Abstract: A torque limiter that enables setting a larger torque capacity although being compact and easy to incorporate into a power transmission mechanism, is provided. A torque limiter is incorporated into a power transmission mechanism for transmitting power from a starter motor to a crankshaft of an internal combustion engine. The torque limiter includes a driven gear for receiving power from the starter motor and a transmission gear for transmitting power. The driven gear and the transmission gear are coaxially disposed in a relatively rotatable manner. The driven gear and the transmission gear are configured to transmit power therebetween via a friction member. The friction member has a circular disc shape with an outer diameter that is larger than an outer diameter of the driven gear.

Abstract: A crank case structure that can reduce a front-rear dimension of the crank case to reduce the size of a power unit. A crank case structure adapted to a crank case (9) that houses a crankshaft (C) of a power unit (P), including a crank case cover (20) attached to a side surface of the crank case (9), a push rod (31) that is disposed parallel to the crankshaft (C) and reciprocates to disengage a clutch (CL), and a clutch drive unit (30) that reciprocates the push rod (31). A through hole (32), through which the push rod (31) passes, is formed within an area of a sealing surface (29), the sealing surface (29) is formed in the crank case (9) to attach to the crank case cover (20), and the clutch drive unit (30) is attached to the crank case cover (20).

Abstract: A torque limiter that enables setting a larger torque capacity although being compact and easy to incorporate into a power transmission mechanism, is provided. A torque limiter is incorporated into a power transmission mechanism for transmitting power from a starter motor to a crankshaft of an internal combustion engine. The torque limiter includes a driven gear for receiving power from the starter motor and a transmission gear for transmitting power. The driven gear and the transmission gear are coaxially disposed in a relatively rotatable manner. The driven gear and the transmission gear are configured to transmit power therebetween via a friction member. The friction member has a circular disc shape with an outer diameter that is larger than an outer diameter of the driven gear.

Abstract: An in-case oil passage extending in an axial direction above a plurality of gears is formed inside an outer peripheral wall portion of the accommodating case. The in-case oil passage includes an in-case oil passage opening portion which opens from the cover wall portion to the one end side in the axial direction. The cover wall portion is provided with an oil guide member at a position where at least a part of the cover wall portion overlaps the in-case oil passage opening portion when viewed from the one end side in the axial direction, the oil guide member guiding oil discharged from the in-case oil passage opening portion to the oil collecting portion of the oil collecting pocket.

Abstract: An in-case oil passage extending in an axial direction above a plurality of gears is formed inside an outer peripheral wall portion of the accommodating case. The in-case oil passage includes an in-case oil passage opening portion which opens from the cover wall portion to the one end side in the axial direction. The cover wall portion is provided with an oil guide member at a position where at least a part of the cover wall portion overlaps the in-case oil passage opening portion when viewed from the one end side in the axial direction, the oil guide member guiding oil discharged from the in-case oil passage opening portion to the oil collecting portion of the oil collecting pocket.

Abstract: Provided is a crank angle detection device that includes an ACG rotor supported by an end of a crank shaft and configured to rotate integrally with the crank shaft, a metal-plate-made pulsar ring including a ring-shaped plate portion and a detected portion that includes a plurality of convex portions formed at an outer circumference of the ring-shaped plate portion, and being configured to rotate integrally with the ACG rotor with the ring-shaped plate portion fixed to the ACG rotor, and a magnetic sensor arranged at an outer circumference of the pulsar ring and configured to detect the detected portion. Such a crank angle detection device is capable of detecting a crank angle with high accuracy.

Abstract: A transmission includes an oil pipe disposed above a first gear group and a second gear group, the oil pipe having small holes. The oil pipe is formed integrally with a first restricting portion and a second restricting portion, the first restricting portion abutting against an inner surface of a first unit inside a case to thereby restrict an axial position of the oil pipe on an outside in one direction, and the second restricting portion abutting against an inner surface of a second unit to thereby restrict an axial position of the oil pipe on an outside in an other direction and rotation thereof.

Abstract: In a valve train of an internal combustion engine, an input sprocket mounting portion is provided on one end of an exhaust camshaft, and a valve operating cam portion is formed on the other end of the camshaft. A decompression shaft of a decompression device is inserted in a decompression shaft hole, which is formed from the input sprocket mounting portion toward the valve operating cam portion. The decompression shaft hole is formed at a position offset from an axis of the camshaft. A camshaft inner oil passage is formed in the camshaft to extend from one end toward the other end of the camshaft in parallel arrangement to the decompression shaft hole to supply lubricant from the bearing journal portion to the bearing journal portion. The above arrangement makes it possible to supply a sufficient amount of lubricant oil to slide portions of the valve train of a saddle riding vehicle.

Abstract: To provide a saddle type vehicle with a water cooled engine allowing simplification of the mounting structure for a thermostat and a check valve. A saddle type vehicle having a water cooled engine, includes: a thermostat provided in a cooling water path of the water cooled engine; and a check valve provided in a secondary air path supplying secondary air to an exhaust path of the water cooled engine, wherein a case of the thermostat and a case of the check valve are formed integrally. The case of the thermostat is formed in a cylindrical configuration, and the case of the check valve is integrally connected to the cylindrical side wall thereof.

Abstract: To provide an engine side cover structure of a saddle type vehicle that can also cover the back side of a crankcase. An engine side cover structure of a saddle type vehicle includes a vehicle body frame arranged between a front wheel and a rear wheel; an engine including a crankcase, and a cylinder extending upward from the crankcase, the engine being supported by the vehicle body frame; and a side cover covering a side of the crankcase; where the side cover includes a cover main body that covers the side of the crankcase, and an extended portion that extends backward from the cover main body; and the cover main body is fixed to the crankcase, and the extended portion is fixed to the vehicle body frame.

Abstract: Provided is a crank angle detection device that includes an ACG rotor supported by an end of a crank shaft and configured to rotate integrally with the crank shaft, a metal-plate-made pulsar ring including a ring-shaped plate portion and a detected portion that includes a plurality of convex portions formed at an outer circumference of the ring-shaped plate portion, and being configured to rotate integrally with the ACG rotor with the ring-shaped plate portion fixed to the ACG rotor, and a magnetic sensor arranged at an outer circumference of the pulsar ring and configured to detect the detected portion. Such a crank angle detection device is capable of detecting a crank angle with high accuracy.

Abstract: In a single cylinder internal combustion engine in which a plug hole is provided striding between a cylinder head and a head cover, and an intake side camshaft and an exhaust side camshaft are disposed at positions sandwiching the plug hole therebetween, a long hole portion formed long in a direction orthogonal to axes of the camshafts is formed as a part of the plug hole. A part of a plurality of cam holder attaching bolts used for fastening the cam holder to the cylinder head are disposed within the long hole portion. A breather chamber disposed around the long hole portion is formed between the head cover and a breather plate attached thereto.

Abstract: Provided is a saddle-ride type vehicle that can improve the cooling ability when a radiator fan is provided only on one radiator of right and left radiators. A saddle-ride type vehicle has a water-cooled engine, right and left radiators supported by a body frame, and a cooling water passage that connects the right and left radiators and the water-cooled engine. A radiator fan is provided only on one radiator of the right and left radiators. One cooling water passage that connects the one radiator and the water-cooled engine has a larger diameter than the other cooling water passage that connects the other radiator and the water-cooled engine. The one radiator is larger than the other radiator.

Abstract: In a valve train of an internal combustion engine, an input sprocket mounting portion is provided on one end of an exhaust camshaft, and a valve operating cam portion is formed on the other end of the camshaft. A decompression shaft of a decompression device is inserted in a decompression shaft hole, which is formed from the input sprocket mounting portion toward the valve operating cam portion. The decompression shaft hole is formed at a position offset from an axis of the camshaft. A camshaft inner oil passage is formed in the camshaft to extend from one end toward the other end of the camshaft in parallel arrangement to the decompression shaft hole to supply lubricant from the bearing journal portion to the bearing journal portion. The above arrangement makes it possible to supply a sufficient amount of lubricant oil to slide portions of the valve train of a saddle riding vehicle.

Abstract: An internal combustion engine for increasing the freedom of the layout of a rocker arm wherein the rocker arm is lighter. The internal combustion engine includes a camshaft having a first exhaust cam and a second exhaust cam, a first exhaust valve, and a second exhaust valve. The internal combustion engine further includes a first rocker arm for actuating the first exhaust valve to open and close, a second rocker arm for actuating the second exhaust valve to open and close, and a decompression mechanism for lifting the first rocker arm in a valve opening direction at the timing of a compression stroke initiated by the internal combustion engine. The first rocker arm and the second rocker arm are provided with an angular movement transmitter for transmitting a turning force produced by a decompression operator in the valve opening direction from the first rocker arm to the second rocker arm.

Abstract: Provided is a saddle-ride type vehicle that can improve the cooling ability when a radiator fan is provided only on one radiator of right and left radiators. A saddle-ride type vehicle has a water-cooled engine, right and left radiators supported by a body frame, and a cooling water passage that connects the right and left radiators and the water-cooled engine. A radiator fan is provided only on one radiator of the right and left radiators. One cooling water passage that connects the one radiator and the water-cooled engine has a larger diameter than the other cooling water passage that connects the other radiator and the water-cooled engine. The one radiator is larger than the other radiator.

Abstract: A transmission includes an oil pipe disposed above a first gear group and a second gear group, the oil pipe having small holes. The oil pipe is formed integrally with a first restricting portion and a second restricting portion, the first restricting portion abutting against an inner surface of a first unit inside a case to thereby restrict an axial position of the oil pipe on an outside in one direction, and the second restricting portion abutting against an inner surface of a second unit to thereby restrict an axial position of the oil pipe on an outside in an other direction and rotation thereof.

Abstract: In a single cylinder internal combustion engine in which a plug hole is provided striding between a cylinder head and a head cover, and an intake side camshaft and an exhaust side camshaft are disposed at positions sandwiching the plug hole therebetween, a long hole portion formed long in a direction orthogonal to axes of the camshafts is formed as a part of the plug hole. A part of a plurality of cam holder attaching bolts used for fastening the cam holder to the cylinder head are disposed within the long hole portion. A breather chamber disposed around the long hole portion is formed between the head cover and a breather plate attached thereto.

Abstract: To provide an engine side cover structure of a saddle type vehicle that can also cover the back side of a crankcase. An engine side cover structure of a saddle type vehicle includes a vehicle body frame arranged between a front wheel and a rear wheel; an engine including a crankcase, and a cylinder extending upward from the crankcase, the engine being supported by the vehicle body frame; and a side cover covering a side of the crankcase; where the side cover includes a cover main body that covers the side of the crankcase, and an extended portion that extends backward from the cover main body; and the cover main body is fixed to the crankcase, and the extended portion is fixed to the vehicle body frame.

Abstract: To provide a saddle type vehicle with a water cooled engine allowing simplification of the mounting structure for a thermostat and a check valve. A saddle type vehicle having a water cooled engine, includes: a thermostat provided in a cooling water path of the water cooled engine; and a check valve provided in a secondary air path supplying secondary air to an exhaust path of the water cooled engine, wherein a case of the thermostat and a case of the check valve are formed integrally. The case of the thermostat is formed in a cylindrical configuration, and the case of the check valve is integrally connected to the cylindrical side wall thereof.