Measuring device for monitoring a disc brake for a vehicle, in particular a commercial vehicle, disc brake, measuring arrangement, vehicle, in particular a commercial vehicle

Abstract

Measuring device (100) for monitoring a disc brake (250) for a vehicle (200a), in particular a commercial vehicle (200b), comprising: a carrier (110) for movably arranging a brake caliper (240) of the disc brake (250); and an optical fiber (120) for coupling in and coupling out light (121); characterized in that the carrier (110) has a dedicated receiving section (117) for attaching the optical fiber (120) to the carrier (110).

Description

[0001] The disclosure relates to a measuring device for monitoring a disc brake for a vehicle, in particular a commercial vehicle. The disclosure also relates to a disc brake, a measuring arrangement, and a vehicle, in particular a commercial vehicle.

[0002] The vehicle, especially a commercial vehicle, is also referred to as a "vehicle" in the following. Such measuring devices, disc brakes, and vehicles are known in the art. The disc brake is designed to generate a braking torque to decelerate the vehicle. The braking torque is an indicator of the brake's functionality.

[0003] Damage and / or deformation of a disc brake or a vehicle's braking system can lead to a change in braking torque and can have various causes, such as overheating, loose connecting parts, wear, improper assembly, temperature-induced cracks, contamination, etc. Monitoring the braking torque and / or possible damage and / or deformation can therefore have an impact on driving safety, the possible driving time, an improvement in design methods and / or an improvement in the cost-effectiveness of operating the vehicle, for example to enable and / or improve predictive maintenance and diagnostics.

[0004] It is known in the art to provide a plurality of sensors for different parameters. Typically, multiple sensors are provided to detect the various parameters that may be a cause of damage and / or deformation. Furthermore, there may be influences such as high temperatures, chemical substances and / or electrical currents or electromagnetic fields and / or interference that make the use of different sensor types impossible and / or difficult.

[0005] It is known to use fiber optic sensors to measure multiple parameters.

[0006] US 2022 / 252121 A1 discloses a method for detecting and measuring a braking force and / or a braking torque resulting from the actuation of a vehicle braking system.The method comprises: installing a fiber optic strain sensor of the fiber Bragg grating type at a corresponding position in a material portion of the body of the brake caliper that is deformable, detecting a local deformation and / or stress acting in the respective position by the fiber optic strain sensor, generating a corresponding first photonic signal representative of the detected deformation and / or strain, receiving the first photonic signal by an optical read / interrogation unit optically connected to the fiber optic strain sensor and generating, by the optical read / interrogation unit, a first electrical signal representative of the locally detected deformation and / or strain based on the received first photonic signal, and processing the first electrical signal to obtain a measurement of the braking force and / or braking torque.

[0007] A similar method is disclosed with reference to a brake pad: US 2022 / 299082 A1 discloses a method for detecting and measuring a clamping force and / or a braking torque. The method comprises encapsulating a fiber optic strain sensor in a housing and incorporating the housing into a portion of the friction material adhered to a base platform of a brake pad.

[0008] By encapsulating and / or integrating the fiber optic strain sensor into the brake caliper and / or brake pad, it is primarily possible to measure the clamping force resulting from the application of the brake pads over the disc brake. However, the braking torque resulting from the application is influenced by a friction factor and cannot be determined directly and / or only partially.

[0009] Furthermore, US 2022 / 242383 A1 discloses a method for determining a braking torque at at least one mounting interface between a brake caliper body and a brake caliper carrier. The method comprises inserting at least one washer device at the at least one mounting interface, wherein the washer device comprises at least one fiber-optic strain sensor of the fiber Bragg grating type, which, through the at least one fiber-optic strain sensor, detects a local deformation and / or strain acting in a corresponding detection position and generates at least one corresponding photonic signal, and which represents the detected deformation and / or strain. The brake caliper can be a fixed caliper or a floating caliper.

[0010] However, the arrangement of the washer device, for example, may be ambiguous and / or exhibit play, which can influence the measurement results. Furthermore, the washer device may directly detect deformation and / or strain of the washer device alone, but not of the brake caliper and / or the brake caliper carrier.

[0011] The disclosure is based on the object of enriching the state of the art and improving aspects of the prior art. In particular, the disclosure solves the problem of enabling improved and more reliable monitoring of the disc brake.

[0012] The problem is solved by a method according to claim 1 and the subject matter according to the further independent claims. The subclaims specify further developments of the disclosure.

[0013] According to one aspect of the disclosure, a measuring device for monitoring a disc brake for a vehicle, in particular a commercial vehicle, is provided, comprising: a carrier for movably arranging a brake caliper of the disc brake; and an optical fiber for coupling in and out of light; characterized in that the carrier has a dedicated receiving portion for fastening the optical fiber to the carrier.

[0014] The brake caliper can, for example, be movable relative to the carrier. The brake caliper can thus be a floating and / or a floating caliper. The brake caliper can apply brake pads via a disc brake. The resulting braking torque is transmitted via the carrier supporting the brake caliper.

[0015] It was recognized that a precise and reliable measurement of an effect, such as a deformation, of the braking torque on the carrier can be measured. For this purpose, the carrier has a dedicated receiving section. The receiving section is designed so that the optical fiber is attached to the carrier in order to directly determine the effect of the braking torque on the carrier. The carrier is subject to comparatively little vibration and, unlike the brake caliper, remains stationary when the brake is applied. This means that the receiving section and thus the optical fiber can also remain stationary, which minimizes any influence on the measurement result due to the movement of the brake caliper during application. This can prevent the measurement from being influenced, for example by play in a washer, due to the movement of the brake caliper during application.

[0016] The disclosure enables various sensors to be replaced by a single light sensor, providing real-time monitoring of the disc brake to perform predictive diagnostics and / or schedule maintenance. This allows the number of physically installed sensors to be reduced from a plurality of sensors to a single light sensor, while simultaneously increasing the variety of detectable parameters. An optical fiber, and in particular an optical fiber based on fiber optics, can overcome the limitations of other sensors and offers a comparatively small size, resistance to electromagnetic radiation, and corrosion resistance, as well as the ability to operate under specific environmental conditions.

[0017] Real-time diagnostics as on-board diagnostics of the disc brake and thus also of the brake caliper enable early detection of defects and / or errors in order to plan maintenance and / or repairs, for example, and to avoid disc brake failure while driving.

[0018] Optionally, the carrier has a surface as a receiving section, and the measuring device has an optical fiber carrier that encompasses the optical fiber and is attached to the surface. The optical fiber carrier is configured to be attached to the surface of the carrier in order to secure the optical fiber to the carrier. The optical fiber carrier can, for example, be a plate and / or be metallic.

[0019] Optionally, the carrier and the optical fiber carrier are integrally bonded to one another and / or the carrier and the optical fiber carrier are connected by connecting elements. The carrier and the optical fiber carrier can be bonded and / or welded together as a material-to-material connection. This creates a flat, effective connection between the carrier and the optical fiber carrier. The carrier and the optical fiber carrier can be connected to one another using screws, for example, as connecting elements, to easily attach and / or detach the optical fiber carrier to the carrier.

[0020] Optionally, the carrier has a recess as a receiving section for arranging the optical fiber, and the optical fiber is arranged in the recess. This allows the optical fiber to be connected directly to the carrier. The recess allows the optical fiber to be integrated into the carrier in a space-efficient manner.

[0021] Optionally, the recess features an opening located on the vehicle side when installed. This allows the fiber optic cable to be routed out of the recess on the vehicle side, enabling effective connection of the fiber optic cable to a light source and / or a light sensor.

[0022] Optionally, the optical fiber is arranged two- and / or three-dimensionally. It was recognized that a multi-dimensional arrangement of the optical fiber enables measurement by deformation and / or torsion. For example, the optical fiber can follow a sinusoidal or serpentine curve, and / or a meandering curve. The optical fiber can be arranged in a plane and / or follow a contour of the surface of the carrier. For the same reason, the optical fiber optionally has a first leg and a second leg, wherein the first leg and the second leg are each arranged to extend coaxially with respect to a rotational axis of a brake disc of the disc brake.

[0023] Optionally, the optical fiber has a circular cross-section. This allows for isotropic light transmission within the fiber. This allows measurement values ​​to be recorded regardless of the fiber's orientation.

[0024] Optionally, the optical fiber comprises a core and a cladding layer surrounding the core. This can, for example, improve the optical fiber's resistance to chemical, mechanical, and thermal influences. In another embodiment, a cladding layer may be omitted to provide a simple and cost-effective optical fiber.

[0025] Optionally, the optical fiber is a fiber optic component comprising a fiber Bragg grating. This allows the fiber optic component to be used as a known component, enabling reliable measurement.

[0026] According to one aspect of the disclosure, a disc brake is provided. The disc brake comprises a measuring device described above with a carrier, a brake caliper movably arranged on the carrier, a brake disc, and brake pads that can be applied over the brake disc. Optionally, the measuring device of the disc brake has one or more of the optional and / or advantageous features described above with reference to the measuring device in order to achieve an associated technical effect.

[0027] According to one aspect, a disc brake assembly is provided. The disc brake assembly comprises a measuring device as described above, having a carrier, and a brake caliper movably mounted on the carrier. Optionally, the measuring device of the disc brake assembly has one or more of the optional and / or advantageous features described above with reference to the measuring device in order to achieve an associated technical effect.

[0028] According to one aspect of the disclosure, a measuring arrangement is provided, comprising: a measuring device as described above and / or a disc brake as described above; a light source for coupling light into the optical fiber; a light sensor for detecting light coupled out of the optical fiber; and a data processing device for evaluating data relating to the light. Optionally, the measuring device of the measuring arrangement comprises one or more of the optional and / or advantageous features described above with reference to the measuring device in order to achieve an associated technical effect.

[0029] Optionally, the optical fiber has a connector end for connecting the light source and the light sensor. This provides an effective connection between the optical fiber and the light source and the light sensor. This enables effective measurement, particularly in the case of a fiber optic component comprising a fiber Bragg grating.

[0030] Optionally, the data processing device is configured to process a phase shift, intensity change, polarization change, wavelength change, and / or frequency change relating to the light as data relating to the light. It has been recognized that various influences, in particular mechanical and thermal influences on the carrier, can influence various properties of the light propagating in the optical waveguide.

[0031] Optionally, the data processing device is configured to calculate a braking torque based on the data relating to the light. It was discovered that, due to the well-defined geometry of the carrier and the way the optical fiber is attached to the carrier, the braking torque can be determined from the data. For this purpose, the measuring setup can be calibrated to determine a correlation between the data and the braking torque.

[0032] According to one aspect of the disclosure, a vehicle, in particular a commercial vehicle, is provided, comprising a measuring device and / or a measuring arrangement described above. Optionally, the measuring device and / or the measuring arrangement comprises one or more of the optional and / or advantageous features described above with reference to the measuring device and / or the measuring arrangement in order to achieve an associated technical effect.

[0033] Further features of the disclosure as well as its technical effects emerge from the figures and the description of the preferred embodiments shown in the figures. Fig. 1 a schematic representation of a vehicle, in particular a commercial vehicle, according to one aspect of the disclosure; Fig. 2 is a schematic representation of a measuring device according to one aspect of the disclosure; Fig. 3 is a schematic representation of an optical waveguide of a measuring device according to one aspect of the disclosure; Fig. 4 is a schematic representation of an optical waveguide of a measuring device according to one aspect of the disclosure; Fig. 5 is a perspective view of a detail of a carrier of a measuring device according to one aspect of the disclosure; Fig. 6 is a schematic representation of a first perspective view of an optical waveguide carrier with an optical waveguide of a measuring device according to one aspect of the disclosure; and Fig. 7 is a schematic representation of a second perspective view of an optical waveguide carrier of a measuring device according to one aspect of the disclosure.

[0034] Fig. 1 shows a schematic representation of a vehicle 200a, in particular commercial vehicle 200b, according to one aspect of the disclosure.

[0035] Vehicle 200a, in particular commercial vehicle 200b, is referred to below as vehicle 200a, 200b. Vehicle 200a, 200b is a land vehicle. Vehicle 200a, 200b is a towing vehicle and / or a trailer of a multi-unit vehicle or vehicle combination, a single-unit vehicle, and / or a bus.

[0036] The vehicle 200a, 200b includes a disc brake 250. The disc brake 250 includes a brake caliper 240, a brake disc 255, a carrier 110 supporting the brake caliper 240, and brake pads 160 (see Fig. 2). The disc brake 250 is configured to apply the brake pads 160 hydraulically, pneumatically, and / or electrically via the brake disc 255. The disc brake 250 can thereby produce a braking torque T that can decelerate the movement of the vehicle 200a, 200b.

[0037] The carrier 110 is fixedly connected to the vehicle 200a, 200b, for example, to a wheel carrier. The brake caliper 240 is movably mounted on the carrier 110. For example, the disc brake 225 has a rotation axis A, and the brake caliper 240 is slidably mounted on the carrier 110 parallel to the axis A.

[0038] The vehicle 200a, 200b comprises a measuring arrangement 150. The measuring arrangement comprises a measuring device 100. The measuring device 100 comprises the carrier 110 for movably arranging the brake caliper 240 and an optical fiber 120 for coupling and decoupling light 121.

[0039] The carrier 110 has a dedicated receiving portion 117 for attaching the optical waveguide 120 to the carrier 110. The receiving portion 117 is further described with reference to Fig. 2 to 7.

[0040] As shown schematically in Fig. As illustrated in Figure 1, the optical waveguide 120 is a fiber optic component 120" and includes a fiber Bragg grating 120'. The optical waveguide 120 as a fiber optic component 120" thus includes one or more optical fibers, for example, glass fibers. The fiber Bragg grating 120' is an example of an optical interference filter configured to reflect light 121 having wavelengths within a filter bandwidth.

[0041] The measuring arrangement 150 further comprises a light source 151 for coupling light 121 into the optical waveguide 120, a light sensor 152 for detecting light 121 coupled out of the optical waveguide 120, and a data processing device 155 for evaluating data 156 relating to the light 121.

[0042] The light source 151 is configured to receive a control signal 157 from the data processing device 155. The light source 151 is configured to emit light 121 based on the control signal 157 and couple it into the optical waveguide 120. The light 121 is emitted with a predetermined wavelength, intensity, phase, and / or polarization as parameters relating to the light 121.

[0043] The light sensor 152 is configured to sense and / or detect light 121 coupled out of the optical waveguide 120. The light sensor 152 is configured to transmit, based on the sensed and / or detected light 121, a phase shift, intensity change, polarization change, wavelength change, and / or frequency change relating to the light 121 to the data processing device 155 as data 156 relating to the light 121.

[0044] The data processing device 155 is configured to process the data 156 relating to the light 121. The data processing device 155 is configured to calculate a braking torque T based on the data 156 relating to the light 121. In particular, the data processing device 155 is configured to compare parameters of the emitted light 121 and parameters of the reflected and received light 121, for example, by means of spectroscopy or spectral analysis.

[0045] The measuring device 100 thus forms a fiber optic sensor (FOS) comprising a fiber optic optical waveguide 120, a signal converter or a sensor element and / or detector as the light sensor 152, and the light source 151. The optical waveguide 120 is the medium through which the light 121 can propagate. The underlying principle of the measuring device 100 is total internal reflection. The optical waveguide 120 has a cylindrical core 123 with a predetermined refractive index, and a cladding layer 124 as a further layer with a further refractive index that is typically lower than the refractive index of the core 123 (see Fig. 2), particularly in the case of the optical waveguide 120 as a single-mode fiber (SMF). The measuring device 100 is configured to sense various physical parameters, for example temperatures, pressure, and / or deformation, wherein a change in such a parameter modulates the light 120 propagating through the optical waveguide 120. By analyzing the change in the parameter(s) relating to the light in the properties of the light 120 by the data processing device 155, the influence of environmental conditions, and in particular the braking torque T, can be determined.

[0046] The light source 151, the light sensor 152, and the data processing device 155 are arranged on a circuit board 158. Thus, the light source 151, the light sensor 152, and the data processing device 155 can form a module. In another embodiment, the light source 151, the light sensor 152, and the data processing device 155 can be arranged separately from one another (not shown).

[0047] The optical waveguide 120 has a connection end 127 for connecting the light source 151 and the light sensor 152 (see Fig. 2, Fig. 3, Fig. 4 and Fig. 6).

[0048] In the Fig. The path of light 121 is illustrated in the diagram shown in Figure 1. Light 121 is emitted by light source 151 and coupled into optical fiber 120. Light 121 propagates through optical fiber 120. Light 121 can be reflected within optical fiber 120. Reflected light 121 is coupled out of optical fiber 120 and can be sensed and / or detected by light sensor 152, wherein properties of coupled-in light 121 can differ from properties of coupled-out light 121.

[0049] The data processing device 155 is configured to provide data-based services by evaluating the data 156, for example, to generate customized maintenance suggestions and / or provide a prediction of wear and / or damage. This can result in savings in maintenance effort and costs, particularly when combined with driving behavior.

[0050] Fig. Figure 2 shows a schematic representation of a measuring device 100 according to one aspect of the disclosure. The measuring device 100 according to Fig. 2 is an embodiment of the Fig. 1 shown measuring device 100. Fig. 2 is made with reference to Fig. 1 described.

[0051] In the Fig. In the embodiment shown in Figure 2, the carrier 110 has a recess 111 as a receiving section 117 for arranging the optical waveguide 120. The receiving section 117 or the recess 111 is arranged on the end face. In particular, the receiving section 117 or the recess 111 is arranged on a free surface that does not contact the brake caliper 240 and that extends in the circumferential direction relative to the rotation axis A and along the rotation axis A.

[0052] The optical fiber 120 is arranged in the recess 111. The recess 111 is dimensioned such that the optical fiber 120 can be arranged in the recess 111 in a well-defined manner and without play. A braking torque T causes a deformation of the carrier 110 and thus a deformation of the recess 111 as part of the carrier 110. By arranging the optical fiber 120 in the recess 111, the optical fiber 120 is protected, in particular, from external mechanical influences.

[0053] The recess 111 has two openings 114, 115 arranged on the vehicle side in the assembled state. In another embodiment (see Fig. 3 and Fig. 4 and Fig. 6 analogous), the recess 111 has an opening 114, 115 arranged on the vehicle side in the assembled state.

[0054] The optical waveguide 120 is arranged two-dimensionally. In another embodiment, the optical waveguide 120 is arranged three-dimensionally. The optical waveguide 120 according to Fig. 2 has a first leg 112 and a second leg 113, wherein the first leg 112 and the second leg 113 are each arranged to extend coaxially with respect to a rotational axis A of a brake disc 255 of the disc brake 250. Between the first leg 112 and the second leg 113 is a section of the waveguide 120, which is arranged perpendicular to the rotational axis A, for example, in the direction of rotation (not shown). One of the legs 112, 113 is arranged to protrude through one of the openings 114, 115.

[0055] The optical waveguide 120 has a circular cross-section 122, a core 123 and a cladding layer 124 surrounding the core 123.

[0056] Fig. 3 shows a schematic representation of an optical waveguide 120 of a measuring device 100 according to one aspect of the disclosure. The optical waveguide 120 according to Fig. 3 is an alternative to the Fig. 2 shown optical fiber 120. Fig. 3 is made with reference to Fig. 2, where the differences between the optical fibers 120 are shown in Fig. 2 and Fig. 3 are described.

[0057] The optical fiber 120 according to Fig. 3 is secured in the receiving section 117 (shown only schematically). The optical fiber 120 protrudes with the first leg 127 from the receiving section 117 on the vehicle side, for example, from the recess 111 and / or from an opening 113.

[0058] Fig. Figure 4 shows a schematic representation of an optical waveguide 120 of a measuring device 100 according to one aspect of the disclosure. The optical waveguide 120 according to Fig. 4 is an alternative to the Fig. 2 and Fig. 3 shown optical fiber 120. Fig. 4 is made with reference to Fig. 2 and Fig. 3, where the differences between the optical fibers 120 are shown in Fig. 3 and Fig. 4 are described.

[0059] The optical fiber 120 according to Fig. 4 has a serpentine shape. The optical waveguide 120 is thus arranged alternately along and against the rotation axis A. This can improve the measurement of torsion and / or increase the length of the optical waveguide 120.

[0060] Fig. 5 shows a perspective view of a detail of a carrier 110 of a measuring device 100 according to one aspect of the disclosure. The carrier 110 according to Fig. 5 is an alternative to the Fig. 2 shown carrier 110. Fig. 5 is made with reference to Fig. 2, wherein the differences between the carriers 110 are shown in Fig. 2 and Fig. 5 are described.

[0061] The carrier 110 according to Fig. 5 has a surface 116 as a receiving section 117. The measuring device 100 has an optical waveguide carrier 125 which comprises the optical waveguide 120 and is attached to the surface 116 (optical waveguide 120 not shown in Fig. 5 shown, see Fig. 6 and Fig. 7). The receiving section 117 or the surface 116 is arranged on the front side. In particular, the receiving section 117 or the surface 116 is arranged on a free surface that does not contact the brake caliper 240. The surface 116 extends in the circumferential direction relative to the rotation axis A and along the rotation axis A.

[0062] Fig. 6 shows a schematic representation of a first perspective view of an optical waveguide carrier 125 with an optical waveguide 120 of a measuring device 100 according to one aspect of the disclosure. Fig. 6 is made with reference to Fig. 1 to 5. The optical waveguide 120 can also be designed differently from the schematic representation of the Fig. 6 may have a different arrangement, for example as shown in Fig. 4. Fig. 6 shows a view of the optical waveguide carrier 125 from below, i.e. from a side of the optical waveguide carrier 125 that is hidden in the assembled state and faces the carrier 110.

[0063] The carrier 110 and the optical fiber carrier 125 are integrally connected to each other by connecting elements 126. The connecting elements 126 are screws distributed across the optical fiber carrier 125. The optical fiber carrier 125 is attached to the carrier 110 by four connecting elements 126. The optical fiber carrier 125 is a metallic plate.

[0064] Fig. 7 shows a schematic representation of a second perspective view of an optical waveguide carrier 125 of a measuring device 100 according to one aspect of the disclosure. The optical waveguide carrier 125 according to Fig. 7 is the optical waveguide carrier 125 according to Fig. 6. Fig.7 shows a view of the optical waveguide carrier 125 from above, i.e. from a side of the optical waveguide carrier 125 that is visible in the assembled state and facing away from the carrier 110. The optical waveguide 120 is located between the carrier 110 and the optical waveguide carrier 125 and is thus protected, in particular, from external mechanical influences. Reference symbol (part of the description) 100 measuring device 110 carriers 111 Recess 112 first leg 113 second leg 114 Opening 115 Opening 116 Surface 117 Recording section 120 optical fibers 120' Fiber Bragg Grating 120" fiber optic component 121 Light 122 cross section 123 core 124 cladding layer 125 fiber optic carriers 126 fasteners 127 Connection end 150 measuring arrangement 151 Light source 152 Light sensor 155 Data processing device 156 data 157 Control signal 158 circuit board 160 brake pads 200a vehicle 200b commercial vehicle 240 brake caliper 250 disc brake 255 brake disc A rotation axis T Braking torque QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2022 / 252121 A1

[0006] US 2022 / 299082 A1

[0007] US 2022 / 242383 A1

[0009]

Claims

[1] Measuring device (100) for monitoring a disc brake (250) for a vehicle (200a), in particular a commercial vehicle (200b), comprising: - a carrier (110) for movably arranging a brake caliper (240) of the disc brake (250); and - an optical waveguide (120) for coupling in and out light (121); characterized by , that - the carrier (110) has a dedicated receiving portion (117) for attaching the optical fiber (120) to the carrier (110). [2] Measuring device (100) according to claim 1, wherein the carrier (110) has a surface (116) as a receiving section (117), and the measuring device (100) has an optical waveguide carrier (125) comprising the optical waveguide (120) and fastened to the surface (116). [3] Measuring device (100) according to claim 2, wherein the carrier (110) and the optical waveguide carrier (125) are connected to one another in a materially bonded manner and / or the carrier (110) and the optical waveguide carrier (125) are connected to one another by connecting elements (126). [4] Measuring device (100) according to one of the preceding claims, wherein the carrier (110) has a recess (111) as a receiving section (117) for arranging the optical waveguide (120), and the optical waveguide (120) is arranged in the recess (111). [5] Measuring device (100) according to claim 4, wherein the recess (111) has an opening (114, 115) arranged on the vehicle side in the mounted state. [6] Measuring device (100) according to one of the preceding claims, wherein the optical waveguide (120) is arranged two- and / or three-dimensionally. [7] Measuring device (100) according to one of the preceding claims, wherein the optical waveguide (120) has a first leg (112) and a second leg (113), wherein the first leg (112) and the second leg (113) are each arranged to extend coaxially with respect to a rotation axis (A) of a brake disc (255) of the disc brake (250). [8] Measuring device (100) according to one of the preceding claims, wherein the optical waveguide (120) has a circular cross-section (122). [9] Measuring device (100) according to one of the preceding claims, wherein the optical waveguide (120) has a core (123) and a cladding layer (124) enclosing the core (123). [10] Measuring device (100) according to one of the preceding claims, wherein the optical waveguide (120) is a fiber optic component (120") comprising a fiber Bragg grating (120'). [11] Disc brake (250), comprising a measuring device (100) according to one of the preceding claims with a carrier (110), a brake calliper (240) movably arranged on the carrier (110), a brake disc (255) and brake pads (160) which can be applied over the brake disc (255). [12] Measuring arrangement (150), comprising: - a measuring device (100) according to one of the preceding claims 1 to 10 and / or a disc brake (250) according to claim 11; - a light source (151) for coupling light (121) into the optical waveguide (120); - a light sensor (152) for detecting light (121) coupled out of the optical waveguide (120); and - a data processing device (155) for evaluating data (156) relating to the light (121). [13] Measuring arrangement (150) according to claim 12, wherein the optical waveguide (120) has a connection end (127) for connecting the light source (151) and the light sensor (152). [14] Measuring arrangement (150) according to claim 12 or 13, wherein the data processing device (155) is configured to process a phase shift, intensity change, polarization change, wavelength change and / or frequency change relating to the light (121) as data (156) relating to the light (121). [15] Measuring arrangement (150) according to one of claims 12 to 14, wherein the data processing device (155) is configured to calculate a braking torque (T) based on the data (156) relating to the light (121). [16] Vehicle (200a), in particular commercial vehicle (200b), comprising a measuring device (100) according to one of claims 1 to 10, a disc brake (250) according to claim 11 and / or a measuring arrangement (150) according to one of claims 12 to 15.

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