JPH0130697Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a cage that controls the flow rate of fluid by the relative angle between a window provided in the peripheral wall of a cylindrical cage and a valve plug that slides inside the cage. Concerning improvements to valves.

[Conventional technology]

A cage valve used for controlling the flow rate of fluid is generally constructed as shown in FIG. To explain this based on the figure, the valve body 1 is connected to the partition wall 2.
The inside is partitioned into an upstream flow path 3 and a downstream flow path 4, and between the upper cover 6, which is fitted into the upper open end and fixed with bolts 5, and the partition wall 2,
A cylindrical cage 7 and a seat ring 8 are fitted through gaskets 9 and 10. The cage 7 is coaxial with the seat ring 8 and its lower end surface is aligned with the seat ring 8.
A plurality of windows 11 are opened in the peripheral wall and in contact with the upper surface, and communicate the inside of the cage 7 with the upstream flow path 3, and the windows 11 are approximately T-shaped with a wide part and a narrow part. It is formed. On the other hand, the seat ring 8 is fitted into a through hole 20 provided in the partition wall 2 via a packing 10, and its lower open end is opened to the downstream flow path 4. A valve plug 14 is slidably fitted into the inner hole of the cage 7 and is attached to the lower end of a valve rod 13 that is slidably penetrated through the upper lid 6 via a packing 12. At the lower end of the seat ring 8, there is an underwear seat part 16 that seats on the valve seat 15 provided at the upper end opening of the seat ring 8 when fully closed.
is provided. Further, an upper seating portion 18 is provided on the outer circumferential portion of the upper end of the valve plug 14, and is seated on the valve seat 17 formed on the inner circumferential surface of the cage 7 when the valve plug 14 is fully closed.

In such a configuration, when the valve stem 13 is moved up and down by the actuation of the drive unit by the automatic control device or by manual operation, the valve plug 14 moves together with the valve stem 13 to change the opening degree of the window 11, that is, the opening area. The flow rate of the controlled fluid flowing from the upstream flow path 3 to the downstream flow path 4 through the window 11 of the cage 7 and the seat ring 8 is thereby controlled, and the shape of the window 11 allows the desired flow rate to be controlled. Flow rate characteristics can be obtained.

[Problem that the invention attempts to solve]

In the cage valve as described above, it is necessary to form a specially shaped window 11 on the peripheral wall of the cage 7, so the cage 7 is usually made of a cast product or a special cylindrical one cut from a round bar material. It is necessary to open the window 11 by machining (powder cutting, milling, electric discharge machining, etc.), which causes a problem in that the manufacturing cost of the cage 7 itself increases.

Also, when reducing the size with an inner valve, the window 11
Because the area of the cage was changed, it was necessary to manufacture cages with different window shapes for each size (all other dimensions were the same), making it troublesome to manage the types in stock.

[Means for solving problems]

The cage valve according to the present invention has been made in view of the above-mentioned points, and includes a seat ring disposed in a through hole of a partition wall provided in the valve body, and a seat ring coaxially with the valve body. A cage disposed inside the cage, and a cup-shaped plug slidably disposed within the cage and seated on the seat ring when fully closed, with a coil spring interposed between the cage and the seat ring. It is configured with a

[Effect]

In the present invention, the gap between each coil of the coil spring is used as a characteristic window, so there is no need to provide a window in the cage.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIGS. 1a and 1b are a longitudinal cross-sectional view and an enlarged cross-sectional view of essential parts, respectively, showing an embodiment of a cage valve according to the present invention.
In the figure, the same or equivalent components as those in FIG. 5 are designated by the same reference numerals, and the explanation thereof will be omitted. In the figure, the seat ring 8 is fitted into a through hole 20 provided in the partition wall 2 via an O-ring 21. A cage 7 coaxially disposed with respect to the seat ring 8 is fitted into the upper opening 22 of the valve body 1, and a flange 23 integrally provided on the outer periphery of the cage 7 is connected to the valve body 1 by the upper lid 6. The seat ring 8 is press-fixed to the upper surface, and an appropriate gap is provided between the inner end and the seat ring 8. and,
A coil spring 25 forming a specific window portion 30 is interposed in this gap. Therefore, the cage 7 is simply formed into a straight cylindrical shape, does not have the window 11 shown in FIG. 5, and has a substantially cup-shaped plug 14 slidably fitted therein.

By disposing the coil spring 25 in a compressed state, the compression reaction force causes the seat ring 8 to
is urged downward and the cage 7 is urged upward. Annular projections 27 and 28 are integrally provided on the upper surface of the seat ring 8 and the inner end surface of the cage 7, respectively, and these annular projections 27 and 28 position the coil spring 25 and connect the spring 25 and the plug. Contact with 14 is prevented.

In such a configuration, when the plug 14 moves up and down as the valve stem 13 moves up and down, the opening area of the specific window 30 between the seat ring 8 and the cage 7 formed by the coil spring 25 changes. The flow rate of the controlled fluid flowing from the upstream flow path 3 to the downstream flow path 4 through the characteristic window 30, that is, between the coils of the coil spring 25 and through the center hole 31 of the seat ring 8, can be controlled. By changing the pitch of the spring 25, etc., desired flow characteristics can be obtained. In addition, since the cage 7 itself does not have a characteristic window, there is no need to manufacture it by casting or special machining.
It can be manufactured at low cost by cutting with a lathe or the like. Furthermore, downsizing by using an inner valve is possible by simply changing the number of turns, pitch, or wire diameter of the coil spring 25 that forms the characteristic window 30, instead of making the entire cage 7 as in the past (only changing the shape of the window). This makes it possible to downsize at a low cost. In addition, in the case of high-temperature use, in the conventional structure shown in FIG. 5, the elongation of the cage 7 due to thermal expansion causes distortion of the inner diameter of the cage, which may cause galling with the valve plug 14. Therefore, for high temperature specifications, a two-part cage may be used. In this respect, the present invention employs a structure similar to the two-part cage system in which the cage 7 and the seat ring 8 are separated, so that it can be used satisfactorily even in high-temperature specifications.

FIGS. 2a and 2b are cross-sectional views showing another embodiment of the present invention. In this embodiment, the through hole 20 of the partition wall 2 is a screw hole, and the seat ring 8 is screwed into the through hole 20. Therefore, the coil spring 25 does not need to be assembled in a compressed state. However, to prevent the spring 25 from wobbling, it is desirable to install it in a somewhat compressed state. Further, in the method of screwing the seat ring 8 into the through hole 20, the more the seat ring 8 is tightened, the more the surface pressure of the seat ring 8 can be increased, so sealing parts such as gaskets and O-rings are not required. In this type of screw-in method, the primary pressure can be up to 100Kg/cm ² as a differential pressure.
Can be used for fluid specifications up to 40Kg/ ^cm2 .

Note that the other configurations are almost the same as those of the embodiment shown in FIG. 1, and therefore description thereof will be omitted.

FIG. 3 is an enlarged sectional view of main parts showing another embodiment of the present invention. In the embodiment shown in FIG. 1, the cage 7 is simply pressed by the upper lid 6, so when the upper lid 6 is removed, the cage 7 will not pop out from the upper opening 22 of the valve body 1 due to the compression reaction force of the coil spring 25. is possible. Therefore, in this embodiment, in order to prevent this, the collar 23 of the cage 7 is fixed to the upper surface of the valve body 1 with bolts 40 via a gasket 41. Further, the method for preventing the cage 7 from popping out is not limited to the screw fixing method, and a retaining ring 45 as shown in FIG. 4 may be used.

Note that the plug is omitted in FIGS. 3 and 4.

[Effect of idea]

As explained above, the cage valve according to the present invention is
Since the seat ring and the cage are spaced apart from each other and arranged coaxially, and a coil spring is arranged between these two members to form a characteristic window, there is no need to provide a characteristic window in the cage itself. There is no need to manufacture it by casting or special machining, and it can be manufactured at low cost. In addition, since a coil spring is used, it is easy to change the characteristic window, there is no need to replace the cage, the size can be reduced inexpensively by using an inner valve, and it can withstand high temperature specifications, making it practical. The effect is very large.

[Brief explanation of the drawing]

Figures 1a and b are a longitudinal sectional view and an enlarged sectional view of essential parts showing one embodiment of the cage valve according to the present invention, Figure 2 is a longitudinal sectional view showing another embodiment of the invention, and Figure 3 is a longitudinal sectional view showing an embodiment of the cage valve according to the present invention. A fourth enlarged sectional view of main parts showing another embodiment of the present invention.
The figure is an enlarged sectional view of a main part showing still another embodiment of the present invention, and FIG. 5 is a sectional view showing an example of a conventional cage valve. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Partition wall, 3... Upstream flow path, 4... Downstream flow path, 6... Top cover, 7... Cage, 8... Seat ring, 14... Plug, 20
...Through hole, 25...Coil spring, 30...
Characteristic window.

Claims (1)

[Scope of utility model registration request] A seat ring disposed in a through hole of a partition wall provided in the valve body and partitioning into an upstream flow path and a downstream flow path, and a cage coaxially disposed in the valve body facing the seat ring. and a cup-shaped plug that is slidably disposed within the cage and seats on the seat ring when fully closed, and a coil spring is interposed between the cage and the seat ring. cage valve.