JP2009184520A - Webbing winding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a webbing winding device firmly fixing a gas generator. <P>SOLUTION: The webbing winding device has a second cylinder 108 formed integrally with a base 86. The gas generator 112 is partially stored within an end part of the second cylinder 108. A cap 114 stores both the second cylinder 108 and the gas generator 112, and is attached to an attaching strip 18A of a frame 12 so that the gas generator 112 is fixed via the metal cap 114 to the attaching strip 18A of the metal frame 12. Thus, the gas generator 112 is firmly fixed to the end part of the second cylinder 108 so that the gas generator 112 is prevented from separating from the second cylinder 108 by the load of high pressure gas even when the gas generator 112 discharges the high pressure gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a webbing take-up device that limits a load applied to an occupant from a webbing by a force limiter mechanism.

  As a webbing take-up device, a level for absorbing energy acting on the webbing from the occupant (equal to a load acting on the occupant from the webbing, hereinafter referred to as “energy absorption level”) is set to the first level and the first level by the pyrotechnic actuator. There is one that can be switched between two levels (for example, see Patent Document 1).

  In the pyrotechnic actuator of this webbing take-up device, the pyrotechnic material is fixed in one end of the housing, and energy is absorbed depending on whether the pyrotechnic material generates gas and supplies gas to the housing. The level is switched between the first level and the second level.

  By the way, switching of the energy absorption level by the pyrotechnic actuator does not require a large force like a so-called pretensioner mechanism. For this reason, it is desirable to reduce the weight by making the housing resin.

However, the pyrotechnic material is preferably firmly fixed because it receives gas pressure.
JP 2005-522379 A

  In view of the above facts, an object of the present invention is to obtain a webbing take-up device capable of firmly fixing a gas generator.

  The webbing take-up device according to claim 1 is configured such that the webbing that can be attached to the occupant is taken up and rotated in the take-up direction so that the webbing is taken up and rotated in the pull-out direction. A winding shaft from which the webbing is pulled out, an arrangement member in which the winding shaft is rotatably arranged, and allowing the webbing to be pulled out over the limit load of the webbing at a predetermined opportunity to act on the occupant from the webbing A force limiter mechanism for limiting the load to be limited to the limit load, and a gas generator are arranged on the supply member, and the gas generated by the gas generator can be supplied to the supply member so that the limit load can be switched. And a fixing member that is attached to the arrangement member and fixes the gas generator.

  A webbing take-up device according to a second aspect is the webbing take-up device according to the first aspect, wherein the fixing member accommodates the supply member.

  In the webbing take-up device according to claim 1, the take-up shaft is rotatably arranged inside the arrangement member, and the webbing that can be attached to the occupant is taken up by the take-up shaft. The webbing is taken up by rotating the shaft in the winding direction, and the webbing is drawn out by rotating the winding shaft in the drawing direction.

  Further, the force limiter mechanism allows the webbing to be pulled out beyond the limit load of the webbing at a predetermined opportunity, and limits the load acting on the occupant from the webbing to the limit load. Further, in the switching mechanism, the gas generator is arranged on the supply member, and the gas generated by the gas generator can be supplied to the supply member, so that the limit load by the force limiter mechanism can be switched.

  Here, the fixing member is attached to the arrangement member, and the gas generator is fixed. For this reason, a gas generator can be firmly fixed.

  In the webbing take-up device according to the second aspect, the fixing member attached to the arrangement member accommodates the supply member. For this reason, even when the supply member is reduced in weight, the supply member can be prevented from being damaged by the pressure of the fluid generated by the gas generator.

  Next, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 5 is a sectional view schematically showing the configuration of the webbing take-up device 10 according to the embodiment of the present invention.

  As shown in this figure, the webbing take-up device 10 includes a metal frame 12 as an arrangement member. The frame 12 includes a plate-like back plate 14 that is fixed to the vehicle body. A leg plate 16 extends substantially perpendicularly to the back plate 14 from one end in the width direction of the back plate 14. On the other hand, a leg plate 18 extends from the other end in the width direction of the back plate 14 in the same direction as the extending direction of the leg plate 16, and the frame 12 has a substantially concave shape in plan view.

  A spool 20 as a take-up shaft is provided between the leg plate 16 and the leg plate 18, and the spool 20 is disposed in the frame 12. The spool 20 has an axial direction along the opposing direction of the leg plate 16 and the leg plate 18, and a base end portion of a long belt-like webbing belt 22 (seat belt) as a webbing is provided at an intermediate portion in the axial direction. It is locked. The spool 20 is wound in the winding direction (in the direction of arrow A in FIG. 2) which is one of its axes, so that the webbing belt 22 is wound and stored from the base end side, and the other is the drawer around the axis. The webbing belt 22 is pulled out by being rotated in the direction (the direction of arrow B in FIG. 2).

  On the other hand, the spool 20 is hollow along its central axis, and a force limiter mechanism and a torsion shaft 24 as a first energy absorbing member are accommodated inside thereof. The torsion shaft 24 includes a spool side coupling portion 26. The spool side coupling portion 26 is located between both axial ends of the spool 20, and the torsion shaft 24 is integrally connected to the spool 20 at the spool side coupling portion 26.

  A rod-shaped first deformable portion 28 is formed continuously from the end surface of the spool side coupling portion 26 on the leg plate 16 side. A first coupling portion 30 is formed coaxially and integrally with the first deformation portion 28 at the distal end side of the first deformation portion 28, and rotates to constitute a first lock mechanism 32 as a first lock means. A first coupling portion 30 is coaxially and integrally connected to a first lock base 34 as a body.

  The first lock base 34 is fitted from the end of the spool 20 on the leg plate 16 side so as to be coaxially rotatable relative to the spool 20. However, as described above, the first coupling portion 30 is integrally connected to the first lock base 34, so that the first lock base 34 is basically coaxial and integral with the spool 20. Connected.

  A first lock pawl 36 is provided on the radially outer side of the first lock base 34. The first lock pawl 36 is rotatably supported by the leg plate 16, and when the first lock pawl 36 rotates in a predetermined direction, the ratchet teeth formed on the first lock pawl 36 approach the outer periphery of the first lock base 34. Thus, the ratchet teeth formed on the outer peripheral portion of the first lock base 34 can be engaged with each other.

  On the other hand, a rotary member 38 is provided on the opposite side of the spool 20 via the first lock base 34 so as to be rotatable relative to the first lock base 34 in a coaxial manner. It is configured to follow and rotate with respect to the first lock base 34 by a biasing force of a biasing means (not shown) such as a coil spring.

  Although not shown in detail, the first lock mechanism 32 is provided with one or more restricting means for restricting the rotation of the rotating member 38, so that the vehicle is suddenly decelerated (a vehicle having a predetermined opportunity). When a large inertia is generated in the vehicle in an emergency) or when the first lock base 34 suddenly rotates in the pull-out direction, this restricting means is activated and the rotation of the rotating member 38 is restricted. The first lock pawl 36 is a relative rotation between the first lock base 34 and the rotation member 38 that occurs when the first lock base 34 attempts to rotate in the pull-out direction while the rotation of the rotation member 38 is restricted. Interlocked with the outer periphery of the first lock base 34.

  On the other hand, a rod-shaped second deformable portion 40 is continuously formed from the end surface of the spool side coupling portion 26 on the leg plate 18 side. A second coupling portion 42 is formed coaxially and integrally with the second deformation portion 40 at the distal end side of the second deformation portion 40, and constitutes a second lock mechanism 44 as a second lock means. The second coupling portion 42 is coaxially and integrally connected to the two lock base 46.

  The second lock base 46 is inserted from the end of the spool 20 on the leg plate 18 side so as to be coaxially rotatable relative to the spool 20. However, as described above, since the second coupling portion 42 is integrally connected to the second lock base 46, the second lock base 46 is basically coaxial and integral with the spool 20. Connected.

  As shown in FIGS. 1 and 2, the second lock base 46 is formed with a pair of pawl housing portions 48. These pawl housing portions 48 are open at a part of the outer periphery of the second lock base 46 and open at the end surface of the second lock base 46 opposite to the spool 20. A second lock pawl 50 is housed in these pawl housing portions 48. Each second lock pawl 50 is pivotally supported by a pawl support pin 52 formed in the pawl housing 48 so as to be rotatable about an axis parallel to the spool 20. Each of the second lock pawls 50 is basically housed in the pawl housing portion 48, but when the second lock pawl 50 rotates to one side around the pawl support pin 52, the distal end side of each second lock pawl 50 is the outer periphery of the pawl housing portion 48. Projecting outward from the opening in the part.

  On the other hand, a rotating disk 54 is provided on the opposite side of the spool 20 via the second lock base 46. The rotating disk 54 is pivotally supported on the spool 20 so as to be relatively rotatable coaxially with the spool 20. A pair of guide pins 56 project from the end face of the rotating disk 54 on the second lock base 46 side. These guide pins 56 are provided corresponding to the second lock pawl 50 described above.

  A long hole 58 is formed in each of the second lock pawls 50 corresponding to the guide pins 56, and the guide pin 56 enters the long hole 58. The long hole 58 has a width that is slightly larger than the outer diameter of the guide pin 56, and when the guide pin 56 rotates together with the rotating disk 54 to one side around the spool 20, the guide pin 56 moves along the inner wall of the long hole 58. The second lock pawl 50 is pressed to rotate around the pawl support pin 52.

  Further, a flat plate 60 projects from the end face of the rotating disk 54 on the second lock base 46 side. A rectangular spring accommodating hole 62 is formed in the second lock base 46 corresponding to the plate 60. A rotating disk biasing spring 64 is accommodated inside the spring accommodation hole 62.

  The rotating disk biasing spring 64 is a compression coil spring, one end of which is in pressure contact with the inner wall of the spring accommodating hole 62, and the other end is in pressure contact with the plate 60 entering the inside of the spring accommodating hole 62. The rotating disk 54 can be rotated to one side around the spool 20 when the plate 60 receives the urging force of the rotating disk urging spring 64. When the rotating disk 54 is rotated in this direction, the guide pin 56 is moved to the first position. The two-lock pawl 50 is rotated to one side around the pawl support pin 52.

  On the other hand, as shown in FIGS. 5 and 6, a through hole 66 is formed at the bottom of the spring accommodation hole 62. A stopper accommodating hole 70 is formed in the spool 20 corresponding to the through hole 66. The stopper receiving hole 70 is parallel to the axis of the spool 20, one end opens at the end of the spool 20 on the first lock base 34 side, and the other end of the spool 20 on the second lock base 46 side. It opens at the end, and the inner diameter of the stopper accommodation hole 70 does not change from one end to the other end.

  Inside the stopper accommodating hole 70, a second energy absorbing member and a stopper wire 74 as a control means are accommodated. The stopper wire 74 is formed in a long rod shape along the axial direction of the spool 20, and one end side of the stopper wire 74 extends from the opening end of the stopper receiving hole 70 on the first lock base 34 side to the outside of the stopper receiving hole 70. Protruding.

  Further, at least one of the end portion of the spool 20 on the first lock base 34 side and the end portion of the first lock base 34 on the spool 20 side corresponding to the portion of the stopper wire 74 protruding from the spool 20 (this embodiment) In the embodiment, a wire guide groove 82 (see FIG. 7A) is formed in the end portion of the spool 20. The wire guide groove 82 is curved with the central axis of the spool 20 as the center of curvature, and one end side of the stopper wire 74 enters the inside of the wire guide groove 82 and is curved following the wire guide groove 82.

  Further, one end of the stopper wire 74 is bent toward the first lock base 34 in the wire guide groove 82 and enters the wire locking hole 84 formed in the first lock base 34 also shown in FIG. It is out.

  On the other hand, the other end of the stopper wire 74 protrudes from the end of the stopper receiving hole 70 on the second lock base 46 side to the outside of the spool 20. Further, the stopper wire 74 passes through the through-hole 66 and enters the inside of the spring accommodating hole 62 on the opposite side of the rotating disk biasing spring 64 via the plate 60 and rotates by the biasing force of the rotating disk biasing spring 64. The other end of the stopper wire 74 interferes with the plate 60 to be tried.

  As shown in FIGS. 1 and 2, a resin base 86 (force limiter body) is integrally connected to the leg plate 18 outside the leg plate 18. A circular hole 88 is formed coaxially with the spool 20 in the base 86. The circular hole 88 has a sufficiently larger inner diameter than the second lock base 46, and the second lock base 46 passes through the circular hole 88. A lock ring 90 as a moving member is rotatably supported in the circular hole 88. The lock ring 90 is formed in a ring shape as a whole. Further, an inner ratchet 92 is formed on the inner peripheral portion of the lock ring 90, the second lock pawl 50 rotates to one side around the pawl support pin 52, and the distal end side of the second lock pawl 50 is the pawl housing portion 48. The second lock pawl ratchet 94 on the distal end side of the second lock pawl 50 meshes with the inner ratchet 92.

  Further, an outer peripheral groove 96 having a triangular cross section as an engaged portion is formed on a part of the outer periphery of the lock ring 90. A cam receiving hole 98 communicating with the circular hole 88 is formed in the base 86 corresponding to the outer peripheral groove 96. Inside the cam accommodation hole 98, a substantially rectangular plate-shaped cam 100 as an operating member is provided. The cam 100 is rotatably supported by a support shaft 102 that protrudes from the leg plate 18, and the support shaft 102 is disposed on the pulling direction side of the outer peripheral groove 96 of the lock ring 90. The cam 100 is configured such that a corner portion 100A on one end side as an engaging portion can be engaged with a winding direction side surface 96A of the outer peripheral groove 96 of the lock ring 90. A rotational force in a direction away from the outer peripheral groove 96 of the lock ring 90 is applied. A shear pin 104 as a positioning means that protrudes from the leg plate 18 passes through the cam 100, thereby restricting the rotation of the cam 100, so that the corner portion 100 </ b> A of the cam 100 is an outer peripheral groove 96 of the lock ring 90. Is engaged (contacted) with the winding side surface 96A.

  When the corner portion 100A of the cam 100 is engaged with the winding direction side surface 96A of the outer circumferential groove 96 of the lock ring 90, when the lock ring 90 tries to rotate in the pull-out direction, the corner portion 100A of the cam 100 is moved to the lock ring 90. The outer circumferential groove 96 is pressed in the pull-out direction by the winding direction side surface 96A, and a rotational force acts in a direction in which the corner portion 100A is separated from the outer circumferential groove 96 of the lock ring 90 on the cam 100. By being regulated by the shear pin 104, the shear pin 104 receives the rotational force in the pull-out direction of the lock ring 90, and the rotation of the lock ring 90 in the pull-out direction is restricted (blocked).

  A cylindrical first cylinder 106 as an additional supply member is integrally formed on the base 86 below the cam 100, and the inside of the upper end of the first cylinder 106 communicates with the cam housing hole 98. A piston 110 as a drive member is accommodated inside the first cylinder 106, and the upper end of the piston 110 projects into the cam accommodation hole 98.

  A cylindrical second cylinder 108 serving as a supply member is integrally formed on the base 86 below the first cylinder 106, and the inside of one end of the second cylinder 108 is within the lower end of the first cylinder 106. It is communicated.

  A gas generator 112 (micro gas generator, switching squib) as a gas generator is partially accommodated in the other end of the second cylinder 108, and the second cylinder 108 and the gas generator 112 are used as fixing members. The cap 114 is made of metal and has a substantially bottomed cylindrical shape. A substantially annular plate-like flange portion 114A is integrally formed on the outer periphery of the opening end of the cap 114, and the flange portion 114A is attached to an attachment piece 18A as an attachment portion formed integrally with the leg plate 18, The cap 114 is attached to the attachment piece 18 </ b> A by being attached by fastening (screwing) a predetermined number of screws 116, and the gas generator 112 is fixed to the other end of the second cylinder 108.

  Inside the gas generator 112, a chemical such as an igniting agent and a gas generating agent, and an ignition device that ignites the igniting agent when an electric ignition signal is input are accommodated. The ignition device of the gas generator 112 is connected to an ECU (control device) (not shown).

  In addition to the acceleration sensor that detects the sudden deceleration state of the vehicle, the ECU has suddenly decelerated the vehicle, such as a distance measuring sensor that detects that the distance to the obstacle in front of the vehicle is less than a certain value. And a danger prediction means for directly or indirectly detecting that the vehicle is likely to suddenly decelerate, a load sensor for detecting a load acting on the seat of the vehicle, and the webbing belt 22 is pulled out from the spool 20 by a certain amount. It is directly or indirectly connected to both physique detection means for directly or indirectly detecting the physique of the occupant seated on the seat, such as a belt sensor for detecting the fact.

  Based on a signal from the danger prediction means, the ECU determines that the vehicle is suddenly decelerated or that the vehicle is likely to decelerate, and the physique of the occupant seated in the seat is predetermined. When it is determined that the value is less than the value, an ignition signal is output from the ECU to the ignition device of the gas generator 112, and the gas generator 112 is operated.

  When an ignition signal is input to the ignition device of the gas generator 112, the igniting agent is ignited. Further, when the ignited ignition agent burns the gas generating agent, gas (fluid) is instantaneously generated inside the gas generator 112. As a result, gas is supplied from the second cylinder 108 to the first cylinder 106. The pressure of the gas acts to push (drive) the piston 110 upward in the first cylinder 106, and the piston 110 pushed upward from the first cylinder 106 presses the other end side portion of the cam 100 upward. As a result, the cam 100 is rotated (operated) in a direction in which the corner portion 100 </ b> A is separated from the outer peripheral groove 96 of the lock ring 90 while breaking the shear pin 104.

  The base 86 is covered with a resin cover (not shown) as a covering member on the side opposite to the leg plate 18, and the second lock mechanism 44 is accommodated inside the cover.

  Next, the operation and effect of the present embodiment will be described.

(Operation of the first lock mechanism 32)
When the webbing belt 22 pulled out from the spool 20 is attached to the body of a vehicle occupant, for example, when the vehicle is suddenly decelerated and the first lock mechanism 32 is activated, The rotation of the rotating member 38 in the drawing direction is restricted.

  Next, when an occupant's body, which intends to move forward due to inertia at the time of sudden deceleration of the vehicle, tries to rotate the spool 20 in the pull-out direction by suddenly pulling the webbing belt 22, it is integrated with the spool 20 via the torsion shaft 24. The first lock bases 34 connected to each other rotate in the pull-out direction.

  Here, in this state, when the rotation of the rotation member 38 in the pull-out direction is restricted as described above, relative rotation occurs between the first lock base 34 and the rotation member 38, and the first lock pawl 36. Approaches the first lock base 34.

  As a result, the ratchet teeth of the first lock pawl 36 mesh with the ratchet teeth of the first lock base 34, and the rotation of the first lock base 34 in the pull-out direction, and hence the rotation of the spool 20 in the pull-out direction, is restricted. Pulling out the webbing belt 22 from the spool 20 is restricted. Thereby, the passenger | crew's body which is going to move ahead with the webbing belt 22 can be restrained reliably.

(Operation of the torsion shaft 24)
As described above, in the state where the rotation of the first lock base 34 is regulated by the first lock pawl 36, the occupant's body pulls the webbing belt 22 with a greater force, and the spool 20 in the pull-out direction based on this pulling force. When the rotational force exceeds the mechanical strength of the first deformable portion 28, the first deformable portion 28 is twisted while the first coupling portion 30 remains connected to the first lock base 34, and the spool 20 is twisted by this twist amount. Rotates in the pull-out direction.

  Therefore, the webbing belt 22 is pulled out from the spool 20 by the amount of rotation of the spool 20 in the pulling direction. As a result, the restraining force of the occupant by the webbing belt 22 is slightly weakened, and the energy used for pulling the webbing belt 22 is absorbed by the amount of torsional deformation.

(Operation of stopper wire 74)
Furthermore, as described above, the fact that the spool 20 rotates in the pull-out direction with respect to the first lock base 34 means that the first lock base 34 rotates in the winding direction relative to the spool 20. It is. Thus, when the first lock base 34 rotates in the winding direction with respect to the spool 20, one end of the stopper wire 74 remains in the wire locking hole 84 formed in the first lock base 34. The stopper wire 74 is pulled while being guided by the wire guide groove 82 of the first lock base 34.

  However, the stopper wire 74 has a longitudinal direction along the axial direction of the spool 20 inside the stopper accommodating hole 70, whereas the first lock base 34 pulls the stopper wire 74 in the winding direction. Therefore, as shown in FIG. 7B, the stopper wire 74 pulled by the first lock base 34 is squeezed at the edge of the opening end of the stopper accommodating hole 70 on the first lock base 34 side. Following the guide groove 82, the guide groove 82 is deformed so that its longitudinal direction is the longitudinal direction of the wire guide groove 82, that is, the rotational circumferential direction of the spool 20.

  As described above, even when the stopper wire 74 is pulled and deformed, the restraining force of the occupant by the webbing belt 22 is slightly weakened, and the energy used for pulling the webbing belt 22 by the amount of deformation of the stopper wire 74 is increased. The amount of energy absorbed by the stopper wire 74 is superposed on the amount of energy absorbed by the twist of the first deformable portion 28, and the energy used for pulling the webbing belt 22 can be effectively absorbed.

(Operation of the second lock mechanism 44)
Further, as described above, when the stopper wire 74 moves toward the first lock base 34 inside the stopper accommodation hole 70, the other end side of the stopper wire 74 that has entered the spring accommodation hole 62 has a through hole 66. It passes through and disengages from the spring accommodation hole 62 and is drawn into the stopper accommodation hole 70 from the end of the stopper accommodation hole 70 on the lock base 46 side. Thus, when the stopper wire 74 comes out of the spring accommodating hole 62, the interference of the stopper wire 74 with the plate 60 is eliminated. The plate 60 from which the interference from the stopper wire 74 has been eliminated rotates in the spring accommodating hole 62 by receiving the biasing force of the rotating disk biasing spring 64.

  Since the plate 60 is integral with the rotating disk 54, the rotating disk 54 rotates in the winding direction with respect to the second lock base 46 by rotating the plate 60 by the biasing force of the rotating disk biasing spring 64. To do. When the rotary disk 54 rotates in the winding direction with respect to the second lock base 46, the guide pin 56 presses the inner wall of the long hole 58 to rotate the second lock pawl 50 to one side around the pawl support pin 52.

  Thus, when the second lock pawl 50 rotates, the tip of the second lock pawl 50 protrudes to the outside of the second lock base 46, and the second lock pawl ratchet 94 at the tip of the second lock pawl 50 is connected to the lock ring 90. It meshes with the inner ratchet 92 (see FIG. 3).

  By the way, the spool 20 on which the webbing belt 22 is pulled is going to rotate in the pull-out direction. For this reason, the second lock pawl 50 tries to rotate in the pull-out direction together with the second lock base 46.

  Accordingly, the rotational force of the second lock base 46 in the pull-out direction is transmitted to the lock ring 90 with which the second lock pawl 50 is engaged, and the lock ring 90 tends to rotate in the pull-out direction. In this state, if the corner portion 100 </ b> A of the cam 100 is engaged with the winding direction side surface 96 </ b> A of the outer peripheral groove 96 of the lock ring 90, rotation of the lock ring 90 in the pull-out direction is restricted by the cam 100.

  When the rotation restriction of the lock ring 90 in the pull-out direction is made, the rotation of the second lock base 46 in the pull-out direction is also restricted. In this state, the rotational force in the pull-out direction of the spool 20 based on the pulling force when the occupant's body pulls the webbing belt 22 causes the mechanical strength of the first deformable portion 28 and the mechanical strength of the second deformable portion 40. The second deformable portion 40 is twisted together with the first deformable portion 28 while the second coupling portion 42 remains connected to the second lock base 46, and the spool 20 is pulled in the pull-out direction by this twist amount. Rotate.

  Therefore, the webbing belt 22 is pulled out from the spool 20 by the amount of rotation of the spool 20 in the pulling direction. As a result, the restraining force of the occupant by the webbing belt 22 is slightly weakened, and the energy used for pulling the webbing belt 22 is absorbed by the amount of torsional deformation. For this reason, energy absorption occurs due to torsional deformation of the first deformation portion 28 and the second deformation portion 40, and the limit load by the torsion shaft 24 is increased.

  On the other hand, as shown in FIG. 4, before the first lock mechanism 32 operates, the vehicle is in a sudden deceleration state or a state immediately before sudden deceleration, and the ECU is seated on the seat based on a signal from the physique detection means. When it is determined that the occupant's physique is less than a predetermined reference value, and an ignition signal is output from the ECU, the gas generator 112 is activated. When the gas generator 112 is activated, the piston 110 is pushed upward of the first cylinder 106 and the other end side portion of the cam 100 is pushed upward, so that the cam 100 is rotated while breaking the shear pin 104, The corner portion 100 </ b> A of the cam 100 is separated from the outer peripheral groove 96 of the lock ring 90.

  In this state, when the rotational force in the pull-out direction of the spool 20 is transmitted to the lock ring 90 via the second lock base 46 and the second lock pawl 50, the lock ring 90 rotates in the pull-out direction together with the spool 20. Therefore, in this state, the first deformable portion 28 is twisted, but the second deformable portion 40 is not twisted. For this reason, only energy absorption due to torsional deformation of the first deformable portion 28 occurs, and the limit load by the torsion shaft 24 is reduced.

  That is, in the present embodiment, by controlling the gas generator 114, a mode in which the second deformable portion 40 is deformed (high load mode) and a mode in which the second deformable portion 40 is not deformed (low load mode). ) And can be switched. Thereby, it is possible to absorb energy appropriately according to the physique of the occupant wearing the webbing belt 22.

  Incidentally, the second cylinder 108 is formed integrally with the base 86, and the gas generator 112 is partially accommodated in the other end of the second cylinder 108.

  Here, the cap 114 accommodates the second cylinder 108 and the gas generator 112 and is attached to the attachment piece 18 </ b> A of the frame 12. Therefore, the gas generator 112 can be fixed to the attachment piece 18A of the metal frame 12 via the metal cap 114. Thereby, even when the gas generator 112 generates high-pressure gas, the gas generator 112 can be prevented from being separated from the second cylinder 108 by the load of the high-pressure gas, and the gas generator 112 is connected to the other end of the second cylinder 108. Can be firmly fixed.

  Further, a metal cap 114 accommodates the second cylinder 108 and is attached to the attachment piece 18 </ b> A of the metal frame 12. Therefore, even when the gas generator 112 generates high-pressure gas, it is opposite to the deformation of the peripheral wall of the second cylinder 108 in the radial direction due to the load of the high-pressure gas and the gas generator 112 on the one end wall of the second cylinder 108. The deformation to the side can be prevented. Thereby, even when the base 86 (including the second cylinder 108) is made of resin and reduced in weight, damage to the base 86 (including the second cylinder 108) due to the pressure of the gas generated by the gas generator 112 can be suppressed. The weight of the base 86, and hence the webbing take-up device 10, can be reduced.

  In the present embodiment, the present invention is applied to the second lock mechanism 44. However, the present invention may be applied to a pretensioner mechanism (not shown) of the webbing take-up device 10. In the pretensioner mechanism, a pinion is coaxially fixed to the spool 20, a piston provided with a rack is accommodated in a cylinder (supply member), and a gas generator (gas generator) is accommodated at one end of the cylinder. ing. As a result, in a vehicle emergency (predetermined opportunity), the gas generator generates gas, and the piston is moved in the cylinder by the gas pressure, so that the pinion is rotated by the rack and the spool 20 is wound up. Rotate in the direction. Here, at least one end of the cylinder and the gas generator are accommodated in a metal cap (fixing member), and the cap is attached to an attachment piece (attachment portion) formed integrally with the frame 12 so that the cylinder is made of resin. Even if the weight is reduced, damage to the cylinder can be suppressed.

It is a disassembled perspective view which shows the structure of the 2nd locking mechanism of the webbing retractor which concerns on embodiment of this invention. It is a front view which shows the outline of a structure of the 2nd locking mechanism in the webbing winding apparatus which concerns on embodiment of this invention. It is a front view corresponding to FIG. 2 which shows the operation state of the 2nd lock mechanism in the webbing winding device concerning an embodiment of the invention. It is a front view corresponding to FIG. 2 which shows the lock release state of the lock ring of the 2nd lock mechanism in the webbing retractor according to the embodiment of the present invention. It is front sectional drawing which shows the outline of a structure of the webbing winding apparatus which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of a part of 2nd lock mechanism of the webbing winding apparatus which concerns on embodiment of this invention. It is a front view which shows the positional relationship of the spool and stopper wire in the webbing winding device concerning an embodiment of the invention, (A) shows the state before a stopper wire moves, and (B) moves a stopper wire. Shows the state. It is a front view of the 1st lock base in the webbing winding device concerning an embodiment of the invention.

Explanation of symbols

10 Webbing take-up device 12 Frame (arrangement member)
20 Spool (winding shaft)
22 Webbing belt (webbing)
24 Torsion shaft (force limiter mechanism)
108 Second cylinder (supply member)
112 Gas generator
114 Cap (fixing member)

Claims (2)

A webbing wound around the occupant is wound up, and the webbing is wound up by being rotated in the winding direction, and the webbing is pulled out by being rotated in the pulling direction; and
An arrangement member in which the winding shaft is rotatably arranged;
A force limiter mechanism that allows the webbing to be pulled out over the limit load of the webbing at a predetermined opportunity and limits the load acting on the occupant from the webbing to the limit load;
A switching mechanism in which a gas generator is disposed on a supply member, and the gas generated by the gas generator can be supplied to the supply member so that the limit load can be switched;
A fixing member attached to the arrangement member and fixing the gas generator;
A webbing take-up device comprising:   The webbing take-up device according to claim 1, wherein the fixing member accommodates the supply member.

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