JP2552135Y2 - Ring bit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a ring bit in which the outer peripheral tip and the inner peripheral tip provided on the annular end face are improved so as to function effectively.

[0002]

2. Description of the Related Art Conventionally, a ring bit of this type has a chisel-shaped tip provided with a V-shaped protruding cutting edge portion implanted in a radial mounting groove, and has an inner portion for positioning the tip. A support ring having a thickness of about 5 mm is arranged. The thickness of the support ring forms a gap to discharge the powder.

[0003]

Therefore, in the ring bit provided with the above-mentioned chisel-shaped tip, the discharge of the dust does not function sufficiently, and a part thereof is discharged to the outer peripheral side, so that it is difficult to rotate. Therefore, there is a problem that the drilling efficiency is reduced due to this.

In view of the above, in the present invention, an outer peripheral tip and an inner peripheral tip are provided, respectively, and an attempt is made to provide a ring bit in which the drilling efficiency is not reduced.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and has an outer peripheral tip and an outer peripheral tip each having a substantially conical cutting edge portion on an annular end surface of a bit body. This is an improvement on the premise that a ring bit is provided on the inner peripheral side located between the spaces.

That is, for the outer peripheral tip, the first powder discharge grooves and the guide tips extending in the axial direction are alternately arranged on the outer peripheral side face between them. This is a consideration to improve the discharging property of the powder and the guiding action to the hole wall.

[0007] Further, a second powder discharge groove is positioned on the inner peripheral side face between the inner peripheral chip and the guide chip so as to face the first powder discharge groove. It is intended to be. This is a consideration for smoothly discharging the powder from the inner peripheral side surface. in this case,
Suitably, the second powder discharge groove comprises a small concave portion extending in the radial direction on the annular end surface side and an inclined groove extending on the inner peripheral side surface. Also, it is effective if the annular end face of the bit body is formed on a middle convex inclined surface, and the outer peripheral side chip and the inner peripheral side chip are implanted so as to be orthogonal to the two inclined surfaces.

[0008]

The ring bit of the present invention discharges powder from the outer peripheral tip mainly by the first powder discharge groove and guides the hole wall by the guide tip. Further, since the number of the chips on the inner peripheral side is half that of the chips on the outer peripheral side, the second dust discharge groove can be formed large, so that the discharge of the powder from the inner peripheral side surface can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the ring bit of the present invention will be described below with reference to the drawings.

1 to 4, reference numeral 1 denotes a ring bit comprising a cylindrical bit body 2 and a shank 3, and an annular end face 4 of the bit body 2 has an outer peripheral tip 5 made of cemented carbide. And the inner peripheral tip 6 are implanted. And in the case of illustration, the annular end face 4
Is composed of two inclined surfaces 4a and 4b exhibiting a central convexity. The outer peripheral side tip 5 and the inner tip 5 are formed with substantially conical cutting edge portions 5a and 6a, respectively, so as to be orthogonal to the inclined surfaces 4a and 4b. The peripheral tip 6 is implanted. Therefore, the number of the inner peripheral chips 6 is half the number of the outer peripheral chips 5 and is disposed between every two chips.

Further, on the outer peripheral side surface of the bit main body 2,
A first powder discharge groove 7 extending in the axial direction and a guide chip 8 made of cemented carbide are located between the outer peripheral chips 5. These take into account the discharge of the powder from the outer peripheral side surface of the ring bit 1 and the guiding action on the hole wall.

On the other hand, the inner peripheral chips 6 are half of the outer peripheral chips 5 as described above, and are located so as to face the guide chips 8. A second powder discharge groove 9 is formed between the inner peripheral chips 6. The second powder discharge groove 9 is configured by a small concave portion 9a extending in the radial direction on the annular end face 4 and an inclined groove 9b on the inner peripheral side surface, so that the discharge volume of powder powder can be increased.

In this embodiment, the cutting edge portions 5a and 6a of the outer peripheral tip 5 and the inner peripheral tip 6 have a one-stage conical shape with the leading end portions cut off. Also, a bell-shaped cone with a bulge or the like can be applied.

[0014]

According to the present invention, as described above, the outer peripheral tip 5 and the inner peripheral tip 6 are implanted in the annular end face 4 of the bit body 1, and the first and second powder discharge grooves 7, 9 and the guide are provided. Since the tip 8 is taken into consideration, effective drilling by the cutting edge portions 5a, 6a in the outer tip 5 and the inner tip 6 is possible. That is, the discharging property of the powdered powder is improved, the cause of the occurrence of jamming of the rotation is eliminated, and the presence of the guide chip 8 ensures that the guiding action on the hole wall is maintained, so that the drilling efficiency is improved and the tool life is improved. Can be expected to be extended.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an embodiment of a ring bit according to the present invention.

FIG. 2 is a vertical cross-sectional view of a half-missed state.

FIG. 3 is an enlarged sectional view taken along line AA in FIG.

FIG. 4 is an enlarged sectional view taken along line BB in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ring bit 2 Bit main body 3 Shank 4 Annular end surface 4a, 4b Inclined surface 5 Outer side tip 5a Blade part 6 Inner side tip 6a Blade part 7 First powder discharge groove 8 Guide chip 9 Second powder discharge groove 9a Small recess 9b Inclined groove

Claims (3)

(57) [Scope of request for utility model registration] An annular end face (4) of a bit body (2) having a cylindrical shape.
In the circumferential direction, the edge portions 5a, 6a having a substantially conical shape
The outer peripheral side tip 5 and the inner peripheral side tip 6 are respectively implanted, and the inner peripheral side tip 6 is located between every two outer peripheral side tips 5 in a ring bit. A first powder discharge groove 7 and a guide chip 8 extending in the axial direction are alternately positioned on the outer peripheral side surface between the outer peripheral side chips 5, and the inner peripheral surface facing the guide chip 8 is alternately arranged. A ring bit characterized in that a second powder discharge groove 9 is located on the inner peripheral side surface between the side chips 6 so as to face the first powder discharge groove 7. 2. An annular end face 4 according to claim 1, comprising inclined faces 4a and 4b having a convex center, and the outer peripheral tip 5 and the inner peripheral tip 6 are planted perpendicular to the inclined faces 4a and 4b. Ring bit inserted. 3. The second powder discharge groove 9 according to claim 1.
3. The ring bit according to claim 1, wherein the ring bit comprises a small concave portion 9a extending in a radial direction on an annular end surface side and an inclined groove 9b extending on an inner peripheral side surface.