GB1560335A

GB1560335A - Motor vehicle

Info

Publication number: GB1560335A
Application number: GB3867577A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-09-20
Filing date: 1977-09-16
Publication date: 1980-02-06
Also published as: DE2740285C2; DE2740285A1; SE429427B; FR2364779B1; FR2364779A1; AT345675B; SE7710450L; IT1143686B; JPS5338030A; ATA696876A

Description

(54) MOTOR VJHCLE (71) I, HANS LIST, an Austrian Citizen of 126 Heinrichstrasse, Graz, Austria, do hereby declare the invention for which I pray that a Patent may be granted to me and the method by which it is to be performed to be particularly described in and by the following statement: This invention concerns a motor vehicle of the kind comprising an engine which is provided with an oil sump secured in bodysound-insulated manner to the engine block and a fan-cooled water-radiator.

It is commonly known that the total noise emission from a vehicle consists of the individual component noises which are pro ducedl by the exhaust system, the air intake system, the cooling unit, the surface of the drive unit comprising the engine and gearbox and, to a lesser extent also by the rear axle and the vehicle body. Various methods and means have already been adopted for reducing exhaust and air-intake noise as well as the noise produced by the cooling unit, that is fan noise. The conventional arrangements for reducing engine-surface and possibly also gearbox noise (disregard( ing for the present any provisions of limited effect at the points of noise origin, e.g. pressure increase in diesel combustion, mechanical knocking of pistons, gears, etc.) involve the provision of noise-suppressing engine compartment or the construction of special low-noise engines which comprise an outer casing which is body-sound insulated relative the operative internal engine structure.

Noise-suppresing engine compartment have been designed either in the form of a casing which is completely separate from the vehicle body and elastically supported on the engine, or in the form of a compartment formed partly from component parts of the vehicle body or superstucture. In the latter case the required body sound insulation between the compartment walls and the engine is achieved by means of elastic engine mountings. Both of these existing arrangements inevitably involve, even with optimum design, a certain additional outlay in weight, volume and costs, and reduce accessibility of the parts of the engine which require service and maintenance.

It has further been proposed to design a "low- noise" engine by connecting those parts which are subject to direct acoustically generated vibration, namely the engine suspension complete with the cylinder head and auxiliary units mounted thereon, by means of at least one body-sound-insulating element secured to the engine mounting or suspension and to the crankcase which may be combined with the flywheel housing. The crankcase would then be provided with, or carry a sound-suppresing cowling or hood fully enclosing the cylinder head as well as the said auxiliary units. Whilst such an arrangement entails somewhat less additional outlay than a full sound proofing compartment the non-oil-wetted hood or cowling in the upper region of the engine still adds tot the overall weight, and access for repair and maintenance work is considerably impaired.

According to this invention, I provide a motor vehicle comprising an engine having an oil sump which is secured to the engine block in body-sound-insulated manner, and a fan-cooled water radiator, characterised in that a frame-mounted elastic membrane is provided between the oil sump and the vehicle boldly components so that said membrane completely encircles the oil sump at the level of its upper edge and provides an acoustic separation between the spaces respectively situated above and below the oil sump, the upper space being converted by the membrane into a sound-suppressing compartment which is closed relative to the vehicle interior by appropriate wall parts and sealing sections provided in the vehicle body, and the outflow of hot cooling air from the radiator is conducted wholly outside of the compartment.

The present invention provides for the frame-mounted elastic membrane, e.g. a rubber membrane or diaphragm, to be disposed between the oil sump and the parts of the superstructure of the bodly of the vehicle surrounding the latter, at the level of the upper edge of the oil sump, and this provides an acoustic area above and beneath the sump. The area above the sump can be conventionally enclosed within a compartment relative to the vehicle formed partly by existing component parts of the vehicle bodiy and partly by additional compartment wall and sealing strip sections. The cooling air, heated by the radiator, is conducted away completely externally of this compartment.

Such an arrangement besides affording a high degree of noise suppression, presents the chief advantage of minimal additional weight in as much as no engine casing is required. Another special advantage resides in that maintenance and service points are freely accessible as soon as the engine hood or bonnet is opened. It also provides very favourable airflow conditions for a downwardly directed outflow of cooling air away from the main fan and cooling radiator unit in the absence of a casing in the region of the oil sump.

Advantageously intermediate decks, or partitions may be provided which surround the engine in spaced relation therewith and are connected to the membrane and all round with the original vehicle body parts, whereby noise absorption is still further improved at the cost of little extra weight and expense. Naturally, such intermediate decks or partitions would be arranged in such a manner as not to impair the free accessibility of the engine.

For improving and simplifying the acoustic seal it is preferable to secure an outwardly projecting rigid frame to the oil sump which is engaged by the framemounted elastic membrane secured to the vehicle body parts.

According to a preferred embodiment of the invention the upper, sealed interior of the sound-absorbing compartment is forcibly ventilated and cooled in conventional manner by its own fan, and silencer means are provided at the air inlet and outlet openings in the compartment. In view of the fact that only comparatively small amounts of air are required for adequate ventilation and cooling of this upper space this arrangement has the advantage, as compared with those conventional constructions wherein the whole of the outílowing air stream from the radiator unit is conducted through the compartment, that the cooling air inlet and outlet openings may be of considerably smaller cross section and consequently, the silencers, to absorb the sound dispersed through these openings, may be of much smaller 'dimensions and can occupy considerably less space.

According to a further feature of this invention, the cooling air inlet in the compartment may be sited away from the out flow path of the hot air from the main radiator unit. In other words, the cooling air inlet opening for the cooling air required to cool the interior of the compartment is arranged in such a way, and at such a position that no hot air coming from the engine radiator can pass through into the interior of the compartment. This is extremely important because it prevents an un;desirable build up of heat in this area. For example, for this purpose an air intake pipe may be extended forwardly to a point beyond the radiator.

Owing to these provisions only comparatively small volumes of cooling air are needed to remove excess heat from the interior of the compartment.

In further development of this invention, the cooling air flow entering into the interior of the sound-suppressing compartment may be split up into two streams by means of baffle plates provided between the exhaust system and the remaining engine part, one of said streams being conducted to flow over the hot parts of the exhaust system and the other to cool the remaining engine surfaces. These streams may be conducted towards relatively spaced and separate outlets in the compartment This type of cooling air-flow pattern has the advantage of purposefully directed and controlled air cooling with due regard to the relatively 'different cooling requirements of the exhaust system and the less hot engine surface areas, thereby permitting economies in cooling capacity for the interior of the compartment.

Preferably, and with special advantage, the cooling airflow is discharged through a sound absorption silencer concentrically arranged around the exhaust pipe and spaced therefrom. Such disposition for the cooling air outlet from the compartment is particularly advantageous because it gives optimum consideration to acoustic as well as to thermal demands. An undesirable transmission or conduction of heat from the exhaust pipe into the compartment in the region of the leadssthrough of the exhaust is thus fully and safely prevented by comparatively simple means.

According to a preferred embodiment of this invention the compartment is closed on the topside thereof by the engine cowling or bonnet of the vehicle, thereby providing the best possible and easiest manner of obtaining access to the engine. The arrangement also has other important advantages, espçcially with regard to manufacturing and assembly costs and also with regard to overall vehicle weight.

Finally, in accordance with this invention and for an enhanced effect thereof, those parts of the vehicle body which close the vehicle interior relative to the outside and are included as component parts in the noise-suppresing compartment, e.g. the dashboard, may be provided with enhanced or improved sound-absorbing properties. Such a provision is particularly sensible in association with the siting of the noise-suppressing compartment around the upper engine parts. For, owing to the fact that the upper region of the engine compartment is converted into a surrounding closed compartment, a diffuse sound field with very high sound levels tends to be created within the compartment owing to interferences which normally do not occur in conventional engine compartments of the kind which are open on their underside and on the side next to the heat exchanger. For this reason any increased sound proofing of the vehicle body panels or walls which form part of the noisesuppressing compartment is surprisingly effective.

The invention is hereinafter more specifically explained with reference to an exemplary embodiment thereof illustrated diagrammatically in the accompanying drawings wherein: FIGURE 1 is a longitudinal view, partly in section of the front part of the motor vehicle; FIGURE 2 is a section on line II-II of Figure 1, and FIGURE 3 shows a partly-section detail of Figure 1.

Referring to the embodiment depicted in the drawings, the motor car 1 comprises an engine 2 with a variable speed gearbox and clutch 3 rigidly mounted thereon. It will be appreciated that the gearbox may also be arranged separately from the engine, e.g.

in a vehicle with a front engine and reardrive.

An oil sump 5 is secured in body-sound insulated manner, by a frame-mounted rubber element 21 to the upper part of the engine 4. This rubber elment 21 is rigidly secured to and between two supporting frame 24, 25, preferably made of metal and of relatively different sizes, the frame 24 is secured to the engine 2, and the frame 25 to the oil sump 5. Another rigid frame 6' is clamped between the oil sump 5 and the frame 25 so as to extend all round the upper periphery of the oil sump 5. Between this outwardly projecting frame 6' and the adjacent vehicle body components, a frame-mounted rubber membrane 6 is provided which co-acts with the frame 6' and with the intermediate decks or partitions 7, 7' provided in the vehicle body or vehicle structure to provide an acoustic seal separating the upper area 8 above the membrane 6 from the lower area 9 below the membrane. The frame-mounted rubber membrane 6 is connected to the partitions 7, 7' by means of flanges or collar-like abutment and bearing parts 20. Additional sealing elements 22 may be fitted to the vehicles structure to complete the acoustic seal.

The upper part 4 of the engine 2 which is situated above the membrane 6 is not provided with a separate casing for soundproofing. The effective sound proofing compartment 10 for this engine part 4 is completed by other parts of the car body, namely the dashboard 10' and the bonnet 11. These panels may be additionally soundproofed by appropriate conventional insulation linings.

An electric motor 12 drives a main fan 13 which divers the main cooling air flow through a radiator 14. The heated air then flows through the lower area 9 beneath the membrane 6 and out to the surrounding atmosphere as shown by the arrows 15. A second fan 16 which is driven by the engine, draws fresh air through a pipe 16' which extends above and forwardly of the radiator 14 through an inlet silencer 17 into the space 8 above the membrane 6. At least some of this air leaves the upper spaces through an annular clearance surrounding an exhaust silencer 19, as indicated by the arrows 19', the silencer 19 being concentric to an exhaust pipe 18.

Preferably, the cooling air in the compartment is divided into two streams, this may be achieved by suitable deflector plates.

One stream leaves via the silencer 19 whilst the other stream leaves the compartment by a separate outlet, that also having a silencer.

WHAT I CLAIM IS: 1. A motor vehicle comprising an engine having an oil sump which is secured to the engine block in body-sound-insulated manner, and a fan-cooled water radiator, charac teriseiål in that a frame-mounted elastic membrane is provided between the oil sump and the vehicle body components so that said membrane completely encircles the oil sump at the level of its upper edge and provides an acoustic separation between the spaces respectively situated above and below the oil sump, the upper space being con vertex by the membrane into a sound suppressing compartment which is closed relative to the vehicle interior by appropriate wall parts and sealing sections provided in the vehicle body, and the outflow of hot cooling air from the radiator is conducted wholly outside of the compartment.

2. A motor vehicle according to Claim 1 wherein an outwardly projecting rigid frame is secured to the oil sump and engaged by the frame-mounted elastic membrane which

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. and assembly costs and also with regard to overall vehicle weight. Finally, in accordance with this invention and for an enhanced effect thereof, those parts of the vehicle body which close the vehicle interior relative to the outside and are included as component parts in the noise-suppresing compartment, e.g. the dashboard, may be provided with enhanced or improved sound-absorbing properties. Such a provision is particularly sensible in association with the siting of the noise-suppressing compartment around the upper engine parts. For, owing to the fact that the upper region of the engine compartment is converted into a surrounding closed compartment, a diffuse sound field with very high sound levels tends to be created within the compartment owing to interferences which normally do not occur in conventional engine compartments of the kind which are open on their underside and on the side next to the heat exchanger. For this reason any increased sound proofing of the vehicle body panels or walls which form part of the noisesuppressing compartment is surprisingly effective. The invention is hereinafter more specifically explained with reference to an exemplary embodiment thereof illustrated diagrammatically in the accompanying drawings wherein: FIGURE 1 is a longitudinal view, partly in section of the front part of the motor vehicle; FIGURE 2 is a section on line II-II of Figure 1, and FIGURE 3 shows a partly-section detail of Figure 1. Referring to the embodiment depicted in the drawings, the motor car 1 comprises an engine 2 with a variable speed gearbox and clutch 3 rigidly mounted thereon. It will be appreciated that the gearbox may also be arranged separately from the engine, e.g. in a vehicle with a front engine and reardrive. An oil sump 5 is secured in body-sound insulated manner, by a frame-mounted rubber element 21 to the upper part of the engine 4. This rubber elment 21 is rigidly secured to and between two supporting frame 24, 25, preferably made of metal and of relatively different sizes, the frame 24 is secured to the engine 2, and the frame 25 to the oil sump 5. Another rigid frame 6' is clamped between the oil sump 5 and the frame 25 so as to extend all round the upper periphery of the oil sump 5. Between this outwardly projecting frame 6' and the adjacent vehicle body components, a frame-mounted rubber membrane 6 is provided which co-acts with the frame 6' and with the intermediate decks or partitions 7, 7' provided in the vehicle body or vehicle structure to provide an acoustic seal separating the upper area 8 above the membrane 6 from the lower area 9 below the membrane. The frame-mounted rubber membrane 6 is connected to the partitions 7, 7' by means of flanges or collar-like abutment and bearing parts 20. Additional sealing elements 22 may be fitted to the vehicles structure to complete the acoustic seal. The upper part 4 of the engine 2 which is situated above the membrane 6 is not provided with a separate casing for soundproofing. The effective sound proofing compartment 10 for this engine part 4 is completed by other parts of the car body, namely the dashboard 10' and the bonnet 11. These panels may be additionally soundproofed by appropriate conventional insulation linings. An electric motor 12 drives a main fan 13 which divers the main cooling air flow through a radiator 14. The heated air then flows through the lower area 9 beneath the membrane 6 and out to the surrounding atmosphere as shown by the arrows 15. A second fan 16 which is driven by the engine, draws fresh air through a pipe 16' which extends above and forwardly of the radiator 14 through an inlet silencer 17 into the space 8 above the membrane 6. At least some of this air leaves the upper spaces through an annular clearance surrounding an exhaust silencer 19, as indicated by the arrows 19', the silencer 19 being concentric to an exhaust pipe 18. Preferably, the cooling air in the compartment is divided into two streams, this may be achieved by suitable deflector plates. One stream leaves via the silencer 19 whilst the other stream leaves the compartment by a separate outlet, that also having a silencer. WHAT I CLAIM IS:

1. A motor vehicle comprising an engine having an oil sump which is secured to the engine block in body-sound-insulated manner, and a fan-cooled water radiator, charac teriseiål in that a frame-mounted elastic membrane is provided between the oil sump and the vehicle body components so that said membrane completely encircles the oil sump at the level of its upper edge and provides an acoustic separation between the spaces respectively situated above and below the oil sump, the upper space being con vertex by the membrane into a sound suppressing compartment which is closed relative to the vehicle interior by appropriate wall parts and sealing sections provided in the vehicle body, and the outflow of hot cooling air from the radiator is conducted wholly outside of the compartment.

is secured to component parts of the vehicle body.

3. A motor vehicle according to Claim 1 or 2 wherein the sealed upper space of the compartment is cooled by the forced draught of a further fan, and sound absorbing silencers are provided at the inlet and outlet openings for the cooling air in the compartment.

4. A motor vehicle according to Claim 3 wheren the cooling air inlet of the compartment is remote from the patch of the outflowing main cooling air stream which has been heated by its passage through said fancooled water radiator.

5. A motor vehicle according to Claim 3 or 4 wherein the cooling air entering into the interior of the compartment is split into two streams by the provision of deflector plates between the exhaust manifold and other engine parts, one of said streams flowing over the hot regions of the exhaust system and the other stream cooling the other engine surfaces, these streams being separately conducted to separate outlet openings in the walls of the compartment.

6. A motor vehicle according to Claim 5 wherein the wall sections of the vehicle body which close the interior of the vehicle relative to the outside comprise integrated parts of the sound-suppressing compartment.

7. A motor vehicle according to Claim 5 wherein the outlet duct for the cooling air stream comprises a sound absorber arranged around the exhaust pipe and defining an annular clearance or passage.

8. A motor vehicle according to any one of Claims 1 to 6 wherein the soundsuppressing compartment is closed off at the upper part by the bonnet of the vehicle.

9. A motor vehicle substantially as hereinbefore described with reference to the accompanying drawings.