Safety device for vehicle seat

Abstract

Provided is a safety device for a vehicle seat, which can prevent a seat back from being twisted in the width direction when a collision occurs in a vehicle, and can appropriately restrain an occupant. A safety device for a vehicle seat for protecting an occupant seated on the vehicle seat includes a reclining mechanism capable of adjusting an angle of a seat back. The safety belt is configured to extend in a diagonal direction from an upper end portion of a first side in a width direction of the seat back toward a lower end of a second side opposite to the first side. Moreover, an adjusting device is arranged on a rotating shaft part which is an axis when the seat back is inclined, and the adjusting device can change the rotation amount of the first side and the second side of the seat back when the vehicle collides.

Description

Technical Field

[0001] The present invention relates to a safety device for a vehicle seat, and more particularly to a safety device for a vehicle seat equipped with a seat belt retractor and having an integrated retractor. Background Art

[0002] Automobiles have seat belts that restrain passengers in their seats. The mainstream seat belts are three-point seat belts that extend obliquely downward from the vicinity of one shoulder of the passenger and extend horizontally near the hip bone. In addition, recent automobiles have retractors that automatically rewind the seat belts immediately before and / or after a collision occurs.

[0003] Patent document 1 discloses a retractor-integrated automobile seat having a seat belt retractor in a seat back. Figure 1 As shown in FIG. 1A , the retractor-integrated seat has a structure in which a seatbelt retractor 12 is provided at the upper end of a seatback 10 , and an upper end 14 a of a seatbelt 14 extends from the upper portion of the shoulder of an occupant P. Since the retractor is located close to the shoulder of the occupant, the gap between the shoulder of the occupant P and the seatbelt 14 is small, and the occupant can be securely restrained on the seatback 10 .

[0004] Generally speaking, if Figure 1 As shown in (A), when the seat back 12 is in a nearly vertical state and a frontal collision occurs, Figure 1 As shown in (B), the occupant P will fall forward due to the influence of inertia. At this time, the pre-tightening function of the seat belt retractor 12 can prevent the occupant P from falling forward excessively.

[0005] Automobile seats have a tilt mechanism that allows the seat back to tilt backward or stand up forward. Figure 2 As shown in (A), if a frontal collision occurs with the seat back 10 tilted backward (lying down) to a great extent, Figure 2 As shown in (B), the spine from the head to the waist of the occupant P will be compressed, which may cause serious damage. This problem is more prominent in the retractor-integrated seat. In addition, in the type of seat with the retractor fixed to the B-pillar, when the seat back is tilted, a gap will be formed between the upper part of the seat belt and the shoulder of the occupant. Although it cannot be compared with the retractor-integrated seat, the compression of the spine is still a concern.

[0006] Also, if a frontal collision occurs while wearing a seat belt, such as a head-on collision, Figure 3As shown in (B), the seat back 10 on the right side where the upper end 14a of the seat belt 14 is located is more likely to tilt forward than on the opposite side, that is, the left side. This is because on the right side of the seat back 10, the shoulder of the occupant P is pressed against the seat back 10 by the seat belt 14, so that the seat back 10 and the right shoulder of the occupant P are in close contact with each other. As described above, if the seat back 10 is twisted or deformed (distorted), it will be difficult to restrain the occupant P appropriately.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2002-283892 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a vehicle seat safety device that can prevent a seat back from twisting (torsion) in the width direction when a vehicle crashes, thereby appropriately restraining an occupant.

[0012] Another object of the present invention is to provide a safety device for a vehicle seat, which can reduce the compression pressure on the spine of an occupant when the vehicle collides.

[0013] Solutions to the problem

[0014] The present invention relates to a vehicle seat safety device for protecting an occupant sitting on a vehicle seat, the device comprising a tilt mechanism capable of adjusting the angle of a seat back. The seat belt is structured to extend from an upper end portion of a first side in a width direction of the seat back toward a lower end of a second side opposite to the first side in a diagonal direction. In addition, an adjustment device is provided on a rotation shaft portion that serves as an axis when the seat back is tilted, and the adjustment device can change the rotation amount of the first side and the second side of the seat back when a vehicle collision occurs.

[0015] Here, the "first side in the width direction of the seat back" and the "second side" refer to the left and right sides of the occupant when the occupant is seated in a normal state facing the front. In addition, when the seat faces the travel direction, that is, the front, it can be said that it is the left and right sides of the seat back facing the travel direction.

[0016] In addition, "the seat belt extends diagonally from an upper end portion on a first side in the width direction of the seat back toward a lower end on a second side opposite to the first side", which is at least equivalent to a general three-point seat belt.

[0017] In addition, the "rotation shaft portion that becomes the axis when the seat back is tilted" refers to a portion connected to the tilt mechanism at the lower end of the seat back, which means a portion that becomes the rotation axis of the seat back. For example, it may be a circular hole formed in the seat back frame, a portion connected to the hole, or a rod-shaped shaft that passes through the hole and is connected to the left and right seat back frames.

[0018] In the present invention, the "adjustment device which can change the rotation amount of the first side and the second side of the seat back when the vehicle collides" can take into account the following situations, namely, setting the torsion bar described later on the rotation axis, or making the seat frame (seat back frame, seat side frame, etc.) have different rigidities in the width direction of the seat back, or setting a stopper or other components that limit the rotation of the seat back on one side in the width direction of the seat back.

[0019] In the present invention, by making the rotation amount of the first side and the second side of the seat back variable when a vehicle collision occurs, when the seat back is subjected to a force in the direction of tilting forward due to inertia, the twisting, that is, the distortion in the width direction of the seat back can be suppressed. As a result, the occupant can be restrained in a balanced manner, thereby significantly improving the occupant restraint performance. In particular, the rotation component of the occupant's head in the Z direction (relative to the vertical axis) is reduced, which helps to reduce head injuries. In addition, the rebound action of the occupant after the collision is suppressed, and as a result, the risk of a secondary collision inside the vehicle can be reduced.

[0020] The adjustment device may include a second torsion bar coupled to the rotation shaft portion at least on the second side of the seat back.

[0021] Here, "connected" to the rotating shaft portion means a state of being continuously connected to the rotating shaft portion coaxially and rotatable as a whole. In addition, the "rotating shaft portion" may be designated as an end portion of a torsion bar provided through a hole formed in the seat back frame.

[0022] By connecting the second torsion bar to the second side of the seat back, when the vehicle collides, the second side of the seat back is more likely to fall forward (to rotate) than the first side, thereby suppressing twisting of the seat back in the width direction.

[0023] The adjustment device may further include a first torsion bar connected to the rotation shaft portion on the first side of the seat back, and preferably, a torque characteristic T1 (N·m) of the first torsion bar relative to a displacement angle is set to be greater than a torque characteristic T2 (N·m) of the second torsion bar relative to a displacement angle.

[0024] Here, "torque characteristics relative to displacement angle" refers to the difficulty of twisting the torsion bar (ease of twisting). When the torque characteristics are high, the torsion bar is difficult to twist, and when the torque characteristics are low, the torsion bar is easy to twist. "Displacement angle" can also be called "torsion angle". The torque characteristics of the torsion bar can be adjusted by changing the thickness and length of the bar, or by changing the material of the bar.

[0025] In addition, the "torque characteristics with respect to displacement angle" is substantially synonymous with the "torsional rigidity" in the case of a round bar torsion bar. When the torsional rigidity is large, it is difficult to twist, and when the torsional rigidity is small, it is easy to twist.

[0026] When the vehicle collides with the seat back tilted backward, Figure 2 (B) shows that a large compressive pressure is applied to the spine of the occupant. However, according to the present invention, since the torsion bar is connected to the left and right sides of the rotating shaft of the seat back, even when the seat back is lying flat, the torsion bar twists, i.e., absorbs energy, and the seat back moves in the direction of standing up forward. As a result, the compressive pressure applied to the spine of the occupant is greatly reduced.

[0027] If the torsional stiffness of the torsion bars on the left and right sides is set to be the same, then Figure 3 As shown in (B), the seat back is tilted forwardly at the first side near the seat belt contacting the occupant's shoulder. In this case, the seat back is twisted or deformed (distorted), and the occupant's body is rotated in a direction protruding forward to the right side (right shoulder, etc.), making it difficult to properly restrain the occupant. For example, the rotation component of the occupant's head in the Z direction (relative to the vertical axis) increases, and there is a concern that head injuries may occur.

[0028] In the present invention, the torque characteristic T1 (N·m) of the first torsion bar relative to the displacement angle is set to be greater than the torque characteristic T2 (N·m) of the second torsion bar relative to the displacement angle. Therefore, the first torsion bar is difficult to twist, and the twisting of the seat back in the vehicle width direction is suppressed as described above when the vehicle collides. As a result, the occupant restraint performance is improved. In particular, the rotation component of the occupant's head in the Z direction (relative to the vertical axis) is reduced, which also helps to reduce head injuries. In addition, the rebound action of the occupant after the collision is suppressed, and as a result, the risk of secondary collision inside the vehicle can be reduced.

[0029] The vehicle seat may further include a seat belt retractor that rewinds the seat belt.

[0030] Here, "including the seat belt retractor" means that the retractor is arranged and fixed somewhere on the seat, excluding the case where it is fixed to a structural member such as a vehicle pillar. The upper and lower parts of the seat back, etc., do not affect the extension and retraction of the seat belt.

[0031] The seat belt retractor may be disposed near an upper end of the first side of the seat back.

[0032] When the seat belt retractor is disposed at the upper end of the seat back, the first side of the seat back becomes easier to move forward under the supplementary effect of the weight of the retractor. Therefore, it is more meaningful to use a torsion bar with a properly adjusted torque characteristic as shown in the present invention. In addition, the seat belt retractor can be installed near the lower back of the seat back in addition to the upper end of the seat back. In this case, it is necessary to provide a member for guiding the seat belt at the upper end of the seat back.

[0033] The seat belt retractor includes a load limiter for limiting the tension of the seat belt. Assume that the load of the load limiter is F L , the distance from the center of the rotating shaft to the upper end of the seat back when the seat is viewed from the side in the width direction is L, and the difference between the torques T1 and T2 is ΔT barI-II , it can be constructed to satisfy the following formula.

[0034] ΔT barI-II ≒F L ×L····(1)

[0035] The distance L may be a distance from the center of the rotating shaft portion to a belt pulling-out portion of the retractor.

[0036] Here, “≒” means approximately equal.

[0037] Load limiter operating load F L For example, it can be set to 2 kN to 5 kN.

[0038] When the vehicle is involved in a frontal collision, the occupant is restrained by the seat belt, and the load limiter starts to operate at the point in time when tension above a certain level is applied to the seat belt. In the above-mentioned manner, since the seat belt retractor is provided on the first side of the seat back, the load F when the load limiter operates is L , multiplied by the distance L from the rotation axis portion on the first side of the seat back to the seat belt pull-out portion (F L ×L) will be added to the rotating shaft portion on the first side of the seat back. L ×L) is approximately equal to the difference (ΔT T ) between the torque T1 of the first torsion bar and the torque T2 of the second torsion bar. barI-II ) are the same, the torque difference between the first side and the second side of the seat back can be offset. This can effectively suppress the torsion of the seat back in the width direction.

[0039] The reclining mechanism has a worm gear mechanism including a worm wheel connected to an end portion of the first or second torsion bar on the opposite side from the seat back, and a worm meshing with the worm wheel.

[0040] When a worm gear mechanism consisting of a worm wheel and a worm is used, the rotation of a worm shaft with a worm formed on the outer circumference rotates the worm wheel via the worm, thereby tilting the seat back. When the vehicle collides, the worm shaft does not rotate, so the seat back cannot be tilted, and the torque that causes the seat back to tilt forward is absorbed by the torsion bar.

[0041] The reclining mechanism may be configured to include a gear member connected to an end portion of the first or second torsion bar on the opposite side of the seat back, a locking member that restricts rotation of the gear member, and an adjusting member that releases meshing between the gear member and the locking member and adjusts an angle of a seat back frame.

[0042] By using a lever to release the meshing between the gear member and the lock member, the seat back can move freely and tilt. When the vehicle collides, the gear member and the lock member are meshed, so the seat back cannot tilt, and the torque that causes the seat back to tilt forward is absorbed by the torsion bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 1 and 2 are side views for explaining the background of the present invention, wherein (A) shows a state before a vehicle collision and (B) shows a state immediately after the vehicle collision.

[0044] Figure 2 1 and 2 are side views for explaining the background of the present invention, wherein (A) shows a state before a vehicle collision and (B) shows a state immediately after the vehicle collision.

[0045] Figure 3 The following are side views (perspective views) for explaining the background of the present invention, wherein (A) shows a state before a vehicle collision and (B) shows a state immediately after the vehicle collision.

[0046] Figure 4 It is a perspective view showing a frame structure and a safety device of a vehicle seat according to a first embodiment of the present invention.

[0047] Figure 5 It is a perspective view showing a power unit applicable to the tilt mechanism of the present invention.

[0048] Figure 6 1 is a perspective view showing the structure of a safety device according to a first embodiment of the present invention, and Figure 4 A portion of is shown enlarged.

[0049] Figure 7 1 and 2 are plan views showing the structure of a safety device according to a first embodiment of the present invention, wherein (A) corresponds to the right side of a seat and (B) corresponds to the left side of the seat.

[0050] Figure 8 is an exploded perspective view showing the structure of the safety device according to the first embodiment of the present invention, corresponding to Figure 6 part of.

[0051] Fig. 9 (A) and (B) are a schematic diagram (A) and a graph (B) for explaining the structure and characteristics of the safety device according to the first embodiment of the present invention.

[0052] Fig.10 This is a graph showing another aspect of the characteristics of the safety device according to the first embodiment.

[0053] Fig.11 (A) and (B) are perspective views showing the reclining action of the vehicle seat according to the first embodiment of the present invention.

[0054] Fig.12 It is a perspective view showing the operation of the safety device according to the first embodiment of the present invention.

[0055] Fig.13 1 and 2 are perspective views for explaining the operation of the safety device according to the first embodiment of the present invention, wherein (A) shows a state before a vehicle collision and (B) shows a state immediately after the vehicle collision.

[0056] Fig.14 1 is a perspective view showing the structure of a safety device according to a second embodiment of the present invention, and is a view in which the safety device is applied to a seat having a manual seat back reclining mechanism.

[0057] Fig.15 yes Fig.14 An exploded perspective view of the structure.

[0058] Fig.16 yes Fig.14 and Fig.15 A perspective view of the structure shown in the assembled (completed) state.

[0059] Fig.17 is an exploded perspective view showing the structure of a safety device according to a second embodiment of the present invention, showing Fig.15 The structure on the opposite side (right side) of (left side).

[0060] Fig.18 It is a perspective view showing an unlocking operation of a reclining mechanism of a vehicle seat according to a second embodiment of the present invention.

[0061] Fig.19 1 and 2 are side views showing an unlocking operation of a reclining mechanism of a vehicle seat according to a second embodiment of the present invention, wherein (A) shows a locked state and (B) shows an unlocked state. DETAILED DESCRIPTION

[0062] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. Figures 1 to 3 Briefly describe the creative background of the present invention.

[0063] Figure 1 (A) shows a state in which a seat belt retractor 12 for rewinding a seat belt 14 is provided on a seat back 10, and an occupant P sits down without tilting the seat back 10 too much. Figure 1 As shown in (B), the occupant P moves in the direction of falling forward due to inertia.

[0064] Figure 2 (A) shows a state where the seat back 10 is tilted back greatly. Figure 1 The situation in (B) is different. Figure 2 As shown in (B), the occupant P does not move much in the direction of falling forward. This is because the occupant P is restrained by the upper end 14a of the safety belt 14 in the direction of being close to the seat back 10. As a result, compression pressure is applied to the spine of the occupant P, which may cause serious damage.

[0065] Therefore, the present invention proposes a structure in which a torsion bar is connected to a reclining mechanism of a seat, that is, the torsion bar is connected to the rotating shaft portions on both the left and right sides of the seat back.

[0066] Figure 3 (A) shows a state where the occupant P sits normally on the seat cushion 11. In this state, when a frontal collision occurs, Figure 3 As shown in FIG. 1 , the seat back 10 ( 10R) tends to tilt greatly forward on the side (right side) near the shoulder of the occupant P where the upper end 14a of the safety belt 14 contacts. In this way, the seat back 10 is twisted or deformed (distorted), making it difficult to properly restrain the occupant P. The present invention also solves these problems.

[0067] like Figure 3As shown in FIG. 1 , the present invention is a vehicle seat safety device installed on a vehicle seat, and the vehicle seat includes a seat cushion 11 on which an occupant P sits, a seat back 10 located on the back of the occupant P, a tilt mechanism capable of adjusting the angle of the seat back 10, and a seat belt retractor 12 for rewinding a seat belt 14. The seat belt 14 extends diagonally from a shoulder portion on a first side (right side) in the width direction of the seat back 10 toward a lower end on a second side (left side) opposite to the first side. In addition, the seat belt retractor 12 may be provided not only on the upper portion of the seat back 10 but also on the rear lower portion of the seat back 10.

[0068] (First embodiment)

[0069] The following will refer to Figures 4 to 13 A first embodiment of the present invention will be described. The first embodiment is applied to a vehicle seat that performs an operation of reclining a seat back using power from a motor.

[0070] Figure 4 It is a perspective view showing a frame structure and a safety device of a vehicle seat according to a first embodiment of the present invention. Figure 5 It is a perspective view showing a power unit applicable to the tilt mechanism of the present invention. Figure 6 1 is a perspective view showing the structure of a safety device according to a first embodiment of the present invention, and Figure 4 A portion of is shown enlarged. Figure 7 1 and 2 are plan views showing the structure of a safety device according to a first embodiment of the present invention, wherein (A) corresponds to the right side of a seat and (B) corresponds to the left side of the seat. Figure 8 is an exploded perspective view showing the structure of the safety device according to the first embodiment of the present invention, corresponding to Figure 6 In addition, in the symbols of each figure, basically, the component marked with "R" is provided on the right side of the seat back, and the component marked with "L" is provided on the left side.

[0071] like Figures 4 to 8 As shown, the reclining mechanism includes a motor 110 and a central shaft 112 that transmits power from the motor 110. The power of the motor 110 is transmitted from the central shaft 112 to bevel gears 114L, 114R and worm shafts 115L, 115R. The rotation of the worm shafts 115L, 115R is transmitted to the rotating shaft portions 106L, 106R of the seat back frames 104L, 104R via worms 116L, 116R and worm wheels 118L, 118R formed thereon.

[0072] The rotating shaft portions 106L, 106R are portions connected to the reclining mechanism at the lower end portions of the seat back frames 104L, 104R, and may be designated as circular holes formed in the seat back frames. Alternatively, they may be rod-shaped shafts that pass through the holes and are connected to the left and right seat back frames. Furthermore, in the present embodiment, they may also be designated as ends of the torsion bars 120L, 120R that are provided through holes formed in the seat back frames.

[0073] The safety device according to the present embodiment includes a first torsion bar 120R connected to a first side (right side) of the seat back 10 and a second torsion bar 120L connected to a second side (left side) of the seat back 10. One ends (inner ends) of the first torsion bar 120R and the second torsion bar 120L are fixed to the seat back frames 104R and 104L on both sides. The other ends (outer ends) of the first torsion bar 120R and the second torsion bar 120L are connected to worm wheels 118R and 118L.

[0074] like Figures 6 to 8 As shown, limit switches 122a and 122b are provided on the seat back frame 104L and the seat side frame 102R to limit the forward tilt angle of the seat back 10 (seat back frames 104L and 104R). When it is sensed that the rotation angle of the seat back frames 104L and 104R has reached its limit, measures such as stopping the action of the motor 110 are taken.

[0075] In addition, the reference numerals 126R and 126L in the figure are connecting plates for fixing the first torsion bar 120R and the second torsion bar 120L to the seat back frames 104R and 104L. In addition, the reference numerals 124R and 124L are stoppers for preventing the first torsion bar 120R and the second torsion bar 120L from falling off from the seat side frames 102R and 102L. In addition, the reference numeral 128L is a spacer disposed between the seat back frame 104L and the seat side frame 102L.

[0076] In the present invention, the torque characteristic T1 (N·m) of the first torsion bar 120R with respect to the displacement angle is set to be greater than the torque characteristic T2 (N·m) of the second torsion bar 120L with respect to the displacement angle.

[0077] Fig. 9 (A) and (B) are a schematic diagram (A) and a curve diagram (B) for explaining the structure and characteristics of the safety device involved in the first embodiment of the present invention. Fig. 9 (B) is a diagram showing the torque of the torsion bar relative to the rotation angle (displacement angle).

[0078] In this embodiment, the seat belt retractor 12 includes a load limiter (not shown) for controlling the tension of the seat belt 14. Assume that the load at which the load limiter operates is F. L, the distance from the center of the rotating shaft portion 106L, 106R to the upper end portion of the seat back 10 when the seat is viewed from the side in the width direction is L, and the difference between the torques T1 and T2 is ΔT barI-II When , it is constructed to satisfy the following formula.

[0079] ΔT barI-II ≒F L ×L····(1)

[0080] Also, the load limiter operates on a load F L Can be set from 2kN to 5kN.

[0081] Fig.10 1 and 2 are graphs showing another aspect of the characteristics of the safety device according to the present invention. In the present invention, the torque characteristic T1 (N·m) of the first torsion bar 120R and the torque characteristic T2 (N·m) of the second torsion bar 120L relative to the displacement angle are set to be progressive relative to the displacement angle.

[0082] (Operation of the tilt mechanism)

[0083] Fig.11 (A) and (B) are perspective views showing the tilting action of the vehicle seat according to the first embodiment of the present invention. When the seat back 10 is tilted backward, the power of the motor 110 is transmitted to the rotating shafts 106L and 106R of the seat back frames 104L and 104R via the center shaft 112, bevel gears 114L and 114R, worm shafts 115L and 115R, and worm gear mechanisms (116L, 118L, 116R, 118R), as shown in FIG. Fig.11 As shown in (A), the seat back frames 104L, 104R are rotated, that is, swung, rearward.

[0084] On the other hand, when the seat back 10 is erected forward, the power of the motor 110 is transmitted to the rotating shaft portions 106L and 106R of the seat back frames 104L and 104R via the center shaft 112, the bevel gears 114L and 114R, the worm shafts 115L and 115R, and the worm gear mechanisms (116L, 118L, 116R, 118R), as shown in FIG. Fig.11 As shown in (B), the seat back frames 104L, 104R are rotated forward, that is, swung.

[0085] (Safety device operation)

[0086] Fig.12 It is a perspective view showing the operation of the safety device according to the first embodiment of the present invention. Fig.131 and 2 are perspective views for explaining the operation of the safety device according to the first embodiment of the present invention, wherein (A) shows a state before a vehicle collision and (B) shows a state immediately after the vehicle collision.

[0087] like Fig.13 As shown in FIG. 12A , when a front collision occurs in the vehicle, the load limiter starts to operate at the point when a tension above a certain level is applied to the seat belt. At the same time, a force is applied in the direction in which the seat back tilts forward due to inertia. At this time, the reclining mechanism is not activated due to the meshing between the worm gears 116L, 116R and the worm wheels 118L, 118R, but as shown in FIG. 12A , the torsion bars 120L and 120R twist and absorb energy, causing the seat back 10 (seat back frames 104L and 104R) to rotate forward.

[0088] In this embodiment, the torque characteristic T1 (N·m) of the first torsion bar 120R with respect to the displacement angle is set to be greater than the torque characteristic T2 (N·m) of the second torsion bar 120L with respect to the displacement angle. L , the distance from the center of the rotating shaft portion 106L, 106R to the upper end portion of the seat back 10 is L, and the difference between the torques T1 and T2 is ΔT barI-II , it is set to satisfy the following formula.

[0089] ΔT barI-II ≒F L ×L····(1)

[0090] In this embodiment, since the seat belt retractor 12 is disposed on the first side (right side) of the seat back 10, the load F when the load limiter is in operation is L , multiplied by the distance L from the rotation shaft portion 106R on the first side of the seat back 10 to the seat belt withdrawal portion (F L ×L) is added to the rotation shaft portion 106R on the first side of the seat back 10. Therefore, by making this moment (F L ×L) is approximately equal to the difference (ΔT T ) between the torque T1 of the first torsion bar 120R and the torque T2 of the second torsion bar 120L. barI-II ) is the same, the torque difference between the first side and the second side of the seat back 10 can be offset. As a result, the torsion of the seat back 10 in the width direction can be effectively suppressed, and the member restraint performance can be improved.

[0091] (Second embodiment)

[0092] The following will refer to Figures 14 to 19The second embodiment of the present invention is applied to a vehicle seat in which the seat back 10 is manually tilted without using power from a motor. Components corresponding to those of the first embodiment are marked with the same last two digits as much as possible.

[0093] Fig.14 It is a perspective view showing the structure of a safety device according to a second embodiment of the present invention. Fig.15 yes Fig.14 An exploded perspective view of the structure. Fig.16 yes Fig.14 and Fig.15 A perspective view of the structure shown in the assembled (completed) state. Fig.17 is a disassembled perspective view showing the structure of a safety device according to a second embodiment of the present invention, showing Fig.15 The structure on the opposite side (right side) of (left side).

[0094] The reclining mechanism involved in this embodiment includes gear components 226L and 226R connected to the rotating shaft portions 206L and 206R of the left and right seat back frames 204L and 204R via torsion bars 220L and 220R, lock plates 228L and 228R connected to the left and right end portions of the lock plate shaft 230, and a rod 224 for releasing the engagement between the gear components 226L, 226R and the lock plates 228L, 228R.

[0095] The rod 224 is coupled to a rod guide shaft 232 and moves along the rod guide grooves 234L and 234R. The locking plate shaft 230 is coupled to the locking plates 228L and 228R, and these locking plates 228L and 228R move synchronously on the left and right sides. And, when the rod 224 is lifted upward, the meshing between the locking plates 228L and 228R and the gear members 226L and 226R is released. As a result, the seat back 10 is in a free state, and the tilt angle can be adjusted.

[0096] Similar to the first embodiment, the safety device according to the present embodiment includes a first torsion bar 220R connected to the seat back frame 204R and a second torsion bar 220L connected to the seat back frame 204L. One ends (inner ends) of the first torsion bar 220R and the second torsion bar 220L are fixed to the seat back frames 204R and 204L on both sides via rotation shafts 206L and 206R. The other ends (outer ends) of the first torsion bar 220R and the second torsion bar 220L are connected to gear members 226R and 226L.

[0097] like Fig.17 As shown, a rod plate 260 is provided on the right side opposite to the rod 224 and moves synchronously with the rod 224. Fig.15 ) and the left side ( Fig.17 ) is that the rod 224 and the rod plate 260 are interchanged.

[0098] Covers 238L and 238R are provided to cover the rod 224 and the rod plate 260, and stoppers 270L and 270R are provided to fix the ends of the torsion bars 220L and 220R, and stoppers 272L and 270R are provided to fix the ends of the locking plate shaft. One end of the spring 236L and 236R is connected to the rod 224 and the rod plate 260, and the other end of the spring 236L and 236R is connected to the cover 238L and 238R.

[0099] And, the reference numerals 244R and 224L in the figure are connecting plates for fixing the first torsion bar 220R and the second torsion bar 220L to the seat back frames 204R and 204L. In addition, the reference numeral 252L is a rod protection pin connected between the rod guide shaft 206 and the rod 224. The reference numeral 252R is a rod protection pin connected between the rod guide shaft 206 and the rod plate 260. The reference numerals 254L and 254R are lock plate shaft extensions, one end of which is connected to the end of the lock plate shaft 230, and the other end reaches the covers 238L and 238R via the lock plates 228L and 228R, and is fixed by the stoppers 272L and 270R.

[0100] The seat side frames 202L and 202R are formed with rod guide grooves 234L and 234R for limiting the movement of the rod guide shaft 230. In addition, guide grooves 242L and 242R for limiting the rotation angle of the seat back frames 204L and 204R are formed.

[0101] The rod 224 is formed with a locking plate pin guide groove 249, into which the locking plate pin 248L is inserted, thereby guiding the movement of the locking plates 228L and 228R. Similarly, the rod plate 260 is also formed with a locking plate pin guide groove 262, into which the locking plate pin 248R is inserted, thereby guiding the movement of the locking plates 228L and 228R.

[0102] Fig.18 It is a perspective view showing a reclining operation of a vehicle seat according to a second embodiment of the present invention. Fig.19 1 and 2 are side views showing a reclining operation of a vehicle seat according to a second embodiment of the present invention, wherein (A) shows a locked state and (B) shows an unlocked state.

[0103] like Fig.19 As shown in (A), in the seat according to this embodiment, when the rod 224 is in a specified position (for example, in a horizontal state), the gear member 226L coupled to the torsion bar 220L is engaged with the lock plate 228L, so that the seat cannot be tilted.

[0104] On the other hand, Fig.18 and Fig.19 As shown in (B), when the lever 224 is pulled up, the lock plate pin 248L moves along the lock plate pin guide 262, and the lock plate 228L rotates in the counterclockwise direction. As a result, the meshing between the gear member 226L and the lock plate 228L is released, and the seat back 10 can be tilted. In addition, the mechanism on the right side of the seat also operates synchronously with the mechanism on the left side.

[0105] The characteristics, functions, and effects of the torsion bars 220L and 220R used in this embodiment are the same as those in the above-described first embodiment, and therefore repeated description will be omitted.

[0106] The present invention has been described above in conjunction with the above exemplary embodiments, and it is obvious that various equivalent changes or modifications can be thought of according to the present disclosure by those skilled in the art. Therefore, the above exemplary embodiments of the present invention should be considered as exemplary rather than restrictive. Various changes can be made to the described embodiments without departing from the spirit and scope of the present invention.

Claims

1. A safety device for a vehicle seat, used to protect an occupant sitting on a vehicle seat, which has a tilt mechanism capable of adjusting the angle of a seat back, characterized in that: The seat belt is structured to extend diagonally from an upper end portion on a first side in the width direction of the seat back toward a lower end on a second side opposite to the first side, and An adjustment device is provided on a rotation shaft portion that serves as an axis when the seat back is tilted, and the adjustment device is configured to change the amount of rotation of the first side and the second side of the seat back when a vehicle collision occurs.

2. The vehicle seat safety device according to claim 1, wherein: The adjustment device includes a second torsion bar coupled to the rotation shaft portion at least on the second side of the seat back.

3. The vehicle seat safety device according to claim 2, wherein: The adjustment device further includes a first torsion bar connected to the rotation shaft portion on the first side of the seat back, and The torque characteristic T1 (N·m) of the first torsion bar with respect to the displacement angle is set to be greater than the torque characteristic T2 (N·m) of the second torsion bar with respect to the displacement angle.

4. The vehicle seat safety device according to claim 3, characterized in that: The vehicle seat also includes a seat belt retractor that rewinds the seat belt.

5. The vehicle seat safety device according to claim 4, characterized in that: The seat belt retractor is disposed near an upper end of the first side of the seat back.

6. The vehicle seat safety device according to claim 5, characterized in that: The seat belt retractor includes a load limiter for limiting the tension of the seat belt, Assume the load limiter operates on a load of F L , the distance from the center of the rotation shaft to the upper end of the seat back when the seat is viewed from the side in the width direction is L, and the difference between the torques T1 and T2 is ΔT barI-II When , it can be constructed to satisfy the following formula, ΔT barI-II ≒F L ×L。 7. The vehicle seat safety device according to claim 6, wherein: The distance L is a distance from the center of the rotating shaft portion to a belt pulling-out portion of the retractor.

8. The vehicle seat safety device according to any one of claims 3 to 7, characterized in that: The reclining mechanism includes a worm gear mechanism including a worm wheel connected to an end portion of the first or second torsion bar on a side opposite to the seat back, and a worm screw meshing with the worm wheel.

9. The vehicle seat safety device according to any one of claims 3 to 7, characterized in that: The reclining mechanism includes a gear member connected to an end portion of the first or second torsion bar on the opposite side to the seat back, a locking member that restricts rotation of the gear member, and an adjusting member that releases meshing between the gear member and the locking member and adjusts an angle of a seat back frame.

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