JPH0233833B2 - KAKUTEIKUTSUSAKUBAKETSUTO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bottom-expanding excavation bucket in pile hole excavation, which is generally referred to as dry excavation, such as the earth drilling method.

BACKGROUND TECHNOLOGY For example, in the earth drilling method, generally a kelly bar 4 is suspended via a rope 3 from the tip of a boom 2 rising from a crane body 1, as shown in FIG. A drive device 7 attached to the front of the crane body 1 via an arm 6 rotates the Kelly bar 4, and excavates a pile hole 8 while giving thrust to the bucket 5 which rotates together with the Kelly bar 4. It is something to do.

The bucket 5 has an excavating cutting edge fixed to the bottom plate that opens and closes the bottom of the cylindrical part, and as the bucket 5 rotates, the excavating cutting edge takes in earth and sand into the bucket 5 while digging a pile hole, and lifts the bucket 5. Move above the loading platform of the dump truck, open the bottom plate of the bucket 5, remove the soil, and drop the earth and sand onto the loading platform.

Problems to be solved by the invention By the way, the force with which a pile supports a structure (= bearing capacity)
is related to the cross-sectional area of the supporting ground of the pile, so for foundation piles, a method of enlarging the lower part was conventionally considered, but in dry excavation methods such as the earth drill method, the bucket 5 mentioned above The bottom-expanding excavation equipment also required a mechanism to perform bottom-expanding excavation and a function to take in and remove soil, and it was not possible to incorporate a simple mechanism into the bucket.

The present invention was proposed to solve the above-mentioned conventional problems, and is particularly an improvement on the applicant's earlier application, Patent Application No. 164393 filed in 1982.

Means and Effects for Solving the Problems The wide-bottom excavation bucket according to the present invention has an outer pipe having a spline hole disposed in the center of the bucket main body having a bottom plate that can be freely opened and closed, and an outer pipe having a spline hole disposed through a support frame. A slide guide rail is fixedly provided on the outer surface of the pipe at a required angle with respect to the axis, and a wing expansion bit that can be moved up and down is installed through an opening provided on the outer periphery of the bucket main body. , an earth and sand intake wall formed by a curved back surface, a bottom surface, and a curved outer surface to facilitate taking in excavated soil, and an excavation cutting edge provided along the edge of the bottom surface and along the edge of the outer surface. A rotary lid is provided for opening and closing the opening of the bucket main body, and the connecting frame is provided to connect the spline hole provided in the outer tube with the left and right lid plates of the rotary lid. The spline shaft is screwed into the spline hole, and the upper part of the spline hole is provided with a stepped part into which the lower part of the spline shaft can fit when rotating the spline shaft in reverse, and the spline shaft and the wing expansion bit are connected. It is characterized by a structure in which it is connected by a rod.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 8.

1 and 2 are sectional views of the bucket bag according to the present embodiment as seen from the side and the front, and FIG. 3 is an external view of the same. Further, FIG. 4 is a cross-sectional plan view of the bucket bag, FIG. 5 is a sectional view taken along the line A--A in Figure 4, and FIG. 6 is a bottom view of the bag bag.

To explain in order below, 10 is a cylindrical bucket main body, and 11 is a rotating lid provided inside the bucket main body 10. The rotating lid 11 can be rotated back and forth through a required angle, and opens and closes openings 12 provided at symmetrical positions in the cylindrical portion of the bucket main body 10.

A more specific structure of the bucket main body 10 is as follows. That is, a support frame 13 is constructed in the diametrical direction on the inside upper part of the bucket bag 10, and both ends of the support frame 13 are fixed to the inner circumferential surface of the bag bag main body 10.
The support frame 13 is fixed to the upper end of an outer tube 14 disposed at the center of the bucket main body 10 and is integrally constructed. This outer tube 14 includes a straight slide guide rail 16 having a T-shaped cross section and tilted at a required angle θ with respect to the axis.
16 is fixed. As shown in FIG. 2, wing expansion bits 18, 18 are arranged along slide guide rails 16, 16 so as to be movable up and down. To further explain the wing expansion bits 18, 18, 17, 17
is a guide block that slidably holds the slide guide rails 16, 16, and the guide block 1
7, 17 have openings 12 in the bucket main body 10.
A plurality of excavating cutting edges 18a, 18a, . . . are attached to this so as to be movable inwardly and outwardly through the excavating surface 18c, and to form an earth and sand excavating surface 18c. Continuing from the earth and sand excavation surface 18c, the expanded wing bit 18 is composed of a curved bottom surface part 18e, a earth and sand intake wall surface formed by a curved surface of a rear surface part 18d and an outer surface part 18f,
The cutting edges 18a, 18a are fixed to the front edge of the bottom surface 18e and the front edge of the outer surface 18f. The bottom surface portion 18e constitutes a part of an extension of the conical surface of a conical bottom plate 30 projecting downward from the bucket main body 10, which will be described later, or constitutes an approximate conical surface, so that the wing expansion bit 18 can be expanded to the maximum extent. When the bottom part 18
e is provided so as to be located on an extension of the inclined bottom plate 30.

As shown in FIGS. 1 and 5, a rotary scraper 43 is mounted on a shaft 42 supported by a bearing plate 38 on the rear side of the bottom surface 18e of the earth and sand intake wall.
This rotating scraper 43 rotates so as not to prevent the cutting edge 18a from digging when the expanding wing bit 18 rotates in the excavation direction (as shown by the dotted line in Figure 5), and on the other hand, after the bottom expanding excavation is completed, the bottom of the pile hole is removed. When the expanding wing bit 18 is rotated in the anti-excavation direction to scrape up scraps, the back surface of the rotary scraper 43 engages with the bearing reinforcing plate 40, is held, and moves to the right in the figure at the position indicated by the solid line in Figure 5. The earth and sand will be raked up. The soil collected at this time is removed from the bottom plate 3 of the bucket main body 10.
Move below 0. On the back surface of the bottom plate 30, fixed scrapers 44, 44 are arranged radially symmetrically from the center as shown in FIGS. 2 and 6.
The fixed scraper 44 is provided along the side edges of the openings 29, 29 formed at 0, and the earth and sand collected under the bottom plate 30 by the rotary scraper 43 is removed from the opening 29 to the inside of the bottom plate 30. It is now being sent to

Therefore, as shown by the chain lines in FIG.
0, and conversely when lowered to the lower end, the opening 12 of the bucket main body 10 will open as shown by the solid line in the same figure.
The cutting edge 18a, 18a of each tip is passed through the outside of the
...is going on a business trip.

The means for raising and lowering the wing spreader bits 18, 18 will be explained below. A spline hole 14a is provided on the inner periphery of the outer tube 14, and at the same time, a spline shaft 19 serving as a drive shaft is fitted into the spline hole 14a so as to be slidable in the axial direction (telescopically) and rotatably driven. That is, the threaded convex portion 19a formed on the spline shaft 19 shown in FIG. 7B is screwed into the spline hole 14a shown in FIG. 7D so as to be freely retractable. FIG. 7C shows the convex portion A and the concave portion B of the spline hole 14a as viewed from the inside.

The splines of the spline shaft 19 and the spline hole 14a have a certain angle with respect to the axis, and when transmitting rotation, generate a component force that cancels the axial frictional force generated at the meshing portion of the spline shaft 19 and the spline hole 19a. let In the case of this embodiment, since the spline shaft is twisted to the right, a downward component force is generated when the spline shaft is rotated to the right when viewed from above.

This torsion angle is an angle that cancels out the axial frictional force between the spline shaft 19 and the spline hole 14a; an excessively large angle is inconvenient for transmitting rotational force, and an insufficiently small angle prevents axial movement due to the frictional force. It is not smooth and is inconvenient, and requires an appropriate angle. Generally, carbon steel or copper alloy is used for the spline set, and the friction angle thereof is usually about 14° to 16°.

Further, in FIG. 7C, reference numeral 20 denotes a stepped portion provided at a predetermined height position of the spline hole 14a, and in the case of this embodiment, this stepped portion 20 is provided over an angle of approximately 45°. The lower threaded protrusion 19a of the spline shaft 19 can be fitted into the wide recess above the rotary lid 11, and at this time the rotary lid 11 closes the opening 12 of the bucket main body 10, which will be explained later.

At the upper end of the spline shaft 19, there are collars 21, 21.
A is provided between which an annular bearing 22 is screwed, and the upper ends of connecting rods 24, 24 are pivotally supported at both ends of a shaft pin 23 which projects from the annular bearing 22 on both sides. The lower ends of the connecting rods 24, 24 are connected to the wing expansion bit 18 by a pin 25. These connecting rods 24, 24 are connected to the wing expansion bit 1.
As 8 and 18 move up and down, the upper shaft pin 23
The support frame 13 is provided with elongated holes 13a, 1 to allow this swing.
3a is loosely inserted (see Fig. 4).

As described above, the bottom plate 30 of the bucket main body 10 has a conical shape projecting downward, and is rotatable about a pin 33 (as shown in FIGS. 1 and 6). That is, the bearing part 31 attached to the outer peripheral edge of the bottom plate 30 and the bucket main body 10
The bearings 32 provided on the lower inner periphery of the pins 3 are overlapped and
3, and the bottom plate 30 can be rotated downward using this pin 33 as a fulcrum. and,
An engagement hole 26 is provided on the bottom plate 30 at a position substantially symmetrical to the pin 33, and is attached integrally with the bottom cover. The engagement frame 26 is provided with an engagement hook 27a provided at the lower end of the operating rod 27 so as to be freely engageable and detachable.

To briefly explain the operation of the above configuration, the operation lever 2
7 is rotatably supported inside the bucket main body 10, and its upper end enters an operation box 45 installed inside the bucket main body 10, and inside the operation box 45, it is attached to the upper end of the operating rod 27. One end of a spring (not shown) is engaged with 27b to apply rotational force to the operating rod 27 in one direction.

After the bottom plate 30 rotates downward to open the lower end of the bucket main body 10 and discharge soil, the open bottom plate 30 comes into contact with the discharged estimated soil by lowering the bucket main body 10. Then, the crane starts to close, and the crane moves the crane as necessary to make it easier to close. As the bottom plate 30 is lifted and closed in this way, the engagement frame 26 is moved to the engagement hook 27.
A is rotated in one direction against the spring, and while being pushed away, moves to the upper side of the engagement hook 27a, and due to the spring force, the coupling hook 27a is rotated to its original position and attached to the engagement frame 26. It is adapted to automatically engage and close the lower end of the bucket main body 10. In addition, the bottom plate 3
0, by rotating the operating lever 27 against the spring, the engagement hook 27a is moved to the engagement frame 2.
It can be easily done by removing it from 6.

As shown in FIG. 6, the bottom plate 30 is also provided with a lid 35 that opens and closes the openings 29, 29 provided at symmetrical positions inward through a hinge 34 so as to be closed by its own weight during normal bottom-expanding excavation. be. However, opening 2
9 rotates the expansion bit 18 in the reverse direction at the final stage of bottom expansion pile hole excavation, and rotates the above-mentioned rotary scraper 4.
3 and the fixed scraper 44 are used to push up the lid 35 and take in the scraps remaining at the bottom of the pile hole into the bottom plate 30.

Next, the rotating lid 11 will be explained. As shown in FIG. 8, the lid plate 1 has two arcuate cross sections with the same curvature as the inner circumference of the bucket main body 10.
1a and 11a are provided so that their inner sides face each other, and their upper ends are fixed to both ends of the connecting frame 11b. When the rotating lid 11 is rotatably fitted inside the bucket main body 10, the connecting frame 11b is connected to the bucket main body 10 as shown in FIGS. 1 to 3.
The cover plate 11 is located above the support frame 13 and is rotatably supported on the upper surface of the support frame 13.
The upper end edge of the bucket body 10 hits a stopper 36 provided on the inner surface of the upper end of the bucket main body 10 and is prevented from being lifted upward. Further, in the center of the connecting frame 11b, a tube body 3 having a spline hole 37a on the inner periphery is provided.
7 is attached, and this spline hole 37a is rotated by being screwed into a threaded protrusion 19a provided on the spline shaft 19.

Therefore, as shown in FIG. 7C, the outer tube 14
A stepped portion 20 is provided at the upper part of the spline hole 14a provided on the inner periphery of the spline hole 14a over a predetermined angular range. When the bottom expansion bit 18 is pulled upward along the slide guide 16 as shown by the chain line in FIG. Due to the rotational force shown by the arrow, the rotating lid 11 rotates by the angle of the stepped portion 20 because the spline hole 37a at the center of the connecting frame 11b is threadedly engaged with the threaded protrusion 19a of the spline shaft 19. It rotates together with the spline shaft 19 to close the opening 12 of the bucket main body 10.

Next, a method of using the expanded bottom excavation bucket according to the present invention will be explained.

First, the pile hole 8 is excavated to a predetermined depth using a conventional bucket 5 shown in FIG. When the pile hole 8 is excavated to a predetermined depth, it is replaced with the bucket according to this embodiment. Thus, the spline shaft 19 attached to the lower end of the Kelly bar 4 has been pulled up, and the wing expansion bits 18, 18 are in the second position.
It is in a completely contracted state as shown by the chain line in the figure.

In this state, initially the lower part of the spline shaft 19 is inserted into the spline hole 14a as shown in FIG. 7C.
Next, the spline shaft 19 is rotated in the direction opposite to the arrow shown in the above figure, and the spline shaft 19 idles until it comes into contact with the slope on the right side of the spline shown in FIG. When the spline shaft 19
Since the spline hole 37a of the rotating lid 11 is engaged with the rotating lid 11, the rotating lid 11 rotates integrally with the spline shaft 19 at the same angle as the stepped portion 20, and the bucket main body 10
The opening 12 is opened.

Subsequently, a rotational force and a downward thrust are applied to the spline shaft 19, and the force is transmitted to the outer tube 14 through the uneven contact surfaces of the male and female splines, and the bucket main body 10, which is integrated with the outer tube 14, is rotated. tell. At the same time, since a downward thrust is applied to the spline shaft 19, the spline shaft 19 descends in the spline hole 14a. That is,
The spline shaft 19 telescopically enters the outer tube 14 and descends.

As a result, the expansion bits 18, 18 connected to the bearing ring 22 of the spline shaft 19 by the connecting rods 24, 24 gradually protrude in the radial direction through the opening 12, as shown in FIG. At this time, a conical enlarged bottom portion 8a corresponding to the inclination angle θ of the slide guide rails 16, 16 shown in the figure can be formed by turning downward. At this time, the earth and sand excavated by the excavating cutting edge 18a fixed to the edges of the bottom surface 18e and the outer surface 18f of the wing expansion bits 18, 18 is moved by the curved surfaces of the bottom surface 18e, outer surface 18f, and back surface 18d of the soil intake wall. It is smoothly fed into the opening 12 and taken into the bucket main body 10.

Next, as shown in Figure 1, expand the wing bit 1.
After the slide guide rails 16, 18 descend to the lower ends of the slide guide rails 16, 16 and excavate the expanded bottom portion 8a, the Kelly bar 4 is rotated in the opposite direction. As a result, the enlarged bottom part 8
Scraps left in the area of a are removed using the rotary scraper 43.
The lid 35 is pushed open through the opening 29 of the bottom plate 30 using the fixed scraper 44 and taken into the bucket main body 10. Thereafter, the Kelly bar 4 (shown in FIG. 9) is pulled up while continuing to rotate in the opposite direction.

Then, the spline shaft 19 is inserted into the spline hole 14.
a is slid in the direction of extension, and along with this, the wing expansion bits 18, 18 also move in the slide guides 16, 1.
6, and finally, the spline shaft 19 rotates at a predetermined angle along the step 20 of the spline hole 14a at that position, so that the rotary lid 11 closes the opening 12 of the bucket main body 10, and the bucket main body 10
The excavated earth and sand taken into the hole are prevented from spilling out from the opening 12.

Thereafter, the bucket main body 10 is pulled up from the bottom of the pile hole without any hindrance, moved to the loading platform of a dump truck or a dumped soil receiver, the bottom plate 30 is opened, and the dirt inside is discharged. A plurality of drainage openings 46 are formed in the circumferential body of the bucket main body 10 so as to discharge muddy water taken in together with earth and sand taken into the bucket main body 10. Note that a wire mesh 47 is stretched over the lower opening 46.

Further, the wing expansion bit 1 is moved up to the upper limit position of the slide guide rails 16, 16, which are provided at a required angle θ.
When pulling up 8, 18, expand the wing bits 18, 18.
can be moved to the opposite side beyond the center line of the outer tube 14 at the upper part of the guide rail, thus making it possible to provide a larger ratio of the minimum diameter to the maximum diameter of the enlarged bottom portion 8a.

Effects of the Invention According to the present invention, when excavating the bottom of a pile hole, a required amount of material is excavated through an opening that is housed in a bucket main body and is configured to be openable and closable in the bucket main body by forward and reverse rotation of a Kelly bar. The expanding wing bit expands and contracts while moving up and down along the slide guide rail installed at an angle, and has an earth and sand intake wall, making it possible to easily excavate an expanded pile hole while reliably taking excavated earth and sand into the bucket body. This has the effect of making it possible to construct an enlarged pile hole with a large tip support capacity against vertical loads.

[Brief explanation of drawings]

1 and 2 are a vertical front view and a vertical side view of an expanded bottom excavation bucket according to the present invention, FIG. 3 is a side external view, FIG. 4 is a cross-sectional plan view, and FIG. 5 is FIG.
Figure 6 is a bottom view of the bucket main body, Figure 7B is a front view of the spline shaft, Figure 7A is a cross-sectional view taken along line B-B' of figure B, Figure 7C is a sectional view taken along line A'. is a developed view of the spline hole provided on the inner circumference of the outer tube, Figure 7D
8A and 8B are enlarged sectional views showing the meshing relationship between the male and female splines in the spline shaft and the outer tube with spline holes, respectively; FIGS. 8A and 8B are plan and side views of the rotating lid;
FIG. 9 shows the main body of the crane used in the earth drilling method and its overall view. 4...Keriba, 10...Bucket body, 11
... Rotating lid, 11a ... Lid plate, 11b ... Connection frame, 12 ... Opening hole, 13 ... Support frame, 14 ... Outer tube, 14a, 37a ... Spline hole, 16 ...
Slide guide rail, 18... Wing expansion bit, 1
8a...Drilling cutting edge, 18d...Back part, 18e...
...bottom part, 18f...outer surface part, 19...spline shaft, 20...step part, 24...connection rod.

Claims (1)

[Claims] 1. An outer tube with a spline hole is arranged in the center of the bucket main body which has a bottom plate that can be opened and closed via a support frame, and a slide guide rail is fixed and installed on the outer surface of the outer tube at a required angle with respect to the axis. , a wing expansion bit that can be moved up and down is installed along the slide guide rail and through an opening provided on the outer periphery of the bucket main body, and the wing expansion bit has a curved bottom part, a back part, and a curved outside part. It is equipped with an earth and sand intake wall formed by a curved surface with the face part, and a digging cutting edge provided along the edge of the bottom part and an excavating cutting edge provided along the edge of the outer side part, and further has an opening and closing hole in the bucket main body. A rotating lid is provided, and a spline shaft is screwed into the spline hole provided in the outer tube and the spline hole provided in the connecting frame between the left and right lid plates of the rotating lid. An expanded bottom excavation bucket characterized by a structure in which a stepped portion is provided into which the lower part of the spline shaft can fit when the spline shaft is reversely rotated, and the spline shaft and the wing expansion bit are connected by a connecting rod.