Valve assembly and electronic expansion valve

Abstract

A valve assembly is disclosed, comprising a valve seat assembly (100), a valve needle assembly (200), and a sealing structure (300), wherein the valve seat assembly (100) has a valve port (101) at one end, the inner circumference of the sealing structure (300) is a sealing annular line that sealably engages with the valve needle assembly (200), or the outer circumference of the sealing structure (300) is a sealing annular line that sealably engages with the valve seat assembly (100), the diameter of the sealing annular line is smaller than the maximum diameter of the annular seal portion (108) of the valve needle assembly (200) and the valve port (101), and in the position between the sealing annular line and the annular seal portion, the force acting on the side of the valve needle assembly by the fluid inside the valve seat assembly is directed toward the valve port, the fluid exerts a force on the valve needle assembly in the direction of the valve port, thereby reducing the impact force acting on the end of the valve needle assembly when the valve is opened, weakening the impact from the fluid on the end of the valve needle assembly, improving stability when the valve is opened, and improving the stability of flow rate changes. Furthermore, an electronic expansion valve using the valve assembly is disclosed.

Description

Technical Field

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[0003]

[0001] This application claims the priority of the patent application named "Valve Assembly and Electronic Expansion Valve" with the application number 2023104199920, which was filed with the China National Intellectual Property Administration on April 14, 2023, the priority of the patent application named "Valve Assembly and Electronic Expansion Valve" with the application number 2023104207522, which was filed with the China National Intellectual Property Administration on April 14, 2023, the priority of the patent application named "Valve Assembly and Electronic Expansion Valve" with the application number 2023208802679, which was filed with the China National Intellectual Property Administration on April 14, 2023, and the priority of the patent application named "Valve Assembly and Electronic Expansion Valve" with the application number 2023208369201, which was filed with the China National Intellectual Property Administration on April 14, 2023.

[0002] This application relates to the technical field of valve assemblies, specifically to valve assemblies and electronic expansion valves.

Background Art

Summary of the Invention

Problems to be Solved by the Invention

[0004] This application provides a valve assembly and an electronic expansion valve, which solve the problem of impact on the valve needle assembly by fluid during valve opening and improve stability during valve opening. [Means for solving the problem]

[0005] To solve the above problems, according to one aspect of the present application, a valve assembly is provided which includes a valve seat assembly having a valve port at one end; a valve needle assembly movably installed within the valve seat assembly, opening and closing the valve port, with the contact points between the valve needle assembly and the valve port forming an annular sealing portion of an annular seal ring; and a sealing structure located between the valve seat assembly and the valve needle assembly, through which the valve needle assembly engages with the valve seat assembly in a sealed manner, wherein the inner wall of the valve seat assembly is provided with an annular groove, the sealing structure is located within the annular groove, and the inner diameter of the sealing structure is smaller than the maximum diameter of the annular sealing portion of the annular seal ring, or the outer wall of the valve needle assembly is provided with an annular groove, the sealing structure is located within the annular groove, and the outer diameter of the sealing structure is smaller than the maximum diameter of the annular sealing portion of the annular seal ring.

[0006] Furthermore, if the inner wall of the valve seat assembly is provided with an annular groove, the sealing structure includes a seal ring and a seal ring, the seal ring is positioned to surround the seal ring, the valve needle assembly passes through the seal ring, and the seal ring applies an elastic preload force to the seal ring in the direction of the valve needle assembly.

[0007] Furthermore, if the inner wall of the valve seat assembly is provided with an annular groove, the valve seat assembly includes a valve cover, a protective sleeve, and a valve core seat connected in order, the annular groove being located between the valve cover and the protective sleeve, the valve core seat having a valve opening, and the valve needle assembly passing through the protective sleeve.

[0008] Furthermore, multiple flow holes are distributed circumferentially around the valve core seat, and when the valve opening is open, the valve opening communicates with multiple flow holes.

[0009] Furthermore, the valve needle assembly includes a large valve needle, a small valve needle, and a flexible gasket, the large valve needle engages airtightly with the valve seat assembly via a sealing structure, the large valve needle and the small valve needle are fixed together, the flexible gasket is sandwiched between the large and small valve needles, and the flexible gasket engages airtightly with the valve port.

[0010] Alternatively, the valve seat assembly includes a valve core seat, a sealing member, and a position regulating ring, wherein the sealing member has a valve opening, the sealing member is located in a groove of the valve core seat, the position regulating ring is fixed in a groove of the valve core seat, and the position regulating ring regulates the position of the sealing member.

[0011] Furthermore, the valve assembly further includes a screw assembly, a nut assembly, and a valve tube, the screw assembly being movably connected to one end of the valve needle assembly, the nut assembly and the valve tube both being fixed to the valve seat assembly, the nut assembly being located within the valve tube and screwed into the screw assembly, the valve assembly further includes a balance passage, the cavity between the nut assembly and the valve tube communicating with the valve port via the balance passage.

[0012] Furthermore, the valve needle assembly has a first passage that penetrates axially, the screw assembly has a second passage, the valve cover seat assembly has a third passage on the inside, or the gap between the valve cover seat assembly and the screw assembly forms a third passage, and the nut assembly has a fourth passage, and the first passage, second passage, third passage and fourth passage are sequentially connected to form a balance passage.

[0013] Furthermore, multiple flow holes are distributed circumferentially around the valve core seat, and when the valve opening is open, the valve opening communicates with multiple flow holes.

[0014] Furthermore, the valve needle assembly includes a large valve needle, a small valve needle, and a gasket, the large valve needle engages airtightly with the valve seat assembly via a sealing structure, the large valve needle and the small valve needle are fixed together, the gasket is sandwiched between the large and small valve needles, and the gasket engages airtightly with the valve port.

[0015] Furthermore, the valve seat assembly includes a valve core seat, a sealing member, and a position regulating ring, the sealing member having a valve opening, the sealing member being located in a groove of the valve core seat, the position regulating ring being fixed in a groove of the valve core seat, and the position regulating ring regulating the position of the sealing member.

[0016] According to another aspect of this application, an electronic expansion valve is provided, which includes a mounting seat and the valve assembly, wherein a portion of the valve seat assembly of the valve assembly fits into the mounting seat and is fixed to the mounting seat.

[0017] Furthermore, the outer wall of the valve seat assembly and the inner wall of the mounting seat are screwed together, and there is a stepped structure of mutual engagement between the mounting seat and the valve seat assembly, and the electronic expansion valve further includes an annular gasket, which is sandwiched in the stepped structure between the mounting seat and the valve seat assembly.

[0018] Applying the technical solution of this application, a valve assembly is provided which comprises a valve seat assembly, a valve needle assembly and a sealing structure, wherein the valve seat assembly has a valve port at one end, the valve needle assembly is movably installed within the valve seat assembly and opens and closes the valve port, the position where the valve needle assembly and the valve port contact forms an annular seal, the sealing structure is located between the valve seat assembly and the valve needle assembly, and the valve needle assembly engages with the valve seat assembly in a sealed manner via the sealing structure, wherein the inner wall of the valve seat assembly has an annular groove, the sealing structure is located within the annular groove, and the inner diameter of the sealing structure is smaller than the diameter of the annular seal, or the outer wall of the valve needle assembly has an annular groove, the sealing structure is located within the annular groove, and the outer diameter of the sealing structure is smaller than the maximum diameter of the annular seal. In this solution, depending on the position of the annular groove, the sealing structure has two different installation positions, where the inner circumference of the sealing structure becomes a sealing annular line that sealably engages with the valve needle assembly, or where the outer circumference of the sealing structure becomes a sealing annular line that sealably engages with the valve seat assembly. In either case, the diameter of the sealing annular line is smaller than the maximum diameter of the annular seal portion between the valve needle assembly and the valve port. With the above installation, the force of the fluid within the valve seat assembly acting on the side of the valve needle assembly at the position between the sealing annular line and the annular seal portion is directed toward the valve port. That is, the fluid applies a force toward the valve port to the valve needle assembly, and this force cancels out a portion of the force that the fluid at the inlet applies to the end of the valve needle assembly. As a result, the dynamic gas force acting on the entire valve needle assembly is reduced, and the valve port can be smoothly closed by the valve needle assembly.

[0019] The drawings in the specification, which constitute part of this application, are used to enhance the understanding of this application, and the exemplary embodiments and descriptions herein are for interpretive purposes only and do not improperly limit this application. [Brief explanation of the drawing]

[0020] [Figure 1] A schematic diagram of the structure of a valve assembly according to the first embodiment of this application is shown. [Figure 2] A schematic diagram of the partial structure shown in Figure 1 is presented. [Figure 3] Shows a partially enlarged view of FIG. 2. [Figure 4] Shows another schematic view of the partial structure in FIG. 1. [Figure 5] Shows a partially enlarged view of FIG. 4. [Figure 6] Shows a schematic view of the structure of the valve assembly according to the second embodiment of the present application. [Figure 7] Shows a schematic view of the structure of the valve assembly according to the third embodiment of the present application.

Mode for Carrying Out the Invention

[0021] Hereinafter, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. The description of at least one exemplary embodiment below is merely illustrative and is in no way intended to limit the present application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the protection scope of the present application.

[0022] As shown in FIGS. 1 to 6, the first embodiment of the present application provides a valve assembly, which A valve seat assembly 100 having a valve port 101 at one end, A valve needle assembly 200, which is movably installed in the valve seat assembly 100, opens and closes the valve port 101, and the position where the valve needle assembly 200 contacts the valve port 101 forms an annular seal portion 108, and a sealing structure 300, which is located between the valve seat assembly 100 and the valve needle assembly 200, and through which the valve needle assembly 200 is sealingly engaged with the valve seat assembly 100, Here, an annular groove 103 is provided on the inner wall of the valve seat assembly 100, the sealing structure 300 is located within the annular groove 103, and the inner diameter of the sealing structure 300 is smaller than the maximum diameter of the annular seal portion 108. However, it should be noted here that the inner diameter of the sealing structure 300 is the value of the inner diameter of the sealing structure 300 that is compressed and deformed when the valve assembly is installed. In this case, the inner diameter of the sealing structure 300 is equal to the outer diameter of the valve needle assembly 200 that is in sealing contact with the sealing structure 300. As another structure, the valve needle assembly 200 has an annular groove 103 on its outer wall, the sealing structure 300 is located within the annular groove 103, and the outer diameter of the sealing structure 300 is smaller than the maximum diameter of the annular seal portion 108. However, it should be noted here that the outer diameter of the sealing structure 300 is the value of the outer diameter of the sealing structure 300 that is compressed and deformed when the valve assembly is installed, and the outer diameter of the sealing structure 300 is equal to the value of the inner diameter of the valve seat assembly 100 that is in sealing contact with the sealing structure 300.

[0023] When the valve port 101 is in a throttled state with a small opening, it is impossible for the high-pressure airflow flowing into the inlet end of the valve assembly to quickly convert to a low-pressure airflow at the outlet end (valve port 101). As the high-pressure airflow passes through the valve port 101, it collides with the end of the valve needle assembly 200, resulting in a dynamic gas force acting on the entire valve needle assembly 200 in a direction away from the valve port. In this solution, depending on the position of the annular groove 103, the sealing structure 300 has two different installation positions, where the inner circumference of the sealing structure 300 becomes a sealing annular line that sealably engages with the valve needle assembly 200, or where the outer circumference of the sealing structure 300 becomes a sealing annular line that sealably engages with the valve seat assembly 100. In either case, the diameter of the sealing annular line is smaller than the maximum diameter of the annular seal portion 108 of the valve needle assembly 200 and the valve port 101. With the above installation, the fluid force acting on the side of the valve needle assembly 200 at the position between the sealing ring and the annular seal portion 108 is directed toward the valve port 101. In other words, the fluid applies a force toward the valve needle assembly 200 toward the valve port 101, and this force cancels out a portion of the force that the fluid flowing in from the valve port 101 applies to the end of the valve needle assembly 200, which separates it from the valve port 101. As a result, the dynamic gas force acting on the entire valve needle assembly 200 is reduced, enabling smooth closing of the valve port by the valve needle assembly.

[0024] When the valve needle assembly 200 and the valve port 101 are in line contact, the annular seal portion 108 becomes an annular seal line, and the diameter of the annular seal line becomes the maximum diameter. When the valve needle assembly 200 and the valve port 101 are in surface contact, the annular seal portion 108 becomes an annular seal surface, and the outer circumference of the annular seal surface becomes the maximum diameter. Here, if the inner wall of the valve seat assembly 100 is provided with an annular groove 103, the sealing structure 300 includes a seal ring 310 and a seal ring 320, the seal ring 310 is arranged to surround the seal ring 320, the valve needle assembly 200 passes through the seal ring 320, and the seal ring 310 applies an elastic preload force to the seal ring 320 in the direction of the valve needle assembly 200. Compared to using a single O-ring, the interaction force between the seal ring 320 and the valve needle assembly 200 is larger, resulting in a superior sealing effect, and the elastic preload force prevents leakage at the sealed position in high-temperature environments or after long-term use, thus ensuring reliability for long-term use.

[0025] Here, the valve seat assembly 100 includes a valve cover 130, a protective sleeve 120, and a valve core seat 110 connected in sequence, with the annular groove 103 located between the valve cover 130 and the protective sleeve 120, the valve core seat 110 having a valve opening 101, and the valve needle assembly 200 passing through the protective sleeve 120. By making the valve seat assembly 100 a segmented structure, it becomes easier to form the space for accommodating the sealing structure 300, i.e., the annular groove 103, and the difficulty of manufacturing is reduced.

[0026] In this solution, the valve assembly further includes a screw assembly 400, a nut assembly 500, and a valve tube 600, the screw assembly 400 being movably connected to one end of the valve needle assembly 200, the nut assembly 500 and the valve tube 600 both being fixed to the valve seat assembly 100, the nut assembly 500 being located within the valve tube 600 and screwed into the screw assembly 400, the valve assembly further includes a balance passage, the cavity between the nut assembly 500 and the valve tube 600 communicating with the valve port 101 via the balance passage. The balance passage connects the valve port 101 to the cavity between the nut assembly 500 and the valve tube 600, thereby equalizing the fluid pressure in the connected region, facilitating pressure balance, and reducing the influence of fluid pressure on the opening and closing of the valve port 101.

[0027] Specifically, as shown in Figures 1 and 6, the valve needle assembly 200 has a first passage 250 that penetrates axially, the screw assembly 400 has a second passage 410, the valve cover 130 has a third passage 170, or the gap between the valve cover 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 connected to form a balance passage. Through these multiple passages, the valve opening 101 is connected to the cavity between the nut assembly 500 and the valve tube 600. Here, the specific position and shape of each passage are set according to actual requirements.

[0028] Here, the screw assembly 400 includes a screw 420, a bearing 430, an assembly sleeve 440, a bush 450, and a spring 460. The screw 420 is screwed into the nut assembly 500, the bearing 430, the bush 450, and the spring 460 are all located within the assembly sleeve 440, the bush 450 and the bearing 430 are in contact, the spring 460 is fitted onto the bush 450 and in contact with the valve needle assembly 200, and the assembly sleeve 440 and the valve needle assembly are fixed together. Here, the second passage 410 can be provided in the side wall of the assembly sleeve 440. The bush 450 can be provided as a sealed structure, thereby shielding the bearing 430 and preventing fluids and foreign matter from entering the bearing and affecting the bearing's lifespan.

[0029] Here, the valve core seat 110 has multiple flow holes 102 distributed circumferentially, and when the valve opening 101 is open, the valve opening 101 communicates with the multiple flow holes 102. This enables the valve assembly to open and close and to transport fluid.

[0030] As shown in Figure 1, the valve needle assembly 200 includes a large valve needle 210, a small valve needle 220, and a gasket 230. The large valve needle 210 engages airtightly with the valve seat assembly 100 via a sealing structure 300, fixing the large valve needle 210 and the small valve needle 220 together. The gasket 230 is sandwiched between the large valve needle 210 and the small valve needle 220, and the gasket 230 engages airtightly with the valve port 101. By engaging the gasket 230 airtightly with the valve port 101, the sealing reliability of the valve port 101 can be improved, and the gasket 230 is made of an elastic material. By making the valve needle a split structure including a large valve needle 210 and a small valve needle 220, the installation of the gasket 230 becomes easier. Specifically, the outer diameter of the gasket 230 is larger than the outer diameters of the large valve needle 210 and the small valve needle 220, thereby ensuring a sufficient sealing effect on the valve port 101.

[0031] When assembling the valve assembly, it is necessary to ensure that the protective sleeve 120 is positioned coaxially with the valve core seat 110. During use, the bearing 430 may vibrate slightly, and the bearing 430 can automatically adjust the axis of the needle assembly 200 so that its axis aligns with the axis of the valve port 101. In addition, if the valve needle assembly 200 is misaligned with the axis of the valve port 101, the gasket 230 and the throttling segment at the lower end of the small valve needle 220 located inside the valve port 101 can also adjust the valve needle assembly 200 so that its axis aligns with the axis of the valve port 101.

[0032] Specifically, the valve seat assembly 100 includes a valve core seat 110 and a protective sleeve 120, the valve core seat 110 having a valve port 101 at its end and a flow hole 102 in the side wall of the valve core seat 110, the protective sleeve 120 includes a sleeve body 121 which is located within the cavity of the valve core seat 110 and is spaced apart from the inner wall of the valve core seat 110, the outer wall of the sleeve body 121 covers and shields the opening of the flow hole 102, the valve needle assembly 200 is movably inserted through the sleeve body 121 and the valve needle assembly 200 is used to open and close the valve port 101.

[0033] In this solution, a sleeve body 121 is provided inside the valve core seat 110, and the valve needle assembly 200 passes through the sleeve body 121. The outer wall of the sleeve body 121 covers and shields the opening of the flow hole 102, meaning that the sleeve body 121 prevents fluid from flowing in from the flow hole 102. As a result, the fluid does not directly collide with the side of the valve needle assembly 200, avoiding the problem of fluid impacting the valve needle assembly 200 from the side. This prevents unevenness and wear of the valve needle assembly 200 due to lateral fluid impact, ensuring the sealing effect of the valve needle assembly 200 when the valve port 101 is closed and ensuring reliability for long-term use. Here, the valve core seat 110 may be an integral structure or a segmented structure. If the valve core seat 110 is a segmented structure, it may include a valve port and a flow section that are connected to each other. The valve port 101 is provided in the valve port section, the flow hole 102 is provided in the flow section, and the flow section is connected to the protective sleeve 120.

[0034] Of these, the protective sleeve 120 further includes a connector 122, which is connected to the end of the valve core seat 110 away from the valve opening 101, and the end of the sleeve body 121 away from the valve opening 101 is connected to the connector 122. The connector 122 secures the sleeve body 121.

[0035] Specifically, the connector 122 is provided with a first outer annular step 123 on its outside, the side wall of the first outer annular step 123 engages with the inner wall of the valve core seat 110, and the bottom wall of the first outer annular step 123 engages with the end face of the valve core seat 110. The first outer annular step 123 enables axial and radial positioning of the connector 122 and the valve core seat 110, ensuring precise engagement between the connector 122 and the valve core seat 110.

[0036] Furthermore, a flow guide plane 124 is provided at one end of the connector 122 facing the valve port 101, and a flow guide curved surface 125 is provided at the joint between the connector 122 and the sleeve body 121. The flow guide plane 124, the flow guide curved surface 125, and the outer surface of the sleeve body 121 are connected in sequence, and the flow hole 102 is located on the side of the flow guide plane 124 facing the valve port 101. With the above setup, the fluid flowing in from the flow hole 102 is guided by the flow guide plane 124 and the flow guide curved surface 125, changing the direction of the fluid. As a result, the fluid flows along the outer surface of the sleeve body 121, reducing fluid resistance and pressure loss.

[0037] In this embodiment, the valve seat assembly 100 further includes a valve cover 130, the side of the connector 122 away from the valve core seat 110 being connected to the valve cover 130, and an annular groove 103 being provided between the valve cover 130 and the connector 122, or the annular groove 103 being provided within the valve cover 130, or the annular groove 103 being provided within the connector 122, and the valve assembly further includes a sealing structure 300, the sealing structure 300 being located within the annular groove 103 and sealingly engaging with the valve needle assembly 200. The valve cover 130 facilitates connecting the valve assembly to other structures. The sealing structure 300 provides a seal between the valve needle assembly 200 and the valve seat assembly 100.

[0038] Here, the protective sleeve 120 is a single-piece structure, and the engagement portion between the connector 122 and the valve cover 130 must be completely sealed. Specifically, the engagement portion between the connector 122 and the valve cover 130 is connected by continuous welding, thereby ensuring a sealing effect and preventing leakage; that is, it prevents fluid present in the space of the valve cover 130 above the sealing structure 300 from flowing out through the gap between the connector 122 and the valve cover 130. The engagement portion between the connector 122 and the valve core seat 110 is connected by pulse welding or continuous welding. In other embodiments, the protective sleeve 120 can also be a segmented structure.

[0039] Furthermore, the connector 122 is provided with a second outer annular step 126 at the end away from the valve core seat 110 on the outside, the side wall of the second outer annular step 126 engages with the inner wall of the valve cover 130, and the bottom wall of the second outer annular step 126 engages with the end face of the valve cover 130, where the connector 122 is provided with an annular groove 103. The second outer annular step 126 enables axial and radial positioning of the connector 122 and the valve cover 130, ensuring accurate assembly and reliable connection between the protective sleeve 120 and the valve cover 130.

[0040] Here, the seal ring 320 is provided with a projection 321, the projection 321 is provided with a cylindrical engaging surface 322, where the sealing structure 300 is positioned within the valve seat assembly 100, the seal ring 310 is provided so as to surround the seal ring 320, the valve needle assembly 200 passes through the seal ring 320, and the engaging surface 322 engages guidingly and seally with the outer wall of the valve needle assembly 200, or the sealing structure 300 is located within the valve needle assembly 200, the seal ring 320 is provided so as to surround the seal ring 310, and the engaging surface 322 engages guidingly and seally with the inner wall of the valve seat assembly 100.

[0041] In this solution, the projection 321 of the seal ring 320 engages with the outer wall of the valve needle assembly 200 or the inner wall of the valve seat assembly 100 in a guiding and sealing manner, and the seal ring 310 applies an elastic preload force to the seal ring 320. Compared to the case where a single O-ring is used, the interaction force between the seal ring 320 and the valve needle assembly 200 or valve seat assembly 100 is increased, resulting in a superior sealing effect. Furthermore, the elastic preload force prevents leakage at the sealed position in high-temperature environments or after long-term use, ensuring reliability for long-term use. In addition, in this solution, the cylindrical engagement surface 322 on the projection 321 engages with the valve needle assembly 200 or valve seat assembly 100 in a sealing manner, thereby also serving to guide the valve needle assembly 200. Furthermore, in this solution, the axial dimension of the engagement surface 322 is smaller than the axial dimension of the entire seal ring 320. This avoids excessive resistance to valve operation due to an excessively large contact area between the seal ring 320 and the valve needle assembly 200 or valve seat assembly 100, thereby ensuring smooth valve operation of the valve assembly.

[0042] As shown in Figure 3, the projection 321 is provided with a first tapered surface 323, the smaller diameter end of the first tapered surface 323 is connected to one end of the engagement surface 322, or the projection 321 is provided with an annular first arc surface, the smaller diameter end of the first arc surface is connected to one end of the engagement surface 322. By providing the first tapered surface 323 or the first arc surface, a guiding function is performed during assembly, and the axial dimension of the engagement surface 322 can be reduced.

[0043] The projection 321 further comprises a second tapered surface 324, the smaller diameter end of the second tapered surface 324 being connected to the other end of the engagement surface 322, or the projection 321 comprises an annular second arc surface, the smaller diameter end of the second arc surface being connected to the other end of the engagement surface 322. By providing the second tapered surface 324 or the second arc surface, a guiding function during assembly can be achieved, and the axial dimension of the engagement surface 322 can be reduced.

[0044] Here, the seal ring 320 is made of polytetrafluoroethylene, which gives it relatively high load-bearing capacity and makes it suitable for high-pressure working environments. The seal ring 310 is an O-ring, which gives it high elasticity and allows it to apply an elastic preload force to the seal ring 320. With the above solution, the interaction force between the seal ring 320 and the valve needle assembly 200 or valve seat assembly 100 is increased, resulting in a superior sealing effect, and the elastic preload force prevents leakage at the sealed position in high-temperature environments or after long-term use, thus ensuring reliability for long-term use.

[0045] Here, the valve seat assembly 100 is provided with an annular groove 103, and the sealing structure 300 is located within the annular groove 103, thereby achieving positioning relative to the sealing structure 300.

[0046] Specifically, the valve seat assembly 100 includes a first part and a second part, the first part and the second part are fixed together, the annular groove 103 is located between the first part and the second part, and the second part includes a valve opening 101. By making the valve seat assembly 100 a segmented structure, the formation of the annular groove 103 becomes easier and the difficulty of machining is reduced.

[0047] Specifically, the first part includes a valve cover 130 and an annular shielding plate 140, the valve cover 130 having a first inner annular step 132, the annular shielding plate 140 being fixed within the first inner annular step 132, the annular groove 103 being located between the annular shielding plate 140 and the second part, the annular shielding plate 140 and the sealing structure 300 engaging by positioning, the valve needle assembly 200 passing through the annular shielding plate 140 and fixing the valve cover 130 and the second part. By fixing the annular shielding plate 140 within the first inner annular step 132, axial positioning of both is achieved, and the annular shielding plate 140 can axially position the sealing structure 300 and prevent the sealing structure 300 from detaching from the annular groove 103.

[0048] As shown in Figure 1, the second part includes a protective sleeve 120 and a valve core seat 110. The protective sleeve 120 has a second inner annular step 127, and an annular groove 103 is located between the second inner annular step 127 and the first part. The protective sleeve 120 and the first part are fixed together, and the valve core seat 110 and the protective sleeve 120 are fixed together. The valve core seat 110 has a valve opening 101, and a flow hole 102 is provided in the side wall of the valve core seat 110. The valve opening 101 communicates with the flow hole 102 when open. The second inner annular step 127 enables precise positioning and reliable connection between the protective sleeve 120 and the valve core seat 110. By making the second part a split structure, the difficulty of processing can be reduced.

[0049] In this solution, an annular mounting groove 240 is provided between the large valve needle 210 and the small valve needle 220, the large valve needle 210 and the small valve needle 220 are engaged by axial positioning, limiting the axial dimension of the mounting groove 240, the sealing gasket 230 is located within the mounting groove 240 and is used to open and close the valve port 101. In this solution, the large valve needle 210 and the small valve needle 220 are connected and engaged by axial positioning, thereby precisely limiting the axial dimension of the mounting groove 240, limiting the axial dimension of the gasket 230 installed within the mounting groove 240, preventing excessive compression of the gasket 230, and ensuring the sealing effect of the gasket 230 to the valve port 101.

[0050] Of these, the small valve needle 220 includes a first shaft segment 221, a second shaft segment 222, and a third shaft segment 223 that are connected in sequence, with the diameters of the first shaft segment 221, the second shaft segment 222, and the third shaft segment 223 decreasing in sequence. The third shaft segment 223 is inserted into the large valve needle 210, and the end face of the second shaft segment 222 abuts against the end face of the large valve needle 210 to perform axial positioning. A mounting groove 240 is formed by being surrounded by the end face of the large valve needle 210, the end face of the first shaft segment 221, and the outer circumferential surface of the second shaft segment 222, and a gasket 230 is sandwiched between the end face of the large valve needle 210 and the end face of the first shaft segment 221. In this way, by giving the small valve needle 220 a stepped structure and bringing the end face of the second shaft segment 222 into contact with the end face of the large valve needle 210, precise axial positioning of the small valve needle 220 and the large valve needle 210 is achieved. As a result, the axial dimension of the mounting groove 240 formed between the small valve needle 220 and the large valve needle 210 is fixed, and excessive compression of the gasket 230 during assembly or use is prevented.

[0051] As shown in Figure 5, the outer wall of the gasket 230 is provided with a sealing surface 231, which is positioned at an inclination with respect to the axis of the valve port 101, and is used to engage airtightly with the valve port 101. As a result, when it comes into contact with the valve port 101, the contact area is large, thus ensuring the reliability of the seal. The sealing surface 231 may be an inclined surface or an arc surface.

[0052] Specifically, the sealing surface 231 is a tapered surface, and the end of the valve opening 101 has an arc-shaped surface 105, so that the sealing surface 231 and the arc-shaped surface 105 engage in a sealed manner. As a result, when the sealing surface 231 and the arc-shaped surface 105 come into contact, the contact area is large, thus ensuring the reliability of the seal.

[0053] Of these, the outer wall of the gasket 230 is further provided with a cylindrical surface 232, which is located on the side of the sealing surface 231 away from the valve opening 101, and the outer diameter of the cylindrical surface 232 is larger than the outer diameter of the large valve needle 210. As a result, the gasket 230 has a relatively large overall radial dimension and has a better sealing effect compared to a gasket whose outer diameter is smaller than the outer diameter of the large valve needle 210.

[0054] As shown in Figure 5, the small valve needle 220 is equipped with a first axial segment 221. When the valve opening 101 is closed, the first axial segment 221 is inserted into the valve opening 101. Here, the first axial segment 221 is equipped with a tapered flow rate adjustment surface 224, and there is a gap between the flow rate adjustment surface 224 and the inner wall of the valve opening 101. With this setup, during the valve opening process, the flow area between the flow rate adjustment surface 224 and the inner wall of the valve opening 101 gradually changes, thereby providing a flow rate adjustment effect. The specific shape of the first axial segment 221 can be set according to the requirements of the flow rate curve.

[0055] Furthermore, the inner wall of the valve port 101 is provided with a straight cylindrical surface 106 and a guide surface 107. When the valve port 101 is closed, the first shaft segment 221 is inserted into the area enclosed by the straight cylindrical surface 106, the guide surface 107 is a tapered or curved surface, the guide surface 107 is located on the side of the straight cylindrical surface 106 away from the valve needle assembly 200, and the small diameter end of the guide surface 107 is connected to the straight cylindrical surface 106. By providing the guide surface 107, the fluid can be guided and the resistance when it flows into the valve port 101 can be reduced.

[0056] As shown in Figure 4, the large valve needle 210 includes a sequentially connected first connecting segment 211, a transition segment 212, and a second connecting segment 213. The outer diameter of the first connecting segment 211 is smaller than the outer diameter of the second connecting segment 213, and the outer circumferential surface of the transition segment 212 is tapered or curved. The second connecting segment 213 and the small valve needle 220 are inserted and connected, and the sealing structure 300 engages with the second connecting segment 213 in a sealed manner. Because the outer circumferential surface of the transition segment 212 is tapered or curved, damage to the sealing structure 300 can be avoided when the large valve needle 210 passes through the sealing structure 300.

[0057] As shown in Figure 6, in another embodiment, a third annular step 131 is provided on the inside of the valve cover 130, and both the connector 122 and the valve core seat 110 are inserted into the third annular step 131, the end face of the connector 122 and the bottom wall of the third annular step 131 engage by positioning, and the side surface of the connector 122 and the side surface of the valve core seat 110 both engage with the side wall of the third annular step 131 by positioning, and here the valve cover 130 is provided with an annular groove 103. In this structure, a secure connection of the valve cover 130, protective sleeve 120 and valve core seat 110 can be achieved in the same way.

[0058] As shown in Figure 6, in another embodiment, the valve seat assembly 100 includes a valve core seat 110, a sealing member 150, and a position regulating ring 160, wherein the sealing member 150 has a valve port 101, the sealing member 150 is located in a groove of the valve core seat 110, the position regulating ring 160 is fixed in the groove of the valve core seat 110, and the position regulating ring 160 regulates the position of the sealing member 150. The position regulating ring 160 fixes the sealing member 150 and prevents the sealing member 150 from coming out of the groove. The position regulating ring 160 can be connected to the inner wall of the groove by welding or interference fit. In this embodiment, a gasket does not need to be provided in the valve needle assembly 200, the valve needle assembly 200 can be an integral structure, and the valve port 101 can be sealed by engagement with the sealing member 150.

[0059] As shown in Figure 6, in another embodiment, the first portion comprises a third annular step 131 and a fourth annular step 133 arranged in a stepped manner, the third annular step 131 being closer to the valve opening 101 than the fourth annular step 133, the second portion retracting into the third annular step 131 and being fixed to the third annular step 131, and the annular groove 103 being located between the end face of the second portion and the fourth annular step 133. This installation method similarly enables secure connection of the first portion and the second portion and positioning of the sealing structure 300.

[0060] In the above embodiment, there are multiple flow holes 102, the sum of the flow areas of all flow holes 102 is S1, the flow area between the outer surface of the sleeve body 121 and the inner surface of the valve core seat 110 is S2, the flow area between the end of the sleeve body 121 facing the valve opening 101 and the surface where the valve opening 101 is located is S3, and the flow area of ​​the valve opening 101 is S4, where S1≧S4, S2≧S4, and S3≧S4. With the above setup, the flow area of ​​all flow holes 102, the flow area between the outer surface of the sleeve body 121 and the inner surface of the valve core seat 110, and the flow area between the end of the sleeve body 121 facing the valve opening 101 and the surface where the valve opening 101 is located are all larger than the flow area S4 of the valve opening 101, thereby preventing the fluid from being restricted before reaching the valve opening 101.

[0061] In addition, the flow area between the inner surface of the sleeve body 121 and the outer surface of the valve needle assembly 200 is S5, and S5 > 0. As a result, during the upward movement of the valve needle assembly 200, the space between the inner surface of the sleeve body 121 and the outer surface of the valve needle assembly 200 functions as a fluid outlet between the valve needle assembly 200 and the protective sleeve 120.

[0062] In this solution, the connecting body 122 of the protective sleeve 120 may or may not guide the valve needle assembly 200. The lowest end of the sleeve body 121 of the protective sleeve 120 needs to be positioned lower than the position of the flow hole 102, but it is sufficient that it is lower than the position of the flow hole 102 so that the fluid flowing in from the flow hole 102 does not cause a large impact on the valve needle assembly 200. In this solution, it is preferable that the connecting body 122 of the protective sleeve 120 has a non-guiding structure, that is, a predetermined gap is provided between the valve needle assembly 200 and the connecting body 122, and this gap can be used as a spare dimension for mounting the sealing structure 300, and at the same time, even if the valve needle assembly 200 is slightly misaligned from the valve port axis, it is possible to ensure that the protective sleeve 120 does not rub against and damage the sealing surface on the outer surface of the valve needle assembly 200.

[0063] As shown in Figure 7, the present application further 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 fits into the mounting seat 710 and is fixed to the mounting seat 710. The electronic expansion valve is suitable for use in environments such as vehicles.

[0064] Specifically, the outer wall of the valve seat assembly 100 and the inner wall of the mounting seat 710 are screwed together, and a stepped structure is provided between the mounting seat 710 and the valve seat assembly 100 to position them relative to each other. The electronic expansion valve further includes an annular gasket 720, which is sandwiched between the mounting seat 710 and the valve seat assembly 100 by the stepped structure. The annular gasket 720 is elastically deformable in the axial direction, thereby enabling the annular gasket 720 to provide a secure seal to the stepped structure having mutual positioning engagements between the mounting seat 710 and the valve seat assembly 100, preventing leakage, and simplifying assembly as the seal is achieved during the tightening of the engagement screws.

[0065] The foregoing describes preferred embodiments of this application and is not intended to limit it. Those skilled in the art will know that this application is subject to various modifications and changes. Any modifications, equivalent substitutions, improvements, etc., made within the scope of the intent and principles of this application should be included within the scope of protection. [Explanation of Symbols]

[0066] 100 Valve seat assembly, 101 Valve port, 102 Flow hole, 103 Annular groove, 104 Guide sleeve, 105 Curved surface, 106 Straight cylindrical surface, 107 Guiding surface, 108 Annular seal section, 110 Valve core seat, 120 Protective sleeve, 121 Sleeve body, 122 Connecting body, 123 First outer annular step, 124 Flow guide plane, 125 Flow guide curved surface, 126 Second outer annular step, 127 Second inner annular step, 130 Valve cover, 131 Third annular step, 132 First inner annular step, 133 Fourth annular step, 140 Annular shielding plate, 150 Seal member, 160 Position regulating ring, 170 Third passage, 200 Valve needle assembly, 210 Large valve needle, 211 First connection segment, 212 Transition segment, 213 Second connection segment, 220 Small valve needle, 221 First shaft segment, 222 Second shaft segment, 223 Third shaft segment, 224 Flow control surface, 230 Gasket, 231 Sealing surface, 232 Cylindrical surface, 240 Mounting groove, 250 First passage, 300 Sealing structure, 310 Seal ring, 320 Seal ring, 321 Projection, 322 Engaging surface, 323 First tapered surface, 324 Second tapered surface, 400 Screw assembly, 410 Second passage, 420 Screw, 430 Bearing, 440 Assembly sleeve, 450 Bushing, 460 Spring 500 Nut assembly, 510 Fourth passage, 600 valve tubes, 710 Mounting seat, 720 Ring gasket.

Claims

1. A valve seat assembly (100) having a valve port (101) at one end, A valve needle assembly (200) is movably installed within the valve seat assembly (100) so as to open and close the valve port (101), and forms an annular seal portion (108) at the contact position between the valve needle assembly (200) and the valve port (101), A sealing structure (300) is located between the valve seat assembly (100) and the valve needle assembly (200), and the valve needle assembly (200) is sealedly engaged with the valve seat assembly (100) via the sealing structure (300). Equipped with, The valve seat assembly (100) has an annular groove (103) in its inner wall, the sealing structure (300) is located within the annular groove (103), and the inner diameter of the sealing structure (300) is smaller than the maximum diameter of the annular seal portion (108), or the valve needle assembly (200) has an annular groove (103) in its outer wall, the sealing structure (300) is located within the annular groove (103), and the outer diameter of the sealing structure (300) is smaller than the maximum diameter of the annular seal portion (108), Valve assembly.

2. If 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), wherein the seal ring (310) is arranged to surround the seal ring (320), the valve needle assembly (200) passes through the seal ring (320), and the seal ring (310) applies an elastic preload force to the seal ring (320) toward the valve needle assembly (200). If the inner wall of the valve seat assembly (100) has the annular groove (103), the valve seat assembly (100) includes a valve cover (130), a protective sleeve (120), and a valve core seat (110) sequentially connected to the valve seat assembly (100), the annular groove (103) is located between the valve cover (130) and the protective sleeve (120), the valve core seat (110) has the valve opening (101), and the valve needle assembly (200) passes through the protective sleeve (120). The valve assembly according to claim 1.

3. The valve assembly further comprises a screw assembly (400), a nut assembly (500), and a valve tube (600), wherein the screw assembly (400) is movably connected to one end of the valve needle assembly (200), and both the nut assembly (500) and the valve tube (600) are fixed to the valve seat assembly (100), the nut assembly (500) is located within the valve tube (600), and the nut assembly (500) is screwed into the screw assembly (400). The valve assembly further comprises a balance passage, and the cavity between the nut assembly (500) and the valve tube (600) is in communication with the valve opening (101) via the balance passage. The valve assembly according to claim 2.

4. The valve needle assembly (200) has a first passage (250) that penetrates in the axial direction, The screw assembly (400) has a second passage (410), The valve cover (130) has a third passage (170) on its inside, or the gap between the valve cover (130) and the screw assembly (400) forms a third passage (170). The nut assembly (500) has a fourth passage (510), The first passage (250), the second passage (410), the third passage (170), and the fourth passage (510) are connected in sequence to form the balance passage. The valve assembly according to claim 3.

5. The valve needle assembly (200) includes a large valve needle (210), a small valve needle (220), and a gasket (230). The large valve needle (210) is sealedly engaged with the valve seat assembly (100) via the sealing structure (300). The large valve needle (210) and the small valve needle (220) are fixed together. The gasket (230) is sandwiched between the large valve needle (210) and the small valve needle (220). The gasket (230) and the valve opening (101) are engaged in a sealed manner. The valve assembly according to claim 1.

6. The valve seat assembly (100) includes a valve core seat (110), a sealing member (150), and a position regulating ring (160), The sealing member (150) has the valve opening (101), and the sealing member (150) is located in the groove of the valve core seat (110). The position regulating ring (160) is fixed in the groove of the valve core seat (110), and the position regulating ring (160) regulates the position of the sealing member (150). The valve assembly according to claim 1.

7. The valve seat assembly (100) includes a valve core seat (110) and a protective sleeve (120), The valve core seat (110) has the valve opening (101) at its end, The valve core seat (110) has a flow hole (102) in its side wall, The protective sleeve (120) includes a sleeve body (121), The sleeve body (121) is located within the cavity of the valve core seat (110) and is positioned at a distance from the inner wall of the valve core seat (110). The outer wall of the sleeve body (121) covers and shields the opening of the flow hole (102). The valve assembly according to claim 1.

8. The protective sleeve body (120) further includes a connector (122), The connector (122) is connected to the valve core seat (110), The sleeve body (121) is connected to the connector (122), The valve assembly according to claim 7.

9. The valve seat assembly (100) further includes a valve cover (130), The connecting body (122) is connected to the valve cover (130), The valve cover (130) and the connecting body (122) have an annular groove (103), or the valve cover (130) has an annular groove (103) on the inside, or the connecting body (122) has an annular groove (103), The valve assembly further comprises a sealing structure (300), The sealing structure (300) is located within the annular groove (103) and is sealedly engaged with the valve needle assembly (200). The valve assembly according to claim 8.

10. The connecting body (122) has a second outer annular step (126) at the outer end, away from the valve core seat (110), The side wall of the second annular step (126) engages with the inner wall of the valve cover (130), The bottom wall of the second annular step (126) engages with the end face of the valve cover (130). The valve assembly according to claim 9.

11. The valve cover (130) has a third annular step (131) on its inner side. Both the connecting body (122) and the valve core seat (110) are inserted into the third annular step (131). The end face of the connecting body (122) and the bottom wall of the third annular step (131) are engaged in a positional regulating engagement. Both the side surface of the connecting body (122) and the side surface of the valve core seat (110) are engaged with the side wall of the third annular step (131) by positioning. The valve assembly according to claim 9.

12. The flow holes (102) are multiple, the sum of the flow areas of all the flow holes (102) is S1, the flow area between the outer surface of the sleeve body (121) and the inner surface of the valve core seat (110) is S2, the flow area between the end of the sleeve body (121) facing the valve opening (101) and the surface where the valve opening (101) is located is S3, and the flow area of ​​the valve opening (101) is S4, where S1 ≥ S4, S2 ≥ S4, S3 ≥ S4. The flow area between the inner surface of the sleeve body (121) and the outer surface of the valve needle assembly (200) is S5, and S5 > 0. The valve assembly according to claim 7.

13. The sealing structure (300) includes a sealing ring (310) and a sealing ring (320), The sealing ring (320) has a projection (321), The projection (321) has a cylindrical engaging surface (322), The sealing structure (300) is located within the valve seat assembly (100), the seal ring (310) is provided so as to surround the seal ring (320), the valve needle assembly (200) passes through the seal ring (320), and the engaging surface (322) engages guidingly and seally with the outer wall of the valve needle assembly (200), or the sealing structure (300) is located within the valve needle assembly (200), the seal ring (320) is provided so as to surround the seal ring (310), and the engaging surface (322) engages guidingly and seally with the inner wall of the valve seat assembly (100). The valve assembly according to claim 1.

14. The projection (321) has a first tapered surface (323), and the smallest diameter end of the first tapered surface (323) is connected to one end of the engagement surface (322), or the projection (321) has an annular first arc surface, and the smallest diameter end of the first arc surface is connected to one end of the engagement surface (322). The valve assembly according to claim 13.

15. The projection (321) has a second tapered surface (324), and the smaller diameter end of the second tapered surface (324) is connected to the other end of the engaging surface (322), or the projection (321) has an annular second arc surface, and the smaller diameter end of the second arc surface is connected to the other end of the engaging surface (322). The valve assembly according to claim 14.

16. The valve needle assembly (200) includes a large valve needle (210), a small valve needle (220), and a gasket (230). The large valve needle (210) is connected to the small valve needle (220), The large valve needle (210) and the small valve needle (220) have an annular mounting groove (240), The large valve needle (210) and the small valve needle (220) are engaged in the axial direction by positioning, thereby limiting the axial dimension of the mounting groove (240). The gasket (230) is positioned within the mounting groove (240) so as to open and close the valve opening (101). Valve assembly according to claim 1

17. The valve needle (220) includes a first shaft segment (221), a second shaft segment (222), and a third shaft segment (223) sequentially connected to the valve needle (220), The diameters of the first axis segment (221), the second axis segment (222), and the third axis segment (223) decrease in succession. The third axial segment (223) is inserted into the large valve needle (210), To restrict the axial position, the end face of the second axial segment (222) is in contact with the end face of the large valve needle (210), The mounting groove (240) is formed to surround the end face of the large valve needle (210), the end face of the first shaft segment (221), and the outer circumferential surface of the second shaft segment (222). The end face of the large valve needle (210) and the end face of the first shaft segment (221) sandwich the gasket (230). The valve assembly according to claim 16.

18. The aforementioned valve needle (220) has a first axial segment (221), With the valve opening (101) closed, the first shaft segment (221) is inserted into the valve opening (101). The first axial segment (221) has a tapered flow rate adjustment surface (224), A gap is provided between the flow rate adjustment surface (224) and the inner wall of the valve opening (101). The valve assembly according to claim 16.

19. The sealing structure (300) is located within the valve seat assembly (100) and is sealedly engaged with the large valve needle (210). The large valve needle (210) includes a first connection segment (211), a transition segment (212), and a second connection segment (213) that are sequentially connected to the large valve needle (210). The outer diameter of the first connecting segment (211) is smaller than the outer diameter of the second connecting segment (213). The outer surface of the transition segment (212) is a tapered surface or an arc surface. The second connection segment (213) is inserted and connected to the small valve needle (220). The sealing structure (300) is sealedly engaged with the second connecting segment (213). The valve assembly according to claim 16.

20. It is an electronic expansion valve, The electronic expansion valve comprises a mounting seat (710) and a valve assembly according to any one of claims 1 to 19. A portion of the valve seat assembly (100) of the valve assembly is inserted into the mounting seat (710) and fixed to the mounting seat (710). The aforementioned electronic expansion valve further comprises an annular gasket (720), The annular gasket (720) is held in place by a stepped structure between the mounting seat (710) and the valve seat assembly (100). Electronic expansion valve.

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