JP2958041B2 - Seat belt clamping device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt clamping device, and more particularly, to a tooth profile structure of a clamping tooth in a clamping device.

2. Description of the Related Art Conventionally, as one form of a clamping device used for an ELR (emergency locking retractor) of a seat belt, a belt is press-contacted as disclosed in Japanese Patent Application Laid-Open No. 61-205532. There is a type of clamping between a surface and rotating teeth, and the rotating clamping teeth in such a clamping device are constituted by a large number of pyramidal teeth.

On the other hand, clamping teeth in a clamp device of a type in which a rotating tooth is rotated and pressed against a non-rotating tooth and a belt is sandwiched between the non-rotating tooth and the rotating tooth are disclosed in JP-A-63-22752 and JP-A-Hei. As shown in Japanese Patent No. 229746, the teeth are formed in a waveform, and the cross section of each tooth is a bilaterally symmetric mountain shape.

[Problems to be solved by the invention]

By the way, the clamping force or the clamping force of the seat belt differs depending on the shape of the clamping teeth.

SUMMARY OF THE INVENTION An object of the present invention is to improve the cross-sectional shape of a clamping tooth, thereby enabling a further increase in a clamping force and an improvement in a clamping force, and an improvement in reliability of a seat belt clamping device. It is.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a seatbelt for holding a seatbelt between rotating teeth rotating about an axis extending in a direction transverse to the seatbelt and non-rotating teeth opposed to the rotating teeth. In the clamping device, the tooth provided on the rotating tooth has a saw-tooth cross-sectional shape oriented in a tangential direction to the rotation locus of the tooth, and the tooth provided on the non-rotating tooth is the tooth provided on the non-rotating tooth. It has a shape corresponding to the tooth ridge.

[Action]

According to the present invention, when the tooth of the rotating tooth enters between the teeth of the non-rotating tooth, the tooth flank side of the non-rotating tooth and the rotating tooth depend on the degree of penetration of the rotating tooth corresponding to the thickness variation of the seat belt. The gap with the tooth flank side changes, but the degree of the change is substantially equal on both side surfaces sandwiching the tooth tips of both teeth.

〔Example〕

Next, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 is an exploded perspective view showing an example in which the present invention is applied to a pretensioner, FIG. 2 (a) is a right side view, FIG. 2 (b) is a rear view, and FIG. 2 (c) is a left side view. As shown in FIGS. 2 (a) to 2 (c), this device is configured by incorporating a pretensioner P and a retractor R into a common base unit 1.

As shown in detail in FIG. 1, the pretensioner P
A tooth shaft 2 forming non-rotating teeth, a rotary tooth 3 forming rotating teeth, a rotary plate 4 supporting one end thereof, a lock tooth 5 supporting the other end, and a pulley 6 screwed to an outer end surface of the rotary plate 4. , And a power source 7 and a cover 8 that constitute a rotation mechanism of the pulley 6.

The tooth shaft 2 is made of an aluminum alloy and has a long cylindrical shape. The tooth shaft 2 is provided with saw tooth-shaped clamp teeth 21 extending in the axial direction on a part of the circumferential surface of the tooth shaft 2. At both ends, mounting holes 41 and 51 for the rotary plate 4 and the lock tooth 5 are provided. The projections 22 and 23 are fitted into the projections.

The rotary tooth 3 is made of an aluminum alloy, extends radially from its axis, has a columnar shape having three plate-like angles 31, 32, and 33 arranged at an interval of approximately 45 ° from each other. Serrated clamp teeth 34 extending in the axial direction are provided on a part of the surface. At both ends, support shafts 35 and 36 that are supported by the support holes 42 and 52 of the rotary plate 4 and the lock teeth 5 via the plastic bearing bushes 43 and 53 are formed integrally.

The rotary plate 4 is a disk formed by stamping a steel plate, the mounting hole 41 and the support hole 42 are provided through the entire thickness of the plate, and an engaging pin 44 for positioning and connecting the pulley 6 and the pulley 6 is provided. It is protruding.

The lock tooth 5 is formed as a gear formed by stamping a steel plate, and the mounting hole 51 and the support hole 52 are provided through the entire thickness of the plate. External teeth 54 are formed. Hereinafter, a combination of the above members 2, 3, 4, and 5 will be referred to as a clamp unit.

The pulley 6 has a pin hole 61 that engages with the engagement pin 44 and a bottomed hole (not shown in the drawing) that engages with the projection 22. The pulley 6 is formed by joining two pressed steel plates, and is provided with a caulking portion 63 for caulking a pulling wire 72 connected to the power source 7 on a part of the peripheral surface, and includes a rotary plate 4 and a tooth shaft 2. It is fixed with screws.

The pretensioner P composed of these members is connected on the back side by a connecting frame 19 and on the front side by the reinforcing
The inner peripheral surfaces of the circular holes 11 and the tooth holes 12 formed on both side walls of the base unit 1 made of a box-shaped steel plate reinforced by 7, 18 are rotatably supported by the base unit 1 as rotation guide surfaces. The rotary blade 4 is supported via a self-lubricating plastic bearing bush 14, while the lock tooth 5 is formed in a tooth hole of the base unit 1.
It is supported with a moderate gap at 12. A bracket 15 for supporting the power source 7 and a mounting bracket 16 for attaching the base unit 1 to a vehicle body or the like are provided on one side wall of the base unit 1.

By the way, in the upper part of the inner peripheral surface of the tooth hole 12, a serrated internal tooth 13 which can engage with the serrated outer tooth 54 on the outer peripheral surface of the lock tooth 5 is formed over a central angle of about 180 °. (Refer to the side view of FIG. 2 (a) for the detailed shape of the internal teeth.) The tooth hole 12 formed with the internal teeth 13 and the lock tooth 5 formed with the external teeth 54 are formed.
And a lock mechanism of the pretensioner P.

On the other hand, a retractor R similar to the conventional ELR is incorporated below the base unit 1. The specific structure of the retractor and how to attach the retractor to the base unit 1 are the same as those of the related art, and thus the description is omitted.

In the device configured as described above, the webbing W of the seat belt is passed through and wound around the spool shaft of the retractor R as shown by a two-dot chain line in FIG.
1 and 2, reference numeral 8 denotes a plastic cover of the lock mechanism.
The notch 12 for inserting the clamp unit in the tooth hole 12
A receiving portion 81 that supports the outer periphery of the lock tooth 5 is provided so as to cover a, and engages with a hole formed in the end face of the projection 23 of the tooth shaft 2 to restrict rotation of the clamp unit in a normal use state. A soft pin shaft 82 is also provided integrally. Reference numeral 9 denotes a half-split clip that is fitted into a semi-circular hole opened above the base unit 1. The tip of the clip 9 is engaged with the tip of the This restricts the rotation of the rotary tooth 3 during use. Further, reference numeral 10 denotes a plastic belt guide through which the webbing W is inserted.

Next, the operation of the apparatus of this embodiment will be described with reference to FIG.
(B), a left side view of (c), and a side view for explaining the operation of the clamp member of FIG. 3 (refer to these figures). (See FIG. 1 for members that cannot be used.)

First, in the inoperative position, as shown in FIGS. 2 (a) and 3 (a), both clamp members 2, 3
The clamp teeth 21 and 34 are in an open state as shown in FIG. 3 (a).

In such a state, when a vehicle collision or the like is detected by the acceleration detecting means, the power source 7 responds to the signal in an extremely short time by the piston 71
By the operation of 70, before the forward movement due to the inertia of the human body starts, the wire 72 is pulled, and the pulley 6 rotates counterclockwise in FIG. 2 (c). The rotation of the pulley 6 is performed via the rotary plate 4 via the tooth shaft 2.
To Rotary Tooth 3 and to Rock Tooth 5.

Then, the restraint by the pin shaft 82 and the clip 9 is released, and the rotation of the rotary plate 4 causes the tooth shaft 2 fixed thereto to start rotating clockwise. On the other hand, the rotary tooth 3 has its plate-shaped angle 31 and the clamp teeth 34.
Are in the state along the webbing W, and revolve around the rotation center of the rotary plate 4 and the lock tooth 5 while being restrained from rotating, and move clockwise.

As the rotation of the rotary plate 4 progresses further and the amount of rotation of the tooth shaft 2 increases, the gap between the clamp teeth of both clamp members decreases, and the webbing W eventually becomes the clamp tooth as shown in FIG. 3 (b). It is sandwiched between 21,34. In this pinched state, the rotary tooth 3 is in a state where its rotation is restricted by the webbing W and the tooth shaft 2 this time, and accordingly, the webbing W
As shown in FIGS. 3 (c) and 3 (d), it is pulled downward and to the right while winding around the corners 31 to 33 of the rotary tooth 3, and finally reaches the retracted position shown in FIG. 3 (e). Reach. These series of operations are performed in a very short time, and the webbing W is retracted to the retractor side to remove the slack of the belt that is being fed through the through anchor.

As described above, when the pretension is applied to the webbing W, and the belt tension acts on the webbing W due to the forward movement of the human body due to the inertial force generated slightly later, the webbing W is pulled upward. Then, the clamp unit attempts to move upward due to the upward pulling force, but the plastic bearing bush of the circular hole 11 is formed on the rotary plate 4 side.
Since such a movement is not allowed by 14, only the lock tooth 5 side is pulled upward. Then, the external teeth of the lock tooth 5 become the internal teeth 13 of the tooth hole 12 of the base unit 1.
And a locked state in which counterclockwise rotation is restricted. At this time, the upward pulling force of the belt causes an action of self-locking the clamp device composed of the rotary tooth 3 and the tooth shaft 2, so that the belt is prevented from extending.

In this way, the pretensioner P can hold the pretension given to the webbing W. At this time, the clamping operation of the webbing W by the clamp teeth 21 and 34 is performed by referring to FIG. In the conventional clamp tooth shown in FIG. 2A, the tooth tangent C to the rotation trajectory of the tooth ridge of the rotary tooth about the axis O extending in the direction transverse to the seat belt is shown. opening angle theta ₁ is significant at one side of, ₂ theta opening angle becomes smaller at the other side surface side. In the case of such a tooth profile, when the rotating tooth rotates even a little from the expected position, the size of the gaps S ₁ and S ₂ between the tooth flank side surface of the rotating tooth and the non-rotating tooth greatly changes on the left and right. This means that the pinching force changes greatly with the variation in the thickness of the webbing to be pinched, and in extreme cases, the compression force acts only on one side of the tooth. On the other hand, in the case of the present embodiment in which the tooth profile of the rotating tooth is formed in a saw-tooth shape oriented in the tangential direction to the rotation locus of the tooth, the tangent C to the rotation locus of the tooth of the rotating tooth is obtained. respect, because equal and open angle theta _B of open angle theta _a and the other side of one side of the tooth, intended engagement opening angle theta _a be slightly rotated teeth from position and an open angle theta _B Does not change much. This means that there is little change in the clearance S _A : S _B between the tooth flank of the rotating tooth and the non-rotating tooth on both side surfaces of the tooth, and the compressive force acts evenly. The pinching force hardly changes with respect to the variation in the thickness.

Thus, according to this embodiment, the tightening force of the webbing by the clamp teeth is evenly distributed over the entire clamp portion, and the tightening force can be substantially increased.

As described above, the present invention has been described in detail based on one embodiment. However, the present invention is not limited to only the above-described embodiment, and may be applied to other types of clamp devices within the scope of the claims. It goes without saying that it is applicable.

〔The invention's effect〕

In the present invention, since the tooth profile of the rotating tooth is a saw-tooth profile that is directed tangentially to the rotation locus of the tooth ridge at the time of clamping, the belt breaking load is dispersed by dispersing the concentrated load on the seat belt webbing at the time of clamping. Therefore, there is an effect that the clamping force can be increased.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of one embodiment of the present invention, and FIG.
2 (b) is a rear view thereof, FIG. 2 (c) is a left side view thereof, FIG. 3 is a right side view showing an operation of the clamp mechanism, and FIG. 4 is a clamp tooth. FIG. 4 is a cross-sectional view showing the operation of the present invention in comparison with a conventional one. O… axis, C tangent, θ _A , θ _B … opening angle, P… pretensioner, R… retractor, W… webbing, 1… base unit, 2… as non-rotating teeth Tooth shaft, 3 ... Rotary tooth as rotating tooth, 4 ... Rotary plate, 5 ... Lock tooth,
6 ... pulley, 7 ... power source, 8 ... cover, 9
... detent clip, 10 ... belt guide, 11 ... circular hole, 12 ... tooth hole, 13 ... internal teeth, 14 ... bearing bush, 15 ... bracket, 16 ... mounting bracket, 17 ...
... Reinforcement frame, 18 ... Reinforcement frame, 19 ... Connection frame, 21 ... Clamp teeth, 22,23 ... Protrusion, 31,32,33 ...
… Plate angle, 34… Clamp teeth, 35,36 …… Support shaft, 41…
... Mounting hole, 42 ... Support hole, 43 ... Plastic bearing bush, 44 ... Engaging pin, 51 ... Mounting hole, 52 ... Support hole, 53 ... Plastic bearing bush, 54 ... Outer teeth, 61
... hole, 63 ... caulking part, 70 ... piston, 71 ... cartridge, 72 ... wire, 73 ... retaining block, 81
…… Receiving part, 82 …… Pin shaft

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shizuyo Tanaka 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside of Honda R & D Co., Ltd. (72) Yoshihiko Kinoshita 1-4-1 Chuo, Wako-shi, Saitama Pref. (72) Inventor Muneo Nishizawa 142-1 Kamakake, Hino-cho, Gamo-gun, Shiga Prefecture (56) References JP-A-1-229746 (JP, A) 58) Field surveyed (Int.Cl. ⁶ , DB name) B60R 22/42

Claims (1)

(57) [Claims] 1. A seat belt clamping device for clamping a seat belt between rotating teeth rotating about an axis extending in a direction transverse to the seat belt and non-rotating teeth opposed to the rotating teeth. The tooth provided on the tooth has a tooth profile with a sawtooth cross-section oriented in a tangential direction to the rotation locus of the tooth, and the tooth provided on the non-rotating tooth corresponds to the tooth of the rotating tooth. A seat belt clamping device having a shape.