JPH0634894Y2 - Rotary cutting tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rotary cutting tool such as an end mill used in a milling machine or the like, and more particularly to improvement of a rotary cutting tool capable of supplying compressed air.

[Conventional technology]

When performing milling cutting with a rotary cutting tool such as an end mill having a straight shank, the generated chips are caught and the cutting edge is chipped or chipped, making it unusable. Scratching the surface is a common experience.

Therefore, in order to eliminate the above-mentioned trouble caused by chips, a method has been adopted in which compressed air or the like is jetted from the outside of a rotating tool by a nozzle to a cutting blade portion. However, in this method, since the nozzle position with respect to the cutting blade is fixed, the nozzle position is not optimal and stable chip removal cannot be performed in the machining such as contouring by a machining center where the cutting direction changes.

For this reason, it has been proposed, for example, as in Japanese Patent Publication No. 61-44608, to inject a pressurized fluid from the inside of the end mill body in a direction substantially orthogonal to the cutting blade. In this case, the generated chips can be reliably removed from the cutting edge regardless of the change in the cutting direction.

[Problems to be solved by the invention]

However, this conventional type has no problem if it is only one-step planing, etc., but when further grooving the surface where chips generated in the previous step are scattered, or where there are holes or counterbores or uneven shapes In case of cutting and drilling in several times, chips scattered in the cutting surface due to this previous step or chips accumulated in holes or spot facings or uneven corners or recesses of the work material As a result, chips may be caught, resulting in deterioration of the finished surface and chipping of the cutting edge. An object of the present invention is to solve the above problems and to provide a rotary cutting tool with less trouble due to chips.

[Means for solving problems]

In order to achieve the above object, the present invention has the following constitutional requirements. That is, the rotary cutting tool of the present invention has a tool body having a cutting blade on the outer peripheral side of the shank portion and the other end, a supply hole extending for ejecting compressed air into the tool body, and a communication hole communicating with the supply hole. In the rotary cutting tool having an injection hole to be formed, the injection hole is composed of two types of a first injection hole and a second injection hole, and the first injection hole is provided on the outer periphery of the cutting blade adjacent to the cutting blade. It is provided at a position slightly closer to the shank than the blade height, and is opened so as to eject toward the surface to be cut outside the rotation trajectory, and the second injection hole is opened to the chip discharge groove that is connected to the cutting blade. It is characterized by

[Action]

According to the present invention, of the two types of injection holes through which compressed air is ejected during cutting, the first ejection hole opens at a position slightly closer to the shank of the holder flank, and is ejected toward the outer side to generate chips. Even when grooving the remaining surface, the chips remaining on the cutting surface are removed to the outside within a range of 360 ° around the tool body. That is, the cutting surface to be cut in the cutting direction is always cleaned while cutting.

Further, since the compressed air is ejected from the second injection hole toward the cutting blade, the chips generated by the cutting blade can be reliably separated and scattered from the cutting blade. That is, the chip trouble of chip entrapment during cutting can be almost completely prevented by the synergistic effect of the first and second injection holes and the both injection holes.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 (a) is a front view of a two-blade throw-away type end mill according to the present invention, and FIG. 1 (b) is a side view thereof. In both figures, the tool body 1 comprises a straight shank portion 2 and a tip portion 3. 2 at the tip of tip 3
One chip discharge groove 9 is formed, and a throw-away tip 6 having a cutting edge 61 on the outer periphery is detachably fixed to a tip seat in the groove by a set screw 7.

Two types of injection holes 5a, 5b are provided on the tip end 3 side so as to communicate with the supply hole 4 extending near the longitudinal axis of the tool body 1. That is, the first injection hole 5a
Is provided at a position slightly closer to the shank than the cutting edge height on the outer periphery of the adjacent cutting edges, and is opened so as to eject toward the surface to be cut outside the rotation locus.
That is, the cutting edge is provided on the outer periphery of the cutting edge adjacent to the outer peripheral tip 6 in the vicinity of a distance 1 from the tip of the cutting edge.
An opening is formed so as to eject toward the surface to be cut outside the rotation locus of the cutting edge rear end 62 of 61. Further, the second injection hole 5b is formed in the chip discharge groove 9 so that the compressed air is ejected toward the cutting blade 61.

With the above configuration, the compressed air supplied from the outside through the adapter (not shown) during cutting passes through the supply hole 4 and is ejected from each of the two injection holes 5a and 5b. Therefore, for example, even if chips are scattered on the upper surface of the work piece to be groove-cut, the chips are always forcibly scattered to the outside of the cutting edge 61 by the compressed air ejected from the first injection hole 5a during cutting. To be done. In other words, the cutting is performed while constantly cleaning the upper surface of the work material to be cut in the cutting direction. or,
The chips generated by the cutting blade 61 during cutting are reliably separated and scattered in the groove direction after the cutting, which is the opposite of the cutting direction, by the compressed air ejected from the second injection holes 5b toward the cutting blade.

Therefore, by providing the first injection hole 5a and the second injection hole 5b together, it is possible to almost completely prevent the trouble due to the chips as described above for the first time. This has the great advantage that the original performance of the tool can be fully exhibited and unmanned operation by the machining center becomes more reliable.

Further, as an embodiment of the present invention, the opening direction of the second injection hole 5b opening in the chip discharge groove 9 is directed toward the cutting blade rear end 62 side with respect to the direction orthogonal to the tool body axis as shown in FIG. It may be provided at an angle, that is, at an angle θ. This is because the chips generated by the second injection holes 5b in the embodiment of FIG. 1 are sprayed on the cutting surface and scattered along the cutting surface, whereas in the embodiment of FIG. Since it is a shape that is blown to, it is possible to fly chips further away from the tool body without damaging the cutting surface with chips, which is effective in the case of mid-finish cutting. The angle θ may be appropriately selected in consideration of the cutting edge shape of the rotary cutting tool, the cutting edge length, etc., but in the case of a right-angle cutting end mill as shown in FIG. 2, it is approximately 5 ° to 30 °. Is the range.

Further, as the corner angle of the throw-away type end mill becomes larger, the chip discharge performance becomes better. Therefore, the angle θ can be made smaller in the throw-away type end mill having a larger corner angle, but it is desirable to secure 3 ° or more. .

Although the two-blade throw-away type end mill has been described above, the present invention is not limited to this and can be applied to various rotary cutting tools.

The supply hole 4 extending into the tool body may be provided from the end surface of the straight shank portion as in the embodiment, or compressed air can be supplied from the straight shank portion 2 in the radial direction as shown in FIG. It can also be formed. It is also within the scope of the present invention to form the injection hole 5a so as to open in the chip discharge groove 9 which is a part of the tip portion 3.

Also, the number and size of the injection holes 5a, 5b can be appropriately selected according to the shape of the rotary cutting tool and the work material.

[Effect of device]

Therefore, according to the present invention, it is possible to provide a rotary cutting tool capable of almost completely preventing troubles due to chips due to the first injection hole, the second injection hole, and the synergistic effect of these.

[Brief description of drawings]

FIG. 1 (a) is a front view of a throw-away type end mill according to an embodiment of the present invention, FIG. 1 (b) is a side view thereof, and FIG. 2 is another embodiment of the second injection hole in FIG. FIG. 3 is a schematic front view showing another embodiment of the supply hole. 1 ... Tool body 2 ... Straight shank part 3 ... Tip part 4 ... Supply hole 5a ... First injection hole 5b ... Second injection hole 9 ... Chip discharge groove 61 ... Cutting edge 62 ... Cutting Rear edge of blade

Claims (1)

[Scope of utility model registration request] 1. A tool body having a cutting edge and a cutting edge on the outer peripheral side of the other end, a supply hole extending for ejecting compressed air into the tool body, and an injection hole communicating with the supply hole. In the rotary cutting tool having, the injection hole is composed of two types of first injection hole and second injection hole, and the first injection hole is
The cutting blade is provided at a position slightly closer to the shank than the cutting blade height on the outer periphery of the adjacent cutting blades, and is opened so as to jet toward the surface to be cut on the outer side of the rotation trajectory. A rotary cutting tool having an opening in a chip discharge groove connected to a cutting blade.