JPH05318459A - Rotary cutting tool - Google Patents

Abstract

PURPOSE:To process always and accurately a crest-cutting-off part with a definite width even if the cutting radius of a main cutting blade is changed. CONSTITUTION:A rotating shaft 12 is provided at the apex of a rotatively driven main shaft 11. An arm 14 is projected from the main shaft 11 in the right angle direction to the main shaft 11. A main cutting blade 15 rotating at the rotating shaft 12 as the center and perforating a round hole is provided at the apex of the arm 14. A sub-cutting blade 16 for cutting off a crest is provided in the neighborhood of the main cutting blade 15. The arm 14 is slidably mounted on the main shaft 11 so as to change the radius from the rotating shaft 12 to the main cutting blade 15. In the rotatively cutting tool constituted like this, the sub-cutting blade 16 is fixed at a position being apart from the line connecting the rotating shaft 12 and the main cutting blade 15. The outermost peripheral part of the sub-cutting blade 16 is positioned on the straight line connecting the rotating shaft 12 and the outermost periphery of the main cutting blade 15 by bending the outer periphery side of the sub-cutting blade 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cutting tool for cutting a circular cutting hole in a ceiling material or the like.

[0002]

2. Description of the Related Art Generally, when attaching a downlight or the like to a ceiling or the like, a circular cutting hole 2 is made in the ceiling 1 as shown in FIG. There is. However, the ceiling 1 and the like are formed by adhering the decorative board 5 to the base plate 4, and the decorative board 5 often has irregularities 6. But makeup board 5
If there is unevenness 6 on the surface, when the device 3 is attached, a gap S is formed between the peripheral edge of the device 3 and the decorative board 5, and the appearance is deteriorated. Therefore, when the cutting hole 2 is cut, it is performed to form the mountain dropping portion 7 in which the mountain of the unevenness 6 is dropped on the periphery of the cutting hole 2 by cutting. When the mountain drop portion 7 is provided, the device 3 is attached to the decorative board 5 in close contact with each other without a gap.

A rotary cutting tool for simultaneously processing the cutting hole 2 and the mountain removing portion 7 is formed as shown in FIGS. 8 to 10. A main shaft 11, which is driven to rotate, is rotatably inserted into the main body 10, and the center of rotation 1
A drill 12a as 2 is attached. This spindle 11
A slide base 13 is attached to the tip of the spindle 11.
The arm 14 arranged so as to be orthogonal to the slide base 1
It is attached to 3 so that it can slide freely. The arm 14 is adapted to slide inward and outward along a long hole 14a of the arm 14, and the arm 14 can be fixed by a set screw 14b. The pair of arms 14 are interlocked with each other to slide in synchronization with the inside and outside directions.
A main cutting edge 15 is attached to the tips of the pair of arms 14 so as to be parallel to the drill 12a, and a sub-cutting edge 16 for removing the mountain is provided near the main cutting edge 15 at the tips of the arms 14. The outermost circumference of the main cutting edge 15 and the outermost circumference of the sub cutting edge 16 are circumferentially displaced from each other. Reference numeral 17 denotes a bowl-shaped cover attached to the main body 10 so as to surround the outer periphery,
It is designed to prevent the scattering of cutting chips and to ensure the safety of workers.

The formation of the cutting hole 2 and the mountain dropping portion 7 in the ceiling 1 or the like with this rotary cutting tool is carried out as follows. A chuck of a rotating device such as an electric drill is coupled to the main shaft 11, and the drill 12a and the arm 14 are rotationally driven by rotationally driving the main shaft 11, and the drill 12a first opens a central hole. As shown in FIG. 10, the main cutting edge 15 pierces the cutting hole 2, and the sub cutting edge 16 cuts the mountain dropping portion 7 following the piercing of the cutting hole 2.

[0005]

By the way, in the case of the above-mentioned conventional example, a straight line a passing through the center drill 12a and the main cutting edge 15 and a straight line b connecting the center drill 12a and the outermost cutting edge 16 with each other. Are displaced as shown in FIGS. 11 and 12, and the cutting radius of the main cutting edge 15 is R1 as shown in FIG.
And the cutting radius of the sub cutting edge 16 is r1 and the main cutting edge 15 and the sub cutting edge 1 are
When the radius difference with 6 is adjusted to 3.0 mm, the width actually dropped is 5.2 mm. Next, the positions of the main cutting edge 15 and the sub cutting edge 16 are the same, When only the cutting radius is changed from R1 to R2 (at this time, the cutting radius of the sub cutting edge 16 changes from r1 to r2), the width actually dropped by the action of the cutting radius becomes 5.2 mm to 8.4 mm, There is a problem that it is not possible to accurately remove the mountain because it is out of order by 3.2 mm. Note that FIG. 11 shows a state where the cutting diameter is increased to R1 and FIG. 12 is a state where the cutting diameter is decreased to R2.

The present invention has been made in view of the above problems, and an object of the present invention is to accurately machine a mountain drop portion having a constant width even if the cutting radius of the main cutting edge changes. To provide rotary cutting tools.

[0007]

In order to achieve the above object, the rotary cutting tool of the present invention is provided with a rotation center shaft 12 at the tip of a main shaft 11 which is driven to rotate, and an arm extending from the main shaft 11 in a direction orthogonal to the main shaft 11. 14 is provided so as to project, and the rotation center shaft 12
A main cutting edge 15 for rotating a circular hole to form a circular hole is provided at the tip of the arm 14, and a sub-cutting edge 16 for removing the mountain is provided in the vicinity of the main cutting edge 15. Blade 1
The arm 14 has the main shaft 11 so that the radius up to 5 can be changed.
In the rotary cutting tool that is slidably attached to the auxiliary cutting edge 16, the auxiliary cutting edge 16 is fixed at a position away from the straight line connecting the rotation center shaft 12 and the main cutting edge 15, and the outer peripheral side of the auxiliary cutting edge 16 is bent and rotated. The outermost peripheral portion of the auxiliary cutting edge 16 is located on a straight line connecting the central axis 12 and the outermost periphery of the main cutting edge 15.

The auxiliary cutting edge 14 is attached to the main cutting edge 15 so that the outermost peripheral portion of the sub cutting edge 14 is positioned on a straight line connecting the rotation center shaft 12 and the outermost periphery of the main cutting edge 15. It is also preferable to characterize it.

[0009]

Since the outermost peripheral portion of the auxiliary cutting edge 16 is located on the straight line connecting the rotation center shaft 12 and the outermost periphery of the main cutting edge 15, even if the cutting radius of the main cutting edge 15 is changed, the main cutting edge is changed. The crest portion 7 having a width between the outer peripheral portion of the blade 15 and the outer peripheral portion of the auxiliary cutting edge 16 is always cut. As a result, the mountain dropping part 7 with a predetermined width is always
Is cut accurately.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The rotary cutting tool of the present invention is constructed as shown in FIGS. 1 to 4, but the basic construction is the same as the conventional example. A main shaft 11, which is driven to rotate, is rotatably inserted into the main body 10, and a drill 12 a as a rotation center shaft 12 is attached to the tip of the main shaft 11. A slide base 13 is mounted on the tip of the main shaft 11, and an arm 14 arranged so as to be orthogonal to the main shaft 11 is slidably mounted on the slide base 13. This arm 14 is arm 1
It is configured to slide inward and outward along the four long holes 14a, and the arm 14 can be fixed by a set screw 14b. The pair of arms 14 are interlocked with each other to slide in synchronization with the inside and outside directions. A main cutting edge 15 is attached to the tips of the pair of arms 14 so as to be parallel to the drill 12a, and a sub-cutting edge 16 for removing the mountain is provided near the main cutting edge 15 at the tips of the arms 14.
By sliding the arm 14 with respect to the slide base 13, the cutting radius from the drill 12a to the main cutting edge 15 can be freely adjusted, and the cutting hole 2 having an arbitrary diameter can be drilled. .. These drills 12a,
Arm 14, slide base 13, main cutting edge 15, sub cutting edge 1
A bowl-shaped cover 17 is provided so as to surround the outer periphery of 6 and the like, and the cover 17 is attached to the main body 10.

The auxiliary cutting edge 16 is attached to a bracket 19 at the tip of the arm 14 by means of a mounting screw 18 so that the position of the auxiliary cutting edge 16 can be adjusted inward and outward, and the tip of the auxiliary cutting edge 16 faces the outer circumference of the main cutting edge 15. Is bent and the sub-cutting edge 16
The outermost peripheral portion 16a is located on a straight line connecting the drill 12a and the outer peripheral portion of the main cutting edge 15. This outermost peripheral portion 16a
Is sharp. The width W between the outermost peripheral portion 16a of the sub cutting edge 16 and the outer peripheral portion of the main cutting edge 15 can be freely adjusted by loosening the mounting screw 18.

The formation of the cutting hole 2 and the mountain dropping portion 7 in the ceiling 1 and the like with the rotary cutting tool having the above-described structure is performed as follows. A chuck of a rotating device such as an electric drill is connected to the main shaft 11, and the drill 12a and the arm 14 are rotationally driven by rotationally driving the main shaft 11. The drill 12a first opens a central hole, and then the main cutting is performed. The cutting hole 2 is perforated by the blade 15, and the mountain cutting portion 7 is cut by the sub cutting edge 16 following the perforation of the cutting hole 15. At this time, since the outermost peripheral portion 16a of the sub cutting edge 16 is located on the straight line connecting the drill 12a and the outer peripheral portion of the main cutting edge 15, even if the cutting radius is changed, the mountain dropping portion 7 having a constant width is always provided. Is cut. That is, the outermost peripheral portion 1 of the auxiliary cutting edge 16 is always
The mountain dropping part 7 having the width of the interval between the 6a and the main cutting edge 15 is cut, and the mountain dropping part 7 having the width corresponding to the interval is cut by changing the interval.

FIG. 5 shows another embodiment. In the case of this embodiment, instead of bending the tip of the sub cutting edge 16, the sub cutting edge 16 is attached to the main cutting edge 15 so that the tip of the sub cutting edge 16 comes on the line connecting the main cutting edge 15 and the drill 12a. I am trying. The sub cutting edge 16 is attached to the bracket 20 attached to the main cutting edge 15 with a mounting screw 21.
When the mounting screw 21 is loosened, it is possible to move (adjust) in the height direction (axial direction) with respect to the radial position and the main cutting edge 15 by the lateral elongated hole 22 provided in the auxiliary cutting edge 16. ..

1 and 2, the bracket 19 attached to the arm 14 has an arm portion 19a and has a main cutting edge 1a.
Touching 5. This is because the bracket 19 supports the main cutting edge 15 so that the main cutting edge 15 does not deform due to cutting resistance when rotated in the rotation direction shown by the arrow in FIG.

[0015]

As described above, according to the present invention, since the outermost peripheral portion of the auxiliary cutting edge is located on the straight line connecting the rotation center axis and the outermost periphery of the main cutting edge, the cutting radius of the main cutting edge is changed. Even if the ridge drop portion of the width between the outer peripheral portion of the main cutting edge and the outer peripheral portion of the auxiliary cutting edge is always cut, the ridge drop portion of a predetermined width is always accurately cut. ..

[Brief description of drawings]

FIG. 1 is a plan view of a main part of an embodiment of the present invention.

FIG. 2 is a plan view showing a state in which the position of the sub cutting edge of the same is changed.

FIG. 3A is a plan view for explaining a cutting state of the same.
(B) is an enlarged view of a main part.

FIG. 4 is a plan view of the entire same as above.

FIG. 5 shows another embodiment of the above, (a) is a plan view,
(B) is a front view.

FIG. 6 (a) is a plan view showing a cutting hole opened in a ceiling,
(B) is sectional drawing of the attachment state of an instrument.

FIG. 7 (a) is a plan view showing a state in which a cutting hole is provided in a cutting hole opened in the ceiling, and FIG. 7 (b) is a sectional view showing a state in which an instrument is attached.

FIG. 8 is a partially cutaway front view showing a state in which a conventional cutting hole is opened.

FIG. 9 is a partially cutaway front view showing a state in which a conventional cutting hole is being formed.

FIG. 10 is a plan view illustrating a state in which a conventional mountain dropping portion is cut.

FIG. 11 is a plan view of a state in which a conventional cutting hole having a large diameter is set so as to be drilled.

FIG. 12 is a plan view showing a state in which a conventional cutting hole having a small diameter is set so as to be drilled.

FIG. 13 is an explanatory diagram illustrating a conventional defect.

[Explanation of symbols]

 11 Spindle 12 Rotation Center Axis 14 Arm 15 Main Cutting Edge 16 Sub Cutting Edge

Claims (2)

[Claims] 1. A main cutting machine in which a rotation center shaft is provided at the tip of a rotation driven main shaft, and an arm is provided so as to project from the main shaft in a direction orthogonal to the main shaft, and a circular hole is formed by rotating about the rotation center shaft. A blade is provided at the tip of the arm, and a secondary cutting edge for removing the mountain is provided near the main cutting edge, and the arm is slidably mounted on the main axis so that the radius from the rotation center axis to the main cutting edge can be changed. In the rotary cutting tool, the auxiliary cutting edge is fixed at a position away from the straight line connecting the rotation center axis and the main cutting edge, and the outer peripheral side of the sub cutting edge is bent to form the rotation center axis and the outermost circumference of the main cutting edge. A rotary cutting tool characterized in that the outermost peripheral portion of the auxiliary cutting edge is located on the straight line connecting the two. 2. A main cutting machine in which a rotation center shaft is provided at a tip of a rotation driven main shaft, and an arm projects from the main shaft in a direction orthogonal to the main shaft, and which rotates around the rotation center shaft to form a circular hole. A blade is provided at the tip of the arm, and a secondary cutting edge for removing the mountain is provided near the main cutting edge, and the arm is slidably mounted on the main axis so that the radius from the rotation center axis to the main cutting edge can be changed. In the rotary cutting tool, the sub cutting edge is attached to the main cutting edge, and the outermost peripheral portion of the sub cutting edge is located on a straight line connecting the rotation center axis and the outermost periphery of the main cutting edge. Rotary cutting tool.