JP5190434B2 - Seat belt retractor and control method - Google Patents

Description

  The present invention relates to a seat belt retractor and a control method, and more particularly, to a seat belt retractor and a control method using a motor retract system that can change a driving state of a seat belt mounted by a passenger and a signal from the outside. .

  In the seat belt retractor installed in automobiles, when the occupant is seated and pulls out the seat belt and the tongs are fastened to the buckle device, the extra pull-out is absorbed and the chest of the occupant is properly worn. It is preferable not to give an unnecessary feeling of pressure. In general, a seat belt retractor uses a biasing force of a single return spring for belt retracting. If a spring with a weak urging force is used to reduce the feeling of pressure on the chest of the occupant when worn, the wrapping force during winding of the belt (during housing) becomes weak, and operability and retractability are reduced. On the other hand, when a spring having a strong urging force is used in order to exert a sufficient entrainment force in an emergency, there is a problem that the feeling of pressure on the chest of the occupant during normal wearing increases.

  In addition, since the conventional seat belt retractor incorporates a single return spring, the amount of webbing (hereinafter referred to as webbing when referring to the seat belt itself) is reduced. As the number increases, the return spring is wound to increase its urging force, and as the webbing pull-out amount increases, the pull-out force also increases.

  As a means of solving the problem at the time of winding the belt caused by using this kind of single return spring, the applicant is composed of two rope pulleys having a truncated cone shape having a spiral guide groove. A tension reducer mechanism has been developed (see Patent Document 1).

  On the other hand, as a function of the seat belt retractor, the function (comfort performance) at the time of wearing a normal belt can be improved, or the vehicle can be used more than the function of reliably restraining and protecting an occupant in an emergency. A seat belt retractor for an occupant restraint protection system that detects the distance between the vehicle and the vehicle traveling in front of and behind the host vehicle and performs an electric motor with built-in tension control of the seat belt. It has been developed (see Patent Document 2).

Japanese Patent No. 2711428 JP-A-9-132113

  By the way, in the seat belt winding device disclosed in Patent Document 2, an ultrasonic motor is employed as a driving device for tension control, and a spring mechanism is provided as a main winding mechanism. This motor has been used to adjust the tension of the seat belt when the occupant wears the seat belt, and to control the take-up and withdrawal of the seat belt in response to an external signal input during traveling. For this reason, since it is necessary to rotate the motor drive forward and backward, the control circuit is complicated. Further, there are two systems for winding the seat belt, and there is a problem that the winding operation cannot be smoothly switched with respect to the input external signal.

  In addition, when external signals from various on-vehicle sensors are used as motor-driven triggers, the motor speed reduction mechanism used in the above-described seat belt retractor limits the decelerable range, so a wide range of retract modes There is also a problem that it is not possible to cope with. Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, so that the seat belt is wound only by the motor drive using a simple control circuit and drive mechanism, It is an object of the present invention to provide a seat belt retractor and a control method therefor, which can reduce the cost, so that the retract mode can be set widely according to an external signal.

In order to achieve the above object, according to the present invention, a spool that is supported on a base frame via a spool shaft and webbing is wound around the outer periphery is attached to the end of the spool shaft, and an urging force can be applied to the spool shaft. A seat belt winder that winds the webbing by a rewind release force of a return spring and switches a winding speed by a motor drive having a speed reduction mechanism by means of a switching mechanism of the speed reduction mechanism, mechanism comprises a transmission route which is set to a predetermined reduction ratio, via said transmission path, and a state signal obtained in the occupant of the seat belt mounting operation, the on-board sensing means to the vehicle during running of the vehicle the drive signal of the motor obtained from the running state signal obtained corresponding motor driving force of the changed speed reduction ratio by said switching means Characterized in that to transmit to said spool shaft.

Depending on the command of the state signal and the running condition signal, performs a switching operation of the path, it is preferable to carry out the winding of the webbing in a large reduction ratio by the reduction mechanism.

The transmission path is switched by the switching means according to a motor drive signal when receiving the state signal and the driving state signal, and the operation of a part of the transmission element provided in the speed reduction mechanism is stopped. It is preferable to be able to switch between.

Preferably, the switching means has a claw mechanism, and the claw mechanism is locked to ratchet teeth formed on the outer periphery of the internal gear of the planetary gear unit to fix the rotation of the internal gear.

As an invention for efficiently operating the winding device described above, when the occupant's seat belt mounting operation is started, the webbing that is initially wound by the motor rotation receives a state signal drawn by the occupant, permitting subsequent drawer stop motor rotation, undergo subsequent running state signal obtained from the mounted sensing means to the vehicle when the state signal及beauty car both travel of the webbing by the occupant operating, the rotational torque of the motor switches to the deceleration ratio corresponding to the condition signal or the traveling state signal, and controls the spool rotation, characterized in that the webbing was to take up on the spool.

  It is preferable to stop the rotation of the motor based on the state signal obtained by detecting the withdrawal of the webbing in the winding state.

  It is preferable that the webbing is wound by driving the motor with a driving torque value that allows the occupant to belt-fit based on a state signal obtained by detecting that the tongue is attached to the buckle.

  It is preferable that the driving torque value of the motor is reduced or the motor driving is stopped based on a state signal obtained by detecting that the belt fit is completed.

  Preferably, the motor is driven to resume the winding of the webbing based on a state signal obtained by detecting that the webbing withdrawal has been interrupted.

  With the tongue attached to the buckle, the webbing is resumed from the state where the webbing is pulled out and the pulling is interrupted, and then the motor driving torque value is decreased or the motor driving is stopped after the belt is fitted. It is preferable.

  The driving torque value of the motor in the belt fitting operation is preferably set lower than the value in the belt fitting operation when the tongue is first attached.

  It is preferable that the webbing is wound up in the winding device by driving the motor based on a state signal obtained by detecting that the tongue is separated from the buckle.

  It is preferable that the power source of the control circuit for driving the motor is turned on simultaneously with the detection of the webbing withdrawal or after a predetermined time has elapsed.

  When detecting that the webbing has been wound up, it is preferable to detect that there is no pulling-out operation at the same time or for a certain period of time and turn off the power supply of the control circuit for driving the motor.

The resulting status signals or the running state signal switching the driving torque value of said motor at a constant value or middle variable value depending on Toggles, it is preferred that by the motor drive to perform the winding of the webbing.

  As described above, a single motor equipped with a highly adaptable reduction mechanism can be controlled by setting various situations, or by combining it with a known winding mechanism, so that the webbing winding state can be set in various ranges. This is advantageous in that the comfort and safety of the occupant wearing the seat belt can be reliably ensured.

The disassembled perspective view which showed the component of one Embodiment of the seatbelt winding device by this invention. The disassembled perspective view which showed the component of the deceleration mechanism of the seatbelt winding device of this invention. The cross-sectional view which showed the transmission element inside a deceleration mechanism by the end surface. The cross-sectional view which showed the transmission element inside a deceleration mechanism by the cross section. The disassembled perspective view which showed the modification of the winding mechanism of a seatbelt winding apparatus. The disassembled perspective view which showed another modification of the winding mechanism of a seatbelt winding apparatus. The system block diagram which showed typically the component for controlling the mechanism group and apparatus which comprise the seatbelt winding device by this invention. The end view which showed the structure of the webbing drawer | drawing-out detection part and a spool rotation detection part. The state explanatory view showing typically composition and operation of a claw mechanism (the 1st example of composition). The partial exploded perspective view which showed the structure of the nail | claw mechanism (2nd structural example). FIG. 11 is a state explanatory diagram schematically showing the configuration and operation of the claw mechanism shown in FIG. 10. Explanatory drawing which showed typically the modification of the switching mechanism of a deceleration mechanism. State explanatory drawing which showed the cooperation operation state of a reduction gear and a sliding mechanism. State explanatory drawing which showed the switching operation state in a planetary gear unit. State explanatory drawing which showed the state which pulled out webbing at the time of webbing winding. The flowchart which showed the operation | movement flow in webbing winding-up control. The flowchart which showed the operation | movement flow of the setting mode process. The flowchart which showed the operation | movement flow for slack prevention at the time of belt mounting | wearing. The model state change figure which showed the relationship between the electric current in the webbing winding-up state, the amount of feed, and the webbing tension. The model state change figure which showed the motor speed control state according to drawing | extracting and winding-up of webbing. Explanatory drawing which showed typically the whole structure of the deceleration mechanism. Explanatory drawing which showed the modification of the 1st deceleration mechanism typically. Explanatory drawing which showed typically the modification of the 2nd deceleration mechanism. Explanatory drawing which showed typically the modification of the switching mechanism of a deceleration mechanism. Explanatory drawing which showed typically the modification of the sliding mechanism. Explanatory drawing which showed typically the modification of the sliding mechanism. Explanatory drawing which showed typically the modification of the webbing drawer | drawing-out detection part.

Hereinafter, an embodiment of a seat belt retractor and a control method thereof according to the present invention will be described with reference to the accompanying drawings.
[Configuration of seat belt retractor body]
Hereinafter, the configuration of the seat belt retractor according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a webbing take-up reel unit 2A as an assembly of a seat belt take-up device 1 of the present invention, a reel lock mechanism 4, a motor 5 as a drive source, a speed reduction mechanism casing 11 that houses a speed reduction mechanism, and a speed reduction mechanism 10 ( It is the disassembled perspective view which showed schematic structure of the planetary gear unit 30 and the detection parts 40 and 50 for motor control which comprise a part of FIG. FIG. 2 is an exploded perspective view showing the internal configuration of the speed reduction mechanism 10.

  In FIG. 1, the webbing take-up reel unit 2A and the reel lock mechanism 4 as a known mechanism are shown integrally. The webbing take-up reel unit 2A includes a spool 2 on which the webbing W is taken up, and a base frame 3 that rotatably supports a spool shaft 15 of the spool 2, and a reel lock mechanism 4 that suppresses the rotation of the spool 2. (Only the external shape is shown) is integrally attached to the base frame 3. In the present embodiment, a single variable speed DC motor 5 is provided as a drive source. A circuit device (not shown) is used for the control unit 9 (see FIG. 7) for controlling the rotation of the DC motor 5. Further, a speed reduction mechanism 10 is provided in the speed reduction mechanism casing 11 as a drive mechanism to which the rotational torque of the DC motor 5 is transmitted.

  The speed reduction mechanism 10 includes two systems of drive mechanisms, a first speed reduction mechanism 10A and a second speed reduction mechanism 10B, and realizes the winding operation of the spool 2 via any one system of drive mechanisms. . At this time, in order to prevent the rotational torque transmitted from one drive source such as a motor from being directly connected via the two systems, one of the transmitted torques is slid so as to slip through a predetermined resistance torque. As the resistance torque means 60, a sliding mechanism (hereinafter, denoted by reference numeral 60) is provided. By interposing this sliding mechanism 60, drive mechanisms having different reduction ratios are switched by the switching means 70 according to conditions.

  As shown in FIG. 1, the base frame 3 is a processed steel plate having a substantially U-shaped planar shape, and left and right side walls 3a are formed with support holes 3b into which end flanges of the spool 2 are loosely fitted. ing. A substantially serrated portion (not shown) (not shown) is formed on the peripheral edge 3c of the support hole 3b, and a locking piece (not shown) that swings by a locking operation of a known reel lock mechanism 4 is formed on the peripheral edge 3c. It is designed to be locked. By this locking operation, when the webbing W is suddenly pulled out from the winding device 1, the rotation of the spool 2 is locked and the webbing W is prevented from being pulled out. A speed reducer casing 11 in which an assembly of a speed reduction mechanism 10 for reducing the rotational driving force of the motor 5 is accommodated is attached to the other side wall 3a of the base frame 3 via a planetary gear unit. A webbing drawer detection unit 40 and a spool rotation detection unit 50 are attached to the outer end of the speed reducer casing 11 and the outer end of the reel lock mechanism 4, respectively. A motor gear 6 is inserted in the lower part of the inner surface of the speed reducer casing 11 so that a predetermined rotational driving force can be transmitted to an assembly (which will be described later) of the internal speed reduction mechanism 10. Note that the casing for housing the motor 5 is not shown for the sake of simplicity.

[Configuration of deceleration mechanism]
The configuration of the speed reduction mechanism 10 will be described with reference to FIGS. As described above, the speed reduction mechanism 10 is configured by integrating two systems of the first speed reduction mechanism 10 </ b> A and the second speed reduction mechanism 10 </ b> B by sharing some transmission elements. In the present embodiment, a claw mechanism 70 that operates with an electromagnetic solenoid 71 is used as the switching means 70 that switches the speed reduction mechanism 10.

  Components of the first speed reduction mechanism 10A will be described with reference to FIGS. FIG. 3 is an internal cross-sectional view showing each element (gear) in detail on the end face in order to explain the meshing state of the transmission element of the speed reduction mechanism 10 in the seat belt retractor 1, and FIG. It is the internal sectional view which showed each element (gear) in detail in the section in order to explain the support state of these transmission elements. First, the motor 5 is firmly attached to the lower end of the base frame in a state where the motor gear 6 is inserted into the lower hole formed in the speed reduction mechanism casing 11 as shown in FIGS. The motor gear 6 is meshed with a two-stage gear 12 that is pivotally supported on a rotating shaft (not shown) on the inner surface of the casing 11. Although the two-stage gear 12 has a two-piece configuration in FIG. 2, it may be configured as an integral gear. The small gear 12 a of the two-stage gear 12 meshes with the reduction gear 13. The rotating shaft boss 14 of the reduction gear 13 is fitted to a hexagonal cross-section bush 16 coaxially and integrally formed with a sun gear 31 (the planetary gear unit 30 will be described later) loosely fitted to the projecting shaft 15a of the spool shaft 15. The entire reduction gear 13 is supported by the protruding shaft 15a. A flat recess 13 a is formed on the entire outer surface of the reduction gear 13. A known rotary damper 17 is fixed to the side surface of the recess 13 a, and a gear 19 is pivotally supported on the rotor shaft 18 of the rotary damper 17. The rotary damper 17 is filled with oil, and a certain resistance torque is applied to the rotor shaft 18 by the viscous resistance of a rotor vane (not shown) that rotates in the oil. Further, the recess 13a of the reduction gear 13 accommodates a spool shaft input gear 20 fixed to a hexagonal spline 15b formed at the end of the protruding shaft 15a. A predetermined rotational torque is applied to the shaft end of the spool shaft 15 by the rotation of the spool shaft input gear 20.

  Further, the configuration of the planetary gear unit 30 that is coaxially mounted on the spool shaft 15 will be described with reference to FIG. 1, FIG. 3, and FIG. As clearly shown in the exploded perspective view of FIG. 1, the planetary gear unit has two planetary gears 32 that mesh with a sun gear 31 that rotates the same number as the reduction gear 13, and supports the planetary gears 32. The carrier 33 is coaxially rotatable with the sun gear 31 and the planetary gear 32 is composed of an internal gear 34 which is inscribed and meshed with the internal teeth 37. Among these, the carrier 33 has a socket portion 35 having a hexagonal shape on the back surface side, and when the socket portion 35 is inserted through the spool shaft 15, the carrier 33 is fitted to the enlarged diameter portion 15 c having a hexagonal shape. It has become. Furthermore, ratchet teeth 36 are formed on the outer periphery of the internal gear 34 over the entire periphery. The claw mechanism 70 as a switching mechanism that engages with the ratchet teeth 36 will be described in detail later. The internal gear 34 is fixed by the claw mechanism 70 being locked to the ratchet teeth 36, and the rotation input from the sun gear 31 is transmitted to the carrier 33 that rotates with the revolution of the planetary gear 32, and the socket portion 35 is Thus, the enlarged diameter portion 15c of the spool shaft 15 can be rotated at a large reduction ratio.

[Modification of winding mechanism]
(Swirl spring combined type)
Next, a modification in which a conventional spiral spring is incorporated as a return spring in a winding mechanism will be described with reference to FIG. In this modification, the rewinding release force of the return spring is used for winding the spool shaft during normal use in the configuration shown in FIG. A cotter 15d is formed at the protruding end of the spool shaft 15a, and a spring bush 101 is fitted therein. An inner peripheral end 102 a of a return spring 102 of a spiral spring is fixed to the spring bush 101. As a result, it plays a role of transmitting torque due to the winding and rewinding operations of the return spring 102 to the spool shaft 15. Further, a spring cover 103 is bolted (not shown) to the casing 11 so as to cover the entire return spring 102. In the seat belt retractor configured as described above, the webbing is retracted by the return spring 103 during normal use, and the motor 5 provided in a state where the seat belt needs to be retracted when the vehicle is running is driven. Webbing can also be taken up.

(Saving function face gear drive type)
FIG. 6 is a partial perspective view showing a partial configuration of a modified example of the speed reduction mechanism in which the above-described large reduction ratio function is omitted and the comfort of the occupant when wearing the seat belt is obtained. As shown in the figure, the front end 15a of the spool shaft 15 passes through the boss 110a of the high reduction ratio face gear 110 housed in the casing 11, and reaches the inner peripheral end of a return spring (not shown) (see FIG. 5). It is fixed. The face gear 110 is a large diameter gear having a predetermined conical pitch surface. On the other hand, the electric motor 112 is accommodated in the casing 11 so as to form a staggered shaft in which the spool shaft 15 and the rotation shaft thereof are orthogonal or have a predetermined inclination angle. A drive gear 114 that meshes with the face gear 110 is attached to the rotating shaft end of the electric motor 112. The rotation of the electric motor 112 is decelerated and transmitted to the face gear 110, and the spool shaft 15 is rotated at a low speed. The electric motor 112 is driven when the occupant is wearing the seat belt, and thereby the webbing (not shown) that has been pulled out excessively when the seat belt is worn is pulled into the occupant's chest to the extent that there is no pressure, Can be lightly fitted. Winding of the webbing during traveling is performed by the above-described return spring or the like. Thus, by omitting the winding function with a large reduction ratio, a low-priced and small-sized winding device can be provided.

[Configuration of the entire device that functions around the control unit]
FIG. 7 shows a schematic configuration of each mechanism of the seat belt retractor described above, various control units for linking these mechanisms to operate them, various detection units that send necessary drive signals to the control unit, and detection sensors. Indicated. FIG. 7 shows the above-described winding device 1, the control unit 9 outside the device for giving a predetermined operation command to each mechanism housed in the winding device 1 as shown in FIGS. An occupant seat belt wearing state and a vehicle safety state during traveling , that is, an external signal sensor that transmits a traveling state signal, which are sent to the unit 9 are schematically shown. That is, the take-up device 1 is disposed axially supported by the spool 2 to the base frame 3 via a spool shaft 1 5, the webbing W is adapted to be wound around the spool 2. The winding operation of the spool 2 includes the first reduction mechanism 10A and the second reduction mechanism 10B as two transmission paths having different reduction ratios of the rotational torque of the motor 5, and the drive signal from the control unit 9 as the transmission path. And a resistance torque means provided on the path so as to pass through one of the first speed reduction mechanism 10A and the second speed reduction mechanism 10B depending on the magnitude of the transmitted rotational torque. 60, a webbing drawer detection unit 40 that detects rotation of the spool 2 by driving the motor or pulling out the webbing W, and a spool rotation detection unit 50. A part of the vehicle is equipped with a control unit 9 that outputs a drive signal to the motor 5 of the winding device 1. This control unit 9 is incorporated in a buckle 7 to which a webbing drawer detection unit 40, a spool rotation detection unit 50, and a webbing tongue are mounted via an input I / F (not shown). A buckle switch 8 that informs that the vehicle is worn and a plurality of external signal sensors S1,... Sn that inform various vehicle conditions when traveling are connected to the vehicle. A driving state signal obtained in various states at the time is input. On the basis of these input signals, the control unit 9 performs ON / OFF control of the CPU power source and the motor drive power source, and also generates drive signals such as a motor rotation control signal and a switching signal for switching the speed reduction mechanism. The motor drive control is performed by the drive signal.

[Configuration and operation of webbing drawer detection unit and spool rotation detection unit]
Next, the configuration of the webbing drawer detection unit 40 and the spool rotation detection unit 50 will be described with reference to FIG. FIG. 8 schematically shows the detection unit in a state where the side surfaces of the seat belt retractor 1 to which the detection units are attached are opposed to each other. As shown in the left half of FIG. 8, the webbing drawer detection unit 40 includes a fan-shaped switch plate 41, a rotation pin 42 that pivotally supports the switch plate 41 at a required position, and a short arm length from the rotation pin 42. And a limit switch 44 whose contact is turned on / off by the rotation of the contact arm 43. As shown in FIG. 3 (FIG. 4), the switch plate 41 is provided with guides 41a at both ends, and its rotation range (angle) is restricted. In this range, the arc-shaped edge 41b is in contact with the ring-shaped groove 21 at the end of the spool shaft input gear 20 described above. The arc-shaped edge 41 b is formed with an arc groove 41 c on the inner side along the edge. When the arc-shaped edge 41 b comes into contact with the ring-shaped groove 21, the arc-shaped edge 41 b bends slightly and is given a pressing force. Accordingly, the switch plate 41 can be rotated without slipping. In the figure, as the switch plate 41 (two-dot chain line) in the initial position rotates in the CW direction of the spool 2 (corresponding to the pulling out of the webbing W), the switch plate 41 rotates around the fulcrum in the CCW direction. The ON state of the limit switch 44 is shown.

  The operation when the limit switch 44 of the webbing drawer detection unit 40 is turned on will be described. In the normal case, when the motor drive is realized by the operation of the CPU as in the present apparatus, the ON operation of the ignition key of the passenger car can be considered as a trigger for turning on the CPU power supply Pw. However, in this apparatus, it is most efficient to turn on the CPU power supply Pw when an operation of pulling out webbing is performed, which leads to downsizing of the apparatus. Therefore, the webbing drawer detection unit 40 detects the timing at which the CPU power supply Pw is turned on at the moment when the webbing is pulled out.

  On the other hand, a spool rotation detection unit 50 is provided outside the reel lock mechanism 4. The spool rotation detection unit 50 can detect the rotation direction of the spool 2, that is, the detection of the webbing W withdrawing or the winding direction of the webbing W and the stop state. As shown in FIGS. 1 and 8, the spool rotation detection unit 50 includes a gear 51 attached to the end of the spool shaft 15 that rotates coaxially with the spool 2, and three sheets that reduce the rotation obtained from the gear 51. It comprises a gear train 52 and a variable resistor 53 that detects the finally decelerated rotation angle as a resistance change amount. The rotation state of the spool 2 can be detected by detecting a change in the voltage obtained via the variable resistor 53.

  The actual operation of the webbing drawer detection unit 40 will be briefly described. When the webbing W is being wound by the normal driving of the motor 5, if the occupant prevents the webbing W from being wound or pulls out the webbing W, the switch plate 41 is slightly rotated, and the limit switch 44 is turned on. Turns on. Since the motor drive is stopped by this trigger, the occupant can thereafter pull out the webbing W lightly from the winding device 1. When the webbing drawer detection unit 40 or the spool rotation detection unit 50 detects the webbing W withdrawal, the motor driving is stopped. When the drawing of the webbing W is stopped, the motor 5 is turned on and the winding of the webbing W is resumed.

  As described above, both the webbing drawer detection unit 40 and the spool rotation detection unit 50 can detect the rotation of the spool 2 and use it as a trigger to be incorporated into the circuit. For example, as shown in FIG. 8, the CPU power supply Pw may be turned ON depending on the OR state of both detection units.

[Configuration and operation of claw mechanism]
Two typical examples of the claw mechanism 70 to be engaged with the ratchet teeth 36 formed on the outer periphery of the internal gear 34 of the planetary gear unit 30 will be described, and a modification thereof will be briefly described. .
(First Configuration Example) The configuration and operation of the claw mechanism 70 as a first configuration example will be described with reference to FIGS. The claw mechanism 70 includes a solenoid 71 held on the inner surface of the casing 11 and a lever stopper 75 having a rotating structure. As shown in FIG. 9A, the solenoid 71 has a plunger 72 that slides within the coil when excited. The solenoid 71 slides so as to be drawn into the coil in the energized state (excited state) and to be pulled out to the initial state by the spring 73 in the state where the excitation is released.

  In the vicinity of the plunger 72, a lever stopper 75 supported by a rotating shaft is disposed. This lever stopper 75 has a shape in which a main driving lever 76 and a driven lever 77 are integrally formed at a predetermined angle with respect to the rotating shaft on a disc portion 75a concentric with the rotating shaft. Of these, as shown in the figure, the main drive lever 76 has a lever tip 76a extending to the tip of the plunger 72, and is biased toward the tip 72a of the plunger 72 by the spring 73 in the initial state, and the position is maintained. A locking claw 78 is attached in the vicinity of the driven lever 77 so as to be turnable via a rotation shaft formed in the disc portion 75. This locking claw 78 is in an integrated state so as to be pressed against the driven lever 77 by a wire spring 79 that is mounted around the disk portion 75 in the initial state. An escape protrusion 78 a is further formed at the tip of the locking claw 78.

  Here, the engagement of the internal gear 34 to the ratchet teeth 36 by the claw mechanism 70 and the operation at the time of release will be described with reference to FIGS. 9B and 9C. As one mode of various webbing winding modes, there is a rapid winding operation of the webbing W by a large torque. This rapid webbing take-up operation is realized by transmitting the rotational torque of the motor 5 directly to the spool 2 by the reduced rotation of the carrier 33 of the planetary gear 32 via the second reduction mechanism 10B. Therefore, as described above, in the planetary gear unit 30, it is necessary to lock the ratchet teeth 36 formed on the outer periphery of the internal gear 34 with the claw mechanism 70 and lock the rotation of the internal gear 34.

  FIG. 9B shows a state in which the solenoid 71 is energized and the plunger 72 is drawn into the coil of the solenoid 71. Simultaneously with the pulling of the plunger 72, it is pushed by the plunger tip 72a and the main driving lever 76 of the lever stopper 75 rotates in the CCW direction, and accordingly, the engagement with the driven lever 77 projecting from the disk portion 75 is integrated. A part of the pawl 78 is locked to the valley of the ratchet teeth 36 from the rotation direction of the ratchet teeth 36. As a result, the rotation of the internal gear 34 in the CW direction is locked, and the planetary gear 32 meshed with the internal gear 37 revolves while rotating in the CCW direction. Along with this revolution, the carrier 33 can also rotate the spool 2 around the spool shaft 15 with a large reduction ratio.

  The operation of the lever stopper 75 when releasing the lock of the internal gear 34 from this state will be described. When the excitation of the solenoid 71 is released from the state where the rotation of the internal gear 34 is locked, the plunger 72 extends so as to come out of the coil, and the main driving lever 76 of the lever stopper 75 rotates in the CW direction. At the same time, the driven lever 77 also rotates. At this time, the locking claw 78 is in contact with the ratchet teeth 36 with a predetermined pressing force, so that the locking claw 78 and the ratchet teeth 36 are held in a locked state even when the driven lever 77 rotates. When the disk portion 75 is further rotated, the locking claw 78 is rotated toward the driven lever 77 side so as to get over the apex of the ratchet teeth 36 with the root portion of the escape projection 78a as a fulcrum by the restoring force of the wire spring 79. Thereby, the latching with the ratchet teeth 36 is released.

(Second Configuration Example) The configuration and operation of the claw mechanism 170 as a second configuration example will be described with reference to FIGS. 10 and 11. As shown in FIGS. 10 and 11A, the pawl mechanism 170 includes a solenoid 171 held on the inner surface of the retainer plate 120, a lever 175 operable to follow the expansion and contraction of the plunger 72 of the solenoid 171, A first pawl 180 that partially locks the ratchet teeth 36 by the operation of the lever 175, and a second pawl that locks the ratchet teeth 36 at the tip as the first pawl 180 rotates as the first pawl 180 rotates. It is composed of a pawl 182.

  The solenoid 171 has a plunger 172 that slides within the coil when excited. The plunger 172 is drawn into the coil in the energized state (excited state), and slides so as to be pulled out to the initial state by the operation of the release spring 190 and the second pawl when the excitation is released.

  In the vicinity of the tip of the plunger 172, a lever 175 supported by the rotating shaft 184 is disposed. The lever 175 has a shape in which a main driving lever 176 and a driven lever 177 are integrally formed at a predetermined angle on a shaft portion 175 a concentric with the rotating shaft 184. Of these, as shown in the figure, the main drive lever 176 has a bifurcated lever tip 176a engaged with the narrow diameter portion 172a of the plunger 172, and the main drive lever 176 swings following the expansion and contraction of the plunger 172. The entire 175 rotates about the rotation shaft 184.

  A first pawl 180 is disposed on the lower surface of the driven lever 177 so as to be movable along the elongated hole 186 by the urging force of the release spring 190. The long hole 186 has a gentle curvature around the central axis of the spool shaft 15. The first pawl 180 has a substantially arcuate shape and is urged in the A direction along the elongated hole 186 by a release spring 190 connected to the rear end portion. Further, a half of the tip end side of the second pawl 182 supported by the rotating shaft 188 is disposed in a notch portion formed in a part thereof.

  Here, the locking of the internal gear 34 to the ratchet teeth 36 by the claw mechanism 170 and the operation at the time of releasing will be described with reference to FIGS. 11 (b) to 11 (d). Similar to the first configuration example, a rapid winding operation of the webbing W by a large torque will be described as an example. This abrupt webbing take-up operation is realized by transmitting the rotational torque of the motor 5 directly to the spool 2 by the reduced rotation of the carrier 33 of the planetary gear 32 via the second reduction mechanism 10B as described above. Therefore, as described above, in the planetary gear unit 30, it is necessary to lock the ratchet teeth 36 formed on the outer periphery of the internal gear 34 with the claw mechanism 170 and lock the rotation of the internal gear 34.

  FIG. 11B shows a state where the solenoid 171 is energized and the plunger 172 is drawn into the coil of the solenoid 171. Simultaneously with the retraction of the plunger 172, it is pushed by the plunger tip 172b and the main driving lever 176 of the lever 175 rotates in the CCW direction, and the driven lever 177 also rotates around the shaft portion 175a. The first pawl 180 in contact with the lower surface of the first pawl 180 overcomes the biasing force of the release spring 190 and rotates in the CCW direction, and the locking pawl 180a formed on the lower surface of the first pawl 180 rotates the ratchet teeth 36. From the direction, it is locked to the valley of the ratchet teeth 36.

  As shown in FIG. 11 (c), when the internal gear 34 rotates in the CW direction around the rotation shaft 15 (spool shaft) in this state, the rotation shaft so that the entire first pawl 180 compresses the release spring 190. It rotates in the CW direction around the long hole 186 around 15 times. At this time, since the upper surface of the first pawl 180 is restricted by the driven lever 177, the locking is not released. At the same time, a part of the notch 180b of the first pawl 180 presses the tip 182a of the second pawl 182 to rotate the second pawl 182 around the rotation shaft 188 in the CCW direction. As a result, the rotation of the internal gear 34 in the CW direction is locked, and the planetary gear 32 meshed with the internal gear 37 revolves while rotating in the CCW direction. Along with this revolution, the carrier 33 can also rotate the spool 2 around the spool shaft 15 with a large reduction ratio.

  Next, operations of the lever 175, the first pawl 180, and the second pawl 182 when releasing the lock of the internal gear 34 will be described with reference to FIG. When the excitation of the solenoid 171 is released from the state in which the rotation of the internal gear 34 is locked, the force for holding the plunger 172 in the coil is lost, and the urging force of the release spring 190 in the extension direction (arrow A direction) The driven lever 177 rotates around the rotation shaft 184 in the CW direction. As a result, the restriction force that presses and locks the first pawl 180 to the ratchet teeth 36 is released, the first pawl 180 rotates in the CCW direction around the rotation shaft 15, and the notch end 180 c protrudes from the second pawl 182. The second pawl 182 is rotated in the CW direction around the rotation shaft 188 in contact with the shaped portion 182b, and the latching between the ratchet teeth 36 of the internal gear 34 and the two pawls 180 and 182 is released, and the inner The tooth gear 34 is completely unlocked.

  According to the second configuration example described above, the pawl and the ratchet teeth can be obtained by the two pawls that operate using the biasing force of the release spring without rotating the motor in reverse, particularly when unlocking. Can be easily unlocked.

  (Modified Example of Claw Mechanism) Next, a modified example of the claw mechanism 70 as the first structural example will be briefly described. FIG. 12A shows a modification in which the driven lever 77 is directly engaged with the ratchet teeth 36. In this claw mechanism 70, the roller R is attached to the tip of the driven lever 77, and when the plunger 72 extends and the main driving lever 76 and the driven lever 77 rotate integrally in the CW direction, the roller R rotates. Friction between the ratchet teeth 36 and the lever tip is reduced, and the lever tip is easily detached from the ratchet teeth 36.

  FIG. 12B shows an example in which an arm-shaped stopper 92 is attached to the output shaft of the geared motor 91 and the stopper 92 (claw) is rotated by driving the geared motor 91. In FIG. 12 (c), the rack 90 a is brought into contact with the ratchet teeth 36 using the rack and pinion mechanism 90 with respect to the geared motor 91. In the case of FIGS. 12B and 12C, since the stopper is brought into contact with the gear drive, the stopper can be surely cut off.

[Driving force transmission between speed reduction mechanism and sliding mechanism]
Next, the transmission path of the rotational driving force in the first reduction mechanism 10A and the second reduction mechanism 10B realized by the above-described mechanisms and the operation of the sliding mechanism 60 will be described with reference to FIGS. In the DC motor 5 of the present embodiment, the number of rotations is open-loop controlled according to the drive pulse signal output from the drive circuit, but in the present embodiment, the number of rotations of the motor 5 is set to a three-stage duty ratio. The control circuit is designed so that the webbing is wound with a rotational torque of (25, 50, 100%) weak, medium and strong. The relationship between the actual use state and the webbing take-up setting will be described later. First, the operation of each transmission element in the transmission path when the rotation of the motor 5 is transmitted to the spool shaft 15 with a small torque via the first reduction mechanism 10A and the webbing W is wound will be described. As shown in FIG. 13A, when the motor 5 rotates at a low speed in the CCW direction for webbing winding, the reduction gear 13 rotates at a low speed via the gear 12. At this time, since the rotational torque of the reduction gear 13 is equal to or less than the set torque of the rotor shaft 18 of the rotary damper 17 attached to the recess 13 a, the spool shaft input gear 20 does not rotate relative to the reduction gear 13 and the reduction gear 13. And the rotational torque of the reduction gear 13 is applied as it is as the winding rotational force of the spool 2. At this time, as the spool 2 rotates, the carrier 33 of the planetary gear unit 30 that is integrally fitted to the spool 2, the sun gear 31 that is loosely fitted to the protruding shaft 15 a of the spool shaft 15, and the internal gear 34 are Rotate integrally with the spool 2 in the CCW direction without rotating relative to each other (see FIG. 14A).

[Configuration and operation of transfer element]
Next, the operation of each transmission element in the transmission path when the rotation of the motor 5 is transmitted to the spool shaft 15 via the second reduction mechanism 10B that generates a large torque and the webbing W is rapidly wound up will be described. To do. As shown in FIG. 13 (b), when the motor 5 rotates at a high speed at the rotational speed set in the CCW direction for webbing winding, the reduction gear 13 rotates at a predetermined reduction ratio via the gear 12. . On the other hand, the sun gear 31 of the planetary gear unit 30 shown in FIG. 14B rotates the same number as the reduction gear 13. At this time, since the pawl mechanism 70 is engaged with the ratchet teeth 36 formed on the outer periphery of the internal gear 34, the rotation of the internal gear 34 is locked. Therefore, the planetary gear 32 and the carrier 33 supporting the planetary gear 32 revolve in the CCW direction while meshing with the internal teeth 37 of the locked internal gear 34 as the sun gear 31 rotates. As the carrier 33 rotates, a large rotational torque is applied to the enlarged diameter portion of the spool shaft 15 fitted in the socket portion 35.

  At this time, since the rotational torque of the reduction gear 13 exceeds the set torque of the rotor shaft 18 of the rotary damper 17 provided as the sliding mechanism 60, the gear 19 of the rotary damper 17 meshing with the spool shaft input gear 20 receives viscous resistance. Rotate while braking. Since the input from the reduction gear 13 side is blocked by the slip mechanism 60 in this way, slip occurs on the first reduction mechanism 10A side, and the transmission path of the first reduction mechanism 10A and the transmission path of the second reduction mechanism 10B are changed. Direct connection is avoided (see FIG. 13B).

[Operation of sliding mechanism]
Further, a typical state in which the sliding mechanism 60 operates will be described with reference to FIG. When the motor 5 rotates at a low speed and the occupant holds the webbing W while the webbing W is being wound up to prevent or pull the webbing W, the spool shaft input gear 20 stops or rotates in the CW direction. At this time, the motor 5 is rotating in the CCW direction. When the reduction gear 13 is prevented from rotating in the CCW direction, a load is applied in the reverse direction, and at that moment, the torque exceeds the set torque of the rotor shaft 18 of the rotary damper 17. The spool shaft input gear 20 rotates in the direction opposite to the motor rotation direction, and slip occurs between the gears 19 of the rotor shaft 18. Further, since the pull-out detection unit 40 detects that the webbing W has been pulled out, the rotation of the motor 5 stops. Accordingly, the occupant can easily pull out the webbing W.

[Operation flow when using the entire device]
The motor drive mode in the control method of the seat belt retractor configured as described above will be described with reference to the operation flowcharts of FIGS. 16 to 18 and the respective changes in the webbing retract state of FIGS. 19 and 20. FIG. 16 is a flowchart showing an operation flow in the webbing take-up control. FIG. 17 is a flowchart showing a processing operation flow in various setting modes. FIG. 18 is a flowchart showing an operation flow for improving comfort when the belt is worn.

  As described above, the rotational speed of the DC motor 5 used in the seat belt retractor 1 can be set in detail by voltage setting or pulse signal setting in the control circuit. Therefore, fine seat belt retracting operation is realized by setting various operations when the occupant wears the seat belt and webbing retracting operation modes corresponding to various signals received from the outside during traveling. be able to.

  The operation in each mode corresponding to the state signal obtained during a series of operation states from when the occupant wears the seat belt when getting on to when the seat belt is dismounted when getting off, and the external signal obtained when traveling Will be described in relation to the motor speed setting.

(1) When getting on and off (Comfort mode)
Usually, the occupant pulls out the seat belt stored in the pillar or the like at the same time as sitting on the seat and attaches the tongue to the buckle on the opposite side of the seat. At this time, the webbing W drawer is detected by the webbing drawer detection unit 40 of the winding device 1, and the circuit and CPU power supply Pw are turned on (steps 100 and 110). Instead of the seat belt handling operation, the power may be turned on by an external signal generated by operating an ignition key or the like. The motor 5 stops rotating and the webbing take-up is stopped by the state signal that has detected webbing withdrawal (steps 120 and 130). After that, when the tongue is properly attached to the buckle and the buckle switch 8 (see FIG. 7) built in the buckle 7 is turned ON, the motor is used to remove the slack of the webbing W that has been pulled out and fit the belt. 5 rotates at medium speed, and the webbing W is wound up. As a result, the webbing W is stretched over from the chest to the abdomen of the occupant so that there is no feeling of pressure. As a result, the slug of the belt can be taken and lightly fitted to the occupant's body shape (step 150). Based on the status signal informing that the belt fit is completed, the motor torque can be further reduced, or the motor drive can be stopped to remove the feeling of pressure due to the belt mounting. When the occupant tilts his / her body greatly forward from this state, the webbing is pulled out following the movement, and the webbing is wound up again by the same operation from the time when the drawing is stopped. If a state signal indicating that the webbing W drawing is interrupted is detected, the webbing W is wound up with a predetermined driving torque value and stored in the winding device 1 (steps 125 and 145).

  If the occupant takes a forward leaning posture with the tongue mounted on the buckle, the webbing will be pulled out further. At this time, the operation of the motor 5 is stopped, and when the webbing pull-out is interrupted while the forward tilting posture is stopped, the motor is driven again and the webbing winding is resumed. Thereafter, after the belt is fitted, the driving torque value of the motor can be reduced or the motor driving can be stopped.

  Further, when the passenger gets out of the car, the webbing W needs to be wound at a moderate speed with the tongue removed, and stored in a predetermined amount in the pillar or the like. Thereafter, when it is confirmed that there is no pulling-out operation for a certain time, the CPU power supply Pw is turned off from the circuit side (steps 170 to 195).

In this way, the comfort when the occupant wears the seat belt can be enhanced. Furthermore, in order to improve the comfort when the seat belt is worn, it is preferable to perform control so as to specifically perform the following operation. This will be described below with reference to FIGS.
(a) (Prevents loosening when wearing a belt)
Conventionally, even if the seat is lowered with a seat slide or the like after the seat belt is mounted, the withdrawal of the seat belt is not detected. In view of this, the seat belt retracting operation is repeatedly performed at predetermined time intervals when the seat belt is worn, so that the seat belt is not loosened when the seat belt is worn. Specifically, as shown in FIG. 18, when the withdrawal of the seat belt is detected, a predetermined take-up is performed (steps 300 and 310), but after the withdrawal and the take-up of the seat belt are further completed. When a certain period of time has elapsed (steps 320 and 330), the winding operation is started again (step 310), the winding state is judged (step 340), and after the winding is completed (step 350), a predetermined time is again obtained. The detection loop was activated at time intervals. Thereby, the belt slack at the time of wearing the seat belt can be surely eliminated.

(b) (Reduction of discomfort when shifting from belt withdrawal to winding when the belt is worn)
In the present invention, the motor can be wound when the belt is fitted. In this case, by adjusting the motor driving speed, it is possible to relieve the feeling of pressure applied to the chest of the occupant when the belt is worn. Specifically, as shown in FIG. 20, it is possible to cope with this by making the motor speed variable. The motor speed can be controlled by well-known motor speed control such as PWM driving or adjusting the driving voltage. It can be performed at a predetermined interval (for example, every minute). Further, when performing such motor speed control, as shown in the speed state change diagram shown in FIG. 20, in order to facilitate the pulling out of the seat belt when the buckle is not yet worn, The motor is stopped to reduce the seat belt tension. On the other hand, since it is desirable that the winding immediately after the buckle is mounted, the motor speed is raised as usual.

(2) (During driving)
During traveling, a driving state signal is mainly detected, and a driving pulse signal corresponding to the signal is generated to drive the motor. The following mode settings are possible depending on the urgency level during travel.
(c) (Warning mode)
For example, the main purpose is to alert the driver of the situation in a case where the inter-vehicle distance is closer than the set distance by the inter-vehicle detection sensor of the front and rear vehicles during traveling. The inter-vehicle distance can be set in various ways according to the vehicle speed, etc., but when there is an obstacle that falls within a certain inter-vehicle distance, the webbing is taken up and the driver is in the presence of the object To experience. At this time, if you use the speed of the vehicle, the relative speed with the object, the rate of change, etc. as factors, and if you approach the object such as a wall by your own operation, such as in a garage, do not enter warning mode Can also be considered.
(d) (Hold mode)
A mode to hold the occupant's body by involving the webbing. For example, a seatbelt that is more urgent than the warning mode described above, or that the driver falls asleep during driving and falls forward This function functions as a warning to correct the driver's posture and to wake up the driver even when the driver is pulled out, or when the dozing detection sensor realized by the existing technology detects dozing. In addition, a webbing take-up operation signal can be generated for safety by holding a driver or a passenger on a seat on a sharp curve or on a rough road. As an external signal generation trigger in this case, an ABS operation signal, a signal from a steering angle sensor, a road surface sensor, or the like can be used.
(e) (Pretension mode)
Conventionally, there is a pretensioner that can roll up a predetermined amount of webbing when a collision or sudden deceleration is detected to enhance the occupant's restraining effect. However, information that prevents collision avoidance by an inter-vehicle distance detection sensor such as a laser radar can be obtained. In such a case, the webbing is rapidly engulfed by driving the motor so that the restraint protection of the occupant can be performed prior to the collision. It is possible to set a winding speed or the like so that the occupant is not injured during rapid winding, and secondary injury can be prevented.

(3) (When the child seat is fixed)
Child seats are usually fixed to the seat using webbing. At this time, in the conventional seat belt retractor, it is necessary to fix the child seat to the seat in a state where the entire amount for preventing loosening of the webbing is pulled out during traveling. Therefore, it is preferable to set a dedicated mode for fixing the child seat to the seat. For example, a child seat switch is provided, and when this switch is ON, the webbing is tightly wound until the child seat can be fixed to the seat with a relatively large torque.

  FIG. 17 is an operation flowchart showing a processing procedure corresponding to each mode described above. When a signal suitable for each mode is input from the external signal to the control circuit during traveling or when the child seat is fixed, the webbing winding speed and winding time corresponding to each mode are set (steps 310, 320, and 330). Thereafter, in order to switch the speed reduction mechanism 10, the speed reduction mechanism switching is turned on (the solenoid energization of the claw mechanism 70) so that the motor drive is transmitted to the spool 2 via the second speed reduction mechanism 10B described above (step). 340). The webbing W is taken up in a predetermined mode (step 350). When a release signal for the mode or a signal for which safety has been confirmed is input, the deceleration mechanism is switched OFF (step 370). When the child seat is fixed when the child seat is fixed, the reduction mechanism switching is turned on and the webbing W is wound up for a predetermined time (steps 400 to 420). Further, when removing the child seat, the buckle switch is turned off (step 430) when the tongue is removed from the buckle, and after returning to the comfort mode through the reduction mechanism switching off (step 370), the webbing is gently wound up.

  In each of the modes described above, the motor drive signal is set to obtain a moderate rotational torque in the hold mode and warning mode, and in the pretension mode, the rotational speed is set to obtain a strong rotational torque. It is preferable to do.

  FIG. 19 shows the state signal current for driving the motor for winding the webbing measured to feed back the above state to the control, the webbing feed amount at that time, and the tension for winding the webbing on the winding device. It is a webbing winding state change figure showing typically the relation with the size of. In the figure, the horizontal axis indicates the elapsed time axis (t), which is shown on a schematic scale to the extent that the relative relationship of the passage of time such as the occupant's movement and running state can be confirmed. In each change curve, the signal current indicates the motor driving state, and the feeding amount indicates the webbing movement fed from the winding device. The tension indicates the state of the webbing pull-out force by the occupant and the winding force by the motor drive. As is clear from the figure, the webbing tension can be adjusted to an appropriate value by controlling the motor drive in accordance with the state of the webbing fed from the winding device.

[Modification of each component]
(Modification of deceleration mechanism)
Next, a modified example of the overall structure and each speed reduction mechanism 10 described above will be described. FIG. 21A to FIG. 21E are schematic explanatory views showing modified examples of the overall structure of the speed reduction mechanism 10. In FIG. 21A, the first reduction mechanism 10 </ b> A and the second reduction mechanism 10 </ b> B are provided independently, and the transmission of the rotational torque from the motor 5 is switched by switching the transmission gear 70. The movement of the transmission gear 70 can be realized by sliding the gear shaft as illustrated or moving it in the axial direction. In this case, since the slip mechanism 60 is not interposed in the second reduction mechanism 10B, large torque rotation can be output efficiently. Furthermore, as shown in FIG. 21B, the connection of the motor 5 can be switched between the sliding mechanism 60 side and the second reduction mechanism 10B side by the operation of the solenoid 71 instead of the switching gear. FIG. 21C shows a modification in which the switching gear 70 is disposed between the second reduction mechanism 10B and the sliding mechanism 60 in place of the above-described embodiment. Further, as shown in FIG. 21 (d), the motor drive is directly switched between the first reduction mechanism 10A and the second reduction mechanism 10B, and the operation of the solenoid 71 between the spool 2 and the sliding mechanism 60 is performed. It can also be connected and disconnected. FIG. 21 (e) is a modified example composed of a single transmission path that transmits the rotational torque of the motor 5 to the spool 2 via the first speed reduction mechanism 10 </ b> A and the sliding mechanism 60. In this apparatus, the operability in the comfort mode described above is emphasized, and it is preferable to load a large torque webbing take-up operation in an emergency in other urging means.

  Each drawing in FIG. 22 is a schematic explanatory view showing a modification of the first reduction mechanism 10A. Basically, the rotational torque from the motor rotation shaft is surely transmitted to the output shaft 25 such as a webbing take-up shaft, and the pulley 6P is connected to the motor output shaft instead of the structure shown in the present embodiment. The motor drive is transmitted to the drive of the output shaft 25 such as a speed reduction mechanism via the transmission belt 22. (See FIG. 22 (a)). As the transmission belt 22, various cross-sectional (V, flat) belts, resin wires, steel wires, chains, and the like can be employed in addition to the timing belt.

  The planetary gear unit 23 can also be used as a speed reduction mechanism from the motor. In that case, the planetary gear side (carrier 23a) supporting the planetary gear or the internal teeth of the internal gear 23b can be used as the input shaft, and the torque can be transmitted to the output shaft 25 (FIGS. 22B and 22C). )reference).

  A transmission mechanism for switching from the first reduction mechanism to the second reduction mechanism that obtains large torque will be described. FIG. 23A shows a modification in which the carrier 23a of the planetary gear 23 is locked and the input from the sun gear is output to the output shaft 25 from the internal teeth of the internal gear 23b. In FIGS. 23B and 23C, transmission from the input shaft 24 arranged coaxially to the output shaft 25 is realized by the intermediate gear 26. At this time, the intermediate gear 26 can be connected and disconnected by operating the clutch. In an arrangement in which the input shaft 24 and the output shaft 25 are different, a gear train via the intermediate gear 26 may be configured.

  24A and 24B, a flange 93 having the same diameter as that of the internal gear 34 is disposed in the vicinity of the internal gear 34, and an electromagnetic coil 94 is wound around the flange 93 as a guide. A configuration example of the magnetic powder clutch in which the magnetic powder 95 is filled in the gap with the flange 93 is shown. In this magnetic powder clutch, the coil 94 is energized to energize, the magnetic powder 95 filled in the gap is solidified, and the rotation of the internal gear 34 can be locked. 24A shows an example in which the magnetic powder clutch is arranged along the side surface of the internal gear 34, and FIG. 24B shows an example in which the magnetic powder clutch is arranged along the outer peripheral surface of the internal gear 34. Is shown.

(Modification of sliding mechanism)
Next, a modified example of the sliding mechanism 60 will be described. In the present embodiment, the sliding mechanism 60 using the rotary damper 17 is employed, but various modifications using a friction mechanism and a spring biasing mechanism can be given as the torque limiter. FIG. 25A shows a sliding mechanism 60 that prevents the disk from rotating below a certain torque by a leaf spring 63. Since the sliding force is added by pressing the flange 62a of the outer disk 62 with the braking pad 64 attached to the tip of the leaf spring 63 attached to the flange of the inner disk 61, the torque of the outer disk 62 is more than a certain level. The inner and outer discs 61 and 62 rotate together until they become. FIG. 25B is a modification in which a ring-shaped vane 66 is provided on the outer periphery of the inner disk 61 and this vane 66 is concentrically assembled with an outer disk 62 having a ring-shaped oil chamber 65 in which silicon oil or the like is sealed. . Also in this case, the inner and outer disks 61 and 62 rotate integrally until the viscosity resistance of the vane and the surrounding oil exceeds a certain value.

  Furthermore, as shown in FIG. 25 (c), various sliding mechanisms 60 are configured in an outer ring shape, and a predetermined spring torque 67 is attached to the inner space of the sliding mechanism 60 by attaching a spiral spring 67. The rotational torque due to the spring bias is transmitted to the outer ring 62 until the torque exceeds, but the slip mechanism 60 functions when the constant torque is exceeded, and the slip mechanism 60 can be realized in which the rotational torque due to the spring bias is interrupted. As shown in FIG. 25D, instead of the spiral spring 67, a predetermined coil compression spring 67C may be incorporated so that the urging force can be exerted according to a predetermined rotation angle.

  26 is provided between an outer peripheral disc 62 and an inner peripheral bush 61 arranged concentrically with the outer peripheral disc 62. The sliding mechanism 60 shown in FIG. In the sliding mechanism 60 of FIG. 26A, a transition curve portion 62b and a stepped portion 62a corresponding to a ¼ circumference are provided on the inner peripheral edge of the outer peripheral disk 61, and the steel ball 68 has a transition curve 62b. It is accommodated in the terminal part. A part of the inner circumferential bush 61 is provided with a notch in the diametrical direction, and a steel ball 68 is held at the end position of the transition curve portion 62b by a spring S accommodated therein. In this sliding mechanism 60, the steel ball 68 cannot get over the stepped portion 62a below the set torque, and the inner circumferential bush 61 and the outer circumferential disk 62 rotate integrally. When a rotational torque equal to or greater than the set torque is applied, the steel ball 68 is rotated once along the inner peripheral surface of the outer peripheral disk 62 while being pushed by the spring S over the stepped portion 62a, and again from the transition curve portion 62b. Fits at the end position.

  FIG. 26B shows a modification in which a spring S as a torque limiter is mounted between a small-diameter inner circumferential bush 61 and an outer circumferential disk 62. As shown in the figure, the outer peripheral end of the spring S is housed in a recess 62d formed at the inner peripheral position of the outer peripheral disk 62, and the spring is not deformed from the recess 62d due to the bending deformation of the spring below the set torque. . For this reason, the inner peripheral bush 61 and the outer peripheral disk 62 rotate integrally. When the applied rotational torque exceeds the set torque, the outer peripheral end of the spring S makes one rotation while sliding along the inner peripheral surface of the outer peripheral disk 62. Then, the outer peripheral edge is again accommodated in the recess 62d in a state where it has made one round.

  FIG. 26 (c) shows a sliding mechanism 60 similar to FIG. 26 (a). In this sliding mechanism 60, an elastic sphere 69 is used, which is compressed and deformed in the diametrical direction by being pressed by the spring S and is pressed against the inner peripheral surface of the outer peripheral disk 62. When a rotational torque greater than the set torque is generated between the inner circumferential bush 61 and the outer circumferential disk 62, the elastic body ball 69 is sheared and deformed so that the inner circumferential bushing 61 and the outer circumferential disk 62 are integrated and rotated independently. To do.

  FIG. 26 (d) is a modification of FIG. 25 (a). The flange of the outer peripheral disk 62 is sandwiched between two inner peripheral bushes 61a and 61b whose distance can be set by adjusting the screw 61c, and a predetermined resistance torque is applied. A sliding mechanism 60 is shown. If necessary, a spring (not shown) or the like may be interposed in the screw 61c to adjust the pressing force of the inner circumferential bush 61 to the disk.

(Modification of webbing drawer detection unit)
A modification of the webbing drawer detection unit 40 will be described. FIG. 27 is a diagram showing a modification of the switch for detecting webbing withdrawal in place of the fan-shaped switch plate 41 (see FIG. 8). FIG. 27A shows a drawer detection unit 40 including a ring 46 in which a trigger protrusion 46 a is formed and a bush 45 that can rotate relative to the ring 46 with a predetermined sliding resistance. The bush 45 rotates directly in response to the rotation of a spool shaft (not shown). The ring 46 rotates integrally with the bushing 45 when the rotational torque is less than the sliding resistance. The limit switch 44 is turned on by the trigger protrusion 46a. In FIG. 5B, a ring-shaped spring 47 functioning as a fastening ring is fitted over the bush 45, and the bush 45 and the spring 47 are utilized by utilizing friction between the bush 45 and the urging force of the spring 47 that tightens the bush 45. The drawer detection part which turns ON the limit switch 44 in the step which rotates is integrated is shown. Also, instead of the known limit switch used in the present embodiment, a normal contact switch, a photoelectric sensor, a metal that is provided with a slit in a switch plate or ring, and receives light transmitted through the slit by a rotating operation, metal Needless to say, a known sensor switch such as a metal switch proximity plate or a metal sensing proximity sensor that can detect the movement of the ring, or a Hall element that detects a magnetic field change can be used.

(Modification of spool rotation detector)
Next, the spool rotation detection unit will be described. In the spool rotation detection unit, not only the voltage change is directly detected by the variable resistance described above, but also an encoder type photoelectric sensor along this rotation axis and a photoelectric sensor that detects the position of a slit that can also be used for drawer detection, proximity A sensor, a magnetic detection sensor that reads the position by a magnetic head, or the like can be used.

(Other configurations)
In this embodiment, a DC (direct current) motor is used as the motor. However, if it is a variable-speed motor, various known servo motors such as a stepping motor, an ultrasonic motor, an AC motor, and the like are driven by each motor. Needless to say, a circuit can be used, and thereby the above-described winding operation can be realized. In addition, it is preferable that the control board for driving the motor is installed in an empty space under the webbing take-up portion generated when the motor is installed so as to be adjacent to the motor for reasons of wiring of the harness. However, it goes without saying that it may be installed at an appropriate position as long as it can be installed in the frame.

  As shown in the above description, the seat belt can be retracted according to various situations while the occupant is wearing the seat belt, but the setting values of each function are set as standard values at the time of shipment from the factory. ing. Therefore, the occupant can experience various modes in advance (simulate function) and change the degree of the effect according to his / her preference. This operation can be performed, for example, according to the display on the display of the equipped navigation system, or preferably by a dedicated controller.

  In addition to simultaneously generating warning sounds and warning messages in warning mode, pretension mode, etc., user-friendly by generating various sound effects and displaying operation confirmation images in comfort mode. Usability as a simple device can be improved.

  The above setting can be performed by specifying a driver's seat and other seats through a predetermined wire harness wired in the vehicle body, or by making all seats correspond simultaneously. It is also possible to control the mode of each seat via a communication line. For example, the setting mode of the winding device installed in each seat can be arbitrarily set by a driver or a passenger via a communication line based on a known communication protocol in response to a command from the above-described display or remote controller. Can do. The data handled at this time can include a seat identification ID, various mode setting commands (alarm, hold, pause (wait), release, child seat fixation), and the like.

DESCRIPTION OF SYMBOLS 1 Seat belt winding device 2 Spool 3 Base frame 5 Motor 9 Control part 10 Reduction mechanism 10A 1st reduction mechanism 10B 2nd reduction mechanism 13 Reduction gear 15 Spool shaft 17 Rotary damper 20 Spool shaft input shaft 30 Planetary gear unit 31 Sun gear 32 planetary gear 33 carrier 34 internal gear 36 ratchet teeth 40 webbing drawer detection unit 41 switch plate 44 limit switch 50 spool rotation detection unit 52 reduction gear train 60 resistance torque means (sliding mechanism)
70, 170 switching means (claw mechanism)
71,171 Solenoid 76,176 Main drive lever 77,177 Driven lever 78 Locking claw 180 First pawl 182 Second pawl 190 Release spring W Webbing

Claims (19)

A spool that is pivotally supported by a base frame via a spool shaft and webbing is wound around the outer periphery is attached to the end of the spool shaft, and the webbing is performed by a rewinding release force of a return spring that can apply a biasing force to the spool shaft. A seat belt winding device that winds up and switches the winding speed by means of a motor provided with a speed reduction mechanism by means of the switching mechanism of the speed reduction mechanism ,
The reduction mechanism comprises a transmission route which is set to a predetermined reduction ratio, via said transmission path, and a state signal obtained in the occupant of the seat belt mounting operation, detection mounted on the vehicle during running of the vehicle And a motor driving force of a reduction ratio changed by the switching means corresponding to the motor driving signal obtained from a running state signal obtained from the means is transmitted to the spool shaft. Taking device. Depending on the command of the state signal and the running condition signal, performs a switching operation of the path, the sheet of claim 1, wherein by said speed reduction mechanism with a large reduction ratio that to perform the winding of the webbing Belt winding device. The transmission path is switched by the switching means according to a motor drive signal when receiving the state signal and the driving state signal, and the operation of a part of the transmission element provided in the speed reduction mechanism is stopped. The seat belt retractor according to claim 1, wherein the seat belt retractor is configured to be switched at the same time. The switching means has a claw mechanism, and the claw mechanism is engaged with ratchet teeth formed on the outer periphery of the internal gear of the planetary gear unit to fix the rotation of the internal gear. The seat belt retractor according to claim 1. The claw mechanism is characterized in that two pawls supported by a rotating shaft cooperate to lock the ratchet teeth of the internal gear to fix the rotation of the internal gear. The seat belt retractor according to claim 4 . Of the two pawls, the first pawl is rotated about the rotation axis by the excitation of the solenoid, and the second pawl is engaged with the ratchet teeth through the operation of engaging with the ratchet teeth. 6. The seat belt retractor according to claim 5 , wherein the seat belt retractor is configured. 6. The seat according to claim 5 , wherein the biasing spring connected to the first pawl is extended by demagnetization of the solenoid so that the latching of the second pawl to the ratchet teeth is released. Belt winding device. When the occupant's seat belt mounting operation is started, the webbing that was initially wound by the motor rotation receives a state signal that has been pulled out by the occupant, stops the motor rotation, and allows subsequent pulling. receiving a running state signal obtained from the sensing means mounted on the vehicle when the state signal及beauty car both travel of the webbing by the occupant operating, the rotational torque of the motor, the speed reduction ratio corresponding to the condition signal or the running state signal switching, and controls the spool rotation, the control method of the seat belt retractor, characterized in that the webbing was to take up on the spool. The webbing is wound up by driving the motor with a driving torque value that allows the occupant to belt-fit based on a state signal obtained by detecting that the tongue is attached to the buckle. A control method for a seat belt retractor according to claim 8 . Based on the state signal obtained by detecting that the belt fits is completed, according to claim 9, characterized in that the said motor to reduce the driving torque value, or to stop the motor drive Control method for seat belt retractor 9. The seat belt winding according to claim 8 , wherein the winding of the webbing is resumed by driving the motor based on a state signal obtained by detecting that the drawing of the webbing is interrupted. Control method of the take-off device. With the tongue attached to the buckle, the webbing is pulled out, and the winding of the webbing is resumed from the state where the pulling is interrupted. Then, the belt is fitted and then the motor driving torque value is reduced or the motor driving is stopped. The control method for a seat belt retractor according to claim 8 , wherein the control method is performed. The method of the seat belt retractor according to claim 1 2 wherein the drive torque value of the motor in the belt fit operation, characterized in first to tongue is set lower than the value of the belt fit operation when mounted . 9. The apparatus according to claim 8 , wherein the webbing is wound up in a winding device by driving the motor based on a state signal obtained by detecting that the tongue is separated from the buckle. A control method for the seat belt retractor described above. 9. The method of controlling a seat belt retractor according to claim 8 , wherein a power source of a control circuit for driving the motor is turned on simultaneously with detection of the webbing withdrawal or after a predetermined time has elapsed. . Detects that there is no simultaneous or fixed time withdrawal operation is when it is detected that the webbing is completed winding, according to claim 8, characterized in that as the OFF state the power of the control circuit for driving the motor A method for controlling the seat belt retractor according to claim 1. 9. The seat belt winding according to claim 8 , wherein after completion of the webbing winding, it is determined whether the webbing winding is necessary at a certain elapsed time interval, and a winding operation is performed as necessary. Control method of the take-off device. 9. The control method for a seat belt retractor according to claim 8 , wherein the motor-driven webbing retracting speed is variably switched by motor speed control. 8. The resulting switched state signal or the driving torque value of the motor in accordance with a running state signal constant value or the middle variable value, characterized in that to perform the winding of the webbing by the motor drive A method for controlling the seat belt retractor according to claim 1.

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