JP2019112003A - Pretensioner, retractor and seat belt device - Google Patents

Abstract

To provide a pretensioner, a retractor and a seat belt device by which movement of a power transmission member in a reverse direction can be suppressed even if a ring gear is stopped in the state the ring gear is engaged with the power transmission member.SOLUTION: A retractor 1 includes a spool 2 which performs winding of a webbing for arresting a crewman, and a pretensioner 3 which winds the webbing and removes looseness of the webbing in the case of emergency. The pretensioner 3 includes a ring gear 31 which is connected to the spool 2, and a power transmission device 32 which transmits power to the ring gear 31 in the case of emergency. The power transmission device 32 includes a rod-like power transmission member 32a which transmits power to the ring gear 31 while being plastically deformed. The ring gear 31 includes a first engagement tooth 31a which has a relatively shallow depth of bite into the power transmission member 32a, and a second engagement tooth 31b which has a relatively deep depth of bite into the power transmission member 32a.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a pretensioner, a retractor and a seat belt device, and more particularly to a pretensioner, a retractor and a seat belt device suitable for a configuration including a rod-like power transmission member.

  2. Description of the Related Art In a vehicle such as an automobile, a seat belt device for restraining an occupant on a seat provided with a seat on which the occupant sits and a backrest located on the back of the occupant is generally provided. The seat belt device includes a webbing for restraining an occupant, a retractor for winding the webbing, a buckle disposed on the side of the seat, and a tongue disposed on the webbing, and the tongue is fitted to the buckle. Restrains the occupant on the seat by webbing. In addition, it has become common for the retractor to have a pretensioner that removes slack of the webbing in an emergency such as a vehicle collision (see, for example, Patent Document 1).

  In Patent Document 1, a webbing capable of restraining an occupant of a vehicle and a biting portion are provided, and a rotating member (both a driving wheel or a ring gear) whose restraining force by the webbing is increased by being rotated is provided. And a moving member (also referred to as a power transmission member) for rotating the rotating member by biting of the biting portion by being moved, and provided on the opposite side of the rotating direction of the biting portion, There is disclosed a pretensioner mechanism including a friction surface having a coefficient of friction increased relative to a surface on the rotational direction side of the biting portion.

JP, 2014-201155, A

  According to the invention described in Patent Document 1 described above, the power transmission member rotates the ring gear because the friction surface having a large coefficient of friction is provided on the side opposite to the rotation direction of the biting portion of the ring gear. In this case, the power transmission member can be prevented from sliding outward in the radial direction of the ring gear with respect to the friction surface, and the moving force of the power transmission member can be efficiently transmitted to the ring gear.

  However, the biting portion of the ring gear not only plays the role of transmitting the moving force of the power transmission member to the spool but also the tension in the webbing pull-out direction when the ring gear is stopped in a state engaged with the power transmission member. The role of resisting against movement of the power transmission member in the opposite direction (not pushed back) is also required. From this point of view, the invention described in Patent Document 1 has a problem that sufficient drag can not be exhibited.

  The present invention has been made in view of such problems, and can suppress the movement of the power transmission member in the reverse direction even when the ring gear is stopped in a state engaged with the power transmission member. An object of the present invention is to provide a pretensioner, a retractor and a seat belt device.

  According to the present invention, in the pretensioner including a ring gear connected to a spool for winding a webbing for restraining an occupant, and a power transmission device for transmitting power to the ring gear in an emergency, the power transmission device And a rod-like power transmission member for transmitting power to the ring gear while plastically deforming, the ring gear having a first engagement tooth relative to the power transmission member and having a relatively small depth of biting into the power transmission member; There is provided a pretensioner comprising: a second engagement tooth having a deep bite into the power transmission member.

  Further, according to the present invention, in the retractor including a spool for taking up the webbing for restraining the occupant and a pretensioner for taking up the webbing to remove slack in an emergency, the pretensioner is mounted on the spool. And a power transmission device for transmitting power to the ring gear in an emergency, wherein the power transmission device is a rod-like power transmission member for transmitting power to the ring gear while being plastically deformed. And the ring gear includes a first engagement tooth having a relatively small biting depth to the power transmission member and a second engagement tooth having a relatively large biting depth to the power transmission member. A retractor is provided, characterized in that it comprises.

  Further, according to the present invention, in a seat belt device including a webbing for restraining an occupant and a retractor for taking up the webbing, the retractor includes a ring gear connected to the spool, and the ring in an emergency And a power transmission device for transmitting power to a gear, wherein the power transmission device includes a rod-like power transmission member for transmitting power to the ring gear while being plastically deformed, and the ring gear is relatively relatively A seat belt device comprising: a first engagement tooth having a shallow biting depth to a power transmission member; and a second engagement tooth having a relatively deep biting depth to the power transmission member. Is provided.

  In the above-described pretensioner, retractor, and seat belt device, the rotation radius of the second engagement teeth may be larger than the rotation radius of the first engagement teeth.

  Further, the plurality of second engagement teeth are arranged at regular intervals along the outer periphery of the ring gear, and the first engagement teeth are regularly spaced between adjacent second engagement teeth. A plurality of may be arranged.

  In addition, the ring gear is configured by a plurality of thin gears disposed coaxially adjacent to each other, and the plurality of thin gears include a first thin gear including the first engagement tooth and the second engagement tooth. And a second thin gear including the first engaging tooth and the second engaging tooth arranged in the same cycle as the first thin gear.

  Furthermore, the first thin gear and the second thin gear may be arranged such that the positions of the second engagement teeth are aligned, or are arranged such that the positions of the second engagement teeth are uneven. It may be

  In addition, the ring gear is configured by a plurality of thin gears disposed coaxially adjacent to each other, and the plurality of thin gears include a first thin gear including the first engagement tooth and the second engagement tooth. And a third thin gear including only the first engagement teeth.

  Furthermore, the ring gear may include a plurality of the first thin gears or may include a plurality of the third thin gears.

  According to the pretensioner, the retractor, and the seat belt device according to the present invention described above, the engagement force with the power transmission member can be improved by the second engagement teeth of the ring gear biting deeply into the power transmission member. Even when the ring gear is stopped in a state engaged with the power transmission member, high resistance can be generated by the second engagement teeth, and the movement of the power transmission member in the reverse direction can be suppressed. .

  In addition to the second engagement teeth, the ring gear is provided with the first engagement teeth having a smaller biting depth to the power transmission member than the second engagement teeth. The resistance to the movement of the power transmission member can be reduced.

It is a components development view showing the Retractor concerning one embodiment of the present invention. It is an enlarged view of a ring gear, (A) is a front view, (B) is a perspective view. It is sectional drawing which shows the state before the action | operation of a pre-tensioner. It is sectional drawing which shows the initial state after the action | operation start of a pre-tensioner. It is sectional drawing which shows the intermediate state after the action | operation start of a pre-tensioner. It is a figure which shows the modification of a ring gear, (A) is a front view of the first modification, (B) is a perspective view of the first modification, (C) is a front view of the second modification, (D) These are perspective views of a 2nd modification. It is a figure which shows the modification of a ring gear, (A) is a front view of the 3rd modification, (B) is a perspective view of the 3rd modification, (C) is a front view of the 4th modification, (D) These are perspective views of a 4th modification. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram which shows the seat belt apparatus which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8. Here, FIG. 1 is a component development view showing a retractor according to an embodiment of the present invention. FIG. 2 is an enlarged view of the ring gear, in which (A) is a front view and (B) is a perspective view. FIG. 3 is a cross-sectional view showing the pretensioner before actuation.

  A retractor 1 according to an embodiment of the present invention, as shown in FIGS. 1 to 3, includes a spool 2 for winding webbing for restraining an occupant, and a pretensioner for winding webbing in an emergency to remove slack. And 3, the pretensioner 3 includes a ring gear 31 connected to the spool 2 and a power transmission device 32 for transmitting power to the ring gear 31 in an emergency, and the power transmission device 32 is plastically deformed The ring gear 31 includes a rod-like power transmission member 32a for transmitting power to the ring gear 31, and the ring gear 31 is relatively motive power relative to the first engagement teeth 31a having a relatively low biting depth to the power transmission member 32a. And a second engagement tooth 31b having a deep bite into the transmission member 32a. In FIG. 1, the illustration of the webbing is omitted.

  The spool 2 is a winding drum for winding webbing, and is rotatably accommodated in a base frame 11 forming a frame of the retractor 1. The base frame 11 has, for example, a pair of end surfaces 111 and 112 facing each other, and a side surface 113 connecting the end surfaces. The base frame 11 may be provided with a tie plate 114 connected to the side surface 113 and the end surface 111, 112. Further, for example, the spring unit 4 is disposed on the end surface 111 side, and the pretensioner 3 and the lock mechanism 5 are disposed on the end surface 112 side. The arrangement of the spring unit 4, the pretensioner 3, the lock mechanism 5 and the like is not limited to the illustrated configuration.

  Further, an opening 111a for inserting the shaft of the spool 2 is formed in the end face 111 of the base frame 11, and an end face 112 of the base frame 11 is engaged with a pawl (not shown) of the locking mechanism 5. An opening 112a is formed having possible internal teeth. Further, inside the end surface 112 of the base frame 11, a part of the pretensioner 3 (for example, the ring gear 31 or the like) is disposed. Further, the lock mechanism 5 is disposed outside the end surface 112 of the base frame 11, and the lock mechanism 5 is accommodated in the retainer cover 51.

  The retainer cover 51 may be provided with a vehicle sensor 6 for detecting rapid deceleration or inclination of the vehicle body. The vehicle sensor 6 has, for example, a spherical mass and a sensor lever that is swung by the movement of the mass. The vehicle sensor 6 is fitted in and fixed to an opening 112 b formed in the end surface 112 of the base frame 11.

  The spool 2 may have a hollow at the center and a torsion bar 21 forming an axial center may be inserted therethrough. The torsion bar 21 is connected to the locking base 52 of the locking mechanism 5 whose first end is connected to the end of the spool 2 and whose second end is connected to the spring core of the spring unit 4. Therefore, the spool 2 is connected to the spring unit 4 via the locking base 52 and the torsion bar 21 and biased in the direction to wind up the webbing by the spring spring stored in the spring unit 4.

  The first end of the torsion bar 21 may be connected to the spool 2 without the locking base 52. Further, the means for applying the winding force to the spool 2 is not limited to the spring unit 4 and may be another means using an electric motor or the like.

  The locking base 52 is provided with a pawl arranged to be able to protrude and retract from its side portion. At the time of operation of the lock mechanism 5, the pawl is made to project from the side surface portion of the locking base 52 to engage with the internal teeth formed in the opening 112a of the base frame 11, thereby restraining the rotation of the locking base 52 in the webbing pull-out direction. Do.

  Therefore, even if a load is applied in the webbing pull-out direction in a state where the lock mechanism 5 is actuated, the spool 2 can be held in a non-rotational state until a load equal to or greater than a threshold is generated on the torsion bar 21 it can. When a load equal to or greater than the threshold value is generated on the torsion bar 21, the torsion bar 21 is twisted, causing the spool 2 to relatively rotate, and the webbing is pulled out.

  The lock mechanism 5 also includes a lock gear 53 disposed to be adjacent to the locking base 52. The lock gear 53 is provided with a flywheel (not shown) disposed swingably, and when the webbing is faster than the normal drawing speed, the flywheel is swung to be formed on the retainer cover 51. Engage with the internal teeth (not shown). When the vehicle sensor 6 is actuated, the sensor lever engages with the external teeth formed on the side surface of the lock gear 53.

  Thus, the lock gear 53 is restricted in rotation by the actuation of the flywheel or the vehicle sensor 6. Then, when the rotation of the lock gear 53 is restricted, relative rotation occurs between the locking base 52 and the lock gear 53, and the pawl is protruded from the side surface portion of the locking base 52 along with the relative rotation.

  The lock mechanism 5 is not limited to the illustrated configuration, and various configurations existing conventionally can be arbitrarily selected and used. Further, the spool 2 may have an impact absorbing mechanism constituted by a combination of a shaft and a plastic deformation member in the form of a wire or a plate instead of the torsion bar 21.

  The pretensioner 3 includes, for example, a ring gear 31 disposed coaxially with the spool 2, a power transmission device 32 for rotating the ring gear 31, a pretensioner cover 33 for storing the ring gear 31, and a power transmission member 32a. A guide spacer 34 forming a moving space, and a guide block 35 disposed at a meshing start portion of the ring gear 31 and the power transmission member 32a are provided.

  The pretensioner cover 33 is disposed inside the end surface 112 of the base frame 11, and the guide spacer 34 is accommodated in the pretensioner cover 33. The ring gear 31 is disposed so as to be located in the space between the pretensioner cover 33 secured by the guide spacer 34 and the end surface 112. The ring gear 31 may be referred to as a drive wheel or a rotating member.

  The ring gear 31 is fixed to, for example, the shaft portion of the locking base 52. As shown in FIG. 2A, the ring gear 31 is formed at a central portion with a plurality of first engagement teeth 31a and second engagement teeth 31b formed to project radially outward. And an opening 31c. The opening 31 c is inserted into the shaft of the locking base 52. The shape of the opening 31 c is formed to conform to the shape of the shaft of the locking base 52, and is not limited to the illustrated hexagonal shape.

  As shown by a dashed dotted line in FIG. 2A, the rotation radius Rb of the second engagement tooth 31b is set larger than the rotation radius Ra of the first engagement tooth 31a. The difference in the radius of rotation causes a difference in the biting depth with respect to the power transmission member 32a, and the biting depth of the second engagement tooth 31b becomes deeper than the biting depth of the first engagement tooth 31a, and the first engagement The biting depth of the teeth 31a is shallower than the biting depth of the second engagement teeth 31b.

  In addition, a plurality of second engagement teeth 31 b are arranged at regular intervals along the outer periphery of the ring gear 31. For example, in the embodiment shown in FIG. 2 (A), six second engagement teeth 31b are evenly arranged at intervals of the central angle α (here, 60 °). A plurality of first engagement teeth 31a are arranged at regular intervals between adjacent second engagement teeth 31b. For example, in the embodiment shown in FIG. 2 (A), two first engagement teeth 31a are equally disposed at intervals of a central angle β (here 20 °) between one second engagement teeth 31b. ing.

  That is, a total of 18 first engaging teeth 31a and second engaging teeth 31b are equally disposed at intervals of a central angle of 20 °, and the second engaging teeth 31b having a large rotation radius at every central angle of 60 °. Are placed intermittently. In other words, the second engagement teeth 31 b are arranged at a rate of one in three. The number and ratio of the first engagement teeth 31a and the second engagement teeth 31b are arbitrary, and are not limited to the illustrated configuration.

  Moreover, although the case where it has two types of engagement teeth (The 1st engagement tooth 31a and the 2nd engagement tooth 31b) from which the biting depth differs in this embodiment is explained, ring gear 31 is biting depth There may be three or more types of engaging teeth different in length.

  The power transmission device 32 includes, for example, a rod-shaped power transmission member 32a that transmits power to the ring gear 31 while plastically deforming, a pipe 32b that accommodates the power transmission member 32a, and a gas disposed at an end of the pipe 32b. A generator 32c and a piston 32d sliding in the pipe 32b are provided. The power transmission member 32a has, for example, an elongated shape (rod shape) made of resin, and is accommodated in the pipe 32b.

  The pipe 32 b is disposed at a position where the front end faces the ring gear 31, and the rear end side is extended by the length necessary for the movement of the power transmission member 32 a so that it curves along the outer shape of the retractor 1 Is formed. As shown in FIG. 1, an opening 32 e is formed in a part of the outer periphery of the pipe 32 b, and the power transmission member 32 a is released into the pretensioner cover 33 from the opening 32 e.

  Further, as shown in FIG. 3, the guide block 35 is inserted into the end of the pipe 32b, and the ends of the guide block 35 and the pipe 32b are fixed to the side surface 113 of the base frame 11 by the fixing pins 36. There is. The guide block 35 has an inclined surface 35a for guiding the movement of the power transmission member 32a, and a main body 35b fixed to the base frame 11 (side surface 113).

  As shown in FIG. 1, the guide block 35 has a columnar shape that can be inserted into the end of the pipe 32b, and an inclined surface 35a is formed on the end face thereof. The guide block 35 is a component for guiding the tip end of the power transmission member 32 a to collide with the ring gear 31 when the pretensioner 3 is actuated. The inclined surface 35a may be a flat surface or a curved surface as long as it can guide the power transmission member 32a.

  The guide block 35 is also a component that receives an impact generated when the power transmission member 32 a collides with the ring gear 31. Therefore, the guide block 35 may be made of resin or metal as long as it has a strength that can withstand the load generated when the power transmission member 32 a collides with the ring gear 31.

  The guide block 35 is fixed to the base frame 11 having high strength by the fixing pin 36. Therefore, the power transmission member 32a can be guided to the ring gear 31 without being displaced without being deformed or displaced when the pretensioner 3 is actuated.

  Although the present embodiment describes the case where the pretensioner 3 includes the guide block 35, the pretensioner 3 according to the present embodiment may be applied to a conventional pretensioner that does not have the guide block 35. it can.

  Here, the operation of the pretensioner 3 will be described with reference to FIGS. 3 to 5. FIG. 4 is a cross-sectional view showing an initial state after actuation of the pretensioner. FIG. 5 is a cross-sectional view showing an intermediate state after the start of operation of the pretensioner.

  At normal times before actuation of the pretensioner 3, as shown in FIG. 3, the state in which the power transmission member 32a is accommodated in the pipe 32b is maintained. Then, in an emergency such as a vehicle collision (when the pretensioner 3 is activated), the power transmission member 32a is pushed out in the pipe 32b by the gas supplied by the gas generator 32c.

  The power transmission member 32a pushed out in the pipe 32b moves along the inclined surface 35a of the guide block 35 as shown in FIG. 4, and the first engagement teeth 31a or the second engagement teeth 31b of the ring gear 31 are moved. To clash.

  Thereafter, as shown in FIG. 5, the power transmission member 32a is pushed out to the space (passage) formed by the pretensioner cover 33 and the guide spacer 34, and the first engagement teeth 31a and the second engagement of the ring gear 31 are engaged. It moves along the passage while engaging with the cog 31b. At this time, it is preferable that about four to five engagement teeth bite into the power transmission member 32a. Therefore, it is preferable to arrange the second engagement teeth 31b at a rate of one or more in five.

  Then, the power transmission member 32a finally stops by colliding with the stopper surface 34a formed by the guide spacer 34 or by taking up the slack of the webbing. Now, it is assumed that the power transmission member 32a has stopped in the state shown in FIG. 5 after the pretensioner 3 has finished winding up the webbing.

  At this time, the first engagement teeth 31a have a biting depth Da, and the second engagement teeth 31b have a biting depth Db. In the present embodiment, there is a relationship of biting depth Db> biting depth Da. That is, the biting depth Da of the first engagement teeth 31a is relatively shallow with respect to the biting depth Db of the second engagement teeth 31b, and the biting depth Db of the second engagement teeth 31b is the first engagement. It is set so as to be relatively deep with respect to the biting depth Da of the teeth 31a.

  According to the pretensioner 3, the second engagement teeth 31b of the ring gear 31 bite deeply into the power transmission member 32a, whereby the engagement force with the power transmission member 32a can be improved, and the ring gear 31 transmits power. Even when stopping in a state engaged with the member 32a, high resistance can be generated by the second engagement teeth 31b, and the movement of the power transmission member 32a in the reverse direction can be suppressed.

  In addition to the second engagement teeth 31b, the ring gear 31 is provided with the first engagement teeth 31a having a biting depth to the power transmission member 32a smaller than that of the second engagement teeth 31b. The resistance to the movement of the power transmission member 32a when the tensioner 3 is actuated can be reduced.

  Next, modifications of the ring gear 31 will be described with reference to FIGS. 6 (A) to 7 (D). Here, FIG. 6 is a view showing a modification of the ring gear, in which (A) is a front view of the first modification, (B) is a perspective view of the first modification, and (C) is a second modification (D) is a perspective view of the second modified example. FIG. 7 is a view showing a modification of the ring gear, in which (A) is a front view of the third modification, (B) is a perspective view of the third modification, and (C) is a front view of the fourth modification , (D) is a perspective view of a fourth modification.

  The ring gear 31 according to the first modification shown in FIGS. 6 (A) and 6 (B) comprises two thin-walled gears (the first thin-walled gear 311 and the second thin-walled gear) coaxially arranged adjacent to each other 312), the first thin gear 311 includes a first engagement tooth 31a and a second engagement tooth 31b, and the second thin gear 312 is arranged in the same cycle as the first thin gear 311. It includes one engagement tooth 31a and a second engagement tooth 31b. The first thin gear 311 and the second thin gear 312 are arranged such that the positions of the second engagement teeth 31 b are aligned.

  As described above, by forming the ring gear 31 with the thin first thin gear 311 and the second thin gear 312, the ring gear 31 can be easily manufactured, and the thickness of the ring gear 31 can be any number of thin gears. Can be adjusted. Here, although the ring gear 31 is configured by two thin gears (the first thin gear 311 and the second thin gear 312), the ring gear may be configured by three or more thin gears.

  Similar to the ring gear 31 of the first modification, the ring gear 31 according to the second modification shown in FIGS. 6C and 6D includes two thin gears (the first thin gear 311 and the second thin gear The second engaging gear 31 b is disposed so that the positions of the second engaging teeth 31 b become irregular. In the first thin gear 311 and the second thin gear 312 of the second modification, the first thin gear 311 and the second thin gear 312 shown in the first modification and the first engagement teeth 31 a and the second engagement are used. The arrangement of the teeth 31b is different.

  Specifically, in the first thin gear 311 and the second thin gear 312 of the second modification, the first engagement teeth 31 a and the second engagement teeth 31 b are equally spaced at an interval of the central angle β (20 °). A total of 18 teeth are disposed, and second engagement teeth 31b having a large turning radius are intermittently disposed at every central angle α (120 °). In other words, the second engagement teeth 31 b are arranged at a rate of one in six.

  Then, the first thin gear 311 is placed so that the first engagement teeth 31 a located in the middle between the second engagement teeth 31 b of the first thin gear 311 and the second engagement teeth 31 b of the second thin gear 312 overlap. And the second thin gear 312 is disposed. Also with this configuration, as in the ring gear 31 of the first modified example, the second engagement teeth 31 b can be disposed at every 60 ° of the ring gear 31 as a whole, and substantially the same effect is exhibited.

  In this manner, the second engagement teeth 31b of the ring gear 31 are shifted by displacing the positions of the second engagement teeth 31b of the first thin-walled gear 311 and the second thin-walled gear 312 so that the positions become uneven. The pressure receiving area on the power transmission member 32a at the disposed position can be reduced.

  Therefore, depending on the conditions of the pretensioner 3 and the material of the power transmission member 32a, the ring gear 31 according to the first modification or the ring gear 31 according to the second modification may be used. The pressure receiving area by the 31 second engaging teeth 31 b can be adjusted.

  The ring gear 31 according to the third modification shown in FIGS. 7 (A) and 7 (B) comprises three thin-walled gears (first thin-walled gear 311, second thin-walled gear) coaxially arranged adjacent to each other. 312 and the third thin gear 313), the first thin gear 311 and the second thin gear 312 include the first engagement teeth 31a and the second engagement teeth 31b, and the third thin gear 313 is the first Only the engagement teeth 31a are included.

  The first thin gear 311 and the second thin gear 312 have the same shape, and the first engagement teeth 31 a and the second engagement teeth 31 b have a total of 18 evenly at intervals of the central angle β (20 °). The second engaging teeth 31 b having a large rotation radius are intermittently disposed at every central angle α (60 °). On the other hand, in the third thin gears 313, only the first engagement teeth 31a having a small rotation radius Ra are equally arranged at intervals of the central angle β (20 °).

  Then, as shown in FIG. 7B, the third thin gear 313 is disposed so as to be sandwiched between the first thin gear 311 and the second thin gear 312. Therefore, the second engagement teeth 31 b of the first thin gear 311 and the second thin gear 312 and the first engagement teeth 31 a of the third thin gear 313 overlap at every central angle of 60 °.

  Thus, the thin-walled gear (the first thin-walled gear 311 and the second thin-walled gear 312) including the second engagement teeth 31b and the thin-walled gear (third thin-walled gear 313) not including the second engagement teeth 31b are combined Also by this, it is possible to adjust the pressure receiving area of the ring gear 31 to the power transmission member 32a. Although not shown, the first thin gear 311 and the second thin gear 312 may have the same configuration as the second modification shown in FIGS. 6 (C) and 6 (D).

  Although not shown, three thin-walled gears including the second engagement teeth 31b are prepared, two thin-walled gears not including the second engagement teeth 31b are prepared, and the thin-walled gears including the second engagement teeth 31b A thin gear not including the second engagement teeth 31 b may be disposed between the two.

  In addition, in the ring gear 31 of the 3rd modification mentioned above, since the 1st thin film gear 311 and the 2nd thin film gear 312 have the same shape, the two 1st thin film gears 311 are provided. In other words.

  The ring gear 31 according to the fourth modification shown in FIGS. 7 (C) and 7 (D) is formed by three thin gears (axially thin gear 311, third thin gear) coaxially arranged adjacent to each other. 313 and the fourth thin gear 314), the first thin gear 311 includes the first engagement teeth 31a and the second engagement teeth 31b, and the third thin gear 313 and the fourth thin gear 314 are the first Only the engagement teeth 31a are included.

  A total of 18 first engagement teeth 31a and second engagement teeth 31b of the first thin-walled gear 311 are equally disposed at intervals of the central angle β (20 °), and every central angle α (60 °) The second engagement teeth 31 b having a large rotation radius are intermittently disposed. On the other hand, the third thin gear 313 and the fourth thin gear 314 have the same shape, and only the first engagement teeth 31a having a small rotation radius Ra are equal at intervals of the central angle β (20 °). There are 18 in the

  Then, as shown in FIG. 7D, the first thin gear 311 is disposed so as to be sandwiched between the third thin gear 313 and the fourth thin gear 314. Therefore, the second engagement teeth 31b of the first thin gear 311 and the first engagement teeth 31a of the third thin gear 313 and the fourth thin gear 314 overlap at every central angle of 60 °.

  Thus, the thin-walled gear (first thin-walled gear 311) including the second engagement teeth 31b and the thin-walled gears (third thin-walled gear 313 and the fourth thin-walled gear 314) not including the second engagement teeth 31b are combined. Also by this, it is possible to adjust the pressure receiving area of the ring gear 31 to the power transmission member 32a.

  Although not shown, two thin-walled gears including the second engagement teeth 31b are prepared, three thin-walled gears not including the second engagement teeth 31b are prepared, and a thin-walled gear not including the second engagement teeth 31b A thin-walled gear including the second engagement teeth 31b may be disposed between the two. Furthermore, the two thin-walled gears including the second engagement teeth 31 b may have the same configuration as the second modification shown in FIGS. 6 (C) and 6 (D).

  In the ring gear 31 according to the fourth modification described above, the third thin gear 313 and the fourth thin gear 314 have the same shape, and therefore, two third thin gears 313 are provided. In other words.

  Next, a seat belt device according to an embodiment of the present invention will be described with reference to FIG. Here, FIG. 8 is a whole block diagram which shows the seat belt apparatus based on embodiment of this invention. In FIG. 8, for convenience of explanation, components other than the seat belt device are illustrated by alternate long and short dashed lines.

  The seat belt device 100 according to the present embodiment shown in FIG. 8 includes a webbing W for restraining an occupant, a retractor 1 for winding the webbing W, and a guide anchor 101 provided on the vehicle body side for guiding the webbing W. The retractor 1 has, for example, the configuration shown in FIG. 1, including a belt anchor 102 for fixing the webbing W to the vehicle body side, a buckle 103 disposed on the side of the seat S, and a tongue 104 disposed on the webbing W. have.

  Hereinafter, components other than the retractor 1 will be briefly described. The seat S includes, for example, a seat S1 on which an occupant sits, a backrest S2 located on the back of the occupant, and a headrest S3 supporting the head of the occupant. The retractor 1 is built in, for example, a B pillar P of a vehicle body. In general, the buckle 103 is often disposed on the side surface of the seating portion S1, and the belt anchor 102 is often disposed on the lower surface of the seating portion S1. In addition, the guide anchor 101 is often disposed on the B-pillar P. The webbing W has one end connected to the belt anchor 102 and the other end connected to the retractor 1 via the guide anchor 101.

  Therefore, when the tongue 104 is fitted to the buckle 103, the webbing W is pulled out from the retractor 1 while sliding on the insertion hole of the guide anchor 101. When the occupant wears the seat belt or releases the seat belt at the time of getting off, the webbing W is wound up by the action of the spring unit 4 of the retractor 1 until a certain load is applied.

  The seat belt device 100 mentioned above applies the retractor 1 which concerns on embodiment mentioned above to the normal seat belt apparatus in a front seat. Therefore, according to the seat belt device 100 according to the present embodiment, the engagement force with the power transmission member 32a can be improved by the second engagement teeth 31b of the ring gear 31 biting deeply into the power transmission member 32a. Even when the ring gear 31 is stopped in a state engaged with the power transmission member 32a, high resistance can be generated by the second engagement teeth 31b, and the movement of the power transmission member 32a in the reverse direction can be It can be suppressed.

  In addition, the seatbelt apparatus 100 which concerns on this embodiment is not limited to application to a front seat, For example, the guide anchor 101 is abbreviate | omitted and it can apply easily also to a rear seat. Moreover, the seat belt apparatus 100 which concerns on this embodiment can be used also for vehicles other than a vehicle.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Retractor 2 Spool 3 Pretensioner 4 Spring unit 5 Locking mechanism 6 Vehicle sensor 11 Base frame 21 Torsion bar 31 Ring gear 31a First engagement tooth 31b Second engagement tooth 31c Opening 32 Power transmission 32a Power transmission member 32b Pipe 32c Gas generator 32d Piston 32e Opening 33 Pretensioner cover 34 Guide spacer 34a Stopper surface 35 Guide block 35a Slope 35b Main body 36 Fixing pin 51 Retainer cover 52 Locking base 53 Lock gear 100 Seat belt device 101 Guide anchor 102 Belt anchor 103 Buckles 104 Tongs 111 and 112 Ends 111a and 112b Openings 113 Sides 114 Tension 311 First thin gear 312 Second thin gear 313 Third thin gear A 314 fourth thin gear

Claims (9)

A pretensioner, comprising: a ring gear connected to a spool for winding a webbing for restraining an occupant; and a power transmission device for transmitting power to the ring gear in an emergency,
The power transmission device includes a rod-like power transmission member that transmits power to the ring gear while being plastically deformed.
The ring gear includes a first engagement tooth relatively biting in the power transmission member and a second engagement tooth relatively deep in the power transmission member. Yes,
A pretensioner characterized by   The pretensioner according to claim 1, wherein a rotation radius of the second engagement tooth is larger than a rotation radius of the first engagement tooth.   The plurality of second engagement teeth are arranged at a constant interval along the outer periphery of the ring gear, and the plurality of first engagement teeth are at a constant interval between adjacent second engagement teeth. The pretensioner according to claim 1, characterized in that it is arranged.   The ring gear is constituted by a plurality of thin gears disposed coaxially adjacent to each other, and the plurality of thin gears include a first thin gear including the first engagement tooth and the second engagement tooth; The pretensioner according to claim 1, further comprising: a second thin gear including the first engaging tooth and the second engaging tooth arranged in the same cycle as the first thin gear.   The first thin gear and the second thin gear are disposed such that the positions of the second engagement teeth are aligned, or are disposed such that the positions of the second engagement teeth are uneven. A pretensioner according to claim 4, characterized in that.   The ring gear is constituted by a plurality of thin gears disposed coaxially adjacent to each other, and the plurality of thin gears include a first thin gear including the first engagement tooth and the second engagement tooth; The pretensioner according to claim 1, further comprising: a third thin gear including only the first engagement teeth.   7. The pretensioner according to claim 6, wherein the ring gear comprises a plurality of the first thin gears or comprises a plurality of the third thin gears. In a retractor including a spool for taking up webbing for restraining an occupant, and a pretensioner for taking up the webbing in an emergency to remove slack.
The retractor according to any one of claims 1 to 7, wherein the pretensioner is a pretensioner according to any one of claims 1 to 7. In a seat belt device including a webbing for restraining an occupant and a retractor for taking up the webbing,
A seat belt device comprising the pretensioner according to any one of claims 1 to 7, wherein the retractor is provided.