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US 4,550,704 AGranted
Multi-cylinder internal combustion engine having disconnectable groups of cylinders
AssigneeRobert Bosch GmbH
InventorsHans Barho, Helmut Denz
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AssigneeRobert Bosch GmbH
InventorsHans Barho, Helmut Denz
Estimating the term…
Disclosed is a multi-cylinder internal combustion engine in which a group of cylinders is disconnectable in dependence on one or more operational parameters of the engine. The connection or disconnection of the groups of cylinders occurs in response to an engine load variation, to an acceleration signal or to a deceleration signal and to the engine temperature. The switchover takes place within a predetermined time interval. During the switchover of the cylinder groups, the ignition angle and if desired the volumetric efficiency are controlled. When only a part of the cylinders of the engine is in operation after a predetermined number of engine rotations the active cylinders are disconnected and simultaneously the inactive cylinders are connected into operation. During the switchover process any unintentional switchover is prevented by a signal blocking device. A stabilization of idling speed of the engine is selectively made by connecting into operation a group of cylinders or by an auxiliary air flow device. The switchover of cylinder groups during a partial load operation is influenced by switching devices having hysteresis behavior, which also enhances the stabilization during idling operation. The engine of this invention is preferably used in all kinds of motor vehicles.
A multi-cylinder internal combustion engine, particularly for use in motor vehicles, having its cylinders divided into a plurality of groups each including at least one cylinder, at least one of said groups being disconnectable in dependence on the occurrence of at least one operational parameter of the engine, comprising an electrically controlled disconnecting means for disconnecting said one group, monitoring means for monitoring the operational parameters of the engine, control means controlled by said monitoring means to activate said disconnecting device when a predetermined value of the operational parameter is detected, said monitoring means including a device for measuring the engine load and a device for measuring the rotary speed of the engine, said control means including an ignition angle adjusting device and a fuel metering device, means for generating a threshold value depending on the measured engine load and the rotary speed, said threshold value generating means being coupled to said disconnecting means so as to inactivate the same when the threshold value is exceeded, a second means for generating a second threshold depending on the engine load and the rotary speed of the engine, the second threshold being larger than the first-mentioned threshold and being coupled to said disconnecting means so as to disconnect at least one of the cylinder groups in dependence on the second threshold value, and further comprising means for enriching the fuel mixture by a correction factor and means for exchanging the ignition angle prior to the changeover of the cylinder groups so that within a predetermined time interval a maximum torque of the engine is generated.
A multi-cylinder internal combustion engine, particularly for use in motor vehicles, having its cylinders divided into a plurality of groups each including at least one cylinder, at least one of said groups being disconnectable in dependence on the occurrence of at least one operational parameter of the engine, comprising an electrically controlled disconnecting means for disconnecting said one group, monitoring means for monitoring the operational parameters of the engine, control means controlled by said monitoring means to activate said disconnecting device when a predetermined value of the operational parameter is detected, said monitoring means including a device for measuring the engine load and a device for measuring the rotary speed of the engine, said control means including an ignition angle adjusting device and a fuel metering device means for generating a threshold value depending on the measured engine load and the rotary speed, said threshold value generating means being coupled to said disconnecting means so as to inactivate the same when the threshold value is exceeded, a second means for generating a second threshold depending on the engine load and the rotary speed of the engine, the second threshold being larger than the first-mentioned threshold and being coupled to said disconnecting means so as to disconnect at least one of the cylinder groups in dependence on the second threshold value, and wherein prior to the changeover of the cylinder group, depending on the engine load and the rotary speed, a factor for rendering the fuel mixture lean and a factor for retarding the ignition angle are generated and changed in such a manner that within a predetermined time interval a minimum torque of the engine is generated.
Dependencies are inferred from the claim text.