JP2006168627A - Vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle seat with a simple constitution capable of appropriately adjusting a gap between an occupant head and a head rest, reducing load of a neck part by supporting the occupant head by forwardly moving the head rest in collision from a rear side of the vehicle and easily restoring the head rest to the original position after the collision. <P>SOLUTION: In usual seating, the load applied to a seat back frame 8 is transmitted to a torque limiter 20 through a cable 22 and the seat back frame 8 is retained to a side frame 6 while maintaining predetermined torque by the torque limiter 20. Whereas, when the load of a predetermined value or more is inputted from a rear side of the vehicle, a waist part pushes a lower part of the seat back frame and release of torque is performed through the cable 22 by the movement to the rear side of the human body. Thereby, the seat back frame 8 is pivoted around a rotation hinge 26 and the head rest 10 is forwardly moved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a vehicle seat that can prevent whiplash of an occupant when a collision is caused from the rear of the vehicle.

  A vehicle seat is usually provided with a headrest above the seat back, and when the occupant is seated, there is a predetermined gap between the occupant's head and the headrest, and the vehicle seat collides from the rear of the vehicle. The body moves forward while the head remains behind, which can cause a load on the neck and cause whiplash.

  Although it is possible to minimize the damage by reducing the gap between the head and the headrest, the head always touches the headrest even during normal use, or moves the head slightly to interfere with the headrest. There is a problem that it feels uncomfortable.

  In addition, the headrest connected to the pressure receiving portion is swingably attached and is always urged rearward by a coil spring, and in the event of a collision from the rear of the vehicle, the load input to the pressure receiving portion resists the urging force of the coil spring. It has also been proposed to move the headrest forward, but after the collision, the headrest that contacts the head immediately returns to its original position, so there is still a problem that the neck is loaded (for example, (See Patent Document 1).

  Therefore, a mechanism has also been proposed in which the headrest is moved forward at the time of a collision from the rear of the vehicle and further held at that position (for example, see Patent Document 2 or 3).

JP 2001-39194 A JP 2001-163097 A JP 2002-274240 A

  In the vehicle seat described in Patent Document 2, a ratchet mechanism is employed as a mechanism for holding the headrest that has moved forward at that position in the event of a collision from the rear of the vehicle, but moved forward after the collision. The headrest could not be returned to its original position.

  The vehicle seat described in Patent Document 3 similarly employs a ratchet mechanism, but is provided with a release means for returning the headrest moved forward after the collision to the original position. However, there is a problem that the mechanism is complicated and the cost is increased.

  The present invention has been made in view of such problems of the prior art, and the gap between the occupant's head and the headrest can be appropriately adjusted, and the headrest can be moved forward in the event of a collision from the rear of the vehicle. An object of the present invention is to provide a vehicular seat having a simple configuration that can reduce the load on the neck by supporting an occupant's head and can easily return the headrest to its original position after a collision.

  In order to achieve the above object, the invention according to claim 1 is a seat cushion, a seat back that is tiltably attached to the seat cushion, and an upper portion of the seat back. A vehicle seat having a headrest, comprising: a pair of side frames attached to a seat cushion frame; and a seat back frame attached to the side frame via a rotation hinge, wherein any of the side frame and the seat back frame The torque maintaining means attached to one of the side frame and the other of the side frame and the seat back frame are connected via a load transmission member, and during normal seating, the predetermined torque transmitted via the load transmission member is Maintaining the seat back frame by the torque maintaining means On the other hand, when a load of a predetermined value or more is input from the rear of the vehicle, the waist part pushes the lower portion of the seat back frame by the movement of the human body and the predetermined transmission via the load transmission member. By releasing the torque, the seat back frame swings around the rotary hinge, and the headrest is moved forward.

  According to a second aspect of the present invention, there is provided a vehicle seat including: a seat cushion; a seat back that is tiltably attached to the seat cushion; and a headrest attached to an upper portion of the seat back. A pair of side frames attached to the frame, and a seat back frame attached to the side frame via a rotary hinge. During normal seating, the seat back frame is held on the side frame, and the seat back By manually swinging the frame around the rotary hinge, the front / rear position of the headrest is set to be changeable. On the other hand, when a load greater than a predetermined value is input from the rear of the vehicle, the human body moves backward. By pressing the lower part of the seat back frame, the waist Swings around the seat back frame is the rotating hinge, characterized in that so as to move the headrest forward.

  Further, the invention according to claim 3 is the invention according to claim 2, wherein torque maintaining means attached to one of the side frame and the seat back frame, the other of the side frame and the seat back frame, Are connected via a load transmission member.

  According to a fourth aspect of the present invention, the load transmission member is constituted by a cable having an outer cable and an inner cable that is slidably mounted in the outer cable, and the torque maintaining means is constituted by a torque limiter. The torque limiter and the lower end portion of the seat back frame are connected via the cable.

  According to a fifth aspect of the present invention, the torque limiter includes an outer casing, an inner casing rotatably accommodated in the outer casing, and a shaft member rotatably mounted in the inner casing. And a coil spring wound around the outer peripheral surface of the shaft member in a press-contact state and having one end locked to the inner casing, and holding an end portion of the outer cable with the outer casing, When the end is held by the inner casing and the coil spring is held on the outer peripheral surface of the shaft member during normal seating to maintain the predetermined torque, while a load greater than a predetermined value is input from the rear of the vehicle The coil spring via the inner cable and the inner casing Loosening is characterized in that so as to release the predetermined torque.

  According to a sixth aspect of the invention, an adjustment member is attached to the torque limiter, the inner casing is rotated by the adjustment member, and the seat back frame is swung through the inner cable, whereby the headrest is It is characterized in that the front / rear position of can be changed.

  According to a seventh aspect of the present invention, the seat back frame has two lower end portions, each lower end portion is connected to the torque limiter via a single cable, and the inner cable constituting the cable is provided. An elastic means is provided for connecting each lower end portion from the front and urging each lower end rearward.

  In the invention according to claim 8, the seat back frame has two lower ends, and each lower end is connected to the torque limiter via two cables to constitute the two cables. Two inner cables are connected to the respective lower ends from the front and rear, respectively.

  The invention according to claim 9 is characterized in that the torque maintaining means includes a torque limiter attached to the seat back frame and a one-way clutch that maintains a predetermined torque only in one direction. To do.

  The invention according to claim 10 is characterized in that the load transmitting member is constituted by a swingable swinging link for connecting the torque maintaining means and the side frame.

  According to the present invention, the seat back frame is attached to the side frame via the rotary hinge, the torque maintaining means attached to one of the side frame and the seat back frame, and the other side of the side frame and the seat back frame is loaded. It is connected via a transmission member, and during normal seating, the seat back frame is held by the side frame while maintaining a predetermined torque against the load applied to the seat back frame by the torque maintaining means, while a load greater than a predetermined value from the rear of the vehicle. Is input through the load transmission member, the seat back frame swings around the rotary hinge, and the headrest moves forward to support the occupant's head. As a result, the load on the neck can be reduced.

  Further, since the seat back frame can be swung via the cable by the adjusting member provided in the torque limiter, the gap between the occupant's head and the headrest can be adjusted as appropriate, and the headrest can be restored to the original after the collision. It can be easily returned to the position.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a frame structure F of a vehicle seat according to the present invention having a seat cushion and a seat back attached to the seat cushion so as to be tiltable, and a seat cushion frame 2 attached to a vehicle body floor, and a seat A pair of left and right side frames 6 attached to the cushion frame 2 via a reclining adjuster 4 so as to be tiltable, a seat back frame 8 attached to the side frame 6, and a headrest 10 attached to an upper portion of the seat back frame 8. It has.

  The left and right reclining adjusters 4 are connected via a connecting shaft 12, and by operating an operating lever 14 attached to one of the reclining adjusters 4, the left and right reclining adjusters 4 are interlocked so that the side frame 6 is in a desired state. Set to an angle.

  The reclining adjuster 4 includes a lower bracket 16 attached to the seat cushion frame 2 and an upper bracket 18 attached to the lower bracket 16 so as to be tiltable. However, the reclining adjuster 4 is not the main point of the present invention. Detailed description thereof is omitted.

Embodiment 1 FIG.
A lower end portion of the side frame 6 is attached to the upper bracket 18 of the reclining adjuster 4, and a guide hole into which a bolt (described later) attached near the lower end portion of the seat back frame 8 is loosely inserted in the side frame 6. 6a is formed, and a rotary hinge insertion hole 6b is formed in the upper part of the side frame 6. In addition, the guide hole 6a is formed in the circular-arc long hole shape centering on the rotation hinge insertion hole 6b.

  Further, a torque limiter 20 is attached to the inner side surface of the intermediate portion between the guide hole 6a and the rotary hinge insertion hole 6b in one of the left and right side frames 6, and the inner cables of the two cables 22 led out from the torque limiter 20 Ends (described later) are respectively connected from the front to the left and right lower ends of the seat back frame 8, and an outer cable (described later) that slidably accommodates the inner cable is the left and right lower ends of the seat back frame 8. It is attached to the seat cushion frame 2 located in the section.

  On the other hand, the seat back frame 8 to which the headrest 10 is attached is formed in a substantially inverted U shape, and the guide hole 6a is formed in the seat back frame 8 facing the guide hole 6a formed in the side frame 6. A first bolt 24 projecting toward the seat frame is attached to the seat back frame 8 facing the rotational hinge insertion hole 6b formed in the side frame 6, and serves as a rotational hinge projecting toward the rotational hinge insertion hole 6b. A second bolt 26 is attached.

  Moreover, both ends of a plurality of S-shaped springs 28 are fixed to both side portions of the seat back frame 8, and a pressure receiving plate 29 facing the seated person's waist is interposed between the two S-shaped springs 28 positioned below. Both ends of the seat back frame 8 are fixed to both side portions of the seat back frame 8, similarly to the S-shaped spring 28. The S-shaped spring 28 is in contact with the back surface of a pad material (not shown) that covers the seat back frame 8, whereas the pressure receiving plate 29 is separated from the back surface of the pad material, so that a person sits down. For the first time, the pressure receiving plate 29 comes into contact with the pad material.

  Further, one end of a coil spring (elastic means) 30 is locked to the left and right lower ends of the seat back frame 8, and the other end of the coil spring 30 is a bracket attached to the left and right rear ends of the seat cushion frame 2. The lower end portions of the seat back frame 8 are always urged rearward.

  FIG. 2 shows the torque limiter 20 and the cable 22. The cable 22 includes an outer cable 22a and an inner cable 22b that is slidably attached in the outer cable 22a.

  As shown in FIGS. 2 to 5, the torque limiter 20 includes a pair of outer casings 32 having a symmetrical shape and an inner casing 34 that is rotatably accommodated within the outer casing 32 within a predetermined angular range. And. The outer casing 32 is formed with an outer cable holding portion 32a protruding outward, and the inner casing 34 is similarly formed with an inner cable holding portion 34b protruding outward from the cup-shaped main body 34a. ing.

  As shown in FIG. 2, when the pair of outer casings 32 is assembled, a guide groove 32b in which the inner cable holding portion 34b can slide is formed in a part thereof, and the length of the guide groove 32b allows the inner casing to be slid. The rotation range of 34 is determined, and is set to approximately 90 degrees in the present embodiment.

  The outer casing 32 also includes a circular hole 32c formed at the center thereof and a regular hexagonal concave portion 32d formed inside the circular hole 32c. A regular hexagonal head 36a of the shaft 36 is inserted. A cylindrical portion 36b is formed integrally with the head portion 36a, and the cylindrical portion 36b is loosely inserted into a cup-shaped outer shaft 38. A circular hole 38a is formed at the center of the bottom wall of the outer shaft 38, and a plurality of (for example, three) arc-shaped slits 38b are formed around the circular hole 38a at predetermined intervals on a concentric circle. An arc-shaped recess 38c is formed between adjacent slits 38b in the cylindrical side wall of the outer shaft 38, and one elastic body is provided between each arc-shaped recess 38c and the cylindrical portion 36b of the inner shaft 36. 40 and two pins 42 arranged on both sides thereof are interposed. The elastic body 40 and the pin 42 are cylindrical and have substantially the same shape, and the diameters thereof are the inner peripheral surface excluding the concave portion 38c of the cylindrical side wall of the outer shaft 38 and the outer periphery of the cylindrical portion 36b of the inner shaft 36. The outer circumferential surface of the cylindrical portion 36 b of the inner shaft 36 is a rolling surface of the elastic body 40 and the pin 42.

  A coil spring 44 is wound around the outer peripheral surface of the outer shaft 38 in a pressure contact state, and one end 44a of the coil spring 44 is bent and formed on the bottom wall of the cup-shaped body 34a of the inner casing 34. The retaining hole 34c and the engaging groove 34d formed in the inner peripheral surface of the cylindrical side wall of the cup-shaped main body 34a are fitted.

  Further, one end of the operation shaft 46 is loosely inserted into a circular hole 34e formed in the center of the bottom wall of the inner casing 34, and an insertion shaft 46a is formed at the center of the other end of the operation shaft 46. The same number of arc-shaped protrusions 46b as the arc-shaped slits 38b of the outer shaft 38 are formed around the insertion shaft 46a at a predetermined interval. The arcuate protrusion 46b has the same curvature as the arcuate slit 38b of the outer shaft 38, the width of the arcuate protrusion 46b is set smaller than the width of the arcuate slit 38b, and the length of the arcuate protrusion 46b is a circle. The insertion shaft 46a of the operation shaft 46, which is set to be shorter than the length of the arc-shaped slit 38b and one end of which is loosely inserted into the center hole 34e of the inner casing 34, is loosely inserted into the center hole 38a of the outer shaft 38, and the arc-shaped protrusion 46b. Is loosely inserted into the arc-shaped slit 38 b of the outer shaft 38.

  The outer cable 22 a is held by the outer cable holding portion 32 a of the outer casing 32, and the inner cable 22 b is held by the inner cable holding portion 34 b of the inner casing 34.

  In the torque limiter 20 having the above-described configuration, when the operation shaft 46 is rotated, the arc-shaped protrusion 46b presses the elastic body 40 and the pin 42, and the elastic body 40 and the pin 42 become the rolling surface of the inner shaft 36 (of the cylindrical portion 36b). The outer shaft 38 is rotated, and the outer shaft 38 rotates around the inner shaft 36. Further, a coil spring 44 is pressed against the outer peripheral surface of the outer shaft 38, and one end of the coil spring 44 is fitted into the locking hole 34c of the inner casing 34. Therefore, the inner casing 34 is also integrated with the outer shaft 38. The inner cable 22b held by the inner cable holding portion 34b is moved forward and backward (in / out) with respect to the outer cable 22a.

  As described above, since the two inner cables 22b are respectively connected to the left and right lower ends of the seat back frame 8, a load on the seat occupant is applied to the inner cable 22b to some extent, and the inner casing 34 tries to rotate. Torque is transmitted to the outer shaft 38 via the coil spring 44. Under normal load, one of the two pins 42 arranged on both sides of the elastic body 40 is the inner periphery of the cylindrical side wall of the outer shaft 38. The outer shaft 38 does not rotate because it enters the gap between the surface and the rolling surface of the inner shaft 36 and becomes locked.

  When a large load is applied to the pressure receiving plate 29 attached to the seat back frame 8 due to a rear collision or the like, a large torque is transmitted to the inner casing 34 via the inner cable 22b. As a result, rotational torque in the direction of arrow A is applied to the end of the coil spring 44 fitted in the locking hole 34c of the inner casing 34, and the coil spring 44 pressed against the outer shaft 38 is loosened. The casing 34 slides around the outer shaft 38 together with the coil spring 44 to release the torque.

  When attaching the seat back frame 8 to the side frame 6, the first bolt 24 is inserted into the guide hole 6 a of the side frame 6, and the second bolt 26 is inserted into the rotary hinge insertion hole 6 b of the side frame 6. . At this time, the end of the operation shaft 46 loosely inserted into the inner casing center hole 34e of the torque limiter 20 is an operation shaft insertion hole 6c formed between the guide hole 6a of the side frame 6 and the rotary hinge insertion hole 6b. The torque limiter 20 is fixed to the side frame 6, and an adjustment dial 48 as an adjustment member is attached to the end of the operation shaft 46. Thereafter, nuts 50 and 52 are screwed onto the first and second bolts 24 and 26.

  FIG. 6 shows the state at this time, and the first bolt 24 is located at the front end of the guide hole 6a.

  In the vehicle seat according to the present invention having the above-described configuration, the torque limiter 20 fixed to the side frame 6 is connected to both lower ends of the seat back frame 8 via the cable 22. The seat back frame 8 is held by the side frame 6 while maintaining a predetermined torque transmitted through the torque limiter 20, and the load on the upper body of the passenger is supported by the seat back frame 8 in this state. Yes. Moreover, the headrest 10 attached to the upper part of the seat back frame 8 is separated from the passenger's head at a predetermined interval.

  In this state, when the adjustment dial 48 of the torque limiter 20 is appropriately rotated, the operation shaft 46 is rotated within a predetermined angular range, so that the inner casing 34 is rotated with respect to the outer casing 32 as described above, and the inner cable 22b is It slides with respect to the outer cable 22a. Further, since the inner cable 22b is connected to both lower ends of the seat back frame 8, the seat back frame 8 rotates around the rotary hinge (second bolt 26), so that the front and rear positions of the headrest 10 are changed. Thus, the separation distance of the headrest 10 with respect to the head of the occupant can be adjusted as appropriate.

  On the other hand, when a load of a predetermined value or more is input from the rear due to a rear collision or the like, the human body is relatively pressed against the seat back. At this time, the waist part pushes the pressure receiving plate 29 rearward due to the backward movement of the human body, so that the end of the coil spring 44 rotates in the direction of arrow A via the inner cable 22b and the inner casing 34 as described above. Since the torque is applied and the coil spring 44 pressed against the outer shaft 38 is loosened, the inner casing 34 slides around the outer shaft 38 together with the coil spring 44 to release the torque. Therefore, the seat back frame 8 swings using the second bolt 26 as a rotary hinge, and the headrest 10 moves toward the passenger's head to support the passenger's head.

  At this time, the first bolt 24 loosely inserted into the guide hole 6a of the side frame 6 moves from the front end portion of the guide hole 6a shown in FIG. 6 to the rear end portion of the guide hole 6a shown in FIG.

  In the above embodiment, the torque limiter 20 acts as a torque maintaining means, and the two cables 22 act as load transmitting members.

  In the above embodiment, the other ends of the two inner cables whose one ends are connected to the torque limiter 20 are connected from the front of the seat back frame 8, and both lower ends of the seat back frame 8 are always rearward. The coil spring 30 is provided to be biased, but two cables are extended between the torque limiter 20 and each lower end portion of the seat back frame 8, and one inner cable is connected to the lower end of the seat back frame 8 from the front. The other inner cable may be connected to the lower end of the seat back frame 8 from the rear.

Embodiment 2. FIG.
Next, regarding the vehicle seat according to the second embodiment of the present invention, only differences from the above-described first embodiment will be described with reference to FIGS. 8 to 10.

  As shown in FIGS. 8 and 9, a lower end portion of the side frame 6 is attached to the upper bracket 18 of the reclining adjuster 4, and the pair of side frames 6 planted on the swing link 54 is attached to the side frame 6. Of the pins 56 and 58, a long hole-shaped guide hole 6a into which the rear pin 58 is loosely inserted is formed. Unlike the first embodiment, the guide hole 6a is not formed in an arc shape centering on the rotary hinge insertion hole 6b. In the present embodiment, the guide hole 6a is substantially parallel to the front edge of the side frame 6. It extends to.

  A one-way hinge 60 is attached to the inner surface of the seat back frame 8 in the vicinity of the guide hole 6a in one of the left and right side frames 6, and a circular hole 8a concentric with the center hole 60a is formed in the seat back frame 8. Is formed. Of the pair of pins 56 and 58 planted in the swing link 54 described above, the front pin 56 is inserted into the circular hole 8a.

  The one-way hinge 60 employed in the present embodiment is a hinge that combines the torque limiter employed in the first embodiment and a known one-way clutch. The torque limiter generates torque in both directions and rotates when the limit is exceeded. On the other hand, the one-way clutch does not rotate in one direction (locked state), and rotates freely (is idle) without generating torque in the other direction. That is, during normal seating, a predetermined torque transmitted through the swing link 54 is maintained by the one-way hinge 60 to hold the seat back frame 8 on the side frame 6 and attached to the seat back frame 8 by a rear collision or the like. When a large load is applied to the pressure receiving plate 29, the swing link 54 swings against the resistance (predetermined torque) of the one-way hinge 60, but the seat back frame 8 is returned to its original position after the rear impact. In this case, no resistance is generated.

  More specifically, during normal seating, as shown in FIGS. 8A and 10A, the pin 58 behind the swing link 54 is positioned at the lower end of the guide hole 6a of the side frame 6. In this state, since the one-way hinge 60 maintains a predetermined torque, the load on the upper body of the occupant is supported by the seat back frame 8. Moreover, the headrest 10 attached to the upper part of the seat back frame 8 is separated from the passenger's head at a predetermined interval.

  On the other hand, when a load of a predetermined value or more is input from the rear due to a rear collision or the like, the human body is relatively pressed against the seat back. At this time, the lumbar part pushes the pressure receiving plate 29 backward due to the movement of the human body backward, so that it resists a predetermined torque of the one-way hinge 60 as shown in FIGS. 8 (b) and 10 (b). Then, the pin 58 of the swing link 54 moves from the lower end portion to the upper end portion along the guide hole 6a. As a result, the seat back frame 8 swings using the second bolt 26 as a rotary hinge, and the headrest 10 moves toward the passenger's head to support the passenger's head.

  As described above, the one-way hinge 60 does not generate resistance in the reverse direction due to the function of the one-way clutch. Therefore, after the rear impact, a load is applied to the upper portion of the seat back, or the lower portion of the seat back is moved forward. When the load is applied, the swing link 54 swings and the pin 58 moves from the upper end portion to the lower end portion along the guide hole 6a, so that the seat back can be tilted back to the state shown in FIG. Return to.

  In the present embodiment, the one-way hinge 60 acts as a torque maintaining means, and the swing link 54 acts as a load transmission member.

  The vehicle seat according to the present invention has a configuration in which the torque limiter 20 fixed to the side frame 6 and both lower ends of the seat back frame 8 are simply connected by two cables 22, and the headrest 10 at the time of rear collision is moved forward. It is possible to adjust the separation distance between the headrest 10 and the occupant's head while supporting the occupant's head by moving to the vehicle seat, which is useful as a vehicle seat that can prevent occupant whiplash with a simple configuration. It is. Further, with the configuration in which the one-way hinge 60 fixed to the seat back frame 8 and the side frame 6 are simply connected by the swing link 54, the headrest 10 is moved forward at the time of rear collision so as to support the head of the occupant. Therefore, it is useful as a vehicle seat that can prevent whiplash of the occupant with a simple configuration.

It is a disassembled perspective view of the vehicle seat concerning Embodiment 1 of this invention. It is a perspective view of the torque limiter attached to the vehicle seat of FIG. FIG. 3 is an exploded perspective view of the torque limiter of FIG. 2. It is a disassembled perspective view which shows a part of torque limiter of FIG. FIG. 3 is a longitudinal sectional view of the torque limiter of FIG. 2. It is a side view which shows the normal seating state of the vehicle seat of FIG. It is a side view which shows the state at the time of the rear collision of the vehicle seat of FIG. The vehicle seat concerning Embodiment 2 of this invention is shown, (a) is a perspective view which shows a normal seating state, (b) is a perspective view which shows the state at the time of a rear collision. It is a disassembled perspective view which shows the rocking | fluctuation mechanism provided in the vehicle seat of FIG. FIG. 10 shows the swing mechanism of FIG. 9, (a) is a side view showing a normal seating state, and (b) is a side view showing a state at the time of rear collision.

Explanation of symbols

2 Seat cushion frame, 4 Reclining adjuster,
6 side frame, 6a guide hole, 6b rotary hinge insertion hole,
6c Operation shaft insertion hole, 8 Seat back frame, 8a Circular hole,
10 headrest, 12 connecting shaft, 14 operation lever, 16 lower bracket,
18 Upper bracket, 20 Torque limiter, 22 Cable,
22a outer cable, 22b inner cable, 24 first bolt,
26 second bolt, 28 S-shaped spring, 29 pressure receiving plate, 30 coil spring,
31 Bracket, 32 Outer casing, 32a Outer cable holding part,
32b guide groove, 32c circular hole, 32d recess, 34 inner casing,
34a inner casing body, 34b inner cable holding part,
36 inner shaft, 36a inner shaft head, 36b cylindrical portion,
38 outer shaft, 38a circular hole, 38b slit,
38c arc-shaped recess, 40 elastic body, 42 pins, 44 coil spring,
44a Bending end of coil spring, 46 operation shaft, 46a insertion shaft,
46b Arc-shaped protrusion, 48 Adjustment dial, 50, 52 Nut,
54 swing link, 56, 58 pins, 60 one-way hinge,
60a Center hole, F frame structure.

Claims (10)

In a vehicle seat having a seat cushion, a seat back that is tiltably attached to the seat cushion, and a headrest attached to an upper portion of the seat back,
A torque maintaining means attached to one of the side frame and the seat back frame, comprising a pair of side frames attached to the seat cushion frame, and a seat back frame attached to the side frame via a rotary hinge And the other of the side frame and the seat back frame via a load transmission member, and during normal seating, a predetermined torque transmitted via the load transmission member is maintained by the torque maintaining means, and the seat is maintained. While a back frame is held on the side frame, when a load of a predetermined value or more is input from the rear of the vehicle, the lower back of the seat back frame pushes the lower part of the seat back frame by the movement of the human body, and the load is transmitted through the load transmitting member. The seat back frame is released by releasing the predetermined torque. Swings around the serial rotation hinge, a vehicle seat is characterized in that so as to move the headrest forward. In a vehicle seat having a seat cushion, a seat back that is tiltably attached to the seat cushion, and a headrest attached to an upper portion of the seat back,
A pair of side frames attached to the seat cushion frame, and a seat back frame attached to the side frame via a rotary hinge, and during normal seating, the seat back frame is held on the side frame, and By manually swinging the seat back frame around the rotary hinge, the front / rear position of the headrest is set to be changeable. On the other hand, when a load greater than a predetermined value is input from the rear of the vehicle, The seat for a vehicle is characterized in that the lower back of the seat back frame is pushed by the movement of the seat back so that the seat back frame swings about the rotary hinge and the headrest is moved forward.   The torque maintaining means attached to either one of the side frame and the seat back frame and the other of the side frame and the seat back frame are connected via a load transmission member. Vehicle seat.   The load transmission member is constituted by a cable having an outer cable and an inner cable slidably mounted in the outer cable, the torque maintaining means is constituted by a torque limiter, and the torque limiter and the seat back frame The vehicle seat according to claim 1 or 3, wherein a lower end portion is connected via the cable.   The torque limiter is in pressure contact with an outer casing, an inner casing rotatably accommodated in the outer casing, a shaft member rotatably mounted in the inner casing, and an outer peripheral surface of the shaft member. A coil spring wound at one end and locked to the inner casing, the end of the outer cable is held by the outer casing, and the end of the inner cable is held by the inner casing. When seated, the coil spring is held on the outer peripheral surface of the shaft member to maintain the predetermined torque, and when a load of a predetermined value or more is input from the rear of the vehicle, the coil spring is passed through the inner cable and the inner casing. Release the predetermined torque by loosening the coil spring The vehicle seat according to claim 4, characterized in that the so that.   An adjustment member is attached to the torque limiter, and the front / rear position of the headrest can be changed by rotating the inner casing by the adjustment member and swinging the seat back frame via the inner cable. The vehicle seat according to claim 4 or 5.   The seat back frame has two lower ends, each lower end is connected to the torque limiter via a single cable, and an inner cable constituting the cable is connected to the lower ends from the front, The vehicular seat according to any one of claims 4 to 6, wherein elastic means for urging the lower end portions backward is provided.   The seat back frame has two lower end portions, each lower end portion is connected to the torque limiter via two cables, and two inner cables constituting the two cables are respectively connected from the front and the rear. The vehicle seat according to any one of claims 4 to 6, wherein the vehicle seat is connected to each of the lower end portions.   2. The vehicle seat according to claim 1, wherein the torque maintaining unit includes a torque limiter attached to the seat back frame and a one-way clutch that maintains a predetermined torque only in one direction. The vehicle seat according to claim 9, wherein the load transmission member includes a swingable swing link that connects the torque maintaining means and the side frame.

Images