JPH102473A - Flexible pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the penetration of a foreign matter, by arranging at the opening end of a spigot pipe, a dust seal which is elastically deformed by being followed after the displacement of a sleeve, and always brought into pressure contact with the inner surface of the sleeve. SOLUTION: The base end of a funnel shaped dust seal 6 whose projected end is gradually enlarged taperingly, is fixed on the inner circumferential surface of the opposed end of a pair of right and left spigot pipes 1 having a flange 1a at its outward end. This dust seal 6 is formed of rubber or synthetic resin having elasticity, and a V-shaped notch 7 directed to a pipe shaft direction is formed in a part in the circumferential direction of the enlarged part 6a of the dust seal 6. When the spigot pipes 1 are vertically displaced, and a large clearance is formed among the spigot pipes 1 and sleeves 2, the dust seal 6 is elastically deformed by being followed after the displacement of the enlarged part 6a of the dust seal 6, and always brought into pressure contact with the inner surfaces of the sleeves 2. Hereby, the clearance can be completely closed, and the penetration of a foreign matter can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint provided at a connection portion such as a fluid transport pipe, and more particularly to a flexible pipe joint having a dust seal.

[0002]

2. Description of the Related Art In order to prevent damage due to uneven settlement of soft ground or displacement of the ground due to an earthquake or the like, a fluid transport pipe buried underground is usually provided with a flexible portion at a connection portion between the fluid transport pipes. A pipe joint (which also has elasticity) is used.

FIG. 10 schematically shows an example of this type of pipe joint. A pair of left and right spigot pipes (small-diameter pipes) b each having a flange a at an end in the pipe axis direction, and their opposing portions are shown. And a sleeve (large-diameter pipe) C mounted via packing and a press ring (not shown).

When the water pipes connected to the left and right spigot pipes b are vertically displaced due to the settlement of the ground or the like, as shown in FIG. The bending load acting on the fluid transport pipe is absorbed.

However, such bending causes a relatively large gap d to be formed between the lower outer peripheral surface of one of the spigot tubes b and the inner peripheral surface of the sleeve C. Foreign matter such as sand and gravel can easily enter.

[0006] In this case, when trying to bend again in the opposite direction to the above, it becomes difficult to bend due to the resistance of the foreign matter, and the function as a flexible pipe joint is impaired.

As a method for solving this problem, a sponge, a hollow trapezoidal rubber or a rubber seal such as a chevron rubber is fixed to a position corresponding to the outer peripheral surface of the spigot tube b in the sleeve C, or the opposing ends of the spigot tube b are connected to each other. It is also conceivable to attach a bellows to the vehicle.

[0008]

In the sponge dust seal described above, since the restoring force is small, a non-seal portion occurs and the allowable bending angle of the pipe joint is reduced. Even in dust seals such as hollow trapezoidal rubber and angled rubber, unsealed portions are formed, the allowable bending angle is reduced, and the amount of protrusion in the inner diameter direction is slightly increased, so that the flow resistance of the fluid is increased.

Further, when the bellows is mounted, the sealing performance is improved, but the amount of protrusion in the inner diameter direction becomes large.
Distribution resistance increases.

The present invention has been made in view of the above problems, and has a dust seal provided at the open end of a spigot tube so as to be elastically deformed following the displacement of a sleeve and to always press against the inner surface of the sleeve. Accordingly, an object of the present invention is to provide a flexible pipe joint having a high effect of preventing foreign matter from entering.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a small-diameter pipe and a large-diameter pipe externally fitted with a required gap formed on an outer peripheral surface of an opening end thereof. And a flexible pipe joint in which a seal member is sealed in a gap between the small-diameter pipe and the large-diameter pipe, wherein at least a part of the small-diameter pipe in the circumferential direction is notched at an open end located in the large-diameter pipe. A radially elastically deformable dust seal having a portion is provided so that at least the outer peripheral edge thereof is always in contact with the inner surface of the large diameter pipe.

It is preferable that the notch has a V-shape whose front end is widened.

[0013] It is preferable that the notch portion overlaps when the dust seal is pressed against the large-diameter pipe.

[0014] It is preferable that the notch is formed large in the upper region of the circumference of the small-diameter pipe and the large-diameter pipe.

It is preferable that the notch is formed by providing an elastic ring at the end of the enlarged diameter portion of the dust seal.

According to the present invention, even if the small-diameter pipe and the large-diameter pipe are displaced in any direction and a large gap is formed in the lower portion between the outer peripheral surface and the inner peripheral surface, the large-diameter pipe can be used. Is elastically deformed in accordance with the displacement, and always presses against the inner surface thereof, so that the gap is completely closed and foreign matter is prevented from entering. Further, since the dust seal has a notch in a part in the circumferential direction, even if the diameter of the dust seal is reduced, there is no possibility that wrinkles or the like are generated on the outer peripheral surface.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a flexible pipe joint of the present invention, wherein 1 is a pair of left and right spigot pipes (small-diameter pipes) each having a flange 1a at an outer end thereof, and the opposing end faces of the pipe joints have predetermined dimensions. They face apart from each other.

A sleeve (large-diameter pipe) 2 is fitted on the outer peripheral surface of a substantially intermediate portion of both spigot pipes 1 with a required space therebetween. A rubber packing 3 is inserted between both open ends of the sleeve 2 and the outer peripheral surface of each spigot tube 1.

Reference numeral 4 denotes a pressing ring, which presses the packing 3 by engaging a holding bolt 5 with a plurality of mounting pieces 2a at both ends of the sleeve 2, thereby pressing the packing 3 to reduce a gap between the spigot tube 1 and the sleeve 2. Sealed.

The two spigot tubes 1 are movable by a predetermined dimension in the tube axis direction, and can bend with respect to the sleeve 2.

On the inner peripheral surface of the opposite end of each spigot tube 1,
A base end of a funnel-shaped dust seal 6 whose projecting end gradually increases in diameter in a tapered shape is fixed.

The dust seal 6 is formed of rubber or synthetic resin having elasticity, and has a V-shaped part extending in the circumferential direction of the enlarged diameter portion 6a in the pipe axis direction as shown in FIGS. A notch 7 is formed.

At the base of the notch 7, there is formed a clearance groove 8 extending in the circumferential direction. The escape groove 8 and the notch 7
Is for preventing wrinkles and the like from occurring in the enlarged diameter portion 6a when the enlarged diameter portion 6a is bent in the diameter decreasing direction as shown in FIG.

The distal end of the enlarged diameter portion 6a of the dust seal 6 is elastically pressed against the inner surface of the sleeve 2, and the cutout 7 in this state is open in a V-shape as shown in FIG. When the dust seal 6 is attached to the spigot tube 1, the notch 7 is preferably located at the uppermost position.
Foreign matter that easily accumulates at the lower portion can be prevented from entering through the notch 7.

As shown in FIG. 5, when the spigot tube 1 is vertically displaced and a large gap is formed between the spigot tube 1 and the sleeve 2, the enlarged diameter portion 6a of the dust seal 6 follows the displacement and elastically deforms. However, since the gap is always pressed against the inner surface of the sleeve 2, the gap is completely closed, and the entry of foreign matter is prevented.

FIGS. 6 and 7 show a modified example of the dust seal 6, in which a portion of the enlarged diameter portion 6a in the circumferential direction is cut off, the portions are overlapped, and the diameter is reduced in this state. It was done.

By doing so, the gap formed in the dust seal 6 is reduced as compared with the case where the notch 7 is provided, and the entry of foreign matter is further reduced.

FIG. 8 shows a further modification of the dust seal 6. A C-shaped elastic ring 9 made of spring steel, piano wire or the like is provided at the tip of the enlarged diameter portion 6a of the dust seal 6 shown in FIGS. Is buried.

In this case, the pressing force against the sleeve 2 is increased, so that the effect of preventing fine foreign substances from entering is enhanced.

FIG. 9 shows another embodiment of the present invention.

A receiving port 11a at the end of the other fluid pipe 11 is fitted into a large-diameter receiving port 10a formed at the end of one of the fluid pipes 10 by providing a required gap. The packing 12 is inserted between the inner surface of the mouth portion 10a and the insertion portion 11a, and is connected to each other by a pressing wheel 14 having a locking claw 13 for preventing detachment.

Each of the fluid tubes 10, 11 can flex at their joints. Therefore, similar to the above embodiment,
By providing the dust seal 6 at the end of the insertion port 11a, the gap created by the vertical displacement of the two fluid pipes 10 and 11 is completely closed by the enlarged diameter portion 6a of the dust seal 6, and foreign matter enters. Is prevented.

The present invention is not limited to the above embodiment.

For example, in the dust seal 6 of the embodiment, only a part of the enlarged diameter portion 6a in the circumferential direction is cut out, but the portion excluding the lower portion of the spigot tube 1 is largely cut out or the pipe diameter is reduced. May be cut or a plurality may be polymerized depending on the conditions.

Each of the diameter portions 6a of the dust seal 6 may be formed in a semicircular or arcuate shape and attached to the lower portion of the spigot tube 1 where foreign matter or the like easily accumulates.

The present invention can also be applied to a flexible pipe joint or the like comprising one spigot pipe and a flanged sleeve in addition to the above pipe joint.

[0037]

According to the present invention, the following effects can be obtained.

(A) Even if a gap is formed due to the displacement of the small-diameter pipe (spigot pipe) and the large-diameter pipe (sleeve), the dust seal is elastically deformed following the displacement of the large-diameter pipe, and is constantly pressed against the inner surface thereof. Therefore, the gap is completely closed, and it is possible to prevent foreign matter from entering.

(B) Since the dust seal has a notch in a part in the circumferential direction, even if the diameter of the dust seal is reduced, wrinkles and the like do not occur, and the sealability does not deteriorate due to the wrinkles.

(C) According to the second aspect of the invention, the dust seal can be easily deformed in the diameter reducing direction.

(D) According to the third aspect of the present invention, the gap formed in the notch can be reduced, so that the effect of preventing foreign matter from entering is enhanced.

(E) According to the fourth aspect of the present invention, since the foreign matter which is generally heavy flows near the bottom surface of the pipe, this structure can sufficiently prevent the foreign matter from entering and reduce the cost of the dust seal.

(F) According to the fifth aspect of the present invention, since the pressing force of the dust seal against the large-diameter pipe increases, it is possible to prevent fine foreign substances from entering.

[0044]

[Brief description of the drawings]

FIG. 1 is a central longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of the dust seal in a state where the diameter is enlarged.

FIG. 4 is a perspective view when the diameter is reduced.

FIG. 5 is a central longitudinal side view showing a state where a spigot tube and a sleeve are displaced.

FIG. 6 is a perspective view showing a modified example of the dust seal when the diameter is enlarged.

FIG. 7 is a perspective view when the diameter is reduced.

FIG. 8 is a longitudinal sectional view showing a further modified example of the dust seal.

FIG. 9 is a central longitudinal sectional view showing another embodiment of the present invention.

FIG. 10 is a schematic configuration diagram showing a conventional example.

FIG. 11 is a schematic configuration diagram showing a state of being displaced in the vertical direction in the same manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spigot pipe (small diameter pipe) 1a Flange 2 Sleeve (large diameter pipe) 2a Mounting piece 3 Packing 4 Press ring 5 Press bolt 6 Dust seal 6a Large diameter section 7 Notch 8 Escape groove 9 Elastic ring 10, 11 Fluid pipe 10a Receiving section 11a Insertion Portion 13 Locking Claw 14 Press Ring

Claims (5)

[Claims] 1. A small-diameter pipe, and a large-diameter pipe formed with a required gap formed on an outer peripheral surface of an open end thereof and fitted to the outside, and a seal member is provided in a gap between the small-diameter pipe and the large-diameter pipe. In a sealed flexible pipe joint, a radially elastically deformable dust seal having a cutout in at least a part of a circumferential direction is provided at an open end of the small diameter pipe located in the large diameter pipe. A flexible pipe joint, wherein a peripheral edge is provided so as to always contact an inner surface of a large diameter pipe. 2. The flexible pipe joint according to claim 1, wherein the notch has a V-shape whose front end is widened. 3. The flexible pipe joint according to claim 1, wherein the notch is formed so as to overlap when the dust seal is pressed against the large diameter pipe. 4. The flexible pipe joint according to claim 1, wherein the notch is formed to be large in an upper region of a circumference of the small diameter pipe and the large diameter pipe. 5. The tip of the enlarged diameter portion in the dust seal,
5. The flexible pipe joint according to claim 1, further comprising an elastic ring.