Webbing take-up device

Abstract

To inhibit deformation of a deformation member by rotational force transmitted to a restriction body and acting in a take-up direction.SOLUTION: In a webbing take-up device, when rotation of a pinion 28 in a drawing direction is restricted, a torsion shaft 20 is deformed to allow rotation of a spool 16 in the drawing direction relative to the pinion 28. Here, when the rotational force in a take-up direction is transmitted to the pinion 28, a pawl 30 allows the pinion 28 to communicate with the spool 16 with a lock gear 32 to transmit the rotational force in the take-up direction to the spool 16. Thus, deformation of the torsion shaft 20 can be inhibited.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a webbing take-up device in which rotation of a spool in the unwinding direction is permitted when rotation of a restricting body in the unwinding direction is restricted. [Background technology]

[0002] In the retractor described in Patent Document 1 below, when the rotation of the locking base in the pull-out direction is restricted, the torsion bar is twisted and deformed, allowing the spool to rotate in the pull-out direction.

[0003] In this retractor, when the pretensioner transmits a rotational force in the winding direction to the locking base (ring gear), the torsion bar is twisted and the rotation of the locking base (ring member) in the winding direction is restricted, thereby stopping the torsional deformation of the torsion bar. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-175754 Summary of the Invention [Problem to be solved by the invention]

[0005] In consideration of the above, an object of the present invention is to provide a webbing take-up device that can suppress deformation of a deformable member due to a rotational force in the take-up direction that is transmitted to a regulating body. [Means for solving the problem]

[0006] A webbing take-up device of a first aspect of the present invention includes a spool around which the webbing worn by an occupant is rotated in the take-up direction to be taken up and the webbing is pulled out and rotated in the pull-out direction; a regulating body that can transmit rotational force in the take-up direction and can restrict rotation in the pull-out direction; a communication mechanism that connects the regulating body to the spool when the rotational force in the take-up direction is transmitted to the regulating body to transmit the rotational force in the take-up direction to the spool; and a deformation member that deforms when rotation of the regulating body in the pull-out direction is restricted to allow rotation of the spool in the pull-out direction.

[0007] A webbing take-up device of a second aspect of the present invention is the webbing take-up device of the first aspect of the present invention, wherein when a rotational force in the winding direction is transmitted to the regulating body, the regulating body rotates relative to the spool and the communication mechanism connects the regulating body to the spool.

[0008] A webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the first or second aspect of the present invention, wherein the regulating body is rotatable by a predetermined amount relative to the spool in the take-up direction.

[0009] A webbing take-up device of a fourth aspect of the present invention is a webbing take-up device of any one of the first to third aspects of the present invention, further comprising a biasing member that rotates the regulating body in the take-up direction by a biasing force when the regulating body stops rotating in the take-up direction due to the transmitted rotational force.

[0010] A webbing take-up device of a fifth aspect of the present invention is the webbing take-up device of any one of the first to fourth aspects of the present invention, further comprising a connecting member that is provided in the connecting mechanism and connects the regulating body to the spool.

[0011] A webbing take-up device of a sixth aspect of the present invention is the webbing take-up device of the fifth aspect of the present invention, further comprising a displacement body provided in the connection mechanism that displaces the connection member to a side of the regulating body that is connected to the spool and a side of the regulating body that is released from connection with the spool.

[0012] A webbing take-up device of a seventh aspect of the present invention is the webbing take-up device of the sixth aspect of the present invention, wherein rotation of the displacement body is restricted and the connecting member is displaced to a side of the restriction body that releases communication with the spool. [Effects of the Invention]

[0013] In the webbing take-up device of the first aspect of the present invention, the spool is rotated in the take-up direction, and the webbing to be worn by an occupant is taken up onto the spool, and the webbing is pulled out from the spool, and the spool is rotated in the pull-out direction. Furthermore, when the rotation of the restricting body in the pull-out direction is restricted, the deformation member is deformed, and rotation of the spool in the pull-out direction is permitted.

[0014] When a rotational force in the winding direction is transmitted to the restrictor, the communication mechanism connects the restrictor to the spool, thereby transmitting the rotational force in the winding direction to the spool, thereby suppressing deformation of the deformable member.

[0015] In the webbing take-up device of the second aspect of the present invention, when a rotational force in the take-up direction is transmitted to the regulating body, the regulating body rotates relative to the spool and the communication mechanism connects the regulating body to the spool, thereby making it easy to connect the regulating body to the spool.

[0016] In the webbing take-up device of the third aspect of the present invention, the restrictor is rotatable relative to the spool by a predetermined amount in the take-up direction, which makes it possible to effectively suppress deformation of the deformable member when a rotational force in the take-up direction is transmitted to the restrictor.

[0017] In the webbing take-up device of the fourth aspect of the present invention, when the rotation of the regulating body in the take-up direction due to the transmitted rotational force is stopped, the urging member rotates the regulating body in the take-up direction by the urging force of the urging member, so that the regulating body can be rotated in the unwinding direction against the urging force of the urging member.

[0018] In the webbing take-up device of the fifth aspect of the present invention, the connecting member of the connecting mechanism connects the restricting body to the spool, so that the restricting body can be easily connected to the spool.

[0019] In the webbing take-up device of the sixth aspect of the present invention, the displacement body of the communication mechanism displaces the communication member to the side of the regulating body that connects to the spool and the side of the regulating body that is released from communication with the spool, thereby enabling the regulating body to be connected to and released from communication with the spool.

[0020] In the webbing take-up device of the seventh aspect of the present invention, rotation of the displacement body is restricted and the connecting member is displaced to the side where the regulating body is released from communication with the spool, thereby enabling the regulating body to be appropriately released from communication with the spool. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view showing a webbing take-up device according to an embodiment of the present invention, viewed from below. [Figure 2] 1 is an exploded perspective view showing a main part of a webbing take-up device according to an embodiment of the present invention, as viewed from the left side. FIG. [Figure 3] (A) is an explanatory diagram showing the main parts of a webbing take-up device according to an embodiment of the present invention as seen from the left side, (B) shows the first stage of operation of the pretensioner mechanism in (A), (C) shows the second stage of operation of the pretensioner mechanism in (A), and (D) shows the third stage of operation of the pretensioner mechanism in (A). [Figure 4] (A) shows the fourth stage of operation of the pretensioner mechanism in Figure 3(A), (B) shows the fifth stage of operation of the pretensioner mechanism in Figure 3(A), (C) shows the sixth stage of operation of the pretensioner mechanism in Figure 3(A), and (D) shows the seventh stage of operation of the pretensioner mechanism in Figure 3(A). [Figure 5] (A) shows the first stage of webbing withdrawal allowance in Figure 3(A), (B) shows the second stage of webbing withdrawal allowance in Figure 3(A), (C) shows the third stage of webbing withdrawal allowance in Figure 3(A), and (D) shows the fourth stage of webbing withdrawal allowance in Figure 3(A). [Figure 6](A) shows the fifth stage of the webbing withdrawal allowance in FIG. 3(A), and (B) shows the sixth stage of the webbing withdrawal allowance in FIG. 3(A). DETAILED DESCRIPTION OF THE INVENTION

[0022] Fig. 1 shows a cross-sectional view of a webbing take-up device 10 according to an embodiment of the present invention as viewed from below. Furthermore, Fig. 2 shows an exploded perspective view of the main parts of the webbing take-up device 10 as viewed from the left side, and Fig. 3(A) shows an explanatory diagram of the main parts of the webbing take-up device 10 as viewed from the left side. In the drawings, the front of the webbing take-up device 10 is indicated by an arrow FR, and the right side of the webbing take-up device 10 is indicated by an arrow RH.

[0023] The webbing take-up device 10 according to this embodiment is installed in a vehicle, and the front, right and upper sides of the webbing take-up device 10 are oriented, for example, outward in the vehicle width direction, rearward and upward of the vehicle, respectively.

[0024] 1, the webbing retractor 10 is provided with a frame 12 having a U-shaped cross section as a support body, and the frame 12 is provided with a rear back plate 12A, a left leg plate 12B, and a right leg plate 12C. The frame 12 is fixed to the vehicle body at the back plate 12A, thereby installing the webbing retractor 10 on the vehicle.

[0025] A box-shaped cover plate 14 serving as a restricting member is fixed to the left side of the frame 12 (leg plate 12B), and the interior of the cover plate 14 is open to the right and closed from the right side by the leg plate 12B. A ratchet hole 14A is formed through the left wall of the cover plate 14, and ratchet teeth 14B serving as a restricting portion are formed around the entire periphery of the circumferential surface of the ratchet hole 14A.

[0026] 1, 2, and 3(A), a substantially cylindrical spool 16 is rotatably supported between the leg plates 12B and 12C of the frame 12, and the vicinity of the left end and the right end of the spool 16 are penetrated by the leg plates 12B and 12C, respectively. A predetermined number (six in this embodiment) of trapezoidal columnar first recesses 16A are formed on the inner peripheral surface of the right end of the spool 16, and the predetermined number of first recesses 16A extend in the axial direction of the spool 16 and are spaced apart in the circumferential direction of the spool 16. The left end of the spool 16 is expanded in diameter coaxially, and the inside of the left end of the spool 16 is expanded in diameter coaxially. A specified number (two in this embodiment) of right-angled triangular columnar connecting protrusions 16B serving as connecting portions are integrally formed on the inner surface of the left end of the spool 16, and the specified number of connecting protrusions 16B are arranged at equal intervals around the circumferential direction of the spool 16, with the pull-out side surface being perpendicular to the circumferential direction of the spool 16.

[0027] A long strip-shaped webbing 18 is wound around the spool 16 from the base end in the longitudinal direction, and when the spool 16 is rotated in a winding direction (the direction of arrow A in FIG. 2, etc.), the webbing 18 is wound around the spool 16, and when the webbing 18 is pulled out from the spool 16, the spool 16 is rotated in a pulling-out direction (the direction of arrow B in FIG. 2, etc.). When the webbing 18 is pulled out from the spool 16, the webbing 18 is applied to an occupant seated in a vehicle seat.

[0028] A metal, substantially cylindrical torsion shaft 20 serving as an energy absorbing member (deformable member) is coaxially arranged within the spool 16.

[0029] A predetermined number (six in this embodiment) of trapezoidal columnar first protrusions 20A are integrally formed on the peripheral surface of the right portion of the torsion shaft 20. The predetermined number of first protrusions 20A extend in the axial direction of the torsion shaft 20 and are spaced apart in the circumferential direction of the torsion shaft 20. The first protrusions 20A are fitted into first recesses 16A of the spool 16, whereby the right portion of the torsion shaft 20 is connected to the spool 16 so as to be rotatable therewith, and the torsion shaft 20 rotates integrally with the spool 16. Furthermore, the left portion of a substantially cylindrical connecting shaft 22 is coaxially inserted into and screwed onto the right end of the torsion shaft 20.

[0030] A specific number (three in this embodiment) of trapezoidal columnar second protrusions 20B are integrally provided on the circumferential surface of the left end of the torsion shaft 20, and a specific number of first protrusions 20A extend in the axial direction of the torsion shaft 20 and are arranged at intervals in the circumferential direction of the torsion shaft 20. A substantially cylindrical screw hole 20C is formed coaxially at the left end of the torsion shaft 20, and the screw hole 20C is open to the left side.

[0031] A biasing mechanism 24 is provided on the right side of the frame 12 (leg plate 12C), and a power spring (not shown) serving as a biasing portion is provided within the biasing mechanism 24. The power spring is connected to the right end of the spool 16 via the connecting shaft 22 and the right portion of the torsion shaft 20, and the power spring biases the spool 16 in the winding direction.

[0032] A substantially annular plate-shaped bearing 26 serving as a retaining member is coaxially disposed on the left side of the spool 16. A prescribed number (two in this embodiment) of curved bearing plates 26A are integrally provided on the inner peripheral end of the bearing 26, and the prescribed number of bearing plates 26A are disposed at equal intervals around the circumference of the bearing 26. The bearing plates 26A protrude to the right and are curved along the circumference of the bearing 26. Each bearing plate 26A is elastically fitted to the inner peripheral surface of the left end of the spool 16 and is elastically abutted against the respective connecting protrusions 16B from the winding direction side, thereby limiting the rotation of the bearing 26 relative to the spool 16. A long, plate-shaped bearing piece 26B is integrally formed at the winding direction side end of the bearing plate 26A, and the bearing piece 26B extends in a direction toward the radial inside of the bearing 26 as it moves toward the winding direction, with its tip bent radially outward of the bearing 26 and arranged approximately along the circumferential direction of the bearing 26.

[0033] A pinion 28 having a generally circular plate shape and serving as a connecting member constituting a regulating body is coaxially provided on the left side of the bearing 26, and the pinion 28 penetrates the bearing 26. A specific number (three in this embodiment) of curved rectangular column-shaped second recesses 28A are formed on the inner peripheral surface of the right end of the pinion 28. The specific number of second recesses 28A extend in the axial direction of the pinion 28 and are spaced apart circumferentially around the pinion 28. The left end of the torsion shaft 20 is coaxially inserted into the pinion 28, and the second protrusion 20B of the torsion shaft 20 is inserted into the second recess 28A. The circumferential dimension of the second recess 28A of the pinion 28 is larger than the circumferential dimension of the second protrusion 20B of the torsion shaft 20, and the second protrusion 20B abuts against the end face of the second recess 28A on the winding direction side. Therefore, the pinion 28 is rotatable by a predetermined amount relative to the torsion shaft 20 and the spool 16 in the winding direction, but is unable to rotate relative to the torsion shaft 20 and the spool 16 in the unwinding direction.

[0034] A plurality of trapezoidal locking pillars 28B (three in this embodiment) are integrally formed on the outer peripheral surface of the left part of the pinion 28, and the plurality of locking pillars 28B extend in the axial direction of the pinion 28 and are arranged at equal intervals around the pinion 28.

[0035] A specified number (two in this embodiment) of pawls 30 serving as communication members that constitute a communication mechanism are supported on the right side of the axial (left-right) middle portion of the pinion 28. The specified number of pawls 30 are arranged at equal intervals around the circumference of the pinion 28 and are rotatable around the base end. A cylindrical guide pin 30A is integrally provided on the tip end portion of the pawl 30, and the guide pin 30A protrudes to the right.

[0036] A generally cylindrical, bottomed lock gear 32 serving as a displacement body constituting a communication mechanism is coaxially disposed between the bearing 26 and the pinion 28, with the interior of the lock gear 32 open to the left. The right portion of the pinion 28 passes through and fits into the right wall (bottom wall) of the lock gear 32, and the lock gear 32 is rotatably supported by the pinion 28. Each bearing plate 26A of the bearing 26 is elastically fitted into the peripheral wall of the lock gear 32, thereby restricting the relative rotation of the lock gear 32 with respect to the bearing 26.

[0037] A specified number of elongated exposure holes 32A (two in this embodiment) are formed through the peripheral wall of the lock gear 32, and the specified number of exposure holes 32A are arranged at equal intervals in the circumferential direction of the lock gear 32 and extend in the circumferential direction of the lock gear 32. The connecting protrusion 16B of the spool 16 is arranged at the winding direction end position of the exposure hole 32A, and the exposure hole 32A exposes the connecting protrusion 16B inside the lock gear 32. The base end of the bearing piece 26B of the bearing 26 is arranged at the pull-out direction end position of the exposure hole 32A, and the bearing piece 26B extends into the lock gear 32 via the exposure hole 32A.

[0038] A specified number of elongated guide grooves 32B (two in this embodiment) are formed through the right wall of the lock gear 32. The specified number of guide grooves 32B are arranged at equal intervals around the circumferential direction of the lock gear 32 and extend radially outward of the lock gear 32 in the winding direction. A guide pin 30A of the pawl 30 of the pinion 28 is inserted into the end of the guide groove 32B in the pulling direction, and the guide pin 30A is fitted into the guide groove 32B in the width direction of the guide groove 32B. A bearing piece 26B of the bearing 26 elastically abuts the tip end portion of the pawl 30 from the radially outer side of the lock gear 32, and the bearing piece 26B urges the pawl 30 radially inward of the lock gear 32 (pinion 28).

[0039] A ratchet gear 32C having a substantially circular plate shape is provided integrally and coaxially with the left end of the lock gear 32, and the ratchet gear 32C protrudes radially outward from the lock gear 32 and from the left end of the spool 16 and the pinion 28. A lock pawl 34 (see FIG. 5(B)) is able to mesh with the ratchet gear 32C, and when the lock pawl 34 meshes with the ratchet gear 32C, rotation of the ratchet gear 32C in the pull-out direction is restricted, and rotation of the lock gear 32 in the pull-out direction is restricted (rotation of the ratchet gear 32C (lock gear 32) in the winding direction is permitted).

[0040] A substantially cylindrical spring 36 serving as a biasing member is coaxially fitted onto the outer periphery of the left portion of the pinion 28. A plurality of (three in this embodiment) spring portions 36A each having a U-shaped plate-like cross section are formed on the peripheral wall of the spring 36. The plurality of spring portions 36A are arranged at equal intervals around the circumferential direction of the spring 36 and extend in the axial direction (left-right direction) of the spring 36. A substantially rectangular insertion hole 36B is formed through the spring 36 on the winding direction side of each spring portion 36A, and the insertion hole 36B is open downward, into which a locking post 28B of the pinion 28 is inserted.

[0041] A substantially cylindrical pinion gear 38 is coaxially fitted onto the outer periphery of the spring 36. A plurality of (three in this embodiment) rectangular columnar locking holes 38A are formed in the inner circumferential surface of the pinion gear 38. The plurality of locking holes 38A are arranged at equal intervals in the circumferential direction of the pinion gear 38 and extend in the axial direction (left-right direction) of the pinion gear 38. A locking post 28B of the pinion 28 and a spring portion 36A of the spring 36 are inserted into the locking holes 38A, and the locking post 28B and the spring portion 36A are fitted into the locking holes 38A in the circumferential direction of the pinion gear 38, thereby restricting the relative rotation of the pinion gear 38 with respect to the pinion 28.

[0042] A generally annular plate-shaped lock base 40 serving as a regulated member constituting a regulating body is coaxially arranged on the left end of the pinion 28, to the left of the pinion gear 38, and the lock base 40 is connected to the pinion 28 so as to be rotatable together with the pinion 28. The lock base 40 is coaxially inserted through the ratchet hole 14A of the cover plate 14, and a lock plate 40A serving as a regulated part is rotatably supported on the left side of the lock base 40.

[0043] A substantially cylindrical screw shaft 42 is coaxially fitted into the pinion 28 and the lock base 40, and the left portion of the screw shaft 42 is engaged with the lock base 40 from the left side. The right end of the screw shaft 42 is threadedly engaged with the circumferential surface of the threaded hole 20C of the torsion shaft 20, whereby the pinion 28 is sandwiched between the left portion of the screw shaft 42 and the torsion shaft 20. Furthermore, the bearing 26 and the ratchet gear 32C of the lock gear 32 are sandwiched between the left end of the spool 16 and the pinion 28, and the spring 36 and pinion gear 38 are sandwiched between the pinion 28 and the lock base 40.

[0044] A sensor mechanism (not shown) is provided on the left side of the cover plate 14, and the sensor mechanism is connected to the lock plate 40A of the lock base 40. In the event of a vehicle collision (a vehicle emergency such as sudden deceleration of the vehicle or sudden withdrawal of the webbing 18 from the spool 16), the sensor mechanism is activated and the lock base 40 rotates in the withdrawal direction, causing the lock plate 40A to rotate radially outward of the lock base 40, thereby engaging the lock plate 40A with the ratchet teeth 14B of the cover plate 14 (ratchet hole 14A), and restricting (locking) rotation of the lock base 40 and pinion 28 in the withdrawal direction (rotation of the lock base 40 and pinion 28 in the winding direction is permitted).

[0045] The webbing take-up device 10 is provided with a pretensioner mechanism 44, and when a vehicle collision is detected, a gas generator in the pretensioner mechanism 44 instantaneously generates high-pressure gas in a cylinder, and a piston (rack) in the cylinder is moved out of the cylinder by the pressure of the gas, causing the piston to engage with the pinion gear 38 (for example, the pinion gear 38 bites into the piston), transmitting a rotational force in the take-up direction to the pinion gear 38. Furthermore, when the piston is moved, the lock pawl 34 is engaged with the ratchet gear 32C of the lock gear 32 in conjunction with the movement of the piston (see FIG. 5(B)).

[0046] Next, the operation of this embodiment will be described.

[0047] In the webbing take-up device 10 configured as described above, the webbing 18 is pulled out from the spool 16 and attached to the occupant. Furthermore, the spool 16 is rotated in the retracting direction by the biasing force of the power spring of the biasing mechanism 24, and the webbing 18 is retracted onto the spool 16, thereby removing slack from the webbing 18 attached to the occupant.

[0048] When a vehicle collision is detected, in pretensioner mechanism 44, the piston is moved out of the cylinder by the pressure of high-pressure gas, transmitting a rotational force in the winding direction to pinion gear 38. Therefore, the end surface of locking hole 38A of pinion gear 38 on the pull-out side elastically contracts spring portion 36A of spring 36 in the winding direction, and presses locking post 28B of pinion 28 in the winding direction via spring portion 36A, causing pinion gear 38, spring 36, and pinion 28 to rotate together in the winding direction (see FIG. 3(B)). Furthermore, the pawl 30 of the pinion 28 is rotated in the winding direction, and the guide pin 30A of the pawl 30 is moved in the winding direction along the guide groove 32B of the lock gear 32, whereby the pawl 30 is rotated radially outward of the pinion 28 and brought into contact with the inner circumferential surface of the left end of the spool 16, and is moved in the winding direction toward the bearing piece 26B of the bearing 26 (see FIGS. 3C and 3D). Note that relative rotation of the pinion 28 in the winding direction with respect to the torsion shaft 20 and the spool 16 is permitted when the second recess 28A of the pinion 28 rotates in the winding direction relative to the second protrusion 20B of the torsion shaft 20. Then, the tip end of the pawl 30 abuts against the connecting protrusion 16B of the spool 16 from the pull-out direction side, and the pinion 28 is connected to the spool 16 via the pawl 30, causing the spool 16 to rotate integrally with the pinion 28 in the winding direction (see (A) to (D) of FIG. 4). As a result, the webbing 18 is wound onto the spool 16, and the restraining force of the webbing 18 on the occupant is increased.

[0049] When the movement of the piston is stopped, the movement of the piston toward the cylinder is restricted by the gas pressure inside the cylinder, restricting the rotation of the pinion gear 38 in the pull-out direction. As a result, the spring portion 36A of the spring 36 is elastically expanded in the winding direction and presses the locking post 28B of the pinion 28 in the winding direction, causing the spool 16 to rotate integrally with the pinion 28 in the winding direction (see FIG. 5(A)).

[0050] Furthermore, when the occupant suddenly pulls out the webbing 18 from the spool 16 and rotates the spool 16 in the pull-out direction, the backlash between the first recess 16A of the spool 16 and the first protrusion 20A of the torsion shaft 20 disappears, and the second protrusion 20B of the torsion shaft 20 abuts against the end surface of the second recess 28A of the pinion 28 on the side in the pull-out direction, causing the spool 16, torsion shaft 20, pinion 28, and lock base 40 to rotate together in the pull-out direction. Note that even if the rotation of the pinion gear 38 in the pull-out direction is restricted, the locking pillar 28B of the pinion 28 elastically contracts the spring portion 36A of the spring 36 in the pull-out direction, thereby allowing the pinion 28 to rotate in the pull-out direction relative to the pinion gear 38. Furthermore, as described above, when the pretensioner mechanism 44 is activated and the piston is moved, the lock pawl 34 meshes with the ratchet gear 32C of the lock gear 32 in conjunction with the movement of the piston, thereby restricting rotation of the lock gear 32 in the pull-out direction (see FIG. 5(B)). Therefore, the guide pin 30A of the pawl 30 of the pinion 28 moves in the pull-out direction through the guide groove 32B of the lock gear 32, causing the pawl 30 to rotate radially inward of the pinion 28, and communication between the pawl 30 of the pinion 28 and the spool 16 (communicating protrusion 16B) is released (see FIGS. 5(C) and 5(D)).

[0051] Moreover, in the event of a vehicle collision (for example, when an occupant suddenly pulls out the webbing 18 from the spool 16), the sensor mechanism is activated, and the lock base 40 rotates in the pull-out direction, causing the lock plate 40A of the lock base 40 to rotate radially outward from the lock base 40, thereby engaging the lock plate 40A with the ratchet teeth 14B of the cover plate 14 (ratchet hole 14A), and restricting the rotation of the lock base 40 and the pinion 28 in the pull-out direction (see FIGS. 6A and 6B). Therefore, the rotation of the torsion shaft 20 in the pull-out direction is restricted, and the torsion shaft 20 restricts the rotation of the spool 16 in the pull-out direction, causing a torsion force to act on the torsion shaft 20. When the pulling load from the spool 16 to the webbing 18 from the occupant (rotational load in the unwinding direction of the spool 16) is equal to or greater than the torsional load resistance (force limiter load) of the torsion shaft 20, the torsion shaft 20 is torsionally deformed, allowing rotation of the spool 16 in the unwinding direction relative to the lock base 40 and the pinion 28 and allowing the webbing 18 to be unwound from the spool 16. As a result, the kinetic energy of the occupant is absorbed by the torsional deformation of the torsion shaft 20, and the occupant is protected.

[0052] Here, as described above, when the pretensioner mechanism 44 is activated and a rotational force in the winding direction is transmitted to the pinion 28 via the pinion gear 38 and the spring 36, the pawl 30 connects the pinion 28 to the spool 16 (connecting protrusion 16B) by the lock gear 32 (guiding groove 32B), thereby transmitting the rotational force in the winding direction to the spool 16. Therefore, the transmission of the rotational force of the pinion 28 in the winding direction to the torsion shaft 20 can be restricted, and torsional deformation of the torsion shaft 20 can be suppressed.

[0053] Furthermore, when a rotational force in the winding direction is transmitted to the pinion 28, the pinion 28 rotates relative to the spool 16 in the winding direction, and the pawl 30 connects the pinion 28 to the spool 16 via the lock gear 32. This makes it easy to connect the pinion 28 to the spool 16.

[0054] Furthermore, the second recess 28A of the pinion 28 is rotatable in the winding direction relative to the second protrusion 20B of the torsion shaft 20, allowing the pinion 28 to rotate a predetermined amount in the winding direction relative to the spool 16. Therefore, when a rotational force in the winding direction is transmitted to the pinion 28, the pinion 28 rotates in the winding direction relative to the torsion shaft 20, thereby effectively suppressing torsional deformation of the torsion shaft 20.

[0055] In addition, the lock gear 32 (guide groove 32B) rotates (displaces) the pawl 30 (guide pin 30A) to the side where the pinion 28 connects to the spool 16 (the radially outer side of the pinion 28) and the side where the pinion 28 releases communication with the spool 16 (the radially inner side of the pinion 28). This allows the pinion 28 to connect to and release from communication with the spool 16.

[0056] Furthermore, rotation of the lock gear 32 in the pull-out direction is restricted by the lock pawl 34, and the pawl 30 is rotated to the side where the pinion 28 is released from communication with the spool 16 (toward the radial inside of the pinion 28) (see FIGS. 5B to 5D). As a result, the pinion 28 can be appropriately released from communication with the spool 16.

[0057] Furthermore, when the movement of the piston of the pretensioner mechanism 44 is stopped and the rotation of the pinion 28 in the winding direction is stopped, the spring portion 36A of the spring 36 rotates the pinion 28 in the winding direction due to its biasing force (see FIG. 5(A)). Therefore, the pinion 28 can be rotated in the pull-out direction against the biasing force of the spring portion 36A, and the pawl 30 (guide pin 30A) can be rotated radially inward of the pinion 28 by the lock gear 32 (guide groove 32B), thereby releasing the connection of the pinion 28 to the spool 16 (communicating protrusion 16B) by the pawl 30.

[0058] In this embodiment, the pinion 28 is rotatable in the winding direction relative to the left portion of the torsion shaft 20. However, the right portion of the torsion shaft 20 may be rotatable in the winding direction relative to the spool 16. [Explanation of symbols]

[0059] 10 webbing take-up device, 16 spool, 18 webbing, 20 torsion shaft (deformable member), 28 pinion (regulating body), 30 pawl (communicating mechanism, connecting member), 32 lock gear (communicating mechanism, displacement body), 36 spring (urging member), 40 lock base (regulating body)

Claims

1. a spool around which the webbing to be worn by the occupant is rotated in a winding direction to be wound up and from which the webbing is pulled out and rotated in a pulling-out direction; a restricting body that can transmit a rotational force in the winding direction and restrict rotation in the pull-out direction; a communication mechanism that communicates the regulation body with the spool when a rotational force in the winding direction is transmitted to the regulation body, thereby transmitting the rotational force in the winding direction to the spool; a deformable member that is deformed when rotation of the restricting body in the pull-out direction is restricted to allow rotation of the spool in the pull-out direction; A webbing take-up device comprising:

2. The webbing take-up device according to claim 1, wherein when a rotational force in the winding direction is transmitted to the regulating body, the regulating body rotates relative to the spool, and the communication mechanism connects the regulating body to the spool.

3. 2. The webbing take-up device according to claim 1, wherein the restricting body is rotatable by a predetermined amount relative to the spool in the take-up direction.

4. The webbing take-up device according to claim 1, further comprising a biasing member that rotates the restricting body in the take-up direction by a biasing force when the restricting body stops rotating in the take-up direction due to the transmitted rotational force.

5. The webbing take-up device according to claim 1, further comprising a connecting member provided in the connecting mechanism for connecting the restricting body to the spool.

6. The webbing take-up device according to claim 5, further comprising a displacement body provided in the communication mechanism for displacing the communication member between a communication side of the regulating body with the spool and a communication-disengagement side of the regulating body with the spool.

7. 7. The webbing take-up device according to claim 6, wherein rotation of the displacement body is restricted so that the connecting member is displaced to a side of the restricting body that is released from communication with the spool.

Images