Abstract: A cylinder head includes an exhaust port through which exhaust gas discharged out of a combustion chamber of an internal combustion engine passes. The cylinder head includes a first fin and a second fin projecting from an inner wall of the exhaust port and extending in a flow direction of the exhaust gas. The cylinder head includes a first projection projecting from the inner wall of the exhaust port and extending in a direction intersecting the first fin. The cylinder head also includes a second projection projecting from the inner wall of the exhaust port and extending in a direction intersecting the second fin.

Abstract: A cylinder head includes an exhaust port through which exhaust gas discharged out of a combustion chamber of an internal combustion engine passes. The cylinder head includes a first fin and a second fin projecting from an inner wall of the exhaust port and extending in a flow direction of the exhaust gas. The cylinder head includes a first projection projecting from the inner wall of the exhaust port and extending in a direction intersecting the first fin. The cylinder head also includes a second projection projecting from the inner wall of the exhaust port and extending in a direction intersecting the second fin.

Abstract: A secondary air supplying system of an internal combustion engine includes secondary air valve chambers to control the supply of secondary air. The secondary air valve chambers are formed in a cylinder-head cover that covers a cylinder head from above. In such a secondary air supplying system, a cam shaft and a rocker-arm shaft are offset from a cylinder axis L and are disposed at respective sides of the cylinder axis L from each other. In addition, the secondary air valve chambers are formed at the rocker-arm-shaft side of the cylinder axis L. With this configuration, it is possible for the secondary air valve chambers formed in the cylinder-head cover to be disposed as close as possible to a cylinder head, and the internal combustion engine can be made more compact in size.

Abstract: In a multiple disc clutch apparatus 10, a cam member 41 which is disposed on a side of a clutch inner member 16 is formed into an annular shape. The cam member 41 extends in a radial direction so that an outer circumferential surface of the cam member 41 is brought into abutment with a cylindrical face 19d on an inner circumferential surface of a clutch center member 19.

Abstract: An intake port structure for an internal combustion engine according to the invention includes a valve shaft provided in an intake port; and an airflow control valve that is supported by the valve shaft at one end of the airflow control valve or at a position near the one end. A gap is formed between the airflow control valve and a wall surface of the intake port, which is positioned on one side of the valve shaft. Because intake airflow passes through the gap that is formed, the generation of a deposit is suppressed, and the locking of the airflow control valve is avoided.

Abstract: An electric motor is cooled by an air flow without restricting the degree of freedom in the arrangement of an oil cooler and an oil filter by utilizing a front face of a front portion of an engine body to arrange the electric motor. The engine includes an oil cooler, an oil filter, and an starter motor for driving a crankshaft to rotate. The oil cooler and the starter motor are disposed on a front face, which is directed in an advancing direction of the vehicle, of a front portion of a lower block which forms an engine body. The oil filter is attached to an attachment seat provided on a side face of the front portion which is directed in the sideward direction. A communication oil path for communicating the oil cooler and the oil filter with each other is provided in the inside of the front portion.

Abstract: In a multiple disc clutch apparatus 10, a cam member 41 which is disposed on a side of a clutch inner member 16 is formed into an annular shape. The cam member 41 extends in a radial direction so that an outer circumferential surface of the cam member 41 is brought into abutment with a cylindrical face 19d on an inner circumferential surface of a clutch center member 19.

Abstract: An intake port structure for an internal combustion engine according to the invention includes a valve shaft provided in an intake port; and an airflow control valve that is supported by the valve shaft at one end of the airflow control valve or at a position near the one end. A gap is formed between the airflow control valve and a wall surface of the intake port, which is positioned on one side of the valve shaft. Because intake airflow passes through the gap that is formed, the generation of a deposit is suppressed, and the locking of the airflow control valve is avoided.

Abstract: A secondary air supplying system of an internal combustion engine includes secondary air valve chambers to control the supply of secondary air. The secondary air valve chambers are formed in a cylinder-head cover that covers a cylinder head from above. In such a secondary air supplying system, a cam shaft and a rocker-arm shaft are offset fi-om a cylinder axis L and are disposed at respective sides of the cylinder axis L from each other In addition, the secondary air valve chambers are formed at the rocker-arm-shaft side of the cylinder axis L. With this configuration, it is possible for the secondary air valve chambers formed in the cylinder-head cover to be disposed as close as possible to a cylinder head, and the internal combustion engine can be made more compact in size.

Abstract: An electric motor is cooled by an air flow without restricting the degree of freedom in the arrangement of an oil cooler and an oil filter by utilizing a front face of a front portion of an engine body to arrange the electric motor. The engine includes an oil cooler, an oil filter, and an starter motor for driving a crankshaft to rotate. The oil cooler and the starter motor are disposed on a front face, which is directed in an advancing direction of the vehicle, of a front portion of a lower block which forms an engine body. The oil filter is attached to an attachment seat provided on a side face of the front portion which is directed in the sideward direction. A communication oil path for communicating the oil cooler and the oil filter with each other is provided in the inside of the front portion.

Abstract: An intake device includes an intake pipe, a valve having a downstream side including a cutoff portion and an upstream side rotatably attached to an inner wall of the intake pipe, and a partition plate provided in the intake pipe so as to divide an intake passage in the intake pipe into an upper intake passage and a lower intake passage. The valve has an open state in which the upper and lower intake passages are open, a closed state in which the upper and lower intake passages are closed; and an intermediate state in which the lower intake passage is closed.

Abstract: An intake device includes an intake pipe, a valve having a downstream side including a cutoff portion and an upstream side rotatably attached to an inner wall of the intake pipe, and a partition plate provided in the intake pipe so as to divide an intake passage in the intake pipe into an upper intake passage and a lower intake passage. The valve has an open state in which the upper and lower intake passages are open, a closed state in which the upper and lower intake passages are closed; and an intermediate state in which the lower intake passage is closed.

Abstract: A dry multi-disc clutch includes a plurality of friction discs interposed between a drive-side clutch outer and a driven-side clutch center and power is transmitted from the clutch outer to the clutch center by pushing these friction discs using a pressure plate. Fins which enhance a flow of air are formed on the clutch outer and the pressure plate and, at the same time, passages which allow the communication of air are formed in the clutch outer and the pressure plate. With such a clutch structure it is possible to efficiently radiate the friction heat, which is generated when the clutch is connected, and the heat transmitted from the engine and, at the same time, it is possible to discharge the wear powder that is generated when the clutch is connected. As a result, it is possible to stabilize the clutch performance.

Abstract: A dry multi-disc clutch includes a plurality of friction discs interposed between a drive-side clutch outer and a driven-side clutch center and power is transmitted from the clutch outer to the clutch center by pushing these friction discs using a pressure plate. Fins which enhance a flow of air are formed on the clutch outer and the pressure plate and, at the same time, passages which allow the communication of air are formed in the clutch outer and the pressure plate. With such a clutch structure it is possible to efficiently radiate the friction heat, which is generated when the clutch is connected, and the heat transmitted from the engine and, at the same time, it is possible to discharge the wear powder that is generated when the clutch is connected. As a result, it is possible to stabilize the clutch performance.

Abstract: A lubricating oil feed passage in a crank shaft, having lubricating oil passages formed in the crank shaft and having an inlet end and an outlet end which is open to a connection surface of a crank pin for connection with a connecting rod, a bolt secured to an end portion of the crank shaft so as to project in an axial direction of the crank shaft from an end face of the shaft end portion, and a lubricating oil introducing passage formed axially through the bolt and connected to the inlet end.

Abstract: A nutless type connecting rod of high mass production efficiency is provided. A large end section of a connecting rod is divided into a body side and a cap section, which are subjected to surface hardening treatment. Then the surface-hardened layer formed on a division face of the body side is removed. Thereafter, a female threaded hole is formed through the division face into the thickness of the body.