JPH0417663Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a Kelly bar for driving the excavation bucket of an earth drill.

[Conventional technology]

Kerry bars used in earth drills, which are one type of large-diameter vertical hole drilling machine, generally have a square cross section.
A three-stage or four-stage telescopic type is used, which has a second kelly lever, an outer kelly lever, etc. installed on the outside of the inner kelly lever, and while this kelly lever is rotated by a rotary drive device, the kelly bar is expanded and contracted to perform excavation and earth removal work. .

However, since water (or bentonite water) is normally used for excavation work, if muddy water enters the keel and the kelly bar shrinks during soil removal, the stopper plate of the outer kelly bar, etc. inserted through the inner kelly bar, will become stuck between each kelly bar. Close the space between the lower ends of
This will obstruct drainage.

Therefore, in the past, a notch for draining water was provided at the bottom of the second kelly lever and the outer kelly lever.

[Problem that the invention attempts to solve]

However, in order to shorten the drainage time, making this notch larger would cause problems in terms of the strength of the Keliva, so only small notches could be made.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an earth drill kelly bar that can reduce drainage time and excavation work time without reducing the strength of the kely bar.

[Means for solving problems]

In order to achieve the above object, the present invention provides a keel lever for an earth drill in which an outer keel lever is slidably fitted onto an inner keel lever, a stopper plate that abuts the lower end of the outer kelly lever is inserted into the inner kelly lever, and a water drain portion is provided in the stopper plate. It is characterized by

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

1 to 4 show a first embodiment of the present invention, in which an earth drill 1 has a front frame on which a rotary drive device 4 is mounted at the bottom of a boom 3 attached to the front part of a crane body 2. The Kelly lever 6 inserted into a square hole (not shown) of the rotary drive device 4 is suspended by a Kelly rope 8 via a swivel joint 7, and is attached to a winch provided on the crane body 2. It can be raised and lowered by winding up and unwinding 9.

This kelly lever 6 is configured to be extendable and retractable by four stages of rectangular tubes including a second kelly lever 12, a third kelly lever 13, and an outer kelly lever 14 which are slidably fitted on the outside of the inner kelly lever 11. is connected, and a bucket 15 is attached to the lower end.

Further, a stopper plate 16 is inserted through the upper part of the buffer spring 17 at the lower end of the inner lever 11 and comes into contact with the lower ends of the second, third, and outer levers 12, 13, and 14 to prevent them from coming off.

As shown in FIG. 4, this stopper plate 16 is made thicker than the conventional stopper plate, and four drainage grooves 18 are formed at each corner of the upper surface.

Furthermore, cutouts 12a, 13a, and 14a for draining water are formed at the lower ends of the second kelly lever 12, the third kelly lever 13, and the outer kelly lever 14, as in the prior art.

With this configuration, there are more drainage points than in the past, and drainage is actively carried out from the corners with large gaps due to the structure, which shortens the drainage time and reduces the excavation time of the earth drill 1. In addition to being shortened, the drainage is carried out smoothly, so the dirt that has entered into the Kelly bar 6 is smoothly discharged, and there is less accumulation of dirt, so it is possible to prevent the Kelly bar 6 from being unable to expand or contract due to dirt, etc. can be reduced.

FIG. 5 shows a second embodiment of the present invention, in which the drainage groove 20 is formed by drainage notches 12a, 13a, 14a formed at the lower ends of the second kelly lever 12, third kelly lever 13, and outer kelly lever 14.
This is formed on the upper surface of the stopper plate 21 in correspondence with the second kelly lever 12, third kelly lever 13, outer kelly lever 14 and stopper plate 21, thereby increasing the notch area for drainage and shortening the drainage time. This prevents the contact area from decreasing.

Furthermore, as shown in the third embodiment of FIG.
A plurality of drain holes 22 may be provided through the stopper plate 23 within the range permitted by the material strength.

Furthermore, a drainage groove and a drainage hole may be used together.

[Effect of idea]

As described above, in this invention, drainage parts such as grooves and holes are formed in the stopper plate of the outer kelly bar, etc., which is inserted into the inner kelly bar of the multi-stage kelly bar, so that muddy water, etc. that enters the kelly bar during excavation work can be discharged. It can save time and improve work efficiency.

[Brief explanation of the drawing]

1 to 4 show the first embodiment of the present invention, in which FIG. 1 is a front view of the earth drill, FIG. 2 is a partially sectional front view of the Kerryba, and FIG. - sectional view, FIG. 4 is a perspective view of the stopper plate, FIG. 5 is a perspective view of the stopper plate of the second embodiment of the present invention, and FIG. 6 is a perspective view of the stopper plate of the third embodiment of the present invention. FIG. 1...Earth Drill, 6...Keriba, 11...
...Innakereba, 12...Secondkereba,
13... Third Kellyba, 14... Outer Kellyba, 16, 21, 23... Stoppa plate, 1
8, 20...Drainage groove, 22...Drain hole.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a keel lever of an earth drill in which an outer keel lever is slidably fitted onto an inner keel lever, a stopper plate that abuts the lower end of the outer kelly lever is inserted into the inner kelly lever, and a water drain portion is provided in the stopper plate. Kerryba is an earth drill that is characterized by the provision of. (2) The earth drill Kelly bar according to claim 1, wherein the water draining portion is a groove formed on the upper surface of the stopper plate. (3) The earth drill Kerryba according to claim 1, wherein the water drain portion is a through hole drilled in the stopper plate.