Abstract: In an excavation tool of the present invention, an embedding hole is drilled in a distal end portion of a tool body which is rotated about an axis line O and is moved forward to a distal end side in a direction of the axis line O. In the embedding hole, an excavation tip in which an embedding portion having an outer cylindrical shape is formed integrally with a cutting edge portion inserts the embedding portion into the embedding hole and causes the cutting edge portion to protrude from the embedding hole. In this manner, the excavation tip is rotatable around a central axis C of the embedding portion during excavation, and is attached thereto by being locked so as not to slip toward a distal end side of the embedding portion 6 in a direction of the central axis C.

Abstract: In an excavation tool of the present invention, an embedding hole is drilled in a distal end portion of a tool body which is rotated about an axis line O and is moved forward to a distal end side in a direction of the axis line O. In the embedding hole, an excavation tip in which an embedding portion having an outer cylindrical shape is formed integrally with a cutting edge portion inserts the embedding portion into the embedding hole and causes the cutting edge portion to protrude from the embedding hole. In this manner, the excavation tip is rotatable around a central axis C of the embedding portion during excavation, and is attached thereto by being locked so as not to slip toward a distal end side of the embedding portion 6 in a direction of the central axis C.

Abstract: Provided is an excavation tool for efficiently taking waste rocks produced during excavation into the inner peripheral side of a casing pipe. An excavation tool (10) includes a casing shoe (11), a casing pipe (15), a rod (60), a device (40), and an excavation bit (20). The excavation bit (20) has a head portion (22) and a skirt portion (23). The head portion (22) is provided with: a face flute (27), which is open into the tip face of the head portion and extends radially outward; a connection flute (28), which is integrally connected to the outer peripheral end of the face flute (27) and extends toward the rear end side, and an intake hole (29), which is integrally connected with the discharge flute (46) of the device (40) and is open to the inner peripheral side of the skirt portion (23) from the connection flute (28).

Abstract: The present invention relates to a hollow drilling steel rod including a stem portion and a thread portion positioned at an end portion in an axial direction with respect to the stem portion, the hollow drilling steel rod being constituted of a steel having a specific composition described in the present specification, in which the thread portion includes a thread having been subjected to a high frequency quenching, and the thread portion and the stem portion separate from each other have been joined by a friction welding.

Abstract: The present invention relates to a hollow drilling steel rod including a stem portion and a thread portion positioned at an end portion in an axial direction with respect to the stem portion, the hollow drilling steel rod being constituted of a steel having a specific composition described in the present specification, in which the thread portion includes a thread having been subjected to a high frequency quenching, and the thread portion and the stem portion separate from each other have been joined by a friction welding.

Abstract: Provided is an excavation tool for efficiently taking waste rocks produced during excavation into the inner peripheral side of a casing pipe and discharging the waste rocks to the outside. An excavation tool (10) includes a casing shoe (11), a casing pipe (15), a rod (60), a device (40), and an excavation bit (20). A discharge flute (46) for discharging the waste rocks is formed in the outer peripheral surface of the device (40). The excavation bit (20) has a head portion (22) and a skirt portion (23). The device (40) can be inserted into the inner periphery of the skirt portion (23).

Abstract: An excavation tool, in which a device is provided which receives the striking force of a hammer and the rotational force of a hammer cylinder, in a bottom surface of which at least three axle holes are provided displaced from a center of the device and at equivalent angular intervals in the circumferential direction, block axles are inserted in the axle holes in a freely rotatable manner, blocks which are roughly fan-shaped and have bits embedded in the lead end surfaces thereof are provided at lead end parts of the block axles, so that left- and right-side faces of said blocks are in mutual opposition and arc parts of all blocks together form roughly a circle shape; and when said device is rotated in the direction of excavation, said blocks rotate as a result of the resistance to excavation of the bottom part of the excavation hole, one intersection part of the side faces and the arc part of each block protrudes beyond the outer circumferential surface of the device by a predetermined excavation amount, and

Abstract: An excavation tool, having a pair of insertion holes placed in the bottom surface of a device, which receives the impact force of a hammer and the rotational force of a hammer cylinder, at positions separated in a radial direction from the center of the device and symmetrical around this center as a center of rotation, also having block axles, one end of each of which is freely rotatably inserted into one of the insertion holes, and having blocks, which have a roughly semicircular shape with a diameter roughly equal to that of the device, into the lead end surfaces of which are set bits, and which have straight edge surfaces which are flat surfaces vertical with respect to the lead end surfaces, provided at the other end of the block axles and with the straight edge surfaces in mutual opposition; in an extended diameter state of the blocks, the blocks are moved in opposite directions along a radius of the device by rotating the blocks around the block axles, and the distance between the centers of the inserti