JPS6357988A - Method of connecting piping and flange - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for connecting piping and a flange used, for example, in a refrigerant circuit of a car air conditioner.

(Prior Art) Piping for a refrigerant circuit in a car air conditioner is connected to a compressor or the like via a flange, so that refrigerant can circulate within the piping and each device.

As shown in Fig. 2 (A) to (C), there are various types of piping 1 and flange 2, but in the case of conventional products, after fitting the two, welding or brazing (a-C )
It is connected with. The end of the pipe 1 to which the flange 2 is joined is inserted into the opening 5 of the compressor 4 via the O-ring 3, and then fixed with bolts (not shown).

(Problems to be Solved by the Invention) However, in the conventional connection method, the airtightness of the welded part must be inspected each time, and when aluminum material is used for eaves eaves as in recent years, The base material softens due to thermal effects, causing a decrease in strength.

Furthermore, in the case of aluminum brazing, it is necessary to perform surface treatment to prevent corrosion.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and its object is to provide a method for connecting piping and a flange that is easy to work with and can be firmly integrated.

(Means for solving the problem) In order to achieve the above object, the connection method of the first invention includes forming a hole in the flange that is slightly larger than the outer diameter of the end of the pipe, and inserting the end of the pipe into the hole. The tip is made to protrude from the flange, and a molded core having a diameter slightly larger than the inner diameter of the pipe is press-fitted into the open end of the pipe to expand the end of the pipe.

Further, in the second invention, a groove is provided along the axial direction on the inner surface of the hole of the flange, and then the pipe is fitted and expanded.

(Function) With the first configuration, the end of the pipe expands in the radial direction in the molded core and comes into pressure contact with the hole in the flange, and the tip of the pipe that protrudes from the flange further expands in the radial direction, so it is loaded in the axial direction. Even if it acts, it will not come off.

With the second configuration, the expanded excess wall of the pipe enters the groove formed in the hole of the flange, thereby preventing relative rotation between the pipe and the flange.

(Example) FIG. 1 shows a car air conditioner pipe 10 and a flange 11 connected according to the first invention.
The end portion is expanded and fitted into the hole 12 of the flange 11 in a press-contact state. Further, the protruding end 13 of the pipe 10 expands further and is locked to the lower end of the hole 12, so that the pipe 10 does not come off from the flange 11.

A sealing O-ring 14 is fitted around the protruding end 13 of the pipe 10, and in this state it is connected to the connection port 16 of the compressor 15. Bolt insertion holes 17 are provided in the flange 11.
A screw hole 18 is formed on the compressor 15 side, and both are screwed together with bolts (not shown).

Next, the process of connecting the pipe 10 and the flange 11 is shown in FIGS. 3 and 4.

First, a hole 12 slightly larger than the outer diameter of the pipe 10 and a bolt insertion hole 17 are formed in the flange 11.

Next, fix the pipe 10 with a chuck or the like with the open end facing upward (in the opposite direction to that shown in Fig. 1), and then attach the flange 12 to the pipe 1.
0, and the periphery of the flange is supported by a jig 19.

Subsequently, a molded core 20 having an outer diameter slightly larger than the inner diameter of the pipe 10 is press-fitted into the open end of the pipe 10 using a press or the like. Through this process, the pipe 10 expands in the radial direction and becomes integrated with the flange 11, as shown by the arrow in FIG. Stop. All that is left to do is to handle the molded core 20 from the piping 10.

As shown in FIG. 1, the inner diameter of the pipe 10 after expansion is measured. , if the wall thickness is t and the inner diameter of the flange hole 12 is D, then the pipe 10
The condition for connecting the flange 11 and the flange 11 is Do+2t>D. Here it is. It is desirable that +21 is sufficiently small for D to the extent that it satisfies the connection function; for example,
It is sufficient to make it larger than D by about 0.51 nll.

Further, by locking the protruding end 13 of the pipe 10 to the flange hole 12, the pipe 10 will not come off from the flange 11 even if high-pressure refrigerant flows into the pipe 10 from the compressor 15 and a pulling force is applied. .

As shown in FIG. 5, when the outer diameter of the pipe 10 is larger than the inner diameter of the hole of the flange 11, the above-mentioned processing is performed after forming the drawn portion 21 by drawing the end of the pipe.

Furthermore, as shown in FIG. 6, if the outer diameter of the pipe 10 is considerably smaller than the hole 12 of the flange 11, the pipe end is swaged to form an enlarged pipe portion 22 before the above-mentioned processing is performed. .

In the embodiments of FIGS. 5 and 6, the O-ring 14 of the projecting end 13 of the pipe 10. Similarly, it is fitted and bolted to the compressor 15 side.

FIG. 7 shows a cross-sectional view of the pipe 10 and flange 11 connected according to the second invention.

In this figure, there are a plurality of grooves 2 in the axial direction on the inner surface of the flange hole 12.
3 is formed. Therefore, when the pipe 10 is inserted into the hole 12 of the flange and the end of the pipe is expanded by the molded core 20 (FIG. 3), the excess wall on the outer surface slightly enters the trapezoid 23 and the pipe 1o is inserted into the hole 12. rotation is prevented. That is, with the configuration of the second invention, the piping 10 is prevented from both pulling out and rotating with respect to the flange 11, and is more firmly connected to the flange 11.

FIG. 8 shows an embodiment in which the present invention is applied to the piping shown in FIG. 25 is fitted. The flange hole 12 is shaped to receive the bead portion 24 and the O-ring 25, compress the O-ring 25, and seal the pipe 10 and the flange 11.

In this state, if the pipe is expanded using the molded core 20 in the same manner as shown in FIGS. 3 and 4, the pipe 10 and the flange 11 will be connected.
O-ring 25 is also compressed to completely seal the connection. When connecting the pipe 10 to the compressor 15, another O-ring 14 is interposed between the flange 11 and the compressor 15 and bolted.

(Effects of the Invention) As explained above, in the first invention, a hole slightly larger than the outer diameter of the end of the pipe is formed in the flange, the end of the pipe is inserted into the hole, and the tip thereof protrudes from the flange. Since the molded core having a diameter slightly larger than the inner diameter of the pipe is press-fitted from the open end of the pipe and expanded, a flanged pipe that is strong and completely free from heat effects can be obtained. Surface treatment and airtightness inspection before and after processing are no longer required.

Further, in the second invention, since a groove is formed along the axial direction on the inner surface of the flange hole, and then the pipe is fitted and the well is expanded, the mutual rotation of the pipe and the flange is prevented. This has the effect of making the two more firmly connected.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the pipe and flange connected according to the first invention, Figs. 2 (A) to (C) are longitudinal sectional views of conventional products, and Figs. 3 and 4 are longitudinal sectional views of the piping and flange connected according to the first invention. FIG. 5 and FIG. 6 are longitudinal cross-sectional views showing flanges connected to pipes of different shapes, and FIG. 7 is a cross-sectional view of the pipes and flanges connected according to the second invention. FIG. 8 is a longitudinal cross-sectional view showing an example of connecting the pipe and the flange in a case where the O-ring that seals the compressor and the flange is not close to the protruding end of the pipe. DESCRIPTION OF SYMBOLS 10... Piping, 11... Flange, 12... Hole of flange, 13... Projecting end of piping, 20... Molding core, 23... Groove.

Claims (2)

[Claims] (1) A hole slightly larger than the outside diameter of the pipe end is formed in the flange, and the end of the pipe is inserted into this hole so that the tip of the pipe protrudes from the flange, forming a hole that has a diameter slightly larger than the inside diameter of the pipe. A method for connecting piping and a flange, characterized by press-fitting a core into the open end of the piping and expanding the end of the piping. (2) A hole slightly larger than the outside diameter of the end of the pipe is formed in the flange, a groove is provided along the axial direction on the inner surface of the hole, and the end of the pipe is inserted into the hole so that the tip of the pipe protrudes from the flange. 1. A method for connecting a pipe and a flange, the method comprising: expanding the end of the pipe by press-fitting a molded core having a diameter slightly larger than the inner diameter of the pipe into the open end of the pipe.