JP4417928B2

JP4417928B2 - Multi-link suspension device

Info

Publication number: JP4417928B2
Application number: JP2006170846A
Authority: JP
Inventors: 顕鈴木
Original assignee: Toyo Tire and Rubber Co Ltd
Current assignee: Toyo Tire Corp
Priority date: 2006-06-21
Filing date: 2006-06-21
Publication date: 2010-02-17
Anticipated expiration: 2026-06-21
Also published as: JP2008001166A

Description

本発明は、
種々の走行条件に適する車輪の動きを可能にする自動車等の車両のマルチリンク式サスペンション装置に関し、
詳しくは、
車輪を回転自在に支持する車輪支持体と、
一端部が前記車輪支持体に揺動自在に連結され、他端部が車体側部材に揺動自在に連結された前後一対のアッパーアームと、
一端部が前記車輪支持体に揺動自在に連結され、他端部が前記車体側部材に揺動自在に連結された前後一対のロアアームと、
一端部が前記車輪支持体に揺動自在に連結され、他端部が前記車体側部材に揺動自在に連結されたトーコントロールリンクとを備え、
前記前側のロアアームの他端部と前記車体側部材とは第１防振ブッシュを介して連結し、前記後側のロアアームの他端部と前記車体側部材とは第２防振ブッシュを介して連結し、前記トーコントロールリンクの他端部と前記車体側部材とは第３防振ブッシュを介して連結し、
前記第１防振ブッシュの軸芯が、平面視において、前記前側のロアアームの長手方向と直交する方向に沿い、前記第２防振ブッシュの軸芯が、平面視において、前記後側のロアアームの長手方向と直交する方向に沿うとともに、前記第３防振ブッシュの軸芯が、平面視において、前記トーコントロールリンクの長手方向と直交する方向に沿うように、前記第１防振ブッシュと第２防振ブッシュと第３防振ブッシュとが配置されているマルチリンク式サスペンション装置に関する。 The present invention
The present invention relates to a multi-link suspension device for a vehicle such as an automobile that enables wheel movement suitable for various driving conditions.
For more information,
A wheel support for rotatably supporting the wheel;
A pair of front and rear upper arms whose one end is swingably connected to the wheel support and whose other end is swingably connected to the vehicle body member;
A pair of front and rear lower arms, one end of which is swingably connected to the wheel support and the other end is swingably connected to the vehicle body side member;
A toe control link having one end portion swingably connected to the wheel support and the other end portion swingably connected to the vehicle body side member;
The other end portion of the front lower arm and the vehicle body side member are connected via a first vibration isolation bush, and the other end portion of the rear lower arm and the vehicle body side member are connected via a second vibration isolation bush. Connecting, the other end of the toe control link and the vehicle body side member are connected via a third anti-vibration bush,
The axial center of the first anti-vibration bush is along a direction orthogonal to the longitudinal direction of the front lower arm in plan view, and the axial center of the second anti-vibration bush is in the plan view of the rear lower arm. The first anti-vibration bush and the second anti-vibration bush and the second anti-vibration bush so that the axial center of the third anti-vibration bush is along the direction perpendicular to the longitudinal direction of the toe control link in plan view. The present invention relates to a multi-link suspension device in which a vibration isolation bush and a third vibration isolation bush are arranged.

従来、上記のマルチリンク式サスペンション装置における第１〜第３防振ブッシュは、図１１、図１２に示すように、軸部材としての内筒５２と、外筒５４と、両者を連結するゴム状弾性体５６とから成り、内外筒ともに径が一定のストレート筒状に形成されていた。
特開２００５−１１２２５８号公報 Conventionally, as shown in FIGS. 11 and 12, the first to third vibration isolating bushes in the multi-link suspension device described above are an inner cylinder 52 as an axial member, an outer cylinder 54, and a rubber-like connecting the two. It consists of an elastic body 56, and both the inner and outer cylinders are formed in a straight cylinder shape with a constant diameter.
JP 2005-112258 A

この種のマルチリンク式サスペンション装置（「サスペンション装置」と略称することがある）では、前後一対のロアアーム、トーコントロールリンク、及び、第１〜第３防振ブッシュは、平面視で傾斜姿勢に設定されていることから、車両の走行中には、第１〜第３防振ブッシュに、軸方向Ｊの力（図６参照）、軸直角方向Ｋの力（図６参照）、こじり方向Ｚの力（図６参照）、ねじり方向Ｎの力（図７参照）など種々の力が加わる。例えば、車体に対してサスペンション装置が上下方向に変位すると、第１〜第３防振ブッシュには、ねじり方向Ｎの力のみならずこじり方向Ｚの力も加わる。また、車体に対してサスペンション装置が左右方向に変位すると、第１〜第３防振ブッシュには、軸直角方向Ｋの力のみならず軸方向Ｊの力も加わる。 In this type of multi-link suspension device (sometimes abbreviated as “suspension device”), the pair of front and rear lower arms, toe control links, and first to third anti-vibration bushes are set in an inclined posture in plan view. Therefore, during traveling of the vehicle, the first to third vibration isolating bushings are subjected to the axial J force (see FIG. 6), the axial perpendicular direction K force (see FIG. 6), and the twisting direction Z. Various forces such as a force (see FIG. 6) and a force in the twisting direction N (see FIG. 7) are applied. For example, when the suspension device is displaced in the vertical direction with respect to the vehicle body, not only a force in the twisting direction N but also a force in the twisting direction Z is applied to the first to third vibration isolating bushes. Further, when the suspension device is displaced in the left-right direction with respect to the vehicle body, not only the force in the direction perpendicular to the axis K but also the force in the axis direction J is applied to the first to third vibration isolating bushes.

一般に、前後一対のアッパーアームと車体側部材との間にも防振ブッシュが介在しており、これらの防振ブッシュにも上記の種々の力が加わるが、路面からの横力がタイヤを介してサスペンション装置に加わった場合等は、前後一対のロアアームやトーコントロールリンクで踏ん張った状態になるので、第１〜第３防振ブッシュには、アッパーアーム側の防振ブッシュよりも大きな力が加わることになる。つまり、第１〜第３防振ブッシュは、サスペンション装置のばね定数（各アームや防振ブッシュによって決定されるサスペンション装置のばね定数）の値に大きく影響する。 Generally, anti-vibration bushes are also interposed between the pair of front and rear upper arms and the vehicle body side member, and the above-described various forces are also applied to these anti-vibration bushes, but the lateral force from the road surface passes through the tires. When it is applied to the suspension device, it is in a state where it is stretched by a pair of front and rear lower arms and toe control links. Therefore, a larger force is applied to the first to third vibration isolation bushes than the vibration isolation bush on the upper arm side. It will be. That is, the first to third vibration isolating bushes greatly affect the value of the spring constant of the suspension device (the spring constant of the suspension device determined by each arm and the vibration isolating bush).

上記従来の構造によれば、第１〜第３防振ブッシュは、内外筒ともに径が一定のストレート筒状に形成されていたために、第１〜第３防振ブッシュのこじり方向のばね定数が大きくなっていた。その結果、サスペンション装置の上下方向のばね定数が大きくなり、車両の乗り心地を良くすることが困難であった。また、上記従来の構造の第１〜第３防振ブッシュでは、軸方向のばね定数があまり大きくはなく、サスペンション装置の左右方向のばね定数を大きくすることができず、車両の操縦安定性を良くすることが困難であった。 According to the above-described conventional structure, the first to third vibration isolating bushes are formed in a straight cylindrical shape having a constant diameter for both the inner and outer cylinders. It was getting bigger. As a result, the spring constant in the vertical direction of the suspension device increases, making it difficult to improve the riding comfort of the vehicle. Further, in the first to third vibration isolating bushes of the conventional structure, the spring constant in the axial direction is not so large, and the spring constant in the left and right direction of the suspension device cannot be increased, thereby improving the steering stability of the vehicle. It was difficult to improve.

この問題を解消するために、内筒の軸方向の中央部が径方向外方側に膨出した球状の膨出部に構成する構造が考えられる。しかしながら、この構造であっても、ゴム状弾性体がこじり方向に弾性変形する場合、ゴム状弾性体の軸方向の両端部では、内筒と外筒の間でゴム状弾性体が圧縮されることになり、第１〜第３防振ブッシュのこじり方向のばね定数を十分小さくすることができなかった。そのために、サスペンション装置の上下方向のばね定数を小さくすることができず、車両の乗り心地を十分良くすることができなかった。そして、上記のように内筒の軸方向の中央部が径方向外方側に膨出した球状の膨出部に構成した構造では、第１〜第３防振ブッシュの軸方向のばね定数を大きくすることができなかった。そのために、サスペンション装置の左右方向のばね定数を大きくすることができず、車両の操縦安定性を十分良くすることができなかった。 In order to solve this problem, a structure is conceivable in which a central portion in the axial direction of the inner cylinder is formed as a spherical bulging portion bulging outward in the radial direction. However, even in this structure, when the rubber-like elastic body is elastically deformed in the twisting direction, the rubber-like elastic body is compressed between the inner cylinder and the outer cylinder at both axial ends of the rubber-like elastic body. As a result, the spring constant in the twisting direction of the first to third vibration-proof bushings could not be made sufficiently small. Therefore, the spring constant in the vertical direction of the suspension device cannot be reduced, and the riding comfort of the vehicle cannot be improved sufficiently. And in the structure which comprised the spherical center part which the center part of the axial direction of the inner cylinder swelled to the radial direction outward side as mentioned above, the spring constant of the axial direction of the 1st-3rd anti-vibration bushing is set. I couldn't make it bigger. Therefore, the spring constant in the left-right direction of the suspension device cannot be increased, and the steering stability of the vehicle cannot be sufficiently improved.

本発明は上記実状に鑑みて成されたもので、その目的は、車両の乗り心地を良くすることができ、しかも、車両の操縦安定性を良くすることができるマルチリンク式サスペンション装置を提供する点にある。 The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multi-link suspension device that can improve the riding comfort of the vehicle and improve the steering stability of the vehicle. In the point.

本第発明の特徴は、冒頭の［技術分野］に記載したマルチリンク式サスペンション装置において、
平面視において前記前側のロアアームが、車体幅方向で車体内方側ほど車体前側に位置する傾斜姿勢に設定され、平面視において前記後側のロアアームが、車体幅方向で車体内方側ほど車体後側に位置する傾斜姿勢に設定され、平面視において前記トーコントロールリンクが、車体幅方向で車体内方側ほど車体後側に位置する傾斜姿勢に設定され、かつ、車体幅方向に対する前記トーコントロールリンクの平面視における傾斜角度が、車体幅方向に対する前記前側のロアアームの平面視における傾斜角度、及び車体幅方向に対する前記後側のロアアームの平面視における傾斜角度に比べて小さく設定され、
前記第１防振ブッシュ、前記第２防振ブッシュ、及び前記第３防振ブッシュは、軸部材と、前記軸部材を囲む外筒と、前記軸部材と外筒を連結するゴム状弾性体とから成り、前記軸部材の軸方向の中央部が、径方向外方側に膨出した球状の膨出部に構成され、前記膨出部を囲む前記外筒の内周面部分が、前記膨出部の凸状の球面と同芯状の凹状の球面に形成され、
前記第１防振ブッシュと第２防振ブッシュと第３防振ブッシュのうち、前記第３防振ブッシュのみが、更に前記軸部材と外筒の間に位置する中間筒を備えて、前記ゴム状弾性体が、前記軸部材と中間筒を連結する内側ゴム状弾性体部分と、前記中間筒と外筒を連結する外側ゴム状弾性体部分とで構成され、前記中間筒の軸方向の中央部が、径方向外方側に膨出した球状の中間筒側膨出部に構成されて、前記中間筒側膨出部の外周面が、前記軸部材の膨出部の凸状の球面と同芯状の凸状の球面に形成されるとともに、前記中間筒側膨出部の内周面が、前記軸部材の膨出部の凸状の球面と同芯状の凹状の球面に形成され、前記第３防振ブッシュは、前記第１防振ブッシュ及び第２防振ブッシュに比べて、ねじり方向のばね定数及び軸方向のばね定数が小さく設定されている点にある。 The feature of the present invention is the multi-link suspension device described in [Technical Field] at the beginning.
In the plan view, the front lower arm is set to an inclined posture that is located on the front side of the vehicle body in the vehicle width direction, and in the plan view, the rear lower arm is in the rear side of the vehicle body in the vehicle width direction. In the plan view, the toe control link is set to an inclined posture that is positioned closer to the rear side of the vehicle body in the vehicle body width direction and the toe control link with respect to the vehicle body width direction. An inclination angle in a plan view of the front lower arm with respect to the vehicle body width direction is set smaller than an inclination angle in a plan view of the front lower arm with respect to the vehicle body width direction, and a tilt angle in plan view of the rear lower arm with respect to the vehicle body width direction,
The first vibration isolation bush, the second vibration isolation bush, and the third vibration isolation bush include a shaft member, an outer cylinder that surrounds the shaft member, and a rubber-like elastic body that connects the shaft member and the outer cylinder. The axial central portion of the shaft member is configured as a spherical bulging portion bulging radially outward, and an inner peripheral surface portion of the outer cylinder surrounding the bulging portion is the bulging portion. It is formed into a concave spherical surface that is concentric with the convex spherical surface of the protruding portion ,
Of the first vibration isolation bush, the second vibration isolation bush, and the third vibration isolation bush, only the third vibration isolation bush further includes an intermediate cylinder positioned between the shaft member and the outer cylinder, and the rubber A cylindrical elastic body is composed of an inner rubber-like elastic body portion that connects the shaft member and the intermediate cylinder, and an outer rubber-like elastic body portion that connects the intermediate cylinder and the outer cylinder, and is the center in the axial direction of the intermediate cylinder And the outer peripheral surface of the bulging portion of the intermediate cylinder side is a convex spherical surface of the bulging portion of the shaft member. A concentric convex spherical surface is formed, and an inner circumferential surface of the intermediate cylinder side bulging portion is formed as a concentric concave spherical surface with a convex spherical surface of the bulging portion of the shaft member. The third anti-vibration bush has a torsional spring constant and an axial spring constant compared to the first anti-vibration bush and the second anti-vibration bush. Lies in is set small.

この構成によれば、第１〜第３防振ブッシュの軸部材の軸方向の中央部が、径方向外方側に膨出した球状の膨出部に構成され、前記膨出部を囲む第１〜第３防振ブッシュの外筒の内周面部分が、前記膨出部の凸状の球面と同芯状の凹状の球面に形成されているから、第１〜第３防振ブッシュがこじり方向に変位すると、凸状の球面と、これに対して同芯状の凹状の球面との間のゴム状弾性体部分が主にせん断を受けるようになって、こじり方向におけるばね定数を低減することができる（前述したように、車体に対してサスペンション装置が上下方向に変位すると、第１〜第３防振ブッシュには、ねじり方向のみならずこじり方向の力も加わる）。これにより、サスペンション装置の上下方向のばね定数を小さくすることができる。そして、第１〜第３防振ブッシュが軸方向に変位すると、凸状の球面と、これに対して同芯状の凹状の球面との間のゴム状弾性体部分が圧縮力を受けるようになって、軸方向におけるばね定数を十分大きくすることができる（前述したように、車体に対してサスペンション装置が左右方向に変位すると、第１〜第３防振ブッシュには、軸直角方向のみならず軸方向の力も加わる）。これにより、サスペンション装置の左右方向のばね定数を大きくすることができる。 According to this structure, the axial center part of the shaft member of the first to third vibration-proof bushings is configured as a spherical bulge that bulges radially outward, and surrounds the bulge. Since the inner peripheral surface portion of the outer cylinder of the first to third vibration isolating bushes is formed in a concave spherical surface that is concentric with the convex spherical surface of the bulging portion, the first to third vibration isolating bushes are When displaced in the twisting direction, the rubber-like elastic body between the convex spherical surface and the concentric concave spherical surface is mainly subjected to shear, reducing the spring constant in the twisting direction. (As described above, when the suspension device is displaced in the vertical direction with respect to the vehicle body, force in the twisting direction as well as the twisting direction is applied to the first to third vibration isolating bushes). Thereby, the spring constant of the up-down direction of a suspension apparatus can be made small. When the first to third anti-vibration bushes are displaced in the axial direction, the rubber-like elastic body portion between the convex spherical surface and the concentric concave spherical surface receives a compressive force. Thus, the spring constant in the axial direction can be made sufficiently large (as described above, when the suspension device is displaced in the left-right direction with respect to the vehicle body, the first to third vibration isolating bushes are only in the direction perpendicular to the axis Without any axial force). Thereby, the spring constant of the left-right direction of a suspension apparatus can be enlarged.

本発明において、
前記軸部材及び外筒の軸方向に沿う断面において、前記凹状の球面によって定められる仮想球面と、前記凸状の球面によって定められる仮想球面との間のゴム状弾性体部分の周方向の両端部に、前記軸部材と、前記外筒の軸方向の両端部との間で露出した円弧状の一対の開放端面が各別に形成され、前記外筒は、軸方向中央部が両端部よりも薄肉の、外周面の径が一定のストレート筒状に形成されている構成にすることができる。 In the present invention,
In the cross section along the axial direction of the shaft member and the outer cylinder, both ends in the circumferential direction of the rubber-like elastic body portion between the virtual spherical surface defined by the concave spherical surface and the virtual spherical surface defined by the convex spherical surface In addition, a pair of arc-shaped open end surfaces exposed between the shaft member and both end portions in the axial direction of the outer cylinder are formed separately, and the outer cylinder has a thinner central portion in the axial direction than both end portions. It can be set as the structure currently formed in the straight cylinder shape where the diameter of an outer peripheral surface is constant.

この構成によれば、前記ゴム状弾性体部分の周方向の両端部に円弧状の一対の開放端面が各別に形成されており、前記ゴム状弾性体部分が前記周方向で軸部材や外筒に拘束されないから、第１〜第３防振ブッシュのこじり方向のばね定数を、より小さくすることができる。そして、軸方向中央部が両端部よりも薄肉の、外周面の径が一定のストレート筒状に形成されているから、第１〜第３防振ブッシュの外筒を他部材（一例として、ロアアームやトーコントロールリンクの端部に設けた連結用の筒部材）に圧入するといった手段をとることができる。 According to this configuration, a pair of arc-shaped open end surfaces are separately formed at both ends in the circumferential direction of the rubber-like elastic body portion, and the rubber-like elastic body portion is formed in the circumferential direction with the shaft member and the outer cylinder. Therefore, the spring constant in the twisting direction of the first to third vibration-proof bushings can be further reduced. And since the axial direction center part is thinner than both ends and is formed in the straight cylinder shape with the constant diameter of an outer peripheral surface, the outer cylinder of the 1st-3rd anti-vibration bush is made into another member (for example, a lower arm) Or a press-fitting into a connecting cylinder member provided at the end of the toe control link.

本発明においては、また、前記第３防振ブッシュが、前記軸部材と外筒の間に位置する中間筒を備えて、前記ゴム状弾性体が、前記軸部材と中間筒を連結する内側ゴム状弾性体部分と、前記中間筒と外筒を連結する外側ゴム状弾性体部分とで構成され、前記中間筒の軸方向の中央部が、径方向外方側に膨出した球状の中間筒側膨出部に構成されて、前記中間筒側膨出部の外周面が、前記軸部材の膨出部の凸状の球面と同芯状の凸状の球面に形成されるとともに、前記中間筒側膨出部の内周面が、前記軸部材の膨出部の凸状の球面と同芯状の凹状の球面に形成されている構成とされているので、次の作用効果が奏される。 Inner rubber in the present invention, also, that the third vibration damping bushing is provided with an intermediate tube located between the shaft member and the outer cylinder, the rubber-like elastic body, connects the shaft member and the intermediate tube A spherical intermediate cylinder comprising a cylindrical elastic body portion and an outer rubber-like elastic body portion connecting the intermediate cylinder and the outer cylinder, and a central portion in the axial direction of the intermediate cylinder bulging radially outward The intermediate bulge portion is formed as a side bulge portion, and an outer peripheral surface of the intermediate cylinder side bulge portion is formed into a convex spherical surface concentric with the convex spherical surface of the bulge portion of the shaft member, and the intermediate Since the inner peripheral surface of the tube-side bulged portion is formed as a concave spherical surface that is concentric with the convex spherical surface of the bulged portion of the shaft member , the following effects are achieved. The

上記の軸部材の膨出部の凸状の球面と、外筒の凹状の球面と、中間筒側膨出部の凸状の球面と、中間筒側膨出部の凹状の球面とが同芯状に位置しているから、第３防振ブッシュがこじり方向に変位したときに、軸部材の膨出部の凸状の球面（外周面）と中間筒側膨出部の凹状の球面（内周面）との間の内側ゴム状弾性体部分、及び、中間筒側膨出部の凸状の球面（外周面）と、外筒の凹状の球面（内周面）との間の外側ゴム状弾性体部分が主にせん断を受けるようになって、こじり方向におけるばね定数を低減することができる（前述したように、車体に対してサスペンション装置が上下方向に変位すると、第３防振ブッシュには、ねじり方向のみならずこじり方向の力も加わる）。これにより、サスペンション装置の上下方向のばね定数を小さくすることができる。 The convex spherical surface of the bulging portion of the shaft member, the concave spherical surface of the outer cylinder, the convex spherical surface of the intermediate cylindrical side bulging portion, and the concave spherical surface of the intermediate cylindrical side bulging portion are concentric. When the third anti-vibration bush is displaced in the twisting direction, the convex spherical surface (outer peripheral surface) of the bulging portion of the shaft member and the concave spherical surface (inner Inner rubber-like elastic body portion between the outer peripheral surface and the outer rubber between the convex spherical surface (outer peripheral surface) of the bulging portion on the intermediate cylinder side and the concave spherical surface (inner peripheral surface) of the outer cylinder The elastic body portion is mainly subjected to shearing, and the spring constant in the twisting direction can be reduced (as described above, when the suspension device is displaced in the vertical direction with respect to the vehicle body, the third vibration isolating bush Is applied not only torsional direction but also torsional direction force). Thereby, the spring constant of the up-down direction of a suspension apparatus can be made small.

また上記の構成によれば中間筒を備えていることから、第３防振ブッシュの軸直角方向のばね定数が大きくなる。従って、この第３防振ブッシュの軸直角方向のばね定数を、中間筒を備えていない防振ブッシュ（中間筒を備えていないだけでその他の構造は前記第３防振ブッシュと同じ）の軸直角方向のばね定数と同じに設定した場合、前記第３防振ブッシュのゴム状弾性体を、中間筒を備えていない防振ブッシュのゴム状弾性体よりも軟らかく設定することができて、前記第３防振ブッシュのねじり方向のばね定数を小さくすることができ、サスペンション装置の上下方向のばね定数を、より小さくすることができる（車体に対してサスペンション装置が上下方向に変位すると、第１〜第３防振ブッシュには、ねじり方向の力やこじり方向の力が加わる）。 Moreover, according to said structure, since the intermediate cylinder is provided, the spring constant of the 3rd anti-vibration bush in the direction perpendicular to the axis becomes large. Accordingly, the spring constant in the direction perpendicular to the axis of the third vibration isolating bush is set to the axis of the vibration isolating bush that does not include the intermediate cylinder (the other structure is the same as that of the third anti-vibration bush only with no intermediate cylinder). When set to the same as the spring constant in the right-angle direction, the rubber-like elastic body of the third vibration-proof bushing can be set softer than the rubber-like elastic body of the vibration-proof bushing that does not include an intermediate cylinder, The spring constant in the torsional direction of the third vibration isolating bush can be reduced, and the spring constant in the vertical direction of the suspension apparatus can be further reduced (if the suspension apparatus is displaced in the vertical direction with respect to the vehicle body, the first constant To the third anti-vibration bush is applied a twisting force and a twisting force).

上記のように、前記第３防振ブッシュのゴム状弾性体を、中間筒を備えていない防振ブッシュのゴム状弾性体よりも軟らかく設定した場合、前記第３防振ブッシュの軸方向のばね定数も小さくなる。軸方向のばね定数が小さくなると、サスペンション装置の左右方向のばね定数が小さくなる（前述したように、車体に対してサスペンション装置が左右方向に変位すると、第３防振ブッシュには、軸直角方向のみならず軸方向の力も加わる）。しかしながら、通常、車体幅方向に対するトーコントロールリンクの平面視における傾斜角度は、車体幅方向に対する前側ロアアームの平面視における傾斜角度や、車体幅方向に対する後側ロアアームの平面視における傾斜角度に比べて小さくて、トーコントロールリンク用の第３防振ブッシュの軸方向のばね定数の低減は、前側ロアアーム用の第１防振ブッシュの軸方向のばね定数の低減や、後側ロアアーム用の第２防振ブッシュの軸方向のばね定数の低減ほど、サスペンション装置の左右方向のばね定数の低減に影響を与えることはない。従って、本発明の上記構成によれば、サスペンション装置の左右方向のばね定数の低減を小さく抑えることができる。 As described above, when the rubber-like elastic body of the third vibration-proof bushing is set to be softer than the rubber-like elastic body of the vibration-proof bushing not provided with the intermediate cylinder, the axial spring of the third vibration-proof bushing The constant also becomes smaller. When the axial spring constant decreases, the left and right spring constant of the suspension device decreases (as described above, when the suspension device is displaced laterally with respect to the vehicle body, the third vibration isolating bush has a direction perpendicular to the axis. As well as axial force). However, the inclination angle of the toe control link in plan view with respect to the vehicle body width direction is usually smaller than the inclination angle of the front lower arm in plan view with respect to the vehicle width direction and the inclination angle in plan view of the rear lower arm with respect to the vehicle width direction. Thus, the axial spring constant of the third vibration isolating bush for the toe control link can be reduced by reducing the axial spring constant of the first anti-vibration bush for the front lower arm or the second vibration isolating for the rear lower arm. The reduction in the spring constant in the left-right direction of the suspension device is not affected as much as the reduction in the spring constant in the axial direction of the bush. Therefore, according to the above configuration of the present invention, it is possible to suppress a reduction in the spring constant in the left-right direction of the suspension device.

本発明によれば、
車両の乗り心地を良くすることができ、しかも、車両の操縦安定性を良くすることができるマルチリンク式サスペンション装置を提供することができた。 According to the present invention,
It was possible to provide a multi-link suspension device that can improve the ride comfort of the vehicle and improve the steering stability of the vehicle.

以下、本発明を実施するための最良の形態を図面に基づいて説明する。図１〜図４にマルチリンク式リヤサスペンション装置１００（「サスペンション装置１００」と略称する）を示してある。このサスペンション装置１００は、車輪６０を回転自在に支持する車輪支持体６１と、一端部７１ａ，７２ａが車輪支持体６１に揺動自在に連結され、他端部７１ｂ，７２ｂがサスペンションメンバー６２（車体側部材に相当）に揺動自在に連結された前後一対のアッパーアーム７１，７２と、一端部８１ａ，８２ａが車輪支持体６１に揺動自在に連結され、他端部８１ｂ，８２ｂがサスペンションメンバー６２に揺動自在に連結された前後一対のロアアーム８１，８２と、一端部９１ａが車輪支持体６１に揺動自在に連結され、他端部９１ｂがサスペンションメンバー６２に揺動自在に連結されたトーコントロールリンク９１とを備えている。 Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. 1 to 4 show a multi-link type rear suspension device 100 (abbreviated as “suspension device 100”). In the suspension device 100, a wheel support 61 that rotatably supports a wheel 60, one end portions 71a and 72a are swingably connected to the wheel support body 61, and the other end portions 71b and 72b are suspension member 62 (vehicle body). A pair of front and rear upper arms 71 and 72, and one end portions 81a and 82a are swingably connected to the wheel support 61, and the other end portions 81b and 82b are suspension members. A pair of front and rear lower arms 81 and 82 that are swingably connected to 62, one end 91a is swingably connected to the wheel support 61, and the other end 91b is swingably connected to the suspension member 62. And a toe control link 91.

符号６３はショックアブソーバ、６４はショックアブソーバに設けられるコイルスプリング、６５は車軸、６６，６７は車軸６５に連動連結される左右の駆動シャフト、６８はブレーキ装置である。Ｆは車体前側を示している。 Reference numeral 63 is a shock absorber, 64 is a coil spring provided in the shock absorber, 65 is an axle, 66 and 67 are left and right drive shafts linked to the axle 65, and 68 is a brake device. F indicates the front side of the vehicle body.

図４に示すように、平面視において前側のロアアーム８１は、車体幅方向Ｈで車体内方側Ｈ１ほど車体前側Ｆに位置する傾斜姿勢に設定され、平面視において後側のロアアーム８２は、車体幅方向Ｈで車体内方側Ｈ１ほど車体後側Ｕに位置する傾斜姿勢に設定され、平面視においてトーコントロールリンク９１は、車体幅方向Ｈで車体内方側Ｈ１ほど車体後側Ｕに位置する傾斜姿勢に設定されている。 As shown in FIG. 4, the front lower arm 81 in the plan view is set to an inclined posture that is positioned on the vehicle front side F toward the vehicle interior side H1 in the vehicle body width direction H, and the rear lower arm 82 in the plan view is In the width direction H, the vehicle body inward side H1 is set to an inclined posture positioned on the vehicle body rear side U. In plan view, the toe control link 91 is positioned on the vehicle body inward side H1 in the vehicle body width direction H on the vehicle body rear side U. It is set to an inclined posture.

前側のロアアーム８１の他端部８１ｂとサスペンションメンバー６２とは第１防振ブッシュ１０１を介して連結し、後側のロアアーム８２の他端部８２ｂとサスペンションメンバー６２とは第２防振ブッシュ１０２を介して連結し、トーコントロールリンク９１の他端部９１ｂとサスペンションメンバー６２とは第３防振ブッシュ１０３を介して連結している。また、前側のロアアーム８１の一端部８１ａと車輪支持体６１とは第１ボールジョイント１１１を介して連結し、後側のロアアーム８２の一端部８２ａと車輪支持体６１とは第２ボールジョイント１１２を介して連結し、トーコントロールリンク９１の一端部９１ａと車輪支持体６１とは第３ボールジョイント１１３を介して連結している。 The other end 81b of the front lower arm 81 and the suspension member 62 are connected via the first vibration isolating bush 101, and the other end 82b of the rear lower arm 82 and the suspension member 62 connect the second vibration isolating bush 102. The other end 91 b of the toe control link 91 and the suspension member 62 are connected via a third vibration isolating bush 103. The one end 81a of the front lower arm 81 and the wheel support 61 are connected via the first ball joint 111, and the one end 82a of the rear lower arm 82 and the wheel support 61 connect the second ball joint 112. The one end 91a of the toe control link 91 and the wheel support 61 are connected via a third ball joint 113.

さらに、前側のアッパーアーム７１の他端部７１ｂとサスペンションメンバー６２とは第４防振ブッシュ１０４を介して連結し、後側のアッパーアーム７２の他端部７２ｂとサスペンションメンバー６２とは第５防振ブッシュ１０５を介して連結し、前側のアッパーアーム７１の一端部７１ａと車輪支持体６１とは第４ボールジョイント１１４を介して連結し、後側のアッパーアーム７２の一端部７２ａと車輪支持体６１とは第５ボールジョイント１１５を介して連結している。 Further, the other end 71b of the front upper arm 71 and the suspension member 62 are connected via the fourth vibration isolating bush 104, and the other end 72b of the rear upper arm 72 and the suspension member 62 are connected to the fifth anti-vibration bush 104. The one end 71a of the front upper arm 71 and the wheel support 61 are connected via the fourth ball joint 114, and the one end 72a of the rear upper arm 72 and the wheel support. 61 is connected via a fifth ball joint 115.

そして図４に示すように、第１防振ブッシュ１０１の軸芯ｐ１が、平面視において、前側のロアアーム８１の長手方向ｒ１と直交する方向Ｔ１に沿い、第２防振ブッシュ１０２の軸芯ｐ２が、平面視において、後側のロアアーム８２の長手方向ｒ２と直交する方向Ｔ２に沿うとともに、第３防振ブッシュ１０３の軸芯ｐ３が、平面視において、トーコントロールリンク９１の長手方向ｒ３と直交する方向Ｔ３に沿うように、第１防振ブッシュ１０１と第２防振ブッシュ１０２と第３防振ブッシュ１０３との姿勢が設定されている。また、第４防振ブッシュ１０４の軸芯ｐ４が、平面視において、前側のアッパーアーム７１の長手方向ｒ４と直交する方向Ｔ４に沿い、第５防振ブッシュ１０５の軸芯ｐ５が、平面視において、後側のアッパーアーム７２の長手方向ｒ５と直交する方向Ｔ５に沿うように、第４防振ブッシュ１０４と第５防振ブッシュ１０５との姿勢が設定されている。 As shown in FIG. 4, the shaft center p 1 of the first vibration isolation bush 101 is along the direction T 1 orthogonal to the longitudinal direction r 1 of the front lower arm 81 in a plan view, and the shaft center p 2 of the second vibration isolation bush 102. However, in plan view, it is along the direction T2 orthogonal to the longitudinal direction r2 of the rear lower arm 82, and the axial center p3 of the third vibration isolating bush 103 is orthogonal to the longitudinal direction r3 of the toe control link 91 in plan view. The postures of the first vibration isolation bush 101, the second vibration isolation bush 102, and the third vibration isolation bush 103 are set along the direction T3. Further, the shaft center p4 of the fourth vibration isolating bush 104 is along a direction T4 orthogonal to the longitudinal direction r4 of the front upper arm 71 in plan view, and the shaft core p5 of the fifth vibration isolating bush 105 is in plan view. The postures of the fourth anti-vibration bush 104 and the fifth anti-vibration bush 105 are set along the direction T5 orthogonal to the longitudinal direction r5 of the rear upper arm 72.

前記第１〜第３防振ブッシュ１０１〜１０３はいずれも同一構造であり、そのうちの一つの第１防振ブッシュ１０１の構造について詳しく説明する。
図６〜図８に示すように第１防振ブッシュ１０１は、軸部材としての内筒２と、これを取り囲むように外側に間隔をおいて配置される外筒４と、内筒２と外筒４を連結する筒状のゴム状弾性体６とからなる。内筒２は、その両端面がサスペンションメンバー６２側のブラケット１７（図５参照、ブラケット１７については後述する）に挟まれた状態でボルト固定され、外筒４は、前側のロアアーム８１等の端部の連結部（ボス）の嵌合孔に圧入される。 The first to third vibration isolation bushes 101 to 103 have the same structure, and the structure of one of the first vibration isolation bushes 101 will be described in detail.
As shown in FIGS. 6 to 8, the first anti-vibration bush 101 includes an inner cylinder 2 as a shaft member, an outer cylinder 4 disposed on the outer side so as to surround the inner cylinder 2, and the inner cylinder 2 and the outer It consists of a cylindrical rubber-like elastic body 6 that connects the cylinders 4. The inner cylinder 2 is bolted with both end faces sandwiched between brackets 17 on the suspension member 62 side (see FIG. 5; the bracket 17 will be described later), and the outer cylinder 4 is an end of the lower arm 81 and the like on the front side. It is press-fitted into the fitting hole of the connecting part (boss) of the part.

内筒２は、鋼、鉄、アルミ合金等の金属材、又は樹脂材で成る円筒状の部材であり、図６，図８に示すように、軸方向Ｊの中央部２Ｗが、径方向外方側Ｙに向けて全周に亘って膨出した球状の膨出部８に構成されている。つまり、膨出部８の外周面は凸状の球面１０に形成されている。凸状の球面１０は軸芯ｐ１上に中心Ｐを有し、球面の軸方向中央部を構成する球帯状に形成されている。外筒４は、鋼、鉄、アルミ合金等の金属材、又は樹脂材で成る円筒状の部材で、断面円形状の外形を有しており、軸方向中央部４Ｗが両端部４Ｚよりも薄肉の、外周面４ａの径が一定のストレート筒状に形成されている。 The inner cylinder 2 is a cylindrical member made of a metal material such as steel, iron, aluminum alloy, or a resin material. As shown in FIGS. 6 and 8, the central portion 2W in the axial direction J is radially outward. A spherical bulging portion 8 bulging over the entire circumference toward the side Y is configured. That is, the outer peripheral surface of the bulging portion 8 is formed as a convex spherical surface 10. The convex spherical surface 10 has a center P on the axial center p1 and is formed in a spherical belt shape constituting the axial central portion of the spherical surface. The outer cylinder 4 is a cylindrical member made of a metal material such as steel, iron, aluminum alloy, or a resin material, and has an outer shape with a circular cross section, and the axial center portion 4W is thinner than both end portions 4Z. The outer peripheral surface 4a is formed in a straight cylindrical shape having a constant diameter.

外筒４の内周面は、凸状の球面１０を取囲む軸方向中央部が、凸状の球面１０と共通の中心Ｐを持つ同芯状の凹状の球面１２に形成されている。つまり、膨出部８を囲む外筒４の内周面部分５ｂが、膨出部８の凸状の球面１０と同芯状の凹状の球面１２に形成されている。５ａは外筒４のストレート状の内周面部分である。 The inner peripheral surface of the outer cylinder 4 is formed in a concentric concave spherical surface 12 having a center P in common with the convex spherical surface 10 at the axial center portion surrounding the convex spherical surface 10. That is, the inner peripheral surface portion 5 b of the outer cylinder 4 surrounding the bulging portion 8 is formed as a concave spherical surface 12 concentric with the convex spherical surface 10 of the bulging portion 8. Reference numeral 5 a denotes a straight inner peripheral surface portion of the outer cylinder 4.

凹状の球面１２は、球面の中央部を構成する球帯状に形成されている。そして、その凹状の球面１２が設けられたことにより、上記のように、外筒４は軸方向Ｊの中央部が両端部に対して薄肉状に形成されている。絞り加工前の状態では、外筒４の内周面５の軸方向中央部は厳密な凹状の球面１２ではなく、中心Ｐが外筒４の軸芯上から軸直角方向にずれた位置関係にあり、縮径方向に絞り加工することで、中心Ｐが前記軸芯上に位置する球帯状に形成される（図６参照）。 The concave spherical surface 12 is formed in the shape of a sphere that forms the central portion of the spherical surface. Since the concave spherical surface 12 is provided, as described above, the outer cylinder 4 is formed such that the central portion in the axial direction J is thin with respect to both end portions. In the state before drawing, the central portion in the axial direction of the inner peripheral surface 5 of the outer cylinder 4 is not a strict concave spherical surface 12, but the center P is shifted from the axis of the outer cylinder 4 in the direction perpendicular to the axis. Yes, by drawing in the direction of diameter reduction, the center P is formed into a spherical band located on the axis (see FIG. 6).

外筒４の内周面５には、軸方向Ｊに延びる複数の凹溝１４が周方向Ｃに等間隔に分散して形成されており、これによって外筒４は凹溝１４が形成されている周方向位置で薄肉に設定されている。詳しくは、凹溝１４は、外筒４の内周面５において、周方向に６〜９０度毎に、かつ、溝幅Ｗよりも広い間隔Ｄをおいて配置されている。一例としては、凹溝１４は３０度毎に計１２箇所に形成されており、隣接する凹溝１４間の間隔Ｄは溝幅Ｗの２倍以上（具体的には約３倍）に設定されている。凹溝１４は１５〜４５度毎に設けるようにすることが好ましい。 A plurality of concave grooves 14 extending in the axial direction J are formed at equal intervals in the circumferential direction C on the inner peripheral surface 5 of the outer cylinder 4, thereby forming the concave grooves 14 in the outer cylinder 4. It is set to be thin at the circumferential position. Specifically, the concave grooves 14 are arranged on the inner peripheral surface 5 of the outer cylinder 4 at intervals of 6 to 90 degrees in the circumferential direction and with a gap D wider than the groove width W. As an example, the concave grooves 14 are formed at a total of 12 positions every 30 degrees, and the interval D between the adjacent concave grooves 14 is set to be twice or more (specifically, about three times) the groove width W. ing. The concave groove 14 is preferably provided every 15 to 45 degrees.

凹溝１４は、絞り加工前の形状として断面円弧状に陥没するように構成されている。また、この例では、上記のように軸方向Ｊの中央部の内周面５に凹状の球面１２を設けたことから、凹溝１４は、凹状の球面１２が設けられた部分を除くその他の軸方向部分の全体に亘って形成されている。 The concave groove 14 is configured to sink into a circular arc shape as a shape before drawing. Further, in this example, since the concave spherical surface 12 is provided on the inner peripheral surface 5 in the central portion in the axial direction J as described above, the concave groove 14 is other than the portion where the concave spherical surface 12 is provided. It is formed over the entire axial portion.

ゴム状弾性体６は、外筒４の内周面５と内筒２の外周面３とに一体に加硫接着され、内筒２の凸状の球面１０と外筒４の凹状の球面１２との間を充填するように介設されており、図６に示すように、絞り加工後の形状において、一定の肉厚を持つ球帯状に形成されている。図８に示すように、凹状の球面１２によって定められる外筒４側の仮想球面１６の軸方向Ｊの外方側Ｊ１では、内筒２と外筒４との間にゴム状弾性体６が充填されないように形成されている。軸方向外方側Ｊ１において内筒２の外周面３と外筒４の内周面５には、ゴム状弾性体６から連なる薄肉状のゴム膜１８が形成されている。 The rubber-like elastic body 6 is integrally vulcanized and bonded to the inner peripheral surface 5 of the outer cylinder 4 and the outer peripheral surface 3 of the inner cylinder 2, and the convex spherical surface 10 of the inner cylinder 2 and the concave spherical surface 12 of the outer cylinder 4. As shown in FIG. 6, the shape after drawing is formed in a spherical band shape having a certain thickness. As shown in FIG. 8, on the outer side J 1 in the axial direction J of the virtual spherical surface 16 on the outer cylinder 4 side defined by the concave spherical surface 12, the rubber-like elastic body 6 is interposed between the inner cylinder 2 and the outer cylinder 4. It is formed so as not to be filled. A thin rubber film 18 connected to the rubber-like elastic body 6 is formed on the outer peripheral surface 3 of the inner cylinder 2 and the inner peripheral surface 5 of the outer cylinder 4 on the axially outer side J1.

第１防振ブッシュ１０１を製造するに際しては、外筒４の凹状の球面１２と内筒２の凸状の球面１０とをそれぞれ形成した上で、それら両筒を成形型（図示せず）に配置し、その成形型内にゴム材料を注入することでゴム状弾性体６を加硫成形するとともに、内筒２の外周面３と外筒４の内周面５にゴム状弾性体６を一体に加硫接着させる。これにより、絞り加工前の加硫成形体が得られる。この加硫成形体において、外筒４の凹溝１４内にはゴム状弾性体６が入り込んでおり、凹溝１４内でもゴム状弾性体６が外筒４の内周面５に加硫接着され、接着強度が高められている。 When manufacturing the first anti-vibration bush 101, the concave spherical surface 12 of the outer cylinder 4 and the convex spherical surface 10 of the inner cylinder 2 are respectively formed, and then both the cylinders are formed into a molding die (not shown). The rubber-like elastic body 6 is vulcanized and molded by pouring a rubber material into the mold, and the rubber-like elastic body 6 is attached to the outer peripheral surface 3 of the inner cylinder 2 and the inner peripheral surface 5 of the outer cylinder 4. Vulcanize and bond together. Thereby, the vulcanized molded body before drawing is obtained. In this vulcanized molded body, the rubber-like elastic body 6 is inserted into the concave groove 14 of the outer cylinder 4, and the rubber-like elastic body 6 is vulcanized and bonded to the inner peripheral surface 5 of the outer cylinder 4 even in the concave groove 14. As a result, the adhesive strength is increased.

次に上記加硫形成体に絞り加工が施される。絞り加工は、図示は省略するが、放射状に複数に分割されたダイス片を持つダイスを用いて行われる。ダイスは、例えば外筒４の凹溝１４と同数の１２個に分割されており、各ダイス片の周方向中央に凹溝１４が位置するようにセットして、ダイス片を径内方に移動させることにより、外筒１４が縮径方向に絞り加工される。凹溝１４は、絞り加工後においても完全につぶれることはなく、凹溝１４内にゴム状弾性体６が入り込んだ状態で残っている。外筒４の内周面５に複数の凹溝１４を設けてあるから絞り加工をしやすくすることができる。 Next, the vulcanized product is drawn. Although drawing is omitted, the drawing process is performed using a die having dice pieces that are radially divided. The dice are divided into, for example, twelve grooves of the same number as the concave grooves 14 of the outer cylinder 4 and set so that the concave grooves 14 are positioned in the center in the circumferential direction of each die piece, and the die pieces are moved inward in the diameter. By doing so, the outer cylinder 14 is drawn in the diameter reducing direction. The concave groove 14 is not completely crushed even after the drawing process, and remains in a state in which the rubber-like elastic body 6 enters the concave groove 14. Since a plurality of concave grooves 14 are provided on the inner peripheral surface 5 of the outer cylinder 4, drawing can be facilitated.

内筒２及び外筒４の軸方向Ｊに沿う断面において、凹状の球面１２によって定められる仮想球面１６と、凸状の球面１０によって定められる仮想球面３６との間のゴム状弾性体部分６ａの周方向の両端部６Ｔに、内筒２と、外筒４の軸方向Ｊの両端部４Ｚとの間で露出した円弧状の一対の開放端面３７が各別に形成されている。 In the cross section along the axial direction J of the inner cylinder 2 and the outer cylinder 4, the rubber-like elastic body portion 6a between the virtual spherical surface 16 defined by the concave spherical surface 12 and the virtual spherical surface 36 defined by the convex spherical surface 10 is obtained. A pair of arc-shaped open end surfaces 37 exposed between the inner tube 2 and both end portions 4Z in the axial direction J of the outer tube 4 are formed on both end portions 6T in the circumferential direction.

前記第４防振ブッシュ１０４と第５防振ブッシュ１０５は同一構造であり、図１１に示すように、軸部材としての内筒５２と、外筒５４と、両者を連結するゴム状弾性体５６とから成り、内外筒ともに径が一定のストレート筒状に形成されている（前記第４防振ブッシュ１０４と第５防振ブッシュ１０５を第１〜第３防振ブッシュ１０１〜１０３と同一構造に構成してあってもよい）。 The fourth anti-vibration bush 104 and the fifth anti-vibration bush 105 have the same structure, and as shown in FIG. 11, an inner cylinder 52 as an axial member, an outer cylinder 54, and a rubber-like elastic body 56 that connects the two. The inner and outer cylinders are formed in a straight cylinder shape with a constant diameter (the fourth vibration isolating bush 104 and the fifth anti vibration bush 105 have the same structure as the first to third vibration isolating bushes 101 to 103. May be configured).

次に、ブッシュの車体側における取付構造について説明する。第１〜第５防振ブッシュ１０１〜１０５ともサスペンションメンバー６２への取付構造は同一である。図５に示すように、第１防振ブッシュ１０１の外筒４が、前側のロアアーム８１の車体側の連結部であるボス１１０の嵌合孔に圧入される。そして第１防振ブッシュ１０１がサスペンションメンバー６２に固着されているブラケット１７にボルト固定される。 Next, the mounting structure on the vehicle body side of the bush will be described. The first to fifth anti-vibration bushes 101 to 105 have the same mounting structure to the suspension member 62. As shown in FIG. 5, the outer cylinder 4 of the first anti-vibration bush 101 is press-fitted into a fitting hole of a boss 110 that is a connecting portion on the vehicle body side of the front lower arm 81. The first vibration isolating bush 101 is bolted to the bracket 17 fixed to the suspension member 62.

詳しくは、サスペンションメンバー６２にコの字状のブラケット１７が溶接固着されており、そのブラケット１７の一対の取付片１７ａで内筒２が両側から挟み込まれている。その状態で、一対の取付片１７ａのボルト挿通孔と内筒２とにボルト２０が挿通され、ボルト２０にナットが螺合締結されている。仮想線で示すように、各取付片１７ａ，１７ａと側面とサスペンションメンバー６２に跨って補強部材１７ｂを固着しても良い。 Specifically, a U-shaped bracket 17 is fixed to the suspension member 62 by welding, and the inner cylinder 2 is sandwiched from both sides by a pair of mounting pieces 17 a of the bracket 17. In this state, the bolt 20 is inserted into the bolt insertion hole of the pair of attachment pieces 17 a and the inner cylinder 2, and a nut is screwed and fastened to the bolt 20. As indicated by phantom lines, the reinforcing member 17b may be fixed across the attachment pieces 17a, 17a, the side surfaces, and the suspension member 62.

本発明者は、上記の構造のサスペンション装置１００と、従来例と、比較例１〜比較例３とのサスペンション装置を後述のサスペンション耐久試験機を用いて試験した。従来例とは、本発明の第１〜第５防振ブッシュ１０１〜１０５に対応する防振ブッシュが、図１１に示す構造の防振ブッシュで構成されたサスペンション装置であり、その他の構造は本発明の構造と同じである。図１１に示す構造の防振ブッシュは、軸部材としての内筒５２と、外筒５４と、両者を連結するゴム状弾性体５６とから成り、内外筒５２，５４ともに径が一定のストレート筒状に形成されている。 The inventor tested the suspension apparatus 100 having the above-described structure, the conventional example, and the suspension apparatuses of Comparative Examples 1 to 3 using a suspension durability tester described later. The conventional example is a suspension device in which the anti-vibration bushes corresponding to the first to fifth anti-vibration bushes 101 to 105 of the present invention are constituted by the anti-vibration bushes having the structure shown in FIG. It is the same as the structure of the invention. The anti-vibration bush having the structure shown in FIG. 11 includes an inner cylinder 52 as an axial member, an outer cylinder 54, and a rubber-like elastic body 56 that couples both, and both the inner and outer cylinders 52, 54 have straight diameters. It is formed in a shape.

比較例１とは、本発明の第１防振ブッシュ１０１に対応する防振ブッシュが、図９に示す構造の防振ブッシュで構成されたサスペンション装置、比較例２とは、本発明の第２防振ブッシュ１０２に対応する防振ブッシュが、図９に示す構造の防振ブッシュで構成されたサスペンション装置、比較例３とは、本発明の第１防振ブッシュ１０１に対応する防振ブッシュと第２防振ブッシュ１０２に対応する防振ブッシュとが、図９に示す構造の防振ブッシュで構成されたサスペンション装置である。比較例１〜比較例３のいずれもその他の構造は本発明の上記構造と同じである。 Comparative Example 1 is a suspension device in which the vibration isolating bush corresponding to the first anti-vibration bushing 101 of the present invention is composed of the anti-vibration bush having the structure shown in FIG. 9, and Comparative Example 2 is the second of the present invention. The suspension device in which the vibration isolating bush corresponding to the vibration isolating bush 102 is configured by the anti-vibration bush having the structure shown in FIG. 9 and Comparative Example 3 are the vibration isolating bush corresponding to the first anti-vibration bush 101 of the present invention and The anti-vibration bush corresponding to the second anti-vibration bush 102 is a suspension device constituted by the anti-vibration bush having the structure shown in FIG. In all of Comparative Examples 1 to 3, the other structures are the same as the above-described structure of the present invention.

図９に示す防振ブッシュの構造について説明すると、本発明の上記の実施形態の構造（第１防振ブッシュ１０１の構造）に加え、内筒２と外筒４の間に位置する中間筒３８を備えて、ゴム状弾性体６が、内筒２と中間筒３８を連結する内側ゴム状弾性体部分６Ａと、中間筒３８と外筒４を連結する外側ゴム状弾性体部分６Ｂとで構成されている。中間筒３８は内筒２や外筒４よりも薄肉で、その中間筒３８の軸方向Ｊの中央部が、径方向外方側Ｙに膨出した球状の中間筒側膨出部３９に構成されて、中間筒側膨出部３９の外周面が、内筒２の膨出部８の凸状の球面１０と同芯状の凸状の球面３９Ａに形成されるとともに、中間筒側膨出部３９の内周面が、内筒２の膨出部８の凸状の球面１０と同芯状の凹状の球面３９Ｂに形成されている。各凸状の球面１０，３９Ａ、及び、各凹状の球面１２，３９Ｂの共通の軸芯Ｐは内筒２の軸芯ｐ３上に位置する。この構造の第３防振ブッシュ１０３は中間筒３８を備えていない上記の実施形態の第１〜第３防振ブッシュ１０１〜１０３に比べると、ねじり方向Ｎのばね定数、及び軸方向のばね定数Ｊが小さくなっている。 The structure of the anti-vibration bush shown in FIG. 9 will be described. In addition to the structure of the above embodiment of the present invention (the structure of the first anti-vibration bush 101), the intermediate cylinder 38 positioned between the inner cylinder 2 and the outer cylinder 4 is described. The rubber-like elastic body 6 includes an inner rubber-like elastic body portion 6A that connects the inner cylinder 2 and the intermediate cylinder 38, and an outer rubber-like elastic body portion 6B that connects the intermediate cylinder 38 and the outer cylinder 4. Has been. The intermediate cylinder 38 is thinner than the inner cylinder 2 and the outer cylinder 4, and the central portion in the axial direction J of the intermediate cylinder 38 is configured as a spherical intermediate cylinder side bulging portion 39 that bulges radially outward Y. Then, the outer peripheral surface of the intermediate cylinder side bulging portion 39 is formed into a convex spherical surface 39A concentric with the convex spherical surface 10 of the bulging portion 8 of the inner cylinder 2, and the intermediate cylinder side bulging portion The inner peripheral surface of the portion 39 is formed as a concave spherical surface 39B concentric with the convex spherical surface 10 of the bulging portion 8 of the inner cylinder 2. A common axis P of each convex spherical surface 10, 39 A and each concave spherical surface 12, 39 B is located on the axial core p 3 of the inner cylinder 2. Compared to the first to third vibration isolating bushes 101 to 103 of the above-described embodiment in which the third vibration isolating bush 103 having this structure is not provided with the intermediate cylinder 38, the spring constant in the torsional direction N and the spring constant in the axial direction. J is smaller.

試験機は、（株）鷺宮製作所製の「サスペンションＡＳＳＹ耐久試験機」（型式番号Ｖ２４４７）であり、図１０に示すデータ図表に示す試験結果を得た。また本発明者は、テストドライバーによる官能試験も行った。その官能試験においては、１０点満点のうちの８点以上を◎、６〜７点を○、４〜５を△、３点以下を×として評価し、図１０に示すデータ図表に示した。試験における各ばね定数は、ショックアブソーバ６３からコイルスプリング６４を取り外した状態で計測されたものであり、各アーム・リンクとその周りの連結部（各防振ブッシュやボールジョイント）によって決まるサスペンション装置１００のばね定数である。 The tester was “Suspension ASSY Endurance Tester” (model number V2447) manufactured by Kashiwamiya Seisakusho Co., Ltd., and the test results shown in the data chart shown in FIG. 10 were obtained. The inventor also performed a sensory test with a test driver. In the sensory test, 8 points or more out of 10 points were evaluated as ◎, 6-7 points as ◯, 4-5 as △, 3 points or less as x, and shown in the data chart shown in FIG. Each spring constant in the test is measured with the coil spring 64 removed from the shock absorber 63, and the suspension device 100 is determined by each arm / link and the connecting portion (each anti-vibration bush or ball joint) around the arm / link. Of the spring constant.

サスペンション装置１００を上下に振動させているときは前後左右はフリー（荷重をかけていない）であり、前後に振動させているときは上下左右はフリーであり、左右に振動させているときは上下前後はフリーである。前後に振動させているときと、左右に振動させているときは、上下には変位させない。前後に加振する場合、プラスマイナス１５００Ｎの力を加える。すなわち、基準点（自由状態における静止点）から一方向に１５００Ｎを作用させ、その反動で基準点に戻ってきたら逆方向に１５００Ｎを作用させる。左右に加振する場合、同様の方法でプラスマイナス３０００Ｎの力を加える。上下に加振する場合、プラスマイナス５０ｍｍ変位させる。 When the suspension device 100 is vibrated up and down, the front and rear and left and right are free (no load is applied), when vibrated back and forth, the top and bottom and left and right are free, and when vibrated left and right, the top and bottom Before and after are free. When oscillating back and forth and when oscillating left and right, it is not displaced up and down. When vibrating back and forth, a force of plus or minus 1500N is applied. That is, 1500N is applied in one direction from the reference point (free state stationary point), and when the reaction returns to the reference point, 1500N is applied in the opposite direction. When oscillating left and right, a force of plus or minus 3000 N is applied in the same manner. When vibrating up and down, it is displaced by plus or minus 50 mm.

図１０において、本発明によるサスペンション装置１００の各ばね定数は、従来例の構造を基準（０％）とした場合の相対的な比率として表している。図１０に示すように、サスペンション装置１００の上下方向のばね定数は、従来例に比べて８．９％小さくなっていることを示している。そして、サスペンション装置１００の前後方向のばね定数は、従来例に比べて４．４％小さくなっていることを示しており、サスペンション装置１００の左右方向のばね定数は、従来例に比べて１．９％大きくなっていることを示している。 In FIG. 10, each spring constant of the suspension device 100 according to the present invention is expressed as a relative ratio when the structure of the conventional example is used as a reference (0%). As shown in FIG. 10, the vertical spring constant of the suspension device 100 is 8.9% smaller than that of the conventional example. The spring constant in the front-rear direction of the suspension device 100 is 4.4% smaller than that in the conventional example, and the spring constant in the left-right direction of the suspension device 100 is 1. It is 9% larger.

本発明によるサスペンション装置１００では、比較例１や比較例２に比べると、上下方向のばね定数及び前後方向のばね定数をより小さくすることができ、左右方向のばね定数をより大きくすることができている。また比較例３に比べると、前後方向のばね定数をより小さくすることができ、左右方向のばね定数をより大きくすることができている。比較例１〜比較例３との試験結果の違いは次の理由による。 In the suspension device 100 according to the present invention, the spring constant in the up-down direction and the spring constant in the front-rear direction can be made smaller and the spring constant in the left-right direction can be made larger than in Comparative Example 1 and Comparative Example 2. ing. Compared to Comparative Example 3, the spring constant in the front-rear direction can be made smaller, and the spring constant in the left-right direction can be made larger. The difference between the test results of Comparative Examples 1 to 3 is as follows.

すなわち、図９に示す構造の防振ブッシュ（以下、「中間筒付きの防振ブッシュ」と称する）は、中間筒３８を備えていることから軸直角方向のばね定数を大きくすることができる。従って、中間筒付きの防振ブッシュの軸直角方向のばね定数と、中間筒３８を備えていない防振ブッシュの軸直角方向のばね定数とを同じに設定した場合、中間筒付きの防振ブッシュのゴム状弾性体を、より軟らかく設定することができる。これにより、中間筒付きの防振ブッシュのねじり方向Ｎのばね定数、及び、軸方向Ｊのばね定数が小さくなる。各防振ブッシュの平面視における姿勢は前述した通りであり、中間筒付きの防振ブッシュの軸方向Ｊのばね定数が小さくなったことで、中間筒付きの防振ブッシュを備えた比較例１〜比較例３では、サスペンション装置の左右方向のばね定数を（本発明の上記構造に比べると）上げることができないが、本発明の上記構造によれば、比較例１〜比較例３よりも軸方向Ｊのばね定数を上げることができて、サスペンション装置１００の左右方向のばね定数を上げることができる。 That is, the anti-vibration bushing having the structure shown in FIG. 9 (hereinafter referred to as “vibration-proof bushing with an intermediate cylinder”) includes the intermediate cylinder 38, so that the spring constant in the direction perpendicular to the axis can be increased. Therefore, when the spring constant in the direction perpendicular to the axis of the vibration isolating bush with the intermediate cylinder and the spring constant in the axis orthogonal direction of the vibration isolating bush without the intermediate cylinder 38 are set to be the same, the vibration isolating bush with the intermediate cylinder is set. This rubber-like elastic body can be set softer. As a result, the spring constant in the torsional direction N and the spring constant in the axial direction J of the anti-vibration bush with the intermediate cylinder are reduced. The posture of each vibration isolating bush in plan view is as described above, and the spring constant in the axial direction J of the anti-vibration bush with the intermediate cylinder is reduced, so that Comparative Example 1 including the anti-vibration bush with the intermediate cylinder is provided. In Comparative Example 3, the left and right spring constant of the suspension device cannot be increased (compared to the above-described structure of the present invention). However, according to the above structure of the present invention, the shaft is greater than in Comparative Examples 1 to 3. The spring constant in the direction J can be increased, and the spring constant in the left-right direction of the suspension device 100 can be increased.

つまり、この耐久試験結果から、上下及び前後方向にはばね定数が柔らかい、即ちソフトな乗り心地を提供しながらも、旋回走行等への影響が強い左右方向のばね定数は硬い、即ち踏ん張りの効いて（腰のある）操縦安定性に優れるサスペンション装置であることが示されている。試験結果は、テストドライバーによる評価とも一致しており、本発明によるサスペンション装置の良さが、データ（図１０）及びドライバーの感覚の双方から立証されている。
［別実施形態］ That is, from the endurance test results, the spring constant in the vertical direction and the front-rear direction is soft, that is, it provides a soft riding comfort, but the spring constant in the left-right direction, which has a strong influence on turning, etc. It has been shown that it is a suspension device that has excellent handling stability (with waist). The test results are consistent with the evaluation by the test driver, and the goodness of the suspension device according to the present invention is proved from both the data (FIG. 10) and the driver's feeling.
[Another embodiment]

本実施形態では、上記の第１実施形態の第３防振ブッシュ１０３を次のように構成してある。すなわち図９に示すように、上記の第１実施形態の構造（第１実施形態の第３防振ブッシュ１０３の構造）に加え、内筒２と外筒４の間に位置する中間筒３８を備えて、ゴム状弾性体６が、内筒２と中間筒３８を連結する内側ゴム状弾性体部分６Ａと、中間筒３８と外筒４を連結する外側ゴム状弾性体部分６Ｂとで構成されている。中間筒３８は内筒２や外筒４よりも薄肉で、その中間筒３８の軸方向Ｊの中央部が、径方向外方側Ｙに膨出した球状の中間筒側膨出部３９に構成されて、中間筒側膨出部３９の外周面が、内筒２の膨出部８の凸状の球面１０と同芯状の凸状の球面３９Ａに形成されるとともに、中間筒側膨出部３９の内周面が、内筒２の膨出部８の凸状の球面１０と同芯状の凹状の球面３９Ｂに形成されている。各凸状の球面１０，３９Ａ、及び、各凹状の球面１２，３９Ｂの共通の軸芯Ｐは内筒２の軸芯ｐ３上に位置する。この構造の第３防振ブッシュ１０３は中間筒３８を備えていない第１の実施形態の第１〜第３防振ブッシュ１０１〜１０３に比べると、ねじり方向Ｎのばね定数、及び軸方向のばね定数Ｊが小さくなっている。 In the present embodiment, the third anti-vibration bush 103 of the first embodiment is configured as follows. That is, as shown in FIG. 9, in addition to the structure of the first embodiment (the structure of the third vibration isolating bush 103 of the first embodiment), an intermediate cylinder 38 positioned between the inner cylinder 2 and the outer cylinder 4 is provided. The rubber-like elastic body 6 includes an inner rubber-like elastic body portion 6A that connects the inner cylinder 2 and the intermediate cylinder 38, and an outer rubber-like elastic body portion 6B that connects the intermediate cylinder 38 and the outer cylinder 4. ing. The intermediate cylinder 38 is thinner than the inner cylinder 2 and the outer cylinder 4, and the central portion in the axial direction J of the intermediate cylinder 38 is configured as a spherical intermediate cylinder side bulging portion 39 that bulges radially outward Y. Then, the outer peripheral surface of the intermediate cylinder side bulging portion 39 is formed into a convex spherical surface 39A concentric with the convex spherical surface 10 of the bulging portion 8 of the inner cylinder 2, and the intermediate cylinder side bulging portion The inner peripheral surface of the portion 39 is formed as a concave spherical surface 39B concentric with the convex spherical surface 10 of the bulging portion 8 of the inner cylinder 2. A common axis P of each convex spherical surface 10, 39 A and each concave spherical surface 12, 39 B is located on the axial core p 3 of the inner cylinder 2. Compared with the first to third vibration isolating bushes 101 to 103 of the first embodiment in which the third vibration isolating bush 103 having this structure is not provided with the intermediate cylinder 38, the spring constant in the torsional direction N and the spring in the axial direction. The constant J is small.

マルチリンク式サスペンション装置を示す斜視図Perspective view showing a multi-link suspension device 図１の左側のマルチリンク式サスペンション装置を示す背面図The rear view which shows the multilink type suspension apparatus of the left side of FIG. 図２のマルチリンク式サスペンション装置を内側からみた側面図Side view of the multi-link suspension device of FIG. 2 as seen from the inside 図２のマルチリンク式サスペンション装置の平面図Plan view of the multi-link suspension device of FIG. ブッシュの取付構造を示す断面図Sectional view showing bush mounting structure 第１〜第３防振ブッシュの構造を示す縦断面図A longitudinal sectional view showing the structure of the first to third vibration-proof bushings 第１〜第３防振ブッシュの側面図Side view of first to third anti-vibration bushes 第１〜第３防振ブッシュの要部を示す拡大縦断面図Enlarged longitudinal sectional view showing the main part of the first to third anti-vibration bushings 別実施形態の第３防振ブッシュの構造を示す縦断面図Longitudinal sectional view showing the structure of the third anti-vibration bush of another embodiment マルチリンク式サスペンション装置の性能評価試験結果を示すデータ図表Data chart showing performance evaluation test results of multi-link suspension system 従来の防振ブッシュの構造を示す断面図Sectional view showing the structure of a conventional anti-vibration bush 従来の防振ブッシュの構造を示す断面図Sectional view showing the structure of a conventional anti-vibration bush

Explanation of symbols

２軸部材（内筒）
２Ｗ軸方向の中央部（内筒の軸方向の中央部）
３外周面（内筒の外周面）
４外筒
４ａ外周面（外筒の外周面）
４Ｗ軸方向中央部（外筒の軸方向中央部）
４Ｚ両端部（外筒の両端部）
５内周面（外筒の内周面）
５ａ外筒のストレート状の内周面部分
５ｂ内周面部分
６ゴム状弾性体
６ａゴム状弾性体部分（両仮想球面の間のゴム状弾性体部分）
６Ａ内側ゴム状弾性体部分
６Ｂ外側ゴム状弾性体部分
６Ｔ周方向の両端部
８膨出部（内筒の膨出部）
１０凸状の球面（軸部材の凸状の球面）
１２凹状の球面（外筒の凹状の球面）
１４凹溝
１６仮想球面（凹側）
１７ブラケット
１７ａ取付片
１７ｂ補強部材
１８ゴム膜
２０ボルト
３６仮想球面（凸側）
３７開放端面
３８中間筒
３９中間筒側膨出部（中間筒の軸方向の中央部）
３９Ａ凸状の球面（中間筒側膨出部の外周面）
３９Ｂ凹状の球面（中間筒側膨出部の内周面）
５２従来技術の内筒
５４従来技術の外筒
５６従来技術のゴム状弾性体
６０車輪
６１車輪支持体
６２車体側部材（サスペンションメンバー）
６３ショックアブソーバ
６４コイルスプリング
６５車軸
６６，６７駆動シャフト
６８ブレーキ装置
７１アッパーアーム（前側のアッパーアーム）
７１ａ一端部（前側のアッパーアームの一端部）
７１ｂ他端部（前側のアッパーアームの他端部）
７２アッパーアーム（後側のアッパーアーム）
７２ａ一端部（後側のアッパーアームの一端部）
７２ｂ他端部（後側のアッパーアームの他端部）
８１ロアアーム（前側のロアアーム）
８１ａ一端部（前側のロアアームの一端部）
８１ｂ他端部（前側のロアアームの他端部）
８２ロアアーム（後側のロアアーム）
８２ａ一端部（後側のロアアームの一端部）
８２ｂ他端部（後側のロアアームの他端部）
９１トーコントロールリンク
９１ａ一端部（トーコントロールリンクの一端部）
９１ｂ他端部（トーコントロールリンクの他端部）
１００マルチリンク式サスペンション装置
１０１第１防振ブッシュ
１０２第２防振ブッシュ
１０３第３防振ブッシュ
１０４第４防振ブッシュ
１０５第５防振ブッシュ
１１０ボス
１１１第１ボールジョイント
１１２第２ボールジョイント
１１３第３ボールジョイント
１１４第４ボールジョイント
１１５第５ボールジョイント
Ｃ周方向
Ｄ間隔
Ｆ車体の前側
Ｈ車体幅方向
Ｈ１車体内方側
Ｕ車体後側
Ｊ軸方向
Ｊ１軸方向外方側
Ｋ軸直角方向
Ｎねじり方向
Ｐ中心
ｐ１第１防振ブッシュの軸芯
ｐ２第２防振ブッシュの軸芯
ｐ３第３防振ブッシュの軸芯
ｐ４第４防振ブッシュの軸芯
ｐ５第５防振ブッシュの軸芯
ｒ１前側のロアアームの長手方向
Ｔ１前側のロアアームの長手方向と直交する方向
ｒ２後側のロアアームの長手方向
Ｔ２後側のロアアームの長手方向と直交する方向
ｒ３トーコントロールリンクの長手方向
Ｔ３トーコントロールリンクの長手方向と直交する方向
ｒ４前側のアッパーアームの長手方向
Ｔ４前側のアッパーアームの長手方向と直交する方向
ｒ５後側のアッパーアームの長手方向
Ｔ５後側のアッパーアームの長手方向と直交する方向
Ｗ溝幅
Ｙ径方向外方側
Ｚこじり方向 2 Shaft member (inner cylinder)
2W Axis center (center part of the inner cylinder in the axial direction)
3 outer peripheral surface (the outer peripheral surface of the inner cylinder)
4 outer cylinder 4a outer peripheral surface (outer peripheral surface of outer cylinder)
4W Axial central part (axial central part of outer cylinder)
4Z Both ends (both ends of the outer cylinder)
5 Inner peripheral surface (inner peripheral surface of outer cylinder)
5a Straight outer peripheral surface portion 5b of the outer cylinder Inner peripheral surface portion 6 Rubber elastic body 6a Rubber elastic body portion (rubber elastic body portion between both virtual spherical surfaces)
6A Inner rubber-like elastic body part 6B Outer rubber-like elastic body part 6T Both ends 8 in the circumferential direction Swelling part (swelling part of inner cylinder)
10 Convex spherical surface (the convex spherical surface of the shaft member)
12 concave spherical surface (concave spherical surface of outer cylinder)
14 Concave groove 16 Virtual spherical surface (concave side)
17 Bracket 17a Mounting piece 17b Reinforcing member 18 Rubber film 20 Bolt 36 Virtual spherical surface (convex side)
37 Open end face 38 Intermediate cylinder 39 Intermediate cylinder side bulging part (Axial central part of the intermediate cylinder)
39A Convex spherical surface (outer peripheral surface of bulging portion on the intermediate cylinder side)
39B concave spherical surface (inner peripheral surface of the bulging portion on the intermediate cylinder side)
52 Conventional inner cylinder 54 Conventional outer cylinder 56 Conventional rubber elastic body 60 Wheel 61 Wheel support body 62 Car body side member (suspension member)
63 Shock absorber 64 Coil spring 65 Axle 66, 67 Drive shaft 68 Brake device 71 Upper arm (front upper arm)
71a One end (one end of the front upper arm)
71b The other end (the other end of the front upper arm)
72 Upper arm (rear upper arm)
72a One end (one end of the rear upper arm)
72b The other end (the other end of the rear upper arm)
81 Lower arm (front lower arm)
81a One end (one end of the front lower arm)
81b The other end (the other end of the lower arm on the front side)
82 Lower arm (lower rear arm)
82a One end (one end of the rear lower arm)
82b The other end (the other end of the lower lower arm)
91 Toe control link 91a One end (one end of the toe control link)
91b The other end (the other end of the toe control link)
100 Multi-link suspension device 101 First vibration isolation bush 102 Second vibration isolation bush 103 Third vibration isolation bush 104 Fourth vibration isolation bush 105 Fifth vibration isolation bush 110 Boss 111 First ball joint 112 Second ball joint 113 Three-ball joint 114 Fourth ball joint 115 Fifth ball joint C Circumferential direction D Interval F Front side of vehicle body H Body width direction H1 Vehicle body inner side U Vehicle body rear side J Axial direction J1 Axial direction outward side K Axis perpendicular direction N Torsion Direction P Center p1 Axial core p1 of the first anti-vibration bushing Axial core p2 of the second anti-vibration bushing p3 Axial core of the third anti-vibration bushing p4 Axial core of the fourth anti-vibration bushing p5 Axial core r1 of the fifth anti-vibration bushing Longitudinal direction T1 of the lower arm in the direction r2 orthogonal to the longitudinal direction of the lower arm on the front side. A direction r3 perpendicular to the longitudinal direction of the lower arm of the toe A longitudinal direction T3 of the toe control link A direction r4 perpendicular to the longitudinal direction of the toe control link A longitudinal direction T4 of the front upper arm r5 A direction r5 perpendicular to the longitudinal direction of the front upper arm Longitudinal direction T5 of the upper arm in the direction W perpendicular to the longitudinal direction of the rear upper arm W Groove width Y Radially outward side Z

Claims

A wheel support for rotatably supporting the wheel;
A pair of front and rear upper arms whose one end is swingably connected to the wheel support and whose other end is swingably connected to the vehicle body member;
A pair of front and rear lower arms, one end of which is swingably connected to the wheel support and the other end is swingably connected to the vehicle body side member;
A toe control link having one end portion swingably connected to the wheel support and the other end portion swingably connected to the vehicle body side member;
In the plan view, the front lower arm is set in an inclined posture that is located on the front side of the vehicle body in the vehicle width direction. In the plan view, the rear lower arm is in the rear side of the vehicle body in the vehicle width direction. In the plan view, the toe control link is set to an inclined posture that is positioned closer to the rear side of the vehicle body in the vehicle body width direction and the toe control link with respect to the vehicle body width direction. An inclination angle in a plan view of the front lower arm with respect to the vehicle body width direction is set smaller than an inclination angle in a plan view of the front lower arm with respect to the vehicle body width direction,
The other end portion of the front lower arm and the vehicle body side member are connected via a first vibration isolation bush, and the other end portion of the rear lower arm and the vehicle body side member are connected via a second vibration isolation bush. Connecting, the other end of the toe control link and the vehicle body side member are connected via a third anti-vibration bush,
The axial center of the first anti-vibration bush is along a direction orthogonal to the longitudinal direction of the front lower arm in plan view, and the axial center of the second anti-vibration bush is in the plan view of the rear lower arm. The first anti-vibration bush and the second anti-vibration bush and the second anti-vibration bush so that the axial center of the third anti-vibration bush is along the direction perpendicular to the longitudinal direction of the toe control link in plan view. A multi-link suspension device in which a vibration isolation bush and a third vibration isolation bush are arranged,
The first vibration isolation bush, the second vibration isolation bush, and the third vibration isolation bush include a shaft member, an outer cylinder that surrounds the shaft member, and a rubber-like elastic body that connects the shaft member and the outer cylinder. The axial central portion of the shaft member is configured as a spherical bulging portion bulging radially outward, and an inner peripheral surface portion of the outer cylinder surrounding the bulging portion is the bulging portion. It is formed into a concave spherical surface that is concentric with the convex spherical surface of the protruding portion ,
Of the first vibration isolation bush, the second vibration isolation bush, and the third vibration isolation bush, only the third vibration isolation bush further includes an intermediate cylinder positioned between the shaft member and the outer cylinder, and the rubber A cylindrical elastic body is composed of an inner rubber-like elastic body portion that connects the shaft member and the intermediate cylinder, and an outer rubber-like elastic body portion that connects the intermediate cylinder and the outer cylinder, and is the center in the axial direction of the intermediate cylinder And the outer peripheral surface of the bulging portion of the intermediate cylinder side is a convex spherical surface of the bulging portion of the shaft member. A concentric convex spherical surface is formed, and an inner circumferential surface of the intermediate cylinder side bulging portion is formed as a concentric concave spherical surface with a convex spherical surface of the bulging portion of the shaft member. ,
The third vibration isolation bushing is a multi-link suspension device in which the spring constant in the torsional direction and the spring constant in the axial direction are set to be smaller than those of the first vibration isolation bushing and the second vibration isolation bushing .

In the cross section along the axial direction of the shaft member and the outer cylinder, both ends in the circumferential direction of the rubber-like elastic body portion between the virtual spherical surface defined by the concave spherical surface and the virtual spherical surface defined by the convex spherical surface In addition, a pair of arc-shaped open end surfaces exposed between the shaft member and both end portions in the axial direction of the outer cylinder are formed separately, and the outer cylinder has a thinner central portion in the axial direction than both end portions. The multi-link suspension device according to claim 1, wherein the outer peripheral surface is formed in a straight cylindrical shape having a constant diameter.