A system and method for conserving vacuum within a vehicle is described. In one example, vacuum is conserved via limiting volume expansion of a brake booster working chamber.

A method and system for management of a vacuum pump connected to a braking system of a motor vehicle, and use of an electronic control unit connected to the vacuum pump. At least one differential pressure threshold associated with the vacuum pump, selected from a first differential pressure threshold controlling stopping of operation of the vacuum pump, a second differential pressure threshold controlling starting of the vacuum pump, and a third differential pressure threshold, lower than the second threshold and signalling alerts representative of operating faults, is determined by taking into account a first set of data representative of the detection or otherwise of a repetitive braking situation and/or a second set of data representative of altitude of the vehicle.

A method and system for management of a vacuum pump connected to a braking system of a motor vehicle, and use of an electronic control unit connected to the vacuum pump. At least one differential pressure threshold associated with the vacuum pump, selected from a first differential pressure threshold controlling stopping of operation of the vacuum pump, a second differential pressure threshold controlling starting of the vacuum pump, and a third differential pressure threshold, lower than the second threshold and signalling alerts representative of operating faults, is determined by taking into account a first set of data representative of the detection or otherwise of a repetitive braking situation and/or a second set of data representative of altitude of the vehicle.

A Venturi device for producing vacuum from fluids in an engine system has a body defining a Venturi gap separating apart an outlet end of a converging motive section and an inlet end of a diverging discharge section by a lineal distance, and a suction port in fluid communication with the Venturi gap. The converging motive section and the diverging discharge section both gradually, continuously taper toward the Venturi gap, the converging motive section defines a circular-shaped motive inlet and an elliptical- or polygonal-shaped motive outlet, the diverging discharge section defines an elliptical- or polygonal-shaped discharge inlet, and an inner passageway of the converging motive section transitions as a hyperbolic function from the motive inlet to the elliptical- or polygonal-shaped motive outlet.

A Venturi device for producing vacuum from fluids in an engine system has a body defining a Venturi gap separating apart an outlet end of a converging motive section and an inlet end of a diverging discharge section by a lineal distance, and a suction port in fluid communication with the Venturi gap. The converging motive section and the diverging discharge section both gradually, continuously taper toward the Venturi gap, the converging motive section defines a circular-shaped motive inlet and an elliptical- or polygonal-shaped motive outlet, the diverging discharge section defines an elliptical- or polygonal-shaped discharge inlet, and an inner passageway of the converging motive section transitions as a hyperbolic function from the motive inlet to the elliptical- or polygonal-shaped motive outlet.

A hydraulic brake assist vacuum maintenance system includes a vacuum source, a vacuum booster/master cylinder interfacing with the vacuum source, a brake pedal interfacing with the vacuum booster/master cylinder, a brake control unit interfacing with the vacuum booster/master cylinder, wheel brakes interfacing with the brake control unit and a hydraulic brake assist interfacing with the brake control unit and adapted to hydraulically operate the wheel brakes upon reduction or cessation of vacuum pressure from the vacuum source to the vacuum booster/master cylinder.

A hydraulic brake assist vacuum maintenance system includes a vacuum source, a vacuum booster/master cylinder interfacing with the vacuum source, a brake pedal interfacing with the vacuum booster/master cylinder, a brake control unit interfacing with the vacuum booster/master cylinder, wheel brakes interfacing with the brake control unit and a hydraulic brake assist interfacing with the brake control unit and adapted to hydraulically operate the wheel brakes upon reduction or cessation of vacuum pressure from the vacuum source to the vacuum booster/master cylinder.

The present invention relates to a pulsation reduction apparatus of a hydraulic piston pump, comprising: a block housing that has one end connected to the first hydraulic circuit and the other end connected to the second hydraulic circuit; a damper that is embedded in the block housing, absorbs pressure resulting from working fluid introduced to the first hydraulic circuit, assists with pressure increase of the second hydraulic circuit, and allows shape deformation; and viscosity damping units that are embedded in the block housing, are arranged between the first hydraulic circuit and the damper and between the second hydraulic circuit and the damper, and reduce viscosity of the working fluid introduced from the first and second hydraulic circuits, thereby reducing pressure pulsation and stably performing shock absorption and pressure increase at the same time with a relatively simple configuration.

The present invention relates to a pulsation reduction apparatus of a hydraulic piston pump, comprising: a block housing that has one end connected to the first hydraulic circuit and the other end connected to the second hydraulic circuit; a damper that is embedded in the block housing, absorbs pressure resulting from working fluid introduced to the first hydraulic circuit, assists with pressure increase of the second hydraulic circuit, and allows shape deformation; and viscosity damping units that are embedded in the block housing, are arranged between the first hydraulic circuit and the damper and between the second hydraulic circuit and the damper, and reduce viscosity of the working fluid introduced from the first and second hydraulic circuits, thereby reducing pressure pulsation and stably performing shock absorption and pressure increase at the same time with a relatively simple configuration.

Described are a method and a device for activating an electric vacuum pump for a brake booster of a vehicle. The brake booster is supplied with a vacuum from a vacuum reservoir. The vacuum pump is designed to increase the vacuum in the vacuum reservoir as soon as the vacuum drops below a predefinable switch-on threshold. In order to avoid unnecessarily frequent switching on of the vacuum pump, which may irritate the driver, an expected decrease of the vacuum in the vacuum reservoir as a result of an instantaneous braking operation is estimated and the switch-on threshold of the vacuum pump is temporarily reduced if the vacuum instantaneously prevailing in the vacuum reservoir minus the estimated vacuum decrease is greater than a predetermined adjustment point vacuum, below which the brake booster can no longer act in a sufficiently boosting manner.