JP2010247306A - Two-shaft hole saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transform a gourd type drilled bore into an elliptic type drilled bore, which is formed when using a two-shaft hole saw wherein a rotary input shaft 2 is protrudedly provided on a base side, a rotation transmission mechanism part outputting rotary input to the rotary input shaft to parallel two shafts having the same rotating speed is provided in a holding body 1 provided with rotary cutting parts 3 on the front side, and the rotary cutting parts comprise drill shafts 31 extended from the parallel two shafts and branch plates provided around each drill shaft with an arrangement in which cutting blade bodies parallel to the drill shafts and having corresponding protrusion lengths to the tip positions of the drill shafts are provided on the peripheral tips, and the peripheral tips are engaged with each other not to collide. <P>SOLUTION: Fixed blades 34 whose protrusion lengths correspond to the tip positions of the drill shafts are provided on both outer positions of the intermediate position of the drill shafts 31 almost on the tangential line of rotation locus circles of both cutting blade bodies 32. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a biaxial hole saw having a through-hole for embedding an outlet or a switch box in a wall surface mainly formed of a gypsum boat.

  The hole saw is formed with a drill at the tip of a known rotating shaft, a disk or a branch plate is provided around the drill shaft, and a cutting blade is provided at the outer periphery of the disk or at the tip of the branch plate in parallel with the drill. Are connected to an appropriate electric tool, and the face plate is wound in a circle with a rotating drill and cutting blade (see Patent Documents 1 and 2).

  In addition, when the outlet B or switch box is embedded in the wall surface A, it is necessary to dig a vertically long hole in addition to a simple circular hole. As a tool for digging this vertically long hole, a biaxial hole saw is used. Are known. This instrument is equipped with a biaxial transmission mechanism inside the gripping body with a rotating input shaft projecting at the base, with two drills projecting in parallel on the front and engaging the branch plates with each drill shaft. In this case, the cutting trajectory circles drawn by the cutting blades partially overlap each other, so that the vertically long drilling hole by the instrument is formed in a bowl shape. It will be.

Japanese Utility Model Publication No. 7-11846. Japanese Patent Laid-Open No. 9-103906.

  An excavation hole by a hole saw provided with the above-described biaxial drill is formed in a bowl shape in which two circular portions overlap each other like an excavation drill a shown in FIG. For this reason, in particular, when an outlet is installed in the digging hole a, it is necessary to allow some margin for position change, and it is necessary to cut out the hook-shaped constricted portion b.

  The excision of the constricted portion b needs to be performed again after the excavation work with the hole saw, and the work is troublesome twice.

  Therefore, the present invention proposes a novel biaxial hole saw that forms a vertical digging for an outlet.

  The biaxial hole saw according to the present invention has a parallel biaxial shaft in which a rotational input shaft protrudes on the base side and a rotational input to the rotational input shaft has the same rotational speed in a gripping body provided with a rotational cutting portion on the front side. A rotation transmission mechanism portion that outputs to the drill shaft, and the rotation cutting portion includes a drill shaft that is an extension of the parallel two axes, and a protrusion length that is parallel to the drill shaft at the outer peripheral tip and corresponds to the tip position of the drill shaft. In a biaxial hole saw that is provided with a small cutting blade and is arranged so that the outer peripheral tips mesh with each other so that they do not collide with each other, the rotation trajectory of both cutting blades A fixed blade body having a protruding length corresponding to the tip position of the drill shaft is provided at both outer positions in the middle position of the drill shaft, which are approximately tangent to the circle.

  Thus, when the rotary input shaft is connected to the output shaft portion of an appropriate rotary electric tool, the drill shaft and the branch plate rotate, and when the rotary cutting portion is pressed against the drilling target wall surface, By cutting the center cutting blade, a bowl-shaped perforation is formed on the wall, and at the same time, the fixed blade is inserted into the constricted part, so that the constricted part is excised, resulting in a single operation. A long hole close to an ellipse is formed.

  Since the present invention has the above-described configuration, the drilling is performed with two rotating cutting blades, and at the same time the constricted portion of the rotating circle of the cutting blade is cut with a fixed blade. A long hole close to an elliptical shape (non-cone shape) could be formed in one operation.

The front view of the embodiment of the present invention. The side view of the rotation cutting part. Explanatory drawing of the perforated state.

  Next, an embodiment of the present invention will be described. The biaxial hole saw shown in the embodiment is basically provided with a rotary input shaft 2 on the base side of the gripping main body 1 and a rotary cutting part 3 on the front side as in the conventional instrument.

  The gripping main body 1 is provided with a rotation transmission mechanism portion that outputs rotation input to the rotation input shaft 2 to parallel two shafts having the same rotation speed, surrounds the rotary cutting portion 3 on the front side, and rotates. A cover body 11 that allows the distal end side of the cutting portion 3 to be relatively exposed is provided.

  Each of the rotary cutting parts 3 includes a pair of drill shafts 31, a branch plate 33 provided with a cutting blade body 32, and a fixed blade body 34, and the drill shaft 31 is a parallel biaxial shaft in the gripping body 1 described above. It is an extension and the tip is formed in a drill.

  The branch plate 33 is provided around the base side of the drill shaft 31, the tip is parallel to the drill shaft 31 and has a protruding length corresponding to the tip position of the drill shaft 31, and a carbide tip is attached to the tip. The cutting blade body 32 is provided, and when the rotary operation is performed together with the drill shaft 31, the outer peripheral tips of the branch plates 33 are engaged so as not to collide with each other.

  The fixed blade 34 is on an approximately tangent line that is in contact with both circles of the two rotation trajectory circles of the cutting blade 32, and has an appropriate width at both outer positions between the drill shafts 31 and The projecting length corresponds to the tip position of the drill shaft.

  Thus, the rotary input shaft 2 and the output shaft portion of an appropriate rotary electric tool are connected, the electric tool and the gripping body 1 are held in the hand, the electric tool is operated, and the drill shaft 31 and the branch plate 33 are connected. When the rotary cutting part 3 is pressed against the wall surface A to be drilled, the surface of the wall A is punched by the drill shaft 31 and the cutting blade body 32 centered on the drilled portion. Although the mold perforation a is formed, the fixed blade 34 is simultaneously inserted into the constricted portion b, so that the constricted portion b is excised, and as a result, a long hole c close to an ellipse is formed in a single operation. Will be established.

  In addition, the cover body 11 is operated so as to move in and out relative to the rotary cutting portion 3, and only the rotary cutting portion 3 is pushed into the wall surface A while the cover body 11 is in contact with the wall surface A. Chip scattering is prevented.

DESCRIPTION OF SYMBOLS 1 Grasping body 11 Cover body 2 Rotation input shaft 3 Rotation cutting part 31 Drill shaft 32 Cutting blade body 33 Branch plate 34 Fixed blade body

Claims (1)

  A rotation transmission mechanism in which a rotation input shaft projects from the base side and a rotation input to the rotation input shaft is output to two parallel shafts having the same number of rotations in a gripping body having a rotation cutting portion on the front side. A rotary cutting part, a drill shaft that is an extension of the parallel two axes, and a cutting blade body that has a protruding length parallel to the drill axis and corresponding to the tip position of the drill shaft at the outer peripheral tip, In a biaxial hole saw composed of branch plates arranged around each drill shaft in such a manner that the outer peripheral tips engage with each other so as not to collide with each other, the drill shaft that is approximately tangent to the rotation trajectory circle of both cutting blades 2. A biaxial hole saw characterized in that a fixed blade body having a protruding length corresponding to the tip position of the drill shaft is provided at both outer positions at an intermediate position.

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