Disclosed is a pulsation damping device of a hydraulic brake system including a first damper having a first damping chamber whose volume is varied by the hydraulic pressure of the brake oil, and a second damper having a second damping chamber whose volume is varied by the hydraulic pressure of the brake oil, wherein the volume change rate of the first damping chamber relative to the hydraulic pressure of the brake oil is provided to be larger than the volume change rate of the second damping chamber, and the hydraulic pressure of the corresponding brake oil in the first damping chamber when reaching the maximum variable volume is provided to be smaller than the hydraulic pressure of the corresponding brake oil in the second damping chamber when reaching the maximum variable volume.

A pressure variation damper for a slip-regulated, hydraulic vehicle brake system includes a damper housing and a tubular damper element. The damper element is disposed in the damper housing and configured for elastic deformation. The damper element is subjected on an inside and/or on an outside to a fluid. Possible pressure variations of the fluid are to be damped. The damper element comprises a corrugation on the outside and a corrugation on the inside configured to reduce a change in a wall thickness of the damper element owing to the corrugation on the outside.

A vehicle braking system includes a wheel cylinder, a brake pedal, a master cylinder, a master cylinder circuit, a primary braking unit operable to generate a braking force at the wheel cylinder in a primary mode, decoupled from the master cylinder circuit, a secondary braking unit including a second electrically-actuated pressure generating unit and operable to generate a braking force at the wheel cylinder in a secondary mode of operation, a plurality of valves configured to provide anti-lock braking at the wheel cylinder upon loss of traction during braking in the primary mode of operation, and a controller programmed to actuate the plurality of valves and further programmed to actuate the second electrically-actuated pressure generating unit upon loss of traction in the primary mode of operation to generate pulsations within the master cylinder circuit to provide a feedback force at the brake pedal indicative of the anti-lock braking.

A method for reducing pressure peaks in hydraulic brake systems comprises an electrically operated pressurization device. A drive resistance variable of the pressurization device is measured, for example the torque. A speed variable of the pressurization device is measured. A quotient of the drive resistance variable and the speed variable is calculated. The quotient is monitored for the occurrence of a jump and, in the case of a determined jump, a speed requirement of the pressurization device is reduced and/or a hydraulic valve for pressure dissipation is actuated.

Provided is a novel pressure pulsation reducing device of a hydraulic system that reduces a stress generated in a metal diaphragm and is excellent in durability. A plurality of concentric recess portions projecting toward an interior space of a pulsation damping member is formed on one of metal diaphragms, and a plurality of concentric recess portions projecting toward the interior space of the pulsation damping member is formed on the other metal diaphragm likewise. When a predetermined pressure is applied to the metal diaphragms, at least one recess portion of one of the metal diaphragms and at least one recess portion of the other metal diaphragm are in contact with each other.

An electric brake system comprising: a master cylinder configured to a reservoir storing oil therein and configured to generate hydraulic pressure according to a pedal effort of a brake pedal; a cut valve installed at a backup flow path connecting the master cylinder to a wheel cylinder; a simulation device including a simulation chamber connected to the master cylinder at a front end of the cut valve to provide a reaction force according to the pedal effort of the brake pedal, a simulation valve provided at a flow path connecting the master cylinder to the simulation chamber; a hydraulic pressure supply device configured to operate in response to an electrical signal of a pedal displacement sensor sensing a displacement of the brake pedal, and a damping member provided at a flow path connecting the hydraulic pressure chamber to the front end of the cut valve, wherein the damping member delivers a pressure pulsation generated in the hydraulic pressure chamber to the brake pedal in an anti-lock brake system (ABS) mode.

A damping device, for example for damping pressure pulses in a brake circuit of a slip-controllable hydraulic vehicle brake system, includes a damper chamber with a pressure medium volumetric capacity, which can be varied in a pressure-dependent manner, and a flow resistor connected downstream thereof. Disadvantageously, the pressure medium volumetric capacity of the damping device is not available for the brake pressure build-up when the brake pressure is generated by the driver, and the pedal travel on a brake master cylinder of a vehicle brake system is therefore lengthened. A mechanism limits the pressure medium volumetric capacity of the damping device in the case of a passive braking operation. In the case of partially active or fully active braking operations, in contrast, the mechanism has no effect and the full scope of the pressure medium volumetric capacity of the damping device is available for damping pressure pulses.

A valve block for an electronic brake system is disclosed. The valve block is configured to have two hydraulic circuits, a plurality of accommodating bores in which valves, pumps, low pressure accumulators, pressure sensors, and a motor are installed in order to control the braking hydraulic pressure supplied from a master cylinder to a wheel cylinder installed in each wheel, and a plurality of flow passages for connecting the plurality of accommodating bores, wherein on opposite side surfaces of the valve block, pump accommodating bores are formed symmetrically to each other to accommodate the pump, and first damping bores having an arrangement parallel to the pump accommodating bores are formed above the pump accommodating bores, wherein on an upper surface of the valve block, a pair of second damping bores is formed so as to be positioned above the first damping bores, and wherein first hydraulic lines are formed in a straight line from a bottom surface of the pair of second damping bores toward a bottom surface of the valve block, so that a discharge side of the pump accommodating bores and a suction side of the first damping bores, and a discharge side of the second damping bores and the bottom surface of the second damping bores are connected by the first hydraulic lines.

A hydraulic unit, in particular a hydraulic unit for a slip-controllable vehicle brake system, includes a housing block, a pump, and a damping device. The pump has an intake side and a delivery side. The housing block has a pump receptacle that holds the pump, a first fluid duct that intersects the pump receptacle in a region of the delivery side of the pump, and a second fluid duct opening into the pump receptacle in the region of the delivery side of the pump, and a first separation point that seals off the first fluid duct from the second fluid duct. The damping device damps pulsations and reduces operating noise of the hydraulic unit without (i) having a detrimental effect on functional characteristics of the unit, in particular on pressure build-up dynamics of the vehicle brake system, or without (ii) jeopardizing a compact construction of the hydraulic unit.

A vehicle brake device provided with a hydraulic pressure generating portion, an actuator and a controlling portion which maintains a driving force of the driving portion when a control subject pressure in a control subject chamber is within a dead zone, wherein the control subject pressure varies in response to a variation of the master pressure and a pulsation is generated in the master pressure accompanying an operation of the actuator. The vehicle brake device further includes a rigidity information obtaining portion which obtains a rigidity information and a dead zone setting portion which sets the dead zone based on the rigidity information obtained by the rigidity information obtaining portion such that the higher the rigidity of the control subject chamber, or the higher the probability of rigidity increase of the control subject chamber, the wider the dead zone is set.