Friction ring for a brake disc of a vehicle disc brake, brake disc for a vehicle disc brake, disc brake for a vehicle, vehicle, use of a friction ring for a brake disc of a vehicle disc brake and method for manufacturing a friction ring for a brake disc of a vehicle disc brake

Abstract

Friction ring (1) for a brake disc of a disc brake (2), preferably of a vehicle (3), comprising the friction ring (1): - a first ring section (10) with a first braking surface (10a) formed on its end face and a second ring section (11) arranged at a distance from the first ring section (10) in an axial direction (A) with a second braking surface (11a) formed on its end face, - a ring connecting section (12) that connects the first ring section (10) with the second ring section (11), characterized in that - the friction ring (1) is formed as a one-piece centrifugally cast part, and the ring connection section (12) extends between an inner circumferential surface (13) of the connecting ring located in a radial direction (R) and an outer circumferential surface (14) of the connecting ring located in a radial direction (R), and has several through holes (15) extending from the inner circumferential surface (13) of the connecting ring to the outer circumferential surface (14), wherein the through holes (15) are arranged in multiple rows.

Description

[0001] The invention relates to a friction ring for a brake disc of a vehicle's disc brake. Furthermore, the invention relates to a brake disc for a vehicle's disc brake. The invention further relates to a vehicle's disc brake and a vehicle itself. The invention also relates to the use of a friction ring for a brake disc of a vehicle's disc brake. Finally, the invention relates to a method for manufacturing a friction ring for a brake disc of a vehicle's disc brake.

[0002] A vehicle can be, for example, a motorcycle, a passenger car, a truck, or a trailer. A bicycle is also considered a vehicle. Furthermore, a vehicle can also be, for example, a rail vehicle, an aircraft, a gondola, or the like.

[0003] Disc brakes belong to the category of friction brakes. A disc brake consists of a brake disc. The brake disc includes a friction ring that is torque-resistant and connected to a flange. The flange attaches the friction ring to a hub, such as a wheel hub, which is designed to mount a wheel or rim. The disc brake also includes a brake caliper that is fixed relative to the friction ring and partially encloses the brake disc, particularly the friction ring. The brake caliper is typically fixed to the vehicle's chassis. A brake pad and brake linings are usually located inside the brake caliper. When the disc brake is applied, the brake linings contact the brake disc or the friction ring of the brake disc, thus slowing the vehicle. When the disc brake is not applied, the brake linings do not contact the disc or the friction ring.

[0004] Thus, a disc brake can be used to slow down or even completely stop the rotational movement of a vehicle's wheel or rim relative to the chassis ("full braking"). A disc brake, therefore, serves to decelerate the vehicle. During braking, the vehicle's kinetic energy is converted into heat energy, which must be dissipated to the environment for the disc brake to function efficiently. The disc brake's ability to dissipate heat energy to the environment via convection elements through thermal radiation depends primarily on the disc brake's mass, material properties, and component geometry.

[0005] It is known to manufacture friction rings and brake discs using casting processes such as sand casting in single castings, either vertically or horizontally. These manufacturing processes are labor-intensive and time-consuming; for example, cores must be produced using core shooting to achieve the desired geometry of the friction ring or brake disc. However, core shooting requires the use of substances that are harmful to health and the environment. In particular, friction rings and brake discs produced using sand casting must subsequently undergo extensive post-treatment, including cleaning and blasting, before they can be machined. Furthermore, friction rings and brake discs produced in this way generally exhibit uneven mechanical and material properties in the radial direction.For example, the hardness and microstructure profiles of friction rings manufactured using the sand casting process are uneven in the radial direction and cannot be precisely controlled to ensure uniform wear over the service life of a disc brake. Furthermore, uneven material densities and inaccuracies in the core shooting process can lead to imbalances. In particular, this manufacturing process can result in surface zone microstructure changes, microstructure defects, and white inclusions due to insufficient casting allowances and excessively rapid cooling. Finally, normalizing annealing is sometimes necessary to relieve process-related stresses. This is especially important for ventilated disc brakes to reduce design weaknesses at the transitions between webs and friction cross-sections. This process is not only time-consuming but also requires energy resources and has an environmental impact.

[0006] DE 21 15 299 A relates, for example, to a method for manufacturing composite cast brake discs with a cast friction ring forming the actual brake disc. DE 10 2014 222 989 A1 describes a molded body made of titanium aluminide, consisting exclusively of gamma titanium aluminide, in particular for use in a brake disc or brake caliper. DE 10 2015 100 807 A1 relates to a centrifugal casting die for manufacturing brake discs. DE 196 37 492 A1 relates to a ventilated brake disc.

[0007] It is therefore an object of the present invention to provide a friction ring for a brake disc of a vehicle disc brake, a brake disc for a vehicle disc brake, a vehicle, a use of a friction ring for a brake disc of a vehicle disc brake, a method for manufacturing a friction ring for a brake disc for a vehicle disc brake, and a method for manufacturing a brake disc for a vehicle disc brake, which eliminate or reduce one or more of the aforementioned disadvantages.

[0008] According to one aspect, the problem according to claim 1 is solved by a friction ring for a brake disc of a disc brake of a vehicle.

[0009] The friction ring according to the invention is designed to be torque-resistant when connected to a flange unit for use in a disc brake. The friction ring and the connected flange unit together form the brake disc of the disc brake. In operation, the brake disc is typically torque-resistant when attached to a hub, in particular a wheel hub, of a vehicle. Specifically, the friction ring is designed to engage with brake pads to brake the vehicle. During braking, frictional contact is established between the brake pads and the friction ring. Therefore, the friction ring is designed to be wear-resistant during braking and to efficiently dissipate the thermal energy induced during braking for effective braking.

[0010] In its operating state, the brake disc is partially enclosed by a stationary brake caliper. The brake caliper comprises a brake pad and brake linings. When the brake pad is actuated, usually hydraulically, the brake linings are pressed axially against the friction ring. This slows the rotating brake disc relative to the stationary brake caliper.

[0011] As previously explained, the friction ring is torque-resistant when in operation, attached to a hub, in particular a wheel hub, by means of a flange assembly. Thus, the friction ring rotates with the hub around an axis of rotation when the disc brake is not applied. Therefore, the friction ring is preferably arranged substantially coaxially to this axis of rotation when in operation.

[0012] The friction ring has a first ring section and a second ring section. The first ring section has a first braking surface on its end face. The second ring section has a second braking surface on its end face. The first and second ring sections are spaced apart axially. In particular, the first and second braking surfaces are spaced apart from each other axially. The first and second braking surfaces are oriented such that they extend substantially perpendicular to the axial direction. The first and second braking surfaces are arranged so that they face away from each other. This allows the brake pads of the disc brake to come into contact with the first and second braking surfaces during operation. It can therefore be understood that the friction ring extends axially between the first and second braking surfaces.

[0013] The first and second ring sections are annular in shape. It is particularly important to understand that, extending from the first and second braking surfaces, the first and second ring sections correspond to a partial extension of the friction ring in the axial direction. Specifically, the annular first and second ring sections form a closed ring in the circumferential direction.

[0014] Furthermore, the friction ring according to the invention is provided to have a ring connecting section that connects the first ring section to the second ring section. In particular, it is understood that the ring connecting section, together with the first and second ring sections, integrally forms the friction ring.

[0015] The first and second ring sections, as well as the ring connecting section, each extend axially with a section width. It is preferred that the section width of the first ring section and / or the second ring section and / or the ring connecting section be the same. In particular, it is preferred that the section width of the ring connecting section differs from the section width of the first and second ring sections, with the section width of the first and second ring sections preferably being the same. Preferably, the first and / or second ring section have a section width of at least 1 mm and a maximum of 20 mm. Furthermore, it is preferred that the ring connecting section has a section width of at least 0 mm and a maximum of 15 mm. It is particularly preferred that the brake disc has a width of at least 2 mm and a maximum of 50 mm.

[0016] Preferably, the friction ring has an inner circumferential surface and an outer circumferential surface. Preferably, the inner circumferential surface and / or the outer circumferential surface extend substantially orthogonally to the first and / or second braking surface. In particular, the friction ring extends radially, orthogonally to the axial direction, between the inner circumferential surface of the ring, which lies radially inside, and the outer circumferential surface of the ring, which lies radially outside the inner circumferential surface, with a ring height. The inner circumferential surface of the ring has an inner diameter, and the outer circumferential surface of the ring has an outer diameter that is larger than the inner diameter.

[0017] It may be preferred that the first and / or second ring section and / or the ring connecting section each have an inner circumferential surface of an annular disk with identical inner diameters. Furthermore, it may be preferred that the first and / or second ring section and / or the ring connecting section each have an inner circumferential surface of an annular disk with different inner diameters. In particular, it may be preferred that the first and / or second ring section each have an inner circumferential surface of an annular disk with identical inner diameters, and that the ring connecting section has an inner circumferential surface of an annular disk with an inner diameter that differs from the inner diameter of the inner circumferential surface of the annular disk of the first and second ring sections.In particular, it is preferred that the inner diameter of the ring disk's inner circumferential surface of the ring connection section is larger than the inner diameter of the ring disk's inner circumferential surface of the first and / or second ring section.

[0018] It may be preferred that the first and / or the second ring section and / or the ring connecting section each have an outer circumferential surface of an annular disk with identical outer diameters. Furthermore, it may be preferred that the first and / or the second ring section and / or the ring connecting section each have an outer circumferential surface of an annular disk with different outer diameters. In particular, it may be preferred that the first and / or the second ring section each have an outer circumferential surface of an annular disk with identical outer diameters, and that the ring connecting section has an outer circumferential surface of an annular disk with an outer diameter that differs from the outer diameter of the outer circumferential surface of the annular disk of the first and the second ring section.In particular, it is preferred that the outer diameter of the ring disk outer circumferential surface of the ring connection section is smaller than the outer diameter of the ring disk outer circumferential surface of the first and / or second ring section.

[0019] In particular, it is preferred that the outer diameter of the ring disk's outer circumferential surface is larger than the inner diameter of the ring disk's inner circumferential surface.

[0020] The friction ring according to the invention is designed as a one-piece centrifugal casting. The friction ring designed as a one-piece centrifugal casting is, in particular, a friction ring produced using a centrifugal casting process. For the production of this centrifugal casting, preferably a molten centrifugal casting compound can be fed into a mold according to the method described below. It is particularly important to understand that the friction ring designed as a one-piece centrifugal casting can be produced by cutting to length a tubular and / or cylindrical centrifugal casting blank produced using the centrifugal casting process. In particular, the term "friction ring designed as a one-piece centrifugal casting" does not refer to a friction ring produced by welding the ring sections to the ring connection section or by the like.

[0021] The friction ring according to the invention has the advantage that, depending on the temperature of the mold and the rotational speed in the radial direction of the friction ring, a desired microstructure and hardness profile can be precisely controlled. In particular, this has the advantage that the friction ring exhibits a uniform material density in both the radial and circumferential directions and is therefore free of imbalances. Consequently, when using friction rings manufactured in this way, imbalances do not need to be eliminated in a time-consuming manner before installation on the vehicle. In particular, the molds used to manufacture the friction ring can be precisely temperature-controlled, thus eliminating the need for normalizing annealing. Furthermore, friction rings manufactured in this way preferably eliminate the time-consuming post-processing steps of cleaning and blasting.

[0022] Furthermore, a friction ring manufactured as a centrifugal casting has the advantage that comparatively light slags, pores, inclusions, etc. are transported radially inwards during the liquid phase by the centrifugal forces that push the heavier cast iron towards the outer diameter and are deposited on the inner diameter or in the inner machining allowance of a cast blank of the friction ring.

[0023] A friction ring produced by centrifugal casting is a low-stress, homogeneous cast ring with high material quality, optimal strength, and minimal casting defects. Due to the process, such a friction ring is therefore free of pores, inclusions, and slag. Furthermore, the cooling process after centrifugal casting can be precisely controlled, ensuring that the resulting friction ring is free of cooling stresses. Additionally, the hardness and microstructure can be adjusted to meet customer requirements through a controlled cooling process. A centrifugally cast friction ring also already exhibits a high degree of balance, which is further enhanced by subsequent machining. By precisely controlling the hardness and microstructure, optimal wear uniformity can be guaranteed throughout the entire service life of the disc brake.

[0024] For further advantages, design variants and design details of the friction ring according to the invention and its further developments, reference is also made to the following description of the corresponding features and further developments of the brake disc, the disc brake, the vehicle and the methods for manufacturing a friction ring.

[0025] According to a preferred embodiment of the friction ring, the first braking surface and the second braking surface are manufactured using centrifugal casting.

[0026] According to the invention, the ring connection section extends between an inner circumferential surface of the connecting ring located in a radial direction and an outer circumferential surface of the connecting ring located in a radial direction, and has several through bores extending from the inner circumferential surface of the connecting ring to the outer circumferential surface of the connecting ring.

[0027] The through-holes primarily serve to cool the friction ring during braking. It can therefore be understood that the through-holes increase the surface area of ​​the friction ring to better dissipate the heat induced during braking. Thus, the through-holes have the particular effect of maintaining the required braking performance of the friction rings during braking, or rather, preventing the disc brake with such a friction ring from failing during braking.

[0028] The through-holes can be easily created by machining, in particular by drilling into the ring connection section. A friction ring produced in this way has the particular advantage that no sand cores need to be created for its manufacture, as is the case, for example, in the sand casting process, to produce these desired through-holes. Furthermore, this method has the advantage that the friction ring according to the invention cools uniformly, thus eliminating or at least significantly reducing the need for stress-relief annealing. In particular, the scrap rate is lower for friction rings produced in this way, since the stresses that occur in sand-cast friction rings in the area of ​​the thin webs at the transition to the solid ring sections, which in unfavorable cases lead to cracking, do not occur in the friction rings according to the invention.In particular, the use of the friction rings according to the invention therefore also leads to safer disc brakes in operation and thus enables safer participation in traffic.

[0029] In this preferred embodiment, the friction ring has the particular advantage that through-holes can be incorporated into the friction rings solely based on their function, without having to consider the cooling behavior or the stresses induced by the cooling of a friction ring produced by sand casting with sand cores in the design of the friction ring. This preferred design of the friction ring thus allows through-holes to be incorporated into the friction ring independently of the preceding centrifugal casting step.

[0030] Furthermore, this eliminates the need to produce expensive sand cores that require a complex process for positioning them in the sand mold. Instead, in this preferred embodiment, the friction ring allows for significantly higher accuracy in creating the through-holes than was previously possible with friction rings.

[0031] Furthermore, according to a preferred embodiment of the friction ring, the through-holes extend substantially in the radial direction. Additionally or alternatively, according to this preferred embodiment, the through-holes have a circular cross-section. Furthermore, according to this preferred embodiment, the through-holes are cylindrical. A friction ring designed in this way has the particular advantage that it can be manufactured easily, quickly, and cost-effectively using conventional tools, such as drills. It may also be particularly preferred to design the through-holes such that they have, for example, a square cross-section. A square cross-section can be produced, for example, by broaching.

[0032] Furthermore, according to a preferred embodiment of the friction ring, the through-holes are provided with a bore wall whose surface has a mean roughness Ra of at most 50 µm, 25 µm, 12.5 µm, 10 µm, 7.5 µm, 5 µm, 2.5 µm, or 1 µm. A friction ring designed in this way has the advantage over conventionally manufactured friction rings that the mean roughness of the bore wall of the through-holes is lower. This improves the flow characteristics of the air in the through-holes used for cooling the friction ring. A friction ring according to this preferred embodiment can therefore enable significantly improved heat dissipation, even though the surface area of ​​the friction ring relevant for cooling may be smaller in this preferred embodiment compared to friction rings manufactured with sand cores using the sand casting process.

[0033] In a further preferred embodiment of the friction ring, the adjacent through-holes are arranged at a distance from each other in the circumferential direction, with the distance between the adjacent through-holes being constant or variable. A friction ring with circumferentially equidistant through-holes can be manufactured relatively cost-effectively. A friction ring with circumferentially equidistant through-holes allows for the targeted adjustment of a desired cooling profile of the friction ring.

[0034] According to the invention, the through-holes are arranged in multiple rows. In a further preferred embodiment of the friction ring, the through-holes are arranged equidistantly in the circumferential direction. According to this preferred embodiment, the friction ring can have several rows of through-holes, depending on the required cooling capacity. In particular, in a friction ring with multiple rows of through-holes, the rows are spaced apart from each other in the axial direction. It may also be preferred that the through-holes of the respective rows are offset from each other in the circumferential direction. It may also be preferred that, in the case of multiple rows, the through-holes are only offset from each other in the axial direction, i.e., essentially parallel-displaced.

[0035] Furthermore, according to a preferred embodiment of the friction ring, the through-holes have a bore diameter of [missing value] and the distance between circumferentially adjacent through-holes is at least equal to the bore diameter. Additionally or alternatively, according to this preferred embodiment, the ring connection section has a ring width in the axial direction that is larger than, smaller than, or equal to the bore diameter. Depending on the size of the bore diameter in relation to the ring width or the section widths, the required cooling capacity can be specifically tailored to the application.

[0036] According to a further preferred embodiment of the friction ring, the ring connection section between adjacent through-holes is designed as a connecting web that connects the first and second ring sections.

[0037] Furthermore, according to a preferred embodiment of the friction ring, several perforated bores extend between the first and second braking surfaces. Preferably, the perforated bores have average surface roughness values ​​of at most 50 µm, 25 µm, 12.5 µm, 10 µm, 7.5 µm, 5 µm, 2.5 µm, or 1 µm.

[0038] According to a further preferred embodiment of the friction ring, the perforation bores extend between the first braking surface and the second braking surface, preferably substantially in the axial direction, and / or have a circular cross-section, and / or are cylindrical, and / or are arranged in such a way that they extend through the connecting webs of the ring connection section, and / or are arranged in such a way that they extend through the through bores of the ring connection section, and / or are spaced apart from each other in the circumferential direction at least by a distance greater than the bore diameter.

[0039] Furthermore, according to a preferred embodiment of the friction ring, the friction ring is made of grey cast iron, in particular of lamellar grey cast iron or spheroidal graphite cast iron.

[0040] Furthermore, according to a preferred embodiment of the friction ring, the first ring section and / or the second ring section extends between an inner circumferential surface of the ring disc located in the radial direction and an outer circumferential surface of the ring disc located in the radial direction outside of it, with a ring disc height, wherein the ring disc height is preferably at least 10 mm and at most 300 mm.

[0041] In addition or alternatively, according to this preferred embodiment of the friction ring, the ring connection section extends radially between the inner circumferential surface of the connection ring and the outer circumferential surface of the connection ring with a connection ring height, wherein the connection ring height is preferably at least 5 mm and at most 300 mm, and preferably the connection ring height is smaller than the ring disc height.

[0042] According to another aspect, the problem is solved by a brake disc for a disc brake of a vehicle according to claim 12.

[0043] The brake disc has a flange unit designed for attachment to a hub, in particular a wheel hub, and a friction ring as previously described, which is connected to the flange unit in a torque-resistant manner, wherein the flange unit preferably consists of or substantially comprises a light metal, in particular aluminum.

[0044] For further advantages, design variants and design details of the brake disc according to the invention and the further developments, reference is also made to the preceding description of the corresponding features and further developments of the friction ring as well as to the following description of the corresponding features and further developments of the disc brake and the vehicle as well as the method.

[0045] According to another aspect, the problem is solved by a disc brake for a vehicle according to claim 13.

[0046] The disc brake comprises a previously described friction ring and / or brake disc. Furthermore, the disc brake comprises a brake caliper arranged on the friction ring and / or brake disc, with brake pads designed to decelerate a rotational movement of the friction ring and / or brake disc relative to a chassis.

[0047] For further advantages, design variants and design details of the disc brake according to the invention and the further developments, reference is also made to the preceding description of the corresponding features and further developments of the friction ring and the brake disc as well as to the following description of the corresponding features and further developments of the vehicle and the method.

[0048] According to another aspect, the problem is solved by a vehicle according to claim 14.

[0049] The vehicle has a friction ring and / or a brake disc and / or a disc brake as previously described.

[0050] For further advantages, design variants and design details of the vehicle according to the invention and the further developments, reference is also made to the preceding description of the corresponding features and further developments of the friction ring, the brake disc, the disc brake, as well as to the following description of the corresponding features and further developments of the method.

[0051] According to a further aspect, the problem according to claim 15 is solved by using a previously described friction ring for a brake disc of a disc brake of a vehicle, wherein the vehicle is in particular a passenger car and / or a commercial vehicle and / or a two-wheeler.

[0052] For further advantages, embodiment variants and embodiment details of the use according to the invention, reference is also made to the preceding description of the corresponding features and developments of the friction ring, the brake disc, the disc brake, as well as to the following description of the corresponding features and developments of the method.

[0053] According to a further aspect, the problem of claim 16 is solved by a method for manufacturing a friction ring for a brake disc of a vehicle's disc brake. In particular, the problem of claim 16 is solved by a method for manufacturing a friction ring for a brake disc of a vehicle as described above.

[0054] The friction ring comprises a first ring section with a first braking surface formed on its end face and a second ring section arranged axially spaced from the first ring section, also with a second braking surface formed on its end face. Furthermore, the friction ring has a connecting ring section that links the first ring section to the second ring section. In particular, the present friction ring exhibits features of the friction ring described above.

[0055] The procedure involves several steps to solve the problem: The method comprises providing a centrifugal casting machine with a die for centrifugal casting, wherein the die is in particular cylindrical, preferably tubular. The method further comprises the step of applying a coating to the inside of the die. It is further provided that the method involves feeding molten centrifugal casting compound, in particular molten gray cast iron, and most preferably molten lamellar gray cast iron, into the die coated with the coating. The fed centrifugal casting compound is then centrifugally cast. Cooling of the centrifugally cast material is then provided so that it solidifies into a tubular casting blank.This is followed by blasting of the cooled tubular cast blank, and the production of the brake disc with the first ring section with the first braking surface arranged on the front and the second ring section with the second braking surface arranged on the front by mechanical machining, in particular by turning or milling.

[0056] It may be preferable to design the mold such that the friction rings can be produced individually in the mold using centrifugal casting. In particular, it may be preferable for the mold to be designed to produce a single friction ring or several friction rings individually using centrifugal casting. Individual production of a friction ring means, in particular, that friction rings produced in this way already have a basic shape of a friction ring intended for operation after centrifugal casting. In particular, with this type of individual production of a friction ring, no cutting of individual friction ring blanks from the casting blank is necessary.

[0057] For further advantages, embodiment variants and embodiment details of the inventive method and further developments, reference is also made to the preceding description of the corresponding features and further developments of the friction ring, the brake disc, the disc brake and the vehicle.

[0058] According to a preferred embodiment of the method, the step of producing the brake disc includes sawing off a brake disc blank from the cooled cast blank.

[0059] Furthermore, it is preferably additionally or alternatively provided that the procedure includes the following steps: - Drilling through holes, particularly in a radial direction, preferably in the ring connection section, and / or - Incorporating multiple cooling channels extending between the first and second braking surfaces, in particular through connecting webs of the ring connecting section, and / or - Cutting one or more grooves into the first and / or second braking surface.

[0060] The methods according to the invention and their possible further developments have features or process steps that make them particularly suitable for use with a friction ring and / or a brake disc and / or a disc brake and / or a vehicle according to the invention, as well as the respective further developments.

[0061] For further advantages, design variants and design details of these further aspects and their possible further developments, reference is also made to the previously given description of the corresponding features and further developments of the friction ring, the brake disc, the disc brake, and the vehicle.

[0062] Preferred embodiments of the invention are explained by way of example with reference to the accompanying figures. These show: Fig. 1: a schematic side view of an exemplary embodiment of a vehicle with a disc brake in a preferred embodiment; Fig. 2: a schematic view of a preferred embodiment of a friction ring of the in Fig. 1 preferred embodiment of the disc brake provided; Fig. 3: a schematic top view of the in Fig. 2 preferred embodiment of the friction ring provided; Fig. 4: a schematic side view of the in Fig. 2 preferred embodiment of the friction ring provided; Fig. 5: a schematic sectional view of the [unclear] in the Fig. 4. Friction ring shown schematically in side view; and Fig. 6: a schematic block diagram of a preferred embodiment of a method for manufacturing a friction ring for a brake disc of a disc brake of a vehicle for manufacturing a previously illustrated disc brake 2 with a previously illustrated friction ring 1.

[0063] Fig. Figure 1 is a schematic side view of an exemplary embodiment of a truck 3 with a disc brake 2 in a preferred embodiment. The disc brake 2 has a brake disc with a friction ring, as shown by way of example in relation to the Fig. 2, Fig. 3, Fig. 4 to Fig. 5 is described in detail below. For the operation of the disc brake 2, the friction ring is connected to a flange in a torque-resistant manner. The brake disc is in turn connected via the flange in a torque-resistant manner to a wheel hub, to which a wheel or rim of the vehicle 3 is attached. To achieve a braking effect, the disc brake 2 comprises a brake caliper, which, when the disc brake is in operation, is fixed to the chassis of the vehicle 3 with respect to the brake disc. The brake caliper is arranged such that it partially encloses the brake disc 1. To decelerate the vehicle 3, the brake caliper has a brake pad for actuating brake linings, as well as the brake linings themselves, which, when the brakes are applied, bear against the brake disc, thus decelerating the vehicle. When the disc brake is not applied, the brake linings do not bear against the disc brake or the friction ring.The brake pads are typically positioned at a distance from the brake disc. This allows disc brakes to, for example, slow down or completely prevent the rotational movement of the wheel or rim relative to the vehicle's chassis.

[0064] Fig. Figure 2 shows a schematic view of a preferred embodiment of a friction ring 1 made of grey cast iron, which is in Fig. 1. In the preferred embodiment of the disc brake 2, the friction ring 1 has several annular sections with respect to an axial direction A. These are, firstly, a first annular section 10 with a first braking surface 10a formed on its end face, and secondly, a second annular section 11, which forms a second braking surface 11a on its end face. It can be seen that the first and second annular sections 10, 11 are aligned coaxially with each other and spaced apart axially. The first and second annular sections 10, 11 are aligned such that the first and second braking surfaces 10a, 11a extend orthogonally to the axial direction A and face away from each other, i.e., their end faces are directed outwards. This arrangement and orientation allows the first and second braking surfaces 10a, 11a to come into contact with the brake pads arranged in the brake caliper when the vehicle is braked.

[0065] The first and second ring sections 10, 11 are connected to each other by a ring connecting section 12. According to the invention, the first and second ring sections 10, 11 and the ring connecting section 12 are formed in one piece as centrifugally cast parts. This means, in particular, that the first and second ring sections 10, 11 and the ring connecting section 12 are manufactured using a centrifugal casting process. Specifically, this means that the individual sections 10, 11, 12 are not welded together or connected to each other in a form-fit or force-fit manner. However, it is understood that the friction ring 1, formed as a one-piece centrifugally cast part, can be cut to length from a tubular casting blank produced by centrifugal casting and / or partially machined.

[0066] It can be seen that the friction ring 1 extends axially between the first and second braking surfaces 10a, 11a over a ring width. It is also clear that the first and second ring sections 10, 11, as well as the ring connecting section 12, each extend over a section width. In this preferred embodiment, the section width of the first and second ring sections 10, 11 is smaller than the section width of the ring connecting section 12. Alternatively, it may of course also be preferred that the section width of the first and second ring sections 10, 11 is larger than the section width of the ring connecting section 12.

[0067] Furthermore, it can be seen that the friction ring extends in a radial direction R, orthogonal to the axial direction A, between an inner circumferential surface of the ring disc and an outer circumferential surface of the ring disc, with the outer circumferential surface of the ring disc being located on the outside of the inner circumferential surface of the ring disc in the radial direction R. Therefore, the inner circumferential surface of the ring disc has an inner diameter that is smaller than the outer diameter of the outer circumferential surface of the ring disc. Fig. Figure 2 illustrates that the individual sections 10, 11, 12 of the friction ring 1 can have inner circumferential surfaces of the ring disc with different inner diameters and outer circumferential surfaces of the ring disc with different outer diameters. In the Fig. In the preferred embodiment shown in Figure 2, the inner diameters of the annular disk inner circumferential surfaces of the two ring sections 10, 11 and the outer diameters of the annular disk outer circumferential surfaces of the two ring sections 10, 11 are identical. Furthermore, the outer diameter of the annular disk outer circumferential surface of the ring connecting section 12 is smaller than the outer diameter of the first and second ring sections 10, 11. Conversely, the inner diameter of the annular disk inner circumferential surface of the ring connecting section 12 is larger than the inner diameter of the annular disk inner circumferential surfaces of the first and second ring sections 10, 11. This results in an annular circumferential groove on both the outer and inner surfaces of the ring connecting section 12. This is also illustrated in the schematic sectional view in Figure 2. Fig. 5.

[0068] The ring connection section 12 has several through bores 15 which extend cylindrically with a circular cross-section between the inner circumferential surface of the ring disc and the outer circumferential surface of the ring disc for cooling purposes.

[0069] In the present preferred embodiment, the through-holes 15 extend substantially in the radial direction R. The through-holes are produced by machining the centrifugally cast part. Preferably, the surface of the bore walls of the through-holes 15 is given a mean roughness value R. aThe surface roughness is generated by a maximum of 50 µm; however, smaller average roughness values ​​are also possible, as explained in relation to the general description. The through-holes were introduced into the friction ring 1 and its ring connection section 12 in such a way that they are equidistant from each other in the circumferential direction U. Due to the constant cross-section in the radial direction, it is understood that the distance between the circumferentially adjacent through-holes 15 decreases from the outer circumferential surface of the ring disc towards the inner circumferential surface. This is illustrated, in a highly simplified schematic, by the sectional view shown in the Fig. 2 of the friction ring 1 shown. In any case, it can be seen that, due to this arrangement of the through-holes, the ring connection section 12 forms connecting webs 16 between adjacent through-holes 15, which connect the first and second ring sections. This is particularly evident in Fig. 3 clearly.

[0070] Of course, the through-holes can also have a different shape and arrangement. For example, it may be preferred that the cross-section of the through-holes 15 varies between the outer circumferential surface of the ring disc and the inner circumferential surface, in particular that it decreases or increases. In a preferred embodiment, it may also be preferred that the through-holes are curved between the outer circumferential surface of the ring disc and the inner circumferential surface. Curved through-holes can, for example, be produced by milling.

[0071] In the Fig. In the preferred embodiment of the friction ring 1 shown in Figure 2, a single row of through-holes 15 is provided. It may also be preferred to provide friction rings with multiple rows of through-holes. In this case, the friction rings can have several rows of through-holes arranged parallel to each other in the axial direction A. Additionally or alternatively, it may also be preferred that the multiple rows of through-holes 15 are arranged offset from one another in the circumferential direction U.

[0072] In the present preferred embodiment, it is preferred that the through-holes 15 have a bore diameter D that corresponds substantially to the section width of the ring connection section 12. In an alternative preferred embodiment, it may be preferred that the bore diameter D is smaller than the section width of the ring connection section 12. Alternatively, it may of course also be preferred that the bore diameter D is larger than the section width of the ring connection section 12.

[0073] The in Fig. The preferred embodiment of the friction ring 1 shown in Figure 2 further comprises several perforation bores 17 extending between the first and second braking surfaces 10a, 11a. In the present preferred embodiment, the perforation bores 17 extend essentially in the axial direction as cylindrical channels with a circular cross-section. These serve, on the one hand, to collect dirt and, on the other hand, to interrupt a thin film of liquid that would otherwise form on the braking surfaces in wet conditions. This ensures the required braking performance despite dirt and moisture. It should be understood that, in addition to or as an alternative to the perforation bores, grooves, for example milled spiral grooves or the like, can also be provided, which likewise serve to interrupt any liquid film and collect dirt.

[0074] Fig. Figure 6 shows a schematic block diagram of a preferred embodiment of a method 1000 for manufacturing the friction ring 1 described above for the brake disc of the disc brake 2 of the in Fig. Figure 1 schematically represents a vehicle. The process for manufacturing the friction ring 1 comprises the following steps: Method 1000 comprises providing 1010 a centrifugal casting machine with a die for centrifugal casting, wherein the die is in particular cylindrical, preferably tubular. Method 1000 further comprises the step of applying 1020 a coating to an inner surface of the die. Method 1000 further comprises feeding 1030 a molten centrifugal casting compound, in particular molten gray cast iron, and more preferably molten lamellar gray cast iron, into the die coated with the coating. Subsequently, centrifugal casting 1040 of the fed centrifugal casting compound is carried out. Cooling 1050 of the centrifugally cast centrifugal casting compound is then provided, so that it solidifies into a tubular casting blank.This is followed by blasting 1060 of the cooled tubular cast blank, and the production 1070 of the brake disc with the first ring section having the first braking surface arranged on its end face and the second ring section having the second braking surface arranged on its end face by mechanical machining, in particular by turning or milling. Furthermore, the introduction 1080 of through holes 15, in particular in a radial direction R, preferably in the ring connection section 12, as well as the introduction 1090 of several perforation holes 17, which extend between the first and second braking surfaces 10a, 11a, in particular through connecting webs 16 of the ring connection section 12, is provided. Reference symbol list 1 friction ring 2 disc brakes 3 vehicles 10 first ring section 10a first braking surface 11 second ring section 11a second braking surface 12 Ring connection section 13 Inner circumferential area of ​​the ring 14 Ring outer circumferential area 15 through holes 15a Surface 16 Connecting bridge 17 perforation holes A Axial direction D bore diameter R Radial direction U circumferential direction

Claims

[1] Friction ring (1) for a brake disc of a disc brake (2), preferably of a vehicle (3), comprising the friction ring (1): - a first ring section (10) with a first braking surface (10a) formed on its end face and a second ring section (11) arranged at a distance from the first ring section (10) in an axial direction (A) with a second braking surface (11a) formed on its end face, - a ring connecting section (12) that connects the first ring section (10) with the second ring section (11), characterized by , that - the friction ring (1) is formed as a one-piece centrifugally cast part, and the ring connection section (12) extends between an inner circumferential surface (13) of the connecting ring located in a radial direction (R) and an outer circumferential surface (14) of the connecting ring located in a radial direction (R), and has several through holes (15) extending from the inner circumferential surface (13) of the connecting ring to the outer circumferential surface (14), wherein the through holes (15) are arranged in multiple rows. [2] Friction ring (1) according to the preceding claim 1, wherein the through holes (15) - extend essentially in the radial direction (R), and / or - have a circular cross-section, and / or - are cylindrical in shape. [3] Friction ring (1) according to one of the preceding claims 1 or 2, wherein the through holes (15) have a bore wall whose surface (15a) has a mean roughness Ra of a maximum of 50 µm, 25 µm, 12.5 µm, 10 µm, 7.5 µm, 5 µm, 2.5 µm or 1 µm. [4] Friction ring (1) according to any one of the preceding claims 1 to 3, wherein the adjacent through holes (15) are spaced apart from each other in a circumferential direction (U), wherein the distance between the adjacent through holes (15) is constant or different. [5] Friction ring (1) according to any one of the preceding claims 1 to 4, wherein - the through holes (15) are arranged equidistantly spaced in the circumferential direction (U). [6] Friction ring (1) according to any one of the preceding claims 1 to 5, wherein the through holes (15) have a bore diameter (D) and - the distance between adjacent through holes (15) in the circumferential direction (U) is at least equal to the hole diameter (D), and / or - the ring connection section (12) in the axial direction (A) has a ring width that is larger than the bore diameter (D) or smaller than the bore diameter (D) or corresponds to the bore diameter (D). [7] Friction ring (1) according to any one of the preceding claims 1 to 6, wherein the ring connection section (12) between adjacent through holes (15) is each designed as a connecting web (16) which connects the first and second ring sections (10, 11) together. [8] Friction ring (1) according to any one of the preceding claims 1 to 7, wherein several perforation bores (17) extend between the first and second braking surface (10a, 11a). [9] Friction ring (1) according to the preceding claim 8, wherein the perforation holes (17) - extend between the first braking surface (10a) and the second braking surface (11a), preferably substantially in the axial direction, and / or - have a circular cross-section, and / or - are cylindrical in shape, and / or - are arranged in such a way that they extend through the connecting webs (16) of the ring connecting section (12), and / or - are arranged such that they extend through the through-holes (15) of the ring connection section (12), and / or - are spaced apart from each other in the circumferential direction (U) at least by a distance greater than the bore diameter (D). [10] Friction ring (1) according to any one of the preceding claims 1 to 9, wherein the friction ring (1) is made of gray cast iron, in particular of lamellar gray cast iron or spheroidal graphite cast iron. [11] Friction ring (1) according to any one of the preceding claims 1 to 10, - wherein the first ring section (10) and / or the second ring section (11) extends between an inner circumferential surface of the ring disk located radially inside and an outer circumferential surface of the ring disk located radially outside thereto, with a ring disk height, wherein the ring disk height is preferably at least 10 mm and at most 300 mm, and / or - the ring connection section (12) extends in radial direction (R) between the inner circumferential surface (13) of the connecting ring and the outer circumferential surface (14) of the connecting ring with a connecting ring height, wherein the connecting ring height is preferably at least 5 mm and at most 300 mm, wherein the connecting ring height is preferably less than the ring disc height. [12] Brake disc for a disc brake (2) of a vehicle (3), comprising a flange unit designed for attachment to a hub, in particular a wheel hub, and a friction ring (1) according to one of the preceding claims, which is connected to the flange unit in a torque-resistant manner, wherein the flange unit preferably consists of or substantially comprises a light metal, in particular aluminium. [13] Disc brake (2) for a vehicle (3), comprising a friction ring (1) according to any one of the preceding claims 1 to 11 and / or a brake disc according to the preceding claim 12 and a brake caliper arranged on the friction ring (1) and / or the brake disc with brake linings designed to decelerate a rotational movement of the friction ring (1) and / or the brake disc relative to a chassis. [14] vehicle (3) comprising a friction ring (1) according to any one of the preceding claims 1 to 11 and / or a brake disc according to the preceding claim 12 and / or a disc brake (2) according to the preceding claim 13. [15] Use of a friction ring (1) according to any one of the preceding claims 1 to 11 for a brake disc of a disc brake (2) of a vehicle (3), wherein the vehicle (3) is in particular a passenger car and / or a commercial vehicle and / or a two-wheeler. [16] Method (1000) for manufacturing a friction ring (1) according to any one of the preceding claims 1 to 11, for a brake disc of a disc brake (2) of a vehicle (3), comprising the friction ring (1): - a first ring section (10) with a first braking surface (10a) formed on its end face and a second ring section (11) arranged at an axial distance (A) from the first ring section (10) with a second braking surface (11a) formed on its end face, and - a ring connecting section (12) that connects the first ring section (10) to the second ring section (11), and the method characterized by the steps: - Providing a centrifugal casting machine with a die for centrifugal casting, wherein the die is in particular cylindrical, preferably tubular, - Applying a coating to an inside of the mold, - Feeding a molten centrifugal casting compound, in particular as molten grey cast iron, especially preferably as molten lamellar grey cast iron, into the mold coated with the coating, - Centrifugal casting of the supplied centrifugal material, - Cooling of the centrifugally cast mass so that it solidifies into a tubular casting blank, - Blasting of the cooled tubular cast blank, and - Producing the brake disc with the first ring section (10) with the frontally arranged first braking surface (10a) and the second ring section (11) with the frontally arranged second braking surface (11a) by mechanical machining, in particular by turning or milling. [17] Method (1000) according to the preceding claim 16, - wherein the step of producing the brake disc comprises sawing a brake disc blank from the cooled cast blank, and / or the method further comprises the steps: - Insertion of through holes (15), in particular in a radial direction (R), preferably in the ring connection section (12), and / or - Including several perforation holes (17) extending between the first and second braking surfaces (11a), in particular through connecting webs (16) of the ring connecting section (12), and / or - Cutting one or more grooves into the first and / or second braking surface.

Images