Electronic expansion valve and refrigeration equipment

Abstract

The utility model discloses an electronic expansion valve and refrigeration equipment, and relates to the technical field of electronic expansion valve.The electronic expansion valve comprises a valve needle and a valve seat, the valve seat is provided with a sealing end face facing the valve needle, and the middle of the valve seat is communicated to form a throttling channel; the throttling channel is provided with a throttling valve opening in the sealing end face, the sealing end face is provided with an annular groove surrounding the throttling channel, and the annular groove and the throttling channel are separated by an annular section part. A throttle valve port is defined by the ring section part, and the valve needle can axially and movably abut against or break away from the ring section part so as to close or open the throttle valve port; wherein the maximum wall thickness of the annular section part is smaller than the minimum width of the annular groove. According to the technical scheme, the electronic expansion valve aims to solve the problem that in the hard contact sealing mode of the valve needle and the valve port in the closed state, the leakage amount of the electronic expansion valve is large.

Description

Technical Field

[0001] This utility model relates to the field of electronic expansion valve technology, and in particular to an electronic expansion valve and a refrigeration device. Background Technology

[0002] In the core control field of refrigeration systems, the electronic expansion valve, as a key actuator for refrigerant flow regulation, directly affects the system's energy efficiency ratio through its sealing performance. Current electronic expansion valves generally employ a sealing structure with rigid contact between a metal valve needle and a metal valve port. While this achieves basic opening adjustment, it is limited by the inherent characteristics of the metal material and micron-level processing errors. In the closed state, a microscopic gap (e.g., 2-5 μm) always exists between the valve needle cone surface and the valve port end face. This results in the valve needle and valve port not being completely sealed in the closed state, leading to a certain leakage, typically above 30 ml / min. This results in energy loss in the refrigeration system. Utility Model Content

[0003] The main purpose of this invention is to propose an electronic expansion valve and a refrigeration device, which aims to solve the problem of large leakage in electronic expansion valves with hard contact sealing between valve needle and valve port in the closed state.

[0004] To achieve the above objectives, the electronic expansion valve proposed in this utility model includes:

[0005] valve needle; and

[0006] A valve seat has a sealing end face facing the valve needle, and a throttling channel is formed through the middle of the throttling channel; a throttling valve port is formed on the sealing end face, and an annular groove is provided around the throttling channel on the sealing end face, and the annular groove and the throttling channel are separated by an annular segment; the annular segment defines the throttling valve port, and the valve needle can move axially to abut or disengage from the annular segment to close or open the throttling valve port; wherein, the maximum wall thickness of the annular segment is less than the minimum width of the annular groove.

[0007] In one embodiment, the minimum inner diameter of the throttle valve orifice is D0, the maximum outer diameter of the annular segment is D1, and 0.4≤(D1-D0) / D0≤0.8.

[0008] In one embodiment, 0.45 ≤ (D1-D0) / D0 ≤ 0.55.

[0009] In one embodiment, the minimum inner diameter of the throttle valve orifice is D0, and the height of the annular segment is H, where 0.2 ≤ H / D0 ≤ 0.5.

[0010] In one embodiment, the maximum outer diameter of the annular segment is D1, the maximum inner diameter of the annular groove is D2, and the height of the annular segment is H, satisfying 0.3≤H / (D2-D1)≤0.7.

[0011] In one embodiment, 0.35 ≤ H / (D2-D1) ≤ 0.5.

[0012] In one embodiment, 0.3 ≤ H / (D2-D1) ≤ 0.4.

[0013] In one embodiment, the valve needle includes a needle shank portion and a valve needle portion with an outer diameter smaller than that of the needle shank portion, the valve needle portion having a first tapered portion;

[0014] The annular section has a sealing cone section and a straight section section. When the valve needle section 12 contacts the annular section section, the first cone section contacts and seals with the sealing cone section.

[0015] The height of the sealing cone is H1, which satisfies 0.1≤H1 / H≤0.9.

[0016] In one embodiment, 0.4 ≤ H1 / H ≤ 0.6.

[0017] In one embodiment, the valve needle package further includes a second cone portion, the angle between the second cone portion and the valve needle axis being smaller than that of the first cone portion, and the gap between the straight section portion and the second cone portion being gradually widened.

[0018] This utility model also proposes a refrigeration device, including an electronic expansion valve as described in any of the preceding claims.

[0019] The technical solution of this utility model is to set an annular groove around the throttling valve port in the valve seat. The annular groove makes the valve seat form an annular segment. The maximum wall thickness of the annular segment is less than the minimum width of the annular groove, so that the annular segment has a certain degree of flexibility. The medium in the valve seat under high pressure will generate radial extrusion force on the outer side of the annular segment, so that the outer peripheral wall of the valve needle and the annular segment can better abut against each other, thereby improving the sealing effect between the valve needle and the annular segment. When there is a coaxiality deviation in the assembly of the valve needle and the annular segment, it can adaptively improve the non-uniformity of the contact force between the valve needle and the valve port along the circumference, thereby effectively reducing the leakage problem caused by poor sealing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 A cross-sectional structural schematic diagram of an embodiment of the valve needle and valve seat provided by this utility model;

[0022] Figure 2 A schematic diagram of the structure of an embodiment of the valve seat provided by this utility model;

[0023] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure in the middle;

[0024] Figure 4 A bar chart showing the average leakage with and without annular grooves on the valve seat.

[0025] Explanation of icon numbers:

[0026] 10. Valve needle; 11. Needle bar; 12. Valve needle section; 12a. First cone section; 12b. Second cone section;

[0027] 20. Valve seat; 21. Sealing end face; 22. Throttling channel; 22a. Throttling valve port; 23. Annular groove; 24. Annular section; 24a. Sealing cone section; 24b. Straight section.

[0028] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0030] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0032] In the core control field of refrigeration systems, the electronic expansion valve, as a key actuator for refrigerant flow regulation, directly affects the system's energy efficiency ratio through its sealing performance. Current electronic expansion valves generally employ a sealing structure with rigid contact between a metal valve needle and a metal valve port. While this achieves basic opening adjustment, it is limited by the intrinsic properties of the metal material and micron-level processing errors. In the closed state, a microscopic gap (e.g., 2-5 μm) always exists between the valve needle cone surface and the valve port end face. In the closed state, the contact surface between the valve needle and the valve port cannot be completely sealed, resulting in a certain leakage, typically above 30 ml / min. This leads to energy loss in the refrigeration system.

[0033] It is worth noting that in multi-split air conditioning systems and other distributed refrigeration units, the dozens of electronic expansion valves configured in the system often operate asynchronously. When some indoor units are in standby mode, although their corresponding electronic expansion valves are theoretically in the closed position, continuous leakage caused by microscopic mismatch of the metal contact surfaces will lead to an abnormal increase in the system's refrigerant circulation. If 6 out of 10 parallel electronic expansion valves are in the closed state, the additional power consumption of the compressor caused by the cumulative leakage can reach more than 12% of the rated power.

[0034] Current industry improvements often focus on surface treatments (such as coating-like processes) or geometric optimization (conical seals). However, due to the inherent properties of metallic materials, conventional structural optimizations are approaching the theoretical sealing limit (leakage ≥22ml / min). This necessitates a breakthrough in the physical limitations of traditional hard metal seals, requiring innovative sealing structures to further improve the sealing performance of electronic expansion valves in the closed state and reduce leakage rates.

[0035] This invention proposes an electronic expansion valve, which aims to solve the problem of large leakage in the electronic expansion valve when it is closed.

[0036] Please see Figures 1 to 3In one embodiment of the present invention, the electronic expansion valve includes a valve needle 10 and a valve seat 20. The valve seat 20 has a sealing end face 21 facing the valve needle 10 and a throttling channel 22 formed through the middle. The throttling channel 22 has a throttling valve port 22a formed on the sealing end face 21. The sealing end face 21 is provided with an annular groove 23 around the throttling channel 22. The annular groove 23 and the throttling channel 22 are separated by an annular segment 24. The annular segment 24 defines the throttling valve port 22a. The valve needle 10 can move axially to abut or disengage from the annular segment 24 to close or open the throttling valve port 22a. The maximum wall thickness of the annular segment 24 is less than the minimum width of the annular groove 23.

[0037] The sealing end face 21 is provided with an annular groove 23 around the throttling channel 22, and a step structure is formed between the annular groove 23 and the throttling channel 22; the step structure includes a step surface and an annular segment 24 extending axially from the step surface, and the throttling valve port 22a is provided in the annular segment 24.

[0038] In one embodiment, the electronic expansion valve further includes a valve body having a valve cavity, and a valve seat 20 is disposed in the valve body, that is, the valve seat 20 is embedded in the valve body.

[0039] In one embodiment, the valve seat 20 is configured as a valve body.

[0040] Electronic expansion valves are used to control and / or regulate fluid flow in fluid channels. Electronic expansion valves can be configured to control and / or regulate refrigerant flow in air conditioning systems, such as those in residential or automotive air conditioning systems.

[0041] The valve needle 10 should be understood as a valve having a valve piston, particularly a needle-shaped valve piston, which can move linearly to expand and / or reduce the opening of the throttling channel 22, which is a channel for fluid flow, and the opening is also the opening between the outer wall of the valve needle 10 and the annular section 24.

[0042] The electronic expansion valve also includes a coil assembly that cooperates with a rotor assembly to drive linear movement of the valve needle 10 via a lead screw. In this document, "fluid" should be understood as liquid, gas, and / or combinations thereof. The throttling passage 22 of the electronic expansion valve is configured to guide the flow of fluid to be regulated and / or controlled. The throttling passage 22 extends entirely within the valve seat 20.

[0043] The stator of the electric motor with coil assembly is specifically arranged on the outside of the housing above the valve seat 20 and completely surrounds the rotor and housing of the electric motor in the circumferential direction. The rotor, housing, and stator of the electric motor are arranged at least substantially coaxially with each other. The outer wall of the housing is located in the working air gap between the rotor and stator of the electric motor.

[0044] Reference Figure 2 and Figure 3The middle part is through to form a throttling channel 22, and a throttling valve port 22a is formed on the sealing end face 21 of the throttling channel 22; the sealing end face 21 refers to the surface of the valve seat 20 facing the valve needle 10, and the part of the throttling valve port 22a that contacts the valve needle 10 is used to form a sealing pair (such as a conical surface or a flat surface).

[0045] The middle part of the valve seat 20 is designed as a through structure to form a throttling channel 22. There is a valve cavity between the valve seat 20 and the valve needle 10. The refrigerant in the valve cavity will enter the throttling channel 22 through the throttling valve port 22a, and achieve the flow regulation function through the throttling valve port 22a and the valve needle 10, and flow out from the opening on the other side of the throttling channel 22 opposite to the sealing end face 21.

[0046] The sealing end face 21 is provided with an annular groove 23 around the throttling channel 22. That is, the annular groove 23 starts from the sealing end face 21 of the valve seat 20 around the throttling channel 22 and the throttling valve port 22a. In one embodiment, the groove width of the annular groove 23 is smaller than the radius of the sealing end face 21. In this case, the annular groove 23 and the throttling valve port 22a form a double ring structure in the top view. The annular groove 23 is a groove formed by the sealing end face 21. In another embodiment, the annular groove 23 can also be connected to the outer edge of the sealing end face 21. The groove width of the annular groove 23 is larger than the radius of the sealing end face 21. The annular segment 24 is the neck that protrudes from the bottom surface of the annular groove 23.

[0047] A stepped structure is formed between the annular groove 23 and the throttling channel 22. Specifically, the stepped structure includes a stepped surface and an annular segment 24 extending axially from the stepped surface. The throttling valve port 22a is located in the annular segment 24, which is also the groove wall of the annular groove 23. The valve needle 10 can move axially to abut or disengage from the annular segment 24 to close or open the throttling valve port 22a.

[0048] The valve seat 20 is filled with a high-pressure medium. The high-pressure medium exerts a radial compressive force on the inner wall of the annular groove 23, that is, on the outer side of the annular section 24. This allows the valve needle 10 to better contact the annular section 24 when closing the throttle valve port 22a, increasing the radial contact sealing force between the valve needle 10 and the annular section 24. Furthermore, because the wall thickness of the annular section 24 is less than the width of the annular groove 23, the valve seat 20 is usually made of stainless steel. After forming the annular groove 23, the annular section 24 has a flexible effect. When there is a coaxiality deviation in the assembly of the valve needle 10 and the annular section 24, it can adaptively improve the non-uniformity of the contact force between the valve needle 12 and the valve port along the circumference, thereby effectively reducing the leakage problem caused by poor sealing.

[0049] In summary, the technical solution of this utility model provides an annular groove 23 surrounding the throttling valve port 22a in the valve seat 20. The annular groove 23 forms an annular segment 24 in the valve seat 20. The maximum wall thickness of the annular segment 24 is less than the minimum width of the annular groove 23, giving the annular segment 24 a certain degree of flexibility. The medium under high pressure inside the valve seat 20 will generate radial extrusion force on the outer side of the annular segment 24, making the outer peripheral wall of the valve needle 10 and the annular segment 24 better abut against each other, improving the sealing effect between the valve needle 10 and the annular segment 24. When there is a coaxiality deviation in the assembly of the valve needle 10 and the annular segment 24, it can adaptively improve the non-uniformity of the contact force between the valve needle part 12 and the valve port in the circumferential direction, thereby effectively reducing the leakage problem caused by poor sealing.

[0050] Reference Figure 3 Specifically, while satisfying the deformation of the ring section 24, in order to ensure the strength of the ring section 24 and avoid fatigue cracking or plastic deformation caused by improper wall thickness, the minimum inner diameter of the throttle valve port 22a is D0, the maximum outer diameter of the ring section 24 is D1, and 0.4≤(D1-D0) / D0≤0.8.

[0051] (D1-D0) / D0 is the ratio of the wall thickness of the annular section 24 to the minimum inner diameter of the throttle valve port 22a, in order to optimize the sealing performance and structural strength through geometric constraints.

[0052] D0 is the minimum inner diameter of the throttle valve port 22a (i.e., the minimum diameter of the fluid passing through the throttle channel 22, which is also the equivalent diameter at the minimum flow cross section of the throttle channel 22).

[0053] D1 is the maximum outer diameter of the annular section 24 (i.e., the inner diameter of the annular groove 23, with the center being concentric with the throttle valve port 22a and the valve seat 20).

[0054] D1-D0 represent the wall thickness of the ring segment 24.

[0055] The annular section 24 needs to have a certain degree of flexibility (thin wall thickness) in order to deform under the pressure of high pressure medium and adapt to fit the valve needle 10.

[0056] The throttle valve port 22a has different diameters to suit different working conditions. This solution covers a wide range of working pressures (such as medium and low pressure to high pressure) by using the ratio of the wall thickness of the ring section 24 to the minimum inner diameter of the throttle valve port 22a. The wall thickness setting range is determined by using flexible deformation to compensate for the ratio of wall thickness to inner diameter due to assembly deviation.

[0057] In one embodiment, the ratio of wall thickness to inner diameter is constrained to a range of 0.4 to 0.8.

[0058] In one embodiment, the ratio of wall thickness to inner diameter is constrained to a range of 0.45 to 0.55.

[0059] Specifically, if the wall thickness is too small, the structural strength will be insufficient. Therefore, the wall thickness of the ring section 24 cannot be less than 0.4 times the inner diameter of the throttle valve port 22a. Under extremely high pressure conditions, the maximum wall thickness setting range is 0.8 times the inner diameter of the throttle valve port 22a.

[0060] Under normal operating conditions, the wall thickness of the annular section 24 can be set to 0.45 to 0.55 times the inner diameter of the throttle valve port 22a to meet the deformation requirements of the annular section 24. At the same time, in order to ensure the strength of the annular section 24 and avoid fatigue cracking or plastic deformation caused by improper wall thickness, a reasonable wall thickness ratio can avoid sudden changes in flow velocity or eddies at the throttle valve port 22a and maintain stable flow control.

[0061] The constraint range of 0.45 to 0.55 can balance flexibility and strength, meet the diameter range of the typical throttle valve port 22a, ensure that the annular section 24 can adaptively compensate for the coaxiality deviation of the valve needle 10 assembly to reduce leakage, and provide geometric parameter basis for valve design.

[0062] Reference Figure 3 Furthermore, the minimum inner diameter of the throttle valve port 22a is D0, and the height of the annular section 24 is H, with 0.2≤H / D0≤0.5. This range defines the ratio of the depth of the annular groove 23 to the minimum inner diameter of the throttle valve port 22a.

[0063] The height of the annular section 24 is H, which is also the depth of the annular groove 23. Thus, the setting of the annular section 24 can be determined by geometric parameter constraints. This range can be set in combination with the ratio of wall thickness to inner diameter, and can also provide a basic guarantee when other dimensions are unknown.

[0064] H / D0 ensures sufficient axial space to form an effective annular groove structure. If the height is too small (e.g., H / D0 < 0.2), it may result in insufficient wall thickness flexibility, and the deformation during high-pressure media extrusion may be too small (similar to the stiffness problem in thin plate bending theory), failing to adequately compensate for coaxiality deviation.

[0065] Avoid making the annular groove 23 too deep (H / D0 > 0.5). An excessively long neck will reduce the efficiency of the high-pressure medium in transmitting radial deformation, and will also result in structural redundancy and waste of material costs.

[0066] Reference Figure 3 Furthermore, the maximum outer diameter of the ring segment 24 is D1, the maximum inner diameter of the annular groove 23 is D2, and the depth of the annular groove 23 is H, satisfying 0.3≤H / (D2-D1)≤0.7. By limiting the ratio range of the depth H of the annular groove 23 to the difference between the inner and outer diameters of the annular groove 23 (D2-D1), the balance between the structural strength and flexibility of the ring segment 24 can be satisfied through geometric parameter constraints.

[0067] When H / (D2-D1) approaches the lower limit of 0.3, the depth of the annular groove 23 is relatively shallow, and the groove width (D2-D1) is relatively large. At this time, the wall thickness of the annular section 24 is relatively thick, the structural rigidity is strong, and the flexibility is insufficient. The annular section 24 is difficult to compensate for the coaxiality deviation of the valve needle 10 through deformation.

[0068] When H / (D2-D1) approaches the upper limit of 0.7, the annular groove 23 is deeper and the groove width is smaller. At this time, the wall thickness of the annular section 24 is thinner, and the flexibility is enhanced. However, excessive thinning may weaken the structural strength and make it prone to plastic deformation or cracking under high pressure conditions.

[0069] In a preferred embodiment, 0.3 ≤ H / (D2-D1) ≤ 0.4.

[0070] In a preferred embodiment, 0.35 ≤ H / (D2-D1) ≤ 0.5.

[0071] Therefore, by experimenting with the aforementioned proportional range, it was ensured that the annular section 24 possesses sufficient flexibility to adaptively compensate for deviations while maintaining necessary mechanical strength. Furthermore, the depth-to-width ratio of the annular groove 23 directly affects the flow characteristics of the medium in the annular section 24. For example, an excessively large H / (D2-D1) may lead to excessively high local flow velocities, exacerbating the risk of cavitation or erosion; while an excessively small H / (D2-D1) may limit the radial compressive force of the medium on the annular section 24, reducing the sealing contact force.

[0072] That is, by constraining H / (D2-D1), it can be ensured that the annular section 24 can adaptively compensate for the coaxiality deviation of the valve needle 10 assembly and reduce leakage. On this basis, the ratio of the wall thickness of the annular section 24 to the minimum inner diameter of the throttle valve port 22a and the ratio of the depth of the annular groove 23 to the minimum inner diameter of the throttle valve port 22a can be combined. By setting the depth and width of the annular groove 23, it can be ensured that the sealing performance between the valve needle 10 and the annular section 24 is not affected by the assembly deviation, thereby effectively reducing leakage.

[0073] Furthermore, the valve needle 10 includes a needle rod portion 11 and a valve needle portion 12 with an outer diameter smaller than that of the needle rod portion 11. The valve needle portion 12 has a first cone portion 12a. The annular portion 24 has a sealing cone portion 24a and a straight portion 24b. When the valve needle portion 12 contacts the annular portion 24, the first cone portion 12a contacts and seals with the sealing cone portion 24a. The height of the sealing cone portion 24a is H1, which satisfies 0.1≤H1 / H≤0.9.

[0074] H1 represents the height of the sealing cone 24a, and H represents the depth of the annular groove 23, which is also the total height of the annular section 24. H1 is the vertical distance from the connection point of the sealing cone 24a and the straight section 24b to the sealing end face 21, which can be the average of multiple measurements taken at the throttle port 22a of the annular section 24. H can be determined by measuring the vertical distance from the bottom of the annular groove 23 to the sealing end face 21, which can be the average of multiple measurements taken circumferentially along the annular groove 23.

[0075] The depth ratio of the sealing cone 24a and the annular groove 23 is significant in ensuring that the sealing cone 24a can effectively participate in the sealing function, while avoiding a ratio that is too high or too low, which would lead to a decrease in sealing performance or insufficient structural strength.

[0076] Specifically, if H1 / H is less than 0.1, the height of the sealing cone 24a is too low, that is, the sealing contact area is insufficient, and the sealing effect of the valve needle 10 and the annular section 24 is weak.

[0077] If H1 / H is greater than 0.9, the height of the sealing cone 24a will be too high, increasing the manufacturing difficulty and affecting the flexibility of the ring section 24, thus reducing its self-adaptive ability. Therefore, the design of this ratio range is to balance sealing performance and structural rationality.

[0078] If the ratio of the wall thickness of the annular section 24 to the minimum inner diameter of the throttle valve port 22a, the ratio of the minimum inner diameter D0 of the throttle valve port 22a to the depth H of the annular groove 23, and the ratio range of the depth H of the annular groove 23 to the difference between the inner and outer diameters (D2-D1) are known, by reasonably setting the height ratio of the sealing cone 24a, it can be ensured that the contact between the valve needle 10 and the annular section 24 is more uniform, thereby improving the sealing effect and reducing leakage. Furthermore, the flexible design of the annular section 24 enables it to automatically adjust the contact force distribution according to assembly deviations, and the height ratio of the sealing cone 24a further enhances this adaptive capability.

[0079] Furthermore, even if the ratio of the wall thickness of the annular section 24 to the minimum inner diameter of the throttle valve port 22a, the ratio of the minimum inner diameter D0 of the throttle valve port 22a to the depth H of the annular groove 23, and the ratio range of the depth H of the annular groove 23 to the difference between the inner and outer diameters (D2-D1) cannot be determined, the H1 / H ratio range can provide a basic reference for the sealing design of the valve needle 10 and the annular section 24. Even if other parameters are uncertain, the sealing performance can be optimized by adjusting the height ratio of the sealing cone 24a.

[0080] In other words, even in the absence of precise parameters, a preliminary design scheme can be quickly determined by following the ratio range of 0.1≤H1 / H≤0.9, and further optimization can be achieved through subsequent testing, simplifying the design process. In addition, even if there are coaxiality deviations in the assembly, adaptive compensation for the contact force distribution can be achieved by adjusting the height ratio of the sealing cone 24a, thereby reducing leakage.

[0081] Specifically, in this embodiment, the valve needle 10 also includes a second cone portion 12b, the angle between the second cone portion 12b and the axis of the valve needle 10 is smaller than that between the first cone portion 12a, and the gap between the straight section portion 24b and the second cone portion 12b is gradually widened.

[0082] In one embodiment, the needle rod 11 is fixed by connection with the lead screw. The lead screw and nut work together to drive the valve needle 10 to move up and down, adjusting the opening and closing of the valve needle 12 and the throttling valve port 22a, thereby adjusting the flow rate of the refrigeration unit. The valve needle 12 is composed of two cones with different angles (first cone 12a and second cone 12b) to ensure the sealing of the valve needle 12 and the throttling valve port 22a. The first cone 12a abuts against the sealing cone 24a through line contact, which can also play a role in centering the valve needle 10 and improving the coaxiality deviation problem between the valve needle 12 and the valve port assembly.

[0083] The table below shows the test results of the effect of the annular groove structure on the leakage of the electronic expansion valve.

[0084]

[0085] The table above shows a comparison test of the sealing performance of valve seats 20 with and without annular groove 23 under a constant pressure of 1 MPa. The sample size for each group is 10 (where the throttle valve port D0=3.2mm and H=1mm).

[0086] Test results show that, without the annular groove structure, the leakage range is 35~60 ml / min, with an average leakage of 47.5 ml / min; with the annular groove structure, the leakage is significantly reduced to 10~25 ml / min, with an average leakage of only 17.5 ml / min, a reduction of 63.2% (based on average values). Therefore, the annular groove 23 design can significantly improve the sealing performance of the valve seat 20.

[0087] like Figure 4 As shown in the table above, by providing an annular groove 23, the leakage rate of valve seat 20 is reduced from 35~60 ml / min to 10~25 ml / min under a pressure of 1MPa.

[0088] By combining the proportional relationship defined by the above parameters and optimizing the matching relationship between the wall thickness of the annular section 24 and the groove width, a breakthrough improvement in sealing performance was achieved.

[0089] This utility model also proposes a refrigeration device, which includes an electronic expansion valve. The specific structure of the electronic expansion valve is as described in the above embodiments. Since this refrigeration device adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here. The electronic expansion valve is used to control and / or regulate the fluid flow in the fluid channel. The electronic expansion valve can be configured to control and / or regulate the refrigerant flow in the air conditioning circuit of an air conditioning system, such as a household air conditioner or a motor vehicle air conditioning system.

[0090] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. An electronic expansion valve, characterized in that, include: Valve needle; and The valve seat has a sealing end face facing the valve needle, and a through-hole in the middle forms a throttling channel; The throttling channel forms a throttling valve port on the sealing end face, and the sealing end face is provided with an annular groove around the throttling channel. The annular groove and the throttling channel are separated by an annular segment. The valve needle can move axially to abut or disengage from the annular segment to close or open the throttling valve port. The maximum wall thickness of the annular segment is less than the minimum width of the annular groove.

2. The electronic expansion valve according to claim 1, wherein The minimum inner diameter of the throttle valve orifice is D0, and the maximum outer diameter of the annular section is D1, where 0.4 ≤ (D1 - D0) / D0 ≤ 0.

8.

3. The electronic expansion valve according to claim 2, wherein 0.45≤(D1-D0) / D0≤0.

55.

4. The electronic expansion valve of claim 1, wherein The minimum inner diameter of the throttle valve orifice is D0, and the height of the annular section is H, where 0.2 ≤ H / D0 ≤ 0.

5.

5. The electronic expansion valve of claim 1, wherein The maximum outer diameter of the annular segment is D1, the maximum inner diameter of the annular groove is D2, and the height of the annular segment is H, satisfying 0.3≤H / (D2-D1)≤0.

7.

6. The electronic expansion valve according to claim 5, wherein 0.35≤H / (D2-D1)≤0.

5.

7. The electronic expansion valve of claim 5, wherein 0.3≤H / (D2-D1)≤0.

4.

8. The electronic expansion valve of claim 1, wherein The valve needle includes a needle rod portion and a valve needle portion with an outer diameter smaller than the needle rod portion, and the valve needle portion has a first cone portion; The annular section has a sealing cone section and a straight section section. When the valve needle section contacts the annular section section, the first cone section contacts and seals with the sealing cone section. The height of the sealing cone is H1, which satisfies 0.1≤H1 / H≤0.

9.

9. The electronic expansion valve of claim 8, wherein 0.4≤H1 / H≤0.

6.

10. The electronic expansion valve of claim 8, wherein The valve needle package also includes a second cone portion, the angle between the second cone portion and the valve needle axis is smaller than that between the first cone portion, and the gap between the straight section portion and the second cone portion is gradually widened.

11. A refrigeration appliance characterized in that, Includes the electronic expansion valve as described in any one of claims 1 to 10.

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