JP2004123038A - Webbing winding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a webbing winding device capable of shortening the generating time of mechanical sounds in diagnosis of a motor. <P>SOLUTION: The webbing winding device includes an ECU 86 to control a motor 60 to which a reversing current is fed for reversing its output shaft 62 at the time of diagnosis, and judgement whether the motor 60, the ECU 86, and/or a driver 82 are functioning normally is passed on the basis of whether the output shaft 62 is in reverse rotation. Therein the ECU 86 feeds the motor 60 with a current directed oppositely to the foregoing direction at the diagnosis ending time or immediately before it. Because the driving force generated by the motor 60 at this time acts in the direction opposite the rotation of the output shaft 62 till the time, the output shaft 62 is stopped forcedly. Thereby the output shaft 62 can be stopped in a short time, and the generating time of mechanical sounds due to the rotation of the output shaft 62 can be shortened. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a webbing take-up device that constitutes a seat belt device for restraining an occupant's body sitting on a seat of a vehicle or the like with a long belt-shaped webbing belt.
[0002]
[Prior art]
2. Description of the Related Art A seat belt device that restrains the body of an occupant seated on a vehicle seat with a long belt-shaped webbing belt includes a webbing winding device fixed to a vehicle body at a 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 end of the webbing belt is locked to the spool. The spool can take up the webbing belt around its outer periphery in a layered manner. When the seat belt device is not used, the webbing belt can be wound around and accommodated in the outer periphery of the spool.
[0003]
Further, the webbing take-up device is provided with an urging member such as a spiral spring for urging the spool in a winding direction in which the webbing belt is taken up. The urging force of the urging member winds the webbing belt. In a state in which the webbing belt is attached to the occupant's body while being accommodated, slackness and the like of the webbing belt are removed by the urging force of the urging member.
[0004]
On the other hand, by causing the webbing belt to be wound around the spool by the driving force of the motor during a vehicle sudden deceleration state, etc., a slight slack called "slack" or the like is eliminated, and the body of the occupant by the webbing belt is removed. Mechanisms for increasing the restraint force and more securely holding the occupant's body have also been considered. This type of mechanism detects a sudden deceleration state of a vehicle with an acceleration sensor, drives a motor based on an electric signal from the acceleration sensor, and forcibly rotates a spool in a winding direction by a driving force of the motor. Is common.
[0005]
On the other hand, the distance to other vehicles or obstacles ahead is detected by a forward monitoring device such as a distance sensor, and when the distance to the preceding vehicle or obstacle is less than a certain value, the motor is driven, and the motor is driven. A configuration in which the spool is rotated in the winding direction by the rotational force of the webbing belt to thereby eliminate slack and increase the restraining force of the webbing belt is also considered (as an example of a webbing winding device having such a configuration, See Patent Document 1 below).
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2001-347923
[Problems to be solved by the invention]
By the way, in the case of the configuration in which the spool is rotated in the winding direction by the motor to increase the binding force, the motor and the control circuit for controlling the motor are periodically diagnosed, and the motor and the control circuit function normally. It is necessary to confirm whether or not.
[0008]
In the case of such a configuration, for example, immediately before the vehicle starts moving, the control circuit is operated to temporarily drive the motor, and if the motor is driven normally, the motor and the control circuit are functioning normally. If the diagnosis is made and the motor does not operate normally, it is diagnosed that some abnormality has occurred in the motor and the control circuit.
[0009]
Here, when the motor is operated as described above, mechanical noise is generated because the output shaft, the gear meshing with the output shaft, and other gears connected to this gear rotate. In addition, since the output shaft rotates by inertia even when the power supply to the motor is stopped, mechanical noise continues to be generated for a short time after the power supply to the motor is stopped. Such a mechanical noise may cause occupants to feel uncomfortable, leaving much room for improvement.
[0010]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a webbing take-up device that can reduce the time required to generate a mechanical sound during motor diagnosis in consideration of the above fact.
[0011]
[Means for Solving the Problems]
The webbing take-up device according to claim 1, wherein a long belt-shaped webbing belt for restraining the body of an occupant seated on a vehicle seat in a mounted state, a base end side of the webbing belt in a longitudinal direction is locked, and the webbing take-up device has its own shaft. A rotating shaft that winds the webbing belt from the base end side to the outer peripheral portion by rotation in one surrounding winding direction, and an output shaft directly or indirectly connected to the winding shaft; When the power is supplied in the forward direction, the output shaft is driven forward, and the output shaft is rotated in one direction around the axis. Driving to rotate the winding shaft in the winding direction or the drawing direction opposite to the winding direction by rotating the output shaft in the reverse direction and rotating the output shaft in at least one of the normal rotation and the reverse rotation. Means including the driving means The drive means is electrically connected to the drive means via a circuit, and the drive means is energized for a certain time at the time of diagnosis of the electric circuit, and the drive means is driven in one of the forward drive state and the reverse drive state. At the time of or immediately before the end of the diagnosis, power is supplied in a direction opposite to the direction of power supply to the driving means in the one of the states, and the driving means is driven in the forward rotation driving state and the reverse rotation. Control means for setting one of the driving states to the other.
[0012]
According to the webbing take-up device having the above-described configuration, the occupant sits on the seat of the vehicle, wraps the webbing belt around the body, and, for example, engages the tongue plate provided on the webbing belt with the buckle device. The belt is put on the occupant's body.
[0013]
On the other hand, in the present webbing take-up device, a drive unit is directly or indirectly connected to the take-up shaft, and when the drive unit is driven, the output shaft rotates forward or backward. The rotation of at least one of the forward rotation and the reverse rotation of the output shaft is transmitted to the winding shaft, and the winding shaft is rotated in the winding direction or the drawing direction.
[0014]
Therefore, for example, when the forward monitoring unit or the like detects an obstacle existing in front of the vehicle, the driving unit is driven, and the winding shaft is rapidly rotated in the winding direction by the rotation of the output shaft at this time. Thus, the webbing belt is wound around the winding shaft. As a result, the so-called "slack", which is a slight slack of the webbing belt, is eliminated, and the restraining force for restraining the occupant's body by the webbing belt is increased, so that the occupant's body can be reliably held.
[0015]
On the other hand, in the webbing take-up device, the electric circuit including the driving unit is diagnosed, and it is determined whether or not the electric circuit is functioning normally.
[0016]
When performing this diagnosis, first, the drive unit is energized for a certain period of time by the control unit. As a result, basically, the drive means enters one of the forward drive state and the reverse drive state. That is, when the drive unit is energized, if any one of these states is established, it can be determined that the electric circuit including the drive unit is functioning normally. On the other hand, even if the drive unit is energized, if any one of these states does not occur, it can be determined that some abnormality has occurred in the electric circuit including the drive unit.
[0017]
At the time of or immediately after the end of the diagnosis, the control unit causes the drive unit to supply a current having a direction opposite to the direction of the current flowing to the drive unit when setting the state to one of the above states.
[0018]
In this way, when the current in the opposite direction is passed through the driving means, the direction of the driving force of the driving means that has attempted to rotate the output shaft to one of the forward rotation and the reverse rotation until now becomes reverse, and Act in the direction opposite to the rotation direction of the output shaft.
[0019]
When a driving force in a direction opposite to the rotation direction of the output shaft acts on the output shaft, the power supply to the driving means is simply stopped, and the output shaft is forcibly stopped earlier than when the output shaft naturally stops. Can be As a result, it is possible to reduce the generation time of the mechanical noise generated by the rotation of the output shaft.
[0020]
According to a second aspect of the present invention, in the webbing winding device according to the first aspect, the webbing winding device is interposed between the output shaft and the winding shaft to mechanically connect the output shaft and the winding shaft. And a clutch for transmitting only the rotation of the output shaft to the winding shaft in either one of the states of the driving means.
[0021]
In the webbing take-up device having the above configuration, a clutch is interposed between the output shaft of the driving means and the take-up shaft, and the output shaft and the take-up shaft are mechanically connected by the clutch. However, the clutch connects the winding shaft and the output shaft only when the output shaft rotates in one of the forward rotation and the reverse rotation, and only the rotation in either one of the directions rotates on the winding shaft. When the output shaft is rotated to one of the other ends, the mechanical connection between the output shaft and the winding shaft is released, and the rotation of the output shaft is not transmitted to the winding shaft.
[0022]
Here, the rotation direction of the output shaft transmitted by the clutch is opposite to the rotation direction when the drive unit is first energized and driven during diagnosis. For this reason, at the time of diagnosis, the drive unit is driven to rotate the output shaft, but the winding shaft does not rotate. For this reason, for example, even if the occupant wears the webbing belt before the diagnosis, the webbing belt is wound around the winding shaft at the time of diagnosis to increase the restraining force, or conversely, the webbing belt on the winding shaft. Is not loosened, and does not make the occupants feel uncomfortable at the time of diagnosis.
[0023]
According to a third aspect of the present invention, in the webbing take-up device according to the first or second aspect, the rotation direction of the take-up shaft interlocked with the rotation direction of the output shaft in the one of the other states. It is characterized by the winding direction.
[0024]
In the webbing take-up device having the above configuration, the driving force of the drive means at the end of or immediately after the completion of the above-described diagnosis acts in a direction for rotating the take-up shaft in the take-up direction via the output shaft.
[0025]
Therefore, the driving force of the driving means at the start of diagnosis does not rotate the winding shaft in the winding direction. For this reason, for example, even if the occupant wears the webbing belt before the diagnosis, there is no problem that the restraining force is rapidly increased by the webbing belt at the time of diagnosis and the occupant has an unnecessary feeling of pressure.
[0026]
According to a fourth aspect of the present invention, in the webbing take-up device according to the first aspect of the present invention, the control unit is provided to an ignition device that activates the vehicle by a predetermined activation operation using an ignition key. And performing the diagnosis at the time of the start operation or immediately after the end of the start operation.
[0027]
In the webbing take-up device having the above configuration, the control means is connected to the ignition device, and a predetermined starting operation by an ignition key, for example, starting the engine or starting the engine so that the audio device mounted on the vehicle can be used without starting the engine. Then, the control means makes the above diagnosis. This makes it possible to confirm whether or not an abnormality has occurred in the electric circuit including the driving means before the vehicle starts moving.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
<Configuration of the present embodiment>
FIG. 1 is a front cross-sectional view schematically showing the overall configuration of a webbing take-up device 10 according to an embodiment of the present invention.
[0029]
As shown in this figure, the webbing take-up device 10 includes a frame 12. The frame 12 is provided with a substantially plate-shaped back plate 14, and the back plate 14 is fixed to the vehicle body by a not-shown fastening means such as a bolt, so that the webbing retractor 10 is attached to the vehicle body. ing. A pair of leg plates 16 and 18 extend parallel to each other from both ends in the width direction of the back plate 14, and a spool 20 as a winding shaft manufactured by die casting or the like is rotatable between the leg plates 16 and 18. Are located.
[0030]
The spool 20 includes a substantially cylindrical spool main body 22 and a pair of flange portions 24 and 26 formed at both ends of the spool main body 22 in a substantially disk shape, respectively. I have.
[0031]
The base end of a webbing belt 28 formed in a long strip shape is fixed to the spool body 22 between the flange portions 24 and 26. When the spool 20 is rotated to one side around its axis, the webbing belt 28 is It is wound up in a layer form on the outer periphery of the spool body 22 from the base end side. Further, when the webbing belt 28 is pulled from the front end side, the webbing belt 28 wound around the outer peripheral portion of the spool body 22 is pulled out, and accordingly, the rotation direction when the webbing belt 28 is wound (hereinafter, this direction). Is referred to as a “winding direction” for the sake of convenience (hereinafter, the rotating direction of the spool 20 when the webbing belt 28 is pulled out is referred to as a “drawing direction” for convenience).
[0032]
One end of the spool 20 on the side opposite to the flange 26 of the flange 24 penetrates substantially coaxially through a circular hole 30 formed in the leg plate 16 and projects outside the frame 12. A case 32 is arranged outside the frame 12 on the leg plate 16 side. The case 32 is disposed to face the leg plate 16 along the axial direction of the spool 20 and is fixed to the leg plate 16. The case 32 is entirely open toward the leg plate 16, and one end of the spool 20 penetrating the circular hole 30 enters the inside of the case 32 and is rotatably supported by the case 32.
[0033]
Further, a spiral spring 34 is arranged inside the case 32. The spiral spring 34 has an outer end in the spiral direction locked to the case 32, and an inner end in the spiral direction locked to the spool 20. When the spiral spring 34 rotates the spool 20 in the pull-out direction from a neutral state in which no special load is applied, a biasing force in the winding direction is generated to bias the spool 20 in the winding direction. Therefore, basically, when the pulling force applied to the webbing belt 28 to be pulled out from the spool 20 is released, the urging force of the spiral spring 34 rotates the spool 20 in the winding direction, and the webbing belt 28 is wound around the spool 20. It has a structure to be taken.
[0034]
On the other hand, the other end of the spool 20 on the side opposite to the flange 24 of the flange 26 projects substantially coaxially through the ratchet hole 36 of the internal teeth formed on the leg plate 18 and protrudes to the outside of the frame 12. . A lock mechanism 38 is arranged outside the frame 12 on the side of the leg plate 18. The lock mechanism 38 has a case 40. The case 40 is arranged facing the leg plate 18 along the axial direction of the spool 20 and is fixed to the leg plate 18.
[0035]
A ratchet gear 42 constituting the lock mechanism 38 is accommodated inside the case 40 so as to be coaxial with the spool 20 and rotatable relative to the spool 20. The ratchet gear 42 has a shallow cylindrical shape with an opening on the side opposite to the axial leg plate 18, and has ratchet teeth formed on an outer peripheral portion thereof.
[0036]
A lock base 44 is housed inside the ratchet gear 42. The lock base 44 is provided coaxially and integrally with the spool 20, and thus rotates integrally with the spool 20 by rotation of the spool 20. The lock base 44 is provided with an urging means such as a compression coil spring (not shown). This urging means is partially engaged with the above-described ratchet gear 42, and when the lock base 44 rotates, the urging means rotates together with the lock base 44 to apply an urging force along the rotation direction to the ratchet gear 42. I do. For this reason, the ratchet gear 42 is originally rotatable relative to the spool 20, but the ratchet gear 42 is rotated by the urging force applied by the urging means when the lock base 44 rotates integrally with the spool 20. It is configured to rotate following the rotation of 20.
[0037]
On the other hand, a lock plate 46 is supported by the lock base 44 inside the ratchet hole 36 described above. The lock plate 46 can move toward and away from the internal teeth of the ratchet hole 36 while being supported by the lock base 44. The lock plate 46 is engaged with the above-described ratchet gear 42. When the ratchet gear 42 rotates relative to the lock base 44 in the above-described winding direction, the ratchet hole 36 is interlocked with this rotation. And the inner teeth of the ratchet hole 36 mesh with the inner teeth of the ratchet hole 36.
[0038]
A sensor frame 48 is disposed radially below the ratchet gear 42 in the radial direction. The sensor frame 48 has a mounting portion (not shown) which is curved at a predetermined curvature and opened upward, and the sensor ball 50 is mounted on the mounting portion. An engagement plate 52 is provided above the sensor ball 50. The engagement plate 52 is attached to the sensor frame 48 so as to be rotatable up and down. When the sensor ball 50 rolls on the mounting portion and is displaced upward, the sensor ball 50 is pressed from above. And rotate. An engagement claw 54 is formed on the engagement plate 52. The engaging claw 54 has its tip end facing the ratchet teeth of the ratchet gear 42, and when the engaging plate 52 rotates upward, the engaging claw 54 meshes with the ratchet teeth of the ratchet gear 42, and rotates the ratchet gear 42. It is configured to regulate.
[0039]
On the other hand, a motor 60 as driving means is disposed below the spool 20 and between the leg plate 16 and the leg plate 18. A gear 64 is coaxially and integrally provided on an output shaft 62 of the motor 60.
[0040]
A gear 66 having a larger diameter than the gear 64 is disposed radially above the gear 64. The gear 66 meshes with the gear 64 while being rotatably supported around a shaft parallel to the spool 20 by a support plate 68 provided between the leg plates 16 and 18 and the leg plate 16. A gear 70 having a smaller diameter than the gear 66 is provided coaxially and integrally with the gear 66 on the axial side of the gear 66.
[0041]
Further, a clutch 72 is provided on the radially upper side of the gear 70. The clutch 72 includes an external gear 74 formed in a ring shape. The gear 74 is provided coaxially with the spool 20 so as to be relatively rotatable, and both ends in the axial direction are closed by disc-shaped members (not shown). A cylindrical adapter 76 is provided coaxially with the spool 20 inside the gear 74. The adapter 76 is provided coaxially and integrally with the spool 20, and allows the disk-shaped member, and eventually the gear 74, to rotate around the spool 20 while penetrating the disk-shaped member closing both ends of the gear 74. It is pivoted.
[0042]
Inside the gear 74, for example, a coupling member such as a pawl that swings by centrifugal force generated by rotation of the gear 74 in the winding direction is accommodated. The connecting member is supported by, for example, the above-mentioned disc-shaped member, is rotatable together with the gear 74, and swings by centrifugal force, thereby engaging with the outer peripheral portion of the adapter 76 and engaging with the gear 74 and the adapter 76. Are mechanically connected to each other so that the rotational force of the gear 74 can be transmitted to the adapter 76 and eventually to the spool 20.
[0043]
That is, the clutch 72 can transmit the rotation of the gear 74 in the winding direction to the spool 20, but cannot transmit the rotation of the gear 74 in the pull-out direction to the spool 20. The rotation cannot be transmitted to the gear 74.
[0044]
On the other hand, as shown in FIG. 1, the above-mentioned motor 60 is electrically connected to a battery 84 mounted on the vehicle via a driver 82 constituting a control means. , The motor 60 rotates the output shaft 62 in the forward or reverse direction. The driver 82 is connected to an ECU 86 which is constituted by a microcomputer or the like and constitutes control means, and the ECU 86 is further connected to a forward monitoring device 88 as forward monitoring means.
[0045]
The forward monitoring device 88 includes an infrared sensor 90 provided near the front end of the vehicle. The infrared sensor 90 emits infrared rays in front of the vehicle, and is used for other vehicles or obstacles running or stopping in front of the vehicle (hereinafter, also referred to as “obstacles” including vehicles running or stopped) for convenience. It receives the reflected infrared sensor 90. The forward monitoring device 88 includes a calculation unit 92. The computing unit 92 computes the distance to the obstacle based on the time required from when the infrared sensor 90 emits infrared rays to when it reflects off the obstacle and returns to the infrared sensor 90. In addition, the calculation unit 92 outputs an obstacle detection signal Os to the ECU 86 based on the calculation result. The obstacle detection signal Os has a low level when the distance to the obstacle is equal to or more than a predetermined value, and has a high level when the distance to the obstacle is less than the predetermined value.
[0046]
Further, the ECU 86 is connected to an acceleration sensor 94 as acceleration detection means provided at an appropriate position in the vehicle. The acceleration sensor 94 detects acceleration when the vehicle decelerates (in other words, deceleration). The acceleration sensor 94 basically outputs a low-level acceleration detection signal Bs to the ECU 86, but detects an acceleration having a predetermined change rate, that is, an acceleration corresponding to a vehicle sudden deceleration state due to a sudden braking or the like. In this case, a high-level acceleration detection signal Bs is output to the ECU 86.
[0047]
Further, the ECU 86 is connected to an ignition device 96. The ignition device 96 includes a key cylinder (not shown), into which an ignition key (not shown) is inserted. When the ignition key for this key cylinder is inserted and the ignition key is rotated by a predetermined angle around an axis whose axis is the direction of insertion of the ignition key, the vehicle enters a so-called accessory mode, and the engine does not start but the vehicle is turned on. Use of the mounted audio device or the like becomes possible. Further, when the ignition key is turned at a predetermined angle or more, the engine starts.
[0048]
The ignition device 96 outputs a low-level activation signal Ks (hereinafter, the activation signal Ks is simply referred to as a “signal Ks”) until the ignition angle of the ignition key reaches a predetermined angle. When a predetermined angle is reached, a high-level signal Ks is output.
The signal Ks is input to the ECU 86, and when the signal Ks input to the ECU 86 switches from the low level to the high level, the ECU 86 switches the electric circuit including the motor 60, the driver 82, the ECU 86, the forward monitoring device 88, and the acceleration sensor 94. It is configured to diagnose whether or not it is functioning normally.
[0049]
<Operation and effect of the present embodiment>
Next, the operation and effect of the present embodiment will be described through the description of the operation of the webbing take-up device 10.
[0050]
First, the basic operation of the webbing winding device 10 will be described.
[0051]
In the webbing take-up device 10, when the webbing belt 28 is pulled while pulling a tongue plate (not shown) in a housed state in which the webbing belt 28 is wound in a layer on the spool 20, a spiral that urges the spool 20 in the winding direction is provided. The webbing belt 28 is pulled out while rotating the spool 20 in the pulling-out direction against the urging force of the spring 34. In this manner, with the webbing belt 28 pulled out, the tongue plate is inserted into the buckle device (not shown) while the webbing belt 28 is wrapped around the body of the occupant sitting on the seat, and the buckle device holds the tongue plate. As a result, the state in which the webbing belt 28 is worn on the occupant's body (hereinafter, simply referred to as “wearing state”) is established.
[0052]
When the webbing belt 28 is pulled out to mount the webbing belt 28 and the spool 20 is rotated in the pull-out direction, the spiral spring 34 is wound and tightened, and the spiral spring 34 for urging the spool 20 in the winding direction is attached. The power increases. Therefore, in the above-mentioned mounted state, the urging force of the spiral spring 34 acts to wind the webbing belt 28 around the spool 20, so that the webbing belt 28 basically fits the occupant's body with this urging force, The webbing belt 28 restrains and holds the occupant's body with a force corresponding to the urging force at this time.
[0053]
On the other hand, when the holding of the tongue plate by the buckle device is released and the tongue plate comes out of the buckle device, the force for maintaining the webbing belt 28 in the pulled-out state against the urging force of the spiral spring 34 is released. The spring 34 rotates the spool 20 in the winding direction by the urging force. The webbing belt 28 pulled out by the rotation of the spool 20 in the winding direction is wound in a layer around the outer periphery of the spool 20, and the webbing belt 28 is stored.
[0054]
Here, since the spool 20 is fitted to the adapter 76 of the clutch 72, when the spool 20 is rotated to pull out or wind up the webbing belt 28, the adapter 76 rotates. However, as described above, since the clutch 72 does not transmit the rotation of the adapter 76 to the gear 74, the gear 74 does not rotate in this state. Therefore, the rotation of the spool 20 is not transmitted to the output shaft 62 of the motor 60 via the gears 74, 70, 68, 66, 64.
[0055]
On the other hand, in the running state of the vehicle, the calculating unit 92 calculates the distance to the obstacle ahead of the vehicle based on the detection result of the infrared sensor 90 of the forward monitoring device 88. For example, when there is no obstacle in front of the vehicle, or when there is an obstacle but the distance from the obstacle to the vehicle is a predetermined value or more, the low-level signal Os is output from the calculation unit 92 ( (See the state up to time T1 in the time chart of FIG. 3).
[0056]
On the other hand, when the distance from the vehicle to the obstacle in front is smaller than the predetermined value, the high-level signal Os is output from the calculation unit 92 (the state between the times T1 and T2 in the time chart of FIG. 3). See).
[0057]
When the High level signal Os from the arithmetic unit 92 is input to the ECU 86, the ECU 86 outputs a predetermined operation signal to the driver 82, and the current I of the current value IA (hereinafter, flowing in this state) flows to the motor 60. The current I having the current value IA is referred to as “forward drive current IA” for convenience.
[0058]
As a result, the motor 60 enters the forward drive state, and rotates the output shaft 62 forward. The forward rotation of the output shaft 62 causes the gear 74 of the clutch 72 to rotate in the winding direction via the gears 64 to 70. As described above, when the gear 74 rotates in the winding direction, the gear 74 and the adapter 76 are mechanically connected by the connecting member of the clutch 72, and the rotation of the gear 74 is transmitted to the adapter 76. The adapter 76 is rotated in the winding direction.
[0059]
The rotation of the adapter 76 in the winding direction rotates the spool 20 in the winding direction, and winds the webbing belt 28. In this manner, by winding the webbing belt 28 around the spool 20, so-called "slack", which is a slight slack of the webbing belt 28, is removed, and the restraining force of the webbing belt 28 is increased. Retained securely.
[0060]
Further, when the occupant performs a sudden braking (braking) operation in a running state of the vehicle, the vehicle is rapidly decelerated. When the acceleration sensor 94 detects the acceleration in this state, the Low level signal Bs is output until then. The output acceleration sensor 94 outputs a high-level signal Bs to the ECU 86 (see the state between the times T3 and T4 in the time chart of FIG. 3). The ECU 86 to which the high-level signal Bs has been input outputs a predetermined operation signal to the driver 82, and the driver 82 to which the operation signal has been input flows the normal rotation drive current IA to the motor 60.
[0061]
As a result, the motor 60 enters the forward rotation driving state, as in the case where the High level signal Os is input to the ECU 86, and the webbing belt 28 is wound around the spool 20. As a result, the slack is removed, the restraining force by the webbing belt 28 is increased, and the body of the occupant who moves to the front side of the vehicle due to inertia in the vehicle sudden deceleration state can be reliably held by the webbing belt 28.
[0062]
By the way, the occupant gets into the vehicle, inserts the ignition key into the key cylinder, and further turns the ignition key by a predetermined angle to set the vehicle in the accessory mode, or turns the ignition key by a predetermined angle or more to start the engine. Then, as shown in FIG. 3, a high-level signal Ks is output from the ignition device 96. When the high-level signal Ks is input to the ECU 86, the ECU 86 outputs a predetermined operation signal to the driver 82 to cause the motor 60 to rotate in a direction opposite to the forward drive current IA having the current value IB (that is, the current). A current I having a value of -IB) (hereinafter, a current I having a current value IB flowing in this state is referred to as a "reverse drive current IB" for convenience) flows.
[0063]
As a result, basically, the motor 60 is in a reverse rotation driving state, and the output shaft 62 is reversely rotated. As described above, when the motor 60 is in the reverse rotation driving state and the output shaft 62 rotates in the reverse direction, it is determined that the electric circuit including the motor 60, the driver 82, the ECU 86, the forward monitoring device 88, and the acceleration sensor 94 is functioning normally. The determination is made by the ECU 86 or other determination means.
[0064]
On the other hand, if the output shaft 62 does not reverse, the ECU 86 or other determination means determines that the electric circuit including the motor 60, the driver 82, the ECU 86, the forward monitoring device 88, and the acceleration sensor 94 is in an abnormal state. For example, the ECU 86 or other determination means turns on an abnormality notification lamp provided on the instrument panel of the vehicle, and controls the motor 60, the driver 82, the ECU 86, the forward monitoring device 88, and the acceleration sensor 94. Notifies that the included electric circuit is abnormal.
[0065]
Here, the webbing take-up device 10 performs the above-described diagnosis based on the signal Ks from the ignition device 96 as described above, so that it is possible to confirm whether an abnormality has occurred before the vehicle starts moving.
[0066]
At the time of the above diagnosis, the motor 60 is driven in the reverse rotation state, and the output shaft 62 is rotated in the reverse direction. Moreover, the clutch 72 does not transmit the rotation of the output shaft 62 in the reverse direction to the spool 20. Therefore, the spool 20 does not rotate at the time of diagnosis. For this reason, the webbing belt 28 is not wound around the spool 20 at the time of diagnosis, so that the restraining force does not increase, and the occupant does not feel discomfort such as oppression at the time of diagnosis.
[0067]
Next, as shown in FIG. 2, the ECU 86 stops supplying the reverse rotation drive current IB to the motor 60 when a certain time T5 has elapsed from the time T0 when the reverse rotation drive current IB is supplied to the motor 60. Further, in the present webbing take-up device 10, after the time T6 has elapsed, the ECU 86 outputs a predetermined operation signal to the driver 82, and the absolute value of the current value IC is the same as the forward drive current IA and the reverse drive current IB A smaller current I (hereinafter, the current I of this current value IC is referred to as “forward drive current IC” for convenience) is supplied to the motor 60 until the time T8 is reached.
[0068]
When the forward drive current IC is supplied to the motor 60, the motor 60 enters the forward drive state, and attempts to rotate the output shaft 62 in the forward direction. However, immediately before this, although the power supply to the motor 60 is temporarily stopped, since the output shaft 62 is rotating in the reverse direction by inertia, the forward drive current IC generated by the flow of the forward drive current IC to the motor 60 is generated. The output shaft 62 does not rotate forward due to the rotation driving force. However, the forward rotation driving force thus generated acts to prevent the rotation of the output shaft 62 that rotates in the reverse direction, so that the rotation speed V of the output shaft 62 in the reverse rotation direction rapidly decreases, and the elapsed time T8 The output shaft 62 stops when the previous time T7 is reached.
[0069]
As described above, in the webbing take-up device 10, by simply applying a driving force in a direction opposite to the rotation direction of the output shaft 62 at the time of diagnosis to the output shaft 62, the energization of the motor 60 is simply stopped, and The output shaft 62 can be stopped earlier than the output shaft 62 stops. As a result, it is possible to reduce the time required to generate a mechanical sound caused by the rotation of the output shaft 62 at the time of diagnosis.
[0070]
【The invention's effect】
As described above, in the webbing take-up device according to the present invention, at the end of diagnosis or immediately before the end of diagnosis, a driving force in a direction opposite to the rotation direction of the output shaft is applied to the output shaft. Can be stopped immediately, so that the time required to generate a mechanical sound caused by the rotation of the output shaft at the time of diagnosis can be reduced.
[Brief description of the drawings]
FIG. 1 is a front view schematically showing an overall configuration of a webbing take-up device according to an embodiment of the present invention.
FIG. 2 is a time chart showing a relationship between a signal from an ignition device, a current flowing through a driving unit, and a rotation speed of an output shaft in the webbing take-up device according to one embodiment of the present invention.
FIG. 3 is a time chart showing a relationship between signals from an acceleration sensor and a forward monitoring device, a current flowing through a driving unit, and a rotation speed of an output shaft in the webbing take-up device according to one embodiment of the present invention.
[Explanation of symbols]
10 Webbing take-up device 20 Spool (take-up shaft)
28 Webbing belt 60 Motor (drive means)
62 output shaft 72 clutch 82 driver (control means)
86 ECU (control means)

Claims (4)

A long belt-shaped webbing belt that restrains the body of an occupant seated on a vehicle seat in a mounted state,
A winding shaft that winds the webbing belt from the base end side to the outer peripheral portion by rotation of the webbing belt in the one winding direction around its own axis in the longitudinal direction base end side,
An output shaft directly or indirectly connected to the winding shaft; a power is supplied in a predetermined direction to be in a forward rotation driving state, and the output shaft is rotated in one direction around the axis; The power is supplied in a direction opposite to the rotation driving state, whereby the output shaft is reversely rotated to the other around the axis, and the winding shaft is rotated by rotation of at least one of the forward rotation and the reverse rotation. Driving means for rotating the winding direction or the drawing direction opposite to the winding direction,
The drive unit is electrically connected to the drive unit via an electric circuit including the drive unit, and when the electric circuit is diagnosed, the drive unit is energized for a certain period of time to drive the drive unit in the forward drive state and the reverse drive state. State, and at the time of or immediately before the end of the diagnosis, power is supplied in a direction opposite to the direction of power supply to the drive unit in the one of the states, and the drive unit is set to the normal state. Control means for setting the other of the rotation driving state and the reverse rotation driving state,
Webbing take-up device comprising: Interposed between the output shaft and the winding shaft, the output shaft and the winding shaft are mechanically connected to each other, and only the rotation of the output shaft in one of the states of the driving unit is controlled. Comprising a clutch means for transmitting to the winding shaft,
The webbing take-up device according to claim 1, wherein: The rotation direction of the winding shaft interlocked with the rotation direction of the output shaft in any one of the other states was the winding direction,
The webbing take-up device according to claim 1 or 2, wherein: Connecting the control means to an ignition device that starts the vehicle by a predetermined start operation by an ignition key, and performing the diagnosis at the time of the start operation or immediately after the end of the start operation;
The webbing take-up device according to any one of claims 1 to 3, wherein:

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