Milling cutters, crankshaft milling cutters and methods for manufacturing a crankshaft

Abstract

Milling cutter (13, 23) for milling a crankshaft blank (2) which has a journal (PJ1) and a counterweight (CW) connected to the journal (PJ1), wherein the milling cutter (13, 23) comprises: an annular main body part (14) centered on a predetermined axis center (AX); a first cutting insert (15, 25) attached to a circumferential surface (14S) of the main body part (14); and a second cutting plate (16, 26) which is attached to the circumferential surface (14S) of the main body part (14), wherein, viewed in a top view of the circumferential surface (14S), the first cutting plate (15, 25) projects beyond a center line of the main body part (14) in an axial direction parallel to the axis center (AX), and, viewed in a top view of the circumferential surface (14S), the second cutting plate (16, 26) is spaced axially from the center line of the main body part (14), wherein the first cutting plate (15,25) comprising a blade part (31) for an outer circumferential surface (S1) used for milling the outer circumferential surface (S1) of the pin (PJ1), and a blade part (32) for a side surface (S5) used for milling a side surface (S5) of the counterweight (CW), wherein the second cutting insert (16, 26) comprises a blade part (34) for a groove (S2) used for milling a groove (S2) on the outer circumferential surface (S1) of the pin (PJ1).

Description

Technical field The present invention relates to a milling cutter, a crankshaft milling cutter and a method for manufacturing crankshafts. State of the art For the state of the art, reference is made to the following documents: DE 10 2012 102 747 A1 , DE 195 46 197 C1 , JP 2000 - 126 922 A , DE 10 2008 039 135 A1 , DE 10 2005 038 021 A1 , JP 2007 - 276 083 A , JP 2001 - 219 313 A . From JP 2001 - 293 610 A, a crankshaft milling machine is known that mills a crankshaft blank using a cutter. It performs two steps: one to cut the outer circumferential surface of a journal and another to form grooves at both ends of the journal's outer circumferential surface. Two types of cutters are used in the milling process: one for cutting the journal's outer circumferential surface and one for forming the grooves at both ends of the journal's outer circumferential surface. Summary of the invention Problem that the invention is intended to solve However, there is a problem in that the work efficiency of the crankshaft milling machine described in JP 2001 - 293 610 A is low, as there is a need to exchange the two types of milling cutters according to the journal width of the crankshaft. In view of the above-mentioned prerequisites, one object of the present invention is to provide a milling cutter, a crankshaft milling cutter and a manufacturing method for crankshafts that enable an improvement in work efficiency during milling. Solution to the problem According to a first aspect of the present invention, a milling cutter for milling a crankshaft blank is proposed, which has a journal and a counterweight connected to the journal, and comprises an annular main body, a first cutting insert, and a second cutting insert. The annular main body is centered on a predetermined axial center. The first cutting insert is attached to a circumferential surface of the main body. The second cutting insert is also attached to the circumferential surface of the main body. Viewed from a top view of the circumferential surface, the first cutting insert projects beyond a center line of the main body in an axial direction parallel to the axial center. Viewed from a top view of the circumferential surface, the second cutting insert is spaced axially from the center line of the main body.The first cutting insert has a blade section for an outer circumferential surface, used for milling the outer circumferential surface of the tenon, and a blade section for a side surface, used for milling a side surface of the counterweight. The second cutting insert has a blade section for a groove, used for milling the groove on the outer circumferential surface of the tenon. Preferred embodiments are defined in dependent claims 2 to 6. According to the present invention, a method for manufacturing a crankshaft is further proposed, wherein the milling cutter according to the first aspect mentioned above is used in the method and the method comprises the following steps: milling the side surface of the counterweight of the crankshaft blank with the blade part for a side surface of the first cutting plate, milling the outer circumferential surface of the journal of the crankshaft blank with the blade part for the outer circumferential surface of the first cutting plate, and forming the groove on the outer circumferential surface of the journal of the crankshaft blank with the blade part for the groove. Effects of the invention According to the present invention, a milling cutter, a crankshaft milling cutter and a manufacturing method for crankshafts are provided, which enable an improvement in the work efficiency of milling. Brief description of the characters Fig. 1 is a cross-section of a milling unit assembly in the crankshaft milling cutter. Fig. 2 is a perspective view of the crankshaft assembly. Fig. 3 is an enlarged partial view of a first milling cutter in a top view from the side. Fig. 4 is an enlarged partial view of the inside of the first milling cutter in a top view from the direction of arrow A in Fig. 3. Fig. 5 is a virtual cross-section showing a first cutting insert and a second cutting insert intersecting each other in the first milling cutter. Fig. 6 is a view illustrating milling with the first milling cutter and a second milling cutter. Fig. 7 is a view illustrating milling with the first milling cutter and a second milling cutter. Fig. 8 is a view illustrating milling with the first milling cutter and a second milling cutter. Fig. 9 is a view illustrating milling with the first milling cutter and a second milling cutter.Figure 10 shows a view illustrating milling with the first cutter and a second cutter. Figure 11 is a virtual cross-section showing a first cutting insert, a second cutting insert, and a third cutting insert intersecting in the first cutter. Description of embodiments (Structure of the crankshaft cutter 1) Fig. 1 is a cross-section of a milling unit 10 in a crankshaft milling cutter 1 according to one embodiment. Fig. 2 is a perspective view of the structure of a crankshaft 2a, which was produced by milling a crankshaft blank (hereinafter referred to as the "workpiece") 2. The crankshaft milling machine 1 is a so-called internal crankshaft milling machine. The crankshaft milling machine 1 performs milling operations on the workpiece 2 using an internal blade of the milling unit 10. According to the present embodiment, workpiece 2 is an untreated crankshaft for an inline 4-cylinder engine. However, workpiece 2 is not limited to an untreated crankshaft for an inline 4-cylinder engine, and it can be various types of untreated crankshafts for an inline 3-cylinder engine, an inline 6-cylinder engine, an inline 8-cylinder engine, and the like. Workpiece 2 is arranged along an axis center AX. Workpiece 2 is clamped by a pair of clamping devices, which are not shown in the drawings. Workpiece 2 is formed into a multi-axis bar shape. In its untreated state, workpiece 2 is formed larger than the finished crankshaft 2a, taking into account the machining clearance. As shown in Fig. 2, the finished crankshaft 2a product has a front shaft FS, main journals MJ (first to fifth main journals MJ1-MJ5), pin journals PJ (first to fourth pin journals PJ1-PJ4), counterweights CW (first to eighth counterweights CW1-CW8), a rear flange RF, and journal thrust bearings JS (first to seventeenth journal thrust bearings JS1-JS17). However, only nine of the first to seventeenth journal thrust bearings JS1-JS17 are visible in Fig. 2. The pin stubs PJ are arranged between two of the main stubs MJ. The counterweights CW are arranged between the pin stubs PJ and the main stubs MJ. The stub thrust bearings JS are formed between the counterweights CW and the pin stubs PJ, as well as between the counterweights CW and the main stubs MJ. The main stubs MJ and the pin stubs PJ each represent examples of "stubs" according to the present embodiment. The milling unit 10 is arranged between two clamping heads, which are not shown in the drawings. The workpiece 2 is located on the inside of the milling unit 10. The milling unit 10 can rotate relative to the workpiece 2. A fixed workpiece format can be used, in which the milling unit 10 rotates around the fixed workpiece 2, or a rotating workpiece format, in which the workpiece 2 rotates on the inside of the fixed milling unit 10. As shown in Fig. 1, the milling unit 10 is equipped with a first milling unit 11 and a second milling unit 21. The first milling unit 11 has a first adapter 12 and a first milling cutter 13. The second milling unit 21 has a second adapter 22 and a second milling cutter 23. The first adapter 12 is ring-shaped. The first adapter 12 is capable of moving along an axis parallel to the axis center AX. The first milling cutter 13 is attached to an opening on the side of the first adapter 12 facing the second adapter 22. The first cutter 13 is attached to the first adapter 12. The first cutter 13 can be attached to and removed from the first adapter 12. The first cutter 13 is a so-called internal-cutting cutter type. The first cutter 13 has a plurality of first cutting inserts 15 and a plurality of second cutting inserts 16, which are attached to the inside of a main body part 14. As shown in Fig. 1, the second cutting inserts 16 are located on the side of the first milling cutter 13 facing the second milling cutter 23. The configuration of the first milling cutter 13 is described below. The second adapter 22 is ring-shaped. The second adapter 22 can move axially. The second milling cutter 23 is attached to an opening on the side of the second adapter 22 facing the first adapter 12. The second cutter 23 is attached to the second adapter 22. The second cutter 23 can be attached to and removed from the second adapter 22. The second cutter 23 is a so-called internal-cutting cutter type. The second cutter 23 has a plurality of first cutting inserts 25 and a plurality of second cutting inserts 26, which are attached to the inside of a main body part 24. The second milling cutter 23 has a similar design to the first milling cutter 13. The second milling cutter 23 has a design that is reversed by rotating the first milling cutter 13 by 180 degrees. The second cutting inserts 26 are located on the side of the second milling cutter 23 facing the first milling cutter 13. The second cutting inserts 26 are oriented towards the first milling cutter 13. (Construction of the first milling cutter 13 and the second milling cutter 23) The construction of the first milling cutter 13 and the second milling cutter 23 is explained here with reference to the drawings. As already explained above, the second milling cutter 23 has a similar construction to the first milling cutter 13. Therefore, the following discussion will mainly focus on the construction of the first milling cutter 13. Fig. 3 is an enlarged partial view of the first milling cutter 13, as seen in a side view from a top view. Fig. 4 is an enlarged partial view of the inside of the first milling cutter 13, as seen in a top view from the direction of arrow A in Fig. 3. Fig. 5 is a virtual cross-section showing the first cutting inserts 15 and the second cutting inserts 16 of the first milling cutter 13 overlapping each other. The first milling cutter 13 is shown in the state of approaching the first pin tang PJ1 in Fig. 5. The first milling cutter 13 is a milling tool for milling the workpiece 2. The first milling cutter has the main body part 14, the plurality of first cutting inserts 15 and the plurality of second cutting inserts 16. The main body part 14 is ring-shaped and centered on the axis center AX (see Fig. 1). The main body part 14 has an inner circumferential surface 14S, an outer circumferential surface 14T, a first side surface 14P, and a second side surface 14Q. The inner circumferential surface 14S and the outer circumferential surface 14T extend circumferentially around the axis center AX. The inner circumferential surface 14S is an example of a "circumferential surface" according to the present embodiment. The first side surface 14P and the second side surface 14Q are both connected to the inner circumferential surface 14S and the outer circumferential surface 14T, respectively. The second side surface 14Q faces the second cutter 23 (see Fig. 1). The first cutting inserts 15 are attached to the inner circumferential surface 14S of the main body part 14. The first cutting inserts 15 can be attached and removed using fasteners such as screws and the like. The first cutting inserts 15 are formed as flattened and substantially rectangular shapes. The first cutting inserts 15 are arranged horizontally and substantially parallel to the circumferential direction. The number of first cutting inserts 15 can be changed if necessary. As shown in Figures 3 and 4, the first cutting inserts 15 are arranged at uniform intervals in the circumferential direction. The distances between the first cutting inserts 15 can be changed if necessary. As shown in Figure 5, the first cutting inserts 15 project axially over a center line 14a of the main body part 14. A portion of each of the first cutting inserts 15 is exposed towards the first side surface 14P. A portion of each of the first cutting inserts 15 projects axially out of the first side surface 14P. The first cutting inserts 15 are not exposed towards the second side surface 14Q. As shown in Fig. 5, the first cutting inserts 15 have an outer circumferential blade part 31, a side blade part 32, and a stepped blade part 33. The circumferential blade part 31 is used for milling an outer circumferential surface S1 of the first pin PJ1. The outer circumferential blade part 31 is arranged substantially parallel to the axial direction. The side blade part 32 is used for milling a side surface S5 of the first counterweight CW1. The side blade part 32 is arranged substantially perpendicular to the axial direction. The stepped blade part 33 is used for milling a step S4 of the second pin axial bearing JS2. The stepped blade part 33 is connected to the circumferential blade part 31 and the side blade part 32. The stepped blade part 33 is curved or bent at an angle corresponding to step S4.The lower end portion of the stepped blade section 33 can overlap with the end portion in the axial direction of the outer circumferential blade section 31. The upper end portion of the stepped blade section 33 can overlap with the lower end portion of the side-surface blade section 32. The second cutting inserts 16 are attached to the inner circumferential surface 14S of the main body part 14. The second cutting inserts 16 can be attached and removed using fasteners such as screws or similar. The second cutting inserts 16 are formed in flattened and essentially rectangular shapes. The second cutting inserts 16 are arranged vertically and essentially perpendicular to the circumferential direction. The number of second cutting inserts 16 can be changed if necessary. As shown in Figures 3 and 4, the second cutting inserts 16 are arranged at equal intervals in the circumferential direction. The distances between the second cutting inserts 16 can be varied accordingly. The second cutting inserts 16 are arranged alternately with the first cutting inserts 15 in the circumferential direction. As shown in Fig. 5, the second cutting inserts 16 do not project beyond the centerline 14a of the main body part 14 in the axial direction. The second cutting inserts 16 are located closer to the side of the main body part 14 facing the second milling cutter 23. The second cutting inserts 16 are not exposed towards the first side surface 14P. The first cutting inserts 15 are exposed towards the second side surface 14Q. However, the second cutting inserts 16 do not project from the second side surface 14Q in the axial direction. As shown in Fig. 5, a pointed end 16a of each second cutting insert 16 projects further in the radial direction, aligned with the axis center AX, than the first cutting inserts 15. In the present embodiment, the second cutting inserts 16 are attached to the inner circumferential surface 14S of the main body part 14. Consequently, the pointed end 16a of the second cutting inserts 16 project further inwards than the first cutting inserts 15. As shown in Fig. 5, the second cutting inserts 16 have a groove-blade part 34 and a side-face blade part 35. The groove-blade part 34 is used to form a groove S2 on an end part in the axial direction of the outer circumferential surface S1 of the first pin journal PJ1. The groove-blade part 34 is curved or bent at an angle corresponding to the groove S2. The side-face blade part 35 is used to cut a side surface S3 of the third pin axial bearing JS3. The side-face blade part 35 is connected to the groove-blade part 34 from above and is arranged substantially perpendicular to the axial direction. The side-face blade part 35 is provided flush with the second side surface 14Q of the main body part 14. The lower end part of the side surface blade part 35 can extend beyond the upper end part of the groove blade part 34. The configuration of the second milling cutter 23 is described below. As shown in Fig. 1, the second milling cutter 23 has the main body part 24, the majority of the first cutting inserts 25 and the majority of the second cutting inserts 26. The main body part 24 of the second milling cutter 23 has the same configuration as the main body part 14 of the first milling cutter 13. The first cutting inserts 25 of the second milling cutter 23 each have the outer circumferential blade part 31, the side blade part 32, and the stepped blade part 33 in the same way as the first cutting inserts 15 of the first milling cutter 13. The side blade part 32 of each first cutting insert 25 is used for cutting the outer circumferential surface S1 of the first pin tang PJ1. The side blade part 32 of each first cutting insert 25 is used for cutting the side surface S5 of the second counterweight CW2. The stepped blade part 33 is used for cutting the step S4 of the third pin axial bearing JS3. The second cutting inserts 26 of the second milling cutter 23 each have the groove-blade portion 34 and the side-face blade portion 35, like the second cutting inserts 16 of the first milling cutter 13. The groove-blade portion 34 of each second cutting insert 26 is used to form the groove S2 on the other end portion in the axial direction of the outer circumferential surface S1 of the first pin journal PJ1. The side-face blade portion 35 of each second cutting insert 26 is used to cut the side surface S3 of the second journal axial bearing JS2. (Milling, performed by the first milling cutter 13 and the second milling cutter 23) The milling of workpiece 2, performed by the first milling cutter 13 and the second milling cutter 23, will be explained below with reference to the drawings. An example of milling near the first pin tang PJ1 will be explained further below. First, the workpiece 2 is provided in its unmachined state, as shown in Fig. 6. The rough contours of the first pin PJ1, the first counterweight CW1 and the second counterweight CW2 are formed on the workpiece 2. Next, as shown in Fig. 7, the first cutter 13 is moved towards the side of the first pin PJ1, and the side surface S5 of the first counterweight CW1 is cut by the side surface blade part 32 of the first cutting insert 15, and the step S4 of the second pin axial bearing JS2 is cut by the step blade part 33 of the first cutting insert 15. Next, as shown in Fig. 8, the second cutter 23 is moved to the side of the first pin PJ1, the side surface S5 of the second counterweight CW2 is cut by the side surface blade part 32 of the first cutting plate 25, and the step S4 of the third pin axial bearing JS3 is cut by the step blade part 33 of the first cutting plate 25. As shown in Fig. 9, next, while the second milling cutter 23 is positioned on the side of the first pin tang PJ1, one side of the outer circumferential surface S1 of the first pin tang PJ1 is cut by the outer circumferential surface blade part 31 of the first cutting insert 25, the side surface S3 of the second pin axial bearing JS2 is cut by the side surface blade part 35 of the second cutting insert 26, and the groove S2 on one end part in the axial direction of the outer circumferential surface S1 of the first pin tang PJ1 is cut by the groove blade part 34 of the second cutting insert 26. As shown in Fig. 10, the first milling cutter 13 is next moved to the side of the first pin PJ1, and the remainder of the outer circumferential surface S1 of the first pin PJ1 is cut by the outer circumferential blade part 31 of the first cutting insert 15, the side surface S3 of the third pin axial bearing JS3 is cut by the side surface blade part 35 of the second cutting insert 16, and the groove S2 on the other end part in the axial direction of the outer circumferential surface S1 of the first pin PJ1 is cut by the groove blade part 34 of the second cutting insert 16. With the above steps, the milling in the vicinity of the first pin tang PJ1 is completed. (Characteristics) (1) The first milling cutter 13 according to the present embodiment comprises the annular main body part 14, the first cutting insert 15 for cutting an outer circumferential surface S1 of the first pin tang PJ1, and the second cutting insert 16 for cutting a groove S2 on the outer circumferential surface S1 of the first pin tang PJ1. Both the first cutting insert 15 and the second cutting insert 16 are attached to the inner circumferential surface 14S of the main body part 14. The cutting of the outer circumferential surface S1 of the pin journal PJ1 and the forming of the groove S2 can thus be performed on both sides by the first milling cutter 13. Consequently, even when manufacturing the crankshaft 2a with different widths of the pin journal PJ1 or with different widths of pin journal PJ and main journal MJ, milling can be carried out without changing the first milling cutter 13. This improves the milling efficiency, as a cutter change is not necessary when using the first milling cutter 13. (2) The first cutting inserts 15 of the first milling cutter 13 according to the present embodiment each have the side surface blade part 32 for cutting the side surface S5 of the first counterweight CW1. This can improve the work efficiency of milling, since the cutting of the side surface S5 of the first counterweight CW1 can be carried out by the first milling cutter 13. (3) The first cutting inserts 15 of the first milling cutter 13 according to the present embodiment each have the step blade part 33 for cutting the step S4 of the second pin axial bearing JS2 on the side surface S5 of the first counterweight CW1. This improves the work efficiency of milling, as the cutting of stage S4 of the second journal axial bearing JS2 can be carried out by the first milling cutter 13. (4) The second cutting inserts 16 of the first milling cutter 13 according to the present embodiment each have the side surface blade part 35 for cutting the side surface S3 of the third pin axial bearing JS3. This allows the work efficiency of milling to be further improved, since the cutting of the side surface S3 of the third journal axial bearing JS3 can be carried out by the first milling cutter 13. (Other embodiments) The present invention is not limited to the above embodiment, and various changes and modifications can be made without deviating from the core idea of ​​the invention. The above illustration describes a configuration of the first internal blade milling cutter 13 in which the first cutting inserts 15 and the second cutting inserts 16 are attached to the inner circumferential surface 14S of the main body part 14. However, the first cutting inserts 15 and the second cutting inserts 16 can also be attached to the outer circumferential surface 14T of the main body part 14. That is, the milling cutter according to the present invention can be used for both external blade and internal blade milling cutter types. While the first cutting inserts 15 are exposed towards the first side surface 14P and the second cutting inserts 16 are exposed towards the second side surface 14Q of the first milling cutter 13 as shown above, the mounting positions of the first cutting inserts 15 and the second cutting inserts 16 can be reversed. That is, the first cutting inserts 15 can be exposed towards the second side surface 14Q, and the second cutting inserts 16 can be exposed towards the first side surface 14P. In this case, the second milling cutter 23 can have the same configuration as the first milling cutter 13 and can be mounted rotated 180 degrees relative to the first milling cutter 13. While in the above embodiment milling near the first pin tang PJ1 is described as being performed by the first milling cutter 13 and the second milling cutter 23, the milling by the first milling cutter 13 and the second milling cutter 23 can also be performed near one of the pin tangs PJ and near one of the main tangs MJ in addition to the first pin tang PJ1. While in the above embodiment the first milling cutter 13 has the first cutting inserts 15 and the second cutting inserts 16, the first milling cutter 13 can also have the first cutting inserts 15', the second cutting inserts 16, and the third cutting inserts 17, as shown in Fig. 11. The first cutting inserts 15' project further radially than the third cutting inserts 17. The third cutting inserts 17 are arranged on the side opposite the second cutting inserts 16 in the axial direction.The third cutting inserts 17 do not project axially beyond the centerline 14a of the main body part 14. The third cutting inserts 17 each have the side-surface blade part 32 and the step blade part 33, which are formed on the first cutting inserts 15 according to the embodiment described above, and the first cutting inserts 15' have only the outer circumferential blade part 31. This arrangement of the third cutting inserts 17 on the first milling cutter 13 reduces the load on the first cutting inserts 15', thereby increasing the service life of the first milling cutter 13. In the embodiment described above, the milling near the first pin tang PJ1 has been explained with reference to Figures 7-10. However, the milling sequence is not limited to the explanation above. The sequence of steps in Figures 7-10 can be changed, as long as the step shown in Figure 9 is performed after the step shown in Figure 7, and the step shown in Figure 10 is performed after the step shown in Figure 8. For example, the milling can be performed in any of the following sequences: Figure 7 → Figure 9 → Figure 8 → Figure 10, Figure 7 → Figure 8 → Figure 10 → Figure 9, Figure 8 → Figure 7 → Figure 9 → Figure 10, or Figure 8 → Figure 7 → Figure 9 → Figure 10. Reference symbol list: 1 Crankshaft milling machine 2 Crankshaft blank (workpiece) 2a Crankshaft 10 Milling unit 11 First milling unit 12 First adapter 13 First cutter 14 Main body part 14S Inner circumferential surface 14T Outer circumferential surface 15 First cutting insert 16 Second cutting insert 21 Second milling unit 22 Second adapter 23 Second cutter 24 Main body part 25 First cutting insert 26 Second cutting insert S1 Outer circumferential surface of the journal S2 Groove of the outer circumferential surface of the journal S3 Side surface of the journal thrust bearing S4 Step of the journal thrust bearing S5 Side surface of the counterweight AX Axis center MJ Main journal PJ Bolt journal CW Counterweight JS Journal thrust bearing

Claims

Milling cutter (13, 23) for milling a crankshaft blank (2) which has a journal (PJ1) and a counterweight (CW) connected to the journal (PJ1), wherein the milling cutter (13, 23) comprises: an annular main body part (14) centered on a predetermined axis center (AX); a first cutting insert (15, 25) attached to a circumferential surface (14S) of the main body part (14); and a second cutting plate (16, 26) which is attached to the circumferential surface (14S) of the main body part (14), wherein, viewed in a top view of the circumferential surface (14S), the first cutting plate (15, 25) projects beyond a center line of the main body part (14) in an axial direction parallel to the axis center (AX), and, viewed in a top view of the circumferential surface (14S), the second cutting plate (16, 26) is spaced axially from the center line of the main body part (14), wherein the first cutting plate (15,25) comprising a blade part (31) for an outer circumferential surface (S1) used for milling the outer circumferential surface (S1) of the pin (PJ1), and a blade part (32) for a side surface (S5) used for milling a side surface (S5) of the counterweight (CW), wherein the second cutting insert (16, 26) comprises a blade part (34) for a groove (S2) used for milling a groove (S2) on the outer circumferential surface (S1) of the pin (PJ1). Milling cutter (13, 23) according to claim 1, wherein the first cutting plate (15, 25) has a blade part (33) for a step (S4) which is used to form a step (S4) of a pin axial bearing (JS2) which is provided between the pin (PJ1) and the counterweight (CW). Milling cutter (13, 23) according to claim 2, wherein the second cutting plate (16, 26) has a blade part (35) for a side surface (S3) which is used for milling a side surface (S3) of the pin axial bearing (JS3). Milling cutter (13, 23) according to one of claims 1 to 3, wherein a tip end part (16a) of the second cutting insert (16, 26) projects further in a radial direction which is aligned with the axis center (AX) than the first cutting insert (15, 25). Milling cutter (13, 23) according to one of claims 1 to 4, further comprising: a plurality of first cutting inserts (15, 25) comprising the first cutting insert (15, 25), and a plurality of second cutting inserts (16, 26) comprising the second cutting insert (16, 26), wherein the plurality of first cutting inserts (15, 25) and the plurality of second cutting inserts (16, 26) are arranged alternately in the circumferential direction at the axis center (AX). Crankshaft milling cutter, comprising: the first milling cutter (13) according to any one of claims 1 to 5, a first adapter (12) supporting the first milling cutter (13), the second milling cutter (23) according to any one of claims 1 to 5, and a second adapter (22) supporting the second milling cutter (23), wherein the second cutting insert (16, 26) of the first milling cutter (13) faces the second milling cutter (23); and the second cutting insert (16, 26) of the second milling cutter (23) faces the first milling cutter (13). Method for manufacturing a crankshaft (2a) using a milling cutter (13, 23) according to any one of claims 1 to 5, comprising: milling the side surface (S5) of the counterweight (CW) of the crankshaft blank (2) with the blade part (32) for a side surface (S5) of the first cutting insert (15, 25), milling the outer circumferential surface (S1) of the journal (PJ1) of the crankshaft blank (2) with the blade part (32) for the outer circumferential surface (S1) of the first cutting insert (15, 25), and forming the groove (S2) on the outer circumferential surface (S1) of the journal (PJ1) of the crankshaft blank (2) with blade part (34) for the groove (S2).

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