CN214171340U

CN214171340U - Valve needle assembly, electronic expansion valve and refrigeration equipment

Info

Publication number: CN214171340U
Application number: CN202023026609.6U
Authority: CN
Inventors: 杨茂; 黄龙华; 陈超; 江波
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-09-10
Anticipated expiration: 2030-12-14

Abstract

The utility model discloses a valve needle subassembly, electronic expansion valve and refrigeration plant, wherein, the valve needle subassembly includes valve needle cover, valve rod, valve needle, cushion slide and buffer spring, the valve needle cover has relative first open end and second open end; the valve rod is provided with a driving end, and the driving end of the valve rod is movably matched with the valve needle sleeve through the first opening end so as to drive the valve needle to move; the valve needle is arranged at the second opening end of the valve needle sleeve; the buffer sliding block is arranged in the valve needle sleeve and is abutted against the valve needle; the buffer spring is arranged in the valve needle sleeve, and the driving end of the valve rod is connected with the buffer sliding block through the buffer spring. The utility model discloses a needle subassembly can effectively avoid needle and valve port to take place wearing and tearing, thereby improves the life of needle subassembly has improved electronic expansion valve's reliability.

Description

Valve needle assembly, electronic expansion valve and refrigeration equipment

Technical Field

The utility model relates to a control valve technical field, in particular to needle subassembly, electronic expansion valve and refrigeration plant.

Background

At present, an electronic expansion valve utilizes the principle of a stepping motor, a coil drives a magnetic rotor to rotate, the rotary motion of the magnetic rotor is converted into the axial motion of a valve rod, and the valve rod drives a valve needle connected with the valve rod to ascend or descend so as to control the flow rate of the electronic expansion valve.

In the related art, an electronic expansion valve mainly comprises a rotor, a valve rod, a nut and a valve needle, wherein the valve rod is rotatably connected with the nut, the valve needle is arranged at the lower end of the valve rod, and the rotor drives the valve rod to move axially so as to drive the valve needle to move axially, so that the purposes of plugging and opening the valve port are achieved. However, with the above structure, when the valve port is blocked and opened, the valve needle rotates relative to the valve port, so that the valve needle and the valve port are abraded, and the service life of the valve needle is shortened.

The above is only for the purpose of assisting understanding of the technical solution of the present invention, and does not represent an admission that the above is the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims at providing a valve needle subassembly aims at solving among the prior art technical problem that the valve needle can take place to rotate relative valve port and lead to the valve needle to take place wearing and tearing easily.

In order to achieve the above object, the utility model provides a valve needle subassembly for electronic expansion valve, the valve needle subassembly includes:

a valve needle sleeve having opposing first and second open ends;

the valve rod is provided with a driving end, and the driving end of the valve rod is movably matched with the valve needle sleeve through the first opening end so as to drive the valve needle to move;

the valve needle is arranged at the second opening end of the valve needle sleeve;

the buffer sliding block is arranged in the valve needle sleeve and is abutted against the valve needle; and

and the buffer spring is arranged in the valve needle sleeve, and the driving end of the valve rod is connected with the buffer sliding block through the buffer spring.

In an embodiment, a flange portion is disposed on a peripheral wall of the driving end of the valve rod, the flange portion is located in the valve needle sleeve, a constricted portion abutting against the flange portion is disposed at the first opening end of the valve needle sleeve, and one end of the buffer spring is sleeved on the driving end of the valve rod and abuts against the flange portion.

In one embodiment, a positioning column is disposed on one side of the buffer slider facing the valve rod, and the other end of the buffer spring is sleeved on the positioning column and abuts against the buffer slider.

In one embodiment, the cross-sectional diameter of the valve needle sleeve is greater than the cross-sectional diameter of the flange portion.

In one embodiment, the buffer slide block has a protrusion protruding toward the valve needle, and the buffer slide block abuts against the valve needle through the protrusion.

In one embodiment, the surface of the protrusion is a cambered surface.

In one embodiment, the inner diameter of the valve needle sleeve is larger than the outer diameter of the buffer slide block.

In one embodiment, the outer wall surface of the buffer sliding block is provided with a limiting convex part, and the limiting convex part is arranged along the circumferential direction of the buffer sliding block.

In one embodiment, the number of the limiting convex parts is at least two, and the at least two limiting convex parts are distributed at intervals along the circumferential direction of the buffer sliding block;

or the limiting convex part is an annular rib extending along the circumferential direction of the buffer sliding block.

In one embodiment, the second open end of the needle sleeve is open, and the outer wall surface of the needle is in interference fit with the open end.

In one embodiment, the buffer spring is a compression spring.

In one embodiment, the buffer slide block is made of plastic.

The utility model also provides an electronic expansion valve, which comprises a nut and a valve needle component, wherein the nut is provided with a mounting hole; the valve needle assembly comprises:

a valve needle sleeve having opposing first and second open ends;

the valve rod penetrates through the mounting hole and is in threaded connection with the nut, the valve rod is provided with a driving end, and the driving end of the valve rod is movably matched with the valve needle sleeve through the first opening end so as to drive the valve needle to move;

In an embodiment, the electronic expansion valve further includes a valve seat and a valve core seat, the valve core seat is disposed on the valve seat and is provided with a valve port, the valve needle is detachably mounted on the valve port, the nut is connected to the valve seat, and the nut extends toward the valve core seat to be close to or abutted against the valve core seat.

In one embodiment, a coolant passage is formed in a peripheral side wall of one end of the nut, which is close to the valve core seat.

The utility model also provides a refrigeration device, which comprises an electronic expansion valve, wherein the electronic expansion valve comprises a nut and a valve needle component, and the nut is provided with a mounting hole; the valve needle assembly comprises:

a valve needle sleeve having opposing first and second open ends;

The valve needle assembly of the utility model comprises a valve needle sleeve, a valve rod, a valve needle, a buffer slide block and a buffer spring, wherein the valve needle sleeve is provided with a first opening end and a second opening end which are opposite; the valve rod is provided with a driving end, the valve rod is arranged in the first opening end in a penetrating mode, and the driving end of the valve rod is movably matched with the valve needle sleeve through the first opening end to drive the valve needle to move; the valve needle is arranged at the second opening end of the valve needle sleeve; the buffer sliding block is arranged in the valve needle sleeve and is abutted against the valve needle; the buffer spring is arranged in the valve needle sleeve, and the driving end of the valve rod is connected with the buffer sliding block through the buffer spring. Therefore, when the valve needle is opened to the first position (namely the position where the contact force between the valve port and the valve needle is equal to the pressure of the refrigerant) from the fully closed state, the valve needle and the valve port are always in sealing contact, the valve rod drives the buffer spring and the buffer slide block to rotate together, and the valve needle is kept still; when the valve needle is continuously opened to the second position (namely the position of the valve opening pulse point), the valve needle and the valve port are continuously kept in sealing contact at first, and the valve needle can move along with the valve rod after the valve rod moves to be abutted with the valve needle sleeve along the axial direction. Therefore, the utility model discloses a needle subassembly greatly reduced the wearing and tearing between needle and the valve port, prolonged the life of needle subassembly, improved electronic expansion valve's reliability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic view of an internal structure of an embodiment of an electronic expansion valve according to the present invention;

FIG. 2 is a schematic diagram of a portion of the electronic expansion valve of FIG. 1;

FIG. 3 is a schematic structural view of one embodiment of the valve needle assembly of FIG. 2;

fig. 4 is a partially enlarged view of a portion a in fig. 3.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)	Reference numerals	Name (R)
						200	Electronic expansion valve	100	Valve needle assembly	140	Buffer slide block
210	Outer cover	110	Valve rod	141	Positioning column
						220	Valve seat	111	Drive end	142	Projection
230	Valve core seat	112	Flange part	143	Limiting convex part
						231	Valve port	120	Valve needle sleeve	150	Valve needle
240	Nut	121	First open end	151	Main body part
						241	Mounting hole	122	Necking down part	152	Mounting part
242	Refrigerant passing port	123	Second open end
						250	Magnetic rotor	130	Buffer spring

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

It should be noted that if the embodiments of the present invention are described with reference to "first", "second", etc., the description of "first", "second", etc. is only for descriptive purposes and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B" including either scheme A, or scheme B, or a scheme in which both A and B are satisfied.

The utility model provides an electronic expansion valve.

Referring to fig. 1, 2 and 3, the electronic expansion valve 200 of the present invention includes a valve body including a housing 210, a valve seat 220 fixedly connected to the housing 210, a magnetic rotor 250 rotatable in the housing 210, a nut 240, and a valve needle assembly 100. The outer cover 210 and the valve seat 220 enclose to form a valve cavity, the magnetic rotor 250, the nut 240 and the valve needle assembly 100 are all arranged in the valve cavity, the nut 240 is connected with the valve seat 220, and the magnetic rotor 250 drives the valve needle assembly 100 to move so as to control the flow rate of the electronic expansion valve 200.

The structure of the valve pin assembly 100 will now be described.

Referring to fig. 1, 2 and 3, the present invention provides a valve needle assembly 100 for an electronic expansion valve 200, wherein the valve needle assembly 100 includes a valve needle sleeve 120, a valve rod 110, a valve needle 150, a buffer slide block 140 and a buffer spring 130. The needle hub 120 has opposite first and second

open ends

121 and 123; the valve rod 110 has a driving end 111, the valve rod 110 is disposed through the first opening end 121, and the driving end 111 of the valve rod 110 is movably matched with the valve needle sleeve 120 through the first opening end 121 to drive the valve needle 150 to move; the valve needle 150 is mounted to the second open end 123 of the valve needle sleeve 120; the buffer slide block 140 is arranged in the valve needle sleeve 120, and the buffer slide block 140 is abutted to the valve needle 150; the buffer spring 130 is arranged in the valve needle sleeve 120, and the driving end 111 of the valve rod 110 is connected with the buffer sliding block 140 through the buffer spring 130.

Specifically, the nut 240 has an installation hole 241 extending in the axial direction thereof, and the stem 110 is inserted into the installation hole 241 and screwed to the nut 240. Valve rod 110 includes guide rod section and screw thread pole section, mounting hole 241 include with the guide hole section of guide rod section adaptation, and with the screw thread hole section of screw thread pole section adaptation, the guide rod section with be interference fit or clearance fit between the guide hole section, the screw thread pole section with be screw thread fit between the screw thread hole section. The valve seat 220 is provided with a valve core seat 230, the valve core seat 230 is provided with a valve port 231 corresponding to the valve needle 150, and the valve needle 150 is detachably installed in the valve port 231. In this way, the magnetic rotor 250 is driven by the coil to rotate, the rotation of the magnetic rotor 250 can be converted into the axial movement of the valve rod 110, and the valve rod 110 drives the valve needle 150 connected with the valve rod to ascend or descend, thereby controlling the flow rate of the electronic expansion valve 200.

In the embodiment of the present invention, the valve stem 110, the nut 240 and the valve needle 150 are coaxially disposed. The valve stem 110 has a driving end 111 near the valve needle 150, the valve stem 110 is arranged through the first opening end 121 of the valve needle sleeve 120, and the driving end 111 of the valve stem 110 is located in the valve needle sleeve 120. The driving end 111 of the valve stem 110 is in clearance fit with the first open end 121 of the valve needle housing 120 such that the valve stem 110 is axially movable relative to the valve needle housing 120 along the same. The valve needle 150 is mounted at the second opening end 123 of the valve needle sleeve 120, and the valve needle 150 is in interference fit with the second opening end 123 of the valve needle sleeve 120. The buffer spring 130 and the buffer slider 140 are both located in the valve needle sleeve 120, the buffer slider 140 is opposite to and spaced from the driving end 111 of the valve stem 110, and the buffer spring 130 is disposed between the buffer slider 140 and the driving end 111 of the valve stem 110 to connect the buffer slider 140 and the driving end 111 of the valve stem 110. Specifically, the buffer spring 130 is a compression spring. In this way, when the valve stem 110 moves axially relative to the valve needle sleeve 120, the valve stem 110 can drive the buffer slider 140 to rotate through the buffer spring 130, and the valve needle 150 remains stationary, so as to avoid abrasion caused by rotation of the valve needle 150 relative to the valve port 231. After the valve rod 110 moves along the axial direction thereof to abut against the valve needle sleeve 120, the valve rod 110 can drive the valve needle 150 to move together through the valve needle sleeve 120, so as to control the opening degree of the valve port 231, that is, control the flow rate of the electronic expansion valve 200. Optionally, the valve stem 110, the buffer spring 130, the buffer slide block 140 and the valve needle sleeve 120 are coaxially arranged, so that good coaxiality of the valve needle assembly 100 can be ensured.

In the embodiment of the present invention, the buffer sliding block 140 abuts against the valve needle 150, so that the buffer sliding block 140 is opposite to the valve needle 150, and thus the valve needle 150 is prevented from rotating relative to the valve port 231, and the valve needle 150 is prevented from being worn. The cushion slide 140 may be made of a material with high lubricity, so that the friction between the cushion slide 140 and the valve needle 150 may be reduced, thereby reducing the wear caused by the rotation of the cushion slide 140 relative to the valve needle 150. Optionally, the buffer sliding block 140 is made of a non-metal material, for example, but not limited to, the buffer sliding block 140 is made of a plastic material. Specifically, the plastic material is polyphenylene sulfide (PPS). By using the non-metallic buffer sliding block 140, the friction between the buffer sliding block 140 and the metal valve needle 150 can be reduced, and the abrasion caused by the rotation of the buffer sliding block 140 relative to the valve needle 150 can be reduced.

The valve needle assembly 100 of the present invention comprises a valve needle sleeve 120, a valve rod 110, a valve needle 150, a buffer slide block 140 and a buffer spring 130, wherein the valve needle sleeve 120 has a first opening end 121 and a second opening end 123 which are opposite; the valve rod 110 has a driving end 111, the valve rod 110 is disposed through the first opening end 121, and the driving end 111 of the valve rod 110 is disposed in the valve needle sleeve 120; the valve needle 150 is mounted to the second open end 123 of the valve needle sleeve 120; the buffer slide block 140 is arranged in the valve needle sleeve 120, and the buffer slide block 140 is abutted to the valve needle 150; the buffer spring 130 is arranged in the valve needle sleeve 120, and the driving end 111 of the valve rod 110 is connected with the buffer sliding block 140 through the buffer spring 130. In this way, when valve needle 150 is opened from the fully closed state to the first position (i.e. the position where the contact force between valve port 231 and valve needle 150 is equal to the pressure of the refrigerant), valve needle 150 and valve port 231 are always kept in sealing contact, valve stem 110 drives damping spring 130 and damping slider 140 to rotate together, and valve needle 150 is kept stationary; during the further opening of valve needle 150 to the second position (i.e. the position of the opening pulse point), valve needle 150 initially continues to maintain sealing contact with valve port 231, and valve needle 150 will follow valve stem 110 after valve stem 110 has moved axially into abutment with valve needle sleeve 120. Therefore, the utility model discloses a needle subassembly 100 greatly reduced the wearing and tearing between needle 150 and the valve port 231, prolonged the life of needle subassembly 100, improved electronic expansion valve 200's reliability.

It should be noted that, in an embodiment, the valve needle assembly 100 may only be composed of the valve needle sleeve 120, the valve stem 110, the valve needle 150, the buffer slide block 140 and the buffer spring 130, so that the valve needle assembly 100 has fewer parts and can achieve the effect of saving cost.

Referring to fig. 3 and 4, in an embodiment, a flange portion 112 is disposed on a peripheral wall of the driving end 111 of the valve stem 110, the flange portion 112 is located in the valve needle guard 120, a necking portion 122 abutting against the flange portion 112 is disposed at a first opening end 121 of the valve needle guard 120, and one end of the buffer spring 130 is sleeved on the driving end 111 of the valve stem 110 and abuts against the flange portion 112.

In this way, when the valve needle 150 is opened from the fully closed state to the first position (i.e. the position where the contact force between the valve port 231 and the valve needle 150 is equal to the pressure of the refrigerant), the valve needle 150 and the valve port 231 are always in sealing contact, a gap exists between the flange portion 112 and the constricted portion 122 of the valve needle sleeve 120, the valve rod 110 drives the buffer spring 130 and the buffer slider 140 to rotate together, and the valve needle 150 remains stationary; during the process that valve needle 150 continues to open to the second position (i.e., the position of the opening pulse point), valve needle 150 initially continues to maintain sealing contact with valve port 231, and valve needle 150 will follow valve stem 110 after valve stem 110 moves axially until flange portion 112 abuts neck portion 122 of needle sleeve 120 (i.e., the gap between flange portion 112 and neck portion 122 of needle sleeve 120 is zero).

In the present embodiment, the flange portion 112 is provided in a ring shape. Of course, it is understood that in other embodiments, the flange portion 112 may be disposed in an arc shape or a block shape, and is not limited in particular. The flange portion 112 may serve to fix the buffer spring 130, and prevent the driving end 111 of the stem 110 from coming out of the valve sleeve 120. In addition, in the present embodiment, the cross-sectional diameter of the valve needle sleeve 120 is larger than the cross-sectional diameter of the flange portion 112, so that the friction between the flange portion 112 and the inner wall surface of the valve needle sleeve 120 can be reduced, and the valve stem 110 can move smoothly relative to the valve needle sleeve 120.

Referring to fig. 3 and 4, a positioning post 141 is disposed on one side of the cushion slider 140 facing the valve stem 110, the positioning post 141 is disposed opposite to the driving end 111 of the valve stem 110 at an interval, and the other end of the cushion spring 130 is sleeved on the positioning post 141 and abuts against the cushion slider 140. In this way, by the positioning column 141, on one hand, the buffer spring 130 can be fixedly mounted, and on the other hand, the buffer spring 130 can also be positioned, so that the buffer spring 130 is ensured to move along the axial direction of the valve rod 110 without deviation.

Referring to fig. 4, in an embodiment, in order to further reduce a contact area between the buffer slide block 140 and the valve needle 150, so as to reduce wear caused when the buffer slide block 140 rotates relative to the valve needle 150, the buffer slide block 140 is provided with a protrusion 142 protruding toward the valve needle 150, and the buffer slide block 140 abuts against the valve needle 150 through the protrusion 142. Optionally, the surface of the protrusion 142 is a cambered surface. By providing the arc-shaped protrusion 142, on one hand, the contact area between the buffer sliding block 140 and the valve needle 150 can be reduced, and on the other hand, the arc-shaped protrusion 142 can play a good role of a fulcrum, so that the buffer sliding block 140 rotates around the fulcrum without position deviation, and the valve stem 110, the valve needle sleeve 120, the buffer spring 130 and the buffer sliding block 140 are ensured to always keep high coaxiality.

Referring to fig. 3 and 4, in one embodiment, the inner diameter of the needle sleeve 120 is larger than the outer diameter of the buffer sliding block 140. Therefore, the friction force between the buffer slide block 140 and the inner wall surface of the valve needle sleeve 120 can be reduced, so that the buffer slide block 140 can smoothly rotate relative to the valve needle sleeve 120.

In order to avoid the position deviation of the cushion slider 140 during the rotation process, a limiting protrusion 143 may be disposed on an outer wall surface of the cushion slider 140, and the limiting protrusion 143 may be disposed along the circumferential direction of the cushion slider 140. Thus, the position of the cushion slider 140 can be prevented from shifting during the rotation process by providing the position-limiting protrusion 143 for limiting the cushion slider 140.

In this embodiment, the limiting protrusion 143 and the buffering sliding block 140 are integrally formed; it is understood that, in other embodiments, the limit protrusion 143 and the buffer sliding block 140 may be provided separately, and are not limited herein. There are various structures of the limit protrusions 143, for example, in an embodiment, there are at least two limit protrusions 143, and at least two limit protrusions 143 are spaced apart from each other along the circumferential direction of the cushion slider 140. By providing the plurality of limit protrusions 143, the cushion slider 140 can be effectively prevented from being displaced. For another example, in another embodiment, the limit protrusion 143 is one, and the limit protrusion 143 is an annular rib extending along the circumferential direction of the cushion slider 140.

Referring to fig. 3 and 4, in an embodiment, the first opening end 121 of the valve needle sleeve 120 is a through hole penetrating through the upper end of the valve needle sleeve 120, and the driving end 111 of the valve stem 110 is in clearance fit with the through hole; the second open end 123 of the needle sleeve 120 is open, and the outer wall surface of the needle 150 is in interference fit with the open end. Of course, it is understood that in other embodiments, the second opening end 123 of the needle sleeve 120 may also be a through opening penetrating the lower end of the needle sleeve 120, and is not limited in particular.

In order to improve the connection sealing performance and reliability between the valve needle 150 and the valve needle sleeve 120, the valve needle 150 is welded to the second opening end 123 of the valve needle sleeve 120. Specifically, the valve needle 150 includes a main body 151 and a mounting portion 152 extending from the main body 151 toward the buffer sliding block 140, the mounting portion 152 is inserted into the needle sleeve 120 and is in interference fit with a second opening end 123 (open) of the needle sleeve 120, and the buffer sliding block 140 is abutted to an upper surface of the mounting portion 152.

Referring to fig. 1, 2 and 3, in one embodiment, the nut 240 extends toward the valve core seat 230 to be close to or abut against the valve core seat 230. It should be noted that when the nut 240 extends toward the valve cartridge seat 230 to abut the valve cartridge seat 230, the coaxiality between the nut 240, the valve stem 110, and the valve port 231 is better improved.

Further, a cooling medium passage 242 is provided on a peripheral side wall of one end of the nut 240 close to the valve port 231, so that the cooling medium flows from the cooling medium passage 242 to the valve port 231. Here, it should be noted that, by providing the refrigerant passage 242 on the nut 240, when the refrigerant flows through the refrigerant passage 242, the bubbles in the refrigerant can be broken, thereby preventing the bubbles in the refrigerant from generating a loud noise when flowing through the valve port 231. Therefore, the refrigerant passing opening 242 can also have a good noise reduction effect. The shape of the refrigerant passing opening 242 may be circular, oval, square, or other special shapes, and is not limited specifically.

The utility model discloses still provide a refrigeration plant, this refrigeration plant includes electronic expansion valve 200, and above-mentioned embodiment is referred to this electronic expansion valve 200's concrete structure, because this refrigeration plant has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, and the repeated description is no longer given here. The refrigeration equipment can be an air conditioner, a refrigerator, a heat pump water heater and the like.

The above is only the optional embodiment of the present invention, and not the scope of the present invention is limited thereby, all the equivalent structure changes made by the contents of the specification and the drawings are utilized under the inventive concept of the present invention, or the direct/indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A valve needle assembly for an electronic expansion valve, comprising:

a valve needle sleeve having opposing first and second open ends;

2. The valve needle assembly of claim 1 wherein a flange portion is provided on a peripheral wall of the drive end of the valve stem, the flange portion being located within the valve needle sleeve, the first open end of the valve needle sleeve being provided with a necked-down portion abutting the flange portion, and one end of the buffer spring being sleeved over the drive end of the valve stem and abutting the flange portion.

3. The valve needle assembly of claim 2, wherein a positioning pillar is disposed on a side of the cushion slider facing the valve stem, and the other end of the cushion spring is sleeved on the positioning pillar and abuts against the cushion slider.

4. The valve needle assembly of claim 2 wherein the cross-sectional diameter of the valve needle sleeve is greater than the cross-sectional diameter of the flange portion.

5. The valve needle assembly of claim 1 wherein the cushion slide has a projection projecting toward the valve needle, the cushion slide abutting the valve needle through the projection.

6. The valve pin assembly of claim 5 wherein the convex surface is a cambered surface.

7. The valve needle assembly of any one of claims 1 to 6, wherein the outer wall surface of the buffer sliding block is provided with a limiting convex part, and the limiting convex part is arranged along the circumferential direction of the buffer sliding block.

8. The valve needle assembly of claim 7, wherein the number of the limiting protrusions is at least two, and at least two limiting protrusions are distributed at intervals along the circumferential direction of the buffer sliding block;

9. A valve needle assembly as claimed in any one of claims 1 to 6 wherein the internal diameter of the valve needle sleeve is greater than the external diameter of the damping slide.

10. A valve needle assembly as claimed in any one of claims 1 to 6 wherein the second open end of the valve needle sleeve is open and the outer wall surface of the valve needle is an interference fit with the open end.

11. The valve needle assembly of any one of claims 1 to 6 wherein the buffer spring is a compression spring.

12. The needle assembly of any one of claims 1 to 6 wherein the damping slide is of plastics material.

13. An electronic expansion valve, comprising:

the nut is provided with a mounting hole; and

the valve needle assembly of any one of claims 1 to 12, wherein a valve stem of the valve needle assembly is arranged through the mounting hole and is in threaded connection with the nut.

14. The electronic expansion valve according to claim 13, further comprising a valve seat and a valve core seat, wherein the valve core seat is disposed on the valve seat and has a valve port, the valve needle is detachably mounted to the valve port, the nut is connected to the valve seat, and the nut extends toward the valve core seat to be close to or abutted against the valve core seat.

15. The electronic expansion valve according to claim 14, wherein a coolant passage is provided on a peripheral side wall of one end of the nut adjacent to the valve core seat.

16. Refrigeration device, comprising an electronic expansion valve according to any of claims 13 to 15.