| 摘要 |
PURPOSE:To perform hammering plural consecutive times in a manner to always hold a bucket at a specified contact, by a method wherein a distance between the contact of the bucket and a grounding point is made constant under a state in that the bucket is brought into contact with an object to be broken. CONSTITUTION:A rod 7a of an arm cylinder 7 is contracted by a proper amount as a rod 9a of a bucket cylinder 9 is expanded, and this causes movement of an arm 6 of a bucket 8 without changing a distance. In which case, the bucket 8 performs circular movement around a point D, a pin 14 is moved, and the pin 14 is positioned on a straight line through which a pin 13 and the point D are interconnected. Dropping energy is produced as a collision force on the point D of an object C to be broken by an excavating blade 8a of the bucket 8 to strike on the point D. This enables to perform hammering plural consecutive times in a manner to hold a contact to a constant value, and prevents a high power beyond estimation from being exerted thereon, resulting in the possibility to improve durability. |
