, Description:“Crushable cowl side structure in vehicle to improve frontal offset crash performance”.
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FIELD OF INVENTION
This invention is related to crushable cowl side structure in vehicle to improve frontal offset crash performance. The cowl side structure is provided in a pair in the motor vehicle. 10
BACKGROUND/PRIOR ART
[001] During a frontal crash a vehicle crushes and a gap between A and B pillars is reduced, which results in hindrance to door opening. 15 In order to achieve this requirement of door opening, it is imperative to provide a cow lside structure that absorbs the impact energy. The amount of energy absorbed by cowl side structure during collision determines the amount of gap reduction between A and B pillars i.e. less the energy absorption, more the gap reduction and vice-versa. 20
[002] The cowl side structure includes three cowl side members (1, 2, 3) of sheet metal forming an enclosed part having a closed section as shown in fig. 1. The cowl side structure (C) is placed on both right hand side and left hand side of vehicle in the front inproximity to A- 25
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pillar (A), which is directed towards front bumper of vehicle as illustrated in fig. 1A.The A-pillar (A) maintains required gap (G) from the B-pillar (B). 5
[003] Now reference may be made to fig. 1B indicating construction of each of the three members (1, 2, 3). The first member (1) constitutes top member being at the top, said second member (2) forms side and inner most member, and third member (3) is side and 10 outer most member opposite the second member. The third member (3) faces outside.
[004] The cowl side section is thick at the rear and tapers gradually towards the front as in fig. 1B. The inner cowl side member (2) is 15 welded to suspension strut tower (S) and cowl member (C) as shown in fig. 1C.
[005] The above existing design of the cowl side structure can be divided into three zones (a,b,c) starting from the end in proximity to 20 A-pillar towards front bumper in longitudinal direction thereof as seen in fig.2.
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[006] In case of frontal offset crash, the structure initially deforms at the zone (c) owing to direct interaction with the barrier in the front followed by partial deformation in zone (b) caused by thicker section 5 of cowl side member (2) and this being the location as in fig. 1C of front suspension strut which is usually a sturdy region.
[007] Said partial deformation in zone (b) results in increase in deformation at zone (a) and upward rotation of the cowl side 10 structure, thereby transferring load to A-pillar.
[008] Eventually, the resulted deformation pattern causes higher gap (G, fig. 1A) reduction between A-pillar (A) and B-pillar (B), which in turn causes hindrance to door opening following crash thereby 15 endangering safety of occupants.
[009] Now, some more known technologies in this regard may be discussed hereinbelow:-
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[0010] A vehicle cowl side structure is made of three members to form a closed cross section, wherein each of the members comprises a sheet metal panel with flange along the edge(s) thereof.
[0011] Here, third member is extended to be connected to the front of 25 vehicle and provided with multiple holes for deformation.
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[0012] When the vehicle meets with frontal offset crash the cowl structure undergoes upward rotation and load is transferred to A-5 pillar. As a result, A-pillar is adversely affected, which in turn reduces the gap between A and B-pillar of vehicle.
[0013] According to another disclosure made in known art, a front structure of three members is disposed at an angle, which facilitates 10 bending thereof due to axial load and upward rotation owing to pitching of the vehicle during crash.
[0014] The above provision involves high chances of the load being transferred to the A-pillar as the cowl part may bend during crash, 15 which leads to reduction in A-B pillar gap.
[0015] The reduction in A-B pillar gap endangers safety of occupants in vehicle.
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[0016] In view of the above, it is required to devise a novel and improved cowl side structure to render the same crushable, which in turn improves frontal offset crash performance with minimal AB pillar gap reduction.
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OBJECTS OF THE INVENTION
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[0017] Principal object of the invention is to propose crushable cowl side structure in vehicle to improve frontal offset crash performance which addresses issues of known arts.
[0018] Further object of this invention is to propose crushable cowl 10 side structure in vehicle to improve frontal offset crash performance which avoids transfer of load to A-pillar in the course of frontal offset crash.
[0019] Still further object of this invention is to propose crushable 15 cowl side structure in vehicle to improve frontal offset crash performance which leads to minimum reduction in A-B pillar gap subsequent to frontal offset crash.
SUMMARY OF INVENTION 20
[0020] According to this invention, crushable cowl side structure is provided in vehicle to improve frontal offset crash performance comprising of a plurality of cowl side members secured to each other including outer member, inner member and top member, wherein 25 said outer member is having a gradually reduced section from an intermediate point upto an end thereof directing towards front and each of the inner and outer members is having atleast one slot.
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BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0021] Further objects and advantages of this invention will be more 5 apparent from the ensuing description when read in conjunction with the accompanying drawings of exemplary embodiments of invention and wherein:
Fig. 1 shows: Side view of conventional cowl side structure for a 10 vehicle.
Fig.1A shows: Side view of vehicle mounted with existing cowl side structure.
Fig. 1B shows: Cowl side members of known cowl side structure.
Fig. 1C shows: Connection of cowl side member (s) with adjacent 15 parts of vehicle.
Fig. 2 shows: Deformation pattern of existing cowl side structure.
Fig. 3 shows: Crushable cowl side structure in vehicle to improve frontal offset crash performance according to 20 present invention.
Fig. 4A shows: First cowl side member of invention.
Fig. 4A' shows: Positioning of notch of the first cowl side member in vehicle.
Fig. 4B shows: Second cowl side member of invention. 25
Fig. 4C shows: Third cowl side member of invention.
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Fig. 5 shows: Sectional modification of third cowl side member in accordance with the present invention. 5
Fig. 6 shows: Curtailed section of first and second cowl side member of invention.
Fig. 7 shows: Deformation pattern of cowl side structure of invention.
Fig. 8 shows: Comparison of axial crush length between current 10 and novel cowl side structure.
Fig. 9 shows: Comparison of A-B pillar deformation between existing and new cowl side structure.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE 15 TO THE ACCOMPANYING DRAWINGS:
[0022] The instant invention teaches a technology pertaining to crushable cowl side structure in vehicle to improve frontal offset crash performance. 20
[0023] The following description will describe specifically and precisely only the constructional features of cowl side structure comprising of a closed section of a plurality of cowl side members secured to each other including outer member, inner member and top member, 25 wherein said outer member is having a gradually reduced section from an intermediate point upto an end thereof directing towards front bumper and each of the inner and outer members is having
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atleast one slot without illustrating construction of adjacent parts thereto. 5
[0024] Now, reference may be made to figure 3 reflecting cowl side structure of invention, which constitutes assembly of three cowl side members (1', 2', 3') fixedly secured to each other so as to form a single part of closed section to be mounted in front of the vehicle 10 under bonnet area ahead of A-pillar in both left hand side and right hand side of vehicle. Length of the structure runs parallel to the length of vehicle.
[0025] The cowl side structure of invention has been designed such 15 that it triggers collapse in cowl side members at the required location thereof in order to enhance the A-B pillar gap reduction significantly.
[0026] For first cowl side member (1') forming top member, reference may be made to fig. 4A. The member is an elongated single piece, 20 which includes a panel (P1) with bending on one side directed downward to form a flange (F1) in longitudinal direction thereof. The flange, edge of which is curved including a plurality of curvatures placed at different distance from the panel therealong as shown in the fig. All the four edges of member (1') are curved. 25
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[0027] In addition to the above, there is a notch (V) on the member, 5 wherein the notch is having substantially a V-section, which is directed inward of the member itself as shown.
[0028] The notch is located optimally at an intermediate point of the member to improve the deformation of the cowl side structure. 10 Specifically, the notch is placed at/near to the end of strut member (S1) and at/near to the beginning of cowl member (C) as in fig. 4A' to end deformation thereat. Here, the notch determines the final bending line of the cowl structure during crash.
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[0029] Now referring to fig. 4B for the second cowl side member (2'), which is also a single enlarged piece forming inner member.
[0030] The cowl side member comprises a panel (P2) with a bending on both sides in longitudinal direction so as to provide a flange (F2 and 20 F3) as shown. Further, the member is having a plurality of depressed and protruded parts as clearly seen in the figure for maintaining required clearance from the adjacent parts of vehicle during assembly. All edges of the member are having curvature.
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[0031] In conjunction with the above, there is provision of a slot (2a) at an intermediate location of the member specifically; slot is placed 5 in a panel2 portion under the strut (S1), wherein the slot is having an elongated profile, edges of which can be straight/curved. The size of opening of slot is determined as per need.
[0032] For third cowl side member, reference may be made to fig. 4C. 10 This is also a single longitudinal piece. The third cowl side member (3') is having a panel (P3) with a flange (F4, F5) on both sides in longitudinal direction thereof, wherein all the four edges of the same are curved as shown. For the furtherance of the A-B pillar gap reduction, the following modification is effected in the section of third 15 member constituting outer member as illustrated in fig. 5.
[0033] The length of third member can be divided into three zones (a, b,c) which can be called as rear part (a) directing towards rear, middle part (b) and front part (c) directing towards front of vehicle. 20
[0034] Here, the section of member at rear part (a) is same/ comparable to that of available third member so as to prevent deformation as it is the closest part to the A-pillar.
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[0035] The front suspension strut member (S1) forms a sturdy region, 5 hence it deforms very less during frontal offset crash, which is in proximity to the middle part (b) as in fig. 4A'.
[0036] In order to render the third member deformable, the section at this region (b) is reduced to approximately 50% as compared to rear 10 part. Again front end (c) also needs to deform by absorbing the impact energy, hence the section at front part (c) is provided in continuation with that of middle part (b) as shown. Thus, the third member is having a gradually reduced section along its length from end of rear part to front part. 15
[0037] The third member is also having multitude of slots (3a, 3b, 3c), which will be discussed hereinunder:-
– First slot (3a) comprises an elongated opening with a curvature at 20 both ends for allowing local bending along the longitudinal axis thereof. This is located in the front part (c).
– Second slot (3b) is preferably a broaden opening, both ends of which can be curved/straight. This slot is located just opposite the 25 slot (2a) of the second cowl side member. The slot is provided in the middle part (b).
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– Third slot (3c) also comprises an enlarged opening with straight/curved ends. This is positioned in the thicker zone (a) of the third member for saving material thereof, which leads to cost saving and improvement in fuel efficiency of vehicle.
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[0038] To avoid rusting of the member, it is preferably provided at the bottom of the third member as shown.
[0039] The size of slot (3a, 3b, 3c) may vary according to the requirement. 15
[0040] In order to obtain a closed section of the cowl structure of invention by connecting three cowl side members (1', 2', 3') including modified section of third cowl side member (3'), first and second cowl side members (1', 2') are designed with curtailed section (1A, 2A) as 20 best seen in fig. 6.
[0041] Thus, the present invention saves material owing to reduced section of each of the three cowl side members. This leads to cost saving and improvement in fuel efficiency of vehicle. 25
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[0042] Fig. 4A, 4B and 4C illustrates cowl side member of a particular 5 variant of vehicle adopting inventive concept of the instant invention. Hence, the profile of each of the cowl side members may vary for a different model relying on the same inventive concept of the proposed application which is embodied in the claims.
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[0043] When the vehicle encounters frontal offset crash, the invented cowl structure in question undergoes deformation, wherein the flow of deformation takes place in first member via third and second member i.e. 3'&2'?1'.
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[0044] The slots (2a and 3b) trigger inward collapse of the whole cowl structure along the longitudinal axis of the slots (2a and 3b). The slot (3a) assists in quick local bending without changing the axis of deformation of the cowl structure.
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[0045] In new design of cowl side structure, reduced section and holes (3b, 2a) form a weak zone in zone (b) .During cowl side structure interaction with barrier a bending line is formed along the axis of holes, which triggers the inward deformation of cowl side members (I1, fig. 7) at this location . In Zone (c) hole (3a) enables quick local 25 folding by restraining the cowl side member from changing the axis during interaction with deformable barrier. The deformation in Zone
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(a) is kept to a minimum with the help of bigger section of Cowl side member at this region .The notch (V) in member (1') triggers the final collapse of cowl side structure (I
2) thereby improving the deformation of zone(b) .
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[0046] The cowl side structure can be made of sheet metal and fabricated by stamping, bending, punching and welding without limiting scope of the invention to the same. Thus, other materials and methods readily apparent to a person skilled in the art are understood to be within perview of the invention. 10
Observation
[0047] The crushability of the new cowl side structure improves by 162% (M) as compared to a particular existing cowl structure as 15 shown in fig. 8 indicating a plot between Time (X-axis) and change in axial length (Y-axis) for conventional design (A) and new design (B).
[0048] Further, the reduction in the gap between A and B pillars is lowered approximately by 59% in comparison to a particular 20 currently available cowl side structure, which in turn accomplishes performance improvement of 59% (N) as illustrated in fig. 9 reflecting a diagram between Time (X-axis) and AB-pillar gap (Y-axis) for known design (A) and novel design (B).
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[0049] Further, the cowl side structure is lighter than a specific conventional model by nearly 10%.
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[0050] The furtherance in the performance of the cowl side structure of invention can be briefly summarized in the tabular form as follows:-
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Advantageous Features
[0051] -Improvement in crushability and therefore enhancement in
A-B pillar gap reduction. 10
- Reduction in weight, which in turn results in cost saving and furtherance in fuel efficiency.
- Efficient functioning.
[0052]It is to be noted that the present invention is susceptible to 15 modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

Claims:WE CLAIM:
1. Crushable cowl side structure in vehicle to improve frontal offset crash performance comprising of a plurality of cowl side members secured to each other including outer member, inner member and top member, wherein said outer member is having 5 a gradually reduced section from an intermediate point upto an end thereof directing towards front and each of the inner and outer members is having atleast one slot.
2. Crushable cowl side structure in vehicle to improve frontal 10 offset crash performance as claimed in claim 1 wherein the structure is placed longitudinally in parallel to the length of vehicle.
3. Crushable cowl side structure in vehicle to improve frontal 15 offset crash performance as claimed in claim 1 or 2 wherein the top member is provided with a notch directed inward thereof and placed at/near to the end of strut member and beginning of cowl member, which determines final bending line of the cowl structure during crash. 20
4. Crushable cowl side structure in vehicle to improve frontal offset crash performance as claimed in any of the preceding claims wherein the inner member is having a slot placed in a portion under the strut member, wherein the slot is having an 25 elongated profile, edges of which can be straight/curved.
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5. Crushable cowl side structure in vehicle to improve frontal offset crash performance as claimed in any of the preceding claims wherein the outer member includes rear part, middle part and front part, in which said rear part is located closest to the A-pillar and extended towards the front with gradual 5 reduction in section therefrom.
6. Crushable cowl side structure in vehicle to improve frontal offset crash performance as claimed in claim 5 wherein the middle part and front part is having the reduced section which 10 is approximately 50% with respect to said rear part.
7. Crushable cowl side structure in vehicle to improve frontal offset crash performance as claimed in any of the preceding claims wherein the outer member is provided with multitude of 15 slots, in which first, second and third slot is located in front, middle and rear part respectively.
8. Crushable cowl side structure in vehicle to improve frontal offset crash performance as claimed in any of the preceding 20 claims wherein said first slot comprises an elongated opening with a curvature at both ends for allowing local bending along its longitudinal axis thereof.
9. Crushable cowl side structure in vehicle to improve frontal 25 offset crash performance as claimed in any of the preceding claims wherein the second slot is preferably a broaden opening,
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both ends of which can be curved/straight, in which the slot is located just opposite the slot of the second cowl side member.
10. Crushable cowl side structure in vehicle to improve frontal offset crash performance as claimed in any of the 5 preceding claims wherein the third slot comprises an enlarged opening, both ends of which can be straight/curved.
11. Crushable cowl side structure in vehicle to improve 10 frontal offset crash performance as claimed in any of the preceding claims wherein the top and inner member is having curtailed section.
12. Crushable cowl side structure in vehicle to improve 15 frontal offset crash performance as claimed in any of the preceding claims is associated with the advantageous features such as herein described.