JP2651723B2 - Sand layer drilling method and drilling ring bit with easy drilling direction correction - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an excavation method for excavating a sand layer or soft ground using a ring bit and an improvement of the ring bit.

(Prior Art) A conventional ring bit has a plurality of bits attached to the periphery of an opening perpendicular to the rotation axis of the ring bit at the tip of the tube.

Further, in the conventional method of excavating a sand layer using this ring bit, excavation can be performed only in a straight line, and in order to correct the direction on the way, the excavation must be withdrawn from the excavation hole and re-excavated from the beginning or shortly before. Therefore, the workability was deteriorated.

(Problems to be Solved by the Invention) The problem to be solved by the present invention is to solve the conventional disadvantages and to gradually correct the direction of excavation while advancing the excavation, thereby making excavation work easy and efficient. It is an object of the present invention to provide a sand layer excavation method and an excavation ring bit that can easily correct the excavation direction.

(Means for Solving the Problems) The gist of the present invention that has solved the problems is as follows. 1) A ring bit for excavating a sand layer by attaching a plurality of bits to a peripheral end of a pipe and rotating while giving a blow or a pressing force. In this case, while the plane formed by the periphery of the pipe tip is inclined so as to be oblique to the rotation axis of the ring bit,
2. A sand layer excavation ring bit wherein an opening formed by the peripheral edge is closed by a closing plate, and a sediment intake port is opened on a front peripheral portion of the closing plate. When the ring bit is rotated at least 360 ° to excavate the ring bit straight, and then when you want to change the direction of excavation, position the ring bit in the phase where the intake comes in the direction to be corrected. The present invention provides a sand layer excavation method in which the excavation direction can be easily corrected, wherein the excavation direction of the ring bit is changed by giving a swing motion to the ring bit in a narrow angle range around this phase.

(Operation) If the ring bit of the present invention is given a rotation of 360 ° or more at the same sand layer while applying a striking or pressing force, the bit at the tip breaks down the sand layer, and the sediment of the sand layer is removed by the sediment intake of the closing plate. From the ring bit. Since the ring bit rotates 360 ° or more, the cutting condition of the sand layer and the state of taking in the earth and sand become uniform 360 °, and the ring bit excavates straight.

Next, if you want to correct the direction of the excavation, rotate the ring bit so that the sediment intake is in the correct direction, and swing the ring bit around a ± 45 ° angle range ring bit around this phase. If given, the sediment in the sand layer is strongly removed at the location of the sediment intake, and the ring bit is propelled toward the direction of the sediment intake. As described above, in the present invention, the digging direction can be gradually corrected to an arbitrary direction while digging.

(Example) Hereinafter, an example is described.

FIG. 1 is a longitudinal sectional view showing a tip of an embodiment of the ring bit of the present invention, FIG. 2 is a front view of the same, and FIG.

The ring bit (1) shown in the drawing is the periphery of the pipe tip (2).
The inclination angle of the plane formed by the above, that is, the closing plate (3) is 45 °. The intake port (4) is opened at about 1/8 of the area of the closing plate at the peripheral edge on the tip side of the closing plate (3).
The swing angle of the swing rotation for correction was set to ± 45 ° at the center of a certain phase of the intake (4). As a result, the excavation of the sand layer made it easy to go straight and correct the direction. Examples are shown in FIGS. 3 (a), (b) and (c). FIG. 3 (a) shows a state in which horizontal excavation has been performed at full rotation, and the pipe has begun to ascend. FIG. 3 (b) shows a state in which the intake port (4) is turned downward, and the direction is corrected by giving a right and left swing motion to an angle range of ± 45 ° around the intake port (4). FIG. 3 (c) shows a state in which the ring bit is returned to a predetermined horizontal position after the direction correction, and excavation is performed at full rotation.

(Effects of the Invention) As described above, according to the present invention, only by swinging and rotating the ring bit of the present invention having an inclined closing plate and a peripheral intake, the excavation direction is gradually increased while excavating. Therefore, there is an effect that the workability is high and the work is easy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a tip portion of an embodiment of a ring bit of the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a process diagram showing an embodiment of a sand layer excavating method of the present invention in which the excavation direction can be easily corrected. It is. (1): ring bit, (2): peripheral edge of pipe end (3): closing plate, (4): intake

Claims (2)

(57) [Claims] In a ring bit for excavating a sand layer by attaching a plurality of bits to a peripheral edge of a pipe and rotating while applying a blow or a pressing force, a plane formed by the peripheral edge of the pipe is used as a rotation axis of the ring bit. A ring bit for sand layer drilling, characterized in that the ring bit is inclined so as to be oblique, the opening formed by the peripheral edge is closed by a closing plate, and a sediment inlet is opened in the front peripheral portion of the closing plate. 2. The ring bit for sand layer excavation according to claim 1, wherein the ring bit is excavated in a straight line by giving a rotation of at least 360 ° or more, and when the excavation direction is to be changed next, the direction to be corrected is changed. The drill bit is positioned in the phase where the intake comes in, and the drill bit is changed in direction by giving swing motion to the ring bit in a narrow angle range around this phase. Sand layer drilling method.