DE102021112130A1 - Brake caliper unit with a wear sensor device, and method for detecting wear of brake pads and brake disc of a brake caliper unit of a disc brake - Google Patents

Abstract

A brake caliper unit (1, 1') of a disc brake, in particular for rail vehicles, comprises two caliper levers (2, 3), a brake cylinder (8), an adjuster module (9), brake linings (4, 5) and a wear sensor device (11, 11' , 11") with at least one sensor element (24, 24') and an evaluation unit (12). The wear sensor device (11, 11', 11") is parallel to the adjuster module (9) and/or the brake cylinder (8) between the two pincer levers (2, 3) articulated on these in coupling axes. And a method for determining wear of brake pads (4, 5) and brake disc of a brake caliper unit (1, 1') of a disc brake.

Description

The invention relates to a brake caliper unit with a wear sensor device according to the preamble of claim 1. The invention also relates to a method for detecting wear of brake pads and brake disc of a brake caliper unit of a disc brake.

Such brake caliper assemblies are widely used in the railway industry for their braking performance, particularly for locomotives, trams and multiple-unit trains.

During daily braking operation, the brake pads and the brake disc wear out. For safety reasons, the condition of the brakes must be checked regularly, with the current inspection method relying on the visual inspection of brake pads and brake discs by maintenance personnel. This is costly and requires well-trained maintenance personnel.

Automatic wear detection is known for disc brakes, for example from document WO 2018/178018 A1 . According to this document, a non-contact actuation sensor is used on or in the brake pad holder or on or in a brake caliper lever connected to the brake pad holder. The sensor measures the distance to a side surface of the brake disc in order to be able to calculate the wear on the brake pads. However, such an arrangement is considered disadvantageous as it is too vulnerable, requiring too much protection for robust operation.

In addition, only the wear of a brake pad is detected and wear of the disc cannot be determined.

The object of the invention is to provide an improved brake caliper unit with automatic wear detection for brake pads and brake disc, while at the same time reducing costs and maintenance time.

A further object is to specify an improved method for detecting wear of brake pads and brake disc of a brake caliper unit of a disc brake.

The object is solved by the subject matter of claim 1.

The further object is achieved by a method according to claim 14

One idea of the invention consists in detecting the wear by means of at least one wear sensor device, which is attached parallel to a brake cylinder and/or an adjuster module of the brake caliper unit.

A brake caliper unit according to the invention, in particular for rail vehicles, includes two caliper levers, a brake cylinder, an adjuster module, brake linings and a wear sensor device with at least one sensor element and an evaluation unit. The wear sensor device is articulated parallel to the adjuster module and/or the brake cylinder between the two caliper levers on these in coupling axes.

In this way, a robust and simple wear sensor device is made possible, which can be installed and retrofitted in a simple manner.

A method according to the invention for determining wear of brake pads and brake disc of a brake caliper unit of a disc brake, in particular for rail vehicles, having two caliper levers, a brake cylinder, brake pads and a wear sensor device with an evaluation unit comprises the method steps (VS1) detecting an initial position and detecting changes in length of a distance of Coupling points of the two caliper levers during braking processes with the wear sensor device, the changes in length of the distance being converted by means of a movement conversion device into changes in the angle of rotation of a rotary angle sensor, or the changes in length of the distance being detected by measuring a distance between a sensor element of a contact-based and/or a contactless distance measuring sensor and a reference portion of the wear sensing device; (VS2) generating measurement signals based on the measurement values recorded in this way; and forwarding the measurement signals to an evaluation unit; and (VS3) evaluation of the measurement signals by the evaluation unit in such a way that the wear values for lining wear and disc wear of the brake caliper unit summed up in the measurement signals are determined.

A particular advantage here is that an automatic determination not only of pad wear but also of disc wear is easily possible.

Further advantageous configurations are specified in the dependent claims.

In one embodiment, the wear sensor device is articulated in coupling axes of coupling points in which the brake cylinder and/or the adjuster module is/are articulated, wherein the coupling points are arranged at a distance from each other. These coupling points already exist and can be used easily.

A further embodiment provides that the wear sensor device has a movement conversion unit, which converts a longitudinal movement as a change in the distance between the coupling points into a rotary movement. This results in an advantageously compact structure that is easy to seal.

It is advantageous for such a compact structure if, in one embodiment, the movement conversion unit of the wear sensor device has a threaded tube with an internal thread and a threaded spindle with an external thread, the internal thread and the external thread being in engagement and forming a movement thread.

In a further embodiment, it is provided that the threaded tube is connected to the wear sensor device in a rotationally fixed manner and the threaded spindle is rotatably mounted and coupled to the at least one sensor element, or the threaded spindle is connected in a rotationally fixed manner to the wear sensor device and the threaded tube is rotatably mounted and connected to the at least one Sensor element is coupled. This structure is simple and compact.

It is advantageous here if the at least one sensor element (24) is a rotary angle sensor, since such a component is available on the market at low cost and with high quality.

A further embodiment provides that the wear sensor device comprises fastening elements, a sensor housing, a housing, the movement conversion unit, at least one bearing and the at least one sensor element, the wear sensor device being articulated with one fastening element each in the coupling axes of the coupling points. Such attachment is simple and inexpensive.

Yet another embodiment provides that the housing tube and the threaded tube are arranged together in a telescopic manner, with the housing tube being pushed onto the threaded tube. An advantageously space-saving structure is thus achieved.

In an alternative embodiment, the wear sensor unit has at least one contactless distance measuring sensor. An advantageous compact and simple structure can thus be possible.

It is advantageous if the at least one contactless distance measuring sensor is an ultrasonic sensor, a radar sensor and/or an optical distance measuring sensor. For this purpose, commercially available components can be used, which are already provided with integrated electronic measurement data processing circuits.

It is also advantageous for a compact and simple structure if the wear sensor device has fastening elements, a housing tube and the at least one contactless distance measuring sensor, with the housing tube and the at least one contactless distance measuring sensor being arranged telescopically together.

In yet another embodiment, the at least one contactless distance measuring sensor interacts with a reference section of the wear sensor device and detects a distance between the sensor element and the reference section as a measure of a change in the distance between the coupling points. This is advantageous because only a small number of components are required.

The brake caliper unit is designed for a pneumatic disc brake. This advantageously expands the range of use.

In one embodiment of the method, the contactless distance measuring sensor is an ultrasonic sensor, a radar sensor and/or an optical distance measuring sensor. These components are advantageously available on the market in highly integrated configurations as ready-to-use functional components.

If the evaluation unit compares the determined wear values with previously stored limit values for changing the brake pads (or replacing a brake pad) and/or changing the brake discs (or replacing the brake disc) and outputs displays, warnings, etc. on suitable media based on the comparison results, maintenance times can advantageously be planned.

It is also a great advantage that the evaluation unit uses comparative values to determine wear of the brake pads and brake disc of the entire disc brake from all of the measured values recorded and the wear values determined from them.

Exemplary embodiments of the invention are described below with reference to the accompanying drawings.

• 1-2 schematische Draufsichten einer konventionellen und einer kompakten Bremszangeneinheit;
• 3 eine schematische Schnittansicht einer erfindungsgemäßen Bremszangeneinheit mit einem ersten Ausführungsbeispiel einer erfindungsgemäßen Verschleißsensorvorrichtung;
• 4 eine schematische, vergrößerte Schnittansicht eines Sensorgehäuses nach 3;
• 5 eine Schnittansicht einer Variation des ersten Ausführungsbeispiels der Verschleißsensorvorrichtung nach 3;
• 6 eine Schnittansicht eines zweiten Ausführungsbeispiels der Verschleißsensorvorrichtung nach 3;
• 7 ein schematisches Schaubild von Verschleißgraphen; und
• 8 ein schematisches Flussdiagramm eines Ausführungsbeispiels eines erfindungsgemäßen Verfahrens.

Show it:

• 1-2 schematic top views of a conventional and a compact brake caliper unit;
• 3 a schematic sectional view of a brake caliper unit according to the invention with a first embodiment of a wear sensor device according to the invention;
• 4 a schematic, enlarged sectional view of a sensor housing 3 ;
• 5 a sectional view of a variation of the first embodiment of the wear sensor device 3 ;
• 6 a sectional view of a second embodiment of the wear sensor device 3 ;
• 7 a schematic diagram of wear graphs; and
• 8th a schematic flow chart of an embodiment of a method according to the invention.

Coordinates x, y, z are used in the figures for orientation. The coordinate x runs in the longitudinal direction of the brake caliper unit 1, the coordinate y transversely thereto, the coordinate z forming a vertical direction here. Other positions of the brake caliper unit 1 are of course also possible.

1 shows a schematic plan view of a conventional brake caliper unit 1. In 2 Fig. 12 is a schematic plan view of a conventional so-called compact brake caliper unit 1'.

Each of these brake caliper units 1, 1' forms a disc brake for a rail vehicle and includes a first caliper lever 2 and a second caliper lever 3, two brake pads 4, 5, a brake cylinder 8 and an adjuster module 9 for wear adjustment.

The brake caliper unit 1 has a brake cylinder 8 with an integrated adjuster module 9 , the other brake caliper unit 1 ′ having a separate brake cylinder 8 and a separate adjuster module 9 .

Both caliper levers 2, 3 are attached in a respective joint 2a, 3a so that they can pivot about a respective lever axis in the z-direction, which will not be described in detail.

On one side of the caliper levers 2, 3, the brake linings 4, 5 are pivotably attached via pad holders at the free ends of the caliper levers 2, 3 in joints 2b, 3b. At the other free ends of the caliper lever 2, 3 is in the brake caliper unit 1 after 1 the brake cylinder 8 with the integrated adjuster module 9 in coupling axes of coupling points 6, 7 articulated. For the compact brake caliper unit 1' 2 only the adjuster module 9 is articulated at the coupling points 6, 7.

The brake cylinder 8 can, for example, be pneumatic, hydraulic, electromechanical or the like. be driven. The brake pads 4, 5 are arranged on both sides of a brake disc, not shown here.

During a braking process, the brake cylinder 8 is activated when the brake is applied and increases a distance 10 in the y-direction between the coupling points 6, 7. This results in the brake pads 4, 5 moving towards one another in the y-direction and thus being pressed against the brake disc will.

When the brake is released, the brake cylinder 8 is not actuated, the distance 10 between the coupling points 6, 7 decreases again in the y-direction, and the brake linings 4, 5 move away from one another. The brake pads 4, 5 are detached from the brake disc.

The use of the adjuster module 9 ensures that the brake pad play, which is also referred to as the clearance, is kept constant during the period of operation when the brake is released. The clearance is between a brake pad 4, 5 and the brake disc.

During operation of the brake, the wear of the brake pads 4, 5 and the brake disc increases and causes the distance 10 between the coupling points 6, 7 to increase, with a distance in the y-direction between the brake pads 4, 5 decreasing during the braking process .

In this way, the distance 10 forms a measure of the wear of the brake pads 4, 5 and the brake disc. A dynamic change in distance 10 during braking can also provide information about the function of the braking process.

3 shows a schematic sectional view of a brake caliper unit 1' according to the invention with a first exemplary embodiment of a wear sensor device 11 according to the invention 4 15 is a schematic enlarged sectional view of a sensor case 15 in FIG 3 shown.

The sectional view shows the view of the brake caliper unit 1' in the x-direction (cf. 2 ).

The brake caliper unit 1' according to the invention also includes the wear sensor device 11.

The wear sensor device 11 is here parallel to the adjuster module 9 between the axes of the coupling points 6, 7 at two points, namely in the coupling points 6, 7 on the caliper levers 2, 3 attached. This means that a sensor axis 11a of the wear sensor device 11 runs parallel to an axis 9a of the adjuster module 9. A movement of the caliper levers 2, 3 during braking processes with an associated change in the distance 10 is transmitted to the wear sensor device 11 via the coupling points 6, 7.

In the first exemplary embodiment, the wear sensor device 11 comprises an evaluation unit 12, fastening elements 13 and 14, a sensor housing 15, a housing 16, a movement conversion unit with a threaded tube 17 and a threaded spindle 18, a bellows 20, at least one bearing 21 and at least one sensor element 24, 24'.

The evaluation unit 12 is connected to the at least one sensor element 24, 24' via a connecting path 12a, e.g. an electrical and/or optical transmission line. It is also conceivable that a wireless transmission path, e.g. radio, infrared, ultrasonic, can be used instead of a wired connection path 12a.

The wear sensor device 11 is fastened to the tong levers 2, 3 in the coupling points 6, 7 by means of the fastening elements 13, 14, which are designed here as fastening brackets. This is further described below.

A change in the distance 10 between the coupling points 6 , 7 is transmitted to the wear sensor device 11 via the fastening elements 13 , 14 . During braking, the coupling points 6, 7 each move on an arc of a circle, the center point of which is the axis of the respective joint 2a, 3a of the respective caliper lever 2, 3. The axes of the coupling points 6, 7 and the joints 2a, 3a run parallel to one another in the z-direction. The fastening elements 13, 14 allow a linear movement of the wear sensor device 11 in the y-direction.

The sensor housing 15 serves to accommodate the at least one sensor element 24. The sensor housing 15 has a peripheral wall 15a, which is closed with an end plate 15b. The end plate 15b and the wall 15a define an inner space 15c, the opening 15d of which is provided with a circumferential collar 15e projecting radially outwards.

The sensor housing 15 is fastened with its peripheral collar 15e to a fastening plate 13a of the first fastening element 13 and is sealed off from the atmosphere with a seal 15f, e.g. an O-ring. The first fastening element 13 thus forms the attachment of the wear sensor device 11 to the coupling point 6 of the first caliper lever 2.

In addition, the sensor housing 15 is connected to a bearing housing 16a of the housing 16 via the fastening plate 13a. The bearing housing 16a is fastened with a shoulder 16c in an opening 13b of the fastening plate 13a. The housing 16 also has a housing tube 16b. Sensor housing 15, bearing housing 16a and housing tube 16b are arranged one behind the other coaxially to sensor axis 11a.

A possibility is shown here by way of example, in which the housing tube 16b extends almost completely over the entire length of the distance 10 between the coupling points 6 and 7 . Of course, the length of the housing tube 16b can also have other dimensions. The housing tube 16b and a threaded tube 17 are here arranged together telescopically, with the housing tube 16b being pushed onto the threaded tube 17. The threaded tube 17 has an internal thread 19 and a smooth outer surface.

A free end 17a of the threaded tube 17 is located in the 3 shown initial position of the wear sensor device 11 at a small distance from the bearing housing 16a. The other end 17b of the threaded tube 17 is formed as a flange with which the threaded tube 17 is attached to a mounting plate 14a of the second mounting member 14. The second fastening element 14 forms a further attachment of the wearing device 11 to the coupling point 7 of the second caliper lever 3.

The motion conversion unit includes the lead screw 18 with an external thread 19 and the threaded tube 17 with an internal thread 19a. In this example, the internal thread 19a is formed in a portion of the free end 17a of the threaded tube 17. The threaded spindle 18 is arranged in the threaded tube 17, the external thread 19 of the threaded spindle 18 being in engagement with the internal thread 19a of the threaded tube 17. The external thread 19 and the internal thread 19a here form a movement thread with a corresponding pitch.

The threaded spindle 18 is arranged in the threaded tube 17 in such a way that a first spindle end 18a protrudes from the threaded tube 17 in the direction of the bearing housing 16a. A second, free spindle end 18b is still arranged inside the end 17b of the housing tube 17 in the starting position of the wear sensor device 11 .

The first spindle end 18a of the threaded spindle 18 is connected to a bearing section 18c. A bearing 21, here e.g. The bearing 21 forms a rotary bearing for the threaded spindle 18 about the sensor axis 11a.

The end 17b of the threaded tube 17 is attached to the fastening plate 14a of the fastening element 14 so that it cannot rotate.

A seal is fitted over the housing tube 16b and the portion of the threaded tube 17 protruding therefrom with the end 17b. This seal is here a bellows 20 which is fastened to the housing tube 16b with a first sealing end section 20a in the region of the connection between the bearing housing 16a and the housing tube 16b. A second sealing end portion 20b is fixed to the end 17b portion of the threaded tube 17 .

The bearing section 18c of the threaded spindle 18 is also coupled to the sensor element 24 via a gear 23 by means of a rotary connection. The gear 23 can be a planetary gear, for example. The sensor element 24 detects an angle of rotation of the threaded spindle 18 about the sensor axis 11a. The sensor element 24 is a rotation angle sensor, for example with a potentiometer or with Hall sensors. Of course, optical and/or capacitive angle sensors are also possible.

The movement of the caliper levers 2, 3 during a braking process causes a change in the distance 10, which is transmitted to the wear sensor device 11 as a longitudinal movement. The wear sensor device 11 is telescopically pulled apart and pushed together again. Since the threaded tube 17 of the movement conversion unit is non-rotatably attached to the second fastening element 14, when the distance 10 changes in length, the threaded spindle 18 is rotated due to the movement thread, which is formed from the external thread 19 of the threaded spindle 18 engaging with the internal thread 19a of the threaded tube 17. the threaded spindle 18 is rotated about the sensor axis 11a. In this way, the motion converting unit converts the longitudinal motion of changing the distance 10 into a rotary motion.

The sensor element 24 is then rotated via the rotary connection 22 and thus detects the angle of rotation, which is proportional to the change in length of the distance 10 . The evaluation unit 12 determines the wear values of the brake linings 4, 5 and the brake disk from the signals transmitted for this purpose by the sensor element 24. In addition, the evaluation unit 12 can monitor the braking process on the basis of the recorded change in length of the distance 10 caused by the movement, e.g. by comparison with previously specified values.

An evaluation of the signals is explained in more detail below in connection with 7 explained.

5 12 shows a sectional view of a variation of the first exemplary embodiment of the wear sensor device 11. FIG 3 .

The wear sensor device 11' in the variation according to FIG 5 differs from the first embodiment of the wear sensor device 11 after 3 in the shape of the housing 16, in the arrangement of the internal thread 19a in the other end 17b of the threaded tube 17 and in the arrangement of the threaded tube 17 and the threaded spindle 18.

The bearing housing 16a is fixed in an opening of an intermediate plate 16d via the step 16c. The intermediate plate 16d is attached to the attachment plate 13a and has a shoulder in the opening 13b of the attachment plate 13a of the attachment element 13. The sensor housing 15 is in turn attached to the attachment plate 13a with its peripheral collar 15e and sealed with the seal 15f from the atmosphere.

The bearing housing 16a has the bearing 21 which, in contrast to the first exemplary embodiment, is arranged with its inner ring on the end 17a of the threaded tube 17. In this variant, the threaded tube 17 is rotatably mounted with the bearing 21 .

A length of the housing tube 16b is about a quarter of the length of the threaded tube 17. The threaded tube 17 extends over the entire length of the threaded spindle 18.

In this variant, the threaded spindle 18 is non-rotatably attached via a bracket 18 to the fastening plate 14a of the second fastening element 14 by means of a retaining plate 18e.

The bellows 20 is on the housing tube 16b with the first sealing end portion 20a and with the second sealing end portion 20b attached to the holder 18d of the threaded spindle 18.

In contrast to the first exemplary embodiment, in this variant the rotary connection 22 to the gear 23 of the sensor element 24 is connected to the rotatable threaded tube 17 via a driver 22a. The driver 22a is inserted into a bore of the first end 17a of the threaded tube 17 and is non-rotatably connected to the threaded tube 17, e.g. screwed in, clamped in or the like.

The movement of the caliper levers 2, 3 during a braking process causes a change in the distance 10, which is transmitted to the wear sensor device 11. This is telescopically pulled apart or pushed together again. By means of the motion thread (external thread 19 of the threaded spindle 18 and internal thread 19a of the threaded tube 17), this longitudinal movement is converted here into a rotational movement of the threaded tube 17 and transmitted to the sensor element 24.

In 6 12 is a sectional view of a second embodiment of the wear sensing device 11 according to FIG 3 shown.

The wear sensor device 11" according to the second exemplary embodiment in 6 includes the fasteners 13, 14, the bellows 20, a housing tube 25 and a contactless distance measuring sensor.

The contactless distance measuring sensor is attached to the second fastening element 14 by means of a holder 26 and has at least one sensor element 24'.

The contactless distance measuring sensor interacts with a reference section of the wear sensor device 11" and detects a distance 10' between the sensor element 24' and the reference section. A change in the distance 10' corresponds to a change in the distance 10 between the coupling points 6, 7. It is also It is possible that a change in the distance 10' is proportional to a change in the distance 10 between the coupling points 6, 7. The real distance or the associated wear is calculated by the evaluation unit 12.

The housing tube 25 is fastened with a tube end 25a in a recess 13c in the fastening plate 13a of the first fastening element 13 . The recess 13c is closed by a wall 13d. The pipe end 25a rests against an inner side 13e of this wall 13d.

The housing tube 25 extends over a length of approximately two thirds of the distance in the y-direction between the mounting plate 13a of the first mounting element 13 and the mounting plate 14a of the second mounting element 14 and has a free tube end 25b.

The bracket 26 is attached to the attachment plate 14a of the second attachment element 14 with an attachment end 26a coaxially to the housing tube 25 and the sensor axis 11a. The mount 26 is designed as a tube which protrudes from the mount plate 14a with a free mount end 26b into the space between the mount plate 13a of the first mount element 13 and the mount plate 14a of the second mount element 14 . The free mounting end 26b protrudes into the second end 25b of the housing tube 25 in the initial position of the wear sensor device 11 ′ shown here.

A rod-shaped sensor housing 27 is inserted into the holder 26 through the free holder end 26b with a likewise rod-shaped fastening section 27a. An insertion depth can be adjusted by an adjustable stop element 27b of the sensor housing 27 .

The sensor element 24 ′ is arranged in the section of the sensor housing 27 which protrudes into the housing tube 25 . The housing tube 25 and the sensor housing 27 with the sensor element 24' on the holder 26 are arranged telescopically. In other words, the housing tube 25 and the non-contact distance measuring sensor are telescoped together

The sensor element 24 ′ is an ultrasonic sensor here, which interacts with the inside 13e of the wall 13d of the recess 13b in the fastening plate 13a of the first fastening element 13 . The inner side 13e of the wall 13d as a reflection surface for the ultrasonic vibrations of the sensor element 24' forms the reference section of the wear sensor device 11". A transmitter/receiver surface 24'a of the sensor element 24' and the inner side 13e of the wall 13d are arranged at a distance of 10' A change in this distance 10' is a measure of a change in the distance 10 between the coupling points 6 and 7. In this way, the wear sensor device 11'' with the ultrasonic sensor as the sensor element 24' can detect the changes in the distance 10.

The bellows 20 is with its first sealing end section 20a in the region of the first tube end 25a of the housing tube 25 and with its second sealing end section 20b in the region of the Attachment end 26a of the bracket 26 attached. The tube end 25a is designed here as a thickened collar.

The movement of the caliper levers 2, 3 during a braking process causes a change in the distance 10, which is transmitted to the wear sensor device 11''. This is telescopically pulled apart and pushed back together again. This increases the distance 10' between the transmitter/receiver surface 24'. a of the sensor element 24' and the inside 13e of the wall 13d changes in the same way as the distance 10. This change is detected by means of the ultrasonic sensor with the sensor element 24'.

The ultrasonic sensor with the sensor element 24' forms the contactless distance measuring sensor. The connecting section 12a, e.g. an electrical line for power supply and signal transmission, is connected to the evaluation unit 12.

In one embodiment, instead of a contactless distance measuring sensor, a contact-type distance measuring sensor with at least one electromechanical contact can also be provided. This contact is then closed or opened, depending on the contact design, whether it is a normally open or normally closed contact, when a distance is reached that corresponds to a certain, e.g. maximum, wear value.

However, such a contact can also be arranged in another embodiment as an electromechanical contact in the sensor housing 27, with this contact being actuated by an actuator at a previously set distance which corresponds to the determined wear value. Such an electromechanical contact can be a so-called snap switch, microswitch or limit switch, for example.

Several contacts can also be provided, which are assigned to different levels of wear, e.g is possible.

The actuator can be, for example, a rod firmly connected to the tube 25 or a switch cam arranged on the inside of the tube 25 .

Such a mechanical contact can also be provided as an additional, redundant component.

7 represents a schematic diagram SB of wear graphs of the brake caliper unit 1, 1'.

The measurement signal S of one or more sensor elements 24, 24' of the wear sensor device 11, 11', 11" of the brake caliper unit 1, 1' is plotted as a function of time t. The measurement signal S is received by the evaluation unit 12, amplified and evaluated. Evaluation results are forwarded by the evaluation unit 12 to suitable display, data processing and storage devices.

The measurement signal S shows the changes in the distance 10 and corresponds to the sum of the wear on the brake pads 4, 5, the brake disc and the clearance.

A pad wear graph 28 runs like a triangular function, increasing up to a maximum wear value of pad wear 29, at which pad change 30 of the brake pads 4, 5 then takes place.

A disk wear graph 31 has an elongated sawtooth profile. Changing the brake disc as a disc change 32 is only necessary after a number of pad changes 30 when there is maximum disc wear 33 .

Total wear 34 includes the sum of pad wear 29 and disc wear 33.

The form of the measurement signal 3 of the brake lining wear 31 is also a sawtooth profile, but the brake linings 4, 5 have to be changed more frequently than the brake disc.

By means of the continuous detection of the measurement signal according to the wear, a constant monitoring of the wear for special features and such events as premature or abnormal wear can be quickly determined.

In 8th 1 is a schematic flow chart of an exemplary embodiment of a method according to the invention for detecting wear of brake pads 4, 5 and brake disc of the brake caliper unit 1, 1'.

In a first method step VS1, the initial position and the changes in the distance 10 between the coupling points 6, 7 of the caliper levers 2, 3 during braking processes are recorded with at least one wear sensor device 11, 11', 11".

The at least one wear sensor device 11, 11' is a rotation angle sensor and detects changes in rotation angle proportional to length changes in the distance 10 between the coupling points 6, 7 of the tong levers 2, 3.

The at least one wear sensor device 11" can also have a contactless distance measuring sensor that detects changes in length of a distance 10' between a sensor element 24' of the contactless distance measuring sensor and a reference section of the wear sensor device 11".

The sensor element 24' is an ultrasonic sensor here, which interacts with the inside 13e of the wall 13d of a recess 13b in the fastening plate 13a of the first fastening element 13, in which the housing tube 25 is fastened. The inner side 13e of the wall 13d as a reflection surface for the ultrasonic vibrations of the sensor element 24' forms the reference section of the wear sensor device 11". A transmitter/receiver surface 24'a of the sensor element 24' and the inner side 13e of the wall 13d are arranged at a distance of 10' A change in this distance 10' is a measure of a change in the distance 10 between the coupling points 6 and 7.

In a second method step VS2, the at least one wear sensor device 11, 11', 11" generates measurement signals S based on the measured values recorded and forwards them to an evaluation unit 12.

In a third method step VS3, the evaluation unit 12 evaluates the measurement signals S in such a way that the wear values for lining wear and disc wear of the brake caliper unit 1 summed up in the measurement signals S are determined.

The wear values are then compared with previously stored limit values for changing pads and discs. According to the comparison results, advertisements, warnings, etc. are issued on suitable media.

In addition, the measurement signals can be evaluated in such a way that information about the route or the sine curve, which continuously deflects the train wheel set from its starting position, is determined.

With an arrangement of two or more wear sensor devices 11, 11′, 11″, their measurement signals can be used to check the plausibility of the determined wear values.

In addition, the measurement signals supplied by the wear sensor devices 11, 11′, 11″ can also be used to detect the loss of a brake pad 4, 5 and/or to check whether the brake caliper unit 1, 1′ is actuated or released.

The evaluation unit 12 can also use comparison values to determine wear of the entire brake caliper unit 1, 1′ from all of the measured values recorded and the wear values determined from them.

The wear sensor devices 11, 11', 11" can be found on the conventional brake caliper unit 1 1 as well as the so-called compact brake caliper unit 1' 2 to be appropriate. It is also possible to retrofit both brake caliper units 1, 1'.

The invention is not limited by the embodiment given above, but can be modified within the scope of the claims.

For example, it is conceivable that instead of the ultrasonic sensor in the second exemplary embodiment, a radar sensor and/or an optical distance measuring sensor, e.g. an infrared distance sensor, can be used.

Another alternative is to adapt the depth measurement solution of a vernier caliper.

Reference List

1

brake caliper unit

2, 3

pincer lever

2a, 3a; 2b, 3b

joint

4, 5

brake pad

6, 7

coupling axis

8th

brake cylinder

9

adjuster module

10, 10'

Distance

11, 11', 11"

wear sensor device

11a

sensor axis

12

evaluation unit

12a

connection line

13, 14

fastener

13a, 14a

mounting plate

13b

opening

13c

recess

13d

Wall

13e

inside

15

sensor housing

15a

Wall

15b

faceplate

15c

inner space

15d

opening

15e

collar

15f

poetry

16

Housing

16a

bearing housing

16b

housing tube

16c

Unit volume

16d

intermediate plate

17

threaded pipe

17a, 17b

End

18

lead screw

18a, 18b

spindle end

18c

storage section

18d

bracket

18d

bearing plate

18e

Retaining plate

19

external thread

19a

inner thread

20

bellows

20a, 20b

seal end section

21

warehouse

22

Slewing Ring

22a

driver

23

transmission

24, 24'

sensor element

24'a

transmitter/receiver area

25

Pipe

25a, 25b

pipe end

26

bracket

26a

fastening end

26b

bracket end

27

sensor housing

27a

attachment section

28

pad wear graph

29

lining wear

30

pad change

31

disc wear graph

32

disc change

33

disc wear

34

total wear

S

measurement signal

SB

graph

t

time

VS1, VS2, VS3

process step

x, y, z

coordinates

QUOTES INCLUDED IN DESCRIPTION

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Patent Literature Cited

• WO 2018/178018 A1 [0004]

Claims (18)

Brake caliper unit (1, 1') of a disc brake, in particular for rail vehicles, having two caliper levers (2, 3), a brake cylinder (8), an adjuster module (9), brake linings (4, 5) and a wear sensor device (11, 11', 11") with at least one sensor element (24, 24') and an evaluation unit (12), characterized in that the wear sensor device (11, 11', 11") is installed parallel to the adjuster module (9) and/or the brake cylinder (8) is articulated between the two caliper levers (2, 3) on these in coupling axes. brake caliper unit (1, 1'). claim 1 , characterized in that the wear sensor device (11, 11', 11") is articulated in coupling axes of coupling points (6, 7) in which the brake cylinder (8) and/or the adjuster module (9) is/are articulated, the coupling points (6, 7) being arranged at a distance (10) from one another. Brake caliper unit (1, 1') according to one of the preceding claims, characterized in that the wear sensor device (11, 11') has a movement conversion unit which converts a longitudinal movement as a change in the distance (10) of the coupling points (6, 7) into a rotary movement . brake caliper unit (1, 1'). claim 3 , characterized in that the movement conversion unit of the wear sensor device (11, 11 ') has a threaded tube (17) with an internal thread (19a) and a threaded spindle (18) with an external thread (19), wherein the internal thread (19a) and the external thread ( 19) are engaged and form a movement thread. brake caliper unit (1, 1'). claim 4 , characterized in that the threaded tube (17) is non-rotatably connected to the wear sensor device (11, 11') and the threaded spindle (18) is rotatably mounted and coupled to the at least one sensor element (24), or the threaded spindle (18) is non-rotatably connected to the wear sensor device (11, 11') and wherein the threaded tube (17) is rotatably mounted and coupled to the at least one sensor element (24). Brake caliper unit (1, 1') according to 5, characterized in that the at least one sensor element (24) is a rotary angle sensor. Brake caliper unit (1, 1 ') according to one of claims 3 until 6 , characterized in that the wear sensor device (11, 11') comprises fastening elements (13; 14), a sensor housing (15), a housing (16), the movement conversion unit and the at least one sensor element (24), the wear sensor device (11, 11') is attached in an articulated manner, each with a fastening element (13; 14) in the coupling axes of the coupling points (6, 7). brake caliper unit (1, 1'). claim 7 , characterized in that the wear sensor device (11, 11 ') also comprises at least one bearing (21) which forms a rotary bearing of the threaded spindle (18) or the threaded tube (17). brake caliper unit (1, 1'). claim 7 or 8th , characterized in that the housing tube (16b) and the threaded tube (17) are arranged together telescopically, the housing tube (16b) being pushed onto the threaded tube (17). brake caliper unit (1, 1'). claim 2 , characterized in that the wear sensor unit (11") has at least one contact-type or at least one contactless distance-measuring sensor. brake caliper unit (1, 1'). claim 10 , characterized in that the at least one contactless distance measuring sensor is an ultrasonic sensor, a radar sensor and/or an optical distance measuring sensor. brake caliper unit (1, 1'). claim 11 , characterized in that the wear sensor device (11'') has fastening elements (13, 14), a housing tube (25) and the at least one contactless distance measuring sensor, the housing tube (25) and the at least one contactless distance measuring sensor being arranged together in a telescopic manner. Brake caliper unit (1, 1 ') according to one of Claims 10 until 12 , characterized in that the at least one contactless distance measuring sensor interacts with a reference section of the wear sensor device (11") and a distance (10') between the sensor element (24') and the reference section as a measure of a change in the distance (10) between the coupling points ( 6, 7) recorded. Brake caliper unit (1, 1') according to one of the preceding claims, characterized in that the brake caliper unit (1, 1') is designed for a pneumatic disc brake. Method for determining wear of brake pads (4, 5) and brake disc of a brake caliper unit (1, 1') of a disc brake, in particular for rail vehicles, having two caliper levers (2, 3), a brake cylinder (8), brake linings (4, 5) and a wear sensor device (11, 11', 11") with an evaluation unit (12), characterized by the method steps (VS1 ) Detection of an initial position and detection of changes in length of a distance (10) from coupling points (6, 7) of the two caliper levers (2, 3) during braking processes with the wear sensor device (11, 11', 11''), with a conversion of the changes in length of the distance (10) by means of a movement conversion device in changes in the angle of rotation of a rotary angle sensor, or the changes in length of the distance (10) are detected by measuring a distance (10') between a sensor element (24') of a contact-based and/or contactless distance measuring sensor and a reference section of the wear sensor device (11"); (VS2) generating measurement signals (S) on the basis of the measurement values recorded in this way; and forwarding the measurement signals to an evaluation unit (12); (VS3) Evaluation of the measurement signals (S) by the evaluation unit (12) in such a way that the wear values for lining wear and disc wear of the brake caliper unit (1, 1') summed up in the measurement signals (S) are determined. procedure after claim 15 , characterized in that the contactless distance measuring sensor is an ultrasonic sensor, a radar sensor and/or an optical distance measuring sensor. Procedure according to one of Claims 15 or 16 , characterized in that the evaluation unit (12) compares the determined wear values with previously stored limit values for changing pads and discs and outputs displays, warnings, etc. on suitable media in accordance with the comparison results. Procedure according to one of Claims 15 until 17 , characterized in that the evaluation unit (12) determines wear of brake pads (4, 5) and brake disc (13, 13') of the entire disc brake from all of the measured values recorded and wear values determined therefrom using comparative values.

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