JP4699304B2 - Widened bucket - Google Patents

Description

  The present invention relates to a bottom-up bucket for forming a bottom-up portion that is larger than a shaft portion in a portion that becomes a bottom portion of a pile.

  2. Description of the Related Art Conventionally, an expanded pile as a cast-in-place concrete pile in which an expanded bottom portion that is larger than a shaft portion is provided at a portion that becomes a bottom portion of the pile is known (see Patent Documents 1 and 2).

  This bottomed pile has a standpipe built on the ground, the inside of which is excavated by an excavator to form a shaft part, and the bottom part of the bottomed pile is gradually expanded with a bottomed bucket to cut the bottom part Build by forming the part that becomes.

This widened portion is constituted by a frustoconical widened inclined portion whose diameter gradually expands downward and a cylindrical vertical portion provided therebelow.
JP 2001-164867 A JP 59-490A

  However, since the ground forming the expanded bottom portion is a ground serving as a support layer for the pile, there are many hard grounds, and cutting with a conventional expanded bottom bucket may be difficult.

  Then, this invention aims at providing the bottom expansion bucket which can form the bottom expansion part of a pile easily even if it is a hard ground.

In order to achieve the above object, a bottom-up bucket of the present invention is a bottom-up bucket for forming a bottom-up portion having a diameter larger than that of a shaft portion at a portion to be a bottom portion of a pile, and a cylindrical main body portion and A widened wing portion that is openable so as to increase the diameter of the main body portion, and a transmission shaft portion that receives a force from a kelly bar of an earth drill is provided inside the main body portion above and below the main body portion. The lower end of a connecting member that is arranged so as to be movable in the direction and is flexibly connected to the transmission shaft portion is connected to the widened wing portion, and the transmission shaft portion is attached to the inside of the main body portion. The guide tube is slidably accommodated in the guide tube .

Here, a slide groove inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide cylinder, and a connecting portion between the transmission shaft portion and the connecting member is protruded from the slide groove, It can be set as the structure which moves the said transmission shaft part to a guide to an up-down direction.

  Moreover, it is preferable that the protrusion part is formed in the lower end of the said main-body part below the said widening wing | blade part. Here, an annular stabilizer that adjusts the diameter of the protrusion can be detachably provided.

  Further, the widened wing portion is formed in a shape in which an equal width portion having a substantially constant width is formed in the vicinity of the lower end, and the upper portion thereof is tapered, and the roller bit is formed at a side end portion of the equal width portion. The plate-shaped cutting plate blade portion can be configured to be switchable.

  In addition, a transmission shaft for receiving a force from the ground drill kelly bar is disposed inside the main body so as to be movable in the vertical direction of the main body, and is flexibly connected to the transmission shaft. A lower end of the connecting member is connected to the widened wing portion, and a reduction device may be interposed between the lower end of the kelly bar and the transmission shaft portion.

  Here, the transmission shaft portion is slidably accommodated in a guide tube attached to the inside of the main body portion, and the transmission shaft portion depends on the height of an opening adjustment plate that is detachably attached to the upper end of the guide tube. It can be configured such that the amount of downward movement of the transmission shaft portion is set.

A fixed bit can be fixed between the roller bit and the roller bit at the side end of the widened wing.

The widened bucket of the present invention configured as described above can smoothly open and close the widened wing portion by providing the guide cylinder with a slide groove obliquely and moving the transmission shaft portion up and down along the slide groove. For this reason, even if it is a hard ground, it can be easily expanded.

In addition, a plurality of rotatable roller bits are provided at the side end of the widened wing , and the roller bits can be cut into the ground so that the ground sandwiched between the grooves becomes brittle. Makes it easier to cut. Furthermore , by fixing the fixed bits between the roller bits, the ground between the grooves formed by the roller bits can be efficiently scraped off by the fixed bits.

  Furthermore, the protrusion can be supported on the ground by forming the protrusion at the lower end of the main body below the widened wing.

  For this reason, even if the reaction force of the ground acts on the main body when opening the widened wing, it is restrained by the ground by the projecting part and the position of the lower end does not move, so it does not shift to one side and has an accurate shape An expanded bottom can be formed.

  Also, if the diameter of the excavation hole before the bottom expansion is larger than the diameter of the bottom expansion bucket, adjust the diameter of this projecting part by attaching an annular stabilizer so that the center position is not blurred. An expanded bottom portion can be formed.

  In addition, by configuring the side edge of the equal width portion of the widened blade to be switched to the cutting plate blade, the excavation wall surface of the widened portion formed in a groove shape with a roller bit can be made clean with no irregularities. Can be molded.

  Furthermore, even if the earth drill is a relatively small machine with a small torque by interposing a reduction gear between the earth drill kelly bar for applying the torque and the transmission shaft portion to which the torque is transmitted. Hard ground can be expanded.

  Also, if the opening adjustment plate is attached to the upper end of the guide cylinder that slides the transmission shaft, and the amount of movement of the transmission shaft can be set at the height, the bottom expansion can be accurately and efficiently sized to the desired size. Can be formed.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing a configuration of a bottomed bucket 1 according to the present embodiment that is used when a bottomed pile in which the bottom of the pile is larger than the diameter of the shaft portion is constructed.

  First, from the configuration, the bottom expansion bucket 1 of the present embodiment includes a cylindrical main body portion 11 and two widened blade portions 12 formed so as to be openable so as to increase the diameter of the main body portion 11. 12.

  The bottomed bucket 1 is a device that is attached to an earth drill (not shown). Specifically, a pin or the like is provided at the lower end of the kelly bar 2 of the earth drill including a swivel body, a boom, a kelly rope, a kelly bar 2 and the like. It is detachably attached via.

  The main body 11 of the bottomed bucket 1 is formed to have a diameter that can be inserted into the excavation hole 60 as shown in FIG. 6 (a) excavated by an excavation bucket (not shown). Is arranged.

  Further, the widened wings 12 and 12 are closed when the bottomed bucket 1 is lifted to form a part of the side surface of the cylindrical main body 11, and as shown in FIG. When inserted, it is opened and the wall surface of the excavation hole 60 is cut and widened.

  As shown in FIG. 2, the widened wing portion 12 is formed with a constant width portion 12a having a substantially constant width near the lower end thereof, and a triangular portion 12b having a tapered shape at the upper portion thereof. As shown in FIG. 4, it is formed in an arc shape in plan view.

  The uniform width portion 12a is formed to a height of, for example, about 500 mm, and a portion cut by the uniform width portion 12a becomes a bottom plate of an expanded pile having a thickness of about 500 mm.

  Further, as shown in FIG. 1, a plurality of roller bits 121,... Are provided at the side end portion of the widened wing portion 12 at intervals in the extending direction of the side end portion.

  As shown in FIG. 5A, the roller bit 121 is attached so that the bead-shaped bit portion 121a of the abacus rotates around a shaft 121b fixed to the side end portion.

  In addition, a plurality of fixed bits 122 having a smaller amount of lateral protrusion than the roller bit 121 are fixed between the roller bit 121 and the roller bit 121.

  That is, the roller bit 121 protrudes outward from the fixed bit 122, and the roller bit 121 comes into contact with the excavation wall surface 6 first to cut the ground into a groove shape.

  Further, since the roller bit 121 rotates around the shaft 121b, the generation of excessive stress can be suppressed by rotating when the roller bit 121 is in contact with the hard ground.

  The main body 11 is formed with a notch 11a that can accommodate the roller bits 121, ... and the fixed bits 122, ... when the widened wings 12, 12 are closed.

  And the lower end of the connection member 141 is being fixed to the inner surface below this widening blade part 12, and the widening blade part 12 opens and closes by the force which acts via the connection member 141.

  That is, the transmission shaft portion 14 to which the lower end of the kelly bar 2 of the earth drill is connected is housed in the main body portion 11 as shown in FIGS. 1 and 2, and the connecting member 141 is connected to the lower end of the transmission shaft portion 14. The upper ends of the two are connected to each other with a universal joint structure.

  In the present embodiment, the speed reduction device 3 is interposed between the transmission shaft portion 14 and the lower end of the Kelly bar 2, and the lower portion of the speed reduction device 3 and the upper end of the transmission shaft portion 14 are connected by the connecting flange 5. It is connected. The upper and lower portions of the flange 5 are reinforced by reinforcing plates 5a and 5b as shown in FIG.

  The speed reduction device 3 is a device that operates when a load is applied to the bottom expansion bucket 1 by rotation and increases torque by slowing the rotation of the bottom expansion bucket 1. That is, since the speed reduction and the increase in torque can be achieved by the number of gears combined in the reduction gear 3, so that the bottom expansion pile having a large diameter bottom expansion portion can be constructed even with a relatively small-sized earth drill. Become.

  Further, the transmission shaft portion 14 is accommodated in a cylindrical guide tube 15 whose upper end is opened, and is configured to be movable in the vertical direction (axial direction) of the main body portion 11.

  .. Are fixed to the upper and lower portions of the outer peripheral surface of the guide tube 15 by welding or the like, and the other side of the mounting plate 151 is fixed to the inner surface of the main body 11. Has been.

  In addition, oval slide grooves 152, 152 extend in the longitudinal direction of the guide cylinder 15 on the opposing peripheral surface portions of the guide cylinder 15, and are connected to the transmission shaft portion 14 from the slide grooves 152, 152. A connecting bar 142 as a connecting portion for connecting the member 141 is projected.

  As shown in FIG. 3 (cross section AA in FIG. 2), the connecting bar 142 is inserted into a reinforcing tube 14a fitted in a hole penetrating in a direction orthogonal to the axis near the lower end of the cylindrical tubular transmission shaft portion 14. Is done.

  Both ends of the connecting bar 142 are projected from the slide grooves 152, 152, and cylindrical reinforcing covers 142a, 142a are attached to the projected both ends, respectively.

  Then, when the kelly bar 2 is rotated in the R direction in FIG. 3, the rotational force is transmitted to the transmission shaft portion 14 via the reduction gear 3, so that the transmission shaft portion 14 rotates and is attached to the connecting bar 142 that rotates accordingly. The reinforcing cover 142a, 142a pushes and rotates the guide cylinder 15, and the main body 11 is rotated by the rotational force transmitted through the mounting plates 151, ... attached to the guide cylinder 15.

  The upper ends of connecting members 141 and 141 extending in opposite directions are fixed to the reinforcing covers 142a and 142a, respectively, so as to be freely bent.

  Further, the lower end of the connecting member 141 is connected to a fixing portion 141a attached to the inner side surface of the widened wing portion 12 so as to be bent as shown in FIG.

  When the bottomed bucket 1 configured in this manner is in a state in which the transmission shaft portion 14 is pulled up with respect to the main body portion 11 as indicated by a two-dot chain line in FIG. The connecting member 141 stands up and the widened wings 12 and 12 are closed.

  When the transmission shaft portion 14 moves downward from this state, the reinforcing cover 142a is lowered along the slide groove 152, and the upper and lower universal joints of the connecting member 141 are bent, so that the connecting member 141 is inclined and the widened blades are bent. The parts 12 and 12 are pushed out to the side and opened (see the solid and broken lines in FIG. 2).

  FIG. 4 is a plan view showing a state in which one widening blade 12 is opened and the other widening blade 12 is closed in order to explain the movement of the widening blades 12, 12. Will not be in such a state, and the widened wings 12 and 12 open and close simultaneously.

  As shown in FIG. 4, the widened wing portion 12 can form an annular widened portion having a width substantially the same as the diameter before widening, in other words, the maximum widened portion 120 having a diameter nearly three times larger.

  Further, a closing blade stopper 125 is provided inside the main body portion 11 so as not to enter the inside of the widening blade portion 12 when the widening blade portion 12 is closed. The widened wing part 12 is stopped at a predetermined position by contacting the inner peripheral surface near the part.

  Further, the lower end of the connecting member 141 is connected to the fixing portion 141a attached to the inner peripheral surface of the widened wing portion 12 so as to be freely bent. However, as shown in FIG. The extending direction of the connecting member 141 changes between when it is closed and when it is closed.

  Further, as shown in FIGS. 1 and 2, a projecting portion 13 is formed at the lower end of the main body portion 11 below the widened wing portions 12 and 12. For example, the protruding portion 13 having a height of about 200 to 600 mm is provided for the bottomed bucket 1 having a height of about 3 m.

  Further, a conical lid portion 131 is attached to the projecting portion 13 so as to be openable and closable. As shown in FIG. 7, the excavated sediment accumulated in the main body portion 11 is discharged by opening the lid portion 131.

  Next, the construction method of the expanded pile according to the present embodiment will be described and the operation thereof will be described.

  First, a drilling bucket (not shown) is attached to the lower end of the ground drill kelly bar 2 to construct a cylindrical drilling hole 60 as shown in FIG.

  Then, once the excavation bucket is lifted from the excavation hole 60 and removed from the kelly bar 2, the bottom expansion bucket 1 is attached to the lower end of the kelly bar 2 instead.

  In this state, the bottom expansion bucket 1 is lowered to the excavation hole 60, and the lower surface of the bottom expansion bucket 1 is brought into contact with the bottom of the excavation hole 60 to obtain the state shown in FIG.

  Subsequently, when the earth drill is driven to rotate the kelly bar 2, the bottom expansion bucket 1 starts rotating by the rotational force transmitted by being decelerated by the reduction gear 3. By interposing the speed reduction device 3, even when the resistance force against the rotation of the bottom expansion bucket 1 is large, it can be rotated with a small torque of the kelly bar 2.

  Moreover, since this reduction gear 3 can be accommodated in the inside of the main-body part 11, the height required in order to attach the bottom expansion bucket 1 to the kelly bar 2 can be made low, and it becomes a comparatively small-sized earth drill. Can also be attached.

  Thus, in the state where the bottom surface of the widened bucket 1 is brought into contact with the bottom of the excavation hole 60, the main body 11 of the widened bucket 1 does not fall any further. On the other hand, the transmission shaft portion 14 to which the weight of the Kelly bar 2 is transmitted is lowered along the guide tube 15.

  Then, when only the transmission shaft portion 14 is lowered in a state where the main body portion 11 is not lowered, the lower end of the connecting member 141 that is flexibly connected to the lower end thereof spreads outward, and the widened wing portions 12 and 12 are slightly opened. .

  A plurality of roller bits 121,... And fixed bits 122,... Are provided at the side ends of the widened wings 12, 12, and as shown in FIG. The excavation wall surface 6 is cut into a groove shape by... And the ground therebetween is scraped by the fixed bits 122.

  That is, since the roller bit 121 has an acute-angled shape toward the outside, it is easy to bite into hard ground, and when the ground soaked is too hard and has high resistance, it rotates to avoid generating excessive stress. Therefore, the bit part 121a is hardly damaged or worn out in a short time.

  Further, by cutting the ground into a groove shape in advance by the roller bits 121,..., The ground between the grooves is less likely to collapse because the upper and lower restraining forces become smaller, so the fixed bits 122,. It can be scraped off efficiently, and the load acting on the fixed bits 122,... Can be reduced.

  When the excavation wall surface 6 is cut, the widened blades 12 and 12 are more likely to spread outward, so that the bottomed bucket 1 rotates with the rotation of the kelly bar 2 and the widened blades 12 and 12 are gradually opened. As the degree increases, finally, a widened portion 60b in which a frustoconical shape is coupled onto a cylindrical shape as shown in FIG. 6B is formed.

  Further, when the widening wings 12 and 12 begin to open, the protruding portion 13 is embedded as shown in FIG. 6B and is restrained by the ground, so that the resistance during widening is reduced. Even if it becomes larger, the position of the lower end of the widened bucket 1 does not shift, and the left and right opening degrees of the widened wings 12 and 12 are equalized, so that an accurate shaped widened part 60b can be formed at an accurate position. .

  Such a widened pile can expand the widened part 60b to about 2000 mm with respect to the shaft part 60a of about 900 mm in diameter, for example.

  On the other hand, the excavated earth and sand generated during the widening excavation is collected inside the main body 11 by the rotating widening blades 12 and 12.

  When the kelly bar 2 is lifted, the transmission shaft portion 14 rises along the guide tube 15, the connecting member 141 connected to the transmission shaft portion 14 rises and the widened wing portions 12, 12 are closed.

  If the lifting of the kelly bar 2 is further continued in this state, the reinforcing cover 142a of the connecting bar 142 comes into contact with the upper end of the slide groove 152, and the main body 11 is lifted.

  In this way, when the bottomed bucket 1 containing the excavated earth and sand is moved to the dumping site and the lid 131 is opened as shown in FIG. 7, the excavated earth and sand are discharged from the bottomed bucket 1.

  Further, the excavation wall surface 6 cut by the roller bits 121,... And the fixed bit 122 may be uneven as shown in FIG. When it is desired to form, once the bottomed bucket 1 is pulled up, the excavating blade to which the roller bits 121,... Are fixed is removed from the attaching / detaching portion 124. Instead, a plate-shaped cutting plate blade as shown in FIG. The part 123 is fixed to the side end part of the widened wing part 12 through the attaching / detaching part 124.

  Then, the bottomed bucket 1 is inserted into the drilling hole 60 again to rotate the kelly bar 2 and the widened blades 12 and 12 are widened. 6 can be formed.

  In the excavation hole 60 excavated in this way, a reinforcing bar is inserted and concrete is placed to complete an expanded pile made of cast-in-place concrete.

  Hereinafter, Example 1 of the above-described embodiment will be described. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  FIG. 8 is a view showing a state in which the opening adjustment plate 7 is arranged on the upper surface of the guide cylinder 15 in order to adjust the descending amount of the transmission shaft portion 14.

  In other words, in the above-described embodiment, the reinforcing cover 142a of the connecting bar 142 is brought into contact with the lower end of the slide groove 152 to widen the widened wings 12 and 12 to the maximum extent. In some cases, it is not necessary to increase the width until the portion 120 is reached.

  Therefore, a plate-shaped opening degree adjustment plate 7 having a through hole larger than the diameter of the transmission shaft portion 14 can be arranged on the upper surface of the guide tube 15 so that the transmission shaft portion 14 can be adjusted so as not to be lowered too much. The amount of movement of the transmission shaft portion 14 can be adjusted by the height of the opening adjustment plate 7, and this height is adjusted by the height or number of sheets per sheet.

  Further, the opening adjusting plate 7 can be easily mounted from the side surface of the transmission shaft portion 14 by being divided in half and connected to be freely opened and closed by a hinge.

  In Example 1, the speed reducer 3 arranged in the above embodiment is not attached, and the lower end of the Kelly bar 2 is connected to the upper end of the transmission shaft portion 14 by the connecting flange 5.

  Further, reinforcing plates 5a,... Are attached to the lower surface of the connecting flange 5, and are reinforced so as not to be deformed even when they collide with the opening adjustment plate 7.

  When the transmission shaft portion 14 is lowered to a predetermined position, the lower surface of the connecting flange 5 comes into contact with the opening adjustment plate 7, and the transmission shaft portion 14 does not lower below that.

  When the lowering of the transmission shaft portion 14 stops in this way, the widened wing portions 12 and 12 also stop in a partially open state, and the desired size of the expanded bottom portion 60b can be maintained.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Hereinafter, Example 2 of the above-described embodiment will be described. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  In the second embodiment, as shown in FIG. 9, a case where a guide cylinder 15A having a slide groove 152A obliquely provided on the peripheral surface is used will be described.

  The guide tube 15A is a cylindrical tube member that is open at least at the top, and is fixed to the inner surface of the main body 11A via mounting plates 151A and 151B fixed to the upper and lower portions of the outer peripheral surface.

  Further, as shown in FIGS. 9A and 9B, a slide groove 152A inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide cylinder 15A. Here, FIG. 9A is a cross-sectional view taken along the line CC in FIG. 9B, and FIG. 9B is a side view seen from the direction BB in FIG. 9A.

  Cylindrical reinforcing pipes 153 and 153 are disposed and reinforced on both sides of the slide groove 152A.

  The guide tube 15A accommodates the transmission shaft portion 14 such that the reinforcing cover 142a of the connecting bar 142 provided at the lower end of the transmission shaft portion 14 protrudes from the slide groove 152A.

  When the transmission shaft portion 14 moves in the vertical direction while rotating, the protruding reinforcing cover 142a moves up and down while changing the direction. That is, as shown in FIG. 9B, the reinforcing cover 142a protrudes to the left in the drawing when it is in contact with the upper end of the slide groove 152A, and protrudes in the direction perpendicular to the paper surface when it is in contact with the lower end.

  By configuring the reinforcing cover 142a to be connected to the connecting member 141 in this manner so as to move up and down while rotating around the guide cylinder 15A, it is possible to cancel the torsion that occurs when the widened wings 12 and 12 are opened and closed. The widened wings 12 and 12 can be smoothly opened and closed without generating excessive stress on the connecting member 141 or the universal joint.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment or Example 1, and thus description thereof is omitted.

  Hereinafter, Example 3 of the above-described embodiment will be described. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  In the third embodiment, a case will be described in which the widened portion 60b is formed in the excavation hole 60 in which the shaft portion 60a having a diameter larger than that of the main body 11 is excavated.

  In this way, when the bottomed bucket 1 is inserted into the excavation hole 60 having a diameter larger than that of the main body part 11, a gap is opened between the main body part 11 and the wall surface of the excavation hole 60. Therefore, as shown in FIG. The stabilizer 4 and the lower stabilizer part 133 are projected over the upper and lower parts of the body so that the main body part 11 does not deviate from the center position when the floor is expanded.

  That is, in the upper stabilizer 4, the ¼ arc-shaped slide plate 4 a,... Is pushed out in the diameter direction, and fills the space between the main body 11 and the wall surface of the excavation hole 60. Further, as shown in FIG. 11, the lower stabilizer portion 133 is disposed in an annular shape on the outer periphery of the body portion 132 having the same diameter as the main body portion 11, and between the body portion 132 and the wall surface of the excavation hole 60. fill in.

  As described above, the protruding portion 13A of the third embodiment includes the cylindrical body portion 132, the annular lower stabilizer portion 133 disposed on the outer periphery thereof, and the conical lid portion 131 that closes the lower surface of the body portion 132. It is mainly composed by.

  The lower stabilizer 133 is formed by connecting four arc portions 133a,..., Which are, for example, 1/4 arc-shaped steel boxes, and the circumferential end of the arc portion 133a. Are formed with ridges 133b and ridges 133c extending in the diameter direction.

  Then, the protrusions 133b and the recesses 133c of the arc part 133a are inserted into the recesses 133c and the protrusions 133b of the arc parts 133a and 133a on both sides thereof, and the adjacent arcs by bolts 133e as shown in FIG. The parts 133a,... Are joined together.

  Further, as shown in FIG. 11, a convex portion 133d is formed at the approximate center of the inner peripheral surface of the arc portion 133a, and a concave portion 132a for fitting the convex portion 133d is formed on the outer peripheral surface of the body portion 132. (See FIG. 10).

  Then, the convex portion 133d is fitted into the concave portion 132a by bringing the inner peripheral surface of the arc portion 133a into contact with the outer peripheral surface of the body portion 132, and both are joined by a bolt 134 as shown in FIG.

  Thus, if the outer peripheral surface of the lower stabilizer part 133 is continuously formed in the same plane, when the widened wing parts 12 and 12 are opened by rotating the bottom widened bucket 1, the temporarily eccentric load is projected. Even if it acts on 13A, the lower stabilizer part 133 does not bite into the excavation wall surface 6, and it does not become a hindrance to rotation of the bottom expansion bucket 1. FIG.

  Further, the lower stabilizer portion 133 is firmly integrated by inserting the protrusion 133b into the recess 133c, and is also firmly integrated with the body portion 132 by fitting the protrusion 133d and the recess 132a. Yes.

  For this reason, when the bottom expansion bucket 1 is rotated, it sufficiently resists the shearing force generated between the body portion 132 and the lower stabilizer portion 133 and the shearing force generated between the arc portions 133a,. be able to.

  Since the resistance received from the ground when opening the widened wing parts 12 and 12 is larger in the lower part than in the upper part of the widened bucket 1, only the lower stabilizer part 133 has an annular configuration in the third embodiment. However, the present invention is not limited to this, and the upper stabilizer 4 can be configured in the same manner as the lower stabilizer portion 133.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment or other examples, and thus description thereof is omitted.

  The preferred embodiments and examples of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to the embodiments and examples, and does not depart from the gist of the present invention. A degree of design change is included in the present invention.

  For example, in the present embodiment, the roller bits 121,... Are provided above the widening wings 12, 12, but the present invention is not limited to this, and the roller bits 121,. If the ground to be excavated is soft, the adjustment can be performed by removing the upper roller bits 121.

  In the above embodiment, the arcuate plate-shaped widening wing part 12 has been described. However, the present invention is not limited to this, and the triangular part 12b may have a skeleton structure, for example. Further, the main body portion 11 only needs to be formed in a circular arc plate shape so as to close the space between the equal width portions 12a and 12a, and a triangular portion extending upward is omitted from that portion. Can be.

  In the above-described embodiment, the configuration in which the speed reduction device 3 is accommodated in the bottomed bucket 1 has been described. However, the present invention is not limited to this. For example, the speed reduction device 3 and the stabilizer 4 are integrally configured. It may be.

It is a perspective view explaining the schematic structure of the bottom expansion bucket of the best embodiment of this invention. It is a side view explaining the structure of an expanded bucket. It is AA sectional drawing of FIG. It is explanatory drawing for demonstrating the widening range of a widening wing | blade part. (A) is an enlarged detail drawing for demonstrating the excavation shape of a roller bit, (b) is an enlarged detail drawing for demonstrating the excavation shape of a cutting-plate blade part. (A) is explanatory drawing which showed the state which arranged the bottom expansion bucket in the excavation hole before widening, (b) is explanatory drawing which showed the state of the bottom expansion part and bottom expansion bucket at the time of widening. It is a perspective view explaining the soil discharging method of an expanded bucket. It is sectional drawing which showed the structure of the bottom expansion bucket which has arrange | positioned the opening degree adjustment plate of Example 1. FIG. It is a figure explaining the structure of the guide cylinder of Example 2, Comprising: (a) is CC sectional drawing of (b), (b) is the side view seen from the BB line direction of (a). . It is a perspective view explaining the schematic structure of the bottom expansion bucket which provided the lower stabilizer part of Example 3. FIG. It is the top view which looked at the structure of the protrusion part of Example 3 from the top.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Expanded bucket 11, 11A Main body part 12 Wide wing part 12a Equal width part 12b Triangular part 121 Roller bit 122 Fixed bit 123 Cutting plate blade part 124 Detachable part 13, 13A Protrusion part 133 Lower stabilizer part (stabilizer)
14 Transmission shaft part 142 Connection bar (connection part)
142a Reinforcing cover (connecting part)
141 Connecting member 15, 15A Guide tube 152, 152A Slide groove 2 Kelly bar 3 Deceleration device 60a Shaft 60b Expanding bottom 7 Opening adjustment plate

Claims (8)

A bottom expanding bucket for forming a bottom expanded portion having a diameter larger than that of a shaft portion in a portion to be a bottom portion of a pile,
A cylindrical main body, and a widened wing formed so as to be openable so as to increase the diameter of the main body,
A transmission shaft that receives a force from a ground drill kelly bar is disposed in the main body so as to be movable in the vertical direction of the main body, and is connected to the transmission shaft so as to be bent. Is connected to the widened wing portion, and the transmission shaft portion is slidably accommodated in a guide tube attached to the inside of the main body portion ,
A slide groove inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide tube, and a connecting portion between the transmission shaft portion and the connecting member is projected from the slide groove and is used as a guide for the guide tube. A bottom-up bucket characterized by moving the transmission shaft portion in the vertical direction . A bottom expanding bucket for forming a bottom expanded portion having a diameter larger than that of a shaft portion in a portion to be a bottom portion of a pile,
A cylindrical main body, and a widened wing formed so as to be openable so as to increase the diameter of the main body,
A transmission shaft that receives a force from a ground drill kelly bar is disposed in the main body so as to be movable in the vertical direction of the main body, and is connected to the transmission shaft so as to be bent. Is connected to the widened wing portion, and the transmission shaft portion is slidably accommodated in a guide tube attached to the inside of the main body portion ,
The bottom expansion bucket according to claim 1 , wherein an amount of downward movement of the transmission shaft portion is set by a height of an opening adjustment plate that is detachably attached to an upper end of the guide cylinder .   The bottom expansion bucket according to claim 1, wherein a protrusion is formed at a lower end of the main body below the widening wing.   The widened bucket according to claim 3, wherein an annular stabilizer for adjusting the diameter of the protruding portion is detachably provided. The bottom expansion bucket according to claim 1, wherein a downward movement amount of the transmission shaft portion is set by a height of an opening adjustment plate that is detachably attached to an upper end of the guide cylinder.   6. The widened bucket according to claim 1, wherein a speed reducer is interposed between a lower end of the kelly bar and the transmission shaft portion.   7. A plurality of rotatable roller bits are provided at a side end portion of the widened wing portion at intervals in the extending direction of the side end portion. Expanded bucket as described in 1. The widening wings, a width in the vicinity of the lower end is formed in a shape upwardly tapering than with equal width portion of the substantially constant is formed, the roller bits or plates on the side edge portion of the equal width portion The widened bucket according to any one of claims 1 to 7, wherein a cutting plate blade portion having a shape is fixed via an attaching / detaching portion .

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