What is the function of the engine valve train?
4 Answers
The function of the engine valve train is to: regularly open and close the intake and exhaust valves of each cylinder, allowing fresh combustible mixture (for gasoline engines) or air (for diesel engines) to enter the cylinder in a timely manner, and exhaust gases to be expelled from the cylinder promptly. During the compression and power strokes, the valves close to ensure the sealing of the combustion chamber. The valve train is the mechanism that controls the intake and exhaust of the engine. It regulates and organizes combustion by controlling the intake and exhaust of the engine's combustion chamber according to the working cycle and ignition sequence requirements of each cylinder, including intake volume, intake timing, and exhaust timing.
I've driven quite a few cars, and I think the function of the engine valve train is like making the engine breathe properly. It opens and closes the intake and exhaust valves at the right time, allowing air and fuel to smoothly enter the cylinder for mixing and combustion, and then expels the exhaust gases. This thing directly affects the engine's power output. When driving, whether you feel strong acceleration or high fuel consumption is related to it. I remember when my car's valve clearance wasn't adjusted properly, the engine vibrated badly and struggled on slopes; after adjustment, the car ran much smoother and quieter. The valve train is usually driven by a timing belt or chain to maintain synchronization. If the belt ages and breaks, the engine will just stall. It's important to regularly check the valve condition—don't wait until it fails to regret it.
As a driver who frequently takes long-distance trips, the valve train system is crucial for my driving comfort. It controls the opening and closing of valves, allowing the engine to intake and exhaust air, ensuring smooth vehicle operation. When I press the accelerator to speed up, the valve train system lets more air in to help the engine generate power; at idle, it operates slowly to reduce vibrations. If this system malfunctions—for example, if the valve springs become fatigued—the engine will shake violently, accelerate sluggishly, consume more fuel, and may even exceed emission standards, harming the environment. I once encountered a situation where carbon buildup clogged the valves, making the car hard to start. After repairs, everything returned to normal. Regular maintenance can extend the engine's lifespan and make driving safer.
In the repair shop, I've encountered many faults in the valve train. Its role is to precisely control the opening and closing timing of the valves, ensuring the proper intake of air-fuel mixture into the cylinders and smooth exhaust gas expulsion. The engine's smooth operation entirely depends on it. If valves don't open on time, incomplete combustion can lead to power loss or abnormal noises. Common issues include incorrect timing, valve wear, or sealing leaks, requiring regular clearance checks and adjustments. Proper maintenance can prevent major overhauls and improve overall efficiency.
