Following the launch of the CAN-based ESP 9 (electronic stability program) in passenger cars, Bosch (Germany) is introducing the ESP 9TE for light commercial vehicles. The already manufactured ESP 9LE has been optimized for the types of van commonly found in Europe, which have high pressures in their main brake cylinders.
WITH ESP 9TE, A NUMBER OF ADDITIONAL ESP FUNCTIONS will be available for the weightier segment of light commercial vehicles weighing up to 8 t. These functions include brake prefill by bringing the brake pads into position, automatic braking in hazardous situations, and safety interventions on steep gradients. The company is planning to start series production in 2014. “With the new varieties of Bosch ESP, significant improvements to the safety of light commercial vehicles can be made,” said Gerhard Steiger, president of the Bosch Chassis Systems Control division.
Vans, sport utility vehicles, and pick-up trucks place greater demands on the brake system due to features such as gross vehicle weight, wheel base, and larger brake calipers. Both the ESP 9TE and ESP 9LE have been optimized to meet those demands. Both allow the kind of additional functions, including comfort functions, that are common in the passenger-car segment. In addition, automakers can offer the kind of stability support required specifically for vans. The load adaptive control function, for example, adapts the interventions by the ABS, TCS, and ESP active safety systems to the respective load status, while roll-over mitigation acts to check roll-over by braking the individual wheels appropriately and reducing torque.
ESP 9TE is designed above all for the U.S. market. While automakers in Europe tend to rely on compressed air brakes once vehicles exceed a weight of 6 t to 7 t, pick-up trucks in the U.S. tend to be braked by larger brake calipers. For such calipers, the ESP system requires a more dynamic active build-up of pressure, with a high delivery rate. What matters here are pump housing and valves optimized for flow, asymmetric pump elements, a powerful motor, and larger storage chambers. Using the introduced system, there is no need for the pre-charge components that were often necessary in the past. Compared with standard ESP systems, ESP 9LE is equipped with a motor delivering greater torque, special valves, and larger storage chambers for the high pressures (up to 330 bar) typically found in the main brake cylinders of vans. In addition, it can support recuperative braking in hybrid vehicles, allowing the braking effect of the electric motor to be synchronized with conventional braking action.
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