JP2012162875A - Bottom enlarging bucket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earth-drill bottom enlarging bucket for drilling the bottom of a pile construction vertical hole to form a bottom enlarged part with its lower portion enlarged in a tapered shape, while securing a great bottom enlarging rate even when the shaft diameter is relatively small.SOLUTION: The bottom enlarging bucket includes a first bottom enlarging blade 4 and a second bottom enlarging blade 5 linearly raised/sunk in the inward/outward direction of the bucket, the first bottom enlarging blade 4 and the second bottom enlarging blade 5 being linked with each other via an equalizer link. The equalizer link consists of center links 30, 31, a first link 32 and a second link 36. The first link 32 connects the center link 30 to the first bottom enlarging blade 4. The second link 36 connects the center link 31 to the second bottom enlarging blade 5. The second link 36 is longer than the first link 32. The turning radius of a connection part between the second bottom enlarging blade 5 and the center link 31 from a vertical axis 28 of the bucket center is larger than the turning radius of a connection part between the first bottom enlarging blade 4 and the center link 30. A scraper 6 is provided on the second bottom enlarging blade 5.

Description

  The present invention relates to a bottom expansion bucket that excavates a tapered bottom expansion portion at the bottom of a vertical hole excavated by an earth drill.

  An earth drill that drills a vertical hole for foundation pile construction, etc., attaches a shaft digging bucket to the lower end of the kelly bar, drills a vertical hole to a predetermined depth with this shaft digging bucket, and then attaches it to the kelly bar The bottom of the hole is expanded into a taper shape by exchanging with a bottom expansion bucket. This bottom expansion bucket is provided with a bottom expansion blade with excavation pawls opened and closed by a hydraulic cylinder on the side of the bucket, and the hydraulic cylinder expands and contracts by receiving pressure oil supplied from a base machine via a hydraulic hose. The bottom wing is opened and closed. Such an expanded bottom bucket is proposed by the present applicant in, for example, Patent Documents 1 and 2.

  The bearing capacity of the pile excavated and constructed by the expanded bottom bucket is proportional to the expanded diameter. Increasing the bottom expansion ratio (bottom diameter / shaft diameter) of the bottom expansion portion is advantageous in that it is possible to increase the supporting force and reduce the amount of concrete. Accordingly, the invention of Patent Document 1 divides the widened wing of the widened bucket into a plurality of stages in the height direction, and attaches each of the divided widened wings so as to be independently rotatable around the rotation axis. The rotation angle from the maximum bottom expanded state to the accommodated state in the bucket is set smaller than the rotation angle of the bottom expanded wing below the uppermost expanded bottom wing. If comprised in this way, in the accommodation state in a bat, it can prevent that the upper end of the uppermost bottom expanded wing contacts a frame of a bucket, and can increase a bottom expansion rate.

  In the invention described in Patent Document 2, a lower bottom wing and an upper bottom wing are rotatably attached to the left and right vertical axes of a bottom expansion bucket via a lower support arm and an upper support arm, respectively, and the upper bottom wing is a lower bottom wing. It is configured to be opened and closed by being rotated, and an auxiliary expanded base blade is provided on the uppermost support arm of the upper support arms, and a portion above the upper expanded blade is excavated by the auxiliary expanded blade. It is a thing. Thereby, when the shaft diameter is 130 cm or more, it becomes possible to obtain a double expansion rate.

JP 2000-213270 A JP 2009-114624 A

  The conventional bottomed bucket described above has a structure in which the bottomed wing moves in an arc shape around the vertical frame of the bucket frame and opens and closes. Therefore, there is a problem of interference between the frame and the bottomed wing when the bottomed wing is closed. For this reason, when the shaft diameter is 130 cm or more, there is a structural margin, and thus it is possible to obtain a product having a double bottom expansion rate. However, a type with a small shaft diameter, for example, a bottom expansion bucket of 120 cm or less, could not obtain a double expansion rate.

  In view of the above problems, an object of the present invention is to provide a widened bucket capable of obtaining a large bottom expansion rate not only when the shaft diameter is relatively large but also when the shaft diameter is relatively small.

The bottom expansion bucket of claim 1 is a bottom expansion bucket for an earth drill that excavates a bottom expansion portion whose lower portion is expanded in a tapered shape at the bottom of a vertical hole for pile construction.
A pair of first widened wings guided by guide means provided on the frame of the bucket and mounted so as to be able to project and retract in the bucket outer direction opposite to each other across the bucket center;
A pair of second bottom wings guided by guide means provided on each of the first bottom wings, and mounted so as to be able to project and retract in the bucket outward direction opposite to each other across the bucket center;
A center link that is mounted on the vertical axis provided at the center of the bucket so that the center is horizontally rotatable;
A first link connecting each of the first widened wings and a connecting portion at the same rotational radius on the opposite side across the longitudinal axis of the center link;
Each of the second widened wings and the center link, each of which is longer than the first link, and each connecting portion with the center link has the same rotation on the opposite side across the longitudinal axis. A second link which is in a moving radius position and has a turning radius from the longitudinal axis of the connecting portion larger than the turning radius of the connecting portion with the first link;
The first bottom expanded wing or the center link is driven, and the first bottom expanded wing and the second bottom expanded wing are interlocked in the bucket inside and outside by the center link, the first link, and the second link. A driving device that opens and closes;
A scraper that is attached rearward when viewed in the rotational direction during excavation of the second bottom expansion wing and guides the earth and sand excavated by the second bottom expansion wing into a bucket is provided.

The widened bucket according to claim 2 is the widened bucket according to claim 1,
The guide means provided on the first bottom expanded wing includes a guide rail provided on the top of the first bottom expanded wing, and is mounted on the upper portion of the second bottom expanded wing so as to be able to roll along the guide rail. A roller is provided.

The widened bucket according to claim 3 is the widened bucket according to claim 1 or 2,
A guide groove is provided at a lower portion of the frame, and a drilling reaction force receiver that slides along the guide groove is provided at a lower portion of the first bottom wing,
The first bottom expanded wing is provided with a digging reaction force receiver that slidably holds the second bottom expanded wing between the first bottom expanded wing and the first bottom expanded wing.

  According to the first aspect of the present invention, there is provided a two-stage widening wing of a first widening wing and a second widening wing mounted so as to be movable inward and outward of the bucket and mutually movable, A first widened wing connected by a first link and a second link longer than the first link at a radial position longer than the first link of the same center link or a different center link. Therefore, even if the second bottom expansion blade has a larger amount of movement of the bottom expansion blade relative to the center link rotation angle than the first bottom expansion blade, and a hydraulic cylinder is used as a drive device for opening and closing the bottom expansion blade. A large enlarged diameter can be obtained with respect to the cylinder stroke.

  In addition, since the bottom wings move linearly in the bucket direction parallel to the frame, the problem that the bottom wings interfere with the frame when the bottom wings are closed is solved. In addition, it is possible to provide a bottom expansion bucket having a large bottom expansion rate.

  In addition, since the bottom expansion wing linearly moves in and out of the bucket, the excavation claw attached to the second bottom expansion wing can be set so as to be in contact with the excavation surface at the same angle, enabling efficient excavation. Become.

  According to invention of Claim 2, a guide rail is provided as a guide means which guides a 2nd bottom expansion blade with respect to a 1st bottom expansion blade, and it rolls on this guide rail on the upper part of a 2nd bottom expansion blade. By providing the roller, the second bottom expanded wing is supported in a so-called hanging manner, so that the influence of the excavated earth and sand is less affected, and the second bottom expanded wing can be easily moved. Further, the wear on the bottom surface of the second bottom expanded wing 5 can also be reduced.

  According to a third aspect of the present invention, a guide groove is provided at a lower portion of the frame, a drilling reaction force receiver that slides along the guide groove is provided at a lower portion of the first bottom expanded blade, and the first bottom expanded Since the wing is provided with the excavation reaction force receiver that comes into contact with the back surface of the second bottom expansion wing, the first bottom expansion wing and the second bottom expansion wing are prevented from being deformed during excavation, and the excavation accuracy is maintained.

It is a front view which shows one Embodiment of the bottom expansion bucket by this invention in the state which the bottom expansion blade closed. It is a side view of FIG. It is a front view shown in the state where the bottom expansion bucket of this embodiment was opened. It is a front view which shows the frame of the bottom expansion bucket of this embodiment. It is an AA expanded sectional view of FIG. It is a front view which shows the 1st bottom expansion wing | blade of this embodiment. It is a front view which shows the 2nd bottom expansion wing | blade of this embodiment. It is a side view which shows the attachment structure with respect to the flame | frame of the 1st bottom expansion wing | blade of this embodiment. It is BB expanded sectional drawing of FIG. It is a side view which shows the attachment structure of the 2nd bottom wing with respect to the 1st bottom wing of this embodiment. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG. It is EE sectional drawing of FIG. It is a top view which shows the inclination angle with respect to the excavation surface of the excavation nail of this embodiment.

  1 is a front view showing an embodiment of a bottom expansion bucket according to the present invention with a bottom expansion blade closed, FIG. 2 is a side view thereof, and FIG. 3 is a front view showing a state in which the bottom expansion blade of the bottom expansion bucket is opened. . 1 to 3, reference numeral 1 denotes a bucket frame, and a stabilizer 2 is attached to a cylindrical portion 1a at the upper end thereof. The stabilizer 2 is inserted into a lower portion of a shaft hole (not shown) excavated by a shaft digging bucket (not shown) to stabilize the axial center position of the bottom expansion bucket. Connected to the center of the stabilizer 2 is a kelly bar (not shown) that supports the widened bucket and rotates, inserts it into a vertical hole, and pulls it up.

  As shown in the front view of FIG. 4, the frame 1 of this embodiment includes a top plate portion 1b welded to the lower portion of the cylindrical portion 1a and two plate-like portions welded to the lower portion of the top plate portion 1b. 1c, 1c, a horizontal frame 1d welded to the lower ends of these plate-like portions 1c, 1c, vertical frames 1e, 1e welded to the lower surface of the horizontal frame 1d, and welded to the lower ends of these vertical frames 1e, 1e The horizontal frame 1f, the left and right vertical frames 1g, 1g which are protruded downward from both ends of the horizontal frame 1f and welded, and both ends are welded to the left and right vertical frames 1g, 1g, and are vertically It consists of three horizontal frames 1h, 1i, 1j provided at intervals.

  FIG. 5 is a cross-sectional view taken along the line AA of FIG. 1. As shown in FIGS. 4 and 5, arc-shaped body portions 3 and 3 are attached to the lower portions of the vertical frames 1g and 1g, respectively, by welding or the like. An opening 7 is formed between the body portions 3 and 3. These openings 7 allow the lower portions of the first bottom wing 4 and the second bottom wing 5 to be linked by an equalizer link described later, and the scraper 6 fixedly attached to the second bottom wing 5 to enter and exit. It is. A bottom lid 8 is attached to the body parts 3 and 3 so as to be openable and closable by a known structure. Reference numeral 9 denotes a slime introduction lid mounted on the upper surface of the bottom lid 8 so as to be openable and closable by a hinge 10. Is.

  6 is a front view showing the first bottom wing 4, FIG. 7 is a front view showing the second bottom wing 5, and FIG. 8 is a side view showing an attachment structure of the first bottom wing 4 to the frame 1. As shown in FIGS. 4 and 8, two guide rails 11 and 11 are fixed on the horizontal frame 1i. On the other hand, as shown in FIG. 6, a plurality of rollers 12 are attached side by side to the middle portion of the first bottom wing 4, and these rollers 12 can roll on the guide rail 11 as shown in FIG. 8. By mounting, the pair of first bottom widening blades 4 and 4 are mounted so as to be movable in and out of the bucket so that the frame 1 is sandwiched between the two first bottom widening blades 4 and 4.

  In addition, a guide groove 13 is formed on the lower surface of the lowermost horizontal frame 1j, and an L-shaped locking portion 14 that is slidably fitted in the guide groove 13 is provided on the first bottom expanded wings 4 and 4. Thus, the roller 12 is prevented from being detached from the guide rail 11 and the excavation reaction force generated in the direction indicated by the arrow F during excavation is received by the frame 1 by the engagement of the locking portion 14 and the guide groove 13. .

  9 is a cross-sectional view taken along the line BB in FIG. 1 to 3 and 9, reference numeral 16 denotes a hydraulic cylinder that moves the first widened blade 4 in and out of the bucket. The hydraulic cylinder 16 has one end connected to a bracket 17 (see FIG. 4) provided in the horizontal frame 1i by a pin 18, and the other end to a pin hole 19 (see FIG. 6) provided in the first bottom blade 4. It connects with the pin 20 to insert.

  In FIG. 6, reference numeral 4a denotes a notch provided in the plate surface 4b of the first bottom wing 4 for passing through center links 30 and 31 of an equalizer link described later, and reference numeral 21 denotes a first link 32 of an equalizer link described later. It is a bracket to do. Reference numeral 22 denotes an excavation reaction force receiver that movably holds the second bottom expansion blade 5 between the plate surface 4b of the first bottom expansion blade 4 (see FIG. 9).

  As shown in FIG. 7, among the outer edges (edges protruding to the outside of the bucket) of the second bottom expanded wing 5, the lower outer edge 5a is formed vertically, and the upper outer edge 5b is formed inclined. These outer edges 5a, 5b are provided with excavation claws 23 for excavating the expanded bottom portion.

  As shown in FIG. 6, a guide rail 24 is provided on the top of the first bottom wing 4, while a plurality of rollers 25 are attached side by side on the top of the second bottom wing 5 as shown in FIG. 7. As shown in the side view of FIG. 10, the roller 25 is mounted on the guide rail 24 so as to be able to roll, and the second bottom blade 5 is attached to the first bottom blade 4 so as to be movable in and out of the bucket. To do.

  In FIG. 5, R indicates the rotation direction of the bucket during excavation. As shown in FIG. 5 and FIG. 7, a scraper 6 for introducing excavated earth and sand into the bucket is provided on the rear side (back side) of the second bottom expanded blade 5 as viewed in the bucket rotation direction, and one end of the scraper 6 is second It is fixed to the outer edge 5a side of the expanded wing 5 by being fixed by welding or a fixture. Then, a gap g for passing excavated earth and sand is formed between the portion other than the fixed portion of the scraper 6 to the second bottom expanded blade 5 and the second bottom expanded blade 5. An opening 5c for passing excavated earth and sand to the scraper 6 side is provided at the lower part of the second bottom expanded wing 5. As shown in FIG. 7, a notch 5d for passing center links 30 and 31 of an equalizer link described later is provided in an intermediate portion of the second bottom expanded wing 5, and an equalizer described later is provided in the vicinity of the notch 5d. A bracket 26 for connecting the second link 36 of the link is provided.

  Next, an equalizer link for interlocking the first bottom expanded blade 4 and the second bottom expanded blade 5 will be described. As shown in FIGS. 2 and 4, a vertical axis 28 is fixed to pass through a position corresponding to the center of the bucket in the horizontal frames 1 f and 1 h, and a boss 29 is rotatably fitted to the vertical axis 28. FIG. 11 is a cross-sectional view taken along the line CC of FIG. As shown in FIGS. 2 and 11, the center portion of the first center link 30 is fixed to the upper portion of the boss 29 by welding or the like. The center portion of the second center link 31 is fixed to the lower portion of the boss 29 by welding or the like. As shown in FIG. 11, the second center link 31 is formed longer than the first center link 30.

  As shown in FIGS. 2 and 11, the first link 32 and the pins 33 and 34 are provided between both ends of the first center link 30 and the brackets 21 and 21 provided on the first expanded wings 4 and 4. Link. Further, the second link 36 and the pins 37 and 38 are connected between the second center link 31 and the brackets 26 and 26 provided on the second bottom expanded blade 5. Here, the second link 36 is formed longer than the first link 32.

  As shown in FIGS. 9 and 11, the pair of first bottom expanded blades 4, 4 have the same distance from the longitudinal axis 28 of the connecting portion with the first center link 30, that is, their turning radii. No. 1 expanded wings 4 and 4 are always in symmetrical positions about the longitudinal axis 28. Further, the pair of second bottom wings 5 and 5 have the same distance from the longitudinal axis 28 of the connecting portion with the second center link 31, that is, the turning radius is equal. The vertical axis 28 is always in a symmetrical position.

  5 and 9 show a state where the hydraulic cylinder 16 is most contracted. When the hydraulic cylinder 16 is extended from this state, in FIG. 11, the first bottom expanded wing 4 moves in the direction indicated by the arrow G, that is, toward the outside of the bucket. The first center link 30 rotates in the direction indicated by the arrow r along with the movement of the first bottom expanded wing 4, and the first center link 30 and the boss 29 are integrally coupled together. The center link 31 also rotates in the direction of the arrow r. As a result, the second bottom expanded wing 5 connected by the second center link 31 and the second link 36 also moves in the arrow G direction.

  Here, the second link 36 is longer than the first link 32, and the distance (turning radius) between the pin 37 connecting the second link 36 to the second center link 31 and the vertical axis 28. Is longer than the distance (turning radius) between the pin 33 connecting the first link 32 to the first center link 30 and the longitudinal axis 28, the second widening blade 5 is the first widening blade 4. The amount of movement becomes larger than that, and with the movement of the first bottom expansion blade 4, the second bottom expansion blade 5 moves relative to the first bottom expansion blade 4, and the excavation claw of the second bottom expansion blade 5 23 bites into the inner wall of the expanded bottom, and excavation is performed. FIG. 12 is a cross-sectional view taken along the line DD in FIG.

  During the excavation, as shown in FIG. 9, the second bottom expanded wing 5 comes into contact with the back side by the excavation reaction force receiver 22 provided on the first bottom expanded wing 4, so that the second bottom expanded wing 5 is deformed. Excavation can be performed in a prevented state. FIG. 13 is a cross-sectional view taken along the line EE of FIG. 3. When excavation is performed by rotating the bucket in the direction indicated by the arrow R, the earth and sand excavated by the excavation claw 23 is transferred to the second bottom wing 5. It moves to the scraper 6 side from the provided opening 5c, is guided by the scraper 6 as indicated by arrows m and n, and is introduced into the bucket. Even when the hydraulic cylinder 10 is contracted and the second bottom expanded blade 5 is closed while rotating the bucket in the direction indicated by the arrow R, the earth and sand moves from the opening 5c to the scraper 6 side, and the bucket of the scraper 6 (body portion) 3) The excavated earth and sand is also accommodated in the bucket as it moves in.

  As shown in FIG. 5, according to this embodiment, when the excavation radius φ1 is 100 cm when the second bottom expanded wing 5 is most contracted, the second bottom expanded wing 5 is shown in FIG. The excavation radius φ2 in the most open state can be set to 200 cm or more, and a bottom expansion rate of twice or more can be obtained.

  As described above, in this embodiment, the two-stage structure including the pair of first bottom wings 4 and the pair of second bottom wings 5 mounted so as to be movable inward and outward of the bucket and movable relative to each other. A second center link 31 that is longer than the first center link 30, the first center link 30 is connected to the first center link 30 by a first link 32, and the first center link 30 is connected to the first center link 30. Since the second bottom expansion blade 5 is connected by the second link 36 longer than the link 32 of the first bottom expansion blade 5, the second bottom expansion blade 5 can take a larger amount of movement of the bottom expansion blade with respect to the center link rotation angle than the first bottom expansion blade 4. A large enlarged diameter can be obtained with respect to the stroke of the hydraulic cylinder 16 that opens and closes the first bottom expanded blade 4, and an enlarged diameter larger than that of the conventional bottom expanded bucket can be obtained.

  In this embodiment, since the widened wings 4 and 5 move linearly in the bucket in and out parallel to the frame 1, the widened wings 4 and 5 are moved to the frame when the widened wings 4 and 5 are closed. The problem of interfering with 1 is solved, and it is possible to provide a bottom expansion bucket having a large bottom expansion rate even with a small bucket.

  Further, in this embodiment, since the widened wings 4 and 5 move linearly in the bucket inner and outer directions in parallel to the frame 1, as shown in FIG. The rake angle α and clearance angle β of the excavation claw 23 attached to the bottom expansion blade 5 can be excavated in a constant state regardless of the progress of the excavation, that is, the degree of protrusion of the second bottom expansion blade 5 from the bucket. , Efficient drilling is possible.

  Further, according to this embodiment, the guide means for guiding the second bottom wing 5 with respect to the first bottom wing 4 is constituted by the guide rail 24 provided on the top of the first bottom wing 4, Since the roller 25 that rolls on the guide rail 24 is provided on the second bottom expanded wing 5, the second bottom expanded wing 5 is supported in a so-called suspended manner, and is less affected by the resistance of excavated earth and sand. The movement of the wing 5 is facilitated. Further, the wear on the bottom surface of the second bottom expanded wing 5 can also be reduced.

  In the above embodiment, the center link that constitutes the equalizer link is configured by a separate member including the first center link 30 and the second center link 31, but this may be configured as a single center link. Good. However, if the center link is constituted by the two center links 30 and 31 as in the above embodiment, there is no problem of interference between the first link 32 and the second link 36, and the design of the equalizer link There is an advantage that the configuration becomes easy.

  Even when the center link is constituted by one, the second link 36 is determined by the distance from the longitudinal axis 28 of the connecting portion (pin 33) of the first link 32 to the center link, that is, the turning radius. The turning radius from the vertical axis 28 of the connecting portion (pin 37) to the center link is set large.

  The hydraulic cylinder 16 that opens and closes the expanded bottom blades 4 and 5 may be mounted between the frame 1 and the center link 30 or 31 instead of being mounted between the frame 1 and the first expanded bottom blade 4. In addition, a hydraulic motor or an electric motor may be used as a driving device that opens and closes the bottom expanded blades 4 and 5.

  In addition, when implementing this invention, in addition to what was shown in the said embodiment, a various change and addition are possible in the range which does not deviate from the summary of this invention.

  1: frame, 2: stabilizer, 3: trunk, 4: first bottom wing, 5: second bottom wing, 5c: opening, 6: scraper, 7: opening, 8: bottom lid, 11: Guide rail, 12: roller, 13: guide groove, 14: locking portion, 16: hydraulic cylinder, 17: bracket, 18: pin, 19: pin hole, 20: pin, 21: bracket, 22: receiving excavation reaction force , 23: excavation claw, 24: guide rail, 25: roller, 26: bracket, 28: vertical axis, 29: boss, 30: first center link, 31: second center link, 32: first link , 33, 34: Pin, 36: Second link, 37, 38: Pin, 40: Excavation surface

Claims (3)

In the bottom drilling bucket for earth drills that excavates the bottom expansion part where the lower part is expanded in a tapered shape at the bottom of the vertical hole for pile construction,
A pair of first widened wings guided by guide means provided on the frame of the bucket and mounted so as to be able to project and retract in the bucket outer direction opposite to each other across the bucket center;
A pair of second bottom wings guided by guide means provided on each of the first bottom wings, and mounted so as to be able to project and retract in the bucket outward direction opposite to each other across the bucket center;
A center link that is mounted on the vertical axis provided at the center of the bucket so that the center is horizontally rotatable;
A first link connecting each of the first widened wings and a connecting portion at the same rotational radius on the opposite side across the longitudinal axis of the center link;
Each of the second widened wings and the center link, each of which is longer than the first link, and each connecting portion with the center link has the same rotation on the opposite side across the longitudinal axis. A second link which is in a moving radius position and has a turning radius from the longitudinal axis of the connecting portion larger than the turning radius of the connecting portion with the first link;
The first bottom expanded wing or the center link is driven, and the first bottom expanded wing and the second bottom expanded wing are interlocked in the bucket inside and outside by the center link, the first link, and the second link. A driving device that opens and closes;
A bottom expansion bucket comprising: a scraper that is attached rearward when viewed in a rotation direction during excavation of the second bottom expansion wing and guides the earth and sand excavated by the second bottom expansion wing into the bucket. The widened bucket according to claim 1,
The guide means provided on the first bottom expanded wing includes a guide rail provided on the top of the first bottom expanded wing, and is mounted on the upper portion of the second bottom expanded wing so as to be able to roll along the guide rail. An expanded bottom bucket characterized by having a roller. The widened bucket according to claim 1 or 2,
A guide groove is provided at a lower portion of the frame, and a drilling reaction force receiver that slides along the guide groove is provided at a lower portion of the first bottom wing,
A bottom expansion bucket, wherein the first bottom expansion wing is provided with an excavation reaction force receiver that slidably holds the second bottom expansion wing between the first bottom expansion wing and the first bottom expansion wing.

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