JP6152274B2 - Expanded 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.

  There is known an expanded bottom bucket for constructing a cast-in-place concrete pile (an expanded pile) in which an expanded bottom portion that is larger than a shaft portion is provided in a portion that becomes a bottom portion of the pile (see Patent Documents 1-5 and the like).

  For example, the widened bucket disclosed in Patent Document 1 is a widened bucket connected to a Keriba, and includes an upper widened wing and a lower widened wing. The bottom expanded wing having a circular arc shape in plan view is connected to a scraper having a circular arc shape in plan view via a rotating shaft extending in the vertical direction, and the scraper is also connected to a fixed portion of the bottom expanded bucket via a rotating shaft extending in the vertical direction. It is connected.

  For this reason, in order to open the lower bottom expanded wing, it is necessary to rotate the scraper around the rotation axis on the fixed part side and rotate the lower expanded bottom wing around the other rotation axis. Therefore, in Patent Document 1, a hydraulic cylinder that expands and contracts in the horizontal direction is disposed at the bottom of the bottom expansion bucket in order to open and close the lower bottom expansion blade.

  On the other hand, the bottom-enlarged bucket disclosed in Patent Documents 2-5 receives the force from the kelly bar and is transmitted through the transmission shaft portion that moves in the vertical direction and the connecting member connected to the transmission shaft portion. The widening wing is opened and closed.

Japanese Patent No. 3129859 JP-A-60-55198 Japanese Patent No. 3607845 Japanese Patent No. 4699304 JP 2008-240270 A

  In order to simplify the configuration of the widened bucket, it is ideal that the widened blade portion can be opened and closed only by the force received from the Keriba as disclosed in Patent Documents 4 and 5.

  However, when a plurality of curved plates are connected to each other by a rotating shaft in order to make the widened wing part open widely, it is difficult to open the widened wing part only with the force received from the kelly bar. For this reason, it has been considered that a force by a driving device such as a hydraulic cylinder that expands and contracts in the horizontal direction as disclosed in Patent Document 1 is necessary separately.

  Therefore, an object of the present invention is to provide a widened bucket that can be opened and closed by a force received from a kelly bar even if it is a widened wing portion having a plurality of portions connected via a rotating shaft.

  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, the widened wing portion being attached to the main body portion via a rotating shaft, and a first wing portion thereof. A second wing portion connected to the wing portion via a rotating shaft, and the main body portion receives a force from a kelly bar of an earth drill and is movable in a vertical direction, and the transmission shaft portion And having a lower end connected to the second wing portion and a first regulating member for regulating an opening amount of the first wing portion.

  Here, the first restricting member may be a means for switching between connection and release of the first wing portion with respect to the main body portion. Moreover, the 2nd control member which controls the opening amount of the said 2nd wing | blade part can be provided in the boundary of the said 1st wing | blade part and the said 2nd wing | blade part.

  Furthermore, a third regulating member that regulates the opening amount of the second wing part by an amount different from that of the second regulating member may be provided at the boundary between the first wing part and the second wing part. Then, at least one of the second restriction member or the third restriction member is brought into contact when the plate members attached to the outer peripheral surfaces of the first wing portion and the second wing portion are at a predetermined angle. Thus, it can be a means for preventing further opening of the second wing portion.

  Moreover, it can also be set as the structure which has a 3rd wing | blade part attached via a rotating shaft between the said 1st wing | blade part and the said 2nd wing | blade part.

  Further, the transmission shaft portion is slidably accommodated in a guide tube attached to the inside of the main body portion, and a slide groove inclined in a direction intersecting the axial direction is formed on a peripheral surface of the guide tube. The connecting portion between the transmission shaft portion and the connecting member is projected from the slide groove, and the transmission shaft portion can be moved in the vertical direction using the connecting portion as a guide.

  The widened bucket of the present invention configured as described above is widened by a first wing part attached to the main body part via a rotating shaft and a second wing part connected to the first wing part via the rotating shaft. Wings are constructed. And while the 2nd wing | blade part is connected to the connection member to which the force from Keriba is transmitted, the 1st regulating member which regulates the opening amount of a 1st wing | blade part is provided.

  For this reason, at the initial stage of widening, for example, by controlling the opening amount by the first restricting member so that the first wing portion does not open, only the second wing portion having a short arm can be opened to cut the ground. Therefore, widening can be performed sufficiently with only the force received from Keriba.

  And if the connection of the 1st wing | blade part with respect to the main-body part by a 1st control member is cancelled | released after the width expansion by a 2nd wing | blade part, a wide wing | blade part can be opened largely from a 1st wing | blade part. Also at this time, since the resistance received from the ground is reduced due to the widening by the second wing portion, the widening can be sufficiently performed only by the force received from the Keriba even if the arm becomes long.

  Further, by providing a second regulating member that regulates the opening amount of the second wing part at the boundary between the first wing part and the second wing part, the second wing part is prevented from opening to an unintended angle. be able to.

  Furthermore, by providing a third restricting member that restricts the opening amount of the second wing part in an amount different from the second restricting member, only the second wing part in the initial widening stage is opened, and the second wing part and the second wing part The angle of the 2nd wing | blade part with respect to a 1st wing | blade part can be changed by the stage which opens both 1 wing | blade part.

  Moreover, by setting it as the structure which provides the 3rd wing | blade part attached via a rotating shaft between a 1st wing | blade part and a 2nd wing | blade part, it becomes possible to construct a bottom expansion pile with a larger bottom expansion ratio. .

  Furthermore, if the guide tube is provided with an oblique slide groove and the transmission shaft portion is moved up and down along the slide groove, the widened wing portion can be smoothly opened and closed.

It is a perspective view explaining the schematic structure of the bottom expansion bucket of 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 a figure for demonstrating the state which only the 2nd wing | blade part of a widening wing | blade part opens, (a) is explanatory drawing of a 2nd control member periphery, (b) is an explanatory view of a 3rd control member periphery. It is explanatory drawing for demonstrating the state which a widening wing | blade part opens from a 1st wing | 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 bucket when only a 2nd wing | blade part opened, (c) is It is explanatory drawing which showed the state of the bottom expansion part and bottom expansion bucket when both a 2nd wing | blade part and a 1st wing | blade part opened. 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.

  Hereinafter, embodiments of the present invention will be described 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 FIGS. 6 (b) and 6 (c). When it is inserted into the digging hole 60, it is opened and the wall surface of the digging hole 60 is cut to widen it.

  As shown in FIGS. 1, 2, 4, and 5, the widened wing portion 12 is an inner wing portion as a first wing portion that is attached to the main body portion 11 via first hinges 123,. 12b and an outer wing portion 12a as a second wing portion attached to the inner wing portion 12b via second hinges 124,.

  The inner wing portion 12b and the outer wing portion 12a are both curved plates formed in a trapezoidal shape as viewed from the side as shown in FIGS. 1 and 2 and in a circular arc shape in a plan view as shown in FIGS. .

  And the 1st hinge 123 and the 2nd hinge 124 are arrange | positioned in the position corresponded to the trapezoid base of the inner wing | blade part 12b and the outer wing | blade part 12a. That is, the first hinge 123 and the second hinge 124 are rotation axes that extend in the axial direction (vertical direction) of the Kelly bar 2.

  A plurality of first hinges 123 and second hinges 124 are arranged at intervals in the vertical direction. The number of installation and the installation interval of the first hinge 123 and the second hinge 124 can be arbitrarily set according to required strength.

  Furthermore, as shown in FIGS. 1 and 2, the side wing portions 12 b and the side wing portions 12 a that are the side end portions of the widened wing portion 12 are spaced apart in the extending direction of the side end portions as shown in FIGS. The acute angle bits 121,... And the fixed bits 122,.

  On the other hand, the main body 11 is formed with a notch 11a that can accommodate the acute angle bits 121,... And the fixed bits 122,.

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

  That is, the transmission shaft portion 14 connected to the lower end of the ground drill kelly bar 2 is accommodated 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 addition, the lower end of the Kelly bar 2 and the upper end of the transmission shaft portion 14 are connected via the connecting flange 5. And the upper part and lower part of the connection flange 5 are reinforced by the reinforcement board 5a as shown in FIG.

  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. One side of the mounting plate 151,... Is fixed to the upper and lower portions of the outer peripheral surface of the guide cylinder 15 by welding or the like, and the other side of the mounting plate 151,. It is fixed.

  Further, as shown in FIGS. 2 and 8, slide grooves 152, 152 that are inclined in a direction intersecting the axial direction are formed on the opposing peripheral surface portions of the guide cylinder 15. Reinforcing pipes 153 and 153 are disposed on both sides of the slide groove 152 as shown in FIG.

  Then, a connecting bar 142 as a connecting portion for connecting the transmission shaft portion 14 and the connecting member 141 protrudes from the slide grooves 152, 152. 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 protrude from the slide grooves 152, 152, and cylindrical reinforcing covers 142a, 142a are respectively attached to the protruding both ends.

  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 and the transmission shaft portion 14 rotates. Further, the reinforcing covers 142a and 142a attached to the connecting bar 142 that rotates along with the transmission shaft portion 14 pushes the guide tube 15 to rotate. As a result, the rotational force is transmitted to the main body 11 through the mounting plates 151 attached to the guide cylinder 15, and the main body 11 rotates.

  Here, 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 flexibly connected to a fixed portion 141a attached to the inner peripheral surface of the outer wing portion 12a of the widened wing portion 12 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. 2, the reinforcing cover 142a of the connecting bar 142 is provided with the slide groove 152. 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 descends obliquely 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, The widened wings 12 and 12 are pushed sideways and opened.

  As described above, the lower end of the connecting member 141 is flexibly connected to the fixed portion 141a attached to the inner peripheral surface of the outer wing portion 12a of the widened wing portion 12, but the widened wing portion 12 is opened. The extending direction of the connecting member 141 changes between when it is closed and when it is closed.

  Specifically, when the transmission shaft portion 14 moves in the vertical direction while rotating, the reinforcing cover 142a protruding from the slide groove 152 moves up and down while changing the direction. That is, as shown in FIG. 8, when the reinforcing cover 142a is in contact with the upper end of the slide groove 152, the reinforcing cover 142a protrudes to the left in the figure and changes its direction in the direction perpendicular to the paper surface as it goes downward.

  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 15, it is possible to cancel the twist generated 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.

  Next, FIGS. 4 and 5 are explanatory diagrams for explaining the movement of the widened wing parts 12 and 12. FIG. 4 shows an operation for opening only the outer wing portion 12a, and FIG. 5 shows an operation for opening both the outer wing portion 12a and the inner wing portion 12b together.

  First, in the initial stage of widening, only the outer wing 12a is opened as shown in FIGS. 4 (a) and 4 (b). That is, the first regulating member 31 is installed in order to regulate the opening amount of the inner wing part 12b in the initial stage of widening.

  As shown in FIGS. 1, 2, and 4, the first restricting member 31 protrudes in parallel with a guide pipe 31 a fixed to the lower end of the guide tube 15 and an outer peripheral surface of the guide pipe 31 a with an interval in the vertical direction. And a pair of flanges 31c, 31c, a blade-side flange 31d fixed to the inner peripheral surface of the inner blade portion 12b, and a pin 31e serving as a connection / release switching means.

  As shown in FIGS. 1 and 2, the first restricting member 31 is provided not only at the lower part of the inner wing part 12 b but also at the upper part. The first restricting member 31 provided at the upper part is provided with flanges 31c and 31c on the outer peripheral surface of the guide tube 15 instead of the guide pipe 31a. Is omitted.

  The guide pipe 31a is disposed directly below the guide tube 15 and has a height in the vicinity of the upper edge of the equal width portion formed in a band shape below the widening wing portions 12 and 12. Further, pin holes 31g and 31g through which the pin 31e is inserted are respectively provided in the pair of flanges 31c and 31c projecting outward from the outer peripheral surface of the guide pipe 31a (see FIG. 1).

  Further, a pin hole 31f is also provided in the blade side flange 31d that projects from the inner peripheral surface of the inner blade portion 12b toward the center of the main body portion 11. The blade-side flange 31d is accommodated between the pair of flanges 31c and 31c when the inner blade portion 12b is closed.

  And by inserting the pin 31e in a state where the projection positions of all the pin holes 31f, 31g, 31g coincide with each other, the inner wing part 12b can be connected to the main body part 11 as shown in FIG.

  On the other hand, when the pin 31e is removed, the connection between the inner wing portion 12b and the main body portion 11 is released as shown in FIG. That is, the first restricting member 31 can easily switch between connection and release by attaching and detaching the pin 31e.

  When the first restricting member 31 is connected, the inner wing 12b is slightly recessed inward as shown in FIGS. 4 (a) and 4 (b). Thus, by connecting the inner wing part 12b to the main body part 11 by the first restricting member 31, the rotation around the first hinge 123 is restricted, and the inner wing part 12b does not open.

  On the other hand, since the rotation of the second hinge 124 is not restricted by the first restriction member 31, the outer wing part 12 a can be freely opened and closed within the range restricted by the second restriction member 32. That is, since the connecting member 141 is connected to the outer wing part 12a, the force transmitted from the kelly bar 2 to the connecting member 141 is used only for opening and closing the outer wing part 12a.

  Here, as shown in FIGS. 1 and 2, the second regulating member 32 is attached above the boundary between the inner wing portion 12b and the outer wing portion 12a. The second regulating member 32 regulates the opening amount of the outer wing portion 12a as shown in FIG. Here, the opening amount when only the outer wing part 12a is opened is regulated.

  The second restricting member 32 is mainly configured by a fixing plate 32a attached to the outer wing portion 12a side and a fixing plate 32b attached to the inner wing portion 12b side. The fixed plates 32a and 32b are formed of, for example, a plate material such as a rectangular steel plate, and are joined to the outer peripheral surfaces of the outer wing portion 12a and the inner wing portion 12b by welding, bolts, or the like.

  As shown in FIG. 4A, the fixing plates 32a and 32b are respectively attached to positions that come into contact when the angle between the outer wing portion 12a and the inner wing portion 12b reaches a predetermined angle. That is, when the outer wing portion 12a is opened and reaches a predetermined angle, the edge projecting toward the inner wing portion 12b side of the fixing plate 32a of the outer wing portion 12a becomes the outer wing of the fixing plate 32b of the inner wing portion 12b. The outer wing part 12a does not open any more when it hits the edge projecting to the part 12a side.

  When the pin 31e is removed and the connection by the first restricting member 31 is released, as shown in FIG. 5, not only the outer wing part 12a but also the inner wing part 12b is transmitted by the force transmitted from the kelly bar 2 to the connecting member 141. Will also open and close. That is, since the outer wing 12a and the inner wing 12b are connected via the second hinge 124, if the first restricting member 31 is not connected to the main body 11 side, the outer wing 12a and the inner wing 12b are connected to each other. The wing part 12b moves in conjunction.

  Furthermore, below the boundary between the inner wing portion 12b and the outer wing portion 12a, as shown in FIGS. 1, 2, and 5, a third regulating member 33 for regulating the opening amount of the outer wing portion 12a is attached. The third restriction member 33 is attached when the connection by the first restriction member 31 is released, for example.

  As shown in FIGS. 2, 4 (b) and 5, the third restricting member 33 includes a fixed plate 33a attached to the inner wing portion 12b side, a restraining portion 33b attached to the outer wing portion 12a side, and a restricting plate 33c. And is composed mainly of.

  The fixed plate 33a is formed of a plate material such as a rectangular steel plate, and is joined to the outer peripheral surface of the inner wing portion 12b by welding, bolts, or the like. The restraining portion 33b is formed of, for example, a gate-shaped steel plate, and is joined to the outer peripheral surface of the outer wing portion 12a by welding, a bolt, or the like with the concave portion facing the fixing plate 33a.

  On the other hand, the restriction plate 33c is formed of a plate material such as a rectangular steel plate, and is fixed to the outer peripheral surface of the outer wing portion 12a by a bolt 33d or the like. By attaching the restricting plate 33c with the bolt 33d, it can be easily attached and detached. Further, since the restricting plate 33c is accommodated in the concave portion of the restraining portion 33b, the restricting plate 33c is not displaced only by being fixed by the bolt 33d.

  As shown in FIG. 5, the fixed plate 33 a and the regulating plate 33 c are respectively attached to positions that come into contact when the angle between the outer wing portion 12 a and the inner wing portion 12 b reaches a predetermined angle. That is, when the outer wing part 12a is opened and reaches a predetermined angle, the edge projecting to the inner wing part 12b side of the regulating plate 33c of the outer wing part 12a becomes the outer wing of the fixed plate 33a of the inner wing part 12b. The outer wing part 12a does not open any more when it hits the edge projecting to the part 12a side. Before the restriction plate 33c is attached, the opening amount of the outer wing portion 12a is further increased as shown in FIG. 4B.

  As shown in FIG. 5, the widened wing portion 12 that combines the inner wing portion 12b and the outer wing portion 12a can excavate a larger bottom portion 60b than the shaft portion 60a (FIG. 6C). reference). For example, it becomes possible to form the widened portion 60b having a bottom area of about 5 to 7 times the cross-sectional area of the shaft portion 60a.

  Moreover, the whole opening degree of the widening wing | blade part 12 can be adjusted. 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.

  That is, the widened wings 12 and 12 can be expanded to the maximum by bringing the reinforcing cover 142a of the connecting bar 142 into contact with the lower end of the slide groove 152. However, depending on the widened pile, the widened portion 60b is the maximum of the widened bucket 1. It may not be necessary to widen until.

  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. 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.

  By the way, even when the pin 31e is not connected, when the widened blade 12 enters the inside of the main body 11, the blade-side flange 31d contacts the outer peripheral surface of the guide pipe 31a to prevent further inward movement. Therefore, it is possible to prevent the widened wing portion 12 from entering the inside excessively.

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

  A conical lid 131 is attached to the projecting portion 13 so as to be freely opened and closed. As shown in FIG. 7, the excavated sediment accumulated in the main body 11 can be discharged by opening the lid 131. .

  Next, while explaining the construction method of the bottom expanded pile using the bottom expanded bucket 1 of this Embodiment, the effect | action is demonstrated.

  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.

  At this stage, the main body 11 and the inner wing 12b are connected to the bottom expansion bucket 1 by the upper and lower first restricting members 31 and 31. On the other hand, the restriction plate 33c of the third restriction member 33 is not yet attached. In this state, the bottom expansion bucket 1 is lowered to the excavation hole 60 and the bottom 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 transmitted rotational force. 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 of the main body portion 11 spreads outward, as shown in FIGS. 4 (a) and 4 (b). Thus, only the outer wings 12a and 12a of the widening wings 12 and 12 are slightly opened.

  A plurality of acute angle bits 121,... And fixed bits 122,... Are provided at the side ends of the outer wing parts 12a, 12a, and the wall surface of the excavation hole 60 is cut by these bits. It will be.

  In this way, at the initial stage of widening, the opening amount is restricted by the connection by the first restricting members 31, so that the inner wing parts 12b, 12b are not opened, so that only the outer wing parts 12a, 12a with short arms are restricted. It can be opened to cut the ground. That is, if the widening wings 12 and 12 are opened from the initial stage of widening with the first hinge 123 as an axis, the bending moment acting to increase the length of the arm becomes large and the bending becomes easy, and the ability to cut decreases. Will do. On the other hand, if only the outer wings 12a and 12a are opened with the second hinge 124 as an axis, the force received from the kelly bar 2 is efficiently transmitted to the bits (121 and 122) of the outer wings 12a and 12a. It can be cut even on hard ground.

  When the wall surface of the excavation hole 60 is cut, the outer wing portions 12a and 12a are further easily spread outward. Therefore, the bottom expansion bucket 1 rotates with the rotation of the kelly bar 2, and the outer wing portions 12a and 12a gradually. The opening of becomes larger. As a result, as shown in FIG. 6 (b), the outer wing portions 12a and 12a that are part of the expanded bottom portion 60b are widened. In addition, since the 2nd control member 32 is attached to the boundary of the inner wing | blade part 12b and the outer wing | blade part 12a, when the outer wing | blade part 12a opens large as shown to Fig.4 (a), it will be fixed board 32a, 32b. It is possible to prevent the edges of the outer wing portions 12a from contacting each other and the angle of the outer wing portion 12a with respect to the inner wing portion 12b from becoming a predetermined value or less.

  Further, when the outer wing parts 12a and 12a start to open, the protruding part 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 bottom expanding bucket 1 does not shift, and the left and right opening of the outer wing parts 12a, 12a can be equalized and widened with an accurate shape at an accurate position.

  On the other hand, the excavated earth and sand generated during the widening excavation is scraped up inside the main body 11 by the rotating outer wing parts 12a and 12a. 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 outer wing portions 12 a and 12 a 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.

  Such lifting of the bottomed bucket 1 for soil removal is repeated as necessary. Then, when the widening excavation by the outer wing parts 12a, 12a is almost completed and the transition to the widening excavation using the inner wing parts 12b, 12b is made, the pins 31e,. The connection by the 1st control member 31, ... is cancelled | released. Since the pin 31e of the first restricting member 31 is merely inserted into the pin holes 31f, 31g, 31g, it can be easily removed.

  Then, the restriction plates 33 c and 33 c of the third restriction member 33 are attached to the bottom expansion bucket 1. The restriction plate 33c can be fixed by inserting the bolt 33d with the position of the hole of the restriction plate 33c aligned with the bolt hole 33e of the recess of the restraining part 33b attached to the outer peripheral surface side of the outer wing part 12a. .

  The bottomed bucket 1 in such a state is lowered again to the excavation hole 60, and the lower surface of the widened bucket 1 is brought into contact with the bottom of the excavation hole 60 to rotate the kelly bar 2. Then, when the transmission shaft 14 that receives the force from the Kelly bar 2 is lowered and the lower end of the connecting member 141 spreads outward, the widened wings 12 and 12 are slightly moved around the first hinge 123 as shown in FIG. Will open.

  Here, since the third regulating member 33 is attached to the boundary between the inner wing portion 12b and the outer wing portion 12a, the angle of the outer wing portion 12a with respect to the inner wing portion 12b does not become a predetermined value or less. That is, before the third restricting member 33 is attached, it is opened as if the outer peripheral surface side of the outer wing portion 12a was raised in a direction approaching the outer peripheral surface side of the inner wing portion 12b as shown in FIG. 4 (b). On the other hand, if the 3rd control member 33 is attached, as shown in FIG. 5, the opening amount of the outer wing | blade part 12a of the direction approaching the inner wing | blade part 12b will be reduced.

  Thus, by providing the third regulating member 33 that regulates the opening amount of the outer wing part 12a at the boundary between the inner wing part 12b and the outer wing part 12a, the outer wing part 12a opens to an unintended angle. Can be prevented.

  In addition, after the widening by the outer wing parts 12a, 12a is finished, the connection by the first restriction members 31,... Is released, and the restriction plates 33c, 33c of the third restriction member 33 are attached instead. The widened wing parts 12 and 12 can be greatly opened from 12b and 12b.

  In short, if the widened wing part 12 is to be opened largely around the first hinge 123 from the initial stage of widening, the resistance of the ground is too large and the widened wing part 12 cannot be opened only by the force received from the kelly bar 2. . On the other hand, if the resistance received from the ground is reduced due to the widening by the outer wing part 12a, even if the arm becomes long as the entire widening wing part 12, it can be sufficiently widened only by the force received from the kelly bar 2. Will be able to do.

  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. If the widened wing part 12 can be composed of a plurality of wing parts (the outer wing part 12a and the inner wing part 12b) as in the bottomed bucket 1 of the present embodiment, the bottom expansion ratio (for example, (the bottom area of the bottom expanded part 60b) / ( The cross-sectional area of the shaft portion 60a)) can be further increased. As a result, it becomes possible to efficiently construct an expanded pile with a high bearing capacity.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

  For example, in the above-described embodiment, the curved plate-like widened wing part 12 has been described. However, the present invention is not limited to this. For example, the inner wing part 12b may have a skeleton structure. Furthermore, as for the main body 11, it is only necessary to form a portion that closes between the equal widths of the outer wings 12 a, 12 a in the shape of an arc plate, and above that, a triangular portion that has a framework structure or spreads upward Can be omitted.

  Further, in the above-described embodiment, the widened wing portion 12 constituted by the two curved plates of the outer wing portion 12a and the inner wing portion 12b has been described. A wide wing part can also be comprised with a face plate. For example, a third wing part can be provided between the outer wing part 12a and the inner wing part 12b via a rotating shaft. Furthermore, the third wing portion can be constituted by a plurality of curved plates.

  Moreover, in the said embodiment, although it was set as the structure which provides the 2nd control member 32 and the 3rd control member 33 in the boundary of the inner wing | blade part 12b and the outer wing | blade part 12a, it is not limited to this, 2nd The restriction member 32 or the third restriction member 33 may not be provided. Furthermore, although the fixing plates 32a, 32b, and 33a are welded and the restricting plate 33c is fixed by the bolt 33d, it is not limited to this, and any fixing means may be used.

  In the above-described embodiment, the case where the slide groove 152 is provided obliquely on the peripheral surface of the guide cylinder 15 is described. However, the present invention is not limited to this, and extends straight in the vertical direction in the same manner as the axial direction of the guide cylinder 15. An elliptical slide groove can also be used.

DESCRIPTION OF SYMBOLS 1 Expanded bucket 11 Main part 12 Widening wing part 12a Outer wing part (second wing part)
12b Inner wing (first wing)
123 First hinge (rotary shaft)
124 Second hinge (rotating shaft)
14 Transmission shaft portion 141 Connecting member 142 Connecting bar (connecting portion)
142a Reinforcing cover (connecting part)
15 Guide tube 152 Slide groove 2 Keriba 31 First restricting member 32 Second restricting members 32a and 32b Fixing plate (plate material)
33 Third restriction member 33a Fixing plate (plate material)
33c Restriction plate (plate material)
60a Shaft 60b Expanded bottom

Claims (5)

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,
The widened wing portion has a first wing portion attached to the main body portion via a rotating shaft, and a second wing portion connected to the first wing portion via a rotating shaft,
The main body is configured to receive a force from the ground drill kelly bar and move in the vertical direction, and to be connected to the transmission shaft so that the lower end is connected to the second wing. and the member, and a first regulating member for regulating the amount of opening of the first blade section possess,
A second restricting member for restricting an opening amount of the second wing portion is provided at a boundary between the first wing portion and the second wing portion;
A bottom expansion , wherein a third restricting member for restricting an opening amount of the second wing part by an amount different from the second restricting member is provided at a boundary between the first wing part and the second wing part. bucket. 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,
The widened wing portion has a first wing portion attached to the main body portion via a rotating shaft, and a second wing portion connected to the first wing portion via a rotating shaft,
The main body is configured to receive a force from a kelly bar of an earth drill and to be movable in the vertical direction, and to be coupled to the transmission shaft so as to be bent and to be connected to the second wing portion. A member, and a first regulating member that regulates an opening amount of the first wing part,
A second restricting member for restricting an opening amount of the second wing portion is provided at a boundary between the first wing portion and the second wing portion;
The second restricting member is brought into contact with each other when a predetermined angle is formed between the plate members attached to the outer peripheral surface side of the first wing portion and the second wing portion, so that the second wing portion is further increased. An expanded bottom bucket characterized by being means for preventing the opening of the bottom. The bottom expansion bucket according to claim 1 or 2 , wherein the first restricting member is means for switching between connection and release of the first wing portion with respect to the main body portion. At least one of the second restricting member or the third restricting member is brought into contact when the plate members attached to the outer peripheral surface sides of the first wing portion and the second wing portion are at a predetermined angle. The bottom expanding bucket according to claim 1 , wherein the bottom expanding bucket is means for preventing further opening of the second wing portion. The transmission shaft portion is slidably accommodated in a guide cylinder 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. The bottom expansion bucket according to any one of claims 1 to 4 , wherein the transmission shaft portion is moved in the vertical direction.