Method for manufacturing an end mill

Abstract

In an end mill having three or more odd-numbered gashes provided at the tip of a tool body to form three or more odd-numbered bottom edges, when performing cutting by rotating the tool body at high speed, chatter vibration of the tool body is prevented, the finish of the machined surface of the workpiece is improved, and the chip evacuation property is enhanced. 【Solution means】 In an end mill in which three gashes 11a to 11c are provided at the tip of a tool body 10 to form three bottom edges 13a to 13c, while one bottom edge 13a is formed so as to reach the rotation center o, and the other bottom edges 13b and 13c are formed so as not to reach the rotation center, the size of the gashes provided corresponding to each bottom edge is adjusted to bring the center of gravity of the tool body closer to the rotation axis L.

Description

Technical Field

[0001] The present invention relates to an end mill in which a plurality of gullets are provided at the tip of a tool body to form a plurality of bottom edges. Manufacturing method In particular, in an end mill in which three or more odd-numbered gullets are provided at the tip of a tool body to form three or more odd-numbered bottom edges, one of the odd-numbered bottom edges is formed to reach the rotation center, while the other bottom edges are formed not to reach the rotation center. When the tool body is rotated at high speed for cutting, chatter vibration occurs in the tool body, preventing deterioration of the finish of the machined surface of the workpiece, and at the same time, it is characterized in that the chip dischargeability is improved.

Background Art

[0002] Conventionally, an end mill in which a plurality of gullets are provided at the tip of a tool body to form a plurality of bottom edges has been used for rotating and cutting a workpiece.

[0003] As such an end mill, Patent Documents 1 and 2 disclose an end mill in which three gullets are provided at the tip of a tool body to form three bottom edges, one of the bottom edges is formed to reach the rotation center, while the other two bottom edges are formed not to reach the rotation center.

[0004] Here, as shown in Patent Documents 1 and 2, when three gullets are provided at the tip of a tool body to form three bottom edges, one of the bottom edges is formed to reach the rotation center, while the other two bottom edges are formed not to reach the rotation center, the volume of the gullet forming the bottom edge on the rear side in the rotation direction of the bottom edge formed to reach the rotation center becomes small, causing an offset in the center of gravity of the tool body. When the tool body is rotated at high speed for cutting, chatter vibration occurs in the tool body, deteriorating the finish of the machined surface of the workpiece, and at the same time, the chip dischargeability of the chips cut by the bottom edge on the rear side in the rotation direction of the bottom edge formed to reach the rotation center deteriorates, resulting in problems such as chip jamming.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Disclosure of the Invention

Problems to be Solved by the Invention

[0006] The present invention provides three or more odd-numbered gullets at the tip of a tool body to form three or more odd-numbered bottom edges, and while forming one of the odd-numbered bottom edges to reach the rotation center, the other bottom edges are formed so as not to reach the rotation center. It is an object of the present invention to solve the above problems in an end mill.

[0007] That is, the present invention provides three or more odd-numbered gullets at the tip of a tool body to form three or more odd-numbered bottom edges, and while forming one of the three or more odd-numbered bottom edges to reach the rotation center, the other bottom edges are formed so as not to reach the rotation center. In an end mill, it prevents the center of gravity of the tool body from shifting, suppresses chatter vibration from occurring in the tool body when the tool body is rotated at high speed for cutting, improves the finish of the machined surface of the workpiece, and improves the dischargeability of chips cut by the bottom edge on the rear side in the rotation direction of the bottom edge formed to reach the rotation center, thereby preventing chip jamming. It is characterized in this respect.

Means for Solving the Problems

[0008] In the method for manufacturing an end mill according to the present invention, in order to solve the above problems, three or more odd-numbered gashes are provided at the tip of the tool body to form three or more odd-numbered bottom edges. One of the odd-numbered bottom edges is formed so as to reach the rotation center, while the other bottom edges are formed so as not to reach the rotation center. In the end mill, the size of the gash provided corresponding to each bottom edge is adjusted to bring the center of gravity of the tool body closer to the rotation axis. as The inclination angle in the depth direction and / or the opening angle in the radial direction of the gash provided corresponding to each bottom edge is adjusted. When manufacturing, the inclination angle in the depth direction of the gash forming the bottom blade behind the rotation direction of the bottom blade formed to reach the rotation center and / or the opening angle in the radial direction of the gash is made larger than that of the gash forming the other bottom blade This is done.

[0009] In this way, three or more odd-numbered gashes are provided at the tip of the tool body to form three or more odd-numbered bottom edges. One of the odd-numbered bottom edges is formed so as to reach the rotation center, while the other bottom edges are formed so as not to reach the rotation center. In the end mill, when the size of the gash provided corresponding to each bottom edge is adjusted to bring the center of gravity of the tool body closer to the rotation axis, when the tool body is rotated at high speed for cutting, the occurrence of chatter vibration in the tool body is suppressed, and the finish of the machined surface of the workpiece is improved.

[0010] And in the present invention When adjusting the size of the gash provided corresponding to each bottom edge so as to bring the center of gravity of the tool body closer to the rotation axis as described above ri the inclination angle in the depth direction and / or the opening angle in the radial direction of the gash provided corresponding to each bottom edge is adjusted. is doing so By doing so, variations in the size and volume of the gashes provided corresponding to each bottom edge can be suppressed, the chip discharge performance in the gashes can be made constant, and it becomes possible to prevent chips from clogging.

[0011] Also, in the present invention, when adjusting the inclination angle in the depth direction and / or the opening angle in the radial direction of the gash provided corresponding to each bottom edge so as to bring the center of gravity of the tool body closer to the rotation axis as described above, since the wall thickness of the tool body on the rear side in the rotation direction of the bottom edge formed so as to reach the rotation center is large and the volume of the chip discharge portion is small,As described above The inclination angle in the depth direction and / or the opening angle in the radial direction of the gullet forming the bottom edge behind the rotation direction of the bottom edge formed to reach the rotation center is made larger than that of the gullet forming the other bottom edges, and the gullet forming the bottom edge behind the rotation direction of the bottom edge formed to reach the rotation center is enlarged, suppressing variations in the size and volume of the gullets provided corresponding to the respective bottom edges. did so 。

Advantages of the Invention

[0012] In the present invention, three or more odd-numbered gullets are provided at the tip of the tool body to form three or more odd-numbered bottom edges. While one of the odd-numbered bottom edges is formed to reach the rotation center, the other bottom edges are formed not to reach the rotation center. In the end mill, since the size of the gullet provided corresponding to each bottom edge is adjusted as described above so that the center of gravity of the tool body approaches the rotation axis, when the tool body is rotated at high speed for cutting, chatter vibration generated in the tool body is suppressed, and the finish of the machined surface of the workpiece is improved.

[0013] Further, when adjusting the size of the gullet provided corresponding to each bottom edge so that the center of gravity of the tool body approaches the rotation axis, the inclination angle in the depth direction and / or the opening angle in the radial direction of the gullet provided corresponding to each bottom edge is adjusted, In the present invention and the inclination angle in the depth direction and / or the opening angle in the radial direction of the gullet forming the bottom edge behind the rotation direction of the bottom edge formed to reach the rotation center is made larger than that of the gullet forming the other bottom edges because it was done so Thereby, variations in the size and volume of the gullets provided corresponding to the respective bottom edges are suppressed, the chip discharge performance in each gullet is made constant, and chip jamming can be prevented from occurring.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, an end mill in an embodiment of the present invention Manufacturing method will be specifically described with reference to the accompanying drawings. The end mill in the present invention Manufacturing methodIt is not limited to what is shown in the following embodiments, and can be appropriately modified and implemented without changing the gist thereof.

[0016] In the end mill according to the present embodiment, as shown in FIGS. 1 to 6, on the outer periphery of the tip of the tool body 10, as gash, a first gash 11a, a second gash 11b, and a third gash 11c are successively provided in front of the rotation direction of the tool body 10 so as to be continuous with the corresponding twist grooves 12a, 12b, and 12c, respectively.

[0017] Then, a first bottom edge 13a is provided by the first gash 11a so as to reach the rotation center o of the tool body 10, and a second bottom edge 13b is provided by the second gash 11b provided in front of the rotation direction of the tool body 10 with respect to the first gash 11a so as not to reach the rotation center o of the tool body 10. A third bottom edge 13c is provided by the third gash 11c provided in front of the rotation direction of the tool body 10 with respect to the second gash 11b and behind the rotation direction of the tool body 10 with respect to the first gash 11a so as not to reach the rotation center o of the tool body 10.

[0018] Here, when providing the first chip pocket 11a, the second chip pocket 11b, and the third chip pocket 11c, as shown in FIGS. 3(A), (B) to FIGS. 5(A), (B), when comparing the inclination angles (hereinafter referred to as chip pocket angles) δa, δb, δc in the depth direction of the first to third chip pockets 11a, 11b, 11c with respect to the tip surface perpendicular to the rotation axis L of the tool body 10, the chip pocket angle δc of the third chip pocket 11c behind the first bottom edge 13a in the rotational direction leading to the rotation center o of the tool body 10 is made larger than the chip pocket angle δa of the first chip pocket 11a and the chip pocket angle δb of the second chip pocket 11b. Also, as shown in FIG. 6, when comparing the opening angles (hereinafter referred to as chip pocket opening angles) γa, γb, γc in the radial direction of the tool body 10 in the first to third chip pockets 11a, 11b, 11c, the chip pocket opening angle γc of the third chip pocket 11c behind the first bottom edge 13a in the rotational direction leading to the rotation center o of the tool body 10 is made larger than the chip pocket opening angle γa of the first chip pocket 11a and the chip pocket opening angle γb of the second chip pocket 11b.

[0019] And, as described above, when making the chip pocket angle δc and the chip pocket opening angle γc of the third chip pocket 11c behind the first bottom edge 13a in the rotational direction leading to the rotation center o of the tool body 10 larger than the chip pocket angle δa and the chip pocket opening angle γa of the first chip pocket 11a, and the chip pocket angle δb and the chip pocket opening angle γb of the second chip pocket 11b, the portion of the tool body 10 where the wall thickness increases on the rear side in the rotational direction of the formed first bottom edge 13a leading to the rotation center o is more greatly cut by the third chip pocket 11c, suppressing variations in the size and volume of the first to third chip pockets 11a, 11b, 11c. The center of gravity of the tool body 10 approaches the rotation axis L, and when the tool body 10 is rotated at high speed for cutting, the occurrence of chatter vibration in the tool body 10 is suppressed, and the finish of the machined surface of the workpiece is improved.

[0020] As a result of suppressing variations in the size and volume of each of the first to third chip pockets 11a, 11b, and 11c, the chip discharge performance in each of the first to third chip pockets 11a, 11b, and 11c becomes constant, and the chips cut by each of the first to third bottom edges 13a, 13b, and 13c are appropriately guided through the corresponding first to third chip pockets 11a, 11b, and 11c to the respective twist grooves 12a, 12b, and 12c and discharged, preventing the chips from becoming clogged.

[0021] In addition, in the present embodiment, an end mill provided with three chip pockets 11a, 11b, and 11c of the first to third and three bottom edges 13a, 13b, and 13c of the first to third is shown, but it is also possible to provide five chip pockets and five bottom edges.

[0022] Also, in the present embodiment, an end mill with a constant twist angle and a uniform distribution of bottom edges is shown, but in an end mill with an unequal lead with a variable twist angle or an end mill with an unequal division with an unequal distribution of bottom edges, similar to the above embodiment, the size of the chip pocket provided corresponding to each bottom edge can be adjusted to suppress variations in the size and volume of each chip pocket, and the center of gravity of the tool body can be brought closer to the rotation axis.

Explanation of Reference Numerals

[0023] 10: Tool body 11a: First chip pocket 11b: Second chip pocket 11c: Third chip pocket 12a, 12b, 12c: Twist grooves 13a: First bottom edge 13b: Second bottom edge 13c: Third bottom edge L: Rotation axis o: Rotation center γa: Chip pocket opening angle of the first chip pocket γb: Chip pocket opening angle of the second chip pocket γc: Chip pocket opening angle of the third chip pocket δa: Cash angle of the first cash δb: Cash angle of the second cash δc: Cash angle of the third cash

Claims

[Claim 1] A manufacturing method for an end mill in which an odd number of bottom blades (three or more) are formed by providing three or more odd number of gashes at the tip of a tool body, one of the odd number of bottom blades being formed to reach the center of rotation while the other bottom blades are formed not to reach the center of rotation, wherein the size of the gashes provided corresponding to each of the bottom blades is adjusted to bring the center of gravity of the tool body closer to the rotation axis, and the depth-wise inclination angle and / or radial opening angle of the gashes provided corresponding to each bottom blade are adjusted, wherein the depth-wise inclination angle and / or radial opening angle of the gashes forming the bottom blade behind the bottom blade in the direction of rotation formed to reach the center of rotation is made larger than those of the gashes forming the other bottom blades.

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