JP4342240B2 - Cage valve - Google Patents

Description

  The present invention relates to a cage valve including a cage having a flow control window on a peripheral wall and a valve plug that moves up and down in the cage to control the flow rate of the fluid by controlling the opening area of the flow control window.

  The flow rate of the cage valve is adjusted by changing the opening area of a plurality of flow rate control windows provided on the cage peripheral wall. As a mechanism for changing this flow control window, a cylindrical or circular pipe-shaped valve plug is mounted inside the cage, and the valve plug is reciprocated up and down by an operating device, etc., so that the valve plug opens the area of the flow control window. A method of changing the value is generally used.

  In a cage valve having such a mechanism, the liquid that vigorously flows out from the lower outlet of the cage valve also violently collides with the bottom surface of the valve on the downstream side of the valve, resulting in damage to the valve, vibration, noise, and cavitation.

  FIG. 7 shows a cross-sectional view of a main part of a cage valve provided with a conventional valve plug for the purpose of solving such a problem. A cylindrical projection 20 projecting inward from the cage is integrally formed at the center of the bottom surface portion 7B of the cage 7 fitted and fixed to the opening of the partition wall provided in the valve main body 1. A large number of small holes 9 are formed on the surface. A cylindrical recess 21 is formed on the bottom surface of the cage 7. The space | interval of the bottom face part 7B of the cage 7 and the downstream valve body bottom part 6 of the valve main body 1 is open. In order to form the small hole 9 in the projecting portion 20, the cage 7 is composed of a bottom surface portion 7B on which the projecting portion 20 is formed, and a cage body 7C composed of a cylindrical body with both ends being fitted and fixed. The bottom surface portion 7B is fitted into the lower surface side opening of the cage body 7C and joined by welding.

  In such a low-noise cage valve, when the valve is opened by the upward movement of the valve plug 15 slidably fitted, the controlled fluid in the upstream flow path 3 enters the cage 7 and is formed in the protrusion 20. It flows out from the small hole 9 to the downstream flow path 4. At this time, the controlled fluids that have permeated through the small holes 9 collide with each other in the recess 21, dissipate and diffuse their kinetic energy, and are pushed to the downstream flow path 4. For this reason, it is remarkably small as compared with the valve device in which the fluid directly collides with the downstream valve body bottom 6 of the valve body 1, and it is effective that the vibration of the valve body 2 and further the downstream piping are excited to generate noise. (For example, refer patent document 1).

JP-A-8-93964

Since the cage valve device provided with a conventional plug is configured as described above, the bottom portion shape of the cage becomes larger projecting structure on the downstream side valve chamber, necessary to increase the downstream valve chamber to the valve the body longitudinally It banara not a, had ended up in increasing the size of the valve this body.

  The present invention has been made paying attention to the above circumstances, and the purpose of the present invention is to prevent damage, vibration, noise, cavitation of the valve by vigorously colliding the liquid that has flowed out violently with the bottom surface of the valve on the downstream side of the valve. And providing a small cage valve.

The cage valve according to the present invention slides the cage having a plurality of windows in a fixed and a peripheral wall on one chamber which is divided by a partition wall for dividing the valve present inside the upstream side and the downstream side, the cage In a cage valve having a valve plug that opens and closes the cage window, a projection that is formed directly below the cage window and projecting in the inner diameter direction only at the lower end of the bottom surface portion that is substantially the same height as the cage partition wall. A part is provided.

In the cage valve according to the present invention, a valve plug drift portion for diverting and decelerating the fluid that has flowed into the cage is formed on the bottom surface of the valve plug, and the valve plug drift portion is directly below each window of the cage. Only the lower end of the bottom surface having substantially the same height as that of the partition wall is formed so as not to come into contact with the protruding portion formed in the inner diameter direction.

According to the present invention, a directly under the respective windows of the cage, by the projecting portion which is protruded to the inside diameter direction only on the bottom surface lower end of the partition wall having substantially the same height of the cage, passes through the outlet of the cage bottom portion By generating rectification, resistance, uneven flow, dispersed flow, etc. against the fluid that flows, the fluid does not collide directly with the inner bottom surface of the downstream valve directly, so that the cage valve bottom protrudes into the downstream valve chamber. Valve damage, vibration, noise, and cavitation can be prevented without increasing the size.
Further, when assembling the cage to the valve the body can be engaged with the tool for assembling a partition wall substantially the same height of the bottom portion bottom only the protrusion which is protruded to the inside diameter direction of the cage, There is no need to provide protrusions or recesses that engage the assembly tool in other parts of the cage.

According to the present invention, by providing the valve plug drifting portion, a larger drift is given to the fluid in the cage, and the drifted flow collides with the protrusion, so that the flow is diverted and decelerated, and the effect is further increased. In particular, damage to the valve, vibration, noise and cavitation can be prevented.
In addition, the valve plug drift portion changes the flow direction of the fluid flowing from the window from the outer peripheral direction of the cage to the center portion to the hole direction provided in the partition wall, so that the flow flows into the cage from each opposed window. Thus, it is possible to avoid the direct collision of the fluids, and the vibration generated by the direct collision of the fluids flowing into the cage from the opposing windows as in the conventional case can be greatly reduced.

Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view of an essential part showing a state in which the valve device according to Embodiment 1 is fully closed. FIG. 2 is a sectional view showing the valve device in a fully opened state. FIG. 3 is a view of FIGS. 1 and 2 as viewed from the A direction. In the figure, the valve body 1 is divided into an upstream flow path 3 and a downstream flow path 4 by a partition wall 2 that is a partition wall. A cylindrical cage 7 is provided between the upper lid 5 that closes the upper end opening of the valve body 1 and the partition wall 2. The upper lid 5 is fixed to the valve body 1 with bolts 27 and nuts 28. Although not shown, a gasket is fitted between the upper lid 5 and the cage 7, and a gasket is fitted between the cage 7 and the valve body 1. The lower end portion of the cage 7 is fitted into a through hole formed in the center of the partition wall 2 via the gasket 10, and the cage 7 is fixed between the upper end opening 29 of the valve body 1 and the partition wall 2. A plurality of flow rate control windows 13 for communicating the upstream flow path 3 and the downstream flow path 4 are formed in the peripheral wall of the cage 7. A valve seat 14 located below the flow control window 13 is formed on the inner peripheral wall surface of the cage 7. A seat portion 19 is provided on the valve plug 15, and the seat portion 19 faces the valve seat 14. A valve plug (valve element) 15 is slidably fitted into the cage 7 along its inner peripheral wall surface.

The cage 7 is provided with a portion in which the flow rate control window 13 is provided and a lower cage portion 7A that comes into contact with the partition wall 2 so as to be divided. The lower cage portion 7A is coupled to the valve body via a gasket 10. Further, a spiral is provided in a hole provided in the lower outer periphery of the lower cage portion 7A and the partition wall 2, and the lower cage portion 7A is detachably screwed to the partition wall 2. Four protrusions 8 having substantially the same height as the partition walls are provided on the inner periphery of the lower cage portion 7A. When the lower cage portion is screwed to the partition wall 2, the lower cage portion 7 </ b> A including the protruding portion 8 rotates by bringing the jig into contact with the protruding portion 8 and rotating the jig. 7A and the spiral part of the partition wall 2 couple | bond together.
When used for a high-pressure fluid, a sufficient seal is required. A strong tightening force is required to sufficiently seal the gasket 10. Conventionally, a notch or the like has been separately provided in the lower cage portion as a location for engaging a jig for fastening to the cylindrical lower cage portion 7A. The dedicated jig and the notch are engaged, and the jig is rotated and screwed. However, by using the protrusion 8, it is necessary to provide the lower cage part 7A with a notch used only for screwing. There is no.
The protrusion 8 is provided in a place where the valve plug 15 does not collide with the valve plug 15 even when the valve plug 15 is fully closed, that is, at the lowest position (FIG. 1). It is preferable to provide at the lowermost end of the lower cage portion 7A so as not to collide with the valve plug 15.
The valve plug 15 is attached to the tip of the valve shaft 18. The valve shaft 18 is slidably provided in a through hole packing (not shown) provided in the center of the upper lid 5.

Next, the operation will be described. In the fully closed state of FIG. 1, when the valve shaft 18 is operated upward by an operation unit (not shown) or manually, the flow control window 13 is closed by the valve plug 15 and the seating surface of the valve plug is seated on the valve seat 14. The valve plug 15 gradually moves upward from the close contact state.
Then, the flow control window 13 closed by the valve plug 15 is opened. The flow rate is controlled by the rate at which the flow rate control window 13 is closed. The fluid flowing from the flow rate control window 13 toward the center of the cage changes the flow direction in the direction of the hole provided in the partition wall 2 in the cage valve.
The fluid that has passed through the periphery of the protrusion 8 provided on the lower cage portion 7A collides with the protrusion, so that the flow is disturbed, and the fluid is decelerated without colliding directly with the inner bottom surface of the valve on the downstream side of the valve. It flows to the downstream side valve this body. Since the flow is decelerated and does not vigorously collide with the inner bottom surface of the downstream valve, vibration and noise are reduced, and damage to the valve and cavitation can be prevented.
When the valve shaft 18 is further operated, the valve plug 15 is fully opened without closing the flow control window 13.

Although the cage as the two members using the lower cage portion 7A has been described, the lower cage portion 7A may be integrally formed without being a separate member.
4 has been described what Tsunohobo a rectangular protrusions 8, but considering the flow impinging on a downstream side valve Body bottom 6, the shape is one that can be changed as appropriate.
Further, as the fluid flowing from the flow control window 13 does not flow to the downstream side valve Body bottom 6 directly, the number of flow control window 13 and the projection 8 is the same, the projections 8 directly below the flow control window 13 arrangement, and it is effective to to flow to the downstream side valve body bottom 6 after the flow from the flow control window 13 has collided reliably once the protrusion 8.
Further, the lower cage portion 7A and the protruding portion 8 may be joined later by welding or the like, but may be integrally cast. When fixing by welding, the plurality of protrusions 8 are not separately welded to the lower cage, but if a plurality of integrally formed protrusions 8 are welded to the lower cage part 7A, the number of welded portions can be reduced.

Embodiment 2. FIG.
FIG. 4 is a longitudinal sectional view of a main part showing a state in which the valve device according to the second embodiment is fully closed. FIG. 5 is a sectional view showing the valve device in a fully opened state. 6 is a view of FIGS. 4 and 5 as seen from the B direction. Since the configuration except that the valve plug lower end drifting portion 11 is added to the lower portion of the valve plug 15 is the same as that of the first embodiment, the description thereof is omitted.

As shown in FIGS. 4 and 6, the valve plug lower end drifting portion 11 is provided on the lower end surface of the valve plug 15 so as not to collide with the protrusion 8 even when the valve plug 15 is closed. The cross section of the valve plug lower end drifting portion 11 has a shape having a constricted portion 12 so as to extend between adjacent protruding portions 8. By adopting such a shape, there is no gap between the center of the lower cage portion 7A and the plurality of protruding portions 8 without colliding with the protruding portions 8, and the fluid flows easily. The valve plug lower end drifting portion 11 is designed to be as easily spaced as possible from the protrusion 8 and the inner peripheral surface of the lower cage portion 7A and to be easily processed. Of course, when the shape and number of the protrusions 8 are changed, the shape of the valve plug lower end drifting portion 11 is also changed as appropriate.
The valve plug lower end drifting portion 11 is provided in such a direction that the center of the constricted portion 12 of the valve plug lower end drifting portion 11 faces the center of the flow control window 13. When the valve is opened, the fluid flowing in from the flow control window 13 collides with the constricted portion 12, decelerates, and then turns to the opening of the partition wall 2. Fluid flowing along the constricted portion 12 collides with the projecting portion 8, after further reduction, flows to the downstream side valve Body bottom 6.

By providing the valve plug lower end drifting portion 11, the flow in the cage can be effectively shunted and decelerated, and the flow that strikes the bottom face of the valve on the downstream side is further reduced, compared with the first embodiment. However, vibration and noise can be further reduced, and valve damage and cavitation can be prevented.
Since there is a valve plug lower end drifting portion that changes the flow direction of the fluid flowing in from the window from the outer peripheral direction of the cage 7 to the center portion to the hole direction provided in the partition wall 2, each flow control window 13 facing each other. Can prevent the fluids flowing into the cage from directly colliding with each other, and greatly reduce the vibration caused by the direct collision of the fluids flowing into the cage from the opposing windows as in the conventional and the first embodiment. Can be relaxed.

It is sectional drawing of the cage valve of the closed state which shows Embodiment 1 of this invention. It is sectional drawing of the cage valve of the open state which shows Embodiment 1 of this invention. It is the figure which looked at FIG.1 and FIG.2 which show Embodiment 1 of this invention from the A direction. It is sectional drawing of the cage valve of the closed state which shows Embodiment 2 of this invention. It is sectional drawing of the cage valve of the open state which shows Embodiment 2 of this invention. It is the figure which looked at FIG.4 and FIG.5 which show Embodiment 2 of this invention from the B direction. It is sectional drawing which shows the cage valve of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 2 Partition wall 7 Cage 7A Lower cage part 8 Protrusion part 11 Valve plug lower end drift part 15 Valve plug

Claims (2)

A cage having a plurality of windows in a fixed and a peripheral wall of the valve present inside the chamber of one divided by the upstream and the partition that divides the downstream side, to open and close the windows of the cage to slide the cage In a cage valve with a valve plug,
A cage valve characterized in that a projecting portion is formed directly below each window of the cage and projecting in the inner diameter direction only at the lower end of the bottom surface of the cage and having substantially the same height as the partition wall . The cage valve according to claim 1, wherein
A valve plug drift portion for drifting the fluid flowing into the cage is formed on the bottom surface of the valve plug, and the valve plug drift portion is directly below each window of the cage and is substantially the same as the partition wall of the cage. A cage valve characterized by having a shape that does not come into contact with a protruding portion that protrudes in the inner diameter direction only at the lower end of the bottom surface portion of the height .

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