Abstract:
An impact protection element for a sensor housed in a boss features a hollow base element adapted to overlie the boss and a pair of legs extending along opposite sides of the boss.

Description:
BACKGROUND 
     Field 
       [0001]    The disclosed teachings relate generally to impact protection for sensor elements. More specifically, the teachings are directed to impact protectors for sensors used in vehicular exhaust systems. 
         [0002]    Sensors used in, for example, automotive applications are built to withstand temperature and vibration extremes in use. However, such sensors may be prone to damage by impact with obstacles during manufacturing of the device with which they are associated, during assembly of the system, such as an automobile, in which the sensor is associated, or during use of the system. 
         [0003]    Hence, there is seen to be a need in the art for an impact preventing device for such sensors. 
       SUMMARY 
       [0004]    Accordingly, a protection element for a sensor associated with an exhaust system of a vehicle includes a hollow base portion adapted for at least partially surrounding a longitudinal axis of an associated sensor, and first and second legs extending from the base portion and adapted for coupling to a device of the exhaust system. 
         [0005]    In another aspect of the disclosed teachings, an automotive exhaust treatment device includes a sensor mounting boss housing a sensor and extending from a surface of the exhaust treatment device. A sensor protector having a base portion positioned above the mounting boss additionally includes first and second legs extending from the base portion and fixedly coupled to the surface on opposite sides of the boss. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0006]    The objects and features of the invention will become apparent from a reading of a detailed description, taken in conjunction with the drawing, in which: 
           [0007]      FIG. 1   a  is a perspective view of a piece of tubing showing cutting lines for producing two sensor protectors arranged in accordance with the principles of the disclosed teachings; 
           [0008]      FIG. 1   b  is a perspective view of two sensor protectors fashioned by cutting the tubing along the cutting lines shown in  FIG. 1   a;    
           [0009]      FIG. 2  is a side view of the tubing of  FIG. 1   a  prior to cutting it into two sensor protectors in accordance with the principles of the disclosed teachings; 
           [0010]      FIG. 3  is a side view of the tubing of  FIG. 1   a  taken from a side opposite to that of  FIG. 2 ; 
           [0011]      FIG. 4  is a perspective view of an alternative embodiment of a sensor protector arranged in accordance with the principles of the disclosed teachings; 
           [0012]      FIG. 5  is a perspective view of the sensor protector of  FIG. 4  shown mounted for protection of a sensor associated with an exhaust treatment device in accordance with the principles of the disclosed teachings; and 
           [0013]      FIG. 6  is a perspective view of a second alternative embodiment of a sensor protection element arranged in accordance with the principles of the disclosed teachings; and 
           [0014]      FIG. 7  is a perspective view of the sensor protection element of  FIG. 6  mounted for protection of a sensor associated with an exhaust treatment device in accordance with the principles of the disclosed teachings. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    With reference to  FIGS. 1   a,    1   b,    2  and  3 , two sensor protector elements are fashioned from tubing  100  by cutting the tubing along the lines shown in  FIGS. 1   a,    2  and  3 . 
         [0016]    After the tubing is cut, the two elements shown in the exploded view of  FIG. 1   b  result in two protectors  102   a  and  102   b.  A first sensor protector  102   a  has a substantially cylindrical base portion from which first and second legs  106  and  108  extend. Similarly, sensor protection element  102   b  has a substantially cylindrical base portion with two legs  110  and  112  extending therefrom.  FIGS. 2 and 3  show side views of the tube of  FIG. 1   a  prior to cutting and separation. With this fabrication approach, the mounting legs are integral with their base portions. 
         [0017]    An alternative protection element is shown in  FIG. 4 . Sensor protection element  400  has a substantially cylindrical hollow base portion  402  from which two legs  404  and  406  extend. Legs  404  and  406  can, for example, be fixedly coupled to base portion  402  by welding or other suitable attachment processes. 
         [0018]    In automotive applications, the protection elements of  FIGS. 1-3  or  FIG. 4 , and the sensor which they are designed to protect are, for example, configured in association with an exhaust after-treatment device as shown in  FIG. 5 . 
         [0019]    Exhaust after-treatment device  500  may comprise a variety of exhaust system elements, including, without limitation, mufflers, catalytic converters, particulate filters, or simply an exhaust conduit such as an exhaust pipe or manifold. 
         [0020]    In the example shown in  FIG. 5 , after-treatment device  500  has an inlet conduit  504  at one end of its housing  502 . Extending outwardly from inlet tube  504  is a sensor and sensor mounting boss  506 . As seen from  FIG. 5 , sensor protection element  400  (as shown in  FIG. 4 ) is placed such that its base portion  402  overlies mounting boss  506  while legs  404  and  406  extend from base portion  402  on opposite sides of mounting boss  506  and are fixedly coupled to the device at its inlet  504  by suitable attachment means, such as welding. Base portion  402  may be open at its end allowing for the passage of a sensor cable  508  which, in most applications would extend to a unit utilizing the sensor signals, such as an engine control unit of a motor vehicle. 
         [0021]    Surrounding cable  508  as it exits boss  506  is a hardened cable shield  510  fashioned, for example, from a metallic substance. Shield  510  extends from boss  506  through and beyond the boss portion  402  of sensor protection element  400 . In this way, during assembly or in use, cable  508  will not be damaged by coming into contact with protection element  400 . 
         [0022]    A second alternative embodiment of a sensor protection element  600  is set forth in  FIG. 6 . Protection element  600  has first and second mounting legs  604  and  605  and a 3-walled base portion  602  adapted to extend along three sides of a longitudinal axis of a sensor being protected. Each wall of the base portion  602  has an associated aperture  606 ,  608  and  610 . Base portion  602  terminates at its end opposite mounting legs  604  and  605  at edge surface  612 . 
         [0023]      FIG. 7  sets forth an example application of sensor protection element  600  in an automotive exhaust system environment. As with the application example of  FIG. 5 , exhaust after-treatment device  700  may comprise a variety of exhaust system components, including, without limitation, mufflers, catalytic converters, particulate filters, or simply an exhaust conduit such as an exhaust pipe or manifold. 
         [0024]    As seen from  FIG. 7 , a sensor and sensor mounting boss  702  extends from after-treatment device  700 . Mounted to device  700  on opposite sides of boss  702  are legs  604  and  605  of protection element  600 . Base portion  602  extends along three sides around a longitudinal axis of sensor and sensor boss  702  so as to surround sensor cable  704  and its cable shield  706 . The open face of base portion  602  faces the vehicle undercarriage or any exhaust system or vehicle component providing a natural impact shield at that side of the sensor boss. 
         [0025]    Sensor protection elements arranged as shown in the teachings herein are suitable for use with a wide variety of sensors, including, without limitation, oxygen sensors, temperature sensors, pressure sensors, nitrous oxide sensors, ammonia sensors, etc. 
         [0026]    The detailed description has been set forth for the sake of example only and is not to be construed as a limitation on the invention. The invention will be found in the appropriately interpreted appended claims.