| 摘要 |
<p>The brake device comprises a master hydraulic cylinder (6) which pumps pressurised fluid into the braking system (3) following the translation of a control rod (2) operated mechanically by the user, and which is disposed, with respect to the control rod, downstream of the vacuum actuator (10) and upstream of the vacuum control valve (25) which is independent of the actuator and is connected thereto by pipes; the control rod (2) is rigid with the piston of the vacuum actuator (10), and the control valve is composed of a hydraulic actuator (28) controlled by the pressure in the braking system and a second pneumatic actuator (26), the chambers of which are connected to those of the vacuum actuator to counterbalance the thrust exerted by the hydraulic actuator on a spool (38) arranged to selectively connect the vacuum actuator (10) to a vacuum source or to atmosphere.</p> |
