A high-frequency fast-response one-way valve for a micropump

Abstract

The utility model relates to the technical fields of check valve especially, it relates to a high frequency quick response's check valve for micropump, including first board, valve and second board that stack in proper order, first board surface is equipped with a plurality of even interval arrangement's first through -hole, second board surface is equipped with the open area that covers first through -hole arrangement area, valve sets up between first board with second board, and surface is equipped with a plurality of interval arrangement's second through -hole, second through -hole with first through -hole is misaligned distribution and exposes in open area in plane, through above -mentioned design, when fluid reverse flow, fluid can directly impact in valve surface by open area and drive valve to close first through -hole to realize reverse cut -off, can effectively reduce fluid permeation to narrow gap's delay, thereby reduced the closing response time of valve, and still can reduce the pressure loss of fluid permeation between second board and valve, thereby effectively promoted the high frequency response performance of valve.

Description

Technical Field

[0001] This utility model relates to the technical field of check valves, and in particular to a high-frequency, fast-response check valve for micro-pumps. Background Technology

[0002] Piezoelectric micropumps, as key components of microfluidic systems, are widely used in consumer electronics, biomedicine, and other fields. One-way valves, as an important part of piezoelectric micropumps, directly affect the operating efficiency and stability of the pump. Typically, traditional piezoelectric micropump one-way valves operate at low frequencies below 20kHz, making them unsuitable for high-frequency opening and closing with piezoelectric micropumps, resulting in insufficient output capacity.

[0003] Currently, existing technology provides a one-way valve with high-frequency response. By setting substantially offset orifices on the first and second plates, the valve disc can move between the two plates in response to changes in the direction of fluid pressure difference, achieving rapid opening and closing of the valve. However, after opening, the valve disc will microscopically adhere to the surface of the second plate under the action of van der Waals forces and fluid tension. This means that when the pressure difference direction reverses, the fluid cannot quickly penetrate into the narrow gap between the disc and the second plate, resulting in excessive flow resistance, reduced closing efficiency, and consequently, decreased valve response efficiency.

[0004] Therefore, there is an urgent need to design a new type of check valve to reduce flow resistance and valve closing time, and improve valve response efficiency. Utility Model Content

[0005] To address the problems mentioned above, this invention provides a high-frequency, fast-response check valve for micro-pumps, which reduces the valve's closing response time and thus effectively improves the valve's high-frequency response performance.

[0006] The solution adopted by this utility model to solve its technical problem is: a one-way valve for a high-frequency fast-response micropump, comprising a first plate, a valve and a second plate stacked in sequence. The surface of the first plate is provided with a plurality of uniformly arranged first through holes. The surface of the valve is provided with a plurality of uniformly arranged second through holes at positions corresponding to the arrangement area of ​​the first through holes. The first through holes and the second through holes are staggered in the plane. An open area is formed through the surface of the second plate, and the open area covers the arrangement area of ​​the first through holes and the second through holes.

[0007] Furthermore, a space is formed between the first plate and the second plate, and the valve is movably disposed in the space and can be switched to adhere to the surface of the first plate or the surface of the second plate in response to fluid pressure difference.

[0008] Furthermore, the second plate is thinned at the surface of the valve and at the location corresponding to the open area to form the spacer.

[0009] Furthermore, a partition or protective film is provided between the second plate and the first plate to separate the space forming the interval, and the partition or protective film is exposed in the open area.

[0010] Furthermore, a plurality of the first through holes and a plurality of the second through holes are respectively gathered on the surface of the first plate and the surface of the valve to form a hole array. The hole array has multiple holes and is evenly spaced. The number of open areas is the same as the number of holes in the hole array and corresponds one-to-one.

[0011] Furthermore, a limiting region for restricting valve movement is formed between adjacent open regions, and the limiting region corresponds to the spacing between two adjacent aperture arrays.

[0012] Furthermore, the first through hole is a straight through hole or a tapered hole, and the diameter of the air inlet end of the tapered hole is larger than the diameter of the end facing the valve.

[0013] Furthermore, the edges of the first plate and the second plate are fixed together by laser welding.

[0014] In summary, the beneficial effects of this utility model are as follows: By setting equidistant first through holes and second through holes on the surface of the first plate and the surface of the valve respectively, and setting an open area on the second plate at the position corresponding to the arrangement area of ​​the first and second through holes, when the fluid flows in reverse, the fluid can directly impact the valve surface through the open area, driving the valve to close the first through holes to achieve reverse cutoff. This can effectively reduce the delay of fluid penetration into the narrow gap, thereby reducing the valve's closing response time. It can also reduce the pressure loss of fluid penetration between the second plate and the valve, thereby effectively improving the high-frequency response performance of the valve.

[0015] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this embodiment;

[0017] Figure 2 This is a cross-sectional view of the valve in this embodiment when it is closed;

[0018] Figure 3 This is a cross-sectional view of the valve when it is open in this embodiment;

[0019] Figure 4 This is a structural diagram showing the configuration of a partition or protective film in this embodiment.

[0020] In the diagram: 1. First plate; 11. First through hole; 2. Second plate; 21. Open area; 22. Restricted area; 3. Valve; 31. Second through hole; 4. Spacing; 5. Septum. Detailed Implementation

[0021] To make the content of this utility model easier to understand, the present utility model will be further described below with reference to specific embodiments and accompanying drawings.

[0022] It should be noted that the terms "center," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer" used herein to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise stated, "a plurality of" means two or more.

[0023] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] like Figures 1 to 4 As shown, this embodiment provides a high-frequency, fast-response check valve for micropumps, which can reduce the valve's closing response time, thereby achieving efficient flow and cut-off of fluid under high-frequency operating conditions and exhibiting excellent high-frequency response performance. The check valve of this embodiment includes a first plate 1, a valve 3, and a second plate 2 stacked sequentially along the axial direction. The edges of the first plate 1 and the second plate 2 are laser-welded to form a closed cavity. The valve 3 is clamped between the first plate 1 and the second plate 2 and can move axially within the closed cavity, thereby cooperating with the first plate 1 and the second plate 2 to complete the unidirectional control of the fluid.

[0025] like Figure 1 and Figure 4As shown, in this embodiment, the surface of the first plate 1 is vertically provided with a plurality of uniformly spaced first through holes 11, and the surface of the valve 3 is vertically provided with a plurality of spaced second through holes 31 at positions corresponding to the arrangement of the first through holes 11. The second through holes 31 and the first through holes 11 are staggered in the plane, that is, there is no overlapping area between them in the projection direction. When the valve 3 is attached to the surface of the first plate 1, the gap between each second through hole 31 will cover the surface of the first through hole 11, thereby blocking the fluid and achieving reverse cutoff. When the valve 3 is away from the first plate 1, the gap formed between them allows the fluid to flow from the first through hole 11 to the second through hole 31, thereby achieving forward conduction.

[0026] In this embodiment, the second plate 2 is located on the side of the valve 3 away from the first plate 1, and an open area 21 is provided on the surface of the second plate 2 at the position corresponding to the arrangement area of ​​the first through hole 11 and the second through hole 31. In this embodiment, the open area 21 is an unobstructed opening area, and the opening completely covers the arrangement range of the first through hole 11 and the second through hole 31. When the fluid flows in the forward direction, the fluid can pass through the second through hole 31 and flow out directly through the open area 21. When the fluid flows in the reverse direction, the reverse fluid can directly act on the surface of the valve 3 through the open area 21, pushing the valve 3 to move to fit against the surface of the first plate 1 to block the fluid. It does not need to penetrate into the narrow gap between the valve 3 and the second plate 2 to push it, which greatly shortens the pressure transmission path and reduces the pressure loss caused by the fluid penetrating between the second plate 2 and the valve 3. This allows the valve 3 to quickly fit against the first plate 1 and block the first through hole 11, thereby effectively improving the high-frequency response performance of the valve.

[0027] like Figure 1 and Figure 4 As shown, in this embodiment, multiple first through holes 11 are evenly arranged along the plane of the first plate 1 to form several independent hole arrays. At the same time, the second through holes 31 are also evenly arranged along the plane of the second plate 2 to form several independent hole arrays. The hole arrays on the first plate 1 and the hole arrays on the second plate 2 correspond in position, so that after the fluid passes through the hole array on the first plate 1, it can be quickly output through the hole array on the second plate 2 without the need for additional fluid permeation. This reduces the response time of the one-way valve opening and further improves the high-frequency response performance of the one-way valve.

[0028] Furthermore, in this embodiment, multiple open areas 21 are provided corresponding to each hole array, allowing fluid flowing forward through each hole array to directly flow out through the corresponding open area 21, thereby improving the opening speed. In addition, when the fluid flows in the reverse direction, each open area can simultaneously act on the surface of the valve 3, thereby achieving rapid movement of the valve 3 and improving the response time of the one-way valve. Moreover, the valve 3 can move simultaneously towards the first plate 1, achieving uniform movement of the valve 3, thereby improving the shut-off effect of the one-way valve and achieving instantaneous shut-off.

[0029] Furthermore, a restriction zone 22 is formed between adjacent open areas 21 in this embodiment. The restriction zone 22 can limit the maximum movement distance of the valve 3, preventing the valve 3 from failing due to excessive deformation during high-frequency vibration. Additionally, the restriction zone 22 can be combined with the open area 21 to prevent the valve 3 from frequently colliding with the first plate 1 or the second plate 2 during repeated opening and closing of the one-way valve, thereby effectively improving the service life of the valve 3 and thus extending the service life of the one-way valve. In this embodiment, the restriction zone 22 corresponds to the spacing between adjacent orifice arrays, allowing the restriction zone 22 to restrict the valve 3 in the blank space where the second through hole 31 is not provided. This prevents valve 3 deformation while ensuring rapid fluid flow, thereby guaranteeing the high-frequency response performance of the one-way valve.

[0030] Furthermore, the shape of the first through hole 11 in this embodiment can be set as a straight through hole or a tapered hole. When the first through hole 11 is set as a tapered hole, the diameter of the end facing the fluid inlet is larger than that of the end facing the valve 3. When the fluid flows in the forward direction, it can quickly enter the valve through the end with the larger diameter to push the valve 3, thereby improving the response performance when the fluid flows in the forward direction and reducing the turbulence disturbance when the fluid enters, thereby reducing the initial flow resistance. When the fluid flows in the reverse direction, the end with the smaller diameter can effectively reduce the fluid output and facilitate the valve 3 to close, thereby improving the response performance of the one-way valve when it is shut off in the reverse direction.

[0031] like Figure 1 and Figure 4 As shown, in this embodiment, a certain gap exists between the first plate 1 and the second plate 2 to form an interstitial space 4 for the valve 3 to move. This provides a certain range of opening for the second through-hole 31 at the edge, thereby increasing the flow rate at the edge of the valve 3 and improving efficiency. In one embodiment, the interstitial space 4 can be formed by etching or laser thinning the second plate 2 towards the surface of the valve 3 and corresponding to the open area 21, so that the height of the open area 21 is lower than the height of the edge connection position of the second plate 2. In another embodiment, the interstitial space 4 is also formed by setting a partition 5 or a protective film that exposes the open area 21 between the second plate 2 and the first plate 1, thereby creating a separation gap between the second plate 2 and the first plate 1.

[0032] In this embodiment, the first plate 1 serves as the basic component on the fluid inlet side. It is made of thin sheet metal or high-strength polymer material with suitable strength and hardness, effectively improving overall strength. The valve 3 is made of PI or PET film, which has low density and high hardness. This allows the valve 3 to complete the opening and closing (or vice versa) action in a very short time under high-frequency operating conditions, meeting the high-frequency operation requirements of the piezoelectric micropump. Simultaneously, the confinement area 22 effectively reduces material fatigue and extends service life.

[0033] likeFigure 2 and Figure 3 As shown, the specific workflow of this embodiment is as follows:

[0034] When the one-way valve is opened, fluid flows in from the outside of the first plate 1. The fluid pressure difference pushes the valve 3 to move towards the second plate 2. During the movement, a gap is formed between the valve 3 and the first plate 1. The first through hole 11 and the second through hole 31 are connected through the gap. The fluid flows out sequentially through the first through hole 11, the gap, the second through hole 31 and the open area 21.

[0035] When the one-way valve is closed, the fluid flows in the reverse direction. The reverse pressure difference directly pushes the valve 3 towards the first plate 1 through the open area 21, causing the valve 3 to quickly adhere to the surface of the first plate 1 and block the first through hole 11. At this time, the staggered distribution of the first through hole 11 and the second through hole 31 achieves a tight seal, effectively preventing leakage of the reverse fluid. This process is due to...

[0036] To obtain an order-of-magnitude estimate of the high-frequency response performance of the one-way valve in this embodiment, mathematical calculations are performed on the above working process. During the opening and closing process, the time it takes for valve 3 to move from the surface of the first plate 1 to just contact the surface of the second plate 2 is t1, and the moving distance is d1. The time required for valve 3 to move from contact with the surface of the second plate 2 to the maximum displacement is d2 is t2. Due to the requirements of high-frequency response, valve 3 needs to complete the time requirement of moving from the surface of the first plate 1 to the maximum displacement within 1 / 4 of the pressure cycle T, i.e., t1 + t2 < 1 / 4 T. Since valve 3 is not constrained by the second plate 2, it can be calculated solely by inertial motion. In this case, the time for valve 3 to move from the surface of the second plate 2 to just contact the surface of the first plate 1 is t3, and the moving displacement is d1 + d2.

[0037] The specific calculation process is as follows:

[0038] When the valve moves from the first plate 1 to just contact the second plate 2, the distance the valve 3 moves is equal to d1, and the moving time t1 is calculated through inertial motion:

[0039]

[0040] in:

[0041] d1 = D1 - δ (the distance that valve 3 moves to the lower surface of the second plate 2);

[0042] m = ρδ (valve surface density);

[0043] ρ is the density of the valve material;

[0044] δ represents the valve thickness;

[0045] P1 is the effective driving pressure difference when the valve opens.

[0046] When valve 3 comes into contact with the second plate 2, under the drive of alternating air pressure, the displacement of valve 3 after the impact is composed of the superposition of transient and steady-state responses. The vibration equation of valve 3 is:

[0047]

[0048] in:

[0049] γ is the damping coefficient (unit: Pa·s);

[0050] p0 is the air pressure amplitude (unit: Pa);

[0051] ρ is the valve density (unit: kg / m³) 3 ;

[0052] H represents the valve thickness (unit: m);

[0053] T0 is the valve pretension (unit: N / m);

[0054] In this invention, the steady-state response is small, and the transient response dominates. Therefore, neglecting the steady-state term, the displacement solution of the membrane impact is:

[0055]

[0056] in:

[0057] (Natural frequency);

[0058] (Because β << ω1);

[0059] (Transient coefficient);

[0060]

[0061] The maximum displacement of valve 3 occurs when the vibration velocity is zero, that is:

[0062]

[0063] Differentiating, we get:

[0064]

[0065] Solving for:

[0066] Time required for valve 3 to move to its maximum displacement

[0067] Maximum displacement is

[0068] At the center point r = 0 (J0(0) = 1), w max ≈B1.

[0069] Specifically, in this embodiment, the first plate 1 is a metal sheet with a thickness of 0.1 mm, and the diameter of the first through hole 11 is 150 μm; the valve 3 is a PI membrane with a thickness of 3 μm and a density of 1400 kg / m³. 3 The pretension is 50 N / m, the diameter of the second through hole 31 is set to 120 μm; the diameter of the open area 21 of the second plate 2 is set to 0.5 mm, and the height of the space 4 is set to d1 = 10 μm;

[0070] Under the operating conditions of a driving frequency of 20kHz, a forward effective pressure difference of 1.5kPa, and a reverse effective pressure difference of 3kPa, substituting into the above formula yields the following result:

[0071] Damping coefficient γ = 0.5 Pa·s;

[0072] The impact velocity was v = 2.67 m / s.

[0073] The time it takes for valve 3 to move from the first plate 1 to contact the second plate 2 when valve 3 opens (where m is the valve surface density, m=ρδ, ρ is the valve density, and δ is the valve thickness);

[0074] Time after valve 3 contacts second plate 3 and moves to maximum displacement

[0075] Maximum displacement of valve 3:

[0076] The total on-time t0 = t1 + t2 ≈ 10.5 μs;

[0077] Valve 3 closing time

[0078] Therefore, under the same operating frequency and pressure difference conditions, the opening time of the valve 3 in the existing one-way valve is approximately 11.1 μs, and the movement distance is 22 μm. Compared with this embodiment, the opening time is reduced by about 5%, the movement displacement of valve 3 is increased by about 3%, and the closing time is reduced by about 28%. In the practical application of the piezoelectric micropump, when the piezoelectric vibrator and pump chamber provide a pressure of 15 kPa, the output pressure is increased by about 8%, and the output flow rate is increased by about 20%.

[0079] In summary, this embodiment provides equidistant first through holes 11 and second through holes 31 on the surface of the first plate 1 and the surface of the valve 3, respectively, and provides an open area 21 on the second plate 2 at the location corresponding to the arrangement of the first through holes 11 and second through holes 31. When the fluid flows in reverse, the fluid can directly impact the surface of the valve 3 through the open area 21, causing the valve 3 to close the first through holes 11 and achieve reverse cutoff. This can effectively reduce the delay of fluid penetration into the narrow gap, thereby reducing the valve's closing response time. It can also reduce the pressure loss of fluid penetration between the second plate 2 and the valve 3, thereby effectively improving the high-frequency response performance of the valve.

[0080] The embodiments described above are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and modifications made by those skilled in the art based on this utility model shall fall within the scope of protection of this utility model.

Claims

1. A high-frequency, fast-response micropump check valve, comprising a first plate (1), a valve (3), and a second plate (2) stacked sequentially, characterized in that, The surface of the first plate (1) is provided with a plurality of uniformly arranged first through holes (11), and the surface of the valve (3) is provided with a plurality of uniformly arranged second through holes (31) at the position corresponding to the arrangement area of ​​the first through holes (11). The first through holes (11) and the second through holes (31) are staggered in the plane. The surface of the second plate (2) is formed with an open area (21) through it, and the open area (21) covers the arrangement area of ​​the first through holes (11) and the second through holes (31).

2. The high-frequency, fast-response check valve for a micropump according to claim 1, characterized in that, A space (4) is formed between the first plate (1) and the second plate (2). The valve (3) is movably disposed in the space (4) and can be switched to adhere to the surface of the first plate (1) or the surface of the second plate (2) in response to the fluid pressure difference.

3. The high-frequency, fast-response check valve for a micropump according to claim 2, characterized in that, The second plate (2) is thinned at the surface of the valve (3) and at the position corresponding to the open area (21) to form the spacer space (4).

4. The high-frequency, fast-response check valve for a micropump according to claim 2, characterized in that, A partition (5) or protective film is provided between the second plate (2) and the first plate (1) to separate the space (4) forming the interval, and the partition (5) or the protective film exposes the open area (21).

5. The high-frequency, fast-response check valve for a micropump according to claim 1, characterized in that, A plurality of first through holes (11) and a plurality of second through holes (31) are respectively gathered on the surface of the first plate (1) and the surface of the valve (3) to form a hole array. The hole array has a plurality of holes and is evenly spaced. The number of open areas (21) is the same as the number of holes and corresponds one-to-one.

6. The high-frequency, fast-response check valve for a micropump according to claim 5, characterized in that, A restriction region (22) for restricting the movement of the valve (3) is formed between adjacent open regions (21), and the restriction region (22) corresponds to the interval position between two adjacent aperture arrays.

7. A high-frequency, fast-response check valve for a micropump according to claim 1, characterized in that, The first through hole (11) is a straight through hole or a tapered hole, and the diameter of the air inlet end of the tapered hole is larger than the diameter of the end facing the valve (3).

8. A high-frequency, fast-response check valve for a micropump according to claim 1, characterized in that, The edges of the first plate (1) and the second plate (2) are fixed by laser welding.

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