Patent Publication Number: US-2007102965-A1

Title: Hydroformed windshield surround frame for vehicles and method of making same

Description:
TECHNICAL FIELD  
      The present invention relates generally to vehicles and, more particularly, to a hydroformed windshield surround frame for a vehicle and method of making same.  
     BACKGROUND OF THE INVENTION  
      It is known to provide a windshield for a vehicle such as an automotive vehicle. Typically, the windshield is mounted to a vehicle body of the vehicle by a frame. This frame is commonly called a “windshield surround frame” (WSF). Typically, the WSF is constructed out of multiple stamped pieces.  
      It is also known to hydroform tubular components or members. Hydroformed tubular members are becoming increasingly popular in automotive body structural applications. During vehicle body manufacturing, many of the hydroformed tubular members are used in vehicle body and chassis applications. However, in one known application for a vehicle, the WSF is made out of multiple hydroformed pieces welded together.  
      As a result, it is desirable to provide a new windshield surround frame for a vehicle that reduces overall cost in part fabrication and assembly. It is also desirable to provide a new windshield surround frame for a vehicle that provides better product performance (stiffness) and better quality (dimensional performance). It is further desirable to provide a new method of making a hydroformed windshield surround frame for a vehicle that eliminates multiple parts or welding. Therefore, there is a need in the art to provide a new windshield surround frame and method of making same that meets these desires.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is a hydroformed windshield surround frame for a vehicle including a top portion extending laterally, a pair of opposed pillar portions extending generally perpendicular from the top portion, and a pair of corner portions interconnecting the top portion and the pillar portions. The top portion, the pillar portions, and the corner portions form a monolithic structure being integral, unitary, and one-piece.  
      Also, the present invention is a method of making a hydroformed windshield surround frame for a vehicle. The method includes the steps of providing a tubular member and bending the tubular member to form a bent tubular member. The method also includes the steps of hydroforming the bent tubular member into a windshield surround frame having a monolithic structure being integral, unitary, and one-piece.  
      One advantage of the present invention is that a hydroformed windshield surround frame is provided for a vehicle, which eliminates multiple pieces of traditional stamped parts. Another advantage of the present invention is that a method of making a hydroformed windshield surround frame is provided for a vehicle, which eliminates multiple hydroformed pieces welded together. Yet another advantage of the present invention is that the hydroformed windshield surround frame and method reduces part fabrication cost and assembly cost. Still another advantage of the present invention is that the hydroformed windshield surround frame and method provides improved product performance (stiffness) and quality (dimensional performance).  
      Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a vehicle incorporating a hydroformed windshield surround frame, according to the present invention.  
       FIG. 2  is a perspective view of the hydroformed windshield surround frame and a windshield frame assembly of  FIG. 1 .  
       FIG. 3  is an exploded perspective view of the hydroformed windshield surround frame and windshield frame assembly of  FIG. 2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to the drawings and in particular  FIG. 1 , a vehicle  10  is shown incorporating one embodiment of a windshield frame assembly  12 , according to the present invention. The vehicle  10  includes a vehicle body  14  supported by surrounding structural members (not shown). The windshield frame assembly  12  is attached to and supported by the vehicle body  14 . It should be appreciated that, except for the windshield frame assembly  12 , the vehicle  10  is conventional and known in the art.  
      Referring to  FIGS. 2 and 3 , the windshield frame assembly  12  includes a base support member  16  extending laterally. The windshield frame assembly  12  also includes at least one, preferably a pair of side members  18  with one side member  18  attached to each of the sides of the base support member  16 . In one embodiment, the side members  18  extend generally vertically and have a generally “C” cross-sectional shape. The windshield frame assembly  12  includes an upper support member  20  extending laterally and disposed between the side members  18 . The windshield frame assembly  12  includes at least one, preferably a pair of arm members  22  with one arm member  22  attached to each of the side members  18 . In one embodiment, the arm members  22  are each generally “L” shaped and have a generally tubular cross-sectional shape. The windshield frame assembly  12  further includes a hydroformed windshield surround frame  24 , according to the present invention, attached to the upper support member  20  and to each of the arm members  22 .  
      In one embodiment, the hydroformed windshield surround frame  24  is a tubular member having a generally inverted “U” shape. The hydroformed windshield surround frame  24  has a top portion  26  extending laterally and a pillar portion  28  extending generally perpendicular from each end of the top portion  26 . The hydroformed windshield surround frame  24  also has a corner portion  30  between the top portion  26  and each pillar portion  28 . The corner portion  30  is generally curved or arcuate in shape. The hydroformed windshield surround frame  24  has different cross-sectional shapes such as rectangular, oval, or multi-faceted along the top portion  26 , pillar portion  28 , and corner portion  30 . The hydroformed windshield surround frame  24  is made of a metal material such as steel, stainless steel, or aluminum and formed by a hydroforming process. The hydroformed windshield surround frame  24  is a monolithic structure being integral, unitary, and one-piece. It should be appreciated that, in certain applications, stainless steel is used for the hydroformed windshield surround frame  24  in order to achieve higher strength along with adequate ductility (for tight bends). It should also be appreciated that the hydroforming process is used in order to achieve different cross-sectional shapes. It should further be appreciated that the different cross-sectional shapes of the hydroformed windshield surround frame  24  provides both structural load path (for stiffness, etc.) and mounting areas for surrounding members (e.g., windshield, brackets, etc.).  
      For assembly of the windshield frame assembly  12 , the upper support member  20  is disposed between the pillar portions  28  of the hydroformed windshield surround frame  24 . The upper support member  20  is welded and joined to the hydroformed windshield surround frame  24 . The hydroformed windshield surround frame  24  is disposed between the two arm members  22 . The windshield surround frame  24  is welded and joined to the arm members  22 . The arm members  22  are disposed inside of the side members  18  and the base support member  16  is disposed between the side members  18 . The side members  26  are welded and joined to the base support member  16  and the arm members  22  are welded and joined to the side members  26 . It should be appreciated that conventional joining techniques such as spot welding, brazing, adhesives, laser, fasteners, etc., can be used to integrate the hydroformed windshield surround frame  24  with the rest of the windshield frame assembly  12 .  
      One embodiment of a method, according to the present invention, of making a hydroformed windshield surround frame  24  is disclosed. The method includes the step of providing a tubular member or blank (not shown). The tubular member has either a circular or non-circular cross-sectional shape. The method includes the step of bending the tubular member into a bent tubular member. In order to create tight bend corners, hydro-bending can be used. In this method, general shape bends are created using a rotary draw bender (not shown) to form the bent tubular member. For example, larger cross-sectional corner radii in selected bend areas allow for tighter bends. It should be appreciated that this method is suggested only when tight corner bend radii are required.  
      According to one method of hydroforming, the bent tubular member is placed in a die set (not shown) comprised of an upper die half and a lower die half. The ends of the bent tubular member are sealed and hydraulic fluid is pumped into the bent tubular member under pressure. The upper die half and lower die half are progressively closed so that the bent tubular member is progressively deformed and the pressurized fluid captured therein expands the walls of the bent tubular member into cavity portions of the die halves. It should be appreciated that, when the bent tubular member is placed in the hydroform die, further bending near the corners is achieved during the closing with fluid pressure inside the bent tubular member.  
      Once the die is closed, the bent tubular member is then expanded to a final cross-sectional profile by increasing the hydraulic pressure sufficient to exceed the yield limit of the bent tubular member so that the bent tubular member is forced into conformity with the cavity portions of the die halves. The die halves are then opened to permit removal of the finished hydroformed windshield surround frame  24  from the die halves. It should be appreciated that other methods of hydroforming may involve substitution of pre-forming for the initial pressure stage.  
      The method also includes the step of providing a base support member  16 , side members  18 , upper support member  20 , and arm members  22  and joining the base support member  16 , side members  18 , upper support member  20 , arm members  22 , and hydroformed windshield surround frame together. The method includes the step of welding the upper support member  20  and hydroformed windshield surround frame  24  together. The method further includes the step of welding the arm members  22  and the hydroformed windshield surround frame  24  together. The method includes the step of welding the arm members  22  and the side members  18  together. The method further includes the step of welding the base support member  16  and the side members  18  together to form the windshield frame assembly  12 . It should be appreciated that the welds may be spot, laser, and/or continuous.  
      The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.  
      Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.