Magnetorheological Damper Damping Characteristics Experimental Magneto-Rheological Dampers Used in Ambulances The magneto-rheological dampers used in this paper are flow-and shear-mixed, approximately 250 mm long, 50 mm OD, and 20 mm piston rod diameter. , Travel 40mm, rated input voltage 24V, maximum static load 7kN. Magnetorheological Fluid Shock Absorber Experimental Setup Figure Damper damping performance The experiment was conducted on the shock absorber comprehensive performance test bed model HQZ-0402. The experimental process is: the piston and cylinder are fixed on the base, the piston rod and the pedestal are connected for simple harmonic vibration with an amplitude of 15mm. When no voltage signal is applied, the maximum speed v0 of the simple harmonic vibration is set to 0025m/s respectively. 006m/s, 01m/s, 015m/s, 0165m/s, 018m/s are tested, the relative displacement and damping force of the piston relative to the cylinder are measured and the data is recorded by the computer; 5V, 10V is applied to the damper in sequence. Repeat the above experiment with voltage signals of 15V and 20V. Damping force-displacement curve The force-displacement curve of the shock absorber is a damping force-displacement curve under experimental conditions where the maximum velocity v0 is 006 m/s and 015 m/s, and the voltages are 0, 5 V, and 10 V, respectively. It can be seen that the hysteresis curve of the shock absorber is very full, and the performance of vibration damping and energy consumption is good; the curve is smooth and smooth, indicating that the shock absorber works smoothly; under the condition that the set maximum speed is constant, with the increase of the voltage signal, As the area of ​​the curve increases, the ability of the shock absorber to consume energy increases significantly. On the other hand, with the increase of the set vibration speed, the vibration-reducing ability also increases significantly while keeping the applied voltage constant. Damping force-velocity relationship shock absorber force-velocity curve gives the relationship between piston speed and damping force under different voltage conditions. It can be seen from the figure that keeping the input voltage constant, as the piston movement speed increases, The damping force of the shock absorber also increases correspondingly; the piston movement speed is gradually reduced, and the damping force of the shock absorber is also reduced correspondingly, but does not coincide with the rising curve, so the relationship between the damping force of the magnetorheological damper and the vibration speed is not Linear, there is a clear hysteresis phenomenon. Relationship between applied voltage change and damping force Relationship between damping force and applied voltage change is the curve of shock absorber damping force and applied voltage when the maximum speed v0 is 006m/s and 015m/s respectively. As can be seen from the figure, the damping force increases as the voltage increases. When the signal voltage is small, the damping force of the damper is basically linear with the voltage, and when the voltage is large, the damping force increases less, and saturation occurs near a certain value. Conclusion The experimental results of magnetorheological damper show that under the same excitation speed, the area surrounded by the hysteresis curve of damper dynamometer gradually increases with the increase of signal voltage, in a vibration cycle. The energy consumed by the vibration system is also gradually increased; the damping force of the shock absorber can be continuously adjusted, and the key to the design is to make the ultrasonic generator, transducer, horn and tool form a resonant system, so that the tool can produce the maximum amplitude. Since the ultrasonic generator and transducer are generally designed and manufactured by a professional manufacturer, the design of the horn and the connection between the horn and the cutter are mainly considered. Regarding the design method of the horn, domestic and foreign scholars have done a lot of research. The ultrasonic generator and piezoelectric ceramic transducer used in this device are all produced by professional manufacturers. The ladder-shaped horn is used for design. Air Dry Device,Plastic Extruder Feeder,Plastic Loading Machine Deke Plastics Machinery Co., Ltd. , http://www.china-plastic-granulator.com