Active one-way valve and piezoelectric pump based on ferrofluid

Abstract

The present invention discloses an active one-way valve and a piezoelectric pump based on ferromagnetic fluid, belonging to the technical field of piezoelectric pumps and one-way valve bodies, and comprises: two one-way valves of ferromagnetic fluid, and a piezoelectric pump chamber, wherein the one-way valve of the ferromagnetic fluid comprises: a three-way flow channel, a coil I, a coil II, an annular magnet I, an annular magnet II, and a ferromagnetic fluid column, wherein: the three-way flow channel is composed of a linear flow channel and an annular flow channel, the two ends of the linear flow channel are provided with openings, and the rest of the positions are closed, and the annular magnets I and II are symmetrically fixed on the upper and lower sides of the three-way flow channel; the piezoelectric pump chamber is composed of a piezoelectric vibrator and a piezoelectric pump chamber, and the two one-way valves are symmetrically sealed and connected to the left and right sides of the piezoelectric pump chamber. The ferromagnetic fluid columns in the inlet one-way valve and the outlet one-way valve rotate continuously, and alternately block the circulation of the one-way valve for a certain period of time, and the piezoelectric vibrator vibrates continuously, so as to realize the continuous pumping in and out of the fluid from the inlet to the outlet.

Description

Technical Field

[0001] The invention belongs to the technical field of piezoelectric pumps, and in particular relates to an active one-way valve and a piezoelectric pump based on ferromagnetic fluid. Background Art

[0002] At present, piezoelectric pump technology has gradually matured and has been applied in many fields; piezoelectric pumps have the advantages of small size, low noise, light weight and long life; piezoelectric pumps are divided into two types: with valve and without valve. Both types of piezoelectric pumps have inlets and outlets that act as a one-way conductor for the fluid, which is a one-way valve in a broad sense.

[0003] The valve technology of piezoelectric pumps has been developed for a long time, and has gradually formed its types and become mature, but there are still many problems as follows:

[0004] 1) The valve of a valved piezoelectric pump is generally a passive valve, which will only produce a unidirectional conduction property after the volume of the chamber changes. This makes the change of the valve body of the valved piezoelectric pump lag behind the vibration of the piezoelectric vibrator in time. Usually, when the piezoelectric vibrator is working, the working efficiency of the passive valve matched with it is low.

[0005] 2) The valveless piezoelectric pump adopts a special shape of flow channel design, which makes the resistance of fluid passing through one end relatively larger, making this section of the flow channel unidirectionally conductive on a macro scale. However, since it does not have a true valve, the valveless piezoelectric pump has poor air tightness and the flow rate of the pumped fluid is small. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of low valve working efficiency, poor air tightness and low pumping fluid flow rate existing in the above-mentioned piezoelectric pump technology field and the one-way valve body technology field, and to provide a piezoelectric pump based on a one-way valve based on ferromagnetic fluid and an active one-way valve based on ferromagnetic fluid.

[0007] A one-way valve based on ferromagnetic fluid, comprising: a three-way flow channel, a coil, a ring magnet, a ferromagnetic fluid column and a power supply;

[0008] The three-way flow channel includes: a straight flow channel and an annular flow channel. The straight flow channel passes through the center of the annular flow channel, intersects with the upper and lower flow channels of the annular flow channel, and communicates with each other, dividing the annular flow channel into two semi-circular flow channels that are symmetrical on the left and right, winding the coil, and connecting with the power supply.

[0009] The annular magnet is divided into a strong magnetic arc portion and a weak magnetic arc portion;

[0010] The annular magnet is arranged on the annular flow channel and matches the annular flow channel;

[0011] The strong magnetic arc portion has an arc of 70-100 degrees;

[0012] The ferromagnetic fluid column has an arc of 90-95 degrees and stays at the strong magnetic arc when the power is cut off.

[0013] The strong magnetic arc portion has an arc angle of 90 degrees and its strength is twice that of the weak magnetic arc portion.

[0014] The ferromagnetic fluid column is arranged in the annular flow channel;

[0015] The three-way flow channel is made of non-metallic material;

[0016] The three-way flow channel is made of glass material;

[0017] There is no capacitor yet, connected in parallel with the power supply;

[0018] There are two annular magnets, which are arranged on the upper and lower sides of the annular flow channel;

[0019] The active one-way valve comprises an inlet active one-way valve and an outlet active one-way valve, wherein the apex of the strong magnetic arc portion of the outlet active one-way valve is on the axis of the straight flow channel; the line connecting the apex of the strong magnetic arc portion of the inlet active one-way valve and the center of the annular magnet forms an angle of 90 degrees with the axis of the straight flow channel.

[0020] A piezoelectric pump based on an active one-way valve of a ferromagnetic fluid comprises: two active one-way valves, a piezoelectric pump and a delay circuit;

[0021] The inlet active check valve and the outlet active check valve are powered by the same power supply, and the power supply is provided with a capacitor connected in parallel with the power supply. The delay circuit is provided on the inlet active check valve circuit;

[0022] When the power supply supplies power to the piezoelectric pump, the piezoelectric pump is disconnected from the capacitor after the power supply is cut off.

[0023] The piezoelectric pump control method based on the active one-way valve of ferromagnetic fluid is characterized in that: when the power is supplied, the piezoelectric vibrator of the piezoelectric pump starts to vibrate at a fixed frequency fHz, and its period is T; the delay circuit first controls the ferromagnetic fluid liquid column in the outlet active one-way valve to rotate in the annular flow channel, and its period is T / 2; the ferromagnetic fluid liquid column in the inlet active one-way valve starts to rotate after the former by T / 2.

[0024] After the connection circuit is powered on, the delay circuit first controls the ferromagnetic fluid column in the outlet active one-way valve to rotate n circles in its flow channel in 1s, that is, the single-circuit period T=1 / n (s), and the frequency f=n; the ferromagnetic fluid column in the inlet active one-way valve starts to rotate after the former by T / 2 (s), and the delay time of the delay device is T / 2s.

[0025] The present invention provides a piezoelectric pump based on an active one-way valve of ferromagnetic fluid, which belongs to the technical field of piezoelectric pumps and one-way valve bodies. It includes: two one-way valves of ferromagnetic fluid, a piezoelectric pump chamber, and the one-way valve of ferromagnetic fluid includes: a three-way flow channel, a coil I, a coil II, an annular magnet I, an annular magnet II, and a ferromagnetic fluid column, wherein: the three-way flow channel is composed of a linear flow channel and an annular flow channel, the two ends of the linear flow channel are provided with openings, and the rest of the positions are closed, and the annular magnets I and II are symmetrically fixed on the upper and lower sides of the three-way flow channel; the piezoelectric pump chamber is composed of a piezoelectric vibrator and a piezoelectric pump chamber, and the two one-way valves are symmetrically sealed and connected to the left and right sides of the piezoelectric pump chamber. The ferromagnetic fluid columns in the inlet one-way valve and the outlet one-way valve rotate continuously, and alternately block the circulation of the one-way valve for a certain period of time, and the piezoelectric vibrator vibrates continuously to realize the continuous pumping in and out of the fluid from the outlet to the inlet.

[0026] In summary, the piezoelectric pump with an active one-way valve based on ferromagnetic fluid provided by the present invention has the following beneficial effects:

[0027] The piezoelectric pump of the present invention is provided with an active one-way valve based on ferromagnetic fluid, in which a ferromagnetic fluid is arranged in a three-way flow channel, which is aggregated together under the action of the molecular surface gravity. Since the ferromagnetic fluid has high viscosity and is subjected to the gravitational force of the magnet, it will eventually form a liquid column with a certain shape and fluid characteristics; after the coil is energized, each small piece of ferromagnetic fluid is subjected to the tangential combined force given by the energized coil along the semicircular flow channel, which is manifested macroscopically as the injected ferromagnetic fluid starting to accelerate along a circular trajectory in the circular flow channel, and after reaching a certain speed, the tangential force given by the energized coil on the entire section of ferromagnetic fluid, the supporting force and friction force provided by the pipeline and the centripetal force of the entire section of fluid are balanced, so that the ferromagnetic fluid rotates in the circular flow channel at a fixed angular velocity, and each time it passes through a linear flow channel, it will form a great obstruction to the fluid or fluid passing through the flow channel, thereby forming the effect of a valve that obstructs the passage of the fluid.

[0028] The piezoelectric pump of the present invention is provided with an active one-way valve based on ferromagnetic fluid to realize one-way pumping of fluid. The vibration of the piezoelectric vibrator causes the change of the chamber volume to generate pressure. When the piezoelectric vibrator vibrates, it continuously inhales and pumps out fluid from two active one-way valves cooperating with the piezoelectric vibrator, thereby realizing one-way transmission of the fluid.

[0029] The magnetic force on the ferromagnetic fluid in the three-way flow channel is much greater than the impact force brought by the fluid, and it is also affected by its own gravity, so the deformation of the ferromagnetic fluid caused by the tangential force caused by the fluid entering the flow channel can be almost ignored. Therefore, when working or static, the ferromagnetic fluid can be regarded as maintaining a fixed columnar shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1It is a schematic diagram of the overall structure and explosion structure of a piezoelectric pump of an active one-way valve based on ferromagnetic fluid of the present invention;

[0031] Figure 2 The invention discloses a three-way flow channel of an active one-way valve based on ferromagnetic fluid;

[0032] Figure 3 It is a schematic diagram of the specific structure of a ferromagnetic fluid active one-way valve of a piezoelectric pump based on a ferromagnetic fluid active one-way valve of the present invention;

[0033] Figure 4 It is a schematic diagram of the working principle of a piezoelectric pump of an active one-way valve based on ferrofluid of the present invention;

[0034] Figure 5 It is a schematic diagram of the strong magnetic and weak magnetic distribution areas of the annular magnet in the ferrofluid active one-way valve of the present invention;

[0035] Figure 6 It is a timing logic diagram of a ferrofluid active one-way valve in operation according to the present invention;

[0036] Figure 7 It is a circuit connection diagram of an active one-way valve based on ferrofluid and a piezoelectric pump working in cooperation with each other in the present invention;

[0037] Figure 8 This is a schematic diagram of the working state of a piezoelectric pump of an active one-way valve based on ferromagnetic fluid according to Example 3 of the present invention.

[0038] In the attached picture:

[0039] 1. Piezoelectric ceramics; 2. Metal substrate; 3. Piezoelectric pump chamber; 4. Coil I; 5. Ring magnet I; 6. Ferrofluid liquid column; 7. Three-way flow channel; 71. Magnet frame I; 72. Ring flow channel; 73. Straight flow; 74. Magnet frame II; 8. Ring magnet II; 9. Coil II; 10. Capacitor; 12. Power supply; 81. Strong magnetic arc part; 82. Weak magnetic arc part. DETAILED DESCRIPTION

[0040] Embodiment 1:

[0041] See also Figure 1-7 , an active one-way valve based on ferromagnetic fluid, comprising: a power supply 12, a glass three-way flow channel 7, a coil I 4, a coil II 9, a ring magnet and a ferromagnetic fluid column 6;

[0042] The glass three-way flow channel 7 includes a straight flow channel 73 and an annular flow channel 72. The straight flow channel 73 passes through the annular flow channel 72, intersects with the upper and lower ends thereof, and communicates with each other, dividing the annular flow channel into two arc flow channels that are symmetrical on the left and right. The coils Ⅰ4 and Ⅱ9 are made of the same copper wire, which is wound around the two arc flow channels in a manner of 2 turns / mm. The coils Ⅰ4 and Ⅱ9 are prepared with the same winding direction. The coils Ⅰ4 and Ⅱ9 (both ends of the copper wire) are connected to the power supply 12.

[0043] The two ends of the linear flow channel 73 are provided with interfaces connected to the pipeline of the piezoelectric pump;

[0044] The annular magnet is divided into a strong magnetic arc portion 81 and a weak magnetic arc portion 82. The strong magnetic arc portion 81 has an arc of 90 degrees and a strength of 100 Gauss, and the weak magnetic arc portion 82 has an arc of 270 degrees and a strength of 50 Gauss.

[0045] The annular magnets include annular magnet I5 and annular magnet II8, which are respectively arranged above and below the annular flow channel 72 and have the same diameter as the annular flow channel 72.

[0046] The ferromagnetic fluid column 6 is an arc-shaped column arranged in the annular flow channel, and the arc is 90 degrees. The ferromagnetic fluid is poured into the annular flow channel, shaken, and the arc-shaped column is formed under the action of the strong magnetic arc part 81 of the annular magnet.

[0047] Embodiment 2:

[0048] See also Figure 1 , 6 7. A piezoelectric pump based on an active one-way valve of a ferromagnetic fluid, comprising: two active one-way valves (an inlet active one-way valve and an outlet active one-way valve), and a piezoelectric pump. The two active one-way valves are symmetrically sealed and connected to the left and right sides of a piezoelectric pump chamber 3.

[0049] The coils of the inlet active check valve and the outlet active check valve are powered by the same power supply 12, and the power supply 12 is provided with a capacitor 10 connected in parallel with the power supply 12. The inlet active check valve is provided with a delay circuit; the power supply is delayed relative to the outlet active check valve;

[0050] After the connection circuit is powered on, the piezoelectric vibrator starts to vibrate at a fixed frequency fHz, and its period is T; the delay circuit first controls the ferromagnetic fluid column 6 in the outlet active one-way valve to rotate in the annular flow channel, and the period is T / 2; the ferromagnetic fluid column 6 in the inlet active one-way valve starts to rotate after the former by T / 2 (s), and the delay time of the delay device is T / 2 (s).

[0051] The present invention provides a piezoelectric pump based on an active one-way valve of ferromagnetic fluid, and its working process and working principle are as follows:

[0052] 1. Before work:

[0053] See attached Figure 1-3 , assemble the piezoelectric pump and connect the wires and capacitor 10, then add ferromagnetic fluid into the annular flow channel 72, shake the annular flow channel, and make the ferromagnetic fluid stay in the strong magnetic arc portion 81. Since the ferromagnetic fluid liquid column 6 is subjected to a stronger magnetic force than the weak magnetic arc portion 82, the ferromagnetic fluid liquid column 6 will stay just above the strong magnetic arc portion 81, and the two are symmetrical along the same center line; since the ferromagnetic fluid needs to change its own shape to maintain the state of lowest energy, the ferromagnetic fluid will form a liquid column (ferromagnetic fluid liquid column 6) under the magnetic force of the upper and lower permanent magnets and its own internal force, and has a certain ability to maintain its shape.

[0054] 2. When working:

[0055] (1) When power is turned on, the ferromagnetic fluid column 6 in the outlet active one-way valve rotates first, and the ferromagnetic fluid column 6 in the inlet active one-way valve starts to rotate after a delay of T / 2 (s); after a period of time, the ferromagnetic fluid column 6 in the inlet active one-way valve reaches a balanced state and rotates at a speed of 1 / T turns / s;

[0056] (2) After power is turned on, the DC power supply supplies power to the piezoelectric vibrator after a time of Ts seconds. Ts is the time from the power-on of the one-way valve to the stable rotation of the ferromagnetic fluid column. This is the adjustment time of the active one-way valve after power is turned on;

[0057] (3) The ferrofluid liquid column 6 fills 1 / 4 of the annular flow channel. Therefore, every time the ferrofluid liquid column 6 rotates one circle (Ts), it will be turned on for T / 2 (s), that is, it will be turned off for T / 2 (s). Assuming that there is a mark at one end of the liquid column, when the mark is in the green area, the valve is fully open, and when the mark is in the red area, the valve is fully closed. Therefore, the ferrofluid liquid column 6 in the annular flow channel 72 cuts off the airflow twice for every rotation of the ferrofluid liquid column 6, that is, the ferrofluid liquid column 6 that rotates 1 / T circle every second can change the airflow conduction characteristics 2n times; the ferrofluid liquid column 6 in the inlet active one-way valve (a) and the outlet active one-way valve (b) rotate successively, and alternately block the flow of the one-way valve once at an interval of T / 2 (s);

[0058] (4) The vibration period of the piezoelectric vibrator is T, that is, the time required to complete one deformation cycle is T.

[0059] 1) See attached Figure 6 When the piezoelectric vibrator deforms upward, the volume of the chamber increases and the pressure decreases; the inlet active one-way valve (a) is turned on and the outlet active one-way valve (b) is turned off; at the inlet, a pressure difference is formed inside and outside, and the fluid is pumped into the pump chamber through the inlet active one-way valve (a).

[0060] 2) See attached Figure 6 When the piezoelectric vibrator deforms downward, the volume of the chamber becomes smaller and the pressure increases; the one-way valve at the inlet is cut off, and the one-way valve at the outlet is turned on; at the outlet, a pressure difference is formed inside and outside, and the fluid is pumped out through the outlet active one-way valve.

[0061] When the piezoelectric pump is working, the above process is repeated and carried out continuously in a very short time. On a macro scale, the fluid can be continuously pumped in and out from the outlet to the inlet.

[0062] 3. After work:

[0063] Turn off the power switch, such as Figure 7 As shown, the switch is a linkage switch. After it is turned off, the piezoelectric pump is no longer connected to the circuit. The capacitor 10 only forms a parallel circuit with the inlet active check valve and the outlet active check valve. The inlet active check valve and the outlet active check valve continue to work under the power supply of the capacitor 10, and at the same time, the current gradually decreases with the change of time. (Assume The current through the coil when equilibrium is reached is The critical current is the tangential force caused by the current that can push the liquid column through the strong magnetic region. is the critical current for pushing the liquid column through the weak magnetic region) when the current is Down to After that, the liquid column can no longer pass through the strong magnetic area and is decelerated by the magnetic force, but it can continue to move when passing through the weak magnetic area, and so on. Before that, the liquid column had already stayed in the strong magnetic area and remained stable. After a period of time, the electricity stored in the capacitor was completely exhausted and the workflow ended.

[0064] Embodiment 3:

[0065] See also Figure 3 , 8 A piezoelectric pump based on an active one-way valve of ferromagnetic fluid, comprising: an inlet active one-way valve, an outlet active one-way valve, and a piezoelectric pump, wherein the vertex of the strong magnetic arc portion 81 of the outlet active one-way valve is on the axis of the linear flow channel 73; the line connecting the vertex of the strong magnetic arc portion 81 of the inlet active one-way valve and the center of the annular magnet forms an angle of 90 degrees with the axis of the linear flow channel 73. Other features are the same as those of the active one-way valve based on ferromagnetic fluid described in Example 1.

Claims

1. An active one-way valve based on ferrofluid, characterized in that: It includes a three-way flow channel (7), a coil, a ring magnet, a ferromagnetic fluid column (6) and a power source (12); The three-way flow channel (7) comprises: a linear flow channel (73) and an annular flow channel (72); the linear flow channel (73) passes through the center of the annular flow channel (72), intersects with the upper and lower flow channels of the annular flow channel (72), and communicates with each other, thereby dividing the annular flow channel into two semicircular flow channels that are symmetrical on the left and right; the coil is wound around the annular flow channel and is electrically connected to a power source (12); The annular magnet is divided into a strong magnetic arc portion (81) and a weak magnetic arc portion (82); The annular magnet is arranged on the annular flow channel (72) and matches the annular flow channel (72); The ferromagnetic fluid column (6) is arranged in the annular flow channel; The three-way flow channel (7) is made of non-metallic material; The strong magnetic arc portion (81) has an arc angle of 70-100 degrees; The ferromagnetic fluid column (6) has an arc of 90-95 degrees and stays at the strong magnetic arc portion (81) when the power supply (12) is turned off; There are two annular magnets, which are arranged on the upper and lower sides of the annular flow channel (72).

2. The active one-way valve based on ferromagnetic fluid according to claim 1, characterized in that: The strength ratio of the strong magnetic arc portion (81) to the weak magnetic arc portion (82) is 10:3-7.

3. The active one-way valve based on ferrofluid according to claim 2, characterized in that: The active one-way valve comprises an inlet active one-way valve and an outlet active one-way valve, wherein the apex of the strong magnetic arc portion (81) of the outlet active one-way valve is on the axis of the linear flow channel (73); and the line connecting the apex of the strong magnetic arc portion (81) of the inlet active one-way valve and the center of the annular magnet forms an angle of 90 degrees with the axis of the linear flow channel (73).

4. The active one-way valve based on ferromagnetic fluid according to claim 3, characterized in that: The strong magnetic arc portion (81) has an arc angle of 90 degrees and its strength is twice that of the weak magnetic arc portion (82).

5. The active one-way valve based on ferromagnetic fluid according to claim 4, characterized in that: A capacitor (10) is also provided and connected in parallel with the power source (12).

6. The active one-way valve based on ferrofluid according to claim 5, characterized in that: The three-way flow channel (7) is made of glass material.

7. A piezoelectric pump based on an active one-way valve of a ferrofluid, characterized in that: The active one-way valve based on ferromagnetic fluid as claimed in claim 3 is used at the inlet and outlet of the pump chamber of the piezoelectric pump.

8. The piezoelectric pump based on the active one-way valve of ferrofluid according to claim 7, characterized in that: The inlet active one-way valve and the outlet active one-way valve are powered by the same power supply (12), and a delay circuit is provided on the circuit of the inlet active one-way valve.

9. The piezoelectric pump based on the active one-way valve of ferrofluid according to claim 8, characterized in that: When the power supply (12) supplies power to the piezoelectric pump, after the power supply (12) is powered off, the piezoelectric pump is disconnected from the capacitor (10); a delay circuit is also provided on the piezoelectric pump circuit.

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