JP2001041373A - Expansion tube coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber-synthetic resin double tube structure expansion tube coupling which can fix the inner tube to the outer tube in a simple structure depending on no adhering method. SOLUTION: A coupling 1 consists of a rubber-synthetic resin, has a bending part 4 between its both ends, and it is furnished with an outer tube 2 which is fixed to a pair of fluid tubes 6 and 6' fitted to its both ends; and an inner tube 3 which is a straight tube form of member consisting of a rubber-synthetic resin, provided at the inner peripheral side of the outer tube 2, and its one side end 9 is fixed to one side end of the outer tube, while its other side end 10 is fitted to the inner peripheral side of the end part 6a' of the fluid tube 6' where the other side end of the outer tube is fixed. At one side end of the outer tube, a circular concave 8 for inner tube fitting is formed neighboring to the end edge 6b of the fluid tube, and at the one side end of the inner tube, a circular projection 9 fitting to the concave 8 for inner tube fitting of the outer tube, by projecting at the outer peripheral side is formed, while at the circular projection 9, a circular concave 12 for fluid tube end edge inserting which allows the insertion of the end edge part 6b of the fluid tube is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic pipe joint for a fluid pipe such as a drain pipe for viaducts, and more particularly to a telescopic pipe joint having a bellows structure and having a structure for preventing foreign matter from being retained.

[0002]

2. Description of the Related Art Conventionally, a bellows-structured joint having a wavy continuous bent portion has been used as a telescopic joint for a fluid pipe. In this bellows-structured joint, foreign substances such as sand and dirt stay in the groove on the inner surface at a flow rate of about the natural flow rate,
This results in reduced flow rates and flow rates.

In order to prevent such foreign matter from staying, a method of embedding a foam such as urethane foam into a groove on the inner surface of the joint is used. In this method, deformation of the groove of the joint is hindered by the foam. Therefore, there is a disadvantage that the joint cannot expand and contract sufficiently. So, as an alternative to this method,
2. Description of the Related Art An expansion / contraction pipe joint having a double pipe structure including a bellows-shaped outer cylinder and a straight inner tube having a smooth inner surface has been proposed and used. Since the inner pipe has a smooth inner surface, the double pipe structure can minimize the accumulated matter, and can maintain the function as an expansion pipe joint by expansion and contraction of the bellows-shaped outer cylinder.

[0004]

In a conventional double-tube type expansion joint made of a metal, the inner cylinder is fixed to the outer cylinder by welding or sandwiching the inner cylinder end by a pair of flanges. . Also, in the case of rubber and synthetic resin, welding is not possible, and the sandwiching method with a flange requires a lot of bolt tightening, which is troublesome, so fix the inner cylinder to the outer cylinder by bonding. I have.

When the inner tube is fixed to the outer tube by a bonding method in a rubber / synthetic resin-made double-pipe expansion joint, the bonding operation is poor in workability such as requiring a base treatment, and the bonding strength is low. There is a problem that an accident occurs in which the inner cylinder is detached from the outer cylinder because it cannot be obtained sufficiently.

The present invention has been made in view of the problems of the above-mentioned conventional rubber / synthetic resin-made double-pipe expansion joints. It is an object of the present invention to provide a novel rubber / synthetic resin double-tube-structure expansion / contraction pipe joint that can be firmly fixed to a pipe.

[0007]

The expansion joint according to the present invention, which solves the above-mentioned problems, is a bellows-like member made of rubber or synthetic resin and having at least one bent portion between both ends, and fitted to both ends. An outer cylinder fixed to opposed ends of a pair of fluid pipes to be connected, and a straight tubular member made of rubber and synthetic resin, which is disposed on the inner peripheral side of the outer cylinder, An end is fixed to one end of the outer cylinder, and the other end includes an inner cylinder fitted on the inner peripheral side of an end of a fluid pipe to which the other end of the outer cylinder is fixed. On the one end side of the outer cylinder, an annular inner cylinder fitting concave portion is formed adjacent to the edge of the fluid pipe to be fitted, and the one end of the inner cylinder has an outer peripheral portion. An annular projection is formed to protrude toward the inner side and fit into the inner cylinder fitting recess of the outer cylinder. The annular projection allows the insertion of the edge of the fluid pipe on the inner peripheral side thereof. Wherein the fluid tube edge insertion annular recess is formed that.

[0008]

According to the present invention, the annular projection of the inner cylinder is fitted into the inner cylinder fitting recess formed at one end of the outer cylinder, and a pair of fluid pipes to be connected to both ends of the outer cylinder. By fitting the opposite ends, the edge of one of the fluid pipes is inserted into the recess for inserting the edge of the fluid pipe of the inner cylinder to prevent the inner cylinder from being detached to the inner peripheral side, The annular projection is firmly fixed in the inner cylinder fitting recess of the outer cylinder. Therefore, the inner cylinder can be firmly fixed to the outer cylinder with an extremely simple configuration without the need for the bonding work and the troublesome work such as bolting at many places.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show an embodiment of an expansion joint according to the present invention. FIG. 1 is a partial sectional view of the joint, FIG. 2 is a partial sectional view showing an outer cylinder, and FIG. FIG.

The joint 1 has a double pipe structure comprising an outer cylinder 2 and an inner cylinder 3. The outer cylinder 2 is a cylindrical bellows-like member made of rubber or synthetic resin, and has a central portion formed as a bent portion 4 continuously formed in a wavy shape, and both ends thereof are fitted on the inner peripheral side thereof. A pair of fluid pipes 6 to be connected,
A fixing portion 5, which is fixed to the opposite ends 6a, 6a 'of 6',
5 '. On the inner peripheral side of the fixing portions 5, 5 'of the outer cylinder 2, as is apparent from FIG.
7 'is formed. In FIG. 1, the fixing portions 5, 5 'of the outer cylinder 2 are fixed to ends 6a, 6a' of the fluid pipes 6, 6 'by two hose clips 11, 11', respectively.

The fixed portion 5 on one end side of the outer cylinder 2 has an inner cylinder fitting concave portion 8 having a substantially rectangular cross section, which is adjacent to the edge 6b of the end portion 6a of the fluid pipe 6 to be fitted. Is formed.

The inner cylinder 3 is a straight cylindrical member having a smooth inner surface made of rubber and synthetic resin, and is disposed on the inner peripheral side of the outer cylinder 2.
One end 9 is formed as an annular projection projecting to the outer peripheral side and fitted into the inner cylinder fitting concave portion 8 of the outer cylinder 2, and the other end 10 is formed as an inner cylinder 3 adjacent to the annular projection 9. And is slidably fitted to the inner peripheral side of a fluid pipe 6 'fitted to the fixed portion 5' at the other end of the outer cylinder 2. The reason why the diameter of the end portion 10 of the inner cylinder 3 is made somewhat smaller is to facilitate the fitting into the fluid pipe 6 '.

The outer peripheral side of the annular projection 9 of the inner cylinder 3 is formed in a shape corresponding to the shape of the inner cylinder fitting recess 8 of the outer cylinder 2. The annular projection 9 has an annular inclined surface on the inner peripheral side that gradually increases in diameter toward the outside in the axial direction. The inclined surface allows the insertion of the edge of the fluid pipe. The concave portion 12 for inserting the end portion of the fluid pipe is formed. In FIG. 1, an annular inclined surface which gradually reduces its diameter toward the outside in the axial direction so as to conform to the shape of the concave portion 12 for inserting the edge portion of the fluid pipe into the inner tube 3 is formed at the edge 6 b of the fluid pipe 6. When the end 6 b of the fluid pipe 6 is inserted into the recess 12 for inserting the end of the fluid pipe of the inner cylinder 3,
The annular projection 9 of the inner cylinder 3 is prevented from being detached from the inner cylinder fitting recess 8 of the outer cylinder 2, and the annular projection 9 is firmly fixed in the inner cylinder fitting recess 8.

In order to construct the joint 1, the annular projection 9 of the inner cylinder 3 is fitted into the inner cylinder fitting recess 8 of the outer cylinder 2, and then the edge 6 b of the fluid pipe 6 is connected to the annular projection 9. Of the inner tube 3 so as to be fitted on the inner peripheral side of the end portion 6a 'of the fluid tube 6'. The fluid pipes 6, 6 'are fitted to the fixing parts 5, 5' of the cylinder 2, and the fixing parts 5, 5 'are fixed to the ends 6a, 6a' of the fluid pipes 6, 6 by the hose clips 11, 11 '. . In this construction step, no bonding or other troublesome work is required for fixing the inner cylinder 3 to the outer cylinder 2, and the joint can be constructed simply and quickly.

The concave portion for inserting the end portion of the fluid pipe of the annular projection 9 is not limited to the above-described shape. For example, as shown in FIG.
The concave portion 13 may have a rectangular cross section, and the edge portion 14 of the fluid pipe 6 may have a rectangular cross section that matches this.

When the fluid pipes 6 and 6 'are displaced in a direction approaching each other due to an earthquake or the like, the bent portion 4 of the outer cylinder 2 contracts, and the inner pipe 3 has the end 6a' of the fluid pipe 6 'as shown in FIG. When the inner tube 3 is squeezed from the surroundings by the fluid pipe 6 ′ by sliding to the middle left, the inner cylinder 3 is moved to the end 6 of the fluid pipe 6 ′.
As shown in FIG. 5, a slit 15 extending in the axial direction at a predetermined interval in the circumferential direction and the axial direction of the inner cylinder 3 may be formed so as to abut on a ′ and smoothly deform. As shown in FIG. 6, slits 16 extending in the axial direction at predetermined intervals in the circumferential direction may be formed. In FIG. 16, when the inner cylinder 3 is made of a hard material such as a synthetic resin, the slit 16 may be formed up to the edge as shown in the figure. However, when the inner cylinder 3 is made of a relatively soft material such as rubber, it is difficult to keep the shape. It is better to stop the slit 16 before reaching the edge.

[0018]

As described above, according to the present invention, the annular projection of the inner cylinder is fitted into the inner cylinder fitting recess formed at one end of the outer cylinder and connected to both ends of the outer cylinder. By fitting the opposite ends of a pair of fluid pipes as objects, the edge of one fluid pipe is inserted into the recess for inserting the edge of the fluid pipe of the inner cylinder, and the inner peripheral side of the inner cylinder is inserted. The annular projection of the inner cylinder is firmly fixed in the inner cylinder fitting recess of the outer cylinder. Therefore, the inner cylinder can be firmly fixed to the outer cylinder with an extremely simple configuration without the need for the bonding work and the troublesome work such as bolting at many places.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of an expansion joint according to the present invention.

FIG. 2 is a partial cross-sectional view showing the outer cylinder of the embodiment.

FIG. 3 is a partial cross-sectional view showing the inner cylinder of the embodiment.

FIG. 4 is a cross-sectional view showing another example of a concave portion for inserting an end portion of a fluid pipe.

FIG. 5 is a side view showing an example of an inner cylinder having a slit formed therein.

FIG. 6 is a side view showing another example of the inner cylinder in which a slit is formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Telescopic joint 2 Outer cylinder 3 Inner cylinder 4 Bending part 5, 5 'Fixed part 6, 6' Fluid pipe 8 Inner cylinder fitting concave part 9 Annular protrusion part 12 Fluid pipe end edge insertion concave part

Continued on front page F term (reference) 3H104 JA08 JB02 JC09 JD01 LB16 LB36 LB37 LG02 3J039 AA01 BB01 DA04 FA01 FA15 MA01 3J043 AA03 DA09 FA04 FB20 3J045 AA01 AA14 BA02 BA03 CB30 EA10

Claims (1)

[Claims] 1. A bellows-like member made of rubber or synthetic resin and having at least one bent portion between both ends, and opposed ends of a pair of fluid pipes to be connected to the both ends. And a straight tubular member made of rubber / synthetic resin, which is disposed on the inner peripheral side of the outer cylinder, one end is fixed to one end of the outer cylinder, and the other is The end includes an inner cylinder fitted on the inner peripheral side of the end of the fluid pipe to which the other end of the outer cylinder is fixed, and the fluid fitted on the one end of the outer cylinder. An annular inner cylinder fitting recess is formed adjacent to the end of the tube, and the one end of the inner cylinder protrudes outward and fits into the inner cylinder fitting recess of the outer cylinder. An annular projection is formed on the inner periphery of the annular projection. The annular projection has an annular fluid pipe edge insertion recess that allows insertion of the edge of the fluid pipe. And an expansion joint.