JPH09196278A - Method for sealing end part of metal pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a sealing part for preventing the leakage of a fluid without performing welding at minimum costs so as to have a good durability against a high pressure in a system for sealing a pipe end part. SOLUTION: A method for sealing the end part 12 of a metal pipe 10 is provided with a step of applying the force of a substantially radial direction to the outer surface of the pipe 10 in the vicinity of the end part 12 to be sealed. A zone for the application of a force is continuously moved in both of circumferential and radial directions with respect to the pipe 10 so as to progressively produce the deformation of an inner direction in the side wall of the pipe 10 until the end part 123 is completely sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of closing an end of a metal pipe so as to prevent fluid from leaking.

The method according to the invention is used in particular in the field of production of heat exchangers for vehicles, and more precisely for the production of condensation distributors. The condensing distributor is typically made from extruded or drawn pipe and may have been inserted and sectioned to distribute the flow, but one or both ends of the pipe must be fluid tightly closed. I won't. However, the present invention is not limited to this particular field and may be used wherever it is necessary to block at the ends of metal pipes to prevent fluid leakage.

[0003]

2. Description of the Related Art The ends of pipes are made of copper and / or aluminum, or other metallic materials,
Welded covers are commonly used in applications where they must be occluded to prevent fluid leakage and the seal portion must withstand high pressures and temperatures.

[0004]

Welding operations are difficult to automate in the production process, often require re-welding and finishing operations, and are of considerable cost.

It is an object of the present invention to provide a system for closing pipe ends which creates a fluid tight closure without welding, the closure being formed at a minimum cost and good for high pressures. It is to provide a durable system.

[0006]

To achieve the above object, the present invention as set forth in claim 1, comprises the step of applying a substantially radial force to the outer surface of the pipe in the vicinity of the end to be closed. And wherein the area of application of force is circumferential and radial relative to the pipe so as to cause a gradual inward deformation of the side wall of the pipe until the end is completely closed. It is characterized by being continuously moved to both.

According to a second aspect of the present invention, in the method for closing the end of the metal pipe according to the first aspect, the force is freely rotated about an axis substantially parallel to the axis of the pipe. It is characterized by being added by a wheel that can.

According to a third aspect of the present invention, in the method for closing the end portion of the metal pipe according to the second aspect, the wheel and the pipe are moved in order to move the area for applying the force in the radial direction. , Movable relative to each other along a line substantially perpendicular to the axis of the pipe.

According to a fourth aspect of the present invention, in the method for closing the end portion of the metal pipe according to the first aspect, while the radial force is applied, the pipe has an area for applying the force. It is characterized in that it is rotated about its own longitudinal axis in order to change its position in the circumferential direction.

According to a fifth aspect of the present invention, in the method of closing the end of the metal pipe according to the second aspect, the pipe is held by a support, and the end to be closed is predetermined. It is characterized in that it protrudes from the support by an amount (A).

According to a sixth aspect of the present invention, in the method for closing an end portion of the metal pipe according to the fifth aspect, the wheel has an axial length of a portion of the pipe projecting from the support ( It is characterized in that it has a contact surface having a radius of curvature (R) which is equal to or longer than A).

According to a seventh aspect of the present invention, there is provided a method for closing an end portion of a metal pipe according to the fifth aspect, wherein the wheel is moving forward toward the axis of the pipe.
It is characterized in that the end to be closed has a flat surface which is substantially flush with the flat surface of the support which projects.

The invention according to claim 8 is the method for closing the end portion of the metal pipe according to claim 5, wherein the portion of the pipe projecting from the support and the diameter (D) of the pipe are The relationship between is substantially characterized by the following equation:

A = K + b D where A is the portion of the pipe protruding from the support in mm
The dimensions are in units, D is the diameter of the pipe in mm, K is a constant that can vary from 1.5 to 2.5, and b is from 0.15 to 0.25. Is a coefficient that can be changed to.

[0015]

Further characteristics and advantages of the invention are:
The following detailed description is given, purely by way of non-limiting example, in connection with the accompanying drawings. 1 and 2 are schematic side views showing two stages of the method of the present invention.

In FIG. 1, the metal pipe indicated by 10 is
It has an end 12 which is to be sealed by the method of the invention.

The tool required to occlude this end 12 comprises a tubular support 14 in which the pipe 10 is placed. The support 14 is constituted by, for example, an elastic bush so as to be inserted into the chuck 16.
The chuck 16 has an axis 18 which coincides with the longitudinal axis of the pipe 10.
You can rotate around. The support 14 has the primary purpose of preventing damage to the outer surface of the pipe 10 when grasped by the chuck 16. The support 14 has a flat surface 20 from which the part A of the pipe 10 projects.

The dimension A must be carefully determined in order for the method of the invention to be successful. Actually, the dimension A
If is too small compared to the diameter D of the pipe 10, the end cannot be closed. However, if dimension A
If is too large, excessive backflow and deformation of the material will occur. Experience has shown that the relationship between the dimension A and the diameter substantially follows the equation:

A = K + b D where A is the size in mm of a portion of the pipe projecting axially from the surface 20 of the support 14, and D is the diameter of the pipe 10 in mm. Yes, K is a constant,
Its value changes from 1.5 to 2.5, and b is a coefficient whose magnitude changes between 0.15 and 0.25.

For example, it has been empirically found that good results are achieved with the following relationships: A = 2 + 0.2D

During the operation for closing the end 12, the rotational speed of the pipe 10 around the axis of the pipe 10 varies from 600 to 1000 revolutions / minute. A typical value for the speed of rotation of the chuck 16 that gives good results is about 800 revolutions / minute.

The tool for closing the end of the pipe 10 is also a wheel 2 fixed to the tool holder 24 with no load.
2 is provided. This wheel 22 is the shaft 18 of the pipe 10.
It is free to rotate about an axis 26 that is parallel or substantially parallel to. The tool holder 24 is movable along a straight line perpendicular to the axis 18 of the pipe 10 and indicated by the arrow 28 in FIG.

The wheel 22 has a flat surface 30 that is substantially coplanar with the flat surface 20 of the support 14. Faces 30 and 2 are used to provide good qualitative results and to avoid trimming and deburring of the material during the closing operation.
The distance between 0 and the direction parallel to the axis 18 should be close to zero.

The surface of the wheel 22 intended to contact the wall of the pipe 10 has a curve 32 of radius R, which is preferably equal to the dimension A through which the closed end projects. Or big.

The unloaded wheel 22 represents an optimum tool for implementing the method according to the invention. However, the method can also be implemented with different types of tools. For example, a non-rotatable metal body having a contour similar to the cross section of the wheel 22 can be used instead of the wheel 22. The unloaded wheel 22 has the advantage of reducing the contact friction and heat generated during the deformation stage of the pipe 10 and gives better results from an aesthetic point of view. However, by giving up some of these benefits,
Non-rotatable tools can be used to carry out the method of the invention.

Starting from the arrangement shown in FIG. 1, the method according to the invention simply involves rotating the pipe 10 and moving the tool holder 24 in the direction of the arrow 28 towards the axis 18 of the pipe 10. Be implemented. The forward movement of the tool holder 24 is stopped when the joint between the arcuate surface 32 and the flat surface 30 is slightly beyond the axis 18.

FIG. 2 shows the arrangement of the tool and pipe 10 when the forward movement of the tool holder 24 is complete. Pipe 1
It can be noted that the protruding part of 0 is completely flattened and turned inside out. The upsetting of the material and the frictional heat generated during the process causes the material to undergo plastic deformation that completely seals the edges. During the forward movement of the tool holder 24, the wheel 22 applies an inward deformation force to the wall of the pipe 10, where the force is applied circumferentially as a result of the rotation of the pipe 10 and of the tool holder 24. It changes continuously in the radial direction as a result of the progress. The effect of the inward deformation is to gradually reduce the width of the hole and finally the hole is completely closed.

[0028]

The obstruction produced does not need to be welded again because it obstructs itself as a result of the frictional heat generated. The occlusion is particularly resistant to high operating pressures. The method of the invention can be easily automated,
It is very simple and minimal to implement compared to conventional welding methods.

[Brief description of drawings]

FIG. 1 is a side view showing a state before closing of an embodiment of a method for closing an end portion of a metal pipe of the present invention.

FIG. 2 is a side sectional view showing a state after the blockage according to the embodiment.

[Explanation of symbols]

10 ... Metal pipe, 12 ... End, 14 ... Support,
18, 26 ... Axis, 22 ... Wheel, 30 ... Flat surface, 32 ... Contact surface having radius of curvature (R).

Claims (8)

[Claims] 1. A step of applying a substantially radial force to the outer surface of the pipe (10) in the vicinity of the end (12) to be closed, until said end (12) is completely closed. The area of application of the force continuously moves both circumferentially and radially with respect to the pipe (10) so as to cause a gradual inward deformation of the side wall of the pipe (10). A method for closing an end of a metal pipe, which is characterized in that: 2. The method of closing an end of a metal pipe according to claim 1, wherein the force is an axis of the pipe (10).
A method of closing the end of a metal pipe, characterized in that it is applied by a wheel (22) which is free to rotate about an axis (26) substantially parallel to (18). 3. The method of closing an end of a metal pipe according to claim 2, wherein the wheel (22) and the pipe (1) are arranged to move the area of application of the force in a radial direction.
0) is a method for closing the ends of metal pipes, characterized in that they can be moved relative to each other along a line substantially perpendicular to the axis (18) of the pipe (10). 4. The method of closing an end of a metal pipe according to claim 1, wherein the pipe (10) is circular in position of the area of application of the force during the application of the radial force. Its own longitudinal axis to change in the circumferential direction
A method of closing an end of a metal pipe, which is rotated around (18). 5. The method for closing an end portion of a metal pipe according to claim 2, wherein the pipe (10) is a support (1).
4) to be occluded and held by said end (12)
A method for closing an end portion of a metal pipe, characterized in that a predetermined amount (A) is projected from the support (14). 6. The method of closing an end portion of a metal pipe according to claim 5, wherein the wheel (22) has an axial length of a portion of the pipe (10) protruding from the support (14). Contact surface with radius of curvature (R) longer than length (A)
(32) A method for closing the end of a metal pipe, which comprises (32). 7. The method of closing an end of a metal pipe according to claim 5, wherein the wheel (22) is moved forward while moving toward the shaft (18) of the pipe (10). Said support with protruding end (12) to be
A method for closing an end of a metal pipe, which has a flat surface (30) which is substantially flush with the flat surface (20) of (14). 8. The method of closing an end of a metal pipe according to claim 5, wherein the portion of the pipe (10) protruding from the support (14) and the diameter of the pipe (10).
A method for closing the end of a metal pipe, characterized in that the relationship with (D) substantially follows the following equation: A = K + b D where A is the pipe (1) protruding from the support (14)
0) is the size in mm, D is the pipe (1
0) is the diameter in mm and K is 1.5 to 2.5.
Is a constant that can be changed to, and b is a coefficient whose magnitude can be changed from 0.15 to 0.25.