JP2006057548A5 - - Google Patents

Claims (7)

A variable nozzle type turbocharger capable of changing the cross-sectional area of the turbine inlet, supercharging assist means for operating the electric motor to assist supercharging by the turbocharger, the assist amount by the electric motor, and the And a control means for controlling the nozzle opening of the turbocharger, wherein the control means has a transient state in which a response delay of the actual supercharging pressure occurs with respect to an increase in the target supercharging pressure. when, internal combustion, wherein the nozzle opening degree of the turbocharger is reduced a predetermined time period Rutotomoni, to assist the supercharging operates the electric motor in accordance with the said nozzle opening is reduced, it Supercharging system for engines.   The control means determines that the predetermined period has ended on the condition that the actual supercharging pressure has increased to a first set pressure before reaching the target supercharging pressure, and after the end of the predetermined period, The supercharging system according to claim 1, wherein an increase in the nozzle opening according to an operating state of the internal combustion engine is allowed. The control means continues the assist by the electric motor until the actual boost pressure reaches a second set pressure lower than the first set pressure during the predetermined period, and the actual boost pressure is set to the second set pressure. When raised to the set pressure, thereafter the supercharging system of claim 2, wherein the controller controls the electric motor so assist amount is decline with respect to the supercharging.   The supercharging system according to claim 3, wherein the control unit stops the electric motor when the actual supercharging pressure rises to the first set pressure.   The control means is configured such that, when a factor for limiting the operation of the electric motor occurs during the operation of the electric motor in the transient state, the assist amount for the supercharging is limited according to the factor. The supercharging system according to any one of claims 1 to 4, wherein the operation of the electric motor is controlled. Motor temperature detecting means for detecting the temperature of the electric motor;
Voltage detecting means for detecting a voltage of a battery electrically connected to the electric motor,
The control means has the factor when the motor temperature detected by the motor temperature detecting means rises above a predetermined temperature or when the battery voltage detected by the voltage detecting means falls below a predetermined voltage. The assist amount required value determined based on the shortage of the actual boost pressure relative to the target boost pressure, and the assist amount limit allowed from the viewpoint of maintaining the battery voltage at the predetermined voltage or higher. Controlling the operation of the electric motor so that an assist amount obtained by multiplying any smaller value by a reduction rate corresponding to the degree of increase of the motor temperature from the predetermined temperature is obtained. The supercharging system according to claim 5, wherein   An EGR passage that recirculates exhaust gas from an exhaust passage of an internal combustion engine to an intake passage, an EGR valve that adjusts a flow rate of exhaust gas flowing through the EGR passage, and an EGR valve control means that controls the opening degree of the EGR valve When the operating state of the internal combustion engine shifts from the mass EGR region to the non-EGR region, the control means is configured such that the pressure of the exhaust gas outlet of the EGR passage is greater than the pressure of the exhaust gas supply port of the EGR passage. The electric motor is operated to assist supercharging by controlling the opening degree of the nozzle to the open side, and the EGR valve control means allows the gas in the intake passage to pass through the EGR passage. The supercharging system according to any one of claims 1 to 5, wherein an opening degree of the EGR valve is controlled so as to be guided to an exhaust passage.