Diaphragm type air spring stiffness valve

Abstract

The invention belongs to a diaphragm type air spring stiffness valve in the technical field of air spring systems. The diaphragm (13) is sleeved on the push rod (17) from one side of the push rod big head (17-2) through a central hole (13-3) of the diaphragm central hard core part (13-2), the diaphragm convex part (13-1) falls into the front yoke sleeve diaphragm groove (7-1) of the front yoke sleeve (7), the gland (14) is pressed into the front yoke sleeve (7) in an interference manner and tightly presses the diaphragm convex part (13-1), and the pressing plate (12) is pressed on one side of the push rod big head (17-2) in an interference manner and tightly presses the diaphragm central hard core part (13-2). The diaphragm type air spring stiffness valve is simple in structure and reliable in control, good sealing performance is guaranteed in the moving process of the valve element, meanwhile, friction resistance can be remarkably reduced, and the action of an electromagnetic valve is smoother.

Description

Technical Field

[0001] The invention belongs to the technical field of air spring systems, and more specifically, relates to a diaphragm type air spring stiffness valve. Background Art

[0002] The air spring stiffness valve is used in dual-chamber and multi-chamber air spring systems. It is a component used to change the stiffness of the air spring. The stiffness valve changes the connection between different chambers of the air spring by opening and closing, realizing the variable working volume, thereby changing the stiffness of the air spring. Air spring stiffness valves are widely used in air spring systems to improve the ride smoothness of the car, provide a good driving experience, and improve the comfort of vehicle driving. In related technologies, in order to ensure the radial dynamic seal when the stiffness valve core is in action, a sealing lip structure is mostly used. In the process of achieving sealing performance, the compression amount of this structure is difficult to control: too little compression will lead to poor sealing performance, and too much compression will increase the resistance of the valve core movement.

[0003] In the prior art, there is a technology named "A stiffness-adjustable air spring assembly based on dual stiffness valves and multiple chambers" and with a publication (announcement) number of "CN118423393A". This technology belongs to the technical field of air spring assemblies, and in particular relates to a stiffness-adjustable air spring assembly based on dual stiffness valves and multiple chambers. The present application is divided into three independent air chambers by two independently controlled solenoid valves and a matching structure. The first solenoid valve and the second solenoid valve are installed in these components and form a channel for controlling the flow of gas. The air chambers are connected and disconnected by independently controlling the power on and off of the solenoid valves, thereby changing the number of open air chambers of the air spring assembly, and then changing the actual use volume of the air spring assembly, so that the air spring assembly has multiple working states and realizes the stiffness adjustment function.

[0004] However, this technology does not involve the technical problems and technical solutions of the present application. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a diaphragm air spring stiffness valve with a simple structure and reliable control is provided, which can significantly reduce the friction resistance while ensuring good sealing performance during the movement of the valve core, so that the solenoid valve can move more smoothly and improve performance.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is:

[0007] The present invention is a diaphragm type air spring stiffness valve, in which the diaphragm comprises an outer convex portion of the diaphragm and a hard core portion in the center of the diaphragm. The diaphragm is sleeved on the convex portion of the push rod from the big end side of the push rod through the center hole of the hard core portion in the center of the diaphragm. The outer convex portion of the diaphragm falls into the diaphragm groove of the front yoke sleeve of the front yoke sleeve. The pressure cover is press-fitted into the front yoke sleeve and presses the outer convex portion of the diaphragm. The pressure plate is press-fitted on the big end side of the push rod and presses the hard core portion in the center of the diaphragm.

[0008] The push rod comprises a push rod convex part, the push rod part on one side of the push rod convex part is the push rod big end, the push rod part on the other side of the push rod convex part is the push rod small end, and the hard core part in the center of the diaphragm presses against the push rod convex part.

[0009] The buffer spring and the front yoke sleeve are sequentially sleeved on the outer ring of the push rod from one side of the small head of the push rod, and the buffer spring presses against the convex part of the push rod.

[0010] The valve core sub-assembly of the diaphragm type air spring stiffness valve is interference-pressed on the push rod from one side of the push rod's big end, and the valve core sub-assembly fits the pressure plate.

[0011] The main spring of the diaphragm type air spring stiffness valve is sleeved on the push rod from the side of the push rod small end, the magnetic core body is interference pressed on the push rod from the side of the push rod small end, and the main spring is pressed between the magnetic core body and the front yoke sleeve.

[0012] The guide sleeve and the front yoke sleeve of the diaphragm type air spring stiffness valve are press-fitted and laser-welded into one body, and the guide sleeve is located at the outer ring position on one side of the push rod small head of the push rod.

[0013] The outer rings of the guide sleeve and the front yoke sleeve are mounted on the solenoid subassembly, and the outer ring of the solenoid subassembly is mounted on the outer shell.

[0014] The outer ring of the front yoke sleeve is sleeved with a front yoke sleeve sealing ring, which is located between the front yoke sleeve and the valve sleeve. The outer shell riveting compression port is fixedly connected to the valve sleeve. The outer ring of the outer shell is provided with an outer shell sealing ring, and the outer ring of the valve sleeve is provided with a valve sleeve sealing ring.

[0015] The diaphragm type air spring stiffness valve is configured to be a structure capable of switching between an energized state and an unenergized state.

[0016] The present invention has a simple structure and reliable control. While ensuring good sealing performance during the movement of the valve core, it can significantly reduce friction resistance, making the solenoid valve move more smoothly. The control method and working principle of the diaphragm air spring stiffness valve are as follows:

[0017] S1. When the diaphragm-type air spring stiffness valve is in the energized state: the magnetic core overcomes the combined force of the main spring and the buffer spring under the action of the electromagnetic force, and is attracted toward the front yoke sleeve, and the valve core sub-assembly is driven by the push rod to move toward the valve sleeve until it is tightly sealed against the valve port, thereby cutting off the connection between the main air chamber and the auxiliary air chamber of the air spring, and the stiffness of the diaphragm-type air spring stiffness valve increases. At this time, the diaphragm is deformed by force, but because the outer protrusion and the central hole of the diaphragm are always in a state of compression and deformation, the upper and lower chambers of the diaphragm are always isolated, that is, the main air chamber and the auxiliary air chamber of the air spring will not be connected by air. At the same time, the pressure of the auxiliary air chamber enters the upper chamber of the diaphragm through the pressure balance hole in the center of the push rod. As long as the effective area of ​​the diaphragm and the effective area of ​​the valve port are designed to be equivalent, the valve core sub-assembly can meet the pressure balance condition, and the sealing state of the valve port will not be disturbed by air pressure changes, and the sealing is reliable.

[0018] S2. When the diaphragm air spring stiffness valve is in a power-off state: after power failure, the magnetic core is reset under the action of the main spring, and the push rod drives the valve core sub-assembly to move until the main spring and the buffer spring reach a new force balance; at this time, the valve port is opened, the main chamber and the sub-chamber are connected, and the stiffness of the diaphragm air spring stiffness valve becomes smaller. At this time, the elastic deformation of the diaphragm is restored, and because the valve core sub-assembly is in a pressure balance state at this time, it will not be disturbed by the pressure changes of the main air chamber and the sub-air chamber, so the reset action is stable and reliable.

[0019] The technical solution of the present invention is adopted, and the working principle and beneficial effects are as follows:

[0020] The diaphragm type air spring stiffness valve of the present invention improves the local structure of the stiffness valve to achieve specific beneficial effects. The diaphragm includes a diaphragm outer protrusion and a diaphragm central hard core, the diaphragm outer protrusion and the diaphragm central hard core are an integrated structure, and the middle of the diaphragm central hard core is a center hole for the diaphragm to pass through the push rod for installation. The diaphragm outer protrusion has a certain thickness or diameter. When the diaphragm is installed, specific control is performed, the diaphragm is sleeved on the push rod from the big end side of the push rod through the center hole of the diaphragm central hard core to achieve sleeve, the diaphragm outer protrusion falls into the front yoke sleeve diaphragm groove of the front yoke sleeve, the pressure cover is pressed into the front yoke sleeve and presses the diaphragm outer protrusion, and the pressure plate is pressed on the big end side of the push rod and presses the diaphragm central hard core. In this way, the installation of the diaphragm is reliably achieved through the front yoke sleeve diaphragm groove, the pressure cover, and the pressure plate of the front yoke sleeve. The above structure can reliably achieve the switching of the diaphragm type air spring stiffness valve between the power-on state and the power-off state to achieve the stiffness adjustment change. Specifically, the movement of the magnetic core relative to the push rod can be achieved by energizing or de-energizing the solenoid sub-assembly. When the diaphragm-type air spring stiffness valve is in the energized state: the magnetic core overcomes the combined force of the main spring and the buffer spring under the action of the electromagnetic force, and is attracted toward the front yoke sleeve, and the valve core sub-assembly is driven by the push rod to move toward the valve sleeve until it is tightly sealed against the valve port, cutting off the connection between the main air chamber and the auxiliary air chamber of the air spring, and the stiffness of the diaphragm-type air spring stiffness valve increases; the outer convex part of the diaphragm is compressed and deformed by the pressure cover, and at the same time, the center hole of the diaphragm is stretched and pressed against the push rod, blocking the compressed air P in the main air chamber. 1 enters the upper chamber of the diaphragm; at the same time, the compressed air P2 in the sub-chamber enters the upper chamber of the diaphragm through the pressure balance hole in the center of the push rod, and the valve core sub-assembly is always in a pressure balance state when it is in the sealing position; when the diaphragm air spring stiffness valve is in a power-off state: after power failure, the magnetic core is reset under the action of the main spring, and the push rod drives the valve core sub-assembly to move until the main spring and the buffer spring reach a new force balance; at this time, the valve port is opened, the main chamber and the sub-chamber are connected, and the stiffness of the diaphragm air spring stiffness valve becomes smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following is a brief description of the contents and symbols in the drawings of this specification:

[0022] Figure 1 It is a structural schematic diagram of the diaphragm type air spring stiffness valve of the present invention;

[0023] Figure 2 It is a partial structural schematic diagram of the diaphragm type air spring stiffness valve of the present invention;

[0024] Figure 3 It is a schematic diagram of the working principle of the diaphragm type air spring stiffness valve of the present invention;

[0025] The marks in the attached drawings are as follows: 1, solenoid connector; 2, rear cover plate; 3, housing seal ring; 4, rear yoke sleeve; 5, housing; 6, solenoid sub-assembly; 7, front yoke sleeve; 7-1, front yoke sleeve diaphragm groove; 8, front yoke sleeve seal ring; 9, valve sleeve; 9-1, valve port; 10, valve sleeve seal ring; 11, valve core sub-assembly; 12, pressure plate; 13, diaphragm; 13-1, diaphragm outer protrusion; 13-2, hard core part in the center of diaphragm; 13-3, center hole; 13-A, main air cavity; 13-B, auxiliary air cavity; 13-C, upper chamber of diaphragm; 14, pressure cover; 15, buffer spring; 16, main spring; 17, push rod; 17-1, pressure balance hole; 17-2, big end of push rod; 17-3, convex part of push rod; 17-4, small end of push rod; 18, magnetic core; 19, guide sleeve. DETAILED DESCRIPTION

[0026] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, etc., through the description of the embodiments with reference to the accompanying drawings:

[0027] As attached Figure 1 -Attached Figure 3As shown, the present invention is a diaphragm type air spring stiffness valve, the diaphragm 13 includes a diaphragm outer protrusion 13-1 and a diaphragm center hard core 13-2, the diaphragm 13 is sleeved on the push rod protrusion 17-3 from the side of the push rod big head 17-2 through the center hole 13-3 of the diaphragm center hard core 13-2, the diaphragm outer protrusion 13-1 falls into the front yoke sleeve diaphragm groove 7-1 of the front yoke sleeve 7, the pressure cover 14 is pressed into the front yoke sleeve 7 and presses the diaphragm outer protrusion 13-1, and the pressure plate 12 is pressed into the side of the push rod big head 17-2 and presses the diaphragm center hard core 13-2. The above structure proposes an improved technical solution to the deficiencies in the prior art. When the structure is set, the local structure of the stiffness valve is improved to achieve specific beneficial effects. The diaphragm 13 includes a diaphragm outer protrusion 13-1 and a diaphragm central hard core 13-2. The diaphragm outer protrusion 13-1 and the diaphragm central hard core 13-2 are an integrated structure. The middle of the diaphragm central hard core 13-2 is a center hole 13-3, which is used for the diaphragm to pass through the push rod 17. The diaphragm outer protrusion 13-1 has a certain thickness or diameter. When the diaphragm 13 is installed, specific control is performed. The diaphragm 13 is installed on the push rod 17 from the side of the push rod big head 20 through the center hole 13-3 of the diaphragm central hard core 13-2. The diaphragm outer protrusion 13-1 falls into the front yoke sleeve diaphragm groove 7-1 of the front yoke sleeve 7. The pressure cover 14 is pressed into the front yoke sleeve 7 and presses the diaphragm outer protrusion 13-1. The pressure plate 12 is pressed on the side of the push rod big head 17-2 and presses the diaphragm central hard core 13-2. In this way, the diaphragm can be reliably installed through the front yoke sleeve diaphragm groove 7-1, the pressure cover 14, and the pressure plate 12 of the front yoke sleeve 7. The above structure can reliably switch the diaphragm air spring stiffness valve between the power-on state and the power-off state to achieve the stiffness adjustment. Specifically, the action of the magnetic core 18 relative to the push rod 17 can be achieved by powering on or off the solenoid subassembly 6.When the diaphragm type air spring stiffness valve is in the energized state: the magnetic core body 18 overcomes the combined force of the main spring 16 and the buffer spring 15 under the action of electromagnetic force, and is attracted toward the front yoke sleeve 7, and drives the valve core sub-assembly 11 to move toward the valve sleeve 9 through the push rod 17 until it tightly seals the valve port 9-1, cutting off the connection between the main air chamber 13-A and the auxiliary air chamber 13-B of the air spring, and the stiffness of the diaphragm type air spring stiffness valve increases; the diaphragm outer protrusion 13-1 of the diaphragm 13 is compressed and deformed by the pressure cover 14, and at the same time, the center hole 13-3 of the diaphragm 13 is stretched and pressed against the push rod 17, blocking the compression of the main air chamber 13-A. The air P1 enters the upper chamber 13-C of the diaphragm; at the same time, the compressed air P2 of the sub-chamber 13-B enters the upper chamber 13-C of the diaphragm through the pressure balance hole 17-1 in the center of the push rod 17, and the valve core sub-assembly 11 is always in a pressure balance state when it is in the sealing position; when the diaphragm air spring stiffness valve is in a power-off state: after power-off, the magnetic core 18 is reset under the action of the main spring 16, and the push rod 17 drives the valve core sub-assembly 11 to move until the main spring 16 and the buffer spring 15 reach a new force balance; at this time, the valve port is opened, the main chamber 13-A and the sub-chamber 13-B are connected, and the stiffness of the diaphragm air spring stiffness valve becomes smaller.

[0028] The push rod 17 includes a push rod convex portion 17-3, a push rod big head 17-2 on one side of the push rod convex portion 17-3, a push rod small head 17-4 on the other side of the push rod convex portion 17-3, and the hard core portion 13-2 of the diaphragm is against the push rod convex portion 17-3. In the above structure, the push rod 17 and the push rod convex portion 17-3 are an integrated structure, and the push rod convex portion 17-3 divides the push rod 17 into a push rod big head 17-2 side and a push rod small head 17-4 side. The push rod big head 17-2 side and the push rod small head 17-4 side are used to install different components respectively, and the push rod convex portion 17-3 is located on the push rod small head 17-4 side, which is used to limit the buffer spring 15, and the push rod convex portion 17-3 is located on the push rod big head 17-2 side, which is used to limit the diaphragm 13.

[0029] The buffer spring 15 and the front yoke sleeve 7 are sequentially mounted on the outer ring of the push rod 17 from the side of the push rod small head 17-4, and the buffer spring 15 presses against the push rod convex part 17-3. The valve core subassembly 11 of the diaphragm type air spring stiffness valve is press-fitted on the push rod 17 from the side of the push rod big head 17-4, and the valve core subassembly 11 fits the pressure plate 12. The above structure can reliably realize the limited installation of the diaphragm. During the operation of the push rod 17, the outer convex part 13-1 of the diaphragm is fixed on the front yoke sleeve 7 at a moderate position, and the hard core part 13-2 of the diaphragm moves with the push rod 17.

[0030] The main spring 16 of the diaphragm type air spring stiffness valve is sleeved on the push rod 17 from the side of the push rod small head 17-4, and the magnetic core body 18 is press-fitted on the push rod 17 from the side of the push rod small head 17-4, and the main spring 16 is pressed between the magnetic core body 18 and the front yoke sleeve 7. The guide sleeve 19 of the diaphragm type air spring stiffness valve and the front yoke sleeve 7 are press-fitted and laser welded into one body, and the guide sleeve 19 is located at the outer ring position of the push rod big head 17-2 side of the push rod 17. The outer ring of the magnetic core body 18 and the front yoke sleeve 7 is sleeved with the solenoid sub-assembly 6, and the outer ring of the solenoid sub-assembly 6 is sleeved with the shell 5. The outer ring of the front yoke sleeve 7 is sleeved with the front yoke sleeve sealing ring 8, and the front yoke sleeve sealing ring 8 is located between the front yoke sleeve 7 and the valve sleeve 9. The shell 5 is riveted and compressed to fix the valve sleeve 9, and the outer ring of the shell 5 is provided with a shell sealing ring 3, and the outer ring of the valve sleeve 9 is provided with a valve sleeve sealing ring 10. The above structure is formed by sequentially connecting and assembling the above components to form a diaphragm type air spring stiffness valve with a complete structure.

[0031] The diaphragm type air spring stiffness valve is configured to be switchable between an energized state and an off-power state. The above structure controls the working state of the stiffness valve by energizing or de-energizing.

[0032] The present invention also relates to a diaphragm type air spring stiffness valve control method with simple steps and reliable control. While ensuring good sealing performance during the movement of the valve core, the friction resistance can be significantly reduced, so that the solenoid valve can move more smoothly and improve performance. The control steps of the diaphragm type air spring stiffness valve control method are:

[0033] When the diaphragm type air spring stiffness valve is in the power-on state: the magnetic core body 18 overcomes the combined force of the main spring 16 and the buffer spring 15 under the action of electromagnetic force, and is attracted toward the front yoke sleeve 7, and drives the valve core sub-assembly 11 to move toward the valve sleeve 9 through the push rod 17 until it tightly seals the valve port 9-1, cutting off the connection between the main air chamber 13-A and the auxiliary air chamber 13-B of the air spring, and the stiffness of the diaphragm type air spring stiffness valve increases. At this time, the diaphragm 13 is deformed by force, but because the outer protrusion 13-1 and the central hole 13-3 of the diaphragm are always in a state of compression and deformation, it is ensured that the upper and lower chambers of the diaphragm are always isolated, that is, the main air chamber 13-A and the auxiliary air chamber 13-B of the air spring will not be connected by air. At the same time, the pressure P2 of the auxiliary air chamber enters the upper chamber 13-C of the diaphragm through the pressure balance hole 17-1 in the center of the push rod. It only needs to design the effective area of ​​the diaphragm 13 to be equivalent to the effective area of ​​the valve port 9-1, and the valve core sub-assembly 11 can meet the pressure balance condition. The sealing state of the valve port 9-1 will not be disturbed by the change of air pressure, and the sealing is reliable. S2. When the diaphragm type air spring stiffness valve is in the power-off state: after the power is off, the magnetic core body 18 is reset under the action of the main spring 16, and the push rod 17 drives the valve core sub-assembly 11 to move until the main spring 16 and the buffer spring 15 reach a new force balance; at this time, the valve port 9-1 is opened, the main chamber 13-A and the auxiliary chamber 13-B are connected, and the stiffness of the diaphragm type air spring stiffness valve becomes smaller. At this time, the elastic deformation of the diaphragm 13 is restored, and because the valve core sub-assembly 11 is in a pressure balance state at this time, it will not be disturbed by the pressure changes of the main air chamber 13-A and the auxiliary air chamber 13-B, so the reset action is stable and reliable. The above steps realize corresponding functions based on the structural improvement of the diaphragm air spring stiffness valve of the present invention, and solve the technical problems in the prior art. The diaphragm air spring stiffness valve of the present invention has a simple structure and reliable control, and can achieve pressure balance during the working process of the diaphragm, and can significantly reduce friction resistance while ensuring good sealing performance during the movement of the valve core, so that the solenoid valve can move more smoothly and improve performance.

[0034] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A diaphragm type air spring stiffness valve, characterized in that: The diaphragm (13) comprises a diaphragm outer protrusion (13-1) and a diaphragm central hard core (13-2); the diaphragm (13) is mounted on the push rod protrusion (17-3) from one side of the push rod big end (17-2) through a central hole (13-3) of the diaphragm central hard core (13-2); the diaphragm outer protrusion (13-1) falls into the front yoke sleeve diaphragm groove (7-1) of the front yoke sleeve (7); the pressure cover (14) is press-fitted into the front yoke sleeve (7) and presses the diaphragm outer protrusion (13-1); the pressure plate (12) is press-fitted on one side of the push rod big end (17-2) and presses the diaphragm central hard core (13-2).

2. The diaphragm type air spring stiffness valve according to claim 1, characterized in that: The push rod (17) portion on one side of the push rod convex portion (17-3) of the push rod (17) is the push rod large end (17-2), the push rod (17) portion on the other side of the push rod convex portion (22) is the push rod small end (17-4), and the hard core portion (13-2) in the center of the diaphragm is against the push rod convex portion (17-3).

3. The diaphragm type air spring stiffness valve according to claim 1 or 2, characterized in that: The buffer spring (15) and the front yoke sleeve (7) are sequentially sleeved on the outer ring of the push rod (17) from one side of the push rod small head (17-4), and the buffer spring (15) is pressed against the push rod convex part (17-3).

4. The diaphragm type air spring stiffness valve according to claim 3, characterized in that: The valve core subassembly (11) of the diaphragm type air spring stiffness valve is interference-pressed onto the push rod (17) from one side of the push rod big end (17-2), and the valve core subassembly (11) fits the pressure plate (12).

5. The diaphragm type air spring stiffness valve according to claim 4, characterized in that: The main spring (16) of the diaphragm type air spring stiffness valve is sleeved on the push rod (17) from the side of the push rod small head (17-4), the magnetic core (18) is interference fit on the push rod (17) from the side of the push rod small head (17-4), and the main spring (16) is pressed between the magnetic core (18) and the front yoke sleeve (7).

6. The diaphragm type air spring stiffness valve according to claim 5, characterized in that: The guide sleeve (19) and the front yoke sleeve (7) of the diaphragm type air spring stiffness valve are press-fitted and laser-welded into one body, and the guide sleeve (19) is located at the outer ring position on one side of the push rod small head (17-4) of the push rod (17).

7. The diaphragm type air spring stiffness valve according to claim 6, characterized in that: The outer rings of the guide sleeve (19) and the front yoke sleeve (7) are mounted on the solenoid subassembly (6), and the outer ring of the solenoid subassembly (6) is mounted on the housing (5).

8. The diaphragm type air spring stiffness valve according to claim 7, characterized in that: The front yoke sleeve (7) is sleeved with a front yoke sleeve sealing ring (8) on its outer ring, the front yoke sleeve sealing ring (8) is located between the front yoke sleeve (7) and the valve sleeve (9), the outer shell (5) is riveted and compressed to fix the valve sleeve (9), the outer ring of the outer shell (5) is provided with an outer shell sealing ring (3), and the outer ring of the valve sleeve (9) is provided with a valve sleeve sealing ring (10).

9. The diaphragm type air spring stiffness valve according to claim 1 or 2, characterized in that: The diaphragm type air spring stiffness valve is configured to be a structure capable of switching between an energized state and an unenergized state.

10. The diaphragm type air spring stiffness valve control method of the diaphragm type air spring stiffness valve according to any one of claims 1 to 9, characterized in that: The control steps of the diaphragm type air spring stiffness valve control method are as follows: S1. When the diaphragm type air spring stiffness valve is in the energized state: the magnetic core (18) overcomes the combined force of the main spring (16) and the buffer spring (15) under the action of electromagnetic force, and is attracted toward the front yoke sleeve (7), and drives the valve core sub-assembly (11) to move toward the valve sleeve (9) through the push rod (17) until it tightly seals the valve port (9-1), thereby cutting off the connection between the main air chamber (13-A) and the auxiliary air chamber (13-B) of the air spring, and the stiffness of the diaphragm type air spring stiffness valve increases; at this time, the diaphragm (13) is deformed by force, and due to the convex part of the diaphragm (13-1) and the central hole (13-3) are always in a state of compression and deformation, ensuring that the upper and lower chambers of the diaphragm are always isolated, that is, the main air chamber (13-A) and the auxiliary air chamber (13-B) of the air spring will not be connected by air; at the same time, the pressure (P2) of the auxiliary air chamber (13-B) enters the upper chamber (13-C) of the diaphragm through the pressure balance hole (17-1) in the center of the push rod. As long as the effective area of ​​the diaphragm is equal to the effective area of ​​the valve port, the valve core can meet the pressure balance condition, and the sealing state of the valve port (9-1) will not be disturbed by air pressure changes; S2. When the diaphragm type air spring stiffness valve is in a power-off state: after power failure, the magnetic core (18) is reset under the action of the main spring (16), and the push rod (17) drives the valve core sub-assembly (11) to move until the main spring (16) and the buffer spring (15) reach a new force balance; at this time, the valve port (9-1) is opened, the main chamber (13-A) and the auxiliary chamber (13-B) are connected, and the stiffness of the diaphragm type air spring stiffness valve becomes smaller. At this time, the elastic deformation of the diaphragm (13) is restored, and because the valve core sub-assembly (11) is in a pressure balance state at this time, it will not be disturbed by the pressure changes of the main air chamber (13-A) and the auxiliary air chamber (13-B).

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