JPH0522682U - Ring bit - Google Patents

Abstract

(57) [Summary] [Purpose] Providing ring bits with improved discharge of shavings. [Structure] A cylindrical ring bit 1 has an annular end surface 4
It comprises a bit body 2 and a shank 3. The annular end surface 4 has two inclined surfaces 4a and 4b forming a convex shape, and these inclined surfaces 4a and 4b each have an outer peripheral tip 5 and an inner peripheral tip 5 having substantially conical cutting edge portions 5a and 6a, respectively. The peripheral chip 6 is implanted. On the outer peripheral side surface of the bit body 2, the first dust-removing grooves 7 and the guide chips 8 are alternately arranged between the outer peripheral chips 5. The inner peripheral side chips 6 provided to face the guide chips 8 are half of the outer peripheral side chips 5, and a second concave portion 9a and an inclined groove 9b are provided between the inner peripheral side chips 6. The milled powder discharge groove 9 is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The ring bit of the present invention is particularly improved so that the outer peripheral side tip and the inner peripheral side tip provided on the annular end surface function effectively.

[0002]

[Prior Art]

 Conventionally, this kind of ring bit has a chisel-shaped chip with a V-shaped protruding edge part that is implanted in a radial mounting groove, and the inner part is 3-5 mm thick for positioning this tip. The support ring is arranged. Then, the thickness portion of the support ring forms a gap to discharge the powder.

[0003]

[Problems to be solved by the device]

 Therefore, in the ring bit equipped with the chisel-shaped tip described above, the discharge of the powder is not fully functioned, and part of it is discharged to the outer peripheral side, which makes it difficult to rotate, which causes the drilling efficiency. Had a problem that

In view of the above, the present invention intends to provide a ring bit in which the outer peripheral side tip and the inner peripheral side tip are respectively arranged so as not to reduce the drilling efficiency.

[0005]

[Means for Solving the Problems]

 The present invention has been made in view of the above-mentioned points, and the annular end surface of the bit body has an outer peripheral side tip having a substantially cone-shaped cutting edge portion and an inner peripheral side located between every two outer peripheral side tips. This is an improvement on the premise of the ring bit that was prepared.

That is, with respect to the outer peripheral blade tip, the first milled powder discharge groove and the guide tip extending in the axial direction are alternately arranged on the outer peripheral side surface between them. This is to improve the dischargeability of the powder and the guiding effect on the hole wall.

Further, for the inner peripheral side chip facing the guide chip, a second powder-removal discharge groove is formed on the inner peripheral side surface between them so as to face the first powder-removal discharge groove. It is designed to be placed. This is to make it easier to discharge the powder from the inner peripheral side surface. In this case, it is appropriate that the second powder-removing groove is composed of a small recess extending in the radial direction on the annular end surface side and an inclined groove extending on the inner peripheral side surface. Further, it is effective if the annular end surface of the bit body is formed as an inwardly convex inclined surface and the outer peripheral side tip and the inner peripheral side tip are implanted so as to be orthogonal to these two inclined surfaces.

[0008]

[Action]

 The ring bit of the present invention mainly discharges the powdered powder to the outer peripheral side chip by the first powdered powder discharge groove, and guides the hole wall by the guide chip. Furthermore, since the number of the chips on the inner peripheral side is half that of the chips on the outer peripheral side, the second powder-removal discharge groove can be formed large, so that the powder-removal discharge from the inner peripheral side surface can be favorably performed.

[0009]

【Example】

 An 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 composed of a cylindrical bit body 2 and a shank 3, and an annular end surface 4 of the bit body 2 has an outer peripheral tip made of cemented carbide. 5 and the inner peripheral side chip 6 are respectively implanted. In the illustrated case, the annular end surface 4 is composed of two inclined surfaces 4a and 4b having a convex shape, and the substantially conical cutting edge portions 5a and 6a are formed so as to be orthogonal to these inclined surfaces 4a and 4b, respectively. The formed outer peripheral side chip 5 and inner peripheral side chip 6 are implanted. Therefore, the number of the inner peripheral side chips 6 is half that of the outer peripheral side chips 5, and two chips are arranged every other space.

Further, on the outer peripheral side surface of the bit main body 2, a first chipping 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 consideration the discharge of powder from the outer peripheral side surface of the ring bit 1 and the guide action for the hole wall.

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

In the present embodiment, the outer peripheral side tip 5 and the inner peripheral side tip 6 have the cutting edge portions 5a, 6a of the one-step conical shape with the tip portions cut off. A bell-shaped cone with a bulge or the like can also be applied.

[0014]

[Effect of the device]

 According to the present invention, as described above, the outer peripheral side chip 5 and the inner peripheral side chip 6 are embedded in the annular end surface 4 of the bit body 1, and the first and second reflow powder discharge grooves 7 and 9 and the guide chip 8 are taken into consideration. Thus, the outer peripheral side tip 5 and the inner peripheral side tip 6 can be effectively perforated by the cutting edge portions 5a, 6a. In other words, the dischargeability of the powder is improved, the cause of the rotation jam is eliminated, and the presence of the guide tip 8 ensures that the guiding action on the hole wall is also maintained, which improves the drilling efficiency and the tool life. Can be expected to be extended.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a ring bit of the present invention.

FIG. 2 is a vertical cross-sectional view in a partially broken state.

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

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

[Explanation of symbols]

 1 Ring Bit 2 Bit Main Body 3 Shank 4 Annular End Surface 4a, 4b Inclined Surface 5 Outer Circumferential Tip 5a Blade Edge Part 6 Inner Circumferential Tip 6a Blade Edge Part 7 First Milling Powder Discharge Groove 8 Guide Chip 9 Second Milling Powder Discharge Groove 9a small recess 9b inclined groove

Claims (3)

[Scope of utility model registration request] 1. An annular end surface 4 of a bit body 2 having a cylindrical shape.
In the circumferential direction, the cutting edge portions 5a, 6a having a substantially conical shape.
The outer peripheral side chip 5 and the inner peripheral side chip 6 which are projected respectively are implanted, and the inner peripheral side chip 6 is located between every two outer peripheral side chips 5, With respect to the outer peripheral side chips 5, first powder-removing grooves 7 extending in the axial direction and guide chips 8 are alternately arranged on the outer peripheral side surface between them, and the inner peripheral surface facing the guide chips 8 is arranged. A ring bit, characterized in that a second chipping discharge groove 9 is positioned on the inner side surface between the side chips 6 so as to face the first powdering discharge groove 7. 2. The annular end surface 4 according to claim 1 is composed of medium-convex inclined surfaces 4a and 4b, and the outer peripheral side chip 5 and the inner peripheral side chip 6 are planted so as to be orthogonal to the inclined surfaces 4a and 4b. Ring bit embedded. 3. The second powder-removing groove 9 according to claim 1.
The ring bit according to claim 1 or claim 2, wherein the ring bit comprises a small recessed portion 9a extending in the radial direction on the annular end face side and an inclined groove 9b extending on the inner peripheral side face side.