JP2006159956A - Webbing take-up device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a webbing take-up device capable of securely taking-up a webbing belt. <P>SOLUTION: In the webbing take-up device, the remaining part for winding of the webbing belt 34 is taken up before the webbing belt 34 becomes a state referred to as "Totally stored", namely, after the taking up of the webbing belt 34 is stopped in a state where the webbing belt 34 is extended by a certain amount, and the door is opened/closed, namely, after the state where it is considered that an occupant gets off. Since the webbing belt 34 is not taken up until it is referred as "Totally stored" in the state where the occupant is onboard like this, it can effectively prevent the arm of the occupant from being taken up by the stored webbing belt 34, and the webbing belt 34 can be stored after it is securely taken up. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a webbing retractor constituting a seat belt device for restraining the body of an occupant seated on a seat of a vehicle or the like with a long belt-like webbing belt, and in particular, the webbing belt is driven by a driving force of a motor or the like. The present invention relates to a webbing take-up device capable of taking up and storing.

  A seat belt device that restrains the body of an occupant seated in a vehicle seat with a long belt-like webbing belt includes a webbing take-up device that is fixed to the vehicle body on the side of the seat. The webbing take-up device includes, for example, a spool (winding shaft) whose axial direction is substantially along the vehicle front-rear direction, and the longitudinal base end side of the webbing belt is locked to the spool. The spool can wind the webbing belt around the outer periphery of the spool, and when the seat belt device is not used, the spool is wound around the outer periphery of the spool.

  Also, this type of webbing take-up device is called a motor retractor or an electric retractor that takes up a webbing belt by rotating a spool with a driving force of a motor, and an example thereof is disclosed in Patent Document 1 below. ing.

  In the motor retractor disclosed in Patent Document 1, the buckle switch detects that the tongue plate provided on the webbing belt has come out of the buckle device, that is, that the webbing belt is not attached to the occupant's body. Then, the seat belt control device closes the contacts between the motor drive circuit and the clutch switching mechanism and the power source. When the contact is closed, the clutch switching mechanism operates a clutch interposed between the motor and the spool to connect the motor and the spool, and the motor driving circuit drives the motor.

As a result, a current flows through the motor for a certain period of time, and the motor is driven for a time required to reach a state called full storage of the webbing belt, for example. When the driving force of the motor is transmitted to the spool via the speed reduction mechanism and the clutch, the spool rotates in the winding direction and winds and stores the webbing belt.
JP 2001-163186 A

  By the way, in the structure disclosed in this Patent Document 1, the motor is driven only for the time required until the entire storage. However, depending on the state of the webbing belt, there is a possibility that the webbing belt cannot be wound even if the driving of the motor is started. Even in such a state, the supply of current to the motor is stopped after a certain period of time. Therefore, in such a case, the webbing belt is not completely wound up and unwinding occurs.

  In view of the above fact, an object of the present invention is to provide a webbing take-up device capable of reliably winding a webbing belt.

  In the webbing take-up device according to the first aspect of the present invention, a spool in which a base end portion of a long belt-like webbing belt is locked is rotated in one winding direction around the axis by the driving force of the driving means. A webbing take-up device for winding the webbing belt around the outer periphery of the spool, the door opening / closing detecting means for detecting the opening / closing of the door of the vehicle and outputting a closing signal when the door is closed; The drive means is stopped by rotating the spool at a predetermined angle or for a predetermined time after the drive means starts driving, and the drive is stopped by driving the drive means to stop the drive means. And control means for resuming driving of the means.

  According to the webbing take-up device of the present invention as set forth in claim 1, an occupant seated on a seat with a long belt-like webbing belt drawn out from a spool hangs around the body and wears the webbing belt. The body is restrained by the webbing belt.

  Further, when the driving means is driven, the spool is rotated in the winding direction which is one side around the spool axis by the driving force of the driving means. By rotating the spool in the winding direction, the webbing belt is wound in layers on the outer peripheral portion of the spool from the longitudinal base end side.

  Therefore, if the driving means is driven when the webbing belt is not attached to the occupant's body, the drawn webbing belt is wound around the spool and stored.

  Here, in the webbing take-up device according to the present invention, when the spool is rotated by a predetermined angle or a predetermined time after the driving unit starts driving as described above, the control unit is configured to wind the webbing belt by a predetermined amount. The driving means is temporarily stopped.

  Next, for example, when the occupant gets off the door, the occupant opens the door, and when the occupant gets off and closes the door, the door open / close detection means outputs a close signal. In this way, when the closing signal output after the driving unit is temporarily stopped is input to the control unit, the control unit resumes driving of the driving unit. By resuming the driving of the driving means, for example, the webbing belt is wound up to a state called full storage.

  As described above, in the present invention, the webbing belt can be more reliably wound and stored.

<Configuration of the present embodiment>
FIG. 1 is a front sectional view schematically showing the overall configuration of a webbing take-up device 10 according to an embodiment of the present invention. FIG. 2 is a front view schematically showing a seat belt device 12 to which the webbing take-up device 10 is applied.

  As shown in FIG. 1, the webbing take-up device 10 includes a frame 20. The frame 20 includes a flat plate 22. The back plate 22 is fixed to the vehicle body by fastening means (not shown) such as a bolt, for example, near the lower end of the center pillar 26 (see FIG. 2) of the vehicle 24. Thus, the webbing take-up device 10 is attached to the vehicle body.

  From both ends in the width direction of the back plate 22, a pair of leg plates 28 and 30 facing each other substantially in the vehicle longitudinal direction are extended in parallel to each other. A substantially cylindrical spool 32 is disposed between the leg plates 28 and 30.

  The spool 32 has an axial direction opposite to the leg plates 28 and 30 and is rotatable around its own axis. In addition, a longitudinal base end portion of a long belt-like webbing belt 34 is locked to the spool 32.

  The webbing belt 34 is wound and accommodated in a layered manner from the base end side on the outer peripheral portion of the spool 32 by rotating the spool 32 in the winding direction which is one of its axes. Further, when the webbing belt 34 is pulled from the front end side, the webbing belt 34 wound around the spool 32 is pulled out, and accordingly, the spool 32 rotates in a pulling direction opposite to the winding direction.

  As shown in FIG. 2, if the webbing take-up device 10 according to the present embodiment is applied to a driver seat or a passenger seat of the vehicle 24, the webbing belt 34 extends along the center pillar 26 of the vehicle 24. Is pulled out substantially upward of the vehicle. A shoulder anchor 36 that constitutes the seat belt device 12 together with the webbing retractor 10 is attached to the vehicle body near the upper end of the center pillar 26. The shoulder anchor 36 is formed with a slit hole 38 that allows the webbing belt 34 to pass therethrough, and the webbing belt 34 drawn out from the spool 32 passes through the slit hole 38 and is folded back substantially downward in the vehicle. .

  Further, as shown in FIG. 2, an anchor plate 40 is attached to the vehicle body in the vicinity of the webbing take-up device 10, and the tip of the webbing belt 34 is locked to the anchor plate 40.

  Further, the tongue plate 42 can be displaced by a predetermined range along the webbing belt 34 between the front end portion of the webbing belt 34 locked to the anchor plate 40 and the folded portion of the webbing belt 34 at the shoulder anchor 36. Is provided. Further, a buckle device 46 is provided on the opposite side of the webbing take-up device 10 and the anchor plate 40 via the seat 44 of the vehicle 24.

  The buckle device 46 is provided so that the front end side of the tongue plate 42 can enter. When the tongue plate 42 enters the inside of the buckle device 46 from the front end side, a latch (not shown) provided inside the buckle device 46 is provided. The tongue plate 42 is engaged to restrict the movement of the tongue plate 42 in the direction of coming out of the buckle device 46.

  On the other hand, as shown in FIG. 1, a torsion shaft 48 is provided coaxially with respect to the spool 32 inside the spool 32. Further, a fitting hole 50 is formed at the end of the spool 32 along the axial direction on the leg plate 28 side. The fitting hole 50 has a substantially circular shape with a cross section substantially coaxial with the spool 32, and the fitting hole 50 has a stepped shape in which the inner diameter dimension gradually increases toward one end in the axial direction.

  On the other hand, a lock mechanism 52 is provided at one axial end of the spool 32. The lock mechanism 52 includes a lock base 54. The lock base 54 includes a fitting portion 56.

  The fitting portion 56 is formed in a substantially columnar shape corresponding to the inner peripheral shape of the fitting hole 50, and the outer dimension is gradually reduced toward the other axial end of the spool 32 (leg plate 30 side). The fitting portion 56 is fitted in the fitting hole 50 so as to be coaxially rotatable relative to the spool 32 inside the fitting hole 50, and the end portion 48A of the torsion shaft 48 on the leg plate 28 side is coaxial and They are connected together.

  The lock mechanism 52 includes a case 58. The case 58 is provided outside the leg plate 28 (that is, opposite to the leg plate 30), and is fixed to the leg plate 28 integrally with the leg plate 28 by fastening means such as screws and fitting means such as fitting claws. ing. Inside the case 58, a member constituting the lock mechanism 52 such as a ratchet gear and a compression coil spring (not shown), and a spiral spring that urges the lock base 54 directly or indirectly in the winding direction are accommodated. Has been.

  The ratchet gear in the case 58 is pivotally supported by the lock base 54 so as to be coaxial with and relative to the spool 32 and the lock base 54. One end of the compression coil spring in the case 58 is locked to the ratchet gear, and the other end is locked to the lock base 54.

  When the urging force of the compression coil spring is increased by the lock base 54 rotating and compressing or pulling the compression coil spring, the compression coil spring urges the ratchet gear in the rotation direction of the lock base 54 by the urging force. The ratchet gear is configured to rotate following the lock base 54.

  Further, the ratchet gear is engaged with the lock plate 60 attached to the lock base 54, and the ratchet gear cannot follow the lock base 54 that is about to rotate in the pull-out direction (that is, the ratchet gear is locked). When the lock plate 60 rotates relative to the base 54 in the winding direction), the lock plate 60 is guided by the ratchet gear and moves outward in the rotational radial direction of the spool 32, and the internal teeth formed on the leg plate 28. The ratchet teeth 62 are engaged with each other. As a result, the rotation of the lock base 54 and consequently the spool 32 in the pull-out direction is restricted.

  Further, an acceleration sensor for the lock mechanism 52 (not shown) is disposed below the ratchet gear in the radial direction. The acceleration sensor includes an engaging claw that can move toward and away from the ratchet gear, a steel ball provided on the opposite side of the engaging claw to the ratchet gear, and a substantially dish-shaped mounting on which the steel ball is placed. And a mounting portion.

  The acceleration sensor for the lock mechanism 52 engages the engagement claw with the ratchet gear when the steel ball rolls on the mounting portion in the vehicle suddenly decelerating state and the steel ball pushes up the engagement claw to move closer to the ratchet gear. To regulate the rotation of the ratchet gear.

  As described above, the ratchet gear rotates following the lock base 54 by the urging force of the compression coil spring. However, when the rotation of the ratchet gear is restricted by the engagement claw of the acceleration sensor engaging the ratchet gear, the ratchet gear A relative rotation occurs between the gear and the lock base 54. Thereby, the lock plate 60 meshes with the ratchet teeth 62 as described above.

  On the other hand, a sleeve 82 is provided at an end 48B of the torsion shaft 48 on the leg plate 30 side. The sleeve 82 is formed in a bottomed cylindrical shape that opens toward the leg plate 28 side, and an end portion 48B of the torsion shaft 48 enters inside thereof, and the torsion shaft 48 and the sleeve 82 are coaxially and integrally connected. Has been.

  A circular hole 84 is formed in the spool 32 corresponding to the sleeve 82. The sleeve 82 is fitted into the circular hole 84 and is connected to the spool 32 coaxially and integrally.

  A shaft portion 86 extends coaxially with respect to the torsion shaft 48 and the spool 32 from the end surface of the sleeve 82 opposite to the torsion shaft 48. The shaft portion 86 passes through a circular hole 88 formed in the leg plate 30 and protrudes outside the leg plate 30.

  A clutch frame 90 is integrally attached to the leg plate 30 on the outside of the leg plate 30 by fastening means such as screws and fixing means such as fitting claws. A clutch 92 is accommodated inside the clutch frame 90. The clutch 92 includes a ring-shaped worm wheel 94. The worm wheel 94 is disposed coaxially with the shaft portion 86.

  Further, one or more pawls are provided inside the worm wheel 94. The pawl is mechanically connected to the worm wheel 94 at a position eccentric from the rotation center of the worm wheel 94, and rotates around the shaft portion 86 together with the worm wheel 94. Further, the pawl can be rotated with respect to the worm wheel 94 about an axis parallel to the shaft portion 86 at a connecting portion with the worm wheel 94.

  Further, an adapter (not shown) is provided on the axial center portion of the worm wheel 94. The adapter is coaxially and integrally connected to the shaft portion 86, and rotates integrally with the shaft portion 86 and eventually the spool 32.

  Further, ratchet teeth are formed on the outer peripheral portion of the adapter, and when the pawl rotates, the tip of the pawl engages with the ratchet teeth on the outer peripheral portion of the adapter. In this engaged state, the worm wheel 94 is mechanically coupled to the shaft portion 86 via the pawl and the adapter, and the rotation of the worm wheel 94 in the winding direction is transmitted to the shaft portion 86 via the pawl and the adapter, so that the shaft The part 86 is structured to rotate in the winding direction.

  On the other hand, as shown in FIG. 1, a motor 100 as a driving unit is provided below the spool 32. The motor 100 is on the opening direction side of the frame 20 in which the output shaft 102 has a substantially concave shape in plan view, that is, on the extending direction side of the leg plates 28 and 30 from the back plate 22, and the tip side thereof is the above clutch. It enters a gear case (not shown) different from the frame 90.

  A spur gear 104 is accommodated in the gear case. The gear 104 is coaxially and integrally attached to the output shaft 102. A spur gear 106 having a sufficiently larger number of teeth than that of the gear 104 is disposed on the side of the rotational radius direction of the gear 104 in the gear case.

  The gear 106 has a rotating shaft 108 in the same direction as the gear 104, and meshes with the gear 104. Further, a spur gear 110 having a sufficiently smaller number of teeth than the gear 106 is coaxially and integrally formed on the gear 106.

  Further, a spur gear 112 having a sufficiently larger number of teeth than the gear 110 is disposed on the side of the gear 110 in the radial direction of rotation in the gear case.

  The gear 112 has a rotating shaft 114 in the same direction as the gears 104 to 112 and meshes with the gear 110. The rotation shaft 114 of the gear 112 protrudes from the gear case and further enters the clutch frame 90.

  In the clutch frame 90, a worm gear 116 is provided coaxially and integrally with the rotating shaft 114 on the rotating shaft 114. The worm gear 116 meshes with the worm wheel 94, and the rotation of the output shaft 102 of the motor 100 is transmitted to the worm gear 116 via the gears 104 to 112, and when the worm gear 116 rotates, Then, the worm wheel 94 rotates.

  On the other hand, as shown in FIG. 1, the motor 100 is electrically connected to the battery 124 via the driver 122, and the motor 100 is driven by being energized via the driver 122, and the output shaft 102 is driven. Rotate. The driver 122 is electrically connected to an ECU 126 as control means.

  The ECU 126 includes a calculation unit such as a CPU, a storage unit such as a RAM and a ROM, and a timer circuit that starts timing based on a predetermined signal. Further, the ECU 126 outputs a drive signal Dcs to the driver 122. When the drive signal Dcs output from the ECU 126 is input, the driver 122 supplies a forward current Id to the motor 100 to drive the motor 100 in the normal direction.

  As shown in FIG. 1, the ECU 126 is electrically connected to the buckle switch 130, and a signal Bs output from the buckle switch 130 is input to the ECU 126. As shown in FIG. 2, the buckle switch 130 is built in the buckle device 46.

  In a state where the tongue plate 42 is not inserted into the buckle device 46, the buckle switch 130 is in an OFF state, and the signal Bs output from the buckle switch 130 is at a low level. In contrast, when the tongue plate 42 is inserted into the buckle device 46 and the tongue plate 42 is attached to the buckle device 46, the buckle switch 130 is turned on, and the signal Bs is switched from the low level to the high level.

  The ECU 126 is electrically connected to a courtesy switch 136 serving as a door opening / closing detection means, and a signal Cds output from the courtesy switch 136 is input to the ECU 126. As shown in FIG. 2, the courtesy switch 136 is provided on the lower side of the door 134 (that is, the peripheral edge of the entrance / exit of the vehicle 24 corresponding to the seat 44).

  In a state where the door 134 closes the entrance / exit, the courtesy switch 136 is in an OFF state, and the signal Cds output from the courtesy switch 136 is at a low level. On the other hand, when the door 134 opens at the entrance, the courtesy switch 136 is turned on, and the signal Cds is switched from the Low level to the High level.

  Further, as shown in FIG. 1, ECU 126 is electrically connected to lock current detection circuit 150, and signal Ls output from lock current detection circuit 150 is input to ECU 126.

  The lock current detection circuit 150 constitutes a drive circuit for the motor 100. When the motor 100 is energized and the output shaft 102 rotates as usual, the lock current detection circuit 150 outputs a low level signal Ls.

  However, if the lock current larger than the normal drive current flows through the drive circuit of the motor 100 due to the rotation of the output shaft 102 being stopped even though the motor 100 is energized, the lock current detection circuit 150 A high level signal Ls is output.

<Operation and effect of the present embodiment>
Next, the operation and effect of the present embodiment will be described through the operation of the webbing take-up device 10.

  In the webbing take-up device 10, if the webbing belt 34 is pulled while pulling the tongue plate 42 while the webbing belt 34 is wound in layers on the spool 32, the webbing belt 34 wound on the spool 32 is pulled out. It is.

  The tongue plate 42 is inserted into the buckle device 46 while the webbing belt 34 pulled out in this way is wound around the front of the occupant's body. 34 is attached.

  As described above, when the tongue plate 42 is held in the buckle device 46, the signal Bs output from the buckle switch 142 is switched from the Low level to the High level.

  Next, for example, when the holding of the tongue plate 42 by the buckle device 46 is released when the occupant gets off, the signal Bs is switched from the High level to the Low level as shown in the state of the elapsed time T1 in FIG. In the ECU 126, the CPU of the ECU 126 reads the winding control program from the ROM, and the winding control program is started in the ECU step 200 as shown in FIG.

  As described above, when the signal Bs is switched from the High level to the Low level, it is determined in Step 202 that the signal Bs is not in the High level, and in Step 204, the drive signal Dcs is output from the ECU 126.

  The drive signal Dcs output from the ECU 126 is input to the driver 122. The driver 122 to which the drive signal Dcs is input causes the motor 100 to drive by supplying a current Id to the motor 100 as shown at the time T1 in FIG.

  When the worm wheel 94 rotates as the motor 100 rotates forward, the pawl of the clutch 92 rotates and meshes with the adapter. As a result, the output shaft 102 and the spool 32 are connected via the clutch 92, and the spool 32 is rotated in the winding direction by the normal driving force of the motor 100. As a result, the webbing belt 34 is wound around the spool 32.

  Next, at step 206, the timer circuit of the ECU 126 is activated, and an elapsed time t after the motor 100 starts driving is counted. Next, in step 208, it is determined whether or not the elapsed time t is smaller than a preset time ts, and the standby state is maintained until the elapsed time t exceeds the time ts, during which the motor 100 is driven.

  When the elapsed time t exceeds the time ts and becomes the state of the elapsed time T2 in FIG. 4, the process proceeds to step 210, and the output of the drive signal Dcs from the ECU 126 is stopped. As shown in FIG. 4, the supply of the current Id to the motor 100 is thereby stopped and the motor 100 is stopped.

  Therefore, in this state, the webbing belt 34 is not completely stored (that is, does not reach a state called “all storage”), and the webbing belt 34 is pulled out by a predetermined amount while being pulled out by a predetermined amount. Winding of the webbing belt 34 is stopped.

  Next, at step 212, it is determined whether or not the signal Cds is at a high level, and a standby state is maintained until the signal Cds is at a high level.

  In this state, when the door 44 is opened as shown at the elapsed time T3 in FIG. 4, the signal Cds is switched from the Low level to the High level. As a result, the process proceeds to step 214. In step 214, it is determined again whether or not the signal Cds is at the high level, and the standby state is maintained until the signal Cds becomes the low level.

  From this state, as shown at the time T4 in FIG. 4, for example, when the occupant gets off and the door 44 is closed and the signal Cds is switched from the high level to the low level, the drive signal is sent from the ECU 126 in step 216. Dcs is output again. When the drive signal Dcs output from the ECU 126 is input to the driver 122, the current Id is supplied to the motor 100 as shown in the elapsed time T4 in FIG.

  Next, at step 218, it is determined whether or not the signal Ls from the lock current detection circuit 150 is at a high level, and a standby state is entered until the high-level signal Ls is input to the ECU 126, during which the motor 100 is driven. The

  In this way, after the webbing belt 34 is taken up again, when the webbing belt 34 is taken up to a state called full storage after reaching the elapsed time T5 in FIG. 4, the longitudinal direction of the webbing belt 34 is reached. The spool 32 is unable to rotate in the winding direction due to the tension acting on the webbing belt 34 along the axis.

  As described above, the rotation of the output shaft 102 becomes impossible because the rotation of the spool 32 in the winding direction becomes impossible. However, even in this state, the current Id flows through the motor 100. As described above, when the current continues to flow through the motor 100 even though the output shaft 102 cannot rotate, the current flowing through the motor 100 increases and a so-called “lock current” flows.

  When the lock current flows in this way, the signal Ls output from the lock current detection circuit 150 is switched from the Low level to the High level. Thus, when the high level signal Ls is input to the ECU 126, the process proceeds from step 218 to step 220, and the output of the drive signal Dcs from the ECU 126 is stopped. As shown in FIG. 4, the supply of the current Id to the motor 100 is thereby stopped, the motor 100 is stopped, and the winding of the webbing belt 34 is completed.

  Here, in the present embodiment, as described above, the webbing belt 34 is wound up before the webbing belt 34 is in the state of being fully retracted, that is, in a state where the webbing belt 34 is extended by a certain amount. Is stopped and the door 44 is opened and closed, that is, after the passenger is considered to have got off, the unwinding portion of the webbing belt 34 is wound up.

  In the present embodiment, the configuration is such that the motor 100 is temporarily stopped after a certain period of time has elapsed after the motor 100 starts to be driven. However, the timing for temporarily stopping the motor 100 is set in terms of time. The configuration is not limited. For example, the motor 100 may be temporarily stopped based on the rotation amount of the output shaft 102 or the spool 32 of the motor 100.

  In the present embodiment, the motor 100 is driven immediately after the tongue plate 42 is removed from the buckle device 46, and the webbing belt 34 is wound up for the first time. However, the first webbing belt 34 may be wound up by driving the motor 100 after a predetermined time has elapsed after the tongue plate 42 is removed from the buckle device 46.

BRIEF DESCRIPTION OF THE DRAWINGS It is the front sectional view and the composite figure of a block diagram which show the outline of a structure of the webbing winding device concerning one embodiment of the present invention. It is a front view showing the outline of the composition of the seatbelt device to which the webbing retractor concerning one embodiment of the present invention is applied. It is a flowchart which shows the outline of the control program of the drive means at the time of winding up and storing a webbing belt. It is a time chart which shows the relationship of each signal of the drive means at the time of winding up and storing a webbing belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Webbing winding device 24 Vehicle 32 Spool 34 Webbing belt 44 Seat 100 Motor (driving means)
126 ECU (control means)
136 Courtesy switch (door open / close detection means)

Claims (1)

A webbing that winds the webbing belt around the outer periphery of the spool by rotating a spool, in which the base end of the long belt-like webbing belt is locked, in one winding direction around the axis by the driving force of the driving means. A winding device,
Door opening / closing detection means for detecting opening / closing of a vehicle door and outputting a closing signal when the door is closed;
The drive means is stopped by rotating the spool at a predetermined angle or for a predetermined time after the drive means starts driving, and the drive is stopped by driving the drive means to stop the drive means. Control means for resuming driving of the means;
A webbing take-up device comprising:

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