High pressure air pressure reducing valve with overpressure protection

Abstract

The utility model discloses an air pressure reducing valve with overpressure protection, which comprises a shell, a poppet valve core, a return spring, a valve assembly one, a cushion block, a diaphragm, a pressure regulating nut, a pressure regulating nut, a pressure regulating spring, a cover, a spring support, a safety valve assembly, the shell has a stepped columnar cavity, and the inner diameter gradually increases from bottom to top and is respectively a high-pressure cavity, a low-pressure cavity and a pressure regulating cavity; the shell is provided with an inlet one and an outlet on both sides of the cavity axis, the inlet one and the outlet are coaxially arranged, the inlet one is connected with the cavity through a channel one, and the inlet two is arranged near the vertical channel one of the inlet end; one side of the shell vertical to the axis of the inlet one and the outlet is provided with a safety interface connected with the safety valve assembly. The structure has high sealing performance under the 45MPa continuous high-pressure environment and the -55 DEG C to 70 DEG C environment, has high pressure control precision, has high pressure reduction ratio, greatly improves the durability of the components, reduces the number of parts through integrated design, and significantly reduces the maintenance frequency, spare parts inventory and replacement time.

Description

Technical Field

[0001] This utility model relates to the field of aircraft air energy system technology, specifically to a high-pressure air pressure reducing valve with overpressure protection. Background Technology

[0002] Aircraft air power systems refer to systems that increase gas pressure and supply gas to other gas-using systems through decompression, which can effectively reduce the number and volume of gas cylinders, thereby reducing the overall weight of the aircraft and expanding the application range of air pressure.

[0003] High-pressure air from the aircraft's air power system is converted into low-pressure air with stable pressure and flow rate through a pressure reducing valve and then delivered to the cabin. Specifically, the gas enters the high-pressure chamber through the product inlet, then passes through the valve assembly and the lift valve core into the low-pressure chamber, and finally flows from the low-pressure chamber to the outlet.

[0004] Traditional structures are prone to structural deformation and sealing failure under continuous high pressure conditions of 45MPa and above, resulting in low reliability and short service life. Safety protection functions rely on external independent safety valves, which leads to a non-compact system structure, increased weight, and additional interfaces that increase potential leakage points. Existing structural forms have not been optimized for ultra-high pressure and high pressure-reduction ratio applications, leaving room for improvement in terms of size, weight, and performance.

[0005] The existing structural design of aircraft pressure reducing valves raises several questions: How can they cope with the extreme loads brought about by a working pressure of 45MPa and a withstand pressure of 67.5 MPa? Will the pressure regulating accuracy of traditional pressure reducing valves significantly decrease under continuous high-pressure environments? How can they meet the complex and demanding environmental requirements of aircraft? How can product materials meet ultra-high pressure strength requirements while achieving product lightweighting? Does the current distributed design scheme of "pressure reducing valve + external independent safety valve" lead to increased system weight and limited layout space? Does this inadvertently increase the overall leakage risk and the complexity of installation and maintenance? Summary of the Invention

[0006] Based on existing problems, this paper seeks to develop an air pressure reducing valve with overpressure protection, comprising a housing, a lifting valve core, a return spring, a valve assembly, a gasket, a diaphragm, a pressure adjusting nut, a pressure adjusting spring, a cover, a spring support, and a safety valve assembly. The housing has a stepped cylindrical cavity, with the inner diameter gradually increasing from bottom to top, representing a high-pressure cavity, a low-pressure cavity, and a pressure regulating cavity. An inlet and an outlet are respectively located on opposite sides of the housing perpendicular to the axis of the stepped cylindrical cavity, coaxially arranged. Inlet one is connected to the stepped cylindrical cavity via a channel, and an inlet two is located near the inlet end perpendicular to channel one. A safety interface is located on one side of the housing perpendicular to the axis of inlet one and the outlet, connecting to the safety valve assembly. The two inlets can connect to two air intake lines of the system.

[0007] The lifting valve core has a cross structure and is placed below the stepped columnar cavity. A return spring is sleeved on the lower part of the lifting valve core, and a conical surface is provided on the upper part to make a sealing contact with the valve assembly, forming a high-pressure cavity. The upper external thread of the valve assembly is sealed to the internal thread of the housing. The pad is placed inside the valve assembly with clearance fit. The bottom end of the pad contacts the top of the lifting valve core. A diaphragm is provided at its top end. The valve assembly, the lifting valve core and the diaphragm form a low-pressure cavity. A pressure regulating spring is provided above the diaphragm, and a spring support is provided between the diaphragm and the pressure regulating spring. The cover is fitted on the outside of the pressure regulating spring and the spring support. The bottom outer side of the cover is threaded to the top inner side of the housing. The top of the cover uses a pressure regulating nut and a pressure regulating screw to press the pressure regulating spring against the spring support, which cooperates with the diaphragm to form a pressure regulating cavity. The shell has a parallel stepped cylindrical cavity axis with a second channel and a third channel. One end of the second channel is connected to the low-pressure cavity and the other end is connected to the outlet. One end of the third channel is connected to the low-pressure cavity and the other end is connected to the safety interface.

[0008] Furthermore, the valve assembly includes a valve body, a valve gasket, and a clamping nut. The valve body has an I-shaped cavity structure. The valve gasket is placed on the valve body and clamped and fixed by the clamping nut engaging with the internal thread at the lower end of the valve body. Before assembly, the valve gasket undergoes high-temperature pretreatment, and is then clamped and fixed by the clamping nut threadedly connecting it to the valve. Furthermore, the cone angle of the conical surface on the lifting valve core is 60°, the conical surface is in sealing contact with the valve gasket, and the lifting valve core and the clamping nut are in clearance fit to form a throttling obstruction.

[0009] Furthermore, the valve pad is made of polyimide, and the valve body is made of precipitation-hardened stainless steel. The end face of the valve body that contacts the valve pad has two annular protrusions. The valve pad is pre-treated at high temperature before assembly with the valve body. The protruding structure is embedded in a plastic seal and secured with a screw plug to form an interference fit with the valve body, increasing the sealing margin. Before the valve pad in valve assembly one is pressed into the safety valve seat, a small amount of all-purpose adhesive is applied to its circumferential surface and bottom surface, and after static pressure for 24 hours, the edges are sealed.

[0010] Furthermore, the safety valve assembly includes valve assembly two, a center, a valve seat, a spring, a pressure relief nut, a safety nut, a cap, and a screw. The valve seat has a hollow structure, with its outer left end threaded to the inner side of the safety interface, and a sealing ring is provided between them in a sealing groove for a sealing connection. Valve assembly two, the center, the spring, and the pressure relief nut are placed sequentially from left to right within the valve seat cavity. Valve assembly two has a valve pad two at its left end, which makes sealing contact with the limiting protrusion on the inner left end of the valve seat. Valve assembly two is located on the right side... The valve assembly has a groove at one end, and the outer side of the valve assembly is in clearance fit with the inner side of the valve seat. The tip of the right end of the valve is placed in the groove, and the right end of the spring is sleeved on the outer side of the left end of the valve. The left end abuts against the inner end of the pressure relief nut sleeve. The outer thread of the pressure relief nut is connected to the inner thread of the valve seat. The left end of the safety nut abuts against the right end of the valve seat and is connected to the outer thread of the pressure relief nut. The cap is fixedly connected to the thread of the pressure relief nut by a screw. A washer and a spring washer are sleeved on the outer surface of the screw root. The right end of the pressure relief nut and its inner cavity have a pressure relief channel.

[0011] Furthermore, the stepped cylindrical cavity is provided with a support washer and an elastic retaining ring. The support washer and the elastic retaining ring are sleeved on the outer side of the lower end of the lifting valve core, with the support washer positioned below the elastic retaining ring.

[0012] Furthermore, the outer side of the bottom end of the lifting valve core is sealed to the housing, and a star-shaped sealing ring and a retaining ring are provided at intervals at the sealing connection.

[0013] Furthermore, the valve assembly is provided with a sealing groove at the outer side and the housing sealing connection, and a star-shaped sealing ring and a retaining ring are provided at intervals in the sealing groove.

[0014] Furthermore, two thrust washers are installed on the inner side of the top of the pressure regulating nut, and a needle roller bearing is installed between the two thrust washers to prevent the pressure regulating spring from twisting during the product pressure reduction adjustment process, thus preventing stress from being released and improving the stability of the product pressure reduction.

[0015] Furthermore, the lifting valve core is made of precipitation-hardened stainless steel and has a cavity with an opening at the lower end, a balanced structure that prevents inlet pressure fluctuations from affecting the product's pressure reduction value. The core function of the valve assembly is as a moving part and main seal, serving as the actuator for pressure regulation. Under the combined action of spring force and outlet feedback pressure, the valve moves axially within the housing. By controlling the flow rate of high-pressure air, it achieves throttling and pressure reduction of the inlet high pressure.

[0016] The valve gasket works in conjunction with the lift valve core to form the main sealing pair and the throttling orifice. It is a fixed precision component whose sealing surface fits tightly against the sealing cone surface of the lift valve core, ensuring zero leakage when closed. When the lift valve core moves downward to open, the tiny annular gap between the gasket and the lift valve core forms a controllable throttling channel, which is the key part for realizing the energy conversion (pressure reduction) of high-pressure air.

[0017] The core function of the clamping nut is to secure and pre-tighten the mechanism. By tightening the thread, it reliably presses and fixes the valve gasket within the designated seat hole of the valve body, preventing displacement or loosening under the impact of high-pressure airflow. Simultaneously, it ensures a static seal between the valve gasket and the valve body, making it a crucial structure for guaranteeing the stability of the main sealing pair's working reference.

[0018] The safety valve seat serves as the centering base and flow path for the safety valve. This component is fixed inside the valve seat, with one end providing a precise mounting and sealing surface for the safety valve's valve gasket, ensuring the concentricity of the safety valve's sealing pair. The other end is connected to the pressure relief channel; when the safety valve opens, overpressure gas is guided through this component to the relief port.

[0019] Under normal system pressure, the valve pad is pressed tightly against the valve seat limit by the spring force, forming an absolute seal and isolating the system from the outside. When the system pressure exceeds the safety set value, the gas pressure overcomes the spring force, pushing the valve pad away from the valve seat limit, forming a pressure relief channel, quickly releasing pressure, and achieving overpressure protection.

[0020] Gas enters the high-pressure chamber through the product inlet, then flows through the valve assembly and lift valve core into the low-pressure chamber, and finally flows from the low-pressure chamber to the outlet. When there is no gas consumption at the product outlet, the pressure in the low-pressure chamber gradually increases. Simultaneously, this pressure is transmitted to the pressure regulating spring via the diaphragm and spring support, causing the spring to compress. At the same time, the lift valve core and valve assembly gradually close under the force of the return spring. When the outlet pressure reaches the specified value, the valve assembly closes completely, preventing further air from entering the low-pressure chamber. When there is gas consumption at the product outlet, the pressure in the low-pressure chamber gradually decreases. The force transmitted to the pressure regulating spring via the diaphragm and spring support becomes unbalanced. The pressure regulating spring pushes the spring support and diaphragm to open the lift valve core and compress the return spring. At this point, the valve assembly gradually opens, allowing air to re-enter the low-pressure chamber, and the pressure in the low-pressure chamber gradually increases back to the specified value. Through this repeated action, the product outlet pressure is kept constant within a certain range, achieving the pressure reduction function.

[0021] When the pressure in the low-pressure chamber exceeds the specified value, the gas is discharged into the air through the safety valve assembly until the pressure drops to the specified closing pressure value of the safety valve.

[0022] The beneficial effects of this utility model are: 1. This utility model employs a multi-stage stepped design integrated with a flow equalization channel, specifically designed for 45MPa high-pressure applications. This avoids severe turbulence and impact caused by pressure reduction. This structural form ensures more gradual and uniform stress distribution on key pressure-bearing components such as the shell and lifting valve core, fundamentally overcoming the inherent defects of traditional structures that are prone to deformation and damage under ultra-high pressure, thus ensuring long service life and high reliability at an inlet pressure of 45MPa.

[0023] 2. The performance leap brought about by the application of new materials: The sealing surface of the valve core and valve assembly adopts a combination of precipitation-hardening stainless steel and polyimide. This material selection detail gives the sealing surface extremely high hardness and excellent wear resistance, enabling it to withstand long-term erosion from high-pressure air; at the same time, its inherent thermal stability and low coefficient of friction ensure sealing stability under alternating hot and cold conditions and constant-open operation, completely solving the problem of internal leakage.

[0024] 3. The smooth achievement of a high pressure reduction ratio is ensured by the sealing structure design at the valve core and valve assembly, which guarantees precise maintenance under high pressure differential, effectively controlling each pressure drop and energy conversion. This combination enables the present invention to achieve a pressure reduction ratio of up to 9:1 or even higher smoothly and with low noise, providing an extremely stable air source for downstream precision equipment and improving the operational quality of the entire cockpit canopy airtight system.

[0025] 4. By employing a star-shaped sealing ring + retaining ring structure, the star-shaped sealing ring, also known as an X-shaped sealing ring, is a sealing element that can provide sealing in two directions. Installed in various types of grooves, its radial or axial pre-compression gives the star-shaped sealing ring its initial sealing ability. Under air pressure, the cross-sectional shape of the star-shaped sealing ring ensures that the pressure is evenly transmitted in all directions, thus providing excellent high-pressure sealing performance. Its pre-compression is less than that of an O-ring, and its contact area is smaller. Less compression means less friction and wear, resulting in a longer service life. It can meet the requirements of high pressure (working pressure 45MPa, withstand pressure 67.5MPa), working temperature (-55℃~70℃), sealing performance (completely leak-free), and high reliability.

[0026] 5. The integrated design with a built-in safety valve eliminates the need for additional piping, flanges, and connection points required for external safety valves. This not only reduces system weight and saves valuable installation space, but more importantly, it fundamentally reduces potential leakage paths and improves the overall sealing reliability of the system. This safety valve is highly responsive and has a precise pressure setting. It can rapidly open and release pressure in the event of overpressure caused by main valve failure, providing an inherently safe overpressure protection barrier for the aircraft's air system and significantly enhancing flight safety.

[0027] 6. The unique effects of the combination: The combination of "new structure + lightweight materials + integrated design" brings about a unique effect that goes beyond the simple sum of individual advantages. The durability of components is greatly extended, and the integrated design reduces the number of parts, resulting in a significant reduction in the number of maintenance operations, spare parts inventory, and replacement time throughout the entire life cycle of this pressure reducing valve. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments conforming to the present invention and, together with the description, serve to explain the principles of the present invention. It is obvious that the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0029] Figure 1 A schematic diagram of the structure of the high-pressure air pressure reducing valve with overpressure protection provided by this utility model; Figure 2 for Figure 1 Schematic diagram of cross section in the middle AA direction; Figure 3 A schematic diagram of the shell structure provided for this utility model; Figure 4 for Figure 3 Schematic diagram of cross section in the middle BB direction; Figure 5 A schematic diagram of the lifting valve structure provided by this utility model; Figure 6 A schematic diagram of the structure of the valve assembly provided by this utility model; Figure 7 A schematic diagram of the valve body structure provided by this utility model; Figure 8 A schematic diagram of the safety valve assembly structure provided by this utility model; Figure 9 This is a schematic diagram of the second structure of the valve assembly provided by this utility model; Wherein: 1-shell, 101-stepped cylindrical cavity, 102-inlet one, 103-inlet two, 104-outlet, 105-safety interface, 101.1-high pressure cavity, 101.2-low pressure cavity, 101.3-pressure regulating cavity, 102.1-channel one, 104.1-channel two, 105.1-channel three. Support washer, 3-lift valve core, 301-conical surface, 302-cavity. 4-Return spring, 5-Valve assembly one, 501-Valve body, 502-Valve gasket one, 503-Pressure nut, 501.1-Protrusion, 6-Panicle block, 7-Diaphragm, 8-Adjusting nut, 9-Adjusting nut, 10-Adjusting spring, 11-Cap, 12-Spring support, 13-Star-shaped sealing ring II, 14-Retaining ring II, 15-Star-shaped sealing ring I, 16-Retaining ring I, 17-Safety valve assembly, 1701-Sealing ring, 1702-Valve assembly II, 1703-Top, 1704-Valve seat, 1705-Spring, 1706-Pressure relief nut, 1707-Safety nut, 1708-Cap, 1709-Washer, 1710-Spring washer, 1711-Screw, 1702.1-Valve pad II, 1702.2-Groove, 1704.1-Limiting protrusion, 1706.1-Pressure relief channel. 18-Elastic retaining ring, 19-Needle roller bearing, 20-Thrust washer. Detailed Implementation

[0030] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0031] Please see Figure 1-9 The figure shows a schematic diagram of the high-pressure air pressure reducing valve with overpressure protection provided by this utility model, including a housing 1, a lifting valve core 3, a return spring 4, a valve assembly 5, a pad 6, a diaphragm 7, a pressure adjusting nut 8, a pressure adjusting nut 9, a pressure adjusting spring 10, a cover 11, a spring support 12, and a safety valve assembly 17. The housing 1 has a stepped columnar cavity 101, with the inner diameter gradually increasing from bottom to top, namely a high-pressure cavity 101.1, a low-pressure cavity 101.2, and a pressure adjusting cavity 101.3. The housing 1 has an inlet 102 and an outlet 104 on both sides of the vertical stepped cylindrical cavity 101 axis. The inlet 102 and outlet 104 are coaxially arranged. The inlet 102 is connected to the stepped cylindrical cavity 101 through a channel 102.1. An inlet 2 103 is provided on the vertical channel 102.1 near the inlet 102 end. A safety interface 105 is provided on the side of the housing 1 perpendicular to the axis of the vertical inlet 102 and outlet 104, which is connected to the safety valve assembly 17. The lifting valve core 3 has a cross structure and is placed below the stepped columnar cavity 101. The lower part of the lifting valve core 3 is fitted with a return spring 4, and the upper part is provided with a conical surface 301 that is in sealing contact with the valve assembly 5 to form a high-pressure cavity 101.1. The upper external thread of the valve assembly 5 is sealed to the internal thread of the housing 1. The pad 6 is placed inside the valve assembly 5 with clearance fit. The bottom end of the pad 6 contacts the top of the lifting valve core 3. The top end of the pad 6 is provided with a diaphragm 7. The valve assembly 5, the lifting valve core 3 and the diaphragm 7 form a low-pressure cavity 101.2. A pressure regulating spring 10 is provided above the diaphragm 7, and a spring support 12 is provided between the diaphragm 7 and the pressure regulating spring 10. The cover 11 is sleeved on the outside of the pressure regulating spring 10 and the spring support 12. The bottom outer side of the cover 11 is threaded to the top inner side of the housing 1. The top of the cover 11 is engaged with the pressure regulating nut 8 and the pressure regulating nut 9 to press the pressure regulating spring 10 against the spring support 12, thus forming a pressure regulating cavity 101.3 with the diaphragm 7. like Figure 3-4 As shown, the housing 1 has a second channel 104.1 and a third channel 105.1 along the axis of the parallel stepped cylindrical cavity 101. One end of the second channel 104.1 is connected to the low-pressure cavity 101.2 and the other end is connected to the outlet 104. One end of the third channel 105.1 is connected to the low-pressure cavity 101.2 and the other end is connected to the safety interface 105.

[0032] like Figure 6 As shown, the valve assembly 5 includes a valve body 501, a valve pad 502, and a clamping nut 503. The valve body 501 has an I-shaped cavity structure. The valve pad 502 is placed on the valve body 501. The valve pad 502 is clamped and fixed by the clamping nut 503 engaging with the internal thread at the lower end of the valve body 501.

[0033] The cone angle α of the cone surface 301 on the lifting valve core 3 is 60°. The cone surface 301 is in sealing contact with the valve gasket 502, and the lifting valve core 3 is in clearance fit with the clamping nut 503.

[0034] The valve gasket 502 is made of polyimide, and the valve body 501 is made of precipitation-hardened stainless steel. The end face of the valve body 501 that contacts the valve gasket 502 has two annular protrusions 501.1. The valve gasket 502 undergoes high-temperature pretreatment before assembly with the valve body 501 to form an interference fit. The protrusions 501.1 are embedded in the polyimide valve gasket 502 and secured with a compression nut 503 to form an interference fit with the valve body 501, increasing the sealing margin.

[0035] like Figure 8-9As shown, the safety valve assembly 17 includes valve assembly two 1702, a top 1703, a valve seat 1704, a spring 1705, a pressure relief nut 1706, a safety nut 1707, a cap 1708, and a screw 1711. The valve seat 1704 has a hollow structure. The outer side of the left end of the valve seat 1704 is threaded to the inner side of the safety interface 105, and a sealing ring 1701 is provided between them and placed in a sealing groove for sealing connection. Valve assembly two 1702, the top 1703, the spring 1705, and the pressure relief nut 1706 are placed in the inner cavity of the valve seat 1704 in sequence from left to right. The left end of valve assembly two 1702 has a valve pad two 1702.1 that is in sealing contact with the inner limit protrusion 1704.1 on the left end of the valve seat 1704. The right end is provided with a groove 1702.2. The outer side of the valve assembly 1702 is in clearance fit with the inner side of the valve seat 1704. The right tip of the top 1703 is placed in the groove 1702.2. The right end of the spring 1705 is sleeved on the outer side of the left end of the top 1703. The left end abuts against the inner end of the pressure relief nut 1706. The outer thread of the pressure relief nut 1706 is connected to the inner thread of the valve seat 1704. The left end of the safety nut 1707 abuts against the right end of the valve seat 1704 and is connected to the outer thread of the pressure relief nut 1706. The cap 1708 is fixedly connected to the pressure relief nut 1706 by the screw 1711. The outer surface of the root of the screw 1711 is fitted with a washer 1709 and a spring washer 1710. The right end of the pressure relief nut 1706 and its inner cavity have a pressure relief channel 1706.1. Before pressing the valve gasket 2702.1 in valve assembly 2702 into the safety valve seat, a small amount of all-purpose adhesive is applied to its circumferential surface and bottom surface, and after static pressure for 24 hours, the joint is sealed. The integrated design of the built-in safety valve avoids the additional piping, flanges, and connection points required for external safety valves, not only reducing system weight and saving valuable installation space, but more importantly, fundamentally reducing potential leakage paths and improving the overall sealing reliability of the system. This safety valve is highly responsive and has a precise set pressure, capable of rapidly opening and releasing pressure in the instant of overpressure caused by main valve failure, providing an inherently safe overpressure protection barrier for the aircraft's air system and greatly improving flight safety.

[0036] The stepped cylindrical cavity 101 is provided with a support washer 2 and an elastic retaining ring 18. The support washer 2 and the elastic retaining ring 18 are sleeved on the outer side of the lower end of the lifting valve core 3, with the support washer 2 positioned below the elastic retaining ring 18.

[0037] The bottom outer side of the lifting valve core 3 is sealed to the housing 1, with a star-shaped sealing ring 15 and a retaining ring 16 spaced apart at the sealing connection. The valve assembly 5 has a sealing groove at its outer side where it is sealed to the housing 1, with a star-shaped sealing ring 13 and a retaining ring 14 spaced apart within the sealing groove. The star-shaped sealing ring, also known as an X-shaped sealing ring, is a sealing element that can seal in two directions. Installed in various types of grooves, its radial or axial pre-compression gives it initial sealing capability. Under air pressure, the cross-sectional shape of the star-shaped sealing ring ensures that the pressure is evenly transmitted in all directions, thus providing excellent high-pressure sealing. It has less pre-compression than an O-ring and a smaller contact area; less compression means less friction and wear, resulting in a longer service life. It can meet the requirements of high pressure (working pressure 45MPa, withstand pressure 67.5MPa), working temperature (-55℃~70℃), sealing performance (completely leak-free), and high reliability.

[0038] Two thrust washers 20 are installed on the inner side of the top of the pressure regulating nut 8, and a needle roller bearing 19 is installed between the two thrust washers 20.

[0039] like Figure 5 As shown, the lift valve core 3 is made of precipitation-hardened stainless steel and has a cavity 302 with an opening at the lower end. The sealing pair between the lift valve core 3 and the valve assembly 5 uses a combination of precipitation-hardened stainless steel and polyimide. This material selection gives the sealing surface extremely high hardness and excellent wear resistance, enabling it to withstand long-term erosion from high-pressure air; at the same time, its inherent thermal stability and low coefficient of friction ensure sealing stability under alternating hot and cold conditions and constant-open operating conditions, completely solving the internal leakage problem.

[0040] The core function of valve assembly 1 (5) and valve assembly 2 (1702) is to act as moving parts and main seals, serving as the actuators for pressure regulation. Under the combined action of spring force and outlet feedback pressure, the valve moves axially within the housing. By controlling the flow rate of high-pressure air, throttling and pressure reduction of the inlet high pressure are achieved.

[0041] The valve seat 502, in conjunction with the lift valve core 3, forms the main sealing pair and the throttling orifice. It is a fixed, precision component whose sealing surface tightly fits the sealing cone surface 301 of the lift valve core 3, ensuring zero leakage in the closed state. When the lift valve core 3 moves downwards to open, the tiny annular gap between the valve seat 502 and the lift valve core 3 forms a controllable throttling channel, a key component for achieving high-pressure air energy conversion (pressure reduction). The sealing structure design ensures precise maintenance under high pressure differentials, effectively controlling each pressure drop and energy conversion. This combination enables the present invention to achieve a pressure reduction ratio as high as 9:1 or even higher smoothly and with low noise, providing an extremely stable air source for downstream precision equipment and improving the overall operational quality of the cockpit canopy airtight system.

[0042] The core function of the clamping nut 503 is to fix and pre-tighten the mechanism. By tightening the thread, it reliably presses and fixes the valve gasket 502 into the designated seat hole of the valve body 501, preventing it from shifting or loosening under the impact of high-pressure airflow. At the same time, it ensures the static seal between the valve gasket 502 and the valve body 501, which is an important structure to ensure the stability of the working reference of the main sealing pair.

[0043] Valve assembly 1702 serves as the centering base and flow path for the safety valve. This component is fixed within the valve seat 1704. One end provides a precise mounting and sealing surface for the valve gasket 1702.1 of the safety valve, ensuring the concentricity of the safety valve's sealing surfaces. The other end is connected to the pressure relief channel 1706.1. When the safety valve opens, overpressure gas is guided through this component to the relief port.

[0044] Under normal system pressure, valve gasket 1702.1 is pressed tightly against the valve seat 1704 limit position by the spring force of spring 1705, forming an absolute seal with the limit protrusion 1704.1, isolating the system from the outside world. When the system pressure exceeds the safety set value, the gas pressure overcomes the spring force, pushing valve gasket 1702.1 out of the valve seat 1704 limit position, forming a pressure relief channel, quickly releasing pressure, and achieving overpressure protection.

[0045] Gas enters the high-pressure chamber 101.1 through the product inlet, then passes through valve assembly 5 and lift valve core 3 into the low-pressure chamber 101.2, and finally flows from the low-pressure chamber 101.2 to the outlet 104 via channel 104.1. When there is no gas consumption at the product outlet 104, the pressure in the low-pressure chamber 101.2 gradually increases. Simultaneously, this pressure is transmitted to the pressure regulating spring 10 via diaphragm 7 and spring support 12, causing the spring to compress. At the same time, the lift valve core 3 and valve assembly 5 gradually close under the force of the return spring 4. When the pressure in the outlet 104 reaches the specified value, valve assembly 5 completely closes, preventing further air entry into the low-pressure chamber 101.2. When there is gas consumption at the product outlet 104... Under these conditions, the pressure in the low-pressure chamber 101.2 of the product gradually decreases. The force transmitted to the pressure regulating spring 10 through the diaphragm 7 and spring support 12 becomes unbalanced. The force of the pressure regulating spring 10 pushes the spring support 12 and diaphragm 7 to open the lifting valve core 3 and compress the reset spring 4. At this time, the valve assembly 5 gradually opens, and air re-enters the low-pressure chamber 101.2 of the product. The pressure in the low-pressure chamber 101.2 gradually rises to the specified value. Through the above repeated actions, the product outlet 104 pressure is kept constant within a certain range, thus achieving the pressure reduction function.

[0046] When the pressure in the low-pressure chamber 101.2 exceeds the specified value, the gas is discharged into the air through the safety valve assembly 17 until the pressure drops to the specified closing pressure value of the safety valve.

[0047] This ultra-high pressure air pressure reducing valve is specifically designed for 45MPa high pressure. It employs a multi-stage stepped design with an integrated flow equalization channel, avoiding severe turbulence and impact caused by pressure reduction. This structural form ensures more gradual and uniform stress on key pressure-bearing components such as the shell and lift valve core, fundamentally overcoming the defects of traditional structures that are prone to deformation and damage under ultra-high pressure, ensuring long service life and high reliability at an inlet pressure of 45MPa. It exhibits excellent structural performance under continuous high pressure of 45MPa and various environmental conditions. The pressure reducing valve structure adopts a reverse unloading type air pressure reducing valve with a metal diaphragm pressure-sensing structure, featuring high pressure control accuracy. It also boasts a high pressure reduction ratio, capable of reducing compressed air from 45MPa (working pressure, withstand pressure 67.5MPa) to 5MPa. The sealing pair between the lift valve core and the valve assembly uses a combination of precipitation-hardened stainless steel and polyimide. This results in a sealing surface with extremely high hardness and excellent wear resistance, capable of withstanding long-term erosion from high-pressure air. Simultaneously, its inherent thermal stability and low coefficient of friction ensure sealing stability under alternating hot and cold conditions and continuous operation, completely resolving the internal leakage problem. The combination of this novel structure, lightweight materials, and integrated design delivers a unique effect that transcends the simple sum of individual advantages. The increased durability of components significantly extends maintenance cycles, while the integrated design reduces the number of parts, resulting in a substantial decrease in the number of maintenance visits, spare parts inventory, and replacement time throughout the pressure reducing valve's lifespan.

[0048] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, are all covered within the scope of the claims of this utility model.

Claims

1. A high-pressure air pressure reducing valve with overpressure protection, characterized in that: The system includes a housing (1), a lifting valve core (3), a return spring (4), a valve assembly (5), a pad (6), a diaphragm (7), a pressure adjusting nut (8), a pressure adjusting nut (9), a pressure adjusting spring (10), a cover (11), a spring support (12), and a safety valve assembly (17). The housing (1) has a stepped columnar cavity (101), with the inner diameter gradually increasing from bottom to top, namely a high-pressure cavity (101.1), a low-pressure cavity (101.2), and a pressure adjusting cavity (101.3). The housing (1) has an inlet (102) and an outlet (104) on both sides of the vertical stepped cylindrical cavity (101) axis. The inlet (102) and outlet (104) are coaxially arranged. The inlet (102) is connected to the stepped cylindrical cavity (101) through a channel (102.1). An inlet (103) is provided near the end of the inlet (102) perpendicular to the channel (102.1). A safety interface (105) is provided on one side of the housing (1) perpendicular to the axis of the inlet (102) and the outlet (104) and is connected to the safety valve assembly (17). The lifting valve core (3) has a cross structure and is placed below the stepped columnar cavity (101). The lower part of the lifting valve core (3) is fitted with a reset spring (4), and the upper part is provided with a conical surface (301) that is in sealing contact with the valve assembly (5) to form a high-pressure cavity (101.1). The upper external thread of the valve assembly (5) is sealed to the internal thread of the housing (1). The pad (6) is placed inside the valve assembly (5) with clearance fit. The bottom end of the pad (6) contacts the top of the lifting valve core (3). A diaphragm (7) is provided at its top end. The valve assembly (5), the lifting valve core (3) and the diaphragm (7) form a low-pressure cavity (101.2). A pressure regulating spring (10) is provided above the diaphragm (7), and a spring support (12) is provided between the diaphragm (7) and the pressure regulating spring (10). The cover (11) is sleeved on the outside of the pressure regulating spring (10) and the spring support (12). The bottom outer side of the cover (11) is threaded to the top inner side of the shell (1). The top of the cover (11) is fitted with a pressure regulating nut (8) and a pressure regulating screw (9) to press the pressure regulating spring (10) against the spring support (12), and cooperates with the diaphragm (7) to form a pressure regulating cavity (101.3). The shell (1) has a parallel stepped columnar cavity (101) with a channel two (104.1) and a channel three (105.1) along its axis. One end of the channel two (104.1) is connected to the low-pressure cavity (101.2), and the other end is connected to the outlet (104). One end of the channel three (105.1) is connected to the low-pressure cavity (101.2), and the other end is connected to the safety interface (105).

2. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: The valve assembly 1 (5) includes a valve body (501), a valve pad 1 (502), and a clamping nut (503). The valve body (501) has an I-shaped cavity structure. The valve pad 1 (502) is placed on the valve body (501). The valve pad 1 (502) is clamped and fixed by the clamping nut (503) engaging with the internal thread at the lower end of the valve body (501).

3. The high-pressure air pressure reducing valve with overpressure protection according to claim 2, characterized in that: The cone angle α of the cone surface (301) on the lifting valve core (3) is 60°. The cone surface (301) is in sealing contact with the valve gasket (502). The lifting valve core (3) is in clearance fit with the clamping nut (503).

4. The high-pressure air pressure reducing valve with overpressure protection according to claim 2, characterized in that: The valve pad (502) is made of polyimide material, and the valve body (501) is made of precipitation hardening stainless steel material. The end face of the valve body (501) that contacts the valve pad (502) is provided with two annular protrusions (501.1). The valve pad (502) and the valve body (501) are pre-treated at high temperature before assembly to form an interference fit with the valve body (501).

5. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: The safety valve assembly (17) includes valve assembly two (1702), a top (1703), a valve seat (1704), a spring (1705), a pressure relief nut (1706), a safety nut (1707), a cap (1708), and a screw (1711). The valve seat (1704) has a hollow structure. The outer left end of the valve seat (1704) is threaded to the inner side of the safety interface (105), and a seal is provided between them. The ring (1701) is placed in the sealing groove for sealing connection. The valve assembly two (1702), the top (1703), the spring (1705), and the pressure relief nut (1706) are placed in the inner cavity of the valve seat (1704) from left to right. The valve assembly two (1702) has a valve pad two (1702.1) on the left end, which is in sealing contact with the limiting protrusion (1704.1) on the inner side of the left end of the valve seat (1704). The valve assembly two (1702) The right end has a groove (1702.2). The outer side of the valve assembly two (1702) is clearance-fitted with the inner side of the valve seat (1704). The right tip of the center point (1703) is placed in the groove (1702.2). The right end of the spring (1705) is sleeved on the outer side of the left end of the center point (1703), and the left end abuts against the inner end of the pressure relief nut (1706). The outer thread of the pressure relief nut (1706) is connected to the inner thread of the valve seat (1704), ensuring... The left end of the safety nut (1707) abuts against the right end of the valve seat (1704) and is threadedly connected to the outside of the pressure relief nut (1706). The cap (1708) is threadedly fixed to the pressure relief nut (1706) by a screw (1711). A washer (1709) and a spring washer (1710) are fitted on the outer surface of the root of the screw (1711). The right end of the pressure relief nut (1706) and its inner cavity have a pressure relief channel (1706.1).

6. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: The stepped cylindrical cavity (101) is provided with a support washer (2) and an elastic retaining ring (18). The support washer (2) and the elastic retaining ring (18) are sleeved on the outer side of the lower end of the lifting valve core (3), and the support washer (2) is placed below the elastic retaining ring (18).

7. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: The bottom outer side of the lifting valve core (3) is sealed to the housing (1), and a star-shaped sealing ring (15) and a retaining ring (16) are provided at intervals at the sealing connection.

8. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: The valve assembly (5) is provided with a sealing groove at the sealing connection between the outer side and the housing (1), and a star-shaped sealing ring (13) and a retaining ring (14) are provided at intervals in the sealing groove.

9. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: Two thrust washers (20) are installed on the inner side of the top of the pressure regulating nut (8), and a needle roller bearing (19) is installed between the two thrust washers (20).

10. The high-pressure air pressure reducing valve with overpressure protection according to claim 1, characterized in that: The lifting valve core (3) is made of precipitation hardened stainless steel and has a cavity (302) with an opening at the lower end.

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