JP3999536B2

JP3999536B2 - Suspension device

Info

Publication number: JP3999536B2
Application number: JP2002062838A
Authority: JP
Inventors: 裕章川崎
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2002-03-08
Filing date: 2002-03-08
Publication date: 2007-10-31
Anticipated expiration: 2022-03-08
Also published as: JP2003260916A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車の懸架装置に係り、特に車高調整式の懸架装置に関する。
【０００２】
【従来の技術】
本発明者は既に特願２００１−３４７８３７号に於て、緩衝装置のロッドと車体側とをラバーブッシュ（防振ゴム）を介して連結し、かつ、緩衝装置のロッドと、エアスプリングのロッド挿入用孔部との間に、隙間を形成し、ロッドがエアスプリングの軸心に対して偏心できる構造のものを、提案している。
【０００３】
即ち、上述の偏心できる構造とは、上記ラバーブッシュを採用し、及び、ロッド外径に対して、エアスプリングのロッド挿入用孔部の内径を、１mm〜５mm大きくした（言い換えると隙間を 0.5mm〜 2.5mmに設定した）構造である。
【０００４】
ストラット式サスペンションでは走行中にステアリングを切った際、緩衝装置のロッドがアッパーマウント（車体側への連結部）を中心として振れ、エアスプリングの軸心に対して偏心するが、このとき、上記隙間によってロッドがロッド挿入用孔部に干渉するのを防止する構造である。
【０００５】
【発明が解決しようとする課題】
しかしながら、車種によっては、上記ロッドの上端のラバーブッシュと車体側との連結部位（いわゆるアッパーマウント）に於て、ロッド軸心と車体接合面とが直交していない場合があり、あるいは、同一車種でも製造ばらつき等によって直交度が悪い場合があり、ステアリングを切っていない状態でも、既にロッドがエアスプリング軸心に対して偏心し、上述の隙間が２mm以下では、走行中にロッドがエアスプリングのロッド挿入孔と干渉してしまうことが、判明した。
【０００６】
さらに、ストラット式サスペンションでは、ストラット軸心（ロッドの軸心）と、上記アッパーマウントの中心点とタイヤ接地点とを結んだ荷重入力軸心が、ずれているため、緩衝装置（ロッド）に曲げモーメントが作用する。この曲げモーメントが付加されることにより、一層、ロッドと挿入孔の上記干渉が発生しやすくなることが、判明した。
【０００７】
そこで、上述の隙間を、例えば２mm以上にしようとすると、通常市販されているエアーシールパッキンでは、張り代が小さく、密封性が著しく低下するので、特別に張り代の大きいパッキンを独自に設計する必要がある。
【０００８】
走行中の摺動や振動、偏心を考慮しつつ、かつ、高い密封性のパッキンを設計・開発することは、至難である。
そこで、本発明は、ストラット（ロッド）に曲げモーメントが働いても、ロッドと、エアスプリングのロッド挿入孔と軸心がずれないようにすることを目的とし、また、ストラット軸心と車体側接合面との角度が直交していなくても、同様に軸心がずれないようにすることを他の目的とする。そして、エアースプリング用のパッキンとして標準的な通常のパッキンでも十分使用可能とすることで開発費低減と金型費用の節減を図ることを別の目的とする。
【０００９】
【課題を解決するための手段】
上記目的を達成するため、本発明は、緩衝装置とコイルスプリングとエアスプリングとを備え、上記コイルスプリングと上記エアスプリングとを直列的に配設し、上記緩衝装置のロッドが該エアスプリングを貫通して、該緩衝装置が車体側と車軸側とを連結した懸架装置に於て、上記ロッドに往復動自在に摺動外嵌する偏心防止用ガイド部材を、上記エアスプリングに内設し、さらに、一中心点廻りに首振り可能でかつ軸心廻りに回転自在な軸受機構を介して、上記緩衝装置を車体側に連結し、さらに、上記エアスプリングの内圧を、上記偏心防止用ガイド部材を挟んで上下各々に配設されて上記ロッドに接するシール材にて、密封するように構成し、かつ、上記エアスプリングは、上壁部材と下壁部材と両者間に介設された弾性膜とを、備え、上記上壁部材はフランジ部と該フランジ部から下方突出状の円筒部を備えて軸心方向のロッド挿通用段付孔を有し、該円筒部は該段付孔に上記シール材を嵌込む凹溝を有し、さらに、上記下壁部材はフランジ部と該フランジ部から上方突出状の円筒部を備えて軸心孔を有し、さらに、上記偏心防止用ガイド部材は滑り軸受けから成ると共に、該滑り軸受け及び上記シール材を、上記円筒部に於て上記軸心孔に嵌着し、上記下壁部材の上記円筒部を上記弾性膜内へ突入し、上記下壁部材の上記円筒部の上端外周は小径に切欠形成され、上記上壁部材の上記円筒部の下面に内方開口端を開口したエアー流路を上記上壁部材の円筒部から上記フランジ部に渡って貫設して、上記内方開口端を、下壁部材の上記円筒部の上記切欠形成された上端外周に対応させて、上記エアスプリングに内圧が無い無圧状態下で、上記上壁部材の上記円筒部の下面と、上記下壁部材の上記円筒部の上面とが、相互に当接するように構成したものである。
また、一中心点廻りに首振り自在でかつ軸心廻りに回転自在な上記軸受機構は、防振ゴム部と、該防振ゴム部の軸心孔部に嵌着されたボールベアリング又はスラストベアリングから成る回転軸受部とから、構成されている。
【００１０】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づき詳説する。
【００１１】
図１〜図３は本発明に係る自動車の車輪懸架装置の実施の一形態を示したものであり、この懸架装置Ａは、緩衝装置（ダンパー）２とコイルスプリング３とエアスプリング４とを備え、コイルスプリング３の上部に、直列的にエアスプリング４を配設している。そして、緩衝装置２のロッド２ａがエアスプリング４を貫通して、緩衝装置２が、車体側Ｂと車軸側Ｓとを連結している。つまり、本懸架装置Ａは、自動車の車体側Ｂと車軸側Ｓとの間に装着される。ここで、「直列的」とは、車体側Ｂと車軸側Ｓの間の力の伝達が、一方のみを介して伝達されることが無く、必ず両者を介して伝達されるような配置を言う。
【００１２】
さらに具体的に説明すれば、緩衝装置２のストラット本体２ｂの下部は車軸側Ｓ───車軸自体又はリンク若しくは取付具───に取付けられ、かつ、緩衝装置２のロッド２ａの上部は、一中心点Ｏ廻りに首振り可能でかつ軸心Ｌ廻りに回転自在な軸受機構Ｃを介して、車体側Ｂに連結される。このように、ストラットアッパーマウントに於て一中心点Ｏを支点に振れると共にスラスト荷重を受けて軸心Ｌ廻りに回転可能な軸受機構Ｃが用いられている。
【００１３】
この軸受機構Ｃとしては、防振ゴム部41と、その軸心孔部42に嵌着された（スラスト荷重を受けても回転可能な）ボールベアリング又はスラストベアリングの回転軸受部43とから、構成されている。さらに具体的には、車体側Ｂの取付板部７の取付孔部７ａを下方から閉じるように当接する板部材41ａと、この板部材41ａの中央膨出部の下面に一体的に付設されたゴム材41ｂで、防振ゴム部41が、構成されている。この板部材41ａには雄ネジ部９…が予め上方突出状に設けられていて、取付板部７の孔部に、この雄ネジ部９を挿入して、ナット10にて螺着することで、上記防振ゴム部41を、車体側Ｂへ固着している。
【００１４】
防振ゴム部41のゴム材41ｂに、回転軸受部43が嵌着され、スペーサ部材26等を介して、ナット27にて、ロッド２ａの上端と回転軸受部43とは、連結される。
特に、防振ゴム部41の板部材41ａの外周縁及びラジアル方向中間部位は、エアスプリング４の上壁部材16上面との間に、（従来のラバーブッシュにおける）スラスト部材又は弾性部材等の介装材が、省略されており、従って、軸受部43の中心点Ｏを支点（中心）として、軸受機構Ｃが首振り（揺動）が行い得る。
【００１５】
コイルスプリング３は、緩衝装置（ダンパー）２の中間部位を包囲するように配設される。ストラット本体２ｂに外鍔状に突設された受け鍔部14に、コイルスプリング３の下端が当接乃至取付けられ、かつ、コイルスプリング３の上端は、エアスプリング４の下壁部材15に当接乃至取付けられる。また、図４に示した他の実施の形態に於ては、図１と比較して、同一符号は同一の構成である。主として相違する点は軸受機構Ｃに関してであり、この軸受機構Ｃとしては、図４ではピローボールジョイント13を用いた場合を例示する。つまり、車体側Ｂの取付板部７の取付孔部７ａを下方から閉じるように当接する取付片８には雄ネジ部９…が上方へ予め突設されており、取付板部７に形成した孔部へこの雄ネジ部９を挿入して上方からナット10にて螺着して、取付片８を固着する。
【００１６】
この取付片８が、ピローボールジョイント13の雌部材（外殻体）11に外鍔状に固着されていると共に、ロッド２ａの上端には雄側球面体12が固着され、ロッド２ａの軸心Ｌは、ピローボールジョイント13の中心点Ｏ廻りに首振り自在である。このように軸受機構Ｃが球面軸受の場合を図４では示している。
【００１７】
以下、図１〜図３、及び、図４について、合わせて説明する。前記エアスプリング４は、上壁部材16と上記下壁部材15と、両者間に介設された弾性膜17とを、備えている。即ち、ビア樽型等の（ゴム製の）弾性膜17の上開口部・下開口部を、各々、上壁部材16・下壁部材15にて、塞ぐように挟んで、組立てられている。
【００１８】
上壁部材16は、図例では、小径孔部18と大径孔部19から成る段付孔20を軸心に有する円盤型であり、かつ、段付孔20の大径孔部19には、シール材21を嵌込む凹溝22が形成されている。また、上壁部材16は、上記段付孔20を有する円筒部23と、この円筒部23の上半部から突出状に連設されたフランジ部24と、を備え、円筒部23がフランジ部24から下方へ突出している部位は、弾性膜17内へ突入し、かつ、弾性膜17の上方外面はフランジ部24に当接する。
【００１９】
上壁部材16には、エアー流路25が貫設されていて、弾性膜17の内部と、外側（大気側）の図示省略のエアー配管とを、連通連結する。この上壁部材16は、スペーサ部材26を介して、回転軸受部43（図１参照）又は球面体12（図４参照）に軸心方向の力を伝達するように、設けられている。言い換えると、段付孔20の段付面と、上方のナット27によって、上壁部材16はスペーサ26と回転軸受部43（図１参照）又は球面体12（図４参照）と共に、締付けられて、ロッド２ａに固着されている。このように、エアスプリング４の上壁部材16はロッド２ａに固定される。
【００２０】
これに対して、下壁部材15はロッド２ａに対して、その軸心Ｌに沿って往復動自在である。具体的にその下壁部材15の構造を説明すると、ロッド２ａに往復動自在に直接に摺接する偏心防止用ガイド部材30を嵌着する上方孔部28と、シール材29を嵌め込む凹溝31を有する下方孔部32とから成る軸心孔33を有する円盤型である。
【００２１】
34はＣ型止め輪を示し、偏心防止用ガイド部材30としては、例えば、低摩擦・耐摩耗性の金属又はプラスチックから成る滑り軸受けが好適であって、この滑り軸受けを、段付き部35に当接するまで上方孔部28に上方から嵌入して、Ｃ型止め輪34にて抜け止めする。また、シール材（パッキン）29としては、図１，図４ではＵ字状パッキンを例示し、図２では、ダストシール舌片部29ａを有するＵ字状パッキンを例示するが、いずれを選択するも自由であることを示す。
【００２２】
また、下壁部材15は、上記軸心孔33を有する円筒部36と、この円筒部36の下端部から突出状に連設されたフランジ部37と、を備えている。円筒部36がフランジ部37から上方へ突出している部位は、弾性膜17内へ突入し、かつ、弾性膜17の下方外面はフランジ部37に当接する。円筒部36の上端外周はやや小径となるように切欠形成され、図１又は図４のように、上壁部材16の円筒部23に当接した状態に於て、エアー流路25の内方開口端25ａが閉じることを防止している。また、外鍔状フランジ部37の下面には、コイルスプリング３の上端を嵌着状に受ける円環状突条部38が突出状に形成されている。このように、下壁部材15はコイルスプリング３の弾発力を直接に受ける部材である。なお、下壁部材15の下方に於て、ロッド２ａにはバンプラバー39が外嵌状に取付けられている。
【００２３】
この下壁部材15の軸心は、ロッド２ａの軸心Ｌに対して、常時一致するように、ロッド２ａに往復動自在に摺動外嵌する前記偏心防止用ガイド部材30が、機能（作用）する。言い換えると、エアスプリング４の軸心とロッド２ａの軸心Ｌとを、常に一致させるためのすべり軸受等の偏心防止用ガイド部材30を、エアスプリング４に内設している。
【００２４】
また、図１又は図４と図２から明らかなように、上記ガイド部材30を挟んで上下各々に配設されたシール材（パッキン）21, 29は、ロッド２ａに摺接して、エアスプリング４の内圧を密封する。
【００２５】
エアスプリング４の内部へ、エアー流路25を介して加圧エアを供給・排出する制御により、エアスプリング４の弾性膜17を伸長縮小（膨張縮小）させて、車高を調整することができる。
【００２６】
本発明は上述のように、車体側Ｂと車軸側Ｓとを、軸心Ｌに沿って配設した緩衝装置（ダンパー）２にて上下に連結し、かつ、エアスプリング４は、コイルスプリング３の上部に、緩衝装置２のロッド２ａを包囲状に配設され、さらに、エアスプリング４の内部には、偏心防止用ガイド部材30が内設され、ストラット軸（ダンパー２）に、図３に矢印Ｆで示すような外力が作用して、それに伴って曲げモーメントが働いても、ロッド２ａの軸心Ｌは、エアスプリング４の軸心に対して、偏心しない構造となっている。
【００２７】
また、図１又は図４に示すように、エアスプリング４に内圧が無いとき、エアスプリング４の内部で、上壁部材16と下壁部材15とが相互に当接し、車体荷重を受持ち、弾性膜17に荷重が掛からないように構成されている。
【００２８】
なお、図示省略するが、コンプレッサからエアタンク，電磁弁，配管等を介して、エアー流路25へ加圧エアが供給される。その操作は、運転席付近のスイッチにて、電磁弁を開閉させることにより、エアスプリング４への加圧エアの出し入れを行う。また、コンプレッサの電源は、バッテリ等を用いる。
【００２９】
車両（自動車）の見栄えや走行性能を重視するユーザーの場合、通常、エアスプリング４に加圧エアを充填せず、車高が低い状態で走行し、段差等がある場合に、エアスプリング４に加圧エアを充填して車高を上昇させて、段差等を乗り越える等の使用方法がとられる。
【００３０】
次に、ステップワゴンのフロントに図４と図３に示すように、本発明に係る懸架装置Ａを取付けて、本発明実施例とする。このとき、偏心防止用ガイド部材30として、エヌティエヌ株式会社製の精密樹脂滑り軸受けを使用すると共に、シール材21, 29としては一般的なエアー用Ｕパッキンを使用した。これに対し、従来例として、特願２００１−３４７８３７号の発明のように、アッパーマウントにラバーブッシュタイプであって、緩衝装置のロッドとエアスプリングとの隙間を 1.5mmとした懸架装置を、図３と同様の部位に取付けたものを採用して、比較テストを実施した。そのテストの結果、従来例では、ステアリングを切った状態で、エアスプリング内にエアを出し入れし車高を上げ下げしたところ、エアスプリングがスムーズに伸長しにくいことがあった。テスト後、分解してみると、エアスプリングの下壁部材の孔部内面とロッドに傷が付いていた。
【００３１】
これに対し、本発明の実施例では、ステアリングを切った状態も、エアスプリング４がスムーズに伸長することができ、ロッド２ａには全く傷がついていなかった。
【００３２】
図３に示すように、ストラット式サスペンションでは、ストラット軸心Ｌと、タイヤ接地点Ｇとストラットアッパマウント点（中心点）Ｏとを結んだ直線Ｌｇ（荷重入力軸）とが、ずれているため、曲げモーメントがストラット軸心Ｌに作用する。この際、従来例では、アッパーマウントにラバーブッシュを採用しているので、ロッドとエアスプリングの孔部との隙間が 1.5mm程度ではロッドとエアスプリングの孔部とが干渉を発生するため、上述のロッドに傷が生じ、かつ、スムーズに伸長しなくなったと考えられる。本発明は、上述の構成により、コイルスプリング３とエアスプリング４を直列的に配置したため、全体のばね定数を小さくでき、地面等からの衝撃を和らげて乗り心地を向上できる。かつ、エアスプリング４の内圧を変えることで、（ばね定数を変化させて）様々な乗り心地を楽しみ得る。
【００３３】
【発明の効果】
本発明は、上述の構成により次のような著大な効果を奏する。
ステアリングを切った状態等にあっても、緩衝装置２のロッド２ａはエアスプリング４の孔部に対して、常時軸心が一致し、円滑に伸縮できる。かつ、シール材21, 29として、大きな張り代の特殊なものを必要とせず、安価かつ入手容易な汎用パッキンを適用可能となる。
【００３４】
車体側Ｂの接合面に対してロッド軸心Ｌが直交状でない場合でも、ロッド軸心Ｌがエアスプリング４の（孔部の）軸心に対して偏心せず、一層、スムーズにエアスプリング４が伸長・短縮できる。
【００３５】
また、図３に示したように、ストラット式サスペンションであって、ストラット軸（軸心Ｌ）と荷重入力軸Ｌｇとが、ずれて曲げモーメントが懸架装置に働いたとしても、基本的な偏心量が微小に抑制できるので、エアスプリング４の伸縮に支障がなく、スムーズとなる。
【００３６】
シール材21, 29として一般市販用のパッキンを使用可能であり、かつ、密封性（シール性）も長期間安定して確保できる。
【図面の簡単な説明】
【図１】本発明の実施の一形態を示す一部断面要部説明図である。
【図２】要部拡大図である。
【図３】使用方法の一例を説明する正面図である。
【図４】他の実施の形態を示す一部断面要部説明図である。
【符号の説明】
２緩衝装置
３コイルスプリング
４エアスプリング
15 下壁部材
16 上壁部材
17 弾性膜
20 段付孔
21 シール材
22 凹溝
23 円筒部
24 フランジ部
29 シール材
30 偏心防止用ガイド部材
33 軸心孔
36 円筒部
37 フランジ部
41 防振ゴム部
42 軸心孔部
43 回転軸受部
Ｂ車体側
Ｃ軸受機構
Ｌ軸心
Ｏ中心点
Ｓ車軸側[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle suspension system, and more particularly to a vehicle height adjustment type suspension system.
[0002]
[Prior art]
In the Japanese Patent Application No. 2001-347837, the inventor has already connected the rod of the shock absorber and the vehicle body side via a rubber bush (vibration isolation rubber), and inserted the rod of the shock absorber and the rod of the air spring. A structure has been proposed in which a gap is formed between the air hole and the rod can be eccentric with respect to the axis of the air spring.
[0003]
That is, the above-described structure capable of eccentricity adopts the rubber bush, and the inner diameter of the rod insertion hole of the air spring is increased by 1 mm to 5 mm with respect to the outer diameter of the rod (in other words, the gap is 0.5 mm). The structure is set to ~ 2.5mm.
[0004]
In strut suspension, when the steering wheel is turned off while running, the shock absorber rod swings around the upper mount (connecting part to the vehicle body) and is eccentric with respect to the axis of the air spring. This prevents the rod from interfering with the rod insertion hole.
[0005]
[Problems to be solved by the invention]
However, depending on the vehicle type, the rod shaft center and the vehicle body joint surface may not be orthogonal to each other at the connecting portion (so-called upper mount) between the rubber bush at the upper end of the rod and the vehicle body side, or the same vehicle type. However, the orthogonality may be poor due to manufacturing variations, etc. Even if the steering is not turned off, the rod is already eccentric with respect to the air spring axis, and if the gap is less than 2 mm, the rod will It has been found that it interferes with the rod insertion hole.
[0006]
Furthermore, in a strut suspension, the strut shaft center (rod shaft center) and the load input shaft centering the center point of the upper mount and the tire ground contact point are misaligned. Moment acts. It has been found that the addition of this bending moment further facilitates the above-described interference between the rod and the insertion hole.
[0007]
Therefore, if the above-mentioned gap is made to be 2 mm or more, for example, a commercially available air seal packing has a small tension margin and remarkably deteriorates the sealing performance. Therefore, the packing having a particularly large tension margin is designed uniquely. There is a need.
[0008]
It is extremely difficult to design and develop a packing with high sealing performance while taking into account sliding, vibration and eccentricity during running.
Therefore, the present invention aims to prevent the rod and the rod insertion hole of the air spring and the shaft center from shifting even if a bending moment is applied to the strut (rod). Even if the angle with the surface is not orthogonal, it is another object to prevent the axis from being shifted similarly. Another object of the present invention is to reduce the development cost and the mold cost by making it possible to use a standard packing as a standard for an air spring.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a shock absorber, a coil spring, and an air spring, wherein the coil spring and the air spring are arranged in series, and the rod of the shock absorber penetrates the air spring. In the suspension device in which the shock absorber connects the vehicle body side and the axle side, a guide member for preventing eccentricity that is slidably fitted to the rod so as to reciprocate is provided in the air spring. In addition, the shock absorber is connected to the vehicle body via a bearing mechanism that can swing about one center point and that can rotate about the axis, and further, the internal pressure of the air spring can be reduced to the eccentric prevention guide. The air spring is arranged between the upper wall member and the lower wall member so as to be sealed with a sealing material that is disposed above and below the member and in contact with the rod. With membrane The upper wall member has a flange portion and a cylindrical portion projecting downward from the flange portion, and has a stepped hole for inserting a rod in the axial direction, and the cylindrical portion fits the sealing material into the stepped hole. The lower wall member includes a flange portion and a cylindrical portion protruding upward from the flange portion, and has a shaft hole. Further, the eccentricity prevention guide member is formed of a sliding bearing. In addition, the sliding bearing and the sealing material are fitted into the axial hole in the cylindrical portion, the cylindrical portion of the lower wall member is inserted into the elastic film, and the cylindrical portion of the lower wall member is inserted. The upper end outer periphery of the upper wall member is cut out to have a small diameter, and an air flow path having an inner opening end opened on the lower surface of the cylindrical portion of the upper wall member is provided through the flange portion from the cylindrical portion of the upper wall member. The inner opening end outside the upper end where the notch of the cylindrical portion of the lower wall member is formed. The lower surface of the cylindrical portion of the upper wall member and the upper surface of the cylindrical portion of the lower wall member are in contact with each other under a non-pressure state in which the air spring has no internal pressure. It is a thing.
Further, the above-mentioned bearing mechanism that can swing around one central point and rotate around the shaft center includes a vibration-proof rubber portion, and a ball bearing or a thrust bearing that is fitted into the shaft hole of the vibration-proof rubber portion. And a rotary bearing portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
FIG. 1 to FIG. 3 show an embodiment of an automobile wheel suspension device according to the present invention. This suspension device A includes a shock absorber (damper) 2, a coil spring 3, and an air spring 4. The air spring 4 is arranged in series on the upper part of the coil spring 3. And the rod 2a of the shock absorber 2 penetrates the air spring 4, and the shock absorber 2 connects the vehicle body side B and the axle side S. That is, the suspension device A is mounted between the vehicle body side B and the axle side S of the automobile. Here, “in series” refers to an arrangement in which the transmission of force between the vehicle body side B and the axle side S is not transmitted via only one, but is always transmitted via both. .
[0012]
More specifically, the lower part of the strut body 2b of the shock absorber 2 is attached to the axle side S --- the axle itself or a link or a fixture--and the upper part of the rod 2a of the shock absorber 2 is It is connected to the vehicle body side B through a bearing mechanism C that can swing around one center point O and can rotate around an axis L. As described above, the strut upper mount uses the bearing mechanism C that can swing around one central point O as a fulcrum and can rotate around the axis L under a thrust load.
[0013]
As the bearing mechanism C, a rubber vibration isolator 41 from the axis hole 42 is fitted into (which can also be rotated by the thrust load) ball bearings or thrust bare-ring of the rotational bearing 43, It is configured. More specifically, a plate member 41a that comes into contact with the mounting hole 7a of the mounting plate 7 on the vehicle body side B so as to be closed from below is integrally attached to the lower surface of the central bulging portion of the plate member 41a. The rubber member 41b constitutes the vibration isolating rubber part 41. The plate member 41a is provided with a male screw portion 9 in an upward projecting shape in advance. The male screw portion 9 is inserted into the hole of the mounting plate portion 7 and screwed with a nut 10. The anti-vibration rubber portion 41 is fixed to the vehicle body side B.
[0014]
The rotary bearing portion 43 is fitted on the rubber material 41b of the vibration isolating rubber portion 41, and the upper end of the rod 2a and the rotary bearing portion 43 are connected by the nut 27 via the spacer member 26 and the like.
In particular, the outer peripheral edge of the plate member 41a and the radial intermediate portion of the vibration isolating rubber portion 41 are interposed between the upper surface of the upper wall member 16 of the air spring 4 and a thrust member or an elastic member (in a conventional rubber bush). The equipment is omitted, and therefore the bearing mechanism C can swing (swing) around the center point O of the bearing portion 43 as a fulcrum (center).
[0015]
The coil spring 3 is disposed so as to surround an intermediate portion of the shock absorber (damper) 2. The lower end of the coil spring 3 is brought into contact with or attached to the receiving hook portion 14 projecting like a shell on the strut body 2b, and the upper end of the coil spring 3 is brought into contact with the lower wall member 15 of the air spring 4. Or attached. Further, in the other embodiment shown in FIG. 4, the same reference numerals are the same as those in FIG. The main difference is related to the bearing mechanism C, and FIG. 4 illustrates the case where the pillow ball joint 13 is used as the bearing mechanism C. That is, a male screw portion 9 is projected in advance upward on the mounting piece 8 that contacts the mounting hole portion 7 a of the mounting plate portion 7 on the vehicle body side B so as to be closed from below, and is formed in the mounting plate portion 7. The male screw portion 9 is inserted into the hole and screwed with a nut 10 from above, and the attachment piece 8 is fixed.
[0016]
The mounting piece 8 is fixed to the female member (outer shell) 11 of the pillow ball joint 13 in the shape of an outer casing, and the male spherical surface 12 is fixed to the upper end of the rod 2a. L can swing freely around the center point O of the pillow ball joint 13. FIG. 4 shows the case where the bearing mechanism C is a spherical bearing.
[0017]
Hereinafter, FIGS. 1 to 3 and FIG. 4 will be described together. The air spring 4 includes an upper wall member 16, the lower wall member 15, and an elastic film 17 interposed therebetween. That is, the upper opening portion and the lower opening portion of the elastic film 17 (made of rubber) such as a via barrel are sandwiched between the upper wall member 16 and the lower wall member 15 so as to be assembled.
[0018]
In the illustrated example, the upper wall member 16 has a disk shape having a stepped hole 20 composed of a small diameter hole portion 18 and a large diameter hole portion 19 at the center, and the large diameter hole portion 19 of the stepped hole 20 includes A concave groove 22 into which the sealing material 21 is fitted is formed. The upper wall member 16 includes a cylindrical portion 23 having the stepped hole 20 and a flange portion 24 connected in a protruding manner from the upper half portion of the cylindrical portion 23. The cylindrical portion 23 is a flange portion. The portion protruding downward from 24 protrudes into the elastic film 17, and the upper outer surface of the elastic film 17 contacts the flange portion 24.
[0019]
An air flow path 25 is provided through the upper wall member 16 so as to communicate and connect the inside of the elastic film 17 and an air pipe (not shown) on the outside (atmosphere side). The upper wall member 16 is provided so as to transmit axial force to the rotary bearing portion 43 (see FIG. 1) or the spherical body 12 (see FIG. 4) via the spacer member 26. In other words, the upper wall member 16 is tightened together with the spacer 26 and the rotary bearing 43 (see FIG. 1) or the spherical body 12 (see FIG. 4) by the stepped surface of the stepped hole 20 and the upper nut 27. , Fixed to the rod 2a. Thus, the upper wall member 16 of the air spring 4 is fixed to the rod 2a.
[0020]
On the other hand, the lower wall member 15 can reciprocate along the axis L with respect to the rod 2a. Specifically, the structure of the lower wall member 15 will be described. An upper hole portion 28 for fitting an eccentricity preventing guide member 30 which is directly slidably contacted with the rod 2a so as to freely reciprocate, and a concave groove 31 for fitting the seal material 29 therein. It is a disk type having an axial hole 33 composed of a lower hole portion 32 having
[0021]
Reference numeral 34 denotes a C-shaped retaining ring. As the guide member 30 for preventing eccentricity, for example, a sliding bearing made of a metal or plastic having low friction and wear resistance is suitable, and this sliding bearing is attached to the stepped portion 35. It fits into the upper hole 28 from above until it comes into contact, and is retained by the C-type retaining ring 34. 1 and 4 exemplify a U-shaped packing, and FIG. 2 illustrates a U-shaped packing having a dust seal tongue portion 29a. Indicates freedom.
[0022]
Further, the lower wall member 15 includes a cylindrical portion 36 having the axial hole 33 and a flange portion 37 continuously provided in a projecting manner from the lower end portion of the cylindrical portion 36. A portion where the cylindrical portion 36 protrudes upward from the flange portion 37 protrudes into the elastic film 17, and a lower outer surface of the elastic film 17 contacts the flange portion 37. The outer periphery of the upper end of the cylindrical portion 36 is formed with a notch so as to have a slightly smaller diameter. As shown in FIG. 1 or 4, the inner side of the air flow path 25 is in contact with the cylindrical portion 23 of the upper wall member 16. The opening end 25a is prevented from closing. In addition, an annular ridge portion 38 that receives the upper end of the coil spring 3 in a fitting manner is formed on the lower surface of the outer flange-shaped flange portion 37 in a protruding shape. Thus, the lower wall member 15 is a member that directly receives the elastic force of the coil spring 3. Below the lower wall member 15, a bump rubber 39 is attached to the rod 2a in an outer fitting manner.
[0023]
The shaft member of the lower wall member 15 has a function (operation) such that the eccentric preventing guide member 30 slidably fitted to the rod 2a so as to be reciprocally movable so as to always coincide with the axis L of the rod 2a. ) In other words, a guide member 30 for preventing eccentricity such as a slide bearing is provided in the air spring 4 so that the axial center of the air spring 4 and the axial center L of the rod 2a always coincide with each other.
[0024]
Further, as is clear from FIG. 1 or FIG. 4 and FIG. 2, the sealing materials (packings) 21 and 29 disposed above and below the guide member 30 are in sliding contact with the rod 2a to be in contact with the air spring 4 Seal the internal pressure.
[0025]
By controlling the supply and discharge of pressurized air to and from the air spring 4 through the air flow path 25, the elastic film 17 of the air spring 4 can be expanded and contracted (expanded and contracted) to adjust the vehicle height. .
[0026]
In the present invention, as described above, the vehicle body side B and the axle side S are connected up and down by a shock absorber (damper) 2 disposed along the axis L, and the air spring 4 is connected to the coil spring 3. The rod 2a of the shock absorber 2 is disposed so as to surround the upper portion of the air spring 4, and further, an eccentric prevention guide member 30 is provided inside the air spring 4, and the strut shaft (damper 2) is arranged in FIG. Even if an external force as shown by an arrow F is applied and a bending moment is applied accordingly, the shaft center L of the rod 2 a is not eccentric with respect to the shaft center of the air spring 4.
[0027]
Further, as shown in FIG. 1 or FIG. 4, when there is no internal pressure in the air spring 4, the upper wall member 16 and the lower wall member 15 come into contact with each other inside the air spring 4 to carry the vehicle body load and to be elastic. The film 17 is configured not to be loaded.
[0028]
Although not shown, pressurized air is supplied from the compressor to the air flow path 25 through an air tank, a solenoid valve, piping, and the like. The operation is performed by putting pressurized air into and out of the air spring 4 by opening and closing the solenoid valve with a switch near the driver's seat. Further, a battery or the like is used as the power source of the compressor.
[0029]
In the case of a user who places importance on the appearance of the vehicle (automobile) and the running performance, the air spring 4 is usually not filled with pressurized air, travels at a low vehicle height, and there is a step or the like. A method of using such as filling the pressurized air to raise the vehicle height and overcoming a step or the like is taken.
[0030]
Next, as shown in FIGS. 4 and 3, the suspension device A according to the present invention is attached to the front of the step wagon to form an embodiment of the present invention. At this time, a precision resin sliding bearing manufactured by NTN Co., Ltd. was used as the guide member 30 for preventing eccentricity, and a general U packing for air was used as the sealing materials 21 and 29. On the other hand, as a conventional example, as in the invention of Japanese Patent Application No. 2001-347837, a suspension device having a rubber bush type upper mount and a gap between a shock absorber rod and an air spring of 1.5 mm is illustrated. A test attached to the same part as 3 was adopted and a comparative test was performed. As a result of the test, in the conventional example, when the vehicle was raised and lowered by putting air into and out of the air spring with the steering wheel turned off, the air spring sometimes did not easily extend. When disassembled after the test, the inner surface of the hole of the lower wall member of the air spring and the rod were scratched.
[0031]
On the other hand, in the embodiment of the present invention, even when the steering wheel was turned off, the air spring 4 was able to extend smoothly and the rod 2a was not damaged at all.
[0032]
As shown in FIG. 3, in the strut suspension, the strut axis L and the straight line Lg (load input shaft) connecting the tire ground contact point G and the strut upper mount point (center point) O are shifted. The bending moment acts on the strut axis L. At this time, in the conventional example, a rubber bush is used for the upper mount, so if the clearance between the rod and the hole of the air spring is about 1.5 mm, the rod and the hole of the air spring will interfere with each other. It is considered that the rod of this was damaged and did not stretch smoothly. In the present invention, since the coil spring 3 and the air spring 4 are arranged in series with the above-described configuration, the entire spring constant can be reduced, and the ride comfort can be improved by reducing the impact from the ground or the like. In addition, by changing the internal pressure of the air spring 4, various riding comforts can be enjoyed (by changing the spring constant).
[0033]
【The invention's effect】
The present invention has the following remarkable effects by the above-described configuration.
Even in a state such as turning off the scan tearing rod 2a of the shock absorber 2 for holes of the air spring 4 constantly axis coincide, it can be smoothly stretchable. Moreover, as the sealing materials 21 and 29, a special packing having a large tension allowance is not required, and it is possible to apply a general-purpose packing that is inexpensive and easily available .
[0034]
Even if the rod axis L relative to the joint surface of the vehicle body side B is not orthogonally, rod axis L of the air spring 4 (aperture) without eccentricity relative to the axis, further, the air spring 4 smoothly Can be expanded and shortened.
[0035]
Further, as shown in FIG. 3, even if the strut suspension is a strut shaft (shaft center L) and the load input shaft Lg are displaced from each other and a bending moment is applied to the suspension device, the basic amount of eccentricity. Therefore, the air spring 4 can be smoothly expanded and contracted.
[0036]
Shi Lumpur material 21, 29 as may be used for packing for general commercial and sealability (sealability) can be stably ensured long term.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a partial cross-sectional explanatory view showing an embodiment of the present invention.
FIG. 2 is an enlarged view of a main part.
FIG. 3 is a front view illustrating an example of a usage method.
FIG. 4 is a partial cross-sectional explanatory view showing another embodiment.
[Explanation of symbols]
2 Shock absorber 3 Coil spring 4 Air spring
15 Lower wall member
16 Upper wall member
17 Elastic membrane
20 step hole
21 Sealing material
22 groove
23 cylindrical part
24 flange
29 Seal material
30 Guide member for preventing eccentricity
33 axial hole
36 cylindrical part
37 flange
41 Anti-vibration rubber
42 axial hole
43 Rotating bearing B Body side C Bearing mechanism
L axis
O Center point S Axle side

Claims

A shock absorber (2), a coil spring (3), and an air spring (4) are provided. The coil spring (3) and the air spring (4) are arranged in series, and the shock absorber (2) In the suspension device in which the rod (2a) passes through the air spring (4) and the shock absorber (2) connects the vehicle body side (B) and the axle side (S) to the rod (2a). A guide member (30) for preventing eccentricity that is slidably fitted in a reciprocating manner is provided in the air spring (4) . Further, the guide member (30) can be swung around one center point (O) and has an axis (L). The shock absorber (2) is connected to the vehicle body side (B) via a bearing mechanism (C) that can freely rotate, and the internal pressure of the air spring (4) is further reduced by the guide member ( 30 for preventing eccentricity). ) and are disposed above and below each other across the sealing member in contact with the rod (2a) (21 ), ( 29 ), and the air spring (4) has an elastic membrane ( 17 ) interposed between the upper wall member ( 16 ) and the lower wall member ( 15 ). ), And the upper wall member ( 16 ) includes a flange portion ( 24 ) and a cylindrical portion ( 23 ) projecting downward from the flange portion ( 24 ), and is a rod insertion step in the axial center (L) direction. has Tsukeana (20), the cylindrical portion (23) has a groove (22) Komu fitting the sealing material (21) to the perforated stepped (20), further, the lower wall member (15 ) Includes a flange portion ( 37 ) and a cylindrical portion ( 36 ) protruding upward from the flange portion ( 37 ), and has an axial hole ( 33 ), and the guide member for preventing eccentricity ( 30 ) is slippery. together consist of bearings,該滑Ri bearing and the sealing material (29), fitted to the shaft Kokoroana (33) at a said cylindrical portion (36), said lower wall member (15 Of the cylindrical portion (36) enters into the elastic membrane (17) in the upper end periphery of the cylindrical portion of the lower wall member (15) (36) are notches formed on the small diameter, the upper wall member (16) over the air flow path inner open end on the lower surface (25 a) opening of the cylindrical portion (23) and (25) the cylindrical portion of the upper wall member (16) from (23) to the flange (24) Te and transmural set, the inner opening end of (25 a), so as to correspond to the notches formed upper end periphery of the cylindrical portion of the lower wall member (15) (36), to the air spring (4) The lower surface of the cylindrical portion ( 23 ) of the upper wall member ( 16 ) and the upper surface of the cylindrical portion ( 36 ) of the lower wall member ( 15 ) are in contact with each other under a non-pressure state without internal pressure. A suspension device characterized by being configured as described above .

A shock absorber (2), a coil spring (3), and an air spring (4) are provided. The coil spring (3) and the air spring (4) are arranged in series, and the shock absorber (2) In the suspension device in which the rod (2a) passes through the air spring (4) and the shock absorber (2) connects the vehicle body side (B) and the axle side (S) to the rod (2a). A guide member (30) for preventing eccentricity that is slidably fitted in a reciprocating manner is provided in the air spring (4). Further, the guide member (30) can be swung around one center point (O) and has an axis (L). The shock absorber (2) is connected to the vehicle body side (B) via a bearing mechanism (C) that can freely rotate , and the internal pressure of the air spring (4) is further reduced by the guide member ( 30 for preventing eccentricity). ) and are disposed above and below each other across the sealing member in contact with the rod (2a) (21 ), ( 29 ), and the air spring (4) has an elastic membrane ( 17 ) interposed between the upper wall member ( 16 ) and the lower wall member ( 15 ). ), And the upper wall member ( 16 ) includes a flange portion ( 24 ) and a cylindrical portion ( 23 ) projecting downward from the flange portion ( 24 ), and is a rod insertion step in the axial center (L) direction. has Tsukeana (20), the cylindrical portion (23) has a groove (22) Komu fitting the sealing material (21) to the perforated stepped (20), further, the lower wall member (15 ) Includes a flange portion ( 37 ) and a cylindrical portion ( 36 ) protruding upward from the flange portion ( 37 ), and has an axial hole ( 33 ), and the guide member for preventing eccentricity ( 30 ) is slippery. together consist of bearings,該滑Ri bearing and the sealing material (29), fitted to the shaft Kokoroana (33) at a said cylindrical portion (36), said lower wall member (15 Of the cylindrical portion (36) enters into the elastic membrane (17) within, without pressure state under pressure is not in the air spring (4), the cylindrical portion of the upper wall member (16) (23) The lower surface and the upper surface of the cylindrical portion ( 36 ) of the lower wall member ( 15 ) are configured to contact each other, and can swing around one central point (O) and have an axis (L ) The bearing mechanism (C) that can freely rotate is composed of an anti-vibration rubber part ( 41 ) and a ball bearing or a thrust bearing that is fitted in the shaft hole ( 42 ) of the anti-vibration rubber part ( 41 ). A suspension device comprising a rotating bearing portion ( 43 ) .