CN115822933A - A piezoelectric jet pump - Google Patents

Abstract

The invention relates to a piezoelectric jet flow pump, comprising: a pump body, a flexible diaphragm, an inlet channel, a piezoelectric vibrator, a pump cavity, screws, a valve, an outlet channel, and a conical pin. Among them, the inlet channel is set at the pressure node of the piezoelectric vibrator; the outlet channel is set at the upper part of the pump body where the pressure is the highest; the piezoelectric vibrator is bonded to the flexible diaphragm; the valve uses a microvalve array to increase the natural frequency. The piezoelectric jet pump uses the acoustic flow effect to drive the fluid, and its principle is as follows: According to the acoustic flow effect, that is, when the piezoelectric vibrator vibrates to generate ultrasonic waves that propagate in the fluid, the sound pressure will change in gradient along the sound beam propagation direction, In this way, a jet flowing from the piezoelectric vibrator to the outlet channel is formed to realize the pumping of the fluid. The use of a flexible diaphragm optimizes the sound pressure field and increases the output performance of the pump. The trumpet-shaped pump cavity with high aspect ratio is used to enhance the acoustic flow effect and generate larger jet flow. Better pumping with highly responsive valve rectification. Take advantage of the high energy density of piezoelectric materials.

Description

A piezoelectric jet pump

technical field

The invention relates to the field of microfluid drive, in particular to a piezoelectric jet pump.

Background technique

Microfluidic control systems are widely used in the fields of microchemical analysis systems, electronic cooling systems, and portable medical systems. Designing robust microfluidic control systems requires efficient and reliable fluid delivery mechanisms. With the development of science and technology, human beings have put forward requirements for miniaturized fluid control equipment, simple structure, independence and no interference to fluid samples, continuous and stable output, and precise control of flow. Traditional pumps cannot meet the above requirements. Requirements, for example, traditional air cooling systems based on electromagnetic motors, which are bulky, consume a lot of energy, are inefficient and produce high noise during operation, which requires a more efficient cooling system to deal with the heat dissipation problem, thereby improving the performance of the device, meet the needs of human life. The piezoelectric pump made according to the inverse piezoelectric effect has the advantages of simple structure, small size, independent and non-interference to fluid samples, and low cost. It can well meet the needs of human life. It is used in medical equipment, computer chip heat dissipation, Applications include battery fuel delivery, assisted artificial heart pumps, avionics, and more.

The output performance of most existing piezoelectric pumps is limited by the valve, and the operating frequency is low. Due to the low operating frequency of the valve, the valve is easily damaged and has hysteresis when working in a high-frequency state, which leads to the poor performance of the piezoelectric pump when working in a high-frequency state, and fails to take advantage of the high energy density of piezoelectric materials. play out. Moreover, the piezoelectric pump has unavoidable pulsation and noise problems when it works in a low-frequency state.

Contents of the invention

In order to solve the pulsation and noise problems existing in the current piezoelectric pump and improve the performance of the pump, the present invention proposes a piezoelectric jet pump. Based on the principle of standing wave resonance, the flexible diaphragm is used to optimize the sound pressure field and improve the output performance of the pump. The horn-shaped pump cavity with high aspect ratio focuses the ultrasonic wave generated by the piezoelectric vibrator, forming a high sound pressure in the pump cavity and enhancing the acoustic flow effect; the valves of the microvalve array are used for rectification to achieve better pumping ; The piezoelectric jet pump uses the acoustic flow effect to drive the fluid, and the working frequency of the pump is raised to the ultrasonic range, and the advantages of the high energy density of the piezoelectric material are brought into play, the problems of pulsation and noise are solved, and fast response and no sound are realized. .

To achieve the above object, the present invention adopts the following technical solutions:

A piezoelectric jet pump, comprising: a pump body (1), a flexible diaphragm (2), an inlet channel (3), a piezoelectric vibrator (4), a pump chamber (5), screws (6), and a valve (7) , outlet channel (8), tapered pin (9). Wherein, the piezoelectric vibrator (4) is glued on the flexible diaphragm (2); the inlet passage (3) is arranged at the pressure node of the piezoelectric vibrator (4); the outlet passage (8) is arranged at the pump body ( 1) The upper part has the highest pressure; the valve (7) adopts a microvalve array to increase the natural frequency, and is composed of an inlet layer, a disc layer, and an outlet layer. The middle of the outlet layer is depressed, and there is a little gap between the middle and the disc layer , so as to open and close the valve clack; the valve (7) is installed on the pump body (1) with the highest pressure by a conical pin (9), which can quickly respond to pressure changes; the pump chamber (5) is a horn with a high aspect ratio The pump body (1) and the flexible diaphragm (2) are connected by screws (6), which can focus the ultrasonic waves generated by the piezoelectric vibrator (4).

When working, the piezoelectric vibrator (4) vibrates to generate ultrasonic waves. When the ultrasonic wave propagates in the fluid, it will produce an acoustic flow effect, that is, a gradient change of sound pressure will be generated along the propagation direction of the sound beam, thereby forming a flow from the piezoelectric vibrator (4) to the outlet. The jet flow of the channel (8) realizes the pumping of the fluid. Based on the principle of standing wave resonance, the flexible diaphragm (2) is used to optimize the sound pressure field and improve the output performance of the pump. Since the attenuation of ultrasonic waves in the fluid decreases with the increase of the propagation distance, the horn-shaped pump chamber (5) with a high aspect ratio is used to enhance the acoustic flow effect and generate larger jet flow. The high-response valve (7) is used for rectification to achieve better pumping, and the pumping rate of the fluid can be adjusted by adjusting the amplitude of the input sound pressure.

The piezoelectric jet pump has the advantages of small pulsation, no noise, small volume, large flow rate, high pressure, etc., and has high application potential in the fields of microfluidics, sonochemistry, electronic cooling and mixing.

Description of drawings

Fig. 1 is an isometric test diagram of a piezoelectric jet pump;

Fig. 2 is a structural schematic diagram of a piezoelectric jet pump;

Fig. 3 is a structural explosion diagram of a microvalve array valve;

Fig. 4 is a working principle diagram of a piezoelectric jet pump.

Description of reference signs: 1—pump body, 2—flexible diaphragm, 3—inlet channel, 4—piezoelectric vibrator, 5—pump chamber, 6—screw, 7—valve, 7—1—inlet layer, 7—2— Disc layer, 7-2-1-disc unit, 7-3-exit layer, 8-exit channel, 9-taper pin.

Detailed ways

In order to make the technical solution and technical effect of the present invention clearer, the present invention will be further described in detail through specific implementation methods below in conjunction with the accompanying drawings.

The specific structure and working principle of a piezoelectric jet pump according to an embodiment of the present invention will be described below with reference to FIGS. 1-4 .

Referring to Figure 1-2, a piezoelectric jet pump is characterized in that it consists of a pump body 1, a flexible diaphragm 2, an inlet passage 3, a piezoelectric vibrator 4, a pump chamber 5, a screw 6, a valve 7, an outlet passage 8 and Conical pin 9 forms. The piezoelectric vibrator 4 is pasted on the flexible diaphragm 2; the pressure node of the piezoelectric vibrator 4 has an orifice as the inlet channel 3; the outlet channel 8 with the valve 7 is set at the upper part of the pump body 1 where the pressure is the highest; the pump chamber 5 is The horn type with high aspect ratio is formed by connecting the pump body 1 and the flexible diaphragm 2 through screws 6, which can focus the ultrasonic waves generated by the piezoelectric vibrator 4.

With reference to Fig. 3, a kind of piezoelectric jet pump is characterized in that: adopt the natural frequency of the valve 7 that the mode of microvalve array improves; Valve 7 is installed in the pressure maximum place of pump body 1 top with conical pin 9; Microvalve The valves 7 of the array are composed of an inlet channel layer, a valve disc layer and an outlet channel layer. The middle of the outlet channel layer is depressed, and there is a certain gap with the valve disc layer to facilitate the opening and closing of the valve disc layer. Valve 7 responds quickly to changes in differential pressure without limiting pump performance. The material of the valve 7 can be thin sheets with strong elasticity such as nickel, nickel-titanium alloy, stainless steel, polyester, etc.

Referring to Fig. 4, when working, a sinusoidal signal is applied to the piezoelectric vibrator 4, and the piezoelectric vibrator 4 vibrates to generate ultrasonic waves. When the ultrasonic waves propagate in the fluid, an acoustic flow effect is generated, that is, a gradient change of sound pressure is generated along the sound beam propagation direction. In this way, a jet flowing from the piezoelectric vibrator 4 to the outlet channel 8 is formed to realize the pumping of the fluid. Based on the principle of standing wave resonance, the flexible diaphragm 2 is used to optimize the sound pressure field and improve the output performance of the pump. Since the attenuation of ultrasonic waves in the fluid decreases with the increase of the propagation distance, the horn-shaped pump chamber 5 with a high aspect ratio is used to enhance the acoustic flow effect and generate larger jet flow. Use high-response valve 7 rectification to achieve better pumping, and the pumping rate of the fluid can be adjusted by adjusting the amplitude of the input sound pressure.

Claims (4)

1. A piezoelectric jet pump, characterized in that: said piezoelectric jet pump utilizes the acoustic flow effect to drive the fluid, and its principle is as follows: according to the acoustic flow effect, the piezoelectric vibrator (4) vibrates to generate ultrasonic waves When propagating in the fluid, the sound pressure will change gradiently along the propagation direction of the sound beam, thereby forming a jet flowing from the piezoelectric vibrator (4) to the outlet channel (8), and realizing the pumping of the fluid; based on the principle of standing wave resonance, a flexible diaphragm is used (2) Optimize the sound pressure field and improve the output performance of the pump; since the attenuation of the ultrasonic wave in the fluid decreases with the increase of the propagation distance, the use of a high aspect ratio trumpet-shaped pump cavity (5) enhances the sound flow effect and produces a larger the jet flow; using high-response valve (7) rectification to achieve better pumping; the piezoelectric jet pump includes: pump body (1), flexible diaphragm (2), inlet channel (3), pressure Electric vibrator (4), pump cavity (5), screw (6), valve (7), outlet channel (8), tapered pin (9). 2. A piezoelectric jet pump according to claim 1, characterized in that: the inlet channel (4) is set at the pressure node of the piezoelectric vibrator (4); the outlet channel (8) is set at the pump body (1) The upper part where the pressure is the highest; the piezoelectric vibrator (4) is bonded to the flexible diaphragm (2). 3. A piezoelectric jet pump according to claim 1, characterized in that: the pump cavity (5) can focus the ultrasonic wave generated by the piezoelectric vibrator (4). 4. A kind of piezoelectric jet pump according to claim 1, characterized in that: the valve (7) adopts a microvalve array to improve the natural frequency, and is composed of an inlet layer, a disc layer, and an outlet layer; The valve (7) is installed on the upper part of the pump body (1) by a tapered pin (9) where the pressure is the highest, and can quickly respond to pressure changes; the material of the valve (7) can be nickel, nickel-titanium alloy, stainless steel, polyester, etc. Strong flakes.

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