JP2004324273A - Diameter enlarging device of auger drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily dig at enlarged diameter and easily form large diameter foot protection concrete by forming the digging blade of an auger drill digging a ground under a concrete pile through the concrete pile so that its diameter can be increased to project the tip of a high-pressure fluid injection nozzle outward from the outer diameter of the blade of the auger drill. <P>SOLUTION: A plurality of diameter increasing cutters 41 pin 43-connected to each other at the upper ends are suspended from the lower end of the tip member 10 of the auger drill. The diameter increasing cutters 41 are rotated about the pin 43 according to the normal rotation of the auger drill, projected in the diameter increasing direction and performs diameter-increased digging, and retracted according to the reverse rotation of the auger drill and returns to the suspended state. The diameter of a circle drawn by the tip of the diameter increasing cutters 41 when the cutters are projected in the diameter increasing direction is approx. 1.1 to 2.0 times that of the screw blade of the auger drill. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an auger drill diameter expanding device. More specifically, when laying concrete piles etc. in the ground, use an auger drill in the pile to expand the ground below the pile or to form a large diameter concrete bulb, It relates to a diameter expansion device.
[0002]
[Prior art]
When laying a foundation pile such as a concrete pile in the ground, it is necessary to insert an auger drill through the hollow part of the pile and to lay the pile while drilling the ground below the lower end of the pile with this auger drill. Has been done. In this case, a technique is known in which the enlarged diameter portion is formed in the ground near the lower end of the pile and below the pile, so that the concrete with a diameter larger than the outer diameter of the pile and integrated with the pile is formed in the support layer. is there. For this reason, there is an auger drill equipped with a diameter expanding device for excavating the ground below the lower end of the pile.A nozzle for injecting high-pressure air, high-pressure water, bentonite, or the like, or for injecting a hardening agent such as cement milk or the like is provided. Prepare. Such a nozzle is provided on the lower end member of the auger drill so as to project at right angles to the auger axis so as to inject the high-pressure fluid radially outward.
[0003]
Conventionally, there has been no such high-pressure fluid injection nozzle in which the tip of the nozzle protrudes outside the outer diameter of the screw blade of the auger drill.
[0004]
[Problems to be solved by the invention]
The present invention provides an auger drill inserted into a concrete pile when a concrete pile or the like is sunk in the ground, digging the ground below the lower end of the pile to easily sink the pile into the ground, and It is an object of the present invention to provide a technique for forming a magnified bulb and integrating it with the lower end of a concrete pile to dramatically increase the bearing capacity of the pile.
[0005]
More specifically, a diameter-expanding device for kneading the ground of the diameter-expanded portion is provided in the ground, and a diameter-expanding device in which a fluid ejecting device that can easily form the excavation and easily form an enlarged bulb is used. I will provide a.
[0006]
That is, as described above, in the conventional high-pressure fluid injection nozzle of the auger drill, the tip of the nozzle could not protrude outward from the outer diameter of the blade of the auger drill. In order to form concrete, we have developed a structure that protrudes the nozzle tip.
[0007]
An object of the present invention is to provide such an auger drill diameter expanding device.
[0008]
[Means for Solving the Problems]
The present invention has been made in order to solve the above problems, and is an auger drill expanding device characterized by employing the following technical means. That is, the present invention hangs a plurality of enlarged blades having upper ends pin-connected to the lower end of the tip member of the auger drill, and the enlarged blades rotate around the pins with forward rotation of the auger drill. The blades protrude in the expanding direction to perform the expanding excavation, and have a shape in which the diameter is reduced and returned to the suspended state with the reverse rotation of the auger drill, and the outer diameter when protruding in the expanding direction is the screw blade. An auger drill expanding apparatus characterized in that the diameter is 1.1 to 2.0 times the outer diameter.
[0009]
If the outer diameter when projecting in the diameter increasing direction is less than 1.1 times the outer diameter of the screw blade, the effect of the diameter expansion is small, and if it exceeds 2.0 times, the size becomes unnecessary and the torque becomes too large. Since the mechanical strength is excessively designed, it is set to 2.0 times or less.
[0010]
In the auger drill expanding device, the high pressure fluid injection nozzle attached to the side surface near the lower end of the auger drill is a double cylinder comprising a fixed outer cylinder, and a movable inner cylinder that moves forward and backward within a fixed distance within the fixed inner cylinder. The movable inner cylinder has a spout at the front end, a sealed sleeve at the rear end for inserting the front end of the high-pressure fluid supply pipe, a spring for urging the inner cylinder in a backward direction, and when the high-pressure fluid is jetted out. Preferably, the auger drill is provided with a fluid ejecting device of an auger drill having a structure in which a high-pressure fluid advances the inner cylinder against the urging force of the spring.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an auger drill expanding device of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a side view of a lower end member 10 of an auger drill according to an embodiment of the present invention, and FIG. 2 is a view taken along line AA of FIG.
[0013]
On the lower end member 10 of the auger drill, a connecting member 11, a screw blade 13 from a shaft 12, an injection nozzle 20, and drilling blades 51 and 52 are attached.
[0014]
The enlarged diameter cutting tool 41 of the present invention is suspended from a bracket 42 via a pin 43 at the lower end of the lower end member 10.
[0015]
When the auger drill rotates forward as shown in FIG. 2, the enlarged blade 41 rotates around the pin 43, and the enlarged blade 41 assumes a substantially horizontal posture, and its tip has an outer diameter 14 of the screw blade of the auger drill. Protruding more outward.
[0016]
The diameter of the circle drawn by the tip of the protruding blade 41 is set to about 1.1 to 2.0 times the outer diameter of the screw blade of the auger drill.
[0017]
3 and 4 are longitudinal sectional views of the lower end member 10 showing the fluid ejection nozzle used in the present invention. FIG. 3 shows a state where the fluid is not ejected, and FIG. 4 shows a state where the fluid is being ejected.
[0018]
In the present invention, a plurality of large-diameter blades 41 whose upper ends are connected by pins 43 are suspended from the lower end of the tip member 10 of the auger drill. The enlarged diameter blade 41 rotates around the pin 43 with the forward rotation of the auger drill. FIG. 2 shows a state in which the diameter-enlarged blade 41 protrudes in the diameter-enlargement direction by a virtual line. The diameter-increased blade 41 has a shape in which the diameter is reduced in accordance with the reverse rotation of the auger drill and returns to the suspended state as shown in FIG.
[0019]
The nozzle 20 includes a fixed outer cylinder 21 and a movable inner cylinder 30 coaxially inserted into the fixed outer cylinder 21. The fixed outer cylinder 21 is provided with a base 22 at the tip, and the movable inner cylinder 30 is provided with a flange 31 on the outer periphery of the tail end. A coil spring 23 is interposed between the base 22 and the flange 31. In the movable inner cylinder 30, the flange 31 slides on the inner peripheral surface of the fixed outer cylinder 21 in the forward / rearward direction, and the outer diameter of the movable inner cylinder 30 slides in the front end base 22 of the fixed outer cylinder 21 in the forward / backward direction. . The movable inner cylinder 30 has a piece 33 provided with a high-pressure fluid ejection hole 32 at the tip, and forms a sleeve 34 at the tail end side. The high-pressure fluid supply pipe 14 is inserted into the sleeve 34 circle.
[0020]
The space between the inner diameter of the sleeve 34 and the high-pressure fluid supply pipe 14 is sealed by a seal material 36. A ball valve 35 is provided in the movable inner cylinder 30, and the nozzle 20 is closed when not in use.
[0021]
FIG. 2 shows a state where the movable inner cylinder 30 is advanced by supplying a high-pressure fluid. The high-pressure fluid is supplied from the high-pressure fluid supply pipe 14 into the movable inner cylinder 30 sleeve 34, and advances the movable inner cylinder 30 against the urging force of the spring 23. At this time, the ball valve 35 opens, and the high-pressure fluid is ejected from the high-pressure fluid ejection hole 32. The pressure of the high-pressure fluid, the direct line of the sleeve, the spring constant and the set length of the spring 23, the opening and closing pressure of the ball valve 35, and the like are appropriately determined and set by design.
[0022]
For example, an auger drill used for a prestressed concrete pile having an outer diameter of 600 mmφ can protrude the nozzle by about 90 mm.
[0023]
【The invention's effect】
Since the fluid ejection device of the auger drill of the present invention is configured as described above, it is possible to easily form a support bulb having an enlarged diameter on the support ground at the lower end of the concrete pile, which contributes to the enhancement of the support force of the pile. However, it is extremely large.
[Brief description of the drawings]
FIG. 1 is a side view of a lower end member of the embodiment; FIG. 2 is a view taken along the line AA in FIG. 1;
FIG. 3 is a longitudinal sectional view of a lower end member of the embodiment.
FIG. 4 is a partial cross-sectional view of FIG. 3, showing a state in which the diameter of the fluid ejection nozzle is expanded.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Lower end member 11 Connecting part 12 Shaft 13 Screw blade 14 Supply pipe 20 Injection nozzle 21 Fixed outer cylinder 22 Cap 23 Coil spring 30 Movable inner cylinder 31 Flange 32 High-pressure fluid ejection hole 33 Piece 34 Sleeve 36 Seal material 35 Ball valve 41 Knife 42 Bracket 43 Pin 51, 52 Drilling knife

Claims (2)

At the lower end of the tip member of the auger drill, a plurality of enlarged blades each having a pin connected at the upper end are hung, and the enlarged blade is rotated around the pin with the forward rotation of the auger drill, and the blade is enlarged in the radial direction. The outer diameter of the screw blade is 1.1 times the outer diameter of the screw blade when the outer diameter of the screw blade is projected in the expanding direction. An auger drill expanding device, wherein the diameter is in the range of up to 2.0 times. The high-pressure fluid injection nozzle attached to the side near the lower end of the auger drill is a double cylinder consisting of a fixed outer cylinder and a movable inner cylinder that moves forward and backward within a fixed distance within the fixed inner cylinder. A rear end is provided with a sealed sleeve for inserting a tip of a high-pressure fluid supply pipe at a rear end, and a spring for urging the inner cylinder in a retreating direction. An auger drill diameter increasing device, characterized in that an auger drill fluid ejecting device having a structure for advancing an inner cylinder is provided in parallel with the above.

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