| 摘要 |
<p>A dust collection nozzle (12) is provided through the upper blade guard 7 of a circular saw (1). The dust collection nozzle (12) includes a flared, horn-shaped dust capturing section (13) having a rectangular opening at the front end thereof, and a cylindrical dust outlet tube (14) connected to the rear end of the dust capturing section (13). Throughout cutting operations, the opening (16) remains directed toward the lower portion of the saw blade (8) so as to collect dust and other debris generated from a saw blade (8) rotatable attached to the upper blade guard. The dust collection nozzle (12) also includes a pair of dust guide plates (17, 18) formed on and extended from the opening (16). The dust guide plates (17, 18) extend in parallel to each other so as to interpose the saw blade (8) therebetween. Furthermore, provided to the right of the dust guide plate (18) is a flow straightening plate (19) extending in parallel to plates (17) and (18) from the upper to lower edges of the opening (16). Also, the flow straightening plate (19) extends into the dust capturing section (13), thus partitioning the dust collection passage into two sections, and terminates at the boundary between the capturing section (13) and the dust outlet tube (14). The plates (17) and (19), and the dust capturing section (13) jointly define an air flow cavity (20). The flow straightening plate (19) divides the opening closer to the right side edge of the opening (16) than the left side edge in order to widen the air flow cavity (20).</p> |
