CN102896061B - Piezoelectric micro-jet device based on bending vibration sandwich transducer - Google Patents

Abstract

The invention relates to a piezoelectric micro-spraying device based on a bending-vibration sandwich transducer, and relates to the technical field of piezoelectric micro-spraying. It solves the common problems of low energy utilization rate and limited improvement of spraying quantity in existing piezoelectric micro-spraying devices adopting patch structure. The two piezoelectric ceramic sheets of the present invention are arranged between the rear end cover and the front end cover, and an electrode sheet is arranged between the rear end cover and one piezoelectric ceramic sheet, and between the front end cover and another piezoelectric ceramic sheet ; There are two coplanar electrode sheets with a gap between the two piezoelectric ceramic sheets; the two piezoelectric ceramic sheets are polarized along the thickness direction, and the polarization directions are opposite; the nozzle has a conical inner cavity , the bottom of the conical inner cavity is provided with a spray through hole, and one side of the upper part of the conical inner cavity is provided with an inflow hole; the bottom surface of the end of the front end cover is fixedly connected with the top surface of the vibrating piece, and the bottom surface of the vibrating piece is connected to the conical shape of the nozzle. The large open end of the lumen is completely covered. The invention is applicable to the fields of drug injection, printing and imaging, micro-lubrication and the like.

Description

Piezoelectric Micro-injection Device Based on Bending Vibration Sandwich Transducer

technical field

The invention relates to a piezoelectric micro-injection device based on a bending-vibration sandwich transducer, and belongs to the technical field of piezoelectric micro-injection.

Background technique

Piezoelectric micro-spray technology is a kind of inverse piezoelectric effect of piezoelectric ceramics, which excites vibration in the elastic body and interacts with the liquid in the liquid chamber. The pressure wave generated is transmitted to the nozzle to cause the liquid jet to be ejected from the nozzle. And then atomized into droplets. The size and speed of the droplet are related to the amplitude and frequency of the driving voltage. Piezoelectric injection technology does not cause physical/chemical changes in the injected liquid, and has almost no damage to the liquid itself; in addition, piezoelectric injection has the outstanding advantages of flexible and simple control, low power consumption, small size and easy integration. It has very broad application value in the fields of drug injection, printing and imaging, and micro-lubrication.

However, due to the simplicity of the excitation principle and the simplicity of the theoretical analysis method, most of the current mature piezoelectric micro-spray devices use metal elastic sheets pasted with piezoelectric ceramic sheets for excitation. Piezoelectric ceramics work at low electromechanical coupling efficiency. In the d ₃₁ mode, the energy utilization rate is low; in addition, the vibration intensity obtained by this vibration mode is low, which limits the improvement of the injection volume of this type of device.

Contents of the invention

In order to solve the common problems of low energy utilization rate and limited injection quantity improvement in existing piezoelectric micro-injection devices with a patch structure, the present invention provides a piezoelectric micro-injection device based on a bending vibration sandwich transducer .

The piezoelectric microspray device based on the bending vibration sandwich transducer of the present invention includes a bending vibration sandwich transducer 1, a vibrating plate 2 and a nozzle 3; the bending vibration sandwich transducer 1 includes a rear end cover 1-1, a front end Cover 1-2, two piezoelectric ceramic sheets 1-3 and four electrode sheets 1-4, the two piezoelectric ceramic sheets 1-3 are sequentially arranged between the rear end cover 1-1 and the front end cover 1-2 An electrode piece 1-4 is arranged between the rear end cover 1-1 and a piezoelectric ceramic piece 1-3, and an electrode piece is arranged between the front end cover 1-2 and another piezoelectric ceramic piece 1-3 1-4; two electrode sheets 1-4 are arranged between two piezoelectric ceramic sheets 1-3, and the two electrode sheets 1-4 are located on the same plane, and there is an electrode sheet between the two electrode sheets 1-4. There is a gap; the two piezoelectric ceramic sheets 1-3 are polarized along the thickness direction, and the polarization directions of the two piezoelectric ceramic sheets 1-3 are opposite; the nozzle 3 has a conical inner cavity 3-1, conical The bottom of the inner chamber 3-1 is provided with a spray through hole 3-3, and the upper side wall of the conical inner chamber 3-1 is provided with an inlet hole 3-2; The top surface is fixedly connected, and the bottom surface of the vibrating piece 2 is fixedly connected to the edge of the large opening end of the conical inner cavity 3-1 in the nozzle 3, and completely covers the large opening end of the conical inner cavity 3-1 in the nozzle 3.

When the piezoelectric micro-spray device based on the bending vibration sandwich transducer of the present invention is in operation, the bending vibration transducer adopts two-phase AC voltage signals with a phase difference of 180 degrees in time for excitation, and is arranged on the front end cover and the piezoelectric ceramic The electrode sheets between the two piezoelectric ceramic sheets and the electrode sheets arranged between the rear end cover and the piezoelectric ceramic sheet are connected to the common terminal of the excitation signal, and the two electrode sheets arranged between the two piezoelectric ceramic sheets are respectively connected to the two-phase drive signal , and then through the alternate stretching vibration on both sides of the piezoelectric ceramic sheet to realize the excitation of the bending vibration of the transducer, and further drive the vibration piece connected to the end of the front cover to generate bending vibration, the vibration piece will interact with the liquid in the conical cavity, The generated pressure wave is transmitted to the nozzle and finally realizes the ejection of the liquid jet from the nozzle. By controlling the magnitude of the excitation voltage applied to the piezoelectric ceramics, precise control of the injection volume can be achieved.

In the present invention, the piezoelectric ceramic works in the d33 mode with high electromechanical coupling efficiency, and the energy utilization rate is high, which can fully improve the energy utilization rate and effectively increase the amplitude of the particle at the end of the front cover, and finally effectively increase the injection volume of the device.

The piezoelectric micro-injection device based on the bending-vibration sandwich transducer of the present invention has the advantages of high energy utilization rate, large-dose injection, good working stability and the like.

Description of drawings

Fig. 1 is the cross-sectional view of the piezoelectric micro-injection device based on the bending-vibration sandwich transducer according to the present invention, and Fig. 2 is a bending-vibration sandwich transducer in the piezoelectric micro-injection device based on the bending-vibration sandwich transducer shown in Fig. 1 Fig. 3 is a partial view of the bending vibration sandwich transducer shown in Fig. 2, and Fig. 4 is a structural schematic diagram of the nozzle in the piezoelectric micro-injection device based on the bending vibration sandwich transducer shown in Fig. 1, Fig. 5 is a schematic diagram of the working principle of the piezoelectric micro-injection device based on the bending vibration sandwich transducer shown in Fig. 1 .

Detailed ways

Specific embodiment 1: This embodiment is described in conjunction with Fig. 1 to Fig. 4, the piezoelectric micro-injection device based on the bending vibration sandwich transducer described in this embodiment includes a bending vibration sandwich transducer 1, a vibrating plate 2 and The nozzle 3; the bending vibration sandwich transducer 1 includes a rear end cover 1-1, a front end cover 1-2, two piezoelectric ceramic sheets 1-3 and four electrode sheets 1-4, the two piezoelectric ceramic sheets 1-3 are sequentially arranged between the rear end cover 1-1 and the front end cover 1-2, an electrode sheet 1-4 is arranged between the rear end cover 1-1 and a piezoelectric ceramic sheet 1-3, and the front end cover 1 An electrode sheet 1-4 is arranged between -2 and another piezoelectric ceramic sheet 1-3; two electrode sheets 1-4 are arranged between two piezoelectric ceramic sheets 1-3, and the two electrode sheets 1 -4 is located on the same plane, and there is a gap between the two electrode sheets 1-4; the two piezoelectric ceramic sheets 1-3 are polarized along the thickness direction, and the poles of the two piezoelectric ceramic sheets 1-3 The spraying direction is opposite; the nozzle 3 has a conical inner cavity 3-1, the bottom of the conical inner cavity 3-1 has a spray through hole 3-3, and the upper side wall of the conical inner cavity 3-1 has an inlet Orifice 3-2; the bottom surface of the end of the front end cover 1-2 is fixedly connected to the top surface of the vibrating piece 2, and the bottom surface of the vibrating piece 2 is fixedly connected to the edge of the large opening end of the conical inner cavity 3-1 in the nozzle 3, And the large opening end of the conical inner cavity 3-1 in the nozzle 3 is completely covered.

When the piezoelectric micro-spray device based on the bending vibration sandwich transducer of this embodiment is applied, the piezoelectric ceramic sheet is excited by two-phase AC voltage signals with a phase difference of 180 degrees in time, and is arranged on the front end cover 1- 2 and the piezoelectric ceramic sheet 1-3 and the electrode sheet 1-4 arranged between the rear end cover 1-1 and the piezoelectric ceramic sheet 1-3 are all connected to the common end of the excitation signal, and are arranged on the two piezoelectric ceramic sheets. The two electrode sheets 1-4 between the electric ceramic sheets 1-3 are respectively connected to the two-phase drive signals, and then the excitation of the bending vibration of the transducer is realized through the alternate stretching vibration on both sides of the piezoelectric ceramic sheet, which further drives the connection at the front end The vibrating piece at the end of the cover produces bending vibration, and the vibrating piece will interact with the liquid in the conical cavity, and the pressure wave generated will be transmitted to the nozzle, and finally the liquid jet will be ejected from the nozzle; the conical cavity 3-1 will pass through the inflow Hole 3-2 is connected to an external fluid supply system.

Embodiment 2: The difference between this embodiment and the piezoelectric micro-injection device based on the flexural vibration sandwich transducer described in Embodiment 1 is that the section of the longitudinal vibration piezoelectric ceramic sheet 1-3 is square or circular , which can simplify the processing and assembly process.

Embodiment 3: The difference between this embodiment and the piezoelectric micro-spray device based on the bending vibration sandwich transducer described in Embodiment 1 is that the connection position between the front end cover 1-2 and the vibrating plate 2 is located at the vibrating plate 2 In this way, the bending vibration of the transducer 1 can be effectively used to excite the bending vibration of the vibrating piece 2 .

Embodiment 4: The difference between this embodiment and the piezoelectric micro-spray device based on the flexural vibration sandwich transducer described in Embodiment 1 is that the front end cover 1 - 2 and the vibrating piece 2 are connected through the driving foot 4 .

Embodiment 5: The difference between this embodiment and the piezoelectric micro-spray device based on the bending vibration sandwich transducer described in Embodiment 1 is that the conical inner cavity 3-1 is the same as the injection through hole 3-3. Shaft, this arrangement is conducive to liquid ejection.

Claims (5)

1. based on the piezoelectric micro-spray device of the bending vibration sandwich transducer, it comprises the bending vibration sandwich transducer (1), vibrating sheet (2) and nozzle (3); It is characterized in that: the bending vibration sandwich transducer ( 1) Including rear end cover (1-1), front end cover (1-2), two piezoelectric ceramic sheets (1-3) and four electrode sheets (1-4), the two piezoelectric ceramic sheets (1-3) are sequentially arranged between the rear end cover (1-1) and the front end cover (1-2), between the rear end cover (1-1) and a piezoelectric ceramic sheet (1-3) is arranged An electrode sheet (1-4), an electrode sheet (1-4) is arranged between the front cover (1-2) and another piezoelectric ceramic sheet (1-3); two piezoelectric ceramic sheets (1- 3) Two electrode sheets (1-4) are arranged between them, the two electrode sheets (1-4) are located on the same plane, and there is a gap between the two electrode sheets (1-4); The piezoelectric ceramic sheets (1-3) are all polarized along the thickness direction, and the polarization directions of the two piezoelectric ceramic sheets (1-3) are opposite; the nozzle (3) has a conical inner cavity (3-1) , the bottom of the conical inner cavity (3-1) has a spray through hole (3-3), and the side wall of the upper part of the conical inner cavity (3-1) has an inlet hole (3-2); the front end cover The bottom surface of the end of (1-2) is fixedly connected to the top surface of the vibrating piece (2), and the bottom surface of the vibrating piece (2) is fixed to the edge of the large opening end of the conical inner cavity (3-1) in the nozzle (3) Connect and completely cover the large open end of the conical cavity (3-1) in the nozzle (3). 2. The piezoelectric micro-injection device based on the bending vibration sandwich transducer according to claim 1, characterized in that the cross-section of the piezoelectric ceramic sheet (1-3) is square or circular. 3. The piezoelectric microspray device based on the bending vibration sandwich transducer according to claim 1, characterized in that the connection position between the front end cover (1-2) and the vibrating piece (2) is located at the center of the vibrating piece (2) . 4. The piezoelectric micro-spray device based on a bending vibration sandwich transducer according to claim 1, characterized in that the front end cover (1-2) is connected to the vibrating plate (2) through a driving foot (4). 5. The piezoelectric micro-injection device based on a bending vibration sandwich transducer according to claim 1, characterized in that the conical inner cavity (3-1) is coaxial with the injection through hole (3-3).