JPS6118542A - Emergency lock retractor - Google Patents

Abstract

PURPOSE:To make engaging action smooth by forming the tapering-shape tooth edge of engaging part between an acceleration detecting mechanism and a locking mechanism of webbing winder. CONSTITUTION:A mechanism to sense acceleration of a car body is located under a latch frame 11. This sensing mechanism comprises a weight 13 and a sensor arm 12. When an impact is given, the weight 13 inclines by inertia, the sensor arm 12 is turned clockwise by the cam effect of a spherical concavity 13b and the tooth 12b formed at its end engages the ratchet tooth 11a of the latch frame 11 and stops the rotation. The tooth 12b has a tapering shape which is tapered toward the tip in width. Accordingly, the overlapped width L2 of the edges of ratchet tooth 11a and the tooth 12b is made small.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a webbing retractor with an emergency locking mechanism for vehicles such as aircraft and automobiles, and more particularly to a body-sensing emergency locking retractor.

In Fig. 1a and Fig. 1b, which is a view taken in the direction of the arrow, the webbing engages with the tooth tips of the latch frame 1 connected to the shaft (not shown) around which the webbing is wound, thereby preventing its rotation. The tooth tips of the sensor arm 2 are normally set to abut in parallel to each other. However, in reality,
Manufacturing of each part.

Due to machining errors, it is not uncommon for the tips of the teeth to intersect and abut at an angle α, as shown in FIG. 1b.

If the tooth tips come into contact in this condition, the sensor arm 2 will not smoothly enter the teeth of the latch frame 1, and in some cases, there is a risk that both or one of the tooth tips may break off. be. In order to achieve smooth engagement even when the tips of the teeth intersect in this way, it is desirable that the overlapping width L□ between the tips of the teeth be smaller.

On the other hand, when the sensor arm 2 jumps in to prevent the rapid rotation of the latch frame 1, a considerable impact is generated. Therefore, it is required to ensure a wide contact area between the teeth of the latch frame 1 and the sensor arm 2 to reduce the pressure applied to the latch frame 1 and the sensor arm 2, respectively.

The present invention has been made in view of the above points, and the present invention has been made in view of the above points. The purpose is to provide a lock retractor.

Hereinafter, the configuration of the present invention will be explained based on specific examples. FIG. 2 is an exploded perspective view showing a vehicle body sensing type emergency lock retractor as one embodiment of the present invention. The spool 3 for winding up the webbing W is formed by flanges 3b fixed to both ends of a cylinder 3a around which the webbing W is wound, and is externally fitted onto the retractor shaft 4 so as to be able to rotate integrally with the cylinder 3a. Webbing W is attached to the retractor shaft 4.
One end of is locked. The retractor shaft 4 is inserted into large and small insertion holes 5b and 5c formed in opposing side plates 5a and 5a of a U-shaped retractor base 5, for example, and is rotatably supported. . A large number of lock teeth 5d are erected at predetermined positions around the side plate 5a in which the large insertion hole 5b is formed.

At the end of the retractor shaft 4 protruding from the small holding hole 5c, there is a take-up spring 6 that urges the retractor shaft 4 and the spool 3 to rotate in the direction of winding the webbing W.
is installed. The winding spring 6 is covered with a bowl-shaped case 7. Both ends of the take-up spring 6 are locked at appropriate positions on the inner peripheral surfaces of the retractor shaft 4 and the case 7, respectively.

A latch plate 8 provided with ratchet teeth around the entire circumference is fitted to the other end of the retractor shaft 4 formed in an oval cross section so as to be rotatable therewith.

As shown in FIG. 3, the latch-up spring 9 has three spring portions 9a evenly formed locally on the front end (outside) surface of the latch plate 8 with respect to the retractor shaft 4, as shown in FIG. are mounted so that they can rotate together.

In this case, the latch-up spring 9 is provided with an appropriate number of locking protrusions 9b and claws 9C, and these are locked or engaged with the corresponding tooth bottoms or recesses of the launch plate 8, so that the latch-up spring 9 can be mounted reliably and easily. . A latch ring 10 is attached to the outside of the latch-up spring 9 so as to be rotatable therewith. In the latch ring 10 of this example, the local area is
Engagement pieces 10a are provided protrudingly at equally divided positions, and each engagement piece 10
A plurality of L-shaped teeth 10b are spaced apart from each other by an appropriate length. The distance between the L universes 10b is set to be large enough to allow the ends of the three spring parts 9a of the latch-up spring 9 to fit together, and the other parts are set to have the same dimensions. . Therefore, the position of the latch ring 10 with respect to the latch plate 8 can be accurately determined by appropriately interposing the latch-up spring 9. That is, if the latch ring 10 is always pressed toward the center (inside) of the shirt 1 along the axial direction of the shirt 4, each space 1. It can be mounted at a position where Ob can smoothly enter and engage between the ratchet teeth 88 of the latch plate 8.

Furthermore, a latch frame 11 as a gear member is attached to the outside of the latch ring 10 so as to be independently rotatable by a predetermined angle. The latch frame 11 of this example is made of resin, and an annular groove 11a for accommodating the latch ring 10 is formed on the back side facing the latch ring 10, as shown in FIG. The latch ring 1 has three notches 11b each having a cam surface C.
They are evenly carved in correspondence with the engagement pieces 10a of 0. On the other hand, on the front side, there are many ratchet teeth all around the circumference.
1c are evenly provided. In addition, the bolt lie is screwed into the end of the shaft 4 from the side of the latch frame 11 with its center hole lid being screwed into the end of the shaft 4 by the appropriate amount.
movement to the outside is prevented. The latch frame 11 formed in this manner is rotatably inserted onto the tip of the shaft 4 with each engagement piece 10a of the latch ring 10 loosely fitted into each notch 11b. Therefore, under normal conditions, the latch frame 11 is engaged with the engagement piece 10a and rotates together with the latch ring 10, shaft 4, etc., but when the rotation of the latch frame 1111 is prevented, the engagement piece 10a is rotated on the cam surface. C, the latch ring 10 rotates relative to the latch frame 11 by a predetermined angle (rotation delay of the latch frame 11 occurs), and the latch ring 10 rotates inward against the elastic force of the latch-up spring 9. is moved a predetermined distance toward.

Returning to FIG. 2, a sensing mechanism is provided below the latch frame 11 that senses acceleration of the vehicle body due to a collision or the like and prevents the latch frame 11 from rotating in response. The sensing mechanism of this example includes a weight 13 as a sensing member that is swingably supported by an external force such as an inertial force, and a way 1.
The sensor arm 12 is supported as a pawl member and is supported so as to be able to reciprocate up and down in accordance with the swinging motion of -13. As shown in FIG. 5a, the weight 13 is placed with its bottom protrusion 13a loosely fitted into a hole 14a at the bottom of the housing 14 so as to be swingable in all directions, front and rear, right and left. weight 13
A spherical recess 13b is formed in the head of the sensor arm 12, and the spherical tip of the foot 12a of the sensor arm 12, which is rotatably supported via a shaft 15, comes into contact with this spherical recess 13b. Supported. The sensor arm 12 is similarly made of resin, and has a tooth portion 12b that can engage with the ratchet tooth 11a of the latch frame 11 at its tip. Therefore, under normal conditions, as shown in FIG.
However, in the event of an emergency such as a collision, the weight 13 will tilt due to inertia as shown in Figure 5b.
The sensor arm 12 rotates clockwise due to the cam effect of the spherical surface of the four portions 13b, and its tip tooth portion 12b engages with the ratchet teeth 11a of the latch frame 11 to prevent its rotation.

The tips of the tooth portions 12b of the sensor arm 12 are formed in the shape shown below to smoothly and reliably mesh with the ratchet teeth 11a. FIG. 6a is a plan view showing the sensor arm 12 of this example, and FIG. 6b is an elevational view thereof. As shown in FIG. 6a, the tooth portion 12b has a tapered shape whose width gradually becomes narrower toward the tip.

That is, the tooth tip is formed in a shape in which both corners of a normal tooth portion having a uniformly sharp point are chamfered at an angle θ. By adopting such a tooth shape, as shown in FIG. 7a and FIG. 7b in the direction of arrow A, the tips of the ratchet teeth 11a and teeth 12b of the latch frame 11 that mesh with each other can be overlapped. Superimposed width L□ (1st b) when width L2 is due to the conventional tooth tip
(see figure), and the teeth 1 of the sensor arm 12
The biting of 2b into the ratchet tooth La becomes smoother. In addition, even though the tooth tips are narrow, the tooth width at the part where the teeth contact each other is as wide as before, so the impact during meshing can be received over a wide surface, preventing damage to both teeth. can be suppressed.

Furthermore, when a strong compressive force is applied to the tooth tip, the tooth tip T deforms (as shown by the two-dot chain line) and can receive the compressive force over a wide area, as shown in FIG.

This also contributes to preventing damage to the teeth. In addition, 16
(See FIG. 2) is a case in which the emergency locking mechanism and acceleration detection mechanism from the retractor shaft 4 to the latch frame 11 described above are accommodated.

Here, several other modified embodiments of the engaging portion between the latch frame 11 and the sensor arm 12 will be described. First, as an example, as shown in FIG. 9, the ratchet teeth 11a of the latch frame 11 instead of the sensor arm are formed into a tapered shape similar to the teeth 12b of the sensor arm 12 described above, and the tooth tip width Tw is narrowed. It is also possible to have a configuration in which

This also provides the same effects of smoothing the meshing and suppressing tooth damage as in the case described above. Further, the tooth portions of both the latch frame 11 and the sensor arm 12 may be formed into a tapered shape, whereby the two effects described above can be obtained synergistically.

In the modified example shown in FIG. 10a and FIG. 10b, which is a view taken in the direction of arrow B, the tip tooth portion 12b of the sensor arm 12 is
is similarly formed into a tapered shape, and the latch frame 1
A collar 17 is formed on one side of the trough 1-1b of the first tooth. The inner surface of the brim 17 is sloped at an angle β toward the bottom 11c. Therefore, even if the distal end tooth portion 12b of the sensor arm 12 is displaced and enters between the ratchet teeth 11a of the latch frame 11, it is guided along the inclined surface of the collar 17 and a predetermined meshing state can be obtained.

This collar 17 also has the effect of reinforcing the ratchet teeth 11a.

Furthermore, the modification shown in FIGS. 11a and 11b is
The tips of the teeth of the sensor arm 12 are formed in an arcuate shape with a constant curvature, and this also allows the above-mentioned favorable effects to be obtained.

The operation of the emergency lock retractor constructed as described above will be explained below. Now, if a vehicle equipped with an emergency lock retractor collides, the weight 13 will swing upon sensing an acceleration of the vehicle body that is greater than a predetermined value. The swinging of the weight 13 causes the sensor arm 12 to rotate upward, and as shown in FIG. 5b, the toothed end portion 12b of the sensor arm 12 smoothly engages with the ratchet teeth 11a of the latch frame 11, allowing the webbing W to be rapidly fed out. The accompanying rotation of the latch frame 11 is prevented. On the other hand, as the occupant tries to continue moving forward due to inertia, the webbing W that restrains the occupant
continues to be withdrawn, thus retractor shaft 4. Latch plate 8. The latch-up spring 9 and the latch ring 10 try to continue rotating together. For this reason, relative rotation occurs between the latch ring 10 and the latch frame 11, and the latch ring 10 responds to the elastic force of the latch-up spring 9 due to the cam effect of the cam surface C provided in the notch 11b of the latch frame 11. It resists and moves inward in the axial direction of the shaft 7. Then, each space 10b of the latch ring 10 passes between each ratchet tooth 88 of the latch plate 8, and its tip engages with each lock tooth 5d of the base 5, so that rotation of the latch ring 10 is prevented. At this time, since each space 10b is also engaged with each ratchet tooth 8a of the latch plate 8, rotation of the retractor shaft 4 is also substantially simultaneously blocked, and the feeding of the webbing W is locked.

When the emergency situation subsides and the pulling force no longer acts on the webbing W, the pressing force against the latch ring 10 due to the cam effect disappears, and the latch ring 10 is activated by the latch-up spring 9.
is pushed back outward by the elastic force of , and the meshing between the space 10b and the lock teeth 5d of the base 5 is released. and,
The shaft 4 is unlocked, and at the same time, the weight 13 returns to its original resting state. When the weight 13 returns, the tip of the sensor arm 12 also returns to its original retracted position, and the engagement with the latch frame 11 is released. This allows the webbing W to be fed out again.

In the above embodiment, the meshing mechanism does not directly lock the webbing W by meshing with the locking mechanism, but instead locks the shaft separately.

The tooth tips of the meshing portion between the acceleration detection mechanism and the lock mechanism are formed into a tapered shape to prevent damage to the meshing portion. However, the present invention is not limited to this, and for an emergency lock retractor configured to directly lock rotation of the shaft at the meshing part between the acceleration detection mechanism and the locking mechanism, the tooth tips of the meshing part may be formed into a tapered shape as described above. A similar effect can be obtained. Furthermore, in the above embodiment, the part that locks the webbing from being fed out and the part that transmits the acceleration detection are relatively rotatably connected, but the emergency lock-retractor engagement part is not rotatably connected between them. may also be formed into a tapered shape.

As described in detail above, according to the present invention, the tooth tips of either or both of the meshing portions between the acceleration detection mechanism and the locking mechanism that locks the winding of the webbing are formed into a tapered shape, so that the meshing operation can be performed. This makes the process smoother, prevents damage to the mutual teeth, and improves the durability of the meshing part and thus the emergency lock retractor.

It should be noted that the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention. The meshing teeth are not limited to resin, and may be made of metal. Further, the present invention can also be applied to a webbing sensing type emergency lock retractor that detects acceleration accompanying sudden webbing payout.

[Brief explanation of the drawing]

Figures 1a and 1b are a side view and a view taken in the direction of the arrow, respectively, showing a conventional meshing part, Figure 2 is an exploded perspective view showing one embodiment of the present invention, and Figures 3 and 4 are An exploded perspective view showing a part of one embodiment of the present invention and a perspective view with different visual acuity, No. 5
Figures a and 5b are explanatory views showing the operation of essential parts of an embodiment of the present invention, and Figures 6a and 6b are plan views showing the sensor arm 12 of an embodiment of the present invention, respectively. 7a and 7b are a side view and a view taken in the direction of arrow A, respectively, showing essential parts of an embodiment of the present invention, and FIG. 8 is an explanation showing a deformed state of the sensor arm 12. 9 are perspective views showing other modified embodiments of the present invention, FIG. 10a and FIG. O
Fig. b is a perspective view and an explanatory view showing still another modified embodiment of the present invention, and Fig. 1'la and Fig. 11b each show another modified embodiment of the sensor arm 12 in one embodiment of the present invention. FIG. (Explanation of symbols) 7: Retractor shaft 8: Latch plate 9: Latch-up spring 10: Latch ring 11: Launch frame 11a: Ratchet tooth 12: Sensor arm 12b = Tip tooth portion Patent applicant: NK Warner Co., Ltd. No. 4 Figure C Figure 50 Figure 5b Figure 6q Figure 6b Figure 7q +21) Figure 7b Figure 8 Figure 9/Do m- +10 Figure 10a +10 Job figure 1 Do'

Claims (1)

[Claims] 1. In a retractor equipped with an emergency lock mechanism that automatically locks the webbing from being fed out in the event of an emergency such as a collision, a shaft around which the webbing is wound and an urging force that urges the shaft in the direction of rotation for winding the webbing. a gear member that is rotatably connected to the shaft and has a toothed portion on its circumference; a detection member that detects an acceleration of the vehicle body of a predetermined value or more and/or a sudden release of the webbing; a pawl member that is driven in response to a detection member and has a tooth portion that can mesh with a tooth portion of the gear member, and each of at least one pair of the gear member and/or the pawl member that meshes with each other; An emergency lock retractor characterized in that the teeth are formed in a tapered shape in which the tooth width decreases toward the tip.