JP3199122U - Drill that suppresses generation of burrs - Google Patents

Abstract

Provided is a drill for suppressing the generation of burrs, which can prevent the generation of burrs with a very simple shape when drilling holes. A burr is prevented from being formed by forming an R surface 8 having a predetermined size without making the outer peripheral corner of the drill square. [Selection] Figure 1

Description

  The present invention relates to a drill in which burrs are not generated around the exit side of a hole when drilling a through hole.

  When a hole is drilled using a drill, burrs are generated around the outlet side of the hole. Although the size of the burr depends on the material of the workpiece, the burr generated is relatively large when the material is excellent in ductility such as aluminum or steel. On the other hand, in the case of a brittle material such as a casting, the size of the generated burr becomes relatively small, but the generation cannot be completely suppressed.

  A drilling machine is generally used for the drilling process, but in many cases, a drilling is accurately performed at a predetermined place using a computer-controlled machining center. As described above, there are various apparatuses for drilling with a drill attached, but no matter what apparatus is used, burrs generated around the hole cannot be completely suppressed. For this reason, the deburring process is actually performed after the hole process is completed.

However, the deburring process is simple but cumbersome, which requires a special man-hour for deburring.
Conventionally, special tools that can easily perform this deburring are also known. For example, a “deburring tool” according to Japanese Patent Application Laid-Open No. 2009-39842 removes burrs generated at the intersection of a drill hole and a cross hole, enabling fine adjustment of the tool diameter and further removing burrs. Is also stable.
In other words, a slit (split groove) is formed in the part extending from the tip of the head piece having a cutting edge to the middle of the shank part to which the head piece is joined, and at a position facing the slit of the shank part in between, A tool diameter adjusting mechanism using an adjusting screw is provided, and the tool is inserted into a hole having a burr on its inner surface without being rotated, and the burr is pushed out by a cutting blade.

  On the other hand, some drills have been improved to suppress the generation of burrs. For example, a “drill” according to Japanese Patent Application Laid-Open No. 2005-297124 is a drill that can reduce the occurrence of cutting burrs at the workpiece outlet or prevent entanglement of chips in a drilling tool. Therefore, the drill tip has a primary cutting edge, and has a tip half angle θ1 and a flank like a normal drill. The secondary cutting edge is a curve having a concave curve and has a flank. The inclination angle γ2 with respect to the drill axis c at the intersection of the secondary cutting edge and the drill large diameter portion is set to 5 ° to 20 °.

Various techniques relating to drills that suppress the generation of burrs, such as a “burr suppression drill” according to Japanese Patent Laid-Open No. 2005-279848 and a “burr removal drill” according to Japanese Patent Laid-Open No. 2005-246777, are known.
"Deburring tool" according to JP2009-39842A “Drill” according to JP-A-2005-297124 "Burr suppression drill" according to JP-A-2005-279848 "Deburring drill" according to Japanese Patent Application Laid-Open No. 2005-246777

  Thus, there exist tools for removing burrs when drilling holes, or drills that can suppress the occurrence of burrs when drilling holes. The problem to be solved by the present invention is this problem, and provides a drill capable of preventing the occurrence of burrs with a very simple shape.

  For the drill, a material having not only cutting performance but also heat resistance, wear resistance, and toughness is used. Generally, tool steel, super hard alloy, etc. are used, or the characteristics as a drill are improved by quenching, nitriding, coating with titanium, etc. to improve overall performance. As for the basic form and structure, the same as before. That is, the present invention does not limit the drill diameter, tip angle, flank, helix angle, and the like.

  By the way, the drill according to the present invention forms an R surface on the front shoulder (outer corner). The outer peripheral corner of a conventional drill is ground at an acute angle and does not have an R surface. However, the size of the R surface is not particularly limited here, and for this purpose, it can be an R surface close to the C surface with a very large curvature radius.

  The drill according to the present invention is formed by forming an R surface or C surface at the outer peripheral corner of the tip, so that when drilling, the drill is gradually cut from the drill center to the outer diameter portion. Can be suppressed. And by providing the R surface or C surface, the distance of the flat portion at the tip of the drill is shortened. Therefore, the cutting resistance is small, and the accuracy of the drilled hole is suppressed by the fluttering of the drill during drilling. The surface roughness of the hole is improved.

  In addition, the present invention only forms an R surface or C surface of an appropriate size at the outer peripheral corner of the tip portion, and the drill is extremely simple to manufacture, which is a great difference compared to the manufacturing cost of a conventional general drill. There is no. And even if it forms R surface and C surface in an outer periphery corner, there is no influence on durability of a drill.

The Example which shows the drill front-end | tip part which concerns on this invention. A conventional drill tip is shown. The cross-sectional enlarged view which formed R surface in the outer periphery corner of a drill. When burrs occur with conventional drills. When drilling with a drill that has an R-surface at the outer corner.

  FIG. 1 shows an embodiment of a drill tip according to the present invention, and FIG. 2 shows a conventional general drill tip. In the figure, the drill has a diameter D, is spirally twisted at a predetermined twist angle, and the tip is sharp with a predetermined tip angle θ. In the figure, 1 is a cutting edge, 2 is a relief surface, 3 is a rake face, 4 is an outer corner (a shoulder at the tip), 5 is a groove, 6 is a margin, and 7 is a leading edge.

  When drilling using a drill, the chips cut by the tip cutting edge 1 flow along the rake face 3 and are discharged out of the hole machined along the spiral groove 5. A flank 2 is formed at the tip of the blade 1 behind the rotation of the cutting edge 1, and therefore friction at the bottom of the hole is reduced, and a margin 6 having a constant width is provided along the spiral groove 5. Thus, friction with the inner peripheral surface of the hole during drilling can be reduced.

  Although these are general forms as a drill, the drill of the present invention forms an R surface 8 at the outer corner 4 as shown in FIG. That is, the outer peripheral corner 4 has a smooth R surface 8 without being angular, and the cutting edge 1 and the leading edge 7 are continuous via the R surface 8. Here, the R surface 8 is not limited to a curved surface continuous over the entire area of the outer peripheral corner 4, and may be composed of a plurality of R surfaces having different curvatures.

  The radius of curvature of the R plane 8 is not particularly limited. For this reason, if the radius of curvature is very large, the radius becomes close to the C plane. In order to prevent the generation of burrs, the R plane is more suitable than the C plane. However, even when the C plane is formed at the outer peripheral corner 4, an effect of suppressing burrs can be obtained.

  FIG. 3 shows an enlarged cross-sectional view of the outer peripheral corner, but an R surface 8 having a radius of curvature r is formed. When the outer peripheral corner 4 is sharpened as in the prior art, as shown in FIG. 4, when the drill 9 advances and the hole 10 penetrates, the outer peripheral corner 4 is instantaneously passed from the cutting edge 1. Then, the process proceeds to the leading edge 7. The leading edge 7 cannot cut and remove the burrs 11 rising in the same size as the through-holes 10. That is, the burr 11 left uncut by the cutting blade 1 is left as it is.

  FIG. 5 shows the case of drilling using the drill 12 according to the present invention. FIG. 5A shows a state before the drill 12 advances and the hole 10 penetrates, but the hole 10 does not penetrate completely, and the tip of the drill 12 is partially surfaced. If the drill 12 further moves forward, the hatched portion is cut by the cutting edge 1 and the hole 10 penetrates.

  FIG. 5B shows the case where the drill 12 has advanced and the hole 10 has completely penetrated. However, since the R surface 8 is formed at the outer peripheral corner 4, the outside of the cutting edge 1 is curved and leading. It is continuous with the edge 7. That is, before the drill 12 moves forward and the hole 10 penetrates, it is cut by the curved outer portion of the cutting edge 1, and the hatched portion area shown in FIG. It is cut little by little. That is, as the drill 12 advances, the curved outer peripheral portion of the cutting edge 1 moves outward from the center of the hole 10 by forming the R surface 8, so that the generation of burrs 11 is suppressed. .

1 Cutting Edge 2 Flank 3 Rake Face 4 Corner Corner 5 Groove 6 Margin 7 Leading Edge 8 R Surface 9 Drill
10 holes
11 Bali
12 Drill
13 Tip

Claims (2)

The drill which suppresses generation | occurrence | production of a burr | flash at the time of drilling, The drill which suppresses generation | occurrence | production of the burr | flash characterized by forming the R surface or C surface of predetermined magnitude | size in this drill outer periphery corner. The drill which suppresses generation | occurrence | production of the burr | flash of Claim 1 which formed several R surface from which a curvature radius differs in the said outer periphery corner.