US 12,467,320 B2
Ground drilling device
Satoshi Anzai, Yokohama (JP)
Assigned to Satoshi Anzai, Yokohama (JP)
Appl. No. 18/024,175
Filed by Satoshi Anzai, Yokohama (JP)
PCT Filed Sep. 13, 2021, PCT No. PCT/JP2021/033504
§ 371(c)(1), (2) Date Mar. 1, 2023,
PCT Pub. No. WO2022/054937, PCT Pub. Date Mar. 17, 2022.
Claims priority of application No. 2020-154059 (JP), filed on Sep. 14, 2020.
Prior Publication US 2023/0272674 A1, Aug. 31, 2023
Int. Cl. E21B 10/60 (2006.01); E21B 21/01 (2006.01); E21B 21/06 (2006.01); E21D 9/06 (2006.01)
CPC E21B 10/602 (2013.01) [E21B 21/01 (2013.01); E21B 21/062 (2013.01); E21D 9/0678 (2016.01)] 2 Claims
OG exemplary drawing
 
1. A ground drilling device comprising:
a rotary blade that excavates a ground;
a lubricating liquid jetting device that jets a lubricating liquid to the rotary blade when excavating the ground; and
an oxygen supply device that is disposed on the ground and supplies oxygen to the lubricating liquid,
wherein the oxygen supply device includes a bubble generating medium for supplying oxygen having a pressure up to 1.5 megapascals (MPa) higher than the atmospheric pressure as fine bubbles to the lubricating liquid,
the ground drilling device being a shield machine and further comprising:
a drilling cutter having a plurality of the rotary blades;
a partition wall having a cylindrical shape to which the drilling cutter is attached;
a drilling chamber formed by the partition wall;
a mud outlet opened in the partition wall;
a high-concentration mud water facility that is disposed on the ground and mixes an injection material and an excavated soil to prepare a high-concentration mud water as the lubricating liquid;
a discharged mud introducing pipe having one end communicated with the mud outlet to discharge an excavated soil and sand in the drilling chamber;
a suction tank that is disposed on the ground and on one side of the high-concentration mud water facility; and
a discharged mud conveying pipe that is connected to the suction tank and conveys the excavated soil and sand up to the ground,
wherein
the lubricating liquid jetting device includes: a first jetting device that jets the high-concentration mud water as the lubricating liquid from the high-concentration mud water facility to a front of the drilling cutter; and a second jetting device that jets the high-concentration mud water as the lubricating liquid from the high-concentration mud water facility to an outer peripheral portion of the partition wall,
the bubble generating medium of the oxygen supply device discharges the oxygen having the pressure as the fine bubbles into the high-concentration mud water when the injection material and an excavated soil are mixed in the high-concentration mud water facility, and
the bubble generating medium is formed of a carbon-based porous material.