CN111379863A

CN111379863A - Flow control valve

Info

Publication number: CN111379863A
Application number: CN201811628947.1A
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Climate and Appliance Controls Group Co Ltd
Current assignee: Zhejiang Sanhua Commercial Refrigeration Co ltd
Priority date: 2018-12-28
Filing date: 2018-12-28
Publication date: 2020-07-07

Abstract

The invention discloses a flow control valve, which comprises a valve body component, a guide component and a valve core component, and is characterized in that the valve body component comprises a first fluid port and a second fluid port, the guide component is fixedly connected with the valve body component, and the valve core component can be in clearance sliding fit relative to the guide component; the valve core component comprises a valve core body and a flow blocking piece, the valve core body comprises a cylindrical section, the flow blocking piece is arranged on the cylindrical section, the flow blocking piece comprises a flow blocking part and an edge part fixedly connected with the valve core body, the flow blocking part is at least partially positioned in the middle area of the flow blocking piece, the valve core component comprises an upper cavity positioned on the upper side of the flow blocking part and a lower cavity positioned on the lower side of the flow blocking part, the upper cavity is communicated with the lower cavity through a communicating channel, when the valve core body is abutted to the valve port of the flow control valve, the lower cavity is not communicated with the first fluid port, and the lower cavity is communicated with the second fluid port.

Description

Flow control valve

Technical Field

The invention relates to the technical field of fluid control, in particular to a flow control valve.

Background

In the field of fluid control technology, the requirement on the operation performance of a flow control valve is higher and higher, and fig. 10 is a schematic structural diagram of a flow control valve of the background art. As shown in fig. 10, the flow control valve includes a valve body part 01, a valve core part 02, a first connection pipe 03, and a second connection pipe 04. When the valve core part 02 is separated from the valve port part, the high-pressure fluid flowing in from the first connecting pipe 03 may form a large vortex at the lower end of the valve core part 02 near the center line of the valve body part 01 and the nearby position, and the high-pressure fluid may enter the cavity above the valve core part 02 from the inside of the valve core part 02, thereby affecting the valve opening reliability of the flow control valve.

Disclosure of Invention

The object of the present invention is to provide a flow control valve in which the reliability of opening and closing the valve is improved when a fluid enters from a first fluid port.

The flow control valve comprises a valve body component, a guide component and a valve core component, wherein the valve body component comprises a first fluid port and a second fluid port, the guide component is fixedly connected with the valve body component, and the valve core component can be in clearance sliding fit relative to the guide component; the valve core component comprises a valve core body and a flow blocking piece, the valve core body comprises a cylindrical section, the flow blocking piece is arranged on the cylindrical section, the flow blocking piece comprises a flow blocking part and an edge part fixedly connected with the valve core body, at least part of the flow blocking part is positioned in the middle area of the flow blocking piece, the valve core component comprises an upper cavity positioned on the upper side of the flow blocking part and a lower cavity positioned on the lower side of the flow blocking part, and the upper cavity is communicated with the lower cavity through a communicating channel; when the valve core body is abutted against the valve port of the flow control valve, the lower cavity is not communicated with the first fluid port, and the lower cavity is communicated with the second fluid port.

The flow control valve provided by the invention has the advantages that the valve core component comprises the valve core body and the flow blocking part, the flow blocking part comprises the flow blocking part, at least part of the flow blocking part is positioned in the middle area of the flow blocking part, the valve core component comprises an upper cavity positioned on the upper side of the flow blocking part and a lower cavity positioned on the lower side of the flow blocking part, the upper cavity and the lower cavity are communicated through the communicating channel, and when fluid enters from the first fluid port, the reliability of opening and closing the flow control valve can be improved.

Drawings

Fig. 1 is a schematic structural diagram of a first flow control valve provided by the present invention in a fully open state;

fig. 2 is a schematic structural diagram of a first flow control valve provided in the present invention in a fully closed state;

FIG. 3 is a top view of a baffle of the flow control valve shown in FIG. 1;

FIG. 4 is a schematic illustration of a second embodiment of a baffle of the flow control valve of FIG. 1;

FIG. 5 is a schematic illustration of a third embodiment of a baffle member of the flow control valve of FIG. 1;

FIG. 6 is a schematic structural diagram of a second embodiment of a flow control valve provided in the present invention;

FIG. 7 is a schematic illustration of a valve cartridge member of the flow control valve of FIG. 6;

FIG. 8 is a perspective view of a baffle of the flow control valve of FIG. 6;

FIG. 9 is a graph of the flow area of the valve core body versus the effective blocking area of the flow stop;

fig. 10 is a schematic structural diagram of a flow control valve in the background art.

Detailed Description

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

It should be noted that the upper and lower terms are defined as the components are located at the positions shown in the drawings of the specification, and are only used for clarity and convenience of technical solution. It is to be understood that the directional terms used herein are not intended to limit the scope of the claims.

The "axial direction" referred to herein means a direction from top to bottom or from bottom to top along the paper surface, that is, an axial direction of the magnetic rotor and the valve body; as used herein, "radial" refers to a direction perpendicular to the axial direction.

The fixed connection in the invention can be a direct fixed connection of two parts, and can also be a fixed connection of two parts through other parts, namely an indirect fixed connection of two parts.

Fig. 1 is a schematic structural diagram of a first flow control valve provided by the present invention in a fully open state, and fig. 2: fig. 3 is a plan view of a flow blocking member of the flow control valve shown in fig. 1.

As shown in fig. 1, the flow control valve of the present embodiment includes a valve body member 10, a guide member 20, a valve core member 30, a transmission member 40, and a coil member 50.

The valve body part 10 comprises a valve body 15, a valve cover body 16 and a valve base 17, wherein the valve body 15 and the valve cover body 16 are fixedly welded, the valve body 15 and the valve base 17 are fixedly welded, and the coil part 50 is sleeved on the periphery of the valve body part 10 and is fixedly connected with the valve body part 10 through a support 60.

The valve body 15 has a substantially cylindrical structure, and specifically includes an upper cylinder portion 15a, an intermediate cylinder portion 15b, and a lower cylinder portion 15 c. The valve housing 16 is welded to the outer wall of the middle cylinder 15b of the valve body 15, the upper cylinder 15a of the valve body 15 extends into the valve housing, and the side wall of the lower cylinder 15c is provided with a first fluid port 11.

The valve base 17 has a substantially annular structure, and the valve base 17 forms a valve port portion with which the spool member 30 can abut or separate. The valve base 17 has an axial through hole, the lower end of which forms the second fluid port 12.

A transmission member (not shown) is arranged in the valve chamber, the transmission member comprising a nut 43. The lower end of the nut 43 extends into the core member 30. The nut 43 can convert the rotation of the screw rod 42 into an axial movement to drive the valve core part 30 to move axially, and the guide part 20 and the valve body part 10 are directly welded and fixedly connected, although they can be indirectly fixed through other connecting parts. The guide member 20 includes a substantially cylindrical guide sleeve 21, and the outer wall of the valve core member 30 is in clearance sliding fit with respect to the inner wall of the guide sleeve 21; the spool portion 30 can abut against or separate from a valve port portion of the flow control valve to close or open the flow control valve. When the spool member 30 is partially separated from the valve port, the first fluid port 11 and the second fluid port 12 are communicated through the valve port, and when the spool member 30 is abutted against the valve port, the first fluid port 11 and the second fluid port 12 are not communicated. The flow control valve can realize bidirectional flow, and fluid can flow in from the first fluid port 11 and flow out from the second fluid port 12, and can also flow in from the second fluid port 12 and flow out from the first fluid port 11.

The flow control valve comprises a back pressure chamber 13 positioned above a valve core component 30, the valve core component 30 comprises a valve core body 31 and a flow blocking piece 32, and the valve core body 31 and the flow blocking piece 32 are fixedly connected, for example, by welding or interference fit. The valve body 31 is substantially cylindrical, and the nut 43 can drive the valve body 31 to move axially. The size of the back pressure chamber 13 varies during the axial movement of the spool member 30. A sealing assembly 100 is provided between the outer wall of the spool body 31 and the inner wall of the guide member 20, the sealing assembly 100 ensuring that the first fluid port 11 of the flow control valve is not in communication with the back pressure chamber 13 and the second fluid port 12 when the flow control valve is in the closed state. The valve core body 31 includes a cylindrical section 311, and the flow blocking member 32 includes a flow blocking portion 321 and an edge portion 323 fixedly connected to the valve core body 31. The baffle 321 is at least partially located in the middle region of the baffle 32, and the "baffle" and "edge" are divided according to the functions of different parts of the baffle 32, and do not exclude the case where the edge also functions as a baffle. The valve element member 30 includes an upper chamber 301 located above the flow blocking portion 321 and a lower chamber 302 located below the flow blocking portion 321, the upper chamber 301 and the back pressure chamber 13 are always communicated, the upper chamber 301 and the lower chamber 302 are communicated through a communication passage 322, when the valve element 31 abuts against the valve port portion of the flow control valve, the lower chamber 302 is not communicated with the first fluid port 11, and the lower chamber 302 is communicated with the second fluid port 12.

In the flow control valve of the present embodiment, by providing the flow blocking member 32, the flow blocking member 32 includes the flow blocking portion 321 and the edge portion 323, the flow blocking portion 321 is at least partially located in the middle region of the flow blocking member 32, the valve core member 30 includes the upper chamber 301 located on the upper side of the flow blocking portion 321 and the lower chamber 302 located on the lower side of the flow blocking portion 321, and the upper chamber 301 and the lower chamber 302 are communicated through the communication channel 322, so that when the valve core body 31 is separated from the valve port portion of the flow control valve, the fluid entering from the first fluid port 11 will be gathered below the flow blocking portion to form a high pressure region, the flow blocking portion can at least partially block the high pressure fluid from directly rushing into the upper chamber 301 of the valve core member 30, so that the high pressure fluid is dispersed around the position of the flow blocking portion 321, the pressure will be reduced, and the fluid with the reduced pressure enters the upper chamber 301 of the valve core member 30, thus, the downward fluid pressure received by the valve body member 30 can be reduced, the resistance when the valve body member 30 moves upward to open the valve can be reduced, and the reliability of opening the valve of the flow control valve when the fluid enters from the first fluid port can be improved, and the reliability of closing the valve of the flow control valve when the fluid enters from the first fluid port can be improved.

As shown in fig. 2 and 3, the flow blocking member 32 is substantially in the shape of a circular plate, the flow blocking member 32 is disposed inside the valve core 31, an edge 323 of the flow blocking member 32 is welded to an inner wall of the valve core 31 or is in interference fit with the inner wall of the valve core 31, and the flow blocking portion 321 is substantially disposed in the middle of the flow blocking member 31. The term "intermediate" as used herein means that, for example, when the baffle has a substantially disk shape, the baffle 321 is located in a certain region extending in a radial direction from the central axis of the baffle. The communication channels 322 are communication holes provided on the outer periphery of the flow blocking portion 321, and as a specific design, the number of the communication holes may be designed as needed, for example, fig. 3 shows a structure when the number of the communication holes is four, so that the stress of the valve core member 30 can be more balanced. Further, in order to more balance the fluid pressure received by the valve body member 30, the communication holes may be provided so as to be circumferentially symmetrical with respect to the center axis of the cylindrical section 311.

Under the condition that the structure is not changed, the flow blocking piece can be deformed and designed to have the same function as the flow blocking piece. Fig. 4 is a schematic structural view of a second embodiment of a flow blocking member in the flow control valve of fig. 1. As shown in fig. 4, the flow blocking member 32A is substantially in a cross-shaped plate structure, an edge portion 323A of the flow blocking member 32A is welded and fixed to or in interference fit with an inner wall of the valve body 31, the flow blocking portion 321A is disposed substantially in the middle of the flow blocking member 32A, the flow blocking member 32A includes two or more legs 324A, one end of each leg 324A is connected to the flow blocking portion 321A, and the other end of each leg 324A is disposed separately as the edge portion 323A. Each edge 323A is fixedly connected to the inner wall of the valve body 31A. In the embodiment shown in fig. 4, the number of legs is four, and as used herein "middle" refers to the area defined by the dashed line shown in the figure, i.e. the largest circular area centered on the center of the baffle. A communication passage 322A is formed between each adjacent leg 324A and the inner wall of the spool body 31A. The number of the communication passages 322A may be four as shown in fig. 4, but is not limited to four. In order to make the fluid pressures received by the spool member 30 more balanced, the communication passages 322A may be arranged to be circumferentially symmetrical with respect to the central axis of the cylindrical section 311.

Fig. 5 is a schematic structural view of a third embodiment of a flow blocking member in the flow control valve of fig. 1. As shown in fig. 5, the flow blocking member 32B is substantially in the shape of a strip plate, and includes a first circular arc portion 331B and a second circular arc portion 332B welded and fixed to the valve body 31, the first circular arc portion 331B and the second circular arc portion 332B serve as edge portions of the present embodiment, and the flow blocking member 32B further includes a first side wall portion 333B connecting one end of the first circular arc portion 331B and one end of the second circular arc portion 332B, and a second side wall portion 334B connecting the other end of the first circular arc portion 331B and the other end of the second circular arc portion 332B. The first and second

side wall portions

333B, 334B and the valve body 31 form a communication passage 322B therebetween. In order to make the fluid pressures received by the spool member 30 more balanced, the communication passages 322B may be arranged to be circumferentially symmetrical with respect to the central axis of the cylindrical section 311.

Further, in the flow control valve shown in fig. 1, two flow blocking members may be provided: the first flow blocking piece and the second flow blocking piece. That is, two flow blocking members 32 shown in fig. 3, two flow blocking members 32A shown in fig. 4, or two flow blocking members 32B shown in fig. 5 are provided. The second flow stop is arranged on the underside of the first flow stop and a filter element 34 is arranged between the two flow stops.

The cartridge component 30 includes a balanced flow path that includes the lower chamber 302, the communication channel (322 or 322A or 322B), and the upper chamber 301. The arrangement of the balance flow path is beneficial to the balance of the upper and lower pressures of the valve core component 30 and the reduction of the pressure difference applied to the valve core component 30 in the axial movement process.

Fig. 6 is a schematic structural diagram of a flow control valve according to a second embodiment of the present invention. Fig. 7 is a schematic structural view of a valve core member of the flow control valve of fig. 6. Fig. 8 is a perspective view of a flow stop of the flow control valve of fig. 7. The following mainly describes the details of this embodiment in relation to the present invention.

As shown in fig. 6, the flow rate control valve of the present embodiment includes a valve body member 10C, a guide member 20C, and a spool member 30C, a transmission member 40C, and a drive member (not shown).

The valve body part 10C comprises a valve body 15C, the valve body 15C is fixed with the guide part 20C, and the driving part is in transmission connection with the transmission part 40C.

The valve body 15C is generally Y-shaped in configuration, and the valve body 15C is provided with a first fluid port 11C and a second fluid port 12C. The valve body 15C has a valve port portion.

A transmission member (not shown) is disposed in the valve chamber, the transmission member including a nut 43C. The lower end of the nut 43C extends into the valve body member 30C and is screwed.

The guide member 20C is directly welded or screwed to the valve body member 10C, but may be indirectly fixed by other connecting members. The guide part 20C comprises a guide section 21C, and the outer wall of the valve core part 30C can be in clearance sliding fit relative to the inner wall of the guide section 21C; the spool member 30C can abut against or separate from a valve port portion of the flow control valve to close or open the flow control valve. When the spool member 30C is separated from the valve port portion, the first fluid port 11C and the second fluid port 12C communicate through the valve port portion, and when the spool member 30C abuts against the valve port portion, the first fluid port 11C and the second fluid port 12C do not communicate. The flow control valve can perform bidirectional flow, and fluid can flow in from the first fluid port 11C and flow out from the second fluid port 12C, or flow in from the second fluid port 12C and flow out from the first fluid port 11C.

The flow control valve includes a back pressure chamber 13C above the spool member 30C, and the spool member 30C includes a spool body 31C, a flow blocking piece 32C, and a connection cover 33C. The valve core body 31C and the flow blocking piece 32C are welded and fixed, and the flow blocking piece 32C and the connecting cover 33C are fixedly connected through threads. The flow blocking piece 32C comprises a cylindrical portion 302C and a plate portion 303C, the plate portion 303C comprises a flow blocking portion 321C and an edge portion 323C fixedly connected with the valve core body 31C, the flow blocking portion 321 is at least partially located in the middle area of the flow blocking piece 32C, a communication channel 322C is arranged between the flow blocking portion 321C and the edge portion 323C, and the external thread of the nut 43C can be matched with the internal thread of the cylindrical portion 302C to enable the nut 43C to drive the valve core member 30C to move axially.

During the axial movement of the spool member 30C, the size of the back pressure chamber 13C is varied. The valve core body 31C is substantially cylindrical, the transmission component 40C can drive the valve core body 31C to axially move, a sealing assembly 100C is arranged between the outer wall of the valve core body 31C and the inner wall of the guide sleeve 21C, and when the flow control valve is closed, the sealing assembly 100C ensures that the first fluid port 11C of the flow control valve is not communicated with the back pressure cavity 13C and the second fluid port 12C. The spool body 31C includes a cylindrical section 311C. As shown in fig. 7 and 8, the communication passage 322C is provided between the flow blocking portion 321C and the edge portion, the valve core member 30C includes an upper chamber 301C located on the upper side of the flow blocking portion 321C and a lower chamber 305C located on the lower side of the flow blocking portion 321C, the upper chamber 301C communicates with the back pressure chamber 13C, and the upper chamber 301C and the lower chamber 305C communicate with each other through the communication passage 322C. When the valve body 31C abuts against the valve port portion, the lower chamber 305C does not communicate with the first fluid port 11C, and the lower chamber 305C communicates with the second fluid port 12C.

Due to the structural design, the flow blocking piece 32C can also function as a connecting piece, namely, the connecting cover 33C and the valve core body 31C are connected. Wherein the connection cover 33C includes an accommodation chamber 331C, and the accommodation chamber 331C is a part of the upper chamber 301C. The nut 43C includes a small diameter section 431C and a large diameter section 432C disposed below the small diameter section 431C, and the large diameter section 432C is at least partially located in the receiving cavity 331C. The large diameter section 432C can cooperate with the connection cap 33C to enable the nut 43C to carry the core member 30C to move axially. The coupling cap 33C couples the nut 43C and the flow blocking member 32C, and provides a receiving space for the lower end of the nut 43C.

Further, in addition to the above-mentioned solution, a filter member 34C is further disposed below the connecting passage 322C of the connecting cover 33C to filter the fluid entering the upper chamber 301C through the communicating passage 322C.

In this embodiment, the balanced flow path of the flow control valve includes a lower chamber 305C, a communication passage 322C, and an upper chamber 301C. The function of the balance flow path is the same as that in the first embodiment, and the description thereof will not be repeated. In order to make the fluid pressures received by the spool member 30C more balanced, the communication passages 322C may be arranged to be circumferentially symmetrical with respect to the central axis of the cylindrical section 311C.

The advantageous effects of the flow control valve of this embodiment are the same as those of the previous embodiment, and the description thereof will not be repeated.

As can be seen from the two embodiments, the technical solution of the present application can be applied to valves with different structures as long as the object of the present invention can be achieved.

In the flow blocking member of each of the foregoing embodiments, further structural refinement may be made. Fig. 9 is a relationship diagram of the through-flow diameter of the spool body and the radially largest circular diameter defined by the flow blocking portion with the central axis of the spool body as the center. As shown in fig. 9, if the diameter of the largest circle in the radial direction defined by the flow blocking portion with the central axis of the valve body as the center is set to B and the minimum through-flow diameter of the lower chamber is set to a, B ≧ 0.2A, the flow blocking portion can be used as much as possible to reduce the pressure difference applied to the valve body member 30, and the valve opening and closing reliability of the flow control valve can be improved when the fluid enters from the first fluid port.

The flow control valve comprises a valve core body and a flow blocking piece, wherein the valve core body comprises a cylindrical section, the flow blocking piece comprises a middle flow blocking part and an edge part fixedly connected with the valve core body, the flow blocking part is at least partially positioned in the middle area of the flow blocking piece, the valve core part comprises an upper cavity positioned on the upper side of the flow blocking part and a lower cavity positioned on the lower side of the flow blocking part, the upper cavity is communicated with the lower cavity through a communicating channel, the pressure difference of the valve core part is reduced, the pressure difference resistance of the valve core part in the valve opening action process is reduced, and the valve opening and valve closing reliability of the flow control valve is improved when fluid enters from a first fluid port.

It should be noted that, in addition to the embodiments described in detail above, the flow control valve in this patent application may also be a proportional control valve of flow regulation type, an electronic expansion valve, or an electromagnetic valve of switch type, or an electric control valve.

The flow control valve provided by the present invention is described in detail above. The principles and embodiments of the present invention have been described herein using specific examples, which are presented only to assist in understanding the method and its 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. A flow control valve comprising a valve body member, a guide member and a valve core member, wherein the valve body member comprises a first fluid port and a second fluid port, the guide member is fixedly connected to the valve body member, and the valve core member is in clearance sliding fit with respect to the guide member; the valve core component comprises a valve core body and a flow blocking piece, the valve core body comprises a cylindrical section, the flow blocking piece is arranged on the cylindrical section, the flow blocking piece comprises a flow blocking part and an edge part fixedly connected with the valve core body, at least part of the flow blocking part is positioned in the middle area of the flow blocking piece, the valve core component comprises an upper cavity positioned on the upper side of the flow blocking part and a lower cavity positioned on the lower side of the flow blocking part, and the upper cavity is communicated with the lower cavity through a communicating channel; when the valve core body is abutted against the valve port of the flow control valve, the lower cavity is not communicated with the first fluid port, and the lower cavity is communicated with the second fluid port.

2. The flow control valve according to claim 1, wherein the flow control valve comprises a transmission component, the transmission component comprises a nut, the nut can drive the valve core body to move axially, a sealing assembly is arranged between an outer wall of the valve core body and an inner wall of the guide component, the edge part is fixedly connected with the inner wall of the valve core body, the communication channel is a communication hole arranged on the flow blocking member, and the communication hole is arranged on the periphery of the flow blocking part.

3. The flow control valve according to claim 1, wherein the flow control valve comprises a transmission part, the transmission part comprises a nut, the nut can drive the valve core to move axially, a sealing assembly is arranged between the outer wall of the valve core body and the inner wall of the guide part, the flow blocking part comprises more than two support legs, the support legs are fixedly connected with the inner wall of the valve core body, and the adjacent support legs and the inner wall of the valve core body form the communication channel.

4. The flow control valve of claim 1, wherein the flow control valve includes a transmission member, the transmission part comprises a nut which can drive the valve core to move axially, a sealing component is arranged between the outer wall of the valve core body and the inner wall of the guide part, the flow blocking piece comprises a first arc part and a second arc part which are fixedly connected with the valve core body, the edge part comprises the first arc part and the second arc part, the flow blocking piece further comprises a first side wall part connecting one end of the first arc part with one end of the second arc part, and a second side wall part connecting the other end of the first arc part with the other end of the second arc part, the communication channels are formed between the first side wall portion and the inner wall of the valve core body and between the second side wall portion and the inner wall of the valve core body.

5. The flow control valve according to any one of claims 1 to 4, wherein the flow blocking portion has a substantially plate shape, the communication passage is substantially symmetrically arranged with respect to a central axis of the cylindrical segment, and a filter member is provided on a lower side of the communication passage.

6. The flow control valve of claim 1, wherein the valve core member further comprises a connecting cover, the connecting cover is fixedly connected with the flow blocking member, and the nut is capable of cooperating with the connecting cover to drive the valve core member to move axially.

7. The flow control valve according to claim 6, wherein the valve core body is welded to the flow blocking member, the flow blocking member includes a cylindrical portion and a plate portion, the plate portion includes the flow blocking portion and the communication channel, the connection cover includes an accommodating cavity, the upper cavity includes the accommodating cavity, the nut includes a small diameter section and a large diameter section disposed below the small diameter section, the large diameter section is at least partially located in the accommodating cavity, and the large diameter section is capable of cooperating with the connection cover to enable the nut to drive the valve core member to axially move.

8. The flow control valve according to claim 6, wherein the valve core body is welded to the flow blocking member, the flow blocking member includes a cylindrical portion and a plate portion, the plate portion includes the flow blocking portion and the communication channel, the connection cover includes an accommodating cavity, the upper cavity includes the accommodating cavity, the nut includes a small diameter section and a large diameter section disposed below the small diameter section, the large diameter section is at least partially located in the accommodating cavity, the large diameter section is capable of cooperating with the connection cover to enable the nut to drive the valve core member to axially move, and a filter member is disposed below the communication channel.

9. The flow control valve according to any one of claims 1 to 4 and 6 to 8, wherein B is larger than or equal to 0.2A when the diameter of the radially largest circle defined by the flow blocking portion and centered on the central axis of the spool body is B and the minimum flow-through diameter of the lower chamber is a.

10. The flow control valve according to any one of claims 1 to 4 and 6 to 8, wherein the flow control valve comprises a balancing flow passage and a back pressure chamber communicating with the balancing passage, and the balancing flow passage comprises the lower chamber, the communicating passage and the upper chamber.

11. The flow control valve according to claim 1, wherein the flow blocking member is welded to the valve core body, the flow control valve further includes a transmission member, the transmission member includes a nut, the nut can drive the valve core body to move axially, a sealing assembly is disposed between an outer wall of the valve core body and an inner wall of the guide member, the flow control valve includes a balance flow channel and a back pressure chamber communicated with the balance flow channel, the balance flow channel includes the lower chamber, the communication channel and the upper chamber, the flow blocking member is substantially plate-shaped, a diameter of a radial maximum circle defined by the flow blocking portion and centered on a central axis of the valve core body is set as B, a minimum through-flow diameter of the lower chamber is set as a, and B is ≧ 0.