Caterpillar cat315 excavator, short arm type bucket capacity up to 4 cubic meters, high power, high efficiency, using mechanically actuated electronically controlled unit injector (EUI) fuel system, EUI unit injector The mechanical force generated by the camshaft is used to generate high injection pressure.This device combines the pumping element, electronic fuel metering element and fuel injection element in a single device. The electronic control system is designed to the engine fuel system and Engine intake and exhaust system for electronic control of fuel delivery and injection timing. Compared with conventional mechanical engines, the electronic control system can provide enhanced timing control and fuel-air mixture ratio control. It is achieved by precise control of the ignition timing of the fuel injection. The engine speed per minute is controlled by adjusting the duration of the fuel injection.
The computer board of the Caterpillar cat315 excavator has the owner's control board.Because the handle is an electronic control handle and the engine is an EFI engine, the electrical signals of various input and output are more than those of the general model, so the computer board is more powerful and the monitor There are parameter keys on it, which can call up many important parameters of the locomotive and engine, such as the output signal of the electric control handle, the current value of the pilot proportional solenoid valve that controls the action of each mechanism on the main control valve, and the power shift of the main pump and the rotary pump The current of the pressure reducing valve, the signals of various important sensors of the engine, etc.
When the engine cannot get into the vehicle, the possible cause is a problem with the starting circuit, or a fault in the fuel supply, or a mechanical fault.
Repair process:
Because it occurred under the condition of normal shutdown, the possibility of mechanical failure is very small. Turn on the key to turn on the power.If there is a circuit failure, the content and fault diagnosis code will be displayed in the information display center of the monitor. The display shows that the coolant level is low, because this display already exists, it is a fault of the sensor, and does not affect the start. Press the main menu key of the monitor to adjust the line to diagnose the fault and the code, because there is no other fault display, you can ignore the circuit first The reason is that when the test is started, the starting motor can rotate and the starting speed is enough, which can eliminate the possibility of problems in the starting circuit and the lack of battery voltage, and the engine sound is normal, and there is no abnormal noise. First eliminate the possible causes of the oil circuit.First, exhaust the air, there is no air in the oil circuit, and the hand pump feels a lot of pressure when pumping oil, and the fuel pressure is sufficient.
Fault diagnosis code, at this time it shows that the coolant level is low, because this display already exists, it is a fault of the sensor, and does not affect the start, press the main menu key of the monitor, and the line diagnostic fault and code appear, because there is no other fault display No need to consider the reasons of the circuit first. When the test is started, the starter motor can rotate and the starting speed is enough, which can eliminate the possibility of problems in the starter circuit and the lack of battery voltage, and the engine sound is normal and there is no abnormal noise.
First, eliminate the possible causes of the oil circuit.First, exhaust the gas, there is no air in the oil circuit, the hand pump feels a lot of pressure when pumping oil, the fuel pressure is sufficient, check the fuel pressure adjustment valve (back pressure valve), there is no problem, oil There is no leakage or blockage on the road, and the cause of the oil circuit can be preliminarily eliminated. In order to further confirm that the circuit is not faulty, it is necessary to check whether there is current to the electronically controlled single-unit injector, because there is no special Caterpillar electronics Technician (ET) testing tool, so the test light is used for testing. After testing, the test light is on, indicating that the circuit is normal and there is current to the injector, so the preliminary judgment is that the single injector is faulty because of the fuel injection of this machine. The fuel injector has been used for more than 5,000 hours.Because the fuel quality at the construction site is very poor, the plunger, spool, nozzle, etc. inside the electronically controlled single-unit injector have been worn out, resulting in fuel atomization and fuel injection. The technical standard makes the cat 315 excavator engine unable to catch the car.
The locking hoist of the two-way hydraulic lock when the directional valve works in the left position, the pressure oil will enter the left cavity of the hydraulic cylinder from the left hydraulic control check valve and will open the right hydraulic control check valve through the control port so that the hydraulic cylinder The oil return from the right chamber can flow back to the mailbox through the right hydraulic check valve.
