[0001] The present disclosure, in general, relates to parcel shelf of vehicle
5 and, more particularly, to assembly of parcel shelf with at least two cushion
structures and a rear door to reduce rattling noise and to restrict the movement of
the parcel shelf.
BACKGROUND
[0002] Background description includes information that may be useful in
10 understanding the present invention.
[0003] The parcel shelf is provided on luggage area at rear side of the vehicle
to cover the luggage open space. The parcel shelf is mounted on quarter lower
trim on left hand side and right hand side of the vehicle. The parcel shelf rotates
about a pivot point to provide open and close mechanism to the parcel shelf.
15 Further, the parcel shelf rests on the quarter lower trim resting surface. A cushion
structure is provided on the parcel shelf on the rear side interfacing with back door
trim to restrict movement of the parcel shelf.
[0004] The parcel shelf is made of thermoplastic material and tends to move
inside with application of force from back door while closing the back door. The
20 parcel shelf comprises horizontal surface and vertical surface that bents downward
at a minimum draft angle from the vertical direction at edge facing the back door.
The cushion structure is mounted on the vertical surface and receives the back
door.
[0005] Japanese patent publication JPH08156703A discloses a structure for
25 fixing a parcel shelf that can be reduced in manufacturing cost. In this application,
two cushion structures are provided in middle of the parcel shelf that abut with the
back door trim. Disadvantage associated with the Japanese application is that a
cushion structure is provided at intermediate position causing more thermal
3
deformation due to heat load and permanent deformation due to back door
reaction force.
[0006] Another disadvantage is that rear cushion structure walls are
perpendicular to vertical surface of the parcel shelf but with a single central slug
5 in cushion structure which rocks or moves in vertical direction along the single
central slug that does not provide proper abutting of the cushion structure with the
back door trim so as to reduce the rattling noise.
[0007] Similarly, another Japanese patent publication JP2014159216A
discloses a support structure for a parcel shelf. In this application, a single cushion
10 is put at center causing more thermal deformation due to heat load and permanent
deformation due to back door reaction force.
[0008] Fig. 1 illustrates a conventional assembly 100 of a cushion structure
103 with a parcel shelf 101 and abutting of the cushion structure 103 with a back
door trim 102. As shown in the fig.1, the cushion structure 103 with a single slug
15 105 is mounted on vertical face of the parcel shelf 101 at one end and other end
abut with the back door trim 102 of the back door (not shown in Fig. 1). Upon
abutting, the back door trim 102 applies a force on the cushion structure 103 that
goes in rearward direction as indicated by 105. The cushion structure 103 is
compressed by distance as indicated by 106. However, during vehicle running
20 condition, actuation force 104 is applied to the parcel shelf in vertical direction
but only a vertical component of reaction force from the back door is applied
which is less than the actuation force 104. Hence, the parcel shelf 101 tends to
move in vertical direction which causes rocking motion in cushion structure 103.
As a result, interference between the cushion structure 103 and back door trim 102
25 is disturbed and hence causes rattling.
[0009] Moreover, rattling of parcel shelf is a prevalent problem in passenger
vehicles. Reasons for rattling can be many where some of the reasons are:
4
[0010] (1) Polypropylene present in parcel shelf is a thermoplastic material
which tends to undergo thermal deformation with rise in temperature causing
deviation in interference of rear elastomer cushion and back door trim.
[0011] (2) Forces coming on parcel shelf during back door closing tend to
5 permanently deform parcel shelf with passage of time. This problem escalates
with rise in temperature due to presence of a thermoplastic composite.
[0012] (3) Actuation forces acting on the parcel shelf when vehicle is running
on rough road tends to rotate parcel shelf by creating moment about parcel shelf
hinge (Rattle actuating moment), which is countered by moment coming due to
10 reaction force coming on the parcel shelf from back door trim (Rattle mitigating
moment). In actual road testing, the back door does not remain exactly stationary.
Movement in back door could vary the relation between cushion and back door
trim and hence compressive reaction force from back door trim on parcel shelf.
[0013] (4) Due to variation in part size within the system and in the
15 environment parts, there could be a tolerance range for the rattle actuating and
mitigating moments acting on luggage cover.
[0014] (5) External factors like suspension tuning and tire pressure variations
also cause changes in the actuation forces. Since the compressive reaction force
from the rear cushion is fixed for a given compression, the variation in actuation
20 forces may not be accommodated for all conditions.
[0015] If the [Rattle actuating moment]> [Rattle mitigating moment], the
parcel shelf tends to rattle. The moment imbalance could be the result of any of
the following reasons -
[0016] (A) Rear elastomer cushion is not properly designed to cater to all the
25 above variations/problems.
[0017] The cushions are not mounted at proper location on the parcel shelf to
cater or mitigate the rattling noise.
[0018] The existing cushion structure comprises a mounting protrusion and a
back door receive portion connected with the mounting protrusion. The mounting
5
protrusion, i.e., single slug or leg inserted into a mounting hole provided on
vertical surface of the parcel shelf and the back door receiving portion rocks in
vertical direction about the mounting protrusion with the parcel shelf. Further, the
back door receive portion is provided at an angle with the mounting protrusion by
5 defining a neck portion that stuck with the mounting hole of the parcel shelf. With
this neck portion and angled profile, the back door receiving portion swings or
rocks in vertical direction.
[0019] With repetitive use, the cushion gets permanently deformed and starts
transferring force to the parcel shelf which increases stress in parcel shelf and
10 henceforth reduces its life. Further, the interference between the back door and the
parcel shelf reduces and creates a gap between the parcel shelf and the back door.
At running condition, the parcel shelf vibrates and creates a disturbing rattling
noise inside the vehicle cabin as there is no dampening contact between the back
door and the parcel shelf.
15 [0020] Therefore, there is a need to provide assembly of parcel shelf with the
cushion structure and the back door that can cater generation of rattling noise.
OBJECTS OF THE DISCLOSURE
[0021] Some of the objects of the present disclosure, which at least one
embodiment herein satisfy, are listed hereinbelow.
20 [0022] A main object of the present disclosure is to provide an assembly of
parcel shelf with cushion structure and back door trim to restrict movement of rear
parcel shelf and to reduce rattling noise.
[0023] An object of the present disclosure is to position the cushion structure
in line with quarter lower resting to reduce the volume available for deformation
25 due to thermal forces and moment arm for reaction force coming from back door
during open and close cycles hence reducing permanent deformation.
[0024] An object of the present disclosure is to provide a cushion structure
that gets compressed with application of force by the back door trim but don’t
swing during vehicle running condition.
6
[0025] Another object of the present disclosure is to provide a holding
structure in back door trim to hold the cushion structure during vehicle running
condition.
[0026] These and other objects and advantages of the present invention will
5 be apparent to those skilled in the art after a consideration of the following
detailed description taken in conjunction with the accompanying drawings in
which a preferred form of the present invention is illustrated.
SUMMARY
[0027] This summary is provided to introduce concepts related to an assembly
10 of parcel shelf with cushion structure and back door trim for reducing rattling
noise. The concepts are further described below in the detailed description. This
summary is not intended to identify key features or essential features of the
claimed subject matter, nor is it intended to be used to limit the scope of the
claimed subject matter.
15 [0028] In an embodiment, the present disclosure relates to an assembly of a
rear parcel shelf and a back door of a vehicle. The assembly comprising the parcel
shelf adapted to extend rearward from an upper end portion of a back seat towards
the back door. The parcel shelf is mounted on a quarter lower resting portion of a
side lower quarter trim member provided on left hand side and right hand side of
20 rear end of the vehicle and a pair of cushion structure mounted on the parcel shelf
and mounted to interpose between the parcel shelf and a back door trim. Each of
cushion structure from the pair of cushion structure is mounted in-line with the
quarter lower resting portion of the side trim member at the left hand side and the
right hand side of the parcel shelf. A pair of curved emboss portion is provided on
25 the back door trim corresponding to the pair of the cushion structure.
[0029] In an aspect, width (D) of flat portion of the curved emboss portion is
more than width (d) of the cushion structure.
[0030] In an aspect, the back door trim receiving portion of the cushion
structure is mounted perpendicular to the parcel shelf.
7
[0031] In an aspect, each of the cushion from the pair of cushion structure
comprises two legs parallel to each other.
[0032] In another embodiment of the present subject matter, a cushion
structure is mounted on a parcel shelf. The cushion structure comprising a back
5 door trim receiving portion defining a top surface and a bottom surface, and a
mounting portion extending from the bottom surface of the back door trim
receiving portion. The mounting portion consists of two mounting legs extending
in perpendicular direction from the bottom surface and are parallel to each other.
Further, width (w) of the mounting leg is less than width (W) of the side surface
10 of the back door trim receiving portion. In front view of the cushion structure, a
gap (G) is provided between the two mounting legs.
[0033] In an aspect, the side surface of the back door trim receiving portion
and side surface of the mounting portion are continuous.
[0034] In an aspect, the side surface of the back door trim receiving portion
15 and side surface of the mounting portion are not continuous.
[0035] In an aspect, the cushion structure is made of rubber material.
[0036] Various objects, features, aspects, and advantages of the inventive
subject matter will become more apparent from the following detailed description
of preferred embodiments, along with the accompanying drawing figures in which
20 like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The illustrated embodiments of the subject matter will be best
understood by reference to the drawings, wherein like parts are designated by like
numerals throughout. The following description is intended only by way of
25 example, and simply illustrates certain selected embodiments of devices, systems,
and methods that are consistent with the subject matter as claimed herein,
wherein:
[0038] Fig. 1 illustrates an assembly of parcel shelf with cushion structure and
back door trim as known;
8
[0039] Fig. 2 illustrates top view of an assembly of the parcel shelf with
cushion structure and back door trim, in accordance with an embodiment of the
present disclosure;
[0040] Fig. 3 illustrates another top view of an assembly of the parcel shelf
5 with cushion structure and back door trim, in accordance with an embodiment of
the present disclosure;
[0041] Fig. 4 illustrates cross section view of the assembly of the parcel shelf
with cushion structure and back door trim, in accordance with an embodiment of
the present disclosure;
10 [0042] Fig. 5 illustrates front view of cushion structure of fig. 4; and
[0043] Fig. 6 illustrates perspective view of the cushion structure of fig. 4.
[0044] The figures depict embodiments of the present subject matter for the
purposes of illustration only. A person skilled in the art will easily recognize from
the following description that alternative embodiments of the structures and
15 methods illustrated herein may be employed without departing from the principles
of the disclosure described herein
DETAILED DESCRIPTION
[0045] The detailed description of various exemplary embodiments of the
disclosure is described herein with reference to the accompanying drawings. It
20 should be noted that the embodiments are described herein in such details as to
clearly communicate the disclosure. However, the amount of details provided
herein is not intended to limit the anticipated variations of embodiments; on the
contrary, the intention is to cover all modifications, equivalents, and alternatives
falling within the scope of the present disclosure as defined by the appended
25 claims.
[0046] It is also to be understood that various arrangements may be devised
that, although not explicitly described or shown herein, embody the principles of
the present disclosure. Moreover, all statements herein reciting principles, aspects,
9
and embodiments of the present disclosure, as well as specific examples, are
intended to encompass equivalents thereof.
[0047] The terminology used herein is for the purpose of describing particular
embodiments only and is not intended to be limiting of example embodiments. As
5 used herein, the singular forms “a”, “an” and “the” are intended to include the
plural forms as well, unless the context clearly indicates otherwise. It will be
further understood that the terms “comprises”, “comprising”, “includes” and/or
“including,” when used herein, specify the presence of stated features, integers,
steps, operations, elements and/or components, but do not preclude the presence
10 or addition of one or more other features, integers, steps, operations, elements,
components and/or groups thereof.
[0048] It should also be noted that in some alternative implementations, the
functions/acts noted may occur out of the order noted in the figures. For example,
two figures shown in succession may, in fact, be executed concurrently or may
15 sometimes be executed in the reverse order, depending upon the functionality/acts
involved.
[0049] Unless otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which example embodiments belong. It will be further
20 understood that terms, e.g., those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their meaning in the
context of the relevant art and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0050] Referring to Fig. 2, the present subject matter relates to an assembly
25 200 of a parcel shelf 201 with a cushion structure 204a, 204b (collectively
referred as 204) for restricting movement of parcel shelf and reducing rattling
noise during vehicle running condition. The parcel shelf 201 is adapted to extend
rearward towards the back door mounted on the vehicle body from an upper end
portion of the seat back (not shown in fig.). Further, one end of the parcel shelf
10
201 may be pivotally mounted above the seat back on the vehicle body or
pivotally mounted on the upper portion of the seat back.
[0051] As shown in Fig. 2, the parcel shelf 201 is mounted on a quarter lower
resting portion 203a, 203b of a side lower quarter trim members 202a, 202b that
5 are provided on left hand side and right hand side of rear end of the vehicle,
respectively. Further, a pair of cushion structure 204a, 204b is mounted on the
parcel shelf 201 and provided to interpose between the parcel shelf 201 and a back
door trim 205. The cushion structure 204a, 204b is in interference with back door
trim 205 of the back door to restrict movement of the parcel shelf 201 during
10 vehicle running condition.
[0052] As shown in figs. 2 and 3, each of cushion structure from the pair of
cushion structure 204a, 204b is mounted in-line with the quarter lower resting
portion 203a, 203b of the side lower quarter trim members 202a, 202b provided at
the left hand side and the right hand side of the vehicle rear end. With the
15 positioning of the cushion structure 204a, 204b in-line with the quarter lower
resting portion 203a, 203b, respectively, volume available for deformation on the
parcel shelf 201 due to thermal forces and moment arm for reaction force coming
from the back door during opening and closing cycle is reduced.
[0053] Fig. 3 illustrates volumetric thermal expansion of the parcel shelf 201
20 and impact of moment arm for reaction force coming from the back door. The
volumetric thermal expansion of a material is calculated by equation 1.
γVΔT ………………………… Equation 1
Where γ: Coefficient of volumetric thermal expansion; V: Volume of specimen;
ΔT: Temperature change subjected to specimen.
25 [0054] As shown in the fig. 3, the half of the parcel shelf 201 along line 3 has
highest volume as compared to volume along line 2 and line 1. Therefore, the
relationship between the volumes is V3 >V2 >V1 (Since thickness of parcel shelf
is constant).
11
[0055] Further, the temperature change remains same throughout the parcel
shelf. Accordingly, the volumetric thermal expansion is in relation:
γV3ΔT >γV2ΔT > γV1ΔT
It is clear from the above equation that by shifting cushion structure 204b towards
5 quarter lower resting portion 203b in width direction, thermal deformation
occurring in the parcel shelf 201 can be reduced. Thus, if the cushion structure
204b is placed in-line with the quarter lower resting portion 203b, the effective
volume available for thermal deformation is reduced to zero, hence the volumetric
thermal deformation is negated.
10 [0056] Furthermore, distance between the quarter lower resting portion 203b
(similarly for quarter lower resting portion 203a) and line 1, 2, 3 on the parcel
shelf 201 is in relation x>y>z hence the moment arm for reaction force coming
from the back door trim 205 can also be reduced by shifting rear cushion towards
quarter lower resting surface in width direction thereby reducing the permanent
15 deformation occurring in the parcel shelf 201.
[0057] Referring to fig. 4 illustrating cross section view of assembly of the
parcel shelf 201 with the cushion structure 204a, 204b and the back door trim 205.
The back door trim 205 is provided with a pair of curved emboss portion 301a,
301b. The pair of curved emboss portion 301a, 301b are corresponding to the pair
20 of the cushion structure 204a, 204b. In an embodiment, the shape of each of the
pair of curved emboss portion 301a, 301b is defined to receive the upper surface
of the cushion structure 204a, 204b. The pair of curved emboss portion 301a,
301b holds the cushion structure 204a, 204b to restrict its movement. In another
embodiment, the shape of each of the pair of curved emboss portion 301a, 301b
25 corresponds to shape of the upper surface of the cushion structure 204a, 204b. In
an exemplary structure as shown in the fig. 4, each of the emboss portion defines
tapered edges to facilitate holding of the cushion structure 204a, 204b. The
tapered surface of the cushion structure 204a, 204b is in interference with tapered
edge of the emboss portion 301a, 301b to direct reaction force in downward
12
direction to cater or cancel the impact of actuation force coming from downward
direction towards upward direction on the parcel shelf 201.
[0058] As shown in fig. 4, vertical compression of the cushion structure 204a,
204b by the back door trim 205 is indicated by arrow 302 so that under
5 compressed state reaction force Fc from the back door trim 205 can counter the
actuation force coming from downward direction.
[0059] The present assembly 200 provides vertical compression that increases
efficiency of the cushion structure 204 by reducing required hardness of the
cushion structure hence reduces stress on the parcel shelf 201 and increases
10 longevity of the cushion structure 204 and the parcel shelf 201. If the cushion
structure material is having high hardness value, a direct impact of door closing
force is applied to the parcel shelf 201, hence reducing longevity of the parcel
shelf 201.
[0060] As shown in the fig. 4, width ‘D’ of flat portion of the curved emboss
15 portion 301a, 301b is more than width ‘d’ of the cushion structure 204a, 204b. A
flat gap 303 is provided on the flat portion of the curved emboss portion 301a,
301b for movement of the cushion structure 204a, 204b.
[0061] Referring to figs. 5 and 6 together, the cushion structure 400 (204a,
204b of the fig. 2) is provided that is mounted on a parcel shelf 201. The cushion
20 structure 400 comprises a back door trim receiving portion 401 defining a top
surface 401a and a bottom surface 401b, and a mounting portion 402 which is
extending from the bottom surface 401b of the back door trim receiving portion
401. The mounting portion 402 consists of two mounting legs 402a, 402b
extending away in parallel direction from the bottom surface 401b. The back door
25 trim receiving portion 401 defines the top surface 401a, the bottom surface 401b,
left hand side surface 401c, right hand side surface 401d, front surface 401e, and
rear surface 401f (not shown in figures).
[0062] As shown in fig. 6, width ‘w’ of the mounting leg 402 is less than
width ‘W’ of the side surface 401c, 401d of the back door trim receiving portion
13
401. In front view of the cushion structure 400, a gap ‘G is provided between the
two mounting legs 402a, 402b.
[0063] As shown in fig. 6, side surface of 401c of the back door trim receiving
portion 401 and side surface 402c of the mounting portion 402 is continuous.
5 Similarly, side surface 401d of the back door trim receiving portion 401 and side
surface 402d of the mounting portion 402 is continuous.
[0064] As shown in figs. 4 and 5, the back door trim receiving portion 401 of
the cushion structure 400 (204) is in perpendicular relation with the parcel shelf
201 and there is no angular gap in between the sides of the back door trim
10 receiving portion 401 and the surface of the parcel shelf 201. Accordingly, there is
no rocking movement to the back door trim receiving portion 401 of the cushion
structure 400 during vehicle running condition.
[0065] The cushion structure 400 is made of rubber material, preferably,
Ethylene Propylene Diene Monomer (EPDM).
15 [0066] While the foregoing describes various embodiments of the invention,
other and further embodiments of the invention may be devised without departing
from the basic scope thereof. The scope of the invention is determined by the
claims that follow. The invention is not limited to the described embodiments,
versions or examples, which are included to enable a person having ordinary skill
20 in the art to make and use the invention when combined with information and
knowledge available to the person having ordinary skill in the art.

We claim:

1. An assembly (200) of a parcel shelf (201) and a back door of a vehicle, the
assembly (200) comprising:
5 the parcel shelf (201) adapted to extend rearward from an upper
end portion of a back seat, the parcel shelf (201) is mounted on a quarter
lower resting portion (203a, 203b) of a quarter lower trim members (202a,
202b) provided on left hand side and right hand side of rear end of the
vehicle; and
10 a pair of cushion structure (204a, 204b) mounted on the parcel
shelf (201) and mounted to interpose between the parcel shelf (201) and a
back door trim (205),
characterized in that,
each of cushion structure from the pair of cushion structure
15 (204a, 204b) is mounted in-line with the quarter lower resting
portion (203a, 203b) of the quarter lower trim members (202a,
202b) at the left hand side and the right hand side of the vehicle,
respectively.
2. The assembly (200) as claimed in claim 1, wherein a pair of curved emboss
20 portion (301a, 301b) is provided on the back door trim (205) corresponding
to the pair of the cushion structure (204a, 204b).
3. The assembly (200) as claimed in claim 2, wherein width (D) of flat portion
of the curved emboss portion (301a, 301b) is more than width (d) of the
cushion structure (204a, 204b).
25 4. The assembly (200) as claimed in claim 2, wherein back door trim receiving
portion (401) of the cushion structure (204a, 204b) is mounted
perpendicular to the parcel shelf (201).
5. The assembly (200) as claimed in claim 1, wherein each of the cushion
structure from the pair of cushion structure (204a, 204b) comprises two legs
30 parallel to each other.
15
6. A cushion structure (400) mounted on a parcel shelf (201), the cushion
structure (400) comprising:
a back door trim receiving portion (401) defining a top surface (401a)
and a bottom surface (401b); and
5 a mounting portion (402) extending from the bottom surface (401b) of
the back door trim receiving portion (401), the mounting portion (402)
consists of:
two mounting legs (402a, 402b) extending in parallel direction
from the bottom surface (404b),
10 wherein width (w) of the mounting leg (402) is less than width
(W) of the side surface (401c, 401d) of the back door trim receiving
portion (401),
in front view of the cushion structure (400), a gap (G) is
provided between the two mounting legs (403a, 403b).
15 7. The cushion structure (400) as claimed in claim 6, wherein the side surface
(401c) of the back door trim receiving portion (401) and side surface (402c)
of the mounting portion (402) is continuous.
8. The cushion structure (400) as claimed in claim 6, wherein the side surface
(401d) of the back door trim receiving portion (401) and side surface (402d)
20 of the mounting portion (402) is continuous.
9. The cushion structure (400) as claimed in claim 6, wherein the cushion
structure (400) is made of rubber material.