JP2006298247A - Seat belt retractor and seat belt device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure stable energy absorption (EA) operation without complexity or enlargement of device structure and without influence of operation of a pretensioner. <P>SOLUTION: A seat belt retractor comprises: a torsion bar 7 whose one side in an axial direction is connected with a spool 4 and which is torsionally deformed by relative displacement between the one side and the other side; the pretensioner 11 positioned on the other side in an axial direction of a spool 4 to rotate the spool 4 in a direction retracting a seat belt 3 when a vehicle is abruptly decelerated; and a shear pin 50 axially passing through and engaging a left rocking base 14L, the spool 4, and a rocking base 14R to connect a pawl 13L with a pawl 13R. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a seat belt retractor that winds up a seat belt, and more particularly, to a seat belt retractor having an EA mechanism that absorbs inertia energy applied to an occupant when the seat belt is locked to restrain the movement of the occupant during an abnormality. The present invention relates to a seat belt device provided with

  BACKGROUND ART A seat belt device provided in a vehicle seat is an indispensable device as a device for restraining the rapid movement of an occupant due to acceleration generated at the time of a vehicle collision and for ensuring the safety of the occupant's body.

  This seat belt device generally includes a seat belt (webbing), a seat belt retractor, a buckle device, and the like.

  The retractor winds a seat belt around a winding member (spool) and pulls it in by a spring force, and normally accommodates the seat belt in the retracted state. When the occupant wears the seat belt, the seat belt accommodated is pulled out by pulling the tongue plate provided at one end opposite to the seat belt winding side, and this is engaged with the buckle device provided beside the seat. By combining them, the seat belt is attached.

  The retractor configured as described above locks the pull-out of the seat belt from the take-up member at the time of a collision in which an impact is applied, and restrains the body of the occupant moving rapidly forward by the locked seat belt. Here, a pretensioner and a lock mechanism are usually provided in order to restrain the occupant's body more strongly, particularly during sudden deceleration of the vehicle.

  The pretensioner removes the slack of the seat belt when the acceleration sensor detects that the vehicle has suddenly decelerated, and improves the restraint force by the seat belt. For example, gas is generated from the gas generating means in response to the detection signal of the acceleration sensor, and the bag-like body expands to remove the slack of the seat belt by shortening the overall length in the longitudinal direction, or the gas There is a system in which the piston slides in the cylinder by the gas from the generating means, and the spool is rotated in the winding direction via the pinion to remove the slack of the seat belt.

  The locking mechanism includes a locking member (locking base) that rotates together with the spool. Then, in accordance with the detection signal of the acceleration sensor, a locking member (pawl) provided on the locking base is locked to an internal tooth (ratchet tooth) provided on a fixed member (such as a retractor frame) of the vehicle. The rotation of the locking base and the spool in the pull-out direction is restricted.

  On the other hand, when the forward movement of the occupant is abruptly restricted as described above at the time of sudden deceleration of the vehicle or the like, an impact force due to the restrained reaction acts on the chest of the occupant via the seat belt. In order to alleviate the impact force applied to the occupant, the seat belt is held at a predetermined tension load while applying a certain amount of pulling resistance to the seat belt immediately after locking, and the seat belt is fed out for a predetermined length in that state. Thus, a mechanism for absorbing collision energy acting on the occupant (Energy Absorption; hereinafter referred to as “EA” mechanism as appropriate) is already known.

  In this method, a plastically deformable shaft (torsion bar) is arranged inside the spool around which the seat belt is wound, and at this time, one side of the torsion bar is connected to the spool side and the other side is connected to the locking base side. is doing. When the locking base is locked by the locking mechanism during rotation of the vehicle suddenly, such as in an emergency, the tension of the seat belt that restrains the occupant trying to move forward due to inertial force is reduced on one side of the torsion bar. The relative rotational force in the seat belt pull-out direction with respect to the other side is obtained, and when this relative rotational force exceeds a certain value, the torsion bar undergoes plastic deformation, and the collision energy is absorbed by the plastic deformation resistance at this time. As a result, the spool is gradually rotated in the direction in which the seat belt is pulled out even though the lock mechanism is in effect, and the seat belt is extended while applying a certain tension to the seat belt. The force acting between them is relaxed.

  Here, in the seat belt retractor including the pretensioner, the lock mechanism, and the EA mechanism as described above, when the spool is allowed to rotate slightly in the seat belt pulling direction as described above when the EA mechanism is operated, As described above, the pretensioner is already rotationally connected to the spool and operates in the seat belt retracting direction (that is, the reverse direction). Therefore, if one side portion of the spool that is connected to the torsion bar is connected to the pretensioner, and the lock base that is locked by the lock mechanism is connected to the other side of the torsion bar, the pre-loading is performed as described above. Even if the lock mechanism locks the winding direction rotation on the other side of the torsion bar after the tensioner operates in the winding direction of the spool, the one side of the torsion bar is twisted relative to the other side and rotates relative to the other side. The operation of the pretensioner acts in the direction opposite to the relative rotation direction and inhibits it. That is, the operation of the EA mechanism is affected by the operation of the pretensioner, and it is difficult to ensure a stable operation.

  Therefore, in order to cope with this, as described in Patent Document 1, for example, a lock mechanism (however, as will be described later) is provided on the other side of the torsion bar opposite to the one side portion connected to the spool. And a pre-tensioner are proposed. In this structure, as a lock mechanism, a normal-time lock mechanism that locks both sides of the spool at normal times, and a lock for sudden vehicle deceleration that locks rotation in the winding direction on the other side of the spool when the vehicle suddenly decelerates. Mechanism. Thus, when one side of the torsion bar is twisted relative to the other side in the EA mechanism, only the locking mechanism for sudden deceleration of the vehicle is operated, and the operation of the EA mechanism is affected by the operation of the pretensioner. Stable operation can be ensured.

Japanese Patent No. 2610392

  However, the prior art has the following problems.

  That is, during normal operation, the normal locking mechanism that locks both the one side and the other side in the axial direction of the spool is operated, and at the time of sudden deceleration of the vehicle, the above-mentioned normal time use is ensured. This lock mechanism is retracted and invalidated, and another lock mechanism for sudden deceleration of the vehicle that locks only the other side in the axial direction is operated. As described above, since separate locking mechanisms are provided for normal use and for sudden deceleration of the vehicle, the structure of the apparatus is complicated and the entire apparatus is enlarged.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a seat belt retractor capable of ensuring a stable EA operation that is not affected by the operation of a pretensioner without complicating or increasing the size of the device structure, and a seat belt device using the same. There is.

  In order to achieve the above-described object, the first invention of the present application is a spool for winding a seat belt, and is disposed on the radially inner side of the spool, and one side in the axial direction is connected to the spool, and the one in the axial direction is And a torsion bar capable of absorbing the kinetic energy of an occupant due to relative displacement between the side and the other side in the axial direction, and the other side in the axial direction of the spool, and in the vehicle sudden deceleration state, the spool is placed in the seat A pretensioner that generates a rotational driving force for rotating the belt in the winding direction and a rotation of the other side of the torsion bar in the axial direction and the spool in the pull-out direction of the seat belt in cooperation with each other. Locking to the stationary member of the vehicle so as to prevent it; And having a linkage locking mechanism to unlock to the stationary member of the spool while maintaining a lock on the stationary member of the axial other side of the torsion bar.

  In the first invention of the present application, in the normal state, the linkage locking mechanism first links the rotation of the torsion bar in the seat belt pull-out direction on the other side in the axial direction with the rotation of the spool in the pull-out direction of the seat belt. Stop each one.

  On the other hand, when the vehicle suddenly decelerates, the pretensioner operates in response to the sudden deceleration, and the spool rotates in the seat belt winding direction by the rotational driving force, thereby improving the restraining force of the occupant by the seat belt. Thereafter, the occupant's body pulls the seat belt with a greater force than the predetermined force due to inertia at the time of sudden deceleration of the vehicle, and the force in the direction of pulling out the seat belt acts on the spool. At the time of deceleration, the linkage between the one side in the axial direction and the other side is canceled, and the lock on the fixed side member on the other side in the axial direction of the torsion bar is maintained while the spool (in other words, one side in the axial direction of the torsion bar) Release the lock to the stationary member. As a result, one side of the torsion bar is rotationally displaced relative to the other side in the axial direction, and occupant kinetic energy can be absorbed by the torsional deformation of the torsion bar (EA mechanism). Further, since the pretensioner is located on the other side of the spool, the operation of the EA mechanism in which one side of the torsion bar is twisted relative to the other side as described above is affected by the operation of the pretensioner. Therefore, stable operation can be ensured.

  As described above, in the first invention of the present application, the locking is performed on both sides in the axial direction of the torsion bar in the normal state only by using the cooperative locking mechanism, and the torsion bar is deformed for torsional deformation of the torsion bar at the time of sudden deceleration of the vehicle. Only the other axial side can be kept locked and the other axial side can be released. Therefore, the device structure is simplified and the overall device size is reduced compared to the conventional structure that has separate locking mechanisms for normal use and for sudden vehicle deceleration, and disables the normal locking mechanism for sudden vehicle deceleration. Further, the number of parts can be reduced.

  According to a second invention, in the first invention, the first locking member is located on the other axial side of the spool and connected to the other axial side of the torsion bar, and the pretensioner is the vehicle A rotational driving force for rotating the spool in the seat belt retracting direction in the sudden deceleration state is applied to the first locking member, and the linkage locking mechanism is configured such that the first locking member is fixed to the vehicle fixed side member. A first locking member for locking to the head is provided.

  When the vehicle suddenly decelerates, the pretensioner applies a rotational driving force to the first locking member, whereby the spool can be rotated in the seat belt winding direction via the first locking member. Further, the cooperation locking mechanism includes the first locking member, whereby the first locking member can be locked to a fixed member of the vehicle such as a frame.

  According to a third aspect of the present invention, in the second aspect of the present invention, the first locking member is rotatably provided on the first locking member, and performs a locking operation of the first locking member in accordance with a deceleration of the vehicle. It is characterized by being.

  By providing the pawl as the first locking member, the pawl can be rotated in accordance with the signal from the sensor, for example, according to the deceleration of the vehicle, and the locking operation of the first locking member can be performed.

  In a fourth aspect based on the second aspect, the first locking member is rotatably provided on the first locking member, and is urged by a spring in the locking direction of the first locking member to perform a locking operation. It is a pawl to be performed.

  By providing the pawl biased by the spring as the first locking member, the pawl is rotated in the locking direction by the biasing force of the spring, and the locking operation of the first locking member can be performed.

  A fifth invention according to any one of the second to fourth inventions, further comprising: a second locking member positioned on one side in the axial direction of the spool, wherein the cooperative locking mechanism rotates to the second locking member. The second locking member is provided on the stationary side member of the vehicle, and the second locking member is provided.

  The second locking member provided in the cooperation locking mechanism can lock the second locking member to a fixed member of the vehicle such as a frame.

  A sixth aspect of the present invention is the pawl according to the fifth aspect, wherein the second locking member is rotatably provided on the second locking member and performs a locking operation of the second locking member in accordance with a deceleration of the vehicle. It is characterized by being.

  By providing the pawl as the second locking member, the pawl can be rotated according to the signal from the sensor, for example, according to the deceleration of the vehicle, and the second locking member can be locked.

  In a seventh aspect based on the fifth or sixth aspect, the linkage locking mechanism penetrates or engages at least the spool in the axial direction in order to connect the first locking member and the second locking member. It is provided with the pin member provided with at least 1 to-be-breakable part which is provided so that it may match and can be fractured | ruptured according to a load.

  As a result, the first locking member and the second locking member are connected to each other without rupturing the expected breakage portion of the pin member in a normal state, and the other side in the axial direction of the torsion bar and the seat belt of the spool Can be prevented from rotating in the pulling-out direction, and at the time of sudden deceleration of the vehicle, the portion to be broken can be broken to eliminate the linkage due to the connection, and one side of the torsion bar can be rotated relative to the other side.

  To achieve the above object, according to an eighth aspect of the present invention, there is provided a spool for winding up a seat belt, the spool being disposed radially inward of the spool and connected in one axial direction to the spool. And a torsion bar capable of absorbing the kinetic energy of the occupant by the relative displacement between the side and the other side in the axial direction, and connected to the other axial side of the torsion bar located on the other side in the axial direction of the spool A first locking base, and a first pawl that is rotatably provided on the first locking base and locks the first locking base to a stationary member of the vehicle according to a deceleration of the vehicle, A second locking base located on one side of the spool in the axial direction; and the second locking base is rotatably provided on the second locking base, and the second locking base is provided in accordance with the deceleration of the vehicle. A second pawl for locking the base to the stationary member of the vehicle, and the other side of the spool in the axial direction for rotating the spool in the seat belt winding direction in the vehicle sudden deceleration state In order to connect a pretensioner that generates a rotational driving force and transmits the rotational force to the first locking base, and the first pawl and the second pawl, the first locking base, the spool, and the second locking base are connected to each other. It is provided so as to penetrate or engage in the axial direction, and has two scheduled breakage portions that break at a predetermined timing according to the applied load, near the first locking base and near the second rocking base. The two fracture planned portions of the shear pin are provided in the normal state and the pre-deceleration state in the vehicle sudden deceleration state. During the operation of the tensioner, the first stage maintains a substantially unbroken state so as to maintain the locking state of the spool to the first and second locking bases; In the second stage, each of the two breaks based on the force of the vehicle occupant to rotate the seat belt in the pulling direction acting on the spool, and the spool is locked to the first and second locking bases. The breaking strength of the planned breaking portion is set so as to release the state.

  In the eighth invention of the present application, at the normal time, the two scheduled breakage portions of the shear pin are in a substantially unbroken state that is not substantially broken, and the spool is connected to the first locking base and the second locking base via the shear pin. At this time, if the first and second pawls lock the first and second locking bases to the stationary member of the vehicle according to the deceleration of the vehicle, rotation of the spool in the pull-out direction of the seat belt is prevented.

  On the other hand, when the vehicle suddenly decelerates, the pretensioner operates in response to the sudden deceleration, and the spool rotates in the seat belt winding direction by the rotational driving force, thereby improving the restraining force of the occupant by the seat belt. In the first stage immediately after the sudden deceleration of the vehicle, the two rupture-scheduled portions of the shear pin are in a substantially unbroken state that is not substantially broken and the spool is connected to the first and second locking bases, Since the first and second pawls lock the first and second locking bases to the stationary member of the vehicle according to the deceleration of the vehicle, the spool is prevented from rotating in the pull-out direction of the seat belt, as described above. The

  After that, the occupant's body pulls the seat belt with a greater force than the predetermined force due to inertia at the time of sudden deceleration of the vehicle, and the force in the direction of pulling out the seat belt acts greatly on the spool. In the second stage when the vehicle suddenly decelerates, it breaks to release the connection between the one side and the other side in the axial direction, and the lock of the spool to the first and second locking bases is released. As a result, one axial side of the torsion bar connected to the spool is rotationally displaced relative to the other axial side (fixed to the first locking base locked by the first pawl as described above), Passenger kinetic energy can be absorbed by the torsional deformation of the torsion bar (EA mechanism). At this time, since the pretensioner is located on the other side in the axial direction of the spool and is connected to the first locking base, the operation of the EA mechanism in which one side of the torsion bar is twisted relative to the other side and rotates relative to the other side as described above. Can ensure stable operation without being affected by the operation of the pretensioner.

  As described above, in the eighth invention of the present application, the shaft is normally used only by using the shear pin provided with the planned breaking portion, which is provided so as to penetrate or engage with the first locking base, the spool, and the second locking base. In the second stage during sudden deceleration of the vehicle, only the other side in the axial direction of the torsion bar is kept locked due to torsional deformation of the torsion bar in the second stage during vehicle sudden deceleration. One side in the axial direction can be released. Therefore, the device structure is simplified and the overall device size is reduced compared to the conventional structure that has separate locking mechanisms for normal use and for sudden vehicle deceleration, and disables the normal locking mechanism for sudden vehicle deceleration. Further, the number of parts can be reduced.

  In order to achieve the above object, the ninth invention of the present application is a spool for winding up a seat belt, and is disposed on the radially inner side of the spool and connected to one side in the axial direction with the spool. And a torsion bar capable of absorbing the kinetic energy of the occupant by the relative displacement between the side and the other side in the axial direction, and connected to the other axial side of the torsion bar located on the other side in the axial direction of the spool The first locking base and the first locking base that is rotatably provided on the first locking base and that is urged by a spring in the locking direction of the first locking base to lock the vehicle. A third pawl for locking to the side member, a second locking base located on one axial side of the spool, and the second locking base A second pawl for locking the second locking base to a stationary member of the vehicle according to a deceleration of the vehicle, and a vehicle positioned on the other axial side of the spool. A pretensioner that generates a rotational driving force for rotating the spool in the seat belt winding direction in a sudden deceleration state and transmits the rotational force to the first locking base, and the first pawl and the third pawl are connected. In order to accomplish this, the first locking base, the spool, and the second locking base are provided so as to penetrate or engage in the axial direction, and a planned fracture portion that breaks at a predetermined timing according to the applied load is provided. There are shear pins provided at two locations near the first locking base and the second locking base, and the shear pins are broken at the two locations. The scheduled portions maintain a substantially unbreakable state so as to maintain the locking state of the spool to the first or second locking base in normal times; the pretensioner operation in the vehicle sudden deceleration state Sometimes only the planned fracture portion near the first locking base breaks to release the locking state of the spool to the first locking base, and then the fracture planned portion near the second locking base also breaks. The rupture strengths of the planned rupture portions are respectively set so as to release the locked state of the spool to the second locking base.

  In the ninth invention of the present application, at the normal time, the two ruptured portions of the shear pin are in a substantially unbroken state that is not substantially broken, and the spool is connected to the first locking base and the second locking base via the shear pin. At this time, if the third and second pawls lock the first and second locking bases to the stationary member of the vehicle according to the deceleration of the vehicle, rotation of the spool in the pull-out direction of the seat belt is prevented.

  On the other hand, when the vehicle suddenly decelerates, the pretensioner operates in response to the sudden deceleration, and the spool rotates in the seat belt winding direction by the rotational driving force, thereby improving the restraining force of the occupant by the seat belt. When the pretensioner is activated, the portion to be broken in the vicinity of the first locking base among the two portions to be broken of the shear pin breaks, and the lock between the first locking base and the spool is released, but the first locking base itself is locked. It is locked to the stationary member of the vehicle by a third pawl biased by a spring in the direction. On the other hand, at this time, the planned fracture portion in the vicinity of the second locking base is in a substantially unbroken state where it is not substantially broken, and the spool is connected to the second locking base, and the second pawl is set according to the deceleration of the vehicle at this time. Since the second locking base is locked to the stationary member of the vehicle, the spool is prevented from rotating in the pull-out direction of the seat belt as described above.

  Thereafter, the occupant's body pulls the seat belt with a greater force than the predetermined force due to inertia at the time of sudden deceleration of the vehicle, and the force in the direction of pulling out the seat belt acts on the spool. The portion to be broken in the vicinity of is broken here to release the lock of the spool to the second locking base. As a result, one axial side of the torsion bar connected to the spool is rotationally displaced relative to the other axial side (fixed to the first locking base locked by the first pawl as described above), Passenger kinetic energy can be absorbed by the torsional deformation of the torsion bar (EA mechanism). At this time, since the pretensioner is located on the other side in the axial direction of the spool and is connected to the first locking base, the operation of the EA mechanism in which one side of the torsion bar is twisted relative to the other side and rotates relative to the other side as described above. Can ensure stable operation without being affected by the operation of the pretensioner.

  As described above, in the ninth invention of the present application, it is only necessary to use the shear pin provided with the planned breaking portion provided so as to penetrate or engage with the first locking base, the spool, and the second locking base. In addition to locking on both sides in the direction, after the pretensioner operation at the time of vehicle sudden deceleration, the two to-be-ruptured portions are sequentially broken to keep only the other side in the axial direction of the torsion bar locked for shaft torsional deformation. One direction can be released. Therefore, the device structure is simplified and the overall device size is reduced compared to the conventional structure that has separate locking mechanisms for normal use and for sudden vehicle deceleration, and disables the normal locking mechanism for sudden vehicle deceleration. Further, the number of parts can be reduced.

  In order to achieve the above object, a seat belt device according to a tenth aspect of the present invention includes a seat belt for restraining a passenger, a seat belt retractor that winds up one side of the seat belt so that the seat belt can be pulled out, and the seat belt. A tongue that is provided, and a buckle device that engages the tongue with the tongue, and the seat belt retractor includes a spool that winds up the seat belt, and a radial direction of the spool. A torsion bar which is disposed on the inner side and is connected to the spool on one side in the axial direction and capable of absorbing the kinetic energy of the occupant by being torsionally deformed by relative displacement between the one side in the axial direction and the other side in the axial direction; The spool is positioned on the other side in the axial direction of the spool, and the spool is wound around the seat belt in a vehicle sudden deceleration state. A pretensioner that generates a rotational driving force for rotating in the direction, and, in a normal state, to prevent the rotation of the torsion bar on the other side in the axial direction and the spool in the pull-out direction of the seat in cooperation with each other. In the vehicle sudden deceleration state, the linkage is canceled and the lock of the spool on the other side in the axial direction of the torsion bar is maintained. A linkage locking mechanism for releasing the lock on the fixed-side member.

  In the tenth invention of the present application, in the normal state, the cooperative locking mechanism provided in the seat belt retractor first rotates the torsion bar in the axial direction on the other side in the seat belt withdrawing direction and the spool in the withdrawing direction of the seat belt. Rotation is blocked in cooperation with each other.

  On the other hand, when the vehicle suddenly decelerates, the pretensioner operates in response to the sudden deceleration, and the spool rotates in the seat belt winding direction by the rotational driving force, thereby improving the restraining force of the occupant by the seat belt. Thereafter, the occupant's body pulls the seat belt with a greater force than the predetermined force due to inertia at the time of sudden deceleration of the vehicle, and the force in the direction of pulling out the seat belt acts on the spool. At the time of deceleration, the linkage between the one side in the axial direction and the other side is canceled, and the lock on the fixed side member on the other side in the axial direction of the torsion bar is maintained while the spool (in other words, one side in the axial direction of the torsion bar) Release the lock to the stationary member. As a result, one side of the torsion bar is rotationally displaced relative to the other side in the axial direction, and occupant kinetic energy can be absorbed by the torsional deformation of the torsion bar (EA mechanism). Further, since the pretensioner is located on the other side of the spool, the operation of the EA mechanism in which one side of the torsion bar is twisted relative to the other side as described above is affected by the operation of the pretensioner. Therefore, stable operation can be ensured.

  As described above, in the tenth invention of the present application, the locking is performed on both sides in the axial direction of the torsion bar in the normal state only by using the cooperative locking mechanism, and the torsion bar is deformed due to torsion deformation of the torsion bar at the time of sudden deceleration of the vehicle. Only the other axial side can be kept locked and the other axial side can be released. Therefore, the retractor device structure is simplified and the retractor is smaller than the conventional structure that has separate locking mechanisms for normal use and for sudden vehicle deceleration, and disables the normal locking mechanism for sudden vehicle deceleration. And the number of parts can be reduced.

  According to the present invention, a stable EA operation that is not affected by the operation of the pretensioner can be ensured without complicating or increasing the size of the device structure.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present embodiment is an example in which the present invention is applied to an automobile seat belt device.

  FIG. 1 is a front view illustrating the entire structure of a seat belt apparatus including a seat belt retractor according to the present embodiment together with a passenger.

  In FIG. 1, a seat belt device 100 is disposed in a vehicle body 108 of a vehicle, and a seat belt 3 for restraining an occupant M to a seat S, and one side of the seat belt 3 are wound so as to be drawable. The seat belt retractor 1 is provided, a tongue 104 slidably provided on the seat belt 3, and a buckle device 105 engaged with the tongue 104.

  As described above, the seat belt 3 is wound on one side by the retractor 1 and is passed through the shoulder anchor 106 on the way, and the other end is pivotally connected to the vehicle body 108 side by a stopper 107. ing.

  2 is a front view showing the overall schematic structure of the seat belt retractor 1, FIG. 3 is a longitudinal sectional view thereof, and FIG. 4 is a right side view of the seat belt retractor 1 as viewed from the IV direction in FIG. FIG. 5 is an exploded perspective view of the seat belt retractor.

  2, 3, 4, and 5, the seat belt retractor 1 is rotatably supported between a U-shaped frame 2 (fixed side member) and both side walls of the frame 2. 3, a spool 4 for winding 3; deceleration sensing means (not shown) that operates by sensing a large vehicle deceleration generated in an emergency; and at least rotation of the spool 4 in the belt drawing direction that is actuated by the deceleration sensing means. A lock starting mechanism 6 for preventing the rotation, and loosely fitted and penetrated in the axial direction inside the spool 4 in the radial direction, and one side of the axial direction (the right side in FIGS. 2 and 3) is connected to the spool 4 and the shaft The torsion bar 7 which can be torsionally deformed by the relative displacement between the one side and the other side (left side in FIGS. 2 and 3) and absorb the kinetic energy of the occupant, and the spring force of the spiral spring (not shown) Spring means (not shown) for constantly urging the belt 4 in the belt winding direction and rotatably supported by the frame 2 on one side (right side in FIGS. 2 and 3) of the torsion bar 7 and the spool 4 in the axial direction. The right locking base 14R (second locking base, second locking member) and a pawl for being rockably held by the right locking base 14R and for locking the right locking base 14R to the frame 2 according to the deceleration of the vehicle 13R (second pawl, second locking member) and the other side of the torsion bar 7 and spool 4 (left side in FIGS. 2 and 3) are rotatably supported by the frame 2, and the other side in the axial direction of the torsion bar 7 Left locking base 14L (first locking base, first locking member) fixed (connected) to (left side in FIGS. 2 and 3), and the left rocking base A pawl 13L (first pawl, first locking member) for holding the left locking base 14L to the frame 2 in accordance with the deceleration of the vehicle, the torsion bar 7 and the spool 4 Is located on the other side in the axial direction (the left side in FIGS. 2 and 3), and operates during sudden deceleration of the vehicle such as in an emergency to generate a rotational driving force for rotating the spool 4 in the winding direction of the seat belt 3. The left locking base 14L, the spool 4, and the locking base 14R are connected in the axial direction (FIGS. 2 and 3) so as to connect the pretensioner 11 (not shown) that transmits to the left locking base 14L and the pawl 13L and the pawl 13R. (In this example, the locking bases 14L and 14R pass through the through holes H1 and H2, and the spool 4 in the middle and left and right directions) Has a shear pin 50 (pin member) provided on the concave groove 4A.

  The spool 4 is always urged in the seat belt winding direction via the torsion bar 7 by the spring force of the spring means. Since the spool 4 rotates integrally with the left locking base 14L and the right locking base 14R while the shear pin 50 is not broken as will be described later, the left locking base 14L and the right locking base 14R together with the spool 4 are seat belts. It can also be said that “spool means” is configured to take up and pull out 3. From this viewpoint, these three configurations can be regarded as a structure in which the spool means is divided into three in the axial direction.

  The lock starting mechanism 6 is the same as that already known as this type, and includes a lock gear 6a provided on one side of the torsion bar 7 in the axial direction (the right side in FIGS. 2 and 3). The lock gear 6a normally rotates integrally with the locking base 14R, stops when the deceleration sensing means operates during sudden deceleration of the vehicle, generates a relative rotational difference with the locking base 14R, and causes the pawl 13R to The inner teeth 19R on the side walls are engaged (engaged), thereby preventing the right locking base 14R from rotating in the seat belt pull-out direction.

  That is, for example, when a vehicle sensor is used as the acceleration sensing means, as described in Japanese Patent No. 3192198 and the like, when the weight of the weight pivotally supported by the sensor case has a deceleration exceeding a predetermined value, the balance of force is achieved. When the actuator is broken, the actuator is operated with an actuator, and the rotation of the lock gear 6a is suppressed by reaching a position where the actuator meshes with the lock gear 6a. Further, when a webbing sensor is used as the acceleration sensing means, the lock gear 6a holds one end of the hook spring and pivotally supports the flywheel, as described in Japanese Patent No. 3192198 and the like. When the angular velocity of 6a becomes equal to or higher than a predetermined value, the tip of the flywheel reaches and meshes with the internal gear of the retainer, and the rotation of the lock gear 6a is suppressed.

  When the rotation of the lock gear 6a is suppressed as described above, a relative rotation (phase difference) occurs between the locking base 14R and the lock gear 6a. Therefore, the lock gear 6a is placed on the locking base 14R using this phase difference. The pawl 13R is rotated by the phase difference and engaged with the internal teeth 19R. At this time, since the pawl 13R and the pawl 13L are connected by the shear pin 50 as described above, the pawl 13R is engaged with the inner teeth 19R on the side wall of the frame 2 by the lock gear 6a as described above, and the pawl 13L is also framed. It engages with the inner teeth 19L of the second side wall.

  A torque transmission pinion 51 is fixed to the left locking base 14 </ b> L, and the rotational drive torque of the pretensioner 11 is transmitted to the pinion 51.

  The shear pin 50 is provided with two scheduled break portions C1 and C2 that break at a predetermined timing according to the applied load, in the vicinity of the left locking base 14L and the vicinity of the right locking king base 13R. The two scheduled break portions C1 and C2 of the shear pin 50 are preliminarily broken based on their shapes, materials, etc. so that the balance with the driving torque generated by the pretensioner 11 has a breaking behavior as described below. Strength is set.

  In the above, the pawls 13L and 13R and the shear pin 50 prevent the rotation of the torsion bar in the axial direction on the other side and the spool in the pull-out direction of the seat belt in cooperation with each other in the normal state. In the vehicle sudden deceleration state, the linkage is canceled, and the lock to the fixed side member on the other side in the axial direction of the torsion bar is maintained while the spool is fixed to the fixed side member. A linkage locking mechanism for releasing the lock is configured.

  The operation and effect of the seat belt retractor 1 of the present embodiment configured as described above will be described below with reference to FIG.

  In normal times, the two planned fracture portions C1 and C2 of the shear pin 50 are in a substantially unbroken state where they are not substantially broken, and the spool 4 is connected to the left locking base 14L and the right locking base 14R via the shear pin 50. When the seat belt 3 is not attached, the seat belt 3 is completely wound by the urging force of the spring means 8.

  When the seat belt 3 is pulled out at a normal speed for wearing, the spool 4 rotates in the seat belt pulling direction, and the seat belt 3 is pulled out smoothly. After a tongue (not shown) slidably provided on the seat belt 3 is inserted into and locked to a buckle fixed to the vehicle body, the seat belt 3 pulled out is wound around the spool 4 by the urging force of the spring means 8. The seat belt 3 is fitted to such an extent that it does not give the passenger a feeling of pressure.

  When the seat belt 3 is to be pulled out suddenly, the deceleration sensing means operates with a large deceleration generated at this time, and the operation of the deceleration sensing means causes the lock activation mechanism 6 to operate as described above. The pawls 13L and 13R are rotated and engaged with the internal teeth 19L and 19R on the side wall of the frame 2, respectively. As a result of the locking operations of the pawls 13L and 13R, the locking bases 14L and 14R are locked to the frame 2, respectively. As a result, the spool 4 connected to the locking bases 14L and 14R via the shear pin 50 Rotation to is prevented.

  On the other hand, when the vehicle suddenly decelerates, such as in an emergency, the pretensioner 11 operates in response to the sudden deceleration, and the rotational driving force is transmitted to the left locking base 14L via the pinion 51 (in FIG. 6A). This rotational driving force is transmitted to the spool 4 via the torsion bar 7 (see (B) in FIG. 6A), and the spool 4 rotates by a predetermined amount in the seat belt 3 winding direction. However, the restraining force of the occupant by the seat belt 3 is improved (see (C) in FIG. 6A). In the first stage immediately after the sudden deceleration of the vehicle, as in the normal state, the two fracture planned portions C1 and C2 of the shear pin 50 are in an unbroken state (at least an almost unbroken state that is not almost broken), and the spool 4 is rocked to the left and right. On the other hand, the pawls 13L, 13R lock the left and right locking bases 14L, 14R to the frame 2 in the same manner as described above according to the deceleration of the vehicle. The rotation of the belt 3 in the drawing direction is prevented.

  Thereafter, the body of the occupant of the vehicle pulls the seat belt 3 with a greater force than the predetermined force due to inertia at the time of sudden deceleration of the vehicle (see (D) in FIG. 6B), and the force in the seat belt pulling direction with respect to the spool 4 Acts greatly (see (E) in FIG. 6B), but the two planned fracture portions C1 and C2 of the shear pin 50 are broken in the second stage during the sudden deceleration of the vehicle (FIG. 6). (See (F) in (b)) The connection between the one side (the right side in FIGS. 6A and 6B) and the other side (the left side in FIGS. 6A and 6B) is canceled, The lock to the locking bases 14L and 14R is released. As a result, the axially one side (the right side in FIGS. 6A and 6B) of the torsion bar 7 connected to the spool 4 is the other axial side (the left side in FIGS. 6A and 6B). = At this time, it is fixed to the left locking base 14L locked by the pawl 13L as described above.Refer to rotational displacement relative to (G) in FIG. The deformation (torsion torque) can absorb the occupant kinetic energy and limit the load applied to the seat belt 3 (EA mechanism).

  At this time, the pretensioner 11 is located on the other axial side of the spool 4 (left side in FIGS. 6A and 6B) and is connected to the left locking base 14L as described above. The operation of the EA mechanism in which one side (the right side in FIGS. 6A and 6B) of the torsion bar 7 rotates relative to the other side (the left side in FIGS. 6A and 6B) 7L is rotated. A stable operation can be ensured without being affected by the operation of the pretensioner 11.

  As described above, in the seat belt retractor 1 of the present embodiment, only the shear pin 50 provided with the planned breaking portions C1 and C2 that penetrate or engage with the left locking base 14L, the spool 4, and the locking base 14R is used. In normal operation, both sides in the axial direction are locked, and in the second stage when the vehicle is suddenly decelerated, the torsion bar 7 is torsionally deformed by breaking both of the two expected breakage points C1 and C2. Only the other axial side of the bar 7 (left side in FIGS. 6 (a) and 6 (b)) can be kept locked, and the other axial side (right side in FIGS. 6 (a) and 6 (b)) can be released. Therefore, the device structure of the seat belt retractor 1 is simplified compared to the conventional structure that includes separate locking mechanisms for normal use and for sudden vehicle deceleration, and disables the normal locking mechanism for sudden vehicle deceleration. The entire apparatus can be reduced in size and the number of parts can be reduced.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit and technical scope of the present invention. For example, another behavior different from the above can be set according to the setting of the breaking strength of the two scheduled cutting portions in the shear pin.

  FIG. 7 is an exploded perspective view for explaining the configuration of such a modification, and corresponds to FIG. 2 of the above embodiment. In this case, the pawl 13L ′ (third pawl) as the first locking member is provided on the left locking base 14L so as to be able to rotate (swing), and the left locking base 14L by a spring (a leaf spring in this example) 52. It is urged in the locking direction to perform the locking operation.

  The two planned fracture portions C1 'and C2' of the shear pin 50 'of this modification are substantially unbroken so as to maintain the locked state of the spool 4 to the left and right locking bases 14L and 14R in a normal state. Respectively, when the pretensioner 11 is operated in the vehicle suddenly decelerating state, only the planned breaking portion C1 ′ in the vicinity of the left locking base 14L is broken to release the locking state of the spool 4 to the left locking base 14L. The rupture strengths of the planned rupture portions C1 'and C2' are set so that the rupture planned portion C2 'in the vicinity of the right locking base 14R is also ruptured to release the locking state of the spool 4 to the right locking base 14R ing.

  Operations and effects of this modification will be described with reference to FIG. 8 corresponding to FIG. 6 of the above embodiment. In the present modification shown in FIG. 8, when the vehicle suddenly decelerates, such as in an emergency, first, the pretensioner 11 is activated in response to the sudden deceleration, and the left locking base 14L is connected to the left locking base 14L via the pinion 51 as in the above embodiment. The rotational driving force is transmitted (see (H) in FIG. 8A), and this rotational driving force is transmitted to the spool 4 via the torsion bar 7 (see (I) in FIG. 8A). Rotates in the winding direction of the seat belt 3 by a predetermined amount (see (J) in FIG. 8A), and the restraining force of the occupant by the seat belt 3 is improved. In this modified example, during the operation of the pretensioner 11, the planned fracture portion C1 ′ in the vicinity of the left locking base 14L of the two planned fracture portions C1 ′ and C2 ′ of the shear pin 50 ′ is first broken ( 8 (a) (see (K)), the locking base 14L and the spool 4 are unlocked, but the locking base 14L itself is fixed by a pawl 13L 'biased by a spring 52 in the locking direction. (See (L) in FIG. 8A. As a result of such a locking method, the pawl 13L 'can be engaged more quickly than the pawl 13L of the above embodiment). On the other hand, at this time, the opposite pawl 13R is in an unbroken state (at least in an almost unbroken state that is not almost broken), and the spool 4 is connected to the right locking base 14R. Since 13R locks the right locking base 14R to the frame 2 according to the above-described operating principle, the spool 4 is prevented from rotating in the pull-out direction of the seat belt 3 as in the above embodiment.

  Thereafter, the body of the occupant of the vehicle pulls the seat belt 3 with a large force greater than a predetermined force due to inertia at the time of sudden deceleration of the vehicle (see (M) in FIG. 8B), and the force in the seat belt pulling direction with respect to the spool 4 However, the remaining fracture portion C2 'of the shear pin 50' is broken here to unlock the spool 4 from the right locking base 14R (see (P) in FIG. 8B). . As a result, the axially one side (the right side in FIGS. 8A and 8B) of the torsion bar 7 connected to the spool 4 is the other axial side (the left side in FIGS. 8A and 8B). = At this time, the rotational displacement is relatively made with respect to the left locking base 14L locked by the pawl 13L 'as described above, and the occupant kinetic energy is reduced by the torsional deformation (torsional torque) of the torsion bar 7. The load absorbed and applied to the seat belt 3 can be limited (EA mechanism).

  At this time, the pretensioner 11 is located on the other axial side of the spool 4 (left side in FIGS. 8A and 8B) and connected to the left locking base 14L as described above. The operation of the EA mechanism in which one side (the right side in FIGS. 8A and 8B) of the torsion bar 7 rotates relative to the other side (the left side in FIGS. 8A and 8B) 7L A stable operation can be ensured without being affected by the operation of the pretensioner 11.

  As described above, also in the present modified example, as in the above embodiment, the shear pin 50 including the planned fracture portions C1 ′ and C2 ′ that penetrate or engage with the left locking base 14L, the spool 4, and the locking base 14R. ′ Is used to lock both sides in the axial direction under normal conditions, and after the pretensioner 11 is actuated during sudden deceleration of the vehicle, the torsion bar 7 is torsionally deformed by sequentially breaking the two portions to be broken C1 'and C2'. Therefore, only the other axial side of the torsion bar 7 (the left side in FIGS. 8A and 8B) can be kept locked, and the one axial side (the right side in FIGS. 8A and 8B) can be released. . Therefore, the device structure of the seat belt retractor 1 is simplified compared to the conventional structure that includes separate locking mechanisms for normal use and for sudden vehicle deceleration, and disables the normal locking mechanism for sudden vehicle deceleration. The entire apparatus can be reduced in size and the number of parts can be reduced.

It is a figure showing the whole structure of the seatbelt device of one embodiment of the present invention with a passenger. It is a front view showing the whole schematic structure of a seatbelt retractor. It is a longitudinal section showing the whole outline structure of a seatbelt retractor. It is the right view seen from IV direction in FIG. It is a disassembled perspective view of this seatbelt retractor. It is a figure showing operation | movement and an effect of a seatbelt retractor. It is a disassembled perspective view explaining the structure of the modification which shows a different fracture | rupture behavior. It is a figure showing operation | movement and an effect of a seatbelt retractor.

Explanation of symbols

1 Seat belt retractor 2 Frame (fixed side member)
3 seat belt 4 spool 7 torsion bar 11 pretensioner 13L pawl (first pawl, first locking member, cooperative locking mechanism)
13L 'pawl (3rd pawl, 1st locking member, cooperative locking mechanism)
13R pawl (second pawl, second locking member, cooperative locking mechanism)
14L left locking base (first locking base, first locking base
Member)
14R right locking base (second locking base, second rocking
Member)
50 Shear pin (pin member, cooperative locking mechanism)
50 'shear pin (pin member, linkage locking mechanism)
100 seat belt device 104 tongue 105 buckle device M passenger

Claims (10)

A spool that winds up the seat belt;
This spool is arranged on the inner side in the radial direction and one side in the axial direction is connected to the spool, and is twisted by the relative displacement between the one side in the axial direction and the other side in the axial direction to absorb the kinetic energy of the occupant. Possible torsion bars,
A pretensioner that is located on the other side in the axial direction of the spool and generates a rotational driving force for rotating the spool in the seat belt winding direction in a vehicle sudden deceleration state;
In normal times, the torsion bar is locked to the stationary member of the vehicle so as to prevent the rotation of the spool in the other side in the axial direction and the spool in the pull-out direction of the seat belt in cooperation with each other; In the state, a linkage locking mechanism that cancels the lock of the spool to the fixed side member while canceling the linkage and maintaining the lock on the fixed side member on the other axial side of the torsion bar. A seat belt retractor comprising: The seat belt retractor according to claim 1,
A first locking member located on the other axial side of the spool and connected to the other axial side of the torsion bar;
The pretensioner applies a rotational driving force to the first locking member for rotating the spool in the seat belt winding direction in the vehicle sudden deceleration state;
The cooperative locking mechanism includes a first locking member for locking the first locking member to a stationary member of the vehicle. The seat belt retractor according to claim 2,
The seat belt retractor according to claim 1, wherein the first locking member is a pawl that is rotatably provided on the first locking member and that performs a locking operation of the first locking member in accordance with a deceleration of the vehicle. The seat belt retractor according to claim 2,
The seat belt is characterized in that the first locking member is a pawl that is rotatably provided on the first locking member and is urged by a spring in a locking direction of the first locking member to perform a locking operation. Retractor. The seat belt retractor according to any one of claims 2 to 4,
A second locking member located on one axial side of the spool;
The cooperative locking mechanism is rotatably provided on the second locking member, and the second locking member is provided on a stationary member of the vehicle, and the second locking member is provided. The seat belt retractor according to claim 5,
The seat belt retractor according to claim 1, wherein the second locking member is a pawl that is rotatably provided on the second locking member and that performs a locking operation of the second locking member in accordance with a deceleration of the vehicle. The seat belt retractor according to claim 5 or 6,
The linkage locking mechanism is provided so as to penetrate or engage at least the spool in the axial direction in order to connect the first locking member and the second locking member, and can be broken according to a load. A seat belt retractor comprising a pin member having at least one scheduled break portion. A spool that winds up the seat belt;
This spool is arranged on the inner side in the radial direction and one side in the axial direction is connected to the spool, and is twisted by the relative displacement between the one side in the axial direction and the other side in the axial direction to absorb the kinetic energy of the occupant. Possible torsion bars,
A first locking base located on the other axial side of the spool and connected to the other axial side of the torsion bar;
A first pawl that is pivotally provided on the first locking base and locks the first locking base to a stationary member of the vehicle according to a deceleration of the vehicle;
A second locking base located on one axial side of the spool;
A second pawl which is rotatably provided on the second locking base and locks the second locking base to a stationary member of the vehicle according to a deceleration of the vehicle;
A pretensioner that is located on the other side in the axial direction of the spool, generates a rotational driving force for rotating the spool in the seat belt winding direction in a vehicle rapid deceleration state, and transmits the rotational driving force to the first locking base; ,
In order to connect the first pawl and the second pawl, the first locking base, the spool, and the second locking base are provided so as to penetrate or engage in the axial direction, and in accordance with the acting load. A shear pin provided at two locations, a vicinity of the first rocking base and a vicinity of the second rocking base, to be broken at predetermined timings;
The two planned break portions of this shear pin are
In a normal state and in the first stage of the pretensioner operation in the vehicle rapid deceleration state, a substantially unbroken state is maintained so as to maintain the locking state of the spool to the first and second locking bases. And in the second stage after the first stage, each breaks based on the force of the vehicle occupant to rotate the seat belt in the pull-out direction acting on the spool. The seat belt retractor is characterized in that the breaking strength of the planned breaking portion is set so as to release the locking state of the spool to the second locking base. A spool that winds up the seat belt;
This spool is arranged on the inner side in the radial direction and one side in the axial direction is connected to the spool, and is twisted by the relative displacement between the one side in the axial direction and the other side in the axial direction to absorb the kinetic energy of the occupant. Possible torsion bars,
A first locking base located on the other axial side of the spool and connected to the other axial side of the torsion bar;
A first locking base that is rotatably provided on the first locking base and is biased by a spring in the locking direction of the first locking base to perform a locking operation is a first lock for locking the first locking base to a stationary member of the vehicle. 3 pawls,
A second locking base located on one axial side of the spool;
A second pawl which is rotatably provided on the second locking base and locks the second locking base to a stationary member of the vehicle according to a deceleration of the vehicle;
A pretensioner that is located on the other side in the axial direction of the spool, generates a rotational driving force for rotating the spool in the seat belt winding direction in a vehicle rapid deceleration state, and transmits the rotational driving force to the first locking base; ,
In order to connect the first pawl and the third pawl, the first locking base, the spool, and the second locking base are provided so as to penetrate or engage in the axial direction, and depending on the acting load. A shear pin provided at two locations, a vicinity of the first rocking base and a vicinity of the second rocking base, to be broken at a predetermined timing;
The two planned break portions of this shear pin are
In a normal state, the substantially unbroken state is maintained so as to maintain the locked state of the spool to the first or second locking base; and when the pretensioner is operated in the vehicle sudden deceleration state, the first Only the planned fracture portion in the vicinity of the locking base is broken to release the locking state of the spool to the first locking base, and then the planned fracture portion in the vicinity of the second locking base is also broken to form the second A seat belt retractor characterized in that the breaking strengths of the portions to be broken are set so as to release the locked state of the spool to the locking base. A seat belt to restrain the passenger,
A seat belt retractor that winds up one side of the seat belt so that it can be pulled out;
A tongue provided on the seat belt;
A buckle device for engaging a passenger with the seat belt by engaging with the tongue;
The seat belt retractor is
A spool for winding the seat belt;
This spool is arranged on the radially inner side and one side in the axial direction is connected to the spool, and is twisted by the relative displacement between the one side in the axial direction and the other side in the axial direction to absorb the kinetic energy of the occupant. Possible torsion bars,
A pretensioner that is located on the other side in the axial direction of the spool and that generates a rotational driving force for rotating the spool in the seat belt winding direction in a vehicle rapid deceleration state;
During normal times, the torsion bar is locked to the stationary side member of the vehicle so as to prevent the rotation of the spool in the other side in the axial direction and the spool in the direction of pulling out the seat belt in cooperation with each other; In the state, a linkage locking mechanism that cancels the lock of the spool to the fixed side member while releasing the linkage and maintaining the lock to the fixed side member on the other axial side of the torsion bar. A seat belt device comprising:

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