| 摘要 |
A hammer drill (100) comprises a main housing (101), a hand grip (109) connected to the main housing (101) via a compression coil spring (171). In the hammer drill (100), a hammer bit (119) is driven by a motion converting mechanism (120), a hammering mechanism (140) and a rotation transmitting mechanism (150), and thereby performs a hammer-drill operation. During the hammer-drill operation, the hand grip (109) is moved against the main housing (101) in a state that biasing force of the compression coil spring (171) is applied. Further, the hammer drill (100) comprises a counterweight (190). The gravity center of the counterweight (190) is set to be lower than the upper edge of a cylinder (129) which is one component of the motion converting mechanism (120). |
