32 results about "Piezoelectric coupling" patented technology

The invention discloses a ray pectoral fin-imitated piezoelectric coupling propulsive mechanism. The ray pectoral fin-imitated piezoelectric coupling propulsive mechanism comprises a crankshaft, guide rods, a swinging block, a piezoelectric compound fin, a fish body pedestal, a crankshaft support, a driving motor, a battery pack and a main control panel, wherein the crankshaft is arranged on the crankshaft support; the swinging block comprises a pin shaft and a swinging block support; the pin shaft is arranged on the swinging block support; the crankshaft support and the swinging block support are fixedly arranged on the fish body pedestal; one of the guide rods is arranged between one end of the swinging block and the crankshaft; the driving motor and the crankshaft are connected through a gear; the piezoelectric compound fin is arranged at the other end of the swinging block; the battery pack can provide a direct current power source; the main control panel is electrically connected with the piezoelectric compound fin; the crankshaft is a four-turn crankshaft; the guide rod is arranged on each turning shaft of the four-turn crankshaft. The ray pectoral fin-imitated piezoelectric coupling propulsive mechanism can reduce the structural size, the weight of the fish body, and can realize chordwise fluctuation propulsion.

The invention provides an accurate controllable non-contact test piece rotary magnetic field fatigue excitation and vibration test device. The device comprises a vibration damping insulation clamp, a vibration damper, a dynamic balance device, a vibration exciter, an electromagnetic piezoelectric coupling vibration sensor, a test station, a transmission device and an accurate control device. The excitation and vibration test device is suitable for rotary test pieces and especially suitable for vibration characteristic researches on a wind power blade, an engine, a turbine blade, a helicopter rotor and a tail rotor blade, the excitation and vibration test device can vividly simulate vibration fatigue states of rotary test pieces respectively under conditions of 360-DEG all directions, same rotating speed and different excitation forces, same excitation force and different rotating speeds, and different rotating speeds and different excitation forces, the excitation and vibration test device can monitor related vibration characteristic parameters such as the excitation force, the vibration displacement, the vibration speed and the vibration acceleration continuously, and the excitation and vibration test device is suitable for vibration fatigue characteristic analysis on stationary test pieces.

The invention discloses a piezoelectric coupler and a power circuit thereof. The piezoelectric coupler and the power circuit thereof are mainly used in the occasion that input and output need to be isolated in a micropower switch power supply or in a low-power switch power supply. The piezoelectric coupler comprises two resonant branches used for piezoelectric coupling; each resonant branch is composed of piezoelectric harmonic oscillators; by applying the power circuit of the piezoelectric coupler, an electric signal of a primary-side topology is in direct resonant coupling with an auxiliary-side topology through a first resonant branch of the piezoelectric coupler; and a loop is formed through the other resonant branch of the piezoelectric coupler after loading. The piezoelectric coupler and the power circuit provided by the invention can be used for solving the problems that the process is complex and the manpower cost is high when the former switch power supply is isolated by adopting an electromagnetic transformer, and the problems of low temperature stability, low transformation rate and electro-magnetic interference (EMI) when an inductance and a capacitance as discrete components are connected on the circuit in a capacitance isolated scheme.

The invention discloses a method for preparing textured lead zirconate titanate ceramic, namely a method for preparing highly textured PZT piezoelectric ceramic with a (001) direction. The method for preparing the textured lead zirconate titanate ceramic comprises the following steps of: preparing a strontium titanate template with a laminated microstructure from strontium carbonate and titanium dioxide serving as raw materials by using a two-step molten salt method; adding the template into PZT powder, casting, tabletting and sintering to prepare a PZT block material with higher texturing, piezoelectric coefficient and electromechanical coupling coefficient; and adding the strontium titanate template in microscopic directed arrangement into the PZT ceramic, making the template have directivity in the PZT ceramic by using a casting method, and making the PZT ceramic grow directionally along the template direction to have a highly textured structure similar to a single-crystal structure. The piezoelectric ceramic has higher orientation degree, and has the piezoelectric property greatly improved in the aspects such as piezoelectric constant, piezoelectric coupling coefficient and the like compared with the common PZT.

The invention provides a duplexer. The duplexer comprises a transmitting filter, wherein the transmitting filter is connected between a transmitting end and an antenna end and comprises a series resonator and a parallel resonator connected in a trapezoidal form; and a receiving filter, wherein the receiving filter is connected between a receiving end and the antenna end and comprises a series resonator and a parallel resonator connected in a trapezoidal form, wherein an LWR resonator is connected to a series branch of the TX (transmitting end) or the RX (receiving end), or the LWR resonator isconnected to a parallel branch of the TX or the RX and is connected with a grounding end. According to the duplexer provided by the invention, the LWR resonator is introduced into the structural design of the filter and the duplexer, and is applied to the structure of a piezoelectric filter and the duplexer to improve the performance of the piezoelectric filter and the duplexer; the characteristics of the impedance characteristic, the flexible frequency and piezoelectric coupling coefficient adjustment of an LWR resonant frequency point are utilized, a combination of different frequencies andpiezoelectric coupling coefficients is adopted, and required impedance conversion is realized at a specific frequency point.

The invention aims to provide an SAW (surface acoustic wave) gyroscope based on a standing wave mode. According to the SAW gyroscope based on the standing wave mode, a 128-degree Y-X cut LiNbO3 piezoelectric substrate with the high piezoelectric coupling coefficient, high SAW propagation speed and large acoustic-optical coupling coefficient is adopted; a metal dot matrix made of gold and an SAW receiving end in an acousto-optic reading mode are placed between resonant cavities of a dual-port resonator triggered by a receiving and transmitting antenna, so that a novel gyroscope in a standing wave mode is realized. Due to the design of the receiving and transmitting antenna, electronic circuit modules required by the SAW gyroscope can be effectively reduced, that is, the use of external circuits is reduced; and the SAW receiving end adopts a high-precision acousto-optic coupling mode to read out the change of the angular rate, so that the accuracy and the sensitivity of the SAW gyroscopeare improved.

The invention discloses an SAW-BAW hybrid resonator. The SAW-BAW hybrid resonator comprises a first electrode layer, a first piezoelectric film layer, a second piezoelectric film layer, a second electrode layer and a substrate layer which are arranged in sequence, the orthographic projection of the first electrode layer and the orthographic projection of the first piezoelectric film layer on the substrate layer coincide, and the orthographic projection of the second piezoelectric film layer and the orthographic projection of the second electrode layer on the substrate layer coincide; the whole body formed by the first electrode layer and the first piezoelectric film layer is periodically arranged on the second piezoelectric film layer at equal intervals; the piezoelectric coupling constant of the second piezoelectric thin film layer is lower than that of the first piezoelectric thin film layer, and the acoustic impedance of the second piezoelectric thin film layer is higher than that of the first piezoelectric thin film layer. The SAW-BAW hybrid resonator provided by the invention can have the excellent characteristics of high frequency, high K2, high Q value and the like by utilizing a Sixhu wave mode; not only can clutter response caused by Rayleigh waves and bulk waves be effectively suppressed, but also the structure is simple, the manufacturing difficulty and the production cost of the device are reduced, and the device has great application prospects.

The present invention provides a duplexer comprising: a transmit filter connected between a transmit terminal and an antenna terminal and comprising a series resonator and a parallel resonator connected in a trapezoidal manner; The receiving filter is connected between the receiving end and the antenna end, the transmitting end, the receiving end and the antenna end or the transmitting end and thereceiving end respectively lead out a branch to the grounding end, and the LWR resonator and the passive device are connected in the branch in series; According to the invention, the LWR resonator isintroduced into the structural design of the filter and the duplexer and is applied to the piezoelectric filter; The structure of the diplexer is used for improving the performance of a piezoelectricfilter and the performance of the diplexer, and required impedance conversion is realized at a specific frequency point by utilizing the impedance characteristic of an LWR resonant frequency point, the characteristic of flexible frequency and the characteristic of piezoelectric coupling coefficient adjustment and adopting the combination of different frequencies and piezoelectric coupling coefficients.

A method for extracting parameters of a piezoelectric multi-wafer equivalent circuit model includes such steps as fixing one end of a piezoelectric multi-wafer on a vibration source, making the otherend free, keeping constant sinusoidal vibration acceleration amplitude a, and obtaining the relation curve between output voltage and vibration frequency of the piezoelectric multi-wafer under different load resistances RL through frequency sweeping. The short-circuit resonance frequency fsc, open-circuit resonance frequency foc, static capacitance Cmc, mechanical quality factor Qoc, maximum powervalue Popt and short-circuit resonance voltage VML (omega sc) are determined. The equivalent inductance Lm, the equivalent capacitance Cm, the equivalent resistance Rm, the equivalent input stress VF, the piezoelectric coupling coefficient A and the static capacitance Cmc are obtained. The invention can accurately describe the relationship between the output voltage characteristic of the piezoelectric multi-wafer and the load, the ambient vibration frequency and the acceleration, and the electric measuring instrument required for the measurement is low in cost.

The invention discloses a viscosity detection sensor based on double piezoelectric coupling and belongs to the technical field of viscosity detection. The viscosity detection sensor is characterized in that a piezoelectric quartz crystal is fastened in a clamping position in a supporting seat; a mechanical vibration conducting column is cemented between an output unit and a feedback unit; the output unit and the feedback unit are arranged in an insulation clamping position on the supporting seat on which the piezoelectric quartz crystal is fastened; fixing holes for a screw to penetrate through are formed in a mounting supporting and positioning gland and a mounting supporting and positioning base; the mounting supporting and positioning base is provided with a clamping position for mounting an elastic member; the elastic member is pressed into the mounting supporting and positioning base by the mounting supporting and positioning gland; the mounting supporting and positioning gland is fastened with the mounting supporting and positioning base. The viscosity detection sensor has the beneficial effects that a piezoelectric quartz crystal fastener is reasonably distributed, so that directional flowing of air is facilitated and the influence of air current on inspection is reduced; in addition, the piezoelectric quartz crystal fastener has insulating and electromagnetic shielding functions, and the influence of objective factors on a test result is eliminated. According to the viscosity detection sensor disclosed by the invention, a circular elastic member is designed, so that the aseismic function of the system is enhanced, mechanical vibration is reduced to the maximum extent, and the influence of outside on the test result is reduced.

The invention belongs to the technical field of non-destructive detection technology and measurement, and particularly relates to a non-immersive liquid-level measurement sensor based on ultrasonic guided wave and its installation and application method. The working principle of PWAS (a thin piezoelectric wafer active sensors) is based on the piezoelectric effect and the inverse piezoelectric effect. The size of PWAS in the plane x1x2 direction is much larger than its size in the plane x1x3 direction, by means of piezoelectric coupling d31, coupling of mechanical parameters and electrical parameters can be achieved in order to achieve the effective excitation and reception of ultrasonic guided waves. The coupling of PWAS and the plate is the in-plane coupling at the edge of the PWAS. When the PWAS sticks to the surface of the thin-walled plate, the adhesive layer is extremely thin. Through the coupling of the in-plane motion, the PWAS edge can be effectively stimulated or receive the Lamb waves.

A method for extracting equivalent circuit parameters of piezoelectric vibration energy collecting device includes such steps as extracting equivalent circuit parameter of piezoelectric vibration energy collect device, extracting equivalent circuit parameters of piezoelectric vibration energy collecting device, extracting equivalent circuit parameters of piezoelectric vibration energy collecting device, one end of the piezoelectric vibration energy collecting device is fixed on the vibration source, the other end is free, the constant sinusoidal vibration acceleration amplitude a is kept, andthe relationship curve between the output voltage and the vibration frequency of the piezoelectric vibration energy collecting device under different load resistances RL is obtained by sweeping frequency; The short-circuit resonant frequency fsc, open-circuit resonant frequency foc, static capacitance Cmc, mechanical quality factor Qoc, mechanical quality factor QML, maximum power value Popt, open-circuit resonant voltage Voc ([omega] oc) are determined. The equivalent inductance Lm, the equivalent capacitance Cm, the equivalent resistance Rm, the equivalent input stress VF, the piezoelectriccoupling coefficient A and the static capacitance Cmc are calculated. Themethod can accurately describe the relationship between the output voltage characteristic of the piezoelectric vibration energycollecting device and the load, the ambient vibration frequency and the acceleration, and the cost of the electric measuring instrument required for measuring is low.

The invention discloses a multi-section bent beam piezoelectric generator and a wave power generation ship. The piezoelectric generator comprises left and right fixed substrates arranged horizontallyopposite to each other. A plurality of piezoelectric elements are arranged in a linear array between the left and right fixed substrates. Each piezoelectric element comprises an energy obtaining component and an excitation component, wherein the energy obtaining component comprises piezoelectric coupling beams with one end fixedly connected with the left and right fixed substrates respectively, and the piezoelectric coupling beams are arranged in a tortuous manner, and a piezoelectric patch is adhered to the vertical beam surface of each piezoelectric coupling beam; and the excitation component includes an excitation ball arranged between the left and right piezoelectric coupling beams opposite to each other, and two ends of the excitation ball are fixed to or hinged with the left and right piezoelectric coupling beams respectively through a connecting member. The excitation ball drives connecting ends of the left and right piezoelectric coupling beams to vibrate up and down relative to fixed ends of the piezoelectric coupling beams to cause deformation of vertical beams of the piezoelectric coupling beams, and then the piezoelectric patches on the vertical beams are driven to be synchronously deformed to generate electric currents.

The invention discloses a metal thin strip three-dimensional forming system based on piezoelectric coupling control. Comprising a Joule thermal power source, an angle-adjustable printing mechanism mounting device, a hammering type printing mechanism, a rolling type printing mechanism, pressure sensors, a substrate, a control system and a metal thin strip conveying mechanism, wherein the hammering type printing mechanism and the rolling type printing mechanism are mounted on the angle-adjustable printing mechanism mounting device in an array mode, and the pressure sensors are mounted on the hammering type printing mechanism and the rolling type printing mechanism. A first pole of the Joule thermal power supply is electrically connected with the hammering type printing mechanism and the rolling type printing mechanism, a second pole of the Joule thermal power supply is electrically connected with the substrate, and the Joule thermal power supply and the pressure sensor are both connected with the control system; the pressure sensor is used for collecting the contact pressure between the hammering type printing mechanism and the metal thin strip on the base plate and between the rolling type printing mechanism and the metal thin strip on the base plate; and the control system is used for controlling the Joule thermal power supply to output Joule thermal energy according to the magnitude relationship between the contact pressure and a preset trigger pressure threshold value. The printing efficiency of the system is improved, and the requirements for different printing modes are met.

The invention relates to a design method of stress compensation film for AT-cut temperature compensated crystal oscillator, which is characterized in that: at least three steps are included: an ANSYSthree-dimensional solid simulation model of AT-cut temperature compensating crystal resonator is constructed according to piezoelectric coupling finite element equation and dynamic equation; The crystal stress distribution cloud map corresponding to two different coating schemes is obtained by ANSYS simulation, The greater the stress applied to the x-axis direction of the crystal wafer under the same temperature, the more obvious the compensation effect of the temperature-frequency characteristic curve is obtained, and the optimal coating compensation is obtained. The invention provides design method of stress compensation film for AT-cut temperature compensated crystal oscillator which can avoid the error caused by adjusting the shape and position of the compensation film according to the artificial experience, can solve the actual processing cost, has strong operability, and is suitable for the design and development of the high stability temperature-compensated crystal oscillator.

An equivalent circuit model parameter extracting method for a piezoelectric bimorph includes such steps as fixing one end of piezoelectric bimorph on vibration source, freeing that other end, keepingconstant sinusoidal vibration acceleration amplitude a, sweeping frequency to obtain relationship curve between output voltage of piezoelectric generator and vibration frequency under different load resistances RL, and extracting parameters of equivalent circuit model of piezoelectric bimorph. The short-circuit resonant frequency fsc, open-circuit resonant frequency foc, static capacitance Cmc, mechanical quality factor Qoc, mechanical quality factor QML, maximum power value Popt, short-circuit resonant voltage VML (Omega sc) are determined. The equivalent inductance Lm, the equivalent capacitance Cm, the equivalent resistance Rm, the equivalent input stress VF, the piezoelectric coupling coefficient A and the static capacitance Cmc are obtained. The invention can accurately describe the relationship between the output voltage characteristic of the piezoelectric bimorph and the load, the ambient vibration frequency and the acceleration, and the electric measuring instrument required for measuring is low in cost.

The invention discloses a method and apparatus for detection of a broken piezoelectric material of an ultrasonic transducer. A broken piezoelectric material in an ultrasonic transducer of an ultrasonic stack of an ultrasonic device is detected by measuring a test piezoelectric coupling constant with a test scan of the ultrasonic stack. The test piezoelectric coupling constant is compared to a previously measured baseline piezoelectric coupling constant. The piezoelectric material is determined to be broken when the test piezoelectric coupling constant is less than the baseline piezo coupling constant by more than a predetermined amount.

The invention discloses a multifunctional piezoelectric power-generating shoe, and belongs to the technical field of piezoelectric power-generating shoes. The problem of lower power generation efficiency of an existing piezoelectric power-generating shoe is solved. The multifunctional piezoelectric power-generating shoe comprises a foot fixing device, a sole plate, a force transmission part, a circuit board and a sole shell, wherein the foot fixing device comprises a sole plate connecting hole; the foot fixing device is connected with the sole plate through the sole plate connecting hole; a circular arc section elastic plate end part notch of a force transmission part and a fixed plate notch of a piezoelectric part are formed in the sole plate; the force transmission part comprises a circular arc section elastic plate and a force transmission inclined plate; one end of the circular arc section elastic plate is fixed to a sole plate notch while the other end of the circular arc sectionelastic plate is fixed with one end of the force transmission inclined plate; the other end of the force transmission inclined plate is hinged to the free end of a force applying plate of the piezoelectric part; a fixed plate of the piezoelectric part is fixed to the sole plate notch; the piezoelectric part comprises the force applying plate, a piezoelectric coupling plate and the fixed plate; andpiezoelectric plates are arranged on the upper surface and the lower surface of the piezoelectric coupling plate. According to the multifunctional piezoelectric power-generating shoe disclosed by theinvention, the power generation efficiency of the piezoelectric power-generating shoe is improved.