JPH09273694A - Vibrationproof pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously prevent vibration of a pipe and propagation of pulsation of fluid with a little flow loss. SOLUTION: An impeller cease body 7 formed by expanding one side of a passage into a semi circular shape is so formed as to be continued to a bellows 2, an impeller 5 is rotatably provided in the impeller case body 7 so that vanes 5b may traverse the passage, and an inertial disc 6 is attached to a shaft 5a of the impeller. A nose part 8 is formed on the upstream angle part of the impeller case body 7 so that flow may be smoothly joined. An accumulator 3 is so provided as to be connected to the impeller case body 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration pipe joint that prevents the propagation of vibrations in pipes and the propagation of pressure vibrations or pulsations of fluid flowing in the pipes.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional vibration isolation pipe joint. FIG.
What is shown in (A) is a vibration-proof pipe joint in which a bellows (bellows) 2 is formed. 2B and 2C, the pipes 1 and 1 are connected through the orifice 9. Generally, a pump or the like (not shown) is usually provided in the piping system, and the pump or the like causes vibration in the pipe 1 to propagate and pressure vibration or pulsation also occurs in the fluid flowing in the pipe 1. Propagate. As shown in FIG. 2A, the flexibility of the bellows 2 prevents the vibration of one of the pipes 1 from propagating to the other pipe 1. 2B and 2C 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 9h.

[0003]

Although the conventional vibration-proof pipe joint is as described above, the use of the bellows 2 shown in FIG. 2 (A) can prevent the vibration of the pipe 1 from propagating. However, the pulsation of the fluid flowing in the pipe 1 cannot be prevented from propagating. The orifice 9 shown in FIGS. 2B and 2C can prevent the propagation of fluid pulsation,
Propagation of vibration in the pipe 1 cannot be prevented. Also,
When the bellows 2 and the orifice 9 are connected in series and used, the vibration of the pipe 1 and the propagation of the pulsation of the fluid can be prevented, but the orifice 9 is required to prevent the propagation of the pulsation of the fluid.
It is necessary to reduce the area of the orifice hole 9h, and there is a problem that if the area of the orifice hole 9h is reduced, the flow resistance of the fluid increases and the loss increases.

The present invention has been made in order to solve the above problems, and has a low flow resistance loss of fluid, and can simultaneously prevent the propagation of vibration of the pipe and the propagation of pulsation of the fluid flowing in the pipe. The purpose is to obtain a pipe joint.

[0005]

The vibration-proof pipe joint according to the present invention forms an impeller casing having a semicircular shape in which one side portion of a flow path is expanded in succession to a bellows. An impeller is rotatably provided so that the blade crosses the flow passage, and an inertial disk is attached to the shaft of the impeller. Further, a nose portion is formed in a protruding manner at the upstream corner portion of the impeller housing so that the flow from the upstream and the flow rotating in the impeller housing are smoothly combined. Further, an accumulator is provided so as to be connected to the impeller housing to absorb the pressure fluctuation of the fluid.

In the vibration-proof pipe joint according to the present invention, the flexibility of the bellows absorbs the vibration of the pipe and cuts off the propagation. Further, the flowing fluid pushes the blade on the side of the impeller housing of the impeller that does not swell, and the pushed impeller freely rotates with almost no resistance, so the resistance loss of the flowing fluid is small. The pulsation of the fluid is applied to the blades of the impeller.When the high-pressure part of the pulsation is applied, the impeller rotates faster, and when the low-pressure part is applied, the impeller rotates slowly. The inertial disk attached to the device suppresses fluctuations in the rotational speed of the impeller due to its rotational inertia, so that the flow is smoothed. In addition, the nose portion smoothly joins the fluid flowing into the impeller housing to the flow that has been rotating in the impeller housing and guides it to the unexpanded side of the impeller housing, so that the impeller rotates smoothly and Resistance loss is reduced. Further, the accumulator absorbs and attenuates the pressure fluctuation remaining in the fluid.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 and 1 are pipes and 2
Is a bellows, 3 is an accumulator, 5 is an impeller, 6 is an inertial disk, 7 is an impeller housing, and 8 is a nose part. A pump or the like (not shown) is provided in one of the pipes 1 and 1, and is connected via this vibration isolation pipe joint so that the vibration of the pipe 1 and the pressure pulsation of the fluid generated by the pump or the like do not propagate to the other. The bellows 2 has a wavy vertical cross section.

As shown in FIG. 1, the vibration-proof pipe joint is formed with an impeller casing 7 in which an impeller 5 is provided in the flow path adjacent to the bellows 2. The impeller housing 7 has a shape in which one side portion (upper side of the drawing) of the flow path is expanded in a semicircular shape in a vertical cross section, and the radius of the semicircular shape of the impeller housing 7 is substantially equal to the diameter of the flow path. Has become. The impeller 5 is rotatably provided in the impeller housing 7. The impeller shaft 5a is provided at the center of the semicircular shape of the impeller housing 7 while being supported by a bearing provided in the impeller housing 7 in a direction perpendicular to the fluid flow direction. The blade 5b is attached to the impeller shaft 5a and is provided so as to rotate inside the impeller housing 7 and cross the flow path. The blade 5b may be a flat plate, but as shown,
It is desirable to form a spoon-shaped curved surface with the concave surface facing the upstream side in the main stream because the rotation of the impeller 5 and the flow of fluid are smooth.

Further, as shown in FIG. 1, inertia disks 6 are attached to both ends of an impeller shaft 5a which penetrates both sides of the impeller housing 7 and projects. The inertial disk 6 rotates together with the impeller 5, but is formed so that its rotational moment of inertia is as large as possible, for example, the outer peripheral portion of the inertial disk 6 has a large mass.

Further, in FIG. 1A, the flow linearly inflowing horizontally from the left upstream to the lower half of the impeller casing 7 in the drawing and the inside of the impeller casing 7 are rotated counterclockwise. A nose portion 8 is formed so as to project at an upstream corner of the impeller housing 7 so as to smoothly join the flow. As shown in FIG. 1 (A), the upstream surface of the nose portion 8 is formed in a shape that guides the flow from the upstream from the horizontal direction to the diagonally lower right,
The right side surface of the nose portion 8 is formed by extending the circular inner surface of the impeller housing 7.

Further, as shown in FIG. 1, an accumulator 3 is provided on the top of the impeller housing 7 by a communication pipe 3c.
It is provided in communication with the inside of the. Accumulator 3
The volume, the diameter and the length of the communication pipe 3c, and the like have dimensions calculated and designed to absorb the pressure pulsation of the fluid. If the fluid passing through this pipe system is a liquid, an appropriate amount of air or an inert gas is enclosed in the accumulator 3.

Next, the operation and action of the vibration isolation pipe joint shown in FIG. 1 will be described. It is assumed that a pump or the like (not shown) is provided in the pipe 1 on the left side of the figure. Vibration generated by a pump or the like propagates from the pipe 1 on the left side of the figure, and pressure pulsation also propagates in the fluid in the pipe 1. When the vibration of the pipe 1 propagated from the pipe 1 on the left side of the figure to the vibration damping pipe joint reaches the bellows 2, the vibration is absorbed by the flexibility of the bellows 2,
Vibration is prevented from propagating to the pipe 1 on the right side of the figure.

The fluid flowing from the left side of FIG. 1 (A) passes through the bellows 2 and flows into the linear portion of the lower portion of the impeller housing 7 in the figure, and is located at the lower position of the impeller 5 in the figure. The blade 5b is pushed to the right and flows to the right. Since the impeller 5 is freely rotatable, it is rotated counterclockwise by being pushed by the fluid flowing from the left to the right in the figure, and a part of the fluid is rotated counterclockwise together with the impeller 5 to rotate the impeller casing 7. It circulates counterclockwise in the upper semi-circular part of. If the fluid flowing from the left has pulsation and the fluid that has a high pressure and tries to flow quickly hits the blade 5b at the lower position, the force of the fluid pushes the blade 5b to the right and impeller 5 Try to rotate the fast. But,
Since the inertial disk 6 is attached to the impeller shaft 5a of the impeller 5, fluctuations in the rotational speed of the impeller 5 are suppressed by the inertia of the inertial disk 6, and the portion of the fluid that tries to flow faster is at the lower position. The flow velocity becomes slower by hitting the blade 5b located at.
On the contrary, the portion where the fluid pulsation tends to flow slowly tends to be accelerated by the blades 5b due to the constant rotation of the impeller 5 due to the inertia of the inertial disk 6. In this way, the impeller housing 7
The pulsation of the fluid passing through is smoothed.

The fluid flowing from the left side of FIG. 1 (A) through the bellows 2 is the fluid rotating counterclockwise in the impeller casing 7 at the nose portion 8 of the impeller casing 7. Join. At this time, the upper part of the main flow flowing from the left to the right is guided obliquely downward to the right by the nose portion 8, so that it smoothly joins with the fluid rotating counterclockwise in the impeller housing 7. To do. That is, the flow turbulence in this portion is small and the flow loss is small.

As shown in FIG. 1, an accumulator 3 is provided in communication with the inside of the impeller casing 7 by a communication pipe 3c, and if the fluid passing through this pipe system is a liquid, an appropriate amount of air or When the inert gas is filled, the accumulator 3 absorbs the pressure fluctuation of the fluid remaining in the impeller housing 7. By setting the volume of the accumulator 3 and the diameter and length of the communication pipe 3c so as to resonate with the frequency of the pressure pulsation of the fluid, the accumulator 3 well absorbs the pressure pulsation of the fluid.

In the vibration-proof pipe joint shown in FIG. 1, the inertial disk 6 is provided outside the impeller casing 7. However, the left and right sides of the impeller casing 7 in FIG. The inertial disk 6 may be provided inside 7. In addition, since there is inertia of the fluid that rotates in the impeller housing 7 as the impeller 5 rotates, the inertia of the rotating fluid can be expected to have an effect of smoothing the pulsation, so the inertial disk 6 may be omitted depending on conditions. It is also possible. Although FIG. 1 (A) shows four blades 5b of the impeller 5, five or more blades may be provided. Further, in FIG. 1 (A), the curved blades 5b of the impeller 5 are attached to the impeller shaft 5a substantially in the radial direction, but they may be attached so as to be tilted in the counterclockwise rotation direction in the figure. .

[0017]

As described above, according to the present invention, the bellows absorbs the vibration of the pipe to block the propagation, and the impeller having the inertial disk rotatably provided in the impeller housing has the same structure. The inertia of the rotary motion smoothes the flow pulsation in the pipe. Also, the nose portion smoothes the flow to reduce loss. The accumulator also absorbs pressure fluctuations of the fluid.

[Brief description of drawings]

FIG. 1 shows an embodiment of a vibration-proof pipe joint according to the present invention, (A) is a longitudinal sectional view and (B) is a front sectional view.

2A and 2B show a conventional vibration-proof pipe joint, in which FIG. 2A is a bellows type vertical sectional view, FIG. 2B is an orifice type vertical sectional view, and FIG.
FIG. 4 is a cross-sectional view of an orifice type.

[Explanation of symbols] 1: Piping, 2: Bellows, 3: Accumulator, 3
c: communication tube, 5: impeller, 5a: impeller shaft, 5b: impeller, 6: inertia disk, 7: impeller housing, 8: nose part.

Claims (3)

[Claims] 1. A vibration isolation pipe joint having a bellows, comprising:
Following the bellows, an impeller housing having a shape in which one side of the flow path is expanded in a semicircular shape is formed, and an impeller is rotatably provided in the impeller housing so that the blades cross the flow path. ,
An anti-vibration pipe joint in which an inertial disk is attached to the shaft of this impeller. 2. A nose portion is formed in a projecting manner at the upstream corner portion of the impeller casing so that the flow from the upstream and the flow rotating in the impeller casing are smoothly combined. Anti-vibration pipe fitting described in. 3. The vibration-isolating pipe joint according to claim 1, further comprising an accumulator connected to the impeller casing to absorb pressure fluctuation of fluid.