GB2465862A

GB2465862A - Motor vehicle combustion air inlet duct arrangement with a water separation pipe

Info

Publication number: GB2465862A
Application number: GB0915134A
Authority: GB
Inventors: Christopher Sachs; Tom Gurtler; Michael Pfadenhauer; Robert Meier; Gianluca Magistro; Bernd Jachowski; Stephan Machate
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 2008-12-03
Filing date: 2009-08-28
Publication date: 2010-06-09
Anticipated expiration: 2029-08-28
Also published as: GB2465862B; GB0915134D0; DE102008061538A1

Abstract

A duct arrangement for guiding combustion air to a combustion engine of a motor vehicle, in particular of a passenger vehicle, comprises an air inlet opening 3 of an air guidance duct 9 arranged in the front region of the vehicle, which duct is connected to an air filter housing 12. A means 7 for separating off water entrained by the combustion air when it is drawn in is provided in the form of a water separation pipe 7, which forms a component of the air guidance duct 9, the flow through the water separation pipe 7 passing vertically upwards and said pipe opening at the top into at least one horizontal section 8 of the air guidance duct 9. The upper edge 13 of the water separation pipe 7 extends over the lower level 14 of the region of the horizontal section 8 of the air guidance duct 9 which adjoins the water separation pipe 7. The water separation pipe 7 may have a polygonal, eg rectangular, cross-section.

Description

Duct arrangement for guiding combustion air to a combustion engine The invention relates to a duct arrangement for guiding combustion air to a combustion engine of a motor vehicle, in particular of a passenger vehicle, with an air inlet opening of an air duct arranged in the front region of the vehicle, which duct is connected to an air filter housing, and also with a means for separating off contents of water which are entrained by the combustion air when it is drawn in.

In motor vehicles in which the combustion-air inlet, also referred to as untreated air inlet, is arranged in the front region of the vehicle, the combustion air is forced into the intake system during the journey and more air can thus be supplied to the internal combustion engine. Since with this frontal air intake also water spray, in particular small water droplets mixed with the combustion air, which is produced e.g. by a vehicle moving ahead when the roadway is wet or there is heavy rain, passes into the intake system, a water separator is provided.

A duct arrangement of the type referred to first hereinbefore with a means for separating off contents of water is known for example from DE 103 29 739 Al. The intake system has the combustion-air inlet, a combustion-air line connected to the combustion-air inlet and a water separator adjoining the combustion-air line. A swirl is produced in the combustion-air line, which causes the drawn-in air in the combustion-air line to rotate.

The combustion-air line is connected to the combustion engine. The water separator has an inner pipe and an outer pipe, which are arranged coaxially to one another. Due to the coaxial construction of the water separator, the intake air flows into the subsequent components without being deflected, which means that no notable pressure losses are caused. However, the water separator is constructed in a very complex manner.

DE 32 32 583 Al describes an air guidance housing in which a' protective grid of air-deflecting plates is arranged before the air filter, so that the intake air is cleaned. It is furthermore known from this specification to provide an air cap upstream of the air filter to protect against road spray.

DE 100 29 498 Al describes a water separator arranged inside an untreated air line, in which a swirl can be produced so that the water droplets contained in the intake air can be separated off.

US-A-5, 195,484 discloses an untreated-air guidance line with a lower air inlet opening and an upper air inlet opening. If the lower air inlet opening is blocked by water entering, the air enters through the upper air inlet opening. In a low-lying section of the air duct, downstream of the low-lying air inlet opening, there is provided a drain for disposing of quantities of water which are separated out from the untreated air.

US 2005/0076871 Al describes an untreated-air intake line in which the untreated air is drawn in laterally in an upper part in the front-end space of the vehicle.

The present invention seeks to improve a duct arrangement of the type referred to first hereinbefore such that it is of particularly simple structural design and yet ensures reliable separation of water.

This is achieved in that the means for separating off the contents of water is designed as a water separation pipe, which forms a component of the air guidance duct, the flow through the water separation pipe passing vertically upwards and said pipe opening at the top into at least one horizontal section of the air guidance duct, the upper edge of the water separation pipe extending over the lower level of the region of the horizontal section of the air guidance duct which adjoins the water separation pipe. According to the invention, a deflecting element for guiding the air flow in the direction of the water separation pipe is positioned beneath the water separation pipe.

What is essential with the duct arrangement according to the invention is that the means for separating off the contents of water is designed as a water separation pipe through which the flow passes vertically upwards. This arrangement and direction of throughflow has the advantage that contents of water have to be entrained counter to the force of gravity. Furthermore, the arrangement of the upper edge of the water separation pipe above the lower level of the horizontal section of the air guidance duct in the region thereof adjacent to the water separation pipe causes the combustion air to be guided around the upper edge of the water separation pipe, with the consequence that contents of water, owing to the different specific weight of the combustion air and the water, are separated at the latest in the region of the upper edge of the water separation pipe.

Furthermore, the arrangement of the deflecting element achieves deliberate guidance of the air flow towards the water separation pipe.

Effective separation of the contents of water is thus ensured by a simple configuration of a region of the air duct as a water separation pipe, in particular in combination with the deflecting element. This water separation pipe is preferably polygonal, in particular rectangular, in cross-section.

According to an advantageous development of the invention, provision is made for the water separation pipe to be arranged in a central front region of the motor vehicle. It is thus not located in the lateral regions of the motor vehicle, but, relative to the front of the motor vehicle, in the central region thereof. This arrangement makes it possible, in a simple manner, to provide two horizontal sections of the air guidance duct which are arranged diametrically with respect to the water separation pipe. The combustion air stream thus divides at the upper outlet of the water separation pipe and passes via the two horizontal sections of the air guidance duct to an air filter or air filter housing associated with the respective section of the air guidance duct.

It is regarded as advantageous if the air guidance duct in the regions adjacent to the upper end of the water separation pipe is made rotationally symmetrical with respect to a horizontal axis. Particularly with a central arrangement of the upper end of the water separation pipe in the rotationally symmetrical section of the air guidance duct, combustion air can basically pass over into the horizontal section of the air guidance duct along the entire upper edge region.

It is deemed particularly advantageous if on one hand air reaches a radiator of the vehicle, and on the other hand combustion air reaches the air filter, through the air inlet opening arranged in the front region of the vehicle. For this, the front region of the vehicle may be designed as a spoiler which has the air inlet opening.

Due to the configuration according to the invention of the duct arrangement, thus sufficient combustion air is drawn in and simultaneously entrained contents of water are retained in the water separation pipe.

Further features of the invention will become apparent from the dependent claims, the following description of the drawings and the drawings themselves.

A preferred example of embodiment of the invention is explained in the drawings and is described in greater detail in the following description.

Fig. 1 shows a front view of a front frame of a passenger car, with the duct arrangement according to the invention for guiding combustion air to the combustion engine of the vehicle, Fig. 2 shows a three-dimensional view of the duct arrangement with air filter and frame part, in section along the longitudinal central axis of the vehicle, Fig. 3 shows the arrangement according to Fig. 2, additionally illustrated with further front attached parts of the vehicle.

Fig. 1 shows, with regard to the front end of a passenger car, a frame part 1, in which is mounted an air guidance housing 2 which is provided with an air inlet opening 3 of rectangular cross-section arranged symmetrically to the longitudinal central axis of the vehicle. This air entry opening 3 is defined at the top and bottom by shaped plate regions 4 and 5. Air passes through the air entry opening 3 in the direction of the arrows A and this air stream divides into an air stream along the arrows B to the radiator of the vehicle (not shown) and an air stream along the arrow C, which represents the combustion air for the combustion engine. In its upper region, the air guidance housing 3 is provided with an opening 6 through which the combustion air flows along the arrow C from below into a vertically arranged water separation pipe 7 which forms a component of the duct arrangement for guiding the combustion air to the combustion engine of the motor vehicle. In Fig. 2, this water separation pipe 7 is in section with respect to the vertical axis of symmetry thereof It is shown that the cross-section of the water separation pipe 7 is rectangular.

The water separation pipe 7 is formed with a slight curve, with a deflecting element 17 for guiding the air flow in the direction of the water separation pipe 7 being positioned beneath the water separation pipe 7. The deflecting element 17 serves as a flow body, which is in the form of a thin-walled, or sheet, shaped body, preferably made from a metal sheet material. The shaping of the deflecting element 17 causes the combustion air for the combustion engine to be deflected deliberately along the deflecting element 17 into the opening 6 of the water separation pipe 7. Consequently it is ensured that sufficient combustion air flows into the water separation pipe 7 in all travelling situations. Furthermore, the arrangement of the deflecting element 17 causes the combustion air in the front-end space of the vehicle to branch off from the mass of cooling air. Preferably the deflecting element 17 is positioned behind a protective frame or holding frame 18 such that the fresh air or combustion air is drawn in behind the protective frame 18. In such case, the deflecting element 17 is arranged in the lee of the protective frame 18, so that disruptive influences on the aerodynamic properties of the vehicle due to the arrangement of the deflecting element 17 do not occur. Above the deflecting element 17 there is arranged the air filter guidance duct 9 and the water separation pipe 7 through which the combustion air is guided onwards to the air filter housing 12. In accordance with the present embodiment, the deflecting element 17 is connected to the water separation pipe 7. Alternatively, the deflecting element 17 may be arranged beneath the water separation pipe 7, without indirect connection with the water separation pipe 7, such that the effect achieved by the positioning of the deflecting element 17 also occurs.

The water separation pipe 7 through which the flow passes vertically upwards opens at the top into two horizontal sections 8 of the air guidance duct marked all together with the reference numeral 9. The air guidance duct 9 in its region adjacent to the upper end of the water separation pipe 7 is formed rotationally symmetrically with respect to a horizontal axis; the rotationally symmetrical component is marked with the reference numeral 10. Downstream, a relatively flat connection piece 11 of the air guidance duct 9 adjoins this rotationally symmetrical component 10, which piece is connected to an air filter housing 12.

As can be inferred from the illustration of Fig. 2, the upper edge 13 of the water separation pipe 7 extends over the lower level, represented by the reference numeral 14, of the region of the horizontal section of the air guidance duct 9, and hence of the component 10, adjacent to the water separation pipe 7. The combustion air emerging at the top from the water separation pipe 7 is thus deflected slightly downwards into the component 10, as indicated by the arrow D. The configuration of the duct arrangement shown in Fig. 2 for one side of the vehicle applies correspondingly for the other side of the vehicle owing to the symmetrical configuration of the duct arrangement for guiding combustion air to the combustion engine resulting from Fig. 1.

Due to the configuration according to the invention of the duct arrangement, contents of water in the combustion air are separated off effectively by the water separation pipe 7, so that relatively dry combustion air is supplied to the air filter and then the combustion engine.

Fig. 3 shows the arrangement of the duct arrangement according to the embodiment of the invention described with respect to Fig. 2 in conjunction with the front part of the vehicle. Also shown is the bumper and the front panel 16 of the vehicle. The front region of the vehicle is designed as a spoiler which has the air inlet opening 3.

List of reference numerals 1 frame part 2 air guidance housing 3 air entry opening 4 plate region plate region 6 opening 7 water separation pipe 8 section 9 air guidance duct component 11 connection piece 12 air filter housing 13 upper edge 14 lower level 16 front panel 17 deflecting element 18 protective frame A arrow B arrow C arrow D arrow

Claims

Claims 1. A duct arrangement for guiding combustion air to a combustion engine of a motor vehicle with an air inlet opening of an air guidance duct arranged in the front region of the vehicle, which duct is connected to an air filter housing, and also with a means for separating off contents of water which are entrained by the combustion air when it is drawn in, wherein the means for separating off the contents of water is designed as a water separation pipe, which forms a component of the air guidance duct, the flow through the water separation pipe passing vertically upwards and said pipe opening at the top into at least one horizontal section of the air guidance duct, the upper edge of the water separation pipe extending over the lower level of the region of the horizontal section of the air guidance duct which adjoins the water separation pipe with a deflecting element for guiding the air flow in the direction of the water separation pipe being positioned beneath the water separation pipe.
2. An arrangement according to Claim 1, wherein the water separation pipe is arranged in a central front region of the motor vehicle.
3. An arrangement according to Claim 1 or 2, wherein two horizontal sections of the air guidance duct are provided which are arranged diametrically with respect to the water separation pipe.
4. An arrangement according to one of Claims ito 3, wherein the air guidance duct in the regions adjacent to the upper end of the water separation pipe is made rotationally symmetrical with respect to a horizontal axis.
5. An arrangement according to one of Claims 1 to 4, wherein the cross-section of the water separation pipe is polygonal.
6. An arrangement according to claim 5, wherein the cross-section of the water separation pipe is rectangular.
7. An arrangement according to one of Claims 1 to 6, wherein air reaches a radiator of the vehicle and combustion air reaches the air filter through the air inlet opening arranged in the front region of the vehicle.
8. An arrangement according to Claim 7, wherein the front region of the vehicle is designed as a spoiler which has the air inlet opening.
9. An arrangement according to one of claims 1 to 8, for a passenger vehicle.
10. A duct arrangement for guiding combustion air to a combustion engine of a motor vehicle, substantially as hereinbefore described with reference to the accompanying drawings.