JP5521160B2 - Shock absorbing device for shock absorbing sheet for vehicle - Google Patents

Description

  The present invention relates to an impact absorbing device for an impact absorbing sheet for a vehicle that protects a seated person from an impact by absorbing and reducing impact energy at the time of a vehicle collision such as a collision from the rear or a collision from the front.

  In a vehicle seat such as an automobile, it is necessary to protect a seated person in a collision from the rear of the automobile (rear collision; rear collision) or a forward collision (front collision; front collision). An impact absorbing device in which a weak portion, a so-called strength weakened portion, is provided in a part or a reclining unit (recliner) or the like is incorporated in a vehicle seat such as an automobile. A vehicle seat with a built-in shock absorbing device is called a vehicle shock absorbing seat. If excessive impact energy is applied to the seat (seat back) due to a collision (rear impact, front impact), the strength weakened part is deformed. The seat back is forcibly tilted backward to absorb impact energy, reducing the impact on the head and neck of the occupant and protecting the occupant from impact during a collision (rear and front collisions). doing.

  For example, as an impact absorbing device for a vehicle seat, for example, in Japanese Patent Application Laid-Open No. 07-132767, a belt-like corrugated reinforcing rib is provided in a part of a seat back frame. In JP 2009-001209 A, a convex portion is projected from one disk member of a pair of opposed disk members that are provided between a seat back frame and a reclining device and swing relative to each other. The disk member is locked in a locking hole. At the time of rear impact, the former causes the meandering part (strength weak part) of the reinforcing rib to buckle and deform, and in the latter, the edge of the locking hole shears the convex part (strength weak part). It absorbs energy and reduces the impact on the seated person's head and neck.

Japanese Patent Laid-Open No. 07-132767 JP 2009-001209 A

  In the configuration described in Japanese Patent Laid-Open No. 07-132767 in which a part of the reinforcing rib (meandering portion) is buckled and deformed to absorb and reduce the impact energy, once the deformation starts once under an impact such as a rear impact, There is a possibility that the deformation resistance is rapidly reduced and the seat back is excessively tilted backward. Excessive backward tilting of the seat back tends to be accompanied by excessive separation of the upper body of the seated person from the seat belt, and thus there is no denying the possibility of causing the seated person to perform secondary operations such as rebound.

In the configuration described in Japanese Patent Application Laid-Open No. 2009-001209 in which the convex portion is sheared at the edge of the locking hole to absorb impact energy, a plurality of, for example, a pair of disk members that opposes the three convex portions and the three locking holes. Are formed 120 ° apart from each other, and the convex portions are respectively locked in the corresponding locking holes to provide three sets of strength weakened portions including the convex portions and the locking holes, which complicates the configuration of the shock absorbing device. .
In addition, the disc member with protrusions and locking holes has the reclining shaft, which is the center of swinging of the seat back, as the center of rotation. In order to be able to secure a sufficient amount of backward inclination of the seat back, it is necessary to lock the convex portion in the locking hole at a position sufficiently away from the rotation center (reclining shaft). is there. Accordingly, it is inevitable to increase the diameter of the disk member in which the convex portions and the locking holes are formed, and it is difficult to reduce the weight and size of the shock absorbing device. Furthermore, increasing the diameter of the impact absorbing device tends to have an adverse effect on the size of the sheet and the design of the sheet itself, which is not preferable in this respect.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an impact absorbing device for a vehicle impact absorbing sheet having a simple configuration capable of sufficiently absorbing impact energy at the time of a collision.

  According to the first aspect of the present invention, the bracket fixed to one of the seat back frame and the seat cushion frame, the base plate fixed to the other, and the weakened strength portion that easily bends and deforms under a bending moment. And a shock absorbing plate mounted with a mounting pin between the bracket and the base plate, and the base plate is positioned relative to the bracket at one of the front and rear positions with respect to the swing center different from the swing center of the seat back. Arc holes are formed in the bracket and base plate, and corresponding insertion holes are formed in the base plate and bracket, respectively, at the other front and rear free end positions with the seat back swing center as the boundary. Insertion holes are formed at the ends of the shock absorbing plate, and the mounting pins are inserted through the insertion holes at the ends. The shock absorbing plate is inserted between the bracket and base plate arc holes and insertion holes, and the impact force due to the collision is applied to the seat back, and the impact force exceeds the rigidity of the shock absorbing plate. When the shock absorbing plate is bent and deformed as the mounting pin moves in the arc hole, the shock can be absorbed by relatively moving between the bracket and the base plate.

According to the second aspect of the present invention, the shock absorbing plate has, at one end thereof, an extended portion that extends laterally through a weakened strength portion that is easily broken, and the extended portion is adjacent to the arc hole. It is fixed to either the bracket or the base plate at the position.
According to the third aspect of the present invention, the notch is provided in the middle part of the shock absorbing plate to form the weakened part of the middle part.
According to the fourth aspect of the present invention, the bracket is fixed to the seat cushion frame, the base plate is fixed to the seat back frame, and the base plate is relative to the bracket by the connecting shaft that is supported by the bracket and the shaft support hole of the base plate. The connection shaft is pivotally supported by the shaft support hole of the bracket via a bush.
According to the fifth aspect of the present invention, one end of the connecting shaft is welded to the base plate, and the other end is crimped to the washer that covers the connecting shaft.

In the present invention according to claim 1, the strength weakened portion of the shock absorbing plate is bent and deformed by the bending moment to absorb the impact energy at the time of collision, and is not a buckling deformation but a bending deformation. It can absorb impact energy reliably. Therefore, the impact applied to the head and neck of the seated person is reduced, and the seated person can be protected from the impact during the collision.
The impact energy at the time of rear impact can be absorbed only by the impact absorbing plate interposed between the bracket and the base plate, and the configuration of the impact absorbing device can be simplified. Further, since the impact energy is absorbed only by the impact absorbing plate, the energy absorbing characteristics can be freely controlled.
Furthermore, since the amount of backward tilting of the seat back with the connecting shaft as a fulcrum is limited as the range of movement of the mounting pin with respect to the arc hole, it is possible to reliably prevent excessive backward tilting of the seat back when an impact force is applied.
The base plate is swung relative to the bracket around a swing center different from the swing center of the seat back, and the impact-absorbing plate is weakened at a position sufficiently away from the swing center of the seat back. Therefore, the rearward inclination of the seat back can be secured without increasing the size of the base plate and the bracket, and the impact absorbing device can be reduced in weight and size.
In the present invention according to claim 2, since the extension portion is fixed to the bracket or the base plate, relative swinging of the base plate is restricted until the weakened strength portion of the end portion is broken, and the shock absorbing plate Elastic deformation of the weakened strength portion of the intermediate portion is suppressed. Therefore, it is possible to appropriately control the bending deformation of the weakened strength portion in the middle portion of the shock absorbing plate, and it is possible to absorb the shock energy at the time of collision more reliably.
In the present invention according to claim 3, the weakened portion of the middle portion is formed by the notch, and the weakened portion of the strength can be easily formed by press working or the like.
In the present invention according to claim 4, since the connection shaft is pivotally supported by the shaft support hole of the bracket via the bush, smooth rotation of the connection shaft is ensured.
In the present invention according to claim 5, since the other end of the connecting shaft that is a free end is caulked with a washer interposed, excessive resistance is prevented from being applied by caulking, and the connecting shaft is smoothly rotated with respect to the bracket. Secured. In addition, since one end of the connecting shaft is welded to the base plate and the connecting shaft and the base plate are integrated, and the end (free end) of the connecting shaft is crimped on the bracket side, a space for storing the crimping portion can be easily obtained.

1 shows a schematic side view of an impact absorbing sheet for a vehicle in which an impact absorbing device according to an embodiment of the present invention is incorporated. 1 is an exploded perspective view of an impact absorbing device according to an embodiment of the present invention. (A-1) and (A-2) are a front view and a right side view of the bracket, and (B-1) and (B-2) are a front view and a right side view of the base plate, respectively. (A-1) and (A-2) are a front view and a right side view of the shock absorbing plate, and (B-1) and (B-2) are a front view and a right side view of the shock absorbing plate with the notch shape changed, (C-1) and (C-2) are respectively a front view and a right side view of an impact absorbing plate with an extension. (A-1) and (A-2) are a front view and a right side view of the connecting shaft, and (B-1) and (B-2) are a front view and a left side view of the mounting pin, respectively. (A) (B) shows the front view of the impact-absorbing device at the time of normal collision and rear collision, respectively. (A) (B) shows the front view at the time of the normal time of the impact-absorbing device in which an impact-absorbing plate has an extension part, and a rear collision, respectively. It is a schematic diagram schematically showing the relationship between the pressing force (impact load) acting on the shock absorbing plate and deformation, (A) is only the extension portion fixed to the bracket, and (B) is the extension portion. (C) shows the case where an impact load is received by the impact absorbing plate with the extension portion.

  For example, the bracket is fixed to the seat cushion frame and the base plate is fixed to the seat back frame, and the base plate is attached to the bracket so as to be able to swing relative to the bracket by a connecting shaft. An impact-absorbing plate having a weakened strength portion that easily bends and deforms under a bending moment is attached between a bracket and a base plate with a mounting pin. The base plate is attached so as to be able to swing relative to the bracket at either one of the front and rear positions with respect to the swing center different from the swing center of the seat back. Arc holes are formed in the bracket and base plate at the other free end side position before and after the swing center of the seat back, and corresponding insertion holes are formed in the base plate and bracket, respectively. The mounting pins are respectively formed at the end portions of the plate, and the mounting pins are respectively inserted into the bracket, the arc holes and the insertion holes of the base plate through the end insertion holes, and the shock absorbing plate is interposed between the bracket and the base plate. When the impact force due to the collision is applied to the seat back and the impact force exceeds the rigidity of the impact absorbing plate, the bracket and base plate are bent due to the bending deformation of the impact absorbing plate accompanying the movement of the mounting pin in the arc hole. The impact is absorbed by relatively moving between them.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic side view of a vehicle impact absorbing sheet in which an impact absorbing device according to an embodiment of the present invention is incorporated, and FIG. 2 is an exploded perspective view of the impact absorbing device according to an embodiment of the present invention.

  As shown in FIG. 1, the vehicle seat 10 includes a seat cushion 12 and a seat back 14 that is swingable back and forth at the rear end of the seat cushion. The shock absorbing device 20 according to one embodiment of the present invention is incorporated in the connecting portion. In FIG. 1, in order to prevent the drawing from becoming complicated, only the impact absorbing device is illustrated, and members such as a side frame and a recliner (reclining unit) are omitted.

  As shown in FIG. 2, the impact absorbing device 20 includes a bracket 22 fixed to one of a seat back frame and a seat cushion frame, a base plate 24 fixed to the other, and an impact absorbing unit disposed between the bracket and the base plate. The shock absorbing plate is configured so as to be easily bent and deformed under a bending moment and the position thereof can be easily specified. Is formed.

  In the embodiment, the bracket 22 is embodied as a member fixed to the seat cushion frame (not shown) side, and the base plate 24 is embodied as a member fixed to the seat back frame 14a side. Then, by fixing the bracket 22 and the base plate 24 to the corresponding members, the seat back 14 can swing back and forth with respect to the seat cushion 12 with the recliner shaft (recliner shaft) 16 as the swing center. It can be tilted forward or backward.

  The bracket 22 may be formed integrally with the seat cushion frame, and the fixing of the bracket to the seat cushion frame includes an integrally formed form.

  3 and 4 show a front view and a right side view of main members of the shock absorbing device, and (A-1) and (A-2) in FIG. 3 are a front view and a right side view of the bracket, and (B-1). (B-2) is a front view and a right side view of the base plate, and (A-1) and (A-2) in FIG. 4 are a front view and a right side view of the shock absorbing plate, respectively.

  As shown in FIG. 2 and FIG. 3 (A-1) (A-2), the bracket 22 is formed by pressing a steel plate into a shape having a bent edge except in one direction, for example, one side located on the front side of the seat. A loose insertion hole 22a into which the reclining shaft 16 is loosely inserted is provided in the approximate center of the bracket. Then, a shaft support hole 22b for a connecting shaft 28 that connects the bracket 22 and the base plate 24 so as to be relatively swingable is formed on the rear side, for example, with the loose insertion hole 22a (the reclining shaft 16) as a boundary. In addition, an insertion hole 22c and a long hole 22d for the shock absorbing plate 26 are respectively formed on the front side with the loose insertion hole as a boundary. The long hole 22d is an arc hole centered on the shaft support hole 22b. Reference numeral 22e denotes a fixing bolt insertion hole, and the bracket 22 is fixed to the seat cushion frame by fastening of a mounting bolt (not shown) through the insertion hole.

As shown in FIGS. 2 and 3 (B-1) and (B-2), the base plate 24 is formed by, for example, pressing a steel plate into a two-stepped shape, and like the bracket 22, A loose insertion hole 24a into which the reclining shaft 16 is loosely inserted is formed at substantially the center of the base plate, and a shaft support hole 24b is formed at a position corresponding to the shaft support hole 22b of the bracket, and is long at a position corresponding to the insertion hole 22c. An insertion hole 24d is formed at a position corresponding to the hole 24c and the long hole 22d. Here, the long hole 24c is an arc hole centered on the shaft support hole 24b, like the long hole 22d of the bracket.
In addition to the above, the base plate 24 is formed with five holes around the loose insertion hole 24a. However, these holes are for fixing the base plate to the recliner 15, and are not related to the present invention. Detailed description is omitted.

  The depth of the bent edge of the bracket 22 is set to a depth at which the stepped base plate 24 can be substantially accommodated, and the bracket and the base plate are attached to each other so that the bracket covers the base plate.

As shown in FIGS. 2, 4 (A-1) and (A-2), the shock absorbing plate 26 has insertion holes 26c and 26d at its ends, and a V-shaped cut at a substantially middle portion in the longitudinal direction. It is formed into a rectangular shape having a notch 26-1 'by pressing a steel plate. Due to the presence of the notch 26-1 ′, a weakened strength portion 26-1 that is easily bent and deformed under a bending moment and whose position is specified is provided in the shock absorbing plate 26 at substantially the middle in the longitudinal direction.
The insertion hole 26c at one end is aligned with the bracket insertion hole 22c and the arc hole (long hole) 24c of the base plate, and the insertion hole 26d at the other end is an arc hole (long hole) 22d of the bracket and the insertion hole 24d of the base plate. Are formed in alignment with each other.

An example of assembling the shock absorbing device 20 including the bracket 22, the base plate 24, and the shock absorbing plate 26 will be described below.
In the embodiment, the connecting shaft 28 is provided on the rear side of the bracket with the insertion hole 22a of the bracket and the insertion hole 24a of the base plate, that is, on the rear side with the position of the reclining shaft 16 as a boundary. The base plate 24 is connected to the bracket 22 so as to be able to swing relative to the bracket 22 by being inserted into and supported by the shaft support holes 22b and 24b.

  FIGS. 5A-1 and 5A-2 are a front view and a right side view of the connecting shaft, respectively. As shown in FIGS. 2 and 5A-1 and A-2, the connecting shaft 28 has a flange (head) 28a at a substantially central portion thereof, and large-diameter portions 28bL and 28bR extend on the right and left sides. Is formed into a stepped shape having a small diameter portion 28c.

For example, the bush 30 is wrapped around the right large-diameter portion 28bR, and the large-diameter portion 28bR together with the bush is inserted and fitted into the shaft support hole 22b of the bracket, and the washer is attached to the small-diameter portion 28c extending from the shaft support hole. 32, and the small diameter portion is crimped outside the washer. Instead of caulking the small diameter portion outside the washer 32, the small diameter portion 28c may be welded to the washer outside the washer.
The large-diameter portion 28bL on the left side of the connecting shaft is inserted into and supported by the shaft support hole 24b of the base plate and is integrally welded to the base plate 24.

  While the right end of the connecting shaft 28 is not fixed to the bracket 22, the left end is welded to the base plate 24, and the connecting shaft and the base plate are integrated. According to such a configuration, since the rotation of the connecting shaft 28 with respect to the bracket 22 is ensured by the bush 30 and the washer 32, the base plate 24 is swung relative to the bracket with the connecting shaft as a swing center.

The bush 30 may be omitted and the connecting shaft 28 may be directly supported by the bracket support hole 22b. However, if the bush 30 is interposed around the right-side large-diameter portion 28bR, smooth rotation of the connecting shaft 28 with respect to the bracket 22 can be obtained.
Further, the small diameter portion may be crimped without covering the small diameter portion 28c with the washer 32. However, if the small diameter portion 28c of the connecting shaft is caulked through the washer 32, excessive resistance is prevented from being applied by caulking, and smooth rotation of the connecting shaft relative to the bracket 22 is obtained.

  It is sufficient if the base plate 24 is connected to the bracket 22 so that the connecting shaft 28 is set as the center of swinging, and a configuration opposite to that described above may be employed. That is, the right and left of FIG. 5A-1 are reversed, the right end of the connecting shaft 28 is welded to the bracket 22, the connecting shaft is integrated with the bracket, the washer is put on the left end, and the small diameter portion is crimped. The bracket and the base plate 24 may be connected.

  In the configuration of the embodiment in which the base plate 24 is attached to the recliner 15 provided on the seat back side, the base plate is attached in surface contact with the recliner. Therefore, the connecting shaft 28 is integrated with the bracket 22 and the end of the connecting shaft is caulked on the base plate side. Then, it is difficult to secure a space for storing the crimped portion. On the other hand, if the connecting shaft 28 and the base plate 24 are integrated and the end of the connecting shaft is crimped on the bracket 22 side, a space for storing the crimped portion can be easily secured.

  The connecting shaft 28 is disposed on the rear side with the reclining shaft 16 as a boundary, whereas the shock absorbing plate 26 is disposed between the bracket 22 and the base plate 24 on the front side, that is, on the free end side. For mounting the shock absorbing plate 26, for example, a mounting pin 34 with a flange (head) 34a is used.

  5 (B-1) and 5 (B-2) show a front view and a left side view of the mounting pin, respectively, and the mounting pin has a flange (head) 34a, a large diameter portion 34b, and a small diameter portion 34c as shown in the figure. The attachment pin 34 is inserted into the arc hole, and then inserted into the insertion hole of the shock absorbing plate corresponding to the arc hole, the insertion hole of the base plate or the bracket, and attached by caulking the extending small diameter portion.

  That is, as shown in FIG. 2, the mounting pin 34L is inserted from the base plate 24 side through the arc hole 24c into the shock absorbing plate insertion hole 26c and the bracket insertion hole 22c, and the extending small diameter portion 34c is the bracket 22. Squeezed outside. Further, the mounting pin 34R is inserted from the bracket 22 side through the arc hole 22d through the shock absorbing plate insertion hole 26d and the base plate insertion hole 24d, and the extending small diameter portion 34c is crimped outside the base plate 24.

The mounting pins 34 (34L, 34R) can move in directions close to each other, and the outer end sides of the arc holes 24c, 22d, that is, the mounting pins 34L are the upper ends of the arc holes 24c of the base plate (FIG. 3B). -1), and the mounting pin 34R is inserted into the lower end of the bracket arc hole 22d (the lower end in FIG. 3A-1) and is initially placed.
In such a configuration, one end on the mounting pin 34L side of the shock absorbing plate 26 is fixedly connected to the bracket 22 and the other end on the mounting pin 34R side is fixedly connected to the base plate 24, respectively. Since the base plate and the bracket having the arc holes 24c and 22d through which the mounting pins are inserted are free by the length of the arc hole, the shock absorbing plate is connected to the rear side so as to be swingable. The bracket and the base plate are installed between the front side (free end side) so that they can be bent in the compression direction. The holding strength of the position (angle) of the base plate relative to the bracket is the rigidity of this shock absorbing plate. Will depend on.

  That is, in such a configuration, for example, when an excessive load is applied to the base plate 24 in a direction in which the mounting pins 34 (34L, 34R) approach, and the load exceeds the rigidity of the shock absorbing plate 26, the shock absorbing plate The base plate is swung with respect to the bracket 22 with the connecting shaft 28 as a fulcrum while being bent.

  The impact absorbing device 20 is incorporated into the seat 10 by, for example, fixing the base plate 24 to the outer surface of the recliner 15 and bolting the bracket 22 to the seat cushion frame using the two bolt holes 22e of the bracket.

FIGS. 6A and 6B are front views of the shock absorbing device at the time of normal collision and rear collision, respectively. When the vehicle on which the seat 10 is mounted is traveling normally, the mounting pins 34L and 34R are attached to the arc hole 22c under the holding force resulting from the rigidity of the shock absorbing plate 26, as shown in FIG. , 24c stays in their initial position in contact with the ends on the opposite sides.
Further, since the base plate 24 is fixedly held with respect to the bracket 22 under the rigidity of the shock absorbing plate 26, the base plate is integrated with the bracket in a normal time when the shock absorbing plate is not bent and deformed. By functioning as a seat cushion side member, the tilt of the seat back due to the operation of the recliner 15 can be secured.

When a collision such as a rear collision occurs, an impact force F (see FIG. 1) acts on the seat back 14 from the upper body of the seated person and is transmitted to the base plate 24 via the recliner 15. When the impact force F exceeds the rigidity of the shock absorbing plate 26, the shock absorbing plate starts bending deformation starting from the weakened strength portion, so that the mounting pins 34 (34L, 34R) are inserted into the arc holes 24c, 22d. Move toward each other in the approach direction.
Therefore, the impact force F applied to the seat back 14 at the time of the rear impact is such that the base plate 24 is tilted backward with respect to the bracket 22 with respect to the bracket 22 as shown by an arrow X in FIG. Swing in the same direction, that is, in the clockwise direction in the figure (the backward tilt direction of the seat back).

A base plate 24 is connected to the bracket 22 so as to be relatively swingable by a connecting shaft 28, and is inserted through insertion holes 26c, 26d of the shock absorbing plate 26, and mounting pins 34 (34L, 34R) extending between the base plate and the bracket. One end is inserted into arc holes (long holes) 22d and 24c centering on shaft support holes 22b and 24b through which the connecting shaft 28 is inserted.
Therefore, when the base plate 22 swings in the backward tilt direction of the seat back around the connecting shaft 28, the mounting pins 34L and 34R that are in contact with the mutually separated ends of the arc holes 22d and 24c correspond to the corresponding arc holes 22d and 24c. The bending moment M acts around the mounting pin by moving along the circular arc hole until it is pressed by the adjacent ends.
The clearance between the reclining shaft 16 and the loose insertion hole 22a of the bracket is such that the mounting pins 34L and 34R are swung (swaying) until the corresponding arc holes 22d and 24c are pressed against the mutually adjacent ends. The moving angle θ) is set to an allowable size.

  Since the notched portion 26-1 ′ is provided in the center of the shock absorbing plate 26 and the weakened strength portion 26-1 that easily bends and deforms under a bending moment is formed, the mounting pins 34L and 34R are connected to the circular hole 22d. , 24c, the shock absorbing plate 26 is bent and deformed so as to be folded at the weakened portion by the bending moment. And since the seat back 14 is forcibly tilted backward with the connecting shaft 28 as a fulcrum when the impact absorbing plate 26 is bent and deformed at the weakened strength portion 26-1, the impact energy acting on the seat back at the time of a rear impact. The shock applied to the head and neck of the seated person is reduced and the seated person is protected from the impact at the time of the rear impact.

The deformation of the shock absorbing plate 26 at the weakened strength portion 26-1 is not a deformation in which the deformation resistance sharply decreases like a buckling deformation, but a bending deformation in which the deformation is gently deformed. Can be absorbed.
Since the impact energy at the time of rear impact is absorbed only by the impact absorbing plate 26 interposed between the bracket 22 and the base plate 24, the configuration is simplified and the impact absorbing device 20 can be reduced in weight and size. Further, since the impact energy is absorbed only by the impact absorbing plate 26, the energy absorption characteristics can be freely controlled.
Further, the amount of backward tilting of the seat back with the connecting shaft 28 as a fulcrum is limited as the range of movement of the mounting pins 34L, 34R with respect to the circular arc holes 22d, 24c. Tilt can be reliably prevented.

  The connecting shaft 28 that connects the bracket 22 and the base plate 24 serves as a swing center of the base plate relative to the bracket. When an impact due to a rear impact occurs, the base plate swings differently from the reclining shaft 16 that is the swing center of the seat back 14. It is swung relative to the bracket around the center of movement. Since the connecting shaft 28 is disposed on the rear side with the reclining shaft 16 as a boundary, and the shock absorbing plate 28 is disposed on the front side with the reclining shaft as a boundary, the strength weakened portion 26-of the shock absorbing plate 26- 1 can be set at a position sufficiently away from the center of swinging of the seat back (connection shaft 28) when an impact occurs. In other words, the swinging of the base plate 24 accompanied by the bending deformation of the shock absorbing plate 26 and the backward tilt of the seat back accompanying the occurrence of the impact can be ensured without enlarging the bracket 22 and the base plate 24. Therefore, the impact absorbing device 20 can be reduced in weight and size.

Since the weakly fragile portion 26-1 that is easily bent and deformed is formed by a notch 26-1 ′, and the notch is easily processed by pressing or the like, the weakly fragile portion can be easily formed.
In the embodiment, the notch 26-1 ′ forming the strength weakened portion 26-1 is substantially V-shaped. However, if the strength weakened portion 26-1 that is easily bent and deformed is obtained, the notch The shape is not limited to a substantially V shape. For example, it may be substantially U-shaped, and as shown in FIGS. 4 (B-1) and 4 (B-2), a circular notch 26-1 ′ may be provided at a position shifted from the line 27 connecting the insertion holes 26c and 26d. You may form and provide the weak weak part 26-1.

  The connecting shaft 28 for swingably connecting the base plate 24 to the bracket 22 and the mounting pins 34 for mounting the shock absorbing plate 26 between the bracket and the free ends of the base plate are examples, and are not limited thereto. For example, the shock absorbing plate 26 may be mounted between the bracket 22 and the base plate 24 using bolts and nuts as mounting pins.

  4 (C-1) and 4 (C-2) are a front view and a right side view of a shock absorbing plate according to a modification. This modified example is different from the above-described shock absorbing plate in that it has an extended portion at one end thereof through a weakened strength portion that easily breaks, and other configurations are common. ing. The description of common configurations will be omitted, and different configurations will be described in detail below.

  As shown in FIGS. 4 (C-1) and (C-2), in the shock absorbing plate 126 according to the modification, for example, a side substantially orthogonal to the longitudinal direction of the rectangular shock absorbing plate from one end to the side. On the other hand, the extension part 126a extends through the strength weakened part 126-1. The strength weakened portion 26-1 at the center of the shock absorbing plate is a weakened portion that is easily bent and deformed, whereas the strength weakened portion 126-1 provided between one end of the shock absorbing plate and the extending portion 126a. Is considered to be a fragile part that is easily broken. For example, a notch 126-1 ′ is formed to provide a narrow portion, and a substantially V-shaped groove 126-1 ′ is formed on the surface of the shock absorbing plate at the narrow portion to form a narrow and thin wall. A weakened portion 126-1 is obtained by providing a portion (constriction). For example, the notches 126-1 'and the grooves 126-1 are formed by press work in the same manner as the notches 26-1' of the shock absorbing plate 26.

  Except for the point that the extension 126a of the shock absorbing plate is fixed to the bracket 22 by welding or the like adjacent to the circular arc hole 22d through which the mounting pin 34R is inserted, the shock absorbing plate 126 and the shock absorbing plate 26 described above are used. Similarly, that is, it is arranged and stored between the bracket and the base plate 24 by the mounting pins 34 (34L, 34R).

When the impact force F acts on the seat back 14 due to the rear impact, the base plate 24 is relative to the connection shaft 28 in the clockwise direction (the backward tilt direction of the seat back) as shown by an arrow X in FIG. Try to rock.
In the impact absorbing plate 26 having no extending portion, when the impact force F caused by the rear impact acts on the seat back and the base plate 24 tries to swing in the backward tilting direction of the seat back, the mounting pins 34L and 34R are arc holes. Immediately moving along 22d and 24c, the weakened strength portion 26-1 is deformed by the bending moment M around the mounting pin. That is, the shock absorbing plate 26 is immediately deformed.

On the other hand, in the shock absorbing plate 126 with an extending portion, the extending portion 126a provided at one end thereof is welded to the bracket 22, so that the swing of the base plate 24 is temporarily restricted. That is, the deformation of the shock absorbing plate 126 is prevented until the extending portion 126a is broken and the swing of the base plate 24 becomes free.
Needless to say, the deformation of the shock absorbing plate 126 after the extending portion 126a is broken and the swing of the base plate 24 becomes free is the same as the deformation of the shock absorbing plate 26 without the extending portion.

  8A, 8B, and 8C are schematic views schematically showing the relationship between the pressing force (impact load) acting on the shock absorbing plate and deformation, and FIG. (B) shows an impact absorbing plate without an extending portion, and (C) shows a case where an impact load is received by an impact absorbing plate with an extending portion.

When the load (impact load) F is received only by the extension 126a fixed to the bracket, the impact is proportional to the load up to the load F1 and the displacement S1 at which the strength weakened portion 126-1 of the narrow thin portion is broken. The absorption plate is deformed (elastically deformed) (see FIG. 8A).
In addition, in the shock absorbing plate 26 (see FIG. 4A-1) that does not have an extended portion, the strength weakened portion 26-1 is bent and deformed, and the deformation is elastically deformed to the load F21 (displacement S21). Then, the plastic deformation is relatively large up to the load F22, and the displacement F23 is obtained by the load F23 (see FIG. 8B).

  In the shock absorbing plate 126 with the extending portion (see FIG. 4C-1), it is considered that the deformation shown in FIGS. That is, the bending deformation of the strength fragile portion 26-1 is suppressed until the strength fragile portion 126-1 is broken, and the bending deformation of the strength fragile portion 26-1 occurs after the strength fragile portion 126-1 is broken. As shown in FIG. 8C, the elastic deformation is performed up to the load (F1 + F2), and then the load is reduced to F23 until the displacement S23.

  According to such a two-stage deformation due to the breakage of the weakened strength portion 126-1 and the bending deformation of the weakened strength portion 26-1, the shock absorbing plate 126 with the extension portion is considered. Then, the displacement at the load F22 becomes S3 which is much smaller than the displacement S22 of the load F22 at the impact absorbing plate 26 without the extension, and if this load F22 is considered as the predetermined load, the displacement at the predetermined load can be greatly reduced.

  As described above, in the shock absorbing plate 126, since the elastic deformation of the strength weakened portion 26-1 in the middle portion of the shock absorbing plate is suppressed until the strength weakened portion 126-1 at the end is broken, it can be appropriately controlled. The impact absorbing plate 126 can absorb impact energy at the time of collision more reliably. Further, since the displacement of the shock absorbing plate 126 under a predetermined load is reduced and the forced back tilt angle of the seat back is reduced, the impact applied to the head and neck of the seated person is further reduced, and the impact at the time of the rear impact The seated person is protected more reliably.

  As described above, according to the present invention, the weakened strength portion of the impact absorbing plate is bent and deformed to absorb the impact energy due to the rear impact, and the impact energy at the time of the impact can be absorbed reliably, and the head of the seated person can be absorbed. The impact applied to the head and neck can be reduced and the seated person can be protected from the impact at the time of collision.

  The above-described embodiments are for explaining the present invention, and are not intended to limit the present invention. All modifications, alterations, etc. within the technical scope of the present invention are included in the present invention. Needless to say.

For example, the configuration in which the bracket is fixed to the seat cushion frame and the base plate is fixed to the seat back frame is exemplified. However, it is sufficient if the base plate can swing relative to the bracket. The base plate may be secured to the seat back frame and the seat cushion frame, respectively.
In addition, the configuration in which the connecting shaft is disposed on the rear side of the reclining shaft and the shock absorbing plate is disposed on the front side of the boundary is exemplified. However, the shock absorbing plate can receive the load from the seat back. If necessary, the connecting shaft may be disposed on the front side with the reclining shaft as a boundary, and the impact absorbing plate may be disposed on the rear side with respect to the reclining shaft.

  Moreover, although the collision from the rear (rear collision; rear collision) is illustrated as the collision of the vehicle, the shock absorbing device functions effectively also for the rebound load at the time of the forward collision (front collision; front collision).

Although the present invention is suitable for front seats such as driver seats and assistant seats, it can also be applied to vehicle seats such as second seats and third seats.
Furthermore, it is usually applied to automobile seats, but it can be applied to a wide range of seats for vehicles other than automobiles, such as trains, airplanes, etc., where rear-end collisions and front-end collisions (including “quick braking”) are expected The present invention can also be applied.

10 Vehicle Seat 12 Seat Cushion 14 Seat Back 15 Recliner (Recliner Unit)
16 Reclining shaft 20 Shock absorber 22 Bracket 22b Shaft support hole 22c Insertion hole 22d Arc hole (long hole)
24 base plate 24b shaft support hole 24c arc hole (long hole)
24d Insertion hole 26, 126 Shock absorbing plate 26-1, 126-1 Strength weakened part 26-1 ', 126-1' Notch 26a, 26b Insertion hole 126a Extension part 28 Connection shaft 34 (34L, 34R) Mounting pin

Claims (5)

A bracket fixed to one of the seat back frame and seat cushion frame, a base plate fixed to the other, and a weakened portion that easily bends and deforms under a bending moment, and is attached between the bracket and the base plate. With a shock absorbing plate attached with a pin,
The base plate is mounted so as to be able to swing relative to the bracket at one of the front and rear positions with respect to the swing center different from the swing center of the seat back.
Arc holes are formed in the bracket and base plate at the position of the other free end on the front and rear sides with the seatback swing center as a boundary, and corresponding insertion holes are formed in the base plate and bracket, respectively.
An insertion hole is formed at the end of the shock absorbing plate, and the mounting pin is inserted into the bracket, the arc hole of the base plate, and the insertion hole through the insertion hole at the end, and the shock absorbing plate is interposed between the bracket and the base plate. Let
When the impact force due to a collision is applied to the seat back and the impact force exceeds the rigidity of the impact absorbing plate, the impact absorbing plate is bent and deformed due to the movement of the mounting pin in the arc hole. A shock absorbing device for a vehicle shock absorbing sheet that can be moved relatively to absorb a shock. The shock-absorbing plate has an extended portion at one end extending laterally through a weakened weak portion that easily breaks, and the extended portion is fixed to either the bracket or the base plate at a position adjacent to the arc hole. The shock absorbing device for a vehicle shock absorbing sheet according to claim 1. The impact absorbing device for a vehicle impact absorbing sheet according to claim 1 or 2, wherein a notch is provided in an intermediate portion of the impact absorbing plate to form a weakened strength portion of the intermediate portion. The bracket is fixed to the seat cushion frame, the base plate is fixed to the seat back frame, and the base plate is swingably connected to the bracket by a connection shaft that is supported by the bracket and the shaft support hole of the base plate. 4. The shock absorbing device for a vehicle shock absorbing sheet according to claim 1, wherein the shock absorbing sheet is supported by a shaft supporting hole of a bracket via a bush. The shock absorbing device for a vehicle shock absorbing sheet according to claim 4, wherein one end of the connecting shaft is welded to the base plate, and the other end is crimped by a washer placed on the connecting shaft.

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