JPH073272B2 - Valve assembly for controlling liquid flow - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a valve for controlling a liquid flow, and more particularly to a valve device having cavitation preventing means.

[Prior art]

Conventionally, in a pilot valve or the like operated by a solenoid, a phenomenon called cavitation occurs when the valve is used for a liquid that is not degassed. Cavitation occurs when the liquid rapidly flows and partially creates bubbles (the bubbles later collapse). Such a sudden flow occurs when the liquid pressure drops below the vapor pressure,
Further, the collapse of bubbles occurs when the liquid pressure returns to the vapor pressure or more. When cavitation occurs, it lowers the efficiency of the fluid machine and causes corrosion, noise, and impedes the flow of liquid.
It is known that in a valve device, cavitation occurs by causing a rapid pressure drop such that a liquid pressure becomes lower than a vapor pressure around an opened valve. Further, cavitation is likely to occur especially in the case of a pilot valve operated by a solenoid that repeatedly opens and closes at 537 ° C (1000 ° F) and 700 kg / cm ² (10,000 psi) or more.

[Problems to be solved by the invention]

Eliminating cavitation in solenoid operated pilot valves is difficult because such pilot valves have an extremely small travel distance compared to conventional switching valves. This unwanted cavitation phenomenon can be substantially eliminated by the valve device of the present invention. It is an object of the present invention to provide a liquid flow control valve device which is substantially free of cavitation. Another object of the present invention is to provide a liquid flow control valve device that is less susceptible to corrosion and less noisy during operation than conventional known liquid flow control valve devices. Yet another object of the present invention is to provide a valve device for liquid flow control in which liquid flows relatively freely.

[Means for solving problems]

The present invention for achieving the above object is a valve device for liquid flow control, and in its broad concept, an inlet communicating with a liquid source,
An outlet for discharging the liquid from the valve device, and at least one valve seat provided between the inlet and the outlet. A movable valve member is provided in the valve body, and the movable valve member is provided between a position at which the movable valve member is seated on the valve seat and a fully open position at which the liquid valve member is separated from the valve seat so as to prevent the liquid from flowing from the inflow port to the outflow port. The liquid reciprocates over and the liquid flows from the inflow port to the outflow port. An opening means is provided between the inflow port and the valve seat, and the opening means cooperates with the movable valve member to form a variable liquid flow path throttle that is directly proportional to the variable flow path between the movable valve member and the valve seat.

In a narrow concept of the invention, the opening means comprises a stationary sleeve having a movable valve member therein which reciprocates in a spaced-apart and close manner relative to the valve seat, and having a plurality of circumferentially spaced holes. Including. The flow passage cross-sectional area of the opening means varies in size according to the position of the movable valve member that is spaced apart from and close to the valve seat. The opening means also includes a hole disposed on the valve body and downstream of the valve seat;
A movable valve member extending beyond the valve seat into the hole and slidably movable with respect to the hole. The extending portion of the movable valve member has at least one second portion between the end portion of the hole and the extending portion.
Is formed so that the size of the fluid flow passage is changed in direct proportion to the distance at which the movable valve member is separated from the valve seat. The first and second opening means cooperate with the movable valve member and the valve seat to cause a continuous and relatively small amount of pressure drop, and in each opening means, the hydraulic pressure is equal to or lower than the evaporation pressure of the liquid at the inlet of the valve body. To prevent the drop. Therefore, the above can reduce the possibility of occurrence of the cavitation phenomenon.

A feature of the present invention is that the movable valve member is a disk-shaped body that is slidable in the stationary sleeve, and has first and second reduced diameter portions. The first reduced diameter portion is formed so as to be seated on the valve seat, and a diametrical groove of the second reduced diameter portion is formed to form an end portion of a hole into which the second reduced diameter portion is slidably fitted. Together they form a variable opening to the end of the sequential pressure drop of the liquid flowing from the inlet towards the outlet.

In an embodiment of the invention, a stationary sleeve is formed spaced apart from the first reduced diameter portion of the disk-shaped body to form an annular space in which the helical spring is to be placed, the coil of the helical spring being A plurality of narrowed portions of the variable liquid flow path are formed by the gaps therebetween. The spiral spring is in contact with the disk-shaped body, and is formed so that the gap between the coils changes when the disk-shaped body moves. Therefore, when the distance from the position where the first reduced diameter portion of the disk-shaped member is seated on the valve seat changes, the plurality of parallel openings change the flow passage cross-sectional area in direct proportion to the distance.

〔Example〕

 The present invention will be described in detail below with reference to the accompanying drawings.

In particular, as shown in FIGS. 1 and 2, reference numeral 10 generally indicates a valve device according to the first embodiment of the present invention.
In the present specification, a pilot valve for adjusting type liquid flow control in which the valve device 10 is operated by a solenoid will be described. The present invention is particularly, but not necessarily, suitable for solenoid operated control valves.

Accordingly, the present invention will be described below with reference to a solenoid-operated pilot valve for controlling a regulated liquid flow. However, the present invention is applicable to many liquid flow control valves, especially for high-temperature and high-pressure liquids having a small valve travel distance. It is applicable to small control valves without departing from the scope and spirit of the invention.

The valve device shown in FIGS. 1 and 2 includes a valve body 12 in which a fluid channel 14 is formed, and an inlet 16 is provided at one end of the liquid channel 14.
However, an outflow port 18 is provided at the other end on the opposite side. A main valve seat 20 is provided in the liquid flow path 14 between the inflow port 16 and the outflow port 18. A portion of the liquid flow passage 14 upstream of the main valve seat 20 is referred to as an inflow passage 14a, and a portion of the liquid flow passage downstream of the main valve seat 20 is an outflow passage 14b.
Called. The valve member 22 (also called the main disc) is the valve body 12
Is provided for reciprocating movement within the main valve member 22
Abutting against the valve seat 20 prevents the liquid from flowing in the liquid flow passage 14, and the main valve member 22 makes a maximum distance from the valve seat 20 to fully open the liquid flow passage 14. Since this valve device 10 is a solenoid operated valve,
A pilot valve 24 is provided in the hole of the main valve member 22 so as to reciprocate. Electromagnet device 27 is bonnet device 28
Supported above. The bonnet device 28 is integrally connected to the valve body 12. Normally, the bonnet device 28 has a valve body 12
A long non-magnetic tubular member 30 positioned at the open end 32 of the cylindrical portion 34 of the cylindrical portion 34, the cylindrical portion 34 extending at an angle to the valve portion through which the flow passage 14 extends. ing. The tubular member 30 is provided in the cylindrical portion 34 so as to be spaced from the valve seat 20 and coaxial with the valve seat 20.

Upon operation of the valve device 10, the liquid supplied from the supply source (not shown) to the flow path 14 through the inflow port 16 enters the valve through the small hole flow paths 25 and 26 and the pilot valve 24. And main valve member 22
Exerts inflow pressure on all surfaces of. The spring 42 and the return spring 44 urge the pilot valve 24 and the main valve member 22 toward the closed position shown. When it is desired to open the main valve member 22, the electromagnet device 27 is appropriately biased by an electric power source (not shown). The magnetic flux generated by this bias moves the armature 38 in the axial direction against the force of the return spring 44. The axial movement of the armature 38 against the biasing force of the return spring 44 causes the pilot valve 24 to move away from the valve seat without affecting the main valve member 22. This is because there is play between the pin 48 and its associated slot 46 and between the armature pin 49 and its associated slot 50, respectively.
Due to the subsequent biasing of the electromagnet device and the axial movement of the armature, the main valve member 22 is moved to the fully open position due to the pressure difference across the valve member. The pressure difference across the main valve member 22 is due to the pilot valve connecting the inside of the valve with the outlet 18.
It is generated by opening 24, and the main valve member 22
The liquid pressure acting on the valve decreases as it moves toward the valve seat 20.
Therefore, the resultant force of the hydraulic pressure acting on the surface 52 through the small hole passage 25 of the stationary sleeve 56 and the hydraulic pressure acting on the opposite surface of the main valve member 22 causes the main valve member 22 to move the main valve member. Acts away from the valve seat. Once the hydraulic pressure across the main valve member 22 reaches an equilibrium state, a pressure difference is generated across the main valve member 22 due to a change in hydraulic pressure in the inflow passage or the outflow passage, and movement in response to such a pressure difference occurs. . Large and sudden pressure drops in the liquid flowing through the valve seat 20 into the outflow passage 14b and the resulting cavitation are prevented by the valve device 10 of the present invention, which is described in detail below.

As shown in FIG. 2, the main valve member 22 of the valve device 10 has a cylindrical portion.
58, a first reduced diameter portion 60, and a second reduced diameter portion 62,
The end of the reduced diameter portion is formed in a shape and size suitable for seating on the valve seat 20. The main valve member 22 also includes a third reduced diameter portion 64 and an enlarged diameter end portion 66. The stationary sleeve 56 disposed between the open end 32 of the tubular member 30 and the valve seat 20 serves as the portion 5 of the main valve member 22.
The outer peripheral surfaces of 8, 60 are formed so as to slide on the inner peripheral surface of the sleeve 56. The valve seat 20 is formed along the inner edge of the ring member 68 attached to the valve body 12 of the valve device 10 by appropriate means. An annular inner surface 74 is formed on the inner surface of the ring member 68 by reducing the diameter of the concave hole portion 70 having a large-diameter annular inner surface. The annular inner surface 74 slidably engages with the outer peripheral surface of the enlarged diameter end portion 66 of the main valve member 22. An annular second inflow chamber 76 is defined by the annular inner surfaces of the second and third reduced diameter portions 62, 64, the enlarged diameter end portion 66 and the recessed hole portion 70. A diametrical groove 78 is formed in the enlarged diameter end 66 of the main valve member 22. The groove 78 cooperates with the upper edge 80 of the annular inner surface 74 to define an orifice of variable variable flow cross-section that connects the second inflow chamber 76 to the outflow passage 14b.

The stationary sleeve 56 includes a reduced diameter end portion 82, the inner peripheral surface of which is slidably engaged with the first reduced diameter portion 60 of the main valve member 22. The space between the first reduced diameter portion 60 and the stationary sleeve 56 is sealed with an O-ring 81, and the facing surface between the portion 58 of the main valve member 22 and the stationary sleeve 56 is sealed with an O-ring 83. Reduced end
A plurality of holes 84 are provided in 82 at intervals in the circumferential direction. These holes 84 cooperate with the first reduced diameter end 60 of the main valve member 22,
The inflow passage 14a is connected to the reduced diameter end portion 82 of the sleeve 56 and the ring member 68.
And the annular space 88 formed by the first and second reduced diameter portions 60, 62 of the main valve member 22.

In operation, the orifice formed by the hole 84 and the edge portion 86 of the main valve member 22 acts as a first variable flow restrictor upstream of the valve seat 20, with the groove 78 and the edge portion 80. The formed orifice acts as a second variable flow restrictor downstream of the valve seat. The first and second variable flow restrictors are used for the inflow passage 14a.
Since the dimensions are determined in relation to the predetermined total pressure drop of the liquid from the outlet flow passage 14b to the outflow passage 14b, the pressure drop can be achieved without lowering the liquid pressure below the vapor pressure in each of the first and second variable flow restrictors. Therefore, the cavitation phenomenon can be prevented. The throttle cross-sectional areas in the first and second variable flow throttle devices are directly proportional to the movement of the main valve member 22 that approaches and separates from the valve seat 20. Therefore, the valve device 10 changes the pressure difference between the liquids in the inflow passage 14a and the outflow passage 14b to prevent cavitation.

FIG. 3 shows a second embodiment of the valve device of the present invention. Valve device 90
The first variable flow restrictor is formed by a spring 92 in which the first reduced diameter portion 60 and the hole 84 of the main valve member 22 described in the valve device 10 of the first embodiment are wound in a spiral shape instead of the cooperative action. The only difference is that the device is formed. Therefore, parts of the valve device 90 that are similar to parts of the valve device 10 are designated by the same reference numerals with an A attached.

As shown in FIG. 3, the stationary sleeve 56A does not have a diameter-reducing end portion 82 unlike the stationary sleeve 56, but is formed to have a substantially uniform diameter, and the inner peripheral surface of the stationary sleeve 56A and the first diameter reduction. Part 60A
An annular space 94 is formed between the outer peripheral portions of the. A helical spring 92, preferably of rectangular cross section, is arranged in the annular space 94. When the main valve member 22 moves between the fully open and fully closed positions, the gap between the adjacent spring coils moves in direct proportion to the movement of the main valve member 22A. The gap 96 is connected to the spring 9 through the hole 84A.
Of the variable flow restrictor that communicates the area inside the annular space 94 formed between the inner peripheral surface of the second coil and the first reduced diameter portion 60A of the main valve member 22A and the annular space 88A with the inflow passage 14aA. Work hard.

The valve device 90 operates similarly to the valve device 10, and continuously controls the pressure drop of the liquid flow between the inflow passage 14aA and the outflow passage 14bA,
Cavitation is eliminated because the vapor pressure does not drop below the vapor pressure at the valve seat 20A.

〔The invention's effect〕

The present invention can provide a novel valve device that can be used with non-degassed liquids to reduce or completely eliminate the occurrence of cavitation. Since the valve device of the present invention is less likely to be corroded and damaged, it is quiet in operation and can be used for a long period of time. The present invention can also provide a solenoid operated control valve that eliminates the occurrence of cavitation.

The invention is not limited to the drawings and the description. The drawings and the description above are for the purpose of representing the concept and principle of the present invention, and those skilled in the art can arbitrarily change them within the scope of the disclosure of the present invention. Also, the drawings are not drawn to scale and are rather exaggerated for clarity. Thus, while the preferred embodiment has been illustrated herein, various modifications may be made without departing from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view of a valve device showing a first embodiment of the present invention, FIG. 2 is an enlarged view of a partial cutaway showing an essential part of FIG. 1, and FIG. 3 shows a second embodiment of the present invention. It is a figure similar to FIG. 10 ... Valve device, 12, 12A ... Valve element, 16 ... Inlet, 18 ...
… Outlet, 20 …… Valve seat, 22,22A …… Main valve member, 56,56A…
… Stationary sleeve, 60 …… First part, 62 …… Reduced diameter part, 66 …… Second reduced diameter part, 74 …… Hole, 78 …… Groove, 80 ……
The end of the hole, 84, 84A ... hole, 92 ... spiral spring, 94 ... annular space.

Claims (3)

[Claims] 1. A valve assembly for controlling the flow of a liquid, the valve assembly comprising: (a) an inlet (16) communicating with a liquid source and an outlet (18) for passing the liquid from the valve assembly. Body (12)
(B) at least one valve seat (20) provided in the main body portion (56) of the valve body (12) between the inflow port (16) and the outflow port (18), and (c) A cylindrical main valve member (22) that is movable in the axial direction, and (i) is provided in the main body portion (56) of the valve body and extends from the inflow port (16) to the outflow port (18). Reciprocating between a position in contact with the valve seat (20) so as to prevent flow and a fully open position away from the valve seat (20) so as to flow fluid from the inflow port (16) to the outflow port (18) Valve seat engaging portion (62)
(Ii) is provided on the inlet side of the valve seat engaging portion (62) and has a diameter larger than that of the valve seat engaging portion (62), and together with a part (82) of the main body portion, the first chamber ( A second flow control cylindrical portion (60) which defines and defines (88), and (iii) is provided on the outlet side of the valve seat engaging portion (62) and is smaller than the valve seat engaging portion (62). A valve seat (20) and a valve seat engaging portion (62) having a diameter and a portion (68) of the body portion
A second chamber (76) separated from the first chamber (88) by and
An axially movable cylindrical main valve member (22) having a third flow control cylindrical portion (64) partitioning and forming (d) the inlet (16) and the first chamber (88). ) In cooperation with the movable main valve member (22), the flow rate is directly proportional to the variable flow passage cross-sectional area between the valve seat engaging portion (62) and the valve seat (20). First opening means (84) for automatically changing the cross-sectional area of the road to variably control the flow of the liquid flowing into the first chamber (88); and (e) the outlet (18) and the first opening means (84). The valve seat engaging portion (62) and the valve seat (20) in cooperation with the third flow control cylindrical portion (64) of the main valve member (22) provided between the second chamber (76). The flow passage cross-sectional area is automatically changed in proportion to the variable flow passage cross-sectional area, and the fluid flow flowing out of the second chamber (76) is variably controlled to the extent that cavitation does not occur in the liquid. Second opening means (78) , A valve assembly for controlling the flow of liquid comprising :. 2. A main body portion of the valve body (12) is a stationary sleeve (56), and a main valve member (22) is arranged inside the sleeve so as to reciprocate, and the sleeve member (56). 56) multiple openings (8) spaced circumferentially
4), and the flow passage cross-sectional area of the opening (84) is the main valve member (2
2. The valve assembly according to claim 1, wherein the size of the valve assembly changes according to the position of 2) away from the valve seat (20). 3. A main valve body portion (22) in which a main body portion of the valve body (12) surrounds the main valve body portion (22A) and is spaced apart in a radial direction.
A) is provided with a stationary sleeve (56A) that defines an annular space (88A) between the sleeve (56A) and a plurality of openings (84A) provided at intervals in the circumferential direction, Further, the spiral spring (92) disposed in the annular space (88A) and connected to the main valve member (22A) is provided, and the spiral spring (92) moves as the main valve member (22A) moves. A plurality of flow paths from the inflow port (16) to the outflow port (18) are formed so as to approach and separate from each other and change the flow path cross-sectional area in proportion to the opened position of the main valve member (22A). A valve assembly as set forth in claim 1.