Abstract: An air assist device comprising a plurality of air intake ports formed in the inner wall of an intake duct around a throttle valve. An assist air chamber is formed above the air intake ports and an assist air outflow port is formed in the assist air chamber. To allow the liquid substances flowing from the air intake ports to the assist air chamber to flow down to the assist air outflow port by gravity, the bottom wall of the assist air chamber descends toward the assist air outflow port.

Abstract: An air assist device comprising a plurality of air intake ports formed in the inner wall of an intake duct around a throttle valve. The assist air is taken in from the air intake ports. The amount of opening of the air intake ports is controlled by the outer peripheral end face of the throttle valve. The cross-sectional shapes of the air intake ports are made easily formed circular cross-sectional shapes.

Abstract: A method or an apparatus controls a continuously variable valve timing mechanism of an internal combustion engine to continuously and variably control the timing of an intake valve according to atmospheric pressure. The method or apparatus reads an engine revolution speed NE, an engine load GN, and an atmospheric pressure PA, refers to a map according to the atmospheric pressure PA, to find an atmospheric pressure correction coefficient Kpa, which is 1.0 at low altitudes with PA=760 mmHg and decreases as the altitude increases, i.e., as the atmospheric pressure PA decreases, calculates a corrected engine load GNpa as GNpa.rarw.GN/Kpa, and refers to a map according to the corrected engine load GNpa and engine revolution speed NE, to find a target displacement to be imposed on the open/close timing of the intake valve.

Abstract: An apparatus for detecting the quantity of intake air to be compared with a reference quantity is arranged in an internal combustion engine having a mechanism for continuously varying the open/close timing of at least one of the intake valves and the exhaust valves. The apparatus has a unit for detecting a load of the engine and a unit for detecting an actual quantity of intake air according to the detected load and valve timing that is dependent on the detected load.

Abstract: The warming up control device according to the present invention determines precisely whether the temperature of the catalytic converter of the internal combustion engine has reached the activating temperature of the catalyst after the engine starts, The device estimates the heat amount transferred from the exhaust gas the catalytic converter based on the amount of the fuel supplied to the engine, and calculates the total heat amount transferred to the catalytic converter after the engine starts. The device determines that the temperature of the catalytic converter reaches the activating temperature of the catalyst when the calculated total heat amount reaches a predetermined value. Since the completion of the warming up of the catalytic converter is precisely determined, the warming up operation of the catalyst, such as the ignition timing retardation, can be terminated at a proper time, thus an unnecessary increase in fuel consumption and a deterioration in the engine performance can be avoided.

Abstract: A valve timing control device for an internal combustion engine comprises a variable valve timing mechanism capable of varying a valve overlap period. Fuel injection can be stopped in at least one predetermined engine operating condition and an optimal value of the valve overlap period in the current engine operating condition can be determined, on the basis of current engine speed, load, and temperature. The variable valve timing mechanism can be controlled such that the valve overlap period becomes larger than the optimal value when fuel injection is stopped. Accordingly, in the idle condition when the engine has not warmed up, intake air is heated sufficiently, by the valve overlap period, to more than the optimal value and an engine stall at this time is completely prevented by increasing the amount of intake air.

Abstract: A valve timing control device for an internal combustion engine. The device comprises a variable valve timing mechanism capable of varying a valve overlap period; an increasing unit capable of increasing an amount of intake air in at least the idle condition; a determination unit for determining an optimal value of the valve overlap period in the current engine operating condition, on the basis of current engine speed, load, and temperature; a first controller for controlling the variable valve timing mechanism such that the valve overlap period becomes larger than the optimal value in an idle condition when the engine has not warmed up; and a second controller for controlling the increasing unit such that an amount of intake air is increased in an idle condition when the engine has not warmed up.

Abstract: A valve timing control device for an internal combustion engine. The device comprises first determination means for determining a first optimal value of the valve overlap period in the current engine operating condition, on the basis of the current engine speed and load, second determination means for determining a second optimal value of the valve overlap period in the current engine operating condition by reducing the first optimal value when the engine has not warmed up, and valve overlap period control means for controlling a valve overlap period using the first optimal value when the current degree of opening of the throttle valve is larger than a predetermined value, even if the engine has not warmed up.

Abstract: A fuel injection timing control device for an internal combustion engine. The device comprises a fuel injector for injecting fuel into the intake port of an engine cylinder and an fuel injection end-timing control system for controlling the fuel injection end-timing of the fuel injector so as to advance gradually, from a first crank angle in the intake stroke to a second crank angle before the intake stroke, according to the engine operating condition. Accordingly, when the fuel injection timing is changed, the amount of fuel which sticks or adheres in the intake port is gradually increased by a small amount, at each fuel injection, so that the air-fuel ratio of the mixture does not become so lean the drivability of the vehicle is deteriorated.

Abstract: A valve timing control device for an internal combustion engine. The device comprises first determination means for determining a first optimal value of the valve overlap period in the current engine operating condition, on the basis of the current engine speed and load, second determination means for determining a second optimal value of the valve overlap period in the current engine operating condition by reducing the first optimal value when the engine has not warmed up, and valve overlap period control means for controlling a valve overlap period using the first optimal value, or such that it varies gradually from the second optimal value to the first optimal value, when the current degree of opening of the throttle valve is larger than a predetermined value, even if the engine has not warmed up.

Abstract: The variable valve timing control device according to the present invention controls the valve timing of the intake valves of the engine based on the optimum valve timing at the full load operation of the engine. Namely, the variable valve timing control device of the present invention determines the valve timing in accordance with the combination of the present engine load and the present engine speed in such a manner that the deviation of the valve timing from the optimum valve timing when the engine is operated in full load at the present speed does not exceed a predetermined maximum allowable value. Since the valve timing of the engine is always set within a range determined by the maximum allowable deviation from the optimum valve timing for the full load operation, when the engine is accelerated to the full load condition the amount of the change, i.e., the amount of the operation of the variable valve timing control device is kept always within the range determined by the maximum allowable deviation.

Abstract: A vehicular engine speed controller for keeping the engine speed constant while preventing the overrunning of the engine. The vehicle includes a propeller shaft connected to driving wheels and a torsional damper for connecting the propeller shaft with the engine drive shaft. The controller comprises a detector for detecting a value corresponding to engine speed, and an injection control device for controlling injectors, based on the detected value from the detector. The control device stores a first and second determining values (Da and Db). The control device halts fuel supply from the injector when the detected value exceeds the first value (Da), and resumes fuel supply when the detected value becomes below the second value (Db).

Abstract: A charging control apparatus including means for shortening a running-up period of the second turbocharger with an exhaust bypass valve when an instant engine speed is low, so that torque shock during the transition from one-turbocharger-operation to two-turbocharger-operation is decreased. During rapid acceleration at high engine speeds, an exhaust switching valve is opened at once. Further, the reference engine speed and the reference intake air quantity for switching to two-turbocharger-operation are varied in accordance with the gear shift position, so that an optimum switching to two-turbocharger-operation is obtained.

Abstract: A charging control apparatus including means for shortening a running-up period of the second turbocharger with an exhaust bypass valve when an instant engine speed is low, so that torque shock during the transition from one-turbocharger-operation to two-turbocharger-operation is decreased. During rapid acceleration at high engine speeds, an exhaust switching valve is opened at once. Further, the reference engine speed and the reference intake air quantity for switching to two-turbocharger-operation are varied in accordance with the shift gear position, so that an optimum switching to two-turbocharger-operation is obtained.

Abstract: A charging pressure control apparatus including a first duty control solenoid valve for controlling the opening degree of an exhaust bypass valve to thereby control a charging pressure during "one-turbocharger-operation", and a second duty control solenoid valve for controlling the opening degree of a waste gate valve to thereby control a charging pressure during "two-turbocharger-operation". The operating conditions at high altitudes of the first duty control solenoid valve and the second duty control solenoid valve are made different from those at low altitudes so that the power characteristic of the turbocharged engine is as good at high altitudes as at low altitudes.

Abstract: An EGR apparatus includes an EGR conduit, an EGR valve, a first passage connecting a portion of an intake conduit downstream of a throttle valve and the EGR valve, and a second passage connecting a portion of the intake conduit upstream of the throttle valve and a medium portion of the first passage. A two-way solenoid valve is installed in the first passage between the intake conduit and a connecting portion where the first passage and the second passage join. Further, a fixed throttle is disposed in the second passage. By removing a VCV of a conventional EGR apparatus from the EGR apparatus and by replacing a three-way VSV of the conventional apparatus with a combination of the two-way solenoid valve and the fixed throttle, a problem of non-cutting of EGR, which can occur in the conventional apparatus, does not occur in the EGR apparatus of the invention.

Abstract: An internal combustion engine with a dual turbocharger system includes an air bypass conduit connecting a downstream portion of a first turbocharger compressor with an upstream portion of a second turbocharger compressor so that the length of the air bypass conduit is relatively long. When a throttle is rapidly closed, an air bypass valve installed in the air bypass conduit is opened and the compressed air downstream of the throttle valve is returned to the upstream of the turbocharger compressor to suppress occurrence of a surging at the turbocharger compressor. Since the air bypass conduit is relatively long, the compressed and circulated air is effectively cooled when flowing through the air bypass conduit and melting of an impeller of the turbocharger compressor is prevented.

Abstract: An evaporated fuel discharge suppressing apparatus includes a main purge conduit and a bypass purge conduit. The main purge conduit connects a canister and an intake conduit of an engine downstream of a throttle valve, and a purge control solenoid valve is installed in the main purge conduit. The bypass purge conduit bypasses the purge control solenoid valve. Even if the purge control solenoid valve sticks in a closed position, evaporated fuel adsorbed by the canister can flow into the intake conduit of the engine through the bypass purge conduit so that the evaporated fuel in the canister is not discharged into the atmosphere.

Abstract: An internal combustion engine with a dual turbocharger system which includes an engine, a first and a second turbocharger arranged in parallel with each other, an intake switching valve located downstream of a compressor of the second turbocharger, an exhaust switching valve located downstream of a turbine of the second turbocharger. The engine operation is changed between a "one-turbocharger-operation" wherein only the first turbocharger is operated and a "two-turbocharger-operation" wherein both the first turbocharger and the second turbocharger are operated. Change from the "one-turbocharger-operation" to the "two-turbocharger-operation" is performed on the basis of an intake air quantity, and change from the "two-turbocharger-operation" to the "one-turbocharger-operation" is performed on the basis of an engine speed. This type of change suppresses a torque shock at shift changing during acceleration and improves the drive feeling.

Abstract: An internal combustion engine with a dual turbocharger system includes an engine, a first turbocharger and a second turbocharger arranged in parallel with each other, an intake switching valve located downstream of a compressor of the second turbocharger, and an exhaust switching valve located downstream of a turbine of the second turbocharger. At large intake air quantities, both turbochargers are operated, while at small to medium intake air quantities only the first turbocharger is operated. At "one-turbocharger-operation", when the engine load is low, the intake switching valve is opened, while the exhaust switching valve is maintained closed. Thus, at small to medium intake air quantities and low engine loads, the intake flow can be introduced through both the compressor of the first turbocharger and the compressor of the second turbocharger. As a result, flow resistance is decreased and acceleration response from low engine loads is improved.