Webbing winding device

Abstract

To provide a webbing winding device that is configured to rotate a rotating member using a moving member made of resin in a lengthy shape when an emergency arises on a vehicle, which enables the rotating member to appropriately engage with a member for power transmission at an initial stage during the emergency.SOLUTION: A rotating member 32 is connected to a spool to be rotatable integrally therewith when an emergency arises on a vehicle. A moving member 36 made of resin in a lengthy shape is moved towards a tip in an axial direction thereof to rotate the rotating member 32 towards one side. An engaging member 34 made of metal is provided at a tip side in the axial direction of the moving member 36. The engaging member 34 has a plurality of rack teeth 34A. One of the plurality of rack teeth 34A is arranged in contact with an outer tooth 32A of the rotating member 32, which is pushed by the moving member 36, so that the rack tooth 34A advances directly while engaging with the outer tooth 32A to rotate the rotating member 32 towards the one side.SELECTED DRAWING: Figure 2

Description

[[TECHNICAL FIELD]]

[0001] The present invention relates to a webbing take-up device in which a rotating member is rotated to one side and a spool is rotated in a take-up direction. [[BACKGROUND ART]]

[0002] In the seat belt device described in the following Patent Document 1, in an emergency, a rod-shaped power transmission member of a pretensioner transmits power to a ring gear while undergoing plastic deformation, thereby rotating the spool and winding webbing onto the spool. Further, in this seat belt device, a tip reinforcing member having higher strength than the power transmission member is disposed on the tip side of the power transmission member, and by causing the tip reinforcing member to collide with the ring gear first in the initial stage of driving the ring gear, chipping or damage to the power transmission member can be suppressed. [[PRIOR ART DOCUMENT]] [[PATENT DOCUMENT]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2016-37184 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] However, there is room for improvement in the meshing between the ring gear and the power transmission member in the initial stage of an emergency.

[0005] In view of the above facts, an object of the present invention is to provide a webbing take-up device which, in a configuration where a rotating member is rotated using an elongated resin-made moving member in a vehicle emergency, can achieve favorable meshing between the rotating member and the power transmission member in the initial stage of the emergency. [[Means for Solving the Problem]]

[0006] A webbing winding device according to a first aspect of the present invention comprises: a spool that is rotated in the winding direction to wind the webbing of a seat belt device; a rotating member having a plurality of first teeth formed on its outer circumference, which is connected to the spool so as to be rotatable together in the event of a vehicle emergency, and which rotates to one side while connected to the spool, thereby causing the spool to rotate in the winding direction; a resin moving member formed in an elongated shape, which is moved toward the axial end so that the first teeth engage with it, thereby rotating the rotating member toward the one side; and a metal engaging member provided toward the axial end of the moving member, which has a plurality of second teeth, with at least one of the plurality of second teeth in contact with the first teeth, and which, when pushed by the moving member, moves in a straight line while engaging with the first teeth, thereby rotating the rotating member toward the one side.

[0007] A webbing winding device according to a second aspect of the present invention is a webbing winding device according to a first aspect of the present invention, further comprising a receiving portion that receives the engaging member which has been moved by being pushed by the moving member, thereby separating the engaging member from the axial end of the moving member.

[0008] A third aspect of the present invention is a webbing winding device in the second aspect of the present invention, wherein the receiving portion is provided on the side of the meshing member in the straight-line direction when the meshing member rotates the rotating member toward the one side.

[0009] A fourth aspect of the present invention is a webbing winding device according to the second or third aspect of the present invention, wherein the end of the engaging member that is pressed by the moving member has a guide surface formed thereon that guides the moving member in a predetermined direction of travel when the engaging member is received by the receiving portion.

[0010] A fifth aspect of the present invention is a webbing winding device according to any one of the first to fourth aspects of the present invention, wherein the rotating member has a first rotating part and a second rotating part arranged in series in the direction of its central axis, the first rotating part has a plurality of meshing teeth on its outer circumference as part of the plurality of first teeth, and the second teeth are configured to mesh with the meshing teeth, the second rotating part has a plurality of biting teeth on its outer circumference as part of the other of the plurality of first teeth, and the biting teeth are configured to bite into the moving member, and further, a guide part is provided to guide the moving member from near the outer circumference of the first rotating part to the outer circumference of the second rotating part.

[0011] A webbing winding device according to a sixth aspect of the present invention is a webbing winding device according to a fifth aspect of the present invention, further comprising a receiving portion that receives the meshing member which has been moved by being pushed by the moving member, thereby separating the meshing member from the axial end of the moving member, the guide portion being formed on the end of the meshing member that is pushed by the moving member and serving as a guide surface that guides the moving member to the outer circumference of the second rotating portion when the meshing member is received by the receiving portion, and the second rotating portion being provided so as to be rotatable integrally with the first rotating portion and configured to rotate relative to the first rotating portion when the rotational load of the relative rotation of the second rotating portion with respect to the first rotating portion exceeds a predetermined value.

[0012] A webbing winding device according to the seventh aspect of the present invention is a webbing winding device according to the fifth or sixth aspect of the present invention, wherein the second rotating part is formed to have a larger diameter than the first rotating part. [Effects of the Invention]

[0013] In the webbing winding device of the first aspect of the present invention, a rotating member is connected to a spool so as to be able to rotate integrally with it in the event of a vehicle emergency. With the rotating member connected to the spool, a long, resin-made movable member is moved toward the axial end, and the first teeth of the rotating member bite into the movable member, causing the movable member to rotate the rotating member to one side, and the spool to rotate in the winding direction. As a result, the webbing of the seat belt device is wound onto the spool.

[0014] Here, a metal meshing member is provided on the axial end side of the movable member. This meshing member has multiple second teeth, and at least one of the multiple second teeth is positioned in contact with the first tooth. When this meshing member is pushed by the movable member, the second teeth of the meshing member mesh with the first tooth of the rotating member and rotate, causing the rotating member to rotate to one side. This ensures good meshing between the rotating member and the power transmission member in the initial stages of a vehicle emergency.

[0015] In the webbing winding device of the second aspect of the present invention, the engaging member is received by the receiving portion when it is pushed and moved by the moving member, and moves away from the axial end side of the moving member. This makes it possible to suppress the occurrence of malfunctions caused by the metal engaging member coming into contact with surrounding members in the path of the moving member.

[0016] In the webbing winding device according to the third aspect of the present invention, the receiving portion is provided on the side of the meshing member in the direction of linear movement when the meshing member rotates the rotating member to one side, so that the amount of movement of the meshing member can be minimized.

[0017] In the webbing winding device according to the fourth aspect of the present invention, when the engaging member is received by the receiving portion, the moving member is guided in a predetermined direction of travel by the guide surface of the engaging member. As a result, the moving member can be moved smoothly in a predetermined direction of travel.

[0018] In the fifth aspect of the webbing winding device of the present invention, when the meshing member is pressed by the moving member, the second teeth of the meshing member mesh with the meshing teeth (a portion of the multiple first teeth) of the first rotating portion of the rotating member, causing the rotating member to rotate to one side. The moving member is also guided by the guide portion from near the outer circumference of the first rotating portion to the outer circumference of the second rotating portion. When the moving member moves on the outer circumference of the second rotating portion, the bite teeth (another portion of the multiple first teeth) of the second rotating portion of the rotating member bite into the moving member, causing the moving member to rotate the rotating member to one side. In this fifth aspect of the webbing winding device of the present invention, the rotating member has separate portions for meshing with the second teeth of the meshing member and for biting into the moving member. This allows for good meshing between the rotating member and the meshing member in the initial stages of an emergency, while increasing the design freedom for rotating the rotating member by the movement of the moving member.

[0019] In the webbing winding device according to the sixth aspect of the present invention, the meshing member is received by the receiving portion when pushed and moved by the moving member, and moves away from the axial end side of the moving member. When the meshing member is received by the receiving portion, the moving member is guided by the guide surface of the meshing member toward the outer circumference of the second rotating portion. When the moving member moves toward the outer circumference of the second rotating portion, the biting teeth of the second rotating portion of the rotating member bite into the moving member, causing the moving member to attempt to rotate the second rotating portion of the rotating member toward one side. At this time, if the first rotating portion is unable to rotate because it is meshed with the second teeth of the meshing member received by the receiving portion, a rotational load of the relative rotation of the second rotating portion with respect to the first rotating portion acts on it, and when this rotational load exceeds a predetermined value, the second rotating portion rotates toward one side relative to the first rotating portion. In this way, the second rotating portion can be rotated by the moving member while the meshing member that meshes with the first rotating portion has the function of guiding the moving member.

[0020] In the webbing winding device according to the seventh aspect of the present invention, the second rotating part is formed with a larger diameter than the first rotating part, so that the rotating member can be rotated with less force compared to the case where the second rotating part has the same diameter as the first rotating part. [Brief explanation of the drawing]

[0021] [Figure 1]It is a rear view showing a webbing take-up device according to a first embodiment of the present invention as viewed from the vehicle width direction inner side. [Figure 2] It is a simplified side cross-sectional view showing the webbing take-up device of FIG. 1 as viewed from the vehicle front side. [Figure 3] It is a side cross-sectional view corresponding to FIG. 2 showing a state where a moving member has been moved. [Figure 4] It is a rear view showing a webbing take-up device according to a second embodiment of the present invention as viewed from the vehicle width direction inner side. [Figure 5] It is a simplified side cross-sectional view showing the webbing take-up device of FIG. 4 as viewed from the vehicle front side. [Figure 6] It is a rear view corresponding to FIG. 4 showing a state where a moving member has been moved. [Figure 7A] It is an exploded rear view showing a first modified example of a configuration for integrating a moving member and an engaging member. [Figure 7B] It is an exploded rear view showing a second modified example of a configuration for integrating a moving member and an engaging member. [Figure 7C] It is a rear view showing a third modified example of a configuration for integrating a moving member and an engaging member. [Figure 8] It is a simplified side cross-sectional view showing a webbing take-up device according to a modified example as viewed from the vehicle front side. MODE FOR CARRYING OUT THE INVENTION

[0022] [First Embodiment] A webbing take-up device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. In each drawing, arrow FR indicates the front side of a vehicle to which the webbing take-up device 10 of the present embodiment is applied, arrow OUT indicates the outer side in the vehicle width direction, and arrow UP indicates the upper side of the vehicle. Further, 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 pull-out direction opposite to the take-up direction.

[0023] <Configuration> The webbing winding device 10 according to this embodiment, shown in Figure 1, is part of a vehicle seat belt system and includes a frame 12. The frame 12 is fixed to the lower part of the vehicle's center pillar (not shown), which is part of the vehicle body.

[0024] Furthermore, a spool 14 is provided on the frame 12. The spool 14 is formed in a substantially cylindrical shape and is rotatable around its central axis (in the directions of arrows A and B). The longitudinal base end of a long, strip-shaped webbing 16 is locked to 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 longitudinal base end side. The longitudinal tip side of the webbing 16 extends from the spool 14 towards the upper side of the vehicle and is folded back towards the lower side of the vehicle through a slit hole formed in a through anchor (not shown) supported by the center pillar on the upper side of the frame 12.

[0025] Furthermore, the longitudinal end of the webbing 16 is secured to an anchor plate (not shown). The anchor plate is made of a metal plate such as iron and is fixed to the floor of the vehicle (not shown) or to a skeletal member of a sheet (not shown) corresponding to the webbing winding device 10.

[0026] Furthermore, the seat belt system for a vehicle to which the webbing winding device 10 is applied is equipped with a buckle device (not shown). The buckle device is located on the inside in the vehicle width direction of the seat (not shown) to which the webbing winding device 10 is applied. With the webbing 16 wrapped around the body of an occupant seated in the seat, the tongue (not shown) provided on the webbing 16 engages with the buckle device, thereby fastening the webbing 16 to the occupant's body.

[0027] Furthermore, as shown in Figure 1, a spring housing 18 is provided on the rear side of the frame 12. Inside the spring housing 18, a spool biasing means (not shown), such as a coil spring, is provided. 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.

[0028] On the other hand, a cover plate 20 is fixed to the front side of the frame 12. Part of a locking mechanism (not shown) and part of a pretensioner 30 are provided inside the cover plate 20. Note that in Figure 1, a part of the inside of the cover plate 20 is shown by cutting out a portion of the cover plate 20. A sensor holder 22 is fixed to the front side of the cover plate 20. The sensor holder 22 is formed in a container shape that opens towards the rear side of the vehicle. A sensor (not shown) for detecting an emergency state of the vehicle is housed inside the sensor holder 22. The locking mechanism is configured to restrict the rotation of the spool 14 in the pulling direction in the event of an emergency of the vehicle, based on the detection result of the sensor.

[0029] The pretensioner 30 is a mechanism that removes slack in the webbing 16 attached to the occupant by forcibly rotating the spool 14 in the winding direction in the event of a vehicle emergency. The pretensioner 30 is equipped with a rotating member (sometimes called a "pinion") 32 shown in Figures 1 and 2 inside the cover plate 20.

[0030] The rotating member 32 is made of metal and is arranged coaxially with the spool 14. In the event of a vehicle emergency, the rotating member 32 is connected to the spool 14 via a clutch (not shown) and is coupled to the spool 14 so as to be able to rotate integrally with it. When the rotating member 32 is rotated to one side (in the same direction as arrow A) while connected to the spool 14, the spool 14 is configured to rotate in the winding direction. As shown in Figure 2, multiple external teeth 32A, which serve as first teeth, are formed on the outer circumference of the rotating member 32 so as to be arranged in the circumferential direction.

[0031] Furthermore, as shown in Figure 1, the pretensioner 30 is equipped with a pipe (sometimes referred to as a "cylinder") 40 that serves as a cylindrical guide member. The pipe 40 is made of metal and is bent at approximately right angles in the axial middle section as appropriate. The axial base end 40A of the pipe 40 is positioned on the upper rear side of the frame 12, and is formed so that its central axis is straight, and its diameter is set to be larger than other general parts of the pipe 40. The axial tip end 40B of the pipe 40 is fixed in place by being inserted into the upper inner side in the vehicle width direction of the cover plate 20.

[0032] A micro gas generator 42 (shown as a dashed line in the figure for convenience) is inserted into the axial base end 40A of the pipe 40 as a fluid supply means. In the following description, the micro gas generator 42 will be referred to as "MGG42". The MGG42 is electrically connected to a collision detection sensor (not shown in the figure) installed in the vehicle via an ECU as a control means. When the impact of a vehicle collision is detected by the collision detection sensor, the MGG42 is activated by the ECU, and gas, which is a form of fluid generated in the MGG42, is supplied to the inside of the pipe 40.

[0033] Furthermore, a sealing ball 38 and a movable member 36 are arranged inside the pipe 40. The pipe 40 serves as a guide for the movement of the sealing ball 38 and the movable member 36. The sealing ball 38 is an element that can be gripped as a piston, is made of resin, and is formed to slide while sealing the inner surface of the pipe 40 in response to gas supplied from the MGG 42. The movable member 36 is made of resin and is formed in an elongated shape, and is deformable when subjected to external force. The movable member 36 is sometimes referred to as a resin rack or resin piston.

[0034] The movable member 36 is positioned inside the pipe 40 on the opposite side from the MGG42 side relative to the seal ball 38. When the seal ball 38 is guided and moved along the pipe 40 by the gas supplied from the MGG42, the movable member 36 is pressed by the seal ball 38 and moves along the inside of the pipe 40. As the movable member 36 shown in Figure 2 moves toward the axial end, the external teeth 32A of the rotating member 32 engage as shown in Figure 3, causing the rotating member 32 to rotate to one side (in the same direction as arrow A). This rotation of the rotating member 32 causes the spool 14 (see Figure 1) to rotate in the winding direction.

[0035] A portion of the inner surface of the cover plate 20 serves as a guide portion 20G that guides the moving member 36, which has passed through the rotating member 32, in a predetermined direction of travel. Furthermore, as shown in Figure 1, the diameter of the moving member 36 is set to be larger than the width of the external teeth 32A of the rotating member 32 (the length in the left-right direction in Figure 1). This is to ensure that there is a sufficient portion of the moving member 36 that engages with the external teeth 32A of the rotating member 32.

[0036] As shown in Figure 2, a metal (for example, steel) engaging member 34 is provided at the axial end of the movable member 36. The steel engaging member 34 is sometimes referred to as an iron piston. The movable member 36 and the engaging member 34 are integrated by molding, for example. As a modified example, the movable member (36) and the engaging member (34) may be integrated by a separate pin that protrudes from both of them.

[0037] The meshing member 34 is formed in a plate-like shape and has multiple rack teeth 34A as second teeth arranged in a row on one side, with one of the rack teeth 34A positioned in contact with the external teeth 32A of the rotating member 32. When the meshing member 34 is pushed by the moving member 36, the rack teeth 34A mesh with the external teeth 32A and move in a straight line, causing the rotating member 32 to rotate to one side (in the same direction as arrow A).

[0038] On the other hand, a recess 20X is formed in the lower part of the cover plate 20, which is recessed downwards. The receiving portion 20A that forms the lower part of the recess 20X is provided on the side of the meshing member 34 in the direction of movement of the meshing member 34 when the meshing member 34 rotates the rotating member 32 to one side (in this case, directly below the meshing member 34). As shown in Figure 3, the receiving portion 20A is a component that receives the meshing member 34 when it is pushed by the moving member 36 and moves, thereby separating the meshing member 34 from the axial end of the moving member 36.

[0039] Furthermore, the end of the meshing member 34 that is pressed by the moving member 36 has a guide surface 34B formed thereon that guides the moving member 36 in a predetermined direction of travel when the meshing member 34 is received by the receiving portion 20A. The guide surface 34B is formed in an inclined arc shape in the direction in which the moving member 36 is to be moved when viewed along the central axis of the rotating member 32 (view in the direction shown in Figure 3).

[0040] <Effects and Actions> Next, the operation and effects of this embodiment will be described.

[0041] In the webbing winding device 10 shown in Figure 1, in the event of a vehicle collision, which is one manifestation of a vehicle emergency, the ECU activates the MGG42 of the pretensioner 30, and high-pressure gas is instantly supplied from the MGG42 to the inside of the pipe 40. The pressure of this gas causes the seal ball 38 to move inside the pipe 40, and this seal ball 38 presses against the resin moving member 36, causing it to move toward the axial end. In addition, in the event of a vehicle emergency, the rotating member 32 is connected to the spool 14 so as to be able to rotate integrally with it.

[0042] When the metal meshing member 34 is pressed against the resin moving member 36, the rack teeth 34A of the meshing member 34 shown in Figure 2 mesh with the external teeth 32A of the rotating member 32 and move in a straight line, causing the rotating member 32 to rotate to one side (in the same direction as arrow A). Here, since the meshing member 34 is made of metal, deformation is suppressed when it meshes with the rotating member 32, and it can mesh well with the rotating member 32. In other words, good meshing between the rotating member 32 and the power transmission member can be achieved in the initial stages of a vehicle emergency. When the rotating member 32 rotates, the spool 14 shown in Figure 1 rotates in the winding direction, and the webbing 16 is wound onto the spool 14.

[0043] Subsequently, as shown in Figure 3, the external teeth 32A of the rotating member 32 bite into the moving member 36, causing the moving member 36 to rotate the rotating member 32 to one side (in the same direction as arrow A), and the spool 14 (see Figure 1) continues to rotate in the winding direction.

[0044] On the other hand, when the meshing member 34 is pushed by the moving member 36 and moves, it is received by the receiving portion 20A and moves away from the axial end of the moving member 36. This suppresses the occurrence of malfunctions caused by the metal meshing member 34 coming into contact with surrounding members along the path of the moving member 36, and also reduces operating resistance. Furthermore, since the receiving portion 20A is provided on the side of the meshing member 34 in the straight-line direction when the meshing member 34 rotates the rotating member 32 to one side, the amount of movement of the meshing member 34 can be kept to a minimum.

[0045] Furthermore, in this embodiment, when the engaging member 34 is received by the receiving portion 20A, the guide surface 34B of the engaging member 34 guides the moving member 36 in a predetermined direction of travel. As a result, the moving member 36 can be moved smoothly in a predetermined direction of travel.

[0046] Furthermore, in this embodiment, as described above, the engagement between the rotating member 32 and the power transmission member can be improved in the initial stages of a vehicle emergency, making it possible to reduce the longitudinal length of the moving member 36, and consequently, to reduce the overall size of the device. In addition, this embodiment has the inherent advantages of being relatively low-cost and lightweight, as it uses a long, resin-made moving member 36 to rotate the rotating member 32 in a vehicle emergency.

[0047] [Second Embodiment] Next, a webbing winding device 50 according to a second embodiment of the present invention will be described with reference to Figures 4 to 6. The second embodiment has substantially the same configuration as the first embodiment, except for the points described below. Therefore, in the second embodiment, components that are substantially the same as those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0048] <Structure> As shown in Figure 4, the webbing winding device 50 includes a cover plate 52 in place of the cover plate 20 (see Figure 1) of the first embodiment. The internal shape of the cover plate 52 will be described later. In Figure 4, a portion of the inside of the cover plate 52 is shown by cutting out a part of it (the same applies to Figure 6). The pretensioner 60 of this embodiment includes a rotating member 62 shown in Figures 4 and 5 inside the cover plate 52. The pretensioner 60 has the same configuration as the pretensioner 30 (see Figure 1) of the first embodiment, except for the points described below.

[0049] The rotating member 62 shown in Figure 4 is made of metal and is positioned coaxially with the spool 14. In the event of a vehicle emergency, the rotating member 62 is connected to the spool 14 via a clutch (not shown) and is coupled to the spool 14 so as to be able to rotate integrally with it. When the rotating member 62 is rotated to one side (in the same direction as arrow A) while connected to the spool 14, the spool 14 is configured to rotate in the winding direction.

[0050] The rotating member 62 has a first rotating portion 64 and a second rotating portion 66 arranged in series along its central axis. The first rotating portion 64 is made of a material with higher strength than the second rotating portion 66. The second rotating portion 66 is positioned closer to the spool 14 than the first rotating portion 64 and has a larger diameter than the first rotating portion 64. The second rotating portion 66 is connected to the first rotating portion 64 by a breaking pin (not shown as an example) and is provided to rotate integrally with the first rotating portion 64. The breaking pin is configured to break and allow the second rotating portion 66 to rotate relative to the first rotating portion 64 when the rotational load of the relative rotation of the second rotating portion 66 with respect to the first rotating portion 64 exceeds a predetermined value.

[0051] As shown in Figure 5, multiple (six as an example in this embodiment) occluding teeth 64A (parts of multiple first teeth) are formed on the outer circumference of the first rotating part 64 so as to be arranged in the circumferential direction. In addition, multiple (nine as an example in this embodiment) grafting teeth 66A (other parts of multiple first teeth) are formed on the outer circumference of the second rotating part 66 so as to be arranged in the circumferential direction. In this embodiment, the number of grafting teeth 66A of the second rotating part 66 (nine) is greater than the number of occluding teeth 64A of the first rotating part 64 (six).

[0052] The webbing winding device 50 has a moving member 74 instead of the moving member 36 (see Figure 1) of the first embodiment. The moving member 74 differs from the moving member 36 (see Figure 1) of the first embodiment in that, as seen in the rear view of the device shown in Figure 4, it has an inclined surface 74A at its axial end that slopes inward in the width direction of the device and downward towards the device, but in other respects it is substantially the same as the moving member 36 (see Figure 1) of the first embodiment. The elongated resin moving member 74 is moved toward the axial end, and the biting teeth 66A of the rotating member 62 shown in Figure 5 bite into it, causing the rotating member 62 to rotate to one side (in the same direction as arrow A). A part of the inner surface of the cover plate 52 is a guide portion 52G that guides the moving member 74, which has passed through the rotating member 62, in a predetermined direction of travel.

[0053] A metal (for example, steel) meshing member 70 is provided at the axial end of the movable member 74. The movable member 74 and the meshing member 70 are integrated by a separate pin 72 (see Figure 4) that protrudes into both of them. The meshing member 70 is formed in a plate-like shape and has multiple rack teeth 70A as second teeth arranged in a row on one side, with the multiple rack teeth 70A in contact with the meshing teeth 64A of the rotating member 62. When the meshing member 70 is pushed by the movable member 74, the rack teeth 70A mesh with the meshing teeth 64A of the rotating member 62 and move in a straight line, causing the rotating member 62 to rotate to one side (in the same direction as arrow A).

[0054] On the other hand, as shown in Figure 4, a receiving portion 52A is formed on the lower side of the cover plate 52. The receiving portion 52A is provided on the side of the meshing member 70 in the direction of straight-line movement (in this case, directly below the meshing member 70) when the meshing member 70 rotates the rotating member 62 to one side. As shown in Figure 6, the receiving portion 52A is a component that receives the meshing member 70 when it is pushed by the moving member 74 and moves, thereby separating the meshing member 70 from the axial end of the moving member 74.

[0055] Furthermore, at the end of the engaging member 70 that is pressed by the moving member 74, a guide surface 70B is formed, which guides the moving member 74 from near the outer circumference of the first rotating part 64 to the outer circumference of the second rotating part 66 (in a predetermined direction of travel) when the engaging member 70 is received by the receiving part 52A. The guide surface 70B is inclined downward toward the second rotating part 66 when viewed from the rear of the device (viewed in the direction of Figure 6).

[0056] <Effects and Actions> Next, the operation and effects of this embodiment will be described.

[0057] In the webbing winding device 50 shown in Figure 4, when the MGG42 of the pretensioner 60 is activated in the event of a vehicle emergency, high-pressure gas is instantly supplied from the MGG42 to the inside of the pipe 40. The pressure of this gas causes the seal ball 38 to move inside the pipe 40, and this seal ball 38 presses against the resin moving member 74, causing it to move axially toward the end. In addition, in the event of a vehicle emergency, the rotating member 62 is connected to the spool 14 so as to be able to rotate integrally with it.

[0058] When the metal meshing member 70 is pressed against the resin moving member 74, the rack teeth 70A of the meshing member 70 shown in Figure 5 mesh with the meshing teeth 64A of the rotating member 62 and move in a straight line, causing the rotating member 62 to rotate to one side (in the same direction as arrow A). This ensures good meshing between the rotating member 62 and the power transmission member in the initial stages of a vehicle emergency. When the rotating member 62 rotates, the spool 14 shown in Figure 4 rotates in the winding direction, and the webbing 16 is wound onto the spool 14.

[0059] Subsequently, as shown in Figure 6, when the engaging member 70 is received by the receiving portion 52A, the guide surface 70B of the engaging member 70 guides the moving member 74 toward the outer circumference of the second rotating portion 66. As the moving member 74 moves toward the outer circumference of the second rotating portion 66, the biting teeth 66A of the second rotating portion 66 bite into the moving member 74, causing the moving member 74 to attempt to rotate the second rotating portion 66 of the rotating member 62 toward one side (in the same direction as arrow A).

[0060] At this time, the first rotating part 64 is unable to rotate because it is engaged with the rack teeth 70A (see Figure 5) of the engaging member 70 which is received by the receiving part 52A. Therefore, a rotational load of relative rotation of the second rotating part 66 acts on the first rotating part 64, and when this rotational load exceeds a predetermined value, the breaking pin (not shown) breaks, causing the second rotating part 66 to rotate relative to the first rotating part 64. In other words, in the second embodiment, the engaging member 70 which engages with the first rotating part 64 has the function of guiding the moving member 74, while the moving member 74 can rotate the second rotating part 66. When the second rotating part 66 rotates, the spool 14 rotates in the winding direction, and the webbing 16 is wound onto the spool 14.

[0061] Furthermore, in this embodiment, the second rotating portion 66 is formed with a larger diameter than the first rotating portion 64. Therefore, for example, the rotating member 62 can be rotated with less force compared to the case where the second rotating portion (66) has the same diameter as the first rotating portion (64). In this embodiment, the rotating member 62 has a separate portion that engages with the rack teeth 70A of the meshing member 70 shown in Figure 5 (measuring teeth 64A of the first rotating portion 64) and a portion that bites into the moving member 74 (biting teeth 66A of the second rotating portion 66). This configuration allows for good meshing between the rotating member 62 and the meshing member 70 in the initial stages of an emergency, while increasing the design freedom for rotating the rotating member 62 by the movement of the moving member 74.

[0062] On the other hand, as shown in Figure 6, the meshing member 70 is received by the receiving portion 52A and moves away from the axial end of the moving member 74, so that malfunctions caused by the metal meshing member 70 coming into contact with surrounding members along the path of the moving member 74 can be suppressed, and operating resistance can also be suppressed. Furthermore, since the receiving portion 52A is provided on the side of the meshing member 70 in the direction of straight-line movement when the meshing member 70 rotates the rotating member 62 to one side, the amount of movement of the meshing member 70 can be kept to a minimum.

[0063] [Differentiation] Next, a modified example of the configuration for integrating the movable member 74 and the engaging member 70 will be described with reference to Figures 7A to 7C. Note that even if some parts of the components shown in Figures 7A to 7C differ from those of the movable member 74 and engaging member 70 shown in Figure 4, for convenience, the same reference numerals are used for each component in each figure.

[0064] First, as a first modification, as shown in Figure 7A, a protrusion 70C is formed on the meshing member 70 that protrudes from the guide surface 70B side, and a recess 74B is formed on the inclined surface 74A side of the movable member 74 in a shape that fits the protrusion 70C, and the movable member 74 and the meshing member 70 are integrated by fitting (press-fitting) the protrusion 70C into the recess 74B.

[0065] Furthermore, as a second modification, as shown in Figure 7B, a protrusion 74C is formed on the movable member 74 that protrudes from the inclined surface 74A side, and a recess 70D is formed on the guide surface 70B side of the meshing member 70 in a shape that the protrusion 74C fits into, and the movable member 74 and the meshing member 70 are integrated by fitting (press-fitting) the protrusion 74C into the recess 70D.

[0066] Furthermore, as a third modification, as shown in Figure 7C, the movable member 74 and the interlocking member 70 may be integrated by molding.

[0067] Next, a modified example in which the movable member 74 and the interlocking member 70 are not integrated will be described with reference to Figure 8. In Figure 8, components that are substantially the same as those in the second embodiment are denoted by the same reference numerals.

[0068] In the modified webbing winding device 80 shown in Figure 8, the movable member 74 and the meshing member 70 are arranged adjacent to each other without being integrated, but for convenience, the movable member 74 and the meshing member 70 are given the same reference numerals as in the second embodiment. The webbing winding device 80 has a shear pin 82 that protrudes toward the second rotating part 66 from a portion of the cover plate 52 that is located on the vehicle front side (the front side of the page in Figure 8) of the second rotating part 66 (not shown). The meshing member 70 is supported by the shear pin 82, which is positioned so that the shear pin 82 passes through the concave portion between the rack teeth 70A. The shear pin 82 is set to break when it receives a downward load from the meshing member 70 when the pretensioner 60 is operating. With this configuration, substantially the same operation and effects as in the second embodiment can be obtained.

[0069] In the webbing winding devices 10 and 50 of the first and second embodiments shown in Figures 1 to 6, the meshing members 34 and 70 are configured to separate from the axial end side of the moving members 36 and 74 during the movement of the moving members 36 and 74. While this configuration is preferred, as a modified example, the meshing members (34 and 70) are fixed to the moving members (36 and 74), and a configuration can be adopted in which the meshing members (34 and 70) do not separate from the meshing members (34 and 70) during the movement of the moving members (36 and 74).

[0070] Furthermore, in the first and second embodiments described above, the receiving portions 20A and 52A are provided on the side of the interlocking members 34 and 70 in the straight-ahead direction when the interlocking members 34 and 70 rotate the rotating members 32 and 62 to one side. While this configuration is preferred, other configurations are also possible, for example, in which the portion corresponding to the recess 20X shown in Figure 3 is tilted slightly outward in the vehicle width direction, with the entire portion facing downward towards the vehicle, so that the receiving portion (20A) is provided off-center from the straight-ahead side of the interlocking member (34).

[0071] Furthermore, in the first and second embodiments shown in Figures 1 to 6, the interlocking members 34 and 70 are equipped with guide surfaces 34B and 70B, and this configuration is preferred. However, as a modified example, a configuration can also be adopted in which the interlocking members (34 and 70) do not have guide surfaces (34B and 70B), and a separate guide component is provided.

[0072] Furthermore, in the second embodiment described above, the meshing member 70 is received by the receiving portion 52A and the rack teeth 70A of the meshing member 70 are meshed with the meshing teeth 64A of the first rotating portion 64. While this configuration is preferred, as a modified example, for instance, the meshing member (70) may have a shorter linear length than in the second embodiment, and the rack teeth (70A) of the meshing member (70) may not be meshed with the meshing teeth (64A) of the first rotating portion (64) when the meshing member (70) is received by the receiving portion (52A). In such a modified example, instead of the guide surface (70B) of the meshing member (70), a separate guide portion is provided to guide the moving member (74) from near the outer circumference of the first rotating portion (64) to the outer circumference of the second rotating portion (66). On the other hand, in such modified examples, it is not necessary to adopt a connection configuration in which the first rotating part (64) and the second rotating part (66) rotate relative to each other when certain conditions are met, and the first rotating part (64) may be fixed to the second rotating part (66).

[0073] Furthermore, the first and second embodiments described above, as well as the various modifications described above, can be combined and implemented as appropriate.

[0074] Although an example of the present invention has been described above, the present invention is not limited to the above, and it is of course possible to implement it in various modified forms without departing from its spirit. [Explanation of symbols]

[0075] 10...Webbing winding device, 14...Spool, 16...Webbing, 20A...Receiving part, 32...Rotating member, 32A...External teeth (first teeth), 34...Engaging member, 34A...Rack teeth (second teeth), 34B...Guide surface, 36...Moving member, 50...Webbing winding device, 52A...Receiving part, 62...Rotating member, 64...First rotating part, 64A...Engaging teeth (first teeth), 66...Second rotating part, 66A...Engaging teeth (first teeth), 70...Engaging member, 70A...Rack teeth (second teeth), 70B...Guide surface (guide part), 74...Moving member, 80...Webbing winding device, A...Winding direction

Claims

1. A spool that is rotated in the winding direction and onto which the webbing of the seat belt device is wound, A rotating member having multiple first teeth formed on its outer circumference, which is connected to the spool so as to be able to rotate integrally with it in the event of a vehicle emergency, and which rotates to one side while connected to the spool, thereby causing the spool to rotate in the winding direction, A resin movable member formed in an elongated shape, which moves toward the axial end and engages with the first tooth to rotate the rotating member toward the first side, A metal meshing member is provided on the axial end side of the moving member, has a plurality of second teeth, and is positioned so that at least one of the plurality of second teeth is in contact with the first tooth, and when pushed by the moving member, the second teeth mesh with the first tooth and move in a straight line, causing the rotating member to rotate toward the one side, A webbing winding device equipped with [a specific feature].

2. The webbing winding device according to claim 1, further comprising a receiving portion that receives the engaging member which has been moved by being pushed by the moving member, thereby separating the engaging member from the axial end of the moving member.

3. The webbing winding device according to claim 2, wherein the receiving portion is provided on the side of the meshing member in the straight-line direction when the meshing member rotates the rotating member toward the one side.

4. The webbing winding device according to claim 2, wherein the end of the engaging member that is pressed by the moving member has a guide surface formed thereon that guides the moving member in a predetermined direction of travel when the engaging member is received by the receiving portion.

5. The rotating member has a first rotating portion and a second rotating portion arranged in series along its central axis, The first rotating portion has a plurality of occlusal teeth on its outer circumference as part of the plurality of first teeth, and the second teeth are configured to occlude with the occlusal teeth. The second rotating portion has a plurality of biting teeth on its outer circumference as an additional part of the plurality of first teeth, and is configured such that the biting teeth bite into the moving member. Furthermore, the webbing winding device according to claim 1 is provided with a guide portion that guides the moving member from near the outer circumference of the first rotating portion to the outer circumference of the second rotating portion.

6. The device includes a receiving portion that receives the engaging member, which has been moved by being pushed by the moving member, thereby separating the engaging member from the axial end of the moving member. The guide portion is formed on the end of the meshing member that is pressed by the moving member, and serves as a guide surface that guides the moving member toward the outer circumference of the second rotating portion when the meshing member is received by the receiving portion. The webbing winding device according to claim 5, wherein the second rotating part is provided so as to be rotatable integrally with the first rotating part, and is configured to rotate relative to the first rotating part when the rotational load of the second rotating part relative to the first rotating part exceeds a predetermined value.

7. The webbing winding device according to claim 5, wherein the second rotating part is formed to have a larger diameter than the first rotating part.

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