JPS6268213A - Drill - Google Patents

Abstract

PURPOSE:To increase rigidity of a drill and to promote the high efficiency of its drilling, by protruding the outside end part of a cutting part heel surface into a chip discharge groove while an edge reverse face in almost a triangular shape toward the discharge groove in the drill axial direction section. CONSTITUTION:A drill forms an outside end part 5b of a heel surface 5 to a large thickness while a protruding part 4c in an edge reverse face 4 to a large thickness. Accordingly, the drill enables its rigidity to be improved with no necessity for increasing a web thickness to a large value. While the drill, providing a recessed part 5a in the heel surface 5, decreases the web thickness smaller than that of a standard drill 3 and a high rigidity drill 2, and when dressing is performed, the drill, decreasing also a chisel edge accordingly cutting resistance, improves the cutting property.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a drill, and more particularly, to a drill that does not require fragrant wood.

BACKGROUND OF THE INVENTION Conventionally, in order to increase the efficiency of drilling holes with a drill, the rigidity of the drill has been increased. Of course, this drill 2 with increased rigidity
As shown in FIG. 1, in the cross-section of the blade in the direction perpendicular to the drill axis, the back surface 2b and heel surface 2c of the blade are formed thicker than the mark hetrile 3 shown by the dotted line 3 in the figure, and the core thickness is increased. is made larger to provide rigidity.

However, the problem that the invention is trying to solve is that the above structure has a diameter of 1'7, so the cutting edge is larger than that of the drill 3 and 6. As a result, the cutting resistance increases and machinability deteriorates, making it necessary to accurately perform thinning over a relatively wide 11iii area as indicated by diagonal lines in Figures 15, 16, and 17. However, there is a problem that the hole brightness affects accuracy. However, this thinning has to be performed during the re-grinding fIj, and there is a problem that it is complicated. Furthermore, as the core thickness increases, the cross-sectional area of the chip ejection groove increases to (:t[j l
There was a problem when it became smaller than Rir 3 and the chip ejection performance deteriorated.

Therefore, an object of the present invention is to provide a drill that can have a rigidity of 1-minute even if the core thickness is small and can hold a relatively large chip ejection groove.

Means for Solving the Problems In order to achieve the object, the present invention does not directly sharpen the core 12, but rather the outer edge of the heel surface and the blade with respect to the standard cross-sectional blade shape. When the back surface is made to protrude, the center side of the heel surface is depressed, and as a result, the rigidity of the drill can be improved.

That is, for a standard cross-sectional blade shape in which the heel surface and the back surface of the blade that constitute the chip ejection groove form a roughly smooth curved surface in the axial cross-section of the drill, the outside edge of the heel surface is different from the heel surface of the standard cross-sectional blade shape. The part protrudes into the chip ejection groove, and the center side of the heel surface from the heel surface of the standard cross-section blade shape has a roughly U-shape. The approximately triangular cross-sectional shape protruding toward the discharge groove is reduced, and the tip is configured to have a punching hole.

Effect of the Invention In the above configuration, in the trill axial cross section, the outer end of the heel surface of the blade protrudes into the chip ejection groove, while
The back surface of the blade protrudes in a substantially triangular shape toward the chip ejection i1η, increasing the trill rigidity, and the center side of the heel surface is concave in an abbreviated shape, reducing the core thickness.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an end view of the blade portion of the drill l according to this embodiment, and in the figure, the dotted line indicates a substantially smooth curved surface where the heel surface 3b and the blade back surface 3a forming the chip ejection groove are approximately smooth in the axial cross section of the drill. A standard trill 3 having a standard cross-sectional blade shape is shown, and the two-dot chain line shows a large high-rigidity trill 2 with a conventional core [7]. Further, Fig. 3゜21.5 shows a blade tip surface and a cross-sectional side view of the trill according to this embodiment, and a cross-sectional view taken along the line A-A in Fig. 1. It is formed point-symmetrically around the central axis O point in Figure 1.
A pair of chip ejection grooves 6, 6 are formed, and a blade back surface, *1, and a heel surface 5 are provided on the d4 wall of each curved depth ejection groove 6, respectively.

The back surface 4 of the blade is made thicker than the standard trill 3 by forming a protruding portion 1 c in a cross section in the axial direction of the drill, in a substantially triangular shape protruding into the chip ejection groove 6 from the triangular trill 3. That is, while the outer side 4a of the back surface of the blade 1 protrudes like the conventional high-rigidity drill 2, the center side = i b is more rounded than the center side 4b of the high-rigidity drill 2 and has a smaller core thickness. In addition, in the axial cross section of the drill J- marked heel surface 5, its outer end 5b is drained into a depth similar to the high-rigidity drill 2): ? When protruding into the inside of f 6, a U-shaped four part 5a is formed from the outer end 51) toward the center, and the outer end 5b is thicker than the marking trill 3, while the center On the side, the core thickness is made smaller by making it easier than the high-rigidity drill 2 and the marker C (drill 3).The core thickness part is parallel to the drill axis direction (0/100).

Therefore, chips generated by cutting with the drill 1 are guided into the chip ejection groove 6 along the curved surface of the outer side 4a of the substantially triangular protrusion 4C on the back surface 4 of the blade, and are properly ejected.

FIG. 2 shows a specific example of the drill for steel, which is the drill 1 according to the above embodiment. 21117 width ratio is 11-081
, the core thickness D1 is 0, 0-1 to 0, 07 I) (where D is the drill diameter). Then, the line connecting the outer edges of the back side of both blades and the center f of the back side of the blade! I11 f made with the tangent to the curved surface
r1α is 10° to 15°, the radius of curvature R1 of the curved surface on the center side of the back of the blade is 0.1 to 0.2D, and the diameter D3 of the curved surface from the back of the blade to the heel is φ01 to 02D1 Heel 4
The radius of curvature R2 of the curved surface on the center side is 05 to 08I), and the distance from the drill center, that is, the diameter D2 of the boundary between the outer end 5b and the fourth part 5a of the heel surface 5 is φ085D. In addition, in conventional high-rigidity trills for steel, the groove width ratio is 08 to 0.
9 I, Shin Atsushi 02 to 0.45 I), and I had to do the nnning without fail. In addition, the groove width ratio of the marked drill for iron plate is 131 to 1・1, and the core thickness is 0.1 to 0.
20D, and thinning was sometimes necessary.

According to the above embodiment, the outer end 5b of the heel surface 5 is thickened, and the protrusion 4c is formed on the back surface 4 of the blade to increase the thickness, thereby increasing the drill rigidity without increasing the core thickness. can be improved. In addition, since the heel part 5 is provided with the recessed part 5a, the core is smaller than the thick-core drill 3 or the high-rigidity drill 2, and when the blade is sharpened, it becomes smaller than the drill, resulting in lower cutting resistance and improved cutting performance. This improves the performance and eliminates the need for thinning. Therefore,
This will definitely solve the problem of the conventional high-rigidity drill 2, where poor thinning or hole drilling affects accuracy. Further, it is not necessary to perform thinning every time re-grinding is performed. Furthermore, in response to the decrease in core thickness as described above, the cross-sectional area of the depth discharge lf46 is increased in the case of the narrow drill 3 and the high-rigidity drill 2.
It is larger and has better chip ejection performance. Also,
By providing a U-shaped recess il < 5 a on the center side of the heel portion 5, the depth discharge groove 6 can be shifted much more than the depth discharge 7i'i of the conventional high-rigidity trill 2 or the standard drill 3. Since the chips can be smoothly guided into the chip ejection groove 6 along the curved surface of the outer side 4a of the protrusion 4c on the back surface 4 of the blade, the ejection performance of the chips is improved.

Note that the present invention is not limited to the above embodiments,
It can be implemented by various other @-sama. For example, the L center thickness part has a very slight taper (0 to 0.5/1
00). In addition, a larger taber (1 to 2/1 oo) may be placed on the thick core part, as shown in Figure 6. Also, as shown in Figure 7.8, the drill has a front part 8 extending from the tip to the center in the axial direction of the drill.
If the rear part 9 from the center to the rear end has a cross-sectional shape as shown in FIG. 8, the front part 8 has a cross-sectional shape as shown in FIG. , rear 9
Parallel core thickness parallel to the drill axis direction (0/1
00) is better. Also, as shown in FIG. 9, the thick core portion of the front portion 6 has a center Y? in the trill axis direction. Qi Ku (0~
Alternatively, the core thickness of the rear portion 9 may be made parallel to the core thickness (0/+00). Also,
As shown in Figure 10? The core thickness portion of the front portion 8 may have a parallel core thickness (0/100), while the core thickness portion of the rear portion 9 may be slightly tapered (0 to 0.5/100). Furthermore, as shown in FIG. 00)
It's good to add . In addition, as shown in Fig. 12, only the tip IO can be pressed with a grindstone as a cutter to process the U groove, or as shown in Fig. 13, only the tip IO can be pressed and processed. The remaining portion may have a parallel core thickness or a uniform taber as shown by the two-dot chain line in the figure. In addition, among the above-mentioned modifications, No. 9.
10.11. A cross-sectional view taken along the line AA in Figure 3 is shown in FIG. 6, and a cross-sectional view taken along the line 13-13 is shown in FIG.

Further, as shown in FIG. 14, the drill may be configured such that the heel portion 7 is shaved off to enlarge the space of the chip discharge groove 6 to improve penetration of the cutting oil. In this case, the life of the trill did not decrease due to the reduction in the rigidity of the drill due to the heel portion 7 being shaved off.

In addition, the 114 width ratio and thick core of drill 1 are for light alloy,
Unlike the drills for aluminum and the above-mentioned steel drills, the ifη width ratio, core thickness, etc. are determined depending on the use, so that thinning is not necessary.

An example of a trill for light alloys and aluminum is if
& Increasing the width ratio from 15.1 to I 6 l,
The twist angle is 38~. 12. Strange and thick 14-ru 1,
C.17 is the same as the steel trill.

In addition, as shown by diagonal lines in Fig. 3, if the thick core part of the drill 1゛ is further non-nicked, the chiseling depth will become smaller, the cutting resistance will become smaller, and the hole drilling will be less accurate. .

Effects of the Invention According to the above structure, in the axial cross section of the drill, the outer end of the heel surface of the blade protrudes into the depth discharge Fl'Y, while the back surface of the blade protrudes in a substantially triangular shape toward the chip discharge groove. It is possible to increase the l-rill rigidity without increasing the core thickness, and the so-called efficiency can be achieved. By making a roughly U-shaped recess on the center side of the blade, the core thickness becomes smaller, the chisel becomes smaller, and the cutting resistance becomes smaller. Brightness does not affect accuracy. Further, there is no need to perform non-herring every time the drill is re-ground.

Furthermore, since the back surface of the knife protrudes in a substantially diagonal shape, the cutting sawtooth Pi, that is, the chip, is smoothly guided into the chip ejection groove along the slope on the side of the approximately 3μ-shaped protrusion. At the bottom, there is a U-shaped recess on the center side of the heel surface,
Corresponding to the smaller core diameter, the cross-sectional area of the chip ejection groove becomes larger than that of a marker drill or a high-rigidity drill, and the depth ejection performance improves.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the cutting edge of a drill according to an embodiment of the present invention, FIG. 2 is a more specific front view of the tip of the drill, and FIGS. A front view and a cross-sectional side view of the drill bit shown in Fig. 5, 1.6, 7, 9. +
0.11.13 A-A cross-sectional view, No. 6.7, 9,
Figures 10, 11 and 13 are cross-sectional side views of filter trills according to other embodiments, respectively, and Figure 8 is a cross-sectional side view of the filter trill of other embodiments. IO, l 13 in Figure 1
- r3 line sectional view, FIG. 12 is a side view of a drill according to another embodiment, FIG. 14 is a sectional view of a drill according to another embodiment, and FIGS. 15, 16, and 17 are conventional high rigidity drills, respectively. FIG. 1 is an explanatory diagram of a case where sonning is performed on a drill. 1.1° Drill according to the embodiment, 2. Conventional drill, 2
b Back side of blade, 2c/heel side, 3 Bevel drill, 3a
Back of the blade, 3b, heel surface, 11, back of the blade, 4a...outside, = 1 b, center side, 4c protrusion, 5...heel surface,
5a-U-shaped recess, 5b...outside ((11" 1b part,
6. Depth discharge groove, 7. Heel part. Patent Applicant Kobe Steel Co., Ltd. Agent Patent Attorney Aoyama Ao et al. 28 cases Figure 7

Claims (1)

[Claims] (1) The heel surface (3b
), the outer end (5b) of the heel surface (5) protrudes into the chip ejection groove (6), and the center side of the heel surface (5) is approximately U-shaped from the heel surface (3b) of the standard cross-sectional blade shape. At least the tip has a cross-sectional shape in which the blade back surface (4) protrudes in a substantially triangular shape from the blade back surface (3a) of the standard cross-sectional blade shape toward the chip ejection groove (6). A drill characterized by: