JP2000257767A - Joint for pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint for a pipe capable of holding sealing performance for a long period of time without applying a load on a rubber ring more than required. SOLUTION: This joint has a housing 1 to cover a circumference of pipe ends of two pipes 7, 7 and a rubber ring 2 for sealing provided on the inside of this housing 1. In this case, a collar part 4 is provided on an overall periphery of an outer edge part of the housing 1. Consequently, a bending load and an offset loading load are not applied on the tube end part (rubber ring part) 2 at the time of piping, after piping and at the time of operation by adhering the collar part 4 on a tube outer peripheral overall surface at the time of setting completion. The load applied on the tube end part is all received by the collar part 4 of the housing, and it is possible to mechanically (automatically) restrain bending, sagging, etc., after setting. A joint for heat resisting piping requires a function to absorb expansion and contraction due to a temperature difference of a tube, but, as movement of the tube in the axial direction is not restricted, it is possible to absorb them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for connecting pipes, and more particularly to a joint for a pipe with a function of suppressing the bending, rotation, and misalignment loading functions of a joint, and suppressing the eccentricity (displacement absorption) function when a plurality of pipes are used. About.

[0002]

2. Description of the Related Art In the case of a conventional joint for pipes, in the case of a C-shaped joint 10 shown in FIG. 4, a C-shaped iron wire ring 12 is welded to a predetermined position of a pipe end of two pipes 11 and a rubber ring 13 is attached to both pipe ends. The C-type ring 12 is formed by inserting the C-shaped ring 12 into the housing 14.
The seal has a structure in which the rubber ring 13 fulfills its function by tightening the bolt and nut 15 around the groove circumference.

[0003] Since the C-type joint 10 is based on the sealing principle of a U-shaped washer (automatic seal), the two pipes 11 to be connected can obtain a stable airtight effect against movement within the function range of the joint. . As shown in FIG. 5, the width of the housing is designed to be larger than the engaging width, and this clearance (dimension E) expands and contracts, bends,
It is a point that absorbs deflection (displacement absorption) and rotation.
This will be specifically described.

(1) Expansion and contraction (see FIG. 6 (a)) The clearance can take a maximum E dimension as a whole, and when the clearance at the pipe end is set to 0, the contraction of the pipe equal to the E dimension is absorbed. When the clearance at the pipe end is set at the maximum E dimension, the same elongation of the pipe as the E dimension is absorbed.
In general, when the expansion and contraction of a pipe is absorbed by a joint, a pipe is determined by determining a set E dimension based on a temperature difference during use and a temperature difference during piping to absorb expansion and contraction of the pipe. The expansion / contraction amount E of the pipe is obtained by the following equation. E = L (tube length) × α (linear expansion coefficient) × t (temperature difference) The linear expansion coefficient of iron is 1.2 × 10 ⁵

(2) Bending (See FIG. 6 (b)) If the clearance at the pipe end is 0 on one side and E on one side, the pipe bends, and the amount θ is the triangle between the pipe outer diameter (0, D) and the E dimension. Determined by a function. sin θ = E / (OD)

(3) Eccentricity (see FIG. 6C) Eccentricity cannot be absorbed by one joint.
As shown in FIG. 6C, two joints are used in combination, and the eccentricity is absorbed by the bending of the joint and the pipe length. Eccentricity δ = L · sin θ

(4) Rotation (See FIG. 6 (d)) Since only the rubber ring is in contact with the tube, rotation is possible. 360 ° pipe with high sealing performance of rubber ring
There is no leakage even when rotated, and it can be used as a pipe for absorbing interlayer displacement and uneven settlement using an elbow pipe. The above is the basic structure and function of this type of joint.

[0008]

The functions of this type of pipe joint have been adopted and spread in many industries as a flexible piping method. However, depending on the purpose of the piping and the piping conditions, the above-described functions may act in reverse to cause instability.

Heat-resistant pipes such as hot water supply, hot water, and cold / hot water pipes in building equipment pipes are used. The eccentric absorption function of the joints caused by bending and multiple uses is deformed and deteriorated by heat when the rubber ring is displaced and receives heat. This may result in leakage. All stresses and loads are applied to the piping at the time of piping, after piping, and during operation. Even in such a case, the rubber ring must be kept in a shape, elasticity, and dimensionally sealable state so as to meet any conditions.

The problem to be solved by the present invention is
An object of the present invention is to provide a pipe joint that does not apply a load to a rubber ring more than necessary and can maintain sealing performance for a long period of time.

[0011]

In order to solve the above-mentioned problems, in a pipe joint having a housing that covers the periphery of the pipe ends of two pipes, and a sealing rubber ring provided inside the housing, A flange is provided on the entire outer periphery of the housing.

[0012]

Embodiments of the present invention will be described below with reference to embodiments shown in the drawings. 1A and 1B show a configuration of a C-type joint according to a first embodiment of the present invention, wherein FIG. 1A is a sectional view, FIG. 1B is a front view, and FIG. 1C is a bottom view. In these figures, 1 is a housing, 2 is a rubber ring for sealing, 3 is a C-shaped iron wire ring welded to a pipe end of a pipe 7, 4 is a flange provided on the entire outer periphery of the housing, and 5 is a tightening member. The bolt 6 is a nut.

As described above, in this embodiment, the flanges 4 are integrally formed around the outer edges of both sides of the housing 1. Collar 4
The inner diameter of the tube is approximately the same as the outer diameter of the tube. When the bolts 5 and nuts 6 are tightened, the structure and dimensions of the inner surface of the tube are almost in close contact with the outer periphery of the tube when the tightening is completed.

As described above, the flange 4 is provided on the entire outer periphery of the housing 1 and is brought into close contact with the entire outer periphery of the pipe 7 when the setting is completed, whereby the rubber ring 2 at the pipe end is bent at the time of piping, after piping, and at the time of operation. Load and misaligned load are not applied. All of the above-mentioned load applied to the pipe end is received by the flange 4 of the housing 1, and after setting, it is a mechanism capable of mechanically (automatically) suppressing bending and drooping. A joint for a heat-resistant pipe must have a function of absorbing expansion and contraction due to a temperature difference between the pipes. However, in the present invention, the movement of the pipe in the axial direction is not restricted, and therefore, it can be absorbed.

In addition to the C-type joint shown in FIG. 1, the G-type joint shown in FIG. 2 and the S-type joint shown in FIG. Can be implemented.
Incidentally, the G-type joint shown in FIG. 2 has a groove 7 formed in the pipe 7 so as to have the same housing retaining function as the C-type iron wire ring 3 of the C-type joint shown in FIG. 1. The S-type joint shown in FIG. A collar 9 is welded to the end of the tube to provide a housing retaining function similar to that of the C-shaped iron wire ring 3 of the C-shaped joint in FIG.

[0016]

As described above, according to the present invention, the following effects can be obtained. (1) A flange is provided around the entire outer edge of the housing, and when the setting is completed, the flange is brought into close contact with the entire outer periphery of the pipe. Does not join. All the load applied to the pipe end is received by the flange of the housing, and after setting, it can be mechanically (automatically) bent and droop can be suppressed. (2) A joint for a heat-resistant pipe must have a function of absorbing expansion and contraction caused by a temperature difference between the pipes. However, the present invention does not restrict the movement of the pipe in the axial direction. (3) By bringing both ends of the outer edge of the housing into close contact with the outer periphery of the pipe, it is possible to mechanically (automatically) suppress the stress and load for plastically deforming the most important rubber ring in the heat-resistant pipe. (4) The present invention also has a cost, a merit, and an effect that can significantly reduce the number of fixing brackets, suspensions, and support brackets attached to the piping from the structural point of view.

[Brief description of the drawings]

FIGS. 1A and 1B show a configuration of a C-shaped joint according to a first embodiment of the present invention, wherein FIG. 1A is a sectional view, FIG. 1B is a front view, and FIG.

FIG. 2 is a cross-sectional view illustrating a configuration of a G-type joint according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of an S-type joint according to another embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view showing a configuration of a conventional C-shaped joint.

FIG. 5 is a sectional view of a conventional C-shaped joint.

FIG. 6 is a diagram for explaining a function of a C-shaped joint.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Housing, 2 rubber ring for sealing, 3 C type iron wire ring, 4 flanges, 5 bolts for tightening, 6 nuts, 7 pipes, 8 grooves, 9 collars

Claims (1)

[Claims] 1. A pipe joint having a housing that covers the periphery of pipe ends of two pipes, and a sealing rubber ring provided inside the housing, wherein a flange portion is provided on the entire outer periphery of the housing. A joint for a pipe, characterized in that: