JPH0355387A - Auger for excavation of pile hole - Google Patents

Abstract

PURPOSE:To make excavation in the bottom of a pile hole executed easily and to make the bottom nearly flat by providing excavating bits on the external wall of a shaft rod to which a through hole and a connecting part are provided respectively on its middle and upper parts, and also by providing two-staged, expandable excavating bits to the lower part of the shaft rod. CONSTITUTION:A through hole 2 is drilled in the center of a shaft rod 1 and a connecting part 3 is provided on the outer upper side of the shaft rod 1. In the middle and lower parts of the shaft rod 1, expandable upper and lower bits 4 and 5 are provided in two stages. The upper bits 4 are so installed that they are supported with arms 7 and 7a that are rotatably hinged to vertical shafts 8 and 8a at their base ends. The bits 5 are formed in such that each one pair of fixed bid edges 11a-11d are installed protruding 1 downward in different radius, and the bits 5 are fixed with a horizontal shaft 13 so that the bits can make rotary motion. In normal rotation of an auger rod 16, a pile hole is excavated with the expanded lower bits 5, and in reverse rotation, an expanded hole bottom is excavated therewith afterward. Thereby the pile hole can be excavated with its bottom made nearly flat and kept always in maximum diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an auger for excavating pile holes equipped with one or two enlarged/reduced excavating blades.

(Prior Art) Conventionally, various ideas for enlarging and reducing the digging blade of an auger are known. Most of them utilize rotational force to expand or contract an arm rod attached to an auger shaft.

(Problems to be Solved by the Invention) Conventionally known excavating blades that can be expanded and contracted expand by rotating in one direction and contract by rotating in the other direction. However, since it expands and contracts due to the friction of the drilling blade when rotating,
If the enlarging/reducing force is greater than the friction of the excavating blade for some reason, there is a problem in that it cannot be sufficiently enlarged or reduced sufficiently. Further, in the above method, the cutting blade in the horizontal direction is enlarged or reduced when it comes into contact with the hole wall, so this method has a problem in that it is not efficient in enlarging or reducing the cutting blade at the lowest end.

(Means for Solving the Problems) However, in this invention, the drilling blades that can be enlarged and reduced are provided on the shaft rod in two stages, upper and lower, so that the hole to be enlarged and excavated can be excavated with the same diameter in the upper and lower sides. This is what I did. In addition, since the base of the arm rod is rotatably attached to the lower part of the shaft rod by means of a horizontal axis, the auger is normally reduced by lifting it, and expanded by pressing the auger against the bottom of the hole, thereby solving the problems of the conventional method. This solved the problem.

That is, one of the inventions is an auger in which a drilling blade is provided on the outer wall of a shaft rod that has a through hole in the center and a connecting portion at the top, and the shaft rod has a drilling blade that can be enlarged and contracted. This is an auger for drilling pile holes, which is characterized by having two stages, upper and lower.

Another one is an auger in which a drilling blade is provided on the outer wall of a shaft rod with a through hole in the center and a connection part in the upper part, and a drilling blade that can be expanded and contracted is provided in the lower part of the shaft rod, This auger for drilling pile holes is characterized by a spiral blade installed on its upper outer wall.

Still another one is an auger in which a drilling blade is provided on the outer wall of a shaft rod that has a through hole in the center and a connecting portion at the top, and a drilling blade that can be expanded and contracted is provided at the bottom of the shaft rod. This is an auger for drilling pile holes.

In addition, the excavation blade has a fixed blade protruding from the center, and
The bases of two arm rods are rotatably attached to the shaft rod by horizontal shafts, and a blade piece is provided at the tip of the arm rod, and the arm rod has an expansion limit at a position where the blade piece becomes the outer circumference of the maximum excavation diameter. The reduction limit is defined as the position where the blade piece enters the maximum diameter of the auger fixing part and the arm rod is inclined outward. Further, in the base of the arm rod, a nozzle is opened in the concave wall of the shaft serving as a stopper of the arm rod mounting portion, and communicates with a hole bored in the center of the shaft.

By doing the above, if it does not shrink due to its own weight, an external force is applied to the outer end of the arm rod to help it shrink, and if the arm attachment part is clogged with soil, pressurized air is blown out from the nozzle,
The soil, etc. is blown away so that it does not interfere with the expansion of the armrest.

(Function) In this invention, since a drilling blade that can be enlarged and reduced in two directions upward and downward is installed on the outside of the shaft rod, the enlarged head of the hole can be excavated to have equal diameters in the upper and lower sides.

In addition, the arm rod is rotatably attached to the lower part of the shaft rod via the horizontal shaft, so if you lift the shaft rod, it will shrink due to the weight of the digging blade, and if you press the digging blade against the bottom of the shaft, it will expand to its limit. It can be expanded to

Furthermore, by blowing out pressurized air or the like from the nozzle, even if dirt or gravel becomes clogged, it can be blown away and the rotation of the arm rod will not be hindered.

(Example) An example of the present invention will be described below with reference to the accompanying drawings.

A through hole 2 is bored in the center of the shaft 1, a connecting part 3 is provided on the outside of the upper part of the shaft 1, and upper and lower excavating blades 4, 5 are provided at the middle and lower ends of the shaft 1, which can be expanded and contracted. are installed in two levels, upper and lower. The upper digging blade 4 has brackets 6, 6a protruding from the outer wall of the shaft rod 1.
The base ends of arm rods 7, 7a are rotatably attached to vertical shafts 8, 8a, and blade pieces 9, 9a are fixed to the tips of arm rods 7, 7a. Since it is provided diametrically symmetrically, if the upper drilling blade 4 is expanded,
Expands approximately diametrically. Next, the lower excavating blade 5 is attached to the fixed blade pieces 11a, 1lb, llc, lid at the lower central part of the shaft rod 1.
are protruded downward at different distances from each other in the radial direction, and the bases of the arm rods 12, 12a are rotatably attached to the horizontal shaft 13, and the bases of the arm rods 12, 12a are attached downwardly to the tips of the arm rods 12, 12a. Blade pieces 14, 14a are provided at the. The arm rods 12, 12
The base of a is fitted into a recess 15 of the shaft 1, and the walls 15a, 15b of the recess 15 serve as a stopper 10 for restricting the upper or lower rotation of the arm 12, 12a (for example, the arm 12 , 12a are expanded so that the blade pieces 14, 14a are kept substantially vertical (the opening degree is limited). Nozzles 18 and 18a for blowing out pressurized air are opened in the recess 15.

A spiral blade 17 is installed around the rod 1a between the upper excavation blade 4 and the lower excavation blade 5.

In the above embodiment, for example, if the structure is such that the upper excavation blade 4 is contracted by forward rotation of the auger rod 16, the anti-hole 1 is formed in the enlarged diameter of the lower excavation blade 5 by the forward rotation of the auger rod 16.
9 to reach a predetermined depth g. Next, the auger rod 16 is rotated in the opposite direction to excavate the expanded bottom portion 20. The pile hole bottom 21 can be excavated into a substantially planar shape using the lower excavation blade 5 described above.

In addition, in a method in which the hollow pile is excavated while being lowered (for example, a hollow excavation method), the auger can be extracted from the central hole of the hollow pile even if the expanded bottom portion is dug as in this embodiment.

(Effects of the Invention) According to the present invention, the excavation blade that can be enlarged and reduced under the shaft rod or above and below is installed, so that it is possible to excavate the bottom of the shaft on a flat surface, and also to excavate the enlarged bottom part easily.4. It has the effect of Furthermore, since the lower digging blade expands under pressure, it has the effect of being able to maintain its maximum diameter at all times.

Furthermore, since the center hole of the shaft is communicated with the nozzle at the arm rod attachment base of the lower excavation blade, even if the attachment recess of the arm rod is clogged with soil, it can be easily removed.

[Brief explanation of drawings]

FIG. 1 is an enlarged front view of a digging blade according to an embodiment of the present invention;
FIG. 2 is a front view in a similarly reduced size, FIG. 3 is a side view in a reduced size, and FIG. 4 is a sectional view in a used state. 1... Axis rod 4, 5... Upper and lower digging blades 7
, 7a... Arm rod 8, 8a... Vertical axis 9, 9a.
...Blade piece 10, 10a...Stopper 11a,
llb. llc, lld...Fixed blade pieces 12, 12a.
...Arm rod 13...Horizontal shaft 14, 14a...Blade piece 1
7... Spiral blades 18, 18a... Nozzle Figure 1 Funeral 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. In an auger in which a drilling blade is provided on the outer wall of a shaft rod having a through hole in the center and a connecting portion at the top, a drilling blade that can be enlarged and contracted is provided at the bottom of the shaft rod. Auger 2 for drilling pile holes, characterized in that an auger is provided with a drilling blade on the outer wall of a shaft rod with a through hole bored in the center and a connection part provided on the upper part, the shaft rod has an enlargement/reduction function. Auger for pile hole excavation 3 characterized by having digging blades arranged in two stages, upper and lower Auger 4 for pile hole drilling, characterized in that a digging blade that can be expanded and contracted is provided at the lower part of the shaft rod, and a spiral blade is installed on the upper outer wall of the auger. The bases of the two arm rods are rotatably attached to the shaft rod by the horizontal shaft,
A blade piece is provided at the tip of the arm rod. 3. The auger for pile hole drilling according to claim 2, wherein the reduction limit is the position where the shaft is attached.
The auger for digging a pile hole according to claim 4, wherein the auger has a nozzle that communicates with a hole drilled in the center of the shaft rod.