Method for controlling the direction of a shield tunneling machine and an apparatus therefor

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a directional control device and a method of controlling a direction of a shield tunneling machine are explained.
Referring to FIG.
1, shield tunneling machine A comprises a cutter head 1 arranged at the head in the advancing direction thereof (the left side in FIG.
1) and tail shield 2 (the right side in FIG.
1) following cutter head 1.
Cutter head 1 is connected through two jacks 3a and 3b and one rod 4 with tail shield 2.
The front end of tail shield 2 is engaged with the rear end of cutter head 1 so that cutter head 1 can be turned against tail shield 2 by actuating at the same time jacks 3a and 3b or by actuating selectively jack 3a or jack 3b.
Cutter head 1 is formed with partition 1b, by which the inside of shield tunneling machine A is divided into a first area on the ground side and a second area on the interior side.
Cutter is provided within the first area for excavating the ground.
Motor 6 for driving cutter 5 mounted on cutter head 1 and reflector 7 are provided within the second area on the interior.
Reflector 7 is secured to an end of arm 7a which other end is secured to partition 1b at a given distance from an axis 1a of cutter head 1.
Cutter 5 is provided with a plurality of spokes 5a to which a plurality of bits 5b are secured.
A reference point 8 into which shield tunneling machine A is controlled is set at the front end of cutter 5 on the axis 1a of cutter head 1, wherein a distance between reference point 8 and a turning point 1c on which cutter 5 is turned against tail shield 2 is set to a given amount L.
In the present embodiment, a beelining laser beam which goes straight is used, wherein the laser beam is sent along a scheduled line.
Therefore, while shield tunneling machine A is advanced on the scheduled line, laser beam 9 is sent along the axis 2a of tail shield 2.
Target 10 is provided within tail shield 2 on the axis 2a of tail shield 2 and behind reflector 7.
Target 10 is secured to a stay 11 secured to an inner wall of tail shield 2