JP6829420B2 - Drilling hole diameter expander - Google Patents

Description

The present invention relates to a drilling hole diameter expanding device, and more particularly to a drilling hole diameter expanding device for forming a large-diameter node in an intermediate portion of a drilling hole formed by an earth drill.

As a shape of cast-in-place concrete pile, a knotted pile (intermediate enlarged diameter pile) in which the diameter of the deepest pile head is expanded and the diameter of the intermediate portion is expanded to form a knot is known. In the middle node, the bottom surface of the node is formed in an inverted conical shape in order to prevent the concrete filling from being insufficient due to the step of the pile wall, and the bottom surface of the node is inverted conical. Various diameter expansion devices are used to form the concrete (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-177793

However, since the conventional diameter expansion device uses two diameter expansion blades formed so that the upper side can swing, the core may swing and become unstable due to one-sided contact during the diameter expansion work. It was. In addition, when removing slime after diameter expansion, the scraper member is bolted so as to cover the excavation blade of the diameter expansion blade, so it takes a lot of time and effort to change the work between diameter expansion and slime removal. Was there.

Therefore, an object of the present invention is to provide a drilling hole diameter-expanding device capable of suppressing runout during diameter-expanding work and easily changing the work contents between the diameter-expanding work and the slime removing work. ..

In order to achieve the above object, the drilling hole diameter expanding device of the present invention is a diameter expanding device connected to the lower end of the keriba via an upper connecting portion, and is a cylinder detachably connected to the lower end of the keriba. A support having a shape, a horizontal first support shaft and a second support shaft provided in the circumferential direction of the lower end portion of the support, and a lower end portion connected to the first support shaft so that the upper side can swing. The scraper wing formed in the above, the excavation wing formed by connecting the lower end to the second support shaft so that the upper side can swing, and the support can be moved up and down above the first support shaft. The first elevating member, the second elevating member provided above the second support shaft so as to be able to elevate in the vertical direction of the support, the first elevating member and the scraper blade are connected to each other, and the first elevating member is connected. The first link member that swings the scraper blade as the lift member moves up and down, the second lift member and the excavation blade are connected, and the excavation blade swings as the second lift member moves up and down. A plurality of the scraper blades are provided with a second link member to be moved, a blade opening / closing cylinder for raising and lowering the first elevating member, and a connecting member for detachably connecting the first elevating member and the second elevating member. And a plurality of the excavation blades are provided alternately at equal intervals in the circumferential direction around the support, and the excavation blades provided on the outer surface of the excavation blades are projected outward from the outer surface of the scraper blades. It is characterized by that.

Further, in the drilling hole diameter expanding device of the present invention, a lower connecting portion is provided at the lower end portion of the support, and a connecting member that detachably connects the first elevating member and the second elevating member. The same connecting pin is used for the connecting member that detachably connects the second lifting member elevating control member and the second elevating member provided on the upper side surface of the support, and the scraper blade. And the excavation blade is connected to the first support shaft or the second support shaft, and can be attached to and detached from the blade body to which the first link member or the second link member is connected and the tip of the blade body. It is characterized by being formed with an expansion wing to be mounted. In addition, the scraper blade and the excavation blade are provided with a scraping plate that projects diagonally inward from the side surface in the traveling direction, and the inside surface of the scraper blade and the excavation blade is internally provided. It is characterized by having a mountain-shaped protruding portion having a triangular cross section.

According to the drilling hole diameter-expanding device of the present invention, during the diameter-expanding work, the first elevating member and the second elevating member are lowered by the blade opening / closing cylinder to open the plurality of scraper blades and the plurality of excavation blades. Since the state is set, the occurrence of runout can be suppressed, and the diameter expansion work can be performed in a stable state. Further, when the slime is removed after the diameter expansion work, the connection between the first elevating member and the second elevating member is released, and only the first elevating member is lowered by the blade opening / closing cylinder to lower the plurality of scraper blades. Since it is possible to keep the scraper blade open, it is possible to easily change between the diameter expansion work in which the scraper blade and the excavation blade are opened and the slime removal work in which only the scraper blade is opened.

Furthermore, by connecting the bottom-draining bucket to the lower connecting portion provided at the lower end of the support, it is possible to more reliably prevent runout, and the excavated earth and sand can be dropped into the bottom-draining bucket, resulting in expanded diameter excavation. And the earth and sand can be discharged efficiently. Further, by using the same connecting pin for connecting the first lifting member and the second lifting member and connecting the second lifting member and the second lifting member, the diameter can be expanded by inserting and removing the connecting pin. And the slime removal work can be changed more easily. In addition, by forming the scraper blade and the excavation blade with the blade body and the expansion blade, the length of the expansion blade can be changed, so that the difference in the size of the enlarged diameter portion can be easily coped with.

An example of one form of the drilling hole diameter expanding device of the present invention is shown, and is a perspective view of the diameter expanding device showing a state in which the scraper blade and the drilling blade are opened. It is also the front view of the diameter expansion device seen from the scraper wing side. It is also a side view of the diameter expansion device seen from the excavation blade side. FIG. 2 is a sectional view taken along line IV-IV of FIG. It is a perspective view of the diameter expansion device which shows the state which the scraper blade and the excavation blade are closed. It is also the front view of the diameter expansion device seen from the scraper wing side. It is also a side view of the diameter expansion device seen from the excavation blade side. FIG. 6 is a cross-sectional view taken along the line VIII-VIII of FIG. It is a perspective view of the diameter expansion device which shows the state which the excavation blade is closed and the scraper blade is open. It is also the front view of the diameter expansion device seen from the scraper wing side. It is also a side view of the diameter expansion device seen from the excavation blade side. It is sectional drawing which shows the deformation example of the excavation blade. It is sectional drawing which shows the modification of the scraper expansion blade in the scraper blade. It is sectional drawing which shows the modification of the scraper blade main body in a scraper blade. It is a side view which shows the earth drill which attached the bottom expansion bucket. It is explanatory drawing which shows the state which formed the excavation hole using the excavation bucket. It is explanatory drawing which shows the state which the diameter of the excavation hole is expanded by using the bottom expansion bucket. It is explanatory drawing which shows the state which the excavation hole is formed downward from the part which expanded the diameter by using the excavation bucket. It is explanatory drawing which shows the preparatory stage for diameter-expanding excavation of the step part of the excavation hole intermediate diameter expansion part which expanded the diameter by using the diameter-expanding device and the bottom-drilling bucket. It is explanatory drawing which shows the state which the step part of the excavation hole intermediate diameter expansion part is excavated by diameter expansion using the diameter expansion device and the bottom-drilling bucket. Similarly, it is a figure which shows the state which the step part of the middle diameter expansion part of the excavation hole is expanded to a predetermined shape. It is explanatory drawing which shows the state which formed the excavation hole to a predetermined depth using the excavation bucket. It is explanatory drawing which shows the state which expanded the diameter of the excavation hole bottom part using the bottom expansion bucket. It is explanatory drawing which shows the preparatory stage for scraping earth and sand from the excavation hole intermediate diameter expansion part using a diameter expansion device and a bottom-drilling bucket. It is explanatory drawing which shows the state which scrapes the earth and sand from the middle diameter expansion part of the excavation hole by using the diameter expansion device and the bottom-drilling bucket. It is sectional drawing which shows the shape of the formed knotted excavation pile.

1 to 11 show an example of a form of a drilling hole diameter expanding device according to the present invention. FIGS. 1 to 4 show a state in which a scraper blade and a drilling blade are opened, and FIGS. 5 to 8 show a scraper. 9 to 11 show a state in which the blade and the excavation blade are closed, and FIGS. 9 to 11 show a state in which the excavation blade is closed and the scraper blade is opened.

The diameter-expanding device 11 shown in this embodiment is composed of a square tubular support 12, two scraper blades 13 and excavation blades 14 mounted on the side surfaces of the support 12 so as to be openable and closable, and the support 12. It is provided with a blade opening / closing cylinder 15 provided inside. The support 12 is formed in a square shape in a plan view, and an upper connecting portion 16 that is detachably connected to the lower end of the keriva is provided at the upper end, and an excavation bucket or a bottom bucket is provided at the lower end. A lower connecting portion 17 is provided for detachably connecting the two.

Further, the first support shaft 18 and the second support shaft 19 are alternately provided at 90-degree intervals at four locations in the circumferential direction of the lower end portion of the support body 12. The first support shaft 18 and the second support shaft 19 are horizontally supported by a pair of first shaft support members 18a and 18a and second shaft support members 19a and 19a projecting from the outer surface of the lower end portion of the support body 12, respectively. The lower end of the scraper blade 13 is rotatably connected to the first support shaft 18, and the lower end of the excavation blade 14 is rotatably connected to the second support shaft 19. As a result, the scraper blade 13 and the excavation blade 14 are formed so that the upper side can swing inward and outward with the support shafts 18 and 19 as the center.

Further, above the first support shaft 18, a first elevating member 20 capable of elevating and lowering the support 12 in the vertical direction is provided. The first elevating member 20 is provided so as to penetrate the vertically long openings 12a and 12a provided on the opposite side surfaces of the support body 12, and both ends project from the opposite side surfaces of the support body 12. .. The rod 15a of the blade opening / closing cylinder 15 is connected to the central portion 20a of the first elevating member 20 located inside the support 12 by a pin 15b. Further, above the second support shaft 19, a second elevating member 21 capable of elevating and lowering the support 12 in the vertical direction is provided. The second elevating member 21 is framed in a square shape along the four surfaces of the support 12, and is provided so as to surround the support 12 above the first elevating member 20.

In the horizontal direction for rotatably mounting the base end portion of the first link member 22 that connects the first elevating member 20 and the scraper blade 13 to the lower portion of the protruding portion of the first elevating member 20 protruding from the opening 12a. The first link mounting pin 23 is provided, and the connecting pin 24, which is a connecting member that detachably connects the first lifting member 20 and the second lifting member 21, can be inserted in the upper portion of the protruding portion in the horizontal direction. The first insertion hole 25 is provided.

In order to rotatably attach the base end portion of the second link member 26 that connects the second elevating member 21 and the excavation blade 14 to the portion of the second elevating member 21 located above the second support shaft 19. The second link mounting pin 27 is provided in the horizontal direction, and a second insertion hole 28 corresponding to the first insertion hole 25 is provided in a portion of the second elevating member 21 located above the first elevating member 20. A pair of projecting pieces 29, 29, respectively, are provided so as to sandwich the first elevating member 20. Further, a fixing hole 30 through which the connecting pin 24 can be inserted in the horizontal direction is provided above the second link mounting pin 27, and a through hole 31 corresponding to the fixing hole 30 is provided on the outer surface of the support 12. A pair of fixed projecting pieces 32, 32 having the same are provided so as to sandwich the fixing hole 30.

The scraper blade 13 is formed of a scraper blade body 33 whose base end is connected to the first support shaft 18, and a scraper expansion blade 34 detachably attached to the tip of the scraper blade body 33. The tip of the first link member 22 is rotatably connected to the intermediate portion of the scraper blade main body 33 via a rotation pin 35.

Similar to the scraper blade 13, the excavation blade 14 has an excavation blade body 36 whose base end is connected to the second support shaft 19 and an excavation expansion blade 37 detachably attached to the tip of the excavation blade body 36. The tip of the second link member 26 is rotatably connected to the intermediate portion of the excavation blade main body 36 via a rotation pin 38.

Further, the outer surface of the scraper blade 13 is provided with a scraper 13a for leveling the conical surface whose diameter has been expanded in an inverted conical shape, and the outer surface of the excavation blade 14 has an inverted conical diameter expanded excavation. An excavation blade 14a is provided. The scraper 13a and the excavation blade 14a are arranged at the front end edges of the scraper blade 13 and the excavation blade 14 in the rotational direction, respectively, and the excavation blade 14a is formed so as to project outward from the scraper 13a. As a result, when both the scraper blade 13 and the excavation blade 14 are opened for excavation, the excavation blade 14a excavates the earth and sand in the ground, and the scraper 13a is in a state of scraping the earth and sand (slime) generated by the excavation. ..

As shown in FIGS. 1 to 8, the excavation hole diameter expanding device 11 formed in this way includes the first insertion hole 25 of the first elevating member 20 and the second insertion hole 28 of the second elevating member 21. When the connecting pin 24 is inserted and the connecting pin 24 is not inserted into the fixing hole 30 and the through hole 31, the first elevating member 20 and the second elevating member 21 are connected to each other. 2 The elevating member 21 is in a state where it can be elevated. By extending the blade opening / closing cylinder 15 in this connected state, the scraper blade 13 and the excavation blade 14 can be opened at the same time as shown in FIGS. 1 to 4.

At this time, since the first elevating member 20 and the second elevating member 21 are integrally raised and lowered via the connecting pin 24, the scraper blade 13 and the excavation blade 14 can be opened and closed evenly. On the other hand, by shortening the blade opening / closing cylinder 15, as shown in FIGS. 5 to 8, the scraper blade 13 and the excavation blade 14 can be brought into a closed storage state along the outer surface of the support 12.

On the other hand, as shown in FIGS. 9 to 11, when the scraper blade 13 and the excavation blade 14 are in the retracted state, the connecting pin 24 is pulled out from the first insertion hole 25 and the second insertion hole 28, and the second elevating member 21 By inserting the connecting pin 24 into the fixing hole 30 of the above and the through hole 31 of the fixed projecting piece 32 provided on the outer surface of the support 12, the connection state between the first elevating member 20 and the second elevating member 21 is released. At the same time, the second elevating member 21 can be fixed to the support 12. By extending the blade opening / closing cylinder 15 in this state, only the scraper blade 13 is opened, and the slime removing operation is performed.

Therefore, it is possible to easily switch between the diameter-expanding work state in which the scraper blade 13 and the excavation blade 14 are opened and the slime removal work state in which only the scraper blade 13 is opened, simply by inserting and removing the connecting pin 24.

12 to 14 show modified examples of the scraper blade 13 and the excavation blade 14, respectively. First, FIG. 12 shows a modified example of the excavation blade 14, and is provided with a scraping plate 14b that projects obliquely inward from the center of the side surface of the excavation blade 14 in the traveling direction. By providing such a scraping plate 14b, it is possible to prevent the earth and sand excavated by the excavation blade 14a from crossing the excavation blade 14 rearward, and the earth and sand can be scraped in the inner peripheral direction. Further, by providing the scraper blade 13 with a similar scraping plate, the slime scraped by the scraper 13a can be effectively scraped in the inner peripheral direction.

13 and 14 show a modification of the scraper blade 13, and in FIG. 13, on the inner surface of the scraper expansion blade 34 in the scraper blade 13, and in FIG. 14, on the inner surface of the scraper blade body 33 in the scraper blade 13. The chevron-shaped protrusions 34a and 33a having a triangular cross section with the inside protruding are provided, respectively. By providing such mountain-shaped protrusions 34a and 33a, it is possible to prevent stones and the like from riding on the inner surface of the scraper expansion blade 34 during the diameter expansion work, and the scraper expansion blade 34 can be reliably closed. Further, depending on the shape of the chevron protrusions 34a and 33a, the stone sandwiched between the scraper blade 13 and the support 12 can be crushed and removed when the scraper blade 13 is closed. Such a mountain-shaped protrusion can also be provided on the excavation blade 14.

The diameter expanding device 11 is used when forming a knotted pile using the earth drill 51 shown in FIG. Hereinafter, a method of using the diameter expanding device 11 will be described with reference to FIGS. 16 to 26 showing the procedure for forming the knotted pile. The earth drill 51 rotatably suspends the telescopic kelly bar 54 from the tip of the boom 53 provided on the base machine 52 made of a crawler crane, and the kelly bar rotation drive device 56 from the base of the boom 53 with a cylinder 55 or the like. The excavation bucket, the bottom expansion bucket, and the like can be attached to the lower end portion of the crawler 54 inserted into the hollow cylindrical drive shaft provided in the crawler rotation drive device 56.

First, in the first stage, as shown in FIG. 16, an excavation bucket 57 is attached to the lower end of the kelly bar 54, and the excavation bucket 57 is pushed into the ground while being rotated by rotating the kelly bar 54 with the kelly bar rotation drive device 56. By alternately repeating the work of excavating the ground with the excavation blade 57a at the bottom and the work of pulling up the excavation bucket 57 and discharging the excavated earth and sand from the excavation bucket 57, the first of the preset depths. The vertical hole 71 is formed.

After forming the first vertical hole 71, as shown in FIG. 17, the excavation bucket 57 is replaced with the bottom expansion bucket 58, and the bottom expansion bucket 58 is rotated by rotating the keriva 54 to gradually open the bottom expansion blade 58a to form the vertical hole. The tapered portion 72 having a predetermined shape is formed by alternately repeating the work of expanding the bottom of the bottom 71 in a conical shape and the operation of pulling up the bottom expanding bucket 58 and discharging the excavated earth and sand from the bottom expanding bucket 58.

After forming the tapered portion 72, as shown in FIG. 18, the bottom expansion bucket 58 is replaced with the excavation bucket 57 again and the same operation as described above is repeated to form a second vertical hole 73 having a predetermined depth below the tapered portion 72. To do. By excavating and forming the second vertical hole 73 in this way, a step portion 74 having right-angled corners is formed at a portion where the bottom surface of the tapered portion 72 and the wall surface of the second vertical hole 73 intersect.

After forming the second vertical hole 73, the excavation bucket 57 is replaced with the diameter expanding device 11 as shown in FIG. The diameter-expanding device 11 uses the upper connecting portion 16 and the lower connecting portion 17, and a stabilizer 59 for suppressing the vibration of the diameter-expanding device 11 is mounted between the keriba 54 and the diameter-expanding device 11. Sediment excavated by the diameter-expanding device 11 is collected in the lower part of the diameter-expanding device 11, and a bottom bucket 60 for suppressing vibration of the diameter-expanding device 11 is connected. Further, when the upper and lower connecting portions are connected to each other, the occurrence of vibration can be more reliably reduced by forming the fitting lengths of the upper connecting portion 16 and the lower connecting portion 17 to be long.

The stabilizer 59 is formed so that the runout of the diameter expanding device 11 can be more reliably suppressed by bringing the stabilizer blade 59a into contact with the peripheral wall of the first vertical hole 71. Further, the bottom-draining bucket 60 does not have an excavation blade at the bottom, does not excavate downward even if it rotates, and has a structure in which the slime accumulated at the bottom of the vertical hole is lifted into the bucket and landed on the bottom. As a result, the diameter-expanding device 11 can be reliably held at the diameter-expanding work position.

Then, as shown in FIG. 20, the wheel tractor 54 is rotated with the bottomed bucket 60 landed on the bottom, the diameter expanding device 11 is rotated via the stabilizer 59, and the hydraulic oil supply unit 11a is rotated from a hydraulic hose (not shown). The hydraulic oil is supplied through the hose, the blade opening / closing cylinder 15 is extended, and the scraper blade 13 and the excavation blade 14 are gradually opened. As a result, the corner portion of the step portion 74 is gradually excavated by the excavation blade 14a of the excavation blade 14, and the diameter is expanded to form an inverted conical shape.

At this time, by landing the bottom-draining bucket 60 having no excavation function and performing the diameter-expanding work, the diameter-expanding work can be performed at a preset position without fixing the vertical direction of the keriba 54. it can. Even during this diameter expansion work, the work of discharging the earth and sand in the bottomed bucket 60 scraped off by the scraper blade 13 and the excavation blade 14 is appropriately repeated.

During the diameter-expanding work, the scraper blades 13 and the excavation blades 14 of the diameter-expanding device 11 are in a state of being evenly opened, so that the runout of the diameter-expanding device 11 can be suppressed. The diameter expansion work can be performed in a stable state. In particular, since the excavation blade 14a is projected outward from the scraper 13a, the scraper 13a does not scrape the unexcavated ground portion, and the excavation of the ground by the excavation blade 14a can be performed efficiently and reliably. ..

Further, by connecting the stabilizer 59 upward and the bottom bucket 60 downward to perform the diameter-expanding work, the core of the diameter-expanding device 11 can be more reliably held, and the corner portion of the step portion 74 can be held. Can be reliably excavated to form a preset inverted conical tapered surface 75.

As shown in FIG. 21, the step portion 74 is excavated by the diameter-expanding work of the diameter-expanding device 11 to form a node portion 76 having a tapered surface 75 having a predetermined shape, and then the stabilizer 59, the diameter-expanding device 11, and the bottom punching bucket are formed. The 60 is removed and the excavation bucket 57 is attached to the keriva 54 again, and as shown in FIG. 22, the second vertical hole 73 is further dug to form a third vertical hole 77 that reaches the support layer. At this time, when forming the knots at a plurality of positions in the middle of the vertical hole, the plurality of knots can be formed at appropriate positions of the vertical hole by repeating the procedure shown in FIGS. 17 to 21.

After forming the third vertical hole 77, as shown in FIG. 23, the excavation bucket 57 is replaced with the bottom expansion bucket 58, and the bottom portion of the third vertical hole 77 is expanded in a conical shape in the same manner as described above. As a result, the bottom-expanded portion 78 having a predetermined shape can be formed on the pile head. Next, as shown in FIG. 24, the bottom-expanding bucket 58 is replaced with the stabilizer 59, the diameter-expanding device 11, and the bottom-draining bucket 60. At this time, the connecting pin 24 is extracted from the first insertion hole 25 and the second insertion hole 28, the extracted connecting pin 24 is inserted into the fixing hole 30 and the through hole 31, and the second elevating member 21 is fixed to the support 12. Keep it.

Then, as shown in FIG. 25, the blade opening / closing cylinder 15 is extended at a position corresponding to the tapered surface 75, and only the scraper blade 13 is opened and rotated, so that the slime on the tapered surface 75 is bottomed out in the bucket 60. Drop it inside. As a result, the knot portion 76 in which slime is removed from the tapered surface 75 can be formed.

By sequentially performing the operations of FIGS. 16 to 25 in this way, the knotted pile 79 having a predetermined shape can be formed. In particular, since the diameter expansion work and the slime removal work can be switched only by inserting and removing the connecting pin 24, the switching between the two works can be easily performed in a short time. Further, by replacing the scraper expansion blade 34 and the excavation expansion blade 37 with those having appropriate lengths, the diameter expansion work of the nodes having different diameters can be easily performed.

In the above embodiment, the square tubular support is formed in a square shape and two scraper blades and two excavation blades are alternately provided. However, the support is formed in a hexagonal shape and the scraper blade is provided. And three drilling blades may be provided alternately. In addition, by connecting the excavation bucket to the lower connecting part of the diameter expander via a swivel, the rotation of the diameter expander can be prevented from being transmitted to the excavation bucket, so the excavation bucket is used instead of the bottom bucket. However, the diameter expansion device can be stabilized while avoiding downward excavation by the excavation bucket, and the excavated earth and sand can be discharged.

11 ... Diameter expander, 11a ... Hydraulic oil supply unit, 12 ... Support, 12a ... Opening, 13 ... Scraper blade, 13a ... Scraper, 14 ... Drilling blade, 14a ... Drilling blade, 14b ... Scraping plate, 15 ... Wing Opening and closing cylinder, 15a ... rod, 15b ... pin, 16 ... upper connecting part, 17 ... lower connecting part, 18 ... first support shaft, 18a ... first shaft support member, 19 ... second support shaft, 19a ... second Shaft support member, 20 ... 1st elevating member, 20a ... central part, 21 ... 2nd elevating member, 22 ... 1st link member, 23 ... 1st link mounting pin, 24 ... connecting pin, 25 ... 1st insertion hole, 26 ... 2nd link member, 27 ... 2nd link mounting pin, 28 ... 2nd insertion hole, 29 ... projecting piece, 30 ... fixing hole, 31 ... through hole, 32 ... fixed projecting piece, 33 ... scraper wing body, 34 ... Scraper expansion wing, 33a, 34a ... Crest-shaped protrusion, 35 ... Rotating pin, 36 ... Excavation wing body, 37 ... Excavation expansion wing, 38 ... Rotating pin, 51 ... Earth drill, 52 ... Base machine, 53 ... Boom, 54 ... Keriba, 55 ... Cylinder, 56 ... Keriba rotary drive, 57 ... Drilling bucket, 57a ... Drilling blade, 58 ... Expanding bucket, 58a ... Expanding wing, 59 ... Stabilizer, 59a ... Stabilizer wing, 60 ... Bucket, 71 ... 1st vertical hole, 72 ... Tapered part, 73 ... 2nd vertical hole, 74 ... Step part, 75 ... Tapered surface, 76 ... Knot part, 77 ... 3rd vertical hole, 78 ... Expanded bottom part, 79 ... Knotted pile

Claims (6)

A diameter-expanding device that is connected to the lower end of the keriba via an upper connecting portion, and is provided with a tubular support that is detachably connected to the lower end of the keriba and a peripheral direction of the outer surface of the lower end of the support. The first and second support shafts in the horizontal direction, the scraper blade whose lower end is connected to the first support shaft so that the upper side can swing, and the lower end are connected to the second support shaft. An excavation blade whose upper side is swingably formed, a first elevating member provided above the first support shaft so as to be able to move up and down in the vertical direction of the support, and a support above the second support shaft. A first link member that connects a second elevating member provided so as to be able to elevate in the vertical direction, the first elevating member, and the scraper wing, and swings the scraper wing as the first elevating member moves up and down. A second link member that connects the second elevating member and the excavation wing and swings the excavation wing as the second elevating member moves up and down, and a blade opening / closing for raising and lowering the first elevating member. A cylinder and a connecting member for detachably connecting the first elevating member and the second elevating member are provided, and a plurality of the scraper blades and a plurality of the excavation blades are provided in a circumferential direction around the support. An excavation hole diameter expanding device characterized in that the excavation blades provided on the outer surface of the excavation blade are alternately provided at equal intervals and the excavation blades are projected outward from the outer surface of the scraper blade. The drilling hole diameter expanding device according to claim 1, wherein a lower connecting portion is provided at the lower end portion of the support. A connecting member that detachably connects the first elevating member and the second elevating member, and a second elevating member elevating regulating member and the second elevating member provided on the upper side surface of the support are detachably connected. The drilling hole diameter expanding device according to claim 1 or 2, wherein the same connecting pin is used for the connecting member. The scraper blade and the excavation blade are connected to the first support shaft or the second support shaft, and the blade body to which the first link member or the second link member is connected and the tip of the blade body. The drilling hole diameter expanding device according to any one of claims 1 to 3, wherein the expansion blade is formed of a detachably mounted expansion blade. The expansion of the excavation hole according to any one of claims 1 to 4, wherein the scraper blade and the excavation blade are provided with a scraping plate that projects obliquely inward from the side surface in the traveling direction. Diameter device. The drilling hole diameter expanding device according to any one of claims 1 to 5, wherein a mountain-shaped protruding portion having a triangular cross section is provided on the inner side surface of the scraper blade and the excavating blade. ..

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