JPH0577534U - Flexible Tube - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a flexible tube mounted in the middle of an exhaust system of an automobile, and more particularly to a flexible tube formed of at least two metal tubes. ， Reducing the number of ventilation holes while satisfying the function of surely releasing air etc.
The purpose is to improve work efficiency. [Structure] At least one vent hole 7 is formed in the outermost metal tube 5 of the metal tubes 4, 5, and between the two metal tubes 4, 5 concentrically adjacent to each other,
By sandwiching the wire 8 over its entire length, air vent passages 9 communicating with the vent holes 7 were formed on both sides of the wire 8 between the two metallic tubes 4 and 5.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a flexible tube mounted in the middle of an exhaust system of an automobile, and more particularly to a flexible tube formed of at least two metal tubes.

[0002]

[Prior Art]

 The exhaust system of an automobile is suspended from the vehicle body, and the front exhaust pipe that forms part of the exhaust system is connected to the exhaust manifold of the engine. Therefore, the vibration of the engine is transmitted to the exhaust system, and the bending and displacement of the front exhaust pipe caused by the vibration are absorbed, so that a flexible pipe connecting device is required in the middle of the exhaust system.

As a characteristic of such a pipe connecting device, one having a small spring constant (one having a small rigidity) is required, and for example, a flexible tube made of at least two metal tubes is used for the pipe connecting device.

An example of such a flexible tube is disclosed in Japanese Utility Model Laid-Open No. 60-34517. FIG. 4 shows a flexible tube disclosed in Japanese Utility Model Laid-Open No. 60-34517, in which reference numeral 21 is a front exhaust pipe connected to an exhaust manifold (not shown) of an engine, and 22 is a vehicle body (FIG. It is a rear exhaust pipe suspended in (not shown). Reference numeral 23 is a flexible tube, and cylindrical portions 23A and 23B are formed at both ends thereof. One ends of the front exhaust pipe 21 and one end of the rear exhaust pipe 22 are fitted into the cylindrical portions 23A and 23B, respectively, and the cylindrical portion 23A of the flexible tube 23 and one end of the front exhaust pipe 21 are welded to each other. The cylindrical portion 23B of the flexible tube 23 and one end of the rear exhaust pipe 22 are welded by welding.

The flexible tube 23 is formed by stacking two metallic inner layer tubes 24 and two metallic outer tube tubes 25 concentrically and disc-shaped in a direction orthogonal to the axial direction of the metallic tubes 24, 25. A plurality of mountain portions including the overhanging portions 26 are formed to have a bellows shape. Valleys 27 are alternately formed between the peaks formed by the overhangs 26.

Further, ventilation holes 28 are formed in the peaks and valleys 27 formed by the cylindrical portions 23 A and 23 B and the overhanging portions 26 on both sides of the metallic outer layer tube 25. However, the dew condensation, the water vapor contained in the metal tubes 24 and 25 due to the vaporization of the water trapped during the hydraulic bulge molding, the air and oil present between the metal tubes 24 and 25, etc. , Is guided to one of the vent holes 28 and is discharged to the outside from the vent holes 28. This prevents the expansion of the gas between the metal tubes 24 and 25, and prevents the deformation of the flexible tube 23 and the problem of increased rigidity.

[0007]

[Problems to be solved by the device]

 However, in the conventional flexible tube 23, water vapor, air, and the like between the metal tubes 24 and 25 are discharged to the outside, so that the overhang portions 26 and the valley portions 27 of the metal outer layer tube 25 are Vent holes 28 are provided respectively. The vent hole 28 is provided after the hydraulic bulge molding, and the metal inner layer tube 24 having a small plate thickness (about 0.3 mm) is not provided with holes. In addition, there is a problem that the work efficiency is poor because it is a minute work that requires careful operation for forming the vent hole 28 only in the metal outer layer tube 25 having a thin plate thickness (about 0.3 mm).

If the number of vent holes 28 is small, water vapor, air, etc. near the vent holes 28 are released, but water vapor, air, etc., in the part far from the vent holes 28 are between the metal tubes 24, 25. The flexible tube 23 is deformed by the expansion pressure of the enclosed water vapor, air, etc., or the rigidity is increased, and the function of the flexible tube 23 cannot be sufficiently fulfilled.

The present invention has been made to solve the above-mentioned problems, and its purpose is to reduce the number of ventilation holes while satisfying the function of reliably releasing water vapor, air, etc. between metal tubes. It is to provide a flexible tube that can be reduced in number and improve work efficiency.

[0010]

[Means for Solving the Problems]

 The present invention provides a flexible tube in which at least two metal tubes are concentrically laminated and a plurality of disc-shaped projecting portions are formed in a direction orthogonal to the axial direction of the tube. By forming at least one vent hole in the outermost metal tube of the metal tubes and sandwiching the wire between two concentrically adjacent metal tubes over their entire length. An air vent passage communicating with the air vent is formed on both sides of the wire between the two metal tubes.

[0011]

[Action]

 In the present invention, water vapor, air, and the like between the two concentrically adjacent metal tubes are guided to the vent hole through the vent passage, and discharged to the outside from the vent hole.

Therefore, the flexible tube is prevented from being deformed by the expansion pressure of water vapor or the like between the two metal tubes, and the rigidity is lowered.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a flexible tube according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 1 is a front exhaust pipe connected to an exhaust manifold (not shown) of the engine, and 2 is a rear exhaust pipe suspended from a vehicle body (not shown). 3 is a flexible tube, and cylindrical portions 3A and 3B are formed at both ends thereof. One end of the front exhaust pipe 1 and one end of the rear exhaust pipe 2 are fitted into the cylindrical portions 3A and 3B, respectively, and the cylindrical portion 3A of the flexible tube 3 and one end of the front exhaust pipe 1 are welded by welding. There is. The cylindrical portion 3B of the flexible tube 3 and one end of the rear exhaust pipe 2 are welded by welding.

The flexible tube 3 is formed by laminating two metal inner layer tubes 4 and metal outer layer tubes 5 concentrically, and forming a disc shape in a direction orthogonal to the axial direction of the metal tubes 4, 5. A plurality of mountain portions including the overhanging portions 6 are formed to have a bellows shape. Valleys 6 </ b> A are alternately formed between the peaks formed by the overhang portions 6.

A vent hole 7 is formed in the cylindrical portion 3 A of the metallic outer layer tube 5. By sandwiching the wire 8 in a straight line along the axial direction between the metal inner layer tube 4 and the metal outer layer tube 5, the wire 8 between the two metal tubes 4 and 5 is formed. Vent passages 9 communicating with the vent holes 7 are formed on both sides of the vent hole 7. Both ends of the wire 8 reach the cylindrical portions 3A and 3B of the flexible tube 3.

As shown in FIG. 3, the wire 8 is linearly sandwiched between the inner layer tube material 4A and the outer layer tube material 5A and is hydraulically bulged to form the flexible layer shown in FIGS. The tube 3 is made.

Water vapor, air and the like between the two concentrically adjacent metal tubes 4 and 5 are guided to the vent hole 7 through the vent passage 9 and discharged from the vent hole 7 to the outside. Be done.

Therefore, the flexible tube 3 is prevented from being deformed by the expansion pressure of steam, air, etc. between the two metal tubes 4 and 5, the rigidity is lowered, and the function of the flexible tube 3 is sufficiently fulfilled. .

According to the above-described structure, the wire 8 is sandwiched between the two metal tubes 4 and 5 to form the vent passage 9, and the vent hole 7 communicating with the vent passage 9 is used to remove water. Since it has a structure that discharges steam, air, etc., it has the function of discharging the water vapor and air trapped between the two metal tubes from many conventional vents, while maintaining the same number of conventional vents. It is possible to improve the work efficiency by reducing the work load and reducing the work amount of the fine operation for creating the ventilation holes.

Further, as the number of ventilation holes decreases, stress concentration around the ventilation holes of the metal outer layer tube 5 can be alleviated. In the present embodiment, the vent hole 7 is formed in the cylindrical portion 3A of the metallic outer layer tube 5, but the vent hole communicating with the vent hole 9 is the protruding portion of the other metallic outer layer tube 5. Other locations such as 6 may be used, and the number of vent holes communicating with the vent holes 9 may be two or more.

Further, in the present embodiment, the wire 8 has a linear shape, and the wire 8 is provided between the metal inner layer tube 4 and the metal outer layer tube 5 along the axial direction over the entire length. Although the wire is sandwiched, the manner of sandwiching the wire is not limited to a linear shape, and may be twisted in the axial direction, for example, and may be spiral.

Further, in this embodiment, the flexible tube is made up of the metal tube having two layers, but the flexible tube can be applied to the flexible tube having three or more layers of metal tube. .

[0024]

[Effect of the device]

 As described above, according to the present invention, a wire is sandwiched between two metal tubes to form an air vent passage, and water vapor or the like is discharged from a vent hole communicating with the air vent passage. Therefore, while satisfying the function of releasing water vapor, air, etc., trapped between the two metal tubes from each conventional ventilation hole, the number of conventional ventilation holes is reduced and the ventilation holes are made accordingly. This has the effect of reducing the amount of work required for various operations and improving work efficiency.

[Brief description of drawings]

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

FIG. 2 is a transverse sectional view of the flexible tube.

FIG. 3 is a perspective view showing a state of the flexible tube before being molded.

FIG. 4 is a partial vertical cross-sectional view of a conventional flexible tube.

[Explanation of symbols]

 3 Flexible tube 4 Metal inner layer tube 5 Metal outer layer tube 6 Overhanging part 7 Vent hole 8 Wire 9 Vent passage

Claims (1)

[Scope of utility model registration request] 1. At least two metal tubes (4,
A flexible tube formed by stacking 5) in a concentric shape and forming a plurality of disc-shaped projecting portions (6) in a direction orthogonal to the axial direction of the tubes (4, 5), wherein the metallic tube At least one vent hole (7) is formed in the outermost metal tube (5) of (4,5), and between the two metal tubes (4, 5) concentrically adjacent to each other, By sandwiching the wire (8) over the entire length thereof, the air vent passage (7) communicating with the ventilation hole (7) is provided on both sides of the wire (8) between the two metal tubes (4,5). 9) A flexible tube characterized by being formed.