An electrically driven direct-acting high-pressure pneumatic pressure reducing valve and its optimized design method

Abstract

The present invention belongs to the technical field related to air pressure control and discloses an electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve and its optimized design method. The pressure reducing valve includes a main valve assembly and a relief valve, wherein the relief valve is embedded in the main valve assembly. The relief valve is used to automatically open and exhaust air when the pressure reducing valve needs to release pressure or when the outlet pressure exceeds a set pressure, thereby completing pressure release or stabilizing the outlet pressure at the set pressure. The driving force of the relief valve is the difference between the compressed air pressure at the opposite ends of the main valve piston of the main valve assembly and the motor driving force. Through structural improvements, the present invention achieves rapid response, high pressure regulation accuracy, and a compact structure.

Description

Technical Field

[0001] The present invention belongs to the technical field related to pneumatic pressure control elements, and more specifically, relates to an electrically driven direct-acting high-pressure pneumatic pressure reducing valve and an optimized design method thereof. Background Art

[0002] Pneumatic technology uses compressed air as the working medium and has the advantages of clean energy, pollution-free, low cost, easy operation, and fast response. It is widely used in various fields of modern industry.

[0003] In this field, pneumatic systems with pressures below 1MPa are called low-pressure pneumatic systems, those with pressures between 1MPa and 10MPa are called medium-pressure pneumatic systems, and those with pressures above 10MPa are called high-pressure pneumatic systems. Compared to low-pressure pneumatic technology, high-pressure pneumatic technology facilitates the miniaturization of component structures and the speed of actuators. Therefore, it has become a research hotspot in the field of fluid transmission and control.

[0004] As a critical control component in pneumatic systems, the performance of the pressure reducing valve (PRV) determines the safe and stable operation of the entire system. An ideal PRV maintains a constant downstream pressure at the set value regardless of downstream pressure fluctuations. However, in high-pressure pneumatic systems, pressure fluctuations downstream of the PRV and leakage from the PRV itself pose a serious safety threat to downstream equipment. Furthermore, most existing PRVs require a separate on / off valve for gas discharge. Summary of the Invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides an electrically driven direct-acting high-pressure pneumatic pressure reducing valve and an optimized design method thereof, which can respond quickly, have high pressure regulation accuracy and a compact structure through structural improvements.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an electrically driven direct-acting high-pressure pneumatic pressure reducing valve, wherein the pressure reducing valve comprises a main valve assembly and a relief valve, wherein the relief valve is embedded in the main valve assembly; the relief valve is used to automatically open and exhaust when the pressure reducing valve needs to release pressure or the outlet pressure exceeds the set pressure, so as to complete the pressure release or stabilize the outlet pressure at the set pressure, and the driving force of the relief valve is the difference between the pressure of the compressed air at the two opposite ends of the main valve piston of the main valve assembly and the force of the pressure regulating spring.

[0007] Furthermore, the main valve assembly includes a DC motor, a main valve upper end cover, a main valve body and a main valve lower end cover connected in sequence. The main valve assembly also includes a main valve piston, and a main valve pressure-regulating screw, a main valve pressure-regulating nut and a main valve pressure-regulating spring arranged in the main valve upper end cover. One end of the main valve pressure-regulating screw is connected to the rotating shaft of the DC motor, and the other end passes through the main valve pressure-regulating nut and enters the main valve pressure-regulating spring. The opposite ends of the main valve pressure-regulating spring respectively abut against the main valve pressure-regulating nut and the main valve piston. The main valve piston is arranged in the main valve body.

[0008] Furthermore, the main valve body is a stepped cylinder, and an air inlet cavity and an exhaust cavity are provided on the stepped portion thereof, and the air inlet cavity and the exhaust cavity are both arranged along the radial direction of the main valve body; the stepped portion of the main valve body is also provided with a first pressure gauge interface and a second pressure gauge interface, the second pressure gauge interface is located between the exhaust cavity and the first pressure gauge interface, and the first pressure gauge interface and the second pressure gauge interface are located between the air inlet cavity and the exhaust cavity; the two opposite ends of the main valve body are respectively provided with a first groove and a first threaded hole, the bottom surface of the first groove is provided with a second threaded hole, the bottom surface of the second threaded hole is provided with a second groove, the bottom surface of the second groove is provided with a third groove, and the bottom surface of the third groove is provided with a first Connecting hole, the first connecting hole passes through the bottom surface of the first threaded hole; the first pressure gauge interface and the air inlet chamber are respectively connected with the first connecting hole; a feedback hole is provided on the bottom surface of the second groove, and the feedback hole is connected with the exhaust chamber; a first receiving hole is provided on the bottom surface of the second groove; a first vertical channel is provided on the bottom surface of the third groove, and the first vertical channel is connected with the second pressure gauge interface; one end of the lower end cover of the main valve extends into the first groove, the second threaded hole and the second groove, and forms a threaded connection with the second threaded hole, and the steps formed on the outer periphery of the lower end cover of the main valve respectively abut against the bottom surface of the first groove, the bottom surface of the second threaded hole and the bottom surface of the second groove.

[0009] Furthermore, the lower end cover of the main valve is stepped, and a stepped groove is provided at one end thereof; one end of the lower end cover of the main valve is threadedly connected to the first threaded hole; the main valve assembly also includes a main valve core, and the end of the main valve core used for contacting the overflow valve is conical, and includes a main valve core body, a main valve core sealing ring and a main valve core screw; the main valve core body is a cylinder, and a second boss is provided on the outer periphery of one end thereof, and the second boss is annular; a ninth groove is provided at one end of the main valve core body adjacent to the second boss, and a first stepped hole is provided on the bottom surface of the ninth groove, and the first stepped hole passes through the main valve core body; the main valve core sealing ring portion is arranged in the ninth groove, and one end of the main valve core screw passes through the main valve core sealing ring and is threadedly connected to the first stepped hole.

[0010] Furthermore, one end of the main valve core body passes through the main valve core return spring, the hole retaining spring, the metal ring and the plastic ring in sequence and enters the stepped groove, and the main valve core body is located in the main valve body; the main valve core body and the bottom surface of the stepped groove are spaced apart to form a balance chamber; the two ends of the main valve core return spring respectively rest on the second boss and the hole retaining spring; the main valve assembly also includes a main valve seat and a partition, the main valve seat is stepped, and is provided with a fifth through hole, the fifth through hole is used to accommodate part of the main valve core push rod and the main Valve core; one end of the main valve seat is threadedly connected to the first connecting hole, and the step at the other end abuts against the bottom surface of the third groove; the main valve seat is accommodated in the first connecting hole and the third groove; the partition is arranged on the bottom surface of the second groove; the main valve piston sleeve is arranged in the second groove and the third groove, and one end thereof abuts against the partition, and the other end abuts against the upper end cover of the main valve; a buffer chamber is formed between the partition and the bottom surface of the third groove; a pressure feedback chamber is formed between the main valve piston and the partition.

[0011] Furthermore, the relief valve includes a relief valve adjusting spring, a relief valve adjusting screw, a relief valve push rod, a relief valve end cover, a relief valve sealing ring, a relief valve core, a relief valve spring and a relief valve body; the relief valve body is stepped, and a sixth groove is provided in the axial direction, and a second countersunk hole is provided on the bottom surface of the sixth groove; a third connecting hole is also provided on the step portion of the relief valve body, and the third connecting hole connects the second countersunk hole with the pressure feedback chamber; the step portion of the relief valve body is provided at the The main valve piston is in the fourth groove at one end away from the DC motor, and its end away from the step portion passes through the locking nut and extends into the overflow valve end cover; the overflow valve sealing ring is arranged in the sixth groove; the overflow valve spool is arranged in the second countersunk hole; one end of the overflow valve spring abuts against the bottom of the second countersunk hole, and the other end is connected to one end of the overflow valve spool, and the other end of the overflow valve spool is conical and connected to the overflow valve sealing ring; the overflow valve spool is provided with a through hole.

[0012] Furthermore, the overflow valve end cover is partially located in the main valve pressure regulating spring, a seventh groove is provided at one end of the overflow valve end cover, and the end of the overflow valve body with the sixth groove is arranged in the seventh groove; an eighth groove is provided at the other end of the overflow valve cover, and a fourth connecting hole is provided on the bottom surface of the second groove, and the fourth connecting hole passes through the bottom surface of the seventh groove and is connected with the through hole; the overflow valve end cover is also provided with a radially arranged fourth through hole, and the fourth through hole passes through the eighth groove and at the same time passes through the overflow valve end cover, and is connected with the fifth groove opened at the other end of the main valve piston.

[0013] Furthermore, one end of the relief valve push rod is arranged in the eighth groove, and the other end is arranged in the third through hole of the main valve pressure regulating screw; one end of the relief valve adjusting screw is arranged in a first countersunk hole opened in the main valve pressure regulating screw and connected to the third through hole, and the other end passes through the relief valve adjusting spring and abuts against the relief valve push rod; the pressure reducing valve also includes a pressure sensor and a controller, the pressure sensor is arranged in the outlet pipe of the pressure reducing valve, and is used to detect the pressure of the outlet and transmit the detected outlet pressure value to the controller; the controller outputs a control instruction to the DC motor based on the pressure value received from the pressure sensor, so as to control the DC motor, and then adjust the outlet pressure to the target value.

[0014] The present invention also provides an optimization design method for an electrically driven direct-acting high-pressure pneumatic pressure reducing valve, the method comprising the following steps:

[0015] Step 1: Building a simulation model of the pressure reducing valve based on the structural principle of the pressure reducing valve as described above;

[0016] Step 2: Determine the optimization goal and formulate the pressure characteristic, flow characteristic and dynamic characteristic evaluation function, confirm the value range of the design parameters based on the model, and then generate the sample space;

[0017] Step 3, using the simulation model to calculate the function values ​​of the pressure characteristics, flow characteristics and dynamic characteristics evaluation function of the pressure reducing valve in the electronically controlled regulation state for each group of samples in the sample space;

[0018] Step 4: The response surface of each design parameter is fitted by the genetic aggregation method for the calculated results, and then the multi-objective genetic algorithm is used to optimize the obtained response surface to determine the optimal design parameters.

[0019] Furthermore, in step one, first, a model of the pressure reducing valve is constructed, and according to the gas flow principle and pressure distribution law in the flow channel of the pressure reducing valve, the gas path in the flow channel of the model of the pressure reducing valve is simplified into a pneumatic bridge shape in which four cavities are connected to five throttle ports, and is expressed as a dynamic pneumatic bridge; then, based on the gas flow principle of each cavity, a simulation model of the pressure reducing valve is established according to the mass flow equation, the gas state equation, and Newton's second law.

[0020] In general, compared with the prior art, the above technical solutions conceived by the present invention provide an electrically driven direct-acting high-pressure pneumatic pressure reducing valve and an optimized design method thereof, which have the following beneficial effects:

[0021] 1. A relief valve is separately provided in the main valve of the present invention. When the pressure needs to be released or the outlet pressure is higher than the set pressure, the relief valve opens and exhausts the air, ensuring stable and rapid pressure adjustment, and ensuring the safety and stability of the work, reducing the structural volume and improving the structural compactness.

[0022] 2. A DC motor is used to control the pressure regulation of the electric-driven direct-acting high-pressure pneumatic pressure reducing valve to achieve closed-loop regulation of the outlet pressure and maintain the stability of the outlet pressure within a certain range during operation. It has the characteristics of small weight and volume but large flow, stable outlet pressure, high pressure regulation accuracy, good air tightness, and sensitive operation. It has good pressure characteristics, flow characteristics and dynamic adjustment performance, and has manual adjustment capabilities in the power-off state.

[0023] 3. The main valve core sealing ring and the relief valve sealing ring adopt a specific structure to ensure the overall air tightness of the piston type high pressure pneumatic pressure reducing valve.

[0024] 4. The use of high-rigidity main valve pressure-regulating spring and a piston with a large pressure area improves the sensitivity of the piston-type high-pressure pneumatic pressure reducing valve; the structural design of the main valve core makes the resultant force of the air pressure acting on the main valve core zero, ensuring the stability of the outlet pressure.

[0025] 5. The pressure regulating nut is composed of a threaded sleeve and a pressure regulating nut body. The pressure regulating nut body is made of metal material to ensure the strength of the main valve pressure regulating nut. The threaded sleeve and the main valve pressure regulating screw are made of different materials to reduce the friction between the two and reduce the torque during pressure regulation.

[0026] 6. The main valve piston sleeve and the main valve seat are embedded in the main valve body, which reduces the processing difficulty and cost of the main valve body, facilitates maintenance and replacement, and extends the service life.

[0027] 7. By setting the flow channel and cavity in the main valve body, the electric drive direct-acting high-pressure pneumatic pressure reducing valve provided by the present invention has a compact overall structure, small volume and weight, but large flow rate.

[0028] 8. Through the dynamic pneumatic bridge analysis method, the internal flow path structure of the electrically driven direct-acting high-pressure pneumatic pressure reducing valve is represented as a dynamic pneumatic bridge diagram, which is convenient for building a simulation model to analyze the pressure characteristics, flow characteristics and dynamic characteristics of the pressure reducing valve.

[0029] 9. Through structural optimization design, the electrically driven direct-acting high-pressure pneumatic pressure reducing valve provided by the present invention has good pressure characteristics, flow characteristics and dynamic characteristics under the electrically controlled adjustment state. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of an electrically driven direct-acting high-pressure pneumatic pressure reducing valve provided by the present invention;

[0031] Figure 2a yes Figure 1 Schematic diagram of the main valve body of the electric drive direct-acting high-pressure pneumatic pressure reducing valve; Figure 2b yes Figure 2a A cross-sectional view of the main valve body along the AA direction; Figure 2c for Figure 2b A cross-sectional view of the main valve body along the BB direction;

[0032] Figure 3 yes Figure 1 A schematic diagram of the structure of the main valve pressure regulating nut of the electrically driven direct-acting high-pressure pneumatic pressure reducing valve;

[0033] Figure 4 yes Figure 1 A schematic diagram of the structure of the relief valve of the electrically driven direct-acting high-pressure pneumatic pressure reducing valve;

[0034] Figure 5 yes Figure 1 Schematic diagram of the structure of the main valve core of the electric drive direct-acting high-pressure pneumatic pressure reducing valve;

[0035] Figure 6 yes Figure 1 Working diagram of the electric drive direct-acting high-pressure pneumatic pressure reducing valve;

[0036] Figure 7 yes Figure 1 Schematic diagram of the principle of the electric drive direct-acting high-pressure pneumatic pressure reducing valve;

[0037] Figure 8 yes Figure 1 Schematic diagram of the control principle of the electric drive direct-acting high-pressure pneumatic pressure reducing valve;

[0038] Figure 9 yes Figure 1 Flowchart of the optimized design of the electric-driven direct-acting high-pressure pneumatic pressure reducing valve.

[0039] In all the drawings, the same reference numerals are used to represent the same elements or structures, among which: 1-rotating shaft, 2-DC motor, 3-main valve pressure regulating screw, 4-relief valve regulating spring, 5-relief valve regulating screw, 6-thrust bearing, 7-main valve upper end cover, 8-main valve pressure regulating nut, 9-main valve pressure regulating spring, 10-thin nut, 11-locking nut, 12-main valve piston, 13-first sealing ring, 14-main valve piston sleeve, 15-second sealing ring, 16-third sealing ring, 17-partition, 18-elastic cylindrical pin, 19-fourth sealing ring, 20-main valve seat, 21-main valve core screw, 22-main valve core Sealing ring, 23-main valve core, 24-main valve core return spring, 25-sixth sealing ring, 26-plastic ring, 27-main valve lower end cover, 28-fifth sealing ring, 29-main valve body, 30-metal ring, 31-circlip for hole, 32-main valve core push rod, 33-feedback hole, 34-relief valve body, 35-relief valve spring, 36-relief valve core, 37-relief valve sealing ring, 38-relief valve end cover, 39-relief valve push rod, 40-limit screw, 41-flat washer, 42-spring washer, 43-hexagon socket bolt, 44-pressure regulating nut body, 45-sleeve, 46-pressure sensor, 47-controller. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0041] The present invention provides an electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve, the maximum input pressure of which reaches 40 MPa, and the output pressure is continuously adjustable within the range of 0 to 25 MPa; a DC motor 2 is provided on the electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve, and the DC motor 2 is used to directly drive the pressure reducing valve to adjust the output pressure. The pressure sensor 46 feeds back the output pressure to the controller 47 to achieve closed-loop control of the output pressure, thereby improving the control accuracy, response speed and stability of the output pressure, and at the same time having the function of manual adjustment, thereby facilitating the maintenance and replacement of the DC motor 2.

[0042] When using a pressure reducing valve, the output pressure must be adjusted according to the operating conditions. Electric-driven, direct-acting, high-pressure pneumatic pressure reducing valves automatically adjust the output pressure according to set parameters, reducing manual workload. They offer fast response, rapid adjustment, and stable output pressure, making them highly valuable. Furthermore, under motor control, the outlet pressure and flow rate of electric-driven, direct-acting, high-pressure pneumatic pressure reducing valves can be adjusted in real time, resulting in improved pressure and flow characteristics.

[0043] See also Figure 1 and Figure 6 The present invention provides an electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve comprising a main valve assembly and a relief valve, the relief valve being embedded within the main valve assembly. The relief valve automatically opens and vents when the pressure relief valve needs to release pressure or when the outlet pressure exceeds a set pressure, thereby releasing pressure or stabilizing the outlet pressure at the set pressure. The driving force of the relief valve is the difference between the compressed air pressure at the opposing ends of the main valve piston 12 of the main valve assembly and the force of the pressure-regulating spring.

[0044] The main valve assembly includes a DC motor 2, a main valve pressure regulating screw 3, a thrust bearing 6, a main valve upper end cover 7, a main valve pressure regulating nut 8, a main valve pressure regulating spring 9, a thin nut 10, a locking nut 11, a main valve piston 12, a first sealing ring 13, a main valve piston sleeve 14, a second sealing ring 15, a third sealing ring 16, a partition 17, a spring cylindrical pin, a fourth sealing ring 19, a main valve seat 20, a main valve core screw 21, a main valve core sealing ring 22, a main valve core 23, a main valve core return spring 24, a hexagon socket bolt 43, a spring washer 42, a flat washer 41, a limit screw 40, a main valve core push rod 32, a hole retaining ring 31, a metal ring 30, a main valve body 29, a fifth sealing ring 28, a main valve lower end cover 27, a plastic ring 26 and a sixth sealing ring 25.

[0045] One end of the hexagon socket bolt 43 passes through the spring washer 42, the flat washer 41, and the step of the DC motor 2, and then enters the main valve upper end cover 7, so that the DC motor is threadedly connected to the main valve upper end cover 7. One end of the DC motor's rotating shaft 1 is connected to one end of the main valve pressure regulating screw 3, and the other end protrudes from the main body of the DC motor, thus providing the pressure reducing valve with manual adjustment capabilities.

[0046] The main valve upper end cover 7 is stepped, and its other end is threadedly connected to one end of the main valve body 29. The end surface of the main valve upper end cover 7 abuts against the main valve piston sleeve 14. The main valve lower end cover 27 is threadedly connected to the other end of the main valve body 29.

[0047] The large end of the main valve upper end cover 7 is provided with a stepped first receiving groove, and the other end is provided with a second receiving groove. The bottom surface of the first receiving groove is provided with a connecting hole, and the connecting hole also passes through the bottom surface of the second receiving groove. The groove wall of the second receiving groove is provided with a long groove, and the long groove is used to accommodate the limit screw 40, which is arranged along the axial direction of the second receiving groove. The first receiving groove is used to accommodate part of the DC motor. One end of the main valve pressure regulating screw 3 is arranged in the first receiving groove, and the other end passes through the connecting hole and enters the second receiving groove. The thrust bearing 6 is arranged between the main valve pressure regulating screw 3 and the upper end of the main valve and is located on the bottom surface of the second receiving groove, so that the friction between the main valve pressure regulating screw and the main valve upper end cover can be reduced during pressure regulation.

[0048] See also Figure 4 The main valve pressure-regulating screw has a stepped shape and a first annular boss disposed on its outer circumference. This first boss is used to support the thrust bearing 6, which is located between the first boss and the bottom surface of the second receiving groove. A first counterbore is defined at one end of the main valve pressure-regulating screw adjacent to the first boss. A third through-hole is defined at the bottom of the first counterbore, with the central axis of the third through-hole coinciding with the central axis of the first counterbore.

[0049] See also Figure 3 The main valve pressure-regulating nut 8 is mounted on the main valve pressure-regulating screw and is located within the second receiving groove. The main valve pressure-regulating nut 8 is stepped and includes a pressure-regulating nut body 44 and a threaded sleeve 45. A third threaded hole is radially defined at one end of the pressure-regulating nut body 44. The pressure-regulating nut body 44 also defines a first through-hole. The threaded sleeve 45, mounted within the first through-hole, also defines a second through-hole for accommodating a portion of the main valve pressure-regulating screw.

[0050] In this embodiment, the main valve pressure regulating nut 8 is threadedly mounted on the main valve pressure regulating screw via the threaded sleeve 45. One end of the limit screw 40 is received in the elongated slot, and the other end is threadedly engaged with the third threaded hole, so that the main valve pressure regulating nut can only move along the axial direction of the main valve pressure regulating screw.

[0051] Two thin nuts 10 are further provided at one end of the main valve pressure regulating screw away from the main valve pressure regulating nut. The two thin nuts are locked with each other to limit the maximum displacement of the main valve pressure regulating nut.

[0052] In this embodiment, the screw sleeve and the pressure-regulating nut body are fixed together via a threaded connection and glue to form a single unit. The screw sleeve is made of plastic, while the main valve pressure-regulating screw is made of metal, which reduces friction between the threads. The pressure-regulating nut body is also made of metal, ensuring its strength.

[0053] See also Figure 2a 、 Figure 2b and Figure 2c The main valve body is a stepped cylindrical body, with an air intake cavity and an air exhaust cavity defined in the stepped portion. Both the air intake cavity and the air exhaust cavity are radially arranged along the main valve body. The stepped portion of the main valve body also defines a first pressure gauge port and a second pressure gauge port. The second pressure gauge port is located between the air exhaust cavity and the first pressure gauge port, while the first and second pressure gauge ports are located between the air intake cavity and the air exhaust cavity.

[0054] The main valve body has a first groove and a first threaded hole at opposite ends, respectively. The bottom of the first groove has a second threaded hole, the bottom of the second threaded hole has a second groove, and the bottom of the second groove has a third groove. The bottom of the third groove has a first connection hole, which extends through the bottom of the first threaded hole. The first pressure gauge port and the intake chamber are respectively connected to the first connection hole. The bottom of the second groove has a feedback hole 33, which is connected to the exhaust chamber. The bottom of the second groove has a first receiving hole, the central axis of which is parallel to the central axis of the third groove. The bottom of the third groove has a first vertical passage, which is connected to the second pressure gauge port. One end of the main valve lower end cap extends into the first groove, the second threaded hole, and the second groove, and is threadedly connected to the second threaded hole. Steps formed on the outer circumference of the main valve lower end cap abut against the bottoms of the first groove, the second threaded hole, and the second groove, respectively.

[0055] The main valve lower end cover is stepped, with a stepped groove formed at one end. A retaining ring groove is formed on the wall of the stepped groove. One end of the main valve lower end cover is threadedly connected to the first threaded hole.

[0056] See also Figure 5The main valve core, whose end contacts the relief valve, is tapered and comprises a main valve core body, a main valve core sealing ring 22, and a main valve core screw 21. The main valve core body is cylindrical, with a second annular boss disposed on the outer periphery of one end. A ninth groove is defined at one end of the main valve core body, adjacent to the second boss. The bottom surface of the ninth groove defines a first stepped hole, which extends through the main valve core body. The main valve core sealing ring 22 is partially disposed within the ninth groove. One end of the main valve core screw 21 passes through the main valve core sealing ring and is threadedly connected to the first stepped hole, thereby connecting the main valve core sealing ring to the main valve core body.

[0057] One end of the main valve core body passes through the main valve core return spring 24, the hole retaining spring 31, the metal ring 30, and the plastic ring 26 in sequence before entering the stepped groove. The main valve core body is located within the main valve body. The main valve core body is spaced apart from the bottom surface of the stepped groove to form a balancing chamber. The hole retaining spring is positioned within the retaining spring groove to limit the axial movement of the metal ring 30, the second sealing ring 15, and the plastic ring. The two ends of the main valve core return spring 24 rest against the second boss and the hole retaining spring, respectively. The plastic ring tightly fits the outer wall of the main valve core, providing a guide.

[0058] A sixth sealing ring 25 is provided between the main valve lower end cover and the main valve body to achieve sealing between the outer wall of the main valve lower end cover and the inner wall of the main valve body. A fifth sealing ring 28 is provided between the main valve core body and the groove wall of the stepped groove.

[0059] The main valve seat 20 is stepped and defines a fifth through-hole for accommodating a portion of the main valve core push rod 32 and the main valve core. One end of the main valve seat is threadedly connected to the first connecting hole, while a step at the other end abuts the bottom surface of the third groove. The main valve seat is accommodated in the first connecting hole and the third groove.

[0060] The partition plate 17 is positioned on the bottom surface of the second groove. One end of the elastic cylindrical pin 18 passes through the partition plate and enters the first receiving hole, thereby positioning the partition plate within the second groove. The main valve piston sleeve 14 is positioned within the second and third grooves, with one end resting on the partition plate and the other end resting on the main valve upper end cover. A second sealing ring is positioned between the main valve piston sleeve 14 and the wall of the second groove. A buffer chamber is formed between the partition plate and the bottom surface of the third groove.

[0061] The main valve piston portion is sleeved within the main valve piston sleeve and has a stepped shape. A pressure feedback chamber is formed between the main valve piston and the partition. The stepped portion of the main valve piston is arranged opposite to the step formed on the inner wall of the main valve piston sleeve, and the inner diameter of the step formed by the main valve piston corresponds to the inner diameter of the small end of the main valve piston, so that the main valve piston sleeve can limit the axial movement of the main valve piston. A first sealing ring 13 is provided between the main valve piston and the main valve piston sleeve.

[0062] The main valve piston has four and five grooves formed at opposite ends, respectively. The bottom of the fourth groove has a second connecting hole, which extends through the bottom of the fifth groove. The fourth and fifth grooves accommodate a portion of the relief valve. One end of the main valve core push rod 32 extends into the fifth through hole, abutting the main valve core, while the other end abuts the relief valve portion housed within the main valve piston. One end of the main valve pressure regulating spring 9 is inserted into the main valve pressure regulating nut, while the other end abuts the main valve piston.

[0063] See also Figure 4 The relief valve includes a relief valve adjustment spring 4, a relief valve adjustment screw 5, a relief valve push rod 39, a relief valve end cap 38, a relief valve seal 37, a relief valve core 36, a relief valve spring 35, and a relief valve body 34. The relief valve body 34 is stepped and defines a sixth groove along its axial direction. A second counterbore is defined at the bottom of the sixth groove. A third connecting hole is defined in the stepped portion of the relief valve body 34, connecting the second counterbore with the pressure feedback chamber. The stepped portion of the relief valve body 34 is positioned within the fourth groove, with a third sealing ring 16 disposed between the stepped portion and the bottom of the fourth groove. The end of the third sealing ring, distal from the stepped portion, passes through the lock nut 11 and extends into the relief valve end cap 38. The lock nut 11 is positioned within the fifth groove and forms a threaded connection with the relief valve body 34.

[0064] The relief valve seal ring 37 is disposed within the sixth groove. The relief valve spool 36 is disposed within the second counterbore. One end of the relief valve spring 35 abuts the bottom of the second counterbore, and the other end is connected to one end of the relief valve spool. The other end of the relief valve spool is tapered and connected to the relief valve seal ring 37. The relief valve spool has a through hole, the central axis of which coincides with the central axis of the relief valve seal ring.

[0065] The relief valve end cover is located within the main valve pressure regulating spring 9 and is cylindrical in shape. A seventh groove is defined at one end of the relief valve end cover, and the end of the relief valve body 34 defining the sixth groove is disposed within the seventh groove. An eighth groove is defined at the other end of the relief valve cover, and a fourth connecting hole is defined in the bottom surface of the second groove. The fourth connecting hole extends through the bottom surface of the seventh groove and communicates with the through hole. The relief valve end cover also defines a fourth radially disposed through-hole, which extends through the eighth groove and the relief valve end cover, communicating with the fifth groove.

[0066] One end of the relief valve push rod 39 is disposed in the eighth groove, and the other end is disposed in the third through hole. One end of the relief valve adjusting screw 5 is disposed in the first countersunk hole, and the other end passes through the relief valve adjusting spring 4 and abuts against the relief valve push rod 39.

[0067] In this embodiment, the lower end surface of the relief valve sealing ring is a spherical surface, and is in line contact with the edge of the inner wall step of the relief valve body; the relief valve push rod is a smooth rod; by adjusting the relief valve adjusting screw, the position of the relief valve push rod can be changed to adjust the sensitivity of the relief valve; when the pressure reducing valve is closed, the conical surface of the upper end of the main valve core sealing ring forms a line contact with the lower end edge of the hole of the main valve seat, thereby playing a sealing role.

[0068] The pressure reducing valve further includes a pressure sensor 46 and a controller 47. The pressure sensor 46 is disposed in the outlet pipe of the pressure reducing valve and is configured to detect the outlet pressure and transmit the detected outlet pressure value to the controller 47. Based on the pressure value received from the pressure sensor 46, the controller 47 outputs a control instruction to the DC motor to control the DC motor and thereby adjust the outlet pressure to a target value.

[0069] See also Figure 7 and Figure 8 Given a commanded outlet pressure, the controller converts the input pressure value into an electrical signal, easily controlling the rotation angle of the DC motor's shaft 1. This shaft 1 is connected to the main valve's pressure-regulating screw, compressing the main valve's pressure-regulating spring 9 to generate a force that moves the main valve core downward, opening the main valve port. The pressure sensor feeds the outlet pressure back to the controller, adjusting it to the commanded pressure, achieving closed-loop control of the outlet pressure.

[0070] Based on the principles of gas flow and pressure distribution within the flow channel of the pressure reducing valve, the model of the flow channel within the pressure reducing valve is simplified to four cavities and five throttle openings. Source gas enters the pressure reducing valve's intake chamber from the inlet, flows through the main valve opening after throttling and reducing pressure, and then flows into the buffer chamber. Gas in the buffer chamber enters the exhaust chamber through the throttle opening. If the pressure in the exhaust chamber is higher than that in the pressure feedback chamber, the gas in the exhaust chamber flows into the pressure feedback chamber through the feedback opening; conversely, the gas in the pressure feedback chamber enters the exhaust chamber through the feedback opening. The gas in the exhaust chamber is discharged into the atmosphere through the outlet. A reasonable feedback opening diameter allows the pressure in the exhaust chamber to be fed back to the pressure feedback chamber, acting on the main valve piston and balancing the force of the main valve pressure regulating spring, thus ensuring that the pressure reducing valve has good static and dynamic characteristics. Based on the corresponding dynamic pneumatic bridge circuit of the pressure reducing valve, a MATLAB / Simulink dynamic simulation model of the pressure reducing valve can be constructed based on the mass flow equation, the gas state equation, and Newton's second law.

[0071] During operation, the desired outlet pressure parameters are pre-entered, and the DC motor is activated. The shaft rotates, driving the main valve pressure-regulating screw, causing the pressure-regulating nut to move downward, compressing the main valve pressure-regulating spring, which in turn pushes the main valve piston downward. The main valve piston, in turn, pushes the main valve core downward via the main valve core push rod, opening the main valve port. Compressed air flows into the inlet chamber, throttles and reduces pressure through the main valve port, and then flows out of the exhaust chamber. When the air pressure acting on the main valve piston in the exhaust chamber balances the spring force applied by the main valve pressure-regulating spring, the main valve port opening remains unchanged, and the output pressure of the exhaust chamber stabilizes. Simultaneously, the output pressure is fed back to the controller via the pressure sensor, which controls the rotation of the DC motor to adjust the opening, thereby ensuring that the output pressure reaches the predetermined value.

[0072] If the input pressure fluctuates, such as the pressure rises instantaneously, the pressure in the exhaust chamber also rises, and the air pressure acting under the main valve piston increases, destroying the original balance. The main valve piston moves upward and compresses the main valve pressure-regulating spring. The main valve core return spring also pushes the main valve core upward, making the main valve port opening smaller, the throttling resistance increased, and the pressure in the exhaust chamber reduced until the main valve piston reaches a new equilibrium position, and vice versa.

[0073] If the output pressure needs to be increased, a new instruction can be input to the DC motor. The DC motor's shaft rotates forward, causing the main valve pressure-regulating spring to be tightened. The spring force is greater than the air pressure below the main valve piston, causing the main valve piston to move downward and the opening of the main valve port to increase, thereby increasing the output pressure and reaching a new balance.

[0074] To reduce the output pressure, a new command can be input to the DC motor. The DC motor output shaft rotates in the opposite direction, relaxing the main valve pressure regulating spring. The air pressure below the main valve piston becomes greater than the spring force, causing the main valve piston to move upward with the relief valve body. The main valve opening is reduced by the action of the main valve core return spring. At this time, the top of the relief valve core presses against the relief valve push rod and moves downward relative to the relief valve body. The relief valve core disengages from the relief valve sealing ring, opening the relief valve and allowing the gas in the exhaust chamber to overflow through the relief valve, thereby reducing the output pressure or returning it to zero. The sensitivity of the relief valve opening can be adjusted by adjusting the relief valve adjusting screw.

[0075] See also Figure 9 The present invention also provides an optimization design method for the above-mentioned electrically driven direct-acting high-pressure pneumatic pressure reducing valve, the optimization design method mainly comprising the following steps:

[0076] Step 1: Build a simulation model of the pressure reducing valve based on the structural principle of the pressure reducing valve.

[0077] Among them, first, a model of the pressure reducing valve as described above is constructed. According to the gas flow principle and pressure distribution law in the flow channel of the pressure reducing valve, the flow channel gas path in the pressure reducing valve model is simplified into a pneumatic bridge shape with four cavities connected to five throttle ports, and is expressed as a dynamic pneumatic bridge; then, based on the gas flow principle of each cavity, a simulation model of the pressure reducing valve is established according to the mass flow equation, the gas state equation, and Newton's second law.

[0078] The dynamic pneumatic bridge circuit cavity portion includes the intake chamber, the buffer chamber, the exhaust chamber, and the pressure feedback chamber; the throttle portion includes an inlet leading to the intake chamber, a main valve port connecting the intake chamber and the buffer chamber, an exhaust port connecting the buffer chamber and the exhaust chamber, a feedback port connecting the exhaust chamber and the pressure feedback chamber, and a gas outlet. The main valve port and gas outlet are variable throttle ports, while the inlet, exhaust port, and feedback port are fixed throttle ports.

[0079] Step 2: Determine the optimization goal and formulate the dynamic characteristic evaluation function, confirm the value range of the design parameters based on the model, and then generate the sample space.

[0080] Step three: using the simulation model to calculate the function values ​​of the pressure characteristics, flow characteristics and dynamic characteristics evaluation function of the pressure reducing valve in the electronically controlled regulation state for each group of samples in the sample space.

[0081] Step 4: The response surface of each design parameter is fitted by the genetic aggregation method for the obtained calculation results, and then the multi-objective genetic algorithm is used to optimize the obtained response surface to determine the optimal design parameters.

[0082] In a specific embodiment, the optimization design method includes the following steps:

[0083] (1) The electric drive direct-acting high-pressure pneumatic pressure reducing valve model was constructed using Solidworks software, and a simulation model of the electric drive direct-acting high-pressure pneumatic pressure reducing valve was constructed in MATLAB / Simulink based on the structural principle of the electric drive direct-acting high-pressure pneumatic pressure reducing valve.

[0084] (2) The design optimization objectives are the pressure characteristics, flow characteristics, and dynamic characteristics of the electrically driven direct-acting high-pressure pneumatic pressure reducing valve under the electronically controlled regulation state, with an inlet pressure of 40 MPa and an outlet pressure of 25 MPa, and an evaluation function is formulated;

[0085] (3) Based on the model, the design parameters are determined: the main valve pressure regulating spring stiffness K1, the main valve core return spring stiffness K2, the main valve piston diameter D1, the feedback hole diameter D2, the moving parts (main valve piston, main valve core, main valve push rod) mass m, the piston pressure feedback chamber volume Vh, the exhaust chamber volume Vb, and the optimized value range is set for the structural design parameters. The Latin hypercube sampling method is used to design the sample space.

[0086] (4) Calculating the pressure characteristics, flow characteristics and dynamic characteristics evaluation function values ​​of the electrically driven direct-acting high-pressure pneumatic pressure reducing valve under the electrically controlled adjustment state based on the simulation model established in step (1) for each group of samples in the sample space, and outputting and arranging the results.

[0087] (5) The genetic aggregation method is used to fit the response surface of each parameter for all sample results, and the multi-objective genetic algorithm is used to optimize the response surface to determine the final optimization parameters and pressure characteristics, flow characteristics, and dynamic characteristics indicators.

[0088] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve, characterized in that: The pressure reducing valve includes a main valve assembly and a relief valve, wherein the relief valve is embedded in the main valve assembly; the relief valve is used to automatically open and exhaust when the pressure reducing valve needs to release pressure or the outlet pressure exceeds the set pressure, so as to complete the pressure release or stabilize the outlet pressure at the set pressure, and the driving force of the relief valve is the difference between the pressure of the compressed air on the two opposite ends of the main valve piston of the main valve assembly and the force of the pressure regulating spring; The main valve assembly includes a DC motor, a main valve upper end cover, a main valve body and a main valve lower end cover connected in sequence, the main valve assembly also includes a main valve piston, and a main valve pressure-regulating screw, a main valve pressure-regulating nut and a main valve pressure-regulating spring arranged in the main valve upper end cover, one end of the main valve pressure-regulating screw is connected to the rotating shaft of the DC motor, and the other end passes through the main valve pressure-regulating nut and enters the main valve pressure-regulating spring, the opposite ends of the main valve pressure-regulating spring respectively abut against the main valve pressure-regulating nut and the main valve piston, and the main valve piston is arranged in the main valve body; The main valve body is a stepped cylinder, and an air inlet cavity and an exhaust cavity are provided on the stepped portion thereof, and the air inlet cavity and the exhaust cavity are both arranged along the radial direction of the main valve body; the stepped portion of the main valve body is also provided with a first pressure gauge interface and a second pressure gauge interface, the second pressure gauge interface is located between the exhaust cavity and the first pressure gauge interface, and the first pressure gauge interface and the second pressure gauge interface are located between the air inlet cavity and the exhaust cavity; the two opposite ends of the main valve body are respectively provided with a first groove and a first threaded hole, the bottom surface of the first groove is provided with a second threaded hole, the bottom surface of the second threaded hole is provided with a second groove, the bottom surface of the second groove is provided with a third groove, and the bottom surface of the third groove is provided with a first connecting hole , the first connecting hole passes through the bottom surface of the first threaded hole; the first pressure gauge interface and the air inlet chamber are respectively connected to the first connecting hole; a feedback hole is provided on the bottom surface of the second groove, and the feedback hole is connected to the exhaust chamber; a first receiving hole is provided on the bottom surface of the second groove; a first vertical channel is provided on the bottom surface of the third groove, and the first vertical channel is connected to the second pressure gauge interface; one end of the lower end cover of the main valve extends into the first groove, the second threaded hole and the second groove, and forms a threaded connection with the second threaded hole, and the steps formed on the outer periphery of the lower end cover of the main valve respectively abut against the bottom surface of the first groove, the bottom surface of the second threaded hole and the bottom surface of the second groove.

2. The electrically driven direct-acting high-pressure pneumatic pressure reducing valve according to claim 1, characterized in that: The lower end cover of the main valve is stepped, and a stepped groove is provided at one end thereof; one end of the lower end cover of the main valve is threadedly connected to the first threaded hole; the main valve assembly also includes a main valve core, and the end of the main valve core used for contacting the overflow valve is conical, and includes a main valve core body, a main valve core sealing ring and a main valve core screw; the main valve core body is a cylinder, and a second boss is provided on the outer periphery of one end thereof, and the second boss is annular; a ninth groove is provided at one end of the main valve core body adjacent to the second boss, and a first stepped hole is provided on the bottom surface of the ninth groove, and the first stepped hole passes through the main valve core body; the main valve core sealing ring portion is arranged in the ninth groove, and one end of the main valve core screw passes through the main valve core sealing ring and is threadedly connected to the first stepped hole.

3. The electrically driven direct-acting high-pressure pneumatic pressure reducing valve according to claim 2, characterized in that: One end of the main valve core body passes through the main valve core return spring, the hole retaining spring, the metal ring and the plastic ring in sequence and enters the stepped groove, and the main valve core body is located in the main valve body; the main valve core body and the bottom surface of the stepped groove are spaced apart to form a balance chamber; the two ends of the main valve core return spring respectively rest on the second boss and the hole retaining spring; the main valve assembly also includes a main valve seat and a partition, the main valve seat is stepped, and is provided with a fifth through hole, and the fifth through hole is used to accommodate part of the main valve core push rod and the main valve core ; One end of the main valve seat is threadedly connected to the first connecting hole, and the step at the other end abuts against the bottom surface of the third groove; the main valve seat is accommodated in the first connecting hole and the third groove; the partition is arranged on the bottom surface of the second groove; the main valve piston sleeve is arranged in the second groove and the third groove, and one end thereof abuts against the partition, and the other end abuts against the upper end cover of the main valve; a buffer chamber is formed between the partition and the bottom surface of the third groove; a pressure feedback chamber is formed between the main valve piston and the partition.

4. The electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve according to claim 3, characterized in that: The relief valve includes a relief valve adjusting spring, a relief valve adjusting screw, a relief valve push rod, a relief valve end cover, a relief valve sealing ring, a relief valve core, a relief valve spring and a relief valve body; the relief valve body is stepped, and a sixth groove is opened in the axial direction, and a second countersunk hole is opened on the bottom surface of the sixth groove; the step portion of the relief valve body is also opened, and the third connecting hole connects the second countersunk hole with the pressure feedback chamber; the step portion of the relief valve body is arranged on the main The valve piston is in the fourth groove at one end away from the DC motor, and its end away from the step portion passes through the locking nut and extends into the overflow valve end cover; the overflow valve sealing ring is arranged in the sixth groove; the overflow valve spool is arranged in the second countersunk hole; one end of the overflow valve spring abuts against the bottom of the second countersunk hole, and the other end is connected to one end of the overflow valve spool, the other end of the overflow valve spool is conical and connected to the overflow valve sealing ring; the overflow valve spool is provided with a through hole.

5. The electrically driven direct-acting high-pressure pneumatic pressure reducing valve according to claim 4, characterized in that: The overflow valve end cover is located in the main valve pressure regulating spring, and a seventh groove is provided at one end of the overflow valve end cover, and the end of the overflow valve body with the sixth groove is arranged in the seventh groove; an eighth groove is provided at the other end of the overflow valve cover, and a fourth connecting hole is provided on the bottom surface of the second groove, and the fourth connecting hole passes through the bottom surface of the seventh groove and is connected with the through hole; the overflow valve end cover is also provided with a radially arranged fourth through hole, and the fourth through hole passes through the eighth groove and at the same time passes through the overflow valve end cover, and is connected with the fifth groove opened at the other end of the main valve piston.

6. The electrically driven, direct-acting, high-pressure pneumatic pressure reducing valve according to claim 5, characterized in that: One end of the relief valve push rod is arranged in the eighth groove, and the other end is arranged in the third through hole of the main valve pressure regulating screw; one end of the relief valve adjusting screw is arranged in a first countersunk hole opened in the main valve pressure regulating screw and connected to the third through hole, and the other end passes through the relief valve adjusting spring and abuts against the relief valve push rod; the pressure reducing valve also includes a pressure sensor and a controller, the pressure sensor is arranged in the outlet pipe of the pressure reducing valve, for detecting the outlet pressure and transmitting the detected outlet pressure value to the controller; the controller outputs a control instruction to the DC motor based on the pressure value received from the pressure sensor, so as to control the DC motor, and then adjust the outlet pressure to the target value.

7. An optimization design method for an electrically driven direct-acting high-pressure pneumatic pressure reducing valve, characterized in that: The method comprises the following steps: Step 1: Building a simulation model of the pressure reducing valve based on the structural principle of the pressure reducing valve according to any one of claims 1 to 6; Step 2: Determine the optimization goal and formulate the pressure characteristic, flow characteristic and dynamic characteristic evaluation function, confirm the value range of the design parameters based on the model, and then generate the sample space; Step 3, using the simulation model to calculate the function values ​​of the pressure characteristics, flow characteristics and dynamic characteristics evaluation function of the pressure reducing valve in the electronically controlled regulation state for each group of samples in the sample space; Step 4: The response surface of each design parameter is fitted by the genetic aggregation method for the obtained calculation results, and then the multi-objective genetic algorithm is used to optimize the obtained response surface to determine the optimal design parameters.

8. The optimization design method for an electrically driven direct-acting high-pressure pneumatic pressure reducing valve according to claim 7, characterized in that: In step one, first, a model of the pressure reducing valve is constructed. According to the gas flow principle and pressure distribution law in the flow channel of the pressure reducing valve, the gas path in the flow channel of the model of the pressure reducing valve is simplified into a pneumatic bridge shape in which four cavities are connected to five throttle ports, and is expressed as a dynamic pneumatic bridge. Then, based on the gas flow principle of each cavity, a simulation model of the pressure reducing valve is established according to the mass flow equation, the gas state equation, and Newton's second law.

Images