Self-guiding flow reducing valve

Abstract

The self-guiding flow pressure reducing valve comprises a pressure reducing valve body, an inlet end is arranged on one side of the pressure reducing valve body, an outlet end is arranged on the other side of the pressure reducing valve body, and a valve body air inlet and a valve body air outlet are formed in the surface of the pressure reducing valve body; an upper valve cover is fixedly installed on the surface of a pressure reducing valve body, a filter screen assembly is fixedly installed on the side wall of one side of the upper valve cover, a main valve seat is fixedly installed in the pressure reducing valve body, a main valve clack is installed in the main valve seat, kidney-shaped holes are evenly formed in the side wall face of the main valve seat, an inner hexagonal hole is formed in the surface of the main valve seat, and one end of a main valve rod is installed in the inner hexagonal hole. The other end of the main valve rod is installed on the bottom face of the upper valve deck, and the main valve rod penetrates through the piston and the air cylinder and is installed on the pressure reducing valve body. A main valve clack inner cavity is formed in the main valve clack, a main valve spring is installed in the main valve clack inner cavity, and a lower valve cover is fixedly installed on the bottom face of the pressure reducing valve body. The self-guiding check valve has the advantages of being stable in structure, convenient to disassemble, capable of saving maintenance cost, capable of achieving self-guiding and capable of avoiding deviation and jamming of the valve clack.

Description

Technical Field

[0001] The invention relates to the technical field of pressure reducing valve equipment, and in particular to a self-guided flow pressure reducing valve. Background Art

[0002] The self-operated pressure reducing valve can be simply considered as an automatic regulating valve that reduces the pressure before the valve to the required pressure after the valve through the throttling of the opening and closing parts, and can use the energy of the medium itself to keep the outlet pressure basically unchanged when the inlet pressure and flow rate change. It is currently widely used in water supply systems, hydraulic systems and other occasions that require pressure reduction and stabilization.

[0003] At present, the main valve seat and main valve disc of self-operated pressure reducing valve in my country are mainly separated. Although this structure is simple in design and has low requirements for the matching relationship between the valve seat and valve disc, it also brings a series of problems, such as the valve disc lacks guidance or has poor guidance coaxiality, and the fit with the valve seat is poor, resulting in high pressure at the rear end; the sealing surface is mostly cone-to-cone, which has high requirements for the valve disc to sit, and it is very easy to cause medium leakage; the valve stem is embedded in the valve disc, and there are many assembly chains, which have high requirements for its coaxiality, and it is easy to cause jamming, etc. In order to solve such problems, this patent studies a self-guided main valve seat and valve disc component, that is, the main valve disc slides directly in the valve seat during operation without external guidance, ensuring that the valve disc is perfectly seated, which not only solves the guidance problem, but also avoids the medium leakage problem caused by the low fit of the valve disc and valve seat, greatly reducing energy waste. The waist-shaped holes are evenly distributed around the valve seat, which not only solves the flow capacity, but also can accurately control the flow volume, forming a combined functional relationship between the opening and the flow rate, so the development of the self-guided flow adjustable pressure reducing valve seat component is particularly important.

[0004] For the current pilot-operated pressure reducing valve, the pilot valve, as a pilot component, has strict processing accuracy, extremely small stroke, narrow flow channel, and is easily stuck by impurities in the medium or scratches the sealing surface. For this reason, a filter is often installed in front of the pressure reducing valve. Even so, it is still difficult to prevent tiny impurities from entering the pilot valve and affecting the working performance of the pressure reducing valve.

[0005] Traditional pilot valves are often split-type, mainly using the valve cover and pilot valve core to form the pilot component. Although this design has a simple structure, the parts are scattered, and the valve seat cannot be directly repaired after being damaged, and the replacement cost is high. Summary of the invention

[0006] The purpose of the present invention is to provide a self-guided flow pressure reducing valve with reasonable structural design, novel concept, convenient operation, stable structure and easy disassembly, which can save maintenance costs, solve the problem of pilot valve being stuck, realize self-guiding, and avoid valve disc deviation and sticking.

[0007] The invention discloses a self-guided flow pressure reducing valve, comprising a pressure reducing valve body, wherein an inlet end is arranged on one side of the pressure reducing valve body, an outlet end is arranged on the other side, and a valve body air inlet hole and a valve body air outlet hole are arranged on the surface of the pressure reducing valve body respectively; an upper valve cover is fixedly installed on the surface of the pressure reducing valve body, a filter screen assembly is fixedly installed on one side wall of the upper valve cover, a main valve seat is fixedly installed in the pressure reducing valve body, a main valve disc is installed in the main valve seat, waist-shaped holes are evenly opened on the side wall surface of the main valve seat, an inner hexagonal hole is arranged on the surface of the main valve seat, one end of a main valve stem is installed in the inner hexagonal hole, and the other end of the main valve stem is installed on the bottom surface of the upper valve cover, the main valve stem passes through a piston and a cylinder, and the piston and the cylinder are installed on the pressure reducing valve body; a main valve disc inner cavity is arranged in the main valve disc, a main valve spring is installed in the main valve disc inner cavity, a lower valve cover is fixedly installed on the bottom surface of the pressure reducing valve body, and the bottom end of the main valve spring is located on the surface of the lower valve cover; an adjusting sleeve is fixedly installed on the surface of the upper valve cover.

[0008] The main valve disc is embedded in the main valve seat valve, and the main valve disc is built into the main valve seat. It can switch in the main valve seat without the help of other guiding devices, realizing self-guiding and avoiding valve disc deviation and jamming; the waist-shaped holes are evenly distributed around the valve seat to realize a specific functional relationship between relative opening and relative flow. In the initial stage and the final stage, the flow change is unstable. At this time, the semicircular flow cross-section can make the flow and opening have equal percentage characteristics. When the flow is small, the flow change is small, and when the flow is large, the flow change is large. That is, at different openings, it has the same adjustment accuracy, ensuring the adjustment accuracy of the pressure reducing valve and the stability of the flow. In the middle stroke, the flow cross-section is set to a rectangle, showing a quick-opening flow characteristic. The flow is large at a small opening. As the stroke increases, the valve opening flow quickly reaches the maximum.

[0009] A pilot diaphragm is fixedly mounted on the surface of the upper valve cover, and a pilot valve assembly is mounted on the bottom surface of the pilot diaphragm through the upper valve cover thread.

[0010] The pilot valve assembly comprises a pilot valve seat, a pilot valve seat annular groove, a pilot valve seat conical sealing belt, a pilot valve seat air flow hole, a pilot spring, a pilot valve core, a pilot valve core labyrinth groove, a pilot valve core throat, a pilot valve core spherical sealing belt, and a pilot valve back cap. The pilot valve seat is located in the upper valve cover, a pilot valve seat annular groove is provided on the side wall of the pilot valve seat, and a pilot valve seat air flow hole is provided on the side wall of the pilot valve seat annular groove; a pilot spring is installed in the inner cavity of the pilot valve seat, the surface of the pilot spring contacts with the pilot valve back cap, the pilot valve back cap is located on the bottom surface of the pilot valve adjusting bolt, and the bottom surface of the pilot spring is located on the inner cavity surface of the pilot valve seat; a pilot valve core is installed in the pilot valve seat, a pilot valve core groove is provided on the surface of the pilot valve core, and a pilot valve core throat is provided on the pilot valve core.

[0011] The functions of the pilot valve assembly are: 1) the pilot valve senses the change in medium pressure to control the action of the main valve, thereby achieving stable control of the medium pressure; 2) the pilot pressure reducing valve is based on negative feedback control. When the medium pressure exceeds the set value, the pilot valve senses the change in medium pressure and controls the closing of the main valve to reduce the flow of the medium, thereby reducing the medium pressure; when the medium pressure is lower than the set value, the pilot valve senses the change in medium pressure and controls the opening of the main valve to increase the flow of the medium, thereby increasing the medium pressure. This principle of negative feedback control can keep the medium pressure close to the set value at all times, achieving stable control of the medium pressure.

[0012] The bottom surface of the pilot valve seat is provided with a pilot valve seat conical sealing belt; the bottom surface of the pilot valve core is provided with a pilot valve core spherical sealing belt.

[0013] The upper valve cover comprises an upper valve cover vertical air inlet, an upper valve cover horizontal air inlet, an upper valve cover rear end air flow feedback hole, an upper valve cover horizontal air outlet, an upper valve cover vertical air outlet, an upper valve cover rear side process hole, and an upper valve cover rear side air flow hole. The bottom surface of the upper valve cover is provided with an upper valve cover vertical air inlet, and the top end of the upper valve cover vertical air inlet is connected with the upper valve cover horizontal air inlet. The surface of the upper valve cover is provided with an upper valve cover rear end air flow feedback hole, and the bottom end of the upper valve cover rear end air flow feedback hole is connected with the upper valve cover horizontal air outlet, and the bottom surface of the upper valve cover horizontal air outlet is connected with the upper valve cover vertical air outlet, and the upper valve cover vertical air inlet is connected with the valve body air inlet through an elastic cylindrical pin, and the upper valve cover vertical air outlet is connected with the valve body air outlet through an elastic cylindrical pin.

[0014] The function of the upper valve cover is to better control the flow and pressure of the pressure reducing valve.

[0015] The filter assembly includes a filter plug, a perforated plate, a filter, and a rectangular cushion. The filter plug is connected to the upper valve cover. The inner wall of the filter plug is installed with a perforated plate. The surface of the perforated plate is provided with a filter. A rectangular cushion is provided between the filter assembly and the valve cover.

[0016] The filter assembly is in front of the pilot valve, at the flow channel inlet of the upper valve cover. The filter can be used to block fine impurities in the medium in front of the pilot valve, which not only protects the pilot valve and ensures the normal operation of the pressure reducing valve. Since the filter components are frequently maintained, the filter assembly is set on the valve cover for easy disassembly and maintenance.

[0017] Beneficial effects of the present invention: 1) The main valve disc is embedded in the main valve seat valve. The main valve disc is built into the main valve seat. It can switch in the main valve seat without the help of other guiding devices, realizing self-guiding and avoiding valve disc deviation and jamming; the waist-shaped holes are evenly distributed around the valve seat, which can play a role in regulating fluid flow and pressure. By changing the opening size of the waist-shaped holes, the cross-sectional area of ​​the fluid can be controlled, thereby regulating the fluid flow and pressure. When it is necessary to reduce the flow, the opening of the waist-shaped holes can be appropriately reduced; conversely, when it is necessary to increase the flow, the opening of the waist-shaped holes can be increased. The shape design of the waist-shaped holes makes it have certain linear characteristics when adjusting the flow and pressure, and can control more accurately. Fluid output; During the operation of the pressure reducing valve, a pressure difference will be generated when the fluid passes through the main valve seat. The waist-shaped holes arranged around the valve seat can help balance the pressure before and after the valve seat and reduce the impact of pressure fluctuations on valve performance. When the fluid flows from the high-pressure side to the low-pressure side, the waist-shaped holes can make part of the fluid flow from the high-pressure side to the surrounding area of ​​the low-pressure side, thereby balancing the pressure and improving the stability and reliability of the valve; The design of the waist-shaped holes can reduce the accumulation and blockage of impurities in the fluid at the valve seat. When the fluid passes through the waist-shaped holes, a certain flow rate and turbulence will be generated, which will help to flush away impurities and prevent them from accumulating on the valve seat, thereby ensuring the normal operation of the valve. ; Due to the presence of the waist-shaped hole, the pressure reducing valve can respond to system changes more quickly when adjusting flow and pressure. When the system pressure or flow changes, the waist-shaped hole can quickly adjust the fluid passage area, so that the valve can quickly reach a new equilibrium state, improving the system's response speed and control accuracy; There is a close relationship between the opening of the waist-shaped hole of the pressure reducing valve seat and the flow. Generally speaking, the larger the opening, the greater the flow; the smaller the opening, the smaller the flow. In the straight section of the waist-shaped hole, the opening and the flow are approximately linearly related. When the opening gradually increases, the flow will also increase linearly accordingly; conversely, when the opening gradually decreases, the flow will also decrease linearly; this linear relationship The relationship allows the operator to control the flow rate more accurately by simply adjusting the opening of the waist-shaped hole; in actual applications, due to the influence of factors such as the properties of the fluid, pressure difference, valve structure, etc., the relationship between the opening and the flow rate is not completely linear. At the two ends of the smaller and larger openings, the flow rate may change relatively slowly, showing an equal percentage characteristic. When the opening is very small, even if the opening is slightly reduced, the change in flow rate may not be obvious; and when the opening is close to the maximum, the effect of further increasing the opening on the flow rate will gradually weaken, that is, at different openings, it has the same adjustment accuracy, ensuring the adjustment accuracy of the pressure reducing valve and the stability of the flow rate.

[0018] 2) The functions of the pilot valve assembly are: a. The pilot valve controls the action of the main valve by sensing the change in medium pressure, thereby achieving stable control of the medium pressure; b. The pilot pressure reducing valve is based on negative feedback control. When the medium pressure exceeds the set value, the pilot valve senses the change in medium pressure and controls the closing of the main valve to reduce the flow of the medium, thereby reducing the medium pressure; when the medium pressure is lower than the set value, the pilot valve senses the change in medium pressure and controls the opening of the main valve to increase the flow of the medium, thereby increasing the medium pressure. This principle of negative feedback control can keep the medium pressure close to the set value at all times, achieving stable control of the medium pressure.

[0019] 3) The function of the upper valve cover is to better control the flow and pressure of the pressure reducing valve.

[0020] 4) The filter assembly is located in front of the pilot valve, at the flow channel inlet of the upper valve cover. The filter can be used to block fine impurities in the medium in front of the pilot valve, which not only protects the pilot valve and ensures the normal operation of the pressure reducing valve. Since the filter components are frequently repaired, the filter assembly is set on the valve cover for easy disassembly and maintenance.

[0021] 5) The device has a reasonable structural design, novel concept, convenient operation, stable structure and easy disassembly, which can save maintenance costs, ensure that the main valve seat and the main valve disc are perfectly seated, avoid leakage of the medium, and greatly reduce energy waste. At the same time, the opening and flow rate can be presented in a combined function relationship to ensure that the pressure reducing valve can accurately and stably control the flow rate. The valve disc and valve seat are compact and beautiful as a whole, with superior and stable performance; a filter assembly is set at the inlet flow channel of the upper valve cover to prevent impurities from entering and jamming the pilot valve, causing the pressure at the rear end of the pressure reducing valve to remain high, affecting the performance of the pressure reducing valve; the integral pilot valve design can ensure that the pilot valve core and the pilot valve seat are stable, have good sealing, and are easy to disassemble and assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a partial view of the upper valve cover in the present invention; Figure 3 It is a structural schematic diagram of the main valve seat in the present invention; Figure 4 This is a main cross-sectional view of the main valve seat in the present invention; Figure 5 A top view of the main valve seat in the present invention; Figure 6 This is a main cross-sectional view of the main valve disc in the present invention; Figure 7 It is a main cross-sectional view of the filter assembly in the present invention; Figure 8It is a main sectional view of the pilot valve assembly in the present invention.

[0023] In the figure: valve body 1, valve body air inlet 101, valve body air outlet 102, inlet end 103, outlet end 104, main valve spring 2, main valve disc 3, main valve disc spherical sealing belt 301, main valve disc inner cavity 302, main valve seat valve 4, waist hole 401, valve seat conical sealing belt 402, inner hexagonal hole 403, elastic cylindrical pin 5, filter screen assembly 6, filter screen plug 601, punching plate 602, filter screen 603, rectangular cushion 604, upper valve cover 7, upper valve cover vertical air inlet 701, upper valve cover horizontal air inlet 702, upper valve cover rear end air flow feedback hole 703, upper valve cover horizontal air outlet 704, upper valve cover vertical air outlet 705, upper valve cover rear Side process hole 706, air flow hole 707 on the rear side of the upper valve cover, adjusting sleeve 8, locking nut 9, adjusting bolt 10, adjusting spring 11, pilot diaphragm 12, pilot valve assembly 13, pilot valve seat 1301, pilot valve seat annular groove 13011, pilot valve seat conical sealing belt 13012, pilot valve seat air flow hole 13013, pilot spring 1302, pilot valve core 1303, pilot valve core labyrinth groove 13031, pilot valve core throat 13032, pilot valve core spherical sealing belt 13033, pilot valve back cap 1304, pilot valve adjusting bolt 1305, sealing gasket 14, piston 15, cylinder 16, main valve stem 17, lower valve cover 18. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] The present invention comprises a valve body 1, a valve body air inlet 101, a valve body air outlet 102, an inlet end 103, an outlet end 104, a main valve spring 2, a main valve disc 3, a main valve disc spherical sealing belt 301, a main valve disc inner cavity 302, a main valve seat valve 4, a waist-shaped hole 401, a valve seat conical sealing belt 402, an inner hexagonal hole 403, an elastic cylindrical pin 5, a filter screen assembly 6, a filter screen plug 601, a punching plate 602, a filter screen 603, a rectangular cushion 604, an upper valve cover 7, an upper valve cover vertical air inlet 701, an upper valve cover horizontal air inlet 702, an upper valve cover rear end air flow feedback hole 703, an upper valve cover horizontal Air outlet 704, upper valve cover vertical air outlet 705, upper valve cover rear side process hole 706, upper valve cover rear side air flow hole 707, adjusting sleeve 8, locking nut 9, adjusting bolt 10, adjusting spring 11, pilot diaphragm 12, pilot valve assembly 13, pilot valve seat 1301, pilot valve seat annular groove 13011, pilot valve seat conical sealing belt 13012, pilot valve seat air flow hole 13013, pilot spring 1302, pilot valve core 1303, pilot valve core labyrinth groove 13031, pilot valve core throat 13032, pilot valve core spherical sealing belt 13033, pilot valve back cap 1 304, pilot valve adjusting bolt 1305, sealing gasket 14, piston 15, cylinder 16, main valve stem 17, lower valve cover 18, the specific structure includes a pressure reducing valve body 1, one side of the pressure reducing valve body 1 is provided with an inlet end 103, the other side is provided with an outlet end 104, the surface of the pressure reducing valve body 1 is respectively provided with a valve body air inlet hole 101 and a valve body air outlet hole 102; the surface of the pressure reducing valve body 1 is fixedly installed with an upper valve cover 7, one side wall of the upper valve cover 7 is fixedly installed with a filter screen assembly 6, the pressure reducing valve body 1 is fixedly installed with a main valve seat 4, the main valve seat 4 is installed with a main valve disc 3, the side wall of the main valve seat 4 Waist-shaped holes 401 are evenly opened on the wall surface, and an inner hexagonal hole 403 is provided on the surface of the main valve seat 4. One end of the main valve stem 17 is installed in the inner hexagonal hole 403, and the other end of the main valve stem 17 is installed on the bottom surface of the upper valve cover 7. The main valve stem 17 passes through the piston 15 and the cylinder 16, and the piston 15 and the cylinder 16 are installed on the pressure reducing valve body 1; a main valve disc inner cavity 302 is provided in the main valve disc 3, and a main valve spring 2 is installed in the main valve disc inner cavity 302; a lower valve cover 18 is fixedly installed on the bottom surface of the pressure reducing valve body 1, and the bottom end of the main valve spring 2 is located on the surface of the lower valve cover 18; an adjusting sleeve 8 is fixedly installed on the surface of the upper valve cover 7.

[0026] A pilot diaphragm 12 is fixedly mounted on the surface of the upper valve cover 7, and a pilot valve assembly 13 is mounted on the bottom surface of the pilot diaphragm 12 through the upper valve cover thread.

[0027] The pilot valve assembly 13 includes a pilot valve seat 1301, a pilot valve seat annular groove 13011, a pilot valve seat conical sealing belt 13012, a pilot valve seat air flow hole 13013, a pilot spring 1302, a pilot valve core 1303, a pilot valve core labyrinth groove 13031, a pilot valve core throat 13032, a pilot valve core spherical sealing belt 13033, and a pilot valve back cap 1304. The pilot valve seat 1301 is located in the upper valve cover 7. The side wall of the pilot valve seat 1301 is provided with a pilot valve seat annular groove 13011. The pilot valve seat annular groove 13011 is provided with a pilot valve seat annular groove 13011. A pilot valve seat air flow hole 13013 is provided on the side wall; a pilot spring 1302 is installed in the inner cavity of the pilot valve seat 1301, the surface of the pilot spring 1302 is in contact with the pilot valve back cap 1304, the pilot valve back cap 1304 is located on the bottom surface of the pilot valve adjusting bolt 1305, and the bottom surface of the pilot spring 1302 is located on the inner cavity surface of the pilot valve seat 1301; a pilot valve core 1303 is installed in the pilot valve seat 1301, a pilot valve core groove 13031 is provided on the surface of the pilot valve core 1303, and a pilot valve core throat 13032 is provided on the pilot valve core 1303.

[0028] The bottom surface of the pilot valve seat 1301 is provided with a pilot valve seat conical sealing belt 13012 ; the bottom surface of the pilot valve core 1303 is provided with a pilot valve core spherical sealing belt 13033 .

[0029] The upper valve cover 7 comprises an upper valve cover vertical air inlet hole 701, an upper valve cover horizontal air inlet hole 702, an upper valve cover rear end air flow feedback hole 703, an upper valve cover horizontal air outlet hole 704, an upper valve cover vertical air outlet hole 705, an upper valve cover rear side process hole 706, and an upper valve cover rear side air flow hole 707. The bottom surface of the upper valve cover 7 is provided with an upper valve cover vertical air inlet hole 701, and the top end of the upper valve cover vertical air inlet hole 701 is connected to the upper valve cover horizontal air inlet hole 702. The surface of the upper valve cover 7 is provided with an air flow feedback hole 703 at the rear end of the upper valve cover, the bottom end of the air flow feedback hole 703 at the rear end of the upper valve cover is connected with the horizontal air outlet hole 704 of the upper valve cover, and the bottom surface of the horizontal air outlet hole 704 of the upper valve cover is connected with the vertical air outlet hole 705 of the upper valve cover; the vertical air inlet hole 701 of the upper valve cover is connected with the air inlet hole 101 of the valve body through the elastic cylindrical pin 5, and the vertical air outlet hole 705 of the upper valve cover is connected with the air outlet hole 102 of the valve body through the elastic cylindrical pin 5.

[0030] The filter assembly 6 includes a filter plug 601, a perforated plate 602, a filter 603, and a rectangular cushion 604. The filter plug 601 is connected to the upper valve cover 7. The inner wall of the filter plug 601 is installed with a perforated plate 602. The surface of the perforated plate 602 is provided with a filter 603. A rectangular cushion 604 is provided between the filter assembly 6 and the valve cover 7.

[0031] The filter screen 603 has 200 meshes; the number of the waist-shaped holes 401 is 8.

[0032] Instructions for use: The main valve seat 4 is connected to the valve body 1 partition by threads, and the connection is sealed with a copper gasket; the main valve spring 2 is connected to the lower valve cover 18 and the valve disc 3; the upper part of the main valve disc 3 is in direct contact with the main valve stem 17 to produce a mutual pushing effect; the filter screen and the punching plate are rolled into a cylindrical shape, and the filter screen plug 601 is inserted to form a filter screen assembly 6, and the filter screen assembly 6 is screwed into the upper valve cover 7 to filter the medium entering the valve body air inlet 101; the pilot valve seat 1301, the pilot spring 1302, the pilot valve core 1303, the pilot valve back cap 1304, and the pilot valve adjusting bolt 1305 are installed in turn to form a pilot valve assembly 13, which is installed in the upper valve cover 7 and sealed with a copper gasket.

[0033] The main valve seat 4 is installed in the valve body 1 of the pressure reducing valve by threading using the hexagonal inner 403 of the main valve seat. Figure 1 As shown: in the initial state, the main valve spring 2 is in the initial state, the main valve is closed, and the main valve disc 3 falls on the valve seat 4 to achieve line sealing; the adjusting bolt 10 is adjusted to compress the adjusting spring 11, causing the pilot diaphragm 12 to deform downward and then act on the pilot valve adjusting bolt 1305, the pilot valve core 1303 is separated from the pilot valve seat 1301, and the pilot valve is opened. As the pilot valve of the pressure reducing valve opens, the medium enters the upper cavity of the piston 15 through the valve body air inlet 101 - filter assembly 6 - upper valve cover vertical air inlet pipe 701 - upper valve cover horizontal air inlet 702 - pilot valve assembly 13 - upper valve cover rear side process hole 706 - upper valve cover rear side air flow hole 707, pushing the piston 15 to drive the main valve stem 17 to move downward, and then pushing the main valve disc 3 to compress the main valve spring 2 to move downward, the main valve opens, and the medium flows through the main valve. At this time, there is a stable secondary pressure at the corresponding rear end; at the same time, the rear end medium will give a reaction force to the pilot diaphragm 12 through the valve body air outlet 102 - upper valve cover vertical air outlet 705 - upper valve cover horizontal air outlet 704 - upper valve cover rear end air flow feedback hole 703, and the pilot diaphragm 12 is balanced at this time.

[0034] When the flow rate before the valve increases, the flow rate at the rear end will also increase. At this time, the secondary pressure at the rear end should increase, but the flow rate at the rear end is fed back to the bottom of the pilot diaphragm 12, compressing the pilot spring 11, causing the pilot valve opening to decrease, thereby reducing the main valve opening. At this time, the flow rate at the rear end will also decrease, thereby ensuring that the pressure at the rear end remains unchanged.

[0035] If the flow rate needs to be increased while the rear end pressure remains unchanged, the opening of the rear end regulating valve will be increased. In theory, the rear end pressure will drop, but the reaction force under the pilot diaphragm 12 will decrease, and the opening of the pilot valve will increase accordingly, thereby increasing the opening of the main valve and increasing the flow rate. A large flow rate can compensate for the rear end pressure and ensure that the rear end secondary pressure remains stable.

Claims

1. A self-guided flow pressure reducing valve, comprising a pressure reducing valve body (1), wherein one side of the pressure reducing valve body (1) is provided with an inlet end (103), and the other side of the pressure reducing valve body (1) is provided with an outlet end (104), characterized in that: The surface of the pressure reducing valve body (1) is respectively provided with a valve body air inlet hole (101) and a valve body air outlet hole (102); an upper valve cover (7) is fixedly installed on the surface of the pressure reducing valve body (1), a filter screen assembly (6) is fixedly installed on one side wall of the upper valve cover (7), a main valve seat (4) is fixedly installed in the pressure reducing valve body (1), a main valve disc (3) is installed in the main valve seat (4), waist-shaped holes (401) are evenly opened on the side wall surface of the main valve seat (4), an inner hexagonal hole (403) is provided on the surface of the main valve seat (4), and a main valve stem (102) is installed in the inner hexagonal hole (403). The main valve stem (17) is mounted on one end of the upper valve cover (7), and the other end of the main valve stem (17) is mounted on the bottom surface of the upper valve cover (7). The main valve stem (17) passes through the piston (15) and the cylinder (16). The piston (15) and the cylinder (16) are mounted on the valve body (1) of the pressure reducing valve. A main valve disc inner cavity (302) is provided in the main valve disc inner cavity (302). A main valve spring (2) is mounted in the main valve disc inner cavity (302). A lower valve cover (18) is fixedly mounted on the bottom surface of the valve body (1) of the pressure reducing valve. The bottom end of the main valve spring (2) is located on the surface of the lower valve cover (18). An adjusting sleeve (8) is fixedly mounted on the surface of the upper valve cover (7).

2. A self-piloted flow pressure reducing valve as claimed in claim 1, characterized in that: A pilot diaphragm (12) is fixedly mounted on the surface of the upper valve cover (7), and a pilot valve assembly (13) is mounted on the bottom surface of the pilot diaphragm (12) via the upper valve cover thread.

3. A self-piloted flow pressure reducing valve as claimed in claim 2, characterized in that: The pilot valve assembly (13) comprises a pilot valve seat (1301), a pilot valve seat annular groove (13011), a pilot valve seat conical sealing strip (13012), a pilot valve seat air flow hole (13013), a pilot spring (1302), a pilot valve core (1303), a pilot valve core labyrinth groove (13031), a pilot valve core throat (13032), a pilot valve core spherical sealing strip (13033), and a pilot valve back cap (1304). The pilot valve seat (1301) is located in the upper valve cover (7). The side wall of the pilot valve seat (1301) is provided with a pilot valve seat annular groove (13011). The pilot valve seat annular groove (13011) is provided with a pilot valve seat A pilot valve seat air flow hole (13013) is provided on the side wall; a pilot spring (1302) is installed in the inner cavity of the pilot valve seat (1301); the surface of the pilot spring (1302) contacts the pilot valve back cap (1304); the pilot valve back cap (1304) is located on the bottom surface of the pilot valve adjusting bolt (1305); the bottom surface of the pilot spring (1302) is located on the inner cavity surface of the pilot valve seat (1301); a pilot valve core (1303) is installed in the pilot valve seat (1301); a pilot valve core groove (13031) is provided on the surface of the pilot valve core (1303); and a pilot valve core throat (13032) is provided on the pilot valve core (1303).

4. A self-piloted flow pressure reducing valve as claimed in claim 3, characterized in that: The bottom surface of the pilot valve seat (1301) is provided with a pilot valve seat conical sealing belt (13012); the bottom surface of the pilot valve core (1303) is provided with a pilot valve core spherical sealing belt (13033).

5. A self-piloted flow pressure reducing valve as claimed in claim 4, characterized in that: The upper valve cover (7) comprises an upper valve cover vertical air inlet hole (701), an upper valve cover horizontal air inlet hole (702), an upper valve cover rear end air flow feedback hole (703), an upper valve cover horizontal air outlet hole (704), an upper valve cover vertical air outlet hole (705), an upper valve cover rear side process hole (706), and an upper valve cover rear side air flow hole (707). The upper valve cover vertical air inlet hole (701) is provided on the bottom surface of the upper valve cover (7), and the top end of the upper valve cover vertical air inlet pipe (701) is connected to the upper valve cover horizontal air inlet hole (702). The surface of the upper valve cover (7) is provided with an airflow feedback hole (703) at the rear end of the upper valve cover, the bottom end of the airflow feedback hole (703) at the rear end of the upper valve cover is connected to the horizontal air outlet hole (704) of the upper valve cover, the bottom surface of the horizontal air outlet hole (704) of the upper valve cover is connected to the vertical air outlet hole (705) of the upper valve cover, the vertical air inlet hole (701) of the upper valve cover is connected to the air inlet hole (101) of the valve body through an elastic cylindrical pin (5), and the vertical air outlet hole (705) of the upper valve cover is connected to the air outlet hole (102) of the valve body through an elastic cylindrical pin (5).

6. A self-piloted flow pressure reducing valve as claimed in claim 5, characterized in that: The filter screen assembly (6) comprises a filter screen plug (601), a perforated plate (602), a filter screen (603), and a rectangular soft pad (604); the filter screen plug (601) is connected to the upper valve cover (7); the inner side wall of the filter screen plug (601) is installed with a perforated plate (602); the surface of the perforated plate (602) is provided with a filter screen (603); and a rectangular soft pad (604) is provided between the filter screen assembly (6) and the valve cover (7).

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