Friction unit for a vehicle disc brake and brake caliper

Abstract

Friction unit (100) for a disc brake (300) of a vehicle, comprising: a support plate (1); and a friction lining (2) with a friction material layer (21) having a contact surface (21a) for contacting a disc (310) and a backing layer (22) having an inner surface (22a) oriented opposite to the contact surface (21a) and connected to the carrier plate (1), wherein the underlay layer (22) has at least one slot (3) which is formed in the inner surface (22a) and forms a cavity, wherein the underlay layer (22) has a predetermined thickness (t22), and wherein the at least one slot (3) has a depth (d3) which is less than the thickness (t22) of the underlay layer (22).

Description

TECHNICAL AREA

[0001] The present invention relates to a friction unit for a disc brake of a vehicle such as an automobile, a bus, a truck, a motorcycle or the like, and a brake caliper. BACKGROUND

[0002] A friction brake for a vehicle typically comprises a disc coupled to a rotating part of the vehicle's axle that carries the wheel, and a caliper coupled to a stationary part of the axle. The caliper includes a carrier and a friction unit that is guided within the carrier parallel to a rotating axis of the disc. The friction unit comprises a backing plate and a friction lining mounted on the backing plate. To brake the wheel, the friction unit is forced toward the disc, so that the friction lining is pressed against the disc by an external braking force, which can be generated, for example, by hydraulic pressure, creating a frictional force between the friction lining and the disc.

[0003] During braking, when the friction pad is in contact with the disc, a relative movement occurs between the rotor and the friction element, which can cause vibrations, primarily of the disc and the friction pad. Consequently, squealing noises can occur.

[0004] To reduce squeaking noises, various countermeasures have been proposed. For example, the friction linings are typically provided with slots and / or chamfers on a contact surface that comes into contact with the disc to reduce noise. Such friction units are described, for example, in US 2009 / 0032343A1 and EP 3155283A1.

[0005] DE 100 41 308 A1 further describes filling the slots formed in the contact surface with a filler material. In the friction lining disclosed in DE 697 14 407 T2, the slots formed in the contact surface completely penetrate the friction material layer and an elastic polymer layer arranged behind it.

[0006] DE 143 08 69 A discloses a friction lining in which a friction material layer is connected to a carrier plate, wherein bores penetrate the friction material layer and terminate in a groove formed on an inner surface of the friction material layer facing the carrier plate.

[0007] The slots formed in the contact surface of the friction lining are designed to reduce local pressure peaks when the lining is pressed against the disc. While slots in the contact surface can be effective in reducing squeaking noises, their effectiveness can diminish over time. Because the contact surface is subject to wear, the geometry of the slots changes over the lifespan of the friction lining. Furthermore, dirt can accumulate in the slots.

[0008] JP 2015-072023 A discloses a friction unit for a disc brake comprising a carrier plate and a friction lining, which has a friction material layer and a backing layer arranged between the friction material layer and the carrier plate. The backing layer serves for thermal insulation and is formed by a plurality of individual parts that are spaced apart from one another, so that gaps are formed between the individual parts.

[0009] DE 100 52 164 A1 describes a friction unit comprising a carrier plate, a friction material layer, and a connecting plate made of a rigid material, such as steel, arranged between the friction material layer and the carrier plate. The connecting plate is connected to the carrier plate and has a plurality of through holes, the friction material being pressed into the through holes so that the connecting plate mechanically reinforces the friction material layer.

[0010] In JP S61 - 201 943 A, a friction unit is disclosed comprising a carrier plate, a friction material layer and a heat insulation layer arranged between the carrier plate and the friction material layer, wherein the carrier plate is provided with pins which penetrate the heat insulation layer and project into the friction material layer.

[0011] DE 696 105 46 T2 discloses a friction lining with a carrier plate on whose surface projecting channel elements are attached, and with a friction lining which has a friction material layer and a backing layer into which the channel elements project. REVELATION OF THE INVENTION

[0012] One of the objects of the present invention is to provide an improved friction unit for a disc brake. In particular, it is an object to provide a robust friction unit that helps to further reduce noise during braking.

[0013] The present invention provides a friction unit according to claim 1, a friction unit according to claim 5, and a brake caliper according to claim 8. Further embodiments of the present invention are the subject of the dependent claims and the following description with reference to the drawings.

[0014] According to a first aspect of the invention, a friction unit for a vehicle disc brake comprises a carrier plate and a friction lining. The friction lining comprises a friction material layer having a contact surface for contacting a disc, and a backing layer having an inner surface oriented opposite to the contact surface and connected to the carrier plate, wherein the backing layer has at least one slot formed therein in the inner surface of the backing layer.

[0015] According to a second aspect of the invention, a brake caliper for a disc brake of a vehicle comprises a carrier and a friction unit according to the first aspect of the invention, which is movably guided within the carrier along an axial direction or fixed within the carrier.

[0016] One of the ideas of the present invention is to provide a friction unit for a disc brake with a friction lining, in which at least one slot is provided spaced apart from a contact surface of the friction lining. In particular, the slot is formed in a backing layer arranged between a friction material layer of the friction lining and a carrier plate. The backing layer is connected to the carrier plate by a first surface or inner surface in which one or more slots may be formed. The backing layer and the friction lining are connected to each other. Generally, the backing layer acts as a damping layer and is made of a more elastic material composition than the friction material layer.

[0017] One of the advantages of the present invention is that the slot retains its geometry over the lifetime of the friction unit, since it is not exposed on the contact surface, which is subject to wear. Furthermore, providing the slot in the backing layer very effectively reduces noise caused by vibrations, as the backing layer is close to the source of vibrational friction.

[0018] According to some embodiments, the material composition of the backing layer can have the same components as the friction material layer, but in different percentages, or one or more components can be replaced by different components. In general, the backing layer can comprise one or more of the following components: acrylic fibers, aramid fibers, inorganic material, rubber powder, rubber beads, binders and adhesives, nitrile rubber, ethylene propylene rubber, styrene-butadiene rubber.

[0019] According to some embodiments, the at least one slot can terminate at a circumference of the backing layer. The backing layer can, for example, have a circular, rectangular, substantially rectangular, or otherwise shaped circumference. The at least one slot can extend towards the circumference, forming a recess in the circumferential surface of the backing layer. The slot can terminate within the backing layer at a distance from the circumference or can terminate at another point on the circumference.

[0020] According to some embodiments, the at least one slot can extend between opposite sections of a circumference of the backing layer. That is, the slot can extend completely through the backing layer from one point on the circumference to another point on the circumference. For example, if the circumference is substantially rectangular and has two opposite long sides and two opposite short sides, the slot can extend from one long side to the other long side or from one short side to the other short side.

[0021] According to some embodiments, the at least one slot extends at a distance from the circumference of the underlay. In other words, the slot can extend completely within the underlay, e.g., beginning and ending within the underlay or forming a closed frame such as a ring or the like.

[0022] According to some embodiments, the slot can extend linearly. Alternatively, the slot can also have several linear sections that are connected to each other, and / or it can have curved sections.

[0023] According to a first alternative of the invention, the at least one slot forms a cavity. That is, the backing material is removed where the slot is located, and no other solid or liquid material is present in the slot. Therefore, the slot defines a cavity in the backing material. This allows the slots to be easily created during the process of applying the backing material to the substrate, e.g., by placing ridges on the surface of the substrate, applying the backing material to the surface of the substrate with the ridges placed thereon, so that the slots are formed where the ridges are located, and removing the ridges, e.g., by pulling them out of the backing material.

[0024] According to a second alternative according to the invention, the at least one slot is filled with a filler material. The filler material can generally be a material that is mechanically softer than the underlying layer. For example, the filler material can be an elastically deformable material or a plastic material, such as a paste. This allows the filler material to be easily deformed when pressure is applied to the friction lining during braking, so that pressure peaks are reliably dissipated. The selection of specific material properties for the filler material allows for further customization of the damping characteristics. The filler material can be introduced into the slots, which are produced as described above, in a liquid state.Alternatively, the filler material can first be applied to the surfaces of the carrier plate and, if necessary, hardened, and then the underlay material can be applied to the surface of the carrier plate, with the filler material placed on top so that the slots are formed where the filler material is located.

[0025] According to some embodiments, the filler material may have one or more of the following properties: a bulk modulus that is at least 30% smaller than that of the backing layer; a Poisson's ratio that is at least 10% larger than that of the backing layer; a modulus of elasticity that is at least 20% smaller than that of the backing layer; a density that is at least 20% smaller than that of the backing layer.

[0026] According to the present invention, the filling material contains or consists of a phenolic resin, expanded polystyrene, wood fibers or rubber.

[0027] According to the invention, the backing layer has a predetermined thickness, and the at least one slot has a depth that is less than the thickness of the backing layer. The thickness of the backing layer can, for example, be in a range between 1 mm and 3 mm. The depth of the slot can, for example, be in a range between 0.8 mm and 3 mm, preferably between 0.8 mm and 2 mm.

[0028] According to some embodiments, the width of at least one slot can, for example, be in a range between 3 mm and 10 mm, preferably between 5 mm and 7 mm.

[0029] According to some embodiments, the contact surface of the friction material layer can be a continuous surface with a flat main section. The main section can, for example, comprise at least 85%, preferably 95%, of the contact surface. Thus, no slots are present in the contact surface. Optionally, however, a chamfer can be formed in one end region of the contact surface. Due to the slots formed in the backing layer, slots in the contact surface of the friction unit are not necessarily required. This avoids the disadvantages of such slots while still effectively reducing noise and vibration.

[0030] According to some embodiments, the brake caliper may further include an actuator mounted in the carrier and designed to move the movably guided friction unit along the axial direction. For example, the actuator may be a piston. The piston may, for example, be driven by hydraulic pressure.

[0031] The features and advantages described herein with respect to one aspect of the invention are also disclosed for the other aspects and vice versa.

[0032] With regard to directions and axes, in particular directions and axes relating to the course of physical structures, the course of an axis, direction or structure “along” another axis, direction or structure is understood to mean that these, in particular the tangents resulting at a respective point of the structures, each run at an angle of less than or equal to 45 degrees, preferably less than 30 degrees and in particular preferably parallel to each other.

[0033] With regard to directions and axes, in particular directions and axes relating to the course of physical structures, the course of an axis, direction or structure "perpendicular" to another axis, direction or structure shall be understood to mean that these, in particular the tangents resulting at a respective point of the structures, each run at an angle of greater than or equal to 45 degrees, preferably greater than or equal to 60 degrees and particularly preferably perpendicular to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] For a more complete understanding of the present invention and its advantages, reference is now made to the following description in conjunction with the accompanying drawings. The invention is explained in more detail below with reference to exemplary embodiments shown in the schematic figures of the drawings. These show: Fig. 1 A schematic cross-sectional view of a disc brake with a brake caliper according to an embodiment of the invention. Fig. 2 A schematic top view of a friction surface of a friction unit according to an embodiment of the invention. Fig. 3 a schematic cross-sectional view of the friction unit made of Fig. 2 along line AA. Fig. 4 a schematic detail view of the in Fig. 3 areas marked with the letter X. Fig. 5 the detail from Fig. 4 according to a further embodiment of the invention. Fig. 6 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 7 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 8 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 9 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 10 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 11 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 12 a schematic cross-sectional view of a friction unit according to an embodiment of the invention during a manufacturing process of the friction unit. Fig. 13 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 14 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 15 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 16 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 17 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 18 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 19 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention. Fig. 20 a schematic top view of a friction surface of a friction unit according to a further embodiment of the invention.

[0035] In the figures, identical reference symbols denote identical elements, unless otherwise specified. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION

[0036] Fig. Figure 1 schematically shows a disc brake 300 of a vehicle. The brake 300 can be used, for example, in a car, a bus, a truck, a motorcycle, or the like. As shown in Fig. As shown schematically in Figure 1, the brake 300 comprises a brake caliper 200 and a disc 210.

[0037] As in Fig. The brake disc 210, shown schematically in Figure 1, will not be described in detail below. Generally, the disc 210 can have a circular shape and comprises opposing friction surfaces 210a and 210b. The disc 210 is designed to be coupled to a wheel of the vehicle and is rotatable about the axis of rotation A210.

[0038] The brake caliper 200 is in Fig. Figure 1 is shown only in a simplified and schematic form. As shown, the brake caliper 200 has a carrier or housing 205, a pair of friction units 100 and an actuator in the form of a piston 215.

[0039] As in Fig. As shown schematically in Figure 1, the carrier 205 can have a first housing section 205A, a second housing section 205B and a bridge 205C.

[0040] As in Fig. As shown schematically in Figure 1, the first housing section 205A can have a guide structure, e.g., in the form of a cylindrical bore 206 for guiding the piston 215. The second housing section 205B is arranged opposite the first housing section 205A with respect to an axial direction A. As shown in Figure 1, the first housing section 205A can be arranged in a way that guides the piston 215. Fig. As shown schematically in Figure 1, the second housing section 205B can extend along a radial direction R, which is transverse to the axial direction A. For example, the second housing section 205B can have two fingers spaced apart from each other in a circumferential direction C. Alternatively, the second housing section 205B can be plate-shaped. The first and second housing sections 205A, 205B are connected to each other by the bridge 205C, which extends substantially along the axial direction A. For example, the first housing section 205A, the second housing section 205B, and the bridge 205C can be formed in one piece.

[0041] As further in Fig. As shown schematically in Figure 1, the first housing section 205A, the second housing section 205B, and the bridge 205C define a passage 202. The passage 202 is bounded in the axial direction A by the first housing section 205A and the second housing section 205B and in the radial direction R by the bridge 205C. The brake disc 210 extends through the passage 202, as shown in Figure 1. Fig. 1 shown schematically.

[0042] The carrier or housing 205 can be movably mounted on a coupling carrier (not shown). The coupling carrier can be mounted on a steering knuckle or, more generally, on the axle of the vehicle. In particular, the carrier 205 can be movably guided along the carrier along the axial direction A. In general, the axial direction A and the axis of rotation A200 can be parallel to each other.

[0043] The friction units 100 are positioned on opposite sides of the passage 202 and are coupled to the carrier 205, for example, via corresponding clamps (not shown). Generally, at least one of the friction units 100 is coupled to the carrier 205 in such a way that it can be moved along the axial direction A by the piston 215. In the example of Fig. 1 A first friction unit 100A is movably guided along the axial direction A in the first housing section 205A, and a second friction unit 100B is fixedly attached to the second housing section 205B, e.g. to the fingers.

[0044] The configuration of the friction units 100 is explained in more detail below.

[0045] The piston 215 is guided in the first housing section 205A such that it is movable along the axial direction A in order to move the first friction unit 100A along the axial direction A. As shown in Fig. As shown by way of example in Figure 1, the piston 215 can be guided in the bore 206. The piston 215 can be moved towards and away from the passage 202 by applying hydraulic pressure to a rear end of the piston. However, the invention is not limited to this. The piston 215 can also be moved using an electric actuator, such as a motor, or by means of electromagnetic force. Furthermore, another suitable actuator can be used instead of a piston 215.

[0046] When the piston 215, or more generally the actuator, moves the first friction unit 100A into contact with the friction surface 210a of the disc 210, an axial displacement of the carrier 205 occurs, since the carrier 205 is guided so as to be movable. This axial displacement moves the second friction unit 100B into contact with the opposite friction surface 210b of the disc 210. Consequently, a frictional force is generated between the friction linings 100 and the disc 210, which brakes the disc 210.

[0047] A friction unit 100 of the brake caliper 200 is shown by way of example and schematically in a top view in Fig. 2 shown. Fig. Figure 3 shows a cross-sectional view of the friction unit 100 along line AA in Fig. 2. Fig. 4 shows detail X from Fig. 3.

[0048] As in the Fig. 2, Fig. 3 to Fig. As shown in Figure 4, the friction unit 100 has a carrier plate 1 and a friction lining 2.

[0049] The support plate 1 is a generally flat component with a planar extent. The support plate 1 comprises a first surface 1a and a second surface 1b, which is oriented opposite to the first surface 1b. As in Fig. As shown in Figure 2, the support plate 1 can comprise a main section 15, on which the first and second surfaces 1a, 1b are formed, and guide sections 16 that project laterally from the main section 15 in opposite directions, e.g., along a friction unit circumferential direction C1. When mounted in the support 205, the guide sections 16 can engage with guide structures (not shown) formed in the support 205 to guide the friction unit 100 axially. The main section 15 can essentially have the shape of a circular segment, as exemplified in Figure 2. Fig. 4 shown.

[0050] The first surface 1a of the carrier plate 1 can, for example, be a flat surface, as in Fig. Figure 3 is shown schematically only. Optionally, one or more recesses or projections (not shown) can be provided on the first surface 1a. The second surface 1b of the support plate 1 can, for example, be a flat surface, as shown in Figure 3. Fig. Figure 3 is shown schematically only. Optionally, one or more recesses or projections (not shown) may be provided on the second surface 1b.

[0051] The support plate 1 is made of a mechanically rigid material. For example, the support plate 1 can be made of a metal material.

[0052] The friction lining 2 is designed to come into contact with the disc 210 in order to apply a frictional force to the disc 210. The friction lining 2 therefore has a first surface or contact area 21a. The friction lining 2 is, as shown in the Fig. 2 and Fig. Figure 3 shows the friction lining 2 arranged on the first surface 1a of the carrier plate 1. The contact surface 21a of the friction lining 2 faces away from the carrier plate 1.

[0053] As in Fig. As shown in Figure 3, the friction lining 2 has a friction material layer 21 and a backing layer 22.

[0054] The friction material layer 21 has the friction or contact surface 21a. The friction material layer 21 can be made of any known friction material suitable for use in a friction lining of a disc brake. The thickness t21 of the friction material layer 21a with respect to a friction unit thickness direction T1 can, for example, be in a range between 8 mm and 12 mm.

[0055] The backing layer 22 is bonded to or integrally formed with the friction material layer 21 and is positioned on a side of the friction material layer 21 facing away from the contact surface 21a. The backing layer 22 can, for example, have a thickness t22 in a range between 1 mm and 3 mm. The backing layer 22 generally serves as a damping layer and can therefore be made of a material composition that exhibits higher elasticity than the friction material layer 21. The material composition of the backing layer 22 can, for example, have the same components as the friction material layer 21, but in different percentages, or one or more components can be replaced by different components.In general, the backing layer 22 can comprise one or more of the following components: acrylic fibers, aramid fibers, inorganic material, rubber powder, rubber beads, binders and adhesives, nitrile rubber, ethylene propylene rubber, styrene-butadiene rubber.

[0056] As further in Fig. As shown in Figure 3, the underlay layer 22 comprises an inner surface 22a which is oriented opposite to the contact surface 21a. The underlay layer 22 is connected to the carrier plate 1 via the inner surface 22a, for example by means of an adhesive layer 5 ( Fig. 4) The underlay layer 22 and the friction material layer 21 can each have a perimeter at their interface that is shaped and dimensioned accordingly. As exemplified in Fig. As shown in Figure 2, the friction lining 2 can have a substantially rectangular circumference. For example, the circumference of the friction lining 2, corresponding to the circumference of the underlay layer 22, can have two opposite long or first sides 24 extending along the friction unit circumferential direction C1, and two opposite second or short sides 26 extending along a friction unit radial direction R1. The friction unit circumferential direction C1 and the friction unit radial direction R1 extend transversely to each other. The friction unit thickness direction T1 extends transversely to the friction unit circumferential direction C1 and the friction unit radial direction R1. As exemplified in Figure 2, the friction lining 2 can have a substantially rectangular circumference. Fig. As shown in Figure 2, the long sides 24 can be curved, e.g. convexly curved.

[0057] As in Fig. 3 visible and in Fig. Figure 4, shown in more detail, shows that the underlay layer 22 has at least one slot 3 formed in the inner surface 22a. As shown in the Fig. 3 and Fig. As shown schematically in Figure 4, the depth d3 of the slot 3 is less than the thickness t22 of the backing layer 22. The depth of the slot 3 can, for example, be in a range between 0.8 mm and 3 mm, preferably between 0.8 mm and 2 mm. A width w3 ( Fig. 2) The width of the slot 3 can, for example, be in a range between 3 mm and 10 mm, preferably between 5 mm and 7 mm. The slot 3 can, for example, have a rectangular cross-section, a triangular or trapezoidal cross-section, a U-shaped cross-section, or the like.

[0058] As in Fig. As shown schematically in Figure 4, the slot 3 forms a cavity or empty space extending between the first surface 1a of the carrier plate 1 or, if present, the adhesive layer 5. Alternatively, the slot 3 is filled with a filler material 4, as shown in Figure 4. Fig. Figure 5 shows a schematic representation. The filler material 5 can generally be a material that is mechanically softer than the backing layer 22. For example, the filler material 4 can be an elastically deformable material or a plastic material, such as a paste. The filler material 4 can, for example, have one or more of the following properties: a bulk modulus that is at least 30% smaller than that of the backing layer 22; a Poisson's ratio that is at least 10% larger than that of the backing layer 22; an elastic modulus that is at least 20% smaller than that of the backing layer 22; a density that is at least 20% smaller than that of the backing layer 22. According to the invention, the filler material 4 contains or consists of a phenolic resin, expanded polystyrene, wood fibers, or rubber. It is also possible that the adhesive material of the adhesive layer 5 can form the filler material 4.

[0059] As exemplified in Fig. As shown in Figure 2, the underlay layer 22 can comprise more than one slot 3, e.g., three slots 3 extending parallel to each other. Fig. The slots 3 are shown in dashed lines, since... Fig. Figure 2 shows a top view of the friction surface 21a. As exemplified in Fig. As shown in Figure 2, the slots 3 can be spaced apart from each other in the circumferential direction C1 of the friction unit and can extend along the radial direction R1 of the friction unit. As further shown in Fig. As shown in Figure 2, the slots 3 can extend between and terminate on the opposite long sides 24 of the circumference of the underlay layer 22. However, the invention does not extend to the number, positioning, and orientation of the slots 3. Fig. The 3 slots shown are limited to 3, and many variations are possible, as shown below with reference to the following. Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17, Fig. 18, Fig. 19 to Fig. 20 will be explained in more detail. Fig. 2. Instead of three slots 3, there can also be only one slot 3, two slots 3 or more than three slots 3.

[0060] With renewed reference to Fig. 1. When an external force is applied to the friction lining 100 to press the friction lining 2 against the disc 210, the friction lining 100 can begin to vibrate. Vibrations are caused on the one hand by the relative movement between the disc 210 and the friction lining 100 and can on the other hand even be promoted by an uneven pressure distribution over the friction surface 21a. Fig. Figure 2 shows an example of a friction unit 100, which is advantageously used as the first friction unit 100A in Fig. 1 can be used. Therefore, it is pushed by the piston 215 towards the disk 210. As in Fig. As shown schematically in Figure 2, the piston 215 applies force primarily in a central area of ​​the friction unit 100, which can lead to an uneven pressure distribution. The vibrations of the friction unit 100 can cause squeaking noises, for example, in a frequency range between 1 kHz and 16 kHz.

[0061] The underlay layer 22 helps to dampen the vibrations of the friction lining 2. By providing at least one slot 3, e.g. three slots 3, as in Fig. As shown in Figure 2, the underlay layer 22 is locally mechanically weakened. This allows the friction material layer 21 to deform further in the areas where a slot 3 is formed. Consequently, pressure peaks in the friction surface 21a are reduced when the friction unit 100 is pressed against the disc 210, and this in turn also reduces squeaking noises. Since the slots 3 are formed in the underlay layer 22, i.e., beneath the friction material layer 21, they are not exposed to wear or dirt. Therefore, it is possible to provide the contact surface 21a of the friction material layer 21 as a continuous surface with a flat main section 21p. The main section 21p is in Fig. 2 schematically indicated by a dashed line. For example, the main section 21p can form at least 85%, preferably 95%, of the area of ​​the contact surface 21a. In particular, if the main section 21p is provided as a flat, continuous surface, there are no slots in the main section 21p of the contact surface 21a. Optionally, however, a chamfer 21C can be formed in an end region of the contact surface.

[0062] As exemplified in Fig. 2 and also in the Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. As shown in Figure 11, the slot 3 or slots 3 can extend between opposing sections 24, 26 of a circumference of the underlay layer 22. However, the invention is not limited to this. In general, the slot 3 can terminate at a circumference of the underlay layer 22. For example, a slot 3 can be provided that extends between the circumference and another slot 3, as shown in Figure 11. Fig. Figure 9 shows schematically. Alternatively, the slot 3 can also end at the circumference of the backing layer 22 and terminate within the backing layer 22. Furthermore, it is also possible for a slot 3 to extend at a distance from the circumference of the backing layer 22, that is, the slot 3 can extend completely within the backing layer 22, as exemplified in the Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17, Fig. 18, Fig. 19 to Fig. 20 are shown. It is also possible to combine any of these variants.

[0063] The Fig. 6, Fig. 7 to Fig. Figure 8 shows friction units 100, which are advantageously used as first friction units 100A in the brake caliper 200. Fig. 1 can be used. That is, they can be moved by piston 215.

[0064] As exemplified in Fig. As shown in section 6, the underlay layer 22, unlike Fig. 2 also include a slot 3 extending along the circumferential direction C1 of the friction unit between the opposite short sides 26. Fig. Figure 6 shows only a single slot 3 as an example, but more than one slot 3 may also be provided.

[0065] Fig. Figure 7 shows an example of a friction unit 100 in which the underlay layer 22 has a slot 3 extending along the friction unit radial direction R1 between the opposite long sides 24 and a slot 3 extending along the friction unit circumferential direction C1 between the opposite short sides 26, wherein the slots 3 intersect each other, e.g. in a central section of the inner surface 22a of the underlay layer 22.

[0066] In the following, a slot 3 extending along the circumferential direction C1 of the friction unit can also be referred to as a tangential slot 3, and a slot extending along the radial direction R1 of the friction unit can also be referred to as a radial slot 3.

[0067] Fig. Figure 8 shows an example of a friction unit 100, which differs from that of Fig. 7 differs only in that two tangential slots 3 are provided which extend between the opposite short sides 26.

[0068] The Fig. 9, Fig. 10 to Fig. Figure 11 shows friction units 100, which are advantageously used as second friction units 100B in the brake caliper 200 of Fig. 1 can be used. That is, they can be pressed against the disk 210 by the second housing section 205B, e.g. by its fingers 205F.

[0069] As exemplified in Fig. As shown in Figure 9, the friction unit 100 can have two slots 3 extending along the friction unit radial direction R1 between the opposite long sides 24. The slots 3 are spaced apart in the friction unit circumferential direction C1 so that they are positioned in end regions of the friction lining 2 facing the respective short sides 26. Therefore, the slots 3 are positioned in the area where the pressure force of the fingers 205F is applied to the friction unit 100. Thus, they can help to reduce pressure peaks more efficiently.

[0070] Fig. 10 shows another friction unit 100, which is the one from Fig. 9 corresponds, wherein a tangential slot 3 is additionally provided with each of the radial slots 3, each tangential slot 3 extending between the respective radial slot 3 and the adjacent short side 26 of the circumference of the underlay layer 22. Although not shown, more than one tangential slot may be provided between each radial slot 3 and the immediately adjacent short side 26.

[0071] Fig. 11 shows another friction unit 100, which is the one from Fig. 9 corresponds to a pair of radial slots 3 being provided in each end region adjacent to the short sides 26.

[0072] A slot 3, which ends at the circumference of the underlay layer 22, can, for example, be configured as in Fig. 12 schematically depicted forms. As in Fig. As shown in Figure 12, a ridge 30 can be placed on the first surface 1a of the carrier plate 1. The ridge 30 acts as a mask. When the underlay 22 is applied to the carrier plate 1, e.g., pressed onto it, the ridge 30 is pressed into the underlay 22, so that the slot 3 is formed where the ridge 30 is positioned. The ridge 30 is then removed, e.g., by pulling it out from between the underlay 22 and the carrier plate 1, as shown in Figure 12. Fig. 12 indicated by the arrow P30.

[0073] As mentioned above, the Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17, Fig. 18, Fig. 19 to Fig. 20 friction units 100, in which the underlay layer 22 has at least one slot 3 which extends spaced apart from the circumference of the underlay layer 22.

[0074] The Fig. 13, Fig. 14, Fig. 15, Fig. 16 to Fig. Figure 17 shows friction units 100, which are advantageously used as first friction units 100A in the brake caliper 200. Fig. 1 can be used. That is, they can be moved by piston 215.

[0075] Fig. Figure 13 shows an example of a friction unit 100 in which the underlay layer 22 comprises a single radial slot 3 located in a central area between the short sides 26 of the circumference. Instead of just one radial slot 3, more than one radial slot 3 can be provided in the central area, e.g., two slots 3, as shown in Fig. 14 shown, or three slots, as in Fig. Figure 15 shows that all slots can be formed such that they extend completely within the backing layer 22, e.g., beginning and ending within the backing layer 22. Alternatively, one or more of a plurality of slots can end at the perimeter of the backing layer 22. For example, ... Fig. 15 a configuration in which two radial slots 3 are provided which extend completely within the underlay layer 22, and a radial slot 3 is positioned between these radial slots 3 and extends between the long sides 24.

[0076] Fig. Figure 16 shows a friction unit 100 similar to the one from Fig. 7, with the difference that the radial slot 3 ends at a distance from the long sides 24 and the tangential slot 3 ends at a distance from the short sides 26. It is also possible that one of the radial or the tangential slot 3 extends between the short or the long sides 24, 26.

[0077] Fig. Figure 17 shows an example of a friction unit 100 in which the underlay layer 22 has a radial slot 3 extending between the long sides 24 of the circumference and two tangential slots 3 that cross the radial slot 3 and terminate spaced apart from both short sides 26.

[0078] The Fig. 18, Fig. 19 to Fig. Figure 20 shows friction units 100, which are advantageously used as second friction units 100B in the brake caliper 200. Fig. 1 can be used. That is, they can be pressed against the disk 210 by the second housing section 205B, e.g. by its finger 205F.

[0079] Fig. 18 shows a friction unit 100, which is made of Fig. 11 is similar. In the example of Fig. 18 A pair of radial slots 3 is provided in each end region adjacent to the short sides 26, each pair having a first slot extending between the long sides 24 and a second slot terminating spaced apart from both long sides 24. As exemplified in Fig. As shown in Figure 18, the second slot can be arranged between the first slot and the adjacent short side 26.

[0080] Fig. Figure 19 shows an example of a friction unit 100 in which the underlay layer 22 has two radial slots 3, each of which is arranged in the end region adjacent to the short sides 26, wherein each radial slot 3 is crossed by a tangential slot 3 which ends spaced apart from the adjacent short side 26 and the adjacent radial slot 3.

[0081] Fig. Figure 20 further shows a friction unit 100, which is made of Fig.19 corresponds, with the only difference being that each radial slot 3 is provided with two tangential slots 3.

[0082] A slot 3, extending at a distance from the perimeter of the underlay 22, can be formed, for example, by placing or applying the filler material 4 to the first surface 1a of the carrier plate 1 and then applying the underlay 22 to the carrier plate 1. For example, the underlay material can be pressed onto the carrier plate 1 so that the slot 3 is formed where the filler material 4 is placed. REFERENCE MARK LIST 1 carrier plate 1a first surface of the carrier plate 1b second surface of the carrier plate 2 friction lining 2a Friction surface of the friction lining 3 slots 4 Filling material 5 adhesive layers 15 Main section of the carrier plate 16 guide sections of the carrier plate 21a Contact surface 21p Main section of the contact surface 22a inner surface 24 first or long pages 26 second or short pages 30 Bridge 100 friction units 100A first friction unit 100B second friction unit 200 brake calipers 202nd passage 205 carriers 205A first section of the carrier 205B second section of the carrier 205C Bridge 206 bore 210 disc 210a,b Friction surfaces of the disc 300 disc brake A axial direction C1 Friction unit circumferential direction d3 Depth of the slot A210 axis of rotation of the disc R radial direction R1 Friction unit radial direction T1 Friction unit thickness direction t21 Thickness of the friction material layer t22 Thickness of the underlay layer w3 Width of the slot

Claims

Friction unit (100) for a disc brake (300) of a vehicle, comprising: a carrier plate (1); and a friction lining (2) with a friction material layer (21) having a contact surface (21a) for contacting a disc (310), and a backing layer (22) having an inner surface (22a) oriented opposite to the contact surface (21a) and connected to the carrier plate (1), wherein the backing layer (22) has at least one slot (3) formed in the inner surface (22a) and forming a cavity, wherein the backing layer (22) has a predetermined thickness (t22), and wherein the at least one slot (3) has a depth (d3) that is less than the thickness (t22) of the backing layer (22). Friction unit (100) according to claim 1, wherein the at least one slot (3) terminates at a circumference of the underlay layer (22). Friction unit (100) according to claim 2, wherein the at least one slot (3) extends between opposing sections (24, 26) of a circumference of the underlay layer (22). Friction unit (100) according to claim 1, wherein the at least one slot (3) extends spaced apart from a circumference of the underlay layer (22). Friction unit (100) for a disc brake (300) of a vehicle, comprising: a carrier plate (1); and a friction lining (2) with a friction material layer (21) having a contact surface (21a) for contacting a disc (310), and a backing layer (22) having an inner surface (22a) oriented opposite to the contact surface (21a) and connected to the carrier plate (1), wherein the backing layer (22) has at least one slot (3) formed in the inner surface (22a), wherein the backing layer (22) has a predetermined thickness (t22), and wherein the at least one slot (3) has a depth (d3) that is less than the thickness (t22) of the backing layer (22), wherein the at least one slot (3) is filled with a filler material (4), and wherein the filler material (4) contains or consists of a phenolic resin, expanded polystyrene, wood fibers or rubber. Friction unit (100) according to claim 5 wherein the filling material (4) has one or more of the following properties: a compression modulus that is at least 30% smaller than that of the backing layer (22); a Poisson's ratio that is at least 10% larger than that of the backing layer (22); a modulus of elasticity that is at least 20% smaller than that of the backing layer (22); a density that is at least 20% smaller than that of the backing layer (22). Friction unit (100) according to one of the preceding claims, wherein the contact surface (21a) of the friction material layer (21) is a continuous surface with a flat main section (21p). Brake caliper (200) for a disc brake (300) of a vehicle, comprising: a carrier (205); and a friction unit (100) according to one of the preceding claims, which is movably guided within the carrier (205) along an axial direction (A) or is fixed within the carrier (205).

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