Electronic expansion valve and refrigeration equipment

Abstract

The present invention discloses an electronic expansion valve and a refrigeration device. The electronic expansion valve includes a valve housing, a nut, a valve needle, a valve needle sleeve and a valve rod. The valve housing is provided with a valve cavity and a valve port communicating with the valve cavity. The nut is installed inside the valve housing. The valve needle is inserted into the valve port and is in clearance fit with the valve port. The valve needle sleeve is connected to the valve needle. The valve needle sleeve is located inside the cavity of the nut and is in clearance with the inner wall surface of the nut. One end of the valve rod extends into the cavity of the valve needle sleeve and is in driving connection with the valve needle. The valve rod is in clearance fit with the valve needle sleeve. Among them, the clearance between the valve needle sleeve and the inner wall surface of the nut is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port. The fit clearance between the valve rod and the valve needle sleeve is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port. The electronic expansion valve of the present invention can effectively avoid the jamming of the valve needle and can also avoid the influence of eccentricity caused by the coaxiality deviation during the assembly of the valve core assembly on the valve needle.

Description

Technical Field

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

[0002] In a refrigeration cycle system, an electronic expansion valve is usually provided between an outdoor heat exchanger and an indoor heat exchanger. In the refrigeration mode, the electronic expansion valve throttles and depressurizes the refrigerant from the outdoor heat exchanger and then guides it to the indoor heat exchanger; in the heating mode, the electronic expansion valve throttles and depressurizes the refrigerant from the indoor heat exchanger and then guides it to the outdoor heat exchanger. However, during the use of the electronic expansion valve, it is inevitable that small foreign objects enter the system. If the foreign object gets stuck between the valve port and the valve needle, the valve needle will deflect and cause the valve needle to be stuck.

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

[0004] The main object of the present invention is to propose an electronic expansion valve and a refrigeration device, aiming to solve the technical problem that the electronic expansion valve is prone to being stuck.

[0005] To achieve the above object, the electronic expansion valve proposed by the present invention includes a valve housing, a nut, a valve needle, a valve needle sleeve and a valve rod;

[0006] The valve housing is provided with a valve cavity and a valve port communicating with the valve cavity;

[0007] The nut is installed inside the valve housing;

[0008] The valve needle is inserted into the valve port and is in clearance fit with the valve port;

[0009] The valve needle sleeve is connected to the valve needle. The valve needle sleeve is located inside the cavity of the nut and is in clearance with the inner wall surface of the nut;

[0010] One end of the valve rod extends into the cavity of the valve needle sleeve and is in transmission connection with the valve needle. The valve rod is in clearance fit with the valve needle sleeve;

[0011] Wherein, the clearance between the outer wall surface of the valve needle sleeve and the inner wall surface of the nut is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port; the fit clearance between the valve rod and the valve needle sleeve is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port.

[0012] In one embodiment, the valve needle sleeve has a first opening for the valve rod to pass through. The valve rod has an operating end, and the operating end of the valve rod is arranged inside the valve needle sleeve;

[0013] The matching clearance between the valve stem and the valve needle sleeve is the clearance between the valve stem and the inner wall surface of the first opening.

[0014] In one embodiment, the valve needle sleeve includes a cylinder body and a limiting ring provided at one end of the cylinder body away from the valve port, the limiting ring protrudes from the inner wall surface of the cylinder body, and the middle part of the limiting ring forms the first opening.

[0015] In one embodiment, the valve needle sleeve is separately connected to the valve needle, a limiting flange is provided on the peripheral wall of the actuating end of the valve stem, the limiting flange is located in the cylinder body, and the limiting flange is in limiting contact with the limiting ring.

[0016] In one embodiment, the fitting clearance between the valve stem and the valve needle sleeve is larger than the clearance between the valve needle sleeve and the inner wall surface of the nut.

[0017] In one embodiment, the valve needle includes a connecting portion and a needle-shaped portion, the connecting portion is connected to the valve needle sleeve, and the needle-shaped portion is inserted into the valve port and is gap-matched with the valve port.

[0018] In one embodiment, a straight section is formed at a position of the needle-shaped portion adjacent to the connecting portion, a flat-mouth section is formed on one side of the valve port close to the valve needle sleeve, and a gap between an outer wall surface of the straight section and an inner wall surface of the flat-mouth section forms the minimum fitting gap.

[0019] In one embodiment, the end of the valve needle sleeve close to the valve port has a second opening, the connecting portion is installed at the second opening of the valve needle sleeve, and the connecting portion and the valve needle sleeve are interference fit.

[0020] In one embodiment, one end of the valve stem away from the valve needle is threadedly connected to the nut.

[0021] In one embodiment, the electronic expansion valve further includes a buffer spring and a buffer slider, the buffer spring and the buffer slider are arranged in the inner cavity of the valve needle sleeve, the buffer slider abuts against the valve needle, and the valve stem is connected to the buffer slider through the buffer spring.

[0022] In one embodiment, the valve housing includes a valve seat and a valve core seat, the valve seat is provided with a mounting port, the valve core seat is mounted at the mounting port, the valve port is formed on the valve core seat, and the nut is mounted on the valve seat.

[0023] In one embodiment, the electronic expansion valve also includes a connecting piece, the valve seat has a positioning plane arranged away from the valve port, the nut is provided with a slot and a positioning portion, the connecting piece is snapped into the slot and abuts against the positioning plane, and the positioning portion is interference fit with the inner wall surface of the valve seat.

[0024] In one embodiment, the valve needle sleeve is integrally provided with or separately connected to the valve needle.

[0025] The present invention also provides a refrigeration device, which includes an electronic expansion valve. The electronic expansion valve includes a valve housing, a nut, a valve needle, a valve needle sleeve and a valve stem;

[0026] The valve housing is provided with a valve cavity and a valve port communicating with the valve cavity;

[0027] The nut is installed inside the valve housing;

[0028] The valve needle is inserted into the valve port and is in clearance fit with the valve port;

[0029] The valve needle sleeve is connected to the valve needle. The valve needle sleeve is located inside the cavity of the nut and is in clearance with the inner wall surface of the nut;

[0030] One end of the valve stem extends into the inner cavity of the valve needle sleeve and is in transmission connection with the valve needle. The valve stem is in clearance fit with the valve needle sleeve;

[0031] Wherein, the clearance between the outer wall surface of the valve needle sleeve and the inner wall surface of the nut is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port; the fit clearance between the valve stem and the valve needle sleeve is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port.

[0032] In the electronic expansion valve of the present invention, the clearance between the outer wall surface of the valve needle sleeve and the inner wall surface of the nut is made greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port; and the fit clearance between the valve stem and the valve needle sleeve is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port. Then when a foreign object gets stuck between the valve port and the valve needle, even if the valve needle is deflected, due to the fit clearance between the valve stem and the valve needle sleeve being greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port, there is enough movement space between the valve needle sleeve and the valve stem. The valve needle can drive the whole valve needle sleeve to tilt relative to the valve stem towards the inner wall surface side of the nut, and the valve needle sleeve and the valve stem will not be stuck, which affects the up and down movement of the valve needle. And when the valve needle drives the whole valve needle sleeve to tilt relative to the valve stem towards the inner wall surface side of the nut, since there is enough movement space between the valve needle sleeve and the inner wall surface of the nut, the valve needle sleeve will not be stuck with the nut. Furthermore, when a foreign object is stuck between the valve needle and the valve port, due to the fact that when the valve needle and the whole valve needle sleeve are deflected, there is enough deviation movement space on both the valve stem side and the nut side, the valve needle can still move smoothly in the up and down direction, thus effectively avoiding the valve needle from being stuck. At the same time, it can also avoid the influence of eccentricity caused by the coaxiality deviation during the assembly process of the valve core assembly on the valve needle. Description of the Drawings

[0033] 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.

[0034] Figure 1 It is a cross-sectional view of an embodiment of the electronic expansion valve of the present invention, wherein the valve needle is in a state of opening the valve port;

[0035] Figure 2 is Figure 1 a cross-sectional view of the electronic expansion valve in, wherein the valve needle is in a state of closing the valve port;

[0036] Figure 3 is Figure 2 a partial enlarged view of part A in;

[0037] Figure 4 is Figure 2 a partial enlarged view of part B in.

[0038] Explanation of the reference numerals in the drawings:

[0039] Label Name Label Name 100 Valve housing 320 Needle part 110 Valve seat 321 Straight section 111 Valve cavity 400 Valve needle sleeve 112 Mounting port 410 First opening 113 Positioning plane 420 Cylinder body 120 Valve core seat 430 Limit ring 121 Valve port 440 Second opening 1211 Flat port section 500 Valve stem 130 Outer shell 510 Actuating end 200 Nut 520 Limit flange 210 Card slot 600 Buffer spring 220 Positioning part 700 Buffer slider 300 Valve needle 800 Connecting piece 310 Connecting part

[0040] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the drawings. Detailed implementation manners

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0042] 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 invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0043] In addition, if there are descriptions such as "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed 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 such feature. In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. 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 scope of protection required by the present invention.

[0044] The present invention provides an electronic expansion valve, which is applied to a refrigeration device. The refrigeration device can be an air conditioner, a chiller, a refrigerator, a heat pump water heater, or other refrigeration and heating devices. Then, the electronic expansion valve can control the flow rate of the refrigerant in the refrigeration system.

[0045] In the embodiments of the present invention, as Figures 1 to 4 shown, the electronic expansion valve includes a valve housing 100, a nut 200, a valve needle 300, a valve needle sleeve 400, and a valve stem 500. The valve housing 100 is provided with a valve cavity 111 and a valve port 121 communicating with the valve cavity 111; the nut 200 is installed inside the valve housing 100. The valve needle 300 is inserted into the valve port 121 and is in clearance fit with the valve port 121. The valve needle sleeve 400 is connected to the valve needle 300. The valve needle sleeve 400 is located in the inner cavity of the nut 200 and is in clearance with the inner wall surface of the nut 200. One end of the valve stem 500 extends into the inner cavity of the valve needle sleeve 400 and is in transmission connection with the valve needle 300, and the valve stem 500 is in clearance fit with the valve needle sleeve 400. Among them, the clearance between the outer wall surface of the valve needle sleeve 400 and the inner wall surface of the nut 200 (such as Figure 4 shown as D3 - D4) is greater than the minimum fit clearance between the valve needle 300 and the inner wall surface of the valve port 121 (such as Figure 3 shown as D1 - D2); the fit clearance between the valve stem 500 and the valve needle sleeve 400 (such as Figure 4 shown as D5 - D6) is greater than the minimum fit clearance between the valve needle 300 and the inner wall surface of the valve port 121 (such as Figure 3 shown as D1 - D2).

[0046] In this embodiment, the valve housing 100 may specifically include a valve seat 110 and an outer housing 130. The outer housing 130 is connected to the valve seat 110 to hermetically accommodate the spool assembly therein. Then, the inner cavity of the valve seat 110 forms a valve chamber 111, and a valve port 121 may be formed on the valve seat 110. Of course, in some embodiments, the valve housing 100 further includes a spool seat 120. The spool seat 120 is installed on the valve seat 110, and the valve port 121 is formed on the spool seat 120. The nut 200 is installed inside the valve housing 100. The nut 200 may specifically be installed on the outer housing 130, or on the valve seat 110, or on both the outer housing 130 and the valve seat 110 at the same time. The nut 200 and the valve housing 100 may be connected to each other by means of a connecting member, interference fit, snap connection, etc. The nut 200 may be injection-molded from engineering plastic. The valve needle 300 is inserted into the valve port 121 and is in clearance fit with the valve port 121. Specifically, the needle-shaped portion 320 of the valve needle 300 is inserted into the valve port 121, and the outer wall surface of the needle-shaped portion 320 is in clearance fit with the inner wall surface of the valve port 121. In this way, when the valve needle 300 closes the valve port 121, there is a certain gap between the outer wall surface of the needle-shaped portion 320 and the inner wall surface of the valve port 121. In this way, the friction between the valve needle 300 and the valve port 121 can be reduced, and the valve needle 300 can be prevented from being stuck.

[0047] The valve needle 300 is connected to the valve needle sleeve 400. The valve needle 300 and the valve needle sleeve 400 can be integrally formed or separately formed. When the valve needle 300 and the valve needle sleeve 400 are separately formed, the two can be fixedly connected by interference fit, welding or other means. Of course, the valve needle 300 and the valve needle sleeve 400 can be directly connected, and indirect connection through other structural parts should also be within the scope of protection of the connection in this application. The valve needle sleeve 400 is in clearance fit with the inner cavity of the nut 200, so that the valve needle sleeve 400 is guidingly installed in the inner cavity of the nut 200. At the same time, there is a clearance between the valve needle sleeve 400 and the inner wall surface of the nut 200, which reduces the friction between the valve needle sleeve 400 and the inner wall surface of the nut 200. In an embodiment, one end of the valve stem 500 away from the valve needle 300 is threadedly connected to the nut 200, and one end of the valve stem 500 close to the valve port 121 extends into the valve needle sleeve 400 and is drivingly connected to the valve needle 300. One end of the valve stem 500 away from the valve needle 300 is in threaded fit with the nut 200. Since there is a certain clearance in the radial direction of the thread, the operating end 510 of the valve stem 500 close to the valve port 121 can have a certain movement deviation relative to the nut 200 in the radial direction. Thus, the valve stem 500 and the nut 200 can further absorb the concentric deviation to improve the overall coaxiality. The electronic expansion valve specifically further includes a magnetic ring assembly disposed in the valve housing 100. The magnetic ring assembly includes a magnetic ring, a fixing plate and a guiding rod. The fixing plate connects the magnetic ring and the stop rod. One end of the valve stem 500 away from the valve port 121 passes through the middle of the fixing plate. After the electronic expansion valve is powered on, the valve stem 500 is driven to rotate by the magnetic ring assembly, the valve stem 500 is driven to move up and down through the threaded fit between the valve stem 500 and the nut 200, and the valve needle 300 is opened and closed for the valve port 121 through the guiding fit between the valve needle sleeve 400 and the inner cavity of the nut 200 to adjust the refrigerant flow rate.

[0048] It can be understood that the valve needle 300 is inserted into the valve port 121 and is in clearance fit with the valve port 121. The minimum fit clearance between the valve needle 300 and the inner wall surface of the valve port 121 refers to the minimum clearance between the outer wall surface of the needle-shaped portion 320 of the valve needle 300 and the inner wall surface of the valve port 121 when the valve needle 300 is inserted into the valve port 121. The valve stem 500 is in clearance fit with the valve needle sleeve 400. The fit clearance between the valve stem 500 and the valve needle sleeve 400 refers to the clearance between the wall surface of the valve needle sleeve 400 that provides guiding fit to the valve stem 500 and the outer wall surface of the valve stem 500 when the valve stem 500 is installed in the valve needle sleeve 400.

[0049] As Figure 2 shown, the minimum inner diameter of the valve port 121 is set to D1, and the maximum diameter of the valve needle 300 inserted into the valve port 121 is set to D2. As Figure 4As shown in the figure, the inner diameter of the cavity of the nut 200 is set as D3, the outer diameter of the valve needle sleeve 400 is set as D4, the inner diameter of the first opening 410 of the valve needle sleeve 400 is set as D5, and the outer diameter of the operating end 510 of the valve stem 500 is set as D6. That is, the minimum clearance L1 between the valve needle 300 and the inner wall surface of the valve port 121 is equal to D1 - D2; the clearance L2 between the outer wall surface of the valve needle sleeve 400 and the inner wall surface of the nut 200 is equal to D3 - D4; the clearance L3 between the valve stem 500 and the valve needle sleeve 400 is equal to D5 - D6; wherein, L2 is greater than L1, and L3 is greater than L1.

[0050] In the electronic expansion valve of the present invention, the clearance between the outer wall surface of the valve needle sleeve 400 and the inner wall surface of the nut 200 is greater than the minimum clearance between the valve needle 300 and the inner wall surface of the valve port 121; and the clearance between the valve stem 500 and the valve needle sleeve 400 is greater than the minimum clearance between the valve needle 300 and the inner wall surface of the valve port 121. Then when a foreign object gets stuck between the valve port 121 and the valve needle 300, even if the valve needle 300 is deflected, due to the clearance between the valve stem 500 and the valve needle sleeve 400 being greater than the minimum clearance between the valve needle 300 and the inner wall surface of the valve port 121, there is enough movement space between the valve needle sleeve 400 and the valve stem 500. The valve needle 300 can drive the entire valve needle sleeve 400 to tilt relative to the valve stem 500 towards the inner wall surface side of the nut 200, and it will not cause the valve needle sleeve 400 and the valve stem 500 to be stuck and affect the up and down movement of the valve needle 300. And when the valve needle 300 drives the entire valve needle sleeve 400 to tilt relative to the valve stem 500 towards the inner wall surface side of the nut 200, since there is enough movement space between the valve needle sleeve 400 and the inner wall surface of the nut 200, the valve needle sleeve 400 will not be stuck with the nut 200. Furthermore, when a foreign object gets stuck between the valve needle 300 and the valve port 121, due to the fact that when the valve needle 300 and the entire valve needle sleeve 400 are deflected, there is enough deviation movement space on both the valve stem 500 side and the nut 200 side, the valve needle 300 can still move smoothly in the up and down direction, thus effectively avoiding the valve needle 300 from being stuck, and at the same time, it can also avoid the influence of eccentricity caused by the coaxiality deviation during the assembly process of the valve core assembly on the valve needle 300.

[0051] Specifically, please refer to Figure 1 、 Figure 2 and Figure 4 , the valve needle sleeve 400 has a first opening 410 for the valve stem 500 to pass through, the valve stem 500 has an operating end 510, and the operating end 510 of the valve stem 500 is arranged inside the valve needle sleeve 400; the clearance between the valve stem 500 and the valve needle sleeve 400 is the clearance between the valve stem 500 and the inner wall surface of the first opening 410.

[0052] In this embodiment, the action end 510 of the valve stem 500 extends into the valve needle sleeve 400 through the first opening 410 and is in transmission connection with the valve needle 300. It is understandable that the electronic expansion valve further includes a buffer spring 600, which is sleeved on the periphery of the action end 510 of the valve stem 500, and the valve stem 500 is in transmission connection with the valve needle 300 through the buffer spring 600. Due to the arrangement of the buffer spring 600, the gap between the outer wall surface of the action end 510 of the valve stem 500 and the inner wall surface of the inner cavity of the valve needle sleeve 400 must be larger to allow the buffer spring 600 to be installed. Therefore, by setting the first opening 410 on the valve needle sleeve 400, the fitting clearance between the valve stem 500 and the valve needle sleeve 400 is the clearance between the valve stem 500 and the inner wall surface of the first opening 410, that is, the clearance between the valve stem 500 and the inner wall surface of the first opening 410 is larger than the minimum fitting clearance between the valve needle 300 and the inner wall surface of the valve port 121. On the one hand, the guiding fit between the valve stem 500 and the valve needle sleeve 400 is ensured, and the radial shaking of the valve stem 500 is limited by the first opening 410. On the other hand, there is enough clearance between the inner wall surface of the first opening 410 of the valve needle sleeve 400 and the outer wall surface of the actuating end 510 of the valve stem 500. Therefore, when a foreign object is stuck between the valve needle 300 and the valve port 121, the valve needle sleeve 400 can have a certain radial offset relative to the valve stem 500, thereby effectively avoiding the valve needle 300 from getting stuck. In order to facilitate the installation of the valve stem 500 and the buffer spring 600 into the valve needle sleeve 400, the valve needle 500 and the valve needle sleeve 400 are optionally connected separately.

[0053] Further, please refer again to Figure 1 , Figure 2 and Figure 4The valve needle sleeve 400 includes a cylinder body 420 and a stop ring 430 disposed at one end of the cylinder body 420 away from the valve port 121. The stop ring 430 protrudes from the inner wall surface of the cylinder body 420, and the middle of the stop ring 430 forms a first opening 410. The stop ring 430 can be specifically disposed on the end surface of the cylinder body 420 away from the valve port 121. The stop ring 430 protrudes from the inner wall surface of the cylinder body 420, and the first opening 410 is formed by the middle of the stop ring 430. In this way, the action end 510 of the valve stem 500 is matched with the limit ring 430, and the limit ring 430 can radially limit the valve stem 500, thereby preventing the valve stem 500 from shaking significantly in the radial direction and improving the running accuracy of the valve stem 500; at the same time, the setting of the limit ring 430 ensures that there is enough space between the outer wall surface of the action end 510 of the valve stem 500 and the inner wall surface of the cylinder body 420 to accommodate the buffer spring 600. Therefore, by ensuring that the gap between the limit ring 430 and the action end 510 of the valve stem 500 is greater than the minimum matching gap between the valve needle 300 and the inner wall surface of the valve port 121, the valve needle 300 can move smoothly in the up and down directions while ensuring the control accuracy of the valve stem 500, effectively preventing the valve needle 300 from getting stuck.

[0054] In combination with the above-mentioned embodiment in which the valve needle sleeve 400 is provided with the cylinder body 420 and the limiting ring 430, further, as Figure 4 As shown, the valve needle sleeve 400 is separately connected to the valve needle 300, and a limiting flange 520 is provided on the peripheral wall of the action end 510 of the valve stem 500. The limiting flange 520 is located in the cylinder body 420, and the limiting flange 520 is in limiting contact with the limiting ring 430.

[0055] In the present embodiment, the limiting flange 520 is provided in an annular shape. Of course, it can be understood that in other embodiments, the limiting flange 520 can also be provided in an arc shape or a block shape, without specific limitation. The limiting flange 520 can play a role in fixing the buffer spring 600 on the one hand, and can also abut against the limiting ring 430 on the other hand to prevent the action end 510 of the valve stem 500 from escaping from the valve needle sleeve 400. In addition, in the present embodiment, the cross-sectional diameter of the valve needle sleeve 400 is larger than the cross-sectional diameter of the limiting flange 520, so that the friction between the limiting flange 520 and the inner wall surface of the valve needle sleeve 400 can be reduced, so that the valve stem 500 can move smoothly relative to the valve needle sleeve 400. During installation, the valve needle sleeve 400 is first separated from the valve needle 300, and the valve stem 500 can be installed into the cylinder body 420 from the end opposite to the first opening 410, and the limiting flange 520 abuts against the limiting ring 430, and finally the valve needle sleeve 400 is fixedly connected to the valve needle 300.

[0056] In one embodiment, please refer again to Figure 4, the clearance between the valve stem 500 and the valve needle sleeve 400 is greater than the clearance between the valve needle sleeve 400 and the inner wall surface of the nut 200. That is, L3 is greater than L2. Then when a foreign object gets stuck between the valve needle 300 and the valve port 121, the concentric deviation can be absorbed first by the clearance between the valve needle 300 and the valve needle sleeve 400. At the same time, the guiding effect between the valve needle sleeve 400 and the inner wall surface of the nut 200 can also be ensured. That is, while avoiding the jamming of the valve needle 300, the accuracy of the entire valve needle 300 assembly is guaranteed. Of course, in other embodiments, the clearance between the valve stem 500 and the valve needle sleeve 400 can also be made smaller than the clearance between the valve needle sleeve 400 and the inner wall surface of the nut 200. That is, the nut 200 does not play a guiding role for the valve needle sleeve 400, and the nut 200 and the valve needle sleeve 400 do not actually contact. Therefore, even if a concentric deviation occurs between the valve needle sleeve 400 and the nut 200 during assembly, the clearance between the nut 200 and the valve needle sleeve 400 can absorb this concentric deviation.

[0057] In fact, as Figures 1 to 3 shown, the valve needle 300 includes a connecting portion 310 and a needle-like portion 320. The connecting portion 310 is connected to the valve needle sleeve 400, and the needle-like portion 320 is inserted into the valve port 121 and is in clearance fit with the valve port 121. Further, one end of the valve needle sleeve 400 close to the valve port 121 has a second opening 440. The connecting portion 310 is installed at the second opening 440 of the valve needle sleeve 400, and the connecting portion 310 is in interference fit with the valve needle sleeve 400. In this way, the connection stability between the valve needle sleeve 400 and the valve needle 300 can be ensured. And by making the valve needle sleeve 400 and the valve needle 300 into two separate structures, it is more convenient for the injection molding of the valve needle 300, so that the top surface of the connecting portion 310 can be injection molded more smoothly, and the friction force between the valve needle 300 and the buffer slider 700 can be reduced. The valve needle 300 is inserted into the valve port 121 through the needle-like portion 320 and is in clearance fit with the valve port 121. Then the minimum clearance between the valve needle 300 and the inner wall surface of the valve port 121 is the minimum clearance between the outer wall surface of the needle-like portion 320 and the inner wall surface of the valve port 121. It ensures the overall system stability of the electronic expansion valve and is more conducive to adjusting the refrigerant flow rate.

[0058] Further, please refer to Figure 3, a straight section 321 is formed at a position where the needle-like portion 320 is adjacent to the connecting portion 310, a flat section 1211 is formed on one side of the valve port 121 close to the valve needle sleeve 400, and the gap between the outer wall surface of the straight section 321 and the inner wall surface of the flat section 1211 forms the minimum mating gap. In this way, the gap between the straight section 321 of the valve needle 300 and the flat section 1211 of the valve port 121 is small, and the refrigerant flows evenly through this gap. Thus, it is easier for the electronic expansion valve to control the micro-flow domain. And making the gap between the outer wall surface of the straight section 321 and the inner wall surface of the flat section 1211 form the minimum mating gap, that is, the gap between the outer wall surface of the valve needle sleeve 400 and the inner wall surface of the nut 200 is greater than the gap between the outer wall surface of the straight section 321 and the inner wall surface of the flat section 1211; the mating gap between the valve stem 500 and the valve needle sleeve 400 is greater than the gap between the outer wall surface of the straight section 321 and the inner wall surface of the flat section 1211. Then it can avoid the situation that when foreign objects are caught in the minimum gap between the valve needle 300 and the valve port 121, the valve needle 300 moves up and down smoothly due to the deflection of the valve needle sleeve 400, and further ensure the operation stability of the electronic expansion valve.

[0059] In one embodiment, please refer to Figure 1 , Figure 2 and Figure 4 , the electronic expansion valve further includes a buffer spring 600 and a buffer slider 700. The buffer spring 600 and the buffer slider 700 are arranged in the inner cavity of the valve needle sleeve 400. The buffer slider 700 abuts against the valve needle 300, and the valve stem 500 is connected to the buffer slider 700 through the buffer spring 600.

[0060] Specifically, the nut 200 is provided with an installation hole extending along its axial direction. The valve stem 500 passes through the installation hole and is rotatably connected to the nut 200. The valve stem 500 includes a guide rod section and a threaded rod section. The installation hole includes a guide hole section adapted to the guide rod section and a threaded hole section adapted to the threaded rod section. The guide rod section and the guide hole section are in interference fit or clearance fit, and the threaded rod section and the threaded hole section are in threaded fit.

[0061] The valve needle 300 assembly may be composed only of a valve needle sleeve 400, a valve stem 500, a valve needle 300, a buffer slider 700, and a buffer spring 600, which enables the valve needle 300 assembly to have fewer components, thus achieving the effect of cost savings, but is not limited to this. The valve stem 500, nut 200, and valve needle 300 are coaxially arranged. The buffer spring 600 and the buffer slider 700 are both located within the valve needle sleeve 400. The buffer slider 700 is opposite and spaced from the operating end 510 of the valve stem 500. The buffer spring 600 is disposed between the buffer slider 700 and the operating end 510 of the valve stem 500 to connect the buffer slider 700 and the operating end 510 of the valve stem 500. Specifically, the buffer spring 600 is a compression spring. In this way, when the valve stem 500 moves axially relative to the valve needle sleeve 400, the valve stem 500 can drive the buffer slider 700 to rotate through the buffer spring 600, while the valve needle 300 remains stationary, avoiding the rotation of the valve needle 300 relative to the valve port 121 and causing wear. After the valve stem 500 moves axially to abut against the valve needle sleeve 400, the valve stem 500 can drive the valve needle 300 to move together through the valve needle sleeve 400, thereby realizing the control of the opening degree of the valve port 121, that is, realizing the control of the flow rate of the electronic expansion valve. Optionally, the valve stem 500, buffer spring 600, buffer slider 700, and valve needle sleeve 400 are coaxially arranged, which can ensure good coaxiality of the valve core assembly.

[0062] In fact, for the convenience of installing the valve stem 300, buffer spring 600, and buffer slider 700 into the valve needle sleeve 400, the valve needle sleeve 400 and the valve needle 300 are detachably connected. In this way, during installation, first separate the valve needle sleeve 400 and the valve needle 300, so that the buffer spring 600, buffer slider 700, and valve stem 500 are installed into the valve needle sleeve 400 through the opening at the end of the valve needle sleeve 400 close to the valve needle 300, and finally fixedly connect the valve needle 300 and the valve needle sleeve 400.

[0063] In the embodiment of the present invention, the buffer slider 700 abuts against the valve needle 300, enabling the buffer slider 700 to be rotatable relative to the valve needle 300, which can avoid the rotation of the valve needle 300 relative to the valve port 121 and the rotation of the valve needle sleeve 400 relative to the mounting hole of the nut 200, thereby avoiding wear of the valve needle 300 and the valve needle sleeve 400. The buffer slider 700 can be made of a material with high lubricity, which can reduce the friction force between the buffer slider 700 and the valve needle 300, thereby reducing the wear caused by the rotation of the buffer slider 700 relative to the valve needle 300. Optionally, the buffer slider 700 is made of a non-metallic material, for example, but not limited to, the buffer slider 700 is made of a plastic material. By using a non-metallic buffer slider 700, the friction force between the buffer slider 700 and the valve needle 300 made of a metal material can be reduced, and further the wear caused by the rotation of the buffer slider 700 relative to the valve needle 300 can be reduced.

[0064] In one embodiment, if Figure 1 and Figure 2 As shown, the valve housing 100 includes a valve seat 110 and a valve core seat 120. The valve seat 110 is provided with a mounting port 112, the valve core seat 120 is mounted at the mounting port 112, a valve port 121 is formed on the valve core seat 120, and the nut 200 is mounted on the valve seat 110. The valve core seat 120 and the valve seat 110 can be connected by welding, thereby ensuring the sealing reliability of the valve core seat 120 and the valve seat 110. In other embodiments, the valve seat 110 and the valve core seat 120 can also be integrally formed. By installing the nut 200 on the side of the valve seat 110 away from the installation port 112, the installation of the nut 200 on the side close to the valve port 121 is more stable compared to installing the nut 200 on the housing 130, and the shaking of the cylinder of the nut 200 toward the valve port 121 can be effectively avoided, thereby avoiding the problems of eccentricity and friction between the nut 200 and the valve core assembly, and further avoiding the valve core assembly from getting stuck due to coaxiality when moving in the nut 200, and the overall noise of the electronic expansion valve can be effectively reduced, thereby improving the overall service life.

[0065] For further information, please refer to Figure 2 and Figure 4 The electronic expansion valve further comprises a connecting piece 800, the valve seat 110 has a positioning plane 113 disposed away from the valve port 121, the nut 200 is provided with a slot 210 and a positioning portion 220, the connecting piece 800 is engaged in the slot 210 and abuts against the positioning plane 113, and the positioning portion 220 is interference fit with the inner wall surface of the valve seat 110. The connecting piece 800 can be specifically an annular metal connecting piece 800. The annular metal connecting piece 800 is embedded in the slot 210. The nut 200 can be made of plastic material, and engineering resin can be selected, and is integrally injection molded with the annular metal connecting piece 800. The nut 200 is fixed to the positioning plane 113 disposed away from the valve port 121 of the valve seat 110 through the annular metal connecting piece 800, and is interference fit with the inner wall surface of the valve seat 110 through the positioning portion 220. In this way, the axial movement of the nut 200 is limited by the annular metal connecting plate 800, and the circumferential rotation of the nut 200 is limited by the interference fit of the positioning portion 220, thereby making the connection between the nut 200 and the valve seat 110 more stable and preventing the nut 200 from shaking or deflecting due to vibration or coaxial deviation.

[0066] In one embodiment, if Figure 1 , Figure 2 and Figure 4As shown, the nut 200 has an extension portion extending towards the valve port 121. This extension portion extends to abut or be close to the valve port 121. The extension portion is sleeved around the periphery of the valve needle sleeve 400 and is in guiding cooperation with the valve needle sleeve 400 and the valve needle 300. By sleeving the extension portion around the periphery of the valve needle sleeve 400 and being in guiding cooperation with the valve needle sleeve 400 and the valve needle 300, the extension portion can be used to guide the valve needle 300 assembly, so that there is no need to additionally provide a guide sleeve or make the valve core seat 120 extend upward to form a guide sleeve, thereby reducing components and simplifying the overall structure. And due to the shielding effect of the wall surface of the extension portion, the refrigerant can be prevented from directly impacting the valve needle 300, thereby reducing noise. In addition, since the connection stability of the nut 200 is high, the valve needle 300 is guided by the extension portion of the nut 200, and since the valve stem 500 is also guided by the nut 200, the coaxiality of the valve stem 500, the valve needle sleeve 400, and the nut 200 can be better ensured, making the overall coaxiality high, and further making the operation accuracy of the entire electronic expansion valve higher and the use smoother, and further reducing the probability of the valve needle 300 getting stuck.

[0067] The present invention also proposes a refrigeration device. This refrigeration device includes an electronic expansion valve. The specific structure of the electronic expansion valve refers to the above-mentioned embodiments. Since this refrigeration device adopts all the technical solutions of the above-mentioned all embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one. This refrigeration device can be an air conditioner, a refrigerator, a freezer, a heat pump water heater or other refrigeration and heating devices. Then the electronic expansion valve can control the refrigerant flow rate in the refrigeration system.

[0068] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An electronic expansion valve, characterized in that, it includes: a valve housing, the valve housing is provided with a valve cavity and a valve port communicating with the valve cavity; a nut, installed inside the valve housing; a valve needle, inserted into the valve port and in clearance fit with the valve port; a valve needle sleeve, connected to the valve needle, the valve needle sleeve is located inside the nut cavity and is in clearance with the inner wall surface of the nut; a valve stem, one end extends into the inner cavity of the valve needle sleeve and is in transmission connection with the valve needle, the valve stem is in clearance fit with the valve needle sleeve; wherein, the clearance between the outer wall surface of the valve needle sleeve and the inner wall surface of the nut is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port; the fit clearance between the valve stem and the valve needle sleeve is greater than the minimum fit clearance between the valve needle and the inner wall surface of the valve port.

2. The electronic expansion valve according to claim 1, characterized in that, the valve needle sleeve has a first opening for the valve stem to pass through, the valve stem has an operating end, and the operating end of the valve stem is arranged inside the valve needle sleeve; the fit clearance between the valve stem and the valve needle sleeve is the clearance between the valve stem and the inner wall surface of the first opening.

3. The electronic expansion valve according to claim 2, characterized in that, the valve needle sleeve includes a cylindrical body and a limiting ring arranged at one end of the cylindrical body away from the valve port, the limiting ring protrudes from the inner wall surface of the cylindrical body, and the middle of the limiting ring forms the first opening.

4. The electronic expansion valve according to claim 3, characterized in that, the valve needle sleeve is detachably connected to the valve needle, a limiting flange is arranged on the peripheral wall of the operating end of the valve stem, the limiting flange is located inside the cylindrical body, and the limiting flange is in limiting contact with the limiting ring.

5. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, the fit clearance between the valve stem and the valve needle sleeve is greater than the clearance between the valve needle sleeve and the inner wall surface of the nut.

6. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, the valve needle includes a connecting portion and a needle-shaped portion, the connecting portion is connected to the valve needle sleeve, the needle-shaped portion is inserted into the valve port and is in clearance fit with the valve port.

7. The electronic expansion valve according to claim 6, characterized in that, a straight section is formed at a position of the needle-shaped portion adjacent to the connecting portion, a flat section is formed on one side of the valve port close to the valve needle sleeve, and the clearance between the outer wall surface of the straight section and the inner wall surface of the flat section forms the minimum fit clearance.

8. The electronic expansion valve according to any one of claim 6, characterized in that, one end of the valve needle sleeve close to the valve port has a second opening, the connecting portion is installed at the second opening of the valve needle sleeve, and the connecting portion is in interference fit with the valve needle sleeve.

9. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, one end of the valve stem away from the valve needle is threadedly connected to the nut.

10. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, The electronic expansion valve further includes a buffer spring and a buffer slider. The buffer spring and the buffer slider are disposed in the inner cavity of the valve needle sleeve. The buffer slider abuts against the valve needle, and the valve stem is connected to the buffer slider through the buffer spring.

11. The electronic expansion valve according to any one of claims 1 to 4, characterized in that the valve housing includes a valve seat and a valve core seat. An installation opening is provided on the valve seat, the valve core seat is installed at the installation opening, the valve port is formed on the valve core seat, and the nut is installed on the valve seat.

12. The electronic expansion valve according to claim 11, characterized in that the electronic expansion valve further includes a connecting piece. The valve seat has a positioning plane disposed away from the valve port. The nut is provided with a card slot and a positioning portion. The connecting piece is clamped in the card slot and abuts against the positioning plane. The positioning portion is in interference fit with the inner wall surface of the valve seat.

13. The electronic expansion valve according to claim 1, characterized in that the valve needle sleeve and the valve needle are integrally provided or separately connected.

14. A refrigeration device, characterized in that it includes the electronic expansion valve according to any one of claims 1 to 13.

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