Maybe you have reached the acme of perfection in understanding various models. No matter what kind of car, just take a look automative lighting Conceptual knowledge about this car will flow out of my memory like mercury. But this is only a superficial understanding. Maybe you don't really understand the meaning of the car. To really understand cars, you must explore deeper levels, such as engine 。 This is like looking at a person, first of all to see whether he has a good heart.

If you admit that you are a fan, then you will certainly be familiar with the engine. Because it is so important for cars that we cannot ignore its existence. However, most people's understanding of engines is difficult to describe as "proficient", which is also normal. Because even many people in the industry who are called "experts" don't necessarily say every engine thoroughly.

In fact, understanding the engine is a necessary and sufficient condition for understanding the car. In other words, only when you understand the engine can you really understand the car. We conducted a "carpet search" for engines in the "world", and then gathered all kinds of engines together to form this "search engine". Our goal is only one?? Through the comprehensive introduction and comparison of engines, you can understand and master the knowledge about engines more systematically and comprehensively.

Engine knowledge

Simply speaking, the engine is an energy conversion mechanism, which will gasoline （ diesel oil ）By burning gas in the sealed cylinder, which is pushed when the gas expands piston Work is converted into mechanical energy, which is the most basic principle of the engine. All engine structures serve energy conversion. Although the engine has gone through more than 100 years of history with the automobile, it has greatly improved in design, manufacturing, technology, performance and control, but its basic principles remain unchanged. This is an era of creativity. Those engine designers, Constantly integrate the latest technology with the engine, turn the engine into a complex electromechanical product, and make the engine performance nearly perfect.

Classification of engines

modern High technology is perfectly reflected in the engine, and some new technologies and new structures are widely used in the engine. For example, V12, V8 and V6 engines: they all refer to Cylinder Arranged in V shape, this engine makes full use of dynamic principle, has good stability Dafa Engine displacement, reduce engine height. For example, Audi A8 6.0 uses W12-12 cylinder V-array engine, BENZS600 uses V12-12 cylinder IV array engine, etc.

Generally, engines are divided into three cylinder, four cylinder, six cylinder and eight cylinder types according to the displacement. At present, 1.3L-2.3L displacement vehicles mostly use in-line four cylinder engines, which are characterized by small size, simple structure and convenient maintenance; More than 2.5L displacement generally adopts multi cylinder design, including six in-line cylinders, such as bmw ； There are also V-type 6-cylinder engines arranged at a certain angle on both sides, which can effectively reduce vibration and noise, such as Buick Vehicle series; Generally speaking, the larger the displacement, the higher the power of the engine. But now there are also some cars with small displacement to improve their power through turbocharging, multi valve, variable timing and other technologies.

Engine performance

Engine performance parameters are the parameters that can best reflect the working capacity of the engine, mainly including: displacement, maximum power and maximum torque.

The displacement is often associated with the engine power. The size of the displacement affects the engine power, and it is usually regarded as the standard for classifying high, medium and low grade vehicles. piston stay Cylinder Reciprocating up and down movement is made inside, so there must be a highest and lowest point for reciprocating movement. The cylinder volume swept by the piston from the lowest point to the highest point is called single cylinder displacement, and the total displacement of all cylinders is called engine displacement. The two concepts of maximum power and maximum torque are most easily confused. Some people think that the greater the power of a car, the greater the force. In fact, they are not. The same 300 horsepower can make the car run at a speed of more than 250 km/h on a sports car, but on a container car, the speed may be only 150 km/h at most, but it can drag 30-40 ton containers. The secret is that the torque of the two cars is very different. In brief, the power is shown at high speed. On the engine performance curve, it increases significantly with the speed, which determines how fast the car can run. The torque does not necessarily play at high speed. On the curve, it is relatively flat, which can determine the power of the car when driving, including acceleration.

When interpreting the engine parameters, we should pay attention not only to the power, but also to the torque parameters. We should also pay attention to the speed when the engine is at the maximum power and torque. Of course, a slightly lower speed is better.

Basic features of V10 engine

1. Titanium alloy bolts clutch The housing is fastened to the engine.

2. The carbon fiber air tank supplying air to the air injection system of the engine is located above the driver's head.

3. In the engine valve distribution system, each cylinder has 4 valves.

4. The fuel injection nozzle of the engine is made of a whole piece of metal.

five Camshaft Now it is driven by gear, while RS1 in 1989 renault V10 axle is used Belt Driven.

6 Valves are not used in the valve system Spring The valve is now controlled by compressed air.

7. In order to avoid steel pipes as much as possible, oil and water circulation channels are cast into the cylinder wall. What materials are used inside the engine?

Aluminium is the most commonly used material for Formula One racing engines today. In the 1980s, cast iron was completely replaced by lighter aluminum. Aluminium also replaces magnesium, which corrodes in contact with water. Only moving parts that must bear strong force can be made of steel. The basic distribution of materials is as follows:

Aluminium: 63% (cylinder head engine oil Disc, piston)

Steel: 29.5%（ Camshaft , curved wheel, timing gear)

Magnesium: 1.5% (oil pump Shell)

Carbon fiber: 1% (air tank, coil cover)

Titanium: 5%（ connecting rod 、 a fastening ）

More than 150 employees are required to manufacture an engine, including 28 engineers, 20 draftsmen, 35 engine mechanics, 8 electronic experts, 20 machinists and assemblers, 4 system engineers, 6 bench test technicians, 15 personnel engaged in procurement, production and inspection, and 15 management personnel. Turbocharged engines: Over the years, Formula One engines have become more compact, lighter and fuel efficient. At the same time, with the increase of power, turbocharging reached its peak from 1977 to 1988. The most advanced engines at that time, including bmw 、 Porsche 、 renault 、 Ferrari and Honda The verified power of is more than 1200 horsepower. This engine has changed the face of Formula One racing. In 1977, no one believed that the 1.5-liter turbocharged engine could beat the 3-liter naturally aspirated engine. This is probably the best engine in Formula One.

Terminology

Let's clarify several concepts related to engine

>>Piston dead center and stroke:

a) The two extreme positions where the piston reciprocates in the cylinder are called stop points. Piston separation crankshaft The farthest position from the center is called top dead center crankshaft The position where the center is placed is called the bottom dead center.

cool.gif The distance between the top and bottom dead center is called the stroke of the piston. The crankshaft rotates for half a circle, which is equivalent to the piston moving for one stroke.

>>Displacement

a) The piston reciprocates in the cylinder, and the volume in the cylinder changes constantly. When the piston is at the top dead center position, the space between the top of the piston and the inner surface of the cylinder head is called the combustion chamber. This space volume is called combustion chamber volume.

cool.gif The space volume through which the piston moves from top dead center to bottom dead center is called the cylinder displacement. If the engine has several cylinders, the sum of the working volumes of all cylinders is called the engine displacement.

c) When the piston is at the bottom dead center position, the total cylinder volume above the piston crown is called the total cylinder volume.

>>Compression ratio

a) The ratio of total cylinder volume to combustion chamber volume is called compression ratio. The compression ratio indicates the degree to which the gas is compressed in the cylinder when the piston moves from BDC to TDC.

cool.gif The greater the compression ratio, the greater the degree of compression of the gas in the cylinder, the higher the pressure and temperature of the compression end gas, and the greater the power, but too high the compression ratio is prone to detonation.

c) Compression ratio is an important structural parameter of engine. Due to different fuel properties, different types of engines have different requirements for compression ratio. diesel oil The machine requires a large compression ratio, generally between 12-29, while gasoline The compression ratio of the machine is small, between 6-11.

>> SOHC

According to the engine type divided by the number of camshaft positions, SOHC refers to the single overhead camshaft engine, which is applicable to the 2-valve engine.

>> DOHC

DOHC refers to DOHC engine, applicable to multi valve engine. Generally, the engine has two valves per cylinder. In recent years, four valve and five valve engines have been emerging, which undoubtedly opens a way to improve the intake efficiency and power at high engine speeds. This type of engine is suitable for high-speed engines and can properly reduce fuel consumption at high speed.

>> Turbo

It refers to turbocharging, which is called T for short. Generally, 1.8T, 2.8T and other words are marked on the rear of the vehicle. Turbocharging includes single turbocharging and double turbocharging. We usually refer to exhaust turbocharging, which is driven by the exhaust gas to drive the impeller pump Wheel to send more air to the engine, thus increasing the power of the engine and reducing the fuel consumption of the engine.

>> VTEC

Domestically produced Accord The car engine adopts VTEC technology. "VTEC" is the abbreviation of "Variable Valve Timing and Lift Electronic Control System" in English, which means "Variable Valve Timing and Lift Electronic Control System" in Chinese. VTEC is a variable intake valve control technology, which can change the intake volume and improve the engine torque by changing the intake valve opening.

The entire VTEC system is controlled by the engine electronic control unit (ECU), which receives the engine sensor (including speed, intake pressure, vehicle speed, water temperature, etc.), and output corresponding control signals. The rocker arm piston hydraulic system is adjusted through the solenoid valve, so that the engine is controlled by different cams under different speed conditions, affecting the opening and time of the intake valve.

VTEC engine has four valves per cylinder (two inlets and two rows). The difference is the number and control method of cams and rocker arms. It is the first valve control system in the world that can simultaneously control the opening and closing time and lift of valves. adopt computer The controlled valve timing and valve lift system can greatly improve the combustion efficiency and performance of the engine. Honda The company uses VTEC technology in almost all its models, from high-performance sports car S2000 to hybrid electric vehicle INSIGHT.

>>Electronic accelerator technology

The electronic accelerator eliminates the traditional accelerator cable and passes the accelerator pedal sensor The microcomputer controls the throttle valve, which is more sensitive and precise.

>>Multi segment variable intake manifold technology

The length of the intake pipe is controlled by the computer to meet the requirements of large torque at low speed and large power at high speed.

>> F.I.R.E

F. I.R.E means "integrated engine", which is produced in Italy, Brazil, Turkey and other countries, with an annual output of millions of units. It is an economic engine with mature technology and stable performance, widely used in Fiat All kinds of economy cars.

To load on Fiat palio For example, 188A4000 engine of car, engine exhaust 1242ml, and the compression ratio is 9.5 ± 0.2 1. The engine control system ECU is Magneti Marelli? IAW 59F multi-point electronic injection system. With electrostatic ignition, sequential injection, non return fuel supply system and dual oxygen sensor technology, the engine emission level easily exceeds the European No. 2 standard and increases Whole vehicle Security of. This system has the following functions: adjusting injection time, controlling ignition advance angle, controlling radiator electronic fan, controlling and managing idle speed, controlling cold start compensation, self diagnosis and self-learning, and has limp home function.

>> VVT-i

Produced in recent years Toyota Sedan, including the latest Vitz Most are equipped with engines marked "VVT-i". VVT-i， It is the abbreviation of "Variable Valve Timing intake", which means "intelligent variable valve timing". Because the electronic control unit (ECU) is used for control Toyota It has a pleasant Chinese name called "Intelligent Variable Valve Timing System". The system mainly controls the intake valve camshaft and has a small tail "i", which is the English code for "Intake". These are the literal meanings of "VVT-i".

VVT-i is a device that controls the valve timing of the inlet camshaft. It is optimized by adjusting the camshaft angle and valve timing, so as to improve the power performance and fuel economy of the engine in all speed ranges and reduce exhaust emissions. In 2000, Toyota released a new generation of Celica, which further developed the VVT-i engine and created a new generation of VVTL-i engine. It also uses the principle similar to Honda VTEC. Compared with the camshaft on the original VVT-i engine, it has more cams that can switch between different angles. It also uses the "rocker arm" mechanism to determine whether to top the cam at a high angle or a small angle, so as to be "continuous" To change the engine timing, overlap time and "two-stage" lift. VVTL-i combines the continuous variable timing and overlap angle of VVT-i, switches with the camshaft of VTEC, and first achieves the first engine that can be said to be "nearly" perfect, VVT-i is a new engine VVTL-i that can change the valve lift. Sure enough, the performance version of Celica has the strength of more than 100hp per liter. The 1.8-liter version has the super strength of 180hp/7800rpm. It also has a high torque curve and plain performance, 0-96km/hr. It should be said that VVTL-i is Toyota's epoch-making masterpiece.

>> VDE

Variable displacement engine (VDE), ready for installation in Ford The company will produce cars and trucks in the future to further improve the fuel economy of cars. This engine technology is most suitable for multi cylinder engines. For example, for a 12 cylinder engine, after adopting this technology, it is equivalent to installing two independent six cylinder engines. One engine can be operated according to the driving needs, while the other one can be left at idle speed. In this way, the engine's exhaust To reduce fuel consumption.

BMW engine won five awards of "International Engine Year Award"

In the 2001 "International Engine Year Award", BMW engine won 5 of the 12 awards, including the most important "Overall Excellence Award". As a result, BMW became the company with the most awards in this year's selection. In fact, BMW has been the most successful and powerful competitor since the launch of this "Engine Oscar Award".

The winning engines of BMW this year are:

○ The 3.2-liter, 6-cylinder engine equipped with BMW M3, with a power of 252 kW (343 hp) and a maximum torque of 365 Nm, won three awards: "Best New Engine Award", "Best 3.0 to 4.0 liter Engine Award" and "2001 Overall Excellence Award".

○ The 1.8-liter, 4-cylinder engine equipped with the BMW 316ti compact car, equipped with innovative "electronic valve" technology, 85 kW (115 hp), maximum torque 175 Nm, won the "Best 1.4 to 1.8-liter engine award".

○ The 3.0-liter, 6-cylinder engines for BMW 3 series, 5 series, X5 and Z3 cars, with a power of 175 kW (231 hp) and a maximum torque of 300 Nm, won the "Best 2.5-3.0 liter Engine Award".

This award has been launched since 1999 and is held once a year. The jury includes 38 world-class experts from 17 countries. Winning this "Engine Oscar Award" by industry experts reaffirmed the strong strength and competitiveness of BMW's engine.

In this selection, BMW engine not only persuaded the expert judges who are good at being picky, and won five eye-catching awards, but also won favorable comments on engine performance, driving pleasure, fuel consumption and technology improvement.

"VALVETRONIC" is the latest technology developed by BMW and is highly praised as a revolutionary innovation in the field of internal combustion engines. The "electronic valve" technology can greatly reduce fuel consumption and carbon dioxide emissions without affecting vehicle performance.

Volkswagen

Germany public Auto Group developed a 10 cylinder turbocharged direct injection diesel engine (TDI), which the company said was the most powerful diesel engine in the world. This 5-liter engine can produce 230 kW/313 horsepower and the maximum torque is 750 N/m. At present, public The largest diesel engine produced by the Group is 1.9-liter TDI, which can produce 110kW/150hp and is used for Bora series cars.

NISSAN

Nissan The 3.5-litre VQ V6 engine was again rated as the top 10 engine of the year by Ward, and it is the only engine that has been rated as the top 10 engine by ward every year. The mature VQ engine is widely used in Nissan As well as numerous models of Infinite, including Nissan Altima and Maxima cars, 350Z sports power, Nissan Murano multi-purpose vehicles, Quest MPV, Pathfinder multi-purpose vehicles and Infinite I35, G35 and FX35 multi-purpose vehicles in 2004. The 3.5-liter VQ engine selected by Ward is used in the unlimited G35 model. The engine produces 260 horsepower and 260 pounds of torque on a 4-door car, 280 horsepower and 270 pounds of torque on a 2-door coupe.

Audi

AudiA6 engine integrates the latest technologies. On the basis of advanced five valve technology, AudiA6 engine also adopts variable phase technology, variable intake manifold technology, and the most advanced exhaust gas turbocharged engine technology, and matches BOSCH's latest multi ignition oil injection technology, making the engine more powerful, more economical, and less polluting.

BMW

The Japanese Society of Automotive Researchers and Journalists awarded the "RJC 2003 Science and Technology Award" to BMW's "VALVETRONIC". BMW's outstanding technology was chosen because of its innovative automotive engineering, excellent power performance and fuel efficiency. VALVETRONIC is at the forefront of automotive technology in the early 21st century. Valvetronic lacks the design of throttle, just like our nose or lungs are in direct contact with the air when we breathe. After omitting throttle, the engine will be more smooth when entering fresh air, reducing some adhesive force and friction force due to air flow, which will save unnecessary loss when the engine is running! For ordinary cars, when we use the pedal fuel valve, we drive the cable to the throttle switch The depth of the accelerator pedal is controlling the opening or closing degree of the throttle, and what is introduced is the fresh air that will enter the engine combustion chamber for combustion. Therefore, the throttle is controlling the air volume and flow rate of the combustion chamber; However, after replacing the "mechanical" air inlet throttle valve, it is replaced by the "electronic" air inlet throttle valve