Valve for improving flow stability and mass flow controller applying same

Abstract

The invention relates to the field of valves, in particular to a valve capable of improving flow stability and a mass flow controller applying the valve. The valve comprises a flow inlet block, a lower sealing piece, an upper sealing piece, a horizontal guide elastic piece and a control rod. The flow inlet block is provided with a flow inlet and a containing cavity. The lower sealing piece is located in the containing cavity and provided with a plurality of inflow channels, the lower sealing piece is further provided with a matched inclined face, and the matched inclined face inclines outwards from bottom to top; the upper sealing piece is fixedly connected with the inflow block and provided with a plurality of outflow channels, the outflow channels and the inflow channels are staggered, the horizontal guide elastic piece comprises a circular ring part and at least three protruding parts, the circular ring part is arranged outside the lower sealing piece in a sleeving mode at intervals, and all the protruding parts are evenly distributed in the circumferential direction of the circular ring part and protrude out of the circular ring part inwards in the radial direction. And all the convex parts are in contact with the matching inclined surface so as to apply pre-tightening force to the lower sealing piece. It can be guaranteed that the lower sealing piece and the upper sealing piece are kept horizontal in the opening process and after the valve is opened, and therefore stable flow is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of valves, and in particular to a valve for improving flow stability and a mass flow controller using the valve. Background Art

[0002] A mass flow controller (MFC) is a device used to control gas flow and plays an important role in the semiconductor manufacturing process. MFC can accurately control the flow of gas to ensure stability and repeatability in the semiconductor production process. In order to maintain a stable flow, it is necessary to control the valve opening of the MFC to be stable.

[0003] The existing normally closed valve of the mass flow controller (specifically Figure 1 As shown in the figure, the inlet block 1 includes an inlet port 11 and an accommodating chamber 12; the lower seal 2 is located in the accommodating chamber 12, and is provided with a plurality of inlet channels 21 connected to the inlet port 11; the upper seal 3 is fixedly connected to the inlet block 1, and is provided with a plurality of outlet channels 31; the inlet of the outlet channel 31 is staggered with the outlet of the inlet channel 21; the spring structure is sleeved on the lower seal 2, and a pre-tightening force is applied to the lower seal 2, so that the lower seal 2 is normally in close contact with the upper seal 3; since the inlet of the outlet channel 31 of the upper seal 3 is staggered with the outlet of the inlet channel 21 of the lower seal 2, the gas will be cut off by the upper seal 3 after flowing in through the inlet block 1. That is, the valve is normally closed. The spring structure is a thin sheet with a hollow hole in the middle, which can be a single spring or a double spring. Figure 1 What is shown is a double spring sheet, which is an upper spring sheet 7 and a lower spring sheet 8.

[0004] When the valve needs to be opened, the control rod 5 will extend along the axial direction through the central channel 34 of the upper seal 3 until it contacts the lower seal 2, so that a gap is formed between the upper seal 3 and the lower seal 2 for gas flow. The ideal gap state is that the gaps are of equal height at all positions, such as Figure 2 As shown in (a), the gap is formed when the lower seal 2 is always level with the upper seal 3 during the descent process. However, in actual use, the lower seal 2 will tilt when being pushed downward by the control rod 5, as shown in FIG. Figure 2 As shown in (b) in .

[0005] As the valve gradually opens wider and the tilt angle increases, it becomes more difficult to maintain the position of the valve. This is because the gas will continue to flow through the gap in the opening, causing the force of the gas on the lower seal 2 to change in real time, causing the lower seal 2 to swing along the contact point between the control rod 5 and the lower seal 2, thereby causing unstable valve flow, unstable instrument control, and reduced equipment performance.

[0006] Therefore, it is urgent to solve the above technical problems. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a valve with improved flow stability, which can ensure that the lower seal and the upper seal remain level during and after the valve is opened, thereby ensuring flow stability.

[0008] In order to solve the above technical problems, the technical solution of the present invention is: a valve for improving flow stability, comprising: An inlet block is provided with an inlet port and a containing cavity; A lower sealing member is located in the accommodating cavity and is provided with a plurality of inlet channels communicating with the inlet port. The lower sealing member is also provided with a matching inclined surface, and the matching inclined surface is inclined outward from bottom to top; The upper sealing member is fixedly connected to the inlet block and is provided with a plurality of outlet channels, wherein the inlet of the outlet channel is staggered with the outlet of the inlet channel. A horizontal guide spring piece, comprising a circular ring portion and at least three protrusions, wherein the circular ring portion is sleeved outside the lower seal with a gap therebetween, all the protrusions are evenly distributed along the circumference of the circular ring portion, and protrude inwardly from the circular ring portion along the radial direction of the circular ring portion, all the protrusions are in contact with the matching inclined surface to apply a pre-tightening force to the lower seal, and the lower seal is normally in close contact with the upper seal under the action of the pre-tightening force; The control rod acts on the lower sealing member and is used to push the lower sealing member to overcome the pre-tightening force and move downward to form a gap between the lower sealing member and the upper sealing member.

[0009] In order to further improve the elastic supporting force of the valve on the upper seal and improve the flow stability, the valve also includes a cooperative sealing spring. The cooperative sealing spring is sleeved outside the lower seal and is located below the horizontal guide spring. It acts on the lower seal and is used to cooperate with the horizontal guide spring to apply a pre-tightening force to the lower seal.

[0010] In order to facilitate the installation and positioning of the horizontal guide spring and the cooperative sealing spring, the peripheral wall of the accommodating cavity is provided with an upper step surface and a lower step surface; wherein, The lower end surface of the annular portion is placed on the upper step surface, and the outer ring cooperates with the peripheral wall of the accommodating cavity located above the upper step surface to achieve positioning; The lower end surface of the cooperative sealing elastic sheet is placed on the lower step surface, and the outer periphery cooperates with the peripheral wall of the accommodating cavity located above the lower step surface and / or the central hole cooperates with the lower sealing member to achieve positioning.

[0011] Furthermore, the lower sealing member comprises a first-stage column, a second-stage column and a third-stage column which are arranged in sequence from bottom to top and whose diameters increase step by step; wherein, A plurality of first inlet channels that penetrate the first-stage cylinder, the second-stage cylinder and the third-stage cylinder in the axial direction are arranged at the middle position of the lower sealing member, and a plurality of second inlet channels that penetrate only the third-stage cylinder in the axial direction are arranged at the edge position, and the first inlet channels and the second inlet channels both serve as the inlet channels; The cooperative sealing spring is sleeved outside the first-stage column, the upper end surface of which abuts against the lower surface of the second-stage column, and has a hollow structure for fluid to flow through; The matching inclined surface is arranged on the third-level column.

[0012] Furthermore, the matching inclined surface surrounds the outer circumference of the second inlet channel.

[0013] Furthermore, all the first inlet channels and all the second inlet channels are arranged in a circle.

[0014] In order to further improve the stability of the fluid flowing through the valve, the upper sealing member is provided with buffer grooves at the position of the circle formed by the first inlet channel and at the position of the circle discharged by the second inlet channel.

[0015] Furthermore, a plurality of outflow channels are arranged along the circumferential direction of the upper sealing member and extend along the radial direction of the upper sealing member.

[0016] A communication groove is provided on the upper sealing member at a position offset from the inlet channel, and the communication groove extends from the lower end surface of the upper sealing member to the corresponding outlet channel.

[0017] Furthermore, the upper sealing member is provided with a central channel for the control rod to pass through, and all the inlet channels are staggered from the central channel.

[0018] The invention also relates to a mass flow controller comprising a valve for improving flow stability.

[0019] After adopting the above technical solution, the present invention adopts a horizontal guide spring sheet, and each protrusion of the horizontal guide spring sheet can be deflected and deformed along the axial direction. The horizontal guide spring sheet contacts the lower seal only through its protrusion, and the corresponding contact point of the lower seal is a matching bevel. Therefore, after actual assembly, there is a line contact or point contact between the matching bevel of the horizontal guide spring sheet and the lower seal, and three points determine a plane, and the design of at least three protrusions can ensure that there are at least three point contacts between the two, and the overall contact is good. The horizontal guide spring sheet also has a certain pre-deformation, that is, the lower seal is subjected to an upward force. Due to the existence of the matching bevel of the lower seal, the forces at the three contact points can be decomposed into axial components and radial components. At least three radial components will cause the lower seal to produce a slight displacement along the radial direction, and make the lower seal better fit the upper seal, while the axial components will tightly attach the lower seal to the upper seal. Moreover, as the control rod extends downward to open the lower seal, the axial force generated by the horizontal guide spring sheet will also increase, maintaining the stability of the position of the lower seal, and the circumferentially balanced radial force can also ensure that the lower seal is parallel to the upper seal. Therefore, the present invention effectively improves the flow stability of the valve without reducing the flow capacity of the structure, greatly optimizing the performance degradation caused by the defects of the traditional structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a traditional valve; Figure 2 for Figure 1 Schematic diagram of the structure of the lower seal in an ideal state and an inclined state when the valve is opened; Figure 3 It is a structural schematic diagram of a valve for improving flow stability of the present invention; Figure 4 It is a schematic structural diagram of the horizontal guide spring piece of the present invention; Figure 5 It is a schematic structural diagram of the horizontal guide spring piece of the present invention in contact with the matching inclined surface of the lower sealing member; Figure 6 It is a schematic diagram of the structure of the cooperative sealing spring piece of the present invention; Figure 7 It is a structural schematic diagram of the lower sealing member of the present invention; Figure 8 It is a schematic structural diagram of the upper sealing member of the present invention; Fig. 9 for Figure 8 Bottom view of In the figure: Figure 2 (a) is a schematic diagram of the structure of the lower seal in an ideal state when the conventional valve is opened; Figure 2 (b) is a schematic diagram of the structure of the lower seal in a tilted state when the conventional valve is opened; 1. inlet block; 11. inlet port; 12. accommodating cavity; 121. upper step surface; 122. lower step surface; 2. Lower sealing member; 21. Inlet channel; 21a. First inlet channel; 21b. Second inlet channel; 22. Matching inclined surface; 23. First-stage column; 24. Second-stage column; 25. Third-stage column; 3. Upper sealing member; 31. Outflow channel; 32. Buffer groove; 33. Connecting groove; 34. Center channel; 4. horizontal guide spring; 41. annular portion; 42. raised portion; 5. Control lever; 6. Cooperative sealing spring; 61. Hollow structure; 62. Center hole; 7. Install the shrapnel; 8. Remove the shrapnel. DETAILED DESCRIPTION

[0021] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0022] like Figures 3 to 9 As shown, a valve for improving flow stability comprises: The inlet block 1 is provided with an inlet port 11 and a receiving cavity 12; The lower sealing member 2 is located in the accommodating cavity 12 and is provided with a plurality of inlet channels 21 communicating with the inlet port 11. The lower sealing member 2 is also provided with a matching inclined surface 22, which is inclined outward from bottom to top; The upper sealing member 3 is fixedly connected to the inlet block 1 and is provided with a plurality of outlet channels 31. The inlet of the outlet channel 31 is staggered with the outlet of the inlet channel 21. The horizontal guide spring piece 4 includes a circular ring portion 41 and at least three protrusions 42. The circular ring portion 41 is sleeved outside the lower seal 2 with a gap. All the protrusions 42 are evenly distributed along the circumference of the circular ring portion 41 and protrude inwardly from the inner circle of the circular ring portion 41 along the radial direction of the circular ring portion 41. All the protrusions 42 are in contact with the matching inclined surface 22 to apply a pre-tightening force to the lower seal 2. Under the action of the pre-tightening force, the lower seal 2 is in close contact with the upper seal 3 as a normal state. In this normal state, since the lower seal 2 is in close contact with the upper seal 3, the inlet channel 21 and the outlet channel 31 cannot be connected, and the valve is in a closed state. The control rod 5 acts on the lower sealing member 2 to push the lower sealing member 2 to move downward to overcome the pre-tightening force so as to form a gap between the lower sealing member 2 and the upper sealing member 3 .

[0023] The inventor of this patent discovered that the reason why the flow rate of the existing normally closed valve of the mass flow controller is unstable is that, since the end of the control rod 5 is generally a spherical surface or a flat surface, it is limited by the existence of processing errors. Even if it is a flat surface, some areas will be higher than other areas. When the control rod 5 is lowered to contact with the lower seal 2, the contact area between the two is very small, and due to the errors in assembly and processing, the contact point cannot be completely guaranteed to be on the axis of the lower seal 2. The position between the lower seal 2 and the spring structure is mainly fixed by the matching accuracy between the boss of the lower seal 2 and the center hole of the spring structure. In order to prevent locking, there must be a gap between the center hole of the spring structure and the boss of the lower seal 2, and the two are mainly fitted with two surfaces, so the lower seal 2 will tilt to one side along with the spring structure (i.e. Figure 2 As the elongation increases, the degree of inclination increases.

[0024] In order to solve the problem of unstable valve flow caused by the tilt of the lower seal 2 during the descent process, the inventor of this patent tried to fit the spring structure tightly with the lower seal 2. However, this would cause a dead zone in the entire structure, resulting in an abnormal uncontrollable flow.

[0025] The inventor of this patent has tried to increase the thickness and rigidity of the spring sheet structure, but due to the fact that the spring sheet structure is always in contact with the lower seal 2, although the tilt angle is reduced, a greater force is required to pre-deform the spring sheet structure after the rigidity is increased. In addition, a greater force needs to be applied to the control rod 5 to extend the control rod 5 downward, making it more difficult to extend the control rod 5, resulting in a narrower opening range, reducing the maximum output flow of the instrument, narrowing the scope of use of the instrument, and reducing the performance of the equipment.

[0026] The inventor of this patent has obtained the solution in this embodiment after many attempts. In the solution of this embodiment, the structure of the spring is improved. Figure 4 The horizontal guide spring piece 4 shown. Figure 3 , Figure 4 and Figure 5As shown, each protrusion 42 of the horizontal guide spring piece 4 can be deflected and deformed along the axial direction, and the horizontal guide spring piece 4 contacts the lower seal 2 only through its protrusion 42, and the corresponding contact point of the lower seal 2 is the matching bevel 22. Therefore, after actual assembly, the horizontal guide spring piece 4 and the matching bevel 22 of the lower seal 2 are in line contact or point contact, and three points determine a plane, and the design of at least three protrusions 42 can ensure that there are at least three point contacts between the two, and the overall contact is good. The horizontal guide spring piece 4 also has a certain pre-deformation, that is, the lower seal 2 is subjected to an upward force. Due to the existence of the matching bevel 22 of the lower seal 2, the forces at the three contact points can be decomposed into axial components and radial components. At least three radial components will cause the lower seal 2 to produce a slight displacement along the radial direction, and make the lower seal 2 better fit the upper seal 3, while the axial components will tightly attach the lower seal 2 to the upper seal 3. Moreover, as the control rod 5 extends downward to open the lower seal 2, the axial force generated by the horizontal guide spring sheet 4 will also increase, maintaining the position stability of the lower seal 2, and the circumferentially balanced radial force can also ensure that the lower seal 2 is parallel to the upper seal 3. Therefore, this embodiment effectively improves the flow stability of the valve without reducing the flow capacity of the structure, greatly optimizing the performance degradation caused by the defects of the traditional structure.

[0027] In one embodiment, Figure 3 and Figure 6 As shown, the valve for improving flow stability also includes a cooperative sealing spring piece 6, which is sleeved outside the lower seal 2 and is located below the horizontal guide spring piece 4. It acts on the lower seal 2 and is used to cooperate with the horizontal guide spring piece 4 to apply a pre-tightening force to the lower seal 2.

[0028] Specifically, considering that the larger and heavier the lower sealing member 2 is, the greater the pressing force required by the valve mechanism when sealing, a single spring sheet may not be sufficient to provide this supporting force. Therefore, a cooperative sealing spring sheet 6 is configured, so that the horizontal guide spring sheet 4 mainly provides the horizontal guide force, and the cooperative sealing spring sheet mainly provides the valve sealing force and the restoring force of the lower sealing member 2 after the control rod 5 moves upward.

[0029] In this embodiment, there are many ways to install and position the horizontal guide spring piece 4 and the cooperative sealing spring piece 6, and one of them is listed first.

[0030] like Figure 3 As shown, the peripheral wall of the accommodating cavity 12 is provided with an upper step surface 121 and a lower step surface 122; wherein, The lower end surface of the annular portion 41 is placed on the upper step surface 121, and the outer ring cooperates with the peripheral wall of the accommodating cavity 12 located above the upper step surface 121 to achieve positioning; The lower end surface of the cooperative sealing spring 6 is placed on the lower step surface 122, and the outer periphery cooperates with the peripheral wall of the accommodating cavity 12 located above the lower step surface 122 and / or the central hole 62 cooperates with the lower sealing member 2 to achieve positioning.

[0031] It should be noted that there are small clearances between the circumferential wall of the accommodating cavity 12 located above the upper step surface 121 and the outer ring of the annular portion 41, between the circumferential wall of the accommodating cavity 12 located above the lower step surface 122 and the outer ring of the cooperative sealing spring 6, and between the lower sealing component 2 and the center hole 62 of the cooperative sealing spring 6, which can both play a role in restraining and positioning and provide deformation space.

[0032] In one embodiment, Figure 3 , Figure 5 and Figure 7 As shown, the lower sealing member 2 comprises a first-stage column 23, a second-stage column 24 and a third-stage column 25 which are arranged in sequence from bottom to top and whose diameters increase step by step; wherein, A plurality of first inlet channels 21a are provided at the middle position of the lower sealing member 2 and penetrate the first-stage cylinder 23, the second-stage cylinder 24 and the third-stage cylinder 25 in the axial direction at the same time, and a plurality of second inlet channels 21b are provided at the edge position and penetrate only the third-stage cylinder 25 in the axial direction. Both the first inlet channels 21a and the second inlet channels 21b serve as the inlet channels 21; The cooperative sealing spring 6 is sleeved outside the first-stage column 23, with the upper end surface abutting against the lower surface of the second-stage column 24, and has a hollow structure 61 for fluid to flow through; The matching slope 22 is disposed on the third-level column 25 .

[0033] Specifically, a first inlet channel 21a and a second inlet channel 21b are provided. When the valve is in the open state, a part of the fluid flowing into the accommodating chamber 12 from the inlet port 11 flows directly into the gap between the upper seal 3 and the lower seal 2 through the first inlet channel 21a, and the other part flows into the gap between the upper seal 3 and the lower seal 2 through the hollow structure 61 of the cooperative sealing spring 6 and the second inlet channel 21b in sequence. This flow diversion method can disperse the impact force of the fluid on the lower seal 2 as much as possible, reduce the fluid pressure, and ensure the flow stability. In addition, the lower surface of the second-level column 24 is abutted against the cooperative sealing spring 6, and the matching slope 22 is set on the third-level column 25, which also well realizes the inlet function of the lower seal 2 and the cooperation with the horizontal guide spring 4 and the cooperative sealing spring 6, avoiding the influence and interference of the horizontal guide spring 4 and the cooperative sealing spring 6 on the inlet flow.

[0034] Moreover, in the present embodiment, the special position design of the first inlet channel 21a and the second inlet channel 21b enables the inlet channel 21 to effectively reduce the pressure of the fluid, so that the first inlet channel 21a and the second inlet channel 21b can be arranged to be parallel to the axial direction of the lower seal 2, thereby reducing the processing difficulty of the inlet channel 21.

[0035] In one embodiment, Figure 3 and Figure 7 As shown, the matching inclined surface 22 surrounds the outer periphery of the second inlet channel 21b.

[0036] Specifically, considering that the positions of the line contact or point contact between the raised portion 42 of the horizontal guide spring piece 4 and the mating slope 22 and the radial overlap area with the mating slope 22 are different at different valve openings, setting the second inlet channel 21b at a position closer to the inside than the mating slope 22 can effectively avoid flow fluctuations caused by different blocking areas of the second inlet channel 21b at different valve openings.

[0037] In one embodiment, Figure 7 As shown, all the first inlet channels 21a and all the second inlet channels 21b are arranged in a circle and are evenly arranged. In this way, the stability of the valve flow can be further ensured; and it is also convenient for the inlet of the outflow channel 31 on the upper sealing member 3 to stagger the outlet of the inflow channel 21.

[0038] In one embodiment, Figure 3 , Figure 8 and Fig. 9 As shown, the upper sealing member 3 is provided with buffer grooves 32 at the position of the circle arranged opposite to the first inlet channel 21a and at the position of the circle discharged opposite to the second inlet channel 21b.

[0039] In this way, the fluid pressure can be further reduced to ensure smooth outflow of the fluid, thereby ensuring the stability of the flow rate.

[0040] In one embodiment, Figure 3 , Figure 8 and Fig. 9 As shown, a plurality of outflow channels 31 are arranged along the circumferential direction of the upper seal 3 and extend along the radial direction of the upper seal 3 .

[0041] A communication groove 33 is provided at a position of the upper sealing member 3 that is offset from the inlet channel 21 . The communication groove 33 extends from the lower end surface of the upper sealing member 3 to the corresponding outlet channel 31 .

[0042] Specifically, the fluid entering the connecting groove 33 overflows into the outflow channel 31 , which can further reduce the fluid pressure, further ensure the smooth outflow of the fluid, and thus further ensure the stability of the flow rate.

[0043] The connecting groove 33 and the buffer groove 32 are both annular in shape and are arranged at intervals along the radial direction of the upper sealing member 3 .

[0044] In one embodiment, Figure 3 , Figure 8 and Fig. 9 As shown, the upper seal 3 is provided with a central channel 34 for the control rod 5 to pass through, and all the inlet channels 21 are staggered from the central channel 34. In this way, it is convenient for the control rod 5 to act on the lower seal 2, and the control rod 5 can be prevented from blocking the inlet channel 21.

[0045] The valve for improving flow stability involved in the above embodiment is Figure 3 The working process of the valve shown is: The horizontal guide spring piece 4 and the cooperative sealing spring piece 6 apply a pre-tightening force to the lower sealing member 2, so that the upper surface of the lower sealing member 2 is in close contact with the lower surface of the upper sealing member 3 as a normal state, that is, the valve is a normally closed valve.

[0046] In the process that the control rod 5 extends downward to open the lower seal 2 by overcoming the axial elastic force applied by the horizontal guide spring piece 4 and the cooperative sealing spring piece 6, the larger axial elastic force jointly provided by the horizontal guide spring piece 4 and the cooperative sealing spring piece 6 maintains the position stability of the lower seal 2, and the circumferentially balanced radial component force provided by the horizontal guide spring piece 4 can also ensure that the lower seal 2 is parallel to the upper seal 3. On the whole, the horizontal guide spring piece 4 mainly provides horizontal guiding force, and the cooperative sealing spring piece mainly provides valve sealing force and the restoring force of the lower seal 2 after the control rod 5 moves upward.

[0047] When the valve is in the open state, part of the fluid flowing into the accommodating chamber 12 from the inlet 11 directly flows into the corresponding buffer groove 32 through the first inlet channel 21a, and the other part flows into the corresponding buffer groove 32 through the hollow structure 61 of the cooperative sealing spring 6 and the second inlet channel 21b in sequence. This diversion method can disperse the impact force of the fluid on the lower seal 2 as much as possible, reduce the fluid pressure, ensure the stability of the fluid, and thus ensure the stability of the flow. In addition, the second inlet channel 21b is located in the space surrounded by the inner circle of the matching inclined surface 22, which can ensure that the total area of ​​all inlet channels 21 is consistent when the valve has different openings, and effectively avoid the flow fluctuation caused by different inlet areas due to different openings of the valve. The fluid flowing into the buffer groove 32 is uniformly depressurized in the buffer groove 32 and then smoothly flows into the connecting groove 33 from the gap between the upper seal 3 and the lower seal 2, and then overflows to the multiple outflow channels 31 uniformly distributed along the circumference and extending radially after the connecting groove 33 is uniformly depressurized again, and finally flows out from the outflow channel 31. The design of the buffer groove 32 and the connecting groove 33 further ensures that the fluid flows out smoothly, thereby further ensuring the stability of the flow rate.

[0048] A mass flow controller comprises the valve for improving flow stability in any of the above embodiments.

[0049] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A valve for improving flow stability, characterized in that: include: An inlet block (1) is provided with an inlet port (11) and a receiving cavity (12); A lower sealing member (2) is located in the accommodating cavity (12), and is provided with a plurality of inlet channels (21) communicating with the inlet port (11), and is also provided with a matching inclined surface (22), wherein the matching inclined surface (22) is inclined outward from bottom to top; The upper sealing member (3) is fixedly connected to the inlet block (1) and is provided with a plurality of outlet channels (31), wherein the inlet of the outlet channel (31) is staggered with the outlet of the inlet channel (21). A horizontal guide spring (4), comprising a circular portion (41) and at least three protrusions (42), wherein the circular portion (41) is sleeved outside the lower seal (2) with a gap therebetween, all the protrusions (42) are evenly distributed along the circumference of the circular portion (41) and protrude inwardly from the circular portion (41) along the radial direction of the circular portion (41), all the protrusions (42) are in contact with the matching inclined surface (22) to apply a pre-tightening force to the lower seal (2), and the lower seal (2) is normally in close contact with the upper seal (3) under the action of the pre-tightening force; A control rod (5) acts on the lower sealing member (2) and is used to push the lower sealing member (2) to overcome the pre-tightening force and move downward to form a gap between the lower sealing member (2) and the upper sealing member (3).

2. The valve for improving flow stability according to claim 1, characterized in that: It also includes a cooperative sealing spring (6), which is sleeved outside the lower sealing member (2) and is located below the horizontal guide spring (4), acting on the lower sealing member (2) to cooperate with the horizontal guide spring (4) to apply a pre-tightening force to the lower sealing member (2).

3. The valve for improving flow stability according to claim 2, characterized in that: The peripheral wall of the accommodating cavity (12) is provided with an upper step surface (121) and a lower step surface (122); wherein: The lower end surface of the annular portion (41) is placed on the upper step surface (121), and the outer ring cooperates with the peripheral wall of the accommodating cavity (12) located above the upper step surface (121) to achieve positioning; The lower end surface of the cooperative sealing spring (6) is placed on the lower step surface (122), and the outer periphery cooperates with the peripheral wall of the accommodating cavity (12) located above the lower step surface (122) and / or the central hole (62) cooperates with the lower sealing component (2) to achieve positioning.

4. The valve for improving flow stability according to claim 2, characterized in that: The lower sealing member (2) comprises a first-stage column (23), a second-stage column (24) and a third-stage column (25) which are arranged in sequence from bottom to top and whose diameters increase step by step; wherein: A plurality of first inlet channels (21a) are arranged at the middle position of the lower sealing member (2) and penetrate the first-stage column (23), the second-stage column (24) and the third-stage column (25) in the axial direction at the same time, and a plurality of second inlet channels (21b) are arranged at the edge position and penetrate only the third-stage column (25) in the axial direction, wherein the first inlet channels (21a) and the second inlet channels (21b) both serve as the inlet channels (21); The cooperative sealing spring (6) is sleeved outside the first-stage column (23), the upper end surface of which abuts against the lower surface of the second-stage column (24), and has a hollow structure (61) for fluid to flow through; The matching inclined surface (22) is arranged on the third-level column (25).

5. The valve for improving flow stability according to claim 4, characterized in that: The matching inclined surface (22) surrounds the outer periphery of the second inlet channel (21b).

6. The valve for improving flow stability according to claim 4, characterized in that: All the first inlet channels (21a) and all the second inlet channels (21b) are arranged in a circle.

7. The valve for improving flow stability according to claim 6, characterized in that: The upper sealing member (3) is provided with buffer grooves (32) at the position of the circle formed by the first inlet channel (21a) and at the position of the circle discharged by the second inlet channel (21b).

8. The valve for improving flow stability according to claim 1, characterized in that: A plurality of outflow channels (31) are arranged along the circumference of the upper sealing member (3) and extend along the radial direction of the upper sealing member (3); A communication groove (33) is provided on the upper sealing member (3) at a position offset from the inlet channel (21), and the communication groove (33) extends from the lower end surface of the upper sealing member (3) to the corresponding outlet channel (31).

9. The valve for improving flow stability according to claim 1, characterized in that: The upper sealing member (3) is provided with a central passage (34) for the control rod (5) to pass through, and all the inlet passages (21) are staggered from the central passage (34).

10. A mass flow controller, characterized in that: A valve for improving flow stability comprising the valve according to any one of claims 1 to 9.

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