Vibration isolator

Abstract

To provide a vibration isolator having a novel structure which can further improve the durability of cushion rubber constituting a stopper mechanism.SOLUTION: In a vibration isolator 10, a first attachment member 18 and a second attachment member 20 are connected to each other by a main body rubber elastic body 22, and stopper mechanisms for limiting a deformation amount of the main body rubber elastic body 22 as buffers by abutting on each other via cushion rubber 56 in opposing regions 40, 90 at the first attachment member 18 side and the second attachment member 20 side are arranged. A recess 44 having a peripheral wall 48 is partially formed at an abutment face 40 of the first attachment member 18 side on which the cushion rubber 56 is superimposed with respect to the second attachment member 20 side, a protrusion 60 which intrudes into the recess 44 in a non-adhesion manner is formed at the cushion rubber 56, and a clearance 66 is set between an inner face 46 (48) of the recess 44 and an outer face 62 (64) of the protrusion 60.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an anti-vibration device for use in, for example, an engine mount of an automobile. [Background technology]

[0002] Conventionally, there have been known vibration-damping devices used in engine mounts for automobiles, etc. As disclosed in, for example, JP 2020-023790 A (Patent Document 1), the vibration-damping device has a vibration-damping device main body in which an inner member and an outer cylindrical member are connected by a main rubber elastic body, and the outer cylindrical member is inserted into and assembled to a cylindrical portion of an outer bracket. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-023790 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the vibration isolation device described in Patent Document 1 has an inner bracket attached to an inner member that protrudes laterally, and a shock-absorbing member attached to the inner bracket. The inner bracket and the outer bracket come into contact with each other via the shock-absorbing member, forming a bound stopper that limits the amount of deformation of the main rubber elastic body.

[0005] The cushioning material constituting the bound stopper is sandwiched between the inner bracket and the outer bracket and strongly compressed, and therefore is required to have high durability. However, the inventors conducted research and experiments and found that in the cushioning material of Patent Document 1, in which the portion constituting the bound stopper is a plate of approximately uniform thickness, large localized distortion occurs, particularly near the center. This made it clear that there is room for further improvement in durability in the portion constituting the bound stopper in the cushioning material of Patent Document 1.

[0006] An object of the present invention is to provide a vibration-isolating device with a novel structure that can further improve the durability of the shock-absorbing rubber that constitutes the stopper mechanism. [Means for solving the problem]

[0007] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely illustrative and may be combined with one another as appropriate, and the multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0008] The first aspect is a vibration-damping device in which a first mounting member and a second mounting member are connected by a main rubber elastic body, and a stopper mechanism is provided which cushions and limits the amount of deformation of the main rubber elastic body by abutting against each other via a cushion rubber at opposing portions of the first mounting member side and the second mounting member side, in which a recess with a peripheral wall is partially formed on the abutment surface of the first mounting member side, on which the cushion rubber is superimposed and attached, against the second mounting member side, and a convex portion is formed in the cushion rubber which fits into the recess without being adhered, and a gap is set between the inner surface of the recess and the outer surface of the convex portion.

[0009] According to the vibration isolation device constructed according to this embodiment, the thickness dimension in the compression direction of the cushion rubber in the stopper mechanism is made larger at the portion where the convex portion is formed, and when the cushion rubber is compressed between the first mounting member side and the second mounting member side, the compression rate of the cushion rubber is reduced at the portion where the convex portion is formed, improving the durability of the cushion rubber. Therefore, by providing the convex portion at the portion where the cushion rubber is likely to become highly distorted, the durability is improved by distributing the distortion.

[0010] The convex portion of the cushioning rubber fits into the concave portion provided on the first mounting member side to which the cushioning rubber is attached, thereby preventing changes in the stroke of the stopper mechanism and an increase in weight due to the formation of the convex portion. In addition, the convex portion and the concave portion are provided partially, and the change in the spring characteristics of the stopper mechanism is suppressed by the portion outside the convex portion where distortion of the cushioning rubber is less likely to be a problem.

[0011] Since the protrusion fits into the recess without being bonded and a gap is provided between the outer surface of the protrusion and the inner surface of the recess, when the cushion rubber comes into contact with the second mounting member and is compressed and deformed, the protrusion is not immediately restrained by the inner surface of the recess, and the gap allows the protrusion to deform. Therefore, when a relatively small stopper load is input, the shock caused by the sudden increase in springiness of the protrusion is reduced.

[0012] Moreover, since the recess has a peripheral wall, and the peripheral wall of the recess limits the amount of deformation of the protrusion that fits into the recess in the direction perpendicular to the compression direction when compressed, when the compression deformation of the cushion rubber increases due to the input of the stopper load, the deformation of the protrusion is restricted by the inner surface of the recess, and the spring characteristics of the cushion rubber become harder. This makes it possible to obtain a strong stopper effect that restricts the relative displacement between the first mounting member side and the second mounting member side when a large load is input.

[0013] In a second aspect, in the vibration-proof device according to the first aspect, the gap is provided between an inner circumferential surface of the recess and an outer circumferential surface of the protrusion.

[0014] According to the vibration-proof device constructed according to this embodiment, a gap is provided on the outer periphery perpendicular to the compression direction of the protrusion, which allows, for example, the protrusion to bulge toward the outer periphery due to the compression deformation in the protruding direction of the protrusion. This prevents the compression spring constant in the protruding direction of the protrusion from increasing suddenly with a small amount of compression deformation, providing a cushioning stopper effect. Also, the protrusion can be easily inserted into the recess.

[0015] A third aspect is the vibration-proof device according to the first or second aspect, wherein the gap is provided between the protruding tip surface of the convex portion and the bottom surface of the concave portion.

[0016] According to the vibration-isolating device constructed according to this embodiment, when a relatively small stopper load is applied to the buffer rubber such that the protruding tip surface of the convex does not come into contact with the bottom surface of the concave, the buffer rubber is not compressed in the portion where the convex is formed, and distortion in the portion where the convex is formed is effectively reduced. On the other hand, when a large stopper load is applied to the buffer rubber such that the protruding tip surface of the convex comes into contact with the bottom surface of the concave, the buffer rubber is compressed even in the portion where the convex is formed, so that the spring characteristics of the buffer rubber become harder and a stronger stopper effect is exerted.

[0017] A fourth aspect is an anti-vibration device described in any one of the first to third aspects, wherein in the stopper mechanism, the recess and the convex portion of the cushioning rubber that fits into the recess are provided at multiple locations spaced apart from each other.

[0018] According to the vibration-isolating device constructed according to this embodiment, when there are multiple locations in the cushion rubber where distortion is likely to concentrate, by providing a pair of a convex portion of the cushion rubber and a concave portion into which the convex portion fits at each of the multiple locations, it is possible to more effectively reduce or eliminate localized distortion concentration in the cushion rubber. Also, compared to a case in which large-area convex portions and concave portions are provided so as to collectively cover multiple distortion concentration areas, since peripheral walls of the concave portions are provided on the outer periphery of each convex portion, it is easier to adjust the spring characteristics of the cushion rubber and the stopper action when a large load is input.

[0019] A fifth aspect is an anti-vibration device described in any one of the first to fourth aspects, wherein the gap set in the stopper mechanism between the inner surface of the recess and the outer surface of the convex portion is configured to disappear when a stopper load is input.

[0020] With an anti-vibration device constructed in accordance with this embodiment, when a stopper load is input, deformation of the convex portion is not permitted by a gap but is restrained by the inner surface of the concave portion, thereby making it possible to more effectively obtain the desired stopper effect.

[0021] In a sixth aspect, in the vibration-proof device according to any one of the first to fifth aspects, an air vent passage is provided in the peripheral wall of the recess in the stopper mechanism.

[0022] With an anti-vibration device constructed according to this aspect, when the convex portion that has entered the recess portion deforms to fill the gap, the air that was in the gap is discharged to the outside through the air vent passage, preventing the air spring action caused by sealing the gap and abnormal noise caused by air leaking. Furthermore, even if there is no gap between the outer circumferential surface of the convex portion and the inner surface of the peripheral wall of the recess portion, for example, it becomes difficult for the air spring to act between the tip surface of the convex portion and the bottom surface of the recess portion, making it easier to insert the convex portion into the recess portion. Effect of the Invention

[0023] According to the present invention, it is possible to further improve the durability of the shock-absorbing rubber that constitutes the stopper mechanism in the vibration isolation device. [Brief description of the drawings]

[0024] [Figure 1] FIG. 3 is a cross-sectional view showing an engine mount according to a first embodiment of the present invention, which corresponds to cross-section II of FIG. [Diagram 2] Plan view of the engine mount shown in Figure 1 [Diagram 3] III-III cross section of Figure 2 [Figure 4] IV-IV cross section of Figure 2 [Diagram 5] An exploded perspective view of the engine mount shown in FIG. [Figure 6] FIG. 2 is a perspective view of a first bracket constituting the engine mount shown in FIG. 1; [Figure 7] FIG. 2 is a perspective view of a stopper rubber that constitutes the engine mount shown in FIG. 1. [Figure 8] 8 is a bottom view showing a state in which the stopper rubber of FIG. 7 is attached to the first bracket of FIG. 6. [Figure 9] FIG. 2 is a perspective view of a second bracket constituting the engine mount shown in FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0026] 1 to 4 show an engine mount 10 for an automobile as a first embodiment of a vibration-damping device according to the present invention. As shown in Fig. 5, 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. The mount body 12 has a structure in which a first mounting member 18 and a second mounting member 20 are connected by a main rubber elastic body 22. In the following description, in principle, the up-down direction refers to the up-down direction in Fig. 1, which is the mount central axial direction, the left-right direction refers to the left-right direction in Fig. 1, and the front-rear direction refers to the up-down direction in Fig. 2.

[0027] 1, the first mounting member 18 is in the form of a small-diameter, generally circular block, and is a highly rigid member made of metal such as iron or aluminum alloy, or fiber-reinforced synthetic resin. A bottomed screw hole 24 that opens to the upper surface is formed in the first mounting member 18. A flange-shaped portion 26 that protrudes to the outer periphery is integrally provided at the upper end of the first mounting member 18. The flange-shaped portion 26 in this embodiment has an outer shape that is generally octagonal when viewed in the axial direction, but the outer shape when viewed in the axial direction may be, for example, circular or rectangular.

[0028] The second mounting member 20 has a thin-walled, large-diameter, generally cylindrical shape, and is a highly rigid member made of the same material as the first mounting member 18. The second mounting member 20 in this embodiment has a stepped cylindrical shape with an upper portion having a larger diameter than a lower portion, but may also be, for example, a cylindrical shape with a generally constant diameter over the entire axial length.

[0029] The first mounting member 18 and the second mounting member 20 are arranged on approximately the same central axis, the lower part of the first mounting member 18 is inserted into the upper opening of the second mounting member 20, and are connected to each other by the main rubber elastic body 22. The main rubber elastic body 22 is formed in an approximately truncated cone shape with a diameter that decreases upward, and the first mounting member 18 is fixed to the upper part, which is the end on the small diameter side, and the second mounting member 20 is fixed to the outer circumferential surface of the lower part, which is the end on the large diameter side. In this embodiment, the main rubber elastic body 22 is formed as an integrally vulcanized molded product including the first mounting member 18 and the second mounting member 20. The lower surface of the main rubber elastic body 22 is formed as an inverted mortar-shaped concave surface 28 that expands toward the outer circumferential side toward the downward direction. A covering rubber 30 that covers the inner circumferential surface is fixed to the lower part of the second mounting member 20, which has a small diameter, and the covering rubber 30 is formed integrally with the main rubber elastic body 22.

[0030] In the mount body 12 constructed as described above, the first bracket 14 is attached to the first mounting member 18, and the second bracket 16 is attached to the second mounting member 20. The first bracket 14 and the second bracket 16 may be formed from different materials, but both are made to be highly rigid members that are unlikely to deform due to external forces, and for example, metals such as iron or aluminum alloy, and fiber-reinforced synthetic resins are suitably used as the forming materials.

[0031] The first bracket 14 is in the shape of a thick plate or block, and is long in the left-right direction, with the left end being thicker in the up-down direction and wider in the front-to-rear direction than the right end. A connecting hole 32 is formed in the right end of the first bracket 14, penetrating in the up-down direction. The connecting hole 32 has a larger diameter at the top than at the bottom, so that the head of a connecting bolt 68, which will be described later, is accommodated in the larger-diameter upper part. Two first mounting holes 34, 34 penetrating in the up-down direction are provided in the left end of the first bracket 14, side by side and spaced apart from each other in the front-to-rear direction.

[0032] As shown in FIG. 6, the lower surface of the first bracket 14 includes a base end connection surface 36 at the right end, a tip attachment surface 38 at the left end, and an intermediate stopper surface 40 as an abutment surface located between the base end connection surface 36 and the tip attachment surface 38. The base end connection surface 36, the tip attachment surface 38, and the intermediate stopper surface 40 are all flat surfaces that extend substantially perpendicular to the up-down direction, and the tip attachment surface 38 is located below the intermediate stopper surface 40, which is located below the base end connection surface 36. The base end connection surface 36, the tip attachment surface 38, and the intermediate stopper surface 40 are located apart from each other in the left-right direction, and are continuous between them by an inclined surface. The base end connection surface 36 has a connection hole 32 opening therein, and the periphery of the connection hole 32 is an annular seat surface 42 that protrudes downward. The tip attachment surface 38 also has a first attachment hole 34 opening therein.

[0033] Two recesses 44, 44 are open in the intermediate stopper surface 40. The recess 44 in this embodiment is a generally rounded rectangular recess longer in the front-rear direction than in the left-right direction, and its inner surface is formed by a flat bottom surface 46 extending in a direction perpendicular to the up-down direction, and a peripheral wall 48 having a cylindrical or annular inner peripheral surface protruding downward on the outer periphery side of the bottom surface 46. The two recesses 44, 44 are provided at two locations separated from each other in the front-rear direction, and are arranged side by side in the front-rear direction at approximately the same position in the left-right direction. The total opening area of ​​the two recesses 44, 44 is preferably half or less of the area of ​​the intermediate stopper surface 40, more preferably 1 / 3 or less. The depth dimension of the recess 44 is smaller than the width dimension of the recess 44 in the left-right direction, which is the short side direction, and more preferably 1 / 5 or less of the width dimension of the recess 44.

[0034] 3 and 4, a stopper rubber 50 is attached to the first bracket 14. The stopper rubber 50 is made of a rubber elastic body, and as shown in Fig. 7, is integrally provided with an upper buffer part 52 that extends substantially perpendicular to the up-down direction, side buffer parts 54 that extend downward from both the front and rear ends and the right end of the upper buffer part 52, and a lower buffer part 56 as a buffer rubber that connects the lower ends of the left end portions of the side buffer part 54 together.

[0035] The upper buffer part 52 has a generally flat plate shape, with its left end portion having a linear edge shape extending in the front-rear direction and its right end portion having a generally semicircular edge shape. A circular through-hole 58 is formed in the upper buffer part 52, penetrating it in the up-down direction. The shape of the upper buffer part 52 corresponds to the shape of the right end part of the first bracket 14 when viewed in the up-down direction.

[0036] The side buffer portion 54 has a shape corresponding to both front and rear ends and the right end of the upper buffer portion 52, and in this embodiment, is substantially U-shaped when viewed in the vertical direction. The side buffer portion 54 extends downward from the upper buffer portion 52 with a substantially constant cross-sectional shape. The left end portion of the side buffer portion 54 protrudes leftward from the upper buffer portion 52, and is shaped to correspond to the front and rear side surfaces of the middle portion of the first bracket 14 (the portion where the middle stopper surface 40 is provided). In this embodiment, the left end portion of the side buffer portion 54 has one end located on the front side that is substantially flat, and the other end located on the rear side has a tapered portion that is inclined backward, and is expanded toward the left. The vertical length dimension of the side buffer portion 54 is shortened at the right end portion.

[0037] The lower buffer section 56 has a generally flat plate shape that spreads generally perpendicular to the upward direction, and is provided at a position offset to the left of the upper buffer section 52. The left end of the lower buffer section 56 reaches the same left-right position as the left end of the side buffer section 54, and has a linear shape that extends in the front-rear direction. The right end of the lower buffer section 56 has a curved shape that is concave toward the right at the front, and is integrally connected to the side buffer section 54 at the rear.

[0038] Two protrusions 60, 60 are integrally formed in the lower buffer portion 56. The protrusion 60 is a flattened, approximately rectangular parallelepiped protrusion that has a shape that corresponds to the recess 44 of the first bracket 14 and has an outer dimension that is one size smaller. In the present embodiment, the protrusion 60 is longer in the front-rear direction than in the left-right direction when viewed in the up-down direction. The outer surface of the protrusion 60 is composed of a protruding tip surface 62 that spreads approximately perpendicular to the up-down direction and a cylindrical or annular outer peripheral surface 64. The two protrusions 60, 60 are provided at two locations separated from each other in the front-rear direction and are arranged side by side in the front-rear direction at approximately the same position in the left-right direction.

[0039] In this embodiment, the height dimension of the convex portion 60 in the up-down direction is smaller than the depth dimension of the concave portion 44 in the up-down direction, the width dimension of the convex portion 60 in the left-right direction is smaller than the width dimension of the concave portion 44 in the left-right direction, and the length dimension of the convex portion 60 in the front-rear direction is smaller than the width dimension of the concave portion 44 in the front-rear direction. The protruding height dimension of the convex portion 60 is preferably set within a range of 50% to 80% of the depth dimension of the concave portion 44. The protruding height dimension of the convex portion 60 is preferably set within a range of 3 to 30% of the thickness dimension of the lower buffer portion 56, and more preferably within a range of 5 to 10%. It is desirable that the rubber volume of the convex portion 60 is set within a range of 10 to 60% of the rubber volume of the lower buffer portion 56. The difference between the outer dimension of the convex portion 60 and the inner dimension of the concave portion 44 may be constant or different in each direction.

[0040] The stopper rubber 50 thus constructed is attached to the outer surface of the first bracket 14, as shown in Fig. 8. That is, the upper buffer portion 52 of the stopper rubber 50 is superimposed on the upper surface of the right end portion of the first bracket 14, the side buffer portion 54 of the stopper rubber 50 is superimposed on the front and rear side surfaces of the right end portion and the middle portion of the first bracket 14, and further, the lower buffer portion 56 of the stopper rubber 50 is superimposed on the middle stopper surface 40 of the first bracket 14. As a result, the stopper rubber 50 is attached in an externally inserted state to the first bracket 14. Note that the relative displacement of the stopper rubber 50 in the left-right direction with respect to the first bracket 14 is limited by the fact that the first bracket 14 widens in the front-rear direction toward the left, the side buffer portion 54 of the stopper rubber 50 is superimposed on the widened portion of the first bracket 14 from the right, and the side buffer portion 54 of the stopper rubber 50 is superimposed on the right side surface of the first bracket 14. Furthermore, the first bracket 14 to which the stopper rubber 50 is attached has a base end coupling surface 36, which is the lower surface of the right end portion, exposed downward to the right of the lower buffer portion 56 of the stopper rubber 50 without being covered by the stopper rubber 50. In this embodiment, the stopper rubber 50 is attached to the first bracket 14 without being bonded, but it is sufficient that the stopper rubber 50 and the first bracket 14 are not bonded between the convex portions 60, 60 and the concave portions 44, 44 described below, and for example, the buffer portions 52, 54, 56 may be bonded to the first bracket 14.

[0041] The protrusions 60, 60 provided on the lower buffer portion 56 of the stopper rubber 50 are inserted in the recesses 44, 44 opening on the intermediate stopper surface 40 of the first bracket 14 without being bonded. Since the outer dimension of the protrusion 60 is larger than the inner dimension of the recess 44, as shown in Figs. 3 and 4, a gap 66 is provided between the inner surface of the recess 44 and the outer surface of the protrusion 60. In this embodiment, the protruding tip surface 62 of the protrusion 60 faces the bottom surface 46 of the recess 44 while being spaced apart in the vertical direction, and the outer peripheral surface 64 of the protrusion 60 faces the inner peripheral surface of the peripheral wall 48 of the recess 44 while being spaced apart toward the inner peripheral side (inward in the front-rear and left-right facing direction). Therefore, the gap 66 is provided continuously between the inner peripheral surface of the recess 44 and the outer peripheral surface 64 of the protrusion 60, and between the bottom surface 46 of the recess 44 and the protruding tip surface 62 of the protrusion 60.

[0042] The size of the gap 66 formed between the convex portion 60 of the stopper rubber 50 and the concave portion 44 of the first bracket 14 is preferably set in consideration of the magnitude of the stopper load acting on the lower buffer portion 56 so that the gap 66 disappears due to elastic deformation of the lower buffer portion 56 and the convex portion 60 when a stopper load is input to the lower buffer portion 56 described later. The volume of the gap 66 is preferably set within a range of 1 to 20% of the volume of the concave portion 44, and more preferably within a range of 3 to 10%. The disappearance of the gap 66 may occur, for example, when the relative displacement amount of the first and second mounting members 18 and 20 is at the maximum allowable value or when the maximum stopper load assumed in design is input.

[0043] The first bracket 14, with the stopper rubber 50 attached, has a seat surface 42 provided on the base end connecting surface 36 at the right end portion thereof in abutting contact with the upper surface of the first mounting member 18 of the mount body 12, and the connecting bolt 68 inserted into the connecting hole 32 of the first bracket 14 is screwed into the screw hole 24 of the first mounting member 18, thereby fixing the first bracket 14 to the first mounting member 18.

[0044] The second bracket 16 is a highly rigid member made of the same material as the first bracket 14, and includes a cylindrical portion 70 as shown in Fig. 9. A cover portion 72 is attached to the upper end of the cylindrical portion 70 by means of welding or the like.

[0045] The cover portion 72 is integrally provided with a pair of side walls 74, 74 facing each other in the front-rear direction, an upper bottom wall portion 76 connecting the side walls 74, 74 at their upper ends, and a right wall portion 78 connecting the pair of side walls 74, 74 and the upper bottom wall portion 76 at their right ends, and opens downward and to the left. An insertion hole 80 penetrating in the vertical direction is formed in the upper bottom wall portion 76 of the cover portion 72. The pair of side walls 74, 74 and the upper bottom wall portion 76 of the cover portion 72 are bent outward at their left ends with respect to the left opening, thereby improving the deformation rigidity of the cover portion 72.

[0046] A pair of mounting legs 82, 82 extending downward are disposed on each of the front and rear sides of the cylindrical portion 70. The mounting leg 82 includes a plate-like fastening piece 84 extending in the vertical direction, and a mounting piece 86 that bends and extends outward in the front and rear directions at the lower end of the fastening piece 84. The fastening piece 84 is shaped like a curved plate extending in the vertical direction with a cross-sectional shape that is curved in the circumferential direction along the outer circumferential surface of the cylindrical portion 70. The mounting piece 86 is shaped like a flat plate that extends perpendicular to the vertical direction, and has a second mounting hole 88 that penetrates in the vertical direction.

[0047] A stopper receiving portion 90 is fixed to the upper end of the cylindrical portion 70 by means of welding or the like. The stopper receiving portion 90 is generally shaped like a rectangular plate with the longitudinal direction being the long direction, and is wide in a direction perpendicular to the vertical direction. A notch 92 that opens to the right is formed in the central portion of the stopper receiving portion 90 in the longitudinal direction. The notch 92 has an inner surface shape that is curved in the circumferential direction along the upper opening of the cylindrical portion 70, and the opening portion of the notch 92 protrudes from the upper opening of the cylindrical portion 70 to the inner periphery. In short, the stopper receiving portion 90 is overlapped and fixed to the upper surface of the cylindrical portion 70, and protrudes outward on both the left and right sides from the upper surface of the cylindrical portion 70.

[0048] The second bracket 16 is fixed to the second mounting member 20 of the mount main body 12 by press-fitting the second mounting member 20 into the cylindrical portion 70 from below. When the first bracket 14 and the second bracket 16 are attached to the mount main body 12, the second bracket 16 is first fixed to the second mounting member 20, and then the first bracket 14 is inserted in the left-right direction from the left opening of the cover portion 72 of the second bracket 16 to be fixed to the first mounting member 18. At this time, since an insertion hole 80 is formed in the upper bottom wall portion 76 of the cover portion 72 and a through hole 58 is also formed in the upper buffer portion 52 of the stopper rubber 50, the connecting bolt 68 can be inserted from above through the insertion hole 80 and the through hole 58 into the screw hole 24 of the first mounting member 18 and screwed.

[0049] The engine mount 10 is attached to a vehicle and connects a power unit (not shown) and the vehicle body in a vibration-proof manner. That is, the first bracket 14 on the first mounting member 18 side is attached to the power unit (not shown) by a first mounting bolt (not shown) inserted into the first mounting hole 34, and the second bracket 16 on the second mounting member 20 side is attached to the vehicle body (not shown) by a second mounting bolt (not shown) inserted into the second mounting hole 88 of the mounting piece 86. Note that the first mounting member 18 side may be attached to the vehicle body, and the second mounting member 20 side may be attached to the power unit.

[0050] When vibrations are input between the first mounting member 18 attached to the power unit and the second mounting member 20 attached to the vehicle body, the desired vibration-proofing effect is achieved based on the vibration-damping and vibration-insulating effects caused by the elastic deformation of the main rubber elastic body 22. The main direction of vibration input to the engine mount 10 is the vertical direction.

[0051] The engine mount 10 is provided with a stopper mechanism that limits the amount of relative displacement between the first mounting member 18 side and the second mounting member 20 side. That is, the intermediate stopper surface 40 of the first bracket 14 and the stopper receiving portion 90 of the second bracket 16 face each other in the vertical direction at a predetermined distance, and a bound stopper is formed as a stopper mechanism that prevents excessive relative displacement between the first mounting member 18 side and the second mounting member 20 side in the vertical approach direction by abutting against each other, thereby limiting the amount of elastic deformation of the main rubber elastic body 22. In this embodiment, the opposing portion between the first mounting member 18 side and the second mounting member 20 side is formed by an intermediate portion of the first bracket 14 that has the intermediate stopper surface 40, and the stopper receiving portion 90 of the second bracket 16.

[0052] The lower buffer portion 56 of the stopper rubber 50 is disposed between the opposing surfaces of the intermediate stopper surface 40 of the first bracket 14 and the stopper receiving portion 90 of the second bracket 16. In the bound stopper, the intermediate stopper surface 40 and the stopper receiving portion 90 come into contact with each other via the lower buffer portion 56. As a result, the stopper action of the bound stopper, which limits the amount of elastic deformation of the main rubber elastic body 22, is cushioned by the lower buffer portion 56. The lower surface of the lower buffer portion 56 and the upper surface of the stopper receiving portion 90, which come into contact with each other in the stopper mechanism, are preferably shaped to approximately correspond to each other, and in this embodiment, are flat surfaces that extend approximately perpendicular to the up-down direction. The lower surface of the lower buffer portion 56 may be provided with embossing or minute irregularities, which can reduce the impact sound when the lower buffer portion 56 and the stopper receiving portion 90 come into contact with each other and prevent the lower buffer portion 56 from sticking to the stopper receiving portion 90.

[0053] In the bound stopper, the lower buffer portion 56 of the stopper rubber 50 is sandwiched between the intermediate stopper surface 40 of the first bracket 14 and the stopper receiving portion 90 of the second bracket 16 in the vertical direction and compressed. The lower buffer portion 56 in this embodiment has protruding portions 60, 60 protruding upward, and each protruding portion 60 is partially thickened in the vertical direction at the forming portion. As a result, in the forming portion of the protruding portion 60 where the lower buffer portion 56 is compressed in the vertical direction, the distortion due to the compression in the vertical direction of the lower buffer portion 56 is reduced, thereby improving the durability of the lower buffer portion 56. The protruding portion 60 is provided in a portion where the distortion in the lower buffer portion 56 is high when the lower buffer portion 56 is sandwiched between the intermediate stopper surface 40 and the stopper receiving portion 90 and compressed, thereby realizing improvement in durability by dispersing the distortion.

[0054] The lower buffer portion 56 of the stopper rubber 50 is overlapped with the intermediate stopper surface 40 of the first bracket 14, and each convex portion 60 of the lower buffer portion 56 fits into a concave portion 44 that opens into the intermediate stopper surface 40. A gap 66 is provided between the outer surface of the convex portion 60 and the inner surface of the concave portion 44. As a result, when the lower buffer portion 56 is compressed between the intermediate stopper surface 40 and the stopper receiving portion 90, the outer surface of the convex portion 60 is unlikely to be restrained by the inner surface of the concave portion 44 when the amount of compressive deformation of the lower buffer portion 56 is small.

[0055] In other words, when the stopper load input to the lower buffer portion 56 is small and the bottom surface 46 of the recess 44 and the protruding tip surface 62 of the protrusion 60 are not in contact with each other, the portion of the lower buffer portion 56 where the protrusion 60 is formed is hardly compressed, and compressive strain is effectively suppressed.

[0056] In addition, when the bottom surface 46 of the recess 44 and the protruding tip surface 62 of the protruding portion 60 come into contact with each other, the protruding portion 60 is compressed in the protruding direction, and a compressive strain is also generated in the portion of the lower buffer portion 56 where the protruding portion 60 is formed. The outer peripheral surface 64 of the protruding portion 60 is separated from the peripheral wall 48 of the recess 44 by a gap 66, and is not restrained by the inner peripheral surface of the recess 44. As a result, the protruding portion 60 is allowed to bulge outwardly due to compression in the protruding direction, and the compression spring constant of the protruding portion 60 in the protruding direction is relatively small, and a buffering stopper action is realized in the bound stopper. Therefore, improvement of ride comfort by preventing shock feeling in the vehicle is realized.

[0057] Furthermore, when the stopper load input to the lower buffer portion 56 is large and the deformation of the lower buffer portion 56 and the protruding portions 60, 60 increases to the point where the gap 66 disappears, the deformation of the protruding portion 60 is restrained by the inner surface of the recess 44, so that the spring constant of the protruding portion 60 becomes significantly large. As a result, the bound stopper exhibits an excellent displacement restriction effect due to its hard spring characteristics, and can effectively limit the amount of relative displacement between the first mounting member 18 side and the second mounting member 20 side. This more reliably avoids excessive deformation of the main rubber elastic body 22, improving the durability of the engine mount 10, and also limiting the relative displacement of the power unit with respect to the vehicle body, thereby improving the vehicle's driving performance.

[0058] As described above, in the stopper mechanism of engine mount 10, convex portion 60 fits into concave portion 44 with gap 66 therebetween, thereby improving durability by mitigating stress concentration and providing a cushioning displacement restriction effect in the region where the stopper load acting on lower buffer portion 56 is relatively small. On the other hand, in the stopper mechanism of engine mount 10, convex portion 60 is surrounded by a continuous inner circumferential surface substantially all around by peripheral wall 48 of concave portion 44, so that in the region where the stopper load acting on lower buffer portion 56 is relatively large, deformation of convex portion 60 is restricted, providing a stronger displacement restriction effect.

[0059] When the engine mount 10 is installed on the vehicle, the shared support load of the power unit is input downward to the first mounting member 18, so that the first mounting member 18 and the first bracket 14 are displaced downward from the state shown in Fig. 1. As a result, the upper buffer portion 52 of the stopper rubber 50 covering the upper surface of the first bracket 14 and the upper bottom wall portion 76 of the cover portion 72 of the second bracket 16 are separated from each other in the vertical direction. Then, the upper surface of the first bracket 14 and the upper bottom wall portion 76 of the cover portion 72 of the second bracket 16 come into contact with each other via the upper buffer portion 52 of the stopper rubber 50, thereby forming a rebound stopper that limits the amount of upward relative displacement of the first mounting member 18 side with respect to the second mounting member 20 side.

[0060] In addition, the first bracket 14 and the front and rear side wall portions 74, 74 of the second bracket 16 abut against each other via the lateral buffer portions 54 of the stopper rubber 50, thereby forming front and rear stoppers that limit the amount of relative displacement in the fore-and-aft direction between the first mounting member 18 side and the second mounting member 20 side.

[0061] In addition, the first bracket 14 and the right wall portion 78 of the second bracket 16 abut against each other via the lateral buffer portion 54 of the stopper rubber 50, thereby forming a right stopper that limits the amount of relative displacement of the first mounting member 18 to the second mounting member 20.

[0062] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the specific description. For example, the recessed portion 44 and the protruding portion 60 may be provided at one location each, or at three or more locations each.

[0063] The shape of the protrusion 60 as viewed in the axial direction is not limited to the rounded rectangular shape shown in the above embodiment, and various shapes may be adopted, such as a circle including an ellipse or an oval, a polygon, an irregular shape, etc. In addition, the shape and size of the cross section of the protrusion 60 may change in the protruding direction, and for example, by making the protrusion 60 into a tapered shape that becomes smaller in diameter toward the protruding tip, it is possible to facilitate insertion into the recess and also to set a nonlinear spring characteristic according to the magnitude of the stopper load acting on the protrusion.

[0064] The recesses, like the protrusions, are not limited to the shapes of the above-described embodiments. The recesses are preferably shaped to correspond to the protrusions as shown in the above-described embodiments, but may be shaped differently from the protrusions. That is, the inner circumferential surface of the recesses and the outer circumferential surface of the protrusions may be shaped differently from each other in at least one of the longitudinal section and the transverse section.

[0065] In the above embodiment, when the protrusion 60 is inserted into the recess 44, the outer peripheral surface 64 of the protrusion 60 is separated from the inner peripheral surface of the peripheral wall 48 of the recess 44, and the protruding tip surface 62 of the protrusion 60 is separated from the bottom surface 46 of the recess 44, and a gap 66 is provided between both of them, but the gap may be provided at least partially between the outer surface of the protrusion and the inner surface of the recess. Specifically, for example, a gap may be provided only between the outer peripheral surface 64 of the protrusion 60 and the inner peripheral surface of the peripheral wall 48 of the recess 44, and the protruding tip surface 62 of the protrusion 60 and the bottom surface 46 of the recess 44 may be in contact with each other, or a gap may be provided only between the protruding tip surface 62 of the protrusion 60 and the bottom surface 46 of the recess 44, and the outer peripheral surface 64 of the protrusion 60 and the inner peripheral surface of the peripheral wall 48 of the recess 44 may be in contact with each other. In addition, the gap between the opposing outer peripheral surface 64 of the convex portion 60 and the inner peripheral surface of the peripheral wall 48 of the concave portion 44, and the gap between the opposing protruding tip surface 62 of the convex portion 60 and the bottom surface 46 of the concave portion 44 may be continuous as in the above embodiment, or may be independent of each other.

[0066] When a gap is formed between the inner peripheral surface of the recess and the outer peripheral surface of the protrusion, the gap may be partially provided in the circumferential direction. Specifically, for example, a protrusion with an elliptical cross section may enter a recess with a circular cross section, and the outer peripheral surface of the protrusion may abut against the inner peripheral surface of the recess in the major axis direction and be separated in the minor axis direction to form two gaps separated from each other in the circumferential direction on both sides in the minor axis direction. It is also possible to set a gap between the protrusions that enter the recess by configuring the protrusions as a plurality of protrusions that are substantially separated from each other.

[0067] Also, a gap can be partially set in the depth direction of the recess, in other words, in the protruding direction of the protrusion. Specifically, for example, a protrusion having a protruding tip portion with a smaller diameter than the base end portion may be used, so that a gap is set between the outer circumferential surface of the protruding tip portion of the protrusion and the inner circumferential surface of the recess, and the outer circumferential surface of the base end portion of the protrusion and the outer circumferential surface of the recess come into contact with each other without a gap.

[0068] Also, a partial gap can be set between the opposing surfaces of the bottom surface and the protruding tip surface by providing a step or a partial recess on at least one of the bottom surface of the recess and the protruding tip surface of the protruding part. Also, by setting a gap extending in the circumferential direction between the inner peripheral surface of the recess and the outer peripheral surface of the protruding part, the assembly work of inserting the protruding part into the recess becomes easier. On the other hand, by bringing the inner peripheral surface of the recess and the outer peripheral surface of the protruding part into contact with each other, it is also possible to obtain a positioning effect of the stopper rubber by engaging or fitting the recess and the protruding part when assembling the stopper rubber.

[0069] An air vent passage may be formed in the peripheral wall 48 of the recess 44 in the above embodiment. The air vent passage is a passage that connects the gap 66 between the protrusion 60 and the recess 44 to an external space, and is formed, for example, in a groove shape that opens to the intermediate stopper surface 40 in a component part of the peripheral wall 48 of the first bracket 14. One end of this groove is connected to the recess 44, and the other end is connected to the external space at a position on the intermediate stopper surface 40 that is separated from the lower buffer portion 56. By providing such an air vent passage, in the process in which the lower buffer portion 56 is compressed and the gap 66 disappears, the air in the gap 66 is discharged to the outside through the air vent passage, so that the action of the air spring is avoided and the generation of abnormal noise due to air leakage can also be prevented.

[0070] The air vent passage may be formed on the stopper rubber 50 side, but is preferably formed on the peripheral wall 48 as described above, which is advantageous for ensuring the volume and durability of the stopper rubber 50 and ensures a stable air vent passage even when the stopper rubber 50 is elastically deformed due to the input of the stopper load. It is more preferable that the air vent passage is not blocked even when the stopper rubber 50 is elastically deformed due to the input of the stopper load, and it is desirable that the air vent passage has a depth etc. that is sufficient to prevent the air vent passage from being completely filled even if the stopper rubber 50 elastically deformed by the stopper load enters the air vent passage. The air vent passage may be in the form of a recessed groove or a tunnel, and there are no limitations on the position, number, size, shape etc.

[0071] For example, grains or minute irregularities may be formed on the surface of the protrusion 60. This makes it possible to reduce or prevent the generation of abnormal noise when the protrusion 60, which is separated from the inner surface of the recess 44 via the gap 66, comes into contact with the inner surface of the recess 44.

[0072] The cushion rubber does not necessarily have to be configured as a stopper rubber 50 separate from the main rubber elastic body 22, and may be formed integrally with the main rubber elastic body, for example, as in the lower cushion rubber layer shown in Figure 26 of Japanese Patent No. 5753331. Note that a structure in which a first bracket is press-fitted and fixed from the side into the first mounting member as shown in Figure 26 of Japanese Patent No. 5753331 may also be employed.

[0073] The abutment surface on the first mounting member side and the abutment surface on the second mounting member side that constitute the stopper mechanism do not necessarily have to be provided on the bracket, and may, for example, be provided on the first mounting member and the second mounting member fixed to the main rubber elastomer body.

[0074] Regarding the members connected by the main rubber elastic body 22, for example, the member attached to the power unit side denoted by reference numeral 18 in the above embodiment may be the second mounting member, and the member attached to the vehicle body side denoted by reference numeral 20 in the above embodiment may be the first mounting member. In this case, for example, a buffer rubber is provided to cover the upper surface of the stopper receiving portion 90 of the bracket 16, and a recess that opens into the upper surface of the stopper receiving portion 90 and a protrusion that protrudes into the lower surface of the buffer rubber and fits into the recess may be provided. Note that both the abutment surface on the first mounting member side and the abutment surface on the second mounting member side that constitute the stopper mechanism may be covered with a rubber elastic body, and in that case, at least the rubber elastic body on the first mounting member side is made into the buffer rubber, and a recess and a protrusion are provided on the first mounting member side.

[0075] In the above embodiment, the lower surface of the lower buffer portion 56 has a surface shape that corresponds to the upper surface of the stopper receiving portion 90 over the entire surface, and is made substantially flat. However, for example, by providing a protruding portion that protrudes from the lower surface of the lower buffer portion 56, it is possible to actively provide portions of the lower buffer portion 56 on which the stopper load is likely to act and portions on which it is unlikely to act. [Explanation of symbols]

[0076] 10 Engine mount (vibration isolation device, first embodiment) 12 Mount body 14 First Bracket 16 Second Bracket 18 First mounting member 20 Second mounting member 22 Main rubber elastic body 24 screw holes 26 Flange-shaped part 28 Concave 30 Covering rubber 32 Connection hole 34 First mounting hole 36 Proximal connection surface 38 Tip mounting surface 40 Intermediate stopper surface (contact surface) 42 Seat 44 Recess 46 Bottom 48 Peripheral wall 50 Stopper rubber 52 Upper buffer 54 Side buffer 56 Lower shock absorber (cushion rubber) 58 Through hole 60 Convex 62 Protruding tip surface 64 Outer surface 66 Gap 68 Connecting bolt 70 Cylindrical section 72 Cover part 74 Side wall 76 Upper bottom wall 78 Right wall 80 Insertion hole 82 Mounting foot 84 Fixing piece 86 Mounting piece 88 Second mounting hole 90 Stopper receiving part 92 Notch

Claims

1. A vibration-proof device in which a first mounting member and a second mounting member are connected by a main rubber elastic body, and a stopper mechanism is provided which cushions and limits the deformation of the main rubber elastic body by abutting against each other via a cushion rubber at opposing positions on the first mounting member side and the second mounting member side, a recess having a peripheral wall is partially formed on a contact surface of the first mounting member on which the cushion rubber is superimposed and attached, the contact surface facing the second mounting member, and a protrusion is formed in the cushion rubber to fit into the recess without being adhered thereto; A gap is provided between the inner surface of the recess and the outer surface of the protrusion.

2. The vibration isolation device according to claim 1 , wherein the gap is provided between an inner circumferential surface of the recess and an outer circumferential surface of the protrusion.

3. 3. The vibration isolation device according to claim 1, wherein the gap is provided between a protruding tip surface of the convex portion and a bottom surface of the concave portion.

4. 3. The vibration isolation device according to claim 1, wherein the recesses and the protrusions of the cushioning rubber that fit into the recesses are provided at a plurality of locations in the stopper mechanism and spaced apart from each other.

5. 3. The vibration isolation device according to claim 1, wherein in the stopper mechanism, the gap set between the inner surface of the recess and the outer surface of the protrusion is adapted to disappear when a stopper load is input.

6. 3. The vibration isolation device according to claim 1, wherein an air vent passage is provided in the peripheral wall of the recess in the stopper mechanism.

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