CN109210212B

CN109210212B - Electric valve

Info

Publication number: CN109210212B
Application number: CN201710519696.2A
Authority: CN
Inventors: 刘锡波; 杨仕钊; 周文荣
Original assignee: Zhejiang Sanhua Automotive Components Co Ltd
Current assignee: Zhejiang Sanhua Automotive Components Co Ltd
Priority date: 2017-06-30
Filing date: 2017-06-30
Publication date: 2020-01-21
Anticipated expiration: 2037-06-30
Also published as: CN109210212A

Abstract

The invention discloses an electric valve, which comprises a valve body, a valve core assembly and a coil assembly, wherein the valve core assembly comprises a piston, a valve seat, a valve needle and a rotor, the valve seat is provided with a first valve port, the valve body is provided with a second valve port, a first interface, a second valve port and a bypass channel, one end part of the first valve port is communicated with the first interface, the other end part of the first valve port is communicated with the second interface through the bypass channel, a third valve port is arranged between the second valve port and the second interface, and a one-way valve is arranged between the third valve port and the second interface; when the second interface is used as an inlet, when the flow area of the throttling channel formed between the valve needle and the first valve port is smaller than the sectional area of the first valve port, the second valve port and the third valve port are closed, the second interface is communicated with the first interface through the bypass channel and the first valve port, and the flow area of the throttling channel formed between the valve needle and the first valve port is changed along with the change of the distance between the valve needle and the first valve port.

Description

Electric valve

Technical Field

The invention relates to the field of fluid control, in particular to an electric valve.

Background

With the increasing requirements of people on energy conservation and emission reduction and the increasing requirements on the performance of an air conditioning system, the heat pump type air conditioning system also becomes a current hot application. However, the conventional expansion valve, whether it is an electronic expansion valve or a thermostatic expansion valve, can only play a role of throttling. If the functions of throttling and full opening and full closing are required to be realized, the scheme that a plurality of expansion valves and a plurality of electromagnetic valves are combined in an air conditioning system is often required to realize the functions of throttling and full opening and full closing.

With the increase of the performance requirement of the air conditioning system and the increase of the compact requirement of the air conditioning system, based on the consideration of cost, the technical problem which needs to be solved urgently by those skilled in the art is to provide the electric valve with the functions of throttling, fully opening and fully closing.

Disclosure of Invention

In order to solve the technical problems, the technical scheme of the invention is to provide an electric valve which has the functions of throttling, fully opening and fully closing.

The invention provides an electric valve, which comprises a valve body, a valve core assembly and a coil assembly, wherein the valve core assembly comprises a piston, a valve seat, a valve needle and a rotor, a return spring is arranged between the piston and the valve seat, one end of the return spring is abutted against the piston, the other end of the return spring is abutted against the valve seat, the return spring is in a compressed state, the valve seat is provided with a first valve port, the valve body is provided with a cavity with an opening at one end, the bottom wall of the cavity with the opening at one end is provided with a second valve port, the outer walls of at least two parts of the valve seat are in sealing fit with the inner wall corresponding to the cavity with the opening at one end, the first valve port is positioned between the two parts of the valve seat which are in sealing fit with the inner wall corresponding to the cavity with the opening at one end, the valve body is also provided with a first interface, a second, the piston is provided with a fluid channel which is communicated with the upper end part of the first valve port and the first interface, one end part of the first valve port is communicated with the first interface, and the other end part of the first valve port is communicated with the second interface through the bypass channel;

when the valve needle is far away from the first valve port and at least a part of the valve needle is positioned in the first valve port, the flow area of a throttling channel formed between the valve needle and the first valve port is smaller than the sectional area of the first valve port, the electric valve is in a throttling state, at the moment, the piston is abutted against the second valve port, the second valve port is closed, the first interface is communicated with the second interface through the first valve port and the bypass channel, and the flow area of the throttling channel formed between the valve needle and the first valve port is changed along with the change of the distance between the valve needle and the first valve port.

The cavity with one open end of the valve body comprises a first sub-cavity, a second sub-cavity and a third sub-cavity, the first sub-cavity, the second sub-cavity and the third sub-cavity are sequentially communicated, the inner diameter of the first sub-cavity is larger than that of the second sub-cavity, the inner diameter of the second sub-cavity is larger than that of the third sub-cavity, the first interface is communicated with the first cavity, the valve body further comprises a first cavity, a second cavity and a third cavity, the first cavity is communicated with the first interface, the third cavity is communicated with the second interface, the first cavity is communicated with the third sub-cavity, the second cavity is positioned below the third sub-cavity, the second valve port is positioned between the second cavity and the third sub-cavity, the second cavity is positioned between the first cavity and the third cavity, the first cavity is not directly communicated with the second cavity, and the second cavity is communicated with the third cavity, the bypass channel is adjacent to the third sub-cavity, one end of the bypass channel is located on the bottom wall of the second sub-cavity, and the other end of the bypass channel is located on the side of the third cavity.

The valve seat comprises a first valve seat main body and a second valve seat main body, the first valve seat main body and the second valve seat main body are arranged adjacently, the outer diameter of the first valve seat main body is larger than that of the second valve seat main body, the valve seat is further provided with a valve seat upper cavity, the first valve port is arranged on the part corresponding to the bottom wall of the valve seat upper cavity, the valve seat is further provided with a first channel and a second channel, one end of the first valve port is communicated with the first channel, the other end of the first valve port is communicated with the second channel, the second channel penetrates through the bottom wall of the valve seat upper cavity and is communicated with the outside of the valve seat, one end, far away from the first valve port, of the first channel is located on the outer wall of the second valve seat main body, and the first channel is communicated with one end of the first valve port and.

The valve seat is further provided with a valve seat lower cavity, the second channel is communicated with the valve seat upper cavity and the valve seat lower cavity, one part of the valve needle is located in the valve seat upper cavity, and one part of the return spring is located in the valve seat lower cavity.

The outer wall of the first valve seat main body is in clearance fit with the inner wall of the first sub-cavity, at least one first sealing element is arranged between the outer wall of the first valve seat main body and the inner wall of the first sub-cavity, one part of the second valve seat main body is positioned in the second sub-cavity, one part of the second valve seat main body is positioned in the third sub-cavity, the second valve seat main body is positioned between the outer wall of the third sub-cavity and the inner wall of the third sub-cavity in clearance fit, at least one second sealing element is arranged between the outer wall of the second valve seat main body and the inner wall of the third sub-cavity, the port of the first channel at the outer wall part of the second valve seat main body is positioned in the second sub-cavity, and an annular flow passage is formed between the inner wall of the second sub-cavity and the outer wall of the second valve seat main body, the annular flow passage communicates the first passage and the bypass passage.

At least one annular toothed protrusion is arranged at the lower end part of the first valve seat main body, the toothed protrusion is abutted against the bottom wall of the first sub-cavity, the hardness of the toothed protrusion is greater than that of the bottom wall of the first sub-cavity, and when the toothed protrusion is abutted against the bottom wall of the first sub-cavity, the toothed protrusion can be embedded into the bottom wall of the first sub-cavity;

or at least one annular toothed bulge is arranged on the bottom wall of the first sub-cavity, the toothed bulge is abutted with the lower end part of the first valve seat main body, the hardness of the toothed bulge is greater than that of the lower end part of the first valve seat main body, and when the toothed bulge is abutted with the lower end part of the first valve seat main body, the toothed bulge can be embedded into the lower end part of the first valve seat main body.

The piston comprises a first piston main body and a second piston main body, the outer diameter of the first piston main body is larger than that of the second piston main body, the piston is further provided with a piston upper cavity and a sealing block accommodating cavity, the piston upper cavity and the sealing block accommodating cavity are located on two opposite sides of the piston, a fluid channel of the piston comprises a first sub-channel and a second sub-channel, one end of the first sub-channel is located on the bottom wall corresponding to the piston upper cavity, the other end of the first sub-channel is communicated with the second sub-channel, the second sub-channel is located below the first sub-channel, the piston upper cavity is communicated with the outside of the piston through the first sub-channel and the second sub-channel in sequence, and the second sub-channel comprises at least one port located on the outer wall of the second piston main body.

Sliding fit between the outer wall of first piston main part with the inner wall of third subchamber be provided with the third sealing member between the outer wall of first piston main part and the inner wall of third subchamber, the outer wall of second piston main part with certain distance has between the inner wall of third subchamber, first chamber passes through second subchannel, first subchannel and second passageway with the disk seat epicoele keeps the intercommunication.

A third valve port is arranged between the second chamber and the third chamber, a one-way valve is further arranged in the third chamber, the one-way valve comprises a one-way valve core and a support, the one-way valve core can freely slide along the support, when the fluid pressure on the second interface side is greater than the fluid pressure on the third valve port side, the one-way valve core is abutted against the third valve port, and the third valve port is closed.

The throttling state of the electric valve comprises the first throttling state, and when the first interface is an inlet, the electric valve comprises a fully-opened state, a fully-closed state and a first throttling state;

in the full-closed state, the valve needle is abutted with the first valve port, the piston is abutted with the second valve port, and the first interface is not communicated with the second interface;

in the fully-opened state, the valve needle is far away from a first valve port, the first valve port is opened, the flow area formed between the valve needle and the first valve port is larger than the flow area formed between the valve needle and the first valve port in the throttling state, the piston is far away from a second valve port, the second valve port is opened, and the first interface is communicated with the second interface through the second valve port.

The throttling state of the electric valve comprises a second throttling state, when the second interface is an inlet, the electric valve comprises the second throttling state, in the second throttling state, the valve core of the one-way valve is abutted against the third valve port, the third valve port is closed, the flow area of a throttling channel formed between the valve needle and the first valve port is smaller than or equal to the sectional area of the first valve port, the piston is abutted against the second valve port, the second valve port is closed, and the second interface is communicated with the first interface through the bypass channel and the first valve port.

The electric valve has the advantages that the electric valve has throttling, large-flow full-through and full-closed fluid flow control by controlling the relation between the valve needle and the first valve port.

Drawings

Fig. 1 is a schematic perspective view of an electrically operated valve according to an embodiment of the present invention.

Figure 2 is a schematic cross-sectional view of the electrically operated valve of figure 1 when fully closed.

Figure 3 is a schematic cross-sectional view of the body of the electrically operated valve of figure 1.

Figure 4 is a schematic cross-sectional view of the valve seat of the electrically operated valve of figure 1.

Figure 5 is a schematic cross-sectional piston view of the electrically operated valve of figure 1.

Figure 6 is a schematic cross-sectional view of the electrically operated valve of figure 1 in a first throttle state.

Figure 7 is a schematic cross-sectional view of the electrically operated valve of figure 1 in a fully open state.

Figure 8 is a schematic cross-sectional view of the electrically operated valve of figure 1 in a second throttle condition.

Wherein the arrows in the figures are schematic directions of fluid flow.

Detailed Description

The technical solutions of the present invention are specifically described below with reference to the drawings and the detailed description, and the orientation terms described in the present specification are set forth according to the orientation relationships in the drawings or the corresponding orientation relationships in the drawings.

As shown in fig. 1, the electrically operated valve includes a valve body 1, a valve core assembly 2 and a coil assembly 3, wherein the coil assembly 3 may be sleeved on the valve core assembly 2, and the coil assembly 3 may be fixed to the valve body 1 by screws or the like. A circuit board and a connector may also be provided in the coil block 3, wherein the circuit board and the connector may be integrated.

As shown in fig. 2 to 5, the valve core assembly 2 includes a piston 5, a valve seat 4, a valve needle 21 and a rotor 22, a return spring 7 is disposed between the piston 5 and the valve seat 4, one end of the return spring 7 abuts against the piston 5, the other end of the return spring 7 abuts against the valve seat 4, and the return spring 7 is in a compressed state. The valve seat 4 is fixed with the valve body 1, the rotor 22 can be driven by the coil component 3 to rotate, and the valve needle 21 can be driven by the rotor 22 to perform an up-and-down feeding action.

As shown in fig. 4, the valve seat 4 includes a first valve seat body 41 located at an upper portion and a second valve seat body 42 located at a lower portion, wherein the first valve seat body 41 is disposed adjacent to the second valve seat body 42, an outer diameter of the first valve seat body 41 is larger than an outer diameter of the second valve seat body 42, at least one groove for accommodating a sealing member is disposed on an outer wall of the first valve seat body 41, and in the present embodiment, two grooves for accommodating a sealing member are provided. The valve seat 4 is further provided with a valve seat upper chamber 44 and a valve seat lower chamber 47, wherein one end of the valve seat upper chamber 44 relatively far away from the valve seat lower chamber 47 is opened, and one end of the valve seat lower chamber 47 relatively far away from the valve seat upper chamber 44 is opened. The valve seat 4 is also provided with a second passage 45 communicating the valve seat upper chamber 44 and the valve seat lower chamber 47. The valve seat 4 is further provided with a first valve port 43, and the first valve port 43 is arranged at a portion of the valve seat 4 corresponding to the bottom of the valve seat upper chamber 44, and the first valve port 43 is arranged adjacent to the second channel 45. A first passage 46 is provided in the second valve seat body 42, one end of the first passage 46 communicates with the first port 43, the other end of the first passage 46 is located on the outer wall of the second valve seat body 42, and the first port 43 can communicate with the outside of the valve seat 4 through the first passage 46.

The outer wall of the second valve seat body 42 is also provided with a groove for receiving a seal, the groove of the outer wall of the second valve seat body 42 being located below the first passage 46.

It should be noted here that in other embodiments, the lower valve seat cavity 47 may not be provided, and the upper valve seat cavity 44 may communicate with the outside of the valve seat 4 through the second passage 45. In the embodiment, the valve seat lower cavity 47 is arranged to accommodate one end of the return spring 7 in the valve seat lower cavity 47, so that the stability of the return spring 7 can be improved, and the return spring 7 is prevented from deviating.

As shown in fig. 1, the rotor 22 can drive the valve needle 21 to move up and down, so that the valve needle 21 can be far away from the first valve port 43 or abut against the first valve port 43, and the flow rate of the fluid passing through the first valve port 43 can be controlled by the distance relationship between the valve needle 21 and the first valve port 43. When the valve needle 21 abuts against the first valve port 43, the first valve port 43 is closed, and fluid cannot pass through the first valve port 43; as the valve needle 21 gradually moves away from the first valve port 43, the flow rate of the fluid passing through the first valve port 43 gradually increases, when the flow area of the fluid passing through the first valve port 43 is smaller than the first channel 46 and/or the second channel 45, the channel formed between the valve needle 21 and the first valve port 43 can be used as a throttling channel, and when the high-pressure refrigerant passes through the channel formed between the valve needle 21 and the first valve port 43, the high-pressure refrigerant is throttled and depressurized to form a low-pressure refrigerant. In the present embodiment, the inner diameter of the first valve port 43 is smaller than the inner diameter of the first passage 46 and/or the second passage 45.

As shown in fig. 3, the valve body 1 is provided with a chamber having one end opened, and includes: a first sub-chamber 181, a second sub-chamber 182, and a third sub-chamber 183. The valve body 1 is provided with a first connector 11, a second connector 12, a first cavity 19, a second cavity 16, a third cavity 17, a first sub-cavity 181, a second sub-cavity 182 and a third sub-cavity 183, wherein the first sub-cavity 181, the second sub-cavity 182 and the third sub-cavity 183 are arranged from top to bottom and communicated in sequence, the inner diameter of the first sub-cavity 181 is larger than that of the second sub-cavity 182, and the inner diameter of the second sub-cavity 183 is larger than that of the third sub-cavity 183. One end of the first sub-chamber 181 is open, and an internal thread 184 is provided in the first sub-chamber 181 near the open portion.

First port 11 is in communication with first chamber 19, and first chamber 19 is in communication with third subchamber 183. The communicating part 185 may be further provided at a position where the first chamber 19 and the third subchamber 183 communicate with each other, a bottom wall of the communicating part 185 has a spiral structure, and the communicating part 185 may be provided to allow the fluid to flow more smoothly from the first chamber 19 to the third subchamber 183, and the communicating part 185 may function to guide the fluid to flow.

Second chamber 16 is positioned below third subchamber 183 and second chamber 16 is positioned between first chamber 19 and third chamber 17, with first chamber 19 not being in direct communication with second chamber 16, and second chamber 16 being in communication with third chamber 17. A second valve port 13 is also provided between second chamber 16 and third subchamber 183 and first chamber 19 may communicate with second chamber 16 through third subchamber 183 and second valve port 13.

Third chamber 17 may be in communication with second port 12, third sub-chamber 183 may be in communication with second port 12 via second port 16, third chamber 17, and/or third sub-chamber 183 may be in communication with second port 12 via second sub-chamber 182, bypass passage 15, and third chamber 17.

In the present embodiment, a third port 14 is further disposed between the second chamber 16 and the third chamber 17, and the second chamber 16 is communicated with the third chamber 14 through the third port 14.

The valve body 1 is further provided with a bypass passage 15, one end of the bypass passage 15 is communicated with the second sub-cavity 182, the other end of the bypass passage 15 is communicated with the third cavity 17, and the bypass passage 15 is communicated with the second sub-cavity 182 and the third cavity 17. In this embodiment, the bypass passage 15 is parallel to the third sub-chamber 183 so that the bypass passage 15 can pass directly through the bottom wall of the second sub-chamber 182 to the third chamber 17 when the bypass passage 15 is machined.

As shown in fig. 5, the piston 5 includes a first piston main body 55 and a second piston main body 56, wherein the outer diameter of the first piston main body 55 is larger than the outer diameter of the second piston main body 56, and the piston 5 is further provided with a piston upper chamber 54 and a seal block accommodating chamber 51, the piston upper chamber 54 and the seal block accommodating chamber 51 being located at opposite sides of the piston 5. The piston 5 is further provided with a first sub-passage 52 and a second sub-passage 53, wherein one end of the first sub-passage 52 is located at the corresponding bottom wall of the piston upper chamber 54, and the other end of the first sub-passage 52 is communicated with the second sub-passage 53. The second sub-passage 53 is located below the first sub-passage 52, and the piston upper chamber 54 can communicate with the outside of the piston through the first sub-passage 52 and the second sub-passage 53 in this order.

In addition, the second sub-passage 53 includes at least one port located on the outer wall of the second piston main body 56, and when the number of ports of the second sub-passage 53 located on the outer wall of the second piston main body 56 is greater than or equal to 2, fluid can flow to the first sub-passage 52 through the second sub-passage 53 more smoothly.

As shown in fig. 2, the outer wall of the first valve seat body 41 of the valve seat 4 is in clearance fit with the inner wall of the first sub-chamber 181 of the valve body 1, and at least one first seal 401 is provided between the outer wall of the first valve seat body 41 and the inner wall of the first sub-chamber 181. The outer wall of the second valve seat body 42 is a clearance fit with the inner wall of the third sub-chamber 183 and at least one second seal 402 is provided between the outer wall of the second valve seat body 42 and the inner wall of the third sub-chamber 83. And the first passage 46 is ported at the second sub-chamber 182 at an outer wall portion of the second valve seat body 42, an annular flow passage 104 is formed between the inner wall of the second sub-chamber 182 and the outer wall of the second valve seat body 42, since the inner diameter of the second sub-chamber 182 is greater than the inner diameter of the third sub-chamber. The annular flow passage 104 communicates with the first passage 46, and the annular flow passage 104 also communicates with the bypass passage 15.

The valve seat 4 is fixed with the valve body 1 through a pressing block 6, the pressing block 6 is provided with external threads, and the external threads of the pressing block 6 are fixedly connected with the internal threads 184 of the first sub-cavity 181.

In order to improve the sealing performance between the valve seat 4 and the inner wall of the first sub-cavity 181, at least one annular toothed protrusion 48 is arranged at the lower end of the first valve seat main body 41, the toothed protrusion 48 abuts against the bottom wall of the first sub-cavity 181, the hardness of the toothed protrusion 48 is greater than that of the bottom wall of the first sub-cavity 181, and when the toothed protrusion 48 abuts against the bottom wall of the first sub-cavity 181, the toothed protrusion 48 can be embedded into the bottom wall of the first sub-cavity 181, so that the sealing performance is further improved, and the risk of external leakage is reduced. Of course, the tooth-shaped protrusion can also be arranged on the bottom wall of the first sub-cavity. It should be noted here that the risk of leakage out of the electric valve can be reduced by providing the first seal 401 and the toothed protrusion 48, and the risk of leakage in the electric valve can be reduced by providing the second seal 402.

The outer wall of the first piston main body 55 of the piston 5 is in sliding fit with the inner wall of the third sub-chamber 183, a third sealing member is arranged between the outer wall of the first piston main body 55 and the inner wall of the third sub-chamber 183, and a certain distance is reserved between the outer wall of the second piston main body 56 and the inner wall of the third sub-chamber 183, so that the first chamber 19 can be kept in a communication state with the valve seat upper chamber 44 through the second sub-passage 53, the first sub-passage 52 and the second passage 45. A sealing block is arranged in the sealing block accommodating cavity 51, and the piston 5 can be abutted against the second valve port 13 under the action of the return spring 7.

As shown in fig. 1, in the present embodiment, a check valve is further disposed in the third chamber 17, and the check valve includes a check valve spool 81 and a bracket 82, and the check valve spool 81 can freely slide along the bracket 82. When the fluid pressure on the second port 12 side is higher than the fluid pressure on the third port 14 side, the check valve spool 81 abuts against the third port 14, and the third port 14 is closed. When the fluid pressure on the second port 12 side is lower than the fluid pressure on the third port 14 side, the check valve spool 81 is away from the third port 14, and the third port 14 is opened.

It should be noted here that in the motor-operated valve of the other embodiment, the check valve may not be provided.

The operation of the electrically operated valve of the present embodiment will be further described with reference to the drawings.

As shown in fig. 1, the electric valve is in a fully closed state, in which the needle 21 abuts against the first port 43, the piston 5 abuts against the second port 13 under the action of the return spring 7, the first port 11 is not communicated with the valve seat upper chamber 44, the first port 11 is not communicated with the second chamber 16, and the first port 11 is not communicated with the second port 12. It should be noted here that when the piston 5 moves downward to close the second port 13, a pressurizing process is performed for the second chamber 16, so when the piston 5 closes the second port 13, the check valve spool 81 is away from the third port 14, the third port 14 is opened, and the second chamber 16 is communicated with the third chamber 17 through the third port 14.

As shown in fig. 6, the electric valve is in the first throttle state, in which the valve needle 21 is away from the first valve port 43, the first valve port 43 is opened, but at least a part of the valve needle 21 is located in the first valve port 43. In the first throttle state, the flow area of the throttle passage formed between the needle 21 and the first port 43 is smaller than the cross-sectional area of the first port 43. In the first throttle state, the piston 5 abuts against the second valve port 13 by the pressure difference of the fluid and the elastic force of the return spring 7, and the second valve port 13 is in a closed state. The first port 11 may communicate with the second port 12 sequentially through the second sub-passage 53, the first sub-passage 52, the second passage 45, the first valve port 43, the first passage 46, the annular flow passage 104, the bypass passage 15, and the third chamber 17. When the fluid flowing into the electric valve from the first port 11 is a high-pressure refrigerant, the fluid is throttled and depressurized while passing through a throttle passage formed between the needle 21 and the first valve port 43, and at this time, the electric valve has a function of throttling. It should be noted here that the flow area of the throttling passage formed between the valve needle 21 and the first valve port 43 is smaller than the flow area of the smallest passage among the second sub-passage 53, the first sub-passage 52, and the second sub-passage 45, and the flow area of the throttling passage formed between the valve needle 21 and the first valve port 43 can be controlled by the valve needle 21, so that the control of the flow rate is realized, and thus the throttling capacities with different requirements can be realized.

As shown in fig. 7, when the electric valve is in the full open state, at this time, the valve needle 21 is far away from the first port 43, the first port 43 is opened, and the first port 11 can be communicated with the second chamber 16 after passing through the second sub-passage 53, the first sub-passage 52, the second passage 45, the first port 43, the first passage 46, the annular flow passage 104, the bypass passage 15 and the third chamber 17 in sequence. Since the flow area of the throttling passage formed between the valve needle 21 and the first valve port 43 is smaller than the sectional area of the first valve port 43, the piston 5 moves upward under the pressure difference of the fluid to compress the return spring 7, the piston 5 moves away from the second valve port 13, and the second valve port 13 is opened. The first port 11 may communicate with the second port 12 sequentially through the second port 13, the second chamber 16, the third port 14, and the third chamber 17. Since the flow resistance of the fluid passing through the second port 13, the second chamber 16, the third port 14, and the third chamber 17 in this order is smaller than the flow resistance of the fluid passing through the second sub-passage 53, the first sub-passage 52, the second passage 45, the first port 43, the first passage 46, the annular flow passage 104, the bypass passage 15, and the third chamber 17 in this order, when the fluid flows in through the first port 11, most of the fluid flows out from the second port 12 after passing through the second port 13, the second chamber 16, the third port 14, and the third chamber 17, and a full opening function is achieved.

As shown in fig. 8, the electric valve is in the second throttle state. Since the check valve is further disposed in the third chamber 17, when the second port 12 is used as an inlet and high-pressure refrigerant flows into the second port 12, the check valve spool 81 is pushed by the high-pressure refrigerant to abut against the third valve port 14, and the third valve port 14 is closed. At this time, the valve needle 21 is driven by the rotor 22 to be away from the first valve port 43 by a certain distance, the first valve port 43 is opened, the flow area of the throttling channel formed between the valve needle 21 and the first valve port 43 is smaller than or equal to the flow cross-sectional area of the first valve port 43, the piston 5 is abutted against the second valve port 13 under the action of the pressure difference of the fluid and the return spring 7, and the second valve port 13 is closed. The second port 12 may communicate with the first port 11 sequentially through the third chamber 17, the bypass passage 15, the annular flow passage 104, the first passage 46, the first valve port 43, the second passage 45, the first sub-passage 52, and the second sub-passage 53.

It should be noted here that the first throttle state, the fully-closed state, and the fully-open state can also be achieved when no check valve is provided. In the present embodiment, the check valve is installed through the second port 12, but the check valve may also be installed in other manners, for example, the bottom of the lower valve body 1 is installed by punching, and may be selected according to actual situations, which is not limited.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can now make numerous changes and modifications to the disclosed embodiments, and equivalents thereof, without departing from the scope of the invention as set forth in the claims below. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.

Claims

1. An electric valve comprises a valve body, a valve core assembly and a coil assembly, and is characterized in that the valve core assembly comprises a piston, a valve seat, a valve needle and a rotor, a return spring is arranged between the piston and the valve seat, one end of the return spring is abutted against the piston, the other end of the return spring is abutted against the valve seat, the return spring is in a compressed state, the valve seat is provided with a first valve port, the valve body is provided with a cavity with an opening at one end, the bottom wall of the cavity with the opening at one end is provided with a second valve port, the outer walls of at least two parts of the valve seat are in sealing fit with the inner wall corresponding to the cavity with the opening at one end, the first valve port is positioned between the two parts of the valve seat in sealing fit with the inner wall corresponding to the cavity with the opening at one end, the valve body is further provided with a first interface, a second, the piston is provided with a fluid channel which is communicated with the upper end part of the first valve port and the first interface, one end part of the first valve port is communicated with the first interface, and the other end part of the first valve port is communicated with the second interface through the bypass channel;

2. The electric valve according to claim 1, wherein the cavity with an opening at one end of the valve body comprises a first sub-cavity, a second sub-cavity and a third sub-cavity, the first sub-cavity, the second sub-cavity and the third sub-cavity are sequentially communicated, the inner diameter of the first sub-cavity is larger than that of the second sub-cavity, the inner diameter of the second sub-cavity is larger than that of the third sub-cavity, the valve body further comprises a first cavity, a second cavity and a third cavity, the first cavity is communicated with the first interface, the third cavity is communicated with the second interface, wherein the first cavity is communicated with the third sub-cavity, the second cavity is positioned below the third sub-cavity, the second valve port is positioned between the second cavity and the third sub-cavity, the second cavity is positioned between the first cavity and the third cavity, and the first cavity is not directly communicated with the second cavity, be linked together between second chamber and the third chamber, bypass passageway with the adjacent setting of third sub-chamber, bypass passageway's one end is located the diapire of second sub-chamber, bypass passageway's the other end is located the lateral wall of third chamber.

3. The electrically operated valve of claim 2, wherein the valve seat comprises a first valve seat body and a second valve seat body, the first valve seat body is arranged adjacent to the second valve seat body, the outer diameter of the first valve seat body is larger than that of the second valve seat body, the valve seat is also provided with a valve seat upper cavity, the first valve port is arranged at the part corresponding to the bottom wall of the valve seat upper cavity, the valve seat is also provided with a first channel and a second channel, one end of the first valve port is communicated with the first channel, the other end of the first valve port is communicated with the second channel, the second channel penetrates through the bottom wall of the upper cavity of the valve seat and is communicated with the outside of the valve seat, one end of the first channel, which is far away from the first valve port, is located on the outer wall of the second valve seat main body, and the first channel is communicated with one end of the first valve port and the bypass channel.

4. The electric valve according to claim 3, wherein the valve seat further comprises a lower valve seat cavity, the second channel communicates the upper valve seat cavity and the lower valve seat cavity, a part of the valve needle is located in the upper valve seat cavity, and a part of the return spring is located in the lower valve seat cavity.

5. The electrically operated valve of claim 4, wherein the outer wall of the first valve seat body is in clearance fit with the inner wall of the first sub-chamber, at least one first seal is provided between the outer wall of the first valve seat body and the inner wall of the first sub-chamber, a portion of the second valve seat body is located in the second sub-chamber, a portion of the second valve seat body is located in the third sub-chamber, the second valve seat body is in clearance fit between the outer wall of the third sub-chamber portion and the inner wall of the third sub-chamber, at least one second seal is provided between the outer wall of the second valve seat body and the inner wall of the third sub-chamber, the first passage is located in the second sub-chamber at a port of the outer wall portion of the second valve seat body, and an annular flow passage is formed between the inner wall of the second sub-chamber and the outer wall of the second valve seat body, the annular flow passage communicates the first passage and the bypass passage.

6. The electric valve according to claim 5, wherein at least one annular tooth-shaped protrusion is arranged at the lower end of the first valve seat body, the tooth-shaped protrusion abuts against the bottom wall of the first sub-cavity, the hardness of the tooth-shaped protrusion is greater than that of the bottom wall of the first sub-cavity, and the tooth-shaped protrusion can be embedded into the bottom wall of the first sub-cavity when the tooth-shaped protrusion abuts against the bottom wall of the first sub-cavity;

7. The electric valve according to claim 6, wherein the piston comprises a first piston body and a second piston body, the outer diameter of the first piston main body is larger than that of the second piston main body, the piston is also provided with a piston upper cavity and a sealing block accommodating cavity, the piston upper cavity and the seal block accommodating cavity are positioned on two opposite sides of the piston, the fluid passage of the piston comprises a first sub-passage and a second sub-passage, wherein one end of the first sub-channel is positioned at the corresponding bottom wall of the upper cavity of the piston, the other end of the first sub-channel is communicated with the second sub-channel, the second sub-channel is positioned below the first sub-channel, the piston upper cavity is communicated with the outside of the piston sequentially through the first sub-channel and the second sub-channel, and the second sub-channel comprises at least one port positioned on the outer wall of the second piston main body.

8. The electrically operated valve of claim 7, wherein the outer wall of the first piston body is in sliding engagement with the inner wall of the third sub-chamber, a third seal is disposed between the outer wall of the first piston body and the inner wall of the third sub-chamber, the outer wall of the second piston body is spaced from the inner wall of the third sub-chamber, and the first chamber is in communication with the valve seat upper chamber through the second sub-passage, the first sub-passage and the second passage.

9. An electrically operated valve according to any of claims 2 to 8, wherein a third port is provided between the second chamber and the third chamber, and a one-way valve is further provided in the third chamber, the one-way valve comprising a one-way valve spool and a bracket, the one-way valve spool being freely slidable along the bracket, the one-way valve spool abutting the third port when the fluid pressure at the second port side is greater than the fluid pressure at the third port side, the third port being closed.

10. The electrically operated valve according to any of claims 1 to 8, wherein the throttle state of the electrically operated valve comprises a first throttle state, and when the second port is an inlet, the electrically operated valve comprises a fully open state, a fully closed state and a first throttle state;

11. The electrically operated valve according to claim 9, wherein the throttle state of the electrically operated valve comprises a second throttle state, when the second port is an inlet, the electrically operated valve comprises a second throttle state, in the second throttle state, the check valve core abuts against the third port, the third port is closed, a flow area of a throttle passage formed between the valve needle and the first port is smaller than or equal to a cross-sectional area of the first port, the piston abuts against the second port, the second port is closed, and the second port is communicated with the first port through the bypass passage and the first port.