AIR VALVE SYSTEM AND METHOD FOR DIAGNOSING THE FUNCTIONALITY OF AN AIR VALVE SYSTEM

Abstract

Air flap system (20) for controlling the air access into a motor vehicle, comprising - an actuator (30), - at least one group of air flaps (32, 34), each of which is arranged to pivot between an open position and a closed position, is acted upon in a first direction of rotation by means of a spring (36) and can be pivoted by the actuator (30) against the spring actuation in a second direction of rotation opposite to the first direction of rotation, and - a diagnostic system (40) which is designed to determine at least one parameter of the actuator (30) required for pivoting the air flaps (32, 34) in the second direction of rotation and to derive the functionality of the air flap system (20) from the at least one parameter, characterized in that each spring (36) is designed and / or arranged such that it does not exert any force in the first direction of rotation during part of the pivoting in the second direction of rotation.

Description

[0001] The present invention relates to an air flap system according to claim 1 for controlling the air access into a motor vehicle, a method according to claim 5 for diagnosing the functionality of an air flap system, and a motor vehicle equipped with such an air flap system according to claim 9.

[0002] Modern vehicles are equipped with air flap systems for aerodynamic reasons, allowing for active control of airflow through adjustable flaps located in the radiator grille area. Improving vehicle aerodynamics is one way to reduce fuel consumption and, consequently, CO2 emissions. For example, closing the air flaps can create an air cushion in front of the radiator grille, preventing or at least reducing air turbulence. Conversely, for obvious reasons, the flow of air or fresh air into the engine compartment or passenger compartment must be possible at all times. The air flaps are typically adjusted by an electric actuator.

[0003] EP 2 409 872 B1 discloses and describes an air flap unit with pivotable air flaps arranged in front of a vehicle radiator. These flaps can be pivoted together between an open and a closed position by means of an electric actuator, and a spring is provided to bias the air flaps into the open position. The pivoting of the air flaps into their closed position by the actuator thus occurs against the spring force. The electric actuator is equipped with a fault detection device that monitors the current induced by the actuator during a spring-driven pivoting into the open initial position.

[0004] DE 10 2011 004 169 A1 shows and describes an air flap arrangement in front of a radiator of a motor vehicle, in which the individual louvers are pivotable between an open position and a closed position and are pre-tensioned into the closed position by means of a leg spring.

[0005] DE 10 2012 103 464 A1 relates to an actuator for an air passage device for engine cooling of a vehicle with a control unit for the actuator, which is designed to detect and evaluate an operating parameter, for example an electric current, of a drive motor of the actuator for the purpose of fault analysis.

[0006] With the current state of technology, the functionality of the air flap system's control unit cannot be verified using a self-diagnostic (on-board diagnostics or OBD) method. In other words, the existing air flap system control unit is not OBD-compliant. However, OBD compliance is mandatory in some national markets by regulatory authorities because it is emissions-related and therefore essential for achieving certain climate targets.

[0007] The present invention is based on the objective of providing an improved OBD-compliant air flap system for controlling the air access to a motor vehicle and an OBD-compliant method for diagnosing the functionality of such an air flap system.

[0008] This problem is solved with an air flap system according to claim 1 and a method according to claim 5. Advantageous further developments of the invention are the subject of the dependent claims.

[0009] An air flap system according to the invention for controlling the air supply to a motor vehicle comprises an actuator and at least one group (often two groups) of air flaps. Each air flap is pivotably arranged between an open position and a closed position and is acted upon by a spring in a first direction of rotation. Each air flap can be pivoted by the actuator against the force generated by the spring – about the same axis of rotation – in a second direction of rotation, which is opposite to the first direction of rotation. Furthermore, a diagnostic system is provided, which is designed to determine at least one parameter of the actuator required for pivoting the air flaps in the second direction of rotation and to derive at least one parameter from this to assess the functionality of the air flap system and to diagnose it.The air flap system is characterized by the fact that each spring is designed and / or arranged in such a way that it does not exert any force in the first direction of rotation during part of the pivoting in the second direction of rotation.

[0010] Since the spring tension is detected by determining the parameter required for the actuator's function and can be evaluated by the diagnostic system for diagnostic purposes, it is possible to create a simple and cost-effective OBD-compliant air flap system. Particularly good diagnostic capability is achieved by designing or arranging each of the springs, also known as tension springs, in such a way that during the initial part of the air flap's pivoting movement in the second direction, they do not exert any tension in the first direction of rotation. This tension only comes into play in a second, subsequent part of the pivoting movement. In particular, by comparing the required parameter in the first and second parts, it is then easy to diagnose whether the air flap system is functioning correctly or not.

[0011] A method according to the invention for diagnosing the functionality of an air damper system can be used in an air damper system comprising an actuator and at least one group of air dampers, each of which is arranged to pivot between an open position and a closed position, is acted upon by a spring in a first direction of rotation and can be pivoted by the actuator against the spring actuation in a second direction of rotation opposite to the direction of rotation.The method according to the invention comprises the following steps: The air flaps are pivoted – against the spring action – in the second direction of rotation, wherein during a first, initial part of the pivoting movement of the air flaps in the second direction of rotation no action is yet exerted in the first direction of rotation, but this action only comes into play in a second, subsequent part of the pivoting movement; a diagnostic system determines at least one parameter of the actuator that is required for pivoting the air flaps in the second direction of rotation, and the diagnostic system derives the functionality of the air flap system from the at least one parameter, or in other words, diagnoses its functionality.This achieves the same advantages as with the air flap system according to the invention: A simple and cost-effective OBD-compliant air flap system can be created, with which its functionality can be reliably diagnosed.

[0012] According to an advantageous embodiment, the air damper system according to the invention is characterized in that the actuator is formed by an electric motor and the at least one parameter is based on the current value required for the operation of the actuator during pivoting of the air dampers in the second direction of rotation. This at least one parameter can be the current value itself, a voltage drop across a corresponding measuring resistor, another correlated quantity, or any combination thereof. Particularly when the current value itself is used, a very simple and cost-effective system is provided, since the current value for the actuator is generally already being measured and, according to the invention, can additionally be used for diagnosing the functionality of the air damper system.For example, if an air damper is defective and does not pivot with the others, the current required for pivoting decreases accordingly, and the diagnostic system can deduce (and, if necessary, immediately signal to a user audibly or visually) that the function of the air damper system is impaired. This avoids the need for additional, potentially complex sensors to monitor the functionality of the air damper system. Alternatively, the actuator could be a pneumatic system, in which case at least one parameter would be, for example, the pressure required in the relevant line of the system for actuating the air dampers.

[0013] A particularly cost-effective further development of the invention is possible if each of the actuation springs is formed from a simple torsion spring, since such torsion springs are very cost-effective and at the same time work reliably.

[0014] It can be advantageous if each group of air dampers is connected to a drive rod that is articulated to a drive shaft of the actuator. For example, one drive rod and one drive rod can be provided to the left and right of a centrally located actuator, with the air dampers attached to them.

[0015] According to an advantageous embodiment of the method according to the invention, in the embodiment in which the actuator is an electric motor, the current value of the electric motor during its operation to pivot the air flaps in the second direction of rotation is used as a parameter on which the diagnosis of the functionality of the air flap system is based.

[0016] A particularly simple and precise determination of the functionality of the air flap system is possible when the second direction of rotation of the pivoting movement is selected to correspond to the opening movement of the air flaps. This is advantageous because the opening movement is then supported by the ram air pressure present during driving, and the counterforce generated by the actuation springs requires a higher force from the actuator, thus enabling a more precise measurement.

[0017] The aforementioned problem is also solved by a motor vehicle equipped with the aforementioned air flap system. Accordingly, the same or similar advantages arise as those described above, which is why, to avoid repetition, reference is made to the preceding explanations in connection with the device according to the invention.

[0018] Some advantageous embodiments of the invention are explained below by way of example with reference to the figures. They show: Fig. 1 a schematic representation of a first embodiment of the air flap system according to the invention with vertically arranged air flaps, Fig. 2 an enlarged view of part of the air flap system of Fig. 1, Fig. 3A - 3C an enlarged view of another part of the air flap system of Fig. 1 in cross-section, Fig. 4 a representation of the measured currents during the pivoting of the air flaps of the first embodiment, Fig. 5 a schematic representation of a second embodiment of the air flap system according to the invention with horizontally arranged air flaps, Fig. 6 An enlarged view of part of the air flap system of Fig. 5, Fig. 7A - 7C a representation of another part of the air flap system of Fig. 5, and Fig. 8 a comparative representation of the measured currents during the pivoting of the air flaps with a fully functional air flap system and with different degrees of malfunction.

[0019] Orientation terms such as "left", "right", "top" and "bottom", as well as "vertical" and "horizontal", refer to an arrangement as is usually the case with motor vehicles located on a horizontal surface, without this being intended to represent a restriction.

[0020] In Fig. Figure 1 shows a first embodiment of an air flap system 20 according to the invention, which is typically installed in the area of ​​the radiator grille of a motor vehicle, in a perspective view from the front. An actuator 30, designed as an electric motor in this embodiment, is arranged in a central position. To the right of the actuator 30 is a first group of air flaps 32, each connected to a drive rod 33, which in turn is articulated to a drive shaft 38 of the actuator 30. To the left of the actuator 30 is a second group of air flaps 34, each connected to a drive rod 35, which in turn is articulated to the drive shaft 38 of the actuator 30. A diagnostic system 40, shown only schematically, whose function will be explained later, is connected to the actuator 30. For a better illustration of the system mechanics, the right part of Fig. 1 enlarged in Fig. 2 shown.

[0021] In the Fig. Figures 3A-3C show a further essential detail of the air damper system 20 in cross-section. Each air damper 32 is pivotably mounted about a pivot axis 37. Each air damper 32 also has a stop pin 39, the function of which will be described later. A pair of stop pins 31a and 31b are provided at an abutment 31, each assigned to a specific air damper 32. A torsion spring 36 is clamped between each pair of stop pins 31a, 31b such that one leg of the torsion spring 36 rests against the stop pin 31a, while the other leg rests against the stop pin 31b. When the actuator 30 is moved via the drive rod 33 (both not shown) from the point in Fig. In the position shown in 3A (corresponding to the closed position), the air flaps 32 are pivoted (here clockwise), rotating about their respective axis of rotation 37. After a certain time, the contact bolt 39 of each air flap 32 comes into contact with a leg of the associated leg spring 36. This position is in Fig. Figure 3B shows that when the actuator 30 pivots the air flaps 32 further, it must work against the force exerted by the respective springs 36 until it moves the air flaps 32 into the position shown in Figure 3B. Fig. 3C has brought the final position shown - which corresponds to the open position of the air flaps 32.

[0022] If the current required by the actuator 30 to perform the pivoting of the air flaps 32 is measured during this pivoting, the result is given in Fig. 4. The course shown, in which the measured values ​​at the points in the Fig. Positions 3A - 3C are designated separately.

[0023] In Fig. Figure 8 is a flow diagram in solid lines, corresponding to the representation of Fig. 4 shown. Additionally, in Fig. 9 the corresponding resulting current profiles of the actuator 30 are shown, as they occur when, for example, the following defects occur: - dotted line: one air flap 32 has failed, - dashed line: some air flaps 32 have failed and - Dashed line: many air flaps 32 have failed.

[0024] By evaluating the corresponding current diagrams, in particular by comparing the current curve in the section without the springs 36 acting on it with the section acting with the springs 36 acting on it, the diagnostic system 40 can determine whether the air flap system 20 is functioning correctly or not. In other words, this allows malfunctions of the air flaps 32 to be detected.

[0025] In Fig. 5 and Fig. Figure 6 schematically illustrates a second embodiment of the air flap system 20 according to the invention, in which the air flaps 32 are arranged horizontally. For the illustration of the second embodiment, the same reference numerals have been used for identical or similar components as in the first embodiment, and their further description is omitted for reasons of brevity. Unlike the first embodiment, in which the springs 36 are arranged side by side, in the second embodiment these springs 36 are arranged one above the other.

[0026] The resulting current diagrams when measuring the current required for the operation of the actuator 30 to pivot the air flaps 32 are similar or even identical to those of the first embodiment (compare Fig. 4) and are therefore not reproduced again.

[0027] It is understood that in the present invention there is a relationship between, on the one hand, features described in connection with process steps and, on the other hand, features described in connection with corresponding devices. Thus, described process features are also to be considered device features belonging to the invention – and vice versa – even if this is not explicitly stated.

[0028] It should be noted that the features of the invention described with reference to individual embodiments or variants, such as the type and design of the individual air flaps, drive elements and springs, as well as their spatial arrangement, may also be present in other embodiments, unless otherwise specified or is precluded for technical reasons. Furthermore, not all features of such combined features of individual embodiments need necessarily be implemented in a given embodiment. Reference symbol list 20 air flap system 30 actuator 31 abutments 31a Stop bolt 31b Stop bolt 32 first group of air flaps 33 Drive rod 34 second group of air flaps 35 Drive rod 36 Leg spring / spring 37 Swivel axis 38 Drive shaft 39 mounting bolts 40 Diagnostic system

Claims

[1] Air flap system (20) for controlling the air supply to a motor vehicle, comprising - an actuator (30), - at least one group of air flaps (32, 34), each of which is arranged to pivot between an open position and a closed position, is acted upon in a first direction of rotation by means of a spring (36) and can be pivoted by the actuator (30) against the spring actuation in a second direction of rotation opposite to the first direction of rotation, and - a diagnostic system (40) designed to determine at least one parameter of the actuator (30) required for pivoting the air flaps (32, 34) in the second direction of rotation and to derive the functionality of the air flap system (20) from the at least one parameter characterized by, that each spring (36) is designed and / or arranged such that it does not exert any force in the first direction of rotation during part of the pivoting in the second direction of rotation. [2] Air flap system (20) according to claim 1, characterized by , that - the actuator (30) is an electric motor and - which is based on at least one parameter on the current value required for the operation of the actuator (30) during the pivoting of the air flaps (32, 34) in the second direction of rotation. [3] Air flap system (20) according to claim 1 or 2, characterized by , that the spring (36) is a torsion spring. [4] Air flap system (20) according to one of the preceding claims, characterized by , that each group of air flaps (32, 34) is connected to a drive rod (33, 35) which is articulated to a drive shaft (38) of the actuator (30). [5] Method for diagnosing the functionality of an air flap system (20) for controlling the air supply to a motor vehicle, wherein the air flap system (20) comprises an actuator (30) and at least one group of air flaps (32, 34), each of which is arranged to pivot between an open position and a closed position, is acted upon in a first direction of rotation by means of a spring (36) and can be pivoted by the actuator (30) against the spring actuation in a second direction of rotation opposite to the first direction of rotation, comprising the following steps: - Pivoting the air flaps (32, 34) in the second direction of rotation, wherein during a first, initial part of the pivoting movement of the air flaps in the second direction of rotation no force is applied in the first direction of rotation, but this force only comes into effect in a second, subsequent part of the pivoting movement, - Determine at least one parameter of the actuator (30) required for pivoting the air flaps (32, 34) in the second direction of rotation and - Deriving the functionality of the air flap system (20) from at least one parameter. [6] Method according to claim 5, wherein the actuator (30) is an electric motor, characterized by , that the functionality of the air flap system (20) is derived from the current value required for the operation of the actuator (30) during the pivoting of the air flaps (32, 34) in the second direction of rotation. [7] Method according to claim 5 or 6, characterized by , that the second direction of rotation is the direction of rotation for opening the air flaps (32, 34) in the direction towards the open position. [8] Method according to any one of claims 5 to 7, characterized by, that the at least one parameter of the actuator (30) required for pivoting the air flaps (32, 34) in the second direction of rotation is determined during a first part of the pivoting movement, during which there is no application in the first direction of rotation, and during a second part of the pivoting movement, during which the application in the first direction of rotation is present, and derives from the difference of the parameter values ​​determined during the two parts of the pivoting movement whether all air flaps (32, 34) are functional. [9] Motor vehicle comprising an air flap system (20) according to any one of claims 1 to 4.

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