A pilot-operated regulating valve

Abstract

When the cam is in the closed position, the cam is in the closed position, and the cam is in the closed position, so that the cam is in the closed position and the cam is in the closed position, so that the cam is in the open position and the cam is in the closed position, and the cam is in the open position, so that the cam is in the closed position and the cam is in the closed position, and the cam is in the closed position, so that the cam is in the closed position and the cam is in the closed position, and the cam is in the closed position, so that the cam is in the closed position and the cam is in the closed position, and the cam is in the closed position, so that the cam is in the closed position and the cam is in the closed position,

Description

Technical Field

[0001] The invention relates to a regulating valve, in particular to a pilot-operated regulating valve. Background Art

[0002] Pilot-operated control valves are primarily used in key locations within the petrochemical industry's automation control field. Their excellent sealing performance, high shutoff capability, wide applicability, and long service life have led to their increasing use in automatic control systems. This type of valve can be used as a vent control shutoff valve, particularly in high-temperature, high-pressure, and large-diameter applications requiring tight shutoff.

[0003] The existing pilot-operated control valve structure all uses a valve stem and a second valve core threaded connection. The second valve core slides up and down inside the first valve core. A cylindrical spring or butterfly spring is placed between the first and second valve cores to add preload. The preload is relatively large, about 1 / 3 of the actuator output thrust. If the spring preload weakens, it is very easy to cause high-frequency vibration of the first valve core under the impact of the fluid, because the first valve core is not fixedly connected to any parts. Another disadvantage of the existing pilot-operated control valve is that during the valve core closing process, the first valve core first contacts and seals with the valve seat. At this time, the valve has no flow to adjust. The second valve core continues to move downward to compress the spring before the second valve core can close. The same is true during the valve opening process. During this process, there will be a certain amount of displacement. Under this displacement, the valve cannot adjust the flow, that is, there is a dead zone for adjustment. Generally, this dead zone occupies 5%-10% of the entire stroke, which is not allowed in some occasions where high adjustment accuracy is required.

[0004] In summary, how to prevent the first valve core from vibrating at high frequencies during the closing process of the pilot valve has become an urgent problem that researchers in this field need to solve. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: how to prevent the first valve core from vibrating at high frequency during the closing process of the pilot valve;

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention is a pilot-operated regulating valve, comprising: a valve body, in which a fixed sleeve, a flow sleeve, and a valve seat are sequentially arranged from top to bottom; a first valve core, the top of which is fixedly connected to a valve stem and is slidably arranged in the flow sleeve by the control of the valve stem; a second valve core, which is slidably arranged in an inner cavity of the first valve core and suspended with the first valve core; an elastic member, which is arranged between the first valve core and the second valve core; when the valve body needs to be closed, the first valve core and the second valve core are driven downward by the valve stem, and the second valve core and the first valve core are successively pressed against the valve seat for sealing; when the valve body needs to be opened, the first valve core and the second valve core are driven upward by the valve stem, and the first valve core and the second valve core are successively separated from the valve seat;

[0008] In this solution, the first valve core is connected by a valve stem, driving the first valve core to move up and down in the flow sleeve, and the second valve core is slidably arranged in the first valve core, and the two are suspended and arranged, and an elastic member is provided between the first valve core and the second valve core; when the device needs to be closed, the valve stem moves downward, so that the second valve core, the first valve core and the valve seat are abutted against each other to achieve sealing; when the device is opened, the valve stem moves upward, and the first valve core moves upward driven by the valve stem. At this time, under the action of the elastic member, the second valve core is still abutted against the valve seat. When the first valve stem moves up a certain distance, the second valve core is disengaged from the valve seat; the movement of the first valve core in the flow sleeve changes the window area of ​​the flow sleeve to adjust the flow rate, and the impact force of the fluid acts on the outer wall of the first valve core. The first valve core is connected to the valve stem with a rigid thread, which has strong seismic performance and avoids high-frequency vibration of the first valve core;

[0009] In addition, the distance between the first valve core and the flow sleeve is the adjustment dead zone of the valve. The shorter the distance, the smaller the dead zone, and the stroke of the second valve core has no connection with the adjustment dead zone.

[0010] In order to facilitate the first valve core and the second valve core to be separated from the valve seat in sequence, the present invention further adopts a sealing cylinder protruding from the bottom of the inner cavity of the first valve core; a first balancing hole is opened on the second valve core; when the valve body is in the closed state, the sealing cover on the top of the first balancing hole is arranged on the sealing cylinder; when the valve body is in the open state, the first balancing hole is separated from the sealing cylinder;

[0011] In this solution, since the second valve core needs to move inside the first valve core, a sealing column and a first balancing hole are provided so that the circulating medium can enter the gap between the first and second valve cores, thereby facilitating the suction or discharge of the medium without affecting the relative movement between the first and second valve cores.

[0012] In order to facilitate the movement of the first valve core in the flow sleeve, the present invention adopts a second balancing hole opened on the side of the first valve core; a stroke cavity for the first valve core to move up and down is formed between the first valve core and the flow sleeve; the second balancing hole communicates with the valve body inlet and the stroke cavity;

[0013] The principle of the second balancing hole is consistent with that of the first balancing hole, and facilitates the up and down movement of the first valve core in the stroke chamber.

[0014] In order to illustrate the specific structure of the first valve core, the present invention adopts the first valve core including: a first cylinder, a first annular groove on the side wall of which is sealed and connected to the fixed sleeve and is installed with a metal sealing ring; a valve stem connecting hole, which is opened at the center of the top of the first cylinder and is threadedly connected to the end of the valve stem; a second cylinder, an outer diameter of which is larger than the outer diameter of the first cylinder, and is consistent with the inner diameter of the flow sleeve and the outer diameter of the second cylinder; the outer diameter of the first cylinder is equal to the inner diameter of the second cylinder.

[0015] A metal sealing ring is installed in the first annular groove and is sealed and slidably connected to the fixed sleeve. The outer diameter of the second cylinder is equal to the inner diameter of the flow sleeve, so that the flow rate can be adjusted. The outer diameter of the first cylinder is smaller than the outer diameter of the second cylinder and is equal to the inner diameter of the second cylinder. The purpose of this setting is to eliminate the area difference between the two, thereby eliminating the unbalanced force generated by the fluid on the outer cylindrical surface of the first valve core.

[0016] How to achieve the installation of the elastic member and the suspension connection of the first and second valve cores? The present invention adopts a method in which the top of the first valve core is provided with a mounting hole and a balancing step hole at intervals in an annular manner; the top of the second valve core is provided with a threaded blind hole and an elastic member mounting hole at intervals in an annular manner; a bolt passes through the mounting hole and is fixedly connected to the threaded blind hole; the elastic member is located in the balancing step hole and the elastic member mounting hole; when the valve body is in the closed state, a gap is provided between the bolt head and the bottom wall of the mounting hole;

[0017] The elastic part is installed in the step balancing hole and the elastic part mounting hole. The first and second valve cores are connected by bolts. When the valve body is in the open state, the head of the bolt is against the bottom of the mounting hole; when the valve body is in the closed state, there is a gap between the head of the bolt and the mounting hole.

[0018] In order to illustrate the specific structure of the second valve core, the present invention adopts a second annular groove on the outer wall of the second valve core that is sealed to the side wall of the inner cavity and is installed with a metal sealing ring.

[0019] A metal sealing ring is installed in the second annular groove to achieve a sealed connection between the first valve core and the second valve core.

[0020] In order to realize the sealed connection between the second valve core and the valve seat, the present invention adopts a method of providing a sealing slope on the side wall of the bottom of the second valve core, wherein the sealing slope abuts against the first slope provided on the inner ring of the valve seat for sealing.

[0021] When the sealing inclined surface at the bottom of the second valve core abuts against the first inclined surface of the valve seat, the second valve core and the valve seat are sealed against each other.

[0022] In order to realize that the second valve core only performs a sealing function, the present invention adopts that when the valve body is in the open state, the bottom plane of the second valve core is not higher than the bottom plane of the first valve core;

[0023] The purpose of this design is that when the fluid passes through the window of the flow sleeve, the impact force of the medium acts entirely on the outer wall of the first valve core, and the second valve core is not impacted by the medium and only plays a role of sealing and cutting.

[0024] To illustrate the specific structure of the valve seat, the present invention adopts a valve seat having a first step surface for fixing the bottom of the flow sleeve and a second step surface abutting against the bottom wall of the first valve core; an annular groove is formed at the bottom of the valve seat, in which a sealing ring is installed to seal the valve seat;

[0025] The first step surface cooperates with the flow sleeve for positioning, the second step surface cooperates with the inner hole of the first valve core, and an annular groove is designed at the bottom of the valve seat for installing a sealing ring and contacting the valve body to play a sealing role.

[0026] When the valve is required to open, the first valve core moves upward under the drive of the valve stem, and the pressure in the upper chamber of the first valve core passes through the second balancing hole to balance the pressure in the upper and lower chambers of the first valve core. The actuator only needs a very small force to move the first valve core up and down, and the pressure in the upper chamber also acts on the upper surface of the second valve core through the balancing step hole so that the second valve core temporarily does not move with the first valve core. At this time, during the movement of the first valve core, the middle sealing column and the second balancing hole of the second valve core are disengaged, and the pressure is discharged through the second balancing hole of the second valve core until the pressure in the upper chamber of the first valve core and the pressure after the valve are completely balanced. When the first valve core continues to move upward, the end face of the bolt head contacts the mounting hole on the first valve core. At this time, the second valve core drives the first valve core to move upward together.

[0027] The beneficial effects of the present invention are as follows: the present invention is a pilot-operated regulating valve, the first valve core is connected by a valve stem, driving the first valve core to move up and down in the flow sleeve, and the second valve core is slidingly arranged in the first valve core, and the two are suspended and arranged, and an elastic member is arranged between the first valve core and the second valve core; when the device needs to be closed, the valve stem moves downward, so that the second valve core, the first valve core and the valve seat are abutted against each other to achieve sealing; when the device is opened, the valve stem moves upward, and the first valve core moves upward driven by the valve stem. At this time, under the action of the elastic member, the second valve core is still abutted against the valve seat. When the first valve stem moves up a certain distance, the second valve core is disengaged from the valve seat; the movement of the first valve core in the flow sleeve changes the window area of ​​the flow sleeve to adjust the flow, and the impact force of the fluid acts on the outer wall of the first valve core. The first valve core is connected to the valve stem with a rigid thread, which has strong seismic resistance and avoids high-frequency vibration of the first valve core. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and examples.

[0029] Figure 1 is a cross-sectional view of the present invention;

[0030] Figure 2 is a cross-sectional view of the sleeve of the present invention;

[0031] Figure 3 is a cross-sectional view of the first valve core;

[0032] Figure 4 is a cross-sectional view of the second valve core;

[0033] Figure 5 It is a cross-sectional view of the valve seat. DETAILED DESCRIPTION

[0034] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0035] like Figure 1-5 As shown, the present invention is a pilot-operated regulating valve, comprising: a valve body 1, in which a fixed sleeve 2, a flow sleeve 3, and a valve seat 4 are sequentially arranged from top to bottom; a first valve core 5, the top of which is fixedly connected to a valve stem 7 and is slidably arranged in the flow sleeve 3 controlled by the valve stem 7; a second valve core 6, which is slidably arranged in an inner cavity 8 of the first valve core 5 and is suspended with the first valve core 5; an elastic member 9, which is arranged between the first valve core 5 and the second valve core 6; when the valve body 1 needs to be closed, the first valve core 5 and the second valve core 6 are driven downward by the valve stem 7, and the second valve core 6 and the first valve core 5 are pressed against the valve seat 4 for sealing; when the valve body 1 needs to be opened, the first valve core 5 and the second valve core 6 are driven upward by the valve stem 7, and the first valve core 5 and the second valve core 6 are separated from the valve seat 4 in turn;

[0036] In this solution, the first valve core is connected by a valve stem, driving the first valve core to move up and down in the flow sleeve, and the second valve core is slidably arranged in the first valve core, and the two are suspended and arranged, and an elastic member is provided between the first valve core and the second valve core; when the device needs to be closed, the valve stem moves downward, so that the second valve core, the first valve core and the valve seat are abutted against each other to achieve sealing; when the device is opened, the valve stem moves upward, and the first valve core moves upward driven by the valve stem. At this time, under the action of the elastic member, the second valve core is still abutted against the valve seat. When the first valve stem moves up a certain distance, the second valve core is disengaged from the valve seat; the movement of the first valve core in the flow sleeve changes the window area of ​​the flow sleeve to adjust the flow rate, and the impact force of the fluid acts on the outer wall of the first valve core. The first valve core is connected to the valve stem with a rigid thread, which has strong seismic performance and avoids high-frequency vibration of the first valve core;

[0037] The elastic member applies a certain downward pressure to the second valve core, so that the second valve core is pressed against the valve seat and sealed.

[0038] In addition, the distance between the first valve core and the flow sleeve is the adjustment dead zone of the valve. The shorter the distance, the smaller the dead zone, and the stroke of the second valve core has no connection with the adjustment dead zone.

[0039] like Figure 3 、 4 As shown, in order to facilitate the first valve core and the second valve core to be separated from the valve seat in sequence, the present invention further adopts a sealing column 10 protruding from the bottom of the inner cavity of the first valve core 5; a first balancing hole 11 is opened on the second valve core 6; when the valve body 1 is in the closed state, the top sealing cover of the first balancing hole 11 is set on the sealing column 10; when the valve body 1 is in the open state, the first balancing hole 11 is separated from the sealing column 10;

[0040] In this solution, since the second valve core needs to move inside the first valve core, a sealing column and a first balancing hole are provided so that the circulating medium can enter the gap between the first and second valve cores, thereby facilitating the suction or discharge of the medium without affecting the relative movement between the first and second valve cores.

[0041] like Figure 2 As shown, in order to facilitate the movement of the first valve core in the flow sleeve, the present invention adopts a second balancing hole 12 opened on the side of the first valve core 5; a stroke cavity 13 for the first valve core 5 to move up and down is formed between the first valve core 5 and the flow sleeve 3; the second balancing hole 12 communicates with the inlet of the valve body 1 and the stroke cavity 13;

[0042] The principle of the second balancing hole is consistent with that of the first balancing hole, and facilitates the up and down movement of the first valve core in the stroke chamber.

[0043] like Figure 3 As shown, in order to illustrate the specific structure of the first valve core, the present invention adopts a first valve core 5 including: a first cylinder 14, a first annular groove 15 is provided on the side wall of which is sealed and connected to the fixed sleeve 3 and is installed with a metal sealing ring; a valve stem connecting hole 16 is opened at the top center of the first cylinder 14 and is threadedly connected to the end of the valve stem 7; a second cylinder 17, an outer diameter of which is larger than the outer diameter of the first cylinder 14, and is consistent with the inner diameter of the flow sleeve 3 and the outer diameter of the second cylinder 17; the outer diameter of the first cylinder 14 is equal to the inner diameter of the second cylinder 17.

[0044] A metal sealing ring is installed in the first annular groove and is sealed and slidably connected to the fixed sleeve. The outer diameter of the second cylinder is equal to the inner diameter of the flow sleeve, so that the flow rate can be adjusted. The outer diameter of the first cylinder is smaller than the outer diameter of the second cylinder and is equal to the inner diameter of the second cylinder. The purpose of this setting is to eliminate the area difference between the two, thereby eliminating the unbalanced force generated by the fluid on the outer cylindrical surface of the first valve core.

[0045] like Figure 3 、 4 As shown in the figure, how to realize the installation of the elastic member and the hanging connection of the first and second valve cores, the present invention adopts a method of annularly spaced mounting holes 18 and a balancing step hole 19 on the top of the first valve core 5; annularly spaced threaded blind holes 20 and an elastic member mounting hole 21 are formed on the top of the second valve core 6; a bolt 22 passes through the mounting hole 18 and is fixedly connected to the threaded blind hole 20; the elastic member 9 is located in the balancing step hole 19 and the elastic member mounting hole 21; when the valve body 1 is in the closed state, a gap is formed between the head of the bolt 22 and the bottom wall of the mounting hole 18;

[0046] The elastic part is installed in the step balancing hole and the elastic part mounting hole. The first and second valve cores are connected by bolts. When the valve body is in the open state, the head of the bolt is against the bottom of the mounting hole; when the valve body is in the closed state, there is a gap between the head of the bolt and the mounting hole.

[0047] like Figure 4 As shown, in order to illustrate the specific structure of the second valve core, the present invention adopts a second annular groove 23 on the outer wall of the second valve core 6 that is sealed to the side wall of the inner cavity 8 and is installed with a metal sealing ring.

[0048] A metal sealing ring is installed in the second annular groove to achieve a sealed connection between the first valve core and the second valve core.

[0049] like Figure 4 、 5 As shown, how to achieve a sealed connection between the second valve core and the valve seat, the present invention adopts a sealing inclined surface 24 opened on the bottom side wall of the second valve core 6, and the sealing inclined surface 24 is sealed against the first inclined surface 25 opened on the inner ring of the valve seat 4.

[0050] When the sealing inclined surface 24 at the bottom of the second valve core 6 abuts against the first inclined surface 25 of the valve seat 5 , the second valve core 6 abuts against the valve seat 4 to form a seal.

[0051] like Figure 1 As shown, in order to realize that the second valve core only performs a sealing function, the present invention adopts that when the valve body 1 is in the open state, the bottom plane of the second valve core 6 is not higher than the bottom plane of the first valve core 5;

[0052] The purpose of this design is that when the fluid passes through the window of the flow sleeve, the impact force of the medium acts entirely on the outer wall of the first valve core, and the second valve core is not impacted by the medium and only plays a role of sealing and cutting.

[0053] like Figure 5 As shown in the figure, in order to illustrate the specific structure of the valve seat, the present invention adopts a valve seat 4 with a first step surface 26 for fixing the bottom of the flow sleeve 3 and a second step surface 27 abutting against the bottom wall of the first valve core 5; an annular groove 28 is formed at the bottom of the valve seat 4, in which a sealing ring is installed to seal the valve seat 4;

[0054] The first step surface cooperates with the flow sleeve for positioning, the second step surface cooperates with the inner hole of the first valve core, and an annular groove is designed at the bottom of the valve seat for installing a sealing ring and contacting the valve body to play a sealing role.

[0055] When the valve is required to open, the first valve core moves upward under the drive of the valve stem, and the pressure in the upper chamber of the first valve core passes through the second balancing hole to balance the pressure in the upper and lower chambers of the first valve core. The actuator only needs a very small force to move the first valve core up and down, and the pressure in the upper chamber also acts on the upper surface of the second valve core through the balancing step hole so that the second valve core temporarily does not move with the first valve core. At this time, during the movement of the first valve core, the middle sealing column and the second balancing hole of the second valve core are disengaged, and the pressure is discharged through the second balancing hole of the second valve core until the pressure in the upper chamber of the first valve core and the pressure after the valve are completely balanced. When the first valve core continues to move upward, the end face of the bolt head contacts the mounting hole on the first valve core. At this time, the second valve core drives the first valve core to move upward together.

[0056] The present invention is a pilot-operated regulating valve, in which the first valve core is connected by a valve stem, driving the first valve core to move up and down in a flow sleeve, and the second valve core is slidably arranged in the first valve core, and the two are suspended and arranged, and an elastic member is arranged between the first valve core and the second valve core; when the device needs to be closed, the valve stem moves downward, so that the second valve core, the first valve core and the valve seat are abutted against each other to achieve sealing; when the device is opened, the valve stem moves upward, and the first valve core moves upward driven by the valve stem. At this time, under the action of the elastic member, the second valve core is still abutted against the valve seat, and when the first valve stem moves up a certain distance, the second valve core is disengaged from the valve seat; the movement of the first valve core in the flow sleeve changes the window area of ​​the flow sleeve to adjust the flow, and the impact force of the fluid acts on the outer wall of the first valve core. The first valve core is connected to the valve stem with a rigid thread, which has strong shock resistance and avoids high-frequency vibration of the first valve core.

[0057] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A pilot-operated regulating valve, characterized in that: include: The valve body is provided with a fixed sleeve, a flow sleeve and a valve seat in sequence from top to bottom; A first valve core, the top of which is fixedly connected to the valve stem and is slidably arranged in the flow sleeve under the control of the valve stem; a second valve core, which is slidably disposed in the inner cavity of the first valve core and suspended with the first valve core; an elastic member, disposed between the first valve core and the second valve core; When the valve body needs to be closed, the first valve core and the second valve core move downward under the drive of the valve stem, so that the bottoms of the second valve core and the first valve core are pressed against the valve seat for sealing; When the valve body needs to be opened, the first valve core and the second valve core move upward under the drive of the valve stem, and the first valve core and the second valve core are separated from the valve seat in turn, shortening the adjustment dead zone of the valve; When the valve body is in an open state, the bottom plane of the second valve core is not higher than the bottom plane of the first valve core; The top of the first valve core is provided with mounting holes and balancing step holes at intervals in an annular manner; The top of the second valve core is provided with threaded blind holes and elastic member mounting holes at intervals in an annular manner; The bolt passes through the mounting hole and is fixedly connected to the threaded blind hole; The elastic member is located in the balancing step hole and the elastic member mounting hole; When the valve body is in a closed state, a gap is formed between the bolt head and the bottom wall of the mounting hole.

2. A pilot-operated regulating valve according to claim 1, characterized in that: A sealing column is protruding from the bottom of the inner cavity of the first valve core; A first balancing hole is provided on the second valve core; When the valve body is in a closed state, the sealing cover on the top of the first balancing hole is arranged on the sealing cylinder; When the valve body is in an open state, the first balancing hole is separated from the sealing cylinder.

3. The pilot-operated regulating valve according to claim 1, characterized in that: A second balancing hole is provided on the side of the first valve core; A stroke cavity for the first valve core to move up and down is formed between the first valve core and the flow sleeve; The second balancing hole is connected to the valve body inlet and the stroke chamber.

4. The pilot-operated regulating valve according to claim 1, characterized in that: The first valve core includes: The first cylinder has a first annular groove on its side wall which is sealed to the fixed sleeve and is equipped with a metal sealing ring; a valve stem connection hole, which is provided at the center of the top of the first column and is threadedly connected to the end of the valve stem; The outer diameter of the second column is larger than that of the first column, and is consistent with the inner diameter of the flow sleeve and the outer diameter of the second column.

5. The pilot-operated regulating valve according to claim 4, characterized in that: The outer diameter of the first cylinder is equal to the inner diameter of the second cylinder.

6. The pilot-operated regulating valve according to claim 1, characterized in that: The outer wall of the second valve core is provided with a second annular groove which is sealed with the side wall of the inner cavity and is provided with a metal sealing ring.

7. The pilot-operated regulating valve according to claim 1, characterized in that: A sealing slope is provided on the side wall of the bottom of the second valve core, and the sealing slope is pressed against and sealed against the first slope provided on the inner ring of the valve seat.

8. The pilot-operated regulating valve according to claim 1, characterized in that: When the valve body is in an open state, a bottom plane of the second valve core is not higher than a bottom plane of the first valve core.

9. The pilot-operated regulating valve according to claim 1, characterized in that: The valve seat is provided with a first step surface for fixing the bottom of the flow sleeve and a second step surface abutting against the bottom wall of the first valve core; An annular groove is provided at the bottom of the valve seat, in which a sealing ring is installed and sealed to the valve seat.

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