TECHNICAL FIELD

The present invention relates to a vehicle seat to be installed in a vehicle such as an automobile.

BACKGROUND ART

As a vehicle seat to be installed in a vehicle such as an automobile, for example, Patent Document 1 discloses a seat comprising a cushion frame and a plate-shaped cushion panel running between front portion and rear portion of the cushion frame to support a pad. In this technical scheme, the cushion panel has a hole formed in a position corresponding to ischial bones of an occupant to relieve pressure applied on the ischial bones and their vicinities of the occupant.

CITATION LIST

Patent Literatures

Patent Document 1: JP 2015-085840 APatent Document 2: JP 2001-245744 A

SUMMARY OF INVENTION

In the conventional art, however, the hole formed in a position corresponding to the ischial bones or coccygeal bone would disadvantageously reduce the rigidity of the cushion panel.

In view of this, it is an object of the present invention to seek to achieve the both features: reduction of pressure applied on the ischial and coccygeal bones and their vicinities of an occupant; and enhancement of rigidity of the plate-shaped member for supporting an occupant.

In order to resolve the above-described issue, a vehicle seat according to the present invention comprises: left and right side frames disposed left and right separately from each other; a first support member disposed between the left and right side frames to support an occupant; and left and right second support members joined to left and right sides of the first support member and having left and right outer sides supported by the side frames to support the occupant in conjunction with the first support member.

The first support member is a plate-shaped member, and has left and right ischial region through holes formed in positions corresponding to ischial bones of the occupant.

The second support members are located at least partially within front and rear limits defined by an expanse of the ischial region through holes.

With this configuration, the pressure applied on the ischial bones and their vicinities of the occupant can be relieved through the ischial region through holes; thus, the pressure applied on the ischial bones of the occupant can be reduced. In addition, since the second support members supported by the side frames serve to support the both side regions of the buttocks and the femoral regions of the occupant, the pressure applied on the ischial bones and their vicinities can be further reduced. Since part of the second support members is located within the front and rear limits defined by the expanse of the ischial region through holes, the portion of the first support member around the ischial region through holes can be reinforced by the second support members supported by the side frames, with the result that the rigidity of the plate-shaped first support member can be enhanced. Moreover, stable support of an occupant can also be achieved without causing the occupant to experience discomfort.

Accordingly, both of reduction of pressure applied on the ischial bones and their vicinities and enhancement of rigidity of the plate-shaped member for supporting an occupant can be made mutually compatible.

The second support members may comprise a first joint portion joined to the first support member, and the first joint portion may be located within the front and rear limits defined by the expanse of the ischial region through holes.

With this feature, the portion of the first support member around the ischial region through holes can be reinforced by the first joint portion.

The second support members may comprise a second joint portion joined to the first support member, and the second joint portion may be located rearward relative to the ischial region through holes.

With this feature, the first support member can be supported firmly by the second support members.

A slit may be formed at a peripheral edge of the ischial region through holes.

With this feature, the portion around the ischial region through holes can be made deformable by the slit; thus, the pressure applied on the ischial bones and their vicinities of the occupant can be reduced gradually with decreasing distance from the ischial bones.

The first support member may have a coccygeal region through hole formed in a position corresponding to a coccygeal bone of the occupant, and part of the second support members may be located within front and rear limits defined by an expanse of the coccygeal region through hole.

With this feature, the pressure applied on the coccygeal bone and its vicinity of the occupant can be relieved through the coccygeal region through hole, and the portion of the first support member around the coccygeal region through hole can be reinforced by the second support members.

The vehicle seat as described above may further comprise a pair of connecting members disposed in front and behind separately from each other, each connecting member connecting the left and right side frames, wherein the first support member may comprise a plurality of wires running between the pair of connecting members, and a plastic plate by which the plurality of wires are joined together.

With this feature, the first support member is reinforced by the wires, so that the rigidity of the first support member can be increased.

The second support members may comprise a first engagement portion engageable with the wire.

With this feature, the first support member and the second support members can be joined firmly by the wire.

The vehicle seat as described above may further comprise a cover member with which a laterally inner side of a rear end portion of the side frames is covered, and the second support member may be formed integrally with the cover member in one piece.

With this feature, the rigidity of the second support member can be increased.

The aforementioned slit may be configured to extend in a lateral direction, and located within front and rear limits defined by an expanse of the first joint portion.

With this configuration, in which the slit and the joint portion may be so located as to have their expanses in the front-rear direction overlapping one another, the pressure-supporting strength of the first support member can thus be kept from lowering.

The aforementioned plastic plate may comprise a second engagement portion engageable with the wire, and the slit may preferably be configured to extend in a front-rear direction and located at least partially within front and rear limits defined by an expanse of the second engagement portion.

With this configuration, in which the slit and the second engagement portion are so located as to have their expanses in the front-rear direction overlapping one another, the pressure-supporting strength of the first support member can thus be kept from lowering.

The vehicle seat as described above may further comprise a third support member that is more flexible than the first support member, and the third support member may be provided on the first support member in such a manner as to close at least partially the ischial region through holes.

With this feature, the ischial bones of the occupant can be supported properly by the third support member configured to be more flexible than the first support member, and the pressure applied on the ischial bones and their vicinities of the occupant can be relieved through the third support member provided at the ischial region through holes.

The vehicle seat as described above may further comprise a third support member that is more flexible than the first support member, and the third support member may be provided on the first support member in such a manner as to close at least partially the coccygeal region through hole.

With this feature, the coccygeal bone of the occupant can be supported properly by the third support member configured to be more flexible than the first support member, and the pressure applied on the coccygeal bone and its vicinities of the occupant can be relieved through the third support member provided at the coccygeal region through hole.

