JPS5832995B2 - Diversion device for safety belts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a turning device for a safety belt, in which one end of the safety belt is wound on an automatic retractor and the other end is used for connecting the safety belt to a lock. and in which the safety belt is in contact with a deflection web which is rounded between the automatic retractor and the fitting.

The safety belt of the safety belt automatic device has a large lateral stiffness to prevent twisting of the belt during operation, and a self-winding mechanism on one side to maintain clean contact of the safety belt against the turning fitting and on the other side. When winding the safety belt onto a device and when deflecting the safety belt in the deflection web of a stationary deflection fitting, undesirable tightening effects due to mutual movement of the belt fiber bundles in safety belts with automatic retraction devices are avoided as far as possible. In order to be small, a small longitudinal stiffness is required.

In this case, the fulling effect is caused by the fact that, for example, when a safety belt is tightly wrapped around a diverting web of small diameter, the safety belt is pulled more or less strongly, whereas the outer fiber bundles of the safety belt are then brought under tension. This is a phenomenon in which the inner fiber bundles are compressed in a state where they are just swamped.

This phenomenon causes mutual movements in opposite directions between the outer and inner fiber bundles of the safety belt, which in turn causes friction between the fiber bundles.

Such friction causes premature wear of the fiber bundle or the safety belt.

The friction between the fiber bundles also creates a resistance to the free deflection guide movement of the safety belt along the deflection web, so that the safety belt is not easily wound up and unrolled due to the friction between the fiber bundles.

In addition, in conventional safety belt automatic devices, in order to avoid additional frictional forces during belt feeding, the contact or winding of the safety belt is made particularly close to the safety belt by making the surfaces in the area as smooth as possible. It is required to keep the friction with the stationary deflection web low.

The aforementioned fullness effect is reduced by increasing the radius of curvature of the rounded turning web.

However, experiments revealed the following.

This means that the wrapping of the safety belt can be carried out if there is a particularly smooth surface in the area, i.e. when the friction between the safety belt and the surface of the deflection web is significantly low, the smooth surfaces that are pressed together, i.e. the safety A capstan or belt braking effect is produced between the safety belt and the deflecting web by means of adhesion or adhesion forces which occur between the surfaces of the belt and the deflecting web and which act against the relative movement of these surfaces.

Such a belt damping effect naturally increases the tensile force for the safety belt, especially if the contact section is large in the circumferential direction of the diverting web which is rounded, e.g. due to the large radius of curvature of the diverting web. It acts unfavorably in relation to.

That is, by increasing the radius of turning curvature, it is possible to reduce the filling effect in the safety belt, but it is unavoidable that the belt braking effect becomes relatively large.

The object of the invention is therefore to design a deflection device of the type mentioned at the outset in such a way that the belt braking effect mentioned above is significantly reduced.

In order to solve this problem, according to the invention, the smooth surface of the deflection web is interrupted at several points in the running direction of the safety belt by recesses.

In an embodiment of the invention, the surface has groove-like interruptions extending transversely to the belt direction, and the surface is interrupted at multiple points by dot-like recesses. The contact surface can be reduced by

Furthermore, the contact surface between the safety belt and the deflection web can be reduced by having the surface of the safety belt interrupted in several places, preferably in dotted manner.

In all these embodiments, the aforementioned belt braking effect,
That is, the adhesion effect between the safety belt and the surface of the diverting web may be such that the surfaces of the safety belt and the diverting web are extremely smooth and can slide over each other sufficiently without friction; Based on the fact that the contact surface between the
The adhesion force per unit area in the withdrawal direction is significantly reduced because it is not added along the contact surface between the safety belt and the deflection web.

In this way, the radius of turning curvature of the turning web is chosen as large as possible in relation to the fullness effect in the safety belt without the belt damping effect acting against the withdrawal and retraction of the safety belt under strong loads. Is possible.

In a further embodiment of the invention, the groove-shaped interruption extends at an acute angle to the direction of the belt.

In this case, in relation to the direction of withdrawal of the safety belt, adjacent groove-like interruptions overlap, so that the sliding process is not impeded in any way.

In a further embodiment of the invention, the deflection web has a non-circular, preferably approximately circular, cross section, so that the safety belt is brought into full contact with the deflection web over a predetermined approximately circular width.

Next, embodiments of the present invention will be specifically described using the drawings.

In FIG. 1, reference numeral 1 indicates a deflection web of a deflection fitting mounted on the vehicle body frame, which deflection web is designed as a hollow or solid shaft with a circular cross section.

This diverting web can be wound up and unwound on the one hand in an automatic winding device 3 and on the other hand by means of a safety belt 2 which is locked with a locking fitting in a possibly immovable lock (not shown). The surface of contact between the inner surface of the textile safety belt 2 and the surface of the stationary deflection web 1 is partially wrapped around the folding angle α, the width of the safety belt 20 as well as the diameter of the deflection web 1. determined by.

The experiment revealed the following.

In other words, when the surfaces are smooth and in contact with each other over a large area, a belt braking effect or adhesion effect is produced, and the belt braking effect or adhesion effect increases as the contact surface becomes thicker. In particular, the longer the contact distance in relation to the pull-out direction S□ or the pull-back direction S2, the greater the belt braking effect. In order to reduce the friction between the safety belt 2 and the deflection web 1 by selecting a larger diameter of the webs, this is increased by making these surfaces, in particular the deflection web surfaces, extremely smooth, for example by grinding them.

Furthermore, experiments have shown that by reducing the contact surface between the safety belt 2 and the deflection web 1 in the contact area, the belt friction effect can be reduced (or even significantly eliminated).

The reduction of the contact surface is achieved by the deflection web 1 of the integral deflection fitting, which can be attached to the vehicle body frame via the hole 5, transversely to the belt withdrawal or winding direction, as shown in FIG. This is achieved by providing interruptions 6 by means of elongated groove-like recesses, which extend at an acute angle to the belt withdrawal or withdrawal direction and overlap one another in this direction.

The reduction of the contact surface can further be achieved by providing the metallic deflection web 1 with dot-like recesses 7, preferably machined by shot blasting, according to FIG. This can be done by interrupting the resin coating with a caustic agent.

The belt of adhesion between the surfaces of the safety belt 2 and the deflecting web 1, which in each case are pressed together with great pressure by interrupting the surfaces, especially when using automatic retraction devices that act in dangerous situations In the direction of wrapping from corner to corner, it is possible to avoid the increase of wrapping from corner to corner.

Therefore, no belt braking action occurs, even though the frictional forces are kept very low, for example because the remaining surfaces are polished.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the safety belt deflection device, FIG. 2 is a perspective view showing an embodiment of the deflection fitting according to the invention, and FIG.
The figure is a perspective view showing another embodiment of the turning fitting according to the invention. 1: Turning web, 2: Safety belt, 3: Automatic winding device, 4: Turning metal fitting, 5: Hole, 6・－・・・Interruption point, 7・
・---Concavity, a---...Covering is at the corner, Sl ・
---Pull-out direction, S2...-Pull-back direction.

Claims (1)

[Scope of Claims] 1. A turning device for a safety belt, wherein one end of the safety belt is wound up by an automatic winding device, and the other end has a metal fitting for connecting the safety belt to a lock. and the safety belt is in contact with the rounded diverting web between the automatic winder and the fitting, in which case the smooth surface of the diverting web 1 is safe. A turning device for a safety belt, characterized in that the belt 20 is interrupted by recesses at a plurality of locations in the running direction. 2. Claim 1, in which the surface of the turning web 1 is interrupted at multiple points in the range where it contacts the safety belt.
Turning device as described in section. 3. Turning device according to claim 1, wherein the surface has groove-shaped interruptions 6 extending transversely to the belt direction. 4. Turning device according to claim 3, in which the groove-shaped interruptions 6 extend at an acute angle to the direction of the belt. 5. The turning device according to claim 1, wherein the surface is interrupted at a plurality of points by dotted recesses 7. 6. A turning device according to claim 1, wherein the turning web has a non-circular cross section. 7. The turning device according to claim 1, wherein the surface of the safety belt is interrupted at a plurality of locations.