The fuel injector is an important part of the diesel engine fuel system, and its function is to inject an appropriate amount of fuel into the combustion chamber at a certain pressure and angle according to the different working conditions of the diesel engine, and mix it with air to provide power for the diesel engine. Caterpillar C7 and C9 injectors are two different types of injectors produced by Caterpillar, and their structure and working principle have certain differences.
1. Carter C7 injector structure.
The CAT C7 injector is composed of an injector, a pressure regulator, an injector body and a connecting rod. The fuel injector is composed of a needle valve and a spring, and the pressure regulator valve is composed of a pressure regulating spring, a pressure regulating screw and a pressure regulating spring seat. There are oil channels inside the injector body that connect the injector and the regulator. The function of the connecting rod is to fix the injector on the cylinder head and transmit the vibration and pressure of the cylinder head to the injector.
Second, the structure of Carter C9 injector.
The CAT C9 injector is composed of a fuel injector, a pressure regulator, a connecting rod, a filter screen and an injector body. The structure of the injector and regulator is similar to that of the Carter C7 injector, but with the addition of a strainer on the connecting rod to filter impurities and particulate matter from the fuel entering the injector. The injector body has oil channels and seals inside to seal the fuel and prevent oil leakage.
Third, the working principle.
When the diesel engine is working, the high-pressure fuel is filtered through the fuel filter and enters the injector body, and reaches the injector through the oil channel. At the needle valve of the fuel injector, the fuel is subjected to high pressure, overcomes the resistance of the spring, opens the needle valve, and enters the combustion chamber. Under the action of the pressure regulator, the pressure of the injector remains constant, and at the same time, the opening time of the injector and the amount of fuel injection are adjusted according to the different working conditions of the diesel engine to meet the needs of the diesel engine.
4. Characteristics and differences.
There are certain differences in the structure and working principle of the Carter C7 and C9 injectors. The regulator of the Cat C7 injector is on the outside of the injector body, while the regulator of the Cat C9 injector is on the inside of the injector body. In addition, a filter screen is added to the connecting rod of the Cat C9 injector, which can better filter impurities and particulate matter in the fuel, improve the cleanliness of the fuel and the service life of the injector.
In a word, the structure and working principle of the Cat C7 and C9 injectors have certain differences, but they are both important components in diesel engines. Understanding its structure and working principle helps in better maintenance and use of diesel engines.