JPS5820284Y2 - Seat belt extension prevention device - Google Patents

Description

[Detailed description of the invention] The present invention is an improvement of the clamping surface of the belt extension prevention device, that is, the clamping device, which clamps the belt pulled out from the emergency lock type winding device in an emergency and prevents the belt from extending later. It is related to.

In a safety belt retractor for safely holding an occupant of an automobile, etc., it is preferable that the pulled out restraint belt has an appropriate tension under normal belt usage conditions.
This eliminates the feeling of restraint caused by the use of belts for the occupants, but on the other hand, the safety belt in the take-up device is locked in the event of an emergency lock due to the residual pulling force from the spring and the extension of the webbing itself. Even so, a phenomenon of extension due to inertia force was still observed, resulting in an inability to sufficiently secure the occupant retention function.

For this reason, conventionally, in passive belts, etc., an independent clamping device is placed in the route of the belt pulled out from the winding device to prevent the belt from stretching out. Various improvements have been proposed in Japanese Patent Application Laid-Open No. 51-7613 and the like.

However, in the systems described in these publications, the belt pulled out from the winding drum is guided directly to the clamping device, so as the belt winding diameter decreases, the belt comes into contact with the fixed teeth, making the belt heavier when pulled out, and the movable lever Since the center of the rotation axis is located approximately in the center, the length of the movable teeth is limited, the contact area becomes small, and there are problems in that a sufficient extension effect cannot be obtained.

Therefore, the inventor of the present invention conducted studies to overcome the above-mentioned difficulties, and effectively selected the length of the movable teeth regardless of changes in the belt winding diameter to effectively prevent belt movement due to belt extension. We have previously proposed a new winding device that does this.

As shown in FIG. 1, this winding device is a device in which a corresponding clamp portion is integrally assembled adjacent to the upper side of the emergency lock type winding device, and the frame of the winding device is located in the belt pull-out path. Pedestal 9 fixed to the fixed part of 1
The movable member 11 is configured to include a receiving member 10 having a wavy uneven clamping surface that comes into contact with the receiving member 10, and a movable member 11 that is paired with the receiving member 10 and has a corresponding wavy uneven clamping surface.
A fulcrum roll 7 is pivotally supported at the entrance side of the clamping part, which bends the path of the belt 3 pulled out from the reel of the winding shaft 2 and allows the belt to pass through the clamping part between the two members. The belt 3 can be rotated around the center by interlocking and holding the belt 3 in cooperation with the receiving member 10, and between a restraining position where the belt 3 is bent and absorbed by bending, and a non-stopping position where the meshing and holding is released. Moreover, all the time,
A biasing spring 13 that tensions and holds the receiving member and the movable member in the non-restricted position. In addition to being equipped with a tension spring 12, a guide roller 8 is pivotally supported on the outlet side of the clamping part to restrict bending of the belt path and rotate the movable member to the stopping side when a tensile impact force of a predetermined value or more is applied to the belt. When the belt is under abnormal tension due to a collision etc., the pawl 5 receives the displacement of the sensor 6.
Ratchet wheel 4 coaxial with winding shaft 2
is engaged, and the belt drawer is urgently locked, and the movable member 11 is moved by the movement of the guide roller 8 against the tension spring 12.
It has a structure in which the belt is moved and brought into contact with the pedestal 9 side together with the receiving member 10 to prevent the belt from extending further.

However, when testing the clamping force of such a take-up device, we subsequently repeated various tests with each of the above-mentioned known clamp mechanisms, and found that in all cases, depending on the special deceleration caused by a high-speed collision, even with each of these clamp devices. It has been found that the belt slips, fuzzing occurs, and in severe cases, the belt breaks, which is still a problem in terms of safety measures.

In order to further solve this problem, the inventor of the present invention attempted various experiments including investigating the cause of the problem. As a result, the inventors of the present invention found that the weft yarns were drawn due to the size of the aperture during weaving of the belt web, and that the width of the web was equalized. Because the warp tension and the number of warp threads in the selvage part are increased, the warp thread density in the iron part is locally high, and this appears as uneven belt thickness and decreases in retention elongation rate. It was discovered that a major cause of this was the disparity in the properties of the belt web.

That is, a belt having potential non-uniformity as described above is formed under tension from both sides by a member A having a pair of wavy uneven surfaces;
When clamped with B, as shown in Figure 2, the first bell) C
The thicker portions of both ear portions C1 and C2 are pressed, and then the entire surface is uniformly clamped by the corrugated uneven surface, and therefore both ear portions C1 and C2 are in an over-pressed state, resulting in the above-mentioned condition. Coupled with the phenomenon of a small elongation rate, the belt edges break prematurely, resulting in a decrease in tensile strength efficiency.

Furthermore, due to the structure of the wave-shaped uneven member under tension load, both the upper and lower members A and B that are in contact with the center line of the belt C deform in the direction of escape, as shown in Fig. 3, and the belt C is further deformed. Excessive pressure is applied to both ear portions C1 and C2, which eventually generates heat while producing fuzz from the ear portions, leading to belt breakage.

In view of the above-mentioned conventional technical trends, the present invention is designed to absorb and compensate for the latent properties existing in the belt web and the shape of the clamping surface of the clamp device, which adjusts the deformation of the clamp in advance, for safety reasons. is its main purpose.

Hereinafter, features of the present invention will be explained with reference to each aspect shown in the accompanying drawings.

4 to 7 show a pair of upper and lower holding members A corresponding to the receiving member and movable member in FIG. 1.

Fig. 4 shows various aspects of the arrangement in the cross section of B, first, in Fig. 4, the upper clamping member A is formed of a clamping member with normal wave-shaped uneven teeth, and the lower clamping member B has wave-shaped uneven teeth on its clamping surface. However, in this case, the tooth tip side forms an arc shape at both ends in the belt width direction to widen the gap with the tooth bottom of the opposing upper holding member A.

Therefore, in this case, the gap between the tooth tip of the lower clamping member B and the tooth bottom of the upper clamping member A at the center, or the gap between the tooth tip of the upper clamping member A and the tooth bottom of the lower clamping member B, is set to 11,
If the gap between the tooth tip of the upper clamping member A and the tooth bottom of the lower clamping member B at the end is 72, and the gap between the tooth tip of the lower clamping member B and the tooth bottom of the upper clamping member A is 13, then 11=12 13, and the belt clamping gap at least at the center portion is smaller than the belt clamping gap at both ends.

Of course, some parts of the clamping gap at both ends are the same as the central clamping gap, but excessive pressure on the ears in this area is absorbed by the adjacent large gap, resulting in a large gap. Become something.

Therefore, the pressing force applied to both ears of the belt will not be excessive than the pressing force applied to the central part, and both the belt ears and the central part will
It becomes possible to perform the extension prevention effect with a substantially average pressing force.

FIG. 5 shows another embodiment of the clamping member of the present invention, in which the upper clamping member A is a clamping member having a wavy uneven clamping surface similar to the one already proposed, but the lower clamping member B has a central part in the cross section in the belt width direction. It forms a curved arc-shaped surface with a bulging shape.

In this illustrated example, the tooth bottom is also formed into a similar arcuate curved surface in accordance with the tooth tip, so the relationships 11, 12, and 13 are 11<12, 11<13.

In other words, the belt clamping gap at the central portion is smaller than the clamping gap at both ends of the belt, compensating for the approximately average pressing force across the belt metal peaks, and eliminating concerns about edge breakage.

Next, FIG. 6 shows still another modification of the clamping member of the present invention,
The bottoms of both the upper and lower clamping members are parallel, but both ends at the tips of the teeth are sloped to widen the clamping gap.

In this case as well, the pinching gap at the ends of both ears at the center is set to 1.
If the relationship is expressed as 1,12°13, then 11<12-13, and it is clear that the belt clamping gap at the center is smaller than the belt clamping gap at both ends.

Furthermore, FIG. 7 shows another modification according to the present invention,
The upper clamping member A is a clamping member equipped with wave-shaped uneven teeth similar to those shown in Figs. It is formed in the shape of a slope that slopes downward.

In this case as well, the clamping gap is made smaller at the center of the bell (C) than at the ends of both ears.

Therefore, the equalization of the pressing force over the belt gold plate is compensated.

In addition to the examples shown above, it is possible to form a plurality of small parts with small clamping gaps in the middle part in the width direction of the belt, or to make the tooth tips not hold parallel to each other in the upper and lower clamping members as in a normal clamping member. It is also possible to process only the bottom and widen both ends to make the clamping gap larger than the center.
This also makes it possible to achieve the desired purpose.

That is, in any of the above cases, the belt pressing force at the center portion is approximately averaged with the belt pressing force at both ear ends, and excessive pressing force is prevented from being applied to the ear ends as in the conventional case.

Of course, in each of the above cases, the depth of engagement between the opposing grooves and grooves on the sandwiching surfaces varies somewhat depending on the number of engagements between the grooves and grooves, but it is usually desirable to be about 2 to 8 times the belt thickness. Is the gap the same as the belt thickness?
It is preferable to select at most twice the amount.

When using a clamping device having an inclined upper clamping surface of the present invention, in the event of a collision, etc., the take-up reel is locked by a known emergency locking mechanism, and a sudden tensile force is applied to the belt due to the inertia of the occupant. When the movable member rotates around the fulcrum roll, it is of course necessary to immediately engage and clamp the belt between its uneven clamping surfaces and reliably restrain the belt from extending further. This results in restraint being achieved with a substantially uniform pressing force over the entire width direction, or at least without applying an excessive pressing force to the ends of both ears.

Thus, according to the extension prevention device of the present invention as described above, when an abnormal tensile force is applied to the belt being pulled out from the take-up reel along its path, the belt is immediately engaged and clamped to automatically prevent unnecessary extension of the belt. Not only can this be prevented, but also the thick parts of both edges of the belt web will not be excessively pressed when clamped by the uneven clamping surface. It is possible to prevent the occurrence of fuzz and to prevent the belt from being cut at the edges.

Therefore, even if there is latent non-uniformity in the belt web, a sufficient pressing force is applied to accommodate the potential non-uniformity, and an excellent effect is achieved in that the clamping effect by both the upper and lower clamping members is good and reliable.

[Brief explanation of drawings]

FIG. 1 is a schematic view showing an example of a winding device equipped with a clamping device such as the extending device of the present invention, FIGS. 2 and 3 are sectional views in the belt width direction showing defects in the conventional clamping member, 4 to 7 are explanatory cross-sectional views in the belt width direction showing various aspects of the upper and lower holding members according to the present invention. A... Upper clamping member, B... Lower clamping member, C... Belt, C1, C2...
Belt ear end.

Claims (1)

[Scope of utility model registration request] 1. It consists of a pair of clamping members with corrugated teeth that engage with each other on opposing clamping surfaces, and at least one of the clamping members is a movable member, and normally the emergency lock type winding device is passed through between the clamping surfaces. In a device that allows the pulled out belt to pass freely, but in an emergency, activates the movable side member to clamp the pulled out belt therebetween and prevent it from extending further, A seat belt extension prevention device characterized in that the gap between the clamping surfaces is made smaller at the intermediate portion in the belt width direction than at both end portions. 2. The seat belt according to claim 1, wherein at least one of the opposing clamping surfaces of the pair of clamping members has an arcuate shape with the intermediate portion approaching the other clamping surface in cross section in the belt width direction. Extension prevention device. 3. The seat belt according to claim 1, wherein at least one of the opposing clamping surfaces of the pair of clamping members has a slope shape that approaches the other clamping surface at the intermediate portion in a cross section in the belt width direction. Extension prevention device. 4. The meshing depth of the wavy uneven teeth of the pair of clamping members that mesh with each other is 2 to 8 times the thickness of the belt portion passing through the gap in the center part in the belt width direction, and the tooth tips and teeth facing each other when meshing are The seat belt extension prevention device according to claim 1, wherein the clamping gap between the bottoms is equal to or twice the thickness of the belt portion. 5. Utility model registration in which the gap between the opposing tooth tips and tooth bottoms of a pair of clamping members is equal to or twice the thickness of the belt edge at both ends in the belt width direction, and at least less than that at the center. A seat belt extension prevention device according to claim 1.