Electronic Expansion Valve

Abstract

the small spindle is in movably sealing engagement with the inner wall of the guide hole via the first inner sealing ring, a sealing part is formed at the position where the small spindle and the small valve port are in close contact with each other, and one end of the small spindle remote from the sealing part is located in the valve chamber, and the valve chamber is connected to the small valve port, and the maximum diameter of the sealing part is smaller than the outer diameter of the first inner sealing ring or the inner diameter of the first inner sealing ring. In this embodiment, the small spindle is always subjected to the pressure difference between the inlet fluid and the outlet fluid while it is stationary or moving, causing the screw to rotate to the same position relative to the nut sleeve, thereby eliminating the problem of errors in the position of the spindle relative to the valve port.

Description

[Technical Field]

[0001] This application claims priority to the patent application filed with the State Intellectual Property Office of the People's Republic of China on December 12, 2022, bearing application number 202211591592.X, entitled "Electronic Expansion Valve", the patent application filed with the State Intellectual Property Office of the People's Republic of China on March 21, 2023, bearing application number 202310307328.7, entitled "Electronic Expansion Valve", the patent application filed with the State Intellectual Property Office of the People's Republic of China on March 21, 2023, bearing application number 202320590688.8, entitled "Electronic Expansion Valve", and the patent application filed with the State Intellectual Property Office of the People's Republic of China on March 21, 2023, bearing application number 202320575377.4, entitled "Electronic Expansion Valve".

[0002] The present invention relates to the technical field of electronic expansion valves, and more particularly to electronic expansion valves. [Background technology]

[0003] Currently, electronic expansion valves are commonly used to adjust the flow rate of fluids in various cooling and heating equipment, such as air conditioners, refrigerators, and heat pump water heaters. Electronic expansion valves are typically composed of a valve seat, a spindle, and other components, and the movement of the spindle adjusts the opening of the valve port to achieve flow control.

[0004] Chinese patent publication number CN216742910U discloses an electronic expansion valve, comprising: a valve seat member; a valve sleeve connected to the valve seat member; a spindle member provided within the valve seat member, the spindle member including a main body and a small spindle, the main body having a small valve port, the small spindle being movably provided to adjust the opening degree of the small valve port; a driving member provided within the valve seat member and the chamber of the valve sleeve, the region located between the structure of the driving member within the valve sleeve and the inner wall of the valve sleeve forming a rotor chamber; the driving member drivingly connected to the small spindle; and a balancing passage communicating the rotor chamber and the small valve port, and an internal balancing valve. Due to this structure, the fluid force experienced by the small spindle when it closes the small valve port or moves up and down is substantially zero. When the small spindle moves up and down, it also experiences a frictional force exerted by the first sealing ring. The direction of the frictional force changes as the direction of movement of the small spindle changes, and the frictional force acting on the small spindle is transmitted to the screw. When the screw moves upward relative to the nut assembly, the upper surface of the thread on the nut sleeve and the upper surface of the thread on the screw come into contact with each other; when the screw moves downward relative to the nut sleeve, the lower surface of the thread on the nut sleeve and the lower surface of the thread on the screw come into contact with each other. As a result, when the screw rotates to the same position relative to the nut sleeve during the downward or upward movement process, the position of the screw relative to the nut sleeve will be affected by the thread clearance and will cause an error in the position of the spindle relative to the valve port, which will further reduce the accuracy of the flow control of the electronic expansion valve.The friction force experienced by the small spindle during the up and down movement process cannot resolve the error in the position of the spindle relative to the valve port, and at the same time, the change in the direction of the friction force will increase the instability of the screw movement process.Therefore, a perfectly balanced small spindle is disadvantageous in solving the problem of the error in the position of the spindle relative to the valve port when the screw rotates to the same position relative to the nut sleeve of the electronic expansion valve during the downward or upward movement process. Summary of the Invention

[0005] The present invention provides an electronic expansion valve for solving the problem that when the screw in the conventional electronic expansion valve moves downward or upward and rotates at the same position relative to the nut sleeve, an error occurs in the position of the spindle relative to the valve port.

[0006] To solve the above problems, the present invention includes a valve seat portion and a spindle member provided in the chamber of the valve seat portion, which includes a large spindle portion and a small spindle. The large spindle portion includes a spindle body, and the spindle body has a small valve port. The small spindle is used to close the small valve port. The spindle body has a guide hole, and a first inner sealing ring is provided between the small spindle and the inner wall of the guide hole. The small spindle is movably sealed and engaged with the inner wall of the guide hole through the first inner sealing ring. A sealing portion is formed at the position where the small spindle abuts against the small valve port. The valve chamber where one end of the small spindle away from the sealing portion is located communicates with the small valve port. Here, the first inner sealing ring is located in the first inner sealing groove on the outer wall of the small spindle, and the maximum diameter of the sealing portion is smaller than the outer diameter of the first inner sealing ring, or the first inner sealing ring is located in the first inner sealing groove on the inner wall of the guide hole, and the maximum diameter of the sealing portion is smaller than the inner diameter of the first inner sealing ring. The present invention provides an electronic expansion valve.

[0007] Furthermore, when the first inner sealing ring is located in the first inner sealing groove on the inner wall of the guide hole, if the frictional force between the first inner sealing ring and the outer wall of the small spindle is F1, and the resultant force of the fluid acting forces in the valve seat portion received by the small spindle is F2, then F1 < F2. When the first inner sealing ring is located in the first inner sealing groove on the outer wall of the small spindle, if the frictional force between the first inner sealing ring and the inner wall of the guide hole is F1, and the resultant force of the fluid acting forces in the valve seat portion received by the small spindle is F2, then F1 < F2.

[0008] In addition, the electronic expansion valve further includes a screw assembly, the screw assembly includes a small elastic member, one end of the small elastic member abuts against the small spindle, when the small valve port is closed, the acting force applied by the small elastic member to the small spindle toward the small valve port is a sealing preload, and if the minimum value of the sealing preload is F3, then F1 + F2 <F3である。

[0009] Furthermore, the small spindle has a sealing segment, which axially movably passes through the guide hole, the sealing segment has a first inner sealing groove, a first inner sealing ring is attached to the first inner sealing groove, and the outer wall of the first inner sealing ring abuts against the inner wall of the guide hole.

[0010] Furthermore, the small spindle has a tapered segment, and a sealing portion is formed at the location where the tapered segment and the small valve orifice are in close contact with each other.

[0011] The large spindle portion further includes a small gasket disposed within the spindle body, the small valve port includes a through hole in the small gasket, the inner wall of the through hole and the tapered segment of the small spindle are sealingly engaged, and the through hole has a chamfered surface at one end facing the first inner sealing ring.

[0012] The small spindle further has a position limiting segment, which is located on one side of the guide hole away from the small valve orifice and is connected to the sealing segment, and the valve chamber in which the position limiting segment is located is connected to the small valve orifice.

[0013] Furthermore, the valve seat portion has a large valve port, the spindle body is used to close the large valve port, and a balancing passage is provided in the spindle body, so that the valve chamber at one end of the spindle body remote from the large valve port is connected to the large valve port through the balancing passage, and the valve chamber at one end of the small spindle remote from the sealing portion is connected to the small valve port through the balancing passage, and the large valve port is connected to the small valve port.

[0014] In addition, the large spindle portion further includes a limiting ring, the limiting ring is fixed within the spindle body, the small spindle penetrates into the spindle body, and the limiting ring and the small spindle are engaged to prevent the separation of the small spindle and the large spindle portion.

[0015] In addition, the spindle body further has a limiting hole, the inner diameter of the guide hole is smaller than the inner diameter of the limiting hole, the limiting ring is fixed within the limiting hole, and one end of the small spindle away from the sealing portion is located within the limiting hole.

[0016] Compared with the prior art, the present invention has the following beneficial effects. (1) During the process of the small spindle being stationary or moving, it always receives the pressure difference generated between the inlet fluid and the outlet fluid, and the balance cannot be maintained. The pressure difference is finally transmitted to the screw of the electronic expansion valve. When the screw moves downward or upward and rotates to the same position with respect to the nut sleeve of the electronic expansion valve, it is advantageous for solving the problem that an error occurs in the position of the spindle with respect to the valve port. (2) Assuming that the frictional force received by the small spindle is F1 and the resultant force of the fluid acting forces within the valve seat portion received by the small spindle is F2, then F1 < F2. In the same fluid flow state, regardless of whether the small spindle moves upward or downward, it can be ensured that the resultant force of F1 and F2 received by the small spindle is always in one direction. (3) Assuming that the minimum value of the sealing pre-pressure towards the small valve port applied by the small spindle is F3, then F1 + F2 < F3. Therefore, when the small spindle closes the small valve port, the resultant force of F1 and F2 can be prevented from being sufficient to push the small spindle open. (4) The tapered segment of the small spindle and the small valve port are in sealing engagement. The tapered segment can perform flow rate adjustment. The small valve port supports the tapered segment. When the small spindle seals the small valve port, its position is stable. In the low-pulse small flow rate adjustment state of the small spindle of the electronic expansion valve, the accuracy of the inflection point on the flow rate curve is high, the pulse range where the inflection point is located is narrow, and the flow rate adjustment accuracy of the small spindle can be ensured. (5) One end of the through hole facing the first inner sealing ring has a chamfered surface, which makes it easier for the small spindle to penetrate into the small valve opening and at the same time strengthens the sealing performance with the small spindle and reduces wear on the small valve opening caused by the small spindle during sealing. [Brief explanation of the drawings]

[0017] The drawings in the specification that form a part of this application are intended to provide a further understanding of the application, and the schematic examples and their descriptions in the application are intended to help interpret the application and are not intended to unduly limit the application.

[0018] [Figure 1] 1 is a structural schematic diagram of an electronic expansion valve provided in an embodiment of the present invention; [Figure 2] 2 shows an enlarged view of a portion of the electronic expansion valve of FIG. 1. [Figure 3] 1 shows another structural schematic diagram of the large gasket in the electronic expansion valve provided in an embodiment of the present invention. [Figure 4] 2 is a schematic diagram of a portion of the structure of the electronic expansion valve of FIG. 1. [Figure 5] 2 shows a cross-sectional view of a spindle body in the electronic expansion valve of FIG. 1. [Figure 6] A schematic diagram of the flow rate curve of the electronic expansion valve of FIG. [Figure 7] 1 is a schematic diagram illustrating the engagement between the screw and the nut body in the electronic expansion valve according to the embodiment of the present invention;

[0019] Here, the above drawings include the following reference numerals: 100 valve seat portion, 101 large valve port, 102 flow hole, 103 third passage, 104 valve seat ring, 105 sealing portion, 110 large gasket, 111 sealing surface, 112 second annular step, 113 third annular step, 114 second chamfer, 115 third chamfer, 120 large valve seat, 121 pressure ring, 1211 first chamfer, 130 small valve seat, 131 first annular step, 140 reinforcing sealing ring, 151 first outer sealing ring, 152 second outer sealing ring 200 spindle member, 210 large spindle part, 211 small valve port, 212 side opening, 213 guide hole, 214 first passage, 215 flow chamber, 220 small spindle, 221 position limiting segment, 222 sealing segment, 223 annular stop member, 224 tapered segment, 231 first inner sealing ring, 232 second inner sealing ring, 240 spindle body, 241 limiting hole, 242 assembly groove, 243 avoidance groove, 250 limiting ring, 260 small gasket, 261 chamfered segment, 270 limiting sleeve, 280 large elastic member, 300 screw assembly, 310 screw, 320 assembly sleeve, 330 bearing, 340 bushing, 350 small elastic member, 400 valve pipe, 500 nut assembly, 501 fourth passage, 510 nut body, 520 connecting plate. DETAILED DESCRIPTION OF THE INVENTION

[0020] The technical aspects of the embodiments of the present invention will be described clearly and completely below with reference to the drawings in the embodiments of the present invention, but it is clear that the described embodiments are only some of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present invention.

[0021] As shown in Figures 1 to 7, an embodiment of the present invention provides an electronic expansion valve including: a valve seat portion 100 having a large valve port 101; and a spindle member 200 disposed in a chamber of the valve seat portion 100, the spindle member 200 including a large spindle portion 210 and a small spindle portion 220, the large spindle portion 210 having a small valve port 211, the large spindle portion 210 being used to open and close the large valve port 101, and the small spindle portion 220 being used to open and close the small valve port 211.

[0022] When this embodiment is adopted, the small spindle 220 moves in the axial direction to adjust the opening of the small valve port 211, thereby realizing small flow rate adjustment, and the large spindle part 210 blocks or avoids the large valve port 101, thereby realizing large flow rate conduction and blocking. Here, when the electronic expansion valve is in a closed state, the small spindle 220 blocks the small valve port 211, and the large spindle part 210 blocks the large valve port 101. When the electronic expansion valve is in a flow rate control state, the small spindle 220 moves in the axial direction to adjust the opening of the small valve port 211, and the large spindle part 210 blocks the large valve port 101, thereby realizing small flow rate adjustment. When the electronic expansion valve is in a fully open state, the small spindle 220 moves until it completely avoids the small valve port 211, and then moves the large spindle part 210 in the axial direction until it completely avoids the large valve port 101, thereby realizing the fully open state.

[0023] Here, the large spindle part 210 includes a spindle body 240, the spindle body 240 has a small valve port 211, the small spindle 220 is used to close the small valve port 211, the spindle body 240 has a guide hole 213, and a first inner sealing ring 231 is provided between the small spindle 220 and the inner wall of the guide hole 213, the small spindle 220 is movably sealed and engaged with the inner wall of the guide hole 213 via the first inner sealing ring 231, and the small spindle 220 and the small valve port 211 are in contact with each other. A sealing portion 105 is formed at the contact position, and the valve chamber where one end of the small spindle 220 away from the sealing portion 105 is located is connected to the small valve port 211, where the first inner sealing ring 231 is located in the first inner sealing groove on the outer wall of the small spindle 220, and the maximum diameter of the sealing portion 105 is smaller than the outer diameter of the first inner sealing ring 231, or the first inner sealing ring 231 is located in the first inner sealing groove on the inner wall of the guide hole 213, and the maximum diameter of the sealing portion 105 is smaller than the inner diameter of the first inner sealing ring 231.

[0024] In the attachment method of the two types of the first inner sealing rings 231 in this aspect, during the process where the small spindle 220 is stationary or moving, it always receives the pressure difference generated between the inlet fluid and the outlet fluid, and the balance cannot be maintained. When the pressure difference is finally transmitted to the screw of the electronic expansion valve, during the process where the screw moves downward or upward, when the screw rotates to the same position with respect to the nut sleeve of the electronic expansion valve, an error occurs in the position of the spindle with respect to the valve port. To solve this problem, the maximum diameter of the sealing portion 105 is smaller than the outer diameter of the first inner sealing ring 231, or the maximum diameter of the sealing portion 105 is smaller than the inner diameter of the first inner sealing ring 231.

[0025] Here, the large spindle portion 210 and the valve seat portion 100 may be provided integrally, or the large spindle portion 210 may be fixedly connected to the valve seat portion 100, or the large spindle portion 210 may belong to a part of the valve seat portion 100, or the large spindle portion 210 may be movable.

[0026] Here, during the process where the small spindle 220 moves, if the frictional force received by the small spindle 220 is F1, and the resultant force of the acting forces of the fluid in the valve seat portion 100 received by the small spindle 220 is F2, then F1 < F2. That is, in this aspect, the acting force of the fluid on the small spindle 220 is always greater than the frictional force received by the small spindle 220. Thus, regardless of whether it is the valve opening process or the valve closing process, the resultant force of the frictional force and the fluid force received by the small spindle 220 is always in one predetermined direction, for example, upward or downward, and no change occurs in the resultant force direction of the forces received by the small spindle 220 during movement. When the electronic expansion valve is assembled, an assembly gap (as shown in FIG. 7) inevitably exists in the axial direction of the small spindle 220. If a change occurs in the resultant force direction of the forces received by the small spindle 220 during movement, axial play (the play distance is the distance of the assembly gap) occurs in the small spindle 220, making the valve opening and closing unstable and affecting the accuracy of the flow rate curve. In this aspect, by restricting F1 < F2, the problem of axial play occurring in the small spindle 220 is avoided.

[0027] Specifically, the small spindle 220 has a tapered segment 224, and a sealing portion 105 is formed at the position where the tapered segment 224 and the small valve port 211 abut. Furthermore, the tapered segment 224 of the small spindle 220 and the small valve port 211 are sealed together, the tapered segment 224 can adjust the flow rate, the small valve port 211 supports the tapered segment 224, the position of the small spindle 220 is stable when sealing the small valve port 211, and when the small spindle 220 of the electronic expansion valve is in a low pulse small flow rate adjustment state, the inflection point on the flow rate curve is highly accurate and the pulse range in which the inflection point is located is narrow, ensuring high flow rate adjustment accuracy of the small spindle 220.

[0028] Here, the large spindle part 210 further includes a small gasket 260 disposed within the spindle body 240, and the small valve port 211 includes a through hole within the small gasket 260, with the inner wall of the through hole sealingly engaged with the tapered segment 224 of the small spindle 220, and one end of the through hole facing the first inner sealing ring 231 having a chamfered surface. The chamfered surface at the end of the through hole facing the first inner sealing ring 231 facilitates insertion of the small spindle 220 into the small valve port 211, while at the same time enhancing the sealing performance with the small spindle 220 and reducing wear on the small valve port 211 caused by the small spindle 220 during sealing.

[0029] Here, the valve seat portion 100 has a large valve port 101, and the spindle body 240 is used to close the large valve port 101. The spindle body 240 is provided with a balancing passage, such that the valve chamber at one end of the spindle body 240 remote from the large valve port 101 communicates with the large valve port 101 through the balancing passage, the valve chamber at one end of the small spindle 220 remote from the sealing portion 105 communicates with the small valve port 211 through the balancing passage, and the large valve port 101 communicates with the small valve port 211. The balancing passage reduces the fluid pressure difference between both ends of the spindle member 200, making it easier to open and close the valve port. The provision of the large valve port 101 allows the electronic expansion valve to achieve a high flow rate when the large valve port 101 is opened due to its relatively large diameter.

[0030] In a specific embodiment, the valve seat portion 100 has a large valve port 101, the large spindle portion 210 includes a spindle body 240 and a small gasket 260 arranged in the spindle body 240, the small gasket 260 has a small valve port 211, the inner surface of the small valve port 211 has a straight body segment, the small spindle 220 has a tapered segment 224, which is used to seal and engage with the inner surface of the straight body segment, and the large spindle portion 210 is used to open and close the large valve port 101.

[0031] In this embodiment, the tapered surface of the tapered segment 224 of the small spindle 220 engages with the inner surface of the straight body segment of the small gasket 260 to achieve reliable sealing of the small valve port 211, and in this embodiment, the tapered surface is provided on the tapered segment 224 of the small spindle 220 rather than in the small gasket 260, so that, compared to the prior art, the tapered surface for sealing is on the outer surface rather than the inner surface. In this way, it is easier to precisely process and measure the tapered surface, which reduces the difficulty of production, improves the production yield, and reduces the production cost of the electronic expansion valve.

[0032] Here, the diameter of the straight body segment is smaller than the diameter of the large end of the tapered segment 224 and larger than the diameter of the small end of the tapered segment 224. In this way, after the tapered segment 224 is inserted into the straight body segment, a part of the tapered segment 224 is located inside the straight body segment and another part is located outside the straight body segment, resulting in a better sealing effect.

[0033] The inner surface of the small valve orifice 211 further has a chamfered segment 261, and the taper angle of the chamfered segment 261 is greater than the taper angle of the tapered segment 224. The chamfered segment 261 can remove burrs from the edge of the small valve orifice 211 and also acts as a guide for the tapered segment 224 to penetrate into the straight cylindrical segment.

[0034] In this embodiment, the spindle body 240 has a guide hole 213, and the small spindle 220 has a sealing segment 222 that axially moves through the guide hole 213. The sealing segment 222 has a tapered segment 224, and the diameter of the small end of the tapered segment 224 is smaller than the diameter of the constant diameter segment of the sealing segment 222. In this way, the engagement between the guide hole 213 and the sealing segment 222 provides a guide and restriction to the movement of the small spindle 220.

[0035] In this embodiment, the spindle member 200 further includes a first inner sealing ring 231, the sealing segment 222 has a first inner sealing groove, the first inner sealing ring 231 is mounted in the first inner sealing groove, and the outer wall of the first inner sealing ring 231 abuts against the inner wall of the guide hole 213. In this way, the first inner sealing ring 231 can perform a sealing function to prevent internal leakage.

[0036] In this embodiment, due to the presence of the tapered segment 224, the force-receiving area of ​​the small valve port 211 of the small spindle 220 in the sealed position is smaller than the force-receiving area within the guide hole 213 of the small spindle 220, so that the resultant force acting on the small spindle 220 by the fluid communicated with the large valve port 101 is always directed toward the small valve port 211.

[0037] In an electronic expansion valve, when fluid enters through the flow passage hole 102 and exits from the large valve port 101, the fluid pressure in the flow passage hole 102 is greater than the fluid pressure in the large valve port 101. The acting force of the fluid in the flow passage hole 102 on the small spindle 220 is upward (i.e., in the direction away from the large valve port 101) and relatively large. The resultant force of the acting forces of the fluid in the large valve port 101 on the small spindle 220 is downward (i.e., in the direction towards the large valve port 101). The total acting force F2 of the fluid in the electronic expansion valve on the small spindle 220 is upward. The frictional force received by the small spindle 220 when opening the valve is F1 and is downward, and when closing the valve, F1 is upward, and F1 < F2. In this way, regardless of whether the small spindle 220 opens or closes the valve, the resultant force of F1 and F2 is always upward, that is, the resultant force received by the small spindle 220 is in a single direction and does not change, avoiding the problem of axial play occurring during the movement of the small spindle 220.

[0038] Correspondingly, when the fluid flows out from the flow passage hole 102 and flows into the large valve port 101, the fluid pressure in the flow passage hole 102 is less than the fluid pressure in the large valve port 101. The acting force of the fluid in the flow passage hole 102 on the small spindle 220 is upward (i.e., in the direction away from the large valve port 101). The resultant force of the acting forces of the fluid in the large valve port 101 on the small spindle 220 is downward (i.e., in the direction towards the large valve port 101) and the force is relatively large. The total acting force F2 of the fluid in the electronic expansion valve on the small spindle 220 is downward. The frictional force received by the small spindle 220 when opening the valve is F1 and is downward, and when closing the valve, F1 is upward, and F1 < F2. In this way, regardless of whether the small spindle 220 opens or closes the valve, the resultant force of F1 and F2 is always downward, that is, the resultant force received by the small spindle 220 is in a single direction and does not change, avoiding the problem of axial play occurring during the movement of the small spindle 220.

[0039] The spindle member 200 further includes a second inner sealing ring 232. The large spindle portion 210 has a second inner sealing groove. The second inner sealing ring 232 is attached to the second inner sealing groove, and the outer wall of the second inner sealing ring 232 abuts against the inner wall of the valve seat portion 100. The second inner sealing ring 232 can seal the circumferential direction of the large spindle portion 210 to avoid internal leakage. The dimension of the sealing region between the spindle body 240 and the large valve port 101 is substantially equal to the outer diameter of the second inner sealing ring 232, ensuring force-receiving balance within the valve chamber of the spindle body 240.

[0040] The electronic expansion valve further includes a screw assembly 300. The screw assembly 300 includes a small elastic member 350. One end of the small elastic member 350 abuts against the small spindle 220. When the small valve port 211 is closed, the acting force exerted by the small elastic member 350 on the small spindle 220 towards the small valve port 211 is the sealing preload. If the minimum value of the sealing preload is F3, then F1 + F2 < F3.

[0041] Specifically, the screw assembly 300 further includes a screw 310, an assembly sleeve 320, and a bearing 330. The screw 310 is connected to the inner ring of the bearing 330. The outer ring of the bearing 330 is located within the assembly sleeve 320. One end of the small elastic member 350 and the bearing 330 are in a limiting engagement, and the other end of the small elastic member 350 abuts against the position-limiting segment 221.

[0042] The small elastic member 350 can improve the reliability of the small spindle 220 closing the small valve port 211 and can also perform a buffering and protective function. The valve seat ring 104 can guide the reciprocating movement of the assembly sleeve 320. Since F1 + F2 < F3, it avoids the small spindle 220 being pushed up by the acting force exerted by the fluid on the small spindle 220, ensuring the reliability of closing the small valve port 211.

[0043] Here, the valve seat portion 100 has a valve seat ring 104 , and the assembly sleeve 320 moves back and forth along the inner wall of the valve seat ring 104 , and the valve seat ring 104 can act as a guide for the assembly sleeve 320 .

[0044] The principle of use of this embodiment is as follows. When the fluid enters through the through hole 102 and flows out through the small valve port 211, the small spindle 220 between the first inner sealing ring 231 and the sealing part 105 is subjected to the force of the high-pressure fluid entering through the through hole 102, and moves along the axial direction of the electronic expansion valve and away from the small valve port 211, while the small spindle 220 between the first inner sealing ring 231 and the sealing part 105 is subjected to the force of the low-pressure fluid at the small valve port 211, and moves along the axial direction of the electronic expansion valve and towards the small valve port 211. Due to the installation of the tapered segment 224 of the small spindle 220, if the resultant force of the force of the high-pressure fluid and the force of the low-pressure fluid is F2, F2 will always move along the axial direction of the electronic expansion valve and away from the small valve port 211. When the small spindle 220 moves toward the small valve port 211, the first inner sealing ring 231 in the small spindle 220 experiences a frictional force F1 along the axial direction of the electronic expansion valve and away from the small valve port 211. The directions of F1 and F2 are the same, and the resultant force of F1 and F2 experienced by the small spindle 220 is along the axial direction of the electronic expansion valve and away from the small valve port 211. When the small spindle 220 moves away from the small valve port 211, the first inner sealing ring 231 in the small spindle 220 experiences a frictional force F1 along the axial direction of the electronic expansion valve and close to the small valve port 211. Since F1 is smaller than F2, the resultant force of F1 and F2 experienced by the small spindle 220 is along the axial direction of the electronic expansion valve and away from the small valve port 211. Therefore, whether the small spindle 220 is moving upward or downward, the direction of the resultant force of the fluid acting on the small spindle 220 and the frictional force is always the same, and the resultant force of the fluid acting on the small spindle 220 and the frictional force acts on the screw, keeping the upper surface of the screw thread always in contact with the upper surface of the nut sleeve thread. When the fluid flows out of the through hole 102 and enters the small valve port 211, whether the small spindle 220 is moving upward or downward, the direction of the resultant force of the fluid acting on the small spindle 220 and the frictional force is always the same, and both are along the axial direction of the electronic expansion valve and toward the small valve port 211. The resultant force of the fluid acting on the small spindle 220 and the frictional force acts on the screw, keeping the lower surface of the screw thread always in contact with the lower surface of the nut thread.

[0045] The side wall of the valve seat portion 100 has a flow hole 102, the large spindle portion 210 has a side opening 212, and the side opening 212 is connected to the flow hole 102. The electronic expansion valve has a closed state, a flow rate adjusting state, and a fully open state. In the closed state, the small spindle 220 seals the small valve port 211, and the small valve port 211 and the side opening 212 are not connected. The large spindle portion 210 seals the large valve port 101, and the large valve port 101 is not connected to the small valve port 101. In the flow rate adjusting state, the large spindle portion 210 seals the large valve port 101, and the small spindle 220 moves axially to adjust the opening of the small valve port 211, so that the large valve port 101 communicates with the side opening 212 via the small valve port 211. In the fully open state, the large spindle portion 210 opens the large valve port 101, so that the large valve port 101 directly communicates with the flow rate adjusting state and the large flow rate conducting and blocking functions.

[0046] Here, the large spindle portion 210 has a guide hole 213, which is located on one side of the small valve orifice 211, away from the large valve orifice 101. The small spindle 220 passes through the guide hole 213 so as to be able to move back and forth, and is sealed and engaged with the inner wall of the guide hole 213, so that the movement of the small spindle 220 can be guided by the guide hole 213.

[0047] The spindle member 200 further includes a first inner sealing ring 231, the small spindle 220 has a first inner sealing groove, the first inner sealing ring 231 is mounted in the first inner sealing groove, and the outer wall of the first inner sealing ring 231 abuts against the inner wall of the valve seat 100, thereby achieving a sealing effect to prevent internal leakage.

[0048] The spindle member 200 further includes a second inner sealing ring 232, the large spindle portion 210 has a second inner sealing groove, the second inner sealing ring 232 is mounted in the second inner sealing groove, and the outer wall of the second inner sealing ring 232 abuts against the inner wall of the valve seat portion 100, so that the second inner sealing ring 232 performs a sealing function for the large spindle portion 210.

[0049] The small spindle 220 and the large spindle portion 210 are axially limitedly engaged, and the electronic expansion valve further includes a screw assembly 300, which is fixedly connected to the small spindle 220 so as to drive the small spindle 220 and the large spindle portion 210 to reciprocate, thereby realizing the opening and closing operations of the small valve port 211 and the large valve port 101.

[0050] For example, as shown in FIG. 6, the ordinate in FIG. 6 represents the flow rate of the electronic expansion valve, and the abscissa represents the valve port opening, the stroke of the spindle, or the stroke of the screw assembly 300. The position where the abscissa value is approximately 320 is the dividing line between the small valve port 211 and the large valve port 101. Here, when the abscissa value is less than 320, the small valve port 211 is individually opened and closed to achieve a precise small flow rate regulation function (in this case, with a throttling effect). When the abscissa value is greater than 320, the large valve port 101 is gradually opened, and the flow rate increases rapidly to achieve a large flow rate function (the large valve port 101 is fully opened and has no throttling effect). Of course, the actual flow rate characteristic curve of the electronic expansion valve is not limited to the form shown in FIG. 6 and can be specifically adjusted according to operating conditions and customer requirements. The adjustment method is to change the dimensions of the valve port, the shape of the inner wall of the valve port, the dimensions of the spindle, the shape of the outer wall of the spindle, etc. In the prior art, the gasket at the valve port has a tapered surface that engages with the small spindle to adjust the flow rate, but the small spindle does not have a tapered surface. When the small spindle is closed and pressed against the small valve port, the tapered surface of the gasket is easily deformed, causing the position of the small spindle to move downward, making the position of the inflection point unstable and resulting in low flow rate adjustment accuracy. In this structure, a tapered surface for flow rate adjustment is provided on the small spindle 220, which stabilizes the inflection point and increases the accuracy of flow rate adjustment.

[0051] In this application, the large spindle part 210 includes a spindle body 240 and a limiting ring 250. The spindle body 240 has a limiting hole 241 and a guide hole 213. The inner diameter of the guide hole 213 is smaller than the inner diameter of the limiting hole 241. The limiting ring 250 is fixed in the limiting hole 241. The small spindle 220 passes through the guide hole 213 so as to be reciprocable, and is sealingly engaged with the inner wall of the guide hole 213. The limiting ring 250 and the small spindle 220 are fastened and engaged to form the small spindle 220. 20 and the large spindle portion 210 from separating. In this way, the engagement between the small spindle 220 and the limiting ring 250 limits the relative movement distance between the small spindle 220 and the spindle body 240, preventing the two from separating. Furthermore, when the small spindle 220 moves, it opens and closes the small valve orifice 211, and the small spindle 220 moves and moves the large spindle portion 210, thereby opening and closing the large valve orifice 101.

[0052] Specifically, the small spindle 220 includes a limiting segment 221, a sealing segment 222, and an annular stopper 223. The sealing segment 222 passes through the guide hole 213, and the end of the sealing segment 222 is used to open and close the small valve port 211. The limiting segment 221 is located within the restricting hole 241, and the annular stopper 223 is fixed to the outer surface of the limiting segment 221. The annular stopper 223 is located between the bottom wall of the restricting hole 241 and the limiting ring 250. The outer diameter of the annular stopper 223 is larger than the inner diameter of the guide hole 213 and the inner diameter of the limiting ring 250, and the outer diameter of the limiting segment 221 is smaller than the inner diameter of the restricting hole 241. The engagement between the annular stopper 223 and the limiting ring 250 limits the relative movement distance between the small spindle 220 and the valve spindle body 240.

[0053] Here, a gap is provided between the annular stopper member 223 and the bottom wall of the restricting hole 241, thereby ensuring smooth movement of the small spindle 220.

[0054] There is a limiting step inside the limiting hole 241, and the end face of the limiting ring 250 abuts against the limiting step, and the outer wall of the limiting ring 250 and the inner wall of the limiting hole 241 are interference-fitted and / or welded. By adopting this structure, a reliable connection between the limiting ring 250 and the spindle body 240 is achieved.

[0055] In this embodiment, the small spindle 220 has an integral structure, which makes it easy to process and ensures good coaxiality. The spindle body 240 has an integral structure, which makes it easy to process and assemble, and which makes it easy to ensure coaxiality between the spindle body 240 and the small spindle 220. The spindle body 240 reciprocates along the valve seat 100 and is sealingly engaged with the inner wall of the valve seat 100. This allows the spindle body 240 to be guided by the inner wall of the valve seat 100.

[0056] The electronic expansion valve further includes a screw assembly 300, which is fixedly connected to the position limiting segment 221 so as to drive the small spindle 220 and the large spindle portion 210 to move back and forth, and there is a gap between the outer wall of the screw assembly 300 and the inner wall of the limiting ring 250 to avoid the generation of resistance force.

[0057] In the present application, the large spindle portion 210 has a first passage 214, one end of which is connected to the large valve port 101 and the other end of which is connected to a chamber on one side of the large spindle portion 210, away from the large valve port 101. The first passage 214 equalizes the fluid pressure intensity at both axial ends of the large spindle portion 210 and the small spindle 220, thereby avoiding or reducing the influence of fluid pressure on the movement of the large spindle portion 210 and the small spindle 220, and making it easier to open and close the large valve port 101 and the small valve port 211. Furthermore, providing the first passage 214 in the large spindle portion 210, rather than in the small spindle 220, facilitates machining. Because the diameter of the small spindle 220 is relatively small, the strength of the small spindle 220 is also prevented from being affected by opening holes.

[0058] Specifically, the large spindle portion 210 includes a spindle body 240 and a limiting ring 250, the limiting ring 250 is fixed within the spindle body 240, the small spindle 220 penetrates into the spindle body 240, and the limiting ring 250 and the small spindle 220 are engaged to prevent the small spindle 220 and the large spindle portion 210 from separating, and the spindle body 240 has a first passage 214.

[0059] Furthermore, the spindle body 240 has a restricting hole 241 and a guide hole 213, the inner diameter of the guide hole 213 is smaller than the inner diameter of the restricting hole 241, the restricting ring 250 is fixed in the restricting hole 241, the small spindle 220 passes through the guide hole 213 so as to be able to move back and forth and is sealingly engaged with the inner wall of the guide hole 213, the first passage 214 is connected to the restricting hole 241, that is, the first passage 214 is connected to the restricting hole 241, thereby realizing communication between the chambers at both ends of the large spindle part 210.

[0060] In this embodiment, the electronic expansion valve further includes a screw assembly 300, which is fixedly connected to the small spindle 220 so as to drive the small spindle 220 and the large spindle section 210 to move back and forth. The through hole in the limiting ring 250 forms a second passage, one end of which is connected to the first passage 214, and the other end of the second passage is connected to a chamber on one side of the large spindle section 210 away from the large valve port 101. By providing the second passage, the limiting ring 250 and the screw assembly 300 are prevented from obstructing the flow of fluid.

[0061] In this embodiment, the electronic expansion valve further includes a valve pipe 400 and a nut assembly 500, both of which are fixedly connected to the valve seat 100. The nut assembly 500 is located in a chamber of the valve pipe 400. The chamber between the outer wall of the nut assembly 500 and the inner wall of the valve pipe 400 is a rotor chamber. The first passage 214 is connected to the rotor chamber. The nut assembly 500 is threadedly engaged with the screw assembly 300, which is driven by electromagnetic force. When the screw assembly 300 rotates, it moves axially through thread engagement, thereby opening and closing the valve port.

[0062] Furthermore, the valve seat 100 has a third passage 103, and the nut assembly 500 has a fourth passage 501, where the large valve orifice 101, the first passage 214, the second passage, the third passage 103, the fourth passage 501, and the rotor chamber are sequentially connected, and the first passage 214, the second passage, the third passage 103, and the fourth passage 501 form a balancing passage. In this way, the large valve orifice 101 is connected to the rotor chamber, which is advantageous for achieving pressure balancing and avoiding or reducing the fluid pressure from interfering with the movement of the spindle member 200.

[0063] The valve seat portion 100 has a seat ring 104, the screw assembly 300 passes through the seat ring 104, and the third passage 103 is located in the seat ring 104, so that the seat ring 104 can have a guiding and restricting effect on the screw assembly 300 and prevent the flow of fluid from being obstructed by the presence of the seat ring 104. Here, the seat ring 104 includes a cylindrical structure and an annular structure, the annular structure is located on the outer circumferential surface of the cylindrical structure, the screw assembly 300 passes through the cylindrical structure, the cylindrical structure guides the screw assembly 300, and the third passage 103 passes through the annular structure.

[0064] Specifically, the nut assembly 500 includes a nut body 510 and a connecting plate 520. The connecting plate 520 is fitted into the nut body 510 and fixedly connected to the valve seat 100, with holes or open slots in the connecting plate 520 forming the fourth passage 501. This allows the connecting plate 520 to achieve a fixed connection between the nut assembly 500 and the valve seat 100 and prevent the connecting plate 520 from obstructing the flow of fluid. In addition, the valve seat ring 104 penetrates into the nut body 510, which is advantageous for ensuring the coaxiality between the nut body 510 and the screw assembly 300.

[0065] In this application, the valve seat 100 has a large gasket 110 that surrounds the large valve orifice 101. When the end of the large spindle 210 contacts the large gasket 110, the large valve orifice 101 is closed. The large gasket 110 is made of a soft material, which increases the contact area during sealing, ensuring reliable sealing and preventing leakage.

[0066] The valve seat portion 100 has an annular assembly groove, which surrounds the large valve port 101 and accommodates the large gasket 110. When the end of the large spindle portion 210 abuts against the large gasket 110, the large valve port 101 is closed. Here, the surface where the large gasket 110 and the large spindle portion 210 engage is the sealing surface 111, which is located at the opening of the annular assembly groove. The volume of the chamber of the annular assembly groove is greater than the volume of the large gasket 110 located in the annular assembly groove.

[0067] When this embodiment is adopted, the chamber volume of the annular assembly groove is larger than the volume of the large gasket 110 positioned in the annular assembly groove, so that the annular assembly groove can accommodate the deformation of the large gasket 110, ensuring that the sealing surface of the large gasket 110 is less likely to deform, thereby ensuring the sealing performance of the large gasket and improving the reliability of the electronic expansion valve for long-term use.

[0068] Furthermore, the sealing surface 111 is exposed from the annular assembly groove, and the remaining surfaces of the large gasket 110 are all located within the annular assembly groove. As a result, only the sealing surface 111 of the large gasket 110 that engages with the large spindle part 210 is exposed from the annular assembly groove, and the remaining surfaces of the large gasket 110 are all located within the annular assembly groove. As a result, the exposed surface of the large gasket 110 is very small and is less likely to deform when cooled or heated, which ensures the sealing performance of the large gasket 110 and improves the reliability of the electronic expansion valve during long-term use.

[0069] The surface where the large spindle part 210 and the sealing surface 111 engage is an arc-shaped surface, which increases the contact area and improves the sealing effect.

[0070] Here, at least one annular surface of the large gasket 110 located within the annular assembly groove and the inner wall of the annular assembly groove form an interference fit, thereby ensuring a sealing effect and preventing leakage from the electronic expansion valve. After the large gasket 110 is heated and expands, the outer circumferential surface of the large gasket 110 and the inner wall of the annular assembly groove are driven to form an interference fit, thereby enhancing the sealing effect. After the large gasket 110 is cooled and contracted, the inner circumferential surface of the large gasket 110 and the inner wall of the annular assembly groove are driven to form an interference fit, thereby enhancing the sealing effect.

[0071] In this embodiment, the gap between the outer wall of the large gasket 110 located in the annular assembly groove and the inner wall of the annular assembly groove forms at least one buffer chamber. The large gasket 110 is heated in a high-temperature working environment and undergoes thermal expansion. The buffer chamber accommodates the deformation of the large gasket 110, preventing the expansion from affecting the sealing effect. Here, the large gasket 110 is made of a soft material.

[0072] In this embodiment, the valve seat assembly 100 includes a large valve seat 120 and a small valve seat 130, the spindle member 200 is movably mounted within the large valve seat 120, the small valve seat 130 is connected to the large valve seat 120, the small valve seat 130 has a large valve port 101, and an annular assembly groove is formed between the small valve seat 130 and the large valve seat 120. This gives the valve seat assembly 100 a split structure, which facilitates the formation of the annular assembly groove and facilitates the assembly of the large gasket 110.

[0073] Specifically, the small valve seat 130 has a first annular step 131, the annular side wall of which is in restrictive engagement with the inner circumferential surface of the large gasket 110, and the bottom wall of the first annular step 131 is in restrictive engagement with the surface of the large gasket 110 on one side away from the large spindle portion 210. The first annular step 131 can provide a restricting and enclosing function for the large gasket 110 in the axial direction.

[0074] Here, the annular inner wall of the large valve seat 120 and the outer circumferential surface of the large gasket 110 are in restrictive engagement, thereby providing a restricting and enveloping effect on the large gasket 110 in the radial direction.

[0075] The annular inner wall of the large valve seat 120 is provided with a pressure ring 121, which is in restrictive engagement with one side of the large gasket 110 facing the large spindle portion 210. The pressure ring 121 provides a restrictive effect on the large gasket 110 in the axial direction and reduces the exposed surface area of ​​the large gasket 110. This makes the large gasket 110 less likely to deform when cooled or heated, ensuring the sealing performance of the large gasket 110.

[0076] In this embodiment, the large gasket 110 has a second annular step 112 that surrounds the sealing surface 111, with the end face of the pressure ring 121 and the bottom wall of the second annular step 112 being limitedly engaged, and the inner circumferential surface of the pressure ring 121 and the annular side wall of the second annular step 112 being limitedly engaged. The engagement between the second annular step 112 and the pressure ring 121 restricts the large gasket 110 in both the radial and axial directions, improving the fixing effect of the large gasket 110.

[0077] Here, the inner surface of the pressure ring 121 has a first chamfer 1211 at one end facing the bottom wall of the second annular step 112, and a first gap between the first chamfer 1211 and the large gasket 110. The inner surface of the large gasket 110 has a second chamfer 114 at one end away from the large spindle portion 210, and a second gap between the second chamfer 114 and the large gasket 110. The outer surface of the large gasket 110 has a third chamfer 115 at one end facing the large spindle portion 210, and a third gap between the third chamfer 115 and the large gasket 110. The first gap, second gap, and third gap are all buffer chambers.

[0078] On the one hand, providing chamfers is advantageous for assembling the large gasket 110, and on the other hand, since each chamfer forms a buffer chamber, it is possible to accommodate the deformation of the large gasket 110 when the large gasket 110 thermally expands, thereby preventing the sealing surface from becoming uneven due to expansion and preventing the expansion of the large gasket 110 from affecting the sealing effect.

[0079] In this embodiment, a portion of the small valve seat 130 penetrates into the large valve seat 120, and the small valve seat 130 and the large valve seat 120 may be welded together after interference fitting, ensuring high concentricity, a reliable connection, and good sealing performance through the interference fit. The large valve seat 120 has a plurality of through holes 102 distributed around its circumference, which connect the chambers within the large valve seat 120 and are used to transport fluid.

[0080] The flow hole 102 of the valve seat 100 may be used for connection to a connecting pipe or for communication with a chamber in another seat body structure. The large valve port 101 may be used for connection to a connecting pipe or for communication with a chamber in another seat body structure.

[0081] In another embodiment of the present application, the valve seat portion 100 has a large gasket 110 and a reinforcing sealing ring 140. The large gasket 110 is arranged to surround the large valve opening 101, and the reinforcing sealing ring 140 is arranged between the large gasket 110 and the inner wall of the valve seat portion 100. When the end of the large spindle portion 210 abuts against the large gasket 110, the large valve opening 101 is closed. The large gasket 110 increases the contact area during sealing, ensuring reliable sealing and preventing leakage. The reinforcing sealing ring 140 further improves the sealing effect.

[0082] The valve seat 100 has an annular assembly groove, and the surface where the large gasket 110 and the large spindle 210 engage is the sealing surface 111. The sealing surface 111 is exposed from the annular assembly groove, and the remaining surfaces of the large gasket 110 are all located within the annular assembly groove. This provides a reliable constraint for the large gasket 110, making it less likely to be deformed, damaged, or broken when pressure or temperature changes occur, and extending its service life.

[0083] The valve seat assembly 100 includes a large valve seat 120 and a small valve seat 130, the spindle member 200 is movably mounted within the large valve seat 120, the small valve seat 130 is fixedly connected to the large valve seat 120, the small valve seat 130 has a large valve opening 101, and an annular assembly groove is formed between the small valve seat 130 and the large valve seat 120, the large gasket 110 and the reinforcing sealing ring 140 are sandwiched within the annular assembly groove, and the reinforcing sealing ring 140 abuts against the inner wall of the annular assembly groove. This gives the valve seat assembly 100 a split structure, which facilitates the formation of the annular assembly groove and the assembly of the large gasket 110 and the reinforcing sealing ring 140.

[0084] Furthermore, the large gasket 110 has a third annular step 113 on one side away from the large spindle portion 210, and the reinforcing sealing ring 140 is mounted in the third annular step 113, and the reinforcing sealing ring 140 abuts against the large valve seat 120 and / or the small valve seat 130, and the third annular step 113 is used to accommodate the reinforcing sealing ring 140 and has a limiting effect on the reinforcing sealing ring 140.

[0085] The small valve seat 130 has a first annular step 131, the annular side wall of which is limitedly engaged with the inner peripheral surface of the large gasket 110, and the bottom wall of the first annular step 131 is limitedly engaged with the surface of the large gasket 110 on one side away from the large spindle portion 210, and the reinforcing sealing ring 140 abuts against the bottom wall of the first annular step 131. In this way, the first annular step 131 provides a reliable limit for the large gasket 110, and the engagement between the reinforcing sealing ring 140 and the first annular step 131 improves the sealing effect.

[0086] In this application, the large spindle part 210 includes a spindle body 240 and a small gasket 260 disposed within the spindle body 240. The small gasket 260 has a small valve port 211 and is made of a soft material, which increases the contact area between the small spindle 220 and the small gasket 260, improving the sealing effect and preventing leakage when the small valve port 211 is closed.

[0087] The spindle body 240 has an assembly groove 242, the opening of which faces the large valve opening 101, and the small gasket 260 is located in the assembly groove 242, which makes it easy to install the small gasket 260.

[0088] The bottom wall of the assembly groove 242 has an annular limiting surface against which the small gasket 260 abuts, thereby restricting the small gasket 260 in the axial direction.

[0089] Furthermore, the large spindle portion 210 further includes a restricting sleeve 270, and the small gasket 260 and the restricting sleeve 270 are both located within the spindle body 240, and the small gasket 260 is located at least partially between the spindle body 240 and the restricting sleeve 270, and the small gasket 260 has a small valve port 211, the spindle body 240 is used to open and close the large valve port 101, and the small spindle 220 is used to open and close the small valve port 211, and one end of the inner surface of the restricting sleeve 270 facing the large valve port 101 has a fillet or chamfer.

[0090] In this embodiment, the engagement between the small spindle 220 and the small gasket 260 ensures a reliable seal with respect to the small valve port 211, and the small gasket 260 is fixed by the limiting sleeve 270. The inner surface of the limiting sleeve 270 has a fillet or chamfer at one end facing the large valve port 101, which reduces resistance when the fluid passes through the fillet or chamfer and prevents the fluid from colliding and changing direction suddenly, thereby reducing noise when the fluid passes through the small valve port 211 and the limiting sleeve 270 and reducing the noise of the electronic expansion valve. Here, the limiting sleeve 270, the small gasket 260 and the small spindle 220 are arranged coaxially.

[0091] Here, the spindle body 240 has an assembly groove 242, the opening of which faces the large valve port 101, and the small gasket 260 is located in the assembly groove 242, which makes it easy to install the small gasket 260.

[0092] The bottom wall of the assembly groove 242 has an annular limiting surface against which the small gasket 260 abuts, thereby restricting the small gasket 260 in the axial direction.

[0093] Furthermore, at least a portion of the limiting sleeve 270 is positioned within the assembly groove 242, and the outer circumferential surface of the limiting sleeve 270 is interference-fit and / or welded to the inner circumferential surface of the assembly groove 242. This type of engagement method ensures a secure connection and high coaxiality.

[0094] The outer circumferential surface of the small gasket 260 has a chamfer at one end remote from the large valve opening 101. This makes it easier to assemble the small gasket 260 and press it into the recessed groove 242.

[0095] The spindle body 240 has an escape groove 243 at one end facing the large valve port 101, and the assembly groove 242 is located at the bottom wall of the escape groove 243. The valve seat 100 has a large gasket 110 surrounding the large valve port 101, with the edge of the opening of the escape groove 243 sealingly engaged with the end of the large gasket 110. The end face of the limiting sleeve 270 facing the large valve port 101 is flush with the bottom wall of the escape groove 243, or the end face of the limiting sleeve 270 facing the large valve port 101 protrudes from the bottom wall of the escape groove 243. The flushness of the end face of the limiting sleeve 270 with the bottom wall of the escape groove 243 avoids fluid resistance caused by uneven connection positions and makes it easy to limit the depth of insertion of the limiting sleeve 270 into the assembly groove 242, facilitating assembly. In addition, in this embodiment, when the inner wall of the assembly groove 242 and the limiting sleeve 270 are welded together, the welded portion is relatively far away from the end of the large spindle portion 210 (i.e., the sealed end for sealing), so that the welding heat is prevented from affecting the sealed end of the large spindle portion 210, and the sealed end of the large spindle portion 210 is prevented from being heated and deformed.

[0096] The small gasket 260 is made of a soft material, which provides a better sealing effect. The outer periphery of the small gasket 260 has a chamfer at one end away from the large valve opening 101, which makes it easier to insert the small gasket 260 into the assembled groove 242.

[0097] In this embodiment, the side wall of the valve seat 100 has a through hole 102, and the large spindle 210 has a side opening 212 and a flow chamber 215, one end of the side opening 212 communicates with the through hole 102 and the other end with the flow chamber 215, the small spindle 220 is at least partially located within the flow chamber 215, the small valve port 211 communicates with the flow chamber 215 when it is open, the end of the side opening 212 communicating with the flow chamber 215 is located in the middle of the side wall of the flow chamber 215, and there are multiple side openings 212, distributed circumferentially around the large spindle 210. The flow chamber 215 can communicate with one or more side openings 212. Here, the side openings 212 extend along the radial direction of the large spindle portion 210. Here, the diameter of each side opening 212 is smaller than the diameter of the flow chamber 215, so that the fluid can be buffered after entering the relatively large flow chamber 215 from the relatively small side openings 212.

[0098] One end of the side opening 212 that communicates with the flow chamber 215 is located in the middle of the side wall of the flow chamber 215, and burrs are likely to occur at the end of the side opening 212. However, by locating the one end of the side opening 212 that communicates with the flow chamber 215 in the middle of the side wall of the flow chamber 215, it becomes easier to remove burrs from the side opening 212 when processing the flow chamber 215.

[0099] In this embodiment, the spindle member 200 has a first passage 214, one end of which is connected to the large valve port 101 and the other end of which is connected to a chamber on one side of the large spindle part 210, away from the large valve port 101. This equalizes the fluid pressure intensity at both ends of the large spindle part 210, reducing the fluid pressure difference experienced by both ends of the large spindle part 210 and reducing the effect of fluid pressure on the opening and closing of the valve port, making operation easier.

[0100] Specifically, the valve seat 100 has an inner guide wall, a second inner sealing ring is provided between the large spindle 210 and the inner guide wall, the outer wall of the large spindle 210 is movably sealed and engaged with the inner guide wall by the second inner sealing ring, one end of the large spindle 210 facing the large valve port 101 is the sealing end, the valve seat 100 has a large gasket 110 surrounding the large valve port 101, and an annular sealing line is formed just where the sealing end contacts the large gasket 110, the diameter of the annular sealing line being equal to the outer diameter of the second inner sealing ring. This ensures that the contact areas of both axial ends of the large spindle 210 with the fluid are equal, and the fluid pressures experienced by both axial ends of the large spindle 210 are equal, achieving pressure balancing and making the valve port opening and closing smoother and more reliable.

[0101] In the present application, the spindle member 200 further includes a large elastic member 280, which is located within the chamber of the valve seat 100 and is located on one side of the large spindle member 210 away from the large valve orifice 101, with one end abutting the inner wall of the valve seat 100 and the other end abutting the large spindle member 210. The large elastic member 280 can apply a force toward the large valve orifice 101 to the large spindle member 210, thereby improving the closing effect of the large valve orifice 101 and preventing leakage due to poor closing of the valve orifice. Specifically, the large elastic member 280 is a spring, and is in a compressed state.

[0102] The valve seat portion 100 has a valve seat ring 104, and one end of the large elastic member 280 abuts against the valve seat ring 104, thereby restricting the axial direction of the large elastic member 280. Here, the valve seat ring 104 includes a tubular structure and an annular structure, the annular structure is located on the outer circumferential surface of the tubular structure, the screw assembly 300 passes through the tubular structure, and the tubular structure guides the screw assembly 300, and one end of the large elastic member 280 abuts against the annular structure.

[0103] The electronic expansion valve further includes a screw assembly 300, which is fixedly connected to the small spindle 220 so as to drive the small spindle 220 and the large spindle portion 210 to move back and forth. The screw assembly 300 penetrates the large elastic member 280, and the screw assembly 300 penetrates the valve seat ring 104, which can act as a guide and restriction for the screw assembly 300.

[0104] The large spindle section 210 includes a spindle body 240 and a limiting ring 250, the limiting ring 250 is fixed in a limiting hole 241 of the spindle body 240, the other end of the large elastic member 280 abuts against the limiting ring 250, a part of the large elastic member 280 is located in the limiting hole 241, the limiting hole 241 has the effect of restricting the large elastic member 280 in the radial direction, and the limiting ring 250 can withstand the pressure of the large elastic member 280, thereby transmitting the pressure to the spindle body 240.

[0105] The screw assembly 300 passes through the limit ring 250 and / or the small spindle 220 passes through the limit ring 250, and the small spindle 220 and the limit ring 250 are axially limitedly engaged with each other. The small spindle 220 can also be limited by the limit ring 250 to prevent the small spindle 220 and the spindle body 240 from separating.

[0106] In this application, the large spindle part 210 includes a spindle body 240 and a small gasket 260 disposed within the spindle body 240. The small gasket 260 has a small valve port 211. The small spindle 220 has a tapered segment 224 that is used to seal with the inner surface of the small valve port 211. This arrangement provides a large contact area between the tapered segment 224 and the small gasket 260, providing a good sealing effect for the small valve port 211. Furthermore, because the small spindle 220 has the tapered segment 224, the relative positions of the tapered segment 224 and the small valve port 211 can be adjusted to adjust the opening degree and flow rate of the small valve port 211, making it easy to achieve a flow rate curve that meets demand.

[0107] Here, the inner wall of the small valve orifice 211 has a chamfered segment 261, which is used for sealing engagement with the tapered segment 224, and the taper angle of the chamfered segment 261 is larger than the taper angle of the tapered segment 224. The engagement between the chamfered segment 261 and the tapered segment 224, on the one hand, improves the sealing effect when closing the small valve orifice 211, and on the other hand, makes it easier to achieve the required flow curve.

[0108] In addition, in this embodiment, it is easy to machine a tapered surface on the outer wall of the small spindle 220, and the tapered surface inside the small valve port 211 can be machined to be relatively short, and machining and detection are also easy, thereby reducing the difficulty of machining and detection and improving the production rate.

[0109] The spindle body 240 has a guide hole 213, and the small spindle 220 has a sealing segment 222 that passes through the guide hole 213 and is axially movable. The sealing segment 222 has a tapered segment 224, the diameter of the small end of which is smaller than the diameter of the equal-diameter segment of the sealing segment 222. The engagement between the guide hole 213 and the sealing segment 222 can guide the movement of the small spindle 220 and ensure the coaxiality of the small spindle 220 and the small valve orifice 211.

[0110] Here, the side wall of the valve seat portion 100 has a flow hole 102, and the spindle body 240 has a side opening 212, one end of which is connected to the flow hole 102, and when the small valve port 211 is opened, the small valve port 211 is connected to the other end of the side opening 212, and when the small valve port 211 or the large valve port 101 is opened, the large valve port 101 is connected to the flow hole 102, thereby realizing fluid flow.

[0111] In this embodiment, the spindle member 200 further includes a first inner sealing ring 231, the sealing segment 222 has a first inner sealing groove, the first inner sealing ring 231 is mounted in the first inner sealing groove, and the outer wall of the first inner sealing ring 231 abuts against the inner wall of the guide hole 213. The first inner sealing ring 231 can seal the gap between the inner wall of the guide hole 213 and the outer wall of the sealing segment 222 to avoid leakage.

[0112] Here, in the process of the small spindle 220 moving, if the frictional force between the first inner sealing ring 231 and the inner wall of the guide hole 213 is F1, and the resultant force of the fluid acting forces in the valve seat portion 100 received by the small spindle 220 is F2, then F1 < F2. That is, in this aspect, the acting force of the fluid on the small spindle 220 is always greater than the frictional force received by the small spindle 220. In this way, regardless of whether it is the valve opening process or the valve closing process, the resultant force of the frictional force and the fluid force received by the small spindle 220 is always in a predetermined direction, for example, upward or downward, and there is no change in the direction of the resultant force of the forces received during the movement of the small spindle 220. When the electronic expansion valve is assembled, an assembly gap inevitably exists in the axial direction of the small spindle 220. If a change occurs in the direction of the resultant force of the forces received during the movement of the small spindle 220, axial play (the play distance is the distance of the assembly gap) will occur in the small spindle 220, making the valve opening and closing unstable and affecting the accuracy of the flow rate curve. In this aspect, by limiting F1 < F2, the problem of axial play occurring in the small spindle 220 is avoided.

[0113] Here, the small spindle 220 further has a position limiting segment 221, which is located on one side of the guide hole 213 away from the large valve port 101 and is connected to the sealing segment 222, and the electronic expansion valve further includes a screw assembly 300 and a nut assembly 500, the screw assembly 300 and the nut assembly 500 are threadedly engaged with each other, and the screw assembly 300 is fixedly connected to the position limiting segment 221 so as to drive the small spindle 220 and the large spindle portion 210 to move back and forth. Here, there is a thread gap at the engagement position between the screw assembly 300 and the nut assembly 500, and when a change occurs in the resultant force as the small spindle 220 moves, the resultant force received by the small spindle 220 is transmitted to the engagement position, causing the small spindle 220 to move freely along the thread gap. However, by configuring it as described above, the resultant force received by the small spindle 220 is always unidirectional, and when transmitted to the engagement position, the screw assembly 300 and the nut assembly 500 are always abutting against each other in one direction at the engagement position. This prevents the screw assembly 300 from moving freely along the thread gap, thereby preventing the small spindle 220 from moving freely, thereby ensuring the stability of the small spindle 220 opening and closing the small valve port 211, and ensuring the consistency and stability of the flow curves for opening and closing the small valve port 211.

[0114] Specifically, the screw assembly 300 includes a screw 310, an assembly sleeve 320, a bearing 330, and a small elastic member 350. The screw 310 is connected to the inner ring of the bearing 330. The outer ring of the bearing 330 is located within the assembly sleeve 320. One end of the small elastic member 350 is restrictively engaged with the bearing 330, and the other end of the small elastic member 350 abuts against the position limiting segment 221. The small elastic member 350 applies a force towards the small valve port 211 to the small spindle 220. The assembly sleeve 320 is fixedly connected to the position limiting segment 221. The valve seat portion 100 has a valve seat ring 104. The assembly sleeve 320 reciprocates along the inner wall of the valve seat ring 104. The small elastic member 350 can improve the reliability of the small spindle 220 closing the small valve port 211 and can also play a buffering and protective role. The valve seat ring 104 can guide the reciprocating movement of the assembly sleeve 320.

[0115] Here, if the acting force of the small elastic member 350 on the small spindle 220 is F3, then F1 + F2 < F3. This avoids the small spindle 220 being pushed up by the acting force applied by the fluid to the small spindle 220 and ensures the reliability of closing the small valve port 211.

[0116] The spindle member 200 further includes a large elastic member 280. The large elastic member 280 is located within the chamber of the valve seat portion 100. The large elastic member 280 is located on one side away from the large valve port 101 of the large spindle portion 210. One end of the large elastic member 280 abuts against the inner wall of the valve seat portion 100, and the other end of the large elastic member 280 abuts against the large spindle portion 210. The large elastic member 280 is fitted outside the assembly sleeve 320. The large elastic member 280 applies an elastic force to the large spindle portion 210 to ensure the reliability of closing the large valve port 101. The above assembly method has a compact structure and avoids the volume of the electronic expansion valve becoming too large.

[0117] In the present application, the valve seat portion 100 includes a large valve seat 120 and a small valve seat 130, the spindle member 200 is movably arranged within the large valve seat 120, the small valve seat 130 is fixedly connected to the large valve seat 120, the small valve seat 130 has a large valve port 101, and a plurality of flow holes 102 are distributed around the large valve seat 120, and the flow holes 102 connect the chambers within the large valve seat 120.

[0118] The flow hole 102 of the valve seat 100 may be used for connection to a connecting pipe or for communication with a chamber in another seat body structure. The large valve port 101 may be used for connection to a connecting pipe or for communication with a chamber in another seat body structure.

[0119] The valve seat 100 further includes a first outer sealing ring 151, the outer wall of the large valve seat 120 has a first outer sealing groove, and the first outer sealing ring 151 is installed in the first outer sealing groove, thereby enabling the first outer sealing ring 151 to seal against the outer wall of the valve seat 100. The valve seat 100 further includes a second outer sealing ring 152, the outer wall of the small valve seat 130 has a second outer sealing groove, and the second outer sealing ring 152 is installed in the second outer sealing groove, and the flow hole 102 is located between the first outer sealing ring 151 and the second outer sealing ring 152, thereby enabling a good sealing effect when the valve seat 100 is connected to another seat body structure.

[0120] The large spindle portion 210 has a side opening 212 and a flow chamber 215, one end of the side opening 212 is connected to the flow hole 102 and the other end of the side opening 212 is connected to the flow chamber 215, the small spindle 220 passes through the flow chamber 215, and when the small valve port 211 is opened, the small valve port 211 is connected to the flow chamber 215, and the flow chamber 215 can be used to achieve communication with one or more side openings 212.

[0121] One end of the side opening 212 that communicates with the flow chamber 215 is located in the middle of the side wall of the flow chamber 215, and burrs are likely to form at the ends of the side opening 212, but by locating the one end of the side opening 212 that communicates with the flow chamber 215 in the middle of the side wall of the flow chamber 215, it becomes easier to remove burrs from the side opening 212 when processing the flow chamber 215. There are multiple side openings 212, and the multiple side openings 212 are distributed circumferentially around the large spindle portion 210, and the side openings 212 extend radially around the large spindle portion 210.

[0122] In this embodiment, the spindle member 200 has a first passage 214, one end of which is connected to the large valve port 101 and the other end of which is connected to a chamber on one side of the large spindle part 210, away from the large valve port 101. This makes the fluid pressure intensity at both ends of the large spindle part 210 equal, reducing the fluid pressure difference experienced by both ends of the large spindle part 210, reducing the effect of fluid pressure on the opening and closing of the valve port and facilitating operation.

[0123] Specifically, the valve seat 100 has an inner guide wall, the large spindle 210 moves back and forth along the inner guide wall, and the outer wall of the large spindle 210 is sealingly engaged with the inner guide wall, the end of the large spindle 210 facing the large valve port 101 is the sealing end, the valve seat 100 has a large gasket 110 that surrounds the large valve port 101, and as the sealing end moves toward the large valve port 101, an annular sealing line is formed just after the sealing end comes into contact with the large gasket 110, and the diameter of the annular sealing line is equal to the inner diameter of the inner guide wall. As a result, the contact areas between both axial ends of the large spindle 210 and the fluid are equal, and the fluid pressures experienced by both axial ends of the large spindle 210 are equal, realizing pressure balancing and making the valve port opening and closing smoother and more reliable.

[0124] Here, the spindle member 200 further includes a second inner sealing ring 232, and has a second inner sealing groove on the outer circumferential surface of the large spindle part 210. The second inner sealing ring 232 is mounted in the second inner sealing groove, and the outer wall of the second inner sealing ring 232 abuts against the inner wall of the valve seat part 100, thereby preventing internal leakage.

[0125] Here, the small spindle 220 and the large spindle portion 210 are axially limitedly engaged, and the electronic expansion valve further includes a screw assembly 300, which is fixedly connected to the small spindle 220 so as to drive the small spindle 220 and the large spindle portion 210 to move back and forth.

[0126] Specifically, the screw assembly 300 includes a screw 310, an assembly sleeve 320, a bearing 330, a bushing 340, and a small elastic member 350, the screw 310 is connected to the inner ring of the bearing 330, the outer ring of the bearing 330 is located within the assembly sleeve 320 and is limitedly engaged with the assembly sleeve 320, the bushing 340 is abutted against one side of the outer ring of the bearing 330 toward the large valve port 101, the small elastic member 350 is fitted into the bushing 340, one end of the small elastic member 350 away from the bearing 330 is abutted against the small spindle 220, and the assembly sleeve 320 is fixedly connected to the small spindle 220. The small elastic member 350 can apply a preload force to the small spindle 220 toward the small valve port 211, thereby ensuring that the small valve port 211 is closed reliably and preventing leakage. The small elastic member 350 also has a buffering effect, preventing the axial displacement of the screw 310 from becoming too large and damaging the structure.

[0127] Here, the bushing 340 has a through hole, and the through hole of the bushing 340 avoids the inner ring of the bearing 330 and the end of the screw 310; or the bushing 340 has a groove, the opening of the groove of the bushing 340 faces the screw 310, and the groove of the bushing 340 avoids the inner ring of the bearing 330 and the end of the screw 310; and one end of the bushing 340 facing the large valve port 101 has a solid structure. By making the end of the bushing 340 facing the large valve port 101 a solid structure, impurities can be prevented from entering the bearing 330, and the service life of the bearing 330 can be improved.

[0128] Here, the assembly sleeve 320 includes an assembly tube and an annular stop wall, the annular stop wall is located at one end of the assembly tube away from the large valve opening 101, a portion of the small spindle 220 penetrates into the assembly tube and is fixedly connected to the assembly tube, and the outer ring of the bearing 330 abuts against the annular stop wall, thereby realizing the fixing and installation of the bearing 330.

[0129] The above-mentioned are only preferred embodiments of the present invention, and are not intended to limit the present invention. Those skilled in the art can make various modifications and changes to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. a valve seat (100) having a valve chamber; a spindle member (200) provided in a valve chamber of the valve seat portion (100), the spindle member (200) including a large spindle portion (210) and a small spindle (220), the large spindle portion (210) including a spindle body (240), the spindle body (240) having a small valve port (211), the small spindle (220) being used to close the small valve port (211); The spindle body (240) has a guide hole (213), and a first inner sealing ring (231) is provided between the small spindle (220) and the inner wall of the guide hole (213). The small spindle (220) is movably sealed and engaged with the inner wall of the guide hole (213) through the first inner sealing ring (231). A sealing portion (105) is formed at the position where the small spindle (220) and the small valve port (211) abut. A valve chamber at one end of the small spindle (220) remote from the sealing portion (105) is connected to the small valve port (211). wherein the first inner sealing ring (231) is located in a first inner sealing groove on the outer wall of the small spindle (220), and the maximum diameter of the sealing portion (105) is smaller than the outer diameter of the first inner sealing ring (231); or the first inner sealing ring (231) is located in a first inner sealing groove on the inner wall of the guide hole (213), and the maximum diameter of the sealing portion (105) is smaller than the inner diameter of the first inner sealing ring (231).

2. When the first inner sealing ring (231) is located in the first inner sealing groove on the inner wall of the guide hole (213), the friction force between the first inner sealing ring (231) and the outer wall of the small spindle (220) is F1, and the resultant force of the acting force of the fluid in the valve seat portion (100) that the small spindle (220) receives is F2, and F1<F2; 2. The electronic expansion valve according to claim 1, wherein when the first inner sealing ring (231) is located in the first inner sealing groove on the outer wall of the small spindle (220), the friction force between the first inner sealing ring (231) and the inner wall of the guide hole (213) is F1, and the resultant force of the acting force of the fluid in the valve seat portion (100) that the small spindle (220) receives is F2, and F1<F2.

3. 3. The electronic expansion valve according to claim 2, further comprising a screw assembly (300), wherein the screw assembly (300) comprises a small elastic member (350), one end of which abuts against the small spindle (220), and when the small valve port (211) is closed, the force applied by the small elastic member (350) to the small spindle (220) toward the small valve port (211) is a sealing preload, and where F3 is the minimum value of the sealing preload, F1 + F2 < F3.

4. 2. The electronic expansion valve according to claim 1, wherein the small spindle (220) has a sealing segment (222), the sealing segment (222) axially movably passing through the guide hole (213), the sealing segment (222) has a first inner sealing groove, the first inner sealing ring (231) is mounted in the first inner sealing groove, and the outer wall of the first inner sealing ring (231) abuts against the inner wall of the guide hole (213).

5. 2. The electronic expansion valve according to claim 1, wherein the small spindle (220) has a tapered segment (224), and the sealing portion (105) is formed at a position where the tapered segment (224) and the small valve port (211) abut against each other.

6. 2. The electronic expansion valve according to claim 1, wherein the large spindle portion (210) further includes a small gasket (260) provided in the spindle body (240), the small valve port (211) includes a through hole in the small gasket (260), an inner wall of the through hole and a tapered segment (224) of the small spindle (220) are sealingly engaged with each other, and one end of the through hole facing the first inner sealing ring (231) has a chamfered surface.

7. 5. The electronic expansion valve according to claim 4, wherein the small spindle (220) further comprises a position limiting segment (221), the position limiting segment (221) being located on one side of the guide hole (213) away from the small valve port (211) and connected to the sealing segment (222), and the valve chamber in which the position limiting segment (221) is located is connected to the small valve port (211).

8. 5. The electronic expansion valve according to claim 4, wherein the valve seat portion (100) has a large valve port (101), the spindle body (240) is used to close the large valve port (101), the spindle body (240) is provided with a balancing passage, a valve chamber at one end of the spindle body (240) remote from the large valve port (101) is connected to the large valve port (101) through the balancing passage, a valve chamber at one end of the small spindle (220) remote from the sealing portion (105) is connected to the small valve port (211) through the balancing passage, and the large valve port (101) is connected to the small valve port (211).

9. 2. The electronic expansion valve of claim 1, wherein the large spindle portion further includes a limiting ring fixed within the spindle body, the small spindle penetrates the spindle body, and the limiting ring and the small spindle are engaged to prevent the small spindle and the large spindle portion from separating.

10. 10. The electronic expansion valve of claim 9, wherein the spindle body (240) further has a restrictive hole (241), the inner diameter of the guide hole (213) is smaller than the inner diameter of the restrictive hole (241), the restrictive ring (250) is fixed in the restrictive hole (241), and one end of the small spindle (220) away from the sealing portion (105) is located in the restrictive hole (241).

11. 2. The electronic expansion valve according to claim 1, wherein the valve seat portion (100) has a large valve port (101), an annular assembly groove, and a large gasket (110), the annular assembly groove surrounds the large valve port (101) and accommodates the large gasket (110), and when an end of the large spindle portion (210) abuts against the large gasket (110), the large valve port (101) is closed, and a surface where the large gasket (110) and the large spindle portion (210) engage is a sealing surface (111), the sealing surface (111) is located at the opening of the annular assembly groove, and a volume of a chamber of the annular assembly groove is greater than a volume of the large gasket (110) located in the annular assembly groove.

12. The electronic expansion valve according to claim 11, wherein at least one annular surface of the large gasket (110) located within the annular assembly groove and an inner wall of the annular assembly groove are interference-fitted.

13. 12. The electronic expansion valve according to claim 11, wherein a gap between an outer wall of the large gasket (110) located in the annular assembly groove and an inner wall of the annular assembly groove forms at least one buffer chamber.

14. 12. The electronic expansion valve according to claim 11, wherein the valve seat portion (100) includes a large valve seat (120) and a small valve seat (130), the spindle member (200) is movably disposed within the large valve seat (120), the small valve seat (130) is connected to the large valve seat (120), the small valve seat (130) has the large valve port (101), and the annular assembly groove is formed between the small valve seat (130) and the large valve seat (120).

15. 15. The electronic expansion valve according to claim 14, wherein the small valve seat (130) has a first annular step (131), an annular side wall of the first annular step (131) and an inner circumferential surface of the large gasket (110) are in restrictive engagement with each other, and a bottom wall of the first annular step (131) and a surface of the large gasket (110) on one side away from the large spindle portion (210) are in restrictive engagement with each other.

16. 15. The electronic expansion valve according to claim 14, wherein the annular inner wall of the large valve seat (120) has a pressure ring (121), and the pressure ring (121) and one side of the large gasket (110) facing the large spindle portion (210) are in limited engagement with each other.

17. 17. The electronic expansion valve according to claim 16, wherein the large gasket (110) has a second annular step (112), the second annular step (112) is arranged to surround the sealing surface (111), an end face of the pressure ring (121) and a bottom wall of the second annular step (112) are in restrictive engagement, and an inner peripheral surface of the pressure ring (121) and an annular side wall of the second annular step (112) are in restrictive engagement.

18. 18. The electronic expansion valve of claim 17, wherein the inner circumferential surface of the pressure ring has a first chamfer (1211) at one end facing the bottom wall of the second annular step (112), with a first gap between the first chamfer (1211) and the large gasket (110); the inner circumferential surface of the large gasket has a second chamfer (114) at one end facing away from the large spindle portion (210), with a second gap between the second chamfer (114) and the large gasket (110); the outer circumferential surface of the large gasket has a third chamfer (115) at one end facing the large spindle portion (210), with a third gap between the third chamfer (115) and the large gasket (110); and the first gap, the second gap, and the third gap are all buffer chambers.

19. 12. The electronic expansion valve according to claim 11, wherein the valve seat portion (100) further comprises a reinforcing sealing ring (140), the large gasket (110) is disposed surrounding the large valve port (101), and the reinforcing sealing ring (140) is disposed between the large gasket (110) and an inner wall of the annular assembly groove.

20. The valve seat portion (100) includes a large valve seat (120) and a small valve seat (130), the spindle member (200) is movably disposed within the large valve seat (120), the small valve seat (130) is connected to the large valve seat (120), the small valve seat (130) has the large valve port (101), and the annular assembly groove is formed between the small valve seat (130) and the large valve seat (120).

20. The electronic expansion valve according to claim 19, wherein the large gasket (110) has a third annular step (113) on one side away from the large spindle portion (210), the reinforcing sealing ring (140) is mounted within the third annular step (113), and the reinforcing sealing ring (140) abuts against the large valve seat (120) and / or the small valve seat (130).

21. 2. The electronic expansion valve according to claim 1, wherein the valve seat portion (100) has a large valve port (101), the large spindle portion (210) further includes a small gasket (260) and a limiting sleeve (270), the small gasket (260) and the limiting sleeve (270) are both located within the spindle body (240), at least a portion of the small gasket (260) is located between the spindle body (240) and the limiting sleeve (270), the small gasket (260) has the small valve port (211), the spindle body (240) is used to open and close the large valve port (101), and one end of the inner circumferential surface of the limiting sleeve (270) facing the large valve port (101) has a fillet or chamfer.

22. 22. The electronic expansion valve according to claim 21, wherein the spindle body (240) has an assembly groove (242), the opening of the assembly groove (242) faces the large valve port (101), and the small gasket (260) is located in the assembly groove (242).

23. The electronic expansion valve according to claim 22, wherein at least a portion of the limiting sleeve (270) is positioned within the assembly groove (242), and the outer peripheral surface of the limiting sleeve (270) and the inner peripheral surface of the assembly groove (242) are interference-fitted and / or welded.

24. 24. The electronic expansion valve according to claim 23, wherein the outer circumferential surface of the limiting sleeve (270) has a chamfer at one end facing the small gasket (260).

25. 24. The electronic expansion valve according to claim 23, wherein the spindle body (240) has an escape groove (243) at one end toward the large valve port (101), the assembly groove (242) is located on the bottom wall of the escape groove (243), the valve seat portion (100) has a large gasket (110) surrounding the large valve port (101), and the edge of the opening of the escape groove (243) and the end of the large gasket (110) are sealingly engaged.

26. 26. The electronic expansion valve according to claim 25, wherein the end face of the limiting sleeve (270) facing the large valve port (101) is flush with the bottom wall of the avoidance groove (243), or the end face of the limiting sleeve (270) facing the large valve port (101) protrudes from the bottom wall of the avoidance groove (243).

27. 23. The electronic expansion valve according to claim 22, wherein the small gasket (260) is made of a soft material and has a chamfer at one end of the outer circumferential surface of the small gasket (260) remote from the large valve port (101).

28. The side wall of the valve seat portion (100) has a flow hole (102), the large spindle portion (210) has a side opening (212) and a flow chamber (215), one end of the side opening (212) is connected to the flow hole (102) and the other end of the side opening (212) is connected to the flow chamber (215), the small spindle (220) is at least partially located within the flow chamber (215), and when the small valve port (211) is opened, the small valve port (211) is opened.

22. The electronic expansion valve according to claim 21, wherein the side opening (211) is connected to the flow chamber (215), one end of the side opening (212) connected to the flow chamber (215) is located in the middle of the side wall of the flow chamber (215), the side openings (212) are multiple, the multiple side openings (212) are distributed in the circumferential direction of the large spindle portion (210), and the hole diameters of each of the side openings (212) are smaller than the hole diameter of the flow chamber (215).

29. 22. The electronic expansion valve according to claim 21, wherein the valve seat portion (100) has a guide inner wall, a second inner sealing ring is provided between the large spindle portion (210) and the guide inner wall, an outer wall of the large spindle portion (210) is movably sealingly engaged with the guide inner wall via the second inner sealing ring, one end of the large spindle portion (210) facing the large valve port (101) is a sealing end, the valve seat portion (100) has a large gasket (110) surrounding the large valve port (101), an annular sealing line is formed at a position immediately after the sealing end and the large gasket (110) come into contact, and a diameter of the annular sealing line is equal to an outer diameter of the second inner sealing ring.

30. 7. The electronic expansion valve according to claim 6, wherein the spindle body (240) has a guide hole (213), the small spindle (220) has a sealing segment (222) that axially movably passes through the guide hole (213), the sealing segment (222) has the tapered segment (224), and the diameter of the small end of the tapered segment (224) is smaller than the diameter of the constant diameter segment of the sealing segment (222).

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