JP2007263347A - Vibration isolating bush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolating bush that is easy in the insertion of a ring-shaped stopper member press-fitted and fixed to the external peripheral surface of an extension of an inner cylindrical metal fitting via a rubber-coated layer, and can surely prevent the drop out of the stopper member. <P>SOLUTION: The vibration isolating bush 10 comprises: an outer cylindrical metal fitting 11; the inner cylindrical metal fitting 13 being the extension 14 that is separately arranged inside the radial direction and extends in the axial direction from the end of the outer cylindrical metal fitting 11 at one end side in the axial direction; a main body rubber elastic body 16 that connects the outer cylindrical metal fitting and the inner cylindrical metal fitting; the rubber-coated layer 17 that coats the external peripheral surface of the extension 14; and the ring-shaped stopper member 21 that is press-fit and fixed to the external periphery of the extension 14 via the rubber-coated layer 17. Engaging protrusions 18 extending to the radial direction and protruding to the radial direction at four points in the circumferential direction are formed at the end side in the axial direction of the rubber-coated layer 17. On the stopper member 21, engagement protrusions 23 that are engaged with troughs 18b sandwiched by crests 18a of the engaging protrusions 18 in positions that correspond to the engaging protrusions 18 of the external peripheral surface of a center hole 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, the inner and outer cylinder fittings are connected by a main rubber elastic body, and the end of the inner cylinder fitting is an extending portion extending in the axial direction from the end of the outer cylinder fitting, and is covered with a rubber coating layer. The present invention relates to an anti-vibration bush used for a front lower arm bush or a body mount of a vehicle, in which an annular stopper member for displacement control is inserted and fixed on the outer peripheral surface of the extended portion.

  This type of anti-vibration bushing is used in a state where, for example, an outer cylinder fitting is press-fitted into a vehicle front lower arm or the like, and then a stopper member is fitted to an extension portion of the inner cylinder fitting from the end of the outer cylinder fitting. It is often transported to another place such as an assembly factory and assembled to a vehicle. Therefore, the stopper member needs to be securely attached so as not to drop off from the vibration-proof bushing during transportation. Conventionally, as this type of anti-vibration bush, for example, as shown in Patent Document 1, a rubber elastic body is provided near both ends of an inner cylinder fitting longer than the outer cylinder fitting, and a side stopper (stopper member) of the rubber elastic body is fitted. There is known a cylindrical anti-vibration rubber in which an annular convex portion is provided at or near the portion to prevent a stopper member fitted by the convex portion from coming off. However, in this anti-vibration rubber, when the stopper member is press-fitted into the rubber elastic body, it is necessary for the stopper member to get over the annular convex portion over the entire circumference. There is a problem that workability is impaired. In particular, when the stopper member is made of rubber alone, it is easy to deform, so that it becomes more difficult to insert the stopper member.

Further, in this publication, a convex portion is formed at one place in the circumferential direction of the rubber elastic body, a central hole of the stopper member is formed in a shape corresponding to the convex portion, and corresponds to the convex portion of the central hole of the stopper member. About the anti-vibration rubber that fits the concave part into the convex part and rotates the stopper member when the convex part comes outside the stopper member, thereby engaging the stopper member with the convex part and preventing its falling off Is also described. However, in this case, the convex portion is only at one place in the circumferential direction, and the engagement between the convex portion and the stopper member is only at one place in the circumferential direction. The member is easy to drop off. Further, in order to sufficiently secure the engagement with the stopper member and to prevent the stopper member from dropping off, the height of the convex portion in the radial direction is increased to some extent. However, there is also a problem that the convex portion is easily damaged when the convex portion is caught in the mold when the mold is molded in the axial direction after the rubber molding.
Japanese Patent Laid-Open No. 5-118367

  In addition, in order to facilitate the insertion of the annular stopper member into the extension part of the inner cylinder fitting through the rubber coating layer and to prevent the stopper member from falling off, the stopper member is extended with an adhesive. There is a method to fix to the part. However, when an adhesive is used, the adhesive tends to adhere to the end of the inner cylinder fitting. Therefore, there is a problem that when the inner cylinder fitting is fixed to the mating member by fastening the bolt, the bolt is easily loosened due to the presence of an adhesive. Further, the use of the adhesive increases the cost of the vibration isolating bush.

  The present invention is intended to solve such a problem, and it is easy to insert an annular stopper member that is fitted and fixed to the outer peripheral surface of the extending portion of the inner cylindrical metal fitting through a rubber coating layer, and the stopper member. An object of the present invention is to provide an anti-vibration bushing that can reliably prevent falling off.

  In order to achieve the above-mentioned object, the structural feature of the present invention is that the outer cylinder fitting and the outer cylinder fitting are spaced apart from each other in the radial direction, and one end side in the axial direction is pivoted from the end of the outer cylinder fitting. An inner cylinder fitting that is an extending part extending outward in the direction, a main rubber elastic body that connects the inner cylinder and the outer cylinder fitting, a rubber coating layer that covers the outer peripheral surface of the extension part, and a rubber coating In a vibration-proof bushing having an annular stopper member inserted and fixed to the outer peripheral surface of the extending portion via a layer, in a circumferential direction with a predetermined length at a fitting position with the stopper member of the rubber coating layer A plurality of engaging projections extending radially outward and spaced apart from each other in the circumferential direction are sandwiched between crests and crests at both axial ends of the engaging projections, and radially inward between them. The stopper member is provided with a central hole in the central portion, and the stopper member is provided with a central hole in the radial direction at a position corresponding to the engaging convex portion on the inner peripheral surface of the central hole. The fitting projections are provided in the projections, and the engagement projections are fitted to the portions sandwiched between the fitting projections in the circumferential direction, and the stopper member is rotated in the circumferential direction to engage with the fitting projections. It is to be inserted and fixed in a crimped state in the valley portion of the joint convex portion.

  In the present invention configured as described above, the plurality of fitting convex portions provided on the inner peripheral surface of the central hole in the central portion of the stopper member are respectively sandwiched by the plurality of engaging convex portions provided in the rubber coating layer. The stopper member is inserted into the outer peripheral surface of the rubber coating layer up to the position of the engaging convex portion in the axial direction in a state where it is aligned with the circumferential portion. At this time, since the fitting convex portion of the stopper member is not caught by the engaging convex portion, the stopper member can be easily inserted into the extending portion via the rubber coating layer, and the insertion workability is improved. . Further, by rotating the stopper member at the position of the engaging convex portion, the plurality of fitting convex portions are easily fitted to the engaging convex portions protruding from the rubber coating layer, and the fitting convex portions are the engaging convex portions. It is sandwiched between peaks on both sides in the axial direction and is securely fixed to the valleys in a crimped state. Therefore, in the present invention, the stopper member is reliably prevented from falling off from the extending portion of the inner cylinder fitting.

  Further, in the present invention, by setting the outer diameter of the rubber coating layer to be larger than the inner diameter of the fitting convex portion of the stopper member, the fitting convex portion of the stopper member is slightly caught by press fitting into the rubber coating layer. Since the fitting convex portion does not catch on the engaging convex portion, the stopper member can be easily inserted as a whole. Furthermore, when the fitting convex part of the stopper member is fitted between a pair of crests of the engaging convex part provided in the rubber coating layer, the pressure-bonding state of the fitting convex part to the engaging convex part is strengthened and the crest is raised. Since it is sandwiched between the portions and firmly fixed to the troughs, the stopper member is more reliably prevented from falling off from the outer peripheral surface of the inner cylinder fitting.

  Moreover, in this invention, it is preferable that an engagement convex part and a fitting convex part are arrange | positioned at equal intervals in the circumferential direction. As a result, the fitting convex portion of the stopper member can be easily positioned and inserted between the engaging convex portions of the rubber coating layer, so that the stopper member can be attached to the extension portion via the rubber coating layer. Is more easily performed. Furthermore, by disposing a plurality of engaging projections at equal intervals in the circumferential direction, the stopper member can be sufficiently provided even if the distance between the rubber coating layer and the engagement projections in the radial direction is not set large. Since the crimping state with the fitting convex portion is strengthened, it is possible to reduce damage that occurs when the peaks provided at both ends in the axial direction of the engaging convex portion are removed from the mold.

  According to the present invention, since the stopper member can be easily inserted into the extending portion of the inner cylinder fitting through the rubber coating layer, the workability of inserting the stopper member is improved. Further, in the present invention, the plurality of engaging convex portions on the inner peripheral portion of the stopper member can be firmly inserted and fixed in a crimped state on the plurality of engaging convex portions provided on the rubber coating layer. It is possible to reliably prevent the member from falling off from the extending portion of the inner cylindrical metal fitting, and it is possible to reliably transport the vibration isolating bush to which the stopper member is attached to another place.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a vibration isolating bush 10 assembled between a front lower arm and a vehicle body side member of a vehicle according to an embodiment in a sectional view and a right side view, and FIG. 3 shows a right side portion of the vibration isolating bush. Is shown by an enlarged sectional view. 4 and 5 show a stopper member attached to the vibration isolating bush by a front view and a cross-sectional view.

  The anti-vibration bushing 10 is separated from the outer cylinder fitting 11 which is a thin pipe provided with an outer flange portion 12 extending radially outward on the left end side in the axial direction (left end side in FIG. 1) and radially inward. Then, the axially opposite ends of the outer cylindrical fitting 11 that are arranged coaxially are elastic between the inner cylindrical fitting 13 and the inner and outer cylindrical fittings 13, 11, which are thick pipes that extend axially outward from both axial ends of the outer cylindrical fitting 11. A rubber elastic layer 16 connected to the outer peripheral surface, a rubber coating layer 17 coated on the outer peripheral surface of the extending portion 14 on the right side (right side in FIG. 1) of the inner cylinder fitting 13, and a rubber coating on the outer peripheral surface of the extending portion 14. A stopper member 21 inserted and fixed via the layer 17 is provided.

  The rubber covering layer 17 is a thin, flat rubber layer, and extends integrally from the main rubber elastic body 16 and is provided on the outer peripheral surface excluding the right end of the extending portion 14 of the inner cylinder fitting 13. The rubber coating layer 17 has four engaging protrusions 18 that protrude in the radial direction at four positions at equal intervals in the vicinity of the right end and 90 ° apart in the circumferential direction. Each engaging projection 18 extends in the range of a central angle of 45 ° in the circumferential direction and is spaced apart from each other in the circumferential direction. Thereby, the circular arc-shaped flat part 19 between the circumferential directions of each engagement convex part 18 is arrange | positioned at equal intervals in the circumferential direction with the same length as the engagement convex part 18 of 45 degrees of central angles. As shown in FIG. 3, the engaging protrusion 18 includes a pair of ridges 18 a whose axial cross-sectional shape protrudes in a radial shape from the surface of the flat rubber coating layer 17 at two locations slightly apart in the axial direction. The valley portion 18b is recessed between the two mountain portions 18a. The trough portion 18 b is almost the same height as the flat surface of the rubber coating layer 17. The rubber coating layer 17 is formed integrally with the main rubber elastic body 16 by rubber vulcanization molding with the outer cylinder fitting 11 and the inner cylinder fitting 13 set in a molding die.

Incidentally, the outer diameter of the flat portion of the valley 18b i.e. rubber coating layer 17 and phi _A, when the outer diameter phi _B at the crest 18a, a (φ _B -φ _A) / 2 That crests 18a The difference in height of the valley portion 18b is preferably in the range of 0.5 to 1.5 mm. When the difference is smaller than 0.5 mm, the force for clamping the stopper member 21 by the engaging convex portion 18 becomes weak, and the stopper member 21 is likely to drop off from the inner cylinder fitting 13. Moreover, when the difference is larger than 1.5 mm, it is difficult to remove the mold when the engaging convex portion 18 is molded, and the engaging convex portion 18 is easily damaged.

As shown in FIGS. 4 and 5, the stopper member 21 is made of a thick rubber elastic body and has an annular plate shape having a large-diameter center hole 22 at the center, and the outer diameter is the outer diameter of the outer cylinder fitting 11. The inner diameter of the center hole 22 is substantially the same as the outer diameter of the outer peripheral surface of the rubber coating layer 17. The central hole 22 has a curved axial cross-sectional shape that extends in the range of a central angle of 45 ° in the circumferential direction and protrudes in the radial direction at four equally spaced locations in the circumferential direction at 90 ° in the axial direction. It has four fitting convex parts 23 which are the shape of a mountain. Thereby, the arc-shaped flat part 24 between the circumferential directions of each fitting convex part 23 is also arrange | positioned at equal intervals in the circumferential direction with the same length as the fitting convex part 23 of 45 degrees of central angles. Further, the four fitting protrusions 23 correspond to the four engagement protrusions 18 protruding from the rubber coating layer 17, and the width in the axial direction of the both mountain portions 18 a of the engagement protrusions 18. Approximately equal to the distance between the tops. Incidentally, when the inner diameter at the fitting projection 23 positions of the central hole 22 and the phi _C, the outer diameter phi _A of the above valleys 18b, have a relationship of φ _A> φ _C.

Next, the attachment of the stopper member 21 to the extending portion 14 of the inner cylinder fitting 13 will be described. As schematically shown in FIG. 6, the four fitting convex portions 23 provided in the central hole 22 of the stopper member 21 are replaced with the flat portions in the circumferential direction between the four engaging convex portions 18 provided in the rubber coating layer 17. 19, the stopper member 21 is inserted into the outer peripheral surface of the rubber coating layer 17 up to the position of the engagement protrusion 18 in the axial direction by press-fitting. Here, since the inner diameter φ _C at the fitting convex portion 23 is smaller than the outer diameter φ _A at the flat portion 19, the fitting convex portion 23 is inserted into the flat portion 19 while being slightly compressed. 7, only the fitting convex portion 23 bites into the flat portion 19 and the other portions are in a substantially line contact state away from the flat portion 19 as shown in the axial cross-sectional shape in FIG. Therefore, the insertion resistance of the stopper member 21 is small, and the insertion work is performed without difficulty. As a result, in the present embodiment, the stopper member 21 can be easily inserted into the extending portion 14 via the rubber coating layer 17, and the insertion workability is ensured satisfactorily.

  Then, by rotating the stopper member 21 at the position of the engaging convex portion 18, four fitting convex portions 23 are formed on the engaging convex portion 18 protruding from the rubber coating layer 17 as schematically shown in FIG. 8. Easy to fit. As shown by the axial cross-sectional shape in FIG. 9, the fitting convex portion 23 is sandwiched between a pair of peak portions 18 a on both sides in the axial direction of the engaging convex portion 18, and is firmly attached to the trough portion 18 b at the axially intermediate position. It is locked to. As a result, in this embodiment, the stopper member 21 is reliably prevented from falling off from the extending portion 14 of the inner tube fitting 13, so that the vibration isolating bush 10 to which the stopper member 21 is attached is reliably moved to another place. Can be transported.

  Further, in the present embodiment, the engaging convex portion 18 and the fitting convex portion 23 are arranged in the same shape at equal intervals in the circumferential direction, so that the fitting convex portion 23 of the stopper member 21 is formed on the rubber coating layer 17. The flat member 19 between the engaging projections 18 can be easily aligned and inserted, and the stopper member 21 can be easily attached to the extending portion 14 via the rubber coating layer 17. Furthermore, by disposing four engaging convex portions 18 at equal intervals in the circumferential direction, a sufficient stopper can be obtained without setting a large distance between the rubber coating layer 17 and the radially outer side of the engaging convex portion 18. The crimping state with the fitting convex part 23 provided in the member 21 is strengthened. Therefore, in the present embodiment, it is possible to reduce damage that occurs when the crests 18a provided at both ends in the axial direction of the engaging projection 18 are removed from the mold.

  In addition, in the said Example, although the engagement convex part 18 of the rubber coating layer 17 and the four fitting convex parts 23 of the stopper member 21 are each provided in the circumferential direction, it is not restricted to this, Two or more It may be a plurality. Moreover, in the said Example, although the engagement convex part 18 of the rubber coating layer 17 and the fitting convex part 23 of the stopper member 21 are each provided in the circumferential direction at equal intervals, it is not restricted to this, The shape and interval may be different. Furthermore, in the said Example, although the anti-vibration bush which provided the extension part 14 in one side of the inner cylinder metal fitting 13 and attached one stopper member 21 to it is demonstrated, not only this but an inner cylinder metal fitting is demonstrated. It is also possible to apply the present invention to an anti-vibration bush provided with extending portions on both sides and having a stopper member attached to each.

  Moreover, although the said Example demonstrated the anti-vibration bush for front lower arms, this invention is applicable similarly to other body mounts, sub-frame mounts, etc. In addition, the structure of each part of the anti-vibration bush shown in the above embodiment is merely an example, and various modifications can be made without departing from the gist of the present invention.

  In the present invention, the stopper member can be easily inserted into the outer peripheral surface of the rubber coating layer by press-fitting, and the stopper member is rotated at the position of the engaging convex portion so that the fitting convex portion is sandwiched between the mountain portions on both sides. By firmly locking the valley in the middle position in the axial direction in a crimped state, the stopper member can be reliably prevented from falling off the inner cylinder fitting, and the anti-vibration bush with the stopper member attached can be reliably moved to another location. It is useful because it can be transported.

It is sectional drawing of the II line direction of FIG. 2 which shows the anti-vibration bush which is one Example of this invention. It is a right view which shows a vibration proof bush. It is an expanded sectional view which expands and shows the extension part vicinity of the inner cylinder metal fitting of a vibration proof bush. It is a front view which shows the stopper member of a vibration proof bush. It is sectional drawing of the VV line direction of FIG. 4 which shows the stopper member. It is a schematic diagram which shows roughly the relationship with the rubber coating layer at the time of inserting the stopper member into an extension part. It is an expanded sectional view which expands and shows the axial cross-sectional shape in the position shown by the arrow VII of FIG. 6 which shows the relationship between the stopper member and a rubber coating layer schematically. It is a schematic diagram which shows roughly the fitting relationship between the fitting convex part of the stopper part, and the engaging convex part provided in the rubber coating layer. It is an expanded sectional view which expands and shows the axial cross-sectional shape in the position shown by the arrow IX of FIG. 8 which shows the fitting relationship of the stopper member and a rubber coating layer schematically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Anti-vibration bush, 11 ... Outer cylinder metal fitting, 13 ... Inner cylinder metal fitting, 14 ... Extension part, 16 ... Main body rubber elastic body, 17 ... Rubber coating layer, 18 ... Engagement convex part, 18a ... Mountain part, 18b ... trough part, 21 ... stopper member, 22 ... center hole, 23 ... fitting convex part.

Claims (3)

An outer cylinder and an inner cylinder that is spaced apart inwardly in the radial direction of the outer cylinder and that has one axial end extending from the end of the outer cylinder to the axially outer side A metal fitting, a main rubber elastic body connecting the inner cylinder and the outer cylinder metal fitting, a rubber coating layer covering the outer circumferential surface of the extension portion, and an outer circumferential surface of the extension portion via the rubber coating layer In the anti-vibration bush provided with the annular stopper member fixed by insertion,
A plurality of engaging projections extending in the circumferential direction by a predetermined length and projecting radially outward at a fitting position of the rubber coating layer with the stopper member are arranged spaced apart in the circumferential direction, While providing a crest and a trough that is sandwiched between the crests at both ends in the axial direction of the engagement convex part and recessed inward in the radial direction,
The stopper member is provided with a central hole at the center, and a fitting convex portion protruding radially inward at a position corresponding to the engaging convex portion on the inner peripheral surface of the central hole is provided in the circumferential direction. The engaging convex portion is fitted to the portion sandwiched between the fitting convex portions, the stopper member is rotated in the circumferential direction, and the fitting convex portion is crimped to the valley portion of the engaging convex portion. Anti-vibration bush characterized by being inserted and fixed with. The anti-vibration bush according to claim 1, wherein an outer diameter of the rubber coating layer is larger than an inner diameter of the fitting convex portion of the stopper member. The anti-vibration bush according to claim 1 or 2, wherein the engaging convex portion and the fitting convex portion are arranged at equal intervals in the circumferential direction.

Images