JP2002019580A - Webbing winding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase flexibility in setting of force limiter load. SOLUTION: In the webbing winding device 10, when a driving member 22 is caused by a pretensioner mechanism 20 to rotate in one direction, a roller 40 is urged by an inclined surface 30 and engages with a sleeve 14, so that the sleeve 14 is rotated integrally with the driving member 22, and a webbing 18 is wound. When the sleeve 14 is caused by a force limiter mechanism to rotate in the other direction, the driving member 22 is rotated a specified angle in the other direction through the roller 40, rotation of a lock ring 36 in the other direction is limited, and revolution of a roller 32 is limited. Consequently, the rotation of the sleeve 14 in relation to the driving member 22 is permitted, and extension of the webbing 18 can be prevented from being inhibited. Thus, the force limiter load can be determined only by load for deformation of an energy absorbing member, and the flexibility in the setting of the force limiter load can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a webbing winding provided with a pretensioner mechanism for removing slack of webbing in the event of a vehicle emergency and a force limiter mechanism for limiting the load on the occupant due to the webbing in an emergency of the vehicle to a certain amount or less. It relates to a taking device.

[0002]

2. Description of the Related Art Some webbing retractors have a pretensioner mechanism for removing loosening of a webbing in the event of a vehicle emergency due to a collision or the like.

[0003] Among such pretensioner mechanisms, for example, in a webbing take-up device provided with a so-called rack & pinion system, a pinion is connected to a take-up shaft for taking up the webbing, and the pinion is a take-up shaft. And always rotate together. A substantially cylindrical cylinder is provided in the vicinity of the pinion, and gas is supplied into the cylinder in an emergency of the vehicle.

[0004] A piston is movably provided in the cylinder, and a fitting portion is provided below the piston. The fitting portion is substantially fitted to the inner wall of the cylinder, and in an emergency of a vehicle, the piston receives the pressure of the gas from below the fitting portion and rises in the cylinder. In addition, a rack is provided above the piston, and when the piston is raised, the rack meshes with the pinion to rotate the pinion in the webbing winding direction. Thereby, in the event of an emergency of the vehicle, the webbing is wound around the winding shaft, and the slack of the webbing is removed.

Further, some of the above-described webbing retractors have a force limiter mechanism for limiting the load on the occupant due to the webbing to a certain amount or less in an emergency of the vehicle.

Such a force limiter mechanism has, for example, an energy absorbing member, and when the vehicle is in an emergency, the energy absorbing member is deformed by the load of the occupant on the webbing, so that the winding shaft is rotated in the webbing withdrawing direction. You. Thereby, in the event of a vehicle emergency, the webbing is pulled out from the winding shaft, and the load on the occupant due to the webbing is limited to a certain amount or less.

However, in such a webbing take-up device, when the force limiter mechanism is operated, the take-up shaft is rotated in the webbing take-out direction. Accordingly, the pinion is rotated in the webbing take-out direction, and the rack is removed. The piston is lowered through the cylinder via the piston. For this reason, the pressure of the gas in the cylinder (below the fitting portion) is increased, and the lowering of the piston is hindered. As a result, a load is applied to the rotation of the winding shaft in the webbing withdrawing direction via the rack and the pinion. As a result, pulling out of the webbing is hindered.

Therefore, as shown in FIG. 6, the so-called force limiter load (equal to the load for pulling out the webbing in the event of an emergency of the vehicle) is equal to the load for deforming the energy absorbing member and the pressure of gas in the cylinder ( The load caused by the lowering of the piston (the pressure increased by lowering the piston) (A in FIG. 6)
Is added. This allows
There is a problem that the degree of freedom in setting the force limiter load is reduced.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a webbing take-up device which can increase the degree of freedom in setting a force limiter load in consideration of the above fact.

[0010]

According to a first aspect of the present invention, there is provided a webbing take-up device configured to take up the webbing by being rotated in one direction and take up the webbing by being rotated in the other direction. A pretensioner mechanism that winds the webbing by rotating the winding shaft in the one direction in the event of a vehicle emergency, and a deformable energy absorbing member. A force limiter mechanism for rotating the take-up shaft in the other direction by deforming the energy absorbing member and pulling out the webbing; a webbing take-up device provided with the take-up shaft; A sleeve that always rotates integrally with the take-up shaft, and a substantially cylindrical peripheral wall provided in a state where the sleeve is surrounded by the peripheral wall; A drive member is rotated in the one direction by Na mechanism, is formed on the inner surface of the peripheral wall of the drive member,
An inclined surface approaching the sleeve side toward the other direction side, provided between the sleeve and the inclined surface, and is pressed against the inclined surface when the driving member is rotated in the one direction. A roller that is engaged with the sleeve, a lock ring that is formed in a substantially annular shape and surrounds the sleeve, and that holds the roller and always rotates with the roller; and a lock ring that is provided on the lock ring. Limiting means for restricting the rotation in the other direction, when the drive member is rotated in the one direction by the pretensioner mechanism, the roller is engaged with the sleeve by the inclined surface. While rotating the sleeve integrally with the driving member, the force limiter mechanism rotates the sleeve in the other direction via the winding shaft. In this case, the rotational force of the sleeve is transmitted to the drive member via the roller, the drive member is rotated in the other direction by a predetermined angle, and the rotation of the lock ring in the other direction is performed by the restricting means. By being restricted, the pressing of the roller by the inclined surface is released, and relative rotation of the sleeve with respect to the drive member is permitted.

In the webbing take-up device according to the first aspect, a pretensioner mechanism is provided. When the drive member is rotated in one direction by the pretensioner mechanism in an emergency of the vehicle, the inclined surface rotates in one direction against the roller between the inclined surface of the drive member peripheral wall and the sleeve, and the roller is pressed against the inclined surface. As a result, the roller is engaged with the sleeve.
Thereby, the sleeve is rotated integrally with the driving member,
The winding shaft is rotated in one direction. Therefore, in an emergency of the vehicle, the webbing is wound around the winding shaft, and the slack of the webbing is removed.

Further, in the webbing take-up device according to the first aspect, a force limiter mechanism is provided, and the energy absorbing member is deformed by an occupant load on the webbing in a vehicle emergency, so that the take-up shaft is provided. Is rotated in the other direction. Thereby, in the event of an emergency of the vehicle, the webbing is pulled out from the winding shaft, and the load on the occupant due to the webbing is limited to a certain amount or less.

Here, when the winding shaft is rotated in the other direction by the force limiter mechanism, the sleeve is rotated in the other direction. At this time, the rotational force of the sleeve is transmitted to the driving member via the roller, and the driving member is rotated by a predetermined angle in the other direction. Is restricted, the pressing of the roller by the inclined surface is released, and the relative rotation of the sleeve with respect to the drive member is permitted. Therefore, when the winding shaft is rotated in the other direction by the force limiter mechanism, the rotation of the winding shaft is not transmitted to the driving member,
Accordingly, even when a load is applied to the rotation of the driving member in the other direction, it is possible to prevent the rotation of the winding shaft in the other direction from being hindered and the webbing from being pulled out.

For this reason, the force limiter load (the load for pulling out the webbing in the event of an emergency of the vehicle) can be determined only by the load for deforming the energy absorbing member, whereby the setting of the force limiter load is free. The degree can be expanded.

[0015]

FIG. 3 is a side view showing a schematic configuration of a webbing take-up device 10 according to an embodiment of the present invention. FIG. The portion is shown in a sectional view (a sectional view taken along line 4-4 in FIG. 3).

The webbing take-up device 10 includes a frame 12
It has. The frame 12 is fixed to the vehicle,
A sleeve 14 is rotatably supported on the frame 12. A spool 16 as a winding shaft is integrally fixed to the outer periphery of the sleeve 14 in the frame 12,
The sleeve 14 and the spool 16 always rotate integrally.
A webbing 18 is wound around the spool 16,
The webbing 1 is rotated by rotating the spool 16 in one direction.
While the spool 8 is wound, the webbing 18 is pulled out by rotating the spool 16 in the other direction.

Further, the webbing take-up device 10 includes a pretensioner mechanism 20 of a rack and pinion system. Here, FIG. 1 shows a side view of an internal structure of a main part of the pretensioner mechanism 20.

As shown in FIG. 1, the pretensioner mechanism 2
0 has a driving member 22. The drive member 22 has a substantially cylindrical peripheral wall 24 and a substantially annular side wall 26 provided integrally with the peripheral wall 24. A pinion 28 is integrally provided at a central portion of the side wall 26, and a pinion 2 is provided.
The central portion of 8 is hollow. The pinion 28 is rotatably supported at the center at the end of the sleeve 14, and the drive member 22 is rotatably supported near the end of the sleeve 14 with the peripheral wall 24 surrounding the sleeve 14.

On the inner surface of the peripheral wall 24 of the driving member 22, a predetermined number (three in this embodiment) of inclined surfaces 30 are arranged along the circumferential direction.
Are formed. Each inclined surface 30 approaches the sleeve 14 as it goes to the other direction side.

Each inclined surface 30 of the driving member 22 and the sleeve 1
4, a substantially cylindrical roller 32 is provided. Each roller 32 is disposed near the one-side end of the inclined surface 30 by being held by a lock ring 36 as described later.
4.

A substantially annular lock ring 36 is arranged between the case gear 34 (see FIG. 4) fixed to the frame 12 and the drive member 22. As shown in detail in FIG. 5, the lock ring 36 includes a substantially annular gear portion 38 and a substantially cylindrical holding portion 4 erected integrally on the inner periphery of the gear portion 38.
0. A gear 38 </ b> A constituting a restricting means is formed on the outer periphery of the gear portion 38, and the gear 38 </ b> A is arranged outside the outer periphery of the driving member 22. on the other hand,
A predetermined number (three in this embodiment) of through-holes 42 are formed in the holding portion 40 in correspondence with the respective rollers 32.
Each through hole 42 has a size that allows the roller 32 to pass through. Three pairs of elastic holding pieces 44 are fixed to the outer peripheral surface of the holding section 40, and each pair of holding pieces 44 oppose each other with the through hole 42 interposed therebetween. The roller 32 is held by each pair of holding pieces 44, whereby the lock ring 36 holds the roller 32 and always rotates with the roller 32.

A fan-shaped lock pawl 46 in a plan view, which constitutes a restricting means corresponding to the gear 38A, is rotatably supported outside the lock ring 36.
Is meshed with the gear 38A by the urging force of the torsion coil spring 48 constituting the limiting means. Further, a lock plate 50 is fixed to the other side of the lock pawl 46, and the lock pawl 46 is locked to the lock plate 50, thereby preventing the lock pawl 46 from rotating in the other direction. Is done. Thus, the lock ring 36 is allowed to rotate only in one direction, and is not allowed to rotate in the other direction.
6 (restricted).

Here, as shown in FIG. 2, when the driving member 22 is rotated in one direction, the inclined surface 30 of the driving member 22 is rotated.
Is rotated in one direction with respect to the roller 32, and the roller 32 is pressed against the inclined surface 30, so that the roller 32 is
Is moved to the side of the sleeve 14 and is engaged with the sleeve 14. Thereby, the sleeve 14 is rotated integrally with the drive member 22, and the spool 16 is rotated in one direction.

On the other hand, when the sleeve 14 is rotated in the other direction after the roller 32 is engaged with the sleeve 14, the rotational force of the sleeve 14 is transmitted to the drive member 22 via the roller 32, and the drive member 22 is rotated. The rotation of the lock ring 36 in the other direction is restricted by the lock pawl 46 in the other direction, and the rotation of the roller 32 in the other direction is restricted by the lock pawl 46. The arrangement relationship with the roller 32 is almost returned to the arrangement relationship in the normal state (initial state) as shown in FIG. Thereby, the pressing of the roller 32 by the inclined surface 30 is released,
The relative rotation of the sleeve 14 with respect to the drive member 22 is permitted.

Further, as shown in FIG.
, A cylinder 52 is fixed. The cylinder 52 is formed in a substantially cylindrical shape, and an upper end side of the cylinder 52 is opened near the driving member 22. A gas supply port (not shown) is provided at the lower end side (opposite pinion 28 side) of cylinder 52.
Is provided, and a gas generator (not shown) is connected to the gas supply port. In an emergency of a vehicle due to a collision or the like, gas generated by the gas generator is supplied into the cylinder 52 from the gas supply port. .

A substantially cylindrical piston 5 is provided in the cylinder 52.
4 are provided, and the piston 54 is movable in the cylinder 52. A disk-shaped fitting portion 56 is formed near the lower end of the piston 54 (the end on the side opposite to the pinion 28), and the fitting portion 56 is substantially fitted to the inner wall of the cylinder 52. Here, the gas supply port is arranged below the fitting portion 56 (opposite the pinion 28), and when gas is supplied into the cylinder 52, the lower end of the piston 54 and the fitting portion 5
6 receives the pressure of this gas, and the piston 54 rises to the pinion 28 side.

An O-ring 58 made of resin is fitted to the lower portion of the piston 54 below the fitting portion 56.
The ring 58 is in close contact with the inner wall of the cylinder 52. As a result, the gas from the gas supply port flows through the gap between the fitting portion 56 and the inner wall of the cylinder 52 to above the fitting portion (the pinion 28).
Side) is prevented.

A rack 60 is provided above the piston 54. This rack 60 corresponds to the pinion 28, and when the piston 54 moves up to the pinion 28 side,
The rack 60 meshes with the pinion 28. Thereby, the driving member 22 is rotated in one direction via the pinion 28.

Further, the webbing retractor 10 has a force limiter mechanism (not shown), and the force limiter mechanism has an energy absorbing member (not shown). In an emergency of the vehicle, the energy absorbing member is deformed by the load of the occupant on the webbing 18, the spool 16 is rotated in the other direction, and the webbing 18 is
6 is derived from FIG.

Next, the operation of the present embodiment will be described.

In the webbing take-up device 10 having the above-described structure, the pretensioner mechanism 20 is provided, and in the event of a vehicle emergency, gas from the gas generator (not shown) is supplied from the gas supply port (not shown) into the cylinder 52 (not shown). When the gas is supplied to the lower side of the fitting portion 56 of the piston 54, the pressure of the gas causes the piston 54 to rise to the pinion 28 side and
8 is rotated in one direction, so that the driving member 22 is rotated in one direction. As shown in FIG. 2, when the driving member 22 is rotated in one direction, the inclined surface 3 of the roller 32 between the inclined surface 30 of the peripheral wall 24 of the driving member 22 and the sleeve 14 is used.
When the roller 0 is rotated in one direction and the roller 32 is pressed against the inclined surface 30, the roller 32 is moved toward the sleeve 14 through the through hole 42 and is engaged with the sleeve 14. Thereby, the sleeve 14 is rotated integrally with the drive member 22, and the spool 16 is rotated in one direction. Therefore,
In an emergency of the vehicle, the webbing 18 is wound around the spool 16 and the slack of the webbing 18 is removed.

Further, the webbing take-up device 10 is provided with a force limiter mechanism (not shown). In an emergency of the vehicle, the energy absorbing member (not shown) is deformed by the load of the occupant on the webbing 18 and the spool is wound. 16
Is rotated in the other direction. Thereby, in the event of an emergency of the vehicle, the webbing 18 is pulled out from the spool 16, and the load on the occupant by the webbing 18 is limited to a certain amount or less.

Here, when the spool 16 is rotated in the other direction by the force limiter mechanism, the sleeve 14 is rotated in the other direction. At this time, the rotational force of the sleeve 14 is transmitted to the drive member 22
Is rotated in the other direction by a predetermined angle, and the lock pawl 4
6, the rotation of the lock ring 36 in the other direction is restricted, and the rotation of the roller 32 in the other direction is restricted.
The arrangement relationship between the inclined surface 30 of the driving member 22 and the roller 32 is returned to the arrangement relationship in a normal state (initial state) as shown in FIG. As a result, the pressing of the roller 32 by the inclined surface 30 is released, and the relative rotation of the sleeve 14 with respect to the driving member 22 is permitted. Therefore, when the spool 16 is rotated in the other direction by the force limiter mechanism, the rotation of the spool 16 is not transmitted to the drive member 22, and as a result, the cylinder 52 is rotated as in the present embodiment.
Even when a load is applied to the rotation of the drive member 22 in the other direction due to the lowering of the piston 54 due to the gas inside, the rotation of the spool 16 in the other direction is hindered and the pulling out of the webbing 18 is hindered. Can be prevented.

For this reason, the force limiter load (the load for withdrawing the webbing 18 in the event of an emergency of the vehicle) can be determined only by the load for deforming the energy absorbing member, thereby setting the force limiter load. The degree of freedom can be expanded.

In the present embodiment, a plurality of grooves may be formed in a portion of the sleeve where the roller is engaged, so that the roller can be firmly engaged with the sleeve.

Further, in the present embodiment, a plurality of grooves may be formed on the peripheral wall of the roller, whereby the roller can be firmly engaged with the sleeve.

In this embodiment, the gear 38A, the lock pawl 46, the torsion coil spring 48, and the locking plate 50 are used as the restricting means. However, the spring clutch as the restricting means is provided on the outer periphery of the lock ring. It is also possible to provide a configuration in which only a rotation in one direction of the lock ring is permitted by a spring clutch to restrict a rotation in the other direction.

[0038]

According to the webbing take-up device of the first aspect, when the take-up shaft is rotated in the other direction by the force limiter mechanism, the rotation of the take-up shaft is not transmitted to the driving member, so that the force limiter load is reduced. Can be determined only by the load for deforming the energy absorbing member, and the degree of freedom in setting the force limiter load can be increased.

[Brief description of the drawings]

FIG. 1 is a side view showing an internal structure of a main portion of a pretensioner mechanism of a webbing take-up device according to an embodiment of the present invention in a normal state.

FIG. 2 is a side view showing an internal structure of a main portion of the pretensioner mechanism of the webbing take-up device according to the embodiment of the present invention when the pretensioner mechanism is operating.

FIG. 3 is a side view showing a schematic configuration of a webbing take-up device according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view (a cross-sectional view taken along line 4-4 in FIGS. 1 and 3) showing a main part of the webbing take-up device according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a lock ring (including a roller), a lock pawl, a torsion coil spring, and a locking plate of the webbing take-up device according to the embodiment of the present invention.

FIG. 6 is a graph showing a relationship between a force limiter load (vertical axis) and a drawn amount of webbing (horizontal axis) in a conventional webbing take-up device.

[Explanation of symbols]

 Reference Signs List 10 webbing take-up device 14 sleeve 16 spool (winding shaft) 18 webbing 20 pretensioner mechanism 22 drive member 24 peripheral wall 30 inclined surface 32 roller 36 lock ring 38A gear (restriction means) 46 lock pawl (restriction means) 48 torsion coil spring (Limiting means) 50 Locking plate (Limiting means)

Claims (1)

[Claims] 1. A winding shaft that winds up a webbing by being rotated in one direction and pulls out the webbing by being rotated in another direction, and rotates the winding shaft in the one direction in a vehicle emergency. A pretensioner mechanism that winds up the webbing, and a deformable energy absorbing member, and deforms the energy absorbing member by a load of an occupant on the webbing in the event of a vehicle emergency, thereby causing the winding shaft to move to the other position. A force limiter mechanism for rotating the webbing in a direction to pull out the webbing, and a sleeve provided on the winding shaft, the sleeve always rotating integrally with the winding shaft, and a substantially cylindrical shape. A driving member provided with a peripheral wall and surrounding the sleeve with the peripheral wall, the driving member being rotated in the one direction by the pretensioner mechanism; An inclined surface formed on the inner surface of the peripheral wall of the driving member and approaching the sleeve side toward the other direction side, provided between the sleeve and the inclined surface, the driving member being rotated in the one direction; A roller that is pressed against the inclined surface and engages with the sleeve when being provided, a lock ring that is provided in a substantially annular shape and surrounds the sleeve, and that holds the roller and always rotates with the roller; A restricting means provided on the lock ring, for restricting rotation of the lock ring in the other direction, when the drive member is rotated in the one direction by the pretensioner mechanism, While the roller engages with the sleeve to rotate the sleeve integrally with the driving member, the force limiter mechanism allows the sleeve to rotate through the winding shaft. When the sleeve is rotated in the other direction, the rotational force of the sleeve is transmitted to the drive member via the roller, the drive member is rotated by a predetermined angle in the other direction, and the lock is performed by the restricting means. The rotation of the ring in the other direction is restricted, whereby the pressing of the roller by the inclined surface is released, and the relative rotation of the sleeve with respect to the drive member is permitted.