JP2015132373A - Flexible pipe joint and joint structure with flexible pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible pipe joint that is hardly broken even if unexpected high stress is applied to it and provide a joint structure including the flexible pipe joint.SOLUTION: A pair of companion flanges 3 connected to a pipe main body 2 are provided with a plurality of fixed pulleys 4 spaced apart by a certain distance in a circumferential direction and they are arranged in such a way that a position of the fixed pulley 4 at one companion flange 3 and a position of the fixed pulley 4 at the other companion flange are relatively displaced to each other in a circumferential direction, and these fixed pulleys 4 are connected by a flexible strip material 5 in an endless zig-zag. Even in the case that a bending stress is applied to cause a pipe main body 2 to be deformed like a bow shape, the stress force is supported by the entire flexible strip material 5 under a well-balanced state because it is connected in an endless manner through the fixed pulleys 4, an axis line of the pipe main body 2 is smoothly curved and there is no possibility that the flexible strip material 5 and the pipe main body 2 are broken.

Description

  The present invention relates to a pipe joint for connecting pipes such as water supply pipes.

  Seismic resistance is required for water supply and drainage pipes laid in buildings and various facilities, and flexible pipe joints are used in the pipes. In this flexible pipe joint, the pipe body is generally made of a flexible material having elasticity such as rubber, and the pipe body is embedded with a reinforcing material such as a tire cord in order to improve pressure resistance.

A pair of companion flanges are attached to both ends of the flexible pipe joint. An inner flange-shaped seat is formed on the inner periphery of the companion flange, and the small flange of the pipe body is seated there, whereby the pipe body and the companion flange are engaged. And the phase flange of a flexible pipe joint and the flange of piping are integrally connected with a volt | bolt etc.
Even when a certain stress is applied between the pipe and the flexible pipe joint and a displacement such as expansion or contraction occurs, the function of the pipe can be maintained by the action of the pipe joint.

However, if a large earthquake occurs and a sudden tensile load is applied to the pipe body, the pipe joint itself may be destroyed, making it difficult to ensure reliability for long-term use. Met.
In order to solve this problem, the structure of the pipe joint of the following patent document is proposed.
As shown in FIG. 7, the wire flanges 8 connect the companion flanges 3 attached to both ends of the tube body 2 so that the tube length of the tube body 2 can be kept constant.
As shown in FIG. 7, the wire ropes 8 are arranged 180 degrees apart in the circumferential direction of the companion flange 3 and are connected linearly.
When the companion flanges 3 are directly connected to each other by the wire rope 8, the flexible pipe joint can suppress the elongation of the pipe body 2 in the axial direction.
There is an example in which a tire rod is used instead of the wire rope 8.

JP 2005-337403 A Japanese Utility Model Publication No. 51-119611

However, when bending stress is applied such that the flexible pipe joint is deformed into an arcuate shape, that is, as shown in FIG. 7 (showing, as an example, connecting the companion flanges 3 with wire ropes 8), When the axis of the main body 2 is decentered, the wire rope 8 on the side where the tube main body 2 contracts (right side on the paper surface) is in a loosened state, while the wire rope 8 on the side where the tube main body 2 extends (left side on the paper surface) It becomes an extended state.
At this time, the axis of the tube body 2 is distorted and curved. Then, a large force is applied to the tube main body 2 locally, particularly to the extended portion, and the tube main body 2 may be broken from the portion.
An object of the present invention is to use a flexible pipe joint that applies even force to the entire flexible pipe joint even when a relative positional shift occurs between the pipes, and is less likely to be broken. It is to provide a joint structure.

The invention according to claim 1 is a flexible pipe joint in which a pair of companion flanges (3) project from both ends of a pipe body (2), and fluid flows through the inside of the pipe body (2).
Fixed pulleys (4) are arranged on the opposite sides of the pair of phase flanges (3), respectively, at regular intervals in the circumferential direction, and fixed pulleys (4) of one phase flange (3) are arranged. ) And the position of the stationary pulley (4) of the other companion flange (3) are shifted from each other in the circumferential direction,
One metal flexible strip (5) connecting between the pair of companion flanges (3) is provided, and the flexible strip (5) is endlessly zigzag between each fixed pulley (4). Stretched and connected,
When the axis of the tube body (2) is curved, the flexible strip (5) is stretched outside the curve, and it is configured so that it is reduced inside the curve by the length of the stretch. It is a flexible pipe joint characterized by these.

The invention according to claim 2 is the flexible pipe joint according to claim 1,
The fixed pulley (4) comprises a wheel (4a) and a bracket (4b) for holding the wheel (4a),
Each phase flange (3) is provided with a large number of bolt holes (6) for fastening a pipe flange on the same diameter at equal intervals.
A plurality of bracket holding portions (7) are arranged in a circumferentially spaced manner integrally with the phase flange (3) on the radially outer side of the bolt hole (6),
The flexible pipe joint is characterized in that the bracket (4b) of the fixed pulley (4) is attached to the bracket holding portion (7).

Invention of Claim 3 is the flexible pipe joint in any one of Claim 1 or Claim 2,
The flexible strip (5) is a flexible pipe joint made of a chain or wire rope.

The invention according to claim 4
A joint structure using the flexible pipe joint according to any one of claims 1 to 3,
An expansion joint (10) that expands and contracts in the fluid flow direction with the outer pipe (11) slidably fitted to the inner pipe (12) is installed adjacent to the flexible pipe joint (1). The joint structure is characterized in that the companion flange (13) of the expansion joint (10) and one companion flange (3) of the flexible pipe joint (1) are connected.

In the flexible pipe joint according to claim 1, a plurality of constant pulleys 4 are provided at regular intervals in the circumferential direction on a pair of phase flanges 3 connected to the pipe body 2, and the constant pulleys 4 of the phase flange 3 on one side. And the position on the other side are displaced relative to each other, and between the fixed pulleys 4 are zigzag (meandering between the companion flanges 3) in a zigzag manner (endless) between the endless pulleys (endless). It is connected and stretched.
Thus, even when bending stress is applied such that the tube body 2 is deformed into an arcuate shape, the shrinkage amount on the shrinking side and the elongation amount on the stretching side are offset, and the entire flexible strip 5 is applied. The force is applied in a well-balanced manner, the axis of the pipe body 2 is smoothly bent, and partial stress concentration is prevented from being applied to the flexible pipe joint as much as possible, and its durability can be improved.
Furthermore, even when pressure is applied in the direction in which the flexible pipe joint expands and contracts, the maximum length of the pipe body 2 is restricted by the flexible strip 5 being supported, and the pipe body 2 damage is prevented. Similarly, even if an external force for bending and expansion / contraction is simultaneously applied to the joint, it is possible to prevent an excessive external force from being applied to the joint.

In the flexible pipe joint according to claim 2, a plurality of bracket holding portions 7 are integrally protruded radially outward of the companion flange 3 so as to protrude in the circumferential direction, and the bracket 4 b of the fixed pulley 4 is provided as a bracket holding portion. 7 is fixed.
Therefore, when the flange of the pipe and the companion flange 3 of the pipe body 2 are fastened, the pipes can be tightly fastened without causing interference between the bracket 4b of the fixed pulley 4 and the pipe flange. it can.

Invention of Claim 3 is a flexible pipe joint in which the flexible strip 5 consists of a chain or a wire rope in the said structure. In either case, the flexible pipe joint can be protected smoothly.
The invention according to claim 4 is the one in which the expansion joint 10 that expands and contracts in the fluid flow direction is disposed adjacent to the flexible pipe joint 1 according to claims 1 to 3.
With this configuration, even in the case of a flexible pipe joint in which the amount of extension of the pipe main body 2 is restricted as in claim 1, the expansion and contraction of the flexible pipe joint is restricted by the adjacent expansion joint 10. Can be complemented.

The partially broken front view of the flexible pipe joint of this invention. FIG. The expanded view which shows the connection state of the flexible strip 5 of this invention. Explanatory drawing which shows the effect | action of the flexible strip 5 when stress is added to the flexible pipe joint of this invention. Explanatory drawing which shows an example of the use condition of this invention. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. Explanatory drawing which shows the state to which the stress of the conventional type flexible pipe joint was added.

Next, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a flexible pipe joint 1 according to the present invention, FIG. 1 is a partially broken front view thereof, FIG. 2 is a plan view thereof, and FIG. It is an expanded view which shows a connection state.

(Structure of flexible pipe joint 1)
In this flexible pipe joint 1, the pipe body 2 is made of a flexible material such as an elastic rubber material, and the longitudinal section thereof is formed in a bellows shape. The engagement relationship between the pipe body 2 and the companion flange 3 is as shown in the background art.
In the phase flange 3, bolt holes 6 are formed at equal intervals in the circumferential direction in order to connect to the flange of the pipe.

(Characteristics of the flexible pipe joint 1 of the present invention)
The characterizing portion of the present invention lies in the connection structure of the flexible strip 5 that connects the pair of companion flanges 3 arranged at both ends of the pipe body 2.
Each of the phase flanges 3 is provided with a plurality of (four in this example) bracket holding portions 7 integrally projecting radially outward from the position of the bolt hole 6 in the circumferential direction, and bolts at the center. A hole is drilled. Each bracket holding portion 7 holds a fixed pulley 4 including a bracket 4b and wheels 4a via bolts.

When the companion flange 3 is attached to the small flange 2d of the pipe body 2, as shown in FIG. 1, the wheels 4a of the fixed pulley 4 face each other, the position of the fixed pulley 4 of one companion flange 3, and the other companion flange 3 The position of the fixed pulley 4 is shifted by a half pitch in the circumferential direction.
As shown in FIG. 1, the pair of companion flanges 3 are connected via a fixed pulley 4 by a single flexible strip material 5 made of metal. At that time, the flexible strip 5 is inserted so as to connect the adjacent fixed pulleys 4 in plan view. At this time, as shown in FIG. 3, the pair of phase flanges 3 are connected endlessly (endless) in a state of being spaced apart from the pipe body while meandering up and down in the opening direction of both ends of the flexible pipe joint. In this example, a chain is used for the flexible strip 5, but instead, a wire rope may be used if it can be connected endlessly.

  The flexible pipe joint 1 configured as described above is fastened to a flange of another pipe via the phase flange 3. At this time, as described above, the bracket holding portion 7 is formed radially outward from the position of the bolt hole 6, so that when the flanges are fastened, the bracket fixing portion that protrudes from the flange of the other pipe and the companion flange 3 is used. The joint and the pipe can be brought into close contact with each other without interfering with the other bolt.

(Function)
Next, the effect | action of the flexible pipe joint 1 of this invention is demonstrated based on FIG.
When a bending stress that deforms the flexible pipe joint 1 into an arcuate shape is applied, as shown in FIG. 4, the axis of the pipe body 2 is decentered and the pipe body 2 is contracted (right side on the paper surface). The flexible strip 5 shortens following the contraction. And the flexible strip 5 on the side (left side of the paper) on which the tube main body 2 extends becomes longer following the extension. That is, although the flexible strip 5 has a part that becomes longer and a part that becomes shorter, the entire length does not change because it is connected endlessly.
In addition, since the flexible strip 5 is connected via the fixed pulley 4, the bending stress is distributed over the entire flexible strip 5, and an excessive force is not applied to a part. By this action, the axis of the tube body 2 is also smoothly curved, and the tube body 2 is prevented from being destroyed.
Needless to say, the flexible strip 5 can suppress the axial extension of the flexible pipe joint 1.

(Usage example of flexible pipe joint 1)
Next, the usage example of the flexible pipe joint 1 of this invention is shown in FIG.
Since the flexible pipe joint 1 is restrained from extending in the axial direction by the flexible strip 5, it is possible to use the flexible pipe joint 1 in combination with another joint that can compensate for the expansion and contraction action. desirable.
In the usage example of FIG. 5, a pair of flexible pipe joints 1 are disposed at both ends in the axial direction of the rigid expansion joint 10. As shown in FIG. 6, the expansion joint 10 includes an inner tube 12, a piston 14 fixed to the outer periphery of the inner tube 12, a piston case 18 in which the piston 14 is slidably fitted, and screwed at both ends. An annular first ring 16 and a second ring 17 to be attached, and an outer tube 11 to which the inner tube 12 is fitted.

(Configuration of expansion joint 10)
In this example, the inner pipe 12 is made up of two members, a first pipe 12a and a second pipe 12b.
The first pipe 12a is formed of an elongated cylindrical body having a companion flange 13 at one end, and a small flange is integrally formed radially outward at the other end, and the fluid is located away from the first pipe 12a. Inflow holes 20 are formed at regular intervals in the outer circumferential direction.
Then, one end of the second pipe 12b is integrally formed with a small flange radially outward, like the other end of the first pipe 12a, and the other end slides on the outer cylinder 11 at the outer periphery. It is movably fitted. The small flange of the first pipe 12a and the small flange of the second pipe 12b are attached to form an engaging portion of the piston 14.
The outer tube 11 is formed of an elongated cylindrical body having a companion flange 13 at the other end, and has an inner diameter slightly larger than that of the inner tube 12. Moreover, the outer periphery of one end part is formed in a step, and the groove | channel which arrange | positions packing is formed in the circumferential direction on the internal peripheral surface.

Next, the piston 14 is composed of a first piston member 14a and a second piston member 14b which are in contact with each other. Insertion holes are formed in the plane of the first piston member 14a and the plane of the second piston member 14b so as to be spaced apart in a plurality of circumferential directions. Bolts are screwed into the insertion holes.
In this example, the insertion hole of the second piston member 14b penetrates, but the insertion hole of the first piston member 14a does not penetrate.

  The second piston member 14b and the first piston member 14a come into contact with each other, and a bolt 15 is screwed into the insertion hole to complete the piston 14. An annular groove is formed on the inner and outer peripheral surfaces of the piston 14, and an O-ring is fitted therein. Next, the piston case 18 is slidably fitted on the outer peripheral surface of the piston 14. Screws for screwing the pair of first ring 16 and second ring 17 are engraved on the inner peripheral surfaces of both ends.

The second ring 17 is threaded so that the threaded portion of one end of the piston case 18 can be screwed onto the outer peripheral surface thereof. Further, the inner peripheral surface is fitted with a stepped end portion of the outer tube 11. In the plane portion, air vent holes 19 are formed so as to be spaced apart in the circumferential direction.
The first ring 16 is threaded so that the threaded portion of the other end of the piston case 18 can be screwed onto the outer peripheral surface thereof. Further, the inner peripheral surface of the inner pipe 12 is fitted with the first pipe 12a.
The contact portion of each member is provided with an annular sealing material (such as a rubber O-ring) in order to maintain liquid tightness and air tightness.

(Function)
The operation of the expansion joint 10 thus configured will be described.
The inner tube 12 is slidably inserted into the inner peripheral surface of the outer tube 11. The companion flanges 13 disposed at both ends thereof are connected to the companion flanges 3 of the pair of flexible pipe joints 1 via bolts.
When stress is applied in the axial direction due to an earthquake or the like, the inner tube 12 of the expansion joint 10 slides in the axial direction with respect to the outer tube 11. At this time, the piston 14 moves together with the inner tube 12, and the space volume between the piston 14 and the second ring 17 changes. Then, air existing in the meantime flows out from the air vent hole 19 or air from outside enters.
Further, an internal fluid (liquid) flows in and out between the piston 14 and the first ring 16 through the inflow hole 20. The expansion joint 10 has an effect of complementing the expansion / contraction restriction in the axial direction of the flexible pipe joint 1 of the present invention.

Next, when a pipe (not shown) connected to the downstream side in the fluid flow direction of the expansion joint 10 is bent, the pressure equal to the product of the internal area of the inner pipe 12 and the fluid pressure when the internal fluid flows there Joins in that direction.
At this time, the internal fluid flows between the inner tube 12 and the piston case 18 through the flow hole 20 of the inner tube 12, and the disconnection between the outer periphery of the inner tube 12 and the inner periphery of the piston case 18 occurs. A pressure equal to the product of the area and the fluid pressure is applied to the piston 14, and the pressure is applied in the direction opposite to the fluid flow direction.
Thus, by making the cross-sectional area of the piston 14 equal to the cross-sectional area of the inner surface of the inner tube 12, the expansion joint 10 is in an equilibrium state. The expansion joint 10 serves as a so-called balancer.
That is, with this configuration, a balancer function is added to the expansion joint, and even when sudden stress is applied, it can be absorbed without difficulty and the expansion joint 10 is less prone to breakage. Like this invention, when it uses in combination with the flexible pipe joint 1 by which expansion-contraction regulation is carried out, the joint structure which does not raise | generate destruction easily can be provided.

1 Flexible pipe joint 2 Pipe body
2a Tire cord
2b Reinforcement ring
2c Reinforcing ring
2d Small flange 3 Phase flange 4 Fixed pulley
4a wheels
4b Bracket 5 Flexible strip 6 Bolt hole

7 Bracket holder 8 Wire rope 9 Piping
10 Expansion joint
11 Outer pipe
12 Inner pipe
12a First pipe
12b Second pipe
13 Companion flange

14 Piston
14a First piston member
14b Second piston member
15 Locking piece
16 First ring
17 Second ring
18 Piston case
19 Air vent hole
20 Inlet hole

Claims (4)

In a flexible pipe joint in which a pair of companion flanges (3) project from both ends of a pipe body (2) and fluid flows through the inside of the pipe body (2),
Fixed pulleys (4) are arranged on the opposite sides of the pair of phase flanges (3), respectively, at regular intervals in the circumferential direction, and fixed pulleys (4) of one phase flange (3) are arranged. ) And the position of the stationary pulley (4) of the other companion flange (3) are shifted from each other in the circumferential direction,
One metal flexible strip (5) connecting between the pair of companion flanges (3) is provided, and the flexible strip (5) is endlessly zigzag between each fixed pulley (4). Stretched and connected,
When the axis of the tube body (2) is curved, the flexible strip (5) is stretched outside the curve, and it is configured so that it is reduced inside the curve by the length of the stretch. A flexible pipe joint. The flexible pipe joint according to claim 1, wherein
The fixed pulley (4) comprises a wheel (4a) and a bracket (4b) for holding the wheel (4a),
Each phase flange (3) is provided with a large number of bolt holes (6) for fastening a pipe flange on the same diameter at equal intervals.
A plurality of bracket holding portions (7) are arranged in a circumferentially spaced manner integrally with the phase flange (3) on the radially outer side of the bolt hole (6),
A flexible pipe joint, wherein the bracket (4b) of the fixed pulley (4) is attached to the bracket holding portion (7). In the flexible pipe joint according to claim 1 or 2,
A flexible pipe joint, wherein the flexible strip (5) is a chain or a wire rope. A joint structure using the flexible pipe joint according to any one of claims 1 to 3,
An expansion joint (10) that expands and contracts in the fluid flow direction with the outer pipe (11) slidably fitted to the inner pipe (12) is installed adjacent to the flexible pipe joint (1). A joint structure characterized in that the companion flange (13) of the expansion joint (10) and one companion flange (3) of the flexible pipe joint (1) are connected.

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