DE2645456A1 - Seat-belt inertia sensor - has one inertia mass hung on gimbals working together with second loosely fitted mass - Google Patents

Abstract

Inertia-sensitive seat belt blocking mechanism, where the inertia mass does not block the ratchet mechanism, when the vehicle is travelling or standing on a sloping surface, but no deceleration takes place. The mechanism has a pendulum (9) suspended in a ring-shaped frame (10). The pendulum is suspended by pin (11) and the frame, fitted with two pins (13) in lateral direction is seated in frame (12). Pendulum (9) has a ring-shaped groove on top in which the bottom edge of a bush-shaped second inertia mass (15) are resting loosely. Pin (11) penetrates the bushing (15) a hole (20) which is larger than the dia. of the pin. If the vehicle is on a sloping surface, or a swinging movement of the pendulum due to an uneven surface takes place, the bushing is dislocated only slightly and catch (17) remains out of engagement with ratchet wheel (15). Only a deviation of the pendulum caused by impact or sudden deceleration dislocates or trips the bushing sufficiently to engage the catch with the ratchet wheel.

Description

Inertia-dependent sensor

The invention relates to an inertia-dependent sensor with a first inertial body with a pivotable one, which is mounted in a housing-fixed bracket stored release arm for the release and / or blocking of safety organs, z. B.

Locking pawl in a belt retractor, opening an air cushion, extending it a headrest.

The present invention is used in conjunction with an automatic Belt retractor described in vehicles for securely holding occupants is used by means of a belt strap. However, this is only about a single field of application, it being expressly noted that the invention is not limited to this.

There are different Gurtbandaufwickelvorrchtungen, also as so-called Retractors or automatons can be called, known with interlocks, in which an inertia mass designed as a pawl, pendulum or ball is used will.

From the US patent r. 3 237 729 is an inertia dependent Sensor for triggering a solenoid-controlled piston and activating a pawl known in which, according to the type described above, a ball as Inertia body when moving from its rest position raises a trigger arm, whereby a circuit can be closed.

It is also possible to control the safety catch by pneumatic control to bring the piston into engagement with the ratchet wheel of a belt take-up roller, wherein a valve of the pneumatic system through said trigger arm at the moment of the accident in one or the other direction of flow of the flow controlled by means of opens, when In the accident, the vehicle experiences an acceleration, ie a shifting of the Ball of inertia out of the rest position and the lifting of the trigger arm to Actuation of the Rn, eumatic valve ensures.

It is also in connection with a locking device for Vehicle seat belts from the German patent application P 21 28 741.2 an inertia-dependent Known sensor in which a pendulum is the first inertial body in the rest position is arranged vertically and at its upper end a trough-like one Raising surface for the piston of a pawl. At the moment of the accident, i. H. if the vehicle has exceeded a certain acceleration threshold, it overturns standing pendulum and presses the Snerr pawl over the trough-like support surface with the ratchet wheel of a belt take-up roller in engagement.

Finally, US Pat. No. 3,338,831 is one of the last described Embodiment very similar sensor device known, in which the idle state (when the belt retractor is not locked) pendulum arranged vertically is mounted in a ring fixed to the housing. Here too, if one is exceeded given acceleration value at the moment of the accident, the pendulum swung out of the perpendicular, which thereby the with a down on the trough-shaped support surface of the pendulum protruding nose of the pawl lifts, whereby the pawl with the Ratchet wheel of the belt retractor engages.

These and all others currently available on the market and in the Inertia-dependent sensors currently under development offer the user of the belt strap system although the comfort that it is in a normal position even when buckled up of the vehicle on a horizontal road as well as while driving on a level road surface easily by extending and pulling out the belt strap can move forward and to the side of the winding roll while in the moment of an accident one Blocking of the ratchet wheel and thus the take-up roller takes place, so that through a retractor spring is not applied to the belted occupant's torso can be pulled out further and the occupant is held securely in the seat by the belt will.

This locking of the belt retractor usually takes place at 0.3 g, which represents the acceleration threshold at which the ball hits rolls up the conical part of the bowl surface or the pendulum tilts. In all of these Cases, the kinetic energy of this inertial body, i. H. the ball or the pendulum, used to lock the trigger arm or rocker arm into locking engagement with to bring the ratchet wheel.

In a disadvantageous way, however, care must always be taken in a very accurate manner be taken to ensure that the security device provided with the sensor is accurate that position is installed that achieves the effects described above will. The housing with the belt retractor and therefore also with the sensor must be in the vehicle be adjusted accordingly. If this were not the case, there would be none unlocked or rest position of the inertial body, the take-up roller of the automatic seat belt would always be stuck and the user would not be able to put on the belt at all.

In another disadvantageous way, the inertia grains succumb the known belt retractors both vehicle acceleration and gravity, d. H. the inertia body can partially accelerate the vehicle and gravity do not distinguish. In the case of a car parked on a steeply sloping street, it would be The sensor is in the out-of-rest position even when the belt retractor is correctly adjusted, so that the occupant does not pull the webbing out of the retractor and become with it don't buckle him up - n can.

Another disadvantage of the known inertia-dependent sensors is that that they are very sensitive and represent, so to speak, a nervous system, which on the one hand, the quick blocking required for security reasons guaranteed, but on the other hand undesirable with certain oscillating movements of the vehicle often appeals. The vehicle drives z. B. on a very bumpy road, so arrives the automatic belt retractor with each deflection of the pendulum as a result of a movement Pothole or a road hollow immediately in vibrations and when these vibrations If you stop in the vehicle, the belt retractor remains continuously in the locked position and is therefore practically no more than a machine with the estimated value described above To denote comfort. Attempts have already been made to disadvantage this by friction To dampen oscillations in the sensor system /, but ultimately did not have any success, without that the measures brought disadvantages at the expense of security, there the friction also affects the accuracy.

It should also be noted that in current models of automobiles the fastening points for the belt retractor, e.g. B. on the spar of the vehicle, not only usually have no horizontal or exactly vertical mounting surface but even from wagon type to wagon type an.ders are designed. Release or safety systems with an inertia-dependent sensor of the known type bring for the creator Inertia-dependent sensors require that many different Components must be kept in stock, the greatest part in their design differ only so little from one another that they can be seen with the naked eye can not separate from each other. This results in sources of error during assembly or a lot of work.

The object of the invention is therefore to improve the inertia-dependent Sensor of the type mentioned at the beginning, in order to construct it in such a way that it is self-aligning, that the sensor is in a wide range regardless of the inclination of the housing Inertia body is always in the rest position (out of locking engagement) and only when exceeded certain accelerations the desired triggering or blocking takes place.

According to the invention, this object is achieved in that the first inertial body is gimbaled, a second inertial body with at most the same size Mass moment of inertia like the first body of inertia movable on the latter stored and the trigger arm is arranged close to the second inertia body has curved surface. An inertia-dependent built with these features of the invention Sensor can be used as a uniform component for every vehicle regardless of the Inclination of the mounting surface can be made in the vehicle.

Mix-ups of individual components before or during assembly are included switched off. The production becomes more economical and guarantees a lower one Error rate. Due to the cardanic suspension, the first inertial body is located this is always plumb, so that the rest position, even when the car is parked at an angle, d. H. Out of locking engagement, the inertial body guaranteed and the possibility of buckling up of the belt strap are ensured. Nan can use the new inertia-dependent sensor even carve into the adjustable vehicle backrests, so that even when changing the angle of incidence of the backrest before or during the journey without further adjustments the rest position of the first inertial body is always guaranteed. It can be installed when installed of the new sensor according to the invention no longer happen that when already shipped Vehicles on the way of the ReklarnatLon by changing the setting of the position Defects in the bracket fixed to the housing must be eliminated.

The sensor according to the invention can surprisingly between Differentiate between gravity and vehicle acceleration.

The second, which is movably mounted on or on the first inertial body Inertia body with at most the same mass moment of inertia as the first Inertia brings other unexpected benefits. This is how it gets with normal driving the sensor is no longer in the release or locked position in very hilly terrain. The reason for this is that the system always automatically moves into the perpendicular adjusts. The second inertial body displaces the device according to the invention in the state of increased readiness, in which the requirements for a quick lock are created. In the event of weak impacts against the sensor according to the invention, namely, it tilts only the second body of inertia out of balance to be in weak contact with the curved surface attached to the trip arm. He follows then the dangerous stronger shock, d. H. the greater acceleration, so occurs by tilting the first inertial body out of the perpendicular, the trigger arm is immediately raised with the following tripping or

Blocking of the security organs. Because only the moment of inertia of the first inertial body is sufficient to remove the trigger arm from an external Pivoting rest position out.

smooth The other, very pleasant advantage is the / interference attenuation as a result of the opposing movement of the two inertial bodies when driving on wavy So streets remains the safety organ beyond intervention, and comfort is significantly improved for the 3user.

The second inertia body is an advantageous embodiment of the invention a sleeve. This 13Rt is known to be particularly easy to manufacture and guarantee all the advantages of mass production. In a further advantageous embodiment of the According to the invention, the second inertia body can also be a sphere. With another expedient embodiment, the second inertia body consists of several tilting segments, so that the most varied of setting options for the values of the moments of inertia of the first and second inertial bodies are possible with respect to one another. The invention is further characterized in that the bracket fixed to the housing has an outer frame has, which has two diametrically arranged recesses for receiving pins, Waves or the like is provided. The outer frame can e.g. B. made of plastic be made and half-open, arranged in alignment, diametrically opposite have bores open on one side, in which the pin of the other cardanic Element only need to be plugged in, inserted or clamped. Through this manufacturing advantages result from simpler assembly.

According to the invention, it is advantageous if the cardanic Suspension has an inner frame on which cardanic pins and / or pins are attached.

The inner frame can also be made of plastic, as a result of which assembly is further simplified and subject to thorough automation can be.

According to the invention, the inner frame is expediently movable stored in the outer frame, which means that it works perfectly with the simplest means cardanic suspension is guaranteed. The invention is particularly useful furthermore designed in that the frame is a ring, preferably a partial ring is; a partial ring is advantageous in this respect, il without sacrificing storage advantages space snarling? can be provided for dimensions.

It goes without saying that the ring can also be an oval, ellipse or the like is to be understood.

In other embodiments it can be expedient if according to the invention the frame is out of round, preferably rectangular. Quadrilaterals can also be found under these Embodiment fall.

Often there is the need for freedom to move the inertial body less in motor vehicles in the direction transverse to the direction of travel. Then suffices as Kafdan movement construction, when one side of the frame is more than that other is designed. Also the first inertial body, which in certain embodiments in an advantageous manner a pendulum can be out of round be trained.

Only the second inertial body must have a round outer Areas must be provided so that the sensitivity of the inertia-dependent sensor according to the invention always retained in all directions.

tlio already indicated above, it can be particularly advantageous according to the invention be when the first inertial body is in the rest position in the perpendicular, preferably is a hanging pendulum that has a tunnel open at the bottom or side recesses having. This tunnel makes assembly easier to the extent that it is then the pendulum only needs to be hung on the inwardly protruding pins. The same advantage can be achieved if instead of using the whole pendulum body in its lower half, open tunnel running through below only on the side diametrically opposite each provides a recess, because it is possible if these pins of the inner frame a little way into the first inertial body, i.e.

protrude into the pendulum to support it.

The invention is expediently further developed in that in the Sleeve two recesses arranged in alignment are provided. It is possible when using a sleeve as the second inertial body on the recesses of the just to waive the type described, if you z. B. the tunnel or used the side recesses in the lower part of the pendulum, you can do that Suspend the pendulum further in its upper part so that there is room for it to protrude through the pivot pins in the bypassing the upper part of the pendulum at the height of the pins Necks must be provided. This space is created by the recesses mentioned. For example, you can have two diametrically opposite holes of larger diameter than provide the outside diameter of the pins. This embodiment results Then there is also the advantage that the sleeve, which is on top of an approximately horizontal provided ring surface rests, not be tilted arbitrarily far out of the perpendicular can.

It is also particularly expedient according to the invention if one of the Centrally arranged cupped pin protruding from the top of the pendulum which is encompassed by the second inertial body. Here, too, he is used as a sleeve formed second inertia body by the centric pin against too large Retained from tipping out of the perpendicular.

The cupped pin is preferably inserted into the pendulum by a snug fit, or it can also be screwed in, with one at the upper free end of the pin plate-like disc is provided, which is in the rest position within the sleeve is located; wherein the design of the sleeve is chosen so that the cupped pin in the rest position in one arranged certain distance from the sleeve will. In all embodiments, it is always ensured that at maximum Swing out of the second inertial body in the last described embodiment the sleeve, one edge of which is in weak contact with the curved surface, which forms the underside of the trigger arm. The curvature of this surface on the release arm can be written with a dome or with a dome over the pendulum in the sleeve earth. In some embodiments in which the degree of freedom of movement of the sensor is mainly provided in one plane, the curvature can be a have circular part lying in one plane, in other embodiments with greater movement possibilities and more degrees of freedom of the sensor can be further Curvatures from the marriage just described are provided in different directions be, in the optimal case of most degrees of freedom, the curved surface is one Dome or part of a sphere.

Other advantages, features and uses of the present Invention emerge from the following description in conjunction with the drawings. 1 shows a schematic side view of a known belt retractor Ratchet wheel, pawl and hanging pendulum, Fig. 2 is a plan view on the belt retractor according to FIG. 1, FIG. 3 the inertia-dependent according to the invention Sensor in a first embodiment with a hanging pendulum as the first inertial body, Sleeve as a second inertia body and pawl with a dome-shaped curved one Surface, in the rest position, Fig. 4 the embodiment of Figure 3 after a weak Shock, Fig. 5 the same embodiment as Figures 3 and 4 according to additional stronger impact and deflection of the pendulum, FIG. 6 shows a plan view the illustration according to Figure 3 omitting the locking lever and the curved Area, FIG. 7 a representation similar to FIG. 3, but of a different embodiment, in which the second inertia body is formed by several tilting segments, Fig. 8 is a plan view of the embodiment according to FIG. 7, Figure 3A the individual view of a tilting segment with a sectional view arranged next to it in the direction of arrows A-A.

9 shows an embodiment similar to FIG. 3, with only the recess in the sleeve and its displacement with respect to the bearing pins 11 in two positions is shown, namely with solid lines in the rest position and with dot-dash lines in the tipped position of the loose, Fig. 10 in Similar representation to Figures 3 and 7, a further different embodiment, in which the second inertial body is a sphere, FIG. 11A shows a special embodiment an outer frame part made of plastic in plan view and side view, 11B shows such a representation of the inner frame, and FIG. 11C shows a sectional view on the left by a special embodiment of a pendulum with a tunnel that is open at the bottom; in the middle a sectional view according to the arrows B-B in the left illustration; and on the right the cross-sectional view of the pendulum with lateral recesses, Fig. 12 the plan view of another embodiment of a sensor according to the invention as shown in Figures 6 and 8, but the frames are rectangular Fig. 13 shows another embodiment of the pendulum with the cupped pin and FIG. 14, as an application example, a sensor similar to that in FIGS. 3-5, wherein the trigger arm is only designed as an electrical contact arm.

In a housing 1, a belt strap 2 is wound onto a winding roll 3, which is provided with a winding spring 4. This is on the side of the case 1 attached. On the side of the winding roll 3 opposite the spring 4 a ratchet wheel 5 attached, which in the event of a sudden acceleration of the Vehicle with a Auslosearm or Sperrhehel 6 can engage. This The locking lever is actuated by a pendulum 7 which is suspended from a carrier 8 is. The pendulum with its holder or the carrier is called the trägbeitsabbängige Sensor viewed.

According to FIG. 3, there is a pendulum 9, which is the first inertial body represents, in an inner frame designed as a ring 10 by means of two diametrically arranged pins 11 is suspended, the inner ring 10 via two short pins 13th movably arranged in an outer frame 12 which is also designed as a partial ring ist.weil the pins 11 and pins 13 are usually aligned approximately perpendicular to each other which results in the Cardapic suspension, the pendulum 9 align even in a wide realm.

On a horizontal annular surface 14 of the pendulum 9 sits astride a cylinder, pipe section or the sleeve 15, whose mass moment of inertia is lower, but is at most equal to de of pendulum 9.

The carrier or outer ring 12 has a pivot bracket 16 in which a release arm 17 designed as a locking lever is suspended. Two attacks are provided on the pivot bracket 16, which the pivoting movement of the locking lever 17 limit both downwards in one direction and upwards in the other direction. The trigger arm or pivot lever 17 is approximately spherical or dome-shaped curved surface 18 provided, the center of which in the central axis of the pendulum 9 or is in the middle of the inner ring 10. This leaves the distance between the upper end of the sleeve 15 and the curved surface 18 as long as constant as none sudden acceleration acts on the sensor.

But if now a weak shock, e.g. B. by a run over strength Bump occurs and a weak acceleration acts on the sensor According to the representation in FIG. 4, the lens 15 is faster and further from the dot-dashed line drawn plumb tipped out as the pendulum 9, because the sleeve as the second Inertia has a smaller moment of inertia than the pendulum, the first Inertial body. In Figure 4 it can be seen that the angle β is greater than the angle c <. The upper end of the sleeve 15 is now in weak contact with the Kalottenflöche 18. At this moment, the sensor according to the invention is on maximum readiness set, but the locking lever 17 is not yet engaged because the kinetic energy of the sleeve with the lower mass moment of inertia is not sufficient to bring it into engagement with the ratchet wheel 5.

According to Figure 5, however, z. B. after a stronger shock, as with one Accident, the pendulum 9 is also deflected, whereby the angles 0 (2 or ß 2 result, the kinetic energy of the one with the greater mass moment of inertia Pendulum 9 is sufficient to silver the positive contact of the sleeve 15 with the spherical cap 18 to bring the locking lever 17 into engagement with the ratchet wheel 5.

To illustrate the embodiment shown in the figures according to Figures 3-5 a plan view is shown, from which it follows that the pins 13 are fastened in the outer ring, fixed to the housing, so that the inner ring 10 suspended therein is in alignment around the axis through the Pin 13 can rotate.

In a perpendicular direction to this, the pendulum 9 can move over the pins 11 move in relation to the inner ring 10, whereby the cardanic suspension is given. The attached lens 15 can also be seen, which preferably has a recess 2n is provided, as indicated by dashed lines around the pins 11 in FIGS. 3-5 and is shown even more clearly in FIG.

According to Figure 9 you can see the ring surface 14 on the pendulum 9, on which the sleeve 15 is loosely placed in such a way that the pin 11 through the opposite arranged recesses 20 protrude. If only the sleeve 15 as a result tipped out of a smaller pile, as shown e.g. in Figure 4, the recess 20 ensures a limitation of the tilting movement, because in the illustration In FIG. 9, the pins 11 come into contact with the delimitation of the recess 20.

In Figure 7 is another embodiment in a schematic vertical section and in Figure 8 shown in plan view, in which on the pendulum 9 above a cup-like Recess 23 is formed. In this cup-like annular space there are several tilting segments 21 arranged, which are only loosely inserted and through a plate stopper 22 are prevented from falling out and tipping out too much. Even with this one Embodiment is again the difference between the moment of inertia the first inertial body, d. H. the pendulum 9, and the second inertial body, d. H. the majority of the chin segments 21, large enough so that according to the dash-dotted line Representation in Figure 7 z. B. the left tilting segment in the direction of the shown = n Arrow can tip out before the pendulum 9 moves, which is unique can raise enough kinetic energy when pivoting out of the plumb bob to to bring the locking lever 17 into engagement with the ratchet wheel.

In FIG. 8 it can be seen that in this embodiment there are four tilting segments 21 are provided, the top view or

Cross-section clearly emerges again from FIG. 8A. One recognises here also spacer sleeves 30, which are placed over the protruding pins 11 are, which in turn for the cardanic suspension of the pendulum 9 in the outer, Partial ring 12 fixed to the housing are provided.

A very similar embodiment is shown in FIG. 11, in which just as in FIGS. 11-14, the same parts are provided with the same reference numerals are. In this embodiment according to FIG. 10, the pendulum 9 has a trough-shaped top Surface in which as a second inertial body a ball 19 is arranged. This works in the same way as the sleeve 15 or the tilting segments 21, in which, with a slight outward push, it comes into weak contact with the arrives curved escape 18 and brings the sensor in the standby position.

The outer partial ring made of plastic can be seen from FIG. 11A 12 with two diametrically arranged recesses 31 for receiving the pin 13. In FIG. 113 shows how the inner ring 10 'made of plastic is made in one piece the pins 13 ′ on the outside and the two protruding inwards approximately perpendicular to this Bears pins 11 '.

In FIG. 11C, the pendulum q with the tunnel 36 open at the bottom is in two mutually perpendicular sections according to the two left parts shown, while on the right in FIG. 11c the pendulum 9 is provided with lateral recesses 36 '. The pins 11 protrude into a recess 36 'on each side, which in turn the cardanic suspension of the pendulum 9 is guaranteed.

According to Figure 12, the outer frame 12 as a U-shaped, in plan view rectangular holder and the inner frame 10 shown as a rectangle, which is rotatably mounted in the outer frame 12 via the pin 13. The sleeve 15 sits again on the flat annular surface 14 on the pendulum 9. The latter is also designed rectangular, but the sleeve has round outer surfaces, so that the sensitivity of the sensor according to the invention is given in all directions.

From the special further embodiment according to FIG. 13 it can be seen how the pins 13 protrude into the lateral recesses 36 'of the pendulum 9. These is provided with a centrally arranged cupped pin 37, the z. B. after putting on the sleeve 15 is connected to the pendulum 9 and the kinpening of the sleeve 15 is limited and the setting is also made easier in that it makes the pendulum with a sleeve can be handled better as a unit in the assembly.

Finally, FIG. 14 shows the design of the release arm 17 as electrical contact that raises itself as a result of the pendulum's deflection two contact pins 34 bridged, so that the circuit with the power source 33 and the ignition cartridge 35 is closed and z. B. a pyr-otechnical ignition for the Inflation of an airbag can be done.

Claims (12)

P a t e n t a n s r r: 1 ch e 1. Load-dependent sensor with a first inertial body with a pivotable, mounted in a holder fixed to the housing mounted trigger arm for triggering and / or blocking of safety processes, z. ß. Locking pawl in a belt retractor, opening an air cushion, extending one Headrest, characterized in that the first inertial body (9) is cardanic is suspended, a second inertial body (15, 19, 21) with at most the same size Mass moment of inertia like the first inertia body (9) movable on the latter is mounted and the trigger arm (17) one close to the second inertia body (15, 19, 21) arranged curved2 surface (18). 2. Sensor according to claim 1, characterized in that the second Inertia body is an IL-sleeve (15). 3. Sensor according to claim 1, characterized in that the second Inertial body is a ball (19). 4. Sensor according to claim 1, characterized in that the second Inertial body consists of several ICinpsegmenten (21). 5. Sersor according to one of claims 1-4, characterized in that the holder fixed to the housing has an outer frame (12) with two diametrically arranged recesses (31) for receiving pins (13, 13 ') shafts or the like is provided. 6. Sensor according to one of the requirements 1-5, that is to say it is not indicated that the cardanic suspension has an inner rabmen (10'10 '), has on which cardanic pins (11, 11 ') and / or pins (13, 13') fastened are. 7. Sensor according to one of the requirements 1-6 d a d u r c h g e k It is noted that the inner frame (10, 10 ') is movable in the outer frame (12) is stored. 8. Sensor according to one of claims 1-7, characterized in that that the frame (10, 10 ', 12) is a ring, preferably a partial ring (Fig. 11A). 9. Sensor according to one of claims 1-7, characterized in that the frame (10, 12) is out of round, preferably rectangular. 10.Sensor according to one of claims 1-9, characterized in that dr first inertial body (9) is a pendulum which is perpendicular in its rest position and which has a tunnel (36) open at the bottom or lateral recesses (36 '). 11. Sensor according to one of claims 1-10, characterized in that that in the neck (15) two aligned recesses; (20) are provided. 12. Sensor according to one of the test 1-10, d a d u r c h g e k e n n n nt indicates that a protruding on the top of the pendulum (9), centrally arranged cupped pin (37) is attached, which of the second Trögeitskörper (15, 21) is included.