Electronic expansion valve and air conditioner

Abstract

The utility model discloses an electronic expansion valve and an air conditioner, and relates to the technical field of air conditioners, the electronic expansion valve comprises a valve seat, a nut seat and a valve needle assembly, the valve seat is provided with a valve cavity, and the valve cavity is provided with a fluid inlet, a fluid outlet and a first valve port located between the fluid inlet and the fluid outlet; the nut seat is mounted on the valve seat; the valve needle assembly comprises a large valve needle and a small valve needle which are in transmission connection, the large valve needle is arranged in the valve cavity and used for closing and opening the first valve port, and a second valve port is formed in the large valve needle; the small valve needle comprises an upper valve needle and a lower valve needle which are in transmission connection, the upper valve needle is in threaded connection with the nut seat, and the lower valve needle is used for closing and opening the second valve port; wherein an upper limiting piece is arranged between the large valve needle and the nut seat, and a lower limiting piece is arranged between the upper valve needle and the lower valve needle. According to the technical scheme, the structure of the electronic expansion valve is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioners, and particularly relates to an electronic expansion valve and an air conditioner. Background Art

[0002] An electronic expansion valve is an intelligent control element widely used in refrigeration and air conditioning systems. Its main function is to regulate the flow rate of refrigerant in the system to achieve precise temperature control and efficient energy management.

[0003] A limiting structure is provided in the electronic expansion valve to limit the fully open state and the closed state of the electronic expansion valve. At present, the cooperation of a slip ring and a slide rail is often used to achieve the limit. When the electronic expansion valve is in the fully open state, the slip ring is at the uppermost end of the slide rail and is blocked by a limiting rod on the rotor component; when the electronic expansion valve is in the closed state, the slide rail is at the lowermost end of the slide rail and is blocked by a limiting rod on the rotor component.

[0004] However, the above-mentioned slide rail is a spiral guide rail, and the cooperation structure of the slip ring, the slide rail and the limiting rod is relatively complex. Summary of the Utility Model

[0005] The main object of the utility model is to propose an electronic expansion valve and an air conditioner, aiming to simplify the structure of the electronic expansion valve.

[0006] To achieve the above object, the electronic expansion valve proposed by the utility model includes:

[0007] A valve seat having a valve cavity, the valve cavity having a fluid inlet, a fluid outlet, and a first valve port located between the fluid inlet and the fluid outlet;

[0008] A nut seat mounted on the valve seat; and

[0009] A valve needle assembly including a large valve needle and a small valve needle connected in transmission. The large valve needle is disposed in the valve cavity and is used to close and open the first valve port. A second valve port is provided on the large valve needle; the small valve needle includes an upper valve needle and a lower valve needle connected in transmission. The upper valve needle is threadedly connected to the nut seat, and the lower valve needle is used to close and open the second valve port;

[0010] Wherein, an upper limiting member is provided between the large valve needle and the nut seat, and a lower limiting member is provided between the upper valve needle and the lower valve needle.

[0011] In an embodiment, a positioning step is provided on the inner side wall of the valve seat. When one end of the upper limiting member abuts against the large valve needle, the other end contacts the positioning step.

[0012] In an embodiment, one end of the upper limiting member facing the large valve needle is provided with a convex arc surface.

[0013] In one embodiment, along the axial direction of the upper limit member, the upper limit member is provided with a guiding section and a mating section, and the outer diameter of the guiding section is smaller than that of the mating section.

[0014] In one embodiment, one end of the lower valve needle facing the upper valve needle is provided with a transmission installation groove, a lower limit member is arranged in the transmission installation groove, and the upper valve needle extends into the transmission installation groove.

[0015] In one embodiment, the lower limit member is provided with a receiving groove for receiving the lower end of the lower valve needle, and the bottom of the receiving groove is arranged as a convex arc surface.

[0016] In one embodiment, the valve needle assembly further includes a bearing, a bearing bushing and a first elastic member. The bearing and the bearing bushing are both installed in the transmission installation groove. The bearing is sleeved on the upper valve needle and fixedly connected to the lower valve needle. The bearing bushing is fixedly sleeved on the upper valve needle and contacts the lower end of the bearing;

[0017] A limiting protrusion is arranged on the outer wall of the upper valve needle. One end of the first elastic member abuts against the limiting protrusion, and the other end abuts against the bearing.

[0018] In one embodiment, there is a first gap between the outer wall of the bearing bushing and the inner wall of the lower limit member, and the first gap is 0.05 - 0.1 mm.

[0019] In one embodiment, there is a second gap between the outer wall of the lower limit member and the inner wall of the transmission installation groove, and the second gap is 0.05 - 0.1 mm.

[0020] In one embodiment, the distance between the upper valve needle and the bottom wall of the receiving groove is smaller than the distance between the upper end surface of the lower limit member and the lower bottom surface of the step of the bearing bushing.

[0021] In one embodiment, when the second valve port is in an open state, the distance range between the upper valve needle and the bottom wall of the receiving groove is 0.08 - 0.12 mm.

[0022] In one embodiment, the vertical movement stroke range of the large valve needle is greater than or equal to 2 mm.

[0023] In one embodiment, an adjustment cavity is formed in the large valve needle, the lower valve needle is received in the adjustment cavity, an adjustment groove is arranged in the adjustment cavity, and the lower valve needle is provided with an adjustment protrusion;

[0024] The electronic expansion valve has a fine adjustment stage and a coarse adjustment stage. In the fine adjustment stage, the upper valve needle drives the lower valve needle to move, so that the adjustment protrusion moves along the adjustment groove to adjust the opening of the second valve port.

[0025] In the rough adjustment stage, the adjustment protrusion abuts against the upper groove wall of the adjustment groove, and the upper valve needle drives the lower valve needle, and then drives the large valve needle to move along the valve cavity to adjust the opening of the first valve port.

[0026] In one embodiment, the valve needle assembly further includes a second elastic member, one end of the second elastic member abuts against the nut seat, and the other end of the second elastic member abuts against the large valve needle.

[0027] The utility model also provides an air conditioner, comprising the electronic expansion valve.

[0028] The technical solution of the utility model is to arrange a valve seat, a nut seat and a valve needle assembly in an electronic expansion valve, wherein the valve seat includes a valve cavity, the valve cavity has a fluid inlet, a fluid outlet and a first valve port located between the fluid inlet and the fluid outlet; the nut seat is installed on the valve seat; the valve needle assembly includes a large valve needle and a small valve needle which are transmission-connected, the large valve needle is arranged in the valve cavity and is used to open and close the first valve port, and the large valve needle is provided with a second valve port; the small valve needle includes an upper valve needle and a lower valve needle which are transmission-connected, the upper valve needle is threadedly connected to the nut seat, and the lower valve needle is used to close and open the second valve port; wherein an upper limit member is arranged between the large valve needle and the nut seat, and a lower limit member is arranged between the upper valve needle and the lower valve needle. In this way, when the upper valve needle moves upward, it drives the lower valve needle to move upward, and then drives the large valve needle to move upward to open the first valve port, so that the fluid inlet, the first valve port, and the fluid outlet are connected. When the large valve needle abuts against the upper limit member, the first valve port is fully opened, and the flow rate of the fluid is maximum at this time; when the upper valve needle moves downward, it drives the lower valve needle to move downward. After the lower valve needle closes the second valve port, the upper valve needle abuts against the lower limit member, and the electronic expansion valve is closed at this time. Compared with the prior art, in which a slip ring slide rail is set in the electronic expansion valve to limit the valve needle, the utility model sets an upper limit member and a lower limit member in the electronic expansion valve to limit the large valve needle and the upper valve needle, so that the overall structure of the electronic expansion valve is relatively simple, and the assembly difficulty is also reduced, and it is easy to realize automatic assembly, thereby reducing the assembly cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 the description of the embodiments or the prior art. Obviously, the drawings in the following description 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.

[0030] Figure 1 Schematic cross-sectional structure diagram of an embodiment of an electronic expansion valve provided by the present invention;

[0031] Figure 2 For Figure 1 Schematic structure diagram of an embodiment of the valve seat body in

[0032] Figure 3 For Figure 1 Schematic structure diagram of an embodiment of the upper limit member in

[0033] Figure 4 For Figure 1 Schematic structure diagram of an embodiment of the lower valve needle in

[0034] Figure 5 For Figure 1 Schematic structure diagram of an embodiment of the lower limit member in

[0035] Figure 6 For Figure 1 Schematic structure diagram of an embodiment of a partial valve needle assembly in

[0036] Explanation of the reference numerals in the drawings:

[0037] 100, valve seat; 101, valve seat body; 102, valve seat bushing; 110, valve cavity; 111, fluid inlet; 112, fluid outlet; 113, first valve port; 120, positioning step; 130, first sealing ring;

[0038] 210, nut seat; 220, connecting plate; 230, rotor;

[0039] 300, valve needle assembly; 310, large valve needle; 311, second valve port; 312, adjustment cavity; 313, adjustment groove; 314, transverse flow channel;

[0040] 320, small valve needle; 330, upper valve needle; 331, limiting protrusion; 340, lower valve needle; 341, transmission installation groove; 342, adjustment protrusion; 350, bearing; 360, bearing bushing; 370, first elastic member; 380, second elastic member;

[0041] 400, upper limit member; 410, guiding section; 420, mating section;

[0042] 500. Lower limit member; 510. Receiving groove;

[0043] 600. Upper shell.

[0044] The realization of the purpose, functional characteristics and advantages of the present utility model will be further described with reference to the accompanying drawings in combination with embodiments. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0046] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0047] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot 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, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0048] An electronic expansion valve is an intelligent control element widely used in refrigeration and air-conditioning systems. Its main function is to regulate the refrigerant flow in the system to achieve precise temperature control and efficient energy management.

[0049] A limit structure is provided in the electronic expansion valve to limit the fully open state and the closed state of the electronic expansion valve. At present, the slip ring and the slide rail are often used to achieve the limit. When the electronic expansion valve is in the fully open state, the slip ring is at the uppermost end of the slide rail and is stopped by the limit rod on the rotor component; when the electronic expansion valve is in the closed state, the slide rail is at the lowermost end of the slide rail and is stopped by the limit rod on the rotor component. However, the above-mentioned slide rail is a spiral guide rail, and the matching structure of the slip ring, the slide rail and the limit rod is relatively complicated.

[0050] The utility model provides an electronic expansion valve.

[0051] See also Figure 1 In one embodiment of the utility model, the electronic expansion valve includes a valve seat 100, a nut seat 210 and a valve needle assembly 300, the valve seat 100 has a valve cavity 110, the valve cavity 110 has a fluid inlet 111, a fluid outlet 112 and a first valve port 113 located between the fluid inlet 111 and the fluid outlet 112.

[0052] Specifically, the electronic expansion valve is generally used in air conditioners for regulating the flow of refrigerant. The air conditioner can be a wall mounted unit, a cabinet unit, or an air conditioner in a vehicle. In one embodiment, the valve seat 100 includes a valve seat body 101 and a valve seat sleeve 102. The valve seat sleeve 102 is located below the valve seat body 101. The valve seat body 101 is provided with a fluid inlet 111, and the valve seat sleeve 102 is provided with a fluid outlet 112. The valve cavity 110 also has a first valve port 113. The first valve port 113 is located at one end of the valve seat body 101 close to the valve seat sleeve 102, that is, the first valve port 113 is located between the fluid outlet 112 and the fluid inlet 111. Under certain conditions, the fluid inlet 111 and the fluid outlet 112 can be connected through the first valve port 113, that is, after the fluid enters the valve cavity 110 through the fluid inlet 111, the flow is regulated by the first valve port 113, and finally discharged through the fluid outlet 112.

[0053] The nut seat 210 is installed on the valve seat 100. In one embodiment, the electronic expansion valve further includes an upper shell 600, which is welded to the valve seat body 101, and a receiving cavity is formed in the upper shell 600. The nut seat 210 is located in the receiving cavity and is fixedly connected to the valve seat 100. In one embodiment, the nut seat 210 is welded to the valve seat body 101.

[0054] The valve needle assembly 300 includes a large valve needle 310 and a small valve needle 320 which are transmission-connected. The large valve needle 310 is arranged in the valve cavity 110 and is used to close and open the first valve port 113. The large valve needle 310 is provided with a second valve port 311. The small valve needle 320 includes an upper valve needle 330 and a lower valve needle 340 which are transmission-connected. The upper valve needle 330 is threadedly connected to the nut seat 210, and the lower valve needle 340 is used to close and open the second valve port 311.

[0055] Specifically, the large valve needle 310 is installed in the valve cavity 110 and can move up and down along the cavity wall of the valve cavity 110 under the drive of the small valve needle 320, so as to close and open the first valve port 113, thereby closing and opening the flow passage between the fluid inlet 111, the first valve port 113 and the fluid outlet 112. In an embodiment, to improve the sealing performance of the first valve port 113, a first sealing ring 130 is provided at one end of the valve seat body 101 close to the valve seat bushing 102. When the large valve needle 310 contacts the inner ring wall of the first sealing ring 130, the first valve port 113 is closed; when the large valve needle 310 moves away from the first sealing ring 130, the first valve port 113 is opened. In an embodiment, to improve the sealing stability between the large valve needle 310 and the first sealing ring 130, a sealing step (not shown) is provided on the first sealing ring 130, and the bottom of the large valve needle 310 abuts against the sealing step, so as to prevent the large valve needle 310 from continuing to move downward relative to the first sealing ring 130, providing a lower limit for the up and down movement of the large valve needle 310 and ensuring the sealing stability between the large valve needle 310 and the first sealing ring 130.

[0056] The small valve needle 320 includes an upper valve needle 330 and a lower valve needle 340. The lower valve needle 340 is drivingly connected to the upper valve needle 330 through a transmission member, and at the same time, the lower valve needle 340 is drivingly connected to the large valve needle 310. External threads are provided on the outer wall of the upper valve needle 330, and internal threads are provided on the inner wall of the nut seat 210. The upper valve needle 330 and the nut seat 210 are threadedly connected. In an embodiment, the electronic expansion valve further includes a driving assembly, and the driving assembly includes a rotor 230 and a connecting plate 220 which are connected. The connecting plate 220 is fixedly connected to the upper end of the upper valve needle 330.

[0057] It can be understood that when the electronic expansion valve is powered on, the rotor 230 will rotate, which in turn drives the connecting plate 220 to rotate, which in turn drives the upper valve needle 330 to rotate. Since the upper valve needle 330 is threadedly connected to the nut seat 210, when the upper valve needle 330 rotates, it moves up and down relative to the nut seat 210, which in turn drives the rotor 230 and the connecting plate 220 to move up and down, and at the same time drives the lower valve needle 340 to move up and down. A second valve port 311 is provided on the large valve needle 310, and the up and down movement of the lower valve needle 340 can close and open the second valve port 311.

[0058] The second valve port 311 is in communication with the fluid inlet 111 and the fluid outlet 112. When the second valve port 311 is opened, the fluid inlet 111 and the fluid outlet 112 can be in communication through the second valve port 311; when the second valve port 311 is closed, the flow path between the fluid inlet 111, the second valve port 311, and the fluid outlet 112 is not in communication. Thus, the communication between the fluid inlet 111 and the fluid outlet 112 can be achieved through the first valve port 113 or the second valve port 311, thereby enabling the adjustment of the fluid flow rate.

[0059] In one embodiment, a transverse flow path 314 is provided on the large valve needle 310, and the transverse flow path 314 communicates the fluid inlet 111 and the second valve port 311. In one embodiment, to improve the sealing performance of the second valve port 311, a first sealing surface (not shown) is provided on the lower valve needle 340, and a second sealing surface (not shown) is provided on the side wall of the second valve port 311. When the lower valve needle 340 extends into the second valve port 311 and the first sealing surface contacts the second sealing surface, the second valve port 311 is closed at this time.

[0060] An upper limit member 400 is provided between the large valve needle 310 and the nut seat 210, and a lower limit member 500 is provided between the upper valve needle 330 and the lower valve needle 340.

[0061] Specifically, the upper limit member 400 is used to limit the upward movement of the large valve needle 310. When the upper valve needle 330 moves upward, it drives the lower valve needle 340 to move upward as well, and then drives the large valve needle 310 to move upward. When the large valve needle 310 abuts the upper limit member 400 between the large valve needle 310 and the nut seat 210, the large valve needle 310 is blocked by the upper limit member 400 and cannot continue to move upward. At this time, the first valve port 113 is fully opened. The setting of the upper limit member 400 provides a limit for the upward movement of the valve needle assembly 300 in the electronic expansion valve, avoiding the continuous upward movement of the large valve needle 310 after the first valve port 113 is fully opened.

[0062] The lower limit member 500 is used to limit the downward movement of the upper valve needle 330. When the upper valve needle 330 moves downward, it drives the lower valve needle 340 to move downward as well. When the lower valve needle 340 extends into the second valve port 311 and closes the second valve port 311, the lower valve needle 340 can no longer move downward. At this time, the upper valve needle 330 continues to move downward, pressing the lower limit member 500 between the upper valve needle 330 and the lower valve needle 340. The upper valve needle 330 is blocked by the lower limit member 500 and cannot continue to move downward. The setting of the lower limit member 500 provides a limit for the downward movement of the valve needle assembly 300 in the electronic expansion valve. Compared with the setting without the lower limit member 500, it avoids the wear of the small valve needle 320 and is beneficial to ensuring the accuracy of the small valve needle 320. At the same time, after the lower valve needle 340 closes the second valve port 311, the upper valve needle 330 continues to move downward until it abuts against the lower limit member 500, which also improves the sealing performance of the second valve port 311. In addition, the opening valve pulse of the electronic expansion valve can be determined by the positioning contact between the upper valve needle 330 and the lower limit member 500, making the opening valve pulse have a high consistency, which is beneficial to the stability and consistency of the temperature regulation of the air conditioner.

[0063] The technical solution of the present utility model is to provide a valve seat 100, a nut seat 210 and a valve needle assembly 300 in an electronic expansion valve. The valve seat 100 includes a valve cavity 110 which has a fluid inlet 111, a fluid outlet 112 and a first valve port 113 located between the fluid inlet 111 and the fluid outlet 112. The nut seat 210 is installed on the valve seat 100. The valve needle assembly 300 includes a large valve needle 310 and a small valve needle 320 which are drivingly connected. The large valve needle 310 is arranged in the valve cavity 110 and is used to open and close the first valve port 113, and a second valve port 311 is arranged on the large valve needle 310. The small valve needle 320 includes an upper valve needle 330 and a lower valve needle 340 which are drivingly connected. The upper valve needle 330 is threadedly connected to the nut seat 210, and the lower valve needle 340 is used to close and open the second valve port 311. An upper limit member 400 is arranged between the large valve needle 310 and the nut seat 210, and a lower limit member 500 is arranged between the upper valve needle 330 and the lower valve needle 340. Thus, when the upper valve needle 330 moves upward, it drives the lower valve needle 340 to move upward, and further drives the large valve needle 310 to move upward to open the first valve port 113, so that the fluid inlet 111, the first valve port 113 and the fluid outlet 112 are connected. When the large valve needle 310 abuts against the upper limit member 400, the first valve port 113 is fully opened, and the fluid flow rate is the largest at this time. When the upper valve needle 330 moves downward, it drives the lower valve needle 340 to move downward. After the lower valve needle 340 closes the second valve port 311, the upper valve needle 330 abuts against the lower limit member 500, and the electronic expansion valve is closed at this time. Compared with the prior art in which a slip ring and slide rail are arranged in the electronic expansion valve for valve needle limiting, the present utility model arranges the upper limit member 400 and the lower limit member 500 in the electronic expansion valve to limit the large valve needle 310 and the upper valve needle 330, so that the overall structure of the electronic expansion valve is relatively simple, and at the same time, the assembly difficulty is reduced, and it is easy to realize automatic assembly, thereby reducing the assembly cost.

[0064] Please refer to Figure 2 , in the embodiment of the present utility model, a positioning step 120 is provided on the inner side wall of the valve seat 100. When one end of the upper limit member 400 abuts against the large valve needle 310, the other end contacts the positioning step 120.

[0065] Specifically, a positioning step 120 is provided on the inner side wall of one end of the valve seat body 101 in the valve seat 100, and the positioning step 120 extends in a direction close to the center of the valve seat 100. When the lower end of the upper limit member 400 abuts against the large valve needle 310, the upper end of the upper limit member 400 abuts against the positioning step 120. In one embodiment, the upper limit member 400 is installed at the positioning step 120 of the valve seat body 101, and the upper limit member 400 is in interference fit with the valve seat body 101 to ensure that the upper end of the upper limit member 400 is always in contact with the positioning step 120, so that the upper limit member 400 will not fall off from the positioning step 120. In another embodiment, the upper limit member 400 is in clearance fit with the valve seat body 101. At this time, the large valve needle 310 supports the upper limit member 400, as long as it is ensured that the lower end of the upper limit member 400 can contact the large valve needle 310. In this way, when the large valve needle 310 moves up and down, the upper limit member 400 also moves up and down accordingly. When the upper end of the upper limit member 400 abuts against the positioning step 120, the upward movement of the large valve needle 310 is blocked. In yet another embodiment, the upper limit member 400 is installed on the upper surface of the large valve needle 310. When the large valve needle 310 moves up until the upper limit member 400 abuts against the positioning step 120, the upward movement of the large valve needle 310 is blocked at this time. Here, the installation position of the upper limit member 400 is not limited.

[0066] Please refer to Figure 3 , in the embodiment of the present utility model, one end of the upper limit member 400 facing the large valve needle 310 is provided with a convex arc surface.

[0067] It can be understood that the upper surface of the large valve needle 310 is provided with a flat surface, and the lower surface of the upper limit member 400 is provided with an arc surface. In this way, when the large valve needle 310 contacts the upper limit member 400, it is the contact between the flat surface and the arc surface, which is a line contact at this time. Compared with the way that one end of the upper limit member 400 facing the large valve needle 310 is provided with a flat surface and the upper limit member 400 and the large valve needle 310 are in surface contact, the line contact can reduce the frictional resistance during contact, thereby reducing noise, reducing the noise during the use of the air conditioner, and further improving the use comfort of the air conditioner.

[0068] Please refer to Figure 3 , in the embodiment of the present utility model, along the axial direction of the upper limit member 400, the upper limit member 400 is provided with a guiding section 410 and a matching section 420, and the outer diameter of the guiding section 410 is smaller than the outer diameter of the matching section 420.

[0069] Specifically, the upper limit member 400 is provided with a guiding section 410 and a mating section 420, wherein the guiding section 410 is located above the mating section 420. The valve seat body 101 in the valve seat 100 has a hollow cavity. When installing the upper limit member 400, the upper limit member 400 is placed into the valve seat body 101 from the opening at the bottom end of the valve seat body 101. In one embodiment, the upper limit member 400 is in interference fit with the valve seat body 101. The guiding section 410 with a smaller outer diameter first enters the valve cavity 110 of the valve seat body 101, and the mating section 420 is used to contact the inner wall of the valve seat body 101. The setting of the guiding section 410 makes the installation of the upper limit member 400 easier and more convenient. Of course, in other embodiments, when the upper limit member 400 is in clearance fit with the valve seat body 101, the upper limit member 400 can also be provided with a guiding section 410 and a mating section 420.

[0070] Please refer to Figure 4 , in an embodiment of the present utility model, one end of the lower valve needle 340 facing the upper valve needle 330 is provided with a transmission installation groove 341. A lower limit member 500 is arranged in the transmission installation groove 341, and the upper valve needle 330 extends into the transmission installation groove 341.

[0071] Specifically, in one embodiment, the transmission installation groove 341 is arranged in a "U" shape. The lower limit member 500 is located at the bottom of the transmission installation groove 341, and the transmission installation groove 341 provides an installation position for the lower limit member 500. The lower end portion of the upper valve needle 330 extends into the transmission installation groove 341, so that under certain conditions, the upper valve needle 330 can abut against the lower limit member 500, which also facilitates the realization of the transmission connection between the upper valve needle 330 and the lower valve needle 340.

[0072] Please refer to Figure 5 , in an embodiment of the present utility model, the lower limit member 500 is provided with a receiving groove 510 for receiving the lower end of the lower valve needle 340, and the bottom of the receiving groove 510 is arranged as a convex arc surface.

[0073] Specifically, in one embodiment, the lower limit member 500 is arranged in a "U" shape, and its U-shaped groove is the receiving groove 510 for receiving the lower valve needle 340. The setting of the receiving groove 510 provides guidance for the downward movement of the upper valve needle 330, ensures the accuracy of the downward movement direction of the upper valve needle 330, and thus improves the accuracy of the electronic expansion valve.

[0074] The bottom of the receiving groove 510 is provided with a convex arc surface, that is, the bottom of the receiving groove 510 protrudes towards the direction close to the lower valve needle 340. It can be understood that the lower surface of the upper valve needle 330 is provided with a flat surface, and the bottom of the receiving groove 510 of the lower limiting member 500 is provided with an arc surface. Thus, when the upper valve needle 330 contacts the lower limiting member 500, it is the contact between the flat surface and the arc surface, and at this time it is a line contact. Compared with the bottom of the receiving groove 510 being provided with a flat surface, and the lower limiting member 500 and the upper valve needle 330 being in a surface contact manner, the line contact can reduce the frictional resistance during contact, thereby reducing noise, reducing the noise during the use of the air conditioner, and further improving the use comfort of the air conditioner.

[0075] Please refer to Figure 4 and Figure 6 In the embodiment of the present utility model, the valve needle assembly 300 further includes a bearing 350, a bearing sleeve 360, and a first elastic member 370. The bearing 350 and the bearing sleeve 360 are both installed in the transmission installation groove 341. The bearing 350 is sleeved on the upper valve needle 330 and fixedly connected to the lower valve needle 340. The bearing sleeve 360 is fixedly sleeved on the upper valve needle 330 and contacts the lower end of the bearing 350. A limiting protrusion 331 is provided on the outer wall of the upper valve needle 330. One end of the first elastic member 370 abuts against the limiting protrusion 331, and the other end abuts against the bearing 350.

[0076] Specifically, the settings of the bearing 350 and the bearing sleeve 360 realize the transmission connection between the upper valve needle 330 and the lower valve needle 340. The bearing sleeve 360 is located at the lower end of the upper valve needle 330 and fixedly connected to the upper valve needle 330, so that the bearing sleeve 360 can rotate following the rotation of the upper valve needle 330 and move up and down following the up and down movement of the upper valve needle 330. The bearing 350 is sleeved on the upper valve needle 330, so that the inner ring of the bearing 350 can rotate following the rotation of the upper valve needle 330, thus avoiding the rotational wear of the upper valve needle 330 and being beneficial to ensuring the accuracy of the upper valve needle 330. At the same time, the bearing 350 is fixedly connected to the lower valve needle 340. In one embodiment, the bearing 350 is fixedly welded to the lower valve needle 340. And, the bearing 350 is located above the bearing sleeve 360, that is, there is no fixed connection relationship between the bearing 350 and the bearing sleeve 360, and only the bearing sleeve 360 supports the bearing 350.

[0077] Thus, when the upper valve needle 330 rotates and moves up and down, the bearing 350 rotates following it, the bearing sleeve 360 rotates following it and moves up and down. The up and down movement of the bearing sleeve 360 drives the bearing 350 to move up and down. And because the bearing 350 is fixedly connected to the lower valve needle 340, it drives the lower valve needle 340 to move up and down, thus realizing the transmission connection between the upper valve needle 330 and the lower valve needle 340.

[0078] A first elastic member 370 is further provided in the valve needle assembly 300. The upper end of the first elastic member 370 abuts against the limit protrusion 331 on the upper valve needle 330, and the lower end of the first elastic member 370 abuts against the upper end of the bearing 350. The first elastic member 370 is used to make the upper valve needle 330 tend to move away from the lower limit member 500.

[0079] It can be understood that during the up and down movement of the upper valve needle 330, the upper valve needle 330 does not contact the lower limit member 500. At this time, the first elastic member 370 is slightly compressed or in a natural state. Only after the lower valve needle 340 closes the second valve port 311, when the upper valve needle 330 continues to move downward, the bearing bushing 360 follows and moves downward to disengage from the bearing 350. At this time, since the lower valve needle 340 cannot continue to move downward, the first elastic member 370 is compressed until the upper valve needle 330 abuts against the lower limit member 500. At this time, the electronic expansion valve is in a closed valve state. That is, only in the closed valve state, the upper valve needle 330 contacts the lower limit member 500 and the first elastic member 370 is compressed. When opening the valve, the electronic expansion valve is energized, and the rotor 230 in the electronic expansion valve rotates, thereby driving the upper valve needle 330 to rotate and move upward. The upper valve needle 330 moves away from the lower limit member 500, and the first elastic member 370 resumes deformation. Under the elastic force of the first elastic member 370, a certain distance is maintained between the upper valve needle 330 and the bottom wall of the receiving groove 510 of the lower limit member 500. This distance can be determined according to the actual application of the electronic expansion valve.

[0080] In an embodiment of the present invention, there is a first gap (not shown) between the outer wall of the bearing bushing 360 and the inner wall of the lower limit member 500, and the first gap is 0.05 - 0.1 mm. It can be understood that the bearing bushing 360 is fixed on the upper valve needle 330, so that the bearing bushing 360 will rotate with the rotation of the upper valve needle 330 and move up and down with the up and down movement of the upper valve needle 330. A first gap is provided between the outer wall of the bearing bushing 360 and the inner wall of the lower limit member 500 to meet the requirements of the rotation and up and down movement of the bearing bushing 360 and to avoid friction between the bearing bushing 360 and the lower limit member 500. In one embodiment, the range of the first gap is 0.05 - 0.1 mm.

[0081] In an embodiment of the present invention, there is a second gap (not shown) between the outer wall of the lower limit member 500 and the inner wall of the transmission installation groove 341, and the second gap is 0.05 - 0.1 mm. It can be understood that when the upper valve needle 330 abuts against the lower limit member 500, the lower limit member 500 may rotate with the rotation of the upper valve needle 330. A second gap is provided between the outer wall of the lower limit member 500 and the inner wall of the transmission installation groove 341 to meet the rotation requirements of the lower limit member 500 and to avoid friction between the lower limit member 500 and the transmission installation groove 341. In one embodiment, the range of the second gap is 0.05 - 0.1 mm.

[0082] In an embodiment of the present utility model, the distance between the upper valve needle 330 and the bottom wall of the receiving groove 510 is less than the distance between the upper end surface of the lower limiting member 500 and the lower bottom surface of the step of the bearing bushing 360.

[0083] It can be understood that the lower limiting member 500 has a positive "U" - shaped structure, and the bearing bushing 360 has a positive "T" - shaped structure. Along the axial direction of the upper valve needle 330, the bearing bushing 360 is located above the lower limiting member 500. When the electronic expansion valve is closed, the upper valve needle 330 needs to abut against the lower limiting member 500. By setting the distance between the upper valve needle 330 and the bottom wall of the receiving groove 510 to be less than the distance between the upper end surface of the lower limiting member 500 and the lower bottom surface of the step of the bearing bushing 360, the interference of the bearing bushing 360 on the contact between the upper valve needle 330 and the lower limiting member 500 is avoided.

[0084] In an embodiment of the present utility model, when the second valve port 311 is in an open state, the distance range between the upper valve needle 330 and the bottom wall of the receiving groove 510 is 0.08 - 0.12 mm. Of course, in other embodiments, the distance between the upper valve needle 330 and the bottom wall of the receiving groove 510 can also be 0.06 mm, or 0.13 mm.

[0085] In an embodiment of the present utility model, the up - and - down movement stroke range of the large valve needle 310 is greater than or equal to 2 mm. At this time, the first valve port 113 of the electronic expansion valve is in a fully open state. Of course, in other embodiments, the up - and - down movement stroke of the large valve needle 310 can also be 1.9 mm.

[0086] In an embodiment of the present utility model, the material of the upper limiting member 400 is configured as engineering plastic; or, the material of the upper limiting member 400 is configured as engineering plastic added with carbon fiber or glass fiber; or, the material of the lower limiting member 500 is configured as engineering plastic; or, the material of the lower limiting member 500 is configured as engineering plastic added with carbon fiber or glass fiber. It can be understood that the large valve needle 310 and the small valve needle 320 generally adopt metal materials. By using plastic materials for the upper limiting member 400 and / or the lower limiting member 500, when the valve needle assembly 300 stops up and down, the abutment is between a metal part and a plastic part. Compared with the abutment between metal parts, the noise during abutment is reduced, thereby reducing the use noise of the electronic expansion valve and improving the use comfort of the air conditioner. In one embodiment, the addition ratio of carbon fiber or glass fiber in the engineering plastic is 10% - 30%. Engineering plastics include polyamide, polycarbonate, polyoxymethylene, etc. The specific types of engineering plastics are not limited herein.

[0087] Please refer to Figure 1 and Figure 6In an embodiment of the utility model, an adjusting chamber 312 is formed in the large valve needle 310, and the lower valve needle 340 is accommodated in the adjusting chamber 312. An adjusting groove 313 is provided in the adjusting chamber 312, and an adjusting protrusion 342 is provided on the lower valve needle 340; the electronic expansion valve has a fine adjustment stage and a coarse adjustment stage. In the fine adjustment stage, the upper valve needle 330 drives the lower valve needle 340 to move, and the adjusting protrusion 342 moves along the adjusting groove 313 to adjust the opening of the second valve port 311; in the coarse adjustment stage, the adjusting protrusion 342 abuts against the upper groove wall of the adjusting groove 313, and the upper valve needle 330 drives the lower valve needle 340, and then drives the large valve needle 310 to move along the valve chamber 110 to adjust the opening of the first valve port 113.

[0088] Specifically, the large valve needle 310 has a hollow cavity, that is, an adjustment cavity 312, and a second valve port 311 is formed at the lower portion of the adjustment cavity 312. The lower valve needle 340 is accommodated in the adjustment cavity 312, and the opening and closing of the second valve port 311 are controlled as the lower valve needle 340 moves up and down. An adjustment groove 313 extending along the axial direction of the large valve needle 310 is formed on the inner cavity wall of the adjustment cavity 312, and an adjustment protrusion 342 extending away from the center of the lower valve needle 340 is formed on the outer wall of the lower valve needle 340.

[0089] The valve needle assembly 300 includes a large valve needle 310 and a small valve needle 320 which are connected in a transmission manner. A double valve needle is arranged in the valve needle assembly 300, so that the electronic expansion valve has a fine adjustment stage and a coarse adjustment stage. In the fine adjustment stage, the upper valve needle 330 drives the lower valve needle 340 to move, so that the adjustment protrusion 342 on the lower valve needle 340 moves along the adjustment groove 313, thereby adjusting the opening of the second valve port 311. At this time, the large valve needle 310 is stationary and blocks the first valve port 113. In the fine adjustment stage, the cooperation between the lower valve needle 340 and the second valve port 311 can adjust the flow rate of the fluid more accurately, which is conducive to improving the accuracy of the electronic expansion valve.

[0090] When the lower valve needle 340 moves upward until the adjusting protrusion 342 abuts against the upper groove wall of the adjusting groove 313, at this time, the second valve port 311 is fully opened, and the lower valve needle 340 no longer moves relative to the large valve needle 310. Driven by the upper valve needle 330, the lower valve needle 340 drives the large valve needle 310 to move upward, so that the large valve needle 310 moves along the valve cavity 110, thereby adjusting the opening degree of the first valve port 113. It can be understood that the diameter of the first valve port 113 is larger than that of the second valve port 311, so that the flow rate of the fluid flowing out through the first valve port 113 is larger. The cooperation between the large valve needle 310 and the first valve port 113 can adjust the fluid with a large flow rate. At this time, the electronic expansion valve can realize the function of the solenoid valve. In this way, by arranging the large valve needle 310 and the small valve needle 320 in the electronic expansion valve and using the setting of the double valve needles, the fine adjustment and the coarse adjustment of the flow rate are realized, so that the electronic expansion valve can simultaneously realize the function of the solenoid valve, so that in the air-conditioning system, there is no need to additionally set an electronic expansion valve at the electronic expansion valve, which is beneficial to the simplification of the air-conditioning system.

[0091] Please refer to Figure 1 , in the embodiment of the present invention, the valve needle assembly 300 further includes a second elastic member 380. One end of the second elastic member 380 abuts against the nut seat 210, and the other end abuts against the large valve needle 310.

[0092] Specifically, a second elastic member 380 is further provided in the valve needle assembly 300. The second elastic member 380 is used to make the large valve needle 310 tend to move away from the upper limit member 400. When the large valve needle 310 closes the first valve port 113, the second elastic member 380 is slightly compressed or in a natural state. When the large valve needle 310 is driven to move upward to open the first valve port 113, the second elastic member 380 is compressed as the large valve needle 310 moves upward until the large valve needle 310 abuts against the upper limit member 400. When it is necessary to reduce the flow rate or close the valve, the upper valve needle 330 moves downward, driving the lower valve needle 340 to move downward, so that the adjusting protrusion 342 of the lower valve needle 340 moves away from the upper groove wall of the adjusting groove 313, and the lower valve needle 340 moves downward relative to the adjusting groove 313. At this time, the large valve needle 310 is not driven by the downward movement of the lower valve needle 340. As the adjusting protrusion 342 moves away from the upper groove wall of the adjusting groove 313, the second elastic member 380 loses the external compression force and restores its deformation. Under the elastic force of the second elastic member 380, the large valve needle 310 moves downward along the valve cavity 110 until the large valve needle 310 closes the first valve port 113.

[0093] The present invention also provides an air conditioner, which includes an electronic expansion valve. The specific structure of the electronic expansion valve refers to the above-mentioned embodiment. Since this air conditioner adopts all the technical solutions of the above-mentioned all embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0094] The above are only exemplary embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields shall be included within the patent protection scope of the present utility model.

Claims

1. An electronic expansion valve, characterized in that: include: A valve seat having a valve cavity, wherein the valve cavity has a fluid inlet, a fluid outlet, and a first valve port located between the fluid inlet and the fluid outlet; A nut seat, mounted on the valve seat; as well as A valve needle assembly, comprising a large valve needle and a small valve needle which are connected in a transmission manner, wherein the large valve needle is arranged in the valve cavity and is used to close and open the first valve port, and the large valve needle is provided with a second valve port; the small valve needle comprises an upper valve needle and a lower valve needle which are connected in a transmission manner, wherein the upper valve needle is threadedly connected to the nut seat, and the lower valve needle is used to close and open the second valve port; Wherein, an upper limit member is provided between the large valve needle and the nut seat, and a lower limit member is provided between the upper valve needle and the lower valve needle.

2. The electronic expansion valve according to claim 1, characterized in that: A positioning step is provided on the inner side wall of the valve seat, and when one end of the upper limit member abuts against the large valve needle, the other end contacts the positioning step.

3. The electronic expansion valve according to claim 1, characterized in that: The upper limit member has an end facing the large valve needle and is arranged in a convex arc surface.

4. The electronic expansion valve according to claim 1, characterized in that: The upper limit positioning member is provided with a guide section and a matching section along the axial direction of the upper limit positioning member, and the outer diameter of the guide section is smaller than the outer diameter of the matching section.

5. The electronic expansion valve according to claim 1, characterized in that: A transmission installation groove is provided at one end of the lower valve needle facing the upper valve needle, the lower limit member is provided in the transmission installation groove, and the upper valve needle extends into the transmission installation groove.

6. The electronic expansion valve according to claim 5, characterized in that: The lower limiting member is provided with a receiving groove for receiving the lower end of the lower valve needle, and the groove bottom of the receiving groove is provided in a convex arc surface.

7. The electronic expansion valve according to claim 6, characterized in that: The valve needle assembly also includes a bearing, a bearing sleeve and a first elastic member, the bearing and the bearing sleeve are both installed in the transmission installation groove, the bearing sleeve is arranged on the upper valve needle and fixedly connected to the lower valve needle, and the bearing sleeve is fixedly sleeved on the upper valve needle and contacts the lower end of the bearing; A limiting protrusion is provided on the outer wall of the upper valve needle, one end of the first elastic member abuts against the limiting protrusion, and the other end abuts against the bearing.

8. The electronic expansion valve according to claim 7, characterized in that: There is a first gap between the outer wall of the bearing sleeve and the inner wall of the lower limit member, and the first gap is 0.05-0.1 mm.

9. The electronic expansion valve according to claim 5, characterized in that: There is a second gap between the outer wall of the lower limit member and the inner wall of the transmission installation groove, and the second gap is 0.05-0.1 mm.

10. The electronic expansion valve according to claim 7, characterized in that: The distance between the upper valve needle and the bottom wall of the accommodating groove is smaller than the distance between the upper end surface of the lower limit member and the lower bottom surface of the step of the bearing sleeve.

11. The electronic expansion valve according to claim 6, characterized in that: When the second valve port is in an open state, the distance between the upper valve needle and the bottom wall of the accommodating groove is in a range of 0.08-0.12 mm.

12. The electronic expansion valve according to claim 1, characterized in that: The up and down movement range of the large valve needle is greater than or equal to 2 mm.

13. The electronic expansion valve according to claim 1, characterized in that: An adjusting cavity is formed in the large valve needle, the lower valve needle is accommodated in the adjusting cavity, an adjusting groove is provided in the adjusting cavity, and the lower valve needle is provided with an adjusting protrusion; The electronic expansion valve has a fine adjustment stage and a coarse adjustment stage. In the fine adjustment stage, the upper valve needle drives the lower valve needle to move, so that the adjustment protrusion moves along the adjustment groove to adjust the opening of the second valve port. In the rough adjustment stage, the adjustment protrusion abuts against the upper groove wall of the adjustment groove, and the upper valve needle drives the lower valve needle, and then drives the large valve needle to move along the valve cavity to adjust the opening of the first valve port.

14. The electronic expansion valve according to claim 1, characterized in that: The valve needle assembly also includes a second elastic member, one end of which abuts against the nut seat, and the other end of which abuts against the large valve needle.

15. An air conditioner, characterized in that: Comprising the electronic expansion valve as claimed in any one of claims 1 to 14.

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