Webbing winding device

Abstract

This webbing winding device comprises a spool, a rotating member, and a first moving member that rotates the spool in a winding direction via the rotating member. Inside a cylinder, a second moving member is provided. The cylinder is provided with a stop part that stops the movement of the second moving member moving inside the cylinder. Between the second moving member and the stop part, a cushion part is provided. By an increase in the pressure inside the cylinder, the second moving member is caused to move toward the rotating member side together with the first moving member. In a state in which the cushion part is sandwiched between the stop part and the second moving member, the movement of the second moving member toward the rotating member side is stopped.

Description

Webbing retractor

[0001] The present disclosure relates to a webbing take-up device.

[0002] Japanese Patent Application Laid-Open Publication No. 2019-206285 discloses a webbing take-up device (retractor) that can retract webbing onto a spool by operating a power transmission device. This power transmission device includes a ring gear that rotates with the spool, a rod-shaped power transmission member that transmits power to the ring gear while plastically deforming, a pipe-shaped pressure vessel that guides the power transmission member to the ring gear, a sealing member disposed rearward of the power transmission member, a piston disposed rearward of the sealing member, and a gas generator disposed at the rear end of the pressure vessel. The pressure vessel has a reduced-diameter portion at its tip that has a smaller inner diameter than the rest of the pressure vessel. When the sealing member collides with the reduced-diameter portion, it stops while undergoing plastic deformation.

[0003] Incidentally, in a configuration such as the webbing retractor described in JP 2019-206285 A, in which a first moving member (power transmission member) is moved together with a second moving member (sealing member) and the movement of the second moving member is stopped by a part of a cylinder (pressure vessel), it is considered desirable to suppress deformation of the second moving member and the cylinder when the movement of the second moving member is stopped, but the configuration described in JP 2019-206285 A does not take this point into consideration.

[0004] The present disclosure provides a webbing take-up device that can suppress deformation of the second moving member and the cylinder when the movement of the second moving member is stopped.

[0005] A webbing take-up device of a first aspect includes a spool that is rotated in a take-up direction to take up the webbing; a rotating member that is rotatable together with the spool and has a plurality of teeth arranged in a circumferential direction of rotation; and a first moving member that is provided inside a cylindrically shaped cylinder and is moved from inside the cylinder toward the rotating member as the pressure inside the cylinder increases, and is further moved while the teeth of the rotating member are engaged, thereby rotating the spool in the take-up direction via the rotating member. A second moving member is provided inside the cylinder, and the cylinder is provided with a stop portion that stops the movement of the second moving member moving inside the cylinder, and a cushion portion is provided between the second moving member and the stop portion, and as the pressure inside the cylinder increases, the second moving member is moved toward the rotating member together with the first moving member, and with the cushion portion sandwiched between the stop portion and the second moving member, the movement of the second moving member toward the rotating member is stopped.

[0006] The webbing retractor of the second aspect is the webbing retractor of the first aspect, wherein the cushion portion is provided between the second moving member and the first moving member inside the cylinder, and when the pressure inside the cylinder increases, the second moving member is moved together with the cushion portion and the first moving member toward the rotating member.

[0007] The webbing retractor of the third aspect is the webbing retractor of the second aspect, wherein a recess into which the second moving member fits is formed at the end of the cushion portion on the second moving member side, and when the pressure inside the cylinder increases and the second moving member is moved toward the cushion portion, the second moving member pushes open the recess and the cushion portion is pressed against the inner surface of the cylinder.

[0008] A webbing take-up device of a fourth aspect is the webbing take-up device of the first aspect, wherein the cushion portion is engaged with the stop portion.

[0009] The webbing take-up device of the fifth aspect is the webbing take-up device of the fourth aspect, wherein the gap between the stop portion and the first moving member is maintained at a constant gap by having the cushion portion.

[0010] A webbing retractor of a sixth aspect is the webbing retractor of the first, fourth or fifth aspect, wherein the cushion portion is attached to the cylinder from the outside of the cylinder, and the cushion portion comprises an outer fitting portion that fits into the outer peripheral surface of the cylinder, and a cushion portion main body that extends from the outer fitting portion, and the cushion portion main body is in contact with the outer peripheral surface of the first moving member while inserted into an opening formed in the cylinder from the outside of the cylinder.

[0011] In the webbing take-up device of the first aspect, an increase in pressure inside the cylinder causes the second moving member to move together with the first moving member toward the rotating member. When the first moving member is further moved while the teeth of the rotating member are engaged with the first moving member, the first moving member rotates the spool in the winding direction via the rotating member. This causes the webbing to be wound onto the spool. In this webbing take-up device of the first aspect, the movement of the second moving member toward the rotating member is stopped when the cushion portion is sandwiched between the stop portion and the second moving member. Thus, by interposing the cushion portion between the stop portion and the second moving member, deformation of the second moving member and the cylinder when the movement of the second moving member is stopped can be suppressed.

[0012] In the webbing take-up device of the second aspect, the cushion portion is provided between the second moving member and the first moving member inside the cylinder. Then, when the pressure inside the cylinder increases, the second moving member is moved together with the cushion portion and the first moving member toward the rotating member. In this way, in the webbing take-up device of the second aspect, the cushion portion can be moved inside the cylinder.

[0013] In the webbing take-up device of the third aspect, when the pressure inside the cylinder increases and the second moving member is moved toward the cushion portion, the second moving member widens the recess, thereby pressing the cushion portion against the inner surface of the cylinder.

[0014] In the webbing take-up device of the fourth aspect, the cushion portion is engaged with the stop portion. In this configuration, a configuration can be adopted in which the cushion portion is not moved inside the cylinder.

[0015] In the webbing take-up device of the fifth aspect, the cushion portion is provided to maintain a constant distance between the stop portion and the first moving member, thereby preventing or suppressing resistance caused by sliding of the first moving member against the stop portion.

[0016] In the webbing take-up device of the sixth aspect, the cushion main body is in contact with the outer peripheral surface of the first moving member, so that the gap between the stop portion and the outer peripheral surface of the first moving member is maintained at a constant gap, thereby making it possible to prevent or suppress resistance caused by the first moving member sliding against the stop portion.

[0017] This is a view of the webbing winding device according to this embodiment as seen from the outside in the vehicle width direction. This is a view of the webbing winding device in FIG. 1 as seen from the front side of the vehicle. This is a cross-sectional view showing the main part of the pretensioner. This is a cross-sectional view showing the main part of the pretensioner and shows the state immediately after the MGG is actuated. This is a cross-sectional view showing the main part of the pretensioner when a time has elapsed from FIG. 4. This is a cross-sectional view showing the main part of the pretensioner and shows the state where the movement of the stopper is stopped. This is a side view showing a stop portion of another form. This is a view of the stop portion shown in FIG. 7 as seen from the open end side of the cylinder. This is a side view showing a stop portion of another form. This is a view of the stop portion shown in FIG. 9 as seen from the open end side of the cylinder. This is a cross-sectional view showing a stop portion of another form. This is a cross-sectional view showing a stop portion of another form. This is a cross-sectional view for explaining the effect by adopting the stop portion shown in FIG. 12. This is a perspective view showing a cushion member of another form. This is a perspective view showing a cushion member of another form. This is a perspective view showing a cushion member of another form. This is a perspective view showing a cushion member of another form. This is a perspective view showing a cushion member of another form. This is a perspective view showing a cushion member of another form. This is a perspective view showing a cushion member of another form. This is a cross-sectional view showing the cushion member and the cylinder shown in FIG. 20 and shows the state when the cushion member contacts the stop portion. This is a cross-sectional view showing the cushion member and the cylinder shown in FIG. 20 and shows the state when the cushion member contacts the stop portion. This is a cross-sectional view showing a cushion member of another form. This is a cross-sectional view showing a cushion member of another form. This is a cross-sectional view showing the main part of the pretensioner of the second embodiment. This is a perspective view showing the open end side of the cylinder. This is a cross-sectional view showing a cross-section obtained by cutting the open end side of the cylinder and the cushion member along the radial direction of the cylinder. This is a cross-sectional view showing the main part of the pretensioner of the second embodiment and shows the state where the movement of the stopper is stopped. This is a cross-sectional view corresponding to FIG. 27 showing the open end side of the cylinder and the cushion member of another form. This is a cross-sectional view corresponding to FIG. 27 showing the open end side of the cylinder and the cushion member of another form. This is a cross-sectional view corresponding to FIG. 27 showing the open end side of the cylinder and the cushion member of another form. This is a cross-sectional view corresponding to FIG. 27 showing the open end side of the cylinder and the cushion member of another form.Fig. 28 is a cross-sectional view corresponding to Fig. 27, showing the open end side of the cylinder and the cushion member of another embodiment. Fig. 29 is a cross-sectional view showing the main part of a pretensioner of a third embodiment. Fig. 30 is a cross-sectional view showing the main part of a pretensioner of a fourth embodiment.

[0018] 1 to 6, a webbing take-up device according to an embodiment of the present disclosure will be described. In each drawing, arrow FR indicates the front side of a vehicle to which the webbing take-up device 10 according to this embodiment is applied, arrow OUT indicates the outer side in the vehicle width direction, and arrow UP indicates the upper side of the vehicle. In each drawing, arrow A indicates the take-up direction, which is the rotation direction of the spool 14 when the spool 14 takes up the webbing 16, and arrow B indicates the unwinding direction, which is opposite to the take-up direction.

[0019] 1 is used as part of a seat belt device for a vehicle, and includes a frame 12. The frame 12 is fixed to a part of the vehicle body.

[0020] A spool 14 is also provided on the frame 12. The spool 14 is formed in a substantially cylindrical shape and is rotatable about a central axis (in the directions of arrows A and B). A base end portion of a long, strip-shaped webbing 16 in the longitudinal direction is engaged with the spool 14, and when the spool 14 rotates in the winding direction (in the direction of arrow A), the webbing 16 is wound onto the spool 14 from the base end side in the longitudinal direction. The tip side of the webbing 16 in the longitudinal direction extends from the spool 14 toward the upper side of the vehicle and is folded back toward the lower side of the vehicle through a slit hole formed in a through anchor (not shown) supported on the vehicle body, for example.

[0021] Furthermore, a longitudinal end portion of the webbing 16 is anchored to an anchor plate (not shown). The anchor plate is formed of a metal plate such as iron, and is fixed to a floor portion (not shown) of the vehicle or a frame member of a seat (not shown) corresponding to the webbing retractor 10.

[0022] A seat belt device for a vehicle to which the webbing retractor 10 is applied also includes a buckle device (not shown). The buckle device is provided on the inner side in the vehicle width direction of a seat (not shown) to which the webbing retractor 10 is applied. With the webbing 16 wrapped around the body of an occupant seated in the seat, a tongue (not shown) provided on the webbing 16 engages with the buckle device, thereby fastening the webbing 16 to the body of the occupant.

[0023] 1, a spring housing 18 is provided on the vehicle rear side of the frame 12. A spool biasing means (not shown), such as a power spring, is provided inside the spring housing 18. The spool biasing means is directly or indirectly engaged with the spool 14, and the spool 14 is biased in the winding direction (direction of arrow A) by the biasing force of the spool biasing means.

[0024] Meanwhile, a cover plate 20 is fixed to the front side of the vehicle of the frame 12. Part of a locking mechanism (not shown) that locks the rotation of the spool 14 in the pull-out direction and part of a pretensioner 30 (described later) are provided inside the cover plate 20.

[0025] A sensor holder 24 is fixed to the front side of the vehicle of the cover plate 20 via a connecting member 22. A sensor (not shown) that detects a vehicle emergency state is housed inside the sensor holder 24. The locking mechanism is configured to limit rotation of the spool 14 in the pull-out direction in the event of a vehicle emergency based on the detection result of the sensor.

[0026] The pretensioner 30 is a mechanism that removes slack in the webbing 16 worn by an occupant by forcibly rotating the spool 14 in the winding direction in the event of a vehicle emergency. The pretensioner 30 includes a rotating member (sometimes referred to as a "pinion") 32 shown in FIG. 2 inside the cover plate 20. Note that in FIG. 2, some of the components provided inside the container-shaped portion of the cover plate 20 are simplified and shown by dotted lines. The rotating member 32 is provided to be rotatable integrally with the spool 14 (see FIG. 1). A plurality of teeth 32A are provided circumferentially spaced apart on the outer periphery of the rotating member 32. When the rotating member 32 rotates to one side (the same direction as the arrow A in FIG. 2), the spool 14 (see FIG. 1) rotates in the winding direction.

[0027] As shown in FIGS. 2 and 3, the pretensioner 30 includes a cylindrical cylinder 40, a micro gas generator 50 (see FIG. 1), and a resin rack 34, a stopper 35, a seal ball 36, and a cushion member 37 provided inside the cylinder 40.

[0028] The cylinder 40 is formed, for example, using a round metal pipe. A micro gas generator 50 is attached to one end of the cylinder 40. The micro gas generator 50 is electrically connected to a collision detection sensor (not shown) provided in the vehicle via an ECU (controller). The micro gas generator 50 is activated and generates gas when the collision detection sensor detects an impact during a vehicle collision. Gas from the micro gas generator 50 is supplied into the cylinder 40.

[0029] The other end of the cylinder 40 is disposed on the upper rear side of the frame 12, with its open end facing the outer periphery of the rotating member 32. As shown in Fig. 3, the other end of the cylinder 40 is provided with a stopper 38, part of which has a smaller inner diameter than the other part. The inner diameter of this stopper 38 is set to be equal to or larger than the outer diameter of a resin rack 34 (described later) and smaller than the outer diameter of a stopper 35.

[0030] The resin rack 34 serving as the first moving member is formed in an elongated shape using a resin material, and has a circular cross section cut along a direction perpendicular to the longitudinal direction. As shown in Figures 2 and 3, most of the resin rack 34 is disposed inside the cylinder 40. A portion of the resin rack 34 protrudes from the other end of the cylinder 40 and is disposed opposite the outer periphery of the rotating member 32.

[0031] 3, the stopper 35 serving as the second moving member is formed in a spherical shape using a metal material, for example, and is disposed on the micro gas generator 50 (see FIG. 1) side with respect to the resin rack 34.

[0032] The seal ball 36 is formed in a spherical shape using, for example, a resin material, and is disposed on the micro gas generator 50 (see FIG. 1) side of the stopper 35.

[0033] The cushion member 37 serving as the cushion section is formed, for example, using a resin material. The cushion member 37 is disposed between the resin rack 34 and the stopper 35. More specifically, the cushion member 37 is formed in a cylindrical shape with its axial direction facing the stopper 35. The end of the cushion member 37 on the stopper 35 side is formed with a recess 37A into which the stopper 35 fits, with the stopper 35 side being open. The shape of the space inside the recess 37A is a cone shape that gradually narrows as it approaches the axial center of the stopper 35.

[0034] (Operations and Effects of the Present Embodiment) Next, operations and effects of the present embodiment will be described.

[0035] As shown in Figures 1, 2, and 3, in the webbing take-up device 10 of this embodiment, when the micro gas generator 50 is activated in the event of a vehicle collision, which is one aspect of a vehicle emergency, high-pressure gas is instantaneously supplied from the micro gas generator 50 to the inside of the cylinder 40.

[0036] 1, 2, and 3, when high-pressure gas is supplied from the micro gas generator 50 to the inside of the cylinder 40, the seal ball 36 is crushed, causing the seal ball 36 to come into close contact with the inner circumferential surface of the cylinder 40, and the seal ball 36 presses the resin rack 34 via the stopper 35 and the cushion member 37. As a result, the stopper 35, the cushion member 37, and the resin rack 34 are moved toward the rotating member 32, as shown in FIGS.

[0037] When the resin rack 34 is moved toward the rotating member 32, the resin rack 34 engages with the teeth 32A of the rotating member 32 (the teeth 32A of the rotating member 32 bite into the lateral sides of the resin rack 34). Then, when the resin rack 34 is further moved while the teeth 32A of the rotating member 32 are engaged with the resin rack 34, the resin rack 34 rotates the spool 14 in the winding direction via the rotating member 32. As a result, the webbing 16 is wound onto the spool 14, and slack in the webbing 16 worn by the occupant is removed.

[0038] 1, 2, and 6, when the stopper 35, cushion member 37, and resin rack 34 are moved toward the rotating member 32, an outer circumferential portion 37B of the end of the cushion member 37 on the stopper 35 side is sandwiched between the stopping portion 38 and the stopper 35, and the movement of the stopper 35 toward the rotating member 32 is stopped. This prevents or suppresses gas from leaking from the other end of the cylinder 40. Here, in the present embodiment, by interposing the cushion member 37, which functions as a buffer material, between the stopping portion 38 and the stopper 35, deformation of the stopper 35 and the cylinder 40 when the movement of the stopper 35 is stopped can be suppressed.

[0039] 5 and 6 , in this embodiment, when the pressure inside the cylinder 40 increases and the stopper 35 moves toward the cushion member 37, the stopper 35 expands the recess 37A. This allows the outer periphery 37B of the end of the cushion member 37 on the stopper 35 side to be pressed against the inner surface of the cylinder 40. This allows the outer periphery 37B of the end of the cushion member 37 on the stopper 35 side to be more reliably sandwiched between the stopping portion 38 and the stopper 35.

[0040] In the present embodiment, an example has been described in which the cushion member 37 and the resin rack 34 are separate bodies, but the present disclosure is not limited to this. For example, a configuration may be adopted in which a cushion portion that functions similarly to the cushion member 37 is provided integrally with the resin rack 34.

[0041] 7 and 8, the stop portions 38 may be formed all around the circumference of the cylinder 40. As shown in Figures 9 and 10, the stop portions 38 may be formed at several locations along the circumference of the cylinder 40. In the example shown in Figures 9 and 10, three stop portions 38 are provided, and the three stop portions 38 are arranged at equal intervals along the circumference of the cylinder 40.

[0042] 11 and 12, it is also possible to employ a configuration in which the axial dimension of the stop portion 38 is larger than that of the configuration shown in Fig. 3 etc. In particular, in the example shown in Fig. 12, in which the stop portion 38 is provided over the open end of the other end of the cylinder 40, the inner peripheral surface of the stop portion 38 can function as a guide surface for the resin rack 34. This makes it possible to stabilize the movement trajectory of the resin rack 34 when it moves from the other end of the cylinder 40 toward the rotating member 32 (see Fig. 2), as shown in Fig. 13 (it is possible to reduce variation in the angle dimension θ shown in Fig. 13).

[0043] 14 and 15, the cushion member 37 may have a cylindrical shape (a shape that does not have the recess 37A shown in FIG. 3). Note that the axial dimension of the cushion member 37 shown in FIG. 15 is set to be larger than the axial dimension of the cushion member 37 shown in FIG. 14.

[0044] 16 to 19, the shape of the internal space of the recess 37A formed in the cushion member 37 may be semispherical. The configuration of the cushion member 37 shown in Fig. 16 is the same as that of the cushion member 37 shown in Fig. 3, except that the shape of the internal space of the recess 37A and the dimension in the axial direction are different.

[0045] 17, the outer diameter of the cushion member 37 gradually decreases toward the side opposite to the stopper 35 (see FIG. 3), thereby giving the cushion member 37 a truncated cone shape.

[0046] 18, the outer diameter of a portion 37C on the stopper 35 (see FIG. 3) side gradually decreases toward the opposite side from the stopper 35, and the outer peripheral surface of the portion 37C is spherical. The portion 37D on the opposite side from the stopper 35 is formed in a cylindrical shape, and the outer diameter of the portion 37D on the opposite side from the stopper 35 is smaller than the outer diameter of the portion 37C on the stopper 35 side.

[0047] 19, the outer diameter of a portion 37C on the stopper 35 (see FIG. 3) side gradually decreases toward the opposite side from the stopper 35, and the shape of this portion 37C is a truncated cone. Furthermore, a portion 37D on the opposite side from the stopper 35 is formed in a cylindrical shape, and the outer diameter of the portion 37D on the opposite side from the stopper 35 is smaller than the outer diameter of the portion 37C on the stopper 35 side.

[0048] 20 and 21, a cushion member 37 may be provided with a recess 37A at the end opposite the stopper 35 (see FIG. 3). In this cushion member 37, a portion 37C on the stopper 35 (see FIG. 3) side is formed in a cylindrical shape. Furthermore, a portion 37D opposite the stopper 35 has an outer diameter that gradually increases toward the side opposite the stopper 35, and the shape of this portion 37D is a truncated cone. As shown in FIG. 22, in this cushion member 37, an outer periphery 37E at the end opposite the stopper 35 of the cushion member 37 contacts the stop portion 38, thereby expanding the outer periphery 37E at the end opposite the stopper 35 of the cushion member 37. This allows the cushion member 37 to more firmly contact the stop portion 38.

[0049] 23, a configuration can be employed in which recesses 37A are provided on both the end on the stopper 35 (see FIG. 3) side and the end opposite the stopper 35. With this configuration, it is possible to eliminate directionality when assembling the cushion member 37 inside the cylinder 40. This makes it possible to prevent or suppress incorrect assembly of the cushion member 37 inside the cylinder 40.

[0050] 24, a configuration may be adopted in which the strength of the portion forming the central portion 37F is increased relative to the surface portion 37G. For example, the central portion 37F of the cushion member 37 may be formed using a resin material containing glass fiber, and the surface portion 37G of the cushion member 37 may be formed using a resin material not containing glass fiber.

[0051] Second Embodiment Next, a pretensioner 60 according to a second embodiment will be described with reference to Figures 25 to 28. Note that the same reference numerals are used to designate the components and parts of the pretensioner 60 according to the second embodiment that correspond to those of the pretensioner 30, and descriptions thereof may be omitted.

[0052] 25, the stopper 35 of this embodiment is disposed between the seal ball 36 and the resin rack 34. The stopper 35 is formed in a cylindrical shape with its axial direction facing the seal ball 36 and the resin rack 34. The central portion of the stopper 35 in the axial direction forms a constricted portion 35A whose outer diameter is set smaller than the portions on both sides in the axial direction.

[0053] 25 and 26 , a rectangular opening 40A is formed in the cylinder 40 at a portion adjacent to the stop portion 38 and on the micro gas generator 50 (see FIG. 1) side of the stop portion 38. In this embodiment, two openings 40A are formed in the cylinder 40, and the two openings 40A are arranged at equal intervals along the circumferential direction of the cylinder 40. In addition, the edge of the opening 40A on the side opposite the micro gas generator 50 forms the stop portion 38.

[0054] As shown in Figures 25 and 27, a cushion member 37 is attached to the cylinder 40 from the outside of the cylinder 40. The cushion member 37 includes an outer fitting portion 37H that fits onto the outer peripheral surface of the cylinder 40 and two cushion body portions 37I that extend from the outer fitting portion 37H. The outer fitting portion 37H is curved to fit along the shape of the outer peripheral surface of the cylinder 40. The two cushion body portions 37I extend from both ends of the outer fitting portion 37H toward the axial center of the cylinder 40. The cushion member 37 is attached to the cylinder 40 with the two cushion body portions 37I inserted into the two openings 40A from the outside of the cylinder 40. When the cushion member 37 is attached to the cylinder 40, the two cushion body portions 37I are engaged with the edges that serve as stop portions 38 of the two openings 40A. Furthermore, when the cushion member 37 is attached to the cylinder 40, the end faces of the two cushion body parts 37I opposite to the outer fitting parts 37H are in contact with the outer peripheral surface of the resin rack 34. This maintains a constant distance between the stop parts 38 and the outer peripheral surface of the resin rack 34.

[0055] 28 , in the pretensioner 60 of this embodiment described above, when the stopper 35 and the resin rack 34 are moved toward the rotating member 32 (see FIG. 2 ), the two cushion portion main bodies 37I of the cushion member 37 are sandwiched between the stopping portions 38 and the stopper 35, stopping the movement of the stopper 35 toward the rotating member 32. In this way, in the pretensioner 60 of this embodiment, by interposing the cushion portion main bodies 37I of the cushion member 37, which function as buffer material, between the stopping portions 38 and the stopper 35, it is possible to suppress deformation of the stopper 35 and the cylinder 40 when the movement of the stopper 35 is stopped. Furthermore, the pretensioner 60 of this embodiment can employ a configuration that prevents the cushion member 37 from moving inside the cylinder 40.

[0056] Furthermore, in this embodiment, when the cushion member 37 is attached to the cylinder 40, the end faces of the two cushion body parts 37I opposite to the outer fitting parts 37H are in contact with the outer peripheral surface of the resin rack 34, thereby maintaining a constant distance between the stop parts 38 and the outer peripheral surface of the resin rack 34. With this configuration, it is possible to prevent or suppress resistance caused by the resin rack 34 sliding against the stop parts 38.

[0057] Although the present embodiment has been described as an example using a cylinder 40 having two openings 40A and a cushion member 37 having two cushion body parts 37I that are inserted into the two openings 40A, the present disclosure is not limited to this. For example, as shown in Fig. 29, a configuration may be adopted in which a cylinder 40 having three openings 40A and a cushion member 37 having three cushion body parts 37I that are inserted into the three openings 40A, respectively.

[0058] Furthermore, in the present embodiment and the example shown in FIG. 29 , an example using a cushion member 37 having a single outer fitting portion 37H has been described, but the present disclosure is not limited thereto. For example, as shown in FIGS. 30 and 31 , a configuration in which the outer fitting portion 37H is divided into a number corresponding to the number of cushion body portions 37I can be employed. Furthermore, as shown in FIGS. 32 and 33 , a configuration in which the outer fitting portion 37H fits over substantially the entire outer circumferential surface of the cylinder 40 can also be employed. Here, in the cushion member 37 shown in FIG. 33 , two of the outer fitting portion 37H are spring portions 37J. The force of the deformed spring portions 37J attempting to restore their original shape biases the outer fitting portion 37H toward the outer circumferential surface of the cylinder 40.

[0059] Third and Fourth Embodiments Next, a pretensioner 70 of a third embodiment and a pretensioner 80 of a fourth embodiment will be described using Figures 34 and 35. Note that members and parts of the pretensioner 70 of the third embodiment and the pretensioner 80 of the fourth embodiment that correspond to those of the pretensioners 30 and 60 described above will be assigned the same reference numerals as those corresponding to those of the pretensioners 30 and 60 described above, and descriptions thereof may be omitted.

[0060] 34 and 35 , in the pretensioner 70 of the third embodiment and the pretensioner 80 of the fourth embodiment, a second cylinder 90 is provided as a cylinder separate from the cylinder 40 on an extension line of the cylinder 40. The second cylinder 90 has a stop portion 38 whose inner and outer diameters are smaller than those of the cylinder 40. Here, in the pretensioner 70 of the third embodiment shown in FIG. 34 , the cushion member 37 is engaged with the end of the second cylinder 90 on the cylinder 40 side. Furthermore, in the pretensioner 80 of the fourth embodiment shown in FIG. 35 , the cushion member 37 is suspended between the first cylinder 40 and the second cylinder 90, and the cushion member 37 is engaged with the end of the first cylinder 40 on the second cylinder 90 side and the end of the second cylinder 90 on the cylinder 40 side.

[0061] 34 and 35 , in the pretensioner 70 of the third embodiment and the pretensioner 80 of the fourth embodiment described above, when the stopper 35 and the resin rack 34 are moved toward the rotating member 32 (see FIG. 2 ), the cushion portion main body 37I of the cushion member 37 is sandwiched between the stopping portion 38 and the stopper 35, and movement of the stopper 35 toward the rotating member 32 is stopped. In this way, in the pretensioners 70 and 80 of the present embodiment, the second cylinder 90, which is separate from the cylinder 40, is used as the stopping portion 38, and the cushion portion main body 37I of the cushion member 37, which functions as a buffer, is interposed between the stopping portion 38 and the stopper 35, thereby making it possible to suppress deformation of the stopper 35 and the cylinder 40 when movement of the stopper 35 is stopped.

[0062] In each of the above-described embodiments, an example has been described in which the seal ball 36 functioning as a sealing member is provided on the micro gas generator 50 side relative to the stopper 35, but the present disclosure is not limited to this. For example, the stopper 35 may be configured to have the sealing properties as a sealing member. For example, the stopper and the sealing member may be configured as an integrated unit. Furthermore, the sealing member does not have to be spherical like the seal ball 36.

[0063] The above describes one embodiment of the present disclosure, but the present disclosure is not limited to the above, and it goes without saying that it can be implemented in various other modified forms within the scope that does not deviate from the gist of the present disclosure.

[0064] The disclosure of Japanese Patent Application No. 2024-097556, filed on June 17, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A webbing take-up device comprising: a spool that is rotated in a winding direction to wind up a webbing; a rotating member that is rotatable together with the spool and has a plurality of teeth arranged circumferentially in the rotational direction; and a first moving member that is provided inside a cylindrical cylinder and is moved from inside the cylinder toward the rotating member as the pressure inside the cylinder increases, and is further moved with the teeth of the rotating member engaged, thereby rotating the spool in the winding direction via the rotating member; wherein a second moving member is provided inside the cylinder, and the cylinder is provided with a stop portion that stops the movement of the second moving member moving inside the cylinder, and a cushion portion is provided between the second moving member and the stop portion, and when the pressure inside the cylinder increases, the second moving member is moved toward the rotating member together with the first moving member, and when the cushion portion is sandwiched between the stop portion and the second moving member, the movement of the second moving member toward the rotating member is stopped.

2. A webbing take-up device as described in claim 1, wherein the cushion portion is provided between the second moving member and the first moving member inside the cylinder, and when the pressure inside the cylinder increases, the second moving member is moved together with the cushion portion and the first moving member towards the rotating member.

3. A webbing take-up device as described in claim 2, wherein a recess into which the second moving member fits is formed at the end of the cushion section on the side of the second moving member, and when the pressure inside the cylinder increases and the second moving member is moved towards the cushion section, the second moving member pushes open the recess and the cushion section is pressed against the inner surface of the cylinder.

4. A webbing take-up device as set forth in claim 1, wherein the cushion portion is engaged with the stop portion.

5. A webbing take-up device as set forth in claim 4, wherein the cushion portion is provided so that the gap between the stop portion and the first moving member is kept constant.

6. A webbing take-up device as described in claim 1, wherein the cushion portion is attached to the cylinder from the outside of the cylinder, and the cushion portion comprises an outer fitting portion that fits onto the outer peripheral surface of the cylinder, and a cushion portion main body that extends from the outer fitting portion, and the cushion portion main body is in contact with the outer peripheral surface of the first moving member when inserted into an opening formed in the cylinder from the outside of the cylinder.

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