# Patent

## Title
Electronic expansion valve

## Abstract

An electronic expansion valve includes a drive component including a screw rod which reciprocates axially and a nut which cooperates with the screw rod by screw threads, and a lower end of the screw rod forms the valve needle component. A sleeve is fixed in the main valve cavity, an upper portion of the sleeve cooperates with the nut, and a lower end of the sleeve is supported by the valve seat and surrounds the main valve port. The valve core seat is axially movably arranged in the sleeve, and the lower end of the screw rod extends into the sleeve to open and close the valve core valve port. The structural design of the electronic expansion valve prevents an excessive impact on a valve core seat caused by the refrigerant with high pressure when the refrigerant flows forward, thereby preventing the eccentricity of the valve core seat.

## Background
The present application is the national phase of International Application No. PCT/CN2012/079927, filed on Aug. 10, 2012, which claims the benefit of priority to Chinese Patent Application No. 201210146266.8 titled “ELECTRONIC EXPANSION VALVE”, filed with the Chinese State Intellectual Property Office on May 11, 2012, the entire contents of which are incorporated herein by reference to the maximum extent allowable by law.
TECHNICAL FIELD
The present application relates to the technical field of fluid control components, and particularly to an electronic expansion valve.
BACKGROUND
In the air conditioner market, two electronic expansion valves are employed since an indoor unit is disposed far away from an outdoor unit of an air conditioner. In addition, each of the two electronic expansion valves is required to be connected to a respective one-way valve in parallel to improve the system efficiency to the greatest extent. The schematic diagram of the system of the air conditioner is shown in FIG. 1, and the working principle is briefly described as follows
The refrigerating operation is described as follows. Gaseous refrigerant with high temperature and high pressure which is discharged from a gas discharge pipe of a compressor 7′8 passes through, in turn, a connecting pipe D and a connecting pipe E of a four-way valve 7′1, an outdoor heat exchanger 7′2 (releasing heat by condensation), a first one-way valve 7′4 (here, a first electronic expansion valve 7′3 does not function to regulate the flow), and a second electronic expansion valve 7′5 (here, a second one-way valve 7′6 is closed, and the second electronic expansion valve 7′5 functions to regulate the flow), and finally enters into an indoor heat exchanger 7′7 to be evaporated, so as to absorb heat to realize the refrigerating function. Here, the second electronic expansion valve 7′6 is close to the indoor heat exchanger 7′7, thus the heat loss may be reduced (if the electronic expansion valve is too far away from the evaporator, the liquid refrigerant with low temperature and low pressure which is discharged from the electronic expansion valve is apt to be gasified, which not only causes heat loss, but also results in significant reduction of the utilization rate of the evaporator). Also, if the refrigerant with medium temperature and high pressure which is discharged from the outdoor heat exchanger 7′2 passes through the first electronic expansion valve 7′3, a throttling effect may still occur even when the expansion valve is fully opened, which reduces the pressure of the refrigerant, and then when the refrigerant is transferred to the second electronic expansion valve 7′5, it is apt to be gasified partly, therefore the throttling effect of the electronic expansion valve is adversely affected, and the system efficiency is reduced.
The heating operation is described as follows. Gaseous refrigerant with high temperature and high pressure which is discharged from the gas discharge pipe of the compressor 7′8 passes through, in turn, the connecting pipe D and a connecting pipe C of the four-way valve 7′1, the indoor heat exchanger 7′7 (releasing heat by condensation), the second one-way valve 7′6 (here, the second electronic expansion valve 7′5 does not function to regulate the flow), the first electronic expansion valve 7′3 (here, the first one-way valve 7′4 is closed, and the first electronic expansion valve 7′3 functions to regulate the flow), and finally enters into the outdoor heat exchanger 7′2 to be evaporated, so as to absorb heat to realize the refrigerating function. Here, the first electronic expansion valve 7′3 is close to the outdoor heat exchanger 7′2, thus the heat loss may be reduced (if the electronic expansion valve is too far away from the evaporator, the liquid refrigerant with low temperature and low pressure which is discharged from the electronic expansion valve is apt to be gasified, which not only causes heat loss, but also results in significant reduction of the utilization rate of the evaporator). Also, if the refrigerant with medium temperature and high pressure which is discharged from the indoor heat exchanger 7′7 passes through the second electronic expansion valve 7′5, the throttling effect may still occur even when the expansion valve is fully opened, which reduces the pressure of the refrigerant, and then when the refrigerant flows to the first electronic expansion valve 7′3, it is apt to be gasified partly, therefore the throttling effect of the electronic expansion valve is adversely affected, and the system efficiency is reduced.
However, in the current market, some customers require to integrate the one-way valve with the electronic expansion valve, so as to reduce the numbers of parts and solder joints, and to further improve the reliability of the system.
In view of this, in the conventional technology, an electronic expansion valve with function of a one-way valve is disclosed in Japanese Patent Application Publication No. 2009-287913. Reference may be made to FIGS. 2 and 3. FIG. 2 is a schematic view showing the structure of an electronic expansion valve in the conventional technology which is performing a flow regulation when the refrigerant flows forwards; and FIG. 3 is a schematic view showing the structure of the electronic expansion valve in the conventional technology, wherein the electronic expansion valve is opened when the refrigerant flows reversely.
As shown in FIGS. 2 and 3, the electronic expansion valve in the conventional technology includes a valve seat 1′. The valve seat 1′ is provided with a main valve cavity 1′1, a transverse connecting port 1′2 and a vertical connecting port 1′3, and an opening at an upper end of the vertical connecting port 1′3 forms a main valve port 1′31. A valve core seat 2′ is provided inside the main valve cavity 1′1, and a circumferential side wall of the valve core seat 2′ abuts against an inner circumferential side wall of the main valve cavity 1′1, thus the valve core seat 2′ is guided by the main valve cavity 1′1 and may reciprocate along an axial direction of the main valve cavity 1′1, so as to open or close the main valve port 1′31. Further, as shown in FIGS. 2 and 3, the valve core seat 2′ is provided with a secondary valve cavity 2′1, and a valve core valve port 2′2 in communication with the secondary valve cavity 2′1, and a valve needle component 3′ extends into the secondary valve cavity 2′1 and reciprocates along an axial direction of the secondary valve cavity 2′1, so as to open or close the calve core valve port 2′2. Furthermore, as shown in FIGS. 2 and 3, the circumferential side wall of the valve core seat 2′ is further provided with a communicating hole 2′3 in communication with the secondary valve cavity 2′1, and the communicating hole 2′3 faces the transverse connecting port 1′2, to allow the secondary valve cavity 2′1 to communicate with the transverse connecting port 1′2.
In addition, as shown in FIGS. 2 and 3, the transverse connecting port 1′2 is connected to a transverse connecting pipe 4′1, and the vertical connecting port 1′3 is connected to a vertical connecting pipe 4′2. The flow of the refrigerant fluid from the transverse connecting pipe 4′1 to the vertical connecting pipe 4′2 (i.e., a side of the transverse connecting port 1′2 is a high pressure zone, and a side of the vertical connecting port 1′3 is a low pressure zone) is defined as a forward flow, and the flow of the refrigerant fluid from the vertical connecting pipe 1′3 to the transverse connecting pipe 1′2 (i.e., the side of the vertical connecting port 1′3 is a high pressure zone, and the side of the transverse connecting port 1′2 is a low pressure zone) is defined as a reverse flow. The valve needle component 3′ is connected to a screw rod 5′1, and the screw rod 5′1 cooperates with a nut 5′2 by screw threads. In such structure, a magnet 6′2 is rotated under the action of a magnetic field of a coil 6′1; and then the screw rod 5′1 is rotated and axially reciprocates due to the screw-thread fit with the nut 5′2, thereby driving the valve needle component 3′ to reciprocate axially to open and close the valve bore valve port 2′2.
As shown in FIG. 2, when the refrigerant flows forward, the side of the transverse connecting port 1′2 is the high pressure zone, and the side of the vertical connecting port 1′3 is the low pressure zone. The valve core seat 2′ moves downward under the action of a pressure difference of the refrigerant, thereby closing the main valve port 1′31. On this basis, the refrigerant enters into the secondary valve cavity 2′1 from the transverse connecting port 1′2 through the communicating hole 2′3, the valve needle component 3′ opens the valve core valve port 2′2, and the refrigerant entered into the secondary valve cavity 2′1 flows to the vertical connecting port 1′3 via the valve core valve port 2′2, and in turn flows into the vertical connecting pipe 4′2. In this operation, the screw rod 5′1 moves axially to allow the valve needle component 3′ to regulate an opening of the valve core valve port 2′2, thereby achieving an object of flow regulation of the electronic expansion valve.
As shown in FIG. 3, when the refrigerant flows reversely, the side of the vertical connecting port 1′3 is the high pressure zone, and the side of the transverse connecting port 1′2 is the low pressure zone. Here, the valve core seat 2′ is pushed to move upward under the action of the pressure difference of the refrigerant, thereby opening the main valve port 1′31. The refrigerant flows through the main valve port 1′31, the main valve cavity 1′1 and the transverse connecting port 1′2 to the transverse connecting pipe 4′1, thereby achieving the function of one-way communication of the one-way valve.
However, the above electronic expansion valve in the conventional technology has the following defects.
As shown in FIG. 2, when the refrigerant flows forward, the side wall of the valve core seat 2′ faces the transverse connecting port 1′2, thus the circumferential side wall of the valve core seat 2′ may be impacted by the refrigerant with high pressure. When the pressure of the refrigerant fluctuates, an eccentricity of the valve core seat 2′ may be caused, thus the valve core seat 2′ can not tightly seal the main valve port 1′31, which causes a large internal leakage, and adversely affects the working performance of the system. Furthermore, the eccentricity of the valve core seat 2′ may cause interference between the valve needle component 3′ and the valve core valve port 2′2.
SUMMARY
The technical problem to be addressed by the present application is to provide an electronic expansion valve. The structural design of the electronic expansion valve may prevent an excessive impact on a valve core seat caused by the refrigerant with high pressure when the refrigerant flows forward, thereby preventing the eccentricity of the valve core seat, and avoiding an internal leakage, and ensuring the reliability of the operation of the system.
For solving the technical problem, an electronic expansion valve is provided according to the present application, which includes a valve seat, a vertical connecting pipe and a transverse connecting pipe, the valve seat is provided with a main valve cavity; the electronic expansion valve further includes a main valve port in communication with the vertical connecting pipe and a valve core seat configured to open and close the main valve port, the valve core seat is provided with a valve core valve port which allows a communication with the vertical connecting pipe; and the electronic expansion valve further includes a valve needle component configured to open and close the valve core valve port, wherein,
the electronic expansion valve further includes a drive component, the drive component includes a screw rod and a nut which cooperates with the screw rod by screw threads, and a lower end of the screw rod forms the valve needle component;
a sleeve is fixed in the main valve cavity, and an upper portion of the sleeve cooperates with the nut; the valve core seat is axially movably arranged in the sleeve, and a lower portion of the screw rod extends into the sleeve to open and close the valve core valve port; and
a circumferential side wall of the sleeve is provided with a first communicating hole close to the main valve port, the nut is provided with a second communicating hole configured to allow the main valve cavity to communicate with a sleeve upper cavity; and in a case that a fluid medium flows from the transverse connecting pipe to the vertical connecting pipe, the valve core seat closes the main valve port, a communication between the first communicating hole and the main valve port is disconnected, and meanwhile the sleeve upper cavity comes in communication with the main valve cavity via the second communicating hole; and in a case that the fluid medium flows from the vertical connecting pipe to the transverse connecting pipe, the valve core seat moves upward to open the main valve port, and the main valve port comes in communication with the main valve cavity via the first communicating hole.
Preferably, a lower end of the sleeve is supported by the valve seat, and the lower end of the sleeve surrounds the main valve port.
Preferably, the valve seat is provided with a vertical connecting port for mounting the vertical connecting pipe, and the lower end of the sleeve extends into the vertical connecting port and is supported by the vertical connecting port; and an inner wall of the lower end of the sleeve forms a main valve hole, and the main valve port is formed by an aperture at an upper portion of the main valve hole.
Preferably, a circumferential outer wall of a lower end of the valve core seat forms a valve core seat sealing portion for opening and closing the main valve port.
Preferably, an inner wall of the vertical connecting port is provided with a connecting port stepped portion, an outer portion of the lower end of the sleeve is provided with a first sleeve stepped portion, and the first sleeve stepped portion is supported on the connecting port stepped portion.
Preferably, the outer portion of the lower end of the sleeve is further provided with a second sleeve stepped portion, the vertical connecting pipe is sleeved on the lower end of the sleeve, and a top end surface of the vertical connecting pipe abuts against the second sleeve stepped portion.
Preferably, a valve core seat through hole is arranged axially in the valve core seat, and an aperture at an upper end of the valve core seat through hole forms the valve core valve port.
Preferably, a lower portion of the nut is provided with a nut inner guide hole, and an upper portion of the sleeve is provided with a sleeve outer guide portion fitted in the nut inner guide hole; and
a lower end of the sleeve outer guide portion is provided with a third sleeve stepped portion, and a lower end surface of the nut is further supported on the third sleeve stepped portion.
Preferably, the third sleeve stepped portion extends downwardly in an axial direction, and the first communicating hole is further provided on the third sleeve stepped portion in a radial direction of the sleeve.
Preferably, a valve core seat guide hole, and a main valve hole having an aperture at an upper end thereof to form the main valve port, are arranged coaxially inside the sleeve.
Preferably, the electronic expansion valve further includes a locating plate fixedly provided in the main valve cavity, the locating plate is provided with a non-circular profiled hole, and a circumferential outer wall of a lower portion of the nut is provided with a non-circular profiled portion configured to cooperate with the non-circular profiled hole to prevent the nut from rotating.
Preferably, the locating plate is provided with a third communicating hole, and the main valve cavity below the locating plate is in communication with the second communicating hole through the third communicating hole.
Preferably, the circumferential outer wall of the lower portion of the nut is provided with a nut stepped portion, and an elastic component is sleeved on the circumferential outer wall of the nut, and is elastically compressed between the locating plate and the nut stepped portion.
On basis of the conventional technology, the electronic expansion valve provided by the present application further includes a drive component, the drive component includes a screw rod which reciprocates axially and a nut which cooperates with the screw rod by screw threads, and a lower end of the screw rod forms the valve needle component;
a sleeve is fixed in the main valve cavity, an upper portion of the sleeve cooperates with the nut, and further, a lower end of the sleeve is supported by the valve seat, and the main valve port is surrounded by the lower end of the sleeve; and the valve core seat is axially movably arranged in the sleeve, and the lower end of the screw rod extends into the sleeve to open and close the valve core valve port; and
a circumferential side wall of the sleeve is provided with a first communicating hole close to the main valve port, and the nut is provided with a second communicating hole configured to allow the main valve cavity to communicate with a sleeve upper cavity; and when the valve core seat closes the main valve port, the communication between the first communicating hole and the main valve port is disconnected, and meanwhile the sleeve upper cavity comes in communication with the main valve cavity via the second communicating hole; and when the valve core seat opens the main valve port, and the main valve port comes in communication with the main valve cavity via the first communicating hole.
When the refrigerant flows forward, the side of the transverse connecting pipe is a high pressure zone, and the side of the vertical connecting pipe is a low pressure zone. The valve core seat moves downward under the action of a pressure difference of the refrigerant to close the main valve port. On this basis, the refrigerant enters into the sleeve upper cavity via the second communicating hole, and when the valve needle component opens the valve core valve port, the refrigerant in turn enters into the side of the vertical connecting pipe via the valve core valve port. In this process, the valve needle component may reciprocate axially with the screw rod, thereby regulating an opening of the valve core valve port, and achieving the object of flow regulation of the electronic expansion valve.
When the refrigerant flows reversely, the side of the vertical connecting pipe is a high pressure zone, and the side of the transverse connecting pipe is a low pressure zone. The valve core seat moves upward under the action of the pressure difference of the refrigerant, thereby opening the main valve port. The refrigerant passes through the main valve port, and then flows to the side of the transverse connecting pipe via the first communicating hole, thereby achieving the object of one-way communication of a one-way valve.
In the above operation, when the refrigerant flows forward, the valve core seat is arranged in the sleeve, and the sleeve is fixedly arranged in the main valve cavity, thus the pressure impact on the valve core seat from the high pressure refrigerant is largely borne by the sleeve, which significantly reduces the impact on the valve core seat, thereby preventing the eccentricity of the valve core seat, and avoiding an internal leakage, and ensuring the reliability of the operation of the system. In addition, the refrigerant flows in through the second communicating hole provided on the nut. The position of the nut is higher than that of the valve core seat, thus the position of the second communicating hole is higher than that of the valve core seat, i.e. the refrigerant flows in through the second communicating hole above the valve core seat, thereby reducing the impact on the valve core seat from the refrigerant.
In summary, the electronic expansion valve according to the present application may prevent an excessive impact on the valve core seat caused by the refrigerant with high pressure, thereby preventing the eccentricity of the valve core seat, and avoiding an internal leakage, and ensuring the reliability of the operation of the system.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing the operating principle of an air conditioning refrigerating system in the conventional technology;
FIG. 2 is a schematic view showing the structure of an electronic expansion valve in the conventional technology which is performing a flow regulation when the refrigerant flows forwards;
FIG. 3 is a schematic view showing the structure of the electronic expansion valve in the conventional technology, wherein the electronic expansion valve is opened when the refrigerant flows reversely;
FIG. 4 is a schematic view showing the structure of an electronic expansion valve according to an embodiment of the present application which is performing a flow regulation when the refrigerant flows forwards;
FIG. 5 is a schematic view showing the structure of the electronic expansion valve in FIG. 4, wherein the electronic expansion valve is opened when the refrigerant flows reversely;
FIG. 6 is a schematic view showing the structure of a sleeve of the electronic expansion valve in FIGS. 4 and 5;
FIG. 7 is a schematic view showing the structure of a valve core seat of the electronic expansion valve in FIGS. 4 and 5;
FIG. 8 is a partially enlarged view of portion A in FIG. 5;
FIG. 9 is a schematic view showing the structure of a nut of the electronic expansion valve in FIGS. 4 and 5;
FIG. 9-1 is a sectional view of the nut in FIG. 9; and
FIG. 10 is a schematic view showing the structure of a locating plate of the electronic expansion valve in FIGS. 4 and 5.
Corresponding relationships between reference numerals and components in FIGS. 1 to 3 are as follows:















1′
valve seat,
1′1
main valve cavity,


1′2
transverse connecting port,
1′3
vertical connecting port;


1′31
main valve port;
2′
valve core seat,


2′1
secondary valve cavity,
2′2
valve core valve port,


2′3
communicating hole;
3′
valve needle component;


4′1
transverse connecting pipe,
4′2
vertical connecting pipe;


5′1
screw rod,
5′2
nut;


6′1
coil,
6′2
magnet;


7′1
four-way valve,
7′2
outdoor heat exchanger,


7′3
first electronic expansion
7′4
first one-way valve,



valve,


7′5
second electronic expansion
7′6
second one-way valve,



valve,


7′7
indoor heat exchanger, and
7′8
compressor.









Corresponding relationships between reference numerals and components in FIGS. 4 to 10 are as follows:















1
valve seat,
11
main valve cavity,


12
transverse connecting port,
13
vertical connecting port,


131
connecting port stepped
2
valve core seat,



portion;


21
valve core valve port,
22
valve core seat sealing





portion,


23
valve core seat through
4
sleeve,



hole;


41
first communicating hole,
42
third sleeve stepped





portion,


43
sleeve upper cavity,
44
main valve hole,


441
main valve port,
45
first sleeve stepped





portion,


46
second sleeve stepped
47
sleeve outer guide portion,



portion,


48
valve core seat guide hole,
51
vertical connecting pipe,


52
transverse connecting pipe;
61
screw rod,


611
valve needle component;
62
nut;


621
nut inner guide hole;
622
second communicating





hole;


623
non-circular profiled
71
magnet;



portion;


8
locating plate;
81
non-circular profiled hole;


82
third communicating hole;
9
elastic component.



and












DETAILED DESCRIPTION
An object of the present application is to provide an electronic expansion valve. The structural design of the electronic expansion valve may prevent an excessive impact on a valve core seat caused by the refrigerant with high pressure when the refrigerant flows forward, thereby preventing the eccentricity of the valve core seat, and avoiding an internal leakage, and ensuring the reliability of the operation of the system.
For those skilled in the art to better understand technical solutions of the present application, the present application is described in detail in conjunction with drawings and embodiments hereinafter.
Reference is made to FIGS. 4 and 5. FIG. 4 is a schematic view showing the structure of an electronic expansion valve according to an embodiment of the present application which is performing a flow regulation when the refrigerant flows forwards; and FIG. 5 is a schematic view showing the structure of the electronic expansion valve in FIG. 4, wherein the electronic expansion valve is opened when the refrigerant flows reversely.
In one embodiment, as shown in FIGS. 4 and 5, the electronic expansion valve according to the present application includes a valve seat 1. The valve seat 1 is provided with a main valve cavity 11, a transverse connecting port 12 and a vertical connecting port 13. A transverse connecting pipe 52 is installed at the transverse connecting port 12, and a vertical connecting pipe 51 is installed at the vertical connecting port 13. The electronic expansion valve further includes a main valve port 441 in communication with the vertical connecting pipe 51, and a valve core seat 2 configured to open and close the main valve port 441. The valve core seat 2 is provided with a valve core valve port 21 which allows a communication with the vertical connecting pipe 51. The electronic expansion valve further includes a valve needle component 611 configured to open and close the valve core valve port 21.
On the basis of the above structure, as shown in FIGS. 4 and 5, the electronic expansion valve further includes a drive component. The drive component includes a screw rod 61 which reciprocates axially and a nut 62 which cooperates with the screw rod 61 by screw threads, and a lower end of the screw rod 61 forms the valve needle component 611. A sleeve 4 is fixed in the main valve cavity 11, an upper portion of the sleeve 4 cooperates with the nut 62, a lower end of the sleeve 4 is supported by the valve seat 1, and the main valve port 441 is surrounded by the lower end of the sleeve 4. The valve core seat 2 is axially movably arranged in the sleeve 4, and the lower end of the screw rod 61 extends into the sleeve 4 to open and close the valve core valve port 21.
Further, as shown in FIGS. 4 and 5, a circumferential side wall of the sleeve 4 is provided with a first communicating hole 41 close to the main valve port 441, and the nut 62 is provided with a second communicating hole 622 configured to allow the main valve cavity 11 to communicate with a sleeve upper cavity 43. When the fluid medium flows from the transverse connecting pipe 52 to the vertical connecting pipe 51, the valve core seat 2 closes the main valve port 441, and the communication between the first communicating hole 41 and the main valve port 441 is disconnected, and meanwhile the sleeve upper cavity 43 comes in communication with the main valve cavity 11 via the second communicating hole 622. When the fluid medium flows from the vertical connecting pipe 51 to the transverse connecting pipe 52, the valve core seat 2 opens the main valve port 441, and the main valve port 441 comes in communication with the main valve cavity 11 via the first communicating hole 41.
When the refrigerant flows forward, the side of the transverse connecting pipe 52 is a high pressure zone, and the side of the vertical connecting pipe 51 is a low pressure zone. The valve core seat 2 moves downward under the action of a pressure difference of the refrigerant to close the main valve port 441. On this basis, the refrigerant enters into the sleeve upper cavity 43 via the second communicating hole 622, and when the valve needle component 611 opens the valve core valve port 21, the refrigerant in turn enters into the side of the vertical connecting pipe 51 via the valve core valve port 21. In this process, the valve needle component 611 may reciprocate axially with the screw rod 61, thereby regulating an opening of the valve core valve port 21, and achieving the object of flow regulation of the electronic expansion valve.
When the refrigerant flows reversely, the side of the vertical connecting pipe 51 is a high pressure zone, and the side of the transverse connecting pipe 52 is a low pressure zone. The valve core seat 2 moves upward under the action of the pressure difference of the refrigerant, thereby opening the main valve port 441. The refrigerant passes through the main valve port 441, and then flows to the side of the transverse connecting pipe 52 via the first communicating hole 41, thereby achieving the object of one-way communication of a one-way valve.
In the above operation, when the refrigerant flows forward, the valve core seat 2 is arranged in the sleeve 4, and the sleeve 4 is fixedly arranged in the main valve cavity 11, thus the pressure impact on the valve core seat 2 from the high pressure refrigerant is largely borne by the sleeve 4, which significantly reduces the impact on the valve core seat 2, thereby preventing the eccentricity of the valve core seat 2, and avoiding an internal leakage, and ensuring the reliability of the operation of the system. In addition, the refrigerant flows in through the second communicating hole 622 provided on the nut 62. The position of the nut 62 is higher than that of the valve core seat 2, thus the position of the second communicating hole 622 is higher than that of the valve core seat 2, i.e. the refrigerant flows in through the second communicating hole 622 above the valve core seat 2, thereby reducing the impact on the valve core seat 2 from the refrigerant.
Reference is made to FIGS. 6, 7 and 8. FIG. 6 is a schematic view showing the structure of the sleeve of the electronic expansion valve in FIGS. 4 and 5; FIG. 7 is a schematic view showing the structure of the valve core seat of the electronic expansion valve in FIGS. 4 and 5; and FIG. 8 is a partially enlarged view of portion A in FIG. 5.
In the above technical solution, the manner for forming the main valve port 441 may be specifically designed. For example, as shown in FIGS. 4 and 5, the lower end of the sleeve 4 extends into the vertical connecting port 13, and is supported by the vertical connecting port 13. An inner wall of the lower end of the sleeve 4 forms a main valve hole 44, and an aperture at an upper portion of the main valve hole 44 forms the main valve port 441. In such structure, the main valve port 441 is formed on the inner wall of the sleeve 4, and compared to the structure of the main valve port 441 being arranged in the valve seat 1, such structure may facilitate ensuring the concentricity between the valve core seat 2 in the sleeve 4 and the main valve port 441, thereby facilitating improving the sealing performance.
Apparently, the manners for forming the main valve port 441 are not limited in the present application, and as described above, any one of formation structures of the main valve port should be deemed to fall within the scope of the present application as long as the valve core seat 2 movable in the sleeve 4 may close and open the main valve port. For example, the main valve port 441 may be formed by an aperture at an upper end of the vertical connecting port 13 as shown in FIGS. 2 and 3, and in such structure, the lower end of the sleeve 4 does not extend into the vertical connecting port 13, but is supported on an inner wall of the valve seat 1 near the vertical connecting port 13, therefore the valve core seat 2 movable in the sleeve 4 may still open and close the main valve port. Apparently, in such structure, in order to fix the sleeve 4 reliably, the inner wall of the valve seat 1 may be provided with a mounting groove surrounding the main valve port, and the lower end of the sleeve 4 may be fixed in the mounting groove.
In the above technical solution, as shown in FIG. 7, a circumferential outer wall of the lower end of the valve core seat 2 forms a valve core seat sealing portion 22 for opening and closing the main valve port 441. The valve core seat sealing portion 22 cooperates with the main valve port 441 in the sleeve 4 to realize the object of opening and closing.
In the above technical solution, a mounting structure between the lower end of the sleeve 4 and the vertical connecting port 13 may be specifically designed. For example, as shown in FIG. 8, the inner wall of the vertical connecting port 13 is provided with a connecting port stepped portion 131, an outer portion of the lower end of the sleeve 4 is provided with a first sleeve stepped portion 45, and the first sleeve stepped portion 45 is supported on the connecting port stepped portion 131. This structural design expediently achieves the axial support for the sleeve 4, and the reliability of this support is high.
Further, as shown in FIG. 8, the outer portion of the lower end of the sleeve 4 is further provided with a second sleeve stepped portion 46. The electronic expansion valve further includes a vertical connecting pipe 51, and the vertical connecting pipe 51 is sleeved on the lower end of the sleeve 4, and a top end surface of the vertical connecting pipe 51 abuts against the second sleeve stepped portion 46. This structural design expediently achieves installation and fixation between the vertical connecting port 13, the sleeve 4 and the vertical connecting pipe 51, and the reliability of this fixation is high.
In the above technical solution, as shown in FIG. 7, a valve core seat through hole 23 is arranged axially in the valve core seat 2, and an aperture at an upper end of the valve core seat through hole 23 forms the valve core valve port 21. The valve needle component 3 cooperates with the valve core valve port 21 to regulate the opening of the valve core valve port 21, thereby achieving the object of flow regulation of the electronic expansion valve. Furthermore, in this structural design, the valve core seat through hole 23 in the valve core seat 2 may have a large length, such as 5 mm, which allows the valve core seat 2 to be in a long cylindrical shape, thus the noise generated when the refrigerant passes through the valve core seat 2 may be reduced.
In the above technical solution, specific designs may be made. For example, reference is made FIGS. 6, 9 and 9-1, wherein FIG. 9 is a schematic view showing the structure of the nut of the electronic expansion valve in FIGS. 4 and 5; and FIG. 9-1 is a sectional view of the nut in FIG. 9.
As shown in FIG. 9-1, a lower portion of the nut is provided with a nut inner guide hole 621. As shown in FIG. 6, an upper portion of the sleeve 4 is provided with a sleeve outer guide portion 47. As shown in FIGS. 4 and 5, the sleeve outer guide portion 47 is fitted in the nut inner guide hole 621. Further, a lower end of the sleeve outer guide portion 47 is provided with a third sleeve stepped portion 42, and a lower end surface of the nut 62 is further supported on the third sleeve stepped portion 42.
In the above structure, due to the cooperation between the nut inner guide hole 621 and the sleeve outer guide portion 47, a better concentricity between the sleeve 4 and the nut 62 is ensured, which in turn ensures a better concentricity between the sleeve 4 and the screw rod 61. Apparently, in such structure, it is also possible to arrange an sleeve inner guide hole in the upper portion of the sleeve 4 and a nut outer guide portion at an outer portion of the lower end of the nut 62, and to fit the nut outer guide portion in the sleeve inner guide hole.
Further, as shown in FIG. 6, the third sleeve stepped portion 42 extends downwardly in the axial direction to the first sleeve stepped portion 45, and the first communicating hole 41 is further provided on the third sleeve stepped portion 42 in a radial direction of the sleeve 4. In other words, the circumferential side wall of the sleeve 4 is provided with a circumferential protruding portion, a top wall of the circumferential protruding portion forms the third sleeve stepped portion 42, and a bottom wall of the circumferential protruding portion forms the first sleeve stepped portion 45, and the first communicating hole 41 is provided on the circumferential protruding portion. Apparently, such structural design not only facilitates forming the two sleeve stepped portions, but also facilitates providing the first communicating hole 41, and such structure is simple and has a low manufacturing cost.
Moreover, as shown in FIG. 6, a valve core seat guide hole 48, and a main valve hole 44 having an aperture at an upper end thereof to form the main valve port 441, are arranged coaxially inside the sleeve 4. In this structural design, the valve core seat guide hole 48 and the main valve hole 44 may be formed integrally, thereby ensuring a good concentricity therebetween. Meanwhile, the aperture at the upper end of the main valve hole 44 forms the main valve port 441, which ensures a good concentricity between the valve core seat 2 and the main valve port 441. As shown in FIGS. 4 and 5, the valve core seat 2 is axially movable along the valve core seat guide hole 48, thus a good concentricity between the valve core seat 2 and the main valve port 441 may be ensured, which also improves a sealing performance of the valve core seat sealing portion 22 for the main valve port 441, thereby preventing the internal leakage.
In the above technical solutions, specific designs may be further made. For example, reference is made to FIGS. 4, 5, 9 and 10, wherein FIG. 10 is a schematic view showing the structure of a locating plate of the electronic expansion valve in FIGS. 4 and 5.
As shown in FIGS. 4 and 5, the electronic expansion valve further includes a locating plate 8 fixedly arranged in the main valve cavity 11. As shown in FIG. 10, the locating plate 8 is provided with a non-circular profiled hole 81. As shown in FIG. 9, a circumferential outer wall of the lower portion of the nut 62 is provided with a non-circular profiled portion 623 configured to cooperate with the non-circular profiled hole 81 to prevent the nut 62 from rotating. Due to the cooperation between the non-circular profiled hole 81 and the non-circular profiled portion 623, the rotation of the nut 62 may be prevented. It should be noted that, the non-circular profiled hole and the non-circular profiled portion of any structures are deemed to fall in the scope of the present application, since the structure other than a circular hole and a circular portion may prevent the nut 62 from rotating with respect to the locating plate 8, for example, the structure may be triangular, quadrangular or polygonal.
Further, as shown in FIGS. 4, 5 and 10, the locating plate 8 is provided with a third communicating hole 82, and the main valve cavity 11 below the locating plate 8 is in communication with the second communicating hole 622 through the third communicating hole 82. In this structure, when the refrigerant flows forwards, the refrigerant flows through the third communicating hole 82 and then flows into the second communicating hole 622.
Furthermore, as shown in FIGS. 4 and 5, the circumferential outer wall of the lower portion of the nut 62 is provided with a nut stepped portion, and an elastic component 9 is sleeved on the circumferential outer wall of the nut 62, and is elastically compressed between the locating plate 8 and the nut stepped portion. Further, in the above structure, in order to reduce the processing difficulty of the nut 62, the second communicating hole 622 provided on the nut 62 is axially arranged as shown in FIG. 9.
In the present application, as shown in FIG. 4, in the state that the refrigerant flows forwards, the refrigerant flows from the transverse connecting pipe 52 through the third communicating hole 82 on the locating plate 8, the second communicating hole 622 on the nut 62, the sleeve upper cavity 43, and the valve core valve port 21 to the side of the vertical connecting pipe 51. The magnet 71, driven by the magnetic field of the coil, rotates and drives the screw rod 61 to rotate. Since the locating plate 8 restrains the nut 62 from rotating, and the elastic force of the elastic component 9 and the sleeve 4 restrain the nut 62 from axially moving, the screw rod 61 moves up and down by the screw-thread fit with the nut 62, thereby opening and closing the valve core valve port 21 by the valve needle component 611 formed by the lower end of the screw rod 61. When the valve performs a full closing function, the screw rod 61 keeps rotating until the lower end thereof (i.e. the valve needle component 611) contacts the valve core valve port 21, and at this time, the screw rod 61 cannot continue to move downwardly. At this time, the magnet 71 and the screw rod 61 continue rotating, the thrust on the screw rod 61 from the valve core valve port 2 is transferred to the nut 62 through the screw threads on the screw rod 61, and the nut 62 compresses the elastic component 9 to move upwardly, thereby providing an open valve pulse for the product.
An electronic expansion valve according to the present application is described in detail hereinbefore. The principle and the embodiments of the present application are illustrated herein by specific examples. The above description of examples is only intended to help the understanding of the method and idea of the present application. It should be noted that, for the person skilled in the art, a few of modifications and improvements may be made to the present application without departing from the principle of the present application, and these modifications and improvements are also deemed to fall into the scope of the present application defined by the claims.

## Claims

1. An electronic expansion valve, comprising a valve seat, a vertical connecting pipe, and a transverse connecting pipe, the valve seat being provided with a main valve cavity; the electronic expansion valve further comprising a main valve port in communication with the vertical connecting pipe and a valve core seat configured to open and close the main valve port, the valve core seat being provided with a valve core valve port which allows a communication with the vertical connecting pipe; and the electronic expansion valve further comprising a valve needle component configured to open and close the valve core valve port; wherein,
the electronic expansion valve further comprises a drive component, the drive component comprises a screw rod and a nut which cooperates with the screw rod by screw threads, and a lower end of the screw rod forms the valve needle component;
a sleeve is fixed in the main valve cavity, and an upper portion of the sleeve cooperates with the nut; the valve core seat is axially movably arranged in the sleeve, and a lower portion of the screw rod extends into the sleeve to open and close the valve core valve port; and
a circumferential side wall of the sleeve is provided with a first communicating hole close to the main valve port, the nut is provided with a second communicating hole configured to allow the main valve cavity to communicate with a sleeve upper cavity; and in a case that a fluid medium flows from the transverse connecting pipe to the vertical connecting pipe, the valve core seat closes the main valve port, a communication between the first communicating hole and the main valve port is disconnected, and meanwhile the sleeve upper cavity comes in communication with the main valve cavity via the second communicating hole; and in a case that the fluid medium flows from the vertical connecting pipe to the transverse connecting pipe, the valve core seat moves upward to open the main valve port, and the main valve port comes in communication with the main valve cavity via the first communicating hole.

2. The electronic expansion valve according to claim 1, wherein a valve core seat through hole is arranged axially in the valve core seat, and an aperture at an upper end of the valve core seat through hole forms the valve core valve port.

3. The electronic expansion valve according to claim 1, wherein a lower portion of the nut is provided with a nut inner guide hole and an upper portion of the sleeve is provided with a sleeve outer guide portion fitted in the nut inner guide hole; and
a lower end of the sleeve outer guide portion is provided with a third sleeve stepped portion, and a lower end surface of the nut is further supported on the third sleeve stepped portion.

4. The electronic expansion valve according to claim 3, wherein the third sleeve stepped portion extends downwardly in an axial direction, and the first communicating hole is further provided on the third sleeve stepped portion in a radial direction of the sleeve.

5. The electronic expansion valve according to claim 3, wherein a valve core seat guide hole, and a main valve hole having an aperture at an upper end thereof to form the main valve port, are arranged coaxially inside the sleeve.

6. The electronic expansion valve according to claim 1, wherein the electronic expansion valve further comprises a locating plate fixedly provided in the main valve cavity, the locating plate is provided with a non-circular profiled hole, and a circumferential outer wall of a lower portion of the nut is provided with a non-circular profiled portion configured to cooperate with the non-circular profiled hole to prevent the nut from rotating.

7. The electronic expansion valve according to claim 6, wherein the locating plate is provided with a third communicating hole, and the main valve cavity below the locating plate is in communication with the second communicating hole through the third communicating hole.

8. The electronic expansion valve according to claim 6, wherein the circumferential outer wall of the lower portion of the nut is provided with a nut stepped portion, and an elastic component is sleeved on the circumferential outer wall of the nut, and is elastically compressed between the locating plate and the nut stepped portion.

9. The electronic expansion valve according to claim 1, wherein a lower end of the sleeve is supported by the valve seat, and the lower end of the sleeve surrounds the main valve port.

10. The electronic expansion valve according to claim 9, wherein a valve core seat through hole is arranged axially in the valve core seat, and an aperture at an upper end of the valve core seat through hole forms the valve core valve port.

11. The electronic expansion valve according to claim 9, wherein a lower portion of the nut is provided with a nut inner guide hole, and an upper portion of the sleeve is provided with a sleeve outer guide portion fitted in the nut inner guide hole; and
a lower end of the sleeve outer guide portion is provided with a third sleeve stepped portion, and a lower end surface of the nut is further supported on the third sleeve stepped portion.

12. The electronic expansion valve according to claim 11, wherein the third sleeve stepped portion extends downwardly in an axial direction, and the first communicating hole is further provided on the third sleeve stepped portion in a radial direction of the sleeve.

13. The electronic expansion valve according to claim 11, wherein a valve core seat guide hole, and a main valve hole having an aperture at an upper end thereof to form the main valve port, are arranged coaxially inside the sleeve.

14. The electronic expansion valve according to claim 9, wherein the electronic expansion valve further comprises a locating plate fixedly provided in the main valve cavity, the locating plate is provided with a non-circular profiled hole, and a circumferential outer wall of a lower portion of the nut is provided with a non-circular profiled portion configured to cooperate with the non-circular profiled hole to prevent the nut from rotating.

15. The electronic expansion valve according to claim 14, wherein the locating plate is provided with a third communicating hole, and the main valve cavity below the locating plate is in communication with the second communicating hole through the third communicating hole.

16. The electronic expansion valve according to claim 14, wherein the circumferential outer wall of the lower portion of the nut is provided with a nut stepped portion, and an elastic component is sleeved on the circumferential outer wall of the nut, and is elastically compressed between the locating plate and the nut stepped portion.

17. The electronic expansion valve according to claim 9, wherein the valve seat is provided with a vertical connecting port for mounting the vertical connecting pipe, and the lower end of the sleeve extends into the vertical connecting port and is supported by the vertical connecting port; and an inner wall of the lower end of the sleeve forms a main valve hole, and the main valve port is formed by an aperture at an upper portion of the main valve hole.

18. The electronic expansion valve according to claim 17, wherein a circumferential outer wall of a lower end of the valve core seat forms a valve core seat sealing portion for opening and closing the main valve port.

19. The electronic expansion valve according to claim 17, wherein an inner wall of the vertical connecting port is provided with a connecting port stepped portion, an outer portion of the lower end of the sleeve is provided with a first sleeve stepped portion, and the first sleeve stepped portion is supported on the connecting port stepped portion.

20. The electronic expansion valve according to claim 19, wherein the outer portion of the lower end of the sleeve is further provided with a second sleeve stepped portion, the vertical connecting pipe is sleeved on the lower end of the sleeve, and a top end surface of the vertical connecting pipe abuts against the second sleeve stepped portion.