Development of New Brake Control System With Gear Pump Modulator

In recent years, there has been a growing need for excellent automobile safety. The number of vehicle with active safety systems such as ABS, Brake Assist and VSC (Vehicle Stability Control) is dramatically increasing. A current brake control systems tend to generate activating noise and uncomfortable brake pedal feeling, which they have to restrain its positive use during ordinary braking.

To improve this point, a new brake control system has been developed. This paper introduces the configuration, functions and effects of the system. The new hydraulic modulator adopts a gear pump (trochoid pump) and linear solenoid valves. This allows the modulator to be controlled silently and smoothly. As a result, it becomes possible to apply hydraulic pressure in the normal operating range at any time and a high level of performance is realized.

Several new benefits were added to the current control system. The VSC comes to distribute braking force to the four wheels appropriately not only in the event of sudden change in vehicle behavior but also during ordinary braking. This results in excellent vehicle stability and braking performance at the same time. Furthermore this brake control system provides supplemental brake force even during normal braking. This results in an excellent braking performance and brake pedal feeling. The pre-crash brake assist is the system that increases the deceleration if a crash is judged unavoidable and a driver put on the brake. The new brake system makes it possible to activate the pump in advance thus enhances this effect.