WO2024008308A1

WO2024008308A1 - Measuring device for a friction brake device, friction brake device, vehicle, in particular utility vehicle, and method for calibrating a measuring device

Info

Publication number: WO2024008308A1
Application number: PCT/EP2022/069079
Authority: WO
Inventors: Artem Grig
Original assignee: Zf Cv Systems Europe Bv
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2024-01-11

Abstract

One aspect of the invention relates to a measuring device (100) for a friction brake device (200) for a vehicle (300a), in particular a utility vehicle (300b), comprising a dust collecting device (110) for collecting dust particles (210) of two friction partners (220, 230, 240) of the friction brake device (200), wherein the friction partners (220, 230, 240) are designed to produce a braking effect by being rubbed together, and comprising a dust measuring assembly (120) for assessing the quantity (215) of dust particles (210) collected in the dust collecting device (110). Another aspect of the invention relates to a method (400) for calibrating the measuring device (100).

Description

Measuring device for a friction brake device, friction brake device, vehicle, in particular commercial vehicle, method for calibrating a measuring device

The invention relates to a measuring device for a friction brake device for a vehicle, in particular a commercial vehicle. The invention also relates to a friction brake device for a vehicle, in particular a commercial vehicle, a vehicle, in particular a commercial vehicle, and a method for calibrating a measuring device.

The disclosure relates primarily to the area of disc brakes in the commercial vehicle sector, but also in the passenger car sector and in the rail vehicle sector. Basically, all applications are conceivable in which a friction brake or friction brake device is used and in which at least two bodies touch each other when braking with the friction brake device. The bodies of the friction brake device that come into contact during braking are also called friction partners. Two such bodies are, for example, a brake pad and a brake disc in a disc brake. Braking or a braking effect causes abrasion of the friction partners and the associated wear of the friction partners. The abrasion can occur as so-called brake dust.

According to the state of the art, the wear of the friction partners is sensed continuously using a so-called continuous wear sensor (CWS). It is known that a CWS includes an analog measuring device, which indirectly draws conclusions about a measured variable to be determined. It is also known that a CWS can have direct or indirect contact with a friction partner or an adjacent component such as an adjuster spindle or a brake piston itself. The contact is ongoing, that is, continuously, in order to be able to continuously determine the wear of the friction partner. When sensing wear, components that typically move away from one another as the brake partners become more worn are typically relevant - i.e., their position relative to one another constantly changes as the brake wears. In the case of disc brakes, a reference point for sensing is typically arranged on a brake caliper; and relative to the reference point, a position sensor detects the position of the brake piston. This constantly increasing or decreasing distance between the friction partners is the measurement variable that conventional and continuously measuring wear sensors record in order to ultimately be able to draw sufficiently accurately the prevailing strength of the friction partners, for example the remaining pad and brake disc thickness. It is also known that the continuous wear sensors can often record the entire brake wear, that is, in the case of a disc brake, the wear of two brake pads as well as the wear on both sides of the brake disc.

WO 2017/063726 A1 discloses a disc brake, in particular for a commercial vehicle. The disc brake has a wear sensor and an adjusting device, which has an adjusting element in the form of a pressure screw and / or a pressure sleeve, the adjusting element having a recess into which a resetting device rotatably coupled to the adjusting element protrudes to reset the adjusting device, and the wear sensor at least partially lies in the recess.

Alternatively or additionally, wear can be determined by using pad wear warning indicators (PWWI). Pad wear indicators are arranged directly on the brake pads and have one or more loop-through contacts, each of which only indicates a single condition such as. B. can indicate a “90% warning limit”. In this respect, it is not possible to speak of a continuous wear measurement that provides output values that can be further processed by a control unit, for example for wear harmonization that is established in practice.

Furthermore, it is known that brake dust particles caused by abrasion are not simply released into the environment, but through so-called Brake dust particle filters are bound in a chamber. Binding or collecting brake dust particles may be desirable and/or required by law and therefore necessary.

DE 10 2012 016 835 A1 discloses a brake dust collection device for motor vehicles. It is proposed to collect and dispose of the brake abrasion that occurs between the brake pad and the brake disc on a disc brake. The particles emerging between the pad and the disc are transported into the molded filter in conjunction with the air flow caused by the disc and stored there. The brake dust collection device comprises a filter element and a filter element receptacle, wherein the filter element is designed as a molded filter and the molded filter has at least two partial areas that have different porosities.

The object of the present invention report is to enrich the prior art and improve the above-mentioned aspects. In particular, it may be an object of the invention to provide an improvement in an estimate of the brake wear of a brake, whereby wear can be quantitatively and qualitatively assigned to a state of wear.

The task is solved by the subject matter of claim 1. The task is also solved by the subjects of the further independent and/or subordinate claims.

According to one aspect of the invention, a measuring device for a friction brake device for a vehicle, in particular a commercial vehicle, is provided. The measuring device comprises a dust collecting device for collecting dust particles from two friction partners of the friction brake device, the friction partners being set up to generate a braking effect through friction with one another, and a dust measuring arrangement for estimating a quantity of dust particles collected in the dust collecting device.

It was recognized that the wear of the friction partners can be determined based on the amount or accumulation of dust particles generated. At the When braking, i.e. when the friction brake device is actuated, particles of the friction partners are released from the friction partners in the form of dust particles and collected in the dust collecting device. This binds the dust particles and/or no or less dust is released into the vehicle's environment.

The dust measuring arrangement is set up to estimate the amount of dust particles collected, i.e. to track a continuous measurement of the amount of dust particles collected. By optionally using additional information, such as known geometries of the friction partners and wear conditions, a representative amount of wear, for example a percentage of wear in %, can be assigned to the amount and the condition of the friction brake device can therefore also be specified qualitatively. Further information can be derived from wear. For a disc brake, a residual lining thickness, for example in mm, and a brake disc thickness, for example in mm, can be derived. The information and/or knowledge about the remaining pad and brake disc thickness is optional, since the amount of dust particles determined alone indirectly includes all the information necessary to determine brake wear.

This makes it possible to provide information about wear depending on the use of the friction partners. A measurement to determine in particular the total wear of the friction partners is effectively possible.

Existing components of a friction brake device can be used for the measuring device in order to enable continuous wear measurement. This makes continuous wear measurement cost-effective and reliable. By sensing brake wear on a brake with such a dust collecting device, the abrasion can be assigned to a state of wear both quantitatively and qualitatively. An existing and in particular encapsulated friction brake device can be upgraded relatively easily and effectively with the measuring device.

The dust measuring arrangement is preferably set up to determine a mass of the amount of dust particles. To effectively address the resulting wear To be able to conclude, the actual abrasion can be quantified by determining the brake dust particle mass, for example in kg or a unit that can be converted into kg. Alternatively or additionally, the dust measuring arrangement is set up to determine a volume of the amount of dust particles. In order to be able to draw effective conclusions about the resulting wear, the brake dust particle volume can be determined, for example in cm ³ or a unit that can be converted into cm ³ . Alternatively, the number of dust particles can be determined in order to be able to draw conclusions about the amount and thus the wear of the friction partners. The mass, volume and number of dust particles are continuously measurable quantities that can be recorded at any time and can provide precise information about the closure of the friction partners.

Preferably, the measuring device is set up to determine a mass of the dust collection device including the amount of dust particles. In other words, the measuring device is set up to determine the sum of the masses of the dust collection device and the mass of the amount of dust particles. The mass of the dust collection device together with the dust particles can be determined effectively. It was recognized that the mass of the dust collection device, including the amount of dust particles, increases with increasing wear. The mass of the dust collection device including the amount of dust particles can be determined absolutely, i.e. as the sum of the masses of the dust collection device and the mass of the amount of dust particles. Alternatively, it is possible for the mass of the dust collection device, including the amount of dust particles, to be determined relative to the mass of the dust collection device. This means that an increment in the mass of the amount of dust particles caused by abrasion is determined.

The measuring device preferably has a deflection section that can be deflected relative to the vehicle, in particular a commercial vehicle, wherein the deflection section can be deflected depending on a mass of the dust collecting device including the amount of dust particles. The mass of the amount of dust particles and a force associated therewith, in particular a weight force and/or an inertial force, can result in a deflection of the deflection section. The deflection can be proportional to the Be the mass of the amount of dust particles, with which a measurement of the deflection allows information about the mass of the dust particles collected in the dust collection device. The deflection section can be an integral part of the dust collection device. In other words, the dust collecting device and the deflection section are, for example, designed in one piece and/or comprise a common, one-piece housing. Alternatively, the deflection section can be set up, for example, to suspend a measuring container arranged in the dust collecting device, the measuring container being set up to collect and weigh dust particles.

Preferably, the dust collecting device has a mounting section fixed to the vehicle and a deformable decoupling section arranged between the mounting section and the deflection section for deflecting the deflection section, and the mass of the dust collecting device including the amount of dust particles can be determined based on a deformation of the decoupling section. In this embodiment, the decoupling section is set up to enable deflection of the deflection section. Analogous to the deflection section, the decoupling section can be an integral part of the dust collection device. The deflection can be measurable by means of a strain gauge arranged at the decoupling point in order to be able to assign the deflection to the mass reliably, precisely and effectively.

The measuring arrangement preferably has an acceleration sensor and a force sensor for measuring a force acting on the dust collecting device. The acceleration sensor, the force sensor and a known mass of the dust collection device make it possible to effectively determine the mass of the dust collection device using Newton's laws. It is assumed that the dust collection device, including the amount of dust particles, accelerates under the influence of the force that can be determined by the force sensor with an acceleration that can be determined by the acceleration sensor, whereby the total mass of the dust collection device, including the amount of dust particles, can thus be concluded. If the mass of the dust collection device is known, the mass of the amount of dust particles can be determined getting closed. This makes it possible to achieve an effective and continuous determination of the mass.

Preferably, the measuring device is set up to measure the fill level of the dust collection device. For this purpose, the measuring device can include a fill level sensor. Level measurement is effective for estimating the volume of dust particles in particular. When measuring the level, for example, a level of a dust collection device comprising a filter can be recorded.

The dust measuring arrangement is preferably set up for mechanical, electromechanical, resistive, capacitive and/or optical estimation of the amount of dust particles. Mechanical estimation can be particularly cost-effective, for example by controlling the quantity using a scale and/or a float. The deflection of the scale and/or the float can be detected in order to detect the mass and/or a volume of the amount of dust particles. Electromechanical taxiing can be particularly cost-effective and reliable. For example, the mass can be detected via a strain gauge, with the strain gauge changing its electrical properties depending on its deformation. Resistive estimation can effectively provide information about the amount of dust particles by determining an electrical resistance and/or a conductivity of the amount of dust particles. Capacitive and/or optical estimation can be used in particular to determine the volume of the amount of dust particles. The measurement methods mentioned make it possible to continuously and effectively estimate the amount of dust particles. Optionally, one or more of the measurement methods mentioned can be used to estimate the amount of dust particles. For example, a combination of several of the measurement methods can be used in order to be able to carry out a plausibility check and/or to improve the accuracy of the estimation.

Preferably, the dust collection device is evacuated from an environment of the vehicle, in particular a commercial vehicle. This makes it possible to provide a low-emission and/or emission-free friction brake device. That's it In particular, an encapsulation of an axially actuated disc brake is possible. The evacuation of the dust collection device makes it possible to estimate the amount of dust particles particularly effectively and reliably, as it can be ensured that no dust particles enter the environment in an uncontrolled manner. This allows an estimate of the wear of the friction partners to be further improved.

Preferably, the measuring device comprises a data processing device and/or can be connected to a data processing device, wherein the data processing device is set up to receive quantity information relating to the amount of dust particles, and wherein the data processing device is set up to carry out a determination of wear of the friction partners depending on the quantity information. The use of a known data processing device or a known control device in vehicles is possible because the measuring device enables continuous measurement and testing of the brake condition, and the input variables relevant to the control devices can also optionally be retained.

According to one aspect of the invention, a friction brake device is provided. The friction brake device includes a measuring device described here. Optionally, the measuring device has a feature described as optional and/or advantageous in order to achieve an associated technical effect.

According to one aspect of the invention, a vehicle, in particular a commercial vehicle, is provided. The vehicle, in particular a commercial vehicle, comprises a measuring device described here and/or a friction brake device described here, comprising the measuring device described here. Optionally, the measuring device has a feature described as optional and/or advantageous in order to achieve an associated technical effect.

According to one aspect of the invention, a method for calibrating a measuring device described here is provided. The method includes the steps of: estimating the amount of dust particles collected in the dust collection device; empirical determination of the wear of the friction partners; and deriving a connection between the amount of dust particles and the closure of the friction partners.

Calibrating the measuring device describes deriving or determining the relationship between the amount of dust particles and the closure of the friction partners as effectively and accurately as possible.

For this purpose, the amount of dust particles collected is estimated or determined as described above with reference to the measuring device. The closure of the friction partners is determined empirically, for example through a measurement. The empirical determination of the closure is carried out, for example, by a test bench test and/or a field test, whereby the friction partners are worn by braking. By closing the friction partners, dust particles accumulate and the wear of the friction partners is determined, for example, based on the wear of the friction partners. When evaluating the amount of brake dust particles, as much information and parameters as possible are recorded in order to obtain the most accurate and meaningful database possible regarding wear and abrasion. A characteristic curve can therefore be derived and used to characterize the relationship between the amount of dust particles and the closure of the friction partners. The characteristic curve can be used analogously to characteristic curves when using CWS to indicate wear and, for example, to trigger warning and/or error messages in the event of high wear.

The method preferably has the step: plausibility of the estimated amount of dust particles based on the empirically determined wear. To check plausibility, the abrasion can be theoretically predicted taking into account material properties and/or the geometry of the friction partners. Using the empirically obtained database, the theoretically determined values can then be checked or checked for plausibility. From this, for example, the degree of insulation or evacuation of the dust collection device can be quantified and/or parameters and correction factors for the Determination of wear or the relationship between the amount of dust particles and the closure of the friction partners for the derivation.

Further advantages and features of the invention as well as their technical effects result from the figures and the description of the preferred embodiments shown in the figures. Show it

1 shows a schematic representation of a vehicle, in particular a commercial vehicle, according to an embodiment of the invention;

2 shows a schematic representation of a measuring device according to an embodiment of the invention;

3 shows a schematic representation of a measuring device according to a further embodiment of the invention;

4 shows a schematic representation of a measuring device according to a further embodiment of the invention; and

Fig. 5 is a schematic representation of a flowchart of a method according to an embodiment of the invention.

Figure 1 shows a schematic representation of a vehicle 300a, in particular commercial vehicle 300b, according to an embodiment of the invention. The vehicle 300a, in particular commercial vehicle 300b, is referred to below as vehicle 300a, 300b.

The vehicle 300a, 300b has a friction brake device 200. The friction brake device 200 is a disc brake device and has three friction partners 220, 230, 240. For example, one of the friction partners 230 is a brake disc, another of the friction partners 220 is a reaction-side brake pad and is arranged on a side of the brake disc facing away from the vehicle 300a, 300b, and another of the friction partners 240 is a brake pad on the application side and on a side of the vehicle 300a, 300b arranged on the side facing the brake disc. The brake disc is therefore the friction partner 230, which is arranged between the two other friction partners 220, 240. By actuating the friction brake device 200, the friction partners 220, 230, 240 come into contact with one another. The contact between the friction partners 220, 230, 240 leads to friction between the friction partners 220, 230, 240 and thus to a braking effect as well as to wear of the friction partners 220, 230, 240 and an accumulation of dust particles 210 (not shown in Figure 1), which come out of the friction partners 220, 230, 240 or replace.

In another embodiment, not shown, the friction brake device 200 can be a different type of brake, for example a drum brake and/or a wedge brake, and/or have a different number of friction partners.

The vehicle 300a, 300b or the friction brake device 200 comprises a measuring device 100.

The measuring device 100 includes a dust collecting device 110 and a dust measuring arrangement 120.

The dust collection device 110 is set up to collect dust particles 210 from the friction partners 220, 230, 240 of the friction brake device 200. The dust collection device 110 is evacuated from an environment 310 of the vehicle 300a, 300b. That is, the dust collection device 110 is set up to collect and/or bind the dust particles 210 released from the friction partners 220, 230, 240. For this purpose, the dust collecting device 110 can have a sealing element, not shown in FIG. The proposed measuring device 100 for determining pad wear is more reliable and accurate if the measuring device 100 is subject to encapsulation from the environment so that all brake dust particles 210 can be taken into account for an accurate measurement. At the same time, the evacuation prevents foreign substances such as water from getting into the collecting container 110 and thus falsifying a measurement result.

The dust measuring arrangement 120 is set up to estimate a quantity 215 of dust particles 210 collected in the dust collection device 110. Embodiments of the measuring device 100 and in particular the dust measuring arrangement 120 are described with reference to FIGS. 2 to 4. As shown in Figure 1, the vehicle 300a, 300b has a data processing device 150. The measuring device 100 is connected to the data processing device 150, the data processing device 150 being set up to receive quantity information 151 relating to the quantity 215 of the dust particles 210 from the measuring device 100. The measuring device 100 can sensorically determine a voltage corresponding to the quantity information 151 from a quantity such as a distance in mm or a mass in kg and output a voltage value to the data processing device 150 as quantity information 151. A state of wear can be assigned to the voltage value by the data processing device 150. The quantity information 151 can thus be interpreted as a function of the mass or volume or the number of dust particles 210 with an indirect information content about the state of wear of the friction partners 220, 230, 240. The state of wear can then always be quantified indirectly via the tension and prior determination of the relationship between the quantity 215 of the accumulation particles 210 and the closure of the friction partners 220, 230, 240; for example. 1 V = 0% wear condition, 3V = 100% wear condition, values in between follow a linear progression, for example.

The data processing device 150 can be, for example, an electronic control unit (ECU) of the vehicle 300a, 300b. In another embodiment, not shown, the measuring device 100 can include the data processing device 150 and can be connected to a vehicle-side control unit, for example via a fieldbus or a CAN interface.

The data processing device 150 is set up to determine wear of the friction partners 220, 230, 240 depending on the quantity information 151. If a permissible abrasion and thus a permissible total wear defined by a relationship between the quantity 215 of the accumulation particles 210 and the wear of the friction partners 220, 230, 240 is exceeded, a warning message can be issued via the data processing device 150 using predetermined warning limits. The state of wear of the friction brake device 200 can be determined via the relationship between the quantity 215 the jam particles 210 and the closure of the friction partners 220, 230, 240 are output qualitatively and/or quantitatively, for example with 100% - 0%, and/or displayed in the vehicle 300a, 300b.

Figure 2 shows a schematic representation of a measuring device 100 according to an embodiment of the invention. The measuring device 100 is a measuring device 100 for a friction brake device 200 of a vehicle 300a, 300b as described with reference to FIG. 1. The measuring device 100 is shown schematically in FIG. 2 in a side view. A friction partner 220 designed as a brake pad and a friction partner 230 designed as a brake pad are indicated schematically with a dashed line. The further friction partner 240 is not shown.

When braking, dust particles 210 are released from the friction partners 220, 230, 240, as shown schematically and not to scale. Due to a weight force acting on the dust particles 210 and/or an air flow acting within the measuring device 200, the dust particles 210 are moved into the dust collecting device 110 as shown schematically by an arrow with a dashed line. The dust particles 210 form a schematically illustrated quantity 215 of the dust particles 210. The quantity 215 of the dust particles 210 has a mass M and a volume V. The quantity 215 of the dust particles 210 or its volume V defines a fill level 146 of the dust collecting device 110.

The dust measuring arrangement 120 is set up to determine the mass M of the quantity 215 of dust particles 210. For this purpose, the measuring device 200, more precisely the dust collecting device 110, has a deflection section 115 that can be deflected relative to the vehicle 300a, 300b.

The dust collection device 110 including the amount 115 of the dust particles 110 has a mass M '. The mass M' causes a force F acting on the deflection section 115, which is shown schematically with an arrow with a dashed line. The force F is, for example, the weight force acting on the mass M 'and thus the dust collecting device 110 and the quantity 115 of the dust particles 110. The deflection section 115 is dependent on a mass M ' the dust collection device 110 including the quantity 215 of dust particles 210 can be deflected.

The dust collecting device 110 has a mounting section fixed to the vehicle

116 and a deformable decoupling section arranged between the holding section 116 and the deflection section 115

117 for deflecting the deflection section 115. The decoupling section 117 is deformable. The deformation of the decoupling section 117 causes the deflection of the deflection section 115 and is dependent on the mass M 'of the dust collecting device 110 including the quantity 115 of the dust particles 110. The mass M' of the dust collecting device 110 including the quantity 115 is therefore based on the deformation of the decoupling section 117 Dust particles 110 can be determined.

For this purpose, a strain gauge (not shown) can be arranged on the decoupling section 117 in such a way that when the decoupling section 117 is deformed, the strain gauge undergoes a deformation that is dependent on it. The electrical and/or resistive properties of the strain gauge thus change depending on the deformation of the decoupling section 117. The electrical and/or resistive properties of the strain gauge are measurable, whereby the dust measuring arrangement 120 is set up for electromechanical and/or resistive control of the quantity 215 of the dust particles 210 is.

In other words, FIG. 2 describes a measuring device 100 for weighing. The mass determination of the mass M of the quantity 215 of the dust particles is possible continuously based on the contents located in the brake dust particle filter, i.e. the collecting container 110. The collecting container 110 is functionally and/or structurally separated from a wheel end (not shown) arranged on the mounting section 116 by the decoupling section 117 from the deflection section 115. The measurement of the mass M is advantageously carried out in a state that is as stationary as possible, for example. B. the vehicle 300a, 300b is at rest or when it is driving on a road that is as flat as possible in order to keep disruptive influences as low as possible. Figure 3 shows a schematic representation of a measuring device 100 according to a further embodiment of the invention. The measuring device 100 according to FIG. 3 is described with reference to FIGS. 1 and 2, with particular differences from the measuring device 100 according to FIG. 2 being described.

The dust measuring arrangement 120 according to FIG. 3 is set up to determine a mass M of the quantity 215 of dust particles 210. For this purpose, the dust collection container 110 in particular has the deflection section 115.

The measuring arrangement 100 has an acceleration sensor 130 and a force sensor 140 for measuring a force F acting on the dust collecting device 110. The force sensor 140 is arranged between the holding section 116 and the deflection section 150 in order to measure the force F acting on the collecting container 110, in particular the deflection section 115. The acceleration sensor 130 is arranged in the deflection section 115 and is set up to measure an acceleration a (not shown in FIG. 3) of the deflection section 115.

The measuring device 100 according to FIG. 3 implements an additional or alternative indirect measuring method to the measuring arrangement according to FIG. 2, which is based on Newton's law of inertia. The mass M is determined via the acting force F and the accelerations a using a force sensor 140 and the acceleration sensor 130. This makes it possible to calculate the mass M of the quantity 215 of the dust particles 210 in a dynamically moving system, which can be beneficial for practical use and continuous measurement.

The acceleration a represents the acceleration that can be recorded by the acceleration sensor 130. In an embodiment not shown, several acceleration sensors can be used to check the plausibility and/or improve the measurement of the acceleration a, for example one directly at the end of the wheel and one on the collecting container 110. Due to the arrangement of the acceleration sensor 130, the acceleration sensor 130 is largely decoupled from the vehicle 300a, 300b via a spring and/or damping element. When the collection container 110 experiences an acceleration a, for example when the vehicle 300a, 300b drives over a pothole, the acceleration sensor 130 and the collection container 110 experience the same acceleration a. This means that the acceleration a measured by the acceleration sensor 130 can be used to determine the acceleration of the collecting container 110 and in particular the acceleration of the quantity 215 of the dust particles 210.

The deflection section 115 is decoupled from the wheel end or the mounting section 116 by the decoupling section 117 in order to avoid that the weight of the entire wheel end flows into the dynamics of the deflection section 115.

The force F is the inertial force that results from the total mass M 'of the decoupled dust collection device 110 or the deflection section 115 including the quantity 115 of the dust particles 110 and the acceleration a, F = M' x a. The force F can be measured via the force sensor 140, which is introduced as a tension and/or pressure sensor into the optionally elastic connection point between the brake dust particle filter and the wheel end, i.e. is arranged on the decoupling section 117.

The measurement of the force F and the acceleration a by the force sensor 140 or the acceleration sensor 130 can in particular be carried out mechanically and/or electromechanically, with which the dust measuring arrangement 120 is set up for mechanically and/or electromechanically assessing the quantity 215 of the dust particles 210. Optionally, a frequency analysis can be taken into account in a dynamic measurement process.

The embodiment of the measuring device 100 according to FIG. 3 can be combined with the embodiment of the measuring device 100 according to FIG. 2 in order to improve an estimate of the quantity 215 of the dust particles 210. Figure 4 shows a schematic representation of a measuring device 100 according to a further embodiment of the invention. The measuring device 100 according to FIG. 4 is described with reference to FIGS. 1 to 3, with particular differences to the measuring devices 100 according to FIGS. 2 and 3 being described.

The dust measuring arrangement 120 is set up to determine a volume V of the quantity 215 of dust particles 210. For this purpose, the measuring device 110 has several fill level sensors 145. Each of the level sensors 145 is set up to measure a level 146 of the dust collection device 110. The fill level 146 is dependent on the volume V of the quantity 215 of dust particles 210 in the dust collecting device 110. In an embodiment not shown, the dust measuring arrangement 120 has a fill level sensor 145.

The measuring device 100 can be set up to carry out a volume measurement of the amount 215 of the dust particles 210 as irregular bodies, in which a mechanical level measurement is carried out via a float, optionally in combination with a potentiometer. Alternatively or additionally, a conductivity measurement, a capacitive and/or an optical level measurement of the quantity 215 of the dust particles 215 can be carried out in order to measure the level 146 or the volume V of the 215 of the dust particles 215. 4 shows a level measurement within the collecting container 110 using non-contact, ultrasound-based level sensors 145 in order to directly measure the volume V of the 215 dust particles 215 and thus be able to draw conclusions about wear and other variables such as the remaining coating thickness.

With the volume measurement, acceleration sensors 130 and force sensors 140 can be unnecessary. The deflection section 115 and the decoupling section 117 can therefore be dispensed with. However, the resulting volume V can change, for example the volume V can be compressed by vibrations and/or impacts caused by a road surface. Furthermore, dust particles 210 can be whirled up in the collecting container 210. Therefore, the embodiment of the measuring device 100 according to FIG. 4 can be used with the Embodiments of the measuring device 100 according to Figures 2 and 3 are combined in order to improve an estimate of the quantity 215 of the dust particles 210.

Alternatively, cumulative flow sensors can be used to measure volume flow, which are not dependent on prevailing accelerations a and forces F. For this purpose, a stream of dust particles 210 can be guided through a measuring section arranged between the friction partners 220, 230, 240 and the dust collection container 110. The volume V of the dust particles 210 can be measured based on the volume flow and/or the number of dust particles 210 can be recorded.

Figure 5 shows a schematic representation of a flowchart of a method 400 according to one aspect of the invention.

The method 400 is for calibrating a measuring device 100 as described with reference to Figures 1 to 4. When describing Figure 5, reference is made to Figures 1 to 4 and their description.

The method 400 has the step: Estimation 410 of the quantity 215 of dust particles 210 collected in the dust collection device 110. To calibrate the measuring device 100, the mass M and/or the volume V produced is determined using empirical test series based on test stand runs, field tests or others, if possible proven under real conditions. For this purpose, the amount 215 of dust particles 210 collected in the dust collection device 110 is recorded as described with reference to FIGS. 1 to 4.

5, the wear of the friction partners 220, 230, 240 is empirically determined 420. The friction partners 220, 230, 240 are examined and/or measured. In order to be able to make a sufficiently precise statement about the respective wear of the friction partners 220, 230, 240, the ratio of the wear of the individual friction partners 220, 230, 240 can be considered. It can be taken into account that the brake components generally do not reach their wear limit at the same time. For example, the brake pad assigns Brake disc wear has a ratio of approximately 2:1. With the information about the brake pad and brake disc wear and wear behavior, the respective state of wear of the friction partners 220, 230, 240 could then be inferred and the wear behavior of the brake as such could be qualitatively quantified. The amount of dust particles 210 collected in the dust collection device 110 can be used to determine the total wear of the friction partners 220, 230, 240.

In one example, the brake pad wear to disc wear is 1:1. If the total mass of the brake dust particles is 1 kg, 0.5 kg can be assigned to the brake disc, whereby 0.5 kg corresponds to wear on the brake disc of X%. Of the total mass of brake dust particles of 1 kg, 0.5 kg can be assigned to the brake pads. Assuming that both brake pads wear equally and equally, 0.25 kg can be assigned to the brake pad on the application side and the brake pad on the reaction side and 0.25 kg corresponds to Y% wear. A relationship is derived 430 between the amount 215 of the dust particles 210 and the closure of the friction partners 220, 230, 240. The relationship between the amount 215 of the dust particles 210 and the closure of the friction partners 220, 230, 240 is represented by a characteristic curve, which relates the amount 215 of dust particles 210 collected in the dust collection device 110 to the wear of the friction partners 220, 230, 240. Each of the friction partners 220, 230, 240 can have different wear and can thus be assigned its own characteristic curve and its own wear limits. Therefore, appropriate safety reserves can be provided and taken into account when defining characteristics. It can be taken into account that the brake dust particle mass does not have a homogeneous density, because, for example, the friction partners 220, 230, 240 brake disc have a density of approx. 7.85 g/cm ³ and the brake pad has a density of approx. 3 g/ cm ³ are different.

Information about the density of the respective friction partners 220, 230, 240 and their geometry allows conclusions to be drawn about the state of wear. The empirical determination 420 based on test series, test bench runs and/or field tests is carried out in order to obtain the most comprehensive database possible To maintain wear and to generally identify disturbances that occur in practice due to, for example, differential, tangential and radial wear and falsification of the measurement result.

The estimated amount 215 of dust particles 210 is checked for plausibility 440 based on the empirically determined wear. For this purpose, the amount 215 of dust particles 210 collected in the dust collection device 110 is calculated according to theory. By checking the plausibility 140, correction factors can be determined that are to be applied to the relationship between the amount 215 of the dust particles 210 and the closure of the friction partners 220, 230, 240. This makes it possible to take into account that, for example, leaks prevent the dust particles 210 from being completely collected. To check the plausibility, the affected friction partners 220, 230, 240 must be evaluated for their wear status using reliable and already established measuring methods. The average values determined are then included in the characteristic curve, including the correction factors as safety reserves as well as any leakage losses or insufficient degree of insulation or degree of efficiency in directing the particles to the dust collection container.

Reference symbols (part of the description):

100 measuring device

110 dust collection device

115 deflection section

116 bracket section

117 decoupling section

120 dust measuring arrangement

130 acceleration sensor

140 force sensor

145 level sensor

146 level

150 data processing device

151 quantity information

200 friction brake device

210 dust particles

215 amount of dust particles

220 friction partners

230 friction partners

240 friction partners

300a vehicle

300b commercial vehicle

310 surroundings

400 procedures

410 taxis

420 empirical investigation

430 Derive

440 Plausibility check

F force

M mass

M' mass

V volume

Claims

Patent claims:

1. Measuring device (100) for a friction brake device (200) for a vehicle (300a), in particular commercial vehicle (300b), comprising:

- a dust collecting device (110) for collecting dust particles (210) from two friction partners (220, 230, 240) of the friction brake device (200), the friction partners (220, 230, 240) being set up to generate a braking effect through friction with one another, and

- a dust measuring arrangement (120) for estimating a quantity (215) of dust particles (210) collected in the dust collecting device (110).

2. Measuring device according to claim 1, wherein the dust measuring arrangement (120) is set up to determine a mass (M) of the amount (215) of dust particles (210) and / or a volume (V) of the amount (215) of dust particles (210). .

3. Measuring device according to claim 1 or 2, wherein the measuring device (100) is set up to determine a mass (M ') of the dust collecting device (110) including the amount (215) of dust particles (210).

4. Measuring device according to claim 3, wherein the measuring device (100) has a deflection section (115) which can be deflected relative to the vehicle (300a), in particular commercial vehicle (300b), the deflection section (115) depending on a mass (M '). Dust collection device (110) including the amount (215) of dust particles (210) can be deflected.

5. Measuring device according to claim 4, wherein the dust collecting device (110) has a vehicle-mounted mounting section (116) and a deformable decoupling section (117) arranged between the mounting section (116) and the deflection section (115) for deflecting the deflection section (115), and the mass (M') of the dust collection device (110) including the amount (115) of dust particles

(110) can be determined based on a deformation of the decoupling section (117).

6. Measuring device according to one of the previous ones, wherein the measuring arrangement (100) has an acceleration sensor (130) and a force sensor (140) for measuring a force (F) acting on the dust collecting device (110).

7. Measuring device according to one of the preceding claims, wherein the measuring device (100) is set up to measure the fill level of the dust collecting device (110).

8. Measuring device according to one of the preceding claims, wherein the dust measuring arrangement (120) is set up for mechanical, electromechanical, resistive, capacitive and / or optical estimation of the amount (215) of dust particles (210).

9. Measuring device according to one of the preceding claims, wherein the dust collecting device (110) is evacuated from an environment (310) of the vehicle (300a), in particular commercial vehicle (300b).

10. Measuring device according to one of the preceding claims, wherein the measuring device (100) comprises a data processing device (150) and / or can be connected to a data processing device (150), the data processing device (150) for receiving the amount (215) of dust particles (210) relevant quantity information (151) is set up, and wherein the data processing device (150) is set up to carry out a determination of wear of the friction partners (220, 230, 240) depending on the quantity information (151).

11. Friction brake device (200), comprising a measuring device (100) according to one of the preceding claims.

12. Vehicle (300a), in particular commercial vehicle (300b), comprising a measuring device (100) according to one of claims 1 to 10 and / or a friction brake device (200) according to claim 11.

13. Method (400) for calibrating a measuring device (100) according to one of the preceding claims, wherein the method (400) has the steps:

- Estimating (410) the amount (215) of dust particles (210) collected in the dust collection device (110);

- Empirical determination (420) of the wear of the friction partners (220, 230, 240); and

- Deriving (430) a relationship between the amount (215) of dust particles (210) and the closure of the friction partners (220, 230, 240).

14. The method according to claim 13, wherein the method (400) comprises the step:

- Checking the plausibility (440) of the estimated quantity (215) of the dust particles (210) based on the empirically determined wear.