Non-contact type pile cutting apparatus using waterjet and cutting method thereof

Abstract

The present disclosure relates to a non-contact type pile cutting apparatus using a waterjet, particularly to a pile cutting apparatus entering the inside for cutting a pile including: a body that has a pipe form and is put into an inside of the pile; a gripper unit that is provided at an outer side of the body and fixes the body to the pile when the pile cutting apparatus has reached a cutting position of the pile; a waterjet unit that is provided at one side of the body and fixed by the gripper unit, and then sprays an abrasive mixture in which an abrasive and a fluid are mixed, toward the pile in a high pressure; a rotation unit that rotates the waterjet unit around a central axis of the body; a feed line that feeds the abrasive mixture in which the fluid and the abrasive of a set ratio are mixed, to the waterjet unit from the outside; a feed unit that controls a feed pressure of the abrasive mixture fed through the feed line; and a nozzle driving unit that controls a position of the waterjet unit.

1 . A non-contact type pile cutting apparatus using a waterjet, as a pile cutting apparatus entering the inside for cutting a pile, comprising:
 a body that has a pipe form and is put into an inside of the pile;   a gripper unit that is provided at an outer side of the body and fixes the body to the pile when the cutting apparatus has reached a cutting position of the pile;   a waterjet unit that is provided at one side of the body and fixed by the gripper unit, and then sprays an abrasive mixture in which an abrasive and a fluid are mixed, toward the pile in a high pressure;   a rotation unit that rotates the waterjet unit around a central axis of the body;   a feed line that feeds the abrasive mixture in which the fluid and the abrasive of a set ratio are mixed, to the waterjet unit from the outside;   a feed unit that controls a feed pressure of the abrasive mixture fed through the feed line; and   a nozzle driving unit that controls a position of the waterjet unit.   
     
     
         2 . The non-contact type pile cutting apparatus using a waterjet of  claim 1 , further comprising:
 a casing which is connected to a lower part of the body, and in which an opening provided as a passage where a nozzle portion of the waterjet unit is protruded and inserted is formed, wherein   the rotation unit is installed inside the casing, and   the waterjet unit comprises:   a nozzle housing in which the nozzle portion that is connected to the feed line and sprays the abrasive mixture toward the pile in a high pressure is provided;   a nozzle moving unit that moves the nozzle portion in a radial direction of the pile in the nozzle housing; and   a guide portion which is provided at one side of the nozzle housing and is in contact in a state that the nozzle portion is being moved toward an inner surface of the pile by the nozzle moving unit, thus maintaining a distance between an end of the nozzle portion and the inner surface of the pile within a set range.   
     
     
         3 . The non-contact type pile cutting apparatus using a waterjet of  claim 2 , further comprising:
 a nozzle setting unit that performs rotation from an inner side of to an outer side of the casing of the nozzle housing, or reversely, wherein   the guide portion comprises:   a rotation roller that is spaced apart from the nozzle portion at a predetermined interval in a length direction, and is provided at a position protruded toward an outer side of the nozzle portion;   a tension unit that gives an elastic force to the rotation roller in an outer radial direction while allowing moving the rotation roller in a radial direction; and   a tension detection portion that measures the elastic force of the tension unit in real time, and   a control portion controls the nozzle moving unit so as to fix a radial direction position of the nozzle portion when the elastic force detected from the tension detection portion has reached a set range.   
     
     
         4 . The non-contact type pile cutting apparatus using a waterjet of  claim 1 , wherein
 the gripper unit has a link structure and comprises:   a plurality of gripper members that is pressurized to and contacted with an inner side of the pile, when performing fixation to the body; and   a link driving portion that moves the gripper member toward the pile during fixation, while moving the gripper member toward the body when performing release.   
     
     
         5 . The non-contact type pile cutting apparatus using a waterjet of  claim 4 , wherein
 a plurality of protrusions is installed on an outer surface of the gripper member,   the link driving portion comprises:   a cylindrical shaped movable housing that moves up and downwardly while covering an outer surface of the body; and   a driving link that is installed in a radial direction of the movable housing and drives the movable housing up and downwardly,   the link structure comprises:   a connection link of which an inner end is hinge-connected with the driving link, and of which an outer end is hinge-connected to one side of the gripper member;   an upper link of which an inner end is hinge-connected with an upper connection end installed to one side of an upper outer surface of the body, and of which an outer end is hinge-connected with an upper side of the gripper member; and   a lower link of which an inner end is hinge-connected with an lower connection end installed to one side of a lower outer surface of the body, and of which an outer end is hinge-connected with a lower side of the gripper member, and   the gripper member is spread out toward the pile when the movable housing has been moved to a top part by the driving link, while being folded when the movable housing has been moved to a bottom part.   
     
     
         6 . The non-contact type pile cutting apparatus using a waterjet of  claim 5 , further comprising:
 a determination portion that comprises a sound sensor provided at the nozzle housing and measuring sound data during work, and a vibration sensor measuring a vibration state of the nozzle housing, wherein   the determination portion determines that the pile has been cut when a sound signal and a vibration value measured from the sound sensor and the vibration sensor are within set ranges.   
     
     
         7 . The non-contact type pile cutting apparatus using a waterjet of  claim 6 , further comprising:
 database (DB) where stored are a pile thickness, ranges of sound data and vibration during cutting by the abrasive mixture according to materials, and ranges of sound data and vibration following penetration by the abrasive mixture, wherein   the determination portion determines as to whether the pile has been cut or not, based on ranges of the sound data and vibration stored in the DB, and   the control portion moves the nozzle housing in a circumferential direction up to a set angle by driving the rotation unit when the determination portion determines that the pile has been penetrated by a waterjet.   
     
     
         8 . A method for cutting a pile through a non-contact type pile cutting apparatus using a waterjet comprising steps of:
 putting a pile cutting apparatus into an inside of a pile through a putting apparatus;   fixing the pile cutting apparatus to the inside of the pile by operating a gripper unit by a control portion when the pile cutting apparatus has reached a cutting position of the pile;   setting a waterjet to move a waterjet unit provided at one side of a body toward an inner surface of the pile through a nozzle driving unit;   feeding an abrasive mixture in which a fluid and an abrasive of a set ratio are mixed, to a feed line with the waterjet unit from the outside by a feed unit, and spraying the abrasive mixture toward the pile in a high pressure from a nozzle portion of the waterjet unit, which is connected to the fee line; and   cutting the pile by rotating the waterjet unit around a central axis of the body by a rotation unit.