SUPPORTING ELEMENT FOR MOTOR VEHICLES ENGINES

Abstract: It is described a supporting element (1) for motor-vehicles engines comprising a sustaining collar (2) to be fixed to the motor-vehicle structure and to which inside in engaged an elastic ring (4) in elastomeric material. Inside the elastic ring is fixed a pushing element (5) to which the motor-vehicle engine is connected. The elastic ring presents a perimetral projection (10) which inferiorly protrudes from the same elastic ring very near to the pushing element and that appears pre-stressed between a perimetral portion (9a) of a cap (9) fixed to the bottom extremity of the supporting element and a bearing seat (11) obtained along the edge of the bottom extremity (5b) of the same pushing element.

Description: Description The present invention refers to a supporting element for motor-vehicles engines of the type comprising a sustaining collar having a structure substantially tubular, an elastic ring realized in elastomeric material and rigidly engaged inside the sustaining collar, a pushing element rigidly engaged inside said elastic ring and a cap rigidly engaged at the bottom extremity of the pushing element and presenting a perimetral portion that protrudes in respect to the same pushing element. As it is known, the motor-vehicles engines are, generally, elastically sustained in respect to the bearing structure of the respective motor-vehicle by suitable supporting elements. These supporting elements generally comprise a sustaining collar presenting a configuration substantially tubular and rigidly engageable to the bearing structure of the motor-vehicle. Inside the sustaining collar is rigidly engaged, through the union rubber-metal, an elastic ring to which inside is fixed - always by union rubber-metal - a pushing element, to which the engine is connected. The above mentioned ring is capable to elastically deforms owing to the weight of the vibrations transmitted by the engine, said vibrations tending to coaxially displace the pushing element in respect to the sustaining collar. Generally, to avoid possible disengagements between the elastic ring and the metallic parts to which the elastic ring is welded, it is necessary to act so that the same elastic ring, during the functioning of the supporting element, can be elastically deformed under the effect of compression stresses. To satitsfy this necessity it is presently foreseen that the sustaining collar and the pushing element are substantially shaped as tronco-conic. The elastic ring is structured in order to maintain, in absence of stresses, the pushing element slightly over in respect to the collar. These modifications allow that, when the pushing element is translated towards the inside of the collar owing to the weight of the engine, the elastic ring appears compressed between the surfaces of the pushing element and the collar. In spite of the above, it is noted that in the supporting elements realized according to the known tecnique, the elastic ring appears, in many cases, tensile stressed in correspondence of its own bottom fastening edge with the pushing element. The anomalous functioning condition originates, in time more or less long, the disengagement of the elastic ring from the pushing element, considerably compromising both the efficacy and the life of the functioning of the supporting element. The main purpose of the present invention is that of eliminating the above mentioned drawback, by a supporting element realized in such a manner to considerably reduce or, even, cancel the tensile stresses on the fastening bottom edge of the elastic ring of the pushing element. This aim and others, which will become apparent from the following detailed description, are substantially achieved by a supporting element for motor-vehicles engines, characterized by the fact that said elastic ring presents a perimetral projection which inferiorly protrudes in respect to the same very near to the pushing element which appears pre-stressed between the perimetral portion of said lower cap and a bearing seat obtained along an edge of the lower extremity of the pushing element. Further characteristics and advantages will become more apparent from the following detailed description of a preferred but not exclusive embodiment of a supporting element for motor-vehicles engines according to the present invention, given hereinafter with reference to the attached drawings, supplied only by way of not-limiting example, in which: - figure 1 is a diametrical sectional view of the supporting element in reference at rest; - figure 2 shows the supporting element of figure 1 in working conditions; - figure 3 shows, by an enlarged scale and a sectional view, a particular of the elastic ring foreseen in the supporting element according to the invention,in absence of the second checking cap. With reference to said figures, by 1 has been globally indicated a supporting element for motor-vehicles engines according to the present invention. The supporting element 1 comprises a sustaining collar 2 presenting a substantially tubular tronco-conic configuration diverging towards the up. The collar 2 is suitable to be fixed to a bearing structure of a motor-vehicle or likes, in correspondence of a fastening flange 3 radially extending along the prosecution of the upper extremity of the same collar. Inside the collar 2 is fixed, by union rubber-metal, an elastic ring 4, realized in elastomeric material, presenting a substantially tronco-conic shape converging towards the up. Inside the ring 4 is disposed a pushing element 5 fixed to the same ring always through union rubber-metal and presenting a tronco-conic configuration converging towards the low. The pushing element 5 is suitable to be connected to a motor-vehicle engine by a threaded element 6 extending through a passing hole 7 coaxially obtained inside the same pushing element. During the functioning the ring 4 is subjected to elastically deforms under the effect of the load and of other, eventual, stresses transmitted by the engine through the pushing element 5. On an upper extremity 5a of the pushing element 5 is conventionally fixed, through the threaded element 6, a first checking cap 8 that, as shown at figure 2, is destined to progressively enter on rabbet on the surface of the elastic ring 4 when the supporting element 1 is subjected to the weight of the engine. In correspondence of a lower extremity 5b of the pushing element is also fixed, always through the threaded element 6, a second checking cap 9 conventionally destined to enter on rabbet with the elastic ring 4 when the supporting element 1 is subjected, for any reason, to stresses tending to lift the same pushing element in respect to the sustaining collar 2. According to the present invention, the second cap 9, besides carrying out the described function, is subjected to assume new functional aspects which will be better apparent in the description given hereinafter. The structural configurations of the sustaining collar 2 of the pushing element 5 and of the elastic ring 4 have been studied so that, during the functioning, the elastic ring 4 is substantially subjected to compression stresses. In fact, as it can be seen by the comparison between figures 1 and 2, the translation of the pushing element 5 towards the inside of the sustaining collar 2 determines a reduction of the space existing between the outer surface of the pushing element and the inner surface of the collar. Consequently, the elastic ring appears substantially compressed between said surfaces. It is however noted that near the lower fastening edge between the elastic ring 4 and the pushing element 5 there is a portion of the same ring, marked with 4a, which would tend to be tensile stressed during the functioning of the supporting element 1. Advantageously, according to the present invention and with particular reference to figure 3, it is foreseen that the elastic ring 4 is provided with a perimetral projection 10 which inferiorly protrudes from the same near the pushing element 5, in correspondence of a bearing seat 11 preferably constituted by a recess having a curvilineal profile, obtained along the edge of the lower extremity 5b. The perimetral projection 10 presents, preferably, a section having a roundish profile and it is structured so that to inferiorly protrude in respect to the extremity 5b of the pushing element 5 when the second checking cap 9 is not engaged with this latter (fig.3). When the second cap 9 is fixed to the extremity 5b, the perimetral projection 10 is compressed between a perimetral portion 9a of the same cap and the bearing seat 11. By this way, the zones 4a of the elastic ring 4 are subjected to a prestress condition which assumes the maximum entity when the supporting element 1 is not subjected to any stress. By the application and the progressive increase of loads on the supporting element 1, it is got, instead of the generation and of the increase of tensile stresses of the zones 4a - as would happen in the known tecnique - a progressive decreasing of the compression stresses previously created in said zones in the described manner. Advantageously, giving a suitable structure and dimensions to the perimetral projection 10 and to the bearing seat 11 and, eventually, also to the second cap 9, it is possible to obtain that the zones 4a appear slightly compressed also when the supporting element 1 is subjected to stresses of the maximum, foreseen entity. By this way it is guaranteed the complete absence of tensile stresses in the elastic ring 4, and in particular in the zones 4a, during the functioning of the supporting element 1. The aims of the invention are achieved. As a matter of fact, by the reduction and/or the complete elimination of the above mentioned tensile stresses, it is cancelled any disengagement risk between the elastic ring and the pushing element. In such a connection it is underlined that, in the known tecnique, such a disengagement was always originated in correspondence of the lower fastening edge between the elastic ring and the pushing element, namely in the zones in which the effects of the modifications according to the present indication allow to eliminate the causes of the same disengagement. By this way are so improved in the time the gifts of functionality and reliability of the supporting elements of the type in reference. Although some preferred embodiments of the present invention have been described and illustrated,it is understood that the present invention includes in its scope any other alternative embodiment deriving from the above indicated inventive idea.

Claims: 1. Supporting element (1) for motor-vehicles engines, comprising: - a sustaining collar (2) having substantially a tubular configuration; - an elastic ring (4) realized in elastomeric material and rigidly engaged inside the sustaining collar; - a pushing element (5) rigidly engaged inside said elastic ring; - a checking cap (9) rigidly engaged at the lower extremity (3b) of the pushing element (5) and presenting a perimetral portion that protrudes in respect to the same pushing element, characterized by the fact that said elastic ring presents a perimetral projection (10) which inferiorly protrudes in respect to the elastic ring very near the pushing element and which appears pre-stressed between the perimetral portion (9a) of said cap (9) and the bearing seat (11) obtained along an edge of the lower extremity of the pushing element. 2. Supporting element according to claim 1, characterized by the fact that said bearing seat is constituted by a recess having a curvilineal profile obtained along the edge of the lower extremity (5b) of the pushing element (5). 3. Supporting element according to claim 1, characterized by the fact that said perimetral projection inferiorly protrudes in respect to the lower extremity of the pushing element when this latter is unprovided with said cap. 4. Supporting element per motor-vehicles engines according to the previous claims and according to what described and illustrated hereabove, to the specified purposes.

Inventors: SEGHI, PAOLO
Applicants: PIRELLI SISTEMI ANTIVIBRANTI S.P.A.
Application year: 1988
Main classification: F16F1
IPC codes: F16F1