Abstract:
A vehicle includes a fascia, a bumper beam, and a sensor including a pressure chamber disposed between and along the fascia and bumper beam. The vehicle further includes a plurality of pusher blocks disposed between and along the fascia and bumper beam. The pusher blocks impinge upon the pressure chamber during fascia impact. Contact areas defined by the pusher blocks decrease toward a center of the pressure chamber and increase toward ends of the pressure chamber.

Description:
TECHNICAL FIELD 
     The present application relates to vehicle fasciae. 
     BACKGROUND 
     During an impact with vehicle fascia, the perpendicular component of the impact force is translated into the fascia. This perpendicular component is greater when the impact occurs at a center of the fascia as compared with an impact near a side of the fascia. For accurate classification and deployment of protection measures, at least one pressure tube and a plurality of sensors may be disposed between the fascia and corresponding bumper to assist control logic in making decisions. 
     SUMMARY 
     A vehicle includes a bumper structure including a fascia, a beam, a sensor disposed between the fascia and beam and defining a pressure cavity along the fascia, and a plurality of pushers disposed between the fascia and sensor. The pushers are configured such that, for a given vehicle speed, an impact with the bumper structure near a center of the fascia causes a pressure increase within the pressure cavity approximately equal to an impact with the bumper structure near an end of the fascia. 
     A vehicle includes a fascia, a bumper beam, a sensor including a pressure chamber disposed between and along the fascia and bumper beam, and a plurality of pushers disposed between and along the fascia and bumper beam. The pushers are configured to impinge upon the pressure chamber during fascia impact. Contact areas defined by the pushers decrease toward a center of the pressure chamber and increase toward ends of the pressure chamber. 
     A vehicle includes a fascia having a curvature, a pressure sensor coupled with a chamber disposed behind the fascia, and a plurality of pushers, having different contact areas, attached along the curvature. The contact areas complement the curvature such that, for a given vehicle speed, an impact near a center of the fascia causes a pressure increase within the chamber approximately equal to an impact near an end of the fascia. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vehicle; 
         FIG. 2  is a plan view of vehicle fascia formed with pushers disposed between the fascia and corresponding bumper beam; 
         FIG. 3  is a plan view of the pushers during a center vehicle impact; and 
         FIGS. 4 and 5  are plan views of the pushers during side vehicle impacts. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
     Referring to  FIG. 1 , a vehicle  10  having a fascia  12  with a plurality of pusher blocks  14  is shown. The blocks  14  may be disposed behind the fascia  12 . A pressure tube  18  may be disposed between a bumper  16  and the blocks  14 . The pressure tube  18  includes a pressure sensor  20  to monitor a change in pressure within the tube  18  during an impact event. The pressure sensor  20  may be located at the center of the pressure tube  18 . 
     When a vehicle  10  is impacted, the fascia  12  impacts the pressure tube  18  before impacting the bumper  16 . This causes a change in volume of the pressure tube  18 . The change in volume within the pressure tube  18  indicates, to the pressure sensor  20 , an impact. The pressure sensor  20 , after an impact, sends a pressure signal to a controller  32  indicating the impact characteristics. These include the change in volume of the pressure tube  18 , a magnitude of the impact force, and a length of time of the impact. The controller  32  uses the impact characteristics to determine deployment of protection measures. If the impact characteristics are above a threshold condition, then the controller  32  deploys the protection measures. 
     The fascia  12  has a curvature  13  such that a perpendicular component of the impact force has a different effective magnitude depending on the impact location. The effective magnitude of the impact force decreases as the impact occurs further from a center  22  of the vehicle  10 . For example, an impact with a center  22  of the vehicle  10  will have a greater effective magnitude than the same impact on a side  24  of the vehicle  10 . The differing effective magnitudes of the same impact results in different volume changes in the pressure tube  18  for the same impact. This results in two different pressure signals from the pressure sensor  20  for the same impact. 
     A different change in pressure within the tube  18  for the same impact may result in the controller  32  not deploying a protection measure for a side impact and deploying a protection measure for a center impact. In order to compensate for the differences between similar impacts at different locations additional components may be needed. For example, at least one pressure tube  18  having a plurality of pressure sensors  20  may further help compensate for the difference. This requires the use of various systems to determine appropriate protection deployment threshold conditions for the same impact event. 
     Examples disclosed herein may attempt to equalize the pressure change within the tube  18  regardless of the impact location for similar impact events. Pressure may be determined by dividing the impact force over the area impacting the pressure tube  18 . Knowing the curvature  13  of the front fascia  12  allows for a determination of the impact force at various locations on the fascia  12 . Therefore, certain examples adapt a geometric ratio of the block area to account for the differing impact forces of the differing fascia locations. This equalizes the volume change in the tube  18 , regardless of the impact location, by changing the area of the block  14  based on the magnitude of the impact force at that location. 
     Adapting the geometric ratio of the blocks  14  based on the curvature  13  of the fascia  12  allows a single pressure sensor  20  to be disposed on a single pressure tube  18 . This allows the pressure sensor  20  to send a more accurate signal to the controller  32 . A more accurate identification of the volume change, and as such the pressure change, further allows the controller  32  to more quickly classify the impact and deploy a protection measure. The controller  32  may deploy a protection measure if the magnitude of the impact is above a threshold. 
     Referring to  FIG. 2 , a view of the fascia  12  having pusher blocks  14  is shown. The blocks  14  are shown attached to the fascia  12 . The blocks  14  may also be disposed on the bumper  16 . Attached to the fascia  12 , the blocks  14  are disposed in a way such that, upon an impact, they indent the pressure tube  18 . The geometric ratio of the blocks  14  impact the size of the indent on the pressure tube  18 . The size of the indent on the pressure tube  18  impacts the fluid flow within the pressure tube  18 . Therefore, adaptation of geometric ratios of the blocks  14  based on the impact location helps to control the fluid flow within the tube  18 . This allows for equalization of the pressure within the tube  18  at the pressure sensor  20  despite differing impact forces at various locations on the fascia  12 . The block geometry depends on the location of the block  14  on the fascia  12 . 
     As stated above, the fascia  12  has a known curvature  13 . This allows for determination of the effective impact force component at each location of the fascia  12 . This also allows for optimization of the block geometry. For example, a block  14  at a high impact area  26 , such as the center  22  of the vehicle  10 , may have a smaller contact area  28  with the pressure tube  18 . Likewise, a block  14  at a low impact area  30 , such as on the side  24  of the vehicle  10 , will have a larger contact area  28  with the pressure tube  18 . Therefore, a high impact force near a center of the fascia  12  may cause a smaller change in volume within the tube  18 . And, a low impact force near an end of the fascia  12  may cause a higher change in volume within the tube  18 . 
     The pressure within the tube  18  is a function of the difference between the volume of the tube  18  before an impact and the volume of the tube  18  after the impact. Further, the pressure within the tube  18  depends on the force of the impact over the contact area  28  of the blocks  14  on the tube  18 . Adjusting the contact area  28  of the blocks  14  allows for the difference between the volume of the tube  18  before an impact and the volume of the tube  18  after the impact to be dependent on the force of the impact. 
     Modifying the contact area  28  of the blocks  14  to equalize the force of an impact, regardless of the location of the impact on the fascia  12 , allows for a single pressure tube  18  and a single pressure sensor  20  to be used. The pressure sensor  20  will send a single pressure signal identifying the impact characteristics to a controller  32 . The controller  32  compares the pressure signal to a threshold condition and classifies the impact. This allows the controller  32 , using protection control logic, to further discriminate between types of impacts. Further discriminating between impact types allows the controller  32  to deploy a protection measure using a single pressure sensor  20 , if the pressure signal from the pressure sensor  20  is above the threshold condition. 
     Referring to  FIG. 3 , a perspective view of the fascia  12  is shown being impacted at the center  22 . Impacting the center  22  of the vehicle  10  displaces the fascia  12  causing the blocks  14  to indent the pressure tube  18  before impacting the bumper  16 . Due to the higher impact force component, as described above, the blocks  14  disposed at the center  22  of the vehicle  10  press into the pressure tube  18  deeper than an impact at a side  24  of vehicle  10 . The depth of the indent caused by the blocks  14  into the pressure tube  18  may be based on the geometry of the contact area  28  of the blocks  14 . 
     The contact area  28  of the blocks  14  increases as the blocks  14  move away from the center  22  of the vehicle  10 . This ensures that the magnitude of the impact force on the pressure tube  18  is equal despite the location of the impact on the fascia  12 . For example, high impact force areas  26  have a smaller contact area  28  resulting in a longer depth indentation on the tube  18 . Likewise, low force areas  30  have a larger contact area  28  resulting in a shorter depth indentation on the tube  18 . The depth of the indentation caused by the blocks  14  on the pressure tube  18  decreases as the blocks  14  move away from the center  22  of the vehicle  10 . 
     By equalizing the pressure signal characteristics throughout the fascia  12 , the pressure signal allows the controller  32  to further classify the impact event. This may allow the controller  32  to respond quicker after an impact has taken place. The differing contact area  28  of the blocks  14 , therefore, may reduce the response time of controller  32 . 
     The differing contact area  28  of the blocks  14  allows a similar pressure signal to be sent to the controller  32 . This is due to displacement of the fascia  12  at any impact location that forces the blocks  14  into the pressure tube  18 . Despite the location of the impact on the vehicle  10 , the pressure signal from the pressure sensor  20  will have the same characteristics, such as slope and magnitude, and will peak at the same time. This further allows for equalization of the signal characteristics and reduces the need for an additional pressure tube as well as the need for an additional pressure sensor. 
     Referring to  FIG. 4 , a perspective view of an impact with a side  24  of the vehicle  10  is shown. As described above, the contact area  28  of the blocks  14  is related to the depth of the indentation of the pressure tube  18 . The penetration of the contact area  28  into the pressure tube  18  determines the change in volume of the pressure tube  18 . In order to sufficiently optimize the threshold condition, the strength of the material used to form the blocks  14  drives the shape of the contact area  28  of the block  14 . Therefore, the strength of the material used to form the blocks  14  drives the change in volume within the pressure tube  18 . 
     The strength of the material of the blocks  14  drives the geometry of the contact area  28 . For example, when using a commonly soft pressure tube  18  having a minimum stiffness, different materials may impact the pressure tube  18  in different ways. A relatively rigid material, such as a rigid plastic or metallic material, may create deeper indentations in the pressure tube  18 . This would result in a higher change in volume within the pressure tube  18  giving the pressure sensor  20  a higher magnitude pressure signal. Likewise, a relatively pliable material, such as rubber or any other nonmetallic material may indent the pressure tube  18  less than the rigid material. This would result in a lower change in volume within the pressure tube  18  giving the pressure sensor  20  a lower magnitude pressure signal. 
     The strength of the material, and as such the shape of the contact area  28 , may be sufficiently optimized to allow the blocks  14  to act as an energy absorber within the vehicle  10 . Disposed between the fascia  12  and the bumper  16 , the blocks  14  may absorb energy displaced from the impact event. For example, the blocks  14  may be formed of a relatively rigid plastic and have a cross-section that defines a cavity  34 . The cavity  34  may further be filled with energy absorbing foam, or other energy absorbing material. This may allow the blocks  14  to further aid in absorbing energy displaced by the impact with the vehicle  10 . Likewise, the blocks  14  may act as an energy absorber. The blocks  14  may be formed from an energy absorbing material capable of receiving the energy of an impact. 
     Referring to  FIG. 5 , a perspective view of an impact with a second side  25  of the fascia  12  is shown. In order for the blocks  14  to indent the pressure tube  18  as described above, the distribution of the blocks  14  across the fascia  12  may be continuous. Further, the blocks  14  may be evenly distributed across the fascia  12  of the vehicle  10 . The block distribution on a first side  24  of the fascia  12  may complement the block distribution on a second side  25  of the fascia  12 . This allows for the change in volume in the pressure tube  18  to be uniform across the entire fascia  12  of the vehicle  10 . The uniformity of the block distribution allows the impact force to be evenly distributed across the blocks  14 . 
     The blocks  14  may have a variety of different shapes with a variety of different geometric ratios. For example, the blocks  14  may be small, thin, and numerous, continuously formed along the curvature of the fascia  12 . The blocks  14  may be more numerous toward the center  22  of the vehicle  10 . This is due to the center  22  of the vehicle  10  being a high force impact location. As stated previously, the blocks  14  may have a smaller contact area  28  at the center  22  of the vehicle  10 . This may allow for more blocks  14  disposed at the center  22  of the vehicle  10 . Likewise, the number of blocks  14  may decline as the blocks  14  move away from the center  22  of the vehicle  10 . 
     The fine nature of the blocks  14  allows for a more accurate pressure reading from the pressure sensor  20  of the change in volume in the pressure tube  18 . After an impact has occurred, the fine nature of the blocks  14  and the even distribution of the blocks  14  across the fascia  12  allow the blocks  14  to more precisely indicate the magnitude of the impact force. 
     Utilizing small, fine, and continuous blocks  14  across the fascia  12  may result in a more accurate pressure signal sent from the pressure sensor  20  to the controller  32 . The small nature of the blocks  14  minimizes the distance between the blocks  14 . Therefore, the entire force component from the impact event is being mapped on the pressure tube  18 . Having a more precise map of the magnitude of the force further allows the controller  32  to accurately classify the impact event. More accurately classifying the impact event further aids the controller deployment control logic determination. This enables the protection algorithm to further discriminate between deployment events using a single pressure sensor  20 . 
     The blocks  14  may be mounted to the back of the fascia  12 . This may include mechanically fastening the blocks  14  with, for example, rivets or screws. The blocks  14  may also be mounted to the fascia  12  through bonding techniques, such as adhesive bonding or gluing. Further, the blocks may be joined to the fascia  12 , such as, through ultrasonic welding. In a further embodiment, the blocks  14  may be formed as part of the fascia  12 , or molded directly to the fascia  12 . 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.