JP2008169914A

JP2008169914A - Vibration isolation device

Info

Publication number: JP2008169914A
Application number: JP2007003534A
Authority: JP
Inventors: Masato Hatano; 正人羽田野
Original assignee: Toyo Tire and Rubber Co Ltd
Current assignee: Toyo Tire Corp
Priority date: 2007-01-11
Filing date: 2007-01-11
Publication date: 2008-07-24

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolation device capable of sufficiently securing the degree of freedom of the tuning of a spring characteristic in a direction orthogonal to an axis, and exerting excellent durability by preventing the occurrence of a crack of a rubber-like elastic body. <P>SOLUTION: This vibration isolation device is provided with: an inner pipe 2; an outer pipe 3 surrounding the inner pipe 2 in parallel with the axis thereof; the rubber-like elastic body 4 connecting the inner pipe 2 to the outer pipe 3; a pair of bored parts 5 positioned by interposing the inner pipe 2 therebetween; and an annular projecting part 7 projecting from a circumferential surface at the axial center of the inner pipe 2 to the outside in the radial direction. The annular projecting part 7 includes: a pair of first parts 71 projecting in a first direction RD1 orthogonal to the axis, and facing the bored parts 5; a pair of second parts 72 projecting in a second direction RD2 perpendicular to the first direction and orthogonal to the axis; and third parts 73 recessed inward in the radial direction by reducing a projecting height relative to the first parts 71 and the second parts 72, and interposed between the first parts 71 and the second parts 72 to connect them to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、内筒と、内筒を軸平行に取り囲む外筒と、両者を連結するゴム状弾性体とを備える防振装置に関する。 The present invention relates to a vibration isolator that includes an inner cylinder, an outer cylinder that surrounds the inner cylinder in an axially parallel manner, and a rubber-like elastic body that connects the two.

かかる防振装置の一例を図４に示す。図５は、図４のＢ−Ｂ矢視断面図であり、図６は、図５の要部拡大図である。防振装置８１は、内筒８２と、それを軸平行に取り囲む外筒８３と、両者を連結するゴム状弾性体８４と、内筒８２を挟んで位置する一対のすぐり部８５とを備える。ゴム状弾性体８４の軸方向側面８４ａは、内筒８２の外周面から径方向外側に延在し、図６に示すように外筒８３の端面８３ａと軸方向位置を同じくして外筒３の内周面に達している。 An example of such a vibration isolator is shown in FIG. 5 is a cross-sectional view taken along the line B-B in FIG. 4, and FIG. 6 is an enlarged view of a main part in FIG. 5. The vibration isolator 81 includes an inner cylinder 82, an outer cylinder 83 that surrounds the inner cylinder 82, a rubber-like elastic body 84 that couples the inner cylinder 82, and a pair of straight portions 85 that are positioned with the inner cylinder 82 interposed therebetween. The axial side surface 84a of the rubber-like elastic body 84 extends radially outward from the outer peripheral surface of the inner cylinder 82, and has the same axial position as the end surface 83a of the outer cylinder 83 as shown in FIG. Has reached the inner peripheral surface.

また、この防振装置８１は、内筒８２の軸方向中央部の外周面から径方向外側に突出する環状凸部８６を備える、いわゆるバルジタイプの防振装置である。このようなバルジタイプの防振装置では、下記特許文献１にも開示されているように、ゴム状弾性体の軸方向中央部の厚みが小さくなることから、軸直角方向の剛性を大きくすることができる。そのため、サスペンションブッシュとして用いた場合には、ゴム状弾性体を軟質ゴムにより成形してこじり方向の剛性を小さくしながらも、軸直角方向の剛性を確保して、乗心地性と操縦安定性とを両立することができる。 The vibration isolator 81 is a so-called bulge type vibration isolator including an annular convex portion 86 protruding radially outward from the outer peripheral surface of the central portion of the inner cylinder 82 in the axial direction. In such a bulge type vibration isolator, as disclosed in Patent Document 1 below, the thickness of the central portion in the axial direction of the rubber-like elastic body is reduced, so that the rigidity in the direction perpendicular to the axis is increased. Can do. For this reason, when used as a suspension bush, the rubber-like elastic body is molded from soft rubber to reduce the rigidity in the twisting direction, while ensuring the rigidity in the direction perpendicular to the axis, so that riding comfort and handling stability are improved. Can be achieved.

ところで、この種の防振装置においては、装着される装置や部位等によって種々の特性が要求されることとなり、その要求特性に応じて軸直角方向におけるバネ定数やバネ比を適宜にチューニングする必要がある。かかるバネ特性のチューニングは、ゴム状弾性体の硬度やすぐり部の形状を調整することで行うのが一般的であり、その自由度については十分に確保されていることが望ましい。 By the way, in this type of vibration isolator, various characteristics are required depending on the apparatus and part to be mounted, and it is necessary to appropriately tune the spring constant and the spring ratio in the direction perpendicular to the axis according to the required characteristics. There is. Tuning of the spring characteristics is generally performed by adjusting the hardness of the rubber-like elastic body and the shape of the straight portion, and it is desirable that the degree of freedom is sufficiently secured.

また、解析の結果、上記のような防振装置８１では、振動入力時にゴム状弾性体８４の表面及び内筒８２周りの歪みが高くなり、すぐり部８５の周方向両端８５ａに亀裂が発生し易くなることが判明した。そのうえ、環状凸部８６を備えることにより、内筒８２と外筒８３とが相対的に近接した際にゴム状弾性体８４が強く押圧されるため、その軸方向側面８４ａが軸方向外側（図６右側）に大きく膨出する傾向にあり、外筒８３の内周面との界面８７より亀裂が発生し易くなることが判明した。 Further, as a result of the analysis, in the vibration isolator 81 as described above, the strain around the surface of the rubber-like elastic body 84 and the inner cylinder 82 increases when vibration is input, and cracks occur at both circumferential ends 85a of the straight portion 85. It turned out to be easier. In addition, since the rubber-like elastic body 84 is strongly pressed when the inner cylinder 82 and the outer cylinder 83 are relatively close to each other by providing the annular convex portion 86, the axial side surface 84 a is axially outer (see FIG. 6 right side) tends to bulge greatly, and it has been found that cracks are more likely to occur from the interface 87 with the inner peripheral surface of the outer cylinder 83.

下記特許文献２には、内筒を挟んで位置する一対のすぐり部を設けるとともに、ゴム状弾性体の軸方向中央部に拘束リングを埋設し、該すぐり部で拘束リングを完全に露出させた防振装置が記載されている。この防振装置によれば、軸直角方向のバネ定数を高めつつ、すぐり部の配列方向においてはバネ定数を低下させることができ、チューニングの自由度を確保する点で有用ではあるが、拘束リングが別途必要となるために部品点数の増加が避けられない。
実開平６−７６７２９号公報実開平６−２２６３９号公報 In the following Patent Document 2, a pair of straight portions positioned between the inner cylinders are provided, and a restraining ring is embedded in the central portion in the axial direction of the rubber-like elastic body so that the restraining ring is completely exposed at the straight portion. An anti-vibration device is described. According to this vibration isolator, while increasing the spring constant in the direction perpendicular to the axis, the spring constant can be reduced in the arrangement direction of the straight portions, which is useful in terms of ensuring the degree of freedom in tuning. However, an increase in the number of parts is inevitable.
Japanese Utility Model Publication No. 6-76729 Japanese Utility Model Publication No. 6-22639

本発明は上記実情に鑑みてなされたものであり、その目的は、軸直角方向におけるバネ特性のチューニングの自由度を十分に確保できる防振装置を提供することにあり、本発明の更なる目的は、ゴム状弾性体の亀裂の発生を抑制して優れた耐久性を発揮することができる防振装置を提供することにある。 The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration isolator capable of sufficiently securing the degree of freedom of tuning of spring characteristics in the direction perpendicular to the axis. An object of the present invention is to provide a vibration isolator capable of suppressing the occurrence of cracks in a rubber-like elastic body and exhibiting excellent durability.

上記目的は、下記の如き本発明により達成することができる。即ち、本発明に係る防振装置は、内筒と、前記内筒を軸平行に取り囲む外筒と、前記内筒と前記外筒とを連結するゴム状弾性体と、前記内筒と前記外筒との間にて前記内筒を挟んで位置する一対のすぐり部と、前記内筒の軸方向中央部の外周面から径方向外側に突出する環状凸部とを備え、前記環状凸部が、軸直角となる第１の方向に突出して前記すぐり部に対向する一対の第１部分と、前記第１の方向に直交して軸直角となる第２の方向に突出する一対の第２部分と、前記第１部分及び前記第２部分よりも突出高さを小さくして径方向内側に凹み、前記第１部分と前記第２部分との間に介在して両者を連ねる第３部分とを有するものである。 The above object can be achieved by the present invention as described below. That is, the vibration isolator according to the present invention includes an inner cylinder, an outer cylinder that surrounds the inner cylinder in an axially parallel manner, a rubber-like elastic body that connects the inner cylinder and the outer cylinder, the inner cylinder, and the outer cylinder. A pair of straight portions positioned between the cylinder and the inner cylinder, and an annular protrusion protruding radially outward from the outer peripheral surface of the axially central portion of the inner cylinder, the annular protrusion A pair of first portions projecting in a first direction perpendicular to the axis and facing the straight portion; and a pair of second portions projecting in a second direction orthogonal to the first direction and perpendicular to the axis And a third portion that is recessed inwardly in the radial direction with a projecting height smaller than that of the first portion and the second portion, and is interposed between the first portion and the second portion. It is what you have.

本発明に係る防振装置によれば、環状凸部が、互いに直交する軸直角方向に突出した第１部分及び第２部分と、径方向内側に凹んで両者を連ねる第３部分とを有することから、その第１部分と第２部分との突出高さを個別に設定することができ、例えば第１部分の突出高さを保持したまま第２部分の突出高さを容易に増減させることができる。その結果、すぐり部が配列された軸直角方向のバネ定数、それに直交する軸直角方向のバネ定数、及びそれらのバネ比を適宜且つ容易に調整でき、軸直角方向におけるバネ特性のチューニングの自由度を十分に確保することができる。 According to the vibration isolator of the present invention, the annular convex part has the first part and the second part protruding in the direction perpendicular to the axis orthogonal to each other, and the third part recessed inward in the radial direction and connecting the both. Thus, the protruding heights of the first part and the second part can be individually set. For example, the protruding height of the second part can be easily increased or decreased while maintaining the protruding height of the first part. it can. As a result, the spring constant in the direction perpendicular to the axis where the straight portions are arranged, the spring constant in the direction perpendicular to the axis perpendicular thereto, and the spring ratio thereof can be adjusted appropriately and easily, and the degree of freedom in tuning the spring characteristics in the direction perpendicular to the axis Can be secured sufficiently.

これに対して、環状凸部の外周面が軸方向から見て円形又は楕円形をなす場合には、軸直角方向の環状凸部の突出高さが、それに直交する軸直角方向の環状凸部の外周面の曲率に応じて制限され易く、軸直角方向のバネ定数やバネ比の設定範囲が狭められることとなるため、バネ特性のチューニングの自由度を十分に確保することが難しくなる。 On the other hand, when the outer peripheral surface of the annular convex portion is circular or elliptical when viewed from the axial direction, the projecting height of the annular convex portion in the direction perpendicular to the axis is the annular convex portion in the direction perpendicular to the axis perpendicular thereto. Since the setting range of the spring constant and the spring ratio in the direction perpendicular to the axis is narrowed, it is difficult to ensure a sufficient degree of freedom in tuning the spring characteristics.

上記において、前記すぐり部が周方向に沿って円弧状に延び、前記すぐり部の周方向両端が膨出形成されているとともに、前記第１部分又は前記第２部分の外周面よりも径方向内側に拡がって前記第３部分に対向するものが好ましい。これにより、すぐり部の周方向両端の幅寸法を大きく確保することができ、その両端への歪みの集中を好適に抑制することができる。その結果、ゴム状弾性体の亀裂の発生を効果的に防いで耐久性を向上することができる。 In the above, the curb portion extends in an arc shape along the circumferential direction, both ends of the curb portion in the circumferential direction are bulged, and radially inward from the outer peripheral surface of the first portion or the second portion. It is preferable that it extends in the direction facing the third portion. Thereby, it is possible to ensure a large width dimension at both ends in the circumferential direction of the straight portion, and it is possible to suitably suppress the concentration of distortion at the both ends. As a result, it is possible to effectively prevent cracking of the rubber-like elastic body and improve durability.

また、本発明に係る防振装置は、内筒と、前記内筒を軸平行に取り囲む外筒と、前記内筒と前記外筒とを連結するゴム状弾性体と、前記内筒と前記外筒との間にて前記内筒を挟んで位置する一対のすぐり部と、前記内筒の軸方向中央部の外周面から径方向外側に突出する環状凸部とを備え、前記ゴム状弾性体の軸方向側面が、前記内筒から前記外筒に向かって、前記ゴム状弾性体の軸方向長さを漸減させながら延在する第１の面と、前記第１の面の外周から立ち上がって、前記ゴム状弾性体の軸方向長さを大きくする第２の面と、前記第２の面の外周から前記外筒の内周面に向かって延び、前記外筒の端面より軸方向中央側に間隔を空けた位置に達し、軸方向断面にて軸方向中央側に凹んだ円弧状をなす第３の面とを有するものである。 The vibration isolator according to the present invention includes an inner cylinder, an outer cylinder that surrounds the inner cylinder in an axially parallel manner, a rubber-like elastic body that connects the inner cylinder and the outer cylinder, the inner cylinder, and the outer cylinder. A rubber-like elastic body, comprising: a pair of straight portions positioned between the cylinder and the inner cylinder; and an annular convex portion protruding radially outward from an outer peripheral surface of an axially central portion of the inner cylinder. A first surface extending from the inner cylinder toward the outer cylinder while gradually decreasing the axial length of the rubber-like elastic body, and rising from the outer periphery of the first surface A second surface that increases the axial length of the rubber-like elastic body, and extends from the outer periphery of the second surface toward the inner peripheral surface of the outer cylinder, and is axially central from the end surface of the outer cylinder. And a third surface having an arcuate shape that is recessed toward the axially central side in the axial cross section.

上記構成によれば、ゴム状弾性体の軸方向側面が上記の如き第３の面を介して外筒の内周面に達することにより、ゴム状弾性体が強く押圧されて軸方向側面が膨出変形する際においても、外筒の内周面との界面近傍に歪みを集中させることなく、亀裂の発生を抑制してゴム状弾性体の耐久性を向上することができる。これに対して、図４〜６に示した例の場合、上述のように外筒の内周面との界面より亀裂が発生し易くなる。また、軸方向断面にて第３の面が外筒の内周面に向かって単に傾斜している場合には、その界面近傍に歪みが集中して亀裂が発生し易くなるとともに、成形型からの脱型性が低下する。 According to the above configuration, when the axial side surface of the rubber-like elastic body reaches the inner peripheral surface of the outer cylinder via the third surface as described above, the rubber-like elastic body is strongly pressed and the axial side surface is expanded. Even at the time of deformation, the occurrence of cracks can be suppressed and the durability of the rubber-like elastic body can be improved without concentrating strain near the interface with the inner peripheral surface of the outer cylinder. On the other hand, in the case of the example shown in FIGS. 4 to 6, cracks are likely to occur at the interface with the inner peripheral surface of the outer cylinder as described above. Further, when the third surface is simply inclined toward the inner peripheral surface of the outer cylinder in the axial cross section, strain is concentrated near the interface and cracks are easily generated. The demoldability of is reduced.

以下、本発明の実施の形態について図面を参照しながら説明する。図１は、本発明に係る防振装置の一例を示す平面図である。図２は、図１のＡ−Ａ矢視断面図であり、図３は、図２の要部拡大図である。この防振装置１は、例えば自動車のサスペンション機構などの振動伝達系を構成する部材間に介装されるサスペンションブッシュとして用いることができる。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an example of a vibration isolator according to the present invention. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is an enlarged view of a main part of FIG. The vibration isolator 1 can be used as a suspension bush interposed between members constituting a vibration transmission system such as an automobile suspension mechanism.

防振装置１は、内筒２と、内筒２を軸平行に取り囲む外筒３と、内筒２と外筒３との間に介在して両者を弾性的に連結するゴム状弾性体４とを備える。内筒２は、その端面に鋸刃状の山形溝が形成されており、軸方向端部を少し残してゴム状弾性体４に外周面を覆われている。内筒２及び外筒３は、鋼材や高剛性樹脂材料など公知の高剛性材料にて形成することができる。一方、ゴム状弾性体４としては、自動車用防振ゴムの技術分野における公知のゴム材料を限定なく使用することができる。 The vibration isolator 1 includes an inner cylinder 2, an outer cylinder 3 that surrounds the inner cylinder 2 in an axially parallel manner, and a rubber-like elastic body 4 that is interposed between the inner cylinder 2 and the outer cylinder 3 and elastically connects the two. With. The inner cylinder 2 is formed with sawtooth-shaped chevron grooves on its end surface, and the outer peripheral surface is covered with a rubber-like elastic body 4 with a little axial end. The inner cylinder 2 and the outer cylinder 3 can be formed of a known high-rigidity material such as a steel material or a high-rigidity resin material. On the other hand, as the rubber-like elastic body 4, a known rubber material in the technical field of automobile vibration-proof rubber can be used without limitation.

また、防振装置１は、内筒２と外筒３との間にて内筒２を挟んで位置する一対のすぐり部５を備える。各すぐり部５は、それぞれ周方向に沿って円弧状に所要の長さで延在している。すぐり部５は、ゴム状弾性体４を加硫成形する際に、すぐり部５に対応した中子を成形型内に配設しておくことで容易に成形できるものであるが、加硫成形後のゴム状弾性体４にくり抜き加工を施すことで成形しても構わない。 In addition, the vibration isolator 1 includes a pair of straight portions 5 positioned between the inner cylinder 2 and the outer cylinder 3 with the inner cylinder 2 interposed therebetween. Each of the straight portions 5 extends in a circular arc shape with a required length along the circumferential direction. The curled portion 5 can be easily molded by arranging a core corresponding to the curled portion 5 in the mold when the rubber-like elastic body 4 is vulcanized. You may shape | mold by giving a hollow process to the rubber-like elastic body 4 after.

すぐり部５は、周方向に略１／４周の長さで延びてゴム状弾性体４を軸方向に貫通する貫通部５１と、貫通部５１の周方向の両側に凹設されたフィレット部５２とを有する。ストッパゴム６は、外筒３から内筒２に向かって突出しつつ貫通部５１に面するようにして設けられており、軸直角となる第１の方向ＲＤ１に所定以上の荷重が入力された際にストッパ作用を奏して、内筒２と外筒３との過大な相対変位を規制する。 The straight portion 5 has a length of approximately ¼ circumference in the circumferential direction and penetrates the rubber-like elastic body 4 in the axial direction, and a fillet portion recessed on both sides in the circumferential direction of the penetration portion 51. 52. The stopper rubber 6 is provided so as to protrude from the outer cylinder 3 toward the inner cylinder 2 so as to face the penetrating portion 51, and when a predetermined load or more is input in the first direction RD1 that is perpendicular to the axis. In this way, an excessive relative displacement between the inner cylinder 2 and the outer cylinder 3 is restricted.

更に、防振装置１は、内筒２の軸方向中央部の外周面から径方向外側に突出する環状凸部７を備える。環状凸部７は、第１の方向ＲＤ１に突出してすぐり部５に対向する一対の第１部分７１と、第１の方向ＲＤ１に直交して軸直角となる第２の方向ＲＤ２に突出する一対の第２部分７２と、第１部分７１及び第２部分７２よりも突出高さを小さくして径方向内側に凹み、第１部分７１と第２部分７２との間に介在して両者を連ねる第３部分７３とを有し、軸方向ＡＤから見て図１に示すような十文字状の外形を有する。 Further, the vibration isolator 1 includes an annular protrusion 7 that protrudes radially outward from the outer peripheral surface of the central portion in the axial direction of the inner cylinder 2. The annular convex portion 7 projects in the first direction RD1 and faces the straight portion 5, and a pair projects in the second direction RD2 perpendicular to the first direction RD1 and perpendicular to the axis. The second portion 72 and the first portion 71 and the second portion 72 have a lower projection height and are recessed radially inward, and are interposed between the first portion 71 and the second portion 72 to link them together. The third portion 73 has a cross-shaped outer shape as shown in FIG. 1 when viewed from the axial direction AD.

本実施形態では、第１部分７１及び第２部分７２の外周面を図１、２に示すように湾曲面により構成している。また、第３部分７３の外周面が軸方向ＡＤから見て円弧状に形成されており、第１部分７１と第２部分７２とをなだらかに連ねて歪みの集中を極力抑制している。なお、本実施形態では環状凸部７が内筒２と一体的に鍛造成形された例を示すが、本発明はこれに限られず、例えば樹脂製の別体品とした環状凸部を内筒２の軸方向中央部に外嵌固着したものでもよい。 In the present embodiment, the outer peripheral surfaces of the first portion 71 and the second portion 72 are constituted by curved surfaces as shown in FIGS. Further, the outer peripheral surface of the third portion 73 is formed in an arc shape when viewed from the axial direction AD, and the first portion 71 and the second portion 72 are connected smoothly to suppress the concentration of distortion as much as possible. In the present embodiment, an example in which the annular convex portion 7 is forged integrally with the inner cylinder 2 is shown, but the present invention is not limited to this, and the annular convex portion made of, for example, a resin is used as the inner cylinder. 2 may be externally fitted and fixed to the central portion in the axial direction.

かかる環状凸部７においては、第１部分７１と第２部分７２との突出高さを個別に設定することができる。例えば、第１部分７１については図１に示した突出高さを保持したまま、第２部分７２の突出高さだけを低くして、第２の方向ＲＤ２の低ばね化を容易に図ることができる。そのため、第１の方向ＲＤ１や第２の方向ＲＤ２のバネ定数、及びそれらのバネ比を適宜且つ容易に調整でき、軸直角方向におけるバネ特性のチューニングの自由度を十分に確保することができる。 In the annular convex portion 7, the protruding heights of the first portion 71 and the second portion 72 can be set individually. For example, it is possible to easily reduce the spring in the second direction RD2 by reducing only the protrusion height of the second portion 72 while maintaining the protrusion height shown in FIG. it can. Therefore, the spring constants in the first direction RD1 and the second direction RD2 and their spring ratios can be adjusted appropriately and easily, and a sufficient degree of freedom in tuning the spring characteristics in the direction perpendicular to the axis can be secured.

本実施形態では、第１部分７１と第２部分７２との突出高さが同等であるが、本発明では、上述した軸直角方向におけるバネ特性のチューニングを行うにあたり、これらの突出高さを互いに異ならせても構わない。また、本実施形態では、第１部分７１と第２部分７２との周方向長さや外周面の曲率が同等である例を示すが、これらを異ならせても構わない。 In the present embodiment, the protrusion heights of the first portion 71 and the second portion 72 are the same. However, in the present invention, when performing the tuning of the spring characteristics in the direction perpendicular to the axis, the protrusion heights are set to each other. You can make them different. Further, in the present embodiment, an example in which the circumferential length and the curvature of the outer circumferential surface of the first portion 71 and the second portion 72 are equivalent is shown, but these may be different.

一対のすぐり部５は、その周方向両端５ａが膨出形成されており、しかも第１部分７１及び第２部分７２の外周面よりも径方向内側に拡がって、第３部分７３に対向している。これにより、すぐり部５の周方向両端５ａの幅寸法を大きく確保して、その両端５ａへの歪みの集中を抑制することができ、その結果、ゴム状弾性体４の亀裂の発生を効果的に防いで耐久性を向上できる。かかる効果をより好適に奏するべく、本実施形態では、すぐり部５の周方向両端５ａの内壁面が、第３部分７３の外周面に対応するように円弧状に形成されている。 The pair of straight portions 5 are formed so that their circumferential ends 5 a bulge, and further expand radially inward from the outer peripheral surfaces of the first portion 71 and the second portion 72 and face the third portion 73. Yes. Thereby, the width dimension of the circumferential direction both ends 5a of the straight part 5 can be ensured large, and the concentration of the distortion to the both ends 5a can be suppressed. As a result, generation of cracks in the rubber-like elastic body 4 is effective. It can prevent and improve durability. In order to achieve this effect more suitably, in this embodiment, the inner wall surfaces of the circumferential ends 5 a of the straight portion 5 are formed in an arc shape so as to correspond to the outer peripheral surface of the third portion 73.

これに対して、環状凸部７が軸方向から見て円形をなす場合には、上述したバネ特性のチューニングの自由度を十分に確保するのが難しくなるだけでなく、すぐり部５の周方向両端５ａの幅寸法を図１のように大きく確保することができない。つまり、本実施形態は、環状凸部７の第３部分７３の形状を利用して周方向両端５ａの幅寸法を大きく確保するものであり、図４の例に対して環状凸部７の最大径が同等である場合には、バネ特性を変化させずに耐久性を向上できることになる。 On the other hand, when the annular protrusion 7 is circular as viewed from the axial direction, not only is it difficult to ensure a sufficient degree of freedom in tuning the spring characteristics described above, but also the circumferential direction of the straight portion 5. The width dimension of the both ends 5a cannot be ensured as shown in FIG. That is, this embodiment ensures the width dimension of the circumferential direction both ends 5a large using the shape of the 3rd part 73 of the cyclic | annular convex part 7, and is the largest of the cyclic | annular convex part 7 with respect to the example of FIG. When the diameters are the same, the durability can be improved without changing the spring characteristics.

ゴム状弾性体４は、内筒２の外周面と外筒３の内周面とに加硫接着されており、内筒２を外筒３に対して弾性的に支持している。比較的振幅が小さい振動が入力された際には、このゴム状弾性体４の撓みにより防振効果が発揮される。突起４２は、ゴム状弾性体４の軸方向側面４１に第２の方向ＲＤ２に沿って突設され、防振装置１の識別や周方向の位置決めに利用される。 The rubber-like elastic body 4 is vulcanized and bonded to the outer peripheral surface of the inner cylinder 2 and the inner peripheral surface of the outer cylinder 3, and elastically supports the inner cylinder 2 with respect to the outer cylinder 3. When vibration having a relatively small amplitude is input, the vibration-proof effect is exhibited by the bending of the rubber-like elastic body 4. The protrusion 42 protrudes along the second direction RD2 on the axial side surface 41 of the rubber-like elastic body 4 and is used for identification of the vibration isolator 1 and positioning in the circumferential direction.

ゴム状弾性体４の軸方向側面４１は、図３に拡大して示すように、内筒２から外筒３に向かって、ゴム状弾性体４の軸方向長さを漸減させながら延在する第１の面４１ａと、第１の面４１ａの外周から立ち上がって、ゴム状弾性体４の軸方向長さを大きくする第２の面４１ｂと、第２の面４１ｂの外周から外筒３の内周面に向かって延びる第３の面４１ｃとが連設されてなる。上述した突起４２は第１の面４１ａに突設されている。 The axial side surface 41 of the rubber-like elastic body 4 extends from the inner cylinder 2 toward the outer cylinder 3 while gradually decreasing the axial length of the rubber-like elastic body 4 as shown in FIG. The first surface 41a, the second surface 41b that rises from the outer periphery of the first surface 41a and increases the axial length of the rubber-like elastic body 4, and the outer tube 3 from the outer periphery of the second surface 41b. A third surface 41c extending toward the inner peripheral surface is connected. The protrusion 42 described above is provided on the first surface 41a.

第３の面４１ｃは、外筒３の端面３１より軸方向中央側に間隔を空けた位置に達し、軸方向断面にて軸方向中央側に凹んだ円弧状をなしている。これにより、軸方向側面４１の自由長が増大するだけでなく、第２の面４１ｂと外筒３の内周面との間に第３の面４１ｃが介在することで、ゴム状弾性体４が強く押圧された際の軸方向側面４１の膨出変形が、外筒３の内周面との界面近傍に直に及ぶことを抑制でき、ゴム状弾性体４の耐久性を向上することができる。 The third surface 41c reaches a position spaced from the end surface 31 of the outer cylinder 3 toward the axially central side, and has an arc shape recessed toward the axially central side in the axial section. Thereby, not only the free length of the axial side surface 41 is increased, but also the third surface 41 c is interposed between the second surface 41 b and the inner peripheral surface of the outer cylinder 3, so that the rubber-like elastic body 4. It is possible to prevent the bulging deformation of the axial side surface 41 when the pressure is strongly pressed from reaching the vicinity of the interface with the inner peripheral surface of the outer cylinder 3 and to improve the durability of the rubber-like elastic body 4. it can.

これに対して、第３の面４１ｃを有しない場合や、第３の面４１ｃが外筒３の内周面に向かって単に傾斜している場合には、軸方向側面４１の膨出変形が外筒３の内周面との界面近傍に及び易くなり、そのために界面近傍に歪みが集中して亀裂が発生し易くなる。本実施形態では、上述した耐久性の向上効果を適切に奏する観点から、外筒３の端面３１から第３の面４１ｃまでの間隔Ｇが０．５ｍｍ以上であることが好ましく、１ｍｍ以上であることがより好ましい。 On the other hand, when the third surface 41c is not provided, or when the third surface 41c is simply inclined toward the inner peripheral surface of the outer cylinder 3, the bulging deformation of the axial side surface 41 is caused. It becomes easy to reach the vicinity of the interface with the inner peripheral surface of the outer cylinder 3, and for this reason, strain is concentrated near the interface and cracks are likely to occur. In the present embodiment, the distance G from the end surface 31 of the outer cylinder 3 to the third surface 41c is preferably 0.5 mm or more from the viewpoint of appropriately achieving the durability improvement effect described above, and is preferably 1 mm or more. It is more preferable.

本発明は上述した実施形態に何ら限定されるものではなく、本発明の趣旨を逸脱しない範囲内で種々の改良変更が可能であり、例えばゴム状弾性体の特性などは使用する用途に応じて適宜に変更することができる。 The present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, the characteristics of the rubber-like elastic body depend on the application to be used. It can be changed as appropriate.

本発明に係る防振装置の一例を示す平面図The top view which shows an example of the vibration isolator which concerns on this invention 図１のＡ−Ａ矢視断面図AA arrow sectional view of FIG. 図２の要部拡大図2 is an enlarged view of the main part of FIG. 防振装置の一例を示す平面図Plan view showing an example of a vibration isolator 図４のＢ−Ｂ矢視断面図BB arrow sectional view of FIG. 図５の要部拡大図Enlarged view of the main part of FIG.

符号の説明Explanation of symbols

１防振装置
２内筒
３外筒
４ゴム状弾性体
５すぐり部
５ａすぐり部の周方向両端
７環状凸部
３１端面
４１軸方向側面
４１ａ第１の面
４１ｂ第２の面
４１ｃ第３の面
５１貫通部
５２フィレット部
７１第１部分
７２第２部分
７３第３部分
ＡＤ軸方向
ＲＤ１第１の方向
ＲＤ２第２の方向 DESCRIPTION OF SYMBOLS 1 Anti-vibration device 2 Inner cylinder 3 Outer cylinder 4 Rubber-like elastic body 5 Curled part 5a Both circumferential ends 7 of the curled part Annular convex part 31 End surface 41 Axial side surface 41a First surface 41b Second surface 41c Third surface 51 Penetration part 52 Fillet part 71 1st part 72 2nd part 73 3rd part AD Axial direction RD1 1st direction RD2 2nd direction

Claims

内筒と、前記内筒を軸平行に取り囲む外筒と、前記内筒と前記外筒とを連結するゴム状弾性体と、前記内筒と前記外筒との間にて前記内筒を挟んで位置する一対のすぐり部と、前記内筒の軸方向中央部の外周面から径方向外側に突出する環状凸部とを備え、
前記環状凸部が、
軸直角となる第１の方向に突出して前記すぐり部に対向する一対の第１部分と、
前記第１の方向に直交して軸直角となる第２の方向に突出する一対の第２部分と、
前記第１部分及び前記第２部分よりも突出高さを小さくして径方向内側に凹み、前記第１部分と前記第２部分との間に介在して両者を連ねる第３部分とを有する防振装置。 An inner cylinder, an outer cylinder that surrounds the inner cylinder in an axially parallel manner, a rubber-like elastic body that connects the inner cylinder and the outer cylinder, and the inner cylinder is sandwiched between the inner cylinder and the outer cylinder And a pair of straight portions, and an annular convex portion projecting radially outward from the outer peripheral surface of the axial central portion of the inner cylinder,
The annular convex portion is
A pair of first portions projecting in a first direction perpendicular to the axis and facing the straight portion;
A pair of second portions projecting in a second direction perpendicular to the first direction and perpendicular to the axis;
A protective portion having a third portion that is recessed inwardly in the radial direction with a projecting height smaller than that of the first portion and the second portion, and is interposed between the first portion and the second portion. Shaker.

前記すぐり部が周方向に沿って円弧状に延び、
前記すぐり部の周方向両端が膨出形成されているとともに、前記第１部分又は前記第２部分の外周面よりも径方向内側に拡がって前記第３部分に対向する請求項１記載の防振装置。 The straight portion extends in an arc shape along the circumferential direction,
The anti-vibration device according to claim 1, wherein both ends of the curb portion in the circumferential direction are formed to bulge and extend radially inward from the outer peripheral surface of the first portion or the second portion to face the third portion. apparatus.

内筒と、前記内筒を軸平行に取り囲む外筒と、前記内筒と前記外筒とを連結するゴム状弾性体と、前記内筒と前記外筒との間にて前記内筒を挟んで位置する一対のすぐり部と、前記内筒の軸方向中央部の外周面から径方向外側に突出する環状凸部とを備え、
前記ゴム状弾性体の軸方向側面が、
前記内筒から前記外筒に向かって、前記ゴム状弾性体の軸方向長さを漸減させながら延在する第１の面と、
前記第１の面の外周から立ち上がって、前記ゴム状弾性体の軸方向長さを大きくする第２の面と、
前記第２の面の外周から前記外筒の内周面に向かって延び、前記外筒の端面より軸方向中央側に間隔を空けた位置に達し、軸方向断面にて軸方向中央側に凹んだ円弧状をなす第３の面とを有する防振装置。 An inner cylinder, an outer cylinder that surrounds the inner cylinder in an axially parallel manner, a rubber-like elastic body that connects the inner cylinder and the outer cylinder, and the inner cylinder is sandwiched between the inner cylinder and the outer cylinder And a pair of straight portions, and an annular convex portion projecting radially outward from the outer peripheral surface of the axial central portion of the inner cylinder,
An axial side surface of the rubber-like elastic body is
A first surface extending from the inner cylinder toward the outer cylinder while gradually decreasing the axial length of the rubber-like elastic body;
A second surface that rises from the outer periphery of the first surface and increases the axial length of the rubber-like elastic body;
Extends from the outer periphery of the second surface toward the inner peripheral surface of the outer cylinder, reaches a position spaced from the end surface of the outer cylinder toward the axially central side, and is recessed toward the axially central side in the axial section. And a third surface having an arcuate shape.