WO2015119273A1

WO2015119273A1 - Vehicle wheel and method for producing same

Info

Publication number: WO2015119273A1
Application number: PCT/JP2015/053522
Authority: WO
Inventors: 篠田　誠; 利夫永田; 雅孝内田
Original assignee: 日立金属株式会社
Priority date: 2014-02-07
Filing date: 2015-02-09
Publication date: 2015-08-13
Also published as: JP6455446B2; JPWO2015119273A1

Abstract

The objective of the present invention is to provide: a vehicle wheel having superior corrosion resistance and able to form a coating film having a uniform thickness at an edge at the rear of a window section; and a method for producing the vehicle wheel. The method for producing a vehicle wheel, which is provided with at least a rim section, a hub section, a spoke section, and a window section, includes at least a rounding step containing: a chamfering step for forming a chamfered surface by chamfering the edge between the side surface of the spoke section and the rear surface of the spoke section and positioned at the boundary between the window section and the rear surface; a first rounding step for forming a first curved surface by rounding a first edge that is the edge between the side surface of the spoke section and the chamfered surface; and a second rounding step for forming a second curved surface by rounding a second edge that is the edge between the rear surface of the spoke section and the chamfered surface. The radius (R1) of curvature of the first curved surface is greater than the radius (R2) of curvature of the second curved surface.

Description

車両用ホイール及びその製造方法Vehicle wheel and method of manufacturing the same

　本発明は、四輪自動車の車両用ホイール及びその製造方法に関する。 The present invention relates to a vehicle wheel for a four-wheeled vehicle and a manufacturing method thereof.

　自動車（例えば乗用車）部品である鋳造により製造した軽合金ホイールでは、高質感をもった外観を呈するようにするために、ホイール基体の表面に多層からなる塗装が施される。例えば一般的には、鋳肌の凹凸を隠すために５０～１００μｍほどの厚さで塗られる粉体のポリエステル、アクリル、エポキシ、ウレタン、またはエポキシポリエステル系樹脂などからなるプライマー層、外観の色彩を出すためのポリエステル、またはアクリル系樹脂を主剤とするカラーベース層、カラーベース層の色彩を出すとともに耐候性、および耐蝕性などを高めるためのクリヤー層、からなる三層塗装がある。また、さらに高質感を高めるために、金属の研摩面を連想させる金属調シルバー塗装（メッキ調塗装）を施すものなどもある。 In a light alloy wheel manufactured by casting, which is an automobile (for example, passenger car) part, a multi-layer coating is applied to the surface of the wheel base in order to exhibit a high-quality appearance. For example, in general, a primer layer made of powdered polyester, acrylic, epoxy, urethane, or epoxy polyester-based resin coated with a thickness of about 50 to 100 μm in order to hide the unevenness of the casting surface, the color of the appearance There are three-layer coatings comprising a color base layer mainly composed of polyester or acrylic resin for releasing, and a clear layer for improving the weather resistance, corrosion resistance, and the like while giving the color of the color base layer. In addition, in order to further enhance the high quality, there are some that have a metallic silver coating (plating coating) reminiscent of a polished surface of metal.

　図９は車両用ホイール（以下、単にホイールという場合がある）をディスク面の表側から見た平面図である。ホイール１はタイヤ（図示省略）を装着する円環状のリム部２、その中心にありホイールを車軸に接続するハブ穴３およびホイールを車軸に固定するボルトを接続するボルト穴４を有するハブ部５、及びハブ部５からリム部２へ向かって放射状に延びて前記ハブ部５および前記リム部２をつなぐスポーク部６を主な構成要素とする。そして、前記リム部２、前記ハブ部５、及び前記スポーク部６で囲まれる空間が窓部７である。窓部７とスポーク部６およびハブ部５からなるディスク部８の表側は、ホイール１のデザイン面として意匠性に特に大きな影響を及ぼす。 FIG. 9 is a plan view of a vehicle wheel (hereinafter sometimes simply referred to as a wheel) viewed from the front side of the disk surface. A wheel 1 has an annular rim portion 2 on which a tire (not shown) is mounted, a hub portion 5 having a hub hole 3 at the center for connecting the wheel to the axle and a bolt hole 4 for connecting a bolt for fixing the wheel to the axle. The spoke portion 6 that extends radially from the hub portion 5 toward the rim portion 2 and connects the hub portion 5 and the rim portion 2 is a main component. A space surrounded by the rim part 2, the hub part 5, and the spoke part 6 is a window part 7. The front side of the disk portion 8 including the window portion 7, the spoke portion 6, and the hub portion 5 has a particularly great influence on the design as a design surface of the wheel 1.

　車両用ホイールに塗装を行う場合、ホイール基体を加工することで形成されるエッジ部の防錆対策を検討する必要がある。特に、スポーク部は、ディスク部の裏側にある裏面および窓部の輪郭を形成する側面を有し、旋盤加工によってディスク部の裏側が加工される際に、当該裏面および当該側面も加工される。例えば、この場合、前記スポーク部の裏面と前記窓部との境界に位置する、当該裏面と前記スポーク部の側面との端部は、鋭角もしくは鋭角に近い角度を持つエッジ形状となることがある。プライマーは、粉体塗装されてホイールに塗膜が形成された後、１００～２００℃程度の温度で焼付けられる。この焼付けの時に、プライマーの樹脂が液状となり、その表面張力や応力等により、プライマーが塗装面の中央側に収縮する場合がある。この場合、エッジ形状の端部では、その稜線の両側にプライマーが引っ張られてしまうために、前記端部の表面に十分な厚さの塗膜を形成することが困難なことがある。プライマーの塗膜がエッジ形状の端部において十分な厚さにならないと、当該端部では耐蝕性が不十分になって糸錆が発生しやすくなる。糸錆が発生すると、端部の周囲に錆が広がって外観性が悪化するだけでなく、著しい場合、ホイールの耐久性等の性能も低下することがある。 ¡When painting a vehicle wheel, it is necessary to consider anti-rust measures for the edges formed by processing the wheel base. In particular, the spoke portion has a back surface on the back side of the disk portion and a side surface that forms the outline of the window portion, and when the back side of the disk portion is processed by lathe processing, the back surface and the side surface are also processed. For example, in this case, the end portion of the back surface and the side surface of the spoke portion, which is located at the boundary between the back surface of the spoke portion and the window portion, may have an edge shape having an acute angle or an angle close to an acute angle. . The primer is baked at a temperature of about 100 to 200 ° C. after powder coating and a coating film is formed on the wheel. During this baking, the primer resin becomes liquid, and the primer may shrink toward the center of the painted surface due to surface tension or stress. In this case, at the edge part of the edge shape, the primer is pulled on both sides of the ridge line, so that it may be difficult to form a coating film having a sufficient thickness on the surface of the edge part. If the coating film of the primer does not have a sufficient thickness at the edge of the edge shape, the corrosion resistance is insufficient at the edge, and yarn rust is likely to occur. When yarn rust occurs, not only does the rust spread around the end portion and the appearance is deteriorated, but in the case of remarkable, performance such as durability of the wheel may be lowered.

　このエッジ形状の端部での糸錆発生を防ぐために、例えば特許文献１では、次の（ａ）～（ｆ）の各工程を実行する車両用ホイールの製造方法が開示されている。即ち、（ａ）周方向に間隔をおいて複数の飾り穴を有するディスク部とリム部とを一体に鋳造する工程と、（ｂ）上記ディスク部にハブ穴とボルト穴を明けるとともに、ディスク部裏面を切削する加工工程と、（ｃ）鋳肌面からなる上記飾り穴の内周面と切削面からなる上記ディスク部裏面との境のエッジの面取りを行なう面取り工程と、（ｄ）バレル研磨工程と、（ｅ）上記ディスク部裏面において上記複数の飾り穴が配置された環状の飾り穴形成領域に、少なくともこの飾り穴形成領域の全領域を占めるように配置された円環状のブラシを当て、この円環状のブラシをディスク部の中心軸線を中心として回転することにより、上記飾り穴の内周面とディスク部裏面との境のエッジを研磨するブラシ研磨工程と、（ｆ）塗装工程とを実行する車両用ホイールの製造方法である。この製法により得られた車両用ホイールのエッジはブラシ研磨により良好に処理されて丸められているので、塗膜が良好に付着されアルミ地金が露出しないので、長期使用による錆発生を防止できるとしている。 In order to prevent the occurrence of yarn rust at the edge of the edge shape, for example, Patent Document 1 discloses a method for manufacturing a vehicle wheel that executes the following steps (a) to (f). (A) a step of integrally casting a disc portion having a plurality of decorative holes and a rim portion spaced apart in the circumferential direction; and (b) making a hub hole and a bolt hole in the disc portion, A machining step for cutting the back surface, (c) a chamfering step for chamfering an edge between the inner peripheral surface of the decorative hole made of a casting surface and the back surface of the disk portion made of a cutting surface, and (d) barrel polishing. And (e) applying an annular brush disposed so as to occupy at least the entire region of the decorative hole forming region to the annular decorative hole forming region where the plurality of decorative holes are disposed on the back surface of the disk portion. A brush polishing step for polishing the edge of the border between the inner peripheral surface of the decorative hole and the back surface of the disc portion by rotating the annular brush around the central axis of the disc portion; and (f) a coating step; Run It is a manufacturing method of the vehicle wheel. Since the edge of the vehicle wheel obtained by this manufacturing method is well processed by brush polishing and rounded, the coating film adheres well and the aluminum ingot is not exposed, so it is possible to prevent rust generation due to long-term use Yes.

特許第４５１６５０９号公報Japanese Patent No. 4516509

　しかし、発明者らによる検討の結果、特許文献１記載の車両用ホイールの製造方法によっても、エッジ形状の端部には塗膜が良好に付着されない場合があることが分かった。その理由について、図１０～１４を参照しつつ説明する。 However, as a result of investigations by the inventors, it has been found that the coating film may not be satisfactorily adhered to the edge of the edge shape even by the vehicle wheel manufacturing method described in Patent Document 1. The reason will be described with reference to FIGS.

　図１０は図９に示すホイール１のスポーク部６をホイールの径方向に対して直角に切断したＡ－Ａ断面図である。図１０において上側がディスク面の表側であり、下側がディスク面の裏側である。ここで、特許文献１の加工工程では、スポーク部の外側の側面４１とディスク面裏側のスポーク裏面４２は、切削加工される。切削加工後に、スポーク裏面４２と窓部に臨むスポーク部の外側の側面４１（窓部の内周面）との端部Ｂ（以下、単に端部という場合がある）が形成される。ホイールを鋳造法で形成する場合、スポーク部の外側の側面４１は、鋳造したホイール基体を金型から抜きやすくするため、抜け勾配γを有することがある。この抜け勾配γを有することで、端部Ｂは鋭角となりやすい。なお、スポーク部は軽量化するために、図１０に示すように内部を鋳抜いた構造とする場合もある。 FIG. 10 is a cross-sectional view taken along the line AA in which the spoke portion 6 of the wheel 1 shown in FIG. 9 is cut at right angles to the radial direction of the wheel. In FIG. 10, the upper side is the front side of the disk surface, and the lower side is the back side of the disk surface. Here, in the processing step of Patent Document 1, the outer side surface 41 of the spoke part and the spoke rear surface 42 on the disk surface back side are cut. After the cutting process, an end B (hereinafter sometimes simply referred to as an end) between the spoke back surface 42 and the outer side surface 41 (the inner peripheral surface of the window) of the spoke facing the window is formed. When the wheel is formed by a casting method, the outer side surface 41 of the spoke portion may have a draft γ to facilitate removal of the cast wheel base from the mold. By having this draft gradient γ, the end B tends to have an acute angle. In addition, in order to reduce the weight of the spoke portion, there may be a structure in which the inside is cast as shown in FIG.

　このホイールに塗装を施すと、端部Ｂには十分な厚さの塗膜が形成されないため、加工工程後、塗装工程の前に端部Ｂの面取り加工（面取り工程）を行う。面取り加工ではグラインダ等により端部Ｂの先端を除去する。図１１は従来の車両用ホイールの製造方法におけるスポーク裏面４２と窓部に臨むスポーク部の外側の側面４１との端部Ｂを面取りする面取り加工方法を示す図である。図１１に示すように、端部Ｂには、面取り加工により形成された面取り面４０とスポーク部の外側の側面４１とで形成された端部４３（以下、第１端部と言う場合がある。）と面取り面４０とスポーク部の裏面４２とで形成された端部４４（以下、第２端部と言う場合がある。）の２つの端部が新たに形成される。 When this wheel is painted, a coating with a sufficient thickness is not formed on the end B. Therefore, after the processing step, the end B is chamfered (chamfering step) before the coating step. In the chamfering process, the tip of the end B is removed by a grinder or the like. FIG. 11 is a diagram showing a chamfering method for chamfering an end portion B between a spoke back surface 42 and an outer side surface 41 of a spoke portion facing a window portion in a conventional vehicle wheel manufacturing method. As shown in FIG. 11, the end portion B may be referred to as an end portion 43 (hereinafter referred to as a first end portion) formed by a chamfered surface 40 formed by chamfering and a side surface 41 outside the spoke portion. .) And the chamfered surface 40 and the back surface 42 of the spoke portion, two end portions 44 (hereinafter sometimes referred to as second end portions) are newly formed.

　図１２は面取り加工後の端部Ｂを丸める丸め加工方法を示す図である。加工手段はブラシ研磨法である。砥粒を担持した多数の繊維の集合体からなるブラシ９をディスク面の裏側に配置し、ブラシ９の自由端１０を窓部７内に入れてブラシをスポーク裏面に沿う方向に移動させる。これにより、ブラシ９は第１端部４３と第２端部４４を研磨し丸める。この場合、第２端部４４がより多く研磨される。 FIG. 12 is a diagram showing a rounding method for rounding the end B after the chamfering. The processing means is a brush polishing method. A brush 9 made of an aggregate of a large number of fibers carrying abrasive grains is disposed on the back side of the disk surface, and the free end 10 of the brush 9 is placed in the window 7 to move the brush in a direction along the back surface of the spoke. Accordingly, the brush 9 polishes and rounds the first end portion 43 and the second end portion 44. In this case, the second end portion 44 is more polished.

　図１３は丸め加工後の端部Ｂの断面図である。図１２で説明したブラシ研磨法により、端部Ｂに丸め加工を実施すると、縁部Ｂは図１３で示す円弧形状になる。第２端部がより多く研磨された結果、第２端部４４が丸められた第２円弧面４６の曲率半径Ｒ２は、第１端部４３が丸められた第１円弧面４５の曲率半径Ｒ１よりも大きくなる。 FIG. 13 is a cross-sectional view of the end B after rounding. When the end portion B is rounded by the brush polishing method described in FIG. 12, the edge portion B has an arc shape shown in FIG. As a result of more polishing of the second end portion, the radius of curvature R2 of the second arc surface 46 with the second end portion 44 rounded is equal to the radius of curvature R1 of the first arc surface 45 with the first end portion 43 rounded. Bigger than.

　図１４は丸め加工後に塗装した端部Ｂの断面図である。曲率半径が大きい第２円弧面４６には十分な厚さの塗膜を形成することができるが、曲率半径が小さい第１円弧面４５の塗膜は薄い。第１円弧面では、耐蝕性が不十分になって糸錆が発生しやすくなり、糸錆が発生して周囲に広がっていくと外観性が悪化し、著しい場合、耐久性も低下することがある。プライマーを多数回塗膜することにより、塗膜を厚くすることができるが、生産工数の増大を招くため好ましくない。丸め加工後の第２円弧面の曲率半径Ｒ２が大きくなり、第１円弧面の曲率半径Ｒ１が小さくなるのは、端部Ｂの面取り工程で形成される二つの端部である第１端部と第２端部のそれぞれの角度（内角）が、ほぼ同じになることが原因である場合がある。 FIG. 14 is a cross-sectional view of the end B painted after rounding. A coating film having a sufficient thickness can be formed on the second arc surface 46 having a large curvature radius, but the coating film on the first arc surface 45 having a small curvature radius is thin. On the first circular arc surface, the corrosion resistance becomes insufficient and yarn rust is likely to occur. When the yarn rust is generated and spreads around, the appearance is deteriorated, and if it is remarkable, the durability may be lowered. is there. By coating the primer many times, the coating can be thickened, but this is not preferable because it increases the number of production steps. The radius of curvature R2 of the second arc surface after rounding increases, and the radius of curvature R1 of the first arc surface decreases, the first end being two ends formed in the chamfering process of the end B And the respective angles (inner angles) of the second end portion may be substantially the same.

　よって本発明は、スポーク部の裏面と窓部との境界に位置する、当該裏面とスポーク部の側面との端部に、均一な厚さの塗膜を形成することができ、耐蝕性に優れた車両用ホイール及びその製造方法を提供することを目的とする。 Therefore, the present invention can form a coating film with a uniform thickness on the edge between the back surface of the spoke part and the side surface of the spoke part, located at the boundary between the back surface and the window part, and has excellent corrosion resistance. Another object is to provide a vehicle wheel and a method of manufacturing the same.

　上記課題を解決するための本願第１の発明に係る車両用ホイールの製造方法は、タイヤを装着する円環形状のリム部、車両用ホイールを車軸に接続するハブ穴を有するハブ部、前記ハブ部から前記リム部に向かって放射状に延びて当該ハブ部および当該リム部をつなぐスポーク部、並びに前記リム部、前記ハブ部および前記スポーク部で囲まれた空間である窓部を少なくとも備える車両用ホイールの製造方法であって、前記スポーク部の裏面と前記窓部との境界に位置する当該裏面と前記スポーク部の側面との端部を面取りして面取り面を形成する面取り工程と、前記面取り面と前記スポーク部の側面との端部である第１端部を丸めて第１円弧面を形成する第１丸め工程と、前記面取り面と前記スポーク部の裏面との端部である第２端部を丸めて第２円弧面を形成する第２丸め工程を含む丸め工程を少なくとも含み、前記第１円弧面の曲率半径Ｒ１は、前記第２円弧面の曲率半径Ｒ２よりも大きい、車両用ホイールの製造方法、である。 A vehicle wheel manufacturing method according to a first aspect of the present invention for solving the above-described problems includes an annular rim portion for mounting a tire, a hub portion having a hub hole for connecting the vehicle wheel to an axle, and the hub. The vehicle includes at least a spoke portion that extends radially from a portion toward the rim portion and connects the hub portion and the rim portion, and a window portion that is a space surrounded by the rim portion, the hub portion, and the spoke portion. A chamfering method for forming a chamfer by chamfering an end portion of the back surface and the side surface of the spoke portion, which is located at a boundary between the back surface of the spoke portion and the window portion, in the wheel manufacturing method; A first rounding step of rounding a first end that is an end of a surface and a side of the spoke portion to form a first arc surface; and a second rounding end of the chamfered surface and the back of the spoke portion End At least a rounding step including a second rounding step for forming a second arcuate surface, wherein the radius of curvature R1 of the first arcuate surface is larger than the radius of curvature R2 of the second arcuate surface. Method.

　本願第１の発明においては、前記第１端部の内角αは、前記第２端部の内角βよりも大きくなるよう前記面取り工程で加工することができる。丸め工程の前に、面取り工程において、前記第１端部の内角αが前記第２端部の内角βよりも大きくなるように面取りしておくことにより、丸め工程で前記曲率半径Ｒ１を前記曲率半径Ｒ２よりも大きくすることが容易となる。 In the first invention of the present application, the chamfering step can process the inner angle α of the first end portion to be larger than the inner angle β of the second end portion. Before the rounding step, in the chamfering step, the inner radius α of the first end portion is chamfered so as to be larger than the inner angle β of the second end portion. It becomes easy to make it larger than the radius R2.

　本願第１の発明においては、前記丸め工程は、前記ハブ部、前記スポーク部および前記窓部からなるディスク部の裏面側にブラシを配置するブラシ配置工程と、前記ブラシと前記ディスク部の裏面とを相対移動させて、当該ブラシで前記第１端部および前記第２端部を摺擦して前記第１円弧面および前記第２円弧面を形成する摺擦工程を少なくとも含み、前記摺擦工程により、前記第１円弧面の曲率半径Ｒ１を前記第２円弧面の曲率半径Ｒ２よりも大きくすることができる。ブラシにより摺擦することで、曲率半径Ｒ１を曲率半径Ｒ２よりも大きくすることが容易となる。 In the first invention of the present application, the rounding step includes a brush arranging step of arranging a brush on the back surface side of the disk portion including the hub portion, the spoke portion, and the window portion, and the brush and the back surface of the disk portion. At least a rubbing step of sliding the first end and the second end with the brush to form the first arc surface and the second arc surface, the rubbing step Thus, the radius of curvature R1 of the first arc surface can be made larger than the radius of curvature R2 of the second arc surface. By rubbing with a brush, it becomes easy to make the curvature radius R1 larger than the curvature radius R2.

　本願第１の発明においては、前記ブラシは回転軸を有するロール型ブラシであり、前記摺擦工程は、当該ロール型ブラシの回転軸が前記ディスク部の裏面と平行にして回転すると共に、前記ディスク部の裏面に対して同心状に相対回転して摺擦する工程とすることができる。ロール型ブラシを使用することで、曲率半径Ｒ１を曲率半径Ｒ２よりも大きくすることが容易となる。 In the first invention of the present application, the brush is a roll-type brush having a rotating shaft, and the rubbing step rotates in such a manner that the rotating shaft of the roll-type brush rotates in parallel with the back surface of the disk portion. It can be set as the process of rotating relatively concentrically with respect to the back surface of a part, and rubbing. By using a roll type brush, it becomes easy to make the curvature radius R1 larger than the curvature radius R2.

　上記課題を解決するための本願第２の発明に係る車両用ホイールは、タイヤを装着する円環形状のリム部、車両用ホイールを車軸に接続するハブ穴を有するハブ部、前記ハブ部から前記リム部に向かって放射状に延びて当該ハブ部および当該リム部をつなぐスポーク部、並びに前記リム部、前記ハブ部および前記スポーク部で囲まれた空間である窓部を少なくとも備える車両用ホイールであって、前記スポーク部の裏面と前記窓部との境界に位置する当該裏面と前記スポーク部の側面との端部は、前記スポーク部の側面と接する円弧面である第１円弧面と、前記スポーク部の裏面と接する円弧面である第２円弧面を備え、前記第１円弧面の曲率半径Ｒ１は、前記第２円弧面の曲率半径Ｒ２よりも大きい、車両用ホイール、である。 A vehicle wheel according to a second invention of the present application for solving the above-described problems is provided with an annular rim portion for mounting a tire, a hub portion having a hub hole for connecting the vehicle wheel to an axle, and the hub portion. A vehicle wheel comprising at least a spoke portion that extends radially toward the rim portion and connects the hub portion and the rim portion, and a window portion that is a space surrounded by the rim portion, the hub portion, and the spoke portion. An end of the back surface and the side surface of the spoke portion located at the boundary between the back surface of the spoke portion and the window portion is a first arc surface that is an arc surface in contact with the side surface of the spoke portion, and the spoke The vehicle wheel includes a second arc surface that is an arc surface in contact with the back surface of the portion, and a radius of curvature R1 of the first arc surface is larger than a radius of curvature R2 of the second arc surface.

　本願第２の発明においては、前記第２円弧面の曲率半径Ｒ２は、２００μｍ以上６００μｍ以下とすることができる。曲率半径Ｒ２がこの範囲内であることにより、第２円弧面に十分な膜厚の塗膜を付すことができることで、防食性に優れることとなる。曲率半径Ｒ２が２００μｍよりも小さい場合、第２円弧面へ塗装してもさびを防ぐために十分な乾燥塗膜を得ることができず、防食性が劣ることとなる。また、曲率半径Ｒ２が６００μｍよりも大きいと、丸め工程に、より長い加工時間が必要となり、生産性が低下することやブラシの消耗がより速く進展すること等の不都合が生じる。 In the second invention of the present application, the radius of curvature R2 of the second arcuate surface can be 200 μm or more and 600 μm or less. When the curvature radius R2 is within this range, a coating film having a sufficient film thickness can be applied to the second arc surface, and thus the corrosion resistance is excellent. When the curvature radius R2 is smaller than 200 μm, it is not possible to obtain a sufficient dry coating film to prevent rust even if the second arc surface is coated, and the corrosion resistance is inferior. On the other hand, if the radius of curvature R2 is larger than 600 μm, a longer processing time is required for the rounding process, which causes inconveniences such as reduced productivity and faster brush consumption.

　本願第１の発明に係る車両用ホイールの製造方法は、スポーク部の裏面と窓部との境界に位置する当該裏面とスポーク部の側面との端部に均一な厚さの塗膜を形成することができる。
　本願第２の発明に係る車両用ホイールは、耐蝕性に優れた車両用ホイールを提供することができる。 In the vehicle wheel manufacturing method according to the first aspect of the present invention, a coating film having a uniform thickness is formed at the end of the back surface and the side surface of the spoke portion located at the boundary between the back surface of the spoke portion and the window portion. be able to.
The vehicle wheel according to the second invention of the present application can provide a vehicle wheel having excellent corrosion resistance.

鋳造法による車両用ホイールの製造工程を示すフロー図。The flowchart which shows the manufacturing process of the wheel for vehicles by a casting method. 面取り工程後の端部Ｂの断面図。Sectional drawing of the edge part B after a chamfering process. ブラシが第１端部に当たる瞬間の状態を示す図。The figure which shows the state of the moment when a brush hits the 1st edge part. 図３に示す状態からブラシが少し進んだ状態を示す図。The figure which shows the state which the brush advanced a little from the state shown in FIG. 図４に示す状態からブラシが更に進んだ状態を示す図。The figure which shows the state which the brush further advanced from the state shown in FIG. 丸め工程後の端部Ｂの断面図。Sectional drawing of the edge part B after a rounding process. 本発明に係る車両用ホイールの製造方法を実施後、塗装したホイールの端部Ｂの断面図。Sectional drawing of the edge part B of the painted wheel after implementing the manufacturing method of the vehicle wheel which concerns on this invention. 局所的な錆の模式図。Schematic diagram of local rust. 車両ホイールをディスク面の表側から見た平面図である。It is the top view which looked at the vehicle wheel from the front side of the disk surface. 図８に示すホイール１のスポーク部６をホイールの径方向に対して直角に切断したＡ－Ａ断面図である。FIG. 9 is a cross-sectional view taken along the line AA in which the spoke portion 6 of the wheel 1 shown in FIG. 8 is cut at right angles to the radial direction of the wheel. 従来の車両用ホイールの製造方法におけるスポーク裏面４２と窓部に臨むスポーク部の外側の側面４１との端部Ｂを面取りする面取り加工方法を示す図である。It is a figure which shows the chamfering processing method which chamfers the edge part B of the spoke back surface 42 and the outer side surface 41 of the spoke part which faces a window part in the manufacturing method of the conventional vehicle wheel. 面取り加工後の端部Ｂを丸める丸め加工方法を示す図である。It is a figure which shows the rounding method which rounds the edge part B after a chamfering process. 丸め加工後の端部Ｂの断面図である。It is sectional drawing of the edge part B after a rounding process. 丸め加工後に塗装した端部Ｂの断面図である。It is sectional drawing of the edge part B painted after rounding. 塗装後の端部Ｂの断面図である。It is sectional drawing of the edge part B after coating.

　本発明について、その具体的な実施形態に基づき図面を参照しつつ説明する。なお、本発明は、以下説明する実施例に限定されず、また、発明の作用効果を奏する限り、同一性の範囲内において適宜変形して実施することができる。 The present invention will be described based on specific embodiments with reference to the drawings. In addition, this invention is not limited to the Example demonstrated below, In addition, as long as there exists an effect of this invention, it can deform | transform suitably within the range of identity.

　本願第１の発明に係る車両用ホイールの製造方法は、タイヤを装着する円環形状のリム部、車両用ホイールを車軸に接続するハブ穴を有するハブ部、前記ハブ部から前記リム部に向かって放射状に延びて当該ハブ部および当該リム部をつなぐスポーク部、並びに前記リム部、前記ハブ部および前記スポーク部で囲まれた空間である窓部を少なくとも備える車両用ホイールの製造方法であって、前記スポーク部の裏面と前記窓部との境界に位置する当該裏面と前記スポーク部の側面との端部を面取りして面取り面を形成する面取り工程と、前記面取り面と前記スポーク部の側面との端部である第１端部を丸めて第１円弧面を形成する第１丸め工程と、前記面取り面と前記スポーク部の裏面との端部である第２端部を丸めて第２円弧面を形成する第２丸め工程を含む丸め工程を少なくとも含み、前記第１円弧面の曲率半径Ｒ１は、前記第２円弧面の曲率半径Ｒ２よりも大きい、という構成を採用することにより以下の効果を奏する。 According to a first aspect of the present invention, there is provided a vehicle wheel manufacturing method comprising: an annular rim portion for mounting a tire; a hub portion having a hub hole for connecting the vehicle wheel to an axle; and the hub portion toward the rim portion. A spoke portion that extends radially and connects the hub portion and the rim portion, and a vehicle wheel manufacturing method including at least a window portion that is a space surrounded by the rim portion, the hub portion, and the spoke portion. A chamfering step of chamfering an end of the back surface and the side surface of the spoke portion located at the boundary between the back surface of the spoke portion and the window portion to form a chamfered surface; and the chamfered surface and the side surface of the spoke portion. A first rounding step of rounding the first end that is the end of the first round to form a first arc surface, and rounding the second end that is the end of the chamfered surface and the back surface of the spoke portion. Form a circular arc surface Wherein at least the step rounding comprises a second rounding step, the first arcuate surface the radius of curvature R1 of the following effects by adopting a configuration in larger, than the radius of curvature R2 of the second arc surface.

　すなわち、従来のブラシ研磨法により、スポーク部の裏面と窓部との境界に位置する当該裏面とスポーク部の側面との端部に丸め加工を実施すると、面取り面とスポーク部の側面との端部である第１端部より面取り面とスポーク部の裏面との端部である第２端部の方がより多く研磨されるため、前記第２端部が十分な耐蝕性を有する厚さの塗膜の形成が可能な程度に丸められて円弧面となったときの、前記第１端部を丸める際の研磨量は少ない。しかしながら、第１端部の内角αは、第２端部の内角βより大きくすることにより、第２端部を丸める際の研磨量が少なくても、第１円弧面の曲率半径Ｒ１を第２円弧面の曲率半径Ｒ２よりも大きくすることができる。これにより、本願第１の発明に係る車両用ホイールの製造方法は、スポーク部の裏面と窓部との境界に位置する当該裏面とスポーク部の側面との端部に均一な厚さの塗膜を形成することができる。 That is, when rounding is performed on the end of the back surface and the side surface of the spoke portion located at the boundary between the back surface of the spoke portion and the window portion by a conventional brush polishing method, the end of the chamfered surface and the side surface of the spoke portion is Since the second end portion, which is the end portion between the chamfered surface and the back surface of the spoke portion, is polished more than the first end portion that is the portion, the second end portion has a thickness with sufficient corrosion resistance. When the first end portion is rounded to a circular arc surface that is rounded to the extent that a coating film can be formed, the amount of polishing is small. However, by setting the inner angle α of the first end portion to be larger than the inner angle β of the second end portion, the radius of curvature R1 of the first arc surface is set to the second even if the amount of polishing when the second end portion is rounded is small. It can be larger than the radius of curvature R2 of the arc surface. As a result, the vehicle wheel manufacturing method according to the first aspect of the present invention provides a coating film having a uniform thickness at the end of the back surface and the side surface of the spoke portion located at the boundary between the back surface of the spoke portion and the window portion. Can be formed.

　本願第２の発明に係る車両用ホイールは、タイヤを装着する円環形状のリム部、車両用ホイールを車軸に接続するハブ穴を有するハブ部、前記ハブ部から前記リム部に向かって放射状に延びて当該ハブ部および当該リム部をつなぐスポーク部、並びに前記リム部、前記ハブ部および前記スポーク部で囲まれた空間である窓部を少なくとも備える車両用ホイールであって、前記スポーク部の裏面と前記窓部との境界に位置する当該裏面と前記スポーク部の側面との端部は、前記スポーク部の側面と接する円弧面である第１円弧面と、前記スポーク部の裏面と接する円弧面である第２円弧面を備え、前記第１円弧面の曲率半径Ｒ１は、前記第２円弧面の曲率半径Ｒ２よりも大きい、という構成を採用することにより、以下の効果を奏する。 A vehicle wheel according to a second invention of the present application includes an annular rim portion for mounting a tire, a hub portion having a hub hole for connecting the vehicle wheel to an axle, and a radial direction from the hub portion toward the rim portion. A vehicle wheel comprising at least a spoke portion that extends and connects the hub portion and the rim portion, and a window portion that is a space surrounded by the rim portion, the hub portion, and the spoke portion, the back surface of the spoke portion The end of the back surface and the side surface of the spoke portion located at the boundary between the first and second window portions is a first arc surface that is an arc surface in contact with the side surface of the spoke portion, and an arc surface in contact with the rear surface of the spoke portion. By adopting a configuration in which the second arc surface is provided and the radius of curvature R1 of the first arc surface is larger than the radius of curvature R2 of the second arc surface, the following effects can be obtained.

　すなわち、本願第２の発明に係る車両用ホイールは、スポーク部の裏面と窓部との境界に位置する、当該裏面とスポーク部の側面との端部に均一な厚さの塗膜を形成することが可能となり、当該端部において糸錆の発生し難い耐蝕性に優れた車両用ホイールを提供することができる。 That is, the vehicle wheel according to the second invention of the present application forms a coating film having a uniform thickness at the end of the back surface and the side surface of the spoke portion, which is located at the boundary between the back surface of the spoke portion and the window portion. Therefore, it is possible to provide a vehicle wheel having excellent corrosion resistance in which yarn rust hardly occurs at the end portion.

　図１により、一例として、鋳造法による車両用ホイールの製造工程を説明する。本発明は、この製造工程に限定されるものではない。車両用ホイールは、基体形成工程１０１、熱処理工程１０２、加工工程１０３、面取り工程１０４、丸め工程１０５、塗装前処理工程１０６、および塗装工程１０７を経て、製造される。 FIG. 1 illustrates, as an example, a process for manufacturing a vehicle wheel by a casting method. The present invention is not limited to this manufacturing process. The vehicle wheel is manufactured through a substrate forming step 101, a heat treatment step 102, a processing step 103, a chamfering step 104, a rounding step 105, a pre-painting treatment step 106, and a painting step 107.

　基体形成工程１０１では、金属の溶湯を金型内に注湯し、冷却後に金型から取り出すことにより、リム部、ハブ部、スポーク部、および窓部を少なくとも備える車両用ホイールの基体を得る。例えば、アルミニウム合金製の車両用ホイールを鋳造法で作製する場合、基体形成工程ではＡＣ４ＣＨ等の規格に適合するように成分調整したアルミニウム合金の溶湯を低圧鋳造法やグラビティー鋳造法等により金型内に注湯し、冷却後に金型から取り出すことにより車両用ホイールの基体を得る。基体は図９に示すようにリム部２、ハブ部５、スポーク部６を主な構成要素とし、デザイン面にリム部２、ハブ部５、及びスポーク部６で囲まれる空間である窓部７を備える。図１０に示すように、車両用ホイールの基体のスポーク部の外側の側面４１は、ディスク面の表側から裏面にかけて傾斜があり、その傾斜角度は０°を超え９０°未満である。この傾斜は抜け勾配γとも呼ばれ、鋳造法において基体を鋳型から容易に取り外しやすくする目的で、この勾配が付けられている。この傾斜角度が０°以下の場合は、ホイールの意匠性が損なわれ、９０°以上では、スポーク部６を形成することができない。基体形成工程は、基体のスポーク部の裏面加工を行う場合には、当該裏面加工を含まれる。図２で示すように、スポーク裏面４２と窓部に臨むスポーク部の外側の側面４１（窓部の内周面）との端部Ｂのエッジの角度θは、意匠性及び製造の容易さから０°を超え９０°未満とすることができる。 In the base body forming step 101, a molten metal is poured into a mold, and after cooling, is taken out of the mold to obtain a vehicle wheel base body including at least a rim portion, a hub portion, a spoke portion, and a window portion. For example, when a vehicle wheel made of an aluminum alloy is manufactured by a casting method, a molten aluminum alloy whose components are adjusted so as to conform to a standard such as AC4CH in a base forming process is formed in a mold by a low pressure casting method or a gravity casting method. The vehicle body of the vehicle wheel is obtained by pouring into the mold and removing it from the mold after cooling. As shown in FIG. 9, the base body includes a rim portion 2, a hub portion 5, and a spoke portion 6 as main components, and a window portion 7 that is a space surrounded by the rim portion 2, the hub portion 5, and the spoke portion 6 on the design surface. Is provided. As shown in FIG. 10, the side surface 41 on the outer side of the spoke portion of the base of the vehicle wheel has an inclination from the front side to the back side of the disk surface, and the inclination angle is more than 0 ° and less than 90 °. This inclination is also called a draft gradient γ, and this gradient is given for the purpose of easily removing the substrate from the mold in the casting method. When this inclination angle is 0 ° or less, the design of the wheel is impaired, and when it is 90 ° or more, the spoke portion 6 cannot be formed. The substrate forming step includes the back surface processing when the back surface processing of the spoke portion of the substrate is performed. As shown in FIG. 2, the angle θ of the edge B between the spoke back surface 42 and the outer side surface 41 (inner peripheral surface of the window portion) of the spoke portion facing the window portion is determined from design and ease of manufacture. It can be greater than 0 ° and less than 90 °.

　次いで、前記基体を構成するアルミニウム合金の組織を調整して所期の機械的特性を得るために、当該基体に熱処理をする熱処理工程１０２を必要に応じて行う。次に、前記スポーク部の裏面と前記窓部との境界に位置する当該裏面と前記スポーク部の側面との端部以外の箇所の面取りや、バリ取り等の加工を行う加工工程１０３を必要に応じて行う。面取り工程１０４および丸め工程１０５については、上記したとおりであるが、詳細は後に説明する。次いで、前記基体への塗装前の処理として、前記基体の表面の脱脂や化成処理等を行う塗装前処理工程１０６を、必要に応じて行う。 Next, in order to adjust the structure of the aluminum alloy constituting the substrate and obtain the desired mechanical characteristics, a heat treatment step 102 for heat-treating the substrate is performed as necessary. Next, it is necessary to have a processing step 103 for chamfering or deburring other than the end of the back surface and the side surface of the spoke portion located at the boundary between the back surface of the spoke portion and the window portion. Do it accordingly. The chamfering step 104 and the rounding step 105 are as described above, but details will be described later. Next, as a pre-coating process on the substrate, a pre-coating process 106 for performing degreasing, chemical conversion or the like on the surface of the substrate is performed as necessary.

　最後に、塗装工程１０７にて前記基体に塗装を行い、車両用ホイールが完成する。塗装工程では、例えば、プライマー塗料をディスク部の表側と裏側およびスポーク部の側面に吹付けてプライマー層を形成し、そのプライマー層の上にカラーベース塗料を吹付け、該カラーベース塗料を焼付けてカラーベース層とし、該カラーベース層の上にクリヤー塗料を吹付け、その後、前記クリヤー塗料を焼付ける塗装方法を採用することができる。プライマー塗料は、ポリエステル系、アクリル系、エポキシ系、ウレタン系等の樹脂を使用できる。プライマー層の乾燥膜厚は、ホイールの鋳肌の凹凸を隠す必要がある場合、４０μｍ～２００μｍ程度の厚さが好ましい。塗膜装置としては、静電塗装装置を用いることができる。カラーベース塗料として、例えばアクリル、ポリエステル、エポキシ樹脂塗料等からなり、溶剤を含むものや水性の塗料を使用できる。ホイールへの塗装としては、エアスプレーや静電塗装などで吹付ける方法が挙げられる。カラーベース層の乾燥膜厚は、１０μｍ～４０μｍとすることが好ましい。クリヤー塗料は、透明性、光沢、耐候性等に優れたアクリル溶剤塗料等を用いることができる。クリヤー層の乾燥膜厚は、１０μｍ～４０μｍとすることができる。図７は、本発明に係る車両用ホイールの製造方法を実施し、クリヤー塗装後のホイールの端部Ｂの断面図である。本発明に係る車両用ホイールの製造方法によれば、ほぼ一様な厚さの塗膜を形成することができる。 Finally, the vehicle body is painted in the painting process 107 to complete the vehicle wheel. In the painting process, for example, a primer paint is sprayed on the front and back sides of the disk portion and the side surfaces of the spoke portions to form a primer layer, and a color base paint is sprayed on the primer layer, and the color base paint is baked to form a color base layer. And a coating method in which a clear paint is sprayed on the color base layer and then the clear paint is baked. As the primer paint, resins such as polyester, acrylic, epoxy, and urethane can be used. The dry thickness of the primer layer is preferably about 40 μm to 200 μm when it is necessary to hide the unevenness of the cast surface of the wheel. An electrostatic coating apparatus can be used as the coating apparatus. As the color base paint, for example, an acrylic, polyester, epoxy resin paint or the like can be used. Examples of the coating on the wheel include a method of spraying with air spray or electrostatic coating. The dry thickness of the color base layer is preferably 10 μm to 40 μm. As the clear paint, an acrylic solvent paint excellent in transparency, gloss, weather resistance and the like can be used. The dry film thickness of the clear layer can be 10 μm to 40 μm. FIG. 7 is a cross-sectional view of the end B of the wheel after the clear coating is carried out in the vehicle wheel manufacturing method according to the present invention. According to the vehicle wheel manufacturing method of the present invention, a coating film having a substantially uniform thickness can be formed.

　本発明に係る車両用ホイールの製造方法のうち、面取り工程および丸め工程について、図２～７を参照しつつ説明する。 The chamfering step and the rounding step in the vehicle wheel manufacturing method according to the present invention will be described with reference to FIGS.

［面取り工程］
　図２は面取り工程後の端部Ｂの断面を示す。面取り面４０とスポーク部の外側の側面４１との端部である第１端部４３の内角をα（°）、前記面取り面４０と前記スポーク部の裏面４２との端部である第２端部４４の内角をβ（°）としたとき、α＞βとなるよう面取り加工することが好ましい。面取り加工手段は特に限定されない。例えば、前記内角αとβがα＞βとなるよう砥石を保持して回転させ、端部Ｂの先端に砥石を押付けながら当該先端の輪郭に沿って砥石を移動させることにより、面取りすることができる。 [Chamfering process]
FIG. 2 shows a cross section of the end B after the chamfering process. The inner angle of the first end portion 43 that is the end portion between the chamfered surface 40 and the outer side surface 41 of the spoke portion is α (°), and the second end is the end portion between the chamfered surface 40 and the back surface 42 of the spoke portion. When the internal angle of the portion 44 is β (°), chamfering is preferably performed so that α> β. The chamfering means is not particularly limited. For example, chamfering can be performed by holding and rotating the grindstone so that the internal angles α and β satisfy α> β, and moving the grindstone along the contour of the tip while pressing the grindstone against the tip of the end B. it can.

［丸め工程］
　図３～５は丸め工程における前記端部Ｂの処理手段の例を示す。丸め工程では、スポーク部の裏面４２側からブラシ９を当て、前記面取り工程で形成された第１端部４３を丸める第１丸め工程、および第２端部４４を丸める第２丸め工程を少なくとも含む。ブラシ９の長さは、ホイールを車に取り付ける取り付け面であるハブ部５とスポーク裏面４２とのディスク部中心軸方向の距離より、長いことが好ましい。具体的にはブラシ長さは５０ｍｍ～２００ｍｍ程度とすることが好ましく、ブラシ押付け圧力は０．０５～１．０ＭＰａ程度とすることが好ましい。図３はブラシ９が第１端部４３に当たる瞬間の状態を示す。第１端部４３にはブラシ９の先端に近い箇所が当たり、第２端部４４にはブラシ９のより下の箇所が当たる。ブラシ９は、図中矢印の方向へ進むことにより、各端部を丸めることとなる。図４は、図３に示す状態からブラシが少し進んだ状態を示す。第１端部４３からブラシ９は離れ、第２端部４４にはブラシ９が当たり続ける。図５は、図４に示す状態からブラシが更に進んだ状態を示す。第１端部４３からブラシ９は離れたままであり、第２端部４４にはブラシ９が当たり続ける。ブラシ９が第１端部４３に当たっている時間に比べて、第２端部４４に当たっている時間は長いことから、第１端部４３の研磨より第２端部４４の研磨の方がより速く進行する。第２端部４４の研磨が進み所定の曲率半径（Ｒ２）になったとき、第１端部４３の研磨量は、第２端部の研磨量より少ない。しかしながら、第１端部４３の内角α（°）は、第２端部４４の内角β（°）より大きい。そのため、図６の丸め工程後の端部Ｂの断面に示すように、第２端部４４の曲率半径（Ｒ２）が、厚い塗膜を形成することができるまで大きくなって、第２円弧面４６が形成されても、第１端部４３の曲率半径（Ｒ１）をより大きい値とする第１円弧面４５を形成することができる。なお、第１丸め工程と第２丸め工程は、これらの工程を同時に行うことや、別々に行うことができる。また、先に第１丸め工程を行うことや、先に第２丸め工程を行うこともできる。丸め工程の加工時間は、標準として５秒～３０秒である。 [Rounding process]
3 to 5 show examples of the processing means for the end B in the rounding step. The rounding step includes at least a first rounding step of applying the brush 9 from the back surface 42 side of the spoke portion and rounding the first end portion 43 formed in the chamfering step, and a second rounding step of rounding the second end portion 44. . The length of the brush 9 is preferably longer than the distance in the central axis direction of the disk portion between the hub portion 5 which is a mounting surface for attaching the wheel to the vehicle and the spoke back surface 42. Specifically, the brush length is preferably about 50 mm to 200 mm, and the brush pressing pressure is preferably about 0.05 to 1.0 MPa. FIG. 3 shows a state at the moment when the brush 9 hits the first end portion 43. A location close to the tip of the brush 9 hits the first end portion 43, and a location below the brush 9 hits the second end portion 44. The brush 9 rounds each end by proceeding in the direction of the arrow in the figure. FIG. 4 shows a state where the brush is slightly advanced from the state shown in FIG. The brush 9 is separated from the first end portion 43, and the brush 9 continues to hit the second end portion 44. FIG. 5 shows a state where the brush has further advanced from the state shown in FIG. The brush 9 remains away from the first end 43 and the brush 9 continues to hit the second end 44. Since the time for which the brush 9 is in contact with the first end 43 is longer than the time for which the brush 9 is in contact with the first end 43, the polishing of the second end 44 proceeds faster than the polishing of the first end 43. . When the polishing of the second end 44 progresses to a predetermined radius of curvature (R2), the polishing amount of the first end 43 is less than the polishing amount of the second end. However, the internal angle α (°) of the first end portion 43 is larger than the internal angle β (°) of the second end portion 44. Therefore, as shown in the cross section of the end portion B after the rounding step in FIG. 6, the radius of curvature (R2) of the second end portion 44 is increased until a thick coating film can be formed, and the second arc surface Even if 46 is formed, the 1st circular arc surface 45 which makes the curvature radius (R1) of the 1st end part 43 a larger value can be formed. In addition, a 1st rounding process and a 2nd rounding process can perform these processes simultaneously, or can be performed separately. Moreover, a 1st rounding process can be performed previously and a 2nd rounding process can also be performed previously. The processing time for the rounding process is typically 5 to 30 seconds.

　以下、実施例及び従来例に基づき本発明を更に具体的に説明するが、本発明は以下の実施例に何ら限定されるものではない。 Hereinafter, the present invention will be described more specifically based on examples and conventional examples, but the present invention is not limited to the following examples.

（実施例１）
［基体形成工程］
　低圧鋳造法により約４５０℃のＡｌ－Ｓｉ－Ｍｇ系合金（ＪＩＳ　ＡＣ４ＣＨ）の溶湯を、約４８０℃に加熱した金型に圧力０．５ｋｇ／ｃｍ^２～０．７ｋｇ／ｃｍ^２で注湯し、冷却後に金型から取り出すことにより、図８に示す車両用ホイールの基体１を作製した。抜け勾配γは、６０°とした。基体１のスポーク部６の裏面に切削加工を施し、図９に示す断面構造を有するスポーク部６を得た。スポーク部６の端部Ｂは鋭角であり、その内角θを３０°とした。 Example 1
[Substrate forming step]
The molten Al-Si-Mg alloy (JIS AC4CH) at about 450 ° C is poured into a mold heated to about 480 ° C at a pressure of 0.5kg / cm ² to 0.7kg / cm ² by low pressure casting. The substrate 1 of the vehicle wheel shown in FIG. 8 was produced by taking it out from the mold after cooling. The draft γ was 60 °. Cutting was performed on the back surface of the spoke portion 6 of the base 1 to obtain a spoke portion 6 having a cross-sectional structure shown in FIG. The end portion B of the spoke portion 6 is an acute angle, and the inner angle θ is 30 °.

［面取り工程］
　砥石を回転させて端部Ｂに押付けながら、当該端部Ｂの輪郭に沿って砥石を移動させることにより、端部Ｂを面取りし、内角αが１４０°の第１端部４３および内角βが７０°の第２端部４４を形成した（図２）。面取り加工により形成された面取り面４０の幅は約６００μｍとした。 [Chamfering process]
By rotating the grindstone and pressing it against the end portion B, the endstone B is chamfered by moving the grindstone along the contour of the end portion B, and the first end portion 43 and the inner angle β having an inner angle α of 140 ° are obtained. A 70 ° second end 44 was formed (FIG. 2). The width of the chamfered surface 40 formed by the chamfering process was about 600 μm.

［丸め工程］
　本工程では、スポーク部の裏面側からブラシを当て、前記面取り工程で形成された面取り面４０の第１端部４３および第２端部４４を丸めた。長さ１００ｍｍのブラシを押付け圧力０．２ＭＰａで、面取り工程後の端部Ｂに押付け、ホイール基体に対して周方向に相対移動させた。丸め工程の加工時間は標準時間とした。ブラシは端部Ｂを図３～５に示すように摺擦し、第１端部４３と第２端部４４を１段階の工程内で研磨し、それぞれの位置に第１円弧面４５と第２円弧面４６を形成した。第１円弧面４５の曲率半径Ｒ１は４５０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 [Rounding process]
In this step, a brush was applied from the back side of the spoke portion, and the first end portion 43 and the second end portion 44 of the chamfered surface 40 formed in the chamfering step were rounded. A brush with a length of 100 mm was pressed against the end B after the chamfering process at a pressing pressure of 0.2 MPa, and moved relative to the wheel base in the circumferential direction. The processing time of the rounding process was standard time. The brush rubs the end portion B as shown in FIGS. 3 to 5, polishes the first end portion 43 and the second end portion 44 in a single step, and the first arc surface 45 and the first end portion at each position. Two arcuate surfaces 46 were formed. The radius of curvature R1 of the first arc surface 45 was 450 μm, and the radius of curvature R2 of the second arc surface 46 was 300 μm.

［塗装工程］
　上記ホイール表面と裏面に、ポリエステル系粉体塗料を静電塗装することにより、プライマー層を形成した。塗装膜厚は表面で１００μｍ程度、裏面は２０μｍ程度とした。その後プライマー層上にアクリル系カラー塗料を、ホイールの表面と裏面に吹付け塗装してカラーベース層を形成した。乾燥膜厚は表面、裏面ともに２０μｍ程度とした。最後に、ホイールの表面にクリヤー塗料を塗装した。乾燥膜厚は２０μｍ程度とした。端部Ｂには、ほぼ均一の厚さの塗膜が形成された。図１５に示すように、第１円弧面４５の塗膜の膜厚をＴ１とし、スポーク部の外側の側面４１の塗膜の膜厚をＴ１０とした場合、Ｔ１とＴ１０との比Ｔ１／Ｔ１０を算出した。同様に、第２円弧面４６の塗膜の膜厚Ｔ２とし、スポーク部の裏面４２の塗膜の膜厚をＴ２０とした場合、Ｔ２とＴ２０との比Ｔ２／Ｔ２０を算出した。 [Painting process]
A primer layer was formed by electrostatically coating a polyester powder coating on the wheel front and back surfaces. The coating film thickness was about 100 μm on the front surface and about 20 μm on the back surface. Thereafter, an acrylic color paint was sprayed onto the primer layer and sprayed onto the front and back surfaces of the wheel to form a color base layer. The dry film thickness was about 20 μm on both the front and back surfaces. Finally, a clear paint was applied to the wheel surface. The dry film thickness was about 20 μm. A coating film having a substantially uniform thickness was formed on the end portion B. As shown in FIG. 15, when the film thickness of the coating film on the first arc surface 45 is T1, and the film thickness of the coating film on the side surface 41 outside the spoke portion is T10, the ratio T1 / T10 between T1 and T10. Was calculated. Similarly, assuming that the film thickness T2 of the coating film on the second arc surface 46 and the film thickness of the coating film on the back surface 42 of the spoke portion are T20, the ratio T2 / T20 of T2 and T20 was calculated.

［耐蝕性試験］
　上記ホイールをJIS Z 2371(CASS試験)準拠の中性塩水噴霧試験機およびキャス試験機に設置し、以下の条件で噴霧を２４０時間実施した。塩水噴霧終了後、ホイールを取り出し、水で洗浄、拭き取りし、スポーク部の端部Ｂ、特に第１円弧面と第２円弧面、及びそれらの近傍における表面状態の変化を目視観察した。 [Corrosion resistance test]
The wheel was installed in a neutral salt spray tester and a cast tester compliant with JIS Z 2371 (CASS test) and sprayed for 240 hours under the following conditions. After completion of spraying the salt water, the wheel was taken out, washed and wiped with water, and the change in the surface condition at the end B of the spoke portion, particularly the first and second arc surfaces and the vicinity thereof was visually observed.

中性塩水噴霧試験（SST：salt spray test）（JIS Z 2371準拠）
　・試験液：塩化ナトリウム 50±5g/L、pH=6.5～7.2
　・噴霧室内温度：35±2℃
　・噴霧量：1.5±0.5mL/h(80cm²) Neutral salt spray test (SST: salt spray test) (conforms to JIS Z 2371)
・ Test solution: Sodium chloride 50 ± 5g / L, pH = 6.5-7.2
-Spraying room temperature: 35 ± 2 ° C
・ Amount of spray: 1.5 ± 0.5mL / h (80cm ² )

キャス試験（CASS test：copper accelerated acetic acid salt spray test）（JIS Z 2371準拠）
・試験液：塩化ナトリウム　50±5g/L
　　　　　　塩化銅(II)　0.205±0.015g/L
　　　　　　pH=3.1～3.3(酢酸酸性)
・噴霧室内温度：50±2℃
・噴霧量：1.5±0.5mL/h(80cm²) CASS test (copper accelerated acetic acid salt spray test) (conforms to JIS Z 2371)
・ Test solution: Sodium chloride 50 ± 5g / L
Copper (II) chloride 0.205 ± 0.015g / L
pH = 3.1-3.3 (Acetic acid acidity)
-Spraying room temperature: 50 ± 2 ℃
・ Amount of spray: 1.5 ± 0.5mL / h (80cm ² )

（実施例２）
　第１端部の内角αを１３０°、第２端部の内角βを８０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は４００μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 (Example 2)
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle α of the first end was 130 ° and the internal angle β of the second end was 80 °. The curvature radius R1 of the first arc surface 45 was 400 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（実施例３）
　第１端部の内角αを１２０°、第２端部の内角βを９０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は３５０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 Example 3
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle α of the first end was 120 ° and the internal angle β of the second end was 90 °. The curvature radius R1 of the first arc surface 45 was 350 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（実施例４）
　内角θを６０°、第１端部の内角αを１３０°、第２端部の内角βを１１０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は４５０μｍ、第２円弧面４６の曲率半径Ｒ２は４００μｍであった。 Example 4
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 60 °, the internal angle α of the first end was 130 °, and the internal angle β of the second end was 110 °. went. The radius of curvature R1 of the first arc surface 45 was 450 μm, and the radius of curvature R2 of the second arc surface 46 was 400 μm.

（実施例５）
　内角θを６０°、第１端部の内角αを１５０°、第２端部の内角βを９０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は５００μｍ、第２円弧面４６の曲率半径Ｒ２は４００μｍであった。 (Example 5)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 60 °, the internal angle α of the first end was 150 °, and the internal angle β of the second end was 90 °. went. The radius of curvature R1 of the first arc surface 45 was 500 μm, and the radius of curvature R2 of the second arc surface 46 was 400 μm.

（実施例６）
　内角θを６０°、第１端部の内角αを１６０°、第２端部の内角βを８０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は５５０μｍ、第２円弧面４６の曲率半径Ｒ２は４００μｍであった。 (Example 6)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 60 °, the internal angle α of the first end portion was 160 °, and the internal angle β of the second end portion was 80 °. went. The curvature radius R1 of the first arc surface 45 was 550 μm, and the curvature radius R2 of the second arc surface 46 was 400 μm.

（実施例７）
　内角θを８０°、第１端部の内角αを１７０°、第２端部の内角βを９０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は５５０μｍ、第２円弧面４６の曲率半径Ｒ２は４００μｍであった。 (Example 7)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1, except that the internal angle θ was 80 °, the internal angle α of the first end portion was 170 °, and the internal angle β of the second end portion was 90 °. went. The curvature radius R1 of the first arc surface 45 was 550 μm, and the curvature radius R2 of the second arc surface 46 was 400 μm.

（実施例８）
　内角θを８０°、第１端部の内角αを１５０°、第２端部の内角βを１１０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は５００μｍ、第２円弧面４６の曲率半径Ｒ２は４００μｍであった。 (Example 8)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 80 °, the internal angle α of the first end was 150 °, and the internal angle β of the second end was 110 °. went. The radius of curvature R1 of the first arc surface 45 was 500 μm, and the radius of curvature R2 of the second arc surface 46 was 400 μm.

（実施例９）
　内角θを８０°、第２端部の内角βを１２０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は４５０μｍ、第２円弧面４６の曲率半径Ｒ２は４００μｍであった。 Example 9
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 80 ° and the internal angle β of the second end portion was 120 °. The radius of curvature R1 of the first arc surface 45 was 450 μm, and the radius of curvature R2 of the second arc surface 46 was 400 μm.

（実施例１０）
　丸め工程の加工時間を標準時間の０．５倍、第１円弧面４５の曲率半径Ｒ１を３００μｍ、第２円弧面４６の曲率半径Ｒ２を１８０μｍとした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。 (Example 10)
Except that the rounding process time is 0.5 times the standard time, the radius of curvature R1 of the first arcuate surface 45 is 300 μm, and the radius of curvature R2 of the second arcuate surface 46 is 180 μm, the same as in Example 1. The wheel was manufactured under the conditions and the corrosion resistance test was performed.

（実施例１１）
　内角θを６０°、第１端部の内角αを１５０°、第２端部の内角βを９０°、丸め工程の加工時間を標準時間の０．５倍とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は２００μｍ、第２円弧面４６の曲率半径Ｒ２は１８０μｍであった。 (Example 11)
Example except that the internal angle θ is 60 °, the internal angle α of the first end is 150 °, the internal angle β of the second end is 90 °, and the processing time of the rounding process is 0.5 times the standard time. A wheel was prepared and a corrosion resistance test was performed under the same conditions as in No. 1. The curvature radius R1 of the first arc surface 45 was 200 μm, and the curvature radius R2 of the second arc surface 46 was 180 μm.

（実施例１２）
　内角θを８０°、第１端部の内角αを１７０°、第２端部の内角βを９０°、丸め工程の加工時間を標準時間の０．５倍とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は２５０μｍ、第２円弧面４６の曲率半径Ｒ２は１６０μｍであった。 Example 12
Example, except that the internal angle θ is 80 °, the internal angle α of the first end is 170 °, the internal angle β of the second end is 90 °, and the processing time of the rounding process is 0.5 times the standard time. A wheel was prepared and a corrosion resistance test was performed under the same conditions as in No. 1. The curvature radius R1 of the first arc surface 45 was 250 μm, and the curvature radius R2 of the second arc surface 46 was 160 μm.

（実施例１３）
　面取り面４０の幅を約１０００μｍ、内角θを６０°、第１端部の内角αを１６０°、第２端部の内角βを８０°、丸め工程の加工時間を標準時間の３倍とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は８００μｍ、第２円弧面４６の曲率半径Ｒ２は７００μｍであった。 (Example 13)
The width of the chamfered surface 40 is about 1000 μm, the inner angle θ is 60 °, the inner angle α of the first end is 160 °, the inner angle β of the second end is 80 °, and the processing time of the rounding process is three times the standard time. Except for this point, a wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 1. The radius of curvature R1 of the first arc surface 45 was 800 μm, and the radius of curvature R2 of the second arc surface 46 was 700 μm.

（比較例１）
　内角θを３０°、第１端部の内角αを１０５°、第２端部の内角βを１０５°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は１５０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 (Comparative Example 1)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 30 °, the internal angle α of the first end portion was 105 °, and the internal angle β of the second end portion was 105 °. went. The curvature radius R1 of the first arc surface 45 was 150 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（比較例２）
　内角θを６０°、第１端部の内角αを１２０°、第２端部の内角βを１２０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は１５０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 (Comparative Example 2)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 60 °, the internal angle α of the first end was 120 °, and the internal angle β of the second end was 120 °. went. The curvature radius R1 of the first arc surface 45 was 150 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（比較例３）
　内角θを８０°、第１端部の内角αを１３０°、第２端部の内角βを１３０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は１５０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 (Comparative Example 3)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 80 °, the internal angle α of the first end portion was 130 °, and the internal angle β of the second end portion was 130 °. went. The curvature radius R1 of the first arc surface 45 was 150 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（比較例４）
　第１端部の内角αを９０°、第２端部の内角βを１２０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は８０μｍ、第２円弧面４６の曲率半径Ｒ２は１５０μｍであった。 (Comparative Example 4)
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle α of the first end was 90 ° and the internal angle β of the second end was 120 °. The curvature radius R1 of the first arc surface 45 was 80 μm, and the curvature radius R2 of the second arc surface 46 was 150 μm.

（比較例５）
　内角θを６０°、第１端部の内角αを９０°、第２端部の内角βを１５０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は９０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 (Comparative Example 5)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 60 °, the internal angle α of the first end was 90 °, and the internal angle β of the second end was 150 °. went. The curvature radius R1 of the first arc surface 45 was 90 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（比較例６）
　内角θを８０°、第１端部の内角αを９０°、第２端部の内角βを１７０°とした点を除いて、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は８０μｍ、第２円弧面４６の曲率半径Ｒ２は３００μｍであった。 (Comparative Example 6)
The wheel was manufactured and the corrosion resistance test was performed under the same conditions as in Example 1 except that the internal angle θ was 80 °, the internal angle α of the first end was 90 °, and the internal angle β of the second end was 170 °. went. The curvature radius R1 of the first arc surface 45 was 80 μm, and the curvature radius R2 of the second arc surface 46 was 300 μm.

（比較例７）
　丸め工程の加工時間を標準時間の７倍とした他は、実施例１と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は１５０μｍ、第２円弧面４６の曲率半径Ｒ２は８００μｍであった。 (Comparative Example 7)
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 1 except that the processing time of the rounding step was set to 7 times the standard time. The curvature radius R1 of the first arc surface 45 was 150 μm, and the curvature radius R2 of the second arc surface 46 was 800 μm.

（比較例８）
　丸め工程の加工時間を標準時間の５倍とした他は、実施例４と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は１５０μｍ、第２円弧面４６の曲率半径Ｒ２は９００μｍであった。 (Comparative Example 8)
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 4 except that the processing time of the rounding step was set to 5 times the standard time. The curvature radius R1 of the first arc surface 45 was 150 μm, and the curvature radius R2 of the second arc surface 46 was 900 μm.

（比較例９）
　丸め工程の加工時間を標準時間の６倍とした他は、実施例７と同一の条件でホイールの作製と耐蝕性試験を行った。第１円弧面４５の曲率半径Ｒ１は１００μｍ、第２円弧面４６の曲率半径Ｒ２は９００μｍであった。 (Comparative Example 9)
A wheel was manufactured and a corrosion resistance test was performed under the same conditions as in Example 7 except that the processing time of the rounding step was set to 6 times the standard time. The curvature radius R1 of the first arc surface 45 was 100 μm, and the curvature radius R2 of the second arc surface 46 was 900 μm.

　実施例および比較例の実施条件と試験結果を表１に示す。スポーク部６の外側の側面４１の窓部７に臨む端部、又はスポーク部６の裏面４２の窓部７に臨む端部において最も錆が発生しやすい。ＳＳＴおよびＣＡＳＳ評価における錆の評価は、端部の錆が無いものを○（良好）、局所的な錆が認められるものを△（錆は認められるが許容範囲内である）、連続の錆が認められるものを×（不良）とした。何れの端部においてもＳＳＴ評価およびＣＡＳＳ評価で何れの評価も○、又は一方が○で他方が△のとき耐蝕性に優れた車両用ホイールが得られたと判断する。局所的な錆の模式図を図８に示す。図８に示す錆の程度を局所的な錆の限度とし、これより進展した錆を連続の錆とする。独立した糸状の錆５１がスポーク部６の外側の側面４１の窓部７に臨む端部、又はスポーク部６の裏面４２の窓部７に臨む端部に生じたとしても、局所的な錆であればホイールの強度や意匠性に影響しない。特に、スポーク部６の裏面４２の窓部７に臨む端部に生じた局所的な錆は、ディスク面の表側からは視認しにくいため、意匠性に与える影響は特に小さい。 Table 1 shows the working conditions and test results of the examples and comparative examples. Rust is most likely to occur at the end facing the window 7 on the outer side surface 41 of the spoke 6 or the end facing the window 7 on the back surface 42 of the spoke 6. Evaluation of rust in SST and CASS evaluation is as follows: ○ (good) when there is no rust at the end, △ (where rust is recognized but within an allowable range) where local rust is recognized, and continuous rust What was recognized was made into x (defect). At any end, it is determined that a vehicle wheel having excellent corrosion resistance is obtained when either evaluation is “good” in SST evaluation and CASS evaluation, or one is “good” and the other is “△”. A schematic diagram of local rust is shown in FIG. The extent of rust shown in FIG. 8 is defined as the local rust limit, and rust that has developed further is defined as continuous rust. Even if independent thread-like rust 51 occurs at the end facing the window 7 on the outer side surface 41 of the spoke 6 or the end facing the window 7 on the back surface 42 of the spoke 6, If there is, it does not affect the strength and design of the wheel. In particular, local rust generated at the end facing the window portion 7 on the back surface 42 of the spoke portion 6 is difficult to visually recognize from the front side of the disk surface, and thus the influence on the design is particularly small.

　本発明の実施例１～９の何れのホイールでも、スポーク部の縁部において十分な厚さの塗膜が形成されたため、ＳＳＴおよびＣＡＳＳのいずれにおいても錆の発生は認められなかった。また、実施例１０～１２では、Ｒ２において塗膜の薄い部分から局所的な錆が若干認められたものの、ホイール性能に影響のない許容範囲内のものであった。Ｒ２の錆はディスク面の表側からは視認しにくいため、意匠性に与える影響は特に小さかった。実施例１３では、錆の発生は認められなかったが、丸め工程の加工時間が長いため生産性が劣った。 In any of the wheels of Examples 1 to 9 of the present invention, since a sufficiently thick coating film was formed at the edge of the spoke part, no rust was observed in either SST or CASS. In Examples 10 to 12, although local rust was slightly observed from the thin part of the coating film in R2, it was within an allowable range that does not affect the wheel performance. Since the rust of R2 is difficult to visually recognize from the front side of the disk surface, the influence on the design is particularly small. In Example 13, although generation | occurrence | production of rust was not recognized, since the processing time of the rounding process was long, productivity was inferior.

　これに対して比較例のホイールでは、スポーク部の第１円弧面の曲率半径Ｒ１が小さいことに起因して、特に第１円弧面の塗膜が薄くなった結果、防食性に劣り、連続的な糸錆の発生が認められた。比較例７～８では丸め工程の加工時間が長過ぎるためＲ１は増加から減少に転じ、ブラシ加工によって新たな端部が形成された。Ｒ１において錆の発生が認められた。 On the other hand, in the wheel of the comparative example, due to the small radius of curvature R1 of the first arc surface of the spoke part, the coating film of the first arc surface was particularly thin, resulting in poor corrosion resistance and continuous. Generation of rust was observed. In Comparative Examples 7 to 8, since the processing time of the rounding process was too long, R1 changed from increasing to decreasing, and a new end was formed by brushing. Generation of rust was observed in R1.

１　　　ホイール（基体）
２　　　リム部
３　　　ハブ穴
４　　　ボルト穴
５　　　ハブ部
６　　　スポーク部
７　　　窓部
８　　　ディスク部
９　　　ブラシ
１０　　ブラシの自由端
４０　　面取り面
４１　　スポーク部の外側の側面
４２　　スポーク部の裏面
４３　　第１端部
４４　　第２端部
４５　　第１円弧面
４６　　第２円弧面
５０　　塗膜
５１　　局所的な錆
１０１　基体形成工程
１０２　熱処理工程
１０３　加工工程
１０４　面取り工程
１０５　丸め工程
１０６　塗装前処理工程
１０７　塗装工程
Ｒ１　　第１円弧面の曲率半径
Ｒ２　　第２円弧面の曲率半径
α　　　第１端部の内角
β　　　第２端部の内角
Ｂ　　　端部
Ｔ１　　第１円弧面の塗膜の膜厚
Ｔ２　　第２円弧面の塗膜の膜厚
Ｔ１０　スポーク部の外側の側面の塗膜の膜厚
Ｔ２０　スポーク部の裏面の塗膜の膜厚 1 Wheel (base)
2 Rim part 3 Hub hole 4 Bolt hole 5 Hub part 6 Spoke part 7 Window part 8 Disk part 9 Brush 10 Brush free end 40 Chamfered surface 41 Side surface outside spoke part 42 Back surface 43 of spoke part First end part 44 2 end 45 first arc surface 46 second arc surface 50 coating 51 local rust 101 base forming process 102 heat treatment process 103 processing process 104 chamfering process 105 rounding process 106 pre-painting process 107 coating process R1 first arc surface Radius of curvature R2 radius of curvature α of the second arc surface inner angle β of the first end portion inner angle B of the second end portion end portion T1 film thickness of the coating film on the first arc surface T2 film thickness of the coating film on the second arc surface T10 Film thickness on the outer side of the spoke part T20 Film thickness on the back side of the spoke part

Claims

　タイヤを装着する円環形状のリム部、車両用ホイールを車軸に接続するハブ穴を有するハブ部、前記ハブ部から前記リム部に向かって放射状に延びて当該ハブ部および当該リム部をつなぐスポーク部、並びに前記リム部、前記ハブ部および前記スポーク部で囲まれた空間である窓部を少なくとも備える車両用ホイールの製造方法であって、
　前記スポーク部の裏面と前記窓部との境界に位置する、当該裏面と前記スポーク部の側面との端部を面取りして面取り面を形成する面取り工程と、
　前記面取り面と前記スポーク部の側面との端部である第１端部を丸めて第１円弧面を形成する第１丸め工程と、前記面取り面と前記スポーク部の裏面との端部である第２端部を丸めて第２円弧面を形成する第２丸め工程を含む丸め工程を少なくとも含み、
　前記第１円弧面の曲率半径Ｒ１は、前記第２円弧面の曲率半径Ｒ２よりも大きい、車両用ホイールの製造方法。 An annular rim portion for mounting a tire, a hub portion having a hub hole for connecting a vehicle wheel to an axle, and a spoke extending radially from the hub portion toward the rim portion and connecting the hub portion and the rim portion And a vehicle wheel manufacturing method comprising at least a window portion which is a space surrounded by the rim portion, the hub portion and the spoke portion,
A chamfering step for chamfering an end portion of the back surface and the side surface of the spoke portion located at a boundary between the back surface of the spoke portion and the window portion to form a chamfered surface;
A first rounding step of rounding a first end which is an end of the chamfered surface and a side surface of the spoke portion to form a first arc surface, and an end of the chamfered surface and the back surface of the spoke portion. At least a rounding step including a second rounding step of rounding the second end to form a second arc surface;
The vehicle wheel manufacturing method, wherein a curvature radius R1 of the first arc surface is larger than a curvature radius R2 of the second arc surface.
　前記第１端部の内角αは、前記第２端部の内角βよりも大きい、請求項１記載の車両用ホイールの製造方法。 The method for manufacturing a vehicle wheel according to claim 1, wherein an inner angle α of the first end portion is larger than an inner angle β of the second end portion.
　前記丸め工程は、
　前記ハブ部、前記スポーク部および前記窓部からなるディスク部の裏面側にブラシを配置するブラシ配置工程と、
　前記ブラシと前記ディスク部の裏面とを相対移動させて、当該ブラシで前記第１端部および前記第２端部を摺擦して前記第１円弧面および前記第２円弧面を形成する摺擦工程を少なくとも含み、
　前記摺擦工程により、前記第１円弧面の曲率半径Ｒ１を前記第２円弧面の曲率半径Ｒ２よりも大きくする請求項１又は２に記載の車両用ホイールの製造方法。 The rounding step
A brush disposing step of disposing a brush on the back side of the disk portion comprising the hub portion, the spoke portion, and the window portion;
Rubbing that forms the first arc surface and the second arc surface by moving the brush and the back surface of the disk portion relative to each other and rubbing the first end portion and the second end portion with the brush. Including at least a step,
The method for manufacturing a vehicle wheel according to claim 1 or 2, wherein a radius of curvature R1 of the first arc surface is made larger than a radius of curvature R2 of the second arc surface by the rubbing step.
　前記ブラシは回転軸を有するロール型ブラシであり、
　前記摺擦工程は、当該ロール型ブラシの回転軸が前記ディスク部の裏面と平行にして回転すると共に、前記ディスク部の裏面に対して同心状に相対回転して摺擦する工程である請求項３に記載の車両用ホイールの製造方法。 The brush is a roll type brush having a rotating shaft,
The rubbing step is a step in which the rotation axis of the roll-type brush rotates in parallel with the back surface of the disc portion and is rubbed by relatively rotating concentrically with the back surface of the disc portion. 4. A method for manufacturing a vehicle wheel according to 3.
　タイヤを装着する円環形状のリム部、車両用ホイールを車軸に接続するハブ穴を有するハブ部、前記ハブ部から前記リム部に向かって放射状に延びて当該ハブ部および当該リム部をつなぐスポーク部、並びに前記リム部、前記ハブ部および前記スポーク部で囲まれた空間である窓部を少なくとも備える車両用ホイールであって、
　前記スポーク部の裏面と前記窓部との境界に位置する、当該裏面と前記スポーク部の側面との端部は、前記スポーク部の側面と接する円弧面である第１円弧面と、前記スポーク部の裏面と接する円弧面である第２円弧面を備え、
　前記第１円弧面の曲率半径Ｒ１は、前記第２円弧面の曲率半径Ｒ２よりも大きい、車両用ホイール。 An annular rim portion for mounting a tire, a hub portion having a hub hole for connecting a vehicle wheel to an axle, and a spoke extending radially from the hub portion toward the rim portion and connecting the hub portion and the rim portion Vehicle wheel including at least a window portion that is a space surrounded by a portion, and the rim portion, the hub portion, and the spoke portion,
An end portion of the back surface and the side surface of the spoke portion located at a boundary between the back surface of the spoke portion and the window portion is a first arc surface that is an arc surface in contact with the side surface of the spoke portion, and the spoke portion. A second arc surface that is an arc surface in contact with the back surface of
The vehicle wheel, wherein a radius of curvature R1 of the first arc surface is larger than a radius of curvature R2 of the second arc surface.
　前記第２円弧面の曲率半径Ｒ２は、２００μｍ以上６００μｍ以下である請求項５に記載の車両用ホイール。
The vehicle wheel according to claim 5, wherein a curvature radius R <b> 2 of the second arc surface is 200 μm or more and 600 μm or less.