Patent Publication Number: US-2023148335-A1

Title: Vehicle with crash impact absorbing arrangement

Description:
TECHNICAL FIELD 
     The invention relates to a vehicle comprising a frame; a cabin; a forward compartment extending from the cabin towards the front end; and a crash impact absorbing arrangement at least partly arranged in the forward compartment. 
     The invention can be applied in heavy-duty vehicles, such as trucks, buses and construction equipment. Although the invention will be described with respect to a truck, the invention is not restricted to this particular vehicle, but may also be used in other vehicles, for instance pick-up trucks or relatively large and high passenger cars. 
     BACKGROUND 
     A particularly difficult crash scenario for a truck, bus or other high vehicle is a forward collision into the back of the trailer of a heavy vehicle. In a conventional truck with a forward compartment accommodating the engine, the engine absorbs much of the energy of the impact, transfers it to the chassis frame and slows down the vehicle. This facilitates a design in which the deformation of the cabin can be minimized, which in turn reduces the risk of injury of the driver in the cabin. 
     In a fully electric vehicle, however, there is no engine in the forward compartment, which means that safety in the event of a crash scenario, including the above-described forward collision needs to achieved by other means. 
     SUMMARY 
     An object of the invention is to provide for an improved crash safety in a vehicle lacking an internal combustion engine in its forward compartment. 
     According to the invention, this object is achieved by a vehicle comprising a frame; a cabin; a forward compartment extending from the cabin towards a front end of the vehicle; and a crash impact absorbing arrangement at least partly arranged in the forward compartment, wherein the crash impact absorbing arrangement comprises: a front structure having a lower portion attached to the frame and an upper portion arranged between the cabin and the front end of the vehicle, the front structure being configured to collapse towards a rear end of the vehicle when a force directed towards the rear end of the vehicle acting on the upper portion of the front structure reaches a predefined threshold force; a rear structure having a lower portion attached to the frame and an upper portion, the rear structure being configured to withstand a force directed towards the rear end of the vehicle acting on the upper portion of the rear structure exceeding the predefined threshold force; and at least one deformable energy absorbing structure arranged between the upper portion of the front structure and the upper portion of the rear structure, and configured to transfer a force directed towards the rear end of the vehicle acting on the upper portion of the front structure to the upper portion of the rear structure, while being deformed to allow movement of the upper portion of the front structure towards the upper portion of the rear structure. 
     The present invention is based on the realization that the energy absorbing functionality of a forward mounted internal combustion engine can be fulfilled by a crash impact absorbing arrangement with a relatively weak front structure, a relatively strong rear structure and at least one deformable energy absorbing structure connecting upper portions of the front structure and the rear structure. With the provision of such a crash impact absorbing arrangement, the present inventor has found that the safety in the event of a crash scenario, including a forward collision, can be maintained or improved in the absence of a forward mounted internal combustion engine. Furthermore, the crash impact absorbing arrangement comprised in the vehicle according to various embodiments of the present invention may also reduce the tendency of the vehicle to pitch forward in the event of a forward collision, which also provides for improved integrity of the cabin. 
     According to embodiments, the upper portion of the rear structure may be arranged between the cabin and the upper portion of the front structure. This configuration may provide for further improved integrity of the cabin space. 
     According to embodiments of the present invention, the vehicle may be a relatively high vehicle, such as a truck or a bus, and the crash impact absorbing arrangement may then be particularly effective for handling a forward collision into the back of another high vehicle, particularly a trailer, such as corresponding to a Trailer back vehicle impact testing situation. 
     For particularly efficient handling of this kind of forward collision, the upper portion of the front structure may be arranged at least 0.5 meter above road level. More advantageously, the upper portion of the front structure may be arranged at least 1 meter above road level. This high arrangement of the upper portion of the front structure increases the probability that the upper portion of the front structure can start to absorb energy of the collision at an early stage from an upper barrier impact and transfer load to the chassis frame, providing for improved safety. 
     In embodiments, furthermore, the upper portion of the rear structure may be arranged at least 0.5 meter above road level. More advantageously, the upper portion of the rear structure may be arranged at least 1 meter above road level. In particular, the upper portion of the rear structure may advantageously be arranged at substantially the same height as the upper portion of the front structure. This configuration may further improve the load transfer dynamics in the event of a forward collision, and reduce the tendency of the vehicle to pitch forward. 
     The front structure may be configured in various ways for it to collapse backwards when the upper portion thereof is subjected to a sufficiently large force. According to one embodiment, the lower portion of the front structure may be attached to the frame by an attachment structure designed to fail when a force directed towards the rear end of the vehicle acting on the upper portion of the front structure reaches the predefined threshold force. The attachment structure may be any suitable attachment structure, such as bolts, brackets, welds, or any other attachment structure used in vehicle manufacturing. As an alternative or complement, the front structure itself may be dimensioned to be deformed when a sufficiently large force is acting on the upper portion thereof. 
     According to embodiments, the lower portion of the rear structure may be attached to the frame by an attachment structure designed to remain intact when a force directed towards the rear end of the vehicle acting on the upper portion of the rear structure reaches the predefined threshold force. The attachment structure may be any suitable attachment structure, such as bolts, brackets, welds, or any other attachment structure used in vehicle manufacturing. 
     In embodiments, the attachment structure attaching the front structure to the frame and the attachment structure attaching the rear structure to the frame may be different. For instance, the front structure may be attached to the frame by bolts and the rear structure may be attached to the frame by welds, or both the front and rear structures may be attached to the frame by welds, but a larger number of welds may be used for attaching the rear structure, etc. 
     According to various embodiments, furthermore, the crash impact absorbing arrangement may further comprise at least one strut arranged between the upper portion of the rear structure and the frame. This at least one strut may act to ensure that the rear structure withstands a backwards force acting on the upper portion of the rear structure exceeding the predefined threshold force. As an alternative or complement, the rear structure of the crash impact absorbing arrangement may be made of high-strength steel. 
     In embodiments, the longitudinal distance between the upper portion of the front structure and the upper portion of the rear structure may be at least 0.5 meter. More advantageously, the longitudinal distance between the upper portion of the front structure and the upper portion of the rear structure may be at least 1 meter. This minimum distance may facilitate the design of the at least one deformable energy absorbing structure arranged between the upper portion of the front structure and the upper portion of the rear structure. 
     To achieve efficient use of the space in the forward compartment, and also to protect the cooling system of the vehicle, the upper portion of the front structure may surround at least a portion of the cooling system, such as a front fan of the cooling system. 
     In summary, embodiments of the present invention thus relate to a vehicle comprising a crash impact absorbing arrangement including a front structure having a lower portion attached to the frame and an upper portion arranged between the cabin and the front end of the vehicle, the front structure being configured to collapse towards a rear end of the vehicle when a force directed towards the rear end of the vehicle acting on the upper portion of the front structure reaches a threshold force; a rear structure having a lower portion attached to the frame and an upper portion, the rear structure being configured to withstand a force directed towards the rear end of the vehicle acting on the upper portion of the rear structure exceeding the threshold force; and at least one deformable energy absorbing structure arranged between the upper portion of the front structure and the upper portion of the rear structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples. 
       In the drawings: 
         FIG.  1    is a side view of a vehicle according to an embodiment of the present invention, in the form of a truck having a forward compartment and a crash impact absorbing arrangement at least partly arranged in the forward compartment. 
         FIGS.  2 A-B  are different views of the crash impact absorbing arrangement comprised in the vehicle in  FIG.  1   . 
         FIG.  3    is a schematic illustration from the side of a forward collision crash scenario into the rear of a trailer of a truck. 
         FIGS.  4 A-C  schematically illustrate, from a top view, a characteristic behavior of the crash impact absorbing arrangement according to embodiments of the present invention during the forward collision crash scenario shown in  FIG.  3   . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION 
       FIG.  1    schematically shows a vehicle, here in the form of a truck  1 , comprising a cabin  3  and a forward compartment  5  extending from the cabin  3  towards a front end  7  of the truck  1 . The truck  1 , which may be a fully electric truck or at least a truck without an internal combustion engine in the forward compartment  5 , additionally comprises a frame and a crash impact absorbing arrangement. These parts are, however, not visible in  FIG.  1   , but will be described in greater detail below. 
     Referring now to  FIGS.  2 A-B , the truck  1  thus comprises an exemplary crash impact absorbing arrangement  9  and a frame  11 . The crash impact absorbing arrangement  9  comprises a front structure  13  having a lower portion  15  and an upper portion  17 , a rear structure  19  having a lower portion  21  and an upper portion  23 , first  25   a  and second  25   b  deformable energy absorbing structures, and first  27   a  and second  27   b  high-strength material structures, here exemplified by struts. 
     As is schematically shown in  FIGS.  2 A-B , the lower portion  15  of the front structure  13  is attached to the frame  11 , and the upper portion  17  of the front structure  13  is arranged between the cabin  13  and the front end  7  of the truck  1 . The lower portion  21  of the rear structure  19  is attached to the frame  11  and the upper portion  23  of the rear structure  19  is arranged further away from the front end  7  of the truck  1  than the upper portion  17  of the front structure  13 . The first  25   a  and second  25   b  deformable energy absorbing structures are arranged between the upper portion  17  of the front structure  13  and the upper portion  23  of the rear structure  19 , and the first  27   a  and second  27   b  struts are attached to the frame  11  and extend from the frame  11  to the upper portion  23  of the rear structure  19  to provide additional strength to the rear structure  19 . 
     The front structure  13  is configured to collapse towards a rear end of the truck  1  when a force directed towards the rear end of the truck  1  acting on the upper portion  17  of the front structure  13  reaches a predefined threshold force F th . The rear structure  19  is configured to withstand a force directed towards the rear end of the truck  1  acting on the upper portion  23  of the rear structure  19  exceeding the predefined threshold force F th . The energy absorbing structures  25   a - b  are arranged between the upper portion  17  of the front structure  13  and the upper portion  23  of the rear structure  19  for transferring a force directed towards the rear end of the truck  1  acting on the upper portion  17  of the front structure  13  to the upper portion  23  of the rear structure  19 , while being deformed to allow movement of the upper portion  17  of the front structure  13  towards the upper portion  23  of the rear structure  19 , following (and during) collapse of the front structure  13 . 
     This crash impact absorbing arrangement  9  not only absorbs the impact energy of a forward collision in a controlled way, but also prevents pitching of the truck  1  which would change the impact height of the cabin  3  to the upper barrier in the case of a Trailer back vehicle impact test scenario. 
     As will be described in greater detail further below, this crash impact absorbing arrangement  9  can functionally replace the internal combustion engine of a conventional truck in terms of protecting the integrity of the cabin  3  in the event of a forward collision, in particular a forward collision into the back of a trailer. 
     In the example configuration of  FIGS.  2 A-B , the front structure  13  of the crash impact absorbing arrangement  9  is arch-shaped to at least partly surround the front fan (not shown in  FIGS.  2 A-B ) of the cooling system (also not shown) of the truck  1 . Hereby, the crash impact absorbing arrangement  9  provides protection for the cooling system, while efficiently utilizing the space available in the forward compartment  5 . It should, however, be noted that the front structure  13 , the rear structure  19  and the at least one deformable energy absorbing structure  25   a - b  may be realized in many different ways well within the reach of one of ordinary skill in the art, as long as they are dimensioned and configured to collapse in the desired manner in the event of a forward collision. For instance, neither the front structure  13 , nor the rear structure  19  has to be configured as an arch, but could, for example, be provided as one or several front pillars and one or several rear pillars. 
     In  FIGS.  2 A-B , the upper portion  23  of the rear structure  19  is arranged between the cabin  3  and the upper portion  17  of the front structure  13 . It should, however, be noted that although this configuration may be advantageous, it may be feasible to arrange the upper portion  23  of the rear structure  19  further back in the truck  1  depending on the overall configuration of the truck  1 . For instance, the upper portion  23  of the rear structure  19  could be arranged below a portion of the cabin  3 . 
     Furthermore, the struts  27   a - b  in  FIGS.  2 A-B  represent only one exemplary way of achieving the specified properties of the rear structure  19 . As will be clear to one of ordinary skill in the art, there are many other ways of achieving the same properties, such as for example by choice of materials or dimensions of the rear structure  19  and/or by connecting the rear structure  19  and the frame  11  using other well-known force transmitting means. 
       FIG.  3    is a schematic illustration from the side of a forward collision crash scenario into the rear of a trailer of a truck. For illustrative purposes,  FIG.  3    does not show the entire truck  1 , but only the crash impact absorbing arrangement  9  and the frame  11  in relation to the road level  29 . Also shown in  FIG.  3    are a lower crash barrier  31  and an upper crash barrier  33  representing the situation with a forward collision into the back of a trailer. As can be understood from  FIG.  3   , the crash impact absorbing arrangement  9  may advantageously be arranged and configured to absorb the energy of the impact with the upper barrier  33 , to prevent or at least reduce damage to the cabin  3 . Therefore, the upper portion  17  of the front structure  13  may advantageously extend at least as far upwards as 0.5 meter above the road level  29 . Even more advantageously, the upper portion  17  of the front structure  13  may extend at least as far upwards as 1 meter above the road level  29 . The same would be valid for the upper portion  23  of the rear structure  19 . 
     When the truck  1  collides with the upper barrier  33  with sufficient speed, the upper portion  17  of the front structure  13  will be subjected to a force in excess of the above-mentioned threshold force F th . This should result in collapse of the front structure  13 . One convenient way of achieving this desired collapse may be to mount the lower portion  15  of the front structure  13  to the frame  11  using bolts  35  designed to fail at a critical load corresponding to the above-mentioned threshold force F th  acting on the upper portion  17 . As the front structure  13  collapses, the rear structure  19  should remain substantially undeformed throughout the collision event. This may be achieved by one or several design measures. Some such exemplary design measures are schematically indicated in  FIG.  3   . For instance, the lower portion  21  of the rear structure  19  may be welded to the frame  11 , as is indicated in  FIG.  3    by exemplary schematic welding locations  37   a - b . In addition, or as an alternative to the welding, the upper portion  23  of the rear structure  29  may be supported by struts  27   a - b , and/or the rear structure may be made of a durable material, such a high-strength steel. 
     When, during the forward collision, the front structure  13  collapses while the rear structure  19  remains substantially undeformed, the energy of the collision is mainly absorbed by deformation of the deformable energy absorbing structures  25   a - b . This is schematically illustrated in  FIGS.  4 A-C , which are simulations of the state of the crash impact absorbing arrangement  9  at different stages of the collision with the obstacle represented by the lower  31  and upper  33  barriers. 
       FIGS.  4 A-C  schematically illustrate, from a top view, an exemplary characteristic behavior of the crash impact absorbing arrangement  9  according to embodiments of the present invention during the forward collision crash scenario shown in  FIG.  3   . 
     Referring first to  FIG.  4 A , the crash impact absorbing arrangement  9  has not yet impacted with the upper barrier  33  and is thus undeformed. 
     In  FIG.  4 B , the upper portion  17  has been subjected to a force in excess of the above-mentioned threshold force F th , resulting in a collapse of the front structure  13 . The collapse of the front structure  13 , in turn, results in deformation of the energy absorbing structures  25   a - b , as is schematically indicated in  FIG.  4 B . 
     Finally, in  FIG.  4 C , the energy absorbing structures  25   a - b  are fully deformed, while the rear structure  19  remains substantially intact. 
     In the example configuration of the crash impact absorbing arrangement  9  indicated here, the energy absorbing structures  25   a - b  have been provided in the form of tubes with spaced apart recesses to guide the tube to bend sideways when loaded longitudinally. As is well known to those of ordinary skill in the art, there are many other ways to achieve the desired behavior of the energy absorbing structures  25   a - b , such as by using a conventional crash box configuration. 
     It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims. For example, the crash impact absorbing arrangement  9  may comprise one or several additional structures arranged between the front structure  13  and the rear structure  19 .