JP3178489B2 - Safety belt retractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety belt retractor provided with a lock mechanism such as an emergency lock mechanism or an automatic lock mechanism.

[0002]

2. Description of the Related Art A retractor for a safety belt device of an automobile is provided to prevent a person seated in a seat from moving forward, but automatically retracts after a seated person wears a belt. An automatic lock mechanism (ALR) that only takes out and prevents the belt from being pulled out, and a lock mechanism that can be wound up and pulled out even after the belt is attached and is activated by a webbing sensor or vehicle sensor that operates in an emergency Some have an emergency lock mechanism (ELR) that prevents pulling out.

As such a conventional retractor for a safety belt, for example, the one shown in FIGS. 5 to 7 is known (as a similar technique, Japanese Utility Model Laid-Open Publication No. 63-145747,
See Japanese Utility Model Laid-Open No. 2-2264).

[0004] Reference numeral 1 denotes a housing having a U-shape.
A winding shaft 2 is rotatably supported on the housing 1 through both side walls 1a and 1b, and a ratchet wheel 3 is rotatably supported on the winding shaft 2 protruding from one side wall 1a. The inner end of a take-up spring (not shown) is connected to the other end of the take-up shaft 2 which is attached and protrudes from the other side wall 1b. 1b. A reel 5 penetrates and is supported by the winding shaft 2, and a webbing W having an end connected to the winding shaft 2 is wound around the reel 5.

The tip 6a is connected to the tooth portion 3 of the ratchet wheel 3.
A pawl 6 to be engaged with and disengaged from a is rotatably supported by a penetrating shaft 7 penetrating the housing 1, and a pin 8 protrudes from an end of the pawl 6. Further, a cam wheel 9 is rotatable in a webbing winding direction A and a webbing unwinding direction B via a center hole 9a at a small-diameter end portion 2a as an “one end” having a cut circular cross section of the winding shaft 2. The cam wheel 9 has an elongated hole 10 formed on the outer peripheral edge thereof for engaging the pin 8 of the pawl 6. This slot 1
Width D ₁ of the 0 is slightly larger than the diameter of the pin 8,
The pin 8 can move only in the longitudinal direction of the long hole 10, but cannot move in the width direction. Further, the cam wheel 9 is urged by a spring (not shown) to always rotate in the webbing winding direction A.

A tooth 11 is formed on the inner peripheral surface of the cam wheel 9, and a hook formed on a hook of a “webbing sensor” (not shown) is engaged with the tooth 11, and the tooth 11 is engaged with the webbing W. Only when a sudden pull-out force is applied, the cam wheel 9 is rotated in the webbing pull-out direction B against a spring (not shown). When the cam wheel 9 rotates in the webbing pull-out direction B, the long hole 10 of the cam wheel 9 draws the pin 8 and the tip 6 a of the pawl 6 is moved to the tooth portion 3 of the ratchet wheel 3.
a to lock the drawer of the webbing W (see FIG. 7). Thereafter, when the cam wheel 9 is rotated in the webbing take-up direction A by a spring (not shown), the elongated hole 10 separates the pin 8 and separates the pawl 6 from the ratchet wheel 3 (see FIG. 6). . In this manner, an emergency lock mechanism (ELR) that locks the webbing W only in an emergency when a sudden pulling force is applied to the webbing W is configured.

[0007]

However, in such a conventional technique, the long hole 10 of the cam wheel 9 is not provided.
And the width D ₁ of the can than the diameter of the pin 8 is slightly larger, pin 8 is movable only in the longitudinal direction of the elongated hole 10, since the movement in the width direction has become impossible, the cam wheel 9 and the ratchet Depending on the synchronization state with the wheel 3, as shown in FIG. 7, the tip 6a of the pawl 6 does not completely engage with the tooth bottom 3b of the ratchet wheel 3, and the engagement state is maintained with the gap S left. That is, the teeth 3 of the ratchet wheel 3
a has an invitation angle θ, the tip 6a of the pawl 6 attempts to move toward the tooth bottom 3b. However, since the pin 8 of the pawl 6 cannot move in the width direction of the long hole 10 as described above, The tip 6a does not reach the tooth bottom 3b. This state is an incomplete engagement of only the distal end portion of the tooth portion 3a of the ratchet wheel 3, and a sufficient locking effect may not be obtained.

The present invention has been made by paying attention to such a conventional technique, and provides a safety belt retractor in which the tip of the pawl is completely engaged with the tooth bottom of the ratchet wheel.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, a retractor for a safety belt according to the present invention has a ratchet wheel with a guiding angle for guiding the tip of a pawl to a tooth bottom and a cam wheel. The width of the slot is extended to the ratchet wheel side , and the pawl is
When moving from the engaged position to the disengaged position with the
Move the inner edge of the slot along which the ratchet
The gist is that it is formed obliquely linearly in a direction away from the center of the tool .

[0010]

[Function] Because the width of the long hole of the cam wheel has been expanded to the ratchet wheel side, when locking , the tip of the pawl that tries to go to the root at the invitation angle of the teeth of the ratchet wheel is securely guided to the root as it is. Can be. Therefore,
The tip of the pawl is completely engaged with the tooth bottom of the ratchet wheel, and a sufficient locking effect is obtained. And Paul
Moves from the engaged position to the disengaged position with the ratchet wheel.
The inner edge of the slot along which the pin moves when moving
Oblique straight line in the direction away from the center of the ratchet wheel
When the lock is released, the pawl pin
Oblique straight line in the direction away from the center of the wheel
It can be moved smoothly along the inner edge.
Therefore, the tip of the pawl is completely flush with the root of the ratchet wheel.
Even if it is fully engaged, it can be released smoothly and locked
Release can also be performed reliably.

[0011]

1 to 4 show a preferred embodiment of the present invention.
It will be described based on. In addition, the same reference numerals are given to portions common to the related art, and overlapping description will be omitted.

Reference numeral 12 denotes a long hole of this embodiment,
The position of 2b is the same as the conventional one, but the inner edge 12a is located closer to the ratchet wheel 3 than the conventional one. That is, the elongated hole 12 has a wide width D ₂ extended to the ratchet wheel 3 side.
The pin 8 is movable not only in the longitudinal direction but also in the width direction.

An invitation angle θ that forms an acute angle with respect to the radial direction of the ratchet wheel 3 is set on the side of the ratchet wheel 3 that engages with the pawl 6 of the tooth portion 3a,
If the tip 6a of the pawl 6 is slightly engaged with the tooth portion 3a, it can be guided to the tooth bottom 3b as it is.

Therefore, a sharp pull-out force is applied to the webbing, and the cam wheel 9 moves in the webbing pull-out direction B.
When the pin 8 of the pawl 6 rotates, the pin 8 of the pawl 6
It moves to the ratchet wheel 3 side along 2b, and its tip 6a is engaged with the tip of the tooth portion 3a of the ratchet wheel 3 (see FIG. 2). Once the tip 6a is engaged with the tooth portion 3a, as described above, the tip 6
a moves toward the tooth bottom 3b. In this case, a large width D ₂ of the long hole 12, the pin 8 of the pawl 6 is also movable in the width direction of the long holes 12, regardless of the synchronization state of the ratchet wheel 3 and the cam wheel 9, the pawl 6 The pin 8 moves from the outer edge 12b to the inner edge 12a in the elongated hole 12, and the tip 6a of the pawl 6 is completely engaged in the tooth bottom 3b of the ratchet wheel 3 (see FIG. 3). By completely engaging the tip 6a of the pawl 6 with the tooth bottom 3b in this manner, the engaging force is increased, and a sufficient locking effect can be obtained.

Thereafter, when the cam wheel 9 is rotated in the webbing winding direction A by a spring (not shown), the inner edge 12a of the elongated hole 12 separates the pin 8 and separates the tip 6a of the pawl 6 from the tooth portion 3a. Then, the engagement is released to return to the original state (FIG. 1).

In this embodiment, the inner edge 1 of the elongated hole 12 is
2a totally displaces the ratchet wheel 3 side, if only is adopted hole shape that is expanded in the longitudinal direction the entire range of the width D ₂ elongated hole 12, and guides the distal 6a of the pawl 6 to the tooth bottom 3b , As shown in FIG.
Only be good at a wide width D ₂ and the hole shape upper portion is considered. However, in this case, the inner edge 12a of the elongated hole 12 projects into the elongated hole 12, and the operation of returning the pin 8 of the pawl 6 to the original lower end portion cannot be performed smoothly, which is not preferable. However, if the oblique straight like a virtual inner edge 12c in FIG. 4, since the return movement of the pin 8 becomes smooth, to adopt a hole shape that only the upper end portion of the long hole 12 in the width D ₂ It is also possible.

[0017]

The retractor for a safety belt according to the present invention has the contents as described above. Since the width of the long hole of the cam wheel is expanded toward the ratchet wheel, the tooth portion of the ratchet wheel is locked when locked. The tip of the pawl, which is going to the root of the tooth at the invitation angle, can be reliably guided to the root of the tooth as it is. Therefore, the tip of the pawl is completely engaged with the tooth bottom of the ratchet wheel, and a sufficient locking effect can be obtained. And Paul is Ratchetto
When moving from the engaged position to the disengaged position
The inner edge of the slot along which the
Formed in a straight line diagonally away from the center of the tool.
When unlocking, lock the pawl pin with the ratchet wheel.
Along the inner edge of a straight line diagonally away from the center of the
Can be moved smoothly. Therefore, pow
Is fully engaged with the ratchet wheel root.
Even if it is, the engagement can be released smoothly and the lock can be released securely
I can do it.

[Brief description of the drawings]

FIG. 1 is an enlarged side view showing a main part of a safety belt retractor according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of a main part corresponding to FIG. 1, showing a state in which a tip end of a pawl is engaged with a tooth portion of a ratchet wheel.

FIG. 3 is an enlarged side view of a main part corresponding to FIG. 1, showing a state in which a tip end of a pawl is engaged with a tooth bottom of a ratchet wheel.

FIG. 4 is an enlarged view showing the shape of a long hole.

FIG. 5 is an exploded perspective view showing a main structure of a conventional safety belt retractor.

FIG. 6 is an enlarged side view of a main part of the retractor for a safety belt in FIG. 5;

FIG. 7 is an enlarged side view of a main part corresponding to FIG. 6, showing a state in which the tip of the pawl is engaged with a tooth portion of a ratchet wheel.

[Explanation of symbols]

Reference Signs List 1 housing 1a, 1b side wall of housing 2 winding shaft 3 ratchet wheel 3a tooth portion of ratchet wheel 3b tooth bottom 6 pawl 8 pin 9 cam wheel 12 long hole 12a inner edge 12b outer edge A webbing winding direction B webbing pulling direction D ₂ Slot width W Webbing θ Induction angle

Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60R 22/12-22/48

Claims (1)

(57) [Claims] 1. A rotatable take-up shaft for webbing winding is provided on both side walls of a housing, a ratchet wheel is provided at one end of the take-up shaft penetrating the side wall, and a tip is attached to a side wall near the ratchet wheel. A pawl to be engaged with and disengaged from the tooth portion of the ratchet wheel is rotatably supported and a pin is protruded from the pawl, and a cam wheel that is rotatable relative to the ratchet wheel is provided at one end of the winding shaft. The pawl pin is movably received on the outer peripheral portion of the cam wheel, and the pin is pulled by rotating the cam wheel in the webbing pull-out direction so that the tip of the pawl is engaged with the tooth portion of the ratchet wheel and the webbing winding direction. In the retractor for a safety belt, which has a long hole that separates the pin from the ratchet wheel by turning the pin away by turning to Serial tip of the pawl to the teeth of the ratchet wheel extends the width of the long hole of the cam wheel provided with an invitation angle leading to the tooth bottom to the ratchet wheel side, and the pawl is ratchet
When moving from the engaged position to the non-engaged position with the wheel
Ratchet the inner edge of the slot along which the pin moves
A retractor for a safety belt, wherein the retractor is formed obliquely linearly in a direction away from the center of the wheel .