The present invention relates to antivibration devices for vehicles, such as engine supports, antivibration sleeves for torque take-up link or similar, exhaust line supports, or other, and a rod comprising such devices.
More particularly, the invention relates to an antivibration device comprising a first annular armature surrounding a second armature, the armatures defining between them a free space, at least a first elastomer body being placed at least partially in the free space between the first and second armatures, the first body being secured to the first armature, the first elastomer body also being secured to a first intermediate armature which is adjacent to the second armature.
The purpose of the present invention is to further perfect the antivibration devices of this type, particularly by improving their service life.
For this purpose, according to the invention, an antivibration device of the type in question is characterized in that the intermediate armature has a bearing surface suitable for bearing against a bearing surface of complementary shape belonging to the second armature, and the intermediate armature being suitable for bearing against the said second armature when the first and second armatures move relative to one another in a first direction, in a first alignment corresponding to a compression of the said first elastomer body, the said first intermediate armature being free relative to the second armature and being suitable for separating itself from the said second armature when the first and second armatures move relative to one another in a second alignment opposite the said first alignment.
Thanks to these arrangements, at least the first elastomer body sustains only compression strains and no traction strain, which increases its service life. In addition, the intermediate armature may, where necessary, increase the axial rigidity of the device, in the direction of stress, that is to say its rigidity parallel to the axis X, but also makes it possible to have a greater range of linearity, that is to say to have a substantially stable rigidity of the device for various stresses.
In various embodiments of the method according to the invention, it may be possible to have recourse also to one and/or other of the following dispositions:
Furthermore, an additional subject of the invention is a torque take-up link, comprising an antivibration device as defined hereinabove.
Other features and advantages of the invention will appear during the following description of three of its embodiments, given as non-limiting examples, with respect to the attached drawings.
In the drawings:
and
In the various figures, the same reference numbers indicate identical or similar elements.
A first embodiment of the abovementioned antivibration device 10 is represented in
Furthermore, the device 10 also comprises first and second elastomer bodies 16, 18 which may, where necessary, form a single elastomer piece and which are situated either side of the internal armature 14 and inside the external armature 12. Each of these elastomer bodies 16, 18 is secured to the external armature 12. Each of the elastomer bodies 16, 18 is here in chevron form, that is to say in the form of a V whose point 20 is directed towards the internal armature 14 and whose two other ends 22, 24 are attached to the internal surface of the external armature 12, particularly by adherization. These two bodies 16, 18 are placed substantially symmetrically relative to a median plane containing the abovementioned axis Z and an axis Y perpendicular to the axis Z.
The point 20 of each elastomer body 16, 18 comprises an intermediate armature 26, 28 adjacent to the internal armature 14, which bears on the latter in the absence of stresses, without for all that being attached to the said internal armature. This intermediate armature 26, 28 is made of a rigid material, such as metal. As represented, the intermediate armature 26, 28 has a bearing surface 30 of a shape complementing that of the internal armature 14, that is to say, in this case, an arc of a circle. The length of the intermediate armature 26 is equal to that of the surface of the elastomer body 16 to which it is attached.
When the device 10 sustains no stress, the intermediate armatures 26, 28 of the elastomer bodies 16, 18 bear against the external surface of the internal armature 14.
When a force is applied between the first and second armatures along an axis X perpendicular to the abovementioned axes Y, Z, for example in a first alignment tending to compress the elastomer body 16, the elastomer body 18 remains immobile, the intermediate armature 28 not being attached to the internal armature 14. Similarly, when a force is applied in the direction X but in a second alignment opposite the first alignment, the elastomer body 16 remains immobile while the elastomer body 18 is compressed.
This prevents one of the elastomer bodies 18 from sustaining a traction force when the other elastomer body 16 sustains a compression force and consequently this increases the service life of the elastomer bodies.
In addition, the intermediate element 26, 28 increases the rigidity of the antivibration device along the axis X. It also makes it possible to have a greater range of linearity, that is to say to have a substantially stable rigidity of the device for various stresses.
The elastomer bodies 16, 18 being completely independent of one another, it could, where necessary, be possible to make them out of different elastomers according to the stress alignment of the device.
The second embodiment of the invention represented in
In
In similar manner, the clearance may be arranged between each intermediate armature and the external armature of an antivibration device of the type represented in
In another embodiment, illustrated in
It is also possible, thanks to the device 10 according to the invention, to create a vibrating mass formed by the intermediate element 26, 28, 27, 29 and the elastomer body 16, 18. That is to say that the elasticity of the elastomer body 16, 18 and the mass of the intermediate element 26, 28, 27, 29 are computed so as to obtain a vibrating mass which is used, by resonance effect, to obtain a desired response curve as a function of the frequency of vibration.
Number | Date | Country | Kind |
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FR 04 03224 | Mar 2004 | FR | national |