CN107246911A - A kind of passive detection device of utilization piezoelectric structure - Google Patents

Abstract

The invention discloses a passive detection device using a piezoelectric structure, which is composed of a power supply, a detection device powered by the power supply, and a wireless transmission device for transmitting and transmitting detection signals, and is characterized in that it has at least one piezoelectric structure detection device. Unit: In the piezoelectric structure detection unit, the piezoelectric material 102 and the outer wrapping layer 101 are used as a piezoelectric component, and the detection chip integration 103 as a detection and signal wireless transmission device is covered on the wrapping layer 101 of the piezoelectric component. The invention can reduce vibration and noise in the original mechanism and at the same time play the role of energy supply, wherein the piezoelectric sheet converts the mechanical energy of vibration and extrusion into electric energy for output and power supply. The present invention can be applied in mechanical devices such as rail trains, automobiles and airplanes, and utilizes the vibration formed by the application mechanism to detect related characteristics.

Description

A passive detection device using piezoelectric structure

technical field

The invention relates to a passive detection device using a piezoelectric structure, in particular to a passive detection device that converts mechanical energy generated by vibration into electrical energy.

Background technique

Mechanical vibration energy is a form of energy that is ubiquitous in the environment. There are abundant vibration sources of continuous or periodic continuous vibration, such as vibration generated during the operation of household appliances and industrial production equipment, vibration generated during human movement and vehicle driving, Vibration of bridges, etc. Often this energy is wasted by neglect or absorbed by the shock absorber system. Therefore, the vibration energy in the environment is converted into electrical energy through the vibration energy harvester to supply power for low-power electronic devices, which not only improves the comprehensive utilization of energy, but also provides a new green power system for low-power electronic devices. The development and application of low-power electronic devices such as sensor networks and portable devices is of great significance.

At present, the principles used by generators that convert vibration energy into electrical energy mainly include electrostatic induction, electromagnetic induction, and electrostatic pulse generators. However, the electrostatic induction generator that has been invented needs to be connected to an external power supply as a starting voltage, and the electrostatic energy harvesting device produces high voltage, low current and high output impedance, which limits the application of electrostatic energy harvesting technology to a certain extent. application range. Electrostatic pulse generators have deficiencies in miniaturization and light weight, and the output power density is low, which cannot meet the needs of various vibration mechanical energy collection.

Contents of the invention

The invention relates to a passive detection device of a piezoelectric structure that can convert vibration energy in the form of rail locomotives, aviation aircraft, etc. into electric energy, and provides matching passive detection for low-power detection equipment such as acceleration and vibration frequency.

To achieve the above object, the specific device provided by the invention is:

A passive detection device using a piezoelectric structure, consisting of a power supply, a detection device powered by the power supply, and a wireless transmission device for transmitting detection signals to the outside, with at least one piezoelectric structure detection unit; the piezoelectric structure detection unit In the present invention, the piezoelectric material 102 and the outer wrapping layer 101 are used as a piezoelectric component, and the detection chip integration 103 as a detection and signal wireless transmission device is covered on the wrapping layer 101 of the piezoelectric component.

Further, in a structure with multiple piezoelectric components, the piezoelectric structure detection unit has more than one piezoelectric component, and the piezoelectric components are stacked and installed near the vibration source, and the electric energy output by each piezoelectric component is input to and A power management unit that manages and adjusts the output power of each piezoelectric component and provides power for the detection and signal wireless transmission device after adjustment; the power management unit can also be integrated into the piezoelectric structure detection unit that has a For the piezoelectric components above, the piezoelectric components are stacked and installed near the vibration source, and the electric energy output by each piezoelectric component is input to the power management unit that manages and adjusts the output power of each piezoelectric component and is adjusted for the detection and signal wireless transmission device to provide power; the power management unit can also be integrated in the detection chip integration 103 .

In this way, the piezoelectric material 102 vibrates and supplies power to the detection chip integration 103 .

The piezoelectric material 102 is selected from piezoelectric composite materials composed of vinylidene fluoride (PVDF), zinc oxide (ZnO), PZT piezoelectric ceramics, PbTiO3 piezoelectric ceramics, inorganic piezoelectric ceramics, and organic polymer resins. According to different structural designs and different parameter conditions, one or several piezoelectric materials or piezoelectric composite materials are selected, and controllable preparation is carried out by hydrothermal method, sol-gel method, pulse deposition method, electrospinning and other processes. .

The shape and performance of the piezoelectric material 102 can be regulated by controlling the relevant parameters in the preparation process, so as to obtain the optimal piezoelectric material suitable for specific conditions.

The main function of the integration 103 of the power management module device is to rectify and filter the alternating electric signal generated by the piezoelectric material with deformation through the rectifier bridge and output the DC-DC conversion circuit (DC-DC), which can be the back-end capacitor or The direct current that powers electrical equipment. The selected rectifier bridge can not only be built directly using diodes (1N4146), but also can use a commercially integrated full-bridge chip (DB107), or even directly use a commercial chip (LTC3588) with a low-voltage lock function for power management. .

Under the action of external vibration, when the piezoelectric material is deformed by an external force in a certain direction, a polarization phenomenon will occur inside it, and at the same time, positive and negative polarities will appear on its two opposite surfaces. The charge has a pulse electrical signal output, which is supplied to the detection device through the power management module and causes the magnetic flux passing through the coil to change, so there is a pulse electrical signal output, and the pulse signal is powered to the detection device and the wireless transmitter through the power management module.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention provides a piezoelectric material structure as a power supply. Compared with an external power supply, the design and processing are time-consuming and cumbersome, and the performance of the device is unstable. The present invention has stronger practicability, greatly reduces the cost and can still maintain a very beneficial detection signal Output.

2. The passive wireless detection structural unit with a rectangular shape provided by the present invention can effectively reduce the noise of the device to be detected, and at the same time effectively convert vibration mechanical energy into electrical energy.

3. Piezoelectric materials with certain mechanical strength and elasticity are used as the supporting core, and plastic or special rubber is used as the matrix, so the cost is low.

4. The present invention has simple structure, simple preparation method, no special requirements on materials, can convert vibration energy generated by nature, orbits, etc. into electric energy, and has wide practical applications.

Description of drawings

The above and other objects, features and advantages of the present invention will be more clearly illustrated by the accompanying drawings. Like reference numerals designate like parts throughout the drawings. The drawings are not intentionally scaled according to the actual size, and the emphasis is on illustrating the gist of the present invention.

Fig. 1 is the structural representation of passive detection device of the present invention;

Fig. 2, Fig. 3 and Fig. 4 are structural model diagrams of the generator embodiment 2 of the present invention;

Fig. 5 is a structural model diagram of the third embodiment of the generator of the present invention;

Fig. 6 is a multi-layer plus example diagram of the present invention;

Fig. 7 is a circuit diagram of the supporting power management of the present invention.

detailed description

Mechanical vibration energy is a form of energy that is ubiquitous in the environment. There are abundant sources of continuous or periodic continuous vibration, such as the vibration generated by household appliances and industrial production equipment. Often this energy is wasted by neglect or absorbed by the shock absorber system. Therefore, the vibration energy in the environment is converted into electrical energy through the vibration energy harvester to supply power for low-power electronic devices, which not only improves the comprehensive utilization of energy, but also provides a new green power system for low-power electronic devices. The development and application of sensors and passive detection are of great significance.

The specific implementation of the passive detection device of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments. Embodiment one:

Referring to Fig. 1, in any passive detection device structure, including: piezoelectric material 102, wrapping material 101, detection device, wireless transmission and power management module device integration 103; through piezoelectric material 102 vibration power supply to detection device and wireless The integration 103 of the transmitting device transmits the detection data to the wireless receiving device.

The wrapping material 101 is selected to have a certain mechanical strength, and when the detection device is subjected to an external force (vibration), the piezoelectric material 102 vibrates up and down, thus outputting a pulse electrical signal.

In the passive detection device of the present invention, the piezoelectric material 102 is selected from vinylidene fluoride (PVDF), zinc oxide, PZT piezoelectric ceramics, PbTiO ₃ series piezoelectric ceramics, inorganic piezoelectric ceramics and organic polymer resins. piezoelectric composite materials. In the passive detection device of the present invention, 102 piezoelectric material is the power generation part, and 103 is the integrated part of power management, detection device and wireless transmission device.

The generator of the present invention has a simple structure, a simple preparation method, and no special requirements for materials. In actual use, only simple fixing and packaging are required, and it can be used in the living environment to collect electricity generated by nature, rails, mechanical equipment, etc. Vibration mechanical energy has a wide range of practical uses.

Embodiment two:

The structure of the piezoelectric structure passive detection device in this embodiment will be described in detail below with reference to FIG. 2 , FIG. 3 and FIG. 4 .

Referring to FIG. 2 , the piezoelectric material in the piezoelectric material power generation device has a left-right symmetrical two-part structure. Referring to FIG. 3 , a cross-arm beam 201 is arranged in the middle of the piezoelectric material to increase the vibration amplitude of the piezoelectric material, which will significantly increase the output electric energy. Referring to Figure 4, on the upper side of the piezoelectric structure are power management, detection devices and wireless transmission devices, this structure effectively reduces the overall size and structure, and maximizes the integration of passive detection devices, making the applicability of the present invention Stronger and has broad application prospects.

Embodiment three:

The implementation is applied to a wheel set of a rail vehicle. As shown in FIG. 5 , a plurality of said piezoelectric assemblies are adjacently installed near the vibration source. A plurality of piezoelectric components are attached to the vibration source, and their electric energy is collected into a detection chip integration 103 integrated with a power management unit (the detection chip integration 103 is also coated on the wrapping layer 101 of a certain piezoelectric component).

Embodiment four:

Referring now to FIG. 6 , in this embodiment, the multilayer piezoelectric structure is stacked, wherein the number of stacked layers is n>1, and the number of stacked layers in FIG. 6 is n=10. This multi-level piezoelectric structure passive detection device can not only provide a relatively large power output, but also play a noise reduction function through multi-level superposition. In Fig. 6, this implementation is applied to the wheelset of a rail locomotive, so that the present invention uses a passive detection device with a piezoelectric structure to detect the vibration of the train wheelset and reduce the noise during locomotive operation.

The following describes the power management circuit in detail in combination with FIG. 7 . The present invention has designed a power management circuit (Fig. 7) for high-efficiency double synchronous switch acquisition, and in this circuit, the transducers utilizing piezoelectric materials are respectively equivalent to the parallel reconnection of a current source (I1) and a capacitor (C1). The mode in series with the inductor (L1) and the mode in series with the voltage source (V1), the resistor (R1) and the inductor (L2) are respectively connected to the subsequent full-bridge rectifier circuit (D1, D2) through switches (J1, J2), Charge the primary energy storage capacitor (Cint) through diodes (D3, D4) respectively. After reaching a certain threshold, control the switch (J3) to charge the subsequent energy storage circuit including inductor (L3), diode (D5), capacitor (Cstorage), And simulate the load electrical appliances through Rload. Then, the flexible FPC circuit packaging with combination of soft and hard is adopted, and the power management circuit is integrated in the generator designed by the invention, so as to obtain the management circuit with the best power management efficiency.

In this embodiment, on the basis of the second embodiment, the passive detection device is applied to the rail locomotive. Referring to FIG. 5 , the passive detection device is applied to the wheel set vibration detection of the rail locomotive. The wheel set vibration can be used for passive detection, and the noise can be reduced.

The passive detection device of each embodiment of the present invention can be used in the vibrating mechanical structure in the mechanical device, such as the vibrating structure in the aircraft, to detect relevant data and improve its safety. In terms of safety and applicability, the present invention has wide application prospects.

During the research process of the inventors, it was found that different piezoelectric materials have a great influence on the actual output power in the selection of piezoelectric materials in various embodiments of the present invention in actual work. As the piezoelectric performance of the piezoelectric material increases, the electrical signal at both ends of the load increases, and the piezoelectric material selected has lower piezoelectric performance and the output electrical signal is weaker. Therefore, the selection of the piezoelectric material in the present invention depends on the working power of the detection equipment. It should be noted that the "output power" used in this article refers to the product of the maximum value of the pulse current and the maximum value of the pulse voltage formed at both ends of the load, that is, the instantaneous maximum power.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can use the methods and technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent of equivalent change Example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the technical solution of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims (7)

1. a kind of passive detection device of utilization piezoelectric structure, by power supply, the detection means being powered and signal will be detected Outwards the radio transmitting device of transmitting transmission is constituted, it is characterised in that with least one piezoelectric structure detection unit；In piezoelectricity In structure detection unit, the integument (101) of piezoelectric (102) and outer layer as piezoelectric element, as detection and signal without The detection chip integrated (103) of line transmitting device is posted on the integument (101) of piezoelectric element.

2. the passive detection device of utilization piezoelectric structure according to claim 1, it is characterised in that the piezoelectric structure inspection Surveying unit has more than one piezoelectric element, and piezoelectric element is installed near vibration source, and the electric energy of each piezoelectric element output is defeated Enter to each piezoelectric element output electric energy be managed the PMU of adjustment and through its adjustment after be it is described detection and Signal wireless transmission device provides electric energy；The PMU can be also integrated in detection chip integrated (103).

3. the passive detection device of utilization piezoelectric structure according to claim 1, it is characterised in that the piezoelectric element exists It is adjacent near vibration source to install.

4. the passive detection device of utilization piezoelectric structure according to claim 1, it is characterised in that the piezoelectric element exists Vibration source nearby install by lamination.

5. the passive detection device of utilization piezoelectric structure according to claim 1, it is characterised in that the piezoelectric choosing From vinylidene PVDF, zinc oxide, PZT piezoelectric ceramics, PbTiO3 series piezoelectric ceramics, inorganic piezoelectric ceramics, organic polymer tree One of piezo-electricity composite material that fat is constituted.

6. the passive detection device of utilization piezoelectric structure according to claim 1, it is characterised in that the power management list Member, detection means and wireless base station apparatus become one.

7. the passive detection device of utilization piezoelectric structure according to claim 1, it is characterised in that the piezoelectric Centre sets a beam arm (201).