Electronic expansion valve

Abstract

The electronic expansion valve comprises a valve seat assembly, a valve element assembly and a guide structure. The valve seat assembly is provided with a valve cavity, and the cavity wall of the valve cavity is provided with a valve port. A backpressure cavity is formed in the top of the valve cavity; the valve element assembly is at least partially arranged in the valve cavity, can move in the axial direction of the electronic expansion valve and is used for blocking or opening the valve port. A first balance channel communicated with the back pressure cavity and the valve port is formed in the valve element assembly; the guiding structure is used for guiding the valve element assembly to move. The guide structure is provided with a second balance channel communicated with the first balance channel and the valve port.

Description

Technical Field

[0001] This application relates to the technical field of valves, and more particularly, to an electronic expansion valve. Background Art

[0002] An electronic expansion valve is a device used to control the refrigerant flow rate in a refrigeration cycle, and is commonly used in refrigeration and air conditioning systems. It is an expansion valve that adjusts the refrigerant flow rate through an electronic control method to ensure the normal operation and high efficiency of the refrigeration system.

[0003] The electronic expansion valve includes a valve core assembly and a valve seat assembly. The valve seat assembly has a valve port. The valve core assembly is movably disposed within the valve seat assembly for blocking or opening the valve port or adjusting the opening degree of the valve port. However, due to the large fluid impact force of the refrigerant, the valve core assembly is prone to tilting after being impacted by the refrigerant and cannot be aligned with the valve port, reducing the working reliability of the electronic expansion valve. Summary of the Utility Model

[0004] Embodiments of this application provide an electronic expansion valve to improve the problem that the valve core assembly is prone to tilting after being impacted by the refrigerant.

[0005] The electronic expansion valve according to the embodiments of this application includes:

[0006] A valve seat assembly having a valve cavity, the cavity wall of the valve cavity having a valve port; the top of the valve cavity having a back pressure cavity;

[0007] A valve core assembly, at least a part of the valve core assembly being disposed within the valve cavity and axially movable along the electronic expansion valve for blocking or opening the valve port; the valve core assembly having a first balance channel communicating with the back pressure cavity and the valve port; and

[0008] A guiding structure for guiding the movement of the valve core assembly relative to the valve seat assembly; the guiding structure having a second balance channel communicating with the first balance channel and the valve port.

[0009] According to some embodiments of this application, the guiding structure includes:

[0010] A connecting portion connected to the cavity wall of the valve cavity and having the second balance channel; and

[0011] A guiding portion connected to one of the connecting portion and the valve core assembly and guidingly cooperating with the other.

[0012] According to some embodiments of this application, the guiding portion is a guiding hole that axially penetrates the connecting portion along the electronic expansion valve;

[0013] The spool assembly is disposed through the guiding hole, and the outer peripheral surface of the spool assembly is in guiding cooperation with the hole wall of the guiding hole.

[0014] According to some embodiments of the present application, the guiding portion includes a first guiding rod and a guiding column. One end of the first guiding rod is connected to the connecting portion, and the other end is connected to the guiding column. The guiding column extends into the first balance channel, and the outer peripheral surface of the guiding column is in guiding cooperation with the inner wall surface of the first balance channel.

[0015] Alternatively, the guiding portion includes a first guiding rod and a guiding column. One end of the guiding column extends into the first balance channel and is connected to the spool assembly, and the other end is connected to the first guiding rod. The connecting portion further has a guiding hole axially penetrating therethrough, and the outer peripheral surface of the first guiding rod is in guiding cooperation with the hole wall of the guiding hole.

[0016] According to some embodiments of the present application, the outer periphery of the guiding column has a first cutting surface. The first cutting surface penetrates through two first end faces of the guiding column, and the first cutting surface and the inner wall surface of the first balance channel enclose a third balance channel. The first balance channel is communicated with the valve port through the third balance channel.

[0017] According to some embodiments of the present application, the guiding portion includes a second guiding rod. One end is connected to the connecting portion, and the other end extends into the first balance channel. The outer peripheral surface of the second guiding rod is in guiding cooperation with the inner wall surface of the first balance channel.

[0018] Alternatively, the guiding portion includes a second guiding rod. The connecting portion further has a guiding hole axially penetrating therethrough. One end of the second guiding rod extends into the first balance channel and is connected to the spool assembly, and the other end is in guiding cooperation with the hole wall of the guiding hole.

[0019] According to some embodiments of the present application, the outer periphery of the second guiding rod has a second cutting surface. One end of the second cutting surface extends to the second end face of the second guiding rod located in the first balance channel.

[0020] The second cutting surface and the inner wall surface of the first balance channel enclose a fourth balance channel. The first balance channel is communicated with the valve port through the fourth balance channel.

[0021] According to some embodiments of the present application, the number of the second cutting surfaces is multiple and is arranged along the circumferential direction of the second guiding rod.

[0022] According to some embodiments of the present application, the second guiding rod internally has a fifth balance channel. The fifth balance channel penetrates through two second end faces of the second guiding rod.

[0023] The first balance channel communicates with the second balance channel through the fifth balance channel.

[0024] According to some embodiments of the present application, the connecting portion has a plurality of the second balance channels, and the plurality of the second balance channels are arranged along the circumferential direction of the guiding portion.

[0025] One embodiment of the above application has at least the following advantages or beneficial effects:

[0026] The electronic expansion valve of the embodiment of the present application includes a guiding structure for guiding the movement of the valve core assembly. The guiding structure ensures the stability of the valve core assembly during the movement process, and can effectively avoid the problem that the valve core assembly is prone to tilt and cannot align with the valve port after being affected by the fluid impact force. In addition, the valve core assembly has a first balance channel communicating with the back pressure chamber and the valve port, and the guiding structure has a second balance channel communicating with the first balance channel and the valve port, so that the electronic expansion valve is an internal balance valve as a whole, improving the ability to open and close the valve. Description of the Drawings

[0027] Figure 1 The side view schematic diagram of the electronic expansion valve according to the first embodiment of the present application is shown.

[0028] Figure 2 The three-dimensional schematic diagram of the electronic expansion valve according to the first embodiment of the present application is shown.

[0029] Figure 3 Shown is along Figure 1 The cross-sectional view taken along the A-A cutting line.

[0030] Figure 4 The schematic diagram when the first valve core and the second valve core are not installed in place is shown.

[0031] Figure 5 Shown is Figure 4 The exploded schematic diagram.

[0032] Figure 6 Shown is along Figure 4 The cross-sectional view taken along the B-B cutting line.

[0033] Figure 7 The cross-sectional view of the electronic expansion valve according to the second embodiment of the present application is shown.

[0034] Figure 8 Shown is Figure 7 The three-dimensional schematic diagram of the guiding portion in

[0035] Figure 9 The cross-sectional view of the electronic expansion valve according to the third embodiment of the present application is shown.

[0036] Figure 10 Shown isFigure 9 Schematic perspective view of the second guide rod in

[0037] Figure 11 The figure shows a cross-sectional view of the electronic expansion valve according to the fourth embodiment of the present application.

[0038] Figure 12 The figure shows Figure 11 Schematic perspective view of the second guide rod in

[0039] Figure 13 The figure shows a cross-sectional view of the electronic expansion valve according to the fifth embodiment of the present application.

[0040] Figure 14 The figure shows a cross-sectional view of the electronic expansion valve according to the sixth embodiment of the present application.

[0041] Figure 15 The figure shows a cross-sectional view of the electronic expansion valve according to the seventh embodiment of the present application. Detailed implementation manners

[0042] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures and thus their detailed description will be omitted.

[0043] It will be understood that the terms "comprise" and "have" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that comprises a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or components inherent to these processes, methods, products or devices.

[0044] As Figures 1 to 3 shown, the electronic expansion valve according to the first embodiment of the present application includes a valve seat assembly 100, a valve core assembly 200, a rotor assembly 810, an outer cover 820, a nut seat 830, and a screw 300.

[0045] The valve seat assembly 100 has a valve cavity 110. At least part of the valve core assembly 200 is disposed in the valve cavity 110 and is axially movable relative to the valve seat assembly 100 along the electronic expansion valve. The outer cover 820 is fixedly connected to the valve seat assembly 100, for example, by welding, but not limited thereto. The rotor assembly 810 is movably disposed in the outer cover 820 and is used to be coupled to a coil assembly (not shown in the figure) sleeved on the outer periphery of the outer cover 820. The nut seat 830 is fixedly connected to the valve seat assembly 100 and is disposed in the outer cover 820. The screw rod 300 is disposed in the outer cover 820, is connected to the rotor assembly 810, and is screwed to the nut seat 830.

[0046] When the electronic expansion valve works, by applying a pulse signal to the coil assembly, the rotor assembly 810 can be driven to drive the screw rod 300 to rotate. Since the nut seat 830 is fixed and screwed to the screw rod 300, the screw rod 300 can reciprocate axially along the electronic expansion valve, thereby driving the valve core assembly 200 to move in the valve cavity 110 relative to the valve seat assembly 100.

[0047] The valve seat assembly 100 may include a first valve seat 120, a second valve seat 130, and a third valve seat 150. Along the axis of the electronic expansion valve, the first valve seat 120, the second valve seat 130, and the third valve seat 150 are connected in sequence and jointly enclose the valve cavity 110.

[0048] The valve seat assembly 100 has a first opening 103, a second opening 104, and a third opening 105 that communicate with the valve cavity 110. The first opening 103, the second opening 104, and the third opening 105 are arranged in sequence along the axis of the electronic expansion valve. The cavity wall of the valve cavity 110 has a valve port 110a. It can be understood that the number of the valve ports 110a can be one or more. When the number of the valve ports 110a is two, the two valve ports 110a are respectively defined as a first valve port 101 and a second valve port 102. Among them, the first valve port 101 is located between the second opening 104 and the third opening 105, and the second valve port 102 is located between the second opening 104 and the first opening 103.

[0049] In the embodiment of the present application, the second valve seat 130 has the first opening 103, the second opening 104, and the second valve port 102, and the third valve seat 150 has the third opening 105 and the first valve port 101, but not limited thereto.

[0050] As Figures 3 to 6As shown, the valve core assembly 200 includes a first valve core 210, a second valve core 220, and a first elastic member 230. The first valve core 210 is movable between a first position blocking the first valve port 101 and a second position blocking the second valve port 102. The second valve core 220 is used to drive the first valve core 210 to move. The first elastic member 230 is connected between the first valve core 210 and the second valve core 220. After the first valve core 210 is in the first position, the second valve core 220 can move relative to the first valve core 210 in a direction closer to the first valve port 101, so that the compression amount of the first elastic member 230 increases and is used to apply a first pre-tightening force for blocking the first valve port 101 to the first valve core 210. The screw 300 is used to drive the second valve core 220 to move along the axial direction of the electronic expansion valve.

[0051] The electronic expansion valve further includes a second elastic member 500. The second elastic member 500 is connected between the second valve core 220 and the screw 300. After the first valve core 210 is in the second position, the screw can move relative to the first valve core 210 in a direction away from the second valve port 102, so that the compression amount of the second elastic member 500 increases and is used to apply a second pre-tightening force for blocking the second valve port 102 to the first valve core 210 through the second valve core 220.

[0052] The electronic expansion valve according to the embodiment of the present application includes a first elastic member 230 and a second elastic member 500. The first elastic member 230 can apply a first pre-tightening force for blocking the first valve port 101 to the first valve core 210, and the second elastic member 500 can apply a second pre-tightening force for blocking the second valve port 102 to the first valve core 210. In this way, the sealing performance of the first valve core 210 blocking the first valve port 101 or the second valve port 102 is significantly improved, preventing fluid leakage of the electronic expansion valve and improving the working reliability. In addition, in the electronic expansion valve according to the embodiment of the present application, the screw 300 drives the first valve core 210 to move between the first position and the second position through the second valve core 220. Moreover, the first pre-tightening force provided by the first elastic member 230 acts on the first valve core 210 and the second valve core 220 respectively, and the second pre-tightening force provided by the second elastic member 500 acts on the screw 300 and the second valve core 220 respectively, so that the first pre-tightening force and the second pre-tightening force do not affect each other, ensuring that the first pre-tightening force and the second pre-tightening force are large enough, and further improving the sealing performance when the first valve core 210 blocks the first valve port 101 and the second valve port 102.

[0053] In one embodiment, the first elastic member 230 and the second elastic member 500 can be compression springs, but not limited thereto. For example, the first elastic member 230 and the second elastic member 500 can also be rubber parts or other components that can provide elastic force when compressed.

[0054] Such as Figure 3 、 Figure 5 and Figure 6As shown, the first valve core 210 includes a first component and a second component, and the first component and the second component are connected by interference fit. In the embodiment of the present application, the first component is the valve needle 211, and the second component is the first valve sleeve 212. The valve needle 211 is used to block the first valve port 101 or the second valve port 102. At least part of the first valve sleeve 212 is sleeved on the outer periphery of the valve needle 211 and is fixedly connected to the valve needle 211; wherein, the first valve sleeve 212 is connected to the second valve core 220 in a limiting manner so that the first valve core 210 moves from the first position to the second position.

[0055] One end face 2111 is provided on the part of the valve needle 211 surrounded by the first valve sleeve 212. A first stop portion 2121 is convexly provided on the inner peripheral surface of the first valve sleeve 212, and the first stop portion 2121 and the end face 2111 are arranged at intervals along the axial direction of the electronic expansion valve. A flange 2211 is provided on the part of the second valve core 220 extending into the first valve sleeve 212, and the flange 2211 can move between the first stop portion 2121 and the end face 2111 to compress the first elastic member 230; the flange 2211 can also pull the first stop portion 2121 so that the first valve core 210 moves from the first position to the second position.

[0056] The second valve core 220 includes a valve core seat 221 and a second valve sleeve 222. One axial end of the second valve sleeve 222 is fixedly connected to the valve core seat 221, such as by welding, screwing, interference fit, etc. At least part of the valve core seat 221 is arranged inside the first valve core 210 and is used to pull the first valve core 210 to move from the first position to the second position, or to compress the first elastic member 230. One end of the second elastic member 500 and one end of the screw 300 are arranged inside the second valve sleeve 222. Wherein, the valve core seat 221 has a flange 2211, and the flange 2211 can move between the first stop portion 2121 and the end face 2111. When the flange 2211 moves in the direction close to the first valve port 101, it can compress the first elastic member 230. When the flange 2211 moves in the direction away from the first valve port 101, it can pull the first stop portion 2121 so that the first valve core 210 moves from the first position to the second position.

[0057] A second stop portion 2221 is provided on the inner peripheral surface of the second valve sleeve 222. The screw 300 includes a rod portion 310 and a third stop portion 320. The rod portion 310 is screwed to the nut seat 830, and the third stop portion 320 is connected to one end of the rod portion 310 and is located inside the second valve sleeve 222 and can move between the second stop portion 2221 and the valve core seat 221; one end of the second elastic member 500 abuts against the second stop portion 2221, and the other end abuts against the third stop portion 320.

[0058] As Figure 3 and Figure 6As shown in the figure, the third stopper 320 includes a bearing 321 and a protective sheet 322. The inner ring of the bearing 321 is sleeved on the outer periphery of the rod portion 310 and is fixedly connected to the rod portion 310; the protective sheet 322 is disposed on the side of the bearing 321 facing the second stopper 2221, and the other end of the second elastic member 500 abuts against the protective sheet 322.

[0059] In the embodiment of the present application, the protective sheet 322 can play a role in protecting the bearing 321, preventing the second elastic member 500 from directly abutting against the bearing 321 and causing deformation of the bearing 321.

[0060] The valve needle 211 has a receiving groove 2112, and the receiving groove 2112 is recessed from the end face 2111 along the axial direction of the electronic expansion valve away from the second valve core 220; the first elastic member 230 is accommodated in the receiving groove 2112, one end of the first elastic member 230 abuts against the bottom surface of the receiving groove 2112, and the other end abuts against the second valve core 220.

[0061] In the embodiment of the present application, the receiving groove 2112 can play a role in limiting the first elastic member 230, preventing the elastic pre-tightening force provided by the first elastic member 230 from being affected due to the change in the position of the first elastic member 230.

[0062] In an embodiment, the valve needle 211 is in interference fit with the first valve sleeve 212. For example, the portion of the valve needle 211 surrounded by the first valve sleeve 212 has a first fitting section 2113 and a second fitting section 2114. The first fitting section 2113 and the second fitting section 2114 are arranged along the axial direction of the electronic expansion valve, and the first fitting section 2113 is closer to the second valve core 220 than the second fitting section 2114; the first fitting section 2113 is in clearance fit with the inner peripheral surface of the first valve sleeve 212, and the second fitting section 2114 is in interference fit with the inner peripheral surface of the first valve sleeve 212.

[0063] Of course, in other embodiments, the valve needle 211 and the first valve sleeve 212 can also be connected by welding, screwing, etc.

[0064] The following combines Figure 3 to describe in detail the movement process of the valve core assembly 200, and how the first elastic member 230 and the second elastic member 500 provide elastic pre-tightening force.

[0065] The process of the first spool 210 blocking the first valve port 101: The rotor assembly 810 drives the screw 300 to rotate. Under the screw-thread fit between the screw 300 and the nut seat 830, the whole screw 300 moves downward. During the downward movement of the screw 300, the bearing 321 of the screw 300 presses against the spool seat 221, causing the valve needle 211 to move in the direction of blocking the first valve port 101. When the valve needle 211 blocks the first valve port 101 (the first position), the valve needle 211 stops moving further. At this time, the spool seat 221 continues to move downward, and the compression amount of the first elastic member 230 increases under the extrusion of the spool seat 221 and provides a first pre-tightening force. Under the action of the first pre-tightening force, the valve needle 211 can tightly block the first valve port 101, improving the sealing performance of the valve needle 211 blocking the first valve port 101.

[0066] The process of the first spool 210 blocking the second valve port 102: The rotor assembly 810 drives the screw 300 to rotate in the reverse direction. Under the screw-thread fit between the screw 300 and the nut seat 830, the screw 300 drives the second spool 220 to move upward through the second elastic member 500. During the upward movement of the second spool 220, the flange 2211 contacts the first stop portion 2121 of the first valve sleeve 212. Then, the second spool 220 can drive the first spool 210 to move to the second position. When the first spool 210 moves to the second position, the first spool 210 cannot move upward further. Under the action of the first stop portion 2121 blocking the flange 2211, the second spool 220 also cannot move upward further. At this time, the screw 300 can continue to move upward under the drive of the rotor assembly 810. During the continuous movement of the screw 300, the third stop portion 320 of the screw 300 presses against the second elastic member 500, causing the compression amount of the second elastic member 500 to increase and generating a second pre-tightening force. The second pre-tightening force can continuously press against the second stop portion 2221 of the second valve sleeve 222, thereby enabling the second spool 220 to continuously provide an upward pulling force to the first spool 210, so that the first spool 210 maintains the state of blocking the second valve port 102. Thus, under the action of the second pre-tightening force, the valve needle 211 can tightly block the second valve port 102, improving the sealing performance of the valve needle 211 blocking the second valve port 102.

[0067] As Figure 3 shown, there is a movable gap between the end face 2111 of the spool seat 221 and the valve needle 211 along the axial direction of the electronic expansion valve. This movable gap is used to adjust the opening valve pulse number of the electronic expansion valve. Specifically, by setting the size of this movable gap, the opening valve pulse number of the device can be adjusted according to the actual situation.

[0068] As Figure 3As shown, a first inner sealing ring 140 is further provided between the valve core assembly 200 and the cavity wall of the valve cavity 110. The first valve sleeve 212 of the first valve core 210 is movably and sealingly fitted with the cavity wall of the valve cavity 110 through the first inner sealing ring 140, and a first sealing ring is formed at the sealing position between the first valve core 210 and the cavity wall of the valve cavity 110. The first valve core 210 has a second inner sealing ring 213. A second sealing ring is formed at the position where the second inner sealing ring 213 seals with the first valve port 101, and a third sealing ring is formed at the position where the second inner sealing ring 213 seals with the second valve port 102. The diameter D2 of the second sealing ring is greater than the diameter D1 of the first sealing ring, and the diameter D3 of the third sealing ring is greater than the diameter D1 of the first sealing ring.

[0069] It can be understood that by designing the diameter D2 of the second sealing ring to be greater than the diameter D1 of the first sealing ring and the diameter D3 of the third sealing ring to be greater than the diameter D1 of the first sealing ring, it is convenient to install the valve core assembly 200 into the valve cavity 110 from the bottom of the valve seat assembly 100.

[0070] However, such a design will cause the electronic expansion valve to no longer maintain internal balance as a whole, that is, the valve core assembly 200 is no longer balanced under the action of the fluid.

[0071] Therefore, for the electronic expansion valve according to the embodiment of the present application, the relationship between the first pre-tightening force F1 and D2, D1 satisfies the following inequality (π×D2 2 ÷4 - π×D1 2 ÷4)×ΔP1 < F1; where D2 is the diameter of the second sealing ring, D1 is the diameter of the first sealing ring, and ΔP1 is the fluid pressure difference between the third opening 105 and the second opening 104 when the electronic expansion valve is filled with fluid.

[0072] The second pre-tightening force F2 and D3, D1 satisfy the following inequality: (π×D3 2 ÷4 - π×D1 2 ÷4)×ΔP2 < F2; where D3 is the diameter of the third sealing ring, D1 is the diameter of the first sealing ring, and ΔP2 is the fluid pressure difference between the first opening 103 and the second opening 104 when the electronic expansion valve is filled with fluid.

[0073] In the embodiment of the present application, F1, D1 and D2 satisfy (π×D2 2 ÷4 - π×D1 2 ÷4)×ΔP1 < F1, which can prevent fluid leakage caused by the valve needle 211 being pushed open by the reverse acting force of the fluid; similarly, F2, D1 and D3 satisfy (π×D3 2 ÷4 - π×D1 2 ÷4)×ΔP2 < F2, which can prevent fluid leakage caused by the valve needle 211 being pushed open by the reverse acting force of the fluid.

[0074] Specifically, the second opening 104 of the valve seat assembly 100 is set as the fluid inlet, and the first opening 103 and the third opening 105 are set as the fluid outlets. When the valve needle 211 blocks the first valve port 101, the fluid enters from the second opening 104 and flows out from the first opening 103. At this time, the upper space of the second inner sealing ring 213 (i.e., the chamber corresponding to the second opening 104 and the first opening 103) is the high-pressure chamber, and the lower space of the second inner sealing ring 213 (i.e., the chamber corresponding to the third opening 105) is the low-pressure chamber. Under normal circumstances, the fluid enters from the second opening 104 and flows out from the first opening 103. At this time, the valve needle 211 is subjected to a downward fluid pressure, and the valve needle 211 will not be pushed open by the fluid. However, in abnormal circumstances, if the fluid suddenly enters from the third opening 105, the pressure formed by the fluid is (π×D2 2 ÷4 - π×D1 2 ÷4)×ΔP1, and the direction of the pressure is upward.

[0075] It can be seen that the first pre-tightening force F1 provided by the first elastic member 230 in the embodiment of the present application is > (π×D2 2 ÷4 - π×D1 2 ÷4)×ΔP1, which can effectively prevent the fluid pressure from pushing open the valve needle 211 and ensure the sealing performance of the valve needle 211 blocking the first valve port 101.

[0076] Similarly, when the valve needle 211 blocks the second valve port 102, the fluid enters from the second opening 104 and flows out from the third opening 105. At this time, the upper space of the second inner sealing ring 213 (i.e., the chamber corresponding to the first opening 103) is the low-pressure chamber, and the lower space of the second inner sealing ring 213 (i.e., the chamber corresponding to the second opening 104 and the third opening 105) is the high-pressure chamber. Under normal circumstances, the fluid enters from the second opening 104 and flows out from the third opening 105. At this time, the valve needle 211 is subjected to an upward fluid pressure, and the valve needle 211 will not be pushed open by the fluid. However, in abnormal circumstances, if the fluid suddenly enters from the first opening 103, the pressure formed by the fluid is (π×D3 2 ÷4 - π×D1 2 ÷4)×ΔP2, and the direction of the pressure is downward.

[0077] It can be seen that the second pre-tightening force F2 provided by the second elastic member 500 in the embodiment of the present application is > (π×D3 2 ÷4 - π×D1 2 ÷4)×ΔP2, which can effectively prevent the fluid pressure from pushing open the valve needle 211 and ensure the sealing performance of the valve needle 211 blocking the second valve port 102.

[0078] Such as Figure 3As shown, the first inner sealing ring 140 includes an outer sealing ring 141 and an inner sealing ring 142. The inner sealing ring 142 is sleeved on the outer periphery of the first valve sleeve 212. The outer sealing ring 141 surrounds the outer periphery of the inner sealing ring 142 and applies an elastic pre-tightening force towards the first valve sleeve 212 to the inner sealing ring 142. By adopting the combined sealing structure of the outer sealing ring 141 and the inner sealing ring 142, the high-pressure resistance and wear resistance of the dynamic seal can be improved.

[0079] In one embodiment, the material of the inner sealing ring 142 can be polytetrafluoroethylene, but it is not limited thereto.

[0080] It can be understood that the diameter D1 of the first sealing ring is the outer diameter dimension of the first valve sleeve 212. The diameter D2 of the second sealing ring is the circular diameter formed by the tangent points between the R corner at the edge of the first valve port 101 and the lower inclined surface of the second inner sealing ring 213. The diameter D3 of the third sealing ring is the circular diameter formed by the tangent points between the R corner at the edge of the second valve port 102 and the upper inclined surface of the second inner sealing ring 213.

[0081] Furthermore, in order to reduce the difference between D2 and D1, and the difference between D3 and D1, so that the electronic expansion valve is as close as possible to internal balance, it can be achieved by reducing the size of the R corner at the edge of the first valve port 101, increasing the taper of the lower inclined surface of the second inner sealing ring 213, reducing the size of the R corner at the edge of the second valve port 102, and increasing the taper of the upper inclined surface of the second inner sealing ring 213.

[0082] In one embodiment, the second inner sealing ring 213 is made of a flexible sealing material, such as rubber, polymer, plastic, etc. In this way, the sealing performance of the second inner sealing ring 213 when plugging the first valve port 101 or the second valve port 102 can be improved, and leakage can be prevented.

[0083] When the first valve port 101 is closed, at least part of the lower inclined surface of the second inner sealing ring 213 is located within the first valve port 101, which can ensure that when the spool assembly 200 is skewed, the spool assembly 200 can be corrected through the lower inclined surface of the second inner sealing ring 213. When the second valve port 102 is closed, at least part of the upper inclined surface of the second inner sealing ring 213 is located within the second valve port 102, which can ensure that when the spool assembly 200 is skewed, the spool assembly 200 can be corrected through the upper inclined surface of the second inner sealing ring 213.

[0084] As Figure 3 shown, the inner peripheral surface of one of the first valve seat 120 and the second valve seat 130 is in guiding fit with the outer peripheral surface of the first valve sleeve 212, and there is a first gap between the inner peripheral surface and the outer peripheral surface, and there is a second gap between the inner peripheral surface of the other and the outer peripheral surface of the first valve sleeve 212; the first gap is smaller than the second gap.

[0085] For example, the inner peripheral surface of the first valve seat 120 is in clearance fit with the outer peripheral surface of the first valve sleeve 212, and there is a second gap between the inner peripheral surface and the outer peripheral surface; the inner peripheral surface of the second valve seat 130 is in guiding fit with the outer peripheral surface of the first valve sleeve 212, and there is a first gap between the inner peripheral surface and the outer peripheral surface.

[0086] Of course, in other embodiments, it may also be that the inner peripheral surface of the first valve seat 120 is in guiding fit with the outer peripheral surface of the first valve sleeve 212, and the inner peripheral surface of the second valve seat 130 is in clearance fit with the outer peripheral surface of the first valve sleeve 212.

[0087] It can be seen from this that only one inner peripheral surface of the valve seat in the valve seat assembly 100 is in small-gap guiding fit with the outer peripheral surface of the first valve sleeve 212, and the remaining valve seats maintain a relatively large clearance fit. In this way, it is possible to avoid jamming of the valve core assembly 200 during movement due to the inner peripheral surfaces of the valve seat assembly 100 being all designed as guiding fits.

[0088] As Figure 6 shown, one of the valve needle 211 and the first valve sleeve 212 has a connection hole 212a, and the other has a connection shaft 211a for inserting into the connection hole 212a. At least a part of the first elastic member 230 is located in the connection hole 212a and can be abutted by the connection shaft 211a. When the axial dimension of the connection shaft 211a inserted into the connection hole 212a is less than or equal to the first target value, the first elastic member 230 is in its original length state.

[0089] When assembling the valve core assembly 200 according to the embodiment of the present application, first insert the second valve core 220 and the screw 300 into the first valve sleeve 212, then install the first elastic member 230 into the first valve sleeve 212, and finally connect the valve needle 211 to the first valve sleeve 212 to enclose the first elastic member 230 in the first valve sleeve 212. When connecting the valve needle 211 to the first valve sleeve 212, first insert the connection shaft 211a into the connection hole 212a. When the axial dimension of the part of the connection shaft 211a inserted into the connection hole 212a is less than or equal to the first target value, the first elastic member 230 is in its original length state. On the one hand, the inner wall surface of the connection hole 212a can play a guiding role to guide the connection shaft 211a to insert into the connection hole 212a; on the other hand, since the first elastic member 230 is in its original length state when the axial dimension of the connection shaft 211a inserted into the connection hole 212a is less than or equal to the first target value, at this time the first elastic member 230 does not generate an elastic force, that is to say, in the initial stage of inserting the connection shaft 211a into the connection hole 212a, the connection shaft 211a will not be subjected to the reaction force provided by the first elastic force, improving the smoothness of inserting the connection shaft 211a into the connection hole 212a, and thus improving the assembly efficiency.

[0090] In one embodiment, the first target value is greater than or equal to 0.5 mm, but not limited thereto.

[0091] When the connecting shaft 211a and the connecting hole 212a are in interference fit, one end of the first elastic member 230 abuts against the second valve core 220, and the other end abuts against the connecting shaft 211a.

[0092] In one embodiment, the valve needle 211 has a connecting shaft 211a, and the first valve sleeve 212 has a connecting hole 212a. Of course, in other embodiments, the valve needle 211 has a connecting hole 212a, and the first valve sleeve 212 has a connecting shaft 211a.

[0093] Next, an example will be given with the valve needle 211 having a connecting shaft 211a and the first valve sleeve 212 having a connecting hole 212a for illustration.

[0094] As Figure 6 shown, one of the outer peripheral surface of the connecting shaft 211a and the inner wall surface of the connecting hole 212a has a stepped surface, and the other has a surface that is in clearance fit or interference fit with the stepped surface.

[0095] In one embodiment, the connecting shaft 211a has a first fitting section 2113 and a second fitting section 2114. The first fitting section 2113 and the second fitting section 2114 are arranged along the axial direction of the connecting shaft 211a and form a stepped surface. The first fitting section 2113 is used for clearance fit with the inner wall surface of the connecting hole 212a, and the second fitting section 2114 is used for interference fit with the inner wall surface of the connecting hole 212a.

[0096] Wherein, when the axial dimension of the connecting shaft 211a inserted into the connecting hole 212a is less than or equal to the first target value, at least part of the first fitting section 2113 is located in the connecting hole 212a, and the first fitting section 2113 is in clearance fit with the inner wall of the connecting hole 212a. When the axial dimension of the connecting shaft 211a inserted into the connecting hole 212a is greater than the first target value, the first fitting section 2113 is entirely located in the connecting hole 212a, the first fitting section 2113 is in clearance fit with the inner wall of the connecting hole 212a, at least part of the second fitting section 2114 is located in the connecting hole 212a, and the second fitting section 2114 is in interference fit with the inner wall of the connecting hole 212a.

[0097] In another embodiment, the inner wall surface of the connecting hole 212a has a stepped surface, and the outer peripheral surface of the connecting shaft 211a has a surface that is first in clearance fit and then in interference fit with the stepped surface.

[0098] As Figure 6As shown, the valve needle 211 further has a fourth stop portion 2115 for stopping the other one of the first component and the second component when the connecting shaft 211a and the connecting hole 212a are in interference fit and the axial dimension of the part of the connecting shaft 211a inserted into the connecting hole 212a reaches a second target value; wherein, the second target value is greater than the first target value. By providing the fourth stop portion 2115 on the valve needle 211, it is possible to prevent the dimension of the connecting shaft 211a inserted into the connecting hole 212a from being too long during the assembly of the valve needle 211 and the first valve sleeve 212, resulting in inconvenient disassembly.

[0099] Of course, in other embodiments, when the valve needle 211 has a connecting hole 212a and the first valve sleeve 212 has a connecting shaft 211a, the fourth stop portion 2115 can be provided on the first valve sleeve 212.

[0100] In one embodiment, the fourth stop portion 2115 is an annular protrusion surrounding the outer peripheral surface of the connecting shaft 211a for abutting against the periphery of the connecting hole 212a.

[0101] In other embodiments, the fourth stop portion 2115 may include a plurality of sub-protrusions arranged circumferentially along the connecting shaft 211a.

[0102] As Figure 2 and Figure 3 As shown, the top of the valve chamber 110 has a back pressure chamber 111, and the valve core assembly 200 has a first balance channel 201 communicating with the back pressure chamber 111 and the valve port 110a. The electronic expansion valve of the embodiment of the present application further includes a guiding structure 600 for guiding the movement of the valve core assembly 200 relative to the valve seat assembly 100; the guiding structure 600 has a second balance channel 601 communicating with the first balance channel 201 and the valve port 110a.

[0103] In the embodiment of the present application, the electronic expansion valve includes a guiding structure 600 for guiding the movement of the valve core assembly 200. The guiding structure 600 can effectively avoid the problem that the valve core assembly 200 is prone to tilt and cannot be aligned with the valve port after being impacted by the fluid impact force. In addition, the valve core assembly 200 has a first balance channel 201 communicating with the back pressure chamber 111 and the valve port 110a, and the guiding structure 600 has a second balance channel 601 communicating with the first balance channel 201 and the valve port 110a, so that the electronic expansion valve is an internal balance valve as a whole, improving the ability to open and close the valve.

[0104] Wherein, in the embodiment of the present application, the valve needle 211 and the valve core seat 221 of the valve core assembly 200 have mutually communicating channels, and the valve core seat 221 has an opening communicating with the channel of the valve core seat 221. Each channel and the opening together constitute the first balance channel 201.

[0105] As Figure 2 andFigure 3 As shown in the figure, the guiding structure 600 includes a connecting portion 610 and a guiding portion 620. The connecting portion 610 is connected to the cavity wall of the valve cavity 110 and has a second balance channel 601; the guiding portion 620 is connected to one of the connecting portion 610 and the valve core assembly 200 and is in guiding cooperation with the other. In one embodiment, the connecting portion 610 has a plurality of second balance channels 601, and the plurality of second balance channels 601 are arranged along the circumferential direction of the guiding portion 620.

[0106] The guiding portion 620 is a guiding hole 621, and the guiding hole 621 axially penetrates through the connecting portion 610 along the electronic expansion valve; the valve needle 211 of the valve seat assembly 100 is inserted into the guiding hole 621, and the outer peripheral surface of the valve needle 211 of the valve seat assembly 100 is in guiding cooperation with the hole wall of the guiding hole 621.

[0107] As Figure 7 and Figure 8 shown, the same parts of the second embodiment of the present application and the first embodiment will not be described in detail, and the differences are as follows:

[0108] The guiding portion 620 includes a first guiding rod 622 and a guiding column 623. One end of the first guiding rod 622 is connected to the connecting portion 610, and the other end is connected to the guiding column 623; the guiding column 623 extends into the first balance channel 201, and the outer peripheral surface of the guiding column 623 is in guiding cooperation with the inner wall surface of the first balance channel 201.

[0109] The outer periphery of the guiding column 623 has a first cutting surface 623a, the first cutting surface 623a penetrates through the two first end surfaces 623b of the guiding column 623, and the first cutting surface 623a and the inner wall surface of the first balance channel 201 enclose a third balance channel 602, and the first balance channel 201 is communicated with the valve port through the third balance channel 602.

[0110] In another embodiment, the guiding portion 620 includes a first guiding rod 622 and a guiding column 623; one end of the guiding column 623 extends into the first balance channel 201 and is connected to the valve core assembly 200, and the other end is connected to the first guiding rod 622; the connecting portion 610 also has a guiding hole 621 axially penetrating therethrough, and the outer peripheral surface of the first guiding rod 622 is in guiding cooperation with the hole wall of the guiding hole 621.

[0111] As Figure 9 and Figure 10 shown, the same parts of the third embodiment of the present application and the first embodiment will not be described in detail, and the differences are as follows:

[0112] The guiding portion 620 includes a second guiding rod 624, one end is connected to the connecting portion 610, and the other end extends into the first balance channel 201; the outer peripheral surface of the second guiding rod 624 is in guiding cooperation with the inner wall surface of the first balance channel 201.

[0113] The outer periphery of the second guide rod 624 has a second cutting surface 624a, and one end of the second cutting surface 624a extends to the second end surface 624b of the second guide rod 624 located in the first balance channel 201; the second cutting surface 624a and the inner wall surface of the first balance channel 201 enclose a fourth balance channel 603, and the first balance channel 201 is communicated with the valve port through the fourth balance channel 603.

[0114] In one embodiment, the number of the second cutting surfaces 624a is multiple, and the multiple second cutting surfaces 624a are arranged along the circumferential direction of the second guide rod 624. Of course, in other embodiments, the number of the second cutting surfaces 624a can also be one.

[0115] In another embodiment, the guiding portion 620 includes a second guide rod 624, and the connecting portion 610 further has a guiding hole 621 axially penetrating therethrough; one end of the second guide rod 624 enters the first balance channel 201 and is connected to the valve core assembly 200, and the other end is in guiding fit with the hole wall of the guiding hole 621.

[0116] As Figure 11 and Figure 12 shown, the same parts of the fourth embodiment of the present application and the first embodiment will not be described in detail, and the differences therebetween are as follows:

[0117] The second guide rod 624 internally has a fifth balance channel 604, and the fifth balance channel 604 penetrates through the two second end surfaces 624b of the second guide rod 624; the first balance channel 201 is communicated with the second balance channel 601 through the fifth balance channel 604.

[0118] As Figure 13 shown, the same parts of the fifth embodiment of the present application and the fourth embodiment will not be described in detail, and the differences therebetween are as follows:

[0119] The electronic expansion valve according to the embodiment of the present application further includes a mounting seat 700, the mounting seat 700 has a mounting cavity 704, and at least part of the valve seat assembly 100 is inserted into the mounting cavity 704.

[0120] The mounting seat 700 further has an inlet 701, a first outlet 702 and a second outlet 703 communicated with the mounting cavity 704, the inlet 701 is communicated with the second opening 104 of the valve seat assembly 100, the first outlet 702 is communicated with the first opening 103 of the valve seat assembly 100, and the second outlet 703 is communicated with the third opening 105 of the valve seat assembly 100. Wherein, the third opening 105 is opened at the bottom of the third valve seat 150.

[0121] As Figure 14 shown, the same parts of the sixth embodiment of the present application and the fifth embodiment will not be described in detail, and the differences therebetween are as follows:

[0122] The length of the third valve seat 150 of the embodiment of the present application along the axial direction of the electronic expansion valve is greater than the axial length of the third valve seat 150 of the fifth embodiment, and the third opening 105 is formed in the side portion of the third valve seat 150.

[0123] As Figure 15 shown, the similarities between the seventh embodiment and the fifth embodiment of the present application will not be described in detail, and the differences are as follows:

[0124] The electronic expansion valve does not have a guiding structure 600.

[0125] It can be understood that the electronic expansion valves of the first to fourth embodiments of the present application may not be provided with a mounting seat 700, but the first opening 103, the second opening 104, and the third opening 105 are directly connected to an external connecting pipe.

[0126] In summary, the electronic expansion valve of the embodiment of the present application has at least the following advantages and beneficial effects:

[0127] The electronic expansion valve of the embodiment of the present application includes a first elastic member 230 and a second elastic member 500. The first elastic member 230 can apply a first pre-tightening force to the first valve core 210 to block the first valve port 101, and the second elastic member 500 can apply a second pre-tightening force to the first valve core 210 to block the second valve port 102. In this way, the sealing performance of the first valve core 210 for blocking the first valve port 101 or the second valve port 102 is significantly improved, preventing fluid leakage of the electronic expansion valve and improving the working reliability. In addition, in the electronic expansion valve of the embodiment of the present application, the screw 300 drives the first valve core 210 to move between a first position and a second position through the second valve core 220. Moreover, the first pre-tightening force provided by the first elastic member 230 acts on the first valve core 210 and the second valve core 220 respectively, and the second pre-tightening force provided by the second elastic member 500 acts on the screw 300 and the second valve core 220 respectively, so that the first pre-tightening force and the second pre-tightening force do not affect each other, ensuring that the first pre-tightening force and the second pre-tightening force are large enough, and further improving the sealing performance when the first valve core 210 blocks the first valve port 101 and the second valve port 102.

[0128] When the axial dimension of the portion of the connecting shaft 211a inserted into the connecting hole 212a is less than or equal to the first target value in the clearance fit state, the first elastic member 230 is in its original length state. On the one hand, the connecting shaft 211a and the connecting hole 212a are in a clearance fit state, and the inner wall surface of the connecting hole 212a can play a guiding role to guide the connecting shaft 211a to be inserted into the connecting hole 212a. On the other hand, since the first elastic member 230 is in its original length state when the axial dimension of the portion of the connecting shaft 211a inserted into the connecting hole 212a is less than or equal to the first target value, the first elastic member 230 does not generate an elastic force at this time. That is to say, in the initial stage when the connecting shaft 211a is inserted into the connecting hole 212a, the connecting shaft 211a will not be subjected to the reaction force provided by the first elastic force, improving the smoothness of inserting the connecting shaft 211a into the connecting hole 212a, and thus improving the assembly efficiency.

[0129] The electronic expansion valve according to the embodiment of the present application includes a guiding structure 600 for guiding the movement of the valve core assembly 200. The guiding structure 600 can effectively avoid the problem that the valve core assembly 200 is prone to tilt and cannot be aligned with the valve port after being affected by the fluid impact force. In addition, the valve core assembly 200 has a first balance channel 201 communicating with the back pressure chamber 111 and the valve port 110a, and the guiding structure 600 has a second balance channel 601 communicating with the first balance channel 201 and the valve port 110a, making the electronic expansion valve an internal balance valve as a whole and improving the ability to open and close the valve.

[0130] It can be understood that the various embodiments / implementation manners provided in the present application can be combined with each other without conflict, and no further examples will be given here.

[0131] In the embodiments of the application, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. Terms such as "installation", "connection", "connection", and "fixation" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the application can be understood according to specific circumstances.

[0132] In the description of the embodiments of the application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the application and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the application.

[0133] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the claimed embodiment. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0134] The above are only the preferred embodiments of the claimed embodiment and are not used to limit the claimed embodiment. For those skilled in the art, the claimed embodiment may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the claimed embodiment shall be included within the protection scope of the claimed embodiment.

Claims

1. An electronic expansion valve, characterized in that: include: The valve seat assembly comprises a valve cavity, a cavity wall of the valve cavity comprises a valve port, and a top of the valve cavity comprises a back pressure cavity; A valve core assembly, at least part of which is disposed in the valve cavity and is movable along the axial direction of the electronic expansion valve, and is used to block or open the valve port; the valve core assembly has a first balancing channel in communication with the back pressure cavity and the valve port; as well as The guide structure is used for guiding the valve core assembly to move relative to the valve seat assembly; the guide structure has a second balance channel connected with the first balance channel and the valve port.

2. The electronic expansion valve according to claim 1, characterized in that: The guiding structure comprises: a connecting portion connected to a cavity wall of the valve cavity and having the second balancing channel; and The guide portion is connected to one of the connecting portion and the valve core assembly and cooperates with the other guide.

3. The electronic expansion valve according to claim 2, characterized in that: The guide portion is a guide hole, and the guide hole penetrates the connecting portion along the axial direction of the electronic expansion valve; The valve core assembly is inserted into the guide hole, and the outer peripheral surface of the valve core assembly is guided and matched with the hole wall of the guide hole.

4. The electronic expansion valve according to claim 2, characterized in that: The guide portion includes a first guide rod and a guide column, one end of the first guide rod is connected to the connection portion, and the other end is connected to the guide column; the guide column extends into the first balancing channel, and the outer peripheral surface of the guide column is in guiding cooperation with the inner wall surface of the first balancing channel; Alternatively, the guide portion includes a first guide rod and a guide column; one end of the guide column extends into the first balancing channel and is connected to the valve core assembly, and the other end is connected to the first guide rod; the connecting portion also has an axially penetrating guide hole, and the outer peripheral surface of the first guide rod is guided and matched with the hole wall of the guide hole.

5. The electronic expansion valve according to claim 4, characterized in that: The outer periphery of the guide column has a first section, the first section passes through the two first end surfaces of the guide column, the first section and the inner wall surface of the first balancing channel form a third balancing channel, and the first balancing channel is connected to the valve port through the third balancing channel.

6. The electronic expansion valve according to claim 2, characterized in that: The guide portion includes a second guide rod, one end of which is connected to the connection portion, and the other end of which extends into the first balancing channel; the outer peripheral surface of the second guide rod is in guiding cooperation with the inner wall surface of the first balancing channel; Alternatively, the guide portion includes a second guide rod, and the connecting portion further has an axially penetrating guide hole; one end of the second guide rod enters the first balancing channel and is connected to the valve core assembly, and the other end cooperates with the hole wall of the guide hole for guidance.

7. The electronic expansion valve according to claim 6, characterized in that: The outer periphery of the second guide rod has a second section; one end of the second section extends to a second end surface of the second guide rod located in the first balancing channel; The second section and the inner wall surface of the first balancing channel form a fourth balancing channel, and the first balancing channel is connected to the valve port through the fourth balancing channel.

8. The electronic expansion valve according to claim 7, characterized in that: There are a plurality of second sections, which are arranged along the circumference of the second guide rod.

9. The electronic expansion valve according to claim 6, characterized in that: A fifth balancing channel is provided inside the second guide rod, and the fifth balancing channel runs through two second end surfaces of the second guide rod; The first balancing channel is in communication with the second balancing channel through the fifth balancing channel.

10. The electronic expansion valve according to any one of claims 2 to 9, characterized in that: The connecting portion has a plurality of the second balancing channels, and the plurality of the second balancing channels are arranged along the circumference of the guide portion.

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