JPS6358999B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foundation bottom expansion excavation device for an earth drill that further enlarges and excavates the foundation bottom of a foundation pile hole excavated during construction work.

Conventionally, it has been known that the bottom of the lower end of a pile is made larger to strengthen the supporting force at the tip of the pile, but the present inventor has already proposed in Utility Model Application No. 139289/1989 a method for further strengthening the supporting force at the tip. It is proposed to increase the depth of the bottom of the expansion.
In other words, conventional foundation bottom expansion excavation equipment has a retractable cutter on the side of the bucket and expands only the radial direction of the hole bottom. At the same time, he proposed a device for drilling. However, in this proposed device, the protruding operation of the cutter from the bucket was based on a mechanism in which a rotary drive shaft provided at the core of the bucket was connected to the cutter, and this drive shaft was moved relative to the bucket. Due to the influence of soil quality, etc., the vines may not protrude to the specified position, and there is a risk that the foundation base will not be expanded sufficiently. If such a situation were to occur, it would become impossible to make the tip of the foundation pile the desired size, and there was a possibility that the supporting capacity of this pile would be significantly reduced compared to the initial one.

The present invention has been made in order to eliminate the above-mentioned drawbacks.The invention uses a hydraulic drive mechanism to control the movement of the cutter into and out of the bucket, and the cutter is erected at an angle of about 45 degrees with respect to the axis of the bucket. In addition, the lower side of the cutter is supported and guided by a radial reinforcing member via a support plate to ensure smooth ejection and retraction operation of the cutter without clogging with crushed soil. Furthermore, an enlargement of the base of the earth drill is provided with a cutter detection mechanism that detects that the side cutter has protruded from the opening by lowering the piston rod by a predetermined amount using the operation of the hydraulic drive mechanism that drives the cutter. The company provides drilling equipment.

The present invention will be described below with reference to illustrated embodiments. In FIGS. 1 to 4, 1 is a cylindrical bucket, and as shown in FIG. The foundation E is simultaneously expanded in the radial and depth directions by the side cutters 3 and bottom cutters 4, which will be described in detail later, by rotating in the direction of arrow W by a drive motor 28 connected to the upper end of the rotary drive shaft 2. It is something to be excavated.

Reference numeral 5 denotes openings for taking in waste soil formed on the side of the bucket 1, and in this embodiment, three openings are provided at 120° intervals around the axis. As shown in FIG. 2, this side opening 5 has an elongated trapezoid shape with the rear side in the rotational direction, that is, the right side, as the vertical side, and a pin 6 is attached to the mounting metal part inside the upper edge of the vertical side. Through this, the top edge of the side cutter 3, which has a substantially fan shape, is pivotally supported. The side cutter 3 swings about a pin 6 as a fulcrum by the operation of a hydraulic cylinder 7, which will be described later, so that it can freely protrude and retract from the side opening 5 in the radial direction. However, side cutter 3 is bucket cutter 1.
The other side of the fan-shaped support plate 8 is inclined forward in the rotational direction at an angle of about 45° with respect to the axis of is fixed. In addition, a claw-shaped cutter 3 is provided on the outer periphery of the protruding portion of the side cutter 3.
The lower part 3b of this protruding part is formed to be parallel to the axial direction of the bucket 1, making it easy to excavate the hole in the depth direction.

Reference numeral 10 denotes a substantially conical bottom lid constituting the bottom of the bucket 1, which is connected to the bucket 1 via a hinge 11.
It is pivotally attached to the cylindrical part. Reference numeral 12 denotes a lock rod for closing the bottom lid 10, which passes through this along the axial direction of the bucket 1. An arrowhead-shaped lock portion 12a is provided on the protruding portion from the bottom lid 10. An operating handle 12b is formed on a protruding portion from the top of the handle 1. The operating handle 12b is always energized by a spring 13, and is automatically locked when the bottom cover 10 is closed. That is, a long hole 14 matching the shape of the lock part 12a is bored in the bottom cover 10, and after rotating the lock rod 12 against the spring 13, the lock part 12a is inserted into the long hole 14. When the bottom cover 10 is closed, it is automatically locked. The bottom cover 10 also has an opening 1 in a portion corresponding to each of the three side openings 5.
5, and bottom cutters 4 each consisting of a plurality of claw-like cutters 4a are provided at the rear edge in the rotational direction of each opening 15 to protrude radially from the center of the bottom thereof.

At the edges of the side and bottom openings 5, 15 facing the mounting sides of the cutters 3, 4,
A side shutter and a bottom shutter (not shown) are each hinged. These two shutters have a flat plate shape that closes the required portions of each opening 5, 15, and can only swing inward to the bucket 1, so that the waste soil taken in from the openings 5, 15 spills. It is now possible to prevent this.

The hydraulic cylinder 7 is for causing the side cutter 3 to protrude and retract from the side opening 5,
A connecting member 17 is attached to the tip of the piston rod 16, and both ends of an arm 18 are pivotally connected to the connecting member 17 and the side cutter 3, respectively. Therefore, by lowering the piston rod 16, the side cutter 3 can be projected outward via the arm 18. Reference numerals 19 and 20 denote an oil supply pipe and an oil drain pipe for supplying and discharging pressure oil to the hydraulic cylinder 7, respectively, which are provided along the drive shaft 2 as shown in FIG. It is connected to a hydraulic power source (not shown) through it. A hydraulic pressure detector (not shown) is connected to this hydraulic pressure source, and the hydraulic pressure is recorded on an XY recorder so that the operator can confirm fluctuations in the hydraulic pressure acting on the hydraulic cylinder 7.

Reference numeral 22 designates a limit switch attached to the main body of the hydraulic cylinder 7, which is pressed and released by a protruding member 23 formed on the piston rod 16. That is, when the piston rod 16 descends and the side cutter 3 protrudes by a predetermined amount, the limit switch 22 is turned on. 2
4 is a conductive wire that transmits the ON/OFF state of the limit switch 22, and is provided along the drive shaft 2, as shown in FIG. The signal is transmitted to the conductive wire 26 on the fixed side. This ground conductive wire 26 is connected to the XY recorder and display lamp (not shown), and is connected to the side cutter 3.
When protrudes by a predetermined amount, the indicator lamp lights up,
Further, a signal is recorded on an XY recorder so that the operation of the side cutter 3 can be visually confirmed.

By the way, when the foundation bottom is expanded and excavated using the foundation bottom expansion excavation device according to the above configuration, not all of the excavated soil is necessarily taken into the bucket 1, and some remains at the bottom of the hole, so it is necessary to dredge up this remaining soil. It is.
In addition, since the lower cutter 3c of the side cutter 3 is located above the bottom cutter 4, a step B is formed as shown in FIG. 9c, so this is further cut to ensure the required cross-sectional shape. It is necessary to finish it in a bowl shape. FIGS. 5 to 8 show a bottom dredging device for the purpose of this bottom dredging, and this device basically has the same structure as the above-mentioned expanding excavation device. That is, Bucket 29
is formed with a pair of trapezoidal side openings 30;
A side shovel 31 having substantially the same shape as the trapezoid and having an arcuate cross section is pivotally attached to the edge of the opening 30.
Hydraulic cylinder 32 provided on the shaft of bucket 29
The connecting member 3 attached to the tip of the piston rod 33 of
4 and the shovel 31 are connected by an arm 35, and the side shovel 31 can be opened and closed with respect to the opening 30 by this hydraulic cylinder 32.

The bottom side 31a of the side shovel 31 is substantially on the same straight line as a bottom shovel 41, which will be described later,
The bottom of the hole can be finished into a mortar shape without forming a step.

Reference numerals 36 and 37 are oil supply pipes and oil drain pipes for supplying and discharging pressure oil to the hydraulic cylinder 32, and these are installed on the ground via a swivel joint, similar to the oil supply pipe 19 and oil drain pipe 20 in the above-mentioned expanded drilling equipment. Connected to hydraulic power source.

Further, a bottom cover 38 pivotally attached to the bottom of the bucket 29 has substantially the same configuration as the bottom cover 10 of an enlarged excavation device, and the bottom can be opened and closed via a lock rod 39 having an arrowhead-shaped lock portion 39a. It's becoming possible.
Reference numeral 40 designates a pair of bottom openings formed in the bottom cover 38, each of which has a bottom shovel 41 at its edge.
is installed.

Note that shutters are hinged to both of the openings 30 and 40, respectively, to prevent the waste soil taken into these openings 30 and 40 from spilling.

The foundation bottom expansion excavation work using the foundation bottom expansion excavation device and bottom dredging device having the above configuration is performed as follows. That is, first, a regular excavation bucket is attached to the tip of the rotary drive shaft 2, the pile core is positioned as shown in Fig. 9a, and excavation is started. Excavation will be carried out at the same time. Then, the bucket cart 1 for expanding excavation according to the present invention is pulled up and replaced with the bucket cart 1 for expanding excavation according to the present invention.
As shown in Fig. 9c, set the bucket 1 at the foundation bottom E, and while driving it to rotate, press the hydraulic cylinder 7.
Expanded excavation is performed by supplying pressure oil to the side cutters 3 to project them outward. At this time, use the XY recorder to visually check that the oil pressure has risen to a predetermined value or higher and that there has been no further rise, check that the side cutter 3 has reached the expanded protruding position, and check that the indicator lamp is lit. Then start digging downward. That is, the foundation bottom has a predetermined diameter and is excavated in the depth direction. After the excavation is completed,
The hydraulic cylinder 7 is driven to house the side cutter 3 in the bucket 1, and the bucket 1 is pulled up.

Next, a bottom dredging bucket 29 is attached in place of the bucket 1, and the bucket 29 is driven to rotate in the same manner as excavation with a normal excavation bucket to cut the step B of the foundation bottom E and dredge up the remaining soil. This foundation E is finished by forming.

Furthermore, by inserting a reinforcing bar cage G with a tip shovel into the hole in which the foundation bottom has been enlarged and excavated, and pouring concrete H therein, a foundation pile having an enlarged bottom I with a depth D as shown in Fig. 9g is obtained. is completed.

As described above, according to the present invention, since the protrusion and retraction of the side cutter from the bucket is controlled by the hydraulic drive mechanism, the side cutter can not only be reliably protruded to a predetermined position, but also
The side cutter has a reinforcing member extending in the radial direction of the bucket on its lower side, and is erected at an angle of about 45 degrees in the bucket rotational direction from this reinforcing member, and the reinforcing member in contact with the lower edge of the opening and the lower edge of the side cutter Since the support flat plate is continuously provided between them, the cutter can exhibit a good biting degree to the hole wall, and the cutter, which is firmly supported by the radial reinforcing member through the support plate, can be inserted under the opening. The cutter is slidably guided by the reinforcing member against the edge, so that smooth ejection and retraction operation of the cutter without clogging of crushed soil can be expected, and the piston rod is lowered by a predetermined amount using the hydraulic drive mechanism that drives the cutter. , limit switch
Since the ON state detects when the side cutter is in the protruding position protruding from the opening, the protruding position of the side cutter can be instantly confirmed with a simple mechanism, and the foundation bottom can always be excavated in the planned shape. Effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the main parts of the foundation expansion excavation device according to the present invention, FIG. 2 is a front view showing the foundation expansion excavation device with the side cutter protruding, and FIG.
The figure is a top view of Figure 2, Figure 4 is a bottom view of Figure 2,
Fig. 5 is a front view showing the side shovel of the bottom dredging device in an open state, Fig. 6 is a front view showing the side shovel of the bottom dredging device in an open state, Fig. 7 is a plan view of Fig. 6, and Fig. 8 are bottom views of Fig. 6, Fig. 9 a to g.
is an explanatory diagram of the sequence of foundation pile driving work. 1...bucket, 3...side cutlet, 4...
Bottom cutter, 5... Side opening, 15... Bottom opening, 7... Hydraulic drive mechanism (hydraulic cylinder),
22, 23... Katsuta detector.

Claims (1)

[Claims] 1. A cylindrical bucket with openings for taking in soil at the sides and bottom, a bottom cutter fixed along the bottom opening, and a bottom cutter that is pivotally supported at the upper end of the side opening. The side cutter is equipped with a substantially fan-shaped side cutter that can be freely extended and retracted from the bottom, and a hydraulic drive mechanism that controls the drive of the side cutter to extend and retract. A supporting flat plate is installed in a row at an angle of approximately 45 degrees, and is connected to the reinforcing member that is in contact with the lower edge of the opening and the lower side of the side cutter. A foundation bottom enlarging excavation device for an earth drill, characterized in that a detection mechanism for detecting that the side cutter protrudes from the opening is constituted by a protrusion member formed at the operation end position of the piston rod to press the side cutter.