Method for manufacturing a vehicle wheel

Abstract

The present invention relates to a method for manufacturing a vehicle wheel. The method for manufacturing a vehicle wheel (1) includes: forming a cutting surface on the front surface (30) of the vehicle wheel (1), the cutting surface having a contour shape that follows a target contour shape, the target contour shape defining a change in a target position in the axial direction with respect to a position in the radial direction. The target contour shape includes an arc-shaped first rounded portion (61), a linear first flat portion (62), and a concavo-convex portion (63) having a concavo-convex shape in which concave portions and convex portions are alternately provided. The width of the first flat portion (62) in the radial direction is equal to or greater than twice the feed per revolution in lathe turning, but equal to or less than a first predetermined distance.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a vehicle wheel. Background Art

[0002] For vehicle wheels, a technique is known for performing machining on the front surface (hereinafter referred to as the "front surface") in the axial direction after forming, thereby improving the aesthetic characteristics of the front surface (for example, see European Patent Application Publication No. 3225335). In the vehicle wheel described in European Patent Application Publication No. 3225335, turning is performed on the front surface. The turning is performed along a target contour shape that defines a change in the axial target position with respect to the radial position, and the turning is performed at a feed rate at which the radially adjacent cut marks are radially connected to each other. Thus, a cutting surface having a contour shape along the target contour shape is formed on the front surface of the vehicle wheel. Summary of the Invention

[0003] In the vehicle wheel described in European Patent Application Publication No. 3225335, the target contour shape used in turning is composed of concavo-convex portions having a concavo-convex shape, wherein the concave portions and the convex portions are alternately provided over the entire radial region of the front surface from its radially outer end to its radially inner end. Thus, the cutting surface is formed by a concavo-convex surface, wherein the concave portions and the convex portions are alternately provided over the entire radial region of the front surface. Thereby, the aesthetic characteristics of the front surface are improved.

[0004] Generally, in inspections and the like after manufacturing a vehicle wheel, dimensional measurements are performed. At this time, a part of the front surface of the vehicle wheel serves as a reference surface for dimensional measurement. The reference surface for dimensional measurement is required to be a flat surface. In the vehicle wheel described in European Patent Application Publication No. 3225335, the shape of the concavo-convex surface is composed of linear inclined surfaces, and the radial width (distance between the concave portion and the convex portion) on the inclined surface is in the range of 5 mm to 20 mm. Therefore, it is considered that a flat surface required as a reference surface for dimensional measurement can be easily ensured on the concavo-convex surface. However, when the concavo-convex shape is formed into an arc shape or the distance between the concave portion and the convex portion is narrowed, thereby changing the aesthetic characteristics of the front surface, it is difficult to ensure a flat surface required as a reference surface for dimensional measurement on the concavo-convex surface. In addition, considering the aesthetic characteristics, when the concavo-convex surface is also formed at the radially outer end or the radially inner end of the front surface, it is difficult to ensure a flat surface required as a reference surface for dimensional measurement on the front surface of the vehicle wheel.

[0005] The present invention provides a method for manufacturing a vehicle wheel, which can improve the aesthetic characteristics by providing a cutting surface having a concavo-convex shape on the front surface, and can suppress a decrease in the aesthetic characteristics and ensure a reference surface for measuring dimensions.

[0006] One aspect of the present invention provides a method for manufacturing a vehicle wheel. The manufacturing method includes: performing turning on the front surface of the vehicle wheel along a target contour shape at a feed rate at which radially adjacent cut marks are radially connected to each other, to form a cutting surface having a contour shape following the target contour shape on the front surface of the vehicle wheel, the target contour shape defining a change in a target position in the axial direction of the vehicle wheel with respect to a position in the radial direction of the vehicle wheel. The target contour shape includes: a first rounded portion having an arc shape and extending from a radially first side end of the front surface; a first flat portion having a straight shape and connected to a radially second side of the first rounded portion; and a concavo-convex portion connected to a radially second side of the first flat portion and having a concavo-convex shape, wherein concave portions and convex portions are alternately provided. The width of the first flat portion in the radial direction is equal to or greater than twice the feed per revolution in turning (hereinafter referred to as the feed), but equal to or less than a first predetermined distance. The first predetermined distance is the distance between radially adjacent concave portions or the distance between radially adjacent convex portions.

[0007] In the above configuration, the cutting surface formed on the front surface of the vehicle wheel includes a concavo-convex surface formed to correspond to the concavo-convex portion of the target contour shape. Due to this concavo-convex surface, the aesthetic characteristics of the front surface are improved. In addition, the cutting surface formed on the front surface of the vehicle wheel includes a first flat surface formed to correspond to the first flat portion of the target contour shape, and the first flat surface is formed near a radially first side end of the cutting surface. The width of the first flat surface in the radial direction is equal to or greater than twice the feed per revolution (hereinafter simply referred to as the feed) in turning, but equal to or less than the distance between radially adjacent concave portions or the distance between radially adjacent convex portions on the concavo-convex surface. It should be noted that strictly speaking, on the first flat surface and the concavo-convex surface, a "minute concavo-convex shape formed by cut marks" is formed to overlap with the target contour shape, wherein the cut marks each having a shape corresponding to the shape of the cutting edge of the tool (cutting tool) used in turning are arranged at the same distance as the feed in the radial direction.

[0008] First, compared with the uneven surface, it can be considered that the first flat surface has a surface shape that can easily ensure the flat surface required as a reference surface for dimensional measurement. In particular, when the shape of each of the concave and convex portions constituting the uneven portion is an arc shape, it is difficult for this uneven surface to ensure the flat surface required as a reference surface for dimensional measurement. Further, since the width of the first flat surface in the radial direction is equal to or greater than twice the feed amount, two or more convex portions in the "minute uneven shape formed by the cutting marks" exist over the entire circumferential region of the first flat surface in the radial direction. Thus, the first flat surface ensures the flat surface required as a reference surface for dimensional measurement. Further, since the width of the first flat surface is equal to or less than the distance between radially adjacent concave portions or between radially adjacent convex portions on the uneven surface, it is possible to suppress the case where the aesthetic characteristics of the front surface are degraded due to the excessive width of the first flat surface. Thus, by adopting the above configuration, a vehicle wheel can be manufactured that can improve the aesthetic characteristics by providing a cutting surface having an uneven shape on the front surface, and can suppress the degradation of the aesthetic characteristics and ensure a reference surface for measuring dimensions.

[0009] In this manufacturing method, the target contour shape may further include: a second flat portion having a linear shape and connected to the second radial side of the uneven portion; and a second rounded portion having an arc shape and connected to the second radial side of the second flat portion, the second rounded portion extending to the second radial side end of the front surface. The width of the second flat portion in the radial direction may be equal to or greater than twice the feed amount per revolution in lathe turning, but equal to or less than a first predetermined distance.

[0010] In the above configuration, the cutting surface formed on the front surface of the vehicle wheel includes a second flat surface formed to correspond to the second flat portion of the target contour shape, and the second flat surface is formed near the second radial side end of the cutting surface. It should be noted that strictly speaking, similar to the first flat surface, a "minute uneven shape formed by the cutting marks" is also formed on the second flat surface to overlap with the target contour shape. Similar to the first flat surface, the second flat surface ensures the flat surface required as a reference surface for dimensional measurement. Therefore, a reference surface for measuring the dimensions of each component based on the cutting surface can be easily ensured at either end of the cutting surface in the radial direction, whereby the dimensions of each component can be more easily measured.

[0011] In this manufacturing method, at least one of the following conditions i) and ii) may be satisfied: i) the width of the first flat portion in the radial direction is equal to or less than a second predetermined distance, which is the distance between recesses that are radially adjacent to each other and connected to the first flat portion, or the distance between protrusions that are radially adjacent to each other and connected to the first flat portion; and ii) the width of the second flat portion in the radial direction is equal to or less than a third predetermined distance, which is the distance between recesses that are radially adjacent to each other and connected to the second flat portion, or the distance between protrusions that are radially adjacent to each other and connected to the second flat portion.

[0012] In this manufacturing method, each of the recesses and protrusions constituting the concavo-convex portion may have an arc shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the drawings, in which like reference numerals refer to like elements, and in the drawings:

[0014] Figure 1 is a front view of a vehicle wheel according to an embodiment of the present invention;

[0015] Figure 2 is Figure 1 a view of a longitudinal section of the vehicle wheel shown; and

[0016] Figure 3 is a view showing an example of a target contour shape used in lathe turning. DETAILED DESCRIPTION

[0017] A vehicle wheel 1 and a manufacturing method of the vehicle wheel 1 according to an embodiment of the present invention will be described below with reference to the drawings. For ease of description, the axial direction, the radial direction, and the circumferential direction of the vehicle wheel 1 are respectively referred to as the "axial direction", the "radial direction", and the "circumferential direction". In addition, "outer side" and "inner side" in the radial direction and "front side" and "back side" in the axial direction are defined as Figure 2 shown. The axial direction is the direction along the central axis C (see Figure 2 ) of the vehicle wheel 1. When the vehicle wheel 1 is attached to a vehicle, the front side in the axial direction corresponds to the side of the vehicle wheel 1 that is visible from the outside of the vehicle, and the back side in the axial direction corresponds to the side opposite to the side visible from the outside of the vehicle.

[0018] OVERALL CONFIGURATION

[0019] The vehicle wheel 1 is a wheel made of a light alloy. In the present embodiment, the vehicle wheel 1 is made of, for example, aluminum alloy and is manufactured by casting. The vehicle wheel 1 includes a cylindrical rim portion 10 and a disk-shaped disk portion 20 which is provided integrally with an end portion of the rim portion 10 on the front side in the axial direction.

[0020] The rim portion 10 includes, in order from the front side in the axial direction toward the back side in the axial direction, a front side rim flange 11, a front side bead seat 12, a drop groove 13, a back side bead seat 14, and a back side rim flange 15. The bead portion of a tire (not shown) mounted on the vehicle wheel 1 is placed on the front side bead seat 12 and the back side bead seat 14 and is held by the front side rim flange 11 and the back side rim flange 15. The drop groove 13 is a recess into which the bead portion of the tire temporarily enters during the process of attaching the tire to the vehicle wheel 1.

[0021] The disk portion 20 includes a hub attachment portion 21 and a plurality of spoke portions 22. The hub attachment portion is placed coaxially with the central axis C, and the plurality of spoke portions extend radially outward from the hub attachment portion 21 toward the rim portion 10 (front side rim flange 11). The hub attachment portion 21 has a hub hole 23 and a plurality of bolt holes 24. The hub hole penetrates in the axial direction, and the plurality of bolt holes are provided around the hub hole 23. The vehicle wheel 1 is attached to the vehicle such that the hub attachment portion 21 is attached to the hub of the vehicle's axle. A plurality of openings 25 penetrating in the axial direction are provided between the spoke portions 22.

[0022] Front structure

[0023] The front 30 (see Figure 1 ) is the surface of the vehicle wheel 1 on the front side in the axial direction, and this front is the part visible from the outside of the vehicle and is a part that determines the appearance of the vehicle wheel 1. The front 30 is constituted by the surface of the rim portion 10 on the front side in the axial direction and the surface of the disk portion 20 on the front side in the axial direction.

[0024] As Figure 1 shown, the front 30 has a painted surface 40 and a machined surface 50. A colorless or colored transparent paint is applied over the entire surface of the vehicle wheel 1. Considering this factor, the painted surface 40 and the machined surface 50 are visible through the transparent paint film. It should be noted that the transparent paint film is not shown in any of the drawings.

[0025] The painted surface 40 is a surface on which, after molding, a colored paint is applied to the casting surface. In Figure 1 , the painted surface 40 is shown by a dotted pattern. In the vehicle wheel 1, the portion of the front 30 other than the machined surface 50 corresponds to the painted surface 40.

[0026] The machined surface 50 is a metallic luster surface obtained by removing, together with the coating film, a part of the cast surface that has been coated, by turning on a lathe. The machined surface 50 is brighter than the coated surface 40. As observed from Figure 1 , in the vehicle wheel 1, the machined surface 50 is continuously formed in the radial direction from the radially outer end of the front-side rim flange 11 of the rim portion 10, via the spoke portion 22 and the hub attachment portion 21 of the disc portion 20, to the hole edge of the hub hole 23 (that is, over the entire region in the radial direction of the front face 30). The detailed shape of the machined surface 50 will be described later.

[0027] Manufacturing method

[0028] The vehicle wheel 1 is manufactured by successively performing a casting step, a machining step, a coating step, a turning step on a lathe, and a final coating step. In the casting step, the rough shape of the vehicle wheel 1 is formed by casting. In the machining step, for example, the hub hole 23, the bolt holes 24, etc. in the rim portion 10 and the disc portion 20 are formed by cutting or the like. In the coating step, the coated surface 40 is formed by applying a coating to the whole. In the turning step on a lathe, turning is performed on the front face 30 to form the machined surface 50, so that a part of the cast surface after coating (that is, the coated surface 40) together with the coating film is subjected to cutting (which will be described in detail later). In the final coating step, a transparent coating is applied.

[0029] Turning step on a lathe

[0030] The turning step on a lathe will be described in detail below. In the turning step on a lathe, the continuously formed machined surface 50 in the radial direction is formed over the entire region in the radial direction of the front face 30 by turning on a lathe. The turning is performed at a feed rate such that the target contour shape 60 shown in Figure 3 has adjacent cutting marks connected to each other in the radial direction. The target contour shape 60 is a shape that defines the change in the target position in the axial direction with respect to the position in the radial direction of the machined surface 50 in the longitudinal section of the vehicle wheel 1, and corresponds to the contour shape of the machined surface 50.

[0031] More specifically, as shown in Figure 3 , the target contour shape 60 successively has a first rounded portion 61, a first flat portion 62, a concavo-convex portion 63, a second flat portion 64, and a second rounded portion 65 in the radial direction, so as to form the machined surface 50 from the radially outer end a of the front-side rim flange 11 of the rim portion 10, via the spoke portion 22 and the hub attachment portion 21 of the disc portion 20, to the hole edge b of the hub hole 23.

[0032] The first rounded portion 61 is an arc-shaped portion extending from the radially outer end a of the front-side rim flange 11 of the rim portion 10, and is a portion that rounds the front-side end portion of the front-side rim flange 11. The first flat portion 62 is a portion connected to the radially inner side of the first rounded portion 61, and is a portion that extends linearly parallel to the radial direction. The uneven portion 63 is a part connected to the radially inner side of the first flat portion 62, and is a part having an uneven shape in which concave portions c and convex portions d are alternately provided. The shape of each of the concave portion c and the convex portion d constituting the uneven portion 63 is an arc shape. The second flat portion 64 is a portion connected to the radially inner side of the uneven portion 63, and extends linearly parallel to the radial direction. The second rounded portion 65 is an arc-shaped portion connected to the radially inner side of the second flat portion 64 and extending to the hole edge b of the hub hole 23, and is a portion that rounds the front-side end portion of the hub hole 23.

[0033] The first rounded portion 61 and the first flat portion 62 are placed in the radially outer end portion of the target contour shape 60, the second rounded portion 65 and the second flat portion 64 are placed in the radially inner end portion of the target contour shape 60, and the uneven portion 63 constitutes most of the target contour shape 60 except for the two ends in the radial direction of the target contour shape 60. In Figure 3 this case, in the uneven portion 63, three concave portions c are aligned in the radial direction, but in practice, more than three concave portions c are aligned along the shape of the cutting surface 50.

[0034] For example, in turning on a lathe, a circular arc tool with a cutting edge shape having a radius of 2 millimeters (mm) is used, and the feed rate of the tool is uniformly set to 0.4 mm / revolution. Therefore, the feed rate of the tool refers to the speed at which radially adjacent cutting marks made by the tool are connected to each other in the radial direction.

[0035] The radius R3 of the arc shape of the first rounded portion 61 is, for example, 2.5 mm, and the radius R4 of the arc shape of the second rounded portion 65 is, for example, 1.0 mm. In the uneven portion 63, the distance P1 (= the distance P2 between radially adjacent convex portions d) between radially adjacent concave portions c is, for example, 2.2 mm, the radius R1 of the arc shape of the concave portion c is, for example, 3.0 mm, and the radius R2 of the arc shape of the convex portion d is, for example, 1.0 mm. In the present embodiment, the distance P1 (= the distance P2) is uniform and does not depend on the position in the radial direction.

[0036] Set each of the width B1 of the first flat portion 62 and the width B2 of the second flat portion 64 in the radial direction to be equal to or greater than twice the feed per revolution (= 0.4 mm) in lathe turning, but equal to or less than the distance P1 between the radially adjacent recesses c (= the distance P2 between the radially adjacent protrusions d). More precisely, each of the width B1 and the width B2 is equal to or greater than 0.8 mm but equal to or less than 2.2 mm.

[0037] In lathe turning, the vehicle wheel 1 rotates, and the cutting depth of the tool at the radial position of the tool is adjusted so that the contour shape of the cutting surface 50 on the longitudinal section of the vehicle wheel 1 follows the shape of the target contour shape 60. While the tool moves in the radial direction at the feed rate, the front surface 30 is continuously cut from the radially outer end a of the front rim flange 11 of the rim portion 10 toward the hole edge b of the hub hole 23. Thereby, spiral cutting marks (cutting grooves) made by the tool are formed so that the spiral cutting marks are connected to each other in the radial direction, and thereby the cutting surface 50 is formed.

[0038] Then, as Figure 3 shown, the cutting surface 50 is composed of a first rounded surface 51, a first flat surface 52, an uneven surface 53, a second flat surface 54, and a second rounded surface 55 to correspond to the first rounded portion 61, the first flat portion 62, the uneven portion 63, the second flat portion 64, and the second rounded portion 65 of the target contour shape 60. It should be noted that although Figure 3 not shown in, actually, on the cutting surface 50 (= the first rounded surface 51 + the first flat surface 52 + the uneven surface 53 + the second flat surface 54 + the second rounded surface 55), "a minute uneven shape formed by the cutting marks" is formed in a manner overlapping with the target contour shape 60, where the cutting marks (cutting grooves) each having a shape corresponding to the cutting edge shape of the tool are arranged at the same distance as the feed per revolution in the radial direction.

[0039] The uneven surface 53 constitutes most of the cutting surface 50 except for the two end portions in the radial direction of the cutting surface 50. Due to this uneven surface 53, the aesthetic characteristics of the front surface 30 are improved. In addition, the radially outer end portion of the cutting surface 50 includes the first flat surface 52. The width B1 of the first flat surface 52 in the radial direction is equal to or greater than twice the feed per revolution, but equal to or less than the distance between the radially adjacent recesses c or the distance between the radially adjacent protrusions d in the uneven portion 53.

[0040] First, compared with the uneven surface 53, the first flat surface 52 has a surface shape that easily ensures the flat surface required as a reference surface for dimensional measurement. In particular, in the present embodiment, since the shape of each of the concave portion c and the convex portion d constituting the uneven portion 53 is an arc shape, it is difficult for the uneven surface 53 to ensure the flat surface required as a reference surface for dimensional measurement. In addition, the radial width of the first flat surface 52 is equal to or greater than twice the feed per revolution. Therefore, two or more convex portions in the "minute uneven shape formed by the cutting marks" exist in the entire circumferential region of the first flat surface 52 in the radial direction, and the flat surface required as a reference surface for dimensional measurement is ensured in the first flat surface 52. Thus, for example, compared with the uneven surface 53, the first flat surface 52 can be easily used as a reference surface for measuring the dimension A1 in the vehicle wheel 1 (see Figure 2 ). In addition, since the width of the first flat surface 52 is equal to or less than the distance between the radially adjacent concave portions c or the distance between the radially adjacent convex portions d on the uneven surface 53, it is possible to suppress the case where the aesthetic characteristics of the front surface 30 are degraded due to the excessive width of the first flat surface 52.

[0041] Similarly, the radially inner end portion of the cutting surface 50 includes a second flat surface 54. The width B2 of the second flat surface 54 in the radial direction is equal to or greater than twice the feed per revolution, but equal to or less than the distance between the radially adjacent concave portions c or the distance between the radially adjacent convex portions d on the uneven portion 53.

[0042] First, compared with the uneven surface 53, the second flat surface 54 has a surface shape that easily ensures the flat surface required as a reference surface for dimensional measurement. In particular, in the present embodiment, since the shape of each of the concave portion c and the convex portion d constituting the uneven portion 53 is an arc shape, it is difficult for the uneven surface 53 to ensure the flat surface required as a reference surface for dimensional measurement. In addition, the radial width of the second flat surface 54 is equal to or greater than twice the feed per revolution. Therefore, two or more convex portions in the "minute uneven shape formed by the cutting marks" exist in the entire circumferential region of the second flat surface 54 in the radial direction, and the flat surface required as a reference surface for dimensional measurement is ensured in the second flat surface 54. Thus, for example, compared with the uneven surface 53, the second flat surface 54 can be easily used as a reference surface for measuring the dimension A2 in the vehicle wheel 1 (see Figure 2 ). In addition, since the width of the second flat surface 54 is equal to or less than the distance between the radially adjacent concave portions c or the distance between the radially adjacent convex portions d on the uneven surface 53, it is possible to suppress the case where the aesthetic characteristics of the front surface 30 are degraded due to the excessive width of the second flat surface 54.

[0043] It is noted that, compared with the first flat surface 52 (second flat surface 54), the uneven surface 53 connected to the first flat surface 52 (second flat surface 54) is placed closer to the back side in the axial direction. Therefore, the first flat surface 52 (second flat surface 54) serves as a portion protruding toward the front side in the axial direction from the uneven surface 53, making it easy for the first flat surface 52 (second flat surface 54) to be used as a reference surface for dimensional measurement in the vehicle wheel 1.

[0044] Operations and effects

[0045] With the manufacturing method of the vehicle wheel 1 according to the present embodiment, the cutting surface 50 formed on the front surface 30 of the vehicle wheel 1 includes an uneven surface 53 formed to correspond to the uneven portion 63 of the target contour shape 60. Due to this uneven surface 53, the aesthetic characteristics of the front surface 30 are improved. In addition, the radially outer end portion of the cutting surface 50 formed on the front surface 30 of the vehicle wheel 1 includes a first flat surface 52 formed to correspond to the first flat portion 62 of the target contour shape 60, and the radially inner end portion of the cutting surface 50 includes a second flat surface 54 formed to correspond to the second flat portion 64 of the target contour shape 60. The widths B1, B2 of the first and second flat surfaces 52, 54 in the radial direction are equal to or greater than twice the feed per revolution in lathe turning, but equal to or less than the distance between the radially adjacent recesses c or the distance between the radially adjacent protrusions d on the uneven portion 53. Strictly speaking, on the first and second flat surfaces 52, 54 and the uneven surface 53, a "minute uneven shape formed by cutting marks" is formed to overlap with the target contour shape 60, where the cutting marks each having a shape corresponding to the shape of the cutting edge of the tool (cutter) used in lathe turning are arranged in the radial direction at the same distance as the feed.

[0046] First, it can be considered that the first and second flat surfaces 52, 54 have a surface shape that easily ensures the flat surface required as a reference surface for dimensional measurement. In particular, in the present embodiment, since the shape of each of the concave portion c and the convex portion d constituting the uneven portion 53 is an arc shape, it is difficult for the uneven surface 53 to ensure the flat surface required as a reference surface for dimensional measurement. Further, the radial width of the first and second flat surfaces 52, 54 is equal to or greater than twice the feed per revolution. Thus, two or more convex portions in the "minute uneven shape formed by the scratch marks" exist in the entire circumferential region on the first and second flat surfaces 52, 54 in the radial direction. Then, the first and second flat surfaces 52, 54 ensure the flat surface required as a reference surface for dimensional measurement. Further, since the width of the first and second flat surfaces 52, 54 is equal to or less than the distance between the radially adjacent concave portions c or the distance between the radially adjacent convex portions d on the uneven surface 53, it is possible to suppress the following situation, that is, due to the excessive width of the first and second flat surfaces 52, 54, the aesthetic characteristics of the front surface 30 are reduced. Thus, by adopting the manufacturing method of the vehicle wheel 1 according to the present embodiment, it is possible to manufacture the vehicle wheel 1 that can improve the aesthetic characteristics by providing the cutting surface 50 having the uneven shape on the front surface 30, and can suppress the reduction of the aesthetic characteristics and ensure the reference surface for measuring dimensions.

[0047] The present invention is not limited to the above-described exemplary embodiments, and various applications and modifications can be conceived without departing from the object of the present invention. For example, the following modifications can be made by applying the above-described embodiments.

[0048] In the present embodiment, in the uneven portion 63 of the target contour shape 60 (correspondingly, the uneven surface 53 of the cutting surface 50), the distance P1 between the radially adjacent concave portions c ( = the distance P2 between the radially adjacent convex portions d) is uniform and does not depend on the position in the radial direction. However, the distance P1 between the radially adjacent concave portions c ( = the distance P2 between the radially adjacent convex portions d) may change according to the position in the radial direction. In this case, preferably, the width B1 of the first flat portion 62 (correspondingly, the first flat surface 52) in the radial direction is equal to or less than the distance between the radially adjacent concave portions c or the distance between the radially adjacent convex portions d connected to the first flat portion 62 (correspondingly, the first flat surface 52). Similarly, preferably, the width B2 of the second flat portion 64 (correspondingly, the second flat surface 54) in the radial direction is equal to or less than the distance between the radially adjacent concave portions c or the distance between the radially adjacent convex portions d connected to the second flat portion 64 (correspondingly, the second flat surface 54).

[0049] In addition, in the present embodiment, the radially outer end portion of the target contour shape 60 (correspondingly, the cutting surface 50) includes a first flat portion 62 (correspondingly, a first flat surface 52), and the radially inner end portion of the target contour shape 60 (correspondingly, the cutting surface 50) includes a second flat portion 64 (correspondingly, a second flat surface 54). However, either the first flat portion 62 (correspondingly, the first flat surface 52) or the second flat portion 64 (correspondingly, the second flat surface 54) can be omitted.

Claims

1. A manufacturing method of a vehicle wheel (1), characterized by comprising: By performing turning on the front surface (30) of the vehicle wheel (1) along a target profile shape at a feed rate that is radially connected to each other by notches adjacent to each other in the radial direction, a cutting surface having a profile shape following the target profile shape is formed on the front surface (30), and the target profile shape defines a change in the target position in the axial direction of the vehicle wheel with respect to the position in the radial direction of the vehicle wheel, wherein: The target profile shape includes: A first rounded portion (61) having an arc shape and extending from a first radially side end of the front surface (30); A first flat portion (62) having a linear shape and connected to a second radially side of the first rounded portion (61); and An uneven portion (63) connected to a second radially side of the first flat portion (62) and having an uneven shape in which concave portions and convex portions are alternately provided; The width of the first flat portion (62) in the radial direction is equal to or greater than twice the feed per revolution in the turning, but equal to or less than a first predetermined distance; and The first predetermined distance is the distance between concave portions adjacent to each other in the radial direction or the distance between convex portions adjacent to each other in the radial direction.

2. The manufacturing method of the vehicle wheel (1) according to claim 1, characterized in that: The target profile shape further includes: A second flat portion (64) having a linear shape and connected to a second radially side of the uneven portion (63); and A second rounded portion (65) having an arc shape and connected to a second radially side of the second flat portion (64), and the second rounded portion (65) extends to a second radially side end of the front surface (30); and The width of the second flat portion (64) in the radial direction is equal to or greater than twice the feed per revolution in the turning, but equal to or less than the first predetermined distance.

3. The manufacturing method of the vehicle wheel (1) according to claim 2, characterized in that, At least one of the following conditions i) and ii) is satisfied: i) The width of the first flat portion (62) in the radial direction is equal to or less than a second predetermined distance, and the second predetermined distance is the distance between concave portions adjacent to each other in the radial direction and connected to the first flat portion (62) or the distance between convex portions adjacent to each other in the radial direction and connected to the first flat portion (62); And ii) The width of the second flat portion (64) in the radial direction is equal to or less than a third predetermined distance, and the third predetermined distance is the distance between concave portions adjacent to each other in the radial direction and connected to the second flat portion (64) or the distance between convex portions adjacent to each other in the radial direction and connected to the second flat portion (64).

4. The manufacturing method of the vehicle wheel (1) according to any one of claims 1 to 3, characterized in that, Each of the concave portions and the convex portions constituting the uneven portion (63) has an arc shape.

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