Brake disc protector

Abstract

The invention relates to a device forming a brake disc protector for a vehicle, comprising a central base ring (Cbr) securing the device forming the brake disc protector to a non-rotatable vehicle structural element (K), a blade-type envelope having a substantially circular general shape with a maximum angular extent of approximately 300°, the blade-type envelope extending from one end of the central base ring (Cbr) and comprising a first structure (Sbi) extending in a plane substantially perpendicular to an axis of revolution of the central base ring (Cbr), the first structure (Sbi) comprising a first series of blades (Bi), each blade (Bi) of the first structure (Sbi) extending radially over the angular extent of the blade-type envelope with an angle of inclination with respect to the plane in which the first structure (Sbi) extends.

Description

[0001] DESCRIPTION

[0002] TITLE: Brake Disc Protector

[0003] Technical field

[0004] The invention relates to systems for improving braking performance and reducing damage to the material of a brake disc during use in a vehicle and more specifically for improving cooling of the brake disc.

[0005] A particularly interesting application of the invention relates to a sudden braking condition, which can affect the property of the material which in turn will degrade the braking performance, in the event that the cooling is not sufficient.

[0006] Previous techniques

[0007] In the field of motor vehicles, in the case of disc braking, it is necessary to regulate the temperature of the brake disc, so that the braking quality is not degraded by excessive heating.

[0008] The brake disc reaches more than 600 degrees during a hard braking condition. Therefore, brake cooling performance is essential to determine the thermal load or critical temperature of the disc which can potentially affect the material property and the desired shape of the disc. This in turn will degrade the braking performance. To achieve the cooling performance criteria, the hot air from the disc must be exhausted at a rapid speed.

[0009] To protect the braking tracks of a disc brake disc from splashing water, mud or other, it is known to protect them by surrounding the disc with a "disc protector" but this degrades the cooling performance.

[0010] In US Patent 10,487,897, openings are formed on the main body of a brake dust cover to allow air to flow and cool the disc track, however the improvement in cooling performance remains limited with this solution.

[0011] Statement of the invention

[0012] Considering the above problems, it is desirable to provide a disc protector that ensures brake cooling performance with a lightweight structure.

[0013] One aspect of the present invention relates to a brake disc protector device for a vehicle, in particular for a motor vehicle, comprising: a) a central base ring securing the brake disc protector device to a non-rotating vehicle structural member, b) a blade-like casing having a substantially circular general shape having a maximum angular extent of approximately 300°, the blade-like casing extending from one end of the central base ring and comprising a first structure extending in a plane substantially perpendicular to an axis of revolution of the central base ring, the first structure comprising a first series of blades,each blade of the first structure extending radially over the angular extent of the blade-like shroud with an angle of inclination relative to the plane substantially perpendicular to an axis of revolution of the central base ring, and the first structure is secured to the central base ring. Thus, the extent of the blade-like shroud is adapted to provide a cutout over an angular portion of the circular area for a caliper gap. Furthermore, the first structure extends in a plane parallel to a brake disc track surface and due to the angle of inclination each blade of the first structure extends radially in a plane not parallel to the brake disc track surface so that they can expel hot air from the inner, or internal, track surface of the disc. This disc protector, which may also be one-piece, incorporating blade structures in front of the disc tracks,Allows the brake disc to cool more quickly, over a larger area and more efficiently. This means that hot air is no longer accumulated between the brake disc and the disc protector, thus no longer degrading the performance of the disc brake thanks to the blade structure design exposing more of the disc to the ambient air.

[0014] Advantageously, the blade-type casing comprises U-shaped profile arcs overhanging the central base ring and in each arc a first leg of the two parallel U-legs is part of the first structure, and preferably a blade is part of the first series of blades. Thus, the brake disc protector is designed to at least partially surround a brake disc, defining a volume in which the disc is located, partially enveloping it and covering the exposed regions of the disc to protect them.

[0015] Advantageously, each U-shaped profile arc of the blade-type envelope also comprises:

[0016] - a second branch of U which is a blade forming part of a second series of blades of a second structure extending in a plane parallel to the plane in which the first structure extends, each blade of the second structure extending radially with an angle of inclination different from zero with respect to the plane in which the second structure extends,

[0017] - a base of the U-shaped profile continuously connecting the first branch to the second branch is a connecting part forming part of the peripheral structure, the peripheral structure extends in a plane substantially perpendicular to the planes in which the first and second structures extend. Thus, the second structure extends substantially parallel to the brake disc track surface, and thanks to the angle of inclination its blades extend in a plane not parallel to the brake disc track surface so that they can expel hot air from the outer, or external, track surface of the disc.Thus designed, the first structure is located further inboard of the vehicle than the second structure and each second branch of the U-shaped profile arch is continuously attached to a blade of the first series by means of one of the connecting parts, the arch overhanging the central base ring.

[0018] Advantageously, the blades of the blade-type envelope are flat and / or helical, either to simplify manufacturing or to improve the evacuation of hot air.

[0019] Advantageously, the second set of blades includes more blades than the first set of blades, in order to better protect the internal disc track against splashes.

[0020] Advantageously, the blades of the blade-type casing are inclined relative to the plane in which the structure to which they belong extends by an angle of 30 to 60°, and preferably 45°, this inclination of the brake disc track surface improves the cooling efficiency.

[0021] Advantageously, the central base ring and / or the blade-type casing are made of metallic material or plastic material or ceramic material, so that they can withstand temperatures up to 300 “Celsius.

[0022] Advantageously, the blades forming part of a series of blades are regularly spaced angularly, and preferably the spacing between two blades forming part of a series of blades is in the range of 2 to 23 degrees in angle, in order to better expel hot air from the disc tracks.

[0023] Advantageously, the blades of the first series of blades are regularly spaced angularly, and preferably the maximum spacing between two blades of the first series of blades is approximately 2.8 degrees in angle, in order to better protect the disc against splashes, mud or the like.

[0024] Advantageously, the blade length of at least some of the blades of the blade-type shroud is greater than or equal to a brake disc track width, in order to maximize the cooling surface area on the brake disc track surface and such that in the presence of an arc, the arc surrounds the disc.

[0025] Advantageously, the blade-type envelope leaves a space of at least 1 millimeter, preferably at most 3 millimeters, with a brake disc track surface in order to better expel hot air from the disc track surface.

[0026] Advantageously, the second structure covers an angular extent less than the angular extent of the blade-type casing, partially overlapping the first structure of the blade-type casing, preferably its upper extent section, and preferably the angular extent of the second structure is at most 180 degrees, in order to optimize the weight by limiting the second structure to the necessary cooling area.

[0027] The subject of the invention is also a method of manufacturing a brake disc protector device according to any one of the preceding claims, characterized in that it comprises, in combination, the following steps: a) - forming a central base ring and a blade-type casing, preferably by stamping a metal plate or by means of a plastic injection molding process, or by means of a ceramic casting process, and b) - assembling the central base ring to the first structure of the blade-type casing, preferably by welding or brazing. This method does not require complex tooling and ensures the robustness of the disc protector thus manufactured.

[0028] The subject of the invention is also a disc brake assembly comprising a wheel assembly axle spindle, a caliper, a brake disc and a brake disc protector device according to the invention having the same qualities as mentioned above.

[0029] The subject of the invention is also a motor vehicle comprising at least one disc brake assembly according to the invention, the vehicle structural element being the axle spindle of a wheel assembly.

[0030] Brief description of the drawings

[0031] Other objects, characteristics and advantages of the invention will appear on reading the following description, provided solely by way of a non-limiting example, and made with reference to the appended drawing in which: [Fig 1] is a basic diagram showing the environment of a brake disc in a vehicle according to the prior art with a conventional disc protector; and [Fig 2a], [Fig 2b] and [Fig 2c] are schematic views of the disc, the caliper and the blades: top view, side view from the outside in the direction of the width of the vehicle, side view from the inside in the direction of the width of the vehicle; illustrating the position of the blades according to one embodiment of the invention, and [Fig 3] is a perspective view of the disc brake assembly illustrating the position of blades on each side of the disc in a preferred embodiment of the invention;and [Fig 4] is a side view of the disc brake assembly from inside in the width direction of the vehicle in a preferred embodiment of the invention; and [Fig 5] is a top view of the disc brake assembly in a preferred embodiment of the invention; and [Fig 6] is a perspective view of the blade-type shroud from outside in the width direction of the vehicle according to a preferred embodiment of the invention; and [Fig 7] is a perspective view of the blade-type shroud from outside in the width direction of the vehicle according to another embodiment of the invention; and [Fig 8a] is a schematic cross-sectional view of a portion of the disc protector according to a preferred embodiment of the invention and [Fig 8b] is a perspective view thereof; and [Fig 9a] and [Fig 9b] are perspective views of the disc brake assembly with and without the disc;and [Fig. 10] shows a comparison of near-wall fluid temperature between a conventional disc protector and the disc protector according to a preferred embodiment of the invention; and [Fig. 11] shows a comparison of heat transfer coefficient between a conventional disc protector and the disc protector according to a preferred embodiment of the invention.;

[0032] Throughout the text, directions and orientations refer to a direct orthonormal reference frame XYZ, where X is the longitudinal direction of the vehicle, Y is the transverse direction of the vehicle, pointing outwards from the vehicle and Z is the vertical direction pointing upwards. Throughout the description, the term "substantially" means that a slight deviation from a certain nominal position or orientation is permissible, for example "substantially vertical" means that a deviation of the order of 10° from a strictly vertical orientation is permissible in the context of the invention, and the term "approximately" implies a tolerance of 5% from the stated nominal value. For the sake of clarity, identical or similar elements are identified by identical reference signs in all figures.

[0033] Detailed description of at least one embodiment

[0034] As illustrated in [Fig 1], conventionally, in a vehicle, the disc brake, used while a vehicle is moving, comprises a brake disc D also called a disc brake rotor disposed on an inner diameter side of a rim R of a wheel and a caliper C which interposes and retains the brake disc D with the brake pads P. In such a disc brake assembly, a conventional, plate-shaped disc protector CDP is disposed adjacent to the brake disc D facing the inner surface, or track, of the disc brake rotor in the width direction of the vehicle and so as to overlap at least a portion of the disc brake rotor, as viewed from an axle direction of the wheel in an installed state where the disc protector is installed in the vehicle, in order to protect, for example, the disc from foreign matter such as dust, a small pebble and muddy water.A planar shape of the disc protector viewed across the width of the vehicle is typically a disc shape substantially concentric with the rotor or a sector shape with a cutout to provide a space for the caliper C.

[0035] Such a conventional disc protector creates inhomogeneity in the disc, especially between its distal track and its proximal track relative to the center of the concerned wheel axle, respectively also called outer track and inner track, significantly decreasing the overall heat transfer coefficient value of the inner track and also increasing the cooling constant, compared to a disc without a protector.

[0036] According to the invention, the brake disc protector comprises:

[0037] - a central base ring securing the brake disc protector device to a non-rotating structural element of the vehicle,

[0038] - a blade-like casing having a substantially circular general shape having a maximum angular extent of approximately 300°, in order to provide a cutout on an angular portion of the circular area for a caliper gap, the blade-like casing comprising a first structure extending substantially parallel to a brake disc track surface and comprising a first series of blades Bi, each blade of the first structure extending radially over the angular extent of the blade-like casing in a plane not parallel to the brake disc track surface and the first structure is secured to the central base ring.

[0039] The term blade refers to a wide, flat part used to push air, such as a propeller rotor or fan blade, and is used here as such to refer to an object that is flat, thin, and long, and by extension to a vane that is not necessarily flat.

[0040] The central base ring and / or the blade-like shell are made of metal, preferably aluminum or steel, or plastic that can withstand more than 300°C, or ceramic material. The central base may have the same characteristics with respect to the blade-like shell of maximum angular extent of approximately 300°, preferably 270°C, in order to provide a cutout on an angular portion of the circular area for a yoke gap.

[0041] In [Fig. 2a], the preferred embodiment with bilateral blade structures of the blade-type shroud is sketched with only one blade on each side, to illustrate this embodiment with a simplified view. Each blade of the blade-type shroud extends radially in a plane not parallel to the brake disc track surface Ti, Te of the brake disc D. The blade Bi extending laterally from the proximal track toward the interior of the vehicle illustrates the preferred orientation of the first series of blades Bi, also called inner blades Bi. The blade Be extending laterally from the distal track toward the outer periphery of the vehicle illustrates the preferred orientation of the second series of blades Be, also called outer blades Be.All blades in a series virtually intersect each other at the center of the axle stub, regardless of the orientation chosen, if they were connected to each other all the blades in each series of blades would form a surface of revolution, the axis of revolution being the axis passing through the center of the central base ring perpendicular to the track surfaces, a surface of revolution being a surface in Euclidean space created by rotating a curve (the generatrix) around a straight line in its plane (the axis).

[0042] Alternatively, the blade-type shroud may have only one set of blades and on the other side, in place of the other set of blades, there would be a flat plate parallel to the disc track, of generally circular shape having a maximum angular extent of approximately 300°, to provide a cutout over an angular portion of the circular area for a caliper gap, but the cooling performance would be reduced compared to the preferred embodiment.

[0043] Each blade of the blade-type shroud extends radially in a plane not parallel to the brake disc track surface, the main surface of the blade extending either perpendicular to the disc tracks, primarily for protection purposes, or inclined to the brake disc track surface, preferably at an angle of inclination Bsa of 30 to 60°, for protection and cooling purposes, and in particular 45° as shown herein, where each blade is inclined at an angle of 45 degrees to the track surface, positively or negatively, acting as disc vents. As illustrated below in Figure 3, both the inner and outer side blades are connected to each other using a connecting element on the periphery of the disc vents.The blade pitch and orientations may also be different for the first set of blades and the second set of blades provided that, in the same set, all blades extend radially at the same pitch angle, also called pitch orientation with sign, relative to the surface track.

[0044] As shown here, the preferred embodiment consists of blades symmetrical with respect to the plane of symmetry Ps which is the median plane of the disc tracks parallel to the disc tracks Ti, Te. Preferably, the blade edges and the disc surface should maintain one to three millimeters of tolerance space. This offset of 1 millimeter between the blades, more precisely between their edges, parallel to the disc tracks and close to the disc, and the respective track surface opposite them is shown in the figure relative to the proximal track Ti and the blade Bi and symmetrically on the other side between the blade Be and the distal track Te. This offset, of approximately 1 millimeter between the track surface and the blade edges and at least 3 millimeters between the disc circumference and the connecting parts, more generally delimits the limit of the arcs.The blades cut the hot air across the disc, so they need to be as close together as possible, so the gap G is necessary, but the smaller it can be, the more cooling is optimized. Shown here, as an example, the blade height Bh is 10 millimeters and their pitch height Bsh is 7.1 millimeters.

[0045] In Figures 2b [Fig. 2b] and 2c [Fig. 2c], side views from the outside in the width direction of the vehicle and a side view from the inside in the width direction of the vehicle, are illustrated the preferred blade stacking patterns, for the first series of blades in Figure 2c and for the second series of blades in Figure 2b, the blades Bi, Be being repeatedly distributed at small angular intervals so that they cover the entire track surface except for the angular section covered by the stirrup C. The inner blades Bi and / or outer blades Be are angularly and preferably regularly spaced, and preferably the maximum spacing between two blades in one of the first and / or second series is approximately 23 degrees in angle for cooling performance reasons. More precisely the maximum angle between two blades Bi, Be is a quarter of a quarter of a circle: 22.5°.Thus distributed in a dispersed manner, as shown here in Figure 2b for the outer blades Be, with an angular spacing Beas of 22.5° between consecutive outer blades Be. The blades allow a weight reduction and thus a reduction in fuel consumption since they reduce the weight of the unsprung mass of the vehicle, which will typically improve the way the vehicle rides and its handling. In a preferred embodiment, to improve cooling on the inner side, the inner blades Bi are distributed in a close manner, the inner blades being regularly spaced angularly with a maximum spacing between two blades of the first series of blades Bi of approximately 2.8 degrees in angle and more precisely with a spacing of 22.5° / (7 + l) allowing 7 inner blades Bi to be placed between the inner blades Bi which are extended by the connecting parts.Thus, distributed densely, as shown here in Figure 2c for the internal blades, with a Beas angular spacing of 2.8° between the Bi blades, the Bi blades act as a disc protector, for example in the event of splashing, which eliminates the need to provide a dedicated external fender since it covers the area projected onto the disc, and thus allowing a reduction in weight and thus a reduction in fuel consumption.

[0046] Preferably, both the inner blade length Bi and the outer blade length Be should be greater than or equal to the track width to achieve maximum efficiency over the disc track area.

[0047] In [Fig. 3] the perspective view of the disc brake assembly shows the caliper C, the axle spindle K of a wheel assembly, the disc having its outer race Te and the blade-like shell with its bilateral blade structures Bi, Be surrounding the disc, and having a substantially circular overall shape, including U-shaped profile arcs, at least partially surrounding the brake disc, with a maximum angular extent of approximately 300° to provide a cutout over an angular portion of the circular area for a caliper gap. Each blade Bi, Be of the blade-like shell extends radially in a plane not parallel to the brake disc race surface Ti, Te, and as a preferred embodiment illustrated herein, the two parallel U-shaped legs of the blade-like shell consist of blades only.In this image of a preferred embodiment, the three parts of the blade-type envelope are clearly visible:.

[0048] - a first structure Sbi defining a surface extending substantially parallel to the distal track surface Te of the brake disc, the first structure Sbi comprising a first series of blades Bi,

[0049] - a second structure Sbe defining a surface extending substantially parallel to the proximal track surface Ti of the brake disc, preferably the second structure Sbe comprising a second series of blades Be, the first structure Sbi corresponding to the proximal structure relative to the center of the wheel axle concerned, in other words, located further inward relative to the vehicle than the second structure Sbe,

[0050] - a peripheral structure Sp connecting the first structure Sbi to the second structure Sbe defining connecting portions whose surface is substantially perpendicular to the track surface Ti, Te of the brake disc and parallel to the local tangent to the disc D, each blade Be of the second series being continuously attached to a blade Bi of the first series by one of the connecting portions. In this figure, the second structure Sbe with its blades Be stacked on the upper half of the disc on the outer side is better shown, the second structure covering an angular extent less than the angular extent of the blade-type envelope due to the angular extent of the first structure, better visible in the following figure, and preferably the angular extent of the second structure is at most 180 degrees, overlapping the upper extent section of the first structure of the blade-type envelope.Here, the space between the two blades Be is 1 1 .25 degrees in angle.

[0051] The arrow represents the direction of rotation of the disc, known as counterclockwise rotation, and the dotted line represents the axis of rotation of the disc. The disc, as it rotates, will cause the air around it to spin with it. The spinning air receives heat from the disc and behaves like a warm blanket over the disc. This warm blanket of air dissipates much less heat to the surrounding air, acting as a thermal resistive layer. An effective solution is to disrupt this layer, so that fresh cold air from the environment can remove more heat from the disc. The blade design according to the invention prevents the air from spinning with the disc and therefore they act as airflow separators. The flow separation increases the turbulence in the airflow, which improves the mixing of cold and hot air. This in turn results in increased cooling performance.In a preferred embodiment of the invention illustrated here, the blades Bi are distributed densely on the inner side to have the functionality of a disc protector while, on the outer side, the blades Be are distributed dispersedly to focus only on the flow separation functionality. A rim, in particular a semi-openwork or solid rim, can also be added on this outer side.

[0052] [Fig 4] shows a side view of the disc brake assembly from inside the vehicle in the direction of the vehicle width, as from the center of the relevant wheel axle. Shown in this view are the axle stub K, the caliper C, the proximal or inner race Ti, and the inner blades Bi, here spaced regularly with a gap of 2.8° between each of them and covering the extent of 270°. In this embodiment, the total number of blades will be about 80 but it may vary with the configuration and design of the disc and the caliper. The arrow represents the direction of rotation of the disc.

[0053] In [Fig 5] are shown the disc C, the caliper C and the blade-type casing secured to the axle spindle K and the peripheral structure Sp consisting of connecting parts Bp connecting the first structure to the second structure acting as transverse fixings.

[0054] [Fig 6] shows a perspective view of the blade-type casing from the outside in the width direction of the vehicle in a preferred embodiment of the invention. The arrow represents the direction of rotation of the disc. The architecture of the blade-type casing consisting of three parts of the blade-type casing is clearly apparent as is the continuity between the first structure Sbi, the peripheral structure Sp and the second structure Sbe thanks to the blades Bi of the first structure Sbi connected via connecting parts Bp of the peripheral structure Sp to blades Be of the second structure Sbe. In this figure, the characteristic of lightness is clearly evident.

[0055] Alternatively, as shown in [Fig. 7], the blade-type shroud may comprise two sets of blades Bi Be, and one of them, preferably the inner blades Bi, is supported by a generally circular flat plate Fpi parallel to and facing the inner disc track Ti, with the same extent as the first set of blades Bi, with a maximum angular extent of approximately 300° to provide a cutout on an angular portion of the circular area for a caliper gap. Here, the flat plate Fpi and the inner blades Bi form the first structure Sbi. The flat plate Fpi acts as a circumferential peripheral cover of the inner blades Bi on the proximal side (relative to the center of the wheel axle) of the disc protector when assembled to the vehicle, thereby protecting the disc from splashing.The proximal end (relative to the center of the wheel axle) of the inner blades Bi is secured, preferably welded, to the flat plate. In this case the blades Bi are distributed in a regular angular manner but less densely than shown in the previous figures, for example with intervals of 1 1 ° between them like the outer blades Be. The arrow represents the direction of rotation of the disc. This variant provides better protection against splashes and improves robustness with respect to noise and vibration criteria. Furthermore, the parallel flat plate can be semi-perforated to improve cooling and weight without degrading the anti-splash efficiency.

[0056] In [Fig. 8a] is a schematic cross-sectional view of a portion of the disc protector according to a preferred embodiment of the invention illustrating the U-shaped arc and the attachment of the blades Bi of the first structure Sbi to the fixed central base ring Cbr. As shown there, the central base ring Cbr consists of a first annular plate, encircling the steering knuckle K and attached to the steering knuckle, with a projection consisting of a circumferentially laterally offset extension towards the wheel axle (when the disc protector is installed in the vehicle).This circumferentially offset extension, starting from the inner periphery (relative to the vehicle) of the first annular plate, consists of a second substantially vertical annular plate extended by a third substantially horizontal annular plate forming an L-shaped projection Cbr_Ls around the first annular plate, the diameter of the central base ring Cbr being at this end slightly larger than the diameter of the first annular plate and preferably covers the same angular extent as the extent of the blade-type envelope. The role of the horizontal annular plate is to be a lower base for retaining the inner blades Bi so that the width (extended in the Y direction, perpendicular to the disc surface) of this second annular plate is at least the blade width.The method for manufacturing such a brake disc protector device comprises, in combination, the following steps: a) - forming a central base ring Cbr and a blade-like casing, preferably by stamping a metal plate or by means of a plastic injection molding process, or by means of a ceramic casting process, and b) - assembling the central base ring Cbr to the first structure Sbi of the blade-like casing, the central base ring Cbr being for example welded or bolted, and / or preferably clamped onto the axle stub K.

[0057] The horizontal annular plate acts as a fixing plate holding the central ends of the inner blades Bi. Thus, in the first step, when the blades are separate parts of the central base ring Cbr, the central ends of the blades are attached to the central base ring, for example by resistance welding or brazing or gas-shielded metal arc welding. Preferably, diagonal slots are cut in the base ring to obtain the preferred inclination angle of 45°, then the first end of each of the blades Bi is slid into the slots and press-fitted, and the junctions are welded or brazed with heat to firmly secure the inner blades Bi on the central base ring Cbr.Then some of the blades, preferably one in 8, are approximately twice as long and bent into a U shape to create the arcs, or alternatively some of the blades Bi are fixed perpendicularly, by welding for example, to connecting parts Bp, themselves fixed perpendicularly, by welding for example, to external blades Be, to form the arcs. Alternatively, the manufacturing method may follow a sheet metal forming process, so that the central base ring Cbr and the blades are in one piece.In this variation, the L-shaped edge of the central base ring is extruded to the maximum required blade length (approximately twice the length of the inner blades) forming as a tube, the extruded region is cut into regular intervals equal to the required blade height (which are not necessarily all the same length, as explained previously for forming the arcs), and the blades are bent 90° radially outwards until they cover the required extent (the others are cut at their base), the base region of the blade is inclined to give the blade angle a 45° inclination, and the arcing process remains the same as stated previously, the disc protector being a single piece here.

[0058] In this image the U-shaped profile is clearly visible, the outer blades Be are overhanging and are held in place by the peripheral structure Sp at one of their ends. Each end of the outer blade Be opposite the connecting parts Bp is thus free, and is not connected to any other fasteners connecting them to the steering knuckle K. The stiffness of the U-shaped profile is proportional to the thickness of the blades. Therefore blades of appropriate thickness of at least 1 mm will withstand driving situations without vibrating. However, regardless of the blade thickness, the connecting parts Bp of U-shaped arches can be reinforced with transverse stiffeners to improve robustness and prevent vibrations at high vehicle speed. For example, as shown in the perspective view of [Fig.8b], the three free corners of consecutive arches are connected to each other using connecting metal sheets as transverse stiffeners S, while the fourth corner is fixed to the central base ring Cbr by default. In this case, this implies that the free ends of the internal blades Bi that are not part of the U-shaped arches are subjected to one of the transverse stiffeners S.

[0059] In the various images the blades of the blade-type casing are designed to be flat for better understanding of the drawings, but they can also be designed in a helical manner, like fins arranged in a spiral around an axis. Furthermore, in the presence of stiffeners, the connecting parts Bp can be more easily twisted or made not only perpendicular to the track surface Ti, Te of the brake disc but also perpendicular to the local tangent to the disc D, in order to improve cooling since the connecting parts Bp perpendicular to the track surface Ti, Te of the brake disc and parallel to the local tangent to the disc D slightly obstruct the air flow. In [Fig. 9a] is shown the disc assembly (without the caliper for clarity) comprising the disc D, the fixed steering knuckle K and the disc protector according to another embodiment of the invention.Figure 9b [Fig. 9b] is the same figure without the disc. In this embodiment of the invention, the second structure Sbe of the outer blades Be covers not only the upper half of the disc D but the entire extent, or angular arc, of the blade-type envelope, which means that the extent of the disc apart from the angular area remains open for the caliper C. The central base ring Cbr is fixed, encircling the steering knuckle K and attached to the steering knuckle.

[0060] [Fig. 10] shows the comparison of the near-wall fluid temperature in a case of use at a constant vehicle speed of 80 kmph, between a conventional disc protector CDP, in the left column, and the disc protector DPI according to the preferred embodiment of the invention (as in Figures 3 to 6), in the right column, for the inner track Ti in the first row, and for the outer track Te in the second row. It is clear that on the side of the inner track Ti the disc protector traps the hot air in the narrow gap (here 1 millimeter) between the disc protector and the disc track Ti. The arrow represents the direction of rotation of the disc.The blades are open to the ambient air and separate the hot air attached to the disc, so the near-wall air temperature drops in the range of 100°C to 135°C, and on the outer track side Te, in the absence of the disc protector part in the conventional CDP design, a uniformly distributed temperature of 135°C is observed, while, in the preferred embodiment DPI, the blades separate the hot air flow and help the cold ambient air to mix and reduce the near-wall air temperature to 100°C.

[0061] In [Fig. 1 1 ] the heat transfer coefficient (HTC) is compared, in a case of use at a constant vehicle speed of 80 kmph, between a conventional disc protector CDP (left column) and the disc protector DPI according to a preferred embodiment (as in Figures 3 to 6) of the invention (right column), with respect to the inner track Ti in the first line, and the outer track Te in the second line. The arrow represents the direction of rotation of the disc. On the side of the inner track, an HTC of about 75 W / (m 2 .K) is observed with the conventional CDP protector, while in the preferred DPI embodiment, the blades increase the HTC up to almost 100 W / (m 2.K) . This represents an improvement of approximately 25% in this region. On the outer track side, with the conventional CDP protector, the caliper itself acts as a major flow separator which itself improves the HTC in the lower half of the disc. Therefore, in the preferred DPI embodiment in which blades are present on the remaining region of the disc track, it is observed that thanks to the blades the HTC increases by 75 W / (m 2 .K) at 100 W / (m 2 .K) .

[0062] The disc is rotating (rotator) and the blades are static (stator), which creates a relative movement of the disc with respect to the blades, which is similar to the behavior of a disc kept static and blades as rotating parts, and in either case the blades behave like a fan in front of the disc. The brake cooling performance of the preferred embodiment according to the invention is also evaluated through the time constant, also called cooling constant. For example, in a case where the brake disc tracks are initialized at 600 °C and are allowed to cool down to 200 °C, the cooling time period from 555 °C to 200 °C is evaluated, and a difference of 80 seconds is obtained between the conventional disc protector housing and the preferred embodiment.

Claims

CLAIMS 1. A brake disc protector device for a vehicle, in particular for a motor vehicle, comprising: a) a central base ring (Cbr) securing the brake disc protector device to a non-rotating vehicle structural element (K), b) a blade-like casing having a substantially circular overall shape having a maximum angular extent of approximately 300°, the blade-like casing extending from one end of the central base ring (Cbr) and comprising a first structure (Sbi) extending in a plane substantially perpendicular to an axis of revolution of the central base ring (Cbr), the first structure (Sbi) comprising a first series of blades (Bi), each blade (Bi) of the first structure (Sbi) extending radially over the angular extent of the blade-like casing with an angle of inclination relative to the plane in which the first structure (Sbi) extends,and the first structure (Sbi) is subject to the central base ring (Cbr)., 2. A brake disc protector device according to claim 1, wherein the blade-type casing comprises U-shaped profile arcs overhanging the central base ring (Cbr) and in each arc a first branch of the two parallel U branches is part of the first structure (Sbi), and preferably a blade (Bi) is part of the first series of blades.

3. A brake disc protector device according to claim 2, wherein each U-shaped profile arc of the blade-type casing also comprises: - a second branch of U (Be) which is a blade (Be) forming part of a second series of blades (Be) of a second structure (Sbe) extending in a plane parallel to the plane in which the first structure extends, each blade (Be) of the second structure (Sbe) extending radially with an angle of inclination relative to the plane in which the second structure (Sbe) extends, - a base (Bp) of the U-shaped profile continuously connecting the first branch (Sbi) to the second branch (Sbe) is a connecting part (Bp) forming part of the peripheral structure (Sp), the peripheral structure (Sp) extends in a plane substantially perpendicular to the planes in which the first (Sbi) and second (Sbe) structures extend.

4. A brake disc protector device according to any one of claims 1 to 3, wherein the blades (Bi, Be) of the blade-type casing are flat and / or helical.

5. A brake disc protector device according to any one of claims 3 and 4, wherein the second series of blades (Be) comprises fewer blades than the first series of blades (Bi).

6. Brake disc protector device according to any one of claims 1 to 5, in which the blades (Bi, Be) of the blade-type casing are inclined relative to the plane in which the structure to which they belong (Sbi, Sbe) extends by an angle of 30 to 60°, and preferably 45°.

7. A brake disc protector device according to any one of claims 1 to 6, wherein the central base ring (Cbr) and / or the blade-type casing are made of metallic material or plastic material or ceramic material.

8. A brake disc protector device according to any one of claims 1 to 7, wherein the blades (Bi, Be) forming part of a series of blades are regularly spaced angularly, and preferably the spacing between two blades forming part of a series of blades is in the range of 2 to 23 degrees in angle.

9. A brake disc protector device according to any one of claims 1 to 8, wherein the blades (Bi) of the first series of blades are regularly spaced angularly, and preferably the maximum spacing between two blades forming part of the first series of blades is approximately 2.8 degrees in angle.

10. A brake disc protector device according to any one of claims 1 to 9, wherein the blade length of at least some of the blades (Bi, Be) of the blade-type casing is greater than or equal to a brake disc track width (Ti, Te). 1 1. Brake disc protector device according to any one of claims 1 to 10, wherein the blade-type casing leaves a gap of at least 1 millimeter, preferably at most 3 millimeters, with a brake disc track surface (Ti, Te).

12. A brake disc protector device according to any one of claims 3 to 11, wherein the second structure covers an angular extent less than the angular extent of the blade-type casing, partially overlapping the first structure (Sbi) of the blade-type casing, preferably its upper extent section, and preferably the angular extent of the second structure (Sbe) is at most 180 degrees.

13. A method of manufacturing a brake disc protector device according to any one of the preceding claims, characterized in that it comprises, in combination, the following steps a) - forming a central base ring and a blade-type casing, preferably by stamping a metal plate or by means of a plastic injection molding process, or by means of a ceramic casting process, and b) - assembling the central base ring to the first structure (Sbi) of the blade-type casing, preferably by welding or brazing.

14. Disc brake assembly comprising a wheel assembly axle spindle (K), a caliper (C), a brake disc (D) and a brake disc protector device according to any one of claims 1 to 12.

15. A motor vehicle comprising at least one disc brake assembly according to claim 14, the vehicle structural element being the axle spindle of a wheel assembly.

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