CN117231755A

CN117231755A - Electronic expansion valve

Info

Publication number: CN117231755A
Application number: CN202210631689.2A
Authority: CN
Inventors: 张积友; 徐冠军; 陈勇好
Original assignee: Zhejiang Dunan Artificial Environment Co Ltd
Current assignee: Zhejiang Dunan Artificial Environment Co Ltd
Priority date: 2022-06-06
Filing date: 2022-06-06
Publication date: 2023-12-15
Also published as: WO2023236568A1

Abstract

The application provides an electronic expansion valve, comprising: a coil assembly having a mounting hole; the valve body assembly penetrates into the mounting hole partially; the hard sealing piece is arranged in a gap between the inner wall of the mounting hole and the outer wall of the valve body assembly, and the hard sealing piece is in sealing fit with the valve body assembly and the mounting hole. The scheme adopts the direct sealing fit of the valve body component and the hard sealing piece, and is characterized in that the valve body component and the hard sealing piece are in direct sealing fit, compared with the mode that a soft sealing piece is adopted to seal a gap between the valve body component and a mounting hole in the prior art, the scheme avoids sealing failure caused by the problems of poor high temperature resistance, easy abrasion and the like of the soft sealing, and further leads to the failure of the electronic expansion valve, the tightness between the valve body component and the coil component is ensured, and the reliability of the electronic expansion valve is improved.

Description

Electronic expansion valve

Technical Field

The application relates to the technical field of electronic expansion valves, in particular to an electronic expansion valve.

Background

After the electronic expansion valve mounting hole is assembled with the valve body assembly, a large gap exists between the mounting hole and the surface of the valve body assembly, so that pollutants such as water stains and the like are easy to flow into the coil assembly along the gap between the valve body assembly and the mounting hole, the stator shell and the stator pole plate of the coil assembly are corroded, and finally the product is invalid.

Aiming at the situation, in the electronic expansion valve in the prior art, soft sealing elements such as a sealing ring are generally adopted to seal a gap between the valve body assembly and the mounting hole, but the soft sealing elements are not high-temperature resistant and easy to wear, the electronic expansion valve is always in a vibrating state in the working process, and the situation that the sealing ring is worn to cause sealing failure is easy to occur; meanwhile, the internal temperature of the coil assembly can rise along with the work, and the high temperature can influence the sealing ring at the sealing position, so that the high temperature of the sealing ring is invalid and the service life of the sealing ring is shortened.

Disclosure of Invention

The application provides an electronic expansion valve, which solves the problem that soft sealing between a mounting hole and a valve body assembly is easy to fail in the prior art.

In order to solve the above problems, the present application provides an electronic expansion valve comprising: a coil assembly having a mounting hole; the valve body assembly penetrates into the mounting hole partially; the hard sealing piece is arranged in a gap between the inner wall of the mounting hole and the outer wall of the valve body assembly, and the hard sealing piece is in sealing fit with the valve body assembly and the mounting hole.

Further, the hard sealing element is arranged on the inner wall of the mounting hole, the radial dimension of the hard sealing element is D1, and the radial dimension of the mounting hole is D3, and D3-D1 is less than 0.2mm.

Further, the radial dimension of the hard sealing element is D1, and the outer diameter of the part of the valve body assembly in sealing fit with the hard sealing element is D2, wherein D2 is less than or equal to D1.

Further, in the axial direction of the mounting hole, a side of the hard seal facing the coil block has a first chamfer, and a side of the hard seal facing the valve body block has a second chamfer, wherein the first chamfer has a radial width L1, L1 < (D3-D1)/2 in the hard seal.

Further, the valve body assembly comprises a sleeve and a valve body part which are connected with each other, the sleeve part penetrates into the mounting hole, the hard sealing piece is an annular boss, the annular boss is located between the inner wall of the mounting hole and the outer wall of the sleeve, the annular boss is arranged on the inner wall of the mounting hole facing one end of the valve body part and is in sealing fit with the outer wall of the sleeve, or the annular boss is arranged on the outer wall of the sleeve facing one side of the valve body part and is in sealing fit with the inner wall of the mounting hole.

Further, the coil assembly comprises a plastic package shell and a coil part arranged in the plastic package shell, wherein the plastic package shell is provided with a mounting hole, and the hard sealing piece and the plastic package shell are of an integrated structure.

Further, the coil assembly comprises a plastic package shell and a coil part, wherein the plastic package shell comprises an injection molding shell and an annular part which are connected with each other, the coil part is arranged in a cavity of the injection molding shell, the injection molding shell is provided with a first through hole, the annular part is provided with a second through hole, the first through hole and the second through hole form a mounting hole, the hard sealing part is arranged on the inner wall of the second through hole, and the hard sealing part and the annular part are of an integrated structure.

Further, one end of the injection molding shell facing the annular piece is provided with a first mounting groove which surrounds the mounting hole, the annular piece comprises a first annular plate and a second annular plate which is arranged on the first annular plate, the outer diameter of the second annular plate is smaller than that of the first annular plate, the second annular plate is positioned in the first mounting groove, and the first annular plate is in butt joint with the injection molding shell; the plastic package shell further comprises a first limiting structure arranged on the plastic package shell, the annular piece further comprises a second limiting structure arranged on the first annular plate, and the first limiting structure and the second limiting structure are in limiting fit.

Further, the first limiting structure comprises a first positioning protrusion and a first positioning groove which are arranged on the injection molding shell; the second limiting structure is positioned on one side of the first annular plate facing the second annular plate and comprises a second positioning protrusion and a second positioning groove which are arranged on the first annular plate; wherein, the second location is protruding to be set up in first constant head tank, and first location is protruding to be set up in the second constant head tank.

Further, the coil assembly comprises an injection molding shell, the injection molding shell is provided with a first through hole and a first mounting groove arranged around the first through hole, the first through hole and the first mounting groove form a mounting hole, the valve body assembly comprises a sleeve pipe and a valve body part which are connected with each other, the sleeve pipe part penetrates through the first mounting groove and penetrates through the first through hole, the hard sealing piece is sleeved on the outer wall of the sleeve pipe, or the hard sealing piece and the sleeve pipe are of an integrated structure, and the hard sealing piece is in sealing fit with the inner wall of the first mounting groove.

Further, the electronic expansion valve further comprises a protective cover, the protective cover is connected with the coil assembly, the protective cover comprises a blocking head, and the blocking head blocks one opening of the mounting hole.

Further, the coil assembly comprises a plastic package shell and a coil part arranged in the plastic package shell, the plastic package shell is provided with a second mounting groove arranged around the mounting hole, the protective cover also comprises an annular limiting plate arranged around the blocking head, one end of the blocking head is inserted into the second mounting groove, and the annular limiting plate is abutted with the plastic package shell; the coil assembly further comprises a third limiting structure arranged on the plastic package shell, the protective cover further comprises a fourth limiting structure arranged on the annular limiting plate, and the third limiting structure and the fourth limiting structure are in limiting fit.

Further, the coil assembly comprises a plastic package shell and a coil part arranged in the plastic package shell, and the protective cover and the plastic package shell are of an integrated structure.

Further, the protection casing is an integral structure, the protection casing further comprises a protection sleeve connected with the plugging head, the protection sleeve is provided with a first accommodating cavity, the coil assembly is arranged in the first accommodating cavity, the plugging head is provided with a second accommodating cavity, and the second accommodating cavity is communicated with the mounting hole.

By applying the technical scheme of the application, the electronic expansion valve comprises: a coil assembly having a mounting hole; the valve body assembly penetrates into the mounting hole partially; the hard sealing piece is arranged in a gap between the inner wall of the mounting hole and the outer wall of the valve body assembly, and the hard sealing piece is in sealing fit with the valve body assembly and the mounting hole. By adopting the scheme, one end of the mounting hole of the coil assembly is blocked by the hard sealing piece, the condition that impurities enter the coil assembly from one end of the mounting hole to cause the failure of the coil assembly in the working process of the electronic expansion valve is avoided, and the reliability of the electronic expansion valve is ensured. Further, this scheme adopts valve body subassembly and annular boss direct seal complex hard seal cooperation, adopts soft sealing spare to seal the mode of clearance between valve body subassembly and the mounting hole for among the prior art, and this scheme has avoided leading to sealed inefficacy because soft sealing is not high temperature resistant, easy wearing and tearing scheduling problem, and then leads to the circumstances that electronic expansion valve became invalid, guarantees the leakproofness between valve body subassembly and the coil assembly, improves electronic expansion valve's reliability.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

fig. 1 shows a schematic structural diagram of an electronic expansion valve according to a first embodiment of the present application;

FIG. 2 shows an enlarged view of the position A in FIG. 1;

FIG. 3 shows a schematic view of the coil assembly, shield and annular boss of FIG. 1;

FIG. 4 shows an enlarged view of the position C in FIG. 3;

fig. 5 shows a schematic structural view of a coil assembly, a shield, and an annular boss according to a second embodiment of the present application;

FIG. 6 shows an enlarged view of the position B in FIG. 5;

FIG. 7 shows a schematic view of the ring of FIG. 5;

fig. 8 is a schematic structural view of an electronic expansion valve according to a third embodiment of the present application;

FIG. 9 shows an enlarged view of the D position of FIG. 8;

fig. 10 shows a schematic structural view of a coil block, a shield, and an annular boss provided in accordance with a fourth embodiment of the present application;

fig. 11 shows a schematic structural view of a coil assembly, a shield, and an annular boss provided in a fifth embodiment of the present application.

Wherein the above figures include the following reference numerals:

10. a coil assembly; 11. a mounting hole; 12. a plastic package shell; 121. injection molding of the shell; 122. a ring member; 1221. a first annular plate; 1222. a second annular plate; 1223. a second limit structure; 12231. a second positioning protrusion; 12232. a second positioning groove; 123. a first limit structure; 13. a coil section; 14. a third limit structure;

20. a protective cover; 21. a blocking head; 22. an annular limiting plate; 23. a fourth limit structure; 24. a protective sleeve;

30. a hard seal; 31. a first chamfer; 32. a second chamfer;

40. a valve body assembly; 41. a sleeve; 42. and a valve body.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

As shown in fig. 1 to 4, a first embodiment of the present application provides an electronic expansion valve, including: a coil assembly 10, the coil assembly 10 having a mounting hole 11; a valve body assembly 40, the valve body assembly 40 partially penetrating into the mounting hole 11; the hard sealing element 30, the hard sealing element 30 is arranged in the gap between the inner wall of the mounting hole 11 and the outer wall of the valve body assembly 40, and the hard sealing element 30 is in sealing fit with both the valve body assembly 40 and the mounting hole 11.

In this embodiment, the hard sealing member 30 is used to seal one end of the mounting hole 11 of the coil assembly 10, so as to avoid the situation that impurities enter the coil assembly 10 from one end of the mounting hole 11 to cause the failure of the coil assembly 10 in the working process of the electronic expansion valve, and ensure the reliability of the electronic expansion valve. Further, the valve body assembly 40 and the hard sealing piece 30 are in direct sealing fit, compared with the mode that a soft sealing piece is adopted to seal a gap between the valve body assembly and a mounting hole in the prior art, the sealing failure caused by the problems of poor high temperature resistance, easy abrasion and the like of the soft sealing is avoided, the failure condition of the electronic expansion valve is further caused, the sealing performance between the valve body assembly 40 and the coil assembly 10 is ensured, and the reliability of the electronic expansion valve is improved.

As shown in FIG. 2, the hard seal 30 is provided on the inner wall of the mounting hole 11, the radial dimension of the hard seal 30 is D1, and the radial dimension of the mounting hole 11 is D3, D3-D1 < 0.2mm. In this embodiment, the dimensions of D1 and D3 are defined, so that the stability of the seal between the hard seal 30 and the valve body assembly 40 is ensured, the reliability of the assembly of the coil assembly 10 and the valve body assembly 40 is ensured, the situation that the coil assembly 10 and the valve body assembly 40 are not easy to assemble due to interference or the influence of precision when D1 and D3 are close or D3 is smaller than D1 is avoided, and the reliability of the electronic expansion valve is ensured.

Specifically, the radial dimension of the hard seal 30 is D1, and the outer diameter of the portion of the valve body assembly 40 in sealing engagement with the hard seal 30 is D2, D2. Ltoreq.D1. In the present embodiment, the dimensions of D1 and D2 are defined to further ensure the stability of the seal between the hard seal 30 and the valve body assembly 40 and the reliability of the assembly of the coil assembly 10 and the valve body assembly 40. Specifically, at d2=d1, the sealing effect between the hard seal 30 and the valve body assembly 40 is optimal.

Further, in the axial direction of the mounting hole 11, the side of the hard seal member 30 facing the coil block 10 has a first chamfer 31, and the side of the hard seal member 30 facing the valve body block 40 has a second chamfer 32, wherein the first chamfer 31 has a radial width L1, L1 < (D3-D1)/2 in the hard seal member 30. In the present embodiment, by limiting the size of the first chamfer 31, the sealing effect between the hard seal 30 and the valve body assembly 40 is ensured, and at the same time, the structural strength of the hard seal 30 is improved, and the reliability and stability of the sealing of the hard seal 30 are ensured.

Specifically, the valve body assembly 40 includes a sleeve 41 and a valve body portion 42 connected to each other, the sleeve 41 partially penetrates into the mounting hole 11, the hard seal member 30 is an annular boss located between an inner wall of the mounting hole 11 and an outer wall of the sleeve 41, the annular boss is disposed on an inner wall of the mounting hole 11 facing one end of the valve body portion 42 and is in sealing engagement with the outer wall of the sleeve 41, or the annular boss is disposed on an outer wall of the sleeve 41 facing one side of the valve body portion 42 and is in sealing engagement with the inner wall of the mounting hole 11. This arrangement facilitates the processing and placement of the annular boss and facilitates the sealing of the annular boss to the gap between the sleeve 41 and the coil assembly 10.

Alternatively, an annular boss may be provided on the outer peripheral surface of the sleeve 41 and integrally provided with the sleeve 41, or, in an electronic expansion valve of other structure, an annular boss may be provided on the outer peripheral surface of the valve body 42 and integrally provided with the valve body 42.

As shown in fig. 3 and 4, the coil assembly 10 includes a plastic package case 12 and a coil portion 13 provided in the plastic package case 12, the plastic package case 12 having a mounting hole 11, a hard seal 30 and the plastic package case 12 being an integral structure. This arrangement facilitates the processing of the hard seal 30.

Specifically, the electronic expansion valve further includes a protective cover 20, the protective cover 20 is connected to the coil assembly 10, the protective cover 20 includes a blocking head 21, and the blocking head 21 blocks one opening of the mounting hole 11.

In this embodiment, by providing the shield 20, it is avoided that water stains flowing in from the upper opening of the coil assembly 10 flow into the coil portion 13 along the gap between the sleeve 41 and the mounting hole 11, or that fluid directly enters into the coil portion 13 from the upper opening of the coil assembly 10, thereby causing rust of the coil stator housing and the stator plate, eventually leading to failure of the product, and ensuring reliability of the electronic expansion valve.

As shown in fig. 3, the coil assembly 10 includes a plastic package case 12 and a coil part 13 disposed in the plastic package case 12, the plastic package case 12 has a second mounting groove disposed around the mounting hole 11, the protection cover 20 further includes an annular limiting plate 22 disposed around the blocking head 21, one end of the blocking head 21 is inserted into the second mounting groove, and the annular limiting plate 22 abuts against the plastic package case 12; the coil assembly 10 further includes a third limiting structure 14 disposed on the plastic package 12, and the protective cover 20 further includes a fourth limiting structure 23 disposed on the annular limiting plate 22, where the third limiting structure 14 and the fourth limiting structure 23 are in limiting fit.

In this embodiment, the blocking head 21 is inserted into the second installation groove and is in spacing fit with the second installation groove, so that the protective cover 20 is installed and positioned, and the protective cover 20 and the plastic package shell 12 are in spacing fit with each other through the third spacing structure 14 and the fourth spacing structure 23, so that the positioning accuracy of the protective cover 20 and the plastic package shell 12 is further improved, and the installation reliability and the connection stability of the protective cover 20 and the plastic package shell 12 are ensured.

Specifically, as shown in fig. 3, the third limiting structure 14 includes a third positioning protrusion and a third positioning groove disposed on the plastic package housing 12, the fourth limiting structure 23 includes a fourth positioning protrusion and a fourth positioning groove disposed on the annular limiting plate 22, the third positioning protrusion and the fourth positioning protrusion are annular protrusions, the third positioning groove and the fourth positioning groove are annular grooves, the third positioning protrusion is disposed in the fourth positioning groove and is in spacing fit with the fourth positioning groove, and the fourth positioning protrusion is disposed in the third positioning groove and is in spacing fit with the third positioning groove. The device comprises two third positioning protrusions, two third positioning grooves and two fourth positioning grooves, wherein the third positioning grooves are arranged between the two third positioning protrusions; or the number of the third positioning grooves is two, the third positioning protrusions are arranged between the two third positioning grooves, the number of the fourth positioning protrusions is two, and the fourth positioning grooves are arranged between the two fourth positioning protrusions. The arrangement is convenient for realizing the positioning connection of the protective cover 20 and the plastic package shell 12, and ensures the reliability and stability of the connection of the plastic package shell 12 and the protective cover 20.

Optionally, the number of the third positioning protrusions, the fourth positioning protrusions, the third positioning grooves and the fourth positioning grooves can be adjusted according to practical situations.

As shown in fig. 5 to 7, the second embodiment of the present application provides an electronic expansion valve, which is different from the above embodiment in that the coil assembly 10 includes a plastic package case 12 and a coil part 13, the plastic package case 12 includes an injection molding case 121 and a ring member 122 connected to each other, the coil part 13 is located in a cavity of the injection molding case 121, the injection molding case 121 has a first through hole, the ring member 122 has a second through hole, the first through hole and the second through hole constitute a mounting hole 11, the hard seal member 30 is disposed on an inner wall of the second through hole, and the hard seal member 30 and the ring member 122 are integrally constructed. So arranged, the hard seal 30 and the ring 122 are integrally formed to facilitate the processing of the hard seal 30. Specifically, the injection molding case 121 and the ring 122 are separately provided, and the ring 122 and the injection molding case 121 are welded to each other.

Specifically, the end of the injection molding case 121 facing the ring member 122 has a first mounting groove provided around the mounting hole 11, the ring member 122 includes a first annular plate 1221 and a second annular plate 1222 provided on the first annular plate 1221, the second annular plate 1222 has an outer diameter smaller than that of the first annular plate 1221, the second annular plate 1222 is located in the first mounting groove, and the first annular plate 1221 abuts against the injection molding case 121; the plastic package housing 12 further includes a first limiting structure 123 disposed on the injection molding housing 121, and the ring member 122 further includes a second limiting structure 1223 disposed on the first annular plate 1221, where the first limiting structure 123 and the second limiting structure 1223 are in a limiting fit.

In this embodiment, the second annular plate 1222 of the annular member 122 is disposed in the first mounting groove and is in limit fit with the first mounting groove, so that the annular member 122 is mounted and positioned, the first annular plate 1221 and the injection molding shell 121 are abutted and in limit fit through the first limit structure 123 and the second limit structure 1223, so that the positioning accuracy of the annular member 122 is further improved, and the mounting reliability and the connection stability of the annular member 122 and the injection molding shell 121 are ensured.

Optionally, the injection molded shell 121 is integral with the first limiting structure 123, and the ring 122 is integral with the second limiting structure 1223. The injection molded case 121 and the ring 122 are coupled by a welding process.

Further, the first limiting structure 123 includes a first positioning protrusion and a first positioning groove provided on the injection molding case 121; the second limiting structure 1223 is located at a side of the first annular plate 1221 facing the second annular plate 1222, and the second limiting structure 1223 includes a second positioning protrusion 12231 and a second positioning groove 12232 provided on the first annular plate 1221; wherein the second positioning protrusion 12231 is disposed in the first positioning groove, and the first positioning protrusion is disposed in the second positioning groove 12232. In this way, the positioning of the injection molding shell 121 and the first annular plate 1221 is completed through the limit fit of the positioning protrusion and the positioning groove, so that the mounting precision and the positioning reliability are improved. Specifically, as shown in fig. 3, the first positioning protrusion and the second positioning protrusion 12231 in the present embodiment are annular protrusions, the first positioning groove and the second positioning protrusion 12232 are annular grooves, the first positioning protrusion and the second positioning protrusion 12231 are two, the first positioning protrusion is disposed between the two first positioning grooves, the second positioning protrusion 12232 is disposed between the two second positioning protrusions 12231, and the reliability and stability of the connection between the injection molding case 121 and the first annular plate 1221 are further ensured.

Alternatively, the number of the first positioning projections, the second positioning projections 12231, the first positioning grooves, and the second positioning grooves 12232 may be adjusted according to actual conditions.

As shown in fig. 8 and 9, the third embodiment of the present application provides an electronic expansion valve, which is different from the above-described embodiment in that the coil assembly 10 includes an injection molded case 121 having a first through hole and a first mounting groove provided around the first through hole, the first through hole and the first mounting groove constituting the mounting hole 11, the valve body assembly 40 includes a sleeve 41 and a valve body part 42 connected to each other, the sleeve 41 partially penetrates the first mounting groove and is inserted into the first through hole, the hard seal member 30 is sleeved on an outer wall of the sleeve 41, or the hard seal member 30 and the sleeve 41 are integrally constructed, and the hard seal member 30 and an inner wall of the first mounting groove are hermetically engaged. The setting like this, but hard seal 30 and sleeve pipe 41 integrated into one piece processing set up, be convenient for to the rapid tooling of hard seal 30, or, but hard seal 30 and sleeve pipe 41 components of a whole that can function independently processing and fixed connection, be convenient for guarantee the structural strength of hard seal 30 and sleeve pipe 41 simultaneously, hard seal 30 sets up in first mounting groove and with first mounting groove seal fit, guaranteed the sealed effect of hard seal 30 to the clearance between mounting hole 11 and the sleeve pipe 41, guaranteed sealed reliability.

As shown in fig. 10, the fourth embodiment of the present application provides an electronic expansion valve, which is different from the above-described embodiment in that the coil assembly 10 includes a plastic package case 12 and a coil part 13 provided in the plastic package case 12, and the shield 20 and the plastic package case 12 are integrally constructed. This arrangement facilitates the machining of the shield 20.

As shown in fig. 11, a fifth embodiment of the present application provides an electronic expansion valve, which is different from the above embodiment in that the protection cover 20 is of an integral structure, the protection cover 20 further includes a protection cover 24 connected to the blocking head 21, the protection cover 24 has a first accommodating cavity, the coil assembly 10 is disposed in the first accommodating cavity, the blocking head 21 has a second accommodating cavity, and the second accommodating cavity is communicated with the mounting hole 11. By the arrangement, the whole protection of the coil assembly 10 is realized through the protective cover 20, the reliability of the coil assembly 10 is improved, and the performance of the electronic expansion valve is ensured.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An electronic expansion valve, comprising:

a coil assembly (10), the coil assembly (10) having a mounting hole (11);

a valve body assembly (40), the valve body assembly (40) partially penetrating into the mounting hole (11);

the hard sealing piece (30) is arranged in a gap between the inner wall of the mounting hole (11) and the outer wall of the valve body assembly (40), and the hard sealing piece (30) is in sealing fit with the valve body assembly (40) and the mounting hole (11).

2. Electronic expansion valve according to claim 1, characterized in that the hard seal (30) is arranged on the inner wall of the mounting hole (11), the radial dimension of the hard seal (30) is D1, the radial dimension of the mounting hole (11) is D3, D3-D1 < 0.2mm.

3. The electronic expansion valve of claim 2, wherein the radial dimension of the hard seal (30) is D1, and the outer diameter of the portion of the valve body assembly (40) in sealing engagement with the hard seal (30) is D2, D2 +.d1.

4. The electronic expansion valve according to claim 2, characterized in that in the axial direction of the mounting hole (11), a side of the hard seal (30) facing the coil assembly (10) has a first chamfer (31), a side of the hard seal (30) facing the valve body assembly (40) has a second chamfer (32), wherein the first chamfer (31) has a radial width L1, L1 < (D3-D1)/2 in the hard seal (30).

5. The electronic expansion valve according to claim 1, wherein the valve body assembly (40) comprises a sleeve (41) and a valve body (42) which are connected with each other, the sleeve (41) penetrates into the mounting hole (11) partially, the hard sealing element (30) is an annular boss which is positioned between the inner wall of the mounting hole (11) and the outer wall of the sleeve (41), and the annular boss is arranged on the inner wall of the mounting hole (11) facing one end of the valve body (42) and is in sealing fit with the outer wall of the sleeve (41), or the annular boss is arranged on the outer wall of the sleeve (41) facing one side of the valve body (42) and is in sealing fit with the inner wall of the mounting hole (11).

6. The electronic expansion valve according to claim 1, wherein the coil assembly (10) includes a plastic package case (12) and a coil portion (13) provided in the plastic package case (12), the plastic package case (12) having the mounting hole (11), the hard seal (30) and the plastic package case (12) being of an integral structure.

7. The electronic expansion valve according to claim 1, wherein the coil assembly (10) comprises a plastic package housing (12) and a coil part (13), the plastic package housing (12) comprises an injection molding housing (121) and an annular part (122) which are connected with each other, the coil part (13) is positioned in a cavity of the injection molding housing (121), the injection molding housing (121) is provided with a first through hole, the annular part (122) is provided with a second through hole, the first through hole and the second through hole form the mounting hole (11), the hard sealing part (30) is arranged on an inner wall of the second through hole, and the hard sealing part (30) and the annular part (122) are of an integral structure.

8. The electronic expansion valve according to claim 7, wherein an end of the injection molded case (121) facing the ring member (122) has a first mounting groove provided around the mounting hole (11), the ring member (122) includes a first annular plate (1221) and a second annular plate (1222) provided on the first annular plate (1221), an outer diameter of the second annular plate (1222) is smaller than an outer diameter of the first annular plate (1221), the second annular plate (1222) is located in the first mounting groove, and the first annular plate (1221) and the injection molded case (121) abut; the plastic package shell (12) further comprises a first limiting structure (123) arranged on the plastic package shell (121), the annular piece (122) further comprises a second limiting structure (1223) arranged on the first annular plate (1221), and the first limiting structure (123) is in limiting fit with the second limiting structure (1223).

9. The electronic expansion valve according to claim 8, wherein the first limiting structure (123) comprises a first positioning protrusion and a first positioning groove provided on the injection casing (121); the second limiting structure (1223) is located at one side of the first annular plate (1221) facing the second annular plate (1222), and the second limiting structure (1223) comprises a second positioning protrusion (12231) and a second positioning groove (12232) arranged on the first annular plate (1221); wherein the second positioning protrusion (12231) is disposed in the first positioning groove, and the first positioning protrusion is disposed in the second positioning groove (12232).

10. The electronic expansion valve according to claim 1, wherein the coil assembly (10) comprises an injection molded case (121), the injection molded case (121) has a first through hole and a first mounting groove disposed around the first through hole, the first through hole and the first mounting groove form the mounting hole (11), the valve body assembly (40) comprises a sleeve (41) and a valve body part (42) which are connected with each other, the sleeve (41) partially penetrates through the first mounting groove and is penetrated in the first through hole, the hard seal member (30) is sleeved on an outer wall of the sleeve (41), or the hard seal member (30) and the sleeve (41) are in an integral structure, and the hard seal member (30) and an inner wall of the first mounting groove are in sealing fit.

11. The electronic expansion valve according to claim 1, further comprising a shield (20), the shield (20) being connected to the coil assembly (10), the shield (20) comprising a blocking head (21), the blocking head (21) blocking one opening of the mounting hole (11).

12. The electronic expansion valve according to claim 11, wherein the coil assembly (10) includes a plastic package case (12) and a coil portion (13) disposed within the plastic package case (12), the plastic package case (12) having a second mounting groove disposed around the mounting hole (11), the protective cover (20) further including an annular limiting plate (22) disposed around the plugging head (21), one end of the plugging head (21) being inserted into the second mounting groove, the annular limiting plate (22) abutting the plastic package case (12); the coil assembly (10) further comprises a third limiting structure (14) arranged on the plastic package shell (12), the protective cover (20) further comprises a fourth limiting structure (23) arranged on the annular limiting plate (22), and the third limiting structure (14) is in limiting fit with the fourth limiting structure (23).

13. The electronic expansion valve according to claim 11, wherein the coil assembly (10) includes a plastic package housing (12) and a coil portion (13) disposed within the plastic package housing (12), the shield (20) and the plastic package housing (12) being of unitary construction.

14. The electronic expansion valve according to claim 11, wherein the protective cover (20) is of an integral structure, the protective cover (20) further comprises a protective cover (24) connected with the plugging head (21), the protective cover (24) is provided with a first accommodating cavity, the coil assembly (10) is arranged in the first accommodating cavity, the plugging head (21) is provided with a second accommodating cavity, and the second accommodating cavity is communicated with the mounting hole (11).