Liquid leakage prevention structure of electro-hydraulic servo valve

Abstract

The utility model relates to a liquid leakage prevention structure of an electro-hydraulic servo valve. The liquid leakage prevention structure comprises a torque motor, an upper cover, an upper cover rubber ring, a shell, a connector, a plastic pressing block and a connector rubber ring. A boss is designed on the upper surface of the shell, the torque motor is installed on the boss face of the shell and sealed through a sealing ring, the side face of the boss of the shell and the upper cover are sealed through an upper cover rubber ring, the shell is provided with a lead hole, and a connector is installed in the lead hole of the shell and limited through the end of a plastic pressing block. The connector is provided with a rubber ring groove, and the connector rubber ring is installed in the connector rubber ring groove, thereby achieving the sealing between the connector and the housing. According to the designed liquid leakage prevention structure, when the electro-hydraulic servo valve is used along with an engine, fuel oil is sealed in the upper cover after the spring pipe is accidentally broken, the strength of the connector and the strength of the upper cover are high, and the pressure resistance effect of oil liquid under the pressure of 21 MPa can be achieved; the coil lead is welded on the connector, the connector is provided with the leading-out wire, and when the leading-out wire is accidentally crushed, only the connector needs to be replaced.

Description

Technical Field

[0001] The utility model belongs to the technical field of fuel valves, in particular to a liquid leakage prevention structure of an electro-hydraulic servo valve. Background Art

[0002] The electro-hydraulic servo valves used in engines have high safety requirements. Engine lifespans are typically over a thousand hours. They are subject to vibration, shock, and acceleration loads, as well as pressure pulsations in the fuel supply system that resonate with the valve (whistling), potentially leading to rupture of the valve's spring tube. Therefore, during operation, the valve must be protected from fuel leakage and engine fire. In explosive environments caused by explosive mixtures, the valve's components must remain structurally intact, preventing explosions and ignition of combustible gases.

[0003] Because the cross-sectional area and length of the electro-hydraulic servo valve's coil leads are determined based on system usage, lifting the coil leads during assembly or transportation directly impacts the valve's gravity, potentially causing the coil to become conductive or disconnected. Contact between the coil and the housing could cause an engine fire, while a disconnected coil could render the servo valve uncontrollable. Furthermore, a disconnected coil requires disassembly of the torque motor and re-commissioning, making repairs inconvenient. Utility Model Content

[0004] Purpose of the utility model: In order to solve the above problems, the purpose of the utility model is to provide a leakage-proof structure of an electro-hydraulic servo valve, which uses connectors, plastic pressure blocks and connector rubber rings in the lead holes of the shell to achieve internal sealing of the upper cover.

[0005] Technical solution: To achieve the above-mentioned purpose, the electro-hydraulic servo valve with a leak-proof structure provided by the present invention adopts the following technical solution:

[0006] The anti-leakage structure of the electro-hydraulic servo valve includes: a torque motor, an upper cover, an upper cover rubber ring, a housing, a connector, a plastic pressure block, and a connector rubber ring;

[0007] The upper surface of the shell is designed with a boss, and the torque motor is mounted on the boss surface of the shell and sealed by a sealing ring. The side of the shell boss and the upper cover are sealed by the upper cover rubber ring. The shell is provided with a lead hole, and the connector is mounted in the lead hole of the shell and is limited by the end of the plastic pressing block; the connector is provided with a rubber ring groove, and the connector rubber ring is mounted on the connector rubber ring groove to achieve sealing between the connector and the shell.

[0008] Furthermore, the shell frame of the connector is made of stainless steel, the head is provided with 4 solder cups, the tail is provided with four lead wires, and the connector is made by glass sintering.

[0009] Furthermore, the four solder cups on the connector head are exposed from the lead holes of the housing, and the coil leads are soldered to the connector solder cups.

[0010] Furthermore, the material of the plastic pressing block is fluoroplastic, and the combined length of the plastic pressing block and the connector is 10 μm to 50 μm longer than the length of the lead hole of the housing, so that the connector can be axially positioned.

[0011] Furthermore, the outer circle of the plastic pressing block is interference-fitted with the lead hole of the housing, and the interference is 5 μm to 15 μm.

[0012] Furthermore, the shell material is 9Cr18Mo, which has high strength.

[0013] The beneficial technical effects of the utility model are as follows: compared with the existing electro-hydraulic servo valve, the utility model is designed with a leak-proof structure. When the electro-hydraulic servo valve is used with the engine, the fuel will be sealed inside the upper cover after the spring tube is accidentally broken. The strength of the connector and the upper cover is high, which can meet the pressure resistance of the oil under 21MPa. It will not leak due to high-pressure fuel, and prevent the engine from catching fire due to leakage of oil inside the electro-hydraulic servo valve, which has higher safety. The coil lead is welded on the connector, and the connector is provided with a lead wire. When the lead wire is accidentally crushed, it only needs to be Replacing the connector and re-welding the coil leads to the new connector is simple. There is no need to disassemble the torque motor to replace the coil and re-debug the electro-hydraulic servo valve, which facilitates maintenance and reduces costs. The leads of the connector can withstand a tensile force of 20N, which can prevent them from breaking or insulation resistance failure during transportation and assembly. The cross-sectional area and length of the connector lead wires can be designed according to requirements. When the cross-sectional area and length requirements of the host lead wires change, there is no need to redesign the coil. Only the cross-sectional area and length of the connector lead wires need to be changed, which has a high degree of commonality and serialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the utility model;

[0015] Among them, 1 torque motor, 2 upper cover, 3 coil lead, 4 connector, 5 upper cover rubber ring, 6 connector rubber ring, 7 shell, 8 plastic block.

[0016] Figure 2 This is the shell structure diagram of the utility model

[0017] Among them, 7-1 is the shell boss, and 7-2 is the shell lead hole. DETAILED DESCRIPTION

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings or specific implementation cases. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described and these examples should not be understood as being limited to the examples set forth herein. On the contrary, describing these examples makes the positive effects of the present invention more apparent, and any parts not detailed herein are considered to be well-known techniques or conventional technical means in the art.

[0019] See attached Figure 1 The specific embodiment of the utility model provides a leakage-proof structure of an electro-hydraulic servo valve, comprising: a torque motor 1, an upper cover 2, a coil lead 3, a connector 4, an upper cover rubber ring 5, a connector rubber ring 6, a housing 7, and a plastic pressing block 8;

[0020] The core design of the present invention lies in that the shell structure is different from the conventional servo valve shell structure. In the servo valve structure designed in the present invention, a boss is designed on the upper surface of the shell 7, and the torque motor 1 is mounted on the boss surface of the shell 7, and sealing is achieved by a rubber ring. The side surface of the boss of the shell 7 and the upper cover are sealed by the upper cover rubber ring 5. The shell 7 is provided with a lead hole, and the connector 4 is mounted in the lead hole of the shell 7.

[0021] Based on the above-mentioned servo valve structural design, the outer shell frame of the connector 4 is made of stainless steel, with four welding cups at the head and four lead wires at the tail. The connector 7 is made of glass sintering, which has the characteristics of being resistant to high-pressure oil without damage. The lead wires of the connector can withstand a tensile force of more than 20N, which is much greater than 1.5 times the gravity of the electro-hydraulic servo valve itself, preventing it from breaking or insulation resistance out-of-tolerance failure during transportation and assembly.

[0022] On the basis of the above-mentioned servo valve structure design, a rubber ring groove is provided on the connector 4 , and the connector rubber ring 6 is installed on the connector rubber ring groove to achieve sealing between the connector 4 and the housing 7 .

[0023] Based on the above-mentioned servo valve structural design, the four welding cups at the head of the connector 4 are exposed to the lead hole of the shell 7, and the coil lead 3 is welded to the welding cup of the connector 4. If the lead wire is damaged during the use of the servo valve, only the connector 4 needs to be replaced, and there is no need to disassemble the torque motor to replace the coil, which facilitates the maintenance of the electro-hydraulic servo valve.

[0024] Based on the above-mentioned servo valve structural design, the combined length of the plastic pressing block 8 and the connector 4 is 10μm to 50μm longer than the length of the lead hole of the housing 7, which can be used to axially position the connector 4. The material of the plastic pressing block 8 is fluoroplastic. When the electro-hydraulic servo valve is installed on the housing of the control device, the plastic pressing block 8 is made of a relatively soft material, and the plastic pressing block 8 is compressed without damaging the surface of the control device housing.

[0025] Based on the above servo valve structure design, the outer circle of the plastic pressing block 8 is interference fit with the lead hole of the housing 7, and the interference is 5μm to 15μm to prevent the connector 4 from falling when picking up the electro-hydraulic servo valve, causing the solder joint to loosen.

[0026] Based on the above servo valve structure design, the housing material 7 is 9Cr18Mo, which has high strength and can withstand a pressure of 21 MPa.

[0027] The above specific implementation methods or cases are only used to explain the technical solutions of the utility model and are not intended to limit the present application. Any parts not described in detail are regarded as conventional technical means or common knowledge in the field. It can be understood by ordinary technicians in this field that: based on the design concept of the present application, it should be possible to adaptively modify the technical solutions recorded in the aforementioned implementation methods, or to replace some or all of the technical features therein by equivalents. These modifications, equivalent replacements, and adaptively improved technical solutions do not depart from the technical essence of the utility model and should all be covered by the protection scope of the present application.

Claims

1. The anti-leakage structure of the electro-hydraulic servo valve is characterized by: include: Torque motor, upper cover, upper cover rubber ring, housing, connector, plastic pressing block, connector rubber ring; The upper surface of the shell is designed with a boss, and the torque motor is mounted on the boss surface of the shell and sealed by a sealing ring. The side of the shell boss and the upper cover are sealed by the upper cover rubber ring. The shell is provided with a lead hole, and the connector is mounted in the lead hole of the shell and is limited by the end of the plastic pressing block; the connector is provided with a rubber ring groove, and the connector rubber ring is mounted on the connector rubber ring groove to achieve sealing between the connector and the shell.

2. The anti-leakage structure of the electro-hydraulic servo valve according to claim 1, characterized in that: The shell frame of the connector is made of stainless steel, the head is provided with 4 welding cups, the tail is provided with four lead wires, and the connector is made by glass sintering.

3. The anti-leakage structure of the electro-hydraulic servo valve according to claim 2, characterized in that: The four solder cups on the connector head are exposed from the lead holes of the shell, and the coil leads are welded to the connector solder cups.

4. The anti-leakage structure of the electro-hydraulic servo valve according to claim 1, characterized in that: The material of the plastic pressing block is fluoroplastic. The combined length of the plastic pressing block and the connector is 10 μm to 50 μm longer than the length of the lead hole of the housing, and the connector can be axially positioned.

5. The anti-leakage structure of the electro-hydraulic servo valve according to claim 4, characterized in that: The outer circle of the plastic pressing block is interference-fitted with the lead hole of the shell, and the interference is 5 μm to 15 μm.

6. The anti-leakage structure of the electro-hydraulic servo valve according to claim 1, characterized in that: The shell is made of 9Cr18Mo.

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