Device and method for fan-based deicing of air door assemblies

Abstract

A motor vehicle component assembly including an air door assembly having an air door frame, on which at least one air door is movably arranged for adjusting the area through which air can flow in an air flow opening; a heat source that can include a coolant heat exchanger and/or an internal combustion engine; a blower which in the rated operating mode generates an operating air flow from the air door assembly toward the heat source; a sensor device that detects at least one operating variable and/or one state variable of the motor vehicle component assembly, and/or one state variable of the area surrounding the motor vehicle component assembly, and on the basis of this detection, outputs at least one detection variable; and a control device, which is configured to control the operation of the blower, the control device being configured to operate the blower, based on the at least one detected variable, in a deicing mode that is different from the rated operating mode, in which the blower generates a deicing air flow from the heat source toward the air door assembly.

Claims

1. A vehicle component assembly comprising: an air door assembly having an air door frame, on which at least one air door is movably arranged for adjusting the area through which air can flow in an air flow opening formed in the air door frame, the air door assembly further including at least one door actuator operable connected to the at least one air door to adjust the at least one air door relative to the air door frame; a heat source in the form of a coolant heat exchanger of a coolant circuit for an internal combustion engine; a blower which in a rated operating mode generates an operating air flow from the air door assembly toward the associated heat source; at least one temperature sensor operable to detect an ambient temperature; a drive current sensor operable to detect a drive current of the at least one door actuator; and wherein the blower is switchable between the rated operating mode and a deicing mode that is different from the rated operating mode wherein in the deicing mode the blower generates a deicing air flow from the heat source toward the air door assembly to deice the air door assembly, wherein the blower switches to the deicing mode when both the drive current exceeds a predetermined current threshold and the ambient temperature drops below a predetermined temperature threshold regardless of the position of the at least one air door.

2. The motor vehicle component assembly according to claim 1, wherein when the blower switches to the deicing mode, the direction of rotation of a fan wheel of the blower is reversed.

3. A motor vehicle having a motor vehicle component assembly according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which forms a part hereof and wherein:

(2) FIG. 1 is a rough schematic side view of the front end of a motor vehicle with the air door assembly iced up, and

(3) FIG. 2 is the rough schematic side view of FIG. 1 after deicing of the air door assembly.

DESCRIPTION OF PREFERRED EMBODIMENTS

(4) Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only and not for the purpose of limiting the same, FIG. 1 shows a rough schematic diagram of the front end of a motor vehicle, designated generally as 10. Front end 10 of the motor vehicle comprises a front wheel 14, an engine hood 16, and an underbody 18. In an engine compartment 20 formed in the vertical direction between underbody 18 and engine hood 16, an internal combustion engine 22 is accommodated in a manner that is known per se.

(5) Internal combustion engine 22 is likewise cooled in a manner that is known per se by a liquid coolant, which passes through the engine block of internal combustion engine 22 and emerges therefrom heated. The heated coolant is then fed to a coolant heat exchanger 24, where it is cooled convectively by a flow of air. The cooled coolant is then returned in a circuit to the engine block of internal combustion engine 22, from which it extracts heat, becoming heated itself, and is returned once again to coolant heat exchanger 24, where it releases this heat to the surrounding air.

(6) A cooling blower 26, which includes a fan wheel 28 and a fan drive 30, is typically located between coolant heat exchanger 24 and internal combustion engine 22, or at least behind coolant heat exchanger 24 in the vehicle longitudinal direction L. Fan drive 30 is generally a rotary electric motor.

(7) In vehicle longitudinal direction L (which is the direction leading from the vehicle front toward the vehicle rear), an air door assembly 32 is positioned in front of coolant heat exchanger 24. Vehicle longitudinal direction L is parallel to the drawing plane of FIG. 1.

(8) Air door assembly 32 comprises an air door frame 34, shown only schematically, which surrounds an air flow opening 36 that extends orthogonally and parallel to the drawing plane of FIG. 1. On air door frame 34, a plurality of air doors 38 are arranged substantially parallel to one another and extending through air flow opening 36. For the sake of clarity, only two air doors 38 are provided with reference symbols.

(9) Air doors 38 are each arranged on air door frame 34 so as to pivot about a pivot axis that is orthogonal to the drawing plane of FIG. 1. In the exemplary embodiment shown, air doors 38 can be combined into an upper air door group 40 and a lower air door group 42. Air doors 38 belonging to a common air door group 40 or 42 are coupled to enable collective pivoting movement about their respective parallel pivot axes. It is also possible for all of air doors 38 to be coupled for collective pivoting movement. The coupling for the purpose of pivoting movement is not shown in FIG. 1.

(10) Air door assembly 32 comprises at least one actuator 44, by means of which air doors 38 can be driven in an adjusting movement about their respective pivot axes. Each air door group 40 and 42 can have its own actuator to allow the air doors 38 of one air door group to be moved separately from the air doors 38 of the other air door group.

(11) The operation of actuator 44 of air door assembly 32 is controlled via an air door control device 46.

(12) The operation of cooling blower 26 is controlled via a control device 48. Each of control devices 46 and 48 can be connected in terms of signal transmission to a vehicle controller (not shown in FIG. 1).

(13) Air door assembly 32, coolant heat exchanger 24 and/or internal combustion engine 22 as heat source(s), cooling blower 26, and control device 48 together form a motor vehicle component assembly 50 as claimed.

(14) In the rated operating mode, which is the normal operating mode of cooling blower 26 for the majority of its operating time, cooling blower 26 generates an air flow Ln that flows in the direction from air door assembly 32 through coolant heat exchanger 24, if necessary up to internal combustion engine 22. When the vehicle is moving, cooling blower 26 may be operated as a supplement to the air stream flowing in the same direction to intensify convective cooling at the coolant heat exchanger 24, and when the vehicle is stationary, the cooling blower may be operated as the sole source of convective cooling of the coolant in the coolant heat exchanger 24.

(15) In FIG. 1, air door assembly 32 is immobilized due to icing, for instance by a layer of ice 52 that has formed on the front end of engine hood 16 and in front of a radiator grille. As a result, air doors 38 of air door assembly 32 cannot be moved, and therefore, the cross-sectional area of air flow opening 36 through which air is able to flow undesirably cannot be adjusted.

(16) Control device 48 can be connected via a data line 54 to at least one temperature sensor 56, which detects the temperature of the environment outside the vehicle and transmits this temperature via line 54 to control device 48.

(17) In addition, air door control device 46 can detect the drive current flowing through actuator 44 when actuator 44 is triggered for the purpose of moving air doors 38, and can transmit this drive current via a data line 58 to control device 48.

(18) If the drive current detected by air door control device 46 exceeds a predetermined threshold for drive current, while at the same time, the ambient temperature detected by temperature sensor 56 is below a predetermined threshold for temperature, control device 48 will conclude that air door assembly 32 is iced up, and will initiate deicing of air door assembly 32.

(19) For this purpose, fan drive 30 is actuated via data line 60 to drive fan wheel 28 in the direction of rotation opposite the direction used in the rated operating mode of fan drive 30, causing cooling blower 26 to generate an air flow Le that flows through coolant heat exchanger 24 to air door assembly 32. This allows the air to draw heat from coolant heat exchanger 24, and thus heated, to travel over air doors 38, air door frame 34, actuator 44, etc. thereby heating said components. This causes ice layer 52 to melt.

(20) With the preferred spatial arrangement, implemented in many vehicles, of air door assembly 32, coolant heat exchanger 24, cooling blower 26 and internal combustion engine 22 in the vehicle longitudinal direction L, if internal combustion engine 22 contains residual heat, then during the deicing mode shown in FIG. 1, air which has already been heated by internal combustion engine 22 can be drawn in by cooling blower 26 and moved through coolant heat exchanger 24 to air door assembly 32.

(21) The deicing mode proposed in the present application thus advantageously functions even when the vehicle is standing still and internal combustion engine 22 is switched off, if residual heat from previous operation remains stored in the coolant of the vehicle's coolant circuit and/or in internal combustion engine 22, and can be used for heating and deicing air door assembly 32 according to the above-described deicing mode of cooling blower 26.

(22) FIG. 2 shows the deiced air door assembly 32 and the rated operating mode of cooling blower 26.

(23) While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments, and equivalences thereof, can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Furthermore, the embodiments described above can be combined to form yet other embodiments of the invention of this application. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.