface of the metal pipe, the wall thickness portion of the metal pipe is formed first stepped bore that can be press-fitted into the mating member, the apertured first stage The brazing material is filled between the thick part of the metal pipe inserted into the first stepped hole and the stepped part of the first stepped hole, and the end surface of the metal pipe is deepest in the press-fitting direction from the first stepped hole It is characterized by being brazed in the furnace in a state where it abuts against the stepped portion of the second stepped hole formed on the side.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a brazing joint method for pipe members and a pipe joint structure according to the present invention will be described with reference to the accompanying drawings.
First Embodiment FIG. 1 is a view showing an embodiment in which the present invention is applied to joining of a branch pipe of an intake manifold and a flange portion of a collector.
In FIG. 1, reference numeral 2 is a flange portion of the collector, and 4 is a mounting portion on the engine side. The branch pipes 10 are made of aluminum die cast and are arranged so that a plurality of them are bent and intersecting alternately, one end is attached to the flange part 2 of the aluminum die cast collector, and the other end is attached to the engine side. It is joined to the part 4 by brazing.
[0011]
FIG. 2 is a cross-sectional view showing a joint structure between the distal end portion of the branch pipe 10 and the flange portion 2.
A thick portion 12 is formed in the circumferential direction at the distal end portion of the branch pipe 10 so as to rise on the outer peripheral surface thereof. Since the thick portion 12 is press-fitted into a stepped hole as will be described later, it is desirable that the thick portion 12 has a smooth curved surface or a shape that increases the thickness with a taper. The thick portion 12 may be formed at the time of die casting, or may be formed in advance by build-up welding when joining. Moreover, you may make it comprise the thick part 12 by attaching another ring-shaped component.
[0012]
On the other hand, a stepped hole 14 having a first stepped portion 15 and a second stepped portion 16 located on the back side is formed in the flange portion 2 of the mating member. In this stepped hole 14, the opening from the inlet side to the first step portion 15 has a diameter D1, and the first step portion to the second step portion 16 have a diameter D2 smaller than D1. . The relationship between these hole diameters and the outer diameter of the branch pipe 10 is set as follows. That is, the maximum outer diameter of the thick portion 12 of the branch pipe 10 is set to be slightly larger than D1, and the outer diameter of the branch pipe 10 at the portion beyond the thick portion 12 is set to be substantially the same as or slightly smaller than D2. ing. In the case of this embodiment, the outer diameter of the branch pipe 10 in the portion ahead of the thick part 12 is the same as the reference outer diameter of the branch pipe 10. The depth of the stepped hole 14 is not particularly limited as long as the thick portion 12 can be press-fitted into the hole portion having the diameter D1.
[0013]
As the brazing material, a brazing material 18 formed in a ring shape is used as shown in FIG. In this case, the inner diameter of the brazing material 18 is smaller than the maximum outer diameter of the thick portion 12 of the branch pipe 10 and larger than the reference outer diameter, and the outer diameter is slightly larger than the hole diameter D1. Therefore, when the brazing material 18 is attached to the distal end portion of the branch pipe 10, the brazing material 18 is locked to the distal end side of the thick portion 12 and can be pressed into the stepped hole 14 in this state. Yes.
[0014]
Next, when the tip of the brazing material 18 is inserted into the stepped hole 14 with the brazing material 18 attached to the tip of the branch pipe 10, the brazing material 18 is inserted between the thick portion 12 and the first stepped portion 15. Can be packed. At this time, the end surface of the branch tube 10 abuts against the second step portion 16 and the thick portion 12 press-fits the brazing material 18, so that the branch tube 10 can be positioned at the same time. Moreover, since the brazing material 18 and the thick portion 12 are press-fitted, the branch pipe 10 and the flange portion are not misaligned in any posture, and the brazing material 18 does not fall off. Therefore, the temporary assembly before brazing can be performed with high accuracy.
[0015]
The provisional assembly of the other end portion of the branch pipe 10 and the mounting portion 4 is similar to the above in that a stepped hole is formed in the mounting portion 4 and a ring-shaped low end is provided at the end portion where the thick portion is provided. A material may be attached and press-fitted, or a conventional joining method as shown in FIG. 7 may be employed. The temporarily assembled intake manifold is set in a furnace and brazed.
As described above, the joint can be brazed without considering the posture in the furnace.
[0016]
Second Embodiment Next, FIG. 3 is a diagram showing a brazing joining method according to a second embodiment of the present invention.
The main point that this 2nd Embodiment differs from 1st Embodiment is the shape of the stepped hole 20 formed in the flange part 2 of a collector.
[0017]
In the case of the second embodiment, the stepped hole 20 formed in the flange portion 2 is formed with a tapered surface 22 that is inclined while being reduced in diameter toward the depth side of the hole. On the other hand, the thick portion 23 formed at the distal end portion of the branch pipe 10 is formed with a curved surface 24 inclined in the same direction so as to be in contact with the tapered surface 22.
[0018]
When the tip of the branch pipe 10 is press-fitted into the stepped hole 20 by causing the stepped hole 20 and the thick portion 23 to contact each other at the tapered surface 22 and the curved surface 24, the tapered surface 22 and the curved surface are formed. Since the wedges 24 exhibit a wedge action, press-fitting is facilitated, and a strong temporary assembly can be achieved, so that positional displacement can be reliably prevented.
[0019]
Third Embodiment Next, FIG. 4 is a diagram showing a brazing joining method according to a third embodiment of the present invention.
In the embodiment described so far, the thick portion raised on the outer peripheral surface is formed in the circumferential direction. In the third embodiment, the distal end portion of the branch tube 10 is provided with the main body of the branch tube 10. By forming the thin portion 26 that becomes thinner toward the tip with respect to the reference thickness, the tip portion of the branch pipe 10 is configured as a relative thick portion.
[0020]
On the other hand, a tapered surface 22 similar to that of the second embodiment is formed in the stepped hole 20 formed in the flange portion 2. The thin-walled portion 26 of the branch pipe 10 has a constant thickness at the portion where the second step portion 16 is fitted, but the portion where the brazing material 18 is attached is inclined until the reference thickness is reached. The tapered surface 27 is continuous. The tapered surface 27 is not necessarily formed, and the thickness may be changed stepwise. In that case, the reference wall thickness portion of the branch pipe may be press-fitted into the stepped hole 20.
[0021]
According to the third embodiment, as in the second embodiment, the press-fit can be easily performed using the wedge action between the tapered surfaces 22 and 27, and the temporary assembly can be firmly performed. Deviation can be reliably prevented.
[0022]
As described above, the present invention has been described as an embodiment of the connection between the branch pipe and the collector flange in the intake manifold, but the present invention can be widely applied to the connection between the metal pipe and the counterpart metal member.
[0023]
【The invention's effect】
As is clear from the above description, according to the present invention, the shape and position of the joint can be determined without considering the posture in the furnace, and brazing can be performed efficiently and accurately.
[Brief description of the drawings]
FIG. 1 is a partially cutaway view showing one embodiment of a method for brazing and joining pipe members according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of the joint portion of FIG.
FIG. 3 is a cross-sectional view showing a method for brazing and joining pipe members according to a second embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a method for brazing and joining pipe members according to a third embodiment of the present invention.
FIG. 5 is a side view showing an intake manifold as an example of articles joined by brazing.
FIG. 6 is a view showing a conventional brazing structure in an intake manifold.
FIG. 7 is a view showing a conventional brazing structure in an intake manifold.
[Explanation of symbols]
2 Collector flange portion 4 Engine side mounting portion 10 Branch pipe 12 Thick portion 14 Stepped hole 15 First step portion 16 Second step portion 18 Brazing material 20 Stepped hole 22 Tapered surface

Claims (5)

In the brazing joining method of joining a metal pipe to a mating member by brazing in the furnace,
A thick portion raised from the outer peripheral surface of the metal pipe is formed in advance in the circumferential direction at a predetermined distance from the tip of the metal pipe,
The mating member is formed with a first stepped hole capable of press-fitting the thick portion of the metal pipe,
While inserting the metal pipe into the stepped hole,
While pressing the brazing material between the thick portion of the metal pipe and the step portion of the first stepped hole,
Abutting the end face of the metal pipe against the stepped portion of the second stepped hole formed on the innermost side in the press-fitting direction from the first stepped hole, positioning the metal pipe,
A pipe member brazing and joining method, wherein the metal pipe is temporarily assembled with a mating member and accommodated in a furnace and brazing is performed in the furnace.   The pipe member brazing method according to claim 1, wherein the first stepped hole is formed with a tapered surface that contacts the thick portion.   With the basic thickness of the metal pipe as the thick portion, the outer diameter of the tip of the metal pipe is reduced, and the brazing material is formed between the thick portion of the metal pipe and the step portion of the first stepped hole. 3. The method of brazing and joining pipe members according to claim 1 or 2, wherein press fitting is performed between them. In a pipe joint structure in which a metal pipe is joined to a mating member by brazing in the furnace,
A thick portion raised from the outer peripheral surface of the metal pipe is formed in the circumferential direction in advance in a position at a predetermined distance from the tip of the metal pipe,
A first stepped hole into which the thick part of the metal pipe can be press-fitted into the mating member;
The brazing material is filled between the thick portion of the metal pipe inserted into the first stepped hole and the step portion of the first stepped hole, and the end surface of the metal pipe has the first stepped portion. A pipe joint structure characterized by being brazed in a furnace in a state of abutting against a stepped portion of a second stepped hole formed on the innermost side in the press-fitting direction from the hole.   The pipe joint structure according to claim 4, wherein the metal pipe is a branch pipe constituting an intake manifold made of aluminum die cast, and the mating member is a flange member of the intake manifold.

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