Various systems and methods are described for generating vacuum within an engine intake. An intake throttle including a hollow throttle plate having a plurality of perforations along its circumference is mounted on a hollow shaft, which in turn may be coupled to a vacuum consumption device. When vacuum is demanded by the vacuum consumption device, the opening of the throttle plate may be decreased and vacuum may be generated by flowing intake air past the perforated edge of the throttle plate.

A system and method for increasing brake line pressure after brake booster vacuum has been exhausted is presented. In one example, brake line pressure is increased at a same rate after brake booster vacuum is exhausted as before brake booster vacuum is exhausted so that a driver experiences a continuous braking force.

Various systems and methods are described for generating vacuum within an engine intake. A system may comprise a throttle body with a slideable throttle body and a throttle fixture with a hollow interior passage located therein.

An abnormality detection device of an internal combustion engine includes an ECU that is an abnormality detection unit detecting a leakage occurrence of a second pure pipe. When the internal combustion engine is in a supercharging operation state that a supercharger operates and the second purge pipe is closed by a second purge valve, the ECU detects the leakage occurrence of the second purge pipe based on a differential pressure between a pressure in the second purge pipe and an atmospheric pressure. In this case, the valve pressure in the second purge pipe is a pressure in the second purge pipe between the second purge valve and the intake pipe.

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.

A method for controlling an engine variable valve timing of a hybrid electric vehicle, may include providing a cam position setting table of a fuel efficiency prioritized intake/exhaust cam control mode, and a cam position setting table of a normal intake/exhaust cam control mode, the cam position setting table of the fuel efficiency prioritized intake/exhaust cam control mode being differentiated from the cam position setting table of the normal intake/exhaust cam control mode; selecting one of the fuel efficiency prioritized intake/exhaust cam control mode and the normal intake/exhaust cam control mode by a canister loading amount and whether or not diagnosis of an intake cam and diagnosis of an exhaust cam are completed; and determining position control values of the intake and exhaust cams by using the cam position setting table and then controlling positions of the intake cam and the exhaust cam by the determined position control values.

Disclosed is an apparatus for using negative pressure energy of an engine, comprising: a first cavity (10), which first cavity (10) is in communication with the atmosphere via a first intake port (20); a second cavity (30), which second cavity (30) is in communication with the intake port of the engine (50) for supplying air to the intake port of the engine; a second intake port (40), which second intake port (40) is connected to the second cavity (30), wherein when the second intake port (40) is open, the second cavity (30) is in communication with the atmosphere for supplying the air to the intake port of the engine; and a rotating device (60), which rotating device (60) is located between the first cavity (10) and the second cavity (30), and can be rotated under the action of pressure difference between the first cavity (10) and the second cavity (30). Further disclosed is a method for using negative pressure energy of an engine. The apparatus and method for using the negative pressure energy of an engine is able to better cooperate with other parts of the vehicle while efficiently using energy.

A method and system for cleaning a brake booster aspirator shut-off valve are provided. The shut-off valve is operable to selectively permit flow of intake air through an aspirator; the aspirator bypasses a throttle of an engine and provides a vacuum source for a brake booster. The method comprises determining whether the shut-off valve may require cleaning, opening the shut-off valve so as to permit a flow of air through the shut-off valve and clean the shut-off valve and adjusting the throttle position of the engine to compensate for the additional flow of intake air through the aspirator.

A negative pressure abnormality detection apparatus includes a negative pressure sensor to output a signal representing negative pressure in a negative pressure chamber of a brake booster into which intake negative pressure of an intake manifold generated by rotation of an engine is introduced; a negative pressure detection unit to detect the negative pressure based on the signal; an abnormality determination unit to determine whether an abnormality occurs with the negative pressure sensor, based on whether the negative pressure is shifted toward atmospheric or vacuum pressure relative to a threshold, when a state continues for a predetermined time or longer during which the engine rotates and a negative-pressure-expending braking operation is not performed; and a threshold change unit to change the threshold depending on opening of a throttle valve in an intake pipe connected with the intake manifold, while the state continues.

A control device calculates an estimate of negative intake pressure based on the relationship between the rotation speed of a crankshaft and a throttle opening degree (Step S24). Then, the control device sets the estimate PE of the negative intake pressure, which is calculated in Step S24, to a greater value as combustion efficiency of CNG used in engine operation becomes higher (Step S25). When the corrected estimate PE of the negative intake pressure becomes smaller than or equal to a reference value PTh (Step S26: YES), the control device starts a negative pressure recovery procedure (Step S27).