Abstract: A first arrival flow rate that is a flow rate of evaporative fuel gas that has arrived in a throttle downstream portion located downstream of a throttle valve in an intake pipe via a second purge passage after passing through a purge control valve is estimated based on a valve passage flow rate that is a flow rate of evaporative fuel gas that has passed through the purge control valve, and a first response delay in the flow of evaporative fuel gas through a route extending from the purge control valve to the throttle downstream portion via the second purge passage.

Abstract: During execution of a purge, a purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio detected by an air-fuel ratio sensor from a required air-fuel ratio. In this case, the purge concentration-related value is updated using an update amount with a smaller absolute value when the purge is a second purge of supplying evaporated fuel gas to an intake pipe through a second purge passage than when the purge is a first purge of supplying the evaporated fuel gas to the intake pipe through a first purge passage.

Abstract: When first switching of switching from a first purge of supplying evaporated fuel gas to an intake pipe through a first purge passage to a second purge of supplying the evaporated fuel gas to the intake pipe through a second purge passage occurs and then second switching of switching from the second purge to the first purge occurs, a purge concentration-related value is corrected to a value closer to a first stored value that is the purge concentration-related value immediately before the first switching than to a second stored value that is the purge concentration-related value immediately before the second switching.

Abstract: Fuel injection control of an engine is executed by setting a required injection amount and an air-fuel ratio correction amount. When setting conditions are met, the air-fuel ratio correction amount is set for a corresponding region to which a current intake air amount or load ratio belongs among a plurality of regions into which the range of the intake air amount or the load ratio is divided such that a region of a larger intake air amount or a higher load ratio becomes wider than a region of a smaller intake air amount or a lower load ratio. When purge conditions are met, a purge control valve is controlled such that purge of supplying an evaporated fuel gas to an intake pipe is executed based on a required purge ratio.

Abstract: When a predetermined condition is satisfied, a flow rate ratio of a first passage flow rate to a second passage flow rate is estimated based on a throttle post pressure being a pressure on a downstream side of an intake pipe with respect to a throttle valve and an ejector pressure being a pressure of a suction port of an ejector. The first passage flow rate is a flow rate of an evaporated fuel gas flowing in a first purge passage. The second passage flow rate is a flow rate of the evaporated fuel gas flowing in a second purge passage. The first passage flow rate and the second passage flow rate are estimated based on the flow rate ratio and a valve passing flow rate being a flow rate of the evaporated fuel gas that passes through a purge control value.

Abstract: An engine apparatus includes an engine, a supercharger, an evaporated fuel treatment device, a controller and the engine apparatus is configured to determine a purge classification whether the evaporated fuel is a first purge in which the evaporated fuel flows dominantly in a first purge passage or a second purge in which the evaporated fuel flows dominantly in a second purge passage based on a relative ejector pressure that is a pressure of a suction port of the ejector and a value obtained by adding an offset amount based on a cross-sectional area of the second purge passage with respect to a cross-sectional area of the first purge passage to a pressure behind a throttle valve that is the pressure on a downstream side of the throttle valve of the intake pipe.

Abstract: A fuel injection valve is controlled by setting a required injection amount using a required load factor of an engine and a purge correction amount. A purge control valve is controlled using a driving duty based on a required purge ratio when a purge of supplying the evaporated fuel gas to an intake pipe is being executed. During execution of the purge, the purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio from a required air-fuel ratio. The certainty of the purge concentration-related value is estimated using a first counter that reflects a number of times of learning of the purge concentration-related value during a first purge and that does not reflect a number of times of learning of the purge concentration-related value during a second purge.

Abstract: When an execution condition for a purge of supplying evaporated fuel gas to an intake pipe is met, a required purge ratio is set within a range equal to or higher than a lower-limit purge ratio, and a purge control valve is controlled using a driving duty based on the required purge ratio. In this case, when the execution condition is continuously met, an ejector pressure is estimated based on a pressure difference between a supercharging pressure and a pre-compressor pressure, and on the driving duty, and the lower-limit purge ratio is set based on a post-throttle-valve pressure and on the ejector pressure. The value of the lower-limit purge ratio is set to zero immediately after the execution condition switches from being not met to being met.

Abstract: A first arrival flow rate that is a flow rate of evaporative fuel gas that has arrived in a throttle downstream portion located downstream of a throttle valve in an intake pipe via a second purge passage after passing through a purge control valve is estimated based on a valve passage flow rate that is a flow rate of evaporative fuel gas that has passed through the purge control valve, and a first response delay in the flow of evaporative fuel gas through a route extending from the purge control valve to the throttle downstream portion via the second purge passage.

Abstract: When a predetermined condition is satisfied, a flow rate ratio of a first passage flow rate to a second passage flow rate is estimated based on a throttle post pressure being a pressure on a downstream side of an intake pipe with respect to a throttle valve and an ejector pressure being a pressure of a suction port of an ejector. The first passage flow rate is a flow rate of an evaporated fuel gas flowing in a first purge passage. The second passage flow rate is a flow rate of the evaporated fuel gas flowing in a second purge passage. The first passage flow rate and the second passage flow rate are estimated based on the flow rate ratio and a valve passing flow rate being a flow rate of the evaporated fuel gas that passes through a purge control value.

Abstract: A fuel injection valve is controlled by setting a required injection amount using a required load factor of an engine and a purge correction amount. A purge control valve is controlled using a driving duty based on a required purge ratio when a purge of supplying the evaporated fuel gas to an intake pipe is being executed. During execution of the purge, the purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio from a required air-fuel ratio. The certainty of the purge concentration-related value is estimated using a first counter that reflects a number of times of learning of the purge concentration-related value during a first purge and that does not reflect a number of times of learning of the purge concentration-related value during a second purge.

Abstract: During execution of a purge, a purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio detected by an air-fuel ratio sensor from a required air-fuel ratio. In this case, the purge concentration-related value is updated using an update amount with a smaller absolute value when the purge is a second purge of supplying evaporated fuel gas to an intake pipe through a second purge passage than when the purge is a first purge of supplying the evaporated fuel gas to the intake pipe through a first purge passage.

Abstract: When an execution condition for a purge of supplying evaporated fuel gas to an intake pipe is met, a required purge ratio is set within a range equal to or higher than a lower-limit purge ratio, and a purge control valve is controlled using a driving duty based on the required purge ratio. In this case, when the execution condition is continuously met, an ejector pressure is estimated based on a pressure difference between a supercharging pressure and a pre-compressor pressure, and on the driving duty, and the lower-limit purge ratio is set based on a post-throttle-valve pressure and on the ejector pressure. The value of the lower-limit purge ratio is set to zero immediately after the execution condition switches from being not met to being met.

Abstract: When first switching of switching from a first purge of supplying evaporated fuel gas to an intake pipe through a first purge passage to a second purge of supplying the evaporated fuel gas to the intake pipe through a second purge passage occurs and then second switching of switching from the second purge to the first purge occurs, a purge concentration-related value is corrected to a value closer to a first stored value that is the purge concentration-related value immediately before the first switching than to a second stored value that is the purge concentration-related value immediately before the second switching.

Abstract: Fuel injection control of an engine is executed by setting a required injection amount and an air-fuel ratio correction amount. When setting conditions are met, the air-fuel ratio correction amount is set for a corresponding region to which a current intake air amount or load ratio belongs among a plurality of regions into which the range of the intake air amount or the load ratio is divided such that a region of a larger intake air amount or a higher load ratio becomes wider than a region of a smaller intake air amount or a lower load ratio. When purge conditions are met, a purge control valve is controlled such that purge of supplying an evaporated fuel gas to an intake pipe is executed based on a required purge ratio.

Abstract: An engine apparatus includes an engine, a supercharger, an evaporated fuel treatment device, a controller and the engine apparatus is configured to determine a purge classification whether the evaporated fuel is a first purge in which the evaporated fuel flows dominantly in a first purge passage or a second purge in which the evaporated fuel flows dominantly in a second purge passage based on a relative ejector pressure that is a pressure of a suction port of the ejector and a value obtained by adding an offset amount based on a cross-sectional area of the second purge passage with respect to a cross-sectional area of the first purge passage to a pressure behind a throttle valve that is the pressure on a downstream side of the throttle valve of the intake pipe.