Valve needle assembly, valve stem, electronic expansion valve and refrigeration equipment

Abstract

The present invention discloses a valve needle assembly, a valve stem, an electronic expansion valve and a refrigeration device. The valve needle assembly includes a valve needle, a valve needle sleeve and a valve stem. The valve needle sleeve has opposite first and second open ends, and the valve needle is installed at the second open end. The valve stem includes a threaded rod section for threadedly cooperating with a nut and a driving rod section connected to the threaded rod section. The driving rod section is movably cooperated with the valve needle sleeve through the first open end to drive the valve needle to actuate. A flange portion is provided on the peripheral wall of the driving rod section, and the flange portion is in limiting cooperation with the valve needle sleeve to prevent the driving rod section from disengaging from the first open end. The ratio of the outer diameter of the flange portion to the length of the threaded rod section is greater than or equal to 0.4 and less than or equal to 0.6. The valve needle assembly of the present invention can not only prevent the valve stem from jamming during movement, but also ensure that the valve stem moves smoothly along its axial direction, thereby improving the performance of the electronic expansion valve.

Description

Technical Field

[0001] The present invention relates to the technical field of control valves, and particularly to a valve needle assembly, a valve stem, an electronic expansion valve, and a refrigeration device. Background Art

[0002] In the related art, an electronic expansion valve includes a nut, a valve stem, a valve needle sleeve, and a valve needle. The threaded rod section of the valve stem is threadedly connected to the nut, and the driving rod section of the valve stem extends into the valve needle sleeve and is in clearance fit with the valve needle sleeve. The valve stem rotates and moves axially at the same time to drive the valve needle to block or open the valve port, realizing the opening or closing of the electronic expansion valve. Since the valve stem is prone to jamming during movement, the normal use of the electronic expansion valve is affected.

[0003] The above content is only used to assist in understanding the technical solution of the invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main object of the present invention is to propose a valve needle assembly, aiming to solve the technical problem that the valve stem is prone to jamming in the prior art.

[0005] To achieve the above object, the present invention proposes a valve needle assembly for an electronic expansion valve, and the valve needle assembly includes:

[0006] A valve needle;

[0007] A valve needle sleeve having opposite first and second open ends, and the valve needle is installed at the second open end; and

[0008] A valve stem including a threaded rod section for threadedly cooperating with a nut and a driving rod section connected to the threaded rod section. The driving rod section is movably cooperated with the valve needle sleeve through the first open end to drive the valve needle to act; a flange portion is provided on the peripheral wall of the driving rod section, and the flange portion is in limiting cooperation with the valve needle sleeve to limit the driving rod section from disengaging from the first open end;

[0009] Wherein, the ratio of the outer diameter of the flange portion to the length of the threaded rod section is greater than or equal to 0.4 and less than or equal to 0.6.

[0010] In one embodiment, a necking section for abutting against the flange portion is provided at the first open end, and the difference between the outer diameter of the flange portion and the inner diameter of the necking section is greater than or equal to 0.4 mm and less than or equal to 1.0 mm.

[0011] In one embodiment, the valve stem includes a necking rod section connecting the driving rod section and the threaded rod section, and the cross-sectional area of the driving rod section is larger than the cross-sectional area of the necking rod section.

[0012] In one embodiment, the necked rod section is tapered along the direction of the drive rod section towards the threaded rod section.

[0013] In one embodiment, the valve needle assembly includes a buffer assembly disposed within the valve needle sleeve, and the drive rod section is connected to the valve needle through the buffer assembly.

[0014] In one embodiment, the buffer assembly includes a buffer slider and a buffer spring. The buffer slider abuts against the valve needle, and the flange portion of the valve rod is connected to the buffer slider through the buffer spring.

[0015] In one embodiment, a positioning post is provided on one side of the buffer slider facing the valve rod, and one end of the buffer spring close to the buffer slider is sleeved on the positioning post and abuts against the buffer slider.

[0016] In one embodiment, the buffer slider has a protrusion protruding towards the valve needle, and the buffer slider abuts against the valve needle through the protrusion.

[0017] In one embodiment, the surface of the protrusion is an arc surface.

[0018] In one embodiment, a limiting convex portion is provided on the outer wall surface of the buffer slider, and the limiting convex portion is arranged along the circumferential direction of the buffer slider.

[0019] In one embodiment, there are at least two limiting convex portions, and at least two limiting convex portions are spaced apart along the circumferential direction of the buffer slider;

[0020] Alternatively, the limiting convex portion is an annular rib extending along the circumferential direction of the buffer slider.

[0021] In one embodiment, the second opening end of the valve needle sleeve is open, and the outer wall surface of the valve needle is in interference fit with the opening.

[0022] The present invention also provides a valve rod for an electronic expansion valve. The electronic expansion valve includes a nut and a valve needle assembly. The valve needle assembly includes a valve needle sleeve and a valve needle. The valve needle sleeve has opposite first and second opening ends. The valve needle is installed at the second opening end of the valve needle sleeve. The valve rod includes:

[0023] A threaded rod section for threaded engagement with the nut; and

[0024] A drive rod section connected to the threaded rod section. The drive rod section is used for movably cooperating with the valve needle sleeve through the first opening end to drive the valve needle to act; a flange portion is provided on the peripheral wall of the drive rod section, and the flange portion is in limiting cooperation with the valve needle sleeve to limit the drive rod section from disengaging from the first opening end;

[0025] Wherein, the ratio of the outer diameter of the flange portion to the length of the threaded rod segment is greater than or equal to 0.4 and less than or equal to 0.6.

[0026] The present invention also provides an electronic expansion valve, which includes a nut and a valve needle assembly. An installation hole is formed in the nut, and the installation hole includes a threaded hole segment; the valve needle assembly includes:

[0027] A valve needle;

[0028] A valve needle sleeve having opposite first and second open ends, and the valve needle is installed at the second open end; and

[0029] A valve stem including a threaded rod segment and a driving rod segment connected to the threaded rod segment. The threaded rod segment is threadedly connected to the threaded hole segment, and the driving rod segment is movably engaged with the valve needle sleeve through the first open end to drive the valve needle to act; a flange portion is provided on the peripheral wall of the driving rod segment, and the flange portion is in limit fit with the valve needle sleeve to limit the driving rod segment from disengaging from the first open end;

[0030] Wherein, the ratio of the outer diameter of the flange portion to the length of the threaded rod segment is greater than or equal to 0.4 and less than or equal to 0.6.

[0031] In one embodiment, the electronic expansion valve further includes a valve seat and a valve core seat. The valve core seat is arranged on the valve seat and is provided with a valve port. The valve needle is detachably installed at the valve port. The nut is connected to the valve seat, and the nut extends towards the valve core seat to be close to or abut against the valve core seat.

[0032] In one embodiment, a refrigerant passage port is provided on the peripheral side wall of one end of the nut close to the valve core seat.

[0033] The present invention also provides a refrigeration device, which includes an electronic expansion valve. The electronic expansion valve includes a nut and a valve needle assembly. An installation hole is formed in the nut, and the installation hole includes a threaded hole segment; the valve needle assembly includes:

[0034] A valve needle;

[0035] A valve needle sleeve having opposite first and second open ends, and the valve needle is installed at the second open end; and

[0036] A valve stem including a threaded rod segment and a driving rod segment connected to the threaded rod segment. The threaded rod segment is threadedly connected to the threaded hole segment, and the driving rod segment is movably engaged with the valve needle sleeve through the first open end to drive the valve needle to act; a flange portion is provided on the peripheral wall of the driving rod segment, and the flange portion is in limit fit with the valve needle sleeve to limit the driving rod segment from disengaging from the first open end;

[0037] Wherein, the ratio of the outer diameter of the flange portion to the length of the threaded rod section is greater than or equal to 0.4 and less than or equal to 0.6.

[0038] The valve needle assembly of the present invention includes a valve needle, a valve needle sleeve, and a valve stem. The valve needle sleeve has opposite first and second open ends, and the valve needle is installed at the second open end. The valve stem includes a threaded rod section for threaded cooperation with a nut and a driving rod section connected to the threaded rod section. The driving rod section is movably engaged with the valve needle sleeve through the first open end to drive the valve needle to act. A flange portion is provided on the peripheral wall of the driving rod section, and the flange portion is in limiting cooperation with the valve needle sleeve to prevent the driving rod section from disengaging from the first open end. The ratio of the outer diameter of the flange portion to the length of the threaded rod section is greater than or equal to 0.4 and less than or equal to 0.6. Thus, on the one hand, the outer diameter of the flange portion is not too small, thereby avoiding the flange portion being stuck at the first open end of the valve needle sleeve or the flange portion disengaging from the first open end of the valve needle sleeve. On the other hand, the outer diameter of the flange portion is not too large, avoiding excessive friction between the flange portion and the inner wall surface of the valve needle sleeve, which causes the valve stem to be difficult to move axially. Therefore, the valve needle assembly of the present invention can not only avoid the valve stem being stuck during movement but also ensure that the valve stem moves smoothly along its axis, thereby improving the service performance of the electronic expansion valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0040] Figure 1 It is a schematic internal structure diagram of an embodiment of the electronic expansion valve of the present invention;

[0041] Figure 2 For Figure 1 a partial structure diagram of the electronic expansion valve in

[0042] Figure 3 For Figure 2 a schematic structural diagram of an embodiment of the valve core assembly in

[0043] Figure 4 For Figure 3 a partial enlarged view at A in

[0044] Figure 5 For Figure 3 a schematic structural diagram of the valve stem in

[0045] Figure 6 is Figure 3 a schematic structural diagram of the middle valve needle sleeve.

[0046] Explanation of the reference numerals in the attached drawings:

[0047] Label Name Label Name Label Name 200 Electronic expansion valve 250 Magnetic rotor 122 Necking part 210 Outer cover 100 Valve needle assembly 123 Second open end 220 Valve seat 110 Valve stem 130 Buffer spring 230 Valve core seat 111 Drive rod section 140 Buffer slider 231 Valve port 112 Flange part 141 Positioning post 240 Nut 113 Threaded rod section 142 Protrusion 241 Mounting hole 114 Guide rod section 143 Limit convex part 242 Threaded hole section 115 Necking rod section 150 Valve needle 243 Guide hole section 120 Valve needle sleeve 151 Main body part 244 Refrigerant passage 121 First open end 152 Mounting part

[0048] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0049] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, such descriptions of "first", "second", etc. are only for descriptive purposes and should not be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that satisfies both A and B simultaneously.

[0050] The present invention provides an electronic expansion valve.

[0051] Please refer to Figure 1 , Figure 2 and Figure 3 , the present invention provides a valve needle assembly 100. The electronic expansion valve 200 includes a valve body, and the valve body includes an outer cover 210, a valve seat 220 fixedly connected to the outer cover 210, a magnetic rotor 250 rotatable within the outer cover 210, a nut 240, and a valve needle assembly 100. The outer cover 210 and the valve seat 220 enclose a valve cavity. The magnetic rotor 250, the nut 240, and the valve needle assembly 100 are all disposed within the valve cavity. The nut 240 is connected to the valve seat 220, and the magnetic rotor 250 drives the valve needle assembly 100 to move to control the flow rate of the electronic expansion valve 200.

[0052] Next, the structure of the valve needle assembly 100 will be introduced.

[0053] Please refer to Figure 1 , Figure 2 , Figure 3, the present invention provides a valve needle assembly 100 for an electronic expansion valve 200. The valve needle assembly 100 includes a valve needle sleeve 120, a valve stem 110, and a valve needle 150. The valve needle sleeve 120 has opposite first and second open ends 121 and 123; the valve needle 150 is installed at the second open end 123. The valve stem 110 includes a threaded rod section 113 and a drive rod section 111 connected to the threaded rod section 113. The threaded rod section 113 is used to cooperate with a threaded hole section 242 of a nut 240. The drive rod section 111 is disposed through the first open end 121, and the drive rod section 111 is movably engaged with the valve needle sleeve 120 through the first open end 121 to drive the valve needle 150 to actuate; a flange portion 112 is provided on the circumferential wall of the drive rod section 111, and the flange portion 112 is in limit cooperation with the valve needle sleeve 120 to prevent the drive rod section 111 from disengaging from the first open end 121. Wherein, the ratio of the outer diameter D1 of the flange portion 112 to the length L1 of the threaded rod section 113 is greater than or equal to 0.4 and less than or equal to 0.6.

[0054] Specifically, the nut 240 is provided with an installation hole 241 extending along its axial direction. The installation hole 241 includes a threaded hole section 242. The valve stem 110 is installed in the installation hole 241, and the threaded rod section 113 of the valve stem 110 is threadedly connected to the threaded hole section 242 of the installation hole 241. The valve stem 110 further includes a guide rod section 114, and the threaded rod section 113 connects the guide rod section 114 and the drive rod section 111. The installation hole 241 includes a guide hole section 243 that cooperates with the guide rod section 114, and an interference fit or a clearance fit exists between the guide rod section 114 and the guide hole section 243. The provision of the guide rod section 114 can also reduce the shaking of the valve stem 110 during movement, thereby improving the service performance of the electronic expansion valve 200.

[0055] The driving rod segment 111 is in clearance fit with the first opening end 121 of the valve needle sleeve 120, so that the driving rod segment 111 can move axially relative to the valve needle sleeve 120. The flange portion 112 is provided on the peripheral wall of the driving rod segment 111, specifically arranged in a ring shape. The flange portion 112 and the driving rod segment 111 are integrally formed. Of course, the flange portion 112 can also be separately provided from the driving rod segment 111, without specific limitation. In the embodiment of the present invention, in order to enable the valve needle 150 assembly to have better performance, the ratio of the outer diameter D1 of the flange portion 112 to the length L1 of the threaded rod segment 113 can be greater than or equal to 0.4 and less than or equal to 0.6. This is because if the ratio of the outer diameter D1 of the flange portion 112 to the length L1 of the threaded rod segment 113 is less than 0.4, the flange portion 112 may be stuck at the first opening end 121 of the valve needle sleeve 120 or the flange portion 112 may come out of the first opening end 121 of the valve needle sleeve 120; if the ratio of the outer diameter D1 of the flange portion 112 to the length L1 of the threaded rod segment 113 is greater than 0.6, the flange portion 112 may abut against the inner wall surface of the valve needle 150, resulting in excessive friction between the flange portion 112 and the inner wall surface of the valve needle sleeve 120 and making it difficult for the valve rod 110 to move axially.

[0056] It should be noted that the length L1 of the threaded rod segment 113 refers to the length of the threaded rod segment 113 along the axial direction of the valve rod 110. The ratio of the outer diameter D1 of the flange portion 112 to the length L1 of the threaded rod segment 113 being greater than or equal to 0.4 and less than or equal to 0.6 can ensure that the length L1 of the threaded rod segment 113 is appropriate, thereby reducing the sway of the valve rod 110 during movement and avoiding jamming of the valve rod 110 during movement. Optionally, in an embodiment, in order to further improve the movement stability of the valve rod 110 and reduce the sway of the valve rod 110, the threaded rod segment 113 can include a plurality of sub-threaded rod segments arranged at intervals along the axial direction of the valve rod 110, and the pitch between the respective sub-threaded rod segments is different. In this way, while ensuring that the valve rod 110 will not jam, the friction between the threaded rod segment 113 and the threaded hole segment 242 of the nut 240 is increased as much as possible, thereby reducing the sway of the valve rod 110.

[0057] The valve needle 150 assembly of the present invention includes a valve needle sleeve 120, a valve stem 110, and a valve needle 150. The valve needle sleeve 120 has opposite first and second open ends 121 and 123. The valve stem 110 includes a threaded rod section 113 and a driving rod section 111 connected to the threaded rod section 113. The threaded rod section 113 is used to cooperate with a threaded hole section 242 of a nut 240. The driving rod section 111 is disposed through the first open end 121. The driving rod section 111 is movably engaged with the valve needle sleeve 120 through the first open end 121 to drive the valve needle 150 to actuate. A flange portion 112 is provided on the peripheral wall of the driving rod section 111. The flange portion 112 is in limiting cooperation with the valve needle sleeve 120 to prevent the driving rod section 111 from disengaging from the first open end 121. Wherein, the ratio of the outer diameter D1 of the flange portion 112 to the length L1 of the threaded rod section 113 is greater than or equal to 0.4 and less than or equal to 0.6. Thus, on the one hand, the outer diameter D1 of the flange portion 112 is not too small, thereby avoiding the flange portion 112 being stuck at the first open end 121 of the valve needle sleeve 120 or the flange portion 112 disengaging from the first open end 121 of the valve needle sleeve 120. On the other hand, the outer diameter D1 of the flange portion 112 is not too large, avoiding excessive friction between the flange portion 112 and the inner wall surface of the valve needle sleeve 120, which causes the valve stem 110 to be difficult to move axially. Therefore, the valve needle 150 assembly of the present invention can not only avoid the valve stem 110 from being stuck, but also ensure the smooth movement of the valve stem 110, thereby improving the service performance of the electronic expansion valve 200.

[0058] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , in an embodiment, a reduced neck portion 122 abutting against the flange portion 112 is provided at the first open end 121. The shape of the reduced neck portion 122 is adapted to the shape of the driving rod section 111. 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 refrigerant pressure), the valve needle 150 and the valve port 231 always maintain a sealed contact. There is a gap between the flange portion 112 and the reduced neck portion 122 of the valve needle sleeve 120. The valve stem 110 drives the buffer assembly to rotate together, while the valve needle 150 remains stationary. When the valve needle 150 continues to open to the second position (i.e., the position of the valve opening pulse point), the valve needle 150 and the valve port 231 initially continue to maintain a sealed contact. After the valve stem 110 moves axially until the flange portion 112 abuts against the reduced neck portion 122 of the valve needle sleeve 120 (i.e., the gap between the flange portion 112 and the reduced neck portion 122 of the valve needle sleeve 120 is zero), the valve needle 150 will follow the valve stem 110 to move together.

[0059] By the cooperation of the necking part 122 and the flange part 112, it can effectively prevent the flange part 112 from disengaging from the first opening end 121 of the valve needle sleeve 120. Optionally, the difference between the outer diameter D1 of the flange part 112 and the inner diameter D2 of the necking part 122 is greater than or equal to 0.4 mm and less than or equal to 1.0 mm. In this way, while ensuring that the flange part 112 will not disengage from the first opening end 121 of the valve needle sleeve 120, it can also ensure that there is a gap between the flange part 112 and the inner wall surface of the valve needle sleeve 120, so that the valve stem 110 can move smoothly along its axis relative to the valve needle sleeve 120. Further, the difference between the outer diameter D1 of the flange part 112 and the inner diameter D2 of the necking part 122 is greater than or equal to 0.6 mm and less than or equal to 0.8 mm.

[0060] Please refer to Figure 3 、 Figure 4 and Figure 5 In an embodiment, the valve stem 110 includes a necked rod section 115. The necked rod section 115 is located between the driving rod section 111 and the threaded rod section 113 and connects the driving rod section 111 and the threaded rod section 113. The cross-sectional area of the driving rod section 111 is larger than the cross-sectional area of the necked rod section 115. In this way, it can avoid the valve needle 150 assembly from being stuck due to coaxiality problems. Specifically, during the axial movement of the valve stem 110, the threaded rod section 113 cooperates with the threaded hole section 242 of the nut 240. If there is a coaxiality problem inside the valve needle 150 assembly, there will be an eccentricity problem between the driving rod section 111 and the valve needle sleeve 120. The cross-sectional area of the necked rod section 115 is smaller than the cross-sectional area of the driving rod section 111 and at the same time smaller than the cross-sectional area of the threaded rod section 113. After the necked rod section 115 extends into the first opening end 121 of the valve needle sleeve 120, it will not be stuck inside the valve needle sleeve 120 and cannot be removed.

[0061] Further, please refer to Figure 5 The necked rod section 115 is tapered along the direction from the driving rod section 111 towards the threaded rod section 113. In this way, the necked rod section 115 can play a good guiding role, so that the necked rod section 115 can be smoothly removed after extending into the valve needle sleeve 120.

[0062] Please refer to Figure 1 、 Figure 2 and Figure 3, in one embodiment, the valve needle 150 is installed at the second opening end 123 of the valve needle sleeve 120. The valve needle 150 and the second abutting end of the valve needle sleeve 120 are in interference fit. The driving rod section 111 of the valve rod 110 is connected to the valve needle 150 through a buffer assembly. A valve core seat 230 is provided on the valve seat 220, and a valve port 231 corresponding to the valve needle 150 is provided on the valve core seat 230. The valve needle 150 is detachably installed in the valve port 231. In this way, by driving the magnetic rotor 250 to rotate through the coil, the rotational motion of the magnetic rotor 250 can be converted into the axial motion of the valve rod 110. The valve rod 110 drives the valve needle 150 connected thereto to rise or fall, thereby controlling the flow rate of the electronic expansion valve 200. Here, the driving rod section 111 of the valve rod 110 is connected to the valve needle 150 through a buffer assembly, which can avoid the direct connection between the valve rod 110 and the valve needle 150, and prevent the valve needle 150 from rotating relative to the valve port 231 and causing wear. There are various structures for the buffer assembly, and the structure of the buffer assembly will be introduced in detail below.

[0063] Please refer to Figure 3 and Figure 4 , in one embodiment, the buffer assembly includes a buffer slider 140 and a buffer spring 130. The buffer slider 140 abuts against the valve needle 150, and one end of the buffer spring 130 is connected to the driving rod section 111, and the other end is connected to the buffer slider 140. Specifically, the buffer spring 130 is a compression spring. One end of the buffer spring 130 is sleeved on the driving rod section 111 and abuts against the flange portion 112, and the other end abuts against the buffer slider 140.

[0064] In this embodiment, the buffer slider 140 can be made of a material with high lubricity, which can reduce the friction force between the buffer slider 140 and the valve needle 150, thereby reducing the wear caused by the relative rotation of the buffer slider 140 with respect to the valve needle 150. Optionally, the buffer slider 140 is made of a non-metallic material. For example, but not limited to, the buffer slider 140 is made of a plastic material. By using a non-metallic buffer slider 140, the friction force between the buffer slider 140 and the valve needle 150 made of a metal material can be reduced, and further the wear caused by the relative rotation of the buffer slider 140 with respect to the valve needle 150 can be reduced.

[0065] It can be understood that in another embodiment, the buffer assembly only includes the buffer spring 130. One end of the buffer spring 130 is connected to the driving rod section 111, and the other end is connected to the valve needle 150. Specifically, the buffer spring 130 is a compression spring. One end of the buffer spring 130 is sleeved on the driving rod section 111 and abuts against the flange portion 112, and the other end abuts against the valve needle 150.

[0066] Please refer to Figure 3 and Figure 4 Further, a positioning post 141 is provided on one side of the buffer slider 140 facing the valve stem 110. The positioning post 141 is opposite to and spaced from the driving end of the valve stem 110. The other end of the buffer spring 130 is sleeved on the positioning post 141 and abuts against the buffer slider 140. In this way, through the arrangement of the positioning post 141, on the one hand, it can play a role in fixing and installing the buffer spring 130, and on the other hand, it can also play a role in positioning the buffer spring 130 to ensure that the buffer spring 130 always moves along the axial direction of the valve stem 110 without deviation.

[0067] Please refer to Figure 3 and Figure 4 In one embodiment, in order to further reduce the contact area between the buffer slider 140 and the valve needle 150, thereby reducing the wear caused when the buffer slider 140 rotates relative to the valve needle 150, a protrusion 142 protruding towards the valve needle 150 is provided on the buffer slider 140. The buffer slider 140 abuts against the valve needle 150 through the protrusion 142. Optionally, the surface of the protrusion 142 is an arc surface. By providing the arc-shaped protrusion 142, on the one hand, it can reduce the contact area between the buffer slider 140 and the valve needle 150, and on the other hand, the arc-shaped protrusion 142 can play a good fulcrum role, enabling the buffer slider 140 to rotate around this fulcrum without position deviation, ensuring that the valve stem 110, the valve needle sleeve 120, the buffer spring 130 and the buffer slider 140 always maintain a high coaxiality.

[0068] Please refer to Figure 3 and Figure 4 In one embodiment, the inner diameter of the valve needle sleeve 120 is larger than the outer diameter D1 of the buffer slider 140. This can reduce the frictional force between the buffer slider 140 and the inner wall surface of the valve needle sleeve 120, enabling the buffer slider 140 to rotate smoothly relative to the valve needle sleeve 120.

[0069] In order to prevent the buffer slider 140 from shifting in position during rotation, a limiting protrusion 143 can be provided on the outer wall surface of the buffer slider 140. The limiting protrusion 143 is arranged along the circumferential direction of the buffer slider 140. In this way, by providing the limiting protrusion 143 to limit the buffer slider 140, it is possible to prevent the buffer slider 140 from shifting in position during rotation.

[0070] In this embodiment, the limiting convex portion 143 and the buffer slider 140 are integrally formed; it can be understood that in other embodiments, the limiting convex portion 143 and the buffer slider 140 can be separately provided, and no special limitation is made here. There can be various structures for the limiting convex portion 143. For example, in one embodiment, there are at least two limiting convex portions 143, and the at least two limiting convex portions 143 are circumferentially spaced apart along the buffer slider 140. By providing a plurality of limiting convex portions 143, the buffer slider 140 can be effectively prevented from shifting. For another example, in another embodiment, there is one limiting convex portion 143, and the limiting convex portion 143 is an annular rib extending along the circumference of the buffer slider 140.

[0071] Considering that it is inevitable for small foreign objects to enter the system during the use of the electronic expansion valve 200, if the foreign object gets stuck between the valve port 231 and the valve needle 150, the valve needle 150 will deflect and cause the valve needle 150 to be stuck. To avoid the valve needle 150 from being stuck, the valve needle 150 and the valve port 231 can be in clearance fit, the valve stem 110 and the valve needle sleeve 120 can be in clearance fit, and the valve needle sleeve 120 and the inner wall surface of the nut 240 can be in clearance fit.

[0072] In one embodiment, the clearance between the outer wall surface of the valve needle sleeve 120 and the inner wall surface of the nut 240 is greater than the minimum fit clearance between the valve needle 150 and the inner wall surface of the valve port 231; the fit clearance between the valve stem 110 and the valve needle sleeve 120 is greater than the minimum fit clearance between the valve needle 150 and the inner wall surface of the valve port 231.

[0073] Specifically, the minimum fit clearance between the valve needle 150 and the inner wall surface of the valve port 231 refers to the minimum clearance between the outer wall surface of the needle-shaped portion of the valve needle 150 and the inner wall surface of the valve port 231 when the valve needle 150 is inserted into the valve port 231. The fit clearance between the valve stem 110 and the valve needle sleeve 120 refers to the clearance between the wall surface of the valve needle sleeve 120 that guides the driving rod section 111 of the valve stem 110 and the outer wall surface of the guiding rod section 111.

[0074] When there is a foreign object stuck between the valve port 231 and the valve needle 150, even if the valve needle 150 is deflected, since the fitting clearance between the valve stem 110 and the valve needle sleeve 120 is greater than the minimum fitting clearance between the valve needle 150 and the inner wall surface of the valve port 231, there is sufficient movement space between the valve needle sleeve 120 and the valve stem 110. The valve needle 150 can drive the entire valve needle sleeve 120 to tilt relative to the valve stem 110 toward the inner wall surface of the nut 240, without causing the valve needle sleeve 120 to be stuck with the valve stem 110 and affecting the up and down movement of the valve needle 150. And when the valve needle 150 drives the entire valve needle sleeve 120 to tilt relative to the valve stem 110 toward the inner wall surface of the nut 240, since there is sufficient movement space between the valve needle sleeve 120 and the inner wall surface of the nut 240, the valve needle sleeve 120 will not be stuck with the nut 240. Furthermore, when a foreign object is stuck between the valve needle 150 and the valve port 231, since there is sufficient deviation movement space on both the valve stem 110 side and the nut 240 side when the valve needle 150 and the entire valve needle sleeve 120 are deflected, the valve needle 150 can still move smoothly in the up and down direction, thus effectively avoiding the valve needle 150 from being stuck. At the same time, it can also avoid the influence of eccentricity caused by the coaxiality deviation during the assembly process of the valve needle assembly 100 on the valve needle 150.

[0075] Please refer to Figure 3 and Figure 4 , in an embodiment, the first open end 121 of the valve needle sleeve 120 is a through hole penetrating the upper end of the valve needle sleeve 120, and the driving end of the valve stem 110 is in clearance fit with the through hole; the second open end 123 of the valve needle sleeve 120 is an open end, and the outer wall surface of the valve needle 150 is in interference fit with the open end. Of course, it can be understood that in other embodiments, the second open end 123 of the valve needle sleeve 120 can also be a through hole penetrating the lower end of the valve needle sleeve 120, and no specific limitation is made here.

[0076] To improve the connection sealing performance and reliability between the valve needle 150 and the valve needle sleeve 120, the valve needle 150 and the second open end 123 of the valve needle sleeve 120 are welded. Specifically, the valve needle 150 includes a main body portion 151 and an installation portion 152 extending from the main body portion 151 toward the buffer slider 140. The installation portion 152 is inserted into the valve needle sleeve 120 and is in interference fit with the second open end 123 (open end) of the valve needle sleeve 120, and the buffer slider 140 abuts against the upper surface of the installation portion 152.

[0077] In addition, please refer to Figure 1 , Figure 2 and Figure 3, in one embodiment, the nut 240 extends towards the valve core seat 230 to be close to or in contact with the valve core seat 230. It should be noted that when the nut 240 extends towards the valve core seat 230 to be in contact with the valve core seat 230, the coaxiality among the nut 240, the valve stem 110 and the valve port 231 can be better improved.

[0078] Further, a refrigerant passage port 244 is provided on the circumferential side wall of one end of the nut 240 close to the valve port 231, so that refrigerant can flow from the refrigerant passage port 244 to the valve port 231. Here, it should be noted that by providing the refrigerant passage port 244 on the nut 240, when the refrigerant flows through the refrigerant passage port 244, the bubbles in the refrigerant can be broken, thereby avoiding generating greater noise when the bubbles in the refrigerant flow through the valve port 231. Therefore, the setting of the refrigerant passage port 244 can also play a good role in noise reduction. Among them, the shape of the refrigerant passage port 244 can be circular, oval, square or other special-shaped shapes, etc., without specific limitation.

[0079] The present invention also proposes a refrigeration device, which includes an electronic expansion valve 200. The specific structure of the electronic expansion valve 200 refers to the above embodiments. Since this refrigeration device adopts all the technical solutions of the above all embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated one by one here. Among them, the refrigeration device can be an air conditioner, a refrigerator, a freezer, a heat pump water heater, etc.

[0080] The above are only optional embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any 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, the electronic expansion valve comprising a nut, a valve seat connected to the nut, and a valve core seat provided on the valve seat, the valve core seat being provided with a valve port, characterized in that, Comprising: A valve needle, which is detachably mounted on the valve port; A valve needle sleeve having opposite first and second open ends, and the valve needle is mounted on the second open end; and A valve stem including a threaded rod section for threaded cooperation with a nut and a drive rod section connected to the threaded rod section. The drive rod section is movably cooperated with the valve needle sleeve through the first open end to drive the valve needle to act; a flange portion is provided on the peripheral wall of the drive rod section, and the flange portion is in limit cooperation with the valve needle sleeve to limit the drive rod section from disengaging from the first open end; Wherein, the ratio of the outer diameter of the flange portion to the length of the threaded rod section is greater than or equal to 0.4 and less than or equal to 0.6; the gap between the outer wall surface of the valve needle sleeve and the inner wall surface of the nut is greater than the minimum fit gap between the valve needle and the inner wall surface of the valve port; the fit gap between the valve stem and the valve needle sleeve is greater than the minimum fit gap between the valve needle and the inner wall surface of the valve port.

2. The valve needle assembly according to claim 1, wherein, The first open end is provided with a necking portion that abuts against the flange portion, and the difference between the outer diameter of the flange portion and the inner diameter of the necking portion is greater than or equal to 0.4 mm and less than or equal to 1.0 mm.

3. The valve needle assembly according to claim 1, wherein, The valve stem includes a necked-down rod section that connects the drive rod section and the threaded rod section, and the cross-sectional area of the drive rod section is larger than the cross-sectional area of the necked-down rod section.

4. The valve needle assembly according to claim 3, wherein, The necked-down rod section is tapered in the direction from the drive rod section towards the threaded rod section.

5. The valve needle assembly according to claim 1, wherein, The valve needle assembly includes a buffer assembly provided in the valve needle sleeve, and the drive rod section is connected to the valve needle through the buffer assembly.

6. The valve needle assembly according to claim 5, wherein, The buffer assembly includes a buffer slider and a buffer spring. The buffer slider abuts against the valve needle, and the flange portion of the valve stem is connected to the buffer slider through the buffer spring.

7. The valve needle assembly according to claim 6, characterized in that, A positioning post is provided on one side of the buffer slider facing the valve stem, and one end of the buffer spring close to the buffer slider is sleeved on the positioning post and abuts against the buffer slider.

8. The valve needle assembly according to claim 6, wherein, The buffer slider has a protrusion protruding towards the valve needle, and the buffer slider abuts against the valve needle through the protrusion.

9. The valve needle assembly according to claim 8, characterized in that, The surface of the protrusion is an arc surface.

10. The valve needle assembly according to claim 6, characterized in that, Limiting protrusions are provided on the outer wall surface of the buffer slider, and the limiting protrusions are arranged along the circumferential direction of the buffer slider.

11. The valve needle assembly according to claim 10, wherein, There are at least two of the limiting protrusions, and at least two of the limiting protrusions are spaced apart along the circumferential direction of the buffer slider; Alternatively, the limiting protrusion is an annular rib extending along the circumferential direction of the buffer slider.

12. The valve needle assembly according to any one of claims 1 to 6, characterized in that, The second open end of the valve needle sleeve is an open end, and the outer wall surface of the valve needle is in interference fit with the open end.

13. A valve stem for an electronic expansion valve, characterized in that, An electronic expansion valve includes a nut and a valve needle assembly. The valve needle assembly is the valve needle assembly according to any one of claims 1 to 12. The valve needle assembly includes a valve needle sleeve and a valve needle. The valve needle sleeve has opposite first and second open ends, and the valve needle is mounted on the second open end of the valve needle sleeve. The valve stem includes: A threaded rod section for threaded cooperation with the nut; and A drive rod section, connected to the threaded rod section, the drive rod section being used to movably cooperate with the valve needle sleeve through the first open end to drive the valve needle to act; a flange portion is provided on the peripheral wall of the drive rod section, and the flange portion is in limit cooperation with the valve needle sleeve to limit the drive rod section from disengaging from the first open end; Wherein, the ratio of the outer diameter of the flange portion to the length of the threaded rod section is greater than or equal to 0.4 and less than or equal to 0.

6.

14. An electronic expansion valve, characterized in that, Comprising: A nut, an installation hole is formed in the nut, and the installation hole includes a threaded hole section; and The valve needle assembly according to any one of claims 1 to 12, the valve rod of the valve needle assembly is inserted through the installation hole, and the threaded rod section is threadedly connected to the threaded hole section.

15. The electronic expansion valve according to claim 14, characterized in that, The electronic expansion valve further includes a valve seat and a valve core seat, the valve core seat is arranged on the valve seat and is provided with a valve port, the valve needle is detachably installed in the valve port, the nut is connected to the valve seat, and the nut extends towards the valve core seat to be close to or abut against the valve core seat.

16. The electronic expansion valve according to claim 15, wherein, A refrigerant passage port is provided on the peripheral side wall of one end of the nut close to the valve core seat.

17. A refrigeration device, characterized in that, Comprising the electronic expansion valve according to any one of claims 14 to 16.

Images