CN110296267B

CN110296267B - Electronic expansion valve

Info

Publication number: CN110296267B
Application number: CN201810247873.0A
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2018-03-23
Filing date: 2018-03-23
Publication date: 2021-02-26
Anticipated expiration: 2038-03-23
Also published as: CN110296267A

Abstract

The invention provides an electronic expansion valve, comprising: the valve seat is provided with a valve seat cavity and a valve port; a core assembly, at least a portion of the core assembly being movably disposed in the valve seat cavity; the screw rod is matched with the nut through threads, and the nut is fixedly connected with the core body assembly; the support frame is directly or indirectly fixedly connected with the valve seat, the support frame is provided with a matching groove, the nut is provided with a convex part, and the convex part is matched with the matching groove; actuating mechanism, including rotor and coil, rotor and lead screw fixed connection, the rotor passes through the coil and drives the lead screw rotation, through the screw-thread fit effect with the lead screw and with the cooperation in cooperation groove, the nut can remove and do not carry out circumferential direction along axial direction, the core subassembly passes through the drive of nut and can be close or keep away from the valve port. The technical scheme of the invention can effectively solve the problem of high production cost of the electronic expansion valve in the prior art.

Description

Electronic expansion valve

Technical Field

The invention relates to the technical field of refrigeration control, in particular to an electronic expansion valve.

Background

In the structure of the existing electronic expansion valve, the electronic expansion valve is composed of a driving part (a coil and a rotor) and a flow regulating part (a nut, a screw rod, a shell, a valve needle, a valve seat core, a connecting pipe and the like). The rotor is in driving connection with the screw rod, the nut is fixed on the valve seat and in threaded connection with the screw rod, and the valve needle is fixedly connected with the screw rod. Like this, when the rotor rotated under the external coil drive effect, the rotor can drive the lead screw and rotate along its axis, simultaneously, because lead screw and nut screw-thread fit for the lead screw can also move along its axis when rotatory along its axis. Because the valve needle is fixedly connected with the screw rod, the valve needle can move along the axis of the screw rod under the driving of the screw rod, and therefore the valve port on the valve seat core is opened and closed. Although the above structure can realize the function of adjusting the flow, because the lead screw rotates along the axis thereof and moves along the axis thereof, the above structure can realize the function of adjusting the flow, but because the rotor moves up and down together with the lead screw, and the coil is stationary, along with the descending of the lead screw, the rotor is farther from the coil, the driving force is smaller and smaller, and the required driving force is usually realized by enlarging the volume of the coil and the rotor, thereby increasing the volume of the whole structure of the electronic expansion valve and increasing the manufacturing cost.

Disclosure of Invention

The invention mainly aims to provide an electronic expansion valve, which can reduce the whole volume of the electronic expansion valve and reduce the production cost.

In order to achieve the above object, the present invention provides an electronic expansion valve comprising: the valve seat is provided with a valve seat cavity and a valve port; a core assembly, at least a portion of the core assembly being movably disposed in the valve seat cavity; the screw rod is matched with the nut through threads, and the nut is fixedly connected with the core body assembly; the support frame is directly or indirectly fixedly connected with the valve seat, the support frame is provided with a matching groove, the nut is provided with a convex part, and the convex part is matched with the matching groove; actuating mechanism, including rotor and coil, rotor and lead screw fixed connection, the rotor passes through the coil and drives the lead screw rotation, through the screw-thread fit effect with the lead screw and with the cooperation in cooperation groove, the nut can remove and do not carry out circumferential direction along axial direction, the core subassembly passes through the drive of nut and can be close or keep away from the valve port.

By applying the technical scheme of the invention, the core body component of the electronic expansion valve is fixedly connected with the nut, the nut can drive the core body component to axially lift to be close to or far away from the valve port through the thread matching action of the screw rod and the nut and the matching action of the nut and the support frame, the nut can prevent the nut and the core body component from circumferentially rotating through the matching action of the protrusion part of the nut and the matching groove of the support frame when the electronic expansion valve is actuated, and relative to the nut, the screw rod and the rotor connected with the screw rod only circumferentially rotate together with the screw rod without axially lifting movement, so that the rotor cannot generate relative displacement with the coil in the axial direction. The structure enables the rotor to fully exert the magnetism of the core body assembly no matter the core body assembly is close to the valve port or is far away from the valve port, the driving force is not required to be ensured by increasing the volume of the coil, and therefore the volume of an electronic expansion valve product is reduced, and the production cost is reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic longitudinal sectional view of a first embodiment of an electronic expansion valve according to the present invention;

fig. 2 shows an enlarged schematic view at a of the electronic expansion valve of fig. 1;

fig. 3 is a schematic longitudinal sectional view of the electronic expansion valve of fig. 1, wherein fig. 3 shows dimensions D1, D2, D3, and D4;

fig. 4 is a perspective view illustrating a nut of the electronic expansion valve of fig. 1;

fig. 5 is a schematic perspective view illustrating a support frame of the electronic expansion valve of fig. 1;

fig. 6 is a schematic longitudinal sectional view showing a second embodiment of the electronic expansion valve according to the present invention;

fig. 7 is a schematic perspective view illustrating a supporting frame of the electronic expansion valve of fig. 6;

fig. 8 is a schematic longitudinal sectional view showing a third embodiment of the electronic expansion valve according to the present invention;

fig. 9 is a schematic perspective view illustrating a support frame of the electronic expansion valve of fig. 8; and

fig. 10 is a schematic longitudinal sectional view showing a fourth embodiment of the electronic expansion valve according to the present invention.

Wherein the figures include the following reference numerals:

1. a cavity; 4. a valve seat cavity; 10. a valve seat; 11. a valve seat body; 12. a connecting seat; 121. connecting the socket cavity; 13. a valve port; 14. a first interface; 15. a second interface; 20. a core assembly; 21. a first core segment; 22. a second core segment; 23. a connecting surface; 30. a screw rod; 40. a nut; 41. a nut body portion; 42. a projection; 50. a drive mechanism; 51. a rotor; 52. a coil; 60. a housing; 70. a support frame; 71. a limiting hole section; 72. a mating groove; 73. a pilot hole segment; 74. an upper barrel section; 75. a lower barrel section; 76. a step surface; 90. a support; 110. a first elastic member; 150. an upper baffle ring; 160. a lower baffle ring; 170. a sealing structure; 180. a second elastic member; 190. a speed reduction mechanism; 200. and (5) positioning the shaft.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 to 5, the electronic expansion valve of the first embodiment includes a valve seat 10, a core assembly 20, a lead screw 30, a nut 40, a support bracket 70, and a driving mechanism 50. The valve seat 10 has a valve seat chamber 4 and a valve port 13. At least a portion of the core assembly 20 is movably disposed in the valve seat cavity 4. The screw rod 30 and the nut 40 are matched through threads, and the nut 40 is fixedly connected with the core body assembly 20. The support bracket 70 is directly or indirectly fixedly connected with the valve seat 10, the support bracket 70 is provided with a matching groove 72, the nut 40 is provided with a convex part 42, and the convex part 42 is matched with the matching groove 72. The driving mechanism 50 includes a rotor 51 and a coil 52, the rotor 51 is fixedly connected with the lead screw 30, the rotor 51 drives the lead screw 30 to rotate through the coil 52, the nut 40 can move along the axial direction and does not rotate in the circumferential direction through the screw-thread matching action with the lead screw 30 and the matching groove 72, and the core body assembly 20 can approach or be far away from the valve port 13 through the driving of the nut 40.

According to the technical scheme of the first application embodiment, the core assembly 20 of the electronic expansion valve is fixedly connected with the nut 40, the nut 40 can drive the core assembly 20 to perform axial lifting motion to be close to or far away from the valve port 13 through the screw matching action of the screw rod 30 and the nut 40 and the matching action of the nut 40 and the support frame 70, when the electronic expansion valve is actuated, the nut 40 and the core assembly 20 are prevented from rotating circumferentially through the matching action of the protruding part of the nut 40 and the matching groove 72 of the support frame 70, relative to the nut 40, the screw rod 30 and the rotor 51 connected with the screw rod 30 and the screw rod 30 only perform circumferential rotation and do not perform axial lifting motion, and therefore, the rotor 51 does not generate relative displacement with the coil 52 in the axial direction. The structure enables the rotor 51 to fully exert the magnetism no matter the core body assembly 20 is close to the valve port 13 or far away from the valve port 13, and the driving force is ensured without increasing the volume of the coil 52, so that the volume of the electronic expansion valve product is reduced, and the production cost is reduced.

Specifically, as the screw shaft 30 rotates, the nut 40 threadedly engaged with the screw shaft 30 also has a tendency to rotate, and when the nut 40 rotates, the projection 42 of the nut 40 abuts against the groove wall of the engagement groove 72 to prevent the nut 40 from rotating circumferentially. But the nut 40 can move up and down in its axial direction as the lead screw 30 rotates. The core assembly 20, which is fixedly attached to the nut 40, is thus also capable of axial movement, thereby effecting movement of the core assembly 20 away from or toward the valve port 13.

It should be noted that the nut 40 is fixedly connected to the core assembly 20, and the "fixed connection" means that the nut 40 cannot move in the axial direction of the core assembly 20 relative to the core assembly 20, and cannot rotate relative to the core assembly 20.

It should also be noted that one skilled in the art would know that a mating slot could be provided on the nut and a protrusion on the support that mates with the mating slot as related alternatives.

As shown in fig. 1, in the first embodiment, the valve seat 10 includes a valve seat body 11 and a connecting seat 12, the connecting seat 12 is fixedly connected to the valve seat body 11, the valve port 13 is disposed on the valve seat body 11, the connecting seat 12 has a connecting seat cavity 121, the core assembly 20 is press-fitted into the connecting seat cavity 121, and the support frame 70 is fixedly connected to the valve seat body 11 through the connecting seat 12. The structure is simple, and the assembly and the processing are convenient.

As shown in fig. 1, 2 and 4, in the first embodiment, the nut 40 includes a nut body 41 and a protruding portion 42 disposed on a side wall of the nut body 41 and extending outward, a threaded hole is disposed on the nut body 41, and the lead screw 30 is inserted into the threaded hole. The structure is simple and easy to process.

As shown in fig. 1, 2 and 5, in the first embodiment, the supporting frame 70 is cup-shaped, the supporting frame 70 includes a side wall, the side wall of the supporting frame 70 is fixedly connected to the connecting seat 12, the screw rod 30 penetrates into an inner cavity of the supporting frame 70 along an axial direction of the supporting frame 70, at least a portion of the nut 40 is located in the inner cavity, the side wall is provided with a first opening, the nut 40 is provided with a first protrusion extending into the first opening, the first opening forms a fitting groove 72, and the first protrusion forms the protruding portion 42. When the nut 40 has a tendency to rotate under the drive of the lead screw 30, the mouth wall of the first opening can abut against the side wall of the first projection to prevent the nut 40 with the first projection from continuing to rotate. In this way, the nut 40 can only move in the axial direction in cooperation with the lead screw 30.

As shown in fig. 1 and 5, in the first embodiment, the supporting frame 70 includes an upper cylinder section 74 and a lower cylinder section 75, wherein the outer diameter of the upper cylinder section 74 is smaller than the outer diameter of the lower cylinder section 75, a step surface 76 is formed at the connection position of the upper cylinder section 74 and the lower cylinder section 75, and the first opening is arranged at the bottom of the lower cylinder section 75 and extends upwards. The step surface 76 can support the bottom of the rotor 51.

As shown in fig. 1 and 2, in the first embodiment, the weight of the nut 40 is borne by the core assembly 20, and since the electronic expansion valve generates vibration during operation, the nut 40 may move upward relative to the core assembly 20. In order to solve the above problem, in this embodiment, the supporting frame 70 further includes a top wall, the screw rod 30 is disposed through the top wall and extends into the inner cavity, a first elastic member 110 is disposed between the top wall and the upper surface of the nut 40, and the first elastic member 110 applies a downward force to the nut 40 to prevent the nut 40 from moving upward. In the above structure, the first elastic member 110 can press the nut 40 against the core assembly 20, and noise generated by collision between the nut 40 and the core assembly 20 when the electronic expansion valve vibrates is reduced.

It should be noted that the first projection is engaged with the first opening, so that the nut 40 cannot rotate relative to the core assembly 20, and the first elastic member 110 between the upper surface and the top wall of the nut achieves that the nut 40 cannot move relative to the core assembly 20 in the axial direction thereof. Finally, the purpose of fixedly connecting the nut 40 with the core body assembly 20 is achieved. Of course, one skilled in the art will appreciate that the nut 40 and the core assembly 20 may be joined together by bonding, welding, or the like.

It should be further noted that, the supporting frame 70 can provide an upward force to the rotor 51 during the rotation process of the rotor 51, and on the other hand, the supporting frame realizes the downward pre-tightening of the rotor 51 through the combination of the supporting frame, the first elastic element 110 and the nut 40, so as to reduce the transmission of the rotor 51 and the pulse deviation and flow deviation caused by the crosstalk, improve the flow consistency and stability during the adjustment of the refrigerant, and realize the precise flow adjustment control, and the supporting frame 70 has multiple purposes as a component, so that the structure of the electronic expansion valve is simpler, the assembly is more convenient,

in the prior art, a spring is generally arranged in a core body assembly, and a screw rod can abut against the spring, so that the core body assembly abuts against a valve port under the action of elastic force of the spring to seal the valve port. To enable a greater range of flow regulation over time, the path of the valve port is typically increased. However, as the diameter of the valve port increases, the upward pressure experienced by the core assembly when it is plugged at the valve port also increases. To overcome the pressure, the spring is typically oversized to increase the downward force. Because the volume of the spring is increased, the downward propping force applied by the driving mechanism to the spring is correspondingly increased under the same compression amount, and finally, the volume of the coil is correspondingly increased, so that the volume of the electronic expansion valve is greatly increased, and the cost is greatly improved.

In order to solve the above problem, as shown in fig. 1 to 3, in the first embodiment, a first port 14 and a second port 15 are disposed on a valve seat 10 at intervals, the first port 14 is communicated with a valve port 13, a cavity 1 communicated with the valve port 13 is disposed inside a core assembly 20, and the core assembly 20 is connected with the valve seat 10 in a sealing manner. The above structure allows the first port 14 to penetrate the cavity 1, and when the core assembly 20 is located at the closed position (the position where the core assembly 20 blocks the valve port 13), and the refrigerant enters the cavity 1 from the first port 14, the core assembly 20 is blocked at the valve port 13 by the downward differential pressure and the downward driving force of the driving mechanism 50, and is kept at the closed position. The differential pressure force is formed by the action of the area difference and the pressure. Since the above structure does not require a downward urging force to be applied to the core assembly 20 by the spring, the volume of the spring and the coil does not need to be increased even if the diameter of the valve port 13 is increased.

As shown in fig. 1 to 3, in the first embodiment, the core assembly 20 includes a first core section 21 and a second core section 22, an outer diameter of the second core section 22 is adapted to a cavity wall of the connecting socket cavity 121, and the electronic expansion valve further includes a sealing structure 170 disposed between the connecting socket 12 and the first core section 21 to seal a gap between the connecting socket 12 and the first core section 21. The first core segment 21 is fixedly connected to the nut 40, the bottom end of the second core segment 22 can close the valve port 13, and the outer diameter of the second core segment 22 is larger than that of the first core segment 21. In the above structure, the bottom of the second core segment 22 blocks at the valve port 13 (the outer diameter of the second core segment 22 is larger than the through diameter of the valve port 13 to maintain the seal), and the outer diameter of the first core segment 21 does not affect the sealability of blocking the valve port 13, so the outer diameter of the first core segment 21 is designed freely. Further, it is preferable that the core assembly 20 is composed of a first core segment 21 and a second core segment 22, and the second core segment 22 having a larger outer diameter is fitted to the coupling housing 121, so that the core assembly 20 can be mounted on the valve seat 10 from the top to the bottom.

Preferably, as shown in fig. 1 and 2, in the first embodiment, the connecting seat 12 is provided with an inner hole, a connecting seat cavity 121 is formed in the inner hole, the inner hole is a stepped hole, the stepped hole comprises a receiving hole at an upper portion and a guide hole at a lower portion, and an inner wall of the guide hole is adapted to an outer wall of the second core section 22 so as to enable the core assembly 20 to move in a predetermined direction. An upper retainer ring 150 and a lower retainer ring 160 are arranged on the step surface of the stepped hole, and a sealing structure 170 is clamped between the upper retainer ring 150 and the lower retainer ring 160. The support bracket 70 is supported on the step surface of the stepped hole by the stopper ring.

In the first embodiment, the movement lower stop point of the core assembly 20 may be when the bottom of the core assembly 20 abuts against the valve port 13 (fully closed configuration), or may be when the lower surface of the protrusion 42 abuts against the upper surface of the upper retainer ring 150 (non-fully closed configuration). The upper stop point of the movement of the core assembly 20 may be when the upper surface of the projection 42 abuts against the top wall of the first opening of the support bracket 70, or when the connecting surface 23 connecting the first core segment 21 and the second core segment 22 abuts against the lower surface of the lower retainer ring 160.

As shown in fig. 1, in the first embodiment, the electronic expansion valve further includes a housing 60 covering the upper portion of the valve seat 10, the rotor 51, the lead screw 30, the support bracket 70, and the like are disposed in the housing, a bracket 90 is further disposed in the top of the housing, a first end of the positioning shaft 200 is inserted into the bracket 90, and a second end of the positioning shaft 200 is inserted into the lead screw 30, which can position the lead screw 30, the rotor 51, and the like, and can prevent the lead screw 30 from moving upward.

As shown in fig. 6 and 7, the electronic expansion valve of the second embodiment is different from the electronic expansion valve of the first embodiment in the arrangement position of the elastic member and the structure of the support bracket 70, and specifically, as shown in fig. 6, in the second embodiment, a second elastic member 180 is arranged between the upper surface of the nut and the rotor 51 to support the rotor 51. Specifically, the second elastic member 180 is a spring, the spring is sleeved on the screw rod 30, one end of the spring abuts against the rotor 51, and the other end of the spring abuts against the upper surface of the nut 40. The spring applies an upward urging force to the rotor 51 to support the rotor 51 against downward movement of the rotor 51 along its axis. Since the rotor 51 does not move downward with the nut 40, the relative displacement between the rotor 51 and the coil 52 is greatly reduced, and the maximum rotation speed that the rotor 51 can reach is ensured to be unchanged (the maximum driving force is unchanged). Therefore, the driving force is not required to be ensured by increasing the volume of the coil, so that the product volume is reduced, and the production cost is reduced.

As shown in fig. 6 and 7, in the second embodiment, the supporting frame 70 is ring-shaped, the supporting frame 70 includes a peripheral wall, the peripheral wall of the supporting frame 70 is fixedly connected to the connecting base 12, the peripheral wall is provided with a second opening, the nut 40 is provided with a second protrusion extending into the second opening, the second opening forms a matching groove 72, and the second protrusion forms the protrusion 42. When the nut 40 has a tendency to rotate, the side walls of the projections 42 will abut the groove walls of the mating grooves 72 to prevent rotation of the nut 40. The structure is simple and easy to process.

As shown in fig. 8 and 9, the electronic expansion valve according to the third embodiment is different from the electronic expansion valve according to the second embodiment in the specific structure of the support frame 70. Specifically, in the third embodiment, the support frame 70 is in a cylindrical shape, the side wall of the support frame 70 is fixedly connected with the valve seat 10, the inner hole of the support frame 70 includes a limiting hole section 71 and a guiding hole section 73 located below the limiting hole section 71, the fitting groove 72 is arranged in the limiting hole section 71, the inner diameter of the guiding hole section 73 is matched with the outer diameter of the core body assembly 20, the nut 40 is provided with a third protruding block extending into the fitting groove 72, and the third protruding block forms the protruding portion 42. When the nut 40 has a tendency to rotate, the side wall of the third projection abuts against the groove wall of the fitting groove 72 to prevent the nut 40 from rotating. The structure is simple and easy to process. And the above-mentioned structural supporting frame 70 can replace the connecting seat 12 in the first embodiment, so that the installation steps can be reduced, and the production cost can be reduced.

As shown in fig. 8, in the third embodiment, the top of the support frame 70 supports the bottom of the rotor 51, so that the gravity of the rotor 51 is borne by the support frame 70.

As shown in fig. 10, the electronic expansion valve according to the fourth embodiment is different from the electronic expansion valve according to the first embodiment in that the electronic expansion valve further includes a speed reduction mechanism 190. Specifically, the rotor 51 is connected with the input end of the speed reducing mechanism 190, and the screw rod 30 is connected with the output end of the speed reducing mechanism 190, so that the precision of the electronic expansion valve is more accurate, and the performance of the electronic expansion valve is improved.

The operation of the electronic expansion valve will be described in detail, wherein, as shown in fig. 3, D1 is the outer diameter of the first core section 21, D2 is the diameter D2 of the valve port 13, D3 is the outer diameter of the second core section 22, D4 is the inner diameter of the core assembly 20, SD1 is the sectional area of the first core section 21, SD2 is the area of the valve port 13, SD3 is the area of the second core section 22, and SD4 is the sectional area of the inner bore of the core assembly 20:

when the transverse pipe communicated from the second connector 15 is pressurized:

(1) when the core assembly 20 is in the closed position: the internal stress of the valve seat 10 is balanced, the horizontal pipe pressure acts on the core assembly 20, the core assembly 20 is acted by the area difference (SD3-SD2) and the pressure P to form an upward differential pressure F1, and is acted by the area difference (SD3-SD1) and the pressure P to form a downward differential pressure F2; F1-F2 are the resultant forces experienced by the core assembly 20. Wherein, F1-F2 (SD3-SD2) P- (SD3-SD1) P (SD3-SD2-SD3+ SD1) P (SD1-SD2) P. Therefore, in order to reduce the stress on the core assembly 20, the difference between the cross-sectional area SD2 of the valve port 13 and the cross-sectional area SD1 of the first core section 21 is 40mm or less². That is, SD2-SD1 ≈ 0, so the resultant upward and downward force of the core assembly 20 tends to zero, and the driving force required for the opening operation of the core assembly 20 is very small and not largeThe volume of the coil 52 must be increased, and the production cost is reduced.

(2) When the core assembly 20 is in the open position (the position where the core assembly 20 is away from the valve port 13): the pressures of the various parts of the internal cavity of the valve seat 10, the internal cavity of the outer shell 60, and the internal cavity of the core assembly 20 are relatively close, the horizontal tube pressure acts on the core assembly 20, the core assembly 20 is acted on by the area difference (SD3-SD4) and the pressure P to form the upward differential pressure force F3, the core assembly 20 is also acted on by the area difference (SD3-SD1) of the connecting surface 23 of the first core segment 21 and the second core segment 22 and the pressure chamber P to form the downward differential pressure force F4, and the area difference (SD1-SD4) of the top of the core assembly 20 and the pressure P to form the downward differential pressure force F5. F3- (F4+ F5) is the resultant force to which the core assembly 20 is subjected. Wherein, F3- (F4+ F5) { (SD3-SD4) - [ (SD3-SD1) + (SD1-SD4) ] } P ═ 0 ═ P ═ 0 (SD3-SD4-SD3+ SD1-SD1+ SD 4). Because the difference of the upper and lower stressed areas is zero, the stress inside the valve seat 10 is balanced, so that the core body assembly 20 has small requirement on the driving force during opening and closing actions, the volume of the coil 52 does not need to be increased, and the production cost is reduced.

When the standpipe inlet pressure is communicated from the first port 14:

(1) when the core assembly 20 is in the closed position: the interior of the valve seat 10 is balanced, the standpipe pressure acts on the core assembly 20, and the area difference (SD2-SD4) between the core assembly 20 and the pressure P forms an upward differential pressure F6. The area difference (SD1-SD4) acts with the pressure P to form a downward pressure differential force F7. SD2-SD1 is approximately equal to 0, so that the upper and lower resultant forces (F6-F7) of the core assembly 20 tend to zero, the requirement on driving force during opening action is extremely small, the volume of the coil 52 does not need to be increased, and the production cost is reduced.

(2) When the core assembly 20 is in the open position: the pressures in the interior cavity of the valve seat 10, the interior cavity of the housing 60, and the interior cavity of the core assembly 20 are relatively close, the standpipe pressure acts on the core assembly 20, and the core assembly 20 is subjected to the area difference (SD3-SD4) and the pressure P to form an upward differential pressure force F8. The downward differential pressure force F9 is created by the area difference (SD3-SD1) of the connection faces 23 of the first core segment 21 and the second core segment 22 acting with the pressure P, and the downward differential pressure force F10 is created by the area difference (SD1-SD4) of the top of the core assembly 20 acting with the pressure P. F8- (F9+ F10) is the resultant force to which the core assembly 20 is subjected. Wherein { (SD3-SD4) - [ (SD3-SD1) + (SD1-SD4) ] } P ═ 0 ═ P ═ 0 (SD3-SD4-SD3+ SD1-SD1+ SD 4). Because the difference of the upper and lower stressed areas is zero, the stress inside the valve seat 10 is balanced, so that the core body assembly 20 has small requirement on the driving force during opening and closing actions, the volume of the coil 52 does not need to be increased, and the production cost is reduced.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic expansion valve, comprising:

a valve seat (10), the valve seat (10) having a valve seat cavity (4) and a valve port (13);

a core assembly (20), at least a portion of the core assembly (20) being movably disposed in the valve seat cavity (4);

the screw rod (30) is in threaded fit with the nut (40), and the nut (40) is fixedly connected with the core body assembly (20);

the support frame (70), the support frame (70) and the valve seat (10) are directly or indirectly fixedly connected, the support frame (70) is provided with a matching groove (72), the nut (40) is provided with a protruding part (42), and the protruding part (42) is matched with the matching groove (72);

the driving mechanism (50) comprises a rotor (51) and a coil (52), the rotor (51) is fixedly connected with the screw rod (30), the rotor (51) drives the screw rod (30) to rotate through the coil (52), the nut (40) can move along the axial direction and does not rotate circumferentially through the screw matching action with the screw rod (30) and the matching action with the matching groove (72), the core component (20) can approach or leave the valve port (13) through the driving of the nut (40), the valve seat (10) comprises a valve seat body (11) and a connecting seat (12), the connecting seat (12) is fixedly connected with the valve seat body (11), the valve port (13) is arranged on the valve seat body (11), the connecting seat (12) is provided with a connecting seat cavity (121), and the core component (20) is press-fitted into the connecting seat cavity (121), the support frame (70) is fixedly connected with the valve seat body (11) through the connecting seat (12), the valve seat (10) is provided with a first interface (14) and a second interface (15) which are arranged at intervals, the first interface (14) is communicated with the valve port (13), a cavity (1) communicated with the valve port (13) is arranged in the core body assembly (20), the core assembly (20) being in sealing connection with the valve seat (10), the core assembly (20) comprising a first core section (21) and a second core section (22), the outer diameter of the second core section (22) is matched with the cavity wall of the connecting seat cavity (121), the electronic expansion valve further comprises a sealing structure (170) arranged between the connecting seat (12) and the first core section (21), to seal a gap between the connection socket (12) and the first core section (21).

2. The electronic expansion valve according to claim 1, wherein the nut (40) comprises a nut body portion (41) and the protrusion portion (42) provided on a side wall of the nut body portion (41) and extending outward, the nut body portion (41) being provided with a threaded hole, the lead screw (30) being inserted through the threaded hole.

3. An electronic expansion valve according to claim 1, wherein the support frame (70) is cup-shaped, the support frame (70) comprises a side wall, the side wall of the support frame (70) is fixedly connected with the connecting seat (12), the screw rod (30) penetrates into an inner cavity of the support frame (70) along an axial direction of the support frame (70), at least a portion of the nut (40) is located in the inner cavity, the side wall is provided with a first opening, the nut (40) is provided with a first projection extending into the first opening, the first opening forms the fitting groove (72), and the first projection forms the protrusion (42).

4. An electronic expansion valve according to claim 3, wherein the support frame (70) further comprises a top wall, the lead screw (30) is arranged through the top wall and extends into the inner cavity, and a first elastic member (110) is arranged between the upper surface of the nut (40) and the top wall.

5. An electronic expansion valve according to claim 1, wherein a second resilient member (180) is arranged between the upper surface of the nut (40) and the rotor (51) to support the rotor (51).

6. An electronic expansion valve according to claim 1, wherein the support frame (70) is ring-shaped, the support frame (70) comprises a circumferential wall, the circumferential wall of the support frame (70) is fixedly connected with the connecting seat (12), the circumferential wall is provided with a second opening, the nut (40) is provided with a second projection extending into the second opening, the second opening forms the mating groove (72), and the second projection forms the protruding part (42).

7. An electronic expansion valve according to claim 1, wherein the support frame (70) is cylindrical, the side wall of the support frame (70) is fixedly connected to the valve seat (10), the inner hole of the support frame (70) comprises a limiting hole section (71) and a guiding hole section (73) located below the limiting hole section (71), the fitting groove (72) is provided in the limiting hole section (71), the inner diameter of the guiding hole section (73) is adapted to the outer diameter of the core assembly (20), the nut (40) is provided with a third projection extending into the fitting groove (72), and the third projection forms the protruding portion (42).

8. An electronic expansion valve according to claim 1, wherein the cross-sectional area of the first core section (21) is set to SD1, and the cross-sectional area of the valve port (13) is set to SD2, satisfying the following relationship: (SD2-SD1) is less than or equal to 40mm²。

9. The electronic expansion valve of claim 1, further comprising:

the rotor (51) is connected with the input end of the speed reducing mechanism (190), and the screw rod (30) is connected with the output end of the speed reducing mechanism (190).