JP2019124324A

JP2019124324A - Cylindrical vibration controller

Info

Publication number: JP2019124324A
Application number: JP2018006705A
Authority: JP
Inventors: 廷志久米; Takashi Kume; 有美原; Yumi Hara; 鈴木　康雄; Yasuo Suzuki; 康雄鈴木
Original assignee: Sumitomo Riko Co Ltd
Current assignee: Sumitomo Riko Co Ltd
Priority date: 2018-01-18
Filing date: 2018-01-18
Publication date: 2019-07-25

Abstract

To provide a cylindrical vibration controller of a novel structure capable of tuning a spring characteristic at large degree of freedom, and capable of attaining excellent durability.SOLUTION: In a cylindrical vibration controller 10 in which an inner shaft member 14 and an outer cylinder member 20 are elastically connected to each other over the whole circumference by an elastic connector 16, the elastic connector 16 is formed of foam polyurethane resin; the elastic connector 16 is disposed between the inner shaft member 14 and the outer cylinder member 20 in a state of being compressed in a direction orthogonal to an axis; inner projection parts 18, 18 are provided in the inner shaft member 14 so as to project to an outer periphery; an outer projection part 22 is provided in the outer cylinder member 20 so as to project to an inner periphery; the inner projection parts 18, 18 and the outer projection part 22 are overlapped with each other in axial projection; and the inner projection parts 18, 18 and the outer projection part 22 indirectly contact with each other in an axis direction through the elastic connector 16.SELECTED DRAWING: Figure 3

Description

本発明は、インナ軸部材とアウタ筒部材が弾性連結体で相互に弾性連結された構造を有する筒形防振装置に関するものである。 The present invention relates to a cylindrical vibration damping device having a structure in which an inner shaft member and an outer cylindrical member are elastically connected to each other by an elastic connecting member.

従来から、自動車のサスペンションブッシュなどに適用される筒形防振装置が知られている。筒形防振装置は、例えば、特開２００４−２０５０４９号公報（特許文献１）に開示された防振ブッシュのように、内筒と外筒が厚肉筒状のゴム状弾性体で相互に弾性連結された構造を有している。 2. Description of the Related Art Conventionally, a cylindrical vibration damping device applied to a suspension bush or the like of an automobile is known. The cylindrical vibration isolation device is, for example, an inner cylinder and an outer cylinder that are thick-walled cylindrical rubber-like elastic bodies, such as a vibration isolation bush disclosed in JP-A-2004-205049 (Patent Document 1). It has a resiliently coupled structure.

ところで、従来の筒形防振装置では、より柔らかいばね特性が必要な場合に、ゴム状弾性体に対して軸方向に貫通するすぐり孔を形成する構造も、一般的に知られている。例えば、特許文献１に示されているように、一対のすぐり孔が内筒を挟んだ径方向両側に形成されることで、径方向のばね特性が調節されるようになっている。 By the way, in the conventional cylindrical vibration-damping device, when softer spring characteristics are required, a structure is also generally known in which a burr hole penetrating in the axial direction is formed with respect to the rubber-like elastic body. For example, as disclosed in Patent Document 1, the spring characteristics in the radial direction are adjusted by forming a pair of blind holes on both sides in the radial direction across the inner cylinder.

ところが、特許文献１のようにすぐり孔が形成された構造では、ゴム状弾性体の弾性変形時にすぐり孔の内周面に応力の集中が生じて、ゴム状弾性体の耐久性が低下するおそれがあった。また、ゴム状弾性体が大きく変形して、すぐり孔が実質的になくなるまで潰れると、ゴム状弾性体の動ばねが急激に大きくなって、乗り心地の悪化などを引き起こすおそれもあった。 However, in the structure in which the flat hole is formed as in Patent Document 1, stress concentration may occur on the inner peripheral surface of the flat hole during elastic deformation of the rubber-like elastic body, and the durability of the rubber-like elastic body may be reduced. was there. In addition, when the rubber-like elastic body is largely deformed and crushed until the burr hole is substantially eliminated, the dynamic spring of the rubber-like elastic body may be rapidly enlarged, which may cause a deterioration in ride comfort and the like.

特開２００４−２０５０４９号公報JP 2004-205049 A

本発明は、上述の事情を背景に為されたものであって、その解決課題は、ばね特性を大きな自由度でチューニングすることができると共に、優れた耐久性を実現することもできる、新規な構造の筒形防振装置を提供することにある。 The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is that the spring characteristics can be tuned with a large degree of freedom, and excellent durability can also be realized. An object of the present invention is to provide a cylindrical vibration damping device having a structure.

以下、このような課題を解決するために為された本発明の態様を記載する。なお、以下に記載の各態様において採用される構成要素は、可能な限り任意の組み合わせで採用可能である。 The following describes aspects of the present invention made to solve such problems. In addition, the component employ | adopted in each aspect described below can be employ | adopted as much as possible in arbitrary combination.

本発明者らは、筒形防振装置において柔らかいばね特性を実現するために、インナ軸部材とアウタ筒部材を弾性連結する弾性連結体を発泡ポリウレタン樹脂によって形成することを検討した。ところが、発泡ポリウレタン樹脂製の弾性連結体によって軸直角方向の低動ばね化を図ると、弾性連結体の軸方向のばね特性が著しく柔らかくなって、軸方向の入力に対するインナ軸部材とアウタ筒部材の相対変位量が大きくなり過ぎたり、インナ軸部材とアウタ筒部材の軸方向での相対位置が安定して保持されなくなるといった不具合があった。そこで、本発明者らは、かかる問題を解決すべく多くの検討と実験を行った結果、発泡ポリウレタン樹脂製の弾性連結体を採用することによって生じた上記の如き新たな問題をも解決することが可能となる本発明を為すに至った。 The present inventors examined forming an elastic connecting body which elastically connects an inner shaft member and an outer cylinder member with foaming polyurethane resin, in order to realize a soft spring characteristic in a cylindrical vibration isolation device. However, when the dynamic connection in the direction perpendicular to the axis is reduced by the elastic connection body made of the foamed polyurethane resin, the spring characteristics of the elastic connection body in the axial direction become extremely soft and the inner shaft member and the outer cylindrical member for the input in the axial direction The relative displacement between the inner shaft member and the outer cylinder member may not be stably held. Accordingly, as a result of conducting a number of studies and experiments to solve such problems, the present inventors have also solved the above new problems caused by employing an elastic connector made of a foamed polyurethane resin. The present invention has been made possible.

すなわち、本発明の第一の態様は、インナ軸部材とアウタ筒部材が弾性連結体で全周に亘って相互に弾性連結された筒形防振装置において、前記弾性連結体が発泡ポリウレタン樹脂で形成されており、該弾性連結体が前記インナ軸部材と前記アウタ筒部材の間に軸直角方向に圧縮された状態で配されている一方、該インナ軸部材には外周へ突出するインナ凸部が設けられていると共に、該アウタ筒部材には内周へ突出するアウタ凸部が設けられており、それらインナ凸部とアウタ凸部が軸方向の投影において相互に重なり合っていると共に、それらインナ凸部とアウタ凸部が該弾性連結体を介して軸方向で間接的に当接するようになっていることを、特徴とする。 That is, according to the first aspect of the present invention, in the cylindrical vibration-damping device in which the inner shaft member and the outer cylindrical member are elastically connected to each other over the entire circumference by the elastic connection body, the elastic connection body is a polyurethane foam resin. An inner convex portion is formed on the inner shaft member, and the elastic connector is disposed in a state of being compressed in a direction perpendicular to the axis between the inner shaft member and the outer cylinder member. Are provided, and the outer cylindrical member is provided with an outer convex portion projecting to the inner periphery, and the inner convex portion and the outer convex portion overlap each other in axial projection, and It is characterized in that the convex portion and the outer convex portion are in contact with each other in the axial direction indirectly via the elastic coupling body.

このような第一の態様に従う構造とされた筒形防振装置によれば、弾性連結体が発泡ポリウレタン樹脂によって形成されていることにより、より柔らかいばね特性を容易に実現することができる。従って、柔らかいばね特性を得るために弾性連結体に形成されていた貫通穴（すぐり孔）などを設けることなく、十分に柔らかいばね特性を得ることが可能となって、弾性連結体において貫通穴などの形成による応力の集中化を回避することもできる。 According to the cylindrical vibration-damping device having the structure according to the first aspect, softer spring characteristics can be easily realized by forming the elastic connector from the foamed polyurethane resin. Therefore, it is possible to obtain a sufficiently soft spring characteristic without providing a through hole (surrounding hole) or the like formed in the elastic connector in order to obtain a soft spring characteristic, and a through hole or the like in the elastic connector It is also possible to avoid stress concentration due to the formation of

さらに、弾性連結体がインナ軸部材とアウタ筒部材の間で軸直角方向に圧縮されていることから、弾性連結体の圧縮変形量を調節することによって、弾性連結体のばね特性を大きな自由度でチューニングすることができる。 Furthermore, since the elastic connector is compressed in the direction perpendicular to the axis between the inner shaft member and the outer cylinder member, the spring characteristics of the elastic connector can be increased by adjusting the amount of compressive deformation of the elastic connector. Can be tuned.

また、インナ軸部材に設けられたインナ凸部とアウタ筒部材に設けられたアウタ凸部が軸方向の投影において重なり合っていると共に、それらインナ凸部とアウタ凸部が軸方向で弾性連結体を介して間接的に当接するようになっている。それ故、インナ凸部とアウタ凸部の軸方向間における弾性連結体の圧縮ばね成分によって、筒形防振装置の軸方向のばね特性を比較的に硬く設定することが可能となる。その結果、インナ軸部材とアウタ筒部材の軸方向の相対変位が抑えられて、弾性連結体の損傷やアウタ筒部材からの抜けなどが防止される。 Further, the inner convex portion provided on the inner shaft member and the outer convex portion provided on the outer cylindrical member overlap in the projection in the axial direction, and the inner convex portion and the outer convex portion are elastically coupled in the axial direction. It comes in contact indirectly via Therefore, the axial spring characteristics of the cylindrical vibration damping device can be set relatively hard by the compression spring component of the elastic connector between the inner convex portion and the outer convex portion in the axial direction. As a result, the relative displacement between the inner shaft member and the outer cylindrical member in the axial direction is suppressed, and damage to the elastic connector and removal from the outer cylindrical member are prevented.

本発明の第二の態様は、第一の態様に記載された筒形防振装置において、前記インナ凸部に対して軸方向の両側に離れて前記アウタ凸部が配されているものである。 According to a second aspect of the present invention, in the cylindrical vibration-damping device described in the first aspect, the outer convex portions are disposed apart on both sides in the axial direction with respect to the inner convex portions. .

第二の態様によれば、アウタ凸部がインナ凸部の軸方向両側に配されることから、インナ凸部とアウタ凸部の軸方向間で圧縮される弾性連結体の圧縮ばね成分によって、筒形防振装置の軸方向両側のばね特性を硬く設定することが可能となる。 According to the second aspect, since the outer convex portion is disposed on both sides in the axial direction of the inner convex portion, the compression spring component of the elastic coupling body compressed between the axial direction of the inner convex portion and the outer convex portion It becomes possible to set rigidly the spring characteristic of the axial direction both sides of a cylindrical vibration damping device.

本発明の第三の態様は、第二の態様に記載された筒形防振装置において、前記アウタ凸部が前記アウタ筒部材の軸方向両端部を内周へ曲げて形成されており、該アウタ凸部の内周端部に折返部が設けられていると共に、該折返部の内周面が湾曲面で構成されているものである。 According to a third aspect of the present invention, in the cylindrical vibration damping device described in the second aspect, the outer convex portion is formed by bending both axial end portions of the outer cylindrical member toward the inner periphery, A turnback portion is provided at an inner peripheral end portion of the outer convex portion, and an inner peripheral surface of the turnback portion is formed of a curved surface.

第三の態様によれば、アウタ筒部材においてアウタ凸部を簡単に形成することができる。しかも、アウタ凸部の内周端部に折返部が設けられていることで、アウタ筒部材の端部のエッジが弾性連結体に接するのを防ぐことができて、弾性連結体の損傷を防ぐことができる。 According to the third aspect, the outer convex portion can be easily formed in the outer cylindrical member. Moreover, by providing the turnback portion at the inner peripheral end of the outer convex portion, it is possible to prevent the edge of the end of the outer cylindrical member from coming into contact with the elastic connector, thereby preventing damage to the elastic connector. be able to.

本発明の第四の態様は、第一〜第三の何れか１つの態様に記載された筒形防振装置において、前記アウタ凸部に対して軸方向の両側に離れて前記インナ凸部が配されているものである。 According to a fourth aspect of the present invention, in the cylindrical vibration damping device described in any one of the first to third aspects, the inner convex portion is spaced apart on both sides in the axial direction with respect to the outer convex portion. It is arranged.

第四の態様によれば、インナ凸部がアウタ凸部の軸方向両側に配されることから、インナ凸部とアウタ凸部の軸方向間で圧縮される弾性連結体の圧縮ばね成分によって、筒形防振装置の軸方向両側のばね特性を硬く設定することが可能となる。 According to the fourth aspect, since the inner convex portion is disposed on both sides in the axial direction of the outer convex portion, the compression spring component of the elastic connection body compressed between the axial direction of the inner convex portion and the outer convex portion It becomes possible to set rigidly the spring characteristic of the axial direction both sides of a cylindrical vibration damping device.

本発明によれば、弾性連結体が発泡ポリウレタン樹脂によって形成されていることにより、より柔らかいばね特性を容易に実現することが可能となって、貫通穴などのばね低減手段を特別に設ける必要がなく、貫通穴などの形成による応力の集中化を回避することも可能になる。更に、弾性連結体がインナ軸部材とアウタ筒部材の間で軸直角方向に圧縮されていることから、弾性連結体の圧縮変形の比率を調節することによって、弾性連結体のばね特性を大きな自由度でチューニングすることができる。また、インナ凸部とアウタ凸部の軸方向間における弾性連結体の圧縮ばね成分によって、筒形防振装置の軸方向のばね特性を比較的に硬く設定することが可能となり、インナ軸部材とアウタ筒部材の軸方向の相対変位が抑えられることから、弾性連結体の損傷やアウタ筒部材からの抜けなどを防ぐことができる。 According to the present invention, since the elastic connector is formed of the foamed polyurethane resin, it is possible to easily realize softer spring characteristics, and it is necessary to specially provide spring reduction means such as through holes. It is also possible to avoid concentration of stress due to formation of through holes and the like. Furthermore, since the elastic connector is compressed in the direction perpendicular to the axis between the inner shaft member and the outer cylindrical member, the spring characteristics of the elastic connector can be made largely free by adjusting the ratio of the compressive deformation of the elastic connector. Can be tuned in degrees. Further, by the compression spring component of the elastic connector between the inner convex portion and the outer convex portion in the axial direction, it becomes possible to set the axial spring characteristic of the cylindrical vibration damping device relatively hard, and the inner shaft member Since the relative displacement of the outer cylindrical member in the axial direction is suppressed, it is possible to prevent damage to the elastic connection body and detachment from the outer cylindrical member.

本発明の第一の実施形態としてのサスペンションブッシュを示す斜視図。FIG. 1 is a perspective view showing a suspension bush as a first embodiment of the present invention. 図１に示すサスペンションブッシュの正面図。The front view of the suspension bush shown in FIG. 図２のＩＩＩ−ＩＩＩ断面図。III-III sectional drawing of FIG. 図３のＩＶ−ＩＶ断面図。IV-IV sectional drawing of FIG. 図１に示すサスペンションブッシュを構成するブッシュ本体の断面図であって、図６のＶ−Ｖ断面に相当する図。It is sectional drawing of the bush main body which comprises the suspension bush shown in FIG. 1, Comprising: The figure corresponded in the VV cross section of FIG. 図５のＶＩ−ＶＩ断面図。VI-VI sectional drawing of FIG. 図５に示すブッシュ本体を縮径前のアウタ筒部材に挿入した状態を示す正面図。The front view which shows the state which inserted the bush main body shown in FIG. 5 in the outer cylinder member before diameter reduction. 図７のＶＩＩＩ−ＶＩＩＩ断面図。VIII-VIII sectional drawing of FIG. 本発明の第二の実施形態としてのサスペンションブッシュを示す正面図。The front view which shows the suspension bush as 2nd embodiment of this invention. 図９のＸ−Ｘ断面図。9. XX sectional drawing of FIG. 図１０のＸＩ−ＸＩ断面図。XI-XI sectional drawing of FIG.

以下、本発明の実施形態について、図面を参照しつつ説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１〜４には、本発明に従う構造とされた筒形防振装置の第一の実施形態として、自動車用のサスペンションブッシュ１０を示す。サスペンションブッシュ１０は、ブッシュ本体１２を備えており、ブッシュ本体１２は、インナ軸部材１４に弾性連結体１６が固着された構造を有している。以下の説明において、原則として、上下方向とは図２中の上下方向を、前後方向とは軸方向である図３中の左右方向を、左右方向とは図２中の左右方向を、それぞれ言う。なお、以下の説明における上下方向と前後方向と左右方向は、サスペンションブッシュ１０の車両装着状態における車両の上下方向、前後方向、左右方向とは、必ずしも一致しない。 1 to 4 show a suspension bush 10 for a car as a first embodiment of a cylindrical vibration-damping device constructed according to the present invention. The suspension bush 10 includes a bush main body 12, and the bush main body 12 has a structure in which an elastic connecting member 16 is fixed to an inner shaft member 14. In the following description, in principle, the vertical direction means the vertical direction in FIG. 2, the longitudinal direction means the horizontal direction in FIG. 3 which is the axial direction, and the horizontal direction means the horizontal direction in FIG. . In the following description, the vertical direction, the front-rear direction, and the left-right direction do not necessarily coincide with the vertical direction, the front-rear direction, or the left-right direction of the vehicle when the suspension bush 10 is mounted on the vehicle.

より詳細には、インナ軸部材１４は、金属などで形成された硬質の部材であって、全体として前後方向に直線的に延びる厚肉小径の略円筒形状を有している。更に、インナ軸部材１４は、軸方向の中央部分において外周へ突出するインナ凸部１８，１８を備えている。本実施形態のインナ凸部１８は、図５，６などにも示すように、インナ軸部材１４と一体形成されて上下各一方側へ突出しており、基端部分の表面がインナ軸部材１４におけるインナ凸部１８を外れた部分の外周面に対して滑らかに連続していると共に、突出先端部分の表面が角や部分的な凹凸を持たない滑らかな湾曲面で構成されている。これにより、インナ凸部１８の突出先端部における軸方向外側の面が、突出先端側に向けて軸方向内側に傾斜するテーパ面１９とされている。 More specifically, the inner shaft member 14 is a hard member formed of metal or the like, and has a thick, small diameter, substantially cylindrical shape extending linearly in the front-rear direction as a whole. Furthermore, the inner shaft member 14 is provided with inner convex portions 18 and 18 which project to the outer periphery at a central portion in the axial direction. The inner convex portion 18 of the present embodiment is integrally formed with the inner shaft member 14 and protrudes upward and downward one side as shown in FIGS. 5 and 6 and the like, and the surface of the base end portion is the inner shaft member 14 While being smoothly continuous with the outer peripheral surface of the portion out of the inner convex portion 18, the surface of the protruding tip portion is constituted by a smooth curved surface having no corner or partial unevenness. Thus, the axially outer surface of the projecting tip end portion of the inner convex portion 18 is made to be a tapered surface 19 which inclines inward in the axial direction toward the projecting tip end side.

弾性連結体１６は、全体として円環形状乃至は円筒形状とされており、軸方向両面が外周へ向けて次第に軸方向内側へ傾斜する傾斜面とされて、前後方向の厚さ寸法が外周へ向けて次第に小さくなっている。なお、本実施形態の弾性連結体１６は、軸方向中央を通って軸直角方向に広がる平面に関して略面対称の形状とされている。 The elastic connector 16 is generally in the form of a ring or a cylinder, and both axial surfaces are inclined surfaces which are gradually inclined inward in the axial direction toward the outer periphery, and the thickness dimension in the front-rear direction is the outer periphery It is getting smaller and smaller. In addition, the elastic connection body 16 of this embodiment is made into the shape substantially surface-symmetrical with respect to the plane which spreads in an axis-perpendicular direction through an axial direction center.

さらに、弾性連結体１６は、多孔質の発泡ポリウレタン樹脂（以下、発泡ウレタン）で形成されている。弾性連結体１６を形成する発泡ウレタンの組成は、特に限定されるものではないが、例えば、エチレングリコール，ブタンジオールおよびアジピン酸の縮合重合体などからなるポリエステル系ポリオールをポリオール成分とし、ジフェニルメタンジイソシアネート（ＭＤＩ）や１，５−ナフタレンジイソシアネート（ＮＤＩ）などをイソシアネート成分とするウレタン原料からなる発泡ウレタンが、好適に採用される。また、ウレタン原料には、上記のポリオール成分とイソシアネート成分の他に、水などの発泡剤、エチレングリコールなどの鎖延長剤、触媒、整泡剤、加水分解防止剤、難燃剤、減粘剤、安定剤、充填剤、架橋剤、着色剤などが、必要に応じて配合される。また、発泡ウレタンの発泡率は、特に限定されないが、後述する弾性連結体１６の径方向の圧縮による直径の変化率以上とされていることが望ましく、例えば、２５〜７０％程度とされることが望ましい。 Furthermore, the elastic connector 16 is formed of a porous polyurethane foam resin (hereinafter, urethane foam). The composition of the foamed urethane forming the elastic connector 16 is not particularly limited. For example, a polyester-based polyol composed of a condensation polymer of ethylene glycol, butanediol and adipic acid etc. is used as a polyol component, and diphenylmethane diisocyanate ( Foamed urethane made of a urethane material having MDI), 1,5-naphthalene diisocyanate (NDI) or the like as an isocyanate component is preferably employed. In addition to the above-mentioned polyol component and isocyanate component, urethane raw materials also include foaming agents such as water, chain extenders such as ethylene glycol, catalysts, foam stabilizers, hydrolysis inhibitors, flame retardants, viscosity reducing agents, Stabilizers, fillers, crosslinking agents, colorants, etc. are blended as needed. Further, the foaming rate of the urethane foam is not particularly limited, but it is desirable that the rate of change in diameter due to compression in the radial direction of the elastic connector 16 described later be equal to or greater than, for example, about 25 to 70%. Is desirable.

更にまた、弾性連結体１６は、全周に亘って連続する環状乃至は筒状とされており、軸方向に貫通する穴は形成されていない。弾性連結体１６は、予め設定された軸方向に貫通する穴を備えていなければ、軸方向に貫通する連続気泡を含んでいても良いが、軸方向に貫通する気泡を持たないことが望ましく、例えば独立気泡の発泡ウレタンによって形成されている。 Furthermore, the elastic connecting member 16 is in the form of a continuous ring or tube around the entire circumference, and no axially penetrating hole is formed. The elastic connector 16 may include an axially penetrating continuous bubble unless it has a predetermined axially penetrating hole, but preferably has no axially penetrating bubble, For example, it is formed of closed-cell urethane foam.

そして、弾性連結体１６の内周面がインナ軸部材１４の外周面に固着されて、ブッシュ本体１２が構成されている。なお、インナ軸部材１４と弾性連結体１６を相互に固着する手段は、特に限定されないが、本実施形態では接着剤によって接着されている。 The inner peripheral surface of the elastic connecting member 16 is fixed to the outer peripheral surface of the inner shaft member 14 to constitute the bush main body 12. The means for fixing the inner shaft member 14 and the elastic connector 16 to each other is not particularly limited, but in the present embodiment, they are adhered by an adhesive.

かかるインナ軸部材１４と弾性連結体１６の接着状態において、インナ軸部材１４のインナ凸部１８，１８は、弾性連結体１６に埋設状態で固着されており、弾性連結体１６の内周面の前後両端部分がインナ凸部１８，１８よりも前後外側においてインナ軸部材１４の外周面に固着されている。 In the bonded state of the inner shaft member 14 and the elastic connector 16, the inner convex portions 18 and 18 of the inner shaft member 14 are fixed to the elastic connector 16 in a buried state, and the inner peripheral surface of the elastic connector 16 is The front and rear end portions are fixed to the outer peripheral surface of the inner shaft member 14 on the front and rear sides outside the inner projections 18 and 18.

また、ブッシュ本体１２には、アウタ筒部材２０が取り付けられている。アウタ筒部材２０は、金属などで形成された硬質の部材であって、図３などに示すように、全体として前後方向に延びる薄肉大径の略円筒形状を有している。更に、アウタ筒部材２０の軸方向寸法は、インナ軸部材１４の軸方向寸法よりも小さくされていると共に、インナ軸部材１４におけるインナ凸部１８，１８の同方向での最大寸法よりも大きくされている。 Further, an outer cylindrical member 20 is attached to the bush main body 12. The outer cylindrical member 20 is a hard member formed of metal or the like, and has a thin, large-diameter, substantially cylindrical shape extending in the front-rear direction as a whole, as shown in FIG. 3 and the like. Furthermore, the axial dimension of the outer cylindrical member 20 is made smaller than the axial dimension of the inner shaft member 14 and made larger than the maximum dimension of the inner convex portions 18, 18 in the inner shaft member 14 in the same direction. ing.

さらに、アウタ筒部材２０は、軸方向両端部がそれぞれ内周へ突出するアウタ凸部２２とされている。アウタ凸部２２は、アウタ筒部材２０の軸方向両端部が内周側へ曲げられて形成されており、内周側へ向けて突出する略円環板形状とされていると共に、内周端部に折返部２４が設けられている。この折返部２４は、円弧状に折り曲げられることで端縁部のエッジ２６が外周側へ向けられており、内周面が円弧状断面の滑らかな湾曲面で構成されている。なお、本実施形態では、アウタ凸部２２が内周に向けて軸方向外側へ傾斜するテーパ形状とされていると共に、折返部２４の内周面において後述するようにインナ凸部１８と対向する軸方向の内側部分が、軸方向外側に向けて内周へ傾斜するテーパ面２７とされている。 Furthermore, the outer cylindrical member 20 is formed as an outer convex portion 22 in which both axial end portions project toward the inner periphery. The outer convex portion 22 is formed by bending both end portions in the axial direction of the outer cylindrical member 20 to the inner peripheral side, and has a substantially annular plate shape projecting toward the inner peripheral side, and an inner peripheral end A turnaround portion 24 is provided in the unit. The folded portion 24 is bent in an arc shape so that the edge 26 of the end edge portion is directed to the outer peripheral side, and the inner peripheral surface is constituted by a smooth curved surface of an arc-shaped cross section. In the present embodiment, the outer convex portion 22 is formed into a tapered shape that is inclined outward in the axial direction toward the inner periphery, and faces the inner convex portion 18 on the inner peripheral surface of the folded portion 24 as described later. The axially inner portion is a tapered surface 27 that inclines radially outward toward the inner periphery.

ところで、アウタ筒部材２０は、後述する縮径加工によってブッシュ本体１２に装着される前の単体状態において、図７，８に示すような形状とされている。即ち、縮径加工前のアウタ筒部材２０は、全体として前後方向に延びる薄肉大径の略円筒形状を有しており、軸方向両端部が軸方向中間部分よりも小径とされた段付き円筒形状とされることで、軸方向中間部分には内周面に開口して全周に亘って連続する凹溝２８が形成されている。なお、縮径加工前のアウタ筒部材２０において、一対のアウタ凸部２２，２２は形成されていない。 The outer cylindrical member 20 has a shape as shown in FIGS. 7 and 8 in a single state before being mounted on the bush main body 12 by diameter reduction processing described later. That is, the outer cylindrical member 20 before the diameter reduction processing has a thin large diameter substantially cylindrical shape extending in the front and rear direction as a whole, and a stepped cylinder whose both axial end portions have a smaller diameter than the axial intermediate portion. Due to the shape, the axially intermediate portion is formed with a recessed groove 28 which is open on the inner circumferential surface and is continuous over the entire circumference. In addition, in the outer cylindrical member 20 before diameter reduction processing, a pair of outer convex parts 22 and 22 are not formed.

そして、縮径加工前のアウタ筒部材２０は、図７，８に示すように、ブッシュ本体１２の弾性連結体１６に外挿される。本実施形態では、アウタ筒部材２０がブッシュ本体１２の前後中央部分に外挿されており、弾性連結体１６の外周端部がアウタ筒部材２０の凹溝２８に嵌め入れられることによって、アウタ筒部材２０が弾性連結体１６に対して軸方向で位置決めされている。更に、弾性連結体１６は、縮径加工前のアウタ筒部材２０よりも大径とされていることから、アウタ筒部材２０に挿入されることによって径方向で縮径されており、インナ軸部材１４とアウタ筒部材２０の径方向間にある程度まで圧縮された状態で配されている。また、インナ軸部材１４に設けられたインナ凸部１８，１８の全体が、上下方向の投影においてアウタ筒部材２０と重なり合っていると共に、インナ凸部１８，１８よりも軸方向外方に位置するアウタ筒部材２０の軸方向両端部分が、弾性連結体１６の外周面よりも軸方向外側まで突出している。 Then, as shown in FIGS. 7 and 8, the outer cylindrical member 20 before the diameter reduction process is extrapolated to the elastic connection body 16 of the bush main body 12. In the present embodiment, the outer cylindrical member 20 is externally inserted in the front-rear central portion of the bush main body 12, and the outer peripheral end of the elastic connector 16 is fitted into the recessed groove 28 of the outer cylindrical member 20. A member 20 is axially positioned relative to the resilient connector 16. Furthermore, since the elastic connecting member 16 has a diameter larger than that of the outer cylindrical member 20 before the diameter reduction processing, the elastic connecting member 16 is reduced in diameter in the radial direction by being inserted into the outer cylindrical member 20, and the inner shaft member 14 and the outer cylindrical member 20 are arranged in a state of being compressed to a certain extent. In addition, the entire inner projections 18, 18 provided on the inner shaft member 14 overlap the outer cylindrical member 20 in the vertical projection, and are positioned axially outward of the inner projections 18, 18. Both axial end portions of the outer cylindrical member 20 protrude to the outside in the axial direction with respect to the outer peripheral surface of the elastic connector 16.

また、弾性連結体１６に外挿されたアウタ筒部材２０は、八方絞りなどの縮径加工によって、図１〜４に示す縮径後の状態まで変形せしめられて、アウタ筒部材２０の全体が小径化されると共に、アウタ筒部材２０の軸方向両端部にアウタ凸部２２，２２が形成される。アウタ凸部２２，２２は、弾性連結体１６の軸方向端面に押し当てられており、弾性連結体１６がそれらアウタ凸部２２，２２の軸方向間に挟み込まれることで、アウタ筒部材２０が弾性連結体１６の外周部分に非接着で嵌着されている。これにより、インナ軸部材１４と縮径加工後のアウタ筒部材２０が、弾性連結体１６によって全周に亘って相互に弾性連結されており、本実施形態のサスペンションブッシュ１０が形成される。 Further, the outer cylindrical member 20 extrapolated to the elastic coupling body 16 is deformed to a state after diameter reduction as shown in FIGS. The diameter is reduced, and the outer protrusions 22 and 22 are formed at both axial ends of the outer cylindrical member 20. The outer convex portions 22, 22 are pressed against the axial end face of the elastic connector 16, and the elastic connector 16 is sandwiched between the outer convex portions 22, 22 in the axial direction, whereby the outer cylindrical member 20 is The outer peripheral portion of the elastic connector 16 is fitted in a non-adhesive manner. As a result, the inner shaft member 14 and the outer cylindrical member 20 after the diameter reducing process are elastically connected to each other by the elastic connecting member 16 over the entire circumference, and the suspension bush 10 of the present embodiment is formed.

なお、本実施形態では、弾性連結体１６が、軸方向に貫通する穴などを持たず、全周に亘って連続する形状とされていることから、インナ軸部材１４とアウタ筒部材２０は、弾性連結体１６によって全周に亘って径方向で相互に弾性連結されている。尤も、ばね特性の調節などを目的とする凹所や軸方向の貫通穴などを形成することも可能であり、その場合、当該凹所や穴は、弾性連結体１６の予圧縮によって潰れて実質的に消失していても良いし、弾性連結体１６の予圧縮後に開口状態で残っていても良い。また、例えば、周方向に延びる筒状乃至は板状の中間部材を、弾性連結体１６の径方向中間部分に固着して、ばね特性を調節することもできる。 In the present embodiment, since the elastic connector 16 does not have a hole or the like penetrating in the axial direction but has a shape continuous over the entire circumference, the inner shaft member 14 and the outer cylindrical member 20 The elastic connectors 16 are elastically connected with each other in the radial direction over the entire circumference. However, it is also possible to form a recess for the purpose of adjusting the spring characteristics or the like, an axial through hole, etc., in which case the recess or hole is crushed by the precompression of the elastic connector 16 to be substantially Or may be left open after pre-compression of the elastic connector 16. Further, for example, a cylindrical or plate-like intermediate member extending in the circumferential direction may be fixed to a radially intermediate portion of the elastic connector 16 to adjust the spring characteristics.

このように、アウタ筒部材２０が弾性連結体１６に外嵌された状態で縮径されることにより、弾性連結体１６がインナ軸部材１４とアウタ筒部材２０の径方向間で更に圧縮されて、径方向のばね特性が弾性連結体１６の予圧縮によって調節される。本実施形態では、インナ軸部材１４が上下方向に突出する一対のインナ凸部１８，１８を備えていることから、アウタ筒部材２０が全周に亘って同じ量だけ縮径されると、弾性連結体１６は、上下方向において左右方向よりも大きな比率で圧縮されて、上下方向において左右方向よりも硬いばね特性が設定されるようになっている。 As described above, the diameter of the outer cylindrical member 20 is reduced in a state in which the outer cylindrical member 20 is externally fitted to the elastic connecting body 16, whereby the elastic connecting body 16 is further compressed between the inner shaft member 14 and the outer cylindrical member 20 in the radial direction. The radial spring properties are adjusted by the precompression of the elastic connection 16. In the present embodiment, since the inner shaft member 14 is provided with the pair of inner convex portions 18 and 18 projecting in the vertical direction, when the diameter of the outer cylindrical member 20 is reduced by the same amount over the entire circumference, elasticity is obtained. The connector 16 is compressed at a larger ratio in the vertical direction than in the horizontal direction, and spring characteristics that are harder in the vertical direction than in the horizontal direction are set.

サスペンションブッシュ１０では、弾性連結体１６が発泡ウレタンで形成されていることにより、弾性連結体１６に凹所や貫通穴などを形成することなく、径方向の柔らかいばね特性を容易に実現することができる。それ故、例えば振動入力による弾性連結体１６の弾性変形時に、弾性連結体１６において応力が局所的に集中するのを防ぐことができて、弾性連結体１６の耐久性の向上が図られる。 In the suspension bush 10, by forming the elastic connecting member 16 with urethane foam, it is possible to easily realize soft spring characteristics in the radial direction without forming a recess or a through hole in the elastic connecting member 16 it can. Therefore, it is possible to prevent local concentration of stress in the elastic connector 16 at the time of elastic deformation of the elastic connector 16 due to vibration input, for example, and the durability of the elastic connector 16 can be improved.

なお、弾性連結体１６は、多孔質の発泡ウレタンで形成されていることから、自動車用のサスペンションブッシュなどに要求されるばね特性を得るために、一般的な中実のゴムに比して径方向に大きく圧縮される。例えば、弾性連結体１６は、インナ軸部材１４のインナ凸部１８，１８とアウタ筒部材２０との径方向間において、圧縮前の弾性連結体１６の外径寸法に対して２５〜７０％という高比率で圧縮された状態で配設されている。尤も、弾性連結体１６の圧縮変形量は、要求されるばね特性や弾性連結体１６の発泡率などを考慮して、適宜に設定される。 In addition, since the elastic connecting body 16 is formed of porous urethane foam, in order to obtain the spring characteristics required for a suspension bush for automobiles and the like, the diameter is smaller than that of a general solid rubber. It is greatly compressed in the direction. For example, the elastic connector 16 is 25 to 70% of the outer diameter of the elastic connector 16 before compression between the inner convex portions 18 and 18 of the inner shaft member 14 and the outer cylindrical member 20 in the radial direction. It is arranged in a highly compressed state. However, the amount of compressive deformation of the elastic connector 16 is appropriately set in consideration of the required spring characteristics, the expansion ratio of the elastic connector 16 and the like.

ここにおいて、インナ軸部材１４のインナ凸部１８とアウタ筒部材２０のアウタ凸部２２，２２は、軸方向の投影において相互に重なり合っている。即ち、本実施形態では、アウタ筒部材２０の軸方向両端部に設けられたアウタ凸部２２，２２が、インナ凸部１８の軸方向各一方側に配置されており、それらインナ凸部１８とアウタ凸部２２，２２が軸方向で相互に離れていると共に、それらインナ凸部１８とアウタ凸部２２，２２の軸方向間には、弾性連結体１６が軸方向に連続して配されている。なお、図３，４に示すインナ凸部１８とアウタ凸部２２のオーバーラップ代ｄは、要求されるばね特性などに応じて適宜に設定される。 Here, the inner convex portion 18 of the inner shaft member 14 and the outer convex portions 22 and 22 of the outer cylindrical member 20 mutually overlap in the projection in the axial direction. That is, in the present embodiment, the outer convex portions 22 and 22 provided at both axial end portions of the outer cylindrical member 20 are disposed on one side of each of the inner convex portions 18 in the axial direction. The outer protrusions 22, 22 are axially separated from each other, and the elastic connecting member 16 is continuously disposed in the axial direction between the inner protrusions 18 and the outer protrusions 22, 22 in the axial direction. There is. In addition, the overlap allowance d of the inner convex part 18 shown to FIG.3, 4 and the outer convex part 22 is suitably set according to the spring characteristic etc. which are requested | required.

これにより、インナ軸部材１４とアウタ筒部材２０の間に軸方向の荷重が入力される際に、インナ凸部１８とアウタ凸部２２が弾性連結体１６を介して間接的に当接せしめられて、インナ凸部１８とアウタ凸部２２の軸方向間において弾性連結体１６が圧縮されるようになっている。それ故、弾性連結体１６の圧縮ばね成分によって比較的に硬いばね特性が発揮されて、インナ軸部材１４とアウタ筒部材２０の軸方向での相対変位量を抑えることができる。その結果、弾性連結体１６の過大な変形による損傷や、弾性連結体１６のアウタ筒部材２０からの抜け、インナ軸部材１４とアウタ筒部材２０の位置決め不良による車両の走行安定性への悪影響などが回避される。 Thus, when a load in the axial direction is input between the inner shaft member 14 and the outer cylindrical member 20, the inner convex portion 18 and the outer convex portion 22 are indirectly brought into contact with each other through the elastic connecting member 16. Thus, the elastic connector 16 is compressed between the inner convex portion 18 and the outer convex portion 22 in the axial direction. Therefore, a relatively hard spring characteristic is exhibited by the compression spring component of the elastic coupling body 16, and the relative displacement amount of the inner shaft member 14 and the outer cylindrical member 20 in the axial direction can be suppressed. As a result, damage due to excessive deformation of the elastic connecting member 16, the removal of the elastic connecting member 16 from the outer cylindrical member 20, an adverse effect on the running stability of the vehicle due to poor positioning of the inner shaft member 14 and the outer cylindrical member 20, etc. Is avoided.

特に本実施形態では、アウタ凸部２２がアウタ筒部材２０の軸方向両端部にそれぞれ設けられており、それらアウタ凸部２２，２２がインナ凸部１８に対して軸方向両側に配されている。そして、それらアウタ凸部２２，２２が何れもインナ凸部１８と軸方向の投影において重なり合っていると共に、軸方向荷重の入力時にそれらアウタ凸部２２，２２とインナ凸部１８が弾性連結体１６を介して間接的に当接するようになっている。それ故、インナ軸部材１４とアウタ筒部材２０が軸方向何れの側に相対変位したとしても、インナ凸部１８と何れかのアウタ凸部２２との軸方向間で弾性連結体１６が圧縮されて、弾性連結体１６の圧縮ばね成分による硬いばね特性をサスペンションブッシュ１０において軸方向の両側で得ることができる。 In particular, in the present embodiment, the outer convex portions 22 are respectively provided at both axial end portions of the outer cylindrical member 20, and the outer convex portions 22 and 22 are disposed on both sides in the axial direction with respect to the inner convex portion 18. . And while these outer convex parts 22 and 22 overlap with inner convex part 18 in the projection of an axial direction, these outer convex parts 22 and 22 and inner convex part 18 elastic connection object 16 at the time of an input of an axial load. It comes to contact indirectly through the Therefore, even if the inner shaft member 14 and the outer cylindrical member 20 are displaced relative to each other in the axial direction, the elastic connecting member 16 is compressed between the inner convex portion 18 and any of the outer convex portions 22 in the axial direction. Thus, hard spring characteristics due to the compression spring component of the elastic connector 16 can be obtained on both sides of the suspension bush 10 in the axial direction.

また、インナ凸部１８，１８の各軸方向外面がテーパ面１９とされていると共に、アウタ凸部２２の折返部２４の軸方向内面がテーパ面２７とされていることにより、アウタ筒部材２０が縮径される際に、弾性連結体１６が、径方向に圧縮されるだけでなく、テーパ面１９，２７の間で軸方向にも圧縮される。それ故、弾性連結体１６をアウタ筒部材２０に圧縮状態で挿入すると共に、アウタ筒部材２０を縮径加工して弾性連結体１６を圧縮することによって、サスペンションブッシュ１０の軸直角方向のばね特性に加えて軸方向のばね特性も調節することができる。 Further, the outer cylindrical members 20 and 20 are formed by forming the outer surfaces in the axial direction of the inner convex portions 18 and 18 as tapered surfaces 19 and the inner surface in the axial direction of the folded portion 24 of the outer convex portion 22 as the tapered surface 27. When the diameter of the elastic connector 16 is reduced, the elastic connector 16 is compressed not only radially but also axially between the tapered surfaces 19 and 27. Therefore, the spring characteristics of the suspension bush 10 in the direction perpendicular to the axis can be obtained by inserting the elastic connector 16 into the outer cylinder member 20 in a compressed state and reducing the diameter of the outer cylinder member 20 to compress the elastic connector 16. In addition to the above, axial spring characteristics can also be adjusted.

また、本実施形態では、インナ凸部１８の突出先端面が滑らかな湾曲面で構成されており、軸方向の投影においてアウタ凸部２２と重なり合うインナ凸部１８の突出先端部分が角や局所的な凹凸などを有していない。それ故、インナ凸部１８とアウタ凸部２２の間で弾性連結体１６が圧縮される際に、インナ凸部１８に固着された弾性連結体１６の内周面において応力の分散化が図られて、弾性連結体１６において亀裂などの損傷を防ぐことができる。 Further, in the present embodiment, the projecting tip end surface of the inner convex portion 18 is formed by a smooth curved surface, and the projecting tip end portion of the inner convex portion 18 overlapping with the outer convex portion 22 in the axial projection is angled or locally Have no irregularities. Therefore, when the elastic connector 16 is compressed between the inner convex portion 18 and the outer convex portion 22, the stress is dispersed on the inner peripheral surface of the elastic connector 16 fixed to the inner convex portion 18. Thus, damage such as a crack can be prevented in the elastic connector 16.

さらに、アウタ凸部２２の内周端部に折返部２４が設けられており、折返部２４において弾性連結体１６と接する内周面が滑らかな湾曲面とされている。それ故、アウタ凸部２２の端部のエッジ２６が弾性連結体１６に接するのを防ぐことができて、エッジ２６の接触による弾性連結体１６の損傷が防止されている。 Furthermore, a folded back portion 24 is provided at the inner peripheral end of the outer convex portion 22, and the inner circumferential surface in contact with the elastic connector 16 in the folded back portion 24 is a smooth curved surface. Therefore, it is possible to prevent the edge 26 of the end of the outer convex portion 22 from coming into contact with the elastic connector 16, and the damage of the elastic connector 16 due to the contact of the edge 26 is prevented.

図９〜１１には、本発明に従う構造とされた筒形防振装置の第二の実施形態として、自動車用のサスペンションブッシュ３０を示す。サスペンションブッシュ３０は、インナ軸部材３２とアウタ筒部材３４が、発泡ウレタン製の弾性連結体３６によって相互に弾性連結された構造を有している。以下の説明において、第一の実施形態と実質的に同一の部材および部位については、図中に同一の符号を付すことで説明を省略する。 FIGS. 9-11 show a suspension bush 30 for a car as a second embodiment of a cylindrical vibration-damping device constructed according to the invention. The suspension bush 30 has a structure in which the inner shaft member 32 and the outer cylindrical member 34 are elastically connected to each other by an elastic connecting member 36 made of urethane foam. In the following description, parts substantially the same as those of the first embodiment are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

より詳細には、インナ軸部材３２は、全体として厚肉小径の略円筒形状を有していると共に、全周に亘って外周へ突出するインナ凸部３８が軸方向両端部にそれぞれ一体形成されている。このインナ凸部３８は、軸方向外側の面が略軸直角方向に広がっていると共に、軸方向内側の面が外周へ行くに従って軸方向外側へ傾斜するテーパ面４０とされており、外周へ向けて次第に軸方向寸法が小さくなっている。なお、インナ軸部材３２の内孔は、略一定の円形穴断面形状で軸方向に延びていることから、インナ軸部材３２は、インナ凸部３８が形成された軸方向両端部において厚肉となっている。 More specifically, the inner shaft member 32 has a thick, small diameter, substantially cylindrical shape as a whole, and inner convex portions 38 projecting to the outer periphery are integrally formed on both end portions in the axial direction along the entire circumference. ing. The inner convex portion 38 has a tapered surface 40 in which the axially outer surface extends in the substantially axial direction and the axially inner surface is inclined outward in the axial direction as it goes to the outer periphery, and is directed to the outer periphery The axial dimension is becoming smaller and smaller. In addition, since the inner hole of the inner shaft member 32 extends in the axial direction with a substantially constant circular hole cross sectional shape, the inner shaft member 32 has a thick wall at both end portions in which the inner convex portion 38 is formed. It has become.

アウタ筒部材３４は、全体として薄肉大径の略円筒形状を有していると共に、軸方向中央部分が軸方向両端部分よりも小径とされることで、内周へ突出するアウタ凸部４２が軸方向中央部分に全周に亘って形成されている。本実施形態のアウタ凸部４２は、軸方向両側の面がそれぞれ内周に向けて軸方向内側に傾斜するテーパ面４４とされており、インナ凸部３８のテーパ面４０とアウタ凸部４２のテーパ面４４とが互いに略同じ傾斜角度で略平行に広がっている。 The outer cylindrical member 34 has a thin-walled large-diameter, substantially cylindrical shape as a whole, and the axially central portion is smaller in diameter than the axially opposite end portions, so that the outer convex portion 42 projecting to the inner periphery It is formed over the entire circumference at the axially central portion. The outer convex portion 42 in the present embodiment has a tapered surface 44 in which the surfaces on both axial sides are inclined inward in the axial direction toward the inner periphery, and the tapered surface 40 of the inner convex portion 38 and the outer convex portion 42 The tapered surfaces 44 extend substantially parallel to each other at substantially the same inclination angle.

そして、インナ軸部材３２がアウタ筒部材３４に挿通された状態で配設されており、それらインナ軸部材３２とアウタ筒部材３４が弾性連結体３６によって相互に弾性連結されている。弾性連結体３６は、前記第一の実施形態と同様の発泡ウレタンで形成されており、内周面がインナ軸部材３２に接着されている。また、アウタ筒部材３４に挿入されて縮径される前の成形状態の弾性連結体３６は、外周面が縮径加工前のアウタ筒部材３４の内周面に略対応する形状とされており、アウタ凸部４２に対応する凹溝が軸方向中央部分に形成されている。 The inner shaft member 32 is disposed in a state of being inserted into the outer cylindrical member 34, and the inner shaft member 32 and the outer cylindrical member 34 are elastically connected to each other by the elastic connecting member 36. The elastic connector 36 is formed of the same urethane foam as that of the first embodiment, and the inner peripheral surface thereof is bonded to the inner shaft member 32. The elastic connector 36 in the molded state before being inserted into the outer cylindrical member 34 and reduced in diameter has a shape whose outer peripheral surface substantially corresponds to the inner peripheral surface of the outer cylindrical member 34 before diameter reduction processing. A concave groove corresponding to the outer convex portion 42 is formed at an axially central portion.

また、弾性連結体３６に外挿されたアウタ筒部材３４は、第一の実施形態のアウタ筒部材２０と同様に縮径加工されることによって、弾性連結体３６に非接着で外嵌装着されている。そして、アウタ筒部材３４が弾性連結体３６に外挿された状態で縮径されることによって、弾性連結体３６がインナ軸部材３２とアウタ筒部材３４の間で径方向に予圧縮されている。これにより、サスペンションブッシュ３０の径方向のばねが調節されており、弾性連結体３６の予圧縮による変形量を調節することで、目的とするばね特性が実現される。 Further, the outer cylindrical member 34 extrapolated to the elastic connecting body 36 is subjected to diameter reduction processing in the same manner as the outer cylindrical member 20 of the first embodiment, so that the outer cylindrical member 34 is fitted onto the elastic connecting body 36 without adhesion. ing. Then, the diameter of the elastic connecting body 36 is pre-compressed in the radial direction between the inner shaft member 32 and the outer cylindrical member 34 by reducing the diameter in a state where the outer cylindrical member 34 is extrapolated to the elastic connecting body 36. . Thereby, the spring of the suspension bush 30 in the radial direction is adjusted, and by adjusting the amount of deformation due to the precompression of the elastic connection body 36, the target spring characteristic is realized.

さらに、縮径加工されたアウタ筒部材３４のアウタ凸部４２に対する軸方向両側には、インナ軸部材３２のインナ凸部３８，３８が軸方向で離れて配されており、それらインナ凸部３８，３８とアウタ凸部４２が軸方向の投影において相互に重なり合っている。インナ凸部３８，３８とアウタ凸部４２の軸方向対向面は何れも弾性連結体３６に接しており、それらインナ凸部３８，３８とアウタ凸部４２が弾性連結体３６によって軸方向で連続的に弾性連結されている。 Further, inner convex portions 38, 38 of the inner shaft member 32 are axially separated from each other in the axial direction on both sides of the outer cylindrical member 34 whose diameter is reduced with respect to the outer convex portion 42. , 38 and the outer projection 42 mutually overlap in the axial projection. The axially facing surfaces of the inner convex portions 38, 38 and the outer convex portion 42 are in contact with the elastic connecting member 36, and the inner convex portions 38, 38 and the outer convex portion 42 are continuous in the axial direction by the elastic connecting member 36. Is elastically connected.

このように、インナ凸部３８，３８とアウタ凸部４２が軸方向の投影において相互に重なり合うようにオーバーラップしていると共に、それらインナ凸部３８，３８とアウタ凸部４２が軸方向で弾性連結体３６を介して間接的に当接するようになっていることにより、軸方向荷重の入力時に弾性連結体３６の圧縮ばねによる比較的に硬いばね特性を得ることができる。特に本実施形態では、インナ凸部３８，３８とアウタ凸部４２が何れも全周に亘って連続的に設けられており、インナ凸部３８，３８とアウタ凸部４２が軸方向の投影において全周に亘って互いに重なり合っていることから、それらインナ凸部３８，３８とアウタ凸部４２の軸方向投影における対向面積を大きく得ることができて、軸方向のばね特性をより硬く設定することも可能になる。 Thus, the inner projections 38, 38 and the outer projections 42 overlap so as to overlap each other in axial projection, and the inner projections 38, 38 and the outer projections 42 are elastic in the axial direction. By being in contact indirectly via the connecting body 36, it is possible to obtain relatively hard spring characteristics by the compression spring of the elastic connecting body 36 when an axial load is input. In the present embodiment, in particular, the inner convex portions 38, 38 and the outer convex portion 42 are provided continuously over the entire circumference, and the inner convex portions 38, 38 and the outer convex portion 42 are projected in the axial direction. Since they overlap each other over the entire circumference, it is possible to obtain a large opposing area in axial projection of the inner convex portions 38, 38 and the outer convex portion 42, and to set the axial spring characteristics more rigidly. Will also be possible.

本実施形態では、インナ凸部３８，３８の軸方向内面がテーパ面４０とされているとともにアウタ凸部４２の軸方向外面がテーパ面４４とされていることから、アウタ筒部材３４が縮径されると、インナ凸部３８，３８の各テーパ面４０とアウタ凸部４２のテーパ面４４との間で弾性連結体３６が径方向だけでなく軸方向にも圧縮されるようになっている。それ故、インナ凸部３８，３８とアウタ凸部４２の軸方向投影において重なり合う面積に加えて、弾性連結体３６の予圧縮量の調節によっても、サスペンションブッシュ３０の軸方向のばね特性を調節することが可能であり、サスペンションブッシュ３０の軸方向のばね特性をより大きな自由度で調節することが可能とされている。 In this embodiment, since the inner surface in the axial direction of the inner convex portions 38, 38 is the tapered surface 40 and the outer surface in the axial direction of the outer convex portion 42 is the tapered surface 44, the diameter of the outer cylindrical member 34 is reduced. Then, the elastic connector 36 is compressed not only in the radial direction but also in the axial direction between each of the tapered surfaces 40 of the inner convex portions 38, 38 and the tapered surface 44 of the outer convex portion 42. . Therefore, in addition to the overlapping area of the inner projections 38, 38 and the outer projection 42 in the axial projection, the adjustment of the precompression amount of the elastic connector 36 also adjusts the axial spring characteristics of the suspension bush 30. It is possible to adjust the axial spring properties of the suspension bush 30 with greater freedom.

以上、本発明の実施形態について詳述してきたが、本発明はその具体的な記載によって限定されない。例えば、インナ凸部は、必ずしも径方向両側に突出する一対である必要はなく、例えば、全周に亘って略一定の断面形状を有するインナ凸部を設けても良いし、周方向で突出高さが変化するインナ凸部を全周に亘って設けても良い。更に、インナ凸部は、インナ軸部材と別体で形成されて、インナ軸部材に固定されることで設けられるようにもできる。同様に、アウタ凸部をアウタ筒部材と別体で形成してアウタ筒部材に後固定することもできる。 Although the embodiments of the present invention have been described above in detail, the present invention is not limited by the specific description. For example, the inner convex portion does not necessarily have to be a pair projecting radially on both sides. For example, the inner convex portion having a substantially constant cross-sectional shape may be provided over the entire circumference, or the projection height in the circumferential direction The inner convex part which changes may be provided over the perimeter. Furthermore, the inner convex portion can be provided separately from the inner shaft member by being fixed to the inner shaft member. Similarly, the outer convex portion can be formed separately from the outer cylindrical member and post-fixed to the outer cylindrical member.

また、インナ凸部とアウタ凸部の形成数は、特に限定されない。具体的には、例えば、インナ凸部とアウタ凸部を各複数形成して、それらインナ凸部とアウタ凸部を軸方向で交互に配置すれば、軸方向荷重の入力時に弾性連結体が複数箇所で軸方向に圧縮されることによって、軸方向でより硬いばね特性を得易くなる。 Further, the number of inner convex portions and the number of outer convex portions are not particularly limited. Specifically, for example, if a plurality of inner convex portions and an outer convex portion are formed, and the inner convex portions and the outer convex portions are alternately arranged in the axial direction, a plurality of elastic connecting members are input when an axial load is input. By being axially compressed at the point, it is easier to obtain stiffer spring characteristics in the axial direction.

さらに、前記実施形態では、インナ凸部１８とアウタ凸部２２の軸方向対向面が何れも弾性連結体１６に当接状態で重ね合わされており、弾性連結体１６がインナ凸部１８とアウタ凸部２２の軸方向間において軸方向に連続して配された構造を例示したが、インナ凸部とアウタ凸部は、少なくとも一方が弾性連結体に対して軸方向で離れていても良い。具体的には、例えば、アウタ筒部材の軸方向両端部に設けられたアウタ凸部が、弾性連結体に対して軸方向外側に離れた位置に配されており、軸方向荷重の入力によるインナ軸部材とアウタ筒部材の軸方向での相対変位時に、アウタ凸部が弾性連結体に当接して、弾性連結体がインナ凸部とアウタ凸部の間で軸方向に圧縮される構造も採用できる。 Furthermore, in the above embodiment, the axially facing surfaces of the inner convex portion 18 and the outer convex portion 22 are superimposed on each other in a state of being in contact with the elastic connecting member 16, and the elastic connecting member 16 is in contact with the inner convex portion 18 and the outer convex. Although the structure continuously distribute | arranged to the axial direction between the axial directions of the part 22 was illustrated, at least one of an inner convex part and an outer convex part may be axially separated with respect to an elastic connection body. Specifically, for example, the outer convex portions provided at both axial end portions of the outer cylindrical member are disposed at positions separated axially outward with respect to the elastic connection body, and the inner by the input of the axial load At the time of relative displacement of the shaft member and the outer cylindrical member in the axial direction, a structure is also adopted in which the outer convex portion abuts against the elastic connection body and the elastic connection body is axially compressed between the inner convex portion and the outer convex portion it can.

また、インナ凸部は、必ずしもインナ軸部材を部分的に厚肉とするように設けられるものに限定されず、例えば、パイプ状のインナ軸部材を内外両面が大径となるように軸方向で部分的に拡径させることによって、インナ凸部を形成することもできる。また、アウタ凸部は、必ずしもパイプ状のアウタ筒部材を曲げ加工して形成されるものに限定されず、例えば、型成形されたアウタ筒部材において部分的に厚肉となるようにアウタ凸部を設けることもできる。なお、インナ軸部材とアウタ筒部材は、何れも円筒形状に限定されるものではなく、例えば長円筒形状などでも良い。また、弾性連結体の形状も、インナ軸部材およびアウタ筒部材の形状に応じて適宜に変更され得る。 Further, the inner convex portion is not necessarily limited to the one in which the inner shaft member is partially thickened. For example, the pipe-like inner shaft member may be axially extended so that both inner and outer surfaces have a large diameter. The inner convex portion can also be formed by partially enlarging the diameter. Further, the outer convex portion is not necessarily limited to one formed by bending a pipe-like outer cylindrical member, and for example, the outer convex portion may be partially thickened in a molded outer cylindrical member. Can also be provided. The inner shaft member and the outer cylindrical member are not limited to the cylindrical shape, and may be, for example, an elongated cylindrical shape. In addition, the shape of the elastic coupling body may be appropriately changed according to the shapes of the inner shaft member and the outer cylindrical member.

また、弾性連結体は、アウタ筒部材に挿入されることでアウタ筒部材を縮径することなく予圧縮が完了するようにしても良いし、径方向に圧縮されることなくアウタ筒部材に挿入された後、アウタ筒部材に縮径加工を施すことで予圧縮されるようにしても良い。更に、インナ軸部材の外径寸法が成形状態の弾性連結体の内径寸法よりも大きくされており、インナ軸部材が弾性連結体の中央孔に押し入れられることによって、弾性連結体が径方向に予圧縮されるようにもできる。なお、アウタ筒部材は、弾性連結体に接着されていても良い。 The elastic connector may be inserted into the outer cylindrical member so that pre-compression may be completed without reducing the diameter of the outer cylindrical member, or may be inserted into the outer cylindrical member without being radially compressed. After being compressed, the outer cylindrical member may be pre-compressed by reducing its diameter. Furthermore, the outer diameter dimension of the inner shaft member is made larger than the inner diameter dimension of the elastic connection body in the molded state, and the elastic connection body is radially pretensioned by pushing the inner shaft member into the central hole of the elastic connection body. It can also be compressed. The outer cylindrical member may be bonded to the elastic connector.

１０，３０：サスペンションブッシュ（筒形防振装置）、１４，３２：インナ軸部材、１６，３６：弾性連結体、１８，３８：インナ凸部、２０，３４：アウタ筒部材、２２，４２：アウタ凸部、２４：折返部 10, 30: Suspension bush (cylindrical antivibration device) 14, 32: Inner shaft member, 16, 36: Elastic coupling body, 18, 38: Inner convex portion, 20, 34: Outer cylindrical member, 22, 42: Outer convex part, 24: Folded part

Claims

インナ軸部材とアウタ筒部材が弾性連結体で全周に亘って相互に弾性連結された筒形防振装置において、
前記弾性連結体が発泡ポリウレタン樹脂で形成されており、該弾性連結体が前記インナ軸部材と前記アウタ筒部材の間に軸直角方向に圧縮された状態で配されている一方、
該インナ軸部材には外周へ突出するインナ凸部が設けられていると共に、該アウタ筒部材には内周へ突出するアウタ凸部が設けられており、それらインナ凸部とアウタ凸部が軸方向の投影において相互に重なり合っていると共に、それらインナ凸部とアウタ凸部が該弾性連結体を介して軸方向で間接的に当接するようになっていることを特徴とする筒形防振装置。 In a cylindrical vibration damping device in which an inner shaft member and an outer cylindrical member are elastically connected to each other over the entire circumference by an elastic connecting member,
The elastic connecting body is formed of a foamed polyurethane resin, and the elastic connecting body is disposed between the inner shaft member and the outer cylindrical member in a state of being compressed in a direction perpendicular to the axis,
The inner shaft member is provided with an inner convex portion projecting to the outer periphery, and the outer cylindrical member is provided with an outer convex portion projecting to the inner periphery, and the inner convex portion and the outer convex portion are axial A cylindrical vibration-damping device characterized in that they overlap each other in the projection of the direction, and that the inner convex portion and the outer convex portion indirectly contact in the axial direction via the elastic connection body. .

前記インナ凸部に対して軸方向の両側に離れて前記アウタ凸部が配されている請求項１に記載の筒形防振装置。 The cylindrical vibration-damping device according to claim 1, wherein the outer convex portions are disposed apart from each other in the axial direction with respect to the inner convex portion.

前記アウタ凸部が前記アウタ筒部材の軸方向両端部を内周へ曲げて形成されており、該アウタ凸部の内周端部に折返部が設けられていると共に、該折返部の内周面が湾曲面で構成されている請求項２に記載の筒形防振装置。 The outer convex portion is formed by bending both axial end portions of the outer cylindrical member toward the inner periphery, and a turnback portion is provided at the inner peripheral end portion of the outer convex portion, and the inner periphery of the turnback portion The cylindrical vibration-damping device according to claim 2, wherein the surface is a curved surface.

前記アウタ凸部に対して軸方向の両側に離れて前記インナ凸部が配されている請求項１〜３の何れか一項に記載の筒形防振装置。 The cylindrical vibration-damping device according to any one of claims 1 to 3, wherein the inner convex portions are disposed apart from each other in the axial direction with respect to the outer convex portion.