JP2005225307A - Seat belt device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat belt device which has a driving means for taking up a waving belt of a motor and so forth, and also, does not require a special trigger means dedicated for a tension reducer. <P>SOLUTION: This seat belt device has a structure that the driving force of the motor 70 which imparts a rotating force in the taking-up direction to a spool 28 is transmitted to a pawl 100 through gears 84 through 96, and thus, a cam 104 is pressed by the rocking pawl 100, and an engaging claw 120 is engaged with a ratchet gear of a ratchet wheel 58 of the tension reducer 52. Thus, the special trigger means such as a solenoid for restricting the rotation of the ratchet wheel 58 becomes unnecessary. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a seat belt device for restraining the body of an occupant seated on a seat by a webbing belt.

  A seat belt device provided in a vehicle includes a webbing take-up device for storing a long belt-like webbing belt having flexibility for restraining the body of an occupant seated in a seat. It is disclosed in Patent Document 1. Hereinafter, the webbing retractor disclosed in Patent Document 1 will be briefly described.

  The webbing take-up device disclosed in Patent Document 1 includes a spool. The longitudinal base end of the webbing belt is locked to the spool, and the webbing belt is wound around the spool from the proximal end when the spool is rotated in the winding direction which is one of the directions around the axis. ing. Further, a mainspring unit is provided at one end side in the axial direction of the spool, and the spool is biased in the winding direction by the biasing force of the spring of the mainspring unit.

  Further, a planetary gear train is provided on one end side of the spool in the axial direction. The planetary gear train includes a carrier gear that is integrally connected to the spool. A ratchet gear is formed on the outer peripheral portion of the carrier gear, and an external gear is integrally formed on one side in the axial direction of the ratchet gear.

  Further, three reduction pins are integrally attached around the axis of the carrier gear, and planetary gears are rotatably supported by each. The planetary gear meshes with the inner teeth of the ring-shaped internal gear on the outer peripheral side of the carrier gear. A ratchet gear is formed on the outer peripheral portion of the internal gear.

  On the other hand, the planetary gear meshes with the sun gear on the center side of the carrier gear. The sun gear is connected to the output shaft of the motor via a reduction gear. A connect gear is interposed between the reduction gear and the motor. A base end portion of a lever spring is attached to the shaft portion of the connect gear. A locking lever is attached to the tip of the lever spring.

  When the motor is driven forward or reverse, the connecting gear is rotated by the driving force of the motor, and the locking lever is swung in a direction approaching the ratchet gear of the internal gear. When the locking lever approaches the ratchet gear of the internal gear and engages with the ratchet gear, the rotation of the internal gear is restricted.

  In this state, when the motor continues to drive in the forward or reverse direction, the rotational force of the motor is transmitted to the sun gear via the connect gear and the reduction gear, and the sun gear rotates. In this state, since the rotation of the internal gear is restricted, the planetary gear that rotates in response to the rotation of the sun gear revolves around the sun gear while rotating around the reduction pin. The revolution of the planetary gear rotates the carrier gear, and the spool winds up the webbing belt.

  On the other hand, when the motor rotates in the forward or reverse direction, the locking lever does not engage with the ratchet gear of the internal gear, so that the internal gear is rotatable. Therefore, even if the sun gear is rotated by the driving force of the motor in this state, and the rotation of the sun gear is transmitted to the planetary gear, the planetary gear transmits the rotational force to the internal gear and rotates the internal gear. It only rotates around the reduction pin and does not revolve around the sun gear. Therefore, in this state, the rotational force is not transmitted to the spool.

In other words, the planetary gear train constitutes a clutch that is interposed between the motor and the spool.
JP 2002-212355 A

  Incidentally, in the webbing take-up device disclosed in Patent Document 1, the webbing belt is normally taken up by the urging force of the spiral spring provided in the mainspring unit. That is, in order to pull out the webbing belt, the spool rotates in the pulling direction opposite to the winding direction. One end of the spiral spring is indirectly connected to the spool, and the urging force increases as the amount of rotation in the pull-out direction of the spool increases. When storing the webbing belt, the spool is Rotate in the winding direction.

  Here, in the structure in which the spool is urged in the winding direction by the urging force of the spiral spring, the spool is urged in the direction of winding the webbing belt even in normal times without any particular danger. An occupant wearing the vehicle may feel a sense of pressure.

  In order to eliminate such a feeling of pressure, the urging force of the spiral spring itself may be weakened. However, if the urging force of the spiral spring is weakened, the force with which the spool winds the webbing belt when the webbing belt is removed is weakened, making it difficult to quickly store the webbing belt.

  Therefore, a tension reducer that reduces the urging force that is applied to the spool in the normal direction and reduces the urging force that is applied to the spool in a normal state, and applies sufficient urging force to the spool in the winding direction when the webbing belt is removed or in an emergency. A webbing take-up device is provided.

  This type of tension reducer includes a biasing member such as a spiral spring that is different from a normal spiral spring. For example, in a planetary gear train as described above, any one of preset carriers, internals, etc. When one rotation is restricted, the urging force of the urging member acts against the urging force of the normal spiral spring to substantially cancel a part of the urging force of the spiral spring. Thereby, the tension of the webbing belt based on the urging force of the spiral spring is reduced, and the feeling of pressure is reduced.

  By the way, in such a tension reducer, when a planetary gear train is used, as described above, any one of preset rotations such as a carrier, an internal, etc. is restricted. There is a problem that special trigger means such as a solenoid must be provided, which increases the size and cost of the apparatus.

  In view of the above facts, an object of the present invention is to provide a seat belt device that has a driving unit for winding a webbing belt such as a motor and does not require a special trigger unit dedicated to a tension reducer. .

  The seat belt device according to the first aspect of the present invention is a long belt that is wound around the spool by rotation of the spool in a winding direction in which a longitudinal base end is locked to the spool and is around one axis. A belt-like webbing belt is attached to the body of the occupant seated in the seat, thereby restraining the body of the occupant and the urging force of the urging means coupled directly or indirectly to the spool A seat belt device including a webbing take-up device that increases in accordance with an increase in the amount of rotation of the spool in a pull-out direction opposite to the take-up direction and biases the spool in the take-up direction. A displacement member that is displaced in conjunction with the rotation of the spool, and canceling at least a part of the urging force applied to the spool by the urging means by restricting the displacement of the displacement member or releasing the restriction. Has a tension reducer that applies an external force in the same direction as the urging force to the spool together with an urging force of the urging means, and an output shaft that is rotated by a driving force, and the output shaft is connected to the spool. By rotating the output shaft with the driving force, a driving means for applying a rotational force in a winding direction or a pulling direction to the spool, and a forward rotation driving of the driving means connected to the output shaft of the driving means. Limiting the displacement of the displacement member by engaging the displacement member by forward rotation of the output shaft due to force, and releasing the engagement by reverse rotation of the output shaft by the reverse drive force of the drive means Means.

  According to the seat belt device of the first aspect of the present invention, when the spool of the webbing take-up device is rotated in the take-up direction which is one of the axes around the shaft, the longitudinal base end is locked to the spool. A long belt-like webbing belt is wound around a spool from the base end side and stored. In addition, for example, when an occupant seated in a vehicle seat pulls the webbing belt to the front end side in order to attach the webbing belt, the spool is pulled in the pull-out direction opposite to the winding direction due to the tension applied to the webbing belt. The webbing belt wound around the spool is pulled out.

  With the occupant sitting on the seat with the webbing belt pulled out in this way, for example, a tongue plate provided in the middle in the longitudinal direction of the webbing belt is provided on the side of the seat, etc. By attaching to the buckle device, the webbing belt is attached to the occupant's body, and the occupant's body is restrained by the webbing belt.

  Further, when the webbing belt is pulled out in order to mount the webbing belt in this way and the spool is rotated in the pulling-out direction along with this, the urging force of the urging means connected directly or indirectly to the spool is changed in the pulling-out direction. It increases according to the amount of rotation of the spool. Since this urging force urges the spool in the winding direction, for example, when the engagement between the tongue plate and the buckle device is released, the spool rotates in the winding direction by the urging force of the urging means. Is wound from the base end side and stored.

  On the other hand, in the seat belt device according to the present invention, when the drive means is driven and the output shaft rotates while the output shaft is coupled to the spool, the rotation of the output shaft is transmitted to the spool, and the spool is retracted in the winding direction or the pull-out direction Rotate in the direction. When the occupant is wearing the webbing belt, the spool is forcibly rotated in the winding direction by the driving force of the driving means, and the webbing belt is forcibly taken up by the spool, thereby loosening the webbing belt. Is removed, and the binding force by the webbing belt increases. Thereby, a passenger | crew's body can be restrained still more strongly with a webbing belt.

  Further, when the occupant is wearing the webbing belt, the spool is forcibly rotated in the pull-out direction by the driving force of the driving means, so that the webbing belt is loosened and the restraining force by the webbing belt is reduced. Therefore, after the spool is forcibly rotated in the take-up direction as described above to increase the restraining force, the spool is forcibly rotated in the pull-out direction, so that the strong compression applied to the passenger due to the increase in the restraining force. The feeling can be reduced.

  On the other hand, as described above, when the driving means is driven to rotate forward and the output shaft rotates forward, the limiting member engages with the displacement member of the tension reducer. Further, when the output shaft is rotated reversely by driving the drive means in reverse, the engagement of the limiting member with the displacement member is released.

  Although the displacement member can be displaced in conjunction with the rotation of the spool, the displacement of the displacement member is restricted by the engagement of the restriction member with the displacement member. When the displacement of the displacement member is restricted or the restriction on the displacement of the displacement member is released, at least a part of the urging force applied to the spool from the urging means is canceled, or the urging force of the urging means An external force in the same direction is applied to the spool.

  The biasing force of the biasing means acts to rotate the spool in the winding direction, and the spool is biased in the winding direction by the biasing force of the biasing means, so that the webbing belt is free from loosening and the like. At the same time, the occupant's body is restrained by the webbing belt with a restraining force corresponding to the magnitude of the urging force.

  Therefore, when at least a part of the urging force is canceled as described above, the rotational force of the spool in the winding direction is weakened, thereby reducing the restraining force of the webbing belt restraining the occupant's body, Can reduce the feeling of pressure.

  Further, when an external force in the same direction as the urging force of the urging means is applied to the spool, a rotational force in the winding direction based on the external force is applied in addition to the urging force. Will increase the rotational force. Thereby, the restraining force with which the webbing belt restrains the occupant's body is strengthened, and the occupant's body can be restrained more reliably.

  As described above, in the seat belt device according to the present invention, the tension reducer operates or the tension reducer operates by driving the driving means for forcibly rotating the spool in the winding direction or the drawing direction. Since it is released, a special trigger means such as a solenoid for operating the tension reducer or releasing the operation becomes unnecessary. Thereby, component cost and assembly cost can be reduced, and as a result, the cost of the entire seat belt device can be reduced.

  In addition, since the trigger means as described above is unnecessary, the tension reducer can be reduced in size and weight by the installation space and operation space of the trigger means, and the entire seat belt device can be reduced in size and weight. Can do.

  Further, as described above, the tension reducer is operated or released by rotating the output shaft by the driving force of the driving means, but the spool is forcibly taken up by the driving force of the driving means. It is rotated in the pull-out direction. That is, in the seat belt device according to the present invention, the forced rotation of the spool by the driving force of the driving means and the tension reducer can be interlocked without any special control, and the level of the binding force of the webbing belt can be increased. Therefore, it is possible to give the occupant a feeling that the restraining force naturally increases or decreases.

  In the present invention, the output shaft of the driving means may be configured to be always connected to the spool, or the output shaft and the spool can be connected and disconnected, and the output is output when the connection is released. A configuration may be adopted in which the rotational force of the shaft (that is, the driving force of the driving means) is not transmitted to the spool and the spool is not rotated by the driving force of the driving means.

  In the present invention, the driving condition of the driving means is not particularly limited, and the driving conditions may be set as appropriate. For example, when the occupant wears a webbing belt or such webbing The case where the belt is released can be considered, and the case where the distance to other vehicles or obstacles traveling in front of the vehicle is less than a predetermined value can also be considered.

  A seat belt device according to a second aspect of the present invention is the seat belt device according to the first aspect of the present invention, wherein the tongue plate provided at the intermediate portion in the longitudinal direction of the webbing belt can be engaged with the tongue plate. A buckle device that is attached to the seat or in the vicinity of the seat and holds the tongue plate by engaging with the tongue plate, and provided in the buckle device, and whether or not the tongue plate is engaged with the buckle device A tongue detecting means for detecting whether or not the rotation of the output shaft is transmitted to the spool as a rotation in the winding direction, and the connection between the output shaft and the spool is released in conjunction with the forward rotation of the output shaft. When the tongue plate is engaged with clutch means for interrupting rotation transmission of the output shaft to the spool, and the buckle device, The drive means is driven to rotate forward based on a signal output from the tongue detection means, and the drive means based on a signal output from the tongue detection means when the engagement of the tongue plate with the buckle device is released. And a control means for reversely driving, wherein the restriction member is engaged with the displacement member to cancel at least a part of the urging force of the urging means.

  In the seat belt device according to the second aspect of the present invention, when the occupant seated on the seat wears the webbing belt on the body and the tongue plate provided on the webbing belt is engaged with the buckle device, the tongue plate It is held by the buckle device, and thereby the webbing belt is put on. Further, when the tongue plate is engaged with the buckle device as described above, it is detected by the tongue detection means provided in the buckle device that the tongue plate is engaged with the buckle device.

  When the signal in this state is output from the tongue detection means, the drive means is driven to rotate forward by the control means. When the control means is rotated forward and the output shaft is rotated forward, the limiting means is engaged with the displacement member of the tension reducer. Thus, at least a part of the urging force of the urging means for urging the spool in the winding direction is canceled by the engagement of the limiting means with the displacement member. Accordingly, it is possible to reduce the feeling of pressure that the occupant wearing the webbing belt receives from the webbing belt.

  In addition, when the drive means is driven forward as described above, the output shaft rotates forward, but the clutch means provided between the output shaft and the spool is linked with the output shaft and the spool in conjunction with the forward rotation of the output shaft. Release the link. As a result, the rotational force of the output shaft during forward rotation is not transmitted to the spool.

  On the other hand, when getting off the vehicle, when the engagement between the tongue plate and the buckle device is released in order to remove the webbing belt worn by the occupant, the release of the engagement is detected by the tongue detection means. When a signal in this state is output from the tongue detection means, the drive means is driven in reverse by the control means.

  When the drive means is driven in reverse and the output shaft is reversely rotated, the engagement between the limiting means and the displacement member of the tension reducer is released. In the engaged state of the restricting means with respect to the displacement member, at least a part of the urging means has been canceled, but as described above, the urging force of the urging means is released by releasing the engagement of the restricting means with respect to the displacement member. This offset is also cancelled. Thus, the spool is urged in the winding direction by the urging force of the original urging means that is not offset.

  Here, in this state, since the engagement between the tongue plate and the buckle device is released, that is, the tongue plate is removed from the buckle device, if the spool rotates in the winding direction, the webbing belt is attached to the spool. It is wound up and stored. Therefore, in this state, the spool is rotated in the winding direction by the urging force of the original urging means that is not canceled out, and the webbing belt can be quickly taken up and stored in the spool.

  On the other hand, as described above, when the drive means is reversely driven and the output shaft is reversely rotated, the clutch means connects the output shaft and the spool, transmits the rotation of the output shaft to the spool, and winds the spool in the winding direction. Force to rotate. Therefore, in this state, the spool rotates in the winding direction also by the driving force of the driving means, and the webbing belt is wound up. Thus, the webbing belt can be quickly wound around the spool and stored by the urging force of the urging means and the driving force of the driving means.

  A seat belt device according to a third aspect of the present invention is the seat belt device according to the first or second aspect of the present invention, wherein the seat belt device is interposed between the output shaft and the spool and decelerates the rotation of the output shaft. A limiting member that is directly or indirectly provided on the reduction gear that is transmitted to the spool, and that engages and disengages the displacement member by moving toward and away from the displacement member by rotation of the reduction gear. The limiting means is used.

  In the seatbelt device according to the third aspect of the present invention, a reduction gear is interposed between the output shaft and the spool, and the driving means is driven in a state where the output shaft and the spool are connected. Therefore, the rotation of the output shaft is decelerated and transmitted to the spool.

  The reduction gear is provided with a restriction member that constitutes a restriction means. When the rotation of the output shaft is transmitted to the reduction gear and the reduction gear rotates, the restriction member moves toward and away from the displacement member. Due to the contact / separation movement of the restriction member with respect to the displacement member, the displacement member is engaged with the restriction member, or the engagement of the restriction member with respect to the displacement member is released.

  Thus, in this seatbelt device, since the limiting member is provided on the reduction gear that decelerates the rotation of the output shaft and transmits it to the spool, the amount of movement of the limiting member is determined according to the amount of rotation of the reduction gear.

  In other words, by using a reduction gear having a reduction ratio (gear ratio) corresponding to the amount of movement required for the restriction member to engage and disengage from the displacement member, the reduction means only for the restriction member Is no longer necessary. As a result, the configuration can be simplified, the cost can be reduced, and the entire apparatus can be downsized.

  A seat belt device according to a fourth aspect of the present invention is the seat belt device according to any one of the first to third aspects, wherein the seat belt device is directly or indirectly connected to the output shaft. A rotating body that rotates around its own axis in conjunction with rotation, and attached to the rotating body, and moves around the axis of the rotating body to move toward and away from the displacement member, and the contact and separation movement. A restricting member that engages and disengages with the displacement member, and connects the restricting member to the rotating body to rotate the restricting member integrally with the rotating body, and the restricting member becomes the displacement member. When an external force of a predetermined magnitude or more in a direction opposite to the rotation direction of the limiting member when engaged is applied to the limiting member, the connection between the limiting member and the rotating body is released, Connection for rotating the rotating body relative to the limiting member And forming the limiting means including a timber, a, is characterized in that.

  In the seat belt device according to the fourth aspect of the present invention, when the output shaft rotates, the rotating body rotates in the direction around its own axis in conjunction with the rotation. When the rotating body rotates in this way, the limiting member connected to the rotating body via the connecting member rotates together with the rotating body, and thereby the limiting member moves toward and away from the displacement member of the tension reducer. The restriction member engages with the displacement member by moving the restriction member toward and away from the displacement member, and the engagement of the restriction member with the displacement member is released.

  By the way, when the rotation amount of the output shaft based on the driving force of the driving means and the rotation amount of the limiting member until the limiting member engages with the displacing member do not strictly correspond, the limiting member is engaged with the displacing member. Even if they are combined, there is a possibility that the limiting member may apply an unnecessary external force to the displacement member in an attempt to rotate in the rotation direction when the limiting member is engaged with the displacement member.

  Here, in the seat belt device according to the present invention, when an external force of a predetermined magnitude or more in a direction opposite to the rotation direction of the limiting member when engaging the displacement member acts on the limiting member, the connecting member is the limiting member. And the connection with the rotating body is released. Therefore, when the rotating member further rotates with the limiting member engaged with the displacement member, and a pressing reaction force of a predetermined magnitude or more from the displacement member engaged with the limiting member acts on the limiting member, the rotating member and the limiting member are restricted. The connection with the member is released and only the rotating body rotates.

  Thereby, it can prevent that a limiting member provides an excessive pressing force to a displacement member. Further, it is possible to prevent the rotation of the rotating body from being restricted by the displacement member being restricted from rotating, and as a result, the output shaft can be rotated even if the restriction member is restricted from turning. .

  As described above, the seat belt device according to the present invention does not require a special trigger means such as a solenoid for operating the tension reducer or releasing the operation. Thereby, component cost and assembly cost can be reduced, and as a result, the cost of the entire seat belt device can be reduced.

  In addition, since the trigger means as described above is unnecessary, the tension reducer can be reduced in size and weight by the installation space and operation space of the trigger means, and the entire seat belt device can be reduced in size and weight. Can do.

<Configuration of the present embodiment>
FIG. 2 is a side view schematically showing the overall configuration of the seat belt device 10 according to one embodiment of the present invention. As shown in this figure, the seat belt device 10 includes a webbing retractor 12. The webbing take-up device 12 is provided on the rear side of the driver's seat 16 of the vehicle 14 and below the center pillar 18 of the vehicle 14.

  As shown in FIG. 1, the webbing retractor 12 includes a frame 20. The frame 20 includes a pair of leg plates 22 and 24. These leg plates 22 and 24 are arranged in parallel with each other facing each other in the thickness direction.

  One end in the width direction of these leg plates 22 and 24 is connected by a back plate 26, and although not shown in particular, the frame 20 is open in a plan view in a generally concave shape in a plan view. It has become. By attaching the back plate 26 to the vehicle body at a predetermined position of the vehicle 14, the webbing take-up device 12 is fixed to the vehicle body below the center pillar 18.

  In addition, the webbing take-up device 12 includes a spool 28. The spool 28 is formed in a substantially cylindrical shape in the axial direction along the opposing direction of the leg plates 22, 24, and a webbing belt 30 formed in a long band shape is wound around the outer peripheral portion in a layered manner from the base end side in the longitudinal direction. Taken and stored. When the spool 28 rotates in the winding direction, which is one of the directions around the axis, the webbing belt 30 is sequentially wound around the spool 28 from the base end side.

  Further, when the webbing belt 30 is wound around the spool 28 and the webbing belt 30 is pulled toward the tip, the webbing belt 30 wound around the spool 28 is pulled out and the spool 28 is moved in the winding direction. Has a structure that rotates in the opposite withdrawal direction.

  As shown in FIG. 2, the front end side of the webbing belt 30 is extended along the center pillar 18 rather than the portion wound around the spool 28. A through anchor 32 is provided in the vicinity of the upper end portion of the center pillar 18. The through anchor 32 is formed in a substantially plate shape, and is attached to the vehicle body by a fastening member such as a bolt penetrating in the thickness direction so as to be rotatable about an axis whose axial direction is substantially the vehicle lateral direction. .

  The through anchor 32 is formed with a slit hole 34 whose longitudinal dimension is longer than the width dimension of the webbing belt 30. The webbing belt 30 passes through the slit hole 34 and is folded back substantially downward in the vehicle while being supported by the through anchor 32.

  The front end portion of the webbing belt 30 folded back by the through anchor 32 is locked to an anchor plate 36 provided on the rear side of the driver seat 16 of the vehicle 14 and below the center pillar 18 of the vehicle 14. Further, a tongue plate 38 is provided between the folded portion of the through anchor 32 of the webbing belt 30 and the tip portion. A slit hole 40 having a longitudinal dimension longer than the width dimension of the webbing belt 30 is formed in the tongue plate 38, and the webbing belt 30 passes through the slit hole 40.

  On the other hand, a buckle device 42 is provided on the opposite side of the driver seat 16 from the webbing take-up device 12 and the anchor plate 36. In the buckle device 42, when the distal end side of the tongue plate 38 is inserted into a substantially box-shaped main body portion, a locking member such as a latch provided inside the main body portion enters a hole formed in the tongue plate 38, The plate 38 is locked.

  An occupant seated in the driver's seat 16 pulls the webbing belt 30 while pulling the tongue plate 38 and locks the tongue plate 38 to the buckle device 42 to hold the webbing belt 30 on the tip side of the tongue plate 38. The waist is constrained, and the webbing belt 30 restrains the occupant's chest and the like on the proximal side of the tongue plate 38.

  The buckle device 42 is provided with a buckle switch 44 as a tongue detecting means. The buckle switch 44 is electrically connected to the tongue plate 38 inserted into the main body portion of the buckle device 42 or by engaging a locking member such as a latch with the tongue plate 38 inserted into the main body portion of the buckle device 42. Mechanical switch means.

  In this embodiment, the mechanical switch means is applied to the buckle switch 44. However, the buckle switch 44 has the tongue plate 38 inserted into the main body of the buckle device 42 as a result, or the buckle device 42. As long as it is a structure that can detect that a locking member such as a latch is engaged with the tongue plate 38 inserted in the main body portion of the present invention, it is not limited to mechanical switch means.

  Therefore, for example, a magnet (permanent magnet) interlocked with a locking member such as a tongue plate 38 or a latch inserted in the main body portion of the buckle device 42, and a hole for detecting the displacement of the magnet based on the magnetism change of the magnet. The switch means may be configured including a magnetic sensor such as an element or an MRE element.

  On the other hand, as shown in FIG. 1, a torsion shaft 46 is accommodated inside the spool 28 described above. The torsion shaft 46 is substantially coaxial with the spool 28 and is disposed so as to be rotatable relative to the spool 28 about its own axis. An adapter 48 is integrally connected to the end of the torsion shaft 46 on the axial leg plate 24 side. The outer peripheral portion of the adapter 48 is integrally coupled to the inner peripheral portion of the spool 28, so that the torsion shaft 46 is integrally connected to the spool 28 at the end on the axial leg plate 24 side.

  On the other hand, the adapter 50 is integrally connected to the end of the torsion shaft 46 on the axial leg plate 22 side. Although a part of the adapter 50 is fitted into the spool 28, the adapter 50 can rotate relative to the spool 28 coaxially. Further, the adapter 50 passes through the leg plate 22 and protrudes to the outside of the frame 20, and is connected to a lock mechanism (not shown) provided on the side of the leg plate 22.

  The lock mechanism (not shown) has a structure that locks the adapter 50 in a vehicle sudden deceleration state or the like and restricts the rotation of the adapter 50 in the pull-out direction opposite to the winding direction.

  On the other hand, a tension reducer 52 is provided outside the leg plate 24 (on the side opposite to the leg plate 22 via the leg plate 24). As shown in FIG. 4, the tension reducer 52 includes a case 54. The case 54 is generally formed in a box shape that opens toward the leg plate 24, and a part of the inside of the case 54 serves as a ratchet accommodating portion 56.

  A ratchet wheel 58 as a displacement member is coaxially disposed with respect to the spool 28 in the ratchet accommodating portion 56. A through hole 60 is formed in the center of the ratchet wheel 58. A shaft portion 62 extending coaxially from the adapter 48 passes through the through hole 60, and the ratchet wheel 58 is rotatably supported by the shaft portion 62.

  A cylindrical portion 64 is coaxially and integrally formed on the surface of the ratchet wheel 58 on the leg plate 24 side. A spiral spring 66 as an urging means is accommodated inside the cylindrical portion 64. The spiral spring 66 has an axial direction of the spiral direction that is the same as the axial direction of the spool 28, and the spiral direction inner end 66 </ b> A is integrally connected to a locking portion (not shown) formed on the shaft portion 62. Are locked. On the other hand, the spiral direction outer end 66 </ b> B of the spiral spring 66 is integrally connected to a locking portion (not shown) formed in the cylindrical portion 64.

  The spiral spring 66 has a spiral direction set so that the inner end 66A rotates in the pull-out direction with respect to the outer end 66B, and the inner end 66A rotates in the pull-out direction with respect to the outer end 66B. By being tightened, the biasing force that biases the inner end 66A in the winding direction is increased.

  A spiral spring 68 is provided outside the cylindrical portion 64. In the spiral spring 68, the axial direction of the spiral direction is the same as the axial direction of the spool 28, and the cylindrical portion 64 is located inside the vortex of the spiral spring 68. The spiral direction inner end 68 </ b> A of the spiral spring 68 is integrally connected and locked to a locking portion (not shown) formed in the cylindrical portion 64. On the other hand, the spiral direction outer end 68 </ b> B of the spiral spring 68 is integrally connected to a locking portion (not shown) formed in the case 54.

  Similarly to the spiral spring 66, the spiral spring 68 is set in a spiral direction so that the inner end 68A is wound by rotating in the pull-out direction with respect to the outer end 68B, and the inner end 68A is the outer end 68B. The urging force for urging the inner end 68A in the take-up direction is increased by rotating in the pull-out direction and being tightened.

  On the other hand, a motor 70 as a driving means is disposed below the spool 28 and between the leg plate 22 and the leg plate 24. The motor 70 is electrically connected to a battery 74 mounted on the vehicle 14 via a driver 72.

  The driver 72 is electrically connected to an ECU 76 as control means. The ECU 76 is electrically connected to the above-described buckle switch 44, and the ECU 76 operates the driver 72 based on a signal output from the buckle switch 44, and the driver 72 drives and controls the motor 70.

  On the other hand, as shown in FIGS. 1 and 3, a gear 80 is coaxially and integrally provided on the output shaft 78 of the motor 70. Above the gear 80 in the radial direction, a gear train 82 that constitutes a reduction means is provided. The gear train 82 includes a gear 84 having a larger diameter than the gear 80. The gear 84 meshes with the gear 80 in a state where it is rotatably supported around an axis parallel to the spool 28 by a support plate 86 provided between the leg plates 22 and 24.

  A gear 88 having a smaller diameter than the gear 84 is provided coaxially and integrally with the gear 84 on the side of the gear 84 in the axial direction.

  Further, a gear 90 that constitutes a gear train 82 together with the gears 84 and 88 is provided on the upper side in the radial direction of the gear 88. The gear 90 is engaged with the gear 88 around the axis parallel to the spool 28 by the support plate 86. It is pivotally supported. Further, a clutch 92 as a clutch means is provided on the upper side in the radial direction of the gear 90.

  The clutch 92 includes an outer peripheral ring 94. The outer peripheral ring 94 is provided coaxially with the spool 28, and external teeth formed on the outer peripheral portion mesh with the gear 90. Therefore, when the motor 70 is driven to rotate forward and the output shaft 78 is rotated forward, the rotational force in the pull-out direction, which is decelerated through the gear train 82, is applied to the outer ring 94, and the motor 70 is driven to rotate in the reverse direction. When 78 reversely rotates, the rotational force in the winding direction reduced through the gear train 82 is applied to the outer ring 94.

  An adapter (not shown) is coaxially and integrally provided on the shaft portion 62 of the adapter 50 inside the outer ring 94. Further, one or more pawls as connecting members are provided inside the outer peripheral ring 94. The pawl is pivotally supported by a shaft member that rotates integrally with the outer ring 94. The outer peripheral ring 94 is rotatable relative to the adapter around the axis of the spool 28. Therefore, even if the adapter rotates, the rotation of the adapter is not transmitted to the outer ring 94.

  However, when the outer peripheral ring 94 rotates in the winding direction, the pawl swings while rotating together with the outer peripheral ring 94 to engage the pawl with the adapter. Due to the engagement between the pawl and the adapter, the outer ring 94 and the adapter are mechanically connected via the pawl, and the rotation of the outer ring 94 in the winding direction is transmitted to the adapter via the pawl. (In summary, the clutch 92 can transmit the rotation of the outer peripheral ring 94 in the winding direction to the adapter, and thus the spool 28. However, the rotation of the outer peripheral ring 94 in the pull-out direction can be transmitted to the adapter, That is, the rotation of the spool 28 cannot be transmitted to the outer ring 94).

  On the other hand, a gear 96 is arranged on the side of the gear 90 in the radial direction. The gear 96 is provided with a shaft 98 that constitutes a limiting means as a rotating body coaxially and integrally. The shaft 98 passes through the leg plate 24, and the gear 96 meshes with the gear 90 in a state where the shaft 98 is rotatably supported on the leg plate 24 around an axis parallel to the spool 28.

  Further, a pawl 100 constituting a restricting means is integrally attached as a restricting member that enters the inside of the case 54 from a notch 102 formed in the case 54 at the tip end portion of the shaft 98 penetrating the leg plate 24. A cam 104 is provided on the inside of the case 54 corresponding to the pawl 100. The cam 104 is pivotally supported on a shaft 106 provided in the case 54 so as to be rotatable around an axis parallel to the spool 28.

  A contact portion 108 is provided on the cam 104. As shown in FIG. 5, the contact portion 108 is in contact with the pawl 100, and is rotated around the shaft 106 by being pressed by the pawl 100 that rotates when the gear 96 receives the normal rotation of the output shaft 78. To do.

  The cam 104 is provided with an engaging claw 110. The engaging claws 110 correspond to ratchet teeth formed on the outer peripheral portion of the ratchet wheel 58 of the tension reducer 52, and when the abutment portion 108 is pressed by the pawl 100 and the cam 104 rotates, it is shown in FIG. Thus, the engaging claw 110 approaches the ratchet wheel 58 and meshes with the ratchet teeth. In a state where the engaging claw 110 is engaged with the ratchet teeth of the ratchet wheel 58, the ratchet wheel 58 is allowed to rotate in the pull-out direction, but the rotation of the ratchet wheel 58 in the winding direction is restricted by the engaging claw 110. It has a configuration.

  Further, one end of the compression coil spring 112 is engaged with the contact portion 108 of the cam 104. The other end of the compression coil spring 112 is locked to, for example, a locking portion (not shown) formed on the inner peripheral portion of the case 54, and the engaging claw 110 is moved away from the ratchet teeth of the ratchet wheel 58. The contact portion 108 (that is, the cam 104) is urged.

<Operation and effect of the present embodiment>
Next, the operation and effect of this embodiment will be described.

  In the seat belt device 10, when an occupant sitting on the driver's seat 16 pulls out the webbing belt 30 wound around the spool 28, the spool 28 rotates in the pull-out direction due to the tension applied to the webbing belt 30 at this time. Thus, when the spool 28 rotates in the drawing direction, first, the inner end 66A of the spiral spring 66 rotates in the drawing direction.

  When the inner end 66A of the spiral spring 66 rotates in the pulling direction, the outer end 66B follows and tries to rotate in the pulling direction. However, the outer end 66B is connected to the inner end 68A of the spiral spring 68 having a spring coefficient larger than that of the spiral spring 66 through the cylindrical portion 64. For this reason, the outer end 66 </ b> B cannot rotate in the pull-out direction due to the elastic force of the spiral spring 68. Therefore, when the spool 28 rotates in the pull-out direction, the spiral spring 66 is first tightened, and the first biasing force that is the biasing force of the spiral spring 66 is increased.

  When the spiral spring 66 is further tightened by a certain amount from this state, the outer end 66B of the spiral spring 66 follows the inner end 66A and rotates in the drawing direction. This rotation is transmitted to the inner end 68A of the spiral spring 68 via the cylindrical portion 64, and rotates the inner end 68A in the pull-out direction.

  Since the outer end 68B of the spiral spring 68 is fixed to the case 54, it cannot follow the inner end and rotate in the pull-out direction. For this reason, when the inner end 68 </ b> A rotates in the pull-out direction, the spiral spring 68 is tightened, and the second biasing force that is the biasing force of the spiral spring 68 is increased. Therefore, in the present embodiment, when pulling out the webbing belt 30, the resultant force of the first urging force and the second urging force acts on the spool 28.

  Next, when the buckle switch 44 detects that the tongue plate 38 is attached to the buckle device 42, and the signal output from the buckle switch 44 at this time is input to the ECU 76, the ECU 76 sends the forward drive signal to the driver 72. Output for. The driver 72 to which the forward drive signal is input drives the motor 70 to rotate forward for a predetermined time.

  When the motor 70 is driven to rotate forward and the output shaft 78 is rotated forward, the gears 84 to 90 constituting the gear train 82 transmit to the outer ring 94 of the clutch 92 while reducing the rotational force based on the forward drive force of the motor 70. Then, the outer ring 94 is rotated in the pull-out direction. However, since the clutch 92 does not transmit the rotation of the outer peripheral ring 94 in the pull-out direction to the adapter, even if a rotation force in the pull-out direction based on the normal rotation driving force of the motor 70 is applied to the outer peripheral ring 94, The forward rotation driving force of the motor 70 is not transmitted.

  On the other hand, as described above, when the motor 70 is driven to rotate forward and the output shaft 78 rotates forward, the gears 84 to 90 transmit the rotation of the output shaft 78 to the gear 96 while decelerating and rotate the gear 96. When the gear 96 rotates in this manner and the shaft 98 rotates, the pawl 100 swings and presses the contact portion 108 of the cam 104. The contact portion 108 pressed by the pawl 100 rotates against the urging force of the compression coil spring 112, and the engagement claw 110 of the cam 104 approaches the ratchet teeth of the ratchet wheel 58 by the rotation of the cam 104. Mesh.

  In a state where the engaging claw 110 meshes with the ratchet teeth of the ratchet wheel 58, the rotation of the ratchet wheel 58 in the winding direction is restricted.

  In this state, since the rotation of the cylindrical portion 64 in the winding direction is restricted, the inner end 68A of the spiral spring 68 is fixed in the winding direction. Therefore, even if the spiral spring 68 has been tightened so far, the second urging force is not transmitted to the spool 28 via the cylindrical portion 64 and the spiral spring 66. Therefore, only the first urging force of the spiral spring 66 acts on the spool 28.

  Here, considering that the resultant force of the first urging force and the second urging force is acting on the spool 28 in a state where the engaging claw 110 is not meshed with the ratchet teeth of the ratchet wheel 58, the first attachment In the state where only the urging force is applied, the urging force applied to the spool 28 in the winding direction is reduced. Thereby, the restraining force by the webbing belt 30 can be weakened in a state where the occupant wears the webbing belt 30, and the occupant can be prevented or effectively reduced from having a feeling of pressure.

  Next, when the buckle switch 44 detects that the tongue plate 38 has been removed from the buckle device 42, such as when the occupant gets off, and the signal output from the buckle switch 44 at this time is input to the ECU 76, the ECU 76 A reverse drive signal is output to the driver 72. The driver 72 to which the reverse drive signal is input drives the motor 70 to rotate reversely for a predetermined time.

  When the motor 70 is driven to rotate reversely and the output shaft 78 rotates reversely, the gears 84 to 90 transmit the rotation of the output shaft 78 to the gear 96 while decelerating, and rotate the gear 96. When the gear 96 rotates in this way and the shaft 98 rotates, the pawl 100 swings away from the case 54. When the pawl 100 swings in this manner, the pressing force applied to the contact portion 108 of the cam 104 by the pawl 100 is released.

  The cam 104 from which the application of the pressing force from the pawl 100 is released is rotated by the urging force of the compression coil spring 112 applied to the contact portion 108. By the rotation of the cam 104, the engaging claw 110 of the cam 104 is separated from the ratchet teeth of the ratchet wheel 58, and the meshing state is released. As described above, the engagement state between the engagement claw 110 and the ratchet teeth of the ratchet wheel 58 is released, so that the rotation restriction of the ratchet wheel 58 in the winding direction by the engagement claw 110 is released.

  Accordingly, the rotation restriction of the cylindrical portion 64 is released, and the fixing of the inner end 68A of the spiral spring 68 in the winding direction is released. Thus, until now, only the first urging force of the spiral spring 66 has acted on the spool 28, but the second urging force of the spiral spring 68 urges the cylindrical portion 64 in the winding direction. The resultant force of the first urging force and the second urging force is transmitted to the spool 28.

  As described above, in this state, since the tongue plate 38 is removed from the buckle device 42, the spool 28 to which the resultant force of the first urging force and the second urging force is transmitted is only the first urging force. The webbing belt 30 is quickly wound around and stored in the spool 28 by the rotation force that is stronger than the rotation force of the roller.

  Further, when the motor 70 is driven reversely and the output shaft 78 is rotated reversely as described above, the gears 84 to 90 constituting the gear train 82 reduce the rotational force based on the reverse drive force of the motor 70 and the outer peripheral wheel of the clutch 92. 94 to rotate the outer ring 94 in the winding direction. When the outer peripheral ring 94 rotates, the clutch 92 swings while the pawl provided inside the outer peripheral ring 94 rotates in the winding direction together with the outer peripheral ring 94, and engages with an adapter inside the outer peripheral ring 94. The outer ring 94 and the adapter, and thus the spool 28 are mechanically connected.

  Thereby, the rotational force in the winding direction applied to the outer peripheral ring 94 is transmitted to the spool 28, and the spool 28 has a resultant force of the first urging force and the second urging force of the spiral springs 66, 68, as well as the motor. A rotational force in the winding direction based on the driving force of 70 is applied. Therefore, the spool 28 can be quickly rotated in the winding direction by this, and the webbing belt 30 can be quickly wound up.

  By the way, the seat belt device 10 has a configuration in which the cam 104 is rotated by swinging the pawl 100 by the driving force of the motor 70 for applying the rotational force in the winding direction to the spool 28. For this reason, a special device such as a solenoid for restricting the rotation of the ratchet wheel 58 becomes unnecessary. Thereby, the structure of the tension reducer 52 can be simplified, and the tension reducer 52 can be reduced in size and weight.

  When a solenoid for the tension reducer 52 is provided separately from the motor 70, the drive timing of the motor 70 and the energization (excitation) timing of the solenoid, etc. must be adjusted. Control becomes complicated. However, in the present seat belt device 10, since only the control of the motor 70 is required, the control by the ECU 76 is simplified.

  In the seat belt device 10, the gear 96 is engaged with the gear 90 as described above, and the rotation of the output shaft 78 is decelerated to rotate the gear 96. Of course, the gear 96 may be meshed with the gear 80 provided on the output shaft 78, but in this case, the rotation amount of the gear 96 with respect to the swing amount of the pawl 100 required for pressing and releasing of the cam 104. In many cases, the rotation amount of the shaft 98 is too large.

  In view of this, in the seat belt device 10, the output shaft 78 is preliminarily engaged with the gear 96 in the middle of the gear train 82 for decelerating the rotation of the output shaft 78 and transmitting it to the outer peripheral wheel 94 of the clutch 92. Can be sufficiently slowed down and transmitted to the gear 96. This eliminates the need for special reduction means for decelerating and transmitting the rotation of the output shaft 78 to the pawl 100, simplifying the configuration and reducing the cost.

  In the present embodiment, the ECU 76 and the driver 72 are set so as to drive the motor 70 in the reverse direction when the tongue plate 38 is removed from the buckle device 42. However, the conditions for driving the motor 70 in the reverse direction are not limited to the case where the tongue plate 38 is removed from the buckle device 42.

  For example, the vehicle 14 is provided with forward monitoring means for emitting forward monitoring signals such as infrared rays, lasers or radio waves to the front side of the vehicle, and for receiving forward monitoring signals reflected by obstacles ahead of the vehicle or other preceding vehicles. Based on the forward monitoring signal, the motor 70 may be driven in the reverse direction when the distance to the obstacle ahead or another vehicle is less than a predetermined distance.

  In such a configuration, the spool 28 can be quickly rotated in the winding direction by the reverse driving force of the motor 70 and the resultant force of the first urging force and the second urging force of the spiral springs 66 and 68. Therefore, slack that is a slight slack (slack) of the webbing belt 30 can be quickly eliminated, and the occupant's body can be reliably restrained by the webbing belt 30 having a strong restraining force during normal running.

  Further, in the present embodiment, the engagement claw 110 of the cam 104 is engaged with the ratchet wheel 58 to restrict the rotation of the ratchet wheel 58, thereby blocking transmission of the second urging force of the spiral spring 68 to the spool 28. Although the tension reducer 52 having a structure that substantially weakens the binding force of the webbing belt 30 is applied, the structure of the tension reducer is not limited to such a structure.

  For example, when the tongue plate 38 is held by the buckle device 42, an urging member having an urging force opposite to the urging direction of the urging force of the spiral spring 66 resists the urging force of the spiral spring 66. Thus, a tension reducer having a structure in which at least a part of the urging force of the spiral spring 66 is canceled and thereby the binding force of the webbing belt 30 is substantially weakened may be applied.

  Further, in the present embodiment, the shaft 98 and the pawl 100 are integrally connected. However, the shaft 98 and the pawl 100 may be mechanically connected by the clutch member, and the mechanical connection between the shaft 98 and the pawl 100 may be released. An example of a structure in which the shaft 98 and the pawl 100 are mechanically connected by such a clutch member will be described with reference to FIGS.

  As shown in FIGS. 7 and 8, in this modification, a cylindrical tube portion 122 is formed at the base portion of the pawl 100, and a circular hole 124 having an inner diameter size substantially equal to the inner diameter size of the tube portion 122 is formed in the tube portion. It is formed at the base of the pawl 100 coaxially with respect to 122. The inner diameter dimension of the cylindrical portion 122 and the circular hole 124 is slightly larger than the outer diameter dimension of the shaft 98, and the shaft 98 penetrates the cylindrical portion 122 and the circular hole 124 so that the pawl 100 can be rotated around the shaft 98. Support.

  Further, the pawl 100 is formed with a circular hole 126 coaxially with the circular hole 124. The circular hole 126 is formed so that its inner diameter is sufficiently larger than that of the circular hole 124. The depth dimension of the circular hole 126 is smaller than the thickness dimension of the pawl 100, and one end of the circular hole 126 opens at the end face on the opposite side of the end face of the pawl 100 where the cylindrical portion 122 is provided.

  Further, an engagement convex portion 128 is formed so as to protrude from a part of the inner periphery of the circular hole 126 toward the radially inner side of the circular hole 126. Further, a clutch spring 130 that constitutes a restricting means as a connecting member is disposed inside the circular hole 126.

  The clutch spring 130 includes a main body 132 having a substantially C shape (that is, a ring shape in which a part thereof is cut) whose inner diameter is substantially equal to the outer diameter of the shaft 98. An engaging piece 134 is formed to bend from one end of the main body 132 toward the radially outward side of the main body 132, and from the other end of the main body 132 to the radially outward side of the main body 132. The engagement piece 136 is formed by bending.

  In a modification of such a structure, when the gear 96 rotates and the shaft 98 rotates, the friction between the outer periphery of the shaft 98 and the inner periphery of the main body 132 of the clutch spring 130 causes the clutch spring 130 to move to the shaft 98. Follow and rotate. When the engagement piece 134 or the engagement piece 136 contacts the engagement convex portion 128, the clutch spring 130 rotated following the shaft 98 presses the engagement convex portion 128 in the rotation direction, and the pawl 100 is moved to the shaft. Rotate in the same direction as 98. Thereby, the pawl 100 can be rotated in a direction in which the pawl 100 is in contact with or separated from the case 54.

  Here, as described above, the pawl 100 presses the contact portion 108 of the cam 104 and rotates the cam 104 to mesh the engagement claw 110 with the ratchet teeth of the ratchet wheel 58. In this way, in a state where the engaging claw 110 is engaged with the ratchet teeth of the ratchet wheel 58, the cam 104 can basically not rotate any further. Therefore, when the pawl 100 further rotates in the direction in which the contact portion 108 is pressed in this state, the contact portion 108 restricts the rotation of the pawl 100.

  When the shaft 98 attempts to rotate the pawl 100 via the clutch spring 130 in this restricted state, the pressing reaction force from the contact portion 108 causes the outer peripheral portion of the shaft 98 and the inner peripheral portion of the main body 132 of the clutch spring 130. Overcome the friction that occurs during As a result, slip occurs between the main body 132 of the clutch spring 130 and the shaft 98, and transmission of rotational force from the shaft 98 to the pawl 100 is interrupted. Due to the slipping, the pawl 100 does not rotate even when the shaft 98 rotates.

  Therefore, after the engaging claw 110 meshes with the ratchet teeth of the ratchet wheel 58 in this way, the transmission of the rotational force from the shaft 98 to the pawl 100 can be interrupted by the pressing reaction force from the contact portion 108, so that excessive pressing force Can be prevented from being applied to the cam 104.

  Further, since it is possible to prevent an excessive pressing force from being applied to the cam 104 as described above, the amount of rotation of the shaft 98 when the engaging claw 110 is engaged with the ratchet teeth of the ratchet wheel 58 must be set strictly. Therefore, the reduction ratio from the gear 80 to the gear 96 need not be set strictly. Thereby, the design of the gear train 82 and the gear 96 is facilitated, and the cost can be reduced.

It is a front sectional view showing the outline of the whole composition of the webbing retractor which constitutes the seatbelt device concerning one embodiment of the present invention. 1 is a side view showing an outline of the overall configuration of a seat belt device according to an embodiment of the present invention. It is a disassembled perspective view which shows the structure of a deceleration means and a limiting means. It is a disassembled perspective view which shows the structure of a tension reducer. It is a schematic side view which shows the state which the restriction member (pawl) has not controlled the displacement of a displacement member (ratchet wheel). It is a schematic side view which shows the state which the restriction member (pawl) has controlled the displacement of a displacement member (ratchet wheel). It is a perspective view which shows the modification of a limiting means. It is a front view which shows the modification of a restriction | limiting means.

Explanation of symbols

10 seat belt device 28 spool 30 webbing belt 38 tongue plate 42 buckle device 44 buckle switch (tang detection means)
58 Ratchet wheel (displacement member)
66 Spiral spring (biasing means)
70 Motor (drive means)
76 ECU (control means)
78 Output shaft 92 Clutch (clutch means)
98 Shaft (Rotating body, Limiting means)
100 pawl (restricting member, limiting means)
130 Clutch spring (connection member, limiting means)

Claims (4)

A long belt-like webbing belt that is wound around the spool by the rotation of the spool in the winding direction, whose longitudinal base end is locked to the spool and is around the axis, is attached to the body of an occupant seated in the seat As a result, the urging force of the urging means that restrains the occupant's body and is directly or indirectly connected to the spool is the amount of rotation of the spool in the pull-out direction opposite to the winding direction. A seat belt device configured to include a webbing take-up device that urges the spool in the take-up direction by increasing in accordance with an increase in
A displacement member that displaces in conjunction with the rotation of the spool, and cancels at least a part of the urging force applied to the spool by the urging means by restricting the displacement of the displacement member or releasing the restriction; A tension reducer that applies an external force in the same direction as the biasing force to the spool together with the biasing force of the biasing means;
An output shaft that rotates by a driving force is provided, and the output shaft is rotated by the driving force in a state where the output shaft is connected to the spool, whereby a rotational force in a winding direction or a drawing direction is applied to the spool. Driving means for
The drive unit is coupled to the output shaft, and is engaged with the displacement member by forward rotation of the output shaft in accordance with the normal rotation driving force of the drive unit to limit the displacement of the displacement member. Limiting means for releasing the engagement by reversing the output shaft by a reverse driving force;
A seat belt device comprising: A tongue plate provided in the middle in the longitudinal direction of the webbing belt;
A buckle device that is attached to the seat or in the vicinity of the seat so that the tongue plate can be engaged, and holds the tongue plate by engaging the tongue plate;
A tongue detecting means provided on the buckle device for detecting whether or not the tongue plate is engaged with the buckle device;
The reverse rotation of the output shaft is transmitted to the spool as rotation in the winding direction, and the output shaft and the spool are disconnected in conjunction with the normal rotation of the output shaft, and the output to the spool Clutch means for interrupting transmission of rotation of the shaft;
When the tongue plate is engaged with the buckle device, the drive means is driven to rotate forward based on a signal output from the tongue detection means, and the tongue plate is disengaged from the buckle device. Control means for reversely driving the driving means based on a signal output from the tongue detecting means;
With
The restriction member is engaged with the displacement member to cancel at least a part of the urging force of the urging means,
The seat belt device according to claim 1. It is interposed between the output shaft and the spool, and is provided directly or indirectly on a reduction gear that decelerates the rotation of the output shaft and transmits it to the spool. The rotation of the reduction gear makes contact with the displacement member. The limiting member is a limiting member that moves away and engages with the displacement member and releases the engagement.
The seat belt device according to claim 1 or 2, characterized by the above. A rotating body connected directly or indirectly to the output shaft and rotating around its own axis in conjunction with rotation of the output shaft;
A limiting member that is attached to the rotating body, moves toward and away from the displacement member by rotating around the axis of the rotating body, and engages and disengages the displacement member by the contact and separation movement;
The restricting member is connected to the rotating body, and the restricting member is rotated integrally with the rotating body, and the rotation direction of the restricting member when the restricting member is engaged with the displacement member is opposite to that of the rotating member. A connecting member that releases the connection between the limiting member and the rotating body and relatively rotates the rotating body with respect to the limiting member when an external force of a predetermined magnitude or more acts on the limiting member;
Including the limiting means,
The seatbelt device according to any one of claims 1 to 3, wherein the seatbelt device is provided.

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