ENLARGED DRILLING APPARATUS AND ENLARGED DRILLING METHOD

• Main Authors: ITAGAKI KOZO, TANI KIYOAKI, SAKAMOTO MASAHIKO, MAENISHI MASANORI, HIRAKAWA ETSUO, MIYAMOTO KAZUYUKI, SATO HIDETO
• Format: Patent
• Language: English; Japanese
• Published: 26.04.2018
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

PROBLEM TO BE SOLVED: To solve the problem in which, in a configuration where an enlarged arm is passed through in a cross direction, the enlarged arm is lowered by degrees while expanding the enlarged arm as enough vertical width of the enlarged arm cannot be achieved, and therefore drilling operation time becomes longer, or, in a configuration of pivoting the enlarged arm at vertical axis, the drilling length of the enlarged arm becomes longer and for that the drilling surface pressure is lowered and the applicable ground is limited.SOLUTION: A holding fixing device 23 which abuts the inner peripheral surface of the casing K to be fixed with a casing K is arranged, and an upper portion of an enlarged head H which performs an enlarged drilling of a conical slant portion 11 having a larger diameter than a vertical hole 6 and a cylindrical rising hole portion 16 below of the slant portion 11 to the soil W is mounted to said holding fixing device 23. The enlarged drilling apparatus configures a slant drilling head 12 configured to have an enlarged blade 14 which is pivotable by the attachment shaft 13 of a lateral axis core and drills the slant portion 11 of an enlarged hole 8 and a rising drilling head 20 configured to have an enlarged arm 21 which moves in a cross direction toward a shaft center of the vertical hole 6 in an exchangeable manner.SELECTED DRAWING: Figure 10 【課題】交差方向に拡大アームを出入りさせる構成では、拡大翼の上下幅を十分に取れないので、拡大翼を拡開させながら少しずつ下降させることになり、掘削作業時間が長くなる。また、縦軸心に拡大翼を回動させる構成では、拡大翼の掘削長が長くなり、そのため、掘削面圧が低下し、適用地盤が限られる。【解決手段】 ケーシングＫの内周面に当接してケーシングＫと固定状態とする保持固定装置２３を設け、該保持固定装置２３に、地盤Ｗに縦孔６よりも大径の円錐状の斜面部１１と斜面部１１の下方の円柱状の立上がり孔部１６とを拡大掘削する拡大ヘッドＨの上部を取付け、該拡大ヘッドＨは、横軸芯の取付軸１３により回動自在であって拡大孔８の斜面部１１を掘削する拡大翼１４を有して構成する斜面掘削ヘッド１２と、縦孔６の軸心に対して交差方向に移動する拡大アーム２１を有して構成する立上がり掘削ヘッド２０とを交換自在に構成した拡大掘削装置。【選択図】図１０