The working principle of excavator pressure sensor and pressure switch

Excavator Pressure Sensor

The Komatsu pressure sensor is shown in Figure 4-20. When oil enters from the pressure inlet and pressure is applied to the diaphragm of the oil pressure detector, the diaphragm bends and deforms. The measurement layer is mounted on the opposite side of the diaphragm, and the resistance value of the measurement layer changes, changing the curvature of the diaphragm into an output voltage, which is transmitted to a voltage amplifier, which further amplifies the voltage, which is then transmitted to an electro-mechanical controller (computer board).

excavator sensor

Figure 4-20


The higher the pressure on the sensor, the higher the output voltage; according to the sensing pressure, the pressure sensor is usually divided into two types: high pressure sensor and low pressure sensor. The high pressure sensor is used to measure the output pressure and load pressure of the main pump. Low pressure sensors are used in pilot control systems and oil return systems.

The common working voltages of pressure sensors are 5V, 9V, 24V, etc. (special attention must be paid to distinguish when replacing). In general, pressure sensors on the same machine operate at the same voltage. The working current of the pressure sensor is very small, and it is directly powered by the computer board.


Excavator Pressure Switch

The pressure switch is shown in Figure 4-21. The pressure switch detects the pressure state (on/off) of the pilot circuit and transmits it to the computer board. There are two types of pressure switches: normally-on and normally-off, depending on whether the circuit is connected when there is no pressure at the port. Different models and different parts of pressure switches have different actuation pressures and reset pressures. Generally, pressure switches for rotary and work equipment have lower actuation pressures, while pressure switches for walking have higher actuation pressures.

Excavator Pressure Switch


Figure 4-21



Post time: Jun-19-2022