| 摘要 |
PURPOSE:To reduce the number of parts used and suppress the man-hours in assembly process by dividing a crank case construction into two, up and below, with the crank axis as the boundary of dividing, and by forming the upper half in the center of fan housing and cylinder and the lower half in the lower part of the fan housing solidly each as in a single piece. CONSTITUTION:A crank case 1 is divided into two up and below with the crank axis as the boundary of dividing. A fan housing 6 is divided into three; an upper part 7, a central part 8 and lower part 9 the latter two being formed as a box. The upper half 2 of the crank case 1 is made from aluminum by die-casting as in a single piece with the cylinder 5 and the said central part 8. The lower half 3 is made also as in a single piece with the said lower part 9. The upper part 7 is made from resin as in a single piece with the said lower part 9. The upper part 7 is made from resin as in a single piece with a cooling wind cover 10 and a muffler cover 11. Thereafter the upper half 2 and the central part 8 are coupled with the lower half 3 and the lower half 9 using bolts etc. This can well reduce the number of parts used as well as suppress the man-hours required in assembly process. |
