JP2004346586A - Excavating apparatus with expansion blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To positively open and close blades without using a complicated opening/closing mechanism such as a hydraulic cylinder in an excavating apparatus with expansion blades used for providing an enlarged diameter part at a part of an excavated hole in building and civil engineering soil improvement and anchor and pile foundation work of a slope or the like. <P>SOLUTION: This excavating apparatus with the expansion blades is mounted with an expansion blade apparatus in a prescribed position of an excavating rod 41, wherein the expansion blade apparatus is provided with a rotating direction opening/closing mechanism for opening and closing the expansion blades 46 in the rotating direction using resistance generated between the expansion blades 46 and a hole wall or excavated soil by the reverse and normal rotation of the excavating rod 41, and an axial closing mechanism for closing the expansion blades 46 in the axial direction of the excavating rod using force applied to the expansion blades 46 by moving the excavating rod in a pull-out direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drilling device having an enlarged wing used for anchoring a building or civil engineering, improving a ground of a civil engineering work, a slope or the like, or performing pile foundation work.
[0002]
[Prior art]
As a means for increasing the supporting force and pull-out resistance of the pile, an expanded part having a diameter larger than the diameter of the pile is previously formed at the bottom of the pile hole, and cement milk or the like is poured into the expanded part to fix the roots. Forming is being done.
[0003]
2. Description of the Related Art Conventionally, for example, Patent Literature 1 and Patent Literature 2 disclose a bottom expanding device for forming a bottom expansion portion at the bottom of the above-described pile hole.
[0004]
Also, for example, when constructing a structure such as a building on a site with poor ground conditions such as soft ground or embankment landfill, a plurality of enlarged portions are provided at required intervals in the pile axis direction, that is, in the depth direction, and joints are provided. There is also a construction method that increases the peripheral friction by forming a pile shape.
[0005]
Further, as one of the construction methods for fixing a structure such as a building to the ground, there is an anchor construction method using an anchor member. This anchor member is formed by drilling a hole in the ground (slope, etc.), inserting a tension member such as a steel rod into the hole, and fixing the anchor fixing portion at the tip of the tension member with a mortar or the like pressed into the hole. And the head is tightened with a jack and fixed to the structure with screws or wedges, and the structure is fixed to the ground via this anchor member. Even in such an anchoring method, an expanded bottom portion is provided at the bottom of a hole serving as an anchor fixing portion in order to form a strong anchor member.
[0006]
[Patent Document 1]
JP-A-9-25779 [Patent Document 2]
JP-A-11-6382
[Problems to be solved by the invention]
The above-mentioned conventional bottom expanding device has the following problems.
[0008]
The bottom expanding device described in Patent Literature 1 is a mechanism that opens the blade by utilizing the resistance of the ground by reverse rotation and closes the blade by forward rotation. However, in order to close the blade in forward rotation, a certain amount of frictional force with the hole wall or excavated soil is required, and the blade cannot be closed on loose ground. In addition, there are cases where clay or the like is clogged at the base of the wing expansion mechanism or rotates together with the wing expansion mechanism so that the wing cannot be completely closed.
[0009]
The bottom expanding device described in Patent Literature 2 has a structure in which the expansion is performed by raising and lowering an expansion bit. In this device, the timing of ascending and descending is performed by the movement of the clutch. However, in actuality, the clutch may rotate and may not move.
[0010]
The above-mentioned bottom-expanding device is to be collected and used repeatedly after excavation is completed. However, if the enlarged blade (extended bit) cannot be closed, it cannot be collected. In the worst case, the bottom-expanding device and the excavating head are separated from the rod and soil is removed. There was a problem that a case where it had to be left inside occurred.
[0011]
For example, if a hydraulic cylinder or the like is used to open and close the enlarged blade (enlarged bit), the enlarged blade can be forcibly opened and closed, so that the expanded blade can be reliably maintained in a closed state and an open state. Are complicated and expensive.
[0012]
Therefore, the present invention is to provide a novel drilling device used to provide a large diameter portion in a part of a drilling hole in the ground improvement of construction and civil engineering, anchors such as slopes and pile foundation work, In particular, an object of the present invention is to provide an excavator with enlarged wings that can reliably open and close wings without using a complicated opening / closing mechanism such as a hydraulic cylinder.
[0013]
[Means for Solving the Problems]
The excavator with an enlarged wing according to the present invention that solves the above-mentioned problem uses the resistance generated between the enlarged wing and the hole wall or excavated soil by the reverse / forward rotation of the excavation rod to move the enlarged wing in the rotation direction. In order to close the enlarged wing in the axial direction of the drilling rod by using a rotating direction opening / closing mechanism for opening and closing the blade and a force acting on the enlarged wing by moving the drilling rod in the pulling direction. And an enlarged wing device having the axial closing mechanism described above is attached to a predetermined position of a drilling rod.
[0014]
ADVANTAGE OF THE INVENTION According to the drilling apparatus with an enlarged wing of this invention, not only the rotation direction opening / closing mechanism which opens and closes an enlarged wing in the rotation direction of a drilling rod, but also utilizes the force which acts on the enlarged wing when pulling out a drilled rod. By providing an axial closing mechanism that closes the enlarged wing in the axial direction of the excavation rod, even if the ground is loose and the frictional force with the hole wall or excavated soil is not sufficient, the enlarged wing can be reliably closed. can do.
[0015]
The excavator with an enlarged wing of the present invention has, as a further feature,
"The axial closing mechanism is to function when the closing of the expanding wing by the rotating direction opening / closing mechanism is insufficient."
"The axial closing mechanism has a structure that does not function in a state where the enlarged wing is opened in the rotational direction when the drilling rod is rotated in reverse."
"A drilling head is attached to the tip of the drilling rod, the magnifying wing device is mounted at a position near the upper portion of the drilling head, and a screw auger for discharging excavated soil to the ground is mounted above the magnifying wing device. That will be used for the pre-drilling method of pre-casting. ",
"A plurality of the expanding wing devices are attached at predetermined intervals in the length direction of the drilling rod",
Is included.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The most significant features of the excavator with an enlarged wing of the present invention are a rotating direction opening / closing mechanism that opens and closes the enlarged wing in the direction of rotation of the drilling rod, and an axial closing mechanism that closes the enlarged wing in the axial direction of the drilled rod. An enlarged wing device having a mechanism is attached to a predetermined position of a drilling rod. First, the basic structures of these mechanisms in the enlarged wing device of the present invention are shown in conceptual diagrams of FIGS. It will be described based on the following.
[0017]
1 shows a state in which the enlarged wing is closed in the rotational direction, FIG. 2 shows a state in which the enlarged wing is opened in the rotational direction, and FIG. 3 shows a state in which the enlarged wing is in the axial direction of the drilling rod (that is, in the depth direction). FIGS. 4A and 4B show a state in which the blades are closed, wherein FIG. 4A is a top view and FIG. In these figures, 11 is a drilling rod (rotation axis), 12 is a support block, 13 is a depth direction support axis, 14 is a mechanism block, 15 is a rotation direction support axis, and 16 is an enlarged wing.
[0018]
In this enlarged wing device, a support block 12 is fixed to a predetermined position of a drill rod 11. A mechanism block 14 is connected to the support block 12 by a depth direction support shaft 13 so as to be rotatable in a depth direction (for example, a vertical direction). Further, an expansion wing 16 is connected to the mechanism block 14 by a rotation direction support shaft 15 so as to be rotatable in a rotation direction (for example, in a horizontal plane direction).
[0019]
The enlarged wing device of the present invention is connected to a screw auger or the like via a mounting shaft (not shown) provided at the upper end of the drilling rod 11, for example, in a state where the blade is closed in the rotational direction as shown in FIG. Is what is done.
[0020]
When the excavating rod 11 is reversed in the state of FIG. 1 (arrow A in FIG. 1A), the tip wall of the enlarged wing 16 is acted on by the hole wall in the direction of arrow B or the resistance of excavated soil. As shown in FIG. 7, the expanding wing 16 is opened. After excavation with the hole diameter enlarged in this state, it is necessary to close the enlarged wing 16 in order to pull up the excavation rod and collect the enlarged wing device.
[0021]
Closing of the enlarged wing 16 is performed by rotating the excavating rod 11 in the normal direction (arrow C in FIG. 2A) and applying a resistance force of a hole wall or excavated soil in the direction of arrow D to the tip of the enlarged wing 16. be able to. However, there is a case where the blade cannot be closed on loose ground by the above-mentioned resistance alone. Further, there are cases where clay or the like is clogged at the base of the enlarged wing 16 and the wing cannot be completely closed.
[0022]
Therefore, in the present invention, as an emergency means, a force acting on the expanding wing 16 in the open wing state shown in FIG. 2 by moving the digging rod 11 in the pulling direction (the digging rod indicated by an arrow E in FIG. By using the force in the axial direction), the enlarged wing 16 can be closed in the depth direction as shown in FIG. That is, the mechanism block 14 to which the enlarged wing 16 is connected rotates around the depth direction support shaft 13, so that the enlarged wing 16 can be closed in the depth direction.
[0023]
The force acting on the enlarged wing 16 by moving the excavating rod 11 in the pulling-out direction is, for example, a force received from the lower surface of a hollow preformed pile such as a steel pipe pile in the case of the middle digging expanded root consolidation method, and It is the force received from the upper surface of the enlarged diameter portion in the case of performing the compacting method, the method of excavating the above-described knotted pile-shaped hole or the anchor member.
[0024]
As described above, in the excavator with an enlarged wing of the present invention, the ground is loosened only by using the force acting on the enlarged wing 16 in each step of excavating a hole without using a complicated opening and closing mechanism such as a hydraulic cylinder. Even when the frictional force with the hole wall or excavated soil is not sufficient, the blade can be opened and closed without fail.
[0025]
Next, a specific embodiment of the excavating device with enlarged wings of the present invention will be described by taking a case where the present invention is used for the medium digging and expanding method for solidifying a rock, as an example, but the present invention is limited to these embodiments. Instead, the replacement of each member or the like within the scope of the present invention is permitted.
[0026]
(First Embodiment)
The basic structure of the excavator with enlarged wings of this example is the same as that shown in FIGS. FIG. 4 is a perspective view showing a state in which the enlarged wing device of the present example is mounted on the tip of a screw auger, and the enlarged wing is opened in the horizontal direction (the rotation direction of the drilling rod).
[0027]
The excavation rod 41 is a hollow body having a rooting material discharge hole (not shown) opened at the lower end, and a mounting shaft 41 a (see FIG. 5) provided at an upper end portion of the excavation rod 41 has a screw auger. It is inserted into the lower end of 50 and fixed. In addition, the said consolidation material discharge hole can discharge compressed air or high-pressure water in addition to the consolidation material.
[0028]
A support block 42 is fixed to the excavation rod 41, and a mechanism block 44 is connected to both sides of the excavation rod 41 by a vertical (depth) direction support shaft 43 so as to be rotatable in the vertical direction. Further, an enlarged wing 46 is connected to the mechanism block 44 by a horizontal support shaft 45 so as to be rotatable in the horizontal direction.
[0029]
The enlarged wing 46 has a substantially rectangular shape, and the tip is formed at an acute angle to be a digging end. In addition, a hard excavation nail is protruded downward from the tip as needed.
[0030]
The excavation head 60 is attached to the tip of the excavation rod 41. Two screws 61 are spirally formed on the outer periphery of the excavating head 60, and excavating claws 62 are attached to lower ends of the screws 61.
[0031]
As in the present example, a drilling head 60 is attached to the tip of the drilling rod 41, an enlarged wing device is provided at a position near the top of the drilled head 60, and a screw auger for discharging the excavated soil to the ground above the enlarged wing device. By attaching 50, it is possible to use it for the mid-digging and expansion of the prefabricated pile.
[0032]
An example of execution of the middle digging method for expanding the foundation by the excavator with enlarged wings of the present embodiment will be described with reference to cross-sectional views of FIGS.
[0033]
First, an excavator with an enlarged wing is inserted into a hollow portion of a hollow prefabricated pile 51, and excavation until reaching a predetermined depth from the ground is performed by closing the enlarged wing 46 as shown in FIG. 41 is rotated forward and the excavation is performed by the excavation claw 62. Then, the ready-made pile 51 is buried following the progress of the excavation.
[0034]
When the excavation proceeds to a predetermined depth, as shown in FIG. 6, the excavation rod 41 is reversed and the enlarged wing 46 is opened by utilizing the friction with the hole wall or excavated soil, and the excavation diameter is enlarged to increase the bottom of the pile hole. The excavation 70 with a diameter larger than the pile diameter is excavated.
[0035]
When the enlarging portion 70 is formed, the embedding material is injected from the embedding material discharge hole, and the excavating rod 41 is repeatedly moved up and down between the expanding portion 70 and the ready-made stake 51 so that the embedding material and the surrounding earth and sand, Stir and mix with sand and gravel, etc. to form solidified bulbs.
[0036]
Next, the excavating rod 41 is rotated forward to close the expanding wing 46, and is lifted to the ground as it is. At this time, even if clay or the like cannot be closed because the base of the enlarged wing 46 is clogged with clay or the like, the upper surface of the enlarged wing 46 hits the tip (lower surface) of the ready-made pile 51 as the drilling rod 41 is pulled up, as shown in FIG. Thus, the expansion wing 46 can be forcibly closed. Finally, the rotation of the excavating rod 41 is stopped, and the tip of the ready-made pile 51 is pressed into the expanded bottom 70 to complete the construction.
[0037]
The axial closing mechanism for closing the enlarged wings 46 in the vertical direction in this example is mainly configured by the vertical (depth) direction support shaft 43 and the mechanism block 44, and has an extremely simple configuration. In this case, the vertical (depth) direction support shaft 43 and the mechanism block 44 are connected to each other so that the expanding wing 46 does not close in the vertical direction while the excavating rod 41 is rotated in the reverse direction to excavate the expanded bottom portion 70. Has moderate frictional resistance between them. This frictional resistance can be set to a desired size using, for example, a coil spring.
[0038]
(Second Embodiment)
The basic structure of the excavator with enlarged wings of this example is the same as that of the first embodiment, but in this example, the enlarged wings are opened in the horizontal direction (rotational direction) when the excavation rod reverses. Is characterized by having a structure in which the axial closing mechanism does not function.
[0039]
8 and 9 show a characteristic structure of the enlarged wing device of this example. 8 shows a state in which the enlarged wing 46 is closed in the horizontal direction. FIG. 8A is a plan view, and FIG. 8B is a vertical cross-sectional view taken along the line XX ′ in FIG. is there. FIG. 9 shows a state in which the enlarged wing 46 is opened in the horizontal direction due to the resistance of the hole wall or the excavated soil due to the reversal of the excavation rod. FIG. 9 (a) is a plan view, and FIG. FIG. 10 is a vertical sectional view taken along the line YY ′ in FIG.
[0040]
In the enlarged wing device of this example, a spring mechanism 81 is inserted at the tip of the vertical (depth) direction support shaft 43 as shown in the figure. A projection 82 is provided at an intermediate portion of the vertical support shaft 43, and a rotation groove 83 and a restriction groove 84 are formed inside the mechanism block 44.
[0041]
As shown in FIG. 8, when the excavation rod is stopped or normally rotated, the mechanism block 44 is pressed toward the support block 42 by the spring mechanism 81. In this state, the projection 82 is located in the rotation groove 83, and the mechanism block 44 to which the enlarged wing 46 is connected can rotate vertically downward around the vertical support shaft 43. That is, when stopping the rotation of the excavating rod and lifting the excavating rod, when the downward force acts on the expanding wing 46 in the open wing state, the expanding wing 46 can be closed in the vertical direction.
[0042]
On the other hand, as shown in FIG. 9, when the excavation rod rotates in the reverse direction, the spring mechanism 81 is compressed, and the mechanism block 44 is separated from the support block 42. In this state, the projection 82 is positioned outside the rotation groove 83 and in the restraining groove 84, and the mechanism block 44 to which the enlarged wing 46 is connected rotates around the vertical support shaft 43. Can not. That is, while the excavation rod is rotated in the reverse direction to excavate the enlarged bottom, the enlarged wing 46 does not close in the vertical direction.
[0043]
In the present embodiment, the mechanism block 44 is separated from the support block 42 when the excavating rod is rotated in the reverse direction. Is provided.
[0044]
In addition, since the spring mechanism 81, the projection 82, the rotation groove 83, and the restraining groove 84 are all formed inside the mechanism block 44, clay or the like enters these parts, and these functions are impaired. The desired function can be surely exerted without worrying about being performed.
[0045]
As described above, by adding a structure in which the axial closing mechanism does not function when the enlarged wing is opened in the horizontal direction due to the resistance of the hole wall or excavated soil due to the reversal of the excavating rod, the excavated bottom is excavated. Even if a downward force is applied to the expanding wing, the wing does not close, and it is possible to reliably form the expanded bottom portion having a desired size.
[0046]
(Third Embodiment)
The basic structure of the excavating device with enlarged wings of this example is the same as that of the first embodiment, but as in the second embodiment, the enlarged wings are horizontally (rotated) when the excavating rod is reversed. It is characterized in that it has a structure in which the axial closing mechanism does not function when the blade is open.
[0047]
FIGS. 10 and 11 are cross-sectional views of the vertical (depth) direction support shaft 43, which is a characteristic structure of the enlarged wing device of the present example, around the distal end. FIG. 10 shows a state where the enlarged wing is closed in the horizontal direction when the excavation rod stops or rotates forward, and (b) is a cross-sectional view taken along the line ZZ ′ in (a). FIG. 11 shows a state in which the enlarged wing is opened in the horizontal direction when the drilling rod is rotated in the reverse direction.
[0048]
In the enlarged wing device of this example, a spring mechanism 91 is inserted at the tip of the vertical (depth) direction support shaft 43 as in the second embodiment. Eight fitting projections 92 projecting toward the mechanism block 44 are formed at the tip of the vertical support shaft 43, and eight fitting projections are formed on the surface of the mechanism block 44 facing the fitting projection 92. A recess 93 is formed.
[0049]
As shown in FIG. 10, when the excavation rod stops or rotates forward, the mechanism block 44 is pressed toward the support block by the spring mechanism 91. In this state, the fitting projection 92 is disengaged from the fitting recess 93, and the mechanism block 44 to which the enlarged wing is connected can rotate vertically downward around the vertical support shaft 43. That is, when stopping the rotation of the excavating rod and pulling up the excavating rod, when a downward force acts on the expanding wing in the open wing state, the expanding wing can be closed in the vertical direction.
[0050]
On the other hand, as shown in FIG. 11, when the excavation rod is rotated in the reverse direction, the spring mechanism 91 is compressed, and the fitting projection 92 and the fitting recess 93 are fitted. In this state, the mechanism block 44 to which the enlarged wing is connected cannot rotate around the vertical support shaft 43. That is, while the excavation rod is reversed to excavate the expanded bottom, the expanded wing does not close in the vertical direction.
[0051]
In addition, since the spring mechanism 91, the fitting protrusion 92, and the fitting recess 93 are all formed inside the mechanism block 44, there is a concern that clay or the like may enter these parts to impair these functions. Therefore, a desired function can be surely exhibited.
[0052]
Also in the case of this example, by adding a structure in which the axial closing mechanism does not function in a state where the expanding wing is horizontally opened due to the resistance of the hole wall or excavated soil due to the reversal of the drilling rod, the expanded bottom portion is formed. Even if a downward force acts on the expanding wing during excavation, the blade does not close, and a desired expanded bottom portion can be reliably formed.
[0053]
(Fourth Embodiment)
The basic structure of the excavator with enlarged wings of this example is the same as that shown in FIGS. 1 to 3, but the axial closing mechanism of this example holds the enlarged wings in the horizontal direction (rotation direction). It is characterized in that it has a structure in which the support plate is sheared by a downward force acting on the expanding wing and the support plate is sheared in the axial direction (vertical direction).
[0054]
FIG. 12 shows a characteristic structure of the excavator with enlarged wings of this example. FIGS. 12A and 12B show a state in which the enlarged wing is opened in the rotation direction, where FIG. 12A is a top view and FIG. 12B is a side view.
[0055]
As shown in FIG. 12, a support plate 94 is fixed to the lower surface of the support block 12 by bolts (not shown). The portion of the support plate 94 that contacts the lower surface of the mechanism block 14 is formed in a comb shape and is designed to be sheared by applying a predetermined shearing force.
[0056]
In the excavator with enlarged wings of this example, when the enlarged wings 16 open horizontally to perform excavation and agitation, the mechanism block 14 is fixed by the comb-like portions of the support plate 94 to support the vertical (depth) direction. It cannot rotate around the shaft 13. On the other hand, after the end of the excavation and stirring, the expanding wing 16 can be closed in the vertical direction by shearing the comb-tooth-like portion using the force for lifting the excavating rod 11.
[0057]
Also in the case of this example, even if the downward ground resistance acts on the enlarged wing during excavation and stirring of the enlarged bottom, the blade does not close, so that the desired enlarged bottom can be reliably formed. By shearing the support plate using the force for lifting the excavating rod, the expanded wing 16 in the open wing state can be reliably closed in the vertical direction.
[0058]
As described above, the embodiment in which the excavator with an enlarged wing according to the present invention is used for the medium digging and expansion method for solidifying a rock is described. For example, the enlarged wing device described above is provided at a predetermined interval in the length direction of the excavation rod. When a plurality of holes are attached, the method can be suitably used in the above-described method of excavating the knotted pile-shaped hole. That is, after digging until reaching a predetermined depth in a state where all the enlarged wings are closed in the rotation direction, the excavating rod is reversed, and all the enlarged wings are opened by using the resistance force of the hole wall or excavated soil to excavate. By doing so, it is possible to excavate a plurality of enlarged diameter portions at a time. Further, even when a plurality of enlarged wing devices are provided, all of the enlarged wings can be reliably closed, so that a plurality of desired enlarged diameter portions can be formed at the same time.
[0059]
【The invention's effect】
As described above, according to the excavator with an enlarged wing of the present invention, the rotation that opens and closes the enlarged wing in the rotational direction using the resistance of the hole wall or excavated soil due to the reverse rotation / forward rotation of the drill rod. Not only the directional opening / closing mechanism but also the axial closing mechanism that closes the expanding wing in the axial direction of the drilling rod by using the force acting on the expanding wing when pulling out the drilling rod makes the ground loose and Even when the frictional force with the wall or the excavated soil is not sufficient, the expansion wing can be reliably closed. This makes it possible to reliably collect and reuse the relatively expensive wing-spread head after the excavation is completed.
[0060]
In particular, if the structure in which the axial closing mechanism does not function when the expanding wing is opened in the rotation direction when the drilling rod reverses is used, the expanding wing closes during excavation and stirring of the enlarged diameter portion. Thus, the desired enlarged diameter portion can be formed without fail.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram for explaining a basic structure of a rotation direction opening / closing mechanism and an axial direction closing mechanism in an excavator with an enlarged wing according to the present invention, showing a state where the enlarged wing is closed in a rotational direction. Show.
FIG. 2 is a conceptual diagram for explaining a basic structure of a rotation direction opening / closing mechanism and an axial direction closing mechanism in the excavator with an enlarged wing according to the present invention, showing a state where the enlarged wing is opened in the rotational direction. Show.
FIG. 3 is a conceptual diagram for explaining a basic structure of a rotating direction opening / closing mechanism and an axial closing mechanism in the excavator with an enlarged wing according to the present invention, wherein the enlarged wing is closed in an axial direction (depth direction). Indicates a state in which
FIG. 4 is a diagram showing a state in which the excavator with enlarged wings according to the first embodiment of the present invention is mounted on the tip of a screw auger.
FIG. 5 is a cross-sectional view for explaining a construction procedure of a middle digging expanded root consolidation method by a digging device with enlarged wings according to the first embodiment of the present invention.
FIG. 6 is a cross-sectional view for explaining a construction procedure of a middle digging expanded root consolidation method by a digging device with enlarged wings according to the first embodiment of the present invention.
FIG. 7 is a cross-sectional view for explaining a construction procedure of a middle digging enlarged root consolidation method by the digging device with enlarged wings according to the first embodiment of the present invention.
FIG. 8 is a diagram showing a characteristic structure of an enlarged wing device according to a second embodiment of the present invention.
FIG. 9 is a view showing a characteristic structure of an enlarged wing device according to a second embodiment of the present invention.
FIG. 10 is a cross-sectional view showing a characteristic structure of an enlarged wing device according to a third embodiment of the present invention.
FIG. 11 is a cross-sectional view showing a characteristic structure of an enlarged wing device according to a third embodiment of the present invention.
FIG. 12 is a diagram showing an enlarged wing device according to a fourth embodiment of the present invention.
[Explanation of symbols]
11 Drilling rod (rotary axis)
12 Support block 13 Depth direction support shaft 14 Mechanism block 15 Rotation direction support shaft 16 Magnified wing 41 Drilling rod (rotary shaft)
41a Mounting shaft part 42 Support block 43 Vertical (depth) direction support shaft 44 Mechanism block 45 Horizontal support shaft 46 Enlarged wing 47 Projection part 50 Screw auger 51 Ready-made pile 60 Excavation head 61 Screw 62 Excavation claw 70 Enlarged bottom part 81 Spring mechanism 82 Projection 83 Rotation groove 84 Restriction groove 91 Spring mechanism 92 Fitting convex portion 93 Fitting concave portion 94 Support plate

Claims (5)

A rotation direction opening / closing mechanism for opening / closing the enlarged wing in the rotational direction by utilizing resistance generated between the enlarged wing and a hole wall or excavated soil due to reverse / forward rotation of the excavation rod; An axial wing mechanism including an axial closing mechanism for closing the expanding wing in the axial direction of the excavation rod by utilizing a force acting on the expanding wing by moving the rod in the pulling direction. An excavator with enlarged wings attached to a predetermined position of a rod. 2. The excavator with an enlarged wing according to claim 1, wherein the axial closing mechanism functions when the closing of the enlarged wing by the rotation opening and closing mechanism is insufficient. 3. 3. The excavator with an enlarged wing according to claim 1, wherein the axial direction closing mechanism has a structure that does not function when the enlarged wing is opened in a rotational direction when the excavation rod rotates in the reverse direction. 4. A drilling head is attached to the tip of the drilling rod, the expanding wing device is mounted at a position near the upper portion of the drilling head, and a screw auger for discharging the excavated soil to the ground is mounted above the expanding wing device. The excavator with enlarged wings according to any one of claims 1 to 3, wherein the excavator is used in a pre-drilling method for excavating a ready-made pile. The excavator with an enlarged wing according to any one of claims 1 to 3, wherein a plurality of the enlarged wing devices are attached at predetermined intervals in a length direction of the excavation rod.

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