JP2011079387A - Vehicular seat belt device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular seat belt device capable of reliably switching limit loads. <P>SOLUTION: The seal belt device for preventing looseness of a webbing due to a pretensioner 10 prior to a crash selects between absorbing energy only by a torsion bar and absorbing energy by both the torsion bar and an EA plate according to the occupant's weight from actuation of the pretensioner 10 until completion of winding of the webbing 5 in order to regulate the rotation of a spool 13 during drawing of the webbing 5, so that a load applied to the occupant from the webbing 5 is reliably selected to protect the occupant. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle seat belt device, and more particularly to a seat belt retractor that winds up a seat belt.

  In the seat belt device of a vehicle, when the seat belt is installed and the seat belt is prevented from being pulled out in an emergency where a large deceleration load is applied as in the case of a vehicle collision, the seat is driven by an energy absorbing member such as a torsion bar. Some have an energy absorption mechanism that limits the load applied to the belt and absorbs and relaxes the impact energy of the occupant, that is, a so-called EA (Energy Absorption) mechanism.

JP 2006-306142 A

In the above conventional seat belt device, torsional deformation of the torsion bar and deformation of the energy absorbing member provided separately from the torsion bar are used in order to effectively and flexibly restrain and protect the occupant according to the emergency situation. Energy absorption is possible, and the case where energy is absorbed by both sides based on information such as the weight of the occupant and the case where energy is absorbed only by the torsion bar can be selected as necessary.
However, it is important to determine when the limit load is switched, and it is necessary to set the switching time to an optimum time.

  In view of the above, an object of the present invention is to provide a vehicle seat belt device capable of reliably switching a limit load.

  In order to achieve the above object, the invention described in claim 1 includes a spool (e.g., a spool 13 in the embodiment) for winding a webbing (e.g., the webbing 5 in the embodiment) and the spool at the time of pulling out the webbing. By restricting the rotation and allowing the spool to rotate when the webbing is taken up (for example, the locking base 35 in the embodiment) and the spool and the locking unit are connected, the load applied to the webbing is limited. First webbing load limiting means (for example, the torsion bar 14 in the embodiment) and second webbing load limiting means (for example, the EA plate 37 in the embodiment) provided on the spool and for limiting the load applied to the webbing. ) And the lock means by the lock means. A pretensioner (for example, the pretensioner 10 in the embodiment) that rotates the spool and winds up the slack of the webbing prior to restricting the rotation of the spool when pulling out the web, the first webbing load limiting means, Control means (for example, the control device 11 in the embodiment) for operating the second webbing load limiting means is provided, and the control means finishes winding the webbing by the pretensioner operation after the pretensioner operation. In the meantime, only the first webbing load limiting unit is operated or both the first webbing load limiting unit and the second webbing load limiting unit are operated.

  According to a second aspect of the present invention, there is provided rotation angle detection means (for example, the rotation angle sensor 84 in the embodiment) for detecting the rotation angle of the spool, and the control means is configured to detect the rotation angle detection means. Based on the rotation angle of the spool, the rotation angular velocity is calculated, and when the rotation angular velocity is zero, only the first webbing load limiting unit is operated, or the first webbing load limiting unit and the second webbing are operated. It is characterized by switching whether to operate both of the load limiting means.

  According to a third aspect of the present invention, there is provided rotation angle detection means for detecting the rotation angle of the spool, and the control means calculates the rotation angular velocity based on the rotation angle of the spool detected by the rotation angle detection means. Calculate and switch between operating only the first webbing load limiting unit or operating both the first webbing load limiting unit and the second webbing load limiting unit when the rotational angular velocity is maximum. It is characterized by that.

According to the first aspect of the present invention, only the first webbing load limiting means is provided between the time after the pretensioner operation in which only the rotational load is applied to the spool until the end of the webbing winding by the pretensioner operation. In setting the driving force for driving the members necessary for switching, in order to perform the operation of switching between operating the first webbing load limiting unit and the second webbing load limiting unit. The driving force can be easily grasped only by considering only the rotational angular velocity. Therefore, it is possible to switch between operating only the first webbing load limiting unit or operating both the first webbing load limiting unit and the second webbing load limiting unit.
According to the second aspect of the present invention, when the rotational angular velocity is zero and the spool is not rotating, it is not necessary to consider the influence of the centrifugal force of the spool. The driving force for can be set.
According to the third aspect of the present invention, when the rotational angular velocity that is easy to grasp is maximum, the centrifugal force acting on the spool is maximum, so that only the maximum centrifugal force is considered based on this. Thus, it is possible to easily set the driving force for switching the load limiting means described above.

It is explanatory drawing of the seatbelt apparatus of embodiment of this invention. It is explanatory drawing which shows a retractor and the whole system. It is the perspective view which showed EA mechanism. It is a principal part disassembled perspective view of FIG. 3 which abbreviate | omitted the locking base. It is a principal part front view of FIG. It is a principal part perspective view of FIG. It is explanatory drawing after the action | operation of FIG. It is a flowchart figure at the time of the vehicle collision which performs EA operation | movement. It is a flowchart figure of EA selection processing. It is a graph which shows the load which acts on webbing at the time of a collision.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of a seat belt device 1 according to an embodiment of the present invention. A retractor 4 that winds up a webbing 5 that restrains the occupant 3 is disposed in a center pillar (not shown) on the side of the seat 2. The webbing 5 drawn upward from the retractor 4 is inserted into a through anchor 6 supported on the upper side of the center pillar, and the tip thereof is fixed to the vehicle body floor via an outer anchor 7 on the outer wall of the seat 2. A tongue plate 8 inserted into the webbing 5 between the anchor 6 and the outer anchor 7 can be attached to and detached from a buckle 9 on the vehicle body floor near the inner wall of the seat 2 to constitute a so-called three-point seat belt device 1.

  The webbing 5 is wound around the retractor 4 in an initial state, and the occupant 3 pulls it out by hand to fix the tongue plate 8 to the buckle 9, thereby restraining the chest and abdomen mainly of the occupant 3 with respect to the seat 2. To do. In addition, the seat belt device 1 rotates the spool 13 prior to restricting the rotation of the spool 13 when the webbing is pulled out by a locking unit, which will be described later, at the time of a collision, and the pretensioner 10 automatically winds the webbing 5. Is to do. The pretensioner 10 is driven and controlled via the control device 11.

  As shown in FIGS. 2 and 3, the retractor 4 has a spool 13 that winds the webbing 5 around both side walls 12 a and 12 b of a frame-like frame 12 and is rotatably supported via a torsion bar 14. A flange portion 15 is formed on one end side of the spool 13, and an EA plate holding flange 16 having a diameter larger than that of the flange portion 15 is formed on the other end side. A return spring 17 (see FIG. 2) that constantly urges the spool 13 in the winding direction M of the webbing 5 is provided on one side wall 12a of the frame 12. A pretensioner 10 including a pipe 18, a ball 19, a gas generator 20, and a ring gear (not shown) is provided on one side wall 12a of the frame 12 in order to rotate the spool 13 in the M direction and retract the webbing 5 in an emergency. Yes.

  On the other side wall 12b of the frame 12, there is a retainer 22 that supports a lock actuating drum (see FIG. 2) 21 inside, and a vehicle sensor that senses vehicle acceleration below the retainer 22 and locks the rotation of the lock actuating drum 21. 24 is provided. A drive device 27 including a gas generator 25 and a piston 26 is provided below the vehicle sensor 24.

As shown in FIG. 4, the EA plate holding flange 16 includes an outer flange portion 30 and a ring portion 31 that is formed so as to rise inside the outer flange portion 30. The ring portion 31 includes a bottomed cylindrical case 32 that is rotatable with respect to the EA plate holding flange 16. An insertion hole 34 (see FIG. 3) of the torsion bar 14 is formed in the bottom wall 33 of the case 32.
One end of the torsion bar 14 is supported on the one side wall 12a side of the frame 12 so as not to rotate, and is linked to the return spring 17 and the ring gear of the pretensioner 10 described above.

  The other end of the torsion bar 14 protrudes outward from the other side wall 12b of the spool 13 and the bottom wall 33 of the case 32, and is lightly press-fitted to a locking base 35 (not shown in FIG. 4) shown in FIG. The locking base 35 is lightly press-fitted into an EA ring 36 that can rotate with respect to the case 32 on the bottom wall 33 of the case 32.

Here, when the locking operation drum 21 is locked by the vehicle sensor 24, the locking base 35 is linked to the pawl, which is a claw (not shown) of the locking base 35, and has internal teeth (not shown) on the other end side of the frame 12. And the rotation in the H direction is locked.
Therefore, when the load acting on the webbing 5 from the occupant exceeds a certain level while the locking base 35 is locked and unable to rotate, the torsion bar 14 is twisted to limit the load applied to the occupant, and the spool 13 is The load is absorbed by rotating the webbing 5 in the H direction, which is the pulling direction of the webbing 5.
Here, when the spool 13 rotates in the M direction which is the winding direction of the webbing 5 with the locking base 35 locked, the lock operation drum 21 and the locking base 35 are unlocked and the spool 13 is allowed to rotate. . The locking base 35 mainly constitutes a locking means.

As shown in FIG. 5, the EA ring 36 has an EA plate 37 that is a member that absorbs energy. The EA ring 36 includes a locking portion 38 on the outer peripheral wall, and the bent end 39 on the inner peripheral side of the EA plate 37 is fixed to the locking portion 38, and the other end on the outer peripheral side of the EA plate 37 is the peripheral wall 40 of the case 32. It is locked to.
The EA plate 37 is a member in which a belt-like (circular cross-section) elastic member is wound in an annular shape, and is substantially clockwise around the bent end 39 as viewed from the other end side of the torsion bar 14 (M direction). Thus, when the spool 13 is rotated in the H direction with the locking base 35 fixed, the bent portion of the bent end 39 gradually moves in the H direction, and is deformed in the direction in which the EA plate 37 is wound to save energy. Absorb.

  As shown in FIGS. 6 and 7, the EA plate holding flange 16 of the spool 13 has a slit 50 formed in the outer flange portion 30 and the ring portion 31. The slit 50 extends in the longitudinal direction of the torsion bar 14. A guide groove 51 formed in the circumferential direction of the ring portion 31 along the outer flange portion 30 and an insertion groove 52 formed in the radial direction in the ring portion 31 are provided. A clutch 53 is attached to the slit 50 so as to be able to appear and retract while sliding along the longitudinal direction of the torsion bar 14. The clutch 53 is aligned with the outer surface of the peripheral wall 56 of the ring portion 31 and inserted into the insertion groove 52, the protrusion 54 that fits into the guide groove 51 of the slit 50, the trigger portion 55 that protrudes from the upper surface of the outer flange portion 30. A locking portion 58 that locks into a locking groove 57 formed on the outer surface of the 32 peripheral walls 40 is provided.

The clutch 53 is held on the EA plate holding flange 16 by a resin clip 60 with the trigger portion 55 protruding from the EA plate holding flange 16 and the locking portion 58 locked on the locking groove 57 of the case 32. Yes.
The clip 60 has a T-shaped clip base 61 that is engaged with the end surface of the ring portion 31 of the EA plate holding flange 16 and a leg portion 62 that extends from the inner end of the clip base 61 toward one end of the torsion bar 14. The leg 62 is provided with a locking projection 63 at the tip. The locking projection 63 is locked in a groove 64 formed in the clutch 53 to hold the clutch 53. When the trigger portion 55 of the clutch 53 is pressed, the locking projection 63 breaks and the clutch 53 Allow movement.

  Therefore, the case 32 rotates integrally with the EA plate holding flange 16 and cannot rotate with respect to the EA plate holding flange 16 in a state where the locking portion 58 of the clutch 53 is locked in the locking groove 57 of the case 32. It has become. Therefore, since the locking base 35 is connected to the spool 13, a load is applied to the webbing 5 from the occupant more than a certain amount in a state in which the locking base 35 is not rotated, and the spool 13 is forced in the pulling direction H of the webbing 5. When the torsion bar 14 is twisted through the case 32 and the EA plate 37 is wound up, the energy is absorbed and the spool 13 is rotated in the H direction (see FIG. 5) which is the pulling-out direction of the webbing 5. Absorb energy.

  Further, when the clutch 53 is released from the locking groove 57 of the case 32, the case 32 can freely rotate with respect to the EA plate holding flange 16, so that the spool 13 moves in the pulling direction H of the webbing 5. Since the case 32 does not follow the force even when the force is received, the torsion bar 14 is only twisted, and the EA ring 36 relatively entrains the EA plate 37 via the EA ring 36 due to the torsion bar 14 being twisted. Even if the case 32 is deformed in the direction, the EA plate 37 cannot be deformed in the entrainment direction only by rotating the case 32 in the M direction, and the energy absorption function of the EA plate is invalidated and the energy by the torsion bar 14 alone is absorbed. Is done.

As shown in FIGS. 3 to 5, on the EA plate holding flange 16, a clutch release actuator 70 fitted from the outside to the outer periphery of the ring portion 31 is attached to the inside of the other side wall 12 b of the frame 12. The clutch release actuator 70 is an annular member, and includes a dividing surface 71 in a direction orthogonal to the longitudinal direction of the torsion bar 14, and the dividing surface 71 has four inclined cam portions 72 (three may be provided). Is provided. The clutch release actuator 70 is divided into a driven ring 73 on one end side of the torsion bar 14 and a drive ring 74 on the other end side with a dividing surface 71 as a boundary.
The inclined cam portion 72 is provided with an inclined surface 75 that protrudes from the driven ring 73 side to the drive ring 74 side and increases clockwise (M direction) when viewed from the other end side of the torsion bar 14.

Therefore, when the drive ring 74 is rotated clockwise (M direction) as viewed from the other end side of the torsion bar 14 relative to the driven ring 73, the drive ring 74 causes the driven ring 73 to torsion in the inclined cam portion 72. The bar 14 is pushed toward one end side.
A plurality of holding portions 76 that hold the outer peripheral surface of the drive ring 74 and guide the pushing operation of the driven ring 73 with respect to the drive ring 74 along the longitudinal direction of the torsion bar 14 are formed on the outer peripheral surface of the driven ring 73. .

  An arm 77 extending radially outward of the drive ring 74 is formed integrally with the lower portion of the drive ring 74, and the piston 26 of the drive device 27 is in contact with a hook 78 formed at the tip of the arm 77. The drive ring 74 can be rotated clockwise (M direction) when viewed from the other end side of the torsion bar 14 through 77. A bracket 79 that supports the clutch release actuator 70 on the back surface of the other side wall 12 b of the frame 12 is provided in the lower half of the clutch release actuator 70.

  As shown in FIG. 2, a signal from the vehicle speed sensor 80, a signal from the G sensor 81, a signal from the SRS unit 82, and the like are input to the control device 11. Further, the seat 2 shown in FIG. 1 is provided with a weight sensor 83 that detects the weight of the occupant, and a detection signal of the weight sensor 83 is also input to the control device 11. Further, a rotation angle sensor 84 of the spool 13 is provided, and a pulse signal of the rotation angle sensor 84 is input to the control device 11. Based on the rotation angle of the spool 13 detected by the rotation angle sensor 84, the control device 11 calculates the rotation angular velocity and also calculates the rotation angular acceleration. Based on detection signals from the vehicle speed sensor 80, G sensor 81, SRS unit 82, weight sensor 83, and rotation angle sensor 84, from the control device 11 to the ten gas generators 20 of the pretensioner and the gas generator 25 of the drive device 27. A drive signal is output.

  Next, based on the flowchart shown in FIG. 8, the control which restrict | limits the load which acts on a passenger | crew from the webbing 5 of the seatbelt apparatus 1 after a vehicle collides is demonstrated. The following processing is performed by the control device 11.

  When the vehicle collides, the vehicle sensor 24 is actuated to lock the lock actuating drum 21, and the pawl of the locking base 35 that rotates in conjunction with this locks with the internal teeth of the frame 12 to lock the rotation of the locking base 35. . In step S1, the G sensor 81 detects a collision. In step S2, the collision activates the pretensioner 10, and then it is determined whether or not the occupant needs to be restrained by the seat belt device 1. . As a result of the determination, if the collision is a light collision (“no”), the process returns to step S1. If the collision is a large impact force (“yes”), the impact load is not yet applied to the occupant at the time of deformation of the vehicle body. The pretensioner 10 operates (step S3).

  The operation of the pretensioner 10 drives the gas generator 20 based on a signal from the control device 11, moves the ball 19 in the pipe 18, and rotates the spool 13 in the winding direction (M direction) of the webbing 5 via the ring gear. To do.

  Next, in step S4, load restriction selection (EA selection processing) described later is performed. The load limit is selected by driving the gas generator 25 of the drive device 27 based on a signal from the control device 11. By selecting the load restriction, the magnitude of the load acting on the occupant is switched from the webbing 5 according to the weight of the occupant. Specifically, it is selected whether the load is limited only by the torsion bar 14 or the load is limited by both the torsion bar 14 and the EA plate 37. Thereafter, in step S5, the operation of the pretensioner 10 ends.

  When the deformation of the vehicle body is completed and an impact load is applied to the occupant from the webbing 5, the spool 13 is locked again by the locking base 35 and the occupant receives the load from the webbing 5, but the load exceeds the limit value of the load received from the webbing 5. If this occurs, the torsion bar 14 and the EA plate 37 absorb the energy and start to deform when the load limit value is exceeded by only the torsion bar 14 or both the torsion bar 14 and the EA plate 37 in step S6 ( EA operation), the spool 13 rotates in the direction (H direction) to pull out the webbing 5.

Specifically, when the load restriction by both the torsion bar 14 and the EA plate 37 is selected in the EA selection process in step S4, a time point when a load higher than the low load in which only the torsion bar 14 is selected is applied. Since the webbing 5 can be loosened after the passenger has been restrained, it is possible to sufficiently restrain a heavy passenger (over a certain fixed weight that is arbitrarily set), and when only the torsion bar 14 is selected, It is possible to protect a light occupant (less than a certain constant weight set arbitrarily) from damage due to restraint by loosening the webbing 5 at a low load stage. Therefore, the passenger can be restrained by the tightening load of the webbing 5 suitable for the weight.
In step S7, the energy absorption by the torsion bar 14 and the EA plate 37 ends (EA operation ends), and the control ends.

FIG. 9 is a flowchart showing the EA selection process in step S4 of FIG. In step S10, the weight sensor 83 detects the weight (Wt) of the occupant. In step S11, it is determined whether or not the detected weight is greater than or equal to the set weight. If it is greater than or equal to the setting (“yes”), the limit load by both the torsion bar 14 and the EA plate 37 is selected. If it is less than the setting (“no”), the limit load by only the torsion bar 14 is selected. To finish the process.
Here, when the limit load by both the torsion bar 14 and the EA plate 37 is selected, the control device 11 outputs a signal that does not drive the gas generator 25 of the drive device 27 or does not output the signal itself. .

  On the other hand, when the selection is performed only by the torsion bar 14, the control device 11 drives the piston 26 by the gas generator 25 to press the arm 77 to output a signal for driving the gas generator 25 of the drive device 27, thereby driving the drive ring 74. Is rotated in the M direction. As a result, the driven ring 73 is pressed via the inclined surface 75 of the inclined cam portion 72, and the driven ring 73 moves to one end side of the torsion bar 14 and the clutch 53 protruding from the EA plate holding flange 16 of the spool 13. The trigger part 55 is pressed.

When the trigger portion 55 of the clutch 53 is pressed, the locking projection 63 of the clip 60 that restrains the clutch 53 is separated and broken from the leg portion 62, and the trigger portion 55 of the clutch 53 becomes the outer flange of the EA plate holding flange 16. The restraint of the case 32 that has been pushed downward from the portion 30 and restricted by the EA plate holding flange 16 of the spool 13 is released.
As a result, the case 32 can be rotated with respect to the EA plate holding flange 16, and even when the EA plate 37 locked to the locking portion 38 is subjected to a force in the compression direction by the rotation of the EA ring 36, the case 32 itself rotates. As a result, the energy function by the EA plate 37 is disabled, and only the torsion bar 14 is involved in energy absorption.

  FIG. 10 shows that only the torsion bar 14 is operated or the torsion bar 14 and the EA plate until the winding of the webbing 5 by the operation of the pretensioner (PT) 10 is completed (PT end). 37 is a graph showing the timing for switching whether to activate both of the members 37 and the load acting on the webbing 5, the vertical axis shows the load F acting on the webbing 5, and the horizontal axis shows the change in the load F with time t as a solid line. ing. A two-dot chain line indicates a change in the rotational angular velocity of the spool 13 when the pretensioner 10 is operated.

When the vehicle collides, the spool 13 is locked by the locking base 35 and the locking base 35 is connected to the spool. However, when the pretensioner 10 is operated (point a) before the impact load is applied to the occupant, the spool 13 is unlocked. The webbing 5 is subjected to a winding load in which the spool 13 rotates in the M direction with a slight delay from the operation of the pretensioner 10.
Then, the load acting on the webbing 5 for winding the pretensioner 10 suddenly rises and peaks in the graph (point b). When the winding of the spool 13 by the pretensioner 10 is finished (point c), the load is small. Become.

  When the energy absorption due to the deformation of the vehicle is completed and an impact load is applied to the occupant this time, the spool 13 is again locked by the locking base 35 (ReLock), and the occupant who is about to move to the front side after receiving the impact moves to the webbing 5. A large load acts, but when the load exceeds the load set by the torsion bar 14 or the torsion bar 14 and the EA plate 37, the torsion bar 14 or the torsion bar 14 and the EA plate 37 starts to deform (point e) and absorbs energy. However, since the spool 13 rotates in the H direction, the webbing 5 is pulled out from the spool 13 and the load received by the passenger from the webbing 5 is limited. Accordingly, a substantially constant load acts on the webbing 5 during that time. When the load acting on the occupant is reduced, energy absorption by the torsion bar 14 or the torsion bar 14 and the EA plate 37 is finished at the point f (EA end), and then the collision is finished.

Here, as shown in an enlarged view on the lower side of FIG. 10, during the period from the operation of the pretensioner 10 (PT operation) to the end (PT end) (horizontal axis t (msec)), step S4 in FIG. That is, the EA selection process shown in FIG. 9 is performed.
Although the timing for performing this processing is after the drive signal of the pretensioner 10 is output, strictly speaking, the mechanism operation time delay until the drive signal of the pretensioner 10 is mechanically operated from the output, and further the clutch release actuator It is desirable to consider a mechanism actuation delay time of 70.

  According to the above-described embodiment, only the torsion bar 14 is moved after the operation of the pretensioner 10, which only applies the load in the rotational direction to the spool 13, until the end of the winding of the webbing 5 by the operation of the pretensioner 10. In order to move the clutch 53 in consideration of only the centrifugal force acting by the rotation of the spool 13 in order to perform a selection operation (EA selection) for switching between operating the torsion bar 14 and the EA plate 37. What is necessary is just to set the force required for the required frictional force and the fracture | rupture of the clip 60. FIG. That is, the output setting of the gas generator 25 for driving the drive ring 74 of the clutch release actuator 70 may be set in accordance with the force. Therefore, it is possible to switch between operating only the torsion bar 14 or operating both the torsion bar 14 and the EA plate 37 with certainty.

Therefore, the clutch 53 reliably ensures the EA without considering any load or load acting from the vehicle body or load acting from the occupant other than the friction force acting when the clutch 53 generated by the centrifugal force applied to the spool 13 is moved. Since the selection can be made, the degree of freedom in design is increased. Further, since the force acting on the clutch 53 is small, the clutch 53 can be reduced in size, and the retractor 4 can be reduced in size.
Further, since the EA selection is performed after the pretensioner 10 is operated until the webbing 5 is completely wound by the operation of the pretensioner 10, the EA can be additionally used in the conventional seat belt device. No development is required and measures can be taken at low cost.

  Here, in the above-described embodiment, only the torsion bar 14 is operated or the torsion bar 14 and the EA plate 37 are operated after the pretensioner 10 is operated and until the winding of the webbing 5 is completed by the operation of the pretensioner 10. In the above description, the selection operation (EA selection) for switching between the two is activated. However, even within this range, when the rotational angular velocity of the spool 13 detected using the rotational angle sensor 84 is zero, that is, the pretensioner 10. When the spool 13 is not rotating at the time when the winding of the webbing 5 is completed, EA selection can be performed. By doing so, it is not necessary to consider the influence of the centrifugal force of the spool 13, so that the driving force of the clutch release actuator 70 for EA selection can be set more easily.

In addition, as shown by the two-dot chain line peak position in FIG. 10, the EA is selected in accordance with the maximum rotational angular velocity of the spool 13 detected using the rotational angle sensor 84, that is, when the centrifugal force of the spool 13 is maximum. This is advantageous in that it is easy to set as much as it is easy to grasp the peak, and it is not necessary to set more power than necessary.
For reference, the switching load line A for EA selection when setting at the maximum rotational angular velocity in FIG. 10 and the switching load line when EA selection is performed after pretensioner operation including elements other than the maximum rotational angular velocity. When B is described, it can be seen that the required load difference is large.

  The present invention is not limited to the above-described embodiment. For example, based on the rotational angular velocity detected by the rotational angle sensor 84, the rotational angular acceleration is calculated by the control device 11, and when the rotational angular acceleration is zero, EA You can also make a selection. In such a case, there is a flat portion in the graph of the rotational angular velocity shown by the two-dot chain line in FIG. 10, but when there is a state of rotating at a constant rotational angular velocity in this way. If EA selection is performed, EA selection can be performed with a surely set load even if there is a slight deviation in timing.

5 Webbing 10 Pretensioner 11 Control device (control means)
13 Spool 14 Torsion bar (first webbing load limiting means)
35 Locking base (locking means)
37 EA plate (second webbing load limiting means)
84 Rotation angle sensor (Rotation angle detection means)

Claims (3)

  A spool that winds up the webbing, a lock unit that restricts rotation of the spool when the webbing is pulled out and allows rotation of the spool when winding the webbing, and the spool and the lock unit are connected to each other, thereby connecting the webbing First webbing load limiting means for limiting the load applied to the spool, second webbing load limiting means provided on the spool for limiting the load applied to the webbing, and the spool when the webbing is pulled out by the locking means. A pretensioner for rotating the spool and winding up the slack of the webbing before regulating the rotation, and a control unit for operating the first webbing load limiting unit and the second webbing load limiting unit, The control means is provided with the pretensioner after the operation. Only the first webbing load limiting unit is operated until the winding of the webbing by the tensioner operation is completed, or both the first webbing load limiting unit and the second webbing load limiting unit are operated. A seat belt device for a vehicle, wherein the operation is switched.   Rotation angle detection means for detecting the rotation angle of the spool is provided, and the control means calculates a rotation angular speed based on the rotation angle of the spool detected by the rotation angle detection means, and the rotation angular speed is zero. 2. The method according to claim 1, wherein at least one of the first webbing load limiting unit and the first webbing load limiting unit and the second webbing load limiting unit are both switched. Vehicle seat belt device.   Rotation angle detection means for detecting the rotation angle of the spool is provided, and the control means calculates a rotation angular speed based on the rotation angle of the spool detected by the rotation angle detection means, and the rotation angular speed is maximum. 2. The method according to claim 1, wherein at least one of the first webbing load limiting unit and the first webbing load limiting unit and the second webbing load limiting unit are both switched. Vehicle seat belt device.

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