Electromagnetic proportional follow-up valve for diaphragm compressor

Abstract

The utility model discloses an electromagnetic proportional follow-up valve for a diaphragm compressor, which relates to the technical field of follow-up valves and comprises an upper valve body, a lower valve body and a proportional electromagnet component, the upper valve body is arranged at the top of the lower valve body, the proportional electromagnet component is arranged at the top of the upper valve body, a push rod is slidably connected in the upper valve body, and an upper spring seat is arranged at the lower end of the push rod. A lower spring seat is arranged at the upper end of the valve core; a pressure spring is arranged between the upper spring seat and the lower spring seat; plunger holes are formed in the valve core and the lower spring seat; an oil distribution ring is mounted on the inner wall of the lower valve body; a valve seat is arranged at the top of the connector, and oil drainage holes are formed in the connector and the valve seat. Opening and closing of the follow-up valve under the high-pressure or large-flow working condition can be controlled through small electromagnetic force, meanwhile, the closing resistance of the valve element is small, the closing response speed is higher, and the control requirement of the diaphragm compressor under the extreme working condition is met.

Description

Technical Field

[0001] This utility model relates to the technical field of follower valves, specifically to an electromagnetic proportional follower valve for a diaphragm compressor. Background Technology

[0002] A diaphragm compressor is a positive displacement compressor. It works by using the reciprocating motion of a piston to push hydraulic oil in the diaphragm chamber of the cylinder head. This hydraulic oil then pushes the diaphragm, which in turn drives the gas to complete the intake, compression, and exhaust processes. In the design of a diaphragm compressor, the diaphragm chamber volume is slightly larger than the piston's stroke volume. This ensures that when the piston reaches bottom dead center, an oil pad remains between the diaphragm and the oil side, preventing cylinder knocking during intake.

[0003] Because hydraulic oil inevitably leaks from sealing parts such as pistons and cylinder liners during operation, diaphragm compressors are equipped with oil replenishment lines to supply oil to the oil chamber. Since it is difficult to match the amount of oil replenished exactly with the amount of leakage, an overflow line is also generally provided to allow excess oil to overflow and prevent overpressure. The oil replenishment and overflow systems are the most basic oil circuit configurations for diaphragm compressors.

[0004] Typically, diaphragm compressors use spring-operated direct-acting relief valves in their oil overflow systems for pressure regulation, controlling the maximum pressure of the hydraulic oil in the diaphragm chamber to approximately 1.1 times the discharge pressure. If the discharge pressure changes, traditional spring-operated relief valves cannot adjust accordingly, and in most cases, they are replaced with follow-up valves. Existing follow-up valves are structured like a small cylinder head. Their principle is to introduce gas into one side of the control piston or diaphragm, while the other side is connected to high-pressure oil. Through a suitable area ratio or with the assistance of spring force, the gas pressure controls the opening and closing of the main valve, thus completing the oil overflow function.

[0005] Traditional follow-up valves require pneumatic pressure for control, which presents a risk of oil-gas mixing. This typically necessitates the addition of anti-oil-gas mixing structures and leak monitoring systems. Consequently, the gas pressure pipeline, leak monitoring system, and anti-oil-gas mixing structure significantly increase the system's complexity and cost. To address this, electromagnetic follow-up valves, which utilize electromagnetic force to control the opening and closing of the main valve, have emerged in recent years, attempting to resolve the oil-gas mixing risk and the issue of pressure regulation.

[0006] The typical structure of existing electromagnetic follow-up valves is that proposed in Chinese Patent Publication No. CN113982894B. This valve uses a proportional electromagnet to push a spring, which in turn pushes the valve core to close it on the valve seat. The valve seat and bottom channel form a pressure chamber, while the valve core, valve body, and piston form an overflow chamber. When the product of the hydraulic oil pressure P in the pressure chamber and the overflow channel area A is greater than the proportional electromagnet thrust F, the valve core opens, completing the overflow. The electromagnetic thrust F can be controlled by adjusting the proportional electromagnet current, thus controlling the valve core opening pressure. However, this structure has limitations:

[0007] 1. When overflow is required under high pressure or high flow conditions, the product of hydraulic oil pressure P and overflow channel area A is often very large, while conventional proportional electromagnets can only provide a thrust of tens of Newtons, which limits their use.

[0008] 2. When closed, the valve core moves in the opposite direction to the fluid movement. The valve core of this structure closes more slowly than the structure that moves in the same direction. In extreme cases, this can cause the follow-up valve to release too much hydraulic oil, causing the compressor to malfunction. Summary of the Invention

[0009] The purpose of this invention is to provide an electromagnetic proportional follower valve for diaphragm compressors to overcome the above-mentioned defects in the prior art.

[0010] An electromagnetic proportional follower valve for a diaphragm compressor includes an upper valve body, a lower valve body, and a proportional electromagnet component. The upper valve body is located on top of the lower valve body, and the proportional electromagnet component is located on top of the upper valve body. A push rod is slidably connected in the upper valve body, and an upper spring seat is provided at the lower end of the push rod. A valve core is slidably connected in the lower valve body, and a lower spring seat is provided at the upper end of the valve core. The upper spring seat and the lower spring seat are connected by a pressure spring. A plunger hole is provided in the valve core and the lower spring seat. An oil distribution ring is installed on the inner wall of the lower valve body, and the oil distribution ring has several oil holes. An oil inlet hole communicating with the oil holes is provided on the side of the lower valve body. A connector is installed at the bottom of the lower valve body, and a valve seat is provided at the top of the connector. An oil drain hole is provided in the connector and the valve seat.

[0011] Preferably, the lower end of the valve core has a tapered cylindrical structure.

[0012] Preferably, the drain hole on the valve seat mates with the lower end of the valve core.

[0013] Preferably, the upper valve body and the lower valve body are threaded together, and a sealing ring is installed between the upper valve body and the lower valve body.

[0014] Preferably, the push rod is provided with a plurality of sealing rings.

[0015] Preferably, a sealing gasket is provided between the connector and the lower valve body.

[0016] The beneficial effects achieved by this utility model are as follows:

[0017] This application can control the opening and closing of the follow-up valve under high pressure or high flow conditions with a small electromagnetic force, while the valve core has low closing resistance and faster closing response speed, so as to meet the control requirements of diaphragm compressor under extreme conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall internal structure of this utility model.

[0019] Figure 2 This is a schematic diagram of the lower valve body and connector of this utility model.

[0020] In the diagram, 1. Upper valve body; 11. Sealing ring one; 2. Lower valve body; 21. Oil inlet; 3. Proportional electromagnet component; 4. Push rod; 41. Sealing ring two; 42. Upper spring seat; 5. Valve core; 51. Lower spring seat; 52. Piston hole; 6. Pressure spring; 7. Oil distribution ring; 8. Connector; 81. Sealing gasket; 82. Valve seat; 83. Oil drain hole. Detailed Implementation

[0021] The following detailed description of the embodiments, with reference to the accompanying drawings, will further illustrate the specific implementation of this utility model, in order to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the concept and technical solution of this utility model.

[0022] like Figure 1 As shown, this utility model provides an electromagnetic proportional follow-up valve for a diaphragm compressor, including an upper valve body 1, a lower valve body 2, and a proportional electromagnet component 3. The proportional electromagnet component 3 is a conventional electrical control element and will not be explained further.

[0023] The upper valve body 1 is located on top of the lower valve body 2. The upper valve body 1 and the lower valve body 2 are threaded together, and a sealing ring 11 is installed between the upper valve body 1 and the lower valve body 2. The proportional electromagnet component 3 is located on top of the upper valve body 1. A push rod 4 is slidably connected in the upper valve body 1. Several sealing rings 41 are provided on the push rod 4. An upper spring seat 42 is provided at the lower end of the push rod 4. A valve core 5 is slidably connected in the lower valve body 2. The lower end of the valve core 5 is a tapered column structure. A lower spring seat 51 is provided at the upper end of the valve core 5. The upper spring seat 42 and the lower spring seat 51 are connected by a pressure spring 6. A plunger hole 52 is provided in the valve core 5 and the lower spring seat 51.

[0024] To prevent uneven impact force during hydraulic oil discharge from causing uneven wear or movement jamming of the valve core 5, an oil distribution ring 7 is provided in the high-pressure chamber. The oil distribution ring 7 can evenly distribute the impact of hydraulic oil around the valve core 5. The side of the lower valve body 2 is provided with an oil inlet hole 21 that communicates with the oil hole on the oil distribution ring 7. A connector 8 is installed at the bottom of the lower valve body 2. A sealing gasket 81 is provided between the connector 8 and the lower valve body 2. A valve seat 82 is provided at the top of the connector 8. An oil drain hole 83 is provided in the connector 8 and the valve seat 82. The oil drain hole 83 on the valve seat 82 is matched with the lower end of the valve core 5.

[0025] The lower valve body 2 has a pressure inlet hole 21 on its side, and a movable valve core 5 is installed inside. The movable contact surface between the valve core 5 and the lower valve body 2 is a plunger-coupled seal. The valve core 5, connector 8, valve seat 82, and the interior of the lower valve body 2 form a sealed pressure chamber. Connector 8 is threaded onto the lower valve body 2. Connector 8 has an oil drain hole 83 and an oil drain chamber at its bottom.

[0026] The valve core 5 has a hollow structure with a plunger hole 52 in the middle, which connects the oil discharge port to the spring cavity inside the upper valve body 1. When the high-pressure oil in the pressure chamber enters the spring cavity inside the upper valve body 1 through the gap sealed by the plunger assembly, it will drain through the plunger hole 52 of the valve core 5, thus keeping the spring cavity inside the upper valve body 1 in a pressure-free state. The thrust of the movable armature in the proportional electromagnet component 3 is transmitted to the valve core 5 through the push rod 4, the upper spring seat 42, the pressure spring 6, and the lower spring seat 51, pressing the valve core 5 onto the valve seat 82 to complete the seal.

[0027] like Figure 2 As shown, the plunger sealing area A2 of valve core 5 is larger than the overflow channel area A1. Obviously, valve core 5 will move upward after being subjected to the oil pressure P in the pressure chamber, while valve core 5 is subjected to a downward electromagnetic force F. By controlling the current of the proportional electromagnet, the downward clamping force on valve core 5 can be controlled, while valve core 5 is subjected to the upward thrust of hydraulic oil in the high-pressure chamber. When the electromagnetic force F = P(A2-A1), it is in equilibrium. When the oil pressure P ≥ F / (A2-A1), valve core 5 opens, completing the overflow.

[0028] Compared to traditional electromagnetic follow-up valves, this structure calculates the thrust required to open the valve core 5 by using the difference between the piston sealing area A2 and the overflow channel area A1. Therefore, the overflow channel area A1 can be designed to be larger. As long as the difference between the piston sealing areas A2 and A1 is controlled within a reasonable range, it can be matched with a conventional proportional electromagnet. In contrast, traditional electromagnetic follow-up valves require a much larger electromagnetic force to maintain the same large overflow channel area, while conventional proportional electromagnets can only provide a thrust of tens of Newtons, limiting their use in certain operating conditions.

[0029] On the other hand, the bottom of the valve core 5 in this structure is a hole, and the side of the valve core 5 has an oil inlet hole 21. The direction of movement of the hydraulic oil during overflow is opposite to that of a conventional electromagnetic follower valve. When the valve core 5 of this structure is closed, it moves in the same direction as the hydraulic oil. The valve core 5 does not need to overcome the impact force of the hydraulic oil flow when closing, so the valve core 5 of this structure closes faster. In addition, since the sealing type between the valve core 5 and the lower valve body 2 is a plunger pair seal with no dynamic seal, the resistance when the valve core 5 moves is extremely small, which further accelerates the closing speed of the valve core 5. The rapid closing of the valve core 5 can prevent the follower valve from releasing too much hydraulic oil, thereby preventing the compressor from malfunctioning.

[0030] In summary, this solution avoids the traditional design approach of matching electromagnetic force with the product of hydraulic oil pressure P and overflow channel area A, and the structural feature of valve core 5 with the bottom as the pressure chamber and the side as the discharge port. This solution matches electromagnetic force with the product of the difference between the plunger sealing area A2 and the overflow channel area A1 and the hydraulic oil pressure P. Through valve core 5 with its hollow drain channel and plunger sealing characteristics, the pressure chamber and overflow chamber are inverted, thereby improving the closing speed of valve core 5.

[0031] The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. An electromagnetic proportional servo valve for diaphragm compressor, comprising an upper valve body (1), a lower valve body (2) and a proportional electromagnet component (3), the upper valve body (1) is arranged on the top of the lower valve body (2), the proportional electromagnet component (3) is arranged on the top of the upper valve body (1), characterized in that: A push rod (4) is slidably connected in the upper valve body (1), the lower end of the push rod (4) is provided with an upper spring seat (42), a valve core (5) is slidably connected in the lower valve body (2), the upper end of the valve core (5) is provided with a lower spring seat (51), the upper spring seat (42) and the lower spring seat (51) are connected through a pressure spring (6), the valve core (5) and the lower spring seat (51) are provided with a plunger hole (52), an oil distribution ring (7) is installed on the inner wall of the lower valve body (2), a plurality of oil holes are provided on the oil distribution ring (7), an oil inlet hole (21) is provided on the side of the lower valve body (2) and communicates with the oil holes, a connector (8) is installed at the bottom of the lower valve body (2), the top of the connector (8) is provided with a valve seat (82), a drain hole (83) is provided in the connector (8) and the valve seat (82).

2. The electromagnetic proportional servo valve for a diaphragm compressor according to claim 1, characterized in that: The lower end of the valve core (5) is a conical column structure.

3. The electromagnetic proportional servo valve for a diaphragm compressor according to claim 1, characterized in that: The drain hole (83) on the valve seat (82) cooperates with the lower end of the valve core (5).

4. The electromagnetic proportional servo valve for a diaphragm compressor according to claim 1, characterized in that: The upper valve body (1) is threadedly connected with the lower valve body (2), and a sealing ring I (11) is installed between the upper valve body (1) and the lower valve body (2).

5. The electromagnetic proportional servo valve for a diaphragm compressor according to claim 1, characterized in that: A plurality of sealing rings II (41) are provided on the push rod (4).

6. The electromagnetic proportional servo valve for a diaphragm compressor according to claim 1, characterized in that: A sealing gasket (81) is provided between the connector (8) and the lower valve body (2).

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