Engine speed control principle

Throttle is to control the throttle, and the corresponding oil increases with the increase of air intake. The more mixed gas enters the cylinder, the greater the gas pressure produced by combustion, and the faster the piston is pushed, that is, the faster the rotation speed. The air intake of the engine will not be infinite, so there will be the highest speed.

The working medium entering the cylinder is pure air. Due to the small resistance of the intake system of diesel engine, the intake terminal pressure PA = (0.85 ~ 0.95) P0, which is higher than that of gasoline engine. The final intake temperature ta = 300 ~ 340 k, which is lower than that of gasoline engine.

When the compression stroke draws to a close, diesel oil is injected into the cylinder combustion chamber at a high pressure of about 10MPa under the action of a high-pressure oil pump, and it is ignited immediately after being mixed with air in a short time.

Extended data:

The exhaust of diesel engine is basically the same as that of gasoline engine, but the exhaust temperature is lower than that of gasoline engine, tr = 700 ~ 900 K. For single-cylinder engine, its speed is uneven, the engine works unsteadily and vibrates greatly.

This is because only one of the four strokes does work, and the other three strokes consume power to prepare for work. In order to solve this problem, the flywheel must have enough moment of inertia, which will lead to the increase of the mass and size of the whole engine.

Multi-cylinder engine can make up for the above shortcomings. Modern cars mostly use four-cylinder, six-cylinder and eight-cylinder engines.