AIR DISTRIBUTION APPARATUS FOR A VEHICLE AIR CONDITIONING SYSTEM

Abstract: Air distribution apparatus (1) for a vehicular air conditioning system, includes adjacently arranged flow control elements (2,3), the flow control elements having respective open portions and respective closed portions, and being movable relative to a plurality of output zones. Air is directed through the open portions of the elements to permit varying air output configurations dependent upon the orientation of the open and closed portions of the flow control elements. The apparatus may include an inner cylindrical flow control element (3) nested within an outer cylindrical flow control (2) element the open portions being defined through respective circumferential walls.

Description: AIR DISTRIBUTION APPARATUS FOR A VEHICLE AIR CONDITIONING SYSTEM The present invention relates to an air distribution apparatus for a vehicular air conditioning system. Air conditioning systems for vehicular application can vary in complexity from extremely simple arrangements to more complex systems. An example of such a simple arrangement is an arrangement utilising an electric heater as the only device to modify air condition in response to user intervention. An example of a more complex system is a system employing air cooling, air heating and air humidity control in response to set user requirements and using sensors and feedback control . All systems from the simple to the complex require an air distribution arrangement to distribute the conditioned air to the required zones of the passenger compartment in accordance with user preference. The purpose of an automotive climate control system is to provide the interior of the vehicle with conditioned air (heated, cooled, de-humidified) for occupant comfort and driver visibility (de-misting, de-icing) . This is achieved by first drawing air from outside the vehicle and then conditioning the air and distributing into the cabin via three main channels. These channels supply the air to specific zones (screen, face vents and foot vents) . It is the task of the air distribution system to direct and proportion the air between these channels in accordance with the mode setting selected by the driver i.e. vent, foot, defrost, etc. There is increasing pressure on system designers to observe trends to reduce costs, house system components in a decreasing/minimal space envelope, and devise systems employing fewer component parts. Additionally, design emphasis is shifting toward modular design, particularly in the 'Cockpit' area. The 'Cockpit' refers to the area of the vehicle interior in front of the driver/front passenger. This will typically incorporate dashboard mouldings, air conditioning unit, steering column, pedals, structural member, electronic control components, audio, and the like. In view of the above considerations (among others) an improved arrangement has been devised. According to a first aspect, the present invention provides air distribution apparatus for a vehicular climate control/air conditioning system, the apparatus comprising a plurality of adjacently arranged flow control elements, the flow control elements having one or more respective open portions and one or more respective closed portions, the flow control elements being movable relative to a plurality of output zones, air being directed through the open portions of the elements to permit varying air output configurations dependent upon the orientation of the open and closed portions of the flow control elements. An inner cylindrical flow control element is preferably nested within an outer cylindrical flow control element the open portions preferably being defined through respective circumferential walls. The open portions of the adjacent flow control elements are preferably configured to overlap and lie adjacent one another dependent upon movement of one or both of the flow control elements. The adjacently arranged flow control elements may be moved independently of one another. Particularly in more complex systems (for example using electrical actuators and 'intelligent' control) the movement of the flow control elements may be coordinated such that they move simultaneously or in sequence to positions in response to user input demands . The apparatus is beneficially arranged to be re- configurable to selectively direct air to one or more output zones (preferably a plurality of output zones) including a passenger footwell zone, passenger cabin vents and a windscreen zone . The adjacently arranged flow control elements are preferably movable rotatably, preferably about a common rotational axis. The adjacently arranged flow control elements are preferably driven by respective drive shafts, one of the drive shafts desirably extending along a hollow internal passage of the other. The adjacently arranged flow control elements are therefore preferably independently driven by respective rotatable drive shafts, each drive shaft beneficially carrying a respective drive gear. The respective drive gears for each shaft are preferably arranged facing one another. An inner cylindrical flow control element is preferably nested within an outer cylindrical flow control element, the open portions being defined through respective circumferential walls, respective substantially coaxial drive shafts preferably connecting with respective cylinder end portions of the flow control elements. Air is preferably .directed into the apparatus in a substantially radial direction through respective open portions of the cylinder walls of the nested flow control elements . The opposed ends of the nested cylindrical arrangement are preferably substantially closed. The output zones are beneficially arranged in a circumferential sequence about the outer cylindrical flow control element. Zone dividers are beneficially positioned to demark the output zones, the dividers preferably comprising walls extending radially outwardly. The dividers defining the output zones are preferably fixed such that the flow control elements move relative thereto. The size of operational open portions and closed portions of the flow control elements correspond substantially to the access regions into the output zones immediately adjacent the apparatus. The operational output zones may be selected as required; the arrangement beneficially provides for air to be distributed to two or more (more preferably three or more) output zones simultaneously. In one embodiment of the invention an inner cylindrical flow control element is nested within an outer cylindrical flow control element the open portions being defined through respective circumferential walls, one of the flow control elements having a single closed portion and a remainder substantially open portion, the other having a plurality of open portions. Where the apparatus comprises an inner cylindrical flow control element nested within an outer cylindrical flow control element conditioned air is preferably input into the arrangement in a radial direction through the cylinder walls of the flow control elements. The invention will now be further described, in a specific embodiment, by way of example only and with reference to the accompanying drawings in which: Figures la to le are schematic representations of various positional orientations of inner and outer cylindrical drums comprising the apparatus according to the invention; Figures 2a to 2e are schematic perspective views corresponding to the drum orientation of Figures la to le; Figure 3 is a perspective view of a system including baffles/dividers internally of the drums; and Figure 4 is a perspective cut-away representation of a concentric cylindrical drum arrangement according to the invention. Referring to the drawings, and initially to Figure 4 in particular, there is shown a general arrangement of air distribution apparatus 1 comprising an outer cylinder 2 and an inner cylinder 3 received within the outer cylinder 2 such that the side walls of each are closely adjacent or contiguous. Internal cylinder drum 3 has a mainly open side wall 30 with bracing struts 4 connecting with transverse struts 5 and peripheral rim 6. Inner cylinder drum 3 includes a closed (solid) wall portion 7 as will be described in greater detail hereafter. The outer drum 2 has closed portions 8, 9 the remaining notional outer wall being open (29) . Outer drum 2 is connected via base 10 to hollow drive shaft 11 upon which is mounted a control gear 12. The outer drum 2 is driveable to rotate about its longitudinal axis by means of an electrical actuating motor (not shown) turning control gear 12. Connecting struts 5 of inner drum 3 connect with a drive shaft 13 extending along the interior of hollow shaft 11 and having a projecting portion to which is mounted a control gear 14. When the control gear 14 is driven by electric actuator motor, shaft • 13 and inner drum 3 are caused to rotate about the longitudinal axis of the concentric nested drums 2 , 3. As the drums 2, 3 are rotated in response to the actuator motors, various configurations of overlapping of closed portions 7, 8, 9 and openings 29, 30 are permitted. The dimensions of the closed portions 7, 8, 9 and openings 29, 30 are arranged to, in certain orientations, either fully block, fully open or partially open a series of vents defined into output zones, spaced radially about the cylinder arrangement. Output zones 20, 21, 22, 23 are delimited by radially extending baffles 15, 16, 17, 18, 19. Air outputting into respective zones 20, 21, 22, 23 is then ducted to the relevant vehicle cockpit output device as follows : Zone 20 - left-hand vent Zone 21 - screen vent Zone 22 - right-hand vent Zone 23 - feet A further radial zone 24, defined between baffles 19, 18, acts as the air input into the rotary drum arrangement . As shown in Figures la to le and correspondingly arranged Figures 2a to 2e, the various overlapping configurations intrinsic to this arrangement and the highly versatile nature of the combined action of the concentrically arranged drums permits a wide variety of output configurations to be conveniently achieved. These may be summarised as follows: Vent Mode (Figures la and 2a) The closed segments 8, 9 on the outer drum 2 cover the screen and foot apertures, and the closed segment on the inner drum also covers the screen aperture. This configuration will allow air to be supplied to the left- hand vent (L H) and right-hand (R H) vent distribution zones only. Vent/Foot Mode (Figures lb and 2b) By rotating the outer drum 2 by 36° anti -clockwise, the closed segments 8, 9 partly cover the screen, foot, and vent apertures. The inner drum has not been moved, hence the closed segment 7 will still cover the aperture to the screen zone 21. This configuration will allow air to be supplied to the LH and RH vent zones 20, 22 and the foot zone 23. Foot Mode - (Figures lc and 2c) By rotating the outer cylinder drum 2 by 36° anti-clockwise, the closed segments 8,9 will now cover the LH and RH vent zone apertures. The inner cylinder drum 3 has not been moved, hence the closed segment will still cover the screen zone 21. This configuration will allow air to be supplied to the foot zone 23 only. ' Foot/Defrost Mode - (Figures Id and 2d) The outer cylinder drum 2 has not been moved, hence the closed segments 8,9 will still cover the LH and RH vent zones 20, 22. Rotating the inner cylinder drum 3 by 72° clockwise, the closed segment 7 will now cover the RH vent aperture. This configuration will allow air to be supplied to the foot and screen zones 21, 23. Defrost Mode - (Figures le and 2e) The outer cylinder drum 2 has not been moved, hence the closed segments 8, 9 will still cover the LH and RH vent zones 20, 22. Rotating the inner cylinder drum 3 by 72° clockwise, the closed segment 7 will now cover the foot zone 23. This configuration will allow air to be supplied to the screen zone 21 only. The configurations shown in this scheme are indicative of a typical application only. They are not intended to show precise or exclusive positional information. Each outlet channel can be adjusted infinitely between fully open and fully closed, to achieve the required flow regime. The advantage of a multiple concentric drum system is that a far more complex valving/metering regime can be obtained. Depending on how many drums are used and how many channels (zones) are being fed. An infinite number of-metering configurations can be achieved. It is clear, however, that a large number of drums would cause significant problems with sealing and control For this reason, it is anticipated that for up to 4 or 5 outlet channels, 2 drums should be sufficient. The present invention provides accurate metering for a complex air distribution system, with fewer component parts than prior art systems . By having a radial entry for the incoming air (from zone 24 in Figures 1 and 2) , rather than an axial entry, the 'concentric drum system' is more compact and therefore particularly suitable for future modular development in the automotive/vehicular field. Because each drum can be positioned independently of the others, the arrangement ideal for use in self-calibrating systems i.e. systems which are constantly monitoring temperatures and airflow etc and re-adjusting itself to achieve set target values. Because of rigid links and cams etc prior art air directing door systems do not lend themselves to such "intelligent system" applications.

Claims: Claims : 1. Air distribution apparatus for a vehicular air conditioning system, the apparatus comprising a plurality of adjacently arranged flow control elements, the flow control elements having one or more respective open portions and one or more respective closed portions, the flow control elements being movable relative to a plurality of output zones, air being directed through the open portions of the elements to permit varying air output configurations dependent upon the orientation of the open and closed portions of the flow control elements. 2. Air distribution apparatus according to claim 1, wherein an inner cylindrical flow control element is nested within an outer cylindrical flow control element the open portions being defined through respective circumferential walls. 3. Air distribution apparatus according to claim 1 or claim 2, wherein the open portions of the adjacent flow control elements may be positioned to overlap or lie adjacent one another upon movement of one or both of the flow control elements. 4. Air distribution apparatus according to claim 3, wherein the open portions of the adjacent flow control elements may be positioned to overlap or lie adjacent closed portions of the other upon movement of one or both of the flow control elements. 5. Air distribution apparatus according to any preceding claim, wherein the adjacently arranged flow control elements are movable independently. 6. Air distribution apparatus according to any preceding claim, wherein the adjacently arranged flow control elements are movable rotatably. 7. Air distribution apparatus according to claim 6, wherein the adjacently arranged flow control elements are rotatable about a common rotational axis. 8. Air distribution apparatus according to claim 7, wherein the adjacently arranged flow control elements are driven by respective drive shafts, one of the drive shafts extending along a hollow internal passage of the other. 9. Air distribution apparatus according to any preceding claim, wherein the adjacently arranged flow control elements are independently driven by respective rotatable drive shafts, each drive shaft carrying a respective drive gear. 10. Air distribution apparatus according to claim 9, wherein the respective drive gears for each shaft are arranged facing one another. 11. Air distribution apparatus according to any preceding claim, wherein an inner cylindrical flow control element is nested within an- outer cylindrical flow control element the open portions being defined through respective circumferential walls, respective substantially coaxial drive shafts connecting with respective cylinder end portions of the flow control elements . 12. Air distribution apparatus according to any preceding claim, wherein an inner cylindrical flow control element is nested within an outer cylindrical flow control element the open portions being defined through respective circumferential walls, air being directed into the apparatus in a substantially radial direction through respective open portions of the cylinder walls of the nested flow control elements. 13. Air distribution apparatus according to any preceding claim, wherein an inner cylindrical flow control element is nested within an outer cylindrical flow control element the open portions being defined through respective circumferential walls, the opposed ends of the nested cylindrical arrangement being substantially closed. 14. Air distribution apparatus according to any preceding claim, wherein an inner cylindrical flow control element is nested within an outer cylindrical flow control element the open portions being defined through respective circumferential walls, the output zones being arranged in a circumferential sequence about the outer cylindrical flow control element. 15. Apparatus according to claim 14, wherein zone dividers are positioned to demark the output zones, the dividers comprising walls extending radially outwardly. 16. Apparatus according to claim 14 or claim 15, wherein the dividers defining the output zones are fixed such that the flow control elements move relative thereto. 17. Apparatus according to any preceding claim, wherein the size of operational open portions and closed portions of the flow control elements correspond substantially to the access regions into the output zones immediately adjacent the apparatus. 18. Apparatus according to any preceding claim, wherein an inner cylindrical flow control element is nested within an outer cylindrical flow control element the open portions being defined through respective circumferential walls, one of the flow control elements having a single closed portion and a remainder substantially open portion, the other having a plurality of open portions. 19. Air distribution apparatus for a vehicular air conditioning system, the apparatus comprising an inner cylindrical flow control element nested within an outer cylindrical flow control element the flow control elements having one or more respective open portions and one or more respective closed portions, the flow control elements being rotatable relative to one another, air being directed to one or more output zones through the open portions of the elements to permit varying air output configurations dependent upon the orientation of the open and closed portions of the flow control elements, wherein air is input into the arrangement in a radial direction through the cylinder walls of the flow control elements.

Inventors: NELSON MARK, NELSON, MARK
Applicants: LLANELLI RADIATORS LTD, NELSON MARK, LLANELLI RADIATORS LIMITED, NELSON, MARK
Application year: 2001
Main classification: B60H1
IPC codes: B60H1, F16K11