The porosity bubble of the die-cast rotor is a common cause of poor cast aluminum rotor, and its test method is also the most concern by motor manufacturers.
If you want to understand the test method, you first need to understand the cause of the formation of the porosity bubble in the die-cast rotor.
1. The causes of air bubbles in cast aluminum rotor
1. When casting aluminum rotor, the aluminum water cleaning treatment is not proper, the aluminum water contains gas seriously, the casting speed is too fast or the exhaust tank is too small, which will lead to the gas in the mold can not be discharged, resulting in stomatal bubbles;
2. When pouring cast aluminum rotors, the preheating temperature of the iron core does not reach the standard temperature, the temperature is too low, and the oil stains are not burned out before casting aluminum, and the volatilization of oil stains will form pores and bubbles in the cast aluminum rotors;
3. When casting aluminum in a low-pressure environment, if the riser pipe leaks seriously, the compressor that should enter the crucible will enter the riser pipe, and enter the rotor together with the aluminum water, resulting in pore bubbles.
So how should we test the porosity and bubbles of die-cast rotors?
2. Test method for porosity and air bubbles in die-cast rotors
The most common method for testing die-cast rotors' porosity and bubbles is to use the die-cast rotor tester to test the cast aluminum rotor before leaving the factory.
The die-cast rotor tester uses sensors. When the rotating cast aluminum rotor is close to the sensor, the die-cast rotor tester amplifies the signal through the internal device of the special sensor and tests the air bubbles of the die-cast aluminum in a magnetic field environment.
When testing die-cast rotors, we need to do the following:
1. First of all, it is necessary to install the rotor under test, adjust the relative position of the sensor and the part under test, and set the test parameters, then press the two-handed start buttons on the left and right sides at the same time to start the test, or click [Start] on the test interface ] button to start the test.
2. When the cast aluminum rotor test starts, the power motor starts to run, driving the tested cast aluminum rotor to rotate, and the sensor transmits the collected data to the internal signal processing unit of the system, and then displays it in the form of a waveform on the LCD screen. As shown below:
If there are pores and bubbles in the die-cast rotor, [red background] will be displayed in the item column of [Thin Bars] in the display interface of the display screen, which means that the guide strip where the pores are located has pores and bubbles, and the overall guide strip shows thin strips. At the same time, it will be presented as a red waveform segment below the data, which is very intuitive;
3. After the test of the cast aluminum rotor is completed, multiple volumes of the cast aluminum rotor number, name, model, and test time can be obtained in the [cached data] area of the test system. A support waveform comparison of multiple cast aluminum rotors, making it easier to identify the air bubbles in the rotor pores.
AIP has always been committed to the technical research and development of motor testing. Relying on a strong scientific research team, up to now, the Die-cast rotor tester includes vertical conventional die-cast rotor tester, horizontal conventional die-cast rotor tester, and vertical Four categories: full-function cast aluminum rotor tester and horizontal full-function die-cast rotor tester.
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