JPS6231503Y2 - - Google Patents

Description

[Detailed description of the invention] This invention has been awarded as a noiseless and vibrationless construction method. Regarding the enlarged auger head used in the so-called medium excavation method, it is especially suitable for this kind of concrete pile, which has a wall thickness of 600 mm in outer diameter and 350 mm in inner diameter, where the inner diameter is approximately 1/2 of the outer diameter. Concerning the optimum expansion auger head.

Using an auger head with an expansion/contraction bit that is large enough to pass through the hollow interior of this type of pile, the lower part of the concrete pile can be excavated efficiently, but since this type of pile is thick, the expansion/contraction bit etc. become a hindrance. Due to insufficient removal of earth and sand in the excavated area, concrete piles cannot be placed efficiently, and if the removal of earth and sand does not progress, a lump of earth and sand will form at the bottom of the concrete pile, making it impossible to remove the excavated earth and sand. The worst was about to happen. Particularly in areas with low moisture soil, the above-mentioned lumps often form, and an improvement has been desired.

In view of the above, the object of the present invention is to provide an enlarged auger head suitable for this type of thick-walled pipe.

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

Reference numeral 1 denotes a cylindrical main body having a hollow portion 2, and the cylindrical main body 1 is configured such that substantially the lower half thereof presents a half-cut portion 1a, and a spout opening communicating with the hollow portion 2 that can be freely opened and closed. In this embodiment, a spout 3a is provided on the circumferential surface side of the lower end of the half-cut portion 1a, and a spout 3 is provided on the lower end of the cylindrical portion 1b on a side that substantially corresponds to the spout 3a. It is being Air, cement milk, mortar, etc., which are press-fitted into the hollow part of the screw auger, are injected from the spout ports 3 and 3a through the hollow part 2. Reference numerals 4 and 4a denote a pair of spiral blades wrapped around the outer peripheral surface of the main body 1, one of which, the spiral blade 4, is provided so as to straddle the half-cut portion 1a of the main body 1, thereby making it possible to connect the flat surface of the half-cut portion 1a with the spiral. A gap A is formed between the wing 4 and the bottom surface. Further, its tip protrudes from the main body 1, and a downward claw 5 is attached to its tip edge. The tip of the other spiral blade 4a is located on the flat surface of the half-cut portion 1a, and is flush with the flat surface, and a downward claw 5a is attached to the tip edge. Reference numeral 6 denotes a wedge-shaped expansion/contraction bit, which is pivotally supported by a bracket 7 protruding from the upper end portion of the half-cut portion 1a of the main body 1, the base of which is inserted into the gap A, and extends along the flat surface of the half-cut portion 1a. It is configured to expand and contract. In the expanded state shown in FIG. 2, the tip of the helical wing 4a is located outward from the other helical wing 4a, and when the helical wing 4 is reversed in the direction of the arrow (counterclockwise) in this state, one of the helical wings 4 reaches the stopper. If the expansion/contraction bit 6 fails to contract in diameter, the stopper function of one of the spiral wings 4 is used to correct or break the pin 8. In addition, in the diameter-reduced state shown in FIG. 1, its tip end is located within the cutting edge of the other spiral blade 4a, and in this state it moves up and down inside the hollow of the concrete pile. The expansion/contraction bit 6 expands due to earth and sand resistance, and its diameter is reduced by pulling up the auger head. In the figure, numerals 9 and 10 are claws of the expansion/contraction bit 6.

As described in detail above, the present invention has a configuration in which a half-cut portion is provided in a cylindrical body having a pair of spiral wings on the outer peripheral surface, and an expansion/contraction bit movably supported on the half-cut portion is provided. This is an auger head that is most suitable for piles with medium thickness.The space between the inner diameter of the concrete pile and the auger head is large, making it easy to remove the excavated soil, as well as being noiseless and vibration-free. Moreover, it has the effect of being able to drive efficiently, shortening the construction period and significantly reducing costs. In addition, since there is only one expansion/contraction bit, it is easy to simplify the mechanism and expand/contract the bit, and one of the spiral wings also functions as a stopper, which not only simplifies the mechanism, but also makes it easy to expand and contract the bit.
The practical effects of the present invention are great, such as making it possible to straighten and break the pin, reduce the diameter of the expansion/contraction bit, and make it easier to pull out the auger head.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention,
Fig. 1 is a front view showing the expansion/retraction bit in its reduced diameter state, Fig. 2 is a front view showing the expansion bit in its expanded state, and Fig. 3 is a front view showing the enlargement bit in its expanded state.
FIG. 1...Main body, 1a...Half-cut part, 1b...Cylindrical part, 2...Cavity part, 3, 3a...Ejection port, 4, 4
a... Spiral wing, 5, 5a... Claw, 6... Expansion bit, 7... Bracket, 8... Pin, 9, 10...
...claw, A... void.

Claims (1)

[Scope of utility model registration request] A cylindrical main body having a half-cut portion on the lower side is provided with a hollow portion and a plurality of jet ports communicating with the hollow portion, and a pair of helical blades are provided to wrap around the outer peripheral surface of the main body, and one of the spiral blades is provided. An enlarged auger head for use in a medium excavation method, characterized in that the auger head is configured to straddle an enlarged/reduced bit movably pivoted on the half-cut portion of the main body.