JPH0819911A - Drill - Google Patents

Abstract

PURPOSE:To provide a drill capable of efficiently carrying out cutting, high in cutting ability and capable of smoothly discharge cutting chips. CONSTITUTION:A diagonal continuous groove 23 makes contact with diagonal 19 of a pyramid part 17. The diagonal continuous groove 23 if formed on the side in the rotational direction of a drill 11 with diagonal 21 as a boundary. Additionally, the diagonal continuous groove 23 is extended to the middle of a prism part 15 and makes contact with the diagonal 21. As the diagonal continuous groove 23 is formed on the drill 11, a rake angle alpha of a cutting edge 22 is set as -30 degrees. Furthermore, as the diagonal continuous groove 23 is formed, a contact area with an article to be cut becomes small. Consequently, cutting resistance of the drill 11 becomes small, and cutting ability is improved. Additionally, cutting chips are discharged through the diagonal continuous groove 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drill used for metalworking, crushing taps broken in screw holes, drilling concrete, and the like.

[0002]

2. Description of the Related Art A conventional drill 1 is shown in FIGS. In the figure, reference numeral 3 indicates a holding unit,
The holding portion 3 is formed with a hexagonal prism-shaped prism portion 5 continuously. A pyramid portion 7 is integrally formed at the tip of the prism portion 5, and the six pyramids 9 are formed on the pyramid portion 7.
The pyramid portion 7 is formed with six cutting edges 12 each having six twill 9 as a tip. The traverses 9 of the pyramidal portion 7 are continuous with the traverses 11 of the prismatic portion 5, respectively. This drill 1
Is mounted on a milling machine or the like, rotates in a counterclockwise direction on the paper surface indicated by an arrow in FIG. 14, and the cutting blade 12 cuts and drills a workpiece. The rake angle α of the cutting blade 12 is −
It is 60 degrees.

[0003]

However, in the above-mentioned conventional drill 1, the rake angles α of the six cutting edges 12 are all set at −60 degrees and have sufficient strength, but the cutting resistance is large. There is a possibility that efficient cutting cannot be performed depending on the thickness of the workpiece and the type of the workpiece.
In addition, there is a problem that it is not possible to discharge cutting chips smoothly. The present invention has been made in view of the above conventional problems, and it is an object of the present invention to provide a drill which can perform efficient cutting, has high cutting ability, and can smoothly discharge cutting waste. To aim.

[0004]

According to a first aspect of the present invention, there is provided a holding portion, a prism portion formed on the holding portion, and a pyramidal portion formed at an end portion of the prism portion and having a plurality of traverses. A drill having a plurality of cutting edges each having a tip of each of the pyramid portions, and a twill contact groove that is in contact with at least one of the plurality of the pyramid portions has the twill as a boundary. The drill is characterized in that it is formed on the rotation direction side.

A second aspect of the present invention is the drill according to the first aspect, wherein the traverse contact groove extends to the holding portion.

[0006]

According to the invention of claim 1, the twill contact groove which is in contact with at least one of the plurality of twills of the pyramid portion is formed on the rotational direction side with the twill as a boundary. The rake angle of the cutting edge having the twill formed as the tip is small, and the cutting resistance of the cutting edge is reduced. Further, since the traverse contact groove is formed, the contact area with the object to be cut is reduced and cutting resistance is reduced.
In addition, cutting chips are discharged through the cross groove.

According to the second aspect of the present invention, since the traverse contact groove extends to the holding portion, the cutting waste is discharged more reliably.

[0008]

Embodiments of the present invention will be described with reference to the drawings. 1 to 2 show a drill 1 according to a first embodiment.
1 will be described. The drill 11 is made of a cemented carbide or a powdered HSS sintered material. The drill 11 is mounted on a milling machine or the like, and is rotated in a counterclockwise direction on the paper surface indicated by an arrow in FIG.

Reference numeral 13 denotes a cylindrical holding portion, and a hexagonal prism portion 15 is integrally formed on the holding portion 13. A pyramid part 17 is integrally formed at the tip of the prism part 15, and six twills 19 are formed on the pyramid part 17. The pyramid portion 17 is formed with six cutting edges 22 each having six twills 19 as the tips. The traverses 19 of the pyramidal portion 17 are continuous with the traverses 21 of the prismatic portion 15, respectively.

Reference numeral 23 indicates a traverse continuous groove, and the traverse continuous groove 23 is in contact with the traverse 19 of the pyramid portion 17. Twill continuous groove 23
Are formed on the rotation direction side of the drill 11 with the twill 21 as a boundary. Further, the twill continuous groove 23 extends to the middle of the prismatic portion 15 and is in contact with the twill 21. Since the traverse continuous groove 23 is formed in the drill 11, the rake angle α of the cutting edge 22 is
However, it is smaller than that of the drill 1 according to the conventional example, and the rake angle α of the cutting edge 22 is set to −30 degrees. Further, since the traverse continuous groove 23 is formed, the contact area with the object to be cut is also reduced. Therefore, the cutting resistance of the drill 11 is reduced, and the cutting ability is improved. Further, cutting chips are discharged through the traverse continuous groove 23.

A drill 31 according to a second embodiment will be described with reference to FIGS. 3 to 4. The configuration of the drill 31 is the same as that of the drill 11 according to the first embodiment except that the discharge groove 33 is formed. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment. The description is omitted here. The discharge grooves 33 are formed at two places. Since the drill 31 is formed with the discharge groove 33, the cutting chips are discharged not only through the traverse continuous groove 23 but also through the discharge groove 33. Therefore, it is possible to discharge the cutting waste more efficiently and reliably.

A drill 41 according to a third embodiment will be described with reference to FIGS. The drill 41 is made of a cemented carbide or a powdered HSS sintered material. The drill 41 is mounted on a milling machine or the like, and is rotated in a counterclockwise direction on the paper surface indicated by an arrow in FIG. Reference numeral 43 denotes a columnar holding portion, and a hexagonal prism portion 45 is formed integrally with the holding portion 43. A pyramid portion 47 is integrally formed at the tip of the prismatic portion 45, and five twills 49 and 50 are formed on the pyramid portion 47.

Reference numeral 48 denotes a groove, which is formed continuously from the pyramid portion 47 to the prism portion 45 from the rotation axis L. The groove 48 is cut deeper than the rotation axis L. Five pyramids 49 or 50 on the pyramid 47,
Five cutting blades 52 and 55 are formed as sharp points. The traverses 49 and 50 of the pyramid portion 47 are the six traverses 5 of the prism portion 45.
It is continuous to 5 twill 51 of 1 each.

Reference numeral 53 indicates a traverse continuous groove, which is in contact with the two traverses 50 and is formed on the side of the traverse 50 in the rotating direction of the drill 41. Further, the traverse continuous groove 53 extends to the middle of the prismatic portion 45 and is in contact with the traverse 51.

In the drill 41, the rake angle α of the cutting blade 55 having the two traverses 50 in contact with the traverse contact groove 53 as the tips is
It becomes smaller than that of the cutting blade 52 having the other twill 49 as the tip, and the rake angle α of the cutting blade 22 is set to −30 degrees. Further, since the traverse continuous groove 53 is formed, the pyramidal portion 4
7 also has a small contact area with the workpiece. Therefore, the cutting resistance of the drill 41 is reduced and the cutting ability is improved. Further, cutting chips are generated in the groove 48 and the twill continuous groove 53.
Is discharged through.

In the drill 41, a groove 48 is formed.
Since the vertex 54 is offset with respect to the rotation axis L, the drill 4
When 1 rotates, the apex 54 deviates from the rotation axis L that is substantially non-rotating, and turns around the rotation center. Therefore, the object to be cut can be efficiently cut.

A drill 61 according to a fourth embodiment will be described with reference to FIGS. The configuration of the drill 61 is the same as that of the drill 41 according to the third embodiment except that the discharge groove 63 is formed. Therefore, the same reference numerals as in the third embodiment denote the same structural parts as those in the third embodiment. The description is omitted here. The discharge grooves 63 are formed at two places. Since the drill 61 is formed with the discharge groove 63, the cutting waste is discharged through the traverse continuous groove 53, the groove 48 and the discharge groove 63. Therefore, it is possible to discharge the cutting waste more efficiently and reliably.

A drill 71 according to a fifth embodiment will be described with reference to FIGS. The drill 71 is made of cemented carbide or powdered high-speed sintered material. Drill 71
Is mounted on a milling machine or the like, and is rotated in the counterclockwise direction of the paper indicated by the arrow in FIG. Reference numeral 73 indicates a cylindrical holding portion, and a hexagonal prismatic prism portion 75 is integrally formed on the holding portion 73. A pyramid portion 77 is integrally formed at the tip of the prismatic portion 75, and five twill 79 are formed in the pyramid portion 77.

The pyramidal portion 77 is formed with five twill 79 and five cutting edges 82 with the tips. The twill 79 of the pyramid part 77 is five twill 81 out of the six twill 81 of the prism part 75.
Respectively. Reference numeral 83 indicates a twill continuous groove,
The twill continuous groove 83 is in contact with the twill 79 and is formed on the rotation direction side of the drill 71 with the twill 79 as a boundary. The traverse continuous groove 83 extends to the middle of the prismatic portion 75 and is in contact with the traverse 81.

Reference numeral 85 indicates a cut surface, and the cut surface 85
Are formed by cutting the pyramid portion 77. The cutting surface 85 is constituted by a surface 87 on the outer peripheral side and a surface 89 on the axial center side,
The surface 89 is cut deeper than the rotation axis L. In addition, a V-shaped groove 91 is formed in the cut surface 85, and the groove 91 extends through the cut surface 85.

In the drill 71, the rake angle α of the cutting edge 82 having the twill 79 in contact with the twill contact groove 83 as the tip is smaller than that of the cutting edge 82 having the other twill 79 as the tip, and the cutting edge 82 The rake angle α is set to −30 degrees. Further, since the traverse continuous groove 83 is formed, the contact area of the pyramidal portion 77 with the object to be cut is also small. Therefore, the cutting resistance of the drill 71 is reduced, and the cutting ability is improved. Further, the cutting waste is discharged through the groove 91 and the traverse continuous groove 83.

In the drill 71, the apex 93 is deviated with respect to the rotation axis L. Therefore, when the drill 71 rotates, the apex 93 turns around the rotation axis. Therefore, the cut object can be efficiently cut.

A drill 101 according to a sixth embodiment will be described with reference to FIGS. The configuration of the drill 101 is the same as that of the fifth embodiment except that the discharge groove 103 and the drill 71 according to the fifth embodiment are formed. The description is omitted here. The discharge groove 103 is formed at two places, and the discharge groove 103 communicates with the groove 91. This drill 101
Since the discharge groove 103 is formed, the cutting waste is discharged not only through the traverse continuous groove 83 but also through the discharge groove 103. Therefore, it is possible to discharge the cutting waste more efficiently and reliably.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and even if there is a change in the design without departing from the gist of the present invention, the present invention is not limited to this embodiment. Included in the invention. For example, in the above embodiment, the traverse contact grooves 23, 53, 83 are formed so that the rake angle α is set to -30 degrees, but the present invention is not limited to this, and the rake angle α is 0 degree. The twill contact groove may be formed so as to be changed from −45 degrees to −45 degrees.

Drill 11 and second drill according to first embodiment
The number of the traverse continuous grooves 23 of the drill 31 according to the embodiment is not limited to the above-mentioned number, and may be appropriately changed within the range of one or more to the number of the traverses 19 according to the thickness of the drill, the hardness of the workpiece, and the like. You may. Further, the traverse continuous groove 23 may be formed only in the pyramid portion 17 without extending to the holding portion 15. The discharge groove 33
The size and number of can be changed as appropriate.

The drill 41 and the fourth drill according to the third embodiment
The traverse continuous groove 53 of the drill 61 according to the embodiment is not limited to the one described above, and may be appropriately changed within the range of one or more to the number of the traverses 49 according to the thickness of the drill, the hardness of the workpiece, and the like. Good. Further, the traverse continuous groove 53 may be formed so as not to communicate with the groove 48. Further, the traverse continuous groove 53 may be formed only in the pyramid portion 47 without extending to the holding portion 45. The size and number of the discharge grooves 63 can be changed as appropriate, and the discharge grooves 63 may be formed so as not to communicate with the grooves 48.

Drill 71 and sixth drill according to fifth embodiment
The traverse continuous groove 83 of the drill 101 according to the embodiment is not limited to the above-described one, and in the range of one or more to the number of traverses 79,
It may be changed as appropriate according to the thickness of the drill, the hardness of the workpiece, and the like. Further, the cross groove 83 may be formed so as not to communicate with the groove 91. Further, the traverse continuous groove 83 may be formed only in the pyramid portion 87 without extending to the holding portion 75. Note that the size and number of the discharge grooves 103 can be appropriately changed, and may be formed so as not to communicate with the grooves 91.

[0028]

As described above, according to the drill of the present invention,
Efficient cutting can be performed, the cutting ability is high, and the cutting chips can be discharged smoothly.

[Brief description of drawings]

FIG. 1 is a side view of essential parts of a drill according to a first embodiment of the present invention.

FIG. 2 is a front view of the drill according to the first embodiment of the present invention.

FIG. 3 is a side view of a main part of a drill according to a second embodiment of the present invention.

FIG. 4 is a front view of a drill according to a second embodiment of the present invention.

FIG. 5 is a side view of essential parts of a drill according to a third embodiment of the present invention.

FIG. 6 is a front view of a drill according to a third embodiment of the present invention.

FIG. 7 is a side view of a main part of a drill according to a fourth embodiment of the present invention.

FIG. 8 is a front view of a drill according to a fourth embodiment of the present invention.

FIG. 9 is a side view of a main part of a drill according to a fifth embodiment of the present invention.

FIG. 10 is a front view of a drill according to a fifth embodiment of the present invention.

FIG. 11 is a side view of a main part of a drill according to a sixth embodiment of the present invention.

FIG. 12 is a front view of a drill according to a sixth embodiment of the present invention.

FIG. 13 is a side view of a main part of a conventional drill.

FIG. 14 is a front view of a drill according to a conventional example.

[Explanation of symbols]

 11, 31, 41, 71, 101 Drill 13, 43, 73 Holding section 15, 45, 75 Square column section 17, 47, 77 Pyramid section 19, 49, 50, 79 Pyramid section twill 22, 52, 55, 82 Cut Blade 21, 51 Twill of prismatic part 23, 53, 83 Twill continuous groove 33, 63, 103 Discharge groove 48 Groove 85 Cutting section 87 Outer peripheral surface 89 Shaft center surface 91 Groove L Rotation axis α Rake angle

Claims (2)

[Claims] 1. A holding portion, a prism portion formed on the holding portion, a pyramid portion having a plurality of traverses formed at an end portion of the prism portion, and a traverse of the pyramid portion each having a pointed end. In a drill having a plurality of cutting edges, a twill contact groove that is in contact with at least one of the plurality of twills of the pyramid portion is formed on the rotation direction side with the twill as a boundary. Characteristic drill. 2. The drill according to claim 1, wherein the traverse contact groove extends to the holding portion.