An object is to supply fresh air and EGR gas into a cylinder in good balance according to the required load in a naturally aspirated gasoline engine. When the operation state of the engine falls in a low load range, a control apparatus adjusts the degree of opening of the second throttle while keeping the first throttle fully open and controls EGR gas quantity by adjusting the degree of opening of the EGR valve. When the operation state falls in a middle load range, the apparatus controls EGR gas quantity by adjusting the degree of opening of the first throttle while keeping the EGR valve fully open. When the operation state falls in a high load range, the apparatus adjusts the degree of opening of the first throttle while keeping the second throttle fully open and controls EGR gas quantity by adjusting the degree of opening of the EGR valve.

An engine system includes: a first throttle valve; a turbocharger compressor disposed downstream of the first throttle valve; a charge air cooler disposed downstream of the turbocharger compressor; a second throttle valve located downstream of the turbocharger compressor; a purge inlet located downstream of the first throttle valve and configured to introduce fuel vapor from a fuel tank into intake air; and an engine control module configured to: maintain the first throttle valve in a fully open position; and selectively close the first throttle valve relative to the fully open position in response to receipt of a request to at least one of: purge fuel vapor from the fuel tank; and at least one of decrease and prevent icing of the charge air cooler.

A single-inlet air intake control structure is connected to an engine of a power system and regulates the intake air quantity of the engine. The single-inlet air intake control structure comprises an air cleaner, a control valve, a throttle valve, a first pipe and a second pipe. The first pipe connects the air cleaner and the control valve. The second pipe connects the control valve and the throttle valve. The air cleaner, the first pipe, the control valve, the second pipe and the throttle valve are connected to form an air intake passage. By structural simplifying, the single-inlet air intake control structure controls the air intake passage within an appropriate length range and thus can lower the cost. Furthermore, the single-inlet air intake control structure can directly regulate the intake air quantity of the engine when the engine operates at either a high or a low speed.

An engine system includes: a first throttle valve; a turbocharger compressor disposed downstream of the first throttle valve; a charge air cooler disposed downstream of the turbocharger compressor; a second throttle valve located downstream of the turbocharger compressor; a purge inlet located downstream of the first throttle valve and configured to introduce fuel vapor from a fuel tank into intake air; and an engine control module configured to: maintain the first throttle valve in a fully open position; and selectively close the first throttle valve relative to the fully open position in response to receipt of a request to at least one of: purge fuel vapor from the fuel tank; and at least one of decrease and prevent icing of the charge air cooler.

A two-stroke combustion engine comprising a user-operated throttle control, an adjustable valve arranged to control one or more air intakes of the combustion engine, and a control unit arranged to control a state of the adjustable valve, wherein the combustion engine is arranged to operate in a first idle mode at an idle engine speed below a clutch engagement engine speed when the user-operated throttle control is not engaged, wherein the combustion engine is arranged to operate in a second idle mode at a target engine speed above the clutch engagement engine speed when the user-operated throttle control is engaged and when the engine is not subject to an external load, the control unit being arranged to control the state of the adjustable valve to maintain engine speed at the target engine speed when the engine operates in the second idle mode.

The present invention relates to internal combustion engines. More particularly, the present invention relates to an arrangement whereby internal combustion engines can be operated more efficiently at higher compression pressures. Aspects and/or embodiments seek to provide a method and/or apparatus and/or system for using very high compression ratios in internal combustion engines while preventing damage from pinking or knocking.

A two-stroke combustion engine comprising a user-operated throttle control, an adjustable valve arranged to control one or more air intakes of the combustion engine, and a control unit arranged to control a state of the adjustable valve, wherein the combustion engine is arranged to operate in a first idle mode at an idle engine speed below a clutch engagement engine speed when the user-operated throttle control is not engaged, wherein the combustion engine is arranged to operate in a second idle mode at a target engine speed above the clutch engagement engine speed when the user-operated throttle control is engaged and when the engine is not subject to an external load, the control unit being arranged to control the state of the adjustable valve to maintain engine speed at the target engine speed when the engine operates in the second idle mode.

A two-stroke combustion engine comprising a user-operated throttle control, an adjustable valve arranged to control one or more air intakes of the combustion engine, and a control unit arranged to control a state of the adjustable valve, wherein the combustion engine is arranged to operate in a first idle mode at an idle engine speed below a clutch engagement engine speed when the user-operated throttle control is not engaged, wherein the combustion engine is arranged to operate in a second idle mode at a target engine speed above the clutch engagement engine speed when the user-operated throttle control is engaged and when the engine is not subject to an external load, the control unit being arranged to control the state of the adjustable valve to maintain engine speed at the target engine speed when the engine operates in the second idle mode.

A throttle device, including: a throttle valve (13) disposed in a plurality of intake passages (12) of a throttle body (11); a throttle shaft (14) supporting the throttle valve (13); a motor (15) for driving the throttle valve (13) to open and close through the throttle shaft (14); a rotation transmission mechanism (20) interposed between the motor (15) and the throttle shaft (14); and a position sensor to detect a displacement in the rotation transmission mechanism (20). The rotation transmission mechanism (20) is disposed at a position where the first and the second throttle bodies (11f, 11s) are adjacent, the motor (15) is disposed within an installation width Ws of either one of the first and the second throttle bodies (11f, 11s), and the throttle opening degree sensor (30) is disposed within an installation width Wt of the other one of the first and the second throttle bodies (11f, 11s).

A control method for an internal combustion engine including: setting a target valve opening degree of the first throttle valve in accordance with a load, sensing a valve opening degree of the second throttle valve, judging whether or not the valve opening degree of the second throttle valve is an opening degree on a closing side relative to a predetermined set valve opening degree, and correcting the valve opening degree of the first throttle valve to the opening degree on the closing side relative to the target valve opening degree when it is judged that the valve opening degree of the second throttle valve is the opening degree on the closing side relative to the predetermined set valve opening degree.