JP2009184588A - Rear-end collision impact absorption unit and vehicular seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rear-end collision impact absorption unit capable of stabilizing a rear-end collision impact energy absorption performance as compared with a conventional unit, and also to provide a vehicular seat. <P>SOLUTION: The rear-end collision impact absorption unit 5 includes a plate 20 in a seat cushion side and a plate 30 in a seat back side connected each other so as to relatively rotate at rear-end collision. An impact load absorbing member 50 having a curved part is mounted to the plate 20 in the seat cushion side with a bolt 55. The plate 30 in the seat back side includes a deforming action part 43 engageable with the curved part of the impact load absorbing member 50. With relative rotation of both of the plates 20, 30 at the rear-end collision, the curved part of the impact load absorbing member 50 undergoes bending deformation changing its curved shape by the deforming action part 43. The impact at the rear-end collision is absorbed owing to the bending deformation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rear impact impact absorbing unit used together with a reclining device for adjusting the inclination angle of a seat back in a vehicle seat having a seat cushion and a seat back, and a vehicle seat using the unit.

  A vehicle seat generally includes a seat cushion as a seat, a seat back as a back, and a reclining device. The inclination angle of the seat back with respect to the seat cushion is adjusted by the reclining device, and a comfortable sitting state for the seated person is provided.

  By the way, when a vehicle rear-end collision occurs, the seated person receives a rear impact that is strongly pressed against the seat back of the vehicle seat. In order to reduce the influence of the rear impact on the human body as much as possible, a rear impact impact absorbing technique has been proposed in which the rearward impact of the seat back is gradually changed while absorbing the rear impact. Patent Document 1 discloses a vehicle impact absorbing sheet that is an example of such a rear impact impact absorbing technique. FIG. 16 (a) shows the vehicle impact absorbing sheet disclosed in Patent Document 1, and FIG. 16 (b) is a detailed view of the main part of FIG. 16 (a).

  As shown in FIGS. 16A and 16B, the vehicle impact absorbing sheet 70 includes a seat cushion 11, a seat back 12 that can tilt with respect to the seat cushion 11, and a seat back and forth above the seat back 12. And a headrest 14 that can be installed.

  A back base end frame 72 is rotatably installed at an end of the seat frame 77 that is a skeleton of the seat cushion 11. The seat base frame 77 and the back frame 71 that is the skeleton of the seat back 12 are connected by the back base end frame 72, and the seat back 12 can tilt with respect to the seat cushion 11.

  The vehicle impact absorbing sheet 70 of Patent Document 1 is characterized in that a portion where the back frame 71 is fixedly connected to the back base end frame 72 is an impact absorbing portion 75. That is, the shock absorbing portion 75 includes a fuse mechanism 75a, a rebound suppressing element 75b, and a fulcrum portion 75c formed by fastening both of them with bolt / nut means at the overlapping portion of the back base end frame 72 and the back frame 71. . The fuse mechanism 75a, the rebound suppressing element 75b, and the fulcrum portion 75c are arranged side by side from the front side (the seat cushion 11 side) to the rear side (the seat back 12 side) of the seat 70.

  The fuse mechanism 75 a includes a fuse bolt 71 a that is inserted through a fixing hole provided in the back frame 71 without play and a long hole-like fuse hole 72 a provided in the back base end frame 72. The elongated hole-shaped fuse hole 72a has an insertion hole through which the fuse bolt 71a is inserted without play in a normal state (the state where there is no rear impact), and is continuous with this and once becomes a diameter smaller than the insertion hole, and gradually enters the insertion hole. And a taper-shaped shock absorbing groove that is expanded to have a diameter of.

  The rebound suppressing element 75b includes a rebound suppressing bolt 71b having a small-diameter tip side inserted without play by a fixing hole provided on the back frame 71 side, and a large-diameter portion below the neck, and a long-hole-shaped rebound suppressing hole. 72b. The long hole-shaped rebound suppression hole 72b is provided continuously with an insertion hole for allowing the small-diameter tip side of the rebound suppression bolt 71b to be inserted without play in a normal state (a state where there is no rear impact), and a rear impact. It has a large-diameter hole that allows the rebound suppression bolt 71b to be inserted through the lower-diameter neck lower side without play during shock absorption.

  The fulcrum portion 75c includes a fulcrum bolt 71c that is inserted through the fixing hole provided in the back frame 71 without play, and a fulcrum hole 72c that is provided at the back base frame 72 and allows the fulcrum bolt 71c to be always inserted without play. Yes.

  When receiving a rear impact impact (indicated by a white arrow in FIG. 16A), the back frame 71 tends to tilt backward with respect to the back base end frame 72. At that time, in the shock absorbing portion 75, the fuse mechanism 75a and the rebound suppressing element 75b around the fulcrum portion 75c allow the back frame 71 to tilt backward within the range of the respective long holes, and during the subsequent tilting. Absorbs rear impact energy.

  That is, while the fuse bolt 71a expands and deforms the fuse hole 72a, the fuse mechanism 75a absorbs the rear impact energy by moving in the large diameter direction within the fuse hole 72a. On the other hand, when the back frame 71 tilts to the maximum extent, the lower diameter neck of the rebound suppression bolt 71b fits into the large diameter hole of the rebound suppression hole 72b, so that the rebound suppression element 75b has the back frame 71 rebounded. To suppress and absorb this rebound energy.

As described above, according to the vehicle impact absorbing sheet 70 of Patent Document 1, the rebound suppressing element surely suppresses the rebound movement of the upper body of the seated person (see the paragraph 0060 of the same document), and the fuse mechanism. The impact energy at the time of rear impact is reliably absorbed (see paragraph 0062 of the same document).
Japanese Patent Laid-Open No. 10-309968 (see FIG. 1)

  However, the fuse mechanism 75a of Patent Document 1 absorbs the rear impact energy by expanding and deforming the fuse hole 72a. For this reason, unless the precision of the width | variety of the fuse hole 72a or the processing precision of the inner edge of the fuse hole 72a is high, there existed a fault that the absorption performance of a rear impact energy was not stabilized. Further, in the vehicle impact absorbing sheet 70 of Patent Document 1, the impact absorbing portion 75 is integrated with the seat back frame (the back frame 71 and the back base end frame 72). For this reason, in order to repair and regenerate the vehicle seat after the rear-end collision, it is necessary to replace the entire back base end frame 72 with a new one, and much time and cost are required for repair and regeneration of the vehicle seat. did.

  In addition, as a rear impact impact absorption technology other than the technology of Patent Document 1, for example, there is a technology of absorbing impact energy by shearing a part of a metal member at the time of rear impact. However, the rear impact impact absorption technology based on the shearing of metal members has the disadvantage that the rear impact impact energy absorption performance is not stable, and it is based on such technology to design a vehicle seat with stable impact absorption performance. Is generally considered difficult.

  An object of the present invention is to provide a rear impact impact absorbing unit and a vehicle seat that can stabilize the rear impact impact energy absorption performance more than ever. A further object of the present invention is to provide a rear impact shock absorbing unit and a vehicle seat that are easy to repair and regenerate after a rear-end collision.

  The invention according to claim 1 is a rear impact shock absorbing unit that is used in combination with a reclining device that adjusts an inclination angle of the seat back in a vehicle seat having a seat cushion and a seat back, the seat cushion with respect to a seat frame of the seat cushion. A seat cushion side plate formed to be directly or indirectly connectable, and a seat back side plate formed to be directly or indirectly connectable to the back frame of the seat back, the seat cushion side The plate and the seat back side plate are connected so as to be relatively rotatable at the time of a rear collision, and one of the seat cushion side plate and the seat back side plate is connected to a relative rotation center of the both plates. At a distant position, an impact load absorbing member having a curved portion is provided. The other of the seat cushion side plate and the seat back side plate is provided with a deformation acting portion that can be engaged with the curved portion of the impact load absorbing member, and the seat cushion side plate at the time of a rear collision In response to the relative rotation between the seat back side plate and the seat back side plate, the deformation acting portion absorbs the impact at the time of rear impact by the bending portion of the impact load absorbing member undergoing bending deformation that changes its curved shape. This is a rear impact shock absorbing unit.

  According to a second aspect of the present invention, in the rear impact shock absorbing unit according to the first aspect, the shock load absorbing member provided on the one plate has the curved portion curved in a meandering shape or a substantially S shape. The curved portion of the impact load absorbing member is formed such that its hardness or tensile strength is lower than the hardness or tensile strength of the deformation acting portion provided on the other plate. And

  According to a third aspect of the present invention, in the rear impact impact absorbing unit according to the first or second aspect, the impact load absorbing member has a mounting portion at a proximal end of the curved portion, and is fixed to the mounting portion. A mounting hole into which a tool can be inserted is formed, and the impact load absorbing member is detachably attached to the one plate by the fixing tool inserted into the mounting hole.

  According to a fourth aspect of the present invention, in the rear impact impact absorbing unit according to the third aspect, the other plate provided with the deforming action portion is located at a position away from the relative rotation center of the two plates. An accommodation hole for accommodating the impact load absorbing member provided in one plate is provided, and the accommodation hole accommodates the mounting portion of the impact load absorbing member and the relative rotation of the two plates. Occasionally, a long hole formed in a substantially arc shape so as to allow circumferential movement of the mounting portion, and one end of the long hole portion, meandering to accommodate the curved portion of the impact load absorbing member, or A curved groove part formed in a substantially S shape, and the deformation acting part is provided along a circumferential direction of the accommodation hole in the vicinity of a boundary position between the elongated hole part and the curved groove part of the accommodation hole. One of the two opposite edges Is provided so as to protrude in the radial direction toward the other side, and on the other side of the two opposing edges along the circumferential direction of the accommodation hole, the deformation acting portion and Opposing substantially arcuate guide sides are formed, and the guide sides guide bending deformation of the curved portion of the impact load absorbing member by the deformation acting portion at the time of rear collision.

  According to a fifth aspect of the present invention, in the rear impact impact absorbing unit according to any one of the first to fourth aspects, the seat cushion side plate and the seat back side plate are both concentric and disk-shaped plates. The rear impact shock absorbing unit is further provided with a cover material that covers the outer peripheral portions of the two disk-shaped plates that are overlapped with each other, and the two disk-shaped plates are relatively rotated by the cover material. It is characterized by being integrated in a movable state.

  The invention according to claim 6 is a seat cushion having a seat frame, a seat back having a back frame, a reclining device for adjusting an inclination angle of the seat back, and a rear impact according to any one of claims 1 to 5. A vehicle seat including an absorption unit.

[Additional remarks] Additional or more preferable constituent elements in the present invention are listed below.
I. The seat cushion side plate and the seat back side plate are connected so as to be rotatable relative to each other at the time of rear collision and to be integrally rotatable at the time of non-rear collision (normal time other than the time of rear collision).

  According to the rear impact impact absorbing unit of claim 1, one of the deformation acting portions provided on the other plate causes the one of the deformation action portions provided on the other plate along with the relative rotation between the seat cushion side plate and the seat back side plate at the time of rear impact. The curved portion of the impact load absorbing member provided on the plate is subjected to bending deformation that changes its curved shape, and as a result, the impact at the time of rear impact is absorbed. This shock absorption is based on the bending portion of the impact load absorbing member being bent and deformed from its initial curved shape to another curved shape. Energy absorption based on bending deformation is stable and stable in energy absorption performance compared to energy absorption based on deformation of a large-diameter fuse hole or shearing of a metal member. Therefore, according to the present invention, the absorption performance of the rear impact energy can be dramatically stabilized as compared with the prior art.

  According to the rear impact impact absorbing unit of claim 2, the impact load absorbing member has a curved portion curved in a meandering or substantially S shape, and the hardness or tensile strength of the curved portion is that of the deformation acting portion. It is lower than hardness or tensile strength. Such an impact load absorbing member can be easily mass-produced so as to keep the initial curved shape constant with high accuracy, which greatly contributes to stabilizing the rear impact energy absorption performance. To do.

  According to the rear impact impact absorbing unit of the third aspect, the impact load absorbing member is detachably attached to the one plate by the fixture inserted into the mounting hole of the mounting portion. That is, the impact load absorbing member can be easily attached to and detached from one plate in accordance with the attachment and detachment of the fixture. Further, in the rear impact impact absorbing unit of the present invention, since only the impact load absorbing member is basically deformed by the impact at the time of the rear impact, the impact load absorbing member which is no longer used due to deformation. If only the unit is replaced, the repair and regeneration of the unit is completed immediately. Therefore, according to the present invention, repair and regeneration after a rear-end collision can be performed more easily and easily than before.

  According to the rear impact impact absorbing unit of claim 4, the impact load absorbing member is accommodated in the accommodation hole having the elongated hole portion and the curved groove portion, and the deformation acting portion is provided on one edge along the circumferential direction of the accommodation hole. Is formed on the other edge along the circumferential direction of the receiving hole, and a substantially arcuate guide side facing the deformation acting portion is formed. When a relative rotation occurs between the seat cushion side plate and the seat back side plate at the time of rear-end collision, the deformation action portion and the substantially arc-shaped guide side cooperate to bend with respect to the curved portion of the impact load absorbing member. Add deformation. At that time, the substantially arcuate guide side disposed opposite to the deforming action portion gradually deforms the curved portion of the impact load absorbing member from the initial curved shape (for example, the meandering shape or the substantially S shape) to the substantially arc shape. Induce. Due to the guide side deformation inducing action, the deformation of the curved portion of the impact load absorbing member becomes unambiguous and more stable, so that the rear impact energy absorption performance is further stabilized.

  According to the rear impact impact absorbing unit of claim 5, the seat cushion side plate and the seat back side plate are both configured as concentric and concentric disk-shaped plates, and both the disk-shaped plates have their outer peripheral portions arranged at the outer periphery. It is integrated (unitized) by a cover material that covers it. Therefore, the rear impact impact absorbing unit of the present invention can be retrofitted with respect to an existing vehicle seat reclining device, and is excellent in versatility and convenience as a unit component.

  Since the vehicle seat of the sixth aspect includes the rear impact shock absorbing unit according to the present invention, the effect of the rear impact impact absorbing unit according to the present invention can be the effect of the vehicle seat.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1A and 1B, the vehicle seat 10 of the present embodiment includes a seat cushion 11 that receives a seated portion of the seated person and a seat back 12 that receives the back portion of the seated person. . The seat cushion 11 includes a seat frame 7 serving as a skeleton thereof, and the seat back 12 includes a back frame 8 serving as a skeleton thereof. The seat and back frames 7 and 8 are connected via a reclining device 6 disposed at an end of the seat frame 7. The seat back 12 can tilt with respect to the seat cushion 11 in accordance with the operation of the reclining device 6.

  1 is fixed to the reclining device 6 and includes a serration portion 13a at the tip. Through the serration portion 13a, the rotation shaft 13 shown in FIG. 1 and the rotation shaft (not shown) of the reclining device 6 used between the other seat portion of the vehicle seat 10 and the back frames 7,8. Are coupled so as to rotate synchronously.

  As shown in FIG. 1B, the rear impact impact absorbing unit 5 is provided on the seat back side of the reclining device 6 (that is, between the reclining device 6 and the back frame 8). Here, the plurality of protrusions 6 a on the seat cushion side of the reclining device 6 are fitted into the plurality of through holes 7 a of the seat frame 7, thereby ensuring torque transmission and coaxiality between the two. Further, the plurality of protrusions 6b (see FIG. 2) on the seat back side of the reclining device 6 are fitted into the plurality of through holes 24 on the reclining device side of the rear impact impact absorbing unit 5, thereby transmitting torque between them. Coaxiality is ensured.

  Further, the plurality of projections 36 (see FIG. 2) on the seat back side of the rear impact absorbing unit 5 are fitted into the plurality of through holes 8a of the back frame 8, so that torque transmission and coaxiality between the two are ensured. Has been. In this way, torque transmission and coaxiality regarding tilting between the seat frame 7 and the back frame 8 with the reclining device 6 and the rear impact shock absorbing unit 5 interposed therebetween are ensured.

  When the rear impact absorbing unit 5 is not used, the plurality of projections 6b on the seat back side of the reclining device 6 are fitted into the plurality of through holes 8a on the reclining device 6 side of the back frame 8, so that both Between the transmission of torque and the coaxiality is ensured. Therefore, the rear impact shock absorbing unit 5 can be retrofitted to an existing vehicle seat, except for the problem of the axial distance between the seat frame 7 and the back frame 8.

  Further, the rear impact impact absorbing unit 5 of the present invention is not provided on the seat back side of the reclining device 6 as in the present embodiment, but on the seat cushion side of the reclining device 6 (that is, the reclining device 6 and the seat frame 7). Between the two).

  As described above, the vehicle seat 10 of the present embodiment includes the seat cushion 11 having the seat frame 7, the seat back 12 having the back frame 8, the reclining device 6 that adjusts the inclination angle of the seat back 12, and the rear impact. And an absorption unit 5.

  Next, details of the rear impact shock absorbing unit 5 will be described.

  As shown in FIG. 2 and the like, the rear impact impact absorbing unit 5 of this embodiment includes a seat cushion side plate 20, a seat back side plate 30, three EA plate members 50 as impact load absorbing members, and 3 as a fixture. A bolt 55 and a cover material 57 (see FIG. 10) are provided, and these are integrated to form an independent single unit.

  The seat cushion side plate 20 having a generally disc shape is composed of a circular first plate 21 shown in FIG. 3, an annular second plate 22 shown in FIG. 4, and a short cylindrical sleeve 23 shown in FIG. Has been. The outer shapes of the first and second plates 21 and 22 are the same shape and size, and both the plates 21 and 22 overlap each other to constitute the main body portion of the seat cushion side plate 20. A central hole 21a is formed through the center of the first plate 21, and the diameter of the sleeve 23 substantially corresponds to the inner diameter of the central hole 21a. The sleeve 23 is fixed to the first plate 21 by welding so that the sleeve 23 surrounds the center hole 21a of the first plate.

  As shown in FIGS. 2 and 4, the periphery of the sleeve 23 of the seat cushion side plate 20 (that is, in the first plate 21, an annular region between the outer edge of the center hole 21 a and the inner peripheral edge of the second plate 22). A plurality of through holes 24 (eight in this example) are formed. The first plate 21 and the second plate 22 are respectively formed with three rotation restricting holes 25 and three bolt holes 26 penetratingly formed. In any of the plates 21 and 22, the three rotation restricting holes 25 are arranged at equiangular intervals (ie, 120 ° intervals), and the three bolt holes 26 are arranged at equiangular intervals (ie, 120 ° intervals). . Therefore, when the plates 21 and 22 are overlapped, the rotation limiting hole 25 and the bolt hole 26 of the first plate 21 correspond to the rotation limiting hole 25 and the bolt hole 26 of the second plate 22, respectively.

  In addition, the 1st plate 21 and the 2nd plate 22 are mutually connected by the volt | bolt 55 as a fixing tool used when attaching the EA plate material 50 so that it may mention later.

  As shown in FIG. 2, the seat back side plate 30 has a generally disc shape, and its outer shape is the same shape and size as the outer shape of the seat cushion side plate 20. The seat back side plate 30 is composed of a central support portion (31) occupying the central area of the plate 30 and an annular flat plate-shaped guide plate portion (32) surrounding the central support portion. As can be seen from FIG. 2, the central support portion (31) is formed so as to protrude in the axial direction relative to the guide plate portion (32). A plurality of protrusions 36 (eight in this example) protrude from the end surface of the central support portion (31). These protrusions correspond to the through holes 8a of the back frame 8 respectively.

  The seat back side plate 30 shown in FIG. 2 is shown as a single member in which the central support portion (31) and the guide plate portion (32) are integrally formed from the beginning. The central support member 31 shown in FIG. 6 and the guide plate member 32 shown in FIG. Below, the detail of the said plate 30 is demonstrated about the case where the seat back side plate 30 consists of the center support member 31 and the guide plate member 32. FIG. However, it is added in advance that the following description is also applicable to the case where the seat back side plate 30 is formed of a single member.

  As shown in FIGS. 6A and 6B, the central support member 31 of the seat back side plate 30 is generally disk-shaped, and three protrusions 33 protruding radially outward are formed on the outer periphery thereof. Has been. Each protrusion 33 is formed with a bolt hole 34. These bolt holes 34 are used for mutual fastening between the central support member 31 and the guide plate member 32 using bolts (not shown).

  A central hole 35 is formed through the center of the central support member 31. The center hole 35 has an inner diameter comparable to the outer diameter of the sleeve 23, and the sleeve 23 fixed to the first plate 21 is inserted into the center hole 35 so as to be relatively rotatable. The Further, a plurality of projections 36 (eight in this example) are provided on the end face of the central support member 31 so as to surround the center hole 35.

  As shown in FIGS. 7A and 7B, the guide plate member 32 of the seat back side plate 30 is generally in the shape of an annular flat plate, and a large-diameter circular hole 37 is present at the center thereof. The inner diameter of the circular hole 37 is substantially equal to the diameter of the central support member 31. Further, the guide plate member 32 is provided with three bolt holes 38, three rotation restricting protrusions 39, and three receiving holes 40. The three bolt holes 38 respectively correspond to the three bolt holes 34 in the central support member 31, and are used for mutual fastening between the central support member 31 and the guide plate member 32 using bolts (not shown). Used.

  The three rotation restricting projections 39 are arranged at equiangular intervals (that is, 120 ° intervals) on the guide plate member 32. These rotation restricting protrusions 39 are formed so as to protrude to one surface side of the guide plate member 32 (that is, the surface side facing the seat cushion side plate 20) by punching press processing on the guide plate member 32. Yes. When the rear impact impact absorbing unit 5 is assembled, the three rotation restricting protrusions 39 enter the three rotation restricting holes 25 of the seat cushion side plate 20, respectively. The maximum range of relative rotation between the seat cushion side plate 20 and the seat back side plate 30 is regulated according to the range in which the rotation limiting protrusion 39 can be relatively moved in the circumferential direction within the rotation limiting hole 25. .

  The three receiving holes 40 are arranged at equiangular intervals (ie, 120 ° intervals) in the guide plate member 32 so as to be positioned between two adjacent rotation restricting protrusions 39. Needless to say, these accommodation holes 40 are located away from the relative rotation center C of the plates 20 and 30.

  The accommodation hole 40 is a hole for accommodating the EA plate material 50 as the impact load absorbing member, and has a shape as shown in FIGS. 7 and 8. On the other hand, the EA plate material 50 has a shape as shown in FIG. As shown in FIG. 9, the EA plate material 50 has a mounting portion 51 and a curved portion 52. The attachment portion 51 has a generally circular shape and is located at the proximal end portion of the bending portion 52. The bending portion 52 is curved so that its front view shape is serpentine or substantially S-shaped. An attachment hole 53 into which a bolt 55 as a fixture can be inserted is formed through the attachment portion 51 of the EA plate material.

  On the other hand, as shown in particular in FIG. 8, the accommodation hole 40 has a long hole portion 41 and a curved groove portion 42 continuous with one end of the long hole portion 41. The long hole portion 41 is a part mainly for accommodating the attachment portion 51 of the EA plate material 50, and is a short arc to allow the attachment portion 51 to move in the circumferential direction when the plates 20 and 30 are relatively rotated. It is formed in the shape along. The curved groove portion 42 is a portion for accommodating the curved portion 52 of the EA plate material 50, and is formed in a meandering shape or a substantially S shape so as to substantially match the shape of the curved portion 52 of the EA plate material. .

  Further, the guide plate member 32 is provided with a deformation acting portion 43 in the vicinity of the boundary position between the elongated hole portion 41 and the curved groove portion 42 of the accommodation hole 40. The deformation acting portion 43 protrudes in the radial direction (radial direction) from the inner side 44 to the outer side 45 of the two opposing edges (44, 45) along the circumferential direction of the accommodation hole 40. It is formed in a chevron shape. As will be described later, the deformation action portion 43 is a portion (convex portion) for engaging with the bending portion 52 of the EA plate material and exerting a deformation action on the bending portion 52. Further, the outer side 45 of the accommodation hole 40 functions as a substantially arcuate guide side facing the deformation acting portion 43. In other words, the outer side 45 serving as a guide side guides the bending deformation of the curved portion 52 of the EA plate material by the deformation acting portion 43 in cooperation with the deformation acting portion 43 at the time of rear collision.

  In this embodiment, the guide plate member 32 and the EA plate material 50 are made of the same kind of steel material, but the guide plate member 32 is quenched, whereas the EA plate material 50 is quenched. No curing treatment is performed. As a result of quenching, the hardness and tensile strength of the guide plate member 32 are about 1.5 times to about 2.5 times the hardness and tensile strength of the EA plate material 50. That is, the curved portion 52 of the EA plate material 50 is formed such that its hardness or tensile strength is lower than the hardness or tensile strength of the deformation acting portion 43 of the guide plate member 32.

  In the present embodiment, the bolt hole 38 is provided in the inner region of the deformation acting portion 43, but the arrangement of the bolt hole 38 is not limited to the portion.

  The rear impact impact absorbing unit 5 of this embodiment is assembled as shown in FIG. That is, the seat cushion side plate 20 in which the first and second plates 21 and 22 are overlapped is prepared, and the seat back side plate 30 in which the central support member 31 and the guide plate member 32 are integrated is prepared. Then, the plates 20 and 30 are brought into contact with each other while the sleeve 23 of the seat cushion side plate 20 is inserted into the center hole 35 of the seat back side plate 30. After adjusting the phase of both plates 20 and 30 so that the bolt hole 26 is exposed from the long hole portion 41 of each accommodation hole 40, the EA plate material 50 is fitted to each accommodation hole 40 as shown in FIG. Let Then, the bolts 55 are inserted into the mounting holes 53 of the EA plate members 50, and the shaft ends of the bolts 55 are screwed into the bolt holes 26 of the seat cushion side plate 20.

  As a result, the EA plate material 50 disposed in the accommodation hole 40 is attached to the seat cushion side plate 20 by the bolts 55, and the first and second plates 21 and 22 are fastened together so that both plates 21 and 22 are tightened. Are integrated at the same time. When the assembly is completed, as shown in FIG. 14, the deformation acting portion 43 of the guide plate member 32 is deformed by the bending portion 52 (more specifically, the bending portion 52 of the EA plate material 50 attached to the seat cushion side plate 20). The seat back side plate 30 is relatively rotated with respect to the seat cushion side plate 20 because it engages with a recess portion secured between the front end portion and the mounting portion 51 to regulate the circumferential movement of each other. Does not occur at non-rear collision (normal time other than rear collision).

  Although not shown in FIG. 2, the rear impact impact absorbing unit 5 includes a cover material 57 as shown in FIGS. 10 (a) and 10 (b). The cover member 57 has a generally ring shape so as to cover the outer peripheral portions of the two plates 20 and 30 brought into contact with each other as described above. The cover member 57 has a flange portion 58 that extends inward on one end side in the width direction. As shown in FIG. 10C, after the cover material 57 is attached to the outer peripheral portions of the plates 20 and 30, the second flange portion is bent by bending the other end side (the side without the flange portion 58) of the cover material 57. By creating 59, the two plates 20, 30 are integrated in a state in which they cannot be separated from each other but are relatively rotatable.

  Next, the operation and effect of the rear impact impact absorbing unit 5 of this embodiment will be described.

  At the time of non-rear collision (normal time other than the time of rear collision), each EA plate material 50 is disposed in a standby position as shown in FIGS. 12 and 14 in the corresponding accommodation hole 40. At the time of such non-rear impact, no relative rotation occurs between the seat cushion side plate 20 and the seat back side plate 30 constituting the rear impact impact absorbing unit 5, and the unit 5 is as if the reclining device 6 It behaves as if it is a part. That is, the rear impact shock absorbing unit 5 directly transmits the operation of the reclining device 6 to the back frame 8 as it is. As a result, the seat back 12 is supported at an inclination angle (a support position indicated by a solid line in FIG. 11) determined by the reclining device 6 with respect to the seat cushion 11.

  At the time of a rear impact, a rear impact that tries to tilt the seat back 12 toward the position (the position indicated by the phantom line in FIG. 11) retracted from the original support position (the position indicated by the solid line in FIG. 11) is applied to the entire seat. Join. At that time, in the rear impact shock absorbing unit 5, a force to rotate the seat back side plate 30 relative to the seat cushion side plate 20 connected to the fixed side (that is, in FIG. 11 to FIG. A force is applied to the deformation acting portion 43 of the plate member 32 to rotate clockwise. When the force resulting from the rear impact exceeds a predetermined threshold value, the seat back side plate 30 rotates relative to the seat cushion side plate 20. That is, the deforming action portion 43 of the guide plate member 32 forcibly deforms the bending portion 52 of the EA plate material 50 from the standby state of FIGS. 12 and 14 to the state after the deformation of FIGS. 13 and 15. As a result, the curved portion 52 is extended from the initial meandering shape or substantially S-shape to a substantially arc shape along the outer side 45 of the accommodation hole 40. The extended deformation of the EA plate material bending portion 52 absorbs the energy of the rear impact, and the impact on the occupant seated on the seat is greatly reduced.

  According to the rear impact impact absorbing unit of the present embodiment, the deformation acting portion provided on the seat back side plate 30 with the relative rotation between the seat cushion side plate 20 and the seat back side plate 30 at the time of the rear impact. 43, the curved portion 52 of the EA plate material 50 provided on the seat cushion side plate 20 is subjected to bending deformation that changes its curved shape, and as a result, the impact at the time of rear collision is absorbed. This shock absorption is based on the bending portion 52 of the EA plate material 50 being bent and deformed from its initial curved shape to a curved shape after deformation (see FIG. 15). Energy absorption based on bending deformation is stable and stable in energy absorption performance compared to energy absorption based on large-diameter fuse hole deformation and metal member shearing. Absorption performance can be dramatically stabilized.

  The EA plate material 50 as an impact load absorbing member has a curved portion 52 curved in a meandering or substantially S shape, and the hardness or tensile strength of the curved portion 52 is the hardness or tensile strength of the deformation acting portion 43. Lower than. Such an EA plate material 50 can be easily mass-produced so as to keep its initial curved shape constant with high accuracy, and this greatly helps to stabilize the absorption performance of the rear impact energy.

  The EA plate material 50 as an impact load absorbing member is detachably mounted on the seat cushion side plate 20 by a bolt 55 inserted into the mounting hole 53 of the mounting portion 51. That is, the EA plate material 50 can be easily attached to and detached from the plate 20 in accordance with the attachment and detachment of the bolt 55 as a fixing tool. Further, since only the EA plate material 50 is basically deformed by the impact at the time of rear impact, if only the EA plate material 50 that has been used due to deformation is replaced, the unit 5 can be repaired and regenerated. Completes instantly. Therefore, according to this embodiment, repair and regeneration after a rear-end collision can be performed more easily and easily than in the past.

  In the present embodiment, the EA plate material 50 is accommodated in the accommodation hole 40 having the long hole portion 41 and the curved groove portion 42, and the deformation acting portion 43 is formed to project on the inner side 44 of the accommodation hole 50. A substantially arcuate guide side 45 facing the deformation acting part 43 is formed on the outer side 45. When a relative rotation occurs between the seat cushion side plate 20 and the seat back side plate 30 at the time of a rear collision, the deformation action portion 43 and the substantially arcuate guide side 45 cooperate to curve the EA plate material 50. A bending deformation is imparted to the portion 52. At that time, the substantially arcuate guide side 45 disposed opposite to the deformation acting portion 43 guides the bending portion 52 to gradually deform from the initial curved shape to the substantially arc shape. Due to the deformation inducing action of the guide side 45, the deformation of the curved portion 52 of the EA plate material 50 becomes unambiguous and more stable, so that there is an advantage that the rear impact energy absorption performance is further stabilized. .

  The seat cushion side plate 20 and the seat back side plate 30 are both configured as concentric and disk-shaped plates, and both the plates 20 and 30 are integrated by a cover material 57 covering their outer peripheral portions. . Therefore, the rear impact shock absorbing unit 5 can be retrofitted with respect to the existing reclining device 6 of the vehicle seat 10 and is excellent in versatility and convenience as a unit component.

  [Modification] The present invention is not limited to the above-described embodiment shown in FIGS. For example, in the rear impact impact absorbing unit, a configuration is adopted in which the seat back side plate 30 is provided with the EA plate material 50 as an impact load absorbing member, and the seat cushion side plate 20 is provided with the accommodation hole 40 and the deformation acting portion 43. May be.

Fig.1 (a) is a schematic side view which shows an example of the vehicle seat provided with the rear collision impact absorption unit of this invention, FIG.1 (b) is a disassembled perspective view of the reclining apparatus part of (a). FIG. 2 is a perspective view mainly showing an exploded state of the rear impact shock absorbing unit. FIG. 3: shows the circular 1st plate which comprises a seat cushion side plate, (a) is the front view, (b) is the side view. 4A and 4B show a ring-shaped first plate constituting the seat cushion side plate, FIG. 4A is a front view thereof, and FIG. 4B is a side view thereof. FIG. 5 shows a short cylindrical sleeve constituting the seat cushion side plate, (a) is a front view thereof, and (b) is a side view thereof. 6A and 6B show a central support member constituting the seat back side plate, wherein FIG. 6A is a front view thereof, and FIG. 6B is a side view thereof. FIG. 7 shows a guide plate member constituting the seat back side plate, (a) is a front view thereof, and (b) is a side view thereof. FIG. 8 is an enlarged front view of a part (main part) of the guide plate member. FIG. 9 is a front view of the EA plate material. 10A and 10B show a cover material that covers the outer periphery of the rear impact shock absorbing unit. FIG. 10A is a front view thereof, FIG. 10B is a cross-sectional view taken along line XX, and FIG. The partial expanded sectional view which shows the state. FIG. 11 is a side view of the seat for explaining the operation of the rear impact impact absorbing unit. FIG. 12 is an enlarged view of a rear impact impact absorbing unit before and after the rear impact. FIG. 13 is an enlarged view of the rear impact impact absorbing unit after the rear impact and its surroundings. FIG. 14 is an enlarged view of a main part corresponding to FIG. 8 showing a state before the rear collision. FIG. 15 is an enlarged view of a main part corresponding to FIG. 8, showing a state after the rear impact. FIG. 16A is a schematic side view showing a conventional vehicle impact absorbing sheet, and FIG. 16B is a detailed view of the main part of FIG.

Explanation of symbols

5 ... rear impact shock absorbing unit 6 ... reclining device 7 ... seat cushion seat frame 8 ... seat back back frame 11 ... seat cushion 12 ... seat back 20 ... seat cushion side plate 30 ... seat back side plate 40 ... accommodation hole 41 ... Long hole part 42 ... Curved groove part 43 ... Deformation action part 44 ... Inner side 45 ... Outer side (guide side)
50 ... EA plate material (impact load absorbing member)
51 ... EA plate material mounting portion 52 ... EA plate material curved portion 53 ... mounting hole 55 ... bolt (fixing tool)
57 ... Cover material C ... Center of relative rotation

Claims (6)

A rear impact impact absorbing unit used in combination with a reclining device for adjusting the inclination angle of the seat back in a vehicle seat having a seat cushion and a seat back,
A seat cushion side plate formed so as to be directly or indirectly connectable to the seat frame of the seat cushion;
A seat back side plate formed so as to be directly or indirectly connectable to the back frame of the seat back;
The seat cushion side plate and the seat back side plate are connected so as to be relatively rotatable at the time of a rear collision,
One of the seat cushion side plate and the seat back side plate is provided with an impact load absorbing member having a curved portion at a position away from the relative rotation center of the two plates.
The other of the seat cushion side plate and the seat back side plate is provided with a deformation acting portion that can be engaged with the curved portion of the impact load absorbing member,
As the seat cushion side plate and the seat back side plate are rotated relative to each other at the time of rear collision, the bending portion of the impact load absorbing member undergoes bending deformation that changes its bending shape by the deformation acting portion. The rear impact absorbing unit is characterized by absorbing the impact at the time of rear impact. The impact load absorbing member provided on the one plate has the curved portion curved in a meandering shape or a substantially S shape,
The curved portion of the impact load absorbing member is formed such that its hardness or tensile strength is lower than the hardness or tensile strength of the deformation acting portion provided on the other plate,
The rear impact shock absorbing unit according to claim 1, wherein   The impact load absorbing member has a mounting portion at a base end of the curved portion, and a mounting hole into which a fixing tool can be inserted is formed in the mounting portion, and the fixing inserted into the mounting hole. The rear impact impact absorbing unit according to claim 1 or 2, wherein the impact load absorbing member is detachably attached to the one plate by a tool. The other plate provided with the deformation acting portion has an accommodation hole for accommodating the impact load absorbing member provided on the one plate at a position away from the relative rotation center of the both plates. Provided,
The accommodation hole is
An elongated hole formed in a substantially arc shape to accommodate the mounting portion of the impact load absorbing member and allow circumferential movement of the mounting portion when the two plates are relatively rotated,
And a curved groove formed in a meandering or substantially S shape so as to accommodate the curved portion of the impact load absorbing member while continuing to one end of the elongated hole portion,
In the vicinity of the boundary position between the elongated hole portion and the curved groove portion of the accommodation hole, the deforming action portion is arranged from one side to the other side of two opposing edges along the circumferential direction of the accommodation hole. It is provided to project in the radial direction toward
On the other side of the two opposing edges along the circumferential direction of the accommodation hole, a substantially arcuate guide side that faces the deformation acting portion is formed, and the guide side is Guiding the bending deformation of the curved portion of the impact load absorbing member by the deformation acting portion at the time of rear collision,
The rear impact shock absorbing unit according to claim 3, wherein The seat cushion side plate and the seat back side plate are both configured as concentric and disk-shaped plates,
The rear impact shock absorbing unit further includes a cover material that covers the outer peripheral portions of the two disk-shaped plates that are overlapped with each other, and the two disk-shaped plates can be relatively rotated by the cover material. The rear impact impact absorbing unit according to any one of claims 1 to 4, wherein the rear impact impact absorbing unit is integrated. A seat cushion having a seat frame;
A seat back having a back frame;
A reclining device for adjusting the inclination angle of the seat back;
A vehicle seat comprising the rear impact impact absorbing unit according to any one of claims 1 to 5.

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