JPS6116009Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a punching cutter device used for drilling holes in concrete walls, etc. in plumbing and wiring work for water, gas, electricity, etc.

Conventional drilling cutters for drilling holes for piping and wiring in concrete walls, etc. are structured so that they can only drill holes from one side of the wall. Alternatively, holes had to be drilled separately from both sides of the wall. For this reason, in the former case, there were problems in that a large edge chipping occurred at the peripheral edge of the hole on the other side of the wall surface, and in the latter case, the holes were misaligned.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a punching cutter device that can prevent edge chipping at the periphery of a hole and can drill holes without misalignment.

In the drilling cutter device for concrete walls, etc. of the present invention, a first drilling cutter having a cutter blade at one end is attached to a cutter mounting portion provided at the base of a center drill. A cylindrical body has a female thread portion corresponding to the thread-shaped cutting edge of the center drill protruding from the first drilling cutter and can be screwed onto the drill, and a compression coil spring attached near the tip of the cylindrical body A second punching cutter having the same outer diameter and substantially the same shape as the first punching cutter is mounted opposite to the first punching cutter so as to be able to rotate coaxially and integrally with the cylindrical body. It has a structure.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In Figures 1 and 2, a center drill 2 whose one end is removably fitted into an electric or air drill body 1 has a cutter attachment part 3 consisting of a large-diameter male threaded part at its base, and the above-mentioned attachment A thread-like blade portion 4 of a required length extends at the tip of the portion. In the cutter mounting portion 3, a plurality of cutter blades 5 having a fixed cutting edge direction are evenly arranged on the cylindrical periphery, and one side wall surface A with a required outer diameter has grooves 6 for discharging initial powder on the outer peripheral surface. cylindrical first perforation cutter 7 for
The screw thread-like blade part 4 protrudes from the end face of the cutter blade 5 and is attached so as to rotate together with the center drill 2. A screw hole 8 is formed in the inner wall of the threaded blade portion 4 protruding from the end surface of the cutter blade 5, with one end open and a male threaded portion for screwing into the threaded portion of the threaded blade portion 4 inside. and the second
As shown in the figure, a cylindrical body 11 having a rectangular cross-sectional shape and having a male threaded portion 10 near its tip for attaching a compression coil spring 9 is screwed onto the cylindrical body 11. Since the threaded hole 8 of the cylinder 11 does not pass through as shown in the figure, the tip portion having the male threaded portion 10 can be projected and screwed into the cylinder, and the cylinder 11 can be easily removed from the center drill 4. can. Further, on the outside of the cylindrical body 11, there is provided a hole for the other side wall B of the same shape and the same outer diameter, with the direction of the cutting edge of the first perforation cutter 7 and the cutter blade 5 and the direction of the cutting edge grooves 6 for discharging chips being different. Cylindrical second perforation cutter 12
is slidably mounted facing the first drilling cutter 7 for the wall surface A, and the center drill 2
It rotates together with the cylindrical body 11 screwed on. At the open end of the cylindrical body 11, a second
A stopper 14 is provided to protrude outward to prevent the punching cutter 12 from falling off toward the opening.
Further, a male threaded portion 10 is provided protruding in the axial direction near the tip corresponding to the other end of the cylindrical body 11.
A compression coil spring 9 is attached between the cylindrical body 11 and the wall of the second perforation cutter 12 by a washer 15 attached to the cylindrical body 11 and a nut 16 screwed thereto. Since the second punching cutter 12 has such a structure, when the cutter is assembled with the cylinder body 11, the stopper 14 of the cylinder body 11 moves the cutter into the opening by the compressed elastic force of the compression coil spring 9. It is locked at the bottom to prevent the cylinder from falling off.

As shown in FIG. 1, when the second drilling cutter 12 is attached to the center drill 4 together with the cylindrical body 11, even if a drilling force is applied to the wall B side in the direction of the arrow, that is, in the left direction in the drawing, The compression coil spring 9 acts as a buffer against the cutter blade 5 of the second punching cutter 12, and the relaxed force acts on the wall surface B, so that edge chipping is less likely to occur even in brittle concrete. Therefore, the second perforation cutter 1
2, the careful drilling work from the wall surface B side can be easily performed. Therefore, the operator on the drill body 1 side cannot be seen. This means that satisfactory drilling work can be performed without looking at the wall surface B side.

In the figure, 17 is a retaining pin.

Next, how to use the punch cutter device will be explained.

First, with only the first drilling cutter 7 attached to the cutter attachment part 3 of the center drill 2 attached to the drill body 1, start drilling with the center drill 2 from the wall surface A side at the center of the concrete wall 13 where the hole is to be drilled. and pass through small hole C.
By further advancing the blade portion 4 of the drill, the cutter blade 5 comes into contact with the wall surface A, and the drilling cutter 7 starts drilling the hole D. Concrete chips generated during drilling are removed from the chip discharge groove 6.
It is discharged along the wall surface A side, and smooth drilling is performed.

Next, the operation of the drill body 1 is stopped at a predetermined position during the drilling, the drilling is temporarily interrupted, and the second drilling cutter 12 incorporating the cylindrical body 11 is screwed onto the tip portion of the center drill 2 protruding toward the wall surface B side.
Alternatively, the cylindrical body 11 is screwed onto the tip of the center drill 2, and the second drilling cutter 12 is further fitted into the cylindrical body 11 so that the cutter blade 5 faces the wall surface B. Adjust the nut 16 so that the end face of the cutter blade 5 comes into close contact with the wall surface B, and press it loosely with the compression coil spring 9. Then, by restarting the operation of the drill body 1 and retracting the drill body 1, the drilling cutter 12 starts drilling from the wall surface B side, first starting from the wall surface A side on the concrete wall 13.
A predetermined hole D is penetrated in communication with the hole D that is drilled halfway through. In this case, center drill 2 and
Since it rotates concentrically with the punching cutter 12, no misalignment occurs in the hole D. Also, as mentioned above, wall surface B
Although the hole cannot be seen because the operator is on the wall A side across the concrete wall 13, the cutter blade 5 of the second punch cutter 12 comes into contact with the wall B via the compression coil spring 9, so there is no edge chipping. less likely to occur.

In the present invention, the second drilling cutter 12 can be attached and detached using the center drill 2 as one bolt, and the cylindrical body 11 can be assembled into the second drilling cutter 12 in advance.
2 can be attached and detached instantly.

According to the present invention, the first
The drilling cutter is easy to install, and the second drilling cutter can be easily attached and removed by using the center drill blade as a kind of bolt, making the device easy to handle and eliminating edge chips on the side of the wall that is not visible to the operator. It has the advantage of being able to drill holes accurately and quickly without causing any damage.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the working form of an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken from FIG. 1...Drill body, 2...Center drill, 3
...Cutter attachment part, 4...Threaded blade part, 5...
... cutter blade, 6 ... groove for discharging chips, 7 ... first punching cutter, 8 ... screw hole, 9 ... compression coil spring, 10 ... male threaded part, 11 ... cylindrical body, 12 ...
...Second perforation cutter, 13...Concrete wall,
14... Stopper, 15... Washer, 16... Nut, 17... Stopping pin, A... Wall surface, B... Wall surface, C... Small hole, D... Hole.

Claims (1)

[Scope of utility model registration request] A first punching cutter 7 having a cutter blade 5 at one end is attached to a cutter mounting portion 3 provided at the base of the center drill 2, so that the threaded blade portion 4 of the drill protrudes from the tip surface of the punching cutter and is connected to the drill. Attaches removably so that it rotates as one,
A cylindrical body 11 having a threaded hole 8 at one end with a female thread corresponding to the protruding thread-like blade part 4 and capable of being screwed onto the drill is provided on the outside thereof, facing the first drilling cutter 7. A second punching cutter 12 having the same outer diameter and substantially the same shape as the first punching cutter 12 and having a cutter blade 5 having a cutting edge direction different from that of the first punching cutter 7 on the opposite end surface is provided near the tip of the cylindrical body 11. Drilling in a concrete wall, etc., characterized in that the drill is detachably attached to the cylindrical body so as to be elastically slidable along the cylindrical body by a compression coil spring 9 and to rotate together with the drill and the cylindrical body. Cutter device.