Sealing structure of electronic expansion valve

Abstract

The utility model relates to the technical field of sealing structures, in particular to a sealing structure of an electronic expansion valve, which has lower friction force, better overcomes torsion generated during installation, eliminates internal stress of a sealing ring, reduces the condition of poor sealing caused by flash, simultaneously performs axial compression and radial compression, and improves the sealing performance of the electronic expansion valve. The contact area of the sealing surface is widened, and the sealing effect is enhanced; comprising a sealing ring, a valve element and a coil, the outer side wall of the valve element is sleeved with the sealing ring, and the coil is installed on the upper portion of the valve element; the sealing ring comprises a lip edge, an axial support and a radial support, and the lip edge, the axial support and the radial support form the shape of the sealing ring.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing structures, in particular to a sealing structure of an electronic expansion valve. Background Art

[0002] The electronic expansion valve is composed of a coil and a valve core. In order to protect the internal plates of the coil from being corroded by the external environment, a sealing ring is often used on the valve core for sealing to isolate it from interference from external factors.

[0003] However, due to the characteristics of the O-ring, it is easy to be twisted and have internal stress when installing the O-ring, which may cause the seal to fail. In addition, due to the injection molding process of the O-ring, flash is easy to appear at the cross section of the O-ring, which can also cause the seal to fail. When installing the coil, a sealed cavity is easy to form inside during the O-ring pressing stage, resulting in air entrapment, making the coil difficult to install. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a sealing structure of an electronic expansion valve with lower friction, which can better overcome the torsion generated during installation, eliminate the internal stress of the sealing ring, reduce the poor sealing caused by flash, and simultaneously perform axial compression and radial compression to widen the contact area of ​​the sealing surface and enhance the sealing effect.

[0005] The utility model discloses a sealing structure of an electronic expansion valve, comprising a sealing ring, a valve core and a coil, wherein the sealing ring is sleeved on the outer wall of the valve core, and the coil is installed on the upper part of the valve core;

[0006] The sealing ring includes a lip, an axial support and a radial support, which form the shape of the sealing ring; when the sealing ring is installed on the valve core and the coil is installed on the valve core, the sealing ring is subjected to axial compression and radial compression at the same time, and the contact surface between the valve core and the coil installation surface becomes wider. This characteristic enables the lip to have the ability to compensate for dimensional tolerance and angular error. During the coil extraction process, the contact form between the lip and the coil installation surface changes from surface sealing to line sealing, so that external impurities are not easy to enter the inner cavity of the coil and do not affect the next use of the sealing ring. The axial support can ensure that the sealing ring will not be twisted during installation, eliminate the internal stress generated during the installation of the sealing ring, and the lip is a single lip seal to ensure that the coil has lower friction during installation;

[0007] When the coil is installed Figure 7position, the lip of the sealing ring begins to enter the coil installation surface, the sealing line begins to form, and the inner cavity of the coil gradually becomes a sealed cavity. When the coil moves downward, according to the Clapham equation PV=nRT, when the inner cavity volume V gradually decreases, the internal pressure P will gradually increase. According to F=P×S, the upward F becomes larger, the installation force of the coil becomes larger, and the downward lip structure will discharge the internal gas when the internal pressure P increases, reduce the internal air pressure, and reduce the installation force of the coil. During the operation of the valve body, the coil will produce temperature rise, the internal gas temperature T rises, the pressure P rises, and part of the gas will be discharged. When the coil temperature returns to normal temperature, the internal pressure P is lower than the external pressure, and there is negative pressure in the coil cavity, which makes it difficult for the coil to fall out. When the external air pressure is higher than the internal air pressure, the contact shape of the lip tip will also change, which will increase the contact stress with the coil installation surface, and the lip and the sealing position fit more closely to better achieve the sealing effect.

[0008] Preferably, the inner side of the axial support is divided into an air avoidance section, a guide section and a support section; the air avoidance section serves to reduce the contact area and reduce the friction generated when the sealing ring is installed, the guide section serves to make the sealing ring fit more easily when subjected to radial force, and the support section serves to axially support the sealing ring.

[0009] Preferably, the radial support is composed of a gap avoidance section and the upper part of the support section of the axial support; the gap avoidance section is thickened to enhance the radial supporting force of the sealing ring, thereby reducing the hardness requirement of the sealing ring in disguise, and structurally, the compression amount of the sealing ring is adjusted by adjusting the thickness of the root to adapt to different working conditions.

[0010] Preferably, the structural design of the lip makes the flash appear on the inner side of the inner lip of the lip tip, thereby eliminating the influence of the flash on the sealing performance.

[0011] Compared with the prior art, the utility model has the following beneficial effects: when the sealing ring is installed on the valve core and the coil is installed on the valve core, the sealing ring is simultaneously subjected to axial compression and radial compression, and the contact surface between the valve core and the coil installation surface becomes wider. This characteristic enables the lip edge to have the ability to compensate for dimensional tolerance and angular error. During the coil extraction process, the contact form between the lip edge and the coil installation surface changes from surface sealing to line sealing, so that foreign matter is not easy to enter the inner cavity of the coil and does not affect the next use of the sealing ring. The axial support can ensure that the sealing ring will not be twisted during installation, and eliminate the internal stress generated during the installation of the sealing ring. The lip edge is a single lip seal, which ensures that the coil has a lower friction force during installation.

[0012] When the coil is installed Figure 7position, the lip of the sealing ring begins to enter the coil installation surface, the sealing line begins to form, and the inner cavity of the coil gradually becomes a sealed cavity. When the coil moves downward, according to the Clapham equation PV=nRT, when the inner cavity volume V gradually decreases, the internal pressure P will gradually increase. According to F=P×S, the upward F becomes larger, the installation force of the coil becomes larger, and the downward lip structure will discharge the internal gas when the internal pressure P increases, reduce the internal air pressure, and reduce the installation force of the coil. During the operation of the valve body, the coil will produce temperature rise, the internal gas temperature T rises, the pressure P rises, and part of the gas will be discharged. When the coil temperature returns to normal temperature, the internal pressure P is lower than the external pressure, and there is negative pressure in the coil cavity, which makes it difficult for the coil to fall out. When the external air pressure is higher than the internal air pressure, the contact shape of the lip tip will also change, which will increase the contact stress with the coil installation surface, and the lip and the sealing position fit more closely to better achieve the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the axonometric structure of the utility model;

[0014] Figure 2 It is a schematic diagram of the partial axonometric structure of the connection between the sealing ring and the valve core;

[0015] Figure 3 It is a schematic diagram of the partial structure of the axonometric view of the connection between the valve core and the coil, etc.;

[0016] Figure 4 It is a schematic diagram of the side view structure of the lip and axial support;

[0017] Figure 5 It is a schematic diagram of the structure of the lip tip and the inner side of the lip from a side view;

[0018] Figure 6 It is a schematic diagram of the side view structure of the air avoidance section and the guide section;

[0019] Figure 7 It is a side view structural diagram of the connection between the sealing ring and the valve core;

[0020] Figure 8 It is a side view structural diagram of the connection between the valve core and the coil, etc.

[0021] Markings in the attached drawings: 1. sealing ring; 2. valve core; 3. coil; 4. lip tip; 5. inner side of lip; 6. air avoidance section; 7. guide section; 8. support section; 11. lip edge; 12. axial support; 13. radial support. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the utility model, the utility model will be described more comprehensively below with reference to the relevant drawings. The utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive.

[0023] Example 1

[0024] like Figures 1 to 8 As shown, a sealing structure of an electronic expansion valve of the utility model comprises a sealing ring 1, a valve core 2 and a coil 3, wherein the sealing ring 1 is sleeved on the outer wall of the valve core 2, and the coil 3 is installed on the upper part of the valve core 2;

[0025] The sealing ring 1 comprises a lip 11, an axial support 12 and a radial support 13, and the lip 11, the axial support 12 and the radial support 13 form the shape of the sealing ring 1;

[0026] like Figure 6 As shown, the inner side of the axial support 12 is divided into a clearance section 6, a guide section 7 and a support section 8;

[0027] In this embodiment, when the sealing ring 1 is installed on the valve core 2 and the coil 3 is installed on the valve core 2, the sealing ring 1 is subjected to axial compression and radial compression at the same time, and the contact surface between the valve core 2 and the installation surface of the coil 3 becomes wider. This characteristic enables the lip 11 to have the ability to compensate for dimensional tolerance and angular error. During the process of pulling out the coil 3, the contact form between the lip 11 and the installation surface of the coil 3 changes from surface sealing to line sealing, so that foreign matter is not easy to enter the inner cavity of the coil 3, and does not affect the next use of the sealing ring 1. The axial support 12 can ensure that the sealing ring 1 will not be twisted during installation, and eliminate the internal stress generated during the installation of the sealing ring 1. The lip 11 is a single lip seal, which ensures that the coil 3 has a lower friction when installed;

[0028] When coil 3 is installed Figure 7When the valve body is in the valve position, the lip 11 of the sealing ring 1 begins to enter the installation surface of the coil 3, the sealing line begins to form, and the inner cavity of the coil 3 gradually becomes a sealed cavity. When the coil 3 moves downward, according to the Clapham equation PV=nRT, when the inner cavity volume V gradually decreases, the internal pressure P will gradually increase. According to F=P×S, the upward F becomes larger, and the installation force of the coil 3 becomes larger. The downward lip 11 structure will discharge the internal gas when the internal pressure P increases, reduce the internal air pressure, and reduce the installation force of the coil 3. During the operation of the valve body, the coil 3 will produce a temperature rise, the internal gas temperature T rises, the pressure P rises, and part of the gas will be discharged. When the temperature of the coil 3 returns to room temperature, the internal pressure P is lower than the external pressure, and there is a negative pressure in the inner cavity of the coil 3, which makes it difficult for the coil 3 to fall out. When the external air pressure is higher than the internal air pressure, the contact shape of the lip tip 4 will also change, which will increase the contact stress with the installation surface of the coil 3. The lip 11 fits more closely with the sealing position to better achieve the sealing effect.

[0029] Example 2

[0030] On the basis of Example 1, Figure 6 As shown, a sealing structure of an electronic expansion valve of the utility model, the radial support 13 is composed of a gap-avoiding section 6 and the upper part of the support section 8 of the axial support 12;

[0031] like Figure 5 As shown, the structure design of the lip edge 11 makes the flash appear at the inner side 5 of the inner lip of the lip tip 4;

[0032] In this embodiment, the air avoidance section 6 serves to reduce the contact area and reduce the friction generated when the sealing ring 1 is installed. The guide section 7 serves to make the sealing ring 1 fit more easily when subjected to radial force. The support section 8 serves to axially support the sealing ring 1. The air avoidance section 6 is thickened to enhance the radial supporting force of the sealing ring 1, thereby reducing the hardness requirement of the sealing ring 1 in disguise. Structurally, the compression amount of the sealing ring 1 is adjusted by adjusting the thickness of the root to adapt to different working conditions.

[0033] The utility model provides a sealing structure of an electronic expansion valve. When the sealing ring 1 is installed on the valve core 2 and the coil 3 is installed on the valve core 2, the sealing ring 1 is simultaneously subjected to axial compression and radial compression, and the contact surface between the valve core 2 and the installation surface of the coil 3 becomes wider. This characteristic enables the lip 11 to have the ability to compensate for dimensional tolerance and angular error. During the process of pulling out the coil 3, the contact form between the lip 11 and the installation surface of the coil 3 changes from surface sealing to line sealing, so that external impurities are not easy to enter the inner cavity of the coil 3, and the next use of the sealing ring 1 is not affected.

[0034] The main functions achieved by this utility model are:

[0035] 1. Single lip seal with lower friction;

[0036] 2. It can better overcome the torsion generated during installation and eliminate the internal stress of the sealing ring;

[0037] 3. The flash edge is located in the concave position to reduce the situation of poor sealing caused by the flash edge;

[0038] 4. Strengthening the root of the lip to increase radial support force can reduce the hardness requirements of the parts in disguise;

[0039] 5. The compression of the sealing ring can be adjusted by adjusting the root thickness to optimize the structure;

[0040] 6. The inner wall is divided into a void section, a guide section and a support section to reduce the contact area with the outer wall of the valve core and thus reduce the installation force when installing the sealing ring;

[0041] 7. When installing the coil, the internal gas can be discharged smoothly to facilitate installation; when pulling out the coil, the required pulling force can be increased to prevent the coil from falling out;

[0042] 8. The downward tilted sealing lip structure can compensate for larger dimensional tolerances and angle tolerances;

[0043] 9. When pulling out, the sealing lip forms a line seal to prevent foreign matter from entering the coil;

[0044] 10. Perform axial compression and radial compression simultaneously to widen the contact area of ​​the sealing surface and enhance the sealing effect.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A sealing structure of an electronic expansion valve, characterized in that: The invention comprises a sealing ring (1), a valve core (2) and a coil (3), wherein the sealing ring (1) is sleeved on the outer wall of the valve core (2), and the coil (3) is installed on the upper part of the valve core (2); The sealing ring (1) comprises a lip (11), an axial support (12) and a radial support (13), and the lip (11), the axial support (12) and the radial support (13) constitute the shape of the sealing ring (1).

2. The sealing structure of an electronic expansion valve according to claim 1, characterized in that: The inner side of the axial support (12) is divided into a clearance section (6), a guide section (7) and a support section (8).

3. The sealing structure of an electronic expansion valve according to claim 1, characterized in that: The radial support (13) is composed of a clearance section (6) and the upper part of the support section (8) of the axial support (12).

4. The sealing structure of an electronic expansion valve according to claim 1, characterized in that: The structural design of the lip edge (11) enables the flash edge to appear at the inner side (5) of the inner lip of the lip tip (4).

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