CN113446402A

CN113446402A - Electronic expansion valve

Info

Publication number: CN113446402A
Application number: CN202010230014.8A
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-28

Abstract

The invention aims to provide an electronic expansion valve, wherein a shell connector is matched with a step part of a valve seat, the shell connector is sleeved on a step longitudinal part, the shell connector is formed by lathing and has better planeness, the central axis of the shell connector is not easy to deviate than the central axis of the valve seat, a coil fixing frame is not positioned between a matching surface and the step transverse part, and the relative deviation of the central axis of the shell connector relative to the central axis of the valve seat is not easy to be influenced by the planeness of the coil fixing frame, so that the coaxiality of the shell connector and the valve seat is easy to control.

Description

Electronic expansion valve

[ technical field ] A method for producing a semiconductor device

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

[ background of the invention ]

Fig. 9 shows a structure of a typical electronic expansion valve, which has a valve seat 201 ', a positioning piece 2051 ', a valve plate 2052 ', a cover-shaped housing 209 ', and the positioning piece 2051 ' and the valve plate 2052 ' are stacked on the valve seat 2052 ' and then welded and fixed, and then the cover-shaped housing 209 ' with a downward opening is assembled and welded to the valve plate 2052 '.

Generally, the positioning piece 2051 'is a stamping piece, and compared with a machined part, the surface flatness of the positioning piece is poor, the positioning piece 2051' and the valve plate 2052 'are sequentially pressed into the valve seat 2052', then the cover-shaped shell 209 'is welded to the valve plate 2052', the cover-shaped shell 209 'is easily affected by the positioning piece 2051', and the coaxiality of the cover-shaped shell 209 'and the valve seat 201' is controlled with certain difficulty.

[ summary of the invention ]

The invention aims to provide an electronic expansion valve which can reduce the situation that a valve needle or a screw rod is inclined relative to a central axis of a valve body.

In order to realize the purpose, the following technical scheme is adopted:

an electronic expansion valve comprises a valve seat assembly and a shell, wherein the valve seat assembly comprises a valve seat, a coil fixing frame and a shell connecting body, the coil fixing frame is formed by adopting a stamping process, and the shell connecting body is formed by adopting machining; the valve seat assembly further comprises a first solder flow-through and a second solder flow-through;

the valve seat comprises a valve seat step part, the valve seat step part comprises a step transverse part and a step longitudinal part, the step longitudinal part comprises a first step longitudinal part and a second step longitudinal part, and the outer diameter of the first step longitudinal part is larger than that of the second step longitudinal part.

The shell connecting body is sleeved on the step longitudinal part, the first solder circulation part is positioned between the shell connecting body and the step longitudinal part, the first solder circulation part is provided with solder so as to enable the shell connecting body to be fixedly connected with the valve seat, the shell connecting body comprises a matching surface, and the matching surface and the step transverse part are oppositely arranged;

the coil fixing frame is sleeved on the step longitudinal part, the second solder circulation part is positioned between the coil fixing frame and the step longitudinal part, and solder is arranged on the second solder circulation part to enable the coil fixing frame to be welded and fixed with the valve seat;

in the axial direction, the housing connector is located above the coil fixing frame, and the coil fixing frame is not located between the matching surface and the step transverse portion.

According to the electronic expansion valve provided by the invention, the shell connector is matched with the step part of the valve seat, the shell connector is sleeved on the step longitudinal part, the shell connector is formed by lathing, so that the flatness is better, the central axis of the shell connector is not easy to deviate compared with the central axis of the valve seat, the coil fixing frame is not positioned between the matching surface and the step transverse part, and the relative deviation of the central axis of the shell connector relative to the central axis of the valve seat is not easy to be influenced by the flatness of the coil fixing frame, so that the coaxiality of the shell connector and the valve seat is easy to control.

[ description of the drawings ]

Fig. 1 is a sectional view of an electronic expansion valve provided in the present invention;

FIG. 2 is a schematic structural view of the nut assembly of FIG. 1;

FIG. 3 is a cross-sectional view of a valve needle screw assembly fitted with a fixed rod, spring and steel ball;

FIG. 4 is a cross-sectional schematic view of a valve seat assembly of the first embodiment provided by the present invention;

FIG. 5 is a schematic view of the valve seat of FIG. 4;

FIG. 6 is a top view of the coil mount of FIG. 4;

FIG. 7 is a schematic structural diagram of the housing connector of FIG. 4;

FIG. 8 is a cross-sectional schematic view of a valve seat assembly of a second embodiment of the present invention;

fig. 9 shows a structure of an electronic expansion valve according to a typical prior art.

Wherein the figures include the following reference numerals:

a valve seat screw rod component 1; a screw rod 11; a lead screw outer fitting portion 111; a screw thread portion 112; a lead screw accommodating portion 113; a lead screw abutting portion 114; a lead screw inner fitting portion 115; a valve needle 12; a needle main body portion 121; a needle diameter expanding portion 122; a nut 2; a nut screw guide 21; a nut threaded portion 22; a large diameter portion 221; a small diameter portion 222; a nut needle guide portion 23; a nut fitting portion 24; a nut groove portion 25; nut pressure not 26; a nut flow hole portion 27; a valve seat 3; a valve seat fitting portion 31; a flow-through part 32; a valve port 34; a valve seat step portion 35; a step lateral portion 351; a stepped longitudinal portion 352; a first stepped longitudinal portion 3521; a second stepped longitudinal portion 3522; a first seat recess 36; a valve port seal portion 341; a linker 4; a fixing rod 5; a spring 6; a steel ball 7; a magnetic rotor 8; a housing 9; a housing connector 10; a mating face 101; a housing connector recess 102; a housing connector inner step 103; a first inner wall portion 1031; a second inner wall portion 1032; a rear surface portion 1033; a housing connector outer step 104; a first outer wall portion 1041; a second outer wall portion 1042; an outer surface portion 1043; a stop assembly 20; a spiral guide 201; a slip ring 202; a stopper rod 203; a first piping section 30; a second piping portion 40; a coil fixing bracket 50; a coil mount recess 501; a coil holder body portion 502; a plate body recess 503; a first cavity A; a second cavity B; a balance section C; a first solder flow portion D; and a second solder flow portion E.

[ detailed description ] embodiments

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1-3, fig. 1 is a sectional view of an electronic expansion valve according to the present invention, fig. 2 is a schematic structural view of a nut assembly in fig. 1, and fig. 3 is a sectional view of a valve needle screw assembly equipped with a fixing rod, a spring and a steel ball.

In one embodiment, the present invention provides an electronic expansion valve comprising a valve body and a stator coil (not shown). The valve body comprises a valve needle screw rod assembly 1, a nut 2, a valve seat 3, a magnetic rotor 8, a shell 9 and the like. The stator coil of the electronic expansion valve is connected with the driving controller, after the driving controller is electrified, a pulse driving signal is sent to the stator coil, the stator coil generates a periodically changing magnetic field, and therefore the magnetic rotor 8 of the electronic expansion valve is driven to rotate forwards or reversely, the magnetic rotor 8 is fixedly connected with the lead screw 11, and the magnetic rotor 8 can synchronously drive the lead screw 11 to rotate when rotating.

A screw rod thread part 112 is arranged on a screw rod 11 of the valve needle screw rod component 1, and the screw rod thread part 112 is of an external thread structure; the nut 2 is a hollow structure, which is provided with a nut thread part 22, the nut thread part 22 is an internal thread structure, the screw thread part 112 and the nut thread part 22 are meshed, and the nut 2 is fixedly installed on the valve seat 3, so that the magnetic rotor 8 moves in a rotating manner, and simultaneously, due to the thread pair structures on the screw rod 11 and the nut 2, the screw rod 11 moves in a displacement manner along the axial direction, and the valve needle 12 of the valve needle screw rod component 1 can be driven to realize the opening and closing actions of the valve port 34.

The first pipe connecting portion 30 and the second pipe connecting portion 40 are fixedly mounted on the valve seat 3, and the first pipe connecting portion 30 and the second pipe connecting portion 40 are used as an inflow or outflow passage of a fluid medium of an electronic expansion valve and are generally used for connecting with a system pipeline when the electronic expansion valve is mounted in a refrigerating and heating system such as an air conditioner. The valve seat 3 is provided with a valve port 117 at a substantially central position of the second pipe connecting portion 40, and a valve port sealing portion 1171 is provided on an upper side edge of the valve port 117.

In the present embodiment, the nut 2 is made of plastic, and is formed by injection molding of a resin material, and the connecting body 4 is fixedly connected to the nut 2. Specifically, the connector 4 may be placed in a mold, and then a molten resin material may be injected into the mold, and after the resin material is cooled and solidified, the nut assembly in which the nut 2 and the connector 4 are fixed together may be removed from the mold.

The nut 2 provided in the present embodiment has a substantially hollow structure, and includes a nut screw guide 21, a nut screw portion 22, and a nut needle guide 23, in which the nut screw guide 21 is higher than the nut screw portion 22, and the nut needle guide 23 is lower than the nut screw portion 22 in the axial direction.

Correspondingly, the valve needle screw assembly 1 provided by the embodiment comprises the valve needle 12 and the screw 11, and the valve needle 12 and the screw 11 are in limit connection, that is, the valve needle 12 can move within a certain range, but cannot be separated from the limit of the screw 11.

After the nut 2 and the valve needle screw rod assembly 1 are engaged through threads, the nut screw rod guide part 21 is in clearance fit with the screw rod outer matching part 111, and the nut valve needle guide part 23 is in clearance fit with the valve needle main body part 121.

Through the arrangement, the valve needle screw rod assembly 1 is driven by the magnetic rotor 8 to rotate, when the valve needle screw rod assembly 1 moves in the axial direction, the screw rod 11 can be guided and righted by the nut screw rod guide part 111, and the valve needle 12 can be guided and righted by the valve needle screw rod guide part 21, so that the valve needle screw rod assembly 1 is not prone to deflection, and the working stability of the electronic expansion valve can be improved.

In addition, when the valve needle screw assembly 1 is assembled, the screw outer matching part 111 and the nut screw guide part 21 which are positioned at the periphery of the screw 11 can also provide guidance before the nut screw part 22 and the screw part 112 are meshed, so that the assembly of the valve needle screw assembly 1 is more convenient, the condition that the electronic expansion valve fails or the service life is reduced due to the deflection of the valve needle screw assembly 1 and the nut 2 during the assembly can be reduced, and the service life and the reliability of the electronic expansion valve can be improved.

In addition, in the nut 2 provided in the present embodiment, the internal structure of the nut 2 is substantially defined by the mandrel inside the mold, and therefore, the direction of releasing from the mold is from one end of the nut screw guide 21 to one end of the nut pin guide 23, so that the internal diameter of the hollow portion inside the nut 2 can only be maintained in the same or reduced state from the releasing direction inside the mold, otherwise the nut 2 cannot be released from the mold; the nut 2 of the present embodiment is provided, wherein the nut thread portion 22 includes a large diameter portion 221 and a small diameter portion 222, the large diameter portion 221 is a position where the inner diameter of the nut thread portion 22 is the largest, the small diameter portion 111 is a position where the inner diameter of the nut thread portion 22 is the smallest, the inner diameter of the nut screw guide 21 is not smaller than the inner diameter of the large diameter portion 221, and the inner diameter of the nut needle guide 23 is not larger than the inner diameter of the small diameter portion 222, so that the nut 2 can be smoothly released from the mold.

In the present embodiment, the screw 11 includes a screw receiving portion 113, a screw abutting portion 114, and a screw inner engaging portion 115, the screw abutting portion 114 is located between the screw receiving portion 113 and the screw inner engaging portion 115, an inner diameter of the screw receiving portion 113 is larger than an inner diameter of the screw inner engaging portion 115, the valve needle 12 is inserted into the screw 11, the valve needle 11 includes a valve needle expanding portion 122, and the valve needle expanding portion 122 is located substantially at an upper end of the valve needle 11 and can abut against the screw abutting portion 114 to prevent the valve needle 12 from coming off the screw 11.

When the axial projection of the lead screw expanding portion 122 is circular, the outer diameter thereof is smaller than the inner diameter of the lead screw accommodating portion 113, so that the valve needle 12 can be inserted into the inner cavity of the lead screw 11 from the upper end of the lead screw 11, the lead screw accommodating portion 113 and the valve needle expanding portion 122 are in clearance fit, when the valve needle 12 moves within the limited range of the lead screw 11, the lead screw accommodating portion 113 can provide guidance for the valve needle 12, and the stability of the valve needle 12 in moving relative to the lead screw 11 can be improved.

Meanwhile, the outer diameter of the valve needle expanding portion 122 is larger than the inner diameter of the screw rod inner matching portion 115, when the valve needle 12 is about to pass through the screw rod 12, the valve needle expanding portion 122 can abut against the screw rod abutting portion 114 to limit the valve needle 12 from passing out of the screw rod 11, in addition, the valve needle main body portion 121 is in clearance fit with the screw rod inner matching portion 115, when the valve needle 12 moves up and down, the screw rod inner matching portion 115 can provide guidance for the valve needle 12, the stability of the valve needle 12 in relative to the movement of the screw rod 11 and the coaxiality of the valve needle 12 and the central axis of the valve port 34 can be improved, and the eccentric wear of the valve needle 12 can be reduced.

The valve needle main body part 121 and the valve needle expanding part 122 are guided by the screw rod 11 at the same time, so that the stability of the valve needle 12 in movement relative to the screw rod 11 can be further improved, and the coaxiality of the valve needle 12 and the central axis of the valve port can be more easily ensured.

In addition, the electronic expansion valve provided by this embodiment further includes a fixing rod 5, a spring 6 and a steel ball 7, specifically, the fixing rod 5 is inserted into the lead screw accommodating portion 113 and is fixedly connected to the lead screw 11, the steel ball 7 and the spring 6 are disposed in the space inside the lead screw accommodating portion 113, the steel ball 7 is located above the spring 6, the upper end of the spring 6 abuts against the steel ball 7, the steel ball 7 abuts against the fixing rod 5, the lower end of the spring 6 abuts against the upper surface of the valve needle diameter expanding portion 122, and the valve needle 12 is subjected to the elastic load of the spring 6.

The fixed rod 5 is fixedly connected with a threaded guide rail 201, a sliding ring 202 is matched with the threaded guide rail 201, namely, the sliding ring slides between the annular guide rails of the threaded guide rail 201, the upper end of the shell 9 is fixedly connected with a stop rod 203, the cross section of the stop rod 203 is approximately in a horizontally inverted L shape, the up-down moving range of the screw rod 11 can be limited by the matching of the stop rod 203, the sliding ring 202 and the threaded guide rail 201, and the stop rod 203, the sliding ring 202 and the threaded guide rail 201 form a stop assembly of the electronic expansion valve.

In addition, the electronic expansion valve provided by the present embodiment further includes a first cavity a and a second cavity B, the first cavity a is substantially defined by the valve seat 3, the nut 2, the housing connection body 10 and the housing 9, and the second cavity B is substantially defined by the valve seat 3 and the nut 2. Of course, it is understood that the first cavity a and the second cavity B may be defined differently from the present embodiment, for example, the valve seat 3 is directly and fixedly connected with the housing 9, and in this case, the valve seat 3, the nut 2 and the housing 9 substantially define the first cavity a.

In the electronic expansion valve provided by the present embodiment, the nut 2 includes a nut fitting portion 24, and the nut fitting portion 24 is located below the connecting body 4; the valve seat 3 comprises a valve seat matching part 31, the nut matching part 24 penetrates through the valve seat matching part 31, namely, at the moment, the nut matching part 24 and the valve seat matching part 31 form an intersection in the axial direction along the projection of the central axis of the electronic expansion valve.

The valve seat 3 is provided with a flow portion 32, and the flow portion 32 may be externally inserted through a through hole or a notch of the valve seat 3. A balance portion C is provided between the nut fitting portion 24 and the valve seat fitting portion 31, the balance portion C communicates with the flow portion 32, and the first cavity a and the second cavity B can communicate with each other through the balance portion C and the flow portion 32.

In this way, when the refrigerant circulates through the electronic expansion valve, the pressures in the first cavity a and the second cavity B can be conducted and balanced through the balance part C and the circulation part 32, and the working stability of the electronic expansion valve is improved.

Specifically, the balance portion C may be implemented in a variety of different manners, for example, the nut 2 is provided with a nut groove portion 25, the nut groove portion 25 is approximately a groove-shaped structure formed by radially recessing the surface of the nut 2, the nut groove portion 25 is communicated with the circulating portion 32, and the refrigerants in the first cavity a and the second cavity B can be conducted and balanced through the nut groove portion 25; for another example, the valve seat 3 is provided with the valve seat recess portion 22, the valve seat recess portion 33 is substantially a groove-like structure formed by radially recessing the surface of the valve seat 3, the valve seat recess portion can communicate with the flow portion 32, and the pressures in the first chamber a and the second chamber B can be conducted and balanced by the valve seat recess portion 33; for another example, the nut fitting portion 24 and the valve seat fitting portion 31 are loosely fitted, and the gap may communicate with the flow portion 32, and the pressures in the first chamber a and the second chamber B may be balanced by the gap conduction between the nut fitting portion 24 and the valve seat fitting portion 31.

It is to be noted that the three conditions of the nut groove portion 25 and the valve seat groove portion 33 and the clearance fit of the nut groove portion 25 and the valve seat fitting portion 31 do not conflict, and for example, when the valve seat 3 is provided with the valve seat fitting groove portion 33, the nut 2 is provided with the nut groove portion 25, and the valve seat fitting portion 31 and the nut fitting portion 24 are simultaneously provided in the clearance fit, the pressures in the first chamber a and the second chamber B can be conducted and balanced at all. The first cavity a and the second cavity B are conducted in a balanced manner, and only one of the valve seat groove portion 33, the nut groove portion 25, the valve seat matching portion 31 and the nut matching portion 24 in clearance fit, that is, more than one of them, needs to be provided.

In addition, the electronic expansion valve provided in the present embodiment further includes a nut pressure portion 26 and a nut flow hole portion 27, specifically, the nut pressure portion 26 is located above the nut needle guide portion 23 in the axial position, and below the nut screw portion 22, the inner diameter of the nut pressure portion 26 is larger than the outer diameter of the needle main body portion 121, and at this time, a certain space is formed between the nut pressure portion 26 and the needle main body portion 122. Further, the nut flow hole portion 27 includes inner and outer surfaces penetrating the nut 2, and the nut flow hole portion 27 communicates the nut pressure portion 26 and the above balance portion C.

With the above arrangement, the pressure inside the nut 2 can be kept balanced with the pressure outside the nut 2 through the nut flow hole portion 27, so as to improve the operation stability of the electronic expansion valve.

Referring to fig. 4-7, fig. 4 is a cross-sectional view of a valve seat assembly, fig. 5 is a structural view of the valve seat assembly of fig. 4, fig. 6 is a top view of a coil fixing frame of fig. 4, and fig. 7 is a structural view of a housing connector of fig. 4.

Referring to fig. 4, the electronic expansion valve of the present invention includes a valve seat assembly, which generally includes a valve seat 3, a coil fixing frame 50 and a housing connector 10, wherein the coil fixing frame 50 is used for connecting a stator coil, for example, a positioning frame of the stator coil is provided with a protruding positioning portion, and the coil fixing frame 50 is provided with a notch matching with the positioning portion, so as to fix the coil and the valve body.

Referring to fig. 6, the coil fixing frame 50 is formed by a stamping process, but the coil fixing frame 50 formed by the stamping process cannot ensure the surface flatness thereof, and the housing connecting body 10 is formed by lathing, so that the lathed housing connecting body 10 has better flatness compared with the coil fixing frame 50 formed by the stamping process.

It should be noted that, the coil fixing frame 50 described in this specification is formed by using a stamping process, which means that a stamping process is used in the forming process of the coil fixing frame 50, and is not limited to the stamping process used in the forming process of the coil fixing frame 50, but the upper and lower surfaces are not formed by lathing, and the housing connecting body 10 is formed by lathing, which means that the housing connecting body 10 is formed by lathing.

Referring to fig. 5 in particular, the valve seat 3 includes a valve seat step 35, the valve seat step 35 includes a step transverse portion 351 and a step longitudinal portion 352, the step transverse portion 351 is a substantially horizontal portion of the valve seat step 35, the step longitudinal portion 352 is a substantially vertical portion of the valve seat step 35, the step longitudinal portion 352 includes a first step longitudinal portion 3521 and a second step longitudinal portion 3522, the first step longitudinal portion 3521 and the second step longitudinal portion 3522 are respectively connected to two ends of the step transverse portion 351, and an outer diameter of the first step longitudinal portion 3521 is greater than an outer diameter 3522 of the second step longitudinal portion.

Of course, it is not required that the step longitudinal portion 352 is completely vertical, and when the step longitudinal portion 352 is slightly offset from the vertical direction, the outer diameters of the first step longitudinal portion 3521 and the second step longitudinal portion 3522 may be the outer diameters of the connection portions of the step longitudinal portion 3521 and the step lateral portion 351, and of course, the offset of the step longitudinal portion 352 from the vertical direction should be within ± 10 °, and similarly, it is not required that the step lateral portion 351 is completely horizontal, and the offset of the step lateral portion 351 from the horizontal direction should be within ± 10 °.

Referring to fig. 7, the housing connector 10 is welded to the second step longitudinal portion 3522 of the valve seat 3, in the axial direction, the first step longitudinal portion 3521 is located below the second step longitudinal portion 3522, at this time, the housing connector 10 is located above the coil fixing frame 50, the housing connector 10 includes a mating surface 101, the mating surface 101 is approximately the bottom surface of the housing connector 10, at this time, the mating surface 101 and the step transverse portion 351 are oppositely disposed, and the mating surface 101 is located above the step transverse portion 351, that is, the step transverse portion 351 can be used as a limiting surface of the housing connector 10, the housing connector 10 can be flatly connected to the valve seat 3 under the action of the step transverse portion 351, so as to ensure the coaxiality of the housing connector 10 and the valve seat 3.

The coil fixing frame 50 is welded to the first step longitudinal portion 3521, and at this time, the upper surface of the coil fixing frame 50 is welded and fixed to the mating surface 101 of the housing connecting body 10. The coil fixing frame 50 is not located between the mating face 101 and the stepped lateral portion 351.

The valve seat assembly arranged as above can be fixedly connected into a whole by furnace welding, and then the outer shell 9 can be welded and fixed with the outer shell connecting body 10 by laser welding or argon arc welding and the like.

Through the electronic expansion valve arranged as above, the housing connector 10 is matched with the valve seat step 35, that is, before the valve seat 3 and the housing connector 10 are welded, the housing connector 10 is sleeved on the second step longitudinal portion 3522, the inner wall of the housing connector 10 is matched with the outer wall of the second step longitudinal portion 3522, the mating surface 101 of the housing connector 10 can be abutted against the step transverse portion 351 of the valve seat step 35, because the housing connector 10 is formed by lathing, the housing connector 10 has better flatness, the central axis of the housing connector 10 is not prone to be deviated from the central axis of the valve seat 3, or the degree of deviation of the central axis of the housing connector 10 relative to the central axis of the valve seat 3 is smaller, and the coil fixing frame 50 is not located between the mating surface 101 and the step transverse portion 351, the relative deviation of the central axis of the housing connector 10 relative to the central axis of the valve seat 3 is not prone to be affected by the flatness of the coil fixing frame 50, thereby making the housing connecting body 10 more coaxial with the valve seat 3.

During furnace welding, solder can be placed below the coil fixing frame 50, after the valve seat 3 is fixedly connected with the first connecting pipe 30 and the second connecting pipe 40, and welding rings are respectively placed at the connection positions of the first connecting pipe 30 and the second connecting pipe 40 and the valve seat 3 for furnace welding operation, so that the housing connecting body 10, the coil fixing frame 50, the first connecting pipe 30 and the second connecting pipe 40 are respectively welded and fixed with the valve seat 3.

Referring to fig. 5, in order to facilitate the flow of the solder, the valve seat 3 of the present embodiment includes a first valve seat recess 36, the first valve seat recess 36 is substantially a groove structure formed along the surface of the valve seat 3, and when the furnace welding operation is performed, the solder flows into the first valve seat recess 36 under the capillary effect, so that the housing connecting body 10 and the valve seat 3 are welded and fixed.

Referring to fig. 7, a housing connector recessed portion 102 may be disposed on a surface of the housing connector 10, which is sleeved on the valve seat 3, the housing connector recessed portion 102 is substantially a structure formed by a recessed inner wall surface of the housing connector 10, and when performing a furnace welding operation, solder flows into the housing connector recessed portion 102 under a capillary effect, so that the housing connector 10 is welded and fixed to the valve seat 3; alternatively, the housing connector 10 is in clearance fit with the stepped longitudinal portion 352, and during the furnace welding operation, the solder flows into the clearance between the housing connector 10 and the stepped longitudinal portion 352 by capillary effect, so that the housing connector 10 is welded to the valve seat 3 more firmly.

The first solder flow portion D includes at least one of the first valve seat recess 36, the housing connection body recess 102, and the gap between the housing connection body 10 and the stepped vertical portion 352, so that the housing connection body 10 is fixedly connected to the valve seat 3, and at least a part of the first solder flow portion D is filled with solder.

Similarly, the coil fixing frame 50 may be provided with a coil fixing frame recess 501, the coil fixing frame recess 501 is a structure formed by a recess of a surface of the coil fixing frame 50, which is matched with the step longitudinal portion 352, or a recess structure formed by a recess of the first step longitudinal portion 3521 and a recess of the second valve seat, which is formed along a surface of the valve seat 3, or a gap of the coil fixing frame 50 and the step longitudinal portion 352 is matched, and when performing a furnace welding operation, solder may flow into the gap between the coil fixing frame 50 and the step longitudinal portion 352 under a capillary effect, so as to weld the coil fixing frame 50 and the valve seat 3 more firmly, in this embodiment, the coil fixing frame 50 includes a protruding point structure protruding toward a direction away from the coil fixing frame 50 at an axial inner edge thereof, and the protruding point structure may be matched with the step longitudinal portion 352 to achieve pre-positioning of the coil fixing frame 352 and the valve seat 3, the subsequent welding operation of the coil fixing frame 352 and the valve seat 3 is conveniently performed, and at this time, the portion of the axial inner edge of the coil fixing frame 50 which is not protruded is the coil fixing frame recess 351.

The second solder flow portion E includes at least one of the second valve seat recess, the coil fixing frame recess 501, and a gap between the coil fixing frame 50 and the step longitudinal portion 352, so that the coil fixing frame 50 is fixedly connected to the valve seat 3, and at least a part of the second solder flow portion E is filled with solder, so as to weld the coil fixing frame 50 to the valve seat 3.

In addition, the housing connecting body 10 provided in this embodiment is further provided with a housing connecting body outer step portion 104, the housing connecting body outer step portion 104 may be formed by machining, and includes a first outer wall portion 1041, a second outer wall portion 1042 and an outer surface portion 1043, an outer diameter of the first outer wall portion 1041 is larger than an outer diameter of the second outer wall portion 1042. The open end of the housing 9 is sleeved on the second outer wall 1042, the opening of the second outer wall can abut against the outer shape portion 1043, the outer shape portion 1043 can serve as a limiting surface of the housing 9, and then the housing 9 and the housing connector 10 are welded and fixed. Since the outer surface portion 1043 can be formed by lathing, the outer surface portion 1043 has a better flatness, and thus the coaxiality of the housing 9 and the housing connector 10 can be easily controlled.

The second outer wall portion 1042 can provide a guide for the housing 9, and the open end of the housing 9 can be abutted against the outer surface portion 1043, so that the housing 9 is not easily deflected relative to the housing connecting body 10, the coaxiality of the housing 9 and the housing connecting body 10 is easily ensured, and the condition or degree of reduced coaxiality of the housing 9 and the valve seat 3 caused by the deviation of the central axis of the housing 9 relative to the central axis of the housing connecting body 10 is reduced.

The coil holder 50 further includes a coil holder body 502 and a plate body recess 503, and the plate body recess 503 is substantially a structure formed by being recessed in the axial direction of the coil holder body 502, and the structure can be formed together when the coil holder 50 is press-molded.

The plate body recess 503 is provided to allow solder flowing out from between the mating surface 101 of the case connection body 10 and the upper surface of the coil fixing frame 50 to flow into the plate body recess 503, thereby reducing the risk of solder flowing out to the valve body.

The housing connection body 10 may be provided with a chamfered portion 105, the chamfered portion 105 being a chamfer of the upper end surface and the inner wall of the housing connection body 10, and by the above arrangement, the solder flowing out from the housing connection body 10 and the second stepped vertical portion 3522 may be located at the chamfered portion 105, thereby reducing the risk of the solder flowing out to the valve body.

The working principle of the electronic expansion valve provided by the embodiment is as follows:

when the flow of the electronic expansion valve is gradually reduced from the maximum opening, the magnetic rotor 8 starts to rotate after receiving the magnetic field change of the stator housing, and simultaneously, the valve needle screw rod assembly 1 fixedly connected with the magnetic rotor 8 also synchronously rotates, because the nut 2 is fixedly connected with the valve seat 3 through the connecting body 4, and the screw rod thread part 112 is meshed with the nut thread part 22, the screw rod 11 starts to move axially downwards at the moment.

At this time, the needle 12 is movably connected to the screw 11, that is, the needle 12 is acted by the spring force, and the needle expanding portion 122 thereof abuts against the screw abutting portion 114, and when the screw 11 moves downward, the needle 12 also moves downward simultaneously.

As the stroke of the downward movement of the valve needle screw assembly 1 gradually increases, the valve needle 12 starts to abut against the valve port sealing portion 341 of the valve port 34, and the flow rate is closed.

When the screw rod 11 further moves downwards, the valve needle 12 abuts against the valve port 34 at this time, the valve needle 12 cannot further move downwards along with the screw rod 11, at this time, the valve needle expanding portion 121 and the screw rod abutting portion 114 are changed from an abutting state to a separated state, the spring 6 is further compressed, and along with the increase of the compression amount of the spring 6, the pressure of the valve needle 12 on the valve port 34 is gradually increased, so that a sufficient valve closing force of the valve needle 12 is ensured.

During the axial movement of the screw 11, the spiral guide 201 and the sliding ring 202 also demonstrate relative movement, i.e. the sliding ring 202 will move circumferentially around the fixed rod along the guide of the spiral guide 201 due to one end of the sliding ring 202 contacting the stop rod 203, when the sliding ring 202 rotates to the position-limiting part of the upper end of the spiral guide 201, the sliding ring 202 is limited to further rotate, so that the valve needle screw assembly 1 is also limited to further downward movement, the spring 6 is compressed to the maximum position, and the pressure of the valve needle 12 on the valve port 34 is maximum.

Example 2

For convenience of description of the present embodiment, the same reference numerals are used for components of the present embodiment having the same structure and the same function as those of the first embodiment, and the description of the components of the first embodiment is also applicable to the second embodiment, and the differences from the first embodiment will be described in detail below.

Referring specifically to FIG. 8, FIG. 8 is a cross-sectional view of a valve seat assembly according to a second embodiment of the present invention;

in this embodiment, the housing connecting body 10 is provided with the housing connecting body inner step portion 103, the housing connecting body inner step portion 103 can be formed by lathing, and includes a first inner wall portion 1031, a second inner wall portion 1032 and a back surface portion 1033, the first inner wall portion 1031 is welded and fixed with the first step longitudinal portion 3521, the second inner wall portion 1032 is welded and fixed with the second step longitudinal portion 3522, the back surface portion 1033 is welded and fixed with the step transverse portion 351, the coil fixing frame 50 is welded and fixed with the second step longitudinal portion 3522, and the upper surface of the coil fixing frame 50 is welded and fixed with the lower surface of the housing connecting body 10; at this time, the valve seat step portion 35 is formed in a substantially inverted step shape, and the first step vertical portion 3521 is positioned above the second step vertical portion 3522 in the axial direction.

Through the arrangement, the valve seat step part 35 is matched with the inner step part 103 of the shell connector, that is, before the valve seat 3 and the connected housing body 10 are welded, the first inner wall 1031 is engaged with the first stepped vertical portion 3521, the second inner wall 1032 is engaged with the second stepped vertical portion 3522, the back surface 1033 is engaged with the stepped horizontal portion 351, because the housing connecting body 10 is formed by lathing, it has better flatness, the central axis of the housing connecting body 10 is not easy to deviate from the central axis of the valve seat 3, or the degree of deviation of the central axis of the housing connecting body 10 relative to the central axis of the valve seat 3 is smaller, and the coil fixing frame 50 with relatively low flatness is not located between the matching surface 101 and the step transverse portion 351, and the central axis of the housing connector 10 is not easily influenced by the coil fixing frame 50 relative to the central axis of the valve seat 3, so that the housing connector 10 and the valve seat 3 have relatively good coaxiality.

It should be noted that, the terms of orientation such as up, down, left, right, etc. mentioned in the specification are all introduced for convenience of description by taking the drawings of the specification as a reference; and ordinal numbers such as "first," "second," etc., in the names of the elements are also introduced for convenience of description and do not imply any limitation as to the order of the elements, both direct and indirect, as noted in this specification, including both direct and indirect.

The electronic expansion valve provided by the invention is described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the core concepts of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. The electronic expansion valve is characterized by comprising a valve seat assembly and a shell (9), wherein the valve seat assembly comprises a valve seat (3), a coil fixing frame (50) and a shell connecting body (10), the coil fixing frame (50) is formed by adopting a stamping process, and the shell connecting body (10) is formed by adopting turning; (ii) a

The valve seat (3) includes a valve seat step portion (35), and the valve seat step portion (35) includes a step lateral portion (351) and a step longitudinal portion (352).

The outer shell connecting body (10) is sleeved on the step longitudinal part (352), a first solder flowing part (D) is formed between the outer shell connecting body (10) and the step longitudinal part (352), and at least part of the first solder flowing part (D) is filled with solder;

the housing connecting body (10) comprises a matching surface (101), the matching surface (101) is arranged opposite to the step transverse part (351), and at least part of the space between the matching surface (101) and the step transverse part (351) is filled with solder so that the housing connecting body (10) is directly welded and fixed with the valve seat (3);

the coil fixing frame (50) is sleeved on the step longitudinal portion (352), a second solder circulating portion (E) is formed between the coil fixing frame (50) and the step longitudinal portion (352), and at least part of the second solder circulating portion (E) is filled with solder.

2. An electronic expansion valve according to claim 1, wherein the valve seat (3) comprises a first valve seat recess (36), the first solder flow portion (D) comprises the first valve seat recess (36), and/or the housing connection body (10) comprises a housing connection body recess (102), the first solder portion (D) comprises the first connection body recess (102).

3. An electronic expansion valve according to claim 1, wherein the housing connection body (10) is clearance fitted with the stepped longitudinal portion (352), and the first solder portion (D) comprises a clearance between the housing connection body (10) and the stepped longitudinal portion (352).

4. An electronic expansion valve according to claim 1, wherein the valve seat (3) comprises a second valve seat recess and the second solder flow-through (E) comprises the second valve seat recess, and/or wherein the coil holder (50) comprises a coil holder recess (501) and the second solder flow-through (E) comprises the coil holder recess (501).

5. An electronic expansion valve according to claim 1, wherein the coil holder (50) is clearance fitted with the stepped longitudinal portion (352), and the second solder portion (E) comprises a clearance between the coil holder (50) and the stepped longitudinal portion (352).

6. An electronic expansion valve according to any of claims 1-5, wherein the stepped longitudinal portion (352) comprises a first stepped longitudinal portion (3521) and a second stepped longitudinal portion (3522), the outer diameter of the first stepped longitudinal portion (3521) being larger than the outer diameter of the second stepped longitudinal portion (3522), the housing connection body (10) being welded to the second stepped longitudinal portion (3522), the coil fixation frame (50) being welded to the first stepped longitudinal portion (351), the first stepped longitudinal portion (3521) being located below the second stepped longitudinal portion (3522) in axial position.

7. The electronic expansion valve according to any one of claims 1-5, wherein the stepped longitudinal portion (352) comprises a first stepped longitudinal portion (3521) and a second stepped longitudinal portion (3522), the outer diameter of the first stepped longitudinal portion (3521) is larger than the outer diameter of the second stepped longitudinal portion (3522), the housing connector (10) comprises a housing connector inner stepped portion (103), the housing connector inner stepped portion (103) comprises a first inner wall portion (1031), a second inner wall portion (1032) and a back surface portion (1033), and the back surface portion (1033) is welded and fixed with the stepped transverse portion (351);

the first inner wall part (1031) and the first stepped longitudinal part (3521) are welded and fixed, and the second inner wall part (1032) and the second stepped longitudinal part (3522) are welded and fixed;

the coil fixing frame (50) is welded and fixed with the second step longitudinal portion (3522), and the first step longitudinal portion (3521) is located above the second step longitudinal portion (3522) in the axial position.

8. The electronic expansion valve according to any of claims 1-7, wherein the housing connection body (10) comprises a housing connection body outer step portion (104), the housing connection body outer step portion (104) comprising a first outer wall portion (1041), a second outer wall portion (1042) and an outer surface portion (1043), the outer diameter of the first outer wall portion (1041) being larger than the outer diameter of the second outer wall portion (1042);

the inner wall of the shell (9) is fixedly welded with the second outer wall part (1042).

9. The electronic expansion valve according to any of claims 1-7, wherein the coil holder (50) comprises a coil holder body portion (502) and a plate body recess portion (503), and the plate body recess portion (503) is substantially formed by axially recessing the coil holder body portion (502).

10. An electronic expansion valve according to claim 1, wherein the housing connection body (10) comprises a chamfered portion (105), the chamfered portion (105) being a chamfer of an upper end face and an inner wall of the housing connection body (10).