Clutch actuator structure

1. A clutch actuator structure, comprising:

a clutch actuator which controls oil pressure for engaging and disengaging a hydraulic clutch mechanism which transmits a rotational driving force of an engine,

a crankcase cover which covers a side of a crankcase of an engine,

an oil sump which reserves oil, the oil sump being formed in an inner surface of the crankcase cover, the inner surface facing the crankcase,

wherein said clutch actuator is disposed in said oil sump, and

wherein said crankcase cover further comprises

a control oil passage formed within said crankcase cover and extending from said actuator to a pressurization chamber of said hydraulic clutch mechanism.

2. The clutch actuator structure according to claim 1 ,

wherein said hydraulic clutch mechanism comprises a plurality of clutches, and

wherein a plurality of said control oil passages are formed to extend from said clutch actuator to said hydraulic clutch mechanism substantially in parallel to each other.

3. The clutch actuator structure according to claim 2 , wherein said clutch actuator includes an oil discharge hole which opens to said oil sump.

4. The clutch actuator structure according to claim 3 , wherein the clutch actuator includes a valve part which comprises

a tubular member to which said plurality of oil passages are connected, and

a sliding member disposed in said tubular member so as to switch between communicating conditions of said plurality of oil passages,

wherein when said sliding member slides relative to said tubular member by an operation of the clutch actuator, return oil from said hydraulic clutch mechanism is discharged from said oil discharge hole of said clutch actuator.

5. The clutch actuator structure according to claim 4 , wherein said supply oil passage for supplying oil from said oil pump to said valve part is branched and extended to form said lubricating oil passage.

6. The clutch actuator structure according to claim 1 , wherein an oil return hole is disposed above said clutch actuator.

7. The clutch actuator structure according to claim 1 ,

wherein said clutch actuator is located on a front lower side of said clutch mechanism in side view of the engine.

8. The clutch actuator structure according to claim 7 ,

wherein said clutch mechanism is disposed on a rear upper side of a crankshaft in side view of the engine, and

wherein said clutch actuator is disposed on a lower side of the crankshaft in side view of the engine.

9. The clutch actuator structure according to claim 8 ,

wherein a main shaft coaxial with said clutch mechanism is disposed on the rear upper side of the crankshaft,

wherein a slant surface facing toward a front upper side is formed on an upper wall of the crankcase at a position between a position directly above the crankshaft and a position directly above the main shaft, and

wherein an engine hanger is projectingly formed on the slant surface of the upper wall of the crankcase.

10. The clutch actuator structure according to claim 1 ,

wherein a recessed space is formed in the crankcase cover on a side of the crankcase cover which is opposite to the side which covers the crankcase of the engine,

wherein the recessed space is disposed behind the clutch actuator and below a portion of the crankcase cover covering the pressurization chamber of said clutch mechanism, and

wherein the recessed space is adapted as a foot rest space for a rider of a vehicle in which the clutch actuator structure is disposed.