JP2006143154A - Web winding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a web winding deice capable of attaining both a passenger's comfortable feeling and restriction. <P>SOLUTION: A winding biasing force of a spring acted on a taking-up shaft is increased or decreased by driving a motor and rotating a spring holding box in a normal direction or reverse direction, an excessive feeling of a pressure of a web can be reduced or eliminated and a passenger's comfortable feeling can be assured. Further, when the passenger sets a web, a maximum taking-up amount (that is, a taking-up amount of the web against a taking-up shaft for the web under a state in which a so-called slack is minimum) under the set state is detected by a control means. Then, when the web is pulled out by an amount more than a predetermined amount against the aforesaid maximum taking-up amount and the pulled-out state is kept for a predetermined time, a control means judges that an excessive slack occurs, for example, causes an output shaft of a motor to be rotated in a normal direction and further causes a taking-up biasing force with a spring to be increased. With this arrangement, the aforesaid excessive slack is eliminated and a superior restriction with the web can be assured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a webbing take-up device that constitutes a seat belt device for a vehicle and winds and stores a webbing for restraining an occupant on a take-up shaft.

  As a webbing take-up device, a spring for applying a take-up biasing force to a take-up shaft is locked to a spring holding box, and the spring holding box is rotated by a motor to adjust the take-up biasing force by the spring. There is a known one equipped with a so-called tension reducer mechanism (see, for example, Patent Document 1).

  In this type of webbing take-up device, when the occupant wears the webbing, the excessive urging feeling at the time of wearing the webbing can be reduced or eliminated by reducing the winding urging force by the spring (torque down). it can. Further, when the occupant releases the webbing wearing state, the winding urging force by the spring is increased (torque up), thereby ensuring good winding performance of the webbing.

By the way, a slight slack called so-called “slack” occurs in the webbing in a normal wearing state. Since such webbing slack affects the occupant restraint during sudden deceleration of the vehicle, it is desirable to remove all of them. On the other hand, in order to ensure the comfort of the occupant wearing the webbing, it is necessary to reduce the winding urging force by the spring as described above, but this makes it easy to cause the above-mentioned slack. There is a trade-off problem.
Japanese Utility Model Publication No. 63-5965

  In view of the above facts, an object of the present invention is to provide a webbing take-up device capable of achieving both passenger comfort and restraint.

  In order to solve the above-mentioned problem, a webbing take-up device according to a first aspect of the present invention is configured such that one end is connected to a take-up shaft from which a webbing for restraining an occupant is taken up and taken out, and a take-up biasing force is applied to the take-up shaft. The spring to be applied and the other end of the spring are locked and rotatably provided, and the winding biasing force by the spring is increased by rotating a specific amount in the forward direction, and in the reverse direction. A spring holding box and an output shaft are connected to the spring holding box so that the winding urging force by the spring is reduced by rotating the specific amount, and the spring holding box is normally moved by forward rotation of the output shaft. A motor that rotates the spring holding box in the reverse direction by rotating the output shaft in a reverse direction, and the webbing when the occupant is mounted on the webbing When the webbing is pulled out a predetermined amount or more with respect to the maximum winding amount and the state is maintained for a predetermined time, the maximum winding amount of the motor is detected. And a control means for causing the output shaft to rotate forward to increase the winding biasing force.

  In the webbing take-up device according to the first aspect, by driving the motor and rotating the spring holding box in the forward and reverse directions, the take-up biasing force of the spring acting on the take-up shaft can be increased or decreased. Therefore, if the motor is driven when the webbing is mounted, the excessive pressure feeling of the webbing can be reduced or eliminated, and passenger comfort can be ensured.

  Further, when the occupant wears the webbing, the maximum winding amount of the webbing on the winding shaft in the mounted state (that is, the winding amount of the webbing on the winding shaft in a state where the so-called slack is minimized) is controlled. Detected by means. Then, when the webbing is pulled out a predetermined amount or more with respect to the maximum winding amount and the state is maintained for a predetermined time, the control means determines that, for example, excessive slack has occurred, and the motor output shaft Rotate forward to rotate the spring holding box a specific amount in the forward direction. Thereby, since the winding urging force by the spring is increased, the excessive slack is removed, and good restraint by webbing is ensured.

  Thus, in the webbing retractor according to the first aspect, it is possible to achieve both comfort and restraint for the passenger.

  The webbing take-up device according to a second aspect of the present invention is the webbing take-up device according to the first aspect, wherein the control means controls the output shaft of the motor after a predetermined time has elapsed since the winding biasing force was increased. It is characterized in that it is reversely rotated so that the winding biasing force is reduced.

  In the webbing take-up device according to claim 2, a predetermined time elapses after the output shaft of the motor is rotated forward and the take-up biasing force of the spring is increased (for example, after excessive slack as described above is removed). Further, the output shaft of the motor is reversed and the winding urging force of the spring acting on the winding shaft is reduced. Thereby, passenger comfort is ensured again. In addition, since the drive of the motor is controlled based on the elapsed time since the winding biasing force is increased as described above, the configuration is simple.

  The webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the first aspect, wherein the control means increases the take-up biasing force, and then the webbing taken out is set by a set amount. At the time of winding, the output shaft of the motor is reversed so that the winding biasing force is reduced.

  4. The webbing take-up device according to claim 3, wherein when the webbing is taken up by a set amount after the output shaft of the motor is rotated forward and the winding biasing force of the spring is increased, the output shaft of the motor is taken up. Is reversed and the winding biasing force of the spring acting on the winding shaft is reduced. Thereby, passenger comfort is ensured again.

  The webbing take-up device according to a fourth aspect of the present invention is the webbing take-up device according to the third aspect, wherein when the set amount is taken up, the take-up amount of the webbing onto the take-up shaft is small. The maximum winding amount is reached.

  In the webbing take-up device according to claim 4, after the output shaft of the motor is rotated forward and the take-up biasing force of the spring is increased, the take-up amount of the webbing to the take-up shaft reaches the maximum take-up amount. At that time (when excessive slack as described above is completely removed), the output shaft of the motor is reversed and the winding urging force of the spring acting on the winding shaft is reduced. Therefore, the excessive slack can be reliably removed.

  A webbing take-up device according to a fifth aspect of the invention corresponds to a take-up shaft on which a webbing for occupant restraint is taken up and connected to the take-up shaft, and corresponds to the occupant non-compressibility in the webbing wearing state of the occupant. An urging member that urges the take-up shaft in the webbing take-up direction with an urging force and an output shaft are connected to the take-up shaft, and the take-up shaft is rotated in the webbing take-up direction with a driving force. The maximum winding amount of the webbing on the winding shaft when the occupant is mounted on the motor and the webbing is detected, and the webbing is pulled out by a predetermined amount or more with respect to the maximum winding amount, and the state is maintained for a predetermined time. Control means for rotating the output shaft of the motor when the motor is maintained is characterized.

  In the webbing take-up device according to the fifth aspect, the urging force of the urging member that urges the take-up shaft in the webbing take-up direction corresponds to the occupant non-compressing property when the occupant is mounted on the webbing. Therefore, passenger comfort can be ensured.

  Further, when the occupant wears the webbing, the maximum winding amount of the webbing on the winding shaft in the mounted state (that is, the winding amount of the webbing on the winding shaft in a state where the so-called slack is minimized) is controlled. Detected by means. Then, when the webbing is pulled out a predetermined amount or more with respect to the maximum winding amount and the state is maintained for a predetermined time, the control means determines that, for example, excessive slack has occurred, and the motor output shaft Rotate. The winding shaft is rotated in the webbing winding direction by the rotation of the output shaft, and the webbing is wound around the winding shaft. Thereby, the excessive slack is removed, and good restraint by webbing is ensured.

  Thus, in the webbing retractor according to the fifth aspect, the comfort and restraint of the occupant can be achieved.

  A webbing take-up device according to a sixth aspect of the present invention is the webbing take-up device according to the fifth aspect, wherein the control means controls the output shaft of the motor when the webbing is wound by a set amount. It is characterized by being stopped.

  In the webbing take-up device according to the sixth aspect of the invention, the output shaft of the motor is stopped when the webbing is wound by a set amount by the rotation of the output shaft of the motor. In this state, only the urging force of the urging member corresponding to the occupant non-compressibility acts on the winding shaft. Therefore, passenger comfort is ensured again.

  The webbing take-up device according to a seventh aspect of the present invention is the webbing take-up device according to the sixth aspect, wherein the timing at which the control means stops the rotation of the output shaft is the winding of the webbing onto the take-up shaft. The take-up amount is the time when the maximum take-up amount is reached.

  In the webbing take-up device according to the seventh aspect, the output shaft of the motor is stopped when the winding amount of the webbing on the winding shaft reaches the maximum winding amount. Therefore, the excessive slack can be reliably removed.

  The webbing take-up device according to an eighth aspect of the present invention is the webbing take-up device according to the sixth aspect, wherein the control means stops the rotation of the output shaft at a time when a predetermined time has elapsed from the start of the rotation. It is characterized by being.

  In the webbing retractor according to the eighth aspect, the rotation of the output shaft is stopped after a predetermined time has elapsed since the output shaft of the motor was rotated. Since the timing for stopping the motor is controlled based on time in this way, the configuration is simple.

  As described above, the webbing retractor according to the present invention can achieve both passenger comfort and restraint.

<First Embodiment>
FIG. 1 is an exploded perspective view showing a configuration of a webbing take-up device 10 according to a first embodiment of the present invention. FIG. 2 is a side sectional view showing the configuration of the webbing take-up device 10.

  The webbing take-up device 10 includes a take-up shaft 12. The take-up shaft 12 is rotatably supported by the frame 14, and the base end portion of the webbing 13 (not shown in FIG. 1) is locked, and the webbing 13 is taken up by the rotation of the take-up shaft 12. Or withdrawn.

  An adapter 16 is connected to one end of the winding shaft 12 outside the frame 14, and a cover 18 and a box-shaped base 20 are attached to the side of the frame 14. The adapter 16 passes through the base 20 and always rotates integrally with the winding shaft 12.

  In the base 20, a mainspring 22 as a spring and a spring holding box 24 are arranged. The main spring 22 has an inner end locked to the adapter 16 and an outer end locked to a spring holding box 24 to urge the winding shaft 12 in the webbing winding direction. On the other hand, the spring holding box 24 that locks the outer end portion of the mainspring spring 22 can be rotated coaxially and forward and backward with the adapter 16 in a state in which the mainspring spring 22 is accommodated therein (relative to the adapter 16). ) It is supported by the base 20. For this reason, when the spring holding box 24 rotates in the forward and reverse directions, the locking position of the outer end portion of the mainspring spring 22, that is, the setting position of the mainspring spring 22 can be changed. The winding biasing force applied to the shaft 12 can be adjusted (changed).

  In this case, when the spring holding box 24 is rotated by a specific amount (for example, 10 rotations) in the positive direction (direction of arrow A in FIG. 1), the winding biasing force applied to the winding shaft 12 by the mainspring spring 22 increases ( Torque up). On the other hand, when the spring holding box 24 is rotated by the specified amount in the reverse direction (the direction of arrow B in FIG. 1), the winding biasing force applied to the winding shaft 12 by the mainspring spring 22 is reduced (torque down). It becomes a state.

  The winding biasing force of the mainspring spring 22 in the above torque-up state is set to a level comparable to the winding biasing force of the mainspring spring in a normal webbing winding device. Further, the winding urging force of the mainspring 22 in the torque-down state is set corresponding to the occupant non-compressibility in the occupant's webbing wearing state.

  On the outer peripheral edge of the spring holding box 24, a worm tooth portion 26 is formed to constitute a so-called worm wheel. A worm gear 30 is engaged with the worm tooth portion 26 of the spring holding box 24. The worm gear 30 is supported at one end of a shaft 32, and a spur gear 34 is attached to the other end of the shaft 32. The spur gear 34 meshes with a spur gear 38 attached to the output shaft 35 of the motor 36.

  The motor 36 is fixed to the base 20 by a stay 37, and the spur gear 34, the spur gear 38 and the like are covered with a cover 39. Thus, when the motor 36 is driven, the driving force is transmitted through the spur gear 38, the spur gear 34, the worm gear 30, and the worm tooth portion 26, and the spring holding box 24 is rotated.

  In this case, when the output shaft 35 of the motor 36 is rotated forward, the spring holding box 24 is rotated in the forward direction, and when the output shaft 35 of the motor 36 is reversed, the spring holding box 24 is rotated in the reverse direction. Yes.

  In the webbing take-up device 10, when the webbing 13 is fully stored, the spring holding box 24 is rotated by a specific amount in the reverse direction by the operation of the motor 36, so that the mainspring spring 22 applies the take-up shaft 12. The winding urging force is reduced.

  On the other hand, the webbing take-up device 10 includes a driver 46 and an ECU 48 that constitute control means. The ECU 48 stores a drive control program according to the first embodiment of the present invention. In addition, the motor 36 is electrically connected to a battery 50 mounted on the vehicle via a driver 46, and the current from the battery 50 flows to the motor 36 via the driver 46, so that the motor 36 has a driving force. Thus, the output shaft 35 is configured to rotate forward or reverse. The driver 46 is connected to the ECU 48, and the ECU 48 controls the presence / absence of power supply to the motor 36 via the driver 46 and the direction of the supply current. In addition, in this case, the ECU 48 can detect the rotation amount of the output shaft 35 based on the energization time of the motor 36 and the like.

  The ECU 48 is connected to a buckle switch 52 as a control means for detecting whether or not a tongue plate provided on the webbing 13 is connected to a buckle device (both not shown). When the tongue plate is connected to the buckle device, the buckle switch 52 outputs an H level signal indicating the switch ON state to the ECU 48, and when the tongue plate is released from the buckle device, the switch OFF state. Is output to the ECU 48.

  Furthermore, the ECU 48 is connected to a rotation angle detection sensor 54 (in the first embodiment, a Hall IC) that constitutes a control means. The rotation angle detection sensor 54 corresponds to a magnet 56 provided at one end of the winding shaft 12. When the magnet 56 repeatedly passes in the vicinity of the rotation angle detection sensor 54 by the rotation of the winding shaft 12, the magnet The magnetism generated by 56 is detected and a predetermined electrical signal is output to the ECU 48.

  In this case, the ECU 48 detects the number of rotations of the winding shaft 12 based on the electrical signal output from the rotation angle detection sensor 54 and calculates the amount of winding of the webbing 13 to the winding shaft 12 from the detected number of rotations. It is designed to detect (measure).

  Here, in the webbing take-up device 10, the ECU 48 causes the maximum take-up amount P0 of the webbing 13 to the take-up shaft 12 (that is, so-called slack to be minimized) when the occupant is wearing the webbing. The amount of winding on the winding shaft 12) is detected, and the detected maximum winding amount P0 is stored (data is saved).

  In addition, in this case, the ECU 48 always detects the amount of winding of the webbing 13 onto the winding shaft 12 in the mounted state, and when a larger maximum winding amount P0 is detected (for example, sliding between the webbing 13 and the tongue plate). When the slack generated by the dynamic resistance or the like is eliminated and the webbing 13 is further wound on the winding shaft 12), the stored data is rewritten (data is updated).

  When the webbing 13 is pulled out by a predetermined amount L or more with respect to the maximum winding amount P0 stored at a certain time, and the state is maintained for a predetermined time, the ECU 48 determines that “excessive slack has occurred”. And a control signal for causing the output shaft 35 of the motor 36 to rotate forward is output to the driver 46. Based on this control signal, the driver 46 operates to drive the motor 36.

  Next, the operation of the first embodiment of the present invention will be described with reference to the flowchart of the drive control program shown in FIG.

  In the webbing take-up device 10 configured as described above, when the occupant wears the webbing 13 (when the webbing 13 is fully stored in the webbing take-up device 10), the winding of the spring 22 acting on the take-up shaft 12 is performed. The mounting force is reduced. Therefore, the passenger can easily pull out the webbing 13 with a light force. The tongue plate provided on the webbing 13 is mounted (held) on the buckle device, so that the occupant is in a webbing mounted state. In this state, the winding biasing force of the mainspring spring 22 is reduced as described above. Therefore, the excessive pressure feeling of the webbing 13 is reduced or eliminated, and passenger comfort is ensured.

  When the tongue plate is attached (held) to the buckle device as described above, the buckle switch 52 is turned on (step 58). Accordingly, the ECU 48 determines that the occupant has mounted the webbing 13 and proceeds to step 60.

  In step 60, the ECU 48 detects the maximum winding amount P0 of the webbing 13 around the winding shaft 12 based on the electrical signal from the rotation angle detection sensor 54, and stores the detected maximum winding amount P0. When the processing in step 60 is completed, the process proceeds to next step 62.

  In step 62, for example, the ECU 48 determines whether or not the webbing 13 is pulled out from the winding shaft 12 by a predetermined amount L or more due to the occupant bending forward. That is, the ECU 48 determines whether or not the webbing 13 has been pulled out by a predetermined amount L or more with respect to the maximum winding amount P0 stored in step 60 (the winding amount of the webbing 13 to the winding shaft 12 at this time is stored). Whether or not the value is a value reduced by a predetermined amount L or more than the maximum winding amount P0 is determined based on an electrical signal from the rotation angle detection sensor 54. The process proceeds to the next step 64 only when this determination is affirmed.

  In step 64, the ECU 48 determines whether or not the state in which the webbing 13 is pulled out by a predetermined amount L or more as described above is maintained for a predetermined time, that is, whether excessive slack has occurred in the webbing 13 in the mounted state. To do. The process proceeds to the next step 66 only when this determination is affirmed.

  In step 66, the ECU 48 outputs a control signal for causing the output shaft 35 of the motor 36 to rotate forward to the driver 46. For this reason, the driver 46 rotates the output shaft 35 of the motor 36 forward based on this control signal. Thereby, the forward rotation of the output shaft 35 is transmitted through the spur gear 38, the spur gear 34, the worm gear 30, and the worm tooth portion 26, and the spring holding box 24 is rotated in the forward direction. When the processing in step 66 is completed, the routine proceeds to the next step 68.

  In step 68, the ECU 48 determines whether or not the output shaft 35 of the motor 36 has rotated forward a predetermined amount. That is, the ECU 48 determines whether or not the winding biasing force applied to the winding shaft 12 by the mainspring spring 22 has increased to a predetermined value (torque up) by rotating the spring holding box 24 by a specific amount in the forward direction. Is done. The process proceeds to the next step 70 only when this determination is affirmed.

  In step 70, the ECU 48 outputs a control signal for stopping the forward rotation of the motor 36 to the driver 46. For this reason, the driver 46 stops the output shaft 35 of the motor 36 based on this control signal. In this state, since the winding biasing force applied to the winding shaft 12 by the mainspring 22 is increased as described above, the winding shaft 12 is rotated in the winding direction by the winding biasing force. The webbing 13 is wound around the winding shaft 12.

  Even if the occupant maintains a forward bending posture with the winding urging force of the mainspring 22 increased as described above, the winding urging force of the mainspring spring 22 takes up the winding of the mainspring in a normal webbing winding device. The load is not generated so as to pull back the occupant only at the same level as the urging force. For this reason, the passenger is not discomforted, and conversely, a warning can be given to the passenger who maintains an inappropriate driving posture. When the processing in step 70 is completed, the process proceeds to next step 72.

  In step 72, the ECU 48 determines whether or not a predetermined time has elapsed since the output shaft 35 of the motor 36 stopped. That is, the ECU 48 determines whether or not the time necessary for removing the excessive slack by the increased winding biasing force has elapsed. If this determination is affirmed, the excessive slack has been removed, so that good restraint for the passenger is ensured. When the processing in step 72 is completed, the process proceeds to next step 74.

  In step 74, the ECU 48 outputs a control signal for reversing the output shaft 35 of the motor 36 to the driver 46. For this reason, the driver 46 reversely rotates the output shaft 35 of the motor 36 based on this control signal. Thus, the reverse rotation of the output shaft 35 is transmitted through the spur gear 38, the spur gear 34, the worm gear 30, and the worm tooth portion 26, and the spring holding box 24 is rotated in the reverse direction. When the processing in step 74 is completed, the process proceeds to next step 76.

  In step 76, the ECU 48 determines whether or not the output shaft 35 of the motor 36 has been reversed by a predetermined amount. That is, the ECU 48 determines whether or not the winding urging force applied to the winding shaft 12 by the mainspring spring 22 is reduced to a predetermined value (torque down) by rotating the spring holding box 24 by a specific amount in the reverse direction. Is done. Only when this determination is affirmed, the routine proceeds to the next step 78.

  In step 78, the ECU 48 outputs a control signal for stopping the reverse rotation of the motor 36 to the driver 46. For this reason, the driver 46 stops the output shaft 35 of the motor 36 based on this control signal. In this state, the winding biasing force applied to the winding shaft 12 by the mainspring spring 22 is reduced as described above, so that excessive feeling of pressure by the webbing 13 is reduced or eliminated, and passenger comfort is improved. Will be secured again. When the processing in step 78 is completed, the process proceeds to next step 80.

  In step 80, the ECU 48 determines whether or not the tongue plate is released from the buckle device and the buckle switch 52 is turned off. That is, the ECU 48 determines whether or not the occupant has released the wearing state of the webbing 13. If this determination is negative, the process returns to step 60 and the above-described processing is repeated. On the other hand, if this determination is affirmed, the drive control program according to the first embodiment of the present invention is terminated.

  As described above, the webbing retractor 10 according to the first embodiment can achieve both passenger comfort and restraint.

  Moreover, in the webbing take-up device 10 according to the first embodiment, the ECU 48 increases the take-up biasing force of the mainspring spring 22 (after step 70), and when a predetermined time has elapsed in step 72, the motor 48 36 is reversed (shifted to step 74), the configuration is simple.

  Instead of step 72, a step of shifting to step 74 when the webbing 13 is wound on the winding shaft 12 by a set amount (for example, an amount set based on the pulling-out amount of the webbing 13). May be provided.

Instead of step 72, a step of shifting to step 74 may be provided when the winding amount of the webbing 13 to the winding shaft 12 reaches the maximum winding amount P0. In this case, the excessive slack can be reliably removed.
<Second Embodiment>
Next, a second embodiment of the present invention will be described. In addition, about the structure and operation | movement fundamentally the same as the said 1st Embodiment, the same code | symbol as the said 1st Embodiment is attached | subjected and the description is abbreviate | omitted.

  FIG. 4 is a front sectional view showing the configuration of the webbing retractor 100 according to the second embodiment of the present invention.

  The webbing take-up device 100 includes a take-up shaft 102. The winding shaft 102 is rotatably supported by the frame 104 and the base end portion of the webbing 106 is locked. The webbing 106 is wound and pulled out by the rotation of the winding shaft 102.

  One end of the winding shaft 102 protrudes to the outside of the frame 104, and a case 108 is attached to the side of the frame 104. Inside the case 108, a mainspring 110 as an urging member is disposed. The main spring 110 has an inner end locked to the winding shaft 102 and an outer end locked to the case 108. The spring spring 110 urges the winding shaft 102 in the webbing winding direction.

  The biasing force of the mainspring spring 110 (based on the winding force of the webbing 106) is set to be relatively weak enough to eliminate the slackness of the webbing 106 worn by the passenger. In other words, the urging force of the mainspring spring 110 is set so as to have a strength corresponding to the occupant non-compressibility when the webbing 106 is attached, and the webbing 106 pulled out from the take-up shaft 102 resists frictional force and the like. The strength to wind up to the end is not required.

  On the other hand, a motor 112 is disposed below the winding shaft 102. A gear 116 is coaxially and integrally provided on the output shaft 114 of the motor 112. A gear 118 having a larger diameter than that of the gear 116 is disposed above the gear 116 in the radial direction. The gear 118 meshes with the gear 116 while being rotatably supported around an axis parallel to the winding shaft 102 by the frame 104 and a support plate 119 attached to the frame 104. A gear 120 having a smaller diameter than the gear 118 is coaxially and integrally provided on the side of the gear 118 in the axial direction.

  Furthermore, a clutch 122 is provided above the gear 120 in the radial direction. The clutch 120 includes an external gear 124 formed in a ring shape. The gear 124 is provided so as to be coaxial with the take-up shaft 102 and rotatable relative to the take-up shaft 102 while being engaged with the gear 120, and both ends in the axial direction are closed by disk-like members (not shown). A cylindrical adapter 126 is provided coaxially with the take-up shaft 102 inside the gear 124. The adapter 126 is integrally connected to the take-up shaft 102 so that the disc-like member and thus the gear 124 can be rotated around the take-up shaft 102 in a state where the both ends of the gear 124 are closed. It is pivotally supported.

  A connecting member (not shown) such as a pawl that swings due to centrifugal force is accommodated inside the gear 124. For example, the connecting member is supported by the disk-shaped member and rotates integrally with the gear 124.

  Here, in this clutch 122, the rotational force of the output shaft 114 of the motor 112 is transmitted to the gear 124 through the gear 116, the gear 118, and the gear 120 (the output shaft 114 and the gear 124 always rotate in synchronization). When the output shaft 114 of the motor 112 rotates, the gear 124 rotates in the winding direction. When the gear 124 rotates in the winding direction, the connecting member is mechanically coupled to the outer peripheral surface of the adapter 126 so that the gear 124 and the adapter 126 are integrally connected. Thereby, the rotation of the gear 124 in the winding direction (rotation of the motor 112) is transmitted to the winding shaft 102 via the adapter 126. Thereby, the winding shaft 102 is rotated in the winding direction, and the webbing 106 is wound around the winding shaft 102.

  On the other hand, when the output shaft 114 of the motor 112 stops, the mechanical coupling of the connecting member to the adapter 126 is released, and the clutch 122 is in a released state.

  In the webbing take-up device 100, the rotational force of the take-up shaft 102 caused by the rotational force of the motor 112 is relatively low torque (the webbing 106 drawn from the take-up shaft 102 resists frictional force and the like). It is set so that it can be wound up to the end).

  On the other hand, the webbing take-up device 100 includes a driver 46 and an ECU 128 that constitute control means. The ECU 128 has basically the same configuration as the ECU 48 according to the first embodiment. The ECU 128 stores a drive control program according to the second embodiment of the present invention. Yes. Further, the motor 112 is electrically connected to the battery 50 mounted on the vehicle via the driver 46, and the driving of the motor 112 is controlled by the ECU 128 and the driver 46 as in the first embodiment. It has come to be.

  Further, the ECU 128 is connected to the buckle switch 52 and the rotation angle detection sensor 54 (in the second embodiment, a Hall IC). The rotation angle detection sensor 54 corresponds to the magnet 130 provided at the other end of the winding shaft 102 as in the first embodiment, and the ECU 128 is output from the rotation angle detection sensor 54. The rotational speed of the winding shaft 102 is detected based on the electrical signal, and the winding amount of the webbing 106 to the winding shaft 102 is detected (measured) from the detected rotational speed.

  Here, in the webbing take-up device 100, the ECU 128 always detects the maximum take-up amount P0 of the webbing 106 on the take-up shaft 102 when the occupant is wearing the webbing, as in the first embodiment. The detected maximum winding amount P0 is stored.

  When the webbing 106 is pulled out by a predetermined amount L or more with respect to the maximum winding amount P0 stored at a certain point and the state is maintained for a predetermined time, the ECU 128 determines that “excessive slack has occurred”. And a control signal for rotating the output shaft 114 of the motor 112 by a predetermined amount is output to the driver 46. Based on this control signal, the driver 46 operates to drive the motor 112.

  Next, the operation of the second embodiment of the present invention will be described with reference to the flowchart of the drive control program shown in FIG.

  In the webbing take-up device 100 configured as described above, the urging force of the spring 22 that urges the take-up shaft 102 in the take-up direction is set to be relatively weak enough to eliminate the slack of the webbing 106 worn by the occupant. Therefore, the occupant can easily pull out the webbing 106 with a light force. Then, the tongue plate provided on the webbing 106 is attached (held) to the buckle device (both not shown), so that the occupant is in the webbing wearing state. In this state, the winding of the mainspring spring 110 is wound as described above. Since the power is set weak, passenger comfort is ensured.

When the tongue plate is attached to the buckle device as described above, the buckle switch 52 is turned on (step 132). As a result, the ECU 128 determines that the occupant has mounted the webbing 106, and the process proceeds to step 134. In step 134, the ECU 128 determines the maximum amount of the webbing 106 to the winding shaft 102 based on the electrical signal from the rotation angle detection sensor 54. The winding amount P0 is detected, and the detected maximum winding amount P0 is stored. When the processing at step 134 is completed, the routine proceeds to the next step 136.

  In step 136, for example, the ECU 128 determines whether or not the webbing 106 is pulled out from the winding shaft 102 by a predetermined amount L or more due to the occupant bending forward. That is, the ECU 128 determines whether or not the webbing 106 has been pulled out by a predetermined amount L or more with respect to the maximum winding amount P0 stored in step 134 (the winding amount of the webbing 106 to the winding shaft 102 at this time is stored). Whether or not the value is a value reduced by a predetermined amount L or more than the maximum winding amount P0 is determined based on an electrical signal from the rotation angle detection sensor 54. Only when this determination is affirmed, the process proceeds to the next step 138.

  In step 138, the ECU 128 determines whether or not the state in which the webbing 106 is pulled out by a predetermined amount L or more is maintained for a predetermined time, that is, whether excessive slack has occurred in the webbing 106 in the mounted state. The process proceeds to the next step 140 only when this determination is affirmed.

  In step 140, the ECU 128 outputs a control signal for rotating the output shaft 114 of the motor 112 to the driver 46. For this reason, the driver 46 rotates the output shaft 114 of the motor 112 based on this control signal. Thereby, the rotation of the output shaft 114 is transmitted to the gear 124 of the clutch 122 via the gear 116, the gear 118, and the gear 120, and the gear 124 is rotated in the winding direction. As a result, the clutch 122 is in a connected state, the driving force of the motor 112 is transmitted to the winding shaft 102 via the clutch 122, and the winding shaft 102 is rotated in the winding direction. For this reason, the webbing 106 is wound around the winding shaft 102. When the processing in step 140 is completed, the process proceeds to next step 142.

  In step 142, the ECU 128 determines whether or not the winding amount of the webbing 106 around the winding shaft 102 has reached the maximum winding amount P0 based on the electrical signal from the rotation angle detection sensor 54. That is, the ECU 128 determines whether or not the excessive slack has been completely removed. If this determination is affirmed, the excessive slack has been removed, so that good restraint for the passenger is ensured. When the processing in step 142 is completed, the process proceeds to next step 144.

  In step 144, the ECU 128 outputs a control signal for stopping the rotation of the motor 112 to the driver 46. For this reason, the driver 46 stops the output shaft 114 of the motor 112 based on this control signal. As a result, the mechanical coupling of the connecting member (not shown) to the adapter 126 is released, and the clutch 122 is released. In this state, since only the urging force of the mainspring spring 110 acts on the winding shaft 102, the comfort of the passenger is ensured again. When the processing in step 144 is completed, the process proceeds to next step 146.

  In step 146, the ECU 128 determines whether or not the tongue plate is released from the buckle device and the buckle switch 52 is turned off. That is, ECU 128 determines whether or not the occupant has released the webbing 106 from being worn. If this determination is negative, the process returns to step 134 and the above-described processing is repeated. On the other hand, if this determination is affirmed, the drive control program according to the second embodiment of the present invention is terminated.

  As described above, the webbing retractor 100 according to the second embodiment can achieve both passenger comfort and restraint.

  In the second embodiment, in step 142, when the winding amount of the webbing 106 to the winding shaft 102 reaches the maximum winding amount P0, the process shifts to step 144. Not limited to step 142, a step of shifting to step 144 may be provided when a predetermined time elapses after the output shaft 114 of the motor 112 starts rotating. That is, the ECU 128 may determine whether or not the excessive slack has been removed based on the rotation time of the output shaft 114. Further, instead of step 142, when the webbing 106 is wound around the winding shaft 102 by a set amount (for example, an amount set based on the pull-out amount of the webbing 106, etc.), the process proceeds to step 144. May be provided.

  In the second embodiment, when an external force exceeding a predetermined value against the winding of the webbing 106 is applied during the winding of the webbing 106 by the rotation of the motor 112, the gear 124 of the clutch 122 is disengaged. The adapter 126, that is, the winding shaft 102, may be configured to idle (so-called overload mechanism). In this case, in step 140, even if the occupant maintains the forward bending posture in a state where the webbing 106 is wound by the rotation of the motor 112, the overload mechanism operates to pull the occupant back. No load is generated, and it is possible to prevent the passenger from feeling uncomfortable.

1 is an exploded perspective view showing a configuration of a webbing take-up device according to a first embodiment of the present invention. 1 is a side sectional view showing a configuration of a webbing take-up device according to a first embodiment of the present invention. It is a flowchart which shows the control procedure of the control means of the webbing winding device concerning a 1st embodiment of the present invention. It is front sectional drawing which shows the structure of the webbing winding apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the control procedure of the control means of the webbing winding device concerning a 2nd embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Webbing winding device 12 Winding shaft 13 Webbing 22 Spring spring (spring)
24 Spring holding box 35 Output shaft 36 Motor 46 Driver (control means)
48 ECU (control means)
52 Buckle switch (control means)
54 Rotation angle detection sensor (control means)
56 Magnet (control means)
DESCRIPTION OF SYMBOLS 100 Webbing winding device 102 Winding shaft 106 Webbing 110 Spring spring (urging member)
112 motor 114 output shaft 128 ECU (control means)
130 Magnet (control means)

Claims (8)

A spring that is connected at one end to a take-up shaft from which a webbing for occupant restraint is taken up and pulled out, and applies a winding biasing force to the take-up shaft;
The other end of the spring is locked and rotatably provided, and the winding biasing force by the spring is increased by rotating a specific amount in the forward direction, and the specific amount rotates in the reverse direction. A spring holding box that reduces the winding biasing force by the spring,
An output shaft connected to the spring holding box; and a motor that rotates the spring holding box in the forward direction by forward rotation of the output shaft, and rotates the spring holding box in the reverse direction by reverse rotation of the output shaft;
The maximum winding amount of the webbing onto the winding shaft in the state where the occupant is mounted is detected, and the webbing is pulled out by a predetermined amount or more with respect to the maximum winding amount, and the state is maintained for a predetermined time. In such a case, the control means for causing the output shaft of the motor to rotate forward to increase the winding biasing force,
A webbing take-up device comprising:   The said control means reversely rotates the said output shaft of the said motor after predetermined time passes after increasing the said winding urging | biasing force, The said winding urging | biasing force is made into the state reduced. Webbing take-up device.   The control means reverses the output shaft of the motor and reduces the winding biasing force when the drawn webbing is wound by a set amount after increasing the winding biasing force. 2. The webbing take-up device according to claim 1, wherein the webbing take-up device is in a state.   4. The webbing according to claim 3, wherein the time point when the set amount is wound is a time point when the winding amount of the webbing to the winding shaft reaches the maximum winding amount. Winding device. A take-up shaft on which a webbing for occupant restraint is taken up and pulled out;
An urging member coupled to the take-up shaft and urging the take-up shaft in the webbing take-up direction with an urging force corresponding to an occupant non-compressibility in the webbing wearing state of the occupant;
An output shaft connected to the winding shaft, and a motor that rotates the winding shaft in the webbing winding direction with a driving force;
The maximum winding amount of the webbing onto the winding shaft in the state where the occupant is mounted is detected, and the webbing is pulled out by a predetermined amount or more with respect to the maximum winding amount, and the state is maintained for a predetermined time. A control means for rotating the output shaft of the motor;
A webbing take-up device comprising:   6. The webbing take-up device according to claim 5, wherein the control means stops the output shaft of the motor when the webbing is taken up by a set amount.   The timing at which the control means stops the rotation of the output shaft is a point in time when the winding amount of the webbing around the winding shaft reaches the maximum winding amount. The webbing take-up device described.   The webbing retractor according to claim 6, wherein the timing at which the control means stops the rotation of the output shaft is a time when a predetermined time has elapsed from the start of the rotation.

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