JP2005001648A - Webbing take-up device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a webbing take-up device having a mechanism capable of forcedly releasing an engagement of a spool with a lock member without enlarging the size of the spool. <P>SOLUTION: In the webbing take-up device, a lock pawl 72 is supported on a support part 70 of a cam plate 66 from below. When a piston 82 is pushed out from a cylinder 80 in a state where the lock pawl 72 is engaged with a ratchet wheel 40, the piston 80 impinges on an abutting piece 78 of a cam plate 66, and the cam plate 66 is turned thereby. When a support part 70 is moved with the cam plate 66 being turned, the lock pawl 72 loses the support from below, and the support balance of the lock pawl 72 being kept by the support from below and the interference from an interference piece 73 collapses. The lock pawl 72 is turned downward and the engagement with the ratchet wheel 40 is released. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a webbing retractor that constitutes a seat belt device for restraining the body of an occupant seated on a seat of a vehicle or the like with a long belt-like webbing belt.

  A seat belt device that restrains the body of an occupant seated in a vehicle seat with a long belt-like webbing belt includes a webbing take-up device that is fixed to the vehicle body on the side of the seat. The webbing take-up device includes, for example, a spool whose axial direction is substantially in the vehicle front-rear direction, and the longitudinal base end side of the webbing belt is locked to the spool. The spool accommodates a webbing belt wound around the outer periphery of the spool.

  Further, the webbing take-up device is provided with a biasing member such as a torsion coil spring that biases the spool in the winding direction in which the webbing belt is wound up. In the state where the webbing belt is mounted on the occupant's body while being wound up, the slack of the webbing belt is removed by the urging force of the urging member. In this type of webbing take-up device, the webbing belt taken up on the spool is pulled out by pulling the tongue plate provided at the intermediate portion in the longitudinal direction of the webbing belt against the biasing force of the biasing member. A webbing belt can be mounted by holding the tongue plate on a buckle device provided on the side of the seat opposite to the webbing take-up device.

  On the other hand, in the webbing take-up device, when the occupant's body pulls the webbing belt with a force exceeding a predetermined magnitude due to inertia at the time of sudden deceleration of the vehicle, the webbing belt is slightly deformed while plastically deforming the energy absorbing member. A so-called force limiter mechanism that allows the drawing and absorbs and reduces the force applied to the body of the occupant by the webbing belt is provided, and an example thereof is disclosed in Patent Document 1 below.

  A force limiter mechanism of a webbing take-up device disclosed in Patent Document 1 is provided with a bottomed cylindrical sleeve inside a cylindrical spool (referred to as “belt winding shaft” in Patent Document 1). Is accommodated substantially coaxially with respect to the spool, and a torsion bar is accommodated substantially coaxially with respect to the sleeve and the spool inside the sleeve.

  On the bottom side of the sleeve, the sleeve and the torsion bar are integrally connected via a profile head. On the other hand, on the open end side of the sleeve, a first connection claw corresponding to the torsion bar and a second connection claw corresponding to the sleeve are accommodated inside the spool.

  The first connecting claw meshes with the external ratchet teeth formed on the outer peripheral portion of the torsion bar by the operation of a control device including an electromagnet or the like, whereby the spool and the torsion bar are engaged with each other. This is a structure that is mechanically connected through the connecting claws. On the other hand, the second connecting claw meshes with the external ratchet teeth formed on the outer peripheral portion of the sleeve by the operation of the control device, whereby the spool and the sleeve are interposed via the second connecting claw. And mechanically connected.

  Accordingly, the rotational force of the spool in the rotational direction of the spool when the webbing belt is pulled out (hereinafter, this rotational direction is referred to as the “drawing direction” for the sake of convenience) is the one in which the connecting claws of the torsion bar and sleeve are engaged. It is transmitted to. For this reason, in a state where the lock mechanism is activated in a vehicle sudden deceleration state or the like and the rotation of the profile head in the pull-out direction is restricted, the limit load based on the rigidity of the torsion bar and the sleeve with which the coupling claw is engaged When a rotational force equal to or greater than (force limiter load) is applied to the spool, the direction in which the connecting claws are engaged by the spool is twisted and deformed. Accordingly, the webbing belt is allowed to be pulled out slightly by the amount of the torsional deformation, and the force applied to the occupant's body by the webbing belt is absorbed and reduced.

  Here, as described above, the magnitude of the limit load is basically based on the rigidity of the torsion bar and the sleeve with which the coupling claw is engaged. Therefore, if any one of the torsion bar and the sleeve is meshed with the connecting claw, the limit load becomes a magnitude based on the rigidity of either one. On the other hand, if both the torsion bar and the sleeve are meshed with the connecting claw, the limit load is based on the rigidity of both the torsion bar and the sleeve.

Thus, the force limiter mechanism of the webbing take-up device disclosed in Patent Document 1 can vary the magnitude of the limit load (force limiter load).
Special table 2000-512594 gazette

  By the way, in the structure disclosed in Patent Document 1, a structure for switching a limit load (force limiter load), in other words, a lock mechanism for restricting rotation of the profile head in the pull-out direction, and a spool are provided. A structure for mechanically connecting or releasing the connection via a torsion bar or a sleeve is accommodated in the spool. This complicates the structure of the spool and increases the size of the spool. The entire webbing take-up device is enlarged.

  An object of the present invention is to obtain a webbing take-up device having a mechanism capable of forcibly releasing the engagement between a spool and a lock member without enlarging the spool in consideration of the above fact.

  In the webbing take-up device according to the first aspect of the present invention, the base end side of the long belt-like webbing belt is locked, and the webbing belt is rotated by rotation in the winding direction which is one of the directions around the axis. A substantially cylindrical spool that is wound from the proximal end side, and provided in a lockable position outside the spool at one axial end side of the spool so as to be movable in the locking direction. Alternatively, it includes a first lock member that indirectly engages to lock the spool and restricts the rotation of the spool in the pull-out direction opposite to the winding direction, and detects a predetermined state of the vehicle A lock mechanism that moves the first lock member in the lock direction, and supports the first lock member at the lockable position and releases the support to the lockable position. And a support means for detaching the first lock member to a position where the engagement with the spool is impossible, and the support means is forcibly displaced when a predetermined condition is satisfied, and the first means by the support means is used. Release means for forcibly releasing the support state of the lock member.

  According to the webbing take-up device of the present invention as set forth in claim 1, the occupant sits on the seat of the vehicle, pulls out the webbing belt wound around the spool, and further pulls out the webbing belt drawn out. Is put on the body, for example, the tongue plate provided on the webbing belt is engaged with the buckle device, so that the webbing belt is attached to the occupant body.

  On the other hand, when it is detected by the lock mechanism that the vehicle is in a predetermined state and the lock mechanism is activated, the first lock member supported by the support means moves in the lock direction at the lockable position on the one axial end side of the spool. To do. In this way, when the first lock member moves in the locking direction, the first lock member engages directly or indirectly with the spool. As a result, the spool is locked and the rotation of the spool in the pull-out direction is restricted.

  For example, when the vehicle is in a state where the vehicle is suddenly decelerated, the body of the occupant who intends to move substantially forward of the vehicle due to inertia in the vehicle suddenly decelerates the worn webbing belt. pull. Basically, the webbing belt is pulled, so that the portion wound around the spool is pulled out while the spool rotates in the pull-out direction.

  However, the pulling of the webbing belt is regulated by locking the rotation of the spool in the drawing direction as described above. Thus, the occupant's body is securely held by the webbing belt attached to the occupant's body, and movement of the occupant's body toward the front side of the vehicle substantially due to inertia in the vehicle sudden deceleration state is restricted.

  On the other hand, in the webbing take-up device according to the present invention, the first lock member is supported by the support means at the lockable position. Here, when a predetermined condition is satisfied and the release means is operated, the support means is forcibly displaced by the release means. Due to the displacement of the support means, the support of the first lock member by the support means is forcibly released. When the support by the support means is released, the first lock member is released from the lockable position, and the first lock member is displaced to a position where the above-described spool cannot be directly or indirectly engaged.

  Therefore, in the webbing take-up device according to the present invention, the lock of the spool by the first lock member can be forcibly released.

  By the way, for example, the spool is formed in a hollow and substantially cylindrical shape along the axial direction, and an energy absorbing member referred to by a name such as a torsion bar or a torsion shaft is provided in the inside thereof, and more than the axially intermediate portion of the spool. The spool and the energy absorbing member are connected at the other end in the axial direction, and the webbing belt is pulled with a tensile force exceeding the limit load based on the rigidity of the energy absorbing member with the energy absorbing member locked at the one axial end of the spool. There is a so-called “force limiter mechanism” in which the energy absorbing member is deformed to relieve the restraining force of the webbing belt.

  The present invention is applied to a webbing take-up device having such a force limiter mechanism, and the first lock member is engaged with the energy absorbing member at one axial end of the spool to indirectly lock the energy absorbing member. When the configuration is such that the rotation of the spool in the pull-out direction is restricted, the lock by the first lock member can be forcibly released halfway by operating the release means.

  Further, as described above, the unlocking in the case where the releasing means is activated is due to dropping from the lockable position by losing the support by the supporting means. Therefore, the engagement between the first lock member and the energy absorbing member is configured to engage the gear and the pawl, and the first lock member and the energy absorbing member are in a so-called “biting” state in the engaged state. Even if it is, the lock can be reliably released by dropping the first lock member from the lockable position.

  Furthermore, when the present invention is applied to the webbing take-up device having the force limiter mechanism as described above, for example, if the release unit is operated after a predetermined time has elapsed since the lock mechanism is operated, When the predetermined time elapses from the locked state, the lock by the first lock member can be released.

  Therefore, in this state, if the rotation of the energy absorbing member in the pull-out direction is not restricted on the other axial end side of the spool from the connecting portion, the energy absorbing member can freely rotate together with the spool.

  On the other hand, the rotation of the energy absorbing member in the pull-out direction is restricted at one end in the axial direction of the spool relative to the connecting portion, and the first limit load is more than that in the connecting portion due to the rotation restriction at one end in the axial direction. If it is based on both the rigidity of the energy absorbing member on the other end side and the rigidity of the energy absorbing member on the one end side with respect to the connecting portion, the energy absorption on the other end side in the axial direction of the energy absorbing member By releasing the lock of the member, the energy absorbing member can be deformed with a second limit load smaller than the first limit load after a predetermined time has elapsed after the lock mechanism is activated.

  On the other hand, if the release means is operated before the lock mechanism is operated, even if the lock mechanism is operated, the first lock member cannot be engaged with the energy absorbing member. For this reason, in the case of this configuration, the first lock member does not restrict the rotation of the energy absorbing member in the pull-out direction.

  Accordingly, in this state, the rotation of the energy absorbing member in the pulling direction is restricted at one end side from the connecting portion, and the rigidity of the energy absorbing member at the other end side from the connecting portion is the first limit load, and the connecting portion If it is based on both of the rigidity of the energy absorbing member on one end side than the other end side in the axial direction of the energy absorbing member, the lock of the energy absorbing member is released, so that the operation of the lock mechanism The energy absorbing member can be deformed with the second limit load immediately after the start.

  Thus, if the present invention is applied to the webbing take-up device having the force limiter mechanism as described above, the first and second limit loads for deforming the energy absorbing member can be selectively switched. If the operation timing of the release means is set after the lock mechanism is activated, the lock can be released during the deformation of the energy absorbing member, and the energy absorbing member can be deformed at the second limit load less than the first limit load.

  In addition, if the present invention is applied to the webbing take-up device having the force limiter mechanism as described above, the first lock member is basically provided at a lockable position outside the spool. It is sufficient to provide only the energy absorbing member. Thereby, in spite of having the effect | action demonstrated until now, the enlargement of a spool is suppressed effectively and the mechanical structure of a spool is simplified.

  A webbing take-up device according to a second aspect of the present invention is the webbing retractor according to the first aspect of the present invention, wherein the webbing take-up device is provided inside the spool formed in a hollow and substantially cylindrical shape penetrating along the axial direction. An energy absorbing member that is integrally connected to the spool at a connecting portion formed on an intermediate portion or the other end side along the axial direction, and that absorbs energy by deformation around the shaft, in the locking direction The first locking member is directly or indirectly engaged with the energy absorbing member at one end side in the axial direction with respect to the connecting portion by the movement of the connecting portion to restrict the rotation of the energy absorbing member in the pulling direction. It is characterized by.

  According to the webbing retractor according to the second aspect of the present invention, when the lock mechanism detects that the vehicle is in a predetermined state and the lock mechanism is activated, the lockable position on one end side in the axial direction of the spool. Thus, the first lock member supported by the support means moves in the lock direction. Thus, when the first locking member moves in the locking direction, the first locking member engages directly or indirectly with the energy absorbing member, and the first locking member moves the energy absorbing member at one axial end side of the spool. Lock it. Thereby, rotation to the drawing-out direction of an energy absorption member is controlled.

  The energy absorbing member is integrally connected to the spool at a connecting portion provided at an intermediate portion or the other end side along the axial direction of the spool. For this reason, the rotation of the energy absorbing member in the pull-out direction is locked, so that the rotation of the spool in the pull-out direction is indirectly locked.

  As a result, pulling out of the webbing belt from the spool is restricted, and the body of the occupant who is about to move to the front side of the vehicle due to inertia in a vehicle sudden deceleration state or the like can be reliably held by the webbing belt.

  In this locked state, the rotation of both the spool and the energy absorbing member in the drawing direction is basically restricted. However, when the webbing belt is pulled with a load larger than the first limit load based on the rigidity of the energy absorbing member on the other end side in the axial direction of the spool from at least the connecting portion, a rotational force in the pulling direction is applied to the spool. The energy absorbing member is twisted by rotating relative to the both ends (that is, both ends along the axial direction of the spool) of the connecting portion with the spool, whereby the energy absorbing member is deformed.

  Thus, the restraining force which a webbing belt gives to a passenger | crew's body becomes weak because an energy absorption member deform | transforms.

  On the other hand, in the webbing take-up device according to the present invention, the first lock member is supported by the support means at the lockable position. Here, when a predetermined condition is satisfied, the supporting means is forcibly displaced by the releasing means. Due to the displacement of the support means, the support of the first lock member by the support means is forcibly released. When the support by the support means is released, the first lock member is disengaged from the lockable position and displaced to a position where engagement with the energy absorbing member is impossible.

  For this reason, in the webbing take-up device according to the present invention, for example, if the release mechanism is operated after a lapse of a predetermined time after the lock mechanism is operated, the first time is reached when the predetermined time elapses from the locked state. The lock by the lock member can be released.

  Therefore, in this state, if the rotation of the energy absorbing member in the pull-out direction is not restricted at one end side in the axial direction of the spool from the connecting portion, the energy absorbing member can freely rotate together with the spool.

  On the other hand, the rotation of the energy absorbing member in the pull-out direction is restricted on the other axial end side of the spool from the connecting portion, and the first limit load is connected to the connecting portion by the rotation restriction on the other axial end side. If the energy absorption member is based on both the rigidity of the energy absorption member on the other end side and the rigidity of the energy absorption member on the one end side than the connecting portion, the energy on the one end side in the axial direction of the energy absorption member By releasing the lock of the absorbing member, the energy absorbing member can be deformed with a second limit load smaller than the first limit load after a predetermined time has elapsed since the lock mechanism was activated.

  On the other hand, if the release means is operated before the lock mechanism is operated, even if the lock mechanism is operated, the first lock member cannot be engaged with the energy absorbing member. For this reason, in the case of this configuration, the first lock member does not restrict the rotation of the energy absorbing member in the pull-out direction.

  Therefore, in this state, the rotation of the energy absorbing member in the pull-out direction is restricted at one end side from the connecting portion, and the first limit load is higher than the rigidity of the energy absorbing member at one end side from the connecting portion, and from the connecting portion. Is also based on both the rigidity of the energy absorbing member on the other end side, the lock of the energy absorbing member on the one end side in the axial direction of the energy absorbing member is released, and the operation of the lock mechanism starts. Immediately after that, the energy absorbing member can be deformed by the second limit load.

  Thus, in the webbing take-up device according to the present invention, the first and second limit loads for deforming the energy absorbing member can be selectively switched, and in particular, the operation timing of the release means is adjusted after the lock mechanism is activated. If set, the energy absorbing member can be unlocked during the deformation of the energy absorbing member and the energy absorbing member can be deformed at the second limit load less than the first limit load.

  Further, in the webbing take-up device according to the present invention, the first lock member is basically provided at the lockable position outside the spool, so that basically only the energy absorbing member needs to be provided inside the spool. Thereby, in spite of having the effect | action demonstrated until now, the enlargement of a spool is suppressed effectively and the mechanical structure of a spool is simplified.

  The webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the second aspect of the present invention, wherein the webbing retractor is moved toward and away from the energy absorbing member on the other axial end side of the spool from the connecting portion. The energy absorbing member is provided so as to move closer to the energy absorbing member to engage with the energy absorbing member to lock the rotation of the energy absorbing member in the pull-out direction and to the first lock member mechanically. The lock mechanism is configured to include a second lock member that is connected to the energy absorption member and moves the first lock member in the lockable position to the energy absorption member by moving closer to the energy absorption member. It is a feature.

  According to the webbing retractor according to the third aspect of the present invention, when the lock mechanism is activated, the second lock member moves closer to the energy absorbing member. Thus, when the second lock member moves closer to the energy absorbing member, the second lock member is directly or indirectly connected to the energy absorbing member at the other axial end side of the spool from the connecting portion between the spool and the energy absorbing member. Engage. As a result, the rotation of the energy absorbing member in the pull-out direction is locked on the other axial end side of the spool from the connecting portion between the spool and the energy absorbing member.

  On the other hand, as described above, when the second lock member moves closer to the energy absorbing member and engages the energy absorbing member, the first lock member mechanically coupled to the second lock member is interlocked to absorb energy. The second locking member engages with the energy absorbing member directly or indirectly on the other end side in the axial direction of the spool from the connecting portion. As a result, the rotation of the energy absorbing member in the pull-out direction is locked at the other axial end side of the spool than the connecting portion.

  That is, in the webbing take-up device according to the present invention, when the lock mechanism is operated, the energy absorbing member is basically locked at both ends along the axial direction of the spool by the first lock member and the second lock member. Therefore, the first limit load is based on both the rigidity of the energy absorbing member on the one axial end side of the spool from the connecting portion and the rigidity of the energy absorbing member on the other axial end side of the spool from the connecting portion. It becomes.

  Here, as described above, when the predetermined condition is satisfied, the release unit is activated, and when the energy absorption member is unlocked by the first lock member, the torsional deformation of the energy absorption member is performed. This is performed only on one axial end side of the spool from the connecting portion. Therefore, in this state, the energy absorbing member is deformed when a load larger than the second limit load based on the rigidity of the energy absorbing member on the other axial end side of the spool is applied to the connecting portion. Moreover, regarding the second limit load, the rigidity of the energy absorbing member on the other axial end side of the spool from the connecting portion is basically irrelevant. For this reason, the second limit load is smaller than the first limit load.

  Thus, by operating the release means, the first and second limit loads for deforming the energy absorbing member can be selectively switched. In particular, the operation timing of the release means should be set after the lock mechanism is activated. For example, the energy absorbing member can be unlocked during the deformation of the energy absorbing member, or the energy absorbing member can be deformed at the second limit load less than the first limit load.

  A webbing retractor according to a fourth aspect of the present invention is the webbing take-up device according to the third aspect of the present invention, wherein the webbing take-up device according to the third aspect is provided on one end side in the axial direction of the spool with respect to the connecting portion. And the first lock member moved in the lock direction is directly or indirectly engaged with the tip side, and the rotation in the pull-out direction on the tip side is restricted by the first lock member. A rod-shaped first deformable portion, and a dimension along the axial direction of the spool that is longer than the first deformable portion, and is provided on the other axial end side of the spool from the connecting portion, The second locking member that is integrally coupled to the connecting portion at the proximal end portion and that has moved in the locking direction is directly or indirectly engaged with the distal end side, so that the rotation in the pulling direction on the distal end side is performed. A second deforming portion restricted by the second locking member; It was constituting the energy absorbing member including, and characterized in that.

  According to the webbing take-up device of the present invention as set forth in claim 4, the first deformation of the energy absorbing member is engaged with the first locking member moved in the locking direction on the distal end side of the first deformation portion, whereby the first deformation Rotation in the pull-out direction is restricted at the tip side of the part. In addition, when the second locking member moved in the locking direction is engaged with the distal end side of the second deforming portion of the energy absorbing member, the distal end side of the second deforming portion is restricted from rotating in the pull-out direction.

  Therefore, the first limit load in a state where the leading ends of the first deformable portion and the second deformable portion are restricted by the first lock member and the second lock member in this way is the rigidity of the first deformable portion and the second This is based on both the rigidity of the deformed portion.

  However, since the second deforming portion is provided on the side opposite to the first deforming portion via the connecting portion, the webbing belt is forcibly pulled out and the spool rotates in the pulling-out direction. Is transmitted to the connecting portion, the base end side of the first deformable portion and the base end side of the second deformable portion are integrally twisted and deformed in the pull-out direction with respect to the distal end side. The amount of torsional deformation (that is, the rotation angle of both base end portions with respect to the both distal ends of the first deformable portion and the second deformable portion) is the same between the first deformable portion and the second deformable portion.

  Here, since the dimension of the second deforming portion along the axial direction of the spool is longer than that of the first deforming portion, the second deforming portion can be deformed even if the first deforming portion is torsionally deformed until the first deforming portion is broken. The deforming portion continues torsionally deform without breaking, and the second deforming portion is broken by further twisting the second deforming portion from this state.

  As described above, in the webbing take-up device according to the present invention, even if the first deformable portion is broken, the second deformable portion is not broken, so that the rotation restriction of the second deformable portion by the second lock member is continued. Thereby, even after the first deforming portion is broken, it is possible to resist the pulling force that pulls out the webbing belt, so that the occupant's body can be restrained sufficiently and reliably by the webbing belt.

  A webbing take-up device according to a fifth aspect of the present invention is the webbing take-up device according to the third aspect of the present invention, wherein the webbing take-up device is provided closer to one end in the axial direction of the spool than the connecting portion. And the first lock member moved in the lock direction is directly or indirectly engaged with the tip side, and the rotation in the pull-out direction on the tip side is restricted by the first lock member. And the other axial end of the spool than the connecting portion, the first deforming portion being formed in a bar shape having a cross-sectional area cut in a direction perpendicular to the axial direction of the spool. The second locking member that is provided on the side and is integrally coupled to the connecting portion at the base end portion and that is moved in the locking direction directly or indirectly engages the leading end side, and the leading end is pulled out. Rotation in the direction is restricted by the second lock member A second deforming portion to be constituted the said energy absorbing member including, and characterized in that.

  According to the webbing take-up device according to the fifth aspect of the present invention, the first deforming member is engaged with the distal end side of the first deforming portion of the energy absorbing member, whereby the first deforming member is engaged. Rotation in the pull-out direction is restricted at the tip side of the part. In addition, when the second locking member moved in the locking direction is engaged with the distal end side of the second deforming portion of the energy absorbing member, the distal end side of the second deforming portion is restricted from rotating in the pull-out direction.

  Therefore, the first limit load in a state where the leading ends of the first deformable portion and the second deformable portion are restricted by the first lock member and the second lock member in this way is the rigidity of the first deformable portion and the second This is based on both the rigidity of the deformed portion.

  Here, the cross-sectional area when the second deformable portion is cut along the direction orthogonal to the axial direction of the spool is smaller than the cross-sectional area of the first deformable portion when cut in the same manner. Therefore, the rigidity per unit length along the axial direction of the spool is greater in the first deformable portion than in the second deformable portion.

  For this reason, the difference of the magnitude | size of the 1st limit load based on the rigidity of both the 1st deformation part and the 2nd deformation part, and the magnitude | size of the 2nd limit load based only on the rigidity of a 2nd deformation part can be enlarged.

  A webbing take-up device according to a sixth aspect of the present invention is the webbing take-up device according to the third aspect of the present invention, wherein the webbing take-up device is provided closer to one end in the axial direction of the spool than the connecting portion. And the first lock member moved in the lock direction is directly or indirectly engaged with the tip side, and the rotation in the pull-out direction on the tip side is restricted by the first lock member. And a torsional deformation amount required for breaking when the distal end side is twisted and deformed around the axial direction of the spool with respect to the base end portion than the first deformable portion. The second rod is formed in a large rod shape, is provided on the other axial end side of the spool with respect to the connecting portion, is integrally coupled to the connecting portion at a base end portion, and moves in the locking direction. The locking member is directly or indirectly engaged with the tip side, and the tip A second deformation portion which rotates in the pull-out direction side is restricted by the second locking member, constituted the energy absorbing member including, and characterized in that.

  According to the webbing take-up device of the present invention described in claim 6, the first deformation of the energy absorbing member is engaged with the first locking member moved in the locking direction on the tip side of the first deformation portion, so that the first deformation Rotation in the pull-out direction is restricted at the tip side of the part. In addition, when the second locking member moved in the locking direction is engaged with the distal end side of the second deforming portion of the energy absorbing member, the distal end side of the second deforming portion is restricted from rotating in the pull-out direction.

  Therefore, the first limit load in a state where the leading ends of the first deformable portion and the second deformable portion are restricted by the first lock member and the second lock member in this way is the rigidity of the first deformable portion and the second This is based on both the rigidity of the deformed portion.

  However, since the second deforming portion is provided on the side opposite to the first deforming portion via the connecting portion, the webbing belt is forcibly pulled out and the spool rotates in the pulling-out direction. Is transmitted to the connecting portion, the base end side of the first deformable portion and the base end side of the second deformable portion are integrally twisted and deformed in the pull-out direction with respect to the distal end side. The amount of torsional deformation (that is, the rotation angle of both base end portions with respect to the both distal ends of the first deformable portion and the second deformable portion) is the same between the first deformable portion and the second deformable portion.

  Here, the amount of torsional deformation necessary for the second deformable portion to break due to the torsional deformation is greater than the amount of torsional deformation necessary to break the first deformable portion. For this reason, even if the first deformable portion is torsionally deformed until the first deformable portion breaks, the second deformable portion continues torsionally deform without breaking, and the second deformable portion is further twisted from this state. The second deformed portion is broken by being deformed.

  As described above, in the webbing take-up device according to the present invention, even if the first deformable portion is broken, the second deformable portion is not broken, so that the rotation restriction of the second deformable portion by the second lock member is continued. Thereby, even after the first deforming portion is broken, it is possible to resist the pulling force that pulls out the webbing belt, so that the occupant's body can be restrained sufficiently and reliably by the webbing belt.

  A webbing take-up device according to a seventh aspect of the present invention is the webbing take-up device according to any one of the fourth to sixth aspects, wherein the distal end side of the webbing take-up device is at the distal end side with respect to the proximal end portion of the second deformable portion. The amount of torsional deformation required to break when the spool is torsionally deformed around the axial direction of the spool is wound around the spool in a state where the rotation of the second deforming portion is restricted by the second lock member. The webbing belt is set to be larger than the amount of rotation of the spool required to pull out the webbing belt by a predetermined length.

  According to the webbing take-up device of the present invention described in claim 7, when the distal end side is twisted and deformed by a predetermined amount (predetermined angle) around the axial direction of the spool with respect to the proximal end portion of the second deformable portion. The second deformed portion is broken. Here, in the webbing take-up device according to the present invention, the amount of torsional deformation necessary for breaking the second deformable portion is wound around the spool while the second lock member restricts the rotation of the second deformable portion. This is larger than the amount of rotation in the pull-out direction of the spool necessary for pulling out the webbing belt being taken out by a predetermined length.

  For this reason, even if a webbing belt having a length less than a predetermined length is pulled out from the spool, the second deforming portion is not broken, and the occupant's body can be reliably restrained by the webbing belt.

  The “predetermined length” of the webbing belt is not particularly limited. As an example, the second lock member is wound around the spool in a state where the rotation of the second deformable portion is restricted. The total amount of webbing belt is conceivable.

  The webbing take-up device according to the present invention described in claim 8 is the webbing retractor according to any one of claims 1 to 7, wherein the first locking member is configured to perform the operation start timing of the release means. It is set after engaging directly or indirectly with the energy absorbing member.

  According to the webbing retractor of the present invention as set forth in claim 8, when the first lock member is directly or indirectly engaged with the energy absorbing member in a state where the predetermined condition is satisfied, The release means operates after the lock member is engaged, and the support of the first lock member by the support means is forcibly released.

  That is, in the webbing take-up device according to the present invention, at least immediately after the start of the operation of the lock mechanism, the rotation of the energy absorbing member in the pull-out direction is controlled by the first lock member, and then the rotation by the first lock member is performed. Regulations are lifted. Therefore, the deformation of the energy absorbing member can be stopped halfway, or can be switched to the deformation of the energy absorbing member at the second limit load described above.

  A webbing take-up device according to a ninth aspect of the present invention is the webbing take-up device according to the first aspect of the present invention according to any one of the first to eighth aspects, wherein the first support member is attached to the first support member from below the first lock member. The lock member is supported, and the support balance for supporting the first lock member is broken by releasing the support of the first lock member by the support means, or the first lock is released by releasing the support by the support means. The first lock member is dropped downward by the weight of the member and separated from the lockable position.

  According to the webbing take-up device according to the ninth aspect of the present invention, at least the first lock member is supported by the support means from below at the lockable position. When the release means is actuated to forcibly displace the support means, the first lock member loses support from below by the support means, and thereby the support balance for supporting the first lock member is lost and the first lock member is lost. If one lock member falls or the first lock member is supported only by the support means, the first lock member simply falls by its own weight. Thus, the 1st lock member leaves | separates from a lockable position because the 1st lock member falls.

  As described above, in the webbing take-up device according to the present invention, when the support of the first lock member by the support means is released, the support balance for supporting the first lock member is broken, or the first lock member Since the first lock member is released from the lockable position by dropping due to its own weight, only the support means needs to be forcibly displaced when the first lock member is released from the lockable position, and an external force is applied to the first lock member. The structure which forcibly displaces the 1st lock member by providing is unnecessary. Thereby, the configuration of the apparatus can be simplified, and the apparatus can be downsized, the number of parts can be reduced, and the cost can be reduced.

  As described above, the webbing take-up device according to the present invention can be provided with a mechanism capable of forcibly releasing the engagement between the spool and the lock member without increasing the size of the spool.

<Configuration of First Embodiment>
FIG. 1 is a front sectional view showing an outline of the entire configuration of a webbing take-up device 10 according to a first embodiment of the present invention.

  As shown in this figure, the webbing take-up device 10 includes a frame 12. The frame 12 includes a substantially plate-like back plate 14. The back plate 14 is fixed to the vehicle body by fastening means (not shown) such as bolts, so that the webbing take-up device 10 is attached to the vehicle body. ing. A pair of leg plates 16 and 18 extend in parallel from both ends of the back plate 14 in the width direction, and a spool 20 as a winding shaft manufactured by die casting or the like is rotatable between the leg plates 16 and 18. Has been placed.

  The spool 20 includes a substantially cylindrical spool body 22 and a pair of flange portions 24 and 26 formed in a substantially disk shape at both ends of the spool body 22, respectively. Yes.

  Between the flange portions 24 and 26 of the spool body 22, a base end portion of a webbing belt 28 formed in a long band shape is locked, and when the spool 20 is rotated in one winding direction around its axis, The webbing belt 28 is wound around the outer periphery of the spool body 22 in a layered manner from the base end side. When the webbing belt 28 is pulled from the front end side, the webbing belt 28 wound around the outer periphery of the spool body 22 is pulled out, and the spool 20 rotates in a pulling direction opposite to the winding direction. .

  A torsion shaft 30 as an energy absorbing member is disposed inside the spool 20. The torsion shaft 30 includes a connecting portion 32. The connecting portion 32 is provided closer to the leg plate 16 than the axially central portion inside the spool 20. Further, the connecting portion 32 is generally formed in a substantially polygonal column shape or a substantially cylindrical shape having a knurl or the like formed on the outer peripheral portion, and the shaft center line substantially coincides with the shaft center line of the spool 20. 20 is integrally connected to the inner periphery.

  A first deforming portion 34 is provided at one end portion in the axial direction of the connecting portion 32 (the end portion on the leg plate 18 side). The first deformable portion 34 has a substantially coaxial cylindrical shape with respect to the connecting portion 32, and is integrally connected to the connecting portion 32 at an end portion on the connecting portion 32 side.

  On the other hand, a second deforming portion 36 is provided at the other axial end portion (the end portion on the leg plate 16 side) of the connecting portion 32. The second deforming portion 36 is substantially coaxial with the connecting portion 32 and has a larger diameter than the first deforming portion 34, and is integrally formed with the connecting portion 32 at the end on the connecting portion 32 side. It is connected.

  The end of the second deformable portion 36 opposite to the connecting portion 32 passes through a circular hole 38 formed in the leg plate 16 and protrudes outside the frame 12. A ratchet wheel 40 in which outer ratchet teeth are formed on the outer peripheral portion is coaxially and integrally formed at the distal end of the second deformable portion 36 protruding from the leg plate 16. An engaging shaft 42 is formed coaxially and integrally with the ratchet wheel 40 on the side opposite to the deformable portion 36.

  A spring case 44 is disposed on the side of the ratchet wheel 40 opposite to the leg plate 16. The spring case 44 is integrally connected to the leg plate 16 or the back plate 14 directly or indirectly, and a spiral spring 46 is accommodated inside thereof.

  The end of the spiral spring 46 on the outer side in the spiral direction is integrally connected to the spring case 44, and the end on the inner side in the spiral direction is connected to the engagement shaft 42 that has entered the spring case 44. Has been. The spiral spring 46 is tightened when the engagement shaft 42 rotates in the pull-out direction, and increases the urging force in the winding direction with respect to the engagement shaft 42.

  On the other hand, the end of the torsion shaft 30 opposite to the connecting portion 32 of the first deformable portion 34 passes through a circular hole 48 formed in the leg plate 18 and protrudes outside the frame 12. A ratchet wheel 50 in which outer ratchet teeth are formed on the outer peripheral portion is coaxially and integrally formed at the tip of the first deformable portion 34 protruding from the leg plate 18.

  In addition, a housing 54 of the lock mechanism 52 is disposed on the opposite side of the ratchet wheel 50 from the first deformation portion 34. The housing 54 is integrally connected to the leg plate 18 or the back plate 14 directly or indirectly.

  On the inner side of the housing 54, a rotating body provided coaxially and integrally with the ratchet wheel 50, an inertial plate as an inertial mass body provided coaxially and rotatable relative to the rotating body, rotation The body and the inertia plate are coupled, and the inertia plate is pressed in the rotation direction of the rotating body with a spring force (biasing force) increased according to the relative rotation amount of the rotating body with respect to the inertia plate generated by the rotation of the rotating body. Each member such as a spring that rotates the inertial plate following the rotating body, an acceleration sensor that engages with the inertial plate by rolling of an inertial hard ball and restricts the rotation of the inertial plate is accommodated.

  Further, a lock pawl 56 as a second lock member is disposed between the housing 54 and the leg plate 18. The lock pawl 56 includes a shaft 58 whose axial direction is parallel to the axial direction of the spool 20. The shaft 58 is rotatably supported by the leg plate 18 and has a structure that comes into contact with and separates from the outer periphery of the ratchet wheel 50 by turning around the shaft 58.

  Further, a part of the lock pawl 56 enters the inside of the housing 54, engages with both the rotating body and the inertia plate in the housing 54, and interlocks with the relative rotation of the rotating body in the pulling direction with respect to the inertia plate. The lock pawl 56 is configured to move closer to the outer periphery of the ratchet wheel 50. Furthermore, external ratchet teeth are formed on a part of the outer periphery of the lock pawl 56, and when the lock pawl 56 moves closer to the outer periphery of the ratchet wheel 50, the ratchet teeth of the lock pawl 56 become the ratchet teeth of the ratchet wheel 50. The lock pawl 56 regulates the rotation of the ratchet wheel 50 in the pull-out direction.

  On the other hand, a shaft 60 having an axial direction parallel to the axial direction of the spool 20 is integrally connected to the shaft 58. A shaft 62 is formed coaxially with the shaft 58 at the end of the shaft 60 opposite to the shaft 58, and is rotatably supported by the leg plate 16. A swing arm 64 disposed outside the leg plate 16 is fixed to the tip of the shaft 62, and rotates together with the shaft 62 around the axis of the shaft 62.

  As shown in FIGS. 1 and 2, a cam plate 66 as a support means is provided on the opposite side of the leg plate 16 via the swing arm 64. As shown in FIGS. 2 and 3, the cam plate 66 is supported by the leg plate 16 so that its main body portion 68 is rotatable about an axis parallel to the spool 20.

  An upper portion of the main body portion 68 is a support portion 70. A lock pawl 72 as a first lock member is provided on the upper surface of the tip of the support portion 70 and below the ratchet wheel 40 described above. The lock pawl 72 is supported from below by a support portion 70 (cam plate 66).

  Further, a guide pin 74 is formed on the lock pawl 56 at a position displaced from the support position of the lock pawl 72 by the support portion 70 (in FIG. 3, the upper left of the support position of the lock pawl 72).

  The guide pin 74 enters the elongated hole 76 formed in the swing arm 64 described above. As a result, the swing arm 64 and the lock pawl 56 are mechanically coupled, and the lock pawl 56 rotates around the support position of the support portion 70 in conjunction with the swing of the swing arm 64 around the shaft 62. Move. The lock pawl 56 contacts and separates from the outer peripheral portion of the ratchet wheel 40 by this rotation.

  External ratchet teeth are formed on a part of the outer periphery of the lock pawl 72. When the lock pawl 72 moves closer to the outer periphery of the ratchet wheel 40, the ratchet teeth of the lock pawl 72 mesh with the ratchet teeth of the ratchet wheel 40. The lock pawl 72 restricts the rotation of the ratchet wheel 40 in the pull-out direction.

  Further, an interference piece 73 is formed on the leg plate 16 corresponding to the lock pawl 72 located at the meshing position (lock position) where the ratchet teeth of the lock pawl 72 mesh with the ratchet teeth of the ratchet wheel 40. The interference piece 73 interferes with the lock pawl 72 located at the meshing position from the back plate 14 side. The lock pawl 72 that has reached the meshing position is configured to be held at the meshing position by balancing the interference from the interference piece 73 and the support from the support portion 70 (cam plate 66).

  As described above, the swing arm 64 that rotates the lock pawl 72 is connected to the lock pawl 56 via the shafts 62, 60, and 58, and the lock pawl 72 approaches the outer periphery of the ratchet wheel 40. The swing direction of the swing arm 64 is the same as the rotation direction when the lock pawl 56 approaches the outer peripheral portion of the ratchet wheel 50.

  On the other hand, a contact piece 78 is formed below the main body portion 68 of the cam plate 66 described above. Further, a cylinder 80 constituting a releasing means is disposed on the side of the contact piece 78. A cylinder 82 is slidably provided with a piston 82 that constitutes a releasing means together with the cylinder 80 along the axial direction thereof. The abutting piece 78 is generally located on the side of the tip of the piston 82 along the axial direction of the cylinder 80 and the rotational tangent direction of the cam plate 66 in the abutting piece 78, and the piston protruding from the cylinder 80. The cam plate 66 can be rotated by the 82 abutting against the abutting piece 78 and pressing the abutting piece 78.

  Inside the cylinder 80, a gunpowder and an ignition device that ignites the gunpowder are housed, and the piston 82 is pushed out of the cylinder 80 by a sudden increase in gas pressure caused by burning the gunpowder.

  The ignition device accommodated in the cylinder 80 is electrically connected to the control device 84, and the ignition device ignites the explosive based on the electrical ignition signal output from the control device 84.

<Operation and Effect of First Embodiment>
Next, the operation and effect of the present embodiment will be described through the operation of the webbing take-up device 10.

  In the webbing take-up device 10, when the webbing belt 28 is pulled while pulling a tongue plate (not shown) with the webbing belt 28 wound in layers on the spool 20, a spiral that urges the spool 20 in the winding direction. The webbing belt 28 is pulled out while rotating the spool 20 in the pulling direction against the urging force of the spring 46. In this way, with the webbing belt 28 pulled out, the tongue plate is inserted into a buckle device (not shown) while the webbing belt 28 is hung around the front of the occupant seated on the seat, and the tongue plate is held by the buckle device. Thus, the webbing belt 28 is attached to the occupant's body (hereinafter, simply referred to as “attached state”).

  Further, when the webbing belt 28 is pulled out and the spool 20 is rotated in the pulling-out direction in order to mount the webbing belt 28, the spiral spring 46 is tightened and the spool 20 is biased toward the winding direction. Power increases. Therefore, in the mounted state, the urging force of the spiral spring 46 acts so as to wind the webbing belt 28 around the spool 20, so that the urging force basically fits the webbing belt 28 to the occupant's body, The webbing belt 28 restrains and holds the occupant's body with a force corresponding to the urging force at this time.

  On the other hand, when the tongue plate is released from the buckle device and the tongue plate comes out of the buckle device, the force for maintaining the webbing belt 28 in the pulled-out state against the urging force of the spiral spring 46 is released. Therefore, the spiral spring 46 rotates the spool 20 in the winding direction with an urging force. The webbing belt 28 drawn out by the rotation of the spool 20 in the winding direction is wound around the outer periphery of the spool 20 in a layered manner, whereby the webbing belt 28 is stored.

  On the other hand, when the vehicle suddenly decelerates, the inertia steel balls constituting the acceleration sensor of the lock mechanism 52 described above roll due to inertia. As the inertia steel ball rolls, the acceleration sensor engages with the inertia plate, locks the inertia plate, and restricts the rotation of the inertia plate in the pull-out direction.

  On the other hand, when the vehicle suddenly decelerates as described above, the body of the vehicle occupant tends to move substantially forward of the vehicle due to inertia. When the occupant's body is about to move to the front side of the vehicle, the webbing belt 28 attached to the occupant's body is pulled, thereby causing the spool 20 to rotate in the pull-out direction. The rotational force in the pull-out direction is transmitted to the rotating body in the housing 54 via the connecting portion 32, the second deforming portion 36, and the ratchet wheel 50, and the rotating body tries to rotate in the pull-out direction.

  Here, as described above, in this state, since the rotation of the inertia plate is regulated by the acceleration sensor, the rotation of the inertia plate and the inertia plate is resisted against the urging force of the spring connecting the inertia plate and the rotating body. Relative rotation occurs with the body, and the rotating body rotates in the pull-out direction with respect to the inertia plate. The lock pawl 56 rotates around the shaft 58 and moves closer to the ratchet wheel 50 in conjunction with the relative rotation generated between the rotating body and the inertia plate.

  Thus, when the lock pawl 56 moves closer to the ratchet wheel 50, the ratchet teeth of the lock pawl 56 mesh with the ratchet teeth of the ratchet wheel 50, and the ratchet wheel 50 is locked. As a result, the rotation of the ratchet wheel 50 in the pull-out direction is restricted. As a result, the rotation of the spool 20 integrally connected to the ratchet wheel 50 via the second deforming portion 36 and the connecting portion 32 is prevented from rotating in the pull-out direction. Be regulated.

  As described above, when the lock pawl 56 rotates and approaches the ratchet wheel 50, the rock pawl 56 is connected to the lock pawl 56 via the shafts 58 to 62 in conjunction with the rotation of the lock pawl 56. The arm 64 swings. Further, when the swing arm 64 swings, the lock pawl 72 connected to the swing arm 64 is rotated by the guide pin 74 that has entered the elongated hole 76.

  Since the rotation direction of the lock pawl 72 at this time is a direction approaching the ratchet wheel 40, the lock pawl 72 has been rotated away from the ratchet wheel 40 until then as shown in FIG. 3. As shown in FIG. 4, the lock pawl 72 has the ratchet teeth of the lock pawl 72 meshing with the ratchet teeth of the ratchet wheel 40. As a result, the ratchet wheel 40 is locked and the rotation of the ratchet wheel 40 in the pull-out direction is restricted.

  Similarly to the ratchet wheel 50, the ratchet wheel 40 is also connected to the spool 20 via the first deforming portion 34 and the connecting portion 32. Therefore, the rotation of the ratchet wheel 40 in the pull-out direction is restricted so that the ratchet wheel 40 moves in the pull-out direction. The rotation of the spool 20 is restricted.

  As described above, when the lock pawls 72 and 56 are engaged with the ratchet wheels 40 and 50 and the rotation of the spool 20 in the pull-out direction is restricted, the amount of the webbing belt 28 wound around the spool 20 is basically limited. Will not be withdrawn. In this way, the body of the vehicle occupant is reliably restrained by the webbing belt 28 whose withdrawal is restricted, and movement of the occupant's body toward the front side of the vehicle is restricted.

  On the other hand, as described above, even when the rotation of the spool 20 in the pull-out direction is restricted, the occupant's body pulls the webbing belt 28 due to inertia in the vehicle sudden deceleration state. This pulling force becomes a rotational force in the pulling direction of the spool 20, and this rotational force is applied to the first deformable portion 34 and the second deformable portion 36 via the connecting portion 32.

  Here, when the tensile force at this time becomes equal to or greater than the first limit load (first force limiter load) based on the rigidity of both the first deformation portion 34 and the second deformation portion 36, the first deformation portion 34 is rotated. The end portion on the connecting portion 32 side rotates in the pull-out direction relative to the end portion on the ratchet wheel 50 side, and is torsionally deformed. Further, the second deforming portion 36 is also twisted and deformed by rotating the end portion on the connecting portion 32 side in the drawing direction relative to the end portion on the ratchet wheel 40 side that is restricted in rotation.

  Further, as described above, both the first deformable portion 34 and the second deformable portion 36 are rotated in the pull-out direction by the torsional deformation, and the spool 20 is rotated in the pull-out direction. When the spool 20 rotates in the pull-out direction by a rotation amount corresponding to the torsional deformation of both the first deformation portion 34 and the second deformation portion 36, the webbing belt 28 is pulled out by a length corresponding to this rotation amount. It is.

  Thereby, the restraining force of the webbing belt 28 on the occupant's body is relaxed. In addition, since the energy of the tensile force is absorbed by the torsional deformation of both the first deformable portion 34 and the second deformable portion 36, the webbing belt 28 is not pulled out suddenly even in such a case.

  Further, as described above, after a very short predetermined time has elapsed since the start of the torsional deformation of both the first deformation portion 34 and the second deformation portion 36, an ignition signal is output from the control device 84, The ignition device in the cylinder 80 operates. When the ignition device is actuated, the explosive in the cylinder 80 is burned, whereby the internal pressure in the cylinder 80 rapidly increases. The piston 82 is pushed out by the sudden increase in internal pressure in the cylinder 80. When the piston 82 is pushed out, as shown in FIG. 5, the tip of the piston 82 collides with the contact piece 78 of the cam plate 66, and the cam plate 66 is forcibly rotated as shown in FIG. .

  By the rotation of the cam plate 66, the support portion 70 of the cam plate 66 is displaced from the support position of the lock pawl 72. The lock pawl 72 loses the support by the support part 70 when the support part 70 is displaced from the support position, and is only supported based on the interference from the interference piece 73. As described above, since the support of the lock pawl 72 is only the interference from the interference piece 73, the support balance (support balance) for supporting the lock pawl 72 is broken.

  In this way, when the support balance of the lock pawl 72 is broken, the lock pawl 72 rotates around the guide pin 74 that has entered the long hole 76, and accordingly, the ratchet teeth of the lock pawl 72 are ratchet of the ratchet wheel 40. It rotates while being separated from the teeth, and moves to a position where it cannot mesh with the ratchet teeth of the ratchet wheel 40.

  In this way, the engagement between the ratchet wheel 40 and the lock pawl 72 is canceled, and thus the rotation restriction of the ratchet wheel 40 in the pull-out direction is released. Thereby, the opposite side to the connection part 32 of the 1st deformation | transformation part 34 will be in the state which can rotate freely freely. Therefore, in this state, even if a rotational force in the pulling direction of the spool 20 is applied to the first deforming portion 34 via the connecting portion 32, the first deforming portion 34 rotates in the pulling direction together with the connecting portion 32. Doing so does not cause torsional deformation.

  For this reason, in this state, if the tensile force applied to the webbing belt 28 is equal to or greater than the second limit load (second force limiter load) based on the rigidity of the second deformable portion 36, the second deformable portion 36 rotates. The end portion on the connecting portion 32 side rotates in the pull-out direction relative to the end portion on the ratchet wheel 40 side that is regulated, and is torsionally deformed.

  Here, the first limit load (first force limiter load) was based on the rigidity of both the first deformable portion 34 and the second deformable portion 36, whereas the second limit load (second force limiter load) was Based on the rigidity of the second deformation part 36, the rigidity of the first deformation part 34 is basically irrelevant. For this reason, the second limit load is smaller than the first limit load. Therefore, if the pulling force of the same magnitude is applied, the spool 20 is pulled out when the lock pawl 72 is engaged with the ratchet wheel 40. The webbing belt 28 can be pulled out more than the webbing belt 28.

  Thus, for example, if the vehicle equipped with the webbing take-up device 10 is a vehicle equipped with a so-called airbag device, the webbing belt 28 is relatively strong until the airbag is reliably deployed in front of the occupant. The passenger's body can be restrained, and immediately after the airbag is deployed, the restraining force by the webbing belt 28 is weakened so that the passenger's body can be received by the deployed airbag.

  As described above, in the present webbing take-up device 10, after the lock pawls 56 and 72 are engaged with the ratchet wheels 50 and 40, the engagement between the one lock pawl 72 and the ratchet wheel 40 is released, and the torsion shaft 30. The limit load based on the force (force limiter load) can be reduced.

  In addition, since the lock pawl 72, the cam plate 66, the swing arm 64, and the shafts 60 and 62 are disposed outside the spool 20, the spool 20 can be reduced in size, and consequently the overall webbing take-up device 10 can be reduced in size. Can be realized.

  Further, when a structure corresponding to the lock pawl 72 or the like as described above is housed in the spool 20, the spool 20 is a webbing take-up device having a mechanism for forcibly releasing the engagement between the lock pawl 72 and the ratchet wheel 40. It becomes a dedicated part. On the other hand, in the present embodiment, a mechanism for forcibly releasing the engagement between the lock pawl 72 and the ratchet wheel 40 is provided outside the spool 20, so that the webbing take-up device that does not have such a forcible release mechanism is provided. In contrast, the spool 20 can be diverted.

  That is, even when the mechanism for forcibly releasing the engagement between the lock pawl 72 and the ratchet wheel 40 as described above is a so-called option, the spool 20 can be used as a common part regardless of the presence or absence of the forcible release mechanism. Cost can be reduced.

  In this embodiment, when releasing the engagement between the lock pawl 72 and the ratchet wheel 40, the cam plate 66 is forcibly rotated to balance the lock pawl 72 by the cam plate 66 and the interference piece 73. By breaking, the lock pawl 72 is rotated and dropped.

  As described above, a structure for forcibly rotating the lock pawl 72 by losing the support balance between the cam plate 66 and the interference piece 73 (for example, a motor or the like). Driving means) becomes unnecessary. Thereby, the cost can be reduced and the structure can be simplified.

  In the present embodiment, as described above, the lock pawl 72 is supported by the cam plate 66 and the interference piece 73, and the support by the cam plate 66 is lost, so that the support balance of the lock pawl 72 is forced. The lock pawl 72 was rotated by breaking. However, unlike the present embodiment, the lock pawl 72 need not be supported by interfering from a plurality of directions. For example, the lock pawl 72 is supported only from below by the cam plate 66, and the cam plate 66 is forcibly supported. The lock pawl 72 may be rotated by its own weight so that the lock pawl 72 is dropped by releasing the support from the lower side of the lock pawl 72 by the cam plate 66.

  In the present embodiment, after the two lock pawls 56 and 72 are engaged with the two ratchet wheels 50 and 40, the engagement between the one lock pawl 72 and the ratchet wheel 40 is released. It is good also as a structure which cancels | releases mesh | engagement of one lock pawl 72 and the ratchet wheel 40, before 56 and 72 mesh with both ratchet wheels 50 and 40. Even in this case, there is no change in the mechanical structure, and this can be easily realized by changing the output timing of the ignition control signal output from the control device 84.

  Further, in the present embodiment, as described above, the present invention is applied to the structure in which the torsion shaft 30 is locked at both axial ends of the spool 20. However, it is also possible to apply the present invention to a structure in which the torsion shaft 30 is locked only at one axial end side of the spool 20. In such a case, the webbing belt 28 can be simply pulled out by forcibly releasing the engagement between the lock pawl and the ratchet wheel.

  Here, when a member such as a lock plate is relatively firmly engaged with the ratchet wheel, even if the relative rotation between the rotating body and the inertia plate in the lock mechanism is canceled, the engagement between the ratchet wheel and the lock plate is prevented. It may not be resolved. When the present invention is applied to such a configuration, it is possible to obtain an effect of forcibly canceling the rotation restriction in the pull-out direction of the ratchet wheel regardless of the relative rotation between the rotating body and the inertia plate in the lock mechanism.

  Furthermore, in the present embodiment, the cylinder 80 and the piston 82 are applied to the release means, but the configuration of the release means is not limited to the cylinder 80 and the piston 82. For example, the release means may be a solenoid that displaces a shaft that includes a magnetic material by a magnetic field formed by energization.

<Configuration of Second Embodiment>
Next, a second embodiment of the present invention will be described. In the description of the present embodiment, the same reference numerals are assigned to the same parts as those in the first embodiment, and the detailed description thereof is omitted.

  FIG. 7 is a front sectional view schematically showing the overall configuration of the webbing take-up device 90 according to the present embodiment.

  As shown in this figure, the webbing take-up device 90 is basically the same in configuration as the webbing take-up device 10 according to the first embodiment. However, the webbing take-up device 90 does not include the torsion shaft 30, but instead includes a torsion shaft 92 as an energy absorbing member. The torsion shaft 92 includes a connecting portion 32 as with the torsion shaft 30, and a first deforming portion 34 is provided at one axial end of the connecting portion 32 (the end on the leg plate 18 side).

  However, in the webbing take-up device 90, a second deforming portion 94 is provided in place of the second deforming portion 36 at the other axial end portion (the end portion on the leg plate 16 side) of the connecting portion 32. The second deformable portion 94 is provided substantially coaxially with respect to the connecting portion 32, and is connected to the connecting portion 32 integrally at the end on the connecting portion 32 side in the first embodiment. 2 The same as the deforming portion 36.

  However, unlike the second deformation portion 36, the second deformation portion 94 is smaller in diameter than the first deformation portion 34. For example, the outer diameter size of the second deformation portion 94 is approximately 1 / out of the outer diameter size of the first deformation portion 34. It is supposed to be about 2. However, the axial dimension of the second deformable portion 94 is sufficiently longer than the axial dimension of the first deformable portion 34.

  As described in the first embodiment, the ratchet teeth of the lock pawl 56 are the ratchet teeth of the ratchet wheel 50 in the state in which the webbing belt 28 having a predetermined length is wound around the spool 20. When the rotation of the second deformation portion 94 is restricted by meshing with the webbing, the webbing belt 28 having the predetermined length is forcibly pulled out from the spool 20 and the second deformation portion 94 is twisted and deformed. In addition, the second limit load (second force limiter load), that is, the rigidity of the second deformable portion 94 is set so that the second deformable portion 94 does not break.

  It should be noted that the predetermined length of the webbing belt 28 that serves as a guide for setting the second limit load is not particularly limited. However, as an example of the setting, for example, the length of the webbing belt 28 that remains wound around the spool 20 when the webbing belt 28 is worn in a state where a statistical standard human body is seated on the seat. It is possible to do. The length in this case is 90 cm or more and less than 120 cm, for example.

  On the other hand, the rigidity of the first deformable portion 34 is such that the lock pawl 72 is engaged with the ratchet wheel 40 and the vehicle normally collides with a front obstacle while the first deformable portion 34 is locked. In addition, even if the webbing belt 28 is pulled out and the first deformable portion 34 is torsionally deformed via the spool 20, the first deformable portion 34 is set so as not to break.

  Regarding the above-mentioned normal collision, the magnitude of the impact at the time of the collision is not particularly limited, and may be appropriately set based on the specifications of the vehicle. As an example, the vehicle travels at a speed of 56 km / h. It is conceivable to set an impact when a running vehicle collides with an obstacle stopped in front. In this case, the outer diameter of the first deformable portion 34 is 6 mm or more and less than 10 mm.

<Operation and Effect of Second Embodiment>
The basic operation of the webbing take-up device 90 configured as described above is the same as that of the webbing take-up device 10 according to the first embodiment. Here, since the first deformable portion 34 and the second deformable portion 94 are different in rigidity, as shown in FIGS. 8A and 8B, the respective limit loads are different and the second deformable portion 94 is different. The first deformable portion 34 having a larger outer diameter than the second deformable portion 94 becomes F2 larger than the limit load F1 of the second deformable portion 94.

  Accordingly, the ratchet teeth of the lock pawl 56 mesh with the ratchet teeth of the ratchet wheel 50 to restrict the rotation of the second deformation portion 94, and the ratchet teeth of the lock pawl 72 mesh with the ratchet teeth of the ratchet wheel 40 to perform the first deformation. In the state where the rotation of the portion 34 is restricted, as shown in FIG. 8C, the limit load of the torsion shaft 92 becomes a magnitude obtained by superimposing the load F1 on the load F2.

  Furthermore, the body of a vehicle occupant who is about to move forward in the forward direction of the vehicle with greater inertia than that during the normal collision in the rotation restricted state of the first deformation portion 34 and the second deformation portion 94 is worn. When the webbing belt 28 is pulled and the pulling amount (drawing stroke) of the webbing belt 28 by this pulling reaches S1, the torsion shaft 92 is twisted to cause the first deforming portion 34 to break. On the other hand, if the pulling-out amount (drawing stroke) due to the webbing belt 28 wound around the spool 20 in this state being pulled as described above does not reach the predetermined length S2, the second deformation is performed. The portion 94 is not broken.

  Here, in the structure disclosed in US Pat. No. 5,799,893 and US Pat. No. 6,012,667, the outer diameter and axial dimensions of the configuration corresponding to the first deforming portion 34 of the webbing take-up device 90, and the webbing take-up device 90 The outer diameter dimension and the axial dimension of the configuration corresponding to the second deformable portion 94 are substantially equal. Therefore, basically, if one breaks, the other breaks at almost the same time or at an extremely short interval in time (that is, in accordance with FIG. When both reach, both break.)

  Thus, when both are broken, the lock of the spool 20 by the configuration corresponding to the lock pawls 56 and 72 is released, and further, the urging force from the configuration corresponding to the spiral spring 46 is not applied. That is, in this state, the force resisting the pulling force that pulls out the webbing belt 28 is interrupted. For this reason, the body of the vehicle occupant cannot be restrained by the webbing belt 28.

  In contrast, in the present webbing take-up device 90, when the lock pawls 56 and 72 are engaged with the ratchet wheels 50 and 40 as described above, the amount of withdrawal of the webbing belt 28 from the vehicle sudden deceleration state is predetermined. Even if the length S1 is reached, the second deformation portion 94 will not break even if the first deformation portion 34 breaks unless the pull-out amount of the webbing belt 28 reaches S2 that is sufficiently longer than S1. For this reason, even if the vehicle suddenly decelerates at a deceleration greater than that at the time of a normal collision, the occupant's body is reliably restrained by the webbing belt 28 until the pulled-out amount of the webbing belt 28 reaches a predetermined length S1. it can.

  The webbing take-up device 90 has basically the same configuration as the webbing take-up device 10 according to the first embodiment except for the torsion shaft 92. Therefore, naturally, the same effect as the webbing take-up device 10 can be obtained, and the same effect can be obtained.

1 is a front view showing a schematic configuration of an entire webbing take-up device according to a first embodiment of the present invention. It is a disassembled perspective view which shows the structure of the principal part of the webbing take-up device according to the first embodiment of the present invention. It is a side view which shows the state before engagement of a 1st lock member. It is a side view corresponding to Drawing 3 showing the engagement state of the 1st lock member. It is a side view corresponding to FIG. 3 which shows the state which the cancellation | release means act | operated. It is a side view corresponding to FIG. 3 which shows the state by which the support of the 1st lock member by the support means was cancelled | released. It is a front view which shows the schematic structure of the whole webbing winding apparatus which concerns on the 2nd Embodiment of this invention. (A) shows the outline of the relationship between the pulling amount of the webbing belt and the load acting on the second deformation portion, and (B) shows the outline of the relationship between the pulling amount of the webbing belt and the load acting on the second deformation portion. (C) shows the outline of the relationship between the pull-out amount of the webbing belt and the load acting on the entire torsion shaft (energy absorbing member).

Explanation of symbols

10 Webbing take-up device 20 Spool 28 Webbing belt 30 Torsion shaft (energy absorbing member)
32 connecting portion 34 first deforming portion 36 second deforming portion 52 locking mechanism 56 lock pawl (second locking member)
66 Cam plate (support means)
72 Lock pawl (first lock member)
80 cylinders (release means)
82 Piston (Release means)
90 Webbing take-up device 92 Torsion shaft (energy absorbing member)
94 Second deformation part

Claims (9)

A substantially cylindrical spool that is locked on the base end side of the long belt-shaped webbing belt, and that winds the webbing belt from the base end side by rotation in the winding direction that is one of the directions around the axis;
The spool is provided so as to be movable in the locking direction at a lockable position outside the spool on one end side in the axial direction of the spool, and the spool is locked by being directly or indirectly engaged with the spool by the movement in the locking direction. A first lock member that restricts rotation of the spool in the pull-out direction opposite to the winding direction, and that detects a predetermined state of the vehicle and moves the first lock member in the lock direction Mechanism,
Supporting means for supporting the first lock member at the lockable position and releasing the support from the lockable position to a position where the engagement with the spool is impossible by releasing the support; ,
Release means for forcibly displacing the support means when a predetermined condition is satisfied, and forcibly releasing the support state of the first lock member by the support means;
A webbing take-up device comprising: It is provided inside the spool that is formed in a hollow, substantially cylindrical shape that penetrates along the axial direction, and is integrated with the spool at a connecting portion that is formed at the intermediate portion or the other end side along the axial direction. And an energy absorbing member that absorbs energy by deformation around the axis,
Due to the movement in the locking direction, the first locking member is directly or indirectly engaged with the energy absorbing member on one end side in the axial direction with respect to the connecting portion to rotate the energy absorbing member in the pulling direction. regulate,
The webbing take-up device according to claim 1. It is provided so as to be able to move toward and away from the energy absorbing member on the other axial end side of the spool from the connecting portion, and engages with the energy absorbing member by moving closer to the energy absorbing member. Locking the rotation of the energy absorbing member in the pull-out direction, mechanically connected to the first locking member, and moving closer to the energy absorbing member to move the first locking member in the lockable position. The lock mechanism is configured including a second lock member that moves closer to the energy absorbing member.
The webbing take-up device according to claim 2. The first locking member is provided at one end in the axial direction of the spool with respect to the connecting portion, and is integrally coupled to the connecting portion at the base end portion. A rod-shaped first deforming portion that is indirectly engaged and rotation in the pull-out direction on the distal end side is restricted by the first lock member;
The spool has a dimension along the axial direction of the spool that is longer than the first deformable portion, and is provided on the other axial end side of the spool with respect to the connecting portion. The second locking member that is integrally coupled and moved in the locking direction is directly or indirectly engaged with the distal end side, and rotation in the pulling direction on the distal end side is restricted by the second locking member. A second deformation part;
Comprising the energy absorbing member including
The webbing take-up device according to claim 3. The first locking member is provided at one end in the axial direction of the spool with respect to the connecting portion, and is integrally coupled to the connecting portion at the base end portion. A first deforming portion that indirectly engages and is restricted by the first lock member from rotating in the pull-out direction on the distal end side;
A cross-sectional area cut in a direction orthogonal to the axial direction of the spool is formed in a rod shape smaller than the first deforming portion, and is provided on the other axial end side of the spool from the connecting portion, And the second locking member moved in the locking direction is directly or indirectly engaged with the leading end side, and the rotation in the leading side pulling direction is the first 2nd deformation part controlled by 2 lock members,
Comprising the energy absorbing member including
The webbing take-up device according to claim 3. The first locking member is provided at one end in the axial direction of the spool with respect to the connecting portion, and is integrally coupled to the connecting portion at the base end portion. A rod-shaped first deforming portion that is indirectly engaged and rotation in the pull-out direction on the distal end side is restricted by the first lock member;
The torsional deformation required until the distal end side is torsionally deformed around the axial direction of the spool relative to the base end portion is formed in a rod shape larger than that of the first deformable portion, and the connection The second locking member is provided on the other axial end side of the spool with respect to the portion and is integrally coupled to the connecting portion at the base end portion, and the second locking member moved in the locking direction is directly or indirectly on the distal end side. A second deforming portion that is engaged with each other and rotation in the pull-out direction on the distal end side is restricted by the second lock member;
Comprising the energy absorbing member including
The webbing take-up device according to claim 3. When the distal end side is twisted and deformed around the axial direction of the spool with respect to the proximal end portion of the second deformable portion, the second lock member has a second amount of torsional deformation required for breaking. Set larger than the amount of rotation of the spool required to pull out the webbing belt wound around the spool in a state in which the rotation of the deforming portion is regulated,
The webbing take-up device according to any one of claims 4 to 6, wherein The operation start timing of the release means is set after the first lock member is directly or indirectly engaged with the energy absorbing member,
The webbing retractor according to any one of claims 1 to 7, wherein the webbing take-up device is any one of the above. The support means supports the first lock member from below the first lock member, and the support balance for supporting the first lock member is broken by releasing the support of the first lock member by the support means, Alternatively, by releasing the support by the support means, the first lock member is dropped downward by its own weight and is released from the lockable position.
The webbing take-up device according to any one of claims 1 to 8, wherein the webbing take-up device is any one of the above.

Images