JP6726563B2 - Seat frame - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat frame, and more particularly, to a seat frame that has a simple structure and can improve passenger protection performance.

A seat belt is used as a safety device for protecting an occupant in a vehicle collision. There is known a seat frame having improved occupant protection performance by mitigating an impact applied to the occupant via a shoulder belt of the seat belt that restrains the occupant's upper body (Patent Document 1).

The back frame of the seat frame of Patent Document 1 is composed of a lower structure and an upper structure. The upper structure is constructed by fixing both ends of the arcuate member to a torsion bar extending left and right. A first side upright and a second side upright are respectively provided on the left and right of the lower structure, and the first end of the torsion bar is non-rotatably connected to the first side upright and the second end of the torsion bar is provided. Is pivotally connected to the second upright. When a load exceeding a predetermined value is input to the upper structure via the shoulder belt pulled out from the upper structure, the upper structure leans forward due to the twisting of the torsion bar, and is applied to the occupant via the shoulder belt. Relieves shock.

JP 9-24756 A

However, there is a demand for improving the occupant protection performance with a simpler configuration than the above-mentioned conventional techniques.

The present invention has been made to meet the above-described demands, and an object of the present invention is to provide a seat frame that can improve the occupant protection performance with a simple structure.

Means for Solving the Problems and Effects of the Invention

According to the seat frame of the first aspect, the seat back is arranged at the rear end of the cushion frame, and the inclination angle of the back frame with respect to the cushion frame is adjusted by the reclining device. The back frame is formed by connecting upper end sides of a first frame and a second frame, which are arranged at a predetermined interval to the left and right, with an upper frame. The lower end of the first frame is swingably supported by the first swing shaft at the rear end of the cushion frame, and the upper end of the third frame is swingably supported by the second swing shaft at the lower end of the second frame. .. The lower end of the third frame is swingably supported by the rear end of the cushion frame by the third swing shaft whose axis coincides with the first swing shaft, and the third swing shaft is centered by the lock device of the reclining device. The rocking of the third frame is disabled. The shoulder belt from the retractor around which the shoulder belt that restrains the upper body of the occupant is wound is pulled out from the pull-out portion provided at the upper end of the second frame.

When a load is input to the second frame via the shoulder belt and the pull-out portion, the heights of the first swing shaft and the second swing shaft are different, so that the resistance force due to the rigidity of the back frame works and a predetermined value is obtained. Up to the load of 1, the forward leaning of the second frame about the second swing axis and the forward leaning of the first frame about the first swing axis are prevented. When the load exerted through the shoulder belt exceeds a predetermined value, the back frame is plastically deformed, the first frame is tilted forward about the first swing axis, and the second frame is centered on the second swing axis. Lean forward. As a result, when the load through the shoulder belt is equal to or greater than a predetermined value, the impact applied to the occupant through the shoulder belt can be mitigated, and the occupant protection performance can be improved.

Using the first swing shaft, which is a shaft for changing the inclination angle of the back frame with respect to the cushion frame, the load is increased by utilizing the difference in height between the first swing shaft and the second swing shaft. Since the back frame is tilted forward when the value exceeds a predetermined value, there is an effect that the occupant protection performance can be improved with a simple structure.

Lower frame Bas Kkufuremu the first end is integrated with the second swing axis, the second end is fixed to the first frame. When tilting the first frame and the second frame, whose upper ends are connected to each other by the upper frame, about the first swing shaft and the second swing shaft having different heights, respectively, lower ends of the first frame and the second frame The side shifts greatly in the front-back direction. Therefore, the rigidity of the lower frame that connects the lower end sides of the first frame and the second frame greatly contributes to the resistance force that prevents the back frame from leaning forward. The rigidity of the lower frame makes it easy to set a predetermined value for the load at which the back frame begins to tilt forward.

Further, since the second swing shaft with which the first end of the lower frame is integrated is rotatable with respect to the second frame and the third frame, it is possible to prevent the lower frame from being twisted when the back frame is tilted forward. Therefore, the predetermined value of the load at which the back frame starts to lean forward can be set by ignoring the torsional rigidity of the lower frame. These results, while simplifying the structure, there is an effect of easily setting a predetermined value of the load back frame begins tilted forward.

According to the seat frame according to claim 2, wherein, the third frame, so comprises a stopper for regulating a predetermined amount or more of the swing of the second frame about the second pivot shaft, in addition to the effect of claim 1 The effect of preventing the back frame from leaning forward too much and improving the occupant protection performance is obtained.

It is a perspective view of the seat frame in one embodiment of the present invention. It is a front view of a back frame. FIG. 3 is a cross-sectional view of the back frame taken along the line III-III in FIG. 2. FIG. 4 is a cross-sectional view of the back frame taken along the line IV-IV in FIG. 3. It is a perspective view of a seat frame when the load more than a predetermined value is inputted.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, a seat frame 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of a seat frame 1 according to an embodiment of the present invention.

As shown in FIG. 1, the seat frame 1 is a vehicle seat frame mounted in an automobile or the like. The seat frame 1 includes a cushion frame 2, a back frame 3 arranged at a rear end of the cushion frame 2, a reclining device 4 for adjusting an inclination angle of the back frame 3 with respect to the cushion frame 2, and a shoulder belt 6 of a seat belt. And a retractor 5 that is wound.

The cushion frame 2 is a frame of a seat cushion of a vehicle seat on which an occupant sits, and is mainly made of steel. A cushion pad (not shown) made of foamed synthetic resin such as flexible polyurethane foam having elasticity is supported by the cushion frame 2, and the cushion pad is covered with a cover (not shown) made of fabric, synthetic leather, or leather. A seat cushion is formed over the cover.

The back frame 3 is a frame of a seat back that serves as a backrest of an occupant of the vehicle seat, and is mainly made of steel. A back pad (not shown) made of foamed synthetic resin such as elastic soft polyurethane foam is supported by the back frame 3, and the back pad is covered by a cover (not shown) made of fabric, synthetic leather or leather. A seat back is formed over the cover.

The rear end of the cushion frame 2 and the lower end of the back frame 3 are swingably connected by a first swing shaft 16 and a third swing shaft 19. The reclining device 4 is a portion connecting the cushion frame 2 and the back frame 3. The first swing shaft 16 and the third swing shaft 19 are also a part of the reclining device 4. The reclining device 4 includes a lock device 4 a that locks the inclination angle of the back frame 3 with respect to the cushion frame 2.

The lock device 4a is switched between locked and unlocked by an occupant operating a lever or a switch (not shown). The lock device 4a disables the swing of the third frame 13 of the back frame 3 about the third swing shaft 19 (locks the tilt angle) when the lever or the switch is not operated by the occupant. .. On the other hand, the lock device 4a enables the third frame 13 to swing around the third swing shaft 19 (unlocks the tilt angle) when the occupant is operating the lever or the switch.

The retractor 5 is attached to the back frame 3. The shoulder belt 6 pulled out from the retractor 5 restrains the upper body of the occupant. The shoulder belt 6 is pulled out to the entire surface of the back frame 3 from around the shoulders of the occupant via the pull-out portions 17 provided at the upper ends on the left and right sides of the back frame 3, and is slanted from the shoulders of the occupant to the waist.

The retractor 5 locks the shoulder belt 6 or winds the shoulder belt 6 when the vehicle suddenly decelerates due to a vehicle collision or the like, and prevents the shoulder belt 6 from being further pulled out. The retractor 5 in the present embodiment does not have the function of a force limiter that gradually feeds the shoulder belt 6 when a load (tensile force) greater than or equal to a predetermined value is input to the shoulder belt 6.

Next, the back frame 3 will be further described with reference to FIG. 2 in addition to FIG. 1. FIG. 2 is a front view of the back frame 3. As shown in FIGS. 1 and 2, the back frame 3 includes a first frame 11 and a second frame 12, which are arranged at a predetermined interval on the left and right, and a third frame which connects the second frame 12 and the cushion frame 2. The frame 13 includes an upper frame 14 that connects the upper ends of the first frame 11 and the second frame 12 to each other, and a lower frame 15 that connects the lower ends of the first frame 11 and the second frame 12 to each other.

The first frame 11 is a portion arranged on the right side of the seat frame 1, and the lower end thereof is swingably supported by the first swing shaft 16 on the rear end of the cushion frame 2. The first frame 11 includes a pipe portion 11a and a plate portion 11b welded to the pipe portion 11a. The plate portion 11b is not limited to being welded to the pipe portion 11a, and it is naturally possible to join the plate portion 11b to the pipe portion 11a with bolts, rivets or the like.

The pipe portion 11a is a hollow pipe and constitutes an upper portion and a central portion of the first frame 11. The plate portion 11b is a member formed by bending a plate material, and constitutes a central portion and a lower portion of the first frame 11. The plate portion 11b is formed so as to gradually project forward from the upper end to the lower end of the pipe portion 11a. Accordingly, the back pad can be prevented from shifting to the left and right by the plate portion 11b while the back pad is supported from the rear by the pipe portion 11a. That is, since the first frame 11 is formed in conformity with the shape of the back pad, the holding performance of the back pad by the back frame 3 can be ensured.

The second frame 12 is a portion arranged on the left side of the seat frame 1. The second frame 12 has a thickness (horizontal dimension) that is substantially constant in the vertical direction, and a width (front-back dimension) that decreases from the lower end toward the upper end. Since the width of the second frame 12 is formed sufficiently larger than the thickness thereof, the bending rigidity in the front-rear direction is high, and the second frame 12 can be hardly plastically deformed in the front-rear direction.

The lower end of the second frame 12 is swingably supported by the upper end of the third frame 13 by the second swing shaft 18. The second frame 12 is provided at its upper end with a pull-out portion 17 from which the shoulder belt 6 is pulled out. The drawer portion 17 is configured by a pair of L-shaped metal fittings each having one end fixed to the upper end of the second frame 12 with the other ends facing each other.

The lower end of the third frame 13 is swingably supported by the third swing shaft 19 at the rear end of the cushion frame 2. The axis of the third swing shaft 19 coincides with that of the first swing shaft 16. The second swing shaft 18 is located above the first swing shaft 16 and the third swing shaft 19.

The upper frame 14 is a hollow pipe, and the first end 14 a penetrates the upper end of the second frame 12 and is rotatably supported with respect to the second frame 12. The second end 14b of the upper frame 14 is integrally formed with the upper end of the pipe portion 11a.

The lower frame 15 is a hollow pipe, and the first end 15a is welded to and integrated with the second swing shaft 18. The second end 15b of the lower frame 15 is integrally formed with the lower end of the pipe portion 11a. The first end 15a of the lower frame 15 is not limited to being welded to the second swing shaft 18, but the first end 15a of the lower frame 15 and the second swing shaft 18 are joined by bolts, rivets, or the like. Of course it is possible.

The pipe portion 11a of the first frame 11, the upper frame 14, and the lower frame 15 are formed by bending one pipe. The rigidity of the pipe portion 11a, the upper frame 14, and the lower frame 15 is set to be lower than the rigidity of the plate portion 11b of the first frame 11, the second frame 12, and the third frame 13. When a predetermined load is input to the back frame 3, the pipe portion 11a, the upper frame 14 and the lower frame 15 are mainly plastically deformed.

Next, details of the back frame 3 will be described with reference to FIGS. 3 and 4. 3 is a sectional view of the back frame 3 taken along the line III-III of FIG. 2, and FIG. 4 is a sectional view of the back frame 3 taken along the line IV-IV of FIG.

As shown in FIG. 3, the second swing shaft 18 integrated with the first end 15a (see FIG. 4) of the lower frame 15 is disposed in the front-back direction of the second frame 12 and the third frame 13 (left and right in FIG. 3). Direction) Support each other behind the center. As a result, the second frame 12 and the third frame 13 project in front of the lower frame 15 (on the right side in FIG. 3), so that the back pad is displaced from side to side while supporting the back pad from the rear by the lower frame 15. Can be prevented by the second frame 12 and the third frame 13. That is, since the second frame 12 and the third frame 13 are formed in accordance with the shape of the back pad, the back pad holding performance of the back frame 3 can be ensured.

The third frame 13 is a portion formed by bending a plate material, and has ribs 13a whose edges are bent inward (from the first frame 11 side) from the peripheral edge excluding the upper edge. As a result, when the second frame 12 is supported by the third frame 13 by the second swing shaft 18, the second frame 12 is located between the front and rear ribs 13a. Therefore, when the second frame 12 is swung with respect to the third frame 13 about the second swing shaft 18, the second frame 12 swings about the second swing shaft 18 by a predetermined amount or more. It is regulated by the rib 13a (stopper).

As shown in FIG. 4, the second swing shaft 18 is a solid member and has a higher rigidity than the lower frame 15. The second swing shaft 18 penetrates through the second frame 12 and the third frame 13 and is rotatable with respect to the second frame 12 and the third frame 13.

The second frame 12 is a hollow member in which the edges of two plate materials facing each other are bent, and the bent edges are overlapped with each other and joined by welding, bolts, or rivets. The plate thickness of the plate member of the third frame 13 is set sufficiently larger than the plate thickness of the plate member of the second frame 12 and the wall thickness of the lower frame 15. That is, the rigidity and strength of the third frame 13 are set to be higher than the rigidity and strength of the second frame 12 and the lower frame 15.

Next, the function of the seat frame 1 will be described with reference to FIG. FIG. 5 is a perspective view of the seat frame 1 when a load of a predetermined value or more is input. In FIG. 5, the back frame 3 before a load of a predetermined value or more is input (the state of FIG. 1) is illustrated by a chain double-dashed line. In FIG. 5, the retractor 5 and the shoulder belt 6 from the retractor 5 to the pull-out portion 17 are omitted.

When the occupant seated on the vehicle seat using the seat frame 1 is wearing the shoulder belt 6, the retractor 5 prevents the shoulder belt 6 from being further pulled out when the vehicle suddenly decelerates due to a vehicle collision or the like. .. As the vehicle decelerates more rapidly, the impact applied to the occupant by the shoulder belt 6 increases, and the load input from the occupant to the upper end of the second frame 12 via the shoulder belt 6 and the pullout portion 17 increases.

Although the first frame 11 can swing about the first swing shaft 16, the third frame 13 can swing about the third swing shaft 19 whose axis coincides with that of the first swing shaft 16. The rocking is disabled by the lock device 4a. Therefore, even if a load is input to the upper end of the second frame 12, it is possible to prevent the back frame 3 from tilting forward around the first swing shaft 16 and the third swing shaft 19 (the shaft of the reclining device 4). ..

The first frame 11 can be swung about the first swing shaft 16, and the second frame 12 can be swung about the second swing shaft 18. 16 and the second swing shaft 18 have different heights (the first swing shaft 16 and the second swing shaft 18 do not have the same axial center). Therefore, until the load input to the upper end of the second frame 12 reaches a predetermined value due to the resistance force exerted by the rigidity of the back frame 3, the forward tilting of the first frame 11 around the first swing shaft 16 is performed. Then, the forward tilting of the second frame 12 about the second swing shaft 18 is prevented.

When the load input to the upper end of the second frame 12 via the shoulder belt 6 becomes a predetermined value (for example, 2500N) or more, the lower frame 15, the upper frame 14, and the pipe portion 11a of the back frame 3 are mainly plastically deformed. The first frame 11 tilts forward around the first swing shaft 16, and the second frame 12 tilts forward around the second swing shaft 18. As a result, when the load from the occupant through the shoulder belt 6 is greater than or equal to a predetermined value, the energy related to the impact applied from the shoulder belt 6 to the occupant is absorbed by the plastic deformation of the back frame 3 and the energy is absorbed in front of the back frame 3. Consumed due to inclination. As a result, the impact applied from the shoulder belt 6 to the occupant can be mitigated, and the occupant protection performance can be improved.

The seat frame 1 uses the first swing shaft 16 which is one side of the shaft (the shaft of the reclining device 4) for changing the inclination angle of the back frame 3 with respect to the cushion frame 2, while using the first swing shaft 16 and By utilizing the difference in height of the second swing shaft 18, the back frame 3 is tilted forward when the load applied via the shoulder belt 6 exceeds a predetermined value. As a result, the occupant protection performance can be improved with a simple structure.

When the load applied through the shoulder belt 6 exceeds a predetermined value, the first frame 11 rotates about the first swing shaft 16 which is the shaft of the reclining device 4, so that the back frame 3 is tilted forward as a whole. Can be made. The shorter the distance between the second swing shaft 18 and the third swing shaft 19, the more the back frame 3 can be tilted forward.

By tilting almost the entire back frame 3 forward, it is possible to prevent a gap from being formed between the upper body of the occupant leaning forward and the seat back (back frame 3), and the upper body moves backward due to the recoil of forward leaning. It is possible to reduce the collision between the upper body and the seat back (back frame 3) when the user leans back to the back.

When the back frame is divided into upper and lower parts and only the upper end side of the back frame tilts forward as in the related art (for example, Patent Document 1), the load from the back frame is applied to a part of the upper body of the occupant. There is a risk of concentration. In the present embodiment, by tilting substantially the entire back frame 3, it is possible to suppress the concentration of the load on the occupant from the back frame 3 that tilts forward.

When the back frame 3 is tilted forward about the first swing shaft 16 and the second swing shaft 18 having different heights, the lower frame 15 that connects the lower end sides of the first frame 11 and the second frame 12 to each other is used. It is bent and deformed. In particular, when the back frame 3 is tilted forward, the lower ends of the first frame 11 and the second frame 12 are largely displaced in the front-rear direction, so that the rigidity of the lower frame 15 is increased by the resistance force for preventing the back frame 3 from tilting forward. Make a big contribution. By appropriately setting the rigidity of the lower frame 15, it is possible to easily set a predetermined value of the load at which the back frame 3 starts to lean forward.

Further, since the second swing shaft 18 integrated with the first end 15a of the lower frame 15 is rotatable with respect to the second frame 12 and the third frame 13, the lower frame 15 is twisted when the back frame 3 is tilted forward. You can avoid it. Therefore, the predetermined value of the load at which the back frame 3 starts to tilt forward can be set by ignoring the torsional rigidity of the lower frame 15. As a result, while simplifying the structure, it is possible to easily set the predetermined value of the load at which the back frame 3 starts to tilt forward.

Since the first end 14a of the upper frame 14 is rotatable with respect to the second frame 12, it is possible to prevent the upper frame 14 from being twisted when the back frame 3 is tilted forward. Therefore, the predetermined value of the load at which the back frame 3 starts to tilt forward can be set by ignoring the torsional rigidity of the upper frame 14. As a result, while simplifying the structure, it is possible to easily set the predetermined value of the load at which the back frame 3 starts to tilt forward.

When the back frame 3 is tilted forward about the first swing shaft 16 and the second swing shaft 18 having different heights, the upper end of the second frame 12 is lower than the upper end of the first frame 11. Therefore, when the back frame 3 is tilted forward, the upper frame 14 and the pipe portion 11a of the first frame 11, which have relatively low rigidity, are bent and deformed.

The parts mainly deformed when the back frame 3 is tilted forward are the lower frame 15, the upper frame 14, and the pipe part 11a, which are all made of the same pipe. Further, when the back frame 3 is tilted forward, the lower frame 15, the upper frame 14, and the pipe portion 11a are mainly bent and deformed. Therefore, the predetermined value of the load at which the back frame 3 starts to lean forward can be set based on the bending rigidity of the lower frame 15, the upper frame 14 and the pipes forming the pipe part 11a without considering the torsional rigidity of each part. As a result, while simplifying the structure, it is possible to easily set the predetermined value of the load at which the back frame 3 starts to tilt forward.

Since the ribs 13a regulate the swinging of the second frame 12 about the second swinging shaft 18 by a predetermined amount or more, it is possible to prevent the back frame 3 from leaning forward too much and improve the passenger's protection performance. Further, since the rigidity and strength of the third frame 13 are set to be higher than the rigidity and strength of the second frame 12 and the lower frame 15, the rib 13a is plastically deformed even when the second frame 12 contacts the rib 13a. Can be prevented. The position of the rib 13a is set such that the upper end of the second frame 12 moves forward by about 300 mm due to the plastic deformation of the back frame 3.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various improvements and modifications are possible without departing from the spirit of the present invention. It can be easily guessed. For example, the shapes of the cushion frame 2, the first frame 11, the second frame 12, the third frame 13, the upper frame 14, the lower frame 15 and the like are examples, and it is natural that various shapes are adopted.

In the above embodiment, the seat frame 1 in which the first frame 11 is located on the right side of the back frame 3 and the second frame 12 and the third frame 13 are located on the left side of the back frame 3 has been described, but the present invention is not limited to this. Instead, it is naturally possible to reverse the left and right of the seat frame 1.

In the above embodiment, the case where the cushion frame 2 and the back frame 3 are mainly made of steel has been described. However, the present invention is not limited to this, and the cushion frame 2 and the back frame may be made of metal other than steel or synthetic resin. Of course, it is possible to use it for 3.

In the above embodiment, the case where the first end 15a of the lower frame 15 and the second swing shaft 18 are integrated has been described, but the present invention is not limited to this. It is naturally possible to fix the first end 15a of the lower frame 15 directly to the second frame 12 and provide the second swing shaft 18 at a portion different from the portion where the first end 15a is fixed. It is also possible to omit the lower frame 15.

Although the case where the first end 15a of the lower frame 15 and the second swing shaft 18 are welded and integrated with each other has been described in the above embodiment, the present invention is not limited to this, and the lower frame and the second frame are not necessarily limited to this. It is of course possible to integrally form the swing shaft and use the first end of the lower frame as the second swing shaft (integrate the first end and the second swing shaft of the lower frame).

In the above embodiment, the case where the second swing shaft 18 provided at the first end 15a of the lower frame 15 is rotatable with respect to the second frame 12 and the third frame 13 has been described, but the present invention is not limited to this. However, it is of course possible to fix the second swing shaft 18 to the second frame 12 or the third frame 13. Further, the first end 14a of the upper frame 14 is not limited to being rotatable with respect to the second frame 12, and it is naturally possible to fix the first end 14a of the upper frame 14 to the second frame 12.

In the above-described embodiment, the retractor 5 that does not have the function of the force limiter that gradually sends out the shoulder belt 6 when the load of a predetermined value or more is input to the shoulder belt 6 has been described, but the present invention is not limited to this. Instead, it is naturally possible to use a retractor having the function of a force limiter. In this case, it is preferable that the upper body of the occupant be tilted forward by about 300 mm in total by feeding the belt by the retractor and tilting the back frame 3 forward.

1 Seat Frame 2 Cushion Frame 3 Back Frame 4 Reclining Device 4a Lock Device 5 Retractor 11 1st Frame 12 2nd Frame 13 3rd Frame 13a Rib (Stopper)
14 Upper Frame 15 Lower Frame 16 First Swing Shaft 17 Drawout 18 Second Swing Shaft 19 Third Swing Shaft

Claims (2)

Cushion frame,
A back frame arranged at the rear end of the cushion frame,
A reclining device for adjusting the inclination angle of the back frame with respect to the cushion frame,
A retractor around which a shoulder belt for restraining the upper body of the occupant is wound,
The back frame is
A first frame and a second frame that are arranged at a predetermined interval on the left and right,
An upper frame that connects upper end sides of the first frame and the second frame,
A first swing shaft that swingably supports the lower end of the first frame to the rear end of the cushion frame;
An upper end is swingably supported by a lower end of the second frame by a second swing shaft, and a lower end is a rear end of the cushion frame by a third swing shaft whose axis coincides with the first swing shaft. A third frame swingably supported ;
A lower frame connecting the lower ends of the first frame and the second frame to each other ,
The second frame is provided at its upper end with a pull-out portion from which the shoulder belt is pulled out from the retractor,
The reclining device includes a locking device to disable the swing of the third frame around the third pivot shaft,
A first end of the lower frame is integrated with the second swing shaft, and a second end of the lower frame is fixed to the first frame;
The seat frame , wherein the second swing shaft is rotatable with respect to the second frame and the third frame. The third frame, the seat frame according to claim 1, further comprising a stopper for regulating a predetermined amount or more of the swinging of the second frame around said second pivot shaft.

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