JP2004106719A - Manufacturing method for rim wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for highly productive manufacturing of a rim wheel which suppresses vibrations transmitted to a vehicle, improves riding comfortableness, reduces noises in a cabin, and reduces possible causes of a failure such as defective welding, while ensuring a high maneuvering stability. <P>SOLUTION: In the case of manufacturing the rim wheel which is provided with two or more sub air chambers 6 formed by a rim 2 and an air chamber wall 3 annularly formed in a peripheral direction by straddling over the outer peripheral surface top of the rim 2 and one bead sheet 4 and divided by two or more bulkheads 5 arranged at appropriate intervals in the peripheral direction, and a communicating section formed in the air chamber wall 3 and communicating a main air chamber 11 with the sub air chambers 6, wherein the sub air chambers 6 and the communicating section form a Helmholtz resonant absorber, the air chamber wall 3 is formed by (1) a bending process to bend an approximately flat circular arc plate-like member into a regulated shape, and (II) a fixing process to fix the plate-like member by extending over between the peripheral surface top of the rim 2 and one bead sheet 4. <P>COPYRIGHT: (C)2004,JPO

Description

ｆ_０：共鳴周波数（Ｈｚ）
Ｖ：副気室体積（ｃｍ^３）
Ｓ：連通部総断面積（ｃｍ^２）
Ｌ：連通部長さ（ｃｍ）
Ｎ：連通部個数／気室
Ｒ：ホイール径（ｉｎｃｈ）
に従い設定することにより、効果的な空洞共鳴音低減を達成することができる。即ち、最初にリム径を決め、その後、副気室体積Ｖ（ｃｍ^３）、連通部総断面積Ｓ（ｃｍ^２）、連通部長さＬ（ｃｍ）、連通部個数Ｎを決定することにより、効果的にタイヤ空洞共鳴音を低減することができるリムホイールが得られる。ここで、上記式の左項は、ヘルムホルツ共鳴周波数を表している。タイヤ主気室内の空洞共鳴周波数は、タイヤとリムの周長によって決まり、径の小さいタイヤでは、この周波数は高くなり、径の大きなタイヤでは低くなる。上記式の右項は、タイヤサイズ、リム径に応じた最適な設定周波数範囲を求めたものである。
【００１５】
また、副気室を作る手法としては、これまでに、副気室を構成する側面の壁と上面の壁とを別個の部材として、夫々リムの外周面上とビードシートとに溶接等により固着する方法が考えられ実施されているが、前記〈１〉記載の本発明の製造方法においては、副気室の側面および上面の壁を１つの気室壁により形成している。そのため、固着箇所の数を削減することができ、これに伴い溶接などの結合作業を従来に比し大幅に削減することができるので、溶接部の剥離などの溶接欠陥による故障を防止することができるとともに、工程数の削減により生産性を良好に向上することができる。
【００１６】
前記〈２〉の本発明の製造方法では、リムホイール鋳造時に隔壁を成型するので、隔壁設置のための工程を省くことができるとともに、溶接等によりリム外周面上に隔壁を設置する場合に比して、溶接欠陥などによる故障の発生をより低減することができる。
【００１７】
また、前記〈３〉の本発明の製造方法により、隔壁を溶接等により形成する場合でも、前記〈２〉の製造方法の場合と同様に、上記式に従い効果的な空洞共鳴音低減を達成することができる。
【００１８】
前記〈４〉の本発明の製造方法では、副気室が３個以上の密閉隔壁によって周方向に３気室以上に形成されていることによって、共鳴吸音遅れが生じることなく、タイヤ空洞共鳴音を効果的に低減することができる。好ましくは、副気室数は４室以上であり、より好ましくは５室以上である。
【００１９】
前記〈５〉の本発明の製造方法により連通部を穿設することで、上記式に従い、効果的な空洞共鳴音低減を達成することができる。なお、連通部は各副気室に対し１個に限定されるものではなく、連通部の径や数を調整するだけで、共鳴周波数設定を変えることができることから、連通部の数、位置および径はタイヤサイズに応じ適宜定めればよい。
【００２０】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照しつつ具体的に説明する。
図１は、本発明の一好適例に係るリムホイール１のリム２にタイヤ１０を装着した状態を示す断面部斜視図である。図示するように、リムホイール１においては、タイヤ１０がこのリムホイール１のリム２に装着されることにより、タイヤ１０とリム２との間に密閉されたタイヤ主気室１１が形成されるが、本発明においては、この主気室１１に連通する副気室６が設けられていることにより、ヘルムホルツ共鳴吸音器が構成されている。本発明の製造方法は、主として、このヘルムホルツ共鳴吸音器を構成する副気室６の形成工程に係るものである。
【００２１】
図示するように、副気室６は、リム２と、その外周面上と一方のビードシート４（矢印ＩＮ方向側）との間に跨って周方向に環状に形成された気室壁３とにより形成されており、図中のＡ−Ａ線に沿う周方向断面図である図３に示すように、周方向に適宜間隔をあけて設けられた複数の隔壁５により分割されている。気室壁３には、図３に示すような連通部８が穿設されており、これによりタイヤ主気室１１と副気室６とが連通して、ヘルムホルツ共鳴吸音器を構成している。
【００２２】
本発明においては、副気室６を構成する気室壁３を形成するにあたり、図２（イ）に示すような平面略円弧状の板状部材９を用い、これを既定の形状に曲げる曲げ加工を行った後（曲げ工程（Ｉ））、リム２の外周面上と一方のビードシート４との間に跨って固着する（固着工程（ＩＩ））。これにより、従来の、副気室の側面と上面の壁を夫々別部材として副気室６を形成する方法に比して固着箇所の数および工程数を削減することができ、溶接欠陥などによる故障を良好に防止できるとともに、生産性を向上することができる。ビードシート４側の固着部については、例えば、図１に示すように適宜高さおよび形状の段部４Ａを設けて、この段部４Ａにおいて板状部材９と固着させればよい。
【００２３】
図２（ロ）は、曲げ加工後の板状部材９の略円弧状の両端部を合わせて固着した状態を示しており、図２（ハ）は、図２（ロ）中のＢ−Ｂ線に沿う中心軸方向断面図である。図示するように、平面略円弧状の板状部材９の両端部を溶接や接着等により接合することで、リング状の部材が構成される。従って本発明においては、かかる板状部材９をリム２の周方向に沿ってリム２の外周面上と一方のビードシート４との間に跨って巻回し、その両端部を図２（ロ）に示すようにして接合することで、図１に示すような気室壁３を形成することができる。
【００２４】
また、気室壁は、例えば、図４に示すような形状とすることもできる。図４に示す気室壁１３についても、図２（イ）に示すような平面略円弧状の板状部材９を用いて、これに適宜曲げ加工を施し、図５（イ）および（ロ）に示すようなリング状の部材とすることで、図１の気室壁３の場合と同様に形成することができる。
【００２５】
板状部材９は、リム２の径およびビードシート４の高さに合わせて、所望体積の副気室６を形成することができるよう適宜寸法（円弧の径、周方向長さおよび幅等）にて形成すればよい。材質としては、通常用いられている材料を適宜選択して使用することが可能であり、例えば、軽量で取り扱い性に優れたアルミ材などを用いることが好ましい。
【００２６】
気室壁３とリム２の外周面およびビードシート４との間の固着は溶接により行うことができ、これにより気密性の高い副気室６が得られる。また、溶接以外の方法として、接着により固着を行うこともできる。接着に用いる接着剤としては、例えば、ゴム系接着剤（例えば、コニシ株式会社製　弾力性エポキシ接着剤ボンドＭＯＳ７（商品名）、セメダイン株式会社製　弾性接着剤ＰＭシリーズ（商品名）等）などを用いることができる。
【００２７】
各副気室６の隣接する側面の壁を構成する隔壁５は、リムホイール鋳造時に、リム２と一体的に成型することにより形成することが好ましい。この場合、リムホイールの鋳造後に新たに隔壁５を形成する工程を行う必要がないので、固着箇所および工程の数をより削減することができ、生産性向上や故障防止にさらに寄与することができる。この際の鋳造法としては、従来の手法をそのまま用いることができる。
【００２８】
隔壁５をリム２と一体成型しない場合には、気室壁３の形成に先立って、別途作製した隔壁５を、リム２の外周面に溶接または接着により固着することが必要となるが、この場合でも、本発明に係る気室壁３による生産性向上および故障防止の効果は得ることができる。なお、隔壁５を接着により固着する場合に用いる接着剤としては、上記した気室壁３の場合と同様のものを用いることができる。
【００２９】
また、各副気室６の気密性を得るためには、副気室６を分割する隔壁５の径方向外端部と気室壁３との間も固着することが必要であるが、この隔壁５と気室壁３との間の固着についても、接着により好適に行うことができる。
【００３０】
ここで、図示する好適例においては、リムホイール本体に、タイヤ装着時にタイヤビード部を落とし込むための凹状のウエル部７が形成されている。このウエル部７の底部は、ビードシート４よりもタイヤ径方向内側に位置している。
【００３１】
ウエル部７は、適宜、軸方向に幅広または径方向内側に深い構造とすることができる。ここで、径方向内側に深い構造とは、ビード部とホイールベース部の径差が大きいという意味であり、ブレーキスペースに余裕がある場合は、ホイールベース部の径を小さくすることで径差を大きくできるが、余裕がない場合はビード部の径を大きくして、タイヤ高さを小さくする（タイヤ外径を同じにする）、いわゆるインチアップ手法により径差を大きくすることができる。
【００３２】
ウエル部７を軸方向に幅広にすることに対しては、実質的に大きな制約はないため、ウエル部７を幅広化しつつ、副気室６の所望体積を得ることも可能であるが、より大きな体積を確保できるという観点からは、径方向内側に深く形成することが好ましい。
【００３３】
即ち、リム２にウエル部７を形成しつつ、所望体積の副気室６を形成する場合には、気室壁３のリム２に対する固着部を、リム２の軸方向略中央に配置することが好ましい。これにより、従来通りタイヤをリムに組み付けることができる。
【００３４】
図３に示すように、連通部８は、タイヤ主気室１１と副気室６との間の連通を取るために、副気室６ごとに気室壁３に設けられている。連通部８は、気室壁３をリム２の外周面およびビードシート４に対し固着した後に穿設することもできるが、気室壁３を構成する板状部材９に対し、ドリル等によりあらかじめ設けておくことが好ましい。連通部８の位置にも特に制限はないが、図示する好適例では、効果的な空洞共鳴音低減を達成する上で好ましいとの観点から、副気室６の周方向長さの略中央部、即ち、隣接する隔壁５間の周方向長さの略中央部において、気室壁３に連通部８が穿設されている。
【００３５】
図３に示す好適実施形態においては、周方向に等間隔に５箇所の隔壁９を設けることで、夫々隣接する副気室間で隔壁９を共有して、５室の副気室６が配置されている。５室の副気室６は、夫々１個づつ設けられた連通部８を介してタイヤ主気室１１に連通されており、本実施形態では、これら副気室６と連通部８とで計５個のヘルムホルツ共鳴吸音器が構成されている。
【００３６】
ここで、リムホイール１にタイヤ１０を組立てた場合、前記式を満足するように、各部の設定を行う。タイヤ主気室内の空洞共鳴周波数は、タイヤとリムの周長によって決まり、通常の乗用車用タイヤでは、２５０Ｈｚ近傍が空洞共鳴周波数である。軽自動車用のタイヤではこの周波数が高周波になり、トラック用の大きなタイヤでは低周波になる。
【００３７】
なお、一つのリムホイール１に対する副気室６の総内容積は、タイヤ主気室１１の体積の２％以上２５％以下であることが好ましく、中でも３％以上１５％以下が更に好ましい。
【００３８】
本実施形態のリムホイール（６ＪＪ１５）１にタイヤ（１９５／５５Ｒ１５）１０を装着したときのタイヤ主気室１１の体積は約２２０００ｃｍ^３であり、５つの副気室６の総体積は１５００ｃｍ^３（３００ｃｍ^３×５個）であり、５つの副気室６の総体積はタイヤ主気室１１の総体積の６．９％である。
【００３９】
【実施例】
以下、本発明を実施例に基づき説明する。
従来のリムホイールとタイヤとの組み合わせ品（比較例（コントロール品））と、本発明により製造したリムホイールとタイヤとの組み合わせ品（実施例）とを試作し、ロードノイズ評価ドラム試験を実施した。
【００４０】
コントロール品：６ＪＪ１５の通常のアルミホイールに１９５／５５Ｒ１５サイズの通常の乗用車用タイヤを装着したものである。
【００４１】
実施例：図２に示すようなアルミニウム製の板状部材９を用いて製造した図１および図３に示す構造のリムホイール（隔壁数５個）にコントロール品と同様の乗用車用タイヤを装着したものである。
【００４２】
タイヤ主気室の体積約２２０００ｃｍ^３に対し、副気室の総体積は１５００ｃｍ^３（タイヤ主気室の６．９％）であり、連通部の径は０．８ｃｍ、連通部の長さは０．２ｃｍである。
【００４３】
実施例および比較例の共鳴周波数は、上記式に従い、それぞれ約２５０Ｈｚとした。ロードノイズドラムは直径３ｍで、表面に一般的な道路形状を模したアスファルトが貼り付けてある。タイヤを荷重３９２０Ｎ（４００ｋｇｆ）でドラムに押し付け、速度６０ｋｍ／ｈで走行させた際の、各方向のドラム軸力を測定し、周波数解析を行った。
【００４４】
上下方向の軸力の周波数解析を行った結果、実施例では、比較例に比し空洞共鳴ピークが約８．７ｄＢ低減した。
【００４５】
また、実施例および比較例のタイヤを乗用車に装着し、テストコースにて、テストドライバー二人による実車走行を行い、操縦安定性試験および振動乗り心地試験を実施した。
【００４６】
操縦安定性に関しては、駆動性、制動性、ハンドル応答性、操縦時のコントロール性を総合評価し、振動乗り心地試験に関しては、良路走行時振動、悪路走行時振動、段差などの特殊路走行時振動、車内騒音を総合評価し、コントロール（比較例）を１００とした時の指数で実施例のタイヤを評価した。指数の数値が大きいほど良好である。実施例の結果は、操縦安定性が１１０、振動乗り心地性が１１５、車内騒音が１５５であった。
【００４７】
【発明の効果】
以上説明してきたように、本発明によれば、高い操縦安定性を確保しつつ車両に伝達される振動を抑制し、乗り心地性の向上、車内騒音の低減等を実現でき、溶接欠陥などによる故障原因の低減したリムホイールを高い生産性にて製造することができる。
【図面の簡単な説明】
【図１】本発明の一好適実施形態に係るリムホイールの要部を示す回転軸に沿った断面図である。
【図２】図１中の気室壁を構成する板状部材の、（イ）は平面図であり、（ロ）は円弧状の両端部を接合した状態を示す斜視図であり、（ハ）は、（ロ）中のＢ−Ｂ線に沿う断面図である。
【図３】図１に示すＡ−Ａ線に沿う軸直角断面図である。
【図４】本発明の他の好適実施形態に係るリムホイールの要部を示す回転軸に沿った断面図である。
【図５】図４中の気室壁を構成する板状部材の、（イ）は円弧状の両端部を接合した状態を示す斜視図であり、（ロ）は、（イ）中のＣ−Ｃ線に沿う断面図である。
【符号の説明】
１　リムホイール
２　リム
３，１３　気室壁
４　ビードシート
４Ａ　段部
５　隔壁
６　副気室
７　ウエル部
８　連通部
９　板状部材
１０　タイヤ
１１　タイヤ主気室[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a rim wheel for a vehicle to which a tire is mounted, and more specifically, suppresses vibration transmitted to the vehicle while securing high steering stability, realizes an improvement in ride comfort, a reduction in vehicle interior noise, and the like. The present invention relates to a manufacturing method for a rim wheel capable of performing high productivity and reducing a cause of a failure due to a welding defect or the like.
[0002]
[Prior art]
2. Description of the Related Art In recent years, advanced functions have been promoted, especially in the area of luxury vehicles, in which driving stability, riding comfort, and quietness of a vehicle are both achieved at a high level. Under such demands, in order to suppress tire cavity resonance sound, which is a major factor in vehicle interior noise, a secondary air chamber is provided in the rim wheel and Helmholtz resonance is adjusted by adjusting the dimensions of the communication hole with the secondary air chamber. Techniques for operating as a sound absorber are disclosed in Patent Documents 1 to 5 and the like.
[0003]
However, the technology described in the above-mentioned known document utilizing the action of the Helmholtz resonance sound absorber does not necessarily have a sufficient improvement effect or has some problems, and has not yet been put to practical use. Was the current situation.
[0004]
Under such circumstances, a plurality of sub-air chambers formed between the rim and the plurality of lid members arranged radially outward of the rim and divided by a plurality of side walls provided at intervals in the circumferential direction. By forming a Helmholtz resonance sound absorber with a communication part that communicates the auxiliary air chamber and the tire main air chamber, the ride comfort and quietness, which are great performance requirements of automobiles, are significantly improved, and It has been found that a rim wheel can be obtained, and a patent application was previously filed by the present applicant (Patent Document 6).
[0005]
[Patent Document 1]
Published Japanese Utility Model Application No. 1-39103 [Patent Document 2]
Published Japanese Utility Model Application No. Hei 1-90601 [Patent Document 3]
JP-A-1-115701 [Patent Document 4]
JP-A-1-115702 [Patent Document 5]
European Patent No. 0936083 [Patent Document 6]
JP 2002-79802 A
[Problems to be solved by the invention]
The rim wheel described in Patent Literature 6 is significantly superior in quietness, steering stability, and vibration riding comfort as compared with the conventional technology that constitutes the Helmholtz resonance sound absorber, and can be sufficiently put to practical use. It is. Therefore, there is a demand for reliably manufacturing a rim wheel having a sub air chamber as disclosed in the publication with high productivity.
[0007]
In view of the above, an object of the present invention is to respond to such a demand, suppress vibration transmitted to a vehicle while ensuring high steering stability, improve riding comfort, reduce in-vehicle noise, and the like. It is an object of the present invention to provide a method capable of manufacturing a rim wheel with reduced causes of failure with high productivity.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventor has found that the above configuration can achieve the above object, and has completed the present invention. That is, the present invention is as described below.
[0009]
<1> Formed by a rim and an air chamber wall formed annularly in the circumferential direction across the outer peripheral surface of the rim and one of the bead seats, and provided at appropriate intervals in the circumferential direction. A plurality of sub-air chambers divided by a plurality of partition walls are provided, and the air chamber wall has a communication part for communicating the tire main air chamber and the sub-air chamber, and the sub-air chamber and the communication part are used by Helmholtz. In manufacturing the rim wheel that constitutes the resonance sound absorber,
(I) a bending step of bending a planar substantially arc-shaped plate member into a predetermined shape;
(II) a fixing step of fixing the plate member between the outer peripheral surface of the rim and one of the bead sheets;
A method for manufacturing a rim wheel.
[0010]
<2> The method for manufacturing a rim wheel according to the above <1>, wherein the partition is integrally formed with the rim during casting of the rim wheel.
[0011]
<3> The method for manufacturing a rim wheel according to <1>, wherein the partition is welded or bonded to an outer peripheral surface of the rim prior to formation of the air chamber wall.
[0012]
<4> The method for manufacturing a rim wheel according to any one of <1> to <3>, wherein the at least three sub air chambers are provided.
[0013]
<5> The method for manufacturing a rim wheel according to any one of <1> to <4>, wherein a communication portion is formed in the air chamber wall at a substantially central portion of a circumferential length between the partition walls. It is a manufacturing method.
[0014]
In the rim wheel manufactured by the method of the present invention of <1>, the formed sub air chamber has a communication portion with the tire main air chamber and functions as a Helmholtz resonance sound absorber. The dimensions such as the volume of the auxiliary air chamber, the cross-sectional area and the length of the communication part are calculated by the following formulas

f ₀ : resonance frequency (Hz)
V: Secondary air chamber volume (cm ³ )
S: total cross-sectional area of communication part (cm ² )
L: Length of communication part (cm)
N: Number of communicating parts / air chamber R: Wheel diameter (inch)
, Effective cavity resonance reduction can be achieved. That is, first, the rim diameter is determined, and thereafter, the auxiliary air chamber volume V (cm ³ ), the total cross-sectional area S (cm ² ) of the communication portion, the length L (cm) of the communication portion, and the number N of the communication portions are determined. A rim wheel capable of effectively reducing tire cavity resonance is obtained. Here, the left term of the above equation represents the Helmholtz resonance frequency. The cavity resonance frequency in the tire main chamber is determined by the circumferential length of the tire and the rim, and this frequency becomes higher in a small diameter tire and becomes lower in a large diameter tire. The right term in the above equation is a calculation of an optimum set frequency range according to the tire size and the rim diameter.
[0015]
In addition, as a method of creating the sub air chamber, the side wall and the upper wall constituting the sub air chamber have been separated and fixed to the outer peripheral surface of the rim and the bead sheet by welding or the like, respectively. In the manufacturing method of the present invention described in the above <1>, the side and upper walls of the auxiliary air chamber are formed by one air chamber wall. As a result, the number of sticking points can be reduced, and the joining work such as welding can be significantly reduced compared to the conventional method, thereby preventing failure due to welding defects such as peeling of a welded portion. In addition, productivity can be improved favorably by reducing the number of steps.
[0016]
In the manufacturing method of the present invention <2>, since the partition is formed at the time of casting the rim wheel, a step for installing the partition can be omitted, and it is possible to reduce a case where the partition is installed on the rim outer peripheral surface by welding or the like. As a result, occurrence of a failure due to a welding defect or the like can be further reduced.
[0017]
In addition, even when the partition is formed by welding or the like according to the manufacturing method of the present invention of the above <3>, an effective reduction of cavity resonance sound is achieved in accordance with the above equation, as in the case of the manufacturing method of the above <2>. be able to.
[0018]
In the manufacturing method of the present invention <4>, since the auxiliary air chamber is formed in three or more air chambers in the circumferential direction by the three or more closed partition walls, the tire cavity resonance sound can be prevented without delay of resonance sound absorption. Can be effectively reduced. Preferably, the number of auxiliary air chambers is four or more, more preferably five or more.
[0019]
By piercing the communicating portion by the manufacturing method of the present invention of <5>, it is possible to achieve effective reduction of cavity resonance sound according to the above equation. The number of communicating portions is not limited to one for each sub-air chamber, and the resonance frequency setting can be changed only by adjusting the diameter and number of the communicating portions. The diameter may be appropriately determined according to the tire size.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a sectional perspective view showing a state in which a tire 10 is mounted on a rim 2 of a rim wheel 1 according to a preferred embodiment of the present invention. As shown in the figure, in the rim wheel 1, when the tire 10 is mounted on the rim 2 of the rim wheel 1, a sealed main air chamber 11 is formed between the tire 10 and the rim 2. In the present invention, the Helmholtz resonance sound absorber is constituted by providing the sub air chamber 6 communicating with the main air chamber 11. The manufacturing method of the present invention mainly relates to the step of forming the auxiliary air chamber 6 constituting the Helmholtz resonance sound absorber.
[0021]
As shown in the figure, the sub-air chamber 6 includes a rim 2 and an air chamber wall 3 formed in a circumferential direction annularly across the outer peripheral surface and one of the bead seats 4 (in the direction of the arrow IN). As shown in FIG. 3 which is a circumferential cross-sectional view along the line AA in the figure, the partition is divided by a plurality of partition walls 5 provided at appropriate intervals in the circumferential direction. A communication portion 8 as shown in FIG. 3 is formed in the air chamber wall 3 so that the tire main air chamber 11 and the sub air chamber 6 communicate with each other to form a Helmholtz resonance sound absorber. .
[0022]
In the present invention, when forming the air chamber wall 3 constituting the sub-air chamber 6, a plate-like member 9 having a substantially circular arc shape as shown in FIG. 2A is used, and the plate member 9 is bent into a predetermined shape. After processing (bending step (I)), the rim 2 is fixed between the outer peripheral surface of the rim 2 and one of the bead sheets 4 (fixing step (II)). This makes it possible to reduce the number of fixing points and the number of steps as compared with the conventional method of forming the sub-air chamber 6 by using the side and upper walls of the sub-air chamber as separate members. Failure can be prevented well and productivity can be improved. As for the fixing portion on the bead sheet 4 side, for example, as shown in FIG. 1, a step portion 4A having an appropriate height and shape may be provided, and the step portion 4A may be fixed to the plate member 9.
[0023]
FIG. 2B shows a state where the substantially arc-shaped ends of the plate-shaped member 9 after bending are fixed together, and FIG. 2C is BB in FIG. 2B. FIG. 3 is a sectional view taken along a central axis direction along a line. As shown in the figure, a ring-shaped member is formed by joining both ends of a plate-like member 9 having a substantially circular arc shape by welding or bonding. Therefore, in the present invention, such a plate-like member 9 is wound across the outer peripheral surface of the rim 2 and one bead sheet 4 along the circumferential direction of the rim 2, and both end portions thereof are shown in FIG. The air chamber wall 3 as shown in FIG. 1 can be formed by joining as shown in FIG.
[0024]
In addition, the air chamber wall may have, for example, a shape as shown in FIG. The air chamber wall 13 shown in FIG. 4 is also appropriately bent by using a plate-like member 9 having a substantially circular arc shape as shown in FIG. 1 can be formed in the same manner as the air chamber wall 3 in FIG.
[0025]
The plate-like member 9 is appropriately dimensioned (diameter of circular arc, circumferential length, width, etc.) so that the desired volume of the sub-air chamber 6 can be formed according to the diameter of the rim 2 and the height of the bead seat 4. What is necessary is just to form. As the material, a commonly used material can be appropriately selected and used. For example, it is preferable to use an aluminum material which is lightweight and has excellent handleability.
[0026]
The fixation between the air chamber wall 3 and the outer peripheral surface of the rim 2 and the bead seat 4 can be performed by welding, whereby the highly airtight auxiliary air chamber 6 is obtained. In addition, as a method other than welding, fixing can be performed by adhesion. As the adhesive used for bonding, for example, a rubber-based adhesive (for example, an elastic epoxy adhesive Bond MOS7 (trade name) manufactured by Konishi Co., Ltd., an elastic adhesive PM series (trade name) manufactured by Cemedine Co., Ltd.), or the like is used. Can be used.
[0027]
It is preferable that the partition walls 5 constituting the adjacent side walls of the sub air chambers 6 are formed integrally with the rim 2 during rim wheel casting. In this case, since it is not necessary to perform a step of newly forming the partition wall 5 after casting the rim wheel, it is possible to further reduce the number of fixing points and the number of steps, and to further contribute to improving productivity and preventing failure. . As a casting method at this time, a conventional method can be used as it is.
[0028]
If the partition 5 is not integrally formed with the rim 2, it is necessary to fix a separately prepared partition 5 to the outer peripheral surface of the rim 2 by welding or bonding before forming the air chamber wall 3. Even in this case, the effects of improving the productivity and preventing the failure by the air chamber wall 3 according to the present invention can be obtained. The same adhesive as used in the case of the air chamber wall 3 can be used as the adhesive used when the partition walls 5 are fixed by bonding.
[0029]
In addition, in order to obtain the airtightness of each sub air chamber 6, it is necessary to fix between the radial outer end of the partition wall 5 that divides the sub air chamber 6 and the air chamber wall 3. Adhesion between the partition 5 and the air chamber wall 3 can also be suitably performed by adhesion.
[0030]
Here, in the illustrated preferred example, a concave well portion 7 for dropping a tire bead portion when the tire is mounted is formed on the rim wheel main body. The bottom of the well 7 is located radially inward of the bead seat 4 in the tire radial direction.
[0031]
The well portion 7 may have an axially wide structure or a radially inner deep structure as appropriate. Here, a structure that is deeper in the radial direction means that the diameter difference between the bead portion and the wheel base portion is large.If there is sufficient brake space, the diameter difference is reduced by reducing the diameter of the wheel base portion. The diameter can be increased, but if there is not enough room, the diameter difference can be increased by increasing the diameter of the bead portion and decreasing the tire height (making the tire outer diameter the same), that is, the so-called inch-up method.
[0032]
There is no substantial restriction on making the well portion 7 wide in the axial direction. Therefore, it is possible to obtain a desired volume of the auxiliary air chamber 6 while widening the well portion 7. From the viewpoint that a large volume can be ensured, it is preferable to be formed deep inside in the radial direction.
[0033]
That is, when forming the sub air chamber 6 having a desired volume while forming the well portion 7 on the rim 2, the fixing portion of the air chamber wall 3 to the rim 2 is disposed substantially at the center of the rim 2 in the axial direction. Is preferred. This allows the tire to be assembled to the rim as before.
[0034]
As shown in FIG. 3, the communication portion 8 is provided on the air chamber wall 3 for each sub air chamber 6 in order to establish communication between the tire main air chamber 11 and the sub air chamber 6. The communication part 8 can be formed after the air chamber wall 3 is fixed to the outer peripheral surface of the rim 2 and the bead seat 4. It is preferable to provide them. Although the position of the communication portion 8 is not particularly limited, in the preferred example shown in the drawing, from the viewpoint that it is preferable to achieve effective reduction of the cavity resonance sound, a substantially central portion of the circumferential length of the sub air chamber 6 is preferred. That is, a communication portion 8 is formed in the air chamber wall 3 at a substantially central portion of the circumferential length between the adjacent partition walls 5.
[0035]
In the preferred embodiment shown in FIG. 3, by providing five partitions 9 at equal intervals in the circumferential direction, the partition 9 is shared between adjacent sub-air chambers, and five sub-air chambers 6 are arranged. Have been. The five sub-air chambers 6 communicate with the tire main air chamber 11 through the communication portions 8 provided one by one, and in the present embodiment, these sub-air chambers 6 and the communication portion 8 are counted. Five Helmholtz resonance sound absorbers are configured.
[0036]
Here, when the tire 10 is assembled on the rim wheel 1, the setting of each part is performed so as to satisfy the above expression. The cavity resonance frequency in the tire main air chamber is determined by the circumference of the tire and the rim. In a normal passenger car tire, the cavity resonance frequency is around 250 Hz. This frequency is high for a mini vehicle tire and low for a large truck tire.
[0037]
The total internal volume of the sub air chamber 6 with respect to one rim wheel 1 is preferably 2% or more and 25% or less of the volume of the tire main air chamber 11, and more preferably 3% or more and 15% or less.
[0038]
When the tire (195 / 55R15) 10 is mounted on the rim wheel (6JJ15) 1 of the present embodiment, the volume of the tire main air chamber 11 is about 22000 cm ³ , and the total volume of the five sub air chambers 6 is 1500 cm ³ ( 300 cm ³ × 5), and the total volume of the five sub-air chambers 6 is 6.9% of the total volume of the tire main air chamber 11.
[0039]
【Example】
Hereinafter, the present invention will be described based on examples.
A prototype of a conventional combination product of a rim wheel and a tire (comparative example (control product)) and a combination product of a rim wheel and a tire manufactured according to the present invention (example) were tested for a road noise evaluation drum test. .
[0040]
Control product: a normal JJ / 55R15 size tire for a passenger car mounted on a 6JJ15 normal aluminum wheel.
[0041]
Example: A passenger car tire similar to a control product was mounted on a rim wheel (five partition walls) having a structure shown in FIGS. 1 and 3 manufactured using an aluminum plate member 9 as shown in FIG. Things.
[0042]
The total volume of the auxiliary air chamber is 1500 cm ³ (6.9% of the tire main air chamber), while the diameter of the communication part is 0.8 cm and the length of the communication part is about 22,000 cm ³ of the volume of the tire main air chamber. 0.2 cm.
[0043]
The resonance frequencies of the example and the comparative example were each set to about 250 Hz according to the above equation. The road noise drum has a diameter of 3 m and has asphalt on the surface imitating a general road shape. When the tire was pressed against the drum with a load of 3920 N (400 kgf) and was run at a speed of 60 km / h, the axial force of the drum in each direction was measured and frequency analysis was performed.
[0044]
As a result of frequency analysis of the axial force in the vertical direction, the cavity resonance peak was reduced by about 8.7 dB in the example as compared with the comparative example.
[0045]
Further, the tires of the example and the comparative example were mounted on a passenger car, and two test drivers ran a real vehicle on a test course to perform a steering stability test and a vibration riding comfort test.
[0046]
Driving, braking, steering wheel responsiveness, and controllability during maneuvering are comprehensively evaluated for steering stability, and for vibration riding comfort tests, vibration on good roads, vibration on bad roads, and bumps on special roads Vibration during running and noise in the vehicle were comprehensively evaluated, and the tire of the example was evaluated by an index when the control (comparative example) was set to 100. The larger the index value, the better. As a result, the steering stability was 110, the vibration comfort was 115, and the noise in the vehicle was 155.
[0047]
【The invention's effect】
As described above, according to the present invention, it is possible to suppress vibration transmitted to a vehicle while securing high steering stability, to improve ride comfort, reduce vehicle interior noise, and the like. A rim wheel with reduced causes of failure can be manufactured with high productivity.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view along a rotation axis showing a main part of a rim wheel according to a preferred embodiment of the present invention.
2A is a plan view of a plate-like member constituting an air chamber wall in FIG. 1, FIG. 2B is a perspective view showing a state in which both ends of an arc shape are joined, and FIG. () Is a cross-sectional view along line BB in (b).
FIG. 3 is a sectional view taken along a line AA shown in FIG.
FIG. 4 is a cross-sectional view along a rotation axis showing a main part of a rim wheel according to another preferred embodiment of the present invention.
5A is a perspective view of the plate-shaped member constituting the air chamber wall in FIG. 4, in which FIG. 5A is a perspective view showing a state in which arcuate ends are joined, and FIG. 5B is a perspective view of C in FIG. It is sectional drawing which follows the -C line.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 rim wheel 2 rim 3, 13 air chamber wall 4 bead seat 4A step 5 partition wall 6 sub air chamber 7 well section 8 communication section 9 plate member 10 tire 11 tire main air chamber

Claims (5)

A plurality of partition walls formed by a rim and an air chamber wall formed annularly in the circumferential direction so as to straddle between the outer peripheral surface of the rim and one of the bead seats and provided at appropriate intervals in the circumferential direction A plurality of sub air chambers divided by the air chamber wall, the air chamber wall has a communication portion for communicating the tire main air chamber and the sub air chamber, and the Helmholtz resonance sound absorber is provided between the sub air chamber and the communication portion. In manufacturing the rim wheel that constitutes
(I) a bending step of bending a planar substantially arc-shaped plate member into a predetermined shape;
(II) a fixing step of fixing the plate member between the outer peripheral surface of the rim and one of the bead sheets;
A method for manufacturing a rim wheel, wherein the air chamber wall is formed by: The method for manufacturing a rim wheel according to claim 1, wherein the partition is formed integrally with the rim during rim wheel casting. The method for manufacturing a rim wheel according to claim 1, wherein the partition is welded or bonded to an outer peripheral surface of the rim prior to forming the air chamber wall. The method for manufacturing a rim wheel according to claim 1, wherein three or more sub air chambers are provided. The method for manufacturing a rim wheel according to any one of claims 1 to 4, wherein a communication portion is formed in the air chamber wall at a substantially central portion of a circumferential length between the partition walls.

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