Abstract: A pressure-elevating type fuel injecting system pressurizes high pressure fuel from a pressure accumulating chamber using a pressure-elevating mechanism and injects the pressure-elevated fuel into combustion chambers by injectors. The pressure-elevating type fuel injecting system comprises a target fuel injection quantity setting unit which sets a target fuel injection quantity, a time difference setting unit which sets a time difference between a timing for opening an injector electromagnetic valve and a timing for operating an pressure-elevating mechanism electromagnetic valve, an initial fuel injection quantity calculating unit calculating an initial fuel injection quantity on the basis of a time-dependent variation of fuel pressure and the time difference, and a final injection period setting unit which calculates an operation period of the injector electromagnetic valve, on the basis of a final fuel injection quantity and the time-dependent variation of the pressure of the pressure-elevated fuel.

Abstract: By setting a switching timing of switching means that connects either one of a high pressure fuel source and a low pressure fuel source to an injector earlier than a point of time when an injector finishes a high pressure fuel injection, leak fuel or return fuel is reduced and an engine load is reduced and therefore mileage is improved.

Abstract: An ECU preliminarily obtains a target supercharging pressure determined based on an engine rotational speed and an engine load, and stores the target supercharging pressure value. The ECU commands a flow passage area changing unit to set an exhaust gas flow passage area to the maximum flow passage area or the minimum flow passage area, and judges the abnormality of a supercharger by comparing supercharging pressure detected by a supercharging pressure sensor and the stored target supercharging pressure.

Abstract: In a common rail system comprised of a first accumulator storing high-pressure fuel and a second accumulator storing low-pressure fuel, additional fuel is injected when a fuel pressure in a fuel passage or in the second accumulator (low inlet pressure of an injector) is reduced to a low pressure approximate to the pressure of the low-pressure fuel stored in the second accumulator after a switching valve is operated for disconnection from the fuel passage (switching valve drive signal OFF) at a point in time when a main injection control device finishes the injection of fuel (injector drive signal OFF) or after the main injection control device finishes the injection of fuel. This keeps the fuel pressure as low as possible during post injection to prevent the fuel from adhering to the wall surfaces of cylinder liners.

Abstract: The present invention relates to an EGR control unit and EGR control method for controlling an EGR adjusting apparatus, and it is an object of the invention to calculate an EGR rate at a low cost and to control an operation of the EGR apparatus with high accuracy. The EGR control unit is made up of temperature detecting devices detect in-passage temperature at least two of an intake passage, an atmospheric air introduction passage located on the upstream side of the intake passage and communicated with the atmosphere and an EGR passage, an actual EGR rate calculating device for calculating a rate of an exhaust gas to an intake gas in an internal combustion engine on the basis of information on temperatures detected by the temperature detecting devices, and an EGR controller for controlling the EGR adjusting device through the use of the actual EGR rate calculated by the actual EGR rate calculating device.

Abstract: A common-rail injection system includes a first accumulator of high pressure and a second accumulator of low pressure. The common-rail injection system includes a post injection control device for injecting additional low-pressure fuel from the second accumulator through a fuel injection nozzle after main fuel is injected. The post injection control device injects the additional fuel the injection terminates at a first timing when the fuel pressure in either fuel passage or second accumulator lowers to a predetermined value lower than that of the high-pressure fuel or at a second timing when an exhaust stroke of the engine is completed, whichever earlier.

Abstract: In a common rail system comprised of a first accumulator storing high-pressure fuel and a second accumulator storing low-pressure fuel, additional fuel is injected when a fuel pressure in a fuel passage or in the second accumulator (low inlet pressure of an injector) is reduced to a low pressure approximate to the pressure of the low-pressure fuel stored in the second accumulator after a switching valve is operated for disconnection from the fuel passage (switching valve drive signal OFF) at a point in time when a main injection control device finishes the injection of fuel (injector drive signal OFF) or after the main injection control device finishes the injection of fuel. This keeps the fuel pressure as low as possible during post injection to prevent the fuel from adhering to the wall surfaces of cylinder liners.

Abstract: A controller (8) of an accumulator fuel-injection apparatus opens a selector valve (5) for injection rate switching for a short time between auxiliary injection and main injection, the selector valve controlling high-pressure fuel supply from a high-pressure accumulator (3) to a fuel passage (10a) on the downstream side of a check valve (32), whereby a fuel pressure higher than an auxiliary injection pressure and lower than a main injection pressure is formed in the fuel passage on the downstream side of the selector valve (5). By opening, in this state, an on-off valve (7) for injection timing control to start the main injection, a proper pressure higher than the auxiliary injection pressure and lower than the subsequent main injection pressure is established in the initial stage of main injection, improving fuel economy and exhaust-gas characteristic.

Abstract: An accumulator type fuel injection system adapted to prevent engine trouble by making a judgement that fuel injection rate switching change-over valves provided correspondingly to fuel injection nozzles in cylinders, a valve for controlling the pressure in a low-pressure accumulator or means for detecting fuel pressures in accumulators gets out of order, and carrying out when any of these parts break down a control operation of a limp-home mode in which a region of an operation of an engine is limited. To provide such an accumulator type fuel injection system, a control means 8 is formed so that, when a judgement that first control valves 5, a second control valve 34 or pressure sensors 3a, 4a for detecting the fuel pressures in the respective accumulators get out of order is given, the control means 8 sets a discharge pressure of a fuel pump 1 not higher than a permissible pressure in a second accumulator 4, and injects a fuel from fuel injection nozzles 9.

Abstract: An accumulator type fuel injection system adapted to prevent engine trouble by making a judgement that fuel injection rate switching change-over valves provided correspondingly to fuel injection nozzles in cylinders, a valve for controlling the pressure in a low-pressure accumulator or means for detecting fuel pressures in accumulators gets out of order, and carrying out when any of these parts break down a control operation of a limp-home mode in which a region of an operation of an engine is limited. To provide such an accumulator type fuel injection system, a control means 8 is formed so that, when a judgement that first control valves 5, a second control valve 34 or pressure sensors 3a, 4a for detecting the fuel pressures in the respective accumulators get out of order is given, the control means 8 sets a discharge pressure of a fuel pump 1 not higher than a permissible pressure in a second accumulator 4, and injects a fuel from fuel injection nozzles 9.

Abstract: An accumulator fuel injection system for controlling an injection rate according to the operating state of an engine comprises: a first accumulation chamber 2 for containing high-pressure fuel supplied by a fuel supply pump 1; a first electromagnetic valve device 4 provided in a fuel passage 30, which connects the first accumulation chamber 2 with a fuel injection valve 8, the first electromagnetic valve switching the fuel passage 30 between a connected state or a disconnected state; a branch passage 32 branched from the fuel passage 30 at downstream side of the first electromagnetic device 4, the branch passage 32 having sufficiently lower constant fuel pressure than fuel pressure in the first accumulation chamber 2; and a second electromagnetic valve device 9 provided in a fuel return passage 33 connecting the fuel injection valve 8 with a fuel tank 10, the second electromagnetic valve device 9 switching fuel, which is injected from the fuel injection valve 8, between an injected state and an uninjected sta

Abstract: A fuel injector to be used with a low-pressure fuel source and a high-pressure fuel source to provide a two-stage fuel injection has superior responsiveness of fuel pressure control and ease of mounting to an engine.

Abstract: An accumulator type fuel injection system adapted to prevent engine trouble by making a judgement that fuel injection rate switching change-over valves provided correspondingly to fuel injection nozzles in cylinders, a valve for controlling the pressure in a low-pressure accumulator or means for detecting fuel pressures in accumulators gets out of order, and carrying out when any of these parts break down a control operation of a limp-home mode in which a region of an operation of an engine is limited. To provide such an accumulator type fuel injection system, a control means 8 is formed so that, when a judgement that first control valves 5, a second control valve 34 or pressure sensors 3a, 4a for detecting the fuel pressures in the respective accumulators get out of order is given, the control means 8 sets a discharge pressure of a fuel pump 1 not higher than a permissible pressure in a second accumulator 4, and injects a fuel from fuel injection nozzles 9.

Abstract: After an engine has been started, a controller 8 of a fuel injection system opens an injection rate switching change-over valve 5 for a period of time not less than a fuel injection period until the time a fuel pressure in a low pressure accumulator 4 connected to the portion of a fuel passage 10a which is on the downstream side of the change-over valve 5 has reached a set level, whereby a fuel injection starting delay ascribed to a fuel pressure decrease in the second accumulator can be prevented.

Abstract: During a transitional operation of an engine in which an engine load is changed suddenly from a high load to a low load, a control operation for extending an opening period of a change-over valve which is adapted to switch a low-pressure accumulator and a high-pressure accumulator from one to the other during a fuel injection operation is carried out to increase a flow rate of a fuel supplied to the low-pressure accumulator and thereby reduce the pressure in the high-pressure accumulator, whereby a response delay of the fuel pressure in the high-pressure accumulator is minimized.

Abstract: A multiple step valve opening control system, particularly for an EGR control valve unit, having a plurality of valve lifts. The system comprises a valve member for opening a fluid passage in multiple steps, a first piston slidably housed in a housing, a second cylinder substantially coaxial with the first piston, a second piston fitted in the second cylinder and coupled to the valve member, and a first piston stroke regulating member which is moved selectively to a first position for regulating an allowable displacement of the first piston to a first predetermined extent (l.sub.1) or to a second position for regulating the allowable displacement of the first piston to the first predetermined first extent (l.sub.1) plus a third predetermined extent (l.sub.3). By changing the position of the first piston displacement regulating member, the valve member is opened by various valve lifts.

Abstract: A projection positioned in the center of a concave section of a toroidal combustion chamber is divided into a section with a steep slope extending from the bottom to the head surface and a section with a gentle slope. The head surface is in the form of a flattened conical trapezoid. Because of its shape, the projection makes it possible for the air which is close to the center section to flow close to the surface of a side wall of the concave section. The air which had been at the center section is added to the amount of air supplied for combustion and is mixed with the fuel in the vicinity of the surface of the side wall of the concave section. By setting the angle at which the air flows along the side wall surface (re-entrant angle) in the combustion chamber, the flow of the air close to the side wall surface is made turbulent, which improves the agitation of the fuel.

Abstract: A variable-volume turbocharger device comprises at least two exhaust gas passages (A), (B) different in the flow characteristics, divided by a partition wall (20) provided in a turbine housing (18), and two valve members (34a), (34b) which are actuated so as to open and shut the exhaust gas passages (A), (B). The valve members (34a), (34b) each are actuated to open and shut in response to the speed and load of an engine or the likes, whereby either one of the exhaust gas passages (A), (B) or both of them are opened to provide at least three turbine flow characteristics. An exhaust gas turbine (12) can be thereby operated with remarkably good efficiency suitably to the operating state of the engine.

Abstract: A variable-volume turbocharger device comprises at least two exhaust gas passages (A), (B) different in the flow characteristics, divided by a partition wall (20) provided in a turbine housing (18), and two valve members (34a), (34b) which are actuated so as to open and shut the exhaust gas passages (A), (B). The valve members (34a), (34b) each are actuated to open and shut in response to the speed and load of an engine or the likes, whereby either one of the exhaust gas passages (A), (B) or both of them are opened to provide at least three turbine flow characteristics. An exhaust gas turbine (12) can be thereby operated with remarkably good efficiency suitable to the operating state of the engine.

Abstract: A variable-volume turbocharger device comprises at least two exhaust gas passages (A), (B) different in the flow characteristics, divided by a partition wall (20) provided in a turbine housing (18), and two valve members (34a), (34b) which are actuated so as to open and shut the exhaust gas passages (A), (B). The valve members (34a), (34b) each are actuated to open and shut in response to the speed and load of an engine or the likes, whereby either one of the exhaust gas passages (A), (B) or both of them are opened to provide at least three turbine flow characteristics. An exhaust gas turbine (12) can be thereby operated with remarkably good efficiency suitably to the operating state of the engine.