| 摘要 |
The invention prevents the occurrence of depressions at a screw thread on a terminal side and to prevent the occurrence of depressions at a groove on the side of a cylindrical section. FIG. 13(b) is a view taken in the direction of arrows b-b in FIG. 13(a) with a white arrow showing the direction of vibrations due to external force. This shows that the direction of the vibrations is parallel or substantially parallel with the straight section 31. If the main vibrations of the engine are in a direction from the front to the rear of the vehicle, and if the straight section 31 is made to extend along this direction, then these inevitably become parallel or substantially parallel. As a result, the straight section 31(b) moves from left to right and there is therefore no problems with wear due to frictional contact with the screw threads 17 and 17. <IMAGE> |
