JP2014008843A - Vehicle seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle seat which has a support member efficiently supporting an area near occupant's lumber part only at a necessary range and concurrently includes a lightweight lumber part support part.SOLUTION: A vehicle seat includes: a seat back frame including a pair of left and right side frames; and a support member which is attached to an area between the side frames, supports an occupant from the rear side of the seat, and can deflect to the rear side of the seat when subjected to a load of the occupant. The support member includes a lumbar part support part which supports a lumber part of the occupant and in which both seat width direction ends are attached to the side frames. The lumbar part support part includes a pair of lumbar quadrate muscle support parts 43, which supports a pair of lumbar quadrate muscles 63 of the occupant from the rear side of the seat, at two positions sandwiching a seat width direction center. The lumbar quadrate muscle support parts 43 protrude to the upper side of the seat relative to an upper end of the lumber part support part in the seat width direction center.

Description

  The present invention relates to a vehicle seat, and more particularly, to a vehicle seat including a support member that receives a load of an occupant in a region surrounded by a seat back frame.

Conventionally, a vehicle seat back provided with a support member that supports the back of an occupant has been proposed (for example, Patent Document 1).
In Patent Document 1, a substantially plate-like seat back board is fixed to the seat back frame so as to fill an opening surrounded by the seat back frame, and an upper back spring portion and a lower back spring are provided above and below the seat back board. The part is integrally formed. The upper back spring portion and the lower back spring portion are formed of a wave-shaped member in a plane cross section, and both ends in the seat width direction are fixed to the side frame via the seat back board, so that the chest above the back of the occupant And the lower back portion of the waist can be supported from behind.
The lower back spring portion that supports the occupant's lower back portion is formed by arranging strip-like corrugated plate members parallel to the upper and lower three stages in the seat back height direction.

JP 2012-71627 A

However, in the invention of Patent Document 1, the lower back spring portion is formed by arranging strip-like corrugated plate members in parallel in three upper and lower stages in the seat back height direction, and further, the seat back of the lower back spring portion. Since a substantially plate-like seat back board is required for attachment to the frame, the support member that supports the back of the occupant has been enlarged. In addition, since the lower back spring part is simply formed by arranging the strip-like corrugated plate member in parallel with the upper and lower three stages in the seat back height direction, it is configured to support the occupant's waist area more widely than necessary. The lower back spring part itself was also large.
In addition, development of a support member that has high rigidity, suppresses an increase in the size of the lumbar support part that supports the lumbar part, and can stably support the lumbar part has been demanded.

The present invention has been made in view of the above problems, and an object of the present invention is a vehicle seat provided with a support member that receives a load of an occupant in an area surrounded by a seat back frame. An object of the present invention is to provide a vehicle seat having a lightweight waist support portion while the member efficiently supports only the necessary range around the waist of the occupant.
Another object of the present invention is to provide a vehicle seat provided with a support member that has high rigidity, suppresses an increase in size of a waist support portion that supports the waist, and can stably support the waist.

  According to the vehicle seat of claim 1, the subject is mounted between a seat back frame having a pair of left and right side frames and the side frame, supports an occupant from the rear of the seat, and loads the occupant. A support member capable of receiving and flexing rearward of the seat, wherein the support member supports a waist portion of the occupant, and both ends in the seat width direction are on the side frame. A pair of lower back muscle support portions that support the pair of lower back muscles of the occupant from the rear of the seat at two positions sandwiching the center in the seat width direction. This is solved by the fact that the lower back muscle support part protrudes above the seat from the upper end of the lower part support part at the center in the seat width direction.

  As described above, since the lumbar muscle support portion that supports the lumbar muscles protrudes above the seat from the upper end of the lumbar support portion, the lumbar muscles that need to be supported can be supported and supported. Since the member can be reduced in size by notching or forming a hole between the unnecessary pair of waist square muscles, the waist support portion can be reduced in weight and at the same time stable support can be achieved.

At this time, as in claim 2, the lumbar support part includes a sacrum support part that protrudes below the seat from the lumbar muscle support part at the center in the seat width direction and supports the sacrum of the occupant. It is preferable that
Since it comprises in this way, the support of the waist | hip | lumbar part becomes stable by supporting a sacrum.

At this time, as in claim 3, it is preferable that the distance in the sheet width direction between the pair of lumbar muscle support parts is larger than the length in the sheet width direction of the sacral support part.
Since it comprises in this way, the rigidity of a waist-shaped muscle support part is securable.

At this time, as described in claim 4, the waist support portion includes attachment portions for attachment to the side frames at both ends of the waist support portion in the seat width direction, and the upper portion of the attachment portion above the seat. An end portion is positioned below the seat above an end portion above the seat of the lumbar muscle support portion, and an end portion below the seat of the attachment portion is from an end portion below the seat of the sacrum support portion. Is also preferably located above the seat.
Since it comprises in this way, the attachment part can support the passenger | crew's load received by a waist square muscle support part and a sacrum support part stably, and it can suppress the enlargement of a waist support part.

At this time, as in claim 5, it is preferable that the attachment portion is provided so as to be within a range below the seat and above the center of the sacral support portion from the center of the lumbar muscle support portion. is there.
Since it is comprised in this way, while being able to support the passenger | crew's load received by a waist-shaped muscle support part and a sacral support part more stably by an attaching part, the enlargement of a waist support part can be suppressed further.

At this time, as in claim 6, the attachment portion has the same height as the center of gravity of an inverted triangle connecting the center of the pair of lumbar muscle support portions and the center of the sacral support portion with a line. It is suitable if it is provided.
Since it comprises in this way, the load of the passenger | crew who receives in a hippocampus muscle support part and a sacrum support part can be supported more stably by an attaching part.

At this time, as described in claim 7, it is preferable that an end portion of the waist support portion above the seat is provided below the seat with respect to the center of the waist square muscle support portion.
Since it comprises in this way, a waist support part can be reduced in size and the weight of the whole support member can be reduced.

At this time, it is preferable that the lower end portion of the waist support portion is provided above the seat with respect to the center of the sacrum support portion.
Since it comprises in this way, a waist support part can be reduced in size and the weight of the whole support member can be reduced.

According to the first aspect of the present invention, since the lumbar muscle support portion that supports the lumbar muscles protrudes above the seat from the upper end of the lumbar support portion, the lumbar muscles that need to be supported by the back portion are supported. At the same time, a position sandwiched between a pair of lower back muscles that do not need to be supported can be cut out or a hole can be formed, so that the waist support portion can be reduced in weight and at the same time stable support can be achieved.
According to the invention of claim 2, the lumbar part can be supported stably by supporting the sacrum.

According to the invention of claim 3, it is possible to ensure the rigidity of the lower back muscle support portion.
According to the fourth aspect of the present invention, the mounting portion can stably support the load of the occupant received by the lower back muscle support portion and the sacral support portion, and at the same time, increase in size of the lower back support portion can be suppressed.
According to the fifth aspect of the present invention, the mounting portion can more stably support the occupant's load received by the lower back muscle support portion and the sacral support portion, and at the same time, the increase in the size of the lower back support portion can be further suppressed.

According to the sixth aspect of the present invention, the load on the occupant received by the lower back muscle support portion and the sacrum support portion can be more stably supported by the attachment portion.
According to the invention of claim 7, the waist support portion can be reduced in size, and the weight of the entire support member can be reduced.
According to invention of Claim 8, a waist support part can be reduced in size and the weight of the whole support member can be reduced.

1 is an external view of a vehicle seat according to an embodiment of the present invention. It is a perspective view which shows the state which attached the chest resin spring and the waist resin spring to the seat back frame of the vehicle seat which concerns on one Embodiment of this invention. It is explanatory drawing which shows the state which attached the chest resin spring which concerns on one Embodiment of this invention to the side frame. It is AA sectional drawing of FIG. It is sectional drawing which shows the state which attached the chest resin spring which concerns on one Embodiment of this invention to the side frame which concerns on a modification. It is explanatory drawing which shows the state which attached the waist | lumbar part resin spring which concerns on one Embodiment of this invention to the side frame. It is BB sectional drawing of FIG. It is explanatory drawing which shows the position which the spring part of a chest resin spring and a waist resin spring supports a passenger | crew's chest and waist from a back part at the time of a passenger | crew's seating. It is explanatory drawing of the spring part of a chest resin spring and a waist resin spring. It is explanatory drawing which shows the modification of a chest resin spring. It is explanatory drawing which shows the other modification of a chest resin spring. It is explanatory drawing which shows the other modification of a chest resin spring. It is explanatory drawing which shows the position of a passenger | crew's hippocampus muscle and sacrum. It is explanatory drawing which shows the example which contrasted the amount of bending of the chest resin spring which concerns on one Embodiment of this invention with the support member which concerns on a prior art example.

Hereinafter, a vehicle seat S according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an external view of a vehicle seat according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state in which a chest resin spring and a waist resin spring are attached to a seat back frame of a vehicle seat according to an embodiment of the present invention. FIG. 3 is an explanatory view showing a state in which the chest resin spring according to the embodiment of the present invention is attached to the side frame. 4 is a cross-sectional view taken along line AA in FIG. FIG. 5 is a cross-sectional view showing a state in which a chest resin spring according to an embodiment of the present invention is attached to a side frame according to a modification. FIG. 6 is an explanatory view showing a state in which the waist resin spring according to the embodiment of the present invention is attached to the side frame. 7 is a cross-sectional view taken along line BB in FIG. FIG. 8 is an explanatory diagram showing positions where the spring portions of the chest resin spring and the waist resin spring support the passenger's chest and waist from the back when the passenger is seated. FIG. 9 is an explanatory diagram of the spring portions of the chest resin spring and the waist resin spring. FIG. 10 is an explanatory view showing a modification of the chest resin spring. FIG. 11 is an explanatory view showing another modification of the chest resin spring. FIG. 12 is an explanatory view showing still another modified example of the chest resin spring. FIG. 13 is an explanatory diagram showing the positions of the occupant's lower back muscles and sacrum. FIG. 14 is an explanatory diagram showing an example in which the amount of bending of the chest resin spring according to the embodiment of the present invention is compared with the support member according to the conventional example.

  As shown in FIG. 1, the vehicle seat S according to the present embodiment includes a seat back S1, a seat portion S2, and a headrest S3. The seat back S1 and the seat portion S2 are cushioned on a seat frame (not shown). Pads 1a and 2a are placed and covered with skin materials 1b and 2b. The headrest S3 is formed by covering the core material (not shown) with the pad material 3a and covering with the skin material 3b, and is supported by the headrest pillar 14.

The seat back S1 mounts the cushion pad 1a on the seat back frame 1, is covered with a skin material 1b from above the cushion pad 1a, and supports the back of the occupant from the rear. As shown in FIG. 2, the seat back frame 1 includes a pair of side frames 20 that are spaced apart from each other and extend in the vertical direction, an upper frame 11 that connects the upper ends of the pair of side frames 20, and a lower end The frame is constituted by a lower frame 12 connecting the parts.
The upper frame 11 is provided with a pillar support portion 13 for supporting the headrest pillar 14.

The side frame 20 is formed by pressing a sheet metal, and is formed of a substantially D-shaped substantially plate body in which a front end side is curved and a lower portion of the front end projects forward. As shown in FIGS. 2 to 4, the substantially flat side portion 21, the front flange portion 22 formed by folding the front end portion of the side portion 21 inward in a U shape, and the rear end portion in an L shape. A pair of side frames having a rear flange portion 23 bent to the inside of the seat and an inner end flange portion 24 having an end on the seat inner side of the rear flange portion 23 bent further toward the front inside the seat. 20, both ends of a chest resin spring 30 and a waist resin spring 40 as support members are attached.
A space is formed in the seat back S1 at a position on the rear side of the rear flange portion 23 and facing the rear flange portion 23, and the chest resin spring 30 and the waist resin spring 40 are provided in this space. The seat can be moved backward in the seat.

As shown in FIGS. 2 to 4, the pair of side frames 20 are engaged with the hole 25 for inserting the chest resin spring 30 and the end of the chest resin spring 30 at positions close to the upper ends. 2, 6, and 7, a locking portion 27 for locking a waist resin spring 40 as a waist support portion is provided at a position below the center as shown in FIGS. 2, 6, and 7. Is provided.
As shown in FIGS. 3 and 4, the hole portion 25 is located in the vertical direction along both side edges of the rear flange portion 23 in the sheet width direction at a position outside the seat width direction center of the rear flange portion 23. It extends in a slit shape.

The hole 25 may be formed in the outer end portion of the rear flange portion 23 outside the seat. If comprised in this way, since the full length of the spring part 31 of the chest resin spring 30 will become long, the bending amount is ensured, and at the same time, the hole part 25 is formed at the highly rigid end part. Can be prevented from decreasing.
Further, the hole portion 25 may be provided in the side portion 21. When the hole part 25 is provided in the side part 21, since the full length of the spring part 31 of the chest resin spring 30 becomes long, the bending amount is ensured. Further, as shown in FIG. 5, the rear flange portion 23 may be provided near the center in the sheet width direction.

  As shown in FIGS. 3 and 4, the locking portion 26 is provided on the side portion 21 of the side frame 20, and a curved portion 26 a formed so as to protrude toward the inside of the vehicle seat S by drawing. The hole 26b is formed so as to open up and down the curved portion 26a and extend in the up-down direction. As shown in FIGS. 6 and 7, the locking portion 27 is configured in the same manner as the locking portion 26.

  The chest resin spring 30 is made of a resin and is formed of a corrugated plate body whose flat cross section is displaced in the longitudinal direction of the seat, and corresponds to a pair of scapulas 53 of an occupant as shown in FIGS. A spring portion 31 formed such that the upper end of the position is high and the lower end of the position corresponding to the ninth thoracic vertebra 52 is slightly lower than the position sandwiched between the pair of scapulas 53; And a mounting portion 34 extending toward both sides at a height near the center of the highest position and the lowest position of the spring portion 31.

FIG. 8 shows the positions at which the spring part 31 of the chest resin spring 30 and the spring part 41 of the waist resin spring 40 support the passenger's chest and waist from the back when the passenger is seated.
As shown in FIG. 8, the spring portion 31 is provided at the center of the spring portion 31 in the seat width direction, and on the left and right of the ninth thoracic vertebra support portion 32 that supports the ninth thoracic vertebra 52 of the occupant. And a pair of scapula support portions 33 that support the left and right scapulas 53 of the occupant.

As shown in FIG. 9, the ninth thoracic vertebra support portion 32 includes a trapezoidal plate-like portion that is provided at the center of the chest resin spring 30 in the seat width direction and projects downward from the seat.
The ninth thoracic vertebra support portion 32 has an upper end 32u below the upper end 34u of the attachment portion 34, a lower end 32l below the lower end 34l of the attachment portion 34, and a lower end of the ninth thoracic vertebra support portion 32. The left and right ends of 32l and the lower end 34l of the attachment portion 34 are connected by an inclined side inclined outward from the lower end 32l toward the upper side of the seat. The lower end 34l forms the lower end of the chest resin spring 30.

A pair of scapula support portions 33 each including a trapezoidal plate-like portion projecting upward from the seat is provided on the left and right seat outer sides of the ninth thoracic vertebra support portion 32.
The scapula support portion 33 has a lower end 33 l above the seat with respect to the lower end 34 l of the attachment portion 34, an upper end 33 u above the seat with respect to the upper end 34 u of the attachment portion 34, and an upper end 33 u of the scapula support portion 33. The left and right ends of the mounting portion 34 and the upper end 34u of the attachment portion 34 and the upper end 32u of the ninth thoracic vertebra support portion 32 are connected by an inclined side inclined outward from the scapula support portion 33 from the upper end 33u downward to the seat. .

A distance L1 in the seat width direction between the pair of scapula support portions 33 is larger than a length L2 of the ninth thoracic vertebra support portion 32 in the seat width direction. Since it comprises in this way, since the part which exists between the scapula support parts 33 can be made small, weight reduction is attained. Since the width in the vertical direction of the seat at the portion from the scapula support portion 33 to the ninth thoracic vertebra support portion 32 becomes small, it becomes easy to bend.
In addition, for example, an inclination inclined between the end of the upper end 33u of the upper end 33u of the scapula support portion 33 and the upper end 30u of the chest resin spring 30 toward the inner side of the scapula support portion 33 from the upper end 33u toward the lower side of the seat. Conversely, the length L2 in the seat width direction of the ninth thoracic vertebra support portion 32 may be formed larger than the distance L1 in the seat width direction between the pair of scapula support portions 33 by connecting the sides. If comprised in this way, the rigidity of the scapula support part 33 is securable.

The upper end 34u of the attachment portion 34 is located below the seat from the upper end 33u of the scapula support portion 33, and the lower end 34l of the attachment portion 34 is located above the seat from the lower end 32l of the ninth thoracic vertebra support portion 32.
The attachment portion 34 is provided so as to be within the range below the seat from the center 33 c of the scapula support portion 33 and above the seat from the center 32 c of the ninth thoracic vertebra support portion 32. Here, the center 33c of the scapula support portion 33 is the center in the seat vertical direction and the width direction of the scapula support portion 33, and the center 32c of the ninth thoracic vertebra support portion 32 is the seat vertical direction of the ninth thoracic vertebra support portion 32. It is the center in the direction and the width direction.

The attachment portion 34 is a straight line GL obtained by extending the center G of an inverted triangle formed in the seat width direction when the center 33c of the pair of scapula support portions 33 and the center 32c of the ninth thoracic vertebra support portion 32 are connected. The portion 34 is provided so as to pass between the upper end 34u and the lower end 34l.
The upper end 32 u of the ninth thoracic vertebra support part 32 is located below the seat from the center 33 c of the scapula support part 33.
The lower end 33l of the scapula support portion 33 is positioned above the seat with respect to the center 32c of the ninth thoracic vertebra support portion 32.

The spring portion 31 is formed thinner than the attachment portion 34, and the spring portion 31 is easily bent, and the attachment portion 34 ensures attachment rigidity.
The chest resin spring 30 is arranged along the surface constituted by the seat back frame 1 in a normal time other than at the time of a rear collision, and can support the scapula 53 and the ninth thoracic vertebra 52 of the occupant.

As shown in FIG. 3, the attachment portion 34 is a portion closer to the end portion than a portion passing through the hole 25 at the time of attachment. The attachment portion 34 includes an insertion portion 34a inserted through the hole portion 25, and a bent portion 34b bent along the inner surface of the bent portion 23c between the rear flange portion 23 and the side portion 21 of the side frame 20, A pair of locking pieces 34c that are locked to the locking portion 26 are formed at the tip.
Since the bent portion 34b is provided in the attachment portion 34, the attachment rigidity is improved. Further, the bent portion 34b is supported in contact with the inner surface of the bent portion 23c of the side frame, and the support rigidity is improved.

The locking piece 34c is formed by a pair of thin rod-like bodies extending horizontally from the upper end and the lower end of the mounting portion 34 to the front of the seat and vertically bent so that the end portions face each other. The end of the portion 34 and the locking piece 34c are substantially C-shaped. The locking piece 34 c fixes the tip of the attachment portion 34 to the inner surface of the side frame 20 by inserting the tip portions of the pair of thin rod-like bodies into the locking portion 26.
When attaching the chest resin spring 30 to the side frame 20, first, the attachment portion 34 is inserted into the hole portion 25. The pair of locking pieces 34c are deformed in directions away from each other so as to open the mouth due to the elasticity of the resin, and therefore, the locking pieces 34c are pushed along the side frames 20 from the seat rear side to the locking portion 26. The contact portion 26 is locked by being pushed into the locking portion 26.

In the present embodiment, the chest resin spring 30 is formed of a resin corrugated plate body, but a known metal zigzag spring called an S spring may be used instead of the chest resin spring 30. Even when the zigzag spring is used, the both ends of the zigzag spring are inserted through the hole 25 from the rear side of the side frame 20, and the locking provided on the inner surface of the side portion 21 of the side frame 20 is provided. Attach to part 26.
In this embodiment, the side frame 20 is provided with the hole 25 and the locking part 26 for attaching the chest resin spring 30, but instead of providing the hole 25 and the locking part 26, the side frame 20 A retainer for attaching the end portion of the chest resin spring 30 may be provided on the rear surface of the rear flange portion 23.

Instead of the chest resin spring 30, a chest resin spring 70 having a spring portion 71 shown in FIG. 10 may be used.
The spring portion 71 is formed of a substantially band-shaped corrugated plate body including a position corresponding to the pair of scapulas 53 of the occupant and a position corresponding to the ninth thoracic vertebra 52, and the seat upper end portion of the spring portion 71 at the center in the seat width direction. A hole portion 75 is formed at a position slightly lower than the above. The hole portion 75 is provided at a position above the seat that does not need to be supported by the spring portion 71 from the position corresponding to the ninth thoracic vertebra 52. By providing the hole portion 75, the weight of the spring portion 71 can be reduced. It is illustrated.
The center of the spring portion 71 in the seat width direction protrudes downward in the seat, and the portion of the hole 75 below the seat forms the ninth thoracic vertebra support portion 72. The portions of the ninth thoracic vertebra support portion 72 on both sides in the seat width direction form a pair of scapula support portions 73.
Between the upper end of the seat of the hole 75 and the upper end of the seat of the spring portion 71, a connecting portion that connects the pair of scapula support portions 73 to each other is configured.

Further, instead of the chest resin spring 30, a chest resin spring 80 including a spring portion 81 shown in FIG. 11 may be used.
The spring portion 81 is formed of a substantially band-shaped corrugated body including a position corresponding to the pair of scapulas 53 of the occupant and a position corresponding to the ninth thoracic vertebra 52, and the upper end at the center in the seat width direction has a U-shape. It has a notched shape. As described above, since the position that does not need to be supported by the spring portion 81 is cut away from the position corresponding to the ninth thoracic vertebra 52, the weight of the spring portion 81 is reduced. .
The lower portion of the seat in the center of the spring portion 81 in the seat width direction forms a ninth thoracic vertebra support portion 82, and the lower portion of the seat forms a ninth thoracic vertebra support portion 82. The portions on both sides in the width direction form a pair of scapula support portions 83.

Instead of the chest resin spring 30, a chest resin spring 90 including the spring portion 91 shown in FIG. 12 may be used.
The spring portion 91 is formed of a substantially elliptical corrugated plate including a position corresponding to the pair of scapulas 53 of the occupant and a position corresponding to the ninth thoracic vertebra 52.
A hole portion 95 is formed at a position slightly lower than the sheet upper end portion of the spring portion 91 at the center in the sheet width direction. The center of the spring portion 91 in the seat width direction protrudes downward in the seat, and the portion of the hole 95 below the seat forms the ninth thoracic vertebra support portion 92.

A pair of hole portions 96 are formed at positions slightly higher than the sheet lower end portions on both sides in the sheet width direction of the ninth thoracic vertebra support portion 92. On the both sides in the sheet width direction of the ninth thoracic vertebra support portion 92, portions above the hole portion 96 form a pair of scapula support portions 93.
The hole portions 95 and 96 are provided at positions that do not need to be supported by the spring portion 91. By providing the hole portions 95 and 96, the weight of the spring portion 91 is reduced.
Between the seat upper end of the hole portion 95 and the seat upper end of the spring portion 91, a connecting portion that connects the pair of scapula support portions 93 to each other is configured. Further, between the lower end of the seat of the hole portion 96 and the lower end of the seat of the spring portion 91, a connection for connecting the left and right ends of the lower end of the seat supporting portion that supports the chest portion of the spring portion 91 and the ninth thoracic vertebra support portion 92. Part.

The waist resin spring 40 is made of a resin plate, has a high upper end corresponding to the pair of waist square muscles 63 shown in FIG. 13, and is slightly below the position sandwiched between the pair of waist square muscles 63. The spring part 41 formed so that the lower end of the position corresponding to the sacrum 62 is lowered, and the both sides of the spring part 41 are positioned at the heights near the center of the highest position and the lowest position of the spring part 41. And an attachment portion 44 extending toward the front.
As shown in FIG. 8, the spring portion 41 is provided at the center of the spring portion 41 in the seat width direction, and is provided on the left and right sides of the sacrum support portion 42 that supports the sacrum 62 of the occupant, and on the left and right sides of the occupant. And a pair of hippocampus muscle support portions 43 that support the hippocampus muscle 63.

A pair of slits 45 is provided along the inclined side connecting the upper end 43u of the lower back muscle support portion 43 and the upper end 40u of the lower back resin spring 40 near the inner side in the seat width direction below the lower back muscle support portion 43. ing. Further, a pair of slits 46 are provided near the outer side in the seat width direction below the seat of the lower back muscle support portion 43 along an inclined side connecting the upper end 43 u of the back muscle support portion 43 and the upper end 44 u of the attachment portion 44. It has been. Since the slits 45 and 46 are provided, the weight of the spring portion 41 can be reduced.
These slits 45 and 46 are formed such that the length in the vertical direction of the sheet is larger than the width of the mounting portion 44 in the vertical direction of the sheet, and the weight can be further reduced.
The configuration of the spring portion 41 is the same as the configuration of the spring portion 31 as shown in FIG. 8 except that the configuration is a plate shape instead of a corrugated plate and the slits 45 and 46 are provided. Is omitted. In addition, you may comprise the spring part 41 from a corrugated plate.

  As shown in FIGS. 6 and 7, the attachment portion 44 is composed of a plate-like band-shaped portion, and is an inner end flange portion contact portion 44 a that is bent along the inner surface of the inner end flange portion 24 of the side frame 20. A rear flange portion contact portion 44b that contacts the inner surface of the rear flange portion 23, a bent portion 44c that bends along the inner surface of the bent portion 23c between the rear flange portion 23 and the side portion 21, and a side portion. 21 is provided with a side abutting portion 44d that abuts on the inner surface, and a locking piece 44e inserted into the locking portion 27 is formed at the tip.

The locking piece 44e is formed so that a thin rod-like body bends vertically downward from the upper end of the mounting portion 44. The locking piece 44e fixes the distal end of the attachment portion 44 to the inner surface of the side frame 20 by inserting the distal end portion of the thin rod-like body into the locking portion 27.
The region from the inner end flange portion abutting portion 44a to the side portion abutting portion 44d of the mounting portion 44 is in contact with the inner surface of the region from the inner end flange portion 24 to the side portion 21 of the side frame 20. Stiffness is improved.

The spring portion 41 is formed thinner than the attachment portion 44 and has a sufficient amount of bending, and the attachment portion 44 is formed thicker than the spring portion 41 so that attachment rigidity is ensured. Yes.
The lumbar resin spring 40 is arranged along the surface constituted by the seat back frame 1 in a normal state other than at the time of a rear collision, and supports a portion from the occupant's lower back muscle 63 through the iliac to the sacrum 62. Is possible.
Since the waist resin spring 40 is formed of a plate-like body, the amount of bending is smaller than that of the chest resin spring 30.

In the present embodiment, when a force is applied to the occupant against the seat back S1 in the F direction of FIGS. 4 and 7 at the time of a rear collision, the spring portion 31 of the chest resin spring 30 and the spring portion 41 of the waist resin spring 40 are applied. 4 can be bent to 31 'and 41' in FIG. 4 and FIG. 7, and the occupant can enter to positions 31 'and 41'.
In the conventional vehicle seat, as shown in FIG. 14, both end portions of the pressure receiving member 130 are attached to the front side of the rear flange portion 23 of the side frame 20.
At the time of a rear collision, a force in the direction of pressing the occupant against the vehicle seat S is applied, the pressure receiving member 130 is bent, and the occupant enters toward the rear of the vehicle seat S. When the pressure receiving member 130 is bent rearward, as shown in FIG. 14, the pressure receiving member 130 comes into contact with the inner end flange portion 24 of the side frame 20, so that the rear flange portion 23 and the inner end flange portion 24 become an obstacle. Thus, a sufficient amount of bending is not ensured.

  On the other hand, the chest resin spring 30 of the present embodiment passes through the hole 25 of the side frame 20, and the overall length on the spring portion 31 side is located behind the surface on which the rear flange portion 23 of the side frame 20 is provided. . Therefore, the chest resin spring 30 does not abut against the inner end flange portion 24, and the rear flange portion 23 and the inner end flange portion 24 do not become an obstacle, so that the occupant is located behind the vehicle seat S at the time of a rear collision. Even when approaching, a sufficient amount of deflection is ensured as shown in FIG. As a result, in the chest resin spring 30 of the present embodiment, the occupant's entry amount increases by the increase width Δ in FIG.

G Center of gravity GL Straight line L1 Distance L2 Length S Vehicle seat S1 Seat back S2 Seating part S3 Headrest 1 Seat back frame 1a, 2a Cushion pad 1b, 2b Skin material 3a Pad material 3b Skin material 11 Upper frame 12 Lower frame 13 Pillar support Part 14 headrest pillar 20 side frame 21 side part 22 front flange part 23 rear flange part 23c bent part 24 inner end flange parts 25, 75, 95, 96 hole part 26, 27 locking part 26a curved part 26b hole 30, 70 , 80, 90 Chest resin springs 31, 41, 71, 81, 91 Spring portions 31 ', 41' Positions 32, 72, 82, 92 Ninth thoracic vertebra support portions 32c, 33c Centers 30u, 32u, 33u, 34u, 40u, 42u, 43u, 44u Upper end 32l, 33l, 34l, 42l, 43l, 44 l Lower end 33, 73, 83, 93 Scapula support part 34, 44 Attachment part 34a Insertion part 34b, 44c Bending part 34c, 44e Locking piece 40 Lumbar resin spring 42 Sacral support part 43 Lumbar muscle support part 44a Inner end flange Part contact part 44b Rear flange part contact part 44d Side part contact part 45, 46 Slit 52 9th thoracic vertebra 53 Scapula 62 Sacrum 63 Lumbar muscle 130 Pressure receiving member

Claims (8)

A seat back frame having a pair of left and right side frames, and a support member attached between the side frames, capable of supporting an occupant from the rear of the seat and flexing backward from the seat under the load of the occupant. A vehicle seat comprising:
The support member includes a waist support portion that supports a waist portion of the occupant, and both ends in the seat width direction are attached to the side frame,
The lower back support section has a pair of lower back muscle support sections that support the pair of lower back muscles of the occupant from the rear of the seat at two locations across the center in the seat width direction,
The vehicle seat, wherein the lower back muscle support part protrudes above the seat from the upper end of the lower part support part at the center in the seat width direction.   The lumbar support portion includes a sacrum support portion that protrudes below the seat from the lumbar muscle support portion and supports the sacrum of the occupant at the center in the seat width direction. The vehicle seat as described.   3. The vehicle seat according to claim 1, wherein a distance in the seat width direction between the pair of lumbar muscle support portions is greater than a length of the sacrum support portion in the seat width direction. The waist support portion includes attachment portions for attachment to the side frames at both ends of the waist support portion in the seat width direction.
An end of the attachment portion above the seat is positioned below the seat from an end of the lower back muscle support portion above the seat,
4. The vehicle seat according to claim 1, wherein an end of the attachment portion below the seat is positioned above the seat with respect to an end of the sacrum support portion below the seat. 5.   The said attaching part is provided so that it may be settled in the range below the said sheet | seat from the center of the said lumbar muscle support part, and above the center of the said sacrum support part. Vehicle seats.   The mounting portion is provided at the same height as the center of gravity of an inverted triangle that connects the center of the pair of lumbar muscle support portions and the center of the sacrum support portion with a line. The vehicle seat according to any one of 1 to 5.   The vehicle seat according to any one of claims 1 to 6, wherein an end of the waist support portion above the seat is provided below the seat from the center of the waist muscle support portion. The vehicle seat according to any one of claims 1 to 7, wherein an end of the lower back support portion below the seat is provided above the seat with respect to the center of the sacrum support portion.

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