1. Field of the Invention
The present invention relates to an arrangement of an oil filter for engine oil and an oil passage in a vehicle engine. More particularly to an arrangement for providing an ease of maintenance.
2. Description of Background Art
Conventionally, in a vehicle engine provided with exhaust pipes which are curved downwardly from a front wall of a cylinder body, pass in front of and below a crankcase, and extend rearwardly of an engine body, a cartridge type oil filter is available that is attached between a vertically extending portion of one of the exhaust pipes and a front wall of the crankcase so as to be detachable in a vehicle body width direction from a side end side of the engine body. See, for example, Publication of Japanese Patent No. 2705777. Thus, obstructions with respect to the attachment/detachment direction of the oil filter are removed to enhance an ease of maintenance. In addition, front and back portions of the oil filter can be protected by the exhaust pipe and the crankcase.
The attachment/detachment of the cartridge type oil filter usually requires a rotation of the oil filter. Accordingly, it is necessary to rotate the oil filter itself by utilizing a tool or an individual's hand.
However, in the conventional vehicle engine described above, the exhaust pipes and the crankcase are arranged in front of and to the rear of the oil filter. Accordingly, it is difficult to position the tool or the individual's hand onto the oil filter. In addition, it is difficult to perform the rotation of the oil filter. Moreover, widening a gap between the exhaust pipes and the crankcase for the purpose of ensuring a working space increases an outer dimension of the engine and lowers a degree of freedom in vehicle body layout. Therefore, it is not preferable.