Now the car engines are all internal combustion engines. It is a machine that converts the chemical energy of fuel into mechanical energy. It has been invented for more than one hundred years. Although technical progress has been made, performance and efficiency have greatly improved, but its basic The structure and working principle have not changed. They are basically divided into two categories: gasoline engine and diesel engine. They are composed of two major mechanisms and five major systems, namely, crank and connecting rod mechanism, gas distribution mechanism, fuel supply system, lubrication system, cooling system, and ignition system. Starting system. The biggest difference between a gasoline engine and a diesel engine is that the diesel engine does not have an ignition system, and the fuel supply systems of the two are also very different.
1, crank connecting rod mechanism
Crank and connecting rod mechanism is the main moving part of the engine to realize the working cycle and complete the energy conversion. It is composed of body group, piston connecting rod group and crankshaft flywheel group.
2, valve mechanism
The function of the valve train mechanism is to open and close the intake and exhaust valves at regular intervals according to the working order and working process of the engine, so that the combustible mixture or air enters the cylinder, and the exhaust gas is discharged from the cylinder to realize the ventilation process. The engine's gas distribution mechanism is more and more complex, the purpose is to allow more air to enter the cylinder to participate in the combustion, in order to improve the engine's power and efficiency. It is mainly composed of the camshaft, valve, valve lifter and other components.
3, lubrication system
The function of the lubrication system is to send a fixed amount of clean lubricating oil to the surface of the parts that are moving relative to each other to achieve liquid friction, reduce frictional resistance, and reduce the wear of the parts. The surface of the parts is cleaned and cooled. The lubricating oil is usually made of lubricating oil. Road, oil pump, oil filter and some valves and other components.
4, cooling system
The function of the cooling system is to dissipate some of the heat absorbed by the heated parts in time to ensure that the engine works at the optimum temperature. The cooling system of a water-cooled engine is usually composed of a cooling water jacket, a water pump, a fan, a water tank, a thermostat and the like.
5, Fuel Supply System
The function of the gasoline engine fuel supply system is to formulate a mixture of a certain amount and concentration according to the requirements of the engine, feed it into the cylinder, and discharge the burned exhaust gas from the cylinder to the atmosphere. There are many fuel supply systems for gasoline engines and diesel engines. The difference, relatively speaking, diesel engine is more complex, the system pressure is higher. It is mainly composed of fuel pump, fuel tank, tubing, fuel injector and so on.
6, Ignition system
In a gasoline engine, the combustible mixture in the cylinder is ignited by sparks. For this purpose, a spark plug is mounted on the cylinder head of the gasoline engine, and the head of the spark plug extends into the combustion chamber. All equipment capable of generating sparks between the spark plug electrodes on time is called The ignition system and the ignition system are usually composed of a battery, a generator, a distributor, an ignition coil, a spark plug, etc. The diesel engine is ignited, so there is no such system.
7, starting system
To make the engine transition from the static state to the working state, the crankshaft of the engine must be turned with an external force to make the piston reciprocate. The combustible mixture in the cylinder burns and expands to perform work, and the piston is driven to move downward to rotate the crankshaft. The working cycle can be performed automatically. Therefore, the crankshaft begins to rotate under the action of the external force until the engine starts the automatic idling operation. It is called the starting of the engine. The device required to complete the starting process is called the starting system of the engine.
During the work process of the engine, the above agencies and systems coordinate with each other to make the engine run smoothly. The operation is smooth and smooth. This is the engine tuning effort. Some engines have the same hardware but the performance is completely different. Engine tuning is not the same.