with respect to the previous generation BMW 5 Series, the new generation of the BMW 5 Series sedan has a new design, a new chassis system, a new powertrain and a more effective security system. The new BMW 5 Series Sedan a total of four petrol engines and three diesel models, a total of seven displacement models. Where diesel-powered mainly targeted at European markets. It is reported that, in addition to 550i (4.4 L V8 twin turbo) mode will be imported into China outside, 535i (3.0 L R6 turbocharger), 528i (3.0 L R6 naturally aspirated) and 523i (2.5 L R6 naturally aspirated) They will be made in China. As the new BMW 5 Series is the flagship model, the BMW 550i combines a number of new car technology. In order to facilitate readers to understand the model, this paper describes some of the technical highlights of the main models.
First, the engine
FIG 1
BMW 550i car equipped with a displacement of 4.4 L direct injection engine N63 ( 1), V8 structure of FIG, 4 valves per cylinder. The engine full name N63B44O0, the engine control unit model MSD85, using the FlexRay bus. N63 manner engine first turbocharger and a main catalytic converter disposed in the V-region of the engine, by shortening the length and increasing the cross-sectional area of the conduit, the intake, exhaust pressure loss to a minimum, significantly improved dynamic performance . When the engine 1 750 r / min, the maximum torque can be output, and over a wide speed range, a very smooth torque output (FIG. 2). Compared with the 4.8 L N62B48O1 engine used on the BMW X5 xDrive48i, N63 engine displacement is reduced, but there is a huge dynamic performance upgrade.
FIG. 2
Second, the automatic transmission
Figure 3
chassis F07 model BMW 550i cars use by the German company ZF new eight-speed automatic transmission GA8HP70Z (FIG. 3), since the responsiveness of the shifting process significantly increased, since the ratio differenceValue is small, and therefore the higher driving and shifting comfort. A torque converter provided with a second generation of mechanical torsional vibration damper, reducing the ratio of the slide lock-up clutch, the lockup clutch engagement operation range thus can be expanded, whereby the fuel cycle (KV01) oil friction reducing the percentage of ~ 5 6 percentage. EGS transmission electronic control unit integrated in an electronic immobilizer control the start forbidden unit, have a better anti-theft function.
Third, the steering system
Figure 4
in the BMW 550i cars, the Servotronic electronic power steering system as standard, by the integrated ICM chassis control system controls vehicle speed according to the steering assist control. As optional active steering system (FIG. 4), the variable gear ratio steering gear from one side to the other side of the limit position of the working limit position, steering wheel rotation number is reduced to 2 turns. When the vehicle speed is below 60 km / h, variable gear ratio steering front axle and the rear axle side slip angle HSR combined reverse, improve the cornering performance of the vehicle. Increase as the vehicle speed, steering system active steering control policy change, the steering gear ratio becomes larger, the rear wheel side slip angle and the front wheel steering direction becomes the same direction as the direction the vehicle is traveling more stable.
Fourth, the chassis system
Figure 5
[123 ] Figure 6
the car front axle stabilizer increases the hydraulic swing apparatus (FIG. 5), the rear axle by air springs (FIG. 6), which are the steering, driving, braking and damping control systems combination ensures the running stability of the vehicle in the three-dimensional coordinate system (FIG. 7). When a DSC dynamic stability control system, in addition to preventing wheel slip during start and acceleration, the vehicle also recognized in an unstable state, for example, to flick or front-wheel slip outside of the curve, by controlling the engine power and the vehicle wheels brake intervention, so that the vehicle travels along a trajectory reasonable.
Figure 7
DSC dynamic stability control system comprises the following subsystems: anti-lock braking system ABS, EBDSystem EBV, Cornering brake control CBC, the dynamic brake control DBC, automatic stability control system ASC, the engine torque control system of MMR, the engine braking torque control system MSR, the braking torque control system BMR, the yawing moment control system GMR slip control system SDR and dynamic traction control DTC.
cruise control system with braking intervention DCC, allows the vehicle to automatically maintain a safe distance from the vehicle in front. EDC electronic damping control system active roll stability and ARS device integrated in the vertical dynamics management system VDM, vehicle running stability control.
Fifth, passive safety systems
Figure 8
The car crash and the third-generation advanced security module as a passive safety system ACSM airbag central control unit (FIG. 8).
It differs from the previous collision and that the security module using a separate sensor mounting system (FIG. 9). Placed in the middle of the central body sensor, which comprises an internal lateral acceleration sensor and a longitudinal acceleration sensor. Have a lateral acceleration sensor and a longitudinal acceleration of the mass in each B column. Each have a front door for an airbag sensor measuring pressure.
For example a frontal collision, the longitudinal acceleration sensor and a longitudinal acceleration sensor in the center of the sensor in the B-pillar identified higher acceleration values. The system of the acceleration value obtained by the algorithm and the severity of the collision direction of the collision. This information can be calculated by means of trigger timing and sequence of the occupant protection system to be enabled and trigger detonation circuit output stage.
Figure 9
The system also will be a collision signal is supplied to the other control units in the bus network, according to which crash severity perform their work. For example: Open the central lock, enable the hazard warning lights, interior lights turned on, disabling the electric fuel pump, auxiliary heater and turn off the automatic emergency call.
by the security module and the collision Car Access System CAS starting powered via terminal 30B, citedExplosion capacitor is charged by the switching regulator. When a collision, detonating detonation capacitor provides energy. A detonation circuit output stage from the high-voltage power switch and a low-voltage power switch. High-voltage power switch detonated voltage, low-voltage power switch ground. Detonation circuit output stage controlled by a microprocessor. When
a collision accident or a plurality of actuators triggered, ACSM collision stores a record in a non-erasable memory. After the collision into three records, it will store a fault code can not be erased, while prompt replacement and collision safety module.
a vehicle mounted airbag for protecting the head of an occupant’s head. Head airbag extends from the A-pillar to the C pillar, to cover the entire area of the side glass, glass fragments can reduce the damage to the occupant.
blasting seat belt pretensioner when a collision as much as possible to prevent the belt slack occupants pelvis and shoulder area, reinforcing belt restraining effect (FIG. 10).
10
is located on the belt tensioner driver’s seat or front passenger seat. When the front or rear impact and rollover will detonate the belt tensioner. Its working principle is that the safety belt buckle through the piston in a tensioned steel wire and pipe. When the initiator is triggered to generate gas pressure that moves the piston in the tensioning tube by the pull belt buckle is pulled down, so that the seat belt tension.
VI safe battery terminal
11
If the control unit detects a collision and safety to more severe frontal collision, when a side collision or rear impact, the battery terminal will trigger safe, manner subsequently disconnect the battery and the starter blasting, connecting line between the generator (FIG. 11). In this case, although safe battery terminal has been disconnected, but still continued to ensure that all safety-related electrical power supply by, for example, the hazard warning lights, interior lights and the telephone.
VII, the body
12
Since the engine, transmission and suspension systemMechanical vibration system and the like generated torque are acting on the vehicle body, the body must have a high static and dynamic strength, in order to ensure typical BMW driving characteristics. F07 extensive use of multi-phase steel, high strength steel and aluminum into heat (FIG. 12), increases the strength of the vehicle body (FIG. 13).
13
car for the first time the luggage compartment system with two independent full deck lid open, making it both a classic car and the advantages of the wagon (FIG. 14).
14
(CAO Xing lift)