Title: Adjustment device for adjusting shutoff elements of an air inlet of a motor compartment of a motor vehicle, provided with an emergency adjustment device for opening the shutoff elements

The invention relates to an adjustment device for adjusting shutoff elements of an air inlet of a motor compartment of a motor vehicle, provided with an emergency adjustment device for opening the shutoff elements.

Such adjustment devices are known, for example, from the Dutch patent publication having publication number NL2010428, in which it is described how the air inlet of a motor compartment can be wholly or partly closed. A first intended advantage of such an adjustment device concerns regulation of the engine temperature. This can be advantageous for the fuel consumption and hence for reducing C02 emission. A risk involved, however, is that if the adjustment device does not function properly, for example due to a current interruption, the shutoff elements for the air inlet cannot be adjusted anymore and, for example, remain closed, as a result of which the motor compartment will experience an unwanted temperature rise. This can lead to increased fuel consumption and increased C02 emission, and possibly even to damage to the engine of the vehicle. This is why adjustment devices of shutoff elements for an air inlet are sometimes provided with an emergency adjustment device which automatically opens the shutoff elements in case of a current interruption.

The air inlet for the motor compartment is usually located at the front of the motor vehicle. A second intended advantage of the adjustment device concerns, if the temperature of the motor compartment allows this, the closing of the inlet and thereby lowering the air resistance of the vehicle, which will lead to lowered fuel consumption and a reduced CO2 emission. This reduced air resistance of the vehicle, however, has a drawback, especially if the vehicle is to be braked strongly, for example to avoid a crash with another user of the public highway.

It is an object to at least partly counteract a disadvantage as mentioned.

To this end, the invention provides an adjustment device for adjusting shutoff elements of an air inlet of a motor compartment of a motor vehicle, provided with an emergency adjustment device for opening the shutoff elements, wherein the emergency adjustment device is configured to be activated by a pre-crash circuit.

The maximum braking force on a vehicle is caused by an interplay of factors, such as the braking force on the brake discs, the rolling and frictional resistance between wheels and road surface, and the air resistance of the vehicle. It holds in general that the higher the air resistance of an unenergized vehicle, the faster such vehicle comes to a halt, and hence the shorter the stopping distance. By including an activation circuit for the emergency adjustment device in the so-called pre-crash circuit such as frequently found on vehicles nowadays, in case of an imminent collision or emergency stop the shutoff elements can be opened to augment the air resistance of the vehicle and reduce the stopping distance. Such a pre-crash circuit can predict from multiple sources the odds of a crash event and then take actions on that. Such sources include, for example, information from camera images, radar or lidar sensors such as used in adaptive speed control, and data from the vehicle itself, such as, for example, the driving speed. Actions that such a circuit can take include, for example, pre- positioning the brake blocks of the braking device, so that these can respond faster to the driver, or even wholly independently actuating the braking device. It is also conceivable, for example, that vehicle seat belts are tightened, or that airbags are preventively activated. The pre-crash circuit comprises a control unit which receives input from one or more sensors. Such sensors can be, for example, a camera, a radar or a lidar sensor, an accelerometer, etc. The control unit is configured to determine on the basis of the input from the sensors whether a crash is imminent, i.e., whether a pre-crash situation is involved. If a pre-crash situation has been detected, the control unit can send control signals to components of the vehicle to anticipate the expected crash situation. According to the invention, the control unit of the pre-crash circuit can send a control signal to the emergency adjustment device of the adjustment device, for adjustment of shutoff elements of an air inlet of a motor compartment of the vehicle. Such a control signal can for instance comprise a signal for adjustment of the shutoff elements to the "open" position, or a signal for interruption of the current supply to the adjustment device, etc. The pre-crash circuit can thus send a control signal to the adjustment device and/or the emergency adjustment device to adjust the shutoff elements to the open position, in case a pre-crash situation has been detected by the pre-crash circuit. In particular when the control signal is intended to trigger the emergency adjustment device, the emergency adjustment device will activate though no calamity has been detected but a pre-crash situation has been determined by the pre-crash circuit.

In a follow-on aspect of the invention, the pre-crash circuit interrupts the current supply to the adjustment device of the shutoff elements as a result of which the emergency adjustment device is energized and the shutoff elements are opened, which will bring about the desired increased air resistance.

Often, adjustment devices for shutoff elements are included in a combined power and data communication system, such as, for example, a LIN bus system. The adjustment device is then provided with, for example, a triple pole connection with the vehicle control system. Two poles take care of the power supply, while the third pole is used for transmission of signals. Included in the adjustment device is a translation unit, which can convert the LIN bus signal into a steering of the shutoff elements to the desired position. The translation unit consists of, for example, a microprocessor and a number of electronic components, such as, for example, a relay or a transistor. In a second follow-on aspect of the invention, the pre-crash circuit actuates the emergency device by means of the combined power and data communication system. This has as an additional advantage that the power supply to the adjustment device is not interrupted. When the vehicle has almost come to a stop, open shutoff elements can be disadvantageous if it should come to a crash after all, especially when it comes to a crash with pedestrians or animals. For it is a well-known fact that in such a crash, the air inlet of a vehicle can be an important source of injuries. It would be better then if the shutoff elements were closed at the time of the crash.

Accordingly, it is a third follow-on aspect of the invention that if the speed of the vehicle has been reduced sufficiently, or has been reduced to the point where an increased air resistance will have little influence on the final speed immediately prior to the crash, the adjustment device brings the shutoff elements to the closed position again.

According to an aspect of the invention, the pre-crash circuit is included in the housing of the adjustment device, at any rate at least a part of the control unit may be included in the housing. For example, a part of the control unit that receives input signals from a camera sensor in the proximity of the adjustment device may be included in the housing of the adjustment device. Alternatively and/or additionally, the adjustment device may be provided with a LIN bus connector, which receives signals from the motor vehicle LIN bus circuit. The LIN bus connector may be additionally configured for also receiving a control signal from the pre-crash circuit to trigger the adjustment device and/or the emergency adjustment device to adjust the shutoff elements to the open position, in case of a detected pre- crash situation. Further advantageous embodiments are set forth in the subclaims.

The invention also relates to a motor vehicle provided with an adjustment device, and to a method for adjusting shutoff elements of an air inlet of a motor compartment of a motor vehicle, provided with an

emergency adjustment device for opening the shutoff elements, wherein the emergency adjustment device is activated by a pre-crash circuit.

Brief description of the figures

The invention wiH be elucidated on the basis of an exemplary embodiment which is represented in drawings. In the drawings:

Fig. 1 shows an air inlet with the shutoff elements in closed position

Fig. 2 shows an air inlet with the shutoff elements in opened position

Fig. 3 shows a possible implementation of an adjustment device with emergency adjustment device

Fig. 4 shows an example of a connection diagram with the pre-crash circuit.

It is noted that the figures are merely schematic representations of preferred embodiments of the invention which is described by way of non- limiting exemplary embodiment. In the figures, the same or corresponding parts are designated by the same or corresponding reference numerals.

Detailed description of exemplary embodiments

Figure 1 shows in front view an air inlet (1) of a motor vehicle including shutoff elements (2). The shutoff elements are in the closed position. Not visible in the drawing are distance sensors (3) included in or being part of, for example, the bumper. These sensors preferably consist of a transceiver of radar waves, but can also consist of, or include, a camera circuit or transceiver of lidar waves. The sensors are mainly directed forward in the driving direction, and hence have a view of what is

happening forwardly of the vehicle.

Figure 2 shows in front view an air inlet (1) again including shutoff elements (2). The shutoff elements are now in the opened position.

Figure 3 shows an embodiment of an adjustment device (4) with emergency adjustment device (4'). The adjustment device is included in a housing (5) in which an electric motor (6), by means of a reduction device (7) consisting of multiple gears (7'), drives at least one output shaft (8) for adjusting the shutoff elements. In this embodiment, the reduction device includes a three-shaft planetary gear system (7"), a first input shaft which may or may not be directly driven by the electric motor, a first output shaft coinciding with the output shaft (8), and a second output shaft which is under spring action from, for example, a curved helical spring (9). At standstill, the first and second output shafts are rotation-coupled. In the normal use situation, the second output shaft is blocked from rotation by a locking (10') energized by an electric coil (10). Locking, coil and helical spring together form the emergency adjustment device. For an extensive description, see e.g. the Dutch patent publication NL2007162. Not visible are a number of electronic components for, for example, translating the incoming LIN bus signals. Upon an appropriate LIN bus signal, or upon the power supply failing altogether, the electric coil will no longer energize the locking, and thereby release the spring force stored in the helical spring, so that the shutoff elements due to the coupled first and second output shafts come to be in the open position. If the emergency adjustment device was prompted by a LIN bus signal and the power supply is still intact, the adjustment device could bring the shutoff elements to the closed position again, to reduce or avoid injuries in a crash. Figure 4 shows a schematic representation of the adjustment device with emergency adjustment device included in a pre-crash circuit (11). If the distance sensors (3) deliver signals which may point to a potential crash ahead, for instance by generating an estimated approach speed with the aid of successive measurements of the distance between the vehicle and an object, the control unit included in the pre-crash circuit, that is, a calculation and control unit (12), will determine to what extent there's a risk of a crash event. The pre-crash circuit then relies on the data supplied by the sensors as well as on other relevant factors (13', 13", ...), such as the driving speed of the vehicle, the theoretical stopping distance, etc. If a crash, with conditions unchanged, seems unavoidable, the pre-crash circuit will independently take actions (14', 14", ...) for additional protection of the occupants, such as tightening the seat belts, moving the head restraint forward, activating airbags, etc. In addition, to avoid the crash, the pre-crash circuit will brake preventively, and to augment the air resistance of the vehicle it will activate the emergency adjustment device of the adjustment device for the shutoff elements, for example by means of an appropriate LIN bus activation signal (14"'), or by simply cutting off the current supply to the adjustment device. Should the adjustment device be provided with a LIN bus connection and, after activation of the emergency adjustment device, the power supply be intact, the pre-crash circuit, if the vehicle has been slowed down sufficiently, can have the shutoff elements closed again, to reduce bystander injuries.

The invention is not limited to the exemplary embodiments represented here. Variants are possible. For example, the pre-crash circuit may be included in the adjustment instrument, be provided with its own sensors and/or cameras for determining the approach speed relative to objects and the like, or a pre-crash circuit included in the adjustment instrument may autonomously communicate with sensors and cameras provided elsewhere in or on the vehicle. Also, the shutoff elements may be shaped or provided with various features in such a way that they cause additional turbulence in open position and thereby reduce the braking distance still further. Such variants are understood to fall within the scope of the invention as set forth in the appended claims.

REFERENCE NUMERALS

1. Air inlet

2. Shutoff element

3. Distance sensors

4. Adjustment device

4'. Emergency adjustment device

5. Housing

6. Electric motor

7. Reduction device

7. Gear

7". Planetary gear system

8. Output shaft

9. Helical spring

10. Electric coil

10'. Locking

11. Pre-Crash circuit

12. Calculation and control unit

13', 13". Relevant factors

14', 14". Actions

14'". LIN bus activation signal