This blow-by gas recirculation device for an internal combustion engine is provided with a vacuum pump which supplies negative pressure to a brake booster and usable for recirculation of blow-by gas to an intake passage. This device includes: a PCV device for recirculating blow-by gas in a crankcase to the intake passage; a ventilation shortage region determination unit which determines whether or not an operational region of the engine is a PCV ventilation flow rate shortage region; and a brake negative pressure determination unit which determines whether or not the negative pressure of the brake booster is secured. The vacuum pump ventilates blow-by gas in the crankcase only when the determination units determines that the operational region is the PCV ventilation flow rate shortage region and that the negative pressure is secured. This reduces a contact risk of blow-by gas with engine oil, and inhibits the degradation of the oil.

Systems and methods for a braking a vehicle. In one example, the braking system includes a friction braking system, a regenerative braking system, and an electronic processor. The electronic processor is communicatively coupled to the friction braking system and the regenerative braking system. The electronic processor is configured to receive a driver brake request and determine a brake failure state. The brake failure state indicates a brake failure. In response to determining the brake failure state, the electronic processor applies a braking force based on the driver brake request. The braking force includes a frictional braking force generated by the friction braking system and a regenerative braking force generated by the regenerative braking system.

Systems and methods for a braking a vehicle. In one example, the braking system includes a friction braking system, a regenerative braking system, and an electronic processor. The electronic processor is communicatively coupled to the friction braking system and the regenerative braking system. The electronic processor is configured to receive a driver brake request and determine a brake failure state. The brake failure state indicates a brake failure. In response to determining the brake failure state, the electronic processor applies a braking force based on the driver brake request. The braking force includes a frictional braking force generated by the friction braking system and a regenerative braking force generated by the regenerative braking system.

A method and system for determining the pressure in a brake booster used to actuate a brake system having at least one main brake cylinder. The brake booster connected in a fluid-conducting manner by a non-return valve to an intake manifold of an internal combustion engine. A reduced pressure loss in the brake booster resulting from actuation of the main brake cylinder is balanced with the reduced pressure gain in the brake booster as a result of a pressure difference between the brake booster pressure and the intake manifold pressure. The reduced pressure gain in the brake booster is determined based on time, the air mass flow between the brake booster, and the intake manifold.

A method and system for determining the pressure in a brake booster used to actuate a brake system having at least one main brake cylinder. The brake booster connected in a fluid-conducting manner by a non-return valve to an intake manifold of an internal combustion engine. A reduced pressure loss in the brake booster resulting from actuation of the main brake cylinder is balanced with the reduced pressure gain in the brake booster as a result of a pressure difference between the brake booster pressure and the intake manifold pressure. The reduced pressure gain in the brake booster is determined based on time, the air mass flow between the brake booster, and the intake manifold.

A control device for an electric vacuum pump that generates a negative pressure includes a negative-pressure detector for detecting the negative pressure generated by the electric vacuum pump and a pump stop control unit that is adapted to stop the electric vacuum pump when the negative pressure detected by the negative-pressure detector is not less than a predetermined value. The pump stop control unit is configured to determine an OFF timing at a present stage of the electric vacuum pump based on reference pump-filling-performance data, which is data about a reference negative pressure ratio relative to an elapsed time at an initial stage of the electric vacuum pump, and by referring to present pump-filling-performance data, which is data about a present negative pressure ratio relative to an elapsed time at the present stage of the electric vacuum pump.

A control device for an electric vacuum pump that generates a negative pressure includes a negative-pressure detector for detecting the negative pressure generated by the electric vacuum pump and a pump stop control unit that is adapted to stop the electric vacuum pump when the negative pressure detected by the negative-pressure detector is not less than a predetermined value. The pump stop control unit is configured to determine an OFF timing at a present stage of the electric vacuum pump based on reference pump-filling-performance data, which is data about a reference negative pressure ratio relative to an elapsed time at an initial stage of the electric vacuum pump, and by referring to present pump-filling-performance data, which is data about a present negative pressure ratio relative to an elapsed time at the present stage of the electric vacuum pump.

An exemplary brake booster device includes, among other things, a brake booster mounted on a vehicle component, and an actuator that, in response to a force applied to the actuator by a gearbox housing, pivots to move the brake booster upward. The actuator includes at least two pivot elements spaced from each other, and a displacement mounted in a jointed manner between the at least two pivot elements.

In order to minimize spreading, without additional parts, of connecting bolts of a pneumatic brake booster in a manner which is brought about by the deformation of a bearing surface on a booster housing before and during its assembly on a provided vehicle body part, it is proposed that the bearing surface is assigned a planar surface section in an immediately adjacent manner which is configured so as to be plane-parallel with respect to the bearing surface and so as to be axially inwardly recessed on the booster housing with a circumferential step.

In order to minimize spreading, without additional parts, of connecting bolts of a pneumatic brake booster in a manner which is brought about by the deformation of a bearing surface on a booster housing before and during its assembly on a provided vehicle body part, it is proposed that the bearing surface is assigned a planar surface section in an immediately adjacent manner which is configured so as to be plane-parallel with respect to the bearing surface and so as to be axially inwardly recessed on the booster housing with a circumferential step.