JPH0218470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cage valve having a function of preventing vibration of a valve plug sliding inside the cage.

[Prior art]

Conventionally, this type of cage valve has been constructed as shown in FIG. A hole is provided, and valve seats 4 and 5 having different diameters are provided above and below this window 3. Reference numeral 6 denotes a valve plug that slides in the vertical direction by a valve shaft 7, and is disposed in the cage 1 so as to be able to move forward and backward, and has seating portions 8 on its outer peripheral surface that can be seated on both the valve seats 4 and 5, respectively. 9 is provided. Thereby, the opening area of the fluid passage window 3 is changed to control the flow rate. Reference numeral 10 denotes a through hole that communicates between the upper and lower parts of the valve plug 6, which is bored in the upper part of the valve plug 6, thereby reducing the pressure difference generated on both the upper and lower sides, and separating the two through the valve shaft 7. This reduces the load on a drive unit (not shown) disposed at the location. Reference numeral 11 denotes an annular groove opening inside the cage 1, which is provided between the upper valve seat 4 and the window 3 on the inner peripheral surface of the cage 1, and is provided between the outer peripheral surface of the valve plug 6 on the inner peripheral surface of the cage 1. The structure is such that fluid entering the tank will not seep into the top due to a pressure drop. This prevents the valve plug 6 from vibrating within the cage 1.

However, in the conventional cage valve, although it is possible to prevent vibration of the valve plug 6 when the valve plug 6 is slightly raised at a small opening, when the valve plug 6 is fully opened or when the inner peripheral surface of the cage 1 and the outer periphery of the valve plug 6 There is a disadvantage that when fluid with a high differential pressure enters between the surfaces, vibration cannot be prevented.

[Summary of the invention]

The present invention was developed in view of the above circumstances, and has an extremely simple structure in which an internal through hole that penetrates an annular groove provided on the outer circumferential surface of the valve plug is bored in one side circumferential wall of the valve plug. The present invention provides a cage valve that can reliably prevent vibration of a valve plug. Hereinafter, the configuration and the like will be explained in detail by referring to embodiments shown in the drawings.

〔Example〕

FIG. 2 is a sectional view showing a cage valve according to the present invention;
FIG. 3 is a cross-sectional view of FIG. 2. In these figures, the same members as in FIG. 1 are denoted by the same reference numerals, and detailed explanations will be omitted. Reference numeral 21 denotes an annular groove whose groove bottom 22 faces the peripheral wall 2 of the cage 1, and is provided on the outer peripheral surface of the valve plug 6 and above the upper seating portion 8. Reference numeral 23 denotes an internal hole passing through the annular groove 21 into the valve plug 6, and is bored in the peripheral wall 24 of one side of the valve plug 6.

In the cage valve configured in this way, when the valve is opened, that is, when the valve seats 4, 5 and the seating parts 8, 9 are separated, after the fluid passes through the window 3, the space between the valve seat 5 and the seating parts 9 is a flow A that passes through and reaches the outlet 1a;
It passes through the gap between the outer peripheral surface of the valve plug 6 and the inner peripheral surface of the cage 1, flows between the valve seat 4 and the seating part 8, enters the upper cavity 23 of the valve plug 6, and enters the through hole 10. The flow passes through the valve plug 6 and is divided into a flow B that joins the flow A. At this time, a part of the flow B that has flowed into the valve plug 6 from the through hole 10 passes through the inner through hole 23 and flows into the gap 26 due to the pressure difference generated between the inside of the valve plug 6 and the gap 26 . This creates a pressure difference around the valve plug 6, which acts on the valve plug 6 in one direction.

Therefore, while the fluid is flowing through the gap between the valve plug 6 and the cage 1, even if there are pressure fluctuations in the fluid, the state of pressing the valve plug 6 in one direction is almost never released. do not have.

〔Effect of the invention〕

As explained above, according to the present invention, an annular groove is provided on the outer circumferential surface of the valve plug, and an internal through hole penetrating from the groove into the plug is bored in one side circumferential wall of the valve plug. The fluid pressure difference caused by the fluid entering the gap between the outer circumferential surface and the inner circumferential surface of the cage acts on the valve plug in one direction, thereby reliably preventing vibration of the valve plug within the cage.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional cage valve, FIG. 2 is a cross-sectional view of a cage valve according to the present invention, and FIG. 3 is a cross-sectional view of FIG. 2. 1...Cage, 2...Peripheral wall, 3...Fluid passage window,
4, 5... Valve seat, 6... Valve plug, 8, 9... Seating part,
21... Annular groove, 23... Inner hole, 24... Peripheral wall.

Claims (1)

[Claims] 1. A fluid passage window drilled in the peripheral wall, a cylindrical cage provided above and below this window and having valve seats of different diameters, and a cylindrical cage arranged so as to be movable forward and backward within this cage and seated on both said valve seats, respectively. A cage valve comprising a valve plug having a removable seating portion, wherein an annular groove is provided on the outer circumferential surface of the valve plug above the upper seating portion, and an inner passage passing from the groove into the plug. A cage valve characterized in that a hole is bored in one side peripheral wall of the valve plug.