GB2104619A

GB2104619A - A damped resilient mounting, for vehicle engine

Info

Publication number: GB2104619A
Application number: GB08217935A
Authority: GB
Inventors: Gunter Eberhard; Jurgen Heitzig
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1981-06-29
Filing date: 1982-06-21
Publication date: 1983-03-09
Also published as: FR2508582A1; FR2508582B1; IT8222062A0; IT1151808B; DE3125464A1

Abstract

Throttle bores having damping fluid passing therethrough are usually provided in resilient engine mountings having rubber shock-absorbing elements 4, 6 and hydraulic damping. According to the invention, the bores are formed by the continuous channels in a cellular or porous substance 10 (sponge rubber, expanded plastics, packed textiles, non-woven materials and sintered materials). The throttle noises which were otherwise inevitable are hereby considerably reduced. The porous substance controls flow between the chambers 7. <IMAGE>

Description

SPECIFICATION A resilient mounting, especially for the drive motor in motor vehicles The present invention relates to resilient mountings, especially for the drive motor in motor vehicles, including shock-absorbing elements, which are made of rubber or rubber-like plastics material, and are inserted between rigid connection members with adhesive bonding thereto, and a damping device in the form of a hollow chamber, which is filled with a damping fluid and is split into two partial chambers by a dividing wall provided with overflow bores, between the connection members.

Numerous designs for resilient engine mountings having hydraulic damping are known.

In every case, in order to achieve the desired damping of occurring vibrations, the throttle effect of the overflow bores, provided with a comparatively narrow cross-section, is utilised.

The rapidly-changing and intensely-turbulent flow processes in metallically defined, sealed chambers thereby constantly produces noises which are often considered in fact to be annoying during travel, but such noises could not, or could not to any substantial degree, be affected by known structural means, and consequently they had to be accepted as inevitable. In contrast thereto, the invention seeks to eliminate, or at least considerably reduce, the so-called throttle noises without any disadvantageous repercussion on the damping or in fact on the function of the mounting.

According to the present invention there is provided a resilient mounting, especially for the drive motor in motor vehicles, including spring elements, which are made of rubber or rubber-like plastics material, and are inserted between rigid connection members with adhesive bonding thereto, and a damping device in the form of a hollow chamber, which chamber is filled with a damping fluid and is split into two partial chambers by a dividing wall provided with overflow bores between the connection members, in which the overflow bores formed in the dividing wall are formed, at least in part, by the continuous or interconnected channels in an open-cellular porous substance.

In such a case, the dividing wall may be formed by two rigid support plates which are provided with openings therein and enclose the porous substance therebetween, or, the wall may be formed selectively instead by the porous substance itself which, in this case, is non-resilient or is provided with perforated reinforcement inserts.

The invention eliminates the provision of a definite throttle bore in the hydraulic damping portion of the mountings, the noise of which could not be permanently influenced, even by employing special structural measures -- long flow paths, rounded edges, and the like - and the invention introduces, instead of surface-extended overflow area by means of a plurality of fine, partially intertwined channels or cells in the porous substance. Such a branching of the throttle crosssection, which is increased at the extremities and is similar to a diffused disintegration, achieves in a surprising manner a reduction in the noise level to an extent which was otherwise incapable of being achieved.

All the known expanded plastics materials, sponge rubber and similarly porous, even microporous, elastomers are examples of suitable media, provided that their pores or cells are not self-contained, but form a continuous channel system which is open towards the external surfaces. From this point of view, however, packed textiles, non-woven materials, sinter materials and many other are also included. On the assumption of a resiliently compressible throttle material, its volume is advantageously so dimensioned that it completely fills the space between the two support plates of the dividing wall in its noncompressed state, while, however, by making the volume of a non-resilient throttle material less than the space available, a predetermined clearance can be produced for the full introduction of the intended damping.By selecting a material which is particularly suitable for each proposed application of use, the invention provides, in every case, the pre-requisites for observing the regulation, generally valid for engine mountings, of further suppressing the throttle effect to achieve better sound-proofing with small vibrational amplitudes.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawing in which the single figure is a schematic view of one embodiment with two modifications. The drawing shows a cross-section, divided into two partial views, through an engine mounting having a dividing wall composed of two support plates on either side of a layer of a porous substance, wherein: Fig. 1 a presupposes the use of a resiliently compressible porous substance, and Fig. 1 b presupposes the use of a non-resilient porous substance.

The illustrated mounting includes two metallic connection members 2 and 3 which are supported in a resilient and relatively movable manner by means of a rubber shock-absorbing element 4 in the shape of a hollow truncated cone, and which members 2 and 3 are provided with fixedly mounted screw-bolts 12 and 1 3 so as to be connected, on the one hand, to the body of the vehicle and, on the other hand, to the engine. In the embodiment illustrated, an additional insert member 5 is accommodated in a freely-oscillating manner in the lower cup-shaped connection member 3 connected to the vehicle body, and the additional insert member 5 is supported on the lower cup-shaped connection member 3 by means of a truncated-cone-shaped rubber shockabsorbing element 6 which is identical to the shock-absorbing element 4.

The two connection members 2 and 3 enclose a hollow chamber 7, and with the incorporation of the spring elements 4 and 6 and the insert member 5, enable the hollow chamber 7 to be completely filled with a damping fluid via a filler aperture, which is normally sealed by a locking screw 8 and is formed in the upper connection member 2. A dividing wall spans the hollow chamber 7 in parallel alignment with the connection members, which dividing wall is formed, in the embodiment illustrated, by two metallic support plates 9, each provided with openings 19, and by a porous substance 10 which is accommodated between the support plates 9 and covers the entire surfaces thereof.The dividing wall divides the hollow chamber 7 into two partial chambers which are each completely filled with the damping fluid and are in constant communication with one another, even if such communication is intensely throttled, via the open channel system in the porous substance 10. As soon as the volumes in the two partial chambers seek to change themselves in opposite directions to one another, as a consequence of the changes in shape of the spring elements 4 and 6 caused by spring movements, the throttling influence of the porous substance 10 acts in opposition to the equalizing flow then being introduced.

In the embodiment shown in Fig. 1 a, the initial rigidity of the resiliently compressible porous substance 10 is first to be overcome, before the damping effect is fully employed. In the embodiment shown in Fig. 1 b, however, a small clearance -- approximately of an order of magnitude of a few tenths of a millimetre -- is provided for the porous substance 10 which is non-resilient in this case.

Claims

1. A resilient mounting, especially for the drive motor in motor vehicles, including spring elements, which are made of rubber or rubber-like plastics material, and are inserted between rigid connection members with adhesive bonding thereto, and a damping device in the form of a hollow chamber, which chamber is filled with a damping fluid and is split into two partial chambers by a dividing wall provided with overflow bores, between the connection members, in which the overflow bores formed in the dividing wail are formed, at least in part, by the continuous or interconnected channels in an opencellular porous substance.

2. A mounting as claimed in claim 1, in which the dividing wall is formed by two rigid support plates which are provided with openings therein and enclose the porous substance therebetween.

3. A mounting as claimed in claim 2, in which the porous substance completely fills the space between the support plates in its uncompressed state.

4. A mounting as claimed in claim 3, in which the porous substance is resiliently compressible.

5. A mounting as claimed in claim 2, in which the porous substance, which covers the whole surface of one support plate in its tension-free state, has a volume which is smaller than the space between the support plates.

6. A mounting as claimed in claim 1, in which the dividing wall is formed from a non-resilient porous substance.

7. A mounting as claimed in claim 1, in which the dividing wall is formed from a porous substance provided with perforated reinforcement inserts.

8. A resilient mounting, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.