JPH0157229B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bucket-type rotary excavation device used in civil engineering and construction work, such as when constructing foundations (cast-in-place).

(Prior Art) The applicant first arranged a plurality of cutter units in the shape of a bottomed cylindrical bucket divided into a plurality of pieces around a rotating shaft, and each of these cutter units was arranged around a rotating shaft. A split bucket type rotary excavation device (Japanese Patent Publication No. 58-21079, Japanese Patent No. 1190290) was proposed, which is characterized by being movable in the radial direction, and the present invention is a further improvement of this device.

As shown in FIG. 9, when constructing a cast-in-place pile in the ground a, it is advantageous to enlarge the lower end c of the column b of the pile because the supporting force of the pile increases.

Currently, there is a reverse circulation method as a mechanical excavation method that makes it possible to construct this type of expanded bottom pile.
A hole is dug in the ground a using a rotary bit (not shown), etc. In this case, a stand pipe d is placed near the ground surface, and the hole is filled with bentonite or muddy water e to form the inner wall f of the drill hole. To prevent collapse, the rotary bit is rotated and pushed down, and the excavated earth and sand is discharged to the outside by backflow of circulating water.

(Problem to be solved by the invention) However, with this reverse construction method, the bottom g
When expanded, due to the nature of the excavating machine, the bottom surface h becomes an inverted conical shape as shown in FIGS. 9 and 10, and slime i is precipitated at the bottom as shown in FIG. Because of the remaining residue, even after concrete was poured to form the foundation pile, the support capacity of this bottom part was unreliable, which was a drawback.

The present invention was made to solve these problems, and it is easy to expand the bottom of a pile hole excavated with an earth drill, etc., the bottom surface is horizontal, there is no residual slime, and it is easy to use for dry excavation. The object of the present invention is to provide a split-bucket type rotary excavation rig that is capable of carrying out the following operations.

(Means for Solving the Problems) In order to achieve the above-mentioned object, in the present invention, the peripheral wall portion and the bottom plate portion of the hollow cylindrical bucket are partially cut out, and the peripheral wall portion equivalent to the notched portion is cut out. A movable cutter unit is formed by combining the movable cutter unit and the bottom plate, and is movable via a hinge provided between one side edge of the circumferential wall of the movable cutter unit and the circumferential wall of the bucket main body formed by the remainder of the bucket. The cutter unit is made movable with respect to the bucket main body, and the movable cutter unit is driven by a hydraulic cylinder provided inside the bucket, and a part of the bottom plate of the bucket main body is analyzed and attached to the bottom cover. At the same time, the bottom cover can be opened and closed via a hinge provided on the divided part, and a connecting part with a Kelly bar is provided on the upper part of the bucket main body, thereby constructing a divided bucket type rotary excavation device.

(Function) As described above, the device of the present invention rotates one side edge of the movable cutter unit, which is made up of a part of the peripheral wall and a part of the bottom plate of a hollow cylindrical bucket, with respect to the bucket main body. Since the bucket can be mounted freely and opened and closed using a hydraulic cylinder, the bucket is inserted into the bottom of the pile hole drilled with an earth drill, etc., and lowered while rotating through the Kelly bar. By pushing out the movable cutter unit with a hydraulic cylinder, an inverted cone-shaped expanded bottom part can be formed at the bottom of the pile hole. Moreover, the bottom is level and there is no residual slime. This bottom-expanding work can also be done by empty digging, making it easier to dispose of the excavated soil.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 8. In the figure, 1 is the ground, 2 is a crawler crane, 3 is its crawler, 4 is a swivel base mounted on the crawler 3 so that it can be rotated freely, 5 is a crane boom attached to the swivel base 4 so that it can be raised and lowered, and 6 is a crane boom 5. A Kelly bar is suspended from the tip so that it can be raised and lowered, 7 is a rotation drive device (hydraulic type) for the Kelly bar 6,
Reference numeral 8 denotes a connecting arm connecting this rotary drive device 7 and the rotating base 4, 9 a swivel guide rod provided between the upper part of the crane boom 5 and the rotary drive device 7 in parallel with the Kelly bar 6, and 10 a Kelly bar 6. A hydraulic swivel joint 10 is provided above the Kelly bar 6 to be rotatable relative to the kelly bar 6, and this joint 10 is slidable relative to the swivel guide rod 9 via its guide member 10a. 1
Reference numeral 1 denotes a hydraulic hose reel, and a hydraulic hose (not shown) wound around this reel 11 is connected to a hydraulic power supply source (not shown) provided on the swivel table 4 and connected to a kelly bar via a swivel joint 10. 6 is connected to a hydraulic cylinder which will be described later in the split bucket type rotary excavation apparatus A of the present invention.

Note that a drilling bucket (not shown) for an earth drill is attached to the lower end of the Kelly bar 6 shown in Figure 1.
It can also be installed. 12 is a pile hole made by drilling the ground 1 with the earth drill.

Next, the divided bucket type rotary excavation apparatus of the present invention will be explained with reference to FIGS. 2 to 8.

In this embodiment, a hollow cylindrical bucket 13 is formed by a top plate 13a, a peripheral wall 13b, and a bottom plate 13c, and the peripheral wall 13b and bottom plate 13c of the bucket 13 are partially cut out. , a peripheral wall portion 15a and a bottom plate portion 1 equivalent to this notch portion 14.
5b is integrally formed as a movable cutter unit 15, and this movable cutter unit 15
A peripheral wall portion 13b of the bucket main body 13 formed by one side edge of the peripheral wall portion 15a and the remainder of the bucket bag 13.
A hinge 16 is provided between the opposite side edges of the movable cutter unit 15, so that the movable cutter unit 15 can be freely rotated.

The set position, number, and shape of the notch 14 and the movable cutter unit 15 equivalent to the notch 14 are not limited, but as shown in this embodiment, the set number is two, and the set position is 180 degrees. It is preferable to provide them symmetrically in phase. Further, as for its shape, it is preferable that the vertical shape of the peripheral wall portion 15a is a rectangular shape, and the planar shape of the bottom plate portion 15b is a sector shape with a substantially intersecting angle of 90 degrees.

And the peripheral wall portion 1 of each movable cutter unit 15
Bits 17 are arranged on the other side edge of 5a and the edge of the bottom plate portion 15b adjacent thereto, and
A bit 17 is also arranged at the notch edge of the bottom plate portion 13c of the bucket main body 13 on the rotation direction side.

Further, a part of the bottom plate part 13c of the bucket main body 13 is divided into fan shapes having an intersection angle of about 60 degrees, and this divided part is connected to the remaining bottom plate part 13c by a hinge 19 as a bottom cover 18 which can be freely opened and closed. The opening/closing mechanism of this bottom cover 18 will be described later. Reference numeral 20 denotes a reinforcing column provided at the center of the bucket main body 13 to connect the bottom plate part 13c and the top plate part 13a.

Further, as shown in FIG. 7, the shaft cylinder 21 is provided to protrude downward from the top plate portion 13a of the bucket main body 13,
A lever pivot shaft 22 is provided at the lower end of this shaft cylinder 21, and an intermediate portion of a swing lever 23 is fitted onto this pivot shaft 22. A reinforcing member 24 is provided to connect the shaft tube 21 and the support column 20.

Also, the peripheral wall portion 15 of each movable cutter unit 15
A bracket 25 is provided protruding from the inner surface of the cutter unit 15, and the bracket 25 of one cutter unit 15 and one end of the swing lever 23 are connected by a long link 26, and the bracket 25 of the other cutter unit 15 is connected to the swing lever 25. The other end of the lever 23 is connected by a short link 27.

Also, the bucket main body 13 adjacent to the hinge 16 of the cutter unit 15 connected to the long link 16
A bracket 28 is provided protruding from the inner surface of the peripheral wall portion 13b, and the base of the hydraulic cylinder 29 is attached to the bracket 28.
The piston rod 29a of the hydraulic cylinder 29 is pivotally supported by a pin 30, and the tip of the piston rod 29a of the hydraulic cylinder 29 is
It is connected to the other end of the swing lever 23 via. 32 is a return spring fitted to the piston rod 29a. Note that 33 is a connecting pin at both ends of the links 26 and 27.

Further, 34 is a seat plate provided at the center of the upper surface of the top plate part 13a of the bucket main body 13, and 35 is this seat plate 3.
4 through a bolt 36 (see Figure 3), the lower end of the Kelly bar 6 is inserted into this square hole, and a connecting pin (not shown) is inserted into the pin hole 35a. This connects the Kelly bar 6 and the split bucket type rotary excavation device A of the present invention. Note that 35b is a seat plate portion of the connecting member 35, and 37 (see FIGS. 4 and 7) is a rib that is protruded from the center of the bottom surface of the bucket main body 13 and also serves as a bit.

FIG. 8 also shows the bottom cover 18 of the bucket main body 13.
This shows an example of an opening/closing mechanism, in which an upper support 39 is provided protruding inside the side wall portion 13b, and an intermediate port 40 is provided below the upper support 39, and an opening/closing mechanism that passes through these supports 39, 40 is shown. A rod 41 is provided at the lower end of the rod 41. The rod 41 has a rectangular planar shape, and slopes 42b and 42c are formed on the lower surface by cutting upwardly both sides of a ridgeline 42a that intersects at an angle of 30 degrees with respect to the longitudinal direction of the rod 41. The formed latching member 42 is fixed, the upper end of the rod 41 is bent into a crank shape to form a handle 43, and a spring 44 is attached to this handle 43 so that the latching member 42 is in a position where it latches the bottom plate 23. Force it so that it will.

In addition, a hole 18a is formed on the bottom lid 18, and a hollow cylinder 45 enclosing the hole 18a is fixedly provided on the bottom lid 18, and a lid plate 46 is attached to the upper end of the cylinder 45.
A rectangular square hole 47 through which the locking member 42 can be passed vertically through the cover plate 46.
, with the 30 degree diagonal line L set as the center line in the longitudinal direction.

Next, the operation of the apparatus of the present invention constructed as described above will be explained.

As shown in FIG. 1, once a pile hole 12 of a desired depth has been excavated in the ground 1 using an earth drill or the like, a split bucket rotary excavation device A of the present invention is used to expand the bottom of the hole. It is connected to the lower end of the Kelly bar 6 and suspended, and the hydraulic cylinder 29 is retracted as shown in FIG. When the hydraulic cylinder 29 reaches its shortest position, each movable cutter unit 15
As a result of the action of the swing lever 23 and the links 26 and 27, each rotates inward about the hinge 16 as a fulcrum as shown in FIG. The diameter of is the minimum.

A in FIG. 1 shows this state, and in this case, the bottom cover 18 may remain closed.

However, if the diameter of the fully closed lever bucket is made slightly smaller than the diameter of the pile hole 12 that has already been excavated, then by operating the crane, this rotary excavation device A can be moved into the pile hole 12 together with the kelly bar 6. can be submerged.

Therefore, stop the bucket at position A' in Figure 1, where you want to expand the bottom, and from this position,
If the rotary excavator of the present invention is rotated by the rotary drive device 7 via the Kelly bar 6, and the hydraulic cylinder 29 is extended while the rotary excavator is lowered by operating the crane, each movable cutter unit 15 As the mounting side of the bit 17 gradually moves outward and sinks as shown in FIG.
As shown by A'', the rotary drilling rig is fully open.

That is, when the hydraulic cylinder 29 changes from the contracted state shown in FIG. 5 to the extended state shown in FIG. 6, the swing lever 23 rotates counterclockwise in the figure.
Each movable cutter unit 15 moves in the direction of arrow B in FIG. 6 with the hinge 16 as a fulcrum via links 26 and 27
It rotates as shown in FIG. 6, and finally reaches the fully open state shown in FIG.

During that time, the rotary excavation device of the present invention is rotating in the direction shown by arrow C in FIG. Bit 17 excavates the earth and sand necessary for bottom expansion. For this reason, as shown in FIG. 1, a conical, clean, enlarged hole 48 is formed at the bottom of the pile hole 12.

When the bottom-expanding excavation is completed, the hydraulic cylinder 29 is contracted. When the hydraulic cylinder 29 is retracted from the state shown in FIG. 6 to the state shown in FIG. 5, each movable cutter unit 15 rotates inward as described above, and finally, as shown in FIG. Since the bucket is completely closed, excavated earth and sand are stored in the bucket. Therefore, in this state, the rotary excavation equipment A is lifted to the ground through the pile hole 12 by operating the crane, and the swivel platform 4 of the crane is rotated to position it on the platform of a dump truck (not shown) or the like. If the bottom cover 18 is opened, the earth and sand in the bucket will be discharged.

To open the bottom cover 18, use the handle 4 shown in FIG.
3 is attached to the spring 44 and rotated in the direction of arrow D in FIG. 8b. When the handle 43 rotates, the latch member 42 also rotates in the direction of arrow D via the rod 41, so that the latch member 42 is aligned with the square hole 47, and as a result, the bottom cover 18 is unlatched. Because,
The bottom cover 18 is opened by rotating about the hinge 19 in the direction of arrow E in FIG. 8a due to its own weight and the weight of the earth and sand.

To close the opened bottom lid 18, the bottom lid 18 can be pushed up by external force, or the bucket can be lowered to the ground, and the bottom lid 18 can be closed by the weight of the device. That is, when the bottom cover 18 is pushed up, the square hole 47 comes into contact with both slopes 42b and 42c on the lower surface of the hooking member 42, and when the bottom cover 18 is further pushed up strongly, the hooking member 42 springs due to the action of the slopes. 44, and when the locking member 42 and the square hole 47 are finally in the same phase, the square hole 47 passes through the locking member 42 and the bottom cover 18 is completely closed. The hanging member 42 passed through the square hole 47.
is automatically locked because it intersects the square hole 47 at an angle of 30 degrees as shown in FIG. 8b due to the action of the spring 44.

The above-mentioned operation completes one cycle of bottom-expanding excavation work using the apparatus of the present invention, but in practice, the above-mentioned operation may be repeated several times as necessary.

(Effects of the Invention) Since the present invention is as described above, according to the apparatus of the present invention, the work of expanding the bottom of a pile hole can be carried out effortlessly and easily, and the reliability of the supporting force of the pile is improved.

In addition, construction can be performed with or without water in the ground, and unlike conventional reverse construction methods, it does not require circulating fluids such as bentonite, so there is no risk of pollution caused by excavated soil. It also disappears. Therefore, the cost for pollution prevention is reduced, and since bucket excavation is used, the construction period can be shortened, so the present invention has an excellent effect of being economically advantageous.

In particular, in the device of the present invention, each movable cutter unit is rotatably attached to the bucket main body by a hinge, and the movable cutter unit can be opened and closed by a simple drive device consisting of a hydraulic cylinder, a swing lever, and a link. Therefore, the number of component parts of the entire device is reduced and the structure is simplified, making it easier to manufacture and lowering the price. In addition, the strength is increased, which results in fewer failures.

[Brief explanation of drawings]

Fig. 1 is an elevational view showing the working state of a crawler crane equipped with the device of the present invention, Fig. 2 is an elevational view showing the state of the device of the invention at its minimum diameter, Fig. 3 is a plan view thereof, and Fig. 4 The figure is a bottom view of FIG. 2, FIG. 5 is a plan view partially showing the state of the device of the present invention at its minimum diameter, and FIG. 6 is a partially cross-sectional view showing the state of the device of the present invention at its maximum diameter. 7 is an elevational view partially showing the state shown in FIG. 6, FIG. 8a is a partial elevational sectional view showing the opening/closing device of the bottom plate of the cutter unit, and FIG. , FIG. 9 is an elevational cross-sectional view of an expanded bottom pile according to the conventional construction method, and FIG. 10 is an elevational cross-sectional view for explaining the conventional reverse construction method. 1...Ground, 2...Crawler crane, 6...
Kelly bar, 7...Rotary drive device, 9...Swivel guide rod, 10...Hydraulic swivel joint, 11...Hydraulic hose reel, A...Divided bucket type rotary drilling device, 12...Pile hole, 13...
Bucket main body (baket), 13a...Top plate part,
13b...peripheral wall part, 13c...bottom plate part, 14...
Notch, 15...Movable cutter unit, 15a
... Peripheral wall part, 15b ... Bottom plate part, 16 ... Hinge, 17 ... Bit, 18 ... Bottom cover, 19 ... Hinge, 20 ... Support column, 21 ... Axis cylinder, 22 ... Pivot shaft, 23... Swing lever, 25... Bracket, 26... Long link, 27... Short link, 28... Bracket, 29... Hydraulic cylinder, 35... Connection member, 39... Upper support,
40...Intermediate support, 41...Opening/closing rod, 4
2...Latching member, 43...Handle, 44...Spring, 47...Square hole, 48...Enlarged hole.

Claims (1)

[Claims] 1 The circumferential wall and bottom plate of a hollow cylindrical bucket are partially cut out, the combined body of the circumferential wall and the bottom plate corresponding to the cutout is made into a movable cutter unit, and the circumferential wall of this movable cutter unit is The movable cutter unit is made movable relative to the bucket main body via a hinge provided between one side edge and the peripheral wall of the bucket main body formed by the remainder of the bucket, and a hydraulic cylinder provided inside the bucket The movable cutter unit can be driven by the movable cutter unit, a part of the bottom plate of the bucket main body is divided into a bottom lid, and the bottom lid can be freely opened and closed via a hinge provided in this divided part, and the bucket main body can be opened and closed. A split bucket type rotary excavation device characterized by having a connection part with a kelly bar on the top.