| 主权项 |
1. A drill bit exchange device for a shield tunneling machine in which a drill bit disposed at a front of a cutter head is exchanged during drilling from a working space formed in the cutter head,
the drill bit exchange device comprising: a housing with a tunneling aperture part attached to the front of the cutter head so as to expose the drill bit; a valve body disposed in a valve-housing chamber that is formed in the housing so as to communicate with the tunneling aperture part, the valve body being pivotable about a pivot axis inclined at a predetermined angle with respect to an axis perpendicular to the front of the cutter head; a bit-housing hole that is formed in the valve body so as to communicate with the tunneling aperture part, the drill bit being detachably housed in the bit-housing hole; and an exchange seal part disposed at a front of the valve-housing chamber, the exchange seal part being separated from the tunneling aperture part at a pivoting position of the tunneling aperture part with respect to the pivot axis, wherein the valve body is substantially cylindrical and includes a seal body that is formed along a front outer edge of the valve body so as to seal the tunneling aperture part, an opening for the bit-housing hole formed on a part of the seal body, and a drilling recess that is formed by removing the seal body around the opening for the bit housing hole and accommodates a drilling end of the drill bit, the drill bit exchange device further comprises an exchange seal member that seals a clearance between the housing and the valve body around the exchange seal part, and the valve body is pivoted about the pivot axis so as to move the drill bit in the drilling recess to the exchange seal part when the drill bit is exchanged, allowing the drill bit to be removed from the bit-housing hole and exchanged. |
