JPH0420565Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a boring drill used for drilling holes in wood-based or resin-based materials and similar composite materials.

Prior Art Boring drills for woodworking that have been widely used in the past include single-blade or double-blade types.
Furthermore, some have hairbiki blades while others do not. In general, the machining quality at the entrance of the machined hole is higher with two blades than with one blade, and with a hairbrush blade rather than one without. For this reason, as shown in Figures 19 to 21, a two-blade type boring drill is equipped with a pointed kebiki blade with an acute blade angle, and has a guide aperture higher than the kebiki blade at the tip of the center of rotation. is often used.

Problems that the invention aims to solve: Conventional boring drills have a guide aperture at the center of rotation and no cutting edge at the center of the bottom edge, so cutting resistance in the feed direction during drilling is high, and On the other hand, the hair cutting blade has a short lifespan. In addition, the guide awl and pointed hair blade were often damaged by being hit, rendering them unusable.

Means for solving the problem Two or three chip discharge grooves 2 are formed at equal positions on a cylindrical body 1, and the remaining parts are the same number of blade bodies 3, and the rotation side of each blade body 3 is In the woodworking boring drill in which the tip of the chip discharge groove 2 surface is the rake surface of the bottom blade 4, grooves 5 and 6 are formed in a substantially V-shape at the tip of each blade 3, and the V-shape A line of intersection between one side of the grooves 5, 6 and the outer circumferential surface of the blade body 3 forms a round hair pulling blade 7, 8 consisting of a substantially circular arc curve, and the other side of the V-shaped grooves 5, 6 and the rake The bottom blade 4 is formed from the outer periphery to the center or near the center according to the line of intersection with the surface. Note that the V-shaped groove herein also includes a groove in which both side surfaces are inclined, such as an inverted trapezoidal groove.

Embodiment 1 An embodiment of the present invention will be described below based on the drawings. In Figures 1 to 5, a cylindrical body 1
A cross section perpendicular to the axis of
A chip discharge groove 2 with a rectangular cross-sectional shape and long in the axial direction is located slightly across the second quadrant, leaving a part of the quadrant.
is cut to the center, and the remaining parts form each blade body 3 connected at the center, and the tip of the chip discharge groove 2 surface on the rotating side of each blade body 3 becomes a rake face. The tip of each blade 3 has an intersection angle γ that intersects on the outer circumferential side with the cutting edge line formed by the tip of the rake face when viewed in the axial direction, and has a surface perpendicular to the axis in a direction that becomes deeper as the rotation progresses. On the other hand, V-shaped grooves 5, 6 having an inclination angle β are provided. The intersection line between one side of these V-shaped grooves 5 and 6 and the rake face is formed on the bottom blade 4, which is a cutting edge line perpendicular to the axis of the body 1, and a relief surface is provided. , 6 is the blade body 3
The lines of intersection with the outer peripheral surface form round hair pulling blades 7 and 8. As shown in the axial cross-sectional view (Fig. 5) of the blade body including the center line viewed from the intersection angle γ direction of the V-shaped grooves 5 and 6, the tip angle α of the round hair-brushing blades 7 and 8 is V. It is formed by the letter-shaped grooves 5 and 6, and the round hair pulling blade 7,
The cutting edge line 8 has a substantially elliptical arc shape created when a cylinder is cut diagonally, and the height of the top of the cutting edge line is slightly higher than the bottom blade 4. The respective angles formed by the V-shaped grooves 5 and 6 are, for example, the tip angle α of 30° to 70°, the inclination angle β 0° to 50°, and the intersection angle γ 0° to 75°. The heights of the bottom blade 4 and the round hair pulling blades 7, 8 can be set depending on these angles and the shapes of the V-shaped grooves 5, 6. Furthermore, a scraping surface 9 is provided on the groove surface at the tip of the chip discharge groove 2 in the first and third quadrants, and the bottom blade 4 is formed with the cutting edge extending to the center.

Embodiment 2 In FIGS. 6 and 7, the same parts as in Embodiment 1 are denoted by the same reference numerals, and the explanation thereof will be omitted. R to body 1
A chip discharge groove 12 having a shaped cross section is formed in a twisted manner, and the remaining parts form each blade body 13 connected at the center, and a groove 14 is carved on the outer periphery of the tip of the blade body 13. The connecting tip 15 is firmly bonded by brazing or adhesive. The diamond sintered chip 15 has a diamond layer 15a on its outer peripheral surface, and the cutting edges of the round hair pulling blades 7 and 8 are formed by the diamond layer 15a. The round hair cutting blades 7 and 8 have a large width in the direction of rotation and have an elliptical arc-shaped cutting edge line without a sharp edge that is prone to chipping, so it is possible to use diamond sintered chips with low toughness without chipping, which is extremely effective. The service life of the round hair cutting blades 7 and 8 can be extended, and the twisted chip discharge groove 12 facilitates chip discharge.

Embodiment 3 In FIGS. 8 and 9, the difference from Embodiment 2 is the diamond layer 17 of the diamond sintered chip 17.
A is provided on the inclined surface of the V-shaped grooves 5 and 6 forming the hair cutting edge angle α. This has the same advantages as the second embodiment.

Embodiment 4 In FIGS. 10 to 12, the tip of the blade 13 similar to that in Embodiment 2 is fixed to a carbide tip 18 by brazing or butt-jointing with adhesive.
The difference is that it is formed by
This material can significantly extend the life of the cutting edge compared to high speed steel or carbon steel.

Embodiment 5 The difference in FIGS. 13 and 14 from Embodiment 1 is that the center of the bottom blade 20 is formed slightly higher than the top of the round hair-pulling blades 7 and 8. The height relationship between the bottom blade 20 and the round hair cutting blades 7, 8 can be obtained by setting the shape of the V-shaped grooves 5, 6 and the hair cutting blade tip angle α, inclination angle β, and intersection angle γ, For example, when drilling a hole in a hard material decorative board made of phenolic resin, etc., the round material of the hard material decorative layer is rounded by cutting the outer periphery of the hole with round hair cutting blades 7 and 8. This can prevent the boring bit from remaining in the hair cutting blades 7, 8 and spinning idly, making it impossible for the boring drill to dig into the hole.

Example 6 In the two types of boring drills shown in FIGS. 15, 16, 17, and 18, Example 1
The different part is that the amount of scraping off of the scraping surfaces 21, 23 is large and the tips are deeply scraped off beyond the center of rotation, and the cutouts 22, 24 are at the center of rotation.
is formed. When the bottom blades 4, 4 bite into the workpiece, the incision 22,
The convex portion at the center of the machined hole created by 24 provides self-aligning properties and prevents run-out of the cutting edge.

Function: Insert and fix body 1 of the boring drill of this example into the main shaft chuck of a woodworking drilling machine, fix the workpiece to the table, make the drilling position of the workpiece concentric with the main shaft, and rotate the main shaft. The machine is lowered onto the workpiece and the slightly protruding round hair cutting blades 7 and 8 are used to cut the outer periphery of the machined hole. The cutting edge lines of the round hair cutting blades 7 and 8 have an elliptical arc shape, and they cut the workpiece while always pressing it in the feeding direction, and the true cutting angle of the round hair cutting blades 7 and 8 when viewed from the rotation direction is extremely small. The inner peripheral surface of the entrance of the machined hole is cut to an extremely high quality. Then, as the round-haired blades 7 and 8 dig in, the bottom blades 4 and 4
scrapes the inside of the hole. The bottom blades 4, 4 have cutting edges up to the center of rotation, and the cutting edges extend all the way to the outer periphery without being obstructed by the round hair pulling blades 7, 8, so cutting resistance in the feed direction is low and the entire bottom of the hole can be easily cut. The scraped chips are discharged out of the hole through the chip discharge grooves 2 and 12 having a sufficiently large chip storage capacity.

Effects As detailed above, the present invention has a round hair pulling blade with an elliptical arc-shaped cutting edge line, a bottom blade with a cutting edge that can cut almost the entire bottom of the hole, and a large chip discharge groove obtained by the mutual positional relationship between these blades. This structure makes it easy to form the round hair cutting edge, bottom blade, and chip discharge groove, and reduces the cutting resistance in the feed direction during cutting, improving the machining quality at the hole entrance and the durability of the round hair cutting blade. This has the effect of dramatically improving the properties and providing a clean hole bottom surface with extremely small undulations. Furthermore, since the conventional thin protruding guide awl and pointed kebiki blade have been eliminated, the guide awl and pointed kebiki blade do not break due to impact and become unusable, and the awl can extend its lifespan. It has a beneficial effect.

[Brief explanation of the drawing]

Figure 1 is a side view of the first embodiment of the boring drill of the present invention, Figure 2 is its end view, Figure 3 is a side view of the tip viewed from the direction of the V-shaped groove, and Figure 4 is the V-shaped groove. FIG. 5 is a side cutaway view of the tip viewed from the direction of the V-shaped groove, FIG. 6 is a side view of the second embodiment, FIG. 7 is its end view, and FIG. 9 is a side view of the tip of the third embodiment, FIG. 9 is an end view thereof, FIG. 10 is a side view of the fourth embodiment, FIG. 11 is an end view thereof, and FIG. 12 is the direction of the V-shaped groove. FIG. 13 is a side view of the tip of the fifth embodiment, FIG. 14 is an end view thereof, FIGS. 15 and 17 are side views of the sixth embodiment, and FIG. 16 is a side view of the tip of the fifth embodiment. 15th
18 is an end view of FIG. 17,
Figure 19 is a side view of a conventional boring drill; Figure 20 is a side view of a conventional boring drill;
The figure is an end view, and Figure 21 is relative to Figure 19.
FIG. 3 is a side view of the tip shifted by 90°. 1...Body, 2...Chip discharge groove, 3...Blade body, 4...Bottom blade, 5, 6...V-shaped groove, 7, 8
... Marukebikiblade.

Claims (1)

[Claims for Utility Model Registration] (1) Two or three chip discharge grooves are formed at equal positions on a cylindrical body, the remaining parts are the same number of blades, and the rotating side of each blade is In a woodworking boring drill in which the tip of the chip discharge groove surface is the rake surface of the bottom blade, a substantially V-shaped groove is formed at the tip of each of the blades, and one side of the groove and the outer periphery of the blade are formed. Forming a round hair cutting blade whose intersection line with the surface is a substantially circular arc curve, and forming a bottom blade from the outer periphery to the center or near the center by the intersection line of the other surface of the V-shaped groove and the rake surface, A boring drill for woodworking characterized by not having a guide drill in the center. (2) A boring drill for woodworking according to claim 1, which uses a diamond sintered tip in a round hair cutting blade.