Ultrasonic Piezoelectric Ceramics
When you light a gas stove or water heater, a piezoelectric ceramic has quietly served you once. The manufacturer hides a piece of piezoelectric ceramic in this type of piezoelectric ignition device. When the user presses the spring of the ignition device, the transmission device applies pressure to the piezoelectric ceramic, causing it to generate a high voltage, which in turn generates a high voltage. The electrical energy is directed to the outlet of the gas for discharge, so the gas is ignited by an electric spark. This function of piezoelectric ceramics is called the piezoelectric effect. Conversely, when a voltage is applied, mechanical stress is generated, which is called the inverse piezoelectric effect.
When the brake pads touch the rotor at low speeds, the brake pads vibrate, sometimes manifesting as a screeching noise. This noise doesn't affect the performance of the brakes, but it can lead to unnecessary pad replacements and the addition of shims, dampening materials, and other components to eliminate noise. If a simple piezoelectric ceramic actuator is installed in the brake piston of the car, the "jitter" frequency is applied to the support plate of the internal brake block, which effectively suppresses the vibration that produces sharp noise, so that it can be used under the conditions of temperature and humidity changes and braking. function under normal wear and tear of the system. Since no detectors or logic systems are required to determine the appropriate control frequency, the device is much simpler in construction and requires fewer components.
Piezoelectric ceramics can also be used as piezoelectric ceramic knock sensors, ultrasonic sensors, acceleration sensors and other categories of automobiles. Piezoelectric ceramic knock sensor is composed of piezoelectric ceramic vibrator, metal sheet, sealing gasket, metal shell and so on. The electric charge generated by the piezoelectric vibrator is proportional to the vibration of the engine cylinder. The generated voltage enters the electronic control unit through the shielded wire, and the voltage generated by the vibration around 7kHz is detected. The electronic control unit judges the explosion according to the magnitude of this voltage. Shock intensity, timely correction or delaying the ignition in response to eliminate the knocking in advance, so that the engine works at the ignition time close to the knocking, the highest thermal efficiency, and the least fuel consumption, so as to realize the working state without knocking, and ensure that the engine can achieve the maximum possible power and economic indicators. The operating ultrasonic sensor is used as a car reversing anti-collision alarm device, also known as an ultrasonic reversing radar or a reversing sonar system, especially suitable for large vehicles such as long-loading vehicles, heavy-duty trucks, and mining vehicles. Ultrasonic sensors are usually composed of aluminum alloy shells, piezoelectric ceramic transducers, sound-absorbing materials, and lead electrodes. They have wide horizontal characteristics and limited directivity in the vertical direction. In principle, lead zirconate titanate PZT piezoelectric ceramics are used. The positive and inverse piezoelectric effect of mutual conversion between electrical energy and mechanical energy, when an electrical signal is added to the piezoelectric ceramic, produces mechanical vibration and emits ultrasonic waves. When it is made of ceramics, there will be an electrical signal output, and through the data processing time difference distance measurement, the distance between the car and the obstacle and the alarm when it is dangerously collided can be calculated and displayed. , the practicality is quite strong. In order to obtain high transmitting efficiency and receiving sensitivity, the ultrasonic sensor with integrated transmitting and receiving is the mainstream product on the market, with high transmitting efficiency, receiving sensitivity and sharp directivity. Ultrasound has a certain detection angle and range, which can cover the entire area of the rear of the car. Ultrasonic sensors for directly measuring the distance between the vehicle chassis and the road surface are being developed for the electronically controlled suspension system of automobiles. Ultrasonic sensors are also used in air flow meters to detect the amount of engine intake air.
Contact Person: Ms. Hogo Lv