JP2014046856A - Webbing take-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a webbing take-up device capable of increasing load that is required for a rotating body near a motor to rotate relative to a rotating body near a spool.SOLUTION: An adaptor 182 comprises: a large diameter shaft portion 184 to which a coil portion of a coil spring 130 is welded with pressure by elastic force; and a cylindrical portion 186 coaxial to and integral with the large diameter shaft portion 184 on the outside of the larger diameter shaft portion 184. A ratchet gear 114 rotates relative to the adaptor 182 in the take-up direction to loosen the coil spring 130 so that friction between the coil portion of the coil spring 130 and the outer peripheral portion of the larger diameter shaft portion 184 decreases. The loosened coil spring 130, however, is welded with pressure to the inner peripheral portion of the cylindrical portion 186, so that rotative force required for the ratchet gear 114 to rotate relative to the adaptor 182 in the take-up direction exceeds friction force between the coil portion of the coil spring 130 and the outer peripheral portion of the large diameter shaft portion 184 and friction force between the coil portion of the coil spring 130 and the inner peripheral portion of the cylindrical portion 186.

Description

  The present invention relates to a webbing take-up device that constitutes a seat belt device of a vehicle, and more particularly to a webbing take-up device capable of rotating a spool by a driving force of a motor.

  FIG. 14 of Patent Document 1 below shows a webbing take-up device (referred to as “seat belt device” in Patent Document 1) that can rotate a spool (referred to as “spindle” in Patent Document 1) by the driving force of a motor. A torque limiter mechanism is disclosed. In this torque limiter mechanism, a small-diameter side gear (spindle side gear) that is a spool-side rotator is coaxially provided inside a large-diameter side gear (actuator-side gear) that is a motor-side rotator. A limit spring (elastic piece) that is a rotation transmission member is provided between the large-diameter side gear and the small-diameter side gear.

  One end of the limit spring is inserted into a slit opened at the outer peripheral portion of the small-diameter side gear. On the other hand, the limit spring has a protrusion at the other end. Corresponding to this protrusion, a continuous wave-shaped unevenness is formed in the inner peripheral portion of the large-diameter side gear, and the protrusion of the limit spring enters one of the recesses of the wave-shaped unevenness.

  When the large-diameter side gear is rotated by the driving force of the motor, this rotational force is transmitted to the small-diameter side gear via the limit spring and rotates the spool. Also, when the driving force of the motor for rotating the spool in the winding direction is transmitted to the large-diameter side gear, for example, when the webbing is pulled and the rotational force in the pulling direction is input to the spool When the rotational force of the large-diameter side gear exceeds the biasing force (elastic force) of the limit spring, the large-diameter side gear rotates relative to the limit spring, and at this time, the protrusion of the limit spring becomes the concave portion of the large-diameter side gear. Get out of. Thereby, the large-diameter side gear can rotate relative to the small-diameter side gear.

Pamphlet of International Publication No. 2006/123750

  By the way, when the protrusion of the limit spring enters the adjacent recess after getting out of the protrusion of the limit spring from the recess of the large diameter gear and overcoming the protrusion of the large diameter gear, the protrusion of the limit spring Strike the recessed part with the elastic force. Thereby, an impact sound is generated.

  Instead of a leaf spring-shaped limit spring, one end is locked to the large-diameter side gear part, and a coil spring that winds around the small-diameter side gear part is used for friction between the coil spring and the small-diameter side gear part. A configuration in which the rotation of the gear is transmitted to the small-diameter side gear portion can be considered. With such a configuration, when the large-diameter side gear portion rotates relative to the small-diameter side gear portion, the coil spring only expands in diameter, so that no collision noise is generated. However, in the configuration using the coil spring, it is difficult to increase the load that causes the large-diameter side gear portion to rotate relative to the small-diameter side gear portion by expanding the diameter of the coil spring.

  In view of the above fact, an object of the present invention is to obtain a webbing take-up device that can increase the load required when the motor-side rotating body rotates relative to the spool-side rotating body.

  The webbing take-up device according to the first aspect of the present invention includes a spool that winds up the webbing by being locked in a longitudinal direction proximal end side of the webbing and rotating in one winding direction around an axis. A spool-side rotating body that is provided integrally with the spool or that is directly or indirectly connected to the spool, transmits rotation in a predetermined direction to the spool, and rotates the spool in the winding direction; and a motor A motor-side rotating body that is rotated in the predetermined direction by being transmitted with the driving force of the motor, and a first pressure contact portion provided on one of the spool-side rotating body and the motor-side rotating body A part of the second pressure contact portion provided on the one rotating body and the other rotating body of the spool-side rotating body and the motor-side rotating body, together with the other rotating body. Rotate and before Another part different from the part is pressed against the first pressure contact part by an urging force to transmit the rotation of the motor side rotating body to the spool side rotating body and rotate the spool. The rotation transmission member in which the pressure contact with the first pressure contact portion is loosened by the relative rotation of the motor-side rotating body in the predetermined direction, and the rotation of the rotation transmission member with respect to the first pressure contact portion is loosened with the rotation. In the state where the pressure transmission member is press-contacted and the rotation transmission member is in pressure contact, the load generated by the pressure contact is a load required for relative rotation of the rotation transmission member with respect to the one rotation body. And a second pressure contact part to be added.

  In the webbing take-up device according to the first aspect of the present invention, the rotation transmitting member is interposed between the spool side rotating body and the motor side rotating body. The rotation transmitting member is in pressure contact with the first pressure contact portion provided on one of the spool-side rotating body and the motor-side rotating body with an urging force, and the spool-side rotating body and the motor-side rotating body Part of the other rotating body is engaged. Thus, when the motor-side rotating body rotates in a predetermined direction by the driving force of the motor, the rotation in the predetermined direction is transmitted to the spool-side rotating body via the rotation transmitting member, and the spool-side rotating body rotates in the predetermined direction. Thus, when the spool side rotating body rotates in a predetermined direction, the spool rotates in the winding direction, and the webbing is wound around the spool.

  On the other hand, for example, rotation of the spool-side rotator in a predetermined direction is directly or indirectly restricted, or the motor-side rotator is applied with a rotational force in a direction opposite to the predetermined direction. Is rotated in a predetermined direction, the pressure contact of the rotation transmitting member with respect to the first pressure contact portion is loosened. Thereby, the rotation transmission member slips and rotates with respect to the first pressed contact portion, that is, one of the rotating bodies. Thus, even if the motor-side rotating body rotates in a predetermined direction, this rotation is not transmitted to the spool-side rotating body, and the spool-side rotating body rotates in the predetermined direction, and consequently the spool rotates in the winding direction. Can be suppressed.

  However, one rotary body provided with the first pressure contact portion is provided with a second pressure contact portion. When the pressure transmission of the rotation transmission member to the first pressure contact portion is loosened, the rotation transmission member is moved to the second pressure contact portion. Press contact with the pressure contact part. When friction is generated between the rotation transmission member and the second pressure contact portion by the pressure transmission member being pressed against the second pressure contact portion in this manner, the rotation transmission member rotates relative to one of the rotating bodies. The load based on this friction is added to the load (rotational force) required for. Thereby, the load required for the rotation transmitting member to rotate relative to one of the rotating bodies can be increased.

  A webbing take-up device according to a second aspect of the present invention is the webbing take-up device according to the first aspect of the present invention, wherein one end is engaged with the other rotating body and the other end side is formed in a coil shape. The first pressed contact portion is provided on one of the inner side and the outer side of the portion so that the coil portion is in pressure contact with the first pressed contact portion, and the second on the inner side and the outer side of the coil portion. A pressure contact portion is provided so that the pressure contact with the first pressure contact portion is loosened and the coil portion is expanded or contracted so as to be separated from the first pressure contact portion. The coil spring to be used is the rotation transmission member.

  In the webbing take-up device according to the second aspect of the present invention, the rotation transmission member is a coil spring, the coil portion is pressed against the first pressed contact portion with a biasing force, and one end is a spool-side rotating body and a motor. It is engaged with the other rotating body of the side rotating bodies. When the motor-side rotating body rotates relative to the spool-side rotating body in a predetermined direction, the coil portion of the coil spring is enlarged or reduced in diameter so as to be separated from the first pressed contact portion. Press contact with the second pressed contact portion. Thus, when friction occurs between the coil portion of the coil spring and the second pressed contact portion by the coil portion of the coil spring being pressed against the second pressed contact portion, the rotation transmission member is applied to one rotating body. A load based on this friction is added to a load (rotational force) required for relative rotation. Thereby, the load required for the coil part of the coil spring to rotate relative to the one rotating body can be increased.

  A webbing take-up device according to a third aspect of the present invention is the webbing retractor according to the second aspect of the present invention, wherein one of the first pressure contact portion and the second pressure contact portion is a shaft. The direction is along the axial direction of the one rotating body, and is formed in a cylindrical shape provided with the coil spring on the inside, and the other pressure contact portion of the first pressure contact portion and the second pressure contact portion is And provided inside the coil spring, and the axial direction is formed in a columnar shape or a cylindrical shape along the axial direction of the one rotating body.

  According to the webbing take-up device according to the third aspect of the present invention, one of the first pressure contact portion and the second pressure contact portion has an axial direction along the axial direction of the one rotating body. It is formed in a cylindrical shape provided with a coil spring inside. On the other hand, the other pressed contact portion of the first pressed contact portion and the second pressed contact portion is formed in a columnar shape or a cylindrical shape provided inside the coil spring.

  Therefore, if the one pressure contact portion formed in this cylindrical shape is the first pressure contact portion, the outer peripheral side of the coil portion of the coil spring is in pressure contact with the inner peripheral portion of the first pressure contact portion. When the motor-side rotating body rotates relative to the spool-side rotating body in a predetermined direction, and the press contact of the coil portion of the coil spring with respect to the first pressed contact portion is loosened, the coil portion of the coil spring is reduced in diameter, The inner peripheral side is in pressure contact with the second pressed contact portion.

  On the other hand, if the one pressure contact portion formed in the cylindrical shape is the second pressure contact portion, the first pressure contact portion is provided inside the coil portion of the coil spring, and the inside of the coil portion of the coil spring is The peripheral portion is in pressure contact with the first pressure contact portion. When the motor-side rotating body rotates relative to the spool-side rotating body in a predetermined direction, and the press contact of the coil portion of the coil spring with respect to the first pressed contact portion is loosened, the coil portion of the coil spring is expanded in diameter, The outer peripheral side press-contacts with the inner peripheral part of a cylindrical 2nd pressed contact part.

  A webbing retractor according to a fourth aspect of the present invention is the webbing retractor according to the third aspect, wherein the one pressed contact portion is formed in a cylindrical shape having a circular inner peripheral surface.

  In the webbing take-up device according to the fourth aspect of the present invention, one of the first pressure contact portion and the second pressure contact portion is formed in a cylindrical shape, but its inner peripheral shape is circular. And a coil spring is provided inside thereof.

  Therefore, if the one pressed contact portion formed in this cylindrical shape is the first pressed contact portion, the outer peripheral side of the coil portion of the coil spring is pressed relatively uniformly with the inner peripheral portion of the first pressed contact portion. On the other hand, if one pressure contact portion formed in a cylindrical shape is the second pressure contact portion, the outer peripheral side of the coil portion of the coil spring is the second pressure contact portion when the diameter of the coil portion of the coil spring is increased. The inner periphery of the plate is relatively evenly pressed.

  A webbing take-up device according to a fifth aspect of the present invention is the webbing take-up device according to the third or fourth aspect, wherein the other pressed contact portion is formed in a columnar shape or a cylindrical shape having a circular outer peripheral surface. Yes.

  In the webbing take-up device according to the fifth aspect of the present invention, the other pressed contact portion of the first pressed contact portion and the second pressed contact portion is formed in a columnar shape or a cylindrical shape. It is circular and is provided inside the coil portion of the coil spring.

  Therefore, if the other pressed contact portion is the first pressed contact portion, the inner peripheral side of the coil portion of the coil spring is pressed relatively uniformly with the inner peripheral portion of the first pressed contact portion. On the other hand, if the other pressure contact portion is the second pressure contact portion, the inner circumference side of the coil portion of the coil spring is compared with the outer circumference portion of the second pressure contact portion when the diameter of the coil portion of the coil spring is reduced. Press evenly.

  As described above, the webbing take-up device according to the present invention can increase the load required when the motor-side rotating body rotates relative to the spool-side rotating body.

It is a disassembled perspective view which shows the structure of the principal part of the webbing retractor which concerns on one embodiment of this invention. It is an expansion exploded perspective view of a motor side rotating body, a spool side rotating body, and a rotation transmission member. It is the side view to which the structure of the principal part of the webbing winding device concerning one embodiment of the present invention was expanded. FIG. 4 is a side view corresponding to FIG. 3 showing a state in which the motor-side rotating body is coupled to the motor and the driving force of the motor is transmitted to the spool-side rotating body via the motor-side rotating body and the rotation transmitting member. FIG. 4 is a side view corresponding to FIG. 3, showing a state where the motor side rotating body rotates relative to the spool side rotating body in the winding direction. It is a perspective view which shows the state which mounted | wore the interference piece in the gear box.

<Configuration of the present embodiment>
FIG. 1 is an exploded perspective view showing a configuration of a webbing take-up device 10 according to an embodiment of the present invention.

  As shown in this figure, the webbing take-up device 10 includes a frame 12 that is fixed to a vehicle body constituting member such as a skeleton member or a reinforcing member of a vehicle. The frame 12 includes leg plates 14 and 16 that face each other along the vehicle longitudinal direction when attached to the vehicle body.

  A spool 18 is provided between the leg plates 14 and 16. The spool 18 is formed in a substantially cylindrical shape whose axial direction is along the opposing direction of the leg plate 14 and the leg plate 16. A longitudinal end portion of the webbing 20 formed in a long band shape is locked to the spool 18. The spool 18 is wound in the winding direction, which is one of the circumferences of the central axis, to wind up and store the webbing 20 from the proximal end side in the longitudinal direction. For example, when the occupant wears the webbing 20 on the body, When 20 is pulled, the webbing 20 wound around the spool 18 is pulled out, and the spool 18 rotates in the pulling direction opposite to the winding direction.

  A torsion shaft (not shown) is provided inside the spool 18. The torsion shaft is a rod-shaped member whose axial direction is along the axial direction of the spool 18. The torsion shaft is connected to the spool 18 in a state in which the torsion shaft cannot be coaxially rotated relative to the spool 18 on the leg plate 16 side than the end on the leg plate 14 side.

  Further, a housing 24 of a locking mechanism 22 as a locking means is attached to the leg plate 14 on the side opposite to the leg plate 16 of the leg plate 14, and the end of the torsion shaft on the leg plate 14 side is the central axis of the spool 18. It is directly or indirectly supported by the housing 24 so as to be rotatable around. A so-called “VSIR mechanism” that operates when the vehicle is suddenly decelerated and restricts rotation of the end of the torsion shaft on the leg plate 14 side in the pull-out direction is configured inside the housing 24. Actuates when the rotational acceleration of the torsion shaft in a pull-out direction exceeds a predetermined magnitude, and the end of the torsion shaft on the leg plate 14 side is restricted from rotating in the pull-out direction. Various parts constituting a so-called “WSIR mechanism” are accommodated.

  Further, a pretensioner 26 as a force pulling means is provided on the side of the leg plate 14 opposite to the leg plate 16. The pretensioner 26 operates in a vehicle suddenly decelerating state. By operating, the pretensioner 26 applies a rotational force in the winding direction to the end of the torsion shaft on the leg plate 14 side or the spool 18 to force the spool 18. Rotate in the winding direction.

  On the other hand, a motor 40 is provided below the spool 18 between the leg plate 14 and the leg plate 16. The motor 40 includes a battery mounted on the vehicle via an ECU (not shown) as a control means, a forward monitoring device such as a radar device that measures the distance to another vehicle traveling in front of the vehicle, and an obstacle ahead of the vehicle. Is electrically connected. When the ECU determines that the distance to another vehicle traveling in front of the vehicle or an obstacle in front of the vehicle is less than a certain value based on the electrical signal output from the front monitoring device, the ECU activates the motor 40. In the motor 40, the axial direction of the output shaft 42 is the same as the axial direction of the spool 18, and the distal end side of the output shaft 42 passes through a through hole (not shown) formed in the leg plate 16 and is outside the leg plate 16 (leg plate). 16 on the side opposite to the leg plate 14).

  Further, a driving force transmission mechanism 50 is provided on the opposite side of the leg plate 16 from the leg plate 14. The driving force transmission mechanism 50 includes a gear box 52 attached to the leg plate 16 on the opposite side of the leg plate 16 from the leg plate 14. The gear box 52 is formed in a concave shape that opens toward the side opposite to the leg plate 16. A hole 54 is formed at the bottom of the gear box 52, and the output shaft 42 of the motor 40 that has passed through the hole of the leg plate 16 passes through the hole 54 and enters the inside of the gear box 52.

  An external gear spur gear 56 is coaxially and integrally attached to the output shaft 42 at the distal end side of the output shaft 42 that has entered the gear box 52. On the side of the gear 56, a support shaft 58 is formed at the bottom of the gear box 52. The support shaft 58 has the same axial direction as the output shaft 42. A two-stage gear 60 is supported on the support shaft 58 so as to be rotatable around the support shaft 58.

  The two-stage gear 60 is provided with a large-diameter gear 62 having external teeth and flat teeth. The large diameter gear 62 has a larger diameter than the gear 56 and has a larger number of teeth than the gear 56, and meshes with the gear 56. On the side of the large-diameter gear 62 in the axial direction, a small-diameter gear 64 having a flat tooth with external teeth having a smaller diameter than the large-diameter gear 62 is formed coaxially and integrally with the large-diameter gear 62. A support shaft 68 is formed at the bottom of the gear box 52 at the side of the rotational radius direction of the two-stage gear 60.

  The support shaft 68 has the same axial direction as the output shaft 42 and the support shaft 58. A two-stage gear 70 is supported on the support shaft 68 so as to be rotatable around the support shaft 68. The two-stage gear 70 includes a large-diameter gear 72 having external teeth and flat teeth. The large-diameter gear 72 has a larger diameter than the small-diameter gear 64 and has a larger number of teeth than the small-diameter gear 64, and meshes with the small-diameter gear 64. On the side in the axial direction of the large-diameter gear 72, a small-diameter gear 74 having flat teeth and outer teeth having a smaller diameter than the large-diameter gear 72 is formed coaxially and integrally with the large-diameter gear 72.

  A support shaft 78 is formed at the bottom of the gear box 52 at the side of the rotational radius direction of the two-stage gear 70. The support shaft 78 has the same axial direction as the output shaft 42 and the support shafts 58 and 68. A spur gear 80 with external teeth is rotatably supported on the support shaft 78 around the support shaft 78. The gear 80 has a larger diameter than the small diameter gear 74 and has a larger number of teeth than the small diameter gear 74, and meshes with the small diameter gear 74.

  A clutch 90 is provided on the side of the gear 80 in the radial direction of rotation. The clutch 90 includes an input gear 92. The input gear 92 includes a bottom wall portion 94. A circular hole 96 is formed in the bottom wall portion 94. A ring-shaped support portion 98 is formed at the bottom of the gear box 52 corresponding to the circular hole 96. The circular hole 96 is erected from the bottom of the input gear 92 toward the side opposite to the leg plate 14. Further, the support portion 98 is formed so that the center axis thereof is substantially coaxial with the center axis of the spool 18.

  The support portion 98 passes through the circular hole 96, and supports the bottom wall portion 94, that is, the input gear 92 so as to be rotatable around the central axis of the support portion 98. A spur gear portion 100 with external teeth is formed on the outer peripheral portion of the bottom wall portion 94. The gear portion 100 is coaxially formed with respect to the circular hole 96 of the bottom wall portion 94, has a larger diameter than the gear 80, and has more teeth than the gear 80, and meshes with the gear 80. ing. As described above, since the gear 80 is mechanically connected to the gear 56 provided on the output shaft 42 of the motor 40 via the two-stage gears 70 and 60, the motor 40 operates and the driving force is used. When the output shaft 42 rotates, the rotation of the output shaft 42 is decelerated and transmitted to the gear unit 100, and the gear unit 100, that is, the input gear 92 rotates.

  On the other hand, a pair of support shafts 102 are provided inside the gear unit 100. Each support shaft 102 has an axial direction that is the same as the axial direction of the circular hole 96, and is formed to project from the bottom wall portion 94 of the input gear 92 toward the side opposite to the leg plate 16. These support shafts 102 are formed to face each other through the center of the circular hole 96. These support shafts 102 are provided with connecting pawls 110. Each connecting pawl 110 is formed with a circular hole 112. The support shaft 102 passes through the circular hole 112, and each coupling pawl 110 is supported by the corresponding circular hole 112 so as to be rotatable around the central axis of the circular hole 112.

  A ratchet gear 114 as a motor-side rotating body is provided inside the gear unit 100. The ratchet gear 114 is attached to an adapter 182 as a spool-side rotating body that passes through the circular hole 96 of the bottom wall portion 94 and enters the inside of the gear portion 100. The adapter 182 is attached to the end of the torsion shaft on the leg plate 16 side so as not to rotate relative to the torsion shaft.

  As shown in each of FIGS. 1 to 3, the outer peripheral shape of the adapter 182 includes a large-diameter shaft portion 184 as a first pressure contact portion that is a circular shape that is substantially coaxial with the spool 18. A small-diameter shaft portion 166 having an outer diameter smaller than that of the large-diameter shaft portion 184 is formed coaxially with the large-diameter shaft portion 184 at one end of the large-diameter shaft portion 184. A small diameter shaft portion 166 of the adapter 182 passes through a circular hole 118 formed in the center of the ratchet gear 114, and the ratchet gear 114 is rotatably supported by the small diameter shaft portion 166.

  Further, a cylindrical portion 186 as a second pressed contact portion is provided outside the large diameter shaft portion 184. The cylindrical portion 186 is formed in a bottomed cylindrical shape having a bottom portion on the spool 18 side, and a large-diameter shaft portion 184 is coaxial with the inner peripheral portion and the outer peripheral portion of the cylindrical portion 186 at the bottom portion of the cylindrical portion 186. Is formed.

  The large-diameter shaft portion 184 of the adapter 182 is provided with a coil spring 130 constituting a rotation transmission member as an urging member. Assuming that the body portion of the coil spring 130 is a cylindrical shape, the coil spring 130 has an inner diameter dimension equal to or smaller than the outer diameter dimension of the large-diameter shaft portion 184 of the adapter 182, and as shown in FIG. The large-diameter shaft portion 184 passes through the inside. One end of the coil spring 130 is an engaging portion 132. The engaging portion 132 extends linearly from one end of the coil portion of the coil spring 130 in the tangential direction of the coil portion. In the coil spring 130, the direction of the spiral in the coil portion is set so that the coil portion is loosened when the engaging portion 132 (that is, one end side) is pressed in the winding direction.

  Further, the wire diameter of the coil spring 130 or the distance between the inner peripheral portion of the cylindrical portion 186 and the outer peripheral portion of the large-diameter shaft portion 184 is such that the coil portion of the coil spring 130 is in pressure contact with the large-diameter shaft portion 184. The coil portion of the coil spring 130 is separated from the inner peripheral portion of the cylindrical portion 186, and the outer peripheral side of the coil portion of the coil spring 130 is in the cylindrical portion 186 in a state where the coil portion of the coil spring 130 is loosened as described above. It is set so that it may press-contact with the inner peripheral part of.

  As shown in FIGS. 2 and 3, the ratchet gear 114 has a receiving hole 120 having a diameter larger than that of the circular hole 118 corresponding to one end side of the engaging portion 132 of the coil spring 130 and the coil portion of the coil spring 130. Is formed coaxially with the circular hole 118, and the circular hole 118 opens at the bottom of the accommodation hole 120. The inner diameter dimension of the accommodation hole 120 is set larger than the outer diameter dimension of the coil portion of the coil spring 130.

  Further, the ratchet gear 114 is formed with an engagement hole 134. The engagement hole 134 is formed outside the accommodation hole 120 and is connected to the accommodation hole 120 at one end thereof. One end side of the coil portion of the coil spring 130 enters the inside of the accommodation hole 120, and the engagement portion 132 enters the engagement hole 134 of the ratchet gear 114. For this reason, when the ratchet gear 114 rotates in the winding direction and the inner wall of the engagement hole 134 presses the engaging portion 132 in the winding direction, the coil portion of the coil spring 130 rotates in the winding direction.

  Further, as shown in FIG. 3, the coil portion of the coil spring 130 is in pressure contact with the adapter 182 on the inside by the biasing force. For this reason, when the coil portion of the coil spring 130 rotates in the winding direction, the friction between the coil spring 130 and the adapter 182 transmits the rotational force to the adapter 182 to rotate the adapter 182 in the winding direction.

  On the other hand, as shown in FIGS. 1 to 3, external ratchet teeth are formed on the outer periphery of the ratchet gear 114. As shown in FIG. 3, the coupling pawl 110 is formed with a meshing portion 122 corresponding to the ratchet teeth of the ratchet gear 114.

  As the connecting pawl 110 rotates to one side around the support shaft 102 penetrating the circular hole 112, the meshing portion 122 approaches the outer peripheral portion of the ratchet gear 114 as shown in FIG. The meshing part 122 meshes with the ratchet teeth. When the input gear 92 rotates in the winding direction around the support portion 98 with the meshing portion 122 engaged with the ratchet teeth of the ratchet gear 114, the meshing portion 122 of the connecting pawl 110 that rotates in the winding direction together with the input gear 92 is ratcheted. The gear 114 is pressed in the winding direction, and the ratchet gear 114 is rotated together with the input gear 92 in the winding direction.

  Here, the other support shaft 102 is formed so as to be shifted by 180 degrees around the rotation center of the input gear 92 with respect to the one support shaft 102. On the other hand, the ratchet teeth of the external teeth formed on the ratchet gear 114 are odd numbers. For this reason, when the meshing portion 122 of the coupling pawl 110 supported by one support shaft 102 meshes with the ratchet teeth of the ratchet gear 114, the meshing portion 122 of the coupling pawl 110 supported by the other support shaft 102 becomes the ratchet gear. 114 does not mesh with the ratchet teeth in contact with the intermediate portion of the slope of the ratchet teeth along the rotational circumferential direction. In such a configuration, when the ratchet gear 114 rotates by an angle that is half the ratchet tooth formation interval, the meshing portion 122 of any of the connecting pawls 110 meshes with the ratchet teeth of the ratchet gear 114.

  In the present embodiment, the number of ratchet teeth of the ratchet gear 114 is set to an odd number as described above, and both the support shafts 102 are formed in a state shifted by 180 degrees around the rotation center of the input gear 92. Accordingly, the meshing portion 122 of any of the connecting pawls 110 is configured to mesh with the ratchet teeth of the ratchet gear 114. The number of ratchet teeth of the ratchet gear 114 and the formation position of the support shaft 102 that supports the connecting pawl 110 are not limited to such a mode.

  Accordingly, the number of ratchet teeth of the ratchet gear 114 and the position where the support shaft 102 for supporting the connection pawl 110 is formed are set so that the meshing portions 122 of both the coupling pawls 110 mesh with the ratchet teeth of the ratchet gear 114 substantially simultaneously. May be. Moreover, although this Embodiment was the structure which has the two connection pawls 110, the structure provided with three or more connection pawls 110 may be sufficient, and the structure which provides only one connection pawl 110 may be sufficient. Good.

  On the other hand, a support pin 124 is formed on the bottom wall portion 94 on the drawing direction side along the rotational circumferential direction of the input gear 92 with respect to the support shaft 102. A return spring 126 is attached to each of these support pins 124. The return spring 126 is a torsion coil spring having a coiled middle portion, and one end thereof is locked to a locking portion (not shown) formed on the bottom wall portion 94. On the other hand, the other end side of the return spring 126 is in pressure contact with the spring contact portion 128 of the connecting pawl 110, and the other side around the support shaft 102, that is, the meshing portion 122 is separated from the outer peripheral portion of the ratchet gear 114. The connecting pawl 110 is biased in the direction.

  The clutch 90 includes a pair of interference pieces 140. As shown in FIG. 6, the interference piece 140 includes a base portion 142. The base 142 is formed in a narrow plate shape whose width direction is along the height direction of the interference piece 140, that is, the axial direction of the spool 18. An outer retaining ring 146 and an inner retaining ring 148 are formed at the bottom of the gear box 52 corresponding to the base portion 142.

  The outer holding ring 146 and the inner holding ring 148 are formed in a ring shape coaxial with the support portion 98 and are erected from the bottom of the gear box 52 toward the opposite side to the leg plate 16. . The base portion 142 of the interference piece 140 is inserted between the outer holding ring 146 and the inner holding ring 148, and on the inner peripheral portion of the outer holding ring 146 or the outer peripheral portion of the inner holding ring 148 due to its spring property. It is in pressure contact.

  One end portion in the width direction of the base portion 142 (that is, the end portion in the width direction of the base portion 142 opposite to the bottom portion of the support portion 98 in a state where the base portion 142 is inserted between the outer holding ring 146 and the inner holding ring 148). An interference portion 152 extends from the longitudinal center side of the base portion 142. As shown in FIGS. 1 and 2, a through hole 154 is formed in the bottom wall portion 94 of the input gear 92 corresponding to the interference portion 152. The through hole 154 is formed in the vicinity of the meshing portion 122 of the connecting pawl 110 supported by the support shaft 102. In the interference piece 140 in which the base portion 142 is disposed between the outer holding ring 146 and the inner holding ring 148, the interference portion 152 passes through the through-hole 154, and particularly when the interference piece 140 is in an initial state, the input gear 92 is rotated. The interference part 152 faces the meshing part 122 on the winding direction side of the meshing part 122 along the circumferential direction.

  On the other hand, as shown in FIG. 1, a closing plate 162 is provided on the opening end side of the gear box 52 opposite to the leg plate 16. The closing plate 162 is integrally attached to the gear box 52 by fastening means such as bolts and screws (not shown). The closing plate 162 attached to the gear box 52 closes the opening of the gear box 52 on the side opposite to the leg plate 16 and regulates the dropout of the two-stage gears 60, 70, 80 and the input gear 92 (clutch 90). ing. Further, the closing plate 162 attached to the gear box 52 not only closes the opening of the gear box 52 but also closes the side of the input gear 92 that houses the connecting pawl 110 and the return spring 126, The dropping of the connecting pawl 110 and the return spring 126 from the inside of the gear 92 is restricted.

  Further, a through hole 164 that penetrates the closing plate 162 in the thickness direction is formed in the closing plate 162, and the above-described small-diameter shaft portion 166 passes through the through hole 164 and protrudes to the outside of the closing plate 162. A spring housing 172 is provided outside the closing plate 162 (on the opposite side of the closing plate 162 from the gear box 52).

  The spring housing 172 is integrally connected to the gear box 52. The small-diameter shaft portion 166 that has passed through the through hole 164 enters the inside of the spring housing 172 and is rotatably supported by a bearing portion (not shown) formed in the spring housing 172. The spring housing 172 houses a spiral spring (not shown). The end of the spiral spring on the outer side in the spiral direction is directly or indirectly locked to the spring housing 172, and the end on the inner side in the spiral direction is directly or indirectly locked to the small-diameter shaft portion 166 entering the spring housing 172. ing.

  The spiral spring is tightened when the small-diameter shaft portion 166 rotates in the drawing direction, and urges the small-diameter shaft portion 166 in the winding direction. When the webbing 20 drawn out from the spool 18 is wound and stored in the spool 18 in a normal state, the spool 18 is rotated in the winding direction by the urging force of the spiral spring.

<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.

  In this webbing retractor 10, when the ECU determines that the distance to another vehicle traveling in front of the vehicle or an obstacle in front of the vehicle is less than a certain value based on the electrical signal output from the front monitoring device. The ECU activates the motor 40 by energizing the motor 40. When the output shaft 42 is rotated by operating the motor 40, the gear 56 provided on the output shaft 42 transmits the rotation of the output shaft 42 to the large-diameter gear 62 of the two-stage gear 60 to rotate the two-stage gear 60. Further, since the small-diameter gear 64 of the two-stage gear 60 meshes with the large-diameter gear 72 of the two-stage gear 70, the rotation of the two-stage gear 60 is transmitted to the two-stage gear 70 and the two-stage gear 70 rotates. The rotation of the two-stage gear 70 is transmitted to the gear 80 meshing with the small-diameter gear 74, and further transmitted to the gear unit 100 meshing with the gear 80 at a reduced speed, whereby the input gear 92 rotates in the winding direction.

  As the input gear 92 rotates in the winding direction, the support shaft 102 formed on the bottom wall portion 94 of the input gear 92 rotates in the winding direction, and thereby the connecting pawl 110 supported by the support shaft 102. Rotates together with the input gear 92 in the winding direction. Here, as described above, the interference portion 152 of the interference piece 140 in the initial state is located on the winding direction side of the meshing portion 122 constituting the connection pawl 110, so the connection pawl 110 together with the input gear 92 is located. Rotates in the winding direction, the meshing portion 122 comes into contact with the interference portion 152 and presses the interference portion 152 in the winding direction.

  The interference piece 140 enters between the outer holding ring 146 and the inner holding ring 148 in a state where the base 142 is curved against its own elasticity, and presses against the outer holding ring 146 and the inner holding ring 148. For this reason, if the base 142 is not pressed by a force exceeding the maximum static frictional force at the contact portion between the base 142 and the outer holding ring 146 and the contact portion between the base 142 and the inner holding ring 148, the base 142 is held outside. There is no movement in the circumferential direction between the ring 146 and the inner retaining ring 148.

  For this reason, in this state, the meshing portion 122 of the connecting pawl 110 receives the pressing reaction force from the interference portion 152 of the interference piece 140 and rotates around the support shaft 102 against the urging force of the return spring 126 to mesh. The part 122 approaches the outer periphery of the ratchet gear 114. When each coupling pawl 110 rotates as described above, as shown in FIG. 4, when the meshing portion 122 of one coupling pawl 110 meshes with the ratchet teeth of the ratchet gear 114, the meshing portion 122 is engaged with the ratchet gear 114. The ratchet teeth are pressed in the winding direction.

  Further, in this state, since the connection pawl 110 is restricted from further rotation, the meshing part 122 of the connection pawl 110 continues to press the interference part 152 of the interference piece 140, thereby the interference part 152 of the interference piece 140. When the pressing force applied in the winding direction exceeds the maximum static frictional force at the contact portion between the base portion 142 and the outer holding ring 146 and the contact portion between the base portion 142 and the inner holding ring 148, the interference piece 140 is held outside. It is guided by the ring 146 and the inner holding ring 148 and rotates in the winding direction.

  As a result, the input gear 92 further rotates in the winding direction, and the rotation of the input gear 92 in the winding direction is transmitted to the ratchet gear 114 via the coupling pawl 110 to rotate the ratchet gear 114 in the winding direction. When the ratchet gear 114 rotates in the winding direction and the engagement hole 134 of the ratchet gear 114 presses the engaging portion 132 in the winding direction, the coil portion of the coil spring 130 rotates in the winding direction. The inner side of the coil portion of the coil spring 130 is in pressure contact (contact) with the outer peripheral portion of the large-diameter shaft portion 184 of the adapter 182.

  For this reason, when the coil portion of the coil spring 130 rotates in the winding direction, the adapter 182 rotates in the winding direction due to friction between the coil portion of the coil spring 130 and the outer peripheral portion of the large-diameter shaft portion 184 of the adapter 182. . Thus, when the adapter 182 rotates in the winding direction, the spool 18 rotates in the winding direction, and when the spool 18 rotates in the winding direction, the webbing 20 is wound around the spool 18, and the vehicle occupant A slight slack of the webbing 20 attached to the body, so-called “slack” is removed.

  As described above, in the present embodiment, the rotational force in the winding direction of the ratchet gear 114 due to the driving force of the motor 40 is transmitted to the adapter 182 via the coil spring 130 and rotates the spool 18 in the winding direction. is there. When the spool 18 cannot take up the webbing 20 any more in the driving state of the motor 40 (that is, when the rotation of the spool 18 in the winding direction is restricted), the coil spring 130 together with the ratchet gear 114 is used. The coil portion of the coil rotates in the winding direction.

  In this state, if the adapter 182 does not rotate in the winding direction, the coil portion of the coil spring 130 is loosened by friction with the large-diameter shaft portion 184 (that is, the inner and outer diameter dimensions of the coil portion of the coil spring 130). To be elastically deformed. As a result, as shown in FIG. 5, the pressure contact between the coil portion of the coil spring 130 and the large-diameter shaft portion 184 of the adapter 182 is loosened, and the coil portion of the coil spring 130 and the large-diameter shaft portion 184 of the adapter 182 The coil spring 130 rotates relative to the adapter 182 so as to slide in the winding direction. As a result, transmission of rotational force from the ratchet gear 114 to the adapter 182 in the winding direction can be cut off or reduced, and the spool 18 can be further wound in a state where the rotation of the spool 18 in the winding direction is restricted. Rotation in the direction can be prevented or suppressed.

  Further, when the occupant wearing the webbing 20 moves inertially toward the front of the vehicle with the motor 40 driven as described above, the webbing 20 is pulled and the spool 18 rotates in the pull-out direction opposite to the winding direction. To do. In such a case, when the adapter 182 is rotated in the pull-out direction (that is, the direction opposite to the predetermined direction) by the spool 18, the coil portion of the coil spring 130 is loosened by the friction with the adapter 182 as described above. Elastically deforms. Thereby, it can prevent or suppress that a big load acts on the teeth of each gear train, such as the two-stage gears 60 and 70 of the driving force transmission mechanism 50 on the motor 40 side from the ratchet gear 114. Thereby, it is not necessary to set the mechanical strength of each gear constituting the driving force transmission mechanism 50 to be particularly high, and it is possible to reduce the size and weight.

  Here, as described above, when the winding of the coil portion of the coil spring 130 with respect to the large-diameter shaft portion 184 is loosened, the outer peripheral side of the coil portion of the coil spring 130 is in pressure contact with the inner peripheral portion of the cylindrical portion. Therefore, in this state, friction between the outer peripheral portion of the large-diameter shaft portion 184 and the coil portion of the coil spring 130 is reduced, but friction is generated between the inner peripheral portion of the cylindrical portion 186 and the coil portion of the coil spring 130. Arise. Therefore, when the ratchet gear 114 rotates relative to the adapter 182 in the winding direction, the friction between the outer peripheral portion of the large-diameter shaft portion 184 and the coil portion of the coil spring 130 and the inner peripheral portion of the cylindrical portion 186 The ratchet gear 114 cannot rotate in the winding direction unless a rotational force exceeding the friction is applied between the coil spring 130 and the coil portion of the coil spring 130.

  In this way, the rotational force (load) required for the ratchet gear 114 to start relative rotation with respect to the adapter 182 in the winding direction can be increased.

  Further, as described above, when the ratchet gear 114 is rotating relative to the adapter 182 in the winding direction, the coil portion of the coil spring 130 is loosened and the friction with the large-diameter shaft portion 184 of the adapter 182 is lost. Is just getting smaller. For this reason, even when the ratchet gear 114 is rotating relative to the adapter 182 in the winding direction, no impact sound due to the elasticity of the coil spring 130 is generated.

  Further, in the present embodiment, the adapter 182 is provided with the coil spring 130, and the coil spring 130 is loosened (elastically deformed) so that the rotational force in the winding direction from the ratchet gear 114 to the adapter 182 is transmitted. This configuration prevents or suppresses transmission of rotational force in the pull-out direction from 182 to the ratchet gear 114. In such a configuration, the gear train (that is, the two-stage gear 60 or the like) constituting the driving force transmission mechanism 50 is on the motor 40 side with respect to the ratchet. For this reason, it is possible to prevent or suppress an unnecessarily large load from acting on all the gears constituting the gear train of the driving force transmission mechanism 50.

  In the present embodiment, the outer peripheral shape of the large-diameter shaft portion 184 as the first pressure contact portion is circular. However, the outer peripheral shape of the first pressure contact portion is not limited to a circular shape, for example, a cross section The shape may be a polygon such as a hexagon or a non-circular shape such as an ellipse. However, the outer peripheral shape of the first pressure contact portion is circular like the large-diameter shaft portion 184 so that the coil portion of the coil spring 130 is uniformly pressed against the outer peripheral portion of the large-diameter shaft portion 184. For this reason, the friction between the coil portion of the coil spring 130 along the circumferential direction of the large-diameter shaft portion 184 and the large-diameter shaft portion 184 can be increased and stabilized.

  Further, in the present embodiment, the inner peripheral shape of the cylindrical portion 186 as the second pressed contact portion is circular, but the inner peripheral shape of the second pressed contact portion is not limited to a circular shape, for example, The cross-sectional shape may be a polygon such as a hexagon or a non-circular shape such as an ellipse. However, by making the inner peripheral shape of the second pressure contact portion circular like the cylindrical portion 186, when the coil portion of the coil spring 130 is expanded in diameter, the coil portion of the coil spring 130 is inside the cylindrical portion 186. Press evenly around the circumference. For this reason, the friction between the coil part of the coil spring 130 along the circumferential direction of the cylindrical part 186 and the cylindrical part 186 can be increased and stabilized.

  Moreover, in this Embodiment, it was the structure which formed the adapter 182 as a spool side rotary body in the 1st to-be-contacted contact part and the 2nd to-be-contacted contact part. However, the first pressure contact portion and the second pressure contact portion are formed in the ratchet gear 114 as the motor-side rotating body, and an engagement hole or the like for engaging the engagement portion 132 of the coil spring 130 is formed in the adapter 182. It is good also as a structure.

  Furthermore, in the present embodiment, the large-diameter shaft portion 184 is used as the first pressure contact portion, and the cylindrical portion 186 is used as the second pressure contact portion. However, after the ratchet gear 114 is rotated relative to the adapter 182 in the winding direction, the coil portion of the coil spring 130 is reduced in diameter, and the large-diameter shaft portion 184 is used as a second pressure contact portion to form a cylindrical shape. The portion 186 may be the first pressed contact portion.

  A configuration in which the coil portion of the coil spring 130 is in pressure contact with the outside of the coil spring 130 is a cylindrical portion 186. However, the configuration in which the coil portion of the coil spring 130 is in pressure contact with the outside of the coil spring 130 may be a rib that is in pressure contact with only a portion of the coil portion of the coil spring 130 along the circumferential direction.

10 Webbing take-up device 18 Spool 20 Webbing 40 Motor 114 Ratchet gear (motor side rotating body)
130 Coil spring (rotation transmission member)
182 Adapter (Spool side rotating body)
184 Large diameter shaft (first pressed contact)
186 Cylindrical part (second pressure contact part)

Claims (5)

A spool that winds up the webbing by locking the longitudinal base end side of the webbing and rotating in one winding direction around the axis;
A spool-side rotating body that is provided integrally with the spool or is directly or indirectly connected to the spool and transmits rotation in a predetermined direction to the spool to rotate the spool in the winding direction;
A motor,
A motor-side rotating body that rotates in the predetermined direction when the driving force of the motor is transmitted;
A first pressure contact portion provided on one of the spool-side rotating body and the motor-side rotating body;
A second pressure contact portion provided on the one rotating body;
A part of the spool-side rotator and the motor-side rotator are engaged with each other and rotate together with the other rotator, and another part different from the part is rotated by the biasing force. 1 Rotates the motor-side rotator by contacting the pressure-contact portion and transmits the rotation of the motor-side rotator to the spool-side rotator, and the motor-side rotator rotates relative to the spool-side rotator in the predetermined direction. A rotation transmission member that loosens the pressure contact with the first pressure contact portion,
The rotation transmission member is provided on the one rotating body so that the rotation transmission member can be pressed by loosening the pressure transmission of the rotation transmission member with respect to the first pressure contact portion. A second pressure contact portion for applying the load to the load required for relative rotation of the rotation transmitting member with respect to the one rotating body;
A webbing take-up device comprising:   One end is engaged with the other rotating body, the other end side is formed in a coil shape, the first pressure contact portion is provided on one of the inner side and the outer side of the coil portion, and the coil portion is The first pressure contact portion is pressed against the first pressure contact portion, and the second pressure contact portion is provided on the inner side and the outer side of the coil portion so that the pressure contact with the first pressure contact portion is loosened and separated from the first pressure contact portion. 2. The webbing take-up device according to claim 1, wherein the rotation transmission member is a coil spring that press-contacts the second pressed contact portion by expanding or reducing the diameter of the coil portion.   One pressure contact portion of the first pressure contact portion and the second pressure contact portion is formed in a cylindrical shape in which the axial direction is along the axial direction of the one rotating body and the coil spring is provided inside. In addition, the other pressure contact portion of the first pressure contact portion and the second pressure contact portion is provided inside the coil spring, and an axial direction is a columnar shape along the axial direction of the one rotating body. Or the webbing winding device according to claim 2 formed in the shape of a cylinder.   The webbing take-up device according to claim 3, wherein the one pressed contact portion is formed in a cylindrical shape having a circular inner peripheral surface.   The webbing take-up device according to claim 3 or 4, wherein the other pressed contact portion is formed in a columnar shape or a cylindrical shape whose outer peripheral surface is circular.

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