JPH0758030B2 - Auger for drilling pile holes - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an auger for excavating a pile hole provided with one or two expansion / contraction excavating blades.

(Prior Art) Conventionally, various ideas have been known for enlarging and reducing the drilling blade of an auger. Most of them have a structure in which the arm rod attached to the auger shaft is enlarged or reduced by utilizing the rotational force.

(Problems to be Solved by the Invention) The conventionally known expandable / reducible drilling blade is expanded by rotation in one direction and is contracted by rotation in the other direction. However, since it expands and contracts due to the friction of the excavating blade during rotation, there is a problem that it cannot be sufficiently expanded or sufficiently reduced when the enlarging / reducing force is larger than the friction of the excavating blade for some reason. In addition, since the above-mentioned enlargement / reduction occurs when the lateral blade piece comes into contact with the hole wall, this method has a problem in that it is not efficient to enlarge / reduce the drilling blade at the bottom end.

(Means for Solving the Problem) However, according to the present invention, since the digging blades that can be enlarged and reduced are provided in the upper and lower two steps on the shaft rod, it is possible to dig holes to be enlarged to have the same diameter in the vertical direction. It is the one. Also, since the base of the arm rod is rotatably attached to the lower part of the shaft rod by the horizontal axis, it is usually reduced by lifting the auger and enlarged by pressing the auger against the bottom of the hole. Is solved.

That is, the present invention provides a through hole in the central portion, installs a spiral blade on the lower outer wall of the shaft rod provided with a connection portion on the upper portion, in an auger provided with a fixed cutting edge in the central portion of the lower end of the spiral blade,
In the lower part of the shaft rod, a lower excavation blade that can be enlarged and reduced is provided under the spiral blade, and in the outer wall of the shaft rod, an upper excavation blade that can be enlarged and reduced is provided on the upper side of the spiral blade. The blade is attached to the shaft rod so that the bases of two upper arm rods each having a blade piece at the tip are rotatably attached by a vertical axis, and the lower excavating blade is one of two lower arm rods having a blade piece at the tip. The base is rotatably attached to the recessed wall of the shaft rod by a horizontal shaft, and the recessed wall is provided with a stopper for restricting the rotation of the lower arm rod, and the recessed wall is provided with the stopper. This is an auger for excavating a pile hole, characterized in that a nozzle communicating with the through hole is opened. Also, for the lower arm rod, for the excavation of pile holes, the position where the blade piece is on the outer circumference of the maximum excavation diameter is set as the expansion limit, the cutting edge enters the maximum diameter of the auger fixing part, and the position where the lower arm rod is inclined outward is the reduction limit. It is an auger.

According to the above, when it does not shrink due to its own weight, an external force is applied on the outer end of the arm rod to assist the shrinkage, and when the arm mounting portion is clogged with soil or the like, pressurized air is blown out from the nozzle, The soil or the like is blown off so as not to hinder the expansion and contraction of the arm rod.

(Operation) In the present invention, since the excavating blades that are scaled up and down are installed on the outside of the shaft rod, the head portion of the pile hole can be excavated in the same diameter in the vertical direction.

Also, since the arm rod is rotatably attached to the lower part of the shaft rod via the horizontal shaft, if the shaft rod is lifted, it will be reduced by the weight of the excavating blade, and if the excavating blade is pressed against the bottom of the pile hole, the expansion limit will increase. Can be expanded to.

Further, if pressurized air or the like is blown out from the nozzle, even if soil, gravel, or the like is clogged, it can be blown off and there is no hindrance to the rotation of the arm rod.

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

A through hole 2 is bored in the central portion of the shaft rod 1, a connecting portion 3 is provided outside the upper portion of the shaft rod 1, and upper and lower excavating blades 4 and 5 that can be expanded and contracted in the middle portion and the lower end portion of the shaft rod 1. Are provided in upper and lower two stages. The upper excavating blade 4 is provided with brackets 6 and 6a protruding from the outer wall of the shaft rod 1.
In addition, the base ends of the arm rods 7 and 7a are rotatably attached by the vertical axes 8 and 8a, and the blade pieces 9 and 9a are fixed to the tips of the arm rods 7 and 7a. Since the diameters are symmetrically provided, when the upper digging blade 4 is expanded, it is expanded substantially in diameter. Next, in the lower excavating blade 5, fixed blade pieces 11a, 11b, 11c, 11d are provided at the center of the lower portion of the shaft rod 1 so as to project downward while changing the distance to one set in the radial direction and the arm rod. The bases of 12 and 12a are rotatably attached by a horizontal shaft 13, and the arm rods 12 and 12
Blade pieces 14, 14a are provided downward to the tip of a. The bases of the arm rods 12 and 12a are fitted in the recesses (recessed walls) 15 of the shaft rod 1, and the walls 15a and 15b of the recesses 15 are stoppers for limiting rotation above or below the arm rods 12 and 12a. 10 (for example, the opening is limited so that the blade pieces 14 and 14a are kept substantially vertical when the arm rods 12 and 12a are enlarged). The recess 15
Further, nozzles 18 and 18a for blowing pressurized air are opened.

On the shaft rod 1a between the upper drilling blade 4 and the lower drilling blade 5,
Spiral blades 17 are circumferentially installed.

In the above-mentioned embodiment, for example, if the auger rod 16 is rotated forward and the upper excavating blade 4 is contracted, the auger rod 16 is normally rotated to excavate the pile hole 19 in the enlarged diameter of the lower excavating blade 5 to a predetermined depth. Reaches the maximum. Next, the auger rod 16 is reversely rotated to excavate the expanded bottom portion 20. By the lower excavation blade 5 in the above, the pile hole bottom 21 can be excavated in a substantially flat shape.

Further, in the method of excavating the hollow pile by sinking it (for example, the medium excavation method), the auger can be extracted from the central hole of the hollow pile even when the expanded bottom portion is dug as in this embodiment.

(Effect of the invention) According to the present invention, since the excavating blades that can be scaled up and down are installed above and below the spiral blade of the shaft rod, respectively, it is possible to excavate a pile hole having a predetermined diameter and a pile hole having an expanded bottom portion with one auger, This has the effect of enabling flat excavation of the bottom of the pile and facilitating excavation of the expanded bottom. Further, since the lower excavating blade expands due to pressure, there is an effect that the maximum diameter can be always maintained.

Further, since the central hole of the shaft rod and the nozzle of the arm rod mounting base of the lower excavating blade are communicated with each other, even if soil is clogged between the recessed wall having the stopper and the arm rod, it can be easily removed. There is also. Therefore, there is no possibility that soil will be clogged between the stopper and the arm rod, so that the arm rod can be opened securely and the pile hole can be excavated with high accuracy, and the arm rod can be securely closed to easily insert the auger from the pile hole. There is an effect that can be raised.

In addition, when the hollow pile is settled and used for excavation, the auger can be easily and surely pulled out from the central hole of the hollow pile after excavating the bottom expansion part, which improves the efficiency of construction using this method. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is an enlarged front view of a drilling blade according to an embodiment of the present invention,
FIG. 2 is a similarly reduced front view, FIG. 3 is a side view of the same reduced state, and FIG. 4 is a sectional view of the same used state. DESCRIPTION OF SYMBOLS 1 ... Shaft rods 4, 5 ... Upper and lower excavation blades 7, 7a ... Arm rods, 8, 8a ... Vertical axis 9, 9a ... Blade pieces 10, 10a ... Stoppers 11a, 11b, 11c, 11d ... Fixed blade pieces 12 , 12a ... Arm rod, 13 ... Horizontal axis 14, 14a ... Blade piece, 17 ... Spiral blade 18, 18a ... Nozzle

Claims (2)

[Claims] 1. An auger in which a through hole is provided in a central portion and a spiral blade is provided on a lower outer wall of a shaft rod having a connecting portion at an upper portion thereof, and a fixed blade is provided at a central portion of a lower end of the spiral blade. A lower excavating blade that can be enlarged and reduced is provided below the spiral rod at the lower part of the rod, and an upper excavable blade that can be enlarged and reduced is provided at the outer wall of the axial rod above the spiral blade. Is a rotatably attached base of two upper arm rods having blade pieces at the tip to the shaft rod, and the lower excavating blade is a base portion of two lower arm rods having blade pieces at the tip. Is rotatably attached to the recessed wall of the shaft rod by a horizontal shaft, and the recessed wall is provided with a stopper for restricting the rotation of the lower arm rod, and the recessed wall has the transparent member. Auger for pile hole excavation characterized by opening a nozzle communicating with the hole 2. In the lower arm rod, the position where the blade piece becomes the outer diameter of the maximum excavation is set as the expansion limit, and the position where the blade piece enters the maximum diameter of the auger fixing portion and the position where the lower arm rod is inclined outward is set as the reduction limit. An auger for excavating a pile hole according to claim 1.