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The principle of electronic universal testing machine
 Time: 2018-08-27   Views:

In the mechanical testing of building materials and metal materials, it has been widely used due to its good control performance and test accuracy. In large steel companies and quality inspection unit laboratories, electro-hydraulic servo universal testing machines are often operated at high loads. Most of the testers lack maintenance experience, so these problems often occur. Manufacturers and users are bothered.


In fact, the electro-hydraulic servo universal testing machine is sophisticated but not expensive. As long as you have the following experience, you will be comfortable with it.


Hydraulic oil: The tank level must be checked frequently and replenished in time; generally, the oil should be changed every 2,000 to 4,000 hours; however, the most important thing is that the oil temperature must not exceed 70 °C, and the cooling system must be turned on when the oil temperature exceeds 60 °C;


Filter: For filters without a clogging indicator, it is usually replaced every 6 months. For filters with clogging indicators, they should be monitored continuously and must be replaced immediately after the indicator is alarmed;


Accumulator: Some electro-hydraulic servo universal testing machine is equipped with accumulator. The pressure of the accumulator must be in normal working condition. If the pressure is not enough, the pressure should be replenished immediately; only the accumulator should be filled with nitrogen;


Regular inspection of components: all pressure control valves, flow control valves, pump regulators, and signal devices such as pressure relays, travel switches, and thermal relays must be regularly inspected;


Cooler: The scale of the air-cooled cooler should be cleaned regularly; if it is water-cooled, it should be observed regularly whether the cooling copper pipe is broken or leaked;


The lead screw and transmission part of the electro-hydraulic servo universal testing machine should be regularly coated with lubricating oil to prevent dry friction;


The electro-hydraulic servo universal testing machine fasteners should be locked regularly: the vibration after the sample is broken often makes some fasteners loose, and it is necessary to conduct regular inspections to avoid large losses due to loose fasteners.


Other inspections: Improve vigilance and pay close attention to details, so that you can detect accidents early and prevent large accidents. This is especially true when the device is initially put into operation. Always pay attention to external leaks, contaminants, component damage, and abnormal noise from pumps, couplings, etc.


The electronic universal testing machine is powered by a motor. Through the FineTest II controller, the fixture is controlled to drive the sample to perform tensile, compression, bending, peeling, tearing and other tests. The test force, displacement, deformation, etc. are displayed on the computer screen or The LCD screen displays the material's tensile strength, compressive strength, peel strength, yield strength, elongation, etc., and can print out various reports.


The motor is divided into stepper motor, DC servo motor and AC servo motor. The relatively simple tensile tester can also use three-phase asynchronous motor. At present, the more used motors are: stepper motor and AC servo motor, its characteristics It is easy to control, low noise, large output torque, and even output constant torque.


When a pulse or signal is sent to the motor, the motor will rotate and change with the number of pulses, frequency, etc., and the feedback of the other components will be used to control the signal. The speed can be fast or slow.