JP3223150B2 - Pipe fitting and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting pipes through which gas, liquid and the like flow, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, brazing is performed by melting and adding a brazing material such as a metal having a lower melting point than a member to a gap formed between the members without melting the joints of the members. The gap formed between the joints greatly affects the joint strength and the like.

Here, conventionally, this brazing step is included.
As a method of manufacturing a pipe joint, for example, the following three manufacturing methods are known.

First, a first manufacturing method will be described with reference to FIG.

[0005] A fitting portion 4 is formed on an outer peripheral surface side of an opening 3 opened to the outer peripheral surface in communication with the flow passage 2 of the first tubular member 1, and a flow passage 6 of the second tubular member 5 is formed. The end of the second tubular member 5 has an outer diameter smaller than the inner diameter of the fitted portion 4 of the first tubular member 1. Form.

[0006] Then, the fitting portion 7 of the second tubular member 5 is loosely fitted to the fitted portion 4 of the first tubular member 1, and an opening communicating with the flow path 2 of the first tubular member 1 is formed. The center of the fitted part 4 and the axis of the fitting part 7 are positioned on the same line so that the flow path 3 of the second tubular member 5 and the flow path 6 of the second tubular member 5 concentrically coincide with each other. The wax is melted and added to a gap formed between the fitted portion 4 and the fitting portion 7 to fit the second tubular member 5 to the fitted portion 4 of the first tubular member 1. This is a method of fitting and fixing the portion 7.

Referring to FIG. 5, the second manufacturing method will be described. The outer diameter of the fitting portion 7a of the second tubular member 5 is smaller than that of the fitted portion 4 of the first tubular member 1. Formed to a size larger than the inner diameter. Then, the fitting portion of the second tubular member 5
7a is fitted into the fitting portion 4 of the first tubular member 1 by press-fitting, and a wax is melt-added into a narrow gap formed between the fitting portion 4 and the fitting portion 7a. This is a method in which the fitting portion 7a of the second tubular member 5 is fitted and fixed to the fitted portion 4 of the first tubular member 1.

Next, a third manufacturing method will be described with reference to FIG.

The outer diameter of the fitting portion 7 of the second tubular member 5 is smaller than the inner diameter of the fitted portion 4a of the first tubular member 1. In addition, near the fitted portion 4a,
Two caulking portions 8 are provided on a straight line including the center of 4a and at symmetrical positions from the center. This caulking part 8 is a caulking tool 9
By being swaged, the upper part of the fitted portion 4a is reduced in diameter inward.

[0010] The fitting portion of the first tubular member 1
After the fitting portion 7 of the second tubular member 5 is loosely fitted in 4a, the upper portion of the fitted portion 4a is deformed by caulking the two caulking portions 8 with a caulking tool 9, thereby forming the first tubular member. With the flow path 2 of the member 1 and the flow path 6 of the second tubular member 5 aligned with each other, the fitting portion 7 is positioned and fixed with respect to the fitted portion 4a. In this method, the wax is melted and added to the gap formed between the first tubular member 7 and the fitting portion 7 of the second tubular member 5 is fitted and fixed to the fitted portion 4a of the first tubular member 1. .

[0011] Conventionally, as a method of manufacturing a pipe joint,
For example, a metal material is heated to a certain temperature, pressure is applied to obtain a tubular forged material, and the obtained forged material is cut and then appropriately subjected to a grinding process, a finishing process, and the like. Are integrally formed with a first tubular portion 12 and a second tubular portion 13 orthogonal to one end of the first tubular portion 12, and the first tubular portion 12 and the second tubular portion 13 A method of forming flow paths 14 and 15 communicating with each other inside each is known.

[0012]

However, in the above-mentioned conventional manufacturing method in which the first tubular member 1 and the second tubular member 5 which are two separate members are brazed and fixed, the first and third tubular members are used. In the manufacturing method, since the positioning operation of the fitting portion 7 with respect to the fitted portions 4 and 4a is complicated, the gap formed between the fitted portions 4 and 4a and the fitting portion 7 is uniform over the entire circumference. The second tubular member 5
There is a problem that misalignment of the fitting portion 7 easily occurs. This misalignment not only hinders the smooth flow of the fluid in the flow paths 2 and 6, but also in places where the gap is wide, nests are formed in the wax added to the gap, causing leakage of the fluid, reduction in strength, etc. May be caused.

Further, in the second manufacturing method, since the positioning is performed by press-fitting, no misalignment of the fitting portion 7a occurs, but the gap formed between the fitted portion 4 and the fitting portion 6a is large. Since the molten solder is narrow and hard to flow, it may not be brazed over the entire circumference of the gap, which may lead to leakage of fluid, decrease in strength, and the like.

Further, when the first tubular member 1 is formed by processing of a drawn material, nests are formed at the center of the end face that closes the flow path 2 due to the strain generated inside the material at the time of drawing. Thus, there is also a problem that the leakage of the fluid, the decrease in the strength, and the like are caused.

In the above-mentioned conventional manufacturing method in which a member made of a single forged material is machined integrally, there is no problem of fluid leakage and reduction in strength. However, since machining by a processing machine is complicated, mechanical processing is difficult. It is difficult to automate the processing, and there is a problem in productivity. Further, forging machines are intended for small-scale mass production, and are not suitable for large-scale small-scale production.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a pipe joint which can tightly fit and firmly fit a fitting portion to a fitting portion, and has high productivity, and a method of manufacturing the same. The purpose is to:

[0017]

According to a first aspect of the present invention, there is provided a pipe joint communicating with a flow passage and having an opening formed on an outer peripheral surface and having a diameter larger than the opening concentrically with the opening. A first tubular member provided with a fitted portion to be fitted, and a flow passage communicating with an opening of the first tubular member having one end opened at an end face, the first tubular member being fitted to the first tubular member. A second tubular member as a fitting portion fitted and fixed to the portion, and an inner diameter of a fitting portion of the first tubular member on an outer peripheral surface of the fitting portion of the second tubular member. A knurl portion having a larger outer diameter is formed, and the fitting portion of the second tubular member is press-fitted into the fitted portion of the first tubular member and brazed and fixed.

The second tubular member is fitted with the second tubular member.
When the fitting portion of the tubular member is fitted and fixed, the knurled portion formed on the outer peripheral surface of the fitting portion positions the fitting portion of the second tubular member relative to the fitted portion of the first tubular member. Therefore, the fitting portion is not misaligned and fitted to the fitted portion. Further, the gap between the fitted portion of the first tubular member and the fitted portion of the second tubular member becomes uniform over the entire circumference, and is fixed by brazing uniformly over the entire circumference.

According to a second aspect of the present invention, in the first aspect, the first tubular member has one end face as an opening face of the flow path and the other end face as a closed face. A brazing layer is provided on the outer surface of the closed surface of the tubular member.

Further, since a brazing layer is provided on the outer surface of the other end surface of the first tubular member, even when the first tubular member is formed by processing a drawing material, the nest on the closed surface of the first tubular member is formed. The occurrence of is suppressed.

According to a third aspect of the present invention, there is provided a pipe joint manufacturing method comprising:
The tubular member is provided with an opening communicating with the flow path and opening on the outer peripheral surface, and a fitted portion formed concentrically with the opening and larger in diameter than the opening on the outer peripheral surface. One end of the second tubular member having an end face opened to the flow path communicating with the opening of the tubular member is a fitting portion fitted to the fitted portion of the first tubular member. A knurl portion having an outer diameter larger than the inner diameter of the fitting portion of the first tubular member is formed on the outer peripheral surface of the first tubular member, and the fitting portion of the second tubular member is fitted to the fitting portion of the first tubular member. And a step of brazing the fitting portion of the second tubular member fitted to the fitted portion of the first tubular member.

The positioning of the fitting portion of the second tubular member with respect to the fitting portion of the first tubular member is facilitated by the knurl portion, and the second tubular member is positioned with respect to the fitted portion of the first tubular member. The fitting portions of the tubular members are not aligned and fitted. Further, the gap between the fitted portion of the first tubular member and the fitted portion of the second tubular member becomes uniform over the entire circumference, and is fixed by brazing uniformly over the entire circumference.

According to a fourth aspect of the present invention, in the method for manufacturing a pipe joint according to the third aspect, the first tubular member has one end face as an opening face of the flow path and the other end face as a closed face. The step of providing a brazing layer on the outer surface of the closed surface.

Further, since a brazing layer is provided on the outer surface of the closed surface of the first tubular member, even when the first tubular member is formed by processing a drawing material, nests on the closed surface of the first tubular member are formed. The occurrence of is suppressed. The step of providing the brazing layer may be a step prior to the step of press-fitting the fitting portion of the second tubular member to the fitting portion of the first tubular member, or the fitting process of the first tubular member. The step of fixing the fitting portion of the second tubular member fitted to the portion by brazing may be performed simultaneously with or after this step.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an embodiment of a pipe joint according to the present invention will be described below with reference to FIGS.

In FIG. 3, reference numeral 21 denotes a first tubular member. The first tubular member 21 is formed into a substantially cylindrical shape by drawing, cutting, or the like of a metal material.

A substantially circular opening 22 is opened at one end surface of the first tubular member 21 and the other end surface is closed, and the opening portion is provided inside the first tubular member 21.
A flow path 23 is formed continuously from 22. Also, this channel
Reference numeral 23 extends along the axial direction of the first tubular member 21 to the vicinity of the other end face, and communicates with an opening 24 opened on the outer peripheral surface of the first tubular member 21.

One end surface of the first tubular member 21 is an opening surface of the flow path 23.
The other end surface of 21 is a closed surface, and on the outer surface of the closed surface, a brazing layer 26 such as a film-like copper brazing is provided.

As shown in FIG. 2, the outer peripheral surface of the first tubular member 21 near the other end is provided with the periphery of the opening 24 so as to be concentric with the opening 24. A circular fitting portion 25 having a larger diameter is formed.

On the other hand, in FIG. 3, reference numeral 31 denotes a second tubular member. The second tubular member 31 is formed into a substantially cylindrical shape having both open ends by drawing or cutting a metal material. The inside of the second tubular member 31 has the first
A flow path 33 concentrically communicating with the opening 24 of the tubular member 21 is formed along the axial direction.

Further, one end of the second tubular member 31 having the flow path 33 opened at the end face has an outer diameter of the first tubular member 21.
A cylindrical fitting portion 35 smaller than the inner diameter of the fitted portion 25 is formed. Further, a knurl portion 37 having an outer diameter larger than the inner diameter of the fitted portion 25 of the first tubular member 21 is formed on the entire outer peripheral surface of the fitting portion 35 at the central portion in the axial direction. The knurled portion 37 is formed of, for example, linear concave and convex strips provided by performing knurling over the entire circumference along the axial direction of the fitting portion 35.

The fitting portion 35 of the second tubular member 31
However, as shown in FIG. 1, it is fitted to the fitted portion 25 of the first tubular member 21 and fixed by brazing. That is, the braze 40 is uniformly spread, melted and added to the gap formed uniformly over the entire circumference between the fitted portion 25 and the fitting portion 35, and is fixed by brazing.

The braze 40 is a metal or an alloy having a lower melting point than the metal of the first tubular member 21 and the second tubular member 31, for example, a copper braze.

Next, a method of manufacturing the pipe joint according to the embodiment will be described.

First, the first tubular member 21 is obtained by obtaining a drawn material by drawing a metal material, and subjecting the drawn material to a cutting process, a grinding process, or the like, so that the flow path 23 and the opening 2 are formed.
4. The first tubular member 21 is manufactured by forming the fitted portion 25 and the like.

The second tubular member 31 is obtained by obtaining a drawn material by drawing a metal material and subjecting the drawn material to a cutting process, a grinding process, etc.
By forming 35 and the like, the second tubular member 31 is manufactured. At the time of this production, knurling is performed on the entire outer peripheral surface of the central portion in the axial direction of the fitting portion 35 of the second tubular member 31 to provide linear irregularities, thereby forming the first tubular member 31. A knurl portion 37 having an outer diameter larger than the inner diameter of the fitted portion 25 is formed.

Next, the fitting portion 35 of the second tubular member 31
Is fitted into the fitted portion 25 of the first tubular member 21 by press-fitting.

At the time of this fitting, the knurled part 37 formed on the outer peripheral surface of the fitting part 35 of the second tubular member 31 causes the first
The position of the fitting portion 35 of the second tubular member 31 with respect to the fitted portion 25 of the tubular member 21 is determined, and the center of the fitted portion 25 and the axis of the fitting portion 35 are located on the same line, First tubular member
The fitting portion 35 of the second tubular member 31 is not fitted to the fitted portion 25 of the 21 with a misalignment. Therefore, the opening 24 communicating with the flow path 33 of the second tubular member 31 and the flow path 23 of the first tubular member 21 is concentrically connected and connected.

Next, the first assembly assembled by this fitting
The first tubular member 21 and the second tubular member 31 are maintained at a predetermined temperature for a predetermined time by using a heating method selected in advance, and are brazed using, for example, a copper braze. The fitting portion 35 of the second tubular member 31 is fixed to the fitted portion 25.

That is, the fitting portion 25 of the first tubular member 21
The molten solder 40 is flowed into and added to the gap formed between the fitting portion 35 of the second tubular member 31 and
The fitting part 35 is fixed to the. At this time, the gap between the fitting portion 25 of the first tubular member 21 and the fitting portion 35 of the second tubular member 31 becomes uniform over the entire circumference, so that the molten braze 40 flows in uniformly over the entire circumference. And brazed evenly over the entire circumference. Since the knurled portion 37 is formed only at the central portion in the axial direction of the fitting portion 35, the molten wax 40 also flows into the gap between the distal end portion of the fitting portion 35 and the fitted portion 25. You.

A brazing layer 26 is provided on the outer surface of the closed surface of the first tubular member 21 by, for example, applying a brazing paste such as copper brazing and heating. This brazing layer
In the step of providing 26, the fitting portion 35 of the second tubular member 31
The fitting process 35 of the second tubular member 31 fitted to the fitted portion 25 of the first tubular member 21 or the pre-process of the process of press-fitting the fitted portion 25 of the tubular member 21 is performed. The step may be performed simultaneously with the step of fixing by attaching or after this step.

The brazing includes gas brazing, furnace brazing, high-frequency brazing, etc., depending on the heating method.
In the brazing, a portion to be fixed is subjected to chemical cleaning or the like, or an appropriate flux is applied.

The pipe joint manufactured as described above is used by connecting a pipe (not shown) to one end of the first tubular member 21 and the other end of the second tubular member 31, respectively.

As described above, according to the above embodiment,
Since the gap between the fitted portion 25 of the first tubular member 21 and the fitting portion 35 of the second tubular member 31 becomes uniform all around, the first tubular member
The misalignment of the fitting portion 35 of the second tubular member 31 with respect to the fitted portion 25 of 21 can be prevented, and the fitting portion 35 of the fitted portion 25 of the first tubular member 21 and the second tubular member 31 can be prevented. No nests are formed in the layered wax 40 melt-added in between. Therefore, this mated part
25 and the fitting portion 35 can be tightly fitted and fixed firmly to prevent leakage of fluid such as fuel and oil.

A first tubular member 21 and a second tubular member 31, both of which are formed from a drawn material and have relatively simple shapes, are formed.
Since it is manufactured using two separate members, compared with the conventional manufacturing method of processing one forged material into a complicated shape, cutting of the material becomes easier, so automation becomes possible, and productivity can be improved, Since the material is inexpensive, the production cost can be reduced, and moreover, it is possible to cope with various kinds of small-quantity production.

Furthermore, since the knurled portion 37 of the fitting portion 35 of the second tubular member 31 is formed only at the central portion in the axial direction of the fitting portion 35, the molten braze 40
It can smoothly flow into and add to the gap between the tip end of the member 35 and the fitted portion 25, and the strength can be further improved.

Further, since the brazing layer 26 is provided on the outer surface of the other end surface of the first tubular member 21, even when the first tubular member 21 is formed by a drawing material in which nests are easily generated, the first tubular member 21 can be formed. The occurrence of nests on the other end surface of the tubular member 21 can be suppressed,
Fluid leakage, reduction in strength, and the like can be more reliably prevented.

In the above-described embodiment, the knurled portion 37 of the fitting portion 35 of the second tubular member 31 is formed by a straight line provided along the axial direction over the entire outer peripheral surface at the center of the fitting portion 35. Although the configuration formed by the convex and concave ridges has been described, it can also be formed by the inclined concave and convex ridges inclining with respect to the axial direction.

Further, the knurled portion 37 of the fitting portion 35 of the second tubular member 31 is formed, for example, in such a shape that its diameter is enlarged toward the other end of the second tubular member 31, and the knurled portion 37 has a small diameter. In the case where a guide portion having an outer diameter smaller than the inner diameter of the fitted portion 25 of the first tubular member 21 is formed continuously at the distal end portion on the side, the fitting of the second tubular member 31 is performed. The press-fitting of the portion 35 to the fitted portion 25 can be facilitated.

[0050]

According to the first aspect of the present invention, since the gap between the fitted portion of the first tubular member and the fitted portion of the second tubular member becomes uniform all around the first tubular member. The misalignment of the fitting portion of the second tubular member with respect to the fitted portion of the member can be prevented, and a wax nest between the fitted portion of the first tubular member and the fitting portion of the second tubular member can be prevented. Can be tightly fitted and fixed without causing the occurrence of fluid leakage, and can be easily automated, improving productivity and reducing production costs.

According to the second aspect of the present invention, the brazing layer is provided on the outer surface of the closed surface of the first tubular member. The occurrence of nests on the closed surface of the tubular member can be suppressed,
Fluid leakage, reduction in strength, and the like can be more reliably prevented.

According to the third aspect of the present invention, the gap between the fitted portion of the first tubular member and the fitted portion of the second tubular member becomes uniform over the entire circumference. The misalignment of the fitting portion of the second tubular member with respect to the fitted portion can be prevented, and a cavity is formed between the fitted portion of the first tubular member and the fitting portion of the second tubular member. It is possible to tightly fit and fix the liquid tightly and prevent the fluid from leaking.

In addition, since it is manufactured by using two separate members, that is, a first tubular member and a second tubular member, both of which have relatively simple shapes, a conventional manufacturing method in which one forged material is processed into a complicated shape. As compared with the method, automation becomes easier, productivity can be improved, and production cost can be reduced.

According to the fourth aspect of the present invention, since the brazing layer is provided on the outer surface of the closed surface of the first tubular member, even if the first tubular member is formed by processing a drawing material, the first tubular member can be formed with the first brazing layer. The occurrence of nests on the closed surface of the tubular member can be suppressed,
Fluid leakage, reduction in strength, and the like can be more reliably prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a brazed state of an embodiment of a pipe joint of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1, showing a first tubular member and a second tubular member of the pipe joint.

FIG. 3 is a partially cutaway front view showing the same pipe joint.

FIG. 4 is a cross-sectional view showing a state where a conventional pipe joint is brazed.

FIG. 5 is a cross-sectional view showing a state in which another conventional pipe joint is brazed.

FIG. 6 is a cross-sectional view showing a state in which another conventional pipe joint is brazed.

FIG. 7 is a partially cutaway front view showing another conventional pipe joint.

[Explanation of symbols]

 21 First tubular member 23 Flow path 24 Opening 25 Part to be fitted 26 Brazing layer 31 Second tubular member 33 Flow path 35 Fitting part 37 Knurl part

Claims (4)

(57) [Claims] A first opening provided on the outer peripheral surface in communication with the flow path and a fitted portion formed concentrically with the opening and having a diameter larger than the opening on the outer peripheral surface; A tubular member, and a flow path communicating with the opening of the first tubular member, and one end of which is opened at the end face is a fitting portion fitted and fixed to the fitted portion of the first tubular member. A knurl portion having an outer diameter larger than the inner diameter of the fitted portion of the first tubular member is formed on the outer peripheral surface of the fitting portion of the second tubular member; A fitting according to claim 2, wherein the fitting portion of the second tubular member is press-fitted to the fitting portion of the first tubular member and brazed and fixed. 2. A method according to claim 1, wherein the first tubular member has one end face as an opening face of the flow path and the other end face as a closing face, and a brazing layer is provided on an outer surface of the closing face of the first tubular member. The pipe joint according to claim 1, wherein: 3. The first tubular member communicates with the flow path and has an opening formed on the outer peripheral surface and a fitted portion formed on the outer peripheral surface concentrically with the opening and having a diameter larger than the opening. And one end of a second tubular member having an end face opened to a flow path communicating with the opening of the first tubular member is fitted into the fitted portion of the first tubular member. A knurl portion having an outer diameter larger than the inner diameter of the fitted portion of the first tubular member is formed on the outer peripheral surface of the fitting portion as the fitting portion, and the fitting portion of the second tubular member is formed as the first tubular member. A step of press-fitting the fitting portion of the tubular member, and a step of brazing the fitting portion of the second tubular member fitted to the fitting portion of the first tubular member. A method for manufacturing a pipe joint, comprising: 4. The method according to claim 1, further comprising the step of providing a brazing layer on the outer surface of the closed surface of the first tubular member having one end surface as an opening surface of the flow path and the other end surface as a closed surface. 3
A method for producing the pipe joint according to the above.