Control device for internal combustion engine with supercharger

摘要

An object of the present invention is to prevent hunting of a throttle in a region in which a throttle upstream pressure and a throttle downstream pressure become substantially equal to each other in an internal combustion engine with a supercharger. For this purpose, a control device for an internal combustion engine with a supercharger provided by the present invention processes a signal of a throttle opening which is calculated by using a formula of throttling when a ratio of the throttle upstream pressure and the throttle downstream pressure has a value close to 1, and controls an operation of the throttle with the throttle opening the change speed of which is lessened as a target throttle opening.

主权项

1. A control device for an internal combustion engine with a supercharger including an intake passage which introduces air taken in from an outside into a cylinder, a compressor which is disposed in the intake passage, a throttle which is disposed in the intake passage downstream of the compressor, and an intake valve which is disposed in a connection portion of the intake passage and the cylinder, the control device comprising:
throttle passing flow rate calculating means that calculates a throttle passing flow rate which is necessary for realization of a target intake air quantity; throttle upstream pressure acquiring means that acquires a throttle upstream pressure which is a pressure of air in the intake passage from the compressor to the throttle; throttle downstream pressure acquiring means that acquires a throttle downstream pressure which is a pressure of air in the intake passage from the throttle to the intake valve; throttle opening calculating means that calculates a throttle opening necessary for realization of the throttle passing flow rate by using a formula of throttling with a ratio of the throttle upstream pressure and the throttle downstream pressure as a parameter; change speed lessening means that processes a signal of the throttle opening which is calculated in the throttle opening calculating means and lessens a change speed thereof; target throttle opening determining means that determines the throttle opening the change speed of which is lessened by the change speed lessening means as a target throttle opening when all of predetermined lessening conditions are satisfied, and determines the throttle opening which is calculated by the throttle opening calculating means as a target throttle opening when the lessening conditions are not satisfied; and throttle control means that controls an operation of the throttle in accordance with the target throttle opening, wherein the lessening conditions include that magnitude of a deviation of a value of the pressure ratio with respect to 1 is not larger than a predetermined value.