CN110529605B

CN110529605B - Electronic expansion valve

Info

Publication number: CN110529605B
Application number: CN201810516848.8A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2018-05-25
Filing date: 2018-05-25
Publication date: 2024-04-19
Anticipated expiration: 2038-05-25
Also published as: CN110529605A

Abstract

The invention provides an electronic expansion valve, comprising: the valve seat is provided with a valve seat cavity and comprises a mounting port and a valve port; the support frame is fixedly connected with the valve seat, at least part of the support frame extends into the valve seat cavity through the mounting opening, and the support frame comprises a first cylinder section and a second cylinder section; the outer wall of the valve needle is matched with the inner wall of the second cylinder section, at least part of the valve needle is movably arranged on the support frame, and a limiting structure is arranged between the first cylinder section and the valve needle; the screw rod can rotate along the axis of the screw rod, the screw rod is matched with the valve needle through a threaded structure, and the valve needle is driven by the screw rod to approach or depart from the valve port. By applying the technical scheme of the invention, the structure of the electronic expansion valve can be simplified, the assembly efficiency is improved, and the production cost is reduced.

Description

Electronic expansion valve

Technical Field

The invention relates to the technical field of refrigeration control, in particular to an electronic expansion valve.

Background

The electronic expansion valve structure is composed of a driving part (a coil 7 and a rotor 8) and a flow regulating part (a nut 3, a screw rod 4, a shell, a valve needle 5, a valve seat 9, a connecting pipe and the like). Specifically, the rotor 8 is connected to an input end of the speed reducer, and the screw 4 is connected to an output end of the speed reducer (the screw 4 is rotatable together with the output end of the speed reducer, and the relative position of the screw 4 to the output end of the speed reducer in the axial direction thereof may be changed). The nut 3 is fixed on the valve seat 9 and is in threaded connection with the screw rod 4, and the valve needle 5 is fixedly connected with the screw rod 4. The working principle of the product is briefly stated below: the rotor 8 is driven by the coil 7 to rotate, the input shaft of the speed reducer rotates under the drive of the rotor, and after the speed reducer is used for reducing the speed, the output end of the speed reducer rotates at a small rotating speed. Under the action of the output end of the speed reducer, the screw rod 4 rotates. The screw rod 4 realizes axial movement through threaded fit with the nut 3. Under the action of the screw rod 4, the valve needle 5 is axially lifted to approach or separate from the valve port 6. The electronic expansion valve can realize the purpose of adjusting the flow, but has a complex structure and high production cost.

Disclosure of Invention

The invention mainly aims to provide an electronic expansion valve, which can simplify the structure of the electronic expansion valve and reduce the production cost.

In order to achieve the above object, the present invention provides an electronic expansion valve comprising: the valve seat is provided with a valve seat cavity and comprises a mounting port and a valve port; the support frame is fixedly connected with the valve seat, at least part of the support frame extends into the valve seat cavity through the mounting opening, and the support frame comprises a first cylinder section and a second cylinder section; the outer wall of the valve needle is matched with the inner wall of the second cylinder section, at least part of the valve needle is movably arranged on the support frame, and a limiting structure is arranged between the first cylinder section and the valve needle; the screw rod can rotate along the axis of the screw rod, the screw rod is matched with the valve needle through a threaded structure, and the valve needle is driven by the screw rod to approach or depart from the valve port.

By applying the technical scheme of the invention, when the screw rod rotates, the valve needle in threaded fit with the screw rod can approach or depart from the valve port so as to realize the opening and closing of the valve port. Because the screw rod and the valve needle are directly matched through threads, the screw rod and the valve needle are not connected through nuts mentioned in the background art, parts are reduced, the whole structure of the electronic expansion valve product is simplified, and the production cost is reduced.

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 is a schematic view showing the internal structure of an electronic expansion valve according to the prior art;

FIG. 2 shows a schematic longitudinal cross-sectional view of an embodiment of an electronic expansion valve according to the present invention with a valve needle abutting a valve port;

fig. 3 shows an enlarged schematic structural view of the electronic expansion valve of fig. 2 at a;

fig. 4 shows an enlarged schematic structural view of the electronic expansion valve of fig. 2 at B;

FIG. 5 shows a schematic longitudinal section of the valve needle bypass port of the electronic expansion valve of FIG. 2;

FIG. 6 shows a schematic longitudinal cross-sectional view of the valve needle of the electronic expansion valve of FIG. 2 mated with a support frame;

FIG. 7 is a schematic perspective view showing a supporting frame of the electronic expansion valve of FIG. 2;

FIG. 8 shows a schematic longitudinal section of the support stand of FIG. 7;

FIG. 9 is a schematic perspective view showing a support bracket cover of the electronic expansion valve of FIG. 2;

FIG. 10 shows a schematic longitudinal cross-sectional view of the support bracket cover of FIG. 9;

fig. 11 shows a schematic perspective view of the valve needle of the electronic expansion valve of fig. 2;

Fig. 12 shows a schematic longitudinal section of the valve needle of fig. 11;

FIG. 13 shows a schematic longitudinal cross-sectional view of a valve seat of the electronic expansion valve of FIG. 2;

FIG. 14 shows a schematic perspective view of the valve seat body of the valve seat of FIG. 13;

FIG. 15 shows a schematic perspective view of the valve seat of FIG. 13; and

Fig. 16 shows a schematic longitudinal section of the valve core holder of fig. 15.

Wherein the above figures include the following reference numerals:

1. A valve seat cavity; 2. a receiving chamber; 10. a valve seat; 11. a valve seat body; 12. a valve core seat; 121. a valve port; 20. a valve needle; 21. a valve needle body; 211. a valve needle top wall; 212. a valve needle sidewall; 213. a first mounting hole; 214. a second mounting hole; 22. a first sealing structure; 30. a screw rod; 32. a step surface; 50. a driving mechanism; 51. a rotor; 52. a coil; 60. a limit structure; 100. a housing; 130. a support frame; 135. a first barrel section; 136. a second barrel section; 137. an annular groove; 138. an annular convex edge; 140. a second sealing structure; 150. a bump structure; 160. a first groove; 190. a connecting frame; 200. a valve needle cavity; 230. a mounting port; 240. a support frame cover; 242. a guide cylinder.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

As shown in fig. 2, 5 to 8 and 13, in the present embodiment, the electronic expansion valve includes: valve seat 10, support frame 130, needle 20 and lead screw 30. The valve seat 10 has a valve seat chamber 1, and the valve seat 10 includes a mounting port 230 and a valve port 121. The support 130 is fixedly connected with the valve seat 10, at least part of the support 130 extends into the valve seat cavity 1 through the mounting opening 230, and the support 130 comprises a first barrel section 135 and a second barrel section 136. The outer wall of the valve needle 20 is adapted to the inner wall of the second barrel section 136, at least part of the valve needle 20 is movably arranged on the support 130, a limit structure 60 is arranged between the first barrel section 135 and the valve needle 20, and the valve needle 20 does not rotate along the axis of the valve needle. The screw rod 30 can rotate along the axis of the screw rod 30, the position of the screw rod 30 in the axial direction is unchanged, the screw rod 30 is matched with the valve needle 20 through a threaded structure, and the valve needle 20 is driven by the screw rod 30 to approach or depart from the valve port 121.

By applying the technical scheme of the embodiment, when the screw rod 30 rotates, the valve needle 20 in threaded fit with the screw rod can approach or depart from the valve port to realize the opening and closing of the valve port. Because the screw rod 30 and the valve needle 20 are directly matched through threads, the screw rod is not connected through nuts mentioned in the background art, and parts are reduced, so that the assembly efficiency of the electronic expansion valve can be greatly improved, and the production cost is greatly reduced. Furthermore, by applying the solution of the present invention, the outer wall of the valve needle 20 is adapted to the inner wall of the second barrel section 136, and a limit structure 60 is arranged between the valve needle 20 and the first barrel section 135. In the above structure, the second barrel section 136 of the support frame 130 can guide the valve needle 20, so as to avoid the deflection phenomenon of the valve needle 20 when moving; the limit structure 60 located between the first barrel section 135 and the valve needle 20 limits rotation of the valve needle 20 in the circumferential direction, thereby ensuring that the valve needle 20 is able to move axially under the influence of the lead screw 30. Therefore, the supporting frame 130 can play a role in guiding and limiting at the same time, so that parts are further reduced, and the assembly efficiency of the electronic expansion valve is improved.

The above-mentioned "the position of the lead screw 30 in the axial direction is unchanged" refers to two cases: in the first case, the position of the screw 30 is completely fixed in the axial direction; in the second case, the screw 30 can be moved to a very small extent in the axial direction due to tolerance effects. In the present embodiment, the above-described "the needle 20 does not rotate along its own axis" refers to two cases: in the first case, the needle 20 does not spin at all; in the second case, the valve needle 20 can perform a small range of rotation (small rotation angle) in the circumferential direction due to tolerance influence.

As shown in fig. 2, 4 and 5 to 8, in the present embodiment, the support 130 is an integrally formed structure, the first barrel section 135 is located outside the valve seat cavity 1, the second barrel section 136 is located in the valve seat cavity 1, one of the first barrel section 135 and the valve needle 20 is provided with a protrusion structure 150, the other of the first barrel section 135 and the valve needle 20 is provided with a first groove 160, the protrusion structure 150 and the first groove 160 form a limiting structure 60, and the protrusion structure 150 can axially move along the first groove 160. Specifically, in the present embodiment, the needle 20 is threadedly engaged with the lead screw 30. The screw 30 is capable of rotating and the position in the axial direction remains unchanged. The needle 20 is movable in the axial direction and is not rotatable. When the screw rod 30 rotates, the valve needle 20 has a rotating trend under the driving of the screw rod 30, and at this time, the side wall of the protrusion structure 150 between the valve needle 20 and the first barrel section 135 will be abutted by the wall of the first groove 160, so that the valve needle 20 cannot rotate. However, the needle 20 can move in the axial direction by the engagement of the internal and external threads, thereby opening and closing the valve port. The structure is simple and easy to process.

As shown in fig. 2 and 5-8, in this embodiment, the top of the first barrel section 135 is provided with a downwardly extending elongated slot that forms a first recess 160. The structure is simple, and the processing and the assembly are easy.

As shown in fig. 11 and 12, in the present embodiment, the top of the side wall of the valve needle 20 is provided with a first mounting hole 213, and the protrusion structure 150 is a pin inserted into the first mounting hole 213, and a part of the pin protrudes from the side wall of the valve needle 20 and is engaged with the first groove 160. The structure is simple and easy to process.

As shown in fig. 2, 5 and 12, in the present embodiment, the valve needle 20 includes a valve needle body 21 and a first sealing structure 22 disposed at the bottom of the valve needle body 21, the valve needle 20 is in a fully closed state, the first sealing structure 22 is in abutting engagement with the valve port 121, the valve needle body 21 includes a valve needle top wall 211 and a valve needle side wall 212, a second mounting hole 214 extending downward is disposed on the valve needle top wall 211, a screw thread structure is disposed on an inner wall of the second mounting hole 214, and a screw rod 30 is disposed in the second mounting hole 214 in a penetrating manner and is engaged with the screw thread structure, and the first mounting hole 213 is disposed at the top of the valve needle side wall 212 and extends inward. The structure is simple and easy to realize.

Preferably, as shown in fig. 2 and 5, in the present embodiment, the valve seat 10 is provided with a first interface and a second interface, the first interface is communicated with the valve port 121, the valve needle is provided with a valve needle cavity 200 communicated with the valve port 121, the first interface (standpipe interface) and the valve needle cavity 200 form a penetration, and the outer diameter of the valve needle body 21 is equal to the diameter of the valve port 121. When the valve needle 20 is in the closed position and refrigerant enters the valve needle chamber 200 from the first port, the valve needle 20 is blocked at the valve port 121 by a downward differential pressure force and a downward driving force and is maintained in the closed position. The pressure difference force is formed by the effect of the pressure and the area difference between the cross-sectional area of the needle body 21 and the cross-sectional area of the valve port 121. Since the outer diameter of the needle body 21 is equal to the diameter of the valve port 121, the differential pressure force is zero, so that the above-described structure no longer requires a downward urging force to be applied to the core assembly by the spring, and therefore the driving force does not have to be increased even if the diameter of the valve port 121 is increased.

In addition, when the refrigerant enters the valve seat 10 from the second port (cross pipe port), the valve needle 20 receives an upward pressure difference force and a downward driving force to cause the valve needle 20 to block at the valve port 121 and to be held in the closed position. The pressure difference force is formed by the effect of the pressure and the area difference between the cross-sectional area of the needle body 21 and the cross-sectional area of the valve port 121. Since the outer diameter of the needle body 21 is equal to the path of the valve port 121, the differential pressure force is zero. Since the differential pressure force is zero, the demand for driving force is greatly reduced.

The screw rod 30 is in a slender rod shape, and the screw rod 30 may deflect when rotating, so that the valve needle 20 connected with the screw rod 30 also deflects, and finally the valve needle 20 is easy to collide with the valve seat 10. In order to solve the above-described problems, as shown in fig. 2 to 6, in the present embodiment, the electronic expansion valve further includes: the support frame cover 240 is arranged on the top of the first cylinder section 135, and a guide part is arranged on the support frame cover 240 and provides a guide function for the screw rod 30. The guide part can keep the axis of the screw rod 30 at a preset position, so that the screw rod 30 is prevented from swinging during rotation, and finally the problem that the valve needle 20 is easy to collide with the valve seat 10 is solved.

As shown in fig. 3, 9 and 10, in the present embodiment, the guide portion is a guide cylinder 242 that is disposed on the support frame cover 240 and extends upward, a part of the screw rod 30 is disposed in the guide cylinder 242 in a penetrating manner, a step surface 32 is disposed on a side wall of the screw rod 30, and a top surface of the guide cylinder 242 is in abutting engagement with the step surface 32. The structure is simple and easy to process. Further, a support frame cover 240 is fixedly connected to the top of the first barrel section 135, and the weight of the support frame 130 is borne by the valve seat 10. Since the top surface of the guide cylinder 242 can support the stepped surface 32, the weight of the lead screw 30 and the needle 20 screwed to the lead screw 30 is borne by the support frame 130, and the support frame 130 transfers the weight to the valve seat 10, and finally, the valve seat 10. Therefore, the above structure can prevent the screw 30 from moving downward in the axial direction.

As shown in fig. 2, in the present embodiment, the electronic expansion valve further includes: the driving mechanism 50 comprises a rotor 51 and a coil 52, wherein the rotor 51 is fixedly connected with the screw rod 30, and the rotor 51 drives the screw rod 30 to rotate through the coil 52; the shell 100 is fixedly connected with the valve seat 10 and is positioned above the valve seat 10, the shell 100 is internally provided with a containing cavity 2, the rotor 51, the screw rod 30 and the first barrel section 135 are all positioned in the containing cavity 2, and the top end of the screw rod 30 is in butt fit with the top wall of the shell 100. The above structure enables more precise components to be located inside the housing 100, avoiding contact with dust and moisture, thereby improving the service life. In addition, the top end of the screw 30 is in abutting engagement with the top wall of the housing 100, so that upward movement of the screw 30 during rotation can be avoided.

As shown in fig. 6, in the present embodiment, a second sealing structure 140 is provided between the second barrel section 136 and the valve needle 20. The second sealing structure 140 can prevent the first interface and the second interface from communicating with the gap between the valve needle 20 and the second barrel 136, and prevent the inside of the valve seat 10 from communicating with the outside, so as to effectively isolate the transmission of the vertical differential pressure of the valve needle 20, and ensure that the valve needle 20 can be abutted against the valve port 121 under the action of the differential pressure.

As shown in fig. 6 and 8, in the present embodiment, the bottom of the inner wall of the second barrel section 136 is provided with an annular groove 137, and the second sealing structure 140 is a seal ring provided in the annular groove 137. The structure is simple, and the processing and the assembly are easy.

As shown in fig. 6 to 8, in the present embodiment, an annular protruding edge 138 is provided on the outer wall of the supporting frame 130, the annular protruding edge 138 is located at the connection position of the first barrel section 135 and the second barrel section 136, and the lower surface of the annular protruding edge 138 abuts against the upper surface of the valve seat 10. In the above structure, the upper surface of the valve seat 10 can support the lower surface of the annular flange 138, so that the valve seat 10 can bear the weight of the support frame 130. The structure is simple and easy to process.

In the present embodiment, the supporting frame 130 is an integrally formed structure. The structure is simple, the processing is convenient, and the production cost is low.

As shown in fig. 13 to 16, in the present embodiment, the valve seat 10 includes a valve seat body 11 and a valve seat 12, an opening is provided at the bottom of the valve seat body 11, the valve seat 12 is provided at the opening, a valve port 121 is provided at the valve seat 12, and a space surrounded by the valve seat body 11 and the valve seat 12 forms the valve seat chamber 1. The valve seat body 11 is formed by stretching. The above-described structure is simple, so that the needle 20 can be smoothly attached to the valve seat 10. It should be noted that, in other embodiments, the valve seat body 11 may be integrally formed by a punching process or a cold heading process.

As shown in fig. 2 and 5, in the present embodiment, the rotor 51 is fixedly connected to the screw 30 through a connection frame 190, wherein the rotor 51 and the connection frame 190 are integrally formed.

The following describes the specific scheme of the present embodiment in detail in conjunction with the principle of operation:

Under the excitation of the coil 52 sleeved on the outer periphery of the housing 100, the rotor 51 rotates to drive the screw rod 30 to rotate, and the screw rod 30 drives the valve needle 20 to move upwards axially due to the screwing action of the external thread of the screw rod 30 and the internal thread of the valve needle 20. The valve needle 20 performs only the lifting movement in the axial direction without rotating, so that the first sealing structure 22 of the valve needle 20 gradually moves away from the valve port 121. When the pin fixed on the valve needle 20 is abutted against the supporting frame cover 240, the distance between the first sealing structure 22 of the valve needle 20 and the valve port 121 is the largest, and at this time, the flow rate of the refrigerant flowing through the valve port 121 is also the largest; when the exciting rotor 51 of the coil 52 rotates reversely, the valve needle 20 moves downward in the axial direction by the screwing action of the external thread and the internal thread of the screw rod 30, and at this time, the first seal structure 22 of the valve needle 20 gradually approaches the valve port 121, and when the pin fixed to the valve needle 20 approaches the lower end portion of the first groove 160 of the first barrel section 135 relatively, the first seal structure 22 abuts against the valve port 121.

The following briefly describes the steps for installing the electronic expansion valve:

Step one: a10 The valve seat 10 is formed by machining and is welded and fixed with the valve core seat 12, the first connecting pipe and the second connecting pipe respectively;

Step two: a20 The valve needle 20 is flip-chip press-fitted into the lower end opening of the support 130

Step three: a30 After being press-fitted into the valve seat 10 through the second cylinder section 136 of the support frame 130, the support frame 130 and the valve seat 10 are welded and fixed;

step four: a40 The housing 100 and other components are mounted.

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

Claims

1. An electronic expansion valve, comprising:

a valve seat (10) having a valve seat cavity (1), the valve seat (10) comprising a mounting opening (230) and a valve port (121);

the support frame (130), the support frame (130) is fixedly connected with the valve seat (10), at least part of the support frame (130) stretches into the valve seat cavity (1) through the mounting opening (230), and the support frame (130) comprises a first cylinder section (135) and a second cylinder section (136); the first cylinder section (135) is located outside the valve seat cavity (1), and the second cylinder section (136) is located inside the valve seat cavity (1);

-a valve needle (20), the outer wall of the valve needle (20) being adapted to the inner wall of the second barrel section (136), at least part of the valve needle (20) being movably arranged to the support frame (130), a limit structure (60) being arranged between the first barrel section (135) and the valve needle (20) such that rotation of the valve needle (20) in the circumferential direction is limited;

The screw rod (30) can rotate along the axis of the screw rod (30), the position of the screw rod (30) in the axial direction is unchanged, the screw rod (30) is matched with the valve needle (20) through a thread structure, and the valve needle (20) is driven by the screw rod (30) to approach or be far away from the valve port (121);

the driving mechanism (50) comprises a rotor (51), and the rotor (51) is fixedly connected with the screw rod (30) so as to drive the screw rod (30) to rotate;

the shell (100) is fixedly connected with the valve seat (10) and is positioned above the valve seat (10), a containing cavity (2) is formed in the shell (100), the rotor (51), the screw rod (30) and the first barrel section (135) are all positioned in the containing cavity (2), and the top end of the screw rod (30) is in butt fit with the top wall of the shell (100).

2. The electronic expansion valve according to claim 1, wherein one of the first barrel section (135) and the valve needle (20) is provided with a protruding structure (150), the other of the first barrel section (135) and the valve needle (20) is provided with a first groove (160), the protruding structure (150) and the first groove (160) form the limit structure (60), and the protruding structure (150) is axially movable along the first groove (160).

3. The electronic expansion valve of claim 2, wherein a top portion of the first barrel section (135) is provided with a downwardly extending elongated slot forming the first recess (160).

4. The electronic expansion valve according to claim 2, characterized in that the top of the side wall of the valve needle (20) is provided with a first mounting hole (213), the protruding structure (150) is a pin, which is inserted into the first mounting hole (213), and a part of the pin protrudes from the side wall of the valve needle (20) and cooperates with the first recess (160).

5. The electronic expansion valve according to claim 4, wherein the valve needle (20) comprises a valve needle body (21) and a first sealing structure (22) arranged at the bottom of the valve needle body (21), the valve needle (20) is in a fully closed state, the first sealing structure (22) is in abutting fit with the valve port (121), the valve needle body (21) comprises a valve needle top wall (211) and a valve needle side wall (212), a second mounting hole (214) extending downwards is arranged on the valve needle top wall (211), the thread structure is arranged on the inner wall of the second mounting hole (214), the screw rod (30) is arranged in the second mounting hole (214) in a penetrating mode and is matched with the thread structure, and the first mounting hole (213) is arranged at the top of the valve needle side wall (212) and extends inwards.

6. The electronic expansion valve of claim 1, further comprising:

The support frame cover (240) is arranged at the top of the first cylinder section (135), and a guide part is arranged on the support frame cover (240) and provides a guide function for the screw rod (30).

7. The electronic expansion valve according to claim 6, wherein the guide portion is a guide cylinder (242) disposed on the support frame cover (240) and extending upwards, a part of the screw rod (30) is arranged in the guide cylinder (242) in a penetrating manner, a step surface (32) is disposed on a side wall of the screw rod (30), and a top surface of the guide cylinder (242) is in abutting fit with the step surface (32).

8. The electronic expansion valve of claim 1, wherein,

The driving mechanism (50) further comprises a coil (52), and the rotor (51) drives the screw rod (30) to rotate through the coil (52).

9. The electronic expansion valve according to claim 1, characterized in that a second sealing structure (140) is arranged between the second barrel section (136) and the valve needle (20).

10. The electronic expansion valve according to claim 9, characterized in that the bottom of the inner wall of the second cylinder section (136) is provided with an annular groove (137), the second sealing structure (140) being a sealing ring arranged in the annular groove (137).

11. The electronic expansion valve according to claim 1, characterized in that an annular protruding edge (138) is arranged on the outer wall of the supporting frame (130), the annular protruding edge (138) is located at the connection position of the first cylinder section (135) and the second cylinder section (136), and the lower surface of the annular protruding edge (138) is abutted with the upper surface of the valve seat (10).

12. The electronic expansion valve according to any of claims 1 to 11, wherein the support frame (130) is of an integrally formed construction.