GB2028471A

GB2028471A - Sound Insulating Housing for Internal Combustion Engine

Info

Publication number: GB2028471A
Application number: GB7929575A
Authority: GB
Original assignee: Post Office
Current assignee: Post Office
Priority date: 1978-05-31
Filing date: 1979-08-24
Publication date: 1980-03-05

Abstract

A sound insulating housing for an i.c. engine comprises front and rear sections 1 and 2 made of sound insulating panels, e.g. Al panels lined with sound insulation material. In use air is drawn into the housing through a port 15 by the cooling fan of the engine and pressure rises within the housing to discharge air into the atmosphere through a port 6. The panel 11 including the mesh-covered port 15 may include a chamber between its main faces having one or more sinuous ducts through which air flows (Figure 2, not shown). The i.c. combustion engine may form part of an electrical generator set. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to the Housing of Internal Combustion Engines This invention relates to housings for internal combustion engines particularly of electrical generator sets comprising an internal combustion engine driving a generator.

The objective of the housing is primarily to provide acoustic insulation but some means of dissipating the heat from the engine and generator must also be provided.

The present invention provides a sound insulating housing for an air-cooled internal combustion engine and any associated machinery, such housing being substantially closed and formed of sound-insulating walls at least one of which provides an inlet for cooling air and at least another one of which provides an outlet for the air having served the cooling function.

The arrangement is that in use the cooling fan of the engine draws air into the housing through the inlet thereby raising the pressure in the housing above ambient. The cooling air is warmed by the engine and discharged through the outlet by the pressure differential between the housing interior and the ambient exterior. Each wall which includes an inlet or outlet for cooling air preferably has ports respectively allowing for the inlet and outlet of air in the main faces and a chamber defined between the main faces and having one or more sinuous ducts through which air flows.

Thus in an embodiment an acoustic insulating housing comprises side and roof panels defining an enclosed space which can be positioned over a generator set resting on a supporting surface. One of the side panels provides the cooling air inlet chamber mentioned above and an adjacent panel, for example, a roof panel provides the cooling air outlet chamber.

A particular embodiment of the invention will now be described by way of example and with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a complete housing constructed in accordance with the invention; Figure 2 is an isometric view on an enlarged scale showing a panel constituting an air inlet or outlet chamber; Figures 3 and 4 are views of a cover and a main body portion of the panel of Figure 2; and Figure 5 is a section on the line 5-5 of Figure 4.

Referring initially to Figure 1 of the accompanying drawings, the housing in accordance with the invention illustrated therein comprises two rectangular box-like sections 1 and 2. The section is fabricated from metal, for example aluminium panels lined with sound insulating material which provides sound insulation. The housing overall is designated to contain a generator set, i.e. a generator and an internal combustion engine to drive the generator.

Front section 1 houses the internal combustion engine and rear section 2 houses the electrical generator. The engine and generator are thus disposed in series with the cooling fan of the engine immediately behind front panel 3 and the cooling fan of the generator immediately in front of the rear panel 4. The exhaust pipe of the motor extends vertically upwards through aperture 5 at the front of rear section 2. An aperture 6 on the roof of front section 1 allows for exit of cooling air. Aperture 6 in use is covered by a gauze and, if desired, provided with a cover 1. One side panel 11 of the front section has a gauze covered inlet port 1 5 for cooling air.

The panel 11 comprises an inner part 12 and an outer part 13. The part 12 has fixed to it side walls 14. A mesh covered aperture 1 5 providing an air flow port is provided on each part 12, 13. In the space defined between part 12 and side walls 14 opposed centrally positioned U-shaped baffles 1 6 and double U-shaped baffles 17 and 18 above and below baffles 16 define sinuous passages for cooling air flowing through the panel via ports 1 5.

Each baffle is formed of a rigid skeleton 14 and a sound absorbent outer layer 20. The arrangement is that these passages being generaliy parabolic tend to focus sound energy which has an advantageous silencing effect.

Further inlet panels may be provided specifically a panel similar to 11 described above could be incorporated on the blind side of the housing illustrated in Figure 1.

In use of the device with the motor and generator running, cool air from outside is drawn into the housing through the silencing inlet panel or panels by the cooling fans respectively of the motor and generator. As the housing fits the motor/generator set quite closely there is a consequent rise in pressure above ambient inside the housing. Cooling air is ducted onto the parts of the motor which require cooling and enters the housing atmosphere which is thus heated. The rise at ambient pressure discharges the heated air in the housing through the outlet panel and out. If necessary ducting to a wall or window outlet can be arranged.

In previous cooling arrangements air has been ducted from the cylinders themselves to an air outlet. In the present circumstances the cooling air heats the space between the housing walls and the motor. The heated air from the housing is then discharged to atmosphere by the pressure differential.

Claims

1. A housing of sound insulating panels formed for an air cooled internal combustion engine and any associated machinery, such housing being substantially closed when placed on a supporting surface and having air inlet and outlet apertures so formed in the housing, in use, air pressure in the housing rises as cooling air is drawn into the housing by the action of the air cooling fan or fans and is expelled by the difference in pressure between the interior and exterior of the housing.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or Relating to the Housing of Internal Combustion Engines This invention relates to housings for internal combustion engines particularly of electrical generator sets comprising an internal combustion engine driving a generator. The objective of the housing is primarily to provide acoustic insulation but some means of dissipating the heat from the engine and generator must also be provided. The present invention provides a sound insulating housing for an air-cooled internal combustion engine and any associated machinery, such housing being substantially closed and formed of sound-insulating walls at least one of which provides an inlet for cooling air and at least another one of which provides an outlet for the air having served the cooling function. The arrangement is that in use the cooling fan of the engine draws air into the housing through the inlet thereby raising the pressure in the housing above ambient. The cooling air is warmed by the engine and discharged through the outlet by the pressure differential between the housing interior and the ambient exterior. Each wall which includes an inlet or outlet for cooling air preferably has ports respectively allowing for the inlet and outlet of air in the main faces and a chamber defined between the main faces and having one or more sinuous ducts through which air flows. Thus in an embodiment an acoustic insulating housing comprises side and roof panels defining an enclosed space which can be positioned over a generator set resting on a supporting surface. One of the side panels provides the cooling air inlet chamber mentioned above and an adjacent panel, for example, a roof panel provides the cooling air outlet chamber. A particular embodiment of the invention will now be described by way of example and with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a complete housing constructed in accordance with the invention; Figure 2 is an isometric view on an enlarged scale showing a panel constituting an air inlet or outlet chamber; Figures 3 and 4 are views of a cover and a main body portion of the panel of Figure 2; and Figure 5 is a section on the line 5-5 of Figure 4. Referring initially to Figure 1 of the accompanying drawings, the housing in accordance with the invention illustrated therein comprises two rectangular box-like sections 1 and 2. The section is fabricated from metal, for example aluminium panels lined with sound insulating material which provides sound insulation. The housing overall is designated to contain a generator set, i.e. a generator and an internal combustion engine to drive the generator. Front section 1 houses the internal combustion engine and rear section 2 houses the electrical generator. The engine and generator are thus disposed in series with the cooling fan of the engine immediately behind front panel 3 and the cooling fan of the generator immediately in front of the rear panel 4. The exhaust pipe of the motor extends vertically upwards through aperture 5 at the front of rear section 2. An aperture 6 on the roof of front section 1 allows for exit of cooling air. Aperture 6 in use is covered by a gauze and, if desired, provided with a cover 1. One side panel 11 of the front section has a gauze covered inlet port 1 5 for cooling air. The panel 11 comprises an inner part 12 and an outer part 13. The part 12 has fixed to it side walls 14. A mesh covered aperture 1 5 providing an air flow port is provided on each part 12, 13. In the space defined between part 12 and side walls 14 opposed centrally positioned U-shaped baffles 1 6 and double U-shaped baffles 17 and 18 above and below baffles 16 define sinuous passages for cooling air flowing through the panel via ports 1 5. Each baffle is formed of a rigid skeleton 14 and a sound absorbent outer layer 20. The arrangement is that these passages being generaliy parabolic tend to focus sound energy which has an advantageous silencing effect. Further inlet panels may be provided specifically a panel similar to 11 described above could be incorporated on the blind side of the housing illustrated in Figure 1. In use of the device with the motor and generator running, cool air from outside is drawn into the housing through the silencing inlet panel or panels by the cooling fans respectively of the motor and generator. As the housing fits the motor/generator set quite closely there is a consequent rise in pressure above ambient inside the housing. Cooling air is ducted onto the parts of the motor which require cooling and enters the housing atmosphere which is thus heated. The rise at ambient pressure discharges the heated air in the housing through the outlet panel and out. If necessary ducting to a wall or window outlet can be arranged. In previous cooling arrangements air has been ducted from the cylinders themselves to an air outlet. In the present circumstances the cooling air heats the space between the housing walls and the motor. The heated air from the housing is then discharged to atmosphere by the pressure differential. Claims

2. A housing as claimed in Claim 1 wherein a panel which has an inlet or an outlet for cooling air has the ports in the main faces and a chamber defined between the main faces having one or more sinuous ducts through which air flows.

3. A housing substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

4. An electrical generator set in a housing as claimed in any of the preceding claims.