| 摘要 |
<p>PURPOSE:To accurately set the normal angular position of mounting of cam suction and exhaust valve driving cam shafts as to a crankshaft at the time of fitting of a timing belt or chain and apply niform initial tension to the timing belt or the like. CONSTITUTION:In mounting work, a crankshaft 2 is first fixed in the top dead center position corresponding to the beginning of opening of a suction valve, on the basis of a top dead center sign on the crankshaft. The circular hole 25 of a cam shaft 12 for the suction valve and that 24 of a bearing 17 are aligned to each other. A lockup pin 26 is inserted into the circular holes 24, 25. A sprocket 5 is fitted on the end of the cam shaft 12. Circular holes 22a, 23a are aligned to each other. Another sprocket 6 is also fitted on a cam shaft for an exhaust valve in the same way. A timing belt 11 is fitted on sprockets 3-6. One end of a tension spring 28 is anchrored to the anchoring part 27 of an arm 8. Tension is applied to the timing belt 11 by an idler 10. After the arm 8 is fixed on the engine body 1, the spring 28 is removed and the pin 26 is pulled out.</p> |
