CN114673793A

CN114673793A - Electronic expansion valve

Info

Publication number: CN114673793A
Application number: CN202011552743.1A
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2022-06-28

Abstract

The invention relates to an electronic expansion valve, which comprises a valve seat, a nut component and a screw rod valve needle component, wherein the valve seat is fixedly connected with the nut component, the valve seat comprises a valve opening part and a guide part, the screw rod valve needle component comprises a screw rod and a valve needle, the screw rod is in limit connection or fixed connection with the valve needle, the valve needle is in sliding fit with the guide part, part of the screw rod is in threaded fit in the nut component, and the screw rod valve needle component can perform axial lifting motion to be close to or far away from the valve opening part under the action of threaded fit; the valve seat is provided with a first stop part, the valve needle screw rod assembly is provided with a second stop part, and when the first stop part abuts against the second stop part, a gap is reserved between the end sealing surface of the valve needle and the valve port part; or the nut component is provided with a first stop part, the valve needle screw rod component is provided with a second stop part, and when the first stop part abuts against the second stop part, a gap is reserved between the end sealing surface of the valve needle and the valve port part. The overall structure is relatively simple while having a small flow rate in the fully closed state.

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 comprises a valve seat, a nut component, a valve needle and a screw rod, wherein the valve seat is provided with a valve port part, the valve needle is matched with the valve port part, the valve seat and the nut component are relatively fixed, and the screw rod can rotate relative to the nut component and drive the valve needle to move along the axial direction of the valve needle so as to adjust the opening degree of the valve port part.

Depending on the system or customer requirements, a small flow regulation condition is still required when the electronic expansion valve is in the fully closed state.

Disclosure of Invention

The invention aims to provide an electronic expansion valve with a novel structure, which has small flow in a full-closed state and has a relatively simple integral structure.

In order to solve the technical problems, the invention provides an electronic expansion valve, which comprises a valve seat, a nut component and a screw rod valve needle component, wherein the valve seat is fixedly connected with the nut component, the valve seat comprises a valve opening part and a guide part, the screw rod valve needle component comprises a screw rod and a valve needle, the screw rod is in limit connection or fixed connection with the valve needle, the valve needle is in sliding fit with the guide part, part of the screw rod is positioned in the nut component, the screw rod is in threaded fit with the nut component, and the screw rod valve needle component can perform axial lifting motion to be close to or far away from the valve opening part under the action of threaded fit; the valve seat is provided with a bulge, the bulge is provided with a guide hole, the inner wall of the guide hole forms the guide part, the upper end surface of the bulge forms a first stop part, the valve needle screw rod assembly is provided with a second stop part, and when the first stop part abuts against the second stop part, a gap is reserved between the end sealing surface of the valve needle and the valve port part; alternatively, the nut member may be provided with a first stopper portion projecting in a substantially radial direction toward an axial direction of the nut member, and the needle screw assembly may be provided with a second stopper portion, and when the first stopper portion abuts against the second stopper portion, a gap may be left between the end sealing surface of the needle and the valve port portion.

When the first stop part and the second stop part are abutted, the electronic expansion valve is in a full-closed state, a gap is left between the end sealing surface of the valve needle and the valve port part, and the electronic expansion valve can still have flow. The first stop part can be arranged on the valve seat and can also be arranged on the nut component, the second stop part is arranged on the valve needle lead screw component, the movement of the valve needle lead screw component is limited by the arrangement of the two stop parts (the first stop part and the second stop part), so that the electronic expansion valve can achieve the purpose of flow under the full-closed state, the whole structure is simple, the butt connection cooperation of the two stop parts can ensure the flow precision under the full-closed state, and the user requirement is met.

Drawings

Fig. 1 is a schematic structural diagram of an electronic expansion valve according to an embodiment of the present invention;

FIG. 2 is an enlarged view of A in FIG. 1;

FIG. 3 is a schematic view of the configuration of the valve port and end seal faces in a fully closed condition;

FIG. 4 is a schematic view of the valve seat and boss configuration;

FIG. 5 is a schematic view of the structure of the nut member;

6-7 are schematic structural views of the action assembly;

fig. 8-12 are schematic structural views of the electronic expansion valve with different first and second stop portions.

In the accompanying fig. 1-12, the reference numerals are illustrated as follows:

1-valve seat, 11-valve port;

2-nut component, 21-large diameter section and 22-small diameter section;

3-valve needle, 31-end sealing surface, 32-limit projection;

4-a screw rod;

5-a first stop portion;

6-a second stop portion;

7-boss, 71-guide hole, 72-guide;

8-connecting piece, 81-cylinder, 82-first flanging and 83-second flanging;

9-clearance;

l1 — first distance; l2 — second distance; d1-diameter of valve mouth; d2-diameter of end seal face.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

The embodiment of the invention provides an electronic expansion valve, as shown in fig. 1, the electronic expansion valve comprises a valve seat 1, a nut member 2 and a lead screw valve rod assembly, wherein the valve seat 1 is fixedly connected with the nut member 2, the valve seat 1 comprises a valve opening portion 11 and a guide portion 72, the lead screw valve needle assembly comprises a lead screw 4 and a valve needle 3, the lead screw 4 is in limit connection or fixed connection with the valve needle 3, wherein the fixed connection means that the lead screw 4 and the valve needle 3 are relatively fixed, the limit connection means that the lead screw 4 and the valve needle 3 cannot relatively move along an axial direction but can relatively rotate, the valve needle 3 is in sliding fit with the guide portion 72, part of the lead screw 4 is positioned in the nut member 2, the lead screw 4 is in threaded fit with the nut member 2, and the valve needle assembly can axially lift to approach or be far away from the valve opening portion 11 through the action of threaded fit, thereby adjusting the opening degree of the valve port portion 11.

Specifically, when the screw 4 rotates relative to the nut member 2, and the valve needle 3 can be driven to move relative to the valve seat 1 along the axial direction of the screw 4 to the fully closed state (as shown in fig. 2), a gap 9 (as shown in fig. 3) still remains between the end sealing surface 31 of the valve needle 3 and the valve port 11, that is, the end sealing surface 31 does not seal the valve port 11, and the electronic expansion valve can still have flow.

The electronic expansion valve specifically comprises the following schemes that a valve seat 1 is provided with a bulge part 7, the bulge part 7 is provided with a guide hole 71, the inner wall of the guide hole 71 is provided with the guide part 72, the upper end surface of the bulge part 7 is provided with a first stop part 5, a valve needle screw rod assembly is provided with a second stop part 6, when a screw rod 4 rotates relative to a nut component 2 and drives the valve needle screw rod assembly to move to the first stop part 5 and the second stop part 6 to abut against each other, the electronic expansion valve is in a full-closed state, a gap 9 is reserved between an end sealing surface 31 of a valve needle 3 and a valve port part 11, and the electronic expansion valve can still have flow; in the second solution, the nut member 2 is provided with a first stop portion 5, the first stop portion 5 protrudes in the axial direction of the nut member 2 in a substantially radial direction (i.e., protrudes inward in the radial direction of the nut member 2), the needle screw assembly is provided with a second stop portion 6, when the screw 4 rotates relative to the nut member 2 and drives the needle screw assembly to move to the first stop portion 5 and the second stop portion 6 to abut against each other, the electronic expansion valve is in a fully closed state, a gap 9 is left between the end sealing surface 31 of the needle 3 and the valve port 11, and the electronic expansion valve can still have a flow rate.

That is to say, the first stop portion 5 can be disposed on the valve seat 1 or on the nut member 2, the second stop portion 6 is disposed on the valve needle screw rod assembly, and the movement of the valve needle screw rod assembly is limited by the two stop portions (the first stop portion 5 and the second stop portion 6), so that the electronic expansion valve can achieve the purpose of flow rate in the fully closed state.

Further, the diameter D1 of the end sealing surface 31 is not greater than the diameter D2 of the valve port 11, the axial distance between the first stop portion 5 and the valve port 11 is a first distance L1, the axial distance between the second stop portion 6 and the end sealing surface 31 is a second distance L2, and the first distance L1 is not less than a second distance L2. This arrangement ensures that in the fully closed state, there is still a gap 9 between the end sealing surface 31 and the valve port 11, and the electronic expansion valve still has a flow rate.

In this embodiment, the specific structure and the installation position of the first stop portion 5 and the second stop portion 6 are not limited as long as the electronic expansion valve is in a fully closed state when the first stop portion 5 is in abutting engagement with the second stop portion 6, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

Specifically, for the first stopper portion 5, the present embodiment provides the following three setting modes:

first, as shown in fig. 2, the first stopper 5 is formed on the upper end surface of the boss 7, and the axial distance from the upper end surface of the boss 7 to the valve port 11 is a first distance L1;

secondly, as shown in fig. 5, the nut member 2 includes a large diameter section 21 and a small diameter section 22, wherein the inner diameter of the large diameter section 21 is larger than the inner diameter of the small diameter section 22, the large diameter section 21 can be screw-engaged with the screw rod 4, the small diameter section 22 is located on the side of the large diameter section facing the valve seat 1, the first stopper 5 is formed on the end surface of the inner wall of the small diameter section 22 facing the large diameter section 21 (i.e., the upper end surface of the small diameter section 22), and the axial distance from the upper end surface of the small diameter section 22 to the valve port 11 is a first distance L1;

thirdly, a limiting member is disposed on the inner wall of the nut member 2, the first stopping portion 5 is formed on the upper end surface of the limiting member, and the axial distance from the upper end surface of the limiting member to the valve port 11 is a first distance L1;

fourthly, the end of the nut member 2 facing the valve seat 1 is further provided with a connecting piece 8, specifically, as shown in fig. 11 and 12, the connecting piece 8 includes a cylinder 81, the cylinder 81 is sleeved outside the bottom of the nut member 2, the bottom end of the cylinder 81 is provided with a first flange 82 radially outward, the upper end surface of the first flange 82 forms the first stop portion 5, and the axial distance from the upper end surface of the first flange 82 to the valve port 11 is the first distance L1.

For the second stopper portion 6, the present embodiment provides two arrangements as follows:

first, as shown in fig. 6, a limit protrusion 32 is circumferentially provided on an outer wall of one end of the needle 3 facing the screw 4, the second stopper 6 is formed on a lower end surface of the limit protrusion 32, and an axial distance from the lower end surface of the limit protrusion 32 to the end sealing surface 31 is a second distance L2;

secondly, as shown in fig. 7, the diameter of the screw 4 is larger than that of the needle 3, the second stopper 6 is formed on the lower end surface of the screw 4, and the axial distance from the lower end surface of the screw 4 to the end sealing surface 31 is a second distance L2.

Any combination of the four types of arrangement of the first stopper portion 5 and the two types of arrangement of the second stopper portion 6 is not particularly limited, and the following combinations will be described in detail.

As shown in fig. 2, the upper end surface of the boss 7 forms a first stop portion 5, the lower end surface of the limit projection 32 forms the second stop portion 6, and when the screw rod 4 rotates relative to the nut member 2 and drives the valve needle 3 to move along the axial direction thereof until the lower end surface of the limit projection 32 abuts against and engages with the upper end surface of the limit hole 71, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

As shown in fig. 8, the upper end surface of the boss 7 forms the first stopper 5, the lower end surface of the screw 4 forms the second stopper 6, the screw 4 rotates relative to the nut member 2 and drives the needle 3 to move along the axial direction thereof until the lower end surface of the screw 4 abuts against and engages with the upper end surface of the stopper hole 71, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

Specifically, in the present embodiment, the upper end surface of the boss 7 may directly form the first stopper 5, or an abutting member may be further provided on the upper end surface of the boss 7 for abutting against the second stopper 6, and the abutting member may form the first stopper structure 5, which is not limited in particular.

As shown in fig. 9, the nut member 2 includes a large diameter section 21 and a small diameter section 22, the first stop portion 5 is formed on the upper end surface of the small diameter section 22, the second stop portion 6 is formed on the lower end surface of the limit protrusion 32, the screw rod 4 rotates relative to the nut member 2 and drives the needle 3 to move along the axial direction thereof until the lower end surface of the limit protrusion 32 abuts against and engages with the upper end surface of the small diameter section 22, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

As shown in fig. 10, the nut member 2 includes a large diameter section 21 and a small diameter section 22, the first stop portion 5 is formed on the upper end surface of the small diameter section 22, the second stop portion 6 is formed on the lower end surface of the screw rod 4, the screw rod 4 rotates relative to the nut member 2 and drives the needle 3 to move along the axial direction thereof until the lower end surface of the screw rod 4 abuts against and engages with the upper end surface of the small diameter section 22, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

The upper end surface of the limiting part forms a first stop part 5, the lower end surface of the limiting protrusion 32 forms the second stop part 6, the screw rod 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along the axial direction thereof until the lower end surface of the limiting protrusion 32 is abutted and matched with the upper end surface of the limiting part, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

The upper end face of the limiting part forms a first stop part 5, the lower end face of the screw rod 4 forms a second stop part 6, the screw rod 4 rotates relative to the nut part 2 and drives the valve needle 3 to move along the axial direction thereof until the lower end face of the screw rod 4 is abutted and matched with the upper end face of the limiting part, the electronic expansion valve is in a fully closed state, and a gap 9 is reserved between the end sealing surface 31 and the valve port part 11.

Specifically, in this embodiment, the specific structure of the limiting member disposed in the nut member 2 is not limited, and specifically, the limiting member may be a plurality of limiting blocks disposed at intervals in the circumferential direction of the inner wall of the nut member 2, or the limiting member may be an annular structure disposed continuously in the circumferential direction of the inner wall of the nut member 2.

As shown in fig. 11, the upper end surface of the first flange 82 of the connecting member 8 forms the first stop portion 5, the lower end surface of the limit protrusion 32 forms the second stop portion 6, the screw rod 4 rotates relative to the nut member 2 and drives the valve needle 3 to move along the axial direction thereof until the lower end surface of the limit protrusion 32 abuts against and is matched with the upper end surface of the first flange 82, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

As shown in fig. 12, the first stop portion 5 is formed at the upper end surface of the first flange 82 of the connecting member 8, the second stop portion 6 is formed at the lower end surface of the screw rod 4, and when the screw rod 4 rotates relative to the nut member 2 and drives the valve needle 3 to move along the axial direction thereof until the lower end surface of the screw rod 4 abuts against and engages with the upper end surface of the first flange 82, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port 11.

Further, as shown in fig. 12, one end of the cylinder 81, which is far away from the first flange 82, is provided with a second flange 83 along a radial direction thereof, the second flange 83 is clamped and fixed between the top end of the boss 7 and the nut member 2, specifically, the outer wall of the nut member 2 is further provided with a step structure, and the second flange 82 is clamped between a step surface of the step structure and the top end of the boss 7. In this embodiment, the fixing manner between the cylinder 81 and the boss 7 and the fixing manner between the cylinder 81 and the nut member 2 are not limited, and the second flange 83 is provided to facilitate the fixing operation, such as welding. Alternatively, the inner wall of the cylindrical body 81 and the outer wall of the nut member 2 may be fixed by interference fit, and the outer wall of the cylindrical body 81 and the boss portion 7 may be fixed by interference fit or welding.

Specifically, the first flange 82 and the second flange 83 are both annular structures continuously arranged along the circumferential direction of the cylinder 81, and of course, the first flange 82 can also be arranged to include at least two block-shaped structures arranged along the circumferential direction of the cylinder 81, or the second flange 83 can be arranged to include at least two block-shaped structures arranged along the circumferential direction of the cylinder 81, or the first flange 82 and the second flange 83 are both block-shaped structures, and no specific limitation is made here, and when the first flange 82 and the second flange 83 are both arranged to be annular structures, the stable installation stress can be ensured, and the overall structure is more regular.

In the above embodiment, the specific structure of the position-limiting protrusion 32 provided on the outer wall of the valve needle 3 is not limited, and in the present embodiment, the position-limiting protrusion is provided as an annular structure disposed along the circumferential direction of the valve needle 3, and of course, it may be provided as at least two protrusions disposed along the interval of the valve needle 3. The structure of the annular bulge is convenient to process, and the matching stability of the two stop parts can be ensured.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. An electronic expansion valve is characterized by comprising a valve seat (1), a nut component (2) and a screw rod valve needle assembly, wherein the valve seat (1) is fixedly connected with the nut component (2), the valve seat (1) comprises a valve opening part (11) and a guide part (72), the screw rod valve needle assembly comprises a screw rod (4) and a valve needle (3), the screw rod (4) is in limit connection or fixed connection with the valve needle (3), the valve needle (3) is in sliding fit with the guide part (72), part of the screw rod (4) is positioned in the nut component (2), the screw rod (4) is in threaded fit with the nut component (2), and the screw rod valve needle assembly can perform axial lifting motion to be close to or far away from the valve opening part (11) through the threaded fit effect;

the valve seat (1) is provided with a bulge (7), the bulge (7) is provided with a guide hole (71), the inner wall of the guide hole (71) forms the guide part (72), the upper end face of the bulge (7) forms a first stop part (5), the valve needle screw rod assembly is provided with a second stop part (6), and when the first stop part (5) abuts against the second stop part (6), a gap (9) is reserved between the end sealing surface (31) of the valve needle (3) and the valve port part (11);

or the nut component (2) is provided with a first stop part (5), the first stop part (5) approximately protrudes to the axial direction of the nut component (2) along the radial direction, the valve needle screw rod component is provided with a second stop part (6), and when the first stop part (5) is abutted against the second stop part (6), a gap is reserved between the end sealing surface (31) of the valve needle (3) and the valve port part (11).

2. The electronic expansion valve of claim 1, wherein the diameter of the end sealing surface (D2) is no greater than the diameter of the valve mouth (D1);

the axial distance between the first stop portion (5) and the valve port portion (11) is a first distance (L1), the axial distance between the second stop portion (6) and the end seal surface (31) is a second distance (L2), and the first distance (L1) is not less than the second distance (L2).

3. The electronic expansion valve according to claim 1, wherein a connecting member (8) is further provided at an end of the nut member (2) facing the valve seat (1), the connecting member (8) comprises a cylindrical body (81) sleeved outside a bottom of the nut member (2), a first flange (82) is provided at a bottom end of the cylindrical body (81) along a radially inward direction thereof, and an upper end surface of the first flange (82) forms the first stop portion (5).

4. An electronic expansion valve according to claim 3, wherein the top end of the cylinder (81) is provided with a second turned-up edge (83) radially outwardly, and the second turned-up edge (83) is sandwiched and fixed between the top end of the boss portion (7) and the nut member (2).

5. An electronic expansion valve according to claim 4, wherein the first and second flanges (82, 83) are each an annular structure provided along the circumferential direction of the cylinder (81).

6. An electronic expansion valve according to claim 1, wherein the nut member (2) comprises a large diameter section (21) and a small diameter section (22), the large diameter section (21) has a larger inner diameter than the small diameter section (22), the large diameter section (21) is screw-fitted to the lead screw (4), the small diameter section (22) is located on a side of the large diameter section (21) facing the valve seat (1), and a side end surface of an inner wall of the small diameter section (22) facing the large diameter section (21) forms the first stopper portion (5).

7. An electronic expansion valve according to claim 1, wherein the inner wall of the nut member (2) is provided with a stopper, an upper end surface of which forms the first stopper portion (5).

8. An electronic expansion valve according to any of claims 1-7, wherein the outer wall of the valve needle (3) is provided with a limit protrusion (32) along the circumferential direction, the screw (4) can drive the valve needle (3) to move along the axial direction thereof until the limit protrusion (32) abuts against the first stop portion (5), and the lower end surface of the limit protrusion (32) forms the second stop portion (6).

9. An electronic expansion valve according to claim 8, wherein the stop protrusion (32) is an annular structure arranged circumferentially along the outer wall of the valve needle (3).

10. An electronic expansion valve according to any of claims 1-7, characterized in that the diameter of the valve needle (3) is smaller than the diameter of the screw (4), and the lower end face of the screw (4) forms the second stop (6).