JPH057354Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a telescopic kelly bar with a rectangular tube structure used in an earth drill.

[Conventional technology]

The earth drill's telescopic type Kerryba is
In general, three-stage metal outer ribs are slidably fitted onto a metal inner ribber.
It has a tiered or four-tiered telescoping rectangular tube structure, and a pit is excavated deep into the ground using an excavation bucket attached to the lower end of the inner keel. When unloading soil during excavation work, the kelly bars are retracted, the excavation bucket is pulled up to the ground, and the crane body is rotated to remove the soil.
Since there is a pause, the Kerry bars come into contact with each other and make a loud impact sound.

For this reason, Utility Model Application No. 62-133788 and Utility Model Application No. 62-
Kerryba as disclosed in Publication No. 154090 has been proposed.

As shown in FIG. 5, this kelly lever includes an inner kelly lever 21 and a two-stage outer kelly lever, that is, a second kelly lever 22 adjacent to the inner kelly lever 21 and serving as an outer kelly lever;
A three-stage kelly lever 24 has an outer kelly lever 23 slidably fitted on the outside of each kelly lever 24, and a kelly rope 26 is connected to the upper end of the inner kelly lever 21 via a swivel joint 25 having a circular cross section. Kellyba 24 by rope 26
An excavation bucket 27 is attached to the lower end of the inner lever 21.

On the outside of the upper part of the second kelly lever 22, when the kelly lever 24 is extended, the second kelly lever 22 is connected to the outer kelly lever 22 due to the gap between each kelly lever.
3, a reinforcing member 28 is provided, and an inner kelly lever 21 and a reinforcing member 28 are provided at the inner center of each side of the second kelly lever 22 slightly below the mounting position of the reinforcing member 28. A cushioning material 29 made of resin is provided in a protruding manner to reduce noise caused by contact with the second key lever 22. moreover,
A cushioning material 30 made of resin is protruded from approximately the center of the inner side of each side slightly below the top of the outer kelly lever 23 to reduce noise caused by contact between the second kelly lever 22 and the outer kelly lever 23.
In the most contracted state, the cushioning material 30 is in slidable contact with the reinforcing member 28.

When the kelly bar 24 is in the most reduced state, the second kelly bar 22 and the outer kelly bar 23 are
is supported by a flange 33 of the inner lever 21 via a seat plate 31 and a spring 32 for shock absorption.

In addition, when Kerryba 24 is in its most extended state,
The flange 23a formed on the outer side of the upper part of the outer kelly lever 23 comes into contact with the upper surface of the kelly lever rotation drive device, and the swivel joint 25 comes into contact with the stopper step 22b formed on the inner side of the lower part of the second kelly lever 22.
The stopper projection 22a provided on the outer side of the intermediate portion of the second key lever 22 comes into contact with the stopper step 23b formed inside the lower part of the outer key lever 23.

[The problem that the idea aims to solve]

Therefore, in the Kelly lever 24 having the above structure, the swivel joint 25 is formed so as to be able to come into contact with the retaining step portion 22b of the second Kelly lever 22 when expanding and contracting. When the swivel joint 25 moves up and down inside the second key lever 22 during expansion and contraction, the cushioning material 29 of the second key lever 22
There is a risk that the cushioning material 29 will be worn out and lose its function.

In addition, if the amount of protrusion of the cushioning material 29 is reduced in order to avoid sliding contact between the cushioning material 29 and the swivel joint 25, the cushioning material 29 will disappear more quickly due to wear and will soon lose its function as a cushioning material. As a result of collisions between the parts, they wear out quickly, resulting in poor durability, and the problem of noise generation remains unsolved.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly durable earth drill, Kerryba, in which the cushioning material is arranged so as not to interfere with the swivel joint, and the function of the cushioning material is not impaired for a long period of time.

[Means to solve the problem]

In order to achieve the above object, the present invention has a rectangular cylindrical structure in which a plurality of outer kelly levers are slidably fitted onto an inner kelly lever, and a cushioning material made of resin such as nylon is provided between each kelly lever. In a keel of an earth drill in which a swivel joint connected to the upper end moves up and down into an outer keel that is adjacent to the inner keel, a buffer material provided between the inner keel and an outer keel that is adjacent to the inner keel is attached to the top of the outer keel that is adjacent to the inner keel. It is characterized by being fixed at the inner corner.

[Effect]

Therefore, there is a sufficient gap between the swivel joint and the cushioning material at the upper inner corner of the outer kelly lever adjacent to the inner kelly lever so that the swivel joint is not interfered with by the cushioning material when the swivel joint is raised or lowered. In both cases, it is possible to prevent the inner keel lever from coming into contact with the cushioning material and generating large impact noises during earth removal during excavation work.

〔Example〕

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

The earth drill 1 is provided with a front frame 5 on which a Kellyba rotation drive device 4 is mounted at the bottom of a boom 3 that is vertically installed on the front part of a crane body 2, and a square hole of the Kellyba rotation drive device 4 ( The Kelly bar 6 inserted into the crane (not shown) is suspended from the top of the boom 3 by a Kelly rope 8 via a swivel joint 7 having a circular cross section, and is suspended from the top of the boom 3 by a Kelly rope 8.
It is possible to move up and down by winding up and rewinding a winch 9 provided at the door.

This kelly lever 6 is configured to be extendable and retractable with four steps of rectangular tubes including a second kelly lever 11, a third kelly lever 12, and an outer kelly lever 13 which are slidably fitted onto the inner kelly lever 10 as an outer kelly lever. is connected to a swivel joint 7, and an excavation bucket 14 is attached to the lower end.

At the four corners of the upper inner side of the second key lever 11, cushioning materials 15 made of nylon resin are fixed by rivets 16, respectively.

Therefore, since the buffer material 15 is fixed at the four corners, when the swivel joint 7 moves up and down within the second key lever 11, the swivel joint 7 is moved between the swivel joint 7 and the buffer material 15. Since there is a sufficient period of time during which the buffer material 15 does not interfere with the swivel joint 7, even if the swivel joint 7 contacts the inner surface of each side of the second key lever 11, the swivel joint 7 does not come into contact with the swivel joint 7. As a result, the cushioning material 15 is not worn out or damaged, and the durability of the cushioning material 15 is improved.

In addition, during soil removal during excavation work, the corners of the inner keley lever 10 come into contact with the buffer material 15 and are buffered, so that the inner kelly lever 10 is connected to the second kelly lever 11.
Since it does not directly hit the inner surface of the housing, impact noise can be suppressed to a low level.

Furthermore, as shown in FIGS. 1 and 3, the cushioning material 15 is sufficiently thick, and the contact surface 15a with the inner lever 10 is formed into a tapered surface that becomes thinner from the top to the bottom. Therefore, even if the inner keel lever 10 is bent at the connecting portion between the swivel joint 7 and the inner keel lever 10 and the upper edge corner of the inner keel lever 10 comes into contact with the cushioning material 15, Since it slides on the contact surface 15a of the cushioning material 15, the cushioning material 15 is not damaged.

Further, at approximately the center of the upper outer surface of each side of the outer kelly levers other than the outermost kelly lever 13, that is, the second kelly lever 11 and the third kelly lever 12, a cushioning material made of nylon resin similar to the cushioning material 15 is provided. 17 are fixed by rivets 16, respectively.

The buffer material 17 is fixed so as to form a space between it and the inner surface of the Kelly bar that faces it, and when the Kelly bar 6 is driven to rotate, the buffer material 17 is attached to the inner surface of the Kelly bar that faces it. The thickness and width are such that they do not come into contact with each other.

Therefore, this cushioning material 17 is fixed at the approximate center of the outer surface of each side of each Kelly bar so as to face the inner surface of each side of each Kelly bar where stopper protrusions etc. are not provided. When expanding and contracting, each of the cushioning materials 17 slides against the smooth inner surface of the outer Kerry bar, and since there are no protrusions that can become an obstacle, there is no interference with other members, and the resulting cushioning Abrasion and damage to the material 17 are prevented, and durability is improved.

In addition, even if the crane body 2 is rotated to move the Kelly bar 6 in the horizontal direction after the Kelly bar 6 is retracted during soil removal, the impact when the Kelly bar 6 hits each other is absorbed by the cushioning materials 15 and 17. Can reduce sound.

[Effect of idea]

As described above, in the present invention, a cushioning material made of resin such as nylon is fixed to the upper inner corner of the outer kelly lever adjacent to the inner kelly lever of the telescopic kelly lever, so that the inner kelly lever comes into contact with the cushioning material during earth removal. This not only reduces the impact noise caused by contact between the inner kelly bar and the adjacent outer kelly bar, but also prevents the swivel joint that suspends the kelly bar from sliding against the cushioning material when the kelly bar expands and contracts. In addition to smooth expansion and contraction, the cushioning material is prevented from being worn out or damaged, and the durability of the cushioning material is improved.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a cross-sectional view of Kerryba, FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a cross-sectional view of FIG. 1. 4 is a front view of the earth drill, and FIG. 5 is a longitudinal sectional view showing an example of a conventional Kerry bar. 1...Earth Drill, 6...Keriba, 10...
...Innakereba, 11...Secondkereba,
12...Third kelly bar, 13...Outer kelly bar, 15, 17...Buffer material.

Claims (1)

[Scope of utility model registration request] It has a rectangular tube structure in which a plurality of outer kelly levers are slidably fitted onto the inner kelly lever, and a cushioning material made of resin such as nylon is provided between each kelly lever, and a swivel joint is connected to the upper end of the inner kelly lever. , in a keel of an earth drill that moves up and down in an outer keel that is adjacent to an inner keel, a buffer provided between the inner keel and an outer keel that is adjacent to the inner keel is fixed to the upper inner corner of the outer keel that is adjacent to the inner keel. Kerryba is a featured earth drill.