Pressure maintenance phase

Pressure maintenance phase

1. Electronic control unit
2. Low-pressure accumulator (reservoir)
3. Recycling pump motor
4. Recycling pump
5. High-pressure accumulator (damping chamber)
6. Brake pump
7. Servo unit
8. Rapid pressure reducing valve
9. Inlet solenoid (A) open (B) closed
10. Outlet solenoid (A) closed (B) open
11. Brake caliper
12. Rpm sensor
13. Phonic wheel
14. Constriction

In this phase the electronic control unit (1) earths the inlet solenoid (9) which closes, while the outlet solenoid (10), not being connected to earth, is already closed.

The hydraulic connection between the brake pump (6) and brake caliper (11) is interrupted (waiting position).

The pressure in the brake caliper (11) is kept constant at the value reached previously, whatever the pressure on the brake pedal.

Even though the braking force maintains a continuous slowing down action, the wheel varies its speed in accordance with the grip on the ground, until the rpm sensor (12) measures a value which is comparable to the reference speed calculated by the electronic control unit (1).

At this point, the control unit passes from the maintenance phase to the pressure increase phase (if the wheel accelerates) or reduction phase (if the wheel is tending to lock).