JPH0532486U - Earth drill drill - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a cone of an earth drill that is easy to manufacture and low in manufacturing cost. [Structure] A plurality of 1-pitch vane pieces 4 ... The 1-pitch blade pieces 4 have a twist angle with a central angle of about 360 ° when viewed from the direction of the axis L. Therefore, 1
The pitch blade pieces 4 ... Can be easily manufactured from a single annular metal plate or the like, and are easily fixed to the outer peripheral surface of the shaft 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cone of an earth drill for drilling a ground.

[0002]

[Prior Art]

 In the conventional earth drill cone, as shown in FIG. 8, one long blade c continuous in a spiral shape is provided in a protruding shape on the outer peripheral surface of a shaft b provided with a cutting blade a at the lower end. Things were commonly used.

[0003]

[Problems to be solved by the device]

 However, in the conventional earth drill cone as described above, one blade c has a long spiral shape, so that it is difficult to manufacture, and there is a problem that the manufacturing cost of the earth drill increases.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a cone of an earth drill which can be manufactured easily and can be manufactured at a reduced cost.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the cone of the earth drill according to the present invention has a plurality of 1-pitch blade pieces having a twist angle with a central angle of about 360 ° when viewed from the axial direction, at fixed intervals. Is attached to the outer peripheral surface of the shaft in a protruding manner.

[0006]

[Action]

 When the cone is pushed against the ground and rotated, the soil is cut by the tip of the shaft and the blades, and there is a hole in the ground. After that, if you pull out the whole cone of the earth drill from the ground, the soil in the hole will be taken out by the root piece.

[0007]

EXAMPLES The present invention will be described in detail below with reference to the drawings illustrating examples.

FIG. 1 shows an embodiment of a cone of an earth drill according to the present invention. The cone 1 is a shaft 2 made of a metal pipe and a substantially triangular metal plate attached to the tip of the shaft 2. And a 1-pitch blade piece 4 attached to the outer peripheral surface of the shaft 2 at a predetermined interval S so as to project.

The cutting blade portion 3 has a notch portion 10 on the upper side, and left and right upper end edges 11 and 12 thereof are formed in a stepped shape. Then, the lower end portion of the shaft 2 is fitted and welded from the opening end of the cutout portion 10. Alternatively, a slit is cut out at the lower end of the shaft 2 and the upper end of the plate-shaped cutting blade 3 is inserted from below and welded.

Further, connecting screw holes 5 and 5 are provided at the upper end of the shaft 2.

Next, as shown in FIG. 2, the one-pitch blade piece 4 is made of one metal plate. In other words, the 1-pitch blade piece 4 cuts a part of the annular metal plate in the radial direction and separates the cut edges vertically with a predetermined pitch dimension P to form the upper edge 6 and the lower edge 7, It is formed in a spiral shape.

Further, as shown in FIG. 3, the one-pitch blade piece 4 has a twist angle θ having a central angle of about 360 ° when viewed from the axial center L direction. Therefore, in plan view, the upper edge 6 and the lower edge 7 of the one-pitch blade piece 4 are substantially aligned.

The inner peripheral edge 8 of the one-pitch blade piece 4 is welded to the outer peripheral surface 9 of the shaft 2.

The predetermined spacing S and the predetermined pitch dimension P of the one-pitch blade pieces 4 ... (Returning to FIG. 1) can be set freely. For example, it is desirable to set 0.5 · P ≦ S ≦ 1.0 · P. Further, in the illustrated example, three 1-pitch blade pieces 4 are provided, but it is also preferable that the number of blades is 2 or 4 to 10. The outer diameter of the blade 4 is less than 200mm, and it is a convenient earth drill.

Next, as shown in FIG. 4, it is also preferable that the lower part of the cutting blade portion 3 is slightly twisted around the axis L. The lower upper edge 12 of the cutting blade portion 3 is welded to the back surface near the lower end portion 7 of the one-pitch blade piece 4 thereabove.

Further, the lower end of the shaft 2 is closed by a disc-shaped wall portion 13 in plan view.

Then, as shown in FIG. 5, the cone 1 is attached to the rotary drive device 16 provided with the motor 14 with reduction gear and the handles 15 and 15. That is, a drive shaft 17 protruding below the motor 14 with a reducer is inserted from the upper end opening of the shaft 2 of the cone 1, and a bolt (not shown) is passed through the connecting screw holes 5 and 5 to insert a nut. Tighten.

Then, if the handle 15 of the rotary drive device 16 is gripped by hand and the power is turned on, the cone 1 rotates and a hole can be made in the ground.

That is, soil is dug by the cutting blade portion 3, the 1-pitch blade piece 4 imparts a force to push the cutting blade portion 3 downward, and the blade piece 4 has an outer diameter dimension. Crush the soil within the close hole diameter. Since there is a predetermined interval S, the force to discharge the soil upward is weak, but after pushing it to a certain depth, pulling out the whole (turning off the power) causes the soil in the hole to move together with the blade piece 4. Can be discharged.

Next, FIG. 6 and FIG. 7 show another embodiment of the cone 1, which has a slit 18 having a downward opening formed at the center of the lower end of the cutting blade 3. In addition to being bifurcated, the cutting tip edges 19, 19 are twisted so as to be substantially perpendicular to the upper end edges 11, 12 of the cutting blade portion 3 when viewed from the axial center L direction.

In addition to the above-described embodiment, the present invention can be freely changed in design without departing from the scope of the invention. For example, the cutting blade portion 3 can be flat without twisting. It is also preferable to attach a horizontal rod-shaped handle (not shown) to the upper end of the shaft 2 and rotate the cone 1 by hand.

[0022]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects.

Since the 1-pitch blade pieces 4 have a twist angle θ with a central angle of about 360 ° when viewed from the direction of the axis L, a part of the annular metal plate is cut in the radial direction. It can be easily manufactured by forming a spiral shape. Since the 1-pitch blade pieces 4 are small pieces of 1 pitch, they can be easily attached to the outer peripheral surface of the shaft 2 by welding or the like.

Further, the cone of the earth drill of the present invention has the same drilling action as the cone of the conventional earth drill having long spiral upper and lower blades, and is easy to manufacture and Cost can be reduced. Also, it requires less rotation torque.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a one-pitch blade piece.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a side view of a main part.

FIG. 5 is a front view showing a usage state.

FIG. 6 is a front view of a main portion showing another embodiment.

FIG. 7 is a bottom view showing another embodiment.

FIG. 8 is a diagram showing a conventional example.

[Explanation of symbols]

 2 shaft 4 blade piece L axis center S predetermined interval θ

Claims (1)

[Scope of utility model registration request] 1. A plurality of one-pitch vane pieces 4 having a twist angle θ having a central angle of about 360 ° when viewed from the direction of the axis L are attached to the outer peripheral surface of the shaft 2 in a protruding manner at predetermined intervals S. The drill of the earth drill that is characterized.