Abstract: An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

Abstract: An engine system is provided, which includes an engine, a swirl control valve, an EGR passage, an EGR gas adjusting mechanism, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder when it closes. When an engine load is at or below a given threshold, the controller controls the swirl control valve to close. While the engine load is the threshold or below, the controller controls the EGR gas adjusting mechanism such that, at a fixed engine speed, an increase rate of an EGR gas amount with respect to an increase in the engine load is lower in a first load range than in a second load range, the first load range being on a higher load side of the second load range and including the threshold.

Abstract: An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

Abstract: An engine system is provided, which includes an engine, a swirl control valve, an EGR passage, an EGR gas adjusting mechanism, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder when it closes. When an engine load is at or below a given threshold, the controller controls the swirl control valve to close. While the engine load is the threshold or below, the controller controls the EGR gas adjusting mechanism such that, at a fixed engine speed, an increase rate of an EGR gas amount with respect to an increase in the engine load is lower in a first load range than in a second load range, the first load range being on a higher load side of the second load range and including the threshold.

Abstract: An intake system of an engine supplies gas at least containing fresh air to each cylinder. The system includes an EGR passage that communicates with an internal space of a downstream intake passage and introduces some EGR gas into the downstream intake passage. The EGR passage includes a projected section in a substantially polygonal or cylindrical shape that is projected to the internal space of the downstream intake passage. The projected section is formed in such a shape that a projection length H1 in an outer circumferential surface on an upstream side is longer than a projection length H2 in an outer circumferential surface on a downstream side.

Abstract: An intake system of an engine supplies gas at least containing fresh air to each cylinder. The system includes an EGR passage that communicates with an internal space of a downstream intake passage and introduces some EGR gas into the downstream intake passage. The EGR passage includes a projected section in a substantially polygonal or cylindrical shape that is projected to the internal space of the downstream intake passage. The projected section is formed in such a shape that a projection length H1 in an outer circumferential surface on an upstream side is longer than a projection length H2 in an outer circumferential surface on a downstream side.

Abstract: A fuel control system of an engine is provided which controls, by using a tumble flow, a behavior of fuel directly injected into a combustion chamber formed inside a cylinder of the engine. The fuel control system includes a fuel injector for directly injecting the fuel into the combustion chamber, a tumble flow generator for generating the tumble flow within the combustion chamber, and a fuel injector controlling module for causing the fuel injector to inject the fuel at a first injection timing and then inject a smaller amount of fuel than an amount injected at the first injection timing, in a direction opposing a positive direction of the tumble flow at a second injection timing, the first injection timing designed to be in an intake stroke of the cylinder, the second injection timing designed to be in a latter half of the compression stroke of the cylinder.

Abstract: A control device of a multi-cylinder engine is provided. The device includes first and second auxiliary components. The first auxiliary component generates energy. The device includes an angular speed variation detecting device for detecting an angular speed variation of a crankshaft, and an auxiliary component control device for controlling drive loads of the first and second auxiliary components. When an engine load is low and the angular speed variation exceeds a predetermined threshold, the auxiliary component control device increases a total drive load of the auxiliary components. Here, if the drive load of the first auxiliary component is increasable, the drive load of the first auxiliary component is increased, and when this increase amount is insufficient, the drive load of the second auxiliary component is increased, whereas if the drive load of the first auxiliary component is not increasable, the drive load of the second auxiliary component is increased.

Abstract: A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body by using a coolant, and a controller for controlling a temperature of the coolant and changing the number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and expands the reduced-cylinder operating range to a higher engine load side as the coolant temperature becomes lower.

Abstract: A control device of a multi-cylinder engine is provided. The control device includes an auxiliary component and a valve stopping device having a locking mechanism for stopping an operation of at least one of intake and exhaust valves of a specific cylinder of the multi-cylinder engine according to an engine operating state. The control device includes an angular speed variation detecting device for detecting an angular speed variation of a crankshaft, an auxiliary component control device for controlling a drive load of the auxiliary component. In an all-cylinder operation, when an engine load is lower than a predetermined value and the detected angular speed variation exceeds a predetermined threshold, the auxiliary component control device performs an auxiliary component drive load increase control in which the drive load of the auxiliary component is increased to reduce the angular speed variation to be lower than the predetermined threshold.

Abstract: A fuel control system of an engine is provided which controls, by using a tumble flow, a behavior of fuel directly injected into a combustion chamber formed inside a cylinder of the engine. The fuel control system includes a fuel injector for directly injecting the fuel into the combustion chamber, a tumble flow generator for generating the tumble flow within the combustion chamber, and a fuel injector controlling module for causing the fuel injector to inject the fuel at a first injection timing and then inject a smaller amount of fuel than an amount injected at the first injection timing, in a direction opposing a positive direction of the tumble flow at a second injection timing, the first injection timing designed to be in an intake stroke of the cylinder, the second injection timing designed to be in a latter half of the compression stroke of the cylinder.

Abstract: A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body, and a controller for controlling the cooling mechanism and changing a number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and in a first reduced-cylinder range set within a high load part of the reduced-cylinder operating range, the controller improves a cooling performance of the cooling mechanism compared with that in a second reduced-cylinder range set within a low load part of the reduced-cylinder operating range.

Abstract: A method for controlling an engine includes, when the engine is operating within a particular range with comparatively low engine speed and high load, setting an effective compression ratio of 10:1 or above, retarding ignition timing by a predetermined amount and retarding the ignition timing within a first, relatively low engine speed range more than within a second, higher engine speed range, setting an injection mode of an injection valve to divided injections performed at least twice in a period from an intake stroke to an earlier-half stage of a compression stroke, performing, within the first engine speed range, a final injection in the earlier-half stage of the compression stroke, and performing, within the second engine speed range, the final injection in a late stage of the intake stroke and at least one injection other than the final injection in a middle stage of the intake stroke.

Abstract: A control device of a multi-cylinder engine is provided. The control device includes an auxiliary component and a valve stopping device having a locking mechanism for stopping an operation of at least one of intake and exhaust valves of a specific cylinder of the multi-cylinder engine according to an engine operating state. The control device includes an angular speed variation detecting device for detecting an angular speed variation of a crankshaft, an auxiliary component control device for controlling a drive load of the auxiliary component. In an all-cylinder operation, when an engine load is lower than a predetermined value and the detected angular speed variation exceeds a predetermined threshold, the auxiliary component control device performs an auxiliary component drive load increase control in which the drive load of the auxiliary component is increased to reduce the angular speed variation to be lower than the predetermined threshold.

Abstract: A control device of a multi-cylinder engine is provided. The device includes first and second auxiliary components. The first auxiliary component generates energy. The device includes an angular speed variation detecting device for detecting an angular speed variation of a crankshaft, and an auxiliary component control device for controlling drive loads of the first and second auxiliary components. When an engine load is low and the angular speed variation exceeds a predetermined threshold, the auxiliary component control device increases a total drive load of the auxiliary components. Here, if the drive load of the first auxiliary component is increasable, the drive load of the first auxiliary component is increased, and when this increase amount is insufficient, the drive load of the second auxiliary component is increased, whereas if the drive load of the first auxiliary component is not increasable, the drive load of the second auxiliary component is increased.

Abstract: An exhaust manifold has a plurality of branched exhaust passages connected to respective exhaust ports of individual cylinders; a plurality of first collector segments each of which joins the branched exhaust passages for the cylinders which are not adjacent in the exhaust order sequence; a plurality of middle exhaust passages connected to the downstream of the first collector segments, respectively; and a second collector segment that joins the middle exhaust passages. In at least low and middle speed ranges in a high load region of the engine, a valve opening time of an exhaust valve is changed according to the engine speed so that a predetermined amount of a valve overlap period is ensured and that negative pressure waves from exhaust pressure pulses reach an exhaust port during the valve overlap period in a plurality of engine speed ranges.

Abstract: A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body, and a controller for controlling the cooling mechanism and changing a number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and in a first reduced-cylinder range set within a high load part of the reduced-cylinder operating range, the controller improves a cooling performance of the cooling mechanism compared with that in a second reduced-cylinder range set within a low load part of the reduced-cylinder operating range.

Abstract: A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body by using a coolant, and a controller for controlling a temperature of the coolant and changing the number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and expands the reduced-cylinder operating range to a higher engine load side as the coolant temperature becomes lower.

Abstract: An engine has a geometric compression ratio of higher than 12, and includes an exhaust manifold, a variable exhaust valve timing mechanism, an ignition timing controller, and an effective compression ratio adjuster. The exhaust manifold has a plurality of branched exhaust passages connected to the respective exhaust ports of the individual cylinders; a plurality of first collector segments each of which joins the branched exhaust passages for the cylinders which are not adjacent in the exhaust order sequence; a plurality of middle exhaust passages connected to the downstream of the first collector segments, respectively; and a second collector segment that joins the middle exhaust passages.

Abstract: A method for controlling an engine includes, when the engine is operating within a particular range with comparatively low engine speed and high load, setting an effective compression ratio of 10:1 or above, retarding ignition timing by a predetermined amount and retarding the ignition timing within a first, relatively low engine speed range more than within a second, higher engine speed range, setting an injection mode of an injection valve to divided injections performed at least twice in a period from an intake stroke to an earlier-half stage of a compression stroke, performing, within the first engine speed range, a final injection in the earlier-half stage of the compression stroke, and performing, within the second engine speed range, the final injection in a late stage of the intake stroke and at least one injection other than the final injection in a middle stage of the intake stroke.