Abstract:
The invention concerns an air outlet for a vehicle with an actuator for an air outflow, with the actuator featuring a temperature-inducible deformation effect, and means to trigger the deformation effect.

Description:
BACKGROUND 
   The present invention concerns an air diffuser for a vehicle, in particular for ventilation, heating and/or air conditioning of the passenger compartment. 
   Air diffuser are known for use in vehicles of various kinds. They allow a entry of fresh air, heated and/or colled air into a vehicle interior. Usually, anticipated air diffusers have an air outlet element with passage ways and which is rotatable around one or several axes. By orienting the air outlet element the direction of the air stream can be selected. 
   From patent DE 19721831A1 an air diffuser for the interior of a vehicle is known where the air outlet element features a partial area for a diffuse air exit and a partial area for an unrestricted air exit over a larger area, and where the manner of the air exit can be selected by turning the air exit element. 
   From patent DE 4338099C2 is also known an instrument panel with a large-surface perforated air exit surface covering an airduct on one side, for diffuse air distribution. 
   Here the large-surface perforated air exit area forms the top side of the instrument panel facing the windshield. The air exit area is connected to an air distributor box which has a perforated ventilation damper for controling the airstream. Additional air supply devices for the vehicle interior which allow diffuse ventilation, are for instance known from patents DE 3908541C2, DE 1530615 and DE 1909519. 
   Anticipated air outlets are generally adjusted manually. There are however air outlets in the luxury class that are driven by an actuator. 
   From patent DE 3717676 A1 a vehicle air conditioning unit is known which has a bimetallic tab which effects a commutation at a channel branching, depending on the airstream temperature, the airstream intensity or according to a time function. 
   A disadvantage of anticipated air outlets for producing a diffuse flow field is the flow field is not adequately diffuse, i.e., that it is still distinguishable as a directed flow field and/or that the constructive expenditure for obtaining the diffuse flow field is relatively high. 
   Furthermore it is also known from the state of the art, to provide a vehicle seat with ventilation. In the so-called “climate seat” of the BMW 7 vehicles multistage fans are imbedded in the upholstery of seat and back which circulate air from the vehicle interior through the seat upholstery. By means of balance control heat distribution between the seat are and the seatback can be adjusted individually. Here again it is disadvantageous that the constructive expenditure for making such a ventilated seat is relatively high. 
   The invention is therefore based on the objective to create an improved air outlet for a vehicle, as well an an improved instrument panel, a headliner and interior covering with a ventilating function, as well as a vehicle seat with integrated ventilation. 
   The objective the invention is based on is being solved with the characteristics of the individual patent claims. According to invention an actuator for the air outflow is used which features a temperature-inducible deformation effect. Furthermore, means are provided for inciting the deformation effect, in order to achieve a desired setting of the airstream. 
   According to a preferred design of the invention the actuator is in the form of a flexible strip. When for instance a current is applied to the actuator the actuator gets hot and bends so that an air exit opening is unblocked more or less. Alternatively the deformation effect of the actuator is induced by heating the actuator with a controllable radiation source. 
   According to another preferred design of the invention the actuator is formed for the arching of an interior covering. For this purpose, several adjacent actuators are for inprovided which each featuring a deformation effect in the opposite direction. Through temperature induction of the de formation effect this results in the formation of air exit openings of varying size. 
   According to another preferred design of the invention the actuators are arranged on a meander-shaped support. The deformation effect causes a deformation of the support which consequently unblocks a air exit opening. 
   According to another preferred design of the invention the actuator is supported solidly one one side and detachably on an opposite side. The detachable support may for instance be realized with electromagnetic means. 
   According to another preferred design of the invention each actuator can be controlled separately, or groupd of actuators are formed with the individual groups being each separately controllable. 
   According to a preferred design of the invention a large-surface air exit area is realized in the area of the instrument panel, the headliner or another interior covering component. For this purpose several actuators are distributed over the air exit area. 
   According to another preferred design of the invention one or several actuators are provided in a vehicle seat for supplying the airstream through the seat surface. 
   For the realization of the temperature-inducible deformation effect of the actuator several suitable technologies may be applied. An actuator may for instance be realized by sandwiching materials of different thermal expansion coefficients; when different metallic materials are used, such an arrangement is called a bimetall strip. 
   According to a preferred design of the invention the temperature-inducible deformation effect is achieved by using materials with a shape-memory effect. Appropriate alloys are also called Shape-Memory-Alloys (SMA). Examples for this are the NiPi- and NiTiPb alloys. Additional shape-memory alloys are known from “Alloys with Shape-Memory”, Dieter Stöckel, Erhard Hornbogen, Expert-Verlag, 1988, ISBN 3-8169-0323-1. Alternatively or additionally conductive synthetic materials as they are known in the field of polyelectronics may be used. 
   The deformation effect is a reversible effect. For this one may use a one-way effect with an additional mechanic readjusting device. This reversible effect is based on the fact that so-called memory-alloys are considerably less solid in the martensitic state than in the high-temperature phase. It is therefore by heating that the deformation of the actuator into the high-temperature form is achieved, for instance through the supply of an electrical current. After the current is switched off the actuator does not automatically resume its original shape, but it is returned ot its original shape by a force produced by appropriate mechanical means. 
   Alternatively, a material is used that features a two-way effect. With the two-way effect the material “remembers” both the high-temperature and a low-temperature form. As a special case of the two-way effect one may also use materials featuring an all-round effect. 
   Use of materials with shape-memory effect for automotive technology is as such known from “Alloys wwith shape-memory”, chapter 3.8.2, page 92 to 94, and notably for fog lights with protective lamella against stones with a nickel-titanium spring as memory element and also for temperature-dependent actuating functions for engines, transmissions and chassis, as for instance for fan clutches of engines, throttling devices of injection pumps as well as for vehicle transmissions with enhanced shifting behavior. From patent CA 2346260A1 one is also familiar with the use of shape-memory alloys for the setting/adjusting of a rearview mirror. 
   SUMMARY OF THE INVENTION 
   The present invention allows the advantageous use of materials with shape-memory effects for realizing an air outlet for a vehicle. Through the use of materials with shape-memory it is possible to create a large-surface diffused flow field which vehicle occupants find to be especially pleasant. 
   According to a preferred version of the invention an appropriately large-surfaced air outlet is integrated into the instrument panel. Alternatively or additionally the air outlet may also be integrated into the headliner or another interior covering element. And it is also possible to integrate an air outlet according to invention into a vehicle seat. 
   In the following some preferred versions of the invention are explained in detail with reference being made to the drawing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  a first version of an air outlet in its closed state. 
       FIG. 2  the air outlet of  FIG. 1  in the opened state, 
       FIG. 3  a second version of an air outlet in its closed state, 
       FIG. 4  the air outlet per  FIG. 3  after driving it to direct the airstream into a first direction, 
       FIG. 5  the air outlet per  FIG. 3  after driving it to direct the airstream into a second direction, 
       FIG. 6  a cross section of an air outlet in closed condition that is integrated into an interior covering element, 
       FIG. 7  the interior covering element of  FIG. 6  in its opened condition, 
       FIG. 8  an interior covering element with a lamellar, parallel arrangement of actuators in the closed condition, 
       FIG. 9  the interior covering element of  FIG. 8  in the opened condition, 
       FIG. 10  an interior covering element with a meander-shaped support in the closed condition, 
       FIG. 11  the interior covering element of  FIG. 10  in the opened condition, 
       FIG. 12  a perspective view of an instrument panel with integrated large-surfaced outlet and 
       FIG. 13  the instrument panel of  FIG. 12  with the outlet in the opened condition. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
     FIG. 1  shows an interior covering element  100  of a vehicle. Integrated into the interior covering element  100  is an outlet which features several actuators  102 . Each actuator  102  has a material layer  104  of a material with a temperature-inducible deformation effect. 
   The material is for instance a shape-memory alloy, i.e., a so-called Shape-Memory-Alloy (SMA). The material layer  104  is in the form of strips and fastened at its one end on the support  106 . 
   On the surface of the material layer  104  is an additional layer  108 . The layer  108  may be a decorative layer or it may be another functional layer. In the latter case the layer  108  may be of the same material as the layer  104 , with the material in layer  108  being in a different phase, i.e. for instance in the material layer  104  in the austenitic phase and in the material layer  108  in the martensitic phase or vice versa. 
     FIG. 1  shows the condition of the interior covering element  100  in its closed state. In this state the actuators  102  are in their low temperature shape. 
   By applying a voltage or other induction of current into the material layer  104  the temperature is increased by several degrees Kelvin. Alternatively one may also use a radiation source below the actuators  102  to increase the temperature. The temperature change causes the actuators  102  to “remember” their high temperature shape and to transition to it, as shown in  FIG. 2 . Through the transition to the high temperature shape the actuators  102  unblock air exit openings  110  through which air  112  can stream from a fan into the passenger compartment. 
   When a Shape-Memory-alloys with two-way effect is used for the material layer  104 , the actuator  102  resumes, after the current or the radiation source is shut off and due to the cooling caused thereby, its low-temperature shape shown in  FIG. 1 . By selecting the current or radiation intensity and thereby the associated temperature it is possible to regulate the bending of the actuators  102  and thereby the size of the air exit opening  110 . 
   When using a Shape-Memory-Alloy with one-way effect the layer  108  may serve for the application of a mechanical restoring force to the material layer  104 . After cooling of the material layer  104  this layer retransitions to the martensitic phase and is restored to its original position by the layer  108  above it, which has been elastically deformed by the high-temperature shape of the material layer  104 . 
   Here is is particularly advantageous that the interior covering element  100  with integrated air outlet can be made from a small number of individual components and that the air outlet can be controlled by an electrical current for instance without requiring an otherwise usual servomotor. 
   These advantages come together with a lower weight. An additional particular advantage is that a large-surface air stream from the interior covering element  100  can be realized with little constructive expenditure. 
     FIG. 3  shows an interior covering element  300 . Similar to the interior covering element  100  of  FIGS. 1 and 2  the interior covering element  300  of  FIG. 3  does also have actuators  302 . Furthermore the interior covering element  300  has actuators  303  which are built in mirror image to the actuators  302 . 
     FIG. 3  shows the interior covering element  300  with closed actuators  302  and  303 , when the actuators  302 ,  303  are in their low temperature form. If the temperature of only the actuators  302  is being increased, e.g. by applying a voltage or inducing a current or through external radiation, these actuators  302  assume their high temperature shape shown in  FIG. 4 . Thereby air exit openings  310  are unblocked, in order to direct the airstream of the fan for instance for de-icing of the windshield of the vehicle. The actuators  303  remain in their low temperature shape. 
   If, on the other hand, voltage for instance is applied only to actuators  303  so their temperature increases, the actuators  303  assume their high temperature shape as shown in  FIG. 5 . This unblocks air exit openings  311  in order to direct the fan air for instance into the direction of the vehicle occupants. 
   With the shape of actuators  102  of  FIG. 1  or with the shape of actuators  302 ,  303  of  FIG. 3  respectively, it may be the low temperature shape or also the high temperature shape. In this case an increased temperature must be present to achieve the clsoed condition of the interior covering element  100  or of the interior covering element  300  respectively. To realize air exit openings  110  or  310  or  311  respectively the voltage applied to each must be reduced appropriately or shut off, to let the desired actuators transition to the low temperature shape. 
     FIG. 6  shows an interior covering element  600  with several actuators  602  which are held in place by supports  604 . The actuators  602  consists of a shape-memory alloy with a high temperature and a low temperature shape. The shape of the actuators  602  shown in  FIG. 6  for instance is the low temperature shape. 
   The low temperature shape of actuators  602  is essentially level. The actuators  602  carry a decorative layer  606 . This may be for instance a casting skin made of polyurethane or PVC, a so-called slush skin or a spray skin. Alternatively or additionally the decorative layer  606  may also feature a fabric layer. The decorative material visible from the outside of the decorative layer  606  may for instance be applied to a layer consisting of polypropylene foam. 
   By applying a voltage to the actuators  602  a current is produced which heats the actuator  602  so that they assume their high temperature shape, as shown in  FIG. 7 . In their high temperature shape these actuators  602  are curved upwards. This deformation of actuators  602  changes the shape of the flexible decorative layer  606 . This deformation unblocks air exit openings  610  through which air can stream into the passenger compartment in a diffuse manner. 
     FIG. 8  show a perspective view of the interior covering element  600 . The decorative layer  606  has incisions along the lines  614  resulting in several strips  616  and  618 . As shown in  FIGS. 6 and 7  the area of strip  616  is built up. In the area of strip  618  the actuators  612  located there undergo during increased temperature a deformation that is opposite in direction to the deformation of actuators  602 , i.e., the actuators  612  are curved downward in their high temperature shape. 
   The interior covering element  600  may feature a multitude of lamella-like strips  616  and  618  arranged side by side with the strips  616  and  618  succeeding each other alternatingly. If no control signal is applied, all actuators  602  and  612  are in their low temperature shape thereby creating an essentially closed surface of the interior covering element  600 . 
   Through induction of the deformation effect the actuators  602  transition to their upward-bent high temperature shape while the actuators  612  transition to their downward-bent high temperature shape. This causes the creation, in the area of strips  616  and  618  convexity in opposite directions of the surface of the interior covering element  600 . Where adjacent strips  616  and  618  border on each other, the opposing convexities serve to unblock the air exit openings  610  (compare to  FIG. 9 ). 
     FIG. 10  shows an interior covering element  700  with a meander-shaped support  702  for actuators  704  made of a shape-memory alloy. Actuators  704  are each arranged on parallel opposing sections of the meander-shaped support  702 . The intermediate sections  708  of the meander-shaped support  702  do not bear any actuators  704 . The sections  706  of the meander-shaped support  702  are solidly connected to the interior covering element  700 . Along the remaining sections of the meander-shaped support  702  there are incisions into the surface of the interior covering element  700 . 
   Through induction of the deformation effect the actuators  704  transition from their low temperature shape into their upward-bent high temperature shape, as shown in  FIG. 11 . This causes the actuators  704  and the sections  708  of the interior covering element  700  opposite the sections  706  to unblock air exit openings on the surface of the interior covering element  700 . 
     FIG. 12  shows an instrument panel  800  on the upper part of which strips  616 ,  618  are arranged in alternating sequence. On principle these are constructed as explained above with reference to  FIGS. 6 to 9 . Preferably the entire surface of the instrument panel  800  is essentially subdivided into strips  616  and  618 . 
     FIG. 12  shows the strips  616 ,  618  in closed condition so that an essentially smooth surface is created on the upper side of the instrument panel  800 . By appropriate triggering of the actuators arranged on the strips  616 ,  618  the upper side of the instrument panel assumes an undulatory structure (compare  FIG. 9 ). This creates a multitude of air exit openings  610  on the upper side of the instrument panel  800  as shown in  FIG. 13 . This results in a large-surface diffuse airstream field which the occupants find to be very pleasant. 
   Alternatively the upper side of the instrument panel  800  may be equipped with meander-shaped supports (compare meander-shaped supports  702  of  FIGS. 10 and 11 ), in order to realize air exit openings by exploiting the shape-memory effect. 
   Instead of on the upper side of the instrument panel  800  it is possible in this manner to create large-surface outlets also in other vehicle parts for the creation of a diffused ventilation. For instance the headliner as well as side covering elements, seat covering elements and covering elements of the center console may be used for this purpose. 
   LIST OF REFERENCE MARKS 
   
       
       Interior covering element  100   
       Actuator  102   
       Material layer  104   
       Support  106   
       Layer  108   
       air exit opening  110   
       air  112   
       Interior covering element  300   
       Actuator  302   
       Actuators  303   
       air exit opening  310   
       air exit opening  311   
       Interior covering element  600   
       Actuator  602   
       Support  604   
       Decorative layer  606   
       Air exit opening  610   
       Stellelement  612   
       Linie  614   
       Streifen  616   
       Streifen  618   
       Innenverkleidungsteil  700   
       meander-shaped support  702   
       Stellelemente  704   
       Abschnitt  706   
       Instrumententafel  800