GB2279143A

GB2279143A - Motor vehicle air conditioning

Info

Publication number: GB2279143A
Application number: GB9409492A
Authority: GB
Inventors: Wolfgang Kniele; Klaus-Dieter Knoppel; Michael Komowski; Ingo Putz
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 1993-05-27
Filing date: 1994-05-12
Publication date: 1994-12-21
Anticipated expiration: 2014-05-12
Also published as: FR2705621B1; GB9409492D0; FR2705621A1; GB2279143B

Abstract

A housing 1 for a motor vehicle heating and air conditioning system having a refrigerant evaporator 7 and an air-heating radiator 8 has an outlet opening for discharging water condensing in the evaporator and scattered through the housing interior by air flow. The base of the housing has a duct 12 which extends below the evaporator 7 and the radiator 8 and which comprises at least two inlet openings of which one opening 13 is disposed below the evaporator and one opening 16 is disposed at the lowest point below the radiator, this duct leading to an outlet opening 14. … <IMAGE> …

Description

2279143 1 A housing for a motor vehicle air-conditioning system The

invention relates to a housing for a motor vehicle air-conditioning system.

When an air-conditioning system is operating in a motor vehicle, condensation water is produced on the evaporator surfaces owing to the cooling of the air, and has to be discharged. A number of measures are known for discharging the condensation water, for example finely meshed mist eliminators and baffle walls. In this connection, the base area of the housing part accommodating the evaporator is conventionally of honeycomb construction and provided with a discharge device to which a moulded hose is connected. Arrangements of this type are disclosed for example in DE-U-82 28 162, DE-A-31 49 252 and DEC-32 29 866.

Since,, in modern vehicles, there is increasingly less structural space available for an air conditioning system and also increasingly smaller passenger cars are being equipped with air conditioning systems, it is necessary to design very compact air conditioning systems and this has a considerable effect on the cross-sections of the 2 air delivery and the air flow speed. This leads to the fact that the moisture which condenses on the cold evaporator surfaces and forms droplets of water on the output side of the evaporator is also entrained by the airstream. These droplets of water impinge on a housing wall, which deflects the air stream, and run down the housing wall. If it cannot be led off in a suitable manner. this fluid accumulating in the housing is discharged with the air stream by atomization, resulting in misting-up of the vehicle windows and thus in a safety risk.

It is therefore the object of the present invention to provide a housing for an air conditioning system having means whereby accumulated fluid is discharged.

In the case of an air conditioning system of the type in question, this object is achieved by the characterising features of Claim 1. The essential advantage of the invention resides in the fact that the fluid accumulated at various points of the air conditioning system housing is discharged by the connection of only one hose line. In this respect, the condensation water is discharged particularly rapidly and well if the duct has a

3 closed cross-sectional shape such that a suction effect is produced in the duct.

An arrangement in the case of which the duct extends at the underside of the base and thus has no effect on the inner contour of the housing parts is particularly favourable. A development which is advantageous in this respect resides in the fact that the duct is formed by a channellike depression in the housing base and a cover strip. In this connection, it is regarded as being particularly favourable in terms of cost if the channel-like depression is integrally formed in one part on the housing base. Alternatively, the duct can also be tubular and constructed integrally with the housing lower part.

If the radiators are oblique, a particularly favourable development of the configuration of the system resides in the fact that the lowest point lies in an area adjacent the evaporator and the two openings are disposed close to one another. In the case of air conditioning systems in which the radiator is disposed obliquely, the lowest point of the housing, however, can also be disposed approximately below an end of the radiator which is remote from the evaporator. In order for the condensation water in the duct to 4 run off as rapidly as possible and in order for the suction effect to be assisted, it is advantageous if the duct extends in a rectilinear manner in the portion between the inlet opening at the evaporator end and the inlet opening at the radiator end. The inlet opening at the radiator end lies between the inlet opening at the evaporator end and an outlet opening provided with a connection piece. Depending on the space available in the vehicle and the position of the connections dependent thereon, the outlet opening, or the corresponding connection piece, can be provided off-centre of the housing. Independently thereof, the inlet opening at the radiator end relative to the longitudinal direction of the air conditioning system housing - can be disposed approximately centrally or laterally offset but is in any case at the lowest point of the housing. The duct portion downstream of the inlet opening can be flat, curved or angled.

As a particulary suitable construction of the inlet openings at the radiator end it is proposed that the latter be formed by recesses which are disposed adjacent the channel-like depression and which are connected thereto by connecting ducts. In order to make the best possible use of the suction effect, it is proposed that the connection ducts extend substantially parallel to the longitudinal direction of the channel-like depression and lead into the depression at an acute angle.

A further possibility for the configuration of the inlet openings at the radiator end resides in these inlet openings being disposed in the cover strip itself. Advantageously, the cover strip is flat and completes the contour of the base in the housing lower part. In order to secure the cover strip, it is proposed that it be provided on its underside with at least one projection which engages a groove adjacent the channel-like depression.

An embodiment of the invention will be described below in further detail with reference to the drawing, in which:

Figure 1 shows in outline the section through a motor vehicle air conditioning system; Figure 2 shows a section through the lower part of the system housing; Figure 3 shows a view in the direction of the arrow III in Figure 2; 6 Figure 4 shows a section along the line W-W in Figure 3; Figure 5 shows a section along the line V-V in Figure 3; Figure 6 shows a portion of Figure 3 with the cover strip inserted; Figure 7 shows a second embodiment of an air conditioning system; and Figure 8 shows an enlarged illustration of the housing lower part in Figure 7 with a modified condensation water discharge device.

Figure 1 shows the section through an air conditioning system housing 1, this housing 1 consisting principally of three housing parts, namely a fan housing 2, a housing upper part 3 and a housing lower part 4. The separation plane between the housing upper part 3 and the housing lower part 4 is designated 5 in Figure 1. In the air conditioning system housing 1, adjoining a diffuser 6 of the fan housing 2 is disposed a refrigerant evaporator 7 which is acted upon by the entire air stream of the fan. In the housing 7 lower part 4 is disposed a radiator 8 through which the motor vehicle engine coolant flows and which - depending on the hot air requirement in the passenger compartment - is acted upon by the air stream emerging from the refrigerant evaporator 7 and delivered to outlet nozzles 9. As a result of the oblique arrangement of the radiator 8, part of the radiator projects beyond the separation plane 5 into the housing upper part As a result of the air stream cooling in the refrigerant evaporator 7, the moisture in the air stream condenses on the cool surface of the refrigerant evaporator 7. As a result thereof water droplets are produced at the output side of the refrigerant evaporator 7 and either drip downwards by virtue of gravity or - if the air stream speed is high - are entrained in the direction of the radiator 8. Since, in compact air conditioning systems, the radiator 8 is disposed in close proximity to the refrigerant evaporator 7, a baffle wall 10 is provided at which the droplets of water are deflected downwards in order to be discharged out of the air conditioning system housing 1. in the case of compact air conditioning systems and with the necessary high flow speeds, water droplets cannot 8 be prevented from being entrained by the air stream at the output side of the refrigerant evaporator 7 and being thrown against the opposite side of the housing upper part 3 or housing lower part 4 and then running down the inner wall of the housing.

At its base 11, the housing lower part 4 is provided with a duct 12 which comprises an inlet opening 13 adjacent the refrigerant evaporator 7. The duct 12 extends below the radiator 8 along the base 11 to an outlet opening 14 in a connection piece 15. At the lowest point of the base 11 below the radiator 8 is disposed an inlet opening 16 to the duct 12 through which opening the water, which is entrained by the air stream and accumulates in the housing lower part 4, can be discharged.

Figure 2 shows a section through the housing lower part 4 without the heat exchangers 7 and 8; however, the accommodating means for these heat exchangers can be seen. This illustration shows that the duct 12 is constructed integrally with the housing lower part 4 and is in the form of depression 17 in the base 11. When the housing lower part 4 is produced, the duct 12 is open towards the base 11.

9 Figure 3 shows a section of the view according to the arrow III in Figure 2. This view shows that the duct 12 on the righthand side in Figure 3 extends in a curve 18 to a terminal duct portion 27 at the end of which the outlet opening 14 lies within the connection piece 15. The inlet opening 13 of the duct 12 at the evaporator end can be seen on the lefthand side of Figure 3, as can the baffle wall 10. Adjacent the duct 12, which is in the form of a channel-like depression 17, are provided two recesses 19, 20 which are connected to the duct 12 by means of a connection duct 21, 22 in each case. The connection ducts 21, 22 extend substantially parallel to the channel-like depression 17 and lead into the latter at an acute angle. Owing to the flow direction according to the arrows 23 of the condensation water discharged in the duct 12, the fluid passing through the inlet openings 16 into the recesses 19, 20 and connection ducts 21, 22 is entrained such that a suction effect is exerted on the fluid accumulating at the lowest point of the housing lower part 4.

Figures 4 and 5 in each case show sections through the duct 12, Figure 4 corresponding to a section along the line IV-W in Figure 3 and the illustration of Figure 5 corresponding to a section along the line V-V in Figure 3. In Figures 4 and 5 the duct is provided with a cover strip 24 such that the closed cross-sectional shape of the duct 12 is produced. The cover strip 24 is flat and completes the contour of the base 11. At its lateral edges in the direction of the channel-like depression 17 the strip comprises projections 25 which engage grooves 26 adjacent the channel-like depression (Figure 5) and are retained by clamping force. The section illuszrated in Figure 4 shows that the recesses 19 and 20, which are not covered by the cover strip, thus forming the inlet openings 16, are disposed adjacent the channel- like depression 17.

Figure 6 shows a section of Figure 3, namely the area in which the inlet openings 16 are located. In Figure 6, the duct is closed by the cover device 24 and only the inlet openings 16 remain open, the dimensions of the cross-section being such that the fluid is reliably drawn out of the housing but no fluid flows out of the duct back into the housing.

Figure 7 shows the section through an air conditioning system housing 30, this housing 30 consisting of three housing parts 31, 32 and 33. The housing lower part 31 substantially occupies the lower areas of an evaporator 35 and of a radiator 36. A mixing chamber 37 with a temperature mixing flap 38 is disposed above the radiator 36 in the housing upper part 32. The third housing part 33 forms the device for accommodating the upper portion of the evaporator 35. The separation planes 40, 41 between the housing parts are selected in such a way that the tools for producing the housing parts 31, 32 and 33 can have the simplest possible shape.

At its base 34, the housing lower part 31 is provided with a duct 39 which extends below the evaporator 35 of the radiator 36. This duct 39 commences at an inlet opening 45 below the radiator 36 and leads to a connection piece 47 with an outlet opening 44 from which the condensate is further discharged. In this duct 39 is provided an inlet opening 42 which is located below the evaporator 35 and through which the condensate dripping from the evaporator 35 is delivered to the duct 39. The duct 39 is tubular and constructed integrally with the lower housing part 31.

Figure 8 shows the housing lower part 31 with a modified construction of the duct 39 which leads to the outlet opening 44. The radiator 36 rests 12 on lateral brackets 43 of the housing lower part 41 such that the water is not only discharged out of the radiator 36 at the end face and is delivered to the base 34 of the housing lower part 31 but can emerge directly at the narrow side 361 of the radiator 36, as illustrated by the arrow 46. Thus the inlet opening 45 and the inlet opening 42 are close to one another.

Figures 7 and 8 show the duct 39 extending at a slight inclination. Embodiments in which the duct is in some other direction, for example an initially vertical portion which can be followed if necessary by a further portion in any direction, also fall within the inventive concept.

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Claims

1. A housing for a motor vehicle air conditioning system, the housing being adapted to house a refrigerant evaporator and a radiator therein, and having an outlet opening for discharging water condensing in an evaporator, wherein in the base of the housing is provided a duct extending in use below the evaporator and/or the radiator and which in use comprises at least one first opening in the vicinity of the evaporator and at least one second opening at the lowest point below the radiator, and which leads to the outlet opening.

2. Housing according to Claim 1, characterised in that the duct has a closed crosssectional shape.

3. Housing according to Claim 1 or 2, characterised in that the first opening as the inlet opening is disposed in use below the evaporator and the second opening as the inlet opening is disposed in use below the radiator.

4. Housing according to Claim 1 or 2, characterised in that the second opening as the inlet opening is provided in use in the vicinity 14 of the radiator and the first opening as the inlet opening is provided in use in the vicinity of the evaporator.

5. Housing according to Claim 2, characterised in that the duct is formed of a channel-like depression in the housing base and a cover strip.

6. Housing according to Claim 5. characterised in that the channel-like depression is integrally formed in the housing base.

7. Housing according to Claim 2, characterised in that the duct is tubular and is produced integrally with a housing lower part.

8. Housing according to Claim 1, characterised in that the lowest point is disposed in use approximately below the end of the radiator remote from the evaporator.

9. Housing according to Claims 1 and 4, characterised in that the lowest point is disposed in use approximately below the end of the radiator adjacent the evaporator, and the second opening is adjacent the first opening.

10. Housing according to Claim 5.

characterised in that the duct extends in use in a rectilinear manner between the inlet opening at the evaporator end and the inlet opening at the radiator end.

Housing according to Claim 3. characterised in that in use the inlet opening at the radiator end lies between the inlet opening at the evaporator end and an outlet opening provided with a connection piece.

12. Housing according to Claim 11. characterised in that the duct extends in a rectilinear manner over its total length to the outlet opening.

13. Housing according to Claim 11, characterised in that the duct portion is curved or angled downstream of the inlet opening.

14. Housing according to Claim 5. characterised in that in use the inlet openings at the radiator end are formed by recesses which are disposed adjacent the channel-like depression and which are connected to the channel-like depression by connection ducts.

16

15. Housing according to Claim 14, characterised in that the connection ducts extend substantially parallel to the longitudinal direction of the channel-like depression and open into the depression at an acute angle.

16. Housing according to Claim 5, characterised in that in use the inlet openings at the radiator end are disposed in the cover strip.

17. Housing according to Claim 5, characterised in that the cover strip is substantially flat and comprises on its underside at least one projection which engages a groove adjacent the channel-like depression.

18. Air conditioning system comprising a housing according to any preceding claim, an evaporator and a radiator.

19. Housing for an air conditioning system substantially as described herein with reference to the accompanying drawings.

20. Air conditioning system substantially as described herein with reference to the accompany drawings.