JPH0312197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw pipe for drilling holes in the ground, and in drilling holes in the ground using a casing made of a steel pipe, etc. Regarding screw tubes for drilling holes.

When creating foundation piles, there are two methods: drilling hard holes from the ground surface and then erecting ready-made piles, or casting concrete to create piles, or using spring water with mortar, hardening agent, etc. without discharging the excavated soil. Methods such as injecting and kneading soil mortar to create soil mortar piles are often used.

An excavator is used to excavate the ground in any of the above land reclamation operations, but as shown in Fig. 1, conventional excavators have screw blades 2 spirally formed around the outer periphery of a shaft 1, and An auger screw 4 having a digging blade 3 is used, and if necessary, a casing 5 made of a steel pipe or the like is fitted around the outer circumference of the auger screw 4.
The auger screw 4 is connected to the drive unit 6 of an excavator and driven to rotate to drill a hard hole in the ground, and the excavated soil and gravel are connected to the drilled hole or the inner peripheral surface of the casing 5. It is stored between the shaft 1 and transported upward by the rotation of the screw blade 2,
It is designed to be discharged onto the ground.

However, when drilling a hole in a place where the excavation ground is a gravel area and there are many large gravels, the size of the gravel A may be smaller than the inner surface of the hole or the casing 5 and the shaft 1, as shown in the second figure.
There are problems such as being restricted by the gap between the concrete and gravel, making it impossible to transport gravel that is larger than that gap, being restricted by the ground, and having to use a casing 5 and auger screw 4 with a larger diameter than necessary. Ta.

In view of this, the present invention has been made with the aim of solving the above-mentioned conventional problems.The present invention is made by fixing a screw blade member in a spiral shape to the inner peripheral surface of a casing made of a steel pipe or the like. Window holes are arranged at required intervals on the circumferential surface of the casing to allow the earth and sand to come into contact with the inner surface of the drilled hole in order to provide resistance to the earth and sand carried on the screw blades. The present invention provides a screw tube for ground drilling, in which a pipe for injecting a chemical solution is spirally provided on the screw blade, and even gravel larger than the radius of the screw blade can be taken in and transported.

Hereinafter, the present invention will be described with reference to the embodiments shown in FIGS. 3 to 9, with the same reference numerals assigned to parts common to those in FIG. 1.

FIG. 3 shows the external appearance of the screw tube 7 according to the present invention, and FIG. 4 is an enlarged perspective view of a part thereof, showing a casing 8 made of a steel pipe or the like, and a screw tube fixed to the inner peripheral surface of the casing 8 in a spiral shape. It consists of a screw blade 9, and this screw blade 9 is axisless.

A required number of window holes 10, 10, . . . are formed on the circumferential surface of the casing 8 at intervals in the axial direction (for example, every other pitch of the screw blades 9). As shown in the cross section of FIG. 5, this window hole has an opening width extending approximately 1/4 of the circumference at a diametrically symmetrical position.

A chemical liquid injection pipe 11 for injecting mortar, soil hardening agent, etc. is spirally arranged on the screw blade 9, and the upper end thereof can be connected to a chemical liquid supply source of an excavator. The lower end is opened at the base of the excavating blade 12 at the lower end of the screw blade 9.

For manufacturing the screw blade 9, for example, as shown in one plane in FIG. 6, a metal plate is press-formed into a disk shape having a center hole 13, and a number of slits 14 are formed in the radial direction. This is twisted spirally by shifting it up and down at the slit 14 part as shown in Figure 7, and the lower edge of the slit 14 part and the upper edge of the next slit 14 part are connected. It is formed into a screw shape by sequentially connecting them by welding.
Furthermore, the welding to the casing 8 is performed by the window holes 10 and 1.
This can be done by using 0...

Since the present invention has the above configuration, when the screw pipe 8 is connected to the drive unit 6 of an excavator and is driven to rotate to excavate a hard hole in the ground, the excavation blade 12 at the lower end of the screw blade 9 removes earth and sand. The excavated soil is placed on screw blades 9 and conveyed upward. During this transportation, the earth and sand on the screw blade 9 comes into contact with the inner peripheral surface of the drilled hole at the window holes 10, 10... opened in the casing 8, receives frictional resistance, and slides on the screw blade 9. The casing 8 is conveyed upward without any movement and is discharged to the ground from the upper end of the casing 8.

If large gravel A is found during the above-mentioned excavation, the screw blade 9
It penetrates beyond the center of the body and is sent upwards.

When stirring the excavated soil and injecting mortar etc., the pipe 11 is
You can inject liquid medicine through the tube.

FIGS. 10 to 13 show modified examples of the present invention. The embodiment shown in FIG. In the embodiment, the window holes 10 are formed in an axially elongated oval shape, one of which is shown in FIG. 12, and are formed so that their axial positions are shifted from each other in the helical direction of the screw blades 9. Alternatively, as shown in FIG. 13, the window holes 10 may be formed in a series that is long in the axial direction. Furthermore, the excavating blade 12 is attached to the lower end of the screw blade 9, and also to the casing 8.
Alternatively, the excavating blade 12 provided on the screw blade 9 may not protrude from the lower end of the casing 8 but may be positioned within the casing 8 as shown in FIG.

As explained above, in the present invention, screw blades are screwed onto the inner circumferential surface of the casing without a shaft, and holes are drilled by the lower end of the screw blade or the drilling blade at the lower end of the casing, so that the space between the screw blades is Even if there is large gravel in the ground, it can be accommodated and carried upward without being obstructed by the shaft, and even in the ground where large gravel exists, holes can be drilled without any problem. In addition, the required number of window holes are provided on the circumferential surface of the casing, and through these windows, the earth and sand and gravel placed on the screw blade come into contact with the inner surface of the drilled hole and receive frictional resistance. Even if the chemical liquid is placed on the screw blade and transported upwards, it is ensured that the liquid is transported upward, and since the chemical liquid injection pipe is provided in a spiral shape on the screw blade, various effects such as being able to inject mortar and other chemical liquids are achieved. have

[Brief explanation of drawings]

FIG. 1 is a side view showing a conventional excavator, FIG. 2 is a horizontal sectional view showing the state of conveying gravel by a conventional casing auger, and FIG. 3 is a front view showing an embodiment of the screw tube according to the present invention. FIG. 4 is an enlarged perspective view of the same part, FIG. 5 is a horizontal sectional view of the same, FIGS. 6 and 7 are explanatory diagrams of one means for manufacturing the screw blade of the screw tube, and FIGS. 8 and 9. 1A and 1B are vertical and horizontal sectional views showing the gravel conveying state of the screw tube according to the present invention, and FIGS. 10 to 13 are explanatory views showing other modified examples. 8...Casing, 9...Screw blade, 1
0...Window hole, 11...Pipe for chemical injection, 12...
...Drilling blade.

Claims (1)

[Claims] 1. It has a casing made of a steel pipe or the like, and a screw blade without a shaft that is fixed to the inner circumferential surface of the casing in a spiral manner, and window holes are arranged and opened at required intervals on the circumferential surface of the casing. A screw tube for ground drilling, wherein the screw blade is provided with a pipe for injecting a chemical liquid in a spiral shape, and a drilling blade is provided at the lower end, and the upper end of the casing is connectable to a drive unit of an excavator.