摘要:
In brake systems with a large boosting factor, relatively high pressures in the tandem master cylinder during an anti-lock control operation caused by start-up of a pump are prevented by an adjusting member which is controlled in response to the wheel braking pressure, to act upon a pressure-reducing valve inserted upstream of a power booster, so as to limit the booster pressure.
摘要:
In an anti-lock brake system, a differential pressure limiter (8) is connected in front of the inlet valve (6). This causes a defined pressure gradient to always prevail at the inlet valve (6), what appreciably reduces the noise emission of the valve during an anti-lock braking operation. Since the inlet valve (6) has a slight throttling effect in its opened position, it may occur that on brake operation with cold brake fluid a pressure gradient is generated at the inlet valve (6) which results in the differential pressure limiter closing. It is therefore suggested to arrange a bimetal spring (20) in parallel to the control spring (15) of the differential pressure limiter (8), which bimetal spring expands at low temperatures and cases a force in addition to the spring force of the control spring (15) to act on the control piston.
摘要:
In an anti-lock brake control system having a vacuum brake power booster and a tandem master cylinder, in which the brake pedal is controlled to be positioned forwardly of the initial return position during the anti-lock control mode. This is achieved by variation of the rate of delivery of an auxiliary pump as by switching the pump motor on and off by a switch actuated by the diaphragm of the power booster to provide a signal of the pedal position at the start of an anti-lock control phase. Various switching arrangements described include a Bowden-cable pulled by the diaphragm, a mechanical or an optical switch actuated by the rolling lip of the diaphragm, or an approach switch detecting the approach of the diaphragm and cam-assembly. The core (53) of the Bowden cable (54) is connected with the diaphragm plate (52) of the vacuum brake power booster. The core (53) moves the trigger cam (64). The switch (18) is actuated by the movement of the trigger cam (64).
摘要:
To control the pressure at the outlet of a pump and to position the pedal during a brake slip control action, an additional arrangement is provided to an existing master brake cylinder which arrangement comprises a transmission piston (5) as well as a shut-off valve (30). The closure member of the shut-off valve is loaded by way of a valve piston (28) and by the pressure in the brake line (18') in opposition to the pressure at the outlet of the pump. The valve closure member is thus pressure-balanced so that no forces are transmitted onto the tappet (37). Therefore, the ramp (40) at the transition piston (5) need not be separately hardened during the manufacturing process.
摘要:
The invention discloses a brake pressure regulator for anti-locking control and for traction skid control of automotive vehicles. The regulator comprises a master cylinder, a hydraulic brake force booster, an electronic controller which, based on sensor signals, at the output thereof, renders available variable signals according to a control algorithm to switch electromagnetic valves associated with the wheel cylinders, a pressure fluid source and a reservoir. A valve aggregate insures the adaptation of the pressure level from the pressure fluid source to the operating pressure desired for the TSC-mode and the ALC-mode. Moreover, the valve aggregate, with the brake applied, turns off the TSC-mode. The valve aggregate comprises at least one plunger/ball arrangement serving a the closing and/or control member. The advantages involved with this brake pressure regulator reside in the automatic pressure level regulation and the automatic turn-off of the TSC-mode. Moreover, the inlet and blocking valves otherwise required for the TSC-mode are eliminated. Advantageous use is made of ball/seat valves in the present invention.
摘要:
A system is disclosed including valves which are opened or closed dependent upon the position of master cylinder pistons. Upon commencement of slip control, pumps supply fluid either into the slip control cycle or into the working chambers depending upon the position of the pistons. As a result, the pistons are reset until a pin of the valve reaches a ramp or cam and the valve opens. When the valve is open at the start of the control, the pumps first supply fluid into the open cycle, and the pressure fluid discharged from the wheel brakes for slip control is replenished out of the pressure chambers until the pin contacts the ramp or cam whereby pressure fluid supply from the pumps takes place.
摘要:
An anti-lock hydraulic brake system which includes a brake pressure generator composed of a master cylinder, a brake power booster inserted upstream thereof and a pressure modulator interposed between the master cylinder and the brake power booster. A resetting unit is formed by supplementing the pressure modulator with a valve assembly which connects a resetting chamber of the pressure modulator to either a pressure-compensating reservoir or an auxiliary-pressure source. The braking pressure in the wheel brakes is controlled, according to a time-multiplex method, by wheel valves inserted into the pressure-fluid conduits and by the pressure modulator. In order to check the operability of the brake and of the anti-lock control system, a pressure switch is connected to the pressure modulator and a test circuit is provided which, at predetermined points of time, initiates a test cycle, actuates the valves and compares the valves' operation with the reaction of the pressure switch.
摘要:
A hydraulic brake system for automotive vehicles has a master brake cylinder (1) operable by a brake pedal, wheel brakes (VL, HR, VR, HL) being connected to said master brake cylinder via brake lines (11, 12), and a hydraulic power booster (22) supplied by a pressure medium source (42) and connected between the brake pedal and the master brake cylinder (1) so as to boost the actuating force. The booster has a booster piston (27) in a booster chamber (28) and the pressurization of said booster piston is controllable by the brake pedal via a control piston (30). For controlling the brake system by means of a brake slip control device the connection from the brake lines (11, 12) to the wheel brakes can be blocked by solenoid valves (13-16). The booster piston (27) is connected with a resetting piston which, for pushing the booster piston back into its rest position, is pressurizable via a resetting valve (46, 53) controllable by the brake slip control device. For brake slip control the master cylinder ( 1) is actuatable intermittently by means of a drive piston (39), with the booster piston moved back. The actuating movement of said drive piston is controllable by the brake slip control device via solenoid valves (48, 55). A traction slip control device can connect the cylinder chamber (38) of the drive piston (39) with the pressure medium source (42) via a solenoid valve (50) and a pressure reducing valve (51) and also with the unpressurized reservoir (44) via a solenoid valve (48).
摘要:
A hydraulic brake system includes a hydraulic power booster (11) and a master cylinder (12) connected downstream of the power booster (11). The pressure chamber (21) of the power booster (11) is pressurized by an auxiliary pressure which is dependent on the position of a pedal-actuated brake valve (19). A fast-fill cylinder (40) is can be pressurized by the dynamic pressure and with its aid the working chamber (16) of the master cylinder (12) can be supplied with additional pressure fluid in the initial phase of braking. The chamber (48) between the two piston steps (57, 58) of the fast-fill cylinder connects to the unpressurized supply reservoir (3) by way of a valve assembly (51) for synchronizing the movements of the master cylinder piston (43) and of the stepped piston (45) of the fast-fill cylinder (40). The valve assembly (51) is furnished with the wheel cylinder pressure as a control variable.
摘要:
A hydraulic skid-controlled brake system comprising a master cylinder (2) pressurizable by a hydraulic force booster (1). The master cylinder piston (5) is provided as a stepped piston, with the small piston step (14) cooperating with the booster piston (4) traversing an annular chamber (19). The large piston step (15) plunges into the annular chamber (19). When the brakes are applied, the pressure fluid flows from a brake circuit (22, 31) into the annular chamber (19) by way of a first pressure fluid conduit (18, 21) and in which a blocking valve (26) is provided. By way of a second pressure fluid conduit (33, 34, 47, 36) the pressure fluid flows from the annular chamber (19) into an intake reservoir (11) in which a current control valve including a blocking slide (35) is provided. The connection (33) to the annular chamber (19), in the brake releasing position, is closed by the large step (15) of the master cylinder piston (5 ). A defined resetting movement of the master cylinder piston (5), during the skid control, is achieved by blocking the two pressure fluid conduits.