JPH10278738A - Three-point seat belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wind and unwind a shoulder belt and a lap belt despite of a single belt retractor and apply a pretension by removing slack in the both belts by a single pretensioner. SOLUTION: A first spool for winding and unwinding a shoulder belt 2A and a second spool for winding and unwinding a lap belt 2B are provided in a housing of a belt retractor 1. These first and second spools are so set as being locked at emergency by a lock mechanism respectively and applied a pretension by simultaneously winding the slack in the shoulder belt 2A and the lap belt 2B by a pretensioner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-point seat belt device used for a vehicle such as an automobile.

[0002]

2. Description of the Related Art In a three-point seat belt device for a vehicle, it is desirable to be able to set optimum belt winding forces for a shoulder belt and a lap belt, respectively. For this reason, for example, U.S. Pat. As shown in Japanese Patent No. 881, there is known a structure in which a shoulder belt and a lap belt are respectively wound and unwound by dedicated belt retractors.

On the other hand, as a belt retractor, even if the seat belt is slack due to the occupant's clothes or the like,
When the occupant is restrained, it is desired to take this slack so that the occupant can be optimally restrained. For this reason, the belt retractor operates by receiving an operation signal at the time of a vehicle collision, and moves the spool in the belt winding direction. 2. Description of the Related Art A seat belt is slackened by being rotated, and a pretensioner for applying a pretension to the seat belt is provided.

[0004]

If dedicated belt retractors are used for the shoulder belt and the lap belt as described above, however, it is unavoidable that it is disadvantageous in terms of cost and layout. In order to optimally restrain the occupant in each of the belt and the lap belt, a dedicated belt retractor pretensioner must be additionally provided, which is disadvantageous in cost.

Therefore, according to the present invention, a function of winding and rewinding the shoulder belt and the lap belt can be obtained with one belt retractor, and an appropriate pretension is applied to the shoulder belt and the lap belt with one pretensioner. It is an object of the present invention to provide a three-point seat belt device capable of optimally restraining an occupant in a cost-effective manner.

[0006]

According to the present invention, a first spool for winding and rewinding a shoulder belt on a housing of a belt retractor and a second spool for winding and rewinding a lap belt are provided. At the same time, the first spool and the second spool are provided with lock mechanisms for preventing sudden withdrawal of the shoulder belt and the lap belt, respectively, and actuated by receiving an actuation signal at the time of a collision of the vehicle to operate the first spool and the second spool. It is characterized in that a pretensioner for applying pretension to the shoulder belt and the lap belt is provided by simultaneously rotating the first spool and the second spool in the belt winding direction.

According to a second aspect of the present invention, there is provided a pretensioner according to the first aspect of the present invention, wherein a gas generator which ignites by receiving an operation signal at the time of a vehicle collision to generate gas and a gas pressure generated by the gas generator. It is characterized by comprising a cylinder mechanism for operating the piston, and a drive transmission mechanism for converting a linear movement of the piston into a rotational movement and transmitting the rotation to the first spool and the second spool.

According to a third aspect of the present invention, the drive transmission mechanism according to the second aspect converts a linear motion of the piston into a rotary motion by a rack provided on the piston and a drive pinion meshed with the rack. A conversion mechanism is provided on each of the rotating shafts of the first spool and the second spool, and maintains a non-coupled state with these rotating shafts in a normal state. A clutch gear that is directly connected to rotate the first spool and the second spool in a belt winding direction, and a differential gear mechanism that transmits a rotational force of a drive pinion to clutch gears of respective rotating shafts of the first spool and the second spool. And is characterized by having.

[0009]

According to the first aspect of the present invention, the shoulder belt and the lap belt can be wound and unwound with a single belt retractor.
Pre-tensioning can be applied to these shoulder belts and lap belts by one pretensioner, so that the occupant can be optimally restrained in terms of cost and layout.

According to the second aspect, in addition to the effect of the first aspect, the pretensioner activates the piston of the cylinder mechanism by the cascade generator which is activated by the operation signal at the time of the collision of the vehicle. Since the first spool and the second spool can be instantaneously driven to rotate via the mechanism, the slack between the shoulder belt and the lap belt can be quickly wound up with good responsiveness and an appropriate pretension can be applied. it can.

According to the third aspect, in addition to the effect of the second aspect, a clutch gear is provided on each rotation shaft of the first spool and the second spool. The spool can freely rotate and rewind the belt, so that the function of the belt retractor will not be hindered.

In addition, since the driving force of the drive pinion is transmitted to these clutch gears via a differential gear mechanism, the shoulder belt wound on the first spool and the lap belt wound on the second spool Even if one of the spools is stopped to take up during the operation of the pretensioner due to the difference in the slack of the belt, the operation of the differential gear mechanism keeps the other spool in the take-up rotation, and Shoulder belt with two pretensioners,
Both lap belts can be completely slack.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 4, reference numeral 1 denotes a belt retractor for winding and rewinding the seat belt 2, and the belt retractor 1 is disposed in a lower portion of the center pillar CP.

A first spool 4 around which one end of the seat belt 2 is wound and a second spool 5 around which the other end of the seat belt 2 is wound around a housing 3 of the belt retractor 1, respectively, with respective rotating shafts 4a, 5a. It is rotatably provided in two upper and lower stages via.

The seat belt 2 is routed along the center pillars CP through a through ring 6 provided above the center pillars CP. The slutung 7 is loosely inserted into the portion between the two spools 5 and engages with the buckle 8 provided on the floor center side to function as the shoulder belt 2A and the lap belt 2B.

Between each end of the rotating shafts 4a and 5a of the first spool 4 and the second spool 5 and the housing 3, a rotational force in the belt winding direction is applied to the first spool 4 and the second spool 5. Spiral springs 9 and 9 as biasing return springs are provided, respectively, and an appropriate belt winding force is set on the first spool 4 and the second spool 5.

A lock mechanism 1 is provided between the other ends of the rotating shafts 4a and 5a and the housing 3 to prevent the shoulder belt 2A and the lap belt 2B from being suddenly pulled out.
0 and 10 are provided.

As the lock mechanism 10, a known emergency lock mechanism is used. When a predetermined deceleration occurs due to a collision of the vehicle, the deceleration is detected and the first spool 4 is detected.
The function of urgently locking the rotation of the second spool 5 in the belt rewinding (pulling out) direction, and the first spool 4 and the second spool 4 due to the inertial action of the inertia member when the shoulder belt 2A and lap belt 2B are suddenly pulled out. It also has a function of urgently locking the rotation of the spool 5 in the belt rewinding (drawing) direction.

The side of the housing 3 on the side where the spiral spring 9 is provided is activated by receiving an operation signal based on the sensing action of a collision sensor (not shown) at the time of a vehicle collision, and operates in response to the first signal. A pretensioner 11 for simultaneously rotating the spool 4 and the second spool 5 in the belt winding direction to take up slack between the shoulder belt 2A and the lap belt 2B and to apply a pretension to each of them.

As described above, the pretensioner 11 receives an operation signal at the time of a vehicle collision, and receives an igniter 12a.
Generator for generating gas by igniting gas
And the gas generated by the gas generator 12
Cylinder mechanism 13 for lowering 3a, piston 13
and a drive transmission mechanism 14 that converts the linear motion of “a” into rotary motion and transmits the rotation to the rotation shaft 4 a of the first spool 4 and the rotation shaft 5 a of the second spool 5.

The drive transmission mechanism 14 includes a drive direction conversion mechanism 15 that converts a linear motion of the piston 13a into a rotary motion by a rack 16 provided on the piston 13a and a drive pinion 17 meshed with the rack 16; Clutch gears 18 and 19 provided on the rotation shafts 4 a and 5 a of the first spool 4 and the second spool 5, and a drive pinion 17
And a differential gear mechanism 30 that transmits the rotational force of each of the clutch gears 18 and 19 to the clutch gears 18 and 19.

The clutch gears 18 and 19 maintain a non-coupled state with the rotary shafts 4a and 5a in a normal state, but the rotational force of the drive pinion 17 is transmitted through a differential gear mechanism 30. Then, the first and second spools 4 and 5 are directly connected to the rotating shafts 4a and 5a to rotate the first spool 4 and the second spool 5 in the belt winding direction. The rotating shafts 4a and 5a are held by the plurality of idle pinions 22 and 23. Gear bodies 20, 2 arranged concentrically and spaced apart on the outer circumference of
When the drive roller 1 rotates in one direction after being transmitted from the drive pinion 17, the clutch rollers 26 and 27 disposed in the cam grooves 24 and 25 on the inner circumference are pressed against the rotating shafts 4a and 5a to rotate with the gear bodies 20 and 21. The shafts 4a and 5a are directly connected.

More specifically, sleeves 28 and 29 are fixedly and non-rotatably fitted to the rotating shafts 4a and 5a, and serrations 28 provided on the outer peripheral surfaces of the sleeves 28 and 29 are provided.
When the clutch rollers 26 and 27 bite into the gear bodies 20 and 21 and the rotating shafts 4a and 5a, respectively.
Is connected directly.

On the other hand, the differential gear mechanism 30 is freely rotatably inserted into the pinion shaft 31 of the drive pinion 17 and engages with the gear bodies 20 and 21 of the clutch gears 18 and 19, and the pinion shaft 31. A pinion mate gear 35 rotatably supported by a pinion mate shaft 34 fixed in a state orthogonal to the shaft is provided integrally with the respective side surfaces of the side gears 32 and 33 so as to face each other, and meshed with the pinion mate gear 35. Crown gear 3
6, 37.

When the drive pinion 17 is rotated by the downward movement of the rack 16, the differential gear mechanism 30 is provided with a pinion mate gear 35 and crown gears 36, 37 supported by a pinion mate shaft 34 integrated with the pinion shaft 34.
, The side gears 32 and 33 rotate integrally with the pinion shaft 34, and the clutch gear 1
8 and 19, the driving force of the drive pinion 17 is transmitted, but there is a difference in the slack of the belt between the shoulder belt 2A and the lap belt 2B. For example, the shoulder belt 2A of the first spool 4 is wound first. When the take-up is stopped, the rotation of the side gear 32 is restricted by the clutch gear 18. However, the pinion mate gear 35 that rotates integrally with the pinion shaft 17 with respect to the side gear 32 rotates on the crown gear 36. Then, the rotation of the second spool 5 in the belt winding direction due to the rotation of the other side gear 33 and the clutch gear 19 is continued to reduce the slack of the shoulder belt 2A and the lap belt 2B by the first spool 4 and the second spool 5. Operates to take up completely.

Reference numerals 38, 39, and 40 in FIGS. 2 and 3 denote a housing plate that constitutes a gear housing for accommodating the drive transmission mechanism 14 including the respective gears on one side of the housing 3 of the belt retractor 1.

According to the structure of the above embodiment, the sheet S
When the occupant seated on the vehicle holds the slut tongs 7 to pull on the seat belt 2 and pulls the seat belt 2, the shoulder belt 2A and the lap belt 2B are pulled out from the first spool 4 and the second spool 5 of the belt retractor 1.

By pulling out the shoulder belt 2A and the lap belt 2B sufficiently and engaging the slutung 7 to the buckle 8, the winding force of the first spool 4 and the second spool 5 allows the shoulder belt 2A and the lap belt 2B to be pulled. Is wound up, shoulder belt 2
A and the lap belt 2B can be worn on the occupant with an appropriate winding force.

In the event of a vehicle collision, the lock mechanisms 10, 10 of the belt retractor 1 are locked, and the first spool 4
And the rotation of the second spool 5 in the belt withdrawing direction is locked urgently.

At the same time, the pretensioner 11 is operated in response to an operation signal from a collision detection sensor (not shown) to rotate the first spool 4 and the second spool 5 in the belt winding direction, and Since the pretension can be applied by taking up the slack of the shoulder belt 2A and the lap belt 2B caused by clothes and the like, the occupant can be optimally restrained by the shoulder belt 2A and the lap belt 2B.

As described above, according to the present invention, the shoulder belt 2A and the lap belt 2B can be wound and unwound by one belt retractor 1, and the pretensioners 11 attached to the belt retractor 1 Since a pretension can be applied to the shoulder belt 2A and the lap belt 2B to restrain the occupant optimally, the degree of freedom in the layout of the belt retractor 1 can be increased, and the number of parts can be reduced, which is advantageous in cost. Obtainable.

The pretensioner 11 operates a piston 13a of a cylinder mechanism 13 by a gas generator 12 which is operated by an operation signal at the time of a collision of a vehicle. Since the spool 4 and the second spool 5 can be driven to rotate instantaneously, the slack between the shoulder belt 2A and the lap belt 2B can be quickly taken up with good responsiveness and an appropriate pretension can be applied. .

In particular, the drive transmission mechanism 14 of the pretensioner 11 includes clutch gears 18 and 19 provided on the rotating shafts 4a and 5a of the first spool 4 and the second spool 5, respectively. The first spool 4 and the second spool 5 can freely rotate the belt and rewind the belt, so that the original function of the belt retractor 1 is not hindered in any small way.
9 is provided with a drive pinion 17 via a differential gear mechanism 30.
Is transmitted between the shoulder belt 2A wound around the first spool 4 and the lap belt 2B wound around the second spool 5, a difference occurs between the slacks of the respective belts. Even if one of the first spool 4 or the second spool 5 is in a winding stop state when the pretensioner 11 is operated, the other second spool 5 is actuated by the operation of the differential gear mechanism 30.
By maintaining the belt take-up rotation of the spool 5 or the first spool 4, even with one pretensioner 11, both the shoulder belt 2 </ b> A and the lap belt 2 </ b> B can be completely slack to perform optimal occupant restraint.

[Brief description of the drawings]

FIG. 1 is a layout diagram of an embodiment of a three-point seat belt device of the present invention.

FIG. 2 is a sectional view of the belt retractor of the embodiment.

FIG. 3 is an exploded perspective view of a pretensioner of the belt retractor according to the embodiment.

FIG. 4 is an exemplary sectional view showing a clutch gear of the drive transmission mechanism of the embodiment;

[Explanation of symbols]

 Reference Signs List 1 belt retractor 2A shoulder belt 2B lap belt 3 housing 4 first spool 4a rotating shaft 5 second spool 5a rotating shaft 10 lock mechanism 11 pretensioner 12 gas generator 13 cylinder mechanism 13a piston 14 drive transmission mechanism 15 drive direction conversion mechanism 16 rack 17 Drive pinion 18, 19 Clutch gear 30 Differential gear mechanism

Claims (3)

[Claims] 1. A first spool for winding and rewinding a shoulder belt on a housing of a belt retractor, and a second spool for winding and rewinding a lap belt, and the first spool and the second spool. And a lock mechanism for preventing sudden withdrawal of the shoulder belt and the lap belt, and actuating upon receiving an operation signal at the time of a collision of the vehicle, thereby simultaneously winding the first spool and the second spool. A three-point seat belt device, further comprising a pretensioner for applying a pretension to the shoulder belt and the lap belt by rotating in a direction. 2. A pretensioner, comprising: a gas generator for generating gas by igniting by receiving an operation signal at the time of a vehicle collision; a cylinder mechanism for operating a piston by gas pressure generated by the gas generator; 2. The three-point seat belt device according to claim 1, further comprising a drive transmission mechanism that converts the movement into a rotational movement and transmits the rotation to the first spool and the second spool. 3. A drive direction conversion mechanism for converting a linear motion of a piston into a rotary motion by a rack having a drive transmission mechanism provided on a piston and a drive pinion meshed with the rack, and each of a first spool and a second spool. The first spool and the second spool are provided on the rotating shaft, and maintain a state of being uncoupled from the rotating shaft in a normal state, and are directly connected to the rotating shaft when the rotational force of the drive pinion is transmitted. A clutch gear that rotates in the winding direction,
3. The three-point seat belt device according to claim 2, further comprising: a differential gear mechanism that transmits a rotational force of a drive pinion to clutch gears of respective rotation shafts of the first spool and the second spool.