Pressure increase phase

Pressure increase phase

In this phase the solenoid valves of the electrohydraulic control unit are not energised and the pressure in the calipers originates from the pressure exerted on the brake pedal by the driver.

The pressure of the brake fluid at the outlet of the brake pump hose (B) reaches the left front wheel and the right rear wheel through solenoid valves (2) and (4), while from hose (C) it reaches the right front wheel and the left rear wheel through the solenoid valve (3) and the sequential valve (9).

The pressure of the brake fluid crosses the sequential valve (9) because the piston (10), pushed by the spring (13), keeps the valve (14) in the open position; piston (11) does not intervene as both its surfaces are affected by the same pressure.

The braking force increases and as a result the wheels reduce their speed in relation to that of the car (slipping increases), if a rear wheel tends to lock the sensor detects what is happening and the electronic control unit reduces the pressure.

• A. Electronic control unit
• B. Brake pump outlet hose
• C. Brake pump outlet hose

1. Brake pump
2. Solenoid valve for front wheel brake circuit
3. Solenoid valve for front wheel brake circuit
4. Solenoid valve for rear wheel brake circuit
5. Electric recovery pump
6. Accumulators
7. Revolution sensors and phonic wheels for front wheels
8. Revolution sensors and phonic wheels for rear wheels
9. Hydraulic sequential valve
10. Piston
11. Piston
12. Stiff rod connecting pistons
13. Spring
14. Valve