Abstract: A hydraulically operated braking system including a hydraulic pump operated by an electric motor, and a motor control device connected to the electric motor and controlling an electric current to be applied to the electric motor, by pulse width modulation, such that a PWM frequency at which the electric current is controlled by the pulse width modulation is set at a relatively high value higher than an upper audibility limit while the braking system is placed in a normal braking operation during which the generation of an operating noise of the braking system is not allowed, and at a relatively low value not higher than the upper audibility limit while the braking system is placed in a noise-tolerable braking operation during which the generation of the operating noise is allowed.

Abstract: Braking system including a master cylinder having at least two pressurizing pistons partially defining at least two mutually isolated pressurizing chambers, and wherein a working fluid in each pressurizing chamber is pressurized by an advancing movement of the corresponding pressurizing piston, a hydraulically operable brake cylinder for activating a brake, and a valve device having a first state in which the pressurized fluid is delivered from two pressurizing chambers of the at least two pressurizing chambers to the brake cylinder, and a second state in which the pressurized fluid is delivered from only one of the two pressurizing chambers.

Abstract: A brake fluid pressure control device including a power pump provided in a fluid supply line for discharging fluid into the main fluid line. An on-off valve is provided in the main fluid line upstream of the point at which the outlet circuit of the pump merges with the main fluid line. A fluid reservoir is provided in the fluid supply line upstream of the pump. For automatic braking, a changeover valve is changed over to supply fluid in the first chamber into the inlet port of the pump. When the automatic braking is off, the inlet and outlet ports of the pump are connected to the second and first chambers of the reservoir, respectively, to supply fluid into the first chamber.

Abstract: A brake force control apparatus which can always accurately generate a brake force confirming to a driver's intention is provided. The brake force control apparatus performs brake assist control for supplying an increased brake fluid pressure which is greater than that generated in a regular brake operation to a wheel cylinder of a vehicle when an emergency brake operation is performed by a driver. A deceleration of the vehicle is detected. Additionally, a difference between a target deceleration which is to be generated during execution of the brake assist control and the deceleration is detected. A brake fluid pressure which is supplied to the wheel cylinder during execution of the brake assist control is controlled based on the difference.

Abstract: A brake control apparatus is provided with a simulator for applying a biasing force to a manually operated braking member of a vehicle in response to braking operation. A sensor detects conditions of the vehicle including a braking condition of the vehicle. A first biasing device applies a first biasing force to the manually operated braking member in response to braking operation, and a second biasing device applies a second biasing force, as well. Only one of the first and second biasing devices applies the biasing force to the manually operated braking member when a predetermined condition is detected by the sensor, while both of the first and second biasing devices apply the biasing forces in the normal braking operation.

Abstract: A multi-way pressure control valve for an electromagnetically actuatable multi-way control valve for slip-controlled hydraulic automotive vehicle brake systems, for providing a flow connection between at least one wheel brake and a high-pressure source or a low-pressure accumulator.

Abstract: A method of controlling a pump in a brake system of a motor vehicle, in particular an electrohydraulic brake system, is described, where the pump can be controlled by a pump motor either uncycled or continuously and cycled, where the period of uncycled control and/or an initial pulse-pulse pause ratio at the start of cycled control can be varied as a function of a voltage applied to the pump motor before and/or at the start of and/or during uncycled control and/or as a function of an on-board voltage of the motor vehicle determined before and/or at the start of and/or during uncycled control.

Abstract: The present invention is directed to a brake control system, which includes wheel brake cylinders, a master cylinder, a reservoir communicated with the wheel brake cylinders, normally open solenoid valves disposed between the master cylinder and the wheel brake cylinders, respectively, normally closed solenoid valves disposed between the wheel brake cylinders and the reservoir, respectively, a hydraulic pump for supplying the brake fluid to a passage for connecting the master cylinder with the normally open valves, and an automatically pressurizing device (e.g., a vacuum booster with a changeover valve) which is provided for advancing the master piston irrespective of operation of the pump and the brake pedal to generate hydraulic braking pressure from the master cylinder.

Abstract: A hydraulic brake system for a vehicle for braking the vehicle by brake pedal actuation and/or automatic braking. A pump is provided which has a suction connection that communicates with a supply container for a pressure fluid and a pressure connection for aspirating pressure fluid from the supply container and pumping the fluid to a connection of a master cylinder. A brake circuit of the vehicle brake system is connected with vehicle wheels associated with wheel brake cylinders and with valve assemblies for brake pressure modulation and is connected to the connection of the master cylinder. A valve pressure is also provided between a pressure chamber that communicates with the connection of the master cylinder and the supply container for pressure fluid.

Abstract: When it has been determined that a termination condition of brake TRC control has been fulfilled, SM valves 50FL and 50FR and a motor 80 are continuously placed in an ON state, and along with this, SR valves 70FL and 70FR are switched off, and furthermore holding valves 46FL and 46FR and pressure-reducing valves 48FL and 48FR of driving wheels are changed from an on-off switching state to an ON state, and termination control is initiated. Because of this, high-pressure brake fluid on the wheel-cylinder 2FL and 2FR side is expelled via the pressure-reducing valves 48FL and 48FR by drive of the motor 80. Consequently, high-pressure brake fluid can rapidly be expelled immediately after brake TRC control, and along with this, oil-shock noise can be alleviated.

Abstract: A pump, electromagnetically operable valves and at least one low-pressure accumulator are arranged in a valve block. The valve actuators are disposed in front of a base of the valve block opposite to an electric motor which drives the pump. The housing of the low-pressure accumulator is formed of an add-on piece which is deepdrawn from sheet metal in a bowl-type configuration. The edge of the add-on piece is attached in the mouth of a blind-end bore in the valve block. The add-on piece projects beyond the and has roughly the same height as the actuators of the valves. The actuators and the add-on pieces are covered by a housing cap on the valve block which protects them against environmental influences. The arrangement is extremely compact and permits achieving a relatively small and, thus, light-weight valve block.

Abstract: A brake hydraulic control device for use in a vehicle, includes: a master cylinder with a first reservoir attached thereto; a second reservoir different from the first reservoir; a drive wheel control valve unit switching communication and cut-off between a drive wheel brake and the master cylinder as well as communication and cut-off between the drive wheel brake and the second reservoir; a driven wheel control valve unit switching communication and cut-off between a driven wheel brake and the master cylinder as well as communication and cut-off between the driven wheel brake and the second reservoir; and a pump having a discharge port connected between the drive wheel control valve unit and the drive wheel brake, and a suction port connected to the master cylinder through an open/close switch valve and to the said second reservoir.

Abstract: Improved control for a hydraulic system pump motor useful in automotive braking applications, particularly in motor-based ABS, includes a routine for controlling a pump motor so that it is operated in a manner that is not disturbing to automotive vehicle occupants. In particular, the control routine of the present invention controls pump motor operation after an ABS braking event so that the motor is running only when the motor noise is masked by the pulsing of the ABS solenoids or after driver braking pressure is released from the master cylinder. In this way, the amount of objectionable noise transmitted to the automotive vehicle occupants is reduced, while important ABS pump functions, such as the draining of the accumulators following an ABS braking event, are facilitated.

Abstract: In a rotary pump, an outer rotor and an inner rotor are assembled in a casing such that, when a clearance between an inner teeth portion of the outer rotor and an outer teeth portion of the inner rotor is substantially nullified at a first closed gap portion having a maximum volume formed between the inner teeth portion and the outer teeth portion, a clearance between the outer rotor and the casing on a side of the first closed gap portion and a clearance between the outer rotor and the casing on a side of a second closed gap portion having a minimum volume, become substantially an equivalent interval. As a result, the outer rotor and the casing can be brought into contact with each other on the side of the second closed gap portion rather than the central axis of the inner rotor. Even in a high pressure discharge operation, the outer rotor is not locked by being squeezed between the inner rotor and the casing.

Abstract: A hydraulic brake apparatus for a vehicle includes a first hydraulic passage for supplying pressurized brake fluid from a master cylinder to wheel brakes without passing through a hydraulic pump, a first opening and closing electromagnetic valve interposed in the first hydraulic passage for opening and closing the first hydraulic passage, a second hydraulic passage for supplying brake fluid from the master cylinder to the suction side of the hydraulic pump, and a second opening and closing electromagnetic valve interposed in the second hydraulic passage for opening and closing the second hydraulic passage. A passage cross sectional adjusting valve is interposed in the second hydraulic passage and decreases the passage cross sectional area of the second hydraulic passage to suppress the transmission of a hydraulic pulsation generated in a suction side of the hydraulic pump to the master cylinder when the brake pedal is depressed.

Abstract: A hydraulic Control unit of a vehicular brake system includes a housing having a bore formed therein. A normally closed solenoid valve is retained in the bore of the housing. The solenoid valve includes a primary valve and a pilot valve, wherein a cross section of the primary valve is greater that a cross section of the pilot valve. A spring cooperates with the pilot valve so that the pilot valve is open when the primary valve is open.

Abstract: A method and device for controlling a braking system of a motor vehicle in open loop, in which the wheel-brake pressure in the individual wheel brakes is adjusted via closed pressure-control loops. Different secondary braking operations are initiated depending on the fault condition. The faults are detected on the basis of a model which takes into account the prevailing operating state of the braking system.

Abstract: A method and an apparatus for controlling a brake system, the brake pressure of at least one wheel brake being controlled electrically as a function of at least the braking request of the driver. The brake system includes a high-pressure reservoir, whose pressure is detected and taken into consideration in controlling the brake system. In case of failure of the reservoir pressure detection system, the reservoir pressure is estimated on the basis of a model, and the estimated reservoir pressure is taken into consideration in controlling the brake system.

Abstract: A method and device for estimating pressure changes within a hydraulic system having a first reservoir and at least one second reservoir connected to the first reservoir via valves, including the following steps: (a) specifying a pressure differential between the first and second reservoirs; (b) calculating a volume exchanged within a specified time interval between the first and second reservoirs via the valve, on the basis of a value for the pressure differential that is valid at the start of the time interval; (c) calculating a volume to be exchanged between the two reservoirs to achieve equal pressures in them; (d) if the amount of the exchanged volume calculated in step (b) is greater than the volume to be exchanged as calculated in step (c), replacing the value of the exchanged volume with that of the volume to be exchanged; and (e) adopting the volume value obtained in step (d) as the change in the volume in the second reservoir and determining the pressure change in the reservoirs on the basis of

Abstract: A brake force control apparatus which can quickly supply pressurized brake fluid to wheel cylinders immediately after a condition for starting a brake assist control is established. The brake force control apparatus has emergency brake determining structure for determining an emergency brake operation performed by a driver, a high pressure source for generating a fluid pressure which is higher than a fluid pressure generated by a master cylinder, and a supply for supplying brake fluid from the pump to a wheel cylinder based on the determination made by the emergency brake determining structure. Actuating structure is provided for actuating the high pressure source before the fluid pressure is supplied by the supply.

Abstract: A hydraulic automotive vehicle brake system with wheel slip control includes at least one non-return valve with a closure member that is lifted from its valve seat during evacuation of the brake system. An elastomeric sealing element is arranged between the closure member and the valve seat member.

Abstract: A device for controlling an electro-hydraulic brake system of a vehicle checks if the battery or the alternator forming an electric power source for the electric part of the brake system is in its normal operating condition, and when the battery or the alternator is not in its normal operating condition, lowers the load imposed on the battery, so as to care the battery against a too soon failure. The device may also check if the driver is pumping the brake pedal at a substantial standstill of the vehicle, and when the brake pedal is so pumped, also lowers the load imposed on the battery, so as to care the battery against a useless consumption of the battery.

Abstract: A vehicle brake system which permits both anti-lock control and different controls of independent force braking operations. In an independent force braking operation, a starting brake pressure is built up in the return circuit in the wheel brakes by way of a precharging pressure generator and the pump and is modulated in the following control phase according to the control algorithms of the selected control. Interposed between the precharging pressure generator and the return pump is a change-over valve which has three switching positions, i.e., one closed, one open, and one throttled. The change-over valve adopts its open position in the filling phase and its throttled position in the control phase. It is so configured that the switching position is achieved as a function of the initial pressure in the inlet chamber but independently of the actuating force which actuates the valve.

Abstract: Hydraulic Brake System with a Device for Active Braking In order to enable a hydraulic brake system which has a self-priming return pump (14) to quickly fill the wheel brakes (5) in an active braking operation, the present invention discloses the provision of a pressure-volume converter (20) on the pressure side of the return pump (14). The converter (20) causes a large pressure fluid volume to be conducted into the brake line (4) to the wheel brake (5) concerned at a small delivery volume of the return pump (14). This is possible because a return pump can generate high pressure and, thus, produce a sufficient amount of force to displace a stepped piston which can then displace a large quantity of pressure fluid. To permit the development of a sufficient back pressure on the pressure side of the return pump (14), a pilot pressure non-return valve (19) is arranged in the pressure line (18) which extends in parallel to the pressure-volume converter (20).

Abstract: A brake fluid pressure controller of a brake having a master cylinder and wheel cylinders includes a control valve having a pilot piston, wherein pressure generated in the master cylinder acts on the pilot piston to control pressure generated in a pressure source, and wherein the generated pressure is applied to the wheel cylinders, and changeover valves for applying the pressure on the pilot piston.

Abstract: A braking hydraulic pressure control apparatus for a vehicle comprising switching valve capable of switching between communicating and shut-off states between a master cylinder and hydraulic passages, and between communicating and shut-off states between the master cylinder and open passages. A driving-wheel control valve is also provided for controlling hydraulic pressure in driving-wheel brakes, and pumps whose inlet ports are connected to respective reservoirs and whose discharge ports are connected to respective hydraulic passages. The open passages are connected to the inlet ports of the respective pumps to improve the ability to remove air from the hydraulic pressure system, and allow simpler air-removing equipment to be utilized. The switching valve comprise opened-type and closed-type electromagnetic valves. Opened-type electromagnetic valves are positioned between the master cylinder and the hydraulic passages.

Abstract: A first fluid line couples first and second wheel cylinders. A second fluid line couples third and fourth wheel cylinders. A first pressure increasing unit increases pressure applied to the first and second wheel cylinders to a second pressure level which is greater than a first pressure generated by a master cylinder. When the first pressure increasing unit is in operation, a pressure difference setting unit sets a difference between pressure applied to the first and second wheel cylinders and pressure applied to the third and fourth wheel cylinders.

Abstract: An hydraulic braking system of the brake-by-wire type has an hydraulic pressure source comprising an hydraulic accumulator adapted to be charged by a pump. An accumulator isolating valve is so positioned and biased to correspond to the direction of flow from the accumulator to a solenoid-operated proportional valve. The valve is biased into a closed position in opposition to the flow from the pump to the accumulator.

Abstract: A brake system including a master cylinder for generating pressurized fluid, a wheel brake in fluid communication with the master cylinder, and a first valve for regulating the flow of fluid between the master cylinder and the wheel brake. The brake system further includes a pedal travel simulator including a housing having a bore formed therein. A piston is slidably disposed in the bore. The piston and the housing generally defining a fluid chamber which is in fluid communication with the master cylinder. The pedal travel simulator further includes a spring which biases the piston in a direction so as to contract the fluid chamber. The brake system further includes a source of pressurized fluid and a boost valve which is in fluid communication with the source of pressurized fluid and the wheel brake.

Abstract: A method and a device which are used for forming and/or adapting a driving signal of an arrangement for delivering a pressurized medium in a braking system. The driving signal, in particular, of a pump of a braking system, is a function of at least one driving signal and/or the formation of the driving signal of a shut-off device, in particular, of at least one valve, for the inlet and/or outlet and/or passage of the pressurized medium. A delivery rate of the pump is adapted in a manner compatible with the situation, including the valve position resulting from the driving signal and/or its formation and/or the prevailing pressure ratios.