JPH10141565A - Bellows type expansion pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb triaxial excessive change simultaneously by one bellows type expansion pipe joint and prevent buckling displacement caused by pressure by holding outer guide rings slidably by pins in opposition to inner guide rings provided on the intermediate outer peripheral side of a bellows. SOLUTION: The intermediate outer peripheral side root parts of lateral bellows 1, 1 are fixedly provided with inner guide rings 6, 6 with the respective outer peripheral surface 6a bulged in circular cross section. Opposed to the inner guide rings 6, 6, outer guide rings 7, 7 with the inner peripheral surface 7a recessed in circular cross section are held on the outer peripheral side slidably in the longitudinal direction of arms 8, 8 and arms 14, 14. That is, pins 10, 10 planted in the outer peripheral surface of the lateral outer guide rings 7, 7 at intervals of 90 deg. are inserted through oblong holes 9, 9, 15, 15 bored in the longitudinal direction of the arms 8, 8, 14, 14 so that the lateral outer guide rings 7, 7 are held slidably in the longitudinal direction of the arms 8, 8, 14, 14 by the pins 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bellows type expansion joint, and more particularly to a bellows type expansion joint which absorbs triaxial (X, Y, Z) excessive displacement and prevents buckling displacement due to pressure. .

[0002]

2. Description of the Related Art There are three types of bellows type expansion joints, including a single type, a double type, a universal type, a swing type, a straight pipe pressure balance universal type, and a curved pipe pressure balance universal type. As shown in FIG. 13, the pipes 2, 2 connected by the bellows 1 are held within a predetermined interval by stay bolts 4 stretched between the column flanges 3, 3.

Conventionally, in the bellows type expansion joint, buckling due to excessive displacement from the pipe axis direction X is prevented by the stay bolt 4 from the outside or the sleeve 5, the pipe 2 from the inside.
Guided by 2. In addition, the axial direction Y and the axial direction Z
In order to prevent buckling due to excessive displacement from the outside, the number of peaks of the bellows 1 is reduced and the length of the expansion joint is increased.

In order to select a bellows-type expansion joint that absorbs excessive amounts of triaxial displacement in the pipe axis direction X, the axis perpendicular direction Y, and the axis perpendicular direction Z, the buckling accompanying the number of bellows peaks is examined, and the buckling is examined. If the number of peaks is large enough to cause the above, instead of using one bellows-type expansion joint, two types of pipe-type bellows-type expansion joint and a pipe-shaft type bellows-type expansion joint will be used. When buckling is likely to be avoided or buckling is likely to occur, a hinge plate, a shaped steel, a gimbal ring and the like are attached from the outside. Therefore, it becomes a large-scale facility for absorbing the triaxial excessive displacement (earthquake displacement and the like), and requires a large space for installation and also takes time and effort.
In addition, maintenance is poor.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a single bellows type expansion joint which simultaneously absorbs triaxial excessive displacement, prevents buckling displacement due to pressure, and reduces the size of the equipment. It is an object of the present invention to provide a bellows type expansion pipe joint which requires a small space for installation, requires no labor, and is easy to maintain.

[0006]

The bellows type expansion joint according to the present invention for solving the above-mentioned problems has a basic structure in which pipes connected by bellows are held within a predetermined interval by stay bolts. In the bellows type expansion joints of various types such as single type, double type, universal type, swing type, straight pipe pressure balance universal type, curved pipe pressure balance universal type, the outer peripheral surface has a circular cross section on the middle outer peripheral side of the bellows. An inner guide ring bulging in an arc shape is provided, and an outer guide ring whose inner circumferential surface is formed into an arc-shaped cross section is opposed to the inner guide ring, and the outer guide ring is formed from the pipes on both sides of the bellows to the bellows side. At a position shifted in the circumferential direction
The arm is slidably held by a pin in a long hole in the longitudinal direction of the arm protruding in parallel with the shaft center line.

In the above bellows type expansion joint, the outer peripheral surface of the inner guide ring and the inner peripheral surface of the outer guide ring are provided with:
Preferably, a friction reducing treatment has been performed. Further, it is preferable that a certain clearance is provided between the outer peripheral surface of the inner guide ring and the inner peripheral surface of the outer guide ring. Also, the outer guide surface of the inner guide ring is
It may be divided and consist of a plurality of projecting surfaces. Further, the inner guide ring itself may be divided in the circumferential direction. Further, the outer guide ring may be divided in the circumferential direction. In addition, a reinforcing ring may be attached to a valley on the outer peripheral side of the bellows to form a bellows type expansion joint for high pressure. In this bellows type expansion joint, the inner guide ring may have a structure in which the outer diameter of the adjacent reinforcing ring is increased and the outer peripheral surface of the adjacent reinforcing ring is curved in an arc-shaped cross section.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bellows type expansion joint of the present invention will be described with reference to the drawings. In the embodiment shown in FIG. 1, the left and right end tubes 2, 2 connected by the bellows 1 are fixed at a fixed distance by stay bolts 4 stretched between support flanges 3, 3 provided on the end tubes 2, 2. In a single bellows-type telescopic joint in which a sleeve 5 covering the bellows 1 is attached to the end pipe 2, an outer peripheral surface 6 a has an arc-shaped cross section at a valley on the intermediate outer peripheral side of the bellows 1. A wide outer guide ring 7 having an inner peripheral surface 7a formed into an arcuate cross-section on the outer peripheral side thereof facing the inner guide ring 6 is fixed to the left and right ends. As shown in FIG. 2, the pipes 2, 2 protrude from the column flanges 3, 3 of the pipes 2, 3 on the bellows 1 side at positions shifted from each other by 90 degrees in the circumferential direction, in parallel with the axial center line L as shown in FIG. 1. The arms 8, 8 were held slidably in the longitudinal direction. That is, 90 mm is provided on the outer peripheral surface of the outer guide ring 7 in the elongated holes 9, 9 formed in the longitudinal direction of the arms 8, 8.
The pins 10 planted at intervals were inserted, and a washer 11 was welded to the upper end to prevent the pins 10 from coming off. The outer guide ring 7 was held by the pins 10 so as to be slidable in the longitudinal direction of the arms 8.

In the embodiment shown in FIG. 3, the left end pipe 2 and the intermediate pipe 12 are connected to each other, and the intermediate pipe 12 and the right end pipe 2 are connected to the bellows 1.
The end pipes 2, 2 are held within a certain interval by stay bolts 4 stretched between support flanges 3, 3 provided on the left and right end pipes 2, 2, and the left bellows 1 is internally provided. In a universal type bellows type expansion joint in which a sleeve 5 covering the bellows 1 is attached to the end pipe 2 and the sleeve 5 covering the right bellows 1 is attached to the intermediate pipe 12, the left and right bellows 1,
1, inner guide rings 6 and 6 whose outer peripheral surfaces 6a bulge in an arc shape in cross section are fixed to the valleys on the intermediate outer peripheral side. Peripheral surface 7
a is a wide outer guide ring having an a-shaped cross section
To the bellows 1 side from the support flange 3 of the left end pipe 2 and one flange 13 of the intermediate pipe 12 and the right end pipe 2
The support center flange 3 and the intermediate pipe 12 are located on the right side of the bellows 1 from the other flange 13 at positions shifted from each other by 90 degrees in the circumferential direction as shown in FIG. Arm 8,8, arm 14,1 protruding in parallel with
4 was slidably held in the longitudinal direction. That is, arm 8,
Slots 9, 9, 1 drilled in the longitudinal direction of 8, 14, 14
Pins 10, 10 planted at 90 ° intervals are respectively inserted into the outer peripheral surfaces of the left and right outer guide rings 7, 7, and the washers 11 are welded to the upper end portions to prevent the left and right outer guide rings 7, 7 from coming off. Rings 7, 7 are connected to pins 8, 10 by arms 8, 8, 1
4 and 14 were slidably held in the longitudinal direction.

[0010] The triaxial shaft constituted by the inner guide ring 6, the outer guide ring 7, the arms 8, 8 (14, 14) with the elongated holes 9 (15), the pins 10, and the washers 11 shown in the above embodiments. The large displacement absorbing mechanism includes a double bellows type expansion joint as shown in FIG. 5, a swing type bellows expansion joint as shown in FIGS. 6a and 6b, and a straight pipe as shown in FIG. The present invention is also applied to a bellows type expansion joint of a pressure balanced universal type and a bellows type expansion joint of a curved pipe pressure balance as shown in FIG.

The outer peripheral surface 6a of the inner guide ring 6 and the inner peripheral surface 7a of the outer guide ring 7 in the various types of bellows type expansion joints described above include tetrafluoroethylene (trade name: Teflon). The inner guide ring 6 and the outer guide ring 7 may be smoothly operated by performing a friction reducing process such as coating a fluoride or resin film or applying a paint. Further, as shown in FIG. 9, a fixed clearance C is provided between the outer peripheral surface 6a of the inner guide ring 6 and the inner peripheral surface 7a of the outer guide ring 7.
It is preferable that the inner guide ring 6 and the outer guide ring 7 slide smoothly.

In the various types of bellows type expansion joints described above, the inner guide ring 6 has a guide surface on the entire outer peripheral surface 6a. However, the present invention is not limited to this, and as shown in FIG. For example, a guide surface including four projecting surfaces 20 may be used. In this case, the end of the protruding surface 20 may be provided with a radius 20a so as not to be caught on the inner peripheral surface of the outer guide ring 7. Although the inner guide ring 6 is an integral part of the entire circumference, the inner guide ring 6 may be divided into two parts as shown in FIG. Good. The outer guide ring 7 is an integral part of the entire circumference, but is divided into two parts as shown in FIG. 10 and slidably held on the arms 8, 8 by the pins 10, and then the plate 22 is welded. They may be combined.

In the above-mentioned various types of bellows type expansion joints, a reinforcing ring 23 is attached to the outer valley of the bellows 1 as shown in FIG. It may be. In each of the bellows type expansion joints in which the reinforcing ring 23 is mounted on the outer peripheral valley of the bellows 1 as described above, the inner guide ring 6 is adjacent to the intermediate outer peripheral side of the bellows 1 as shown in FIG. The outer diameter of the reinforcing ring 23 is increased, and the reinforcing ring 2 adjacent thereto is increased.
The guide ring 6 ′ may have a structure in which the outer peripheral surface of the pair 3 is formed into a pair and bent into an arc shape in cross section.

As described above, the bellows type expansion joints of various types according to the embodiment of the present invention have the inner guide ring 6.
(6 '), an outer guide ring 7, an arm 8, 8 (14, 14) with a long hole 9 (15), a pin 10, and a washer 11 are provided. For excessive displacement in the tube axis direction X, the arms 8, 8 (14,
14) The outer guide ring 7 is inserted through the pin 10 which is inserted through the long hole 9 (15) and is prevented from coming off by the washer 11.
The inner guide ring 6 (6 ') moves to displace the bellows 1 fixing the inner guide ring 6 (6') to the valley on the intermediate outer peripheral side, thereby absorbing the excessive axial displacement. At this time, the cause of the instability of the bellows 1 causing buckling due to pressure is as follows.
Since the inner guide ring 6 (6 ') and the outer guide ring 7 dissolve the buckling, buckling displacement is prevented. Also, with respect to excessive displacement in the axial direction Y and the axial direction Z, the bellows (upstream and downstream) on both sides of the inner guide ring 6 (6 ') are displaced at the same angle about the pin 10 as an axis. Absorbs excessive axial displacement. At this time, the cause of instability of the bellows 1 such that buckling occurs due to pressure is caused by the inner guide ring 6 (6 '),
Since the buckling displacement is prevented by the outer guide ring 7, buckling displacement is prevented.

[0015]

As can be seen from the above description, the bellows type expansion joint according to the present invention is provided with an inner guide ring whose outer peripheral surface bulges in an arc-shaped cross section on the intermediate outer peripheral side of the bellows. Opposite the outer guide ring, whose outer circumferential surface is depressed into an arcuate cross section on the outer circumferential side, protrudes parallel to the axis of the shaft from the pipes on both sides of the bellows toward the bellows side in a mutually circumferential direction. The arm is slidably held by a pin in a long hole in the longitudinal direction of the provided arm to constitute a three-axis excessive displacement absorbing mechanism. Excessive displacement is caused by the outer guide ring,
The inner guide ring moves and displaces the bellows, absorbing the excessive axial displacement. At the same time, the excessive displacement in the perpendicular direction Y and Z displaces the bellows on both sides of the inner guide ring at the same angle with the pin as the axis. Since the bellows instability factor, which absorbs the excessive axial displacement and causes buckling by pressure, is eliminated by the inner guide ring and the outer guide ring, buckling displacement is prevented. In addition, since a single bellows type expansion joint can simultaneously absorb excessive triaxial displacement and prevent buckling displacement due to pressure, a facility for absorbing excessive triaxial displacement (earthquake displacement, etc.). However, it is small in size, the installation is small and requires little effort, and maintenance is easy.

[Brief description of the drawings]

FIG. 1 is an upper half vertical sectional front view showing an embodiment of a single type of a bellows type expansion joint of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an upper half vertical sectional front view showing an embodiment of a universal type of a bellows type expansion joint of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is an upper half longitudinal sectional front view showing an embodiment of a double type of bellows type expansion joint of the present invention.

6 shows an embodiment of a swing type of the bellows type expansion joint of the present invention, in which a is an upper half vertical sectional front view, and b is a cross-sectional view taken along line CC of FIG.

FIG. 7 is an upper half vertical sectional front view showing an embodiment of a straight pipe pressure balance universal type of the bellows type expansion joint of the present invention.

FIG. 8 is an upper half vertical sectional front view showing an embodiment of a curved pipe pressure balance universal type of the bellows type expansion joint of the present invention.

FIG. 9 is a longitudinal sectional view of a main part showing a clearance between an inner guide ring and an outer guide ring of the three-axis excessive displacement absorbing mechanism in the bellows type expansion joint of the present invention.

FIG. 10 is a side sectional view showing a modification of the inner guide ring and the outer guide ring of the three-axis excessive displacement absorbing mechanism in the bellows type expansion joint of the present invention.

FIG. 11 is an upper half vertical sectional front view showing an embodiment of the bellows type expansion joint of the present invention for a high pressure type of universal type.

FIG. 12 is a longitudinal sectional view of a main part showing a modification of the inner guide ring in the bellows type expansion joint of FIG. 12;

FIG. 13 is an upper half longitudinal sectional front view showing a basic configuration of a conventional bellows type expansion joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bellows 2 End pipe 3 Post flange 4 Stay bolt 5 Sleeve 6, 6 'Inner guide ring 6a Outer peripheral surface of inner guide ring 7 Outer guide ring 7a Inner peripheral surface of outer guide ring 8, 14 Arm 9, 15 Slot 10 Pin DESCRIPTION OF SYMBOLS 11 Washer 12 Intermediate pipe 13 Flange of intermediate pipe 20 Projecting surface 23 Reinforcement ring L-axis center line C Clearance

Claims (8)

[Claims] 1. A simple type, a double type, a universal type, a swing type, a straight pipe pressure balance universal type, and a curved pipe pressure having a basic structure for holding pipes connected by bellows within a certain interval by stay bolts. In various types of bellows type expansion joints of balance universal type,
An inner guide ring whose outer peripheral surface bulges in an arcuate cross section is provided on the intermediate outer peripheral side of the bellows, and an outer guide ring whose inner peripheral surface is depressed in an arcuate cross section on the outer peripheral side opposite to the inner guide ring. At the position displaced in the circumferential direction from the pipes on both sides of the bellows to the bellows side, and slidably held by pins in the long holes in the longitudinal direction of the arm protruding parallel to the shaft center line. Bellows type expansion joint. 2. The bellows type expansion joint according to claim 1, wherein a friction reducing treatment is applied to an outer peripheral surface of the inner guide ring and an inner peripheral surface of the outer guide ring. Telescopic fittings. 3. The bellows type expansion joint according to claim 1, wherein a predetermined clearance is provided between an outer peripheral surface of the inner guide ring and an inner peripheral surface of the outer guide ring. Features bellows type expansion joint. 4. The bellows type expansion joint according to claim 1, wherein a guide surface on an outer periphery of the inner guide ring is divided into a plurality of projecting surfaces. Type expansion joint. 5. The bellows type expansion joint according to claim 1, wherein the inner guide ring itself is divided in the circumferential direction. 6. The bellows type expansion joint according to claim 1, wherein the outer guide ring is divided in a circumferential direction. 7. The bellows type expansion joint according to any one of claims 1 to 6, wherein a valley on an outer peripheral side of the bellows has:
A bellows-type expansion / contraction pipe joint having a reinforcing ring mounted thereon. 8. The bellows type expansion joint according to claim 7, wherein the inner guide ring increases an outer diameter of the adjacent reinforcing ring and bends an outer peripheral surface of the adjacent reinforcing ring into an arc-shaped cross section. A bellows type expansion joint characterized by the following.