DESC:FIELD
The present disclosure relates to the field of mechanical engineering, and more particularly, relates to the field of door structures of automobile vehicles.
BACKGROUND
In today’s era, customers are concerned about vehicle acoustics such as Door Closing Acoustics and NVH (noise, vibration and harshness), and also about the durability of door structures as they consist of systems like Glass and Window winding mechanism, Latch, Trim and Electrical Wiring Harness. Conventionally, brackets are added to improve the stiffness of door structure. However, addition of brackets increases the overall weight of the door structure and requires more time for assembly.
Further, conventional door structures of a vehicle are provided with a honeycomb block that is configured to absorb the impact force subjected on the vehicle. Typically, a honeycomb block comprises three sections of honeycomb elements as disclosed in US granted patent number US 6117520. The honeycomb elements are characterized in a way such that the cell size of each honeycomb element section decreases from a large size in one section to a smaller size in the neighboring section and an even smaller size in a third section. Conventionally, the honeycomb block is fabricated from strips of cardboard which are glued together to form the honeycomb cell structure. Since, the honeycomb cell structure disclosed in US granted patent number US 6117520 is made of cardboard, the honeycomb block does not provide stiffness to the doors of the vehicle and therefore is prone to deformation or breaking.
Further, US granted patent number US8091286 discloses that the honeycomb structure is made of a resin and requires additional bolting to keep the honeycomb elements together to improve the fuel economy. However, additional bolting increases the cost and since the honeycomb structure is not integral with the doors of a vehicle, keeping the honeycomb elements together during impact is difficult.
Therefore, there is felt a need to develop a door structure that alleviates the aforementioned drawbacks of conventional door structures.
SUMMARY
The present disclosure envisages a door assembly for a vehicle. The door assembly comprises a door structure and an inner panel defining a body that has a first operative surface and a second operative surface. The inner panel has a plurality of crest portions configured on at least one of the first operative surface and the second operative surface.
In an embodiment, a plurality of trough portions is defined on at least one of the first operative surface and the second operative surface.
In another embodiment, the assembly further includes a first panel affixed to one of the first operative surface and the second operative surface, thereby providing a flat base to the inner panel. The first panel has a plurality of apertures for facilitating mounting of the first panel to the door structure.
In another embodiment, the plurality of crest portions and the plurality of trough portions are configured on the inner panel in a regularly distributed configuration. In still another embodiment, the plurality of crest portions and the plurality of trough portions are configured on the inner panel in an irregularly distributed configuration.
In an embodiment, the plurality of crest portions defines a pebble structure on the inner panel. In another embodiment, the plurality of crest portions defines a beaded structure on the inner panel.
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.
An object of the present disclosure is to provide a door assembly for a vehicle, which improves the stiffness of the doors.
Another object of the present disclosure is to provide a door assembly for a vehicle, which improves the modal frequency of the doors of the vehicle.
Yet another object of the present disclosure is to provide a door assembly for a vehicle, which requires minimal assembly time.
Still another object of the present disclosure is to provide a door assembly for a vehicle, which improves door closing acoustics, point mobility, weight to stiffness ratio, and durability of the doors of the vehicle.
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.
BRIEF DESCRIPTION OF DRAWING
A door assembly for a vehicle, of the present disclosure, will now be described with the help of an accompanying drawing, in which:
Fig.1 illustrates a schematic view of a conventional door assembly for a vehicle;
Fig.2 illustrates a schematic view of a door assembly for a vehicle, in accordance with an exemplary embodiment of the present disclosure;
Fig. 3A illustrates a schematic view of a cross-section of an inner panel used in the door assembly of Fig. 2; and
Fig. 3B illustrates a schematic view of a cross section of an inner panel, in accordance with another embodiment of the present disclosure.
LIST OF NUMERAL REFERENCES
100 Conventional Door Assembly
102 Inner Panel
104 Door Structure
200 Door Assembly
202 Door Structure
204 Inner Panel
204A First operative surface
204B Second operative surface
206 Crest portions
208 Trough portions
210 First panel
212 Apertures
DETAILED DESCRIPTION
In today’s era, customers are concerned about vehicle acoustics such as Door Closing Acoustics and NVH, and also about the durability of door structures as they consist of systems like Glass and Window winding mechanism, Latch, Trim and Electrical Wiring Harness. Conventionally, brackets were added to improve the stiffness of door structures. However, addition of brackets increases the overall weight of the door structure and requires more time for assembly.
Further, conventional door structures of a vehicle are provided with a honeycomb block that is configured to absorb the impact force subjected on the vehicle. Since, the honeycomb cell structure is made of cardboard, the honeycomb block does not provide stiffness to the doors of the vehicle and therefore is prone to deformation or breaking.
Further, the honeycomb structure made of a resin requires additional bolting to keep the honeycomb elements together to improve the fuel economy. Additional bolting increases the cost and since the honeycomb structure is not integral with the doors of a vehicle, keeping the honeycomb elements together during impact is difficult.
Figure 1 illustrates a schematic view of a conventional door assembly 100 for a vehicle. In the conventional door assembly 100, brackets (not shown in the figure) are added to improve the stiffness of the door which results in an increase in the overall weight of the door assembly 100 and requires more time for assembling an inner panel 102 with a door structure 104. The conventional door assembly 100 may further comprise parts such as a glass run channel, an inner waist reinforcement, an outer waist reinforcement, an oil canning beam, an intrusion beam, a latch reinforcement, a hinge reinforcement, and a hinge assembly, which are configured to strengthen the conventional door assembly 100 and make it durable. However, the inner panel 102 is externally attached to the door structure 104 of the conventional door assembly 100, and is not integral to it, therefore, keeping the parts of the conventional door assembly 100 together during heavy impact is difficult. The above mentioned parts of the conventional door assembly 100 are not exclusively labelled in the figure 1.
In order to overcome the aforementioned drawbacks, the present disclosure envisages a door assembly for a vehicle. The door assembly comprises a door structure and an inner panel defining a body that has a first operative surface and a second operative surface. The inner panel has a plurality of crest portions configured on at least one of the first operative surface and the second operative surface. The door assembly, as envisaged in the present disclosure, is provided with the crest portions which provide stiffness to the door assembly, and which eliminate the need to use the external brackets for providing stiffness and rigidity to the door assembly.
In an embodiment, a plurality of trough portions is defined on at least one of the first operative surface and the second operative surface.
In another embodiment, the assembly further includes a first panel affixed to one of the first operative surface and the second operative surface, thereby providing a flat base to the inner panel. The first panel has a plurality of apertures for facilitating mounting of the first panel to the door structure.
In another embodiment, the plurality of crest portions and the plurality of trough portions are configured on the inner panel in a regularly distributed configuration. In still another embodiment, the plurality of crest portions and the plurality of trough portions are configured on the inner panel in an irregularly distributed configuration.
In an embodiment, the plurality of crest portions defines a pebble structure on the inner panel. In another embodiment, the plurality of crest portions defines a beaded structure on the inner panel.
The door assembly of a vehicle, of the present disclosure will now be 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 structure for the doors of a vehicle of the present disclosure has been described with reference to Fig.2.
Fig. 2 illustrates a schematic view of a door assembly 200 for a vehicle, in accordance with an exemplary embodiment of the present disclosure. Fig. 3A illustrates a schematic view of a cross-section of an inner panel used in the door assembly. The door assembly 200 comprises a door structure 202, and an inner panel 204 affixed to the door structure 202. The inner panel 204 defines a body that has a first operative surface 204A and a second operative surface 204B. The inner panel 204 has a plurality of crest portions 206 configured on at least one of the first operative surface 204A and the second operative surface 204B. In an embodiment, the crest portions 206 are configured on the first operative surface 204A. In another embodiment, the crest portions 206 are configured on the second operative surface 204B. In yet another embodiment, the crest portions 206 are configured partially on the first operative surface 204A and partially on the second operative surface 204B.
The inner panel further comprises a plurality of trough portions 208 configured on at least one of the first operative surface 204A and the second operative surface 204B. In an embodiment, the recesses 208 are configured on the first operative surface 204A. In another embodiment, the recesses 208 are configured on the second operative surface 204B. In yet another embodiment, the crest portions 206 are configured partially on the first operative surface 204A and partially on the second operative surface 204B.
In another embodiment, as illustrated in Fig. 3B, the assembly further includes a first panel 210 affixed to one of the first operative surface 204A and the second operative surface 204B, thereby providing a flat base to the inner panel 204. The first panel 210 has a plurality of apertures for facilitating mounting of the first panel 210 to the door structure 202.
In another embodiment, the plurality of crest portions 206 and the plurality of trough portions 208 are configured on the inner panel 204 in a regularly distributed configuration. In still another embodiment, the plurality of crest portions 206 and the plurality of trough portions 208 are configured on the inner panel in an irregularly distributed configuration. In an embodiment, the plurality of crest portions 206 defines a pebble structure on the inner panel 204. In another embodiment, the plurality of crest portions 206 defines a beaded structure on the inner panel 204.
The door assembly 200 further comprises a glass run channel, an inner waist reinforcement, an outer waist reinforcement, an oil canning beam, an intrusion beam, a latch reinforcement, a hinge reinforcement, and a hinge assembly, which are the same as the conventional door assembly and are not exclusively labelled in the figures. In another embodiment, the inner panel has a plurality of cut-outs 212 configured thereon for facilitating assembly of speakers, glass run channel, wiper motor insertion, and hand access.
In another embodiment of the present disclosure, the inner panel is provided with a pebble structure, and is made integral with the outer door panel. The pebble structure of the inner panel 204 improves the modal frequency of the inner panel 204 resulting in an improved stiffness of the inner panel 204. The pebble structure for the inner panel 204 completely eliminates the use of brackets, and therefore simplifies the assembly process and reduces the assembly time.
Some of the advantages of the pebble structure of the inner panel 204 for doors of a vehicle are listed below:
• No external energy absorption material such as resin, cardboard and the like is required, as the pebble structure is an integrated structure with homogeneous material, typically steel;
• Improved noise, vibration and harshness (NVH) performance, since no external brackets are required;
• Improved energy absorption capability at the time of crash since the pebble structure is an integrated structure, thereby improving the durability of the doors of a vehicle; and
• Reduces assembly time and improves structural stiffness.
A modal analysis for analyzing the noise, vibration and harshness test (NVH) parameters a conventional door assembly 100 and the door assembly 200, as disclosed in the present disclosure, were conducted. The modal analysis was performed on modeling software CATIA. The results of the modal analysis are tabulated in table 1.
Table 1
Door assembly Frequency (Hz)
Conventional door assembly 100 12.793
18.334
26.118
35.109
37.863
39.175
44.613
55.036
59.382
67.68
Door assembly 200 22.593
29.639
31.979
39.773
56.37
57.916
64.508
70.89
85.497
89.929

In table 1, the frequency value is the modal frequency at which the deformation of the door assembly takes place when subjected to test vibrations. As can be seen from table 1, the first modal frequency in the conventional door assembly 100 is 12.793 Hz. It is to be noted that the road excitation frequency or the natural frequency of vibrations of the road pavement, due to the passage of vehicles thereon, typically ranges from 10 Hz to 12 Hz, and the first modal frequency of the conventional door assembly is very close to this value. Due to such proximity in the aforementioned frequency values, there are chances of resonance taking place in the conventional door assembly. Resonance results in excessive vibrations of the conventional door assembly, which results in undesired wear of the conventional door assembly.
As can be seen from the Table 1, the first modal frequency for the door assembly 200 is 22.593 Hz. It is observed that the first modal frequency of the door assembly 200 is sufficiently greater than the natural frequency of vibrations of a typical road pavement, which ranges from 10 Hz to 12 Hz. As such, the phenomenon of resonance avoided in the door assembly 200, which translates to a better service life as compared with the conventional door assembly. It can be observed from table 1, that the door assembly 200 exhibits increased modal frequencies as compared to that of the conventional door assembly. The increased modal frequency indicates that the resonance of the door assembly 200 will occur at greater excitation frequencies than that of the conventional door assembly. More specifically, it indicates that the door assembly 200 exhibits increased stiffness as a higher excitation frequency is required to induce resonance in the door assembly 200.
Furthermore, destructive tests were also conducted on the conventional door assembly and the door assembly 200, in accordance with an embodiment of the present disclosure. The destructive tests involved opening and closing the doors for 1 lac cycles. It was observed that the door assembly 200 withstood the completion of the 1 lac cycles without any deformation or crack formations on the door, whereas the conventional door assembly is susceptible to failure of different parts due to the increased number of structural elements such as additional brackets and fasteners.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The structure for the doors of a vehicle, of the present disclosure described herein above has several technical advantages including but not limited to the realization of a structure that:
? improves the stiffness of the doors;
? improves the modal frequency of the doors of the vehicle;
? requires minimal assembly time; and
? improves door closing acoustics, point mobility, weight to stiffness ratio and durability of the doors of the vehicle.
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.
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.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
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.
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.
The foregoing description of the specific embodiments will 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 for 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.
,CLAIMS:We claim:
1. A door assembly (200) for a vehicle, said door assembly (200) comprising:
a door structure (202);
an inner panel (204) defining a body having a first operative surface (204A) and a second operative surface (204B); and
a plurality of crest portions (206) and a plurality of trough portions (208) formed on at least one of said first operative surface (204A) and said second operative surface (204B).
2. The door assembly (200) as claimed in claim 1, which includes a first panel (210) affixed to one of said first operative surface (204A) and said second operative surface (204B), thereby providing a flat base to said inner panel (204).
3. The door assembly (200) as claimed in claim 3, wherein said first panel (210) has a plurality of apertures for facilitating mounting of said first panel to said door structure (202).
4. The door assembly (200) as claimed in claim 1, wherein said plurality of crest portions (206) and said plurality of trough portions (208) are configured on said inner panel (204) in a regularly distributed configuration.
5. The door assembly (200) as claimed in claim 1 or claim 2, wherein said plurality of crest portions (206) and said plurality of trough portions (208) are configured on said inner panel (204) in an irregularly distributed configuration.
6. The door assembly (200) as claimed in claim 1, wherein said plurality of crest portions (206) and said plurality of trough portions (208) define a pebble structure on said inner panel (204).
7. The door assembly (200) as claimed in claim 1, wherein said plurality of crest portions (206) and said plurality of trough portions (208) define a beaded structure on said inner panel (204).