JP2005329826A - Clutch mechanism and webbing take-up device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a clutch mechanism capable of certainly transferring/intercepting rotational force, and a webbing take-up device capable of certainly releasing mechanical connection between a spool and a driving means when the driving means stops. <P>SOLUTION: A tip end 134A of a pawl 130 abuts on an abutting surface 196 of outer teeth 194 to press, thereby rotating a cylindrical portion 192. At that time, if rotational force added on the abutting surface is less than a predetermined number of rotations, an adapter body 182 rotates following the cylindrical portion 192 without being able to resist to energizing force of a torsion coil spring 198 even if the cylindrical portion rotates. In this state, the pawl can rotate in a pulling-out direction. However, the rotational force added on the abutting surface is not less than the predetermined number of rotations, the cylindrical portion rotates against the energizing force of the torsion coil spring. Therefore, the tip end of the pawl is engaged with the outer teeth 184 of the adapter body, so that rotations of the pawl in the pulling-out direction is regulated by an interference surface 188 of the outer teeth. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a clutch mechanism that transmits or interrupts a driving force of a motor or the like and a seat belt device that restrains 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 carrier gear is rotated by the revolution of the planetary 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 to rotate the internal gear, and the planetary gear itself is 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 2002-308048 A

  By the way, in the webbing take-up device disclosed in Patent Document 1, the rotation of the internal gear is restricted by bringing the locking lever closer to the ratchet gear of the internal gear and engaging with the ratchet gear, and around the sun gear of the planetary gear. It is a configuration that enables orbital revolution.

  In such a configuration, there is a possibility that the teeth of the ratchet gear to be further rotated come into pressure contact with the locking lever with excessive pressure in a state where the rotation is restricted by the locking lever. In such a case, an external force acting in the direction in which the locking lever is separated from the ratchet gear due to the dynamic frictional resistance between the locking lever and the ratchet gear based on the pressure at the time of pressure contact (that is, in Patent Document 1, the lever spring is attached). If the force is greater than the force, the engagement between the lever spring and the ratchet gear is not released (ie, the clutch cannot be disengaged). As a result, for example, when the webbing belt is pulled out, the rotation of the spool is restricted by the motor. The webbing belt may not be pulled out.

  In view of the above facts, the present invention provides a webbing that can reliably release the mechanical connection between the spool and the drive means when the clutch mechanism and the drive means that can reliably transmit and shut off the rotational force are stopped. The purpose is to obtain a winding device.

  The clutch mechanism according to the first aspect of the present invention includes a driving-side rotating body that rotates when a rotational force is input, and a driven-side rotating body that rotates by transmitting the rotation of the driving-side rotating body. In addition to being displaced in a predetermined connecting direction in conjunction with the rotation of the driving side rotating body, the rotation of the driving side rotating body is transmitted to the driven side rotating body by the displacement in the connecting direction, and the driven side rotating body And a clutch member configured to rotate the motor-side rotating member, and when the driving-side rotating body rotates at a rotational speed of at least one of a predetermined value and a lower value, The displacement of the clutch member in the opposite release direction is restricted to maintain the connection state between the driving side rotating body and the driven side rotating body, and at the other rotation speed of the predetermined value or more and less than When the driving side rotating body is rotating , The clutch member is not subject to the regulations, it is characterized in that.

  According to the clutch mechanism of the first aspect of the present invention, when the driving side rotating body rotates, the clutch member is displaced in the connecting direction in conjunction with the rotation. In the displacement state of the clutch member in the connecting direction, the rotation of the driving side rotating body is transmitted to the driven side rotating body via the clutch member, whereby the driven side rotating body rotates.

  Further, the clutch member displaced in the coupling direction is displaced in the release direction opposite to the coupling direction, so that the mechanical coupling state between the driving side rotating body and the driven side rotating body via the clutch member as described above is achieved. Canceled.

  As described above, in the clutch mechanism according to the present invention, since the clutch member is displaced in the coupling direction in conjunction with the rotation of the driving side rotating body, basically, if the driving side rotating body is not rotating, the driving side rotation is performed. The body and the driven rotating body are not connected.

  Therefore, in the clutch mechanism according to the present invention, the rotation of the driving-side rotator can be transmitted to the driven-side rotator to rotate the driven-side rotator, but temporarily, the driven-side rotator is separated from the driving-side rotator. Even if an external force is applied and the driven side rotating body rotates, the rotation of the driven side rotating body is not applied to the driving side rotating body and the driving side rotating body is not rotated.

  By the way, in the clutch mechanism according to the present invention, basically, when the driving side rotating body rotates, the clutch member is displaced in the connecting direction and transmits the rotation of the driving side rotating body to the driven side rotating body. In addition, when the driving side rotating body is rotating at a rotational speed of any one of the predetermined value or more and less than the predetermined value, the displacement of the clutch member in the releasing direction is restricted, so that the driving side rotating body and the driven side rotation are controlled. The connection with the body is maintained. Therefore, in this state, the rotation of the driving side rotating body is reliably transmitted to the driven side rotating body, and the driven side rotating body can be rotated.

  On the other hand, when the driving-side rotating body is rotating at the other rotation speed that is greater than or less than a predetermined value, the clutch is used when the driving-side rotating body is rotating at either rotation speed. The clutch member does not receive the displacement restriction in the release direction received by the member.

  Therefore, basically, the driven-side rotator and the driving-side rotator are connected by the clutch member, and the driving-side rotator can be rotated in the winding direction by the rotational force of the driven-side rotator. However, even in this state, the clutch member can be displaced in the releasing direction. For this reason, for example, when another external force is applied to the driven side rotating body while the driving side rotating body is rotating, the clutch member is displaced in the release direction, so that the driving side rotating body and the driven side rotating body are Thus, the driven-side rotator can be rotated without being influenced by the rotation, and the driven-side rotator can be rotated.

  The clutch mechanism according to a second aspect of the present invention is the clutch mechanism according to the first aspect, wherein the clutch mechanism is displaced in the coupling direction along a rotation direction when the rotation is received by the rotation of the driving side rotating body. A first rotating body that has an abutting portion with which the clutch member abuts, and rotates when the abutting portion is pressed by the clutch portion, and is provided so as to be relatively rotatable coaxially with the first rotating body. In addition, the clutch member is engaged by the relative rotation of the first rotating body by a predetermined angle by the pressing force from the clutch member in a state where the clutch member is in contact with the contact portion, and the clutch member is engaged in the engaged state. A second rotating body having an interference portion that rotates while being pressed and interferes with the clutch member from the release direction side in the engaged state and restricts displacement of the clutch member toward the release direction side, The first rotating body and the The two rotating bodies are connected so as to be relatively rotatable by a predetermined angle, and the rotation of either one of the first rotating body and the second rotating body is transmitted to the rotating body of either one of the first rotating body and the second rotating body. A connecting member that rotates the body, and the first rotating body is urged against the second rotating body in the direction opposite to the rotation direction when receiving the rotational force from the driving side rotating body, and the engagement is possible. And an urging means for displacing the abutable position in the urging direction side from the position by the predetermined angle. The driven rotator is configured to output the rotation of the first rotator or the second rotator. And the first rotating body rotates relative to the second rotating body against the biasing force of the biasing means when the driving-side rotating body rotates at the predetermined rotational speed or more. It is characterized by that.

  In the clutch mechanism according to the second aspect of the present invention, when the driving side rotating body rotates and the clutch member is displaced in the connecting direction, the clutch member comes into contact with the contact portion of the first rotating body. The rotational force of the side rotating body is transmitted to the first rotating body via the clutch member, and the first rotating body rotates. If the rotation of the first rotating body is output, the rotation of the first rotating body is directly output as described above.

  The first rotating body is connected to the second rotating body so as to be relatively rotatable by a predetermined angle. However, the pressing force from the clutch member (that is, the driving force) is applied to the second rotating body by the biasing force of the biasing means. The rotational force is applied in the direction opposite to the rotational direction when the rotational force from the side rotating body is applied. For this reason, if the rotation speed of the driving side rotating body is less than a predetermined value, when the first rotating body rotates, the second rotating body rotates following the first rotating body by the biasing force of the biasing means. Therefore, if the rotation of the second rotating body is output, the second rotating body rotates following the first rotating body, so that the rotation of the first rotating body is connected to the connecting member, the biasing means, and the first rotating body. It is output indirectly via the two-rotor.

  Here, as described above, if the rotational speed of the driving-side rotator is less than the predetermined value, the second rotator follows and rotates when the clutch member presses the contact portion to rotate the first rotator. However, the first rotating body does not rotate relative to the second rotating body by a predetermined angle. Therefore, in this case, the clutch member that is in contact with the contact portion is not engaged with the second rotating body, and basically the clutch member is released only in contact with the contact portion. Not subject to displacement restrictions.

For this reason, for example, when another external force is applied to the driven side rotating body while the driving side rotating body is rotating, the clutch member is displaced in the release direction, so that the driving side rotating body and the driven side rotating body are And the first rotating body and the second rotating body (that is, the driven rotating body) are rotated in the acting direction of another external force without being influenced by the rotation. On the other hand, if the rotational speed of the driving side rotating body is equal to or greater than a predetermined value, when the clutch member presses the contact portion, the first rotating body not only simply rotates but also resists the biasing force of the biasing means. Thus, it also rotates relative to the second rotating body. Accordingly, when the first rotating body rotates by a predetermined angle with respect to the second rotating body, the clutch member that is in contact with the contact portion is engaged with the second rotating body. As described above, when the clutch member is engaged with the second rotating body, the interference portion of the second rotating body interferes with the clutch member from the release direction side. Due to the interference of the interference portion, the displacement of the clutch member in the release direction is restricted. For this reason, the rotation of the driving side rotating body is reliably transmitted to the first rotating body and the second rotating body.

  The webbing take-up device according to the third aspect of the present invention is such that a longitudinal base end side of a long belt-like webbing belt that restrains the occupant's body in a mounted state with respect to the body of the vehicle occupant is locked to a spool, A webbing take-up device for taking up and storing the webbing belt from the base end side by rotating the spool in one winding direction around the shaft, and a driving means for rotating the output shaft by its own driving force; A clutch member that displaces in a predetermined coupling direction in conjunction with rotation of the output shaft, and the clutch member is displaced in the coupling direction to transmit the rotation of the output shaft to the spool and When the output shaft rotates in the winding direction and at any one of the rotation speeds greater than or less than a predetermined value, the displacement of the clutch member in the release direction is regulated. The clutch member is not subjected to the restriction when the output shaft and the spool are kept connected and the output shaft is rotated at the other rotational speed of a predetermined value or more. And a clutch means.

  According to the webbing take-up device according to the third aspect of the present invention, when the occupant sits on the seat of the vehicle and pulls the long belt-like webbing belt toward the front end side, the state is wound on the spool. While the webbing belt stored in is pulled out, the spool rotates in the pull-out direction. When the webbing belt pulled out in this way is hung around the occupant's body and, for example, a tongue plate provided on the webbing belt is engaged with the buckle device, the webbing belt is attached to the occupant's body.

  The spool is connected to the clutch means. The clutch means is connected to the output shaft of the drive means. When the drive means is operated and the output shaft rotates, the clutch member of the clutch means is displaced in the connection direction. When the clutch member is displaced in the connecting direction in this way, the spool and the output shaft are connected via the clutch means, and the rotational force of the output shaft is transmitted to the spool via the clutch means, so that the spool is Rotates in the opposite winding direction.

  Thus, the webbing belt is wound around the spool from the base end side by rotating the spool in the winding direction by the driving force of the driving means. Therefore, for example, if the tank plate is removed from the buckle device in this state and the mounted state is released, the webbing belt is wound around the spool from the proximal end side and stored.

  On the other hand, for example, if the driving means operates and the spool rotates in the winding direction while maintaining the above mounted state, the webbing belt is wound around the spool, so that the webbing belt in the mounted state is Slight loosening (so-called “slack”) is eliminated, and the webbing belt restrains the occupant's body with a greater force than before (ie, the restraining force of the occupant's body by the webbing belt increases).

  By the way, in the webbing take-up device according to the present invention, basically, when the output shaft is rotated by the driving force of the driving means, the clutch member is displaced in a predetermined connecting direction to transmit the rotation of the output shaft to the spool. In addition, when the output shaft rotates at any one of the rotation speeds greater than or less than the predetermined value, the displacement of the clutch member in the release direction opposite to the coupling direction is restricted. For this reason, the connection between the output shaft and the spool is maintained. Therefore, in this state, the rotation of the output shaft is reliably transmitted to the spool, and the spool can be rotated in the winding direction.

  On the other hand, when the output shaft rotates at the other rotation speed that is greater than or less than a predetermined value, the release that the clutch member receives when the output shaft rotates at either rotation speed. The clutch member is not subject to displacement restriction in the direction.

  Therefore, the spool and the output shaft are basically connected by the clutch member, and the output shaft can be rotated in the winding direction by the rotational force of the spool. However, even in this state, the clutch member can be displaced in the releasing direction. For this reason, for example, when a rotational force in the pulling direction is applied to the spool during the rotation of the output shaft, the clutch member is displaced in the release direction, so that the mechanical connection between the output shaft and the spool is released, Even when the output shaft is rotating (that is, when the driving means is operating), the spool can be rotated in the winding direction (that is, the webbing belt can be pulled out).

  A webbing take-up device according to a fourth aspect of the present invention is the webbing retractor according to the third aspect of the present invention, wherein the driving means is operated when the distance from the vehicle to the obstacle is equal to or less than a predetermined value. The output shaft is rotated at any one of the rotation speeds, and the driving means is operated when the mounted state is released, and the output shaft is rotated at any one of the rotation speeds. It is characterized by that.

  According to the webbing retractor of the present invention as set forth in claim 4, for example, when there is an obstacle on the front side of the traveling vehicle and the distance to the obstacle becomes a predetermined value or less, the control means The drive means is activated. The driving means operated in this state rotates the output shaft at any one of the rotational speeds greater than or less than a predetermined value. For this reason, when the clutch member of the clutch means is displaced in the coupling direction and the output shaft and the spool are coupled, the displacement of the clutch member in the releasing direction is restricted.

  Therefore, in this state, transmission of the rotational force from the output shaft to the spool via the clutch member is not inadvertently interrupted, and the spool is reliably rotated in the winding direction to increase the restraining force by the webbing belt. , Can securely hold the occupant's body.

  On the other hand, when the occupant gets off the vehicle, when the webbing belt attached to the occupant's body is removed, for example, when the tongue plate provided on the webbing belt is removed from the buckle device, the control means Actuates the drive means. Thus, the spool rotates in the winding direction, so that the webbing belt is wound and stored in the spool from the base end side.

  In a general webbing take-up device, the spool is rotated in the take-up direction by a biasing force of a biasing member such as a spiral spring, and the webbing belt is stored. However, in the webbing take-up device according to the present invention, as described above. Since the webbing belt is wound by the driving force of the driving means, the biasing member such as a spiral spring can be eliminated or the biasing force of the biasing member can be reduced. Thereby, when the webbing belt is pulled out and attached, the feeling of pressure received by the occupant from the webbing belt based on the biasing force of the biasing member such as a spiral spring can be reduced or eliminated.

  Further, the driving means that is activated when the webbing belt attached to the occupant's body is removed rotates the output shaft at the other rotational speed that is greater than or less than a predetermined value. For this reason, even if the clutch member of the clutch means is displaced in the connecting direction and the output shaft and the spool are connected, the displacement of the clutch member in the releasing direction is not restricted.

  Therefore, even when the webbing belt is wound and stored, even if the webbing belt is pulled, for example, the driving means stops and the clutch member is displaced in the release direction, so that the output shaft and the spool The mechanical connection of can be reliably released.

  As described above, the clutch mechanism according to the present invention can reliably transmit and block the rotational force. Moreover, the webbing take-up device according to the present invention can reliably release the mechanical connection between the spool and the driving means when the driving means stops.

<Configuration of the present embodiment>
FIG. 1 is a front sectional view showing an outline of the entire configuration of a webbing take-up device 10 according to a first embodiment of the present invention.

  As shown in this figure, the webbing take-up device 10 includes a frame 12. The frame 12 includes a substantially plate-like back plate 14. The back plate 14 is fixed to the vehicle body by fastening means (not shown) such as bolts, so that the webbing take-up device 10 is attached to the vehicle body. ing. A pair of leg plates 16 and 18 extend in parallel from both ends of the back plate 14 in the width direction, and a spool 20 manufactured by die casting or the like is rotatably disposed between the leg plates 16 and 18.

  The spool 20 includes a substantially cylindrical spool body 22 and a pair of flange portions 24 and 26 formed in a substantially disk shape at both ends of the spool body 22, respectively. Yes.

  The spool main body 22 has a base end portion of a webbing belt 28 formed in a long band shape fixed between the flange portions 24 and 26. When the spool 20 is rotated to one side around its axis, the webbing belt 28 is The spool body 22 is wound around the outer periphery of the spool body 22 from the base end side. When the webbing belt 28 is pulled from the front end side, the webbing belt 28 wound around the outer periphery of the spool body 22 is pulled out, and accordingly, the rotation direction when the webbing belt 28 is wound (hereinafter, this direction). Is referred to as “winding direction” for the sake of convenience, and the spool 20 rotates (hereinafter, the rotation direction of the spool 20 when the webbing belt 28 is pulled out is referred to as “drawing direction” for convenience).

  The one end side of the spool 20 on the side opposite to the flange portion 26 of the flange portion 24 penetrates a circular hole 30 formed in the leg plate 16 substantially coaxially and protrudes to the outside of the frame 12. A case 32 is disposed outside the frame 12 on the leg plate 16 side. The case 32 is disposed facing the leg plate 16 along the axial direction of the spool 20 and is fixed to the leg plate 16. The case 32 is opened toward the leg plate 16 as a whole, and one end side of the spool 20 penetrating the circular hole 30 enters the inside of the case 32 and is rotatably supported by the case 32.

  Further, a spiral spring 34 is disposed inside the case 32. The spiral spring 34 has an end on the outer side in the spiral direction locked with the case 32, and an end on the inner side in the spiral direction locked with the spool 20. When the spool 20 is rotated in the pull-out direction from a neutral state where no special load is applied, the spiral spring 34 generates a biasing force in the winding direction and biases the spool 20 in the winding direction. Therefore, basically, when the tensile force applied to the webbing belt 28 to be pulled out from the spool 20 is released, the urging force of the spiral spring 34 rotates the spool 20 in the winding direction so that the webbing belt 28 is wound around the spool 20. It has a structure that can be taken.

  On the other hand, the other end side of the spool 20 on the side opposite to the flange portion 24 of the flange portion 26 penetrates the ratchet hole 36 of the internal tooth formed in the leg plate 18 substantially coaxially and protrudes to the outside of the frame 12. . A lock mechanism 38 is disposed outside the frame 12 on the leg plate 18 side. The lock mechanism 38 includes a case 40. The case 40 is disposed to face the leg plate 18 along the axial direction of the spool 20 and is fixed to the leg plate 18.

  A ratchet gear 42 constituting the lock mechanism 38 is accommodated inside the case 40 so as to be coaxial with the spool 20 and relatively rotatable. The ratchet gear 42 has a shallow cylindrical shape opened on the opposite side to the axial leg plate 18, and ratchet teeth are formed on the outer periphery thereof.

  A lock base 44 is accommodated inside the ratchet gear 42. The lock base 44 is provided coaxially and integrally with the spool 20, and thus rotates integrally with the spool 20 by the rotation of the spool 20. The lock base 44 is provided with a biasing means such as a compression coil spring (not shown).

  A part of the urging means is engaged with the ratchet gear 42 described above. When the lock base 44 rotates, the urging means rotates together with the lock base 44 and applies an urging force along the rotation direction to the ratchet gear 42. To do. Therefore, the ratchet gear 42 is originally rotatable relative to the spool 20, but the ratchet gear 42 is spooled by the biasing force applied from the biasing means when the lock base 44 rotates integrally with the spool 20. It is the structure which rotates following 20 rotation.

  On the other hand, the lock plate 46 is supported by the lock base 44 inside the ratchet hole 36 described above. The lock plate 46 can move toward and away from the inner teeth of the ratchet hole 36 while being supported by the lock base 44. The lock plate 46 is engaged with the ratchet gear 42 described above. When the ratchet gear 42 rotates relative to the lock base 44 in the winding direction described above, the ratchet hole 36 is interlocked with this rotation. The inner teeth of the ratchet hole 36 are engaged with each other.

  Further, a lower portion in the radial direction of the ratchet gear 42 in the case 40 is a sensor holder 47, and a sensor frame 48 is assembled inside thereof. The sensor frame 48 has a mounting portion (not shown) that is curved with a predetermined curvature and opens upward, and the sensor ball 50 is mounted on the mounting portion. Further, an engagement plate 52 is provided above the sensor ball 50.

  The engagement plate 52 is attached to the sensor frame 48 so as to be pivotable up and down. When the sensor ball 50 rolls on the mounting portion described above and is displaced upward, it presses against the sensor ball 50 from above. Rotate.

  Further, an engagement claw 54 is formed on the engagement plate 52. The engagement claw 54 has its tip opposed to the ratchet teeth of the ratchet gear 42. When the engagement plate 52 rotates upward, the engagement claw 54 meshes with the ratchet teeth of the ratchet gear 42, and the ratchet gear 42 rotates. It has a configuration to regulate.

  On the other hand, a motor 72 as drive means is disposed below the spool 20 and between the leg plate 16 and the leg plate 18. A gear 64 is coaxially and integrally provided on the output shaft 73 of the motor 72.

  A gear 66 having a larger diameter than that of the gear 64 is disposed above the gear 64 in the radial direction. The gear 66 meshes with the gear 64 while being rotatably supported about an axis parallel to the spool 20 by the support plate 68 and the leg plate 16 provided between the leg plates 16 and 18. A gear 70 having a smaller diameter than the gear 66 is provided coaxially and integrally with the gear 66 on the side of the gear 66 in the axial direction.

  The motor 72 is electrically connected to the battery 76 via the driver 74. The driver 74 is connected to the ECU 78, and causes a current to flow through the motor 72 or cuts off the current based on a control signal from the ECU 78.

  The ECU 78 is electrically connected to the calculation unit 84 of the front monitoring device 82. The calculation unit 84 is connected to a front monitoring sensor 86 provided near the front end of the vehicle.

  The forward monitoring sensor 86 emits a monitoring signal such as infrared rays and radar substantially toward the front side of the vehicle, and includes other vehicles traveling in front of the vehicle and obstacles in front (hereinafter referred to as other vehicles traveling forward). The monitoring signal reflected by the obstacle) is received.

  The calculation unit 84 calculates the distance from the vehicle to the obstacle based on the time from when the monitoring signal is emitted from the front monitoring sensor 86 until it is reflected by the obstacle and received by the front monitoring sensor 86. The calculation result is input to the ECU 78. The ECU 78 outputs a control signal to the driver 74 based on the calculation result in the calculation unit 84.

  The ECU 78 is electrically connected to the buckle switch 88. The buckle switch 88 is provided, for example, in a buckle device (not shown) disposed on the opposite side of the webbing take-up device 10 via a vehicle seat.

  The buckle device can be inserted with a tongue plate (not shown) provided in the middle in the longitudinal direction of the webbing belt 28, and an occupant seated in the seat pulls out the webbing belt 28 to his body. When the tongue plate is inserted into the buckle device while the webbing belt 28 is wound around, the tongue plate is held by the buckle device. As a result, the webbing belt 28 is attached to the occupant's body (hereinafter, this state is simply referred to as “attached state”).

  The buckle switch 88 detects whether or not the tongue plate is inserted and held in the buckle device, and outputs an electric signal corresponding to the detection result to the ECU 78.

  On the other hand, as shown in FIG. 2, a clutch 90 as a clutch means or a clutch mechanism according to an embodiment of the present invention is provided on the side of the gear 70 in the radial direction.

  As shown in FIG. 2, the clutch 90 includes a base plate 92 as an intermediate rotating body. The base plate 92 is formed in a bottomed cylindrical shape (or a shallow basin shape) having a very short axial dimension in which a substantially ring-shaped peripheral wall 96 as an intermediate peripheral wall is formed along the outer peripheral portion of the disc-shaped base portion 94. ing. A thin disc-shaped cover 98 is attached to the opening end on one axial end side of the base plate 92, and the opening end of the base plate 92 is basically closed.

  Engagement recesses 100 are formed in the outer peripheral portion of the peripheral wall 96 at regular intervals along the circumferential direction. Further, an external gear 102 as a driving side rotating body is provided outside the peripheral wall 96. The external gear 102 is formed in a substantially ring shape having a sufficiently larger number of teeth than the gear 70, and is arranged coaxially with respect to the base plate 92.

  Further, the inner diameter of the external gear 102 is sufficiently larger than the outer diameter of the peripheral wall 96, and an annular gap is formed between the inner peripheral portion of the outer gear 102 and the outer peripheral portion of the peripheral wall 96. The plurality of torque limiters 104 are intermittently arranged in the circumferential direction in the annular gap.

  The torque limiter 104 is a thin plate-like metal piece having a spring property whose width is less than the axial dimension of the external gear 102, and can enter the engagement recess 100 at the center in the longitudinal direction. An engaging portion 106 is formed. Further, on both ends in the longitudinal direction of the torque limiter 104, engagement protrusions 108 that are bent so as to protrude in a direction substantially opposite to the protrusion direction of the engagement portion 106 are formed.

  An engagement recess 110 is formed in the inner peripheral portion of the external gear 102 corresponding to the engagement protrusion 108, and the engagement portion 106 is engaged with the engagement recess 108 in a state where the engagement protrusion 108 enters the engagement recess 110. By entering 100, the base plate 92 and the external gear 102 are substantially integrally connected via the torque limiter 104. As a result, when the external gear 102 attempts to rotate relative to the base plate 92 around the axis of the base plate 92, the torque limiter 104 naturally rotates together with the external gear 102.

  However, since each engagement portion 106 of the torque limiter 104 enters the engagement recess 100, when the engagement portion 106 tries to rotate along the circumferential direction of the peripheral wall 96, the engagement recess 100 becomes the engagement portion 106. Interfering and restricting the rotation of the engaging portion 106. Thereby, the relative rotation of the external gear 102 with respect to the base plate 92 is restricted, and basically the external gear 102 and the base plate 92 are integrally connected.

  However, as described above, since the torque limiter 104 is a metal piece having a spring property, the rotational force generated by the relative rotation of the external gear 102 with respect to the base plate 92 resists the spring force (biasing force) of the torque limiter 104. If the engagement portion 106 is large enough to be disengaged from the engagement recess 100, the interference with the engagement portion 106 by the engagement recess 100 is released, so that the external gear 102 is relative to the base plate 92. This is a configuration that allows rotation.

  On the other hand, an adapter 180 as a driven-side rotating body is disposed substantially coaxially with respect to the base plate 92 inside the above-described base plate 92.

  Here, FIG. 3 shows the configuration of the adapter 180 in an exploded perspective view. As shown in FIG. 3, the adapter 180 includes an adapter main body 182 as a second rotating body.

  The adapter main body 182 is generally formed in a cylindrical shape with a circular outer periphery, and is coaxially assembled with the spool 20 in a state in which the adapter main body 182 is prevented from rotating relative to the spool 20. In addition, an odd number of external teeth 186 are formed on the outer peripheral portion 184 of the adapter main body 182 at every predetermined angle.

  The surface of each external tooth 186 on the drawing direction side is an interference surface 188, and the angle formed by the interference surface 188 with respect to the tangential direction of the outer peripheral portion 184 at the boundary portion between the interference surface 188 and the outer peripheral portion 184 is an acute angle. It has become.

  Between the interference surface 188 and the outer peripheral portion 184, a front end 134A of a pawl 130 as a clutch member described later can enter, but the front end 134A enters between the interference surface 188 and the outer peripheral portion 184. Then, the interference surface 188 is positioned on the drawing direction side of the tip 134A.

  A shaft support 190 is formed coaxially from one axial end surface of the adapter body 182. The outer periphery of the shaft support 190 is circular, and a cylindrical portion 192 as a first rotating body is rotatably supported on the shaft support 190.

  The adapter 180 includes a cylindrical portion 192. The cylindrical portion 192 is formed in a cylindrical shape as a whole, and the same number of external teeth 194 as the external teeth 186 are formed on the outer peripheral portion at every predetermined angle.

  The surface of each external tooth 194 on the drawing direction side is a contact surface 196. When the tip 134A of the pawl 130 is in contact with the contact surface 196, the angle of the contact surface 196 is set so as to face the tip 134A in the tangential direction of the cylindrical portion 192 on the contact surface 196. ing.

  Furthermore, a torsion coil spring 198 as a connecting member and biasing means is provided on the shaft support 190 of the adapter main body 182. One end of the torsion coil spring 198 is locked to the adapter main body 182, and the other end is locked to the cylindrical portion 192. The adapter main body 182 rotates relative to the cylindrical portion 192 in the pull-out direction. As a result, the urging force increases, and the urging force urges the adapter body 182 in the winding direction with respect to the tubular portion 192.

  As shown in FIG. 2, the adapter 180 having the above configuration is rotatably supported by a circular hole 116 formed at the other end in the axial direction at the center of the base portion 94 (base plate 92). A cylindrical tube portion 114 formed in the adapter main body 182 is rotatably supported in a circular hole 116 formed in the cover 98.

  Between the adapter 180 and the base portion 94 of the base plate 92, a spacer 118 formed in a ring shape from a synthetic resin material is disposed. The spacer 118 is pivotally supported on the cylindrical portion 200 of the cylindrical portion 192.

  Further, a pair of bosses 124 are formed on the base portion 94 of the base plate 92 outside the adapter 180 in the radial direction. Each boss 124 is formed in a substantially cylindrical shape, and is erected from the base portion 94 toward one side in the axial direction. These bosses 124 are formed so as to face each other through the circular holes 116, and each boss 124 is provided with a pawl 130.

  Each pawl 130 includes a main body 132. The main body 132 is formed in a ring shape whose inner diameter dimension is slightly larger than the outer diameter dimension of the boss 124. By inserting the main body 132 into the boss 124 so that the boss 124 penetrates the main body 132, the pawl 130 is It is pivotally supported around 124. The boss 124 is provided with a torsion coil spring (not shown), and urges the pawl 130 around the boss 124 in the pulling direction side.

  A connecting piece 134 is formed on a part of the outer periphery of the main body 132. Each connecting piece 134 is formed so as to extend to the winding direction side of the spool 20 with respect to the main body 132 in a state where the main body 132 is pivotally supported by the boss 124. Further, each connecting piece 134 is rotated by a predetermined angle around the boss 124 in the winding direction so that the corner portion of the tip 134A is an adapter between the external teeth 186, 194 and the external teeth 186, 194 of the adapter 180 described above. It is formed so as to contact the outer peripheral portion of 180.

  Further, the distal end 134A of each connecting piece 134 is an inclined surface corresponding to the contact surface 196 of the cylindrical portion 192 described above.

  Here, as described above, since the bosses 124 are formed so as to face each other through the circular holes 116, the corners of the respective ends 134 </ b> A of both pawls 130 having the same shape are basically the cylindrical portions 192. When in contact with the contact surface 196, the tip end 134 </ b> A of the other pawl 130 is positioned on the opposite side of the tip end 134 </ b> A of the one pawl 130 via the axis of the adapter 180. Therefore, if the total number of external teeth 194 of the cylindrical portion 192 is an even number and the external teeth 194 are formed on the opposite side of any external tooth 194 via the axis of the adapter 180, both pawls 130 are provided. The leading ends 134 </ b> A are in contact with the contact surface 196.

  However, in the present embodiment, as described above, the total number of external teeth 194 and 186 is an odd number. Therefore, in a state where the tip 134A of one pawl 130 is in contact with the contact surface 196, the tip 134A of the other pawl 130 is separated from the external teeth 194 along the circumferential direction of the cylindrical portion 192 ( That is, the tip 134A of the other connecting piece 134 is not in contact with the contact surface 196).

  In addition, the clutch 90 includes a turntable 140. The turntable 140 includes a substantially plate-like base portion 142 that has a thickness direction along the axial direction of the base plate 92 and the adapter 180. A circular hole 144 is formed in the base portion 142. The inner diameter dimension of the circular hole 144 is slightly larger than the outer diameter dimension of the cylindrical portion 114, and the cylindrical portion 114 is assembled so that the cylindrical portion 114 penetrates the circular hole 144. The adapter 180 is pivotally supported so as to be rotatable around.

  A block 146 is formed on the surface of the base portion 142 on the base portion 94 side. These blocks 146 are formed so as to face each other through the circular hole 144, and one of the bosses 124 described above is located in one gap between the pair of blocks 146 outside the circular hole 144. The other boss 124 is located in the gap between the pair of blocks 146 on the opposite side of the gap via 144.

  A pressing piece 154 is provided on the inner peripheral portion of each block 146. These pressing pieces 154 are arranged on the winding direction side of the pawl 130, and are directed to the block 146 along the peripheral wall 156 formed in the block 146 so as to be coaxially curved with respect to the circular hole 144 (that is, , Relative to the turntable 140).

  Further, a compression coil spring 158 is provided on the side of the pressing piece 154 opposite to the pawl 130. The compression coil spring 158 is arranged in a curved state along the peripheral wall 156. One end of the compression coil spring 158 is engaged with and connected to the end of the pressing piece 154 opposite to the pawl 130. On the other hand, the other end of the compression coil spring 158 is in contact with the abutting wall 160 formed on the rotating disk 140 on the side opposite to the pressing piece 154 and is directed from the abutting wall 160 toward the pressing piece 154. A protrusion (not shown) formed to protrude is engaged and connected.

  A slope 164 is formed at the outer end in the width direction of the connecting piece 134 of each pawl 130 corresponding to each pressing piece 154. The inclined surface 164 is inclined outward in the radial direction of the base plate 92 with respect to the winding direction, and is pressed along the circumferential direction of the base plate 92 and the turntable 140 when the tip 134A is not in contact with the outer peripheral portion of the adapter 180. Opposite the piece 154.

  The pressing piece 154 is formed so that the base plate 92 contacts the inclined surface 164 by rotating the base plate 92 by a predetermined amount relative to the rotating disk 140 in the winding direction, and the base plate 92 further contacts the rotating disk 140 from this contact state. On the other hand, when the relative rotation in the winding direction is attempted, the inclined surface 164 is pressed in the pulling direction by the pressing piece 154, and the pawl 130 rotates around the boss 124 in the winding direction by this pressing force.

  A friction ring 170 is coaxially disposed between the base portion 142 of the rotating disk 140 and the cover 98. The friction ring 170 is formed in a ring shape as a whole, and a pair of tongue-like attachment pieces 172 are extended from the inner periphery of the friction ring 170 so as to face each other through the center of the friction ring 170. The pair of attachment pieces 172 are connected to the turntable 140 by screws or the like penetrating the base portion 142.

  A substantially C-shaped clutch spring 174 is provided on the outer periphery of the friction ring 170. One end of the clutch spring 174 is bent outward in the radial direction of the friction ring 170 and further bent in a substantially bowl shape.

  The front end portion of the clutch spring 174 is formed so as to engage with a predetermined portion of the leg plate 16 when the friction ring 170 rotates by a predetermined angle in the winding direction. In this engaged state, the friction ring 170 further moves in the winding direction. When rotating, the clutch spring 174 is tightened by the friction between the outer periphery of the friction ring 170 and the clutch spring 174, thereby further increasing the friction between the outer periphery of the friction ring 170 and the clutch spring 174. .

  Thus, the increased friction causes the rotation of the friction ring 170 in the winding direction, and consequently the rotation of the rotating plate 140 in the winding direction.

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

(Basic operation of webbing take-up device 10)
First, the basic operation of the webbing take-up device 10 will be described.

  In the webbing take-up device 10, when the webbing belt 28 is pulled while pulling a tongue plate (not shown) with the webbing belt 28 wound in layers on the spool 20, a spiral that urges the spool 20 in the winding direction. The webbing belt 28 is pulled out while rotating the spool 20 in the pulling direction against the urging force of the spring 34. In this manner, with the webbing belt 28 pulled out, the tongue plate is inserted into a buckle device (not shown) while the webbing belt 28 is hung around the front of the occupant seated on the seat, and the tongue plate is held by the buckle device. It becomes a wearing state.

  Further, when the webbing belt 28 is pulled out and the spool 20 is rotated in the pull-out direction in order to mount the webbing belt 28, the spiral spring 34 is tightened and the spool 20 is biased toward the winding direction. Power increases. Therefore, in the mounted state, the urging force of the spiral spring acts so as to wind the webbing belt 28 around the spool 20, so that basically, the urging force fits the webbing belt 28 to the occupant's body. The webbing belt 28 restrains and holds the occupant's body with a force according to the biasing force of the time.

  On the other hand, since the holding of the tongue plate by the buckle device is released and the tongue plate comes out of the buckle device, the force for maintaining the webbing belt 28 in the pulled-out state against the urging force of the spiral spring 34 is released. The spring 34 rotates the spool 20 in the winding direction with an urging force. The webbing belt 28 drawn out by the rotation of the spool 20 in the winding direction is wound around the outer periphery of the spool 20 in a layered manner, whereby the webbing belt 28 is stored.

  Here, since the spool 20 is fitted to the adapter 180 of the clutch 90, the adapter 180 rotates when the spool 20 is rotated for pulling out or winding the webbing belt 28. However, in this state, the adapter 180 simply rotates, and the base plate 92 and the turntable 140 do not rotate. Therefore, the pawl 130 does not rotate, and therefore the external gear 102 does not rotate. Therefore, the rotation of the spool 20 is not transmitted to the output shaft 73 of the motor 72 via the external gear 102 and the gears 70, 66, 64.

(Operation of webbing retractor 10 when approaching front obstacle)
On the other hand, in the traveling state of the vehicle, a monitoring signal is radiated from the front monitoring sensor 86 toward the front side of the vehicle. The emitted monitoring signal is reflected by an obstacle in front of the vehicle and received by the front monitoring sensor 86. In the calculation unit 84, the distance from the vehicle to the obstacle is calculated based on the time from when the monitoring signal is emitted from the front monitoring sensor 86 to when it is received. The calculation result in the calculation unit 84 is input to the ECU 78 as an electric signal (voltage or the like), and the ECU 78 determines whether the distance from the vehicle to the obstacle is less than a predetermined value based on the calculation result from the calculation unit 84. The

  Next, when the ECU 78 determines that the distance to the obstacle is less than the predetermined value, the ECU 78 outputs a control signal to the driver 74 and causes a current to flow to the motor 72 via the driver 74. As a result, the motor 72 is driven to rotate forward at a speed equal to or higher than a predetermined value, and the output shaft 73 is rotated forward.

  The rotation of the output shaft 73 is transmitted to the external gear 102 of the clutch 90 while being decelerated via the gears 64, 66, 70, and rotates the external gear 102 in the winding direction at a rotational speed of a predetermined value or more. Since the external gear 102 is mechanically connected to the base plate 92 via the torque limiter 104, the base plate 92 rotates integrally in the winding direction when the external gear 102 rotates in the winding direction.

  Thus, when the base plate 92 rotates relative to the turntable 140 by a predetermined amount or more in the winding direction, the pressing piece 154 provided on the block 146 of the turntable 140 comes into contact with the connecting piece 134 of the pawl 130. In this state, when the base plate 92 further rotates relative to the turntable 140 in the winding direction, the pressing piece 154 presses the inclined surface 164 of the connecting piece 134 in the pulling direction.

  The pressing force applied to the inclined surface 164 acts in the pull-out direction and inward in the radial direction of the rotating disk 140 and the base plate 92, and this radially inward action causes the pawl 130 in the initial state shown in FIG. Rotate around 124 in the winding direction. By rotating the pawl 130 around the boss 124 in the winding direction, first, as shown in FIG. 5, the corner portion of the tip 134 </ b> A contacts the contact surface 196 of the external tooth 194 of the cylindrical portion 192.

  Since the contact surface 196 faces the tip 134A in the tangential direction of the cylindrical portion 192, the pawl 130 that rotates together with the base plate 92 in the winding direction presses the contact surface 196 in the winding direction.

  Further, in this state, since the external gear 102 is rotated in the winding direction at a rotational speed equal to or higher than a predetermined value, the corner portion of the tip 134A corresponds to the rotational speed to the contact surface 196 of the external tooth 194. Due to the applied pressing force, the cylindrical portion 192 rotates in the winding direction against the urging force of the torsion coil spring 198.

  As the cylindrical portion 192 rotates against the biasing force of the torsion coil spring 198, the external teeth 194 of the cylindrical portion 192 approach the external teeth 186 of the adapter body 182 that have been out of phase until then. (As shown in FIG. 6).

  In this way, when the external teeth 194 approach the external teeth 186 and the phases of the external teeth 194 and the external teeth 186 are substantially matched, the tip 134A of the pawl 130 becomes the interference surface 188 of the external teeth 186 and the outer peripheral portion of the adapter body 182. Go in between 184.

  Here, as described above, the pawl 130 is biased in the pull-out direction by the biasing force of the torsion coil spring. In this state, the interference surface 188 of the external tooth 186 is located on the pull-out direction side of the tip 134A. positioned. For this reason, if the pawl 130 tries to rotate in the pull-out direction by the biasing force of the torsion coil spring, the tip 134A is interfered by the interference surface 188, and the rotation of the pawl 130 in the pull-out direction is restricted.

  Therefore, in this state, the engagement state between the adapter 180 and the pawl 130 is not released.

  In this state, when the pawl 130 further rotates in the winding direction together with the base plate 92, the tip end 134A of the pawl 130 presses the interference surface 188 (that is, the external teeth 186) in the winding direction, and the adapter main body 182, and thus the spool 20 Rotate in the winding direction. The webbing belt 28 is wound around the spool 20 by the rotation of the spool 20.

  As a result, loosening of the webbing belt 28, so-called "slack", is eliminated, and the restraining force of the webbing belt 28 on the occupant's body is improved, and the occupant then performs sudden braking (rapid braking) operation on the vehicle. Even if the vehicle is suddenly decelerated, the webbing belt 28 can reliably hold the occupant's body.

  Next, for example, when the vehicle avoids the obstacle by a steering operation or the like and no obstacle exists on the front side of the vehicle, the ECU 78 determines that the distance from the vehicle to the obstacle is equal to or greater than a predetermined value. Is done.

  As described above, when it is determined that the distance from the vehicle to the obstacle is less than the predetermined value and then the distance from the vehicle to the obstacle is equal to or greater than the predetermined value, the ECU 78 outputs a control signal to the driver 74. Then, a current is supplied to the motor 72 through the driver 74 for a predetermined time. As a result, the motor 72 is reversely driven, and the output shaft 73 is reversely rotated for a predetermined time.

  Thus, by rotating the output shaft 73 in the reverse direction, the base plate 92 rotates in the predetermined angle drawing direction, and further, the pawl 130 rotates in the predetermined angle pulling direction together with the base plate 92. By rotating the pawl 130 together with the base plate 92 in a pulling-out direction by a predetermined angle, the tip of the pawl 130 comes out between the interference surface 188 of the external teeth 186 and the outer peripheral portion 184 of the adapter main body 182.

  Thereby, the interference of the interference surface 188 with respect to the tip 134A is released, and the pawl 130 can rotate around the boss 124 in the pull-out direction. In this state, the pawl 130 is returned to the initial position by the biasing force of the torsion coil spring that biases the pawl 130 around the boss 124 in the pull-out direction.

  Thereby, the engagement between the adapter 180 and the pawl 130 can be reliably released, and the mechanical connection between the base plate 92 and the adapter 180, that is, the mechanical connection between the output shaft 73 of the motor 72 and the spool 20 can be released.

(Operation of the webbing take-up device 10 when the belt is stored)
On the other hand, when the occupant gets off, the wearing state of the webbing belt 28 is released. When releasing the mounting state, the tongue plate is pulled out from the buckle device. Extraction of the tongue plate from the buckle device is detected by a buckle switch 88.

  In this state, when an electrical signal from the buckle switch 88 is input to the ECU 78, the ECU 78 outputs a control signal to the driver 74 and causes a current to flow to the motor 72 via the driver 74. As a result, the motor 72 is driven to rotate forward at a speed less than a predetermined value, causing the output shaft 73 to rotate forward.

  Thus, the forward rotation of the output shaft 73 is transmitted to the external gear 102 in the same manner as when the distance to the obstacle ahead of the vehicle is less than a predetermined value, and the rotational speed of the external gear 102 is less than the predetermined value. Rotate in the winding direction with. Further, the rotation of the external gear 102 is transmitted to the base plate 92, the base plate 92 rotates in the winding direction, and the pressing piece 154 rotates the pawl 130 around the boss 124 in the winding direction. Thereby, as shown in FIG. 5, the corner portion of the tip 134 </ b> A contacts the contact surface 196 of the external tooth 194 of the cylindrical portion 192, and presses the contact surface 196 in the winding direction.

  However, as described above, in this case, the driving speed of the motor 72 is less than a predetermined value. For this reason, the pressing force applied to the contact surface 196 by the tip 134 </ b> A cannot be resisted against the urging force of the coil spring 198.

  Therefore, when the cylindrical surface 192 rotates in the winding direction by pressing the contact surface 196 against the tip 134A, the biasing force of the torsion coil spring 198 causes the adapter body 182 to follow and rotate in the winding direction. As a result, the spool 20 is rotated in the winding direction, and the webbing belt 28 is wound on the spool 20 from the longitudinal base end side.

  Here, in this state, the adapter main body 182 is rotated following the cylindrical portion 192 by the biasing force of the torsion coil spring 198 as described above. Therefore, the outer teeth 194 and the outer teeth 186 are kept out of phase, and the tip 134A of the pawl 130 does not enter between the interference surface 188 of the outer teeth 186 and the outer peripheral portion 184 of the adapter body 182.

  Therefore, in this state, the rotation of the pawl 130 in the pull-out direction around the boss 124 is restricted only by the friction at the contact portion between the external teeth 194 and the tip 134A, and basically the pawl 130 is pulled in the pull-out direction. Rotation is possible.

  Here, for example, when the occupant pulls the webbing belt 28 while temporarily removing the tongue plate from the buckle device in order to reattach the webbing belt 28, the driving force of the motor 72 causes the adapter body 182 to wind. The spool 20 tries to rotate in the take-out direction, but the spool 20 tends to rotate in the pull-out direction by pulling the webbing belt 28.

  Even in such a case, the rotation of the adapter main body 182 is stopped by the rotational force applied to the spool 20 in the drawing direction. In this way, the lock current flows through the motor 72 when the rotation of the adapter main body 182 is stopped. When the ECU 78 detects that a lock current has flowed to the motor 72, it outputs a control signal to the driver 74 and interrupts the current flowing to the motor 72.

  Thus, when the motor 72 is stopped, the pressing force from the tip 134A of the pawl 130 that has been applied to the contact surface 196 until then is released. When the application of the pressing force to the contact surface 196 is canceled in this way, the pawl 130 rotates in the pull-out direction around the boss 124 by the urging force of the torsion coil spring that urges the pawl 130. The engaged state with the pawl 130 is released. For this reason, in this state, the driving force of the motor 72 is not transmitted to the spool 20.

  As a result, the driving force of the motor 72 does not become a resistance when the webbing belt 28 is pulled out, and the occupant can smoothly pull out the webbing belt 28 without feeling uncomfortable, holding, or feeling excessive weight.

  Furthermore, in the present embodiment, as described above, the total number of external teeth 186 (same for external teeth 194) of the adapter 180 is an odd number, and the tip 134A of one pawl 130 is in contact with the contact surface 196. In the state, the tip 134A of the other pawl 130 is separated from the contact surface 196 along the circumferential direction of the adapter 180, and is adjacent to the external teeth 194 adjacent in the winding direction along the circumferential direction of the adapter 180 in the pull-out direction. It is located in the middle part with the external teeth 1194.

  In other words, in the present embodiment, in the state where the tips 134A of both pawls 130 are in contact with the contact surface 196, the distance from the tip 134A of one pawl 130 to the tip 134A of the other pawl 130 is the external teeth 186, 194. It is not an integral multiple of the pitch. Therefore, if both pawls 130 rotate around the boss 124, even if the tip 134A of one pawl 130 contacts the contact surface 196, the tip of the other pawl 130 contacts the contact surface 196. Without contacting the outer peripheral portion of the cylindrical portion 192 between the external teeth 194 adjacent in the circumferential direction.

  Therefore, even if the tip end 134A of one pawl 130 cannot contact and mesh with the contact surface 196, the tip end 134A of the other pawl 130 can be obtained by rotating the base plate 92 by approximately half a pitch of the external teeth 194. Reliably contacts the contact surface 196. For this reason, the rotation of the base plate 92 can be reliably and quickly transmitted to the adapter 180, and the rotational force of the motor 72 can be transmitted to the spool 20.

  Further, when the tip 134A of one pawl 130 is in contact with the contact surface 196, the connecting piece 134 is in contact with the pressing piece 154 in this state. Here, if the pressing piece 154 is integral with the turntable 140, the relative rotation in the winding direction of the base plate 92 with respect to the turntable 140 beyond that is restricted. In this state, the interference of the pressing piece 154 with the tip of the other pawl 130 is insufficient, and the pressing piece 154 cannot sufficiently rotate the other pawl 130 in the winding direction. There is a possibility that the tip 134A of the pawl 130 cannot be brought into contact with the contact surface 196.

  Here, in the present embodiment, as described above, the connecting piece 134 contacts the pressing piece 154 while the tip 134A of one pawl 130 is in contact with the contact surface 196. In this state, the base plate 92 is further moved. When attempting to rotate relative to the turntable 140 in the winding direction, the tip 134A of the pawl 130 presses the pressing piece 154 and displaces it in the winding direction against the urging force of the compression coil spring 158. As a result, the base plate 92 rotates relative to the turntable 140 in the winding direction.

  For this reason, the pressing piece 154 corresponding to the other pawl 130 interferes with the tip 134A of the other pawl 130 and rotates the pawl 130 in the winding direction. As a result, even if the connecting piece 134 contacts the pressing piece 154 while the tip 134A of one pawl 130 is in contact with the contact surface 196, the tip 134A of the other pawl 130 is brought into contact with the contact surface 196. Thus, the rotation of the base plate 92 can be reliably transmitted to the adapter 180.

  On the other hand, as described above, the spool 20 is rotated in the winding direction by the rotational force of the motor 72, so that the restraining force of the webbing belt 28 on the occupant body is improved. In the state where the belt 28 is wound, the occupant's body becomes an obstacle and basically the webbing belt 28 cannot be wound around the spool 20 any more. In this state, if the spool 20 further rotates in the winding direction to wind up the webbing belt 28, the webbing belt 28 tightens the occupant's body with an excessive force, which is not preferable.

  Here, as described above, when the spool 20 tries to wind up the webbing belt 28 more than necessary, the occupant's body becomes an obstacle to the winding of the webbing belt 28, and the spool 20 winds up the webbing belt 28. A tensile force having a magnitude corresponding to the winding force is applied to the webbing belt 28 from the occupant's body. Since this tensile force acts in the direction opposite to the direction in which the spool 20 winds up the webbing belt 28, the spool 20 stops when the tensile force is applied to the webbing belt 28.

  In this state, the rotational force of the motor 72 is applied to the spool 20 via the external gear 102, the base plate 92, the pawl 130, and the adapter 180. Therefore, when the spool 20 is stopped, the external teeth 186 of the adapter 180 are stopped. , 194 restricts the rotation of the pawl 130 around the center of the base plate 92, and the pawl 130 restricts the rotation of the base plate 92 in the winding direction. Further, the base plate 92 restricts the rotation of the external gear 102 in the winding direction via the torque limiter 104.

  Here, in a state where the rotation of the external gear 102 by the base plate 92 via the torque limiter 104 is restricted, the external gear 102 further attempts to rotate in the winding direction, and the rotational force at this time is the spring of the torque limiter 104. When the force is exceeded, the engaging portion 106 of the torque limiter 104 comes out of the engaging recess 100. Thereby, the connection between the base plate 92 and the external gear 102 is temporarily released, and only the external gear 102 rotates in the winding direction until the engaging portion 106 enters the other adjacent engaging recess 100.

  As described above, the connection between the base plate 92 and the external gear 102 is released, so that the transmission of the rotational force of the external gear 102 to the base plate 92, that is, the transmission of the rotational force of the motor 72 to the spool 20 is cut off. Therefore, an increase in restraining force by the webbing belt 28 can be suppressed.

  As described above, the clutch 90 used in the webbing retractor 10 not only has a function of transmitting a rotational force, but also rotates by the torque limiter 104 when an excessive rotational force is applied. Can block power transmission. Although the above effects can be obtained, the width dimension of the torque limiter 104 (the dimension along the axial direction of the external gear 102) is less than the axial dimension of the external gear 102, and the rotating disk 140 and torque All the limiters 104 are arranged between the external gear 102 along the radial direction of the external gear 102 and the peripheral wall 96 of the base plate 92.

  Moreover, members such as the pawl 130 and the turntable 140 are also arranged between the peripheral wall 96 and the adapter 180 along the radial direction of the peripheral wall 96, and these members are accommodated inside the external gear 102. For this reason, the thickness dimension (axial dimension) of the clutch 90 is substantially the axial dimension of the external gear 102 and becomes extremely thin.

  Thus, the webbing retractor 10 can be downsized by reducing the thickness of the clutch 90 provided with the torque limiter 104.

  In the present embodiment, the motor 72 is driven in reverse rotation so that the tip 134A of the pawl 130 is pulled out between the interference surface 188 of the external teeth 186 and the outer peripheral portion 184 of the adapter main body 182. The tip 134A of the pawl 130 may be pulled out from between the interference surface 188 of the external teeth 186 and the outer peripheral portion 184 of the adapter main body 182 by the biasing force of the torsion coil spring 198 without using the driving force 78.

It is a front sectional view showing the outline of the whole composition of the webbing take-up device concerning one embodiment of the present invention. It is a disassembled perspective view which shows the whole structure of the clutch mechanism which concerns on one embodiment of this invention. It is a disassembled perspective view which shows the structure of the principal part of the clutch mechanism which concerns on one embodiment of this invention. It is a figure which shows operation | movement of a clutch mechanism, and is a figure which shows the state which has a connection member in an initial position. FIG. 5 is a view corresponding to FIG. 4 illustrating a state in which the connecting member is in contact with the relative rotation member. FIG. 5 is a view corresponding to FIG. 4 illustrating a state in which the connecting member presses and rotates the relative rotating member, and the connecting member is engaged with the driven side rotating body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Webbing winding device 20 Spool 28 Webbing belt 72 Motor (drive means)
90 Clutch (clutch means, clutch mechanism)
102 External gear (motor side rotating body)
130 pawl (clutch member)
180 Adapter (driven rotor)
182 Adapter body (second rotating body)
192 Tubular part (first rotating body)
198 Torsion coil spring (connecting member, biasing means)

Claims (4)

A driving-side rotating body that rotates when a rotational force is input;
A driven-side rotating body that rotates by transmitting the rotation of the driving-side rotating body;
It is displaced in a predetermined connecting direction in conjunction with the rotation of the driving side rotating body, and the rotation of the driving side rotating body is transmitted to the driven side rotating body by the displacement in the connecting direction so that the driven side rotating body is A rotating clutch member;
Including a clutch mechanism,
When the driving side rotating body rotates at a rotational speed of any one of the predetermined value and less than the predetermined value, the displacement of the clutch member in the release direction opposite to the connecting direction is restricted, and the driving side While maintaining the connected state of the rotating body and the driven-side rotating body, and when the driving-side rotating body is rotating at a rotational speed of either the predetermined value or more and less than the predetermined value, the clutch member is Not receive,
A clutch mechanism characterized by that. The clutch member displaced in the coupling direction along the rotation direction when rotating by receiving the rotation of the driving side rotating body has a contact portion that contacts, and the contact portion is pressed by the clutch portion. A first rotating body that rotates by
The first rotating body is provided so as to be relatively rotatable coaxially with respect to the first rotating body, and the first rotating body is relatively rotated by a predetermined angle by a pressing force from the clutch member in a state where the clutch member is in contact with the contact portion. The clutch member is engaged by rotating, is rotated by being pressed by the clutch member in the engaged state, and interferes with the clutch member from the release direction side in the engaged state to the clutch member toward the release direction side. A second rotating body having an interference part for regulating the displacement of
The first rotating body and the second rotating body are connected so as to be rotatable relative to each other by a predetermined angle, and either one of the first rotating body and the second rotating body is rotated by the other rotating body. A connecting member that transmits and rotates any one of the rotating bodies;
The first rotating body is biased with respect to the second rotating body in a direction opposite to the rotating direction when the rotational force from the driving side rotating body is received, and the biasing direction side from the engageable position. Biasing means for displacing the abutable position by the predetermined angle;
The driven-side rotating body is configured to output the rotation of the first rotating body or the second rotating body, and when the driving-side rotating body rotates at the predetermined rotational speed or more, the first rotating body is rotated. The rotating body rotates relative to the second rotating body against the biasing force of the biasing means;
The clutch mechanism according to claim 1. The longitudinal base end side of the long belt-like webbing belt that restrains the occupant's body in a mounted state with respect to the body of the vehicle occupant is locked to the spool, and the spool is rotated in one winding direction around the axis. A webbing take-up device for taking up and storing a webbing belt from the base end side,
Driving means for rotating the output shaft with its own driving force;
A clutch member that is displaced in a predetermined coupling direction in conjunction with the rotation of the output shaft, and the clutch member is displaced in the coupling direction, whereby the rotation of the output shaft is transmitted to the spool and the spool is When the output shaft is rotated in the winding direction and the output shaft is rotated at a rotational speed of at least a predetermined value or less, displacement of the clutch member in the release direction is restricted and the output shaft And a clutch means for maintaining the coupling state between the spool and the spool, and the clutch member is not subject to the restriction when the output shaft is rotated at a rotational speed of any one of the predetermined value and the predetermined value.
A webbing take-up device comprising: The driving means is operated when the distance from the obstacle to the vehicle is a predetermined value or less, and the output shaft is rotated at any one of the rotation speeds, and the driving is performed when the mounted state is released. A control means for operating the means and rotating the output shaft at the other rotational speed;
The webbing take-up device according to claim 3.

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