JP4066456B2 - Cylindrical vibration isolator - Google Patents

Description

  The present invention relates to a cylindrical vibration isolator formed by connecting an inner shaft member and an outer cylindrical member spaced apart on the outer peripheral side thereof by a main rubber elastic body, such as an engine mount, a body mount, a suspension bush, etc. for an automobile. The present invention relates to a cylindrical vibration isolator that can be employed in the present invention.

  The cylindrical vibration isolator as described above is arranged on a vibration transmission path by being attached to one member to which the inner shaft member and the outer cylinder member are vibration-coupled, and is used as an engine mount for an automobile. When vibration in the direction perpendicular to the axis is input between the inner shaft member and the outer cylindrical member, the main rubber elastic body is repeatedly elastically deformed, and a vibration isolation effect based on the spring characteristics and damping characteristics is exhibited.

  By the way, since the main rubber elastic body itself has a spring component and a mass component, a surging phenomenon occurs in a specific frequency region during elastic deformation. When this surging phenomenon occurs in the main rubber elastic body, there is a problem in that the vibration transmission rate between the inner shaft member and the outer cylinder member increases, and the vibration isolation performance decreases.

  In order to deal with such a problem, it may be considered to use a dynamic damper or a mass damper. However, in these damper mechanisms, the effect can be effectively exhibited only in a specific narrow tuning frequency range. Therefore, it is difficult to tune the damper mechanism. Further, when the spring characteristic of the main rubber elastic body changes due to a temperature change or the like and the surging frequency changes, there is a problem that the damper mechanism tuned to the initial surging frequency becomes difficult to function effectively.

  In view of this, the applicant of the present application previously disclosed in Japanese Patent Application Laid-Open No. 2002-227721 (Patent Document 1) the vibration transmissibility caused by the surging phenomenon of the main rubber elastic body using a damping contact-type vibration damping device. We proposed a vibration isolator with a novel structure that reduces or avoids deterioration. In this vibration damping device, a housing portion is formed on the main rubber elastic body, and independent mass members are incorporated in the housing so as to be independently displaceable, and contact surfaces of the independent mass members and the housing portion are formed of a rubber material. It is structured. At the time of vibration input, the independent mass member repeatedly strikes the housing part with the abutment surface made of a rubber material, so that a relatively wide frequency range is obtained based on sliding friction at the time of abutment and energy loss due to collision. Thus, an effective vibration damping effect can be exhibited over a long period of time, and the surging phenomenon of the main rubber elastic body can be suppressed.

  However, as a result of further investigation by the present inventor, the cylindrical vibration isolator using the damping contact type vibration damping device according to the earlier application of the applicant of the present application is still improved. It became clear that there was room for power. Here, the inherent problems are (i) improvement of the suppression effect of the surging phenomenon of the main rubber elastic body by the damping contact type damping device, and (ii) a spring by securing an effective free length in the main rubber elastic body. It is compatible with both improvement of characteristics such as tuning freedom of characteristics and durability.

  That is, in order to more effectively obtain the effect of suppressing the surging phenomenon of the main rubber elastic body exhibited by the damping contact damping device, it is necessary to sufficiently secure the mass of the independent mass member. For that purpose, the housing part formed in the main rubber elastic body must be enlarged. However, when this housing part is enlarged, the volume of the main rubber elastic body is reduced accordingly, the effective free length of the main rubber elastic body is reduced, and the degree of freedom in tuning the spring characteristics of the main rubber elastic body It is easy to cause a problem of deterioration and durability. In particular, when the outer size of the vibration isolator is limited due to restrictions on the mounting space such as an engine mount for automobiles, it becomes a bigger problem.

Japanese Patent Laid-Open No. 2002-227921

  Here, the present invention has been made in the background as described above, and the problem to be solved is a damping contact type while sufficiently securing the volume and effective free length of the main rubber elastic body. A cylindrical vibration isolator having a novel structure in which the mass of the mass member in the vibration damping device can be set large, and thereby the effects of improving both the characteristics (i) and (ii) can be achieved at the same time. Is to provide.

  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. In addition, 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 can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized on the basis of.

That is, according to the present invention, an outer cylinder member is disposed apart from the outer peripheral side of the inner shaft member, and a cylinder in which the axially perpendicular opposed surfaces of the inner shaft member and the outer cylinder member are connected by a main rubber elastic body. In the vibration isolator, a rigid support rod member that is located in an intermediate portion between opposed surfaces of the inner shaft member and the outer cylinder member in a direction perpendicular to the axis and extends through the main rubber elastic body in the axial direction. the provided while allowed to wear vulcanization against the outer peripheral surface of the supporting rod member to the rubber elastic body, to protrude outward the axial end portion of the supporting rod member from rubber elastic body, such The separate mass member at the end formed independently of the support rod member with respect to the axially projecting portion is assembled so as to be relatively displaceable in the direction perpendicular to the axial direction, and the mutual contact between the support rod member and the separate mass member at the end is fixed. At least one of the contact surfaces By forming the contact rubber made of rubber elastic material, the support rod member and the separate mass member at the end portion are substantially separated from the contact state via the contact rubber when the vibration is input in the direction perpendicular to the axis. By repeating the above, the end separate mass member is configured to constitute a damping contact-type end vibration damping device that repeatedly strikes the support rod member.

  In the cylindrical vibration isolator having the structure according to the present invention, the damping contact type end vibration damping device is constituted by the axially protruding portion of the support rod member and the separate end mass member assembled thereto. Composed. In other words, the end vibration damping device is formed to be positioned substantially outside in the axial direction with respect to the main rubber elastic body. Therefore, even if the support rod member and the separate mass at the end are enlarged, they are not provided inside the main rubber elastic body, and thus have a direct effect on the volume and effective free length of the main rubber elastic body. It does not affect

  Therefore, according to the present invention, while the volume and effective free length of the main rubber elastic body are sufficiently secured, the mass of the separate end mass member is set to be large, and the damping by the damping contact type end damping device is performed. The vibration effect can be further improved. That is, the vibration isolating performance such as the spring characteristics of the main rubber elastic body can be tuned with a large degree of freedom, and the durability of the main rubber elastic body can be advantageously ensured. At the same time, it is possible to set the mass of the separate mass member at the end in the end damping device to be sufficiently large, and to more effectively suppress the deterioration of the vibration proof performance due to the surging of the main rubber elastic body. .

  Moreover, since the support rod member against which the separate end mass member strikes is disposed through the main rubber elastic body in the axial direction and fixed to the main rubber elastic body, the end mass member is supported by the support rod. Impact energy and damping force associated with hitting the member are efficiently applied to the main rubber elastic body through the support rod member. That is, although the end mass member is disposed at a position that is axially disengaged from the main rubber elastic body, the impact energy and damping force due to striking against the support rod member are not affected by the main rubber elastic body. It can be effectively transmitted over a wide range in the entire axial direction of the body, and the effect of reducing the surging phenomenon with respect to the main rubber elastic body is effectively exhibited.

  Further, in the present invention, the position where the end portion separate mass member hits the support rod member is positioned far from the axial elastic center of the main rubber elastic body in the axial direction. Therefore, the main rubber elastic body has a moment with the effective arm length as the distance from the elastic center in the axial direction of the main rubber elastic body to the striking part due to the contact force of the separate end mass member against the support rod member. Can be affected. Therefore, even when elastic deformation including a component in the twisting direction is generated with respect to the main rubber elastic body, the vibration suppression effect due to the contact of the separate end mass member with the support rod member is exerted on the main rubber elastic body. On the other hand, it can act effectively via the support rod member. As a result, an effective suppression effect is exhibited even in a surging phenomenon including a deformation component in the twisting direction in the main rubber elastic body.

  In the present invention, for example, the natural frequency of one vibration system composed of a spring system composed of contact rubber and a mass system composed of separate end mass members is specified for the purpose of vibration isolation. By tuning to the vibration frequency region, the separate mass member at the end can be positively jumped and hit against the support rod member using the resonance phenomenon of the vibration system. By using the resonance magnification in this way, even when the input vibration acceleration is small, it is possible to displace / contact the abutment surface by greatly displacing the separate mass member at the end, and end vibration suppression The effect of reducing the vibration transmissibility of the main rubber elastic body due to the vibration damping action of the device can be obtained more effectively with respect to vibrations in a specific frequency range.

  Moreover, in the cylindrical vibration isolator constructed according to the present invention, the axially protruding portions are provided at both axial ends of the support rod member, respectively, and the end portions are opposed to both axially protruding portions. A mode in which separate mass members are respectively assembled and the contact-type vibration damping device is formed symmetrically at both axial ends is preferably employed.

  According to such an aspect, it is possible to cause the action by the contact of the separate end mass member to the both sides in the axial direction of the support rod member substantially simultaneously or with a phase difference. As a result, the main rubber elastic body is caused to exert a force generated by striking the pair of end mass members via the support rod member, for example, in a translational motion in the same direction or in a moment in the opposite direction. I can do it. Therefore, it is possible to more efficiently and stably act on the main rubber elastic body with the vibration damping effect by the end vibration damping device, and thus the surging phenomenon reducing effect on the main rubber elastic body. At that time, the elastic deformation of the main rubber elastic body is not only in the direction perpendicular to the axis, but also in the twisting direction and the twisting direction, the vibration damping effect by the end vibration control device is effectively exhibited, and the main body The deterioration of the vibration proof property due to the surging phenomenon of the rubber elastic body can be reduced or avoided.

  Moreover, in the cylindrical vibration isolator having a structure according to the present invention, the separate end mass member is annular, and the annular end separate mass member is located with respect to the axially protruding portion of the support rod member. Thus, an embodiment in which the contact surface is constituted by the outer peripheral surface of the support rod member and the inner peripheral surface of the annular separate mass member by being assembled in an extrapolated state is suitably employed.

  According to such an aspect, since the contact surface is formed on the inner peripheral surface of the end-part separate mass member, compared to the case where the contact surface is formed on the outer peripheral surface of the end-part separate mass member. In the limited space for disposing the end vibration damping device, it is possible to secure the mass mass more advantageously by setting the end separate mass member sufficiently large on the outer peripheral side.

  Alternatively, in the cylindrical vibration isolator having a structure according to the present invention, a hollow structure housing is formed in the axially protruding portion of the support rod member, and the separate mass member at the end portion is formed in the housing. A mode in which the abutting surface is configured by the inner peripheral surface of the housing and the outer peripheral surface of the separate mass member at the end by housing and assembling is also preferably employed.

  According to such an aspect, since the contact surface is formed on the outer peripheral surface of the separate end mass member, compared with the case where the contact surface is formed on the inner peripheral surface of the separate end mass member. In the limited space for disposing the end damping device, the effective contact area of the contact surface between the end separate mass member and the support rod member can be set large, and the end separate mass member It becomes possible to realize a more stable hitting against the rod member.

  Further, in the cylindrical vibration isolator having the structure according to the present invention, even when the contact surface is formed on either the inner peripheral surface or the outer peripheral surface of the separate end mass member, the contact surface is not It is desirable to employ a cover structure that substantially blocks from space.

  As a result, it is possible to avoid a decrease in the damping effect due to the entry of foreign matter between the contact surfaces. When realizing such a cover structure, in particular, a configuration in which the abutting surfaces are formed on the outer peripheral surface of the separate mass member is also adopted, and a hollow structure formed at the end of the support rod member By using the housing and making the housing substantially hollow closed structure, this can be easily achieved without requiring a special member.

  Further, in the cylindrical vibration isolator having a structure according to the present invention, both the support rod member and the separate mass member at the end are formed of a metal material, and the axially protruding portion of the support rod member A mode in which a rubber elastic body layer is formed on and attached to at least one of the separate end mass members, and the contact rubber is constituted by the rubber elastic layer is preferably employed.

  According to such an aspect, the mass mass of the separate mass member at the end made of the metal material can be more advantageously secured with a compact size. When the rubber elastic body layer is adhered to the contact surface of the support rod member, the main rubber elastic body is turned thinly to the axially protruding portion along the surface of the support rod, and the main rubber is A rubber elastic body layer can be formed integrally with the elastic body.

  Moreover, in the cylindrical vibration isolator constructed according to the present invention, the central housing is formed by forming a hollow intermediate structure in the axial direction of the support rod member positioned inside the main rubber elastic body. In addition, the central separate mass member formed independently from the support rod member in the central housing is assembled so as to be relatively displaceable in the direction perpendicular to the axis, and the contact surface between the support rod member and the central separate mass member is mutually By forming at least one of them with a contact rubber made of a rubber elastic material, the support rod member and the central mass member are substantially in contact with the contact rubber through the contact rubber at the time of vibration input in the direction perpendicular to the axis. A configuration in which a damping contact-type central vibration damping device in which the central mass member repeatedly hits the support rod member by repeating various separation states is suitably employed. .

  According to such an aspect, the damping contact-type vibration damping device can be obtained using not only the external space outside the axial direction of the main rubber elastic body but also the internal space of the intermediate intermediate portion of the main rubber elastic body. It becomes possible to arrange. Therefore, by effectively using both of these spaces, a more effective damping effect as a whole can be obtained by combining the end damping device and the central damping device.

  Further, in the cylindrical vibration isolator having a structure according to the present invention, in the main rubber elastic body, the wall extending through the axial direction between the opposed surfaces of the inner shaft member and the outer cylinder member in the direction perpendicular to the axis. A mode in which at least one hole is formed and the main rubber elastic body is provided with a pair of support rod members so as to be located on both sides in the circumferential direction across the wall hole. Adopted.

  According to such an aspect, by forming the hollow hole, in the cylindrical vibration isolator, adjustment of the relative spring characteristics between the plurality of axes perpendicular to each other and the relative relationship between the axes and the axes perpendicular to each other Spring characteristics can be adjusted. At that time, the main rubber elastic body is surging to the main rubber elastic body by substantially dividing the main rubber elastic body in the circumferential direction at one, two, or three or more locations on the circumference by forming a hollow hole. It tends to occur. Therefore, in this embodiment, since the damping action by the damping contact type damping device is directly applied to both the circumferential direction both sides of the lightening hole, which is particularly prone to surging, the main rubber Reduction of the vibration proof performance due to surging of the elastic body is realized more effectively.

  Further, in the cylindrical vibration isolator having a structure according to the present invention, the support rod member and the end portion separate mass member are positioned on the same central axis with each other. A continuous gap is formed across the entire circumference in the circumferential direction between the contact surfaces of the separate mass members, and the end separate mass members are perpendicular to the support rod member in the direction perpendicular to the axis. A mode in which it completely jumps away and repeatedly hits is preferably adopted.

  According to such an aspect, when the separate mass member at the end is brought into contact with the support rod member at both stroke end portions in the reciprocating direction and repeatedly hits, the support rod member of the separate mass member at the end The stroke length and the relative displacement speed with respect to can be set to be larger, and the separate end mass member can be hit against the support rod member with larger energy. Therefore, it is possible to obtain an effective suppression effect against the surging phenomenon of the main rubber elastic body having particularly large energy.

  Alternatively, in the cylindrical vibration isolator having the structure according to the present invention, the support rod member and the end of the support rod member and the end separate mass member are positioned on the same central axis. The contact surfaces of the separate mass members are in contact with each other substantially without any gap over the entire circumference in the circumferential direction, and when the vibration is input, the support rod member and the end are in contact with each other based on elastic deformation of the contact rubber. A mode in which a gap is generated between the contact surfaces of the separate mass members so that the end separate mass members repeatedly strike the support rod member in a direction perpendicular to the axis is also preferably employed. The

  According to such an aspect, it is possible to avoid adverse effects such as an unnecessary displacement of the separate end mass member and a hitting sound caused by a hit. It is also possible to tune the displacement of the separate end mass member using the elasticity of the contact rubber.

  As is clear from the above description, in the cylindrical vibration isolator having the structure according to the present invention, the damping contact type vibration damping device capable of exhibiting the suppression effect on the surging phenomenon of the main rubber elastic body is substantially provided. In particular, it can be configured outside the main rubber elastic body. Therefore, by setting a large mass on the separate end mass member, the surging suppression effect of the main rubber elastic body can be obtained more advantageously, and the main rubber elastic body volume and effective free length are sufficiently secured. Thus, good spring characteristics and durability can be realized.

  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, FIGS. 1 to 3 show an automotive engine mount 10 as a cylindrical vibration isolator according to a first embodiment of the present invention. In the engine mount 10, an inner cylinder fitting 12 as a first attachment member (inner shaft member) and an outer cylinder fitting 14 as a second attachment member (outer cylinder member) are elastically connected by a main rubber elastic body 16. Have a structure. And while the inner cylinder metal fitting 12 is attached to the power unit side which is not shown in figure, and the outer cylinder metal fitting 14 is attached to the vehicle body side which is not shown in figure, the power unit is made to carry out vibration-proof support with respect to a vehicle body. In the present embodiment, the vehicle is mounted on the automobile in a state where the vertical direction in FIG. 1 is a substantially vertical vertical direction.

  More specifically, the inner cylinder fitting 12 has a small-diameter cylindrical shape formed of a rigid material such as steel or aluminum alloy. And this inner cylinder metal fitting 12 is fixed with respect to the power unit which is not shown in figure by rods, such as a volt | bolt inserted in the inner hole 18. As shown in FIG. In addition, an outer cylindrical metal member 14 is disposed on the outer side in the radial direction of the inner cylindrical metal member 12 so as to be separated by a predetermined distance.

  The outer cylinder fitting 14 is made of a rigid material such as steel or aluminum alloy, and has a large-diameter cylindrical shape as a whole. Then, the outer cylinder fitting 14 is pressed into a press-fitting hole formed on the vehicle body side (not shown), or is pressed by an appropriate bracket having a fixing portion on the vehicle body side. It is fixed to the body directly or via a bracket.

  A main rubber elastic body 16 is disposed between the radially opposing surfaces of the inner and outer cylinder fittings 12 and 14. The main rubber elastic body 16 has a thick cylindrical shape as a whole. The inner peripheral surface of the main rubber elastic body 16 is vulcanized and bonded to the outer peripheral surface of the inner cylindrical metal member 12, and the outer peripheral surface is the outer cylindrical metal member 14. Is vulcanized and bonded to the inner peripheral surface of Thereby, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the inner and outer cylindrical fittings 12 and 14.

  Further, the main rubber elastic body 16 sandwiches the inner cylinder fitting 12 in the input direction (up and down direction in FIG. 1) of main loads (including static power unit load and dynamic vibration load to be vibrated). On both sides, two slits 20 and 22 are formed as hollow holes. The upper slit 20 has a crescent-shaped cross-sectional shape extending over a substantially half circumference in the circumferential direction, while the lower slit 22 has a substantially sector-shaped cross-section having a shorter circumferential length than the upper slit 20. Yes. The upper and lower slits 20 and 22 are formed so as to penetrate in a substantially constant cross-sectional shape in the axial direction.

  As a result, the main rubber elastic body 16 is allowed to exist substantially only between the upper and lower slits 20 and 22 between the inner and outer cylindrical fittings 12 and 14, and straddles between the inner and outer cylindrical fittings 12 and 14. A pair of elastic connection portions 24, 24 extending in the radial direction and elastically connecting the inner and outer cylinder fittings 12, 14 are formed. The pair of elastic connecting portions 24, 24 as a whole have a substantially reverse V-shaped cross-sectional shape, and the inner cylindrical metal fitting 12 penetrates and is fixed to the V-shaped top portion in the axial direction. The outer cylindrical metal fitting 14 is fixed to the entire V-shaped end faces.

  In particular, in the present embodiment, each elastic connecting portion 24 is formed between the inner cylinder fitting 12 and the outer cylinder fitting 14 so as to extend in the radial direction with a substantially constant cross-sectional shape. Further, the inner cylinder fitting 12 is eccentric by a predetermined amount in the radial direction (upward in FIG. 1) with respect to the outer cylinder fitting 14, and the static load for sharing and supporting the power unit in the mounted state is radial. As a result, the inner and outer cylindrical fittings 12 and 14 are positioned on substantially the same central axis. As is apparent from the drawings, in this embodiment, in the radial direction (downward in FIG. 1) in which the inner cylinder fitting 12 is displaced relative to the outer cylinder fitting 14 when such a static load is applied. A pair of elastic connection parts 24 and 24 are expanded toward the reverse V shape. Thereby, the elastic connecting portions 24 and 24 are pre-compressed by the initial load, and the generation of tensile stress in the elastic connecting portions 24 and 24 is reduced or avoided, thereby improving the durability.

  In addition, in this embodiment, the outer peripheral surface of the inner cylinder metal fitting 12 is made into a deformed shape over the full length of an axial direction. Specifically, the lower half-periphery portion in the mounted state has a tapered axial cross-sectional shape that gradually decreases in width toward the lower side. That is, the tapered both side surfaces 26, 26 have a substantially flat surface shape that spreads substantially perpendicular to the elastic main shaft extending in the radial direction of the elastic connecting portions 24, 24. Thereby, when the inner cylinder fitting 12 is displaced downward by the shared support load of the power unit, a compressive stress is more effectively generated in a wider portion of the elastic connecting portions 24, 24. .

  The upper and lower slits 20 and 22 are provided with upper and lower stopper portions 28 and 30 that protrude from the outer cylinder fitting 14 toward the inner cylinder fitting 12 side. In particular, in the present embodiment, the upper and lower stopper portions 28 and 30 are both connected to the main rubber elastic body 16 by a thin rubber layer deposited on the inner peripheral surface of the outer cylinder fitting 14. It is integrally formed with the rubber elastic body 16.

  Then, when an impact load is applied between the inner and outer tube fittings 12 and 14 when the vehicle goes over a step or travels on a rough road, the inner tube fitting 12 and the outer tube fitting 14 are brought into contact with each other via the stopper portions 28 and 30. It can be touched. Thereby, the relative displacement amount in one radial direction (vertical direction in FIG. 1) which is the main vibration input direction of the inner cylinder fitting 12 and the outer cylinder fitting 14 is limited in a buffering manner.

  Further, a support rod 32 as a support rod member is fixed to each of the pair of elastic connecting portions 24 and 24 in the main rubber elastic body 16. The support rod 32 may be a hard synthetic resin material, but preferably is formed of a highly rigid metal material such as steel. The support rod 32 has a rod shape extending substantially straight, and in this embodiment, the support rod 32 extends with a substantially constant circular cross-sectional shape. Further, the axial length of the support rod 32 is made larger than the axial length of the main rubber elastic body 16.

  Each support rod 32 has a substantially central portion in the connecting direction (free length direction) of the inner and outer cylindrical fittings 12 and 14 in each elastic connecting portion 24, that is, the inner and outer cylindrical fittings 12 and 14 connected by the elastic connecting portion 24. In the substantially central portion between the opposing surfaces of the connecting parts, the inner and outer cylindrical metal fittings 12 and 14 are disposed so as to penetrate in the axial direction. In particular, in the present embodiment, both end portions in the axial direction of the support rod 32 are projected from the end surface in the axial direction of the main rubber elastic body 16 to the outside in the axial direction by a predetermined length. In particular, in the present embodiment, the inner cylinder fitting 12 is longer than the outer cylinder fitting 14, and both axial ends of the inner cylinder fitting 12 are protruded to both axial sides of the outer cylinder fitting 14. The axial length of the support rod 32 is about the middle between the inner cylinder fitting 12 and the outer cylinder fitting 14, and protrudes from the both sides of the outer cylinder fitting 14 in the axial direction by a predetermined length.

  It should be noted that the outer diameter of the support rod 32 is sufficiently smaller than the free length direction of the main rubber elastic body 16, and the circumferential width of the main rubber elastic body 16 (inner and outer cylinder fittings orthogonal to the free length direction). 12 and 14 in the circumferential direction). Thus, even if the support rod 32 is inserted into the main rubber elastic body 16, the volume of the main rubber elastic body 16 is sufficiently secured around the support rod 32 so that stress concentration does not become a problem. ing.

  The support rod 32 is set together with the inner and outer cylindrical fittings 12 and 14 with respect to the molding cavity of the vulcanization mold of the main rubber elastic body 16, and simultaneously with the molding of the main rubber elastic body 16, 14 is vulcanized and bonded to the main rubber elastic body 16. In other words, the support rod 32 is vulcanized and bonded to the main rubber elastic body 16 on the substantially entire outer peripheral surface of the portion penetratingly disposed inside the main rubber elastic body 16.

  Further, the projecting end portions 34 and 34 as the end portions in the axial direction of the support rod 32 projected from both sides in the axial direction of the main rubber elastic body 16 are configured so as to cover substantially the entire outer peripheral surface. A thin contact rubber layer 36 is formed as a rubber elastic layer. The abutting rubber layer 36 is integrally formed with the main rubber elastic body 16 by the main rubber elastic body 16 extending thinly to the outer peripheral surfaces of both end portions in the axial direction of the support rod 32. Yes.

  Further, annular float masses 38, 38 as end-part separate mass members are assembled to the protruding ends 34, 34 of the support rod 32 in an extrapolated state, respectively. Each protruding end 34, 34 is formed with an annular locking groove extending in the circumferential direction near the protruding tip, and an E-shaped retaining ring 39 as a retaining member is fitted into the locking groove. It is locked. The E-shaped retaining ring 39 has an outer diameter larger than the inner diameter of the annular float mass 38, and prevents the annular float mass 38 from coming out from the protruding end 34. In addition to the E-type retaining ring 39 illustrated as an example, the retaining member may employ various structures such as washers such as a C-shaped retaining ring, nuts such as a speed nut and clip nut, and pins such as a snap pin. .

  The annular float mass 38 has an annular block shape, and the inner diameter is larger than the outer diameter of the protruding end 34 of the support rod 32. Particularly in this embodiment, the inner diameter dimension of the annular float mass 38 is made larger than the outer diameter dimension of the contact rubber layer 36 attached to the outer peripheral surface of the protruding end portion 34. Further, the axial length of the annular float mass 38 is shorter than the axial length of the projecting end portion 34, and the annular float mass 38 is slightly extended in the axial direction under the extrapolated state to the projecting end portion 34. Displaceable.

  As a result, the annular float mass 38 can be independently displaced relative to the protruding end 34 in the direction perpendicular to the axis without being constrained at both axial end surfaces. As shown in FIGS. 1 and 2, the gravity float is ignored and the annular float mass 38 is attached to the protruding end 34 under the condition that the annular float mass 38 is positioned on the same central axis as the support rod 32. Between the outer peripheral surface of the contact rubber layer 36 and the inner peripheral surface 40 of the annular float mass 38, a gap δ having a substantially constant size is formed over the entire circumference in the circumferential direction. .

  In other words, as shown in FIG. 4, the annular float mass 38 is eccentrically positioned downward with respect to the projecting end 34 under the state of being hooked on the projecting end 34 by the action of gravity. It has become. Under such a latched state, the inner peripheral surface 40 of the annular float mass 38 is in contact with the contact rubber layer 36 at the vertical upper end of the protruding end 34, while the contact rubber is at the vertical lower end of the protruding end 34. It is spaced from the surface of the layer 36 by a predetermined gap: 2δ.

  The gap dimension δ between the abutting rubber layer 36 of the projecting end 34 and the axially perpendicular surface of the annular float mass 38 is for obtaining a vibration suppression effect (that is, a surging suppression effect) described later more advantageously. In addition, it is desirable to set 0.02 mm ≦ 2δ ≦ 1.6 mm, and more preferably 0.04 ≦ 2δ ≦ 1.0 mm. Thereby, the stroke of the annular float mass 38 is increased to some extent, and the relative displacement speed in the direction perpendicular to the axis with respect to the protruding end 34 is advantageously ensured. In addition, even when the axially perpendicular displacement is relatively small, the annular float mass 38 strikes against the contact rubber layer 36 of the protruding end 34 at the displacement ends on both sides of the axially perpendicular direction.

  In the support rod 32, the abutting rubber layer 36 constituting the abutting surface against which the annular float mass 38 abuts has a Shore D hardness of ASTM standard D2240, preferably 80 or less, more preferably 40-60. It is desirable to be formed of various known rubber materials. Thereby, the hitting sound when the annular float mass 38 strikes is prevented, and the vibration control effect described later can be obtained more advantageously.

  That is, in the engine mount 10 having the above-described structure, when vibration in the direction perpendicular to the axis is input between the inner cylinder fitting 12 and the outer cylinder fitting 14 in the mounted state, the elasticity of the main rubber elastic body 16 is increased. The connecting portions 24 and 24 are elastically deformed.

In this case, the elastic deformation of the elastic connecting portion 24 is caused to include compressive deformation in the direction perpendicular to the axis of the inner and outer cylindrical fittings 12 and 14 and shear deformation in the circumferential direction, but particularly in a shear direction in which the spring constant is relatively small. In some cases, the frequency range where surging occurs in the elastic connecting portion 24 becomes a vibration frequency range that causes a problem in an automobile. That is, the elastic connecting portion 24 has an effective free length of L, an effective mass mass per unit length in the free length direction (substantially perpendicular to the axis of the mount), M, and the main rubber elastic body 16 (elastic connecting portion 24). If the dynamic shear spring constant is K, it has a primary natural vibration frequency: fn expressed by the following (Equation 1) in the shear direction.
fn = (1 / 2L) √ (K / M) (Formula 1)

  In the engine mount 10 as described above, since the inner and outer cylinder fittings 12 and 14 are elastically connected by the pair of elastic connecting portions 24 and 24, the elastic deformation of the pair of elastic connecting portions 24 and 24 is directly performed. If the amplitude of the elastic connecting portions 24, 24 is increased due to the surging of the elastic connecting portions 24, 24, the vibration isolating performance may be lowered in the specific frequency range.

  Here, in the engine mount 10 of the present embodiment, the support rod 32 is also displaced integrally with the elastic connecting portion 24 in accordance with the elastic deformation in the shearing direction in which the surging phenomenon occurs in the elastic connecting portions 24 and 24. .

  As a result, particularly when surging is induced in the elastic connecting portion 24, the elastic connecting portion 24 is vibrated with a large amplitude in the shearing direction, and the elastic float 24 is supported by the annular float mass 38 via the support rod 32. A large external force is exerted as an exciting force in a direction perpendicular to the axis. As a result, the independent float mass 38 is displaced so as to jump in the direction perpendicular to the axis from the projecting end portion 34 of the support rod 32, and in the shearing deformation direction (vibration direction) of the elastic connection portion 24, The projecting tip portion 34 of the fixed support rod 32 is abutted (contacted). Based on repeated contact (contact) of the independent float mass 38 with the protruding tip 34, the elastic elastic displacement 16 (vibration displacement) of the main rubber elastic body 16 (the pair of elastic connecting portions 24, 24). ), The surging in the main rubber elastic body 16 can be suppressed.

  Therefore, in the engine mount 10 of the present embodiment having the above-described structure, the reduction in the vibration proof performance due to the surging of the main rubber elastic body 16 in the specific frequency range can be reduced or avoided. Thus, the vibration isolation effect based on the elastic properties of the main rubber elastic body 16 can be stably exhibited against vibrations in a wide frequency range. As is apparent from this, in the present embodiment, the support rod 14 fixed to the main rubber elastic body 16 and the independent float mass 38 brought into contact with the protruding tip 34 formed with the support rod 14. A damping contact-type end vibration damping device is configured.

  In particular, in the present embodiment, the independent float masses 38 and 38 that constitute the damping contact-type end vibration damping device are disposed outside the main rubber elastic body 16, so that the volume of the main rubber elastic body 16 can be reduced. It is possible to set the mass of the independent float mass 38 to a large value while ensuring sufficient. Therefore, it is possible to improve the vibration damping effect based on the hitting of the independent float mass 38 while avoiding problems such as the vibration proofing performance and the decrease in durability due to the decrease in the volume of the main rubber elastic body 16. The vibration damping action (surging prevention effect) based on the contact of the independent float mass 38 that is caused to act on the main rubber elastic body 16 via the support rod 14 can be achieved more effectively.

  Further, since the contact portion of the independent float mass 38 is set at a position that is greatly separated in the axial direction from the axial elastic center of the main rubber elastic body 16, the elastic main rubber elastic body 16 is based on the hit. The moment exerted on the elastic body 16 can effectively act on the elastic deformation of the elastic body rubber elastic body 16 in the twisting direction. Therefore, it is possible to obtain an effective suppression effect against a surging phenomenon including a component in the twisting direction of the main rubber elastic body 16. According to the examination result of the present inventor, it has been confirmed that the main rubber elastic body 16 of the engine mount 10 is elastically deformed in the twisting direction even under normal driving conditions in an automobile.

  In addition, in this embodiment, since the damping contact-type end vibration damping device is configured with a substantially symmetrical structure on both axial sides of the main rubber elastic body 16, both end vibration dampings are provided. In the apparatus, due to the phase difference when each independent float mass 38 abuts against the protruding tip 34 of the support rod 32, the main rubber elastic body 16 has a large axis perpendicular direction which is the same direction on both sides in the axial direction. As a contact force or as a contact force in a large twisting direction opposite in the axial direction on both sides, the contact force is effectively applied as a contact force synthesized at an appropriate ratio based on the phase difference. Accordingly, in response to the elastic deformation mode of the main rubber elastic body 16 caused in various different modes depending on the input vibration, the vibration suppression effect by both the axial vibration control devices acts synergistically to generate the main rubber elasticity. An effective anti-surging effect can be exerted on the body 16.

  Next, an automobile engine mount 50 according to a second embodiment of the present invention is shown in FIGS. In this embodiment, as compared with the engine mount (10) of the first embodiment described above, another configuration example of the end vibration damping device is shown, and the structure of the engine mount body is the first. Therefore, members and parts having the same structure as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment. Therefore, detailed description thereof will be omitted.

  That is, the engine mount 50 of this embodiment includes a support rod 52 that is substantially the same as the support rod 32 of the first embodiment. As in the first embodiment, the support rod 52 penetrates the substantially central portion in the free length direction of each elastic connecting portion 24 constituting the main rubber elastic body 16 in the axial direction. It is vulcanized and bonded.

  Further, hollow housings 54 are integrally formed at both ends in the axial direction of the support rod 52 extending through the main rubber elastic body 16 in the axial direction. The hollow housing 54 may be made of a hard synthetic resin material, but is preferably made of a metal material having high rigidity such as steel, like the support rod 52.

  The hollow housing 54 has a space that is substantially sealed inside. Specifically, the hollow housing 54 includes a cylindrical peripheral wall portion 56 and a pair of disc-shaped lid wall portions 58 and 58, and openings on both sides in the axial direction of the peripheral wall portion 56 are respectively lid wall portions. By covering with 58, 58, a substantially circular hollow space is formed inside as an end accommodating space 60. In addition, it is desirable that the end portion accommodating space 60 has a substantially sealed structure to the extent that water can be prevented from entering from the outside.

  The hollow housing 54 is positioned on the same central axis on both sides in the axial direction of the support rod 52, and the axial front end surface of the support rod 52 is located at the center of one lid wall portion 58 in the axial direction. It is superimposed and fixed to welding or the like. Thereby, the hollow housings 54 and 54 are integrally formed in the axial direction both ends of the support rod 52 with a substantially symmetrical structure in the axial direction.

  Further, a built-in float mass 62 as a separate end mass member is accommodated and assembled in the end accommodating space 60 of each hollow housing 54. The built-in float mass 62 may be entirely formed of a rubber elastic body, a synthetic resin material, or the like, but is desirably formed of a metal material in order to efficiently obtain a mass with a small volume. The built-in float mass 62 has an outer peripheral surface shape that is slightly smaller than the inner peripheral surface shape of the end accommodating space 60. That is, it is substantially similar to the end portion accommodating space 60 and has a slightly smaller shape.

  The built-in float mass 62 is formed with a contact rubber layer 64 made of a thin rubber film so as to cover the entire outer peripheral surface thereof. Note that the thickness of the contact rubber layer 64 is substantially constant throughout, and the shape of the outer peripheral surface of the contact rubber layer 64 is also the shape of the inner peripheral surface of the end housing space 60 of the hollow housing 54. It is a little smaller than.

  That is, in a state where the built-in float mass 62 is positioned in the center without considering the gravitational action in the hollow housing 54, it is between the surface of the contact rubber layer 64 in the built-in float mass 62 and the inner surface of the hollow housing 54. Is formed with a gap around the entire periphery of the built-in float mass 62.

  In other words, as shown in the figure, the built-in float mass 62 is positioned at the lower end in the hollow housing 54 by gravity and supported while being placed on the bottom of the peripheral wall of the hollow housing 54. ing. Under such a condition, the cylindrical outer peripheral surface of the built-in float mass 62 is in contact with the cylindrical inner peripheral surface of the hollow housing 54 at the vertical lower end portion, while the attached upper end portion of the built-in float mass 62 is attached to the vertical upper end portion. The surface of the rubber contact layer 64 is separated from the inner surface of the top of the peripheral wall of the hollow housing 54 by a predetermined distance of 2δ.

  The size of this gap: 2δ is set to the same value as the gap size: 2δ between the contact rubber layer 36 of the annular float mass 38 and the axially opposed surface of the annular float mass 38 in the first embodiment. It is desirable that Further, in the built-in float mass 62, the contact rubber layer 64 that constitutes the contact surface that abuts against the hollow housing 54 of the support rod 52 is the same as the contact rubber layer 36 of the annular float mass 38 in the first embodiment. It is desirable to set the same hardness.

  That is, in the engine mount 50 of the present embodiment having the above-described structure, the elastic deformation of the elastic connecting portions 24 and 24 of the main rubber elastic body 16 is applied to the support rod 52 when vibration is input in the mounted state. When the built-in float mass 62 in the hollow housing 54 is vibrated as a vibration force, the built-in float mass 62 jumps and is displaced in the hollow housing 54.

  Therefore, similarly to the engine mount 10 of the first embodiment, the main rubber elastic body 16 (the pair of elastic connecting portions 24, 24) is based on repeated contact (contact) of the built-in float mass 62 with the hollow housing 54. The damping effect or the amplitude suppression effect with respect to the elastic repeated displacement (vibration displacement) of 24) is exhibited.

  Therefore, in the engine mount 50 of this embodiment, various effects of the damping contact type end vibration damping device can be exhibited as in the case of the engine mount 10 of the first embodiment. The decrease in the vibration proof characteristic due to the 16 surging phenomenon can be effectively avoided.

  In particular, in the present embodiment, the built-in float masses 62 and 62 that constitute the damping contact-type end vibration damping device are disposed outside the main rubber elastic body 16, and thus are the same as in the first embodiment. In addition, the mass of the independent float mass 38 can be set large while sufficiently securing the volume of the main rubber elastic body 16. In addition, in the present embodiment, the contact surface of the built-in float mass 62 and the support rod 52 is formed in the end accommodating space 60 of the hollow housing 54 formed in the support rod 52. The contact surface is substantially cut off from the external space, and foreign matter can be prevented from entering the contact surface. Therefore, problems such as a decrease in the vibration damping effect caused by foreign matter biting into the contact surface can be prevented, and the desired surging reduction effect of the main rubber elastic body 16 can be obtained more stably. It becomes.

  Next, an engine mount 70 for an automobile as a third embodiment of the present invention is shown in FIGS. In the present embodiment, members and parts having the same structure as the engine mount (50) of the second embodiment are denoted by the same reference numerals as those of the second embodiment. It is attached. In addition, the engine mount 70 of the present embodiment has an outer cylindrical metal piece 14 having an irregular cylindrical shape in consideration of a mount mounting structure or the like in an automobile body, and protrudes from the inner peripheral surface of the outer cylindrical metal piece 14. The upper stopper portion 28 is also divided into two on both sides in the circumferential direction. However, these are not major features of the present invention and are within the scope of appropriate design changes, and thus detailed description thereof is omitted.

  That is, one of the features of the engine mount 70 of the present embodiment is a pair of damping contact type end dampings provided on both sides in the axial direction as compared with the engine mount (50) of the second embodiment. In addition to the device, a damping contact type vibration damping device (central vibration damping device) is also provided in the central portion in the axial direction.

  Specifically, the elastic connecting portions 24, 24 constituting the main rubber elastic body 16 are provided with support rods 72, 24 in the same manner as the support rods (32, 32) of the engine mount (50) of the second embodiment. 72 is attached. Each support rod 72 is disposed and fixed so as to penetrate the intermediate portion in the free length direction of the elastic connecting portion 24 in the axial direction, as in the second embodiment. In addition, as for the material of each support rod 72, it is desirable to form with rigid materials, such as a metal like the thing of 2nd embodiment.

Here, such a support rod 72 has a middle empty cylindrical shape and is a tubular structure extending in the axial direction with a constant inside and outside diameter. Further, one end wall portion 58 of the hollow housing 54 is overlapped and fixed to both ends in the axial direction of the support rod 72 by welding or the like. Thereby, the opening of the axial direction both sides of the support rod 72 is covered with the hollow housings 54 and 54, and the center housing of a hollow structure is comprised. That is, a central housing space 74 extending in the axial direction with a circular cross section is formed in the central housing in the axially intermediate portion embedded in the elastic coupling portion 24. It is desirable that the central accommodation space 74 has a substantially sealed structure to the extent that water can be prevented from entering from the outside.

  Further, a central built-in float mass 76 as a central separate mass member is accommodated and assembled in the central accommodating space 74. The central built-in float mass 76 is desirably formed of a metal material, like the built-in float mass (62) of the second embodiment. The central built-in float mass 76 has an outer peripheral surface shape that is slightly smaller than the inner peripheral surface shape of the central housing space 74. That is, it has a slightly smaller shape that is substantially similar to the central accommodation space 74.

  In addition, a contact rubber layer 78 is formed on the central built-in float mass 76 from a thin rubber film so as to cover substantially the entire outer peripheral surface thereof. Note that the thickness of the contact rubber layer 78 is substantially constant throughout, and the shape of the outer peripheral surface of the contact rubber layer 78 is slightly smaller than the shape of the inner peripheral surface of the central housing space 74. Has been.

  That is, in the same manner as the end damping device in the second embodiment, the central built-in float mass 76 is positioned in the center accommodation space 74 without considering the gravitational action. A gap is formed between the surface of the contact rubber layer 78 in 76 and the inner surface of the central housing space 74 around the entire center built-in float mass 76.

  In other words, as shown in FIG. 9, the central built-in float mass 76 is positioned at the lower end in the central receiving space 74 by gravity and placed on the bottom of the peripheral wall of the central receiving space 74. It is to be supported in the state. Under such a state, the cylindrical outer peripheral surface of the central built-in float mass 76 is in a per-line state with respect to the inner peripheral surface of the cylindrical wall portion of the support rod 72 constituting the peripheral wall portion of the central accommodating space 74 at the vertical lower end portion. In contact. On the other hand, at the vertical upper end of the central built-in float mass 76, the surface of the abutting rubber layer 78 is against the inner peripheral surface of the cylindrical wall portion of the support rod 72 that forms the top of the peripheral wall of the central accommodation space 74. , A gap of a predetermined distance: 2δ.

  The size of the gap: 2δ and the material of the contact rubber layer 78 are desirably set in the same manner as in the end vibration damping device in the second embodiment.

  In the engine mount 70 of the present embodiment having the above-described structure, the elastic deformation of the elastic connecting portions 24 and 24 of the main rubber elastic body 16 is applied to the support rod 72 at the time of vibration input in the mounted state. As a pair of damping contact type end damping devices provided at both ends of the support rod 72 in the axial direction, as well as a damping contact type provided at the central portion of the support rod 72 in the axial direction. A central damping device also works.

  That is, when the support rod 72 is displaced in the direction perpendicular to the axis, an excitation force is exerted on the central built-in float mass 76 in the central accommodation space 74 in which the peripheral wall portion is constituted by the support rod 72, The central built-in float mass 76 is jumped and displaced in the central accommodation space 74.

  And, by repeatedly hitting (contacting) the central built-in float mass 76 with respect to the support rod 72, the main body as well as the end vibration control devices at both ends having substantially the same structure as the second embodiment. The rubber elastic body 16 (the pair of elastic connecting portions 24, 24) exhibits a damping effect or an amplitude suppressing effect on the elastic repeated displacement (vibration displacement), and is effective for the surging phenomenon of the main rubber elastic body 16. The suppression effect is demonstrated.

  Therefore, the engine mount 70 of the present embodiment includes one central vibration damping device in addition to the pair of end vibration damping devices, and the vibration damping effect by these three damping contact type vibration damping devices, that is, The effect of suppressing the surging phenomenon is exerted on the main rubber elastic body 16. Therefore, it is possible to set a large mass as a whole without setting the size of each damping device (end damping device and central damping device) so large. Thereby, for example, even when the space of the arrangement area of the hollow housings 54, 54 on both sides in the axial direction of the main rubber elastic body 16 is limited, the volume of the main rubber elastic body is not reduced so much to a total of three. As a result of the cooperative action of the damping contact-type vibration damping device, it is possible to secure the entire mass mass and achieve the effective surging phenomenon suppression effect as a whole.

  As mentioned above, although embodiment of this invention has been explained in full detail, these are illustrations to the last and this invention is not limitedly interpreted by the specific description of this embodiment.

  For example, in the engine mount 10 of the first embodiment, a contact rubber layer may be formed on the inner peripheral surface of the annular float mass 38 in addition to or instead of the outer peripheral surface of the support rod 32. good. In particular, in this embodiment, the contact surfaces of the support rod 32 and the annular float mass 38 are both cylindrical, and rotational displacement around the central axis of the annular float mass 38 is allowed. Therefore, by forming the contact rubber layer on the annular float mass 38 side, the contact portion (contact portion) on the contact surface formed by the contact rubber layer changes in the circumferential direction. It is also possible to improve the durability of the entire contact rubber layer.

  Similarly, in the vibration damping device in the engine mounts 50 and 70 of the second embodiment and the third embodiment, in addition to or instead of the surface of the built-in float masses 62 and 76, the built-in float masses 62 and 76 are used. A contact rubber layer may be formed on the inner peripheral surface of the hollow housing 54 or the support rod 72 constituting the contact surface.

  In particular, in the engine mount 70 of the third embodiment, when an abutting rubber layer is deposited on the inner peripheral surface of the support rod 72, Japanese Patent Application Laid-Open No. 2002-227921 (patent document) As described in 1), the contact rubber layer is integrally formed with the main rubber elastic body by rotating the rubber material to the inner peripheral surface of the hollow support rod 72 during the vulcanization molding of the main rubber elastic body 16. It is also possible to do.

  Furthermore, the specific shape of the main rubber elastic body is not particularly limited, and various shapes are employed depending on the required spring characteristics and the like. For example, various structures such as a structure in which only one of the upper and lower slits 20 and 22 is formed, a structure in which such a slit is not formed, a structure in which the axial thickness is partially different in the circumferential direction, etc. The structure or shape of the main rubber elastic body can be adopted.

  In addition, a part of the wall portion is constituted by the main rubber elastic body, so that a fluid chamber is formed between the radially opposing surfaces of the inner and outer cylindrical fittings and in which an incompressible fluid is enclosed, and at the time of vibration input The present invention can also be applied to a conventionally well-known fluid-filled cylindrical vibration isolator that obtains an anti-vibration effect by utilizing a fluid action such as a resonance action of an incompressible fluid that is induced. It is.

  And according to the difference in the shape and structure of such a main rubber elastic body, the part that dominates the surging phenomenon is different, so the arrangement position of the support rod member in the main rubber elastic body is also different. These are set at different positions. In this case, the number of support rod members is not limited to two as illustrated, and one or three or more may be provided. When multiple support rod members are provided, the support rod members are arranged apart from each other in the circumferential direction of the main rubber elastic body, and are arranged apart from each other in the free length direction (perpendicular to the axis) of the main rubber elastic body. For example, it is possible to obtain an effective suppression effect against a surging phenomenon in, for example, a second-order or higher vibration mode. Further, the shape of the support rod member is not limited to the one having the cylindrical outer peripheral surface as illustrated, and an irregular outer peripheral surface shape or a plate-shaped support rod member may be adopted, or the outer peripheral surface shape may be adopted. May be different in the axial direction.

  Further, the number of separate mass members constituting the damping contact type vibration damping device by being assembled to the support rod member is not particularly limited. For example, a single mass damping device may be configured by attaching a separate mass member only to one end portion in the axial direction of the support rod member. Further, for example, two or more annular float masses 38 and built-in float masses 62 may be attached to the protruding end portions 34 and the end portion accommodating spaces 60 of the support rods 32 and 52 in the above-described embodiment. Of course, two or more central built-in float masses 76 may be attached to the central accommodation space 74 in the third embodiment.

  Further, the specific shapes of the support rod member and the separate mass member constituting the end vibration damping device are not particularly limited. For example, in each of the above embodiments, the contact surface between the support rod member and the separate mass member is a cylindrical surface around the central axis, but may be a polygonal shape such as a rectangle or an elliptical shape. Also, it is possible to accommodate and assemble a spherical separate mass member to the support rod member having a hollow housing structure.

  Further, when providing a plurality of support rod members as in the above-described embodiment, the separate mass members at the end of the damping contact type end damping device constituted by each support rod are connected to each other or rigidly connected. You may unite. Specifically, for example, in the first embodiment, two annular float masses 38 attached by extrapolation to projecting ends 34, 34 projecting on the same side in the axial direction in the two support rods 32, 32, It is also possible to integrate 38 by rigidly connecting them by connecting portions that are integrally connected to each other in the circumferential direction. As a result, the mass of the entire mass can be secured more advantageously, and the jumping displacement of the two annular float masses 38, 38 can be stabilized.

  Alternatively, as shown in the third embodiment, a support rod 72 having a tubular structure is adopted, and the hollow interior of the support rod 72 is opened in the hollow housings 54 and 54 on both axial sides. Then, a pair of built-in float masses 62, 62 disposed in the hollow housings 54, 54 on both axial sides are connected to each other in the axial direction by a rigid rod inserted into the hollow inside of the support rod 72, and integrated. You may make it. By adopting such built-in integrated built-in float masses 62, 62, the overall mass mass can be secured more advantageously, and the jump displacement of the two annular float masses 38, 38 can be stabilized. It becomes possible. In this case, since the rigid rod does not contact the hollow inner surface of the support rod 72 in principle, the central damping device is not configured, and the configuration substantially corresponds to the second embodiment. Can be grasped.

  In addition, the support rod member has a basic function of exerting a damping action on the main rubber elastic body by the damping contact type end damping device provided on the outer side in the axial direction of the main rubber elastic body. Therefore, various modes that can satisfy such a function can be freely adopted. For example, in the first embodiment, a through hole in a direction perpendicular to the axis is formed at an appropriate position on the shaft of the support rod 32. It is also possible to increase the adhesion area of the support rod 32 and the main rubber elastic body 16 and further increase the volume of the main rubber elastic body 16. Alternatively, in the second embodiment, a plurality of small-diameter rods may be protruded from the hollow housing 54, and the plurality of small-diameter rods may be passed through the main rubber elastic body 16 to constitute the support rod member.

  Furthermore, in the above-described embodiments, the support rod member and the separate mass member are continuously positioned over the entire circumferential direction between the contact surfaces of the both members while being positioned on the same central axis. The gap: δ (δ> 0) is formed, but when the gap: δ (δ> 0) is applied when the vibration to be damped is input, the substantial contact is made between the contact surfaces. Should just occur. Therefore, for example, as shown in FIG. 10A, when no vibration load is applied, the contact surface between the support rod member 80 and the separate mass member 82 is either one of the members ( In the example shown in FIG. 10, even if the contact rubber layer 84 is attached to the contact surface on the support rod member 80 side and the gap is substantially zero, FIG. As shown, when the vibration to be damped is input (in the example in the figure, the vertical excitation force in the figure is input), the separate mass member 82 is relatively displaced with respect to the support rod member 80. It is only necessary that a gap: δ (δ> 0) be generated between the contact surfaces based on the elastic deformation of the contact rubber layer 84 when the contact rubber layer 84 is swaged. In the illustrated example, a space is secured for the contact rubber layer 84 to be elastically deformed in the axial direction (direction perpendicular to the paper surface) to escape.

  In addition, although not enumerated one by one, the present invention can be carried out in an embodiment to which various changes, modifications, improvements, etc. 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.

It is a front view which shows the engine mount for motor vehicles as 1st embodiment of this invention. It is II-II sectional drawing in FIG. FIG. 2 is a perspective view of the engine mount shown in FIG. 1. FIG. 2 is an enlarged explanatory view of a transverse section of an end vibration damping device in the engine mount shown in FIG. 1. It is a front view which shows the principal part of the engine mount for motor vehicles as 2nd embodiment of this invention. It is VI-VI sectional drawing in FIG. It is a front view which shows the engine mount for motor vehicles as 3rd embodiment of this invention. It is VIII-VIII sectional drawing in FIG. FIG. 2 is an enlarged explanatory view of a transverse section of a central vibration damping device in the engine mount shown in FIG. 1. For example, it is a cross-sectional view showing another example of the end vibration damping device that can be employed in the engine mount of the first embodiment shown in FIG. 1, wherein (a) shows the stationary state, (B) shows the input state of the vibration load.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine mount 12 Inner cylinder metal fitting 14 Outer cylinder metal fitting 16 Main body rubber elastic body 24 Elastic connection part 32 Support rod 34 Projection end part 36 Contact rubber layer 38 Annular float mass

Claims (9)

In the cylindrical vibration isolator in which the outer cylinder member is disposed apart from the outer peripheral side of the inner shaft member, and the axially perpendicular facing surfaces of the inner shaft member and the outer cylinder member are connected by a main rubber elastic body.
A hard support rod member extending in the axial direction through the main rubber elastic body is provided at an intermediate portion between opposed surfaces of the inner shaft member and the outer cylinder member in the direction perpendicular to the axis, and the support is provided. while against the outer periphery of the rod member to the rubber elastic body allowed to wear vulcanization, the axial end portion of the supporting rod member is projected outwardly from the rubber elastic body, with respect to such axially protruding portion The separate end mass member formed independently from the support rod member is assembled so as to be relatively displaceable in the direction perpendicular to the axis, and at least one of the mutual contact surfaces of the support rod member and the separate end mass member is attached to the support rod member. By forming the contact rubber made of rubber elastic material, the support rod member and the separate mass member at the end portion are substantially separated from the contact state via the contact rubber when the vibration is input in the direction perpendicular to the axis. The end by repeating Cylindrical vibration damping device body mass member is characterized by being configured to end the damping device damping the contact type striking repeatedly against the support rod member.
  The contact-type vibration damping device is provided with the axially protruding portions at both axial end portions of the support rod member, and the end-part separate mass members are assembled to both the axially protruding portions, respectively. The cylindrical vibration isolator according to claim 1, wherein the two are symmetrically formed at both ends in the axial direction.   By forming the end separate mass member into an annular shape and assembling the annular end separate mass member with respect to the axially protruding portion of the support rod member in an extrapolated state, the outer peripheral surface of the support rod member The cylindrical vibration isolator according to claim 1 or 2, wherein the contact surface is constituted by an inner peripheral surface of the annular separate mass member. A hollow housing is formed at the axially projecting portion of the support rod member, and the separate mass member at the end is accommodated in the housing and assembled, whereby the inner peripheral surface of the housing and the separate end are separated. The cylindrical vibration isolator according to claim 1 or 2 , wherein the contact surface is constituted by an outer peripheral surface of a body mass member.   Both the support rod member and the separate end mass member are formed of a metal material, and a rubber elastic body layer is applied to at least one of the axially protruding portion of the support rod member and the separate end mass member. The cylindrical vibration isolator according to any one of claims 1 to 4, wherein the contact rubber is constituted by the rubber elastic body layer.   A central housing is formed by forming a hollow intermediate structure in the axial direction of the support rod member positioned inside the main rubber elastic body, and a center formed independently from the support rod member in the central housing. The separate mass member is assembled so as to be relatively displaceable in the direction perpendicular to the axis, and at least one of the mutual contact surfaces of the support rod member and the central separate mass member is formed of a contact rubber made of a rubber elastic material. When the vibration is applied in the direction perpendicular to the axis, the support rod member and the central separate mass member repeat a contact state and a substantially separated state via the corresponding contact rubber, so that the central separate mass member becomes the support rod. The cylindrical vibration isolator according to any one of claims 1 to 5, comprising a damping contact type central vibration damping device that repeatedly strikes a member.   In the main rubber elastic body, at least one hollow hole extending in the axial direction is formed between the opposed surfaces of the inner shaft member and the outer cylindrical member in the direction perpendicular to the axis. The cylindrical vibration isolator according to any one of claims 1 to 6, wherein a pair of the support rod members are provided so as to be positioned on both sides in the circumferential direction with the lightening hole interposed therebetween.   With the support rod member and the separate mass member at the end positioned on the same central axis, the entire circumference in the circumferential direction is between the contact surfaces of the support rod member and the separate mass member at the end. A continuous gap is formed so that the separate mass member at the end jumps away from the support rod member completely in the direction perpendicular to the axis and repeatedly strikes the support rod member. The cylindrical vibration isolator according to any one of 7. Under the state where the support rod member and the separate mass member at the end are positioned on the same central axis, the contact surface between the support rod member and the separate mass member at the end extends over the entire circumference. Substantially free of clearance, and a gap is generated between the contact surfaces of the support rod member and the separate mass member on the basis of elastic deformation of the contact rubber when vibration is input, The cylindrical vibration isolator according to any one of claims 1 to 7, wherein the separate mass member at the end is repeatedly hit against the support rod member in a direction perpendicular to the axis.

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