Eight sensors on the car

Automobile Nerve: Talking about automobile sensors.

Automobile sensor is the input device of automobile computer system, which converts various working conditions information, such as vehicle speed, various medium temperatures, engine working conditions and so on. , converted into electrical signals and transmitted to the computer, so that the engine is in the best working condition. There are many sensors on the vehicle. When judging the fault of the sensor, we should not only consider the sensor itself, but also consider the whole faulty circuit. Therefore, when looking for faults, besides checking the sensor, we should also check the wiring harness, connectors and related circuits between the sensor and the electronic control unit. Let's take a look at the main sensors on the car.

Air flow sensor

The air flow sensor converts the inhaled air into an electrical signal and sends it to the electronic control unit (ECU) as one of the basic signals for determining fuel injection. According to different measuring principles, it can be divided into rotary vane air flow sensor (Toyota Prievia station wagon), Carmen vortex air flow sensor (Toyota Lexus LS400 car) and hot wire air flow sensor (Nissan Maxima car).

VG30E engine and Volvo B230F engine TJ648 1AQ4) and hot film air flow sensor installed on domestic Tianjin Sanfeng bus. The first two are volume flow type and the last two are mass flow type. At present, hot-wire air flow sensor and hot-film air flow sensor are mainly used.

Intake pressure sensor

The intake pressure sensor can measure the absolute pressure in the intake manifold according to the load state of the engine, and convert it into an electrical signal, which is sent to the computer together with the speed signal as the basis for determining the basic fuel injection quantity of the injector. This kind of pressure sensor is used in domestic Audi 100 car (V6 engine), Santana 2000 car, Beijing Cherokee (25L engine) and Toyota Crown 3.0 car. At present, the semiconductor piezoresistive intake pressure sensor is widely used.

Throttle position sensor

The throttle position sensor is installed on the throttle to detect the opening of the throttle. It is linked with the throttle through the lever mechanism, and then reflects the different working conditions of the engine. This sensor can detect different working conditions of the engine, and then input it into ECU to control different fuel injection quantity. There are three types of throttle position sensors (Santana 2000 and Tianjin Sanfeng Bus), linear variable resistance throttle position sensor (Beijing Cherokee) and comprehensive throttle position sensor (domestic Audi 100 V6 engine).

Crankshaft position sensor

Crankshaft angle sensor, also known as crank angle sensor, is the most important sensor in computer-controlled ignition system. Its function is to detect the top dead center signal, crank angle signal and engine speed signal, and input them into the computer, so that the computer can issue the best ignition time instruction according to the ignition sequence of cylinders. There are three kinds of crankshaft position sensors: electromagnetic pulse crankshaft position sensor, Hall effect crankshaft position sensor (Santana 2000 and Beijing Cherokee) and photoelectric effect crankshaft position sensor. Different types of crankshaft position sensors have different control modes and control accuracy. Crankshaft position sensors are generally installed on one side of crankshaft pulley or sprocket, some are installed at the front end of camshaft, and some are installed on distributor (Santana 2000).

Knock sensor

The knock sensor is installed on the cylinder block of the engine to monitor the knock of the engine at any time. At present, there are * * * vibration modes and non-* * vibration modes.

When it rains, the wipers on the windshield of the cart and the car will move synchronously, and the two wiper blades will swing around the fixed rotating shaft column to scrape off the rain on the windshield, giving the driver an effective field of vision.

The earliest wiper consists of a rocker arm and an arm with a rubber wiper blade, which is manually operated by the driver. Later, in order to see the position clearly, wiper arms were installed on the left and right sides and connected by connecting rods, which became the manual double wiper blade, which is the prototype of today's automobile wiper.

Later wipers used air pressure difference instead of manpower, which was called vacuum wiper. Connect a pipe to the engine, and use the vacuum degree of the engine to drive the piston inside the wiper to push the swing arm to rotate, so that the wiper blade can act. In the early 1940s, electric wipers were installed in cars to replace vacuum wipers. However, until the early 1980s, some trucks and buses in China still used vacuum wipers. Now, all cars use electric wipers.

The wiper seems simple, but the structure is not simple. Wiper assembly includes motor, reducer, four-bar linkage, wiper arm spindle, wiper blade assembly, etc. When the driver presses the switch of the wiper, the motor starts, and the rotation speed of the motor drives the swing arm through the deceleration and torsion of the worm wheel and worm, and the swing arm drives the four-bar mechanism to drive the rotating shaft installed on the front panel to swing left and right, and finally the rotating shaft drives the wiper blade to sweep the windshield.

At present, there are two wiper arms on the car, one motor is generally called "single arm", and each wiper has a motor called "single arm". Some wiper arms are also attached with hoses, which are connected to the scrubber. When the switch is pressed, water will be injected into the windshield. In some mid-to high-end cars, not only the front and rear windshield wipers, but also the headlights have a light rain wiper to remove the dust on the headlights.

When the driver turns off the wiper, the wiper arm often stays in the right position, which hinders the driver's sight. In order to solve this problem, the wiper is equipped with a return switch to control the wiper motor. When the wiper arm stops at a proper position under the windshield, the motor will stop running.

Nowadays, the wipers generally adopt fast gear, slow gear and intermittent control gear. Among them, the intermittent control gear generally uses the charging and discharging functions of the return switch contact of the motor and the resistor and capacitor to make the wiper sweep according to a certain period, that is, each action stops for 2- 12 seconds, which has less interference to the driver. The wipers of some vehicles are also equipped with electronic governors with sensing function, which can automatically adjust the swing speed of the wiper arm according to the amount of rainfall. The wiper arm rotates fast when it rains heavily, slowly when it rains lightly, and stops when it stops raining.

Do you know the seat belt?

The emphasis on automobile safety performance shows the maturity of market and consumption concept. ABS and airbags are almost the standard configuration of new cars, which consumers are familiar with and pay attention to repeatedly when buying a car. However, they do not pay enough attention to the most important safety belt to protect the life safety of drivers and passengers.

The strongest security guarantee

As the basic safeguard equipment of automobile safety, the main function of seat belt is to limit the position of driver or passenger when an accident occurs, to avoid collision injury between people and other parts of the car body, and to reduce the degree of injury to people caused by accidents. According to industry insiders, there is actually a saying in the industry that the protective effect of seat belts is 90% in the event of a collision, and it is 95% after adding airbags. Without the help of seat belts, the 5% efficacy of airbags is hard to say. It is such an important safety device that many people turn a blind eye to it. Drivers and friends who don't wear seat belts can often be seen on the street. They have many reasons, such as being afraid of getting dirty and damaging their clothes, or feeling troublesome.

According to NHTSA, the use of seat belts has reduced deaths and serious injuries by 45%-65%. In the United States, more than 65,438+00,000 drivers save their lives by using seat belts every year. However, there are countless tragedies that ignore the role of seat belts in China. For those who have been rescued from the jaws of death by seat belts, seat belts are definitely the most important equipment in car safety.

Seat belts are divided into advantages and disadvantages.

In recent years, in addition to the traditional inertial fastening seat belts, there are also advanced pre-tightening and restraint seat belts. The so-called pre-tensioned seat belt means that in the event of an accident, the seat belt system can generate a force to pull back the seat belt in addition to the traditional inertia tightening, thus avoiding excessive forward movement or impact and improving the safety of the seat belt. The other is the restraint seat belt, which can further protect people from chest and neck injuries caused by excessive restraint of seat belts in the event of accidents. The design method is that when the seat belt is fastened, when the fastening force reaches a certain level, the seat belt system will loosen slightly, so that the fastening force will not increase again, so that the impact on the chest and the bending force on the neck will not be too great, which is a relatively advanced seat belt protection system.

Judging from the current automobile market, most products still pay enough attention to safety and adopt more advanced seat belt design technology. However, there are other manufacturers whose products still use the traditional inertial fastening seat belts, and some even take advantage of consumers' contempt and shoddy them in order to save costs. Consumers should pay attention to this when choosing products, and carefully ask about the types of seat belts when purchasing vehicles.

However, although the development of technology can improve the coefficient of driving safety, the awareness of safety cannot be created by technology. Consumers should truly establish the awareness of safe driving, no matter what kind of safety equipment, no matter how slight the function of the equipment, it should not be ignored. At least, we are responsible for our own lives.