JPH06240970A - Earth drill - Google Patents

Abstract

PURPOSE:To make the insertion of a kelly-bar smoothly performable by maintaining the extent of verticalness in this kelly-bar. CONSTITUTION:A kelly-bar 4 is supported at two spots up and down with a kelly-drive unit 7 attached to an upper frame 6 of a front frame and a guide unit 14. In addition, a guide pin 12 and a locating pointer 13 both are attached to a lower part of this kelly-drive unit 7. Likewise, the guide unit 14 is provided with a locating pointer 20 according with the locating pointer 13 of the kelly- drive unit 7 and a guide pin inserting hole whose phase is accords with that of the guide pin 12 in an accordant state between both locating pointers 13 and 20, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth drill for excavating a vertical hole in the ground.

[0002]

2. Description of the Related Art The body of a conventional earth drill comprises a traveling type crane 1 having a boom 2 as shown in FIG. 1, and a hoisting rope 8 of the crane 1 supports an excavation bucket 3. The excavation bucket 3 is attached to the lower end of the kerry bar 4, and the kerry bar 4 is attached to the upper frame 6 of the front frame 5 so as to be vertically movable via a thrust cylinder.
Has been inserted into the hole. The upper end of the kelly bar 4 is connected to the hoisting rope 8 via a joint fitting 9 such as a swivel joint. The hoisting rope 8 is unwound from a winch 10 installed in the main body and is hung on a sheave 11 attached to the tip of the boom 2. By driving the kelly drive device 7, the kerry bar 4 and the excavation bucket 3 are rotated.

[0003]

Such an earth drill has a problem that the excavation bucket causes a so-called miso movement during excavation work, and the center position of the pile hole cannot be determined.

The present invention has been made in view of the above, and supports the kerry bar at two positions, a kerry drive device and a guide device, above and below, and further, a hole for inserting the kerry bar of both devices, or alignment of the hole and the key groove. It is an object of the present invention to provide an earth drill that can easily perform.

[0005]

In the earth drill of the present invention, a guide device for receiving a kerry bar is provided on a front frame provided with the kerry drive device, and the kerry bar is supported at two upper and lower positions of the kerry drive device and the guide device. The guide pin and the positioning pointer are attached to the lower portion of the Kelly drive device, and the guide device is aligned with the positioning pointer of the Kelly drive device and the positioning pointer and It is characterized in that a guide pin insertion hole whose phase matches the guide pin is provided.

[0006]

[Operation] When the work setup of the earth drill is lowered, if the positioning pointer of the device is brought into alignment with the positioning pointer of the guide device, the guide pin of the kelly drive device and the pin hole of the guide device match. To do. When the kelly drive device is further lowered in that state, the guide pin is inserted into the pin hole, and the kerry drive device and the hole for inserting the kerry bar of the guide device, or the hole and the key groove are aligned. In that state, the kelly bar is inserted into both devices. During excavation work, the kerry bar is supported by the kerry drive device and the guide device at two upper and lower positions.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an earth drill having a round kelly bar will be described below with reference to FIGS.

Guide frames are formed on the left and right of the upper frame 6 of the front frame 5, and a kelly drive device 7 is attached to the guide frames so that the guide frames can be moved up and down through a thrust cylinder (not shown). Has been. The kelly drive device 7 has a geared shaft that is driven by a hydraulic motor 25 with a pinion, like a normal one, and the geared shaft has a hole 7a into which the cylindrical portion of the round kelly bar 4 is inserted. A plurality of, for example, three, keys 4a provided in the longitudinal direction are provided on the peripheral wall of the round kelly bar 4 and key grooves 7b into which the keys 4a are respectively inserted. The geared shaft is supported by the upper frame 6 via a bearing. A guide pin 12 and a positioning pointer 13 are attached to the peripheral portion of the lower end of the Kelly drive device 7.

At the bottom of the upper frame 6, a guide device 1 is provided.
4 is rotatably supported. The lower plate 15 of the guide device 14, the rotational force transmitting piece 16 fixed to the lower plate 15 by a bolt, and the upper plate 17 are provided with a hole through which the round kelly bar 4 is inserted and a key groove 14a into which the key 4a is inserted. It is provided. Brackets 25 are attached on the lower plate 15 at intervals in the circumferential direction, and a shaft 19 supporting a guide roller 18 for receiving the round kelly bar 4 is attached to each bracket 25. The guide roller 18 serves to maintain the vertical accuracy of the kelly bar 4 and does not receive a rotational force. A positioning pointer 20 for matching the positioning pointer 13 of the Kelly drive device 7 is attached to the upper plate 17, and a pin that is in phase with the guide pin 12 of the Kelly drive device 7 when the pointers 13 and 20 are in a matched state. A hole 21 is provided. In the inner peripheral edge portion between the key grooves 14a of the upper plate 17, in the non-matching state of the key groove 7b of the Kelly drive device 7 and the key groove 14a of the guide device 14,
An arcuate receiving plate 22 that receives the lower end of the key 4a of the round kelly bar 4 is attached.

A center joint 23 for sending pressure oil to a hydraulic cylinder of an expanded bottom excavating bucket is installed under the upper frame 6, and a reel table 24 having a hose reel and a cable reel mounted under the center joint 23. Is installed.

The round kelly bar 4 is not inserted into the kelly drive device 7 when the ground drill is set up.
In order to put it into a working state, the kelly drive device 7 is rotated so that the guide pin 12 does not hit the guide device 14, and the positioning pointer 13 is aligned with the positioning pointer 20 as shown in FIG. At this time, since the guide pin 12 and the pin hole 21 are in phase with each other, the guide pin 12 is inserted into the pin hole 21 by further lowering the Kelly drive device 7. In this state, the key groove 7b of the kelly drive device 7 and the key groove 14a of the guide device 14 coincide with each other. Therefore, when the round kelly bar 4 is inserted from above, the key 4a of the round kerry bar 4 and the key of the kerry drive device 7 are inserted. The alignment with the groove 7b can be easily performed by rotating the Kelly drive device 7. The alignment between the Kelly drive device 7 and the guide device 14 can be performed by means such as a limit switch instead of using a pointer, and in that case, further automation will result. As mentioned above,
Since the key groove 7b of the kelly drive device 7 and the key groove 14a of the guide device 14 are aligned with each other, the round kerry bar 4 can be smoothly inserted. In addition, after the Kerry drive device 7 and the guide device 14 are aligned,
Even when the kelly drive device 7 is raised as shown in (4), the round kelly bar 4 can be inserted without trouble.

In the state of FIG. 5, when the phase of the key groove 7b of the kelly drive device 7 and the key groove 14a of the guide device 14 do not match, if the round kerry bar 4 is inserted,
The round kelly bar 4 comes into contact with the guide device 14 after passing through the kelly drive device 7, but the lower end of the key 4a is received by the receiving plate 22 and the round kelly bar 4 stops at that position. As a result, it is possible to prevent the key 4a from hitting and damaging the guide roller 18 and the like.

During excavation work, the round kelly bar 4 is supported by the kerry drive device 7 and the guide device 14 at two upper and lower positions.

[0014]

According to the first and second aspects of the present invention, since the kerry bar is vertically supported at the upper and lower two places of the kerry drive device and the guide device, the verticality of the kerry bar is maintained and the displacement of the center of the pile hole is prevented. This makes it possible to construct piles with high accuracy.
Moreover, the kerry drive device and the guide device can be easily aligned with each other, and the kerry bar can be smoothly inserted into both devices. Further, according to the second aspect, when the key grooves of the kelly drive device and the guide device do not match, the key of the round kelly bar is received by the receiving plate, and damage to the guide roller and the like can be prevented.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an earth drill of the present invention,

FIG. 2 is an enlarged front view seen from the line AA in FIG.

3 is a cross-sectional plan view taken along line BB of FIG.

FIG. 4 is an enlarged plan view of a CC cross section of FIG.

FIG. 5 is a diagram showing a state where the Kelly drive device is lifted from the state of FIG. 2;

6 is an enlarged perspective view showing a state in which the positioning pointer of the Kelly drive device and the positioning pointer of the guide device in FIG.

FIG. 7 is an enlarged sectional front view showing a state where the lower end of the key of the round kelly bar is received by the receiving plate of the guide device according to the present invention.

[Explanation of symbols]

 4 Round Kerry bar 4a Key 5 Front frame 6 Upper frame 7 Kelly drive device 7b Key groove 12 Guide pin 13 Positioning pointer 14 Guide device 14a Key groove 15 Lower plate 16 Rotational force transmission piece 17 Upper plate 18 Guide roller 20 Positioning pointer 21 pin hole 22 receiving plate

Claims (2)

[Claims] 1. An earth drill main body, a front frame supported by the earth drill main body so as to be capable of undulating, a kelly drive device mounted on the front frame via a thrust cylinder, and rotatably attached to the kelly drive device. , Kelly bar inserted so that it can move in the axial direction,
In an earth drill having an excavation bucket attached to the lower end of the kelly bar, a guide device for receiving the kerry bar is provided on the front frame, and the kerry bar is configured to be supported at two upper and lower positions of the kerry drive device and the guide device. A guide pin and a positioning pointer are attached to the lower portion of the kelly drive device, and the guide pin is in phase with the guide pin when the positioning pointer that matches the positioning pointer of the kelly drive device and both positioning pointers match each other. Earth drill with a hole for inserting a guide pin. 2. An earth drill main body, a front frame supported by the earth drill main body so as to be capable of undulating, a kelly drive device mounted on the front frame via a thrust cylinder, and rotatably attached to the kelly drive device. In a ground drill having a keyed round kelly bar inserted movably in the axial direction and an excavation bucket attached to the lower end of the keyed round kerry bar, a guide device for receiving the round kerry bar is provided in the front frame, and the round kelly bar is provided. Is configured to be supported at two upper and lower positions of the kelly drive device and the guide device, and a guide pin and a positioning pointer are attached to the lower part of the kelly drive device,
The guide device is provided with a positioning pointer for matching the positioning pointer of the Kelly drive device, and a guide pin insertion hole that is in phase with the guide pin when both positioning pointers are in the matched state. Is
An earth drill comprising a receiving plate that receives a lower end of a key of a kerry bar in a state where the key grooves of the kerry drive device and the guide device do not match.