JPH0426554Y2 - - Google Patents

Description

[Detailed description of the invention] (3-1) Field of application of the invention The invention relates to a telescopic type kelly bar with a square pipe structure.

(3-2) Conventional technology The Earth Drill's Kelly bar is a telescopic type consisting of 3 to 4 stages of square pipes, so in order to smoothly expand and contract the Kelly bar of each stage, it is necessary to A gap must be provided. In addition, the earth drill involves an operation in which the excavator is rotated to a position away from the excavation hole to discharge the earth and sand taken into the bucket. As a result, each kelly bar is shaken in the horizontal direction, so that each kelly bar moves by the amount of the gap between it and each kelly bar, and an impact sound is generated between the kelly bars.

(3-3) Problems to be solved by the invention This impact sound resonated due to the square pipe structure of the Kerryva, resulting in a very harsh sound. In addition, since the kelly bar has the important function of transmitting rotational torque to the excavation bucket, increasing the gap will cause each kelly bar to disengage, and the dimensions of the kelly bar drive device are determined by the size of the outermost kelly bar. In order to make it as compact as possible, the gap must be made small, and there is no space to install a shock absorber, and since the tangential force is extremely large when transmitting rotational torque, it is transmitted through a shock absorber. There was a problem that it was difficult to install the cushioning material because it was impossible to do so.

An object of the present invention is to provide a kelly bar that does not impede the transmission of rotational torque and can reduce the sound generated by the shaking of the telescopic kelly bar.

(3-4) Means for Solving the Problems In order to achieve the above object, the present invention has a multi-stage telescopic kelly bar with a square pipe structure. A feature is that a cushioning material made of resin such as urethane is attached almost to the central inner surface.

(3-5) Embodiment An embodiment of the present invention will be described in more detail below with reference to FIGS. 1 to 5.

FIG. 5 shows an overall side view of an earth drill commonly used as a vertical hole drilling machine. The earth drill takes earth and sand into the bucket,
Since a vertical hole is excavated by repeatedly lifting it to the ground and discharging it, in order to facilitate this repetitive work, a method is adopted in which the bucket 3 is supported by a wire rope 2 with a crane 1, as shown in Fig. 5. It is taken. The bucket 3 is attached to the lower end of the Kelly bar 4, and the Kelly bar 4 is held movably up and down by a Kelly bar drive device 6 installed on the front frame 5, and the upper end is connected to the wire rope 2 via a swivel joint 7. The Kerry bar 4 and the bucket 3 as an excavator are connected to each other so that they can rotate. Also wire rope 2
is hung on a sheave 9 at the upper end of the boom 8, and is extended and retracted by a winch 10, thereby raising and lowering the bucket 3.

Also, as shown in Figure 1, Kerryba 4 is usually 3
The steps are retractable, and the outer tier is 11.
They are constructed of square pipe structures called a second kelly bar 12 and an inner kelly bar 13. When Kerryba 4 is in its most contracted state, Outer Kerryba 11
The second keel lever 12 is supported by the flange portion 13a of the inner keel lever 13 via a seat plate 14 and a spring 15. The lower end of the inner keel lever 13 is connected to the keel lever insertion portion 3a on the upper part of the bucket 3 with a pin 16. The upper end of the inner lever 13 is connected to the wire rope 2 via a swivel joint 7 with pins 20 and 21.

In addition, as shown in FIGS. 2 to 4, in order to fill the gap between the inner kelly lever 13 and the second kelly lever 12, a resin such as urethane is placed above the second kelly lever 12 and on the inner surface of the center of the four sides. A cushioning material 22 is provided. This cushioning material 22 has a brim, so the second Kellyba 1
Don't fall into the trap of 2. Further, a screw seat 12b is fixedly attached to the second kelly lever 12, and a plate 23 is attached thereto with bolts 24 to prevent the cushioning material 22 from falling off. Similarly, in order to fill the gap between the second kelly lever 12 and the outer kelly lever 11, a cushioning material 25 made of a resin such as urethane is provided above the outer kelly lever 11 and on the inner surface at approximately the center of the four sides so as to protrude from the inner surface. ing. This buffer material 2
5 also has a collar, so it will not fall inside the outer rib 11. Further, since a screw hole is cut in the outer keel lever 11, the plate 26 is attached thereto with bolts 27 to prevent the cushioning material 25 from falling off.

Next, the effect will be explained. When the wire rope 2 is let out, each kelly bar descends downward while being overlapped with the other as shown in FIG. And Bucket 3 touches down. As shown in FIG. 4, the Kelly bar 4 passes through the square hole 6a of the Kelly bar drive device 6.
Because of the three-stage conformal pipe structure, the rotational driving force from the Kelly bar drive device 6 is transmitted to the bucket 3 while the three Kelly bar stages mesh with each other. That is, the Kelly bar drive device 6 is rotated clockwise. Then square hole 6
The rotational force is transmitted to each corner portion of the outer kelly lever 11 via the outer kelly lever 11, and is further transmitted from the outer kelly lever 11 to each corner portion of the reinforcing member 12c wound above the second kelly lever 12. The signal is then transmitted from the second kelly lever 12 to each corner portion of the inner kelly lever 13. Here, regarding the cushioning material 22 of the cushioning materials 22 and 25, since it is located almost in the center of the second kelly bar 12 and is made of a soft resin such as urethane, it will not be affected even if the second kelly bar 12 and the inner kelly bar 13 engage with each other. do not have. In addition, the bolt 24 is provided with the reinforcing member 12c so as not to contact the outer keel lever 11 in the above-mentioned engaged state.
Since it is located inside of the outer surface, it will not be damaged. The same applies to the buffer material 25.

As the excavation progresses further, the wire rope 2 is let out, and finally the upper flange 11a of the outer kelly bar 11 comes into contact with the upper surface of the square hole portion of the kelly bar drive device 6 and is supported. When digging deeper,
The wire rope 2 is let out, and the second kelly lever 12, the inner kelly lever 13, and the swivel joint 7 descend together, and finally the upper projection 12a of the second kelly lever 12 comes into contact with the lower projection 11b of the outer kelly lever 11 and is supported. .
When excavating deeper, the wire rope 2 is let out, and the inner kelly lever 13 and swivel joint 7 are integrated into the second kelly bar 12.
descend inside. At this time, the buffer materials 25 and 22 are the second kelly bar 12 and the inner kelly bar 1, respectively.
3. It will rub against the surface, but since it is made of urethane material that is resistant to wear, it will not cause any problems.

Further, in order to discharge the earth and sand taken into the bucket 3 to the ground, the Kelly bar 4 is folded short as shown in FIG. 1, and the crane 1 is rotated. At this time, the Kelly bar 4 swings in the horizontal direction due to inertial force. Here, outer kelly bar 11, second kelly bar 1
2. The lower end of the inner keel lever 13 includes the seat plate 14, the spring 15, and the flange portion 1 of the inner keel lever 13.
Since it is in contact via 3a, there is little contact noise from this point. In addition, since buffer materials 22 and 25 are installed above each Kelly bar,
This absorbs contact sound, resulting in less sound generation.

Although urethane is used as an example of the cushioning material, a nylon material containing molybdenum disulfide, which absorbs sound generation and is resistant to abrasion, may also be used.

Further, an example has been described in which the cushioning materials 22 and 25 are attached above each Kelly bar, but it goes without saying that the effect will be enhanced if they are attached further below.

(3-6) Effects of the invention As described above, according to the invention, a cushioning material made of resin such as urethane is attached to the upper part of the adjacent outer kelly bar and on the inner surface of approximately the center of one side. Therefore, it does not interfere with the transmission of rotational torque, suppresses the generation of contact noise due to shaking during soil removal by bucket, and has the effect of reducing noise during soil removal by the earth drill.

[Brief explanation of the drawing]

Figure 1 is an enlarged longitudinal cross-sectional view taken along the - line in Figure 5, Figure 2 is an enlarged cross-sectional view taken along the - line in Figure 1, and Figure 3 is an enlarged cross-sectional view taken along the - line in Figure 1. , FIG. 4 is a cross-sectional explanatory view showing a state in which rotational force is transmitted to the Kelly bar by the Kelly bar drive device in FIG. 2, and FIG. 5 is an overall side view of the earth drill.

Claims (1)

[Scope of utility model registration request] A multi-stage telescopic kelly bar with a square pipe structure, characterized in that an impact material made of a resin such as urethane is attached to the upper part of the adjacent outer kelly bar and on the inner surface of approximately the center of one side.