Vibration isolation device manufacturing method and vibration isolation device

Abstract

To provide a novel method of manufacturing a vibration isolator which can accurately and stably apply targeted pre-compression to connecting rubber by preventing an unintended deformation of an attachment metal fixture in pre-compression of the connecting rubber.SOLUTION: A method of manufacturing a vibration isolator 10 includes providing a groove-shaped metal fixture 12 having a bottom wall part 18 and a pair of sidewall parts 20, 20, and an inner metal fixture 14 to be arranged apart from the bottom wall part 18 between the pair of sidewall parts 20, 20 opposite each other, and connecting the inner metal fixture 14 and the pair of sidewall parts 20, 20 of the attachment metal fixture 12 to each other with a pair of pieces of connecting rubber 16, 16. After connecting the inner metal fixture 14 and the pair of sidewall parts 20, 20 with the pair of pieces of connecting rubber 16, 16, the pair of pieces of connecting rubber 16, 16 are pre-compressed by plastically deforming a pair of the sidewall parts 20, 20 in a direction toward each other, while constraining the bottom wall part 18 of the attachment metal fixture 12 with constraint jigs 30, 32 on an outer side with respect to the inner metal fixture 14 in an opposing direction of the pair of sidewall parts 20, 20 to thus limit deformation of the bottom wall part 18.SELECTED DRAWING: Figure 5B

Description

[Technical Field]

[0001] The present invention relates to a vibration isolation device that reduces vibration of a target member to be vibration-isolated, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, vibration-damping devices that are attached to a target component to be vibration-damped and reduce the vibration of the target component have been known. For example, as shown in FIGS. 1 to 4 of JP 2019-002549 A (Patent Document 1), the vibration-damping device includes a groove-shaped mounting bracket having a bottom wall and a pair of side walls, and a mass bracket disposed between the pair of opposing side walls of the mounting bracket, with the mass bracket and the pair of side walls of the mounting bracket elastically connected by a pair of connecting rubbers. In the vibration-damping device of Patent Document 1, when the bottom wall of the mounting bracket is fixed to the target component to be vibration-damped and vibrations of the target component to be vibration-damped are input to the vibration-damping device, a vibration-damping effect is exerted due to resonance of the mass-spring system formed by the mass bracket and the pair of connecting rubbers, thereby reducing the vibration of the target component to be vibration-damped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-002549 Summary of the Invention [Problem to be solved by the invention]

[0004] When molding the connecting rubber between the opposing surfaces of the inner fitting and the pair of side wall portions of the mounting fitting, tensile stress acts on the connecting rubber due to cooling and shrinkage after molding. Therefore, in some cases, after molding the connecting rubber, the mounting fitting is plastically deformed to bring the side wall portions of the mounting fitting closer to the inner fitting, thereby reducing the tensile stress in the connecting rubber.

[0005] However, the inventors' investigations revealed a new problem: when the pair of side walls are pressed toward each other to pre-compress the connecting rubber, a bending moment acts on the bottom wall, which could cause unintended deformation such as bending the bottom wall into a curved shape. In particular, in the vibration-damping device that this invention targets, the degree of pre-compression of the connecting rubber is affected by deformation of the bottom wall, so if unintended deformation occurs in the bottom wall, it could be difficult for the vibration-damping device to stably demonstrate its inherent vibration-damping performance, and there could be an impact on durability, vibration load resistance, and mounting stability to the object to be vibration-damped, which could be a major problem.

[0006] The problem to be solved by the present invention is to provide a novel method for manufacturing an anti-vibration device that can prevent unintended deformation of the mounting bracket when pre-compressing the connecting rubber, and that enables the desired pre-compression to be applied to the connecting rubber with high precision and stability.

[0007] Another object of the present invention is to provide a vibration isolation device with a novel structure that prevents unintended deformation of the mounting bracket. [Means for solving the problem]

[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 method for manufacturing an anti-vibration device that involves preparing a groove-shaped mounting bracket having a bottom wall portion and a pair of side wall portions, and an inner bracket that is arranged between the opposing pair of side wall portions and at a distance from the bottom wall portion, and connecting the inner bracket and the pair of side wall portions of the mounting bracket with a pair of connecting rubbers, and after connecting the inner bracket and the pair of side wall portions of the mounting bracket with the pair of connecting rubbers, restraining the bottom wall portion of the mounting bracket outside the inner bracket in the opposing direction of the pair of side wall portions with a restraining jig to restrict deformation of the bottom wall portion, while plastically deforming the pair of side wall portions in the direction of approaching each other to pre-compress the connecting rubber.

[0010] According to a manufacturing method for an anti-vibration device constructed according to this aspect, when the connecting rubber is pre-compressed by plastically deforming the mounting bracket to bring the pair of side walls closer together, an external force is applied to the pair of side walls in the direction of mutual approach while the bottom wall of the mounting bracket is restrained by a restraining jig, thereby preventing bending deformation of the bottom wall due to the action of the external force. By suppressing unintended deformation of the bottom wall in this way, the inherent vibration-damping performance of the anti-vibration device is stably demonstrated. Furthermore, suppressing deformation of the bottom wall prevents a decrease in durability and vibration load resistance, and can also improve mounting stability when the bottom wall is attached to a target component for vibration isolation.

[0011] In particular, the restraining position of the bottom wall portion by the restraining jig is set at a position away from the inner metal fitting toward the side wall portion, and the bottom wall portion is restrained at a position close to the side wall portion. In this way, by limiting the deformation of the bottom wall portion at a position close to the side wall portion, which is the starting point of deformation of the bottom wall portion, it is possible to prevent the bottom wall portion from deforming at a position outside the restraining portion by the restraining jig in the opposing direction of the pair of side wall portions.

[0012] In a second aspect, in the method for manufacturing an anti-vibration device described in the first aspect, the mounting bracket has an extension portion that extends outward beyond the connecting rubber in a groove length direction perpendicular to the opposing direction of the pair of side wall portions, and the bottom wall portion of the extension portion is clamped in the thickness direction by the restraining jig to limit deformation of the bottom wall portion.

[0013] According to the manufacturing method of the vibration-damping device constructed in accordance with this aspect, by restraining the bottom wall portion at the extension portion of the mounting bracket with a restraining jig, interference between the restraining jig and the connecting rubber can be avoided. In particular, when the bottom wall portion is sandwiched between the restraining jig in the thickness direction to limit deformation of the bottom wall portion, interference between the restraining jig and the connecting rubber is prevented, and deformation of the bottom wall portion can be simply and effectively limited by sandwiching.

[0014] In a third aspect, in the method for manufacturing an anti-vibration device described in the first or second aspect, the restraining jig extends continuously along the sides of the inner metal fitting in the opposing direction of the pair of side wall portions, and the restraining jig extends to both outsides of the inner metal fitting in the opposing direction of the pair of side wall portions.

[0015] According to the manufacturing method of the vibration-damping device constructed in accordance with this embodiment, the bottom wall portion is continuously restrained by the restraining jig not only on both outsides of the inner metal fitting in the opposing direction of the pair of side wall portions, but also on the sides of the inner metal fitting, thereby more effectively preventing deformation of the bottom wall portion when the connecting rubber is pre-compressed.

[0016] In a fourth aspect, in the method for manufacturing an anti-vibration device described in the first or second aspect, a plurality of mutually independent restraining jigs are arranged between each opposing surface of the pair of side wall portions and the inner metal fitting, and the bottom wall portion is restrained by the plurality of restraining jigs at a position away from the connecting rubber in a thickness direction projection of the bottom wall portion.

[0017] According to the manufacturing method of an anti-vibration device constructed in accordance with this embodiment, the restraining jig can be effectively used to limit deformation of the bottom wall portion, while the placement of the restraining jig can be set with great freedom according to the shape and size of the inner metal fittings and connecting rubber.

[0018] A fifth aspect is a method for manufacturing an anti-vibration device described in any one of the first to fourth aspects, wherein the restraining jig includes a first jig that is superimposed on the bottom wall portion from the protruding side of the pair of side wall portions, and a second jig that is superimposed on the bottom wall portion from the opposite side to the first jig, and the bottom wall portion is sandwiched and restrained between the first jig and the second jig, and the second jig extends outward beyond the first jig in the opposing direction of the pair of side wall portions.

[0019] According to the manufacturing method of an anti-vibration device constructed in accordance with this embodiment, the first jig can be placed at a position that allows deformation of the pair of side wall portions in the direction of approaching each other, while the bottom wall portion can be supported by the second jig to a position closer to the side wall portions.

[0020] The sixth aspect is an anti-vibration device in which a groove-shaped mounting bracket having a bottom wall portion and a pair of side wall portions, and an inner bracket arranged between the opposing surfaces of the pair of side wall portions and spaced apart from the bottom wall portion are elastically connected to each other by connecting rubber arranged between each opposing surface of the inner bracket and the pair of side wall portions, and the bottom wall portion of the mounting bracket has a restrainable portion outside the inner bracket in the opposing direction of the pair of side wall portions, and the restrainable portion has restraining marks formed by the action of a restraining force.

[0021] With an anti-vibration device constructed in accordance with this embodiment, the connecting rubber is pre-compressed while the bottom wall portion of the mounting bracket is restrained in the restrainable portion, thereby ensuring the durability of the connecting rubber and preventing unintended bending deformation of the bottom wall portion due to the action of external forces during pre-compression.

[0022] In a seventh aspect, in the vibration-damping device described in the sixth aspect, the mounting bracket has an extension portion that extends further out than the connecting rubber in a groove length direction perpendicular to the opposing direction of the pair of side wall portions, and the restrainable portion is set on the bottom wall portion of the extension portion.

[0023] According to the vibration-damping device constructed in accordance with this aspect, the provision of an extension portion on the mounting fixture makes it easier to set the restrainable portion on the bottom wall portion. [Effects of the Invention]

[0024] According to the present invention, unintended deformation of the mounting fixture can be prevented when pre-compressing the connecting rubber, and the desired pre-compression can be applied to the connecting rubber with high precision and stability. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a plan view of a dynamic damper according to a first embodiment of the present invention; [Figure 2] Front view of the dynamic damper shown in Figure 1 [Figure 3] III-III cross section of Figure 1 [Figure 4] IV-IV cross section of Figure 2 [Figure 5A] A front view showing the preparation state before pre-compression of the connected rubber in the manufacturing process of the dynamic damper of Figure 1. [Figure 5B] A front view showing the pre-compression process of the connected rubber in the manufacturing process of the dynamic damper of Figure 1. [Figure 6] VI-VI cross section of FIG. 5B [Figure 7] FIG. 1 is a plan view of a dynamic damper according to a second embodiment of the present invention; [Figure 8] A cross-sectional view showing the pre-compression process of the connected rubber in the manufacturing process of the dynamic damper of Figure 7. [Figure 9] FIG. 10 is a front view showing a method for manufacturing a dynamic damper according to another embodiment of the present invention, illustrating a pre-compression step of a connected rubber member. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0027] 1 to 4 show a dynamic damper 10 for automobiles as a first embodiment of a vibration-damping device constructed in accordance with the present invention. The dynamic damper 10 has a structure in which a mounting metal fitting 12, which is attached to a member to be vibration-damped (a vehicle body 38 described below), and a mass metal fitting 14 serving as an inner metal fitting are elastically connected by a pair of connecting rubbers 16, 16. In the following description, as a general rule, the up-down direction refers to the up-down direction in FIG. 2, the front-rear direction refers to the up-down direction in FIG. 1, and the left-right direction refers to the left-right direction in FIG. 1.

[0028] The mounting bracket 12 is made of a metal such as iron or an aluminum alloy. The mounting bracket 12 is an overall groove-shaped member that has a groove-shaped cross section that opens upward and extends linearly in the front-to-rear direction, and includes a bottom wall 18 that extends substantially perpendicular to the up-and-down direction, and a pair of side walls 20, 20 that protrude upward from both left and right ends of the bottom wall 18. The mounting bracket 12 of this embodiment is a pressed metal fitting, and the bottom wall 18 and the pair of side walls 20, 20 are integrally formed by bending a metal blank. The bottom wall 18 has a substantially rectangular flat plate shape. The side wall 20 also has a substantially rectangular flat plate shape, and its length in the front-to-rear direction is substantially the same as that of the bottom wall 18.

[0029] The metal mass 14 is in the shape of a thick, substantially rectangular plate or solid block, with its length in the front-to-rear direction and width in the left-to-right direction smaller than those of the bottom wall 18, and its height in the up-down direction smaller than those of the side wall 20. The metal mass 14 is desirably made of a material with a high specific gravity, such as iron, in order to obtain a small size and large mass.

[0030] The metal mass 14 is disposed between the opposing surfaces of the pair of side walls 20, 20 at a position spaced apart from the pair of side walls 20, 20, and is disposed spaced apart above the bottom wall 18, and is disposed spaced apart inside the groove-shaped mounting metal fitting 12. The mounting metal fitting 12 and the metal mass 14 are connected to each other by a pair of connecting rubbers 16, 16.

[0031] The connecting rubber 16 has a substantially rectangular cross section and extends in the left-right direction, with its outer end face in the left-right direction fixed to the side wall 20 of the mounting bracket 12 and its inner end face in the left-right direction fixed to the side of the mass fitting 14. The end of the connecting rubber 16 on the side wall 20 side has a large cross section perpendicular to the left-right direction, thereby increasing the bonding area with the side wall 20. The end of the connecting rubber 16 on the mass fitting 14 side extends to both the top and bottom surfaces and the front and back surfaces of the mass fitting 14, thereby increasing the bonding area with the mass fitting 14. The connecting rubbers 16 are respectively arranged between the opposing surfaces of the pair of left and right side wall portions 20, 20 and the mass fitting 14, and the pair of left and right connecting rubbers 16, 16 have substantially bilaterally symmetrical shapes.

[0032] The connecting rubber 16 is formed as an integrally vulcanization-molded product 28 (see FIG. 5A ) that includes the mounting metal fitting 12 and the metallic mass 14. That is, the mounting metal fitting 12 is prepared by pressing or the like, and the metallic mass 14 is prepared by casting or the like, and these mounting metal fitting 12 and metallic mass 14 are then set in a molding die for the connecting rubber 16 (not shown). When set in the molding die, the metallic mass 14 is positioned separately on the left and right inner sides of the pair of side wall portions 20, 20 of the mounting metal fitting 12, and is also positioned separately above the bottom wall portion 18 of the mounting metal fitting 12. A rubber material is then filled into the cavity of the molding die in which the mounting metal fitting 12 and the metallic mass 14 are set, and the connecting rubbers 16, 16 are vulcanization-molded between the opposing surfaces of the pair of side wall portions 20, 20 of the mounting metal fitting 12 and the metallic mass 14, thereby elastically connecting the pair of side wall portions 20, 20 of the mounting metal fitting 12 and the metallic mass 14 by the connecting rubbers 16, 16. As a result, an integrally vulcanization molded product 28 including the mounting metal fitting 12 and the metal mass fitting 14 can be obtained.

[0033] As shown in Figure 1, the mounting fitting 12 has extending portions 22 that extend outward in both the front-to-rear direction, which is the groove length direction, relative to the metallic mass 14 and the connecting rubbers 16. The front and rear end portions of the bottom wall portion 18 that make up the extending portions 22 serve as restrainable portions 24 against which an upper jig 32, described below, is pressed. The restrainable portions 24 include portions of the bottom wall portion 18 that are located on both the left and right sides of the metallic mass 14. The restrainable portions 24 in this embodiment extend continuously in the left-to-right direction along the front-to-rear outer sides of the metallic mass 14, and both left and right ends extend outward in the left-to-right direction beyond the metallic mass 14.

[0034] A restraint mark 26 is formed on the restrainable portion 24. The restraint mark 26 is a mark indicating that a restraining force has been applied to the bottom wall portion 18 by an upper jig 32 or a lower jig 30, which will be described later. In this embodiment, the restraint mark 26 is a mark resulting from the pressing of the upper jig 32 or the lower jig 30, which will be described later. The restraint mark 26 may be, for example, a scratch, a dent, a difference in surface texture, or coloring. While FIG. 1 illustrates the restraint mark 26 resulting from the contact of the upper jigs 32, 32, which have a small contact area, the restraint mark 26 may also be formed on the underside of the bottom wall portion 18, for example, due to the contact of the lower jig 30. Furthermore, the restraint mark 26 does not have to be formed on all of the restrainable portions 24, 24, and may be formed on at least one of the restrainable portions 24, 24 of the bottom wall portion 18. In Figure 1, the entire contact area of ​​the upper jigs 32, 32 is shown by the two-dot chain line as the restraint marks 26, 26, but in this embodiment, the restraint marks 26 are formed on the upper surface of the restrainable portion 24 in at least a part of the contact area of ​​the upper jig 32 (the area surrounded by the two-dot chain line in Figure 1).

[0035] In the integrally vulcanization-molded product 28, each connecting rubber member 16 thermally shrinks when cooled after vulcanization molding, but because both left and right ends are restrained by the mounting bracket 12 and the mass bracket 14, tensile stress acts on the connecting rubber member 16 in the left and right direction when it attempts to shrink in the left and right direction after molding. This tensile stress has an adverse effect on the durability of the connecting rubber member 16, so in order to reduce or eliminate the tensile stress in the connecting rubber member 16, a pre-compression process as described below is carried out.

[0036] First, as shown in FIG. 5A , an integrally vulcanization-molded product 28 of connecting rubbers 16, 16 is set on a lower jig 30, which serves as a second jig. The integrally vulcanization-molded product 28 is set on the lower jig 30 with the mounting bracket 12 superimposed on the upper surface of the lower jig 30. The lower jig 30 has a width dimension in the left-right direction larger than that of the metal mass 14, and protrudes outward on both left-right sides from the metal mass 14. The lower jig 30 has a length dimension in the front-rear direction and a width dimension in the left-right direction larger than those of the bottom wall portion 18 of the mounting bracket 12, and the entire lower surface of the bottom wall portion 18 is located on the lower jig 30. Therefore, both left and right end portions of the lower jig 30 protrude outward on both left-right sides from the bottom wall portion 18 of the mounting bracket 12.

[0037] An upper jig 32, serving as a first jig, is disposed above the integrally vulcanization-molded product 28 set on the lower jig 30. The width of the upper jig 32 in the left-right direction is smaller than the distance between the opposing surfaces of the pair of side wall portions 20, 20, and the upper jig 32 is insertable between the opposing surfaces of the pair of side wall portions 20, 20 in the left-right direction. The upper jig 32 is displaceable and approachable from above relative to the lower jig 30. As shown in FIG. 6 , the upper jig 32 is disposed at positions offset from both the front and rear outer sides of the metallic mass 14 and the pair of connecting rubber members 16, 16 in a vertical projection. The upper jigs 32, 32 are insertable inside the extension portions 22, 22 of the mounting bracket 12 on both the front and rear outer sides of the metallic mass 14 and the connecting rubber members 16, 16. The upper jig 32 extends continuously in the left-right direction, has a width larger than that of the metallic mass 14, and extends outward in the left-right direction beyond the metallic mass 14. The lower jig 30 extends outward in both the left-right directions beyond the upper jigs 32. In this embodiment, since the lower jig 30 and the upper jigs 32 extend continuously in the left-right direction, the left-right width dimension of the lower jig 30 is larger than the left-right width dimension of the upper jigs 32. Furthermore, the left-right width dimension of the upper jigs 32 is smaller than the distance between the opposing surfaces of the side wall portions 20, and the left-right width dimension of the lower jig 30 is larger than the distance between the left-right outer surfaces of the side wall portions 20.

[0038] 5A, a pair of pressing jigs 34 are disposed on the left and right sides of the integrally vulcanization-molded product 28 set in the lower jig 30. The pressing jigs 34 are displaceable and approach the side wall portions 20 of the mounting bracket 12 from both the left and right outer sides. The inner surfaces of the pressing jigs 34 facing each other in the left-right direction serve as pressing surfaces 36 that are pressed against the left and right outer surfaces of the side wall portions 20. The pressing surfaces 36 may be flat surfaces that extend substantially perpendicular to the left-right direction, or may be overhanging inclined surfaces that slope upward and inward in the left-right direction. The pressing jigs 34 may be attached to the lower jig 30 in a manner that allows them to slide in the left-right direction, and may be part of a second jig.

[0039] 5B , after the side wall portions 20, 20 of the mounting bracket 12 and the metal mass 14 are connected with a pair of connecting rubbers 16, 16, the upper jigs 32, 32 are moved downward and pressed against the upper surfaces of the restrainable portions 24, 24 of the bottom wall portion 18 between the opposing surfaces of the side wall portions 20, 20. As a result, the restrainable portions 24, 24 of the bottom wall portion 18 are sandwiched and restrained in the vertical direction between the lower jig 30 and the upper jigs 32, 32, and deformation such as bending (warping) of the bottom wall portion 18 in the vertical direction is limited by the lower jig 30 and the upper jigs 32, 32. In this way, in this embodiment, the restraining jig that restrains the bottom wall portion 18 in the pre-compression step is made up of the lower jig 30 and the upper jigs 32, 32.

[0040] With the restrainable portions 24, 24 of the bottom wall portion 18 restrained by the lower jig 30 and the upper jigs 32, 32, pressing jigs 34, 34 are pressed against the side wall portions 20, 20 from both outer sides in the left and right direction. By pressing the pressing surfaces 36, 36 of the pressing jigs 34, 34 against the left and right outer surfaces of the side wall portions 20, 20, the side wall portions 20, 20 are plastically deformed in a direction toward each other, thereby reducing the distance between the opposing surfaces of the side wall portions 20, 20. The side wall portions 20, 20 of the integrally vulcanization-molded product 28 have an expanding shape that slopes outward in the left and right direction toward the upper side. By pressing the pressing jigs 34, 34 against the side wall portions 20, 20, the angle of the side wall portions 20, 20 with respect to the bottom wall portion 18 changes, and the upper ends of the side wall portions 20, 20 are displaced toward each other in the left and right direction. Specifically, before plastic deformation as shown in Fig. 5A, the inclination angle α of the side wall portions 20, 20 is greater than 90 degrees, and after plastic deformation as shown in Fig. 5B, the inclination angle β of the side wall portions 20, 20 is made smaller than α, preferably equal to or less than 90 degrees. Note that, taking springback into consideration, the side wall portions 20, 20 may be deformed so that their upper ends are closer to each other than at a right angle to the bottom wall portion 18 (β = 90 degrees), in other words, so that they are inclined upward and inward in the left-right direction (β < 90 degrees).

[0041] By deforming the side wall portions 20, 20 in the direction toward each other in this manner, the connecting rubber members 16, 16 can be compressed in the left-right direction between the side wall portions 20, 20 and the metal mass 14. This reduces or eliminates the tensile stress of the connecting rubber members 16, 16 that results from cooling contraction after molding, improving the durability of the connecting rubber members 16, 16. Completing this pre-compression process of the connecting rubber members 16, 16 completes the manufacturing process for the dynamic damper 10, and the dynamic damper 10 according to this embodiment can be obtained.

[0042] When the pressing jigs 34, 34 are pressed against the side wall portions 20, 20 and an external force is applied to the side wall portions 20, 20 in a direction that brings them closer to each other, a bending moment acts on the bottom wall portion 18 due to the action of the external force, which may cause deformation such as bending (warping) of the bottom wall portion 18. In this case, by pressing the pressing jigs 34, 34 against the side wall portions 20, 20 in a state in which the restrainable portions 24, 24 of the bottom wall portion 18 are sandwiched and restrained between the lower jig 30 and the upper jigs 32, 32, deformation such as bending of the bottom wall portion 18 that is caused by input to the side wall portions 20, 20 is prevented.

[0043] The restrainable portions 24, 24 of the bottom wall portion 18 extend outward beyond the mass fitting 14 in the left-right direction on both sides, and are set at positions close to the side wall portions 20, 20. As a result, deformation of the bottom wall portion 18 between the restrainable portions 24, 24 and the side wall portions 20, 20 is less likely to occur as the side wall portions 20, 20 deform in the direction of approaching each other, and deformation of the bottom wall portion 18 can be prevented over a wider range.

[0044] In this embodiment, the restrainable portions 24, 24 of the bottom wall portion 18 are provided continuously in the left-right direction, and the connecting rubber members 16, 16 are pre-compressed in a state in which the bottom wall portion 18 is sandwiched and restrained between the lower jig 30 and the upper jig, 32, 32 over substantially the entire length in the left-right direction. Therefore, deformation such as bending of the bottom wall portion 16 can be more effectively restricted during the pre-compression process of the connecting rubber members 16, 16.

[0045] The dynamic damper 10 is attached to a vehicle body 38, which is a member to be vibration-damped, by fastening the bottom wall portion 18 of the mounting bracket 12 to the vehicle body 38. The bottom wall portion 18 may be attached to the vehicle body 38 by means of, for example, welding or adhesive, or by using bolts (not shown) embedded in the bottom wall portion 18. In one example of an attachment structure to a member to be vibration-damped, the outer surface (lower surface) of the bottom wall portion 18 is overlapped and fixed in contact with a flat surface of the member to be vibration-damped (including the bracket), and unintended deformation of the bottom wall portion 18 is avoided, thereby achieving a stable attachment state. As an example of one mode of the mounting structure to the target component to be vibration-damped, the portion of the bottom wall 18 that is directly fixed to the target component to be vibration-damped (including the bracket) by bolts, welding, etc. is set to the extension 22, thereby achieving a further improvement in the technical utility of the extension 22, which is a region that is provided so as to extend outward from the mass metal fitting 14 and the connecting rubbers 16, 16 in a plan view. In other words, by utilizing the extension 22 as a direct fixing portion to the target component to be vibration-damped, it is possible to efficiently improve the strength or rigidity at the diagonal corners of the bottom wall 18, improve the shape stability of the bottom wall 18, and further contribute to stabilizing the fixed state to the target component to be vibration-damped and achieving efficient vibration-damping action. More specifically, for example, by setting a fixing portion at the restrainable portion 24 that abuts against the component to be vibration-damped and is fixed with a bolt, it is possible to make good use of the dimensional accuracy and shape stability of the flat shape of the restrainable portion 24 to achieve fixing to the component to be vibration-damped, and in particular by including the restrainable portion 24 located near the four corners near the outer peripheral edge of the bottom wall portion 18, it is possible to achieve good fixing strength, member strength, and shape stability for the mounting bracket 12, and to efficiently and stably apply vibration-damping force to the component to be vibration-damped.

[0046] When the dynamic damper 10 is attached to a vehicle body 38, it forms a secondary vibration system (mass-spring resonance system) on the vehicle body 38, with the metal mass 14 as the mass and the connecting rubbers 16, 16 as springs. The secondary vibration system formed by the dynamic damper 10 has a resonance frequency set to the frequency of the vibration to be damped that is a problem in the vehicle body 38, by adjusting the mass of the metal mass 14 and the spring constant of the connecting rubbers 16, 16. When the vibration to be damped is input from the vehicle body 38 to the dynamic damper 10, the metal mass 14 actively displaces in a resonant state, thereby absorbing the input vibration energy, thereby reducing the vibration of the vehicle body 38.

[0047] 7 shows a dynamic damper 40 as a second embodiment of a vibration-damping device constructed in accordance with the present invention. In the following description, components and parts that are substantially the same as those in the first embodiment are given the same reference numerals in the drawings and will not be described again.

[0048] The mounting bracket 42 of the dynamic damper 40 does not have the extensions 22, 22 that protrude to both the front and rear sides as in the first embodiment. Independent restraint portions 44 are set in four locations on the bottom wall portion 18 of the mounting bracket 42, on both the left and right sides of the mass metal fitting 14 and on the front and rear sides of the connecting rubbers 16, 16. A restraint mark 26 is provided on at least one of the four restraint portions 44, 44, 44, 44.

[0049] In the dynamic damper 40 of this embodiment, the restrainable portions 44 are provided on both the left and right sides of the metallic mass 14, and the restrainable portions 44 are not located on the front-to-rear outer sides of the metallic mass 14, so there is no need to provide the extending portions 22 that protrude outward from the metallic mass 14 as in the first embodiment. This makes it possible to reduce the size of the metallic mass 14 in the front-to-rear direction, and also makes it easier to reduce the weight of the metallic mass 14.

[0050] 8 , in the process of pre-compressing the connecting rubber members 16, 16 in the left-right direction, the four restrainable portions 44, 44, 44, 44 of the bottom wall portion 18 are sandwiched and restrained in the vertical direction between the lower jig 30 and four upper jigs 46, 46, 46, 46. The width dimension in the left-right direction of the upper jig 46 is smaller than the distance between the opposing surfaces of the side wall portion 20 and the metallic mass 14 in the left-right direction, and the upper jig 46 is insertable in the vertical direction between the opposing surfaces of the side wall portion 20 and the metallic mass 14. Then, by inserting the upper jigs 46, 46, 46, 46 on both the front and rear outer sides of the connecting rubber members 16, 16 between the opposing surfaces of the side wall portion 20 and the metallic mass 14, the bottom wall portion 18 of the mounting bracket 12 is sandwiched between the lower jig 30 and the upper jigs 46, 46, 46, 46 and restrained at four points, deformation such as bending of the bottom wall portion 18 can be limited. In this way, by restraining each restrainable portion 44 with the upper and lower jigs 30, 46 and applying an external force inward to the left and right of the pair of side wall portions 20, 20, the durability of the connecting rubbers 16, 16 is improved by pre-compression while unintended deformation of the bottom wall portion 18 can be prevented.

[0051] Even with the upper jigs 46, 46, 46, 46 that are independent of each other in the left-right direction as in this embodiment, if the bottom wall portion 18 is restrained on both the left and right outer sides of the mass metal fitting 14 that are located close to the side wall portions 20, 20 in the pre-compression process of the connecting rubbers 16, 16, bending deformation and the like of the bottom wall portion 18 can be effectively prevented. In other words, when the bottom wall portion 18 bends (warps), the distance between two points on the bottom wall portion 18 approaches in the left-right direction, and therefore, if both left and right end portions of the bottom wall portion 18 are restrained by the jigs 30, 46 and movement in the left-right direction is prevented, bending deformation accompanied by approaching displacement between two points on the bottom wall portion 18 in the left-right direction can be prevented.

[0052] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to those specific descriptions. For example, the specific shapes of the metal masses and connecting rubbers shown in the above embodiments are merely examples, and the shapes of the metal masses and connecting rubbers are appropriately set depending on the frequency of the vibration to be isolated and the installation space of the vibration isolation device. Furthermore, the ratio of the height of the side wall portion to the length and width of the bottom wall portion of the mounting bracket can be changed depending on the shape and size of the metal masses and connecting rubbers.

[0053] In the above embodiment, one connecting rubber 16 is provided on each of the left and right sides of the mass fitting 14, and restrainable portions 24, 24 are provided on both the front and rear outer sides of the connecting rubber 16. However, for example, if two connecting rubbers are provided on each of the left and right sides of the mass fitting 14, spaced apart from each other in the front-to-rear direction, a restrainable portion can also be set between these two connecting rubbers. When a restrainable portion is set between two connecting rubbers, there may or may not be a restrainable portion on the front and rear outer sides of the connecting rubber.

[0054] Furthermore, the pair of connecting rubbers 16, 16 arranged on both sides of the metallic mass 14 may be integrally connected to each other by, for example, a covering rubber fixed to the surface of the metallic mass 14, and the pair of connecting rubbers 16, 16 may be integrally formed. By providing such a covering rubber covering the surface of the metallic mass 14, it is possible to protect the metallic mass 14 and improve the adhesive strength to the metallic mass 14. The covering rubber may be provided so as to cover the entire metallic mass 14, or may be in the form of a belt that is provided partially in the circumferential direction of the metallic mass 14 (the circumferential direction with the left-right axis as the center axis) and extends continuously in the left-right direction.

[0055] The structures of the first and second jigs that restrain the bottom wall portion 18 during pre-compression of the connecting rubber members 16, 16 are not limited to those exemplified in the above embodiment. Specifically, for example, a lower jig 50 as the first jig and an upper jig 52 as the second jig as shown in FIG. 9 may be used. In the pre-compression process shown in FIG. 9 , the dynamic damper 10 (integrally vulcanization-molded product 28) is in an inverted state, with a pair of side walls 20, 20 protruding downward from the bottom wall portion 18. The lower jig 50 is disposed below the bottom wall portion 18 and is inserted from below between the opposing surfaces of the side walls 20, 20 and pressed against the lower surface of the bottom wall portion 18 on the front and rear outer sides of the metallic mass 14 and the connecting rubber members 16, 16. The upper jig 52 is disposed above the bottom wall portion 18 and is pressed against the upper surface of the bottom wall portion 18 from above, thereby sandwiching the bottom wall portion 18 between the lower jig 50 and the upper jig 52. The width dimension in the left-right direction of the upper jig 52 is larger than the width dimension in the left-right direction of the lower jig 50. A pair of pressing jigs 34, 34 arranged on both the left and right outer sides of the side wall portions 20, 20 are attached to the lower jig 50 in a state that allows them to slide in the left-right direction, and by pressing the pressing jigs 34, 34 against the left and right outer surfaces of the side wall portions 20, 20 while sandwiching and restraining the bottom wall portion 18 between the lower jig 50 and the upper jig 52, it is possible to pre-compress the connecting rubber members 16, 16 while suppressing deformation of the bottom wall portion 18.

[0056] The restraining mode of the bottom wall portion of the mounting bracket using the restraining jig is not necessarily limited to clamping. Specifically, for example, the bottom wall portion can be restrained by forming through holes in the bottom wall portion on both the left and right outer sides of the mass metal fitting and inserting restraining pins protruding from the restraining jig into the through holes. This type of restraining mode of the bottom wall portion using the restraining jig prevents the through-hole-forming portions of the bottom wall portion from approaching each other, thereby preventing bending and deformation of the bottom wall portion. Furthermore, since this type of restraining mode does not require a jig configuration that clamps the bottom wall portion in the vertical direction as in the above embodiment, a through hole can be formed as a restrainable portion in the portion of the bottom wall portion that overlaps with the connecting rubber. In the above-described restraining mode using the restraining pin, restraining marks are formed on at least one of the surface of the bottom wall portion where the restraining jig abuts and the inner surface of the through hole through which the restraining pin is inserted.

[0057] In the above embodiment, a vibration control device (dynamic damper) was given as an example of a vibration-damping device, but the structure of the present invention can also be applied to vibration-damping connected bodies such as an engine mount that connects a power unit and a vehicle body in a vibration-damping manner. When the present invention is applied to an engine mount and the inner metal fitting is not required to function as a mass as in the above embodiment, it is also possible to employ, for example, a rectangular tubular inner metal fitting or an even smaller inner metal fitting. This reduces the weight of the inner metal fitting, and by making the opposing surfaces of the inner metal fitting and the side walls of the mounting metal fitting approximately parallel, it is possible to facilitate the connection of the inner metal fitting and the mounting metal fitting using connecting rubber and to achieve efficient pre-compression.

[0058] The target component to be vibration-damped is not limited to the vehicle body 38, but may be, for example, the framework of a building, the housing of a home appliance, etc. In short, the vibration-damping device according to the present invention is not limited to use in automobiles, but can also be used in applications other than automobiles, such as in buildings and home appliances. [Explanation of symbols]

[0059] 10 Dynamic damper (vibration isolation device, first embodiment) 12 Mounting bracket 14 Mass fittings (inner fittings) 16 Connecting rubber 18 Bottom wall 20 Side wall 22 Extension 24 Restraintable part 26 Restraint marks 28 Integral vulcanization molding 30 Lower jig (restraint jig, second jig) 32 Upper jig (restraint jig, first jig) 34 Pressing jig 36 Pressing surface 38 Vehicle body 40 Dynamic damper (vibration isolation device, second embodiment) 42 Mounting bracket 44 Restraintable part 46 Upper jig (restraint jig, first jig) 50 Lower jig (restraint jig, first jig) 52 Upper jig (restraint jig, second jig)

Claims

1. A groove-shaped mounting bracket having a bottom wall portion and a pair of side wall portions, and an inner bracket disposed between the pair of opposing side wall portions and spaced apart from the bottom wall portion are prepared, A method for manufacturing a vibration-damping device in which the inner metal fitting and the pair of side wall portions of the mounting metal fitting are connected by a pair of connecting rubbers, A method for manufacturing an anti-vibration device in which the inner fitting and the pair of side wall portions of the mounting fitting are connected by the pair of connecting rubbers, and then the bottom wall portion of the mounting fitting is restrained with a restraining jig outside the inner fitting in the opposing direction of the pair of side wall portions to limit deformation of the bottom wall portion, while plastically deforming the pair of side wall portions in directions toward each other to pre-compress the connecting rubbers.

2. the mounting fitting has an extension portion that extends outward beyond the connecting rubber in a groove length direction perpendicular to the opposing direction of the pair of side wall portions, The method for manufacturing an anti-vibration device according to claim 1, wherein the bottom wall of the extension is sandwiched in the thickness direction by the restraining jig to restrict deformation of the bottom wall.

3. A method for manufacturing an anti-vibration device as described in claim 1 or 2, wherein the restraining jig extends continuously along the sides of the inner metal fitting in the opposing direction of the pair of side wall portions, and the restraining jig extends to both outsides of the inner metal fitting in the opposing direction of the pair of side wall portions.

4. A method for manufacturing an anti-vibration device as described in claim 1 or 2, wherein a plurality of mutually independent restraining jigs are arranged between each opposing surface of the pair of side wall portions and the inner metal fitting, and the bottom wall portion is restrained by the plurality of restraining jigs at a position away from the connecting rubber in a thickness direction projection of the bottom wall portion.

5. The restraining jig includes a first jig that is superimposed on the bottom wall portion from the protruding side of the pair of side wall portions, and a second jig that is superimposed on the bottom wall portion from the opposite side to the first jig, and sandwiches and restrains the bottom wall portion between the first jig and the second jig, 5. The method for manufacturing an anti-vibration device according to claim 1, wherein the second jig extends outward beyond the first jig in the opposing direction of the pair of side wall portions.

6. A vibration-damping device in which a groove-shaped mounting metal fitting having a bottom wall portion and a pair of side wall portions, and an inner metal fitting disposed between opposing surfaces of the pair of side wall portions and spaced apart from the bottom wall portion, are elastically connected to each other by connecting rubbers disposed between the opposing surfaces of the inner metal fitting and the pair of side wall portions, the bottom wall portion of the mounting fixture has a restrainable portion located outward of the inner fixture in the opposing direction of the pair of side wall portions, The restrainable portion has restraining marks formed by the action of a restraining force.

7. the mounting fitting has an extension portion that extends outward beyond the connecting rubber in a groove length direction perpendicular to the opposing direction of the pair of side wall portions, 7. The vibration isolation device according to claim 6, wherein the restrainable portion is set on the bottom wall of the extension portion.

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