Abstract: A power transmission device for a motor vehicle having an engine with a crankshaft and a transmission with a transmission input shaft, comprises spiral spring assembly which provides a torque transmission connection between the crankshaft and the transmission input shaft. The assembly includes a plurality of spiral springs operative to be deformed responsive to torsional force applied thereto during the torque transmission. A vibration damper is mounted to damp vibration caused by the above mentioned torque transmission.

Abstract: In order to avoid the formation of smoke and HC when the compression ratio of a swirl chamber type Diesel engine is lowered either by design or by operation in rarified atmospheres, the fuel injector is located on one side of the center axis of the swirl chamber so as to maximize the distance for which the injected fuel can travel before contacting a wall of the chamber and the auxiliary transfer port through which a fraction of the injected fuel is fed to the main combution chamber is arranged so that the axis thereof intersects the axis of the fuel injector and therefore the trajectory along which fuel is injected, at a point defined within the swirl chamber per se and on the opposite side of the center axis with respect to the fuel injector.

Abstract: In order to promote a good flame dispersion within the combustion chamber of a swirl chamber type Diesel engine, a shaped recess formed in the piston crown is arranged to have a trench portion into which the flame from the swirl chamber is injected and mirror image flame dispersion portions on either side of the trench which terminates at the periphery of the piston crown. This arrangement inhibits the formation of secondary flame flows which tend impede desirable patterns within the flame disportion portions and simultaneously enlarges the dispersion area. In addition, careful selection of the dimensions of the transfer port which interconnects the swirl chamber and the main combustion chamber, and the various sections of the shaped recess, promotes further reductions in HC and smoke emissions.

Abstract: An interconnecting slot is formed between a main transfer port (heated by the passage of hot gases during an expansion phase) and an auxiliary transfer passage (cooled by the passage of non atomized fuel injected into the swirl chamber with which the main and auxiliary ports are associated) to prevent thermal stress damage which would otherwise be apt to occur.

Abstract: A fuel injection pump serves to periodically inject fuel into an internal combustion engine. A movable control member serves to determine the quantity of fuel injected during each fuel injection stroke in accordance with the position of the control member. A permanent magnet is movable together with the control member. A stationary magnetically-permeable member serves to conduct magnetic flux generated by the permanent magnet. The magnetic flux conducted by the magnetically permeable member depends on the position of the control member. A Hall element unit serves to sense the conducted magnetic flux and generate a first signal indicative of the actual position of the control member. A second signal indicates a desired position of the control member. A device, responsive to the first and second signals, serves to adjust the actual position of the control member to the desired position thereof.

Abstract: A first plunger pump serves to inject fuel into the combustion chamber of an internal combustion engine during first periodical compression strokes as the crankshaft of the engine rotates. A second plunger pump serves to inject fuel into the combustion chamber during second periodical compression strokes as the crankshaft rotates. The maximum fuel injection quantity during each second compression stroke of the second plunger pump is smaller than that during each first compression stroke of the first plunger pump. A sensor detects load on the engine. A mechanism serves to advance the timing of the first compression strokes relative to that of the second compression strokes with respect to the rotational angle of the crankshaft as the detected engine load increases. The characteristic curve of the rate of the sum of the fuel injections effected by the first and second plunger pumps with respect to the rotational angle of the crankshaft can vary in accordance with the engine load.

Abstract: An engine cooling system is disclosed for use with an internal combustion engine including first and second engine banks arranged with a V-angle, first and second cylinder units arranged in the first and second engine banks, respectively, the second cylinder unit being disabled under low load conditions. An engine coolant is circulated from a radiator through a cooling jacket disposed in the first engine bank to a cooling jacket disposed in the second engine bank and hence to the radiator.

Abstract: An internal combustion engine is disclosed which includes first and second cylinder units each having at least one cylinder, and a control unit responsive to engine load for rendering the first and second cylinder units active at high load conditions and rendering the second cylinder unit inactive when the engine load is below a predetermined value. A rapid acceleration detector is provided which is responsive to rapid engine acceleration for causing the control unit to render the first and second cylinder units active regardless of the engine load.

Abstract: An internal combustion engine is disclosed which includes first and second cylinder units each including at least one cylinder, a carburetor with first and second induction passages each having therein a throttle valve rotatable in phase with the other, and first and second intake passages connecting the first and second induction passage to the first and second cylinder units, respectively. The first and second intake passages are communicated near their upstream end. A swing valve is provided which is normally placed in a first position interrupting communication between the first and second intake passages and rotatable to a second position interrupting communication between the second induction passage and the second intake passage. Means are provided for rotating the swing valve to the second position at low load conditions.

Abstract: An internal combustion engine is disclosed which includes first and second cylinder units each including at least one cylinder, means for cutting off the supply of air and fuel to the second cylinder unit so as to render it inactive when the engine load is below a given value, a three-way catalytic converter for purifying the exhaust from the cylinders, a sensor exposed to the exhaust from the cylinders to provide a signal indicative of the air/fuel ratio at which the engine is operating, and means responsive to the signal from the sensor for controlling the fuel supplied to the engine to maintain the stoichiometric air/fuel ratio. Means is provided for introducing a predetermined amount of air into the second cylinder unit.

Abstract: An internal combustion engine is disclosed which includes active and inactive cylinders, a load detector adapted to provide a low load indicative signal when the engine load is below a predetermined value, first means responsive to the low load indicative signal for cutting off the flow of air to the inactive cylinders, and second means for supplying a controlled amount of fuel into the active and inactive cylinders so as to achieve a somewhat lean air-fuel mixture therein. The second means is responsive to the low load indicative signal for cutting off the supply of fuel to the inactive cylinders and increasing the amount of fuel supplied to the active cylinders so as to achieve a somewhat rich air-fuel mixture therein. Third means is provided for monitoring the oxygen content of the exhaust from the engine to control the second means so that the fuel supplied to the engine is correct to maintain the stoichiometric air/fuel ratio.

Abstract: An internal combustion engine is disclosed which comprises first and second cylinder units each including at least one cylinder, pulse generator means for generating, in synchronism with engine rotation, a fuel injection pulse signal of pulse width proportional to the rate of air flow to said engine, and first and second fuel supply means responsive to the fuel injection pulse signal for supplying, into the first and second cylinder units, respectively, a controlled amount of fuel corresponding to the duty ratio of the fuel injection pulse signal. Control means is provided for cutting off the fuel injection pulse signal to the second fuel supply means when the engine load is below a reference level increasing with an increase in engine temperature except when the engine speed is below a given level at open throttle conditions.

Abstract: An internal combustion engine is disclosed which includes a plurality of cylinders split into first and second groups and operates in a split cylinder mode under low engine load conditions where the second group of cylinders are held suspended. Means is provided for holding the combustion chambers of the second group of cylinders in communication with the exhaust passage during a split cylinder mode of operation.

Abstract: An internal combustion engine is disclosed which includes active cylinders being always active and inactive cylinders being inactive when the engine load is below a predetermined value. The engine has an intake passage divided into first and second branches connected to active and inactive cylinders, respectively. The second branch is provided near its inlet with a stop valve and is connected through an EGR valve to the engine exhaust passage and also through an air valve to air source. A sensor is located in the exhaust passage for providing a feedback signal to ensure that the fuel supplied to the engine is maintained at a desired air/fuel ratio. Control means is provided to close the stop valve, open the EGR valve, and cut off the flow of fuel for the inactive cylinders. Means is provided to close the EGR valve, open the air valve, and determined the amount of fuel to the engine regardless of the feedback signal from the sensor under extremely low load conditions.

Abstract: An internal combustion engine is disclosed which includes active cylinders being always active and inactive cylinders being inactive when the engine is below a predetermined value. The engine has an exhaust passage divided by a partition into first and second branches leading from the active and inactive cylinders. The second branch is connected through an EGR passage with the inactive cylinders at low load conditions. An exhaust gas sensor is provided in a through-hole formed in the partition at a position downstream of the opening of the EGR passage for monitoring one content of the engine exhaust to provide a signal indicative of the air/fuel ratio. The second branch has a volume, upstream of the opening of the EGR passage, larger than the stroke volume of the inactive cylinders.

Abstract: Under light load condition wherein only selected cylinders are fired or operate, low temperature exhaust gas gathering in an exhaust chamber for the unused cylinders is introduced into an intake chamber for the firing cylinders thereby to allow the firing cylinders to produce a less amount of NO.sub.x.

Abstract: An internal combustion engine is disclosed which includes a plurality of cylinders split into first and second groups, an intake passage provided therein with a throttle valve and bifurcated downstream of the throttle valve into first and second branches, the first branch communicating with the first group of cylinders, the second branch communicating with the second group of cylinders, and an EGR passage for recirculation of exhaust gases into the second branch. The second branch is provided therein with a stop valve and the EGR passage is provided therein with an EGR valve. Control means is provided for causing the EGR valve to open gradually after the stop valve is closed when the engine is shifted from its full cylinder mode to its split cylinder mode and for holding the stop valve open until the pressure in the second branch falls to a level equal to that in the first branch when the engine is shifted from its split cylinder mode to its full cylinder mode.

Abstract: A spark ignition fuel injection reciprocatory internal combustion engine with dual induction system is provided which has within a cylinder head a primary intake port passage to direct air charge into a cylinder to swirl therein and a secondary intake port passage to direct air charge into the cylinder in such a direction as to impede and reduce the swirling motion of the air charge issuing from the primary intake port passage. An intake valve, including a valve stem and a valve head, is reciprocably mounted within the cylinder head, and an annular wall or tube is fixedly positioned in a bore in the cylinder head. The primary intake port passage communicates with the exterior of this tube and the secondary intake port passage communicates with the interior of the tube. This tube extends to a position closely adjacent to, or in engagement with, the valve head of the intake valve when the valve is in the closed position.

Abstract: A spark ignition reciprocatory internal combustion engine with dual induction system is provided which has within a cylinder head a primary induction passage or a primary intake port passage to direct fluid charge into a cylinder to swirl therein and a secondary induction passage or a secondary intake port passage to direct fluid charge into the cylinder in such a direction as to impeded and reduce the swirling motion of the first fluid charge to provide a low "swirl ratio" within the cylinder, thereby to maintain the volumetric efficiency of the engine at a sufficiently high level. A primary throttle valve is provided to control the quantity of fluid charge entering into the primary induction passage and a secondary throttle valve is provided to control the quantity of fluid charge entering into the secondary induction passage.

Abstract: An internal combustion engine is disclosed which comprises a plurality of cylinders split into first and second groups, means responsive to engine low load conditions for cutting off flow of fuel and fresh air to the second group of cylinders, an exhaust passage provided at its downstream end with a catalyzer, a partition extending through the exhaust passage to the vicinity of the catalyzer to divide the exhaust passage into two passages, one connecting with the first group of cylinders, the other connecting with the second group of cylinders, an EGR passage bypassing the second group of cylinders for exhaust gas recirculation, and an EGR valve provided in the EGR passage and adapted to open the same in response to engine low load conditions.