JP2012218476A - Webbing take-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a webbing take-up device capable of detecting the rotation of a spool in winding or drawing direction at velocity or acceleration of predetermined magnitude from a desired rotation position and capable of changing over operation of various devices etc. based on this detection result.SOLUTION: When a tongue is removed from a buckle and a shaft part 35 is rotated in the winding direction by an energizing force of a spiral spring 36, a rotary plate 172 is rotated in the winding direction, but an inertia rotary disk 182 tends to stay by inertia. Thereby, the inertia rotary disk 182 is rotated to the rotary plate 172 relatively in the drawing direction against the energizing force of a compression coil spring 212, so that a permanent magnet 222 and a Hall element 226 can face each other via a through hole 224 and the Hall element 226 can detect the magnetism of the permanent magnet 222. The detection of the magnetism of the permanent magnet 222 by the Hall element 226 causes a motor 24 to start driving.

Description

  The present invention relates to a webbing retractor that constitutes a seat belt device of a vehicle.

  In the webbing take-up device disclosed in Patent Document 1 below, when the webbing (seat belt) in the spool is fully retracted and the spool is rotated in the pulling direction, the rotation angle detection cam wheel moves in the pulling direction together with the spool. Rotate. The switch lever is in sliding contact with the outer periphery of the rotation angle detection cam wheel, and the protrusion formed on the outer periphery of the rotation angle detection cam wheel reaches the switch lever when the rotation angle detection cam wheel rotates in the pull-out direction. When the protrusion swings the switch lever, the magnet provided on the switch lever approaches the Hall element, and the Hall switch is turned on. Thereby, it can be detected that the webbing is pulled out from the entire storage state.

JP 2007-39011 A

  As described above, in Patent Document 1, it can be detected that the spool has rotated in the pull-out direction from the fully retracted state, but other rotations of the spool, for example, webbing worn on the occupant's body are wound on the spool. The rotation of the spool in the winding direction cannot be detected.

  In consideration of the above fact, the present invention can detect that the spool has rotated at a speed or acceleration of a predetermined magnitude or more from the desired rotational position in the winding direction or the drawing direction, and various devices and the like based on the detection result. An object of the present invention is to obtain a webbing take-up device capable of switching the operation.

  When the webbing take-up device according to the first aspect of the present invention is the webbing take-up device according to the first aspect of the present invention, when the webbing is taken up from the base end side by rotating around the central axis in the take-up direction, the spool and The spool is rotatably provided with the spool, and the spool rotates at a speed or acceleration of a predetermined magnitude or more in the winding direction or a drawing direction opposite to the winding direction. An inertial body that is relatively inertially moved in a predetermined direction, a state before the inertial body is relatively moved with respect to the spool, and a state after the inertial body is relatively moved with respect to the spool. The detected object is detected in any one state, and the detection of the detected object is canceled in any one of the other states, and the detected object and the detected object Detection Detection means for outputting an electric signal of a different level in the extinguished state, and connected directly or indirectly to the detection means, and interposed between a power source and a predetermined device, and output from the detection means Switch means for switching a conduction state between a power source and a predetermined device in accordance with the level of the electrical signal.

  In the webbing take-up device according to the first aspect of the present invention, when the spool rotates in the pull-out direction by pulling out the webbing from the spool, the inertial body also rotates in the pull-out direction, and when the webbing is wound on the spool, the spool When rotating in the winding direction, the inertial body also rotates in the winding direction. However, when the spool rotates in either the winding direction or the drawing direction at a speed or acceleration greater than or equal to a predetermined magnitude, the inertial body moves inertially in a predetermined direction with respect to the spool while rotating together with the spool.

  On the other hand, the webbing take-up device includes a detecting unit, and in any one of a state before the inertial body relatively moves with respect to the spool and a state after the inertial body relatively moves with respect to the spool. A detection object is detected by the detection means, and detection of the detection object by the detection means is canceled in one of the other states. The detection means outputs different levels of electrical signals in a state where the detection target is detected and a state where the detection of the detection target is canceled. The switch means connected directly or indirectly to the detection means switches the conduction state between the power source and the predetermined device by switching the level of the electric signal output from the detection means. Therefore, in this webbing take-up device, when the spool rotates in one of the take-up direction and the pull-out direction at a speed or acceleration of a predetermined size or more, the predetermined device is operated, or the predetermined device Can be stopped.

  A webbing retractor according to a second aspect of the present invention is the webbing retractor according to the first aspect of the present invention, further comprising a biasing unit that biases the inertial body in a direction opposite to the inertial movement.

  In the webbing retractor according to the second aspect of the present invention, the inertial body is urged by the urging means in the direction opposite to the inertial movement with respect to the spool. For this reason, when the rotation of the spool in either the winding direction or the drawing direction is completed, the inertial body is forcibly returned to the state before the inertial movement by the urging force of the urging means. Thereby, the detection state of the detection object in the detection means is switched, and the level of the electric signal output from the detection means is switched. Thereby, the state of a predetermined | prescribed apparatus can be returned to the state before a spool rotates in any one of said.

  A webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the first or second aspect of the present invention, wherein at least the inertial body is in the state before the inertial movement or after the inertial movement. The detected body is provided so that the detected body is positioned at the rotation center of the rotating body interlocking with the rotation of the spool, and the axial direction of the spool and the rotating body in which the detected body is provided The detection means is provided so as to face the detected object along the line.

  In the webbing take-up device according to the third aspect of the present invention, the object to be detected is at the rotation center of the rotating body that is interlocked with the rotation of the spool or the spool at least before or after the inertial body is inertially moved. An object to be detected is provided so as to be positioned. For this reason, at least before the inertial body is moved inertially or after the inertial movement, even if the detected body rotates together with the spool or the rotating body, the position of the detected body does not change, and it is arranged opposite to the detected body. The detected object is continuously detected by the detected means.

  In the present invention, the object to be detected may be provided on the spool or the rotating body. However, the object to be detected provided on the inertial body in a state before the inertial body is inertially moved or after the inertial body is inertially moved is the spool. Or it is good also as a structure located in the rotation center of a rotary body.

  As described above, the webbing take-up device according to the present invention can detect that the spool rotates at a speed or acceleration of a predetermined magnitude or more from the desired rotation position in the take-up direction or the pull-out direction. Based on the result, the operation of various devices can be switched.

It is a front view which shows roughly the whole structure of the webbing winding device concerning a 1st embodiment. It is a disassembled perspective view which shows roughly the structure of the principal part of the webbing winding device concerning a 1st embodiment. It is an enlarged side view which shows the state which the inertial body has not moved inertially. It is an enlarged side view which shows the state which the inertial body moved inertially. It is a circuit diagram which shows roughly the control apparatus of the motor of the webbing winding device concerning a 1st embodiment. It is a front view which shows roughly the whole structure of the webbing winding device concerning a 2nd embodiment. It is a disassembled perspective view which shows roughly the structure of the principal part of the webbing winding device concerning a 2nd embodiment. It is an enlarged side view which shows the state which the inertial body has not moved inertially. It is an enlarged side view which shows the state which the inertial body moved inertially. It is a circuit diagram which shows roughly the control apparatus of the motor of the webbing winding apparatus which concerns on 2nd Embodiment. It is a disassembled perspective view which shows schematically the structure of the principal part of the webbing winding device concerning a 3rd embodiment. It is a circuit diagram which shows roughly the control apparatus of the motor of the webbing winding device concerning a 3rd embodiment.

  Next, each embodiment of the present invention will be described with reference to FIGS. In the following description of each embodiment, the same reference numerals are assigned to parts that are basically the same as those in the previous embodiment, and a detailed description thereof is omitted. To do.

<Configuration of First Embodiment>
(Outline of overall mechanical configuration of webbing take-up device 160)
FIG. 1 is a schematic front view showing the overall configuration of a webbing take-up device 160 according to an embodiment of the present invention.

  As shown in this figure, the webbing retractor 160 includes a frame 12. The frame 12 includes, for example, a plate-like back plate 14 whose thickness direction is along the vehicle width direction and whose width direction is generally along the vehicle front-rear direction. Leg plates 16 and 18 extend from one end in the width direction of the back plate 14 toward one side in the thickness direction of the back plate 14. Each of the leg plates 16 and 18 is formed in a plate shape whose thickness direction is along the width direction of the back plate 14, and a spool 20 is provided between the leg plate 16 and the leg plate 18. The spool 20 has a substantially cylindrical shape whose axial direction is along the opposing direction of the leg plate 16 and the leg plate 18. A longitudinal direction proximal end side of a webbing 22 formed in a long band shape is locked to the spool 20. The webbing 22 is wound around the outer peripheral portion of the spool 20 from the longitudinal base end side, and the tip end side is pulled out from the spool 20 to the upper side of the vehicle.

  On the outside of the above-described leg plate 16 (on the side opposite to the leg plate 18 of the leg plate 16), when the vehicle suddenly decelerates or when the spool 20 suddenly rotates in the winding direction when the spool 20 winds up the webbing 22. A lock mechanism that operates to restrict rotation of the spool 20 in the pulling direction opposite to the winding direction, or a pretensioner that operates when the vehicle suddenly decelerates and forcibly rotates the spool 20 in the winding direction. For example, the end of the spool 20 on the leg plate 16 side is directly attached to the housing of the lock mechanism integrally attached to the leg plate 16 or indirectly through an energy absorbing member called a torsion shaft or the like. It is supported rotatably. In addition, since these lock mechanisms and pretensioner mechanisms are basically known techniques, detailed descriptions thereof are omitted.

  On the other hand, a motor 24 that is an aspect of a “predetermined device” is provided below the spool 20. In the motor 24, the output shaft 26 is oriented in the same direction as the axial direction of the spool 20, and the distal end side of the output shaft 26 passes through the leg plate 16 and is provided outside the leg plate 16 (on the side opposite to the leg plate 18 of the leg plate 16). The inside of the gear case 30 is inserted. Inside the gear case 30, for example, driving force transmission means such as a reduction gear train composed of a plurality of gears is provided. Inside the gear case 30, a shaft portion that is substantially incapable of relative rotation with respect to the spool 20 and protrudes toward the leg plate 16 from the spool 20 passes through the leg plate 16, and the driving force transmitting means described above is inserted. The output shaft 26 and the shaft portion of the motor 24 are mechanically connected via the. As a result, the driving force output from the motor 24 is transmitted to the shaft portion, and further transmitted to the spool 20 via the shaft portion to rotate the spool 20 in the winding direction.

  On the other hand, a spring case 34 is provided on the leg plate 18 outside the leg plate 18 (on the opposite side of the leg plate 18 from the leg plate 16). Inside the gear case 30, a shaft portion 35 that cannot substantially rotate relative to the spool 20 and protrudes toward the leg plate 18 from the spool 20 passes through the leg plate 18 and rotates into the spring case 34. It is supported freely. A spiral spring 36 as an urging means is provided inside the spring case 34. The spiral spring 36 has an end portion on the outer side in the spiral direction directly or indirectly locked with the spring case 34, and an end portion on the inner side in the spiral direction is directly or indirectly locked with the shaft portion 35. Is rotated in the drawing direction, the spiral spring 36 is tightened to urge the shaft portion 35 and thus the spool 20 in the winding direction.

  A rotating plate 172 shown in FIG. 2 is provided inside the gear case 30. As shown in FIG. 2, the rotating plate 172 includes a disc portion 174. The disc portion 174 is formed in a disc shape coaxial with the spool 20. A shaft support portion 176 having a circular outer peripheral shape is formed at the center of the disc portion 174. The shaft support portion 176 is formed coaxially with the disc portion 174 on the opposite side of the disc portion 174 from the spool 20. A fitting hole 178 is formed in the central part of the disc part 174 and the shaft support part 176.

  The fitting hole 178 has a non-circular inner peripheral shape and penetrates the disc portion 174 and the shaft support portion 176. A fitting portion 180 is formed on the spool 20 side of the shaft portion 35 corresponding to the fitting hole 178. The outer peripheral shape of the fitting portion 180 is set to the same shape as the inner peripheral shape of the fitting hole 178, and the fitting portion 180 is fitted into the fitting hole 178, so that the rotating plate 172 has the shaft portion 35, and It is arranged coaxially with respect to the spool 20 in a state in which relative rotation with respect to the spool 20 is basically impossible.

  On the other hand, an inertial rotating plate 182 as an inertial body is provided on the opposite side of the rotating plate 172 from the spool 20. The inertial rotating plate 182 has a disk shape whose outer diameter is smaller than the outer diameter of the disk portion 174. A circular hole 184 is formed coaxially with the inertial rotating plate 182 at the center of the inertial rotating plate 182. The inner diameter dimension of the circular hole 184 is slightly larger than the outer diameter dimension of the shaft support part 176, the shaft support part 176 passes through the circular hole 184, and the shaft support part 176 rotatably supports the inertial rotating plate 182.

  A stopper 192 is formed on the rotating plate 172. The stopper 192 includes a contact wall 194. The abutment wall 194 is formed in a plate shape whose thickness direction is along the rotational circumferential direction of the rotating plate 172, and is on the opposite side of the disc portion 174 via the inertia rotating plate 182 and on the outer periphery of the inertia rotating plate 182. It is provided radially inward from the portion. The stopper 192 includes a connecting piece 196. The connecting piece 196 is formed in a plate shape whose thickness direction is along the rotational circumferential direction of the rotating plate 172. The connecting piece 196 is provided outside the inertial rotating plate 182 in the radial direction. One end of the connecting piece 196 along the axial direction of the disc portion 174 is connected to the disc portion 174, and the other end is connected to the contact wall 194. .

  Furthermore, a spring locking wall 202 is formed on the rotating plate 172 on the side of the drawing direction from the stopper 192. The spring locking wall 202 includes a contact wall 204. The abutment wall 204 is formed in a plate shape whose thickness direction is along the rotational circumferential direction of the rotating plate 172, and is on the opposite side of the disc portion 174 via the inertia rotating plate 182 and on the outer periphery of the inertia rotating plate 182. It is provided radially inward from the portion. The spring locking wall 202 includes a connecting piece 206. The connecting piece 206 is formed in a plate shape whose thickness direction is along the rotational circumferential direction of the rotating plate 172. The connecting piece 206 is provided outside the inertial rotating plate 182 in the radial direction. One end of the connecting piece 206 along the axial direction of the disc portion 174 is connected to the disc portion 174, and the other end is connected to the contact wall 204. .

  On the other hand, a spring locking wall 210 is formed on the surface of the inertial rotating plate 182 opposite to the disc portion 174. The spring locking wall 210 is formed in a plate shape whose thickness direction is along the rotational circumferential direction of the inertial rotating plate 182, and the spring locking wall 210 is located between the stopper 192 and the spring locking wall 202. Yes. A compression coil spring 212 as an urging means is provided between the spring locking wall 210 and the contact wall 204 of the spring locking wall 202. One end of the compression coil spring 212 is pressed against the contact wall 204 of the spring locking wall 202 and the other end is pressed against the spring locking wall 210, and the spring locking wall 210 is brought into contact with the contact wall 194 of the stopper 192. The inertial rotating plate 182 is urged toward the winding direction with respect to the rotating plate 172 until it abuts.

  A rotation restricting wall 214 extends from the end of the abutting wall 204 opposite to the connecting piece 206 (inward in the radial direction of the disk portion 174) toward the winding direction. The tip of the rotation restricting wall 214 (the end on the winding direction side) faces the spring locking wall 210, and the spring locking wall 210 rotates when the inertial rotating plate 182 rotates a predetermined angle toward the pulling direction. Abutting on the tip of the movement regulating wall 214, the relative rotation of the inertial rotating plate 182 with respect to the rotating plate 172 in the further drawing direction is restricted.

  On the other hand, a plurality of permanent magnets 222 each serving as an object to be detected are fixed around the center of the disk part 174 between the shaft support part 176 and the rotation restricting wall 214 along the radial direction in the disk part 174. It is provided at every interval. Corresponding to these permanent magnets 222, a plurality of through holes 224 are formed in the inertial rotating plate 182 around the center of the inertial rotating plate 182 at a predetermined angle. The number of the through holes 224 is the same as the number of the permanent magnets 222. Therefore, the angle formed by the adjacent through holes 224 around the center of the inertial rotating plate 182 is the permanent around the center of the disk portion 174. This is the same as the angle formed by the magnet 222. The formation position of the through hole 224 from the center of the inertial rotating plate 182 along the radial direction of the inertial rotating plate 182 is the arrangement position of the permanent magnet 222 along the radial direction of the disk portion 174 from the center of the disk portion 174. It is the same as.

  Here, as shown in FIGS. 3 and 4, in a state where the spring locking wall 210 formed on the inertial rotating plate 182 is in contact with the contact wall 194 formed on the disc portion 174, the permanent magnet 222 is used. On the other hand, the formation position of the through-hole 224 and the formation position of the spring locking wall 210 are set so that the through-hole 224 is displaced by half the angle formed by the adjacent through-holes 224 around the center of the inertial rotating plate 182. .

  Further, as shown in FIG. 2, the inertia rotating plate 182 rotates relative to the disc portion 174 in the pull-out direction from the state in which the spring locking wall 210 is in contact with the contact wall 194, and the spring locking wall 210. The rotation restricting wall 214 is half of the angle formed by the adjacent through holes 224 around the center of the inertial rotating plate 182 until the rotation angle of the inertia rotating plate 182 contacts with the tip of the rotation restricting wall 214. Is set. For this reason, when the inertial rotating plate 182 rotates relative to the pivot 176 until the spring locking wall 210 comes into contact with the rotation restricting wall 214, the permanent magnet 222 and the through-hole are formed in the axial direction of the rotating plate 172 and the inertial rotating plate 182. 224 is opposed.

  On the other hand, as shown in FIGS. 1 and 2, a Hall element 226 serving as a detection unit is disposed on the opposite side of the inertial rotating plate 182 from the disc portion 174. The hall element 226 is disposed so as to be opposed to the permanent magnet 222 and the through hole 224 in the axial direction of the rotary plate 172 and the inertial rotary plate 182. When the permanent magnet 222 faces the Hall element 226 in a state where the permanent magnet 222 and the through hole 224 face each other, the Hall element 226 detects the magnetism of the permanent magnet 222. However, even if the permanent magnet 222 is opposed to the Hall element 226 in a state where the permanent magnet 222 and the through hole 224 are not opposed to each other, the magnetism of the permanent magnet 222 is blocked by the inertial rotating plate 182, so that the Hall element 226 is permanent. The magnetism of the magnet 222 cannot be detected.

(Configuration of control circuit 240 of webbing take-up device 160)
Next, the configuration of the control circuit 240 for controlling the motor 24 described above will be described.

  As shown in the schematic circuit diagram of FIG. 5, the control circuit 240 includes a relay 82 as a switch means. One end of the switch portion 84 constituting the relay 82 is connected to the motor 24 described above, and the other end is connected to a battery 86 as a power source. The relay 82 is a normally open type in which the movable contact 90 conducts between the motor 24 and the battery 86 while the coil 88 is energized. One end of the coil 88 constituting the relay 82 is connected to the relay control circuit 92 and the other end is grounded.

  The relay control circuit 92 is composed of a transistor, a resistor, or the like (not shown). When the relay control circuit 92 is energized, the coil 88 is energized. The input terminal of this relay control circuit 92 is connected to the collector terminal of a PNP transistor 94. The emitter terminal of the transistor 94 is connected to the output terminal of the output circuit 96 when the switch is off.

  On the other hand, the base terminal of the transistor 94 is connected to the input terminal of the output circuit 96 when switched off. Further, the collector terminal of the NPN transistor 242 is connected between the base terminal of the transistor 94 and the input terminal of the switch-off output circuit 96. The emitter terminal of the transistor 242 is grounded. When the collector terminal and the emitter terminal of the transistor 242 are brought into conduction, the base current flowing between the emitter terminal and the base terminal of the transistor 94 increases, and the transistor 94 Between the emitter terminal and the collector terminal.

  The base terminal of the transistor 242 is connected to the output terminal of the Hall element 226 described above. When the Hall element 226 detects the magnetism of the permanent magnet 222, the base current of the transistor 242 increases, and the collector terminal and emitter terminal of the transistor 242 Conducts between.

  On the other hand, the power input terminal of the switch-off output circuit 96 is connected to one end of the switch unit 104 constituting the relay 102 and is connected to the battery 86 via the switch unit 104, and the relay control circuit described above. The power input terminal 92 is connected between the switch unit 104 and the power input terminal of the switch-off output circuit 96. That is, the relay control circuit 92 and the switch-off output circuit 96 operate when the switch section 104 of the relay 102 is in a conductive state.

  The relay 102 is a normally closed type in which the conductive state of the switch unit 104 by the movable contact 108 is released when the coil 106 is energized, and the coil 106 of the relay 102 is connected to the buckle switch 112. The buckle switch 112 is provided on a buckle to which a tongue provided on the webbing 22 is attached, and an occupant seated on a seat corresponding to the webbing take-up device 160 attaches the webbing 22 to the body and is provided on the webbing 22. When the applied tongue is attached to the buckle, the buckle switch 112 becomes conductive.

  On the other hand, the other end of the first capacitor 122 is connected between the emitter terminal of the transistor 94 and the output terminal of the switch-off output circuit 96 as a power storage means having one end grounded. A state in which conduction between the collector terminal and the emitter terminal of the transistor 242 is released, that is, a circuit extending from the output terminal of the output circuit 96 when switched off to the input terminal of the output circuit 96 when switched off via the transistor 94 Electric charges are stored in the first capacitor 122 in the closed state.

  In addition, the other end of the second capacitor 132 as a power storage means having one end grounded is connected between the collector terminal of the transistor 94 and the input terminal of the relay control circuit 92. The second capacitor 132 is set to have a smaller capacitance than the first capacitor 122. The collector terminal and the emitter terminal of the transistor 242 are brought into conduction, the base terminal of the transistor 94 is grounded, and the transistor 94 is turned on, whereby the charge stored in the first capacitor 122 is released. The discharged electric charge is stored in the second capacitor 132.

<Operation and Effect of First Embodiment>
Next, the operation and effect of the webbing take-up device 160 will be described.

  When an occupant seated on a seat corresponding to the webbing take-up device 160 pulls the webbing 22 to mount the webbing 22, the webbing 22 is pulled out from the spool 20 and the spool 20 rotates in the pull-out direction. As a result, when the shaft portion 35 rotates in the pull-out direction, the spiral spring 36 is tightened. When the occupant hangs the webbing 22 pulled out from the spool 20 on the body and the tongue provided on the webbing 22 is attached to the buckle, the spool 20 is rotated in the winding direction by the urging force of the spiral spring 36. The slack of the webbing 22 hung around the occupant's body is eliminated. As a result, the webbing 22 is put on the occupant's body, and the buckle switch 112 is turned on. The relay control circuit 92 and the switch-off output circuit 96 in the relay 102 and the power input terminals of the switch 86 and the battery 86 are connected. The continuity between them is released.

  On the other hand, for example, when the occupant gets off the vehicle, the continuity in the first capacitor 122 is released when the occupant removes the tongue from the buckle by operating the buckle in order to release the wearing of the webbing 22. As a result, the switch section 104 is turned on by the movable contact 108, the relay control circuit 92 and the switch-off output circuit 96 are supplied with power, and the relay control circuit 92 and the switch-off output circuit 96 are activated.

  In this state, if the collector terminal and the emitter terminal of the transistor 242 are not conductive, a circuit extending from the output terminal of the switch-off output circuit 96 to the input terminal of the switch-off output circuit 96 via the transistor 94 is obtained. The electric charge is stored in the first capacitor 122.

  As described above, when the tongue is pulled out from the buckle, the shaft portion 35 is rotated in the winding direction by the urging force of the spiral spring 36. As the shaft portion 35 rotates in the winding direction, the rotating plate 172 rotates in the winding direction. On the other hand, the inertial rotating plate 182 is rotatably supported by the shaft support portion 176 and can rotate relative to the rotating plate 172. For this reason, even if the rotating plate 172 rotates in the winding direction, the inertial rotating plate 182 tries to stay in inertia.

  As a result, the inertial rotating plate 182 rotates relative to the rotating plate 172 in the drawing direction against the urging force of the compression coil spring 212. In this way, when the inertial rotating plate 182 rotates relative to the rotating plate 172 in the pulling direction until the spring locking wall 210 contacts the tip of the rotation restricting wall 214, as shown in FIG. 222 and the through hole 224 face each other. When the rotating plate 172 and the inertial rotating plate 182 rotate in the winding direction in this state, the permanent magnet 222 and the hall element 226 face each other through the through hole 224 every time the rotating plate 172 and the inertial rotating plate 182 rotate at a certain angle. The Hall element 226 detects the magnetism of the permanent magnet 222. When the base current of the transistor 242 is increased by the Hall element 226 detecting the magnetism of the permanent magnet 222, the collector terminal and the emitter terminal of the transistor 242 are brought into conduction.

  As described above, when the collector terminal and the emitter terminal of the transistor 242 are brought into conduction, the base terminal of the transistor 94 is grounded, so that a larger current than before is generated between the emitter terminal and the base terminal of the transistor 94. The transistor 94 is turned on. As a result, the charge stored in the first capacitor 122 moves to the second capacitor 132, and the charge is stored in the second capacitor 132. The relay control circuit 92 causes a current to flow through the coil 88 by the electric charge stored in the second capacitor 132, and the switch portion 84 is made conductive by the movable contact 90. Accordingly, when the motor 24 is driven, this driving force is transmitted to the spool 20 via the shaft portion 35, and the spool 20 is rotated in the winding direction. Thereby, winding of the webbing 22 by the driving force of the motor 24 is started.

  As described above, when the shaft portion 35 is rotated in the winding direction by the driving force of the motor 24, the rotating plate 172 and the inertial rotating plate 182 are also rotated in the winding direction. Thereby, the facing state of the permanent magnet 222 and the hall element 226 through the through hole 224 is repeated intermittently. Since the facing state of the permanent magnet 222 and the Hall element 226 is intermittently repeated, the charging of the first capacitor 122 and the movement of the charge from the first capacitor 122 to the second capacitor 132 are repeated, and the second capacitor 132 The charge is intermittently stored in the second capacitor 132 before all the charge is released. Thereby, the conduction state of the switch portion 84 of the relay 82, that is, the driving state of the motor 24 is continued, and the webbing 22 is wound around the spool 20.

  When the so-called “all retracted state” in which the webbing 22 cannot be wound around the spool 20 further, the rotation of the shaft portion 35 in the winding direction is stopped and the rotation of the rotating plate 172 in the winding direction is also stopped. When the rotation of the rotating plate 172 in the winding direction stops, the inertial rotating plate 182 rotates in the winding direction until the spring locking wall 210 abuts against the stopper 192 due to the urging force of the compression coil spring 212. Each through hole 224 is displaced in the winding direction with respect to the permanent magnet 222, and the opposed state of the through hole 224 and the permanent magnet 222 is eliminated as shown in FIG. In this state, since the conduction state between the collector terminal and the emitter terminal of the transistor 242 is canceled, the conduction state in the switch unit 84 continues until all the electric charge of the second capacitor 132 is released, and then the switch unit 84. Is released, and the motor 24 stops.

  As described above, in the webbing take-up device 160, the webbing 22 can be taken up and stored by the driving force of the motor 24 from when the occupant releases the wearing of the webbing 22 until it enters the “all retracted state”. The energizing force of the spiral spring 36 may be of a magnitude that can eliminate the slack of the webbing 22 when the webbing 22 is attached to the body of the occupant, and the energizing force of the spiral spring 36 can be reduced. Thereby, the feeling of pressure received from the webbing 22 in a state where the occupant wears the webbing 22 can be reduced.

  Further, in the webbing take-up device 160, as described above, the spool 20 is connected to the spool 20 by a circuit including the first capacitors 122 and 132, the transistor 94, the relay 82, and the like without using expensive components such as a sensor IC. The driving of the motor 24 for retracting the webbing 22 to store the webbing 22 can be controlled, and the cost can be reduced.

<Configuration of Second Embodiment>
(Outline of overall mechanical configuration of webbing take-up device 260)
Next, a second embodiment will be described.

  FIG. 6 is a schematic front view showing the overall configuration of the webbing take-up device 260 according to the present embodiment.

  As shown in this figure, the webbing take-up device 260 is not provided with the rotating plate 172, the inertia rotating plate 182 and the like inside the spring case 34. Further, a case 262 is attached to the spring case 34 on the opposite side of the leg plate 18 of the spring case 34, and a shaft portion 35 rotatably supported by the spring case 34 penetrates the spring case 34 to the inside of the case 262. I'm stuck in. A rotation plate 264 as a rotating body is provided inside the case 262.

  As shown in FIG. 7, the rotating plate 264 is formed in a disk shape that is coaxial with the spool 20 and the shaft portion 35. A disc-shaped or columnar boss 266 is coaxially formed with respect to the rotating plate 264 on the end surface of the rotating plate 264 on the leg plate 18 side. A fitting hole 268 is formed in the rotating plate 264. 0168 has a noncircular inner peripheral shape, and is open at the end surface of the boss 266 opposite to the rotating plate 264.

  A fitting portion 270 is formed at the end of the shaft portion 35 corresponding to the fitting hole 268. The outer peripheral shape of the fitting portion 270 is set to the same shape as the inner peripheral shape of the fitting hole 268, and when the fitting portion 270 is fitted into the fitting hole 268, the rotating plate 264 becomes the shaft portion 35, and consequently, It is arranged coaxially with respect to the spool 20 in a state in which relative rotation with respect to the spool 20 is basically impossible.

  On the other hand, a shaft portion 272 is formed on the surface of the rotating plate 264 opposite to the leg plate 18. The shaft portion 272 has a cylindrical shape whose axial direction is the same as the axial direction of the rotating plate 264, and is formed at a position spaced from the center of the rotating plate 264 outward in the radial direction of the rotating plate 264. A swing plate 274 as an inertial body is provided on the opposite side of the rotary plate 264 from the leg plate 18. The swing plate 274 has a flat plate shape whose thickness direction is along the axial direction of the rotary plate 264. A circular hole 276 is formed on the base end side in the longitudinal direction of the swing plate 274. The circular hole 276 has an inner diameter dimension substantially equal to the inner diameter dimension of the shaft portion 272 (strictly slightly larger), and the swing plate 274 is attached to the rotating plate 264 so that the shaft portion 272 enters the inside of the circular hole 276. As a result, the swing plate 274 is supported so as to be swingable around the shaft portion 272.

  On the other hand, a mounting hole 278 is formed on the leading end side of the swinging plate 274 and on the drawing direction side of the swinging plate 274 in the width direction. A mass body 280 having a predetermined weight is fitted into the mounting hole 278. A mounting hole 282 is formed between the mounting hole 278 and the circular hole 276 (that is, in the middle portion in the longitudinal direction of the swing plate 274). The mounting hole 282 is formed so that the mounting hole 282 faces the rotation center of the rotating plate 264 in a state where the swinging plate 274 reaches a predetermined swinging position around the shaft portion 272. A magnetic plate 284 made of a magnetic material is fitted into the mounting hole 282.

  On the other hand, a stopper 286 is formed on the rotary plate 264 on the winding direction side of the swing plate 274. When the swing plate 274 swings around the shaft portion 272 until the swing plate 274 contacts the stopper 286. As shown in FIG. 8, the entire swing plate 274 is shifted in the winding direction with respect to the rotation center of the rotation plate 264. On the other hand, a stopper 288 is formed on the rotating plate 264 on the drawing direction side of the swing plate 274, and the swing plate 274 swings around the shaft portion 272 until the swing plate 274 comes into contact with the stopper 286. When moved, as shown in FIG. 9, the attachment hole 282, and consequently the magnetic plate 284 fitted in the attachment hole 282, faces the rotation center of the rotation plate 264.

  As shown in FIG. 7, a tension coil spring 290 is provided on the opposite side of the rotating plate 264 from the leg plate 18. One end of the tension coil spring 290 is locked to a locking pin 292 provided on the rotating plate 264 on the winding direction side of the circular hole 276, and the other end of the tension coil spring 290 is formed in the circular hole 276. Locked by the provided locking pin 294, the swinging plate 274 is urged toward the stopper 286.

  Further, a mounting hole 296 is formed in the rotating plate 264. The mounting hole 296 is formed at the center of the rotating plate 264 and opens on the surface of the rotating plate 264 opposite to the leg plate 18. A permanent magnet 298 as an object to be detected is attached to the attachment hole 296. Further, a hall element 300 is provided as a detecting means on the opposite side of the rotary plate 264 from the leg plate 18. The hall element 300 is provided so as to face the permanent magnet 298 along the axial direction of the rotating plate 264, and when the rocking plate 274 is swung until it abuts against the stopper 288, the permanent magnet 298 and the hall element 300 are separated. A magnetic plate 284 is interposed therebetween.

(Configuration of control circuit 310 of webbing take-up device 260)
Next, the configuration of the control circuit 310 for controlling the motor 24 described above will be described.

  As shown in the schematic circuit diagram of FIG. 10, when the control circuit 310 of the present embodiment is compared with the control circuit 240 of the first embodiment, the transistor 94, the switch-off output circuit 96, the capacitor 122, and the like. , And the capacitor 132 is not provided. In the control circuit 310, the emitter terminal of the transistor 242 is not grounded, but is connected to the input terminal of the relay control circuit 92, and the collector terminal is connected to one end of the switch unit 104 constituting the relay 102. The battery 86 is connected via the unit 104.

  The base terminal of the transistor 242 is connected to the output terminal of the inverting amplifier circuit 312. The positive input terminal and the negative input terminal of the inverting amplifier circuit 312 are connected to the output terminal of the Hall element 300, and the negative input terminal of the inverting amplifier circuit 312 and the output terminal of the Hall element 300 are grounded. ing. Therefore, the current flowing through the base terminal of the transistor 242 increases when the Hall element 300 does not detect the magnetism of the permanent magnet 298.

<Operation and Effect of Second Embodiment>
Next, the operation and effect of the webbing take-up device 260 will be described.

  In the webbing take-up device 260, when the occupant operates the buckle to remove the tongue from the buckle in order to release the webbing 22, the shaft portion 35 is rotated in the take-up direction by the urging force of the spiral spring 36. When the shaft portion 35 rotates in the winding direction, the rotating plate 264 rotates in the winding direction, but the swinging plate 274 tries to stay with inertia. As a result, the swing plate 274 swings relative to the rotation plate 264 in the pull-out direction relative to the shaft portion 272 against the urging force of the tension coil spring 290.

  In this way, when the swing plate 274 swings relative to the rotation plate 264 in the pull-out direction until the swing plate 274 contacts the tip of the stopper 288, as shown in FIG. The magnetic plate 284 is interposed between the Hall element 300 and the Hall element 300 so that the Hall element 300 cannot detect the magnetism of the permanent magnet 298. When the level of the electric signal output from the Hall element 300 is decreased because the Hall element 300 cannot detect the magnetism of the permanent magnet 298, the current value of the signal output from the inverting amplifier circuit 312 increases, and the collector of the transistor 242 The terminal and the emitter terminal are brought into conduction, and a current flows through the input terminal of the relay control circuit 92.

  When a current flows through the input terminal of the relay control circuit 92, the relay control circuit 92 causes a current to flow through the coil 88, and the switch portion 84 is made conductive by the movable contact 90. When the switch portion 84 is switched to the conductive state, the motor 24 is driven, and the driving force of the motor 24 is transmitted to the spool 20 via the shaft portion 35 to rotate the spool 20 in the winding direction. Thereby, winding of the webbing 22 by the driving force of the motor 24 is started.

  Thus, when the shaft portion 35 is rotated in the winding direction by the driving force of the motor 24, the rotating plate 264 is also rotated in the winding direction, so that the swing plate 274 is maintained in contact with the stopper 288, A state in which the magnetic plate 284 is interposed between the permanent magnet 298 and the Hall element 300 is maintained. As a result, the state where the movable contact 90 conducts the switch portion 84 is maintained, the driving state of the motor 24 continues, and the webbing 22 is wound around the spool 20.

  When the so-called “all retracted state” in which the webbing 22 cannot be wound on the spool 20 further, the rotation of the shaft portion 35 in the winding direction is stopped and the rotation of the rotating plate 264 in the winding direction is also stopped. When the rotation of the rotating plate 264 in the winding direction stops, the swinging plate 274 rotates in the winding direction until the swinging plate 274 comes into contact with the locking pin 292 by the urging force of the tension coil spring 290. As a result, the swing plate 274 moves from between the permanent magnet 298 and the Hall element 300, and the permanent magnet 298 and the Hall element 300 directly face each other as shown in FIG.

  Since the permanent magnet 298 and the Hall element 300 are directly opposed to each other, the Hall element 300 detects the magnetism of the permanent magnet 298, so that an electrical signal output from the Hall element 300 increases. When the increased electrical signal is input to the inverting amplifier circuit 312, the base current output from the inverting amplifier circuit 312 and input to the base terminal of the transistor 242 decreases. As a result, when the conduction state between the collector terminal and the emitter terminal of the transistor 242 is eliminated, the current flowing through the relay 82 is reduced, the conduction state of the switch unit 84 by the movable contact 90 is eliminated, and the motor 24 is stopped. To do.

  As described above, in the present webbing take-up device 260 as well, in the same manner as in the first embodiment, the driving force of the motor 24 from when the occupant releases the wearing of the webbing 22 until the “all retracted state” is reached. Since the webbing 22 can be wound up and stored, the urging force of the spiral spring 36 may be large enough to eliminate the slack of the webbing 22 when the webbing 22 is attached to the occupant's body. The biasing force can be reduced. Thereby, the feeling of pressure received from the webbing 22 in a state where the occupant wears the webbing 22 can be reduced.

  Further, in the webbing take-up device 260, as described above, the spool 20 is connected to the spool 20 by a circuit including the first capacitors 122 and 132, the transistor 94, the relay 82, and the like without using expensive components such as a sensor IC. The driving of the motor 24 for retracting the webbing 22 to store the webbing 22 can be controlled, and the cost can be reduced.

  Furthermore, the direction of the rotational acceleration of the spool 20 is the same when the spool 20 starts to rotate in the winding direction and when the rotation of the spool 20 in the drawing direction ends. Therefore, for example, in the configuration in which the rotation start of the spool 20 in the winding direction is detected based on the rotational acceleration of the spool 20, when the webbing 22 has been pulled out and the spool 20 has been rotated in the pull-out direction. There is a possibility of erroneous detection when the rotation of the spool 20 in the winding direction is started.

  On the other hand, in this embodiment, when the spool 20 rotates in the winding direction, the rotating plate 264 also rotates in the winding direction so that the swinging plate 274 contacts the stopper 288, and further, the spool 20 While rotating in the direction, the swing plate 274 is maintained in contact with the stopper 288, and the state where the magnetic plate 284 is interposed between the permanent magnet 298 and the Hall element 300 is maintained. For this reason, even if the swinging plate 274 swings when the rotation of the spool 20 in the pull-out direction is completed, the swinging plate 274 is not maintained in contact with the stopper 288. 24 is not driven continuously. Thus, in the present embodiment, the motor 24 can be continuously driven when the spool 20 continues to rotate in the winding direction.

<Configuration of Third Embodiment>
Next, a third embodiment will be described.

(Outline of overall mechanical configuration of webbing take-up device 340)
FIG. 11 shows a configuration of a main part of the webbing take-up device 340 according to the present embodiment, corresponding to the schematic exploded perspective view explaining the second embodiment.

  As shown in this figure, the configuration of the main part of the webbing take-up device 340 is basically the same as that of the webbing take-up device 260 according to the second embodiment. The mounting hole 296 is not formed in the plate 264, and the permanent magnet 298 is not provided. Further, in the present embodiment, the magnetic plate 284 is not provided in the mounting hole 282, and instead, a copper plate 342 that constitutes a detected object as a conductor is fitted. Further, the present embodiment does not include the Hall element 300, but instead is provided with an eddy current sensor 344 as a detecting means.

(Configuration of control circuit 360 of webbing take-up device 340)
Next, the configuration of the control circuit 360 for controlling the motor 24 described above will be described.

  As shown in the schematic circuit diagram of FIG. 12, in the present embodiment, the control circuit 360 is connected to the sensor output circuit 362. The sensor output circuit 362 includes a high frequency AC power source 364. A high-frequency AC power supply 364 is connected to the eddy current sensor 344 via a load such as a resistor 366. As a result, a high-frequency alternating current flows through the eddy current sensor 344, and an alternating magnetic field is generated around the eddy current sensor 344. When the eddy current sensor 344 and the copper plate 342 provided on the swing plate 274 face each other, an eddy current is generated in the copper plate 342 by the alternating magnetic field formed by the eddy current sensor 344. Thereby, the current value of the high-frequency alternating current flowing through the eddy current sensor 344 is reduced by the eddy current loss.

  One end of a rectifying diode 368 is connected between the eddy current sensor 344 and the resistor 366, and the diode 368 is a negative input terminal of the inverting amplifier circuit 312 constituting the sensor output circuit 362 in this embodiment. It is connected to the. One end of a smoothing capacitor 370 is connected between the diode 368 and the negative input terminal of the inverting amplifier circuit 312.

  The other end of the capacitor 370 is grounded. As described above, a high-frequency alternating current flows through the eddy current sensor 344 and a high-frequency alternating current corresponding to the high-frequency alternating current flowing through the eddy current sensor 344 also flows through the diode 368, but is rectified to direct current by the diode 368 and the capacitor 370. And input to the negative input terminal of the inverting amplifier circuit 312. Further, in the present embodiment, the reference potential 372 is connected to the positive input terminal of the inverting amplifier circuit 312 and is grounded via the reference potential 372.

<Operation and Effect of Third Embodiment>
Next, the operation and effect of the webbing take-up device 340 will be described.

  In the webbing take-up device 340, the occupant releases the webbing 22, so that when the tongue is pulled out from the buckle by operating the buckle, the shaft portion 35 is rotated in the take-up direction by the urging force of the spiral spring 36. When the shaft portion 35 rotates in the winding direction, the rotating plate 264 rotates in the winding direction, but the swinging plate 274 tries to stay with inertia. As a result, the swing plate 274 swings relative to the rotation plate 264 in the pull-out direction relative to the shaft portion 272 against the urging force of the tension coil spring 290.

  In this way, when the swing plate 274 swings relative to the rotating plate 264 in the pull-out direction until the swing plate 274 contacts the tip of the stopper 288, the copper plate 342 and the eddy current sensor 344 face each other. . When the copper plate 342 and the eddy current sensor 344 face each other and an eddy current is generated in the copper plate 342, the current value of the high-frequency alternating current flowing through the eddy current sensor 344 is reduced due to the eddy current loss. The current value of the input high-frequency alternating current decreases. When the current value of the high-frequency alternating current input to the diode 368 decreases, the current value of the direct current input to the inverting amplifier circuit 312 decreases, and the current value of the signal output from the inverting amplifier circuit 312 increases. As a result, a drive current flows through the motor 24 as in the second embodiment, and winding of the webbing 22 by the drive force of the motor 24 is started.

  Thus, when the shaft portion 35 is rotated in the winding direction by the driving force of the motor 24, the rotating plate 264 is also rotated in the winding direction, so that the swing plate 274 is maintained in contact with the stopper 288, A state in which the magnetic plate 284 is interposed between the permanent magnet 298 and the Hall element 300 is maintained. As a result, the state where the movable contact 90 conducts the switch portion 84 is maintained, the driving state of the motor 24 continues, and the webbing 22 is wound around the spool 20.

  When the so-called “all retracted state” in which the webbing 22 cannot be wound on the spool 20 further, the rotation of the shaft portion 35 in the winding direction is stopped and the rotation of the rotating plate 264 in the winding direction is also stopped. When the rotation of the rotating plate 264 in the winding direction stops, the swinging plate 274 rotates in the winding direction until the swinging plate 274 comes into contact with the locking pin 292 by the urging force of the tension coil spring 290. Thus, the facing state between the copper plate 342 and the eddy current sensor 344 is eliminated.

  Since the above-described eddy current loss is eliminated by eliminating the opposing state of the copper plate 342 and the eddy current sensor 344, the current value of the high-frequency alternating current flowing through the eddy current sensor 344 increases to the original value. Accordingly, the current value of the high-frequency alternating current input to the diode 368 increases. When the current value of the high-frequency alternating current input to the diode 368 increases, the current value of the direct current input to the inverting amplifier circuit 312 increases, and the current value of the signal output from the inverting amplifier circuit 312 decreases. Thereby, the conduction state of the switch part 84 by the movable contact 90 is canceled as in the second embodiment, and the motor 24 is stopped.

  As described above, the webbing take-up device 340 also has the same effect as that of the second embodiment, and can obtain the same effect as that of the second embodiment.

<Supplementary explanation>
In each of the above embodiments, when the spool 20 is rotated in the winding direction by the urging force of the spiral spring 36, the switch portion 84 of the relay 82 is in a conductive state to drive the motor 24, and the driving force The present invention is applied to the configuration in which the spool 20 is rotated in the winding direction, but the present invention is not limited to such a configuration.

  For example, the present invention can be applied to switching of the tension reducer mechanism. The tension reducer urges the spool 20 in the winding direction with two or more spiral springs connected to each other. When the tongue is attached to the buckle, the tension reducer operates a solenoid to move the end of one or more spiral springs. By restricting the rotation, the urging force of the spiral spring acting on the spool is reduced.

The above Hall element and eddy current sensor detect that the spool has rotated in the pull-out direction,
By controlling the energization control of the tension reducer solenoid as in the above embodiments, the biasing force of the spiral spring can be reduced not only when the webbing is mounted but also when the webbing is pulled out, and the webbing can be easily pulled out. The effect that it is possible can also be obtained.

  In addition, a general webbing take-up device is used when an occupant's body pulls the webbing and rotates the spool in the pull-out direction while the rotation of the spool in the pull-out direction is restricted by the lock mechanism during sudden deceleration of the vehicle. A force limiter mechanism that absorbs energy by inertial movement of the occupant's body forward of the vehicle by deforming energy absorbing means such as a torsion shaft is provided.

  Furthermore, such a force limiter mechanism includes a selectable force limiter mechanism that can switch the amount of energy absorbed by the energy absorbing means based on the weight of the occupant. The present invention may be applied for switching in such a selectable force limiter mechanism.

  That is, regardless of the weight of the occupant or the like, for example, when the spool rotates in the pull-out direction at a speed or acceleration of a predetermined size or more, and such rotation of the spool is detected by the Hall element or the eddy current sensor. May be configured such that the energy absorbing means can absorb the maximum load by operating or not operating the switching device in the selectable force limiter mechanism.

160 Webbing take-up device 20 Spool 22 Webbing 24 Motor (predetermined device)
82 Relay (switch means)
86 Battery (Power)
182 Inertial rotating plate (inertial body)
212 Compression coil spring (biasing means)
222 Permanent magnet (object to be detected)
226 Hall element (detection means)
260 Webbing take-up device 264 Rotating plate (Rotating body)
274 Oscillating plate (inertial body)
298 Permanent magnet (Detected object)
300 Hall element (detection means)
316 Eddy current sensor (detection means)
340 Webbing take-up device 342 Copper plate (detected body)
344 Eddy current sensor (detection means)

Claims (3)

When the webbing is wound from its proximal end side by rotating in the winding direction around the central axis, the spool,
The spool is provided so as to be rotatable together with the spool, and the spool is rotated at a speed or acceleration of a predetermined magnitude or more in the winding direction or a drawing direction opposite to the winding direction. An inertial body that relatively moves inertially in a predetermined direction,
The detected object is detected in any one of a state before the inertial body is relatively moved with respect to the spool and a state after the inertial body is relatively moved with respect to the spool. The detection of the detected object is canceled in the other state of the above, and the detection of outputting an electric signal of a different level between the state where the detected object is detected and the detection of the detected object is canceled Means,
Directly or indirectly connected to the detection means and interposed between the power supply and the predetermined device, and the continuity between the power supply and the predetermined device according to the level of the electrical signal output from the detection means Switch means for switching the state;
A webbing take-up device comprising:   The webbing take-up device according to claim 1, further comprising a biasing unit that biases the inertial body in a direction opposite to the inertial movement.   Providing the detected body so that the detected body is positioned at the rotation center of the rotating body that is interlocked with the rotation of the spool or the spool at least before the inertial body is moved inertially or after the inertial movement; 3. The webbing winding according to claim 1, wherein the detection unit is provided so as to face the detected body along an axial direction of the spool and the rotating body where the detected body is provided. Taking device.

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