JP2006212725A - Drill for high efficiency machining of aluminum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of increasing cutting resistance to impede stable machining of a workpiece caused by deposition to a thinning cut face or the like when thinning a drill center part to improve centripetal property and to reduce cutting resistance in a drill for high efficiency machining of aluminum for boring aluminum or the like. <P>SOLUTION: The drill for high efficiency machining of aluminum has a cutting edge at a drill groove tip part and is thinned at the center part viewed from the cutting edge side axial end. An intersection formed by the thinning cut face 4 and a thinning heel face 5 is formed in round shape, and the curvature of the intersection R is set to ≥5% and ≤50% of a drill web thickness. The connection parts of a round part and the thinning heel face are spaced over the drill center, and the position of the intersection R is located within a range of +2 mm to -3 mm from the drill center axis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The invention of the present application is used for drilling of aluminum, etc., and has a thinning shape that improves cutting efficiency near the center by improving the thinning shape of the center of the drill, reduces cutting resistance, improves welding resistance, and enables high-efficiency machining. The present invention relates to a drill for machining aluminum with high efficiency.

When drilling aluminum, etc., with a general aluminum high-efficiency drill for aluminum, early welding occurs on the thinning surface at the center of the cutting edge, resulting in poor chip evacuation and cutting resistance. This leads to an increase, and eventually breaks the drill. In Patent Document 1, X-type thinning is applied to the center portion of a drill cutting edge in order to reduce thrust during cutting and to improve centripetality and chip disposal. However, in the conventional X-type thinning, the curvature of the valley bottom composed of the thinning scooping surface and the thinning heel surface is as small as almost 0, and the thinning valley bottom is V-shaped, so the chips cut by the thinning cutting edge accumulate on the thinning valley bottom, Since it does not flow smoothly, it induces welding on the thinning cutting edge and affects the main cutting edge. As a result, the thrust resistance is increased and the centripetality is lowered, so that stable cutting cannot be performed.
JP-A-2-124207

  The present invention is an aluminum high-efficiency machining drill for drilling aluminum, etc., and the work that occurs when thinning the center of the drill to improve centripetality and reduce cutting resistance is applied to the thinning scoop surface, etc. Welding solves problems such as increased cutting resistance and inability to perform stable machining.

  The invention of the present application is an aluminum high-efficiency machining drill having a cutting edge at the tip of the drill groove and thinned at the center when viewed from the cutting edge side axial end, and is composed of the thinning scoop surface and the thinning heel surface. The intersection point R has a radius of curvature of 5% to 50% of the drill core thickness, the connecting portion of the R-shaped portion and the thinning heel surface is spaced beyond the center of the drill, and the intersection R position is away from the drill center axis. It is an aluminum high-efficiency machining drill characterized by being located in a range of +2 mm to -3 mm, more preferably, the maximum separation distance of the R-shaped portion is 5% to 70% of the drill core thickness, The crossing width of the thinning cutting edge is reduced from 0.1% to 50% of the drill diameter toward the center of the drill. The thickness of the thinning scooping surface, thinning bottom R curvature surface, thinning heel surface and chip discharge groove surface The roughness is Rz 0.2 or more and 1.5 or less, and a spiral through hole for fluid supply for supplying cutting fluid, cutting mist, air, or the like is provided, and the core thickness of the drill is the thickness from the cutting edge side toward the shank side. Is provided with one or more of a first core thickness portion, a second core thickness portion, and a third core thickness portion that are substantially constant, wherein the core thickness of the first core thickness portion is greater than the core thickness of the second core thickness portion. The third core thick part is made thicker by 1.5% or more of the drill diameter and smaller than the core thickness of the second core thick part, and is made 0.5% or more thinner than the drill diameter, and TiN, Ti ( CN), (TiAl) N, (TiAlSi) N, (TiAlCr) N, (AlSi) N, (AlCr) N, (TiSi) N, (TiCr) N, DLC, diamond, etc. It is a drill for high-efficiency machining of aluminum characterized by layer coating.

  The invention of the present application is used for drilling of aluminum and the like, and by improving the thinning shape of the center of the drill, it is excellent in chip disposal and centripetalness near the center, reducing cutting resistance and improving welding resistance, enabling stable machining A drill for high-efficiency aluminum machining.

In the present invention, in order to suppress cutting resistance and heat generation at the main cutting edge when machining aluminum or the like, first, the twist angle of the blade groove is set to 25 ° to 40 °, and then thinning is performed at the center of the tip edge. In FIG. 1, by making the intersection formed by the thinning scooping surface and the thinning heel surface into an R shape, chips formed by the thinning cutting edge smoothly flow to the intersection R, and eventually into the drill groove. By flowing in, the welding of the thinning scooping surface due to the accumulation of chips is prevented, and the effect of the thinning cutting edge is maintained, so that the thrust resistance is reduced and the centripetality is excellent and stable drilling can be performed.
Third, in FIG. 1, the curvature of the intersection R formed by the thinning scooping surface and the thinning heel surface is set to 5% or more and 50% or less of the drill core thickness, so that the chips formed by the thinning cutting edge are reduced. It flows smoothly at the intersection R, prevents welding of the thinning scooping surface, and the effect of the thinning cutting edge is maintained, so that the thrust resistance is reduced. If the drill core thickness is 50% or more, the thinning heel surface becomes large, and the risk of chipping and breakage increases due to a decrease in the strength of the drill edge. When the drill core thickness is 5% or less, the chips do not flow smoothly, and the chips accumulate and adhere to the thinning scooping surface. 2 and 3, the bottom position of the intersection R formed by the thinning scooping surface and the thinning heel surface is set within a range of +2 mm to −3 mm from the drill center axis, thereby discharging crushing chips near the center. The thrust resistance can be reduced. If it is +2 mm or more, the remaining width of the flat portion of the chisel during polishing of the blade edge increases, and the thrust resistance increases. If it is −3 mm or less, the bottom position of the intersection R is close to the main cutting edge side, and the risk of chipping increases due to insufficient cutting edge strength. In FIG. 4, the R-shaped portion maximum separation distance B at which the thinning heel surface is connected to the intersection R is 5% or more and 70% of the drill core thickness, so that the chip treatment near the center of the drill is improved and the thrust resistance is reduced. Therefore, high feed machining can be stably performed. When it is 5% or less, the chip disposal is poor, and when it is 70% or more, the drill groove heel surface is reduced and the risk of breakage is increased due to a decrease in drill strength.
Fourth, by reducing the crossing width of the thinning cutting edge to 0.1% or more and 50% or less of the drill diameter toward the center of the drill, the remaining width of the flat part of the chisel during polishing of the cutting edge is reduced, and centripetality is improved. Improves and reduces thrust resistance. When the drill diameter is 50% or more, the flat portion remaining width of the chisel portion increases, and the thrust resistance increases. If the drill diameter is 0.1% or less, the flat portion of the chisel portion is too small and the center portion of the drill is lost.
Fifth, the surface roughness of the thinning scooping surface, the thinning valley bottom R curvature surface, the thinning heel surface, and the chip discharge groove surface was smoothed to Rz 0.2 or more and 1.5 or less, and formed with a thinning cutting blade. Chips are more smoothly discharged from the thinning-curved surface to the thinning R curvature surface, and from the thinning R curvature surface to the chip discharge groove surface, further preventing welding. By smoothing the chip discharge groove, the chips formed by the main cutting edge flow smoothly, so the welding between the part where the main cutting edge and the chip discharge groove are in contact with the chip discharge groove surface can be reduced and chip discharge is also smooth. Thrust resistance can be reduced, but it is difficult to machine the entire drill groove to make Rz 0.2 or less, and chips formed with the main cutting edge and thinning cutting edge do not flow smoothly at Rz 1.5 or more. It may be welded or chip discharge may be hindered.
Sixth, by providing a spiral through hole for fluid supply that supplies cutting fluid, cutting mist, air, etc., lubrication and cooling can be supplied directly to the cutting edge during cutting, Heat generation can be reduced, welding can be reduced, and thermal deformation or the like of the work material can be reduced.
Seventh, in order to stably and efficiently process deep holes exceeding 3 times the diameter, it is necessary to smoothly discharge chips generated at the tip of the cutting edge. In order to prevent chip clogging due to contact with the inner wall of the hole, a first core thick portion and a second core thick portion having a substantially constant thickness are provided with the core thickness of the drill from the blade tip side to the shank side. By making the core thickness of the thick part thicker than the core thickness of the second core thicker by 1.5% or more of the drill diameter, the chip does not contact the inner wall of the machining at the second core thick part. If the core thickness of the second core thickness portion is 1.5% or less of the drill diameter, a sufficient gap may not be obtained between the inner wall of the machined hole and chips may be clogged. In the case of deep hole machining exceeding 10 times the diameter, a first core thick part, a second core thick part, and a third core thick part having a substantially constant thickness are provided from the cutting edge side toward the shank side. The core thickness of one core thick part is 1.5% or more of the drill diameter larger than the core thickness of the second core thick part, and the third core thick part is smaller than the core thickness of the second core thick part. Further, by making the drill diameter 0.5% or more thinner, chip clogging is further prevented, and when the third core thickness is 0.5% or less of the drill diameter, chips may be clogged.
Eighth, TiN, Ti (CN), (TiAl) N, (TiAlSi) N, (TiAlCr) N, (AlSi) N, (AlCr) N, (TiSi) N, (TiCr) N, DLC on the drill surface By forming one or more layers of hard lubricant film such as diamond, the wear resistance is improved against the compressive stress generated on the main cutting edge and thinning cutting edge, and it is possible to cut by lubrication even at the low cutting speed of the thinning cutting edge. Supplementing the action, the welding of the thinning cutting edge, the thinning scooping surface, the portion where the main cutting edge and the chip discharge groove are in contact with the chip discharge groove surface is reduced. It is preferable to mechanically smooth the surface irregularities after coating these hard lubricant films. Examples of the coating method include an arc discharge ion plating method and / or a sputtering ion plating method. Hereinafter, the present invention will be described in detail based on examples.

Example 1
Invention Example 1 is made of cemented carbide and has a drill diameter of 6.0 mm, a groove length of 45 mm, a total length of 100 mm, a drill twist angle of 30 °, a drill tip angle of 130 °, a spiral through hole diameter of 0.7 mm, and a pitch of the spiral through hole. 2.5 mm, first core thickness 1.8 mm, second core thickness 1.65 mm, thinning of FIG. 1, FIG. 2, FIG. 4 is applied to a drill having a pair of margins in the land portion and the heel portion of FIG. Curvature R of the intersection point R composed of the thinning scooping surface and the thinning heel surface R Drill core thickness x 30%, the bottom position of the intersection point R consisting of the thinning scooping surface and the thinning heel surface is -0.6 mm from the center axis of the drill Crossing amount of the thinning cutting edge Drill diameter x 2.5%, R-shaped maximum separation distance B connecting the thinning heel surface to the intersection R is drill core thickness x 50%, thinning scoop surface, thinning valley bottom R curvature surface The surface roughness of the thinning heel surface was Rz 0.6, and the surface roughness of the chip discharge groove surface was Rz 0.8.
In the conventional example 2, the curvature R of the intersection R formed by the thinning scooping surface and the thinning heel surface subjected to the conventional X-type thinning shown in FIG. 6 is connected to the thinning heel surface at the intersection R. A drill having the same specification as that of Example 1 of the present invention was manufactured except that the R-shaped portion maximum separation distance drill core thickness x 0%.
The invention example 1 and the conventional example 2 are used for each of the three, the cutting conditions are Vc 100 m / min, f 0.18 mm / rev, Vf 955 mm / min, the machining hole depth 30 mm, the water-soluble cutting oil is 2.0 Mpa and the shank part spiral Supplied to the through-hole, processed the workpiece AC2A-T6 non-step, measured the maximum width (mm) of the welded material of the thinning cutting edge after processing 100 holes with the left and right cutting edges, and measured the average Value. The measurement was performed as shown in the schematic diagram of FIG. The thrust resistance during the 10th hole processing was also compared. In addition, the present invention example 3 is provided with a pair of margins only on the cutting edge side, and other than that, three drills having the same specifications as the invention example 1 are also investigated, and the state of the cutting edge after the machining is shown in FIG. FIG. 7 shows the results, and Table 1 shows the results and Table 2 shows the thrust resistance values.

  From Table 1, since each of the three examples of the present invention example 1 and the present invention example 3 is smoothly processed by the thinning cutting edge portion, the welded material on the thinning cutting edge and the thinning scoop surface after processing is almost observed. However, as shown in FIG. 8, the width of the welded material is significantly reduced to about 1/20 of that of the conventional example 2, and the effect of the thinning cutting edge is sufficiently continued and the thinning cutting edge By reducing the crossing width, the centripetality is excellent, and from Table 2, the thrust resistance is 450 N in the present invention example 1, 495 N in the present invention example 3, and 925 N in the conventional example 2, which is reduced by about 1/2 of the conventional example 2. It was done. In Conventional Example 2, welds of about 0.8 to 1.0 mm were observed on the thinning cutting edge as shown in FIG. From Table 2, the three cutting edges of the invention example 1 with two pairs of margins are guided by the machined inner wall from four points in comparison with the three of the invention examples 1 with two pairs of margins. Fluctuation of the cutting edge was suppressed and cutting resistance was reduced.

(Example 2)
Furthermore, a comparative investigation of high-feed machining was performed using the same drills as those of Invention Example 1 and Conventional Example 2. Cutting conditions are as follows: cutting speed Vc 150 m / min, feed amount f0.18, 0.3, 0.6, 1.0 mm / rev and feed amount f increased, feed rate Vf1430, 2390, 4780, 7960 mm / min and machining efficiency Then, the water-soluble cutting oil was supplied to the shank part spiral through hole at 2.0 Mpa, the work material AC2A-T6 was non-step processed at a processing depth of 30 mm, and the comparative investigation of the thrust resistance of each third hole was conducted. The results are shown in Table 3.

  From Table 3, the present invention example 1 can smoothly perform chip processing at the thinning cutting edge portion and crushing chip processing near the center of the drill even in high-feed machining. Invention Example 1 was reduced to 1/2 or less. In Conventional Example 2, abnormal noise was generated at a feed amount of f0.6 mm / rev, and breakage occurred at a feed amount of f1.0. The present invention example 1 was further processed at a high feed rate and processed by increasing the feed amounts f1.5, 2.0, 2.5, and 3.0 mm / rev. As a result, the machining was performed up to the feed amount f2.5 mm / rev. Although it was possible to break at a feed amount of f3.0 mm / rev, it was possible to perform high feed and high-efficiency machining 8 times or more than in the conventional example 2.

(Example 3)
Invention Example 4 has the same specifications as Invention Example 1, with a first core thickness of 1.8 mm, a second core thickness of 1.65 mm, and Invention Example 5 with the same specifications as Invention Example 1 with the first core thickness. 1.8 mm, second core thickness 1.75 mm, Invention Example 6 is prepared for each of the first core thickness and the second core thickness of 1.8 mm, two each, cutting conditions Vc 150 m / min, feed rate f0.3mm / rev, water-soluble cutting oil was supplied to the shank part spiral through hole at 2.0Mpa, and the work material AC2A-T6 was non-step processed to a processing depth of 30mm and investigated. As a result, both of the present invention example 4 stably processed 200 holes without problems, while both of the present invention example 5 generated an abnormal sound during processing and broke during processing of 30 holes and 18 holes, In Example 6 of the present invention, both of the two holes produced a large abnormal noise from the first hole and broke during the processing of the second hole and the first hole.

Example 4
Invention Example 7 has the same specifications as Invention Example 1 except for a total length of 200 mm, a groove length of 150 mm, and a core thickness. The first core thickness is 2.0 mm, the second core thickness is 1.85 mm, and the invention example 8 is the present invention. Same specifications as in Example 1, with a first core thickness of 2.0 mm, a second core thickness of 1.85 mm, a third core thickness of 1.75 mm, and the inventive example 9 is 2.0 mm in both the first core thickness and the second core thickness. Prepare two each, cutting conditions Vc 150m / min, feed rate f0.3mm / rev, water-soluble cutting oil is supplied to the shank spiral through hole at 2.0Mpa to machine the workpiece AC2A-T6 Non-step processing was conducted with a depth of 120 mm (20 times the drill diameter). As a result, both of the present invention example 8 stably processed 200 holes without any problem, while the present invention example 7 generated abnormal noise from the vicinity of the processing depth exceeding 70 mm and the cutting power was not stable, It broke at the 14th hole and the 22nd hole, and both of the present invention examples 9 broke at the first hole at a processing depth of about 60 mm.

(Example 5)
Invention Example 10 is made of cemented carbide and has a drill diameter of 5.0 mm, a groove length of 30 mm, a total length of 90 mm, a drill twist angle of 30 °, a drill tip angle of 130 °, a margin of 2 pairs, both the first core thickness and the second core thickness. 1.5 mm, thinned as shown in FIGS. 1, 2 and 4, curvature R at the intersection R composed of a thinning scooping surface and a thinning heel surface R drill core thickness x 30%, thinning scooping surface and thinning The bottom position of the intersection R formed by the heel surface is +0.1 mm from the center axis of the drill, the amount of thinning cutting edge drill diameter x 2%, and the maximum separation distance B of the R-shaped portion to which the thinning heel surface connects at the intersection R Drill core thickness x 50%, thinning scooping surface, thinning valley bottom R curvature surface, thinning heel surface roughness Rz0.5, chip discharge groove surface roughness Rz0.9, Invention Example 11 is thinning scooping Face The surface roughness of the Nning valley bottom R curvature surface and the thinning heel surface is Ry1.3, the surface roughness of the chip discharge groove surface is Ry1.6, the other specifications are the same as those of the present invention example 10, and the cutting conditions are Vc80 m / min. , F0.20 mm / rev, Vf 1000 mm / min, water-soluble cutting oil was investigated by externally supplying the work material AC4B-T6 with a machining depth of 15 mm. As a result, both of Example 10 of the present invention can be machined without a problem of 200 holes, and since the welding of the thinning cutting edge and the thinning scooping surface is small, the effect of the thinning cutting edge is sufficiently continued. Since the hole expansion is stable at +0.02 because it is excellent in mind, the present invention example 11 has a large welding on the thinning cutting edge and thinning scooping surface from the initial stage of machining, and from the fifth hole of machining. The enlargement of the hole was as large as +0.08 to 0.1, and it was also welded to the chip discharge groove surface and broke at the 24th and 31st holes.

(Example 6)
Example 12 of the present invention has the same specifications as Example 1, and Example 13 of the present invention has the same specifications as Example 1 of the present invention. The surface is coated with DLC coating, and mechanically (aero wrap etc.) after coating Prepared with a smoothing process at, and supplied the plant MQL oil in a mist of 10 CC / H at an air pressure of 0.6 Mpa to the spiral through hole of the shank, and the cutting conditions were Vc 100 m / min, A f0.30 mm / rev, Vf1590 mm / min, work material A5052 was machined at a machining depth of 30 mm and investigated. As a result, the thrust resistance at the beginning of machining of Example 12 of the present invention was 670 N, and the initial thrust resistance of Example 13 of the invention was not significantly different from 650 N. However, the thrust resistance at the time of 1000 hole machining was the example of the present invention. No. 12 increased to 730 N, and Example 13 of the invention did not show a large increase of 670 N, and the welding was improved more than Example 12 of the present invention. By applying the thinning of FIGS. 1, 2, 3, and 4 to both Invention Example 12 and Invention Example 13, MQL (mist) machining, which has been difficult to machine, has been stabilized.

(Example 7)
Inventive Example 14 has the same specifications as Inventive Example 1, except that the main cutting edge and the thinning cutting edge are subjected to 0.06 mm honing, the drill surface is coated with TiAlSiN coating, and mechanically (aero wrap etc. after coating) ), The example 15 of the present invention was subjected to honing of 0.06 mm on the main cutting edge and the thinning cutting edge in the same specifications as the conventional example 2, and the drill surface was coated with a TiAlSiN coating, A material that has been subjected to a smoothing process mechanically (aero lap etc.) after coating is prepared, and the cutting conditions are cutting speed Vc 100 m / min, feed amount f 0.18, 0.24, 0.30, 0.40, Raise feed rate f to 0.60 mm / rev, raise feed efficiency Vf 954, 1272, 1590, 2122, 3180 mm / min and increase machining efficiency to 2.0M water-soluble cutting oil. Is supplied to the shank portion a spiral through-hole in a, and machining depth 30mm Nonstep processed workpiece SCM440 steel (hardness HRC 30), confirmed the working effect of the steel. As a result, the present invention example 14 was stably machined to the feed amount f0.18 to 0.6 mm / rev, whereas the present invention example 15 was able to machine the feed amount f0.18 mm / rev, but the feed amount f0. Broken at 24 mm / rev. Invention Example 14 is capable of high feed and high-efficiency machining 2.5 times or more than Invention Example 15 due to the thinning effect of FIG. 1, FIG. 2, FIG. 3, and FIG. It was confirmed that

FIG. 1 shows an example of thinning according to the present invention. FIG. 2 shows an example of thinning according to the present invention. FIG. 3 shows the intersection R curvature bottom minus position of the thinning of the example of the present invention. FIG. 4 shows the intersection R curvature base + position of the thinning of the example of the present invention. FIG. 5 shows the names of each part of the drill. FIG. 6 shows a conventional X-type thinning. FIG. 7 shows a measurement example of the welded material shown in FIGS. FIG. 8 shows the state of the cutting edge after processing of the example of the present invention. FIG. 9 shows the state of the cutting edge after processing of the conventional example. FIG. 10 shows the names of each part of the drill.

Explanation of symbols

1: Drill body 2: Main cutting edge 3: Thinning cutting edge 4: Thinning scooping surface 5: Thinning heel surface 6: Land margin 7: Heel margin 8: Chip discharge groove A: Intersection R curvature B: Separation distance C: Thinning misalignment amount D: intersection R curvature position-range E: intersection R curvature position + range F: thinning cutting edge welded measurement width G: thinning cutting edge welding H: spiral through hole

Claims (7)

In an aluminum high-efficiency machining drill that has a cutting edge at the tip of the drill groove and is thinned at the center when viewed from the side of the cutting edge, the intersection formed by the thinning scoop surface and the thinning heel surface is R The intersection R curvature is 5% or more and 50 or less of the drill core thickness, the connecting portion of the R-shaped part and the thinning heel surface is separated beyond the drill center, and the intersection R position is +2 mm to -3 mm from the drill center axis. Aluminum high-efficiency machining drill characterized by being located in the range of The aluminum high-efficiency machining drill according to claim 1, wherein the maximum separation distance of the R-shaped portion is 5% or more and 70% or less of the drill core thickness. The aluminum high-efficiency drill according to claim 1 or 2, wherein the width of the crossing of the thinning cutting edge is reduced from 0.1% to 50% of the drill diameter toward the center of the drill. Drill for efficiency machining. The aluminum high-efficiency machining drill according to any one of claims 1 to 3, wherein the surface roughness of the thinning scoop surface, the thinning valley bottom R curvature surface, the thinning heel surface, and the chip discharge groove surface is Rz 0.2 or more and 1.5 or less. Aluminum high-efficiency machining drill characterized by The aluminum high-efficiency machining drill according to any one of claims 1 to 4, wherein a spiral through-hole for supplying fluid for supplying cutting fluid, cutting mist, air, or the like is provided. . The aluminum high-efficiency machining drill according to any one of claims 1 to 5, wherein the core thickness of the drill is a first core thick part, a second core thick part having a substantially constant thickness from the cutting edge side to the shank side, One or more third core thick portions, wherein the first core thick portion is thicker than the second core thick portion and is thicker than 1.5% of the drill diameter to increase the third core thickness. A drill for high-efficiency machining of aluminum, characterized in that the thick part is smaller than the core thickness of the second core thick part and is 0.5% or more thinner than the drill diameter. The aluminum high efficiency drill according to any one of claims 1 to 6, wherein the drill surface has TiN, Ti (CN), (TiAl) N, (TiAlSi) N, (TiAlCr) N, (AlSi) N, (AlCr ) A drill for high-efficiency machining of aluminum, characterized in that a hard lubricating film such as N, (TiSi) N, (TiCr) N, DLC, diamond or the like is coated on one or more layers.