JPH0966878A - Pipe joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate shifting of a joint part in case of joining a pipe using an adhesive and heighten the joining strength. SOLUTION: An aluminum pipe 6, the outer peripheral surface 9 of which is coated with an adhesive 10, is inserted in a pipe fitting hole 2, and the inserted part of the pipe 6 in the pipe fitting hole 2 is expanded. Plural parts of the outer peripheral surface 9 of the pipe 6 are pressed to the wall surface 14 of the pipe fitting hole 2 by expansion of the pipe 6, and also a clearance 11 0.01-0.05mm formed between the non-pressed pipe outer peripheral surface part 9a and the wall surface 14 is filled with an adhesive like a thin film to make the outer peripheral surface 9 and the wall surface 14 adhere to each other uniformly and firmly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joining method, for example, a method for joining an aluminum pipe to a surge tank or a flange of an intake manifold.

[0002]

2. Description of the Related Art As a method of joining pipes joined by using an adhesive, for example, a joining method described in JP-A-58-209673 is known. The joining method described in the publication is to insert a pipe into a tubular fitting hole at a minute interval, fill the minute interval portion with a thermosetting resin structural adhesive, and heat cure the adhesive. The filling of the adhesive is performed by directly injecting the adhesive into a minute gap between the pipe and the tubular fitting hole or applying the adhesive to the outer periphery of the end of the pipe and inserting the pipe into the tubular fitting hole. This is done by applying an adhesive to the inner periphery of the tubular fitting hole and inserting the pipe into the tubular fitting hole.

[0003]

However, when the adhesive is directly injected into the clearance after the pipe is inserted into the tubular fitting hole, the pipe and the tubular fitting hole are likely to be misaligned and the adhesive is injected into the clearance. The adhesive has uneven thickness,
There is a problem that a position shift occurs at the joint after the bonding is completed. Also, when the adhesive is applied to the outer periphery of the end of the pipe and inserted into the tubular fitting hole, or when the adhesive is applied to the inner periphery of the tubular fitting hole and the pipe is inserted, the filling of the adhesive is not performed. There is a problem that it is not perfect and an unfilled portion is generated, so that sufficient strength cannot be obtained. Therefore, the present invention has been made in order to solve the above problems, and an object of the present invention is to provide a method for joining pipes having a large joint strength without axial misalignment between the pipe and the tubular fitting hole.

[0004]

According to a first aspect of the present invention, there is provided a pipe joining method, wherein the pipe is inserted into a pipe fitting hole having an inner diameter capable of maintaining a predetermined clearance between the pipe and the pipe to be joined. In a method for joining pipes, wherein a clearance between the pipe fitting hole and an adhesive is filled to fix the pipe in the pipe fitting hole, at least an outer peripheral surface of the pipe or a wall surface of the pipe fitting hole is provided. After applying the adhesive to one side, the pipe is inserted into the pipe fitting hole, the insertion portion of the pipe into the pipe fitting hole is expanded, and a plurality of locations on the outer peripheral surface of the pipe are attached to the wall surface. While crimping, the outer peripheral surface portion of the uncompressed pipe and the wall surface are coaxially arranged, and the adhesive is filled in the clearance between the outer peripheral surface portion of the uncompressed pipe and the wall surface to form the outer peripheral surface of the uncompressed pipe. To bond the face and the wall And butterflies. The pipe joining method according to a second aspect is characterized in that a clearance between the uncompressed pipe outer peripheral surface portion and the wall surface is set to 0.01 to 0.05 mm. The pipe joining method according to claim 3 is
The adhesive is applied to at least one of the outer peripheral surface and the wall surface of the pipe in a cylindrical shape. The pipe joining method according to claim 4, wherein the adhesive is a thermosetting resin adhesive, and the uncompressed outer peripheral surface of the pipe and the wall surface are adhered by the thermosetting resin adhesive, The thermosetting resin adhesive is heat-cured.

An adhesive is applied to at least one of the outer peripheral surface of the pipe and the wall surface of the pipe fitting hole, the pipe is inserted into the pipe fitting hole, and the portion of the pipe inserted into the pipe fitting hole is fixed. When the pipe is expanded and a plurality of locations on the outer peripheral surface of the pipe are pressure-bonded to the wall surface of the pipe fitting hole, there is no or almost no adhesive between the pressure-bonded pipe outer peripheral surface portion and the wall surface. An adhesive is filled in the clearance between the crimped pipe outer peripheral surface portion and the wall surface, and the uncompressed pipe outer peripheral surface portion and the wall surface are bonded. At this time, the pipe is expanded substantially evenly in the radial direction, and the uncompressed outer peripheral surface of the pipe and the wall surface are coaxially arranged, and a plurality of portions of the outer peripheral surface are pressed against the wall surface. There is no axial misalignment between the pipe and the pipe fitting hole. When the clearance between the unbonded pipe outer peripheral surface portion and the wall surface is 0.01 to 0.05 mm, the adhesive is filled in a thin film in the clearance, and the pipe outer peripheral surface portion and the wall surface are uniform and strong. To be joined to. Further, when the pipe is inserted into the pipe fitting hole in a state where the adhesive is applied in a cylindrical shape on at least one of the outer peripheral surface of the pipe and the wall surface of the pipe fitting hole, and the pipe is expanded, no pressure is applied. The adhesive between the outer peripheral surface of the pipe and the wall surface is almost completely filled with the adhesive, and high adhesive strength is obtained. Furthermore, the adhesive is a thermosetting resin adhesive,
When the thermosetting resin adhesive is adhered to the outer peripheral surface portion of the pipe which has not been pressure-bonded and the wall surface by the thermosetting resin adhesive, the thermosetting resin adhesive is heat-cured to more firmly bond the outer peripheral surface and the wall surface. To be done.

[0006]

EXAMPLE An example in which the pipe joining method of the present invention is applied to joining a surge tank of an intake manifold to an aluminum pipe and joining a flange to an aluminum pipe is shown in FIGS.
3 will be described. As shown in FIG. 1, the intake manifold 1 has two pipe fitting holes 2 on each side, two pipe fitting holes 2 in total.
A surge tank 3 having the above, a flange 5 having pipe fitting holes 4 arranged in a line, and four aluminum pipes 6 connecting the pipe fitting hole 2 of the surge tank 3 and the pipe fitting hole 4 of the flange 5. Composed of. The surge tank 3 and the flange 5 are aluminum castings (JIS AC2B, AC4C, etc.) formed by gravity casting, die casting, and high pressure casting, and the aluminum pipe 6 is an aluminum alloy (AC6061, A606).
3003) extruded material or drawn material. One end 7 of the aluminum pipe 6 on the surge tank 3 side is joined so as to communicate with the pipe fitting hole 2 of the surge tank 3,
The other end 8 of the aluminum pipe 6 on the flange 5 side is joined so as to communicate with the pipe fitting hole 4 of the flange 5.

Next, a method of joining the surge tank 3 and the aluminum pipe 6 will be described. Since the method of joining the flange 5 and the aluminum pipe 6 is the same as the method of joining the surge tank 3 and the aluminum pipe 6, the description thereof is omitted.

As shown in FIG. 2, an adhesive 10 made of an epoxy thermosetting resin (viscosity: 1,000,000 to 2,000,000 cp) is cylindrically applied to the outer peripheral surface 9 of the aluminum pipe 6 using an air dispenser. Then, the aluminum pipe 6 is inserted into the pipe fitting hole 2 of the surge tank 3. In addition, surge tank 3
The pipe fitting hole 2 is a round hole having an inner diameter of 40 mm, and is formed to have a clearance 11 of 2 mm on one side when the aluminum pipe 6 having an outer diameter of 36 mm is inserted. Further, a chamfered portion 12 is formed at the upper end corner of the pipe fitting hole 2, and a chamfered portion 13 is also formed on the outer periphery of the tip of the aluminum pipe 6.

After arranging the aluminum pipe 6 at a predetermined position in the pipe fitting hole 2, the expander of a not shown expander is inserted into the aluminum pipe 6 from the tip side of the aluminum pipe 6 inserted in the pipe fitting hole 2. The aluminum pipe 6 is inserted, and the aluminum pipe 6 is expanded by the expander to expand the aluminum pipe 6. A plurality of locations on the outer peripheral surface 9 of the expanded aluminum pipe 6 are crimped onto the wall surface 14 of the pipe fitting hole 2, and as shown in FIG.
Is formed to be 0.01 mm to 0.05 mm. On this occasion,
The adhesive 10 applied to the outer peripheral surface 9 of the aluminum pipe 6 is
The outer peripheral surface 9 does not exist or almost does not exist in the portion crimped to the wall surface 14, but the clearance 1 formed between the non-crimped pipe outer peripheral surface portion 9a and the wall surface 14
In No. 1, the adhesive 10 is formed in a thin film shape over almost the entire area.
The outer peripheral surface 9 of the aluminum pipe 6 is filled with
The adhesive 10 extruded from between the wall surface 14 and the wall 14 is housed in the chamfered portion 13 formed at the tip of the aluminum pipe 6 and the chamfered portion 12 formed at the upper end corner of the pipe fitting hole 2.

The expansion of the aluminum pipe 6 inserted into the pipe fitting hole 2 is completed, and the adhesive 10 is filled between the outer peripheral surface portion 9a of the uncompressed pipe and the wall surface 14 to mount the aluminum pipe 6 in the surge tank 3. After assembling and similarly assembling the aluminum pipe 6 to the flange 5, install the intake manifold 1
The adhesive is heated and hardened by holding it in a heating furnace at 80 ° C. for 20 minutes to complete the joining of the surge tank 3 and the aluminum pipe 6 and the joining of the flange 5 and the aluminum pipe 6.

Although the adhesive 10 is applied to the outer peripheral surface 9 of the aluminum pipe 6 in the present embodiment, the adhesive 10 may be applied to the wall surface 14 of the surge tank 3 or the outer peripheral surface 9 of the surge tank 3.
Alternatively, it may be applied to both surfaces of the wall surface 14. Also, the adhesive 1
0 is not necessarily applied in a cylindrical shape, and may be applied in a spotted or striped shape on the outer peripheral surface 9 and / or the wall surface 14. Furthermore, the adhesive 10 does not have to be a thermosetting resin, and may be a two-liquid mixing type room temperature curable resin such as a urethane resin.

[0012]

According to the present invention, the outer peripheral surface of the pipe and the wall surface of the pipe fitting hole are joined by pressure bonding and adhesion. At this time, if the adhesive is filled in a clearance of 0.01 to 0.05 mm between the outer peripheral surface portion of the uncompressed pipe and the wall surface, the required amount of the adhesive is reduced and the material cost can be reduced. When crimping multiple points on the outer peripheral surface of the pipe to the pipe fitting hole, the unpressed outer peripheral surface of the pipe and the wall surface of the pipe fitting hole are arranged coaxially, so there is axial misalignment between the pipe and the pipe fitting hole. Does not occur and the accuracy of assembly is improved. further,
When inserting the pipe into the fitting hole, a large clearance can be secured, which facilitates the insertion work.
Since the dimensional accuracy of the fitting hole can be roughly set, the processing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an intake manifold used in an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a joint portion before joining pipes.

FIG. 3 is a cross-sectional view of a joint after the pipes are joined.

[Explanation of symbols]

 2 Pipe fitting hole 6 Aluminum pipe 9 Outer peripheral surface 9a Pipe outer peripheral surface 10 Adhesive 11 Clearance 14 Wall surface

Claims (4)

[Claims] 1. The pipe is inserted into a pipe fitting hole having an inner diameter capable of maintaining a predetermined clearance between the pipe and the pipe to be joined, and an adhesive is filled in the clearance between the pipe and the pipe fitting hole. In the method of joining pipes for fixing the pipe in the pipe fitting hole, the adhesive is applied to at least one of the outer peripheral surface of the pipe and the wall surface of the pipe fitting hole, and then the pipe is fixed to the pipe. The pipe is inserted into the fitting hole, the insertion portion of the pipe into the pipe fitting hole is expanded to crimp a plurality of locations on the outer peripheral surface of the pipe to the wall surface, and the outer peripheral surface portion of the uncompressed pipe and the wall surface are A pipe arranged coaxially, wherein the adhesive is filled in the clearance between the uncompressed outer peripheral surface of the pipe and the wall surface to bond the uncompressed outer peripheral surface of the pipe to the wall surface. Joining method. 2. The pipe joining method according to claim 1, wherein the clearance between the uncompressed outer peripheral surface of the pipe and the wall surface is 0.01 to 0.05 mm. 3. The pipe joining method according to claim 1, wherein the adhesive is applied to at least one of the outer peripheral surface and the wall surface of the pipe in a cylindrical shape. 4. The thermosetting resin adhesive is used as the adhesive, and the unbonded outer peripheral surface of the pipe and the wall surface are adhered by the thermosetting resin adhesive, and then the thermosetting resin adhesive is used. The method for joining pipes according to claim 1, wherein the agent is heat-cured.