JPH07269759A - Expansion pipe joint - Google Patents

Abstract

PURPOSE:To secure such an expansion joint as providing sufficient expansibility and strength in the pipe axial direction jointly. CONSTITUTION:This is an expansion pipe joint 1 provided with a tubular member 2 being formed with a connecting part 22 made up of capable of receiving, inserting and connecting free of expansion or contraction while being composed of forming a flange surface at both ends, a bellows 3 being installed in this tubular member 2 and formed into a bellows-form being free of expansion while made up of having a flange part 31 sticking close to the flange surface 21 installed around, and a regulating member 4 engaging in a gap with the flange surface 21 of the tubular member 2 and being made up so as to regulate an extending state of this tubular member 2, respectively.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is used for a piping line for hot springs or hot water, a hot water supply line for central heating equipment, or a plant pipe, and can absorb stress due to thermal expansion of the pipe, and in particular, internal pressure is applied. The present invention relates to a pipe joint used for piping.

[0002]

2. Description of the Related Art Generally, as a joint used for connecting pipes such as a hot spring or hot water pipe line, a hot water supply line of a central heating facility, or a plant pipe, an expansion pipe is used so as to cope with expansion and contraction due to heat. Joints are often used.

Conventionally, as the expansion pipe joint, a bellows bellows which is made expandable and contractible has a different radius of curvature between the inner surface and the outer surface (see Japanese Patent Laid-Open No. 60-222684). A structure in which a coil-shaped protective member is embedded in the valley (see Japanese Patent Laid-Open No. 61-236990) has been proposed.

[0004]

However, in the case of the above-mentioned conventional expansion joint, there is a problem that not only the pipe is stretched in the axial direction of the pipe due to expansion by heat but also expanded in the circumferential direction, resulting in insufficient strength. Will occur. Therefore, it is possible to increase the overall rigidity, but in this case, expansion and contraction in the axial direction of the pipe does not occur smoothly, and there is a problem that the pipe connected to this expansion joint bends first. Become.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an expansion joint having both sufficient elasticity in the pipe axis direction and strength.

[0006]

SUMMARY OF THE INVENTION An expansion joint according to the present invention for solving the above-mentioned problems is provided with a connecting portion which is insertably and expandably received and is connectable, and flange surfaces are formed at both ends. And a bellows which is provided in the tubular member and is formed into an expandable and contractible bellows, and at both ends of which a flange portion closely contacting the flange surface is provided, And a regulating member configured to engage between the flange surfaces of the cylindrical member to regulate the extended state of the tubular member.

[0007]

According to the present invention, since the bellows is provided in the tubular member, even if internal pressure is generated in the bellows,
The expanding force acting on the bellows is regulated by the tubular member and displaced by the stretching force. Further, this stretched state can be regulated by a regulation member, and even when the stretching force acts against this regulation and the internal pressure of the bellows increases,
The tubular member provided outside the bellows prevents expansion and destruction of the bellows. Furthermore, since the tubular member has a structurally different receiving and inserting state in contrast to a bellows that physically changes its shape and expands and contracts, it can be expanded and contracted smoothly following the expansion and contraction of the bellows. it can.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show the outline of the overall structure of the expansion joint 1, and FIG. 3 shows the construction of the expansion joint 1.

That is, the expansion joint 1 is made to be expandable and contractible, the bellows 3 provided inside the cylindrical member 2, and the cylindrical member 2 so that the expanded state thereof is maintained. The regulating member 4 for regulating is provided.

The tubular member 2 includes an insertion member 2a having a flange surface 21 formed at one end of a tubular main body 20, and a connection portion having the same structure as the insertion member 2a and having an enlarged diameter on the other end side. Two
2 is formed on the receiving member 2b. The tubular member 2 is configured such that the insertion member 2a can be received and inserted into the connection portion 22 of the receiving member 2b so that the mutual flange surfaces 21 are located at both ends. The length can be freely expanded and contracted by changing the receiving and inserting state by the connecting portion 22.

Needless to say, the material of the cylindrical member 2 thus formed has sufficient strength, but the material is not particularly limited. For example, it is preferable to use a material that does not rust, such as stainless steel. However, select the most suitable one according to the internal fluid and surrounding atmosphere. In the case of outdoors, it is better to consider weather resistance by ultraviolet rays. The dimensions and wall thickness are also appropriately determined in consideration of the stress generated from the inside and the corrosion allowance.

The bellows 3 is formed of a resin material or the like into an expandable and contractible bellows shape, and flange portions 31 are provided around both ends thereof. An annular ring 32 is embedded in each mountain portion 33 of the bellows 3 to ensure sufficient strength. Furthermore, the outer diameter of the bellows 3 is set so that it can be inserted into the tubular member 2.
The length is such that it can be expanded and contracted following the expansion and contraction of the tubular member 2. The bellows 3 is configured so that the flange portions 31 at both ends thereof are in close contact with the flange surface 21 of the tubular member 2 with an adhesive or the like in a state of being inserted into the tubular member 2.

The material of the bellows 3 is preferably ethylene propylene rubber (EPDM) or the like,
The material to be used is not particularly limited, and a material that has been examined for the fluid that will flow inside the bellows 3 and its usage conditions is used. In particular, in the case of a chemical solution, it is preferable to select it in consideration of corrosion resistance, and to line it with Teflon or the like if necessary. Further, the hardness, elasticity and wall thickness of the bellows 3 are selected so as to have physical properties and dimensions capable of absorbing the thermal expansion and contraction amount of the tubular body 5 to which the expansion pipe joint 1 is connected. Further, the material of the annular ring 32 embedded in the bellows 3 is not particularly limited as long as it has sufficient strength. For example, a fluid having a strong oxidizing property flows inside the bellows 3. In such a case, it is desirable to use a material such as stainless steel that is not corroded. Further, the size is selected such that it is embedded inside the bellows 3 and has sufficient strength to withstand the expanding force under the use conditions. Furthermore, it is desirable that the interface between the annular ring 32 and the bellows 3 has sufficient strength by a method such as adhesion.

In the present embodiment, the bellows 3 is reinforced by embedding the annular ring 32 in the bellows 3.
As shown in FIG. 4, the amplitude of the waveform on the outer surface of the bellows 3 is made larger than the amplitude of the waveform on the inner surface so that each peak portion 33 of the bellows 3 becomes thicker than each valley portion 34. May be

The regulating member 4 is made of a rod material, and a fastening nut 41 and a regulating nut 42 can be screwed on both ends thereof. This regulation member 4
Of the bolt holes 23 provided on the flange surface 21 of the tubular member 2 are inserted into every other three places, and the flange surfaces 21 are communicated with each other. Then, the regulating member 4 is fastened and fixed to the one flange surface 21 by the fastening nut 41. In addition, the restriction nut 42
Is fixed to the restriction member 4 with a proper restriction interval between the flange surface 21 and the other flange surface 21. Thereby, the regulation nut 42 regulates the movement of the flange surface 21, and regulates the expansion / contraction width of the tubular member 2 in accordance with the regulation interval range of the regulation nut 42. Further, the restriction nut 42 keeps the insertion and insertion state of the insertion member 2a and the reception member 2b forming the tubular member 2 from coming off. Therefore, as the regulating nut 42, a nylon-containing nut, a lock nut, or the like is used so that the screwing condition with the regulating member 4 becomes loose and the regulating interval does not change.

Although the restricting member 4 is provided in three of the six bolt holes 23 in this embodiment, the number of the restricting members 4 is not particularly limited to three, and the bolt holes provided in the flange surface 21 are not limited thereto. It is provided according to the number of 23. However, it is preferable to provide at least two locations.

In the expansion joint 1 thus constructed, the bolt nuts 6 are provided in the three bolt holes 23 of each flange surface 21 and fastened and fixed to the flange surface 51 of the pipe body 5. Also,
The above-described restriction member 4 is provided in the remaining three bolt holes 23. As a result, in the expansion joint 1, the flange surface 21 on one side (the receiving member 2b in this embodiment) is fastened and fixed at six points of the bolt nut 6 and the regulating member 4, and the other (the inserting member 2a in this embodiment). The flange surface 21 of the above is installed in a state of being fastened and fixed by the bolt nuts 6 at three locations. Further, the flange portion 31 of the bellows 3 has a flange surface 21 and a flange surface 51.
And plays a role of packing.

In the case where there is a fear of insufficient fixing force in fastening and fixing with the bolts and nuts 6 at three places, the bolt holes 23 may be increased and fastening and fixed so as not to buffer the regulating member 4. Further, in this construction state, the tubular member 2
Shall be installed at an intermediate position that allows expansion and contraction that can be applied both in the contracting direction and in the stretching direction.

According to this expansion joint 1, even when an internal pressure is generated in the bellows 3, the expanding force acting on the bellows 3 is restricted by the tubular member 2 and displaced to the drawing force.
On the other hand, the tubular member 2 is structurally changed in the receiving and inserting state following the extension of the bellows 3, and the expansion and contraction joint 1 as a whole can obtain a sufficiently and smoothly expanded and contracted state.

In this stretched state, the expansion / contraction width can be adjusted by regulating the receiving / inserting state of the tubular member 2 by the regulating member 4.

Further, when the stretching force acts against the regulation by the regulation member 4, the internal pressure of the bellows 3 is further increased. In this case, the bellows 3 is covered by the tubular member 2. Therefore, expansion and destruction of the bellows 3 can be prevented.

[0023]

As described above, according to the present invention, the expanding force acting on the bellows due to the increase in the internal pressure can be displaced into the axial stretching force, and the tubular member can receive the expanding force. Since it expands and contracts due to structural changes that change the inserted state, it is possible to perform smooth expansion and contraction following the expansion and contraction of the bellows, and it is possible to obtain sufficient expandability in the pipe axis direction as an expansion joint. .

Further, even when the internal pressure of the bellows is increased, expansion and destruction of the bellows can be prevented by the tubular member provided outside the bellows, so that sufficient expansion and contraction in the axial direction of the pipe is achieved. Together, they can obtain sufficient strength.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an outline of an overall configuration of an expansion joint.

FIG. 2 is a front view showing the outline of the overall configuration of the expansion joint.

FIG. 3 is a side view showing a state in which the expansion joint is connected to a pipe.

FIG. 4 is a partially enlarged sectional view showing another embodiment of the bellows.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Expansion joint 2 Tubular member 21 Flange surface 22 Connection part 3 Bellows 31 Collar part 4 Control member

Claims (1)

[Claims] 1. A tubular member having a connecting portion which is insertably and expandably received and is connectable, and flange surfaces are formed at both ends, and a tubular member which is provided in the tubular member and is expandable and contractible. A bellows, which is formed in a bellows shape and has a flange portion closely contacting the flange surface at both ends thereof, and a stretched state of the tubular member by engaging between the flange surfaces of the tubular member. An expansion joint, comprising: a regulating member adapted to regulate.