Which sensors are in the electronic control system? What are the characteristics? The sensor is a detection device that can sense the information being measured and can transform the information sensed by the detection into electrical signals or other required forms of information output in accordance with certain laws to meet the transmission, processing and storage of information. Requirements for display, recording and control. It is the first link to achieve automatic detection and automatic control. Sand Pump,Sand Suction Dredging Pump,Sand Dredge Pump Hebei Yongquan Pump Industry Co., Ltd. , http://www.cnsolarpump.com
1. Air flow sensor: The hot film air flow sensor is installed on the intake air pipe of the engine to measure the air flow entering the engine. The air flow sensor is actually a combination of an air temperature sensor and an air pressure sensor. The feedback information of the air flow sensor is an important basis for the ECU to calculate the fuel injection amount. The four terminals of the sensor are connected to the four terminals of the ECU.
2. Flywheel (motor) speed sensor: The flywheel speed sensor can also be called an engine speed sensor. It is an inductive sensor. There are 58 signal generating holes on the flywheel front face and two blank positions. The flywheel speed sensor head, which is fixed to the cylinder, will directly sense these position changes. The position signal of the missing hole detected by each rotation of the engine flywheel is a reference signal that the electronic control unit (ECU) recognizes the position of the piston of the first cylinder to the top dead center. This signal is used by the ECU to achieve the injection and pre-injection advances and fuel injection times. At the same time, this signal is converted by the ECU to the engine tachometer to indicate the engine speed. The two terminals of the flywheel speed sensor are connected to the ECU terminals A29, A37 with wires. During installation, the gap between the sensor head and the flywheel is 0.8~~1.5mm and it is vertical. If the clearance and position are not proper, check and adjust the sensor bracket and tighten the bolt finally.
3. Coolant temperature sensor: The coolant temperature sensor is an NTC type sensor, ie, the temperature rises and the resistance value becomes smaller. It uses the NTC thermistor as a sensing element, measures the resistance of the coolant at different temperatures, and then converts it into a 0~~5V voltage signal to the ECU so that the ECU can issue work instructions to the relevant actuator. The resistance values ​​of the coolant temperature sensor at different temperatures are as follows: -40°C, 48.5kΩ, -20°C, 15.67kΩ, 0°C, 5.86kΩ, and 20°C. For 2.50kΩ, the resistance value is 1.17kΩ at 40°C, 0.59kΩ at 60°C, 0.32kΩ at 80°C, and 0.18kΩ at 100°C. Where the cooling fluid temperature bed is mounted on the thermostat seat, the two connecting terminals of the plug-in U are respectively connected to the A1 and A30 terminals of the ECU with wires. When the coolant temperature exceeds 98°C (or reaches 105°C), the ECU control center will let the electromagnetic cooling fan work. In the heat exchanger in which the coolant radiator and the air conditioner condenser are integrated, the RCU also turns off the electromagnetic clutch of the air conditioner compressor and stops the air conditioner.
4, camshaft phase sensor: camshaft position to insert u that is to take the sensor, the plug u take that two wire terminals with wires and ECU's A4 and A31 two terminals connected. It is used by the ECU to determine the end point of the compression stroke of each cylinder piston of the engine (the intake and exhaust valves are closed at the same time), which is an important reference point for determining the injection timing (pre-injection and main injection) of the electronic control injector. The camshaft position is inserted into the cylinder head cover, and the sensor head is aligned with two adjacent bosses and vacant positions on the inner edge of the camshaft drive gear, so that the ECU can obtain the timing of the pre-spray and the main spray. information. The air gap of the sensor head is 0.8~~1.5mm. If it is improper, the position of the bracket can be adjusted. When the camshaft position is inserted at the temperature of 20°C, the normal resistance value is 86kΩ.
5. Fuel temperature sensor: The fuel temperature sensor contains the fuel plug plugged in. It is also an NTC type sensor. It is assembled on the fuel filter assembly and is connected to the A15 and A30 terminals of the ECU by wires. When the fuel temperature exceeds 70 °C, the electronic control center ECU will reduce the fuel injection pressure; when the fuel temperature exceeds 90 °C, the engine power will be reduced to 60%.
6, clutch pedal sensor and brake sensor: respectively installed in the clutch pedal and brake pedal support, the same structure and principle. The normal state is a closed circuit, and the depressed state is a cut-off circuit. When the pedal is pressed, the ECU presses the circuit to cut off the signal, rapidly reducing the fuel injection of the electronically controlled injector; the brake pedal also causes the rear brake light to light up.
7. Fuel pressure sensor: The fuel pressure sensor is installed on the common rail pressure accumulator and provides common rail fuel pressure information. It has a semiconductor pressure-sensitive strain-resistor type bridge circuit inside, which converts the received fuel pressure signal into an electric signal. After calculation and amplification, 0.5~~4.5V voltage signal is output to the ECU, and the electronic control unit will control accordingly. The fuel pressure regulator valve corrects the fuel pressure to a suitable level. The fuel pressure sensor 3 and the wire are respectively connected to three terminals A6, A14 and A33 of the ECU.
8. Accelerator pedal position sensor: The accelerator pedal position sensor is composed of a position sensor and an idle switch and is an accelerator pedal-dedicated device. The position sensor is a sliding potentiometer, which feeds back the accelerator pedal throttle voltage signal at any time to the ECU. The input voltage is 5V and the gas gate resistance is 1kΩ. When the accelerator pedal is completely released and the ignition switch is turned off, the electronic control unit ECU receives the signal and immediately cuts off the fuel supply of the electronic fuel injector. When the engine reaches the minimum speed, the idle switch is turned on to maintain the stable operation of the engine. The position sensor leads are connected to the ECU terminals B2, B13, B27, and B35, respectively.
9. Atmospheric pressure sensor: The atmospheric pressure sensor is located inside the ECU and can measure the atmospheric pressure at different altitudes and convert it into electrical signals for the ECU to correct the fuel injection at different altitudes.