JPS6283564A - Cage type regulating valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cage-type control valve having a valve structure that takes into consideration high-temperature fluid as the fluid to be controlled.

[Conventional technology]

In general, cage-type control valves designed for high-temperature fluids are thermally insulated, but it is unavoidable that a temperature difference will occur between the valve body and trim parts during use, and the cage material is subject to thermal expansion. The coefficient of thermal expansion is often larger than that of the valve body, and for this reason, strict conditions are required when manufacturing the valve.

Conventionally, this type of cage-type control valve has a so-called split cage structure consisting of two cages, an upper cage and an upper cage.

In other words, if the cage is not divided, thermal stress caused by the difference in thermal expansion will act on the stud bolts used to fix the cage to the valve body and on the gasket interposed between the cage and the valve body, resulting in damage to the gasket and damage to the seal. This is because the effectiveness may be reduced or the cage itself may become deformed, causing malfunction.

FIG. 6 is a cross-sectional view showing a conventional cage-type control valve. In the figure, the valve body designated by reference numeral 1 has compartments 3 and 4 that are partitioned into upper and lower sections by a partition wall 2, and both corner compartments 3, 4 are opened on both sides by a supply port 5 and a discharge port 6, respectively. Further, the partition wall 2 of the valve body 1 is provided with the corner chambers 3 and 4.
A screw hole 7 is formed through which the screw holes 7 communicate with each other, and a stepped portion 8 is provided at the opening periphery of the screw hole 7. Reference numerals 9 and 10 are two upper and lower cages formed in a cylindrical shape, and are connected to both corner chambers 3.
, 4 is housed in the upper compartment 3. A portion of the upper cage 9 of these cages 9 and 10 is in contact with a step 11 provided on the wall of the compartment 3 via a gasket 12, and a valve seat 13 is provided inside. . A portion of the lower cage 10 is in contact with the stepped portion 8 via a gasket 14 and is screwed into the screw hole 7.

Further, a flow rate control window 15 is bored in the lower cage peripheral wall, and a valve seat 16 having a diameter smaller than the diameter of the valve seat 13 is provided below this window 15. ]
7 is a seating portion 18 that can be seated on each of the valve seats 13 and 16.
．． The valve plug 19 is disposed in the cages 9 and 10 so as to be movable back and forth, and is configured to control the flow rate by raising and lowering the valve shaft 20. 21 is an upper cover having a function of slidably supporting the valve shaft 20;
The upper cage 9 is fixed to the valve body 1 by bolts 22 through a packing 23, thereby fixing the upper cage 9 to the valve body 1.

[Problem that the invention seeks to solve]

However, in the conventional cage-type control valve, both cages 9 and 10 are fixed separately within the valve body 1, so that after thermal expansion, the valve seat 13 of the upper cage 9 moves downward and the valve seat 13 of the lower cage 10 moves downward. By moving the valve seat 16 upward, both valve seats 1
Although the pitch P between 3 and 16 becomes smaller than the pinch before thermal expansion, the valve plug 17 expands freely and the pitch P2 between the rain seating parts 18 and 19 increases, and the pitch deviation causes the valve to close. At times, there was a problem that the amount of fluid leakage increased.

Further, the cage-divided structure has a problem in that the number of parts is bulky and the valve assembly operation is complicated.

[Means for solving problems]

The cage-type control valve according to the present invention has a circumferentially inclined bridge in the cage by forming an opening between the upper valve seat of two large and small valve seats with different diameters and the flow rate control window. The parts are integrated.

The present invention was developed in view of the above circumstances, and it is possible to simplify the valve assembly work, reduce the amount of fluid leakage when the valve is closed, and prevent malfunctions due to cage deformation. To provide a cage type control valve that can prevent

[For production]

In the present invention, even if the thermal expansion of the cage is larger than that of the valve body, the bridge portion can be elastically deformed to absorb the difference in thermal expansion.

〔Example〕

FIG. 1 is a cross-sectional view showing a cage type control valve according to the present invention, and FIG. 2 is a cross-sectional view showing an enlarged main part thereof. In the figure, what is indicated by the reference numeral 31 is the valve body, and there is a partition wall 32 inside.
It has compartments 33, 34 which are partitioned into upper and lower parts by , and both corner chambers 33, 34 are opened on both sides by a supply port 35 and a discharge port 36, respectively. Further, a communication hole 37 is formed in the partition wall 32 of the valve body 31, through which both the corner chambers 33 and 34 communicate with each other, and a stepped portion 3 is formed on the opening periphery of the communication hole 37.
8 is provided. Reference numeral 39 denotes a cylindrical cage, a part of which faces the stepped portion 38 via a gasket 40, and is housed in the upper compartment 33 of the corner chambers 33 and 34. This cage 39 has a plurality of flow control windows 41 on the peripheral wall,
41. ... are drilled, and these multiple windows 4
．． 1,41. Two large and small valve seats 42 and 43 with different diameters are provided above and below. 44,4
4. . . are a number of bridge portions inclined in the circumferential direction, and the flow rate control windows 41, 41 . ...and both valve seats 4
A large number of openings 4 are provided between the valve seat 42 on the upper side of 2°43.
5.45. ... is integrally provided in the cage 39, and is configured to be elastically deformable in the axial direction of the cage. 46 is both the valve seats 42
, 43. The valve plug has seating portions 47 and 48 that can be seated on the valve shafts 47 and 43, and is disposed in the cage 39 so as to be able to move forward and backward, and is configured to control the flow rate by moving the valve shaft 49 up and down. Reference numeral 50 denotes an upper cover having the function of slidably supporting the valve shaft 49, and is fixed to the valve body 31 with a stud bolt 51 via a gasket 52.
This fixes the cage 39 to the valve body 31. Note that 53 and 54 are annular grooves (Japanese Utility Model Publication No. 51-29559) that open into the cage 39, and the openings 45, 45. ... and the upper valve seat 42, and between the openings 45, 45°... and the flow rate control windows 41, 41.
. . . are respectively formed between the flow rate control windows 41, 41 . The fluid passing through can flow smoothly. 55 is a through hole that communicates between the top and bottom of the plug,
A load is provided in the valve plug 46 to reduce the pressure difference generated between the upper and lower sides, and to act on a drive unit (not shown) disposed at a separated position via the valve shaft 49. is decreasing.

Note that the bridge portions 44, 44. In order to give these gaskets 40.52 an elasticity value that does not exceed the appropriate range, the wall thickness, number of inclination angles 61, and length are appropriately set. In addition, the pitch between both valve seats 42 and 43 is also set in consideration of the appropriate tightening force to the gasket 40°52, so that after the valve is assembled, both seating parts 47 and 48
Match the pitch between.

In the cage type control valve configured in this way, even if the thermal expansion of the cage 39 is larger than the thermal expansion of the valve body 31, the bridge portions 44, 44. ... can be elastically deformed to absorb the difference in thermal expansion.

Therefore, even if a thermal expansion difference occurs between the valve body 31 and the cage 39 due to the flow of high-temperature fluid inside the valve body 31, the pitch between the valve seats 42 and 43 and the pitch between the seat parts 47 and 48 Not only does it stay in place, but it also keeps it in place (gasken) 4
0.52 is within an appropriate range and will not be compressed and damaged, and the cage 39 will not be deformed to the extent that it will affect the operation of the valve.

In addition, since the cage 39 is not structured to be screwed into the partition wall 32 as in the past, special tools for threading and cage assembly are not required, reducing costs. 40 does not undergo rotational wear as in the conventional case, a stable sealing effect can be obtained.

Furthermore, sliding of the valve plug 46 causes the bridging portion 44.
44. The scale attached to the valve plug 46 is scraped off at the corners.

In addition, in this embodiment, the bridge portions 44, 44°...
Although the present invention is not limited to this, the present invention is not limited to this, and as shown in FIG. 3 and FIG. 56,
56. ... or 57°57, etc.

In this case, the bridge portions 56, 56 . . . . has a ■-shaped opening 58, and bridge portions 57, 57 . . . . connects the W-shaped opening 59 to the upper valve seat 42 and the flow rate control windows 41, 41.
．． . . . are formed integrally with the cage 39. For this reason, the bridging portion 56,
57 is not twisted during its deformation, and the elastic displacement of the bridge portions 56 and 57 can be increased.

Further, in the present invention, as shown in FIG. 5, a so-called spring-shaped bridge portion 60 can also produce the same effect as the embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, by forming an opening between the upper valve seat of the two valve seats with different diameters and the flow rate control window, the cage is tilted in the circumferential direction. Since the bridging portion is integrally provided, even if the thermal expansion of the cage is larger than that of the valve body, the bridging portion can be elastically deformed to absorb the difference in thermal expansion. Therefore, even if a thermal expansion difference occurs between the valve body and the cage due to the flow of high-temperature fluid inside the valve body, the pitch between the valve seats and the pinch between the rain seats may shift, and the gasket may be damaged due to compression. In addition, the cage does not deform to the extent that it affects the operation of the valve, and the amount of fluid leakage when the valve is closed can be reliably reduced, and sealing performance can be maintained for a long period of time. It is possible to prevent malfunctions due to cage deformation. Furthermore, since the cage is not of the split type as in the conventional case, the number of parts can be reduced and the valve assembly work can be simplified.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a cage-type control valve according to the present invention, FIG. 2 is a cross-sectional view showing an enlarged main part thereof, and FIGS. 3, 4, and 5 show other embodiments. 6 is a sectional view showing a conventional cage type control valve. 39...Cage, 41...Flow rate control window, 42
．． 43... Valve seat, 44... Bridge section, 45...
・Opening, 46...Valve plug, 47.48...
Seating area.

Claims (1)

[Claims] A cylindrical cage having a flow rate control window bored in its peripheral wall, two valve seats of different diameters arranged above and below the window, and both valves disposed in the cage so as to be able to move forward and backward. and a valve plug having a seating portion that can be seated on each seat, and an opening is formed between the upper valve seat of the two valve seats and the flow rate control window, so that the cage is provided with a valve plug that extends in the circumferential direction. A cage-type control valve characterized by having an integrally inclined bridge section.