Squeeze casting pressure sensor

In order to accurately measure the interface pressure of squeeze casting die, Kistler 6175a2 pressure sensor is used for measurement, as shown in Figure 1. The sensor is a quartz piezoelectric sensor. When the pressure acts on the quartz induction unit, the corresponding charge will be generated. The charge is transferred to the charge amplifier through a special data cable. After the conversion of the charge amplifier, the charge is converted into 0-10V which is proportional to the pressure The output voltage can be converted into the corresponding pressure value by the data acquisition instrument. The flow chart of pressure measurement is shown in Figure 2. The rated pressure that the pressure sensor can measure is 200MPa. The pressure sensor is directly in contact with the high temperature melt. Because the piezoelectric elements are sensitive to temperature, the temperature of the melt contacted by the pressure sensor can not exceed 850 โ„ƒ.

(a) Physical drawing of pressure sensor (b) size of pressure sensor

As shown in Figure 1 (b), the size of the pressure sensor is given. When the pressure sensor is installed on the die, its measuring end face must be flush with the lower surface of the die cavity of the squeeze casting die, becoming a part of the die cavity surface. In addition, because the pressure sensor is expensive and easy to damage equipment, there should be no impact during installation. In order to ensure that the pressure sensor can be smoothly installed into the installation hole, the size of the installation hole must be 0.01mm or 0.02mm larger than + 0.018012mm.

According to the working principle of the pressure sensor, the charge transferred in the data line is the charge measured by the pressure sensor, and the amount of charge is very small. After that, the data can be collected only after charge amplification. Therefore, when arranging the data line as shown in Figure 2, the interference of vibration source and electromagnetic field should be avoided as far as possible, otherwise the measured data will be easily distorted.