Electronic expansion valve

Abstract

The application discloses an electronic expansion valve, which comprises a valve core component and a valve seat component formed with a valve port, and is formed with a valve cavity containing fluid. The valve core component can move in the axial direction to adjust the opening degree of the valve port. The valve core component is provided with a first matching part, and the valve seat component is provided with a second matching part. During the movement of the valve core component to block the valve port, the first matching part and the second matching part can be close to each other and matched to form a cavity, the cavity contains part of the fluid in the valve cavity, and the first matching part gradually compresses the fluid in the cavity. When the valve is closed, the fluid cannot be quickly discharged, the fluid pressure in the cavity will be increased, and then a buffer force can be provided for the valve core component, so that the purpose of buffering the impact of the valve core component on the valve port is achieved, thereby reducing the wear of the abutting position of the valve core component and the valve port, and the service life of the electronic expansion valve is prolonged.

Description

Technical Field

[0001] This invention relates to the field of fluid control technology, and more specifically to an electronic expansion valve. Background Technology

[0002] Please refer to Figure 1 , Figure 1 This is a schematic diagram of an electronic expansion valve.

[0003] like Figure 1 As shown, the electronic expansion valve includes a valve seat component 1', a valve core component 2', a lead screw component 4', a rotor component 6', a housing component, a coil component 9', and a nut 3'. The valve seat component 1 forms the valve cavity and valve port 1a' of the electronic expansion valve. The valve seat component 1 is also provided with a first interface and a second interface for fluid to flow into or out of the valve cavity, and the valve port 1a' is connected or disconnected via the first interface and the second interface.

[0004] When the flow path needs to be opened, the magnetic field generated by coil component 9' passes through housing component 7', driving rotor component 6' to rotate. Rotor component 6' drives lead screw component 4' to rotate. Lead screw component 4' is threadedly connected to nut 3', so lead screw component 4' can move upward. Valve core component 2' is fixed to bushing 5'. When lead screw component 4' moves upward, it carries bushing 5' upward, thereby driving valve core component 2' to move upward. When the flow path is closed, the magnetic field generated by coil component 9' passes through housing component 7', driving rotor component 6 to rotate in the opposite direction. Rotor component 6' drives lead screw component 4' to rotate in the opposite direction. Lead screw component 4' is threadedly connected to nut 3', so lead screw component 4' moves downward. When lead screw component 4' moves downward, it presses the top shaft 10' fixed on lead screw component 4' downward. Top shaft 10' presses the lower pressure spring 8' downward. Lower pressure spring 8' presses the gasket and valve core component 2' downward, thus closing valve port 1a'.

[0005] When the valve core component 2' moves downward, it will impact the valve port contact position of the valve seat 1 due to its own power. After a large number of impacts, the valve port 1a' position of the valve seat component 1' and the position in contact with the valve core component 2 will be worn. After repeated wear, the solenoid valve may fail to close, affecting the service life of the electronic expansion valve. Summary of the Invention

[0006] This invention provides an electronic expansion valve, including a valve core component and a valve seat component with a valve port. The electronic expansion valve has a valve cavity containing fluid. The valve core component is axially movable to adjust the opening of the valve port. The valve core component has a first mating part, and the valve seat component has a second mating part. During the process of the valve core component moving to block the valve port, the first mating part and the second mating part can approach each other and cooperate to form a cavity. The cavity contains a portion of the fluid in the valve cavity, and the first mating part gradually compresses the fluid in the cavity.

[0007] In one embodiment, the electronic expansion valve further includes a fluid passage, and the valve seat component forms a valve cavity, the fluid passage connecting the cavity and the valve cavity and / or the valve port. In another embodiment, the fluid passage is located in at least one of the valve seat component and the valve core component.

[0008] In one specific embodiment, the fluid channel is a gap formed between the first mating part and the second mating part, and the distance at the widest point of the gap is greater than 0.1 mm.

[0009] In one specific embodiment, the first mating part includes a first stepped part, and the second mating part includes a second stepped part facing the opposite direction to the first stepped part, and the first stepped part and the second stepped part are arranged opposite each other along the axial direction.

[0010] In one specific embodiment, the valve seat is provided with an axial through hole, the axial through hole including a first hole, a second hole and a third hole distributed sequentially along the axial direction with gradually decreasing diameters, the joint position of the hole walls of the first hole and the second hole forms the second step portion, and the joint position of the third hole and the second hole forms the valve port.

[0011] In one specific embodiment, the valve core component includes a valve stem and a valve needle located at one end of the valve stem, wherein the position where the valve needle and the valve stem meet forms the first stepped portion.

[0012] In one specific embodiment, the valve stem slides into contact with the first hole, and the wall of the first hole or the outer wall of the valve stem is provided with a first groove, the first groove connecting the cavity and the valve cavity; and / or, the valve needle slides into contact with the second hole, and the wall of the second hole or the outer wall of the valve needle is provided with a second groove, the second groove connecting the cavity and the second hole, the second hole connecting the valve port.

[0013] In one specific embodiment, a first gap is formed between the valve stem and the wall of the first hole, the first gap connecting the cavity and the valve cavity; and / or, a second gap is formed between the valve needle and the wall of the second hole, the second gap connecting the cavity and the second hole, the second hole connecting the valve port.

[0014] In one specific embodiment, the valve needle has a tapered end that mates with the valve port. The tapered end can form a sealing cavity with the hole wall and bottom wall of the third hole. The valve seat is also provided with a pressure-reducing channel that connects to the sealing cavity. The sealing cavity is connected to the cavity body through the second gap.

[0015] In one specific embodiment, when the end of the valve core component facing the valve port is flush with the valve port, the first mating part and the second mating part begin to cooperate to form the cavity.

[0016] In one specific embodiment, when the valve core component completely closes the valve port, the cavity is still formed between the first mating portion and the second mating portion.

[0017] In this design, the first and second mating parts can form a cavity containing fluid during the valve closing process. The cavity is compressed as the valve core component continues to move closer to the valve port. That is, the volume of the cavity changes dynamically with the movement of the valve needle component. In this way, the valve core component will compress the fluid in the cavity. Since the cavity is a relatively closed space, the fluid cannot be discharged quickly, so the fluid pressure in the cavity will increase. This can provide a buffer force to the valve core component, thereby achieving the purpose of buffering the impact of the valve core component on the valve port, reducing wear on the valve core component and the valve port contact position, and helping to extend the service life of the electronic expansion valve. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an electronic expansion valve;

[0019] Figure 2 This is a schematic diagram of the electronic expansion valve in the first embodiment of this application;

[0020] Figure 3 for Figure 2 A schematic diagram showing the middle valve port in the fully open state;

[0021] Figure 4 for Figure 3 Schematic diagram of the central valve core component;

[0022] Figure 5 for Figure 3 Schematic diagram of the middle valve seat component;

[0023] Figure 6 for Figure 3A schematic diagram of the valve core component when it is close to the valve port;

[0024] Figure 7 for Figure 3 A schematic diagram of the valve core component when the valve port is closed;

[0025] Figure 8 This is a schematic diagram showing the mating position of the valve core component and valve seat component of the electronic expansion valve in the second embodiment of this application, illustrating the closed valve state;

[0026] Figure 9 This is a schematic diagram of the valve core component and valve seat component of the electronic expansion valve in the third embodiment of this application, illustrating the valve closed state.

[0027] Figure 10 This is a schematic diagram showing the mating position of the valve core component and valve seat component of the electronic expansion valve in the fourth embodiment of this application, illustrating the closed valve state. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the electronic expansion valve in the first embodiment of this application.

[0031] like Figure 2 As shown, the electronic expansion valve of this embodiment includes a valve seat component 1, a valve core component 2, a lead screw component 4, a rotor component 6, a housing component 12, a coil component 9, and a nut 3. The valve seat component 1 forms a valve chamber 1c and a valve port 1a of the electronic expansion valve. The valve seat component 1 is externally connected to a first interface pipe 100 and a second interface pipe 200 to allow fluid to flow into or out of the valve chamber 1c. The valve port 1a controls the opening and closing of the first interface pipe 100 and the second interface pipe 200.

[0032] When the flow path needs to be opened, the magnetic field generated by coil component 9 passes through housing component 12, driving rotor component 6 to rotate. Rotor component 6 drives lead screw component 4 to rotate. Lead screw component 4 is threadedly connected to nut 3, so lead screw component 4 can move upward. Valve core component 2 is fixed to bushing 5. When lead screw component 4 moves upward, it carries bushing 5 upward, thereby driving valve core component 2 upward. When the flow path is closed, the magnetic field generated by coil component 9 passes through housing component, driving rotor component 6 to rotate in the opposite direction. Rotor component 6 drives lead screw component 4 to rotate in the opposite direction. Lead screw component 4 is threadedly connected to nut 3, so lead screw component 4 moves downward. When lead screw component 4 moves downward, it presses the top shaft 10 fixed on lead screw component 4 downward. The top spring 11 also applies a force to the top shaft 10 to move downward. The top shaft 10 then presses the lower spring 8 downward. The lower spring 8 presses the gasket 7 and valve core component 2 downward, thus closing valve port 1a.

[0033] like Figure 3-5 As shown, Figure 3 for Figure 2 A schematic diagram showing the middle valve port 1a in the fully open state; Figure 4 for Figure 3 Schematic diagram of valve core component 2; Figure 5 for Figure 3 A schematic diagram of the middle valve seat component 1.

[0034] In this embodiment, the valve core component 2 includes a valve stem 21 and a valve needle 22 located at one end of the valve stem 21. The end of the valve needle 22 is tapered, which can better seal the valve port 1a and can adjust the opening degree of the valve port 1a according to the different lengths extended into the valve port 1a. At this time, the outer diameter of the valve needle 22 is smaller than the outer diameter of the valve stem 21, and the position where the two meet forms a first step portion 2a, such as... Figure 4 As shown, the first step portion 2a includes a step surface 21a and a step sidewall 22a. The step sidewall 22a extends axially and is part of the outer wall of the valve needle 22. The step surface 21a is disposed downward toward the valve port 1a.

[0035] Continue reading Figure 5 The valve seat component 1 is provided with an axial through hole, which includes a first hole 1d, a second hole 1e, and a third hole 1f, which are distributed sequentially along the axial direction and have gradually decreasing diameters. Figure 5 The first hole 1d, the second hole 1e, and the third hole 1f gradually decrease in size from top to bottom. At this point, the wall of the axial through hole forms two steps accordingly. The junction of the walls of the first hole 1d and the second hole 1e forms the second step 1g, with the step surface 12 of the second step 1g facing upwards toward the valve cavity 1c. The junction of the walls of the second hole 1e and the third hole 1f forms the third step, with the step surface of the third step flush with the valve port 1a. Figure 5 As shown, the valve port 1a is formed at the position where the third hole 1f and the second hole 1e meet.

[0036] Let's look again. Figure 3 The first step portion 2a of the valve core component 2 and the second step portion 1g of the valve seat component 1 are arranged opposite to each other, with their steps facing opposite directions. Figure 3 From a perspective, the step surface 21a of the first step 2a faces downwards, and the step surface 12 of the second step 1g faces upwards. The two step parts are arranged opposite each other, that is, the radial projections of their step surfaces roughly overlap. Figure 3 The first step 2a and the second step 1g are spaced apart, and no cavity a is formed between them.

[0037] As the valve core component 2 moves axially toward the valve port 1a, the first step portion 2a and the second step portion 1g gradually approach each other. Please continue to refer to [the relevant documentation]. Figure 6 , 7 , Figure 6 for Figure 3 A schematic diagram of the valve core component 2 when it is close to the valve port 1a; Figure 7 for Figure 3 A schematic diagram of the valve core component 2 when valve port 1a is closed.

[0038] exist Figure 3 In its current position, after the valve core component 2 continues to move a certain distance, the first step portion 2a and the second step portion 1g can close together to form cavity a. Figure 6 When the lowest point of the conical end of the valve needle 22 reaches the valve port 1a, the valve needle 22 is about to penetrate into the valve port 1a to adjust the opening. The valve needle 22 will also quickly seal the valve port 1a. At this time, the first step 2a and the second step 1g enclose to form cavity a. Since the first step 2a and the second step 1g are open in the valve cavity 1c before they are enclosed, and the fluid flows at the positions of the first step 2a and the second step 1g, when they are enclosed, some of the fluid near them can be contained in cavity a. At this time, when the valve core component 2 continues to move in the direction of closing the valve port 1a, the valve needle 22... The conical end gradually extends into the valve port 1a. Correspondingly, the volume of cavity a between the first step 2a and the second step 1g will also be compressed and reduced. That is, after cavity a is formed, its volume will gradually decrease as the valve core component 2 continues to move closer to the valve port 1a. In other words, the volume of cavity a changes dynamically with the movement of the valve needle component 2. In this way, the valve core component 2 will compress the fluid in cavity a. Since cavity a is a relatively closed space, the fluid cannot be discharged quickly, so the fluid pressure in cavity a will increase. This can then provide a buffering force to the valve core component 2, achieving the purpose of buffering the impact of the valve core component 2 on the valve port 1a. Figure 7 As shown, when the valve core component 2 seals the valve port 1a, the cavity a formed between the first step portion 2a and the second step portion 1g becomes the smallest.

[0039] It is understandable that when the valve is closed, the step surface 21a of the first step 2a and the step surface 12 of the second step 1g should preferably have a certain distance. This can prevent the first step 2a and the second step 1g from contacting each other before the valve is closed, thus affecting the closing effect of the valve port 1a. That is, when the valve is fully closed, the cavity a still exists between the first step 2a and the second step 1g.

[0040] Furthermore, when the end of the valve core component 2 is flush with the valve port 1a, the valve core component 2 is about to begin reducing the opening of the valve port 1a until it is completely blocked. At this time, the first step 2a and the second step 1g are set to just begin to enclose and form cavity a. That is, a buffer cavity a is formed when the valve core component 2 is about to impact the valve port 1a. This buffering only occurs during the short period of the final valve closing. The valve core component 2 will not be subjected to buffering force during most of the valve closing stroke, ensuring the valve closing speed. Of course, the specific position of cavity a is not limited to this. It can be flexibly adjusted according to the actual situation of valve closing. For example, if the impact of the valve core component 2 is more obvious and the valve closing speed is faster, cavity a can be formed before the end is flush with the valve port 1a. Conversely, if the impact of the valve core component 2 is less obvious and the valve closing speed is slower, cavity a can be formed after the valve core component 2 extends into the valve port 1a. This application does not impose specific limitations on the embodiments.

[0041] Please check again. Figure 7 , Figure 7 The diagram illustrates that the valve stem 21 of the valve core component 2 has a first gap c with the wall of the first hole 1d. The distance at the widest point of the first gap c is greater than 0.1 mm. The specific value of the first gap c can be 0.1 mm, 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, or 2 mm, etc. The wall of the first hole 1d is the stepped sidewall 11 of the second step portion 1g. Thus, the first gap c can connect the cavity a and the valve cavity 1c. In this way, when the valve core component 2 moves down to cooperate with the valve seat component 1 to form the cavity a, and then continues to move down until the valve port 1a is closed, the fluid in the cavity a can be slowly discharged into the valve cavity 1c through the first gap c. The pressure of the valve needle 22 against the valve port 1a continuously increases until it reaches the maximum pressure, and the valve port 1a closes. Figure 7 As shown.

[0042] Figure 7The diagram also illustrates a second gap b between the outer wall of the valve needle 22 and the wall of the second hole 1e. The distance at the widest point of the second gap b is greater than 0.1 mm. The specific value of the second gap b can be 0.1 mm, 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, or 2 mm, etc. The outer wall of the valve needle 22 is the stepped side wall 22a of the first stepped portion 2a of the valve core component 2. The second gap b can connect the cavity a and the second hole 1e. After the valve core component 2 moves down and cooperates with the valve seat component 1 to form the cavity a, it continues to move down until the valve port 1a is not completely closed. The fluid in the cavity a can also slowly enter the second hole 1e through the second gap and be discharged from the valve port 1a. That is, the setting of the first gap c and the second gap b allows the cavity a to communicate with the valve cavity 1c or the valve port 1a, so as to ensure that the fluid in the cavity a can be discharged slowly. This ensures that the fluid pressure in the cavity a will not affect the valve closing. Figure 7 In the process, the axial through hole opened in the valve seat component 1 also includes an enlarged hole 1b connected to the valve port 1a. The fluid in the cavity a flows out through the valve port 1a to the enlarged hole 1b and then out. The enlarged hole 1b helps to reduce the impact of opening the valve.

[0043] The first gap c and the second gap b mentioned above are designed to allow the fluid inside cavity a to be discharged without affecting the formation of cavity a. If the size of the first gap c or the second gap b is too large, and the fluid discharged from the gap is too fast when the first step 2a and the second step 1g gradually approach each other, the purpose of squeezing the fluid to generate buffering force will not be achieved, and the cavity a required by this embodiment cannot be generated. Therefore, the setting of the first gap c and the second gap b can only achieve the function of slowly discharging the fluid.

[0044] Other examples Figure 7 As shown, the valve needle 22 has a tapered end. After the tapered end contacts the valve port 1a, the tapered end, the wall of the third hole, and the bottom wall will enclose an annular sealing cavity e with a triangular cross-section. At this time, a pressure-reducing channel d can be provided on the valve seat component 1. The pressure-reducing channel d connects the sealing cavity e and the valve cavity 1c. The sealing cavity e is connected to the cavity a through the second gap b. In this way, the fluid in the cavity a can flow into the valve cavity 1c through the second gap b, the sealing cavity e, and the pressure-reducing channel d, thereby ensuring the discharge of the fluid in the cavity a. That is, the second gap b, the sealing cavity e, and the pressure-reducing channel d are used as a fluid discharge channel. The setting of the pressure-reducing channel d allows the amount of fluid to be regulated. When there is a lot of fluid in the cavity a, if it cannot be discharged from the valve port 1a during the valve port closing process, it can flow out through the pressure-reducing channel d.

[0045] Example 2

[0046] Please continue to refer to this. Figure 8 , Figure 8 This is a schematic diagram of the mating position of the valve core component 2 and the valve seat component 1 of the electronic expansion valve in the second embodiment of this application, illustrating the closed valve state.

[0047] This embodiment is basically the same in structure as the first embodiment, except that a first groove 13 is provided on the wall of the first hole 1d of the valve seat component 1. The first groove 13 connects the valve cavity 1c and the cavity a to form a connecting channel between the valve cavity 1c and the cavity a. Its function is the same as that of the first gap c mentioned above, serving as a fluid channel for the fluid in the cavity a. When the valve core component 2 moves upward, the fluid can also enter the axial through hole of the valve seat component 1 through the fluid channel. It can be understood that either the first gap c or the first groove 13 can be provided, or both can be provided. When the first groove 13 is provided, the valve stem 21 and the wall of the first hole 1d can slide in contact to reduce the first gap c, thereby guiding the axial movement of the valve core component 2.

[0048] Example 3

[0049] Please continue to refer to this. Figure 9 , Figure 9 This is a schematic diagram of the valve core component 2 and valve seat component 1 of the electronic expansion valve in the third embodiment of this application, showing the valve closed state.

[0050] This embodiment is basically the same in structure as the first embodiment, except that a second groove 14 is provided on the wall of the second hole 1e of the valve seat component 1. The second groove 14 connects the valve cavity 1c and the second hole 1e to form a connecting channel between the valve cavity 1c and the cavity a, and its function is the same as that of the second gap b mentioned above. It can be understood that the second gap b and the groove can be provided separately or simultaneously. In fact, at least one of the first gap c, the second gap b, the first groove 13, and the second groove 14 is required. When the second groove 14 is provided, the valve stem 21 and the wall of the second hole 1e can slide and make contact to reduce the second gap b, thereby guiding the axial movement of the valve core component 2. It can also be understood that a groove can be provided on the outer wall of the valve needle or the valve stem to connect the cavity a and the valve cavity 1c or the valve port 1a.

[0051] It should be noted that in the above embodiment, the first step 2a is formed at the junction of the valve stem 21 and the valve needle 22, and the second step 1g is coaxially arranged with the valve port 1a. This arrangement requires less modification to the valve seat component 1 and the valve core component 2, and is easier to manufacture. However, it is understood that the positions of the first step 2a and the second step 1g are not limited to this. For example, with Figure 2From a certain perspective, the second step portion 1g is located on the upper part of the valve seat component 1, and the first step portion 2a is located at the corresponding position of the valve stem 21. In fact, the structure forming cavity a is not limited to two mating step portions. As long as the valve core component 2 has a first mating portion and the valve seat component 1 has a second mating portion, and the first and second mating portions can cooperate to form cavity a when the valve core component 2 moves along the valve closing direction, it is acceptable. For example, the second mating portion could also be a groove with an upward-facing opening on the valve seat component 1, and the first mating portion could be a downward-extending protrusion on the valve core component 2. When the protrusion moves downward, it inserts into the groove to form cavity a. This application does not specifically limit this aspect.

[0052] Example 4

[0053] Please continue to refer to this. Figure 10 , Figure 10 This is a schematic diagram showing the mating position of the valve core component and valve seat component of the electronic expansion valve in the fourth embodiment of this application, illustrating the closed valve state.

[0054] The structure of this embodiment is basically the same as that of the first embodiment, except that the axial through hole of the valve seat component in this embodiment only includes the first hole and the second hole, forming the first step portion. The position where the first hole and the second hole meet forms the valve port 1a. The valve needle 22 and the valve stem 21 of the valve core component 2 form the second step portion. The cavity a is formed between the second step portion and the first step portion. The effect is the same as that of the above embodiment, and will not be described again.

[0055] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An electronic expansion valve, comprising a valve core component and a valve seat component having a valve port, the electronic expansion valve having a valve cavity containing fluid, the valve core component being axially movable to adjust the opening degree of the valve port, characterized in that, The valve core component is provided with a first mating part, and the valve seat component is provided with a second mating part. The first mating part includes a first stepped part, and the second mating part includes a second stepped part facing the opposite direction to the first stepped part. The first stepped part and the second stepped part are arranged opposite to each other along the axial direction. The valve seat is provided with an axial through hole, which includes a first hole, a second hole and a third hole that are distributed sequentially along the axial direction and whose diameters gradually decrease. The joint position of the hole walls of the first hole and the second hole forms a second step portion. The joint position of the third hole and the second hole forms the valve port. The second step portion and the valve port are spaced apart along the axial direction, and the second step portion is located on the side of the valve port closer to the valve cavity. The valve core component includes a valve stem and a valve needle located at one end of the valve stem. The position where the valve needle and the valve stem meet forms the first stepped portion, and the valve needle has a tapered end that mates with the valve port. During the process of the valve core component moving to block the valve port, the first mating part and the second mating part can approach each other. When the lowest end of the cone reaches the valve port position, the first step part and the second step part surround to form a cavity. The cavity contains part of the fluid in the valve cavity, and the first mating part gradually compresses the fluid in the cavity. The electronic expansion valve is further provided with a fluid channel, the fluid channel connecting the cavity and the valve chamber and / or the valve port, the fluid channel including a gap formed between the first mating part and the second mating part; The fluid channel includes a second gap formed between the valve needle and the wall of the second hole, the second gap connecting the cavity and the second hole, and the second hole connecting the valve port; after the cavity is formed and the valve port is not completely closed, the fluid in the cavity can enter the second hole through the second gap and be discharged from the valve port; The conical end can form a sealing cavity with the hole wall and bottom wall of the third hole. The valve seat is also provided with a pressure reducing channel, which is connected to the sealing cavity. The sealing cavity is connected to the cavity body through the second gap, so that the fluid in the cavity body can flow into the valve cavity in sequence through the second gap, the sealing cavity and the pressure reducing channel.

2. The electronic expansion valve according to claim 1, characterized in that, The fluid passage is provided in at least one of the valve seat component and the valve core component.

3. The electronic expansion valve according to claim 1, characterized in that, The distance at the widest point of the gap is greater than 0.1 mm.

4. The electronic expansion valve according to claim 1, characterized in that, The valve stem slides into contact with the first hole, and the wall of the first hole or the outer wall of the valve stem is provided with a first groove, the first groove connecting the cavity and the valve cavity; and / or, the valve needle slides into contact with the second hole, and the wall of the second hole or the outer wall of the valve needle is provided with a second groove, the second groove connecting the cavity and the second hole, the second hole connecting the valve port; the fluid channel includes the first groove and / or the second groove, and the fluid channel is non-slit.

5. The electronic expansion valve according to claim 1, characterized in that, The fluid passage includes a first gap formed between the valve stem and the wall of the first hole, the first gap connecting the cavity and the valve cavity.

6. The electronic expansion valve according to any one of claims 1-5, characterized in that, When the end of the valve core component facing the valve port is flush with the valve port, the first mating part and the second mating part begin to cooperate to form the cavity. When the valve core component completely closes the valve port, the cavity is still formed between the first mating part and the second mating part.

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