DESC:FIELD
The present disclosure generally relates to automobiles. Particularly, the present disclosure relates to a frame structure for an automobile.
BACKGROUND
A floor included in the frame structure of a conventional four wheeler vehicle includes a centrally disposed tunnel or a concave portion extending longitudinally along the length of the vehicle. The floor supports a seating arrangement which generally includes two rows of seats. Typically, the front row accommodates two persons on two seats with each seat disposed on each side of the tunnel and the second row placed behind the first row includes three seats such that a middle seat is right above the tunnel. Such a tunnel arrangement is essential for providing structural strength to the frame, particularly, to the floor of the vehicle in order to prevent buckling of the frame structure in case of a collision. The tunnel arrangement provides body floor stiffness and creates an additional load path to meet different crash requirements. However, this inherent configuration of the frame structure, having the tunnel arrangement, causes space constraints and only allows seating arrangement for two passengers in the front row. Additionally, as the tunnel is configured on the floor and disposed between the first seat and the second seat, it occupies space between the first seat and the second seat and restrains configuration of a third seat. Further, such tunnel also causes discomfort to a passenger seated on the middle seat of the second row, as the passenger has to keep his/her legs on each side of the tunnel.
There is, therefore, felt a need to limit the aforementioned drawbacks associated with the conventional frame structures.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide a frame structure, for an automobile, that achieves flat floor configuration without compromising the structural strength of frame structure of the automobile.
Still another object of the present disclosure is to provide a frame structure that ensures high structural strength of the frame structure and prevents buckling of the frame structure in case of a collision.
Yet another object of the disclosure is to provide a frame structure ensures substantially optimum utilization of space.
Further, an object of the present disclosure is to provide a frame structure that eliminates reinforcing structural elements while still preventing engine movement towards passenger compartment during off set front collision of an automobile.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a frame structure for an automobile. The frame structure includes a pair of side sills and a plurality of longitudinal members that are disposed operatively between the pair of side sills. These pair of side sills and the plurality of longitudinal members extend into a swan like structure at one operative end of the frame structure. The frame structure also includes a plurality of first cross members disposed operatively between and connected to the plurality of longitudinal members. Further, the frame structure includes a plurality of second cross members disposed operatively between the pair of side sills and the plurality of longitudinal members, and are connected thereto. The frame structure also includes a floor extending from one side sill to other side sill of the pair of side sills.
Additionally, in an embodiment, the floor has a beaded configuration for providing structural strength thereto. Further, the swan like structure defines a crush zone and a transition zone. The crush zone is configured to absorb and dissipate maximum amount of energy in case of a collision. The transition zone extends from the crush zone and is configured for controlled deformation to protect an occupant from dash intrusion and floor deformation due to engine movement towards passenger compartment in case of a collision. Furthermore, the pair of side sills, the plurality of first cross members, the plurality of second cross members, the plurality of longitudinal members, and the floor collectively define an occupant zone that is configured for minimum deformation in order to preserve and protect the occupant in the passenger compartment.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The frame structure, for an automobile, of the present disclosure will now be described with the help of the accompanying drawing, in which:
FIG. 1 illustrates a schematic representation of a conventional frame structure for an automobile, wherein tunnel is configured on a floor of the automobile between a driver seat and a passenger seat;
FIG. 2 illustrates a schematic representation of a frame structure for an automobile in accordance with an embodiment of the present disclosure;
FIG. 3 illustrates an isometric view of the frame structure of FIG. 2 in accordance with one embodiment of the present disclosure;
FIG. 4 illustrates a schematic representation of a load path for the frame structure of FIG. 2, wherein the load is distributed in three zones to facilitate efficient dissipation of impact energy during collision;
FIG. 5 illustrates a top view of the frame structure of FIG. 2;
FIG. 6 illustrates a plurality of longitudinal members of the frame structure of the present disclosure in accordance with one embodiment;
FIG. 7 illustrates a joint of the frame structure of the present disclosure in accordance with one embodiment;
FIG. 8a illustrates schematic representation of simulation results of dash intrusion for conventional frame structure, of FIG. 1, having tunnel arrangement;
FIG. 8b illustrates schematic representation of simulation results of dash intrusion for frame structure, of FIG. 2, where tunnel arrangement is absent;
FIG. 9a illustrates schematic representation of simulation results for rail deformation in case of rails configuring the conventional frame structure, of FIG. 1, having tunnel arrangement;
FIG. 9b illustrates schematic representation of simulation results for rail deformation in case of rails configuring the conventional frame structure, of FIG. 2, where tunnel arrangement is absent;
FIG. 10a illustrates schematic representations of simulation for tire intrusion and rail crush pattern in case of rails configuring the conventional frame structure, of FIG. 1, having tunnel arrangement;
FIG. 10b illustrates schematic representations of simulation for tire intrusion and rail crush pattern in case of rails configuring the frame structure, of FIG. 2, where tunnel arrangement is absent;
FIG. 11 illustrates schematic representation of simulation depicting effect of collision on a flat floor configuration achieved by using the frame structure of the present disclosure in accordance with one embodiment;
FIG. 12a illustrates a front view of a floor of the frame structure of FIG. 2 in accordance with one embodiment;
FIG. 12b illustrates a bottom view of the flat front floor of FIG. 12a;
FIG. 13 illustrates a graphical representation of torsion stiffness distribution curve for the frame structure of the present disclosure in accordance with one embodiment; and
FIG. 14a and FIG. 14b illustrate front and rear view of an automobile respectively.
DETAILED DESCRIPTION
The present disclosure envisages a frame structure for an automobile for achieving a flat floor configuration that in turn facilitates in providing an ergonomic seating arrangement for a first row of seats and second row of seats without compromising the structural strength of frame of the automobile.
FIG. 1 of the accompanying drawing, illustrates a schematic representation of a conventional frame structure 10 for an automobile, wherein a concave portion/ tunnel 10a is configured on a floor of the automobile between a driver seat and a passenger seat. The conventional frame structure 10 includes a concave portion/ tunnel 10a along with additional load path underneath the floor for meeting structural requirements of the automobile. But, due to the concave portion/ tunnel 10a, there is no space available for a third seat between the driver seat and the passenger seat. Therefore, because of such configuration of the frame structure, it is not possible to accommodate a third occupant in the first row of the conventional seating arrangement. Additionally, the occupant of the middle seat in the second row of the seats faces dis-comfort due to the floor arrangement having the concave portion/ tunnel 10a.
To limit the drawbacks of the conventional frame structure, the present disclosure envisages a frame structure with a flat floor configuration. In case of the frame structure of the present disclosure, the tunnel is removed and, section requirement and beading pattern is optimized to enhance body stiffness to meet different collision requirements in the absence of the tunnel.
FIG. 2 of the accompanying drawing illustrates a schematic representation of a frame structure 100 for an automobile in accordance with an embodiment of the present disclosure. The frame structure 100 achieves a flat floor configuration for supporting a three-seater seating arrangement in the front portion of the automobile. As a result of the flat floor configuration, a third seat 14 can be accommodated between a driver seat 12 and a passenger seat 16.
As illustrated in FIG. 2 to FIG. 6 of the accompanying drawing, the tunnel is eliminated for creating a vacant space to accommodate a third seat in the front row. However, various modifications are incorporated in the frame structure 100 in order to maintain the structural strength of the frame structure 100 so that minimum damages are incurred and occupant safety is ensured. The frame structure 100 includes a pair of a pair of side sills 102, a plurality of longitudinal members 104, a plurality of first cross members 106, a plurality of second cross members 108 and a floor F. The plurality of longitudinal members 104 are disposed operatively between the pair of side sills 102 such that the pair of side sills 102 and the plurality of longitudinal members 104 extend into a swan like structure at one operative end thereof. The plurality of first cross members 106 are disposed operatively between and connected to plurality of longitudinal members 104. The plurality of second cross members 108 are disposed operatively between the pair of side sills 102 and the plurality of longitudinal members 104 and connected are thereto. The floor F extends from one side sill to other side sill of the pair of side sills 102.
Load path illustrated in FIG. 4 for the frame structure 100 represents that the load for the frame structure 100 is distributed in three zones, particularly, a crush zone A, a transition zone B and an occupant zone C. The swan like structure formed by the pair of side sills 102 and the plurality of longitudinal members 104 defines the crush zone A and the transition zone B. The occupant zone C is defined collectively by the pair of side sills 102, the plurality of first cross members 106, the plurality of second cross members 108, the plurality of longitudinal members 104, and the floor F. The load distribution, along the crush zone A, the transition zone B and the occupant zone C, facilitates efficient dissipation of impact energy during collision. In case of collision, the crush zone A absorbs and dissipates maximum amount of energy with an optimized crush force for the available crush space. The crush zone A is so configured that the crush zone A manages majority of the impact energy and maximum plastic deformation. The transition zone B extends from the crush zone A and has a ring structure which exhibits controlled deformation. The ring structure protects occupants from dash intrusion and floor deformation due to engine movement towards passenger compartment at the time of offset front collision. The ring structure minimizes the front floor deformation at the transition zone B and movement of engine to the passenger compartment, and acts as a shield to protect occupants from dash intrusion due to engine movement towards the passenger compartment. The occupant zone C has a ladder structure and provides minimum deformation for configuring the safety cage in order to preserve and protect the occupants in the passenger compartment. The ladder structure facilitates absolute utilization of the pair of side sills 102, maintains overall automobile stability and provides optimum crash structure.
Further, the ladder structure and the ring structure improve overall automobile torsion stiffness of the frame structure 100. The ring structure acts as a shield to protect occupants from dash intrusion due to engine movement towards passenger compartment because the structural loop gets closed in transition zone B of engine and passenger compartment. The ladder structure enables absolute utilization of the pair of side sills 102 to keep overall automobile stability in case of frontal offset crash. The ladder structure, with the side sills 102 at the right hand side and the left hand side of the frame structure 100, prevents transfer of impact load on larger panels like floor, dash, etc., and improves the overall structural stability and overall torsion stiffness at the time of collision. Such configuration of the frame structure 100 provides a flat floor configuration and also meets offset frontal crash requirement considering the available engine compartment space in front end structure. The frame structure 100 further protects occupants from dash intrusion and floor deformation due to engine movement towards passenger compartment in the event offset front collision. It also controls the plastic deformation of structural members while still maintaining a sufficient survival space for occupants of the automobile in case of crashes involving reasonable deceleration pulse. Furthermore, the frame structure 100 ensures controlled vehicle deformations and efficient management of the residual crash energy to absorb maximum crash energy so as to achieve optimized automobile structure with minimum weight. Such modification in frame structure for achieving flat floor configuration ensures that all kinetic energy of the automobile is dissipated by the front structure 100 by utilizing the available deformation length efficiently without deforming the passenger compartment.
FIG. 7 of the accompanying drawing illustrates a joint J formed by the longitudinal member 104, the first cross members 106 and the second cross members 108 of the frame structure 100. The joint J results in appropriate energy distribution at bottom of swan neck like structure by torque box wrap around joinery and thereby facilitates better distribution of stresses. Further, the floor F has a beaded configuration in order to enhance structural strength. The frame structure 100 includes beads and structural strengthening members to have minimal/ zero impact on occupants comfort. Such modification in frame structure 100 provides flat floor configuration which in turn accommodates three seats in the front row and enhances body stiffness. Such a frame structure 100 does not interfere with packaging of all underbody components and Heating Ventilation and Air Conditioning (HVAC) packaging in the automobile. With such configuration, the frame structure 100 can withstand impact loads due to collision and safety of the occupants is ensured. The beaded configuration of the floor F eliminates middle tunnel structure on the floor F, thereby accommodating three seats in the front row while still meeting crash requirements, durability and NVH. The beaded configuration is optimized such that the beading patterns do not interfere with packaging interfaces like exhaust system, seat system, and parking brake etc. Such configuration of the frame structure 100 helps in meeting offset frontal crash requirement through the optimal crush space in front end structure of the automobile. After the height of the beaded configuration is determined to meet the flat floor target, the shape and orientation of the beaded configuration is worked out considering a number of iterations and simulations using simulation tools to meet different crash requirements considering parameters including but not limited to floor sag, durability, floor deformation in crash and other parameters.
Further, the beaded configuration is optimized for adjusting floor beading heights so that there is enough space for an occupant’s leg movements. Apart from the beaded configuration, various bending patterns can also be incorporated in the floor F and the frame structure 100 for enhancing structural strength of the frame structure 100. In simulation tests for determining optimized beaded configuration, which enhances structural strength of the frame structure 100, it is observed that beaded configuration in longitudinal direction provides better results. The frame structure 100, along with the beaded configuration, include other modifications like raising level of the floor F level from ground so as to accommodate exhaust system easily without requirement of tunnel. In accordance with an embodiment, the clearance between exhaust system and the floor F is maintained at least 35 mm. Additionally, a smooth curvature is provided at rail extensions, particularly, a swan neck structure i.e. the transition zone B of inclined portion to horizontal portion of rail extension is provided that assists in eliminating rail extension reinforcement.
Further modifications are incorporated in the frame structure 100 to enhance structural strength. These modifications include avoiding floor deformation by making the plurality of first cross member 106 and the second cross members 108 in line with the torque box position. The positioning of the cross members 106 and 108, and the longitudinal members 104 of the frame structure 100 is selected after considering a number of iterations and simulations using simulation tools. The frame structure 100 of the present disclosure incurs minimum damages and ensures occupant safety in case of collisions in absence of the tunnel arrangement of the conventional frame structure.
With the elimination of the tunnel arrangement, there is enough space for accommodating various underbody components like exhaust system, parking brake, fuel and bundy lines etc. Further, with the elimination of the tunnel arrangement, and the additional load path from underneath floor and inside passenger compartment, a weight reduction of about 5kgs is achieved. Further as the tunnel is eliminated, alternative cheaper materials can be used to save cost in forming the flat floor of the automobile instead of expensive materials for configuring conventional floor with tunnel.
FIG. 8a and FIG. 8b, of the accompanying drawing, respectively illustrate schematic representations of simulation results for dash intrusion for conventional frame structure 10 with tunnel arrangement and frame structure 100 without tunnel arrangement. The frame structure 100 of the present disclosure ensures ergonomic comfort for middle passenger of both front and second row of seats arranged within the automobile. The sectional height of the beaded configuration and the cross members 106 and 108 cannot be more considering the limitation of accommodating occupant’s leg access zones. The frame structure 100 considers all these constraints and achieves durability targets of front floor.
FIG. 9a and FIG. 9b, of the accompanying drawing, respectively illustrate schematic representations of simulation results for rail deformation in case of rails R1 configuring conventional frame structure 10 with tunnel arrangement and rails R2 configuring the frame structure 100 without tunnel arrangement. From FIG. 9a and FIG. 9b it is evident that the rail deformation R2’ in case of the frame structure 100 is less as compared to the rail deformation R1’ in case of conventional frame structure 10.
FIG. 10a and FIG. 10b, of the accompanying drawing, respectively illustrate schematic representations of simulation for tire intrusion and rail crush pattern in case of rails configuring the conventional frame structure 10 with tunnel arrangement and frame structure 100 without the tunnel arrangement. From the FIG. 10a and FIG. 10b it is evident that the rail crush pattern P2 in case of the frame structure 100 indicates less damage as compared to the rail crush pattern P1 in case of conventional frame structure 10 with tunnel arrangement.
FIG. 11, of the accompanying drawing, illustrates schematic representation of simulation depicting effect of collision on a flat floor configuration achieved by using the frame structure 100. It is observed that the floor F of the frame structure 100 is perfectly intact without any deformation after collision. FIG. 12a, of the accompanying drawing, illustrates a front view of a floor F of the frame structure 100. FIG. 12b, of the accompanying drawing, illustrates a bottom view of the floor F. With such configuration of the floor F, the frame structure 100 meets structural requirements without requiring additional load path underneath the front floor F.
FIG. 13, of the accompanying drawing, illustrates a graphical representation of torsion stiffness distribution curve for the frame structure 100 of automobile. The front view and rear view of the automobile is illustrated in FIG 14a and FIG 14b respectively. From torsion stiffness distribution curve illustrated in the graph of FIG. 13, it is observed that twisting, i.e., deformations experienced by elements of the frame structure in case of conventional frame structure 10 (represented by curve formed by joining circular pointers) is more than that experienced by elements of the frame structure 100 of the present disclosure (represented by curve formed by joining square pointers) for a particular longitudinal distance of the elements.
In one embodiment, the frame structure 100 has increased structural stiffness such that the stiffness of the front long rail twist is enhanced by 25 percent, the stiffness of sill side inner twist is enhanced by 22 percent and the stiffness of the rear rail twist is enhanced by 70 percent. In another embodiment of the frame structure 100, the steering column displacement is reduced by 45 percent, the dash intrusions are reduced by 55 percent, toe pan intrusions are reduced by 47 percent and foot well intrusions are reduced by 45 percent when compared with the conventional frame structure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
• a frame structure, for an automobile, that achieves flat floor configuration without compromising the structural strength of frame structure of an automobile;
• a frame structure that ensures high structural strength of the frame structure and prevents buckling of the frame structure in case of a collision;
• a frame structure ensures substantially optimum utilization of space; and
• a frame structure that eliminates reinforcing structural elements while still preventing engine movement towards passenger compartment during off set front collision of an automobile.
The disclosure is described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. ,CLAIMS:1. A frame structure for an automobile, said frame structure comprising:
a pair of side sills;
a plurality of longitudinal members disposed operatively between said pair of side sills, wherein said pair of side sills and said plurality of longitudinal members extending into a swan like structure at one operative end thereof;
a plurality of first cross members disposed operatively between and connected to said plurality of longitudinal members;
a plurality of second cross members disposed operatively between said pair of side sills and said plurality of longitudinal members, and connected thereto;
and
a floor extending from one side sill to other side sill of said pair of side sills.

2. The frame structure as claimed in claim 1, wherein said floor has a beaded configuration for providing structural strength thereto.

3. The frame structure as claimed in claim 1 or claim 2, wherein:
said swan like structure defines
a crush zone configured to absorb and dissipate maximum amount of energy in case of a collision, and
a transition zone extending from said crush zone, said transition zone configured for controlled deformation to protect an occupant from dash intrusion and floor deformation due to engine movement towards passenger compartment in case of a collision;
and
said pair of side sills, said plurality of first cross members, said plurality of second cross members, said plurality of longitudinal members, and said floor collectively define an occupant zone that is configured for minimum deformation in order to preserve and protect the occupant in the passenger compartment.