Brake testing method and brake assembly

Abstract

The invention relates to a brake testing method for vehicles for detecting and evaluating contact between at least one first contact element (1) and a second contact element (2) of a brake assembly. It is proposed that a vibration of the first contact element (1) is excited, which, when the first contact element (1) and the second contact element (2) make contact with each other, is transmitted to the second contact element (2) and can be measured at the second contact element (2), or at a component which contacts the second contact element (2) and is different from the first contact element (1), wherein a recording step (8) for measuring vibration is carried out, and wherein at least one recorded measurement signal is evaluated, with a check being made as to whether at least one vibration parameter value determined from the at least one measurement signal satisfies at least one test criterion with respect to the vibration parameter, with detection being performed as to whether at least the first contact element (1) and the second contact element (2) make contact with each other. In this way, an automatable and reliable brake test is achieved.

Description

[0001] Description

[0002] Brake testing procedure and brake arrangement

[0003] The invention relates to a brake testing method for vehicles, in particular for rail vehicles, for detecting and evaluating a formable mechanical contact between at least a first contact element and a second contact element of a brake arrangement, in which, for a braking process, at least the first contact element can be brought into mechanical contact with the second contact element, so that a relative speed can be reduced at least between the first contact element and the second contact element.

[0004] Brakes are safety-relevant components. Particularly in the rail vehicle sector, high safety levels must be maintained, which must be demonstrated through suitable verification and validation measures. Rail vehicles often have Safety Integrity Levels (SIL) 2 to 4 with very low failure probabilities (10 -2 up to 10 -5 ) to be fulfilled when a safety-relevant system is required.

[0005] Safety assessments in the rail vehicle sector are often required in accordance with the European Standard (EN) 50129 and / or EN 5126.

[0006] Brake inspections on rail vehicles are often carried out by trained personnel and can be very time-consuming, as a rail vehicle may have a large number of brake units to be inspected.

[0007] For example, WO 2018 / 201171 A1 discloses a method for automatic brake testing of rail vehicles. This method is used with a pneumatic braking system of a rail vehicle, which includes brake cylinders, brake linkages, and brake pads. Brake cylinder pressures and braking forces are measured on each car of the rail vehicle, evaluated by an evaluation unit, and transmitted to a central unit.

[0008] The invention is based on the objective of providing a brake testing method that is further developed compared to the prior art and in which it is possible to dispense with a measurement of a brake cylinder pressure.

[0009] According to the invention, this problem is solved by a brake testing method according to claim 1, in which, in a vibration excitation step, a vibration of the first contact element is excited by means of at least one vibration exciter, which, when the first contact element and the second contact element contact each other, is transmitted to the second contact element and can be measured by means of at least one vibration sensor on the second contact element or on a component contacting the second contact element that is different from the first contact element, wherein a detection step for vibration measurement is carried out by means of the at least one vibration sensor, and wherein, in an evaluation step, at least one measurement signal detected in the detection step is evaluated by means of at least one evaluation unit, whereby it is checked thatwhether at least one value of a vibration parameter determined from at least one measurement signal fulfills at least one test criterion with respect to the vibration parameter, whereby it is detected whether at least the first contact element and the second contact element are in contact with each other.

[0010] This measure results in a low-effort and reliable brake testing method. For example, to perform the brake testing method according to the invention, it is not necessary to measure fluid pressure in a pneumatic or hydraulic brake system using a pressure sensor. Likewise, no brake force measurement, such as measuring brake linkage force, brake pad contact force, or brake shoe force, etc., is required. Furthermore, the need to calculate a braking force, for example from brake cylinder pressure, etc., can be dispensed with.

[0011] The brake testing method according to the invention is flexible in its application. For example, it can be used to perform brake tests before a vehicle is put into operation or before it departs. It is also conceivable to apply the brake testing method, for example, in connection with maintenance or repair work on a vehicle (e.g., on its brake equipment), etc.

[0012] It is possible to apply the brake testing method according to the invention to a plurality of brake units on a vehicle (for example, to all block and / or disc brake units of a rail vehicle with a plurality of cars, etc.). This allows, for example, automated brake testing, the results of which can be output, stored, and further processed, etc.

[0013] According to the invention, it is possible that the induced vibration is not measurable because, for example, although a braking request occurs (e.g., by actuating a brake control element in a vehicle), the mechanical contact between the first contact element and the second contact element is not established, for example, due to a fault or defect, and the induced vibration is therefore not transmitted to the second contact element. The detection step is nevertheless carried out. In such a scenario, the value determined from the measurement signal can, for example, be zero, thereby allowing the fault or defect to be detected.

[0014] According to the invention, it is further conceivable that, following a braking request, the mechanical contact between the first contact element and the second contact element becomes too weak (e.g., again due to a malfunction or fault), resulting in only a weak transmission of the induced vibration and, for example, the value determined from the measurement signal falling below a defined limit. Such a scenario can, in turn, be detected as a malfunction or fault.

[0015] With a properly formed mechanical contact between the first and second contact elements, the value determined from the measurement signal may be greater than the limit value due to a strong transmission of the vibration to the second contact element. Such a condition can, in turn, be detected using the brake testing method according to the invention.

[0016] A malfunction, a detected fault or a detected fault-free state of the brake assembly detected by means of the brake testing method according to the invention can, for example, be output (e.g., visually via a display and / or acoustically via a loudspeaker, etc.).

[0017] The vibration parameter to which the value determined from the measurement signal is assigned can be, for example, a frequency, an amplitude, or an acoustic impedance, etc. The brake assembly can, for example, be part of a friction brake (e.g., of the bogies of a rail vehicle). It is possible, for example, that the first contact element and the second contact element are designed as friction partners. The first contact element could, for example, be a brake pad and the second contact element a wheel against which the first brake pad can be applied. Alternatively, the first contact element could also be a brake lining and the second contact element a brake disc (e.g., a wheel brake disc or a shaft brake disc) against which the first brake lining can be applied, etc.

[0018] The component different from the first contact element, which can contact the second contact element, can, for example, be a third contact element of the brake assembly (e.g., a second brake pad that can be applied to the wheel or a second brake lining that can be applied to the brake disc, etc.). The vibration exciter can, for example, be connected to the first contact element, the vibration sensor, for example, to the second contact element or to the component different from the first contact element that can contact the second contact element, etc. Further advantageous embodiments of the brake testing method according to the invention are described in the dependent claims.

[0019] A test criterion that is easy to handle (e.g., computer-aided) can be obtained, for example, if in the evaluation step at least one limit value comparison is used to check whether the at least one value of the vibration parameter determined from the at least one measurement signal fulfills the at least one test criterion.

[0020] A limit value used in the limit value comparison, for example, can be determined from tests (e.g., from test bench or field tests), calculations or simulations, etc.

[0021] To detect a sufficiently formed contact between the first contact partner and the second contact partner, or a non-formed or insufficiently formed mechanical contact between the first contact partner and the second contact partner, it can be helpful to check in the evaluation step whether at least one first value of the vibration parameter determined from the at least one measurement signal with respect to the second contact element or component fulfills a first test criterion, which is then fulfilled if an absolute value of the at least first value is equal to a first limit value with respect to the vibration parameter or greater than the first limit value.

[0022] As an alternative or in addition to the first test cut, it may also be advisable to check in the evaluation step whether at least a difference between at least one second value of the vibration parameter of a natural resonance of an arrangement consisting of at least the first contact element and the second contact element, determined from the at least one measurement signal, and at least one reference value of the vibration parameter of the natural resonance of the arrangement in a state in which at least the first contact element and the second contact element are in perfect contact with each other, fulfills a second test criterion, which is then fulfilled if an absolute value of the at least one difference is equal to or less than a second limit value with respect to the vibration parameter.

[0023] If, for example, the second value and the reference value deviate from each other, and this deviation is outside a tolerance, this indicates a malfunction or fault in the brake assembly. Conversely, if the deviation between the second value and the reference value is within the tolerance or even zero, this indicates a resonance behavior of the brake assembly, which suggests sufficient contact between the first and second contact elements and makes a malfunction or fault in the brake assembly seem unlikely, etc.A preferred solution is obtained if the at least one measurement signal, from which the at least one value of the vibration parameter is determined, is detected before a release process of at least the first contact element and the second contact element, wherein in a control step after the release process at least one control measurement signal is detected by means of the at least one vibration sensor and at least one control value with respect to the vibration parameter is determined from the at least one control measurement signal, and wherein in the control step it is checked whether the at least one value and the at least one control value satisfy a control criterion, which is fulfilled if an absolute value of the at least one value is greater than an absolute value of the at least one control value.

[0024] This measure enables a functional check of the brake testing procedure. Fulfillment of the control criterion indicates that the brake testing procedure is functioning correctly, since the transmitted vibration is detectable by the vibration sensor before the release process, but is no longer transmitted to the second contact element after the release process and is therefore no longer detectable. In such a scenario, the value can be, for example, > 0 Hz and the control value 0 Hz. If, for example, the value has a magnitude greater than 0 Hz and the control value has the same magnitude despite the release process, this may indicate a malfunction or error in the brake testing procedure (e.g., caused by a sensor error in the vibration sensor, etc.).

[0025] A promising field of application for the brake testing method according to the invention is opened up by a brake arrangement with at least one brake testing device for carrying out a brake testing method according to the invention for vehicles, in particular for rail vehicles, the brake arrangement comprising at least a first contact element and a second contact element, wherein for a braking operation at least the first contact element can be brought into mechanical contact with the second contact element, so that a relative velocity at least between the first contact element and the second contact element can be reduced, wherein the brake testing device is configured for detecting and evaluating the mechanical contact between at least the first contact element and the second contact element, wherein the brake testing device comprises at least one vibration exciter, at least one vibration sensor and at least one evaluation unit,which is connected to at least one vibration sensor and is configured to excite a vibration of the first contact element by means of at least one vibration exciter connected to the first contact element, which, when the first contact element and the second contact element contact each other, is transmitted to the second contact element and can be measured by means of at least one vibration sensor on the second contact element or on a component of the brake arrangement contacting the second contact element that is different from the first contact element, wherein the at least one vibration sensor is connected to the second contact element or to the component, to perform a detection step for vibration measurement by means of the at least one vibration sensor, and to evaluate and check at least one measurement signal detected in the detection step by means of the at least one evaluation unit.to determine whether at least one value of a vibration parameter, determined from at least one measurement signal, fulfills at least one test criterion with respect to the vibration parameter, and to detect whether at least the first contact element and the second contact element are in contact with each other.

[0026] Brakes for vehicles are safety-relevant devices, which is why easy-to-use and reliable testing devices such as the brake testing device of the brake arrangement according to the invention are important.

[0027] The brake testing device can be used, for example, to perform brake tests or brake checks during maintenance or repair procedures, or during test or approval drives, etc.

[0028] The brake arrangement according to the invention can, for example, comprise a plurality of brake units, with which, for instance, all the cars of a rail vehicle can be equipped. This enables automated brake testing. Automated brake testing can, for example, reduce inspection effort in rail vehicles with many cars (e.g., freight trains, etc.).

[0029] The brake arrangement can, for example, be a friction brake arrangement. The first contact element can be, for example, the first brake pad, the second contact element, for example, the wheel against which the first brake pad can be applied, etc. It is also possible that the first contact element is, for example, the first brake lining and the second contact element, for example, a brake disc (e.g., a wheel brake disc or shaft brake disc) against which the first brake lining can be applied, etc.

[0030] The component different from the first contact element, which can contact the second contact element, could be, for example, a third contact element of the brake assembly (e.g., a second brake pad that can be applied to the wheel or a second brake lining that can be applied to the brake disc, etc.). The vibration exciter could, for example, be connected to the first contact element, the vibration sensor to the second contact element, or to the component different from the first contact element that can contact the second contact element, etc. The evaluation unit could, for example, be an industrial computer or on-board computer with a processor, memory, and computer software. It could be located, for example, directly at the vibration sensor or at a distance from it.The evaluation unit can be connected to the vibration sensor, for example, via cable or wirelessly. It is conceivable that the evaluation unit is located inside a vehicle (e.g., in a car body) or outside the vehicle (e.g., in a track area or maintenance bay, etc.). The evaluation unit could be a central unit for all vibration sensors of the brake testing system, to which each vibration sensor is connected. However, it is also conceivable that each individual vibration sensor is connected to its own evaluation unit. Furthermore, it is conceivable that data from individual evaluation units (e.g., via cable or wirelessly) is transmitted to a central computer, etc. The evaluation unit and / or the central computer, if one is provided, could, for example, have output devices (e.g., displays or speakers) through which test results from the brake testing system can be displayed, etc.

[0031] The vibration exciter can be designed, for example, as an electromechanical vibration exciter (e.g., as an electrodynamic shaker) or as a piezoelectric vibration exciter (e.g., as a device with a quartz crystal oscillator).

[0032] The vibration sensor can be designed, for example, as an electromechanical vibration sensor (e.g., as an accelerometer based on a micro-electro-mechanical system, i.e., as a MEMS accelerometer) or as a piezoelectric vibration sensor (e.g., as a piezoelectric accelerometer) for detecting vibrations, etc.

[0033] The invention will now be explained in more detail using exemplary embodiments.

[0034] Figure 1 shows, by way of example: A flowchart for an exemplary embodiment of a brake testing method according to the invention for a friction brake of a rail vehicle, and

[0035] Fig. 2: A schematic side view of an exemplary embodiment of a brake arrangement according to the invention with a brake testing device, wherein the brake arrangement is designed as a friction brake of a chassis of a rail vehicle.

[0036] Fig. 1 shows a flowchart for an exemplary embodiment of a brake testing method according to the invention for a friction brake of a rail vehicle designed as a freight train.

[0037] Using the brake testing method, a detectable mechanical contact is carried out between a first contact element 1 and a second contact element 2 of a brake arrangement, as shown by way of example in Fig. 2, on the one hand, and between the second contact element 2 and a third contact element 3 of the brake arrangement on the other hand.

[0038] In the brake arrangement, for a braking process the first contact element 1 and the third contact element 3 can be brought into mechanical contact with the second contact element 2, so that a relative speed between the first contact element 1 and the third contact element 3 on the one hand and the second contact element 2 on the other hand can be reduced.

[0039] To initiate the brake test procedure, which is carried out using a brake test device as shown by way of example in Fig. 2, a brake request is triggered by means of a brake control element in a driver's cab of the rail vehicle (brake request step 4). This generates a compressed air signal which acts via brake actuators on the first contact element 1 and the third contact element 3, so that these are applied to the second contact element 2.

[0040] It is possible that due to a malfunction or fault (for example, in the brake actuators), the first contact element 1 and the third contact element 3 are not, or only insufficiently, connected to the second contact element 2. Such a fault condition, as well as a condition in which the first contact element 1 and the third contact element 3 are sufficiently connected to the second contact element 2, can be detected using the brake testing procedure.

[0041] In a vibration excitation step 5, a vibration of the first contact element 1 is excited by means of a vibration exciter 6. This vibration is transmitted to the second contact element 2 and the third contact element 3 when the first contact element 1, the second contact element 2, and the third contact element 3 are in contact with each other. The vibration can then be measured by means of a vibration sensor 7 on the second contact element 2 or on the third contact element 3, which is a component different from the first contact element 1 and is in contact with the second contact element 2. A detection step 8 for vibration measurement is then performed on the third contact element 3 using the vibration sensor 7. Detection step 8 is carried out regardless of whether the first contact element 1, the second contact element 2, and the third contact element 3 are in contact with each other or not.

[0042] In evaluation step 9, the measurement signals acquired in acquisition step 8 are evaluated using an evaluation unit 10. This process checks whether the vibration parameter values ​​determined from the measurement signals meet a first test criterion and a second test criterion with respect to the vibration parameters.

[0043] The vibration parameters are frequencies of the vibration. However, according to the invention, it is also possible for the vibration parameters to be, for example, amplitudes of the vibration or acoustic impedances, etc.

[0044] If the first contact element 1 and the third contact element 3 are not connected to the second contact element 2, the values ​​are 0 Hz. Otherwise, the values ​​are > 0 Hz.

[0045] In evaluation step 9, limit value comparisons are used to check whether the vibration parameter values ​​meet the first and second test criteria. Regarding the first test criterion, it is checked whether the first frequency values ​​determined from the measurement signals for the third contact element 3, due to the excited vibration, meet the first test criterion. The first test criterion is met if the absolute values ​​of the first frequency values ​​are equal to or greater than a first frequency limit. The first frequency limit is determined empirically in field tests with a reference brake arrangement on a reference rail vehicle and defines a lower limit at which the first contact element 1, the second contact element 2, and the third contact element 3 make contact with each other in such a way that a permissible braking effect is generated.

[0046] If the first test criterion is met, it can be assumed that the first contact element 1 and the third contact element 3 are sufficiently in contact with the second contact element 2 and that the vibration is adequately transmitted to the third contact element 3. If the first test criterion is not met, this indicates that the first contact element 1 and the third contact element 3 are not in contact with the second contact element 2, or not sufficiently so, and that the vibration is not transmitted to the third contact element 3, or not at all.

[0047] According to the invention, it is also conceivable to use the first test criterion to test, for example, not the vibration response of the third contact element 3, but rather that of the second contact element 2, etc. With regard to the second test criterion, it is checked whether a difference between a second frequency value of a natural resonance of an arrangement consisting of the first contact element 1, the second contact element 2, and the third contact element 3, determined from the measurement signals, and a reference frequency value of the natural resonance of this arrangement in a state in which the first contact element 1, the second contact element 2, and the third contact element 3 are in perfect contact with each other, satisfies the second test criterion. The second test criterion is satisfied if the absolute value of the difference is equal to or less than a second frequency limit.The second frequency limit is determined empirically in field tests with the reference brake arrangement on the reference rail vehicle and defines a maximum permissible deviation from a target resonance behavior with a faultless mechanical contact between the first contact element 1, the second contact element 2 and the third contact element 3.

[0048] If the second test criterion is met, it can be assumed that the first contact element 1 and the third contact element 3 are sufficiently in contact with the second contact element 2, since the brake assembly exhibits a resonance behavior comparable to that of the reference brake assembly in a target state. If the second test criterion is not met, this indicates that the first contact element 1 and the third contact element 3 are not in contact with the second contact element 2, or not sufficiently so, since the brake assembly exhibits a resonance behavior that deviates significantly from that of the reference brake assembly in the target state.

[0049] The measurement signals, from which the first frequency values ​​and the second frequency values ​​with respect to the vibration parameters are determined, are recorded from each other before a release process of the first contact element 1, the second contact element 2 and the third contact element 3, wherein in this exemplary embodiment of a brake testing method according to the invention it is assumed by way of example that the first contact element 1 and the third contact element 3 are actually applied to the second contact element 2 after the brake request step 4.

[0050] After the loosening process, a control step 11 is carried out in which control measurement signals are recorded using the vibration sensor 7, from which control frequency values ​​are determined.

[0051] In control step 11, it is checked whether the first frequency values ​​and the control frequency values ​​fulfill a control criterion. The control criterion is fulfilled if the absolute values ​​of the first frequency values ​​are greater than the absolute values ​​of the control frequency values. In this exemplary embodiment of a brake testing method according to the invention, the first frequency values ​​are > 0 Hz and the control frequency values ​​are 0 Hz.

[0052] If the control criterion is met, this indicates that the release process is detected by the brake testing device and therefore the brake testing device is functioning correctly. If the control criterion is not met, this indicates that the release process is not detected or not detected correctly by the brake testing device and the brake testing device (e.g., the vibration sensor 7) is faulty.

[0053] The results of evaluation step 9 and control step 11 are displayed on a screen 12 of the evaluation unit 10 (output step 13). If a fault is detected in the brake assembly (e.g., if the first test criterion is not met) or in the brake testing device (if the control criterion is not met), an error message is displayed on screen 12.

[0054] To indicate that the brake assembly and brake testing device are in a fault-free condition, the first test criterion, the second test criterion, and the control criterion must all be met. Such a fault-free condition is then indicated in output step 13 via display 12.

[0055] Figure 2 shows a schematic side view of an exemplary embodiment of a brake arrangement according to the invention with a brake testing device, wherein the brake arrangement is designed as a friction brake of the chassis of a rail vehicle. The rail vehicle comprises a plurality of freight wagons.

[0056] The brake assembly is designed to perform a brake test procedure according to Fig. 1 and comprises a first contact element 1, a second contact element 2, and a third contact element 3, as well as pneumatic-mechanical brake actuators (not shown in Fig. 2). The brake actuators generate actuation and release forces, which apply and detach the first contact element 1 and the third contact element 3 from the second contact element 2, respectively, to increase and decrease the braking effect. The brake actuators are connected to a compressed air supply system of the rail vehicle (not shown in Fig. 2) and to a bogie frame of the chassis (also not shown in Fig. 2). A first brake actuator is connected to the first contact element 1, and a second brake actuator to the third contact element 3.The first contact element 1, the second contact element 2 and the third contact element 3 are designed as friction partners of the friction brake.

[0057] The first contact element 1 is designed as the first brake pad, the third contact element 3 as the second brake pad and the second contact element 2 as the wheel of the chassis.

[0058] However, according to the invention it is also conceivable that, for example, the first contact element 1 is designed as the first brake pad, the third contact element 3 as the second brake pad and the second contact element 2 as a brake disc (e.g. as a wheel brake disc or as a shaft brake disc) etc.

[0059] For a braking process, the first contact element 1 and the third contact element 3 can be brought into mechanical contact with the second contact element 2 by means of the brake actuators, so that a relative speed between the first contact element 1 and the third contact element 3 on the one hand and the second contact element 2 on the other hand can be reduced, whereby the second contact element 2, designed as a wheel, and thus the rail vehicle can be braked.

[0060] The brake testing device is designed to detect and evaluate the mechanical contact between the first contact element 1 and the third contact element 3 on the one hand and the second contact element 2 on the other hand and includes a vibration exciter 6, a vibration sensor 7 and an evaluation unit 10 which is connected to the vibration sensor 7.

[0061] The vibration exciter 6, which is connected to the first contact element 1, is designed as an electrodynamic shaker and thus as an electromechanical vibration exciter. According to the invention, however, it is also possible for the vibration exciter 6 to be designed, for example, as a piezoelectric vibration exciter (e.g., as a device with a quartz crystal oscillator), etc.

[0062] The vibration sensor 7 is designed as an accelerometer based on a micro-electromechanical system, i.e., as a MEMS accelerometer, and thus as an electromechanical vibration sensor. However, according to the invention, it is also conceivable that the vibration sensor 7 is designed, for example, as a piezoelectric vibration sensor (e.g., as a piezoelectric accelerometer), etc.

[0063] The brake testing device is designed to excite a vibration of the first contact element 1 by means of the vibration exciter 6. This vibration, when the first contact element 1, the second contact element 2, and the third contact element 3 contact each other, as shown by way of example in Fig. 2, is transmitted to the second contact element 2 and the third contact element 3 and can be measured by means of the vibration sensor 7 on the second contact element 2 or on a component of the brake assembly other than the first contact element 1 that contacts the second contact element 2, namely the third contact element 3. The vibration sensor 7 is connected to this component, i.e., to the third contact element 3, for measuring the vibration transmitted from the first contact element 1.However, according to the invention, it is also conceivable that the vibration sensor 7 is connected to the second contact element 2 for measuring the vibration transmitted by the first contact element 1.

[0064] The brake testing device is further equipped to perform a detection step 8 for vibration measurement using the vibration sensor 7, to evaluate measurement signals recorded in the detection step 8 using the evaluation unit 10 and to check whether values ​​of vibration parameters determined from the measurement signals meet test criteria with regard to the vibration parameters.

[0065] The evaluation unit 10 is designed as an on-board computer with a processor, memory, and a computer program for determining the values ​​from the measurement signals and for processing the values, etc., and is arranged in a driver's cab of the rail vehicle (not shown in Fig. 2). According to the invention, however, it is also conceivable to arrange the evaluation unit 10 outside the rail vehicle, for example, directly at the vibration sensor 7, near the track, or in a maintenance stand, etc.

[0066] The evaluation unit 10 is connected to the vibration sensor 7 via a cable. However, according to the invention, it is also possible for the evaluation unit 10 to be connected to the vibration sensor 7 wirelessly.

[0067] The evaluation unit 10 has a display 12 for outputting results of the brake testing procedure.

[0068] The vibration exciter 6, the vibration sensor 7 and the evaluation unit 10 are connected to an electrical power supply not shown in Fig. 2.

[0069] Regardless of the grammatical gender of a given term, persons of male, female, or other gender identities are included. Reference list

[0070] 1 First contact element

[0071] 2 Second contact element 3 Third contact element

[0072] 4 Brake request step

[0073] 5th vibration excitation step

[0074] 6 vibration exciters

[0075] 7 Vibration sensor 8 Detection step

[0076] 9 Evaluation step

[0077] 10 evaluation units

[0078] 11 Control step

[0079] 12 Display 13 Output step

Claims

Patent claims 1. Brake testing method for vehicles, in particular for rail vehicles, for detecting and evaluating a formable mechanical contact between at least a first contact element (1) and a second contact element (2) of a brake arrangement, in which, for a braking process, at least the first contact element (1) can be brought into mechanical contact with the second contact element (2) so that a relative velocity at least between the first contact element (1) and the second contact element (2) can be reduced, characterized in that in a vibration excitation step (5) a vibration of the first contact element (1) is excited by means of at least one vibration exciter (6), which, when the first contact element (1) and the second contact element (2) contact each other,the vibration is transferred to the second contact element (2) and can be measured by means of at least one vibration sensor (7) on the second contact element (2) or on a component contacting the second contact element (2) that is different from the first contact element (1), wherein a detection step (8) for vibration measurement is carried out by means of the at least one vibration sensor (7), and wherein in an evaluation step (9) at least one measurement signal detected in the detection step (8) is evaluated by means of at least one evaluation unit (10), wherein it is checked whether at least one value of a vibration parameter determined from the at least one measurement signal fulfills at least one test criterion with respect to the vibration parameter, and wherein it is detected whether at least the first contact element (1) and the second contact element (2) are in contact with each other.

2. Brake testing method according to claim 1, characterized in that the vibration parameter is a frequency, an amplitude or an acoustic impedance.

3. Brake testing method according to claim 1 or 2, characterized in that in the evaluation step (9) it is checked by means of at least one limit value comparison whether the at least one value of the vibration parameter determined from the at least one measurement signal fulfills the at least one test criterion.

4. Brake testing method according to claim 3, characterized in that in the evaluation step (9) it is checked whether at least one of the at least one measurement signal The first determined value of the vibration parameter with respect to the second contact element (2) or component fulfills a first test criterion, which is then fulfilled if an absolute value of at least the first value is equal to a first limit value with respect to the vibration parameter or is greater than the first limit value.

5. Brake testing method according to claim 3 or 4, characterized in that in the evaluation step (9) it is checked whether at least a difference between at least one second value of the vibration parameter of a natural resonance of an arrangement consisting of at least the first contact element (1) and the second contact element (2) determined from the at least one measurement signal and at least one reference value of the vibration parameter of the natural resonance of the arrangement in a state in which at least the first contact element (1) and the second contact element (2) are in faultless contact with each other, fulfills a second test criterion, which is then fulfilled if an absolute value of the at least one difference is equal to or less than a second limit value with respect to the vibration parameter.

6. Brake testing method according to one of claims 1 to 5, characterized in that the at least one measurement signal, from which the at least one value of the vibration parameter is determined, is detected from each other before a release process of at least the first contact element (1) and the second contact element (2), wherein in a control step (11) after the release process at least one control measurement signal is detected by means of the at least one vibration sensor (7) and at least one control value with respect to the vibration parameter is determined from the at least one control measurement signal, and wherein in the control step (11) it is checked whether the at least one value and the at least one control value satisfy a control criterion, which is fulfilled if an absolute value of the at least one value is greater than an absolute value of the at least one control value.

7. Brake arrangement with at least one brake testing device configured for carrying out a brake testing procedure according to one of claims 1 to 6, for vehicles, in particular for rail vehicles, the brake arrangement comprising at least a first contact element (1) and a second contact element (2), wherein, for a braking operation, at least the first contact element (1) can be brought into mechanical contact with the second contact element (2), such that a relative velocity can be established at least between the first contact element (1) and the the second contact element (2) is reducible, wherein the brake testing device is configured for detecting and evaluating the mechanical contact between at least the first contact element (1) and the second contact element (2), characterized in that the brake testing device has at least one vibration exciter (6), at least one vibration sensor (7) and at least one evaluation unit (10) which is connected to the at least one vibration sensor (7) and is configured to excite a vibration of the first contact element (1) by means of the at least one vibration exciter (6) which is connected to the first contact element (1), which, when the first contact element (1) and the second contact element (2) contact each other, is transmitted to the second contact element (2) and is detected by means of the at least one vibration sensor (7) on the second contact element (2) or on a contacting the second contact element (2),The vibration of a component of the brake assembly other than the first contact element (1) is measurable, wherein the at least one vibration sensor (7) is connected to the second contact element (2) or to the component, using the at least one vibration sensor (7) to perform a detection step (8) for vibration measurement, and to evaluate at least one measurement signal detected in the detection step (8) using the at least one evaluation unit (10) and to check whether at least one value of a vibration parameter determined from the at least one measurement signal fulfills at least one test criterion with respect to the vibration parameter, and to detect whether at least the first contact element (1) and the second contact element (2) are in contact with each other.

8. Brake arrangement according to claim 7, characterized in that the component is designed as a third contact element (3) of the brake arrangement.

9. Brake arrangement according to claim 7 or 8, characterized in that at least the first contact element (1) and the second contact element (2) are designed as friction partners of a friction brake.

10. Brake arrangement according to claim 9, characterized in that at least the first contact element (1) is designed as a brake pad and the second contact element (2) is designed as a wheel.

11. Brake arrangement according to claim 9, characterized in that at least the first contact element (1) is designed as a brake pad and the second contact element (2) is designed as a brake disc.

12. Brake arrangement according to one of claims 7 to 11, characterized in that the at least one vibration exciter (6) is designed as an electromechanical vibration exciter.

13. Brake arrangement according to one of claims 7 to 11, characterized in that the at least one vibration exciter (6) is designed as a piezoelectric vibration exciter.

14. Brake arrangement according to one of claims 7 to 13, characterized in that the at least one vibration sensor (7) is designed as an electromechanical vibration sensor.

15. Brake arrangement according to one of claims 7 to 13, characterized in that the at least one vibration sensor (7) is designed as a piezoelectric vibration sensor.

Images