Application and Development of High-tech in Domestic Passenger Cars

With the rapid development of modern science and technology, especially electronics and information technology, various technologies are continuously updated, and the development of automotive technology is changing with each passing day. The wide application of high-tech on domestic passenger cars has greatly increased the technological content, technical level and quality level of domestic passenger cars, which has not only narrowed the gap with the world's advanced passenger cars, but also gradually surpassed the advanced level of world passenger cars.

Domestic passenger cars have experienced more than 40 years of development. In particular, since the reform and opening up in the past 20 years, bus companies have adopted advanced technologies, and have used joint ventures and cooperative methods to digest and attract international passenger car manufacturing technologies, processes, and management models. They have gradually independently developed high-, middle-, low-end, and medium-sized schools that suit national conditions. Small passenger cars have formed a complete product system with many varieties and series, occupying almost all the passenger car markets in China; domestic passenger cars have also been exported in bulk and beaten the international passenger car market. Domestic passenger cars have achieved such remarkable achievements. The contribution of science and technology is enormous. The wide application of new technologies, new materials, new processes, and new equipment has made domestic passenger cars. The comprehensiveness of technical, economical, reliability, and safety has been significantly improved.

At present, the high and new technologies widely used in domestic passenger cars mainly include the following 11 new technologies and new devices.

First, electronically controlled gasoline injection system

Electronically controlled gasoline injection system has the advantage of achieving high-precision air, fuel ratio control. The multi-point sequential injection method is used to separately inject fuel into the intake ports of each cylinder. The variation of the air-fuel ratio of each cylinder is very small, and the engine can work under a more lean mixture. The closed-loop control of the oxygen sensor can further improve the air-fuel ratio control accuracy; When air temperature and pressure change in the running area of ​​the automobile, as well as the transient conditions such as start-up, warm-up, and acceleration, the air-fuel ratio can be corrected and supplemented in time, and the oil can be automatically shut off during deceleration, and the idle speed control system can be used to make various working conditions possible. Get the best air-fuel ratio. There is no mechanical drive problem in the system, and each device can be distributed, so installation on the engine is not limited. When using the multi-point injection method, the intake line can be rationally designed according to the best inflation efficiency, and the inertial pressure increase effect of the intake air can be fully utilized to increase the output power of the engine. Therefore, the gasoline engine with electronically controlled gasoline injection system has significantly improved overall performance. Compared with the traditional carburetor engine, the engine power of the electronically controlled gasoline injection system is increased by 5% to 10%, the fuel consumption is reduced by 5% to 10%, and the emission of harmful substances is reduced by more than 20%; due to the torque performance Improvement, rapid response, rapid acceleration of vehicle performance, easier start-up of cold vehicles, and quicker warm-up, can well meet the current society's requirements for reducing emissions, reducing consumption, increasing power, and improving driving performance.

The electronically controlled gasoline injection system consists of three major systems: intake, fuel, and electronic control. The main components include ECU electronic control unit, air flow meter, intake pipe pressure sensor, fuel meter, fuel injector, fuel pressure regulator, throttle valve and so on.

Second, electronic control diesel injection system

Diesel engine electronic control technology and gasoline electrical control technology are basically similar, the entire system is composed of sensors, electronic control unit ECU and actuators, and diesel engine electronic control technology is the key technology in diesel injection electronic control actuator.

The control principle of the electronically controlled diesel injection system is that through the above three systems, the appropriate amount of fuel injected by the high-pressure fuel injection nozzle is injected into the diesel combustion chamber in an appropriate space at an appropriate time to form the best fuel. Advantages of mixing and combustion with air, achieving diesel engines in terms of power, torque, speed, fuel consumption, idle speed, noise, emissions and other requirements. Through sensors such as rotation speed, fuel injection time, vehicle speed, intake pressure, intake air temperature, fuel temperature, cooling water temperature, etc., ECU compares with the previously stored parameters in the ECU according to the newly transmitted parameters, according to their optimal values ​​or The calculated target value sends the instruction to the actuator. The actuator controls the injection quantity and timing of the injection according to the ECU command so that the engine is in the best working condition.

Third, the engine exhaust turbocharger

The engine exhaust turbocharger uses the pressure and energy of the exhaust gas emitted by the engine to propel the turbine to rotate, and drives the impeller compressor at the other end of the turbine to rotate the impeller at a high speed, forcing the air into the engine cylinder to increase the intake pressure and pressure. Gas volume, while the fuel injection volume will increase accordingly. Increase engine power by 30% to 40% compared to naturally aspirated engine power. As the combustion is complete, the mechanical efficiency is improved, the fuel consumption is reduced, the exhaust smoke is greatly reduced, harmful substances such as CO and CH in the exhaust gas are significantly reduced, and the degree of air pollution is reduced, and engine emissions can reach Euro II and Euro III standards.

At the same time, the exhaust gas turbocharger has the effect of increasing the power without increasing the cylinder bore, greatly reducing the geometrical dimensions and unit power weight of the engine, saving raw materials and reducing production costs. Therefore, exhaust gas turbochargers are widely used in large and medium-sized passenger cars.

Engine exhaust turbochargers are often operated at high speeds and high temperatures. After the engine is started, it should be allowed to idle for a few minutes, especially when the weather is cold in winter. After the engine is running for a long time, it should not be turned off immediately to ensure sufficient lubricant. Lubricate the supercharger's rotor bearings to prevent failure or damage.

Fourth, electronically controlled automatic transmission

The electronically controlled automatic transmission can realize the functions of automatically controlling the starting of the car, selecting and shifting gears, realizing the engine working in the best working conditions, greatly reducing the labor intensity of the driver, and improving the mobility and off-roadability of the vehicle.

Electronically controlled automatic transmission consists of throttle position sensor, wheel speed sensor, idle speed sensor, wheel speed sensor, water temperature sensor, idle speed sensor, neutral switch, hydraulic regulator, solenoid valve, transmission information, brake information, control information and electricity The controller ECU is composed of the controller ECU. According to the vehicle and engine operating conditions and the driver's requirements, various information is detected by the switch and the sensor and input into the electronic controller. The electronic controller issues instructions according to the stored program to control the automatic transmission. , Make the production actuator drive transmission system speed.

Fifth, ABS anti-lock device

The anti-lock brake system (Anti-lockBrakeSystem) is abbreviated as ABS. It adopts advanced electronic controllers and pressure regulators. It automatically adjusts according to the parameters such as the speed of the vehicle and the adhesion coefficient of the road surface in the process of driving and braking. The brake line pressure controls the slip ratio of the wheel in the optimal zone, so that the vehicle can obtain the best braking effect and braking stability. Braking at high speeds and on slippery roads can reduce braking distances, and can reduce tire wear and wheel rounding. When the vehicle slides sideways, the vehicle keeps the straight line decelerating while braking.

Its working principle is that when the wheel is about to be locked, the brake is released slightly, and then it quickly hugged and released again. The process can be adjusted several times per second, referred to as "electronic fast point brake". . When the driver depresses the brake pedal of the vehicle, the controller in the electronic regulator determines the wheel's movement state based on the sensor signal and locks it. The regulator controls the brake cylinders on the wheels to generate pressure, pressure, and pressure reduction actions to achieve the purpose of anti-lock braking, eliminate side slipping and tail flicking of the vehicle, and greatly improve the driving safety of the vehicle. .

The main components of ABS are composed of electronic controllers (ECUs), wheel speed sensors, brake pressure regulators, pressure regulating solenoid valves, fuel tanks, energy storage devices, and alarm lights.

Sixth, automotive anti-skid control system (ASR)

The ASR is an extension of the anti-lock ABS device. Its role is to prevent the drive wheels from slipping. When the vehicle starts or accelerates, it controls the adhesion of the drive wheels according to the conditions of the road surface and the wheel speed to improve stability. Traction and handling.

The ASR principle is similar to ABS in that it can share wheel speed sensors simultaneously. ASR electronics, controllers, and specialized actuators, when driving the wheel, transmit the collected signals to the controller through the wheel speed sensor. After processing, the speed and acceleration of each drive wheel are obtained. At the same time, when the vehicle speed is less than the speed limit (30-40km/h), the slip ratio of the drive wheel is further calculated and judged. If the slip ratio of a certain driving wheel exceeds the limit value, the controller instructs the actuator of the ASR to limit the slippage of the driving wheel until the slip ratio is within the range of the demand.

VII. Chassis Centralized Lubrication System

In the passenger car chassis, the traditional way of lubrication is to rely on manpower to add grease to each friction pair, and the working efficiency is low. If the routine maintenance is not normal, it is difficult to ensure a good lubrication state, causing failure and affecting normal operations. Chassis centralized lubrication system solves the above problems and deficiencies, greatly improving work efficiency, automatically lubricates all parts that need to be lubricated on time, and improves the safety of the vehicle. It is simple in structure, easy to install, and reduces the cost of routine maintenance.

Centralized automatic lubrication system is a closed system that regularly and quantitatively fills grease to various frictional parts to minimize the wear of the friction pair and maintains good lubrication condition for each friction pair, thereby prolonging its service life. , improve vehicle operating efficiency. It is mainly composed of a microcomputer controller (ECU), an oil storage tank, an oil pump, and a closed oil supply pipe. Usually should pay attention to checking the working conditions of the above components, whether there is oil leaking pipeline, the oil level of the oil in the oil tank is between the normal range MAX (highest) and MIN (lowest) position.

Eight, air conditioning system

With the increase in the level of passenger spending, senior limousine passengers have deployed air-conditioning systems. It mainly includes refrigeration and heating devices, as well as ventilation, humidification and air purification devices.

Stand-alone fuel air heating heating equipment. The working principle is: after the external combustion air and the fuel from the passenger vehicle fuel tank are fully mixed, they are ignited in the combustion chamber. Fresh air is heated and blown into the vehicle compartment to achieve the purpose of heating and heating. Its main components consist of oil pump controllers, fans, flame sensors, ceramic glow plugs, and heat exchangers. In addition, there is a waste heat type, plumbing heating system.

Non-independent refrigeration system. Its working principle is that the engine output power, through the belt drive air conditioning compressor operation, compression refrigerant, liquid gas conversion, the evaporator to the maximum cooling output cooling, the fan and the pipeline sent to the passenger air above the seat to send Vent, to achieve the purpose of refrigeration. Its main components consist of a compressor, an evaporator, a condenser, a temperature sensor, an electronic controller, a fan, and the like. In addition, there is a stand-alone air-conditioning refrigeration system.

At present, in order to increase the relative humidity of the air in the vehicle, a humidifier is installed; an air ventilation device is installed to suck fresh air from outside the vehicle; and the air is cleaned more cleanly by removing the dust, odor and bacteria in the air inside the vehicle. Install disinfection and purification equipment.

Nine, car navigation system

The car navigation system uses the advanced global positioning system (GPS) positioning technology, combines the geographic information (GIS) system database provided by the vehicle terminal and traffic information network, so that the driving vehicle has the function of real-time automatic positioning and navigation. The main functions include vehicle tracking and positioning, travel route planning and navigation, enquiry along the way and destination information, traffic management and emergency rescue. The system is mainly composed of GPS satellite navigation and positioning system and vehicle-mounted and road traffic information systems. At this stage, there are still a limited number of GPS positioning systems installed on domestic passenger cars.

X. Car Drive Recorder

The car driving recorder plays an important role in ensuring the safety of vehicle driving, analyzing and identifying traffic accidents, curbing fatigue driving, speeding violation, and constraining the bad driving behavior of drivers. It is an ideal technology product that can prevent and reduce accidents, implement effective monitoring and scientific management of motor vehicles, and provide reliable basis for the handling of traffic accidents. It can store various movement status and driving speed data of the car in the recorder, and can print out all the recorded contents, providing real and reliable scientific data. It is mainly composed of a host computer, display, speed sensor, micro printer, and data analysis software. Now domestic passenger cars. Vehicles equipped with car tachographs are gradually increasing.

Eleventh, eddy current retarder

Eddy current retarder is a new type of automobile deceleration device based on the principle of electromagnetic mechanics, commonly known as "the second brake of the car." Eddy current retarder is a frictionless, no wearing part of the deceleration device. Its application solves the problems caused by the deceleration of the car, such as large vibration, poor stability, tail flick, lost balance of the entire vehicle, and failure of the brake, which greatly improves the safety and comfort of the vehicle and prolongs the use of the brake system and tires. life.

The working principle of the eddy current retarder is that the current passes through the coil windings to generate a magnetic field, and the rotor (impeller) and the stator (coil plate) rotate at a relatively high speed. The rotor cuts magnetic lines of force to create eddy currents. Powerful magnetic moments act on the drive shaft, allowing the car to slow down quickly. The rotor (impeller) can also play a cooling role.

The general eddy current retarder mainly consists of the main body and the electrical control system flow. The main body is composed of impellers, coil fixing plates, brackets, flanges and other components; the electrical control system consists of distribution boxes, handle switches, and coils.

Different models can be selected according to the needs of the appropriate installation location. Different types and sizes of eddy current retarders can be installed between transmission shafts, gearboxes, and drive axles.

When using the eddy current retarder, pay attention to the following points: 1 According to the speed of the car when the stall operation, need to increase the stall, the use of progressive gearshift operation. When the speed of the vehicle slows to the required speed, the handle switch is immediately returned to the neutral position. 2 When the vehicle speed is 20km/h, the retarder must be turned off. 3 Do not use the retarder 10 minutes before parking. 4 When the deceleration time exceeds 30s, the retarder will automatically stop working, and the handle switch should be restored to the neutral position. Before restarting.5 On ice-snow, slippery roads, it is necessary to change the gear gradually, and the brake can't exceed the limit of adhesion of the tire.If there is any abnormality, immediately return to the original position, if necessary, turn off the retarder power. When going downhill over long distances, the slope, camber, and proper gear position should be selected.