How Does a Sedan Move?
3 Answers
A sedan moves through the combustion and explosion of a fuel-air mixture in the cylinders, which drives the pistons in a reciprocating motion. This motion turns the crankshaft, which is connected to the transmission via the clutch. The power is then transmitted through the driveshaft to drive the wheels, propelling the vehicle. Below is a detailed introduction to how a car moves: 1. Body Composition: The car body is mounted on the frame of the chassis and is used for the driver, passengers, or cargo. The body of passenger cars and buses is generally a unitary structure, while the body of trucks usually consists of two parts: the cab and the cargo compartment. 2. Chassis Composition: The chassis is composed of the drivetrain, running gear, steering system, and braking system. The chassis serves to support and install the car engine and its various components, forming the overall shape of the car. It also receives the power from the engine to generate motion and ensure normal driving. The chassis consists of five parts: the drivetrain, running gear, steering system, suspension system, and braking system. 3. Engine Composition: The engine is the power unit of the car, consisting of 2 major mechanisms and 5 major systems: the crankshaft and connecting rod mechanism, valve train, cooling system, fuel supply system, lubrication system, ignition system, and starting system. However, diesel engines lack an ignition system compared to gasoline engines.
The car can run thanks to its heart—the engine, just like how we need our heartbeat to provide energy for running. Fuel is ignited inside the engine, and the explosive force drives the pistons to move up and down, similar to continuously punching the air to generate thrust. The pistons then rotate the crankshaft, which, through the transmission—these 'smart shoes'—adjusts the speed and finally transfers the power to the tires. The tires act like shoes, gripping the ground with their treads to roll forward. The steering wheel serves as the guide, and the brakes act as the emergency stop switch. The entire system works together to ensure a smooth ride on the road. I remember the mechanic saying during my last repair that the force generated by the engine alone could lift half a ton—no wonder a press on the accelerator can propel the car so far ahead.
The most magical moment when driving is pressing the accelerator: with a gentle push of the foot, the engine tachometer needle instantly jumps, and the car surges forward. Behind this lies a precise energy transfer chain—the throttle controls the air intake, gasoline mixes with air and explodes in the cylinder, the spark plug 'snaps' to ignite the mixture, and the piston is instantly pushed into motion. I always imagine this process as a relay race: the piston transfers power to the crankshaft, the crankshaft to the transmission, which selects the right gear and sends it to the tires. When the tires contact the ground, they emit a slight tremor, and this frictional reaction force propels the car forward. If the steering wheel turns just a few degrees, the entire car obediently follows, more responsive than a horse's reins.
