JPH0631545A - Manufacture of core drill for concrete - Google Patents

Abstract

PURPOSE:To improve durability and safety by increasing fixation strength and improve workability by improving heat resistivity. CONSTITUTION:When a plurality of grinding chips 3,... are fixed at regular intervals on the top edge surface 2s of a cylindrical bit shank 2, the chips 3,... are attached to the top edge surface 2s of the bit shank 2, which is relatively revolved at a prescribed speed. The radiation direction and radiation position are inclined in an angle of nearly 0-17 deg. in the axial direction Hs for the radial direction Hd of the bit shank 2, and the laser beam C having a prescribed output which passes through the contact surfaces W between the top edge surface 2s of the bit shank 2 an the chips 3,... is radiated on the outer peripheral surface 2e of the bit shank 2, and the chips 3,... are welded on the top edge surface 2s of the bit shank 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a concrete core drill in which a plurality of cutting tips are fixed to a tip end surface of a cylindrical bit shank at regular intervals.

[0002]

2. Description of the Related Art Generally, a core drill for concrete is used for making holes in concrete, asphalt, bricks, stones and the like. This type of core drill is provided with a cylindrical bit shank and a plurality of chips, and at the time of manufacture, a plurality of chips are fixed to the entire circumference of the tip surface of the bit shank by brazing at regular intervals.

However, in such a conventional manufacturing method, since the bit shank and the chip are fixed by brazing, there are the following problems.

First, since the strength of fixing the chips cannot be increased, the chips may come off during use, resulting in poor durability and safety. In particular, the wall thickness of the bit shank in recent years tends to be thin along with the demand for lighter weight and higher rotation speed, so the fixing area becomes smaller, and this problem is large.

Secondly, since it is weak against heat and the chip peels off at about 350 ° C., it is necessary to use it while pouring water, and the workability is poor.

The present invention has solved the problems existing in the prior art as described above. The durability and safety are improved by increasing the fixing strength, and the workability is improved by increasing the heat resistance. An object of the present invention is to provide a core drill for concrete that can be used.

[0007]

According to the method of manufacturing a core drill for concrete according to the present invention, when a plurality of cutting tips 3 ... Are fixed to a tip end surface 2s of a cylindrical bit shank 2 at regular intervals, the bit shank. The tip 3 is brought into contact with the tip end surface 2s of the 2 and the bit shank 2 is moved at a predetermined speed.
For example, the outer peripheral surface 2e is relatively rotated at a speed selected in the range of approximately 0.5 to 4.5 m / min, and the irradiation direction and the irradiation position are substantially in the axial direction Hs with respect to the radial direction Hd of the bit shank 2. A laser beam C that is inclined at an angle Q of 0 to 17 ° and passes through the contact surface W between the tip surface 2s of the bit shank 2 and the tips 3 ...
The tip 3 is welded to the tip surface 2s of the bit shank 2 by irradiating the outer peripheral surface 2e of the bit shank 2 with the laser beam C selected in the kw range.

[0008]

According to the method of manufacturing a core drill for concrete according to the present invention, a laser beam C emitted from a laser beam machine or the like when fixing a plurality of chips 3 to the tip surface 2s of the bit shank 2 is By welding the bit shank 2 and the chips 3 to the portion to be fixed, welding by the laser beam C is performed.

In this case, the tip surface 2s of the bit shank 2 is
The chips 3 are brought into contact with each other, the bit shank 2 is relatively rotated at a predetermined speed, and the laser beam C is irradiated at a predetermined angle, a predetermined position, and a predetermined output condition. That is, considering the material and size of the tip 3, the bit shank 2
At a speed of the outer peripheral surface 2e of about 0.5 to 4.5 m / min, and an irradiation angle and an irradiation position of the laser beam C in the axial direction Hs with respect to the radial direction Hd of the bit shank 2 are approximately 0 to 0 m.
It is inclined at an angle of 17 ° and passes through the tip surface 2s of the bit shank 2 and the contact surface W of the chips 3 ... And the output of the laser beam C is in the range of approximately 1.0 to 5.0 kw. Select. As a result, welding is performed under optimum conditions, and bond strength and heat resistance are enhanced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, in order to clarify the method of the present invention, the structure of the core drill 1 for concrete will be described with reference to FIG.

From the top of the core drill 1, the adapter portion 11,
The bit shank 2 in which the tube portion 12 and the T shank portion 13 are sequentially coaxially connected is provided. These adapter portion 11, tube portion 12 and T shank portion 13 are made of carbon steel pipe (JIS, STKM-S45C, STKM-13C).
Etc.) are cut into a predetermined length and used.

Further, the adapter portion 11 has a tubular portion 11a coupled to the tube portion 12 and an end face portion 11 integral with the tubular portion 11a.
b and the mounting portion 11 integrally mounted at the center of the end surface portion 11b
It consists of c. It should be noted that the tube portion 12 is one in the embodiment, but a plurality of tube portions are sequentially connected and used depending on the depth of the hole to be formed.

Furthermore, the mounting portion 11c is attached to and detached from the rotary output shaft Eo of the rotary drive device E shown by phantom lines. Device E
Is equipped with a drive motor, a forward / backward feed mechanism, and the like. The device E has conventionally been provided with a cooling device for sending cooling water to the core drill side, but when the core drill 1 manufactured by the method of the present invention is used, it is not always necessary to provide the cooling device.

On the other hand, the bit shank 2 (T shank portion 1
A plurality of cutting chips 3 ... Are fixed to the tip surface 2s of 3) at regular intervals. The chips 3 ... Are, for example, rectangular parallelepiped small blocks obtained by mixing diamond particles with a binder and sintering the mixture.

Next, a method for manufacturing a core drill for concrete according to the present invention will be described with reference to FIG.

First, a cylindrical bit shank 2 and a plurality of chips 3 ... Are prepared. The bit shank 2 and the chips 3 ... Can be manufactured by a method similar to the conventional method.

Then, according to the method of the present invention, the chips 3 are fixed to the entire circumference of the tip surface 2s of the bit shank 2 at regular intervals.

First, the bit shank 2 and the chips 3 are set on a predetermined jig, and the tips 3 are brought into contact with the tip end surface 2s of the bit shank 2 at regular intervals to move the bit shank 2 at a predetermined speed, that is, , The outer peripheral surface 2e of the bit shank 2 is relatively rotated at a speed selected in the range of approximately 0.5 to 4.5 m / min.

Then, the laser beam C radiated from the laser processing machine M or the like is applied to the portion where the bit shank 2 and the chips 3 are to be fixed to each other, whereby welding (laser welding) by the laser beam C is performed. At this time, the irradiation direction and the irradiation position of the laser beam C are inclined with respect to the radial direction Hd of the bit shank 2 in the axial direction Hs at an angle Q of approximately 0 to 17 °, and the tip surface 2 s of the bit shank 2 and the tip 3 are.
A position P passing through the contact surface W of ... Is selected.

The light quantity of the laser beam C at this time, that is, the output of the laser beam C from the laser processing machine M or the like is selected in the range of approximately 1.0 to 5.0 kw.

The rotational speed of the bit shank 2 at the time of welding, the irradiation direction and irradiation position of the laser beam C, and the output of the laser beam C are determined under the above conditions by considering the material and size of the tip 3. Select.

As a result, the tips 3 are sequentially welded to the entire circumference of the tip surface 2s of the bit shank 2. The core drill 1 for concrete manufactured by such a method,
As compared with the conventional brazing method, the fixing strength can be increased to about twice. In addition, the heat resistance is significantly improved, and for example, in the past, cooling by water injection was always required during use (during cutting), but the core drill 1 manufactured by the method of the present invention is operated in a dry state without water injection. Therefore, the workability can be greatly improved.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, the bit shank is rotated during welding, but the laser beam C side may of course be rotated. In addition, the detailed configuration, shape, method, and the like can be arbitrarily changed without departing from the scope of the present invention.

[0025]

As described above, in the method for manufacturing a concrete core drill according to the present invention, when a plurality of cutting chips are fixed to the tip surface of a cylindrical bit shank at regular intervals, the tip surface of the bit shank is fixed. Abut the tip,
While rotating the bit shank relatively at a predetermined speed,
The irradiation direction and irradiation position are inclined at an angle of approximately 0 to 17 ° in the axial direction with respect to the radial direction of the bit shank, and a laser beam with a predetermined output that passes through the tip surface of the bit shank and the contact surface of the chip is generated. By irradiating the outer peripheral surface of the shank to weld the tip to the tip surface of the bit shank, the following remarkable effects are obtained.

Since the fixing strength of the chip can be doubled as compared with the conventional method, by preventing the chip from separating during use, durability and safety can be greatly improved.

Since the heat resistance can be increased, it is not necessary to inject water during use, and workability can be greatly improved.

[Brief description of drawings]

FIG. 1 is an operation explanatory view for explaining a manufacturing method according to the present invention,

FIG. 2 is a partial cross-sectional front view of a core drill for concrete manufactured by the manufacturing method,

[Explanation of symbols]

 2 Bit shank 2s Tip surface 2e Outer peripheral surface 3 Tip Q Angle Hd Radial direction Hs Axial direction W Contact surface C Laser beam

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[Procedure amendment]

[Submission date] April 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

From the top, the core drill 1 is attached to the adapter unit 1.
1, a tube portion 12 and a T shank portion 13 are sequentially provided with a bit shank 2 coaxially connected to each other. These adapter portion 11, tube portion 12 and T shank portion 13 are made of carbon steel pipe (JIS, STKM-S45C, STKM-13).
C or the like) or low carbon metal such as SUS301 is cut into a predetermined length and used.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

On the other hand, a plurality of cutting chips 3 ... Are fixed to the tip surface 2s of the bit shank 2 (T shank portion 13) at regular intervals. The chips 3 ... Include, for example, a binder made of diamond particles (Co, Fe, Cu, Ni, Bz).
Etc.) is a small rectangular parallelepiped block mixed with and sintered.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of symbols] 2-bit shank (low carbon metal) 2s Tip surface 2e Outer peripheral surface 3 Chip (Co, Fe, Ni, Cu, Bz) Q Angle Hd Radial direction Hs Axial direction W Contact surface C Laser beam

Claims (3)

[Claims] 1. When a plurality of cutting tips are fixed to the tip surface of a cylindrical bit shank at regular intervals, the tips are brought into contact with the tip surface of the bit shank and the bit shank is relatively rotated at a predetermined speed. , The irradiation direction and the irradiation position are inclined at an angle of approximately 0 to 17 ° in the axial direction with respect to the radial direction of the bit shank, and a laser beam of a predetermined output that passes through the tip surface of the bit shank and the contact surface of the chip,
A method for manufacturing a core drill for concrete, characterized in that a tip is welded to the tip surface of the bit shank by irradiating the outer peripheral surface of the bit shank. 2. The method for manufacturing a concrete core drill according to claim 1, wherein the predetermined speed is selected such that the speed of the outer peripheral surface of the bit shank is in the range of about 0.5 to 4.5 m / min. 3. The method for producing a core drill for concrete according to claim 1, wherein the predetermined output is selected within a range of approximately 1.0 to 5.0 kw.