Valve element assembly and electronic expansion valve

Abstract

A valve core assembly and an electronic expansion valve relate to the field of valves and comprise a valve seat, a valve port, a valve needle and a sealing element. Wherein the valve seat is provided with a positioning hole; the valve port is provided with an assembly hole, a side hole and an end hole which are communicated, the valve port is installed on the valve seat, and the assembly hole is communicated with the positioning hole. A balance hole is formed in the valve needle, the valve needle is slidably arranged in the positioning hole and the assembling hole in a penetrating mode, and one end of the balance hole communicates with the positioning hole; the sealing piece is connected outside the valve needle in a sleeving mode, makes contact with the hole wall of the positioning hole and is located on the side, close to the valve seat, of the valve port. The valve needle has a first position and a second position which are mutually switched, and when the valve needle is in the first position, the side hole is communicated with the end hole; in the second position, the side hole and the end hole are blocked by the valve needle, and the other end of the balance hole is communicated with the end hole. Through the design of the valve element assembly, the valve opening difficulty can be reduced, and a valve port is opened more smoothly; and bidirectional flow can be considered, and the use is flexible.

Description

Technical Field

[0001] This utility model relates to the field of valves, and more specifically, to a valve core assembly and an electronic expansion valve. Background Technology

[0002] Electronic expansion valves are important components in refrigeration and heating systems, primarily used to regulate the flow rate of refrigerant fluid. Existing electronic expansion valves typically consist of a drive mechanism, an actuator, a throttling mechanism, and related auxiliary mechanisms. Their main working principle is that the drive mechanism drives the actuator, which in turn drives the valve needle assembly to move axially, thereby regulating the fluid flow rate.

[0003] Traditional electronic expansion valves, when the system pressure is high, especially large-diameter valves (e.g., 5mm to 16mm in diameter), will experience a large pressure difference between the valve needle and the outlet after the valve port is closed. The motor driving force is insufficient to overcome this pressure difference, making it difficult to reopen. In addition, traditional electronic expansion valves generally regulate flow in one direction and cannot accommodate bidirectional flow. Utility Model Content

[0004] The purpose of this invention includes, for example, providing a valve core assembly and an electronic expansion valve that can reduce the difficulty of opening the valve and make the valve opening smoother; and can also accommodate bidirectional flow and be used flexibly.

[0005] The embodiments of this utility model can be implemented as follows:

[0006] In a first aspect, this utility model provides a valve core assembly, including a valve seat, a valve port, a valve needle, and a seal, wherein:

[0007] The valve seat is provided with a positioning hole; the valve port is provided with a connecting assembly hole, a side hole, and an end hole, the valve port is installed on the valve seat, and the assembly hole communicates with the positioning hole; the valve needle is provided with a balance hole, the valve needle is slidably inserted into the positioning hole and the assembly hole, one end of the balance hole communicates with the positioning hole; the sealing element is sleeved on the valve needle and contacts the hole wall of the positioning hole, the sealing element is located on the side of the valve port closer to the valve seat;

[0008] The valve needle has a first position and a second position that can be switched between each other. When it is in the first position, the side hole and the end hole are connected. When it is in the second position, the side hole and the end hole are blocked by the valve needle, and the other end of the balance hole is connected to the end hole.

[0009] In an optional embodiment, the positioning hole includes a first hole segment and a second hole segment connected together, the diameter of the first hole segment being larger than the diameter of the second hole segment, and the hole walls of the first hole segment and the second hole segment being connected by a first stepped surface; the valve needle includes a first shaft segment and a second shaft segment connected together, the outer diameter of the first shaft segment being larger than the outer diameter of the second shaft segment, and the outer diameter of the first shaft segment being larger than the diameter of the second hole segment; the balance hole passes through both the first shaft segment and the second shaft segment; the first shaft segment passes through the first hole segment, and the first stepped surface is used to restrict the first shaft segment from entering the second hole segment; the second shaft segment passes through the second hole segment, and the second shaft segment is used to block the side hole and the end hole.

[0010] In an optional embodiment, the positioning hole further includes a third hole segment communicating with the second hole segment, the diameter of the second hole segment being smaller than the diameter of the third hole segment, and the hole wall of the second hole segment being connected to the hole wall of the third hole segment through a second stepped surface; the sealing element is disposed in the third hole segment and contacts the second stepped surface.

[0011] In an optional embodiment, a portion of the valve port is inserted into the third hole segment, and the seal is located between the second stepped surface and the valve port.

[0012] In an optional embodiment, a vent hole is provided on the wall of the balance hole, and the two ends of the vent hole are respectively connected to the balance hole and the first hole segment.

[0013] In an optional embodiment, the number of vent holes is multiple, and the multiple vent holes are evenly spaced around the axis of the balance hole.

[0014] In an optional embodiment, the valve needle has a proximal end face and a distal end face, and the two ends of the balance hole pass through the proximal end face and the distal end face respectively, and the distal end face is set as a tapered surface; when the valve needle is in the second position, a portion of the distal end face is inserted into the end hole, and the distal end face is in sealing contact with the edge of the end hole.

[0015] In an optional embodiment, the number of side holes is multiple, and the multiple side holes are arranged at intervals around the axis of the mounting hole.

[0016] Secondly, this utility model provides an electronic expansion valve, the electronic expansion valve comprising:

[0017] The valve core assembly described in any of the foregoing embodiments.

[0018] In an optional embodiment, the electronic expansion valve further includes a drive mechanism mounted on the valve seat and connected to the valve needle for driving the valve needle to reciprocate linearly relative to the positioning hole.

[0019] The beneficial effects of this utility model embodiment include, for example:

[0020] In summary, the valve core assembly provided in this embodiment is illustrated using the side hole as the inlet and the end hole as the outlet. When the valve needle is in the position blocking both the side hole and the end hole, the side hole is connected to the water source and belongs to the high-pressure side, while the end hole is connected to the water outlet and belongs to the low-pressure side. Because a seal is provided between the valve needle and the positioning hole, water from the high-pressure side entering the side hole is blocked by the seal and will not enter the positioning hole. That is, the side hole and the positioning hole are not interconnected, and high pressure will not form inside the valve core assembly, preventing the high-pressure side pressure from pressing the valve needle tightly against the end hole. Because a balance hole is provided inside the valve needle, with its two ends connected to the end hole and the positioning hole respectively, the pressure environment at both ends of the valve needle is basically the same. The two ends of the valve needle are mainly affected by low pressure, resulting in a small pressure difference. When the valve needle moves from closed to open, the pressure difference force that needs to be overcome is small, leading to smooth opening. Meanwhile, when the side hole is used as the outlet and the end hole as the inlet, under the action of the balance hole, the water on the high-pressure side enters the positioning hole from the balance hole and fills the internal space of the valve core assembly. The pressure difference between the two ends of the valve needle is small, and the valve needle is not easily pushed open by the pressure on the high-pressure side. It can realize flexible switching of flow direction and has a wide range of applications. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the valve core assembly according to an embodiment of this application;

[0023] Figure 2 This is a cross-sectional schematic diagram of the valve core assembly according to an embodiment of this application;

[0024] Figure 3 This is an exploded view of the valve core assembly according to an embodiment of this application;

[0025] Figure 4 This is a cross-sectional view of the valve core assembly in an exploded state according to an embodiment of this application;

[0026] Figure 5 This is a cross-sectional schematic diagram of a portion of the structure of the electronic expansion valve according to an embodiment of this application.

[0027] icon:

[0028] 100-Valve seat; 101-First side; 102-Second side; 110-Positioning hole; 111-First hole section; 112-Second hole section; 113-Third hole section; 120-First stepped surface; 130-Second stepped surface; 200-Valve port; 201-Assembly hole; 202-Side hole; 203-End hole; 210-Boss; 300-Valve needle; 301-Balance hole; 302-Ventilation hole; 310-First shaft section; 320-Second shaft section; 330-Annular abutment surface; 340-Conical surface; 400-Seal; 500-Drive mechanism; 510-Lead screw body; 520-Nut; 600-Bearing; 700-Force transmission spring. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0033] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0034] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0035] In the existing technology, taking the side hole 202 as the inlet and the end hole 203 as the outlet as an example, the side hole 202 is connected to the water source and is the high-pressure side. The end hole 203 is connected to the outlet pipe and is the low-pressure side. When the valve needle 300 descends and closes the end hole 203, both the side hole 202 and the end hole 203 are blocked. The high-pressure side pressure acts on the part of the valve needle 300 located in the side hole 202, and the bottom of the valve needle 300 is the low-pressure side. Furthermore, since the valve needle 300 needs to slide relative to the valve port 200, there is a gap between the valve needle 300 and the valve port 200. The high-pressure side water source enters the top of the valve needle 300 through the gap, forming a high-pressure side at the top of the valve needle 300. The pressure difference between the top and bottom of the valve needle 300 is large, making it difficult to open the valve. Furthermore, if the flow direction is adjusted so that the end hole 203 is the inlet and the side hole 202 is the outlet, the end hole 203 is the high-pressure side, and the bottom of the valve needle 300 is subjected to a large high-pressure side pressure, which poses a risk of being opened, and the flow direction adjustment is inconvenient.

[0036] In view of this, the designers have provided a valve core assembly that can reduce pressure differential, improve the smoothness of valve opening, and adjust the flow direction as needed, making it less likely for the valve to fail to close, and has a wide range of applications.

[0037] Please refer to Figures 1-4 This embodiment provides a valve core assembly, including a valve seat 100, a valve port 200, a valve needle 300, and a seal 400. Specifically: the valve seat 100 has a positioning hole 110; the valve port 200 has a communicating assembly hole 201, a side hole 202, and an end hole 203, and is mounted on the valve seat 100, with the assembly hole 201 communicating with the positioning hole 110. The valve needle 300 has a balancing hole 301, and is slidably inserted into the positioning hole 110 and the assembly hole 201, with one end of the balancing hole 301 communicating with the positioning hole 110; the seal 400 is sleeved on the valve needle 300 and contacts the wall of the positioning hole 110, with the seal 400 located on the side of the valve port 200 closest to the valve seat 100. The valve needle 300 has a first position and a second position that can be switched between each other. When it is in the first position, the side hole 202 and the end hole 203 are connected. When it is in the second position, the side hole 202 and the end hole 203 are blocked by the valve needle 300, and the other end of the balance hole 301 is connected to the end hole 203.

[0038] As described above, the working principle of the valve core assembly provided in this embodiment is as follows:

[0039] Taking the side hole 202 as the inlet and the end hole 203 as the outlet as an example, when the valve needle 300 is in the position blocking both the side hole 202 and the end hole 203, the side hole 202 is connected to the water source and belongs to the high-pressure side, while the end hole 203 is connected to the water outlet and belongs to the low-pressure side. Since a seal 400 is provided between the valve needle 300 and the positioning hole 110, water from the high-pressure side entering the side hole 202 is blocked by the seal 400 and will not enter the positioning hole 110. That is, the side hole 202 and the positioning hole 110 are not interconnected, and high pressure will not be formed inside the valve core assembly. There will be no phenomenon where the high-pressure side pressure presses the valve needle 300 tightly against the end hole 203. Because a balance hole 301 is provided inside the valve needle 300, with its two ends connected to the end hole 203 and the positioning hole 110 respectively, the pressure environment at both ends of the valve needle 300 is basically the same. The two ends of the valve needle 300 are mainly affected by low pressure, resulting in a small pressure difference. When the valve needle 300 moves from closed to open, the pressure difference force that needs to be overcome is small, and the opening is smooth. At the same time, when the side hole 202 is used as the outlet and the end hole 203 as the inlet, under the action of the balance hole 301, water from the high-pressure side enters the positioning hole 110 from the balance hole 301, filling the internal space of the valve core assembly. The pressure difference at both ends of the valve needle 300 is small, and the valve needle 300 is not easily pushed open by the pressure of the high-pressure side, enabling flexible switching of flow direction and a wide range of applications.

[0040] The following embodiments illustrate the details of the valve core assembly of this application by way of example.

[0041] Please refer to Figures 1-4 In this embodiment, optionally, the valve seat 100 has a first side 101 and a second side 102 facing each other. A positioning hole 110 is provided on the valve seat 100, penetrating both the first side 101 and the second side 102. The cross-section of the positioning hole 110 can be circular, and the cross-section of the positioning hole 110 is a plane perpendicular to the axis of the positioning hole 110. In the direction from the first side 101 to the second side 102, the positioning hole 110 includes a first hole segment 111, a second hole segment 112, and a third hole segment 113, which are sequentially connected and coaxially arranged. The diameter of the first hole segment 111 is larger than the diameter of the second hole segment 112. The hole walls of the first hole segment 111 and the second hole segment 112 are connected by a first stepped surface 120. The diameter of the second hole segment 112 is smaller than the diameter of the third hole segment 113. The hole walls of the second hole segment 112 and the third hole segment 113 are connected by a second stepped surface 130. Both the first stepped surface 120 and the second stepped surface 130 are annular surfaces.

[0042] By setting the positioning hole 110 of the valve seat 100 to be multi-segmented, the valve needle 300 and the seal 400 can be positioned, which facilitates assembly.

[0043] Please refer to Figure 3In this embodiment, optionally, the valve port 200 can be configured as a cylindrical structure, with a circular boss 210 at one axial end. A mounting hole 201, which is circular, is provided on the end face of the boss 210 and is coaxially arranged with the boss 210. An end hole 203, also circular, is provided at the other axial end of the valve port 200 and is coaxially arranged with the mounting hole 201. Four side holes 202 are provided on the outer circumferential surface of the valve port 200. These four side holes 202 are evenly spaced around the axis of the mounting hole 201. The height of all side holes 202 can be the same, or the heights of adjacent side holes 202 can be different in the circumferential direction, thus making reasonable use of longitudinal space and facilitating the layout of multiple pipes. It should be understood that in other embodiments, the number of side holes 202 can be one or more, as needed.

[0044] During assembly, the boss 210 is inserted into the third hole section 113, and there is a gap between the end face of the boss 210 and the third hole section 113 to form a space for installing the seal 400. In addition, the boss 210 and the third hole section 113 can be interference fit or welded fit to improve the firmness of the joint.

[0045] In this embodiment, it should be understood that the sealing element 400 can be a sealing ring, and the cross-section of the sealing ring can be O-shaped or V-shaped, etc. The sealing ring is embedded in the third hole section 113, and the sealing ring is limited by the boss 210 and the second step surface 130. The position of the sealing ring is stable, not easy to loosen, and has a long service life.

[0046] Please refer to Figure 3 In this embodiment, optionally, the valve needle 300 includes a first shaft segment 310 and a second shaft segment 320 connected together. To improve structural strength, the two can be configured as an integral structure. One end of the first shaft segment 310 is connected to one end of the second shaft segment 320, and the two can be coaxially arranged. Simultaneously, the outer diameter of the first shaft segment 310 is larger than the outer diameter of the second shaft segment 320, and the outer diameter of the first shaft segment 310 is larger than the diameter of the second hole segment 112. A balance hole 301 passes through both the first shaft segment 310 and the second shaft segment 320. The balance hole 301 can be a circular hole, and the diameter of the section of the balance hole 301 located within the first shaft segment 310 is larger than the diameter of the section located within the second shaft segment 320, so as to form an annular abutment surface 330 inside the balance hole 301. A force-transmitting spring 700 for driving the valve needle 300 can be disposed within the hole segment of the first shaft segment 310. The force-transmitting spring 700 contacts the annular abutment surface 330, driving the valve needle 300 to move through elastic force.

[0047] Furthermore, two vent holes 302 are provided on the peripheral wall of the first shaft segment 310. Each vent hole 302 can be a circular hole. The two vent holes 302 are evenly spaced apart in the circumferential direction of the first shaft segment 310, and the two vent holes 302 have the same height. Each vent hole 302 is connected to the balance hole 301. The end face of the second shaft segment 320 away from the first shaft segment 310 can be set as a conical surface 340. Further, the end face of the second shaft segment 320 away from the first shaft segment 310 can be set as a conical surface. The conical surface fits with the edge of the end hole 203 to seal the end hole 203. It should be understood that in the axial direction of the valve needle 300, the end face of the first shaft segment 310 can be the proximal end face, and the end face of the second shaft segment 320 can be the distal end face, with the distal end face set as a conical surface 340.

[0048] Furthermore, the number of vent holes 302 can be one or more. When there are multiple vent holes 302, and the multiple vent holes 302 have the same height and are evenly spaced in the circumferential direction of the valve needle 300, when the water in the balance hole 301 enters the first hole section 111 through the vent holes 302 to make the pressure inside and outside the valve needle 300 the same, the force on the valve needle 300 is balanced, it is not easy to be deflected in the radial direction, the valve needle 300 is not easy to deflect, and the position is stable and reliable.

[0049] During assembly, the first shaft segment 310 passes through the first hole segment 111, and the second shaft segment 320 passes through the second hole segment 112, the third hole segment 113, and the assembly hole 201. The second shaft segment 320 can approach or move away from the end hole 203, thereby sealing the port of the end hole 203 and blocking the side hole 202 and the end hole 203. Furthermore, the end face of the second shaft segment 320 is set as a conical surface, and the conical part can be inserted into the end hole 203. The conical surface contacts the edge of the circular hole of the end hole 203, which is a line contact seal, which can reduce the valve opening pressure difference and facilitate the opening of the valve port 200. When the valve needle 300 slides axially, since the outer diameter of the first shaft section 310 is larger than the diameter of the second hole section 112, when the first shaft section 310 slides toward the second hole section 112 in the first hole section 111, the first step surface 120 can contact the end face of the first shaft section 310 connected to the second shaft section 320, thereby limiting the sliding range of the first shaft section 310 and preventing the first shaft section 310 from entering the second hole section 112.

[0050] The working principle of the valve core assembly provided in this embodiment is as follows:

[0051] Please refer to Figure 2Taking the example of connecting the side hole 202 to the water source and the end hole 203 to the outlet pipe, the following explanation is provided. When the valve needle 300 is in the open state of the end hole 203, the water entering through the side hole 202 enters the end hole 203 and is then discharged. When the valve needle 300 is in the closed state of the end hole 203, both the side hole 202 and the end hole 203 are sealed. The side hole 202 is connected to the water source and is on the high-pressure side. When the high-pressure side water flows from the gap between the valve needle 300 and the valve port 200 to the first orifice section 111, the design of the sealing element 400 prevents the high-pressure side water from entering the first orifice section 111, and the high-pressure side water also does not enter the balance hole 301 from the vent hole 302. Meanwhile, end hole 203 is connected to the outlet pipe, which is the low-pressure side. Water from the low-pressure side enters the balance hole 301 and then enters the first section 111 through the vent hole 302. The pressure in the first section 111 and the balance hole 301 is basically equal. The proximal end face of the valve needle 300 and the distal end face of the valve needle 300 within the end hole 203 are both in a low-pressure environment. The external forces of the two in the axial direction cancel each other out, resulting in a small pressure difference in the axial direction of the valve needle 300. The pressure that needs to be overcome to open the valve is small, which is beneficial for opening the valve. Since there are two vent holes 302 arranged symmetrically, when water in the balance hole 301 enters the first section 111 through the vent hole 302, the thrust of the water on the valve needle 300 is canceled out in the radial direction of the valve needle 300. The valve needle 300 is under balanced force and is not easily deflected.

[0052] Please refer to Figure 5 This embodiment also provides an electronic expansion valve, which includes a drive mechanism 500 and the valve core assembly described above. The drive mechanism 500 is mounted on the valve seat 100 and is connected to the valve needle 300. It is used to drive the valve needle 300 to slide back and forth linearly relative to the positioning hole 110, thereby using the valve needle 300 to close the end hole 203 or open the end hole 203.

[0053] Optionally, the drive mechanism 500 can be configured as a lead screw drive mechanism. The lead screw body 510 of the lead screw drive mechanism can be connected to the first shaft segment 310 of the valve needle 300 via a bearing 600. The inner ring of the bearing 600 is fixedly engaged with the lead screw body 510, while the outer ring can slide relative to the valve needle 300. The upper end of the force transmission spring 700 contacts the lower side of the outer ring. The nut 520 of the lead screw drive mechanism is fixed on the valve seat 100, and the lead screw body 510 is screwed to the nut 520. When the lead screw body 510 rotates, it can slide axially, thereby driving the valve needle 300 to reciprocate linearly via the force transmission spring 700. Since the lead screw body 510 and the valve needle 300 are connected via the bearing 600, the rotation of the lead screw body 510 will not drive the valve needle 300 to rotate, thus avoiding circumferential movement between the valve needle 300 and the valve port 200 and the seal 400, reducing noise.

[0054] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A valve core assembly, characterized in that, Includes a valve seat (100), a valve port (200), a valve needle (300), and a seal (400), wherein: The valve seat (100) is provided with a positioning hole (110); the valve port (200) is provided with a connecting assembly hole (201), a side hole (202) and an end hole (203), the valve port (200) is installed on the valve seat (100), the assembly hole (201) is connected to the positioning hole (110); the valve needle (300) is provided with a balance hole (301), the valve needle (300) is slidably inserted in the positioning hole (110) and the assembly hole (201), one end of the balance hole (301) is connected to the positioning hole (110); the sealing element (400) is sleeved on the valve needle (300) and contacts the hole wall of the positioning hole (110), the sealing element (400) is located on the side of the valve port (200) closer to the valve seat (100); The valve needle (300) has a first position and a second position that can be switched between each other. When it is in the first position, the side hole (202) and the end hole (203) are connected. When it is in the second position, the side hole (202) and the end hole (203) are blocked by the valve needle (300), and the other end of the balance hole (301) is connected to the end hole (203).

2. The valve core assembly according to claim 1, characterized in that: The positioning hole (110) includes a first hole segment (111) and a second hole segment (112) connected together. The diameter of the first hole segment (111) is larger than the diameter of the second hole segment (112). The hole walls of the first hole segment (111) and the second hole segment (112) are connected by a first stepped surface (120). The valve needle (300) includes a first shaft segment (310) and a second shaft segment (320) connected together. The outer diameter of the first shaft segment (310) is larger than the outer diameter of the second shaft segment (320). The outer diameter of the first shaft segment (310) is larger than the diameter of the second hole segment (112); the balance hole (301) passes through both the first shaft segment (310) and the second shaft segment (320); the first shaft segment (310) passes through the first hole segment (111), and the first step surface (120) is used to restrict the first shaft segment (310) from entering the second hole segment (112); the second shaft segment (320) passes through the second hole segment (112), and the second shaft segment (320) is used to block the side hole (202) and the end hole (203).

3. The valve core assembly according to claim 2, characterized in that: The positioning hole (110) further includes a third hole section (113) communicating with the second hole section (112). The diameter of the second hole section (112) is smaller than the diameter of the third hole section (113). The hole wall of the second hole section (112) and the hole wall of the third hole section (113) are connected by a second stepped surface (130). The sealing element (400) is disposed in the third hole section (113) and contacts the second stepped surface (130).

4. The valve core assembly according to claim 3, characterized in that: The valve port (200) is partially inserted into the third hole section (113), and the seal (400) is located between the second step surface (130) and the valve port (200).

5. The valve core assembly according to any one of claims 2-4, characterized in that: The balance hole (301) has a vent hole (302) on its wall, and the two ends of the vent hole (302) are respectively connected to the balance hole (301) and the first hole segment (111).

6. The valve core assembly according to claim 5, characterized in that: The number of vent holes (302) is multiple, and the multiple vent holes (302) are evenly spaced around the axis of the balance hole (301).

7. The valve core assembly according to claim 1, characterized in that: The valve needle (300) has a proximal end face and a distal end face, and the two ends of the balance hole (301) pass through the proximal end face and the distal end face respectively. The distal end face is set as a tapered surface (340). When the valve needle (300) is in the second position, a portion of the distal end face is inserted into the end hole (203), and the distal end face is in sealing contact with the edge of the end hole (203).

8. The valve core assembly according to claim 1, characterized in that: The number of side holes (202) is multiple, and the multiple side holes (202) are arranged at intervals around the axis of the assembly hole (201).

9. An electronic expansion valve, characterized in that, The electronic expansion valve includes: The valve core assembly according to any one of claims 1-8.

10. The electronic expansion valve according to claim 9, characterized in that: The electronic expansion valve also includes a drive mechanism (500), which is mounted on the valve seat (100) and connected to the valve needle (300) for driving the valve needle (300) to reciprocate linearly relative to the positioning hole (110).

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