A pilot-operated pressure reducing valve for semiconductor wet process

Abstract

A pilot pressure reducing valve for semiconductor wet process is disclosed, comprising a main valve, a driving valve membrane for downward air pressure regulation, a non-connected suspended valve stem and an elastic element providing an upward fixed elastic force. A closed valve port and a gap ring located above the closed valve port are provided in the main valve. The driving valve membrane has a self-balancing valve head aligned and adapted to the gap ring. The valve stem has a pressure reducing valve head capable of closing the closed valve port, an upper guide column arranged on the pressure reducing valve head, a diaphragm arranged under the pressure reducing valve head and a lower guide column located below the diaphragm. When the pressure fluctuation from the fluid input is increasing, the self-balancing valve head automatically moves up slightly to reduce the opening of the pressure reducing valve head; when the pressure fluctuation from the fluid input is decreasing, the self-balancing valve head automatically moves down slightly to expand the opening of the pressure reducing valve head. The example of the present invention has the effect that the fluid pressure of the output flow channel is relatively stable within a specific pressure reducing range, so as to provide a stable fluid output pressure.

Description

[0001] This invention is a divisional application, and the basis of the divisional application is the invention application with application number 202311583546.X, application date November 24, 2023, and invention name "Adjustable pressure-stabilizing valve and assembly method thereof, semiconductor manufacturing equipment". Technical Field

[0002] The invention relates to the technical field of key components in manufacturing equipment for electrical component assemblies, and in particular to a pilot pressure reducing valve used in semiconductor wet process. Background Art

[0003] One of the main uses of diaphragm valves is to open and close the medium fluid transmission, but there are also diaphragm valves for other purposes, such as pressure reducing valves, which are used to reduce the pressure of the output fluid. However, the pressure fluctuation of the input fluid of the pressure reducing valve often affects the pressure of the output fluid, and the fluctuation of the fluid pressure value is sometimes not accepted by the semiconductor manufacturing process or precision manufacturing. In the semiconductor manufacturing process, there are more stringent requirements for the pressure stability of the working fluid, the precision adjustment of the flow rate and the corrosion resistance of the valve body. If the fluid pressure introduced into the equipment is sensitive to the fluctuation of the input fluid pressure, the fluid input supply and fluid speed will fluctuate, which will be detrimental to the quality control of the precise production of semiconductor manufacturing.

[0004] There are many structures and corresponding systems of current pressure reducing valves. Invention publication number CN1806216A discloses a relative pressure control system and a relative flow control system. The relative pressure control system can correctly adjust the partial pressure ratio of the working gas with a simple pressure reducing valve structure, and can surely extract the working gas from the working gas supply pipeline in an emergency. The system has a plurality of normally open pneumatic valves connected to the working gas supply pipeline to which the working gas is supplied, pressure sensors connected in series with the pneumatic valves to detect the pressure output by the pneumatic valves, a controller to control the operating pressure of the pneumatic valves according to the pressure detected by the pressure sensors, and a hard interlocking electromagnetic valve to associate at least one of the plurality of pneumatic valves with the valves open at all times, adjust the opening of a given pneumatic valve from the plurality of pneumatic valves, and output the working gas according to the specified partial pressure ratio. It can also be seen from this that the pressure reducing valve system under the relevant patent technology concept needs to monitor the gas pressure of multiple pneumatic valves in real time, that is, the valve opening of the pressure reducing valve is controlled by external driving air pressure or mechanical means, and requires corresponding external driving components, and the pressure reducing effect has a lag (it is necessary to first determine the degree of fluid pressure abnormality before determining the adjustment range of the pressure reducing valve), which is the inherent technical thinking in this field.

[0005] In addition, someone proposed a more specific structure of a pressure reducing valve in the utility model patent number CN201934677U, which has the following mechanical structures, including valve body, valve cover, diaphragm, adjusting screw, adjusting spring, spring pressure block, spring pad, compression sleeve, valve disc assembly, return spring, screw plug, the valve disc assembly is mainly composed of valve disc, push rod and seal arranged on the valve disc, the valve disc is provided with a stepped mounting hole, one end of the mounting hole is used to install the push rod, and the other end is used to install the return spring, the bottom of the push rod is provided with an axial blind hole, and a number of radial return holes are evenly arranged on the inner wall of the bottom of the blind hole. The diaphragm is a modified rubber diaphragm, which has the effect of reducing the impact when the valve is opened, so that the pressure in the valve is more stable. Pressure gauge interfaces are provided on both sides of the valve body. Gaskets are respectively provided on the push rod and the valve disc. When the pressure reducing valve is closed, if the medium at the outlet flows back, it will flow into the bottom of the valve disc through the through hole on the push rod. The valve disc assembly will accelerate the return under the action of the liquid pressure and can better seal the pressure reducing valve. Among them, the adjusting screw of the related prior art is obviously an external drive component. Rotating the adjusting screw can change the opening height of the valve disc component and thus adjust the medium flow to reach the required pressure value, that is, the valve opening of the pressure reducing valve cannot be changed without rotating the adjusting screw. This once again confirms that "external drive" is an inherent thinking in the field of pressure reducing valve technology.

[0006] In addition, the invention patent publication number CN104728488A proposes a pipeline pressure-stabilizing valve, which is mainly composed of a valve body, a valve disc, a valve cover, a spring, an adjusting screw, a diaphragm, a valve stem and a valve seat. A diaphragm is installed between the valve body and the valve cover, and a valve cavity is formed between the valve cover and the diaphragm. A spring is installed in the valve cavity, a spring plug is installed on the upper part of the spring, and a spring seat is installed on the lower part of the spring. One end of the adjusting screw extends into the valve cavity and contacts the spring plug. The adjusting screw is threaded with the valve cover, and the spring seat contacts the diaphragm. The valve disc is arranged in the valve body, and a valve seat is also arranged in the valve body. The valve seat can contact and seal with the lower end of the valve disc. The valve disc is limited by the valve stem, and the valve stem is arranged vertically. A positioning ring is fixed on the valve stem, and the valve disc is passed through the valve stem above the positioning ring, and the lower end of the valve disc contacts the positioning ring. The simple structure under the existing related technology proposes the concept of pressure stabilization effect, which seems to be directly installed on the pipeline to stabilize the outlet pressure and achieve the effects of pressure reduction, equal pressure and pressure stabilization. However, there is a lack of specific description of the pressure stabilization mechanism. The adjusting screw uses a spring to adjust the valve opening. From the structural diagram, it can be seen that relevant technical personnel can reasonably infer that when the input fluid pressure fluctuates instantly, the spring contracts elastically due to the fluid thrust, and the valve opening actually changes to a larger value. As the input fluid pressure increases and the valve opening increases, the output fluid pressure through the pipeline pressure-stabilizing valve also increases significantly at the moment of input pressure fluctuation. Therefore, the current pressure stabilization mechanism cannot meet actual industry needs. Summary of the invention

[0007] At present, there is a lack of research on the adverse effects of instantaneous fluctuations in the pressure of external input fluid on the output of the pressure reducing valve. Therefore, the main purpose of the present invention is to provide a pilot pressure reducing valve for semiconductor wet process, which mainly solves the problem that the pressure of the liquid supply fluid is easily affected by the pressure of the external input fluid due to the excessive decreasing / increasing fluctuation rate of the traditional pressure reducing valve. In addition, it also solves the process defects of the traditional pressure reducing valve that will cause the precipitation of particles and ions. The present invention proposes the concept of dynamic self-adjusting balance of the pressure reducing valve, that is, the pressure reducing valve can synchronously adjust its own dynamic balance at the moment of fluctuation of the external input fluid pressure.

[0008] The second main purpose of the present invention is to provide a semiconductor manufacturing equipment that can significantly reduce the impact of external input fluid pressure fluctuations on the stable supply of valve output fluid pressure to the liquid unit in the equipment.

[0009] The third main purpose of the present invention is to provide an assembly method of a pilot-operated pressure reducing valve, which realizes the non-connected internal installation of a non-connected suspended valve stem.

[0010] The main purpose of the present invention is achieved through the following technical solutions:

[0011] A pilot-operated pressure reducing valve is provided, comprising:

[0012] A main body valve is provided with an input flow channel, an output flow channel, a closed valve port connecting the input flow channel and the output flow channel, and a notch ring located above the closed valve port, and an elastic element is provided at the bottom of the main body valve;

[0013] A driving valve membrane for air pressure regulation is arranged on the top of the main valve to separate a top air pressure cavity and a flow channel space from top to bottom, and the driving valve membrane has a self-balancing valve head aligned and adapted to the notch ring;

[0014] A non-connected suspended valve stem, comprising a pressure reducing valve head capable of closing the sealed valve port, an upper guide column arranged on the pressure reducing valve head, a diaphragm arranged under the pressure reducing valve head, and a lower guide column located below the diaphragm, wherein the upper guide column only contacts the self-balancing valve head of the driving valve membrane to accept the downward-pushing gas pressure of the driving valve membrane, and the lower guide column accepts the upward-pushing elastic force of the elastic element; when the pressure fluctuation of the fluid from the input flow channel is increasing and partially acts on the self-balancing valve head, the self-balancing valve head automatically moves up slightly to reduce the opening of the pressure reducing valve head; when the pressure fluctuation of the fluid from the input flow channel is decreasing and partially acts on the self-balancing valve head, the self-balancing valve head automatically moves down slightly to expand the opening of the pressure reducing valve head; the top end of the upper guide column is tightly fitted in the axial hole of the self-balancing valve head; when the elastic element lifts the non-connected suspended valve stem to the highest point, the pressure reducing valve head closes the sealed valve port, and the self-balancing valve head is not enough to break away from the gap ring.

[0015] The implementation principle of this basic structural example is to utilize the longitudinal combination of the non-connected suspended valve stem, the driving valve membrane for constructing an adjustable downward air pressure, and the elastic element that provides an upward fixed elastic force, the self-balancing valve head of the driving valve membrane is aligned with the notch ring adapted to the main valve, the pressure-reducing valve head of the non-connected suspended valve stem is suspended in the flow channel space, and the opening of the pressure-reducing valve head in the closed valve port can be dynamically and mechanically self-adjusted to produce a stable pressure-reducing effect. That is, when the pressure fluctuation of the fluid from the input flow channel is increasing and partially acts on the self-balancing valve head, the self-balancing valve head automatically moves up slightly to reduce the opening of the pressure reducing valve head, in response to the increasing pressure of the input fluid, and a stable output fluid pressure with increasing input pressure is generated under mutual compensation; when the pressure fluctuation of the fluid from the input flow channel is decreasing and partially acts on the self-balancing valve head, the self-balancing valve head automatically moves down slightly to expand the opening of the pressure reducing valve head, in response to the decreasing pressure of the input fluid, and a stable output fluid pressure with decreasing input pressure is generated under mutual compensation. , no matter the positive pressure fluctuation or negative pressure fluctuation at the input end, the pilot pressure reducing valve can stabilize the output fluid pressure in a mechanical automatic self-dynamic adjustment manner, so as to achieve the effect of low fluctuation of output fluid pressure and fast self-adjustment, and has the protection function of constant fluid pressure, and does not require real-time monitoring or electromagnetic or power-consuming adjustment of the opening, or can reduce the energy consumption required for real-time monitoring frequency and valve opening adjustment; within the ten-fold pressure reduction range, the fluid pressure of the output flow channel is stabilized within the increasing fluctuation rate of 0% to 10% or the decreasing fluctuation rate is stabilized within the decreasing fluctuation rate of -10% to 0%. Utilizing the combination relationship between the upper guide column and the self-balancing valve head and the shape design of the non-connected suspended valve stem, the condition for the pressure reducing valve head to close the closed valve port is defined as the upper dead point when the non-connected suspended valve stem rises to the highest point, and the self-balancing valve head still cannot be separated from the gap ring, so the gap ring of the main valve can play a sufficient guiding and anti-slipping role for the self-balancing valve head of the driving valve membrane.

[0016] In a preferred example, the present invention can be further configured such that the diameter of the self-balancing valve head is larger than the diameter of the pressure reducing valve head, so that within the eight-fold pressure reduction range, the fluid pressure of the output flow channel is specifically stabilized at an increasing fluctuation rate within 0% to 5% or a decreasing fluctuation rate within -5% to 0%.

[0017] By adopting the preferred technical features of the above-mentioned structure and utilizing the diameter difference between the self-balancing valve head and the pressure reducing valve head, the self-balancing valve head can sense the fluid pressure fluctuation from the input flow channel and perform self-regulation. In addition, the pressure reducing valve head is linked to the self-balancing valve head. Within the eight-fold pressure reduction range, the fluid pressure in the output flow channel has a more stable increasing and decreasing fluctuation rate.

[0018] In a preferred example, the present invention can be further configured as follows: the pilot-operated pressure reducing valve further includes: a floating adjustment seat, which is arranged on the elastic element and elastically contacts with the lower guide column, and is used to transmit the rising elastic force of the elastic element to the non-connected suspended valve stem; a guide hole is formed on the upper surface of the floating adjustment seat to elastically contact the bottom end of the lower guide column; the guide hole has an inner R angle, and the bottom end of the lower guide column has an outer R angle, and the inner R angle is greater than the outer R angle, so as to facilitate axial alignment of the lower guide column and facilitate the floating adjustment seat to be detached from the lower guide column.

[0019] By adopting the preferred technical features of the above structure, and utilizing the structure and connection relationship of the floating adjustment seat, the floating adjustment seat can well withstand the upward elastic force of the elastic element, and act as a medium to apply force to the non-connected suspended valve stem, so that the pressure reducing valve head moves in the direction of reducing the opening, thereby increasing the pressure reducing amplitude. Preferably, by utilizing the difference between the inner R angle of the guide hole of the floating adjustment seat and the outer R angle at the bottom end of the lower guide column of the non-connected suspended valve stem, the non-connected suspended valve stem is deformed by external force, and the axial direction of the lower guide column is preferentially changed, and a large stress is not directly generated on the connection between the upper guide column and the self-balancing valve head. After the sudden external force is eliminated or reduced, based on the difference between the inner and outer R angles, the lower guide column is guided by the floating adjustment seat, which can gradually reset the lower guide column back to the axial direction. Therefore, the connection between the upper guide column of the non-connected suspended valve stem and the self-balancing valve head does not require a fixed mechanical connection, and is not easy to tilt or fall off.

[0020] In a preferred example, the present invention may be further configured as follows: the pressure reducing valve head has an inverted cone slope to reduce the lateral flow impact of the input fluid on the non-connected suspended valve stem.

[0021] By adopting the preferred technical features of the above-mentioned structure and utilizing the inverted cone slope of the pressure reducing valve head, the shaking of the lower guide column can be reduced under the fluctuation of the input fluid pressure, while avoiding the direct upward and downward force exerted on the pressure reducing valve head by the fluctuation of the input fluid pressure. This shape can slow down the force exerted on the pressure reducing valve head by the fluctuation of the input fluid pressure, but can sensitively adjust the opening of the pressure reducing valve head due to the fluctuation of the output fluid pressure.

[0022] In a preferred example, the present invention can be further configured as follows: an adjusting ball end extends from the bottom of the floating adjustment seat and is nested in the elastic element.

[0023] By adopting the preferred technical features of the above structure, the adjusting ball end of the floating adjusting seat is used to enable the floating adjusting seat to slide axially in the bottom elastic chamber of the main valve with a margin, so as to realize the axial alignment of the lower guide column. The adjusting ball end and the outer R angle of the bottom end of the lower guide column form a double reciprocating bendable and resettable structure to absorb the pressure fluctuation of the input flow channel, so as to avoid directly acting on the junction between the top end of the upper guide column and the self-balancing valve head, and to avoid the occurrence of the non-connected suspended valve stem being unable to automatically reset after bending.

[0024] In a preferred example, the present invention may be further configured such that the opening of the notch ring faces the inlet of the input flow channel, and a flow channel annular groove that can communicate with the output flow channel is formed on the periphery of the notch ring.

[0025] By adopting the preferred technical features of the above structure and utilizing the opening direction of the notch ring and the design of the flow channel ring groove, the flow channel space is made clean and free of dead zones.

[0026] In a preferred example, the present invention can be further configured as follows: an increase in the air pressure in the top air pressure chamber or / and a decrease in the fluid pressure in the output flow channel can move the self-balancing valve head downward, and when the non-connected suspended valve stem sinks to the lowest point, the shape and thickness of the self-balancing valve head cannot close the notch ring; the elastic force of the elastic element pushes up or / and an increase in the fluid pressure in the input flow channel can raise the non-connected suspended valve stem, and when the non-connected suspended valve stem rises to the highest point, the shape of the pressure reducing valve head can close the closed valve port.

[0027] By adopting the preferred technical features of the above structure, the shape structure and mutual relationship of the self-balancing valve head can sense the air pressure of the top air pressure chamber or the change of the fluid pressure of the output flow channel, and define the descending stop point of the self-balancing valve head so that the self-balancing valve head cannot close the gap ring, and define the ascending stop point of the self-balancing valve head so that the shape of the pressure reducing valve head can close the closed valve port. Therefore, when the air in the top air pressure chamber is extracted, the valve of the pilot pressure reducing valve can be closed naturally.

[0028] In a preferred example, the present invention can be further configured as follows: the outer ring edge of the self-balancing valve head is connected to a stop ring, which is larger than the outer diameter of the notch ring. When the stop ring abuts against the upper edge of the notch ring, the non-connected suspended valve stem sinks to the lowest point; the stop ring also extends above the flow channel ring groove, so that the fluid pressure from the output flow channel reduces the fluctuation energy acting on the drive valve membrane, and the self-balancing valve head automatically moves downward slightly.

[0029] By adopting the preferred technical features of the above-mentioned structure, utilizing the stop ring structure and mutual relationship of the self-balancing valve head, a mechanism for determining the descent stop point of the self-balancing valve head is established, and the fluid pressure fluctuation in the output channel will also change the position of the self-balancing valve head, thereby generating a self-balancing effect and stabilizing the fluid pressure fluctuation in the output channel.

[0030] The present invention can be further configured in a preferred example as follows: the main valve comprises:

[0031] The middle valve seat provides the input flow channel, the output flow channel, the closed valve port and the gap ring;

[0032] A lower valve seat is combined with the lower part of the middle valve seat and fixes the first peripheral ring portion of the diaphragm to form a bottom elastic chamber for accommodating the elastic element. A vent hole is opened on one side of the lower valve seat and connected to the bottom elastic chamber where the elastic element is located;

[0033] The upper valve cover is combined above the middle valve seat and fixes the second peripheral ring portion of the driving valve membrane to form a top air pressure chamber.

[0034] By adopting the preferred technical features of the above-mentioned structure and utilizing the combination relationship of the middle valve seat, the lower valve seat and the upper valve cover, the main valve can compositely fix the first peripheral ring portion of the diaphragm and the second peripheral ring portion of the driving valve membrane, effectively separating the top air pressure chamber, the bottom elastic chamber and the flow channel space therebetween.

[0035] In a preferred example, the present invention can be further configured as follows: an upper fixed ring groove is opened above the middle valve seat for the peripheral frame of the driving valve membrane to be engaged, and a lower fixed ring groove is opened below the middle valve seat for the peripheral frame of the diaphragm to be engaged, the driving valve membrane closes the upper opening of the middle valve seat, and the diaphragm closes the lower opening of the middle valve seat to form a flow channel space.

[0036] By adopting the preferred technical features of the above structure, the upper fixing ring groove and the lower fixing ring groove are utilized to increase the fixing force between the peripheral frame of the driving valve membrane and the peripheral frame of the diaphragm.

[0037] In a preferred example, the present invention can be further configured as follows: the peripheral frame of the driving valve membrane has a lower protruding edge corresponding to the upper fixed ring groove, and the peripheral frame of the diaphragm has an upper protruding edge corresponding to the lower fixed ring groove.

[0038] By adopting the preferred technical features of the above structure and utilizing the lower protruding edge and the upper protruding edge, leakage of the flow channel space to the top air pressure chamber and leakage to the bottom elastic chamber are reduced.

[0039] In a preferred example, the present invention can be further configured as follows: a sleeve is provided at the center of the lower valve seat for guiding the adjusting ball end of the floating adjusting seat, and the elastic element is sleeved on the outer diameter of the sleeve.

[0040] By adopting the preferred technical features of the above structure and utilizing the center sleeve of the lower valve seat, the elastic element can provide an upward elastic force that is not deflected in the longitudinal direction, so as to drive the floating adjustment seat to be guided toward the axis even if it is deflected, and to limit the guide sliding points of the adjusting ball end of the floating adjustment seat to be located at the axis center position.

[0041] The second main purpose of the present invention is achieved through the following technical scheme: a semiconductor manufacturing equipment is proposed, including a pilot-operated pressure-reducing valve that can implement any combination of features as described above, wherein the working fluid output by the pilot-operated pressure-reducing valve and introduced into the equipment machine is continuously at a stable fluid output pressure and will not be adversely affected by fluctuations in external fluid input pressure, which is conducive to stabilizing the production parameters of semiconductor manufacturing and maintaining better quality control.

[0042] The third main purpose of the present invention is achieved by the following technical solution: a method for assembling a pilot-operated pressure reducing valve with any combination of the above-mentioned features is proposed, comprising:

[0043] S1, installing the driving valve membrane at the middle top of the main valve;

[0044] S2, installing a non-connected suspended valve stem in the main valve, wherein the diaphragm of the non-connected suspended valve stem is limited to the bottom of the main valve to form a flow channel space;

[0045] S3, setting an elastic element at the bottom of the main valve;

[0046] S4, forming a bottom elastic chamber of the main valve outside the flow channel space, so that the lower guide column not connected to the suspended valve stem can receive the upward push elastic force of the elastic element;

[0047] S5. Form a top air pressure chamber of the main valve outside the flow channel space so that the upper guide column of the non-connected suspended valve stem can receive the downward pushing gas pressure of the driving valve membrane; wherein, during the process from step S1 to step S5, the self-balancing valve head of the driving valve membrane always slides on the notch ring of the main valve.

[0048] The implementation principle of this basic method example is to manufacture a pilot-operated pressure reducing valve driven by a mechanical structure without external force by utilizing steps S1 to S5, thereby achieving the protective effect of stable supply of fluid output pressure and not being sensitively affected by fluctuations in fluid input pressure.

[0049] In a preferred example, the present invention can be further configured as follows: the main valve in steps S1 to S3 specifically includes a middle valve seat, the main valve in step S4 also includes a lower valve seat combined with the bottom of the middle valve seat, and the main valve in step S5 also includes an upper valve cover combined with the top of the middle valve seat, a vent hole is provided on one side of the lower valve seat, which is connected to the bottom elastic chamber where the elastic element is located, and the assembly method also includes: connecting an exhaust pipe to the vent hole.

[0050] By adopting the preferred technical features of the above method, the lower valve seat and the upper valve cover are respectively combined with the bottom and the top of the middle valve seat in sequence, so as to construct a bottom elastic chamber with a fixed elastic force at the bottom of the middle valve seat and a top air pressure chamber with an adjustable air pressure at the top of the middle valve seat. During the assembly process from step S2 to step S3, since the top air pressure chamber has not yet been constructed, the non-connected suspended valve stem can always maintain the form of the pressure reducing valve head closing the closed valve port, and the non-connected suspended valve stem is relatively stable and does not shake during the assembly process, reducing the possible defects of fluid leakage caused by improper assembly operation.

[0051] In summary, the technical solution of the structure or method of the present invention includes at least one of the following technical effects that contribute to the prior art:

[0052] Provided is a pilot-operated pressure reducing valve that does not require continuous consumption of external energy (including electrical energy and pneumatic cylinder energy), which can reduce the adverse effects of fluid input pressure fluctuations and stabilize the fluid output pressure after pressure reduction; within a ten-fold pressure reduction range, the fluid pressure of the output flow channel is stabilized within an increasing fluctuation rate of 0% to 10% or a decreasing fluctuation rate of -10% to 0%; more specifically, by utilizing a ratio of a diameter of a self-balancing valve head being larger than a diameter of a pressure reducing valve head, the fluid pressure of the output flow channel is specifically stabilized within an increasing fluctuation rate of 0% to 5% or a decreasing fluctuation rate of -5% to 0% within an eight-fold pressure reduction range;

[0053] The pilot-operated pressure reducing valve does not need to be combined with the driving components (including pneumatic cylinder, driving screw, handwheel) of the main valve body, does not need to be constantly monitored and calibrated, and has the effect of stabilizing the fluid output pressure in a self-dynamically balanced manner;

[0054] The closed valve port in the flow channel space forms a blade seal structure, combined with the axial deviation correction connection relationship of the elastic element in the bottom elastic chamber, to achieve a zero leakage effect when the valve is closed;

[0055] The non-connected suspended valve stem forms a semicircular shape at the end of the lower guide column, which is designed with a large and small R angle with the floating adjustment seat. The end of the lower guide column can be offset and then corrected after being affected by the fluctuation of the fluid input pressure, so as to reduce the direct impact of the fluctuation impact of the fluid input pressure on the valve opening;

[0056] The peripheral frame of the driving valve membrane forms three sealing structures between the middle valve seat and the upper valve cover to prevent fluid leakage;

[0057] The vent hole of the lower valve seat not only balances the internal and external air pressure of the bottom elastic chamber, but also serves as a medium drainage port when the diaphragm not connected to the suspended valve stem ruptures;

[0058] The opening of the notch ring of the middle valve seat and the peripheral flow channel ring groove, and the assembly matching shape of the self-balancing valve head not connected to the suspended valve stem can meet the fluid design of the diaphragm of the driving valve membrane to reduce turbulence; and the internal flow channel space has the effect of no dead zone in the flow;

[0059] The non-connected suspended valve stem innovatively has two separate sealing structures to prevent the flow channel space from corroding and leaking into the top air pressure chamber and the bottom elastic chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A three-dimensional assembly diagram of a pilot-operated pressure reducing valve in some preferred embodiments of the present invention is shown;

[0061] Figure 2 An exploded view of a pilot-operated pressure reducing valve in some preferred embodiments of the present invention is shown;

[0062] Figure 3 A cross-sectional view of a pilot-operated pressure reducing valve cut along the XZ plane in some preferred embodiments of the present invention is shown;

[0063] Figure 4 A cross-sectional view of a pilot-operated pressure reducing valve cut along the YZ plane in some preferred embodiments of the present invention is shown;

[0064] Figure 5 Drawings are cross-sectional views of pilot-operated pressure reducing valves cut along the XY plane in some preferred embodiments of the present invention;

[0065] Figure 6 A three-dimensional view showing a non-connected suspended valve stem of a pilot-operated pressure reducing valve in some preferred embodiments of the present invention (A is a top view, and B is a bottom view);

[0066] Figure 7 The three-dimensional diagrams of the floating adjustment seat of the pilot-operated pressure reducing valve in some preferred embodiments of the present invention are shown (A is a top view, B is a bottom view);

[0067] Figure 8 The three-dimensional diagrams of the driving valve membrane of the pilot-operated pressure reducing valve in some preferred embodiments of the present invention are shown (A is a top view, and B is a bottom view);

[0068] Fig. 9 The three-dimensional diagrams of the middle valve seat of the main valve of the pilot-operated pressure reducing valve in some preferred embodiments of the present invention are shown (A is a three-dimensional diagram from the top, and B is a three-dimensional diagram from the bottom);

[0069] Fig.10 A three-dimensional view of the lower valve seat of the main valve of the pilot-operated pressure reducing valve in some preferred embodiments of the present invention is shown (A is a top view, and B is a bottom view);

[0070] Fig.11 The upper valve cover of the main valve of the pilot-operated pressure reducing valve in some preferred embodiments of the present invention is shown in three-dimensional view (A is a top view, and B is a bottom view);

[0071] Fig.12 The test data of a pilot-operated pressure reducing valve in some preferred embodiments of the present invention are shown;

[0072] Fig.13 A schematic diagram of the steps of an assembly method of a pilot-operated pressure reducing valve in some preferred embodiments of the present invention is shown.

[0073] Reference numerals:

[0074] 10. Main valve; 11. Input flow channel; 12. Output flow channel; 13. Sealed valve port; 14. Gap ring;

[0075] 15. Runner ring groove;

[0076] 20. driving valve membrane; 21. self-balancing valve head; 22. stop ring; 23. second peripheral ring portion;

[0077] 30. Non-connected suspended valve stem; 31. Pressure reducing valve head; 32. Upper guide post; 33. Diaphragm; 34. Lower guide post;

[0078] 35. a first peripheral ring portion; 40. an elastic element;

[0079] 50. Floating adjustment seat; 51. Guide hole; 52. Adjusting ball end;

[0080] 60, middle valve seat; 61, flow channel space; 62, upper fixed ring groove; 63, lower fixed ring groove;

[0081] 70, lower valve seat; 71, bottom elastic chamber; 72, vent hole; 73, sleeve;

[0082] 80. Upper valve cover; 81. Top air pressure chamber; 82. Pressurization hole;

[0083] 91. Connecting rod; 92. Connecting seat; 93. Dust cover. DETAILED DESCRIPTION

[0084] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments for understanding the inventive concept of the present invention, and cannot represent all the embodiments, nor are they interpreted as the only embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field on the premise of understanding the inventive concept of the present invention are within the scope of protection of the present invention.

[0085] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement of the components in a certain posture. If the specific posture changes, the directional indications will also change accordingly. In order to facilitate the understanding of the technical solution of the present invention, the pilot-operated pressure reducing valve of the present invention is further described and explained below, but it is not limited to the protection scope of the present invention.

[0086] See also Figures 1 to 5 Some embodiments of the present invention first provide a pilot-operated pressure reducing valve. Figure 1 Draw a three-dimensional assembly diagram of a pilot-operated pressure reducing valve. Figure 2 Draw an exploded view of the pilot operated pressure reducing valve. Figure 3 This is a cross-sectional view of the pilot-operated pressure reducing valve cut along the XZ plane, where the XZ plane is the longitudinal section along the flow channel. Figure 4 This is a cross-sectional view of the pilot-operated pressure reducing valve cut along the YZ plane, where the YZ plane is the longitudinal section across the flow channel. Figure 5 It is a cross-sectional view of the pilot-operated pressure reducing valve cut on the XY plane, wherein the XY plane is a horizontal section that crosses the flow channel. The embodiment of the present invention proposes a pilot-operated pressure reducing valve, which mainly includes: a main valve 10, a driving valve membrane 20 that provides adjustable air pressure at the top, a non-connected suspended valve stem 30 for implementing the pressure reducing opening, and an elastic element 40 that provides a fixed elastic force to the non-connected suspended valve stem 30 at the bottom. A top air pressure chamber 81 is constructed above the driving valve membrane 20, a flow channel space 61 is constructed between the driving valve membrane 20 and the diaphragm 33 of the non-connected suspended valve stem 30, and a bottom elastic chamber 71 is constructed below the diaphragm 33 of the non-connected suspended valve stem 30. The driving valve membrane 20 has a self-balancing valve head 21, and the non-connected suspended valve stem 30 has a pressure reducing valve head 31, and the two are in a longitudinal linkage relationship. The main valve 10 is provided with a sealed valve port 13 corresponding to the pressure reducing valve head 31 in the flow channel space 61 , and a notch ring 14 corresponding to the self-balancing valve head 21 is formed above the sealed valve port 13 .

[0087] The "drive" of the "drive valve membrane" refers to the valve membrane that does not directly adjust the opening of the normal valve membrane, that is, the drive component, not the actuator. The normal valve membrane uses its own valve head to reduce or expand the valve opening when driven, while the drive valve membrane 20 drives other valve heads (specifically, the pressure reducing valve head 31 that is not connected to the suspended valve stem 30) to reduce or expand the valve opening. The driving force of the drive valve membrane 20 mainly comes from the fluid input pressure, the air pressure formed by the compressed air in the top air pressure chamber 81, and the elastic force of the elastic element 40. If necessary, the fluid output pressure can also be introduced. Corresponding to the opening of the valve, the air pressure in the top air pressure chamber 81 is the positive force, and the fluid input pressure, fluid output pressure and the elastic force of the elastic element 40 are the reverse force. As one of the more specific structures of the pressure reducing valve, the pilot pressure reducing valve should always have a fluid input pressure greater than the fluid output pressure.

[0088] Regarding the "non-connected" in the "non-connected suspended valve stem", it refers to that the connection relationship between the non-connected suspended valve stem 30 and the driving valve membrane 20 excludes the generally known connection relationships, such as welding, screw connection, and C-clip connection, and also means that the non-connected suspended valve stem 30 will not penetrate the self-balancing valve head 21 of the driving valve membrane 20 and connect with other components.

[0089] The "self-balancing" of the "self-balancing valve head" refers to the ability of the self-balancing valve head 21 to achieve self-balancing pressure of the pilot-operated pressure reducing valve. The self-balancing valve head 21 changes its spatial position in the gap ring 14 in the fluid space, and balances the upper and lower pressures. This is because when the fluid input pressure is too small, the self-balancing valve head 21 will sink, the valve opening will become larger, and more input fluid will enter the gap ring 14, preventing the self-balancing valve head 21 from continuing to sink, and compensating the fluid output pressure at a stable value; when the fluid input pressure is too large, the input fluid enters the gap ring 14 faster, pushing the self-balancing valve head 21 up, the valve opening will become smaller, reducing the amount of input fluid entering the gap ring 14, and the self-balancing valve head 21 will rise to a balance point, stabilizing the fluid output pressure that may have fluctuated. That is to say, the fluctuation of the fluid input pressure will only affect the relative height position of the self-balancing valve head 21 in the notch ring 14, and the self-balancing valve head 21 will drive the valve opening of the pressure reducing valve head 31 in a linked manner, and the fluctuation of the fluid input pressure will not have a significant impact on the fluid output pressure. In addition, the "floating" of the "floating adjustment seat" refers to the floating movement of the floating adjustment seat 50 in the bottom elastic chamber 71 under the action of the elastic element 40.

[0090] The "decompression range" refers to the ratio of the input fluid pressure to the output fluid pressure. For example, the ten-fold decompression range refers to the input fluid pressure being between one (excluding the endpoint value) and ten (including the endpoint value) times the output fluid pressure; the eight-fold decompression range refers to the input fluid pressure being between one (excluding the endpoint value) and eight (including the endpoint value) times the output fluid pressure.

[0091] Regarding the "incremental volatility", its calculation formula is that after the pressure reducing valve is adjusted, the low setting value of the input fluid pressure has been set, and the low initial adjustment value of the output fluid pressure is also obtained by adjusting the air pressure of the top air pressure chamber 81. The difference of the actual change of the input fluid pressure is a positive number. The calculation of the incremental volatility is: the actual change value of the input fluid pressure minus the low setting value of the input fluid pressure is used as the positive number denominator, and the actual measured value of the output fluid pressure minus the low initial adjustment value of the output fluid pressure is used as the numerator. The percentage value obtained after multiplication and division is the incremental volatility. Fig.12 The actual inlet pressure, the actual outlet pressure under increasing inlet pressure and the increasing fluctuation rate of the second digital column, the actual change value of the input fluid pressure is 3, minus the low setting value of the input fluid pressure 2, and the denominator is 1; the actual measured value of the output fluid pressure is 1.02, minus the low initial adjustment value of the output fluid pressure 1, and the numerator is 0.02; 0.02 divided by 1 gives an increasing fluctuation rate of 2%. Fig.12 The actual inlet pressure, the actual outlet pressure under increasing inlet pressure and the increasing fluctuation rate in the seventh digital column, the actual change in the input fluid pressure is 8, minus the low setting value of the input fluid pressure 2, and the denominator is 6; the actual measured value of the output fluid pressure is 1.15, minus the low initial adjustment value of the output fluid pressure 1, and the numerator is 0.15; 0.15 divided by 6 gives an increasing fluctuation rate of 2.5%. When the increasing fluctuation rate is smaller, it means that when the input fluid pressure changes to a larger value, the output fluid pressure is less affected by its fluctuation.

[0092] Regarding the "decreasing volatility", the calculation formula is that after the pressure reducing valve is adjusted, the input fluid pressure high setting value has been set, and the output fluid pressure high initial adjustment value has also been obtained. The difference in the actual change of the input fluid pressure is a negative number. The calculation of the decreasing volatility is: the actual change value of the input fluid pressure minus the input fluid pressure high setting value is used as the negative denominator, and its absolute positive value is taken. The actual measured value of the output fluid pressure minus the output fluid pressure high initial adjustment value is used as the numerator. After multiplication and division, the percentage value is obtained, which is the decreasing volatility. Fig.12The actual inlet pressure, the actual outlet pressure under decreasing inlet pressure and the decreasing fluctuation rate of the sixth digital column, the actual positive change of the input fluid pressure is 7, minus the input fluid pressure high setting value 8 and take the absolute positive value, and get a denominator of 1; the actual measured value of the output fluid pressure is 0.98, minus the high initial adjustment value of the output fluid pressure 1, and get a numerator of -0.02; -0.02 divided by 1 gives a decreasing fluctuation rate of -2%. Another example Fig.12 The actual inlet pressure, the actual outlet pressure under decreasing inlet pressure and the decreasing fluctuation rate of the first digital column, the actual positive change of the input fluid pressure is 2, minus the input fluid pressure high setting value 8 and take the absolute value, to get a denominator of 6; the actual measured value of the output fluid pressure is 0.8, minus the high initial adjustment value of the output fluid pressure 1, to get a numerator of -0.2; -0.2 divided by 6 is -3.3% of the decreasing fluctuation rate. The smaller the decreasing fluctuation rate, the less the output fluid pressure is affected by its fluctuation when the input fluid pressure changes. In addition, Fig.12 It shows that compared with the absolute value of the decreasing volatility, the increasing volatility is relatively smaller, which means that when the input fluid pressure changes greatly, the output fluid pressure is less affected by its fluctuation than when the input fluid pressure changes slightly. Therefore, the low setting is slightly better than the high setting, and the difference between the two is not large. Fig.12 It also proves that the pilot pressure reducing valve of the present invention has the function of stabilizing pressure under pressure reduction adjustment, and can make both low-position setting and high-position setting. During measurement, after the low-position setting or high-position setting, the air pressure value in the top air pressure chamber 81 is no longer adjusted, and the consumption of external energy is minimal. Since the air pressure value in the top air pressure chamber 81 can be adjusted as necessary according to the actual installation occasion, but does not need to be adjusted from time to time, the pilot pressure reducing valve of the present invention also has the effect of pressure reduction, stabilization and recalibration.

[0093] See also Figures 1 to 5 The present invention illustrates a key component of a pilot-operated pressure reducing valve as follows. With particular reference to Figure 2 and Figure 3 First, regarding the main valve 10, an input flow channel 11, an output flow channel 12, a closed valve port 13 connecting the input flow channel 11 and the output flow channel 12, and a gap ring 14 located above the closed valve port 13 are provided therein. An elastic element 40 is provided at the bottom of the main valve 10 to provide a fixed elastic force to the non-connected suspended valve stem 30. Figure 8 Regarding the air pressure regulating driving valve membrane 20, the driving valve membrane 20 is arranged on the top of the main valve 10, and the top air pressure chamber 81 and the flow channel space 61 are separated from each other. The self-balancing valve head 21 of the driving valve membrane 20 is aligned with the gap ring 14 of the main valve 10, and the self-balancing valve head 21 can slide relatively in the gap ring 14 to a limited extent. Figure 6 , regarding the non-connected suspended valve stem 30, the non-connected suspended valve stem 30 has a pressure reducing valve head 31 capable of closing the closed valve port 13, an upper guide column 32 arranged on the pressure reducing valve head 31, a diaphragm 33 arranged under the pressure reducing valve head 31, and a lower guide column 34 located below the diaphragm 33, wherein the upper guide column 32 only contacts the self-balancing valve head 21 of the driving valve membrane 20 to receive the downward-pushing gas pressure of the driving valve membrane 20, and the lower guide column 34 receives the upward-pushing elastic force of the elastic element 40, so that the pressure reducing valve head 31 and the self-balancing valve head 21 form a longitudinal linkage relationship; when the fluid pressure fluctuation from the input flow channel 11 is increasing and partially acts on the self-balancing valve head 21, the self-balancing valve head 21 automatically moves up slightly to reduce the opening of the pressure reducing valve head 31, that is, the opening gap between the pressure reducing valve head 31 and the closed valve port 13 through which the fluid can pass becomes smaller. When the fluid pressure fluctuation from the input flow channel 11 is decreasing and partially acts on the self-balancing valve head 21, the self-balancing valve head 21 automatically moves down slightly to expand the opening of the pressure reducing valve head 31, that is, the opening gap between the pressure reducing valve head 31 and the closed valve port 13 through which the fluid can pass becomes larger; within the ten-fold pressure reduction range, the fluid pressure of the output flow channel 12 is stabilized within an increasing fluctuation rate of 0% to 10% or a decreasing fluctuation rate of -10% to 0%. The relevant test data is Fig.12 It can be verified.

[0094] The creative implementation method of this basic structure example is to utilize the longitudinal combination of the non-connected suspended valve stem 30, the driving valve membrane 20 for constructing an adjustable downward air pressure, and the elastic element 40 for providing an upward fixed elastic force, the self-balancing valve head 21 of the driving valve membrane 20 is aligned with the notch ring 14 adapted to the main valve 10, the pressure reducing valve head 31 of the non-connected suspended valve stem 30 is suspended in the flow channel space 61, and the opening of the pressure reducing valve head 31 in the closed valve port 13 can be dynamically and mechanically self-adjusted to produce a stable pressure reducing effect. That is, when the fluid pressure fluctuation from the input flow channel 11 is increasing and partially acts on the self-balancing valve head 21, the self-balancing valve head 21 automatically moves up slightly to reduce the opening of the pressure reducing valve head 31, so as to respond to the increasing input fluid pressure, and generate a stable output fluid pressure with increasing input pressure under mutual compensation; when the fluid pressure fluctuation from the input flow channel 11 is decreasing and partially acts on the self-balancing valve head 21, the self-balancing valve head 21 automatically moves down slightly to expand the opening of the pressure reducing valve head 31, so as to respond to the decreasing input fluid pressure, and generate a stable output fluid pressure with decreasing input pressure under mutual compensation. Regardless of whether it is a positive pressure fluctuation or a negative pressure fluctuation at the input end, the pilot pressure reducing valve can stabilize the output fluid pressure in a mechanical automatic self-dynamic adjustment manner, so as to achieve the effect of low fluctuation and fast self-adjustment of the output fluid pressure, and has the protection function of constant fluid pressure, does not require real-time monitoring, does not require electromagnetic or power-consuming adjustment of the opening, or can reduce the real-time monitoring frequency and the energy consumption required for valve opening adjustment. From another perspective, see Figure 3 When the pilot-operated pressure reducing valve is subjected to the fluctuation of the fluid input pressure of the input flow channel 11, if the fluid input pressure increases suddenly and sharply, causing the self-balancing valve head 21 to rise, the pressure reducing valve head 31 of the non-connected suspended valve stem 30 will naturally, synchronously and unpredictably rise instantaneously, the valve opening will decrease, the coordinated fluid flow rate will increase, and the fluid output pressure of the output flow channel 12 will be relatively stable; if the fluid input pressure decreases suddenly and sharply, causing the self-balancing valve head 21 to drop, the pressure reducing valve head 31 of the non-connected suspended valve stem 30 will naturally, synchronously and unpredictably drop instantaneously, the valve opening will expand, the coordinated fluid flow rate will decrease, and the fluid output pressure of the output flow channel 12 will be relatively stable.

[0095] In a preferred example of a dual valve head embodiment, see Figure 3 and Figure 4 The diameter of the self-balancing valve head 21 is larger than the diameter of the pressure reducing valve head 31, so that within the eight-fold pressure reduction range, the fluid pressure of the output flow channel 12 is specifically stabilized within an increasing fluctuation rate of 0% to 5% or a decreasing fluctuation rate of -5% to 0%. Fig.12The test data set shown in the figure shows that the actual inlet pressure is 2 to 8, 3 to 8, and 4-8 bar, and the absolute positive value of the increasing volatility and the decreasing volatility does not exceed 5% regardless of whether the actual inlet pressure is set at a high or low position. By utilizing the diameter difference between the self-balancing valve head 21 and the pressure reducing valve head 31, the self-balancing valve head 21 can sense the fluid pressure fluctuation from the input flow channel 11 for self-adjustment. In addition, the pressure reducing valve head 31 is linked to the self-balancing valve head 21. Within the eight-fold pressure reduction range, the fluid pressure of the output flow channel 12 has a more stable increasing volatility and decreasing volatility. The implementation point of the present invention is to reduce the influence of the input fluid pressure fluctuation on the non-connected suspended valve stem 30 and increase the reverse drive induction of the self-balancing valve head 21 of the drive valve membrane 20 by the input fluid pressure fluctuation.

[0096] See also Fig.12, in the first group of tests, when the low set value of the actual inlet pressure is 2 bar, the air pressure in the top air pressure chamber 81 is adjusted until the low initial adjustment value of the actual outlet pressure is 1 bar as the adjustment end. Without adjusting the top air pressure, when the actual inlet pressure is 3, 4, 5, 6, 7, 8 bar respectively, the values of the actual outlet pressure are detected, and the obtained increasing volatility x are 2.0%, 2.5%, 2.7%, 2.5%, 2.6%, 2.5% respectively, not exceeding an increasing volatility of 5%. On the other hand, when the high set value of the actual inlet pressure is 8 bar, the air pressure in the top air pressure chamber 81 is adjusted until the low initial adjustment value of the actual outlet pressure is 1 bar as the adjustment end. Without adjusting the top air pressure, when the actual inlet pressure is 7, 6, 5, 4, 3, 2 bar respectively, the values of the actual outlet pressure are detected, and the obtained decreasing volatility y are -2.0%, -2.5%, -2.7%, -3.0%, -3.4%, -3.3% respectively, not exceeding a decreasing volatility of -5%. In the second group of tests, when the low set value of the actual inlet pressure is 3 bar, the air pressure in the top air pressure chamber 81 is adjusted until the low initial adjustment value of the actual outlet pressure is 2 bar as the adjustment end. Without adjusting the top air pressure, when the actual inlet pressure is 4, 5, 6, 7, 8 bar respectively, the values of the actual outlet pressure are detected, and the obtained increasing volatility x are 2.0%, 2.5%, 3.3%, 3.0%, 3.0% respectively, not exceeding an increasing volatility of 5%. On the other hand, when the high set value of the actual inlet pressure is 8 bar, the air pressure in the top air pressure chamber 81 is adjusted until the low initial adjustment value of the actual outlet pressure is 2 bar as the adjustment end. Without adjusting the top air pressure, when the actual inlet pressure is 7, 6, 5, 4, 3 bar respectively, the values of the actual outlet pressure are detected, and the obtained decreasing volatility y are -2.0%, -2.0%, -2.7%, -3.0%, -3.4% respectively, not exceeding a decreasing volatility of -5%. The subsequent tests of other groups of tests can be compared with Fig.12 The subsequent tests. Therefore, the pilot-operated pressure reducing valve of the example of the present invention has a protective effect of self-suppressing the fluctuation of the fluid input pressure, and its increasing volatility x or / and decreasing volatility y will approach zero with lower values (0 < x ≤ 10.0%, -10.0% ≤ y < 0), which is better than that of the traditional pressure reducing valve (the increasing rate is about 20% or higher).

[0097] In a preferred example of the non-connected suspended valve stem 30, refer to again Figure 2 , Figure 3 And Figure 4 , can be compared with Figure 6The pressure reducing valve head 31 has an inverted cone slope to reduce the lateral flow impact of the input fluid on the non-connected suspended valve stem 30. The inverted cone slope of the pressure reducing valve head 31 can reduce the shaking of the lower guide column 34 under the fluctuation of the input fluid pressure, and avoid the direct up and down force exerted on the pressure reducing valve head 31 by the input fluid pressure fluctuation. This shape can slow down the force exerted on the pressure reducing valve head 31 by the input fluid pressure fluctuation, but can sensitively adjust the opening of the pressure reducing valve head 31 due to the fluctuation of the output fluid pressure.

[0098] In the preferred example of the embodiment of the pressure regulating valve, see Figure 2 , Figure 3 and Figure 4 , can be used with the control Figure 7 The pilot-operated pressure reducing valve further comprises: a floating adjustment seat 50, which is arranged on the elastic element 40 and elastically contacts the lower guide column 34, and is used to transmit the upward elastic force of the elastic element 40 to the non-connected suspended valve stem 30; a guide hole 51 is formed on the upper surface of the floating adjustment seat 50 to elastically contact the bottom end of the lower guide column 34; the guide hole 51 has an inner R angle, and the bottom end of the lower guide column 34 has an outer R angle, and the inner R angle is larger than the outer R angle, so as to facilitate the axial alignment of the lower guide column 34 and facilitate the floating adjustment seat 50 to be separated from the lower guide column 34 during assembly. By utilizing the structure and connection relationship of the floating adjustment seat 50, the floating adjustment seat 50 can well withstand the upward elastic force of the elastic element 40, and act as a medium to apply force to the non-connected suspended valve stem 30, so as to move the pressure reducing valve head 31 in the direction of reducing the opening, so as to increase the pressure reducing amplitude. In a more preferred example, by utilizing the difference between the inner R angle of the guide hole 51 of the floating adjustment seat 50 and the outer R angle at the bottom end of the lower guide post 34 of the non-connected suspended valve stem 30, the non-connected suspended valve stem 30 is deformed by external force, and the axial direction of the lower guide post 34 is changed preferentially, so that a large stress is not directly generated on the connection between the upper guide post 32 and the self-balancing valve head 21. After the sudden external force is eliminated or reduced, based on the difference between the inner and outer R angles, the lower guide post 34 is guided by the floating adjustment seat 50, so that the lower guide post 34 can be gradually reset to the axial direction. Therefore, the connection between the upper guide post 32 of the non-connected suspended valve stem 30 and the self-balancing valve head 21 does not require a fixed mechanical connection, and is not easy to skew or fall off. It can be seen from this that when the fluid input pressure fluctuates, the upper guide post 32 is not easy to shake or skew relative to the lower guide post 34. The skewness of the end of the lower guide post 34 can be regarded as the first section of tortuous deformation under the influence of the fluctuation of the fluid input pressure.

[0099] In a preferred embodiment of the floating adjustment seat 50, see Figure 2 , Figure 3 and Figure 4 , can be used with the control Figure 7, an adjusting ball end 52 extends from the bottom of the floating adjustment seat 50 and is nested in the elastic element 40. The elastic element 40 can be a compression spring, and the surface can have an anti-corrosion coating. The top of the elastic element 40 evenly applies force to the table of the floating adjustment seat 50 with a guide hole 51. By using the adjusting ball end 52 of the floating adjustment seat 50, the floating adjustment seat 50 can slide axially in the bottom elastic chamber 71 of the main valve 10 with margin to achieve axial alignment of the lower guide column 34. The adjusting ball end 52 and the outer R angle of the bottom end of the lower guide column 34 form a double reciprocating bendable and resettable structure to absorb the pressure fluctuation of the input flow channel 11, so as to avoid directly acting on the junction between the top of the upper guide column 32 and the self-balancing valve head 21, and to avoid the occurrence of the non-connected suspended valve stem 30 being unable to automatically reset after bending. In a more preferred example, a sleeve 73 is provided at the center of the lower valve seat 70 of the main valve 10 for guiding the sliding of the adjusting ball end 52 of the floating adjusting seat 50, and the elastic element 40 is sleeved on the outer diameter of the sleeve 73. By using the central sleeve 73 of the lower valve seat 70, the elastic element 40 can provide an upward elastic force that is not deflected in the longitudinal direction, so as to drive the floating adjusting seat 50 to be guided toward the axis even if it is deflected, and limit the sliding point of the adjusting ball end 52 of the floating adjusting seat 50 to be located at the axis center. The skewness of the terminal end of the adjusting ball end 5 of the floating adjusting seat 50 can be regarded as the second stage of tortuous deformation under the influence of the fluctuation of the fluid input pressure, which is in the opposite direction to the first stage of deformation mentioned above, and the combination of the top air pressure chamber 81 and the bottom elastic chamber 71 has the effect of correcting and straightening. In the self-balancing process, the top air pressure chamber 81 is a relatively closed space. Based on the different lifting positions of the self-balancing valve head 21, the air pressure value of the top air pressure chamber 81 will also vary, that is, the downward air pressure is a relative variable. The elastic element 40 of the bottom elastic chamber 71 can provide a relatively fixed elastic force within the limited lifting distance of the pressure reducing valve head 31. Therefore, after two stages of tortuosity, it can gradually self-correct and guide, and can overcome the fluctuation peaks of the fluid input pressure. When the fluid input pressure increases or decreases to a new value, the self-balancing valve head 21 will naturally adjust to a new equilibrium position, so that the fluid output pressure is more stable. In this example, the elastic element 40, the floating adjustment seat 50 and the lower guide column 34 of the non-connected suspended valve stem 30 cooperate to form a concentricity offset floating adjustment structure, which can offset the torque misalignment caused by the verticality tolerance of the elastic element 40, and ensure the sealing effect of the pressure reducing valve head 31 opening and closing the sealing surface of the closed valve port 13. More specifically, the adjustment ball end 52 of the floating adjustment seat 50 can reduce friction under structural interaction, allowing the elastic element 40 to promote the floating adjustment seat 50 under the verticality tolerance to be eccentric within a certain range.

[0100] In a preferred embodiment of the non-connected suspended valve stem 30, see Figure 2 , Figure 3 and Figure 4 , can be used with the control Figure 6 , the top end of the upper guide column 32 is tightly fitted in the axial hole of the self-balancing valve head 21; when the elastic element 40 lifts the non-connected suspended valve stem 30 to the highest point, the pressure reducing valve head 31 closes the airtight valve port 13, and the self-balancing valve head 21 is not enough to break away from the gap ring 14. Therefore, the condition for the pressure reducing valve head 31 to close the airtight valve port 13 is defined as the non-connected suspended valve stem 30 rises to the top dead center of the highest point, and the self-balancing valve head 21 still cannot break away from the gap ring 14, so the gap ring 14 of the main valve 10 can play a sufficient role in guiding and preventing the self-balancing valve head 21 of the driving valve membrane 20 from falling off during the whole process of pressure reduction and stabilization.

[0101] In a preferred embodiment of the main valve 10, refer to FIG. Figure 3 and Figure 4 , and matched with the control Fig. 9 , the opening of the notch ring 14 faces the entrance of the input flow channel 11, and the periphery of the notch ring 14 forms a flow channel annular groove 15 that can communicate with the output flow channel 12. By utilizing the design of the opening direction of the notch ring 14 and the flow channel annular groove 15, the overall flow channel path is the input flow channel 11, the activity space of the pressure reducing valve head 31 below the closed valve port 13, the closed valve port 13, the notch ring 14, the flow channel annular groove 15 to the output flow channel 12, so that the flow channel space 61 is clean and has no dead zone. The closed valve port 13 can specifically form a knife-edge sealing end face on the periphery of the lower ring mouth, which has a small sealing contact cross section, so that when the opening and closing sealing surface of the pressure reducing valve head 33 made of PTFE material contacts the flow channel knife-edge sealing end face of the closed valve port 13, no particles will be generated due to pressing.

[0102] In a more specific preferred example of the main body valve 10 and the non-connected suspended valve stem 30, refer to FIG. Figure 3 and Figure 4, the increase of air pressure in the top air pressure chamber 81 or / and the decrease of fluid pressure in the output flow channel 12 can make the self-balancing valve head 21 move downward. When the non-connected suspended valve stem 30 sinks to the lowest point, the shape and thickness of the self-balancing valve head 21 cannot close the gap ring 14; the elastic force of the elastic element 40 pushes up or / and the increase of fluid pressure in the input flow channel 11 can raise the non-connected suspended valve stem 30. When the non-connected suspended valve stem 30 rises to the highest point, the shape of the pressure reducing valve head 31 can close the closed valve port 13. By utilizing the shape structure and mutual relationship of the self-balancing valve head 21, the air pressure in the top air pressure chamber 81 or the change of fluid pressure in the output flow channel 12 can be sensed, and it is defined that the descending stop point of the self-balancing valve head 21 cannot make the self-balancing valve head 21 close the gap ring 14, and it is also defined that the ascending stop point of the self-balancing valve head 21 can make the shape of the pressure reducing valve head 31 close the closed valve port 13. Therefore, when the air in the top air pressure chamber 81 is extracted, the valve of the pilot pressure reducing valve can be closed naturally. In a more specific example, a downward flange is formed around the closed valve port 13 to increase the sealing effect of the pressure reducing valve head 31 .

[0103] In a preferred embodiment of the driving valve membrane 20, refer to FIG. Figure 3 and Figure 4 , with control Figure 8 The outer ring edge of the self-balancing valve head 21 is connected with a stop ring 22, which is larger than the outer diameter of the notch ring 14. The stop ring 22 will have a relatively good pressure sensing effect. When the stop ring 22 contacts the upper edge of the notch ring 14, it indicates that the non-connected suspended valve stem 30 has sunk to the lowest point, and the valve opening is maximum at this time. The stop ring 22 also extends above the flow channel annular groove 15, so that the fluid pressure from the output flow channel 12 can reduce the fluctuation energy acting on the drive valve membrane 20, and the self-balancing valve head 21 automatically moves down slightly. The stop ring 22 structure and mutual relationship of the self-balancing valve head 21 are used to determine the mechanism of the descending stop point of the self-balancing valve head 21, and the fluid pressure fluctuation of the output flow channel 12 will also change the position of the self-balancing valve head 21, producing a self-balancing effect and stabilizing the fluid pressure fluctuation of the output flow channel 12.

[0104] In a preferred embodiment of the main valve 10, see Figure 1 , Figure 2 and Figure 3 , with control Figures 9 to 11The main valve 10 includes a middle valve seat 60, a lower valve seat 70 and an upper valve cover 80. The middle valve seat 60 provides the input flow channel 11, the output flow channel 12, the closed valve port 13 and the notch ring 14; the lower valve seat 70 is combined with the lower part of the middle valve seat 60, and fixes the first peripheral ring portion 35 of the diaphragm 33 to form a bottom elastic chamber 71 for accommodating the elastic element 40, and a vent hole 72 is opened on one side of the lower valve seat 70, which is connected to the bottom elastic chamber 71 where the elastic element 40 is located; the upper valve cover 80 is combined with the upper part of the middle valve seat 60, and fixes the second peripheral ring portion 23 of the drive valve membrane 20 to form a top air pressure chamber 81. By utilizing the combination relationship of the middle valve seat 60, the lower valve seat 70 and the upper valve cover 80, the main valve 10 can fix the first peripheral ring portion 35 of the diaphragm 33 and the second peripheral ring portion 23 of the driving valve membrane 20 in a combined manner, effectively separating the top air pressure chamber 81, the bottom elastic chamber 71 and the flow channel space 61 therebetween. The driving valve membrane 20 has the functions of a sensing membrane and an isolation membrane, and the diaphragm 33 only has the function of an isolation membrane. Specifically, a screw thread can be provided on the exhaust passage of the vent hole 72, and in an acid mist environment, the exhaust passage can be led out with a hose to ensure that the elastic element 40 is not in direct contact with the external environment.

[0105] In a more specific preferred example of the main body valve 10, see Figure 3 and Fig.10 An upper fixed annular groove 62 is provided above the middle valve seat 60 for engagement with the peripheral frame of the driving valve membrane 20, and a lower fixed annular groove 63 is provided below the middle valve seat 60 for engagement with the peripheral frame of the diaphragm 33. The driving valve membrane 20 closes the upper opening of the middle valve seat 60, and the diaphragm 33 closes the lower opening of the middle valve seat 60 to form a flow channel space 61. The upper fixed annular groove 62 and the lower fixed annular groove 63 are used to increase the fixing force and anti-leakage characteristics of the peripheral frame of the driving valve membrane 20 and the peripheral frame of the diaphragm 33.

[0106] In a more specific preferred example of a double membrane, see Figure 3 , Figure 4 And compare Figure 8 and Figure 6 The peripheral frame of the driving valve film 20 has a lower protruding edge corresponding to the upper fixed ring groove 62, and the peripheral frame of the diaphragm 33 has an upper protruding edge corresponding to the lower fixed ring groove 63. The lower protruding edge and the upper protruding edge are used to reduce the leakage of the flow channel space 61 to the top air pressure chamber 81 and the leakage to the bottom elastic chamber 71.

[0107] The embodiment of the present invention further provides a semiconductor manufacturing equipment, including the pilot pressure reducing valve as described above (such as Figure 1As shown in the figure, the working fluid output by the pilot pressure reducing valve and introduced into the equipment machine is continuously at a stable fluid output pressure, and will not be adversely affected by the external fluid input pressure fluctuation, which is conducive to stabilizing the production parameters of semiconductor manufacturing and maintaining good quality control. The embodiment of the present invention can meet the ultra-pure cleanliness required by semiconductors, and can prevent the outflow of grease, metal ions, and contaminated particles in the flow channel space 61. This is because no sealing ring is required in use, and naturally there is no defect caused by the friction of the sealing ring. The driving valve membrane 20 located above the flow channel space 61 and the non-connected suspended valve stem and its diaphragm 33 located relatively below the space can be specifically made of ultra-pure PTFE (polytetrafluoroethylene), and the main valve 10 can be specifically made of ultra-pure PFA (soluble polytetrafluoroethylene). The bottom elastic chamber 71 and the top air pressure chamber 81 are isolated upper and lower structural chambers, which can ensure the cleanliness of the flow medium in the flow channel space 61 without pollution. It is specifically suitable for pressure reducing valves with cleanliness requirements for semiconductor ultra-pure chemicals and electronic ultra-pure water systems.

[0108] See also Figure 1 , Figure 3 and Figure 4In the initial adjustment stage of the pilot-operated pressure reducing valve, the compressed air pressure P1 of the top air pressure chamber 81 is adjusted through the pressurized hole 82 above the main valve 10, and the opening of the pressure reducing valve head 31 of the non-connected suspended valve stem 30 in the main valve 10 relative to the closed valve port 13 of the main valve 10 is controlled to adjust the fluid output pressure of the fluid medium to stabilize the fluid supply. When the opening is smaller (the self-balancing valve head 21 rises), the fluid output pressure of the medium is smaller, until the initially set pressure reducing valve setting value. During the actual decompression stage, the fluid output pressure P4 of the output channel 12 will also act on the bottom of the stop ring 22 of the drive valve membrane 20. When the fluid output pressure P4 of the output channel 12 is lower than the initial value, the stop ring 22 and the self-balancing valve head 21 connected thereto will be pulled down, and the pressure reducing valve head 31 will be synchronously linked to move downward to expand the valve opening. Therefore, the deficiency of the fluid output pressure P4 can be compensated, and the formula for expanding the valve is P1> (P4+P2+P3'), where P1 is the compressed air pressure from top to bottom in the top air pressure chamber 81, P4 is the fluid output pressure in the channel annular groove 15, P2 is the upward fixed elastic force applied by the elastic element 40, and P3' is the part of the fluid input pressure of the input channel 11 locally applied to the self-balancing valve head 21 (affected by the positive influence of the valve opening, the lower the height of the pressure reducing valve head 31, the larger the valve opening). In the equilibrium state, P1=(P4+P2+P3'). With the different height positions of the self-balancing valve head 21, the compressed air pressure P1 is a regular variable, the fixed elastic force P2 is a relatively constant elastic force, the local fluid input pressure P3' is a random variable in the actual production process and is positively affected by the valve opening, and P4 is the fluid output pressure in the flow channel ring groove 15, which should remain stable. For example, in actual operation, the fluid input pressure P3 fluctuates. With the change of the position of the self-balancing valve head 21, the low and high positions (corresponding to the valve opening size) of the pressure reducing valve head 31 also change synchronously, affecting the local fluid input pressure P3'. The compressed air pressure P1 also has a compensation effect. When the self-balancing valve head 21 dynamically adjusts to a new position, the fluid output pressure P4 remains relatively stable. When the fluid input pressure P3 becomes extremely large, the self-balancing valve head 21 rises, the pressure reducing valve head 31 is close to closing the sealed valve port 13, and the fluid output pressure P4 is suppressed and stabilized.

[0109] See also Fig.13 , Figure 2 , Figure 3 Corresponding to individual components Figures 6 to 11 The embodiment of the present invention further provides a method for assembling a pilot-operated pressure reducing valve, comprising the following steps:

[0110] Step S1, installing the driving valve membrane 20 at the middle top of the main valve 10; specifically, the second peripheral ring portion 23 (which can be formed by the diaphragm flange) of the driving valve membrane 20 is pressed into the upper fixed ring groove 62 of the center valve seat 60, and the two form an interference fit;

[0111] Step S2, installing the non-connected suspended valve stem 30 in the main valve 10, and the diaphragm 33 of the non-connected suspended valve stem 30 is limited to the bottom of the main valve 10 to form a flow channel space 61; specifically, the first peripheral ring portion 35 (which can be formed by the diaphragm flange) of the diaphragm 33 of the non-connected suspended valve stem 30 is aligned with the lower fixed ring groove 63 of the middle valve seat 60 and pressed into, and at the same time, the first peripheral ring portion 35 of the diaphragm 33 of the middle valve seat 60 is made to fit in an interference fit;

[0112] Step S3, setting the elastic element 40 at the bottom of the main valve 10; specifically, placing the elastic element 40 along the sleeve 73 of the lower valve seat 70;

[0113] Step S4, forming a bottom elastic chamber 71 of the main valve 10 outside the flow channel space 61, so that the lower guide column 34 of the non-connected suspended valve stem 30 can receive the upward push elastic force of the elastic element 40; specifically, the floating adjustment seat 50 is placed along the adjustment ball end 52 of the lower valve seat 70;

[0114] Step S5, forming a top air pressure chamber 81 of the main valve 10 outside the flow channel space 61, so that the upper guide column 32 of the non-connected suspended valve stem 30 can receive the downward pushing gas pressure of the driving valve membrane 20; wherein, in the process from step S1 to step S5, the self-balancing valve head 21 of the driving valve membrane 20 is always guided and slid on the notch ring 14 of the main valve 10; specifically, using the connecting rod 91 to align the above components with the diaphragm guide column holes of each component, and combine them to the connecting seat 92 on the other end face of the main valve 10, to realize the combined assembly of the main valve 10, and the dust cover 93 can be installed on its connecting end face; specifically, the upper valve cover 80 and the valve upper air cavity cover on the surface are installed into the assembly.

[0115] The implementation principle of this method example is to manufacture a pilot pressure reducing valve driven by a mechanical structure without external force by utilizing steps S1 to S5, so as to achieve the protective effect of stable supply of fluid output pressure and will not be sensitively affected by fluctuations in fluid input pressure and produce adverse effects.

[0116] In a preferred example, the main valve 10 in steps S1 to S3 specifically includes a middle valve seat 60, the main valve 10 in step S4 further includes a lower valve seat 70 combined with the bottom of the middle valve seat 60, and the main valve 10 in step S5 further includes an upper valve cover 80 combined with the top of the middle valve seat 60, a vent hole 72 is opened on one side of the lower valve seat 70, and is connected to the bottom elastic chamber 71 where the elastic element 40 is located, and the assembly method further includes: connecting the exhaust pipe to the vent hole 72. The lower valve seat 70 and the upper valve cover 80 are respectively and sequentially combined at the bottom and the top of the middle valve seat 60 to construct a bottom elastic chamber 71 with a fixed elastic force at the bottom of the middle valve seat 60 and a top air pressure chamber 81 with an adjustable air pressure at the top of the middle valve seat 60. During the assembly process from step S2 to step S3, since the top air pressure chamber 81 has not yet been constructed, the non-connected suspended valve stem 30 can always maintain the shape of the pressure reducing valve head 31 closing the closed valve port 13. The non-connected suspended valve stem 30 is relatively stable and does not shake during the assembly process, reducing the possible defects of fluid leakage caused by improper assembly operations.

[0117] The embodiments of this specific implementation method are all preferred embodiments for facilitating the understanding or implementation of the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention. All equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A pilot pressure reducing valve for semiconductor wet process, characterized in that: include: A main body valve is provided with an input flow channel, an output flow channel, a closed valve port connecting the input flow channel and the output flow channel, and a notch ring located above the closed valve port, and an elastic element is provided at the bottom of the main body valve; A driving valve membrane for air pressure regulation is arranged on the top of the main valve to separate a top air pressure cavity and a flow channel space from top to bottom, and the driving valve membrane has a self-balancing valve head aligned and adapted to the notch ring; A non-connected suspended valve stem, comprising a pressure reducing valve head capable of closing the sealed valve port, an upper guide post arranged on the pressure reducing valve head, a diaphragm arranged under the pressure reducing valve head, and a lower guide post located below the diaphragm, wherein the upper guide post only contacts the self-balancing valve head of the driving valve diaphragm to receive the downward-pushing gas pressure of the driving valve diaphragm, and the lower guide post receives the upward-pushing elastic force of the elastic element; when the pressure fluctuation of the fluid from the input flow channel is increasing and partially acts on the self-balancing valve head, the self-balancing valve head automatically moves slightly upward to reduce the opening of the pressure reducing valve head; when the pressure fluctuation of the fluid from the input flow channel is decreasing and partially acts on the self-balancing valve head, the self-balancing valve head automatically moves slightly downward to expand the opening of the pressure reducing valve head; The top end of the upper guide column is tightly fitted in the axial hole of the self-balancing valve head; when the elastic element lifts the non-connected suspended valve stem to the highest point, the pressure reducing valve head closes the closed valve port, and the self-balancing valve head is not enough to break away from the gap ring; The pilot-operated pressure reducing valve further comprises: a floating adjustment seat, which is arranged on the elastic element and elastically contacts with the lower guide column, and is used to transmit the upward elastic force of the elastic element to the non-connected suspended valve stem; a guide hole is formed on the upper surface of the floating adjustment seat to elastically contact the bottom end of the lower guide column; the guide hole has an inner R angle, and the bottom end of the lower guide column has an outer R angle, and the inner R angle is larger than the outer R angle, so as to facilitate the axial alignment of the lower guide column and facilitate the floating adjustment seat to be separated from the lower guide column; the pressure reducing valve head has an inverted cone slope to reduce the lateral flow impact of the input fluid on the non-connected suspended valve stem; an adjusting ball end extends from the bottom of the floating adjustment seat and is nested in the elastic element; the end skew of the lower guide column is the first section of tortuous deformation under the influence of the fluctuation of the fluid input pressure, and the end skew of the adjusting ball end of the floating adjustment seat is the second section of tortuous deformation under the influence of the fluctuation of the fluid input pressure, and the second section of tortuous deformation is in the opposite direction to the first section of deformation.

2. The pilot-operated pressure reducing valve according to claim 1, characterized in that: The opening of the gap ring faces the inlet of the input flow channel, and a flow channel annular groove that can communicate with the output flow channel is formed on the periphery of the gap ring.

3. The pilot-operated pressure reducing valve according to claim 2, characterized in that: The increase in air pressure in the top air pressure chamber and / or the decrease in fluid pressure in the output flow channel can move the self-balancing valve head downward. When the non-connected suspended valve stem sinks to the lowest point, the shape and thickness of the self-balancing valve head cannot close the notch ring. The elastic force of the elastic element pushes up and / or the increase in fluid pressure in the input flow channel can raise the non-connected suspended valve stem. When the non-connected suspended valve stem rises to the highest point, the shape of the pressure reducing valve head can close the closed valve port.

4. The pilot-operated pressure reducing valve according to claim 3, characterized in that: The outer ring edge of the self-balancing valve head is connected to a stop ring, which is larger than the outer diameter of the notch ring. When the stop ring abuts against the upper edge of the notch ring, the non-connected suspended valve stem sinks to the lowest point; the stop ring also extends above the flow channel ring groove to reduce the fluctuation energy of the fluid pressure from the output flow channel acting on the drive valve membrane, and the self-balancing valve head automatically moves downward slightly.

5. The pilot-operated pressure reducing valve according to any one of claims 1 to 4, characterized in that: The main valve comprises: The middle valve seat provides the input flow channel, the output flow channel, the closed valve port and the gap ring; A lower valve seat is combined with the lower part of the middle valve seat and fixes the first peripheral ring part of the diaphragm to form a bottom elastic chamber for accommodating the elastic element. A vent hole is opened on one side of the lower valve seat and connected to the elastic chamber where the elastic element is located. The upper valve cover is combined above the middle valve seat and fixes the second peripheral ring portion of the driving valve membrane to form a top air pressure chamber.

6. The pilot-operated pressure reducing valve according to claim 5, characterized in that: An upper fixed ring groove is provided above the middle valve seat for the peripheral frame of the driving valve membrane to be engaged, and a lower fixed ring groove is provided below the middle valve seat for the peripheral frame of the diaphragm to be engaged. The driving valve membrane closes the upper opening of the middle valve seat, and the diaphragm closes the lower opening of the middle valve seat to form a flow channel space; the peripheral frame of the driving valve membrane has a lower protruding edge corresponding to the upper fixed ring groove, and the peripheral frame of the diaphragm has an upper protruding edge corresponding to the lower fixed ring groove.

7. The pilot-operated pressure reducing valve according to claim 5, characterized in that: A sleeve is provided at the center of the lower valve seat for guiding the sliding of the adjusting ball end of the floating adjusting seat, and the elastic element is sleeved on the outer diameter of the sleeve.

8. A semiconductor manufacturing equipment, characterized in that: It comprises a pilot-operated pressure reducing valve as described in any one of claims 1 to 7, which is used to automatically stabilize the fluid pressure of the working fluid continuously supplied by the output flow channel.

9. An assembly method of a pilot-operated pressure reducing valve as claimed in any one of claims 1 to 7, characterized in that: include: S1. Install the drive valve diaphragm at the middle top of the main valve; S2, installing a non-connected suspended valve stem in the main valve, wherein the diaphragm of the non-connected suspended valve stem is limited to the bottom of the main valve to form a flow channel space; S3, setting an elastic element at the bottom of the main valve; S4, forming a bottom elastic chamber of the main valve outside the flow channel space, so that the lower guide column not connected to the suspended valve stem can receive the upward push elastic force of the elastic element; S5. Form a top air pressure chamber of the main valve outside the flow channel space so that the upper guide column of the non-connected suspended valve stem can receive the downward pushing gas pressure of the driving valve membrane; wherein, during the process from step S1 to step S5, the self-balancing valve head of the driving valve membrane always slides on the notch ring of the main valve.

10. The method for assembling a pilot-operated pressure reducing valve according to claim 9, characterized in that: The main valve in steps S1 to S3 specifically includes a middle valve seat, the main valve in step S4 also includes a lower valve seat combined with the bottom of the middle valve seat, and the main valve in step S5 also includes an upper valve cover combined with the top of the middle valve seat. A vent is provided on one side of the lower valve seat, which is connected to the bottom elastic chamber where the elastic element is located. The assembly method also includes: connecting an exhaust pipe to the vent.

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