JP5437025B2 - Vibration isolator - Google Patents

Description

  The present invention has a cylindrical shape including a shaft member, an outer cylinder surrounding the shaft member, and a vibration-proof base made of a rubber-like elastic body that is interposed between the shaft member and the outer cylinder and couples the two cylinders. The present invention relates to a vibration isolator.

  Conventionally, in this type of cylindrical vibration isolator, a metal such as iron is generally used for the inner cylinder and the outer cylinder. For example, the one shown in FIG. 9 includes a metal inner cylinder 101, a metal outer cylinder 102, and a vibration-proof base 103 made of a rubber elastic body. Then, in order to give anisotropy to the spring characteristics in the direction perpendicular to the axis, the anti-vibration base 103 is provided with a pair of straight portions 104 penetrating in the axial direction at positions opposed to the direction perpendicular to the axis to lower the spring constant. On the other hand, a pair of metal intermediate plates 105 are embedded in positions facing each other across the inner cylinder 101 in the direction perpendicular to the axis perpendicular to this to increase the spring constant.

  In such a conventional configuration, not only the outer cylinder 102 is made of metal, but the intermediate plate 105 is also made of metal, so that the weight increase is large, and therefore weight reduction is desired.

  By the way, conventionally, for the purpose of weight reduction and the like, it is known that the outer cylinder is made of resin, and various proposals have been made. For example, in Patent Document 1 below, in order to prevent defects such as cracks at the insertion end when the outer cylinder is made of resin and the outer cylinder is press-fitted into the cylindrical holding portion of the mounting member, It is disclosed that the insertion end portion is formed thickly over the entire circumference.

  In Patent Document 2 below, in order to prevent the resin outer cylinder from coming off from the cylindrical holding portion of the mounting member, a metal sleeve is extrapolated to the resin outer cylinder, thereby partially reducing the diameter of the outer cylinder. Accordingly, it is disclosed that the metal sleeve is positioned and locked between the reduced diameter portion and the enlarged diameter portion.

  Patent Document 3 below discloses that a plurality of notches are provided in a flange provided at one end of the outer cylinder in order to prevent cracking when the resin outer cylinder is press-fitted into the cylindrical holding portion of the mounting member. Has been.

  Although these patent documents disclose that the outer cylinder is made of resin, as a technique for imparting anisotropy to the spring characteristics in the direction perpendicular to the axis of the vibration isolator, the degree of freedom of shape of the resin outer cylinder is disclosed. The point of effectively utilizing is not disclosed.

JP 2002-286064 A JP 2008-223920 A JP 2008-249035 A

  An object of this invention is to provide the vibration isolator which can achieve weight reduction, giving anisotropy to the spring characteristic in a direction orthogonal to an axis.

The vibration isolator according to the present invention includes a shaft member, a resin-made outer cylinder that surrounds the shaft member in parallel with the shaft, and a rubber-like elastic member that is interposed between the shaft member and the outer cylinder to couple them together. A vibration isolating base comprising a body , wherein the outer cylinder is press-fitted and fitted into a cylindrical holding portion of the mounting member, and the outer cylinder is attached and fixed to the mounting member . The resin injected from the resin injection port set in at least one place in the circumferential direction is molded with a weld portion in at least one place in the circumferential direction, and in the circumferential position where the weld portion is formed, Protrusions are provided to increase the spring constant in the direction perpendicular to the axis by projecting inwardly in the direction perpendicular to the axis to narrow the distance from the shaft member, thereby forming the circumferential position thick. The outer cylinder is stretched outward in the direction perpendicular to the axis at one end in the axial direction. A flange issue, the convex portion, and is characterized in that in the axial direction of the outer cylinder provided closer to the free other end side of said flange.

  According to the above configuration, the spring constant in the direction perpendicular to the axis can be increased by the projection provided to project inward in the direction perpendicular to the axis, so the conventional intermediate plate is eliminated by the projection provided in the outer cylinder. can do. Therefore, the weight reduction can be achieved in combination with the outer cylinder being made of resin. In addition, by providing the convex part for giving anisotropy to the spring characteristics in the weld part with respect to the resin inlet, there is a problem such as cracking when the vibration isolator is press-fitted into the cylindrical holding part of the mounting member. It is possible to reinforce the welded portion that is prone to occur by forming the thick portion with the convex portion and prevent cracking.

Sectional drawing of the vibration isolator which concerns on 1st Embodiment (II sectional view taken on the line of FIG. 2). II-II sectional view taken on the line of FIG. The perspective view of the outer cylinder of the vibration isolator. The top view of this outer cylinder. VV sectional view taken on the line of FIG. VI-VI sectional view taken on the line of FIG. Sectional drawing of the outer cylinder of the vibration isolator which concerns on 2nd Embodiment. Sectional drawing of the vibration isolator which concerns on 2nd Embodiment. Sectional drawing of the conventional vibration isolator.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The vibration isolator 10 according to the first embodiment will be described with reference to FIGS. The vibration isolator 10 according to the embodiment is a bush-type mount for supporting a member member such as a suspension of an automobile in a vibration-proof manner with respect to a vehicle body, and in this example, a mount assembled to a rear member is shown.

  As shown in FIG. 1, the vibration isolator 10 includes a metal inner cylinder 12 as a shaft member, an outer cylinder 14 that is axially parallel and concentric with the inner cylinder 12, and a gap between the inner cylinder 12 and the outer cylinder 14. It is provided with a vibration isolating base 16 made of a rubber elastic body that is interposed by a vulcanizing and bonding means and couples them together.

  The inner cylinder 12 is a cylindrical member whose upper end 12A is attached to a vehicle body (not shown) with the axial direction X being the vertical direction, and is configured so that a bolt (not shown) is inserted inside and fastened to the vehicle body. Has been. The upper end portion 12 </ b> A of the inner cylinder 12 is formed in a diameter-expanded portion 18 that has been diameter-expanded by cold plastic working after the vulcanization molding of the vibration-proof base 16 in order to reduce the surface pressure on the vehicle body.

  The anti-vibration base 16 is formed in a cylindrical shape so as to fill the space between the inner cylinder 12 and the outer cylinder 14, and, as shown in FIG. A pair of cavities 20, 20 referred to as straight holes penetrating in the axial direction X are provided at two positions opposite to the direction perpendicular to the direction (ie, the radial direction), specifically, the vehicle longitudinal direction.

  The outer cylinder 14 is a member that is attached and fixed to the member member 1 that is an attachment member, and is press-fitted and fitted into the cylindrical cylindrical holding portion 2 provided in the member member 1 from below. The outer cylinder 14 is a cylindrical resin member, and a ring plate is provided at the lower end portion 14A, which is one end portion in the axial direction X, overhanging the outer circumference in the direction perpendicular to the axial direction Yo. Shaped flange 22 is provided. A stopper rubber portion 24 that protrudes outward in the axial direction X is formed on the lower surface of the flange 22 by rubber continuous from the vibration isolation base 16. Moreover, the outer peripheral surface is formed in the taper surface part 25 formed in the upper end part 14B which is the other end part of the axial direction X of the outer cylinder 14 toward the front-end | tip.

  The outer cylinder 14 is formed with weld portions 28 and 28 at two locations in the circumferential direction C by resin injected from resin injection ports 26 and 26 set at two locations in the circumferential direction C. In this example, as shown in FIGS. 5 and 6, the resin injection ports 26 are provided at two positions on the upper end portion 14 </ b> B of the outer cylinder 14 facing the first axis-perpendicular direction Ya across the inner cylinder 12. ing. By setting the resin injection port 26 in this way, the resin injected from the resin injection port 26 is opposed to the inner cylinder 12 in the second axis perpendicular direction Yb perpendicular to the first axis orthogonal direction Ya. Since the two portions meet, this portion becomes the weld portion 28.

  Then, at the circumferential position where the weld portion 28 is formed, a convex portion 30 is formed by the inner peripheral surface of the outer cylinder 14 projecting inward in the direction perpendicular to the axis Yi. The outer cylinder 14 is formed thick at the directional position. The projecting portion 30 projects inwardly in the direction perpendicular to the axis Yi to narrow the distance from the inner cylinder 12 and increase the spring constant in the direction perpendicular to the axis. In this example, convex portions 30 and 30 are provided at two locations opposite to each other across the inner cylinder 12 in the second axis-perpendicular direction Yb (specifically, the vehicle left-right direction). The spring constant in the direction Yb is set higher than in the case where such a convex portion is not provided.

  The convex portion 30 is provided in a circumferential portion including a circumferential position where the weld portion 28 is formed. Specifically, in the circumferential direction C of the outer cylinder 14, an intermediate position between the two resin injection ports 26 and 26. Is formed with a certain width in the circumferential direction on both sides thereof, so that the weld portion 28 is formed in the convex portion 30 even in consideration of manufacturing variations.

  The rubber thickness of the anti-vibration base 16 provided between the tip surface 30A of the protrusion 30 (that is, the inner surface in the direction perpendicular to the axis Yb) and the outer surface of the opposed inner cylinder 12 is constant in the circumferential direction C. It is formed in a curved surface. Specifically, the tip surface 30A is formed in a circular arc shape so as to be a part of a cylindrical surface surrounding the inner cylinder 12 concentrically.

  The convex portion 30 is provided close to the upper end portion 14B side where the flange 22 is not provided in the axial direction X of the outer cylinder 14. That is, the convex part 30 is not formed over the whole of the axial direction X in the circumferential position where the weld part 28 is formed, but is provided in the upper half of the range. Therefore, the outer cylinder 14 is formed in a thin-walled cylinder over the entire circumference on the lower side 14C provided with the flange 22, while the thick-walled part 31 and the thin-walled part in which the convex part 30 is formed in the circumferential direction C on the upper side 14D. 32 are formed alternately. The outer peripheral surface of the outer cylinder 14 is formed in a cylindrical surface shape having a constant outer diameter over the entire axial direction X except for the flange 22 and the tapered surface portion 25.

  The resin material forming the outer cylinder 14 is not particularly limited, and examples thereof include thermoplastic resins such as polyamide, polyester, polypropylene, and polycarbonate, and polyamide is particularly preferable. Moreover, these resin materials may be reinforced by blending, for example, a filler such as glass fiber, carbon fiber, or aramid fiber, and it is particularly preferable to blend glass fiber.

  The vibration isolator 10 of the present embodiment having the above-described configuration is obtained by vulcanizing and molding the vibration isolating substrate 16 between the inner cylinder 12 and the outer cylinder 14 after the outer cylinder 14 is manufactured by resin injection molding. Manufactured. When the outer cylinder 14 is injection-molded, the resin is injected from the two resin inlets 26 and 26 facing the first axis-perpendicular direction Ya through the gate G of the injection mold (FIGS. 5 and 6). reference). The injected resin is filled in the cavity while spreading from the resin injection port 26 on both sides in the circumferential direction C, so that the two points are opposite to the second axis perpendicular direction Yb perpendicular to the first axis orthogonal direction Ya. The welds 28 and 28 are formed in the projections 30 and 30 (see FIG. 6).

  The vibration isolator 10 manufactured in this way is fitted and fixed by press-fitting the outer cylinder 14 into the cylindrical holding part 2 of the member member 1 from the upper end part 14B provided with the tapered surface part 25. Further, a bolt (not shown) is inserted into the inner cylinder 12 and fastened to be fixed to the vehicle body side.

  In the vibration isolator 10 assembled in the vehicle, the spring constant in the vehicle front-rear direction, which is the first axis-perpendicular direction Ya, is set low by the pair of cavities 20 and 20 provided in the vibration isolation base 14. In addition, since the pair of convex portions 30 provided on the outer cylinder 14 perform the same function as the conventional intermediate plate, the spring constant in the vehicle left-right direction, which is the second axis-perpendicular direction Yb, is set high. ing. Therefore, the ride comfort is good and the steering stability can be improved.

  Thus, in the vibration isolator 10 of the present embodiment, the conventional metal intermediate plate can be abolished by the convex portion 30 provided on the outer cylinder 14, and therefore the outer cylinder 14 itself is made of resin. In combination with this, the weight can be reduced. Further, by eliminating the intermediate plate, the manufacturing process can be simplified and the number of parts can be reduced.

  Further, the vibration isolator 10 is press-fitted into the cylindrical holding portion 2 of the member member 1 by providing the weld portion 28 with respect to the resin injection port 26 with the convex portion 30 for providing anisotropy in the spring characteristics. At this time, the weld portion 28 that is likely to have a defect such as a crack can be reinforced by forming the convex portion 30 in a thick shape, thereby preventing the crack. Therefore, the trouble at the time of product assembly can be reduced.

  Further, at the time of press-fitting into the cylindrical holding portion 2, the upper end portion 14B that is press-fitted first is more likely to have problems such as cracking than the lower end portion 14A that is press-fitted later. The convex portion 30 is provided so as to be offset toward the upper end portion 14B side where such a problem is likely to occur. Therefore, it is possible to further reduce the weight by suppressing the volume of the convex portion 30 while effectively taking measures against cracks in the weld portion 28 at the time of press-fitting by the unevenly convex portion 30.

  7 and 8 relate to the second embodiment. This embodiment differs from the first embodiment in that the resin inlet 26 of the outer cylinder 14 is set at one place in the circumferential direction C.

  That is, in this example, as shown in FIG. 7, the resin injection port 26 is set at one place in the circumferential direction C of the outer cylinder 14, and therefore the inner cylinder 12 is sandwiched with respect to the resin injection port 26. A circumferential position facing the direction perpendicular to the axis Yb is the weld portion 28. And the convex part 30-1 which protrudes in the axial orthogonal | vertical direction inward Yi is provided in the circumferential direction position in which this weld part 28 is formed, By this, the said circumferential direction position is formed thickly. .

  Further, not only the weld portion 28 but also a circumferential position where the resin injection port 26 is provided is provided with a convex portion 30-2 projecting inwardly in the direction perpendicular to the axis Yi. It is formed thick.

  The shape, size, and arrangement of these convex portions 30-1 and 30-2 are the same as those of the convex portion 30 of the first embodiment. Therefore, the convex portion 30-1 provided on the weld portion 28 and the resin injection are provided. The convex portion 30-2 provided at the inlet 26 is provided symmetrically with the inner cylinder 12 interposed therebetween.

  In general, the resin injection port 26 is a portion that may impair the strength next to the weld portion 28, and therefore, by providing a convex portion 30-2 in this portion to form a thick wall, countermeasures against cracking during press-fitting are provided. It can be carried out. Further, in this case, since the resin injection port 26 is provided in the thick convex portion 30-2, the resin injection port 26 has an inward convex shape (see FIG. 6) as in the first embodiment. There is no need to form. Other configurations are the same as those of the first embodiment, and the same operational effects are achieved.

  As described above, the number of the resin injection ports 26 is not particularly limited as long as it is at least one in the circumferential direction C of the outer cylinder 14, but it is usually preferable to provide the resin injection ports 26 at the two or one place described above. Further, in the case where the weld portion 28 is formed at a plurality of locations in the circumferential direction C, it is not limited to the case where the convex portion 30 is provided at all the circumferential positions, and the convex portion 30 is provided on at least one weld portion 28. The case of providing is also included in the present invention. Further, the above embodiment is merely a preferable example with respect to the shape, size, and the like of the convex portion 30, and various changes can be made. Further, the present invention is not limited to the bush attached to the member member, and can be applied to various vibration isolators. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

10 ... Vibration isolator, 12 ... Inner cylinder (shaft member), 14 ... Outer cylinder,
14A: one end (lower end) of the outer cylinder, 14B: the other end (upper end) of the outer cylinder,
16 ... Vibration-proof substrate, 22 ... Flange, 26 ... Resin injection port,
28 ... Weld part, 30, 30-1, 30-2 ... Convex part,
X ... Axial direction, Yo ... Axis perpendicular direction outward, Yi ... Axis perpendicular direction inward,
Ya ... first axis perpendicular direction, Yb ... second axis perpendicular direction, C ... circumferential direction

Claims (5)

A shaft member, a resin-made outer cylinder that surrounds the shaft member in parallel with the shaft member, and a vibration-proof base made of a rubber-like elastic body that is interposed between the shaft member and the outer cylinder to couple them together. In the vibration isolator which is installed and fixed to the mounting member by press fitting the outer cylinder into the cylindrical holding portion of the mounting member ,
The outer cylinder is formed by having a weld portion at least in the circumferential direction by resin injected from a resin injection port set in at least one location in the circumferential direction, thereby forming the weld portion. Protrusions are provided at the circumferential position to protrude inward in the direction perpendicular to the axis, thereby narrowing the distance from the shaft member and increasing the spring constant in the direction perpendicular to the axis, thereby increasing the thickness in the circumferential direction. Formed into a flesh ,
The outer cylinder is provided with a flange projecting outward in a direction perpendicular to the axis at one axial end, and the convex part is provided close to the other end without the flange in the axial direction of the outer cylinder. Anti-vibration device characterized by The resin injection port is provided at two locations facing each other across the shaft member in the first axis perpendicular direction, and sandwiches the shaft member in the second axis perpendicular direction perpendicular to the first axis perpendicular direction. two opposite said convex portion places is formed to, characterized in that the circumferential position are formed in a thick shape claim 1 vibration isolator according. The vibration isolation device according to claim 2, wherein the vibration isolation base has a hollow portion penetrating in the axial direction at two locations facing each other in the direction perpendicular to the first axis. The resin injection port is provided at one location in the circumferential direction, the convex portion is provided at a circumferential position facing the resin injection port in a direction perpendicular to the axis across the shaft member, and the circumferential position is thick. In addition to being formed in a meat shape, the circumferential position is also formed in a thick shape by providing the convex portion projecting inward in the direction perpendicular to the axis at the circumferential position where the resin injection port is provided. The vibration isolator according to claim 1 . The tip end surface of the convex portion is formed in a circular arc shape in cross section so as to be a part of a cylindrical surface surrounding the inner cylinder concentrically. Anti-vibration device.

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