Bracket-equipped vibration-isolating device

Abstract

The present invention provides a bracket-equipped vibration-isolating device having a novel structure, the device being capable of suppressing an exacerbation of the vibration state of a target of vibration-isolation due to resonance while achieving sufficient weight reduction.　Provided is a bracket-equipped vibration-isolating device 10 in which a bracket 16 is attached to a vibration-isolating device 12, wherein: the bracket 16 comprises a mounting portion 36 to which the vibration-isolating device 12 is mounted, an attachment leg portion 42 formed integrally with the mounting portion 36 and extending toward one side; a stopper vertical wall portion 48 formed integrally with the mounting portion 36 and protruding toward the other side, and a stopper top wall portion 62 attached to the protruding end of the stopper vertical wall portion 48; and the stopper top wall portion 62 is formed separately from a material having a greater specific gravity than that of the mounting portion 36.

Description

Anti-vibration device with bracket

[0001] The present invention relates to an anti-vibration device used, for example, in an engine mount of an automobile, and more particularly to a bracket-equipped anti-vibration device having a bracket that is attached to an object to be anti-vibration-damped.

[0002] Conventionally, there have been known vibration-damping devices used, for example, in automobile engine mounts, etc. As shown in Japanese Patent No. 4718500 (Patent Document 1), for example, the vibration-damping device has a structure in which a first mounting member and a second mounting member are connected by a main rubber elastic body.

[0003] Furthermore, the vibration isolation device may be attached to the object to be isolated via a bracket, for example. Patent Document 1 discloses a structure in which a lower mounting fixture 12 is attached to the support side, which is the object to be isolated, via a first bracket 70.

[0004] Patent No. 4718500

[0005] However, with the recent trend toward lighter vehicles, the deformation rigidity of such vibration-damping targets is decreasing. As a result, the resonant frequency of the vibration-damping target is lowered, making it easier for the target to resonate with input vibrations. This could significantly worsen the vibration state of the target due to the resonance of the target when vibrations are input.

[0006] Furthermore, because brackets attached to vibration-damping targets have traditionally been made of iron, it has been thought that the mass of the bracket can be used to dampen the resonance of the target. However, because iron brackets have a large mass, it is difficult to meet the demand for lighter vehicles, etc., and in recent years, they have been replaced by lightweight aluminum alloys and synthetic resins, making it difficult to obtain sufficient damping action using the mass of the bracket.

[0007] The problem to be solved by the present invention is to provide a bracket-equipped vibration isolation device of a novel structure that is sufficiently lightweight and can suppress deterioration of the vibration state due to resonance of the object to be vibration-isolated.

[0008] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0009] The first aspect is a bracket-equipped vibration-damping device in which a bracket is attached to a vibration-damping device, wherein the bracket comprises an attachment portion to which the vibration-damping device is attached, an attachment leg portion formed integrally with the attachment portion and extending out on one side, a stopper vertical wall portion formed integrally with the attachment portion and protruding out on the other side, and a stopper top wall portion attached to the protruding end of the stopper vertical wall portion, and the stopper top wall portion is formed separately from a material with a higher specific gravity than the attachment portion.

[0010] With a bracket-equipped vibration isolation device constructed according to this aspect, deterioration of the vibration state due to resonance of the vibration isolation target when vibration is input can be suppressed by a damping action that utilizes the mass of the bracket attached to the vibration isolation target at the mounting legs. In particular, the stopper top wall portion that constitutes the portion of the bracket away from the vibration isolation target is formed separately from the bracket using a material with a higher specific gravity than the portion closer to the vibration isolation target, including the mounting portion, so that the weight can be reduced compared to when the entire bracket is made of a material with a higher specific gravity, while still efficiently achieving vibration suppression effect due to the damping action when vibration is input.

[0011] Because the stopper vertical wall portion and the stopper top wall portion exert their stopper function by abutting against other components, they need to have smooth stopper surfaces with high dimensional accuracy. However, the stopper top wall portion needs to be made of a material with a high specific gravity to prevent the bracket from becoming too large, and it may be difficult to achieve high dimensional accuracy on the surface. In such cases, it becomes necessary to improve the dimensional accuracy of the stopper surface by processing such as cutting after molding. Therefore, in this embodiment, the stopper vertical wall portion that constitutes the stopper surface is separate from the stopper top wall portion that constitutes the other stopper surfaces and is formed integrally with the mounting portion. This allows the stopper vertical wall portion, which does not need to be made of a material with a high specific gravity, to be formed from, for example, an aluminum alloy or synthetic resin, thereby making it possible to mold the stopper surface constituted by the stopper vertical wall portion with high dimensional accuracy without requiring post-processing such as cutting.

[0012] In the second aspect, in the bracket-equipped vibration-damping device described in the first aspect, the mounting portion of the bracket is composed of a cylindrical press-fit tube portion, and the vibration-damping device is attached to the bracket by being pressed into and fixed to the press-fit tube portion through a pair of opposing wall portions provided on the stopper vertical wall portion, and a stopper portion is provided at the opening of the press-fit tube portion on the opposite side to the stopper top wall portion, which protrudes toward the inner circumference and prevents the vibration-damping device from coming off to the opposite side of the stopper top wall portion.

[0013] In a bracket-equipped vibration-damping device constructed in accordance with this embodiment, the stopper top wall portion of the bracket is separate from the press-fit tubular portion and the stopper vertical wall portion, so that, for example, before attaching the stopper top wall portion to the stopper vertical wall portion, the vibration-damping device can be easily pressed into and fixed to the press-fit tubular portion through the stopper vertical wall portion.

[0014] When the vibration-damping device is attached to the bracket by being pressed into a press-fit cylindrical portion, the vibration-damping device can become detached from the press-fit cylindrical portion when a large load is applied. In particular, if the vibration-damping device is pressed into the press-fit cylindrical portion from the side opposite the target to be damped and comes off the press-fit cylindrical portion toward the target, it has a significant impact on vibration-damping performance. Therefore, by using a retaining portion that protrudes toward the inner periphery at the opening of the press-fit cylindrical portion to prevent the vibration-damping device from coming off toward the target, the desired vibration-damping performance can be stably obtained.

[0015] In a third aspect, in the bracket-equipped vibration-damping device described in the first or second aspect, the stopper top wall portion integrally comprises a connecting plate portion attached across a pair of opposing wall portions of the stopper vertical wall portion, and a mass adjustment portion that protrudes partially from the connecting plate portion and adjusts the mass of the stopper top wall portion.

[0016] In a bracket-equipped vibration isolation device constructed according to this aspect, the stopper surface of the stopper top wall portion can be formed by a connecting plate portion attached across multiple stopper vertical wall portions. In addition, the mass of the stopper top wall portion can be easily adjusted by a mass adjustment portion protruding from the connecting plate portion, and deterioration of the vibration state due to resonance of the vibration isolation device can be improved by a damping effect, etc.

[0017] According to the present invention, in a bracket-equipped vibration isolation device, it is possible to suppress deterioration of the vibration state due to resonance of the object to be vibration-isolated while achieving a sufficient weight reduction.

[0018] 1 is a perspective view showing a bracket-equipped vibration-damping device according to a first embodiment of the present invention; FIG. 1 is a plan view of the bracket-equipped vibration-damping device shown in FIG. 1; FIG. 1 is a bottom view of the bracket-equipped vibration-damping device shown in FIG. 1; FIG. 1 is a front view of the bracket-equipped vibration-damping device shown in FIG. 1; FIG. 1 is a left side view of the bracket-equipped vibration-damping device shown in FIG. 1; FIG. 5 is a VI-VI cross-sectional view of FIG. 5; FIG. 4 is a VII-VII cross-sectional view of FIG. 4;

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] 1 to 7 show an automotive engine mount 10 as a first embodiment of a bracket-equipped vibration isolation device constructed in accordance with the present invention. The engine mount 10 has a structure in which a first bracket 14 and a second bracket 16 are attached to a mount body 12 serving as a vibration isolation device. In the following description, as a general rule, the up-down direction refers to the up-down direction in FIG. 4, the front-rear direction refers to the up-down direction in FIG. 2, and the left-right direction refers to the left-right direction in FIG. 2.

[0021] The mount main body 12 has a structure in which a first mounting member 18 and a second mounting member 20 are interconnected by a main rubber elastic body 22. The first mounting member 18 has a generally cylindrical upper portion and a generally hemispherical lower portion, and a screw hole 23 that opens into the flat upper surface and extends in the vertical direction is formed. The second mounting member 20 has a thin-walled, large-diameter, generally cylindrical shape overall, and an annular step portion 24 provided in the axial middle portion has a larger diameter on the upper side than on the lower side. The first mounting member 18 and the second mounting member 20 are hard members formed from metal, fiber-reinforced synthetic resin, or the like, and may be formed from the same material or different materials.

[0022] The first mounting member 18 is disposed above the second mounting member 20, and a main rubber elastic body 22 is disposed between the first mounting member 18 and the second mounting member 20. The main rubber elastic body 22 is formed in a generally truncated cone shape with a diameter that decreases toward the top, with the first mounting member 18 vulcanization-bonded to the upper end and the inner peripheral surface of the second mounting member 20 vulcanization-bonded to the outer peripheral surface of the lower part. The main rubber elastic body 22 is formed with an inverted mortar-shaped recess 26 that opens to the bottom surface.

[0023] As is conventionally known, the mount body 12 exhibits damping and insulating effects due to the elastic deformation of the main rubber elastic body 22 when vibration is input. The mount body 12 may be provided with a fluid chamber filled with a non-compressible fluid, and may be a fluid-filled vibration-damping device that exhibits vibration-damping effects through the flow action of the fluid. The mount body 12 may also be an active fluid-filled vibration-damping device that actively applies an exciting force to the fluid chamber to offset and reduce input vibration, or a switchable fluid-filled vibration-damping device that switches vibration-damping characteristics in response to input vibration using the anti-resonance action of a fluid flow path or a valve mechanism.

[0024] A first bracket 14 and a second bracket 16 are attached to the mount body 12 having such a structure. The first bracket 14 is attached to a first attachment member 18 of the mount body 12, and the second bracket 16 is attached to a second attachment member 20 of the mount body 12.

[0025] The first bracket 14 is a highly rigid member formed of metal, fiber-reinforced synthetic resin, or the like. The first bracket 14 includes a connecting shaft portion 30 that is superimposed on the upper surface of the first mounting member 18 and secured by bolts 28. A fastening portion 32 that is secured to a power unit 76 (described later) is integrally formed at an end of the connecting shaft portion 30 that protrudes laterally from the first mounting member 18. The fastening portion 32 extends from the connecting shaft portion 30 to both the front and rear ends and has a plurality of bolt holes 34 that are aligned in the front-to-rear direction. The fastening portion 32 can be secured to the power unit 76 by bolts (not shown) inserted through the bolt holes 34. The shape of the first bracket 14 is merely exemplary, and the outer shape of the fastening portion 32 and the number and arrangement of the bolt holes 34 can be appropriately changed depending on the mounting structure of the power unit 76 (described later).

[0026] The second bracket 16 has a press-fit tubular portion 36 as an attachment portion into which the second mounting member 20 of the mount main body 12 is press-fitted and fixed. The press-fit tubular portion 36 has a generally cylindrical shape, allowing the second mounting member 20 to be inserted from above. A flange-shaped stopper abutment portion 38 that protrudes to the left is provided at the upper end of the press-fit tubular portion 36. The stopper abutment portion 38 has an upper surface that widens perpendicular to the vertical direction and a lower surface that slopes downward to the right.

[0027] A retaining portion 40 that protrudes toward the inner circumference is integrally formed at the opening on the lower side of the press-fit cylindrical portion 36. The retaining portion 40 may be provided at multiple locations in the circumferential direction, or may be provided continuously around the entire circumference, but in this embodiment, the retaining portion 40 is provided at two locations in the circumferential direction, and the two retaining portions 40, 40 are arranged spaced apart from each other in the circumferential direction.

[0028] The second bracket 16 has a pair of mounting legs 42, 42 extending downward from the press-fit cylindrical portion 36. The mounting legs 42 are integrally formed on both the front and rear sides of the press-fit cylindrical portion 36 and extend downward beyond the lower end of the press-fit cylindrical portion 36. Mounting portions 44 that are fixed to a subframe 78 (described below) are provided at the lower end portions of the mounting legs 42 and protrude outward in the front and rear directions, allowing the second bracket 16 to be mounted to the subframe 78 using bolt holes 46 in the mounting portions 44. Note that the mounting legs 42, 42 can also be provided with reinforcing ribs that protrude outward in the front and rear directions at both left and right ends to improve their deformation rigidity, for example.

[0029] The second bracket 16 includes a stopper vertical wall portion 48 that protrudes upward from the press-fit cylindrical portion 36. The stopper vertical wall portion 48 is formed integrally with the press-fit cylindrical portion 36 and protrudes upward beyond the upper end of the press-fit cylindrical portion 36. The stopper vertical wall portion 48 is integrally provided with a pair of opposing wall portions 50, 50 that are formed integrally on both the front and rear sides of the press-fit cylindrical portion 36, a rear wall portion 52 that is formed integrally on the right side of the press-fit cylindrical portion 36, and connecting wall portions 54, 54 that connect the opposing wall portions 50, 50 and the rear wall portion 52 in the circumferential direction. The pair of opposing wall portions 50, 50 extend approximately perpendicular to the front-to-rear direction, the rear wall portion 52 extends approximately perpendicular to the left-to-right direction, and the connecting wall portion 54 extends outward in the front-to-rear direction, sloping leftward. The pair of opposing wall portions 50, 50 are disposed at the same positions as the mounting legs 42, 42 in the circumferential direction of the press-fit cylindrical portion 36, and are provided integrally and continuously in the vertical direction with the mounting legs 42, 42. A rib-shaped connecting portion 56 that protrudes to the right and extends vertically is formed in the front-to-rear central portion of the rear wall portion 52.

[0030] A plurality of screw holes 58 are formed at the upper end of the stopper vertical wall portion 48. The screw holes 58 are formed in the left end portions of the pair of opposing wall portions 50, 50 and in the connecting portion 56 of the rear wall portion 52.

[0031] The second bracket 16 is formed integrally with the press-fit cylindrical portion 36, the mounting legs 42, 42, and the stopper vertical wall portion 48, which together form a single member, the bracket body 60. The bracket body 60 is preferably made of a material with a relatively low specific gravity, such as a light metal such as an aluminum alloy or a fiber-reinforced synthetic resin.

[0032] A stopper top wall portion 62 is disposed above the bracket main body 60 of the second bracket 16. The stopper top wall portion 62 is formed separately from the bracket main body 60 and is attached to the bracket main body 60. As shown in Figures 1 and 4 to 7, the stopper top wall portion 62 integrally includes a plate-shaped connecting plate portion 64 and a mass adjustment portion 66 that protrudes upward from the connecting plate portion 64.

[0033] The connecting plate 64 has an outer shape that roughly corresponds to the outer peripheral shape of the stopper vertical wall 48, and is longer in the front-to-rear direction than in the left-to-right direction overall. A connecting piece 68 that protrudes toward the right is provided in the front-to-rear center of the connecting plate 64. The connecting plate 64 has bolt holes 70 that penetrate vertically in each of the front and rear corners of the left end portion and the connecting piece 68. The connecting plate 64 has both front and rear end portions and a right end portion that are overlapped from above with the stopper vertical wall 48 of the bracket main body 60, and is fixed to the stopper vertical wall 48 by bolts 72 inserted through the bolt holes 70 and threaded into the screw holes 58. Thus, the stopper top wall 62 with the connecting plate 64 is attached to the upper end portion of the stopper vertical wall 48. The connecting plate portion 64 of the stopper top wall portion 62 is disposed across the pair of opposing wall portions 50, 50 and the rear wall portion 52 of the stopper vertical wall portion 48, and extends approximately perpendicular to the up-down direction.

[0034] The mass adjustment portion 66 is formed integrally with the connecting plate portion 64 and is provided so as to partially protrude from the upper surface of the connecting plate portion 64. In this embodiment, the mass adjustment portion 66 is in the shape of a rectangular block, but the shape of the mass adjustment portion 66 is not particularly limited, and can be changed as appropriate so that an appropriate mass size and distribution can be set in the stopper top wall portion 62.

[0035] The stopper top wall portion 62 is formed of a material with a higher specific gravity than the bracket main body 60 including the press-fit tube portion 36. Specifically, the second bracket 16 is formed, for example, by combining the bracket main body 60 made of an aluminum alloy with the stopper top wall portion 62 made of iron. Alternatively, the second bracket 16 can be formed, for example, by combining the bracket main body 60 made of a fiber-reinforced synthetic resin with the stopper top wall portion 62 made of a metal such as iron or an aluminum alloy. The specific gravity of the material forming the stopper top wall portion 62 is preferably 1.5 times or more, and more preferably 2.5 times or more, that of the material forming the bracket main body 60. The stopper top wall portion 62 is desirably formed of a heavy metal such as iron in order to advantageously function as a mass that exerts a damping effect, as described below.

[0036] In this embodiment, the bracket main body 60 is a die-cast product made of aluminum alloy, and the stopper top wall portion 62 is a die-formed product made of iron, so that the unevenness of the surface of the stopper top wall portion 62 is greater than the unevenness of the surface of the bracket main body 60. The lower surface of the connecting plate portion 64 of the stopper top wall portion 62, which constitutes the stopper surface of the rebound stopper described below, is reduced in unevenness by post-processing such as cutting after molding, thereby improving dimensional accuracy. On the other hand, the bracket main body 60, which has high dimensional accuracy during molding, has its entire surface, including the stopper surfaces of the front and rear stoppers and the bound stopper described below, remaining as the surface at the time of molding without undergoing post-processing such as cutting.

[0037] Note that, when the bracket body 60 is in a standalone state without the stopper top wall portion 62 attached, the second attachment member 20 of the mount body 12 is press-fitted and fixed from above into the press-fit tubular portion 36 through the space between the opposing surfaces of the pair of opposing wall portions 50, 50 of the stopper vertical wall portion 48. In this way, the stopper top wall portion 62, which is disposed in a position covering the upper side of the press-fit tubular portion 36 in the second bracket 16, is separate from the bracket body 60 including the press-fit tubular portion 36, which makes it easy to attach the mount body 12 to the press-fit tubular portion 36.

[0038] Then, with the mount main body 12 attached to the bracket main body 60, the first bracket 14 is bolted to the first mounting member 18, and then the connecting plate portion 64 of the stopper top wall portion 62 is bolted to the bracket main body 60 so as to straddle the pair of opposing wall portions 50, 50, thereby covering the upper right ends of the mount main body 12 and the first bracket 14 with the stopper top wall portion 62. In this way, by bolting the first mounting member 18 and the first bracket 14 together before attaching the stopper top wall portion 62 to the bracket main body 60, the work of tightening the bolts 28 that secure the first mounting member 18 and the first bracket 14 together is also facilitated.

[0039] With the second bracket 16 attached to the mount body 12, a pair of opposing wall portions 50, 50 of the stopper vertical wall portion 48 are disposed a predetermined distance apart on both the front and rear sides of the connecting shaft portion 30 of the first bracket 14, and a front-rear stopper that limits the amount of relative displacement between the first mounting member 18 and the second mounting member 20 in the front-rear directions is formed by the abutment between the first bracket 14 and the opposing wall portions 50, 50. In addition, a stopper top wall portion 62 is disposed above the first bracket 14, and a rebound stopper that limits the amount of relative displacement between the first mounting member 18 and the second mounting member 20 in the vertical separation side (rebound side) is formed by the abutment between the first bracket 14 and the stopper top wall portion 62. Furthermore, a stopper abutment portion 38 of the press-fit tubular portion 36 is disposed below the connecting shaft portion 30 of the first bracket 14, and a bound stopper that limits the amount of relative displacement of the first mounting member 18 and the second mounting member 20 toward the vertical approach side (bound side) is formed by the abutment between the first bracket 14 and the press-fit tubular portion 36. Furthermore, a rear wall portion 52 is disposed on the right side of the connecting shaft portion 30 of the first bracket 14, and a lateral stopper that limits the amount of relative displacement of the first mounting member 18 toward the right with respect to the second mounting member 20 is formed by the abutment between the first bracket 14 and the rear wall portion 52. In this embodiment, a cushioning rubber 74 is attached to the connecting shaft portion 30 of the first bracket 14, and the first bracket 14 and the second bracket 16 abut indirectly via the cushioning rubber 74, thereby mitigating impact and sound generated when they abut.

[0040] The second mounting member 20 of the mount main body 12 is prevented from coming off downward with respect to the press-fit tubular portion 36 of the second bracket 16. That is, the lower opening of the press-fit tubular portion 36 is provided with anti-slip portions 40, 40 that protrude inward, and these anti-slip portions 40, 40 overlap the stepped portion 24 of the second mounting member 20 in axial projection. Therefore, the amount of downward displacement of the second mounting member 20 relative to the press-fit tubular portion 36 is limited by the engagement between the stepped portion 24 of the second mounting member 20 and the anti-slip portions 40, 40 of the press-fit tubular portion 36, preventing the second mounting member 20 from coming off downward with respect to the press-fit tubular portion 36. When engine mount 10 is installed on a vehicle, as described below, the shared support load of power unit 76 acts downward, so second mounting member 20 is more likely to come loose downward than upward from press-fit tubular portion 36, and the impact on vibration-damping performance, etc., when loosening occurs, is more likely to be greater if loosening occurs downward. Therefore, by press-fitting second mounting member 20 into press-fit tubular portion 36 of second bracket 16 from above and preventing second mounting member 20 from coming loose downward with retaining portion 40, more stable vibration-damping performance can be obtained.

[0041] As shown in Figure 4, the engine mount 10 constructed as described above has the first bracket 14 attached to the first mounting member 18 attached to the side of the power unit 76, which is a vibration source, and the second bracket 16 attached to the second mounting member 20 attached to the side of the subframe 78, which is the target for vibration isolation. In this manner, the engine mount 10 is mounted to the vehicle, and the power unit 76 is supported in a vibration-isolating manner on the subframe 78 via the engine mount 10. Note that the engine mount 10 shown in Figures 1 to 7 is in a standalone state, not mounted to the vehicle; when mounted to the vehicle, the first mounting member 18 and the second mounting member 20 are displaced toward each other in the vertical direction due to the input of the shared support load of the power unit 76.

[0042] When vibrations are input from the power unit 76 to the engine mount 10, the first mounting member 18 attached to the power unit 76 and the second mounting member 20 attached to the subframe 78 are displaced relative to each other, causing elastic deformation of the main rubber elastic body 22. This produces vibration-proofing effects such as vibration damping and vibration isolation, reducing the vibrations transmitted to the subframe 78.

[0043] However, if the subframe 78 resonates with the transmitted vibrations, the vibrations exerted from the subframe 78 into the vehicle interior may be amplified, resulting in a problem of worsening the vibration state. Therefore, the engine mount 10 of this embodiment functions as a vibration damping device that reduces the vibration amplification effect caused by resonance of the subframe 78 when mounted on the vehicle.

[0044] In other words, by attaching the engine mount 10 to the vehicle, a vibration damping device consisting of the bracket main body 60 as a spring component and the stopper top wall portion 62 as a mass component is formed on the subframe 78, and the vibration damping effect of the vibration damping device is exerted at the resonant frequency of the subframe 78.

[0045] In the second bracket 16, the stopper top wall portion 62, which serves as a mass component, is formed from a material with a higher specific gravity than the bracket main body 60, which serves as a spring component. This makes it possible to reduce the weight of the second bracket 16 while sufficiently increasing the mass of the mass component in the vibration damping device formed by the second bracket 16, compared to when the entire second bracket 16 is formed from a material with a higher specific gravity. In particular, the stopper top wall portion 62 is molded separately from the bracket main body 60 and is fixed to the bracket main body 60 with bolts as a separate part, so it is easy to form the stopper top wall portion 62 from a material with a higher specific gravity than the bracket main body 60.

[0046] The stopper top wall portion 62, which is a mass component made of a high-density material, constitutes the upper end portion of the second bracket 16 that is farthest from the subframe 78, so that the displacement of the mass component in response to vibration input from the subframe 78 is increased, thereby efficiently exerting vibration damping action.

[0047] The mass of the stopper top wall portion 62 can be set with a large degree of freedom using the mass adjustment portion 66. This makes it easy to tune the frequency of the vibration damping device to match the resonance of the subframe 78, which can be a problem when vibration is input, and makes it possible to more effectively suppress deterioration of the vibration state due to resonance of the subframe 78.

[0048] In this embodiment, because the bracket body 60 is an aluminum die-cast product, the stopper surfaces of the rebound stopper, front and rear stoppers, and side stoppers of the bracket body 60 (the upper surface of the stopper abutment portion 38 of the press-fit cylindrical portion 36, the opposing inner surfaces of the pair of opposing wall portions 50, 50, and the left surface of the rear wall portion 52) have high dimensional accuracy during molding, and do not require post-processing such as cutting. Therefore, of the stopper surfaces of the second bracket 16, the only portion that requires post-processing such as cutting is the stopper surface of the rebound stopper (the lower surface of the stopper top wall portion 62), reducing the amount of work required for post-processing.

[0049] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific descriptions. For example, the stopper vertical wall portion of the bracket may not have the rear wall portion 52 and the connecting wall portions 54, 54 of the first embodiment, and may be composed of only the pair of opposing wall portions 50, 50. Furthermore, the stopper vertical wall portion may omit the connecting wall portions 54, 54, and the pair of opposing wall portions 50, 50 and the rear wall portion 52 may be spaced apart from each other in the circumferential direction, rather than being continuous in the circumferential direction.

[0050] The mass adjustment portion is not essential to the stopper top wall portion, and the mass of the stopper top wall portion can be adjusted by, for example, adjusting the thickness of the connecting plate portion. The mass of the stopper top wall portion can also be adjusted by extending the connecting plate portion further in the front-rear or left-right directions. The stopper top wall portion may also include an additional mass that is provided after the fact in consideration of tuning the resonance frequency, etc.

[0051] In the first embodiment, a structure has been exemplified in which the mount main body 12 serving as the vibration-damping device is press-fitted and fixed from above into the press-fit tubular portion 36 of the second bracket 16 serving as the bracket, but, for example, the vibration-damping device can also be configured to be attached by being press-fitted from below into the press-fit tubular portion 36 of the bracket. In this case, a retaining portion that protrudes toward the inner periphery may be provided at the upper opening of the press-fit tubular portion 36 to prevent the vibration-damping device from coming out upward from the press-fit tubular portion 36. Also, for example, a recessed mounting portion may be provided on the right side surface of the bracket, and the vibration-damping device may be attached to the bracket by inserting it into the mounting portion of the bracket from the right.

[0052] In the first embodiment, an example was shown in which the second bracket 16 is attached to the mount body 12 by press-fitting the second mounting member 20, but the mounting structure for the vibration isolation device and the bracket is not limited to press-fitting, and various fixing structures can be used, for example, caulking, bolt fixing, mechanical engagement, welding, etc. Note that the first bracket 14 may be fixed to the first mounting member 18 by means other than bolt fixing (for example, press-fitting, etc.).

[0053] The present invention can also be applied to a bracket-attached vibration isolation device in which the vibration isolation device is mounted in an inverted state on a bracket, as in Patent Document 1. That is, the first bracket may be attached to a first mounting member 18 that is a thin-walled, large-diameter cylinder, and the second bracket as a bracket may be attached to a second mounting member that is a small-diameter block. Also, in the first embodiment, the first bracket 14 attached to the vibration source (power unit 76) side is not essential; for example, the first mounting member 18 may be attached directly to a mounting portion that is integrally provided on the power unit 76 side.

[0054] Furthermore, the mounting leg portion may be one that positions the actual connecting support position for the vibration-damping object on the opposite side of the stopper top wall portion relative to the mounting portion, and depending on the shape of the vibration-damping object, additional or auxiliary mounting legs may be provided that are attached to the vibration-damping object, for example, by protruding from the mounting portion to the outer periphery.

[0055] In the first embodiment, the subframe 78 of an automobile is exemplified as the object to be isolated from vibrations, but the object to be isolated from vibrations may be, for example, the body of the automobile (chassis frame or monocoque), etc. The bracket-equipped vibration isolation device can also be applied to, for example, a motor mount, etc., and can also be applied to mounts other than those for supporting a power unit in a vibration-isolating manner.

[0056] REFERENCE SIGNS LIST 10 Engine mount (first embodiment of vibration-damping device with bracket) 12 Mount main body (vibration-damping device) 14 First bracket 16 Second bracket (bracket) 18 First mounting member 20 Second mounting member 22 Main rubber elastic body 23 Screw hole 24 Step portion 26 Recessed portion 28 Bolt 30 Connecting shaft portion 32 Fastening portion 34 Bolt hole 36 Press-fitting cylindrical portion 38 Stopper abutment portion 40 Prevention portion 42 Mounting leg portion 44 Mounting portion 46 Bolt hole 48 Stopper vertical wall portion 50 Opposing wall portion 52 Back wall portion 54 Connecting wall portion 56 Connecting portion 58 Screw hole 60 Bracket main body 62 Stopper top wall portion 64 Connecting plate portion 66 Mass adjustment portion 68 Connecting piece 70 Bolt hole 72 Bolt 74 Cushion rubber 76 Power unit 78 Subframe (vibration isolation target)

Claims

1. A vibration-damping device with a bracket in which a bracket is attached to a vibration-damping device, the bracket comprising: a mounting portion to which the vibration-damping device is attached; a mounting leg portion formed integrally with the mounting portion and extending out on one side; a stopper vertical wall portion formed integrally with the mounting portion and protruding out on the other side; and a stopper top wall portion attached to the protruding end of the stopper vertical wall portion, the stopper top wall portion being formed separately from a material with a higher specific gravity than the mounting portion.

2. A bracket-attached vibration-damping device as described in claim 1, wherein the mounting portion of the bracket is composed of a cylindrical press-fitted cylindrical portion, the vibration-damping device is attached to the bracket by being press-fitted and fixed into the press-fitted cylindrical portion through a pair of opposing wall portions provided on the stopper vertical wall portion, and an opening in the press-fitted cylindrical portion on the side opposite the stopper top wall portion is provided with a stopper portion that protrudes inward and prevents the vibration-damping device from coming off to the side opposite the stopper top wall portion.

3. A vibration-damping device with a bracket as described in claim 1 or 2, wherein the stopper top wall portion is integrally provided with a connecting plate portion attached across a pair of opposing wall portions of the stopper vertical wall portion, and a mass adjustment portion that protrudes partially from the connecting plate portion and adjusts the mass of the stopper top wall portion.

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