U.S. patent application number 12/670307 was filed with the patent office on 2010-08-05 for seat pad and seat for vehicle.
Invention is credited to Yutaka Hirata, Masanori Okumura, Taisuke Yonezawa.
Application Number | 20100194171 12/670307 |
Document ID | / |
Family ID | 40281400 |
Filed Date | 2010-08-05 |
United States Patent
Application |
20100194171 |
Kind Code |
A1 |
Hirata; Yutaka ; et
al. |
August 5, 2010 |
SEAT PAD AND SEAT FOR VEHICLE
Abstract
Ridge portions 9 are provided to be continuously present in
orthogonally intersecting directions by forming plural recessed
holes 8 in the upper surface of an under-thighs portion 2 and an
under-buttocks portion 3 of a seat pad 1 for a vehicle. The height
of each ridge portion 9, i.e. the depth h of each recessed hole 8,
is preferably in the range of 2 to 40 mm, more preferably in the
range of 5 to 20 mm, the width w of each recessed hole 8 is
preferably in the range of 10 to 30 mm, more preferably in the
range of 20 to 30 mm, and the area of an opening of each recessed
hole 8 is preferably in the range of 50 to 1000 mm.sup.2, more
preferably in the range of 100 to 900 mm.sup.2. Accordingly, the
present invention can provide a seat pad, which is excellent in
soft sensation of touch of a surface thereof, satisfactory in the
properties of supporting an occupant, and can be produced by
integral foam molding.
Inventors: |
Hirata; Yutaka;
(Yokohama-shi, JP) ; Okumura; Masanori;
(Yokohama-shi, JP) ; Yonezawa; Taisuke;
(Yokohama-shi, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W., SUITE 800
WASHINGTON
DC
20037
US
|
Family ID: |
40281400 |
Appl. No.: |
12/670307 |
Filed: |
July 23, 2008 |
PCT Filed: |
July 23, 2008 |
PCT NO: |
PCT/JP2008/063214 |
371 Date: |
March 1, 2010 |
Current U.S.
Class: |
297/452.48 ;
5/655.9 |
Current CPC
Class: |
B60N 2/01508 20130101;
B60N 2/3097 20130101; B60N 2/646 20130101 |
Class at
Publication: |
297/452.48 ;
5/655.9 |
International
Class: |
B60N 2/44 20060101
B60N002/44; A47C 27/14 20060101 A47C027/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2007 |
JP |
2007-190967 |
Dec 14, 2007 |
JP |
2007-323520 |
Jun 13, 2008 |
JP |
2008-155503 |
Claims
1. A seat pad formed of resin foam molding, for use in a vehicle,
comprising: ridge portions having flat top surfaces and provided to
be continuously present in plural directions, the ridge portions
being provided between a number of recessed holes formed at least
in a part of an occupant contact surface area of the seat pad.
2. The seat pad for a vehicle of claim 1, wherein the total of
areas of the top surfaces of the respective ridge portions
constitute 20 to 80% of the total area of the recessed holes and
the ridge portions.
3. The seat pad for a vehicle of claim 2, wherein the total of
areas of the top surfaces of the respective ridge portions
constitute 20 to 50% of the total area of the recessed holes and
the ridge portions.
4. The seat pad for a vehicle of claim 1, wherein the depth of each
recessed hole is in the range of 2 to 40 mm.
5. The seat pad for a vehicle of claim 4, wherein the depth of each
recessed hole is in the range of 5 to 20 mm.
6. The seat pad for a vehicle of claim 1, wherein the area of an
opening of each recessed hole is in the range of 50 to 1000
mm.sup.2 and the width of each ridge portion is in the range of 2
to 10 mm.
7. The seat pad for a vehicle of claim 6, wherein the area of an
opening of each recessed hole is in the range of 100 to 900
mm.sup.2 and the width of each ridge portion is in the range of 2
to 10 mm.
8. The seat pad for a vehicle of claim 1, wherein the recessed
holes and the ridge portions are provided at least in an
under-thighs portion of the seat pad.
9. The seat pad for a vehicle of claim 1, wherein the ridge
portions are provided to be continuously present in two
intersecting directions.
10. The seat pad for a vehicle of claim 9, wherein the ridge
portions are provided to be continuously present in two
orthogonally intersecting directions.
11. The seat pad for a vehicle of claim 10, wherein each recessed
hole has a square shape.
12. The seat pad for a vehicle of claim 1, wherein the ridges are
provided to be continuously present in three directions.
13. The seat pad for a vehicle of claim 12, wherein each recessed
hole has a triangular, polygonal, circular or substantially
ellipsoidal shape.
14. The seat pad for a vehicle of claim 12, wherein each recessed
hole has a hexagonal shape.
15. A seat pad formed by a resin foam molding body, for use in a
vehicle, comprising: plural recessed holes formed at least in a
part of an occupant contact surface area or a part of the rear
surface area opposite to the occupant contact surface of the seat
pad.
16. The seat pad for a vehicle of claim 15, wherein the depth of
each recessed hole is in the range of 2 to 40 mm.
17. The seat pad for a vehicle of claim 15, wherein the area of an
opening of each recessed hole is in the range of 50 to 1000
mm.sup.2.
18. The seat pad for a vehicle of claim 15, wherein each recessed
hole has a triangular, square, polygonal, circular or elongated
hole-like shape.
19. The seat pad for a vehicle of claim 15, wherein portions
between the recessed holes constitute ridge portions.
20. The seat pad for a vehicle of claim 19, wherein the width of
each ridge portion is in the range of 2 to 10 mm.
21. The seat pad for a vehicle of claim 19, wherein the ridge
portions are provided to be continuously present in two
intersecting directions.
22. The seat pad for a vehicle of claim 19, wherein the ridge
portions are provided to be continuously present in three
directions.
23. The seat pad for a vehicle of claim 22, wherein each recessed
hole has a hexagonal shape.
24. The seat pad for a vehicle of claim 19, wherein a volume rate
of the ridge portions in a region where the recessed holes and the
ridge portions are provided is in the range of 10 to 80%.
25. The seat pad for a vehicle of claim 24, wherein the volume rate
of the ridge portions is in the range of 40 to 60%.
26. The seat pad for a vehicle of claim 19, wherein the ridge
portions have flat top surfaces.
27. The seat pad for a vehicle of claim 19, wherein at least one of
a corner edge where the top surface and a side surface of each
ridge portion intersects each other and a corner edge where a side
surface of each ridge portion and the bottom surface of an adjacent
recessed hole intersects each other has a curved surface.
28. The seat pad for a vehicle of claim 19, wherein a sectional
area of an opening of each recessed hole remains substantially
unchanged from an entrance portion to the deepest bottom portion
thereof.
29. The seat pad for a vehicle of claim 19, wherein a sectional
area of an opening on the deeper side of the each recessed hole is
smaller than a sectional area of the opening on the entrance side
of the recessed hole.
30. The seat pad for a vehicle of claim 19, wherein the seat pad is
formed of polyurethane foam having density of 20 to 100
kg/cm.sup.3, 25% ILD hardness of 5 to 45 kgf/200 mm.phi..
31. The seat pad for a vehicle of claim 30, wherein the seat pad is
formed of polyurethane foam having density of 35 to 100
kg/cm.sup.3, 25% ILD hardness of 15 to 45 kgf/200 mm.phi..
32. The seat pad for a vehicle of claim 15, wherein the recessed
holes are formed at least in a part of an occupant contact surface
area.
33. The seat pad for a vehicle of claim 32, wherein the seat pad is
a seat cushion pad, in which a corner edge region where a sitting
surface and a front surface thereof intersect each other lacks the
recess holes.
34. The seat pad for a vehicle of claim 33, wherein the corner edge
region is a region having a radius of curvature of 100 mm or
less.
35. The seat pad for a vehicle of claim 32, wherein the recessed
holes are provided at least in an under-thighs portion of the seat
pad.
36. The seat pad for a vehicle of claim 35, wherein the recessed
holes are formed such that a portion under the right thigh, of the
under-thighs portion, is softer than other portions of the
under-thighs portion.
37. The seat pad for a vehicle of claim 32, wherein the recessed
holes are formed only in a portion under the right thigh, of the
seat pad.
38. The seat pad for a vehicle of claim 32, wherein the recessed
holes are formed in a front surface which is to face the lower
parts of legs of an occupant.
39. The seat pad for a vehicle of claim 15, wherein the recessed
portions are formed at least in a part of the rear surface area
opposite to the occupant contact surface.
40. The seat pad for a vehicle of claim 39, wherein the recessed
holes are formed at least in a bottom surface below the
under-thighs portion.
41. The seat pad for a vehicle of claim 40, wherein the recessed
holes are formed such that a portion under the right thigh, of the
under-thighs portion, is softer than other portions of the
under-thighs portion.
42. The seat pad for a vehicle of claim 39, wherein the recessed
holes are formed only in the bottom portion below the portion under
the right thigh, of the seat pad.
43. A seat for a vehicle, having a cushion pad and a back pad
constituted of the seat pad of claim 32, characterized in that
recessed holes in the back pad is deeper than recessed holes in the
cushion pad.
44. The seat pad for a vehicle of claim 43, wherein the recessed
holes are formed at least in an under-thighs portion of the cushion
pad and a back contact portion of the back pad.
45. A seat for a vehicle, having a cushion pad and a back pad
constituted of the seat pad of claim 39, characterized in that
recessed holes in the back pad is deeper than recessed holes in the
cushion pad.
46. A seat for a vehicle of claim 45, wherein the recessed holes
are formed at least in a bottom surface below an under-thighs
portion of the cushion pad and a rear surface behind a back contact
portion of the back pad.
Description
TECHNICAL FIELD
[0001] The present invention relates to a seat pad for a vehicle
and a seat for a vehicle and, in particular, to a seat pad for a
vehicle and a seat for a vehicle each having a passenger contact
surface made to have soft sensation of touch or good sensation of
the pad making a stroke movement.
PRIOR ART
[0002] A seat pad mounted to a vehicle seat or the like is
conventionally manufactured by pouring an urethane blend raw liquid
prepared by blending a polyol component blend liquid and an
isocyante component, into a mold, and then foam molding the
urethane blend raw liquid.
[0003] In a seat pad for a vehicle, an under-thighs portion and an
under-buttocks portion, which are brought into direct contact with
buttocks, back or the like of an occupant, receives a large portion
of the weight of an occupant and thus a material of these portions
closely affects sitting comfort and riding comfort.
[0004] In view of this, there have been proposed various types of
seat cushion pads for a vehicle, in which modifications are made
including increasing density of a sitting surface which most
affects sitting comfort, while decreasing density of other portions
thereof.
[0005] For example, JP 2002-153357 discloses a seat cushion pad for
a vehicle, in which at least a part of the portions other than an
under-buttocks portions of a sitting surface is structured to have
lower density than and substantially equal hardness to the
under-buttocks portion. However, effecting foam molding by using
materials of different types is costly.
[0006] Further, there has conventionally been used a seat pad for a
vehicle, in which a slab urethane foam is pasted on a pad main body
(e.g. JP 9-271423). However, pasting a slab on a pad main body is
costly.
[0007] JP 11-348629 discloses improving soft sensation of touch, of
a surface of an under-buttocks portion of a seat pad made of
polyurethane foam, by providing the surface with slits having 5 mm
depth in the longitudinal and widthwise directions with 50 mm
intervals therebetween.
[0008] However, JP 11-348629 judges, as shown in FIGS. 3 and 4
thereof, that the pad surface thereof is soft by pressing a load
applying means having 50 mm diameter against the pad surface and
measuring the hardness thereof. When buttocks and/or thighs of an
occupant are in contact with the pad surface, the aforementioned
slits of the pad surface hardly contribute to the occupant's
feeling soft sensation of touch and thus improvement of soft
sensation of touch is not satisfactory.
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0009] An object of the present invention is to enable integrally
producing a seat pad for a vehicle by foam molding, which seat pad
is excellent in soft sensation of touch or sensation of the pad
making a stroke movement and exhibits satisfactory supporting
properties of an occupant. Another object of the present invention
is to provide a seat for a vehicle having such a seat pad for a
vehicle as described above.
Means for Solving the Problems
[0010] In a first aspect of the present invention, a seat pad
formed by a resin foam molding body, for use in a vehicle,
comprises ridge portions having flat top surfaces and provided to
be continuously present in plural directions, the ridge portions
being provided between a number of recessed holes formed at least
in a part of an occupant contact surface area of the seat pad.
[0011] In a second aspect of the present invention, the seat pad
for a vehicle as recited in the first aspect is characterized in
that the total of areas of the top surfaces of the respective ridge
portions thereof constitute 20 to 80% of the total area of the
recessed holes and the ridge portions.
[0012] In a third aspect of the present invention, the seat pad for
a vehicle as recited in the second aspect is characterized in that
the total of areas of the top surfaces of the respective ridges
portions thereof constitute 20 to 80% of the total area of the
recessed holes and the ridge portions.
[0013] In a fourth aspect of the present invention, the seat pad
for a vehicle as recited in any of the first to third aspects is
characterized in that the depth of each recessed hole is in the
range of 2 to 40 mm.
[0014] In a fifth aspect of the present invention, the seat pad for
a vehicle as recited in the fourth aspect is characterized in that
the depth of each recessed hole is in the range of 5 to 20 mm.
[0015] In a sixth aspect of the present invention, the seat pad for
a vehicle as recited in any of the first to fifth aspects is
characterized in that the area of an opening of each recessed hole
is in the range of 50 to 1000 mm.sup.2 and the width of each ridge
portion is in the range of 2 to 10 mm.
[0016] In a seventh aspect of the present invention, the seat pad
for a vehicle as recited in the sixth aspect is characterized in
that the area of an opening of each recessed hole is in the range
of 100 to 900 mm.sup.2 and the width of each ridge portion is in
the range of 2 to 10 mm.
[0017] In an eighth aspect of the present invention, the seat pad
for a vehicle as recited in any of the first to seventh aspects is
characterized in that the recessed holes and the ridge portions are
provided at least in an under-thighs portion of the seat pad.
[0018] In a ninth aspect of the present invention, the seat pad for
a vehicle as recited in any of the first to eighth aspects is
characterized in that the ridge portions are provided to be
continuously present in two intersecting directions.
[0019] In a tenth aspect of the present invention, the seat pad for
a vehicle as recited in the ninth aspect is characterized in that
the ridge portions are provided to be continuously present in two
orthogonally intersecting directions.
[0020] In an eleventh aspect of the present invention, the seat pad
for a vehicle as recited in the tenth aspect is characterized in
that each recessed hole has a square shape.
[0021] In a twelfth aspect of the present invention, the seat pad
for a vehicle as recited in any of the first to eighth aspects is
characterized in that the ridges are provided to be continuously
present in three directions.
[0022] In a thirteenth aspect of the present invention, the seat
pad for a vehicle as recited in the twelfth aspect is characterized
in that each recessed hole has a triangular, polygonal, circular or
substantially ellipsoidal shape.
[0023] In a fourteenth aspect of the present invention, the seat
pad for a vehicle as recited in the twelfth aspect is characterized
in that each recessed hole has a hexagonal shape.
[0024] In a fifteenth aspect of the present invention, a seat pad
formed by a resin foam molding body, for use in a vehicle,
comprises plural recessed holes formed at least in a part of an
occupant contact surface area or a part of the rear surface area
opposite to the occupant contact surface of the seat pad.
[0025] In a sixteenth aspect of the present invention, the seat pad
for a vehicle as recited in the fifteenth aspect is characterized
in that the depth of each recessed hole is in the range of 2 to 40
mm.
[0026] In a seventh aspect of the present invention, the seat pad
for a vehicle as recited in the fifteenth or sixteenth aspect is
characterized in that the area of an opening of each recessed hole
is in the range of 50 to 1000 mm.sup.2.
[0027] In an eighteenth aspect of the present invention, the seat
pad for a vehicle as recited in any of the fifteenth to seventeenth
aspects is characterized in that each recessed hole has a
triangular, square, polygonal, circular or elongated hole-like
shape.
[0028] In a nineteenth aspect of the present invention, the seat
pad for a vehicle as recited in any of the fifteenth to eighteenth
aspects is characterized in that portions between the recessed
holes constitute ridge portions.
[0029] In a twentieth aspect of the present invention, the seat pad
for a vehicle as recited in the nineteenth aspect is characterized
in that the width of each ridge portion is in the range of 2 to 10
mm.
[0030] In a twenty-first aspect of the present invention, the seat
pad for a vehicle as recited in the nineteenth or twentieth aspect
is characterized in that the ridge portions are provided to be
continuously present in two intersecting directions.
[0031] In a twenty-second aspect of the present invention, the seat
pad for a vehicle as recited in the nineteenth or twentieth aspect
is characterized in that the ridge portions are provided to be
continuously present in three directions.
[0032] In a twenty-third aspect of the present invention, the seat
pad for a vehicle as recited in the twenty-second aspect is
characterized in that each recessed hole has a hexagonal shape.
[0033] In a twenty-fourth aspect of the present invention, the seat
pad for a vehicle as recited in any of the nineteenth to
twenty-third aspects is characterized in that a volume rate of the
ridge portions in a region where the recessed holes and the ridge
portions are provided is in the range of 10 to 80%.
[0034] In a twenty-fifth aspect of the present invention, the seat
pad for a vehicle as recited in twenty-fourth aspect is
characterized in that the volume rate of the ridge portions is in
the range of 40 to 60%.
[0035] In a twenty-sixth aspect of the present invention, the seat
pad for a vehicle as recited in any of the nineteenth to
twenty-fifth aspects is characterized in that the ridge portions
have flat top surfaces.
[0036] In a twenty-seventh aspect of the present invention, the
seat pad for a vehicle as recited in any of the nineteenth to
twenty-sixth aspects is characterized in that at least one of a
corner edge where the top surface and a side surface of each ridge
portion intersects each other and a corner edge where a side
surface of each ridge portion and the bottom surface of an adjacent
recessed hole intersects each other has a curved surface.
[0037] In a twenty-eighth aspect of the present invention, the seat
pad for a vehicle as recited in any of the nineteenth to
twenty-sixth aspects is characterized in that a sectional area of
an opening of each recessed hole remains substantially unchanged
from an entrance portion to the deepest bottom portion thereof.
[0038] In a twenty-ninth aspect of the present invention, the seat
pad for a vehicle as recited in any of the nineteenth to
twenty-seventh aspects is characterized in that a sectional area of
an opening on the deeper side of the each recessed hole is smaller
than a sectional area of the opening on the entrance side of the
recessed hole.
[0039] In a thirtieth aspect of the present invention, the seat pad
for a vehicle as recited in any of the first to twenty-ninth
aspects is characterized in that the seat pad is formed of
polyurethane foam having density of 20 to 100 kg/cm.sup.3, 25% ILD
hardness of 5 to 45 kgf/200 mm.phi..
[0040] In a thirty-first aspect of the present invention, the seat
pad for a vehicle as recited in the thirtieth aspect is
characterized in that the seat pad is formed of polyurethane foam
having density of 35 to 100 kg/cm.sup.3, 25% ILD hardness of 15 to
45 kgf/200 mm.phi..
[0041] In a thirty-second aspect of the present invention, the seat
pad for a vehicle as recited in any of the fifteenth to
thirty-first aspects is characterized in that the recessed holes
are formed at least in a part of an occupant contact surface
area.
[0042] In a thirty-third aspect of the present invention, the seat
pad for a vehicle as recited in the thirty-second aspect is
characterized in that the seat pad is a seat cushion pad, in which
a corner edge region where a sitting surface and a front surface
thereof intersect each other lacks the recess holes.
[0043] In a thirty-fourth aspect of the present invention, the seat
pad for a vehicle as recited in the thirty-third aspect is
characterized in that the corner edge region is a region having a
radius of curvature of 100 mm or less.
[0044] In a thirty-fifth aspect of the present invention, the seat
pad for a vehicle as recited in any of the thirty-second to
thirty-fourth aspects is characterized in that the recessed holes
are provided at least in an under-thighs portion of the seat
pad.
[0045] In a thirty-sixth aspect of the present invention, the seat
pad for a vehicle as recited in the thirty-five aspect is
characterized in that the recessed holes are formed such that a
portion under the right thigh, of the under-thighs portion, is
softer than other portions of the under-thighs portion.
[0046] In a thirty-seventh aspect of the present invention, the
seat pad for a vehicle as recited in any of the thirty-second to
thirty-fourth aspects is characterized in that the recessed holes
are formed only in a portion under the right thigh, of the seat
pad.
[0047] In a thirty-eighth aspect of the present invention, the seat
pad for a vehicle as recited in any of the thirty-second to
thirty-seventh aspects is characterized in that the recessed holes
are formed in a front surface which is to face the lower parts of
legs of an occupant.
[0048] In a thirty-ninth aspect of the present invention, the seat
pad for a vehicle as recited in any of the fifteenth to
thirty-first aspects is characterized in that the recessed portions
are formed at least in a part of the rear surface area opposite to
the occupant contact surface.
[0049] In a fortieth aspect of the present invention, the seat pad
for a vehicle as recited in the thirty-ninth aspect is
characterized in that the recessed holes are formed at least in a
bottom surface below the under-thighs portion.
[0050] In a forty-first aspect of the present invention, the seat
pad for a vehicle as recited in the fortieth aspect is
characterized in that the recessed holes are formed such that a
portion under the right thigh, of the under-thighs portion, is
softer than other portions of the under-thighs portion.
[0051] In a forty-second aspect of the present invention, the seat
pad for a vehicle as recited in the thirty-ninth aspect is
characterized in that the recessed holes are formed only in the
bottom portion below the portion under the right thigh, of the seat
pad.
[0052] In a forty-third aspect of the present invention, a seat for
a vehicle, having a cushion pad and a back pad constituted of the
seat pad as recited in the thirty-second to thirty-fourth aspects,
is characterized in that recessed holes in the back pad is deeper
than recessed holes in the cushion pad.
[0053] In a forty-fourth aspect of the present invention, the seat
for a vehicle as recited in the forty-third aspect is characterized
in that the recessed holes are formed at least in an under-thighs
portion of the cushion pad and a back contact portion of the back
pad.
[0054] In a forty-fifth aspect of the present invention, a seat for
a vehicle, having a cushion pad and a back pad constituted of the
seat pad as recited in the thirty-ninth aspect, is characterized in
that recessed holes in the back pad is deeper than recessed holes
in the cushion pad.
[0055] In a forty-sixth aspect of the present invention, the seat
for a vehicle as recited in the forty-fifth aspect is characterized
in that the recessed holes are formed at least in a bottom surface
below an under-thighs portion of the cushion pad and a rear surface
behind a back contact portion of the back pad.
EFFECT OF THE INVENTION
[0056] In the seat pad for a vehicle as recited in a first
embodiment of the present invention, a number of recessed holes are
formed at least in a part of an occupant contact surface area of
the seat pad, whereby the ridge portions are provided between the
recessed holes so as to be continuously present in plural
directions. As a result of provision of the ridge portions, soft
sensation of touch, of the occupant contact surface, improves
because the ridge portions are compression-deformed when an
occupant is in contact with the occupant contact surface, as
compared with the case where the recessed holes are not provided.
In a state where the ridge portions are compression-deformed beyond
the predetermined degree, repellent force of the ridge portions
increases and an occupant is firmly supported.
[0057] In the seat pad for a vehicle of the present invention, not
independent projections but the ridge portions are provided so as
to be continuously present in plural directions. Since the ridge
portions do not suffer from buckling even when the ridge portions
are significantly compression-deformed due to the weight of an
occupant, good sitting comfort can be obtained.
[0058] Sitting comfort improves by setting the depth of each
recessed hole in the range of 2 to 40 mm, more preferably in the
range of 5 to 20 mm.
[0059] Good sitting comfort can be obtained by setting the area of
an opening of each recessed hole in the range of 50 to 1000
mm.sup.2, more preferably in the range of 100 to 900 mm.sup.2, and
the width of each ridge portion in the range of 2 to 10 mm.
[0060] Soft sensation of touch, of the occupant contact surface,
can be obtained in a satisfactory manner by setting the total of
areas of the top surfaces of the respective ridge portions to
constitute 20 to 80%, more preferably 20 to 50%, of the total area
of the recessed holes and the ridge portions.
[0061] The configurations of cavity surfaces of a mold can be made
simple and an occupant is less likely to feel poor sitting comfort
due to a wrong extending direction of the ridge portions, by
providing the ridge portions in two intersecting directions, in
particular, in two orthogonal directions.
[0062] The ridge portions can be provided to be continuously
present or extend in two orthogonal directions in a lattice-like
manner by shaping each recessed hole to be square.
[0063] The ridge portions may be continuously present in more than
two directions. In this case, the shape of each recessed hole may
be any of triangular, polygonal, circular, substantially circular
and the like.
[0064] The ridge portions can be provided to continuously and
linearly extend in intersecting three directions by shaping each
recessed hole to be hexagonal and arranging the respective recessed
holes in a honeycomb-like structure, so that an occupant is less
likely to feel poor sitting comfort due to a wrong extending
direction of the ridge portions. Further, foaming raw liquid is
facilitated to enter the portions to form the ridge portions, in a
cavity surface of a mold, by forming the ridge portions to be
continuously present in three intersecting directions in
honeycomb-like structure, whereby there is obtained an effect of
enhancing the yield of molding.
[0065] The seat pad of the first embodiment of the invention may be
either a seat cushion pad or seat back pad.
[0066] In the seat pad for a vehicle as recited in a second
embodiment of the present invention, plural recessed holes are
formed at least in a part of an occupant contact surface area or a
part of the rear surface area opposite to the occupant contact
surface of the seat pad. As a result, soft sensation of touch or
sensation of the pad making a stroke movement improves because the
portions between the recessed holes are compression-deformed when
an occupant is in contact with the aforementioned areas where the
recessed holes are formed. Soft sensation of touch especially
improves by forming the recessed holes in the occupant contact
surface. In a case where when plural recessed holes are formed at
least in a part of the occupant contact surface and a part of the
rear surface opposite to the occupant contact surface, satisfactory
sensation of the pad making a stroke movement can be obtained when
an occupant sits on or leans against the occupant contact surface
because the portions between the recessed holes are
compression-deformed and make a stroke movement in a manner that
the pad recedes backwards. Sensation of the pad making a stroke
movement under an occupant's thighs increases by forming the
recessed holes in the rear surface below the under-thigh portions
of the seat pad.
[0067] The seat pad of the second embodiment of the invention may
be either a seat cushion pad or seat back pad.
[0068] Sitting comfort improves by setting the depth of each
recessed hole in the range of 2 to 40 mm.
[0069] Satisfactory sitting comfort can be obtained by setting the
area of an opening of each recessed hole in the range of 50 to 1000
mm.sup.2.
[0070] In the seat pad for a vehicle of the present invention, it
is preferable to structure portions between the recessed holes not
as independent projections but as the ridges continuously present
in plural directions. It is particularly preferable that the ridge
portions are continuously present in two or three directions. These
ridge portions do not suffer from buckling when they are deeply
compression-deformed by the weight of an occupant and thus achieve
satisfactory sitting comfort. Further, an occupant is less likely
to feel poor sitting comfort due to a wrong extending direction of
the ridge portions, by providing the ridge portions to be
continuously present in two or three directions.
[0071] Further, in a case where the ridge portions are provided to
be continuously present in three intersecting directions as
described above, foaming raw liquid is facilitated to enter the
portions to form the ridge portions, in a cavity surface of a mold,
and an effect of enhancing the yield of molding can be obtained, as
well.
[0072] Good sitting comfort is obtained by setting the width of
each ridge portion in the range of 2 to 10 mm.
[0073] Odd sensation of touch felt by an occupant when the occupant
touches the ridge portions is reduced and thus satisfactory
sensation of touch is obtained by making top surfaces of each ridge
portion flat.
[0074] The shape of each recessed portion may be any of triangle,
square, polygon, circle, elongated hole-like shape (e.g. rectangle,
oval, elongated groove) and the like.
[0075] Satisfactory soft sensation of touch is obtained by setting
a volume rate of the ridge portions in a region where the recessed
holes and the ridge portions are provided in the range of 10 to
80%. Further, not only satisfactory soft sensation of touch but
also satisfactory durability of the ridge portions can be obtained
by setting the volume rate of the ridge portions in the range of 40
to 60%.
[0076] In a case where the sectional area of an opening of each
recessed hole remains substantially unchanged from an entrance
portion to the deepest bottom portion thereof, the widths of the
ridge portions between the recessed portions remain substantially
unchanged from the base end to the tip end, whereby the gradient of
a stress-strain curve during compression deformation is relatively
gentle and satisfactory sitting comfort is obtained.
[0077] In the present invention, durability of the ridge portions
or the protruding portions is enhanced by providing a corner edge
of each ridge portion or each protruding portion with a curved
face.
[0078] Soft sensation of touch, of the under-thigh portions of the
seat pad, improves by forming the recessed holes in the under-thigh
portions or the bottom surface of the seat pad below the
under-thigh portions.
[0079] In an embodiment of the seat pad for the driver's seat in a
vehicle of the present invention, a portion under the right thigh,
of the under-thighs portion, is made softer than other portions of
the under-thighs portion by forming the recessed holes in the
portion under the right thigh, of the under-thighs portion or the
bottom surface of the seat pad therebelow. In this embodiment,
satisfactory soft sensation of touch is obtained when the occupant,
i.e. the driver, presses his/her right thigh upon the seat. The
properties of supporting the driver's body are also satisfactory
because the portions of the seat pad other than the portion under
the right thigh, of the under-thighs portion, are harder than the
portion under the right thigh.
[0080] The entire part of the under-thighs portion may be made
softer than the under-buttocks portion. In this case, the portion
under the right thigh, of the under-thighs portion, may be made
particularly soft. Soft sensation of touch, of the portion under
the left thigh, of the under-thighs portion, is also improved in
such a structure.
[0081] In an embodiment of the seat pad of the present invention,
the surface layer portion of the front surface of the cushion pad
is made soft by providing the front surface with protruding
portions and recessed portions. These protruding and recessed
portions are easily compression-deformed when the lower leg
portions, e.g. calves, of an occupant are in contact therewith,
whereby the occupant feels soft sensation of touch therewith.
[0082] In another embodiment of the seat pad of the present
invention, no protruding and recessed portions are provided in a
corner edge portion between the sitting surface and the front
surface. As a result, protrusions and recesses are not reflected on
a cover material in an engraved manner when the cover material is
attached to the corner edge. Regarding the sitting surface and the
front surface other than the corner edge, protrusions and recesses
do not appear therein on the cover material in an engraved manner,
if protrusions and recesses exist, because the sitting surface and
the front surface are substantially planar.
[0083] In an embodiment of the seat pad for a vehicle of the
present invention, plural recessed holes are formed at least in a
part of the occupant contact surface area or a part of the surface
area opposite to the occupant contact surface of a cushion pad and
a back pad such that the recessed holes in the back pad are deeper
than the recessed holes in the cushion pad. Improved soft sensation
of touch or sensation of the pad making a stroke movement, of the
occupant contact surface, can be obtained because the portions
between the recessed holes are compression-deformed when an
occupant is in contact with these areas. Further, satisfactory soft
sensation of touch or sensation of the pad making a stroke
movement, of the back pad, can be obtained because the recessed
holes in the back pad are deeper than the recessed holes in the
cushion pad.
[0084] Soft sensation of touch or sensation of the pad making a
stroke movement, of the under-thighs portion and the back contact
portion, improves by forming the recessed holes either in the
under-thighs portion and the back contact portion of the seat pad
or the bottom surface of the cushion pad below the under-thighs
portion and the rear surface of the back pad behind the back
contact portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] FIG. 1 is a plan view of a seat pad for a vehicle according
to an embodiment of the present invention.
[0086] FIG. 2 is an enlarged perspective view of a sitting
surface.
[0087] FIG. 3 is a sectional view cut along the line III-III of
FIG. 2.
[0088] FIG. 4 is a sectional view showing another configuration of
a recessed hole and a ridge portion.
[0089] FIG. 5 is a plan view of a part of a bottom surface showing
yet another configuration of the recessed and a ridge portion.
[0090] FIG. 6 is a plan view of a part of a bottom surface showing
yet another configuration of the recessed and the ridge
portion.
[0091] FIG. 7 is a plan view of a seat pad according to another
embodiment of the present invention.
[0092] FIG. 8 is a plan view of a seat pad according to yet another
embodiment of the present invention.
[0093] FIG. 9 is a plan view of a seat pad for a vehicle according
to another embodiment of the present invention.
[0094] FIG. 10 is a sectional view cut along the line X-X of FIG.
9.
[0095] FIG. 11 is a sectional view of a seat pad blank of FIG.
9.
[0096] FIG. 12 is a sectional view of a mold for molding the seat
pad of FIG. 9.
[0097] FIG. 13 is a plan view of a seat pad for a vehicle according
to yet another embodiment of the present invention.
[0098] FIG. 14 is a sectional view cut along the line XIV-XIV of
FIG. 13.
[0099] FIG. 15 is a sectional view of a seat pad blank of FIG.
13.
[0100] FIG. 16 is a sectional view of a mold for molding the seat
pad of FIG. 13.
[0101] FIG. 17 is a plan view of a seat cushion pad for a vehicle
according to an embodiment of the present invention.
[0102] FIG. 18 is an enlarged perspective view of a bottom surface
of the cushion pad.
[0103] FIG. 19 is a sectional view cut along the line XIX-XIX of
FIG. 18.
[0104] FIG. 20 is a front view of a back pad according to an
embodiment of the present invention.
[0105] FIG. 21 is a front view of a back pad for a vehicle of an
embodiment of the present invention.
[0106] FIG. 22 is a graph showing the results of Example and
Comparative Examples.
[0107] FIG. 23 is a graph showing the results of Examples and
Comparative Example.
[0108] FIG. 24 is a graph showing the results of Examples and
Comparative Example.
[0109] FIG. 25 is a graph showing the results of Examples and
Comparative Example.
[0110] FIG. 26 is a graph showing the results of Examples and
Comparative Examples.
BEST MODE FOR IMPLEMENTING THE INVENTION
[0111] An embodiment of the present invention will be described
hereinafter with reference to the drawings. In the drawings, the
reference numbers 1, 1A, 1B, 1C, 1D and 21 represent a seat pad for
a vehicle, 2 represents an under-thighs portion, 3 represents an
under-buttocks portion, 7 represents a portion under the right
thigh, 8, 10 and 12 represent recessed holes, 9, 9A, 11 and 13
represent ridge portions, 23 represents a pelvis contact portion,
and 40 and 50 represent a back pad, of the seat pad.
[0112] [Seat Pad for a Vehicle, of which Under-Thighs Portion is
Made Soft by Recessed Holes]
[0113] FIG. 1 is a plan view of a seat pad for a vehicle according
to an embodiment of the present invention. FIG. 2 is an enlarged
perspective view of a sitting surface. FIG. 3 is a sectional view
cut along the line III-III of FIG. 2.
[0114] The seat pad 1 for a vehicle is formed by polyurethane foam,
which is integrally foam molded as a whole. The seat pad 1 includes
the under-thighs portion 2, the under-buttocks portion 3 and side
portions 4.
[0115] In the upper surface of the seat pad 1 for a vehicle,
longitudinal fitting grooves 5 and a lateral fitting groove 6 for
fitting a cover material (not shown) are formed such that these
grooves form a H-like configuration. A portion situated forward of
the fitting groove 6 and between the fitting grooves 5 constitutes
the under-thighs portion 2, and a portion situated back of the
fitting groove 6 and between the fitting grooves 5 constitutes the
under-buttocks portion 3.
[0116] In the upper surface of the under-thighs portion 2 of the
seat pad 1 for a vehicle, plural (in the drawings, a number of)
recessed holes 8 are formed so that the ridge portions 9 are
provided to be continuously present in the orthogonally
intersecting directions. In the present embodiment, a section
orthogonal to the sitting surface of each ridge portion 9 has a
rectangular shape and the sectional area of an opening of each
recessed hole 8 (the sectional area in the direction orthogonal to
the depth direction of the recessed hole 8) is unchanged from the
entrance portion to the deep bottom portion of the recessed hole.
Accordingly, the width t of a section of the ridge portion 9 is
constant from the base end (the lower end) to the tip end (the
upper end). The ridge portion 9 may have a trapezoidal sectional
shape in which the width t decreases toward the tip end. The
plan-view configuration of each recessed hole 8 is square in the
drawings but may be rectangular.
[0117] In the present embodiment, the ridge portions 9 are
continuously provided in the front-rear direction and the
left-right direction of the seat pad 1 for a vehicle. However, the
ridge portions 9 may be continuously provided in the directions
inclined by 45.degree. with respect to the front-rear direction. In
this case, the shape of the opening of each recessed hole 8 is
preferably a square so that the shape of the opening is
line-symmetrical. The top surface of each ridge portion 9 is flat,
and continuous and flush with the sitting surface surrounding the
region where the recessed holes 8 and the ridge portions 9 are
provided.
[0118] The height of each ridge portion 9, i.e. the depth h of each
recessed hole 8, is preferably in the range of 2 to 40 mm, more
preferably in the range of 5 to 20 mm, and particularly preferably
in the range of 10 to 15 mm. The width (thickness) t of each ridge
portion 9 is preferably in the range of 2 to 20 mm, more preferably
in the range of 4 to 10 mm. The width w of each recessed hole 8 is
preferably in the range of 10 to 30 mm, more preferably in the
range of 20 to 30 mm. The area of the opening of each recessed hole
8 is preferably in the range 50 to 1000 mm.sup.2, more preferably
in the range of 100 to 900 mm.sup.2, and particularly preferably in
the range of 400 to 700 mm.sup.2. In a case where the width
(thickness) t of each recessed hole 9 changes, for example, in the
height direction thereof as shown in FIG. 4, the width (thickness)
t of the ridge portion 9, the width w of the recessed hole 8, and
the opening area of the recessed hole 8 represent the thickness,
the width and the opening area at the middle position in the height
direction, respectively.
[0119] The total of areas of the top surfaces of the respective
ridge portions 9 is preferably in the range of 20 to 80%, more
preferably in the range of 20 to 50%, and particularly preferably
in the range of 25 to 35%, of the total areas of the recessed holes
8 and the ridge portions 9.
[0120] The volume rate of the ridge portions 9 is preferably in the
range of 10 to 80%, more preferably in the range of 25 to 70%, and
particularly preferably in the range of 40 to 60%, wherein a volume
rate of the ridge portions represents a ratio of the volume of the
ridge portions 9 with respect to the volume abh obtained by
multiplying the area of the region where the ridge portions 9 and
the recessed holes 8 are provided (a.times.b in FIG. 2) with the
depth h of the recessed hole 8. Satisfactory soft sensation of
touch, of the portion under the right thigh of the seat pad, is
obtained by setting the volume rate in the range of 10 to 80%.
Further, not only satisfactory soft sensation of touch, of the
portion under the right thigh, but also satisfactory durability of
the ridge portions can be obtained by setting the volume rate in
the range of 40 to 60%.
[0121] The seat pad 1 for a vehicle is integrally molded as a whole
by using polyurethane foam having density preferably in the range
of 20 to 100 kg/m.sup.3, more preferably in the range of 35 to 100
kg/m.sup.3, and particularly preferably in the range of 60 to 70
kg/m.sup.3, and 25% ILD hardness preferably in the range of 5 to 45
kgf/200 mm.phi., more preferably in the range of 15 to 45 kgf/200
mm.phi., and particularly preferably in the range of 15 to 35
kgf/200 mm.phi.. The recessed holes 8 are formed by providing a
cavity surface, preferably the bottom surface of the cavity, of a
mold with a protruding portion.
[0122] A cover material (not shown) is then attached to cover the
polyurethane molding, whereby a seat pad for a vehicle, as a
product, is obtained.
[0123] When an occupant sits on the sitting surface of the seat pad
1 for a vehicle structured as described above, only the ridge
portions 9 are compression-deformed at the initial stage in which
the lower part of the occupant's body is brought into contact with
the sitting surface, so that the occupant feels soft sensation of
touch. Then, as the occupant's body further sinks and the ridge
portions 9 are further compression-deformed, the repellent force of
the ridge portions 9 increases strong enough to stably support the
occupant's body.
[0124] In the present embodiment, the ridge portions 9 are reliably
prevented from being buckled when an occupant sits thereon because
the ridge portions are continuously provided in two orthogonal
directions in a lattice-like structure.
[0125] In a case where the width w of each recessed hole 8 and the
height h and the width t of each ridge portion 9 are set in the
aforementioned ranges, an occupant hardly feels presence of the
recessed holes 8 and the ridge portions 9 when he/she sits thereon,
whereby good sensation of touch is obtained. Further, sensation of
touch is further improved because the top surface of each ridge
portion 9 is flat. Yet further, the gradient of a stress-strain
curve during compression deformation is gentle because the width t
of a section of each ridge portion 9 is unchanged from the base end
to the tip end, whereby satisfactory sitting comfort is
obtained.
[0126] Although the recessed holes 8 and the ridge portions 9 are
provided in the under-thighs portion 2 in the present embodiment,
the recessed holes 8 and the ridge portions 9 may be provided in
both the under-thighs portion 2 and the under-buttocks portion 3 or
only one of the under-thighs portion 2 and the under-buttocks
portion 3.
[0127] [Description of Recess Holes Having Other
Configurations]
[0128] Although the sectional area of an opening of each recessed
hole 8 in the depth direction thereof is constant, a section of
each ridge portion 9 orthogonal to the sitting surface is
rectangular and the width t of each ridge portion 9 is constant
from the base (lower) end to the tip (upper) end in the present
embodiment shown in FIGS. 1 to 3, the present invention is not
limited thereto. For example, each recessed hole 8 may have a
trapezoidal, semicircular, semi-oval or a U-like sectional shape so
that an sectional area of the opening of each recessed hole 8
decreases from the entrance side toward the deep bottom side
thereof and the width t of each ridge portion decreases toward the
tip end thereof. Further, a corner edge on the base end side or the
upper end side of each ridge portion may be provided with a curved
surface, as in the ridge portion 9A shown in FIG. 4. Durability of
the ridge portion improves by being provided with such a curved
surface as described above. The radius of curvature of the curved
surface is preferably in the range of 1 to 20 mm, more preferably
in the range of 1 to 10 mm. The corner edge on the base end side
represents a corner portion connecting a side face of the ridge
portion 9A and a bottom surface of an adjacent recessed hole 8, and
the corner edge on the tip end side represents a corner edge where
a side face of the ridge portion 9A intersects the top surface of
the ridge portion 9A. The radius of curvature of the curved surface
may be approximately a half of the depth h of the recessed hole.
With such a structure as described above, side surfaces of each
ridge portion are constituted of only curved surfaces and
durability of the ridge portion is further improved.
[0129] The plan view configuration of each recessed hole 8 is a
square in FIGS. 1 to 3 to make the with t of each ridge portion 9
constant in the longitudinal direction thereof. However, a plan
view configuration of each recessed hole may have an elongated
shape such as a rectangle, an oval, an elongated groove-like shape,
or a polygonal shape such as a triangle or a hexagon, or a circular
shape.
[0130] In FIG. 5, the recessed holes 10 each having an equilateral
hexagonal shape are arranged in a honeycomb structure so that
portions between the recessed holes 10 constitute the ridge
portions 11.
[0131] The width (thickness) t of each ridge portion 11 is
preferably in the range of 2 to 20 mm, more preferably in the range
of 4 to 10 mm, and the length of the diagonal line of each recessed
hole 10 is preferably in the range of 10 to 40 mm, more preferably
in the range of 15 to 30 mm. The preferable ranges of the opening
area of each recessed hole 10, the height of each ridge portion 11
(the depth of each recessed hole 10) and the portion of the areas
of top surfaces of the ridge portions 11, the preferable range of
the volume rate of the ridge portions, the preferable material for
the seat pad, and the like are similar to those described in the
embodiment of FIGS. 1 to 3.
[0132] Although each recessed hole has an equilateral hexagonal
shape in FIG. 5, the recessed hole may have a hexagonal shape other
than an equilateral hexagon. However, a hexagon where opposite
sides are parallel to each other are preferable and an equilateral
hexagon is the most preferable.
[0133] In FIG. 6, circular recessed holes 12 are arranged such that
the centers of the respective circles are situated at the
respective apexes of equilateral triangles and the portions between
the recessed holes 12 constitute the ridge portions 13.
[0134] The diameter of each recessed hole 12 is preferably in the
range of 10 to 40 mm, more preferably in the range of 15 to 30 mm.
The thickness of the narrowest portion of the ridge portions 13
between the adjacent recessed holes 12 is preferably in the range
of 2 to 20 mm, more preferably in the range of 4 to 10 mm. The
preferable ranges of the opening area of each recessed hole 12, the
height of each ridge portion 13 (the depth of each recessed hole
12) and the portion of the areas of top surfaces of the ridge
portions 13, the preferable range of the volume rate of the ridge
portions 13, the preferable material for the seat pad, and the like
are similar to those described in the embodiment of FIGS. 1 to
3.
[0135] In a case where the ridge portions are continuously provided
in three directions as shown in FIGS. 5 and 6, poor sitting comfort
due to a wrong extending direction of the ridge portions is
alleviated, as compared with a case where the ridge portions are
continuously provided in two directions.
[0136] The seat pad for a vehicle, having the recessed holes and
the ridge portions as shown in FIGS. 5 and 6, are molded by using a
mold having a cavity surface, especially such a mold in which the
bottom surface of a cavity is provided with projecting portions and
recessed grooves of the shapes corresponding to the recessed holes
and the ridge portions.
[0137] In a case where the ridge portions are provided continuously
in three directions as shown in FIGS. 5 and 6, urethane raw liquid
supplied to a portion of the bottom surface of a cavity flows
between the aforementioned protruding portions and is easily
distributed to every corner of the cavity. Specifically, in a case
where the ridge portions are provided continuously in three
directions as shown in FIGS. 5 and 6, urethane raw liquid flows
through the recessed grooves for forming the ridge portions 11, 13
provided at the cavity surface (the bottom surface) of the mold,
with meandering by approximately 60.degree. with respect to the
longitudinal direction, whereby urethane raw liquid easily flows
between the projecting portions. In contrast, in the case shown in
FIGS. 1 to 3 where urethane raw liquid flows with meandering by
90.degree. with respect to the longitudinal direction, urethane raw
liquid flows less easily than the case where urethane raw liquid
meanders by 60.degree. with respect to the longitudinal
direction.
[0138] [Seat Bad for Vehicle, in which Portions Other than Pelvis
Contact Portion, of the Sitting Surface, are Made Soft by Recessed
Holes]
[0139] In the seat pad 21 of FIG. 7, the pelvis contact portion 23
is made flat to firmly support the pelvis, while other portions of
the sitting surface 22 are made soft by the aforementioned
protruding and recessed portions provided therein. Although each
pelvis contact portion 23 is a circular region having a diameter of
approximately 20 to 100 mm in FIG. 7, the pelvis contact region may
be a square, polygonal, oval region or the like having
substantially the same area as the circular region.
[0140] [Seat Pad for Vehicle, in which a Portion Under the Right
Thigh Thereof is Made Soft by Recessed Holes]
[0141] FIG. 8 is a plan view of a seat pad for the driver's seat in
a vehicle according to an embodiment in which a portion under the
right thigh of the seat pad is made soft by recessed holes.
[0142] In this seat pad 1A, the top surface of a portion under the
right thigh 7 in the under-thighs portion 2 is provided with plural
recessed holes and ridge portions. The portion under the right
thigh 7 represents a region of the seat pad which an occupant's
right thigh is in contact with when the occupant sits on the
driver's seat. The side 7a on the left, of the under-right thigh
portion 7, is normally distanced rightward from the center line C
of the seat pad 1A by preferably 10 to 50 mm, more preferably 30 to
40 mm. The side 7b on the right, of the under-right thigh portion
7, is normally distanced rightward from the center line C of the
seat pad 1A by preferably 100 to 200 mm, more preferably 120 to 150
mm. The width of the under-right thigh portion 7 in the left-right
direction, i.e. the distance between the left side 7a and the right
side 7b, is preferably in the range of 50 to 200 mm, more
preferably in the range of 80 to 120 mm. The length L of the
under-right thigh portion 7 in the front-rear direction is
preferably in the range of 100 to 300 mm, more preferably in the
range of 150 to 250 mm. The front end of the under-right thigh
portion 7 is preferably located within 50 mm, more preferably
within 5 to 30 mm, from the frontmost end 1f of the seat pad
1A.
[0143] In the present embodiment, the shapes, dimensions and the
like of the recessed holes and the ridge portions may be any of
those described above.
[0144] When an occupant sits on the seat pad 1A for the driver's
seat structured as described above and the right thigh of the
occupant is pressed against the under-right thigh portion 7, only
the ridge portions are initially compression-deformed and the
occupant feels soft sensation of touch. Accordingly, the sensation
of touch, of the seat pad, felt by the right thigh when the brake
or the axle is operated by the right foot is soft and satisfactory.
As the right thigh sinks deeply and the ridge portions are further
compression-deformed, the repellent force of the ridge portions
increases strong enough to stably support the right thigh.
[0145] Although only the under-right thigh portion 7 is made soft
in the present embodiment, it is acceptable that the under-thighs
portion 2 as a whole is made softer than the under-buttocks portion
3 and the under-right thigh portion 7 is made further softer than
the other portions of the under-thighs portion 2. The entire
under-thighs portion 2 can be made soft by providing the recessed
holes in the entire part of the under-thighs portion 2. The
under-right thigh portion 7 can be made softer than the other
portions of the under-thighs portion by increasing the depths of
the recess holes and/or reducing the widths of the ridge
portions.
[0146] [Seat Pad for Vehicle, in which the Front Portion Thereof is
Made Soft by Recessed Holes]
[0147] FIG. 9 is a plan view of a seat pad for a vehicle, in which
the front portion of the seat pad is made soft by recessed holes
provided therein. FIG. 10 is a sectional view cut along the line
X-X of FIG. 9. FIG. 11 is a sectional view of a blank of the seat
pad for a vehicle of FIG. 9. FIG. 12 is a sectional view of a mold
for molding the seat pad of FIG. 9.
[0148] In the present embodiment, the front surface of the seat pad
1B is provided with plural recessed holes 8 and the ridge portions,
so that the front surface of the seat pad 1B is easily
compression-deformed. Accordingly, soft sensation of touch is
obtained when the lower parts of legs of the occupant are in
contact with the front surface. The front surface of the seat pad
represents a vertical surface of which tangent line is inclined at
least 50.degree., in particular, at least 70.degree. with respect
to the horizontal plane. The width in the left-right direction of a
region where the recessed holes 8 are formed in the front surface
is preferably in the range of 100 to 400 mm, more preferably in the
range of 300 to 350 mm, and the width in the vertical direction of
the region is preferably in the range of 30 to 100 mm, more
preferably in the range of 50 to 70 mm.
[0149] In the present embodiment, the shapes, dimensions and the
like of the recessed holes and the ridge portions may be any of
those described above.
[0150] The seat pad 1B is manufactured by producing a blank thereof
as shown in FIG. 11B by using a mold 30 shown in FIG. 12 and then
bending the front portion of the seat pad blank downward as
indicated by the arrow A.
[0151] The mold 30 includes an upper mold 31 and the lower mold 32.
The bottom surface of a cavity of the lower mold 31 is provided
with protruding portions 33 for forming the recessed holes 8. The
recessed holes 8 of the seat pad blank are not hooked by the
protruding portions 33 and can be smoothly released from the mold,
thereby being prevented from damages, because the protruding
portions 33 are provided to simply protrude upward from the bottom
surface of the cavity. The protruding portions 33 may be mounted to
the lower mold 31 in a detachable manner. The seat pad blank inside
the mold 30 is positioned upside down, as compared with the seat
pad as a finished product.
[0152] [Seat Pad for Vehicle, in which the Front and Sitting
Surfaces are Provided with Recessed Holes, while a Corner Edge
where these Surfaces Intersect Each Other Lacks Recessed Holes]
[0153] FIG. 13 is a plan view of a seat pad for a vehicle, in which
the front and sitting surfaces of the seat pad are provided with
recessed holes, while a corner edge where these surfaces intersect
each other lacks recessed holes. FIG. 14 is a sectional view cut
along the line XIV-XIV of FIG. 13. FIG. 15 is a sectional view of a
blank of the seat pad for a vehicle of FIG. 13. FIG. 16 is a
sectional view of a mold for molding the seat pad of FIG. 13.
[0154] In the present embodiment, the under-thighs portion 2 and
the front surface 1f (the dotted regions in FIG. 13) of the seat
pad 1C are provided with plural recessed holes 8, so that the
under-thighs portion 2 and the front surface 1f are easily
compression-deformed. Accordingly, soft sensation of touch is
obtained when an occupant sits on the seat and his/her thighs are
pressed against the under-thighs portion 2 and/or his/her lower
legs hit the front surface 1f.
[0155] In the present embodiment, the recessed holes 8 are not
formed in a corner edge 1g where the sitting surface and the front
surface intersect each other. Accordingly, recessed holes are not
reflected on a cover material in an engraved manner when the pad is
covered with the cover material.
[0156] In a case where the corner edge portion 1g has a radius of
curvature of not larger than 100 mm, in particular, not larger than
80 mm, e.g. 40 to 60 mm, and thus is strongly curved, it is
prevented that recessed holes are reflected on the cover material
in an engraved manner by not forming the recessed holes 8 in the
corner edge region.
[0157] The front surface 1f of the seat pad corresponds to the
vertical surface lower than the corner edge portion 1g and
represents a region similar to the front surface in the embodiment
of FIG. 9.
[0158] In the present embodiment, the shapes, dimensions and the
like of the recessed holes and the ridge portions may be any of
those described above.
[0159] The seat pad 1C is manufactured by producing a blank thereof
as shown in FIG. 15 by using a mold 30A shown in FIG. 16 and then
bending the front portion of the seat pad blank downward as
indicated by the arrow A.
[0160] The mold 30A includes an upper mold 31 and the lower mold 32
as in the mold 30. The bottom surface of a cavity of the lower mold
31 is provided with projecting portions 33 for forming the recessed
holes 8.
[0161] [Seat Pad for Vehicle, in which Satisfactory Sensation of
the Pad Making a Stroke Movement is Obtained by Forming Recessed
Holes in the Rear Surface of the Seat Pad]
[0162] In another embodiment of the seat pad for a vehicle of the
present invention, plural recessed holes are formed at least in a
part of the rear surface of the resin foam molding body, i.e. the
rear surface opposite to the occupant contact surface. Satisfactory
sensation of the pad making a stroke movement is obtained because
the portions between the recessed holes are compression-deformed
and the pad makes a stroke movement backward when an occupant sits
on and leans against the occupant contact surface. For example,
sensation of the pad making a stroke movement felt by the portions
under thighs improves by forming the recessed holes in the rear
surface below the under-thighs portion.
[0163] FIG. 17 is a plan view showing an example of a seat pad for
a vehicle, having recessed holes in the rear surface of the
occupant contact surface of the seat pad. FIG. 18 is an enlarged
perspective view, from the down side, of the rear surface (the
bottom surface of the pad) below the under-thighs portion of the
seat pad. FIG. 19 is a sectional view cut along the line XIX-XIX of
FIG. 18.
[0164] The seat pad 1D for a vehicle is a cushion pad formed of
polyurethane foam, which is as a whole integrally foam molded. The
seat pad 1D includes an under-thighs portion 2, an under-buttocks
portion 3 and side portions 4 as in the foregoing embodiments.
[0165] In the upper surface of the seat pad 1D for a vehicle,
longitudinal fitting grooves 5 and a lateral fitting groove 6 for
fitting a cover material (not shown) are formed such that these
grooves form a H-like configuration.
[0166] Plural recessed holes 8 are formed in the rear surface, i.e.
the bottom surface of the seat pad 1D, below the under-thighs
portion 2 so that the portions between the recessed holes 8
constitute the ridge portions 9. Provided that the entire length in
the front-rear direction of the seat pad 1D is L.sub.1, the
distance between the front edge of a region where the recessed
holes 8 and the ridge portions 9 are provided and the front end of
the seat pad (the front end of the seat pad 1D in a plan view) is
L.sub.2, and the distance between the front edge and the rear edge
of the region is L.sub.3, L.sub.1 is normally in the range of 550
to 650 mm, L.sub.2 is preferably in the range of 5 to 100 mm, more
preferably in the range of 10 to 50 mm, and L.sub.3 is preferably
in the range of 200 to 350 mm, more preferably in the range of 250
to 300 mm.
[0167] In the present embodiment, the shapes, dimensions and the
like of the recessed holes and the ridge portions may be any of
those described above.
[0168] When an occupant sits on the sitting surface of the seat pad
1D and the thighs of the occupant are in contact with the
under-right thigh portion of the seat pad, mainly the ridge
portions 9 are compression-deformed at the initial stage and then
the entire part of the under-thighs portion of the seat pad 1D
sinks downward almost evenly, whereby the occupant feels good
sensation of the pad making a stroke movement. Thereafter, as the
occupant's body further sinks in the seat and the ridge portions 9
are further compression-deformed, the repellent force of the ridge
portions 9 increases strong enough to stably support the occupant's
body.
[0169] Although the recessed holes 8 and the ridge portions 9 are
provided in the rear surface of the seat pad below the under-thighs
portion 2 in FIGS. 17 to 19, the recess holes and the ridge
portions may be provided in both of the rear surfaces of the seat
pad below the under-thighs portion 2 and the under-buttocks portion
3 or may be provided in either the rear surface of the seat pad
below the under-thighs portion 2 or the rear surface of the seat
pad below the under-buttocks portion 3.
[0170] Further, the rear surface of the seat pad below the pelvis
contact portion 23 (see FIG. 7) may be made flat to firmly support
the pelvis, while the rear surface of the seat pad below other
portions of the sitting surface 22 may be provided with the
recessed holes to enhance sensation of the pad making a stroke
movement.
[0171] In the present invention, sensation of the pad making a
stroke movement may be improved by forming recessed holes in the
rear surface of a seat back pad. FIG. 20 is a front view of a seat
back pad showing one example thereof. Cover fitting longitudinal
grooves 41, 41 are formed to continuously extend in the vertical
direction on the left and right hand sides of the front surface of
a seat back pad 40. Cover fitting lateral grooves 42, 43 are formed
to extend in the left-right direction and communicate with the
cover fitting longitudinal grooves 41, 41. The recessed holes as
any of those described above are formed in the rear surface of the
seat back pad in a back contact region 44 above the upper cover
fitting lateral groove 42, thereby improving sensation of the pad
making a stroke movement in the back contact region 44. The
recessed holes may also be formed in the rear surface of an
intermediate region 45 below the back contact region 44. It is
preferable not to form recessed holes in a lumbar contact portion
46 below the intermediate region 45, to improve the lumbar
supporting properties.
[0172] The lower edge of the back contact region substantially
corresponds with the cover fitting lateral groove 42. The distance
between the lower edge of the back contact region and the sitting
surface of the seat is preferably in the range of 250 to 500 mm,
more preferably in the range of 300 to 400 mm. The distance between
the upper edge of the back contact region and the upper end of the
seat back pad 40 is preferably not larger than 100 mm and more
preferably in the range of 20 to 50 mm or so.
[0173] [Seat for Vehicle, Including a Cushion Pad and a Back Pad
Each Having Recessed Holes Formed Therein]
[0174] A seat for a vehicle according to an embodiment of the
present invention includes a seat cushion pad and a seat back pad
each having recessed holes formed therein.
[0175] FIG. 21 is a front view of a back pad of the seat for a
vehicle of such an embodiment as described above.
[0176] Any of the seat cushion pads shown in FIGS. 1 to 16 may be
used as the cushion pad of the seat for a vehicle of the present
embodiment.
[0177] As shown in FIG. 21, cover fitting longitudinal grooves 51,
51 are formed to continuously extend in the vertical direction on
the left and right hand sides of the front surface of a seat back
pad 50. Cover fitting lateral grooves 52, 53 are formed to extend
in the left-right direction and communicate with the cover fitting
longitudinal grooves 51, 51. Recessed holes are formed in the front
surface of a back contact portion 54 (defined by two-dot lines in
FIG. 21) above the upper cover fitting lateral groove 52, to
improve soft sensation of touch in the back contact portion.
[0178] The lower edge of the back contact portion 54 substantially
corresponds with the cover fitting lateral groove 52. The distance
between the lower edge of the back contact portion 54 and the
sitting surface of the seat is preferably in the range of 250 to
500 mm, more preferably in the range of 300 to 400 mm. The distance
between the upper edge of the back contact portion 54 and the upper
end of the back pad 50 is preferably not larger than 100 mm and
more preferably in the range of 20 to 50 mm or so.
[0179] Recessed holes may also be formed in a region 55 between the
cover fitting lateral grooves 52 and 53. It is preferable not to
form recessed holes in a lumbar supporting portion 56 below the
cover fitting lateral groove 53.
[0180] The upper portions 57 (defined by two-dot lines in FIG. 21)
of the side portions, i.e. the side regions of the back contact
portion 54, may be made soft by forming recessed holes.
[0181] In the present embodiment, the shapes, the areas of an
openings, and the like of the recessed holes may be any of those
described above.
[0182] In the present embodiment, the recessed holes of the back
pad is made deeper than the recessed holes of the cushion pad.
Accordingly, the back pad is made softer than the cushion pad. The
average depth of the recessed holes in the cushion pad is
preferably in the range of 2 to 40 mm, more preferably in the range
of 5 to 10 mm, and the average depth of the recessed holes in the
back pad is preferably 2 to 20 times and more preferably 5 to 10
times as much as the average depth of the recessed holes in the
cushion pad.
[0183] When an occupant sits on the sitting surface of the cushion
pad of the vehicle seat as structured above and leans against the
back contact portion of the back pad so that the thighs and the
back of the occupant are in contact with the under-thighs portion
and the back contact portion of the seat pad, respectively, mainly
the ridge portions between the recessed holes are
compression-deformed at the initial stage and the occupant feels
soft sensation of touch. Then, as the ridge portions are further
compression-deformed, the repellent force of the ridge portions
increases and the occupant's body is stably supported.
[0184] The recessed holes are formed in the respective occupant
contact surfaces of the cushion pad and the back pad in the
embodiment of FIG. 21. However, recessed holes may be formed in the
respective surfaces opposite to the occupant contact surfaces of
the cushion pad and the back pad such that the recessed holes in
the back pad are deeper than the recessed holes in the cushion pad.
In this case, sensation of the pad making a stroke movement more
improves in the back pad than in the cushion pad. In a case where
recessed holes are formed in the surface opposite to the occupant
contact area, the average depth of the recessed holes in the back
pad is preferably 2 to 20 times and more preferably 5 to 10 times
as much as the average depth of the recessed holes in the cushion
pad.
EXAMPLES
[0185] Examples and Comparative Examples will be described
hereinafter. For convenience, Comparative Example 1 will be
described first.
Comparative Example
[0186] A seat pad formed of polyurethane foam having density of 64
kg/cm.sup.3 and 25% hardness of 24 kgf/200 mm.phi. was prepared. No
recessed holes 8 are formed in the seat pad. A load-stroke curve at
the sitting surface of the seat pad was obtained. In the
measurement of the load-stroke curve, a load applying means having
diameter of 200 mm was pressed against the sitting surface at a
rate of 0.8 mm/sec and the reaction force was measured. The result
is shown in FIG. 22. The volume ratio of the ridge portions is 100%
because no recessed holes are formed in the seat pad.
Example 1
[0187] A seat pad as shown in FIGS. 1 to 3 was produced by
providing projecting portions in a surface (a cavity surface) for
molding an under-thighs portion of a mold for use in molding of
Comparative Example 1 and using the same urethane raw liquid as
Comparative Example 1. The dimensions of w, t and h are 20 mm, 4 mm
and 10 mm, respectively. The volume rate of the ridge portions 9 in
Example 1 is 33.3%. The density and the 25% hardness of
polyurethane are 64 kg/cm.sup.3 and 19 kgf/200 mm.phi.,
respectively. A load applying means was pressed against the
under-thighs portion of the seat pad in a manner similar to
Comparative Example 1 and a load-stroke curve was obtained. The
result is shown in FIG. 22.
Comparative Example 2
[0188] A seat pad main body was prepared in the same manner as in
Comparative Example 1, except that the sitting surface was
structured as a shallowly recessed portion of 10 mm depth.
[0189] Further, there was separately prepared a slab having
thickness of 10 mm by using slab urethane foam having density of 64
kg/cm.sup.3 and 25% ILD hardness of 24 kgf/200 mm.phi..
[0190] The slab thus prepared was attached to the recessed portion
of the seat pad main body by an adhesive, whereby a seat pad was
prepared. A load applying means was pressed against the seat pad in
a manner similar to Comparative Example 1 and a load-stroke curve
was obtained. The result is shown in FIG. 22.
[0191] [Consideration]
[0192] As shown in FIG. 22, the load-stroke curve of the seat pad
of Example 1 resembles the load-stroke curve of the seat pad of
Comparative Example 2 (the slab-attaching type). It is thus
confirmed that the seat pad of the present invention is excellent
in soft sensation of touch, of the surface thereof, and the
properties of supporting the occupant's body.
[0193] In contrast, load significantly increases when a stroke
exceeds approximately 1 mm in Comparative Example 1, as compared
with Example 1 and Comparative Example 2. Accordingly, it is
confirmed that the seat pad of Comparative Example 1 lacks soft
sensation of touch.
Example 2
[0194] A seat pad as shown in FIGS. 1 to 3 was prepared by setting:
the dimensions w, t and h at 26 mm, 4 mm and 10 mm, respectively;
the ratio of areas of the ridge portions 9 in the total areas of
the recessed holes 8 and the ridge portions 9 at 25%; the volume
rate of the ridge portions 9 at 25%; and the density and the 25%
hardness at 64 kg/cm.sup.3 and 18 kgf/200 mm.phi., respectively. A
load applying means was pressed against the seat pad in a manner
similar to Comparative Example 1 and a load-stroke curve was
obtained. The result is shown in FIG. 23.
Example 3
[0195] A seat pad was prepared in the same manner as in Example 2,
except that the recessed holes were structured as shown in FIG. 5.
The length L of the largest diagonal line of the equilateral
hexagon is 28 mm, t=4 mm and the depth h=10 mm. The volume rate of
the ridge portions 11 is 25%. The measurement result of a
load-stroke curve is shown in FIG. 23.
Comparative Example 3
[0196] A seat pad main body was prepared in the same manner as in
Comparative Examples 2 and 3, except that the sitting surface was
structured as a shallowly recessed portion of 10 mm depth.
[0197] Further, there was separately prepared a slab having
thickness of 10 mm by using slab urethane foam having density of 30
kg/cm.sup.3 and 25% ILD hardness of 7 kgf/200 mm.phi..
[0198] The slab thus prepared was attached to the recessed portion
of the seat pad main body by an adhesive, whereby a seat pad was
prepared. A load-stroke curve of the seat pad was obtained. The
result is shown in FIG. 23.
Examples 4 and 5, Comparative Example 4
[0199] Seat pad main body was prepared in the same manners as in
Examples 2, 3 and Comparative Example 3, respectively, except that
the density of the polyurethane foam was changed to 67 kg/m.sup.3.
A load-stroke curve was measured for each of Example 4, Example 5
and Comparative Example 4 thus performed in the same manner as the
foregoing Examples. The results are shown in FIG. 24.
[0200] [Consideration]
[0201] As shown in FIG. 23, the load-stroke curves of the seat pads
of Example 2 and Example 3 each resemble the load-stroke curve of
the seat pad of Comparative Example 3 (the slab-attaching type). It
is thus confirmed that the seat pads of the present invention are
excellent in soft sensation of touch, of the surfaces thereof, and
the properties of supporting the occupant's body.
[0202] Further, as is obvious from FIG. 24, soft sensation of
touch, of a seat pad surface, changes as the density of
polyurethane foam changes, although the same configuration is
maintained therein. Accordingly it is confirmed that soft sensation
of touch, of a seat pad surface, can be adjusted by controlling the
density and hardness of the pad.
Comparative Example 5
[0203] A seat pad was prepared by using polyurethane foam having
density of 64 kg/cm.sup.3 and 25% hardness of 24 kgf/200 mm.phi.. A
load-stroke curve at the sitting surface of the seat pad was
obtained in the same as in the foregoing Examples. The result is
shown in FIG. 25. No recessed holes are formed in the seat pad. The
volume rate of the ridge portions is 100% because no recess holes
exist.
Example 6
[0204] A seat pad having a softened under-thighs portion was
produced by using the same urethane raw liquid as Comparative
Example 5 and providing projecting portions in a surface (a cavity
surface) for molding an under-thighs portion of a mold for molding
such that circular recessed holes as shown in FIG. 6 are formed in
the under-thighs portion. The diameter, the depth, and the distance
between the centers of adjacent recessed holes 12 were set at 12
mm, 5 mm, and 19 mm, respectively. The volume rate of the ridge
portions 13 is 70%. A load applying means was pressed against the
under-thighs portion of the seat pad in the same manner as in
Comparative Example 5 to obtain a load-stroke curve. The result is
shown in FIG. 25.
Example 7
[0205] A seat pad was prepared in the same manner as in Example 6,
except that the diameter, the depth, and the distance between the
centers of adjacent recessed holes 12 were set at 19 mm, 5 mm, and
26 mm, respectively, and the volume rate of the ridge portions 13
was 50%.
Example 8
[0206] A seat pad was prepared in the same manner as in Example 6,
except that the diameter, the depth, and the distance between the
centers of adjacent recessed holes 12 were set at 24 mm, 5 mm, and
30 mm, respectively, and the volume rate of the ridge portions 13
was 40%.
Example 9
[0207] A seat pad was prepared in the same manner as in Example 6,
except that the diameter, the depth, and the distance between the
centers of adjacent recessed holes 12 were set at 28 mm, 5 mm, and
32 mm, respectively, and the volume rate of the ridge portions 13
was 25%.
[0208] A load applying means was pressed against the under-right
thigh portion of each of the seat pads of Examples 7 to 9 in the
same manner as in Comparative Example 1 to obtain a load-stroke
curve. The results are shown in FIG. 25.
[0209] [Consideration]
[0210] As shown in FIG. 25, the under-right thigh portions of the
seat pads of Examples 6 to 9 are softer than that of Comparative
Example 5, respectively. Further, it is confirmed that the seat pad
is made softer as the volume rate of the ridge portions drops.
Residual strain after being subjected to 50% compression for 22
hours in a bath at 50.degree. C. (constant) and humidity of 95%
(constant) was measured for each of the under-thighs portions of
the seat pads of Examples 6 to 9. The results are shown in FIG.
26.
[0211] Further, the corner edges of each ridge portion on the base
end side and the tip end side were provided with curved surfaces
(R=3.5 mm), respectively, in Example 7. It was confirmed that the
residual strain after compression was then decreased from 19.8% to
18.8%.
* * * * *