JPH0654152B2 - Angular displacement expansion joint - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pipe joint in which pipes are connected by bellows, and the ends of the pipes are joined by hinges so that the expansion and contraction of the pipes can be controlled by the hinges. Regarding an angular displacement expansion joint that absorbs by displacement, more specifically, the angular displacement expansion and contraction with an anti-vibration mechanism that absorbs gentle displacement to prevent excessive deformation and sudden deformation Regarding pipe fittings.

(Prior Art) An expansion joint is provided at a connecting portion of a pipe in order to absorb expansion caused by thermal expansion of each portion.

Expansion joints connect the ends of the pipes with bellows,
This generally absorbs expansion and contraction of the end of the pipe.

Such expansion pipe joints are classified into axial displacement pipe joints and angular displacement pipe joints according to the type of expansion and contraction mechanism using bellows.

Axial displacement type expansion joint is disclosed in JP-A-58-134295.
As can be seen in the publication, the end of one pipe is inserted into the end of the other pipe, and the ends of both pipes are connected by a bellows, and the relative displacement between the pipes due to thermal expansion is It is absorbed by the movement in the axial direction.

Also, the angular displacement type expansion joint is for connecting the ends of the pipe with an elastic part such as a bellows and an angular displacement part such as a hinge.
The expansion / contraction portion and the angular displacement portion absorb displacement caused by relative thermal expansion between the pipes and displacement caused by sudden vibration such as an earthquake.

An example of a conventionally known angular displacement type expansion joint will be described below with reference to FIG.

FIG. 4 (a) shows the angular displacement type expansion joint 1, and the state of FIG. 4 (a) shows a state where thermal expansion is not performed (normal installation state). In the figure, reference numeral 4 is a bellows which is a stretchable portion, and reference numeral 5 is a hinge portion which causes the bellows 4 to be angularly displaced, not axially displaced,
Reference numeral 13 is a stopper which is a mechanism for preventing excessive deformation of the bellows 4, and reference numeral 2 is a pipe connecting portion for connecting pipes (not shown).

Now, when the pipe thermally expands, as shown in FIG. 4 (b),
The hinge 5 is angularly displaced and absorbs its thermal expansion. The bellows 4 absorbs the angular displacement of the hinge portion 5.

However, if the hinge 5 is excessively angularly displaced, the bellows 4
May be damaged. Therefore, as shown in FIG. 4 (c), if the hinge 5 is excessively angularly displaced, the stopper 13
This prevents the bellows 4 from being excessively deformed by colliding with each other.

(Problems to be Solved by the Invention) However, the above-mentioned conventional techniques have the following problems.

Generally, the piping system is connected to a device that generates vibration, such as a pump (not shown). In the case of such a piping system,
Large vibration acts on the angular displacement expansion joint 1. Further, when a large earthquake occurs, a large dynamic load acts on the angular displacement expansion joint 1.

Then, as shown in FIG. 4 (d), the bellows 4 of the angular displacement type expansion joint 1 is repeatedly deformed or the stopper 13 collides violently and repeatedly, and a high impact force is generated. The displacement type expansion joint 1 may be damaged in various parts, resulting in a decrease in strength of the bellows and collision parts.

On the other hand, in order to prevent the repeated deformation of the bellows 4 and the like and the collision of the stopper 13 and the like when the dynamic load is applied as described above, it is not shown between the front and rear portions of the angular displacement expansion joint 1 and the wall and other pipes. It is known to interpose a support member.

However, in the case of interposing this support member, a wall for fixing one end of the support member and the like must be located nearby, which poses a great limitation in piping design, and there is an inconvenience that the number of piping works increases.

Furthermore, in the axial displacement type expansion joint, a structure in which a damper is provided around the bellows is also known. (See JP-A-58-134295) However, in the axial displacement type expansion joint provided with the known damper, even if the damper can absorb an excessive dynamic load due to an earthquake or the like, Since there is no stopper for stopping an excessive static load (excessive displacement) due to a large difference in thermal expansion, the bellows may be damaged when an excessive static load is applied.

Therefore, an object of the present invention is to improve the above-mentioned drawbacks, provide the angular displacement type expansion pipe joint provided with a vibration damping mechanism for absorbing a gentle displacement, preventing an excessive displacement and preventing an abrupt displacement. There is.

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized by the following configurations.

That is, both ends of the pipe are connected by bellows, and both ends of the pipe are connected by a hinge mechanism so as to be angularly displaced so that the difference in thermal expansion is absorbed by expansion and contraction of the bellows and angular displacement of the hinge. Type expansion joint, wherein a damper portion is attached in parallel in the axial direction of the angular displacement type expansion joint, and the damper portion has one body and the other body inserted into the one body. A mechanism that absorbs a gentle displacement and acts as a rigid body for abrupt displacement is provided between each body, and a stopper part that collides with the tip of one body and the root of the other body is provided. An angular displacement expansion joint that is provided.

(Operation) The operation of the present invention is as follows.

First, at the time of expansion and contraction due to normal thermal expansion, a gentle displacement due to the thermal expansion is performed by the mechanical portion that absorbs the gentle displacement of the damper portion, and the hinge is angularly displaced.

When the displacement is excessively gradual, the stopper portions of the damper portion collide with each other and are prevented.

In the case of an excessive displacement such as an earthquake, the damper part acts as a rigid body to prevent the excessive displacement.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in FIG. 1, the angular displacement type expansion joint 1 of the present embodiment has a front fixing portion 3 made of a rigid body provided in the pipe connecting portion 2.
A bellows 4 that receives expansion and contraction is interposed between a and the rear fixing portion 3b. Further, in order to allow the angular displacement type expansion joint 1 to be angularly displaced, a front fixing portion 3a and a rear fixing portion 3b are provided.
A hinge portion 5 for guiding the guide is provided between the two. A pipe (not shown) is connected to the pipe connecting portion 2. In the illustrated state of FIG. 1, the hinge portion 5 is not displaced, and the angular displacement type expansion joint 1 is in a normal state (installed state).

The configuration up to this point is the same as that of the known angular displacement expansion joint, but in the present embodiment, the bracket 6 is provided on the front fixing portion 3a and the rear fixing portion 3b. A plurality of dampers 7 are arranged in parallel in the axial direction of the angular displacement type expansion joint 1. The damper 7 absorbs a gentle displacement as if it were an elastic body, but acts as a rigid body for a sudden displacement and functions as a stopper for an excessive gentle displacement.

An example of the damper 7 will be described with reference to FIG.

The damper 7 according to this embodiment is a known mechanical damper, in which two bodies 8a and 8b are provided so as to face each other, and a ball bearing 9 is provided at an end portion of both the bodies 8a and 8b. Universal mounting part is provided,
The ball bearing 9 is connected to the bracket 6.
A ball screw 10 is rotatably and immovably provided in the axial direction on one body 8a.
A ball nut 11 that engages with is fixed to the other body 8b.

The ball bearing 9 of the mounting portion converts loads in various directions into loads in the axial direction of the damper 7, and the axial load is a gentle static load such as thermal expansion (here, accompanied by gentle displacement). In the case of a load and a static load), the ball screw 10 rotates to absorb the axial displacement, but the axial load is a sudden dynamic load such as an earthquake or vibration (abrupt displacement here). In the case of (a load accompanied by is referred to as a dynamic load), the ball screw 10 does not rotate, and the axial displacement of the damper 7 is prevented.

The operation of the embodiment configured as described above is shown in FIG.
This will be described with reference to (b).

Now, when the pipe thermally expands, as shown in FIG.
One of the dampers 7 receives a tensile load and extends, and the other damper 7 receives a compressive load and contracts so that the hinge portion 5 is displaced. When a static load accompanied by a gentle displacement such as thermal expansion is applied, the ball screw 10 of the damper 7 gently rotates and is relatively displaced between the ball screw 11 and the ball nut 11.

The damper 7 also has a built-in stopper function. That is, the projecting end of one body 8a is the front stopper 3A, and the root of the other body 8b is the rear stopper 3B. The front stopper 3A and the rear stopper 3B are an excessive displacement preventing mechanism for preventing the excessive displacement of the hinge 5 by maximally expanding (or shortening) like the known stopper (reference numeral 13 in FIG. 4). Function. The maximum displacement amount is set by appropriately setting the stroke H in FIG.

As described above, with respect to the gradual expansion and contraction, when the large displacement acts on the angular displacement expansion joint 1, or when a large earthquake occurs, the angular displacement expansion joint 1 may be suddenly displaced. When a dynamic load is applied, the ball screw 10 of the damper 7 does not rotate and displacement of the damper 7 is blocked, so that the dynamic load is applied to each damper 7 as shown in FIG. 3 (b). It is fixed to the previous state. Therefore, the hinge 5 and the bellows 4 are repeatedly deformed, and the collision between the front stopper portion 3a and the rear stopper 3 is prevented.

The above is one embodiment of the present invention, and the present invention is not limited to the above embodiment. For example, the damper is not limited to the ball screw type damper, but includes, for example, a liquid type damper that has a vibration damping effect by the liquid passing through the orifice. Also, the number of dampers is appropriately determined. Furthermore, the portion that expands and contracts is not limited to the bellows, but includes, for example, a rubber tube. Further, the mechanism for guiding each displacement is not limited to the hinge type, and includes, for example, a mechanism for causing angular displacement by another link mechanism.

The field of application of the expansion joint with the vibration isolation mechanism of the present invention covers a wide range from general industries to nuclear power generation facilities requiring earthquake resistance.

(Advantages of the Invention) In the angular displacement expansion joint according to the present invention, the damper provided in parallel in the axial direction of the joint follows the displacement of the angular displacement expansion joint during static load action such as thermal expansion of the pipe. At the same time, the damper is extended or shortened as much as possible to prevent excessive displacement of the expansion and contraction part.However, when a dynamic load such as vibration is applied, the damper is fixed in the state just before the dynamic load is applied, so the bellows is repeatedly displaced. Also, the front and rear parts of the joint are prevented from colliding, and damage to the equipment is prevented.

Further, it is not necessary to interpose a supporting member between the joint and the wall, the degree of freedom in piping design is improved, and piping work is facilitated.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing an example of the damper provided in the above embodiment. 3 (a) and 3 (b) are operation state diagrams of the embodiment shown in FIG. FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D are schematic diagrams for explaining the prior art. 1: Angular displacement expansion joint, 2: Pipe connection part 3a: Stopper, 3b: Stopper, 4: Bellows,
5: Hinge, 7: Damper, 8a: One body, 8
b: other body, 3A: front stopper, 3B: rear stopper

Claims (1)

[Claims] 1. The pipes are connected at both ends by bellows, and both ends of the pipe are connected by a hinge mechanism so as to be angularly displaced so that the difference in thermal expansion is absorbed by expansion and contraction of the bellows and angular displacement of the hinge. In the angular displacement type expansion joint, the damper portion is attached in parallel in the axial direction of the angular displacement type expansion joint, and the damper portion includes one body and the other body inserted into the one body. It has a mechanism that absorbs a gradual displacement and acts as a rigid body against abrupt displacement between each body, and collides with the tip of one body and the root of the other body. An angular displacement expansion joint that is equipped with a stopper.