JP2008144429A - Spiral blade, drilling implement wound with spiral blade, and manufacturing method for spiral blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spiral blade which is wound around a drilling implement, which can reduce resistance to the insertion of the spiral blade into ground when a hole is drilled and which can be efficiently rotated and inserted with a little labor, the drilling implement which is wounded with the spiral blade, and a manufacturing method suitable for the manufacture of the spiral blade. <P>SOLUTION: This spiral blade is wound around the lower outer periphery of the base shaft of the drilling implement which drills the hole by being pulled up after being rotatively inserted into the ground while rotating the base shaft. A lower end of the spiral blade is formed in such a shape as to oblique with respect to the radial direction of a spiral. When the spiral blade is mounted on the drilling implement, the lower end of the spiral blade, that is, a surface abutting on an underground section makes a predetermined angle viewed from above with respect to the radial direction of the spiral blade. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spiral blade attached to a drilling tool capable of digging a hole of a desired depth in the ground by inserting and pulling up the spiral while pushing and rotating the spiral body, and a hole attached to the spiral blade The present invention relates to a digging tool and a method for manufacturing a spiral blade.

  Conventionally, as a manual digging tool used for burying a pile, a pole, a support column, or the like, for example, one disclosed in JP-A-11-303118 (Patent Document 1) is known.

  The drilling tool is provided with a handle in a substantially T shape at the top of the base shaft, and has a steel spiral blade at the lower portion, and a strong insertion shaft portion below the spiral blade, and a tip of the insertion shaft Is formed in a protruding shape, and a steel screw part is provided below.

  In the drilling tool, the spiral blade is wound around the lower outer periphery of the base shaft by double winding (720 degrees), the spiral blade has a gentle inclination angle, and the spiral blade that narrows the interval is made of steel. Since the earth cutting edge is provided on the outer peripheral edge, the root of the tree can be cut off and the earth can be removed. It is easy to insert into the ground, and since the steel lead screw is provided in the insertion shaft portion, it is possible to help the approach to the ground.

  However, the leading screw is for inserting the drilling tool into the ground, and the drilling operation itself is performed by the spiral blade, but as shown in FIG. 20, the lower end S1 of the spiral blade S, That is, since the contact surface when rotating and inserting into the ground is formed linearly along the radial direction R of the spiral blade S, the entire width of the contact surface is cut into the ground at the start of drilling. The insertion resistance into the ground is large, and depending on the drilling tool, considerable effort is required to perform the rotational insertion into the ground.

JP-A-11-303118, page 1, FIG. 1 and FIG.

  The present invention has been made in view of such circumstances, and when drilling using the drilling tool, the insertion resistance of the spiral blade into the ground during drilling can be reduced, and there is little It is an object of the present invention to provide a spiral blade capable of efficiently rotating and inserting with effort, a drilling tool for attaching the spiral blade, and a manufacturing method suitable for manufacturing the spiral blade.

  The spiral blade according to claim 1, wherein the spiral blade is provided on a lower outer periphery of the base shaft of a drilling tool for drilling by rotating the base shaft, rotating and inserting it into the ground, and pulling it up. The lower end of is formed so as to be skewed with respect to the radial direction of the spiral.

  The spiral blade according to claim 1, wherein when mounted on the drilling tool, the lower end of the spiral blade to be installed below the drilling tool is skewed with respect to the radial direction of the spiral. Therefore, the lower end of the spiral blade, that is, the contact surface to the ground has a predetermined angle in a plan view with respect to the radial direction of the spiral blade, and when the drilling tool is rotated, Since it enters the ground from one end in the width direction of the contact surface, the insertion resistance of the spiral blade into the ground can be reduced compared to entering the ground from the entire width of the contact surface, and rotation insertion can be efficiently performed with less labor. It can be carried out.

  The spiral blade according to claim 2 is the spiral blade according to claim 1, wherein the lower end of the spiral blade is formed in a curved shape.

  In the spiral blade according to claim 2, since the lower end of the spiral blade is formed in a curved shape in the spiral blade according to claim 1, when the spiral blade enters the ground, It is possible to smoothly enter the ground, and the insertion resistance of the spiral blade into the ground can be further reduced.

  The drilling tool according to claim 3 is characterized in that the spiral blade according to any one of claims 1 and 2 is attached downward.

  In the drilling tool according to claim 3, since the lower end of the spiral blade to be installed below the drilling tool is formed obliquely with respect to the radial direction of the spiral, The lower end of the spiral blade, that is, the contact surface to the ground, has a predetermined angle in a plan view with respect to the radial direction of the spiral blade, and when the drilling tool is rotated, the contact surface from one end in the width direction of the contact surface Therefore, it is possible to reduce the insertion resistance of the spiral blade into the ground compared to entering the ground from the full width of the contact surface, and it is possible to efficiently perform the rotational insertion with less labor. Moreover, when the lower end of the spiral blade is formed in a curved shape, when the spiral blade enters the ground, it can enter the ground more smoothly, further reducing the insertion resistance of the spiral blade into the ground. can do.

  A method for manufacturing the spiral blade according to claim 4 is a method for manufacturing the spiral blade according to claim 1, wherein a circular hole through which the base shaft passes is cut out from a flat plate formed in a circular shape, and the spiral blade is manufactured. A step of cutting at a predetermined angle with respect to the radial direction of the flat plate to form a lower end, and a female having a spiral surface that coincides with the male mold that forms the spiral surface and the male mold that forms the cut and cut flat plate And a step of forming a spiral shape by pressing with a mold.

  In the manufacturing method of the spiral blade according to claim 4, the spiral blade is manufactured by a step of cutting and cutting a circular plate and a step of press-molding the flat plate formed in the step with a male mold and a female mold. Therefore, the spiral blade can be manufactured easily and inexpensively without using a special manufacturing machine.

  The manufacturing method of the spiral blade according to claim 5 is the manufacturing method of the spiral blade according to claim 4, wherein the cutting step cuts out a circular hole through which the base shaft passes from a flat plate formed in a circular shape. In order to form the lower end of the blade, the blade is cut into a curved shape at a predetermined angle with respect to the radial direction of the flat plate.

  In the manufacturing method of the spiral blade according to claim 5, since the lower end of the spiral blade is cut into a curved shape in a flat plate state, the spiral blade is formed more easily than being cut into a curved shape after being formed into a spiral shape. Can do.

  According to the first aspect of the present invention, there is provided a spiral blade that is provided on the lower outer periphery of the base shaft of a drilling tool that performs drilling by rotating and inserting the base shaft into the ground and pulling it up. Since the lower end of the blade is formed so as to be skewed with respect to the radial direction of the spiral, when it is attached to the drilling tool, the lower end of the spiral blade, that is, the contact surface to the ground, A predetermined angle is obtained in a plan view with respect to the radial direction, and when the drilling tool is rotated, since it enters the ground from one end in the width direction of the contact surface, the above-mentioned rather than entering the ground from the full width of the contact surface Insertion resistance of the spiral blade into the ground can be reduced, and rotation insertion can be performed efficiently with little effort.

  According to the invention described in claim 2, in addition to the spiral blade according to claim 1, the lower end of the spiral blade is formed in a curved shape, so that when the spiral blade enters the ground, It is possible to smoothly enter the ground, and the insertion resistance of the spiral blade into the ground can be further reduced.

  According to the third aspect of the present invention, since the spiral blade according to any one of the first or second aspect is attached downward in the drilling tool, the lower end of the spiral blade is in the radial direction of the spiral. The lower end of the spiral blade, that is, the contact surface to the ground, forms a predetermined angle in a plan view with respect to the radial direction of the spiral blade, and the drilling tool is rotated. Since it enters the ground from one end in the width direction of the contact surface, the insertion resistance of the spiral blade into the ground can be reduced compared to entering the ground from the entire width of the contact surface, and rotation insertion can be efficiently performed with less labor. It can be performed. Moreover, when the lower end of the spiral blade is formed in a curved shape, when the spiral blade enters the ground, it can enter the ground more smoothly, further reducing the insertion resistance of the spiral blade into the ground. can do.

  According to invention of Claim 4, it is a method of manufacturing the spiral blade of Claim 1, Comprising: The circular hole which the said base axis penetrates is excised from the flat plate formed circularly, and the lower end of the said spiral blade is formed. A step of cutting at a predetermined angle with respect to the radial direction of the flat plate to be formed, and a female die having a spiral surface that matches the male die and a male die that forms a spiral surface of the cut and cut flat plate. The spiral blade is manufactured by a step of cutting and cutting a circular plate and a step of pressing and molding the flat plate formed in the above step with a male die and a female die. Therefore, the spiral blade can be manufactured easily and inexpensively without using a special manufacturing machine.

  According to a fifth aspect of the present invention, in the method for manufacturing the spiral blade according to the fourth aspect, the cutting step includes cutting a circular hole through which the base shaft passes from a flat plate formed in a circular shape, and Since the lower end is formed at a predetermined angle with respect to the radial direction of the flat plate and cut into a curved shape, the lower end can be formed more easily than being formed into a helical shape and then cut into a curved shape.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

  FIG. 1A is a front view of a drilling tool according to the present invention, and FIG. 2 is an enlarged view of the main part of FIG. 1A, and FIG. 3 is an enlarged view of the main part of FIG.

  1 to 3, reference numeral 10 denotes a drilling tool according to the present invention, and the tip end of a base shaft 12 formed of a metal pipe material is closed as a sharpened portion so as to easily enter the ground. A handle portion 13 formed of a metal pipe material is fixed to the base end of the base shaft 12 by welding so as to intersect with the base shaft 12 and have a substantially T shape as a whole. A rubber grip 14 is put on both ends of the handle portion 13.

  A spiral body 20 (21, 22) that hangs a cutting blade 30 (31, 32) on the outer peripheral edge is provided by welding at the distal end portion of the base shaft 12. The spiral body 20 (21, 22) includes a first spiral blade 21 provided at the distal end portion of the base shaft 12, and a second spiral blade 22 provided at a position symmetrical to the first spiral blade 21 on the base shaft 12. It consists of two spiral blades 21 and 22.

  The first spiral blade 21 is provided so as to wind the base shaft 12 360 degrees below the distal end portion of the base shaft 12, and the second spiral blade 22 is symmetrical with the first spiral blade 21. In such a position, the base shaft 12 is provided so as to be wound 360 degrees. That is, the fixed position of the upper end 22b of the second spiral blade 22 is shifted by 180 degrees with respect to the fixed position of the upper end 21b of the first spiral blade 21, and the starting position of the spiral is shifted by 180 degrees. Thus, a double spiral structure in which two spiral blades 21 and 22 are arranged is formed.

  FIG. 4 is an exploded view showing the spiral body, (a) is an exploded view of the first spiral blade, and (b) is an exploded view of the second spiral blade. 5 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 6 is a vertical cross-sectional view of a main part of the first spiral blade.

  The spiral blades 21 and 22 are formed by skewing the lower ends 21a and 22a with respect to the radial direction R2 of the spiral blades 21 and 22 (see FIGS. 10 and 11). That is, the lower ends 21a and 22a of the spiral blades 21 and 22 are formed with a predetermined angle α (see FIGS. 10 and 11) in a plan view with respect to the radial direction R2. The lower ends 21a and 22a are formed in a linear shape, but may be formed in a curved shape (see FIG. 17C).

  Further, a cutting edge 31 formed in a substantially fan shape is provided at the lower end of the outer peripheral edge of the first spiral blade 21 with a bladed surface 31a inclined forward with respect to the rotation direction on the lower end 21a of the first spiral blade 21. A similar cutting blade 32 is suspended at a position facing the cutting blade 31, that is, at the lower end of the outer peripheral edge of the second spiral blade 22.

  Since each of the cutting blades 31 and 32 is formed so as to be inclined forward in the lower part of the cutting blade with respect to the rotation direction as described above, when this is rotated and inserted into the ground, The stone can be pushed up to the upper surface of the spiral blade, and the roots remaining in the soil can be efficiently cut.

  Further, as shown in FIG. 6, each of the cutting blades 31 and 32 has protrusions 31b and 32b that protrude slightly upward (in the present embodiment, about 10 mm to 15 mm) from the upper surfaces of the spiral blades 21 and 22, respectively. Each has formed. Accordingly, the cutting blades 31 and 32 are formed with the protruding portions 31b and 32b, thereby ensuring the upper welding resistance and increasing the strength so that the upper and lower surfaces can be welded, and the protruding portions 31b. 32b can effectively embrace the lump cut by the cutting blades 31 and 32 when the drilling tool 10 is pulled out from the ground. The cutting blades 31 and 32 are made of carbon steel whose wear resistance and impact resistance are improved by heat treatment, and the bladed surfaces 31a and 32a are subjected to a cutting process to cut the peripheral surface of the hole. Improve ability.

  7 is a sectional view taken along the line BB in FIG. 2, FIG. 8 is a plan view of the pushing plate, and FIG. 9 is an enlarged sectional view taken along the line CC in FIG.

  As shown in detail in FIG. 7 to FIG. 9, the push plate 40 is welded by fitting a truncated conical metal plate having a diameter substantially the same as the diameter of the excavation hole HL at a position above the spiral body 20 in the base shaft 12. An insertion hole 40a of the base shaft is opened at the center of the pushing plate 40, and an annular flat surface 40b around the annular flat surface 40b and a truncated cone-shaped tapered surface 40c around the annular flat surface 40b. Forming.

  The spiral blades 21 and 22 attached to the drilling tool 10 having the above-described configuration are manufactured as follows.

  FIGS. 10A and 10B are diagrams showing a cutting process of a circular flat plate, where FIG. 10A is a perspective view of the flat plate, and FIG. 10B is a plan view of the flat plate. 11A and 11B are diagrams showing another flat plate cutting and cutting step, where FIG. 11A is a perspective view of the flat plate, and FIG. 11B is a plan view of the flat plate. 12 is a schematic view showing a pressing process of a flat plate formed into a predetermined shape, FIG. 13 is a schematic view showing a pressed state, and FIG. 14 is a schematic view showing a state where a circular flat plate is formed in a spiral shape.

  First, as shown in FIG. 10, an insertion hole 51 through which the base shaft 12 is inserted is extracted at the center of a circular metal plate 50, cut along the radial direction R1 of the circular plate 50, and the diameter is reduced. Cutting is performed at a predetermined angle α with respect to the direction R2 (obliquely with respect to the radial direction R2). At this time, the length D1 of the cut surface 52b cut along the radial direction R1 and the length D2 of the cut surface 52a cut at a predetermined angle α with respect to the radial direction R2, the 52a is the radial direction R2 Therefore, D2 is formed longer than D1. In addition, in the said process, as shown in FIG. 11, you may cut | disconnect in a curved shape, when making a predetermined angle (alpha) with respect to radial direction R2. In this case, 52a is formed longer than D2.

  The flat plate 50 cut and cut into a predetermined shape in the above process is subjected to press forming in a spiral manner by a press machine 60 including a male die 61 and a female die 62 shown in FIGS. The male mold 61 has a cylindrical protrusion 61a through which the insertion hole 51 is inserted at the center, and a spiral surface 61b is formed around the cylindrical protrusion 61a. The female die 62 is provided with a circular hole 62a into which the protruding portion 61a can enter at the center, and a spiral surface 62b that coincides with the spiral surface 61b is formed around the circular hole 62a.

  Then, as shown in FIG. 12, between the male mold 61 and the female mold 62, the projecting portion 61a is positioned so as to insert the insertion hole 51 of the circular flat plate 50, as shown in FIG. Further, the female mold 62 is pressurized, and the circular flat plate 50 is formed into a spiral shape as shown in FIG.

  The case where the said drilling tool 10 formed as mentioned above is used is demonstrated. FIG. 15 thru | or FIG. 19 is a schematic diagram which shows the usage method of the drilling tool which concerns on this invention.

  First, as shown in FIG. 15, the sharpened portion of the drilling tool 10 is pierced perpendicularly to the ground G. At this time, when the tip of the cutting blade 31 is similarly pierced into the ground, and 3 points are pierced on the ground and rotated and pressed in the manner of drawing a circle with a compass, centering during excavation can be easily performed at an accurate position It is possible to perform excavation vertically without being inclined.

  Next, as shown in FIG. 16, the drilling tool 10 is pressed and rotated, and the side surface of the hole HL is inserted into the ground while being cut by the cutting blades 31 and 32. At this time, according to the conventional drilling tool, the lower end (that is, the contact surface) S1 of the spiral blade S is linearly formed along the radial direction of the spiral S as shown in FIG. Therefore, the entire width of the lower end S1 is hit against the rotation direction indicated by the arrow, but depending on the drilling tool 10 according to the present invention, as shown in FIGS. 17 (b) and 17 (c). As described above, the lower ends (that is, contact surfaces) 21a and 21c of the spiral blade 21 enter the ground from the point K and sequentially enter the point P according to the rotation direction indicated by the arrows. Insertion resistance into the ground will decrease.

  Then, as shown in FIG. 18, the pressing plate 40 continues to rotate to such an extent that it slightly enters the ground, and as shown in FIG. It is pulled out while being placed on the spiral body 20.

  As described above, when excavating using the drilling tool 10 with the spiral blades 21 and 22 attached thereto according to the present embodiment, when the drilling tool 10 is rotated, the spiral blades 21 and 22 Since the lower end 21a, 22a (that is, the contact surface) enters the ground G from one end on the base shaft 12 side in the width direction, the spiral blades 21, 22 are underground rather than entering the ground from the entire width of the lower ends 21a, 22a. Insertion resistance to G can be reduced, and rotation insertion can be performed efficiently with little effort.

  In addition, although the said drilling tool 10A of this Embodiment comprised the said spiral blade 21A, 22A with two sheets, it is not limited to this, It can comprise with an appropriate number and position. Similarly, the cutting blades 31A, 32A, and 33A can be arranged in appropriate numbers and positions.

(A) is a front view of the drilling tool of 1st Embodiment based on this invention, (b) is a side view. It is a principal part enlarged view of Fig.1 (a). It is a principal part enlarged view of FIG.1 (b). It is an exploded view which shows a spiral body, (a) is an exploded view of a 1st spiral blade, (b) is an exploded view of a 2nd spiral blade. It is the sectional view on the AA line of FIG. It is a principal part longitudinal cross-sectional view of a 1st spiral blade. It is BB sectional drawing of FIG. It is a top view of a pushing board. FIG. 9 is an enlarged sectional view taken along the line CC in FIG. 8. It is a figure which shows the cutting and cutting process of a circular flat plate, (a) is a perspective view of a flat plate, (b) is a top view of a flat plate. It is the schematic which shows the cutting and cutting process of another flat plate. It is the schematic which shows the press process of the flat plate shape | molded by the predetermined shape. It is the schematic of a press state. It is the schematic which shows the state which shape | molded the circular flat plate helically. It is a schematic diagram which shows the usage method of a drilling tool. It is a schematic diagram which shows the usage method of a drilling tool. It is a schematic diagram which shows the usage method of a drilling tool. It is a schematic diagram which shows the usage method of a drilling tool. It is a schematic diagram which shows the usage method of a drilling tool. It is the schematic which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Drilling tool 12 Base shaft 20 Spiral bodies 21 and 22 Spiral blades 21a and 22a Lower end (contact surface) of spiral blade
R1, R2 radial direction

Claims (5)

A spiral blade installed on the lower outer periphery of the base shaft of the drilling tool for drilling by rotating the base shaft and rotating it into the ground and pulling up,
The spiral blade is characterized in that a lower end of the spiral blade is formed to be skewed with respect to the radial direction of the spiral.
The spiral blade according to claim 1, wherein a lower end of the spiral blade is formed in a curved shape.
A drilling tool characterized in that the spiral blade according to claim 1 is attached downward.
The method for manufacturing the spiral blade according to claim 1, wherein a circular hole through which the base shaft passes is cut out from a circular flat plate and the lower end of the spiral blade is formed with respect to the radial direction of the flat plate. A step of cutting at a predetermined angle, and a step of pressing the cut and cut flat plate into a spiral shape by pressing with a male die having a spiral surface and a female die having a spiral surface coinciding with the male die, The manufacturing method of the spiral blade characterized by comprising.
  In the cutting step, a circular hole through which the base shaft passes is cut from a flat plate formed in a circular shape, and cut at a predetermined angle with respect to the radial direction of the flat plate to form a lower end of the spiral blade. The manufacturing method of the spiral blade of Claim 4 characterized by these.

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