JP2014227106A - Seat belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat belt device allowing adjustment of prohibition of permission of rotation of a spool part in time of a lock.SOLUTION: A seat belt device 10 includes: a spool part 42 capable of winding a webbing 13; a rotation detection part 39 detecting a rotation number of the spool part 42; a lock mechanism 34 capable of locking rotation of the spool part 42; a torsion bar part 22a permitting the rotation of the spool part 42 when the spool part 42 is locked by the lock mechanism 34; a control part 35 determining whether or not the rotation number of the spool part 42 reaches a permissible rotation number; and a rotation prohibition mechanism 49 capable of prohibiting pulling-out of the webbing 13 from the spool part 42. When the rotation number reaches the permissible rotation number, the control part 35 generates a rotation prohibition signal, and the rotation prohibition mechanism 49 (for example, an inflator 44) operates according to the rotation prohibition signal, and prohibits the permission of the rotation of the spool part 42 by the torsion bar part 22a.

Description

  The present invention relates to a seat belt device or the like having a lock mechanism capable of locking a webbing drawer in an emergency such as a vehicle collision.

  For example, FIG. 1 of Patent Literature 1 discloses a seat belt retractor 3 of a seat belt device, and FIG. 3 of Patent Literature 1 shows a spool 9, a locking base 20, and a torsion constituting a webbing reel stored in the seat belt retractor 3. Bar 12 etc. are disclosed. In order to lock the pull-out of the webbing from the webbing reel in the event of an emergency such as a vehicle collision, the spool 9 of Patent Document 1 is locked via the locking base 20 and the torsion bar 12. Specifically, when the locking base 20 of Patent Document 1 is locked, rotation of the upper portion of the torsion bar 12 (first torque transmitting portion 18) is prohibited, while the torsional deformation of the torsion bar 12 causes the lower portion of the torsion bar 12 to rotate. The rotation of the (second torque transmission unit 24) is allowed and the rotation of the spool 9 is also allowed. Thus, since the rotation of the spool 9 is allowed, the webbing can be pulled out from the spool 9, and the burden on the occupant due to the webbing in an emergency is reduced.

JP 2012-30636 A

  However, with the end of the torsional deformation of the torsion bar 12 of Patent Document 1, the rotation of the spool 9 is prohibited from being allowed to rotate, and the end of the torsional deformation of the torsion bar 12 depends on the specifications of the torsion bar 12. . In other words, once the specification of the torsion bar 12 is designed or determined, the end of torsional deformation of the torsion bar 12 is fixed. Therefore, the seat belt device of Patent Document 1 cannot adjust the prohibition of the rotation of the spool 9 when locked.

  FIG. 3 of Patent Document 1 discloses a stopper 23 and an energy absorbing (EA) member 27. When the stopper 23 is movable, the torsional deformation of the torsion bar 12 may be limited by crushing the energy absorbing member 27. it can. However, since the amount of movement or the number of rotations of the stopper 23 depends on the specification of the stopper 23, once the specification of the stopper 23 is designed or determined, the amount of movement or the number of rotations of the stopper 23 is fixed. As a result, the end of the torsional deformation of the torsion bar 12 is fixed. Therefore, the seat belt device of Patent Document 1 including the stopper 23 and the energy absorbing member 27 cannot adjust the prohibition of the rotation of the spool 9 when locked.

  One object of the present invention is to provide a seat belt device capable of adjusting the prohibition of the rotation of the spool portion when locked. Other objects of the present invention will become apparent to those skilled in the art by referring to the aspects and preferred embodiments exemplified below and the accompanying drawings.

  In the following, in order to easily understand the outline of the present invention, embodiments according to the present invention will be exemplified.

In the first aspect, the seat belt device comprises:
A spool portion capable of winding the webbing;
A rotation detection unit for detecting the number of rotations of the spool unit;
A lock mechanism capable of locking the rotation of the spool portion;
A tone bar portion that allows the spool portion to rotate when the spool portion is locked by the locking mechanism;
A controller that determines whether or not the rotational speed reaches an allowable rotational speed;
A rotation prohibiting mechanism capable of prohibiting the withdrawal of the webbing from the spool portion;
With
When the rotation speed reaches the allowable rotation speed, the control unit generates a rotation prohibition signal,
The rotation prohibition mechanism operates in response to the rotation prohibition signal and prohibits the rotation of the spool portion by the tone bar portion.

  According to the first aspect, even when the spool portion is locked by the locking mechanism, the rotation of the spool portion is allowed by the torsional deformation of the tone bar portion. The rotation detection unit detects the number of rotations of the spool unit locked by the lock mechanism, and the control unit determines whether or not the number of rotations reaches a preset allowable number of rotations. When the rotation speed reaches the allowable rotation speed, the control unit generates a rotation prohibition signal, and the rotation prohibition mechanism operates according to the rotation prohibition signal. As a result, the rotation of the spool portion at the time of locking is prohibited. In other words, by adjusting the preset allowable rotation speed, the seat belt device can adjust the prohibition of the rotation of the spool portion when locked.

In a second aspect dependent on the first aspect, the seat belt device comprises:
It may further comprise a sheet part state detection part for detecting the state of the sheet part,
The control unit may set the allowable rotational speed based on the state of the seat unit.

  According to the 2nd aspect, the sheet | seat part state detection part can detect the state of a sheet | seat part. In other words, the seat belt device can adjust the prohibition of the rotation of the spool portion when locked according to the state of the seat portion.

In a third aspect subordinate to the second aspect,
The seat state detection unit may detect a seat position and a seat back reclining angle as the state of the seat unit.

  According to the third aspect, the seat belt device can adjust the prohibition of the rotation of the spool portion at the time of locking according to the position of the seat and the reclining angle of the seat back.

In a fourth aspect depending on the second or third aspect, the seat belt device comprises:
An occupant physique detection unit that detects the physique of the occupant seated in the seat part may further be provided,
The control unit may set the allowable rotation speed based on the state of the seat unit and the physique of the occupant.

  According to the fourth aspect, the seat belt device allows the rotation of the spool portion at the time of locking according to both the occupant's physique and the state of the seat portion (for example, the position of the seat and the reclining angle of the seat back). The ban can be adjusted.

  Those skilled in the art will readily understand that the illustrated embodiments according to the present invention can be further modified without departing from the spirit of the present invention.

The structural example of the seatbelt apparatus according to this invention is shown. An explanatory view of a plurality of data which the control part of Drawing 1 handles is shown. The explanatory view of the lock mechanism and rotation prohibition mechanism of the retractor of FIG. 2 is shown. Explanatory drawing of the rotation detection part and power transmission mechanism of the retractor of FIG. 3 is shown. FIG. 3 is an explanatory diagram of an allowable rotational speed set in advance in the control unit of FIG. 2. An explanatory view of a state of a sheet part of Drawing 1 is shown. The operation example of the control part of FIG. 2 is shown.

  The preferred embodiments described below are used to facilitate an understanding of the present invention. Accordingly, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below.

  FIG. 1 shows a configuration example of a seat belt device according to the present invention. As shown in FIG. 1, for example, a seat belt device 10 provided in a vehicle such as an automobile includes a retractor 16 that can wind up a webbing 13 that restrains the body of an occupant 11 such as a driver or a passenger to a seat portion 12. Is provided. The retractor 16 is controlled by a control unit 35 called, for example, a seat belt ECU (electronic control unit), and the webbing 13 restrains, for example, the first portion 13a that restrains the upper body of the occupant 11 and the waist of the occupant 11. And a second portion 13b. In FIG. 1, for example, one end (or the second portion 13 b side) of the webbing 13 is fixed to the vehicle body portion at the lower part of the passenger compartment by an anchor plate 14. Further, for example, the other end (the first portion 13a side) of the webbing 13 is folded back by a through anchor 15 provided near the shoulder of the occupant 11, and the webbing belt reel in the retractor 16 (FIG. 3 or 4). It is connected to the inner spool part 42). A tongue plate 17 is attached to the webbing 13, and the webbing 13 is detachably attached to, for example, a buckle 18 fixed near the bottom of the seat portion 12 via the tongue plate 17. The buckle 18 is provided with a buckle switch 19 that detects the connection between the tongue plate 17 and the buckle 18. When the buckle switch 19 is turned on, the control unit 35 determines that the belt 13 is attached to the occupant 11. Can do.

  The seat belt device 10 may not include all of the components such as the retractor 16 illustrated in FIG. 1, such as the webbing 13, the tongue plate 17, the buckle 18, and the control unit 35, or each of these components. Some may be provided, and in addition, other components described below may also be provided. In other words, the seat belt device 10 of FIG. 1 is only shown as an exemplary embodiment, and for at least one purpose of the invention, the seat belt device 10 comprises at least one component. Can do.

  FIG. 2 is an explanatory diagram of a plurality of signals handled by the control unit 35 of FIG. As shown in FIG. 2, the control unit 35 is connected to, for example, the sensor unit 51, and the signal from the sensor unit 51 determines whether or not the current state is an emergency state such as a vehicle collision, sudden deceleration, or sudden steering. Can be detected. The sensor unit 51 in FIG. 2 includes at least one sensor, and the sensor unit 51 can be configured by an acceleration sensor, for example. Further, the control unit 35 may be connected to, for example, another ECU 52, and may input a signal indicating a detection result in the other ECU 52, and detects whether or not the current state is an emergency state based on the signal. May be. In other words, the control unit 35 can detect whether or not the current state is an emergency state based on signals from the sensor unit 51 and other external devices 53 such as the ECU 52.

  When the current state is an emergency state, specifically, when the rearward acceleration of the vehicle is greater than or equal to a predetermined acceleration, the control unit 35 can send a signal to the retractor 16. For example, the actuator 38 of the retractor 16 can lock the rotation of the spool portion 42 in FIG. 3 or 4 by a signal from the control portion 35. However, since the shaft (rotating shaft) of the spool portion 42 is constituted by the torsion bar portion 22a, the rotation of the spool portion 42 at the time of locking is allowed by the torsional deformation of the tone bar portion 22a. Therefore, the rotation detection unit 39 of the retractor 16 can detect the rotation number of the spool unit 42 and send a signal indicating the rotation number of the spool unit 42 to the control unit 35.

  When the current state is an emergency state, the control unit 35 can next determine whether or not the rotation speed of the spool section 42 reaches the allowable rotation speed. When the rotation speed reaches the allowable rotation speed, the control unit 35 can send a signal (rotation prohibition signal) to the retractor 16. For example, the inflator 44 of the retractor 16 is ignited by a signal (rotation prohibition signal) from the control unit 35, thereby prohibiting the rotation of the spool unit 42 by the torsion bar unit 22 a. By adjusting the preset allowable rotational speed, the seat belt device 10 can adjust the prohibition of the rotation of the spool portion 42 when locked.

  FIG. 3 is an explanatory view of the locking mechanism and the rotation prohibiting mechanism of the retractor 16 of FIG. As shown in FIG. 2, the retractor 16 can include a lock mechanism 34 and a rotation prohibiting mechanism 49. In FIG. 3, the lock mechanism 34 includes, for example, an actuator 38, a first locking portion 37, and a first locked portion 36. When the present is an emergency state, the actuator 38 can move the first locking portion 37, whereby the first locking portion 37 (claw portion) is moved to the first locked portion 36 ( Locking to the first gear portion of the locking base). Since the first locking portion 37 is fixed to the webbing reel frame 31, the first locked portion is locked when the first locking portion 37 is locked to the first locked portion 36. The rotation of 36 is locked with respect to the webbing reel frame 31.

  However, since one end and the other end of the torsion bar portion 22a are connected to the first locked portion 36 and the spool portion 42, respectively, the rotation of the spool portion 42 is locked via the lock mechanism 34. Even so, the rotation of the spool portion 42 at the time of locking is permitted by the torsional deformation of the tone bar portion 22a. However, when the rotation speed of the spool section 42 after the rotation of the spool section 42 is locked via the lock mechanism 34 reaches the allowable rotation speed, the rotation inhibition mechanism 49 receives a signal (a rotation inhibition signal) from the control section 35. ) To permit the rotation of the spool portion 42 by the torsion bar portion 22a.

  In FIG. 3, the rotation prohibiting mechanism 49 includes, for example, an inflator 44, a second locking portion 43, a second locked portion 41, and the like. When the rotational speed of the spool portion 42 reaches the allowable rotational speed, the inflator 44 is ignited, the first protrusion of the ring portion 45 provided outside the spool portion 42 is pushed, and the entire ring portion 45 rotates. To do. As the ring portion 45 rotates, the second protrusion 46 of the ring portion 45 rides on the protrusion 47 of the webbing reel frame 31. In other words, the ring portion 45 moves away from the base of the webbing reel frame 31 and approaches the second locked portion 41. Thereby, the 2nd latching | locking part 43 (claw part) can latch to the 2nd to-be-latched part 41 (2nd gear part of a locking base). Since the second locking portion 41 is fixed with respect to the spool portion 42, when the second locking portion 41 is locked to the second locked portion 41, The rotation (that is, the rotation of the spool portion 42) is prohibited with respect to the second locked portion 41 (and the webbing reel frame 31 via the lock mechanism 34).

  As described above, when the rotation speed of the spool portion 42 reaches the allowable rotation speed, the rotation prohibiting mechanism 49 can prohibit the withdrawal of the webbing 13 from the spool portion 49 (drawing direction 13d). A rotation detection unit 39 (see FIG. 4) that detects the number of rotations of the spool unit 42 when locked can be provided on the webbing reel frame 31. Also, when the present is an emergency condition, the actuator 38 may not be activated immediately. In other words, when the current state is an emergency state, the control unit 35 performs winding of the webbing 13 on the spool unit 49 (reverse direction of the pulling direction 13d) via the power transmission mechanism 24 (see FIG. 4), and then In addition, the actuator 38 may be activated. In this case, the actuator 38 sends a signal indicating the operation time of the actuator 38 (that is, when the spool portion 42 is locked by the lock mechanism 34) to the control unit 35, and the control unit 35 operates after the actuator 38 is operated ( That is, the rotation speed of the spool portion 42 after the rotation of the spool portion 42 is locked via the lock mechanism 34 can be grasped.

  In the lock mechanism 34 of FIG. 3, the actuator 38 is electrically operated in accordance with a signal from the control unit 35. For example, when the rearward acceleration of the vehicle is equal to or higher than a predetermined acceleration, or the webbing 13 is pulled out. When the speed is equal to or higher than a predetermined speed, the lock mechanism 34 itself may be mechanically operated, and the spool portion 42 may be locked to the webbing reel frame 31 via the torsion bar portion 22a. In this case, the control unit 35 may detect a predetermined acceleration, a predetermined speed, and the like by the sensor unit 51, the rotation detection unit 39, and the like. In other words, the control unit 35 locks the spool unit 42 by the lock mechanism 34. It is also possible to estimate the time at which the rotation is performed and grasp the subsequent rotation speed of the spool portion 42.

  FIG. 4 is an explanatory diagram of the rotation detector 39 and the power transmission mechanism 24 of the retractor 16 of FIG. As shown in FIG. 4, the spool unit 42 is normally rotatable with respect to the webbing reel frame 31, and the rotation detection unit 39 can detect the number of rotations of the spool unit 42. The rotation detection unit 39 is constituted by, for example, a rotation angle sensor, and the rotation angle sensor has, for example, a magnetic disk and two Hall ICs. In FIG. 4, a rotation detection unit 39 or a magnetic disk is provided on the shaft (torsion bar unit 22a) of the spool unit 42, and the rotation detection unit 39 or the two Hall ICs are, for example, alternating between an N-pole region and an S-pole region. Can output two pulse signals P1 and P2 representing the movement of the circumferential edge of the magnetic disk in which the above arrangement is repeated (that is, the rotational speed of the magnetic disk = the rotational speed of the spool section 42). The control unit 35 can input the detection result (for example, two pulse signals P1 and P2) from the rotation detection unit 39 and grasp the rotation speed of the spool unit 42.

  The retractor 16 may include a motor 23. In this case, the spool unit 42 is rotated by the motor 23 and the power transmission mechanism (gear mechanism) 24 until the spool unit 42 is locked by the lock mechanism 43. Can be done. In FIG. 4, the power transmission mechanism 24 is provided on the shaft (torsion bar portion 22 a) of the spool portion 42 and the drive shaft 23 a of the motor 23, and the spool portion 42 also rotates as the drive shaft 23 a of the motor 23 rotates. . At this time, the control unit 35 outputs a signal to the energization amount adjustment unit 28, and the energization amount adjustment unit 28 controls or adjusts the energization amount of the drive current I1 supplied from the power source 27 to the motor 23 according to the signal. be able to. As described above, the control unit 35 may control the driving current I1 of the motor 23 to control the rotation of the spool unit 42 (that is, winding of the webbing 13, for example). In other words, when the current state is an emergency state, the control unit 35 may function as an electric pretensioner mechanism.

  In FIG. 4, when the current state is an emergency state, the control unit 35 sets the lock mechanism 34 to, for example, the drive current I2 immediately without using the electric pretensioner mechanism or after using the electric pretensioner mechanism. Accordingly, the actuator 38 of the lock mechanism 34 is operated, and the spool portion 42 is locked with respect to the webbing reel frame 31. Thereafter, when the number of rotations of the spool unit 42 reaches the allowable number of rotations, the control unit 35 can control the rotation prohibiting mechanism 49 with, for example, the drive current I3, whereby the inflator of the rotation prohibiting mechanism 49 is activated. Accordingly, the rotation of the spool portion 42 is prohibited with respect to the webbing reel frame 31.

  Preferably, the control unit 35 sets the allowable number of rotations based on the state of the seat unit 12 in FIG. In this case, the seat portion 12 shown in FIG. 1 has, for example, a position adjustment structure capable of adjusting the position of the seat portion 12 in the front-rear direction in the passenger compartment and fixing the seat portion 12 at a predetermined position. doing. Moreover, the seat part 12 of FIG. 1 has an angle adjustment structure which can adjust the reclining angle of the seat part 12 in a vehicle interior and can fix the reclining angle at a predetermined angle, for example. For example, the other ECU 52 in FIG. 2 can be configured by a seat ECU capable of adjusting the state of the seat unit 12, and the control unit 35 can detect the detection result (for example, the seat unit 12) in the other ECU 52 (seat unit state detection unit). The position of the seat portion 12 such as the position of the seat portion 12 and the reclining angle of the seat portion 12) can be input.

  In addition, preferably, the control unit 35 sets the allowable rotation speed based on the physique of the occupant 11 seated on the seat unit 12 of FIG. In this case, the seat part 12 shown by FIG. 1 measures the weight of the passenger | crew 11, for example. For example, the sensor unit 51 of FIG. 2 can be configured by a weight sensor that detects the weight of the occupant 11 seated on the seat unit 12, and the control unit 35 detects the detection result (for example, the occupant physique detection unit) (for example, A signal representing the occupant 11's physique such as the weight of the occupant 11) can be input.

  The vehicle may include, for example, an SRS (supplemental restraint system), and the airbag ECU of the SRS is, for example, a weight sensor, a seat ECU, an acceleration sensor, and the like, for example, the presence or absence of the occupant 11, the physique of the occupant 11, 12, the reclining angle of the seat portion 12, the presence or absence of a vehicle collision, and the like can be grasped, and it can be determined whether or not to deploy an SRS airbag (not shown). In other words, for example, the airbag ECU can constitute the external device 53 such as the other ECU 52 of FIG. 1, and the control unit 35 (seat belt ECU) inputs various information grasped by the airbag ECU, The allowable rotation speed may be set, and thereafter, the time when the spool portion 42 is locked by the lock mechanism 34 may be estimated or determined.

  FIG. 5 is an explanatory diagram of the allowable rotational speed preset in the control unit 35 of FIG. For example, when an ACC (accessory) switch (not shown) is turned on, the power source of the control unit 35 (seat belt ECU) is turned on, and the control unit 35 executes a program for executing the flowchart shown in FIG. Run. In step S1, the control unit 35 determines whether or not an IG (ignition) switch (not shown) is turned on. When the IG switch is turned on, the control unit 35 outputs a signal indicating a detection result (for example, the weight of the occupant 11) in the occupant physique detection unit (for example, a sensor unit 51 such as a weight sensor, an airbag ECU, or another ECU 52). input.

  In step S <b> 2, the control unit 35 determines whether the weight of the occupant 11 is smaller than 30 [kg], for example, as the physique of the occupant 11. That is, the control unit 35 can determine whether the occupant 11 is small in size or whether the occupant is a child. When the weight of the occupant 11 is smaller than 30 [kg], the control unit 35 detects the detection result (for example, the position of the seat unit 12 and the position of the seat unit 12 and the other ECU 52 such as the seat ECU and the airbag ECU). A signal representing the reclining angle of the seat portion 12 is input.

  In step S <b> 3, the control unit 35 grasps the state of the sheet unit 12. Specifically, the control unit 35 determines the distance G from the headrest 12a of the seat unit 12 to the instrument panel 5 based on the position of the seat 12c (see FIG. 6) of the seat unit 12 and the angle of the seat back 12b of the seat unit 12. Calculate The control unit 35 classifies the distance G into, for example, three categories, and selects one of steps S4 to S6 based on the classified category (state of the seat unit 12) and the determination result in step S2 (physique of the occupant 11). Run one.

  For example, when the distance G is smaller than the first predetermined distance, step S4 is executed, and the distance G smaller than the first predetermined distance belongs to the first category (small), for example, and the allowable rotational speed. T is set to 0.5 rotation, for example. For example, when the distance G is equal to or larger than the first predetermined distance and the distance G is smaller than the second predetermined distance, step S5 is executed, and the distance G at that time Belongs to the second category (medium), for example, and the allowable rotation speed T is set to 1.5 rotations, for example. For example, when the distance G is equal to or larger than the second predetermined distance, step S6 is executed, and the distance G at that time belongs to, for example, the third category (large) and is allowed. The rotation speed T is set to 2.5 rotations, for example.

  When the weight of the occupant 11 is not smaller than 30 [kg], the control unit 35 calculates the distance G from the headrest 12a of the seat unit 12 to the instrument panel 5 as in step S3. The control unit 35 classifies the distance G into, for example, three categories, and selects one of steps S7 to S9 based on the classified category (state of the seat unit 12) and the determination result (physique of the occupant 11) in step S2. Run one. For example, when the distance G belongs to the first category (small), the allowable rotational speed T is set to 0 rotation, for example (see step S7). For example, when the distance G belongs to the second category (medium), the allowable rotational speed T is set to, for example, 1.0 rotation (see step S8). For example, when the distance G belongs to the third category (large), the allowable rotational speed T is set to, for example, 2.0 rotations (see step S9).

  Thus, the control unit 35 sets the allowable rotational speed T so that the allowable rotational speed T increases as the distance G increases. In addition, the control unit 35 sets the allowable rotational speed T so that the allowable rotational speed T increases as the physique of the occupant 11 decreases. By setting the allowable rotational speed T based on the state of the seat portion 12 and the physique of the occupant 11, the burden on the occupant 11 due to the webbing 13 in an emergency is more appropriately reduced.

  FIG. 6 is an explanatory diagram of the state of the sheet portion 12 of FIG. As shown in FIG. 6, the distance G from the headrest 12a of the seat portion 12 to the instrument panel 5 is based on the seat Bc position B of the seat portion 12 and the seat back 12b angle D of the seat portion 12 (formula ( 1) to (3)).

G = (E ² + F ² ) ^0.5 (1)
E = C × cos (D−π / 2) + B (2)
F = C × sin (D−π / 2) + A (3)

  Each of the distances A and C is a known value determined by the type of the vehicle, and the distance B and the angle D are determined by a seat part state detection unit (for example, another ECU 52 such as a seat ECU or an airbag ECU). Detected. The control unit 35 can calculate the distance G based on the detected distance B (position of the seat 12c) and angle D (reclining angle of the seat back 12b) (steps S3 and S7 in FIG. 6).

  FIG. 7 shows an operation example of the control unit 35 of FIG. For example, after the allowable rotational speed is set, the control unit 35 executes a program for executing the flowchart shown in FIG. In step S11, the control unit 35 determines whether or not the SRS airbag has been deployed. In other words, the control unit 35 inputs a signal from, for example, an SRS airbag ECU, and determines whether or not the current state is an emergency state. Immediately after the SRS airbag is deployed, the control unit 35 can control, for example, the actuator 38 of the retractor 16 to lock the rotation of the spool unit 42 in FIG. 3 or 4. The vehicle may not include the SRS, and instead of step S11, the control unit 35 may determine whether or not the lock mechanism 34 has locked the rotation of the spool unit 42.

  In step S <b> 12, the control unit 35 inputs the rotation speed of the spool unit 42 at the time of locking from the rotation detection unit 39. In other words, the control unit 35 sets the rotation speed of the spool section 42 immediately after the SRS airbag is deployed as the initial rotation speed, and the difference between the current rotation speed and the initial rotation speed (the spool section 42 at the time of locking). ).

  In step S13, the control unit 35 determines whether or not the rotation speed of the spool section 42 at the time of locking is equal to or greater than the allowable rotation speed. In other words, the control unit 35 determines whether or not the rotation speed (the rotation speed of the spool section 42 at the time of locking) of the spool section 42 immediately after the SRS airbag is deployed (initial rotation speed) reaches the allowable rotation speed. Determine whether. The control unit 35 repeats steps S12 and S13 until the rotation speed of the spool unit 42 at the time of locking reaches the allowable rotation speed. When the rotation speed of the spool unit 42 at the time of locking reaches the allowable rotation speed, the control unit 35 executes step S14.

  In step S14, the control unit 35 controls, for example, the inflator 44 of the retractor 16, and immediately after the SRS air bag is deployed, that is, immediately after the spool unit 42 is locked, the spool unit 42 rotates. Tolerance can be prohibited by using an arbitrarily set allowable rotation speed. As described above, the seat belt device 10 including the control unit 35 can control the rotation of the spool unit 42 due to the torsional deformation of the torsion bar unit 22a with the allowable number of rotations, and allow the rotation of the spool unit 42 when locked. The prohibition can be adjusted electrically.

  The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art will be able to easily modify the above-described exemplary embodiments to the extent included in the claims. .

  5 ... 10 ... Seat belt device, 11 ... Passenger, 12 ... Seat part, 12a ..., 12b ..., 12c ..., 13 ... Webbing, 13a, 13b ... Part, 13d ..., 14 ... Anchor plate, 15 ... Through anchor, 16 ... Retractor, 17 ... Tang plate, 18 ... Buckle, 19 ... Buckle switch, 22a ... Torsion bar section, 23 ... Motor, 23a ... Drive shaft, 24 ... Power transmission mechanism, 27 ..., 28 ..., 31 ... Webbing reel frame, 34 ... -Lock mechanism, 35 ... control part, 36 ... first locked part, 37 ... first locking part, 38 ... actuator, 39 ... rotation detection part, 41 ..Second locked part, 42 ... spool part, 3 ... second locking portion, 44 ... inflator, 45 ... ring portion, 46,47 ... projection portion, 49 ... rotation prohibiting mechanism, 51 ... sensor portion, 52. ..ECU, 53 ... external device

Claims (4)

A spool portion capable of winding the webbing;
A rotation detection unit for detecting the number of rotations of the spool unit;
A lock mechanism capable of locking the rotation of the spool portion;
A tone bar portion that allows the spool portion to rotate when the spool portion is locked by the locking mechanism;
A controller that determines whether or not the rotational speed reaches an allowable rotational speed;
A rotation prohibiting mechanism capable of prohibiting the withdrawal of the webbing from the spool portion;
With
When the rotation speed reaches the allowable rotation speed, the control unit generates a rotation prohibition signal,
The rotation prohibiting mechanism operates in response to the rotation prohibiting signal, and prohibits the rotation of the spool portion by the tone bar portion. A sheet part state detection unit for detecting the state of the sheet part;
The seat belt device according to claim 1, wherein the control unit sets the allowable rotational speed based on the state of the seat unit.   The seat belt device according to claim 2, wherein the seat state detection unit detects a seat position and a reclining angle of the seat back as the state of the seat unit. An occupant physique detector that detects the physique of the occupant seated in the seat part
4. The seat belt device according to claim 2, wherein the control unit sets the allowable rotational speed based on the state of the seat unit and the physique of the occupant.

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