JPH08303679A - Piping vibration damping coupling - Google Patents

Abstract

PURPOSE: To simultaneously prevent transmission of vibration of a piping and transmission of pulsation of fluid to flow in the piping. CONSTITUTION: A movable orifice 4 connected to both pipings is interposed between both pipings 1a, 1b to be connected to each other through a vibrationproof supporting means (vibrationproof rubbers 2, 3 or a spring and a damper) so as not to be brought in direct-contact with both pipings. A bellows 9 is connected to one piping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe damping joint for preventing vibration of a pipe and propagation of pulsation of a fluid flowing in the pipe.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional pipe damping joint. In FIG. 4 (A), a bellows 9 is interposed between the pipes 1 and 1 and connected. FIG. 4 (B),
In (C), the pipes 1 and 1 are connected via the orifice 4. In general, a pump or the like is usually provided in the piping system, and the pump or the like causes vibration in the pipe 1 to propagate, and pulsation also occurs in the fluid flowing in the pipe 1 to propagate. What is shown in FIG. 4 (A) is a bellows 9
The easiness of deformation prevents the vibration of one pipe 1 from propagating to the other pipe 1. 4B and 4C prevent the pulsation of the fluid flowing in the pipe 1 from propagating to the downstream side due to the resistance when passing through the orifice hole 4h.

[0003]

Although the conventional pipe damping joint is as described above, the bellows 9 shown in FIG. 4 (A) can prevent the vibration of the pipe 1 from propagating.
The prevention of pulsation propagation of the fluid flowing therein is insufficient. Further, in the case of using the orifice 4 shown in FIGS. 4B and 4C, the propagation of the pulsation of the fluid can be prevented, but the propagation of the vibration of the pipe 1 itself cannot be prevented. There were challenges.

The present invention has been made in order to solve the above problems, and an object of the present invention is to obtain a vibration damping joint for a pipe, which simultaneously prevents the propagation of vibration of the pipe and the propagation of pulsation of the fluid flowing in the pipe.

[0005]

A pipe damping joint according to the present invention has a movable orifice connected between both pipes to be connected with vibration-proof support means so as not to come into direct contact with the both pipes. Intervening. Further, the pipe damping joint according to the present invention has a movable orifice connected to both pipes with vibration-proof support means interposed between the two pipes to be connected so as not to come into direct contact with the both pipes. It is provided by connecting a bellows type joint.
The anti-vibration support means is made of anti-vibration rubber. The anti-vibration support means is composed of a spring and a damper.

[0006]

In the pipe damping joint according to the present invention, since the movable orifice connected by the vibration-proof support means is interposed so as not to come into direct contact with both pipes, the vibration of one pipe is
The vibration-proof support means absorbs and blocks the vibration and does not transmit it to the other pipe. In addition, the movable orifice resists the pulsation of the fluid passing therethrough and smoothes the pulsation.
When vibration occurs in the movable orifice due to the pulsation of the fluid, the vibration isolation support means absorbs the vibration of the movable orifice. Further, when the bellows type joint is provided together with the movable orifice, the bellows prevents the vibration of the pipe from propagating due to its easiness of deformation. This further improves the vibration damping performance. Further, if the vibration-proof support means is made of a vibration-proof rubber, the above-described vibration-damping effect can be obtained with a simple structure. Further, if the vibration-proof support means is a spring and a damper, the spring coefficient and the damping coefficient, which are the parameters of the vibration-damping operation, can be set arbitrarily, and the above-mentioned vibration-damping effect can be maximized.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing a pipe damping joint according to an embodiment of the present invention. In FIG. 1, 1a and 1b are pipes, 2 and 3 are vibration-proof rubbers, 4 is a movable orifice, 5 and 6 are orifice support pipes, and 9 is a bellows.

As shown in FIG. 1, the movable orifice 4 is
A plate portion 4p, which is a disk having an orifice hole 4h,
An annular portion 4 formed on the outer peripheral portion of the plate portion 4p so as to extend in both sides in the vertical direction on the surface of the plate portion 4p with a constant width, and to make one round in an annular shape
It is a shape composed of r and r. The inner peripheral surface on the left side of the annular portion 4r in the drawing is connected to the outer peripheral surface of the orifice support pipe 5 via the vibration isolating rubber 2, and the inner peripheral surface on the right side of the annular portion 4r in the figure via the vibration isolating rubber 3 6 is connected to the outer peripheral surface. The anti-vibration rubbers 2 and 3 have an annular shape, the outer peripheral surfaces of the anti-vibration rubbers 2 and 3 are in close contact with the inner peripheral surface of the annular portion 4r of the movable orifice 4, and the inner peripheral surfaces of the anti-vibration rubbers 2 and 3 support the orifice. It is formed so as to be in close contact with the outer peripheral surfaces of the tubes 5 and 6, and they are attached by being firmly adhered with an adhesive. The orifice support tubes 5 and 6 have a shape surrounding the annular portion 4r of the orifice 4 and a sufficient gap is provided between the orifice support tubes 5 and 6 so that the orifice support tubes 5 and 6 do not come into contact with each other even if they are deformed. The orifice support tubes 5 and 6 are also formed so as not to come into direct contact with each other. The materials of the vibration-proof rubbers 2 and 3 have required vibration-proof properties (elasticity, damping properties, etc.), as well as synthetic rubbers that physically and chemically have the required performance with respect to the fluid flowing in the pipe 1. Is made of.

As shown in FIG. 1, the orifice support pipe 6 is connected to the pipe 1b by a flange joint or the like, and the orifice support pipe 5 has a bellows 9 and is connected to the pipe 1a by a flange joint or the like. In the configuration having the bellows 9 as shown in FIG. 1, the flanges on the outer sides of the orifice support tubes 5 and 6 may be clamped by bolts with a sealing material sandwiched therebetween. As will be described later, the movable orifice according to the present invention has a large pulsation reducing effect, but generally, if the diameter of the orifice hole 4h is large, the performance of suppressing the fluid pulsation is low, and if it is small, the flow resistance of the fluid increases, so Considering these points, the size is determined appropriately.

Next, the operation of the embodiment shown in FIG. 1 will be described. As shown in FIG. 1, when a fluid, not shown, is circulated in the pipe 1 connected and connected by the pipe damping joint, vibration is propagated from the pump to the pipe 1.
For example, if the pipe 1b is on the pump side, the pipe 1b
The vibrations that have propagated to the nozzles try to propagate from the orifice support pipe 6 to the orifice 4 via the vibration isolating rubber 3, but the elastic coefficient and the natural frequency of the vibration isolating rubber 3 are not Since it is significantly lower than that of the other vibrations, the propagated vibration cannot propagate through the anti-vibration rubber 3. On the contrary, when the pipe 1a is on the pump side, the vibration that has propagated to the pipe 1a is absorbed by the deformability of the bellows 9 and does not propagate to the orifice support pipe 5. Although not shown, the bellows 9 may be omitted and the orifice support tube 5 may have the same structure as the orifice support tube 6. in this case,
The vibration propagating from the pipe 1a to the orifice support pipe 5 is absorbed by the vibration isolating rubber 2 in the same manner as described above.

Further, in FIG. 1, pulsation may propagate from the pump or the like to the fluid flowing in the pipe 1. In general,
A pressure difference that is proportional to the square of the flow rate or the flow velocity occurs between the upstream side and the downstream side of the orifice 4 of the fluid passing through the orifice hole 4h. That is, a resistance proportional to the square of the flow velocity is generated. Therefore, when the fluid accompanied by pulsation passes through the orifice hole 4h, the resistance is large in the portion where the pulsation peak passes through at high speed, and the resistance is small in the portion where the pulsation valley passes through at low speed. Is smoothed. Further, the vibration generated in the orifice 4 due to the pulsation is absorbed by the vibration damping rubbers 2 and 3.

Next, the embodiment shown in FIG. 2 will be described. In the embodiment shown in FIG. 2, the orifice 4 is supported by the spring 7 and the damper 8. It may be considered that the functions of the anti-vibration rubbers 2 and 3 shown in FIG. 1 are decomposed into the spring 7 and the damper 8 to be symbolized. Also in the pipe damping joint shown in FIG. 2, similarly to the above, the orifice 4 smoothes the pulsation of the fluid flowing in the pipe 1 by the flow velocity squared resistance of the orifice hole 4h. The damper 8 absorbs the vibration energy generated in the orifice 4.

In FIG. 2, in particular, the vibration constant of the vibration system consisting of the mass of the orifice 4 plus the additional mass of the fluid, the spring constant of the spring 7 and the damping constant of the damper 8 is matched with the frequency component of the fluid pulsation. If this is selected, this vibration system can be brought close to a pulsation and resonance state. For example, if the vibration due to pulsation becomes 5 times as close to the resonance state, the pulsation reducing effect will be 25 times as high as 5 squared, and the pulsation reducing effect will be 25 times that of the fixed orifice.

Next, the graph showing the pulsation reducing effect shown in FIG. 3 will be described. FIG. 3 shows the orifice hole diameter d on the abscissa, the pulsation reduction effect e on the ordinate, and the operating loss L due to the line resistance. First, if the orifice hole diameter is d0 (operating loss is L0), the pulsation reduction effect is e1 for the fixed orifice and e2 for the movable orifice, and the pulsation reduction effect is significantly increased. Next, the same pulsation reduction effect e0
In the fixed orifice, the orifice hole diameter must be reduced to d1 and the operating loss is increased to L1. On the other hand, in the movable orifice, the orifice hole diameter is as large as d2 and the operating loss becomes L2, and the operating loss becomes extremely small. That is, a large pulsation reduction effect can be obtained with less operating loss in the movable orifice than in the fixed orifice.

In the embodiment shown in FIG. 1, the bellows 9
Is integrally formed with the orifice support tube 5, but it is also possible to form both of them separately and form a flange connection, for example.

The pipe vibration damping joint according to the present invention is not limited to the one described in the drawings and the description of the embodiments, and various design changes can be made without departing from the gist of the present invention. It is a thing.

[0017]

As described above, according to the present invention, since the movable orifice connected to both pipes with the vibration isolating support means is interposed, the pulsation of the fluid absorbs energy by the movable orifice and the vibration isolating support means. Then, the vibration of the pipe is blocked by the vibration-proof support means, and the propagation of vibration and pulsation can be prevented at the same time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a pipe damping joint according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a pipe damping joint according to another embodiment of the present invention.

FIG. 3 is a diagram comparing the performances of a fixed orifice and a movable orifice.

FIG. 4 shows a conventional piping damping joint, (A) is a bellows type vertical sectional view, (B) is an orifice type vertical sectional view,
(C) is a cross-sectional view of an orifice type.

[Explanation of symbols]

1: Piping, 2, 3: Anti-vibration rubber, 4: Orifice, 4
h: orifice hole, 5, 6: orifice support tube, 7: spring, 8: damper, 9: bellows.

Claims (4)

[Claims] 1. A pipe damping joint, characterized in that a movable orifice connected to both pipes is interposed between the pipes to be connected so as not to come into direct contact with the pipes by means of a vibration-proof support means. 2. A bellows type joint is connected to one of the pipes to be connected by interposing a movable orifice connected to the both pipes with vibration-proof support means so as not to come into direct contact with the pipes. Piping damping joint characterized by being provided. 3. The pipe damping joint according to claim 1, wherein the vibration-damping support means is made of vibration-proof rubber. 4. The pipe vibration damping joint according to claim 1, wherein the vibration-damping support means comprises a spring and a damper.