CN220102105U - Valve assembly and electronic expansion valve - Google Patents

Abstract

The utility model provides a valve assembly and an electronic expansion valve. In this scheme, according to the position difference of annular groove, seal structure has two kinds of different setting positions, and seal structure's inner circle becomes the seal ring line with needle subassembly sealing fit, or seal structure's outer lane becomes the seal ring line with disk seat subassembly sealing fit, in either case, the diameter of seal ring line is less than the maximum diameter of the annular seal portion of needle subassembly and valve port. Through above-mentioned setting, in the position between seal ring line and the annular seal portion, the side of needle subassembly receives the effort of the fluid in the disk seat subassembly towards the valve port, and the effort towards the valve port can be applyed to the valve needle subassembly promptly to the fluid, and the impact force that the tip of valve needle subassembly received when opening the valve like this reduces, has weakened the impact of fluid to the valve needle subassembly tip, improves the stability when opening the valve, has improved the stability of flow variation.

Description

Valve assembly and electronic expansion valve

Technical Field

The utility model relates to the technical field of valve assemblies, in particular to a valve assembly and an electronic expansion valve.

Background

The valve seat assembly of the valve assembly is provided with an opening and closing valve opening through the valve needle assembly which moves back and forth, and under the condition that the valve opening is small in opening degree, high-pressure air flow at the inlet end of the valve assembly cannot be converted into low-pressure air flow at the outlet end in a short time; the high-pressure air flow impacts the end part of the valve needle assembly, so that the valve needle assembly is integrally subjected to a large dynamic air force in a direction away from the valve port, the valve needle assembly is jacked up by the large dynamic air force to enable the valve port to be incapable of being closed, and the whole valve assembly cannot be used continuously. There is a need to optimize existing valve assemblies to address the inability of the valve needle assembly to close the valve port.

Disclosure of Invention

The utility model provides a valve assembly and an electronic expansion valve, which are used for solving the problem that fluid impacts a valve needle assembly when the valve is opened and improving the stability when the valve is opened.

In order to solve the above-described problems, according to an aspect of the present utility model, there is provided a valve assembly including: the valve seat assembly is provided with a valve port at one end; the valve needle assembly is movably arranged in the valve seat assembly to open and close the valve opening, and the contact position of the valve needle assembly and the valve opening forms an annular sealing part of the annular sealing ring; the valve needle assembly is in sealing fit with the valve seat assembly through the sealing structure; the inner wall of the valve seat assembly is provided with an annular groove, the sealing structure is positioned in the annular groove, and the inner diameter of the sealing structure is smaller than the maximum diameter of the annular sealing part of the annular sealing ring; or the outer wall of the valve needle assembly is provided with an annular groove, the sealing structure is positioned in the annular groove, and the outer diameter of the sealing structure is smaller than the maximum diameter of the annular sealing part of the annular sealing ring.

Further, under the condition that the inner wall of the valve seat assembly is provided with the annular groove, the sealing structure comprises a sealing ring and a sealing ring, the sealing ring is arranged around the sealing ring, the valve needle assembly penetrates through the sealing ring, and the sealing ring exerts elastic pretightening force towards the valve needle assembly on the sealing ring.

Further, under the condition that the inner wall of the valve seat assembly is provided with the annular groove, the valve seat assembly comprises a valve cover, a protecting sleeve and a valve core seat which are sequentially connected, the annular groove is arranged between the valve cover and the protecting sleeve, the valve core seat is provided with a valve port, and the valve needle assembly penetrates through the protecting sleeve.

Further, a plurality of flow holes are circumferentially distributed on the valve core seat, and under the condition that the valve port is opened, the valve port is communicated with the plurality of flow holes.

Further, the valve needle assembly comprises a large valve needle, a small valve needle and a soft sealing gasket, the large valve needle is in sealing fit with the valve seat assembly through a sealing structure, the large valve needle is fixedly connected with the small valve needle, the soft sealing gasket is clamped between the large valve needle and the small valve needle, and the soft sealing gasket is in sealing fit with the valve port.

Or the valve seat assembly comprises a valve core seat, a sealing element and a limiting ring, wherein the sealing element is provided with a valve port, the sealing element is positioned in a groove of the valve core seat, the limiting ring is fixed in the groove of the valve core seat, and the limiting ring limits the position of the sealing element.

Further, the valve assembly further comprises a screw rod assembly, a nut assembly and a valve tube, one ends of the screw rod assembly and the valve needle assembly are in driving connection, the nut assembly and the valve tube are fixedly connected with the valve seat assembly, the nut assembly is located in the valve tube, the nut assembly is in threaded connection with the screw rod assembly, the valve assembly further comprises a balance channel, and a cavity between the nut assembly and the valve tube is communicated with the valve port through the balance channel.

Further, the valve needle assembly is provided with a first channel penetrating axially, the screw rod assembly is provided with a second channel, the valve cover and valve seat assembly is internally provided with a third channel, or a gap between the valve cover and valve seat assembly and the screw rod assembly forms the third channel, the nut assembly is provided with a fourth channel, and the first channel, the second channel, the third channel and the fourth channel are sequentially communicated and form a balance channel.

Further, a plurality of flow holes are circumferentially distributed on the valve core seat, and under the condition that the valve port is opened, the valve port is communicated with the plurality of flow holes.

Further, the valve needle assembly comprises a large valve needle, a small valve needle and a sealing gasket, the large valve needle is in sealing fit with the valve seat assembly through a sealing structure, the large valve needle is fixedly connected with the small valve needle, the sealing gasket is clamped between the large valve needle and the small valve needle, and the sealing gasket is in sealing fit with the valve port.

Further, the valve seat assembly comprises a valve core seat, a sealing element and a limiting ring, the sealing element is provided with a valve port, the sealing element is positioned in a groove of the valve core seat, the limiting ring is fixed in the groove of the valve core seat, and the limiting ring limits the position of the sealing element.

According to another aspect of the present utility model, there is provided an electronic expansion valve comprising a mounting seat and the valve assembly described above, a portion of the valve seat assembly of the valve assembly extending into the mounting seat and being fixedly connected thereto.

Further, the outer wall of the valve seat assembly is in threaded connection with the inner wall of the mounting seat, a step structure which is in limit fit with each other is arranged between the mounting seat and the valve seat assembly, the electronic expansion valve further comprises an annular sealing gasket, and the annular sealing gasket is clamped by the step structure between the mounting seat and the valve seat assembly.

By applying the technical scheme of the utility model, the valve assembly comprises: the valve seat assembly, the valve needle assembly and the sealing structure are arranged on the valve seat assembly; the valve needle assembly is movably arranged in the valve seat assembly to open and close the valve opening, and an annular sealing part is formed at the contact position of the valve needle assembly and the valve opening; the valve needle assembly is in sealing fit with the valve seat assembly through the sealing structure; the inner wall of the valve seat assembly is provided with an annular groove, the sealing structure is positioned in the annular groove, and the inner diameter of the sealing structure is smaller than the diameter of the annular sealing part; or the outer wall of the valve needle assembly is provided with an annular groove, the sealing structure is positioned in the annular groove, and the outer diameter of the sealing structure is smaller than the maximum diameter of the annular sealing part. In this scheme, according to the position difference of annular groove, seal structure has two kinds of different setting positions, and seal structure's inner circle becomes the seal ring line with needle subassembly sealing fit, or seal structure's outer lane becomes the seal ring line with disk seat subassembly sealing fit, in either case, the diameter of seal ring line is less than the maximum diameter of the annular seal portion of needle subassembly and valve port. Through the arrangement, the side surface of the valve needle assembly is subjected to the acting force of the fluid in the valve seat assembly towards the valve port at the position between the sealing ring line and the annular sealing part, namely the fluid can apply an acting force towards the valve port to the valve needle assembly, and the acting force can offset a part of the acting force applied by the inlet fluid to the end part of the valve needle assembly, so that the dynamic gas force applied by the valve needle assembly on the whole is reduced, and the valve port can be smoothly closed by the valve needle assembly.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

FIG. 1 shows a schematic structural view of a valve assembly provided in accordance with a first embodiment of the present utility model;

FIG. 2 shows a schematic structural view of a valve assembly according to a second embodiment of the present utility model;

fig. 3 shows a schematic structural diagram of an electronic expansion valve according to a third embodiment of the present utility model.

Wherein the above figures include the following reference numerals:

100. a valve seat assembly; 101. a valve port; 102. a flow hole; 103. an annular groove; 108. an annular seal portion; 110. a valve core seat; 120. a protective sleeve; 130. a valve cover; 150. a seal; 160. a limiting ring; 170. a third channel;

200. a valve needle assembly; 210. a large valve needle; 220. a small valve needle; 230. a sealing gasket; 250. a first channel;

300. a sealing structure; 310. a seal ring; 320. a seal ring;

400. a screw assembly; 410. a second channel; 420. a screw; 430. a bearing; 440. assembling a set; 450. a bushing; 460. a spring;

500. a nut assembly; 510. a fourth channel;

600. a valve tube;

710. a mounting base; 720. an annular gasket.

Detailed Description

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. It will be apparent that the described embodiments are only some, but not all, embodiments of the utility model. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the utility model, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

As shown in fig. 1 to 3, an embodiment of the present utility model provides a valve assembly including: a valve seat assembly 100, one end of the valve seat assembly 100 having a valve port 101; a needle assembly 200 movably disposed within the valve seat assembly 100 to open and close the valve port 101, the needle assembly 200 and the valve port 101 contacting a position to form an annular seal 108; a sealing structure 300 located between the valve seat assembly 100 and the valve needle assembly 200, the valve needle assembly 200 being in sealing engagement with the valve seat assembly 100 by the sealing structure 300; the inner wall of the valve seat assembly 100 has an annular groove 103, the sealing structure 300 is located in the annular groove 103, and the inner diameter of the sealing structure 300 is smaller than the maximum diameter of the annular sealing portion 108, where it should be noted that, the inner diameter of the sealing structure 300 is the inner diameter value of the sealing structure 300 after the valve assembly is installed and after the compression deformation, at this time, the inner diameter of the sealing structure 300 is equal to the outer diameter of the valve needle assembly 200 sealed and attached to the sealing structure 300. Another structure is that the outer wall of the valve needle assembly 200 has an annular groove 103, the sealing structure 300 is located in the annular groove 103, the outer diameter of the sealing structure 300 is smaller than the maximum diameter of the annular sealing portion 108, and it should be noted here that, the outer diameter of the sealing structure 300 is the outer diameter value of the sealing structure 300 after the valve assembly is installed and the outer diameter value of the sealing structure 300 is equal to the inner diameter value of the valve seat assembly 100 sealed and attached with the sealing structure 300.

In this embodiment, there are two different positions of the seal structure 300 according to the positions of the annular groove 103, and the inner ring of the seal structure 300 becomes a seal ring line in sealing engagement with the needle assembly 200, or the outer ring of the seal structure 300 becomes a seal ring line in sealing engagement with the valve seat assembly 100, in either case, the diameter of the seal ring line is smaller than the maximum diameters of the annular seal portions 108 of the needle assembly 200 and the valve port 101. With the above arrangement, at the position between the seal ring line and the annular seal portion 108, the side surface of the needle assembly 200 receives the force of the fluid in the valve seat assembly 100 toward the valve port 101, that is, the fluid applies a force toward the valve port 101 to the needle assembly 200, which counteracts a part of the force applied to the end portion of the needle assembly 200 by the fluid input from the valve port 101, so that the dynamic gas force applied to the whole of the needle assembly 200 is reduced, and smooth closing of the valve port by the needle assembly is ensured.

When the needle assembly 200 is in line contact with the valve port 101, the annular seal 108 is an annular seal line, and the diameter of the annular seal line is the largest diameter. When the valve needle assembly 200 is in surface contact with the valve port 101, the annular sealing portion 108 is an annular sealing surface, and the outer ring of the annular sealing surface is the largest diameter. Where the inner wall of the valve seat assembly 100 has the annular groove 103, the sealing structure 300 includes a seal ring 310 and a seal ring 320, the seal ring 310 is disposed around the seal ring 320, the valve needle assembly 200 passes through the seal ring 320, and the seal ring 310 applies an elastic pre-tightening force to the seal ring 320 toward the valve needle assembly 200. Compared with a single O-shaped ring, the sealing ring 320 and the valve needle assembly 200 have larger interaction force and good sealing effect, and can avoid leakage at a sealing position in a high-temperature environment or after long-term use by elastic pretightening force, so that the reliability of long-term use is ensured.

Wherein, the valve seat assembly 100 comprises a valve cover 130, a protecting sleeve 120 and a valve core seat 110 which are sequentially connected, an annular groove 103 is positioned between the valve cover 130 and the protecting sleeve 120, the valve core seat 110 is provided with a valve port 101, and the valve needle assembly 200 passes through the protecting sleeve 120. The valve seat assembly 100 is provided as a split structure, so that a space for accommodating the sealing structure 300, namely the annular groove 103 is formed conveniently, and the processing difficulty is reduced.

In this scheme, the valve assembly still includes screw rod subassembly 400, nut subassembly 500 and valve pipe 600, and the one end drive connection of screw rod subassembly 400 and needle subassembly 200, nut subassembly 500, valve pipe 600 all are with disk seat subassembly 100 fixed connection, and nut subassembly 500 is located valve pipe 600, nut subassembly 500 and screw rod subassembly 400 threaded connection, and the valve assembly still includes the balance channel, and the cavity between nut subassembly 500 and the valve pipe 600 is through balance channel and valve port 101 intercommunication. Communication between the valve port 101 and the cavity between the nut assembly 500 and the valve tube 600 is achieved through the balancing channel, and fluid pressure in the communicated areas is equal, so that pressure balancing is facilitated, and influence of fluid pressure on the valve port 101 is reduced.

Specifically, as shown in fig. 1 and 2, the needle assembly 200 has a first passage 250 penetrating axially, the screw assembly 400 has a second passage 410, the valve cap 130 has a third passage 170 therein, or the gap between the valve cap 130 and the screw assembly 400 forms the third passage 170, the nut assembly 500 has a fourth passage 510, and the first passage 250, the second passage 410, the third passage 170, and the fourth passage 510 are sequentially communicated and constitute a balance passage. Communication between the valve port 101 and the cavity between the nut assembly 500 and the valve tube 600 is achieved through the multiple passages described above. The specific position and shape of each channel are set according to actual requirements.

The screw assembly 400 comprises a screw 420, a bearing 430, an assembly sleeve 440, a bushing 450 and a spring 460, wherein the screw 420 is in threaded connection with the nut assembly 500, the bearing 430, the bushing 450 and the spring 460 are all positioned in the assembly sleeve 440, the bushing 450 is abutted with the bearing 430, the spring 460 is sleeved on the bushing 450 and is abutted with the valve needle assembly 200, and the assembly sleeve 440 is fixedly connected with the valve needle assembly. Wherein the second channel 410 may be provided on a sidewall of the fitting sleeve 440. The bushing 450 may be configured in a closed configuration that shields the bearing 430 from fluids and contaminants entering the bearing that may affect the life of the bearing 430.

Wherein, a plurality of flow holes 102 are distributed in the circumferential direction of the valve core seat 110, and when the valve port 101 is opened, the valve port 101 is communicated with the plurality of flow holes 102. This enables the switching valve of the valve assembly and the delivery of fluid.

As shown in fig. 1, the valve needle assembly 200 includes a large valve needle 210, a small valve needle 220, and a sealing gasket 230, the large valve needle 210 is in sealing engagement with the valve seat assembly 100 via a sealing structure 300, the large valve needle 210 and the small valve needle 220 are fixedly connected, the sealing gasket 230 is sandwiched between the large valve needle 210 and the small valve needle 220, and the sealing gasket 230 is in sealing engagement with the valve port 101. The sealing gasket 230 and the valve port 101 are in sealing fit, so that the reliability of sealing the valve port 101 can be improved, and the gasket 230 is made of an elastic material. The valve needle is provided as a split structure comprising the large valve needle 210 and the small valve needle 220, so that the sealing gasket 230 is convenient to install. Specifically, the outer diameter of the gasket 230 is larger than the outer diameters of the large needle 210 and the small needle 220, so that the sealing effect on the valve port 101 can be sufficiently ensured.

The valve assembly is assembled with the sleeve 120 coaxially disposed with the valve cartridge 110. During use, bearing 430 is slightly oscillated, and bearing 430 may automatically adjust the axis of valve needle assembly 200 such that the axis of valve needle assembly 200 is adjusted to the axis of valve port 101. In addition, the seal 230 and the throttle section at the lower end of the small valve needle 220 within the port 101 also allow for adjustment of the valve needle assembly 200 to adjust the axis of the valve needle assembly 200 to the axis of the port 101 when the valve needle assembly 200 is offset from the axis of the port 101.

In another embodiment, as shown in FIG. 2, the valve seat assembly 100 includes a valve cartridge seat 110, a seal 150 having a valve port 101, the seal 150 being positioned within a recess of the valve cartridge seat 110, and a stop ring 160 secured within the recess of the valve cartridge seat 110, the stop ring 160 defining the position of the seal 150. The seal 150 is secured by a stop collar 160 to prevent the seal 150 from backing out of the groove. The stop collar 160 may be connected to the inner wall of the groove by welding or interference. In this embodiment, no gasket may be provided in the valve needle assembly 200, and the valve needle assembly 200 may be of unitary construction to effect sealing of the valve port 101 through cooperation with the seal 150.

As shown in FIG. 3, the present utility model also provides an electronic expansion valve comprising a mounting seat 710 and the valve assembly described above, wherein a portion of the valve seat assembly 100 of the valve assembly extends into the mounting seat 710 and is fixedly connected to the mounting seat 710. The electronic expansion valve is suitable for use environments such as vehicles and the like.

Specifically, the outer wall of the valve seat assembly 100 is in threaded connection with the inner wall of the mounting seat 710, a step structure with mutual limit fit is arranged between the mounting seat 710 and the valve seat assembly 100, the electronic expansion valve further comprises an annular sealing gasket 720, and the annular sealing gasket 720 is clamped by the step structure between the mounting seat 710 and the valve seat assembly 100. The annular sealing gasket 720 is elastically deformable in the axial direction, so that the annular sealing gasket 720 can reliably seal the step structure with mutual limit fit between the mounting seat 710 and the valve seat assembly 100, leakage is avoided, sealing is realized in the process of screwing the matched threads, and the assembly is simple and convenient.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present utility model. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present utility model unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present utility model, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present utility model and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present utility model; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present utility model.

Claims (10)

1. A valve assembly, comprising:

a valve seat assembly (100), one end of the valve seat assembly (100) is provided with a valve port (101);

a needle assembly (200) movably disposed in the valve seat assembly (100) to open and close the valve port (101), wherein an annular sealing part (108) is formed at a contact position of the needle assembly (200) and the valve port (101);

a sealing structure (300) located between the valve seat assembly (100) and the valve needle assembly (200), the valve needle assembly (200) being in sealing engagement with the valve seat assembly (100) by the sealing structure (300);

wherein the inner wall of the valve seat assembly (100) is provided with an annular groove (103), the sealing structure (300) is positioned in the annular groove (103), and the inner diameter of the sealing structure (300) is smaller than the maximum diameter of the annular sealing part (108); or the outer wall of the valve needle assembly (200) is provided with an annular groove (103), the sealing structure (300) is positioned in the annular groove (103), and the outer diameter of the sealing structure (300) is smaller than the maximum diameter of the annular sealing part (108).

2. The valve assembly according to claim 1, wherein the sealing structure (300) comprises a sealing ring (310) and a sealing ring (320) in case the inner wall of the valve seat assembly (100) has the annular groove (103), the sealing ring (310) being arranged around the sealing ring (320), the valve needle assembly (200) passing through the sealing ring (320), the sealing ring (310) exerting an elastic pre-tightening force on the sealing ring (320) towards the valve needle assembly (200).

3. The valve assembly according to claim 1, wherein the valve seat assembly (100) comprises a valve cover (130), a protecting sleeve (120) and a valve core seat (110) which are sequentially connected in a case that the annular groove (103) is formed in an inner wall of the valve seat assembly (100), the annular groove (103) is positioned between the valve cover (130) and the protecting sleeve (120), the valve core seat (110) is provided with the valve port (101), and the valve needle assembly (200) passes through the protecting sleeve (120).

4. A valve assembly according to claim 3, further comprising a screw assembly (400), a nut assembly (500) and a valve tube (600), said screw assembly (400) and one end of said valve needle assembly (200) being drivingly connected, said nut assembly (500), said valve tube (600) being fixedly connected to said valve seat assembly (100), and said nut assembly (500) being located within said valve tube (600), said nut assembly (500) and said screw assembly (400) being threadedly connected, said valve assembly further comprising a balancing channel, a cavity between said nut assembly (500) and said valve tube (600) being in communication with said valve port (101) through said balancing channel.

5. The valve assembly of claim 4, wherein the valve needle assembly (200) has a first passage (250) extending axially therethrough, the screw assembly (400) has a second passage (410), the valve cap (130) has a third passage (170) therein, or a gap between the valve cap (130) and the screw assembly (400) forms the third passage (170), the nut assembly (500) has a fourth passage (510), and the first passage (250), the second passage (410), the third passage (170), and the fourth passage (510) are in communication in sequence and constitute the balance passage.

6. A valve assembly according to claim 3, characterized in that the valve cartridge seat (110) is circumferentially distributed with a plurality of flow holes (102), the valve port (101) being in communication with a plurality of the flow holes (102) with the valve port (101) open.

7. The valve assembly of claim 1, wherein the valve needle assembly (200) comprises a large valve needle (210), a small valve needle (220), and a sealing gasket (230), the large valve needle (210) is in sealing engagement with the valve seat assembly (100) by the sealing structure (300), the large valve needle (210) and the small valve needle (220) are fixedly connected, the sealing gasket (230) is sandwiched between the large valve needle (210) and the small valve needle (220), and the sealing gasket (230) is in sealing engagement with the valve port (101).

8. The valve assembly of claim 1, wherein the valve seat assembly (100) includes a valve cartridge seat (110), a seal (150) having the valve port (101), and a stop collar (160), the seal (150) being located within a recess of the valve cartridge seat (110), the stop collar (160) being secured within the recess of the valve cartridge seat (110), the stop collar (160) defining a position of the seal (150).

9. An electronic expansion valve, characterized in that the electronic expansion valve comprises a mounting seat (710) and a valve assembly according to any of claims 1 to 8, a part of the valve seat assembly (100) of the valve assembly extending into the mounting seat (710) and being fixedly connected to the mounting seat (710).

10. The electronic expansion valve of claim 9, wherein the outer wall of the valve seat assembly (100) is threadedly coupled to the inner wall of the mounting seat (710), the mounting seat (710) and the valve seat assembly (100) have a stepped structure therebetween that is in positive engagement with each other, the electronic expansion valve further comprising an annular gasket (720), the annular gasket (720) being clamped by the stepped structure between the mounting seat (710) and the valve seat assembly (100).