WO2005123426A1

WO2005123426A1 - Tire protection system

Info

Publication number: WO2005123426A1
Application number: PCT/EP2005/006129
Authority: WO
Inventors: Wolf Boll
Original assignee: Daimlerchrysler Ag
Priority date: 2004-06-17
Filing date: 2005-06-08
Publication date: 2005-12-29
Also published as: DE102004033898A1

Abstract

The invention relates to a method for protecting a tire of the wheel of a vehicle (1), wherein the vehicle wheel (2-5) including the tire to be protected is relieved in the instance of a predetermined situation or condition. The inventive method is characterized in that the tire pressure of at least one tire of a vehicle (1) is detected and monitored, and, if a pressure loss is detected in the tire or the tire pressure in a tire is too low compared to a reference pressure, the respective vehicle wheel (2-5) is relieved, thereby substantially avoiding damages to the tire and making it possible to still drive the vehicle.

Description

Tire Protection System

The invention relates to a method for protecting a tire of a wheel of a vehicle, in which the vehicle wheel with the tire to be protected is relieved in the presence of a predetermined situation or condition. The invention also relates to a system for protecting a tire of a wheel of a vehicle.

If there is a loss of pressure in the tire of a vehicle, the tire is often defective. If such a tire is loaded normally, further damage to the tire can occur. This also applies to tires with run-flat properties. Likewise, damage to a tire can occur if this tire has a tire pressure value that is too low in comparison to a predetermined reference pressure value. This too low tire pressure value does not necessarily have to result from a pressure loss, it can also occur, for example, after changing a tire, for example changing from summer tires to winter tires or changing to a spare tire, if the tire is not properly inflated. The specified reference pressure value can either be a tire pressure value specified for the respective vehicle type and stored in a storage means arranged in the vehicle, or this reference pressure value is determined from the tire pressure values of the remaining tires of the vehicle, for example by averaging, provided that these tire pressure values only differ from one another by a predetermined small value.

The tire load is made up of the spring load and the shock absorber force. The run-flat properties of a tire with insufficient air pressure depend heavily on the wheel load. In particular, peak loads, e.g. caused by bumps, can damage the tire, i.e. squeeze the side flanks.

It is known from EP 0 929 427 B1 to relieve a damaged vehicle wheel. It is also known to relieve the vehicle wheel diagonally opposite the defective vehicle wheel and to shift the vehicle weight onto the wheels of the other vehicle diagonals.

It is the object of the present invention to extend the remaining emergency running distance in the event of a pressure loss of a tire or if the tire pressure value of a tire is too low in comparison to a reference pressure value, in particular if the tire begins to flatten or is completely flat, the remaining running distance is increased, depending on the tire damage to get to the day's destination or the nearest workshop or down the highway.

According to the invention, this object is achieved by a method mentioned at the outset, in which the tire pressure for at least one tire of the vehicle is recorded and monitored, and if the pressure loss in a tire is detected or if the tire pressure value in a tire is too low in comparison with a reference pressure value, the corresponding vehicle wheel is relieved. This measure can damage the tire at all or further damage the tire. can be prevented. The remaining running distance or the emergency running distance can be extended considerably by this measure. In particular, the pressure can be relieved even at the beginning of a pressure loss, so that the further pressure loss is slowed down. In addition, the vehicle remains drivable and controllable for longer.

In a preferred variant of the method it is provided that the wheel load is shifted to the diagonal of the vehicle that does not include the tire with a pressure loss or a tire pressure that is too low. It can be provided that if a tire pressure loss or a tire pressure that is too low is determined by a networked, on-board diagnostic device, this is communicated to a chassis control unit, so that the tire pressure is relieved with the lower air pressure. This relief takes place in four-wheel vehicles, i.e. vehicles with two axles, in that the wheel diagonal, on which the tire to be relieved or damaged is located, is relieved by a lower spring force and the missing load capacity is transferred to the other wheel diagonal. This shifting of the wheel load can be brought about by influencing an air suspension or an air spring system, a level control or a level control device and / or by interlacing one or two cross stabilizers, which are in particular designed as active cross stabilizers. The same procedure is used for vehicles with more than two axles.

In a preferred method variant it can be provided that the damping behavior, in particular the damping characteristic of the vehicle, is changed on at least one wheel. The damping behavior on the wheel that has a pressure loss or one that is too low is preferably changed Has tire pressure value. This means that if there is a loss of pressure in a tire or if the tire pressure value in a tire is too low compared to a reference pressure value, the remaining limp-home route is extended, since bumps on the road increase less than the peak load than would be the case with normal shock absorber tuning , The load peaks are reduced in that when a pressure loss or a tire pressure value of a particular wheel that is too low is determined, a diagnostic device forwards a message to the shock absorber control device, which has the effect that the damping behavior of the at least one wheel is prevented.

Preferably, at least on the shock absorber, which is assigned to the vehicle wheel to be relieved, in comparison to the setting of the shock absorbers assigned to the remaining wheels, the compression stage is set softer and the rebound stage is set harder. The remaining wheels should preferably be the wheels that have defect-free tires.

A further protection of the tire with low air pressure can be achieved by also setting the compression level softer and the rebound level harder on the shock absorber of the wheel diagonally opposite the vehicle wheel to be relieved.

It is also conceivable to set the rebound and compression stages to be harder on the shock absorbers of the remaining wheels. As a result of this measure, the vehicle load is shifted exclusively to wheels which have a normal tire pressure. With this measure, the vehicle can still be kept stable.

The method according to the invention can be implemented in a particularly simple manner in vehicles with a Air suspension or an air suspension system or level control or level control device and / or in vehicles with an active anti-roll bar.

In order to point out to the driver that a tire with a pressure loss or a tire with a tire pressure value that is too low in comparison to a reference pressure value and therefore a tire change is necessary, the driver can advantageously be given a signal so that he is informed about the load shift , This can advantageously be an optical or acoustic signal.

The object is also achieved by a system for protecting a tire of a wheel of a vehicle, in which, in the presence of a predetermined situation or condition, the vehicle wheel with the tire to be protected is relieved, in which a tire pressure sensor system for detecting the tire pressure for at least one tire and one Diagnostic device for evaluating the recorded tire pressures is provided, which is connected to a control unit which controls a load shifting device in such a way that the corresponding vehicle wheel is relieved when a pressure loss in a tire is detected or when the tire pressure value in a tire is too low compared to a reference pressure value , With such a system, a vehicle with a defective tire or with a tire with pressure loss or with a tire pressure value that is too low in comparison to a reference pressure value can be safely driven to a workshop without damaging the tire at all or further.

It is particularly preferred if the load shifting device comprises an air suspension system. By appropriately controlling the shock absorbers or suspension devices of the Air suspension system can relieve a vehicle wheel in a targeted manner or other wheels can be specifically loaded. With this measure, the wheel can be protected with pressure loss or with a tire pressure value that is too low in comparison to a reference pressure value.

Alternatively or additionally, it can be provided that the load shifting device comprises a level regulating device. Even with such a device, a tire can be relieved and protected in a targeted manner.

It is particularly preferred if the load shifting device comprises at least one transverse stabilizer, in particular an actively implemented transverse stabilizer. With an active anti-roll bar, a tire can be relieved in a targeted manner. A roll stabilizer is typically used to reduce the roll of a vehicle when cornering and to prevent rocking on poor roads. If the body only lifts on one side or falls to its knees, the anti-roll bar becomes active and transfers the movement from one side to the other. The one-way static and dynamic forces are distributed on both sides. The lateral inclination is thus automatically suppressed and therefore the vehicle remains more horizontal. There are no "balance disorders". A transverse stabilizer can be provided for the front and / or rear axle. Such transverse stabilizers can also be used to relieve the wheel diagonal on which a tire with a pressure loss or a tire with a tire pressure value that is too low compared to a reference pressure value is relieved by entanglement by a corresponding inclination angle. In vehicles which have a device for influencing the tire pressure, the tire pressure of the defect-free tires can additionally be increased in a suitable manner.

In a preferred embodiment of the invention, the control device is designed as a chassis control device and / or shock absorber control device. This depends on the manner in which a tire with pressure loss or a tire pressure value that is too low in comparison to a reference pressure value is to be relieved and which load shifting device is used. All of the load shifting devices mentioned can be regarded as part of the chassis and can be controlled accordingly by the chassis control unit. The chassis control unit advantageously controls the level control and / or the air suspension and / or the at least one anti-roll bar. The shock absorber control unit advantageously influences the damping characteristics.

A display device is advantageously provided, on which the driver can be shown that a load shift is taking place or has taken place. This also shows the driver that the tire needs to be changed or checked.

Further features and advantages of the invention result from the following description of exemplary embodiments of the invention, with reference to the figures of the drawing, which show details essential to the invention, and from the claims. The individual features can each be implemented individually or in groups in any combination in a variant of the invention. An embodiment is shown in the schematic drawing and is explained in the following description. Show:

1 shows a schematic first illustration of a vehicle;

Fig. 2 is a schematic second representation of a vehicle.

1 shows a vehicle 1 which has four wheels 2 to 5 with tires. A shock absorber 6 to 9 is provided for each wheel 2 to 5. A diagnostic device 10 evaluates the tire pressures measured by a tire pressure sensor system 11 on the tires of the wheels 2 to 5. For reasons of clarity, a tire pressure sensor 11 is shown in FIG. 1 only for the wheel 2. This is not intended to have a restrictive effect. The dashed lines coming from the diagnostic device 10 indicate that a tire pressure sensor is also provided for each of the wheels 3, 4 and 5. The diagnostic device 10 is connected to a control unit 12 which, on the basis of the diagnosis of the diagnostic device 10, controls the shock absorbers 6 to 9 in such a way that the tire of the wheels 2 to 5 which has a pressure loss or a tire pressure value which is too low in comparison with a reference pressure value, is relieved. This means that the damping characteristics of the shock absorbers 6 to 9 are changed. In particular, it can be provided that the pressure level of the damper 6 to 9 of the wheel 2 to 5 with a tire with pressure loss or a tire pressure value that is too low in comparison to a reference pressure value and the rebound level is set harder. In addition, it can be provided that the diagonal of the wheels 3, 5, on which the tire with pressure loss or in Relative to a reference pressure value, the tire pressure value is too low, is relieved and the other diagonal, on which the wheels 2, 4, are subjected to a higher load. In this embodiment, the shock absorbers 6 to 9 form a load transfer device. Alternatively or in addition, the vehicle can be equipped with an air suspension system. In this case, the wheels are assigned 2 to 5 air spring components or suspension devices with which the load can be shifted.

An alternative embodiment is shown in FIG. 2, the vehicle 20 having wheels 21 to 24, the tire pressure of which is evaluated via a diagnostic device 25, which is connected to a tire pressure sensor system 26. For reasons of clarity, a tire pressure sensor 26 is shown in FIG. 2 only for the wheel 21. This is not intended to have a restrictive effect. The dashed lines coming from the diagnostic device 25 indicate that a tire pressure sensor is also provided for each of the wheels 22, 23 and 24. The diagnostic device 25 is connected to a control unit 27, which in turn controls a load shifting device 28 designed as a transverse stabilizer. If, for example, the tire of the wheel 24 has a pressure loss or a tire pressure value that is too low in comparison to a reference pressure value, the diagonal 29 of the vehicle 20 on which the defective tire lies is relieved by the load transfer device 28 and the diagonal 30, ie the wheels 21.23 are burdened more. This shift in load protects the tire of the wheel 24 and prevents further damage. As an alternative or in addition, the vehicle can also be equipped with a level control device and / or an air suspension system to implement the load shifting. A tire with a loss of pressure can be regarded as a defective or damaged tire and can therefore be referred to as such.

If a tire has a pressure loss, its tire pressure decreases over time. There is therefore a change in the tire pressure over time, specifically a decrease in the tire pressure over time.

The tire pressure value, which is too low in comparison to a predetermined reference pressure value, can result from a pressure loss. It can also result from a tire change if the newly fitted tire is not properly inflated. The specified reference pressure value can either be a tire pressure value specified for the respective vehicle type and stored in a storage means arranged in the vehicle, or this reference pressure value is determined from the tire pressure values of the remaining tires of the vehicle, for example by averaging, provided that these tire pressure values are only a predetermined small one Value differ from each other. Said storage means can be part of the diagnostic device 10 or 25, for example. The above-mentioned remaining tires are to be understood as the tires of the vehicle which have neither a pressure loss nor a tire pressure value which is too low in comparison with a predetermined reference pressure value.

Claims

DaimlerChrysler AG patent claims

1. A method for protecting a tire of a wheel of a vehicle (1, 20), in which the vehicle wheel (2-5, 21-24) with the tire to be protected is relieved in the presence of a predetermined situation or condition, characterized in that the Tire pressure for at least one tire of the vehicle (1, 20) is recorded and monitored, and if the pressure loss in a tire is detected or if the tire pressure value in a tire is too low compared to a reference pressure value, the corresponding vehicle wheel (2-5, 21-24) is relieved.

2. The method according to claim 1, characterized in that a wheel load is shifted to that vehicle diagonal (29, 30) which does not include the tire with pressure loss or the tire pressure value which is too low.

3. The method according to any one of the preceding claims, characterized in that the damping behavior, in particular the damping characteristic of the vehicle (1.20) is changed on at least one wheel (2-5, 21-24).

4. The method according to claim 3, characterized in that at least on the shock absorber (6-9), which is assigned to the vehicle wheel to be relieved, in comparison to the setting of the shock absorbers assigned to the remaining wheels, the compression stage is set softer and the rebound stage is set harder.

5. The method according to claim 4, characterized in that on the shock absorber (6-9) of the wheel to be relieved diagonally opposite wheel (2-5) is also the compression level softer and the rebound is set harder

6. The method according to any one of claims 4 or 5, characterized in that the rebound and compression stages are set harder on the shock absorbers (6-9) of the remaining wheels (2-5).

7. The method according to any one of the preceding claims, characterized in that the relief of the at least one wheel (21-24) by means of a level control device and / or an air suspension system and / or a transverse stabilizer.

8. The method according to any one of the preceding claims, characterized in that the tire pressure of the defect-free tires is increased.

9. The method according to any one of the preceding claims, characterized in that the driver is given a signal regarding the load shift.

10. System for protecting a tire of a wheel of a vehicle (1, 20), in which the vehicle wheel (2-5, 21-24) with the tire to be protected is relieved in the presence of a predetermined situation or condition, characterized in that a Tire pressure sensor system (11, 26) for detecting the tire pressure for at least one tire and a diagnostic device (10, 25) for evaluating the detected tire pressures is provided, which is connected to a control unit (12, 27) which is a load shifting device (28 ) controlled in such a way that when a pressure loss is detected in a tire or when the tire pressure in a tire is too low in comparison to a reference pressure value, the corresponding vehicle wheel (2-5, 21-24) is relieved.

11. System according to claim 10, characterized in that the load shifting device comprises an air suspension system.

12. System according to claim 10 or 11, characterized in that the load shifting device comprises a level control device.

13. System according to one of claims 10 to 12, characterized in that the load shifting device (28) comprises at least one transverse stabilizer.

14. System according to one of claims 10 to 13, characterized in that that the load shifting device (28) has a device for influencing the tire pressure.

15. System according to one of claims 10 to 14, characterized in that the control device (12, 27) is designed as a chassis control device and / or shock absorber control device.

16. System according to one of claims 10 to 15, characterized in that a display device is provided with which the driver is given a signal relating to the load shift.