| 摘要 |
1360774 Combined brake booster and modulator BENDIX CORP 1 Feb 1973 5160/73 Heading F2F An integrated brake booster and adaptive braking modulator comprises a piston sliding in a chamber 36 of a housing and defining compartments on either side thereof, an operatoroperated valve 116 controlling communication to one compartment to move the piston which actuates a device for generating brake line pressure, a control unit responsive to the deceleration of at least one braked wheel and an electrically operated valve for communicating pressure fluid to the other compartment to cause reverse piston movement and brake line pressure relief upon occurrence of a skidding condition of the wheel. The chamber 36 is divided into two, each with a piston 44, 46 actuating a further piston 64, 72 via a rod 62, 70 to generate hydraulic pressure in front and rear brake lines respectively, a reservoir being provided in known manner for each further piston. An input rod 140 actuates a seat 130 to first close communication between the right-hand end of the chamber 36 and a return port 15 via passages 136, 138, 142, 144, and then open communication to that chamber end from a pressure source, e.g. an accumulator fed through a charging valve from a steering pump, via a port 12 and passages 122, 138, 136, to move the pistons 44, 46. During normal braking, for each piston 44, 46, a first solenoid valve 108 allows fluid communication between the left-hand end of the chamber 36 and a reservoir via passages 96, 98 and a port 16, and a second solenoid valve 100 blocks communication between the two ends of the chamber 36. A control device upon receipt of a wheel skid signal actuates the solenoid valves 100, 108 to allow communication between the two chamber ends, and to block flow through the port 16, thus equalizing pressures on either side of the pistons 44, 46, causing retraction, and pressure decrease in the associated brake lines. Alternatively, the solenoid 100 controls communication between the left-hand chamber end and an external accumulator. Upon pressure failure, further movement of the rod 140 causes a pivoted castor 148 on a cartridge 118 to engage the pistons 44, 46 to provide mechanical force transmission. Where the booster is fed directly from a steering pump and must allow continued fluid flow to the steering gear, a spool valve is combined with the input rod. This valve allows communication between an input port from the pump and an outlet port to the steering gear when not actuated, and also allowing communication from the right hand chamber end to a return port to a reservoir. Upon actuation, this latter communication is blocked and flow is allowed from the inlet port to the chamber end, with continued flow to the steering gear. |
