Valve for improving flow stability and mass flow controller using the same

Abstract

The present invention relates to the field of valves, and particularly to a valve for improving flow stability and a mass flow controller applying the same. The valve includes an inlet block, a lower seal, an upper seal, a horizontal guiding spring piece, and a control rod. The inlet block is provided with an inlet port and a receiving cavity; the lower seal is located in the receiving cavity and is provided with a plurality of inlet channels. The lower seal is further provided with a mating inclined surface which is inclined outward from bottom to top; the upper seal is fixedly connected to the inlet block and is provided with a plurality of outlet channels, and the outlet channels are staggered with the inlet channels. The horizontal guiding spring piece includes an annular portion and at least three protruding portions. The annular portion is sleeved outside the lower seal with a gap therebetween, and all the protruding portions are evenly distributed along the circumference of the annular portion and protrude inward in the radial direction from the annular portion. All the protruding portions are in contact with the mating inclined surface to apply a pre-tightening force to the lower seal. The present invention can ensure that the lower seal and the upper seal remain horizontal during and after the opening process of the valve, thereby ensuring stable flow rate.

Description

Technical Field

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

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

[0003] The existing normally closed valve of the mass flow controller (specifically as shown in Figure 1 ) includes an inlet block 1, a lower seal 2, an upper seal 3, a shrapnel structure, and a control rod 5. The inlet block 1 is provided with an inlet port 11 and a receiving cavity 12; the lower seal 2 is located in the receiving cavity 12 and is provided with a plurality of inlet channels 21 communicating with 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 offset from the outlet of the inlet channel 21. The shrapnel structure is sleeved on the lower seal 2 and applies a pre-tightening force to the lower seal 2, making it normal for the lower seal 2 to closely adhere to the upper seal 3. Since the inlet of the outlet channel 31 of the upper seal 3 is offset from the outlet of the inlet channel 21 of the lower seal 2, the gas will be blocked by the upper seal 3 after flowing into the inlet block 1. That is, the valve is normally closed. The shrapnel structure is a thin sheet with a hollow hole processed in the middle, which can be a single shrapnel or a double shrapnel. Figure 1 As shown, the double shrapnel is respectively the upper shrapnel 7 and the lower shrapnel 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, creating a gap between the upper seal 3 and the lower seal 2 for gas to flow through. The ideal gap state is that the heights of all positions of the gap are equal, as shown in (a) of Figure 2 , that is, the gap generated when the lower seal 2 is always horizontal with the upper seal 3 during the descending process. However, in actual use, the lower seal 2 will tilt during the process of being pushed down by the control rod 5, as shown in (b) of Figure 2 .

[0005] When the valve opening is gradually increased and the tilt angle becomes larger and larger, it becomes more difficult to maintain the position of the valve. Because the gas will continuously flow through the opening gap, the force exerted on the lower seal 2 by the gas will also 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, resulting in unstable valve flow rate, 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 that improves flow stability. It can ensure that the lower seal and the upper seal remain horizontal during and after the opening process of the valve, thereby ensuring stable flow.

[0008] To solve the above technical problems, the technical solution of the present invention is: A valve for improving flow stability, comprising:

[0009] An inlet flow block provided with an inlet flow port and a receiving cavity;

[0010] A lower seal located in the receiving cavity, provided with a plurality of inlet flow channels communicating with the inlet flow port. The lower seal is further provided with a mating inclined surface that slopes outward from bottom to top.

[0011] An upper seal fixedly connected to the inlet flow block, provided with a plurality of outlet flow channels. The inlet of the outlet flow channel is offset from the outlet of the inlet flow channel.

[0012] A horizontal guiding elastic sheet, including a circular ring portion and at least three protruding portions. The circular ring portion is sleeved outside the lower seal with a gap. All the protruding portions are evenly distributed along the circumference of the circular ring portion and protrude inward from the circular ring portion in the radial direction of the circular ring portion. All the protruding portions are in contact with the mating inclined surface to apply a pre-tightening force to the lower seal. The lower seal is in a normal state of closely adhering to the upper seal under the action of the pre-tightening force.

[0013] A control rod acts on the lower seal and is used to push the lower seal to move downward against the pre-tightening force to form a gap between the lower seal and the upper seal.

[0014] Furthermore, in order to improve the elastic supporting force of the valve on the upper seal and improve the flow stability, the valve for improving flow stability further includes a cooperative sealing elastic sheet. The cooperative sealing elastic sheet is sleeved outside the lower seal, located below the horizontal guiding elastic sheet, and acts on the lower seal to cooperate with the horizontal guiding elastic sheet to apply a pre-tightening force to the lower seal.

[0015] Furthermore, in order to facilitate the installation and positioning of the horizontal guiding elastic sheet and the cooperative sealing elastic sheet, the peripheral wall of the receiving cavity is provided with an upper step surface and a lower step surface; wherein,

[0016] The lower end surface of the circular ring portion is placed on the upper step surface, and the outer circle cooperates with the peripheral wall of the receiving cavity above the upper step surface to achieve positioning;

[0017] 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.

[0018] 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,

[0019] 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;

[0020] 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;

[0021] The matching inclined surface is arranged on the third-level column.

[0022] Furthermore, the matching inclined surface surrounds the outer circumference of the second inlet channel.

[0023] Furthermore, all the first inlet channels and all the second inlet channels are arranged in a circle.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The invention also relates to a mass flow controller comprising a valve for improving flow stability.

[0029] After adopting the above technical solution, the present invention uses a horizontal guiding elastic sheet. Each convex part of the horizontal guiding elastic sheet can be deflected along the axial direction. The horizontal guiding elastic sheet only contacts the lower seal through its convex parts, and the corresponding contact part of the lower seal is a matching inclined surface. Therefore, after actual assembly, the contact between the horizontal guiding elastic sheet and the matching inclined surface of the lower seal is line contact or point contact. Three points determine a plane, and the design of at least three convex parts can ensure that there are at least three point contacts between the two, and the overall contact is good. The horizontal guiding elastic sheet also has a certain pre-deformation, that is, the lower seal bears an upward force. Due to the existence of the matching inclined surface of the lower seal, the forces at the three contact points can all be decomposed into a component force along the axial direction and a component force along the radial direction. At least three radial component forces will cause the lower seal to have a small displacement along the radial direction and make the lower seal better fit the upper seal on the surface, while the axial component forces will tightly attach the lower seal to the upper seal. Moreover, after the lower seal is opened as the control rod extends downward, the axial component force generated by the horizontal guiding elastic sheet will also increase accordingly, maintaining the position stability of the lower seal, and the circumferentially balanced radial component forces 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-through capacity of the structure, and greatly optimizes the performance degradation caused by the defects of the traditional structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of a traditional valve;

[0031] Figure 2 is Figure 1 a schematic structural diagram of the lower seal in the ideal state and the inclined state when the valve in

[0032] Figure 3 a schematic structural diagram of the valve of the present invention for improving flow stability;

[0033] Figure 4 is a schematic structural diagram of the horizontal guiding elastic sheet of the present invention;

[0034] Figure 5 is a schematic structural diagram of the contact between the horizontal guiding elastic sheet of the present invention and the matching inclined surface of the lower seal;

[0035] Figure 6 is a schematic structural diagram of the cooperative sealing elastic sheet of the present invention;

[0036] Figure 7 is a schematic structural diagram of the lower seal of the present invention;

[0037] Figure 8 is a schematic structural diagram of the upper seal of the present invention;

[0038] Figure 9 isFigure 8 Bottom view;

[0039] In the figure:

[0040] Figure 2 In (a), it is a schematic structural diagram of the lower seal in an ideal state when a traditional valve is opened;

[0041] Figure 2 In (b), it is a schematic structural diagram of the lower seal in an inclined state when a traditional valve is opened;

[0042] 1. Inlet flow block; 11. Inlet flow port; 12. Accommodating cavity; 121. Upper step surface; 122. Lower step surface;

[0043] 2. Lower seal; 21. Inlet flow channel; 21a. First inlet flow channel; 21b. Second inlet flow channel; 22. Matching inclined surface; 23. First-stage cylinder; 24. Second-stage cylinder; 25. Third-stage cylinder;

[0044] 3. Upper seal; 31. Outlet flow channel; 32. Buffer groove; 33. Connecting groove; 34. Central channel;

[0045] 4. Horizontal guiding elastic piece; 41. Ring part; 42. Protruding part;

[0046] 5. Control rod;

[0047] 6. Cooperative sealing elastic piece; 61. Hollow structure; 62. Central hole;

[0048] 7. Upper elastic piece;

[0049] 8. Lower elastic piece. Detailed implementation manners

[0050] In order to make the content of the present invention be more clearly understood, the following further describes the present invention in detail according to specific embodiments and in conjunction with the accompanying drawings.

[0051] As Figures 3 to 9 shown, a valve for improving flow stability includes:

[0052] An inlet flow block 1, provided with an inlet flow port 11 and an accommodating cavity 12;

[0053] A lower seal 2, located in the accommodating cavity 12, provided with a plurality of inlet flow channels 21 communicating with the inlet flow port 11, and the lower seal 2 is further provided with a matching inclined surface 22, and the matching inclined surface 22 is inclined outward from bottom to top;

[0054] An upper seal 3, fixedly connected to the inlet flow block 1, provided with a plurality of outlet flow channels 31, and the inlets of the outlet flow channels 31 are staggered from the outlets of the inlet flow channels 21,

[0055] The horizontal guiding elastic piece 4 includes an annular part 41 and at least three protruding parts 42. The annular part 41 is sleeved outside the lower seal 2 with a gap therebetween. All the protruding parts 42 are evenly distributed along the circumferential direction of the annular part 41 and protrude inward along the radial direction of the annular part 41 from the inner circle of the annular part 41. All the protruding parts 42 are in contact with the mating 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 a normal state of closely adhering to the upper seal 3. In this normal state, since the lower seal 2 closely adheres to the upper seal 3, the inflow channel 21 and the outflow channel 31 cannot communicate, and the valve is in a closed state;

[0056] The control rod 5 acts on the lower seal 2 and is used to push the lower seal 2 to move downward against the pre-tightening force to form a gap with the upper seal 3.

[0057] The inventor of this patent found that the reason for the unstable flow of the existing normally closed valve of the mass flow controller is that since the end of the control rod 5 is generally spherical or flat, due to the existence of machining errors, even if it is a flat surface, there will be some areas higher than other areas. When the control rod 5 descends to contact the lower seal 2, the contact area between the two is very small, and due to the existence of assembly and machining errors, the contact point cannot completely ensure being on the axis of the lower seal 2. Between the lower seal 2 and the elastic piece structure, the position is mainly fixed by the matching accuracy between the boss of the lower seal 2 and the central hole of the elastic piece structure. In order to prevent jamming, there must be a gap between the central hole of the elastic piece structure and the boss of the lower seal 2, and mainly two surfaces are in contact between the two, so the situation that the lower seal 2 tilts to one side together with the elastic piece structure will occur (i.e., Figure 2 the situation shown in (b) of

[0058] 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 tightly fit between the elastic piece structure and the lower seal 2. However, it will cause a dead zone in the whole structure and an abnormal situation where the flow rate is uncontrollable.

[0059] The inventor of this patent also tried to increase the thickness and stiffness of the elastic piece structure. However, limited by the fact that the elastic piece structure is always in surface contact with the lower seal 2, although the tilt angle will be reduced, after the stiffness increases, a greater force is required to pre-deform the elastic piece structure. And it will also cause a greater force to be applied to the control rod 5 to make the control rod 5 extend downward, making it more difficult for the control rod 5 to extend, resulting in a narrower opening range, reducing the maximum output flow rate of the instrument, narrowing the use range of the instrument, and reducing the equipment performance.

[0060] After many attempts, the inventor of this patent obtained the solution in this embodiment. In the solution of this embodiment, the structure of the elastic piece is improved, and the Figure 4 shown horizontal guiding elastic piece 4 is adopted. AsFigure 3 , Figure 4 and Figure 5 As shown, each convex portion 42 of the horizontal guiding spring piece 4 can be deflected and deformed along the axial direction. The horizontal guiding spring piece 4 only contacts the lower seal 2 through its convex portion 42, and the corresponding contact portion of the lower seal 2 is the mating inclined surface 22. Therefore, after actual assembly, the contact between the horizontal guiding spring piece 4 and the mating inclined surface 22 of the lower seal 2 is line contact or point contact. Three points determine a plane, and the design of at least three convex portions 42 can ensure that there are at least three point contacts between the two, and the overall contact is good. The horizontal guiding spring piece 4 also has a certain pre-deformation, that is, the lower seal 2 bears an upward force. Due to the existence of the mating inclined surface 22 of the lower seal 2, the forces at the three contact points can all be decomposed into a component force along the axial direction and a component force along the radial direction. At least three radial component forces will cause the lower seal 2 to generate a small displacement along the radial direction and make the lower seal 2 better fit the upper seal 3 on the surface, while the axial component force will press the lower seal 2 tightly against the upper seal 3. Moreover, after the control rod 5 extends downward to open the lower seal 2, the axial component force generated by the horizontal guiding spring piece 4 will also increase accordingly, maintaining the position stability of the lower seal 2, and the circumferentially balanced radial component forces 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-through capacity of the structure, and greatly optimizes the performance degradation caused by the defects of the traditional structure.

[0061] In one embodiment, as Figure 3 and Figure 6 shown, the valve for improving the flow stability further includes a cooperative sealing spring piece 6. The cooperative sealing spring piece 6 is sleeved outside the lower seal 2, located below the horizontal guiding spring piece 4, and acts on the lower seal 2 to cooperate with the horizontal guiding spring piece 4 to apply a pre-tightening force to the lower seal 2.

[0062] Specifically, considering that the larger and heavier the lower seal 2 is, the greater the pressing force required for the valve mechanism during sealing, and a single spring piece may not be sufficient to provide this supporting force. Therefore, a cooperative sealing spring piece 6 is further configured. In this way, the horizontal guiding spring piece 4 mainly provides the horizontal guiding force, and the cooperative sealing spring piece mainly provides the valve sealing force and the restoring force of the lower seal 2 after the control rod 5 moves upward.

[0063] In this embodiment, there are various installation and positioning methods for the horizontal guiding spring piece 4 and the cooperative sealing spring piece 6. One of them is listed first.

[0064] As Figure 3 shown, the peripheral wall of the accommodating cavity 12 is provided with an upper step surface 121 and a lower step surface 122; among them,

[0065] The lower end surface of the circular ring part 41 is placed on the upper step surface 121, and the outer ring is fitted with the peripheral wall of the accommodating cavity 12 above the upper step surface 121 to achieve positioning;

[0066] The lower end surface of the cooperative sealing elastic sheet 6 is placed on the lower step surface 122, and the outer periphery is fitted with the peripheral wall of the accommodating cavity 12 above the lower step surface 122 and / or the central hole 62 is fitted with the lower seal 2 to achieve positioning.

[0067] It should be noted that between the peripheral wall of the accommodating cavity 12 above the upper step surface 121 and the outer ring of the circular ring part 41, between the peripheral wall of the accommodating cavity 12 above the lower step surface 122 and the outer ring of the cooperative sealing elastic sheet 6, and between the lower seal 2 and the central hole 62 of the cooperative sealing elastic sheet 6, all are small clearance fits, that is, they can not only play a role in restricting positioning but also give a deformation space.

[0068] In one embodiment, as Figure 3 、 Figure 5 and Figure 7 shown, the lower seal 2 has a first-stage cylinder 23, a second-stage cylinder 24, and a third-stage cylinder 25 that are arranged in sequence from bottom to top and have gradually increasing diameters; among them,

[0069] A plurality of first inflow channels 21a that axially penetrate the first-stage cylinder 23, the second-stage cylinder 24, and the third-stage cylinder 25 at the same time are provided at the middle position of the lower seal 2, and a plurality of second inflow channels 21b that axially penetrate only the third-stage cylinder 25 are provided at the edge position. The first inflow channels 21a and the second inflow channels 21b both serve as the inflow channel 21;

[0070] The cooperative sealing elastic sheet 6 is sleeved outside the first-stage cylinder 23, and the upper end surface abuts against the lower surface of the second-stage cylinder 24, and has a hollow structure 61 for fluid to flow through;

[0071] The mating inclined surface 22 is provided on the third-stage cylinder 25.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] In one embodiment, Figure 3 , Figure 8 and Figure 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.

[0078] 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.

[0079] In one embodiment, Figure 3 , Figure 8 and Figure 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 .

[0080] 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 .

[0081] 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.

[0082] 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 .

[0083] In one embodiment, Figure 3 , Figure 8 and Figure 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.

[0084] The valve for improving flow stability involved in the above embodiment is Figure 3 The working process of the valve shown is:

[0085] 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.

[0086] 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.

[0087] When the valve is in the open state, for the fluid flowing into the accommodating cavity 12 from the inlet 11, a part of it directly flows into the corresponding buffer tank 32 through the first inlet channel 21a, and another part flows into the corresponding buffer tank 32 through the hollow structure 61 of the cooperative sealing elastic sheet 6 and the second inlet channel 21b in sequence. This way of flow splitting can disperse the impact force of the fluid on the lower seal 2 as much as possible, reduce the fluid pressure, ensure the fluid is stable, and thus ensure the flow rate is stable. Moreover, the second inlet channel 21b is located in the space surrounded by the inner circle of the mating inclined surface 22, which can ensure that the total area of all the inlet channels 21 is the same at different opening degrees of the valve, effectively avoiding flow rate fluctuations caused by different inlet areas due to different opening degrees of the valve. The fluid flowing into the buffer tank 32 flows smoothly into the communication tank 33 through the gap between the upper seal 3 and the lower seal 2 after uniform flow and pressure reduction in the buffer tank 32, and overflows to a plurality of outlet channels 31 that are circumferentially evenly distributed and radially extended after uniform flow and pressure reduction again in the communication tank 33, and finally flows out from the outlet channels 31. The design of the buffer tank 32 and the communication tank 33 further ensures the stable outflow of the fluid, and thus further ensures the stability of the flow rate.

[0088] A mass flow controller includes a valve for improving flow rate stability in any of the above embodiments.

[0089] Enlightened by the above ideal embodiments according to the present invention, through the above description, relevant staff can completely make various changes and modifications within the scope not deviating from the technical idea of this invention. The technical scope of this invention is not limited to the content in 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 piece (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), each protrusion (42) of the horizontal guide spring piece (4) can be deflected and deformed along the axial direction, 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), with its upper end surface abutting against the lower surface of the second-stage column (24), and having 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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