sensor introduce

Oxygen sensors are essential components in engines that use three-way catalytic converters to reduce exhaust pollution. Once the air-fuel ratio of the mixture deviates from the theoretical air-fuel ratio, the three-way catalyst affects CO The purification ability of HC and NOx will sharply decrease. Therefore, an oxygen sensor is installed in the exhaust pipe to detect the concentration of oxygen in the exhaust and send a feedback signal to the ECU. The ECU then controls the increase or decrease of the fuel injection amount of the fuel injector, thereby controlling the air-fuel ratio of the mixture near the theoretical value. In order to achieve high exhaust purification rate and reduce carbon monoxide (CO) in the exhaust, an electronic fuel injection vehicle is equipped The composition of (HC) hydrocarbons and (NOx) nitrogen oxides requires the use of a three-way catalytic converter. However, in order to effectively use a three-way catalytic converter, it is necessary to precisely control the air-fuel ratio so that it always approaches the theoretical air-fuel ratio. The catalytic converter is usually installed between the exhaust manifold and the muffler. Oxygen sensors have a characteristic, It outputs a sudden change in voltage near the theoretical air-fuel ratio (14.7:1). This characteristic is used to detect the concentration of oxygen in the exhaust and feedback it to the computer to control the air-fuel ratio. When the actual air-fuel ratio increases, the concentration of oxygen in the exhaust increases, and the oxygen sensor notifies the ECU of the lean state of the mixture (small electromotive force: 0V). When the air-fuel ratio is lower than the theoretical air-fuel ratio, the concentration of oxygen in the exhaust decreases, The status of the oxygen sensor (high electromotive force: 1 volt) notifies the (ECU) computer The ECU determines whether the air-fuel ratio is low or high based on the difference in electromotive force from the oxygen sensor, and correspondingly controls the duration of fuel injection. However, if there is a malfunction in the oxygen sensor that causes the output electromotive force to be abnormal, The (ECU) computer cannot precisely control the air-fuel ratio. Therefore, the oxygen sensor can also compensate for the error in the air-fuel ratio caused by wear and tear of mechanical and other components of the electronic fuel injection system. It can be said that it is the only "intelligent" sensor in the electronic fuel injection system. The function of the sensor is to determine whether there is excess oxygen in the exhaust after engine combustion, that is, the oxygen content, and convert the oxygen content into a voltage signal to transmit to the engine computer, Enable the engine to achieve closed-loop control with the goal of excessive air factor; Ensure that the three-way catalytic converter has the maximum conversion efficiency for hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOX) in the exhaust, and maximize the conversion and purification of emitted pollutants)

Installation position of oxygen sensor

The installation position of the oxygen sensor is in the exhaust pipe. Generally, the first one is installed before the three-way catalytic converter, and the second one is installed after the three-way catalytic converter. One is a sensor for detecting the combustion situation of the engine, and the other is an oxygen sensor for detecting the three-way catalytic converter. The oxygen sensor is seen to have a screw with a wire on the back of the exhaust pipe. Both oxygen sensors work normally at the same time, transmitting the collected information to the ECU and adjusting and controlling the fuel injection quantity from time to time, Ensure the normal operation of the engine. If the oxygen sensor is damaged, during driving, especially within 40 to 60 miles, the engine can be felt to shake during rapid acceleration. The degree of shaking may vary depending on the vehicle model. Note: The thread size of the oxygen sensor for automobiles is generally M18, and it is recommended to install it with a torque of 45 to 55 Nm. In addition, the exhaust pipe and oxygen sensor threads should be carefully removed, Don't be damaged. It can easily handle high temperature environments. When the oxygen sensor works, the temperature can reach 800 ℃. To prevent the oxygen sensor threads from sintering in high temperature environments, anti jamming agents need to be applied. In addition, the exhaust pipes and oxygen sensors of the vehicle are very hot after driving. To prevent burns, it is necessary to wait for the exhaust pipes to completely cool before proceeding to the next step of operation

BMW 6 Series introduce

The BMW 6 Series is a car specially designed by BMW Germany for sophisticated drivers. It was introduced in 1976 and discontinued in 1989. During this period, its sales reached 86000 units, making it the most successful box car in BMW's history After a 14 year hiatus, BMW decided to revive the 6 Series and once again enter this large luxury sports car market, showcasing the core concept of the BMW 6 Series in GT racing, combining the advantages of sports cars and luxury RVs The previous models of BMW's sporty two door cars have also perfectly achieved this integration. In terms of exterior design, the 6 Series maintains the typical dynamic style of BMW Coupe, with a long hood, low roof lines, and front and side skirts giving the car a dynamic and elegant posture. To distinguish it from other models, the headlights, engine cover, radiator grille, and front air vents have all been redesigned. By introducing new elements such as LED brake lights in the tail light design, in addition to greatly reducing reaction time, the size and brightness can be adjusted according to different environments. The BMW v8 engine provides power for the 6 Series. BMW is known for its advanced technological development, and a series of LED brake lights have been introduced. The application of high-tech projects has maintained BMW's leading position in the automotive industry. The 6 Series has also adopted many advanced scientific research achievements. The new 6 Series has a body length of 4820mm and a width of 1800mm, which is even wider than the 5 Series. Such a large body shape will inevitably increase the weight of the body, and excessive body weight will greatly affect the acceleration and handling of the 6 Series. Therefore, BMW has used a large amount of aluminum alloy and composite materials on the body of the 6 Series, In order to achieve the goal of reducing weight, carbon fiber reinforced plastic materials are 50% lighter than steel and 35% lighter than aluminum, which can effectively reduce the weight of the vehicle body. The rigidity is three times that of other materials in the central control area (10 sheets), and the collision resistance and safety are quite good, which has always been an ideal material for the automotive industry. However, due to the lack of stamping equipment, carbon fiber used to be produced manually. BMW has developed a set of stamping equipment with a self weight of 200 tons and a pressure of 1800 tons, which is the world's first mass-produced carbon fiber roof, and has begun trial use on the new 6 series. The 6 series also uses an overhead display (hud) system that is only available on aircraft, which can directly display some important information. Projected onto the windshield of the car, including navigation direction, speed, and active cruise control display. The core functions related to driving in the car are operated through the i-drive controller and buttons attached to the steering wheel, but the i-drive control button is placed on the right side of the gear lever and requires arm extension to reach. Other secondary functions and comfort equipment control are arranged in a distance that is easily accessible to the other (2) cars and front seat passengers, Very convenient. Users can also choose a panoramic glass roof that is much larger than a regular electric sunroof, allowing more sunlight to enter the luxurious interior of the car. Dynamic driving and active steering systems are optional equipment for the 6 Series, which can greatly eliminate the body roll caused by vehicle turning and increase the comfort of passengers inside the car. The active steering system, on the other hand, changes the steering ratio based on the vehicle speed through a stepper motor. At lower speeds, the steering sensitivity increases, and larger wheel turns can be achieved by turning the steering wheel at a smaller angle. This situation is very useful for drivers driving on urban roads or parking and turning around. As the speed increases, the steering becomes more sensitive. Accurate, ensuring driving stability and comfort. The BMW 6 Series engine is equipped with Dynamic Stability Control (DSC) and Dynamic Traction Control (DTC) systems. In addition, the Driving Dynamics Control (DDC) technology used in the BMW M3 and M5 models is also used in the new 6 Series, which is controlled through a "SPORT" button located on the center console The DDC function can increase the sensitivity of the throttle response, improve acceleration ability, and provide a more direct response to the power assisted steering mechanism, thereby increasing the driving pleasure of the driver. In terms of power, there is also the option to choose a sequential manual transmission (SMG), which can be changed by the paddles on the steering wheel or the gear lever. As for the interior, we have always trusted BMW. The 6 Series adheres to BMW's consistent style, perfectly combining luxury and practicality. The bright colors are more in line with its sporty characteristics, and there are multiple configurations to choose from. As a representative of luxury cars, the BMW 6 Series [2] also has many commendable features. In terms of sound configuration, the new BMW 6 Series is equipped with 8 features. A hi fi sound system with speakers, 9 space seats, and 6 CDs create a home theater effect