Abstract: An exhaust gas recirculation controlling apparatus suitable for an engine wth a turbocharger. An EGR valve which is provided in an EGR passage connecting an exhaust system passage and an intake system passage of the engine controls the amount of EGR. A vacuum adjustment valve controls the vacuum supplied from a vacuum source to the EGR valve. A valve device for cutting off the supply of vacuum in a vacuum range which is lower than the vacuum corresponding to at least the lower limitation value in the EGR controlling range with respect to the vacuum controlling characteristics of a vacuum adjustment valve is provided in the passage connecting the EGR valve and the vacuum adjustment valve such as to securely close the EGR valve when the running state of the engine is out of the EGR controlling range.

Abstract: A system for controlling the throttling of intake air and pressure of fuel injection in a diesel engine, including an intake air throttling mechanism in an intake air passage and a fuel injection apparatus in a swirl chamber. The fuel injection pressure of the fuel injection apparatus is variable. The intake air throttling mechanism is operated in accordance with predetermined operating parameters of the engine to reduce the fuel injection pressure when necessary.

Abstract: Disclosed herein is an internal combustion engine provided with an exhaust gas recirculation system of so-called back pressure control type. The exhaust gas recirculation system is provided with a vacuum line connecting a so-called EGR port with a vacuum operated flow control valve, and a modulator valve having a control chamber selectively opened to the vacuum line in response to the pressure of recirculated exhaust gas for controlling vacuum signal level of the flow control valve. The control chamber of the modulator is connected to another vacuum signal port located slightly above the EGR port.

Abstract: An exhaust gas recirculation system for use in an internal combustion engine includes an intake manifold having a riser portion serving as a heating source for an intake mixture charge, an exhaust gas recirculation passage running from an exhaust manifold to an intake system for introducing part of exhaust gases from the former to the latter, and a temperature-responsive valve provided in the intake manifold in such a position as to be able to detect the temperature of the riser portion for controlling the flow rate of the recirculation exhaust gases, in accordance with the temperature of the riser position. In this exhaust gas recirculation system, the flow rate of exhaust gases to be recirculated from the exhaust manifold to the intake system may be increased by one step, or two steps, as required, in response to the temperature of the riser portion, by means of a modified temperature responsive valve attached to the intake system.

Abstract: An ignition system for a spark-ignition type internal combustion engine comprising an ignition device capable of performing the spark timing control function, wherein in order to improve the engine torque, a temperature detecting element for detecting the temperature having an effect on the engine torque efficiency is provided in addition to the ignition device, so that the ignition device is actuated to advance the timing of the spark at a lower temperature as compared with that employed at a higher temperature in accordance with the temperature detected by the temperature detecting element.

Abstract: Disclosed is a butterfly valve opening degree setting device comprising a diaphragm apparatus. The diaphragm apparatus has a diaphragm, a vacuum chamber and a control rod connected to the diaphragm. The control rod is arranged so as to be engageable with the butterfly valve disposed in the duct. The vacuum chamber of the diaphragm apparatus is connected to the vacuum port formed on the inner wall of the duct. The butterfly valve is held open at a position wherein the peripheral edge of the butterfly valve faces the vacuum port.

Abstract: Disclosed is a throttle valve opening control device for use in an internal combustion engine. When the throttle valve is rapidly closed after completion of the warm-up of the engine, the throttle valve is temporarily held at a first opening degree which is greater than an idling opening degree and, then, the throttle valve is gradually returned to its idling position. Contrary to this, when the throttle valve is rapidly closed before completion of the warm-up of the engine, the throttle valve is temporarily held at a second opening degree which is greater than said first opening degree and, then, the throttle valve is gradually returned to its idling position.

Abstract: Disclosed is a throttle valve opening control device for use in an internal combustion engine. When the throttle valve is rapidly closed after completion of the warm-up of the engine, the throttle valve is temporarily held during a first length of time at a predetermined opening degree which is greater than an idling opening degree and, then, the throttle valve is gradually returned to its idling position. Contrary to this, when the throttle valve is rapidly closed before completion of the warm-up of the engine, the throttle valve is temporarily held at the predetermined opening degree during a second length of time, which is longer than said first length of time and, then, the throttle valve is gradually returned to its idling position.

Abstract: An ignition system for a spark-ignition type internal combustion engine comprising an ignition device capable of performing the spark timing control function, wherein in order to improve the engine torque, a temperature detecting element for detecting the temperature having an effect on the engine torque efficiency is provided in addition to the ingition device, so that the ignition device is actuated to advance the timing of the spark at a lower temperature as compared with that employed at a higher temperature in accordance with the temperature detected by the temperature detecting element.

Abstract: An ignition system for a spark-ignition type internal combustion engine comprising an ignition device capable of performing the spark timing control function, wherein in order to improve the engine torque, a temperature detecting element for detecting the temperature having an effect on the engine torque efficiency is provided in addition to the ignition device, so that the ignition device is actuated to advance the timing of the spark at a lower temperature as compared with that employed at a higher temperature in accordance with the temperature detected by the temperature detecting element.

Abstract: An ignition timing control apparatus for an internal combustion engine which includes two diaphragms, each of which is selectively connected through a change-over valve to a respective one of two vacuum ports in the passage of carburetor. One of the ports is just above the upper edge of a throttle valve in the fuel passage when the throttle valve is in its engine idling position. The other port is upstream of the one port and is adjacent the upper edge of the throttling valve when the engine is in a partly loaded condition. The change-over valve is controlled in response to the temperature of the engine cooling water.

Abstract: An ignition system for a spark-ignition type internal combustion engine comprising an ignition device capable of performing the spark timing control function, wherein in order to improve the engine torque, a temperature detecting element for detecting the temperature having an effect on the engine torque efficiency is provided in addition to the ingition device, so that the ignition device is actuated to advance the timing of the spark at a lower temperature as compared with that employed at a higher temperature in accordance with the temperature detected by the temperature detecting element.