JPS61236990A - Bellows type expansion pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a bellows-type expansion pipe joint that absorbs relative displacement of connected pipes, and particularly to a simple and high-strength bellows-type expansion pipe joint.

[Technical background of the invention II]

For example, in piping systems for steam, air, gas, water, oil, etc., the connected pipes may undergo relative displacement due to ms changes or earthquakes, etc.
There are some parts that vibrate due to the operation of related equipment. O-shaped expansion pipe joints are used as pipe joints and joints for absorbing such displacements, vibrations, etc.

FIG. 4 shows an example of a conventional general bellows type expansion pipe joint. A connecting member 4 consisting of a short tube 2 and seven flanges 3 is connected to both ends of a joint body 1 consisting of a cylindrical bellows formed in an accordion shape.

The joint body 1 is made of a thin plate-like resin or the like, and can absorb a certain range of displacement occurring in the connected pipes. but,
In order to maintain a predetermined displacement absorption capacity, the wall thickness of the joint body 1 cannot be made excessively large, which prevents shocks, external loads,
Or, it receives a certain level of strength against high internal pressure, etc. Therefore, for connections to high-temperature and high-pressure pipes or to areas where external loads are applied, it is common to provide external reinforcement to the joint body made of bellows.

FIG. 5 shows a bell-shaped expansion pipe joint having a conventionally known reinforcing structure. In addition, the one in the same figure is a double type,
That is, a pair of joint bodies 11 are coaxially connected by a connector 12, and a connecting member 13 is attached to the open end of each joint body 11.
is provided.

The connector 12 and each connecting member 13 are each composed of a short pipe 14, 15 and a flange 16 provided at each end thereof, and each of the seven flanges 16 is arranged to sandwich each joint body 11. Seven flanges 16 sandwiching each joint body 11 are connected by stays 17 with a certain amount of play in the axial direction, so that the flanges 16 and stays 17 bear the load when the joint body 11 expands and contracts by more than a certain amount. It has become. Incidentally, reference numeral 18 is a set bolt that positions the flange 16 until installation. Further, 19 is a support for supporting the connector 12,
Set to any height.

The bellows-type expansion pipe joint shown in FIG. 5 further includes a plurality of adjustment rings 20 covering the outer periphery of the joint body 11.

The adjustment ring 20 is made of a heat-resistant elastic material, and consists of a protrusion 20a that fits into each valley on the outer periphery of the joint body 11 and a cylindrical part 20b that covers each peak. Mounted closely together in the axial direction.

With this configuration, the load due to the external force in the axial direction acting on the joint body 11 is received by the stay 17, and the internal pressure is received by the adjustment ring 20, and high strength is exhibited for pipe connections that are subjected to high temperature and pressure. are doing.

(Problems with the Background Art) However, in the reinforced structure shown in FIG. Displacement can be absorbed within a certain range, but displacement in the radial direction, that is, vertically or horizontally, cannot be absorbed.For this reason, so-called uneven settlements, such as pipe connections between different buildings such as power plants or tank piping, cannot be absorbed. It is unsuitable for use in certain parts.In addition, it has a large number of parts, has a complicated configuration, requires time and effort to manufacture, and is expensive, making it difficult to use it in areas other than those with special requirements. be.

Therefore, the above-mentioned reinforcement structure has a problem in that its scope of application is limited due to the effect of displacement and cost.

For this reason, in areas where it is necessary to absorb displacement in a direction other than the axial direction under high temperature and high pressure conditions, bellows-type expansion joints are not used, and the piping itself has a large bend to absorb displacement. That is the reality. With this method, the amount of piping increases, and the space for accommodating the piping must also be widened, resulting in problems such as increased costs.

[Purpose of the invention]

The present invention was made in view of these circumstances, and has the ability to absorb displacement in directions other than the axial direction, has a simple structure, is easy to manufacture, and can be manufactured at low cost, and has sufficient resistance against internal and external loads, shocks, etc. It is an object of the present invention to provide a peice type expansion pipe joint that has strength and can be applied over a wide range of areas.

(Summary of the Invention) In order to achieve the above object, a bellows-type expansion pipe joint according to the present invention includes a joint body made of a bellows-shaped bellows having spiral folds, and valleys of the folds on the outer periphery of the joint body. The protective member has a coil-shaped protective member wound around the protective member, and the protective member is characterized in that a shock absorbing material is coated on the outer periphery of a stretchable elastic wire.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3.

The joint body 21 is made of an accordion-like bellows, and the pleats 22 are formed in a spiral shape. Seven flange-shaped connecting members 23 are connected to both ends of this joint body 21. A coil-shaped protection member 24 is wound around the troughs 22a of the pleats 22 on the outer periphery of the joint body 21, and both ends of the protection member 24 are fixed to the mounting holes 25 on the opposing surfaces of each connection member 23. There is.

The protective member 24 includes an elastic wire 24a made of a mesh spring and a shock absorbing material 2 attached to the elastic wire 24a.
It consists of 4b.

The mesh spring as the elastic wire 24a is made by knitting high tensile strength wire into a stockinette shape, bending it into a corrugated sheet shape, and then compressing it in a mold to form a sliver shape with a predetermined density. It is something. Since the density of the elastic wire 24a made of this mesh spring increases as the load such as external pressure increases, the elastic wire 24a does not bend linearly with respect to the load, but becomes a hard spring. In addition, since friction occurs between the wires due to the load, the load characteristics exhibit hysteresis and exhibit a large insulation effect against high-frequency microvibrations.

Further, the shock absorbing material 24b covering the elastic wire 24a is made of a flexible material such as synthetic resin or rubber, and is adhered in a tubular shape over the entire outer periphery of the elastic wire 24a. The shock absorbing material 24b smoothly covers the rough surface of the elastic wire 24a, making it possible to wrap the joint main body 21 made of bellows without causing damage, and also prevent Wi-Fi from the outside.
The effect of reducing the impact load by 1sv11 can be obtained.

According to the bellows-type expansion pipe joint according to the embodiment with such a configuration, the axial load on the joint body 21 due to relative displacement of the connected piping portion or the pressure of the internal fluid may be applied to the joint body 2
The radial load on 1 is applied to the trough 22 on the outer periphery of the joint body 21.
It is received by the coil-shaped protection member 24 wound around a, especially the elastic wire 24a that serves as the core. In this case, the elastic wire 24a is made of a mesh spring and exhibits a strong elastic resistance in accordance with the load in the axial and radial directions of the joint body 21 like a hard spring, so that it can reliably handle each load regardless of its directionality. It can be received and absorbed.

Further, when an impact load is applied, it can be absorbed by the deflection of the impact absorbing material 24b located between the joint body 21 made of a bell and the elastic wire 24a.

As a result, the load acting on the joint body 21 is reduced by the elastic wire 24.
Since the joint body 21, that is, the bellows itself does not need to be particularly strong, it is not necessary to add extra thickness. In addition, since the bellows is reinforced with a spiral elastic wire, there are no particular restrictions on the direction of displacement that can be absorbed, making it possible to apply it to locations where displacement occurs in the direction perpendicular to the axis, which was previously difficult. The range is expanded.

Furthermore, the number of parts is small, the structure is simple, manufacturing, installation, etc. can be easily performed, and the cost can be sufficiently reduced, so that the range of application can be expanded from this point of view as well.

In the above embodiment, a mesh spring is used as the elastic wire 24a, but this is the most preferable example that effectively utilizes its excellent vibration absorption ability and heat resistance, and even if it is made of a material other than a mesh spring, Of course, it can be applied to a variety of materials as long as it is highly heat resistant and flexible.

Further, in the embodiment, the joint body 21 and the protection member 2
Although the connecting member 22 that holds the 4 is made into a 7-lunge, the present invention is not limited to this, and can be appropriately modified into a small-diameter plate, a tubular member, or the like.

By adjusting the strength of the elastic wire 24a, it is possible to obtain various specifications corresponding to the usage conditions, so it is also possible to set standards and standardize the shape etc., and mass-produce the elastic wire 24a.

(Effects of the Invention) As described above, according to the bellows-type expansion pipe joint according to the present invention, the coiled protective member is wrapped around the trough of the outer periphery of the bellows body having spiral folds. It is also possible to absorb displacement in directions other than the axial direction, and it can be widely applied to pipe connections where loads in the direction perpendicular to the axis are applied, where conventional reinforcement structures cannot be used.

In addition, the number of parts is small and the configuration is simple, so it can be manufactured easily.
In addition to being easy to install and reducing costs, it does not require much surrounding space, and in this sense, the range of applications can be expanded.

Moreover, since the protective member has a shock absorbing material attached to the elastic wire, it can withstand internal pressure, -% load and impact load, and exhibits a strong effect in terms of strength.

[Brief explanation of drawings]

Fig. 1 is an overall cross-sectional view showing one embodiment of the present invention, Fig. 2 is an enlarged view showing a part of Fig. 1, Fig. 3 is a perspective view showing the structure of the protection member, and Fig. 4. 5 is a partially sectional front view showing a general example of a bellows type expansion pipe joint, and FIG. 5 is a partially sectional front view showing a conventional bellows type expansion pipe joint having a reinforcing structure. 21... Fitting body bellows), 22... Folds, 2
2a... Valley portion, 24... Protective member, 24a... Elastic wire, 24b... Shock absorbing material. Applicant's agent Hisashi Hatano Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A joint body consisting of an accordion-shaped bellows having spiral folds, and a coil-shaped protective member wound around the valleys of the folds on the outer periphery of the joint body, and this protective member is a bellows-type expansion pipe joint characterized by having a shock-absorbing material coated on the outer periphery of a stretchable elastic wire. 2. The bellows type expansion pipe joint according to claim 1, wherein the elastic wire is constituted by a mesh spring. 3. The bellows type expansion pipe joint according to claim 1, wherein the shock absorbing material is made of a flexible material such as synthetic resin or rubber, and is coated in a tubular shape over the entire outer periphery of the elastic wire.