Illustrate that the little knowledge in the car is no longer car blindness.
The accelerator is actually an "air door". When driving, you should step on the accelerator pedal, also known as the accelerator pedal. If you step on it, the car will accelerate.
Although commonly known as the accelerator pedal, it does not directly control the fuel injection quantity, but controls the intake air quantity, which is equivalent to a "throttle". When stepping on the accelerator pedal, it will open a valve called "throttle" wider, thus allowing more air to enter the engine.
The engine computer can determine the amount of fuel injected into the engine according to the amount of air inhaled and the ideal oil-gas mass ratio (gasoline: air = 1: 14.7, that is, 1 g gasoline demand 14.7 g air).
In this way, the more air enters, the more fuel is injected. When the air volume and fuel volume increase, the explosion in the combustion chamber will be more intense, thus generating more powerful force. Under the action of more powerful force, the piston will further push the crankshaft to rotate faster or output more torque, which will make the wheels of the car rotate faster, so that the car will accelerate.
This is the throttle valve on the engine, which is located between the intake pipe and the intake manifold and is responsible for controlling the intake air volume. When you step on the accelerator pedal, you will directly open the intake valve wider and let more air in, so that the engine computer will give instructions to spray more oil and the car will accelerate.
The piston is like pedaling a bicycle, and the cylinder is where the power is generated. However, a reliable and effective way is needed to transfer huge power out of the cylinder and convert the force generated by the linear motion of the piston into the force of wheel rotation.
This transformation process is very similar to the way we ride bicycles. The piston is equivalent to our thighs or knees, and the connecting rod is our calves. Needless to say, the crankshaft of the engine is the crank of the bicycle.
Driven by the piston and connecting rod, the crankshaft rotates continuously, and the power output by the crankshaft is finally transmitted to the wheels through transmission devices such as transmission, which makes the wheels rotate and the car move forward or backward.
Nearly 70% of the fuel is wasted. The principle of the car is to convert fuel into kinetic energy to push the car forward. But you may not believe it, 69% of the fuel added by the car has not been converted into effective power to push the car forward, and they will be consumed before reaching the wheels.
As long as the engine is running, the output end of the engine will have power output. But sometimes cars don't need power, for example, they don't need power when parking, or even when driving and taxiing.
But the engine can't be turned off during driving, so there must be a "power switch" on the car, and the driver can turn off and turn on the power output by the engine according to the driving situation. This switch is the clutch.
Clutches seem to exist only in cars with manual transmission. The pedal stepped on by the left foot is a clutch pedal. When the clutch pedal is depressed, the power output of the engine is cut off, and it is lifted and then closed. In fact, there are many clutches in the automatic transmission, which are just integrated inside the automatic transmission and do not need manual operation.
The continuously variable transmission has no speed change gears, but only a pair of pulleys whose diameters can be changed. One is the driving pulley, which is equivalent to the driving gear in the manual transmission; The other is driven pulley, which is equivalent to the driven gear in manual transmission.
In order to change the transmission ratio of the transmission, the manual transmission can only change the gear pairs of different gears (that is, a pair of gears), while the pulley diameter in the continuously variable transmission can be changed without changing other pulley groups.
When the diameter of the driving pulley increases and the diameter of the driven pulley decreases, or when the diameter of the driving pulley decreases and the diameter of the driven pulley increases, the power transmission ratio or output speed of the transmission can be changed.
Why can the diameter of pulley be changed? In fact, each pulley is composed of two conical disks, and the edge of the transmission steel belt is an inclined plane, which just runs in with the conical surface of the pulley. When the distance between the two conical discs of the pulley changes, the steel belt will move up and down along the conical surface, which is equivalent to changing the diameter of the pulley.
Continuously variable transmission has the advantages of fuel saving and comfort, no feeling of shifting gears and lack of driving pleasure. The piston and connecting rod are equivalent to the two legs of a person riding a bicycle, and the crankshaft below it is equivalent to the crank of a bicycle. Have you ever thought about it? Is it better to ride a bicycle with four legs or eight legs?
No, but the car can. An automobile engine can have eight or even 16 legs and pedal a crankshaft together. Different from the human body, the legs of automobile engines can be arranged in several ways, such as linear (L-shaped), V-shaped, W-shaped and horizontally opposed (B-shaped).
Single cylinder: Small engines on lawn mowers generally use single cylinder. Because there is no other cylinder to balance its vibration, the vibration of the lawn mower is quite severe.
V-type 2-cylinder (V2): A V-type 2-cylinder engine is generally used on motorcycles. The piston is relatively large, and the up-and-down movement is not particularly fast, so the sound of motorcycles is relatively loud.
In-line 3-cylinder (in-line 3): 3-cylinder engines are often used in mini-cars with displacement less than 1 liter, such as Suzuki New Alto and Li Xia. The three-cylinder engine has the advantages of light weight, simple structure and low manufacturing and maintenance costs.
In-line 4 cylinders (straight 4): This is the most common cylinder arrangement for ordinary cars. 1 rises to 2 liters, and even Toyota's 2.7-liter engine uses an in-line 4-cylinder engine. The inline four-cylinder engine is compact, quiet, simple and reliable.
In-line 5 cylinder (straight 5): I want to improve the displacement of 4 cylinder, but I think the volume of in-line 6 cylinder is too large to be placed under the hood, so the best way is to use in-line 5 cylinder. Although the in-line 5 cylinder is not the best balanced layout, it is smoother than the in-line 4 cylinder, and to some extent, the sound of the in-line 5 cylinder is more beautiful. At present, Volvo cars mostly adopt in-line 5-cylinder layout.
In-line 6-cylinder (straight 6): Theoretically, in-line 6-cylinder engine is the best balanced layout. However, at present, only BMW cars may use the inline six-cylinder engine, and the 3.0-liter inline six-cylinder engine has become a classic design of BMW. Although the engine is large, BMW does not have a front-wheel drive model, either rear-wheel drive or four-wheel drive, so there is no need to place too many transmission and driving parts in the engine compartment. Therefore, it is easy to place the long inline 6-cylinder engine under the hood.
Four-cylinder horizontally opposed (B4): The pistons of four-cylinder horizontally opposed engine are arranged oppositely, so this kind of engine is also called BoxerEngine, abbreviated as B4 engine. Its four pistons are like the fists of two boxers fighting each other. Horizontally opposed engine's center of gravity is low, which is conducive to the handling of the car. It's just that this engine has a strange sound, especially when there are many cylinders. At present, only Subaru has the level of production and use, and the four-cylinder engine is opposed.
Six cylinders are horizontally opposed (B6): If two fists are added to the four-cylinder horizontally opposed engine, it becomes a six-cylinder horizontally opposed engine. At present, only Porsche and Subaru oppose the 6-cylinder engine at the production and use level. Ferrari once built 12 engines with horizontally opposed cylinders.
V-type 6-cylinder (V6): Divide the inline 6-cylinder into two rows with 3 cylinders in each row, and then make the two rows of cylinders into V-type, which is the V-type engine. V6 engine is not as quiet and smooth as straight-6 engine, but its sound is very pleasant, and its volume can be reduced, so it can be placed under the hood of front drive, so it is used more now.
V-8 cylinder (V8): Every four cylinders are arranged in a row and then in a V-shape, which is the favorite V8 engine for car enthusiasts. Engines with a displacement of more than 3.5 liters basically adopt a V-shaped 8-cylinder layout. Large SUVs, sports cars and other vehicles that pursue strong power like to use V8 engines. V8 engine is almost synonymous with powerful power.
W-type 8-cylinder/12 (W8/W 12): There are two types of W-type engines, one is the W-type 8-cylinder engine used by Volkswagen in Passat, and the other is the 6.0-liter W-type12-cylinder engine used by Audi A8. They all use only one crankshaft. The W-type 16 cylinder engine used by Bugatti adopts two crankshafts. The W8 and W 12 engines originally belonged to V-type engines, but the cylinders on each side were arranged in a small staggered way instead of a straight line, and they also used crankshafts.