Wheel brake device for a vehicle, vehicle and method for manufacturing the wheel brake device

Abstract

The invention relates to a wheel brake device (1) for a vehicle (2), comprising a brake disc (3) and at least one brake pad (4). According to the invention, a friction ring (5) of the brake disc (3) and the at least one brake pad (4) each have several resonator bores (6), each of which is designed as a blind bore, wherein an opening of the respective resonator bore (6) is arranged on a friction surface (7). Furthermore, the invention relates to a vehicle (2) with at least one such wheel brake device (1) and a method for manufacturing the wheel brake device (1).

Description

[0001] The invention relates to a wheel brake device for a vehicle according to the features of the preamble of claim 1, a vehicle and a method for manufacturing the wheel brake device.

[0002] As described in DE 199 03 757 A1, a method and a device for reducing or avoiding the noise generation of friction brakes and friction clutches are known from the prior art.

[0003] EP 0 962 013 B1 describes a λ / 4 absorber with several tubular λ / 4 resonators for sound absorption.

[0004] The invention is based on the objective of providing a wheel brake device for a vehicle that is improved compared to the prior art, a vehicle that is improved compared to the prior art, and a method for manufacturing a wheel brake device that is improved compared to the prior art.

[0005] The problem is solved according to the invention by a wheel brake device for a vehicle with the features of claim 1, a vehicle with the features of claim 8 and a method for manufacturing a wheel brake device with the features of claim 9.

[0006] Advantageous embodiments of the invention are the subject of the dependent claims.

[0007] A wheel brake device for a vehicle comprises a brake disc and at least one brake pad or, advantageously, several brake pads.

[0008] According to the invention, a friction ring of the brake disc and the at least one or respective brake pad each have several resonator bores, each of which is designed as a blind hole bore, wherein an opening of the respective resonator bore is arranged on a friction surface.

[0009] It is specifically provided that the at least one or each brake block has a carrier and a brake lining arranged thereon with the friction surface, wherein the resonator bores in the at least one or each brake block extend from the friction surface through the brake lining and into the carrier.

[0010] The brake disc, for example, is designed as an internally ventilated brake disc with two lateral friction ring sections, each with a friction surface. Cooling fins are arranged between these two friction ring sections, connecting them to each other. The resonator bores in the friction ring extend from the respective friction surface, through the respective lateral friction ring section, and into one of the cooling fins.

[0011] For example, two or at least two resonator bores extend into the same cooling fin, with one resonator bore originating from the friction surface of one friction ring part and the other resonator bore originating from the friction surface of the other friction ring part. The two resonator bores 6 extending into the same cooling fin 11 are thus configured in opposite directions. For example, at least one resonator bore, or two resonator bores (particularly in opposite directions as described), or more than two resonator bores can extend into several or all cooling fins.

[0012] It is specifically designed that the cooling fins are oriented at an angle to the mutually facing inner surfaces of the friction ring parts and / or at an angle to the friction surfaces of the friction ring parts. This allows for the formation of resonator bores with a greater bore depth. Furthermore, the resulting larger surface area of ​​the cooling fins allows for greater heat dissipation, thus improving cooling functionality.

[0013] It is specifically intended that the resonator bores have different bore depths. In particular, it is intended that the resonator bores in at least one or each brake pad have different bore depths and / or that the resonator bores in the friction ring of the brake disc have different bore depths.

[0014] It is specifically provided that the resonator bores in the at least one or each brake pad have a shallower bore depth than the resonator bores in the friction ring of the brake disc, i.e., it is specifically provided that the resonator bore with the shallowest bore depth in the friction ring of the brake disc is deeper than the resonator bore with the greatest bore depth in the at least one or each brake pad.

[0015] It is specifically designed that the resonator bores in the friction ring of the brake disc and / or in at least one brake pad are oriented at an angle to the friction surface, i.e., not perpendicular to the friction surface, but at an angle deviating from the vertical. The angles of the resonator bores can vary, and the resonator bores can be oriented at an angle in different directions.

[0016] The angle of each resonator bore can be chosen arbitrarily. It is specifically selected so that the resonator bore can be formed as a blind hole in the friction ring of the brake disc or in the brake pad, with the specified bore depth, as described. The angled orientation allows for the formation of deeper resonator bores, thus ensuring that the specified bore depth is achieved. In the brake disc, this is further facilitated by the angled orientation of the cooling fins, into which the resonator bores project, as described above.

[0017] This makes it possible, in particular, to keep the dimensions of the brake disc and the brake pad constant, i.e., the dimensions, in particular the thickness and diameter of the brake disc and in particular the thickness, brake lining thickness and outer dimensions of the brake pad, can advantageously correspond to the dimensions of a conventional brake disc and a conventional brake pad previously used in a wheel brake device, so that these conventional components in the wheel brake device can be easily replaced by the brake disc and brake pad of the solution according to the invention without additional modifications, in order to form the wheel brake device according to the invention.

[0018] A vehicle according to the invention has at least one such wheel brake device, preferably at least two such wheel brake devices on the same axle or two such wheel brake devices on several or all axles.

[0019] In a method according to the invention for manufacturing the wheel brake device, natural frequencies are determined for a non-inventive wheel brake device comprising a brake disc and at least one brake pad that do not yet have resonator bores. From the determined natural frequencies, the required bore depths for the resonator bores are calculated, and the resonator bores with the determined bore depths are formed in the friction ring of the brake disc and / or at least one identical brake disc and in at least one respective brake pad and / or in at least one identical brake pad. The determination of the natural frequencies and the corresponding bore depths for the resonator bores thus does not need to be repeated for each identical brake disc and brake pad; instead, they are expediently determined only once and then used for the identical brake discs and brake pads.

[0020] The described solution provides, in particular, a wheel brake-integrated resonator for the direct minimization of noise emission in wheel brake devices.

[0021] In friction-based wheel brake systems, noise is generated when the brake pad contacts the friction ring of the brake disc. This noise is commonly known as brake squeal. The noise is particularly noticeable in the NVH (noise, vibration, and harshness) range of higher frequencies, for example, from approximately one kilohertz upwards. To minimize these frequencies, the described solution integrates a resonator into the wheel brake system. In one embodiment, as described in the method above, an existing wheel brake system that does not yet have the resonator bores is examined for its natural frequencies, and these natural frequencies are determined. Subsequently, the brake disc and the at least one brake pad are designed in the described manner, i.e.,The resonator bores are designed in such a way that these natural frequencies are specifically minimized with the resonator, thereby significantly increasing braking comfort.

[0022] The described solution reduces the noise generated by the friction pairing of the brake disc's friction ring and the brake pad's lining by means of a λ / 4 resonator (also known as a quarter-wave resonator). In one possible embodiment, as described in the method above, the existing wheel brake assembly, which does not yet have the resonator bores, is examined to determine the position of its natural frequencies. Typical positions of these natural frequencies are at 1 kHz, 2 kHz, and 5 kHz. The wavelengths are determined according to the physical properties of sound speed and frequency. These wavelengths are then used to create the resonator bores in the wheel brake assembly as described, in the form of blind holes.

[0023] It is specifically intended that the resonator bores are positioned in the friction ring of the brake disc and in the at least one or each brake pad, particularly in its brake lining and carrier, according to their bore depth and vibration source. To compensate for manufacturing variations and wear, the number of resonator bores is advantageously varied according to their bore depth, as described above. This allows for resonance around the natural frequencies, permitting a tolerance.

[0024] The resonator bores for low frequencies, which require a greater bore depth, are preferably formed in the friction ring of the brake disc, and the resonator bores for high frequencies, which require a shallower bore depth and thus less space, are preferably formed in at least one or each brake pad, in particular in its brake lining and backing plate. As described above, all resonator bores are open towards the excitation side, i.e., towards the friction surface.

[0025] The described solution is easy to implement and has a simple design, differing from conventional wheel brake devices only by the additional resonator bores. No further modifications to the wheel brake device or the vehicle, particularly its braking system, are required. The described solution can therefore also be used with existing braking systems, for which, advantageously, only the existing brake disc and brake pads on the respective wheel brake device need to be replaced with the brake disc and brake pads of the solution according to the invention.

[0026] The described solution makes it possible to minimize multiple natural frequencies, in particular through the above-described formation of resonator boreholes with different borehole depths, especially those adapted to the different natural frequencies.

[0027] The solution according to the invention can also depict a variation of an existing wheel brake device.

[0028] The described solution, in particular the described design of resonator bores with different borehole depths, also takes into account wear and thus a detuning of the resonance system, which is caused in particular by a decreasing borehole depth of the resonator bores due to the wear of the respective friction surface.

[0029] A particular advantage of the described solution is its passive operating principle, for which no control is required.

[0030] The described solution is very cost-effective and applicable in large-scale production.

[0031] The described solution can be adapted to all braking systems based on the friction principle.

[0032] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0033] This shows: Fig. 1 schematically a cross-section of a brake disc of a wheel brake device for a vehicle, Fig. 2 schematically a cross-section of a brake pad of the wheel brake device, Fig. 3 schematically another cross-section of the brake pad with a Fig. 2 aligned cutting plane, and Fig. 4 schematically a vehicle with at least one wheel brake device with the in the Fig. 1 to 3 components shown.

[0034] Corresponding parts are marked with the same reference symbols in all figures.

[0035] Based on the Fig. Sections 1 to 4 below describe a wheel brake device 1 for a vehicle 2, a vehicle 2 with at least one such wheel brake device 1 and a possible method for manufacturing the wheel brake device 1.

[0036] An embodiment of the wheel brake device 1 according to the invention relates in particular or exclusively to a brake disc 3 and at least one brake pad 4, expediently several brake pads 4, of the wheel brake device 1, i.e. advantageously, the brake disc and at least one or each brake pad of an existing non-inventive wheel brake device can be replaced by the brake disc 3 and the at least one or each brake pad 4 of the inventive solution described in more detail below, in order to thereby form the wheel brake device 1 according to the invention from the non-inventive wheel brake device, in particular without further modifications to the existing wheel brake device.

[0037] The vehicle 2 has at least one such wheel brake device 1 as described in more detail below, but preferably at least two such wheel brake devices 1 on the same axle or two such wheel brake devices 1 on several or all axles.

[0038] The wheel brake device 1 described here has the brake disc 3 and at least one brake pad 4 or, advantageously, several brake pads 4.

[0039] Fig. Figure 1 shows an example of a schematic cross-sectional view of the brake disc 3. Fig. 2 and Fig. Figure 3 shows exemplary schematic cross-sectional representations of the brake pad 4 in two different section planes. Fig. Figure 4 shows a purely schematic representation of the vehicle 2 with the brake disc 3 and the wheel brake device 1 having at least one brake pad 4.

[0040] A friction ring 5 of the brake disc 3 and the at least one or respective brake pad 4 each have several resonator bores 6, each of which is designed as a blind bore, wherein an opening of the respective resonator bore 6 is arranged on a friction surface 7.

[0041] The at least one or each brake pad 4 has a carrier 8 and a brake lining 9 arranged thereon with the friction surface 7. The resonator bores 6 in the at least one or each brake pad 4 extend from the friction surface 7 through the brake lining 9 and into the carrier 8.

[0042] In the illustrated example, the brake disc 3 is designed as an internally ventilated brake disc 3 with two lateral friction ring sections 10, each having a friction surface 7. Cooling fins 11 are arranged between these two friction ring sections 10, connecting the friction ring sections 10 to each other. The resonator bores 6 in the friction ring 5 extend from the respective friction surface 7 through the respective lateral friction ring section 10 into one of the cooling fins 11. In the illustrated example, two or at least two resonator bores 6 extend into the respective cooling fin 11, with one resonator bore 6 originating from the friction surface 7 of one friction ring section 10 and the other resonator bore 6 originating from the friction surface 7 of the other friction ring section 10. The two resonator bores 6 extending into the respective cooling fin 11 are thus configured in opposite directions.

[0043] In the illustrated example, the cooling fins 11 are each oriented obliquely relative to the mutually facing inner surfaces of the friction ring parts 10, which are aligned parallel to the friction surfaces 7 of the friction ring parts 10. Thus, the cooling fins 11 are also each oriented obliquely relative to the friction surfaces 7 of the friction ring parts 10. This allows for the formation of resonator bores 6 with a greater borehole depth. Furthermore, the resulting larger surface area of ​​the cooling fins 11 allows more heat to be dissipated to the external environment, particularly the ambient air, thereby improving cooling functionality.

[0044] As in the Fig. As shown schematically in Figures 1 to 3, it is specifically provided that the resonator bores 6 have different bore depths. In particular, it is provided that the resonator bores 6 in at least one or each brake block 4 have different bore depths, as shown in the figures. Fig. 2 and Fig. 3 shown, and the resonator bores 6 in the friction ring 5 of the brake disc 3 have different bore depths, as shown in Fig. 1 shown.

[0045] It is specifically provided that the resonator bores 6 in the at least one or respective brake pad 4 have a shallower bore depth than the resonator bores 6 in the friction ring 5 of the brake disc 3, i.e., it is specifically provided that the resonator bore 6 with the shallowest bore depth in the friction ring 5 of the brake disc 3 is deeper than the resonator bore 6 with the greatest bore depth in the at least one or respective brake pad 4.

[0046] In the advantageous embodiment shown schematically as an example, the resonator bores 6 in the friction ring 5 of the brake disc 3 and in the at least one or each brake pad 4 are each oriented obliquely to the friction surface 7, i.e., not perpendicular to the friction surface 7, but at an angle deviating from the vertical. The angles of the resonator bores 6 can be different, as is shown in particular in Fig. Figure 2 is shown as an example, and the resonator bores 6 can be inclined in different directions.

[0047] The angle of each resonator bore 6 can be chosen arbitrarily. It is specifically selected such that each resonator bore 6 can be formed as a blind hole in the friction ring 5 of the brake disc 3 or in the brake pad 4, with the specified bore depth, as described above. The angled orientation allows for the formation of deeper resonator bores 6, thus ensuring that the specified bore depth is achieved. In the brake disc 3, this is also facilitated by the angled orientation of the cooling fins 11, into which the resonator bores 6 project, as described above.

[0048] This makes it possible in particular to keep the dimensions of the brake disc 3 and the brake pad 4 constant, i.e. the dimensions, in particular the thickness and diameter of the brake disc 3 and the thickness, brake lining thickness and outer dimensions of the brake pad 4, can advantageously correspond to the dimensions of a conventional brake disc and a conventional brake pad previously used in a wheel brake device, so that these conventional components in the wheel brake device can be easily replaced by the brake disc 3 and the brake pad 4 of the solution according to the invention without additional modifications, in order to form the wheel brake device 1 according to the invention.

[0049] In the method for manufacturing the wheel brake device 1, natural frequencies are determined for a wheel brake device not according to the invention, comprising the brake disc and the at least one brake pad, which do not yet have resonator bores 6. From the determined natural frequencies, the required bore depths for the resonator bores 6 are calculated, and the resonator bores 6 with the determined bore depths are formed in the friction ring 5 of the brake disc 3 and in the at least one or each brake pad 4 and / or in the friction ring 5 of at least one identical brake disc 3 and / or in at least one identical brake pad 4. The determination of the natural frequencies and the corresponding required bore depths for the resonator bores 6 therefore does not need to be repeated for each identical brake disc 3 and each identical brake pad 4; instead, they are expediently determined only once and then used for the identical brake discs 3 and brake pads 4.

[0050] The described solution provides in particular a wheel brake-integrated resonator for the direct minimization of noise emission in wheel brake devices 1.

[0051] In wheel brake devices 1 based on the friction principle, noise is generated by the contact of the brake pad 9 with the friction ring 5 of the brake disc 3. This noise is known, for example, as brake squeal. The noise particularly affects a higher frequency NVH range, for example, from approximately one kilohertz. To minimize these frequencies, a resonator is integrated into the wheel brake device 1 by the described solution. In one embodiment, it is provided that, as described in the method above, an existing wheel brake device, which does not yet have the resonator bores 6, is examined for its natural frequencies and these natural frequencies are determined. Subsequently, the brake disc 3 and the at least one or each brake pad 4 are designed in the described manner, i.e.,The resonator bores 6 are designed in such a way that these natural frequencies are specifically minimized with the resonator, thereby significantly increasing braking comfort.

[0052] The described solution reduces the noise generated by the friction pairing of the friction ring 5 of the brake disc 3 and the brake pad 9 of the brake shoe 4 by means of a λ / 4 resonator. In one possible embodiment, as described in the method above, the existing wheel brake assembly, which does not yet have the resonator bores 6, is examined for the position of its natural frequencies. Typical positions of these natural frequencies are at 1 kHz, 2 kHz, and 5 kHz. The wavelengths are determined according to the physical properties of sound speed and frequency. These wavelengths are then introduced into the wheel brake assembly 1 as resonator bores 6 in the form of blind holes, as described. This minimizes higher frequencies in particular.

[0053] The following section briefly explains the physical principles using examples.

[0054] For the speed of sound c S applies: cs=λ*f

[0055] Here, λ is the wavelength and f is the frequency.

[0056] Formula (1) rearranged for the wavelength λ yields: λ=cs / f

[0057] The speed of sound c S is 340 m / s.

[0058] For example, one natural frequency f1 is at 1000 Hz, another natural frequency f2 is at 2000 Hz and another natural frequency f5 is at 5000 Hz.

[0059] Thus, from formula (2) a wavelength λ of 0.34 m results for the natural frequency f1 of 1000 Hz, a wavelength λ of 0.17 m for the natural frequency f2 of 2000 Hz and a wavelength λ of 0.068 m for the natural frequency f5 of 5000 Hz.

[0060] The λ / 4 resonator for the natural frequency f1 of 1000 Hz thus has a length of 0.34 m / 4 = 0.085 m = 8.5 cm. The resonator bores 6 for minimizing the natural frequency f1 of 1000 Hz must therefore each have a borehole depth of 8.5 cm.

[0061] The λ / 4 resonator for the natural frequency f2 of 2000 Hz thus has a length of 0.17 m / 4 = 0.0425 m = 4.25 cm. The resonator bores 6 for minimizing the natural frequency f1 of 1000 Hz must therefore each have a borehole depth of 4.25 cm.

[0062] The λ / 4 resonator for the natural frequency f5 of 5000 Hz thus has a length of 0.068 m / 4 = 0.017 m = 1.7 cm. The resonator bores 6 for minimizing the natural frequency f1 of 1000 Hz must therefore each have a borehole depth of 1.7 cm.

[0063] The basis of the resonator is therefore the quarter wavelength, known as the λ / 4 resonator.

[0064] It is specifically intended that the resonator bores 6 are provided in the friction ring 5 of the brake disc 3 and in the at least one or each brake pad 4, particularly in its brake lining 9 and carrier 8, according to their bore depth and vibration source. To compensate for manufacturing variations and wear, a variance in bore depth is advantageously introduced for the number of resonator bores 6, as described above. This variance in bore depth ensures robust application of the physical principles described above for the wheel brake device 1. This allows for resonance around the occurring natural frequencies, which permits a tolerance.

[0065] The resonator bores 6 for the low frequencies, which require a greater bore depth, are preferably formed in the friction ring 5 of the brake disc 3, and the resonator bores 6 for the high frequencies, which require a shallower bore depth and thus less space, are preferably formed in the at least one or each brake pad 4, in particular in its brake lining 9 and carrier 8. As described above, all resonator bores 6 are open towards the excitation side, i.e., towards the friction surface 7.

[0066] The described solution is easy to implement and has a simple design, differing from conventional wheel brake devices only by the additional resonator bores 6. No further modifications to the wheel brake device 1 or to the vehicle 2, in particular to its braking system, are required. The described solution can therefore also be used with existing braking systems, for which, advantageously, only the previously used brake disc and brake pads on the respective wheel brake device 1 need to be replaced by the brake disc 3 and brake pads 4 of the solution according to the invention.

[0067] The described solution makes it possible to minimize several natural frequencies, in particular through the above-described formation of resonator boreholes 6 with different borehole depths, especially adapted to the different natural frequencies.

[0068] The solution according to the invention can also depict a variation of an existing wheel brake device.

[0069] The described solution, in particular the described design of resonator bores 6 with different borehole depths, also takes into account wear and thus a detuning of the resonance system, which is caused in particular by a decreasing borehole depth of the resonator bores 6 due to the wear of the respective friction surface 7.

[0070] A particular advantage of the described solution is its passive operating principle, for which no control is required.

[0071] The described solution is very cost-effective and applicable in large-scale production.

[0072] The described solution can be adapted to all braking systems based on the friction principle. Reference symbol list 1 Wheel brake device 2 vehicles 3 brake disc 4 brake pads 5 friction ring 6 Resonator bore 7 friction surface 8 carriers 9 brake pads 10 Friction ring part 11 cooling fins QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 199 03 757 A1

[0002] EP 0 962 013 B1

[0003]

Claims

[1] Wheel brake device (1) for a vehicle (2), comprising a brake disc (3) and at least one brake pad (4), characterized by , that a friction ring (5) of the brake disc (3) and the at least one brake pad (4) each have several resonator bores (6), each of which is designed as a blind bore, wherein an opening of the respective resonator bore (6) is arranged on a friction surface (7). [2] Wheel brake device (1) according to claim 1, characterized by , that the at least one brake pad (4) has a carrier (8) and a brake lining (9) arranged thereon with the friction surface (7), wherein the resonator bores (6) in the at least one brake pad (4) extend from the friction surface (7) through the brake lining (9) and into the carrier (8). [3] Wheel brake device (1) according to one of the preceding claims, characterized by, that the brake disc (3) is designed as an internally ventilated brake disc (3) with two lateral friction ring parts (10), each having a friction surface (7), and cooling fins (11) arranged between them and connecting the friction ring parts (10) to each other, wherein the resonator bores (6) in the friction ring (5) extend from the respective friction surface (7) through the respective lateral friction ring part (10) into one of the cooling fins (11). [4] Wheel brake device (1) according to claim 3, characterized by , that the cooling fins (11) are each oriented obliquely to the mutually facing inner surfaces of the friction ring parts (10). [5] Wheel brake device (1) according to one of the preceding claims, characterized by , that - the resonator bores (6) have different borehole depths, and / or - the resonator bores (6) in at least one brake block (4) have different bore depths, and / or - the resonator bores (6) in the friction ring (5) of the brake disc (3) have different bore depths. [6] Wheel brake device (1) according to one of the preceding claims, characterized by , that the resonator bores (6) in at least one brake pad (4) have a shallower bore depth than the resonator bores (6) in the friction ring (5) of the brake disc (3). [7] Wheel brake device (1) according to one of the preceding claims, characterized by that the resonator bores (6) in the friction ring (5) of the brake disc (3) and / or in at least one brake pad (4) are each oriented at an angle to the friction surface (7). [8] Vehicle (2) comprising at least one wheel brake device (1) according to any of the preceding claims. [9] Method for manufacturing a wheel brake device (1) according to any one of claims 1 to 7, characterized by , that in a wheel brake device with a brake disc and at least one brake pad which do not yet have resonator bores (6), natural frequencies are determined, the required borehole depths of the resonator bores (6) are determined from the determined natural frequencies, and the resonator bores (6) are formed with the determined borehole depths in the friction ring of the brake disc and / or at least one identical brake disc and in the at least one brake pad and / or in at least one identical brake pad.

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