Patent Publication Number: US-2023142505-A1

Title: Repair method for chassis rails of vehicles

Description:
INTRODUCTION 
     The subject disclosure relates to chassis rails of vehicles, and more particularly relates to a method of repairing chassis rails. 
     Current production vehicles, such as an automobile, are originally equipped with impact protection components for absorbing a kinetic energy pulse generated from an impact event between the vehicle and an external object. The most prevalent type of impact protection component is the front and rear vehicle bumper structure. A vehicle bumper is normally composed of a high-strength yet deformable crossbeam that is rigidly secured to the body in white (BIW) chassis and covered by an A-surface cladding (more commonly known as a “bumper fascia”). Chassis rails of the BIW chassis and the bumper crossbeams are typically designed to deform in a controlled and predictable manner to optimize impact energy absorption, while the bumper fascia is merely provided as an aesthetically appealing shell for concealing the crossbeam. 
     SUMMARY 
     In one exemplary embodiment, a method of repairing a chassis rail for a vehicle is provided. The method includes that a marking is identified on the chassis rail. The marking indicating where to cut the chassis rail. The method also includes that the chassis rail is cut proximate the marking to form a cut chassis rail portion. The method further includes a replacement rail assembly is slid onto the cut chassis rail portion. The replacement rail assembly including a replacement rail, an inner brace portion secured within the replacement rail, and a bracket wrapped at least partially around the replacement rail and secured to the replacement rail. The bracket including one or more fastener through-passages. The method further includes the replacement rail assembly is secured to the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that that the replacement rail assembly is secured to the cut chassis rail portion by securing the replacement rail assembly to the cut chassis rail portion using one or more fastening mechanisms. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly is secured to the cut chassis rail portion by bolting the replacement rail assembly to the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the inner brace portion includes one or more through-passages. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly is secured to the cut chassis rail portion by marking a location of each of the one or more fastener through-passages of the bracket on the cut chassis rail portion, drilling one or more through holes in the cut chassis rail portion where the location of each of the one or more fastener through-passages was marked on the cut chassis rail portion, aligning the one or more through holes with the one or more fastener through-passages and the one or more through-passages, inserting a fastening mechanism into the aligned fastener through-passages, through holes, and through-passages, and securing the replacement rail assembly to the cut chassis rail portion with the fastening mechanism. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the bracket is welded to the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the bracket is welded to the replacement rail. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the inner brace portion is welded to the replacement rail. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that after marking the location of each of the one or more fastener through-passages on the replacement rail and before drilling the one or more through holes in the cut chassis rail portion where the location of each of the one or more fastener through-passages was marked, the method further includes sliding the replacement rail off the cut chassis rail portion in order to drill the one or more through holes where the location of each of the one or more fastener through-passages was marked. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that after drilling the one or more through holes in the cut chassis rail portion and before aligning the one or more fastener through-passages and the one or more through-passages, the method further includes sliding the replacement rail back onto the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that after drilling the one or more through holes in the cut chassis rail portion and before aligning the one or more fastener through-passages and the one or more through-passages, the method further includes applying an anticorrosive weldable primer onto the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that after drilling the one or more through holes in the cut chassis rail portion was marked on the cut chassis rail portion and before aligning the one or more fastener through-passages and the one or more through-passages, the method further includes applying an anticorrosive weldable primer onto the cut chassis rail portion and sliding the replacement rail back onto the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the chassis rail is a front chassis rail of the vehicle. 
     In one exemplary embodiment, a cut chassis rail portion. The repaired chassis rail also includes a replacement rail assembly secured to the cut chassis rail portion. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly is secured to the cut chassis rail portion via one or more fastening mechanisms. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly is secured to the cut chassis rail portion via one or more welds. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly is secured to the cut chassis rail portion via one or more bolts. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly is secured to the cut chassis rail portion via one or more rivets. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the replacement rail assembly further includes a replacement rail, a bracket wrapped at least partially around the replacement rail, and an inner brace portion secured within the replacement rail. 
     In addition to one or more of the features described herein, or as an alternative, further embodiments may include one or more fastening mechanisms. The replacement rail, the bracket, the inner brace portion, and the cut chassis rail portion are secured together via the one or more fastening mechanisms. 
     The above features and advantages, and other features and advantages of the disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features, advantages and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which: 
         FIG.  1    is a front perspective view of a vehicle that includes a left front chassis rail and a right front chassis rail; 
         FIG.  2    is a perspective view of a left front chassis rail with a marking and a right front chassis rail with a marking, according to an embodiment of the present disclosure; 
         FIG.  3    is a perspective view of an aft section of the left front chassis rail and a replacement rail, according to an embodiment of the present disclosure; 
         FIG.  4    is an axial view of the replacement rail assembly, according to an embodiment of the present disclosure; and 
         FIGS.  5 A,  5 B,  5 C, and  5 D  are a flow diagram illustrating a method of repairing the front chassis rail of a vehicle, according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     A chassis of a vehicle is often difficult to repair after a collision. The embodiments disclosed herein seek to provide a method for repairing a front chassis rail by removing a damaged forward portion of the front chassis rail and replacing the damaged forward portion with a replacement rail that is secured to an aft section of the front chassis rail that was not damaged. 
     Referring now to  FIG.  1   , a front perspective view of a vehicle  100  is illustrated and portrayed herein for purposes of discussion as a sports utility vehicle (SUV). The vehicle  100  is merely an exemplary application with which the novel aspects and features of this disclosure may be practiced. As such, it is understood that the embodiments disclosed herein are not limited to SUVs and the embodiments disclosed here may be applicable to other vehicles. 
     The vehicle  100  includes a front end  102  and a rear end  104  located opposite the front end  102 . The vehicle  100  also includes a passenger compai tinent  112 . 
     For purposes of this Detailed Description, relative clauses and spatial adjectives, such as “front,” “rear,” “vertical” and “horizontal,” are with respect to the vehicle  100  and forward and reverse driving directions of the vehicle  100 . In the abridged perspective view of the chassis  118  inset into  FIG.  1    there is shown a pair of longitudinally oriented front chassis rails  128  interconnected by a U-shaped box- girder crossmember  124 . The pair of front chassis rails  128  are located at a front of the chassis  118  proximate the front end  102  of the vehicle  100 . The front chassis rails  128  define a load travel path during a frontal impact event. Other under body structures and related features are deemed to be within the scope of this disclosure. The front chassis rails  128  are configured to connect to a bumper  114  at a forward end  132  of the front chassis rails  128  proximate the front end  102  of the vehicle  100 . The front chassis rails  128  are configured to connect to a main portion  144  of the chassis at a rearward end  134 . 
     The front chassis rails  128  may include a left front chassis rail  128   a  located on a left side  106  of the vehicle  100  and a right front chassis rail  128   b  located on a right side  108  of the vehicle  100 . The embodiments described herein are applicable to both the left front chassis rails  128   a  and the right front chassis rail  128   b . It is understood that while front chassis rails  128  are described herein, the embodiments disclosed herein are also applicable to rear chassis rails or any other chassis rail of the vehicle  100 . 
     Referring now to  FIG.  2   , with continued reference to  FIG.  1   , a perspective view of the left front chassis rail  128   a  and the right front chassis rail  128   b  is illustrated in accordance with an embodiment of the present disclosure. During a frontal impact, the chassis rails  128  may be configured to deform inwardly from the forward end  132  up to a selected distance D 1  at certain vehicle speeds to absorb energy from the collision. In order words, a forward section S 1  of the chassis rail  128  located proximate the forward end  132  is configured to compress (up to a selected vehicle speed) while an aft section S 2  of the chassis rails  128  proximate the rearward end  134  is configured to not compress or remain rigid (up to the selected vehicle speed). The aft section S 2  may also be referred to as a cut chassis rail portion  129  (See  FIG.  3   ) after the forward section S 1  has been removed. Above the selected vehicle speed both the forward section S 1  and the aft section S 2  of the chassis rails  128  may compress. 
     Since the aft section S 2  of a chassis rail  128  is configured to not compress at vehicles speeds below the selected vehicle speed then the aft section S 2  may remain undamaged while the forward section S 1  of the chassis rail  128  may be removed and replaced in accordance with a method describe further herein. 
     As illustrated in  FIG.  2   , each of the left front chassis rail  128   a  and the right front chassis rail  128   b  may include a marking  150  indicating where each front chassis rail  128  may be cut after a crash using the repair method further described herein. The marking  150  may be located at the first distance D 1  from the forward end  132  of the front chassis rail  128 . The marking  150  indicates that the front chassis rail  128  may be cut at or forward of the marking  150 . As illustrated in  FIG.  2   , the marking  150  may include an arrow pointing toward the forward end  132  of the front chassis rail  128  and a cut line located forward of the arrow. 
     The marking  150  may be an emblem, logo, symbol, text, pictograph, pictograph, ideogram, or any similar marking. The marking  150  may be attached to the front chassis rail  128  (e.g., sticker or decal on the front chassis rail  128 ), etched into the front chassis rail  128 , printed onto the front chassis rail  128 , embedded into the front chassis rail  128 , embossed into the front chassis rail  128 , stamped into the front chassis rail  128 , or applied to the front chassis rail  128  using any other method known to one of skill in the art. 
     Referring now to  FIG.  3   , with continued reference to  FIGS.  1  and  2   , a perspective view of the left front chassis rail  128   a  after the forward section S 1  has been removed or cut off is illustrated, according to an embodiment of the present disclosure. It is understood that while  FIG.  3    and the associated description discuss the left front chassis rail  128   a , the embodiments discussed are equally applicable to the right front chassis rail  128   b.    
     A perspective view of a replacement rail assembly  200  is also illustrated in  FIG.  3   , according to an embodiment of the present disclosure. The replacement rail assembly  200  is configured to slide onto the cut end  170  of the cut chassis rail portion  129  of the left front chassis rail  128   a  and then be securely attached thereto. The replacement rail assembly  200  includes a front replacement rail  202  that is configured to be a functional replica of the forward section S 1  of the left front chassis rail  128   a.    
     The replacement rail assembly  200  includes an inner brace portion  204  and a bracket  220 . The inner brace portion  204  is located within the front replacement rail  202  and the bracket  220  is wrapped at least partially around the front replacement rail  202 . The inner brace portion  204  is configured to slide into or within the cut end  170  of the cut chassis rail portion  129  and the bracket  220  is configured to slide over the cut end  170  of the cut chassis rail portion  129  when the replacement rail assembly  200  is installed. The front replacement rail  202  is configured to abut the cut end  170  of the cut chassis rail portion  129  when the replacement rail assembly  200  is installed. 
     The replacement rail assembly  200  may be secured to the left front chassis rail  128   a  via the bracket  220 , one or more fastening mechanisms  230 , a weld between the bracket  220  and the replacement rail assembly  200 , and a weld between the bracket  220  and the left front chassis rail  128   a , as discussed further herein. 
     Referring now to  FIG.  4   , with continued reference to  FIGS.  1 - 3   , an axial view of the replacement rail assembly  200  is illustrated, according to an embodiment of the present disclosure. It is understood that while  FIG.  4    and the associated description discuss the left front chassis rail  128   a , the embodiments discussed are equally applicable to the right front chassis rail  128   b.    
     As illustrated in  FIG.  4   , the replacement rail assembly  200  may be secured to the left front chassis rail  128   a  using the bracket  220  and one or more fastening mechanisms  230 . The bracket  220  is secured to the front replacement rail  202  by one or more metal inert gas welds (MIG) welds (not visible in  FIG.  4   ). It is understood that while MIG welds are described herein to secure the bracket  220  to the front replacement rail  202 , any type of weld known to one of skill in the art may be utilized. The inner brace portion  204  is secured to the front replacement rail  202  by one or more metal inert gas welds (MIG) welds  302  and one or more puddle welds  304 . It is understood that while MIG welds  302  and puddle welds  304  are described herein to secure the inner brace portion  204  to the front replacement rail  202 , any type of weld known to one of skill in the art may be utilized. 
     The bracket  220  wraps at least partially around an outer perimeter of the front replacement rail  202  and the left front chassis rail  128   a  proximate the cut end  170  after the cut end is inserted into the replacement rail assembly  200 . The bracket  220  is secured to the left front chassis rail  128   a  by one or more metal inert gas welds (MIG) welds (not shown). It is understood that while MIG welds (Not shown) are described herein to secure the bracket  220  to the front replacement rail  202 , any type of weld known to one of skill in the art may be utilized. 
     Three fastening mechanisms  230  may be utilized to secure the replacement rail assembly  200  to the left front chassis rail  128   a . The fastening mechanism  230  may be a bolt and nut, a blind rivet, or similar fastening mechanism. 
     The inner brace portion  204  of the replacement rail assembly  200  comprises one or more through-passages  240 . The bracket  220  includes one or more fastener through-passages  222  that are configured to align with the one or more through-passages  240 . The fastener through-passages  222  are used as a template to drill through holes  180  (see  FIG.  5 C ) in the front chassis rail  128 , as discussed in Method  500 . The fastener through-passage  222 , the through hole  180  (see  FIG.  5 C ), and the through-passage  240  are all configured to align with each other to allow the fastening mechanism  230  to be inserted through and secure the replacement rail assembly  200  to the front chassis rail  128 . 
     Referring to  FIGS.  5 A,  5 B,  5 C, and  5 D , with continued reference to  FIGS.  1 - 4   , a method  500  of repairing a front chassis rail  128  for a vehicle  100  is illustrated, in accordance with an embodiment of the present disclosure. The method  500  may be applicable to the left front chassis rail  128   a  or the right front chassis rail  128   b  of the vehicle  100 . It is understood that while the method  500  is described using the front chassis rail  128 , the method is also applicable to any chassis rail of the vehicle  100  including but not limited to a rear chassis rail. 
     At block  504 , a marking  150  is identified on the front chassis rail  128 . The marking  150  indicating where to cut the front chassis rail  128 . At block  506 , spot welds  410  that join the front chassis rail  128  to a wheelhouse  400  of the vehicle  100  are removed or any other vehicle chassis member. 
     Block  506  may be optional if the front chassis rail  128  is not joined to the wheelhouse  400 . Block  506  may occur prior to block  504 . 
     At block  508 , the front chassis rail  128  is cut proximate the marking  150  to form a cut chassis rail portion  129 . This separates the front chassis rail  128  into the first section S 1  and the cut chassis rail portion  129 . The front chassis rail  128  may be cut forward of the marking  150  or at the marking  150 . 
     At block  510 , a replacement rail assembly  200  is slid onto the cut chassis rail portion  129 . The replacement rail assembly  200  of method  500  includes at least the front replacement rail  202 , the inner brace portion  204 , and the bracket  220 . The inner brace portion  204  may be welded within and onto the front replacement rail  202  prior to method  500  to form the replacement rail assembly  200 . The bracket  220  may also be welded onto the front replacement rail  202  prior to method  500 . 
     The inner brace portion  204  of the replacement rail assembly  200  comprises one or more through-passages  240  (see  FIG.  4   ). The bracket  220  includes one or more fastener through-passages  222  that are configured to align with the one or more through-passages  240 . 
     Following block  510 , the replacement rail assembly  200  may be secured to the front chassis rail  128 . The replacement rail assembly  200  may be secured to cut chassis rail portion  129  via one or more different methods and/or using one or more fastening mechanisms  230 . The replacement rail assembly  200  may be secured to cut chassis rail portion  129  by bolting the replacement rail assembly  200  to the cut chassis rail portion  129 . The replacement rail assembly  200  may be secured to cut chassis rail portion  129  by welding the replacement rail assembly  200  to the cut chassis rail portion  129 . The replacement rail assembly  200  may be secured to cut chassis rail portion  129  by riveting the replacement rail assembly  200  to the cut chassis rail portion  129 . 
     The replacement rail assembly  200  may be secured to cut chassis rail portion  129  via blocks  512 - 520 . 
     At block  512 , a location of each of the one or more fastener through-passages  222  is marked on cut chassis rail portion  129 . Block  512  occurs while the front replacement rail  202  is on the cut chassis rail portion  129 . The one or more fastener through-passages  222  may be used as stencils to sketch/mark the correct location of the one or more fastener through-passages  222  on the cut chassis rail portion  129 , so that they will later align will through holes  180  drilled later in block  514 . 
     At block  514 , one or more through holes  180  are drilled in the cut chassis rail portion  129  to align with the one or more fastener through-passages  222  and the one or more through-passages  240 . The one or more through holes  180  are drilled in the cut chassis rail portion  129  where the location of each of the one or more fastener through-passages  222  was marked on the cut chassis rail portion  129 . The replacement rail assembly  200  may be removed from the cut chassis rail portion  129  prior to the drilling at block  514  in order to drill the one or more through holes  180  therein. Alternatively, the drilling in block  514  may occur when the replacement rail assembly  200  is located on the cut chassis rail portion  129 . If the replacement rail assembly  200  was removed from the cut chassis rail portion  129  prior to the drilling at block  514  then post block  514  the replacement rail assembly  200  may be slid back onto the cut chassis rail portion  129 . An anticorrosive weldable primer may be applied onto the cut chassis rail portion  129  following the drilling in block  514 . 
     At block  516 , the one or more through holes  180  are aligned with the one or more through-passages  240  and the one or more fastener through-passages  222  by sliding the replacement rail assembly  200  into engagement with the cut chassis rail portion  129 . 
     At block  518 , a fastening mechanism  230  is inserted into each of the aligned fastener through-passages  222 , through holes  180 , and through-passages  240 . 
     At block  520 , the replacement rail assembly  200  is secured to the cut chassis rail portion  129  with the fastening mechanisms  230 . 
     At block  522 , the bracket  220  may be welded to the cut chassis rail portion  129 . This forms a repaired front chassis rail  700 , as illustrated in  FIG.  5 D . 
     The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof 
     While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope thereof.