JPH06294489A - Pressure equilibrium type expansion pipe joint - Google Patents

Abstract

PURPOSE:To provide a pressure equilibrium type expansion pipe joint reducing the fluid pressure to an anchor, shrinking the outer diameter of a joint, and capable of being operated when buried in the ground, and having a simple and strong structure by balancing the volume change of a fluid in the expansion joint with a main pipe, external pressure bellows tanks, and auxiliary bellows tanks. CONSTITUTION:When the outer tube 1 of a pressure equilibrium type expansion pipe joint is pressed to a fixed tube 5 side by the extension of a pipe 3, external pressure bellows tanks A1, A2 and auxiliary bellows tanks B1, B2 constituted of bellows 2a, 2b, 2c, 2d, 2e between flanges 4b, 4c, 4d from a main pipe 4 fixed to the fixed tube 5 via a flange 4a and flanges 1a, 1b, 1c from the outer tube 1 are balanced, i.e., the expansion quantities of the external pressure bellows tanks A1, A2 are applied to the cross sectional area of the main pipe 4 because portions of both end flanges 1a, 1d are not changed via through holes 6a, 6b. The shrunk volume of the main pipe 4 is absorbed by the auxiliary bellows tanks B1, B1, and the volumes of the auxiliary bellows tanks B1, B2 can be made 1/2 of the shrunk volumes of the external pressure bellows tanks A1, A2.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bellows type pressure balance type expansion tube joint for reducing the force applied to the anchor due to the rise of fluid in the expansion tube due to thermal expansion of the tube member.

2. Description of the Related Art The most widely used type is an external pressure bellows type pipe joint. In this external pressure bellows type pipe joint, as shown in FIG. 3, an outer cylinder b is fitted around the outer periphery of a main pipe a, and one auxiliary bellows tank d consisting of a bellows c is provided in the middle thereof, whereby an external pressure bellows tank of the main pipe a is provided. It had a structure for absorbing the contracted volume of e.

In the conventional external pressure bellows type pipe joint, the expansion joint has an excessively large outer diameter in order to absorb the contraction volume of the external pressure bellows tank with one auxiliary bellows tank. Therefore, it is inconvenient to use.

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present invention addresses the above problem by providing a plurality of auxiliary bellows connected to the outer cylinder by bellows on the outer circumference of a main pipe fitted into the outer cylinder. (EN) An external pressure bellows type pressure balancing type joint in which a tank is provided and the volume changes thereof are equal to those of an external pressure bellows tank connected to a main pipe so that the outer diameter of the joint is reduced.

When the outer cylinder 1 is pushed toward the fixed cylinder 5 side by the expansion of the pipe 3 due to heat, the flanges 4b to 4d from the main pipe and the flange 1a from the outer cylinder 1 are fixed to the fixed cylinder 5 via the flange 4a. The external pressure bellows tanks A ₁ and A ₂ and the auxiliary bellows tanks B ₁ and B _{2 which} are composed of bellows between 1 c and 1 c are balanced. For example, in the balanced type having _two external pressure bellows tanks A ₁ and A ₂ and sub bellows tanks B ₁ and B ₂ , the expansion and contraction amount of the external pressure bellows tank is
Since there is no change in the portion between the flanges of 1d through the through holes 6a and 6b, the volume of the cross sectional area of the main pipe 4 is obtained. Further, one end of the bellows 2b is bonded to the outer peripheral portion of the inner flange 1b of the first outer cylinder 1 leaving a through hole 6a, and the other end is provided on the outer periphery of the first main pipe 4 and bonded to the outward flange 4b. The first sub-bellows tank B ₁ is formed, and the flange 1 of the outer cylinder 1 is formed.
b A bellows 2c having the same diameter and the same length as the external pressure bellows tank A ₁ along the outer circumference of the main pipe 4 leaving a through hole 6b in the outward bonding portion on the outer circumference.
Of the second sub-bellows tank B ₂ by adhering the other end of the bellows 2c to the outer circumference of the flange 4c from the main pipe 4
Since the contracted volume of the main pipe 4 is absorbed by the _two auxiliary bellows tanks B ₁ and B ₂ , since the volume is formed, the volume of the auxiliary bellows tank is set to 1/2 of the contracted volume of the external pressure bellows tanks A ₁ and A _2. be able to. Also, if there are three sub-bellows tanks, 1/3
Becomes Therefore, the outer diameter of the expansion joint can be reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an embodiment of a pressure balancing type expansion joint according to the present invention, which will be described below with reference to the drawings. Figure 1
Is an embodiment in which two external pressure bellows tanks and two sub-bellows are provided. Reference numeral 1 is an outer cylinder, and the outer cylinder is provided with bellows 2a and 2b, which will be described later, at a certain distance toward the inner circumference. , 2c,
Flange 1a, 1b, which attaches one end of each of 2d, 2e,
A flange 1e provided with 1c and 1d and connected to a flange 3a provided on the pipe system pipe 3 at one end of the outer cylinder 1
Is equipped with. Reference numeral 4 denotes a main pipe, one end of which is provided with a flange 4a which is connected to a flange 5a provided on the fixed pipe 5, the other end of which is fitted into the outer cylinder 1 and further toward the tip side of the main pipe 4. Flange 4b, 4c, 4d for mounting one end of each of the bellows 2a, 2b, 2c, 2d, 2e is provided outwardly on the outer periphery at the same fixed distance from the flange 4a. Outer circumference of the flange 1a of the outer cylinder 1 and the flange 4
The inner circumference of b is connected by the bellows 2a to form a first external pressure bellows tank A ₁ . Next, a through hole 6a is formed in the inner peripheral portion of the inward flange 1b of the outer cylinder 1, one end of the bellows 2b is attached while leaving the through hole 6a, and the other end of the bellows 2b extends along the inner circumference of the outer cylinder 1. Outward flange 4b of main pipe 4
To connect to the outer periphery of the forming a first sub-bellows tank B _1. Wherein an inner peripheral portion of the outward flange 4b are drilled a hole 7a through the first sub-bellows tank B _1. Further, the outward flange 4c of the main pipe 1 is adhered along the outer circumference of the main pipe 1 with one end of the bellows 2c having the same diameter and the same length as the bellows 2a, leaving a through hole 7b, and the other end of the bellows 2c is attached to the outer cylinder 1. The second external pressure bellows tank A ₂ is formed by adhering to the outer peripheral side of the inward flange 1b. The flange 4c extends along the inner circumference of the outer cylinder 1 between the inward flange 1c of the outer cylinder 1 and the bellows 2b.
The bellows 2d of the径同length by bonding a respective end portion and the second sub-bellows tank B ₂ form, also the flange 1c of the outer tube 1 and drilled an inner circumferential portion and a through hole 6b second external pressure bellows Tank A ₂
I have contacted. Further, the outward flange 4 from the main pipe 4
On the outer periphery of d, one end of a bellows 2e having the same diameter and the same length as the bellows 2a is connected to the outer peripheral side, and the other end of the bellows 2e extends along the outer periphery of the inward flange 1c from the outer periphery 1 to the outer periphery of the main pipe 4. Are glued together. That is, two auxiliary bellows tanks B, each of which consists of outer bellows 2b, 2d along the inner cylinder of the outer cylinder 1 and bellows 2a, 2c, 2e along the outer circumference of the main pipe 4.
It is composed of a and Bb. In the figure, B is a sliding tube having a through hole 9. Next, FIG. 2 shows another embodiment, which is the same as the embodiment of FIG. 1, except that one auxiliary bellows tank and one external pressure bellows tank are added, that is, the outer cylinder 1 shown in FIG. An inward flange 1f having a hole 6c and a through hole 7c in the main pipe 4
By bonding an outer bellows 2f between the outward flange 4e provided, the third sub-bellows tank B ₃ third external pressure bellows tank A
₃ is added so that the contraction volume of the main pipe 4 is absorbed by the three auxiliary bellows tanks, and the contraction volume is reduced to 1/3 so that the outer diameter of the expansion pipe joint can be reduced.

As described above, the external pressure bellows tank and the auxiliary bellows tank are provided, and the contraction volume of the main pipe is absorbed by the auxiliary bellows tanks by adding each bellows tank. Can be made smaller,
It is possible to work even if it is buried in the ground, and there are effects such as a simple structure and durability.

[Brief description of drawings]

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

FIG. 2 is a partial cross-sectional side view of another embodiment of the pressure balancing type expansion joint.

FIG. 3 is a side view in which a part of a conventional expansion joint is sectioned.

[Explanation of symbols]

1 outer cylinder 1a~1f, 3a, 4a~4f, 5a flange 2a~2f bellows 3 pipe 4 main pipe 5 fixed tube 6 a to 6 c, 7 a to 7 c hole 8 sliding tube 9 holes A ₁ to A ₃ external pressure bellows tank B ₁ .about.B ₃ sub bellows tank

Claims (1)

[Claims] 1. In a telescopic joint provided in a pipe system, a change in the volume of fluid in the telescopic joint is balanced by a plurality of external pressure bellows tanks and sub bellows tanks provided between a main pipe and an outer cylinder fitted with the main pipe. The pressure balance type expansion and contraction pipe joint is characterized by reducing the fluid pressure to the anchor and reducing the outer diameter of the joint.