Patent ID: 7048072

Claim:
An excavator comprising: a lower traveling body; and a dozer unit attached to the lower traveling body, the dozer unit including a dozer arm and a blade attached to a front end of the dozer arm in a manner such that the blade is disposed at a predetermined rake angle with respect to the ground, wherein the blade has a blade surface used for performing an earth removal operation by moving the lower traveling body while the blade is set in contact with the ground, the blade surface satisfying the following conditions: A) upward pushing force components Fu that push dirt upward along the blade surface are generated; B) an upper part of the blade surface is provided with a release surface portion in which a forward-upward release force that rolls the dirt pushed upward by the upward pushing force components Fu towards the front of the blade is generated; C) when downward pressing force components Fd are generated in response to the generation of the release force in the release surface portion, a total downward pressing force ΣFd and a total upward pushing force ΣFu form the relationship ΣFu>ΣFd; and D) if each upward pushing force component Fu is indicated by a positive value and if each downward pressing force component Fd and a reduced amount of each upward pushing force component Fu caused when the dirt hits the release surface portion are indicated by negative values, a value of force applied to the dirt at an endmost section of the release surface portion is positive.