JP2009185883A - Vibration isolating connecting rod - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolating connecting rod having a new structure which can control deterioration in a transfer state of vibration caused by resonance of a rigid body at the time of input of vibration, and which can effectively improve vibration isolating characteristics. <P>SOLUTION: In one vibration system constituted by mass containing a rod body 12 and by a spring comprised of first and second vibration isolating members 24, 38, the center of gravity of mass is unbalanced with respect to the elastic main axis of the spring extended in the longitudinal direction of the rod body 12. By the main input of vibration into the rod body 12 in the direction perpendicular to the axis, vibration in the roll direction can be generated which is about the elastic main axis with respect to the one vibration system. The mass and the spring of one vibration system are set so that the resonance frequency of the displacement vibration in the roll direction of the rod body 12 overlaps the resonance frequency of the vibration in the main vibration input direction of the rod body 12 which is generated in one vibration system by the main vibration input. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an anti-vibration connecting rod that is suitably employed, for example, as a torque rod or suspension arm of an automobile and connects members to be connected to each other.

  Conventionally, an anti-vibration connecting rod that is interposed between two members and mutually anti-vibrates and connects these members to be connected has been generally used. The connecting rod has, for example, a structure in which a vibration isolating connecting portion is provided at both ends of the rod body which is formed in a longitudinal shape, and the anti-vibration connecting portion is attached to each one member to be connected to each other. It is supposed to be. Such an anti-vibration connecting rod is used, for example, as a torque rod or suspension arm of an automobile, and is specifically shown in Patent Document 1 (Japanese Patent Laid-Open No. 2004-316798).

  By the way, if a connection object member is mutually connected by a vibration isolating connecting rod, the vibration transmission from one side of the connection object member to the other side may become a problem. In particular, since the rod main body is elastically attached to the connection target member via the vibration isolating member constituting the vibration isolating connecting portion, the mass including the rod main body and the mass using the vibration isolating member as a spring is used. -A spring system is constructed. Therefore, when vibration in the resonance frequency range of the mass-spring system is input, the input vibration may be amplified and transmitted to the connection target member due to the rigid resonance of the vibration-isolating connecting rod, and the vibration transmission state There was a case where the deterioration of was a problem.

  Therefore, for example, as shown in Patent Document 2 (Japanese Patent Laid-Open No. 2001-200892), the rod body is made of an aluminum alloy to reduce the weight of the mass, thereby increasing the resonance frequency of the anti-vibration connecting rod. The structure which prevents the deterioration of a vibration state is also proposed by making it shift to the side and making it a frequency higher than the frequency range of the input vibration which becomes a problem.

  However, in the rod body made of aluminum alloy, it is difficult to ensure sufficient rigidity as compared to the rod body made of steel, and in order to maintain sufficiently high rigidity, the cross-sectional area of the rod body is extended and the connecting rod There was a possibility that it would be necessary to enlarge the whole. In addition, changing the material of the rod body did not avoid the problem of vibration due to resonance. Furthermore, since aluminum alloys are more expensive than iron, there is also a demerit that the cost is directly increased. Because of the above problems, there has been a demand for an anti-vibration connecting rod that can reduce or avoid the deterioration of the vibration transmission state due to the resonance phenomenon while maintaining a sufficient degree of freedom of the material.

  Therefore, as shown in FIG. 3 of Patent Document 3 (Japanese Patent Laid-Open No. 8-233030), a method of improving the vibration state by attaching a dynamic damper to the rod body has been proposed. According to this, it is possible to obtain a vibration reduction effect without limiting the material of the rod body to a lightweight material. However, in a structure in which a dynamic damper is retrofitted to the rod body, a special work process is required to attach the dynamic damper, which may cause a reduction in productivity. Further, since an extra space is required for disposing the dynamic damper, it may be difficult to employ when the disposing space of the connecting rod is limited. Furthermore, since the mass of the entire connecting rod increases due to the addition of the mass component of the dynamic damper, the increase in the weight may be a serious problem particularly when used in an automobile having a high demand for weight reduction. There is.

JP 2004-316798 A Japanese Patent Laid-Open No. 2001-200892 Japanese Patent Laid-Open No. 8-233030

  Here, the present invention has been made in the background as described above, and the problem to be solved is that, when vibration is input in the resonance frequency range, the transmission state of vibration deteriorates due to rigid body resonance. An object of the present invention is to provide an anti-vibration connecting rod having a novel structure capable of effectively improving the anti-vibration characteristics while suppressing the above-mentioned.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

  That is, the present invention is provided with a first elastic coupling portion in which the first vibration isolating member is assembled at both longitudinal ends of the rod body and a second elastic coupling portion in which the second vibration isolating member is assembled. The first elastic coupling portion is attached to one of the vibration isolation connection target members via the first vibration isolation member, and the second elastic connection portion is interposed via the second vibration isolation member. By attaching the anti-vibration connection target member to the other of the anti-vibration connection target members, the anti-vibration connection rod elastically connects the two anti-vibration connection target members. In one vibration system constituted by a spring by a member, the center of gravity of the mass is biased with respect to the elastic main shaft of the spring extending in the longitudinal direction of the rod body, and the main vibration input in the direction perpendicular to the axis of the rod body The shake by Vibration in the roll direction around the elastic main axis is generated with respect to the system, and vibration in the main vibration input direction of the rod main body generated in the one vibration system by the main vibration input is generated. The mass and the spring in the one vibration system are set so that the resonance frequency of the displacement vibration of the rod body in the roll direction overlaps the resonance frequency.

  In the vibration proof connecting rod having the structure according to the present invention, the center of gravity of the mass is biased with respect to the elastic main shaft of the spring extending in the longitudinal direction of the rod body, so that the inertia in the roll direction due to the main vibration input is achieved. The moment can be obtained efficiently. Therefore, when vibration in the resonance frequency range of one vibration system is input in the main vibration input direction, the rod body is displaced in the resonance state in the main vibration input direction and also vibrates in the resonance state in the roll direction. It can be displaced. As a result, vibration in the main vibration input direction is suppressed based on energy loss due to vibration displacement in the roll direction, etc., effectively reducing the deterioration of vibration isolation performance due to rigid resonance of the rod body in the main vibration input direction. Can be prevented.

  The means for displacing the center of gravity of the mass with respect to the elastic main shaft of the spring extending in the longitudinal direction of the rod body is not particularly limited. For example, the center of gravity of the rod main body is biased with respect to the elastic main shaft. In addition, the center of gravity of the first and second elastic connecting portions can be realized by adopting an asymmetric structure with the elastic main shaft in between at least one of the first and second elastic connecting portions. It can also be realized by bias.

  Further, the elastic main shaft of the spring extending in the longitudinal direction of the rod body is the elastic main shaft of the spring under vibration input in the mounted state of the vibration-proof connecting rod. For example, the spring is changed by vibration input. The elastic main axis of the spring after change under vibration input.

なお、上式において、Ｒはマス重心の変位ベクトルにおける主たる振動入力方向成分を、Ｒ^T はＲの転置ベクトルを、Ｍはマスの質量マトリックスを、Ｑはマス重心の変位ベクトルにおける回転方向成分を、Ｑ^T はＱの転置ベクトルを、Ｊはマスの慣性モーメントマトリックスをそれぞれ示す。 Further, in the anti-vibration connecting rod according to the present invention, the roll direction of the rod body with respect to the resonance frequency of the vibration in the main vibration input direction of the rod body generated in the one vibration system by the main vibration input. It is desirable that the resonance frequency of the displacement vibration is set so that the value of the coupling ratio: W represented by the following equation is 10% to 90%.

In the above equation, R is the main vibration input direction component in the displacement vector of the mass center of gravity, R ^T is the transposed vector of R, M is the mass matrix of the mass, and Q is the rotational direction component in the displacement vector of the mass center of gravity. , Q ^T are transposed vectors of Q, and J is a mass moment of inertia matrix.

  By setting the resonance frequency of the vibration in the main vibration input direction of the rod body and the resonance frequency of the displacement vibration in the roll direction of the rod body so that such a coupling ratio value can be realized, the rod at the time of vibration input of the resonance frequency A low dynamic spring effect can be effectively obtained by combining the displacement vibration in the main vibration input direction of the main body and the displacement vibration in the roll direction of the rod main body.

  Further, in the vibration-isolating connecting rod according to the present invention, the first elastic connecting portion and the second elastic connecting portion are both cylinders in which the inner shaft member and the outer cylindrical member are connected by the main rubber elastic body. It may be a shape vibration isolator.

  The outer cylinder member may be an arm eye formed integrally with the rod body, or may be constituted by a separate sleeve and fixed to the rod body by means such as press fitting. Further, the central axis of the cylindrical vibration isolator constituting the first elastic coupling part and the central axis of the cylindrical vibration isolator constituting the second elastic coupling part may be parallel to each other, For example, you may extend in different directions, such as the direction which makes a right angle mutually.

  In the vibration-isolating connecting rod according to the present invention, the center of gravity of the rod main body is a plane including the elastic main axes of the first vibration-isolating member and the second vibration-isolating member extending in the main vibration input direction. On the other hand, it may be set at a position deviated.

  As described above, the center of gravity of the rod body is set at a position deviated from the plane including the elastic main axes of the first vibration isolation member and the second vibration isolation member extending in the main vibration input direction. Main vibration without adopting a special structure such as disposing a weight (mass member) to shift the surface from the plane or making the first and second elastic coupling parts asymmetric with respect to the plane. Vibration displacement in the roll direction of the rod body can be realized by input.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows a torque rod 10 for an automobile as a first embodiment of a vibration-isolating connecting rod according to the present invention. The torque rod 10 has a structure in which a first rubber bush 14 as a first elastic connecting portion and a second rubber bush 16 as a second elastic connecting portion are provided at both ends of a rod body 12 having a longitudinal shape. have. In the following description, the vertical direction means a direction orthogonal to the paper surface in FIG. 1, which is the main vibration input direction, unless otherwise specified.

  More specifically, the rod body 12 is made of iron, aluminum alloy, hard synthetic resin, or the like, and has a substantially columnar shape or frustum shape that extends in the left-right direction in FIG. . Moreover, the 1st outer cylinder part 18 and the 2nd outer cylinder part 20 as an outer cylinder member are integrally formed in the longitudinal direction both ends of the rod main body 12. As shown in FIG. In the present embodiment, the rod body 12 is formed by means such as casting.

  The first outer cylinder portion 18 has a large-diameter, generally cylindrical shape, and is formed such that the central axis extends in the vertical direction at one end portion in the longitudinal direction of the rod body 12 when the vehicle is mounted. On the other hand, the second outer cylinder part 20 has a cylindrical shape with a smaller diameter than the first outer cylinder part 18, and the central axis of the rod body 12 is the center axis at the other end in the longitudinal direction of the rod body 12. It is formed to extend in the width direction (up and down in FIG. 1). In short, in this embodiment, the 1st outer cylinder part 18 and the 2nd outer cylinder part 20 are made into the cylinder shape extended in the direction orthogonal to each other.

  Further, a first inner shaft fitting 22 as an inner shaft member is inserted through the first outer cylinder portion 18. The first inner shaft fitting 22 is a high-rigidity metal material formed of iron, aluminum alloy, or the like, and has a cylindrical shape with a smaller diameter than the first outer cylinder portion 18. Note that a first mounting bolt (not shown) is inserted through the first inner shaft bracket 22, and the first inner shaft bracket 22 is connected to one vibration-proof connection by the first mounting bolt. It is attached to a power unit (not shown) that is a target member.

  Further, the first inner shaft fitting 22 is disposed on the central axis of the first outer cylinder portion 18 so as to be separated from the first outer cylinder portion 18 by a predetermined distance over the entire circumference. Interpolated. A first main rubber elastic body 24 as a first vibration isolating member is interposed between the first inner shaft member 22 and the radially opposed surfaces of the first outer cylinder portion 18.

  The first main rubber elastic body 24 has a thick, generally cylindrical shape as a whole, and its outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the first outer cylinder portion 18, and the inner peripheral The surface is vulcanized and bonded to the outer peripheral surface of the first inner shaft fitting 22. Thereby, the 1st inner shaft metal fitting 22 and the 1st outer cylinder part 18 are mutually elastically connected by the 1st main body rubber elastic body 24, and the cylindrical vibration proof which comprises the 1st elastic connection part A first rubber bush 14 which is a device is formed at one end of the rod body 12 in the longitudinal direction.

  Further, the first main rubber elastic body 24 is formed with an inner slit 26 and an outer slit 28 on both sides of the first inner shaft member 22 in the longitudinal direction of the rod main body 12. As shown in FIG. 1, the first main rubber elastic body 24 in the present embodiment has a pair of connecting arm portions 30, 30 and inner and outer portions in a substantially circumferential direction. The rubber stoppers 32 and 34 are divided.

  More specifically, the pair of connecting arm portions 30 is positioned between the inner slit 26 and the outer slit 28. The connecting arm portion 30 is provided so as to extend in the radial direction on both sides in one radial direction with the first inner shaft fitting 22 interposed therebetween, and an end surface on the inner peripheral side of the connecting arm portion 30 is the first inner shaft. The outer peripheral surface of the shaft bracket 22 is vulcanized and bonded, and the outer peripheral end surface is vulcanized and bonded to the inner peripheral surface of the first outer cylinder portion 18, whereby the first inner shaft bracket 22 and the first The outer cylinder portions 18 are connected to each other. In the present embodiment, the pair of connecting arm portions 30 and 30 have the same shape and are formed of the same rubber material, and have the same spring constant.

  Further, a part of the first rubber elastic body 24 is used on the opposite side to the first inner shaft fitting 22 across the inner slit 26, in other words, on the inner side in the longitudinal direction of the rod body 12 across the inner slit 26. Thus, an inner rubber stopper 32 is formed. The inner rubber stopper 32 is vulcanized and bonded to the inner peripheral surface of the first outer cylinder portion 18 over a predetermined region in the circumferential direction, and the first inner shaft fitting 22 is interposed via the inner slit 26. And a predetermined distance from each other.

  Further, on the side opposite to the first inner shaft fitting 22 with the outer slit 28 interposed therebetween, in other words, on the outer side in the longitudinal direction of the rod body 12 with the outer slit 28 interposed therebetween, another part of the first main rubber elastic body 24 is provided. The outer rubber stopper 34 is formed using The outer rubber stopper 34 is vulcanized and bonded to the inner peripheral surface of the first outer cylinder portion 18 over a predetermined region in the circumferential direction, and is connected to the first inner shaft metal fitting 22 via the outer slit 28. Opposite positions are separated by a predetermined distance.

  When the first inner shaft fitting 22 and the first outer cylinder portion 18 are relatively displaced in the longitudinal direction of the rod main body 12, the first inner shaft fitting 22 and the first outer cylinder portion 18 become the inner rubber stopper. 32 or the outer rubber stopper 34 so as to be abutted against each other. Thereby, the relative displacement of the 1st inner shaft metal fitting 22 and the 1st outer cylinder part 18 in the longitudinal direction and the prying direction of the rod main body 12 is restrict | limited by buffer.

  Further, a second inner shaft fitting 36 is inserted through the second outer cylinder portion 20. The second inner shaft fitting 36 is formed of the same metal material as the first inner shaft fitting 22 and has a cylindrical shape with a smaller diameter than the second outer cylinder portion 20. Note that a second mounting bolt (not shown) is inserted into the second inner shaft bracket 36, and the second inner shaft bracket 36 is connected to the other vibration-proof connection by the second mounting bolt. It is designed to be attached to a vehicle body (not shown) that is a target member.

  Further, the second inner shaft fitting 36 is inserted into the second outer cylinder portion 20 on the same central axis, and is inserted at a predetermined distance in the radial direction. A second main rubber elastic body 38 as a second vibration isolating member is interposed between the radially inner surfaces of the second inner shaft fitting 36 and the second outer cylinder portion 20.

  The second main rubber elastic body 38 has a thick, substantially cylindrical shape, and its outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the second outer cylinder portion 20, and the inner peripheral surface is Vulcanized and bonded to the outer peripheral surface of the second inner shaft fitting 36. As a result, the second inner shaft bracket 36 and the second outer cylinder portion 20 are elastically connected to each other by the second main rubber elastic body 38, and the cylindrical vibration-proofing that constitutes the second elastic connection portion. A second rubber bush 16 that is a device is formed at the other end in the longitudinal direction of the rod body 12.

  Further, in the torque rod 10 having the structure according to the present embodiment, the mass metal fitting 40 is assembled to the outer peripheral surface of the first outer cylinder portion 18 constituting the first rubber bush 14. The mass metal fitting 40 is a member having a substantially block shape, and is formed of a metal material having a high specific gravity such as iron in the present embodiment. The mass metal fitting 40 is overlapped and fixed to the outer peripheral surface of the first outer cylinder portion 18 at a part of the circumference of the first outer cylinder portion 18.

  Here, the mass bracket 40 is formed in the width direction of the rod body 12 with respect to the elastic main axis of the spring component formed by the first main rubber elastic body 24 and the second main rubber elastic body 38 in the longitudinal direction of the rod main body 12. It is mounted in a position that is off. In other words, an elastic main shaft extending in the axial direction of the first main rubber elastic body 24 constituting the first rubber bush 14 and the second rubber bush 16 are formed on the circumference of the first outer cylinder portion 18. The second main rubber elastic body 38 is mounted at a position deviating from α: a plane including any elastic main shaft extending in the same direction. The elastic main axis of the spring component in the longitudinal direction of the rod body 12 refers to an elastic main axis in a use state in which vibration is input when the torque rod 10 is mounted on the vehicle.

  That is, when the torque rod 10 is mounted on the vehicle, the first main rubber elastic body 24 and the second main rubber whose center of gravity of the mass fitting 40 extends in the direction orthogonal to the paper surface in FIG. A plane that includes each elastic central axis of the elastic body 38 (in short, a plane indicated by a one-dot chain line in FIG. 1): deviates to one side in the circumferential direction of the first outer cylinder portion 18 with respect to α. It is positioned. In particular, in the present embodiment, the mass fitting 40 is mounted on the circumference of the first outer cylinder portion 18 at a position where the distance from the plane: α is maximum, and the center of gravity of the mass fitting 40 and the plane: α A large distance is secured. As a result, the center of gravity of the mass component described later is positioned far from the plane: α, and vibration displacement in the roll direction due to the main vibration input is effectively generated.

  By mounting the mass bracket 40 in this manner, the center of gravity of the mass component constituted by the rod body 12, the first and second outer cylinder portions 18, 20, the inner and outer stopper rubbers 32, 34, and the mass bracket 40 is flat: α On the other hand, by being separated from one surface side by a predetermined distance, it can be biased and positioned. In the present embodiment, the rod main body 12, the first and second outer cylinder portions 18 and 20, and the inner and outer stopper rubbers 32 and 34 are all symmetrical with respect to the plane: α. When the metal fitting 40 is not attached, the center of gravity of the mass component is positioned on the plane: α, and the mass metal fitting 40 is attached to one side across the plane: α, so that the center of mass of the mass component is flat: It can be positioned away from α.

  In the torque rod 10 having such a structure, the first inner shaft fitting 22 is attached to the power unit and the second inner shaft fitting 36 is attached to the vehicle body, so that both end portions of the rod body 12 are the first. The first and second rubber bushes 14 and 16 are elastically attached to the power unit and the vehicle body. As a result, the power unit and the vehicle body are connected to each other by the torque rod 10 in a vibration-proof manner.

  Further, when the torque rod 10 is mounted on an automobile, the mass component including the rod main body 12 is elastically supported via the spring component constituted by the first and second main rubber elastic bodies 24 and 38. Thereby, one vibration system as a mass-spring system is constituted by the mass component and the spring component. When a vibration load is input in the main vibration input direction in the state where the torque rod 10 is mounted on the vehicle, the rod body 12 is bounced as shown in FIG. 2 or shown in FIG. Such a pitch vibration is generated and reciprocated. In FIGS. 2 and 3, the stationary torque rod 10 is shown by a solid line, and the vibrating torque rod 10 is shown by a broken line. Further, in FIGS. 2 and 3 and FIG. 4 described later, the vibration direction is indicated by an arrow.

  Further, as described above, the mass rod 40 is attached to the torque rod 10 at a predetermined portion on the circumference of the first outer cylinder portion 18 so that the center of gravity of the mass component in one vibration system is the longitudinal length of the rod body 12. The spring component extending in the direction is positioned off the elastic main axis. Thereby, based on the vibration input in the main vibration input direction, as shown in FIG. 4, the mass component including the rod body 12 is rotated in the rotation direction (roll direction) around the elastic main axis. Vibration displacement is generated.

  Therefore, in the torque rod 10 according to the present embodiment, by appropriately adjusting the mass of the mass component and the spring constant of the spring component, the vibration frequency that causes resonance in the bounce direction or the pitch direction and resonance in the roll direction occur. The vibration frequencies are set so as to overlap each other. Note that the resonance frequency of bounce vibration or pitch vibration overlaps with the resonance frequency of roll vibration means that the frequency range that causes an increase in the dynamic spring constant based on the resonance phenomenon overlaps entirely or partially. To tell.

  Further, the vibration frequency that causes resonance in the roll direction in the torque rod 10 is preferably set to 50% to 150% of the vibration frequency that causes resonance in the main vibration input direction (bounce direction or pitch direction). Preferably, it is set to 70% to 130%.

In this embodiment, the resonance frequency of the displacement vibration in the roll direction of the rod body 12 with respect to the resonance frequency of the vibration in the main vibration input direction is 10% to 90%, more preferably 20 in terms of the coupling ratio: W. % To 80%. The coupling rate referred to here is the percentage of the kinetic energy of vibration in the roll direction of the rod body 12 relative to the entire kinetic energy of vibration of the rod body 12, in other words, the kinetic energy of vibration in the main vibration input direction and the rod The kinetic energy ratio of vibration in the roll direction of the main body 12, which is the translation direction (bounce direction) component of the displacement vector of the mass center of gravity: R, the transposed vector of R: ^RT , the mass matrix: M, and the mass center of mass The rotation direction (roll direction) component of the displacement vector of Q: Q, the transposition vector of Q: Q ^T, and the moment of inertia matrix are expressed by the following equations.

  As described above, when vibration in the resonance frequency range of vibration in the bounce direction or pitch direction is input, resonance in the roll direction is generated together with resonance in the bounce direction or pitch direction. And the vibration in the bounce direction of the rod main body 12 is reduced based on the energy loss etc. accompanying the vibration displacement in the roll direction of the rod main body 12 by resonance.

  Next, FIG. 5 shows a torque rod 42 as a second embodiment of the vibration-isolating connecting rod according to the present invention. In the following description, members and portions that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted.

  That is, in the torque rod 42, the outer rubber stopper 46 is utilized by utilizing a part of the first main rubber elastic body 44 interposed between the first outer cylinder portion 18 and the first inner shaft fitting 22. And is fixed to the first outer cylinder portion 18. The outer rubber stopper 46 has an asymmetric structure with respect to a plane including the central axis of the first inner shaft bracket 22 perpendicular to the central axis of the second inner shaft bracket 36. It is positioned so as to be biased upward in FIG.

  When a load is input in the left-right direction in FIG. 5 while the torque rod 42 having such a structure according to the present embodiment is mounted on the vehicle, the first inner shaft fitting 22 is attached to the first outer cylinder portion 18. Thus, the rod body 12 is relatively displaced in the left-right direction in FIG. Then, as shown by a two-dot chain line in FIG. 5, when the first inner shaft fitting 22 is relatively displaced toward the outside of the rod body 12 with respect to the first outer cylinder portion 18, The first inner shaft member 22 and the first outer cylinder part 18 are brought into contact with each other through the outer rubber stopper 46 in a buffering manner.

  When the first inner shaft bracket 22 and the outer rubber stopper 46 are in contact with each other, the first inner shaft bracket 22 and the first outer cylinder portion 18 are not limited to the pair of connecting arm portions 30 and 30. The outer rubber stoppers 46 are also connected to each other. Therefore, in the torque rod 42 of the present embodiment, the spring component under vibration input is changed with respect to the spring component under standing by adding the spring component of the outer rubber stopper 46. .

  Here, since the outer rubber stopper 46 has an asymmetric structure with the central axis in the width direction of the rod main body 12 (up and down in FIG. 5), the first main body constituting the first rubber bush 14 The elastic main shaft extending in the axial direction of the rubber elastic body 44 is positioned off the radial center of the first inner shaft fitting 22. Thus, the elastic main shaft extending in the axial direction of the first main rubber elastic body 44 and the second main rubber elastic body 38 constituting the second rubber bush 16 under vibration input in the longitudinal direction of the rod main body 12. A plane including any of the elastic main axes extending in the axial direction: α (in other words, the elastic main axis of the spring component extending substantially in the longitudinal direction of the rod body 12) is inclined with respect to the longitudinal direction of the rod body 12.

  The plane: α is inclined in the width direction (up and down in FIG. 5) with respect to the central axis extending in the longitudinal direction of the rod body 12, so that the center of gravity of the mass component including the rod body 12 is plane: α It is positioned off the top. As a result, under the input of the main vibration, vibration displacement in the roll direction around the elastic main axis extending in the longitudinal direction of the rod body 12 is effectively generated, and the deterioration of the vibration isolation performance due to the rigid body resonance is suppressed. I can do it. The outer rubber stopper 46 is biased to one side in the circumferential direction of the first outer cylinder portion 18 with respect to the central axis extending in the longitudinal direction of the rod main body 12. Although the mass acts on the upper side in FIG. 5 with respect to the center of gravity of the mass component, in this embodiment, the mass of the outer rubber stopper 46 is sufficiently smaller than the mass of the entire mass component. The deviation of the center of gravity of the mass component due to the mass is suppressed to a level that can be ignored.

  Further, in the torque rod 42 shown in FIG. 5, the mounting position of the outer rubber stopper 46 is biased to one side in the circumferential direction of the first outer cylinder portion 18, so that the first main rubber elastic body 44 is moved. Although the structure in which the spring is asymmetric in the vertical direction in FIG. 5 is shown, for example, the same effect can be obtained by making the shape of the outer rubber stopper asymmetric in the rod width direction.

  Specifically, for example, in the torque rod 48 shown in FIG. 6, the outer rubber stopper 52 constituting the first main rubber elastic body 50 has a width direction (FIG. 6) with respect to the central axis of the rod main body 12. The upper and lower sides are asymmetrical. More specifically, the upper portion of the outer rubber stopper 52 in FIG. 6 protrudes inward in the longitudinal direction of the rod body 12 from the lower portion in FIG. It is positioned closer to the first inner shaft fitting 22 than the protruding tip of the side portion.

  When the torque rod 48 having such an asymmetric outer rubber stopper 52 is mounted on the vehicle, the first inner shaft fitting 22 is moved to the first outer cylinder portion 18 by vibration input in the longitudinal direction of the rod body 12. When the rod is relatively displaced outward in the longitudinal direction of the rod, first, the first inner shaft fitting 22 is first brought into contact with the upper portion of the outer rubber stopper 52 as shown by a two-dot chain line in FIG. . The spring of the first main rubber elastic body 50 is changed by adding the spring of the outer rubber stopper 52, and the elastic main shaft extending in the axial direction of the first main rubber elastic body 50 is the first inner shaft. The center axis of the metal fitting 22 is off the position. Thereby, the plane including the elastic main axes of the first and second main rubber elastic bodies 50 and 38 extending in the main vibration input direction (the axial direction of the first inner shaft metal fitting 22): α (the chain line in FIG. 6) Is inclined with respect to the longitudinal direction of the rod body 12.

  As described above, also in the torque rod 48 according to the present embodiment, the center of gravity of the mass component is positioned off the plane: α, and when the vibration is input in the main vibration input direction, the mass with respect to the elastic main shaft extending in the longitudinal direction of the rod. The vibration displacement in the roll direction due to the component bias is generated in a state coupled with the vibration displacement in the main vibration input direction, and the vibration transmission state in the main vibration input direction is deteriorated by the rigid resonance of the mass component. Can be suppressed.

  5 and 6 illustrate a structure in which the elastic main axis in the longitudinal direction of the rod of the spring component is inclined depending on the formation position and shape of the outer rubber stopper. For example, the formation position of the inner rubber stopper is the rod. By biasing in the width direction or making the shape of the inner rubber stopper asymmetric in the rod width direction, the elastic principal axis in the longitudinal direction of the spring component of the spring component is tilted under vibration input, causing vibration in the roll direction. It is possible to effectively realize the anti-vibration connecting rod according to the present invention.

  FIG. 7 shows a torque rod 54 as a third embodiment of the vibration-isolating connecting rod according to the present invention. The torque rod 54 includes a rod main body 56.

  As shown in FIG. 7, the rod main body 56 is a plane including the elastic main axes of the first and second main rubber elastic bodies 24 and 38 extending in the main vibration input direction: α (dashed line in FIG. 7). The first outer cylinder part 18 and the second outer cylinder part 20 extend so as to be connected to each other at a position away from the center, and in this embodiment, the first outer cylinder part 18 is formed to extend in a curved shape. Since the rod body 56 has such a structure, the center of gravity of the rod body 56 is biased off the plane: α, so that the center of gravity of the mass component is positioned off the plane: α. It has been. In the torque rod 54 according to the present embodiment, the first rubber bush 14 and the second rubber bush 16 are arranged so that their central axes extend in parallel to each other.

  In the torque rod 54 having such a structure, it is possible to improve the transmission state of the vibration in the main vibration input direction by using the vibration displacement of the mass component in the roll direction as in the above embodiments. Become. In particular, by using the rod body 56 having a relatively large mass, the center of gravity of the mass component can be easily biased.

  Further, the center of gravity of the mass component can be positioned off the elastic main shaft by tilting or biasing the elastic main shaft of the spring component. That is, FIG. 8 shows a torque rod 58 as a fourth embodiment of the vibration-isolating connecting rod according to the present invention. The torque rod 58 includes a first main rubber elastic body 60 that connects the first outer cylinder portion 18 and the first inner shaft fitting 22 to each other in the first rubber bush 59. The main rubber elastic body 60 further includes connecting arm portions 62 and 64.

  The connecting arm portions 62 and 64 are both positioned between the inner slit 26 and the outer slit 28 formed in the first main rubber elastic body 60 and extend in one radial direction. The connecting arm portions 62 and 64 are formed on both sides of the first inner shaft member 22 in the radial direction, and both end portions on the outer peripheral side are vulcanized and bonded to the first outer cylinder portion 18. In addition, the inner peripheral end is vulcanized and bonded to the first inner shaft fitting 22.

  Here, the connecting arm portion 62 has a smaller size in the circumferential direction than the connecting arm portion 64. As a result, the spring constant in the main vibration input direction (the shear direction which is the bush axis direction) is smaller in the connecting arm portion 62 than in the connecting arm portion 64. Therefore, the elastic main shaft of the first main rubber elastic body 60 extending in the main vibration input direction is inclined to the connecting arm portion 64 side with respect to the central axis of the first rubber bush 59.

  In the torque rod 58 having such a structure, the elastic main axis of the first main rubber elastic body 60 extending in the main vibration input direction of the first main rubber elastic body 60 is biased to one side in the radial direction. Accordingly, the center of gravity of the mass component including the rod main body 12 is determined from the plane including the respective elastic main axes of the first and second main rubber elastic bodies 60 and 38 extending in the main vibration input direction: α (dashed line in FIG. 8). It is positioned off.

  Therefore, the vibration displacement in the roll direction of the rod body 12 is effectively generated by the input of the main vibration, and the dynamic spring constant in the vertical vertical direction which is the main vibration input direction is based on the bounce resonance and the pitch resonance. Can be suppressed.

  As shown in FIG. 8, the portions of the first main rubber elastic body 60 that connect the first outer cylinder portion 18 and the first inner shaft bracket 22 to each other are connected arm portions 62 and 64. In addition to having different sizes in the circumferential direction as described above, the spring constants may be made different from each other by making the sizes of the connecting hooks different in the axial direction.

  That is, like the torque rod 66 shown in FIG. 9, the first main rubber elastic body 70 constituting the first rubber bush 68 has the connecting arm portions 72, 74. Even with the structure in which the thickness in the axial direction is smaller than the thickness in the axial direction of the connecting arm portion 74, the center of gravity of the mass component is positioned away from the elastic main shaft extending in the longitudinal direction of the rod body 12. I can do it.

  The first rubber bushing 68 of the torque rod 66 has a structure in which the first rubber bushing 14 constituting the torque rod 10 shown in the first embodiment is rotated by a predetermined angle in the circumferential direction. The opposing direction of the inner and outer rubber stoppers 32, 34 is inclined with respect to the longitudinal direction of the rod body 12. Thereby, the center of gravity of the mass component is positioned farther away from the elastic main shaft extending in the longitudinal direction of the rod by utilizing the difference in mass between the inner and outer rubber stoppers 32 and 34.

  Further, like the torque rod 76 shown in FIG. 10, the second main rubber elastic body 80 is also biased to one side in the axial direction with respect to the axial center of the second rubber bush 78. The plane including the elastic main axes of the first and second main rubber elastic bodies 24, 80 extending in the main vibration input direction: the mass center of gravity is deviated from α (the dashed line in FIG. 10). In addition, it is possible to improve the anti-vibration performance using the vibration of the mass component in the roll direction.

  Further, like the torque rod 82 shown in FIG. 11, the first and second rubber bushes 14, such that the central axis of the second rubber bush 84 is parallel to the central axis of the first rubber bush 14. 84, and the second main rubber elastic body 86 is partly and partially offset on the circumference between the second outer cylinder portion 20 and the second inner shaft fitting 36. The elastic main axis of the second main rubber elastic body 86 is biased, and the center of gravity of the mass component is positioned off the plane: α.

  That is, the second rubber bushing 84 constituting the torque rod 82 includes a second main rubber elastic body 86 having a substantially constant semicircular cross section and extending in the axial direction, as shown in FIG. In the radial direction between the second outer cylinder portion 20 and the second inner shaft bracket 36 with the central axis of the rod main body 12 interposed therebetween, the rod width direction (up and down in FIG. 11) is arranged. The second outer cylinder portion 20 and the second inner shaft metal fitting 36 are elastically connected to each other by a second main rubber elastic body 86 on one side in the direction).

  According to this, the elastic main shaft extending in the main vibration input direction of the second rubber bush 84 deviates from the central axis of the second rubber bush 84 and is biased to one side in the rod width direction. A plane including each elastic main axis of the first and second main rubber elastic bodies 24, 86 extending in the main vibration input direction: α (dashed line in FIG. 11) is inclined with respect to the central axis of the rod main body 12. It is done.

  In the torque rod 82, the center of gravity of the mass component including the rod body 12 is positioned near the center axis of the rod, and the center of gravity of the mass component is set at a position outside the plane: α. Thereby, the vibration displacement in the roll direction is caused to the mass component by the input of the main vibration, and the high dynamic spring due to the resonance in the main vibration input direction can be suppressed.

  FIG. 12 shows a torque rod 88 as a fifth embodiment of the vibration-isolating connecting rod according to the present invention. The torque rod 88 includes a rod body 90 and first and second rubber bushes 14 and 16 provided at both ends of the rod body 90.

  More specifically, in the torque rod 88, the radial center of the first rubber bush 14 and the axial center of the second rubber bush 16 are the width direction of the rod body 90 (vertical direction in FIG. 12). The position is shifted to The first outer cylinder portion 18 and the second outer cylinder portion 90 are integrally extended from the vicinity of one end in the axial direction of the second outer cylinder portion 20 constituting the second rubber bush 16. The cylinder part 20 is mutually connected.

  As described above, the first rubber bush 14 and the second rubber bush 16 are positioned so as to be displaced in the width direction of the rod main body 90, whereby the first and second main body rubbers extending in the main vibration input direction. A plane including elastic main axes of each of the elastic bodies 24 and 38: α (a chain line in FIG. 12) is inclined with respect to the central axis direction of the rod body 90 (left and right direction in FIG. 12).

  Thereby, the center of gravity of the mass component elastically supported by the first and second main rubber elastic bodies 24 and 38 is set at a position outside the plane: α, and by vibration input in the main vibration input direction, The mass component including the rod body 90 is caused to vibrate in the roll direction. The resonance frequency of the vibration in the main vibration input direction of the mass component is superimposed on the resonance frequency of the vibration in the roll direction of the mass component. It can be reduced by resonance vibration in the roll direction of the component.

  In addition, like the torque rod 92 shown in FIG. 13, the first rubber bush 14 is configured such that the central axis of the first rubber bush 14 extends parallel to the central axis of the second rubber bush 16. A structure in which the first outer cylinder portion 18 and the second outer cylinder portion 20 are connected to each other by a rod body 94 extending from one end portion in the axial direction of the first outer cylinder portion 18 may be employed.

  Also in the torque rod 92 having such a structure, as in the torque rod 88 according to the fifth embodiment, the elastic main axis of the spring component in which the center of mass of the mass component extends in the longitudinal direction of the rod body 94 is used as the width of the rod body 94. The resonance vibration in the main vibration input direction can be suppressed by utilizing the resonance in the roll direction of the mass component.

  Here, the fact that the vibration transmission in the resonance frequency region is suppressed by adopting the anti-vibration connecting rod having the structure according to the present invention is also shown by the actual measurement results shown in FIGS. The measurement results are briefly described below. In the measurement results shown in FIGS. 14 and 15, the measurement results related to the vibration proof connecting rod having the structure according to the present invention are measured using the torque rod 10 having the structure according to the first embodiment.

  That is, FIG. 14 shows the result of measuring the numerical value of the dynamic spring constant corresponding to the frequency of the input vibration, and the vibration displacement in the bounce direction and the pitch direction, which is the vibration displacement in the input direction of the main vibration, and the rod A plurality of measurement results are shown for each ratio of vibration displacement in the roll direction which is the rotation direction around the central axis of the main body, in other words, for each coupling rate of the bounce / pitch mode and the roll mode.

  First, in the graph of FIG. 14, the coupling rate of 0% is a structure in which vibration displacement in the roll direction of the rod body does not occur when a vibration load is input in the main vibration input direction. It is a measurement result which shows the case where the anti-vibration connection rod of is used. According to the graph of FIG. 14, when the coupling rate is 0%, the dynamic spring constant is remarkably increased to about 660 N / mm due to the resonance phenomenon in the frequency range of about 100 Hz to 110 Hz.

  Next, according to the graph of FIG. 14, when the coupling rate is 10% to 90%, in short, when the anti-vibration connecting rod according to the present invention is employed, the coupling rate is 0% compared to the comparative example. In addition, the peak value of the dynamic spring constant in the frequency range of about 100 Hz to 110 Hz is suppressed, and the transmission state of the input vibration to the connection target member (vehicle body or the like) is effectively improved. Thus, it is clear from the measurement results that the anti-vibration connecting rod having the structure according to the present invention has superior anti-vibration performance as compared with the anti-vibration connecting rod having the conventional structure.

  FIG. 15 is a graph showing how the dynamic spring constant in the vibration input direction of the spring component changes according to the difference in the coupling rate in the resonance frequency range. According to the graph shown in FIG. 15, the peak value of the dynamic spring constant gradually decreases as the coupling ratio approaches 50%. At the coupling ratio of 50%, the peak value of the dynamic spring constant increases. In the measurement results, the minimum is about 300 N / mm. For this reason, in the vibration-isolating connecting rod according to the present invention, the coupling rate is desirably set to 50%. In addition, even when the coupling rate is relatively small (large) such as 10% or 90%, the maximum value of the dynamic spring constant is suppressed to about 530 N / mm. As compared with the case of adopting (about 660 N / mm), the increase of the dynamic spring constant due to resonance is suppressed extremely effectively.

  As described above, by adopting the anti-vibration connecting rod of the structure according to the present invention, compared with the case of adopting the anti-vibration connecting rod of the conventional structure, the dynamic spring constant at resonance can be suppressed, It is also shown from the measurement results that transmission of input vibration to the connection target member can be prevented.

  In addition, the present invention can be applied not only in the case where only a high dynamic spring at the resonance frequency of the bounce vibration is a problem in the vibration proof connecting rod, but also at high resonance frequencies at each resonance frequency of the bounce vibration and the pitching vibration. It can also be applied when springing becomes a problem. Thus, in the case of having two resonance frequencies, it is desirable to tune so that the resonance frequency in the roll direction overlaps the resonance frequency on the low frequency side. This is because, for example, in a vibration-isolating connecting rod or the like that is attached to an automobile as shown in the embodiment, vibration on the low frequency side often has an adverse effect on the vibration-proof performance.

  Although several embodiments of the present invention have been described above, these are merely examples, and the present invention is not construed as being limited to specific descriptions in such embodiments.

  For example, in each of the embodiments described above, the outer cylinder member is formed using the arm eyes formed integrally at both ends of the rod body. However, the outer cylinder member is not necessarily formed integrally with the rod body. They may not be formed, and may be formed by a metal sleeve separate from the rod body. Specifically, for example, an integrally vulcanized molded product of a main rubber elastic body provided with an inner shaft bracket and the metal sleeve is formed, and both ends of the rod main body are fixed by fixing the metal sleeve to the rod main body. It is also possible to provide a cylindrical vibration isolator as an elastic connecting part.

  Further, in each of the above embodiments, the first rubber bush has a structure having inner and outer slits, and the second rubber bush has a structure having no slit. A slit may be formed in the bush and the spring characteristics may be tuned, or both rubber bushes may have a structure having no slit.

  In addition, the specific structure for positioning the center of gravity of the mass component shown in each of the above embodiments away from the elastic main axis of the spring component extending in the longitudinal direction of the rod body is merely an example, for example, By applying the structure having the mass metal fitting shown in the first embodiment to the anti-vibration connecting rod having the structure in which the spring characteristics according to the fourth embodiment are changed, The vibration displacement in the roll direction can be generated more advantageously.

  Moreover, in each said embodiment, although the structure which comprised the 1st, 2nd elastic connection part provided in the both ends of a rod main body with a cylindrical vibration isolator is shown, for example, At least one of the second elastic connecting portions can be configured by a bowl-shaped vibration isolator disclosed in Japanese Patent Application Laid-Open No. 2005-23973. Further, for example, a rubber mount that fixes one end of the rubber block to the rod body and fixes the other end to the anti-vibration connection target member may be employed as the elastic connection portion.

  Moreover, in each said embodiment, the torque rod for motor vehicles is illustrated as an anti-vibration connection rod of the structure according to this invention. However, the present invention is not necessarily applied only to the torque rod, and is preferably applied to, for example, a suspension arm. Furthermore, the anti-vibration connecting rod according to the present invention is not limited to an automobile, and may be employed as a train or other various connecting rods.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

Sectional drawing which shows the torque rod as 1st embodiment of this invention. The figure explaining the vibration displacement in the bounce direction of this torque rod. The figure explaining the vibration displacement in the pitch direction of this torque rod. The figure explaining the vibration displacement in the roll direction of this torque rod. Sectional drawing which shows the torque rod as 2nd embodiment of this invention. Sectional drawing which shows the torque rod as another one Embodiment of this invention. Sectional drawing which shows the torque rod as 3rd embodiment of this invention. Sectional drawing which shows the torque rod as 4th embodiment of this invention. Sectional drawing which shows the torque rod as another one Embodiment of this invention. Sectional drawing which shows the torque rod as another one Embodiment of this invention. Sectional drawing which shows the torque rod as another one Embodiment of this invention. Sectional drawing which shows the torque rod as 5th embodiment of this invention. Sectional drawing which shows the torque rod as another one Embodiment of this invention. The graph which shows the relationship between a vibration frequency and a dynamic spring constant. The graph which shows the relationship between a coupling rate and a dynamic spring constant.

Explanation of symbols

10: torque rod, 12: rod body, 14: first rubber bush, 16: second rubber bush, 18: first outer tube portion, 20: second outer tube portion, 22: first inner Shaft fitting, 24: first main rubber elastic body, 36: second inner shaft metal fitting, 38: second main rubber elastic body, 40: mass metal fitting

Claims (4)

A first elastic coupling portion in which the first vibration isolating member is assembled and a second elastic coupling portion in which the second vibration isolating member is assembled are provided at both ends in the longitudinal direction of the rod body. The elastic connection part is attached to one of the vibration isolation connection target members via the first vibration isolation member, and the vibration isolation connection target member via the second vibration isolation member of the second elastic connection part A vibration-proof connecting rod that elastically connects the two vibration-proof connection target members by being attached to the other,
In one vibration system constituted by a mass including the rod body and a spring by the first and second vibration isolating members, the center of gravity of the mass is relative to the elastic main axis of the spring extending in the longitudinal direction of the rod body. The main vibration input in the direction perpendicular to the axis of the rod body is biased to generate vibration in the roll direction around the elastic main axis with respect to the one vibration system. The mass in the one vibration system is such that the resonance frequency of the displacement vibration in the roll direction of the rod body overlaps the resonance frequency of the vibration in the main vibration input direction of the rod body generated in the one vibration system. And an anti-vibration connecting rod, wherein the spring is set. The resonance frequency of the displacement vibration in the roll direction of the rod body is expressed by the following equation with respect to the resonance frequency of vibration in the main vibration input direction of the rod body generated in the one vibration system by the main vibration input. The anti-vibration connecting rod according to claim 1, wherein the coupling ratio: W is set to 10% to 90%.

In the above equation, R is the main vibration input direction component in the displacement vector of the mass center of gravity, R ^T is the transposed vector of R, M is the mass matrix of the mass, and Q is the displacement vector of the mass center of gravity. It is a rotational direction component, Q ^T is a transposed vector of Q, and J is a mass moment of inertia matrix.   The first elastic connecting portion and the second elastic connecting portion are each a cylindrical vibration damping device in which an inner shaft member and an outer cylindrical member are connected by a main rubber elastic body. The anti-vibration connecting rod described in 1.   The center of gravity of the rod body is set at a position deviated from a plane including elastic main axes of the first vibration isolation member and the second vibration isolation member extending in the main vibration input direction. The vibration-isolating connecting rod according to any one of 1 to 3.

Images