DE102004009766A1 - Vehicle safety device with at least one actuator for moving part of outer skin of vehicle has actuator dimensions chosen so part can be accelerated only over part of distance and then covers rest of distance as result of its inertia - Google Patents

Abstract

The device (10) has at least one actuator for moving a part (12) of the outer skin of the vehicle over a predefined distance in the event of the impact of a person, especially for raising an engine hood of the vehicle over this distance. The actuator dimensions are chosen so that the part can be accelerated only over a part of the distance and then covers the rest of the distance as a result of its inertia. An independent claim is also included for a part of the outer skin of a vehicle, especially a front hood, with an inventive safety device.

Description

background the invention

The The invention relates to a vehicle safety device with at least an actuator for moving a component of the outer skin of the vehicle at a Person impact over a predefined path length, in particular for lifting a hood of a vehicle over this predefined path length.

at the constructive design and layout of modern vehicles or automobiles is getting bigger Care is taken that in the case of an accident on the outer skin the person hitting the vehicle remains as unhurt as possible. A particular danger in such an accident is the bouncing of the Person with her head on the outer skin of the accident involved This danger exists, for example, when a pedestrian, a Cyclist or a motorcyclist is caught by a vehicle and the head of the accident participant against the hood of the accident vehicle is thrown.

at modern vehicles stands in particular between the hood and an underlying drive unit, for example an internal combustion engine, not enough space for one enough size Deformation of the hood available. It therefore exists great Risk that a bouncing head has a high biomechanical load learns and "strikes" the drive unit such a danger of "beating through" an impacting one Head, so-called HIC values are determined in test series, by means of which the biomechanical load is classified can.

When possibility An improved personal protection is known, the hood or front flap of a vehicle to increase by several centimeters, as soon as an accident with a possible Person impact is detected. By lifting the hood the distance to an underlying unit is increased and further by the additional Movement of the bonnet and the associated spring forces and inertia an energy reduction over a comparatively large one Way generated. The achieved delay level for one Beating a person's head thus sinks to a biomechanical more acceptable Value and a "punch through" on one under the Bonnet arranged high stiff drive unit in the front the vehicle is prevented.

underlying task

Of the Invention is based on the object, a vehicle safety device of the type mentioned in particular with regard to the required Energy needs, while reducing costs and costs the production costs for the vehicle safety device should be reduced as possible.

Inventive solution

The Task is according to the invention with a generic vehicle safety device solved, in the actuator is dimensioned such that the component by a movement of the actor only about a leg of the predefined path length can be accelerated and following the remaining leg of the total path length due overcome its inertia can. The object of the invention is further comprising a component of the outer skin of a vehicle, in particular an engine hood of a motor vehicle, solved with such a vehicle safety device according to the invention.

According to the invention on the vehicle to be moved component of the outer skin, such as the Bonnet of a motor vehicle, only over a certain distance accelerated and then the component according to the momentum conservation of his leave your own inertia, which leads to, that the component a further leg without acceleration or with a slight deceleration due to air friction overcomes. In this way, the component to be moved over a predefined path length Overall, with comparatively little labor and energy expenditure moves and it gets over it In addition, a movement behavior of the moving component generated, which in the case of a collision is particularly advantageous.

According to the invention is in fact conditional due to the air friction of the component its speed near the End of the predefined path length comparatively small, so that the moving component, e.g. one on impacting head at a comparatively low speed approaches. This behavior of the moving component is in particular with regard to the then acting on the head biomechanical forces advantageous.

In addition, the actuator according to the invention is particularly suitable and provided for a vehicle safety device, which is reversible after moving a component of the outer skin of a vehicle and, for example, ei a user of the vehicle is to be moved back to its original position. Such a backward movement requires that the accelerating energy which it exerts on the component be reintroduced manually into the actuator. Since comparatively little acceleration energy has to be applied in the actuator according to the invention in order to accelerate the component over the limited path, only comparatively little energy needs to be introduced for the return of the actuator. The vehicle safety device according to the invention can therefore be reset relatively easily by means of a restoring device provided there. The resetting is for example possible by a raised hood completely opened by the user of the vehicle and subsequently closed again.

Of the Actuator of the vehicle safety device according to the invention can be particularly cost effective by means of a plunger, a guide and a pressure accumulator designed in such a way that the component by moving the plunger over the leg of predefined Path length accelerates becomes.

For the application it is in particular a lifting of a hood of a motor vehicle advantageous if the bonnet within a total time of 40 to 60 ms is raised while using the plunger Bonnet "only" over a period of approx. 20 to 40 ms, in particular of about 30 ms from the actuator or plunger of the Accelerating vehicle safety device according to the invention is.

Further It is advantageous if the hood to be lifted in total over a predefined path length is moved from about 40 to 80 mm and to the hood of the actuator or plunger over a Partial distance of about 20 to 40 mm, in particular of about 26 mm accelerated is.

Regarding generated by the actuator or plunger Maximum compressive force should be that for lifting a bonnet provided vehicle safety device a maximum of about 700 to 900 N, in particular about 800 N generate.

outgoing From this maximum pressure force, it is particularly advantageous if the pressure accumulator a substantially linear sloping spring characteristic having. The moving component of the outer skin of the vehicle is in such a linearly decreasing spring characteristic with increasing Way getting weaker accelerates, so the transition to the unaccelerated, free movement of the component solely due his inertia to be fluent can. A linearly sloping spring characteristic can be particularly advantageous provided by means of a coil spring as a pressure accumulator or with a gas pressure accumulator become. Alternatively or in addition to such an accumulator can also be a pyrotechnic for the actuator Energy dispenser, for example in the form of an airbag provided that by its extension the component of the vehicle skin over the Subpath of the entire predefined path length moves.

In order to a bonnet of a motor vehicle in a personal accident in their entirety should be able to move sufficiently accurately and evenly at her four actuators or plunger according to the invention with one associated with each guide and an associated one Pressure accumulator be provided. The actuators or plungers should triggered simultaneously which, for example, by a coupling of the respectively provided trigger mechanisms with the help of Bowden cables possible is.

At the hood should also advantageously at least one support element for holding the hood in the raised position and / or on Retaining hooks, especially a conventional one Bonnet lock, be provided by means of which / the predefined path length of lifting the bonnet to the desired maximum value and also can be kept. In case of triggering the vehicle safety device according to the invention is then e.g. first the Lock solved and the hood by means of the actuator over the leg of predefined entire path length accelerated. Subsequently, the hood puts the remaining leg the entire route back due to their inertia until they come off the retaining hook of the hood lock is stopped.

Approximately at the time of this "catching" the hood with Help of the hood lock becomes in case of a collision the front of the vehicle the head of the impinging person on the then hit up the hood, which ensures that the head the bonnet can deform comparatively far, without on one subjacent drive unit to push.

Summary the drawings

following becomes an embodiment of a vehicle safety device according to the invention with the attached schematic drawings closer explained. It shows:

1a a side view of an embodiment of a vehicle safety device according to the invention in the biased and locked position of an associated actuator,

1b the view according to 1a during an extension movement of the plunger,

2 the view according to 1a with a fully raised bonnet,

3a the view according to 1a with a locked lock arranged on the vehicle safety device,

3b the view according to 3a with the lock in unlocked state and

4 a graphical representation of the course of the force of the actuator during a lifting of a hood.

detailed Description of the embodiment

In the 1a to 3b is a vehicle safety device 10 illustrated, by means of in the event of an accident on impact of a person on the associated motor vehicle whose hood 12 can be raised very quickly. With the bonnet raised 12 lies between this and an underlying drive unit 14 a greater distance before, so that a penetration of particular the head of the person involved in the accident on the drive unit 14 can be prevented.

The vehicle safety device 10 has as an essential component an actuator with an actuator 16 on, on an abutment 18 supported the chassis of the motor vehicle, not shown further and in also arranged on the chassis guides 20 slidably guided. The actor 16 is opposite the abutment 18 with the help of a pressure accumulator 22 supported in the form of a coil spring, which in the prestressed state an energy store for moving the plunger 16 forms. The accumulator 22 is designed and designed such that the plunger 16 40 ms over a distance of about 40 mm is moved and thereby generates a compressive force of about 800 N maximum.

So that the plunger 16 in the in 1a shown biased position is locked and still the vehicle safety device 10 can be triggered comparatively easily, is a locking device 24 provided, in particular with a pressure element 26 in the form of a pressure lever and a tension element 28 is formed in the form of a pull lever. The pressure element 26 is at a first joint 30 supported on the chassis and on a second joint 32 at its opposite end region with the tension element 28 articulated. This tension element 28 is in turn at the opposite end of a third joint 34 on the pestle 16 hinged.

In this way, with the pressure element 26 and the tension element 28 Overall, a toggle mechanism formed in which the pressure element 26 a shorter lever element and the tension element 28 form a comparatively long lever element. The levers of the toggle mechanism can be moved near a dead center, as in 1a is shown, and in this position have a comparatively low holding moment about the first joint 30 or the third joint 34 on. The pressure element 26 and the tension element 28 can therefore in this situation with relatively little effort from a rotary latch 36 be held lightly attached to the second joint 32 attacks.

The catch 36 is by means of a pawl 38 locked by an electromagnet 40 can be moved, causing the catch 36 and thus also the locking device 24 is released.

By the pivoting catch 36 the second joint 32 releases, the pressure element rotates 26 towards the hood 12 and the likewise moving tension element 28 leaves the pestle 16 towards this bonnet 12 move. The in the accumulator 22 stored energy pushes the pestle 16 with high force against the bonnet 12 which accelerates by and from the power plant 14 is moved away.

With the movement of the hood 12 increases the distance between the drive unit 14 and the hood, which ensures that one during an accident on the hood 12 striking head of a person involved in the accident does not experience dangerously high biomechanical loads.

So that the hood 12 can be moved over a comparatively long path length X and this can still happen with a comparatively small designed and therefore comparatively inexpensive safety device are the plunger 16 , the leadership 20 and the accumulator 22 such that the bonnet 12 by the movement of the plunger 16 is accelerated only over a first section A of the predefined path length X. This leg A is the track within which the tappet 16 fully extended. Subsequently, the hood overcomes 12 a remaining section B of the entire predefined path length X according to the momentum conservation due to their inertia. This type of acceleration and subsequent movement of the hood 12 is in 2 starting from the ge dashed rest position shown the hood 12 again especially illustrated.

So that the hood 12 but not being raised beyond the predefined path length X, is an in 3b illustrated retaining hook 42 on the hood 12 provided with a fixedly attached to the chassis of the vehicle hook 44 interacts. When fully raised or raised hood 12 arrives the retaining hook 42 engaged with the hook 44 and thus prevents further lifting of the hood 12 , In such a raised position, the hood is further held by a support spring, not shown, as such only for supporting the hood 12 and essentially not as an actuator for accelerating the hood 12 acts. To open the bonnet 12 may be the engagement of the two elements 42 and 44 be solved manually.

In the 3a and 3b It also illustrates that it is right next to the actor 16 the vehicle safety device 10 a castle 46 located with the hood 12 is held in the properly closed state. The castle 46 is with a lock hook 48 provided by a rotary latch 50 is locked. Between the catch 50 and the pestle 16 is an angle lever 52 provided by a movement of the plunger 16 is pivoted and by this pivoting movement then the catch 50 releases. When turning the catch 50 becomes the lock of the lock hook 48 solved and thus the lock 46 opened, leaving the hood 12 as intended, at least the predetermined path length X can move upwards.

In the 4 the course Y of a force F over the path length X is shown, which during the extension of the plunger 16 over the section A away from the pressure accumulator 22 is produced. The force F acts on the bonnet 12 , Below is the plunger 16 limited in its upward movement and the hood 12 Due to the pulse transmitted to it, the remaining section B still moves upward until it has reached the total path length X. In this raised position is the hood 12 held by the support spring, not shown.

To reset the plunger 16 In its initial position, the work which must be applied as an integral below the force-displacement curve Y in FIG 4 to recognize and represented as hatched area. This work can for example be applied by the bonnet 12 is fully opened and then when closing the hood 12 a restoring device with a gear is set in operation, which generates a comparatively large path length, which is in particular greater than the path length X, only a comparatively small force.

Overall, according to the invention, the work to be produced (hatched area) for the return relatively small, because the inventively raised bonnet 12 is during lifting through the pressure accumulator 22 only partially accelerated, so that only the work generated thereby must be reset.

10

Vehicle safety device

12

Engine Hood

14

Drive assembly

16

tappet

18

abutment

20

guide

22

accumulator

24

locking device

26

pressure element

28

tension element

30

first joint

32

second joint

34

third joint

36

catch

38

pawl

40

electromagnet

42

Retention hook

44

hook

46

lock

48

Castle hook

50

catch

52

bell crank

X

all predefined path length

A

first leg

B

second leg

Y

Force-displacement curve of lifting

Claims (10)

Vehicle safety device ( 10 ) with at least one actuator for moving a component ( 12 ) of the outer skin of the vehicle in a collision over a predefined path length (X), in particular for lifting a hood of the vehicle over this predefined path length (X), characterized in that the actuator is dimensioned such that the component ( 12 ) can be accelerated by a movement of the actuator only over a partial distance (A) of the predefined path length (X) and subsequently the remaining part of the distance (B) of the entire predefined path length (X) can overcome due to its inertia. Vehicle safety device according to claim 1, characterized in that the actuator with a plunger ( 16 ) for moving the component ( 12 ), a guided tour ( 20 ) for mobile storage of the ram ( 16 ) and a pressure accumulator ( 22 ) for moving the plunger ( 16 ), and the plunger ( 16 ), the leadership ( 20 ) and the accumulator ( 22 ) are dimensioned such that the component ( 12 ) by moving the plunger ( 16 ) can be accelerated over the section (A) of the predefined path length (X). Vehicle safety device according to claim 1 or 2, characterized in that this for lifting a hood ( 12 ) of a motor vehicle within a total time of between about 40 and 60 ms is provided and the actuator, in particular the plunger ( 16 ), the leadership ( 20 ) as well as the accumulator ( 22 ), is / are dimensioned such that the bonnet ( 12 ) over a period of between about 20 and 40 ms, in particular of about 30 ms from the ram ( 16 ) is acceleratable. Vehicle safety device according to one of claims 1 to 3, characterized in that this for lifting a hood ( 12 ) of a motor vehicle over a predefined path length (A) of between about 40 and 80 mm is provided and the actuator, in particular the plunger ( 16 ), the leadership ( 20 ) as well as the accumulator ( 22 ), is / are dimensioned such that the bonnet ( 12 ) can be accelerated over a section (B) of between about 20 and 40 mm, in particular of about 26 mm from the actuator. Vehicle safety device according to one of claims 1 to 4, characterized in that this for lifting a hood ( 12 ) of a motor vehicle and the actuator, in particular the plunger ( 16 ), the leadership ( 20 ) as well as the accumulator ( 22 ), is / are dimensioned such that the bonnet ( 12 ) with a maximum compressive force of between about 700 and 900 N, in particular of about 800 N from the actuator can be accelerated. Vehicle safety device according to one of claims 1 to 5, characterized in that the actuator with a pressure accumulator ( 22 ) is designed, which has a substantially linear sloping spring characteristic. Vehicle safety device according to one of claims 1 to 6, characterized in that this for lifting a hood ( 12 ) of a motor vehicle and a total of four actuators, in particular four plungers ( 16 ) each with an associated guide ( 20 ) and an associated accumulator ( 22 ) are provided. Vehicle safety device according to one of claims 1 to 7, characterized in that this for lifting a hood ( 12 ) of a motor vehicle and at least one retaining hook ( 42 ), in particular a conventional bonnet lock, by means of which the predefined path length (X) of the lifting of the bonnet ( 12 ) is limited. Vehicle safety device according to one of claims 1 to 8, characterized in that this for lifting a hood ( 12 ) of a motor vehicle and at least one retaining element for supporting the hood ( 12 ) is provided in the raised position, in particular in the form of a support spring. Component of the outer skin of a vehicle, in particular bonnet ( 12 ) of a motor vehicle, with a vehicle safety device ( 10 ) according to one of claims 1 to 9.