KR20030076817A - Jointing method of press type pipe joint - Google Patents

Abstract

PURPOSE: A connecting method of compression-type pipe fittings is provided to prevent a pipe from coming out, improve the coupling force, and prevent a leakage of water and stress corrosion caused by buckling. CONSTITUTION: A pipe fitting comprises a pipe fitting body and a packing ring. A fixing protrusion(3) and a packing ring groove are formed on the inner surface of a coupling portion of the pipe fitting body one by one, and a stopper is formed to the innermost side. A pipe(7) is inserted into the coupling portion of the pipe fitting to more inside than the position of the packing ring. Compressing the outer periphery of the coupling portion, with a press-tool for compression, makes diametric plastic deformation. Thus, the diametric plastic deformation is made in the circumference of the contacting portion of the fixing protrusion and the pipe, and a contracted diametric uneven groove(8) is formed on the wall of the pipe. The packing ring is deformed by compression and is simultaneously adhered closely to the inner surface of the packing ring groove and the outer peripheral surface of the pipe. Thus, connection of the pipe and the pipe fitting is performed.

Description

How to connect crimp fittings {JOINTING METHOD OF PRESS TYPE PIPE JOINT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting crimped pipe fittings used for the connection of thin metal pipes such as copper pipes, low carbon steel pipes, and stainless steel pipes, and is particularly advantageous for soft metal pipe connections.

Conventional connection method, first of all, in case of copper pipe, welding method is mainly used. When welding pipes, it is difficult to keep the correct welding conditions such as proper heating temperature. There is a problem, and also requires a high skilled welder and welding equipment, there is a risk of fire due to the use of fire (fire) and there is a problem that takes a long time for welding connection.

In the case of thin stainless steel pipes (eg KSD 3595), their thickness is so thin that screw connection is impossible and the weldability in the field is not good.

The pipe fitting of FIG. 6 used in an example of the method (Japanese Patent Laid-Open No. 53-70072) is composed of a fitting fitting body 1 and a packing ring 5, and the fitting fitting body is the same as the insertion pipe 7. The tube 7 of the dimension is cut and the end thereof is expanded, and there is an annular packing ring groove 4 at the end of the fitting and an insertion portion 9 of constant length inward. After inserting the tube (7) completely for the connection, shrink the packing ring groove (4) in an annular shape with a crimping tool, and at the same time a part of the circumference of the insert (9) with the tube (7) without changing the circumferential length of the polygon (10) In this case, when the inserted length of the tube 7 is not longer than that of the polygon 10, since the polygon 10 is fastened to the inside of the packing ring 5, it is normal during operation. Sudden accidents in which the pipe (7) is pulled out of the fittings are often occurring.

In addition, the overlapping thin tube wall of the insertion portion 9 and the tube 7 are brought into contact with each other, so that the outer circumference is partially deformed without shrinking its circumference, so the fastening force is weak and the fastening force between the tube 7 and the pipe fitting is weak. When the relative rotational movement occurs, the fastening state is damaged and the fastening force is lost.

In addition, the thickness of the expanded pipe wall forming the packing ring groove 4 is very thin, which may cause water leakage due to buckling phenomenon in the circumferential portion of the crimping shaft diameter, which may cause leakage, and stress corrosion may occur. There is.

The present invention is to provide a new method for connecting a crimped fitting that replaces the welding connection method having the above-mentioned problems and solves the above problems of the polygon 10 crimping method.

1 is a partial cross-sectional view of the state in which the tube 7 is inserted into the fitting of the present invention.

2 is a partial cross-sectional view of a connection state between the pipe fitting and the pipe 7 of the present invention.

3 is a partial cross-sectional view of a connection state of a pipe 7 and a pipe fitting according to another embodiment of the present invention.

4 is a front view of the packing ring

5 is a cross-sectional view of the packing ring

Figure 6 is a cross-sectional view of the conventional polygonal 10 crimping fittings

7 is a cross-sectional view taken along line A-A of FIG.

Explanation of symbols on the main parts of the drawing

1: Fitting body 2: Fastening part

3: Hanging jaw 4: Packing ring groove

5: packing ring 6: stopper

7: tube 8: shaft diameter groove

9: inserting portion 10: polygon

The pipe fitting used in the crimping connection method of the present invention is composed of a metal fitting body 1 and an elastic packing ring 5, and an outer end thereof on the inner surface of the fastening portion 2 of the fitting body 1. In order to protrude in a circular shape from the inner surface to form a locking jaw (3) and a packing ring groove (4) for mounting the packing ring (5), which is pressed and fastened to the tube (7), the innermost insert of the tube (7) The stopper 6 having an inner diameter smaller than the outer diameter of the tube 7 may be integrally formed or separately manufactured so as to prevent the tip.

Corrosion, water leakage and the risk of fire can replace the welding connection method, there is an effect of solving the problem of the conventional polygonal crimp connection method.

That is, the locking jaw (3) fastened to the tube (7) is at the end of the fastening portion (2) and there is a packing ring (5) inside the locking jaw (3), the pipe more inward than the packing ring (5) It is confirmed in the hydraulic test whether the tip of (7) is inserted, so that the accidental dropping of the pipe (7) is prevented during the use of the piping system after construction, and the inner surface of the locking jaw (3) is circular, The shaft diameter recess groove (8) is made in the circumferential tube wall of the tube (7) in contact with the shaft (7), and the shaft diameter is plastically deformed and fastened together with the tube (7) so that the tightening force can be strengthened and the fastening portion (2) is cut, Since it can be formed by casting, rolling, rolling, etc., it is possible to arbitrarily select the appropriate thickness of the entire fastening portion 2 including the packing ring groove 4, thereby eliminating the buckling phenomenon at the time of the compression shaft diameter to prevent leakage and stress corrosion. The problem can be solved, and since the inner surface of the catching jaw 3 is circular, when relative rotation occurs between the tube 7 and the pipe fitting body 1, Also it is possible to solve the problems of the conventional crimp connecting method such as to maintain a clamping force as ever.

Claims (3)

In the method of connecting a crimped pipe fitting for circular metal pipe connection, which is composed of a metal fitting body 1 made of metal and a packing ring 5 of an elastic body, A locking projection (3) for protruding a circularly protruding inner diameter of a dimension larger than the outer diameter of the pipe (7) from the outer end of the fastening portion (2) of the pipe fitting body (1) to the inner side of the fastening portion (2); The packing ring (5) is packed in a fitting with a packing ring groove (4) for mounting and a fastening portion (2) formed with a stopper (6) having an inner diameter smaller than the outer diameter of the tube (7) at the inner end of the cap. After the ring 5 is mounted, the tube 7 is sufficiently inserted into the packing ring groove 4 position or more, and the outer peripheral surface of the fastening portion 2 is compressed and reduced in a circular shape to reduce the inner diameter of the locking jaw 3. The circumference of the wall of the pipe (7) in contact with the jaw (3) is axially plastically deformed together with the locking jaw (3) to form an annular shaft recess groove (8) on the wall (7) of the pipe (7) and the pipe fitting body ( 1) is strongly fastened to each other, and at the same time the packing ring 5 is also deformed by the shaft diameter of the fastening portion (2) at the same time on the inner surface of the packing ring groove 4 and the outer peripheral surface of the tube (7) A method of connecting a crimped pipe fitting, characterized in that the pipe 7 and the pipe fitting are connected to each other by being in close contact with each other to generate an airtight function. The method of claim 1, A method for connecting a crimp fitting, characterized in that the stopper (6) is manufactured separately from the fitting main body (1) and fixedly mounted in the fastening portion (2) by a mechanical method. The method of claim 1 It is characterized in that the inner diameter up to the inner end of the fastening portion 2 is made larger than the outer diameter of the pipe 7 without forming or mounting the stopper 6 on the fastening portion 2 of the fitting body 1. How to connect crimp fittings.