A double-layer pneumatic pressure reducing valve

Abstract

The present invention discloses a pressure reducing valve, including a valve body, a valve plate assembly and a pressure regulating device; the valve body has a cavity inside and an inlet and an outlet are respectively arranged at the upper and lower ends of the cavity, the cavity is separated into an upper control cavity and a lower control cavity by a partition, and the inlet and the outlet are respectively connected with the upper control cavity and the lower control cavity; the valve plate assembly includes a hollow valve stem and a valve plate structure, the valve stem vertically passes through the upper control cavity and the lower end passes through the partition and is placed in the lower control cavity, the upper end of the valve stem is placed in the inlet, and the valve plate structure is placed in the upper control cavity; the lower control cavity is provided with a valve seat structure that cooperates with the movement of the lower end of the valve stem to adjust the fluid pressure flowing out of the lower end of the valve stem into the lower control cavity; the pressure regulating device is used to provide compressed fluid in the upper control cavity to drive the valve plate structure to drive the valve stem to move downward in the upper control cavity and to cooperate with the valve seat structure. The above-mentioned pressure reducing valve is simple and convenient to operate, saves cost and space, and can effectively improve the accuracy of pressure reducing control.

Description

Technical Field

[0001] The invention relates to a pressure reducing valve and relates to the technical field of pressure reducing valves. Background Art

[0002] The traditional pressure reducing valve mainly controls the pressure of the medium in the pressure reducing valve by the reaction force of the spring. The traditional pressure reducing valve has a slow reaction speed. The spring can only generate a reaction force after the force transmitted to the spring by the valve stem is deformed, and the pressure of the medium in the pressure reducing valve cannot be adjusted quickly. In addition, the traditional pressure reducing valve controls the opening of the valve core and the valve seat by storing and releasing the pressure of the medium in the pressure reducing valve on the valve core through the spring to achieve the effect of reducing the pressure of the medium in the pressure reducing valve. Due to the unstable performance of the spring, it is easy to cause large pressure fluctuations in the traditional pressure reducing valve, and then the pressure reduction effect cannot be accurately controlled. In addition, it relies on the wrist to rotate the handle on the pressure reducing valve to control the pressure reducing effect of the pressure reducing valve, which is time-consuming and laborious. Relying on manpower to control the pressure reducing effect of the pressure reducing valve cannot achieve accurate pressure reduction, which makes the pressure reduction process of adjusting the pressure reducing valve time-consuming and laborious. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a pressure reducing valve which is simple and convenient to operate, saves manpower and can effectively improve the accuracy of pressure reducing control.

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] A pressure reducing valve comprises a valve body, a valve plate assembly and a pressure regulating device;

[0006] The valve body has a cavity inside, and the upper and lower ends of the cavity are respectively provided with an inlet and an outlet, and the cavity is separated into an upper control cavity and a lower control cavity by a partition, and the inlet and the outlet are respectively connected to the upper control cavity and the lower control cavity;

[0007] The valve plate assembly includes a hollow valve stem and a valve plate structure. The valve stem vertically penetrates the upper control cavity and the lower end thereof passes through the partition plate and is placed in the lower control cavity. The upper end of the valve stem is placed in the inlet and is slidably connected to the inner wall of the inlet. The valve plate structure is placed in the upper control cavity and can drive the valve stem to move up and down in the upper control cavity.

[0008] The lower control chamber is provided with a valve seat structure that cooperates with the movement of the lower end of the valve stem to adjust the pressure of the fluid flowing out of the lower end of the valve stem into the lower control chamber through the pressure regulating device;

[0009] The pressure regulating device is used to provide compressed fluid in the upper control chamber to drive the valve plate structure in the upper control chamber to drive the valve stem to move downward and to interfere with the valve seat structure.

[0010] Preferably, the valve plate structure is connected to the valve stem and placed in the upper control chamber and divides the upper control chamber into two upper and lower valve chambers, the lower control chamber is connected to the valve chamber located below, and the valve chamber located above is connected to the pressure regulating device, and the valve stem moves up and down in the upper control chamber due to the pressure difference between the upper and lower valve chambers.

[0011] Preferably, the valve plate structure includes two valve plates, the upper control chamber is separated into two upper and lower opposite valve chambers by an upper partition, the two valve plates are respectively placed in the two valve chambers and the outer peripheral end surfaces of the valve plates are slidably connected to the inner walls of the valve chambers; the valve stem vertically passes through the upper partition and the centers of the two valve plates and is fixedly connected to the two valve plates; the pressure regulating device provides compressed fluid to the two valve chambers respectively to drive the two valve plates to move up and down in their respective valve chambers.

[0012] Preferably, sealing rings are embedded between the upper end of the valve stem and the inner wall of the inlet, between the valve stem and the partition through which it passes, between the center hole wall of the upper partition, and between the outer peripheral end surfaces of the two valve plates and the inner wall of the valve cavity.

[0013] Preferably, the two valve plates are an upper valve plate and a lower valve plate, a sleeve passing through the upper partition plate is provided between the upper valve plate and the lower valve plate, the sleeve ring is fixed on the outer wall of the valve stem, a plurality of drainage holes are provided on the wall of the sleeve, the drainage holes extend downward from the upper end surface of the sleeve along the axial direction of the valve stem to the lower surface of the lower valve plate, and an opening connecting to the lower cavity of the upper valve plate is provided on the outer side of the upper orifice of the drainage hole.

[0014] Preferably, the pressure regulating device includes an upper valve nozzle and a lower valve nozzle connected to a compressed fluid source, the upper valve nozzle includes a first upper valve nozzle and a second upper valve nozzle, a first flow channel and a second flow channel are opened on the upper wall of the valve body, one of the channel openings of the first flow channel and the second flow channel is respectively connected to the upper cavity of the two valve plates, and the first upper valve nozzle and the second upper valve nozzle are respectively connected to the other channel opening ends of the first flow channel and the second flow channel.

[0015] Preferably, a third flow channel is opened on the lower wall of the valve body, one channel opening of the third flow channel is connected to the lower cavity of the lower valve plate, and the lower valve nozzle is connected to the other channel opening end of the third flow channel.

[0016] Preferably, the valve seat structure includes a valve seat body, which is disc-shaped and fixed between the valve stem and the outlet of the valve body. The valve seat body divides the lower control chamber into two upper and lower cavities, and a plurality of openings connecting the upper and lower cavities are provided on the valve seat body.

[0017] Preferably, a conical protrusion is provided at the center of the valve seat body, with a pointed end facing upward and corresponding to the lower opening of the valve stem.

[0018] Preferably, a through hole communicating with the lower cavity of the valve seat is provided on the lower wall of the valve body, and the through hole is communicated with the first upper valve nozzle and the second upper valve nozzle respectively through pipelines.

[0019] Preferably, the valve body includes an upper shell, a middle shell and a lower shell that are fixed in sequence, and an upper partition is placed between the upper shell and the middle shell. The plate edge of the upper partition is fastened to the shell edges of the upper shell and the middle shell by bolts, and the partition is fixed in the middle shell.

[0020] Compared with the prior art, the present invention is beneficial in that:

[0021] First, by providing a valve plate structure and a hollow valve stem that is driven by the valve plate structure to move up and down in the upper control chamber of the valve body, the medium fluid passing through the pressure reducing valve can flow out from the inlet of the pressure reducing valve through the inside of the valve stem and through the outlet of the pressure reducing valve, and the compressed fluid provided by the pressure regulating device can drive the valve plate structure to drive the valve stem to move downward to cooperate with the valve seat structure to close the valve, thereby providing an opening pressure for the pressure reducing valve, and the pressure of the medium fluid flowing out of the lower end of the valve stem to the lower control chamber can be adjusted by the up and down telescopic movement of the valve stem combined with the valve seat structure at the lower end of the valve stem, thereby achieving the purpose of pressure reduction. Compared with the pressure reduction range that can be achieved by the limited telescopic amount of the spring structure in the traditional pressure reducing valve, the telescopic movement of the valve stem combined with the valve seat structure in the present invention makes its adjustable medium pressure range far exceed that of the traditional spring-type pressure reducing valve, and thus only one pressure reducing valve is needed to achieve the task of significantly reducing the pressure of the medium, saving cost and space;

[0022] Secondly, the expansion and contraction of the valve stem can be quickly adjusted by controlling the pressure regulating device to release or increase the fluid pressure in the cavity where the valve plate structure is located to the required pressure value. Combined with the valve seat structure, the pressure of the medium flowing out of the lower end of the valve stem to the lower control cavity can be adjusted to the required pressure value, thereby achieving the purpose of pressure reduction of the pressure reducing valve. The operation process is simple, time-saving and labor-saving, and the pressure reduction control is highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings:

[0024] Figure 1 is a bottom view of the present invention;

[0025] Figure 2 The present invention is Figure 1 The cross-sectional view in the AA direction;

[0026] Figure 3 The present invention is Figure 1 Cross-sectional view along the BB direction. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention:

[0028] like Figures 1 to 3 A pressure reducing valve shown in the figure comprises a valve body, a valve plate assembly and a pressure regulating device, wherein the valve body has a cavity inside and the upper and lower sides of the cavity are respectively provided with an inlet 1 and an outlet 2, the cavity is separated into an upper control cavity 4 and a lower control cavity 5 by a partition 3, and the inlet and the outlet are respectively connected to the upper control cavity and the lower control cavity; the valve plate assembly comprises a hollow valve stem 10 and a valve plate structure, the valve stem vertically passes through the upper control cavity and the lower end passes through the partition and is placed in the lower control cavity, the center of the valve stem is provided with an inner hole 101 that passes through the rod body along its axis, the upper end of the valve stem 10 is placed in the inlet 1 and is slidably connected to the inner wall of the inlet 1, and the valve plate structure is placed in the upper control cavity and can drive the valve stem to move up and down in the upper control cavity.

[0029] To facilitate the up and down movement of the valve stem, in this embodiment, the valve plate structure can be set to a piston-type single-layer valve plate or a multi-layer valve plate. When set to a single-layer valve plate, the single-layer valve plate is fixed on the valve stem and the edge of its plate body is sealed and slidably connected to the inner wall of the upper control chamber. The single-layer valve plate divides the upper control chamber into two independent upper and lower pressure chambers. Therefore, it is only necessary to provide compressed fluid to the two pressure chambers separately and control the different pressures of the fluids in the two pressure chambers to drive the single-layer valve plate to move up and down in the upper control chamber, thereby driving the valve stem to move up and down; and when set to a multi-layer valve plate, the upper control chamber can be divided into multiple independent piston chambers, and multiple valve plates are fixed on the valve stem and placed in independent piston chambers respectively. Therefore, compressed fluid can be provided to multiple piston chambers to drive multiple valve plates to perform piston-like motion together in their respective piston chambers, thereby driving the valve plates to move up and down together.

[0030] The lower control chamber is provided with a valve seat structure which cooperates with the movement of the lower end of the valve stem to adjust the fluid pressure flowing out of the lower end of the valve stem into the lower control chamber through a pressure regulating device; the pressure regulating device is used to provide compressed fluid to the upper control chamber to drive the valve plate structure to move downward in the upper control chamber and cooperate with the valve seat structure.

[0031] In one embodiment of the present invention, the pressure regulating device can be an air source, which is connected to the piston chamber through a solenoid valve, and controls the solenoid valve to inlet and exhaust air to different piston chambers to control the upward and downward movements of the valve plate. For example, the upper valve chamber is inlet, the lower valve chamber is exhausted, the valve stem moves downward, and its lower end is in conflict with the valve seat structure, the valve is closed, and when the inlet fluid pressure increases to the air source pressure value, the solenoid valve is controlled to act, so that the upper valve chamber is exhausted and the lower valve chamber is inlet, the valve plate structure drives the valve stem upward, the gap between the lower end of the valve stem and the valve seat structure becomes larger, the valve opens, the fluid flows out through the opening, and the inlet pressure decreases;

[0032] As another embodiment of the present invention, the valve plate structure is connected to the valve stem and is placed in the upper control chamber and divides the upper control chamber into two upper and lower valve chambers, the lower control chamber is connected to the valve chamber located below, and the valve chamber located above is connected to the pressure regulating device, and the valve stem moves up and down in the upper control chamber due to the pressure difference between the upper and lower valve chambers.

[0033] When the fluid enters the hollow part of the valve stem through the inlet and enters the lower control chamber, the pressure regulating device rushes the driving fluid into the upper valve chamber, the valve plate structure drives the valve stem to move downward to the lower dead point, the lower end of the valve stem and the valve seat structure cooperate, and the fluid inside the lower control chamber enters the valve chamber below. When the pressure of the inlet fluid is greater than the pressure applied by the pressure regulating device, the valve plate structure drives the valve stem to move upward. At this time, the lower end of the valve stem is separated from the valve seat structure, and the fluid inside the lower control chamber flows out through the opening, thereby achieving pressure reduction. In order to increase the speed of driving the valve stem movement and control the displacement accuracy of the valve stem, and to facilitate manufacturing and installation, the valve plate structure can be set to a double-layer valve plate structure, which includes two valve plates, namely an upper valve plate 11 and a lower valve plate 12, and two upper and lower opposite valve cavities 401 separated by an upper partition plate 6 are provided in the upper control cavity, the two valve plates are respectively placed in the two valve cavities and the outer peripheral end faces of the valve plates are slidably connected to the inner walls of the valve cavities; the valve stem vertically passes through the upper partition plate 6 and the centers of the two valve plates and is fixedly connected to the two valve plates; the pressure regulating device provides compressed fluid to the two valve cavities respectively to drive the two valve plates to move up and down in their respective valve cavities.

[0034] To facilitate installation and disassembly, the valve body includes an upper shell 7, a middle shell 8 and a lower shell 9 that are fixed in sequence, and an upper partition is placed between the upper shell and the middle shell. The plate edge of the upper partition is fastened to the shell edges of the upper shell and the middle shell by bolts, and the partition is fixed in the middle shell.

[0035] Therefore, in actual application, the medium enters the valve body from the inlet and enters the valve stem through the upper orifice at the upper end of the valve stem, then flows out through the lower orifice of the valve stem to the lower control chamber, and then flows out of the valve body from the outlet. When the medium flows out of the lower end of the valve stem, the pressure regulating device provides compressed fluid and drives the movement of the two valve plates and cooperates with the valve seat structure to adjust the fluid flow rate flowing out of the lower end of the valve stem to the lower control chamber, thereby meeting the pressure reduction requirements of the pressure reducing valve.

[0036] In this embodiment, since the medium flows vertically through the internal cavity of the valve stem to the lower end outlet of the pressure reducing valve, and the traditional pressure reducing valve adopts the traditional spring-type pressurized valve, the flow direction of the medium is mostly horizontal or nearly horizontal, so the wall thickness of the pressure reducing valve bears the pressure of the medium. For the safety of the pressure reducing valve, the wall thickness of the pressure reducing valve needs to be designed to be very thick. The medium flow method in this structure effectively reduces the pressure of the medium on the wall of the pressure reducing valve, so its wall thickness can be smaller than that of the traditional pressure reducing valve, which also reduces the overall weight and volume of the pressure reducing valve. In addition, due to the use of two layers of valve plates, the diameter of the valve plate can be reduced under the same piston area requirement, and then the volume of the overall pressure reducing valve can be reduced, thereby effectively reducing the installation space requirement of the piston and reducing the scale of the pressure reducing system.

[0037] In order to improve the sealing effect, maintain the airtightness between each cavity, and improve the control accuracy, sealing rings (a, b, c, d, e) are embedded between the upper end of the valve stem and the inner wall of the inlet, between the valve stem and the partition through which it passes, between the central hole wall of the upper partition, and between the outer peripheral end surfaces of the two valve plates and the inner wall of the valve cavity.

[0038] In this embodiment, in order to connect the lower cavities of the two valve plates and then provide the lower cavities of the two valve plates with compressed fluid of equal pressure at the same time, the two valve plates are respectively an upper valve plate 11 and a lower valve plate 12, and a sleeve 13 passing through the upper partition is provided between the upper valve plate and the lower valve plate, and the sleeve ring is fixed on the outer wall of the valve stem, and a plurality of drainage holes 14 are provided on the barrel wall of the sleeve, and the drainage holes extend from the upper end surface of the sleeve downward along the axial direction of the valve stem to the lower surface of the lower valve plate, and an opening 15 connecting to the lower cavity of the upper valve plate is provided on the outer side of the upper orifice of the drainage hole. In actual application, the sleeve, the lower valve plate and the valve stem are an integrated structure, which improves the stability of the structure and facilitates installation. By setting the drainage holes, it is convenient to connect the cavities on the lower side of the upper valve plate and the lower valve plate, so it is only necessary to provide compressed fluid to the lower cavity of any one of the valve plates, saving manufacturing cost and space.

[0039] In the present embodiment, the pressure regulating device includes an upper valve nozzle and a lower valve nozzle 16 connected to a compressed fluid source. In the present embodiment, the compressed fluid is compressed gas, and the medium is also gas. For example, the upper valve nozzle includes a first upper valve nozzle 17 and a second upper valve nozzle 18, wherein the valve nozzles are configured as gas valve nozzles, and a first flow channel 19 and a second flow channel 20 are provided on the upper wall of the valve body. One of the channel openings of the first flow channel and the second flow channel is connected to the upper side cavities of the two valve plates respectively. In the present embodiment, the second flow channel is arranged in the upper partition plate, and the first upper valve nozzle and the second upper valve nozzle are connected to the other channel opening ends of the first flow channel and the second flow channel respectively; therefore, the two gas valve nozzles can effectively provide compressed gas to the cavities on both sides of the two valve plates. Moreover, the flow channel is arranged on the wall of the valve body, thereby avoiding occupying other space resources. Furthermore, a third flow channel 21 is opened on the lower wall of the valve body, and one of the channel openings of the third flow channel is connected to the lower cavity of the lower valve plate, and the lower valve nozzle 16 is connected to the other channel opening end of the third flow channel. In actual application, compressed gas is input through the lower valve nozzle, the compressed gas enters the lower cavity of the lower valve plate, and then passes through the drainage hole and the opening, and enters the lower cavity of the upper valve plate, thereby realizing the process of providing equal pressure gas to the lower cavities of the two valve plates at the same time, and the third flow channel is arranged in the wall of the valve body to save space resources. In addition, to facilitate air intake and avoid the air port affecting the up and down movement of the upper and lower valve plates, one of the channel openings of the first flow channel is vertically facing the upper end surface of the upper valve plate, the second flow channel is arranged in the partition plate and its channel opening connected to the lower cavity of the lower valve plate is vertically facing the upper end surface of the lower valve plate, and one of the channel openings of the third flow channel is vertically facing the lower end surface of the lower valve plate.

[0040] In this embodiment, the valve seat structure includes a valve seat body 22, which is disc-shaped and fixed between the valve stem and the outlet of the valve body. The valve seat body divides the lower control chamber into two upper and lower cavities 501. A plurality of openings 23 connecting the upper and lower cavities are provided on the valve seat body. The plurality of openings are circumferentially arranged around the center of the valve seat body. Therefore, when the control valve stem moves up and down, the gap between the lower orifice at the lower end of the valve stem and the center of the valve seat body will increase or decrease, thereby limiting the flow rate of the medium flowing out of the lower orifice. Furthermore, a conical protrusion 24 is provided in the center of the valve seat body, and its pointed end is arranged upward and corresponds to the lower orifice of the valve stem. Therefore, when the valve stem moves up and down, it is more convenient to adjust the gap between the lower orifice of the valve stem and the conical protrusion, and the flow controllability is higher.

[0041] In the present embodiment, a through hole communicating with the lower cavity of the valve seat is provided on the lower wall of the lower part of the valve body, a bottom valve nozzle 25 is connected to the through hole and is communicated with the first upper valve nozzle and the second upper valve nozzle through a pipeline. Therefore, in actual operation, it is possible to avoid designing an additional compressed fluid source and directly introduce the medium flowing out of the lower end of the valve stem into the upper cavity of the upper valve plate and the lower valve plate, thereby keeping the pressure of the medium flowing out of the valve body the same as the fluid pressure in the upper cavity of the upper valve plate and the lower valve plate. Therefore, it is only necessary to pre-fill the lower valve nozzle with a fluid equal to the pressure of the medium after passing through the pressure reducing valve in the construction requirements, so as to meet the purpose of pressure reducing of the pressure reducing valve. In order to facilitate the checking of the pressure of the fluid flowing through the valve body, a pressure gauge for detecting the pressure of the medium in the lower control cavity may be provided at the lower part of the valve body.

[0042] In a traditional pressure reducing valve, the reaction force of the spring on the medium is used to control the distance between the valve core and the valve stem to reduce the pressure of the medium in the pressure reducing valve. The reaction force of the spring will weaken with the increase of service time, causing the performance of the pressure reducing valve to be unstable or deteriorate. In the structure of the invention, the pressure reducing effect is adjusted by the pressure difference between the fluids in the upper and lower cavities of the upper and lower valve plates, which is not affected by the service time and has more stable performance.

[0043] In this embodiment, taking the medium as gas and the compressed fluid as compressed gas as an example, if the medium flow pressure of the current medium gas flowing through the pressure reducing valve and flowing out to the lower control chamber is greater than the gas pressure in the lower side chambers of the upper valve plate and the lower valve plate, the airflow in the upper side chambers of the upper valve plate and the lower valve plate will drive the upper valve plate, the lower valve plate and the valve stem to move downward together, thereby reducing the gap between the lower end of the valve stem and the valve seat, and then reducing the flow rate of the medium flowing out to the lower valve body, thereby reducing the pressure of the medium flow flowing out to the lower control chamber, until the pressure of the medium flow flowing out to the lower control chamber is equal to the pressure in the lower side chambers of the upper valve plate and the lower valve plate, that is, the pressure in the upper side chambers of the upper valve plate and the lower valve plate is equal to the pressure in the lower side chambers. At this time, the upper valve plate, The lower valve plate will remain in a balanced and static state and will no longer move downward, thereby maintaining a stable outflow gap between the lower end of the valve stem and the valve seat. At this time, the pressure of the medium flowing into the lower control chamber and the outlet is equal to the pressure of the medium after passing through the pressure reducing valve in the construction requirements, meeting the pressure reduction requirements.

[0044] If the current medium gas flows through the pressure reducing valve and flows out into the lower valve body, the medium flow pressure is less than the air flow pressure in the lower cavity of the upper valve plate and the lower valve plate, the air flow in the lower cavity of the upper valve plate and the lower valve plate will drive the upper valve plate, the lower valve plate and the valve stem to move upward together, thereby increasing the gap between the lower end of the valve stem and the valve seat, and then increasing the flow rate of the medium flowing out into the lower control cavity, thereby increasing the pressure of the medium flow flowing out into the lower valve body, until the pressure of the medium flow flowing out into the lower control cavity is equal to the pressure in the lower cavity of the upper valve plate and the lower valve plate, that is, the pressure in the upper cavity of the upper valve plate and the lower valve plate is equal to the pressure in the lower cavity, at this time, the upper valve plate and the lower valve plate will maintain a balanced static state and no longer move upward, so that a stable outflow gap is maintained between the lower end of the valve stem and the valve seat, and at this time, the pressure of the medium flow flowing out into the lower control cavity and the outlet is equal to the pressure of the medium after passing through the pressure reducing valve in the construction requirements, meeting the pressure reduction requirements.

[0045] In practical applications, taking the medium as gas and the compressed fluid as compressed gas as an example, the specific pressure reducing process of the pressure reducing valve is explained. First, the pressure reducing valve is connected to the external pipeline, its inlet is connected to the inlet of the external pipeline, and the outlet is connected to the outlet of the external pipeline. First, according to the actual pressure reducing demand, an airflow with the same pressure as the medium after passing through the pressure reducing valve in the construction requirements is injected through the lower valve nozzle into the lower side cavity of the upper valve plate and the lower valve plate. At this time, the injected airflow will drive the valve stem and the upper valve plate and the lower valve plate to move upward together, so that a larger medium outflow gap is formed between the lower end of the valve stem and the valve seat, and then the control valve in the external pipeline is opened. , so that the medium passes through the inlet of the pressure reducing valve, the inner hole of the valve stem and the lower control cavity, and flows out to the lower cavity of the lower control cavity through the valve seat, and finally flows out to the external pipeline through the outlet at the bottom of the valve body. According to the pressure of the medium gas flow itself and the pressure of the medium after passing through the pressure reducing valve in the construction requirements, when the medium flows through the pressure reducing valve, dynamic pressure reduction is achieved according to the dynamic flow control process of the pressure reducing valve, and then the required pressure of the medium after flowing out of the pressure reducing valve is finally achieved. The control process is more precise, and when the pressure reduction value of the pressure reducing valve needs to be adjusted again, it is only necessary to adjust the pressure value of the gas pre-injected into the cavity on the lower side of the upper valve plate and the lower valve plate, and the gas can be flushed in or out through the lower valve nozzle. The pressure value is equal to the pressure of the medium after flowing out of the pressure reducing valve that needs to be adjusted, and the operation process is simple and fast.

[0046] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A pressure reducing valve, characterized in that: It includes a valve body, a valve plate assembly and a pressure regulating device; The valve body has a cavity inside, and the upper and lower ends of the cavity are respectively provided with an inlet and an outlet, and the cavity is separated into an upper control cavity and a lower control cavity by a partition, and the inlet and the outlet are respectively connected to the upper control cavity and the lower control cavity; The valve plate assembly includes a hollow valve stem and a valve plate structure. The valve stem vertically penetrates the upper control cavity and the lower end thereof passes through the partition plate and is placed in the lower control cavity. The upper end of the valve stem is placed in the inlet and is slidably connected to the inner wall of the inlet. The valve plate structure is placed in the upper control cavity and can drive the valve stem to move up and down in the upper control cavity. The lower control chamber is provided with a valve seat structure that cooperates with the movement of the lower end of the valve stem to adjust the pressure of the fluid flowing out of the lower end of the valve stem into the lower control chamber through the pressure regulating device; The pressure regulating device is used to provide compressed fluid in the upper control chamber to drive the valve plate structure in the upper control chamber to drive the valve stem to move downward and to interfere with the valve seat structure.

2. A pressure reducing valve according to claim 1, characterized in that: The valve plate structure is connected to the valve stem and is placed in the upper control chamber and divides the upper control chamber into two upper and lower valve chambers. The lower control chamber is connected to the valve chamber located below, and the valve chamber located above is connected to the pressure regulating device. The valve stem moves up and down in the upper control chamber due to the pressure difference between the upper and lower valve chambers.

3. A pressure reducing valve according to claim 2, characterized in that: The valve plate structure comprises two valve plates, the upper control chamber is separated into two valve chambers facing each other up and down by an upper partition, the two valve plates are respectively placed in the two valve chambers and the outer peripheral end surfaces of the valve plates are slidably connected to the inner walls of the valve chambers; the valve stem vertically passes through the upper partition and the centers of the two valve plates and is connected and fixed to the two valve plates; the pressure regulating device respectively provides compressed fluid to the two valve chambers to drive the two valve plates to move up and down in their respective valve chambers; Sealing rings are embedded between the upper end of the valve stem and the inner wall of the inlet, between the valve stem and the partition through which it passes, the central hole wall of the upper partition, and between the outer peripheral end surfaces of the two valve plates and the inner wall of the valve cavity.

4. A pressure reducing valve according to claim 3, characterized in that: The two valve plates are respectively an upper valve plate and a lower valve plate. A sleeve passing through the upper partition is provided between the upper valve plate and the lower valve plate. The sleeve ring is fixed on the outer wall of the valve stem. A plurality of drainage holes are provided on the wall of the sleeve. The drainage holes extend downward from the upper end surface of the sleeve along the axial direction of the valve stem to the lower surface of the lower valve plate. An opening is provided on the outer side of the upper orifice of the drainage hole to connect to the lower cavity of the upper valve plate.

5. A pressure reducing valve according to claim 3, characterized in that: The pressure regulating device includes an upper valve nozzle and a lower valve nozzle connected to a compressed fluid source, the upper valve nozzle includes a first upper valve nozzle and a second upper valve nozzle, a first flow channel and a second flow channel are opened on the upper wall of the valve body, one of the channel openings of the first flow channel and the second flow channel is respectively connected to the upper cavity of the two valve plates, and the first upper valve nozzle and the second upper valve nozzle are respectively connected to the other channel opening ends of the first flow channel and the second flow channel.

6. A pressure reducing valve according to claim 5, characterized in that: A third flow channel is opened on the lower wall of the valve body, one channel opening of the third flow channel is connected to the lower cavity of the lower valve plate, and the lower valve nozzle is connected to the other channel opening end of the third flow channel.

7. A pressure reducing valve according to claim 5, characterized in that: The valve seat structure includes a valve seat body, which is disc-shaped and fixed between the valve stem and the outlet of the valve body. The valve seat body divides the lower control cavity into two upper and lower cavities, and a plurality of openings connecting the upper and lower cavities are arranged on the valve seat body.

8. A pressure reducing valve according to claim 7, characterized in that: A conical protrusion is arranged at the center of the valve seat body, and the pointed end of the conical protrusion is arranged upward and corresponds to the lower opening of the valve stem.

9. A pressure reducing valve according to claim 7, characterized in that: A through hole communicating with the lower cavity of the valve seat is provided on the lower wall of the valve body, and the through hole is communicated with the first upper valve nozzle and the second upper valve nozzle through pipelines.

10. A pressure reducing valve according to claim 2, characterized in that: The valve body includes an upper shell, a middle shell and a lower shell that are fixed in sequence, an upper partition is placed between the upper shell and the middle shell, the plate edge of the upper partition is fastened to the shell edges of the upper shell and the middle shell by bolts, and the partition is fixed in the middle shell.

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