Pilot-operated type duplex electromagnetic valve

Abstract

The pilot-operated type duplex electromagnetic valve comprises a bottom plate, a supporting seat, a cover plate, a movable shaft, a shaft sleeve, an elastic reset assembly and an air path switching assembly. A multi-stage cavity and a channel which are used for forming a main gas path are arranged in the bottom plate, and the supporting seat is used for positioning the shaft sleeve and the movable shaft and constructing a gas inlet, gas outlet and connecting channel. The movable shaft is composed of a multi-stage sealing structure and can reciprocate between an opening position and a closing position under the action of pilot pressure and a reset spring, and therefore air inlet control and air exhaust control of a main air path are achieved. An air inlet cavity and an exhaust cavity are formed in the cover plate and communicate with the air path switching assembly, so that pilot air can selectively act on different control cavities, and the movable shaft is driven to complete corresponding air path switching. The gas path switching assembly forms a pilot loop through a set gas inlet, a set gas outlet and a set gas outlet, so that the duplex structure can achieve independent gas inlet and gas outlet operation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pneumatic control, and particularly relates to a pilot type double electromagnetic valve. BACKGROUND

[0002] In the fields of medical rehabilitation equipment, industrial automation control devices, and external counterpulsation systems, etc. that need to switch high-frequency gas, electromagnetic valves are the core components for regulating the inflation and deflation processes. The existing devices generally use balanced electromagnetic valves or single-stage direct-acting electromagnetic valves to control the on-off of the main gas path. However, in high-pressure, large-flow or fast-response working conditions, the traditional balanced structure has many limitations. For example, the direct-acting valve core directly bears the pressure of the main gas path, and when the gas pressure is high, the valve core is difficult to overcome the pressure to complete the opening and closing action, and conditions such as "high-pressure cannot be closed" or valve core jamming are prone to occur. At the same time, the internal chamber arrangement of the valve body is relatively simple, and it is difficult to effectively disperse the pressure of different cavities, resulting in the need to increase the size of the structure to improve the strength.

[0003] In addition, when performing inflation and deflation switching actions, the existing electromagnetic valves often rely on a single valve core to repeatedly open and close, and in high-frequency reciprocating working conditions, problems such as fatigue wear, aging of the sealing gasket, and increased leakage are prone to occur. Due to the large change in gas pressure at both ends of the valve core and uneven stress, the traditional structure is difficult to achieve long-term stable action coordination. At the same time, the commonly used single-valve core structure is difficult to achieve bidirectional fast switching in a limited space, forcing equipment manufacturers to increase additional pipelines or add multiple valve bodies, further increasing system complexity and cost.

[0004] For application scenarios such as external counterpulsation equipment that require high-pressure and high-frequency switching, the existing technology generally needs to configure larger gas storage tanks to compensate for the flow loss caused by insufficient valve body response, which not only increases the size of the entire machine and limits the layout space, but also reduces the convenience of use to some extent. On the other hand, some electromagnetic valves lack effective pilot pressure auxiliary mechanisms, making the valve core unable to work smoothly under high-pressure conditions, and problems such as uneven inflation and deflation rhythm, increased valve body noise, and decreased system reliability are prone to occur. SUMMARY

[0005] In view of the problems existing in the prior art, the purpose of the present application is to provide a pilot type double electromagnetic valve that overcomes the technical problem of difficulty in size reduction. In this context, there is an urgent need for a double electromagnetic valve structure that can partition through multi-cavity structure, assist driving through pilot gas pressure, and maintain stable movement of the valve core during bidirectional gas path switching, to solve the technical problem that traditional electromagnetic valves cannot simultaneously achieve high-pressure sealing, large-flow switching capability, and high-frequency action reliability.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The application discloses a pilot type duplex electromagnetic valve, which comprises a valve body structure, a cover plate structure, a valve core assembly, an axial guide assembly, an elastic reset assembly and a gas path switching assembly; a main gas path channel is formed in the valve body structure; the valve core assembly can reciprocate between a closed position and an open position under the action of gas pilot pressure and the action of elastic reset force, so that the gas inlet and gas outlet of the main gas path are controlled; the cover plate structure is provided with a pilot gas path channel and is connected with the gas path switching assembly, so that the pilot gas path can be selectively conducted to the control cavity of the valve core assembly or discharged; the axial guide assembly is used for supporting the reciprocating movement of the valve core assembly and realizing multi-stage sealing; the gas path switching assembly is used for controlling the on-off of the pilot gas flow; different valve core assemblies are driven by the pilot pressure to respectively perform the gas inlet control and the gas outlet control; and the duplex structure balances the stress of the valve core assembly through the pilot action, so that the valve can keep stable action under high pressure and high frequency conditions.

[0008] Further, the valve body structure comprises a bottom plate, the bottom plate is provided with a groove, a first cylinder, a circular hole, a second cylinder, a through hole and a cylindrical recess, and is used for accommodating a shaft sleeve, a movable shaft and realizing the communication of various gas paths.

[0009] Further, the axial guide assembly comprises a shaft sleeve, the shaft sleeve is provided with a step for positioning and an annular groove for mounting a sealing element, and is fixed to the corresponding recessed table position of the support seat through the step.

[0010] Further, the support seat is provided with a screw hole, a first recessed table, a second recessed table, an exhaust hole, an air outlet hole, a first stud, a second stud, a third stud, an air inlet hole, a connecting hole, a third recessed table and a fourth recessed table, which are used for realizing the fixation, positioning and gas path arrangement of various functional components.

[0011] Further, the valve core assembly comprises a movable shaft, the movable shaft is provided with a protruding block, and the two ends of the movable shaft are respectively provided with a first rubber pad and a second rubber pad, which are used for forming a seal between different cavities in the valve body and controlling the on-off of the gas.

[0012] Further, a friction ring is mounted on the outer side of the movable shaft, which is used for reducing the friction resistance between the movable shaft and the shaft sleeve during the reciprocating movement of the movable shaft.

[0013] Further, the elastic reset assembly comprises a spring cap and a reset spring, the spring cap is provided with a cylindrical hole for accommodating the reset spring, and the bottom end of the spring cap is provided with a small protruding block for cooperating with the groove at the end of the movable shaft, so as to realize the stable positioning of the reset spring.

[0014] Further, the cover plate is formed with an exhaust cavity and an air inlet cavity, which are used for providing a pilot gas flow to the top of the movable shaft and forming a closed loop pilot path with the switching valve assembly.

[0015] Further, the air path switching assembly is a valve, a sealing ring is arranged on the valve, and the air inlet, air outlet and exhaust outlet of the valve are connected with the pilot air path on the cover plate respectively, and are used for selectively providing pilot air pressure to drive different valve cores to act.

[0016] Further, the pilot air path inlet is provided with a quick connector, and the pilot air enters the internal passage of the cover plate through the quick connector and acts on the movable shaft control cavity, so that the air inlet valve core and the exhaust valve core are independently driven by the pilot.

[0017] Compared with the prior art, the beneficial effects of the present application are:

[0018] The existing balanced electromagnetic valve directly bears the main air path pressure on the valve core under high pressure working condition, and problems such as not tight, difficult opening and closing, and uneven force are prone to occur. By introducing the valve body structure of multiple cavities, and arranging multiple channels and grooves inside, the main air path is separated by different cavities, so that the main air path pressure does not directly act on the valve core body. The valve core assembly can form pressure balance between the upper cavity and the lower cavity under the action of the pilot air, so as to avoid the valve core from being unable to close due to uneven pressure, thereby effectively improving the opening and closing reliability in high pressure environment.

[0019] The existing electromagnetic valve is prone to deviation or jamming in reciprocating motion due to the lack of reasonable guide structure of the valve core. The axial guide assembly including the shaft sleeve, the sliding guide surface and the multi-stage seal is adopted, so that the movement of the movable shaft is always in a stable guide state, and the friction ring is used to reduce the friction resistance of reciprocating motion, so that the valve core maintains linear motion trajectory in the process of high frequency starting and stopping, and maintains stable action in long-term use.

[0020] In the traditional structure, the sealing of the valve core depends on a single rubber pad, and the sealing surface is easy to wear in high pressure and high speed switching, resulting in increased leakage. The valve core structure with multiple sealing surfaces is combined, multiple rubber pads and annular sealing grooves are arranged, so that independent sealing layers are formed between different functional cavities. The multi-stage sealing structure not only reduces the stress of single sealing surface, but also keeps the sealing stable for a long time under high pressure circulation condition, and significantly improves the service life.

[0021] The existing balanced electromagnetic valve cannot quickly respond to high pressure switching, and needs to cooperate with a large capacity gas tank to maintain supply and demand balance, resulting in significant expansion of the device volume. By setting a pilot structure, the opening and closing of the valve core are no longer dependent on the main air path pressure, but are driven by stable pilot air, so that the valve body can also quickly respond under high pressure condition. This structure significantly reduces the dependence on the capacity of the gas tank, so that the overall volume of the device can be reduced.

[0022] The internal passage layout of the traditional valve body is single, the air inlet and exhaust paths are prone to interference, and the pressure fluctuation is significant. By forming an air inlet cavity, an exhaust cavity, a connecting channel and a pilot cavity inside the support seat and the cover plate, the various functional channels are strictly separated and do not interfere with each other. The flow of gas between the cavities is more stable, the pressure change during switching is more controllable, and consistent response characteristics can still be maintained under high-frequency operation.

[0023] The sealing performance of the pilot gas interface of the traditional structure is limited, which causes the pilot pressure to be unstable, affecting the synchronicity and response speed of the valve core action. An independently arranged pilot gas inlet structure is adopted, which is in close communication with the pilot cavity inside the cover plate, so that the pilot gas source input is more rapid, the gas loss is smaller, the valve core action under the control of the pilot pressure is more sensitive, and the overall control precision is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is an exploded view of the embodiment;

[0025] Figure 2 is a perspective view of the bottom plate of the embodiment Figure 1 ;

[0026] Figure 3 is a perspective view of the bottom plate of the embodiment Figure 2 ;

[0027] Figure 4 is a perspective view of the shaft sleeve of the embodiment;

[0028] Figure 5 is a perspective view of the support seat of the embodiment Figure 1 ;

[0029] Figure 6 is a perspective view of the support seat of the embodiment Figure 2 ;

[0030] Figure 7 is a perspective view of the friction ring of the embodiment;

[0031] Figure 8 is a perspective view of the movable shaft of the embodiment Figure 1 ;

[0032] Figure 9 is a perspective view of the movable shaft of the embodiment Figure 2 ;

[0033] Figure 10 is a perspective view of the air inlet valve movable shaft of the embodiment Figure 1 ;

[0034] Figure 11 is a perspective view of the air inlet valve movable shaft of the embodiment Figure 2 ;

[0035] Figure 12 is a perspective view of the cover plate of the embodimentFigure 1 ;

[0036] Figure 13 Isometric view of the cover plate for the embodiment Figure 2 ;

[0037] Figure 14 Isometric view of the cover plate for the embodiment Figure 3 ;

[0038] Figure 15 Isometric view of the switch valve for the embodiment

[0039] Figure 16 Front view of the valve assembly for the embodiment

[0040] Figure 17 Sectional view A-A of the valve assembly for the embodiment

[0041] Figure 18 Sectional view B-B of the valve assembly for the embodiment

[0042] In the drawings, the components represented by the respective reference numbers are listed as follows:

[0043] 10, screw; 11, bottom plate; 1101, groove; 1103, first cylinder; 1105, round hole; 1111, second cylinder; 1114, through hole; 1115, cylindrical recess; 15, shaft sleeve; 1502, step; 1503, annular groove;

[0044] 17, support seat; 1701, screw hole; 1704, first recess; 1705, second recess; 1709, exhaust hole; 1710, air outlet hole; 1711, first stud; 1712, second stud; 1713, third stud; 1714, air inlet hole; 1715, connecting hole; 1716, third recess; 1717, fourth recess;

[0045] 18, friction ring;

[0046] 20, movable shaft; 2001, protrusion; 2002, first rubber pad; 2003, second rubber pad; 21, spring cap; 2101, cylindrical hole; 2103, small boss; 24, cover plate; 2412, exhaust cavity; 2421, air inlet cavity;

[0047] 25, valve switch; 2505, sealing ring;

[0048] 27, return spring; 28, quick connector. DETAILED DESCRIPTION

[0049] In order to make the purposes and advantages of the present application more clear and understandable, the present application is specifically described below in conjunction with embodiments. It should be understood that the following description is merely used to describe one or several specific embodiments of the present application and does not strictly limit the scope of protection specifically requested by the present application.

[0050] Referring to Figures 1-18 A pilot type duplex electromagnetic valve includes a valve body structure, a cover plate 24 structure, a valve core assembly, an axial guide assembly, an elastic reset assembly, and a gas path switching assembly. The existing balanced electromagnetic valve cannot be reliably closed under high pressure conditions, and the valve core is prone to jamming, sealing attenuation, and response speed reduction under the influence of the main gas path pressure in long-term high-frequency operation, which further leads to the need for a larger gas storage tank to maintain supply and demand balance, resulting in an oversized overall machine, complex structure, and inconvenient maintenance. In view of the above problems of high-pressure non-closing, non-sensitive opening and closing, and large structure occupying space, a main gas path channel is formed in the valve body structure, and the valve core assembly can reciprocate between the closed position and the open position under the action of the gas pilot pressure and the elastic reset force, realizing more reliable gas inlet and exhaust switching under high-pressure environment. The cover plate 24 structure is provided with a pilot gas path channel and connected with the gas path switching assembly, so that the pilot gas path can be selectively conducted or discharged to the control cavity of the valve core assembly, thereby forming stable pilot driving under the uneven force condition of the valve core. The axial guide assembly is used to support the reciprocating motion of the valve core assembly and realize multi-stage sealing, reducing wear and improving gas sealing reliability in high-frequency repeated operation. The gas path switching assembly is used to control the on-off of the pilot gas flow, and different valve core assemblies are driven by the pilot pressure to perform gas inlet control and exhaust control respectively, forming a dual-path independent switching structure to avoid fatigue damage of the traditional single valve core structure in high-frequency operation. The duplex structure balances the stress of the valve core assembly through the pilot action, so that the valve maintains stable operation under high pressure and high frequency conditions, thereby solving the problems of large structure volume, easy sealing attenuation, and unstable operation of the traditional electromagnetic valve structure.

[0051] Referring to Figures 1-2The valve body structure includes a base plate 11, on which are provided a groove 1101, a first cylinder 1103, a circular hole 1105, a second cylinder 1111, a through hole 1114, and a cylindrical concave hole 1115, for accommodating the bushing 15, the movable shaft 20, and enabling communication between various air passages. Existing valve bodies have a single internal cavity arrangement during high-pressure air passage switching, making it difficult to simultaneously achieve multi-cavity partitioning within a limited space. This results in high flow resistance in the main air passage, uneven pressure on the valve core, and shortened sealing life. To solve the problem of high-pressure gas passage... Outdated valve bodies cannot effectively separate internal cavities and are prone to valve core instability. The base plate 11 forms an independent exhaust area through the groove 1101, and provides a positioning reference for the bushing 15 through the first cylinder 1103 and the second cylinder 1111. A vertically connected air passage is established through the round hole 1105 and the through hole 1114, and a countersunk structure is provided for the screw 10 through the cylindrical concave hole 1115. This allows the valve body structure to complete the division of multiple cavities and high-pressure air passage guidance in a compact space, improving the stability and sealing of the whole machine.

[0052] See Figures 1-4 The axial guide assembly includes a bushing 15, which has a step 1502 for positioning and an annular groove 1503 for installing a seal. The bushing 15 is fixed to the corresponding recessed positions of the support base 17 via the step 1502. Traditional pneumatic valves generally suffer from uneven force distribution and insufficient guidance in the valve core guiding structure. Especially during high-pressure rapid switching, valve core tilting, increased friction, or seal failure may occur, thus affecting the stability of the valve core reciprocating motion. To solve the above problems of loose structure and insufficient guidance, the bushing 15 forms a multi-point stable support with the first recessed platform 1704, the second recessed platform 1705, the third recessed platform 1716, and the fourth recessed platform 1717 on the support base 17 via the step 1502. The sealing ring is installed in the annular groove 1503 to achieve axial sealing, so that the movable shaft 20 can still maintain linear guiding motion under high pressure, avoid valve core force deviation, and improve the overall response speed and structural stability.

[0053] See Figure 5, the support seat 17 is provided with screw holes 1701, a first recess 1704, a second recess 1705, exhaust holes 1709, air outlet holes 1710, first studs 1711, second studs 1712, third studs 1713, air inlet holes 1714, connecting holes 1715, a third recess 1716 and a fourth recess 1717, for realizing the fixation, positioning and gas passage arrangement of various functional components; the existing electromagnetic valve generally has the problems of single cavity, serious cross interference of flow channels and crowded structure arrangement in the support structure, which causes pressure fluctuation and gas leakage when high-frequency gas switching occurs; in order to improve the problem of disordered gas path layout, the support seat 17 is stably connected with the bottom plate 11 through the screw holes 1701, three functional air flow paths are formed through the air inlet holes 1714, the air outlet holes 1710 and the exhaust holes 1709, the pilot gas is upwardly and downwardly conveyed through the first studs 1711, the second studs 1712 and the third studs 1713, and the signal gas is connected between different cavities through the connecting holes 1715, so that the entire valve body can still maintain clear and independent gas paths under high-pressure environment, and the gas switching efficiency and stability are improved.

[0054] Referring to Figures 11-13 , the valve core assembly includes a movable shaft 20, the movable shaft 20 is provided with a protrusion 2001, and the two ends of the movable shaft 20 are respectively provided with a first rubber pad 2002 and a second rubber pad 2003, for forming a seal between different cavities in the valve body and controlling the on-off of the gas; the traditional valve core lacks effective multi-point sealing structure under high-pressure working conditions, and the rubber pad is easily deformed or leaked due to impact force, so that high-pressure, large-flow and high-frequency rapid switching cannot be realized; in order to solve this sealing attenuation problem, the movable shaft 20 uses the protrusion 2001 to realize the up-down direction limiting, and the first rubber pad 2002 and the second rubber pad 2003 form two-stage sealing with the cavities in the bottom plate 11 and the support seat 17 respectively, so that the main gas path can realize reliable switching between opening and closing, and further ensure that the valve core assembly can maintain stable sealing effect under high-pressure environment.

[0055] Referring to Figures 11-13 , the movable shaft 20 is provided with a friction ring 18 outside, for reducing the friction resistance between the movable shaft 20 and the shaft sleeve 15 during reciprocating motion; the traditional direct-acting valve core is prone to problems such as poor guidance and sealing surface deviation due to surface wear during repeated high-speed motion; in order to solve the problem of unsmooth operation of the valve core, a low-friction sliding interface is formed between the friction ring 18 and the shaft sleeve 15, so that the movable shaft 20 still maintains stable reciprocating motion under the action of pressure changes in multiple cavities, and the reliability of the valve body in high-frequency operation is improved.

[0056] Referring to Figures 11-18, the elastic reset assembly includes spring cap 21 and reset spring 27, the spring cap 21 is provided with cylindrical hole 2101 for accommodating reset spring 27, the bottom end of spring cap 21 is provided with small boss 2103 for cooperating with the groove 1101 of the end of the movable shaft 20, the stable positioning of the reset spring 27 is realized;The traditional reset structure is prone to spring deviation, uneven stress and other conditions in long-term operation, so that the valve core cannot be stably reset;In order to avoid such problems, the spring cap 21 is reliably clamped with the movable shaft 20 through the small boss 2103, so that the reset spring 27 is always in axial stress condition, and the quick reset of the valve core after the release of the pilot pressure is realized.

[0057] Referring to Figures 11-18 , the cover plate 24 is formed with exhaust cavity 2412 and intake cavity 2421, which are used to provide pilot flow to the top of the movable shaft 20 and form a closed loop pilot passage with the valve 25 assembly;The existing electromagnetic valve lacks stable pilot cavity arrangement, and is prone to pressure fluctuation in high pressure environment;In order to solve the above problems, the cover plate 24 builds up and down pilot cavities through the exhaust cavity 2412 and the intake cavity 2421, so that the pilot pressure can be stably transmitted to the movable shaft 20, and balanced action under pilot driving is realized.

[0058] Referring to Figure 15 , the gas path switching assembly is the valve 25, the valve 25 is provided with a sealing ring 2505, the gas inlet, gas outlet and exhaust of which are connected with the pilot gas path on the cover plate 24 respectively, which is used to selectively provide pilot gas pressure to drive different valve cores to act;The structure of the traditional gas path switching assembly is single, and cannot form independent pilot control of intake and exhaust, resulting in different response of the equipment in complex working conditions;In order to improve the accuracy of the pilot gas path, the valve 25 realizes gas path isolation through the sealing ring 2505, so that the pilot signal can control different cavities respectively, and the overall gas flow switching efficiency is improved.

[0059] Referring to Figure 16 , the pilot gas path inlet is provided with a quick connector 28, and the pilot gas enters the internal passage of the cover plate 24 through the quick connector 28 and acts in the control cavity of the movable shaft 20, so as to realize independent pilot driving of the intake valve core and the exhaust valve core;The existing gas path interface is often difficult to maintain airtightness in high frequency operation, which is prone to pilot gas shortage or leakage;In order to solve this problem, the quick connector 28 forms a reliable interface, so that the pilot gas pressure is stably transmitted, and the reliability of the pilot driving is improved.

[0060] The working principle of the application is:

[0061] The pilot double electromagnetic valve is normally closed structure, its core is composed of bottom plate 11, support seat 17, cover plate 24, movable shaft 20, shaft sleeve 15, valve 25 and reset spring 27 and other components, through the pilot gas path driven movable shaft reciprocating, realize the intake control and exhaust control of main gas path. The recess 1101, the first cylinder 1103, the round hole 1105, the second cylinder 1111, the through hole 1114 and the cylindrical recess 1115 provided on the bottom plate 11 form the basic chamber and the installation reference of the valve body bottom, the shaft sleeve 15 is stably installed in the cylindrical hole position of the bottom plate through the step 1502, and the annular groove 1503 is used for installing the sealing ring to form the axial seal. The movable shaft 20 is assembled in the shaft sleeve and can slide along the axial direction, the convex block 2001 and the first rubber pad 2002 and the second rubber pad 2003 at both ends are arranged on the movable shaft and are used for sealing different cavities in the valve body respectively, the friction ring 18 assembled on the outer side of the movable shaft plays a role of reducing friction and guiding in the movement process. The recess for installing the spring cap 21 is arranged on the upper end of the movable shaft, the cylindrical hole 2101 of the spring cap is used for accommodating the reset spring 27, and the small boss 2103 is matched with the recess of the movable shaft to ensure the stable positioning of the spring. The support seat 17 is fixed on the bottom plate, and the inside of the support seat is formed with the intake hole 1714, the exhaust hole 1710, the exhaust hole 1709, the first threaded column 1711, the second threaded column 1712, the third threaded column 1713, the connecting hole 1715, the first recess 1704, the second recess 1705, the third recess 1716 and the fourth recess 1717, and these chambers and installation steps correspond to the fixation of the shaft sleeve, the movement of the movable shaft and the communication between the gas paths respectively. The cover plate 24 is fixed on the support seat 17 through the screw 10, the inside of the cover plate is formed with the exhaust cavity 2412 and the intake cavity 2421, and the pilot gas path for communicating with the valve 25 is formed in the cavities. The valve 25 is provided with a sealing ring 2505 for ensuring the air tightness between the valve and the cover plate, and the valve can selectively guide the pilot gas source to the exhaust cavity 2412 or the intake cavity 2421. The pilot gas source enters the inside of the cover plate through the quick connector 28.

[0062] When the intake function is realized, the high-pressure gas first enters the support seat inside through the intake hole 1714, enters the bottom plate 11 inside cavity through the connecting hole 1715, and the gas passes through the inner channel of the shaft sleeve 15 to the lower end area of the movable shaft 20, so that the cavity where the second rubber pad 2003 is located is subjected to the pressure of the main gas path. At the same time, part of the gas rises along the first stud 1711, enters the intake port of the valve 25 through the intake cavity 2421 of the cover plate 24. When the valve is in the intake pilot state, the internal channel is switched to make the pilot gas from the valve outlet enter the top area of the movable shaft through the passage on the cover plate, and the pilot gas acts on the upper end of the movable shaft to form the upper cavity pressure, so that the movable shaft overcomes the elastic force of the reset spring 27 and moves downward. With the movable shaft moving downward, the rubber pad 2002 or 2003 at the end of the movable shaft is separated from the corresponding valve seat, and the main gas path between the bottom plate 11 and the support seat 17 is opened. At this time, the main gas enters the bottom plate cavity through the intake hole 1714 and the connecting hole 1715, and then is discharged to the air bag or external load through the exhaust hole 1710, realizing rapid inflation.

[0063] When the intake is needed to be closed, the valve 25 is switched to the position of discharging the pilot gas, the pilot gas path is communicated with the atmosphere, the pilot cavity pressure at the top of the movable shaft is rapidly released, the reset spring 27 restores the elastic force, the movable shaft 20 moves upward and re-presses the rubber pad 2002 or 2003, thereby closing the main gas path, and the intake process is completed.

[0064] The exhaust action is similar to the intake action, and the exhaust direction is completed by another group of cavities and the movable shaft. When the exhaust function is executed, the pilot gas enters the cover plate exhaust cavity 2412 through the quick connector 28, is guided into the valve 25 through the internal gas path of the cover plate, and is selectively guided by the valve to the control cavity on the exhaust side of the movable shaft. The movable shaft opens the exhaust valve seat, so that the gas in the air bag enters the exhaust hole 1709 of the support seat through the groove 1101 and the circular hole 1105 of the bottom plate 11, and is discharged to the outside. When the valve switches to close the exhaust pilot passage, the pilot cavity is depressurized, the reset spring 27 pushes the movable shaft to return to the original position, and the exhaust cavity is resealed.

[0065] The whole process relies on the multi-cavity, multi-path pilot structure formed between the cover plate 24, the bottom plate 11, the shaft sleeve 15, the movable shaft 20, the valve 25, the reset spring 27 and the support seat 17, and the pilot gas is used to offset the pressure of the main gas path, so that the valve core can still easily open and close in a high-pressure and high-frequency environment. The pilot type double electromagnetic valve has the structural advantages of small size, high reliability and sensitive action.

[0066] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application. The structures, devices and operation methods not specifically described and explained in the present application are implemented according to the conventional means in the art, unless specifically described and limited.

Claims

1. A pilot-operated dual solenoid valve, comprising a valve body structure, a cover plate structure, a valve core assembly, an axial guide assembly, an elastic reset assembly, and a gas path switching assembly; a main gas path channel is formed within the valve body structure, and the valve core assembly can reciprocate between a closed position and an open position under the action of pilot gas pressure and elastic reset force, thereby controlling the intake and exhaust of the main gas path; a pilot gas path channel is provided on the cover plate structure and connected to the gas path switching assembly, enabling the pilot gas path to selectively conduct or discharge to the control chamber of the valve core assembly; the axial guide assembly is used to support the reciprocating motion of the valve core assembly and achieve multi-stage sealing; the gas path switching assembly is used to control the on / off of the pilot gas flow, driving different valve core assemblies to perform intake control and exhaust control respectively through pilot pressure; the dual structure balances the force on the valve core assembly through pilot action, enabling the valve to maintain stable operation under high pressure and high frequency conditions.

2. The pilot-operated double solenoid valve according to claim 1, characterized in that: The valve body structure includes a base plate (11), on which are provided a groove (1101), a first cylinder (1103), a round hole (1105), a second cylinder (1111), a through hole (1114), and a cylindrical concave hole (1115) for accommodating the bushing, the movable shaft, and for connecting the various air passages.

3. The pilot-operated double solenoid valve according to claim 2, characterized in that: The axial guide assembly includes a bushing (15), which has a step (1502) for positioning and an annular groove (1503) for installing a seal, and is fixed to the corresponding recessed position of the support seat by the step.

4. A pilot-operated double solenoid valve according to claim 1, characterized in that: The support base (17) is provided with screw holes (1701), a first recess (1704), a second recess (1705), an exhaust hole (1709), an air outlet (1710), a first stud (1711), a second stud (1712), a third stud (1713), an air inlet (1714), a connecting hole (1715), a third recess (1716), and a fourth recess (1717) to realize the fixing, positioning, and gas channel arrangement of each functional component.

5. A pilot-operated double solenoid valve according to claim 4, characterized in that: The valve core assembly includes a movable shaft (20) with a protrusion (2001) on it. A first rubber pad (2002) and a second rubber pad (2003) are respectively installed at both ends of the movable shaft to form a seal between different cavities inside the valve body and control the flow of gas.

6. A pilot-operated double solenoid valve according to claim 1, characterized in that: A friction ring (18) is installed on the outside of the movable shaft to reduce the frictional resistance between the movable shaft and the bushing during reciprocating motion.

7. A pilot-operated double solenoid valve according to claim 6, characterized in that: The elastic reset assembly includes a spring cap (21) and a reset spring (27). A cylindrical hole (2101) is provided on the spring cap to accommodate the reset spring. A small boss (2103) is provided at the bottom of the spring cap to cooperate with the groove at the end of the movable shaft to achieve stable positioning of the reset spring.

8. A pilot-operated double solenoid valve according to claim 7, characterized in that: An exhaust chamber (2412) and an intake chamber (2421) are formed on the cover plate (24) for providing pilot airflow to the top of the movable shaft and forming a closed-loop pilot passage with the pilot air and the switching valve assembly.

9. A pilot-operated double solenoid valve according to claim 1, characterized in that: The air path switching component is a switching valve (25), and a sealing ring (2505) is provided on the switching valve. Its air inlet, air outlet and exhaust port are respectively connected to the pilot air path on the cover plate, which is used to selectively provide pilot air pressure to drive different valve cores to move.

10. A pilot-operated double solenoid valve according to claim 1, characterized in that: The pilot air inlet is equipped with a quick connector (28). After the pilot air enters the internal channel of the cover plate through the quick connector, it acts on the control cavity of the movable shaft, thereby realizing independent pilot drive of the intake valve core and the exhaust valve core.

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