Abstract: In a vehicle driveability evaluation system, an engine is coupled to a dynamic dynamometer which is capable of changing a load torque and a speed in a very short time. A control unit controls the dynamic dynamometer so that the load torque and the speed of the dynamometer simulate the load and the speed of the engine when it is mounted on an actual vehicle. The driveability evaluation test is performed by operating the engine while simulating various running conditions of the vehicle by the dynamic dynamometer. Engine operating parameters such as an engine speed and an output torque are converted by a driveability data generating unit into driveability data such as an acceleration and vibration of the vehicle in accordance with the characteristic of the vehicle. These driveability data are converted by a sense-data generating unit into stimuli such as visual images, sounds and forces which can be directly perceived by the human senses.

Abstract: An internal combustion engine in which a three-way catalyst (12) for purification of the exhaust gas is arranged in the exhaust passage, wherein the relationship between the magnitude of the stress causing deterioration of the three-way catalyst (12), for example the catalytic bed temperature, and the rate of deterioration of the performance of the catalyst is found. A durability test is performed by raising the catalytic bed temperature higher than that of the vehicle under market driving. The length of the durability test at this time is determined from the relationship between the catalytic bed temperature and the rate of deterioration of the performance of the catalyst so as to give the same degree of deterioration of the performance of the catalyst as with market driving. The length of the durability test required for giving the same degree of deterioration of the performance of the catalyst is much shorter than the market driving time.

Abstract: A device for evaluating catalyst performance deterioration includes an air-fuel ratio sensor and a temperature sensor. The degree of catalyst performance deterioration per unit time is calculated based on the concentration of oxygen in the exhaust gas and the temperature of the catalyst. The deterioration of the catalyst is evaluated on the basis of the accumulated value of the degree of catalyst performance deterioration per unit time.

Abstract: An electrically heating catalytic apparatus that quickly heats catalyst to an activation temperature even when the engine is started at a low temperature below the catalyst activation temperature. The apparatus employs an electrically conductive catalyst carrier that is electrically heated. The carrier is provided with local hot spots to be energized. Since the heat is locally generated, the heat capacity of the catalyst carrier is small to shorten a temperature increasing time.

Abstract: An electrically heating catalytic apparatus that quickly heats catalyst to an activation temperature even when the engine is started at a low temperature below the catalyst activation temperature. The apparatus employs an electrically conductive catalyst carrier that is electrically heated. The carrier is provided with local hot spots to be energized. Since the heat is locally generated, the heat capacity of the catalyst carrier is small to shorten a temperature increasing time.

Abstract: An electrically heated catalytic converter having a scroll-like cylindrical laminated assembly in which belts of thin corrugated metal sheet and a thin plain metal sheet are laminated and wound around a center electrode, and the outermost layers are connected to an outer electrode. The corrugated metal sheet has an insulating coating made of a metal oxide, and the plain metal sheet has no insulating coatings. Conductive connections in which the corrugated metal sheet and the plain metal sheet are electrically connected to each other through the insulating coating of the corrugated metal sheet are made at predetermined positions in the layers of the laminated assembly and electric paths of desired shapes are formed by these conductive connections. The corrugated metal sheet and the plain metal sheet are connected in the areas around the respective conductive connections in such a manner that the metal sheets are isolated from each other.

Abstract: An electrically heated catalytic converter having a substrate for a catalyst which is formed as a scroll-like cylindrical laminated assembly, a rod like metal center electrode connected to the laminated assembly, and a casing accommodating the laminated assembly which also acts as an outer electrode. The center electrode extends from the laminated assembly along the central axis, bends towards the wall of the casing and penetrates the casing. The center electrode is fixed to the casing via an insulating material at the point where it penetrates the casing. Four buffer members are interposed between the laminated assembly and the casing, each of buffer members being made of a metal plate, one end of the respective buffer members being fixed to the casing at the portion near the penetration point of the center electrode, the other end of the respective buffer members being fixed to the outside of the laminated assembly.

Abstract: A knocking control device having a knocking detecting circuit for detecting, as an electrical signal, an amount of variation corresponding to an internal pressure variation within a cylinder of an engine due to an engine knocking; an averaging circuit for converting the electrical signal from the knocking detecting circuit to a signal corresponding to a knocking energy; a crank angle detecting circuit for detecting a rotation phase of the engine; a comparison circuit for comparing the output signal corresponding to the knocking energy of the averaging circuit with a reference value defining a knocking allowable level to obtain a control signal for maintaining an engine knocking strength in a predetermined range; and an ignition control circuit connected to an ignition circuit, for controlling the ignition timing of the ignition circuit by the control signal from the comparison circuit.

Abstract: A knocking detection method for internal combustion engines in which vibrations of the engine are detected by a vibration sensor and a peak value of the vibrations during a predetermined interval near the top dead center in each revolution of the engine is sampled. The peak value for each revolution is stored for a predetermined number of revolutions of the engine and an average value of the peak values is obtained. Then the ratio of each peak value to the average value is calculated, and the number of ratios whose magnitude exceeds a predetermined magnitude is expressed in terms of a rate or a percentage with respect to the total number of ratios, i.e., the predetermined number of revolutions of the engine. The presence or absence of the knocking is determined whether or not the rate or percentage is above a reference rate or percentage.

Abstract: A float chamber means for a carburetor having a heating element provided in its float chamber for selectively heating liquid fuel contained in the float chamber so that highly volatile components included in the fuel are vaporized in the float chamber and released from the liquid fuel before it enters into fuel passages provided in the carburetor thereby avoiding percolation due to abnormal vaporization of fuel in those fuel passages.

Abstract: A fuel supply system for engines having a carburetor which has a float chamber and a vapor bleed passage connected to the float chamber, wherein a part of a fuel supply passage means for supplying fuel from a fuel tank to the carburetor traverses through the float chamber so that the fuel flowing through the fuel supply passage means absorbs heat from the fuel contained in the float chamber. The fuel entering into the float chamber releases volatile light components as vapor towards the vapor bleed passage while the liquid fuel contained in the float chamber becomes a more stable liquid due to the release of volatile components and the cooling effected by heat exchange with the fuel flowing through the fuel supply passage means.

Abstract: Disclosed is a fuel feed device of an internal combustion engine. A heating device is disposed in the fuel supply conduit communicating the carburetor with the fuel tank for vaporizing the low boiling components in the fuel. The liquid fuel containing bubbles of the fuel vapor therein is introduced into a low boiling component separator. In this separator, the low boiling components in the fuel are removed and then the liquid fuel consisting of the high boiling components is fed into the carburetor.

Abstract: A fuel supply system for engines, including a fuel tank divided into first and second chambers, a fuel supply passage means including a fuel pump and supplying fuel from the fuel tank to a carburetor of the engine and a fuel return passage means for returning the excess fuel supplied to the carburetor to the second chamber of the fuel tank. An upper region of the second chamber is bled, while the first chamber is supplied with new fuel, the fuel supply passage means including a change-over valve which usually connects the fuel supply passage to the first chamber, while it connects the fuel supply passage to the second chamber when the fuel temperature has risen beyond a predetermined value.

Abstract: Disclosed is a fuel feed device of an internal combustion engine. The fuel supply conduit communicating the carburetor and the fuel tank is arranged in the carburetor for cooling the carburetor and for vaporizing the low boiling components in the fuel only when the temperature of the engine is higher than a predetermined level. The fuel flowing out from the fuel supply passage located in the carburetor is introduced into a low boiling component separator. In this separator, the low boiling components in the fuel are removed, and then the fuel consisting of the high boiling components is fed into the carburetor to prevent the occurrence of an abnormal fuel metering operation under a high-temperature condition.