Large-caliber two-way normally-closed electromagnetic valve for air compressor

Abstract

The utility model relates to a large-caliber two-way normally-closed electromagnetic valve for an air compressor, which comprises a main valve body, a pilot electromagnetic valve body arranged on the main valve body, a piston upper cavity arranged in the pilot electromagnetic valve body, a piston arranged in the piston upper cavity, a piston return spring sleeved on the piston, and a piston guide rod connected with the bottom of the piston. The top of the piston is connected with a pilot electromagnetic valve movable iron core, a pilot electromagnetic valve movable iron core sealing piece is embedded in the bottom of the pilot electromagnetic valve movable iron core, the pilot electromagnetic valve movable iron core is sleeved with a movable iron core reset spring, the upper portion of the pilot electromagnetic valve movable iron core is arranged in an electromagnetic valve coil, the electromagnetic valve coil is of a double-sealing structure, and first sealing rings are arranged on the upper portion and the lower portion of the electromagnetic valve coil respectively. The air compressor sealing device is good in sealing effect, flexible in piston operation, high in applicability and capable of meeting control requirements of a conventional air compressor.

Description

Technical Field

[0001] This utility model applies to solenoid valves for screw air compressors, and in particular to a large-diameter dual normally closed solenoid valve for air compressors. Background Technology

[0002] Solenoid valves are key control actuators of screw air compressors and an important component of the control system. Their main function is to control the opening and closing of the air or oil circuit of the air compressor through electrical signals, thereby controlling the normal operation of the air compressor.

[0003] Currently, conventional piston-type pilot-operated large-diameter solenoid valves have two types of pistons: one type only installs a PTFE guide ring and has no sealing structure. The flow rate of the medium that should be controllable when entering the pilot solenoid valve control port from the piston throttling orifice is now partially uncontrollable due to the gap between the guide rings around the piston. When the solenoid valve is energized, the flow rate of the medium entering the control port is more than the flow rate of the exhaust port, causing the solenoid valve main valve to fail to open normally. The other type uses an O-ring seal, which has high operating resistance and poor flexibility, resulting in a higher initial opening pressure.

[0004] Conventional piston-type pilot solenoid valves have a short piston guide distance, which can easily cause deviation when the medium pressure is uneven, leading to piston jamming and the risk of occasional failure of the solenoid valve to open and close normally.

[0005] Because screw air compressors operate in harsh environments with high temperatures and condensation, conventional solenoid valve coils, which have an IP65 waterproof rating, are prone to short-circuiting and burning out due to condensation entering the coil, causing the solenoid valve to fail. Summary of the Invention

[0006] The purpose of this utility model is to overcome the above-mentioned shortcomings and provide a large-diameter dual normally closed solenoid valve for air compressors.

[0007] The purpose of this utility model is achieved through the following technical solution: A large-diameter dual normally closed solenoid valve for an air compressor includes a main valve body, a pilot solenoid valve body on the main valve body, a piston upper chamber in the pilot solenoid valve body, a piston in the piston upper chamber, a piston return spring on the piston, a piston guide rod connected to the bottom of the piston, a pilot solenoid valve moving iron core connected to the top of the piston, a pilot solenoid valve moving iron core seal embedded at the bottom of the pilot solenoid valve moving iron core, a moving iron core return spring on the pilot solenoid valve moving iron core, and the upper part of the pilot solenoid valve moving iron core is set in the solenoid valve coil. The solenoid valve coil adopts a double sealing structure, that is, a first sealing ring is provided at both the upper and lower parts.

[0008] A further improvement of this utility model is that the piston is provided with a piston exhaust port.

[0009] A further improvement of this utility model is that the piston is provided with a piston throttling orifice, so that the upper chamber of the piston is connected to the outside.

[0010] A further improvement of this utility model is that the piston adopts a dynamic sealing structure, that is, the piston is provided with a guide ring and a Y-shaped ring.

[0011] A further improvement of this utility model is that the piston's sealing element is a press-fit sealing ring structure.

[0012] A further improvement of this utility model is that: the piston guide rod extends to the bottom of the main valve body, and an oil-free bushing is provided between the main valve body and the piston guide rod.

[0013] A further improvement of this utility model is that a second sealing ring is provided between the main valve body and the pilot solenoid valve body.

[0014] The advantages of this utility model compared with the prior art are as follows:

[0015] 1. The piston adopts a double-guide structure, that is, the piston guide rod extends to the bottom surface of the valve body, and the bottom of the valve body is equipped with an oil-free bushing, which ensures the concentricity of the piston and allows for flexible up and down movement. This solves the problem of solenoid valve failure caused by jamming due to uneven force on the piston.

[0016] 2. The piston body adopts a dynamic sealing method using guide rings and Y-rings, which reduces friction during operation, ensures reliable sealing, and prevents leakage from affecting control.

[0017] 3. The piston seal adopts a special-shaped ring press-fit structure, which has a good sealing effect, stable performance, and long service life, solving the problem of poor sealing and leakage under low pressure when using PTFE seals in conventional piston solenoid valves.

[0018] 4. The solenoid valve coil is designed with a double sealing ring assembly structure, and the waterproof rating has been upgraded from the original IP65 to IP67, which solves the problem of coil burnout caused by air compressor condensate entering the coil and reduces the customer's operation and maintenance costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the valve core in the closed state of this utility model;

[0020] The following numbers are used in the diagram: 1-Main valve body, 2-Pilot solenoid valve body, 3-Piston upper chamber, 4-Piston, 5-Piston return spring, 6-Piston guide rod, 7-Oil-free bushing, 8-Pilot solenoid valve moving iron core seal, 9-Moving iron core return spring, 10-Solenoid valve coil, 11-First sealing ring, 12-Piston exhaust port, 13-Piston throttling orifice, 14-Guide ring, 15-Y-ring, 16-Sealing ring press-fit structure, 17-Oil-free bushing, 18-Second sealing ring, 19-Solenoid valve inlet, 20-Solenoid valve outlet. Detailed Implementation

[0021] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0022] The figure illustrates a specific embodiment of a large-diameter dual normally closed solenoid valve for air compressors according to this utility model: It includes a main valve body 1, which is made of cast aluminum with a hard anodized surface, making it wear-resistant, corrosion-resistant, and with stable and reliable performance. It is widely applicable to oil-injected screw air compressors or water-lubricated screw air compressors. A pilot solenoid valve body 2 is mounted on the main valve body 1, and a second sealing ring 18 is provided between the main valve body 1 and the pilot solenoid valve body 2. A piston upper chamber 3 is provided in the pilot solenoid valve body 2, and a piston 4 is mounted in the piston upper chamber 3. The piston 4 has a piston exhaust port 12 and a piston throttling orifice 13, allowing the piston upper chamber 3 to communicate with the outside. A piston return spring 5 is fitted on the piston 4. The piston 4 adopts a dynamic sealing structure, i.e., a guide ring 14 and a Y-ring 15 are provided on the piston 4, resulting in low friction, reliable sealing, and minimal leakage affecting control. The sealing element of the piston 4 is a press-fit sealing ring structure 16, providing good sealing effect and stable performance. With a long service life, it solves the problem of poor sealing and leakage under low pressure in conventional piston-type solenoid valves using PTFE seals. The bottom of piston 4 is connected to piston guide rod 6, which extends to the bottom of main valve body 1. An oil-free bushing 17 is provided between main valve body 1 and piston guide rod 6 to ensure concentricity of the piston and flexible up and down movement, solving the problem of solenoid valve failure caused by jamming due to uneven piston force and tilt. The top of piston 4 is connected to pilot solenoid valve moving iron core 7. The bottom of pilot solenoid valve moving iron core 7 is embedded with pilot solenoid valve moving iron core seal 8. A moving iron core return spring 9 is sleeved on pilot solenoid valve moving iron core 7. The upper part of pilot solenoid valve moving iron core 7 is set in solenoid valve coil 10. Solenoid valve coil 10 adopts a double sealing structure, that is, a first sealing ring 11 is provided at both the top and bottom. The waterproof rating is improved from the original IP65 to IP67, solving the problem of coil burnout caused by air compressor condensate entering the coil, and reducing the customer's operation and maintenance costs.

[0023] The working principle of this utility model:

[0024] Initial state of the solenoid valve: Piston 4 is closed under the action of piston return spring 5. Pilot solenoid valve moving iron core 7 is in contact with piston exhaust port 12 and closed. Medium such as compressed air enters from solenoid valve inlet 19 and enters piston upper chamber 3 through piston throttling orifice 13. Piston 4 keeps the main valve passage closed under the back pressure of piston upper chamber 3. After solenoid valve coil 10 is energized, pilot solenoid valve moving iron core 7 is attracted and moves upward under the action of magnetic attraction. Piston exhaust port 12 opens and piston upper chamber 3 begins to depressurize. Piston 4 overcomes spring force and moves upward under the action of medium pressure. Solenoid valve main valve passage opens and medium flows out from solenoid valve outlet 20. After solenoid valve coil 10 is de-energized, pilot solenoid valve moving iron core 7 moves downward under the action of moving iron core return spring 9. Piston exhaust port 12 closes. Piston upper chamber 3 generates back pressure and moves downward, restoring the main channel seal and shutting off solenoid valve outlet 20.

[0025] When the solenoid valve coil receives a control signal from the air compressor controller, the solenoid valve performs opening and closing actions, controlling the air compressor's intake valve to open or close. When the pressure has not reached the user-set pressure, the intake valve opens; when the pressure reaches the user-set pressure, the intake valve closes and begins unloading, reducing motor load, lowering energy consumption, and improving system efficiency. For venting, it quickly vents when the pressure line is overpressurized, preventing abnormal pressure increases and providing overpressure protection. Large-diameter solenoid valves can operate at pressures up to 16 bar, offering strong applicability and meeting the control needs of conventional air compressors.

[0026] The applicant further declares that while the above embodiments illustrate the implementation method and apparatus structure of this utility model, this utility model is not limited to the above-described embodiments, meaning that this utility model must rely on the above methods and structures to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions for the selected implementation methods, additions of steps, and selection of specific methods all fall within the protection and disclosure scope of this utility model.

[0027] This utility model is not limited to the above-described embodiments. All methods that use similar structures and methods to achieve the purpose of this utility model are within the protection scope of this utility model.

Claims

1. A large-diameter dual normally closed solenoid valve for an air compressor, comprising a main valve body (1), wherein a pilot solenoid valve body (2) is provided on the main valve body (1), characterized in that: The pilot solenoid valve body (2) is provided with a piston upper chamber (3), and a piston (4) is provided in the piston upper chamber (3). A piston return spring (5) is fitted on the piston (4). The bottom of the piston (4) is connected to the piston guide rod (6). The top of the piston (4) is connected to the pilot solenoid valve moving iron core (7). The bottom of the pilot solenoid valve moving iron core (7) is embedded with a pilot solenoid valve moving iron core seal (8). A moving iron core return spring (9) is fitted on the pilot solenoid valve moving iron core (7). The upper part of the pilot solenoid valve moving iron core (7) is set in the solenoid valve coil (10). The solenoid valve coil (10) adopts a double sealing structure, that is, the upper and lower parts are provided with a first sealing ring (11).

2. The large-diameter dual normally closed solenoid valve for an air compressor according to claim 1, characterized in that: The piston (4) is provided with a piston exhaust port (12).

3. The large-diameter dual normally closed solenoid valve for an air compressor according to claim 1, characterized in that: The piston (4) is provided with a piston throttling orifice (13) so that the upper chamber (3) of the piston is connected to the outside.

4. The large-diameter dual normally closed solenoid valve for an air compressor according to claim 1, characterized in that: The piston (4) adopts a dynamic sealing structure, that is, the piston (4) is provided with a guide ring (14) and a Y-ring (15).

5. The large-diameter dual normally closed solenoid valve for an air compressor according to claim 1, characterized in that: The piston (4) has a sealing ring press-fit structure (16).

6. The large-diameter dual normally closed solenoid valve for an air compressor according to claim 1, characterized in that: The piston guide rod (6) extends to the bottom of the main valve body (1), and an oilless bushing (17) is provided between the main valve body (1) and the piston guide rod (6).

7. The large-diameter dual normally closed solenoid valve for an air compressor according to claim 1, characterized in that: A second sealing ring (18) is provided between the main valve body (1) and the pilot solenoid valve body (2).

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