DE29601148U1 - Hazard warning flashers - Google Patents

Description

Georg Hagmeier

23.01.1996

Wamblink arrangement

The invention relates to a warning flashing arrangement for a vehicle, which is automatically switched on under certain operating conditions.

Practice shows that significant, avoidable economic damage is caused by the hazard warning lights being switched on too late or not at all in motor vehicle accidents, and that this often leads to additional rear-end collisions. Accidents resulting in death often only occur as a result of such rear-end collisions. It would also often be helpful if the hazard warning lights were switched on automatically in the case of "emergency braking", i.e. braking with a strong deceleration, e.g. of 0.8 g or more, in order to warn the following traffic in good time before an accident even occurs. Some drivers already do this by manually switching on their vehicle's hazard warning lights when approaching an unexpected traffic jam in order to avoid damage caused by following vehicles rear-ending if possible.

The practical introduction of an automatic activation of the warning flasher arrangement has so far been prevented by the fact that no warning flasher arrangement was available that would meet all the diverse practical conditions. In the event of a crash, it is possible and is also practiced to activate such a system using the airbag sensor, but it is desirable, for example, to achieve automatic activation of the warning flasher arrangement even below the airbag's response threshold, e.g. in the event of emergency or hazard braking. In practice, however, such a wide variety of boundary conditions arise that previous attempts in this direction have always led to a negative result.

The aim of the invention is therefore to reduce the risks involved in operating a motor vehicle.

This object is achieved according to the invention by a hazard warning system for a vehicle, with a first sensor which responds quickly to high accelerations and/or decelerations by sending a signal to switch on the hazard warning system, and with a second sensor which responds to negative accelerations, such as those that occur during emergency braking, only after a time delay by generating a signal to switch on the hazard warning system, this signal being generated when a high negative acceleration acts on the second sensor during a predetermined shorter period of time or a less high negative acceleration acts on the second sensor during a predetermined longer period of time.

This means that such a warning flashing arrangement is switched on by the first sensor when, for example, a collision with its strong decelerations occurs, whether due to the vehicle driving into another or due to another vehicle driving into the vehicle from behind, and that the hazard warning arrangement is automatically switched on by the second sensor when an emergency braking occurs, whereby short-term emergency braking does not trigger a response, but only those that are effective for a certain minimum period, whereby this time decreases as the magnitude of the negative acceleration increases.

Further details and advantageous developments of the invention will become apparent from the embodiments described below and shown in the drawing, which are in no way to be understood as a limitation of the invention. It shows:

Fig. 1 is a schematic diagram of an acceleration sensor that can be used in the invention, viewed in the direction of arrow I in Fig. 2,

Fig. 2 is a section taken along the line ll-ll of Fig. 1,

Fig. 3 shows a representation of the acceleration sensor of Figures 1

and 2 usable basic circuit, in which an additional delay switch is provided, which is also referred to as a crash sensor,

Fig. 4 is a detailed view of an embodiment of a suitable circuit, also with an additional delay switch,

Fig. 5 is a schematic diagram showing the position of the acceleration sensor and the deceleration switch in a motor vehicle as an example,

Fig. 6 shows a representation of a sensor arrangement in an embodiment which can be particularly advantageous for use on motor vehicles, this sensor arrangement also containing a delay switch,

Fig. 7 shows an example of an inexpensive and practical design of a delay switch.

Fig. 8 is a circuit diagram of a preferred arrangement for automatically switching on the hazard warning lights of a motor vehicle in dangerous situations,

Fig. 9 a detail of Fig. 8,

Fig. 10 is an exploded view of a preferred embodiment of a delay switch,

Fig. 11 the delay switch of Fig. 10 in the assembled state,

Fig. 12 is a detail of Fig. 11, and
Fig. 13 a variant of Fig. 8.

Fig. 1 shows the basic structure of a sensor 80, as is preferably used within the scope of the invention. This contains a curved tube 85, the curvature of which is shown as relatively large in the various figures, but is actually quite small, ie the radius of curvature R is, for example, in the order of magnitude of 0.8 to 1 m, occasionally even higher. This curved tube 85 with a circular cross-section is usually made of glass and is welded at both ends 87, 88 in a liquid-tight manner. Its convex side 84 faces the center of the earth in the position of use. The tube 85 contains a metal ball 86, the diameter of which is slightly smaller than the inner diameter of the tube 85, so that the ball 86 can roll in the tube 85 when the latter changes its inclination or when a positive or negative acceleration acts on the sensor 80.

The tube 85 is filled with a damping fluid 89. The filling volume is selected so that the tube 85 is not completely full at room temperature, so that thermal expansion of the fluid 89 is possible. The fluid 89 primarily dampens the movements of the ball 86 during vibrations with a higher frequency, as regularly occur during operation of a motor vehicle.

In the area of the ends 87, 88 of the tube 85, an inductive proximity switch 90 or 91 is arranged. Such inductive proximity switches can, for example, have the structure according to FR-A 2 155 885 and are not described in detail as common components. Siemens AG, for example, offers the IC with the type designation TCA 505 for such proximity switches, as well as corresponding coil cores, i.e. the structure of an inductive proximity switch shown here is in principle state of the art. Reference can be made to the data sheet for the TCA 505. The oscillator frequency of this switch is preferably between 0.3 and 1 MHz.

The proximity switches 90 and 91 are designed in such a way that they each detect the presence of the ball 86 in these end positions, i.e. when the end position is reached at the relevant end 87 or 88 of the curved tube 85.

Fig. 3 shows the basic circuit of the two proximity switches 90 and 91 of the sensor 80. Each of them is connected to a threshold switch 92 or 93, respectively, and to these is connected a time switch 94 or 95, respectively, which only switches on after an adjustable time delay, eg after a delay of 0 to 2 seconds. In the invention, a delay in the range of 0 seconds is preferably used, ie when, for example, the ball 86 reaches its end position 87, the relay 96 responds immediately and closes a switch 100.

According to Fig. 5, the sensor 80 is installed longitudinally in a motor vehicle 70 so that it acts as a sensor for negative accelerations (decelerations), i.e. when the vehicle 70 brakes, the ball 86 moves forward, i.e. to the left, and simultaneously upwards, with its movement being dampened by the damping fluid 89 (Fig. 2). Since the ball 86 has to move uphill due to the curvature of the tube 84, its position in the tube 84 represents a measure of the deceleration that occurs. Only in the case of prolonged, strong decelerations, such as those that occur during emergency braking, does the ball 86 move to the end position and cause the proximity switch 90 to respond and thus the contact 100 to close.

Such a sensor switches

a) depending on its position relative to the horizontal, i.e. when the vehicle is travelling downhill, it switches more quickly than when travelling uphill, taking into account the fact that lower deceleration values are possible when travelling downhill than when travelling uphill;

b) depending on the magnitude of the negative acceleration; and

c) depends on the duration of the deceleration, i.e., depends on the integral of the force acting on ball 86 over time.

This means that a longer, weaker delay has approximately the same effect as a shorter, stronger delay, i.e.

the sensor 80 has something like built-in intelligence. The sensor 80 only emits a signal to switch on the hazard warning lights when this integral exceeds a predefined limit value, and the initial value of the integration, i.e. the integration constant, also depends on whether the vehicle is driving on a flat stretch of road, uphill, or downhill.

Tests have shown that with such a sensor, the signal is only given if it is actually necessary in practice, i.e. such a hazard warning system only switches on in dangerous situations, but reliably.

In addition to the contact 100, and parallel to it, a contact 150 is provided, on which a schematically shown eccentric 152 acts, to which a weight 156 is connected via a lever 154. During normal travel, the lever 154 is held in the position shown by a schematically shown spring 158, in which the eccentric 152 assumes a position such that the contact 150 is open. Alternatively, the switch 301 shown in Figs. 10 to 12 can be used instead of the contact 150.

If a strong deceleration occurs, as is typical for a crash, the lever 154 moves clockwise against the force of the spring 158 and thereby rotates the eccentric disk 152 so that the contact 150 is closed. As can be seen, closing the contact 150 has the same effect as closing the contact 100, but while the contact 100 is already closed during emergency braking, in practice the contact 150 is only closed during a crash, thus supplementing the effect of the sensor arrangement with the contact 100 in the direction of high, very short-term deceleration values, as are typical for an (active or passive) crash.

According to Fig. 3, the signal from contact 100 or from contact 150 is fed to a logic circuit 103, which stores this signal internally and uses the stored signal at its output 104 to generate a hazard warning system.

106 is switched on. This supplies the lights 110, 111 (see also Fig. 5) with the corresponding current pulses for the direction indicator via diodes 107, 108. These lights can also receive pulse signals for the direction indicator via lines 114, 115 - from an on-board flasher not shown in Fig. 3.

A manually operable switching contact 120 is used to delete the signal stored in the logic circuit 103, which can also be used to switch on the "normal" hazard warning system of the vehicle 70. This normal hazard warning system is not shown, since its structure is known to the person skilled in the art.

If, as shown in Fig. 5, the vehicle 70 moves forward, i.e. in the direction of arrow 72, the ball 86 remains in its lowest position in the glass tube 85 at a constant speed. This rest position is shown in all figures. The proximity switch 90 does not respond in this case. Movements of the ball 86 as a result of shocks or vibrations are strongly dampened by the liquid 89.

If the vehicle 70 is decelerated in the usual way, e.g. when stopping at a traffic light, the ball 86 moves in the direction of travel but does not reach the end position 87, so that in this case too the proximity switch 90 does not respond.

Only in the event of a prolonged emergency braking does the ball 86 reach the end position 87 and trigger the proximity switch 90. In the event of a crash with its short-term, high deceleration values, it is not certain that the proximity switch 90 will always trigger, but in this case the signal is triggered by the contact 150, which is closed by the lever 154 and the weight 156, which weight, as described, performs a corresponding clockwise movement in the event of such a crash. The spring 158 is designed in such a way that the contact 150 is not closed in the event of an emergency braking with its lower deceleration values.

At the end of an emergency braking maneuver, i.e. when the vehicle 70 has come to a standstill, the ball 86 returns to the central position shown, the relay 96 is de-energized, and the contact 100 is opened again. The same applies in the event of a crash, i.e. in such a case, when the vehicle has come to a standstill again, the contact 150 is opened again by the action of the spring 158.

By closing the contact 100 during emergency braking, or by closing the contact 150 during a crash, the logic circuit 103 receives a corresponding signal, which is stored in it so that it remains available even when the contact 100 and/or 150 has opened again. The stored signal causes an output signal at the output 104, which switches on the hazard warning system 106, and this then sends current pulses to the lights 110, 111 in the usual way so that they flash and give a corresponding warning signal to the following traffic or to the traffic approaching the accident site.

The logic circuit 103 can then be reset by the driver by activating the contact 120, whereby the storage described is deleted. The contact 120 can be part of the switch with which the warning flashing system of the vehicle (not shown) can be switched on and off. By switching on the warning flashing system of the vehicle (not shown), a signal that is stored in the logic circuit 103 is deleted. The following Figs. 8 and 9 show a preferred embodiment for this.

Fig. 4 shows an example of a circuit that can be used in a motor vehicle. Parts that are the same or have the same effect as in the previous figures are designated by the same reference numerals as there and are usually not described again.

The logic circuit 103 contains a normally closed relay 125 and a normally open relay 126. The connections of these relays are designated with the standardized designations, e.g. 85 and 86 for the coils. To distinguish them from the reference symbols, these standardized

An A has been added to the designations, e.g. A85 and A86. This also applies to the Wamblink arrangement 106, which is shown here as a standard Wamblink relay.

As shown in Fig. 4, the switch 120 for deleting the signal stored in the logic circuit 103 is arranged between a positive line 130 and the input A85 of the normally closed relay 125. When the switch 120 is closed, it causes an interruption between the terminals A30 and A87a of the relay 125, of which the terminal A87a is connected to the positive line 130 and the terminal A30 to the terminal A87 of the normally open relay 126. The terminals A86 of both relays 125, 126 are connected to ground, as shown.

The contact 100 of the relay 96 in the sensor 80 is, as is the contact 150 of the delay switch 160, connected to the terminals A30 and A85 of the relay 126, as well as to the terminal A49 of the hazard warning relay 106.

As shown, the switch 120 may include a second contact 120a for activating the usual hazard warning lights (not shown) of the vehicle 70. However, the contact 120 may also perform both functions, as described below in Fig. 8.

How it works

If contact 100 is closed in the manner already described during an emergency braking of the vehicle 70, or if contact 150 of the deceleration switch 160 is closed during a crash, the winding 135 of the normally open relay 126 receives current, so that its contact 136 connects the terminals A30 and A87 of this relay. This creates a connection from the positive line 130 via the terminals A87a and A30 of the relay 125 and the terminals A87 and A30 of the relay 126 to the coil 135, so that the latter is constantly supplied with current and stores the signal from contact 100, even if it opens again after the deceleration. A signal is also stored from contact 150, even if it opens again after a crash. In this way, the

Connection A49 of the hazard warning relay 106 is supplied with current and causes the vehicle’s lights 110, 111 to flash.

If the switch 120, 120a is now operated, the winding 138 of the relay 125 receives current and its contact 140 opens the connection between the terminals A87a and A30 of the relay 125. This de-energizes the relays 106 and 126 and the flashing stops.

It is clear that in the sensor 80 according to Fig. 3, the proximity switch 91 as well as the parts 93, 95 and 97 can be omitted, since they have no function, unless additional protection for rear-end collisions or for reversing is desired, because in such a case the hazard warning system can also be switched on via the proximity switch 91 in the manner shown. A further, additional deceleration sensor can also be provided for this case.

Fig. 6 shows a variant with a sensor arrangement 80' which, according to current knowledge, is optimally adapted for use in a motor vehicle.

The axis of symmetry 145 of the curved tube 85 with a circular cross-section is shifted here relative to the vertical 146 by an angle alpha in the direction of travel 72, just as shown purely schematically in Fig. 4. Empirically determined, this angle can be in the range of 30 to 40°, depending on the dimensions of the tube 85 and its radius of curvature R, which can naturally also be very large or have the value infinite. The ball 86 is therefore located here in the (shown) rest position not far from the right end 88 of the tube 85, so that its path to the left end 87, i.e. until the proximity switch 90 is activated, is relatively large.

Otherwise, the parts of Fig. 6 correspond, also in terms of their function, to the corresponding parts of Fig. 3. This also applies to the delay switch 160 with its contact 150, which is why these parts are not described again. The tube 85 is also provided with a

* · • i ft t

*· 1

Filled with damping fluid 89. It has been shown in practice that a sensor 80' constructed in this way is particularly suitable for signaling in a motor vehicle, so that, for example, the sensor arrangement 80' can also respond when emergency braking occurs in the rain.

In addition to the proximity switch 90, additional proximity switches (not shown) can be provided in the sensor arrangement 80 or 80', which detect intermediate positions of the ball 86 between the rest position shown and the end position 87, and the output signals of the various proximity switches can then be processed in a microprocessor according to a predetermined algorithm.

Fig. 7 shows a simple design for the delay switch 160. A limit switch from Marquardt was used here, which can be operated by turning a shaft 162 clockwise. A spring arranged in the switch 160 counteracts such a rotation. The designation of the microswitch used here as an example is 1040.0101 μ 4(1)/250++++T85. This type of switch normally has a button attached to the shaft 162, and this is replaced here by the downwardly hanging weight 156, which is attached to the shaft 162 via the lever 154. The direction of travel is designated 72.

In the event of a strong deceleration, the weight 156 moves clockwise to position 156' and thereby closes the contact 150 provided in the switch 160, which is not visible in Fig. 7. When the deceleration is over, the weight returns from position 156' to the rest position 156 under the action of the spring provided in the switch 160. The spring in the switch 160 is designed in such a way that, in conjunction with the weight 156, it enables the switch to respond only at high deceleration values.

A preferred embodiment of a delay switch is shown in the following Figs. 10 to 12.

Fig. 8 shows the preferred structure of an arrangement according to the invention. This contains two sensors, namely a sensor 80 analogous to Fig.

1 to 3 or Fig. 6, and secondly a delay switch 301, eg of the type shown in Fig. 7, but preferably of the type shown in Figs. 1 to 12, ie a sensor which reacts without delay to accelerations or decelerations which exceed a certain value, eg 2.5 g (g = acceleration due to gravity, 9.81 m/s ² ). The contact 303 provided in the sensor 301 is connected via a series resistor 201 to a positive line 226, eg + 12 V.

Since the signal from sensor 301 may only be effective for a very short time, e.g. only for 100 ms, it is fed via a capacitor 202 to a monostable multivibrator 204, which generates, for example, a positive pulse 208 with a duration of 3 seconds at its output 206, if contact 303 in sensor 301 closes even briefly because a strong acceleration or deceleration has occurred.

This positive pulse is fed to an input 212 of the coil of a switching relay 210, the other input 214 of which is connected to ground via an npn transistor 216. As long as the vehicle's on-board flasher, designated 218, does not emit any hazard warning pulses, this transistor 216 is kept conductive. For this purpose, a relatively high-resistance resistor 230 is provided between its base and the positive line 226, via which the transistor 216 receives a base current. A freewheeling diode 220 is located between the inputs 214 and 212, as shown.

When relay 210 receives power from either sensor 80 or delay switch 301 (via monoflop 204), its moving contact 223 switches to fixed contact 224, which is connected to positive line 226, and it supplies a positive potential to input 212 via diode 228, so that relay 210 is latched.

The process described (switching relay 210 to self-holding) takes place in the same way if sensor 80 supplies a positive signal to relay 210 via a diode 234 during a strong, long-term delay. Sensor 80 only responds if, for example, an emergency braking operation occurs with strong deceleration and corresponding dynamics. The generation of the

Signal in sensor 80 or 80' is dynamically delayed, i.e.

a) depends on the force acting on the ball 86, i.e. depends on the amount of the negative acceleration, and

b) depending on the time during which this force acts on the ball 86, i.e. depending on the time during which the emergency braking takes place. Only when the product of these two influences, i.e. the force acting on the ball 86 and the duration of its action, or, more precisely, the integral of this force over time, exceeds a predetermined value, does the ball 86 reach the area of the proximity switch 90, and only then is a signal triggered and the hazard warning lights switched on immediately.

If the integral over time does not reach a specified threshold value, e.g. in all normal driving situations, no signal is generated and consequently the hazard warning lights are not triggered.

This is in contrast to known arrangements where, in the event of a deceleration above a predetermined value, a signal is immediately triggered and this is delayed electronically, whereby naturally neither the magnitude of the negative acceleration nor its duration are included in the result, which is why satisfactory results are not possible with this.

The diodes 228, 234 prevent overloading of the electronic components provided in the sensor 80. The process described also takes place if the delay switch 301 responds, even briefly, and the monoflop 204 therefore emits a signal 208.

When the moving contact 223 is connected to the fixed contact 224, a hazard warning relay 240 also receives a positive potential at its input 242 and starts to generate positive pulses 244 at its output 246. These pulses can be displayed by means of a control lamp 248 on the dashboard of the vehicle, since this hazard warning relay 240 is automatically switched on in certain dangerous situations and the driver must be made aware of this so that he switches this relay off again once the dangerous situation has ended.

The positive potential at the movable contact 223 also switches on two switching relays 250, 252, which, in the de-energized state, as shown, connect the right-hand indicator lights 254 to the right output 258 of the on-board indicator 218 and the left-hand indicator lights 256 to the left output of the on-board indicator 218.

If the relays 250, 252 receive power, they separate these flashing lights 254, 256 from the on-board flasher 218 and connect them to the output 246 of the hazard warning relay 240, so that the hazard warning pulses 244 are fed to them from there, and consequently the vehicle emits a hazard warning signal on all flashing lights. This happens automatically in dangerous situations, e.g. in the event of emergency braking or in the event of an active or passive rear-end collision.

The two inputs of an AND gate 266 are connected to the outputs 258, of the on-board indicator 218, and an inverter 268 is connected to the output of this AND gate, the output of which is connected to the base of the transistor 216.

If both outputs 258, 260, or at least one of them, have ground potential, the output of the AND gate 266 is low, and a high potential is consequently obtained at the output of the inverter 268, so that the transistor 216 conducts.

If the on-board flasher 218 is used as a hazard warning light, synchronous positive pulses are generated at its two outputs 258, 260, and these cause a positive signal at the output of the AND gate 266. This positive signal is inverted via the inverter 268 and blocks the transistor 216, which de-energizes the relay 210, and thereby also the hazard warning relay 240 and the two changeover relays 250 and 252, so that they switch back to the de-energized state in which the flashing lights 254, 256 are connected to the on-board flasher 218.

As soon as the hazard warning system (on-board flasher relay 218) of the vehicle is switched on by the driver, the hazard warning relay is activated via the AND gate 266.

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240 is de-energized, i.e. the additional hazard warning flashing arrangement shown in Fig. 8 is deactivated again.

A significant advantage of the arrangement described is that, unlike in Fig. 4, no mechanical intervention is necessary in the manual switch 219 of the vehicle, with which the hazard warning lights are switched on and off. Switching on this switch 219 automatically causes the transistor 216 to be blocked, and this automatically results in the relays 210, 240, 250 and 252 being de-energized and the flashing lights 254, 256 being reconnected to the corresponding outputs 258 and 260 of the on-board flasher 218.

Fig. 9 shows a practical embodiment of the conjunctive connection. As shown there, two npn transistors 272 and 274 are connected in series and arranged between the base of the transistor 216 and ground. The base of the transistor 272 is connected via a resistor 276 to the output 258 of the on-board indicator 218, and the base of the transistor 274 is likewise connected via a resistor 278 to the output 260 of the on-board indicator 218. The base of the transistor 216 receives a base current via the resistor 230 as long as the two transistors 272, 274 are not simultaneously conductive, so that in this case the transistor 216 is conductive.

If the on-board indicator 218 generates pulses at its output 258 (for the right indicator lights 254) when turning right, these pulses turn on transistor 272, but not transistor 274, which remains blocked.

This also applies if the on-board indicator 218 generates pulses at its output 260 (for the left indicator lights 256), i.e. then the transistor 274 becomes conductive, but not the transistor 272.

However, if the on-board indicator 218 generates warning flashing pulses at both outputs 258, 260 after the warning flashing switch 219 has been activated, both transistors 272 and 274 become conductive and thereby connect the base of the transistor 216 to ground, so that this transistor 216 does not generate any base current.

no longer receives any power and becomes non-conductive. This also causes relays 210, 240, 250 and 252 to become non-conductive, as already described.

In this way, when the on-board indicator 218 is activated as a hazard warning light, the transistor 216 is automatically blocked and the system is switched back to the on-board system. By switching off the on-board system, the hazard warning signals can then be switched off completely. Such a hazard warning system can therefore be easily retrofitted in a vehicle.

In this way, any intervention in the on-board flashing system is avoided - apart from the connection of the contacts of the two relays 250, 252 in the circuits of the indicator lights 254, 256 - and since the relays 250, 252 do not change the configuration of the on-board flashing system when the power is off, even a fault cannot affect the correct functioning of the vehicle's indicators.

Naturally, there are many ways of effecting a shutdown by means of a conjunctive linking of the signals at the outputs 258, 260, and the representations according to Figs. 8 and 9 are therefore to be understood only as examples.

Fig. 10 shows the preferred construction of a deceleration or crash sensor 301 in an exploded, enlarged view, Fig. 11 in the assembled state.

A metal coil spring 302 is attached to an insulating support part 300. This has a metal part 304 at its free end, which tapers to a truncated cone at its end 306 facing away from the spring 302 and is otherwise cylindrical.

The coil spring 302 is preferably wound "on a block", ie its wire windings 308 are pre-tensioned against each other in the resting state, as shown in Fig. 12. By way of example, it can be stated that the spring 302 is made of steel wire with a diameter of 0.6 mm and has a

17

can have an outer diameter of 5 mm.

As best seen in Fig. 11, the support member 300 is mounted in the open end of a cup-shaped metal member 310 which, in use, can be connected to ground 312 as shown, while the coil spring 302 is connected to an external terminal 314.

Fig. 11 shows the sensor in its position of use. A hanging arrangement would also be possible, but the standing arrangement according to Fig. 11 is currently preferred.

How Fig. 10 to 12 work

If the sensor 301 is subjected to an acceleration or deceleration in the horizontal direction or with a horizontal component that exceeds a certain value, the spring 302 is bent. The metal part 304 moves in the direction of the arrow 316 and comes into contact with the metal housing 310, so that an electrical connection is established between the terminals 312 and 314, which serves to automatically trigger the hazard warning lights of the vehicle on which the sensor 301 is located.

It is advantageous that the sensor 301 responds to accelerations and decelerations in all directions that can occur when a motor vehicle is operating, e.g. also in the case of rear-end collisions in which a third party drives into the vehicle with the sensor, or when the vehicle rolls over, etc. Because the windings 308 are wound in a block, the coil spring 302 is very stiff and therefore only responds when a certain minimum value of acceleration or deceleration is reached. This has the advantage that false signals are reliably avoided.

For the purpose of adjustment, the helical spring 302 in the part 300 can be adjusted by turning, whereby its effective section a is lengthened or shortened. The spring 302 can then be fixed in the part 300 so that it cannot rotate, e.g. by thermally compressing the plastic of the part 300 or by gluing.

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As an example, the outer diameter of the cup-shaped part 310 can be 20 mm, its length 25 mm, and the distance a approximately 5 mm. If the acceleration value at which the sensor 301 responds is referred to as GW (e.g. 2.5 g), tests have shown that the metal part 304 practically does not move relative to the part 310 at accelerations/decelerations of less than 0.5 GW, i.e. the spring 302 acts like a rigid part in this range, i.e. during normal driving. Only from 0.5 GW, i.e. from 1.25 g, does the spring 302 begin to bend, i.e. the part 304 then moves sideways towards the part 310. Contact between 304 and 310 only occurs at the set value GW.

This results in a very simple sensor for all directions with a horizontal component and with very good response accuracy.

Fig. 13 shows a variant of Fig. 8. Here, a diode 284 is connected between the output 258 of the on-board flasher 218 and the right-hand flasher lights 254, as well as a diode 286 between the output 260 and the left-hand flasher lights 256.

The output 246 of the hazard warning relay 240 is also connected via a diode 288 to the right-hand flashing lights 254 and via a diode 290 to the left-hand flashing lights 256. As soon as one of the hazard warning relays 218 or 240 is in operation, hazard warning signals are generated, but actuation of the on-board flasher 218 automatically results - via the AND gate 266 - in the hazard warning relay 240 being switched off. As a result, both relays 250, 252 in Fig. 8 are saved.

Naturally, numerous variations and modifications are possible within the scope of the present invention. For example, the electrical output signal of a deceleration sensor can also be electronically integrated and trigger the warning flashing arrangement when a threshold value is reached, but the solution shown is preferred.

Claims (24)

• · » ♦ 19 claims 1. Hazard warning system for a vehicle (70), with a first sensor (160; 301) which responds quickly to high accelerations and/or decelerations by signaling in order to switch on the hazard warning system, and with a second sensor (80; 80') which responds to negative accelerations, such as those that occur during emergency braking, only after a time delay by generating a signal (208) to switch on the hazard warning system, this signal generation taking place when a high negative acceleration acts on the second sensor (80; 80') during a predetermined shorter period of time or a less high negative acceleration acts on the second sensor (80; 80') during a predetermined longer period of time. 2. Hazard warning system in which the delay in response at the second sensor (80; 80') is additionally a function of whether the braking occurs when driving uphill, on a level stretch of road, or when driving downhill. 3. Hazard warning system according to claim 1 or 2, in which the second sensor (80; 80') has a liquid-filled tube (85) which is arranged at a predetermined inclination in the vehicle and in which a ball is arranged with a small amount of play, the position of which in the tube is detected without contact. 4. Hazard warning system according to claim 3, wherein the liquid-filled tube is arranged in the vehicle such that it is at a greater distance from the roadway on its side facing the front end of the vehicle than on its side facing the rear end of the vehicle. 5. Hazard warning system according to claim 3 or 4, wherein the inclination of the 20 pipe is between 30 and 40° to the horizontal. 6. Wamblink arrangement according to one or more of claims 3 to 5, in which the ball is a metal ball to which an inductive proximity switch is assigned for contactless scanning. 7. Warning flasher arrangement according to one or more of the preceding claims, in which an additional hazard flasher (240) different from the on-board flasher (218) of the vehicle and a deactivation arrangement (266, 268, 216) are provided, the latter deactivating the additional hazard flasher (240) when the on-board flasher (218) is actuated. 8. Warning flasher arrangement according to claim 7, in which the deactivation arrangement has an arrangement (266) for conjunctive linking the flashing pulses emitted by the on-board flasher (218) for the left and right flashing lights (256 and 254, respectively) in order to deactivate the additional hazard flasher (240) when flashing pulses for the right flashing lights (254) and the left flashing lights (256) occur simultaneously. 9. Warning light arrangement according to one or more of the preceding claims, in which a sensor is provided as the first sensor (301), which reacts essentially equally to all deceleration forces acting on it in the horizontal direction with regard to signaling. 10. Warning flasher arrangement according to claim 9, in which the first sensor (301) has a movable mass (304) which is connected to a part (300) fixed to the vehicle via a coil spring (302). 11. Wamblink arrangement according to claim 10, in which the coil spring (302) has turns (308) which abut against one another. ••t» 12. Wamblink arrangement according to claim 11, in which the windings (308) are prestressed against one another. 13. Warning light arrangement according to one or more of claims 10 to 12, in which, in the position of use, the movable mass (304) is arranged above the coil spring (302) and is connected by the latter to a vehicle-fixed part (300). 14. Wamblink arrangement according to one or more of claims 10 to 13, in which the movable mass (304) is designed as a movable contact and a surrounding housing (310) which is electrically conductive at least on the inside is designed as a fixed contact, wherein contact between these two contacts triggers a sensor signal. 15. Warning flashing arrangement according to one or more of the preceding claims, in which the first sensor (160; 301) is assigned an electronic switching element in the form of a monostable multivibrator (204) which, when the first sensor is actuated by a strong acceleration or deceleration during a predetermined period of time, generates an output signal (208) for switching on the warning flashing arrangement. 16. Warning flashing arrangement according to one or more of the preceding claims, in which after switching on by the first and/or second sensor (301 or 80, 80'), the generation of warning flashing signals (244) is automatically continued by the warning flashing arrangement. 17. Warning flashing arrangement according to claim 16, in which the generation of warning flashing signals (244) by the warning flashing arrangement is interrupted when hazard warning flashing signals are generated by a flashing arrangement (218) of the vehicle (70) serving to generate flashing signals. 22 18. Hazard warning system for a vehicle (70), with a first sensor (160; 301) which responds quickly to high accelerations and/or decelerations of the first type by signaling in order to switch on the hazard warning system, further with a second sensor (80; 80') which responds to longer-lasting accelerations and/or decelerations of the second type, which are smaller in magnitude than the accelerations and/or decelerations of the first type, in order to also switch on the hazard warning system, and with a switch-off device (266, 268, 216) for the hazard warning flashing arrangement, which switch-off device can be activated by the conjunctive linking of hazard warning flashing signals emitted by a vehicle-specific flashing arrangement (218). 19. Warning flashing arrangement for a vehicle (70), with a sensor (301) which responds quickly to high accelerations and/or decelerations by signaling in order to switch on the warning flashing arrangement, which sensor (301) has a movable mass (304) which is connected to a part (300) fixed to the vehicle via a coil spring (302). 20. Wamblink arrangement according to claim 19, in which the coil spring (302) has turns (308) which abut against one another. 21. Wamblink arrangement according to claim 20, in which the windings (308) are prestressed against one another. 22. Warning light arrangement according to one or more of claims 19 to 21, in which, in the position of use, the movable mass (304) is arranged above the coil spring (302) and is connected by the latter to a part (300) fixed to the vehicle. 23. Wamblink arrangement according to one or more of claims 19 to 22, in which the movable mass (304) is designed as a movable contact and a surrounding housing (310) which is electrically conductive at least on its inside is designed as a fixed contact, wherein contact between these two contacts causes a sensor signal. I !· 23 24. Hazard warning system according to one or more of claims 19 to 23, in which the sensor (301) is assigned an electronic switching element in the manner of a monostable multivibrator (204), which generates an output signal (208) for switching on the hazard warning system when the first sensor is actuated by a strong acceleration or deceleration during a predetermined period of time.