Air flow device for a motor vehicle

Abstract

A venting mechanism for a motor vehicle having an air channel and a grating which covers the flow cross section of the air channel, a flow obstacle being arranged upstream from the grating. In order to equalize the flow in the flow cross section with the lowest possible pressure drop, in particular when only a small installation space is available, the grating has an uneven arrangement of openings so that a high degree of obstruction is achieved in a reduced-flow area of the venting cross section and a low degree of obstruction is achieved in a flow-through area of the ventilation cross section.

1 . Ventilation device for a motor vehicle, having an air duct and a discharge opening adjoining and downstream from the air duct, and a grate passing through a flow cross section of the air duct, a flow obstruction being situated upstream from the grate, wherein to compensate for the pressure differences caused by the flow obstruction, the grate is non-uniformly penetrated by openings in its flow cross section, so that the grate has a large obstruction in a blocked region of the ventilation cross section and has a small obstruction in a flowthrough region of the ventilation cross section.  
   
   
       2 . Ventilation device according to  claim 1 , wherein the openings for forming different sizes of obstructions in the surface of the grate are separated by different distances from one another.  
   
   
       3 . Ventilation device according to  claim 1 , wherein the openings for forming different sizes of obstructions in the surface of the grate have different cross-sectional areas.  
   
   
       4 . Ventilation device according to  claim 1 , wherein the openings for forming different sizes of obstructions in the surface of the grate have different cross-sectional shapes.  
   
   
       5 . Ventilation device according to  claim 1 , wherein the grate has different degrees of obstruction inside the blocked region.  
   
   
       6 . Ventilation device according to  claim 1 , wherein the grate has different degrees of obstruction inside the flowthrough region.  
   
   
       7 . Ventilation device according to  claim 5 , wherein the grate has different degrees of obstruction inside the flowthrough region.  
   
   
       8 . Ventilation device according to  claim 7 , wherein the degree of obstruction in the grate constantly changes along at least one longitudinal extension in the surface of the grate.  
   
   
       9 . Ventilation device according to  claim 1 , wherein upstream from the grate a deflection in the duct is provided along a curve which acts as a flow obstruction, and the blocked region is associated with an outwardly curving cross-sectional region and the flowthrough region is associated with an inwardly curving cross-sectional region in the grate.  
   
   
       10 . Ventilation device according to  claim 5 , wherein upstream from the grate a deflection in the duct is provided along a curve which acts as a flow obstruction, and the blocked region is associated with an outwardly curving cross-sectional region in the grate and the flowthrough region is associated with an inwardly curving cross-sectional region in the grate.  
   
   
       11 . Ventilation device according to  claim 6 , wherein upstream from the grate a deflection in the duct is provided along a curve which acts as a flow obstruction, and the blocked region is associated with an outwardly curving cross-sectional region in the grate and the flowthrough region is associated with an inwardly curving cross-sectional region in the grate.  
   
   
       12 . Ventilation device according to  claim 7 , wherein upstream from the grate a deflection in the duct is provided along a curve which acts as a flow obstruction, and the blocked region is associated with outwardly curving cross-sectional region in the grate and the flowthrough region is associated with an inwardly curving cross-sectional region in the grate.  
   
   
       13 . Ventilation device according to  claim 1 , wherein a baffle element is situated in the air duct upstream from the grate, the flowthrough region being associated with a static flow zone of the baffle element.  
   
   
       14 . Ventilation device according to  claim 5 , wherein a baffle element is situated in the air duct upstream from the grate, the flowthrough region being associated with a static flow zone of the baffle element.  
   
   
       15 . Ventilation device according to  claim 6 , wherein a baffle element is situated in the air duct upstream from the grate, the flowthrough region being associated with a static flow zone of the baffle element.  
   
   
       16 . Ventilation device according to  claim 7 , wherein a baffle element is situated in the air duct upstream from the grate, the flowthrough region being associated with a static flow zone of the baffle element.  
   
   
       17 . Ventilation device according to  claim 13 , wherein the baffle element is a shutoff valve, a blocked region being associated with an opening slot in the shutoff valve, and the flowthrough region being associated with a pivot axis of the shutoff valve.  
   
   
       18 . Ventilation device according to  claim 14 , wherein the baffle element is a shutoff valve, a blocked region being associated with an opening slot in the shutoff valve, and the flowthrough region being associated with a pivot axis of the shutoff valve.  
   
   
       19 . Ventilation device according to  claim 15 , wherein the baffle element is a shutoff valve, a blocked region being associated with an opening slot in the shutoff valve, and the flowthrough region being associated with a pivot axis of the shutoff valve.  
   
   
       20 . Ventilation device according to  claim 16 , wherein the baffle element is a shutoff valve, a blocked region being associated with an opening slot in the shutoff valve, and the flowthrough region being associated with a pivot axis of the shutoff valve.