FR3071794B1 - WIPER BLADE - Google Patents

Abstract

The present invention relates to a wear sensor (11) intended to be positioned on a wiper device (5) in particular of a motor vehicle (1), the wiper device (5) comprising a wiper blade (9a). subjected to wear in which the wear sensor (11) comprises a humidity sensor (13) to take into account the climatic conditions to which the wiper blade (9a) is exposed.

Description

WIPER BLADE

The present invention relates to wiper blades used in wiping devices of motor vehicles.

These wiper blades are generally made of synthetic or natural rubber and are subject to wear over time. This wear depends on the time of use but also strongly on the conditions of use. In addition, the wiper blades are also sensitive to environmental conditions even outside their activation range.

These factors make it difficult to determine the wear of a wiper blade. However, visibility in bad weather being an essential safety parameter for the user, it is advisable to provide a solution making it possible to alert the user of the need to change his wiper blades.

It is known in the prior art to use a torque sensor at the level of the wiper drive motor to determine the torque generated by the motor and to deduce therefrom the coefficient of friction of the blade and therefore its wear in comparing the coefficient of friction with that of a new broom.

However, such a solution requires the use of electronic motors and on the other hand to have access to the computer program of the intelligent service box (BSI) which differ according to the manufacturers which makes a universal solution difficult.

The present invention therefore aims to propose a solution for determining reliably the wear of a wiper blade. To this end, the present invention relates to a wear sensor intended to be positioned on a wiping device in particular of a motor vehicle, the wiping device comprising a wiping blade subjected to wear in which the wear has a humidity sensor to take into account the climatic conditions to which the wiper blade is exposed.

According to another aspect of the present invention, the humidity sensor is a porous silicon sensor.

According to another aspect of the present invention, the wear sensor also comprises an accelerometer device comprising at least one accelerometer and is configured to determine a number of cycles of use from the measurements of the, at least one, accelerometer.

According to another aspect of the present invention, the wear sensor is configured to determine environmental conditions from measurements of the accelerometer device.

According to another aspect of the present invention, the wear sensor comprises a temperature sensor.

According to another aspect of the present invention, the wear sensor comprises wireless communication means.

According to another aspect of the present invention, the wireless communication means comprise a radio frequency antenna.

According to another aspect of the present invention, the wear sensor comprises a clock.

According to another aspect of the present invention, the wear sensor comprises a light detector.

According to another aspect of the present invention, the wear sensor comprises energy recovery means and is energy independent.

According to another aspect of the present invention, the energy recovery means are configured to recover the kinetic energy during the use of the wiper or the energy resulting from any vibration generated by the use of the vehicle.

According to another aspect of the present invention, the energy recovery means comprise photovoltaic cells.

According to another aspect of the present invention, the wear sensor comprises at least one capacitor configured to store the energy recovered by the energy recovery means.

According to another aspect of the present invention, the wear sensor comprises a positioning beacon (also called “geolocation”), for example of the “GPS” or “Galileo” type.

According to another aspect of the present invention, the wear sensor is covered with a semi-rigid gelatinous coating and comprises a fixing system allowing the positioning of the sensor on its support.

The present invention also relates to a wiper blade comprising a wiper blade subjected to wear and a wear sensor as described above. Other characteristics and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the appended drawings in which: FIG. 1 represents a schematic front view of a motor vehicle fitted with '' a wiper device,

2 shows a diagram of an assembly comprising an arm and a blade of a wiper device according to the present invention, FIG. 3 represents a diagram of a wear sensor according to the present invention, FIG. 4 represents a table of temperature intervals and the associated weighting coefficients used in the algorithm for determining the wear of the brush, FIG. 5 represents a diagram of a communication between a wear sensor and a mobile telephone according to the present invention.

In all the figures, identical elements have the same reference numbers.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the characteristics apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments.

The present invention relates to a wear sensor and a wiper blade for a motor vehicle. FIG. 1 represents the front part of a motor vehicle 1 comprising a windshield 3 and a wiping device 5 comprising two wiping arms 7 each provided with a wiping brush 9. It should be noted that the present invention can also be achieved at a rear wiper device of a motor vehicle.

FIG. 2 represents an assembly comprising a wiping arm 7 and a wiping brush 9. The assembly is configured so that the wiping brush 7 can be easily removed from the wiping arm 9, for example by snap-fastening between the wiper arm 7 and the wiper blade 9. The wiper blade 9 comprises a wiper blade 9a intended to come into contact with the windshield 3 when the wiper blade 9 is mounted on the motor vehicle 1. The wiper blade 9 can therefore be easily replaced when the wear of the wiper blade 9a requires it.

In addition, the wiper blade 9 is equipped with a wear sensor 11 configured to determine the wear of the wiper blade 9a. Alternatively, the wear sensor 11 can be offset from the wiping brush 9 and positioned for example on the wiping arm 7 or on any other element located near the wiping brush 9. The wear sensor can comprise a fixing means for fixing it on its support (positioned on the wiper blade 9 or on the wiper arm 7 for example). The fixing is for example carried out by snapping or crimping or molding.

As shown in FIG. 3, the wear sensor 11 comprises a humidity sensor 13 which makes it possible to determine the climatic conditions to which the wiping blade 9a is exposed. The humidity sensor 13 is for example produced by a porous silicon sensor whose impedance varies as a function of the humidity level in the porous silicon.

The wear sensor 11 may also include an accelerometer device 15 comprising at least one accelerometer for detecting a movement of the wiper blade 9. If only one accelerometer is used, its orientation is adjusted to detect a movement perpendicular to the axis of the wiper blade 9 which corresponds to the direction of movement of the wiper blade 9. It is also possible to use a multi-axis accelerometer, in particular a three-axis accelerometer or several accelerometers, for example three accelerometers arranged in a trihedral to be able to detect all the movements of the wiper blade 9. In addition, the use of one or more accelerometers can make it possible to detect variations in environmental conditions. In fact, in the event of frost or high heat, the wiping blade 9 can adhere more strongly to the windshield when the wiping device 5 is activated so that the acceleration will be greater when the brush d wiping will be set in motion. However, these environmental conditions having a strong influence on the wear of the wiping blade, it is possible to adjust the determination of the wear of the wiping blade by determining these variations in environmental conditions.

The wear sensor 11 may also include a temperature sensor 17, for example a thermocouple or a thermistor which makes it possible to determine the periods of frost or high heat.

The wear sensor 11 can also include a brightness sensor 19, for example a photodiode. Indeed, some wiping blades 9a are sensitive to ultraviolet (UV) rays, in particular the wiping blades 9a made of natural rubber so that a brightness sensor 19 makes it possible to estimate the amount of UV to which is exposed the wiping blade 9a.

The wear sensor 11 also includes a processing unit 21 connected to the various measurement means of the wear sensor 11 described above. The processing unit 21 is for example produced by a microcontroller or a microprocessor and can comprise an internal clock 25. The processing unit 21 is configured to determine a level of wear of the wiping blade 9a from the measurements of the different sensors of the wear sensor 11. The measurements of the different sensors can be combined according to a predefined algorithm taking into account the different measurements. For example, different weighting coefficients of wear can be defined according to the measurement intervals of the different sensors and these weighting coefficients are combined to define a function defining the wear of the blade as a function of time, the different coefficients weighting modifying the slope of the function.

For example, with regard to temperatures, different intervals can be defined as shown in the table in FIG. 4. For example a first interval II for temperatures below -20 ° C associated with a first weighting coefficient PI, a second interval 12 for temperatures between -20 ° C and 0 ° C associated with a second weighting coefficient P2, a third interval 13 for temperatures between 0 ° C and 30 ° C associated with a third weighting coefficient P3 and a fourth interval for temperatures above 30 ° C associated with a fourth weighting coefficient P4. In this example, the weighting coefficient PI will for example be very high to take account of rapid wear of the wiping blade 9a when the temperatures are below -20 ° C. while the weighting coefficient P3 will be low because between 0 and 30 ° C the wear of the blade 9a is reduced. The number of intervals and the value of the limits of the intervals are given by way of example and other values can be used without departing from the scope of the invention.

Likewise, different weights can be applied for humidity and other parameters. These parameters can then be combined, for example by a sum or a multiplication or another mathematical function in the algorithm in order to obtain a wear coefficient and apply it for the corresponding duration of use. Thus, by taking into account the measurements of the sensors associated with the various parameters of influence of wear of the wiping blade 9a, it is possible to reliably determine the level of wear of a wiping blade 9a at over time.

The wear sensor 11 can also include wireless communication means 23 (shown in FIG. 3), for example a radio frequency antenna allowing for example a Wifi ™ or Bluetooth® type communication with a mobile phone 24 (visible in FIG. 5) or an on-board computer of the motor vehicle. By mobile phone is meant here in particular a smart phone or “smartphone” in English or any other portable electronic device allowing wireless communication such as a tablet or a laptop. A dedicated application is for example installed on the mobile phone and is configured to communicate regularly with the wear sensor and recover the level of wear determined by the wear sensor 9. Other parameters can also be retrieved via communication with the wear sensor 9.

The wear sensor 11 can also function as a label, also called a tag in English, configured to interact with a remote reader, located for example at the on-board computer of the motor vehicle. In this case, the reader sends a signal to the label which communicates with the reader by modulating and returning the signal transmitted by the reader, the data being transmitted by the modulation of the received signal. The label can also use the signal transmitted by the reader as a source of energy. The label can include two operating states, a standby state to save energy and an active state when electromagnetic signals are received at the antenna and supply energy. The electromagnetic signals received thus correspond to an activation signal.

Thus, a communication at predefined time intervals, for example each month, can be established between the mobile telephone (or the on-board computer) and the wear sensor as shown in FIG. 5. This communication makes it possible to transmit the estimate of the wear of the wiper blade 9a carried out by the wear sensor 11 on the mobile telephone (or on-board computer), the latter being able to send a signal to the user to inform him of the level d wear of the wiping blade, in particular when the level of wear reaches a predetermined threshold, for example 95% of the theoretical life of the wiping blade 9a. The signal can correspond to an audible signal, a visual signal or a vibration. The signals can be different depending on the percentage of wear, for example a green visual signal when the wear percentage is less than 80%, an orange visual signal when the wear percentage is between 80 and 95% and a red visual signal combined with an audible signal when the percentage of wear exceeds 95%.

According to a particular embodiment, the wear sensor 11 is autonomous in energy and includes energy recovery means such as for example a photovoltaic panel, a mechanical pendulum making it possible to recover part of the kinetic energy supplied by the displacement wiper blade when activating the wiping device or vibrations generated in the motor vehicle, a piezoelectric device, a radio frequency antenna configured to recover energy from the surrounding radio frequency waves or a combination of the above devices or any other energy recovery device known from the state of the art. These energy recovery means can be associated with a high capacity capacitor configured to store part of the recovered energy and return it later.

The wear sensor 11 can also include a positioning beacon or GPS beacon 27 making it possible to locate the wiper blade 9. Indeed, depending on the location of the vehicle, certain environmental parameters of influence of the wear of the wiper blade. wiping 9 can be determined and taken into account by the processing unit 21 to determine the level of wear of the wiping brush 9. These environmental parameters correspond for example to air pollution or to the presence of sand or other abrasive particles for example.

In addition, the wiper blade being able to communicate with a mobile phone (or an on-board computer) as described above, it is also possible to transmit information concerning parameters of influence of the wear of the brush via said communication. . For example, in the absence of a GPS beacon 27, the position can be provided to the wiping broom by the mobile telephone (or the on-board computer) in order to allow the processing unit 21 to take into account this setting. Conversely, the parameters measured by the wear sensor 11 can be transmitted to the mobile telephone (or to the on-board computer). Thus, the temperature measured by the wear sensor 11 can be used to determine an outside temperature or the humidity sensor can be used to automatically trigger the wiping device.

The wear sensor 11 can be covered with a protective coating, for example a semi-rigid gelatinous coating to avoid any degradation of the components of the wear sensor 11. A fixing device then allows fixing on its support, for example fixing by snap-fastening, by screwing or by crimping.

An example of the operation of a wiper blade 9 provided with a wear sensor 11 will now be described. The wear sensor 11 is fixed to the wiper blade 9 which can be a wiper blade installed on a new vehicle or a spare part installed to replace a worn wiper blade 9. The processing unit 21 of the wear sensor 11 is synchronized with the portable telephone 24 (or the on-board computer). Synchronization or zeroing is performed each time the wiper blade 9 is changed, either to establish the connection between the new wear sensor 11 and the mobile telephone 24 (or the on-board computer), or to reset the level of wear when changing the wiper blade 9.

The wear sensor 11 is therefore configured to determine the wear of the blade 9a of the wiper blade 9 over time and to weight this wear as a function of the signals received from the various sensors of the wear sensor 11 as the variations temperature, duration of use of the wiping system, humidity, etc. The processing unit 21 is for example configured to retrieve a measurement of the various components of the wear sensor 11 at regular time intervals. The time intervals can be fixed or dependent on the value of other parameters, for example in case of high humidity, the time interval between two acceleration measurements may be reduced. The processing unit 21 therefore combines, at regular time intervals, all of the measurements to determine the level of wear of the wiping blade 9a. The time interval between each measurement or each determination of wear can also depend on the level of energy available.

The mobile telephone 24 (when it is near the vehicle, that is to say within the scope of the communication protocol used between the telephone 24 and the wear sensor 11) or the on-board computer are for example configured to detect the wear sensor 11 and send it a request to estimate the wear of the blade 9a of the wiper blade 9 at regular time intervals, for example each month.

The wear sensor 11 receives the signal sent by the mobile telephone 24 (or the on-board computer) corresponding to a request to send the wear level. The wear sensor 11 then sends the last wear value of the blade 9a determined to the telephone 24 (or to the on-board computer) and the latter updates the stored wear value. The user can then see the level of wear of his or her fitting brushes 9 by consulting his mobile phone (or the on-board computer), for example via a dedicated menu. When the wear level reaches 95%, an indicator and / or an alarm can be activated to warn the user of the need to change the wiper blade 9.

Thus, the use of a wiper blade 9 comprising a wear sensor 11 comprising means for measuring the parameters of influence of the wear of the blade 9a of the wiper blade 9 makes it possible to determine reliably the wear of the wiping blade 9a and therefore the moment of the change of wiper blade 9. In fact, effective wiping increases visibility and therefore safety in bad weather. In addition, the change of wiper blade 9 being a simple action, it is often carried out by the user himself so that the wear sensor 11 makes it possible to inform the user of the opportune moment to make the change. wiper blades and thus maintain optimal wiping efficiency while avoiding changing unused wiper blades.

Claims (16)

1. Wear sensor (11) intended to be positioned on a wiping device (5) in particular of a motor vehicle (1), the wiping device (5) comprising a wiping blade (9a) subjected to t wear characterized in that the wear sensor (11) comprises a humidity sensor (13) to take account of the climatic conditions to which the wiping blade (9a) is exposed. 2. Wear sensor (11) according to claim 1 wherein the humidity sensor (13) is a porous silicon sensor. 3. Wear sensor (11) according to claim 1 or 2 also comprising an accelerometer device (15) comprising at least one accelerometer and configured to determine a number of cycles of use from the measurements of the, at least one, accelerometer . 4. Wear sensor (11) according to claim 3 wherein the wear sensor (11) is configured to determine environmental conditions from the measurements of the accelerometer device (15). 5. Wear sensor (11) according to one of the preceding claims comprising a temperature sensor (17). 6. Wear sensor (11) according to one of the preceding claims comprising wireless communication means (23). 7. wear sensor (11) according to claim 6 wherein the wireless communication means (23) comprise a radio frequency antenna. 8. Wear sensor (11) according to one of the preceding claims comprising a clock (25). 9. Wear sensor (11) according to one of the preceding claims comprising a light detector (19). 10. Wear sensor (11) according to one of the preceding claims comprising means for recovering energy, said wear sensor (11) being energy independent. 11. Wear sensor (11) according to claim 10 wherein the energy recovery means are configured to recover kinetic energy when using the wiper. 12. Wear sensor (11) according to claim 10 wherein the energy recovery means comprise photovoltaic cells. 13. Wear sensor (11) according to one of claims 10 to 12 comprising at least one capacitor configured to store the energy recovered by the energy recovery means. 14. Wear sensor (11) according to one of the preceding claims comprising a positioning beacon, for example of the “GPS” or “Galileo” type (27). 15. Wear sensor (11) according to one of the preceding claims wherein the wear sensor (11) is covered with a semi-rigid gelatinous coating. 16. Wiper blade (9) comprising a wiper blade (9a) subjected to wear and a wear sensor according to one of the preceding claims.