Electronic expansion valve

Abstract

The electronic expansion valve comprises a limiting seat, a valve seat, a valve needle sleeve, a valve element and a lining, the valve needle sleeve and the valve seat are fixed, and the valve seat is provided with a valve port part; the valve needle sleeve comprises a first cylinder part and a second cylinder part, the limiting seat comprises a third cylinder part at least partially arranged in the first cylinder part, one part of the lining is located in the second cylinder part and is in close fit with the second cylinder part, the other part of the lining is located in the third cylinder part, and the lining, the valve needle sleeve and the limiting seat are coaxially arranged; the valve element is at least partially located in the lining, and the valve element can be in sliding fit with the lining in the axial direction so as to be close to or away from the valve port part. According to the electronic expansion valve, the lining is arranged, at least part of the valve element is located in the lining, and in the process that the valve element moves close to or away from the valve port part, the lining can better guide the valve element to improve the deflection condition in the moving process.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration control, and in particular to an electronic expansion valve. Background Art

[0002] The electronic expansion valve is a refrigerant flow control component for refrigeration and heating equipment, including a valve seat, valve core, nut, screw rod and valve needle sleeve. The valve needle sleeve is fixed to the valve seat, and the screw rod is threaded with the nut. The rotation of the screw rod can drive the nut to move axially through the thread, and the movement of the nut can drive the valve core to move closer to or away from the valve mouth, thereby adjusting the opening size of the valve mouth.

[0003] The valve core is located in the valve needle sleeve and can move axially relative to the valve needle sleeve. For those skilled in the art, how to better guide the valve core and improve the deflection during the movement is a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The purpose of this application is to provide an electronic expansion valve that can better guide the valve core and improve the deflection during the movement process.

[0005] In order to solve the above technical problems, the present application provides an electronic expansion valve, comprising a limit seat, a valve seat, a valve needle sleeve, a valve core and a bushing, wherein the valve needle sleeve is fixed to the valve seat, and the valve seat is provided with a valve port portion;

[0006] The valve needle sleeve includes a first cylindrical portion and a second cylindrical portion, the limiting seat includes a third cylindrical portion at least partially disposed in the first cylindrical portion, a portion of the bushing is located in the second cylindrical portion and tightly matched with the second cylindrical portion, and the other portion is located in the third cylindrical portion, and the bushing, the valve needle sleeve and the limiting seat are coaxially arranged;

[0007] The valve core is at least partially located in the bushing, and the valve core can be slidably matched with the bushing along the axial direction to approach or move away from the valve port.

[0008] The stopper, valve needle sleeve, and bushing are coaxially arranged. The valve core is located within the bushing and can slide axially with the bushing to move closer to or away from the valve opening and adjust the size of the valve opening. During this process, the valve core moves within the bushing and slides with it. This way, the bushing can provide guidance for the valve core's movement. The bushing also provides stable guidance throughout the entire movement of the valve core, ensuring the stability of the valve core's movement and preventing the valve core from swinging during movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a cross-sectional view of the electronic expansion valve provided in an embodiment of the present application in a closed state;

[0010] Figure 2 is Figure 1 is an enlarged view of A in

[0011] Figure 3 is Figure 1 is a sectional view of the electronic expansion valve of

[0012] Figure 4 is a sectional view of the electronic expansion valve in the open valve state according to an embodiment of the present application;

[0013] Figure 5 is Figure 4 is a sectional view of the electronic expansion valve of

[0014] Figure 6 is a structural schematic view of the electronic expansion valve in the installed state of the limit seat, the valve needle sleeve and the bushing;

[0015] Figure 7 and Figure 8 is Figure 6 is a structural schematic view of the valve needle sleeve in

[0016] Figure 9 is Figure 6 is a structural schematic view of the limit seat in

[0017] Figure 10-13 is Figure 6 is a structural schematic view of the bushing in

[0018] Figure 14 is a structural schematic view of the first assembly;

[0019] Figure 15 is a structural schematic view of the second assembly.

[0020] In Figures 1-15 in the drawings, the following reference signs are used:

[0021] 1 valve seat, 11 valve port portion;

[0022] 2 valve core, 21 limit member;

[0023] 3 limit seat, 31 third cylindrical portion, 32 limit groove;

[0024] 4 valve needle sleeve, 41 first cylindrical portion, 42 second cylindrical portion, 43 positioning groove, 44 step surface;

[0025] 5 bushing, 51 opening groove, 52 protrusion portion;

[0026] 6 nut, 61 wing portion;

[0027] 7 screw rod;

[0028] 8 housing;

[0029] 9 rotor;

[0030] 10 bearings. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] The embodiment of the present application provides an electronic expansion valve, such as Figures 1-5 As shown, the electronic expansion valve includes a valve seat 1 and a valve core 2 , wherein the valve seat 1 is provided with a valve opening portion, and the valve core 2 is used to open and close the valve opening portion 11 .

[0033] like Figures 1-5 As shown, the electronic expansion valve also includes a housing 8 and a rotor 9, a limit seat 3, a screw rod 7 and a nut 6 arranged in the housing 8, wherein the screw rod 7 is fixedly connected to the rotor 9, and the screw rod 7 is also threadedly matched with the nut 6, and the nut 6 is connected to the valve core 2. The rotor 9 drives the screw rod 7 to rotate under the driving action of the external coil. The rotation of the screw rod 7 drives the nut 6 to move axially along the screw rod 7 through the thread, thereby driving the valve core 2 to move axially and approach or move away from the valve mouth 11 to adjust the opening of the valve mouth 11, thereby adjusting the flow rate.

[0034] The screw rod 7 is connected to the limit seat 3 through a bearing 10. The inner ring of the bearing 10 is fixedly connected to the screw rod 7, and the outer ring of the bearing 10 is fixedly connected to the limit seat 3. In this way, through the setting of the bearing 10, the limit seat 3 can provide support for the screw rod 7, and due to the load-bearing of the limit seat 3 and the bearing 10, the axial displacement of the screw rod 7 is limited.

[0035] The valve core 2 is a cylindrical structure and is provided with a sealing portion for cooperating with the valve mouth 11. The nut 6 is partially located in the cylindrical structure. Figure 2 As shown, the valve core 2 is also provided with a stopper 21 to prevent the nut 6 from disengaging from the valve core 2. Disengagement, as described herein, means that the two components are no longer restricted in their relative positions, not simply that they are no longer physically in contact. In other words, the nut 6 is connected to the valve core 2 via the stopper 21, and direct contact between the nut 6 and the valve core 2 is possible or not.

[0036] The electronic expansion valve further comprises a valve needle sleeve 4 and a bushing 5, wherein the valve needle sleeve 4 is fixed to the valve seat 1, and the valve needle sleeve 4 comprises a first barrel portion 41 and a second barrel portion 42 (such as Figure 7 and Figure 8 As shown in FIG), the limiting seat 3 includes a third cylindrical portion 31 (as Figure 9 As shown), the third barrel portion 31 is at least partially installed in the first barrel portion 41, as shown Figure 6As shown, one part of the bushing 5 is located in the second cylinder portion 42 and tightly fits with the second cylinder portion 42, and the other part is located in the third cylinder portion 31, and the first cylinder portion 41, the second cylinder portion 42, the third cylinder portion 31 and the bushing 5 are coaxially fixed, that is, the limit seat 3, the valve needle sleeve 4 and the bushing 5 are coaxially arranged.

[0037] The valve core 2 is at least partially located in the bushing 5 and can be axially slidably fitted with the bushing 5 to approach or move away from the valve port portion 11 and adjust the opening size of the valve port portion 11 (specifically, the opening size of the valve port portion 11 is adjusted by the sealing portion). In this process, the movement of the valve core 2 is located in the bushing 5 and is slidably fitted, and there is a small gap between the outer wall of the valve core 2 and the inner wall of the bushing 5. In this way, the bushing 5 can guide the movement of the valve core 2 to ensure the stability of the movement of the valve core 2, avoid the deflection of the valve core 2 during movement, reduce the wear caused by the deflection of the valve core 2, thereby prolonging the service life of the valve core 2 and reducing the cost. At the same time, it can also avoid the situation that the action voltage becomes larger or even stuck due to the deflection of the valve core 2.

[0038] The length of the bushing 5 can be greater than the length of the guide section of the valve core 2, as shown in Figure 3 As shown, when the valve core 2 moves relative to the bushing 5 to cooperate with the valve port portion 11, the length of the outer wall of the guide section in the axial small gap fit with the bushing 5 is L1, as shown in Figure 5 As shown, when the valve core 2 moves relative to the bushing 5 to completely separate from the valve port portion, the length of the outer wall of the guide section in the axial small gap fit with the bushing 5 is L2. Since the valve core 2 completely moves in the bushing 5, L1=L2, and the bushing 5 can provide stable guidance to the movement of the valve core 2 throughout the movement, thereby ensuring the stability of the movement of the valve core 2. Alternatively, the length of the bushing 5 can be equal to the length of the guide section. Compared with the scheme that the length of the bushing 5 is less than the length of the guide section, it can ensure the guiding length of the guide section and the bushing 5 at any position, thereby ensuring the stability of the guiding effect.

[0039] As shown in Figure 9 The third cylinder portion 31 of the limit seat 3 is further provided with a limit groove 32, the opening of the limit groove 32 is arranged towards one side of the valve seat 1, and the outer wall of the nut 6 further extends radially outwardly and is provided with a wing portion 61, the wing portion 61 can pass through the valve core 2 and the bushing 5 in sequence and limit fit with the limit groove 32 (as shown in Figure 2 In order to ensure the stability of the limit and avoid the deflection, the nut 6 can be provided with two radially symmetrical wing portions 61, or four circumferentially uniformly spaced wing portions 61.

[0040] In the embodiment, the specific structure of the limiting member 21 is not limited, the side wall of the valve core 2 is provided with a groove structure, the wing part 61 passes through the side wall of the valve core 2 from the groove structure, and the limiting member 21 blocks the groove structure, which can limit the nut 6 from being separated from the valve core 2.

[0041] As shown in Figure 10-13 , the bushing 5 is provided with an open groove 51, the wing part 61 passes through the open groove 51 and is limited by the limiting groove 32, and the wing part 61 can move axially in the open groove 51. Specifically, as shown in Figure 10 and Figure 12 , the bushing 5 is provided with a pair of open grooves 51, and as shown in Figure 11 and Figure 13 , the bushing 5 is provided with two pairs of open grooves 51, each pair of open grooves 51 includes two radially symmetrical open grooves 51. The number of open grooves 51 can be set according to the number of wing parts 61 of the nut 6.

[0042] As shown in Figure 12 and Figure 13 , the groove bottom of the open groove 51 is provided with a flanging structure outwardly along the radial direction of the bushing 5, the flanging structure forms a protruding part 52, and the second cylinder part 42 is provided with a positioning groove 43 (as shown in Figure 8 ) on one side end thereof facing the first cylinder part 41. After the bushing 5 is fixed with the second cylinder part 42, the protruding part 52 can be positioned and matched with the positioning groove 43, so that the installation of the bushing 5 is facilitated, and it is ensured that the wing part 61 of the nut 6 can pass through the open groove 51 provided in the bushing 5 after the installation of the bushing 5.

[0043] As shown in Figure 8 , the inner diameter of the second cylinder part 42 is smaller than that of the first cylinder part 41, and a step surface 44 is formed between the two, and the positioning groove 43 is arranged on the step surface 44.

[0044] Of course, in the embodiment, the protruding part 52 can also be arranged on the outer wall of the bushing 5 in other ways, such as welding a protruding block on the outer wall of the bushing 5, and the like, which is not limited herein. When the protruding part 52 is formed by the flanging structure, the overall structure and the processing technology can be simplified.

[0045] In the embodiment, the specific fixing mode of the bushing 5 is not limited, and the bushing 5, the valve needle sleeve 4 and the limiting seat 3 are coaxially fixed. The fixing mode of the bushing 5 is described in detail below.

[0046] The first fixing mode: a part of the bushing 5 is tightly matched with the second cylinder part 42, and the third cylinder part 31 is tightly matched with the first cylinder part 41. During installation, the bushing 5 is press-fitted into the second cylinder part 42 of the valve needle sleeve 4, the fixation between the bushing 5 and the valve needle sleeve 4 is realized, and the coaxiality of the bushing 5 and the valve needle sleeve 4 is ensured, and the structure is as shown in Figure 14The first assembly is shown in the figure, and then the first assembly is installed with the limiting seat 3. Specifically, the third barrel portion 31 is pressed into the first barrel portion 41 to fix the limiting seat 3 and the valve needle sleeve 4 and ensure the coaxiality of the limiting seat 3 and the valve needle sleeve 4. At the same time, the other part of the bushing 5 is in small gap fit with the third barrel portion 31, so that the bushing 5 is not deformed when the third barrel portion 31 is pressed into the first barrel portion 41, and the guiding effect of the bushing 5 on the valve core 2 is ensured.

[0047] The second fixing mode is that a part of the bushing 5 is in close fit with the second barrel portion 42, and the third barrel portion 31 is in small gap fit with the first barrel portion 41, and the third barrel portion 31 is also in small gap fit with the other part of the bushing 5. Specifically, during installation, the bushing 5 is first pressed into the second barrel portion 42 to fix the bushing 5 and the valve needle sleeve 4 and ensure the coaxiality of the bushing 5 and the valve needle sleeve 4, and the second assembly as shown in the figure is obtained. Figure 14 The first assembly is shown in the figure, and then the first assembly is installed with the limiting seat 3. Specifically, the third barrel portion 31 is loosely inserted into the first barrel portion 41, and the coaxiality is ensured through a tool, and then the limiting seat 3 and the valve needle sleeve 4 are welded and fixed. The specific welding mode is not limited. For example, the gap between the third barrel portion 31 and the first barrel portion 41 is at least partially filled with welding material, or the third barrel portion 31 and the first barrel portion 41 are fixed by laser fusion welding, the gap between the third barrel portion 31 and the other part of the bushing 5 is at least partially filled with welding material, or the third barrel portion 31 and the other part of the bushing 5 are fixed by laser fusion welding.

[0048] Since the third barrel portion 31 is in small gap fit with the bushing 5, the bushing 5 is not deformed when the third barrel portion 31 is pressed into the first barrel portion 41, and the guiding effect of the bushing 5 on the valve core 2 is ensured.

[0049] The third fixing mode is that the third barrel portion 31 is in close fit with the other part of the bushing 5, and the third barrel portion 31 is in close fit with the first barrel portion 41. During installation, the bushing 5 is first pressed into the third barrel portion 31 to fix the bushing 5 and the limiting seat 3 and ensure the coaxiality of the bushing 5 and the limiting seat 3, and the second assembly as shown in the figure is obtained. Figure 15 The first assembly is shown in the figure, and then the first assembly is installed with the limiting seat 3. Specifically, the third barrel portion 31 is pressed into the first barrel portion 41 to fix the limiting seat 3 and the valve needle sleeve 4 and ensure the coaxiality of the limiting seat 3 and the valve needle sleeve 4. At the same time, the other part of the bushing 5 is in small gap fit with the third barrel portion 31, so that the bushing 5 is not deformed when the third barrel portion 31 is pressed into the first barrel portion 41, and the guiding effect of the bushing 5 on the valve core 2 is ensured.

[0050] The fourth fixing method: the third cylinder 31 is tightly fitted with the other part of the bushing 5, and the first cylinder 41 and the third cylinder 31 are fitted with a small gap, and the second cylinder 42 and a part of the bushing 5 are also fitted with a small gap. Specifically, during installation, the bushing 5 is first pressed into the third cylinder 31 to achieve the fixation between the bushing 5 and the limit seat 3, and ensure the coaxiality of the bushing 5 and the limit seat 3, so as to obtain the following: Figure 15 The second component shown is then installed with the valve needle sleeve 4. Specifically, the third barrel 31 is loosely inserted into the first barrel 41, and after ensuring coaxiality through tooling, the limit seat 3 and the valve needle sleeve 4 are welded and fixed. The specific welding method is not limited. For example, the gap between the first barrel 41 and the third barrel 31 is at least partially filled with solder, or the first barrel 41 and the third barrel 31 are fixed by laser melting welding, and the gap between the second barrel 42 and a part of the bushing 5 is at least partially filled with solder, or the second barrel 42 and a part of the bushing 5 are fixed by laser melting welding. Since the bushing 5 and the second barrel 42 are clearance-fitted, when the third barrel 31 is pressed into the first barrel 41, the bushing 5 will not be deformed, thereby ensuring the guiding effect of the bushing 5 on the valve core 2.

[0051] The fifth fixing method: There is a clearance fit between the bushing 5 and the second cylinder 42, and there is also a clearance fit between the bushing 5 and the third cylinder 31. During installation, the bushing 5 is partially inserted into the second cylinder 42, and after ensuring the coaxiality through the tooling, the bushing 5 and the limit seat 3 are fixed by welding to obtain the following Figure 14 The first component is then installed with the limiting seat 3, specifically, the third barrel 31 is inserted into the first barrel 41 and fixed.

[0052] The sixth fixing method: There is a clearance fit between the bushing 5 and the second cylinder 42, and there is also a clearance fit between the bushing 5 and the third cylinder 31. During installation, the bushing 5 is first inserted into the third cylinder 31, and after ensuring the coaxiality through the tooling, the bushing 5 and the valve needle sleeve 4 are fixed by welding to obtain the following Figure 15 The second assembly is then assembled with the valve needle sleeve 4 , specifically by inserting the third barrel portion 31 into the first barrel portion 41 and fixing it.

[0053] In the above-mentioned fifth fixing method and sixth fixing method, if the first cylinder portion 41 and the third cylinder portion 31 are tightly fitted, the third cylinder portion 31 can be pressed into the first cylinder portion 41 during installation. If the first cylinder portion 41 and the third cylinder portion 31 are clearance fitted, the third cylinder portion 31 can be inserted into the first cylinder portion 41 during installation, and after ensuring the coaxiality through tooling, the limit seat 3 and the valve needle sleeve 4 can be welded and fixed.

[0054] And, in the fifth and sixth fixing modes, the welding between the bushing 5 and the second cylinder portion 42 and the welding between the bushing 5 and the third cylinder portion 31 are not limited, and a predetermined gap is provided between the bushing 5 and the second cylinder portion 42 and between the bushing 5 and the third cylinder portion 31, respectively, wherein the predetermined gap between the bushing 5 and the second cylinder portion 42 is at least partially filled with solder, or the bushing 5 and the second cylinder portion 42 are fused and fixed by laser welding, the predetermined gap between the bushing 5 and the third cylinder portion 31 is at least partially filled with solder, or the bushing 5 and the third cylinder portion 31 are fused and fixed by laser welding. The welding mode is flexible, and can be selected according to actual conditions.

[0055] The first to sixth fixing modes described above can all achieve coaxial fixing of the bushing 5, the limiting seat 3 and the valve needle sleeve 4. The two components in tight fit can be fixed and assembled by press fitting while ensuring coaxiality, and the two components in clearance fit are convenient to install and can reduce the machining precision requirement. A suitable fixing mode can be selected according to actual conditions.

[0056] The above is only a preferred embodiment of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. An electronic expansion valve characterized by, The valve needle sleeve is fixed with the valve seat, the valve seat is provided with a valve port part; The valve needle sleeve includes a first cylinder part and a second cylinder part, the limiting seat includes a third cylinder part which is at least partially arranged in the first cylinder part, a part of the bushing is located in the second cylinder part and tightly fits with the second cylinder part, another part of the bushing is located in the third cylinder part, and the bushing, the valve needle sleeve and the limiting seat are coaxially arranged; The valve core is at least partially located in the bushing, and the valve core can slide with the bushing in the axial direction to approach or move away from the valve port part.

2. The electronic expansion valve according to claim 1, characterized in that A part of the bushing tightly fits with the second cylinder part, the third cylinder part tightly fits with the first cylinder part, and another part of the bushing clearance fits with the third cylinder part.

3. The electronic expansion valve according to claim 1, wherein A part of the bushing tightly fits with the second cylinder part, and the third cylinder part clearance fits with the first cylinder part and another part of the bushing, and the limiting seat and the valve needle sleeve are welded and fixed.

4. The electronic expansion valve according to claim 1, wherein The third cylinder part tightly fits with another part of the bushing, the third cylinder part tightly fits with the first cylinder part, and a part of the bushing clearance fits with the second cylinder part.

5. The electronic expansion valve according to claim 1, wherein The third cylinder part tightly fits with another part of the bushing, the first cylinder part clearance fits with the third cylinder part, and the second cylinder part clearance fits with a part of the bushing, and the limiting seat and the valve needle sleeve are welded and fixed.

6. The electronic expansion valve according to claim 1, wherein The bushing and the second cylinder part have a preset gap, and the bushing and the third cylinder part have a preset gap.

7. The electronic expansion valve according to claim 1, wherein The bushing and the second cylinder part are fixed by laser welding, or the bushing and the third cylinder part are fixed by laser welding.

8. Electronic expansion valve according to any of claims 1-7, characterized in that The nut is connected with the valve core, the nut is threadedly connected with the screw rod, rotation of the screw rod can drive the nut to move in the axial direction through thread transmission, the nut can drive the valve core to move in the bushing to approach or move away from the valve port part. The side wall of the third cylinder part is provided with a limiting groove, the bushing is also provided with an open groove, the outer wall of the nut extends radially outward to form a wing part, the wing part passes through the side wall of the valve core and the open groove and fits with the limiting groove to limit rotation of the nut relative to the limiting seat.

9. The electronic expansion valve according to claim 8, characterized in that The side wall of the bushing extends radially outward to form a protruding part, the valve needle sleeve is provided with a positioning groove which is matched with the protruding part, and the protruding part is positioned and matched with the positioning groove.

10. The electronic expansion valve according to claim 9, characterized in that The groove bottom of the open groove extends radially outward to form a flanging structure, and the flanging structure forms the protruding part.

11. The electronic expansion valve according to claim 1, wherein The valve core has a guide section, and the length of the bushing is greater than or equal to the length of the guide section.

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