JP2678016B2 - Reamer with tip blade - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reamer for cutting and reaming an inner peripheral portion of a prepared hole, and more particularly to a technique for significantly improving chip discharging property. Is.

[Prior Art] Conventionally, as this type of reamer with a tip blade, those shown in FIGS. 5 and 6 are known. In this reamer with a tip blade, a plurality of twist grooves 2 with a twist angle of 40 ° to 60 ° to the left are formed on the outer peripheral portion of a tool body 1 rotated about an axis, and A cutting edge (hereinafter referred to as a reamer blade) 3 whose outer diameter gradually decreases from the base end side toward the tip end side is formed at the tip end portion of the outer peripheral margin 2a continuous with the twist groove 2, and the tip wall of the tool body 1 is formed. To the department
A chip pocket 4 is formed by notching the wall portion from the inner peripheral side toward the outer peripheral side, and the outer peripheral side ridge line portion of the wall surface facing the rotation direction of the chip pocket 4 traverses the tool main body 1 toward the outer peripheral side. A tip cutting edge 5 that is inclined toward the base end side with respect to the surface is formed.

This reamer with a tip blade is for cutting the inner peripheral portion of a pre-drilled hole with a tip cutting blade 5 while leaving a reaming finishing allowance, and for finishing the hole with a reamer blade 3. The chips generated by 5 are discharged through the chip pocket 4, and the chips generated by the reamer blade 3 are also discharged through the spiral groove 2 in the chip pocket 4, and the cutting oil is further discharged through the spiral groove 2. It is designed to be supplied to the cutting section.

[Problems to be Solved by the Invention] In the reamer with a tip blade, chips generated by the tip cutting blade 5 and the reamer blade 3 are both discharged through the chip pocket 4, so that each chip is removed. Interference with each other easily causes chip clogging. Moreover, since the twist angle of the twist groove 2 is as large as 40 ° to 60 °, it is difficult for the chips to flow, so that there is a problem in the chip discharging property. Further, since the helix angle of the spiral groove 2 is large, the effective length in the axial direction with respect to the actual length of the reamer blade 3 is short. Therefore, the length of the reamer blade 3 must be set to be long. There is also a problem that polishing is difficult.

[Object of the Invention] The present invention has been made in order to solve the above problems, and of course, the chip discharging property can be greatly improved, and the reamer blade can be shortened. An object of the present invention is to provide a reamer with a tip blade that can easily re-polish a reamer blade.

[Means for Solving the Problems] In the reamer with a tip blade of the present invention, the twist angle of the twist groove is set to 5 ° to 40 °, and the bottom surface of the tip pocket of the tip cutting blade portion is directed toward the outer peripheral side. Accordingly, it is formed so as to be inclined toward the tip side with respect to the tip cutting edge. However, it is preferable that the chip pocket is formed so that its cross-sectional area gradually increases from the outer peripheral side toward the inner peripheral side.

[Operation] The chips generated by the tip cutting edge extend in a direction orthogonal to the tip cutting edge and are bent by the bottom surface of the chip pocket. Here, in the above reamer with a tip blade, since the bottom surface of the chip pocket is formed so as to be inclined toward the tip side with respect to the tip cutting edge toward the outer peripheral side, the chips are spiraled toward the inner peripheral side. Can be bent into a shape. Therefore, the chips extend toward the inner peripheral side and fall into the prepared hole of the work material. Therefore, the chips produced by the tip cutting blade and the chips produced by the reamer blade do not interfere with each other. In this case, if the chip pocket is formed so that the cross-sectional area on the inner peripheral side is larger than that on the outer peripheral side, the chips can flow more easily.

In addition, since the helix angle of the helix groove is set to 5 to 40 degrees, chips can pass easily, and the effective length in the axial direction relative to the actual length of the reamer blade is long, so the length is shortened. be able to.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 2 is a side view showing the reamer with a tip blade of the embodiment. In the figure, reference numeral 10 denotes a tool main body. The tool main body 10 has a columnar appearance that is rotated around an axis, and four twist grooves (grooves) 11 ... Which extend to the tip end surface of the tool main body 10 are formed on the outer periphery thereof. The twist angle α of the twist groove 11 is set to 5 ° to 40 ° to the left and to the left. In addition, a relief groove 12 is formed on the outer periphery of the tool body 10 near the tip, over the entire periphery thereof.
And, in the ridge line portion of the predetermined range extending from the escape groove 12 toward the base end side of the outer peripheral margin 11a continuous to each twisted groove 11, the outer diameter gradually decreases from the base end side to the tip end side, the reamer blade 13 Are formed.

Further, the tool main body 10 has four tip pockets formed on the tip wall portion by notching the wall portion from the inner peripheral side toward the outer peripheral side.
14 are formed at equal intervals in the circumferential direction such that the wall portion on the rotation direction side intersects with the twist groove 11. The chip pockets 14 do not necessarily have to be formed at equal intervals. A cutting edge (tip cutting edge) 15 inclined toward the outer peripheral side toward the outer peripheral side toward the base end side with respect to the cross section of the tool body 10 is formed on the outer peripheral side ridge portion of the wall surface facing the rotation direction of each chip pocket 14. . The tip pocket 14 is composed of a flat rake face 16 including a cutting edge 15 and a concave curved surface (bottom surface) 17 having a substantially arcuate cross section, and the concave curved surface 17 with respect to the cutting edge 15 toward the outer peripheral side. It is formed on the tip end side with an angle of inclination indicated by β in FIG. The chip pocket 14 is formed so that its cross-sectional area gradually increases from the outer peripheral side toward the inner peripheral side. Furthermore, the outer peripheral surface between the twist grooves 11 and the wall surface on the tip side of the escape groove 12 is formed into a cylindrical curved surface 18 provided with a so-called back taper of about 3/100.

When cutting is performed by such a reamer with a tip blade, the chips 20 generated by the cutting edge 15 extend in a direction orthogonal to the cutting edge 15 and are bent by the concave curved surface 17 of the chip pocket 14. Here, in the above-mentioned reamer with a tip blade, since the concave curved surface 17 of the chip pocket 14 is formed to be inclined toward the outer peripheral side with respect to the cutting blade 15 toward the tip side, as shown in FIG. Is bent in a spiral shape toward the inner peripheral side. Therefore, the chips 20 curl in the direction of the arrow X in the drawing and fall into the prepared hole of the work material. Furthermore, since the cross-sectional area of the chip pocket 14 is larger on the inner peripheral side than on the outer peripheral side, the chips are more likely to pass through, and the dischargeability thereof is further improved.

The hole whose diameter has been expanded in this way is slightly finished with a cutting margin by the reamer blade 13. In this case, only the chips generated by the reamer blade 13 flow through the twist groove 11, and the twist angle is set to a small value of 5 ° to 40 ° to the left side, so that the chips can pass easily and smoothly to the tip side. Is discharged. Further, cutting oil for cooling and lubricating the cutting portion is supplied into the twisted groove 11, and this cutting oil flows into the chip pocket 14 to lubricate and cool the cutting portion.

Thus, in the reamer with a tip blade, since the chips generated by the cutting blade 15 are forcibly discharged to the hole of the work material, the chips are generated by causing interference with the chips generated by the reamer blade 13. It does not cause clogging and also has a twist groove.
Since the twist angle α of 11 is small, the chips can be smoothly circulated, and therefore the chip discharging property can be greatly improved. Further, since the twist angle α of the twist groove 11 is small, the effective length of the reamer blade 13 in the axial direction is long, and the length of the reamer blade 13 can be set short. Therefore,
Re-polishing of the reamer blade 13 can be easily performed.

Further, since chips easily flow in the spiral groove 11, cutting oil can be supplied smoothly, the cross-sectional area of the spiral groove 11 can be reduced, and the tool rigidity can be improved.

[Effects of the Invention] As described above, in the reamer with a tip blade of the present invention,
The twist angle of the twist groove is set to 5 ° to 40 °, and the bottom surface of the chip pocket is formed so as to be inclined toward the tip side with respect to the tip cutting edge toward the outer peripheral side. It is possible to prevent interference between the cutting blades and prevent clogging of chips. Moreover, since the twist angle of the twist groove is small, the chips flow smoothly through the twist groove, and therefore the chip discharging property can be greatly improved.

Further, since the twist angle of the spiral groove is small, the effective length of the reamer blade in the axial direction is long, and therefore the length of the reamer blade can be set short and the re-sharpening of the reamer blade can be facilitated. . Furthermore, the effect that the cross-sectional area of the twist groove can be reduced to improve the tool rigidity can be obtained.

[Brief description of the drawings]

1 to 4 are views showing an embodiment of the present invention, wherein FIG. 1 is a sectional view taken along the line II in FIG. 3 showing the tip of a reamer with a tip blade, and FIG. 2 is the tip. FIG. 3 is a side view of the reamer with a blade, FIG. 3 is a front view in the axial direction thereof, FIG. 4 is a perspective view showing a state in which chips are bent, and FIGS. 5 and 6 show a conventional reamer with a blade. , Fig. 5 is its side view,
FIG. 6 is a view in the axial direction showing the tip of the reamer with a tip blade. 1 ... Tool body, 2 ... Helical groove, 3 ... Reaming blade, 4 ... Tip pocket, 5 ... Cutting edge, 10 ... Tool body, 11 ... Helical groove, 13 ... Reaming blade (cutting edge) ), 14 …… Chip pocket, 15 …… Cutting edge (tip cutting edge), 17 …… Concave curved surface (bottom surface).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 61-195920 (JP, U) Rikai Sho 55-70922 (JP, U) Rikai 61-109628 (JP, U) Japanese Patent Sho 40- 26674 (JP, B1) Actual public Sho 48-27899 (JP, Y1)

Claims (1)

(57) [Claims] 1. A twist groove is formed in an outer peripheral portion of a tool body rotated about an axis, and a tip ridge line portion of an outer peripheral margin continuous with the twist groove is formed from a base end side toward a tip end side. A cutting edge with a gradually decreasing outer diameter is formed, and a tip pocket is formed on the tip wall portion of the tool body by notching the wall portion from the inner peripheral side toward the outer peripheral side, and the rotation of this chip pocket In a reamer with a tip blade in which a tip cutting edge inclined toward the outer peripheral side toward the base end side is formed on the outer peripheral side ridge line portion of the wall surface facing in the direction, It is set at 5 ° to 40 °, and the bottom surface of the tip pocket is formed so as to be inclined toward the tip side with respect to the tip cutting edge toward the outer peripheral side. Reamer.