JPH08192722A - Pretensioner for seat belt device - Google Patents

Abstract

PURPOSE: To make the winding-tightening of a webbing possible without synchronizing a winding shaft and its driving means by miniaturizing a pretensioner. CONSTITUTION: A pretensioner for a seat belt device has a winding shaft which is rotated aracl energized in the winding direction of a webbing 14; a casing 200 to form the flow-in port 205 of gas discharged from a gas generator; a rotary body 40 which is arranged in the casing and rotates unitedly with the winding shaft; and an actuating body 500 which is arranged in the casing and moved by gas pressure to engage with the rotary body. A deformable member 503 is interposed between the rotary body and the actuating body, and the gas generator functions to move the actuating body, and the rotary body engaging with the deformable body is thereby rotated to wind the webbing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretensioner for a seat belt device which restrains the forward movement of the occupant to a minimum by tightening the webbing of the seat belt worn by the occupant to remove the slack in a vehicle collision. More particularly, the present invention relates to a pretensioner for a seat belt device that rotates a take-up shaft of a seat belt retractor in a take-up direction by gas pressure to take up slack of a webbing on the take-up shaft and remove it.

[0002]

2. Description of the Related Art A vehicle seat belt device is designed to restrain an occupant with a webbing in the event of a vehicle collision. The webbing take-up device has a relatively weak take-up force in order to prevent the occupant from feeling the pressure of the webbing. As a result, when the seat belt is in use, there is a slight gap between the webbing and the occupant. Therefore, even if the pulling-out of the webbing from the winding device is stopped at the time of a vehicle collision, it is expected that the occupant will move in the collision direction by this gap before the occupant is reliably restrained by the webbing.

Therefore, there is provided a pretensioner for a seat belt device that tightens the webbing to remove the slack in the event of a vehicle collision. Conventionally, this type of pretensioner operates a gas generator in an emergency, and this gas pressure causes the take-up shaft of the seat belt retractor to rotate in the take-up direction, so that the slack of the webbing is removed from the take-up shaft of the retractor. There is something to wind up and remove. As such a pretensioner, the one described in JP-A-1-306345 is known. This is a drive pulley in which a pulling wire pulled by the operation of a gas generator is wound several times, and a rotation drive means for tensioning in which a pair of meshing claws are eccentrically mounted rotatably in the drive pulley. , With a meshing ring having internal teeth facing the meshing claw and rotating integrally with the webbing take-up shaft, the meshing claw pivots and meshes with the centrifugal force by the rotation of the drive pulley due to the operation of the gas generator. It is configured to mesh with the ring and wind the looseness of the webbing around the winding shaft.

[0004]

In the above-mentioned conventional example, the gas pressure transmitting mechanism has a structure in which the drive pulley is rotated by the pulling wire, and the pulling wire connected to the piston in the cylinder is used to generate the explosive force by the explosive. It was a method of using and pulling out. Therefore, it is necessary to provide a cylinder for accommodating the piston, so that the cylinder is large in size. Also, the tow wire
Since a large pulling force is required, a thick and highly rigid one has been required. Furthermore, it is not possible to use a drive pulley having a small diameter for winding the pulling wire, and in order to secure a predetermined pull-in amount, there is a drawback that the size of the device increases as the amount of explosive increases. Was there.

Further, a pair of engaging claws which are eccentrically mounted rotatably in the drive pulley are provided as the rotational drive means for tensioning, and one of the engaging claws is configured to mesh with the engaging ring for emergency operation. A clutch mechanism is provided to connect with the take-up shaft only when necessary. However, it is difficult to set synchronization between the meshing claw and the meshing ring, and there is a risk that the timing of meshing between any one of the meshing claws and the meshing ring may be delayed, or both meshing claws may not mesh with the meshing ring. Further, since the rotational speed during operation is very high, there is a possibility that the meshing claw may bounce back due to collision between the tooth tips of the meshing claw and the meshing ring, and the meshing claw may not mesh with the meshing ring.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to reduce the size of the winding shaft and the driving means for the winding shaft. It is an object of the present invention to provide a pretensioner for a seat belt device that can wind up a sufficient amount of webbing in an emergency without the need to synchronize with.

[0007]

In order to achieve the above object, a pretensioner for a seat belt device according to the present invention is discharged from a take-up shaft that is rotationally biased in a webbing take-up direction and a gas generator. A casing having a gas inlet, a rotating body arranged in the casing and rotating integrally with the winding shaft, and an operating body arranged in the casing and moved by gas pressure to engage with the rotating body. The deformable member is interposed between the rotating member and the actuating member, the actuating member is moved by the operation of the gas generator, and the rotating member engaging with the deforming member is rotated to wind the webbing. There is.

Further, a tooth-shaped projection is formed on one of the engaging surfaces of the rotating body and the operating body, and a deforming member is provided on the other engaging surface. The deformable member is made of hard resin or metal material. Further, the deformable member is formed in a hollow cylindrical shape. Furthermore, a deformable member is provided on the actuating body, and a locking projection that abuts against the end of the deformable member is formed at the lower end of the actuating body. In addition, a recessed portion is formed on the side opposite to the engaging surface of the actuation body,
A roller is interposed between the recess and the side wall of the casing. Furthermore, the casing and the operating body are formed in an arcuate cross-section that curves toward the rotating body.

[0009]

When the gas generator operates in an emergency, gas is supplied into the casing through the gas inlet. Then, due to this gas pressure, the operating body moves in the casing and engages with the rotating body. The actuating body and the rotating body are securely engaged in any state by the deformation of the deformable member interposed therebetween, and the rotating body rotates. The rotation of the rotating body causes the winding shaft connected to the rotating body to rotate, so that the webbing can be securely tightened.

When a tooth-like projection is formed on one of the engaging surfaces of the rotating body and the operating body and a deforming member made of hard resin or a deformable metal material is provided on the other engaging surface, the tooth-like projection is formed. Bites into the deformable member, so that the actuating member and the rotating member are engaged more reliably. Further, when the deformable member is formed in a hollow cylindrical shape, the central portion thereof is close to the rotating body, so that the deformable member is reliably engaged with a small force in the initial stage of engagement, and the protrusion of the deformable member to the outside due to crushing is reduced. be able to. Furthermore, if a deformable member is provided on the actuating body and a locking projection that abuts against the end of the deformable member is formed on the lower end of the actuating body,
The shearing force acting on the deformable member is received by the locking projection. The movement of the actuating body is stopped by the engagement of the locking projection with the rotating body, so that the actuating body can be prevented from jumping out. Further, due to the engagement between the rotating body and the operating body, the side portion of the operating body opposite to the engaging surface is pressed against the side wall of the casing, but a concave cutout is formed in the side portion of the operating body. By interposing a roller between the cutout portion and the side wall of the casing, the sliding resistance of the operating body can be reduced. Furthermore, if the casing and the actuation body are formed in an arcuate cross-section that curves toward the rotating body, the overall size of the device can be reduced, and
It is possible to increase the distance of engagement with the rotating body for transmitting the rotational force more reliably.

[0011]

EXAMPLES Examples will be described with reference to the drawings. 1 is a front view of the inside of the device, FIG. 2 is a side sectional view of the main part of the device, FIG. 3 is an exploded perspective view of the main part of the device, and FIG. 4 is a front view of an initial state inside the device. FIG. 5 is a front view of the inside of the apparatus when the webbing tightening is completed.

Reference numeral 10 denotes a housing having a U-shaped cross section. The housing 10 is a back plate 11 attached to the vehicle body.
And both side plates 12 and 12 facing each other. 13 is
A winding shaft for rotatably supporting the webbing 14 of the seat belt, which is rotatably supported by the central portions of the side plates 12, 12. The winding shaft 13 is rotationally biased in a direction of winding the webbing 14 around the outer circumference. One end of the take-up shaft 13 is formed in a square shaft shape.

Reference numeral 20 is a casing attached to the housing 10. The casing 20 includes a rear wall 21 and
It is composed of a side wall 22 formed upright from the peripheral edge of the back wall 21 and a casing cover 23. A through hole 24 is provided in the center of the back wall 21. A gas inlet 25 is formed at the lower end of the back wall 21 to allow the gas discharged from the gas generator 30 to flow into the casing 20. On the side wall 22 at the upper end of the casing 20,
A gas vent hole 26 is formed for venting gas.

Reference numeral 40 denotes a rotating body rotatably supported by the casing 20. The rotating body 40 has a cylindrical base end portion 41 fitted into the through hole 24 of the casing 20. The rotary body 40 is connected to the take-up shaft 13 by fitting one end of the take-up shaft 13 formed in an angular shaft shape into a square hole (not shown) provided in the base end part 41, It rotates integrally with the winding shaft 13.

The central portion of the rotating body 40 is a portion arranged inside the casing 20, and a tooth-like projection 42 is formed on the outer periphery thereof. Further, the tip end portion 43 of the rotating body 40 is formed in a columnar shape, and is fitted into the through hole 27 provided in the casing cover 23. An angular shaft portion 44 is formed at the tip end portion 43 of the rotating body 40 protruding from the casing cover 23. The angular shaft portion 44 urges the winding shaft 13 to rotate in the winding direction of the webbing 14 to rotate the spring. Unit 15
Is fitted to.

Reference numeral 50 denotes an actuating member which is arranged in the casing 20 and which moves by gas pressure and engages with the rotating member 40. 51 is an actuation body 5 on the side opposite to the engaging surface with the rotating body 40.
0 is a concave cutout formed on one side. Between the one side surface of the recessed portion 51 and the stop projection 28 formed on the side wall 22 at the center of the casing 20, a plurality of actuating bodies 50 are smoothly moved by the operation of the gas generator 30. Rollers 52 are provided.

A deformable member is interposed between the rotating body 40 and the operating body 50. In this embodiment, the recessed portion 5
A deformable member 53 made of a hard resin such as urethane or elastomer that is not easily deformed is fixed to one side portion (engaging surface with the rotating body 40) of the actuation body 50 on the side opposite to 1. The hard resin used for the deformable member 53 preferably has a Shore A hardness of 70 or more, and more preferably 85 or more.

Reference numeral 54 is a protrusion formed on one side of the actuation body 50 in order to prevent the deformable member 53 from coming off easily. The protrusion 54 is buried by the deformable member 53 so that the tooth tips cannot be seen. The width of the actuation body 50 and the deformable member 53 may be formed to be slightly smaller than the width between the side wall 22 of the casing 20.

Then, as shown in FIGS. 1 and 4, in the initial state, the operating body 50 is disposed at a position where it does not engage with the rotating body 40. It is preferable that the distal end portions of the actuation body 50 and the deformable member 53 are formed to be inclined so that the actuation body 50 and the rotating body 40 can be easily engaged with each other, since the engagement gradually increases at the time of engagement.

When the gas generator 30 is operated, as shown in FIG. 5, the pressure of the gas flowing in from the gas inlet 25 moves the actuation body 50 from the position indicated by the broken line to the position indicated by the solid line. At this time, the deformable member 53 causes the tooth-shaped projections 4 of the rotating body 40 to move.
The rotary body 40 is rotated while engaging with 2 and deforming. As a result, the winding shaft 13 connected to the rotating body 40 rotates, and the webbing 14 is tightened. During this time, the operating body 50 is pressed against the side wall 22 by the rotating body 40, but can smoothly move because the roller 52 is interposed.

In the above embodiment, the tooth-like protrusions 42 are formed on the rotating body 40, but if sufficient frictional force can be obtained between the rotating member 40 and the deformable member 53 fixed to the actuating body 50, the tooth-like protrusions 42 can be formed.
Need not be formed. Further, in the above embodiment, the one in which the deformable member 53 is fixed to the actuation body 50 is illustrated, but
Instead of fixing the deformable member 53 to the actuation body 50, the deformable member may be fixed to the rotating body 40. Also, the rotating body 4
The deformable member may be fixed to both 0 and the actuation body 50. Further, the rotating body 40 and the actuating body 50 themselves may be formed of a deformable member.

Next, a second embodiment according to the present invention will be described with reference to the drawings. 6 is an exploded perspective view of the second embodiment, FIG. 7 is a front view of an actuation body of another embodiment, FIG. 8 is a cross-sectional view of an essential part of the second embodiment in an initial state, and FIG. 9 is a completed webbing tightening operation. It is sectional drawing of the 2nd Example principal part. Housing 10, gas generator 30, and rotating body 40
May be configured similarly to the first embodiment.

The casing 200 attached to the housing 10 comprises a rear wall 201, a side wall 202 and a casing cover 203. The rear wall 201 and the casing cover 203 have through-holes 20 at the center.
4,207 are provided. A gas inlet 205 is formed at the lower end of the back wall 201 to allow the gas discharged from the gas generator 30 to flow into the casing 200.

The rotating body 40 has a base end portion 41 at the through hole 20.
4, the tip end portions 43 are fitted into the through holes 207, respectively, and are rotatably supported by the casing 200. The rotary body 40 has a base end portion 41 connected to the winding shaft 13 and an angular shaft portion 44 formed on the tip end portion 43 fitted to the mainspring spring unit 15, and is integrated with the winding shaft 13. Rotate to.

Actuator 5 arranged in casing 200
00, the concave groove 5 is formed in the longitudinal direction on the side of the engaging surface with the rotating body 40.
05 is formed. Further, at the lower end of the actuation body 500, a locking projection 506 is formed to project on the side of the groove 505 in order to ensure airtightness.

In the groove 505, the tooth-like projections 4 of the rotating body 40 are formed.
The deformable member 503 that engages with 2 is locked. The lower end of the deformable member 503 is in contact with and supported by the locking projection 506. The deformable member 503 deforms and meshes in accordance with the engagement with the tooth-like protrusion 42, and is made of hard resin, copper, or
It is made of a deformable metal material such as aluminum or lead.

When the deforming member 503 is formed in a hollow cylindrical shape, the area of contact with the tooth-like projection 42 at the time of engagement is gradually increased, which is preferable. Further, it is preferable to form the inclined portion 507 at the tip of the deformable member 503, because it facilitates engagement with the rotating body 40 and gradually increases engagement during engagement.

Further, as shown in FIG.
May have a honeycomb-shaped concave portion 508 formed on the engaging side portion with the rotating body 40 and inside thereof. When the actuation body 500 is formed in this manner, the actuation body 500 is also deformed and meshed in accordance with the engagement with the tooth-like protrusion 42. In this case, the actuation body 500 acts as a deforming member.

When the gas generator 30 operates, the actuation body 500 and the deformable member 503 move due to the pressure of the gas flowing from the gas inlet 205, as shown in FIG. At this time, the deformable member 503 engages with the tooth-shaped projections 42 of the rotating body 40 to deform and rotate the rotating body 40. as a result,
The winding shaft 13 connected to the rotating body 40 rotates, and the webbing 14 is tightened. In addition, the operating body 500
The locking projection 506 at the lower end of the engaging member engages with the rotating body 40 and stops the movement of the actuating body 500.

Next, a third embodiment according to the present invention will be described with reference to the drawings. FIG. 10 shows the third state in the initial state.
FIG. 11 is a sectional view of an essential part of the embodiment, and FIG. 11 is a sectional view of an essential part of the third embodiment when the webbing tightening is completed. In the third embodiment, the casing 210, the actuator 510, and the deformable member 5 are used.
The structure is the same as that of the second embodiment except that 13 has an arcuate cross section.

That is, the casing 210 has a rear wall 211.
And a side wall 212 curved in an arc shape toward the rotating body 40.
And a casing cover (not shown). Through holes (not shown) are provided in the central portions of the back wall 211 and the casing cover, respectively. A gas inlet 215 is formed at the lower end of the back wall 211 to allow the gas discharged from the gas generator 30 to flow into the casing 210.

The rotating body 40 has a base end portion 41 at the through hole 21.
4, the front end portions are fitted into the through holes of the casing cover, and are rotatably supported by the casing 210. The rotating body 40 has a base end portion connected to the winding shaft 13 and an angular shaft portion formed at the tip end portion 43 fitted into the mainspring spring unit 15 so as to rotate integrally with the winding shaft 13. To do.

Actuator 5 disposed in casing 210
Reference numeral 10 is formed by curving toward the rotating body 40 side in an arc shape similar to the curvature of the side wall 212. And the operating body 51
0 is a concave groove 51 in the longitudinal direction on the engagement surface side with the rotating body 40.
5 is formed. In addition, at the lower end of the actuator 510,
In order to ensure airtightness, the locking projection 51 is provided on the concave groove 515 side.
6 is formed to project.

In the concave groove 515, the tooth-like projections 4 of the rotating body 40 are provided.
The deformable member 513 that engages with 2 is locked. The deforming member 513 is also formed by curving toward the rotating body 40 side in an arc shape similar to the curvature of the side wall 212. The lower end of the deformable member 513 is supported by abutting the locking projection 516.

The deformable member 513 is made of a material such as a hard resin or a deformable metal material such as copper, aluminum or lead. When the deformable member 513 is formed in a hollow cylindrical shape, the area of contact with the tooth-like protrusions 42 at the time of engagement is gradually increased, which is preferable. Further, it is preferable to form the inclined portion 517 at the tip end of the deformable member 513, because it facilitates the engagement with the rotating body 40 and the engagement gradually increases during the engagement.

When the gas generator 30 operates, as shown in FIG. 11, the actuation body 510 and the deformable member 513 move due to the pressure of the gas flowing from the gas inlet 215. At this time, the deformable member 513 engages with the tooth-shaped projections 42 of the rotating body 40 to deform and rotate the rotating body 40. Since the deformable member 513 is curved and formed in an arc shape, the engaging distance with the rotating body 40 increases, and if the contact distance is the same as in the second embodiment, the device itself can be downsized. . Due to the engagement of the deformable member 513 and the rotating body 40, the winding shaft 13 connected to the rotating body 40 rotates, and the webbing 14
Will be tightened.

Thus, in the present invention, since the webbing can be wound without depending on the meshing of gears, the synchronization setting and the meshing timing are not taken into consideration,
The pretensioner of the seat belt device can be easily manufactured. After the webbing 14 is tightened, the webbing 12 may be prevented from being pulled out by a known ELR (emergency lock retractor) or ALR (automatic lock retractor) locking mechanism.

[0038]

The present invention is configured as described above, and the deforming member is deformed according to the shape of the rotating body by interposing the deforming member in the engaging portion between the rotating body and the actuating body. It is possible to ensure reliable engagement in any state. Further, when the tooth-like projection is formed on one of the engaging surfaces of the rotating body and the operating body and the deforming member is provided on the other engaging surface, the tooth-like projection bites into the deforming member, and the operating body and the rotating body Can be engaged more reliably. When a hard resin or a metal material is fixed as a deformable member to the engagement surface of either one of the operating body and the rotating body, these materials deform and engage with each other. Also in this case, the engagement can be surely performed, and the webbing can be surely tightened. Further, when the deformable member is formed in a hollow cylindrical shape, the central portion thereof is close to the rotating body, so that the deformable member is reliably engaged with a small force in the initial stage of engagement, and the protrusion of the deformable member to the outside due to crushing is reduced. be able to. Further, when a deformable member is provided on the actuating body and a locking projection that abuts against the end of the deforming member is formed at the lower end of the actuating body, the shearing force acting on the deforming member is received by the locking projection. Further, the movement of the actuating body is stopped by the engagement of the locking projection with the rotating body, so that the actuating body can be prevented from jumping out. Further, by interposing the roller between the side portion of the operating body on the side opposite to the engagement surface with the rotating body and the side wall of the casing, the sliding resistance of the operating body can be reduced. Furthermore, if the casing and the actuating body are formed in an arcuate cross-section that curves toward the rotating body, the overall size of the device can be reduced, and the distance with which the rotating body is engaged for more reliable transmission of rotational force. Can be increased.

As described above, according to the present invention, the engagement between the actuating member and the rotating member does not depend on the meshing of the gears. Therefore, the seat belt device can be operated without considering the synchronization setting or the meshing timing. The pretensioner can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a front view of the inside of the apparatus.

FIG. 2 is a side sectional view of a main part of the apparatus.

FIG. 3 is an exploded perspective view of a main part of the apparatus.

FIG. 4 is a front view of an initial state inside the device.

FIG. 5 is a front view of the inside of the apparatus when the webbing tightening is completed.

FIG. 6 is an exploded perspective view of the second embodiment.

FIG. 7 is a front view of an actuator according to another embodiment.

FIG. 8 is a sectional view of an essential part of a second embodiment in an initial state.

FIG. 9 is a cross-sectional view of the essential parts of the second embodiment upon completion of webbing tightening.

FIG. 10 is a sectional view of an essential part of the third embodiment in the initial state.

FIG. 11 is a cross-sectional view of the essential parts of the third embodiment upon completion of webbing tightening.

[Explanation of symbols]

 13 Winding shaft 14 Webbing 20, 200, 210 Casing 22, 202, 212 Casing side wall 25, 205, 215 Gas inlet 30 Gas generator 40 Rotating body 42 Teeth 50, 500, 510 Actuator 51 Recessed portion 52 rollers 53, 503, 513 deforming members 506, 516 locking protrusions

Claims (7)

[Claims] 1. A take-up shaft that is urged to rotate in the webbing take-up direction, a casing that forms an inflow port for gas discharged from a gas generator, and is disposed inside the casing and is integral with the take-up shaft. The rotating body that rotates around and the operating body that is arranged in the casing and moves by gas pressure to engage with the rotating body. The deformable member is interposed between the rotating body and the operating body to operate the gas generator. A pretensioner for a seat belt device, wherein the actuating member is moved by the rotating member and the rotating member that engages with the deformable member is rotated to wind up the webbing. 2. The seat belt device according to claim 1, wherein a tooth-shaped projection is formed on one of the engaging surfaces of the rotating body and the actuating body, and a deforming member is provided on the other engaging surface. Pretensioner. 3. The pretensioner for a seat belt device according to claim 1, wherein the deformable member is made of a hard resin or a metal material. 4. The pretensioner for a seat belt device according to claim 2, wherein the deformable member is formed in a hollow cylindrical shape. 5. The deformable member is provided on the actuating body, and a locking projection is formed at the lower end of the actuating body so as to abut the end of the deformable member. Seat belt device pretensioner. 6. A concave cutout is formed on a side portion of the actuation body opposite to the engagement surface, and a roller is interposed between the concave cutout and a side wall of the casing. 1, 2, 3,
A pretensioner for a seat belt device according to item 4 or 5. 7. The pretensioner for a seat belt device according to claim 1, wherein the casing and the actuation body are formed in an arcuate cross-section that curves toward the rotary body.