CN107304843A

CN107304843A - Electric expansion valve

Info

Publication number: CN107304843A
Application number: CN201610336590.4A
Authority: CN
Inventors: 王定军
Original assignee: Zhejiang Dunan Artificial Environment Co Ltd
Current assignee: Zhejiang Dunan Artificial Environment Co Ltd
Priority date: 2016-04-18
Filing date: 2016-05-20
Publication date: 2017-10-31

Abstract

The invention provides a kind of electric expansion valve.The electric expansion valve includes：First valve seat；Second valve seat, first end is provided with primary valve；Valve seat core, includes spool bore, and there is the first circulation passage to connect two ends in outside；Horizontal adapter；Vertical joint pipe；Needle, is accordingly set with the spool bore of valve seat core；Nut；Screw rod, is reciprocally screwed onto in nut along the moving direction of needle, and glide direction of the valve needle along valve seat core is moved；Second circulation passage, is arranged on nut, and by the intracavity inter-connection of the inner chamber of the second valve seat and the first valve seat；Primary valve is connected by the first circulation passage when valve seat core opens primary valve with the inner chamber upper end of the second valve seat；Second end of the second valve seat combines to form position limiting structure with the first end of nut, sliding position of the limitation valve seat core in the second valve seat.According to the electric expansion valve of the present invention, the problem of can avoiding impacting needle during refrigerant reverse flow and causing screw deadlocking.

Description

Electric expansion valve

Technical field

The present invention relates to electric expansion valve, the electric expansion valve in the refrigeration systems such as air conditioner, refrigerator is particularly applied to.

Background technology

In air-conditioning market, because its indoor set and outdoor unit are distant, therefore typically can be using two electric expansion valves, and the two electric expansion valves must distinguish check valve in parallel, and the operating efficiency of air-conditioning system could be so improved to greatest extent.

During electric expansion valve works, when refrigerant forward flow, needle can be first turned on, then from the primary valve outflow on small valve seat after the passage on valve seat core.When refrigerant reverse flow, it may appear that refrigerant temporary impact valve seat core, valve seat core is slided in small valve seat, and then impact needle, needle is impacted the cooperation between screw rod and nut, the problem of screw deadlocking may being caused.

In addition, Chinese utility model CN_205064939_U is to invention proposes providing the reference such as valve element side wall runner.

The content of the invention

It is an object of the invention to provide a kind of electric expansion valve, the problem of can avoiding impacting needle during refrigerant reverse flow and causing screw deadlocking.

In order to solve the above technical problems, as one aspect of the present invention there is provided a kind of electric expansion valve, including：First valve seat；Second valve seat, is fixedly connected on the first end end of the first valve seat, and the first end end of the second valve seat is provided with primary valve；Valve seat core, is slidably disposed in the second valve seat to open or close primary valve, includes the first circulation passage that connection two ends are provided with the spool bore for being communicated to primary valve, the side wall of the valve seat core；Horizontal adapter, is communicated to the inner chamber of the first valve seat；Vertical joint pipe, is fixedly connected on the outlet port of primary valve；Needle, is accordingly set with the spool bore of valve seat core；Nut, is arranged in the first valve seat；Screw rod, is reciprocally screwed onto in nut along the moving direction of needle, and glide direction of the valve needle along valve seat core moves to open or close spool bore；Second circulation passage, is arranged on nut, and by the intracavity inter-connection of the inner chamber of the second valve seat and the first valve seat；Primary valve is connected by the first circulation passage when valve seat core opens primary valve with the inner chamber top of the second valve seat；Second end of the second valve seat combines to form position limiting structure with the first end of nut, position of the limitation valve seat core in the second valve seat.

Further, the first end of nut is socketed on the second end of the second valve seat.

Further, the 3rd circulation passage is provided with the side wall of the second valve seat between position limiting structure and the first circulation passage, the 3rd circulation passage is when valve seat core closes primary valve by the inner chamber of the second valve seat and the intracavity inter-connection of the first valve seat.

Further, the second valve seat includes pedestal and the second sleeve being fixedly connected with pedestal, and pedestal is fixedly installed on the first valve seat, and valve seat core is slidably disposed in second sleeve.

Further, nut is socketed on second sleeve, the first end close to second valve seat that is radially arranged in nut of second circulation passage along nut.

Further, the first end end of nut is provided with end bosses, catching step is formed between end bosses and the first end end face of nut, the second end end abutment of second sleeve is on catching step, end bosses are set in second sleeve, and position limiting structure is end bosses.

Further, nut is set in second sleeve, and the first end end in the insertion second sleeve of nut is the position limiting structure of spacing valve seat core.

Further, nut has stepped hole, and second sleeve is set in the large diameter hole of nut, and the internal diameter of the diameter holes of nut is less than the internal diameter of second sleeve, and the step of stepped hole is the position limiting structure of spacing valve seat core.

Further, nut has stepped hole, and second sleeve is set in the large diameter hole of nut, and position limiting structure is the baffle ring between the step for the first end end and stepped hole for being fastened on second sleeve.

Further, when electric expansion valve is reversely operated, when valve seat core opens primary valve, needle opens spool bore.

Further, second valve seat（20）The second end and the nut（70）First end combine to form position limiting structure（23）, limit the valve seat core（30）In second valve seat（20）Interior circumferential and axial position.

Further, the first end of nut is also socketed with the first sleeve, and the first sleeve extends to valve seat core, and needle is slidably disposed in the first sleeve；Second end of the second valve seat combines to form position limiting structure with the first end of the first sleeve, to limit position of the valve seat core in the second valve seat.

Further, the equivalent circulation area of the first circulation passage is more than or equal to primary valve circulation area.

Further, the equivalent circulation area of the second circulation passage is more than or equal to primary valve circulation area.

Further, the first circulation passage, the second circulation passage equivalent circulation area it is roughly equal.

The present invention combines to form position limiting structure between first end of the second end end of the second valve seat with nut; it can form spacing to the axial movement of valve seat core; thus when refrigerant reverse flow; the distance that valve seat core is axially moved when being impacted by refrigerant can be limited by position limiting structure; so that valve seat core only moves preset distance; too big impact will not be caused to needle; so as to be protected to the formation of whole electric expansion valve; the problem of effectively preventing refrigerant reverse flow and cause valve seat core impact needle, and then cause screw deadlocking.In addition, when circumferential spacing, the noise that valve seat core is rotated by flow of fluid formation can be reduced.The electric expansion valve for the early stage that applicant has applied, first circulation passage is in the sleeve wall close to the valve port of the second valve seat, during reverse flow, medium flows to the inner chamber of the first valve seat after directly acutely being turned after being throttled by valve port, noise ratio is larger, just enter the inner chamber of the first valve seat, noise very little after present media is throttled by valve port after direct direction slight change, bubbles burst.

Brief description of the drawings

Fig. 1 diagrammatically illustrates the sectional structure chart of the electric expansion valve according to the first embodiment of the present invention；

Fig. 2 diagrammatically illustrates the sectional structure chart of electric expansion valve according to the second embodiment of the present invention；

Fig. 3 diagrammatically illustrates the sectional structure chart of electric expansion valve according to the third embodiment of the invention；

Fig. 4 diagrammatically illustrates the sectional structure chart of electric expansion valve according to the fourth embodiment of the invention；

Fig. 5 diagrammatically illustrates the sectional structure chart of electric expansion valve according to the fifth embodiment of the invention；

Fig. 6 diagrammatically illustrates the sectional structure chart of split type second valve seat of electric expansion valve according to an embodiment of the invention.

Reference in figure：10th, the first valve seat；20th, the second valve seat；30th, valve seat core；40th, horizontal adapter；50th, vertical joint pipe；60th, needle；70th, nut；80th, screw rod；21st, primary valve；22nd, the first circulation passage；23rd, position limiting structure；24th, pedestal；25th, second sleeve；31st, spool bore；71st, the second circulation passage；72nd, the first sleeve；73rd, large diameter hole；74th, diameter holes；75th, the 3rd circulation passage；76th, end bosses.

Embodiment

Embodiments of the invention are described in detail below, but the multitude of different ways that the present invention can be defined by the claims and cover is implemented.

Fig. 1 to 6 is refer to, embodiments in accordance with the present invention, electric expansion valve includes the first valve seat 10, the second valve seat 20, valve seat core 30, horizontal adapter 40, vertical joint pipe 50, needle 60, nut 70 and screw rod 80.First valve seat 10 has inner chamber, and miscellaneous part is arranged in the first valve seat 10.

Second valve seat 20 is fixedly connected on the first end end of the first valve seat 10, and the first end end of the second valve seat 20 is provided with primary valve 21, and the second end of the second valve seat 20 is provided with sliding channel.Second end end of the second valve seat 20 is provided with opening.

Valve seat core 30 is slidably disposed in the sliding channel of the second valve seat 20 to open or close primary valve 21, valve seat core 30 includes the spool bore 31 for being communicated to primary valve 21, glide direction extension of the spool bore 31 along valve seat core 30, and through whole valve seat core 30, the inner chamber of the second valve seat 20 is connected with primary valve 21.First circulation passage 22 at connection two ends is set on the side wall of valve seat core 30.When valve seat core 30 is located at the position for closing primary valve 21, the inner chamber of the first valve seat 10 is merely able to connect by realizing between spool bore 31 and primary valve 21；When valve seat core 30 is located at the position for opening primary valve 21, primary valve 21 is connected by the first circulation passage 22 with the inner chamber top of the second valve seat 20.

Horizontal adapter 40 is communicated to the inner chamber of the first valve seat 10；Vertical joint pipe 50 is fixedly connected on the outlet port of primary valve 21, and is communicated to by primary valve 21 inner chamber of second valve seat 20.

Needle 60 is accordingly set with the spool bore 31 of valve seat core 30；Nut 70 is arranged in the first valve seat 10；Moving direction of the screw rod 80 along needle 60 is reciprocally screwed onto in nut 70, and glide direction of the valve needle 60 along valve seat core 30 moves to open or close spool bore 31.By adjusting the gap between needle 60 and spool bore 31, Flow-rate adjustment can be played a part of.

Second end of the second valve seat 20 is combined to form position limiting structure 23 with the first end of nut 70, and the position limiting structure 23 is arranged on the sliding path of valve seat core 30, is carried out with the axial direction to valve seat core 30 or circumferential movement spacing.In the present embodiment, the first end of nut 70 is socketed on the second end of the second valve seat 20, and position limiting structure 23 forms the binding site at both.

Electric expansion valve also includes the second circulation passage 71, and second circulation passage 71 is arranged on nut 70, and when valve seat core 30 closes primary valve 21 by the inner chamber of the second valve seat 20 and the intracavity inter-connection of the first valve seat 10.

When refrigerant forward flow, enter the inner chamber of the first valve seat 10 from horizontal adapter 40, now valve seat core 30 is in the position for closing primary valve 21, refrigerant can not enter in primary valve 21 from the inner chamber of the first valve seat 10 via the first circulation passage 22, thus horizontal adapter 40 can not be by being connected between the first circulation passage 22 and vertical joint pipe 50.But because spool bore 31 can also connect the inner chamber of the first valve seat 10 with primary valve 21, therefore refrigerant now can also be from the inner chamber of the first valve seat 10 after the opening at the second end of the second valve seat 20, primary valve 21 is flowed at spool bore 31, subsequently into vertical joint pipe 50, realize connecting for horizontal adapter 40 and vertical joint pipe 50, the Flow-rate adjustment to refrigerant now can be realized by adjusting the position of needle 60 come the aperture of regulating valve core bore 31.

When refrigerant reverse flow, it can enter from vertical joint pipe 50 in primary valve 21, now under the percussion of refrigerant, valve seat core 30 is axially moved to the direction away from primary valve 21, first circulation passage 22 is opened, refrigerant enters the inner chamber of the first valve seat 10 through the first circulation passage 22, is then flowed out through horizontal adapter 40.During valve seat core 30 is axially moved, move to after certain distance, reach the position where position limiting structure 23, due to the barrier effect of position limiting structure 23, it will not continue to axially movable, therefore greater impact will not be caused to needle 60, also avoids to impact the fit structure of nut 70 and screw rod 80 after needle 60 is impacted, and then cause the problem of screw rod 80 is stuck.

In refrigerant reverse flow, because the second circulation passage 71 is arranged on nut 70, and by the intracavity inter-connection of the inner chamber of the second valve seat 20 and the first valve seat 10, when valve seat core 30 opens primary valve 21, the intracavity inter-connection of the second circulation passage of inner chamber 71 of the first valve seat 10 and second valve seat 20 at the back side of valve seat core 30 can be caused, so that the pressure and the pressure of the inner chamber of the first valve seat 10 of the inner chamber of second valve seat 20 at the back side of valve seat core 30 are consistent, it is hereby ensured that release the back pressure suffered by valve seat core 30, valve seat core 30 is set to be moved to extreme position, valve seat core 30 is not in very big oscillator noise.

In addition, in refrigerant reverse flow, the refrigerant pressure of the one end of vertical joint pipe 50 is larger, enter the inner chamber of the first valve seat 10 after the first circulation passage 22 is flowed through, now because the second circulation passage 71 is arranged on nut 70, therefore the position that valve seat core 30 will not be moved to where the second circulation passage 71, also the second circulation passage 71 would not be resulted in blockage, thus refrigerant can enter the inner chamber of the second valve seat 20 from the second circulation passage of inner chamber 71 of the first valve seat 10, so that the refrigerant pressure at the two ends of valve seat core 30 realizes balance, impact forces of the refrigerant to valve seat core 30 can further be reduced, and then reduce impact forces of the refrigerant to needle 60.

Preferably, when electric expansion valve is reversely operated, when valve seat core 30 opens primary valve 21, needle 60 opens spool bore 31, so, because needle 60 opens spool bore 31, therefore the gap outflow that the refrigerant of reverse flow can be between needle 60 and valve seat core 30, the refrigerant of reverse flow can be greatly reduced to the impact forces caused by needle 60, and buffering is formed between valve seat core 30 and needle 60, reduction valve seat core 30 is to the impact forces caused by needle 60.

In order to preferably reduce the percussion that needle 60 is caused to the fit structure of nut 70 and screw rod 80, preferably, buffer structure is additionally provided between needle 60 and screw rod 80, the buffer structure is, for example, spring, after needle 60 is impacted, the formation of the percussion of needle 60 can be buffered by spring first, therefore can further reduce the impact that needle 60 is likely to result in, improve safety and reliability when electric expansion valve is used.

With reference to shown in Figure 1, in one embodiment of the present invention, second valve seat 20 includes pedestal 24 and the second sleeve 25 being fixedly connected with pedestal 24, be formed in one structure between pedestal 24 and second sleeve 25, pedestal 24 is fixedly installed on the first valve seat 10, valve seat core 30 is slidably disposed in second sleeve 25, and connection the first circulation passage of two ends 22 is set on the wall of side.Nut 70 is socketed on second sleeve 25, the first end close to second valve seat 20 that is radially arranged in nut 70 of second circulation passage 71 along nut 70.First circulation passage 22 can be circular hole, or the through hole of other shapes.Preferably, side-wall shaft of multiple first circulation passages 22 along valve seat core 30 is set to uniform intervals.

Second end end abutment of second sleeve 25 is in the first end end of nut 70, the first end end of nut 70 is provided with end bosses 76, catching step is formed between end bosses 76 and the first end end face of nut 70, the external diameter of end bosses 76 is less than the internal diameter of second sleeve 25, end bosses 76 are stretched into second sleeve 25, it is radially spacing to the formation of second sleeve 25, the position limiting structure 23 now formed between the end bosses 76 as valve seat 20 of nut 70 and second, when end bosses 76 are local crownings, rotation stop can be coordinated with the first circulation passage 22.Because the external diameter of the end bosses 76 is less than the internal diameter of second sleeve 25, therefore it can be set in second sleeve 25, and be arranged on the sliding path of valve seat core 30, the position that slides axially of valve seat core 30 is defined, so as to be prevented effectively from the problem of causing greater impact in the motion process of valve seat core 30 to needle 60 and cause screw deadlocking.

With reference to shown in Figure 2, among second embodiment of the present invention, the concrete structure of electric expansion valve and first embodiment are essentially identical, difference is, in the present embodiment, when valve seat core 30 closes primary valve 21, the 3rd circulation passage 75 is provided with the side wall of the second valve seat 20 between the circulation passage 22 of position limiting structure 23 and first, the 3rd circulation passage 75 is when valve seat core 30 closes primary valve 21 by the inner chamber of the second valve seat 20 and the intracavity inter-connection of the first valve seat 10.

In refrigerant forward flow, 3rd circulation passage 75 and the second circulation passage 71 are opened, refrigerant in first valve seat 10 can be flowed into quickly in the second valve seat 20 through the 3rd circulation passage 75 and the second circulation passage 71, then flowed out at primary valve 21, now the 3rd circulation passage 75 can form auxiliary circulation passage so that refrigerant can the more quick inner chamber for being swimmingly circulated to the second valve seat 20.In refrigerant reverse flow, the 3rd circulation passage 75, the second circulation passage 71 and the first circulation passage 22 are opened, and now can adjust the damping size suffered by valve seat core 30 by adjusting the circulation area of the second circulation passage 71.

With reference to shown in Figure 3, according to the 3rd embodiment of the present invention, the difference of itself and one embodiment is, in the present embodiment, the first end of nut 70 be tube-in-tube structure, and the tube-in-tube structure external diameter be less than or equal to the second valve seat 20 second sleeve 25 internal diameter so that the first end of nut 70 can be set in second sleeve 25, and extend in second sleeve 25, the first end end in the insertion second sleeve 25 of nut 70 forms the position limiting structure 23 of spacing valve seat core 30.

In the present embodiment, the entire outer diameter of nut 70 is smaller, the position limiting structure 23 of the axial movement position in second sleeve 25 as spacing valve seat core 30 can partly be stretched into, other transformations need not be carried out to nut 70 again, therefore structure is simpler, processes also more convenient, can reduce manufacturing procedure, processing cost is reduced, processing efficiency is improved.

With reference to shown in Figure 4, according to the 4th embodiment of the present invention, it is essentially identical with one embodiment, difference is that in the present embodiment, the first end end of nut 70 has stepped hole, the second sleeve 25 of second valve seat 20 is set in the large diameter hole 73 of the first end end of nut 70, and be coaxially disposed with nut 70, so as to realize the accurate guiding to screw rod 80, needle 60 and spool bore 31, it is ensured that fluency and reliability that needle 60 is moved.

In the present embodiment, the end abutment of the second sleeve 25 of second valve seat 20 is on the step of the stepped hole of nut 70, because the internal diameter of the diameter holes 74 of nut 70 is less than the internal diameter of second sleeve 25, therefore stepped hole is still formed between the endoporus of second sleeve 25 and the diameter holes 74 of nut 70, the diameter holes of the stepped hole are the diameter holes 74 of nut 70, the large diameter hole of the stepped hole is the internal diameter of second sleeve 25, position limiting structure 23 is by the step that is formed between second sleeve 25 and nut 70, on the sliding path for being located at valve seat core 30 due to the step, and the small-bore of the step is less than the external diameter of valve seat core 30, therefore valve seat core 30 can not continue to be axially moved after the step of the stepped hole is reached, so as to the formation axial limiting of valve seat core 30.

With reference to shown in Figure 5, according to the 5th embodiment of the present invention, it is essentially identical with the 4th embodiment, difference is, in the present embodiment, position limiting structure 23 is the baffle ring being fastened between the step of the stepped hole of the first end end of the second valve seat 20 and nut 70, and baffle ring has lower convexity, can coordinate rotation stop with valve seat core first passage 22.First face of the baffle ring is connected on the first end end face of the second valve seat 20, and the second face is connected on the step surface of stepped hole, and is compressed by the cooperation between the second valve seat 20 and nut 70, and valve seat core 30 realizes the spacing of axial direction by the baffle ring.

Preferably, the first end of nut 70 can also be arranged with the first sleeve 72, and the first sleeve 72 extends to valve seat core 30, and needle 60 is slidably disposed in the first sleeve 72.First set cylinder 72 is arranged in nut 70, nut 70 structure of itself can be simplified, the difficulty of processing of nut 70 is reduced, and also allows for follow-up replacing and maintenance work.For the first end of nut 70 is arranged the structure of the first sleeve 72, the second end of the second valve seat 20 combines to form position limiting structure 23 with the first end of the first sleeve 72, to limit sliding position of the valve seat core 30 in the second valve seat 20.Second end of the second valve seat 20 is similar with the mode that the first end of the first sleeve 72 combines the position limiting structure 23 formed between the position limiting structure 23 to be formed and above-mentioned nut 70 and the second valve seat 20, simply replaces the direct connection relational between the original valve seat 20 of nut 70 and second in order to which nut 70 is by way of the first sleeve 72 and the second valve seat 20 are attached.

With reference to shown in Figure 6, in the present embodiment, second valve seat 20 is also to include pedestal 24 and second sleeve 25, but pedestal 24 and second sleeve 25 are machine-shaping respectively, then it is fixedly connected and is integrally formed, it can be welded as a whole, can also be fixed together by helicitic texture etc. between pedestal 24 and second sleeve 25.

The preferred embodiments of the present invention are the foregoing is only, are not intended to limit the invention, for those skilled in the art, the present invention there can be various modifications and variations.Within the spirit and principles of the invention, any modification, equivalent substitution and improvements made etc., should be included in the scope of the protection.

Claims

1. A kind of electric expansion valve, it is characterised in that including：

First valve seat（10）；

Second valve seat（20）, it is fixedly connected on first valve seat（10）First end end, second valve seat（20）First end end be provided with primary valve（21）；

Valve seat core（30）, it is slidably disposed on second valve seat（20）It is interior to open or close the primary valve（21）, include and be communicated to the primary valve（21）Spool bore（31）, the valve seat core（30）Side wall on be provided with connection two ends the first circulation passage（22）；

Horizontal adapter（40）, it is communicated to first valve seat（10）Inner chamber；

Vertical joint pipe（50）, it is fixedly connected on the primary valve（21）Outlet port；

Needle（60）, with the valve seat core（30）Spool bore（31）Accordingly set；

Nut（70）, it is arranged on first valve seat（10）It is interior；

Screw rod（80）, along the needle（60）Moving direction be reciprocally screwed onto the nut（70）It is interior, drive the needle（60）Along the valve seat core（30）Glide direction movement to open or close the spool bore（31）；

Second circulation passage（71）, it is arranged on the nut（70）On, and by second valve seat（20）Inner chamber and first valve seat（10）Intracavity inter-connection；

First circulation passage（22）In the valve seat core（30）Open the primary valve（21）When by the primary valve（21）It is connected with the inner chamber top of second valve seat；

Second valve seat（20）The second end and the nut（70）First end combine to form position limiting structure（23）, limit the valve seat core（30）In second valve seat（20）Interior position.

2. electric expansion valve according to claim 1, it is characterised in that the nut（70）First end be socketed on second valve seat（20）The second end.

3. electric expansion valve according to claim 1, it is characterised in that the position limiting structure（23）With first circulation passage（22）Between second valve seat（20）The 3rd circulation passage is provided with the wall of side（75）, the 3rd circulation passage（75）In the valve seat core（30）Close the primary valve（21）When by second valve seat（20）Inner chamber and first valve seat（10）Intracavity inter-connection.

4. Electric expansion valve according to claim 1, it is characterised in that second valve seat（20）Including pedestal（24）With with the pedestal（24）The second sleeve being fixedly connected（25）, the pedestal（24）It is fixedly installed on first valve seat（10）On, the valve seat core（30）It is slidably disposed on the second sleeve（25）It is interior.

5. Electric expansion valve according to claim 4, it is characterised in that the nut（70）It is socketed on the second sleeve（25）, second circulation passage（71）Along the nut（70）Be radially arranged in the nut（70）Close second valve seat（20）First end.

6. Electric expansion valve according to claim 5, it is characterised in that the nut（70）First end end be provided with end bosses（76）, the end bosses（76）With the nut（70）First end end face between form catching step, second sleeve（25）The second end end abutment on the catching step, the end bosses（76）It is set in the second sleeve（25）It is interior, the position limiting structure（23）For the end bosses（76）.

7. electric expansion valve according to claim 5, it is characterised in that the nut（70）It is set in the second sleeve（25）It is interior, the nut（70）The insertion second sleeve（25）Interior first end end is the spacing valve seat core（30）The position limiting structure（23）.

8. electric expansion valve according to claim 5, it is characterised in that the nut（70）With stepped hole, the second sleeve（25）It is set in the nut（70）Large diameter hole（73）It is interior, the nut（70）Diameter holes（74）Internal diameter be less than the second sleeve（25）Internal diameter, the step of the stepped hole is the spacing valve seat core（30）The position limiting structure（23）；Or the nut（70）With stepped hole, the second sleeve（25）It is set in the nut（70）Large diameter hole（73）It is interior, the position limiting structure（23）To be fastened on the second sleeve（25）First end end and the stepped hole step between baffle ring.

9. Electric expansion valve according to claim 1, it is characterised in that second valve seat（20）The second end and the nut（70）First end combine to form position limiting structure（23）, limit the valve seat core（30）In second valve seat（20）Interior circumferential and axial position.

10. Electric expansion valve according to any one of claim 1 to 9, it is characterised in that the nut（70）First end be also socketed with the first sleeve（72）, first sleeve（72）To the valve seat core（30）Extension, the needle（60）It is slidably disposed on first sleeve（72）It is interior；Second valve seat（20）The second end and the first sleeve（72）First end combine to form the position limiting structure（23）, to limit the valve seat core（30）In second valve seat（20）Interior position.