JPS6238515B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an excavation device capable of digging a hole in the ground with a diameter larger than the diameter of a bit.

In conventional drilling equipment, a drill hammer body is connected to the bottom of a long drill rod via a connecting block, and a bit is provided at the bottom end of the drill hammer body, and the center of the drill rod is aligned with the center of the drill hammer body and the bit. It was designed so that a hole with a diameter almost equal to the diameter of the bit was dug, and it was not possible to dig a hole with a diameter larger than the diameter of the bit. For this reason, in order to dig a relatively large diameter hole, it was necessary to prepare a drilling device equipped with a large diameter bit.

For example, as seen in British Patent No. 1221607, a technique is known in which the part to which the bit is attached is swung around an eccentric axis to dig a hole with a diameter larger than the bit diameter. Not only is this complicated, but when drilling holes of different diameters, the entire main part of the drilling equipment located below the drill rod must be replaced with another one.

Therefore, it is an object of the present invention to make it possible to dig a hole with a diameter larger than the bit diameter using a simple mechanism, and to drill a hole larger than the diameter of the bit by simply replacing an inexpensive connecting block. The purpose of the present invention is to provide a drilling rig that can drill holes of any diameter.

Therefore, according to the present invention, in a drilling device in which a drill hammer body is connected to the lower part of the drill rod via a connecting block and a bit is provided at the lower end of the drill hammer body, the drill rod and the connecting block are detachably fixed. The connecting block and the drill hammer main body are fixedly connected to each other in a detachable manner with the axis of the drill hammer main body eccentric to the axis of the drill rod.

In this way, the drill rod and the connecting block, and the connecting block and the drill hammer body are fixed to each other when the device is assembled, so it operates stably like a conventional drilling device, and when you want to change the hole diameter. A hole of any diameter can be dug by simply replacing the connecting block with another one with a different eccentric distance.

Embodiments of the present invention will be described below with reference to the drawings. In the figure, a drilling device 1 has a drill rod 2, and a connecting block 3 called a head sub is fixedly connected to the lower part of the drill rod 2 in a detachable manner. This connection is performed by screwing together the male threaded portion 4 of the drill rod 2 and the female threaded portion 5 of the connecting block 3, and the axis of each threaded portion 4, 5 coincides with the axis C1 of the drill rod 2 and the connecting block ₃ . ing.
At the bottom of the connecting block 3 is a drill hammer body 6.
are eccentrically and removably fixedly connected, and this connection is achieved by threading the female threaded portion 7 of the connecting block 3 and the male threaded portion 8 of the drill hammer body 6. The axis _C2 of the drill hammer body 6 is eccentric by a distance _D1 with respect to the axis _C1 of the drill rod 2 and the connecting block 3, and this distance _D1 is approximately equal to 1/2 of the maximum bit diameter. the threaded portion 7;
The axis of 8 is also equal to the axis _C2 .

A bit 9 is provided at the lower end of the drill hammer body 6, and the outer circumferential surface of the bit 9 protrudes from the outer circumferential surface of the drill rod 2 by a distance _D2 .
The drill hammer main body 6 is covered with a cylindrical hammer cover 11 having substantially the same outer diameter as the drill rod 2. The upper end of the hammer cover 11 is screwed into the connecting block 3 at 12, and the middle part is separated by a screw connection 13. It is considered possible. Further, although not shown, reinforcing ribs are provided in the longitudinal direction on the outer circumferential surface and (or) on the inner circumferential surface of the hammer cover 11, and the reinforcing ribs on the outer circumferential surface serve as holes for drilling the shaft center C1 of the drill rod ₂ , etc. It also performs the function of maintaining the axial center of 14. Note that 10 and 15 are air passages formed in the connecting block 3 and the drill rod 2, and this air passage is also formed in the drill hammer body 6 to supply compressed air to the bit 9.

The drilling apparatus according to the embodiment of the present invention has the above-described construction, and at a location where a hole is to be dug, the drill rod 2 is suspended from a working machine (not shown) and the bit 9 is lowered onto the ground. Therefore, by supplying compressed air to the bit 9 through the air passages 15 and 10 and rotating the drill rod ₂ , the axis C2 of the drill hammer body 6 moves through the trajectory _C3 , and therefore the bit 9 The axis of
It is possible to move through C ₃ to drill a hole 14 of a larger diameter than the diameter of bit 9. Bit 9
The earth and sand dug by the hammer cover 11 is moved by compressed air sent through air passages 15 and 10.
It is discharged to the outside through the gap between the hole 14 and the hole 14. The diameter of the hole to be drilled can be easily changed by preparing and replacing several connecting blocks 3 with different eccentric distances _D1 .

As explained above, in the drilling equipment according to the present invention, the drill rod and the connecting block are fixedly connected to each other in a detachable manner, and the connecting block and the drill hammer body are arranged such that the axis of the drill hammer body is offset from the axis of the drill rod. Since the structure is such that the cores are fixed and connected removably, it is possible to dig a hole with a diameter larger than the diameter of the bit, and it is possible to prepare several connecting blocks with different eccentric distances and replace them. You can simply dig a hole of any diameter. In addition, when the device is assembled, the drill rod, connecting block and drill hammer body are integrated and operate stably like a conventional drilling device. Furthermore, in order to drill holes with different diameters, it is only necessary to prepare several connecting blocks with different eccentric distances, which are simple in construction and inexpensive to manufacture, and the overall construction is simple. The device can be manufactured at low cost and can be used for a long period of time without failure.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an excavating device according to an embodiment of the present invention, and FIG. 2 is a plan view for explaining the operation of the excavating device shown in FIG. 2...Drill rod, 3...Connection block, 6
...Drill hammer body, 9...Bits, 11...
...Hammer cover.

Claims (1)

[Claims] 1. In a drilling device in which a drill hammer body is connected to the lower part of a drill rod via a connecting block and a bit is provided at the lower end of the drill hammer body, the drill rod and the connecting block are fixedly connected in a detachable manner, and the connecting block and the drill The hammer body is a drilling device characterized in that the axis of the drill hammer body is eccentrically connected to the axis of the drill rod in a detachable manner.