JP3998198B2 - Kelever's drop shock absorber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drop impact absorbing device for a kelly bar in a borehole excavator having a telescopic kelly bar such as a kerry continuous wall machine or an earth drill.
[0002]
[Prior art]
The earth drill is a telescopic kelly bar, which is a combination of a plurality of cylindrical kerivas of different sizes, which can be expanded and contracted in multiple stages. A wire rope for suspension is connected to the bucket, a bucket is attached to the lower end of the kelly bar, the bucket in the fistula is rotated by the kelly bar driving device via the kelly bar, and when the bucket is filled with excavated soil, the wire The work of winding the rope, discharging the excavated soil in the bucket to the ground, and lowering the bucket into the hole again to perform excavation is repeated.
[0003]
In the excavation, excavation is performed in the initial stage of excavation in a state where the telescopic kelly bar does not extend, but when excavation proceeds to a depth at which the kelly bar extends, a flange-like stopper provided at the upper end of the outermost kelly bar (outer kelly bar) Excavation is carried out in a state where it is attached to the upper surface of the rotating part of the Keriba driving device. For this reason, every time the bucket is lowered and excavation is performed, the stopper collides with the upper surface of the rotating portion. If the keriva falls rapidly, there is a risk of damaging the keriber driving device and the hydraulic cylinder that supports the keriber driving device.
[0004]
In order to prevent such damage to the device, in Patent Document 1, a shock absorber made of a ring-shaped rubber plate or the like is provided on the upper surface of the rotating portion of the kelly bar driving device as a device that absorbs an impact when the kelly bar falls. Stacked and mounted, a steel plate ring for attachment is provided on the uppermost part, and the cushioning material is attached to the rotating part with attachment bolts. If such a drop impact absorbing device is provided for the kelly bar, when the kelly bar is dropped, the drop impact absorbing device can absorb the shock and avoid damage to the equipment.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 63-5552.
[0006]
[Problems to be solved by the invention]
In the drop impact absorbing device for the kelly bar described in the above-mentioned patent document, since a mounting ring made of a steel plate is provided on the uppermost surface of the cushioning material, the stopper at the upper end of the outer kelly bar is made of the steel plate when the kelly bar is dropped. When it collides with a ring, there is a problem that a contact sound between steels is generated and an impact is generated.
[0007]
In view of the above problems, an object of the present invention is to provide a drop impact absorbing device for a kelly bar that can prevent the generation of contact sound caused by the collision between steels when the kelly bar falls and reduce the impact.
[0008]
[Means for Solving the Problems]
(1) The drop impact absorbing device for a kelly bar according to the present invention has a cushioning material for receiving a flange-type stopper at the upper end of the outer kelly bar on the upper surface of a rotating part of a kelly bar driving device that is driven to rotate through a telescopic kelly bar of a borehole excavator. In the Kellyba drop impact absorbing device provided with a steel plate ring for mounting the cushioning material on the top surface of the cushioning material,
A buffer material is provided on the lower surface of the stopper or the upper surface of the ring.
[0009]
(2) Moreover, the drop impact absorber for a Keriba of the present invention is characterized in that the cushioning material has a structure divided in the circumferential direction.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view showing an embodiment of an earth drill to which a kelly bar drop impact absorbing device according to the present invention is applied. This ground drill is pivoted to the boom 2 or the crane body 1 at the lower part of the boom 2 attached to the front part of the crane body 1 so as to be raised and lowered, and the front frame 3 (in this example, a two-stage front frame). And a Keriba driving device 4 is attached to the upper part thereof.
[0011]
The rotating portion 4a of the kelly bar driving device 4 is provided with a driving hole extending vertically, and the telescopic kelly bar 5 is inserted into the driving hole so as to be movable up and down and not relatively rotatable. The kelly bar 5 is formed by fitting a plurality of kelly bars of different sizes so as to be extendable and non-rotatable, and is configured in, for example, a three-stage type, a four-stage type, a five-stage type, or the like. A bucket 6 is attached to the lower end of the innermost inner kelly bar 5a. In addition, a wire rope 8 is connected to the inner keliever 5 a via a swivel bell joint (rotary joint) 7. The wire rope 8 is wound around a sheave 9 at the top of the boom 2 and wound by a winch 10 on the crane body 1. It is drawn out.
[0012]
As shown in FIG. 2, on the upper surface of the rotating portion 4a of the kelly bar driving device 4, a plurality of buffer materials 11 made of a rubber plate or the like formed in a ring shape so as to penetrate the kelly bar 5 are provided. A ring 12 made of a steel plate is placed on the top of 11 and bolts 13 are inserted into holes provided in the buffer material 11 and the ring 12 and screwed into screw holes of a ring 18 fixed to the rotating portion 4a. 11 is mounted on the rotating part 4a.
[0013]
A steel plate flange-like stopper 14 for securing the outer kelly bar 5b is fixed to the upper end of the outer kelly bar 5b by welding or the like. On the lower surface of the stopper 14, a cushioning material 15 made of a rubber plate or the like that is placed on the ring 12 when the kelly bar 5 is dropped is attached.
[0014]
3 is a plan view of the outer kelly bar 5b, FIG. 4 is an enlarged cross-sectional view taken along line EE in FIG. 2, and FIG. 5 is an enlarged cross-sectional view taken along line FF in FIG. As shown in these drawings, the cushioning material 15 is divided into a plurality of pieces (three in the illustrated example) in the circumferential direction for easy mounting, and as shown in FIG. 15a is provided, and a through hole 15b is provided in the center of the recess 15a. A cylinder 16 for preventing overcompression is fitted into the through hole 15b, and a screw portion of the mounting bolt 17 is attached to the cylinder 16. The cushioning material 15 is attached to the lower surface of the stopper 14 by being inserted and screwed into a screw hole 14 a provided in the stopper 14. In this case, the head portion 17a of the bolt 17 is immersed in the concave portion 15a more than the maximum contraction amount H in consideration of the compression amount of the cushioning material 15 when the cushioning material 15 collides with the ring 12. Structure.
[0015]
Thus, if the buffer material 15 is provided on the lower surface of the stopper 14, the stopper 14 of the outer kelly bar 5 b does not directly collide with the steel plate ring 12 on the upper surface of the shock absorber 11 for shock absorption by dropping the kelly bar 5. Since it collides via the buffer material 15, generation | occurrence | production of the sharp contact sound of steel plates is prevented and the impact by the collision of a stopper is reduced.
[0016]
In the above embodiment, the cushioning material 15 is provided on the stopper 14. However, as shown in FIG. 6, the ring-shaped cushioning material is provided on the upper steel plate ring 12 of the cushioning material 11 provided on the upper surface of the rotating portion 4 a. 19 may be attached. In the example of FIG. 6, the shock absorber 19 is inserted onto the ring 12 by inserting the bolt 20 into the over-compression prevention cylinder 21 fitted in the hole 19 a of the shock absorber 19 and screwing it into the screw hole 12 a of the ring 12. Fixed. Thus, if the buffer material 19 is provided in the ring 12 and the stopper 14 is made to collide with the buffer material 19, the generation of contact noise between the steels can be prevented and the impact can be reduced as described above.
[0017]
When the present invention is carried out, a cushioning material may be provided on both the lower surface of the stopper 14 and the upper surface of the ring 12. The present invention can also be applied to an earth drill having a configuration in which the kelly bar is rotated by a kerry bar driving device that moves up and down along the reader, and can also be applied to a kelly continuous wall machine.
[0018]
【The invention's effect】
According to the present invention, the shock absorber is provided on the lower surface of the stopper of the outer kelly bar or the steel plate ring on the upper surface of the shock absorber provided on the rotating portion of the kelly bar driving device, so that the contact noise between the steels is prevented and the impact is applied. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of an earth drill to which a kelly bar drop impact absorbing device according to the present invention is applied.
FIG. 2 is a side view showing an embodiment of a drop impact absorbing device for a Keriba according to the present invention.
FIG. 3 is a plan view of an outer keriva according to the present embodiment.
4 is an enlarged cross-sectional view taken along the line E-E in FIG. 2;
5 is an enlarged cross-sectional view taken along the line F-F in FIG. 3;
FIG. 6 is a side cross-sectional view showing another embodiment of the drop impact absorbing device for a Keriba of the present invention.
[Explanation of symbols]
1: Crane body, 2: Boom, 3: Front frame, 4: Keriva drive unit 4a: Rotating part, 5: Keriva, 5a: Inner keriva, 5b: Outer keriva, 6: Bucket, 7: Swivel bell joint, 8: Wire rope 9: Sheave, 10: Winch, 11: Buffer material, 12: Steel plate ring, 13: Bolt, 14: Stopper, 15: Buffer material, 15a: Recess, 15b: Through hole, 16: Tube for preventing overcompression 17: bolt, 17a: head, 19: cushioning material, 20: bolt, 21: cylinder for preventing overcompression

Claims (2)

A cushioning material for receiving a flange-type stopper at the upper end of the outer kelly bar is provided on the upper surface of the rotating part of the kelly bar driving device that is inserted into the telescopic kerry bar of the borehole excavator to rotate, and for mounting the cushioning material on the upper surface of the cushioning material In Kellyba's drop shock absorber with a steel plate ring,
A kelly bar drop impact absorbing device, wherein a cushioning material is provided on a lower surface of the stopper or an upper surface of the ring. In the Kellyba drop impact absorbing device according to claim 1,
The shock absorber of Kellyba, wherein the cushioning material has a structure divided in a circumferential direction.

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