Abstract: An exhaust purifying apparatus for an in-cylinder injection type internal combustion engine causes exhaust gas temperature to rise reliably, thereby desorbing reliably a sulfur component (SOx) adhered to an NOx catalyst and enhancing the durability of the NOx catalyst. For this reason, the exhaust purifying apparatus for an in-cylinder injection type internal combustion engine comprises an NOx catalyst (9A) for adhering NOx to itself in an excess oxygen concentration condition and desorbing NOx in an oxygen concentration reduction condition, and sulfur component desorption means (107) for desorbing a sulfur component from the NOx catalyst (9A). The sulfur component desorption means (107) injects additional fuel during an expansion stroke in addition to main injection and burns the additional fuel again so that exhaust gas temperature is raised to a predetermined temperature or beyond, whereby the sulfur component is desorbed.

Abstract: An exhaust gas heating system for an in-cylinder injection internal combustion engine is disclosed. The system includes a fuel injection device for injecting fuel directly into a combustion chamber of the engine, a spark plug for subjecting fuel, which has been injected as primary fuel from the injection device, to spark ignition such that the primary fuel undergoes primary combustion, an exhaust gas purification device arranged in an exhaust passage of the engine, a purification device temperature computing unit for determining a temperature of the purification device by detecting or estimating the temperature of the purification device, and an additional fuel injection control unit for controlling the injection device when the purification device is found to require activation from the temperature determined by the computing unit, such that an injection of fuel as additional fuel is performed during a flame lasting duration that a flame of the primary combustion remains.

Abstract: An internal combustion engine according to this invention is provided with intake ports each of which is formed to guide a flow of inducted air in a particular direction. Each intake port includes, in the vicinity of its corresponding intake opening to a combustion chamber, a bent port portion bent at a greater curvature than a port portion on a side upstream of the bent port portion. The bent port portion has a greater inner diameter than the inner diameter of the corresponding intake opening, whereby air can be inducted in a sufficient amount without deterioration to the directing function for air to be inducted into the combustion chamber.

Abstract: A stratified burning internal combustion engine according to this invention is equipped with an intake port and a fuel feed device so that stratified tumble flows of different fuel concentrations can be formed in a combustion chamber. An ignition device is provided in the combustion chamber to ignite at least one of the tumble flows, said at least one tumble flow being rich in fuel. To promote the stratified tumble flows, a top wall of a piston has an inclined wall. This makes it possible to strengthen the tumble flows, whereby the stratification of an air-fuel mixture in the combustion chamber can be improved further to permit lean burn at a larger air/fuel ratio.

Abstract: An internal combustion engine according to this invention is provided with intake ports and an injector. The intake ports are designed to form stratified tumble flows of different fuel concentrations in a combustion chamber. A spark plug is arranged in the combustion chamber to ignite one of the tumble flows, which one tumble flow is rich in fuel. Each intake port is provided with a longitudinal partition which divides an interior of the intake port into two passages. These longitudinal partitions are formed in such a way that, of the air-fuel tumble flows formed around the spark plug, the tumble flow closest to the spark plug is formed of a richer air-fuel mixture. Each longitudinal partition is arranged only on a side upstream of a valve stem of an intake valve in the corresponding intake port, so that a sufficient amount of intake air can be obtained while extremely minimizing a reduction in the actual cross-sectional flow area.

Abstract: A metal gasket for sealing a three-component joint structure in which first and second joint members are disposed in confronting relation so as to align their respective holes with each other and in which an outer peripheral portion of a third joint member is fitted in a recess in the confronting surface of the first joint member. The metal gasket has an opening and is adapted to be placed between the first and second joint members so as to align the opening with the holes of the two joint members. The metal gasket also has, at a position near the opening, a stepped portion defined by first and second bends engageable with the first and second joint members, respectively, as the metal gasket is placed between the two joint members. As the first and second joint members are tightened so as to clamp the third member and the metal gasket, the stepped portion is deformed so as to bring the second bend to a position confronting the third joint member.

Abstract: In a cooling apparatus for an engine, a water jacket is divided into two parts, namely a forcible circulation part located chiefly round a cylinder head, and a natural convection part located chiefly round a liner of a cylinder block. The natural convection part is filled at its upper space with a cooling water and at its lower space with a cooling medium different from the cooling water. The cooling medium has a boiling point around a temperature zone to cool the liner, and also has a specific gravity larger than that of the cooling water and immiscible with the cooling water.

Abstract: An engine cooling apparatus separately cools a cylinder head and a cylinder block which are positioned around upper and lower portions of an engine combustion chamber. For increased engine output power, the engine cooling system cools the cylinder head to a relatively low temperature and the cylinder block to a relatively high temperature. The cylinder block includes cylinder liners disposed in an oil jacket which is supplied with oil from an oil circulating system via a pressure reducing valve. Oil in the oil jacket returns through a return path into an oil reservoir in the engine, and air bubbles in the oil jacket are returned to the oil reservoir via an air bubble return passage which develops a pressure difference between its opposite open ends.