WO2022151818A1

WO2022151818A1 - High-precision and large-pressure-reduction-ratio automatic pressure-regulating gas pressure-stabilizing and pressure-reducing combined valve

Info

Publication number: WO2022151818A1
Application number: PCT/CN2021/129481
Authority: WO
Inventors: 赵健; 谢文; 何通; 刘建峰; 刘畅; 李磊磊
Original assignee: 北京卫星制造厂有限公司
Priority date: 2021-01-12
Filing date: 2021-11-09
Publication date: 2022-07-21
Also published as: CN112747156B; CN112747156A

Abstract

The present invention relates to a high-precision and large-pressure-reduction-ratio automatic pressure-regulating gas pressure-stabilizing and pressure-reducing combined valve. A two-stage pressure-reducing structure is used, and the high-precision output of pressure is achieved. A mechanical pressure-reducing valve is used in a first stage, and an electrical proportional pressure-reducing valve is used in a second stage. A reverse unloading type main body structure is used in the first-stage pressure-reducing valve, the gas pressure of an inlet pressure acting on a valve is balanced out, and thus, the influence of gas source pressure fluctuation is reduced. For the problem of a high upstream pressure, a metal diaphragm type structure is used in the first-stage pressure-reducing valve, thereby improving the pressure resistance capability. An electromagnetic proportional valve main body form is used in the second-stage pressure-reducing valve, the valve body uses a reverse unloading type structure, and thus, the interference of the inlet pressure is further reduced. Moreover, a proportional electromagnet driving element is used, and thus, the stability of an output pressure is ensured while ensuring a flow.

Description

A high-precision and large pressure-reducing ratio automatic pressure-regulating gas pressure-reducing combined valve

This application is required to be submitted to the China Patent Office on January 12, 2021, the application number is 202110037425.X, and the application name is "a high-precision and large pressure-reducing ratio automatic pressure-regulating gas pressure-reducing combined valve" Chinese patent application , the entire contents of which are incorporated herein by reference.

technical field

The invention belongs to the field of industrial valve design, and relates to a gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio and automatic pressure regulation.

Background technique

At present, the fuel cell gas supply system mostly adopts two methods: mechanical pressure regulating valve and pneumatic pressure regulating. When the pressure changes during use, the mechanical pressure regulating needs to be manually adjusted by the operator, or the method of pre-order adjustment is adopted, but this method is the same as above. The anti-interference ability of the downstream is poor. Pneumatic pressure regulation often requires an additional auxiliary air source for pressure control, the system is complex and the cost is high. At the same time, because an additional auxiliary air source system is added for control, the response speed of the pressure will inevitably decrease, and the reliability of the system will also be greatly reduced. reduce.

SUMMARY OF THE INVENTION

The technical problem solved by the invention is: to overcome the deficiencies of the prior art, and to propose a gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio and automatic pressure regulation.

The technical solution of the present invention is:

A high-precision and large pressure-reducing ratio automatic pressure-regulating gas pressure-reducing combined valve, comprising a primary pressure reducing valve and a secondary pressure reducing valve. Top plate, main spring, lower spring top plate, primary ejector rod, metal diaphragm assembly, primary valve assembly, primary valve spring, primary lower mounting seat, primary metal gasket; secondary pressure relief valve includes proportional solenoid , bellows assembly, secondary ejector rod, secondary guide damping block, adapter bracket, secondary valve assembly, secondary valve spring, base body, secondary metal gasket, secondary lower mounting seat and primary damping orifice plate;

The primary pressure reducing valve is installed on the right side of the base body, and the secondary pressure reducing valve is installed on the left side of the base body

Specifically, the primary valve assembly is in the form of a reverse unloading structure, a cylindrical stepped cavity is axially opened inside, the diameter of the upper cylinder is smaller than that of the lower cylinder, the primary valve spring is installed in the lower cylindrical cavity, and the primary valve spring is installed in the lower cylindrical cavity. The top of the valve assembly is designed with a boss, the boss has two inclined holes, and the two inclined holes penetrate through the axial cylindrical step cavity; the outer surface of the first-stage valve assembly is provided with a sealing groove, and the sealing ring and the sealing block are installed on the sealing groove. plate;

The first-level lower mounting seat is provided with a blind hole, and the first-level valve assembly is installed in the blind hole; the first-level lower mounting seat is installed on the base body, and a first-level metal gasket is installed between the first-level lower mounting seat and the base body;

The first-stage damping orifice plate is installed on the upper end stop hole on the right side of the base body by screws, and there is a clearance fit between the two. After being installed in place, the first-stage damping orifice plate is just in contact with the upper end face of the first-stage valve assembly;

The first-stage ejector rod is inserted into the guide hole of the first-stage damping orifice plate, and the metal diaphragm assembly is installed in the positioning groove on the right side of the base body, and is located above the first-stage damping orifice plate;

The lower top plate of the spring is installed on the metal diaphragm assembly, the main spring is installed on the upper side of the upper spring upper plate, the upper spring upper plate is installed on the upper side of the main spring, the upper cover of the primary valve is installed on the upper right side of the base body by screws, and the metal diaphragm assembly is located at the upper side of the main spring. Between the upper cover of the primary valve and the base body, the lower top plate of the spring, the main spring and the upper top plate of the spring are all located inside the upper cover of the primary valve;

The adjustment rod is connected with the upper cover of the primary valve through threads, and the lower end of the adjustment rod is in contact with the upper top plate of the spring;

The secondary valve assembly is in the form of a reverse unloading structure, with a cylindrical stepped cavity axially opened inside, the upper cylindrical diameter is smaller than the lower cylindrical diameter, the secondary valve spring is installed in the lower cylindrical cavity, and the secondary valve assembly is outside. There is a sealing groove on the surface, and a sealing ring and a sealing baffle are installed on the sealing groove; the top of the secondary valve assembly is machined with a V-shaped hole;

The secondary lower mounting seat is provided with a blind hole, and the secondary valve assembly is installed in the blind hole; the secondary lower mounting seat is installed on the base body, and a secondary metal gasket is installed between the secondary lower mounting seat and the base body ;

The secondary guide damping block is installed in the upper end stop hole on the left side of the base body through screws, and the guide length in the secondary guide damping block is 5 to 10 times the diameter of the inner hole of the guide hole;

The secondary ejector rod is installed in the guide hole of the secondary guide damping block; the lower side of the secondary ejector rod is tapered in shape, and a blind hole with a diameter of r1 is opened inside the lower side. The blind hole of r2, the blind hole of diameter r2 and the blind hole of diameter r1 pass through; the conical shape below the secondary ejector rod is in contact with the V-shaped hole at the top of the secondary valve assembly;

The bellows assembly includes a bellows, a lower support surface and an upper fixing surface, wherein the bellows is located in the middle, and the three are connected by welding; the upper fixing surface is machined with guide holes;

The bellows assembly is installed on the base body and is located above the secondary guide damping block; after being installed in place, the top of the secondary ejector rod is inserted into the guide hole on the fixed surface of the bellows assembly;

The adapter bracket is installed above the left side of the base body, and the proportional electromagnet is located above the bellows assembly and fixed on the base body;

A high pressure cavity is machined between the inlet on the right side of the base body, the primary valve port and the sealing groove of the primary or door assembly; a medium pressure cavity is machined between the primary valve port, the metal diaphragm assembly and the secondary valve port; the outlet on the right side of the base body , A low-pressure cavity is processed between the secondary valve port and the secondary or door assembly.

The first-stage valve assembly is in the form of vulcanized rubber, and the fluorine rubber is vulcanized on the metal skeleton. The upper cylindrical diameter of the inner axial cylindrical step cavity is 0.8~1.1mm, and the diameter of the two inclined holes at the boss is 0.5~0.8mm. .

The inner wall of the blind hole of the first-level lower mounting seat is sprayed with PTFE, and the thickness of PTFE is 20-30um. After spraying, the cooperation between the blind hole of the first-level lower mounting seat and the first-level valve assembly adopts a small clearance fit, and the gap is controlled between 4um and 4um. between 8um.

A knife-edge sealing ring is arranged in the middle of the annular area where the first-level lower mounting seat is in contact with the first-level metal gasket, the height of the knife-edge sealing ring is 0.15mm, and the knife-edge angle is 60°;

A "V-shaped" sealing waterline is arranged in the middle of the annular area where the base body is in contact with the primary metal gasket, the depth of the sealing waterline is 0.2, and the angle of the V-shaped angle is 60°.

The metal diaphragm assembly adopts a beryllium bronze metal diaphragm, and the beryllium bronze diaphragm adopts a sine wave embossing form. The upper and lower surfaces of the beryllium bronze metal diaphragm are welded with 0.9mm thick copper gaskets, between the copper gasket and the beryllium bronze metal diaphragm. The sealing performance is better than 1x10-9Pam3/s.

When the metal diaphragm assembly is installed in the positioning groove on the right side of the base body, the sine wave boss of the metal diaphragm assembly is installed downward;

On the surface of the metal diaphragm assembly in contact with the base body, two knife edge sealing rings are machined on the base body, the height of the knife edge sealing ring is 0.15mm, and the knife edge angle is 60°.

Two knife edge sealing rings are machined on the annular surface where the upper cover of the primary valve is in contact with the metal diaphragm assembly, the height of the knife edge sealing ring is 0.15mm, and the knife edge angle is 60°.

The secondary valve assembly is in the form of vulcanized rubber, and the fluorine rubber is vulcanized on the metal skeleton, and the upper cylindrical diameter of the inner axial cylindrical stepped cavity is 0.8-1.1 mm.

The inner wall of the blind hole of the secondary lower mounting seat is sprayed with PTFE, and the thickness of PTFE is 20-30um. The cooperation between the blind hole of the secondary lower mounting seat and the secondary valve assembly after spraying adopts a small clearance fit, and the gap is controlled between 4um and 4um. between 8um.

A secondary metal sealing gasket is installed between the secondary lower mounting seat and the base body, and a knife edge sealing ring is arranged in the middle of the annular area where the secondary lower mounting seat and the secondary metal sealing gasket are in contact. is 60;

There is a "V-shaped" sealing waterline in the middle of the annular area where the base body is in contact with the secondary metal gasket, the depth of the sealing waterline is 0.2, and the angle of the V-shaped angle is 60°.

The beneficial effects of the present invention compared with the prior art are:

The gas pressure-stabilizing and pressure-reducing combined valve of the present invention adopts a two-stage pressure-reducing structure to realize high-precision output of pressure. The first stage adopts a mechanical pressure reducing valve, and the second stage adopts an electric proportional pressure reducing valve.

In response to the problem of large changes in upstream pressure, the primary pressure reducing valve adopts a reverse unloading main structure to balance the air pressure acting on the valve assembly by the inlet pressure, thereby reducing the influence of fluctuations in the air source pressure. For the problem of high upstream pressure , The first-level pressure reducing valve adopts a metal diaphragm structure to improve the pressure resistance.

In view of the problem of adjustable downstream pressure and high precision, the secondary pressure reducing valve adopts the main body form of the electromagnetic proportional valve, and the valve body adopts the reverse unloading structure to further reduce the interference of the inlet pressure. On the premise of ensuring the flow, ensure the stability of the output pressure. Aiming at the problem of high output accuracy, the method of pressure closed-loop control is mainly adopted, the outlet pressure is collected by the pressure sensor, and the output force value of the proportional electromagnet is adjusted to ensure the stability and output accuracy of the output pressure.

The system of the invention is simple, the cost is low, and the pressure response speed is fast, which effectively improves the reliability of the system.

Description of drawings

Fig. 1 is a schematic diagram of a gas pressure-stabilizing and pressure-reducing combined valve of the present invention;

Figure 2 is a schematic diagram of spraying PTFE lubricating material on the sealing surface of the OR door assembly;

3 is a schematic diagram of a metal diaphragm assembly;

Figure 4 is a schematic diagram of the bellows assembly.

Detailed ways

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

The composition of the present invention is shown in Fig. 1, which adopts an integrated design, and all parts are installed on the base to form a highly integrated valve group.

The first-stage valve assembly 8 is in the form of vulcanized rubber, and the fluorine rubber is vulcanized on the metal frame. The first-stage valve assembly 8 adopts the reverse unloading structure form, and a cylindrical stepped cavity is processed inside. The diameter of the upper cylindrical cavity is smaller than that of the lower end column. The diameter of the cylindrical cavity at the upper end is 0.8~1.1mm, and two inclined holes are opened at the top boss of the primary valve assembly, and the diameter of the inclined holes is 0.5~0.8mm. The cylindrical stepped cavities in the direction run through each other.

The primary valve assembly 8 is provided with a sealing groove on the outer surface, a sealing ring and a sealing baffle are installed on the sealing groove, the sealing ring is made of fluorine rubber, and the sealing baffle is made of polytetrafluoroethylene. The diameter of the sealing ring is a φ1.8 sealing ring, and the depth of the sealing groove here is 1.5mm to 1.55mm.

The first-level lower mounting seat 10 is a metal part with blind holes processed inside. In order to reduce the friction between the first-level lower mounting seat 10 and the O-ring installed on the first-level valve assembly 8 during the movement process, the first-level lower mounting seat 10 is installed in The inner surface of the blind hole of the seat 10 is sprayed with PTFE, and the thickness of PTFE is 20-30um. It is required that the cooperation between the blind hole of the first-level lower mounting seat 10 and the first-level valve assembly 8 after spraying adopts a small clearance fit, and the gap is controlled at 4um to 8um.

The first-stage valve assembly 8 is installed in the blind hole on the first-stage lower mounting seat 10, and the first-stage valve spring 9 is installed between the two. The first-stage valve spring 9 is located under the column-shaped stepped cavity of the first-stage or door assembly. in the cylindrical cavity. The first-level lower mounting seat 10 is installed on the base body 19, and a first-level metal gasket 11 is installed between the first-level lower mounting seat 10 and the base body 19. The first-level metal gasket 11 is made of red copper and has a thickness of 1 mm. There is a knife-edge sealing ring in the middle of the annular area where the first-level lower mounting seat 10 and the first-level metal gasket 11 are in contact. There is a "V-shaped" sealing waterline in the middle, the depth of the sealing waterline is 0.2, and the angle of the V-shaped angle is 60°.

The primary damping orifice plate 22 is installed on the upper end stop hole on the right side of the base body 19 with clearance fit therebetween. Three M3 countersunk head screws are used to fix the primary damping orifice plate 22 and the base body 19 together. It is required that the first-stage damping orifice plate 22 is just in contact with the upper end face of the first-stage valve assembly 8 after being installed, so as to ensure that the rubber indentation depth of the first-stage valve assembly 8 is controlled between 0.2 and 0.3 mm.

The first-stage ejector rod 6 is inserted into the guide hole of the first-stage damping orifice plate 22, and a small gap is used between the two.

Metal diaphragm assembly 7 adopts beryllium bronze metal diaphragm with a thickness of 0.18mm. The beryllium bronze diaphragm is in the form of sine wave embossing to enhance its rigidity. By welding, the upper and lower surfaces of the beryllium bronze diaphragm are welded with a thickness of 0.9mm respectively. For copper gaskets, the tightness between the two is required to be better than 1x10-9Pam3/s. As shown in Figure 3.

The metal diaphragm assembly 7 is installed in the positioning groove on the right side of the base body 19, and a small clearance fit is adopted between the two. On the surface of the metal diaphragm assembly 7 in contact with the base body 19, two knife edges are machined on the base body 19. For the sealing pair, the height of the knife edge seal ring is 0.15mm, the knife edge angle is 60°, and the sine wave boss of the metal diaphragm is installed downward.

The under-spring top plate 5 is mounted on the metal diaphragm assembly 7 .

The main spring 4 is mounted on the upper side of the spring top plate 3 .

The spring top plate 3 is mounted on the upper side of the main spring 4 .

The primary valve upper cover 2 is installed on the upper side of the base body 19 and is connected by 6 M5 screws, and the metal diaphragm assembly 7 is installed between the primary valve upper cover 2 and the base body 19 . The adjusting rod 1 is connected with the upper cover 2 of the primary valve through threads, and the lower end protrusion of the adjusting rod 1 is in contact with the upper top plate 3 of the spring. The lower spring top plate 5 , the main spring 4 and the upper spring top plate 3 are located inside the upper cover 2 of the primary valve.

Similarly, two knife edge sealing rings are machined on the annular surface of the primary valve upper cover 2 in contact with the metal diaphragm assembly 7, the knife edge sealing ring height is 0.15mm, and the knife edge angle is 60°.

The secondary valve assembly 17 is in the form of vulcanized rubber, and the fluorine rubber is vulcanized on the metal skeleton. The secondary valve assembly 17 adopts the reverse unloading structure form, and a cylindrical stepped cavity is processed inside. The diameter of the upper cylindrical cavity is smaller than that of the lower end column. The diameter of the cylindrical cavity at the upper end is 0.8-1.1 mm. The top of the secondary valve assembly 17 is machined with a V-shaped hole.

The secondary valve assembly 17 is provided with a sealing groove on the outer surface, and a sealing ring is installed on the sealing groove, and the material of the sealing ring is fluorine rubber. The diameter of the sealing ring is a φ1.8 sealing ring, and the depth of the sealing groove here is 1.5mm to 1.55mm.

The secondary lower mounting seat 21 is a metal part. In order to reduce the friction between the secondary lower mounting seat 21 and the O-ring mounted on the secondary valve assembly 17 during the movement process, blinds are machined on the secondary lower mounting seat 21. The inner surface of the blind hole is sprayed with PTFE, and the thickness of PTFE is 20-30um. It is required that the cooperation between the blind hole of the secondary lower mounting seat 21 and the secondary valve assembly 17 after spraying adopts a small clearance fit, and the clearance is controlled at 4um to 8um.

The secondary valve assembly 17 is installed in the blind hole on the secondary lower mounting seat 21, and the secondary valve spring 18 is installed between the two. The secondary valve spring 18 is located in the cylindrical stepped cavity of the secondary valve assembly 17. in the cylindrical cavity at the lower end. The secondary valve assembly 17 is installed on the base body 19, and a secondary metal gasket 20 is installed on the secondary valve assembly 17 and the base body 19. The material of the secondary metal gasket 20 is red copper, with a thickness of 1 mm. There is a knife edge sealing ring in the middle of the annular area in contact with the secondary valve assembly 17 and the secondary metal gasket 20, the height of the knife edge sealing ring is 0.15mm, the knife edge angle is 60°, the base 19 and the secondary metal gasket 20 are in the middle of the annular area in contact with There is a "V-shaped" sealing waterline, the depth of the sealing waterline is 0.2, the angle of the V-shaped angle is 60°, and 6 M5 screws are used to connect the secondary lower mounting seat 17 and the base body 19 .

The secondary guide damping block 15 is installed in the upper end stop hole on the left side of the base body 19, and there is a clearance fit between the two.

The secondary ejector rod 14 is installed in the guide hole in the secondary guide damping block 15 . There is a φ0.8mm blind hole on the lower side of the secondary ejector rod 14, the shape of the lower side is conical, the hole depth is 10mm, and a single-sided φ0.8mm blind hole and an axial φ0.8mm blind hole are opened at the 10mm position. . The lower conical shape of the secondary ejector rod 14 is in contact with the V-shaped hole of the secondary valve assembly 17 .

The wall thickness of the bellows in the middle of the bellows assembly 13 is 0.12mm and the stiffness is 2N/mm. The bellows, the lower support surface and the upper fixed surface are welded together by welding. The welding method is laser welding to ensure that the leakage rate of the welding seal is better than 1x10-9Pam3/s..

The bellows assembly 13 is connected with the base body 19 to ensure that the guide holes on the upper fixing surface of the bellows assembly 13 are compatible with the secondary ejector rod 14 . A sealing structure is provided between the bellows assembly 13 and the base body 19 .

The adapter bracket 16 is installed on the upper left side of the base body 19 for connecting the proportional electromagnet 12 and the base body 19 . The three are fixed by 4 M5 screws.

As shown in Figure 1, a high-pressure cavity is machined between the inlet on the right side of the base, the primary valve port and the sealing groove of the primary or door assembly; a middle valve is machined between the primary valve port, the metal diaphragm assembly 7 and the secondary valve port Pressure cavity; a low pressure cavity is processed between the outlet on the right side of the base body, the secondary valve port and the secondary or door assembly.

The working principle of the present invention is as follows:

Internal flow path of primary valve:

The gas enters the high pressure chamber and enters the air outlet of the primary pressure reducing valve through the base body passage. The air outlet of the primary pressure reducing valve is communicated with the medium pressure chamber, and the outlet pressure is led to the lower chamber of the primary valve assembly for balancing the primary valve. The pressure difference between the upper and lower sides of the component. When the pressure on the outlet side increases, the metal diaphragm assembly 7 moves upward under pressure, and then compresses the main spring 4 to move upward. The amount of opening decreases, the flow rate increases, the pressure decreases, and the pressure behind the valve decreases; when the pressure on the outlet side decreases, the metal diaphragm assembly 7 moves downward under the push of the main spring 4, pushing the first-stage ejector to compress the first-stage valve assembly The downward movement increases the opening of the valve, reduces the flow rate, reduces the pressure drop, and increases the pressure behind the valve, thereby ensuring that the outlet pressure behind the valve remains relatively stable and has small pressure fluctuations.

Internal flow path of secondary valve:

Enter the medium pressure chamber and enter the valve air outlet through the flow path of the base body, wherein the valve outlet air outlet is communicated with the pressure-sensing chamber of the bellows assembly, and at the same time, the outlet pressure is induced to the lower end of the secondary valve assembly, which is used to balance the upper and lower parts of the secondary valve assembly. side pressure difference. Reduces outlet pressure fluctuations caused by upstream pressure changes. When the pressure on the outlet side increases, the bellows assembly moves upward under pressure, and then the main shaft of the compression proportional electromagnet moves upward. When the pressure on the outlet side decreases, the bellows assembly moves downward under the push of the main shaft of the proportional electromagnet, and pushes the valve thimble to compress the valve to move downward, making the valve port move downward. The opening of the valve increases, the flow rate decreases, the pressure drop decreases, and the pressure behind the valve increases, thereby ensuring that the outlet pressure behind the valve remains relatively stable and has small pressure fluctuations.

The electric adjustment of the outlet pressure is controlled by the output force of the proportional electromagnet, and the change of the output force of the proportional electromagnet is realized by controlling the change of the input power of the proportional electromagnet.

In the present invention, the gas pressure-reducing and pressure-reducing combined valve is composed of two stages. The internal valve component of the first-stage valve adopts a balanced valve structure and a metal diaphragm pressure-sensitive structure. The valve seal adopts fluorine rubber F108 for vulcanization treatment. The internal valve of the secondary valve also adopts a balanced valve structure, and the valve seal is vulcanized with fluorine rubber F108. The pressure-sensitive structure adopts the pressure-sensitive structure of welded bellows.

The seal at the valve structure adopts O-ring high-pressure seal, and the surface of the sealing pair in contact with the O-ring is sprayed with PTFE lubricating material to reduce the friction at the dynamic seal of the valve and reduce the hysteresis of dynamic characteristics caused by product friction. as shown in picture 2.

The metal diaphragm assembly adopts a welded structure, the main diaphragm is made of beryllium bronze material, and the upper and lower sides are welded with copper pads respectively. Through welding and metal sealing, the leakage rate of the product is improved. Beryllium bronze diaphragm is modified with sine wave to improve its stiffness characteristics.

The bellows assembly is in the form of welding, and the bellows, the mounting seat and the upper cover are welded together, and the bellows is in the form of a welded bellows (diaphragm), which has a small axial stiffness and a large displacement. It is beneficial to adjust the valve opening of the secondary valve. As shown in Figure 4.

The pressure adjustment of the secondary valve is adjusted by the proportional electromagnet, so that the output force value of the electromagnet fluctuates in the range of 2N under the large displacement change of the proportional electromagnet, thus ensuring the stability of the output pressure of the secondary valve.

The gas pressure-reducing and pressure-reducing combined valve of the invention adopts a two-stage pressure-reducing structure, and rationally designs the respective pressure-reducing ratios of the two-stage pressure-reducing, so as to realize the high-precision output of pressure. The first stage adopts a mechanical pressure reducing valve, and the second stage adopts an electric proportional pressure reducing valve.

In response to the problem of large upstream pressure changes, the primary pressure reducing valve adopts a reverse unloading main structure to balance the air pressure acting on the valve by the inlet pressure, thereby reducing the influence of fluctuations in the air source pressure. For the problem of high upstream pressure, The first-stage pressure reducing valve adopts a metal diaphragm structure to improve the pressure resistance.

Aiming at the problem of adjustable downstream pressure and high precision, the secondary pressure reducing valve adopts the main body form of the electromagnetic proportional valve, and the valve body adopts the reverse unloading structure to further reduce the interference of the inlet pressure. On the premise of ensuring the flow, ensure the stability of the output pressure. Aiming at the problem of high output accuracy, the method of pressure closed-loop control is mainly adopted, the outlet pressure is collected by the pressure sensor, and the output force value of the proportional electromagnet is adjusted to ensure the stability and output accuracy of the output pressure. In response to flow fluctuations, pressure sensing elements with welded bellows are used to achieve low additional stiffness and large linear displacement.

The invention solves the pressure precision control problem in the high-precision air supply system, can realize large pressure, and can realize the pressure output of 0.05-0.2MPa under the condition of input in a large range (0.4-8MPa), and the output pressure can be adjusted independently and adaptively. At the same time, the voltage regulation accuracy is guaranteed to be ±5KPa. Achieve 2.5% output accuracy of voltage regulator and pressure reducing valve. It solves the problem that the existing pressure reducing and regulating valve cannot realize self-adaptive adjustment, and at the same time further improves the output precision of the existing pressure reducing and regulating valve, and has functions such as automatic on-off.

Contents that are not described in detail in the specification of the present invention are well known to those skilled in the art.

Claims

A gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio and automatic pressure regulation is characterized in that it comprises a primary pressure reducing valve and a secondary pressure reducing valve, and the primary pressure reducing valve comprises a regulating rod (1), a Stage valve upper cover (2), upper spring top plate (3), main spring (4), lower spring top plate (5), first stage ejector rod (6), metal diaphragm assembly (7), first stage valve assembly (8) ), primary valve spring (9), primary lower mounting seat (10), primary metal gasket (11); secondary pressure reducing valve includes proportional solenoid (12), bellows assembly (13), secondary Ejector rod (14), secondary guide damping block (15), adapter bracket (16), secondary valve assembly (17), secondary valve spring (18), base body (19), secondary metal gasket (20) ), the secondary lower mounting seat (21) and the primary damping orifice plate (22);

The primary pressure reducing valve is installed on the right side of the base body, and the secondary pressure reducing valve is installed on the left side of the base body

Specifically, the primary valve assembly (8) is in the form of a reverse unloading structure, a cylindrical stepped cavity is axially opened inside, the diameter of the upper cylinder is smaller than the diameter of the lower cylinder, and the primary valve spring (9) is installed in the lower cylinder. In the cavity, a boss is designed on the top of the primary valve assembly (8), the boss has two inclined holes, and the two inclined holes penetrate through the axial cylindrical stepped cavity; the outer surface of the primary valve assembly (8) is provided with a The sealing groove, the sealing ring and the sealing baffle are installed on the sealing groove;

The first-level lower mounting seat (10) is provided with a blind hole, and the first-level shutter assembly (8) is installed in the blind hole; the first-level lower mounting seat (10) is mounted on the base body (19), and is installed under the first-level A primary metal gasket (11) is installed between the seat (10) and the base body (19);

The first-stage damping orifice plate (22) is installed on the upper end stop hole on the right side of the base body (19) by screws, and the two are in clearance fit. 8) The upper end face just touches;

The primary ejector rod (6) is inserted into the guide hole of the primary damping orifice plate (22), and the metal diaphragm assembly (7) is installed in the positioning groove on the right side of the base body, and is located above the primary damping orifice plate (22);

The lower spring top plate (5) is mounted on the metal diaphragm assembly (7), the main spring (4) is mounted on the upper side of the spring upper top plate (3), and the spring upper top plate (3) is mounted on the upper side of the main spring (4). The upper cover (2) of the first stage valve is installed on the upper right side of the base body (19) by screws, the metal diaphragm assembly (7) is located between the upper cover (2) of the first stage valve and the base body (19), and the lower spring top plate (5), The main spring (4) and the upper spring top plate (3) are both located inside the upper cover (2) of the primary valve;

The adjusting rod (1) is connected with the upper cover (2) of the primary valve through threads, and the lower end protrusion of the adjusting rod (1) is in contact with the upper top plate 3 of the spring;

The secondary valve assembly (17) is in the form of a reverse unloading structure, a cylindrical stepped cavity is axially opened inside, the upper cylindrical diameter is smaller than the lower cylindrical diameter, and the secondary valve spring (18) is installed in the lower cylindrical cavity. , the outer surface of the secondary valve assembly (17) is provided with a sealing groove, and a sealing ring and a sealing baffle are installed on the sealing groove; the top of the secondary valve assembly (17) is machined with a V-shaped hole;

The secondary lower mounting seat (21) is provided with a blind hole, and the secondary valve assembly (17) is installed in the blind hole; the secondary lower mounting seat (21) is mounted on the base body (19) and is installed under the secondary A secondary metal gasket (20) is installed between the seat (21) and the base body (19);

The secondary guide damping block (15) is installed in the upper end stop hole on the left side of the base body (19) by screws, and the guide length in the secondary guide damping block (15) is 5 to 10 times the diameter of the inner hole of the guide hole;

The secondary ejector rod (14) is installed in the guide hole of the secondary guide damping block (15); the lower side of the secondary ejector rod (14) has a conical shape, and a blind hole with a diameter of r1 is opened inside the lower side. A blind hole with a diameter of r2 is opened on the top side of the upper hole, and the blind hole with a diameter of r2 and a blind hole with a diameter of r1 pass through; the conical shape below the secondary ejector rod (14) and the secondary valve assembly (17) The V-shaped holes at the top are in contact;

The bellows assembly (13) includes a bellows, a lower support surface and an upper fixing surface, wherein the bellows is located in the middle, and the three are connected by welding; the upper fixing surface is machined with guide holes;

The bellows assembly (13) is installed on the base body (19) and is located above the secondary guide damping block (15); after being installed in place, the top of the secondary ejector rod (14) is inserted into the guide of the fixed surface on the bellows assembly (13) in the hole;

The adapter bracket (16) is installed above the left side of the base body (19), the proportional electromagnet (12) is located above the bellows assembly (13), and is fixed on the base body (19);

A high-pressure cavity is machined between the inlet on the right side of the base body, the first-stage valve port and the sealing groove of the first-stage or door assembly; a medium-pressure cavity is machined between the first-stage valve port, the metal diaphragm assembly (7) and the second-stage valve port; the base body A low pressure cavity is machined between the right outlet, the secondary valve port and the secondary or gate assembly.
A high-precision and large pressure-reducing ratio automatic pressure-regulating gas pressure-reducing combined valve according to claim 1, characterized in that: the first-stage valve assembly (8) is in the form of vulcanized rubber, and the fluorine rubber is vulcanized on the metal skeleton The upper cylindrical diameter of the inner axial cylindrical stepped cavity is 0.8-1.1 mm, and the diameter of the two inclined holes at the boss is 0.5-0.8 mm.
The gas pressure-stabilizing and pressure-reducing combined valve with automatic pressure regulation with high precision and large pressure-reducing ratio according to claim 1, characterized in that: the inner wall of the blind hole of the first-level lower mounting seat (10) is sprayed with polytetrafluoroethylene, polytetrafluoroethylene The thickness is 20-30um, and the cooperation between the blind hole of the first-level lower mounting seat after spraying and the first-level valve assembly adopts a small clearance fit, and the gap is controlled between 4um and 8um.
The gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio automatic pressure regulation according to claim 1, characterized in that: the first-level lower mounting seat (10) is in phase with the first-level metal gasket (11). A knife edge seal ring is arranged in the middle of the contacting annular area, the height of the knife edge seal ring is 0.15mm, and the knife edge angle is 60°;

A "V-shaped" sealing waterline is arranged in the middle of the annular area where the base body (19) is in contact with the primary metal gasket (11), the sealing waterline depth is 0.2, and the V-shaped angle is 60°.
The gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio according to claim 1, characterized in that: the metal diaphragm assembly (7) adopts a beryllium bronze metal diaphragm, and the beryllium bronze diaphragm adopts a beryllium bronze diaphragm. In the form of sine wave embossing, 0.9mm thick copper gaskets are welded on the upper and lower surfaces of the beryllium bronze metal diaphragm respectively, and the tightness between the copper gasket and the beryllium bronze metal diaphragm is better than 1x10-9Pam3/s.
The gas pressure-stabilizing and pressure-reducing combined valve with automatic pressure regulation with high precision and large pressure-reducing ratio according to claim 5, characterized in that: the metal diaphragm assembly (7) is installed in the positioning groove on the right side of the base body (19). When the sine wave boss of the metal diaphragm assembly (7) is installed downwards;

On the surface of the metal diaphragm assembly (7) in contact with the base body (19), two knife edge sealing rings are machined on the base body (19).
The gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio and automatic pressure regulation according to claim 1, characterized in that: the upper cover (2) of the primary valve is in contact with the metal diaphragm assembly (7). There are 2 knife edge sealing rings machined on the annular surface, the height of the knife edge sealing ring is 0.15mm, and the knife edge angle is 60°.
A high-precision and large pressure-reducing ratio automatic pressure-regulating gas pressure-reducing combined valve according to claim 1, characterized in that: the secondary valve assembly (17) is in the form of vulcanized rubber, and the fluorine rubber is vulcanized on the metal skeleton The upper cylindrical diameter of the inner axial cylindrical stepped cavity is 0.8-1.1 mm.
The gas pressure-stabilizing and pressure-reducing combined valve with high precision and large pressure-reducing ratio automatic pressure regulation according to claim 1, characterized in that: the inner wall of the blind hole of the secondary lower mounting seat (21) is sprayed with polytetrafluoroethylene, polytetrafluoroethylene The thickness is 20~30um. The cooperation between the blind hole of the secondary lower mounting seat after spraying and the secondary valve assembly adopts a small clearance fit, and the clearance is controlled between 4um and 8um.
The gas pressure-stabilizing and pressure-reducing combined valve with high-precision and large pressure-reducing ratio automatic pressure regulation according to claim 1, characterized in that: a second-stage lower mounting seat (21) and the base body (19) are installed between the second-stage lower mounting seat (21) and the base body (19). The metal gasket (20) is provided with a knife edge sealing ring in the middle of the annular area where the secondary lower mounting seat (21) is in contact with the secondary metal gasket (20), the knife edge sealing ring height is 0.15mm, and the knife edge angle is 60;

There is a "V-shaped" sealing waterline in the middle of the annular area where the base body (19) is in contact with the secondary metal gasket (20), the depth of the sealing waterline is 0.2, and the angle of the V-shaped angle is 60°.