Rotary cutting tool

Abstract

The rotary cutting tool has a base member and a cutting edge insert provided on the base member. At least one first groove is provided on the rake face of the cutting edge insert. The first groove has a portion inclined with respect to the rotation axis. The front end of the first groove is provided at the front cutting edge. The rear end of the first groove is provided more inward than the outer peripheral cutting edge, and the unevenness of the outer peripheral cutting edge is less than or equal to 30 μm.

Description

Technical Field

[0001] The present invention relates to a rotary cutting tool. This application claims priority based on Japanese Patent Application No. 2020-050718, filed on March 23, 2020. The entire disclosure of the Japanese patent application is incorporated herein by reference. Background Art

[0002] Currently, for example, rotary cutting tools are disclosed in Japanese Unexamined Patent Application Publication No. 2012-106334 (Patent Document 1), Japanese Utility Model Publication No. 58-44135 (Patent Document 2), and Japanese Utility Model Publication No. 60-165108 (Patent Document 3).

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-106334

[0004] Patent Document 2: Japanese Utility Model Publication No. 58-44135

[0005] Patent Document 3: Japanese Utility Model Publication No. 60-165108 Summary of the Invention

[0006] A rotary cutting tool having a base member and a cutting edge blade provided on the base member, at least one first groove is provided on the rake face of the cutting edge blade, the first groove has a portion inclined with respect to the rotation axis, the front end of the first groove is provided at the front cutting edge or the corner chamfering cutting edge, the rear end of the first groove is provided more inward than the outer peripheral cutting edge, and the unevenness of the outer peripheral cutting edge can be less than or equal to 30 μm. Brief Description of the Drawings

[0007] Figure 1 It is a front view of the rotary cutting tool according to Embodiment 1.

[0008] Figure 2 It is a rear view of the rotary cutting tool according to Embodiment 1.

[0009] Figure 3 It is a right view of the rotary cutting tool according to Embodiment 1.

[0010] Figure 4 It is a left view of the rotary cutting tool according to Embodiment 1.

[0011] Figure 5 It is a top view of the rotary cutting tool according to Embodiment 1.

[0012] Figure 6 It is a bottom view of the rotary cutting tool according to Embodiment 1.

[0013] Figure 7It is a perspective view of the rotary cutting tool according to Embodiment 1.

[0014] Figure 8 It is a view showing an enlarged view of the portion surrounded by Figure 5 VIII in

[0015] Figure 9 It is a view showing an enlarged view of the portion surrounded by Figure 7 IX in

[0016] Figure 10 It is a sectional view taken along the line X-X in Figure 5

[0017] Figure 11 It is a sectional view showing an enlarged view of the portion surrounded by Figure 10 XI in

[0018] Figure 12 It is a front view of the rotary cutting tool according to Embodiment 2.

[0019] Figure 13 It is a front view of the rotary cutting tool according to Embodiment 3.

[0020] Figure 14 It is a front view of the rotary cutting tool according to Embodiment 4.

[0021] Figure 15 It is a front view of the rotary cutting tool according to Embodiment 5.

[0022] Figure 16 It is a view showing an example of the cross-sectional shape of the groove.

[0023] Figure 17 It is a view showing an example of the cross-sectional shape of the groove.

[0024] Figure 18 It is a view showing an example of the cross-sectional shape of the groove.

[0025] Figure 19 It is a view showing an example of the cross-sectional shape of the groove.

[0026] Figure 20 It is a front view of the rotary cutting tool according to Embodiment 6. Detailed Embodiments

[0027] [Problems to be Solved by the Present Invention]

[0028] The current rotary cutting tool has a problem that it is difficult to break the chips.

[0029] [Effects of the Present Invention]

[0030] ​A rotary cutting tool capable of breaking chips can be provided.

[0031] [Description of Embodiments of the Present Invention]

[0032] First, embodiments of the present invention will be described.

[0033] (Embodiment 1)

[0034] Figure 1 is the front view of the rotary cutting tool according to Embodiment 1. Figure 2 is the rear view of the rotary cutting tool according to Embodiment 1. Figure 3 is the right view of the rotary cutting tool according to Embodiment 1. Figure 4 is the left view of the rotary cutting tool according to Embodiment 1. Figure 5 is the top view of the rotary cutting tool according to Embodiment 1. Figure 6 is the bottom view of the rotary cutting tool according to Embodiment 1. Figure 7 is the perspective view of the rotary cutting tool according to Embodiment 1. Figure 8 is an enlarged view showing the part Figure 5 enclosed by VIII in

[0035] As Figures 1 to 8 shown, the rotary cutting tool 1 according to Embodiment 1 has a tool body 2 and a cutting edge insert 10 provided on the tool body 2. At least one first groove 11, 12, 13, 14 is provided on the rake face 100 of the cutting edge insert 10. The first grooves 11, 12, 13, 14 have portions inclined with respect to the rotation axis 9. The front ends 11a, 12a, 13a, 14a of the first grooves 11, 12, 13, 14 are provided at the front cutting edge 110. The rear ends 11b, 12b, 13b, 14b of the first grooves 11, 12, 13, 14 are provided more inward than the outer peripheral cutting edge 120, and the unevenness of the outer peripheral cutting edge 120 is less than or equal to 30 μm.

[0036] The unevenness is measured in the following manner.

[0037] (1) Using a tool microscope, place the tool on the specimen stage so that the outer peripheral cutting edge 120 can be partially seen from a direction perpendicular to the rake face 100 at a magnification of 30 times. While maintaining the state where the optical axis of the tool microscope is perpendicular to the rake face 100, rotate the specimen stage and fix the rotation axis of the specimen stage by aligning the cutting edge ridge line with the reference line of the scale provided on the lens of the tool microscope.

[0038] (2) Move the specimen stage and move it to a position where the reference line of the scale contacts the innermost peripheral part of the unevenness.

[0039] (3) Use an electronic measuring device to read the distance by which the specimen stage is moved in (2) above, and set this distance as the size of the unevenness. In addition, the unevenness referred to here means chips (notches on the ridge line), peeling on the rake face side near the ridge line, and unevenness generated when the groove is formed up to the peripheral cutting edge part, etc., generated on the ridge line part of the peripheral cutting edge.

[0040] The front ends 11a, 12a, 13a, 14a of the grooves 11, 12, 13, 14 are provided at the acting part of the front cutting edge 110, enabling the chip to be segmented in the width direction and reducing the chip width.

[0041] Even if the chip generated by the front cutting edge 110 extends rearward, and there is a part of the first grooves 11, 12, 13, 14 extending in the inclined direction behind the front cutting edge 110, the chip is segmented in the length direction. The chip can be shortened through this segmentation effect. If the distance from the front cutting edge 110 to the first grooves 11, 12, 13, 14 increases, it is difficult to cause this effect.

[0042] Regarding the first grooves 11, 12, 13, 14 Figure 8 With a structure that faces outward as described above, it is only necessary to set the front ends 11a, 12a, 13a, 14a of the first grooves 11, 12, 13, 14 as close as possible to the inner peripheral side (the side closer to the rotating shaft 9) of the acting part of the front cutting edge 110. However, regarding the positions of the front ends 11a, 12a, 13a, 14a of the first grooves 11, 12, 13, 14, the preferred positions change according to the machining conditions and the type of workpiece to be machined. As a result, the width of the chip generated at a position closer to the inner peripheral side than the front ends 11a, 12a, 13a, 14a of the first grooves 11, 12, 13, 14 is reduced. Even if there is no inclined groove behind the front cutting edge 110, the chip with a smaller width is easily curled and broken while curling, and thus is also easily reduced in the length direction. In addition, since the tool of the present invention is a rotary tool for cutting, the chip length of the part of the front cutting edge 110 closer to the outer periphery is longer than that of the part closer to the inner periphery, and the generated chip becomes fan-shaped. Moreover, since this chip is a fan-shaped with a smaller radius, it is easily curled and easily broken. On the other hand, the chip generated at a position closer to the outer peripheral side than the front ends 11a, 12a, 13a, 14a is finely segmented by the segmentation effect of the first grooves 11, 12, 13, 14.

[0043] Figure 9 is an enlarged view showing the part surrounded by Figure 7 IX in Figure 8 and Figure 9As shown, the rear ends 11b, 12b, 13b, 14b of the first grooves 11, 12, 13, 14 do not reach the outer peripheral cutting edge 120. Also, the rear ends 15b, 16b of the other grooves 15, 16 do not reach the outer peripheral cutting edge 120. Therefore, the unevenness of the outer peripheral cutting edge 120 can be made less than or equal to 30 μm. If the unevenness of the outer peripheral cutting edge 120 is large, the uneven shape is transferred to the inner surface of the hole of the workpiece, resulting in a reduction in machining accuracy. The front ends 15a, 16a of the grooves 15, 16 do not reach the front cutting edge 110. The end face shapes of the rear ends 11b, 12b, 13b, 14b of the first grooves 11, 12, 13, 14 can be rectangular, and the direction of their surfaces (the direction orthogonal to the normal of the end face) can be parallel to the front cutting edge 110.

[0044] The base member 2 and the cutting edge blade 10 form the rake face 100. A chip discharge groove 3 is provided in the base member 2. The chip discharge groove 3 is defined by wall surfaces 301, 302. The wall surfaces 301, 302 are configured to extend along the length direction of the base member 2.

[0045] Figure 10 is a cross-sectional view along the Figure 5 X-X line in. Figure 11 is an enlarged cross-sectional view showing the part surrounded by Figure 10 XI in. As Figure 10 and Figure 11 shown, the cutting edge blade 10 is embedded in the base member 2. First grooves 13, 14 and grooves 15, 16 are formed on the surface of the cutting edge blade 10, i.e., the rake face 100. The first grooves 13, 14 and the grooves 15, 16 are rectangular.

[0046] In the rotary cutting tool 1 configured as described above, the first grooves 11, 12, 13, 14 have portions inclined with respect to the rotation axis 9, and the front ends 11a, 12a, 13a, 14a of the first grooves 11, 12, 13, 14 are provided at the front cutting edge 110, so that the chips are easily broken. Also, the rear ends 11b, 12b, 13b, 14b of the first grooves 11, 12, 13, 14 are provided closer to the inside than the outer peripheral cutting edge 120, and the unevenness of the outer peripheral cutting edge 120 is less than or equal to 30 μm, so that the hole of the workpiece can be made smooth.

[0047] (Embodiment 2)

[0048] Figure 12 is a front view of the rotary cutting tool according to Embodiment 2. As Figure 12As shown, in the rotary cutting tool 1 according to the second embodiment, the first groove 11 is provided to face inward. Facing inward means that the first groove 11 is inclined in such a way that it approaches the rotation axis 9 as it moves away from the front cutting edge 110. The opposite, facing outward, means that the first groove 11 is inclined in such a way that it moves away from the rotation axis 9 as it moves away from the front cutting edge 110 relative to facing inward.

[0049] The front end 11a of the first groove 11 is provided at the front cutting edge 110. The rear end 11b of the first groove 11 does not reach the outer peripheral cutting edge 120. The unevenness of the outer peripheral cutting edge 120 is less than or equal to 30 μm.

[0050] Thus, regarding the structure in which the first groove 11 extends inward, it is preferable to arrange the front end 11a of the first groove 11 as close as possible to the outer peripheral side of the front cutting edge 110. As a result, the width of the chip generated at a position more on the outer peripheral side than the front end 11a of the first groove 11 is reduced. Even if there is no inclined groove behind the front cutting edge 110, the narrower chip is easily curled and broken, so it is also easy to reduce in the length direction. In addition, the chip curls toward the inner peripheral side and is entangled with the chip generated on the inner peripheral side of the front end 11a and is thus broken, so the chip is easily reduced in the length direction. When curling toward the outer peripheral side, it comes into contact with the machining surface and the length of the chip is easily shortened, but the width of the chip is small, so the contact force with the machining surface is small and no scar is generated on the machining surface. On the other hand, regarding the chip generated at a position more on the inner peripheral side than the front end 11a, based on the reason that the width of the chip generated on the inner peripheral side described in the first embodiment is reduced, the chip is divided into finer pieces.

[0051] In addition, the chip generated at a portion of the front cutting edge 110 that is more on the inner peripheral side than the front end 11a of the first groove 11 curls and flows slowly on the rake face 100 and is broken if it comes into contact with the groove 11. Or, if the chip that is not broken due to insufficient curling comes into contact with the groove 11, it flows along the groove 11 and toward the rear end 11b of the groove 11. At this time, if there is a rake face 100 and a wall surface 301 that intersects the extending direction of the groove 11 indicated by the line 311 near the rear end 11b of the groove 11, the chip comes into contact with this wall surface 301 and the curling radius is reduced, so an effect of easy chip breaking can be obtained.

[0052] In addition, the curling radius usually reaches about 5 mm even when reduced, and mostly reaches about 10 mm or 20 mm. Therefore, if the interval between the rear end 11b of the groove 11 and the wall surface 301 is less than or equal to 5 mm, the above effect can be fully obtained.

[0053] (Embodiment 3)

[0054] Figure 13This is the front view of the rotary cutting tool according to Embodiment 3. The rotary cutting tool 1 according to Embodiment 3 is different from the rotary cutting tool 1 according to Embodiment 1 in that only one first groove 11 is provided. The front end 11a of the first groove 11 is provided at the front cutting edge 110. The rear end 11b of the first groove 11 does not reach the outer peripheral cutting edge 120. The unevenness of the outer peripheral cutting edge 120 is less than or equal to 30 μm. Since only one first groove 11 is provided, the effect of the groove is reduced compared to the rotary cutting tool 1 of Embodiment 1, but it is easy to manufacture.

[0055] (Embodiment 4)

[0056] Figure 14 This is the front view of the rotary cutting tool according to Embodiment 4. As Figure 14 shown, for the rotary cutting tool 1 according to Embodiment 4, the first groove 11 extends outward, and the second groove 212 extends inward. That is, the rotary cutting tool 1 according to Embodiment 4 is different from the rotary cutting tools 1 according to Embodiments 1 and 2 in that the extending directions of the first groove 11 and the second groove 212 are different. The front ends 11a and 212a both reach the front cutting edge 110. In contrast, the rear ends 11b and 212b both do not reach the outer peripheral cutting edge 120.

[0057] The front ends 11a and 212a of the first groove 11 and the second groove 212 are provided at the front cutting edge 110 and are formed in an open shape in the length direction. The rear ends 11b and 212b of the first groove 11 and the second groove 212 do not reach the outer peripheral cutting edge 120 and are formed in a closed shape in the length direction. The unevenness of the outer peripheral cutting edge 120 is less than or equal to 30 μm. By providing the second groove 212 extending inward and the first groove 11 extending outward, the effects of both the groove extending inward and the groove extending outward can be achieved.

[0058] Moreover, there is an effect that chips are easily finely divided at the intersection of the first groove 11 and the second groove 212.

[0059] (Embodiment 5)

[0060] Figure 15 This is the front view of the rotary cutting tool according to Embodiment 5. As Figure 15 shown, for the rotary cutting tool 1 according to Embodiment 5, two first grooves 11 and 13 extend inward, and one second groove 212 extends outward. The front end 15a of the groove 15 does not reach the front cutting edge 110. All the rear ends 11b, 212b, 13b, and 15b do not reach the outer peripheral cutting edge 120.

[0061] The front ends 11a and 13a of the first grooves 11 and 13 and the front end 212a of the second groove 212 are provided on the front cutting edge 110. The rear ends 11b and 13b of the first grooves 11 and 13 and the rear end 212b of the second groove 212 do not reach the outer peripheral cutting edge 120. The unevenness of the outer peripheral cutting edge 120 is less than or equal to 30 μm.

[0062] Figures 16 to 19 It is a diagram showing an example of the cross-sectional shape of the groove. As Figure 16 shown, the cross-sectional shape of the first groove 11 is V-shaped. The side surface 11d of the groove 11 forms an angle with respect to the rake face 100. As Figure 17 shown, the groove 11 can be composed of a side surface 11d perpendicular to the rake face 100 and a bottom surface 11e parallel to the rake face 100. As Figure 18 shown, a tapered surface 11f is provided near the entrance of the groove 11, and the same side surface 11d and bottom surface 11e can also be provided. Figure 17 Hereinafter, this shape will be referred to as a V shape with a bottom surface. As Figure 19 shown, the groove 11 can be formed in an arc shape. The cross-sectional shape of the groove 11 described above is adopted in each embodiment.

[0063] That is, the cross-sectional shape of the first groove 11 can be any shape of V-shaped, rectangular, or a combined shape of V-shaped and rectangular, or circular.

[0064] (Embodiment 6)

[0065] Figure 20 It is a front view of the rotary cutting tool according to Embodiment 6. As Figure 20 shown, regarding the rotary cutting tool 1 according to Embodiment 6, a corner chamfering cutting edge 130 is provided between the front cutting edge 110 and the outer peripheral cutting edge 120, and the front end 11a of the first groove 11 is provided on the corner chamfering cutting edge 130. The rear end 11b of the groove 11 does not reach the outer peripheral cutting edge 120.

[0066] (Example 1)

[0067] In each example, as a common matter, in order to manufacture the tools of the examples and the comparative examples, a diamond sintered body (hereinafter referred to as PCD) sintered with diamond having an average particle size of 5 μm was brazed to a shaft-shaped base member, and cutting edges were formed at the front end and the outer periphery of the PCD. Therefore, edge grinding was performed using a diamond grinding wheel of #1500. Then, regarding the structure of forming a groove on the rake face of the PCD, a groove was formed on the rake face of the PCD using a high-output pulsed YAG laser with enhanced condensing property by a galvanometer mirror.

[0068] <Differences in the shape and orientation of the first and second grooves>

[0069] The influence of the presence or absence of the first and second grooves and the difference in the shape of the first and second grooves on the chips was investigated. Figures 12 to 14 An example of the basic shape of the tool and the first and second grooves is shown. Figures 16 to 19 Examples of the cross-sectional shapes of the first and second grooves are shown.

[0070] As a comparative example, a structure with a groove up to the outer peripheral cutting edge (tool number 1-b), a structure without the first groove (tool number 101), and a structure with the groove parallel to the outer peripheral cutting edge (tool number 102) were also fabricated. Table 1 shows the shapes, orientations, dimensions, etc. of the first and second grooves.

[0071] [Table 1]

[0072]

[0073] Regarding the "orientation of the groove", "45° outward" means that the first groove extends as shown in Figure 13 and forms an angle of 45° with respect to the rotation axis 9. The angles recorded in the "orientation of the groove" column are all angles with respect to the rotation axis 9. The "discontinuous length W0 of the groove" means the radial length of the part where the groove 11 is formed along the cutting edge 110 of the front end 11a as shown in Figure 12 and disappears.

[0074] Regarding the position where the outermost first groove intersects the front cutting edge measured based on the outer peripheral cutting edge 120, it is 0.3 mm for tool numbers 1 to 1-b in Table 1, 0.3 mm for tool number 1-c, 0.3 mm for tool number 2, 0.3 mm for tool number 3, and 0.3 mm for tool number 102. Regarding the position where the outermost second groove intersects the front cutting edge measured based on the outer peripheral cutting edge 120, it is 0.3 mm for tool number 2 in Table 1.

[0075] Cutting was performed using the above tools under the following conditions, and the chip disposability was evaluated.

[0076] [Cutting Conditions]

[0077] Workpiece: Aluminum alloy (A6061)

[0078] Machined hole: Lower hole diameter is 5 mm and depth is 25 mm

[0079] The hole was finish-machined to a diameter of 10 mm. Therefore, the machining allowance is 2.5 mm on each side.

[0080] Cutting speed: 200 m / min

[0081] Feed rate: 0.2 mm / rev

[0082] In this evaluation, curled chips with a length less than or equal to 5 mm and a width less than or equal to the unilateral machining allowance are judged to be good. The evaluation results are shown in Table 2.

[0083] [Table 2]

[0084]

[0085] The “A” to “C” of the final evaluation in Table 2 are as follows.

[0086] Evaluation A: The width / length (less than or equal to 5 mm) of the chips decreases, and there are no scratches on the machined surface.

[0087] Evaluation B: The length of the chips is slightly larger (5 - 10 mm), and there are no scratches on the machined surface.

[0088] Evaluation C: Scratches are generated on the machined surface, or no scratches are generated, but the chips are long and greater than or equal to 10 mm, and the possibility of generating scratches is extremely high, or no scratches are generated, but even if the chip length is short, it is not divided in the width direction and is large.

[0089] In addition, the evaluations in Tables 4, 6, 8, and 10 below are the same.

[0090] Regarding the tools with tool numbers 1 and 2, the width of the chips is less than the machining allowance, and the chip length is also short - divided into 3 mm. Regarding the tool with tool number 3 whose cross - sectional shape of the first groove is semi - circular, compared with other first - groove shapes, the depth of the first groove is shallower relative to the width of the first groove, so it is considered that the chip width cannot be reduced. In addition, for the same reason, the effect of shortening the chip length is smaller than that of other first - groove shapes, but it has a curling effect, and the chip length is shortened to 3 mm.

[0091] In contrast, regarding the tool with tool number 101 without the first groove, the chip width is the same as the machining allowance, the chip length is 16 mm and it is not curled, and it does not have the effect of chip breaking. Based on the above results, it can be considered that the effect of chip breaking is not caused by machining conditions, but by the difference in the first - groove shape.

[0092] Regarding the tool with tool number 1 - c, chip scratches are found on the rake face 100 and the wall surface 301 that intersects the direction in which the groove 11 extends, and it is confirmed that it has an effect on chip breaking. Therefore, the chips generated at the front cutting edge 110 flow along the groove 11 and contact the wall surface 301 near the rear end 11b of the groove 11, resulting in the effect of chip breaking.

[0093] Moreover, if the unevenness of the peripheral cutting edge exceeds 30 μm, scratches will be generated on the machined surface and the surface roughness will decrease.

[0094] (Example 2)

[0095] (Difference in the angle of the first groove)

[0096] In this embodiment, an experiment was conducted on the influence of the angle of the first groove on the breaking of chips.

[0097] In order to confirm the difference in chip breaking caused by the difference in the angle of the first groove, based on the tool shape of Example 1, the number of the first grooves was set to 1.

[0098] Tools were made such that the angle of the first groove was parallel to the rotation axis (0°) and tools with the angle changed within the range of 3° to 87°. Table 3 shows the shape, orientation, dimensions, etc. of the first groove. The front ends of the first grooves all intersect with the front cutting edge.

[0099] [Table 3]

[0100]

[0101] There are shape and manufacturing limitations at the position where the cutting edges intersect, so there are three types of tools with distances from the outer peripheral cutting edge of 1.0 mm, 1.5 mm, and 2.0 mm using the tool. Specifically, tool numbers 103, 11, 12, 13, and 14 in Table 3 are 1 mm, tool number 15 is 1.5 mm, and tool number 16 is 2 mm.

[0102] Similar to tool number 1 of Example 1, the cross-sectional shape of the first groove is Figure 18 of the shape, and the width W of the first groove is 0.17 mm.

[0103] In addition, the width WO of the interrupted part of the front cutting edge generated by the intersection of the first groove and the front cutting edge varies according to the angle of the first groove, but can be calculated.

[0104] Cutting was performed under the following conditions using the above tools, and the chip processability was evaluated.

[0105] [Cutting conditions]

[0106] The cutting conditions are as follows.

[0107] Workpiece to be cut: Aluminum alloy (A6061)

[0108] Machined hole: The lower hole diameter is 5 mm and the depth is 25 mm

[0109] The hole was finish-machined to 10 mm. Therefore, the machining allowance is 2.5 mm on one side.

[0110] Cutting speed: 200 m / min

[0111] Feed rate: 0.2 mm / rev

[0112] This evaluation is also the same as that in Example 1. A curled chip with a length less than or equal to 5 mm and a width less than or equal to the unilateral machining allowance is judged to be good. Among them, the judgment was made considering the generation conditions such as vibration during machining. The evaluation results are shown in Table 4.

[0113] [Table 4]

[0114]

[0115] Regarding the tool with an angle of 3° for tool number 11, the chip is curled but the length is not significantly shortened, so the final evaluation is B. Regarding the tools with angles of 5° to 85° for tool numbers 12 to 15, the chip width and chip length both show the effect of segmentation at the first groove.

[0116] Regarding the tool with an angle of 87° for tool number 16, it has the effect of chip segmentation, but a slight vibration condition was found during machining near the bottom of the hole. It can be considered that this is because the size of W is very large, greater than or equal to 3.25 mm, and the cutting resistance of this part increases, resulting in vibration.

[0117] From this result, it can be known that it is preferable for the first groove to have an angle greater than or equal to 5° and less than or equal to 85° with respect to the rotation axis.

[0118] (Example 3)

[0119] <Difference in the depth of the first groove>

[0120] In this example, the influence of the depth of the first groove on the chip was investigated.

[0121] Regarding the tool shape, the tool shape of tool number 1 in Example 1 was set as the basic shape, and tools with the depth of the first groove changed were made. The shape, orientation, dimensions, etc. of the first groove are shown in Table 5.

[0122] [Table 5]

[0123]

[0124] The width W of the first groove and the interval S of the first groove are the same as those of tool number 1, and the position where the outermost first groove intersects the front cutting edge is set at a position 0.3 mm away from the outer periphery.

[0125] In addition, the position on the inner peripheral side of the first groove is set at a position 2.5 mm away from the outer periphery, and the total number of the first grooves including the tool is 3.

[0126] Using the above tools, cutting machining was performed under the following conditions, and the chip processability was evaluated.

[0127] [Cutting conditions]

[0128] Workpiece to be machined: Aluminum alloy (A6061)

[0129] Hole to be machined: The diameter of the lower hole is 5 mm and the depth is 25 mm

[0130] The hole is finish-machined to 10 mm. Therefore, the machining allowance is 2.5 mm on each side.

[0131] Cutting speed: 200 m / min

[0132] Feed rate: 0.2 mm / rev

[0133] This evaluation is also the same as that of Example 1. The evaluation results are shown in Table 6.

[0134] [Table 6]

[0135]

[0136] Regarding the tools with the first groove depth of 0.01 mm to 0.8 mm for tool numbers 22 to 26, the chips are curled and finely segmented.

[0137] From this result, it can be seen that it is preferable that the depth of the first groove is greater than or equal to 0.01 mm and less than or equal to 0.8 mm.

[0138] (Example 4)

[0139] <Difference in the width of the first groove>

[0140] In this example, an experiment was conducted on the influence of the difference in the width W of the first groove on the chips.

[0141] Regarding the tool shape, based on the shape of tool number 1 in Example 1, tools with different widths of the first groove between 0.01 mm and 0.50 mm were made. Table 7 shows the shape, orientation, dimensions, etc. of the first groove.

[0142] [Table 7]

[0143]

[0144] The depth D of the first groove and the interval S of the first grooves are the same as those of the tool with tool number 1. The position where the outermost first groove intersects the front cutting edge is set at a position 0.3 mm away from the outer periphery.

[0145] Tool number 34 is the same as the tool with tool number 1 made in Example 1.

[0146] The outermost peripheral part of the first groove is set at a position 2.5 mm away from the outer periphery. Therefore, the number of the first grooves varies according to the width of the first groove.

[0147] Cutting was performed under the following conditions using the above tool, and the chip disposability was evaluated.

[0148] [Cutting Conditions]

[0149] Workpiece to be cut: Aluminum alloy (A6061)

[0150] Machined hole: Lower hole diameter is 5 mm and depth is 25 mm

[0151] This hole was finish-machined to 10 mm. Therefore, the machining allowance is 2.5 mm on each side.

[0152] Cutting speed: 200 m / min

[0153] Feed rate: 0.2 mm / rev

[0154] This evaluation is also the same as that of Example 1. The evaluation results are shown in Table 8.

[0155] [Table 8]

[0156]

[0157] Regarding the tools with tool numbers 32 to 36, the chips were curled and broken, and smaller chips were obtained.

[0158] (Example 5)

[0159] [Difference in the Spacing of the First Groove]

[0160] In this example, an experiment was conducted on the influence of the difference in the spacing S of the first groove on the chips.

[0161] The tool shape was made with the shape of tool number 1 in Example 1 as the basic shape, and a structure with different spacings of the first groove was made. Table 9 shows the shape, orientation, dimensions, etc. of the first groove.

[0162] [Table 9]

[0163]

[0164] The depth D and width W of the first groove are the same as those of tool number 1. The position where the outermost first groove intersects the front cutting edge is set at a position 0.3 mm away from the outer peripheral part.

[0165] Tools with different first groove spacings S between 0.10 mm and 2.00 mm were made. Tool number 44 is the same tool as tool number 1 in Example 1.

[0166] The outermost peripheral part of the first groove is set at a position 2.5 mm away from the outer peripheral part. Therefore, the number of the first grooves is different according to the first groove spacing.

[0167] Cutting was performed using the above tool under the following conditions, and the chip disposability was evaluated.

[0168] [Cutting Conditions]

[0169] Workpiece to be cut: Aluminum alloy (A6061)

[0170] Machined hole: Lower hole diameter is 5 mm and depth is 25 mm

[0171] This hole was finish-machined to 10 mm. Therefore, the machining allowance is 2.5 mm on each side.

[0172] Cutting speed: 200 m / min

[0173] Feed rate: 0.2 mm / rev

[0174] This evaluation is also the same as that of Example 1. The evaluation results are shown in Table 10.

[0175] [Table 10]

[0176]

[0177] Regarding the tools with tool numbers 43 to 45, the chips were curled and broken, and small chips were obtained.

[0178] Even for the tool with a first groove interval of 0.10 mm for tool number 42, the front cutting edge is nearly comb-shaped, so slight chip welding was found, but the welding was less, so the effect of curling and breaking the chips was not reduced.

[0179] The embodiments and examples disclosed herein are illustrative in all respects and should be considered not limited. The scope of the present invention is represented not by the above embodiments but by the claims, and it is intended to include the scope equivalent to the claims and all modifications within the scope.

[0180] Industrial Applicability

[0181] The rotary cutting tool can be suitably used as a drill or reamer for use in the fitting hole machining of aluminum alloys and non-ferrous metals.

[0182] Explanation of Reference Numerals

[0183] 1...Rotary cutting tool, 2...Substrate, 9...Rotating shaft, 10...Cutting edge insert, 11, 12, 13, 14...First groove, 15, 16...Groove, 11a, 12a, 13a, 14a, 15a, 16a, 212a...Front end, 11b, 12b, 13b, 14b, 15b, 16b, 212b...Rear end, 11d...Side surface, 11e...Bottom surface, 11f...Tapered surface, 100...Rake face, 110 Front cutting edge, 120...Peripheral cutting edge, 130...Corner chamfering cutting edge, 212...Second groove, 301, 302...Wall surface, 311...Line.

Claims

1. A rotary cutting tool having a base member and a cutting edge blade provided on the base member, wherein, the base member and the cutting edge blade constitute a rake face, a chip discharge groove is provided in the base member, the chip discharge groove is defined by a first wall surface and a second wall surface, and the first wall surface and the second wall surface are configured to extend along the length direction of the base member, the cutting edge blade is embedded in the base member, and at least one first groove is provided on the rake face of the cutting edge blade, the first groove has a portion inclined with respect to the rotation axis, the front end of the first groove is provided at the acting portion of the front cutting edge to break the chip in the width direction and reduce the chip width, the rear end of the first groove is provided closer to the inner side than the outer peripheral cutting edge, and the unevenness of the outer peripheral cutting edge in the direction parallel to the rake face is less than or equal to 30 μm, at least one second groove is provided on the rake face of the cutting edge blade, a corner chamfer cutting edge is provided between the front cutting edge and the outer peripheral cutting edge, the front end of the second groove is provided at the front cutting edge or the corner chamfer cutting edge, the rear end of the second groove is provided closer to the inner side than the outer peripheral cutting edge, and the first groove and the second groove intersect, the unevenness refers to the chips generated at the ridge line portion of the outer peripheral cutting edge, the peeling on the rake face side near the ridge line, and the unevenness generated when the groove is formed to the outer peripheral cutting edge portion, and the unevenness is measured in the following manner: (1) Using a tool microscope, place the tool on the specimen stage in such a way that a part of the outer peripheral cutting edge can be seen from a direction perpendicular to the rake face at a magnification of 30 times; while maintaining the state where the optical axis of the tool microscope is perpendicular to the rake face, rotate the specimen stage, align the cutting edge ridge line with the reference line of the scale provided on the lens of the tool microscope, and fix the rotation axis of the specimen stage; (2) Move the specimen stage and move it to a position where the reference line of the scale contacts the innermost peripheral side portion of the unevenness; and (3) Use an electronic measuring instrument to read the distance by which the specimen stage is moved in the above (2), and set this distance as the size of the unevenness, the depth of the first groove is greater than or equal to 0.01 mm and less than or equal to 0.8 mm, the width of the first groove is greater than or equal to 0.01 mm and less than or equal to 0.5 mm.

2. The rotary cutting tool according to claim 1, wherein, the first groove is inclined in such a way that it faces the inner peripheral side as it goes from the front end to the rear end, and near the rear end of the first groove, a wall surface intersecting the rake face and the extending direction of the first groove is provided.

3. A rotary cutting tool having a base member and a cutting edge blade provided on the base member, wherein, the base member and the cutting edge blade constitute a rake face, a chip discharge groove is provided in the base member, the chip discharge groove is defined by a first wall surface and a second wall surface, and the first wall surface and the second wall surface are configured to extend along the length direction of the base member, The cutting edge blade is embedded in the base member, and at least one first groove is provided on the rake face of the cutting edge blade. The first groove has a portion inclined with respect to the rotation axis. The front end of the first groove is provided at the acting portion of the front cutting edge so as to break the chip in the width direction and reduce the chip width. The rear end of the first groove is provided closer to the inner side than the outer peripheral cutting edge, and the unevenness in the direction parallel to the rake face of the outer peripheral cutting edge is less than or equal to 30 μm. The first groove is inclined so as to face the inner peripheral side as it goes from the front end to the rear end. Near the rear end of the first groove, a wall surface intersecting with the rake face and the extending direction of the first groove is provided. The unevenness refers to debris generated at the ridge line portion of the outer peripheral cutting edge, peeling on the rake face side near the ridge line, and unevenness generated when the groove reaches the outer peripheral cutting edge portion. The unevenness is measured in the following manner: (1) Using a tool microscope, place the tool on the specimen stage in such a way that a part of the outer peripheral cutting edge can be seen from a direction perpendicular to the rake face at a magnification of 30 times; while maintaining the state where the optical axis of the tool microscope is perpendicular to the rake face, rotate the specimen stage so that the cutting edge ridge line coincides with the reference line of the scale provided on the lens of the tool microscope, and fix the rotation axis of the specimen stage. (2) Move the specimen stage and move it to a position where the reference line of the scale contacts the innermost peripheral side portion of the unevenness. And (3) Use an electronic measuring instrument to read the distance by which the specimen stage is moved in the above (2), and set this distance as the size of the unevenness. The depth of the first groove is greater than or equal to 0.01 mm and less than or equal to 0.8 mm. The width of the first groove is greater than or equal to 0.01 mm and less than or equal to 0.5 mm.

4. The rotary cutting tool according to claim 3, wherein The first groove is linear and has an angle greater than or equal to 5° and less than or equal to 85° with respect to the rotation axis.

5. The rotary cutting tool according to claim 3, wherein A plurality of the first grooves are provided, and the interval between the plurality of first grooves is greater than or equal to 0.1 mm and less than or equal to 2 mm.

6. The rotary cutting tool according to claim 3, wherein The cross-sectional shape of the first groove is V-shaped, rectangular, or a shape obtained by combining V-shaped and rectangular shapes.

7. The rotary cutting tool according to claim 3, wherein The end face shape of the rear end of the first groove is rectangular. The direction orthogonal to the normal line of this end face is parallel to the front cutting edge.

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