SINOTRUK HOWO -Oil Sensor- Spare Parts For SINOTRUK HOWO Engine Part No.:WG9625550133

Relevant Knowledge

Operating principle of oil pressure sensor

The oil pressure sensor is installed on the main oil duct of the engine. When the engine is running, the pressure measuring device detects the pressure of the oil, converts the pressure signal into an electrical signal and sends it to the signal processing circuit. After voltage amplification and current amplification, the amplified pressure signal is connected to the oil pressure indicator through a signal wire, changing the ratio of the current passing through the two coils inside the oil pressure indicator, thereby indicating the oil pressure of the engine.

The function of the oil pressure sensor

(1) The door potentiometer type pressure sensor diesel engines are lubricated by lubricating oil. Once the lubricating oil pressure is too low, dry friction will occur due to lack of oil, causing severe wear and heat, thus damaging the diesel engine. Therefore, diesel engines are equipped with oil pressure measuring devices to monitor the lubricating oil pressure. At present, Cummins diesel engines use potentiometer pressure sensors to measure oil pressure. The sensor consists of a corrugated diaphragm and a sliding wire potentiometer. When the oil pressure of the diesel engine changes, the corrugated diaphragm produces displacement, which drives the contact on the potentiometer to slide, thus changing the resistance value. Under the single wire system, the sensor has a terminal, in which the potentiometer is connected to the diesel engine control unit or oil pressure indicator through a wire, and the other pole is grounded. When connected with the oil pressure indicator, if the resistance of the potentiometer changes, the current passing through the inner coil of the oil pressure indicator will change, which will drive the pointer to deflect and point out the lubricating oil pressure value. When the oil pressure increases, the variable resistance value of the sensor decreases, and the output current increases. When the oil pressure decreases, the situation is exactly the opposite. When connected to the control unit, the sensor potentiometer and the ECU's internal pull-up resistor generate a voltage that changes with the resistance of the potentiometer. The diesel engine ECU measures the diesel engine lubricating oil pressure according to this voltage change. The sliding wire potentiometer in this oil pressure measuring device has a mechanical contact, and this contact must pass a current up to 100mA. However, the diesel engine has a large vibration, which affects the mechanical and electrical life of the sensor to some extent. (2) The switch type pressure sensor lubricating oil pressure switch is also used to detect diesel engine oil pressure, which is composed of a diaphragm, contacts, and springs. During operation, when the diaphragm of the oil pressure switch has no pressure effect, the contact is closed under the action of spring force; When pressure is applied to the membrane, the spring is compressed and the contacts open. The switch type pressure sensor is generally connected to the oil pressure indicator light, and the working principle diagram of the switch type oil pressure indicator is shown. When the diesel engine does not have lubricating oil pressure, the diaphragm is under pressure, and the contact of the oil pressure switch is closed, and the oil pressure indicator light is on; When the oil pressure of the diesel engine is normal, the diaphragm is subjected to pressure and compresses the spring, causing the contacts to open and the oil pressure indicator light to turn off. Some oil pressure sensors combine the potentiometer type and switch type structures. If the negative pole is grounded, there are two terminals, one of which outputs the resistance change signal of the potentiometer, and the other outputs the switch signal--------------------- Author: Sensor Leader Source: Sensor Expert Network Original text: https://www.sensorexpert.com.cn/article/2289.html Copyright statement: This article is organized and published by Sensor Expert Network. Please indicate the source and link when reprinting!