Vibration damping device

Abstract

Vibration damping device (10), comprising: a first (18) and a second fastening element (20) connected to each other by an elastic rubber main body (22); and a first (14) and a second stop part (16) which are arranged opposite each other in a direction of the relative displacement of the first (18) and the second fastening element (20) while they abut each other via a rubber buffer layer (80), wherein the vibration damping device (10) is characterized in that: a concave groove (46) is provided on one of the other opposite surfaces of at least one of the first (14) and second stop part (16); an inner projection (96) on the rubber buffer layer (80) covered by the opposite surface is designed such that it is inserted into the concave groove (46), and both sides of the inner projection (96) are free end surfaces in the longitudinal direction of the concave groove (46); an outer projection (98) on a structural part of the inner projection (96) on the rubber buffer layer (80) is formed such that it projects outwards from the concave groove (46), wherein a dimension of the outer projection (98) in the transverse direction of the concave groove (46) is smaller than that of the inner projection (96); and a displacement control section with a lower surface height than that of the distal end surface of the outer projection (98) on the rubber buffer layer (80) is formed, which covers an area of ​​the opposite surface that is located transversely to both sides of the concave groove (46).

Description

TECHNICAL FIELD

[0001] The application relates to a vibration damping device for use in a motor vehicle engine mount and the like. BACKGROUND

[0002] Typically, a vibration damping device is known as a type of vibration damping device that is to be arranged between elements constituting a vibration transmission system and that comprises a first fastening element and a second fastening element connected by an elastic rubber main body. Engine mounts, body mounts, suspension supports, or vibration damping bushings for motor vehicles are examples of such devices.

[0003] In such a vibration damping device, a stopper mechanism is used to limit the relative displacement between the first fastening member and the second fastening member, thereby restricting the amount of elastic deformation of the elastic rubber main body and the relative displacement between the members upon excessive load input. Such a stopper mechanism is essentially configured by providing first and second stopper members facing each other in the direction of relative displacement between the first and second fastening members so as to abut against each other via a rubber buffer layer.

[0004] Meanwhile, the stop mechanism must have both a buffer function to mitigate the shock at the time of contact between the first and second stop members and a displacement limiting function that reliably regulates the relative displacement between the first and second stop members. Regarding the former, it is effective to design the rubber buffer with a larger volume to allow it to exert soft spring characteristics. Thus, it has been conventionally treated by thickening the rubber buffer layer by creating bulges and concavities, and by selecting a sufficiently low rubber hardness.

[0005] However, such treatment had a problem in that the reliability of the displacement limiting function of the rubber buffer was reduced, making it difficult to provide both functions simultaneously. Furthermore, since the size of the adjustable space between the facing surfaces of the first and second stopper parts where the rubber buffer is arranged is limited by the relationship with other elements and the like, it was sometimes inherently difficult to adjust the thickness of the rubber buffer layer.

[0006] To address this type of problem, the applicant previously proposed a structure in Japanese Unexamined Patent Publication No. JP-A-2005-106138 (Patent Document 1) in which the thickness of the rubber buffer layer is increased by providing a concave recess at a position facing the stopper part. While such a structure is effective in substantially setting the thickness of the rubber buffer layer sufficiently large while maintaining its durability when the rubber buffer layer has a Poisson's ratio of approximately 1 / 2, its reduced spring constant requires an improvement in the buffer function in some cases. BACKGROUND PATENT DOCUMENT

[0007] Patent document 1: JP 2005- 106 138 A

[0008] DE 11 2011 101 765 B4 discloses a vibration damping device in which first and second fastening elements and an elastic rubber main body are joined together in a non-adhesive manner, so that the occurrence of noise or a reduction in durability due to corrosion can be prevented. A first fastening element, provided with a coupling portion, and a second fastening element, to which a gate-shaped element is attached, are attached to both sides of an elastic rubber main body in a non-adhesive manner.

[0009] US 2010 / 0 327 502 A1 relates to a vibration-damping support device which is provided with a rubber mount, a support element which carries the rubber mount, and stoppers.

[0010] DE 43 22 126 A1 relates to an elastic bearing, in particular for supporting drive units in motor vehicles, with a support arm projecting laterally from the drive unit, which is supported on a rigid abutment via elastomer bodies. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0011] The invention has been developed in view of the above-described aspects as background, and it is an object of the invention to provide a vibration damping device having a novel structure in which both a good buffer function and a good displacement limiting function are achieved simultaneously and each of these functions can be stably performed. MEANS TO SOLVE THE PROBLEM

[0012] A first aspect of the invention for solving the problem provides a vibration damping device according to independent claim 1. Preferred embodiments are defined in the dependent claims.

[0013] In the vibration damping device having the structure of the present aspect, by employing a combination of "the concave groove in the stopper part" and "the specific inner protrusion, outer protrusion, and displacement regulating portion in the rubber buffer layer," two main functions of "buffer function" and "displacement limiting function" could be assigned a role each to achieve both effects simultaneously in the stopper mechanism by which a relative displacement between the first and second fastening members is regulated in a buffered manner.

[0014] Thus, regarding the "buffer function", an excellent buffer effect could be achieved due to the small spring action within a limited space between the opposing surfaces of the first and second stopper parts by "effectively ensuring the volume or thickness of the rubber buffer layer by the inner projection engaging with the concave groove of the stopper portion and the outer projection protruding from the concave groove", and "ensuring the degree of freedom of elastic deformation by using the end surfaces on both sides of the inner projection in the longitudinal direction of the concave groove as the free surface".

[0015] Meanwhile, as for the "displacement limiting function", when the amount of relative displacement between the first and second fastening members becomes larger so as to more than displace the shock absorbing action of the above-described outer protrusion exerting the buffer function, a reliable displacement limiting function could be achieved starting from the abutment action between the first and second abutment members via the displacement regulating portion by providing a thin-walled portion having a displacement limiting function on the rubber buffer layer covering the area outside the concave groove of the abutment member.

[0016] Furthermore, the vibration damping device of the present aspect also has a design advantage in that both the buffering effect and the displacement limiting effect can be efficiently adjusted by dividing the functions between the inner and outer protrusions, which mainly provide buffering functions, and the rubber buffer layer, which mainly provides the displacement limiting function, and by modifying the size, shape, and the like of both the inner and outer protrusions and the rubber buffer layer according to requirements. Furthermore, impact forces exerted on the outer protrusion due to abutment against the stopper part can be more effectively transmitted from the outer protrusion to the inner protrusion, so that the buffering effect can be more effectively exerted based on the elastic deformation of both the outer protrusion and the inner protrusion.

[0017] A second aspect of the invention provides the vibration damping device according to the first aspect, wherein the rubber buffer layer is covered with the at least one of the first and second stopper parts at least on the structural part of the inner projection in a non-adhesive manner.

[0018] According to the present aspect, deformation preventing forces of the inner protrusion caused by the stopper part are reduced to reduce the spring action of the inner protrusion and improve the durability thereof, which can result in the improved buffer function of the outer protrusion based on its stopper action.

[0019] A third aspect of the invention provides the vibration damping device according to the first or second aspect, wherein the inner projection abuts against an inner surface of the concave groove.

[0020] According to this aspect, when the buffer function based on the abutment of the outer protrusion is effective, a noticeable noise or impact caused by the inner protrusion hitting the inner surface of the concave groove can be minimized, while any noticeable linearity deviation of the spring characteristic caused by the inner protrusion hitting the inner surface of the concave groove after the increase in contact load can be avoided.

[0021] A fourth aspect of the invention provides the vibration damping device according to any one of the first to third aspects, wherein the outer projection includes a plurality of linear ribs extending in the longitudinal direction of the concave groove.

[0022] According to this aspect, it becomes possible to ensure a large free surface and, at the same time, a large rubber volume to the outer projection, thus enabling further improvement of the buffering effect exerted in cooperation between the outer projection and the inner projection.

[0023] A fifth aspect of the invention provides the vibration damping device according to any one of the first to fourth aspects, wherein the outer protrusion is formed with a smaller rubber volume than that of the inner protrusion.

[0024] According to this aspect, by restricting the rubber volume of the outer protrusion, the initial spring characteristic exhibited from the elastic deformation of the outer protrusion at the time of abutment against the stopper part can be soft enough, enabling the improvement of the initial buffer effect.

[0025] A sixth aspect of the invention provides the vibration damping device according to any one of the first to fifth aspects, wherein the outer projection is wedge-shaped.

[0026] According to this aspect, since the outer protrusion itself has a non-linear slowly increasing spring characteristic, it becomes possible to appropriately adjust the buffer effect by utilizing the changes in the spring characteristic due to the transition from the elastic deformation of the outer protrusion to the elastic deformation of the inner protrusion and the change in the spring characteristic due to the increase in the amount of elastic deformation of the outer protrusion itself.

[0027] A seventh aspect of the invention provides the vibration damping device according to any one of the first to sixth aspects, wherein the displacement regulating part is formed to extend with a nearly constant thickness on the opposite surface.

[0028] According to this aspect, by making the stopper part abut against almost the entire surface of the displacement regulating part, which expands with a nearly constant thickness, a localized concentration of stress and strain of the rubber buffer layer can be prevented to improve its durability.

[0029] An eighth aspect of the invention provides the vibration damping device according to any one of the first to seventh aspects, wherein the concave groove extends continuously across both ends of the opposite surface of the at least one of the first and second stopper parts, and both longitudinal sides of the concave groove are open at the respective ends of the opposite surface.

[0030] According to this aspect, it becomes possible to effectively ensure the rubber volume of the inner protrusion while maintaining the free surface of the inner protrusion on both sides of the concave groove in the longitudinal direction.

[0031] A ninth aspect of the invention provides the vibration damping device according to any one of the first to eighth aspects, wherein an inside holder is attached to the first fixing member, while an outside holder is attached to the second fixing member so as to overlap an outside of the inside holder with a gap, and the first and second stopper parts are composed of the inside and outside holders, respectively, while the inside holder is provided with the concave groove and the rubber buffer layer.

[0032] Since the first and second stopper parts are formed by the inside and outside holders provided separately from the first and second fastening members, respectively, the degree of freedom in designing the shape of the stopper part can be increased, which makes it possible to keep the contact area of ​​the stopper part large enough and, for example, to facilitate the attachment of the rubber buffer layer on the stopper part.

[0033] A tenth aspect of the invention provides the vibration damping device according to any one of the first to ninth aspects, wherein a gate-shaped member is provided on the outside bracket so as to cover an outside of the first fixing member, while an insertion portion is provided on the inside bracket so as to be insertable into the gate-shaped member of the outside bracket from one side and fixed to the first fixing member, and a rubber buffer member constituting the rubber buffer layer is attached to the inside bracket in a state of covering the insertion portion.

[0034] According to this aspect, both side surfaces of the inner holder are arranged transversely opposite the leg portions of the gate-shaped element of the outer holder to create a pair of stop surfaces in an efficient, space-saving manner. Furthermore, the rubber buffer element covering the inner holder forms the rubber buffer layer, thus covering the pair of stop surfaces, which facilitates the provision of the rubber buffer layer on the inner holder. EFFECT OF THE INVENTION

[0035] In the vibration damping device having the structure according to the present invention, an excellent buffering effect is exhibited on the stopper mechanism by the inner protrusion with its two sides configured as free surfaces in the concave groove of the stopper portion and by the outer protrusion protruding from the concave groove, while a reliable displacement limiting effect can be exerted by the displacement regulating portion covering the opposing surface of the stopper part remote from the concave groove. This makes both the buffering function and the displacement limiting function highly practical at the same time for the stopper mechanism in which the first and second stopper parts abut each other via the rubber buffer layer. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Fig. 1 is a longitudinal section of a vibration damping device as a first embodiment of the present invention, which is a section taken along the line 1-1 of Fig. 3 represents. Fig. 2 is another longitudinal section of the Fig. 1, which is a section along the line 2-2 of Fig. 3 represents. Fig. 3 is a plan view of the Fig. Vibration damping device shown in Figure 1. Fig. 4 is a front view of the Fig. Vibration damping device shown in Figure 1. Fig. 5 is a right side view of the Fig. Vibration damping device shown in Figure 1. Fig. 6 is a rear view of the Fig. Vibration damping device shown in Figure 1. Fig. 7 is a perspective view of an inside holder of the Fig. Vibration damping device shown in Figure 1. Fig. 8 is a plan view of the Fig. 7 shown inside holder. Fig. 9 is a bottom view of the Fig. 7 shown inside holder. Fig. 10 is a perspective view of a rubber buffer element of the Fig. Vibration damping device shown in Figure 1. Fig. 11 is a plan view of the Fig. 10 shown rubber buffer element. Fig. 12 is a bottom view of the Fig. 10 shown rubber buffer element. Fig. 13 is a left side view of the Fig. 10 shown rubber buffer element. Fig. 14 is a cross section along line 14-14 of Fig. 11. Fig. 15 is a rear view of the Fig. 10 shown rubber buffer element. Fig. 16 is an enlarged cross-sectional view of a main part around the abutment between the inside holder and the rubber buffer member in the present embodiment. Fig. 17 is a perspective view of a rubber buffer member of a vibration damping device as a second embodiment of the present invention. Fig. 18 is a bottom view of the Fig. 17 shown rubber buffer element. Fig. 19 is an enlarged cross-sectional view of a main part around the abutment between the inside holder and the rubber buffer member in the present embodiment. EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0036] Embodiments of the invention will be described below with reference to the drawings.

[0037] First, the Fig. 1 to 6 show a motor vehicle engine mount 10 as a first embodiment of the vibration damping device having the structure according to the present invention. The engine mount 10 has a structure in which an inside bracket 14 and an outside bracket 16 are attached to a mounting body 12. Then, a first fastening element 18 is mounted to the engine via the inside bracket 14, while a second fastening element 20 is mounted to a vehicle body via the outside bracket, whereby the engine is supported by the vehicle body in a vibration-damping manner. In the following descriptions, "up-down direction" refers to the up-down direction in Fig. 1, which approximately corresponds to the vertical direction of attachment to the motor vehicle.

[0038] Described in detail, the fastening body 12 has a structure in which the first fastening element 18 and the second fastening element 20 are connected to each other by an elastic rubber main body 22.

[0039] Described further in detail, the first fastening member 18 is a high-rigidity member approximately in the shape of a circular block made of a metal material such as iron, aluminum alloy, or the like. Further, a bolt hole 24 extending in an up-down direction and open to the upper surface is formed at the radial center of the first fastening member 18. Furthermore, a flange 26 in an annular shape is integrally formed at the upper end of the first fastening member 18. Then, the upper end surface of the first fastening member 18 is sandwiched by the upper surface of the flange 26 to form a flat outer end surface 28 having a large diameter extending in the direction perpendicular to the axis of the fastener body.

[0040] Meanwhile, the second fastening member 20 is approximately shaped like a thin, circular cylinder with a large diameter and is made of a similar material to the first fastening member 18, which has high rigidity. The lower end of the second fastening member 20 is formed into an annular bottom portion 30 that is bent toward the inner circumference.

[0041] Then, the first fastening member 18 and the second fastening member 20 are arranged such that the first fastening member 18 is arranged above the second fastening member 20 at a distance therefrom and is elastically connected thereto by the elastic rubber main body 22.

[0042] The elastic rubber main body 22 is approximately in the shape of a thick truncated cone with a large diameter, and a central recess 32 is formed on the end surface of its larger diameter side so as to be open downward. Also, the first fastening member 18 is inserted into the end surface of the smaller diameter side of the elastic rubber main body 22 and bonded thereto by vulcanization, while the inner peripheral surface of the second fastening member 20 is overlapped with the outer peripheral surface of the larger diameter side to be bonded thereto by vulcanization. In the present embodiment, the elastic rubber main body 22 is formed into a one-piece vulcanization molding equipped with the first fastening member 18 and the second fastening member 20.

[0043] In the present embodiment, the Fig. 7 to 9 are attached to the first fastening element 18 of the fastening body 12 having the structure described above.

[0044] The inside holder 14 has approximately the shape of a thick plate, and a screw hole 34, which runs through it in the up-down direction, is provided on the base side (left in Fig. 1). The upper opening of the screw hole 34 has an enlarged diameter, and a large-diameter recess 36 is formed to receive the screw head. Further, screw holes 38, 38 for fastening are formed at the tip portion of the inside retainer 14 to form a fastening portion 14 for fastening to the driver. The lower surface of the inside retainer 14 is formed with a step 42, and the base side of the step 42 is thinned by the thickness corresponding to the height of the step 42. At this thinned part, which constitutes a base side bottom surface 44, the inside retainer 14 is covered with the outer end surface 28 of the first fastening member 18 to be fastened thereto in a state in which the step 42 is positioned against the outer peripheral surface of the flange 26 of the first fastening member 18.

[0045] In addition, a concave groove 46 is formed on the outer peripheral surface of the inside holder 14. Specifically, in the present embodiment, the two concave grooves 46, 46 are formed on both sides in the transverse direction (left-right direction in Fig. 8) above the screw hole 34 on the base side of the inside holder 14. These two concave grooves 46 have a nearly constant width dimension (up-down dimension in Fig. 8) and a nearly constant depth (left-right dimension in Fig. 8) and are formed to extend continuously in a linear manner over the entire length in the thickness direction of the inside holder 14. Accordingly, both longitudinal sides of each of the concave grooves 46, 46 are open to the upper and lower end surfaces of the inside holder 14.

[0046] As in the Fig. 1 to 3, the base side of the inside holder 14 is then fixed to the first fixing member 18 by screwing a fixing screw 48 inserted through the screw hole 34 in the inside holder 14 into the screw hole 24 of the first fixing member 18, and the tip side of the inside holder 14 extends to a side in the direction perpendicular to the axis of the fixing body 12 (left-right direction in FIG. 1) to be installed therein. Then, the fixing portion 40 on the tip side of the inside holder 14 is mounted to the actuator by the fixing screw inserted into the screw hole 38.

[0047] Meanwhile, the outside holder 16 is attached to the second fastening element 16 of the fastening body 12. As shown in the Fig. As shown in Figures 1 to 6, the outside retainer 16 includes a fitting portion 50 approximately in the shape of an annular cylinder and a gate-shaped member 52 approximately in the shape of a gate, and the gate-shaped member 52 is covered by and fixed to the fitting portion 50. Then, the outside retainer 16 is fixed to the fixing body 12 by press-fitting the second fixing member 20 into the fitting portion 50 so that the gate-shaped member 52 can cover the outside of the first fixing member.

[0048] The gate-shaped element 52 has two leg portions 54, 54 positioned opposite each other and extending approximately in an up-down direction, and a beam portion 56 connecting the upper ends of these leg portions 54, 54. Then, the gate-shaped element 52 is arranged to radially overlap the upper opening of the fitting portion 50 by overlapping the lower ends of the two leg portions 54, 54 with the opposite upper end surfaces of the fitting portion 50.

[0049] A reinforcing rib 58 is integral with the gate-shaped element 52 at one edge thereof in the transverse direction (left-right direction in Fig. 1) and extends completely over the two leg parts 54, 54 and the beam part 56. In the center of the beam part 56, an insertion opening 60 is formed as an access opening for the fastening screw 48 of the inner holder 14. The surrounding edge of the insertion opening 60 is also provided with a reinforcing rib 62, which is annular.

[0050] Furthermore, on the other side of the gate-shaped element 52 in the transverse direction (left side in Fig. 1) a side wall element 64 is arranged so that it covers the opening of the gate-shaped element 52 to its other side in the transverse direction. As in Fig. 3, the central portion of the side wall member 64 is curved outward to form a side wall 66 in the shape of a curved plate. Furthermore, the gate-shaped member 52 is provided with an abutment portion 68 in the shape of an annular plate that directly coincides with the upper surface of the fitting portion 50 around the entire circumference to be fixed thereto by welding. Thus, on the periphery side of the abutment portion 68 formed in the shape of an annular plate, the side wall 66 is integrally formed so as to rise from the edge thereof. By overlapping the abutment portion 68 with the upper surface of the fitting portion 50, the side wall 66 is arranged so as to rise from a part of the circumference of the fitting portion 50.

[0051] In addition, the lower ends of the leg parts 54, 54 of the gate-shaped element 52 are covered with the abutment part 68 of the side wall element 64 and fastened thereto, while the other side of the opening edge of the gate-shaped element 52 in the transverse direction (left side in Fig. 1) is covered with and fixed to the side wall 66 of the side wall member 64. In the gate-shaped member 52 in which one opening is covered by the side wall member 64, the inside retainer 14 is arranged in a state of being inserted from the other opening. In other words, the base side of the inside retainer 14 is inserted into one opening of the gate-shaped member 52 to be fixed to the first fixing member 18 by the screw, and is assembled with the tip side of the inside retainer 14 protruding outward from the opening of the gate-shaped member 52. This makes it possible to position the outer peripheral surface of the inside retainer 14 at the base side and the inner peripheral surface of the gate-shaped member 52 of the outside retainer 16 opposite each other such that the outside of the inside retainer 14 is covered with a gap by the outside retainer 16.

[0052] In addition, a plurality of downwardly extending connecting members 72 are welded and fixed to the outer peripheral surface of the fitting portion 50 of the outboard bracket 16. A fastening part 74 is formed at the lower end of each connecting member 72, and the outboard bracket 16 is to be fixed to a vehicle body using a screw hole 76 at each fastening part 74. As apparent from the above description, the outboard bracket 16 in the present embodiment is configured by including the fitting portion 50, the gate-shaped member 52, the side wall member 64, and the connecting member 72, which are fixed to each other by welding or the like.

[0053] In the motor mount 10 of the present embodiment, the first stopper part and the second stopper part are arranged opposite each other with a certain distance in the up-down direction in the Fig. 1 and Fig. 2, which is the direction of relative displacement between the first fastening element 18 and the second fastening element 20, from the inside holder 14 and the outside holder 16, respectively. Furthermore, the stop function is exerted by the mutual abutment of the opposing surfaces of the inside holder 14 and the outside holder 16 via the rubber buffer layer.

[0054] In the present embodiment, the above-described rubber buffer layer consists of a rubber buffer element 80 attached to the inside holder 14. The rubber buffer element 80 is, as shown in Fig. 10 to 15, approximately in the shape of a pocket, and as shown in the enlarged view of a basic part in Fig. 16, it is mounted to cover an insertion portion 81 to be inserted into the outside holder 16 and located on the base side of the inside holder 14.

[0055] The rubber buffer member 80, which is formed approximately in the shape of a hollow rectangular pocket as a whole, has a peripheral wall 82 to be circumferentially overlapped with the outer peripheral surface (distal end surface and both side surfaces) of the insertion portion 81 of the inside holder 14, an upper wall 84 to cover the upper opening of the peripheral wall 82 to be overlapped with the upper surface of the insertion portion, and a lower wall 86 to cover the lower opening of the peripheral wall 82 to be overlapped with the lower surface of the insertion portion 81.

[0056] The peripheral wall 82 consists of three side walls 88a, 88b, and 88c, each approximately in the shape of a plate. The side wall 88a, which is to be overlapped with the distal end surface of the insertion portion 81, is formed with a through-hole 90 for venting air and adjusting the spring characteristics of the rubber buffer member 80 during assembly. Furthermore, a through-hole 92 is formed on the upper wall 84 at a position corresponding to the large-diameter recess 36, while an opening window 94 is formed on the lower wall 86 for directly overlapping the insertion portion 81 with the first fastening member 18.

[0057] Furthermore, on each inner surface of the side walls 88b, 88c of the rubber buffer member 80, an inner protrusion 96 is integrally formed to protrude toward the inside of the rubber buffer member 80. Each of the inner protrusions 96, 96 has a position and shape capable of being inserted into the corresponding one of the concave grooves 46, 46 formed in the inside holder 14 when the rubber buffer member 80 is mounted to the inside holder 14. Specifically, in the present embodiment, the inner projections 96, 96 are formed all the way from the top wall 84 to the bottom end, and each of the inner projections 96, 96 is designed in shape and size to abut against the respective inner surface of the concave grooves 96, 96, so that the inner projections 96, 96 can be fitted to the respective concave grooves 96, 96 to fill the space therein.Both end surfaces of each inner projection 96 in the longitudinal direction (up-down direction) of the concave groove 46 are not covered by the inner surface of the concave groove 46, so that they are free surfaces that cannot be directly influenced by retaining forces of the inside holder 14.

[0058] Additionally, in the present embodiment, an outer protrusion 98 projecting outward from the rubber buffer member 80 is formed on each of the outer surfaces of the side walls 88c, 88c at a position corresponding to the inner protrusion 96 on each inner surface. Furthermore, on the side walls 88b, 88c of the rubber buffer member 80, the area located away from the concave groove 46 on both sides in the transverse direction thereof is provided with a displacement regulating portion having a lower surface height than that of the distal end surface of the outer protrusion 98. Thus, in the present embodiment, the displacement regulating portion is configured by the area of ​​the side walls 88b, 88c overlapping the surface on the inside holder 14 located away from the concave groove 46 on both sides thereof, and such a displacement regulating portion is formed with a nearly constant thickness.

[0059] In other words: Assuming, as in Fig. 16 that the distance between the outer surface of the inner side holder 14 and the distal end surface of the outer projection 98 is α and the distance between the outer surface of the inner side holder 14 and the outer surface of the displacement control section, that is, the thickness dimension of the side walls 88b, 88c is β, the inequality α > β holds.

[0060] Furthermore, for each outer projection 98, the dimension γ in the transverse direction of the concave groove 46 is kept smaller than the dimension δ of the inner projection 96 (see Fig. 16) extending linearly along the center of the concave groove 46 in the transverse direction with a nearly constant cross-section in the longitudinal direction. Specifically, in the present embodiment, the outer protrusion 98 includes two linear ribs 100, 100 extending in the longitudinal direction of the concave groove 46. Also, the protrusion height of the linear rib 100 is smaller than the protrusion height of the inner protrusion 96, and the outer protrusion 98 is formed with a smaller rubber volume than the inner protrusion 96.

[0061] In the present embodiment, a plurality of grain protrusions 104 are formed on the surface of the upper wall 84 and the lower surface of the lower wall 86 in the rubber buffer element 80. The grain protrusion 104, which preferably has a smaller cross-section than the linear rib 100, is intended to reduce the impact noise upon impact.

[0062] The rubber buffer member 80 having the above-described structure is then positioned and held in a state where it covers the insertion portion 81 of the inside holder 14 to be installed thereon by inserting the inner projections 96, 96 into the concave grooves 46, 46. In the present embodiment, the rubber buffer member 80 is not adhered to the inside holder 14, but is installed thereon by utilizing the elasticity of the rubber buffer member 80.

[0063] In the above-described engine mount 10, the outboard bracket 16 and the inboard bracket 14 are disposed opposite each other with a certain distance in a state where they are mounted on a motor vehicle, and the divided vertical load of the drive in the up-down direction is applied to the engine mount. When excessive external forces such as large vibrations, impact loads, and the like due to centrifugal forces and road impacts during cornering are applied to the engine mount 10 during driving, it is considered that the stop function acts in a buffering manner by abutting the inboard bracket 14 and the outboard bracket 16 via the rubber buffer member 80.More specifically, for example, when large external forces are applied in the up-down direction, the stop function in the impact direction is exerted by the abutment between the approximately middle portion of the inside holder 14 in the longitudinal direction and the stop part 68 of the outside holder 16 via the lower wall 86 of the rubber buffer element 80, while the stop function in the rebound direction is exerted by the abutment between the insertion portion 81 of the inside holder 14 and the beam part 56 of the outside holder 16 via the upper wall 84 of the rubber buffer element 80.

[0064] When large external forces act in the left-right direction of the Fig. 2, the stop function is further exerted, for example, in the front-rear direction of the motor vehicle due to the abutment between the insertion portion 81 of the inside holder 14 and the leg part 54 of the outside holder 16 via the side walls 88b, 88c of the rubber buffer element 80.

[0065] Here, the inner protrusion 96 and the outer protrusion 98 are formed on the side wall 88b / 88c of the rubber buffer element 80, and a substantial rubber volume is ensured by the cooperation between the inner and outer protrusions 96, 98, while a free area is ensured on both sides of the inner protrusion 96 in the longitudinal direction, so that a degree of freedom of deformation is advantageously provided for the compressive deformation between the abutting surfaces in the pressure contact direction. This activates significant energy absorption and attenuation functions, whereby an excellent buffer effect can be achieved due to a soft spring characteristic.In particular, since the outer protrusion 98 having a smaller cross section than the inner protrusion 96 is first brought into contact with the opposite surface, the spring characteristic can be kept soft enough in the initial contact phase, thereby more effectively mitigating the impact noise and shock at the initial contact.

[0066] In addition, on the rubber buffer member 80, the area outside the concave groove 46 on both sides thereof is formed as a displacement regulating portion, and when external forces larger than that of the load range in which only the stop function is exerted by the aforementioned inner or outer projections 96, 98 are exerted, a relative displacement between the engine and the vehicle body can be securely restricted by abutting the inside holder 14 against the outside holder 16 via the displacement regulating portion which is held thinner than the inner or outer projections 96, 98.

[0067] In particular, in the present embodiment, since the rubber buffer member 80 is installed in a non-adherent manner on the inside holder 14, the buffering action of the rubber buffer member 80 in the various stopping functions described above can be exerted more effectively under a condition of long durability.

[0068] Also, in the present embodiment, since the inner projection 96 abuts against the bottom surface of the concave groove 46 with which it is to be fitted from the beginning, abnormal noise and impact caused when the inner projection 96 abuts against the bottom surface of the concave groove 46 can be avoided when the stopper function is activated.

[0069] Next, the Fig. 17 and Fig. 18 shows a rubber buffer element 106, which represents an engine mount as a vibration damping device of a second embodiment of the present invention. Fig. 19 is an enlarged view of a main part of the assembly between the rubber buffer member 106 and the inside bracket 14. Since the basic structure of the engine mount of the present embodiment is the same as that of the first embodiment, the figures show only the rubber buffer member 106. Also, a detailed description of the elements and parts identical to those of the first embodiment will be omitted by assigning the same reference numerals as those of the first embodiment in the figures.

[0070] Also in the present embodiment, an inner protrusion 108 is formed on each inner surface of the side walls 88b and 88c of the rubber buffer member 106, while an outer protrusion 110 is formed at positions corresponding to the inner protrusion 108 on each outer surface of the side walls 88b, 88c. In the present embodiment, the outer protrusion 110 is formed as a linear ridge 110 extending in the longitudinal direction of the concave groove 46. The outer protrusion 110 is tapered on both sides in the transverse direction, with an approximately trapezoidal cross section extending from the side walls 88b, 88c. Therefore, the outer protrusion 110 of the present embodiment is wedge-shaped, with its width gradually decreasing from the base to the tip.

[0071] Under these conditions, the outer projection 110 of the present embodiment, as shown in Fig.As shown in Figure 19, assuming that the distance between the outer surface of the inner retainer 14 and the distal end surface of the outer projection is α', and the distance between the outer surface of the inner retainer 14 and the outer surface of the displacement regulating portion, that is, the thickness dimension of the side walls 88b, 88c is β', the inequality α' > β' holds. Furthermore, the width dimension γ' of the outer projection 110 is made smaller than the width dimension δ' of the inner projection 108 and the concave groove 46. The width dimension of the base side of the outer projection 110 is made substantially smaller than the width dimension of the inner projection 108 and is formed in a size and position that fits into the concave groove 46. Also, the projection height of the outer projection 110 is made larger than that of the inner projection 108.

[0072] As in the first embodiment, in the present embodiment, an excellent buffer function can be achieved based on the elastic deformation of the inner protrusion 108 and the outer protrusion 110, and the same effect as in the first embodiment can be achieved by using the rubber buffer member 106 of the present embodiment, therefore, various effects similar to those of the first embodiment can be achieved in the motor mount of the present embodiment using the rubber buffer member 106.

[0073] Embodiments of the present invention have been described in detail above, but the present invention is not limited to these specific descriptions. For example, in one of the above embodiments, the concave groove 46 has longitudinally open ends on both sides. However, even if the concave groove 46 itself is not longitudinally open, end surfaces with free surfaces may be formed in the concave groove 46 by making the inner protrusion inserted into the concave groove have a length that does not quite reach the longitudinal end surfaces of the concave groove 46.

[0074] It is also possible to provide the inner or outer protrusion of the rubber buffer layer with a structure with variable heights along the longitudinal direction of the concave groove, or to design it as a composite of a plurality of independent protrusions along the longitudinal direction of the concave groove, which can ensure the degree of freedom in adjusting the stop functions to the required properties. Furthermore, it is possible to form the inner protrusion with a plurality of linear ridges extending along the longitudinal direction of the concave groove, or to form the outer protrusion with three or more linear ridges extending in the same direction.

[0075] Furthermore, in the above-described embodiments, aspects of the engine mount were described as the vibration damping device relating to the present invention, but the vibration damping device relating to the present invention is not limited to the engine mount, but can also be applied to the body mount, suspension stay, underbody mount, and so on. Also, specific shapes of the inboard bracket and the outboard bracket are not limited to those of the above-described embodiments, and it is also possible to configure the outboard bracket without providing the side wall member 64, for example. Furthermore, the inboard bracket and the outboard bracket are not essential in the present invention, and it is possible to directly provide the first or second mounting member with the first or second stopper part.

[0076] In addition, it is possible to configure the stop mechanism in the up-down direction with a different element than that of the stop mechanism in the transverse direction (front-rear direction of the vehicle in the embodiments described above). LIST OF REFERENCE SYMBOLS

[0077] 10: Motor mount (vibration damping device); 14: Inside bracket; 16: Outside bracket; 18: First fastener; 20: Second fastener; 22: Elastic rubber main body; 46: Concave groove; 80, 106: Rubber buffer element (rubber buffer layer); 81: Insertion portion; 88b, 88c: Side wall (displacement control portion); 96, 108: Inner projection; 110: Outer projection; 100: Linear ridge

Claims

[1] Vibration damping device (10), comprising: a first (18) and a second fastening element (20) connected to each other by an elastic rubber main body (22); and a first (14) and a second stop part (16) arranged opposite each other in a direction of relative displacement of the first (18) and the second fastening element (20) while abutting each other via a rubber buffer layer (80), wherein the vibration damping device (10) characterized by is that: a concave groove (46) is provided on one of the other opposite surfaces of at least one of the first (14) and second stop members (16); an inner projection (96) is formed on the rubber buffer layer (80) covered with the opposite surface so as to be inserted into the concave groove (46), and both sides of the inner projection (96) in the longitudinal direction of the concave groove (46) are free end surfaces; an outer projection (98) is formed on a structural part of the inner projection (96) on the rubber buffer layer (80) so as to project outwardly from the concave groove (46), wherein a dimension of the outer projection (98) in the transverse direction of the concave groove (46) is smaller than that of the inner projection (96); and a displacement regulating portion having a lower surface height than that of the distal end surface of the outer projection (98) is formed on the rubber buffer layer (80) covering a region of the opposite surface located transversely away from both sides of the concave groove (46). [2] The vibration damping device (10) according to claim 1, wherein the rubber buffer layer (80) is covered with the at least one of the first (14) and second stopper parts (16) in a non-adherent manner at least on the structural part of the inner projection (96). [3] The vibration damping device (10) according to claim 1 or 2, wherein the inner projection (96) abuts against an inner surface of the concave groove (46). [4] The vibration damping device (10) according to any one of claims 1 to 3, wherein the outer projection (98) comprises a plurality of linear ridges extending in the longitudinal direction of the concave groove. [5] Vibration damping device (10) according to one of claims 1 to 4, wherein the outer projection (98) is formed with a smaller rubber volume than that of the inner projection. [6] Vibration damping device (10) according to one of claims 1 to 5, wherein the outer projection (98) is wedge-shaped. [7] The vibration damping device (10) according to any one of claims 1 to 6, wherein the displacement control portion is formed to extend with a nearly constant thickness on the opposite surface. [8] Vibration damping device (10) according to one of claims 1 to 7, wherein the concave groove (46) extends continuously over both ends of the opposite surface of at least one of the first (14) and second stopper parts (16) and both longitudinal sides of the concave groove (46) are open at the corresponding ends of the opposite surface. [9] The vibration damping device (10) according to any one of claims 1 to 8, wherein an inside retainer (14) is attached to the first fixing member (18), while an outside retainer (16) is attached to the second fixing member (20) so as to overlap an outside of the inside retainer (14) with a gap, and the first (14) and the second stopper parts (16) are composed of the inside (14) and the outside retainer (16), respectively, while the inside retainer (14) is provided with the concave groove (46) and the rubber buffer layer (80). [10] The vibration damping device (10) according to claim 9, wherein a gate-shaped member (52) is provided on the outside bracket (16) so as to cover an outside of the first fixing member (18), while an insertion portion is provided on the inside bracket (14) so ​​as to be inserted into the gate-shaped member (52) of the outside bracket (16) from a lateral side and fixed to the first fixing member (18), and a rubber buffer member (80) constituting the rubber buffer layer (80) is installed on the inside bracket (14) in a state of covering the insertion portion.

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