JP2006199116A - Webbing take-up device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a comfortable webbing pulling property without obstructing the function of a tension reducer. <P>SOLUTION: When an occupant pulls a webbing, a control means drives a motor. Because pulling of the webbing is assisted by applying a predetermined torque directed to a webbing pulling direction to a take-up shaft, the webbing can be pulled by a light force. After the occupant wears the webbing, the control means stops the motor, and turns on the tension reducer, so as to reduce an energizing force of an energizing member acting on the take-up shaft. Thereby, a take-up force acting on the webbing is reduced, so as to prevent a feeling of oppression to the occupants wearing the webbing. When the occupants releases the wearing condition of the webbing, the control means turns off the tension reducer. Therefore, the energizing force of the energizing member acts on the winding shaft, and the shaft is rotated in the webbing take-up direction by the energizing force, so as to take up and accommodate the webbing by the take-up shaft. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a webbing retractor constituting a seat belt device for restraining an occupant.

  A seat belt device for restraining an occupant includes a webbing take-up device. Some webbing take-up devices include a tension reducer for reducing or eliminating excessive feeling of pressure when the webbing is mounted (see, for example, Patent Document 1).

  The webbing take-up device (tension reducer) disclosed in the above-mentioned patent document includes two types of springs (strong and small). One end of the weak spring is connected to the winding shaft, and the other end is connected to the strong spring through a gear spring. The other end of the strong spring is locked to the case (cover). That is, the winding shaft, the weak spring, the gear spring, and the strong spring are connected in series, and the winding shaft is urged in the webbing winding direction by these springs. Further, a pawl lever is disposed in the vicinity of the gear spring so that the pawl lever can be engaged with the gear spring to prevent its rotation. The pawl lever operates in conjunction with the operation of the solenoid or the opening / closing of the vehicle door.

  In the webbing take-up device configured as described above, when the occupant wears the webbing, the pawl lever is actuated by the aforementioned actuation mechanism to prevent the gear spring from rotating. For this reason, the urging force in the webbing winding direction by the strong spring does not act on the winding shaft, and the webbing is pulled only by the weak spring. Therefore, the occupant is in a webbing wearing state without a feeling of pressure. On the other hand, when the occupant releases the wearing of the webbing, the rotation prevention of the gear spring by the pawl lever is released. For this reason, the urging force in the webbing take-up direction by the strong spring spring acts on the take-up shaft, and the webbing is quickly taken up by the strong spring spring.

  Thus, in the webbing take-up device having the above-described configuration, it is possible to ensure the comfort of the occupant in the webbing wearing state, and it is possible to wind up and store the webbing well to the end.

However, in the webbing take-up device configured as described above, when the occupant pulls out the stored webbing for wearing the webbing, a biasing force in the webbing take-up direction by the strong spring is applied to the take-up shaft. For this reason, there is a problem that the webbing is pulled out from the stored state, and further improvement has been demanded.
Japanese Utility Model Publication No. 05-071067

  The present invention has been made in view of the above facts, and an object of the present invention is to provide a webbing take-up device that can ensure a comfortable webbing pull-out property without impeding the function of the tension reducer.

  In order to solve the above problems, a webbing take-up device according to a first aspect of the present invention includes a take-up shaft on which a webbing for restraining an occupant is wound so as to be able to be taken out and pulled out, and a predetermined biasing force on the take-up shaft. With the urging member that urges in the webbing take-up direction, the predetermined urging force of the urging member is reduced and applied to the take-up shaft by being turned on, and is turned off. A tension reducer that releases the reduced state, a motor that is connected to the take-up shaft and applies a predetermined torque directed to the take-up shaft to the take-up shaft by a driving force, and when an occupant pulls out the webbing The motor is driven, and when the occupant wears the webbing, the motor is stopped and the tension reducer is turned on, and the occupant is wearing the webbing. Upon release is characterized by comprising a control means for said tension reducer in the OFF state.

  When the occupant pulls out the webbing stored in the webbing take-up device, the control means drives the motor. For this reason, a predetermined torque directed in the webbing pull-out direction is applied to the take-up shaft (torque against a predetermined urging force of the urging member is applied to the take-up shaft). As a result, the webbing pull-out is assisted, so that the occupant can pull out the webbing with a light force.

  On the other hand, when the occupant wears the webbing, the control means stops the motor and turns on the tension reducer. That is, the winding force of the winding shaft caused by the predetermined biasing force of the biasing member acts on the webbing in the mounted state due to the motor being stopped, but at this time, the tension reducer is turned on to The predetermined urging force of the urging member acting on the shaft is reduced. Thereby, the winding force acting on the webbing is reduced, and it is possible to prevent the occupant wearing the webbing from feeling compressed.

  On the other hand, when the occupant releases the wearing state of the webbing, the control means turns off the tension reducer. Therefore, a predetermined biasing force of the biasing member acts on the winding shaft, and the winding shaft is rotated in the webbing winding direction by the biasing force, whereby the webbing is wound around the winding shaft and stored. Is done.

  Thus, in the webbing take-up device according to the first aspect, it is possible to ensure a comfortable webbing pull-out property without inhibiting the function of the tension reducer.

  A 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 tension reducer is connected to the take-up shaft and the take-up shaft rotates in the webbing pull-out direction. And a rotating body that rotates in one direction and rotates in the other direction when the winding shaft rotates in the webbing winding direction, and one end connected to the rotating body and rotates integrally with the rotating body. And a pulling direction biasing member that applies a biasing force in the one direction to the rotating body when the rotating body rotates in the other direction with rotation of the other end restricted in the other direction. And restricting means for restricting rotation of the other end of the pull-out direction biasing member in the other direction by being turned on and releasing the rotation restriction by being turned off. It is characterized by

  When the occupant pulls out the webbing stored in the webbing take-up device, the control means drives the motor. For this reason, a predetermined torque directed in the webbing pull-out direction is applied to the take-up shaft (torque against a predetermined urging force of the urging member is applied to the take-up shaft). As a result, the webbing pull-out is assisted, so that the occupant can pull out the webbing with a light force.

  Further, as described above, when the winding shaft rotates in the webbing pull-out direction when the occupant pulls out the webbing, the rotating body connected to the winding shaft rotates in one direction, and one end is connected to the rotating body. The biasing member rotates in one direction integrally with the rotating body.

  On the other hand, when the occupant wears the webbing, the control means stops the motor and turns on the tension reducer. When the tension reducer is turned on, the rotation of the other end of the pull-out direction biasing member in the other direction is restricted by the restricting means. Further, when the occupant wears the webbing as described above (when the webbing is pulled out by the occupant), the winding shaft rotates in the webbing winding direction by a predetermined urging force of the urging member, and the webbing The slack is removed. At this time, as the winding shaft rotates in the webbing winding direction, one end of the rotating body and the drawing direction urging member rotates in the other direction, but the other end of the drawing direction urging member is moved in the other direction by the regulating means. The rotation is regulated. For this reason, an urging force in one direction is applied to one end of the drawing direction urging member, that is, the rotating body, and an urging force in the webbing pulling direction is applied to the winding shaft from the rotating body.

  Therefore, the predetermined biasing force of the biasing member, which is the biasing force in the webbing winding direction, is offset by the biasing force in the pulling direction, and the predetermined biasing force of the biasing member is applied to the winding shaft while being reduced. . Thereby, the webbing winding force of the winding shaft due to the predetermined biasing force of the biasing member is reduced, and it is possible to prevent the occupant wearing the webbing from feeling compressed. In this state, as described above, the webbing winding force of the winding shaft due to the predetermined biasing force of the biasing member is reduced, so that the webbing is pulled out lightly in the mounted state.

  On the other hand, when the occupant releases the wearing state of the webbing, the control means turns off the tension reducer. When the tension reducer is turned off, the restriction of rotation in the other direction of the other end of the pull-out direction biasing member by the restricting means is released. Thereby, the other end of the pulling direction biasing member rotates in the other direction, and the biasing force in the pulling direction disappears, so that the winding shaft is rotated in the webbing winding direction by a predetermined biasing force of the biasing member, Thus, the webbing is wound and stored on the winding shaft.

  Thus, in the webbing retractor according to the second aspect, it is possible to ensure a comfortable webbing pull-out property without hindering the function of the tension reducer.

  The webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the second aspect, wherein the control means is configured to first pull out the webbing after the occupant wears the webbing. The motor is driven, and the motor is stopped when the drawer is released.

  In the webbing take-up device according to claim 3, for example, when the occupant wears the webbing, the webbing is less slack and the take-up shaft cannot sufficiently rotate in the webbing take-up direction (at one end of the pulling direction biasing member). Even when the urging force in one direction cannot be sufficiently applied and the tension reducer does not function), when the webbing in the mounted state is first pulled out, such as when the occupant takes a forward bending posture, the control means The motor is driven in response to the drawer. As a result, a predetermined torque directed in the webbing pull-out direction is applied to the take-up shaft, and the webbing pull-out is assisted, so that it is possible to prevent a passenger from taking a pre-bent posture from being compressed.

  When the webbing withdrawal is released, the winding shaft is rotated in the webbing winding direction by a predetermined biasing force of the biasing member, and the slack of the webbing is removed. At this time, by the rotation of the winding shaft in the webbing winding direction, an urging force in one direction is applied to one end of the drawing direction urging member, that is, the rotating body, and the tension reducer functions. This prevents the passenger wearing the webbing from feeling pressured and reduces the second and subsequent drawers of the webbing in the worn state.

  A webbing take-up device according to a fourth aspect of the present invention is the webbing take-up device according to the first aspect, wherein the tension reducer is connected to the take-up shaft and the take-up shaft rotates in the webbing pull-out direction. The rotating body rotates in one direction, and when the winding shaft rotates in the webbing winding direction, the rotating body rotates in the other direction, and is supported by the rotating body in a state where its rotation is restricted. When the rotating body rotates, a drag applying member that slides on the rotating body to apply a predetermined drag to the rotation of the rotating body, and when the rotating body rotates in the other direction in the on state. And a restricting means for restricting the rotation of the drag application member.

  In the webbing retractor according to the fourth aspect, when the occupant pulls out the webbing stored in the webbing retractor, the control means drives the motor. For this reason, a predetermined torque directed in the webbing pull-out direction is applied to the take-up shaft (torque against a predetermined urging force of the urging member is applied to the take-up shaft). As a result, the webbing pull-out is assisted, so that the occupant can pull out the webbing with a light force.

  Also, when the occupant pulls out the webbing as described above and the winding shaft rotates in the webbing pull-out direction, the rotating body connected to the winding shaft rotates in one direction, and the drag application member supported by the rotating body rotates. Rotates in one direction integrally with the body.

  On the other hand, when the occupant wears the webbing, the control means stops the motor and turns on the tension reducer. In this state, when the winding shaft rotates in the webbing winding direction by the predetermined biasing force of the biasing member and the rotating body rotates in the other direction, the rotation of the drag applying member is regulated by the regulating means. When the winding shaft is further rotated in the webbing winding direction and the rotating body is rotated in the other direction in a state where the rotation of the drag applying member is restricted in this way, the drag applying member slides on the rotating body and the rotating body is rotated. A predetermined drag is applied to the rotation in the other direction. For this reason, the predetermined drag is also applied to the rotation of the winding shaft connected to the rotating body in the webbing winding direction. As a result, the predetermined biasing force of the biasing member is applied to the winding shaft. It is given after being reduced (offset) by the drag. Therefore, the webbing winding force of the winding shaft due to the predetermined biasing force of the biasing member is reduced, and it is possible to prevent the occupant wearing the webbing from feeling compressed.

  On the other hand, when the occupant releases the wearing state of the webbing, the control means turns off the tension reducer. In this state, since the rotation of the drag applying member is not restricted by the restricting means, the application of the predetermined drag against the rotation of the rotating body in the other direction is released, and the winding shaft moves in the webbing take-up direction. The application of the predetermined resistance against rotation is also released. Accordingly, the take-up shaft is rotated in the webbing take-up direction by a predetermined urging force of the urging member, whereby the webbing is taken up and stored on the take-up shaft.

  Thus, in the webbing retractor according to the fourth aspect, a comfortable webbing pull-out property can be ensured without hindering the function of the tension reducer.

  The webbing take-up device according to a fifth aspect of the present invention is the webbing take-up device according to the fourth aspect, wherein the control means drives the motor when the webbing is pulled out in the webbing wearing state of the occupant. In addition, the motor is stopped when the drawer is released.

  In the webbing take-up device according to claim 5, when the webbing is pulled out with the occupant wearing the webbing, for example, when the occupant takes a forward bending posture, the control means responds to the withdrawal. Drive the motor. As a result, a predetermined torque directed in the webbing pull-out direction is applied to the take-up shaft, and the webbing pull-out is assisted, so that it is possible to prevent a passenger from taking a pre-bent posture from being compressed.

  The webbing take-up device according to a sixth aspect of the present invention is the webbing take-up device according to any one of the second to fifth aspects, wherein the motor is connected to the rotating body of the tension reducer, and the rotation The body is characterized in that the driving force of the motor is transmitted and rotates in the other direction to rotate the winding shaft in the webbing pull-out direction.

  In the webbing take-up device according to the sixth aspect, since the driving force of the motor is transmitted to the take-up shaft through the rotating body of the tension reducer, the configuration of the device can be simplified.

  The webbing take-up device according to a seventh aspect of the present invention is the webbing take-up device according to any one of the first to sixth aspects, wherein the control means is the motor immediately after the occupant is released from the webbing wearing state. It is characterized by driving.

  In the webbing retractor according to the seventh aspect, the control means drives the motor immediately after the occupant releases the webbing wearing state. As a result, a predetermined torque directed in the webbing pull-out direction is applied to the winding shaft. That is, since the driving force of the motor acts in a direction that cancels the predetermined biasing force of the biasing member, the webbing winding force of the winding shaft is reduced, and the webbing is prevented from being rapidly wound. The motor is stopped at a predetermined opportunity (for example, when a predetermined time has elapsed since driving, or when the webbing is wound up by a predetermined amount, or when the webbing is fully stored).

  As described above, the webbing take-up device according to the present invention can ensure a comfortable webbing pull-out property without hindering the function of the tension reducer.

<First Embodiment>
FIG. 1 is a front cross-sectional view showing a main part configuration of a webbing take-up device 10 according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view showing the configuration of the main part of the webbing take-up device 10. Further, FIG. 3 shows a configuration of a main part of the webbing take-up device 10 in a side sectional view, and FIG. 4 shows a sectional view taken along line 3-3 in FIG. .

  The webbing take-up device 10 includes a take-up shaft 12. The winding shaft 12 is rotatably supported by the frame 14, and the base end portion of the occupant restraining webbing 16 is locked. When the winding shaft 12 is rotated around one axis (hereinafter, this direction is referred to as “winding direction”), the webbing 16 is wound around the outer peripheral portion of the winding shaft 12 from the base end side. On the other hand, when the webbing 16 is pulled from the front end side, the webbing 16 is pulled out while the winding shaft 12 is rotated (hereinafter, the rotation direction of the winding shaft 12 when the webbing 16 is pulled out is referred to as “drawing direction”). Called).

  A motor 18 is disposed below the winding shaft 12. The motor 18 is fixed to the frame 14 by a stay (not shown) in a state where the output shaft 20 is orthogonal to the winding shaft 12.

  A connecting screw 22 is connected to one end of the winding shaft 12 outside the frame 14, and a box-like clutch case 24 is attached to the side of the frame 14. The connecting screw 22 passes through the clutch case 24 and always rotates integrally with the winding shaft 12.

  A worm gear 26 is disposed in the clutch case 24. The worm gear 26 has its own shaft arranged in a state parallel to the output shaft 20 of the motor 18 (a state orthogonal to the winding shaft 12), and its end is supported by the clutch case 24 via bushes 28 and 30. Yes. Further, a steel ball 32 is accommodated in the bearing portion of the clutch case 24 that supports the distal end portion of the worm gear 26 and is in contact with the distal end portion of the worm gear 26, and an adjustment screw 34 is screwed. The adjustment screw 34 presses the steel ball 32 at its tip, thereby pressing the steel ball 32 to the tip of the worm gear 26. Thereby, the axial displacement of the worm gear 26 is regulated (thrust adjustment).

  The base end side of the worm gear 26 protrudes outward from the clutch case 24, and a spur gear 36 is coaxially and integrally attached to the protruding portion. The spur gear 36 meshes with a spur gear 38 that is coaxially and integrally fixed to the output shaft 20 of the motor 18.

  On the other hand, a first clutch 40 is disposed in the clutch case 24. The first clutch 40 is disposed above the worm gear 26 and includes a worm wheel 42 formed in a ring shape. A disk-shaped member 44 is integrally provided inside the worm wheel 42, and the worm wheel 42 is rotatably supported by the clutch case 24 via the disk-shaped member 44. Further, a transmission member (not shown) is supported on the disk-shaped member 44.

  In the first clutch 40, when the worm wheel 42 rotates in the winding direction, the transmission member couples the worm wheel 42 and the winding shaft 12 so as to transmit rotation. On the other hand, in the first clutch 40, when the worm wheel 42 rotates in the pull-out direction or when the worm wheel 42 stops, the mechanical coupling by the transmission member is released. Yes.

  The first clutch 40 configured as described above is configured such that the rotation of the output shaft 20 of the motor 18 is transmitted to the worm wheel 42 via the spur gear 38, the spur gear 36, and the worm gear 26. In this case, when the output shaft 20 of the motor 18 rotates (forward) in the forward direction (direction of arrow C in FIG. 2), the worm wheel 42 is rotated in the pull-out direction (in the direction of arrow A in FIG. 2). When the shaft 20 rotates (reverses) in the reverse direction (arrow D direction in FIG. 2), the worm wheel 42 is rotated in the winding direction (arrow B direction in FIG. 2).

  As the first clutch 40, a clutch that is a constituent member of a webbing take-up device described in “Japanese Patent Application No. 2004-109314” already filed by the present applicant can be applied.

  On the other hand, a box-shaped housing 46 is attached to the opposite side of the frame 14 via the clutch case 24. The housing 46 opens toward the frame 14, and a cover 48 (see FIG. 4) is attached to the opening.

  A first spring case 50 is accommodated in the housing 46. The first spring case 50 is formed in a shallow bottomed cylindrical shape that opens toward the opposite side of the frame 14, and external teeth 52 are formed on the outer peripheral portion. The external teeth 52 are spur gears.

  Further, the bottom wall of the first spring case 50 is coaxially and integrally connected to the connection screw 22 through a circular hole formed in the cover 48, and the first spring case 50 is always connected to the winding shaft 12. And rotate together.

  Further, a circular through hole is formed in the bottom wall of the first spring case 50, and a cylindrical support shaft 54 that is coaxially and integrally projected at the tip of the connecting screw 22 has the through hole. It penetrates and is rotatably fitted in a bearing portion 56 projecting from the bottom wall of the housing 46. Thereby, the winding shaft 12 and the first spring case 50 are rotatably supported by the housing 46 via the connection screw 22.

  Inside the first spring case 50 is housed a first spring 58 as a biasing member. The first main spring 58 has an inner end that is one end in the winding direction locked to the bearing portion 56 of the housing 46, and an outer end that is the other end in the winding direction locked to the first spring case 50. The first spiral spring 58 has a spiral direction set so that the outer end rotates in the pull-out direction (arrow A direction in FIG. 2) with respect to the inner end, and the outer end becomes the inner end. On the other hand, a predetermined urging force for urging the outer end in the take-up direction is generated by being rotated and tightened in the pull-out direction.

  On the other hand, an output branch gear 60 is accommodated inside the housing 46 below the first spring case 50. The output branch gear 60 includes a gear portion 62 that is a spur gear, and a worm wheel portion 64 that is coaxially and integrally provided on one end side in the axial direction of the gear portion 62 and has worm wheel teeth formed on the outer peripheral portion thereof. Have. A circular through hole is formed in the shaft center part of the gear part 62 and the worm wheel part 64, and a cylindrical shaft 66 protruding from the bottom wall of the housing 46 is inserted into the through hole. The output branch gear 60 is supported by the housing 46 so as to be rotatable around the shaft 66.

  Further, the worm wheel portion 64 of the output branch gear 60 has a smaller diameter than the gear portion 62, passes through a circular hole formed in the cover 48, is inserted into the clutch case 24, and meshes with the worm gear 26 described above. is doing. As a result, when the worm gear 26 rotates, the worm wheel 42 of the first clutch 40 and the output branch gear 60 rotate together.

  On the other hand, a second clutch 68 is housed inside the housing 46 below the output branch gear 60.

  Here, in FIGS. 5 and 6, the configuration of the second clutch 68 is shown in an exploded perspective view.

  The second clutch 68 includes a base 70. The base 70 includes a main body 72 formed in a disk shape, a cylindrical support shaft 74 projecting toward the axial direction of the main body 72 at the axial center of the main body 72, and a support shaft A substantially C-shaped side wall portion 76 formed coaxially around 74 is integrally provided. The base 70 is supported by the housing 46 so as to be rotatable around the shaft 78 by inserting a shaft 78 projecting from the bottom wall of the housing 46 into the cylinder of the support shaft portion 74.

  A rotor 80 formed in a shallow bottomed cylindrical shape is coaxially provided on one axial end side of the base 70 (on the right side in FIGS. 5 and 6). The rotor 80 is integrally connected to the base 70 in the circumferential direction with the side wall portion 76 of the base 70 fitted in the cylinder. Spiral external teeth 82 are formed on the outer peripheral portion of the bottom wall of the rotor 80, and the external teeth 82 mesh with the gear portion 62 of the output branch gear 60 described above.

  A clutch gear 86 formed in a cylindrical shape is provided on the radially outer side of the side wall portion 84 of the rotor 80 so as to be coaxial with the rotor 80 and relatively rotatable. A flat tooth 88 is formed on the outer periphery of the clutch gear 86, and the tooth 88 corresponds to a tension reducer 114 described later.

  An annular gap is formed between the inner peripheral surface of the clutch gear 86 and the outer peripheral surface of the side wall 84, and a clutch spring 90, which is a torsion coil spring, is coaxially disposed in the annular gap. Has been.

  The clutch spring 90 has an inner diameter dimension in a natural state set to be substantially the same as an outer diameter dimension of the side wall portion 84 of the rotor 80, and an outer diameter dimension in the natural state is set slightly smaller than the inner diameter dimension of the clutch gear 86. In general, it can rotate relative to the clutch gear 86.

  In addition, a locking portion 92 extends radially inward at one end of the clutch spring 90 in the winding direction (the end on the arrow F direction side in FIGS. 5 and 6). Is locked to the side wall 84 of the rotor 80.

  Furthermore, a moving portion 94 extends radially inward at the other end portion in the winding direction of the clutch spring 90 (the end portion on the arrow E direction side in FIGS. 5 and 6). The moving portion 94 corresponds to a lever 96 disposed in the cylinder of the rotor 80 (inside the side wall portion 84).

  The lever 96 is rotatably supported by the support shaft portion 74 of the base 70 and includes a pair of connection protrusions 98 that protrude toward the main body portion 72 side of the base 70. Each of these connection protrusions 98 passes through a pair of long holes 100 formed in the main body 72 of the base 70.

  The lever 96 is always urged in one direction around the axis of the base 70 (in the direction of arrow E in FIGS. 5 and 6) by a return spring 102 disposed inside the side wall 76 of the base 70. The pair of connecting projections 98 is held in a state of abutting against one end of each pair of elongated holes 100 in the bending direction (the end on the arrow E direction side in FIGS. 5 and 6).

  Further, the moving portion 94 of the clutch spring 90 described above is locked to the lever 96, and the lever 96 resists the elastic force of the return spring 102 and is rotated in the other direction around the axis with respect to the base 70 (rotor 80). When rotating in the direction of arrow F in FIGS. 5 and 6, the moving portion 94 of the clutch spring 90 is moved in one direction of winding of the clutch spring 90 (in the direction of arrow F in FIGS. 5 and 6). The outer diameter dimension of is increased.

  In addition, when the outer diameter of the clutch spring 90 is increased in this way, the clutch spring 90 presses its outer peripheral portion against the inner peripheral surface of the clutch gear 86. In this state, since a predetermined frictional force is generated between the outer peripheral portion of the clutch spring 90 and the inner peripheral surface of the clutch gear 86, the clutch spring 90 and the clutch gear 86 are connected by this frictional force. It has become.

  On the other hand, a pair of weights 104 each having a substantially semicircular plate shape is disposed on the other side in the axial direction of the base 70 (the side opposite to the rotor 80). A circular bearing hole 106 is formed on each circumferential one end side of the pair of weights 104. A cylindrical support shaft 108 projecting from the main body 72 of the base 70 is rotatably fitted in these bearing holes 106. Thus, each weight 104 is supported by the base 70 so as to be rotatable about the support shaft 108 in the radial direction of the base 70.

  Further, these weights 104 are provided with engaging claws 110 that engage with the connecting projections 98 of the lever 96 described above. Thus, the pair of weights 104 are synchronized (interlocked) via the lever 96, and are normally held inside the base 70 in the radial direction by the urging force of the return spring 102 acting on the lever 96. ing.

  Further, a disc-shaped spacer 112 is disposed on the opposite side of the base 70 via the pair of weights 104. The spacer 112 prevents the pair of weights 104 from falling off from the base 70 and prevents the pair of weights 104 from interfering with the bottom wall of the housing 46.

  Here, in the second clutch 68, when the rotor 80 rotates in one direction around the axis (direction of arrow E in FIGS. 5 and 6), the base 70 integrally connected to the rotor 80 serves as the rotor 80. Rotate in one direction around its axis. For this reason, the pair of weights 104 supported by the base 70 follows the base 70 and rotates around the axis of the base 70. At this time, centrifugal force acts on the pair of weights 104, and rotational torque around each support shaft 108 (each bearing hole 106) acts on each weight 104.

  Therefore, when the magnitude of the rotational torque is equal to or greater than a predetermined value, that is, when the rotational speed of the pair of weights 104 is equal to or greater than the predetermined value, the pair of weights 104 is attached to the return spring 102 that acts on the lever 96. It rotates around the support shaft 108 outward in the radial direction of the base 70 against the force. Thereby, the lever 96 in which the connection projection 98 is engaged with each locking claw 110 of each weight 104 is rotated around the axis in the other direction (direction of arrow F in FIGS. 5 and 6) with respect to the base 70. It is.

  In the second clutch 68 having the above-described configuration, the rotational force of the output shaft 20 of the motor 18 is transmitted to the rotor 80 via the spur gear 38, the spur gear 36, the worm gear 26, and the output branch gear 60. ing. In this case, when the output shaft 20 of the motor 18 rotates in the positive direction (the direction of arrow C in FIG. 2), the rotor 80 is rotated together with the base 70 in the other direction (the direction of arrow E in FIG. 2). When the output shaft 20 rotates in the reverse direction (the direction of arrow D in FIG. 2), the rotor 80 is rotated together with the base 70 in one direction (the direction of the arrow F in FIG. 2) around the axis.

  On the other hand, a tension reducer 114 is provided inside the housing 46.

  Here, in FIG. 7 and FIG. 8, the structure of the tension reducer 114 is shown in an exploded perspective view.

  The tension reducer 114 includes a second spring case 116 as a rotating body. The second spring case 116 is formed in a shallow bottomed cylindrical shape opened to the frame 14 side. A cylindrical bearing 118 is coaxially and integrally formed on the bottom wall of the second spring case 116. A shaft 120 protruding from the bottom wall of the housing 46 is rotatably inserted into the bearing portion 118, whereby the second spring case 116 is supported by the housing 46 so as to be rotatable around the shaft 120. Yes.

  Further, spur external teeth 122 are formed on the outer peripheral portion of the second spring case 116. The external teeth 122 mesh with the external teeth 52 of the first spring case 50 described above and the external teeth 88 of the clutch gear 86 of the second clutch 68, and the clutch gear 86 is unidirectional around its axis (see FIG. 2), the second spring case 116 rotates in one direction around its axis (in the direction of arrow G in FIG. 2), and the first spring case 50 in the pull-out direction (in the direction of arrow A in FIG. 2). It is designed to rotate. On the other hand, when the clutch gear 86 rotates around the axis in the other direction (arrow F direction in FIG. 2), the second spring case 116 rotates around the axis in the other direction (arrow H direction in FIG. 2). 50 rotates in the winding direction (arrow B direction in FIG. 2).

  The worm gear 26, the worm wheel portion 64 of the output branch gear 60, the gear portion 62 of the output branch gear 60, the external teeth 82 of the rotor 80, the external teeth 88 of the clutch gear 86, the external teeth 112 of the second spring case 116, and The total reduction ratio by the external teeth 52 of the first spring case 50 is set sufficiently lower than the reduction ratio of the worm gear 26 and the worm wheel 42.

  Inside the second spring case 116, an adapter 124 constituting a restricting means is provided. The adapter 124 is formed in a cylindrical shape, and the shaft 120 is inserted into the cylinder. Accordingly, the adapter 124 is supported by the housing 46 so as to be rotatable around the shaft 120, and is rotatable relative to the second spring case 116.

  An outer ratchet tooth 126 is formed on the outer peripheral portion of the adapter 124 on one axial end side (right side in FIGS. 7 and 8), and on the one axial end side of the ratchet tooth 126, a cylindrical shape is formed. A boss portion 128 is provided so as to protrude coaxially and integrally. These ratchet teeth 126 and the boss portion 128 correspond to a cushion spring 144 described later.

  In addition, an annular gap is formed between the outer peripheral surface of the adapter 124 and the inner peripheral surface of the second spring case 116, and a second spring 130 as a pulling direction biasing member is formed in the annular gap. Has been placed. The second spring 130 has an outer end that is one end in the winding direction locked to the second spring case 116, and an inner end that is the other end in the winding direction locked to the adapter 124. The second mainspring 130 is tightened by rotating the outer end (second spring case 116) with respect to the inner end (adapter 124) around the axis in the other direction (the direction indicated by the arrow H in FIGS. 7 and 8). The swirl direction is set in such a manner that the outer end rotates in the other direction around the axis with respect to the inner end and is tightened so that the outer end is rotated in one direction around the axis (the direction of arrow G in FIGS. 7 and 8). It has a structure that generates a biasing force that biases the

  Further, a ratchet board 132 constituting a restricting means is disposed on one end side in the axial direction of the second spring case 116 (right side in FIGS. 7 and 8). The ratchet disc 132 includes a disc portion 134 and a ratchet portion 136 formed coaxially on one end side in the axial direction of the disc portion 134. A cylindrical boss 138 is formed at the axial center of the disk portion 134, and the adapter 124 is fitted into the cylinder of the boss 138 so as to be relatively rotatable. It is supported on the shaft 120 via 124. Furthermore, external ratchet teeth 140 are formed on the outer peripheral portion of the ratchet portion 136. The ratchet teeth 140 correspond to a pawl 158 described later.

  A spring accommodating portion 142 is formed inside the ratchet portion 136, and a cushion spring 144 that constitutes a restricting means is accommodated in the spring accommodating portion 142. The cushion spring 144 has an intermediate portion formed in a coil shape, and a clamping portion 146 formed in a V shape on one end side of the coiled intermediate portion is directed to the boss 138 side (adapter 124 side). It is extended toward. The clamping part 146 clamps the boss part 128 of the adapter 124 by its own elastic force.

  Further, an L-shaped connecting portion 148 extends toward the boss 138 side (adapter 124 side) on the other end side from the coiled intermediate portion of the cushion spring 144. The connecting portion 148 is disposed so as to face the ratchet teeth 126 of the adapter 124.

  Here, when the adapter 124 rotates relative to the ratchet board 132 in one direction around the axis (the direction indicated by the arrow G in FIGS. 7 and 8), the connecting portion 148 of the cushion spring 144 causes the ratchet teeth of the adapter 124 to move. By being pressed by the inclined surface of 126 and moving radially outward of the adapter 124, the connecting portion 148 of the cushion spring 144 is maintained in a state of being separated from the ratchet teeth 126 of the adapter 124 as shown in FIG. It has become so.

  On the other hand, when the adapter 124 rotates around the axis relative to the ratchet board 132 in the other direction (the direction indicated by the arrow H in FIGS. 7 and 8), the cushion spring 144 moves between the holding portion 146 and the adapter 124. 9B, the coupling portion 148 of the cushion spring 144 is engaged with the ratchet teeth 126 of the adapter 124 as shown in FIG. 9B. It has become. In this state, the adapter 124 and the ratchet board 132 are mechanically coupled via the cushion spring 144 so that the relative rotation of the adapter 124 in the other direction around the axis with respect to the ratchet board 132 is restricted.

  On the other hand, the tension reducer 114 includes a solenoid 150 that constitutes a restricting unit. The solenoid 150 is disposed below the ratchet board 132 and includes a solenoid body 152 fixed to the bottom wall of the housing 46 and a plunger 154 inserted into a hole formed in one side wall of the solenoid body 152. ing. The solenoid 150 is a so-called “pull type”, and when the solenoid body 152 is not energized, the plunger 154 is pulled out of the solenoid body 152 by the urging force of the return spring 156 and energized to the solenoid body 152. In the configuration, the plunger 154 is drawn into the solenoid body 152 side.

  Further, a pawl 158 constituting a restricting means is disposed between the solenoid 150 and the ratchet board 132, and the pawl 158 includes a main body 160 formed in a substantially L-time shape. A circular hole 162 is formed in the bent portion of the main body portion 160, and the main body portion 160 rotates around the shaft 164 by inserting the shaft 164 protruding from the bottom wall of the housing 46 into the circular hole. It is supported by the housing 46 as possible.

  A slit-like connecting groove 166 is formed at one end of the main body 160, and the distal end portion of the plunger 154 is fitted into and connected to the connecting groove 166. Further, a locking claw 168 that protrudes toward the ratchet teeth 140 of the ratchet board 132 is formed at the other end of the main body 166.

  In the state where the plunger 154 of the solenoid 150 is pulled toward the solenoid body 152, the pawl 158 engages the ratchet teeth 140 with the end of the locking claw 168 approaching the ratchet board 132. It is like that. In this state, the ratchet board 132 can rotate in one direction around its axis (in the direction of arrow G in FIGS. 7 and 8), but in the other direction around the axis (in the direction of arrow H in FIGS. 7 and 8). The rotation is restricted by the locking claw 168. On the other hand, in the state where the plunger 154 of the solenoid 150 is pulled out from the solenoid body 152, the pawl 158 is separated from the ratchet board 132, and the engagement state between the latching claw 168 and the ratchet teeth 140 is It is to be released.

  The tension reducer 114 having the above configuration is turned on when the solenoid main body 152 of the solenoid 150 is energized and turned off when the energization of the solenoid main body 152 is interrupted.

  On the other hand, the webbing take-up device 10 includes an ECU 170 and a driver 172 that constitute control means. ECU 170 stores a drive control program according to the first embodiment of the present invention. The driver 172 is electrically connected to a motor 18 and a battery 174 mounted on the vehicle. A current from the battery 174 flows to the motor 18 via the driver 172, so that the motor 18 has a driving force. Thus, the output shaft 20 is rotated. The driver 172 is connected to the ECU 170, and the ECU 170 controls the presence / absence of power supply to the motor 18 via the driver 172, the direction and magnitude of the supply current. In addition, the solenoid body 152 of the solenoid 150 is electrically connected to the driver 172, and the current from the battery 174 is supplied to the solenoid body 152 via the driver 172, so that the plunger 154 is on the solenoid body 152 side. To be drawn into.

  The ECU 170 is connected to a take-up shaft rotation detection sensor 176 (magnetic sensor in the first embodiment) that constitutes a control means. The take-up shaft rotation detection sensor 176 corresponds to a magnet 178 provided on the outer periphery of one end of the take-up shaft 12, and the magnet 178 is near the take-up shaft rotation detection sensor 176 due to the rotation of the take-up shaft 12. Is repeatedly detected, the magnetism generated by the magnet 178 is detected, and a predetermined electrical signal (hereinafter referred to as “detection signal”) is output to the ECU 170.

  In this case, the ECU 170 determines the state of the winding shaft 12 based on the detection signal output from the winding shaft rotation detection sensor 176 (whether the winding shaft 12 is rotating, in particular, the pulling direction of the winding shaft 12). And the like, and it is determined whether the webbing 16 has been pulled out by the occupant based on the detection result.

  Further, the ECU 170 is connected to a buckle switch 180 as a control means for detecting whether or not a tongue plate provided on the webbing 16 is coupled to a buckle device (both not shown). When the tongue plate is connected to the buckle device, the buckle switch 180 outputs an H level signal indicating the on state of the switch to the ECU 170, and when the tongue plate is released from the buckle device, the switch is in the off state. Is output to the ECU 170.

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

  When an occupant riding in the vehicle pulls out the webbing 16 stored in the webbing take-up device 10, the take-up shaft 12 and the first spring case 50 rotate in the pull-out direction (arrow A direction in FIG. 2), and the second The spring case 116 rotates in one direction around its axis (in the direction of arrow G in FIG. 2), and the clutch gear 86 rotates in one direction around its axis (in the direction of arrow E in FIG. 2).

  As the first spring case 50 rotates in the pull-out direction, the outer end of the first mainspring spring 58 rotates in the pull-out direction, but the inner end of the first mainspring spring 58 is fixed to the bearing portion 56 of the housing 46. The first spring 58 has a predetermined urging force that urges the outer end, that is, the first spring case 50 in the winding direction (the direction of arrow B in FIG. 2) (hereinafter, a predetermined urging force generated on the first spring 58). The biasing force is called “first biasing force”).

  Further, as described above, the take-up shaft rotation detection sensor 176 inputs a detection signal to the ECU 170 as the take-up shaft 12 rotates in the pull-out direction (step 182). Thus, in step 184, ECU 170 and driver 172 cause output shaft 20 of motor 18 to rotate forward (rotate in the direction of arrow C in FIG. 2).

  The normal rotation of the output shaft 20 of the motor 18 is transmitted to the worm gear 26 via the spur gear 38 and the spur gear 36, and the worm gear 26 rotates. The rotation of the worm gear 26 is transmitted to the worm wheel 42 of the first clutch 40, and the worm wheel 42 is rotated in the pull-out direction (the direction of arrow A in FIG. 2) at a rotation speed equal to or higher than a predetermined value. In this case, the worm wheel 42 and the take-up shaft 12 are maintained in a state in which the mechanical coupling by a transmission member (not shown) is released, and therefore the worm wheel 42 and the take-up shaft 12 are idled relatively.

  The rotation of the worm gear 26 is transmitted to the rotor 80 of the second clutch 68 via the output branch gear 60, and the rotor 80 rotates in one direction around the axis (in the direction of arrow E in FIG. 2) at a rotational speed equal to or higher than a predetermined value. It is rotated. For this reason, the base 70 integrally connected to the rotor 80 is rotated around the axis in one direction (the direction of arrow E in FIG. 2) at a rotational speed equal to or higher than a predetermined value.

  The rotation of the base 70 is transmitted to the pair of weights 104 via the support shaft 108, and the pair of weights 104 follows the base 70 and rotates around the axis of the base 70 at a rotation speed equal to or higher than a predetermined value. As a result, centrifugal force acts on the pair of weights 104, and the pair of weights 104 rotate around the support shaft 108 radially outward of the base 70 against the urging force of the return spring 102 acting on the lever 96. Move.

  For this reason, the lever 96 in which the connection protrusion 98 is engaged with the locking claw 110 of the weight 104 is rotated around the axis in the other direction (the direction of arrow F in FIG. 2) with respect to the base 70. When the lever 96 is rotated in the other direction around the axis with respect to the base 70, the moving portion 94 of the clutch spring 90 is moved by the lever 96 in one direction of winding of the clutch spring 90 (the direction of arrow F in FIG. 2). . As a result, the outer diameter of the clutch spring 90 is enlarged, and the outer peripheral portion of the clutch spring 90 is pressed against the inner peripheral surface of the clutch gear 86. As a result, the rotation of the clutch spring 90 is transmitted to the clutch gear 86, and a predetermined torque directed in one direction (in the direction of arrow E in FIG. 2) around the axis is applied to the clutch gear 86. Since the external teeth 88 of the second spring case 116 mesh with the external teeth 88 of the clutch gear 86, the second spring case 116 is directed in one direction around the axis (in the direction of arrow G in FIG. 2). The predetermined torque is applied.

  Furthermore, since the external teeth 122 of the first spring case 50 are engaged with the external teeth 122 of the second spring case 116, when torque directed in one direction around the axis is applied to the second spring case 116, A predetermined torque is applied to the first spring case 50 (winding shaft 12) in the pulling direction (the direction of arrow A in FIG. 2). In other words, the winding shaft 12 is applied with a predetermined torque that resists the first urging force (the urging force directed in the winding direction) of the first main spring 58 described above. This assists the occupant withdrawing the webbing 16, so that the occupant can pull out the webbing 16 with a light force.

  Since the outer end of the second spring spring 130 is connected to the second spring case 116, the outer end of the second spring spring 130 is integrated with the second spring case 116 in one direction around its axis (see FIG. 2). Rotate in the direction of arrow G). Therefore, the inner end of the second mainspring 130 also tries to rotate following the outer end, and the adapter 124 connected to the inner end of the second mainspring 130 is rotated in one direction around its axis and supported by the adapter 124. The ratchet board 132 rotates in one direction around its axis.

  When the processing in step 184 is completed, the process proceeds to next step 186.

  In step 186, ECU 170 determines whether or not buckle switch 180 is turned on, that is, whether or not the occupant who has pulled out webbing 16 has attached the webbing 16 by connecting the tongue plate to the buckle device. Only when the determination at step 186 is affirmative, the routine proceeds to the next step 188.

  In step 188, the ECU 170 and the driver 172 stop the output shaft 20 of the motor 18. Thereby, the application of the predetermined torque to the winding shaft 12 by the driving force of the motor 18 is released. At this time, since the rotation of the rotor 80 is stopped, the rotation of the base 70 integrally connected to the rotor 80 is stopped. When the rotation of the base 70 is stopped, the pair of weights 104 are rotated inward in the radial direction of the base 70 by the elastic force of the clutch spring 90 acting on the lever 96 and the urging force of the return spring 102. For this reason, the clutch spring 90 returns to the natural state again, the outer peripheral portion thereof is separated from the inner peripheral surface of the clutch gear 86, and the connection between the clutch spring 90 and the clutch gear 86 is immediately released (second clutch 68). Will be unlinked). When the processing at step 188 is completed, the routine proceeds to the next step 190.

  In step 190, the ECU 170 and the driver 172 start energizing the solenoid body 152 of the tension reducer 114 to turn on the tension reducer 114. When energization of the solenoid main body 152 is started, the plunger 154 is drawn to the solenoid main body 152 side, the pawl 158 connected to the tip of the plunger 154 rotates around the shaft 164, and the pawl 168 of the pawl 158 is engaged. Engages with the ratchet teeth 140 of the ratchet wheel 132. When the processing in step 190 is completed, the process proceeds to next step 192.

  In step 192, the ECU 170 determines whether or not the mounted webbing 16 has been pulled out, for example, based on a detection signal from the take-up shaft rotation detection sensor 176. Judgment. Only when the determination in step 192 is affirmed, the process proceeds to the next step 194.

  In step 194, the ECU 170 and the driver 172 cause the output shaft 20 of the motor 18 to rotate forward. For this reason, as in step 184 described above, the second clutch 68 is engaged, and the predetermined torque directed to the first spring case 50 (winding shaft 12) in the drawing direction (the direction of arrow A in FIG. 2). Is granted. As a result, the webbing 16 is assisted to be pulled out, so that it is possible to prevent the occupant trying to take the forward-bent posture from giving a feeling of pressure.

  At this time, as the first spring case 50 rotates in the pull-out direction, the second spring case 116 rotates in one direction around the axis (in the direction of arrow G in FIG. 2), and the outer end of the second spring spring 130 moves to the first end. 2 Rotates in one direction around its axis integrally with the spring case 116. Therefore, the inner end of the second spring spring 130 also tries to rotate following the outer end, and the adapter 124 to which the inner end of the second spring spring 130 is connected is unidirectionally relative to the ratchet disc 132 (see FIG. 2 in the direction of arrow G). In this case, since the mechanical connection between the adapter 124 and the ratchet disc 132 by the cushion spring 144 is released, the adapter 124 is allowed to rotate in one direction around the axis, and the inner end of the second spring 130 is connected to the outer end. Follow and rotate around one axis.

  When the processing in step 194 is completed, the process proceeds to the next step 196.

  In step 196, the ECU 170 detects from the winding shaft rotation detection sensor 176 whether or not the webbing 16 has been pulled out in the mounted state as described above, for example, when the occupant returns from the forward bent posture to the normal posture. Judgment based on. Only when this determination is affirmed, the process proceeds to the next step 198.

  In step 198, the ECU 170 and the driver 172 stop the output shaft 20 of the motor 18. For this reason, as in step 188 described above, the connected state of the second clutch 68 is released, and the application of the predetermined torque to the winding shaft 12 by the driving force of the motor 18 is released. For this reason, the winding shaft 12 is rotated in the winding direction (in the direction of arrow B in FIG. 2) by the above-described first biasing force of the first spring spring 58, whereby the slack of the webbing 16 is removed.

  At this time, the first spring case 50 rotates in the winding direction integrally with the winding shaft 12, so that the second spring case 116 rotates in the other direction (the direction of arrow H in FIG. 2) around the axis. . For this reason, the outer end of the second spring spring 130 connected to the second spring case 116 is rotated in the other direction around the axis of the second spring case 116, and the inner end of the second spring spring 130 follows the outer end to follow the second end. An attempt is made to rotate in the other direction (in the direction of arrow H in FIG. 2) around the axis of the spring case 116. For this reason, the adapter 124 to which the inner end of the second spring spring 130 is connected is rotated relative to the ratchet disc 132 in the other direction around the axis (in the direction of arrow H in FIG. 2). When the adapter 124 is rotated in the other direction around the axis relative to the ratchet board 132, the coupling portion 148 of the cushion spring 144 is engaged with the ratchet teeth 126 of the adapter 124, and the adapter 124 is around the axis of the ratchet board 132. Relative rotation in the other direction is restricted. Therefore, the inner end of the second spring 130 connected to the adapter 124 cannot rotate around the axis in the other direction. In this state, when the winding shaft 12 further rotates in the winding direction, the outer end of the second spring spring 130 is rotated in the other direction around the axis together with the second spring case 116, and the second spring spring 130 has the outer end, that is, the second end. A biasing force that biases the spring case 116 in one direction around the axis (in the direction of arrow G in FIG. 2) is generated (hereinafter, the biasing force generated in the second spring 130 is referred to as “second biasing force”).

  The second biasing force acts on the first spring case 50 (winding shaft 12) in a direction in which the first spring case 50 (winding shaft 12) is rotated in the pull-out direction. Therefore, the first biasing force (winding direction) of the first spring spring 58 is applied. ) Is offset by the second urging force (the first urging force is reduced by the second urging force and applied to the winding shaft 12).

  As described above, the second urging force of the second mainspring spring 130 against the first urging force of the first mainspring spring 58 is applied to the winding shaft 12 in a state where the occupant wears the webbing 16, thereby restraining the webbing 16. It is possible to weaken the force and prevent or effectively reduce the feeling of pressure on the occupant. In this state, the webbing winding force of the winding shaft 12 resulting from the first biasing force of the first spring spring 58 is reduced by the amount of the second biasing force of the second spring spring 130 as described above. In the webbing 16, the second and subsequent drawers become lighter.

  When the processing at step 198 is completed, the routine proceeds to the next step 200.

  In step 200, ECU 170 determines whether or not buckle switch 180 has been turned off, that is, whether or not the occupant has released the connection state of the webbing 16 by releasing the connection between the tongue plate and the buckle device. Only when this determination is affirmed, the routine proceeds to the next step 202.

  In step 202, the ECU 170 and the driver 172 cut off the energization of the tension reducer 114 to the solenoid body 152 to turn off the tension reducer 114. Therefore, the plunger 154 of the solenoid 150 is pulled out of the solenoid body 152 by the urging force of the return spring 156, the pawl 158 connected to the plunger 154 rotates around the shaft 164, and the pawl 168 of the pawl 158 is ratchet. Separate from the ratchet teeth 140 of the plate 132. As a result, the ratchet board 132 can be rotated in the other direction around the axis of the ratchet board 132 (in the direction indicated by the arrow H in FIG. 2). Is rotated in the other direction around the axis. As a result, the second biasing force of the second spring spring 130 disappears. Accordingly, the take-up shaft 12 is rotated in the take-up direction by the first urging force of the first mainspring spring 58, whereby the webbing 16 is taken up by the take-up shaft 12. When the processing in step 202 is completed, the process proceeds to next step 204.

  In step 204, the ECU 170 and the driver 172 cause the output shaft 20 of the motor 18 to rotate forward. Therefore, the driving force of the motor 18 is transmitted to the first spring case 50 via the clutch gear 86 of the second clutch 68 and the second spring case 116 of the tension reducer 114, and the first spring case 50 (winding shaft 12). Is applied with a predetermined torque directed in the pull-out direction. Since this torque acts in a direction that cancels the first urging force of the first mainspring spring 58, the winding force of the winding shaft 12 is reduced, and the webbing 16 is prevented from being wound rapidly. Thereby, for example, the collision between the tongue plate and the door trim due to the rapid winding of the webbing 16 and the occurrence of so-called end lock can be avoided. The motor 18 is stopped at a predetermined opportunity (for example, when a predetermined time has elapsed since the normal rotation, or when the webbing 16 is wound up by a predetermined amount, or when the webbing 16 is fully stored).

  When the process in step 204 is finished, the drive control program according to the first embodiment is finished.

  In the webbing take-up device 10, for example, an obstacle exists in front of the vehicle and the distance between the vehicle and the obstacle is within a predetermined range when the occupant wears the webbing 16 and runs the vehicle. When the front monitoring device (not shown) detects that the output has reached, the ECU 170 and the driver 172 reverse the output shaft 20 of the motor 18. The reverse rotation of the output shaft 20 of the motor 18 is transmitted to the worm wheel 42 of the first clutch 40 via the spur gear 38, the spur gear 36 and the worm gear 26, and the worm wheel 42 is wound at a rotational speed equal to or higher than a predetermined value. Rotated in the direction. Thereby, the worm wheel 42 and the winding shaft 12 are coupled by a transmission member (not shown), and the winding shaft 12 is rotated integrally with the worm wheel 42 in the winding direction. The webbing 16 is forcibly taken up by the take-up shaft 12 by the rotation of the take-up shaft 12 in the take-up direction, so that the slack of the webbing 16, so-called “slack” is eliminated. The restraining force is improved (so-called “pretensioner mechanism”).

  As described above, in the webbing retractor 10 according to the first embodiment of the present invention, a comfortable webbing pull-out property can be ensured without hindering the function of the tension reducer 114.

  In the webbing take-up device 10 according to the first embodiment of the present invention, the driving force of the motor 18 is transmitted to the take-up shaft 12 via the second spring case 116 of the tension reducer 114. The configuration of the device is simple.

  Moreover, in the webbing retractor 10 according to the first embodiment of the present invention, the driving force of the motor 18 is transmitted to the second spring case 116 and the first spring case 50 via the second clutch 68. The torque transmitted by the second clutch 68 is proportional to the pressure between the clutch spring 90 and the clutch gear 86. Since this crimping force is proportional to the centrifugal force acting on the pair of weights 104, that is, the rotational speed of the motor 18, the magnitude of the current supplied to the motor 18 when the motor 18 is rotating forward (at the time of pulling assist) is determined by the ECU 170 and the driver 172. It is possible to obtain an arbitrary transmission torque (drawing assisting force) by changing the value of.

Therefore, in the webbing take-up device 10 according to the first embodiment of the present invention,
(1) When the occupant pulls out the retracted webbing 16 (step 184)
(2) When the worn webbing 16 is pulled out (step 194)
(3) When the occupant releases the connection between the buckle and the tongue plate (step 204)
(4) In addition to the above, it is possible to give an optimum transmission torque in each case when it is necessary to actively assist the pulling out of the webbing 16. Note that the magnitude of the transmission torque in the above (1) to (4) is preferably set to the relationship of (4)>(2)>(1)> (3).

  That is, in the case of the above (4), since it is necessary to actively assist the pulling out of the webbing 16, the rotational speed of the motor 18 (the magnitude of the current supplied to the motor 18) is positively increased. It is preferable to increase the transmission torque of the two-clutch 68 to the maximum.

  In the case of (2) above, since the winding biasing force of the first main spring 58 has increased, the rotational speed of the motor 18 is increased to some extent, and the transmission torque of the second clutch 68 is increased by the winding of the first main spring 58. It is preferable to increase it to an extent that can counter the biasing force.

  In the case of (1), the winding biasing force of the first mainspring spring 58 is reduced, so that the rotational speed of the motor 18 is set lower than in the case of (2) and the transmission torque of the second clutch 68 is set. Is preferably reduced.

  In the case of (3) above, it is preferable to set the rotation speed of the motor 18 to such an extent that the winding force of the webbing 16 by the first spring spring 58 is somewhat reduced to prevent rapid winding of the webbing 16.

  Further, when the webbing 16 is wound and withdrawn, the rotation speed (the magnitude of the transmission torque) of the motor 18 is changed corresponding to the change in the drawing amount of the webbing 16 (change in the urging force of the first spring 58). It is also possible to make it.

  About the above point, it is the same also about the following embodiments.

In the drive control program according to the first embodiment, a process for continuing the normal rotation of the motor 18 for a predetermined time may be provided between step 186 and step 188. In other words, if the webbing is positively generated when the occupant wears the webbing, rotation of the winding shaft 12 in the webbing winding direction can be sufficiently ensured. Can function. Therefore, in this case, the processing from step 192 to step 198 can be omitted.
<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. 11 is an exploded perspective view showing a main part configuration of a webbing take-up device 220 according to the second embodiment of the present invention. Further, FIG. 12 shows a configuration of the main part of the webbing take-up device 220 in a side sectional view, and FIG. 13 shows a sectional view taken along line 5-5 in FIG. .

  The webbing take-up device 220 has basically the same configuration as the webbing take-up device 10 according to the first embodiment, but differs in the following points.

  The webbing take-up device 220 includes a housing 222. The housing 222 has basically the same configuration as the housing 46 according to the first embodiment, and is attached to the opposite side of the frame 14 via the clutch case 24. However, the housing 222 is formed to be smaller in thickness and width than the housing 222 according to the first embodiment. A cover 224 is attached to the opening of the housing 222.

  Further, the webbing take-up device 220 includes a tension reducer 226 instead of the tension reducer 114 according to the first embodiment.

  Here, in FIGS. 14 and 15, the configuration of the tension reducer 226 is shown in an exploded perspective view.

  The tension reducer 226 includes an adapter 228 as a rotating body. The adapter 228 is formed in a shallow bottomed cylindrical shape opened toward the frame 14 side. A circular hole 230 is formed in the axial center of the bottom wall of the adapter 228, and a cylindrical shaft 232 projecting from the bottom wall of the housing 222 is rotatably inserted into the circular hole 230. Yes. Thus, the adapter 228 is supported by the housing 222 so as to be rotatable around the shaft 232.

  A cylindrical boss portion 234 is coaxially and integrally formed on one side in the axial direction of the bottom wall of the adapter 228 (the right side in FIGS. 14 and 15). The boss portion 234 corresponds to a clutch spring 252 described later.

  Further, spur external teeth 236 are formed on the outer peripheral portion of the adapter 228. The external teeth 236 mesh with the external teeth 52 of the first spring case 50 and the external teeth 88 of the clutch gear 86 of the second clutch 68, and the clutch gear 86 is in one direction around its axis (see FIG. 11). When rotating in the direction of arrow E), the adapter 228 rotates in one direction around its axis (in the direction of arrow G in FIG. 11), and the first spring case 50 rotates in the pull-out direction (in the direction of arrow A in FIG. 11). ing. On the other hand, when the clutch gear 86 rotates around the axis in the other direction (arrow F direction in FIG. 11), the adapter 228 rotates around the axis in the other direction (arrow H direction in FIG. 11), and the first spring case 50 is wound. It rotates in the taking direction (arrow B direction in FIG. 11).

  The worm gear 26, the worm wheel portion 64 of the output branch gear 60, the gear portion 62 of the output branch gear 60, the external teeth 82 of the rotor 80, the external teeth 88 of the clutch gear 86, the external teeth 236 of the adapter 228, and the first spring. The total reduction ratio by the external teeth 52 of the case 50 is set sufficiently lower than the reduction ratios of the worm gear 26 and the worm wheel 42.

  On the other hand, on one side in the axial direction of the adapter 228 (on the right side in FIGS. 14 and 15), a ratchet board 238 constituting a restricting means is disposed. The ratchet board 238 is formed in a shallow bottomed cylindrical shape that opens toward the opposite side of the frame 14. A cylindrical bearing portion 240 is coaxially and integrally formed on one end side in the axial direction of the bottom wall of the ratchet board 238. The shaft 232 described above is rotatably inserted into the cylinder of the bearing portion 240. Has been. Thus, the ratchet board 238 is supported by the housing 222 so as to be rotatable around the shaft 232, and is coaxial with the adapter 228 and is rotatable relative to the adapter 228.

  Ratchet teeth 242 having external teeth similar to the ratchet teeth 140 according to the first embodiment are formed on the outer peripheral portion of the side wall of the ratchet board 238. Similar to the ratchet teeth 140 of the ratchet board 132 according to the first embodiment, the ratchet teeth 242 have a pawl for the pawl 158 when the plunger 154 of the solenoid 150 is retracted to the solenoid body 152 side. 168 is engaged.

  In addition, inner ratchet teeth 244 are formed on the inner peripheral portion of the side wall of the ratchet board 238. The direction of the ratchet teeth 244 is formed opposite to the direction of the ratchet teeth 242.

  On the other hand, a holder 246 constituting a restricting means is provided inside the ratchet board 238. The holder 246 is formed in a ring shape as a whole, and is arranged coaxially with respect to the adapter 228 and the ratchet board 238.

  The holder 246 includes a main body portion 248 formed in a cylindrical shape and a ring-shaped flange portion 250 formed so as to protrude radially outward from the outer periphery of one end side (left side in FIGS. 14 and 15) of the main body portion 248 in the axial direction. And have. The outer periphery of the flange portion 250 is rotatably fitted inside the side wall of the ratchet board 238, whereby the holder 246 is supported so as to be rotatable relative to the ratchet board 238. Further, the main body 248 is formed in a C-shape on the side opposite to the adapter 228 via the flange portion 250, and the C-shaped portion is accommodated inside the ratchet board 238. .

  Further, an annular gap is formed between the inner peripheral surface of the main body portion 248 and the outer peripheral surface of the boss portion 234, and a clutch spring 252 as a drag application member is disposed in the annular gap. . The clutch spring 252 is a torsion coil spring, and the boss portion 234 of the adapter 228 is fitted inside the clutch spring 252. Thereby, the clutch spring 252 is supported by the adapter 228. The inner diameter dimension of the clutch spring 252 in the natural state is slightly smaller than the outer diameter dimension of the boss portion 234, and the clutch spring 252 basically rotates integrally with the adapter 228.

  In addition, a locking portion 254 that protrudes radially outward is formed at one end of the clutch spring 252 in the winding direction (the end in the arrow H direction in FIGS. 14 and 15). The locking portion 254 is locked in a locking groove 256 formed in the main body portion 250 of the holder 246.

  Here, in the clutch spring 252, the adapter 228 moves in the other direction around the axis with respect to the clutch spring 252 (the direction indicated by the arrow H in FIGS. 14 and 15) with the rotation of the locking portion 254 (holder 246) restricted. When the rotation is relatively performed, the clutch spring 252 is wound and contracted by sliding contact between the inner peripheral portion of the clutch spring 252 and the outer peripheral surface of the boss portion 234. In this state, a predetermined drag force (friction force) is applied to the rotation of the adapter 228 to the other around the axis with respect to the clutch spring 252.

  On the other hand, an annular gap is formed between the side wall of the ratchet board 238 and the main body 248 of the holder 246, and a lock spring 258 that constitutes a restricting means is disposed in this gap. The lock spring 258 is formed by bending a belt-shaped spring material into a C shape, and its outer periphery is in close contact with the tip of the ratchet teeth 244 of the ratchet board 238.

  An engaging portion 260 that is bent in a substantially L shape is provided at one end portion in the bending direction of the lock spring 258 (the end portion in the direction of arrow G in FIGS. 14 and 15). The distal end side of the engaging portion 260 is disposed between a pressing portion 261 formed at one end in the circumferential direction of the main body portion 248 of the holder 246 and a pressing protrusion 262 protruding from the flange portion 250 of the holder 246. Usually, it is arranged away from the ratchet teeth 244.

  Here, when the holder 246 rotates relative to the ratchet board 238 in one direction around the axis (in the direction indicated by the arrow G in FIGS. 14 and 15), the distal end side of the engaging portion 260 is pressed against the lock spring 258. By being pressed in one direction around the axis by 262, it follows the holder 246 and tries to rotate in one direction around the axis. In this case, as shown in FIG. 16A, the locking portion 260 is maintained in a state of being separated from the ratchet teeth 244, and relative rotation of the lock spring 258 and the holder 246 with respect to the ratchet disc 238 in one direction around the axis is allowed. It is the composition which becomes.

  On the other hand, when the holder 246 rotates relative to the ratchet board 238 in the other direction around the axis (the direction indicated by the arrow H in FIGS. 14 and 15), the lock spring 258 engages with the pressing portion 261 of the holder 246. By pressing the distal end side of the joint portion 260 around the axis in the other direction, the distal end of the engaging portion 260 comes close to and engages with the ratchet teeth 244 of the ratchet disc 238 as shown in FIG. ing. In this state, the holder 246 and the ratchet board 238 are integrally connected via the lock spring 258 (that is, the holder 246, the clutch spring 258, and the ratchet board 238 constitute a one-way clutch. ing).

  In the tension reducer 226 configured as described above, as in the tension reducer 226 according to the first embodiment, the solenoid body 152 of the solenoid 150 is turned on by being energized, and the energization to the solenoid body 152 is interrupted. This is a configuration that is turned off.

  The webbing take-up device 220 according to the second embodiment has the same configuration as that of the webbing take-up device 10 according to the first embodiment except for the other components. However, the ECU 170 of the webbing retractor 220 stores a drive control program according to the second embodiment of the present invention. Further, in the second clutch 68 of the webbing take-up device 220, the length dimension along the axial direction of the clutch gear 80 is formed shorter than that in the first embodiment.

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

  When an occupant riding in the vehicle pulls out the webbing 16 stored in the webbing take-up device 10, the take-up shaft 12 and the first spring case 50 rotate in the pull-out direction (the direction of arrow A in FIG. 11) and the adapter 228. Rotates in one direction around the axis (in the direction of arrow G in FIG. 11), and the clutch gear 86 rotates in one direction around the axis (in the direction of arrow E in FIG. 2).

  As the first spring case 50 rotates in the pull-out direction, the outer end of the first mainspring spring 58 rotates in the pull-out direction, but the inner end of the first mainspring spring 58 is fixed to the bearing portion 56 of the housing 46. The first spring 58 has a predetermined urging force that urges the outer end, that is, the first spring case 50 in the winding direction (the direction of arrow B in FIG. 11) (hereinafter, a predetermined urging force generated on the first spring 58). The biasing force is called “first biasing force”).

  Further, as described above, the winding shaft 12 rotates in the pull-out direction, so that the winding shaft rotation detection sensor 176 inputs a detection signal to the ECU 170 (step 264). Thus, in step 266, the ECU 170 and the driver 172 cause the output shaft 20 of the motor 18 to rotate forward (rotate in the direction of arrow C in FIG. 11).

  For this reason, like the step 184 according to the first embodiment, the second clutch 68 is engaged, and the clutch gear 86 has a predetermined direction around its axis in one direction (the direction of arrow E in FIG. 11). Torque is applied. Since the external teeth 236 of the adapter 228 are engaged with the external teeth 88 of the clutch gear 86, a predetermined torque directed in one direction around the axis (direction of arrow G in FIG. 11) is applied to the adapter 228. Is done.

  Further, since the external teeth 236 of the first spring case 50 are engaged with the external teeth 236 of the adapter 228, a predetermined torque directed in one direction around the axis (in the direction of arrow G in FIG. 11) is applied to the adapter 228. Then, a predetermined torque is applied to the first spring case 50 (winding shaft 12) in the drawing direction (the direction of arrow A in FIG. 11). In other words, the winding shaft 12 is applied with a predetermined torque that resists the first urging force (the urging force directed in the winding direction) of the first main spring 58 described above. This assists the occupant withdrawing the webbing 16, so that the occupant can pull out the webbing 16 with a light force.

  Since the clutch spring 252 is supported on the boss portion 234 of the adapter 228, when the adapter 228 rotates in one direction around the axis (in the direction of arrow G in FIG. 11) as described above, the clutch spring 252 and the adapter 228 The holder 246, which is integrally rotated around the axis in one direction, and that engages the engaging portion 254 of the clutch spring 252 with the engaging groove 256, rotates following the clutch spring 252, and the pressing protrusion 262 of the holder 246 is locked. The engaging portion 260 of the spring 258 is pressed around one axis (in the direction of arrow G in FIG. 11). As a result, the lock spring 258 is rotated in one direction around its axis, and the ratchet disc 238 whose outer periphery is in close contact with the tip of the ratchet teeth 244 is rotated in one direction around the axis (in the direction of arrow G in FIG. 11). The

  When the processing in step 266 is completed, the process proceeds to next step 268.

  In step 268, ECU 170 determines whether or not buckle switch 180 is turned on, that is, whether or not the occupant who has pulled out webbing 16 has attached the webbing 16 by connecting the tongue plate to the buckle device. Only when the determination at step 268 is affirmative, the routine proceeds to the next step 270.

  In step 270, the ECU 170 and the driver 172 stop the output shaft 20 of the motor 18. For this reason, as in step 188 according to the first embodiment, the second clutch 68 is released, and the application of the predetermined torque to the winding shaft 12 by the driving force of the motor 18 is released. The When the processing in step 270 is completed, the process proceeds to next step 272.

  In step 272, ECU 170 and driver 172 start energization of solenoid body 152 of tension reducer 226 to turn on tension reducer 226. When energization of the solenoid main body 152 is started, the plunger 154 is drawn to the solenoid main body 152 side, the pawl 158 connected to the tip of the plunger 154 rotates around the shaft 164, and the pawl 168 of the pawl 158 is engaged. Engages with the ratchet teeth 242 of the ratchet disc 238. Accordingly, the pawl 158 restricts the rotation of the ratchet board 238 around the axis line in the other direction (the direction indicated by the arrow H in FIG. 11).

  In this state, when the winding shaft 12 rotates together with the first spring case 50 in the winding direction (arrow B direction in FIG. 11), the adapter 228 is rotated around the axis in the other direction (arrow H direction in FIG. 11). . For this reason, the clutch spring 252 supported by the boss portion 234 of the adapter 228 rotates together with the adapter 228 in the other direction around the axis (in the direction indicated by the arrow H in FIG. 11), and the locking portion 254 of the clutch spring 252 is moved into the locking groove. The holder 246 locked to 256 is rotated in the other direction (in the direction of arrow H in FIG. 11) about its axis. Therefore, the pressing portion 261 of the holder 246 presses the distal end side of the engaging portion 260 of the clutch spring 252 in the other direction around the axis (the direction indicated by the arrow H in FIG. 11), and the leading end of the engaging portion 260 is the ratchet of the ratchet board 238. Closely engages the teeth 244. As a result, the holder 246 and the ratchet board 238 are integrally connected via the lock spring 258, and the rotation of the holder 246 around the axis of the holder 246 is restricted in the other direction, and the axis of the engaging portion 254 of the clutch spring 252 is around The rotation in the other direction is restricted.

  In this state, when the winding shaft 12 is further rotated in the winding direction together with the first spring case 50 and the adapter 228 is rotated in the other direction around the axis, the inner peripheral portion of the clutch spring 252 and the outer periphery of the boss portion 234 are obtained. The clutch spring 252 is wound and contracted by sliding contact with the surface, and a predetermined drag (friction force) is applied to the rotation of the adapter 228 in the other direction around the axis with respect to the clutch spring 252 (the clutch spring 252 causes the adapter to Brake torque is applied to rotation in the other direction around the axis 228). For this reason, the predetermined drag acts on the first spring case 50 connected to the adapter 228. As a result, the first urging force of the first spring 58 is applied to the winding shaft 12 by the predetermined drag. It works by being reduced (offset) by the amount. Therefore, the webbing take-up force of the take-up shaft 12 due to the first urging force of the first mainspring spring 58 is reduced, and it is possible to prevent the occupant wearing the webbing 16 from giving a feeling of pressure.

  When the processing in step 272 is completed, the process proceeds to next step 274.

  In step 274, the ECU 170 determines whether or not the mounted webbing 16 has been pulled out, for example, based on a detection signal from the winding shaft rotation detection sensor 176, such as when the occupant wearing the webbing 16 takes a forward bending posture. Judgment. If the determination in step 274 is affirmed, the process proceeds to step 276. On the other hand, if the determination in step 274 is negative, the process proceeds to step 282.

  When the determination in step 274 is affirmed and the process proceeds to step 276, in this step 276, the ECU 170 and the driver 172 cause the output shaft 20 of the motor 18 to rotate forward. For this reason, as in step 266 described above, the second clutch 68 is engaged, and a predetermined torque directed in the pulling direction (the direction of arrow B in FIG. 11) is applied to the first spring case 50 (winding shaft 12). Is granted. As a result, the webbing 16 is assisted to be pulled out, so that it is possible to prevent the occupant trying to take a forward bending posture from giving a feeling of pressure.

  At this time, the clutch spring 252 supported by the boss 234 of the adapter 228 is rotated in one direction around the axis (in the direction of arrow G in FIG. 11) integrally with the adapter 228, and the locking portion 254 of the clutch spring 252 is The holder 246 locked in the locking groove 256 rotates following the clutch spring 252, and the pressing protrusion 262 of the holder 246 moves the engagement portion 260 of the lock spring 258 in one direction around the axis (in the direction of arrow G in FIG. 11). Press. As a result, the engaging portion 260 of the lock spring 258 is separated from the ratchet teeth 244 of the ratchet board 238, and the connection state between the holder 246 and the ratchet board 238 by the lock spring 258 is released. As a result, the adapter 228, the clutch spring 252, the holder 246, and the lock spring 258 can freely rotate relative to the ratchet board 238 in one direction around the axis (in the direction of arrow G in FIG. 11). In this case, the adapter 228, the clutch spring 258, the holder 246, and the lock spring 258 are silenced with respect to the ratchet board 238 while the outer periphery of the lock spring 258 slides on the tip of the ratchet teeth 244 of the ratchet board 238. Relative rotation.

  When the processing in step 276 is completed, the process proceeds to next step 278.

  In step 278, the ECU 170 determines, based on the detection signal from the take-up shaft rotation detection sensor 176, for example, whether or not the webbing 16 has been pulled out by returning the occupant from the forward bent posture to the normal posture. Only when this determination is affirmed, the process proceeds to the next step 280.

  In step 280, the ECU 170 and the driver 172 stop the output shaft 20 of the motor 18. For this reason, as in step 270 described above, the connected state of the second clutch 68 is released, and the application of the predetermined torque to the winding shaft 12 by the driving force of the motor 18 is released. For this reason, the winding shaft 12 is rotated in the winding direction by the reduced urging force of the first mainspring spring 58, and the slack of the webbing 16 is removed.

  When the processing in step 280 is completed, the processing returns to the above-described step 274 and the above-described processing is repeated.

  On the other hand, if the determination in step 274 described above is denied and the process proceeds to step 282, in this step 282, whether or not the buckle switch 180 is turned off, that is, the occupant releases the connection between the tongue plate and the buckle device. Then, ECU 170 determines whether or not the webbing 16 is released. Only when this determination is affirmed, the process proceeds to the next step 284.

  In step 284, the ECU 170 and the driver 172 cut off the energization of the tension reducer 114 to the solenoid body 152 to turn off the tension reducer 114. Therefore, the plunger 154 of the solenoid 150 is pulled out of the solenoid body 152 by the urging force of the return spring 156, the pawl 158 connected to the plunger 154 rotates around the shaft 164, and the pawl 168 of the pawl 158 is ratchet. Separate from the ratchet teeth 242 of the disc 238. As a result, the ratchet board 238 can be rotated around the axis in the other direction (the direction indicated by the arrow H in FIG. 11). In this state, even if the locking portion 254 of the lock spring 258 engages with the ratchet teeth 244 of the ratchet board 238, the other around the axis of the holder 246 (the locking portion 254 of the clutch spring 252) (in the direction of arrow H in FIG. 11) ) Is not restricted, so that the application of the predetermined resistance against rotation in the other direction around the axis of the adapter 228 (in the direction of arrow H in FIG. 11) is also released. Accordingly, the take-up shaft 12 is rotated in the take-up direction by the first urging force of the first mainspring spring 58, whereby the webbing 16 is taken up by the take-up shaft 12. When the processing in step 284 is completed, the process proceeds to next step 286.

  In step 286, the ECU 170 and the driver 172 cause the output shaft 20 of the motor 18 to rotate forward. For this reason, as in step 204 according to the first embodiment, the first spring case 50 (winding shaft 12) is given a predetermined torque directed in the pull-out direction, and the first spring spring 58 has a first torque. The winding force of the winding shaft 12 based on the urging force is reduced. This prevents the webbing 16 from being taken up rapidly. Therefore, for example, it is possible to avoid collision between the tongue plate and the door trim due to rapid winding of the webbing 16, occurrence of a so-called end lock, or the like. Note that the motor 18 has a predetermined opportunity (for example, when a predetermined time has elapsed since the normal rotation, or when the webbing 16 has been wound up by a predetermined amount, as in step 204 according to the first embodiment, or The webbing 16 is stopped when all the webbing 16 is stored.

  When the processing in step 286 is finished, the drive control program according to the second embodiment is finished.

  As described above, the webbing take-up device 220 according to the second embodiment of the present invention has basically the same operational effects as the webbing take-up device 10 according to the first embodiment. In addition, a comfortable webbing pull-out property can be secured without hindering the function of the tension reducer 226.

  Moreover, in the webbing take-up device 220 according to the second embodiment of the present invention, the driving force of the motor 18 is transmitted to the take-up shaft 12 via the adapter 228 of the tension reducer 226. The configuration is simple.

  Further, in the tension reducer 226 of the webbing take-up shaft 220 according to the second embodiment of the present invention, the webbing take-up force of the take-up shaft 12 is provided by applying a predetermined drag force to the rotation of the adapter 228 by the clutch spring 252. Therefore, the mechanism is simple and the apparatus can be miniaturized.

  In the webbing take-up device 220 according to the second embodiment, when the take-up shaft rotation detection sensor 176 detects the webbing 16 being pulled out while the occupant is wearing the webbing, the ECU 170 and the driver 172 are connected to the solenoid body. It is good also as a structure which interrupts | blocks the electricity supply to 152. That is, the engagement state between the engagement pawl 168 of the pawl 158 and the ratchet teeth 242 of the ratchet board 238 may be released in conjunction with the pulling out of the webbing 16. In this case, the one-way clutch mechanism by the holder 246, the lock spring 258, and the ratchet board 238 can be abolished (the lock spring 258 can be abolished so that the holder 246 and the ratchet board 238 are integrated), and the device can be It can be made simpler.

  Further, in the drive control program according to the second embodiment, a process for turning on the tension reducer 226 may be provided instead of step 286. Even in this case, a drag force can be applied to the rotation of the winding shaft 12 in the winding direction, and the webbing 16 can be prevented from being rapidly wound.

It is front sectional drawing which shows the structure of the principal part of the webbing winding device concerning a 1st embodiment of the present invention. It is a disassembled perspective view which shows the structure of the principal part of the webbing winding device concerning a 1st embodiment of the present invention. It is side surface sectional drawing which shows the structure of the principal part of the webbing winding device concerning a 1st embodiment of the present invention. It is sectional drawing which followed the 3-3 line of FIG. 3 which shows the structure of the principal part of the webbing winding apparatus which concerns on the 1st Embodiment of this invention. It is a disassembled perspective view which shows the structure of the 2nd clutch which is a structural member of the webbing winding apparatus which concerns on the 1st Embodiment of this invention. It is a disassembled perspective view which shows the structure of the 2nd clutch which is a structural member of the webbing winding apparatus which concerns on the 1st Embodiment of this invention. It is a disassembled perspective view which shows the structure of the tension reducer which is a structural member of the webbing take-up device according to the first embodiment of the present invention. It is a disassembled perspective view which shows the structure of the tension reducer which is a structural member of the webbing take-up device according to the first embodiment of the present invention. The structure of the tension reducer which is a structural member of the webbing take-up device according to the first embodiment of the present invention is shown. (A) shows the other direction (adapter 120) of the pulling direction biasing member by the regulating means in the other direction. It is a top view which shows the state by which the displacement regulation of (2) was cancelled | released, (B) is a top view which shows the state by which the displacement to the other direction of the other end (adapter 120) of the drawing direction biasing member was controlled by the control means. is there. It is a flowchart which shows the control procedure of the control means which is a structural member of the webbing winding device concerning a 1st embodiment of the present invention. It is a disassembled perspective view which shows the structure of the principal part of the webbing winding device concerning a 2nd embodiment of the present invention. It is side surface sectional drawing which shows the structure of the principal part of the webbing winding apparatus which concerns on the 2nd Embodiment of this invention. FIG. 15 is a cross-sectional view taken along line 5-5 in FIG. 12 showing the configuration of the main part of the webbing take-up device according to the second embodiment of the present invention. It is a disassembled perspective view which shows the structure of the tension reducer which is a structural member of the webbing take-up device according to the second embodiment of the present invention. It is a disassembled perspective view which shows the structure of the tension reducer which is a structural member of the webbing take-up device according to the second embodiment of the present invention. The structure of the tension reducer which is a structural member of the webbing take-up device according to the second embodiment of the present invention is shown, and (A) shows a state in which the displacement restriction at one end in the winding direction of the drag applying member by the restricting means is released. It is a top view to show, (B) is a top view which shows the state by which the displacement of the drag provision member was controlled by the control means. It is a flowchart which shows the control procedure of the control means which is a structural member 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 16 Webbing 18 Motor 58 1st main spring (biasing member)
68 Tension reducer 122 Second spring case (rotating body)
130 Second spring (drawing direction biasing member)
124 Adapter (regulation means)
132 Ratchet board (regulation means)
144 Cushion spring (regulation means)
158 Paul (regulatory means)
150 Solenoid (regulation means)
170 ECU (control means)
172 Driver (control means)
176 Winding shaft rotation detection sensor (control means)
178 Magnet (control means)
180 Buckle switch (control means)
220 Webbing take-up device 226 Tension reducer 228 Adapter (rotating body)
238 Ratchet board (regulation means)
246 Holder (Regulator)
252 Clutch spring (Drag member)
258 Lock spring (regulation means)

Claims (7)

A winding shaft on which a webbing for restraining an occupant is wound so as to be retractable; and
A biasing member that biases the winding shaft in the webbing winding direction with a predetermined biasing force;
A tension reducer that reduces the predetermined urging force of the urging member by being turned on to be applied to the winding shaft, and releases the reduced state by being turned off.
A motor connected to the winding shaft and applying a predetermined torque directed to the winding shaft in the webbing pull-out direction by a driving force;
When the occupant pulls out the webbing, the motor is driven, and when the occupant wears the webbing, the motor is stopped and the tension reducer is turned on. Control means for turning off the tension reducer when the mounted state is released;
A webbing take-up device comprising: The tension reducer is
Connected to the take-up shaft, and rotates in one direction when the take-up shaft rotates in the webbing pull-out direction, and rotates in the other direction when the take-up shaft rotates in the webbing take-up direction. A rotating body,
One end is connected to the rotating body and rotates integrally with the rotating body, and when the rotating body rotates in the other direction with the rotation of the other end restricted in the other direction, the rotating body A pulling direction biasing member for applying a biasing force in the one direction to
Restricting means for restricting rotation of the other end of the pull-out direction biasing member in the other direction by being in the on state and releasing the rotation restriction by being in the off state;
The webbing retractor according to claim 1, further comprising:   The control means drives the motor when the webbing is first pulled out after the occupant wears the webbing, and stops the motor when the drawing is released. The webbing retractor according to claim 2. The tension reducer is
Connected to the take-up shaft, and rotates in one direction when the take-up shaft rotates in the webbing pull-out direction, and rotates in the other direction when the take-up shaft rotates in the webbing take-up direction. A rotating body,
A drag applying member that is supported by the rotating body and that slides with the rotating body when the rotating body rotates in a state in which the rotation of the rotating body is restricted, and applies a predetermined drag to the rotation of the rotating body;
A restricting means for restricting the rotation of the drag applying member only when the rotating body rotates in the other direction in the on state;
The webbing retractor according to claim 1, further comprising:   The control means drives the motor when the webbing is pulled out while the occupant is wearing the webbing, and stops the motor when the pulling is released. 4. The webbing take-up device according to 4.   The motor is connected to the rotating body of the tension reducer, and the rotating body is rotated in the other direction when the driving force of the motor is transmitted to rotate the winding shaft in the webbing pull-out direction. The webbing retractor according to any one of claims 2 to 5, wherein:   The webbing retractor according to any one of claims 1 to 6, wherein the control means drives the motor immediately after the occupant releases the webbing wearing state.

Images