JP6611634B2 - Vehicle seat - Google Patents

Description

  The present invention relates to a vehicle seat.

  A seat belt is used as a safety device for protecting an occupant in the event of a vehicle collision, and a force limiter for the seat belt is known as an accessory device for enhancing the occupant protection performance. The force limiter gradually relaxes the shoulder belt that hangs diagonally on the occupant's upper body from the occupant's shoulders to the lower back, reducing the impact on the occupant's upper body restrained by the shoulder belt. It is provided in the retractor which winds up the seat belt.

  Also, a vehicle seat configured to relieve an impact applied to the upper body of an occupant restrained by a shoulder belt by plastic deformation of a frame material of the seat is known (for example, , See Patent Document 1).

  The vehicle seat described in Patent Document 1 is a so-called belt-in seat in which a retractor that winds up a seat belt is incorporated, and a seat back frame is supported by the lower structure and the lower structure so as to be tiltable forward of the seat. The upper end of the shoulder belt is moored to a side frame on one side of the upper structure. A torsion bar is bridged between a side frame on one side of the upper structure on which the shoulder belt is anchored and a side frame on the opposite side of the lower structure. When a tensile load exceeding a predetermined value is applied to the shoulder belt, the upper structure tilts toward the front of the seat with the twisting of the torsion bar, and the impact is alleviated.

Japanese Patent Laid-Open No. 9-24756

  In the force limiter that gradually loosens the shoulder belt, the upper part of the occupant falls toward the front of the seat, and there is a gap between the upper part of the occupant and the seat back, causing the recoil to fall toward the front of the seat. Therefore, there is a possibility that the upper body which is turned back toward the back of the seat is hit against the seat back. Moreover, in the passenger | crew of the back row seat, there existed a possibility that the upper body which fell toward the front of a seat may be hit | damaged to the seat back of a front row seat.

  On the other hand, in the vehicle seat described in Patent Document 1, since the upper structure of the seat back falls down together with the upper body of the occupant toward the front of the seat, there is a gap between the upper body of the occupant and the seat back. Is suppressed, and the contact between the upper body and the seat back when the upper body leans back toward the rear of the seat due to the recoil that falls toward the front of the seat is alleviated. Further, in the case of the occupant of the rear row seat, the upper structure of the seat back of the front row seat collapses toward the front of the seat, so that the space between the upper structure and the upper body and the seat back of the front row seat is increased. Is suppressed.

  However, in the vehicle seat described in Patent Document 1, only one shoulder portion of the left and right shoulder portions of the occupant is supported by the shoulder belt. For this reason, when the upper body of the occupant leans toward one shoulder supported by the shoulder belt in an oblique collision, the intended restraint performance by the shoulder belt can be exhibited, but the other shoulder side In the case of falling and leaning, the restraint performance by the shoulder belt may be reduced.

  In the vehicle seat described in Patent Document 1, the torsion bar is stretched between a side frame on one side of the upper structure that anchors the shoulder belt and a side frame on the opposite side of the lower structure. . For this reason, when the upper body of the occupant leans toward one shoulder supported by the shoulder belt and falls, that is, when the upper body that anchors the shoulder belt leans toward one side frame, the shoulder belt Combined with the intended restraint performance, the torsion rods are expected to twist, and the impact mitigation by the torsion rods can also function effectively. If the body is tilted to the opposite side of the side frame side of the superstructure that anchors the shoulder belt, the torsion of the torsion bar is insufficient due to the reduced restraining performance of the shoulder belt. However, there is a possibility that the relaxation of the impact by the torsion rod is attenuated.

  This invention is made | formed in view of the situation mentioned above, and aims at improving the passenger | crew protection performance of a vehicle seat.

  The vehicle seat according to one aspect of the present invention can tilt the seat cushion, a seat back having a pair of side frames arranged at intervals in the seat width direction, and the pair of side frames in the seat front-rear direction. A pair of connecting portions connected to the frame of the seat cushion, and a seat belt having a pair of shoulder belts that are moored to each of the pair of side frames and support the left and right shoulders of the occupant, Each of the pair of connecting portions includes a deforming member that is plastically deformed when a tensile load exceeding a predetermined value is applied to the shoulder belt moored to the side frame supported by the connecting portion. A force limiter portion that allows the side frame to tilt toward the front of the seat by plastic deformation.

  ADVANTAGE OF THE INVENTION According to this invention, the passenger | crew protection performance of a vehicle seat can be improved.

It is a perspective view of an example of a vehicular seat for explaining an embodiment of the present invention. It is a perspective view of the connection part of the vehicle seat of FIG. It is a disassembled perspective view of the connection part of the vehicle seat of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a perspective view which shows operation | movement of the vehicle seat of FIG. It is a perspective view of the connection part of the modification of the vehicle seat of FIG. It is a perspective view which shows operation | movement of the vehicle seat of FIG. It is a perspective view of the connection part of the other example of the vehicle seat for demonstrating embodiment of this invention. It is a perspective view of the connection part of the vehicle seat of FIG. It is a perspective view of the deformation member of the connection part of the vehicle seat of FIG. It is sectional drawing of the XI-XI line of FIG. It is a perspective view which shows operation | movement of the vehicle seat of FIG. It is a perspective view of the connection part of the other example of the vehicle seat for demonstrating embodiment of this invention. It is a perspective view of the connection part of the vehicle seat of FIG. It is sectional drawing of the connection part of the vehicle seat of FIG. It is a perspective view of other examples of a vehicular seat for explaining an embodiment of the present invention.

  FIG. 1 shows an example of a vehicle seat for explaining an embodiment of the present invention.

  The vehicle seat 101 includes a seat cushion 102 that constitutes a seat surface portion, a seat back 103 that constitutes a backrest portion, and a seat belt 105.

  The seat cushion 102 includes a cushion frame 110 that forms a skeleton of the seat cushion 102. The cushion frame 110 is configured to include a pair of cushion side frames 111 and 112 arranged at intervals in the seat width direction, and a cross frame 113 that connects the pair of cushion side frames 111 and 112 to each other. . The cushion frame 110 is covered by a cushion pad made of a relatively soft resin foam material such as urethane foam, and further covered by a trim cover made of a sheet material such as vinyl chloride.

  The seat back 103 includes a back frame 120 that forms a skeleton of the seat back 103. The back frame 120 includes a pair of back side frames 121 and 122 arranged at intervals in the seat width direction, an upper cross frame 123 that connects the upper ends of the pair of back side frames 121 and 122 to each other, It includes a lower cross frame 124 that connects the lower ends of the side frames 121 and 122 to each other. The back frame 120 is also covered with a cushion pad and a trim cover, similarly to the cushion frame 110 of the seat cushion 102.

  The back side frame 121 is connected to the cushion side frame 111 on the same side as the back side frame 121 via the connecting portion 126. The back side frame 122 is also connected to the cushion side frame 112 on the same side as the back side frame 122 via the connecting portion 127. The connecting portions 126 and 127 are cushioned so that the back side frames 121 and 122 can be tilted in the seat front-rear direction with a rod 129 extending between the connecting portion 126 and the connecting portion 127 extending in the seat width direction as a tilting axis. The side frames 111 and 112 are connected.

  Although illustration is omitted, reclining devices are interposed between the connecting portion 126 and the cushion side frame 111 and between the connecting portion 127 and the cushion side frame 112, respectively. These reclining devices are configured so that the tilt angle of the back side frames 121 and 122 can be adjusted with the rod 129 as the tilt axis.

  When the tilt angle of the backside frames 121 and 122 around the rod 129 is adjusted by the reclining device, the connecting portions 126 and 127 that similarly support the backside frames 121 and 122 around the rod 129 so as to tilt are provided on the backside frame. Rotate around the rod 129 together with 121 and 122. Then, when the reclining device is locked so that the back side frames 121 and 122 are held at the adjusted tilt angle, the connecting portions 126 and 127 are also fixed.

  The seat belt 105 is a so-called four-point seat belt, and a pair of lap belts 105a and 105b that are wound around the waist of an occupant seated on the vehicle seat 101 and a pair of left and right shoulders of the occupant. Shoulder belts 105c and 105d.

  One end of the lap belt 105 a is fixed to the cushion side frame 111. One end of the lap belt 105b is fixed to the cushion side frame 112. The lap belts 105a and 105b are connected by a buckle 107 so as to be separable at a substantially center position in the width direction of the occupant's waist.

  In the seat back 103, retractors 104c and 104d for winding the shoulder belts 105c and 105d, respectively, are incorporated. The retractor 104 c is disposed on the back side frame 121 side and is fixed to the back side frame 121 via a retractor fixing bracket 125. The retractor 104 d is disposed on the back side frame 122 side and is fixed to the back side frame 122 via a retractor fixing bracket 125.

  The retractors 104c and 104d are so-called emergency lock type retractors, and are configured to prevent the shoulder belts 105c and 105d from being fed when a sudden deceleration is applied due to a vehicle collision or the like. The retractors 104c and 104d have a so-called pretensioner function that automatically winds up the shoulder belts 105c and 105d and actively restrains the occupant's upper body to the seat back 103 when sudden deceleration is applied. You may have. However, the retractors 104c and 104d have a so-called force limiter function that gradually pulls out the shoulder belts 105c and 105d to loosen the restraint of the occupant's upper body when an excessive tensile load acts on the shoulder belts 105c and 105d. Not done.

  The shoulder belt 105 c is moored by a shoulder bracket 106 c provided at the upper end of the back side frame 121, pulled out to the front side of the seat back 103, and joined to the lap belt 105 a in the vicinity of the buckle 107. The shoulder belt 105c hangs obliquely on the occupant's upper body from the left shoulder of the occupant to the center of the waist in the width direction, and supports the left side of the occupant's upper body including the left shoulder.

  The shoulder belt 105 d is anchored by a shoulder bracket 106 d provided at the upper end of the back side frame 122, pulled out to the front side of the seat back 103, and joined to the lap belt 105 b in the vicinity of the buckle 107. The shoulder belt 105d hangs diagonally on the occupant's upper body from the shoulder on the right side of the occupant to the center of the waist in the width direction, and supports the right side of the occupant's upper body including the right shoulder.

  The seat belt 105 only needs to have a pair of shoulder belts 105c and 105d that support the left and right shoulders of the occupant. For example, the seat belt 105 further includes a crotch belt that supports the crotch of the occupant. A six-point seat belt may be used.

  2 to 4 show the configuration of the connecting portion 126 that connects the cushion side frame 111 and the back side frame 121.

  The connecting portion 126 includes a force limiter portion 131, and the force limiter portion 131 includes a base bracket 142, a back bracket 143, and a deformation member 144.

  The base bracket 142 is disposed so as to overlap the back side frame 121 side of the rear end portion 111 a of the cushion side frame 111 connected to the back side frame 121. The base bracket 142 is joined to a reclining device 109 interposed between the connecting portion 126 and the cushion side frame 111. When the reclining device 109 is in a locked state, the cushion side frame is interposed via the reclining device 109. 111 is fixed.

  The back bracket 143 is disposed so as to overlap the cushion side frame 111 side of the lower end portion 121 a of the back side frame 121 connected to the cushion side frame 111. The back bracket 143 is joined to the back side frame 121.

  A collar 147 disposed on the outer periphery of the rod 129 is joined to the base bracket 142 coaxially with the rod 129 that is the tilting axis of the back side frame 121, and the back bracket 143 joined to the back side frame 121 slides. The portion 150 is slidably supported by a collar 147 and a washer 148 attached to the collar 147.

  The deformable member 144 is a strip-shaped member made of a plastically deformable metal material, is sandwiched between the base bracket 142 and the back bracket 143, and is disposed so as to extend in the front-rear direction of the seat.

  A through hole through which the engagement pin 145 is inserted is provided in the first end portion 144a on the seat rear side of the deformable member 144, and the first end portion 144a is formed by the engagement pin 145 inserted through the through hole. The base bracket 142 is joined. By fixing the base bracket 142 to the cushion side frame 111 via the reclining device 109 in a locked state, the first end portion 144 a of the deformable member 144 is also fixed to the cushion side frame 111.

  Further, a through hole through which the engagement pin 146 is inserted is provided in the second end portion 144b of the deformation member 144 on the front side of the seat, and the second end portion 144b is an engagement pin inserted through the through hole. 146 is joined to the back bracket 143 and fixed to the back side frame 121 to which the back bracket 143 is joined.

  The base bracket 142 is provided with a long hole 142a extending along the track of the engagement pin 146 when the backside frame 121 is tilted toward the front of the seat, and the long hole 142a has a deformation member 144 formed therein. One end of the engaging pin 146 inserted through the through hole of the second end 144b is accommodated.

  When the occupant leans against the seat back 103, a load that tilts the back side frame 121 toward the rear of the seat is applied to the back side frame 121. This load is borne by the contact between the engagement pin 146 and the end surface of the long hole 142a of the base bracket 142 on the seat rear side, and the tilt of the back side frame 121 toward the seat rear is prevented.

  One end portion of the engagement pin 145 inserted through the through hole of the first end portion 144a of the deformable member 144 is brought into contact with the side surface of the back bracket 143 on the seat rear side, and the back side frame 121 is moved to the rear of the seat. A part of the load to be tilted toward the engagement pin 145 may be borne, and the load applied to the engagement pin 146 may be reduced. Preferably, as shown in FIG. 3, an arcuate recess 143 a that is aligned with the outer peripheral surface of the engagement pin 145 is formed on the side surface portion of the back bracket 143 with which the engagement pin 145 contacts.

  In the event of a vehicle collision or the like, a tensile load is applied to the shoulder belt 105c (see FIG. 1) of the seat belt 105 that restrains the upper body of an occupant who falls to the front of the seat due to inertia to the seat back 103, and the shoulder belt 105c The back side frame 121 provided with the shoulder bracket 106c to be moored is loaded with a load corresponding to a tensile load applied to the shoulder belt 105c and tilting the back side frame 121 toward the front of the seat. . This load is applied to the deformation member 144 in which the first end portion 144 a is fixed to the cushion side frame 111 and the second end portion 144 b is fixed to the back side frame 121.

  When the tensile load applied to the shoulder belt 105c is relatively small and the stress acting on the deformation member 144 is less than the yield stress of the deformation member 144, the load applied to the deformation member 144 is the deformation member. It is borne by the rigidity of 144. Thereby, the tilt of the back side frame 121 toward the front of the seat is prevented.

  On the other hand, when a tensile load exceeding a predetermined value is applied to the shoulder belt 105c and the stress acting on the deformable member 144 exceeds the yield stress of the deformable member 144, as shown in FIG. Plastically stretched in the direction. Then, when the deformable member 144 is extended, the back side frame 121 is allowed to tilt toward the front of the seat, and the back side frame 121 tilts toward the front of the seat together with the upper body of the occupant. At that time, energy is absorbed by plastic deformation of the deformable member 144. Thereby, the impact applied to the upper body of the occupant restrained by the shoulder belt 105c is alleviated.

  As the back side frame 121 tilts toward the front of the seat, the engagement pin 146 moves through the long hole 142a of the base bracket 142 toward the front of the seat and comes into contact with the end surface of the long hole 142a on the front side of the seat. After the engagement pin 146 comes into contact with the end surface of the long hole 142a on the seat front side, the back side frame 121 is prevented from tilting toward the seat front. Thereby, it is avoided that the deformation member 144 extends excessively and breaks, and the certainty of the operation of the force limiter unit 131 can be improved.

  Further, the deformable member 144 is sandwiched between the base bracket 142 and the back bracket 143, and the plastic deformation of the deformable member 144 is defined as the deformation between the base bracket 142 and the back bracket 143. Thereby, the deformable member 144 can be plastically deformed as expected, and the deformable member 144 can absorb energy more reliably.

  The connecting portion 127 that connects the cushion side frame 112 and the back side frame 122 also has a force limiter portion, and the force limiter portion of the connecting portion 127 is configured in the same manner as the force limiter portion 131 of the connecting portion 126.

  In the vehicle seat 101 configured as described above, since the left and right shoulders of the occupant are supported by the pair of shoulder belts 105c and 105d, the upper body of the occupant leans to the left or right side during an oblique collision. Even so, the upper body of the occupant can be sufficiently restrained. A force limiter is provided at both the connecting portion 126 of the backside frame 121 that anchors the shoulder belt 105c and the connecting portion 127 of the backside frame 122 that anchors the shoulder belt 105d. Even if the upper body is tilted to the left or right side, the shoulder belts 105c and 105d can sufficiently restrain the upper body of the occupant as described above, and effectively reduce the impact by the force limiter. Can be made. Thereby, the passenger | crew protection performance of the vehicle seat 101 can be improved.

  FIG. 6 shows a modification of the vehicle seat 101.

  In the vehicle seat 101 described above, the deformation of the deformable member 144 in the front-rear direction of the seat allows the tilt of the back side frame 121 toward the front of the seat, but the deformable member 144 is compressed in the front-rear direction of the seat. Therefore, the tilt of the back side frame 121 toward the front of the seat may be allowed.

  In the example shown in FIG. 6, the first end portion 144 a of the deformable member 144 joined to the base bracket 142 by the engagement pin 145 is disposed on the front side of the seat, and the deformable member joined to the back bracket 143 by the engagement pin 146. A second end portion 144b of 144 is disposed on the seat rear side.

  In this case, when a tensile load exceeding a predetermined value is applied to the shoulder belt 105c and the stress acting on the deformable member 144 exceeds the yield stress of the deformable member 144, as shown in FIG. The sheet is plastically compressed in the longitudinal direction. When the deformable member 144 is compressed, the back side frame 121 is allowed to tilt toward the front of the seat, and the back side frame 121 tilts together with the upper body of the occupant toward the front of the seat. Thereby, the impact applied to the upper body of the occupant restrained by the shoulder belt 105c is alleviated.

  FIGS. 8 to 11 show other examples of the vehicle seat for explaining the embodiment of the present invention. The vehicle seat of this example is different from the vehicle seat 101 described above in the configuration of the connecting portion that connects the pair of back side frames of the seat back to the pair of cushion side frames of the seat cushion, and is an element common to the vehicle seat 101. The description is omitted or simplified by attaching a common reference numeral.

  The connecting portion 226 that connects the back side frame 121 to the cushion side frame 111 so as to be tiltable in the front-rear direction of the seat has a force limiter portion 231, and the force limiter portion 231 includes a base bracket 242 and a deformation member 244. It is configured to include.

  The base bracket 242 is disposed so as to overlap the back side frame 121 side of the rear end portion 111 a of the cushion side frame 111 connected to the back side frame 121. The base bracket 242 is joined to a reclining device 109 interposed between the connecting portion 226 and the cushion side frame 111. When the reclining device 109 is in a locked state, the cushion side frame is interposed via the reclining device 109. 111 is fixed.

  The base bracket 242 is provided with at least one engagement pin 245 that penetrates the lower end portion 121a of the back side frame 121 connected to the cushion side frame 111. In the illustrated example, the base bracket 242 serves as a tilt shaft of the back side frame 121. Four engagement pins 245 are provided on the circumference around the rod 129 at intervals in the circumferential direction. When the base bracket 242 is fixed to the cushion side frame 111 via the reclining device 109 in the locked state, these engagement pins 245 are also fixed to the cushion side frame 111.

  Further, the base bracket 242 is joined with a collar 147 disposed on the outer periphery of the rod 129 so as to be coaxial with the rod 129 serving as the tilting axis of the back side frame 121, and the sliding portion 150 of the back side frame 121 is connected to the color 147. 147 and a washer 148 attached to the collar 147 are slidably supported.

  The deformable member 244 is a disk-shaped member made of a plastically deformable metal material, and is disposed to overlap the opposite side of the lower end portion 121a of the back side frame 121 from the cushion side frame 111 side, and the back side frame 121. It is arranged coaxially with the rod 129 that becomes the tilting axis of and is joined to the backside frame 121.

  The deformation member 244 is provided with an engagement hole 244a that accommodates one end of an engagement pin 245 that is arranged to protrude to the opposite side of the cushion side frame 111 side of the lower end 121a of the back side frame 121, In the illustrated example, four engagement holes 244a having the same number as the engagement pins 245 are provided on the circumference around the rod 129 at intervals in the circumferential direction.

  The engagement hole 244a is formed to extend in an arc shape around the rod 129, and the width of one end portion of the engagement hole 244a is formed larger than the diameter of the engagement pin 245, and the other end of the engagement hole 244a is formed. The end has a width smaller than the diameter of the engagement pin 245. The engagement pin 245 is accommodated in the wide end of the engagement hole 244a. Although not shown, the through hole of the back side frame 121 through which the engagement pin 245 passes is also formed to extend in an arc shape around the rod 129, and the width of the through hole of the back side frame 121 is The diameter of the engaging pin 245 is larger than the entire length.

  When the occupant leans against the seat back 103, a load that tilts the back side frame 121 toward the rear of the seat is applied to the back side frame 121. This load is borne by the contact between the engagement pin 245 and the end face of the wide end of the engagement hole 244a. Thereby, the tilt of the back side frame 121 toward the rear of the seat is prevented.

  In the event of a vehicle collision or the like, a tensile load is applied to the shoulder belt 105c (see FIG. 1) of the seat belt 105 that restrains the upper body of an occupant who falls to the front of the seat due to inertia to the seat back 103, and the shoulder belt 105c The back side frame 121 provided with the shoulder bracket 106c to be moored is loaded with a load corresponding to a tensile load applied to the shoulder belt 105c and tilting the back side frame 121 toward the front of the seat. .

  When the back side frame 121 is tilted toward the front of the seat, the deformable member 244 joined to the back side frame 121 is also rotated around the rod 129 serving as the tilt axis of the back side frame 121. As the deformable member 244 rotates, the engagement pin 245 is relatively moved from the wide end portion of the engagement hole 244a toward the narrow end portion side. Since the width of the narrow end portion of the engagement hole 244a is smaller than the diameter of the engagement pin 245, the engagement pin 245 interferes with both side surfaces of the narrow end portion of the engagement hole 244a. As a result, a load that tilts the back side frame 121 toward the front of the seat is applied to the deformation member 244.

  When the tensile load applied to the shoulder belt 105c is relatively small, stress acting on the deformation member 244 that interferes with the engagement pin 245 on both side surfaces of the narrow end portion of the engagement hole 244a is deformed. When the yield stress is less than 244, the load transmitted to the deformation member 244 is borne by the rigidity of the deformation member 244. Thereby, the tilt of the back side frame 121 toward the front of the seat is prevented.

  On the other hand, a tensile load exceeding a predetermined value is applied to the shoulder belt 105c, and stress acting on the deformation member 244 due to interference between the engagement pin 245 and both side surfaces of the narrow end portion of the engagement hole 244a is applied to the deformation member 244. When the yield stress is exceeded, plastic deformation occurs in the deformable member 244 as shown in FIG. 12, and both side surfaces of the narrow end portion of the engagement hole 244a that interferes with the engagement pin 245 are crushed. As both side surfaces of the narrow end portion of the engagement hole 244a are crushed, the engagement pin 245 enters deep into the narrow end portion of the engagement hole 244a, and the seat of the back side frame 121 Tilt toward the front is allowed, and the back side frame 121 tilts toward the front of the seat together with the upper body of the occupant. At that time, energy is absorbed by plastic deformation of the deformable member 244. Thereby, the impact applied to the upper body of the occupant restrained by the shoulder belt 105c is alleviated.

  As the back side frame 121 tilts toward the front of the seat, the engagement pin 245 that has entered deep into the narrow end of the engagement hole 244a hits the end surface of the narrow end of the engagement hole 244a. After the contact, the engagement pin 245 contacts the end surface of the narrow end portion of the engagement hole 244a, the tilt of the back side frame 121 toward the front of the seat is prevented. Thereby, it is avoided that the deformation member 244 is broken due to excessive crushing on both side surfaces of the narrow end portion of the engagement hole 244a.

  Although not shown, the connecting portion that connects the cushion side frame 112 and the back side frame 122 also has a force limiter portion, and the force limiter portion of this connecting portion is the same as the force limiter portion 231 of the connecting portion 226. Composed.

  In the vehicle seat configured as described above, since the left and right shoulders of the occupant are supported by the pair of shoulder belts 105c and 105d, the upper body of the occupant leans to the left or right side during an oblique collision. The upper body of the occupant can be sufficiently restrained. The force limiter portion is provided at both the connecting portion 226 of the back side frame 121 mooring the shoulder belt 105c and the connecting portion of the back side frame 122 mooring the shoulder belt 105d. Even if the upper body is tilted to the left or right side, the shoulder belts 105c and 105d can sufficiently restrain the upper body of the occupant as described above, and effectively reduce the impact by the force limiter. be able to. Thereby, the passenger | crew protection performance of a vehicle seat can be improved.

  FIGS. 13 to 15 show other examples of the vehicle seat for explaining the embodiment of the present invention. The vehicle seat of this example is different from the vehicle seat 101 described above in the configuration of the connecting portion that connects the pair of back side frames of the seat back to the pair of cushion side frames of the seat cushion, and is an element common to the vehicle seat 101. The description is omitted or simplified by attaching a common reference numeral.

  A connecting portion 326 that connects the back side frame 121 to the cushion side frame 111 so as to be tiltable in the front-rear direction of the seat has a force limiter portion 331, and the force limiter portion 331 includes a base bracket 342, a back bracket 343, It includes a shaft 344 as a deformable member.

  The base bracket 342 is disposed so as to overlap the back side frame 121 side of the rear end portion 111 a of the cushion side frame 111 connected to the back side frame 121. The base bracket 342 is joined to a reclining device 109 interposed between the connecting portion 326 and the cushion side frame 111. When the reclining device 109 is in a locked state, the cushion side frame is interposed via the reclining device 109. 111 is fixed.

  The shaft 344 is made of a plastically deformable metal material, and is disposed coaxially with the rod 129 outside the rod 129 that serves as the tilt axis of the back side frame 121. The shaft 344 is provided so as to penetrate the lower end portion 121a of the back side frame 121, and the first end portion 344a protruding to the cushion side frame 111 side of the back side frame 121 is joined to the base bracket 342. By fixing the bracket 342 to the cushion side frame 111 via the reclining device 109 in the locked state, the first end 344 a of the shaft 344 is also fixed to the cushion side frame 111. The second end 344b of the shaft 344 is fixed to the back side frame 121 via the back bracket 343.

  The back bracket 343 is formed in a cylindrical shape, and is disposed coaxially with the shaft 344 outside the shaft 344. A base end portion 343 a of the back bracket 343 is joined to the back side frame 121, and a distal end portion 343 b of the back bracket 343 is joined to the second end portion 344 b of the shaft 344. Thus, the second end 344b of the shaft 344 is fixed to the back side frame 121 via the back bracket 343.

  The base bracket 342 is formed with a long hole 342a that extends in an arc shape around the rod 129 that serves as a tilting axis of the back side frame 121. The back side frame 121 has an engagement pin that is accommodated in the long hole 342a. 346 is provided.

  When the occupant leans against the seat back 103, a load that tilts the back side frame 121 toward the rear of the seat is applied to the back side frame 121. This load is borne by the contact between the engagement pin 346 and the end face of the elongated hole 342a on the seat rear side, and the tilt of the back side frame 121 toward the seat rear is prevented.

  At the time of a vehicle collision or the like, a tensile load is applied to the shoulder belt 105c of the seat belt 105 that restrains the upper body of the occupant who falls to the front of the seat due to inertia to the seat back 103, and the shoulder bracket 106c that anchors the shoulder belt 105c. A load corresponding to a tensile load applied to the shoulder belt 105c and tilting the back side frame 121 toward the front of the seat is applied to the back side frame 121 provided with. This load is a shaft 344 as a torque that causes twisting of the shaft 344 in which the first end 344 a is fixed to the cushion side frame 111 and the second end 344 b is fixed to the back side frame 121. To be loaded.

  When the tensile load applied to the shoulder belt 105c is relatively small and the torque acting on the shaft 344 is less than the torsional yield torque of the shaft 344, the load applied to the shaft 344 is the shaft 344. Is borne by the rigidity of the. Thereby, the tilt of the back side frame 121 toward the front of the seat is prevented.

  On the other hand, when a tensile load exceeding a predetermined value is applied to the shoulder belt 105c and the torque acting on the shaft 344 exceeds the torsional yield torque of the shaft 344, the shaft 344 is plastically twisted. Then, the shaft 344 is twisted, and the tilt of the back side frame 121 toward the front of the seat is allowed, and the back side frame 121 tilts together with the upper body of the occupant toward the front of the seat. At that time, energy is absorbed by plastic deformation of the shaft 344. Thereby, the impact applied to the upper body of the occupant restrained by the shoulder belt 105c is alleviated.

  As the back side frame 121 tilts toward the front of the seat, the engagement pin 346 moves through the long hole 342a of the base bracket 342 and comes into contact with the end surface of the long hole 342a on the front side of the seat. After the engagement pin 346 contacts the end surface of the long hole 342a on the seat front side, the back side frame 121 is prevented from tilting toward the seat front. Thereby, it is avoided that the shaft 344 is excessively twisted and broken.

  Although not shown, the connecting portion that connects the cushion side frame 112 and the back side frame 122 also has a force limiter portion, and the force limiter portion of this connecting portion is the same as the force limiter portion 331 of the connecting portion 326. Composed.

  In the vehicle seat configured as described above, since the left and right shoulders of the occupant are supported by the pair of shoulder belts 105c and 105d, the upper body of the occupant leans to the left or right side during an oblique collision. The upper body of the occupant can be sufficiently restrained. The force limiter portion is provided at both the connecting portion 326 of the back side frame 121 mooring the shoulder belt 105c and the connecting portion of the back side frame 122 mooring the shoulder belt 105d. Even if the upper body is tilted to the left or right side, the shoulder belts 105c and 105d can sufficiently restrain the upper body of the occupant as described above, and effectively reduce the impact by the force limiter. be able to. Thereby, the passenger | crew protection performance of a vehicle seat can be improved.

  Up to this point, the shoulder belt 105c has been wound up by the retractor 104c disposed on the backside frame 121 side, and the shoulder belt 105d has been described as wound by the retractor 104d disposed on the backside frame 122 side. As shown, the pair of shoulder belts 105c and 105d may be overlapped and wound by a common retractor 104.

DESCRIPTION OF SYMBOLS 101 Vehicle seat 102 Seat cushion 103 Seat back 104 Retractor 104c Retractor 104d Retractor 105 Seat belt 105a Wrap belt 105b Wrap belt 105c Shoulder belt 105d Shoulder belt 106c Shoulder bracket 106d Shoulder bracket 107 Buckle 109 Reclining device 110 Cushion frame 111 Cushion side frame 111a Rear end portion 112 Cushion side frame 113 Cross frame 120 Back frame 121 Back side frame 121a Lower end portion 122 Back side frame 123 Upper cross frame 124 Lower cross frame 125 Retractor fixing bracket 126 Connecting portion 127 Connecting portion 129 Rod 131 Force limiter Portion 142 Base bracket 142a Long hole 143 Back bracket 143a Recess 144 Deformation member 144a First end 144b Second end 145 Engagement pin 147 Collar 148 Washer 226 Connection portion 231 Force limiter 242 Base bracket 244 Deformation member 244a engaging hole 245 engaging pin 326 connecting portion 331 force limiter portion 342 base bracket 342a long hole 343 back bracket 343a base end portion 343b distal end portion 344 shaft (deformable member)
344a First end portion 344b Second end portion 346 Engagement pin

Claims (8)

Seat cushions,
A seat back having a pair of side frames arranged at intervals in the seat width direction;
A pair of connecting parts for connecting each of the pair of side frames to the frame of the seat cushion so as to be tiltable in the seat longitudinal direction;
A seat belt having a pair of shoulder belts that are moored to each of the pair of side frames and support left and right shoulders of the occupant;
With
Each of the pair of connecting portions includes a deforming member that is plastically deformed when a tensile load exceeding a predetermined value is applied to the shoulder belt moored to the side frame supported by the connecting portion. A vehicle seat having a force limiter portion that allows the side frame to tilt toward the front of the seat by plastic deformation of the side frame. The vehicle seat according to claim 1,
The deformable member is disposed at a first end fixed to the seat cushion frame and spaced from the first end in the front-rear direction of the seat and fixed to the side frame of the seat back. The vehicle seat has a second end portion that is extended and compressed in the front-rear direction of the seat as the side frame tilts toward the front of the seat. The vehicle seat according to claim 2,
The force limiter unit further includes a base bracket fixed to the frame of the seat cushion, and a back bracket disposed with the deformable member interposed between the base bracket and joined to the side frame. Including
The vehicle seat in which the first end of the deformable member is joined to the base bracket and the second end is joined to the back bracket. The vehicle seat according to claim 3,
The base bracket is provided with a long hole extending along the track of the second end portion of the deformable member when the side frame tilts toward the front of the seat,
The second end portion of the deformable member is provided with an engagement pin that is received in the elongated hole of the base bracket,
A vehicular seat in which extension or compression of the deformable member accompanying the tilt of the side frame toward the front of the seat is regulated by contact between the engagement pin and one end face of the elongated hole. The vehicle seat according to claim 1,
The force limiter part further includes at least one engagement pin fixed to the frame of the seat cushion,
The deformable member is joined to the side frame,
The deformable member includes an engagement hole that extends in an arc shape around the tilt axis of the side frame and has one end narrower than the other end, and has a relatively wide end. At least one engagement hole for accommodating the engagement pin in the portion;
The engagement pin is moved from the wide end portion side of the engagement hole to the narrow end portion side with the inclination of the side frame toward the seat front,
The deformable member is a vehicle seat in which a side surface on a narrow end portion side of the engagement hole is crushed by the engagement pin as the side frame tilts toward the front of the seat. The vehicle seat according to claim 5,
Crushing of the side surface on the narrow end portion side of the engagement hole due to the tilt of the side frame toward the front of the seat by the contact between the engagement pin and the end surface on the narrow end portion side of the engagement hole Vehicle seats that are restricted. The vehicle seat according to claim 1,
The deformable member is a shaft provided coaxially with the tilt axis of the side frame, a first end fixed to the frame of the seat cushion, and a second end fixed to the side frame. A vehicle seat that is twisted about a tilt axis of the side frame as the side frame tilts toward the front of the seat. The vehicle seat according to claim 7,
The force limiter part further includes a base bracket fixed to the frame of the seat cushion,
The base bracket is formed with a long hole extending in an arc shape around the tilt axis of the side frame,
The side frame is provided with an engagement pin accommodated in the elongated hole,
A vehicle seat in which torsion of the shaft associated with tilting of the side frame toward the front of the seat is regulated by contact between the engagement pin and one end surface of the elongated hole.

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