JPH03213784A - Valve device - Google Patents

Abstract

PURPOSE:To achieve the noise reduction of the valve device by assembling a sound absorbing cylinder into the valve body and arranging a shell member having a radial small holes on the peripheral surface, at an upstream side focus position, and arranging a sound absorbing member in the vicinity of a downstream side focus. CONSTITUTION:The inner peripheral surface of a sound absorbing cylinder 28 is formed into elliptical form, and has the upper and lower focuses Q1 and Q2 arranged in the flow direction of fluid. A semispherical shell member 32 is fitting-arranged in an upper edge opened port part. The center of the semispherical part 32A nearly coincides with the upstream side focus Q1, and a number of small holes 35 are formed radially in the semispherical part 32A. A sound absorbing member 33 is arranged in the vicinity of the downstream side focus Q2 of the sound absorbing cylinder 28. The sound generated on the downstream side of a throttle part is reflected by the inner peripheral surface of the sound absorbing cylinder 28, and converged to the downstream side focus. Accordingly, the noise collides with the sound absorbing member, and is effectively attenuated and absorbed, and the noise reduction of the device can be achieved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a low noise type valve device.

[Prior Art] Generally, when a valve device provides resistance to the flow of fluid, undesirable noise may be generated due to turbulence of the flow generated at the throttle portion of the valve.

Therefore, various valve devices that prevent, reduce, or absorb the generation of noise have been proposed. FIG. 4 is a sectional view showing a conventional example of such a low-noise valve device. The figure shows a high-pressure gas pressure reducing valve, where 1 is a tub-shaped valve body partitioned at the center by a partition wall 2, and 3 is a cylindrical valve seat fixed on the partition wall 2 of the valve body 1. , this valve M3
A communication hole 3A is formed in a part of the upper part of the circumferential surface. 4
5 is a lid that closes the upper opening of the valve body 1 and fixes the valve seat 3 on the partition wall 2; 5 is a cylindrical valve plug that is slidably fitted into the valve seat 3; and 6 is a lid. A valve shaft 8, which is inserted into the center hole of the body 4 through a packing 7 and raises and lowers the valve plug 5, is a diff user. It is arranged on the downstream side, that is, below the valve seat 3.

In such a configuration, fluid flows from the opening IA on the right side of the valve body 1 as shown by arrow A in the figure, and flows through the communication hole 3A of the valve seat 3 and the passage formed on the lower end circumferential surface of the valve plug 5. The fluid flows out to the left opening IB through the hole 10 and the hole 11 formed in the center of the partition wall 2, but the fluid is depressurized into the valve seat 3 through the flow hole 3A of the valve seat 3. In the case of inflow, as shown in the figure, there is a potential core 12 region where the flow velocity is the same as that of the inflow fluid, and a mixing region 1 where the fluid is drawn in around this potential core 12 and becomes turbulent.
3 occurs. This mixing zone 13 generates strong noise at a high frequency, and the noise is further transmitted to the downstream piping section and leaks to the outside. Therefore, if the diff user 8 is provided on the downstream side of the flow constriction section, the pressure of the fluid is reduced when the fluid passes through the small hole 9, thereby preventing the generation of noise.

[Problems that Q Ming attempts to solve] However, in such conventional valve devices, the differential user 8 is not designed with particular acoustic consideration, and is designed as a type of resistance element. However, the design was limited to considering the flow rate characteristics, and the reduction in noise level was only delayed to a certain extent as a secondary effect, which was insufficient as a low-noise valve.

Furthermore, no measures have been taken to attenuate or absorb the noise generated when the fluid passes through the small holes 9 of the differential user 8, and there is a drawback that the noise is propagated to the piping on the secondary side. Ta.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a valve device that can significantly reduce and absorb the noise generated downstream of the throttle section. It is about providing.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a cylindrical valve device whose inner peripheral surface is formed into an elliptical curved surface in a valve device that controls the flow rate by advancing and retracting movement of a valve plug facing a flow hole. A sound-absorbing tube shaped like the above-mentioned sound-absorbing tube is installed on the downstream side of the communication hole so that its two focal points are lined up in the fluid flow direction. Xll
@A hemispherical shell member whose center substantially coincides with the focal point and in which a plurality of small holes are formed radially from the center is disposed within the sound absorbing tube, and a sound absorbing shell member is provided near the focal point on the downstream side of the sound absorbing tube. This is an arrangement of members.

[Operation] In the present invention, when fluid passes through the small holes of the hemispherical shell member, jet noise is generated around the center of the shell member.

This jet noise spreads radially, is reflected by hitting the elliptical inner circumferential surface of the sound-absorbing tube, and is converged, attenuated, and absorbed by a sound-absorbing member disposed near the focal point on the downstream side of the sound-absorbing tube.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is a sectional view showing an embodiment of the valve device according to the present invention applied to a cage type valve device, and FIG. 2 is an enlarged sectional view of the main parts. In these figures, reference numeral 20 denotes a valve body having a substantially "1" shape with openings at the top and bottom and at the middle part of one side in the height direction;
A cylindrical valve seat 23 having a communication hole 22 formed on the circumferential surface of the upper end is fitted into the upper end opening 21, the side opening 24 forms an upstream opening, and the lower end opening 25 forms a downstream opening. forming a section. A valve plug 27 that is raised and lowered by a valve shaft 26 is slidably fitted inside the valve seat 23 .

Reference numeral 28 denotes a cylindrical sound-absorbing tube whose upper end is joined to the lower end of the valve M23 and which is disposed coaxially with the valve seat 23 on the downstream side of the throttle section 29. The inner peripheral surface of the sound-absorbing tube 28 is formed in an elliptical shape. has two focal points Ql-Q2, upper and lower, aligned in the fluid flow direction,
A hemispherical shell member 32 is fitted within the upper end opening 31, and a sound absorbing member 33 is disposed on the lower side of the interior via a holding member 34.

The shell member 32 has a cylindrical shape in which the outer circumferential surface of the upper end part fits into the inner circumferential surface of the upper end opening 31 of the sound-absorbing cylinder 28, and the lower end side is formed in a hemispherical shape so as to be convex toward the inside of the sound-absorbing cylinder 28, The center of this hemispherical portion 32A substantially coincides with the upstream focal point Q1,
In addition, a large number of small holes 35 are formed radially in the hemispherical portion 32A around the center.

The sound absorbing member 33 is made of a metal rope or the like, and is similar to the sound absorbing tube 2.
8, and is disposed in the vicinity of the downstream focal point Q2 of the holding member 34, and is disposed within a conical recess 36 provided in the center of the holding member 34.

The holding member 34 is formed in a ring shape and is attached to the sound absorbing tube 2.
A rib (
A plurality of communication holes 37 are formed, which are partitioned by holes (not shown).

The arrangement structure of the sound absorbing member 33 is that instead of disposing it in the recess 33 provided in the center of the holding member 34, it is placed on the center of the upper surface of the holding member 34 as shown in FIG. It may be covered by a porous member 38.

In such a configuration, fluid flows from the upstream opening 24 of the valve body 20 to the communication hole 22 of the valve seat 23 and the shell member 32.
When the liquid flows into the sound absorbing tube 28 through the small hole 35, acoustic waves are generated due to the shearing of the flow by the throttle part 29 of the valve, and jet noise is also generated at the small hole 35 exit. As shown in FIG. 2, these acoustic waves and jet noise take advantage of the fluid flow to reach the center of the shell member 32, that is, the upstream focal point Q of the sound absorbing tube 28.
It spreads radially around L as the center, passes through the small hole 35, enters the sound absorbing cylinder 28, and when it hits the elliptical inner peripheral surface and is reflected, it is converged at the downstream focal point Q2, and when it hits the sound absorbing member 33, most of it is attenuated or absorbed. and converted into heat.

In other words, the present invention utilizes the elliptical inner circumferential surface 30 of the sound absorbing tube 28 to reduce the noise generated downstream of the diaphragm 29 to the downstream focal point Q2.
As a result, the noise absorption effect is large, and almost no noise is propagated to the downstream pipeline, making it possible to achieve low noise.

On the other hand, the fluid that has flowed into the sound absorbing cylinder 28 through the small hole 35 of the shell member 32 flows out through the communication hole 37 of the holding member 34 to the downstream side of the valve body 20.

[Advantageous Effects of the Invention 1] As described above, the valve device according to the present invention incorporates a sound absorbing cylinder having an elliptical inner circumferential surface and two focal points into the valve body, and also incorporates a sound absorbing cylinder having two focal points on the upstream focal position. A shell member with a central radial small hole on its circumferential surface is arranged, and a sound absorbing member is arranged near the focal point on the downstream side, so that the noise generated downstream of the aperture part is absorbed by the inner peripheral surface of the sound absorbing tube. It can be reflected by the beam and focused on the downstream focal point. Therefore, this noise is effectively attenuated and absorbed when it hits the sound absorbing member, making it possible to reduce the noise of the valve device.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the valve device according to the present invention applied to a cage type valve device, FIG. 2 is a sectional view of a sound absorbing tube, and FIG. 3 is a sectional view of another embodiment of the present invention. FIG. 4 is a cross-sectional view of a conventional valve device. 20... Valve body, 22... Distribution hole, 23... Valve seat, 27... Valve plug, 28... Sound absorbing cylinder, 32...
...Shell member, 33--Sound absorbing member, 34...Holding member, 35...Small hole, Ql...Upstream focal point of ellipse, Q
l: Downstream focus of the ellipse.

Claims (1)

[Claims] In a valve device that controls the flow rate by advancing and retreating movement of a valve plug facing a flow hole, a cylindrical sound-absorbing cylinder whose inner circumferential surface is formed into an elliptical curved surface is used, and two focal points of the cylinder are arranged to control the flow of fluid. A hemispherical shell member is installed on the downstream side of the communication hole so as to be lined up in the direction, the upstream focal point of the sound absorbing tube substantially coincides with the center, and a plurality of small holes are formed radially from the center of the hemispherical shell member. What is claimed is: 1. A valve device comprising: a sound absorbing member disposed within a cylinder and near a focal position on the downstream side of the sound absorbing cylinder;