The application of ultrasound in the field of micro-control
In recent years, nearly a thousand kinds of application devices have been developed abroad, and more than 100 US patents have been approved.
(1) Application in the detection field
Research and use the magnetostrictive positive or inverse effect of giant magnetostrictive materials to make various components that detect magnetic field, strain, displacement, torque, pressure, and current. According to the principle that rare earth giant magnetostrictive materials produce strain in a magnetic field, they can be combined with laser diodes or PZT materials to make various magnetometers. In 1991, RChung of the University of Iowa developed a giant magnetostriction. Prototype of laser diode magnetometer. The U.S. Navy has developed a magnetostrictive strain gauge using giant magnetostrictive materials, which is comparable to traditional semiconductor strain gauges.
It has a larger dynamic range, higher sensitivity and accuracy, and its temperature dependence is small, the measurable frequency band is wider, and the measurable strain is smaller. Japan's Toshiba company MSahashi and others invented a contact torque sensor made of magnetostrictive film, which has a large dynamic range, fast response, and sensitivity 10 times higher than a torsional strain gauge made of a traditional metal resistance film.
(2) Application in magnetic (electric)-mechanical transducer
The magnetic (electric) mechanical transducer based on giant magnetostrictive material has the advantages of large displacement, strong force, fast response, high reliability, small drift, low driving voltage, etc., so it is used in ultra-precision machining, micro-motor, vibration control, etc. And fluid machinery and other engineering fields have shown good application prospects, and it is a new type of intelligent drive component with great potential.
(3) Application in ultra-precision machining. Ultra-precision positioning systems with precisions of nanometers and above mostly use actuator elements based on piezoelectric ceramic materials, which have low output power, and effective measures must be taken to prevent breakdown and short-circuit problems caused by impact force and high driving voltage. The output displacement of the giant magnetostrictive drive element is dozens of times that of the electrostrictive actuator, and it can operate at low impedance. Hiroshi Eda of Ibaraki University in Japan and Kobayashi of Toshiba Corporation have designed a giant magnetostrictive actuator with a positioning accuracy of nanometers and successfully applied it to the micro-feeding device of a large optical diamond lathe.
(4) Application in micro motors. The materials that can be used for micro-motor drive components mainly include electro-rheological materials, shape memory alloys, piezoelectric ceramics, and giant magnetostrictive materials. Among them, those based on giant magnetostrictive materials
The performance of the micro motor is superior and the application prospect is very wide. Cedrat Recher che developed and tested a giant magnetostrictive friction motor for the first time. The stator of the motor is composed of a ring and two giant magnetostrictive linear actuators. It produces two vibration modes: translation and buckling, and uses a 90° phase shift. Coupling to generate elliptical vibration, using this elliptical vibration and using friction to transmit motion to the two rotors. Germany L. Kiesew et ter used Terfenol
D rod successfully developed an inchworm motor. When the coil is energized and its position changes, the giant magnetostrictive rods alternately expand and contract, thus creeping forward like a worm. The United States J M V Ranish and others developed a rotary stepping motor using giant magnetostrictive materials and the principle of peristalsis.
(5) Application in the field of vibration control. The active vibration reduction and noise reduction mechanism uses sensors to detect the vibration displacement signal of the vibration reduction object, and outputs a corresponding control signal to the actuator after processing by the controller. The actuator produces equal and opposite displacements to counteract the vibration. Using giant magnetostrictive actuator as actuator
The active vibration and noise reduction system of the structure has the characteristics of good low-frequency characteristics, the maximum vibration attenuation can reach 70%, and the frequency range is 0-5kHz. Japan's Oh mate K. used Terfenol-D to design a three-link arm type semi-active vibration control device, which can reduce vibration caused by earthquakes and strong winds. The device can generate controllable friction and friction torque in three straight or rotating directions. The United States MA nja nappa, etc. will giant magnetostrictive actuator
It is applied to the active control of vibration, and its working principle is analyzed theoretically and experimentally. For the first time, the basic mathematical model of the giant magnetostrictive actuator considering the thermal effect is given.
(6) Application in fluid machinery. At present, giant magnetostrictive electrical (magnetic)-mechanical energy converters are widely used in various valves, fuel injection systems, and micro pumps. A Swedish company used Terfenol-D to drive fuel injection valves and applied for a patent. Japan made a miniature diaphragm pump with Terfenol-D; ABB in Sweden designed a fluid pump with Terfenol-D as the driving element.
