JPH09310785A - Flexible pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give a function for absorbing a displacement in the direction of torsion without damaging flexibility in both of the pipe axial direction and the bending direction by continuously providing a bellow wall part to a pipe wall part having a circular cross section. SOLUTION: A metal pipe body 1 has a spiral or an annular bellow wall part 3 continuously provided to a circular pipe wall, and has a waved surface 5 in the peripheral surface of the pipe wall part 2 over the pipe axial direction. The waved surface 5 is formed so as to be projected outward or inward of a diameter of a raw pipe, and furthermore, projection is combined inward and outward. With this structure, width of a wave of the waved surface 5 is changed in the circumferential direction so as to give a function for absorbing displacement in the direction of torsion. The waved surface 5 is desirably formed in the peripheral surface of the pipe at plural positions and over the nearly full length thereof. A function for absorbing displacement in the direction of torsion can be given without damaging the flexibility in the pipe axial direction and the bending direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a flexible pipe made of a metal material, which is arranged in an automobile or various machines, equipments and the like in association with a demand for a flexible function.

[0002]

2. Description of the Related Art Conventionally, as a flexible pipe of this type, as shown in FIG. 6, a bellows wall portion (13) is connected to a circular pipe wall portion (12) at an appropriate position of the pipe body (11). In addition, it is configured with mounting flange walls (14, 14 ') and the like at both ends thereof.

[0003]

However, such a conventional flexible tube has a tubular body (11) having a bellows wall portion (13) connected to a circular pipe wall portion (12).
With this configuration, the flexible pipe exhibits flexibility in the original axial direction and bending direction of the flexible pipe, but there is almost no function for displacement in the twisting direction, and the bending shape The mounting flange wall (14) or / and (1
4 ') has a problem that cracks often occur on the tube body (11) side due to vibration or the like.

The present invention has been made in view of the above problems of the prior art, and has the function of absorbing the displacement in the twisting direction without impairing the flexibility in the pipe axis direction and the bending direction. It is an object of the present invention to provide a flexible pipe which can be effectively applied to eliminate unreasonable attachment at the time of installation and to eliminate the fear of cracks and breakage that may occur in the above-mentioned conventional techniques.

[0005]

In order to achieve the above-mentioned object, the present invention provides a tubular body in which a bellows wall portion is continuously provided so as to be continuous with a tubular wall portion having a circular cross section, and the circular shape formed by the wall body is formed. The purpose of the present invention is to provide a flexible pipe having a wave front on the pipe wall portion in the axial direction of the pipe, the wave front being formed substantially symmetrically at a plurality of portions of the peripheral surface, and having a circular shape. The pipe wall portion is formed over substantially the entire length, or the wavefront side formed by the circular pipe wall portion is formed as a separate body and fixedly connected to the bellows wall portion side.

Since the present invention is configured as described above,
The bellows wall portion can exert flexibility in the pipe axial direction and bending direction in the arranged state, and of course, by the wave front provided in the circular pipe wall portion formed by the wall body in the pipe axial direction. Even if it is displaced in the twisting direction, the absorbing function can be effectively given along with the free change of the width at the wavefront portion, and therefore the end mounting flange can be eliminated even under a vibrating state without forcibly mounting. It is possible to eliminate the fear of cracks and damage on the wall side near the wall,
In addition, due to the increase in surface area due to the wave front, for example, when it is used as an exhaust gas recirculation pipe for an automobile engine,
It is also possible to promote the heat dissipation effect of the high temperature fluid inside.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a flexible pipe of the present invention with a partial cutout, and FIG. FIG. 3 is a sectional view, FIG. 3 is a view corresponding to FIG. 1 above of another embodiment, FIG. 4 is a view corresponding to FIG. 1 above of another embodiment, and FIG. (1) is a pipe body made of a flexible metal material, which is connected to the circular pipe wall portion (2) and has a spiral or annular bellows wall portion (3) in place.
It has. A circular wave wall (2) formed by the tube body has a wave front (5) along the tube axis direction on the circumferential surface. The wave surface (5) may be formed so as to project outward from the diameter of the raw pipe as shown in FIG. 1, or may be formed so as to project inward as shown in FIG. It is also possible to combine outward and inward protrusions. By having such a wavefront (5), it is possible to change the width of the wave in the wavefront (5) in the circumferential direction to impart an absorbing function in the twisting direction.

As shown in FIG. 2, it is preferable to form the wave front at a plurality of symmetrical portions formed by the peripheral surface and over substantially the entire length thereof. (4, 4 ') are mounting flange walls at both ends.

Further, if desired, the wavefront (5) side formed by the pipe wall (2) is formed as a separate body and is continuously fixed to the bellows wall (3) side by brazing or the like (FIG. 4). The wavefront (5) may be formed in a spiral shape with a slight inclination with respect to the central axis of the tubular body (1) as shown in FIG. 5) The width is 5 to 10 times as long as one turn.

[0010]

As described above, the flexible pipe according to the present invention has the wave front (5) on the side of the circular pipe wall portion (2) formed by the pipe body (1). Without compromising the flexibility in the pipe axis direction and the bending direction, at the same time, the wavefront (5) can effectively give the absorbing function to the displacement in the twisting direction, and therefore, in the twisting direction at the time of arrangement. Even if the installation is violated in the installed state without undue installation, it is possible to eliminate the fear of cracks or breakage on the side of the pipe body (1) near the installation plunge wall (4, 4 '). Furthermore, since the surface area of the circular pipe wall is increased, the heat radiation amount can be increased when a high temperature fluid is flowed inside, and it can be effectively used for piping such as EGR and cooler. Extremely useful flexible tube A.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a flexible pipe according to an embodiment of the present invention with a partial cutout.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a view corresponding to FIG. 1 of the same as another embodiment.

FIG. 4 is a view corresponding to FIG. 1 of the above description of yet another embodiment.

FIG. 5 is a view corresponding to FIG. 1 of the above description of yet another embodiment.

FIG. 6 is a plan view of a flexible tube showing a conventional example.

[Explanation of symbols]

 1 Wall 2 Circular Pipe Wall 3 Bellows Wall 5 Wavefront

Claims (5)

[Claims] 1. A tube body comprising a bellows wall section continuously connected to a tube wall section having a circular cross section, wherein the tube axis is attached to the circular tube wall section (2) formed by the tube body (1). A flexible tube characterized in that it is constructed with a wavefront (5) extending in all directions. 2. The flexible pipe according to claim 1, wherein the wave front (5) is formed substantially symmetrically at a plurality of portions of the peripheral surface. 3. The wavefront (5) is formed into a circular pipe wall portion (2).
The flexible pipe according to claim 1, wherein the flexible pipe is formed over substantially the entire length of the flexible pipe. 4. The wavefront (5) side formed by the circular pipe wall portion (2) is formed as a separate body and is integrally fixed to the bellows wall portion (3) side. The flexible tube described in 1. 5. The flexible pipe according to claim 1, wherein the wave front (5) is provided in a spiral shape with a slight inclination with respect to the central axis of the pipe body (1).