| 摘要 |
PURPOSE:To suppress generation of judder phenomena likely under half dry condition by locating the coupling part where the moment of momentum at the fore part of a wire blade balances with that at the back part of the blade. CONSTITUTION:If the coupling point is located in the middle of a wiper blade 20, the swing velocity at the fore and back parts of this wire blade 20 differ much from each other as it is proportionate to the distance from the shaft for swinging 15, that leads to likelihood of generation of judder phenomena. Thus, the wiper blade 20 is divided asymmetrically, and the coupling part 17 is set on this dividing point where the moments of momentum at those two ends of the blade 20 balance with each other, that will assure application of well-balanced swing force to the blade 20. Accordingly, the wiper blade 20 moves with the same angular velocity W, and judder phenomenon does not tend to arise. If the lengths of the fore and back parts of blade 20 are represented by l1 and l2, respectively, however, the extent of the value l1/l2 is restricted by the range to be wiped in front glass 13, swing mechanism of the arm 16, etc., a practical value for l1/l2 will be 0.4-0.7. |
