WO2018059748A1 - Brake disc pot and brake disc having an improved vehicle interface - Google Patents

Abstract

The invention relates to a brake disc (1) comprising a brake disc pot (2) for connecting the brake disc (1) to a wheel hub (4) of a vehicle and at least one friction ring (3) for generating friction together with at least one brake pad of a brake, wherein the brake disc pot (2) has a pot base (5) having an outer side (7) on the wheel side, in relation to a wheel rotation axis (6), and an inner side (8) on the wheel hub side. The brake disc pot (2) is produced by a casting method and the inner side (8) has a non-level profiling (9) in a section viewed through the wheel rotation axis (6).

Description

description

Brake cup and brake disc with improved

Vehicle interface parts

The invention relates to both a cast brake disk hub for connection to a separate friction ring for the purpose of displaying a built brake disc as well as an integrally molded brake disc with molded brake disc hub, each comprising an improved interface to the hub of a motor vehicle, especially a passenger car or a light truck. The invention further relates to a new manufacturing method with downstream cutting for the favorable production of the improved interface with a novel profile in the bottom of the pot.

Brake discs for use in a vehicle brake are known and widely used. In a brake disk, a brake disk pot serves both as a carrier for a friction ring and an interface to a wheel hub. There are brake disc pots with a newly executed inside of the pot bottom known and common, which sits in the ready state in the vehicle over its entire surface on a front side of the wheel hub.

A brake disk essentially serves to convert the kinetic energy of the vehicle into heat, so that the

Brake disc chamber in braking operation considerable thermal and mechanical stresses, in particular torsional shear stresses is exposed and therefore must be carried out particularly stable. Therefore, it is common to brake disc pots of cast

Brake discs due to specific properties of cast materials such as a low because of graphite formation Gefiegenomogenität, a comparatively low Tensile strength or risk of distortion, particularly solid and thick-walled form. This leads to weight increase and deterioration of driving characteristics. In order to reduce the weight, it is known, the brake disc in several parts with a forming technology made of a comparatively thin-walled steel sheet, in particular

thermoformed to carry brake disc pot, which is kraftform- or cohesively connected to a cast friction ring. In addition to an advantageous weight saving such discs have disadvantages such as a complex manufacturing process and additional assembly processes. Of

Further it is due to different

 Material properties in the material mix such as different coefficients of thermal expansion, a very high technical effort is required to permanently ensure a stable connection and an acceptable concentricity.

It is an object of the present invention, while avoiding the aforementioned disadvantages, a low and stable representable and at the same time light brake disc, or

Brake disc pot to submit, which improved by

Interfaces to the hub also simplified maintenance as well as permanently improved concentricity in original equipment and after replacement allows.

The object is achieved according to the invention together with features of independent claim 1. Thus, the invention provides that at least the brake disk hub is produced by a casting process and the cross section of the inside is provided with a non-planar profiling. According to a preferred embodiment, the

Profiling at least one and more preferably two radially mutually spaced planar contact surfaces for axial contact with the wheel hub with a arranged in the radial direction between the contact surfaces axially towards the wheel hub

pre-stretched projection.

As a result, the rigidity of the bottom of the pot and its resistance to torsional loads is significantly increased, thereby reducing the wall thickness on a weight-reducing

Pot bottom allows. Furthermore, the contact surfaces and the projection can be circularly rotationally symmetrical to the wheel rotation axis of the inside of the pot bottom.

 As a result, an improved concentricity in the mating with the wheel hub is achieved and also a brake disk change is significantly simplified. Because the supports between the bottom of the pot and the wheel hub have a reduced contact surface. As a result, a corrosion attack is reduced to the annular

Contact surfaces. The invention further provides that brake disk pot has a substantially tubular cylindrical pot wall and a smallest wall thickness in the pot bottom in the portion of the contact surface formed smaller than a smallest wall thickness in the pot wall and preferably in a size range 2, 5 _o, 5 / + i mm provided As a result, the cost-effective cast brake disc according to the invention can be used without difficulty in exchange for expensive brake discs with a deep-drawn steel brake cup, without any undesired track spreading or and a distortion-prone as well as Rounding-risk interface or connection between components made of two different materials is eliminated. According to a preferred embodiment of the invention, the projection is positioned and its radial extension is made larger than the width of the through-hole, so that the through-holes are located completely within the projection. By such positioning of the

 Through holes in the wall reinforced area, the negative effects on torsional rigidity of the pot bottom in the bolt circle area are reduced or eliminated. Preferably, the brake disc according to the invention is produced in one piece with a casting process, whereby this is particularly homogeneous and inexpensive to produce and eliminates the interface between the brake disc hub and the friction ring with advantages for the weight and the concentricity.

The invention further includes an improved

Manufacturing process, according to which the brake disk hub or the brake disk is produced by casting in the form of an initial forming process and then subjected to a cast finish and in a downstream process step

 Process step, the wall thickness of the pot bottom in the area of the contact surfaces by a machining of the

Inside is reduced. Consequently, with high precision, a lightweight brake disc with greatly improved

Concentricity is achieved whereby a simplified machining with rotary milling process is made possible in a single workpiece clamping.

In a surprisingly simple construction, the profiling according to the invention is rotationally symmetrical with respect to

 Rotary axis of the brake disc defines what a simplified machining with rotary milling in a single

Workpiece clamping allowed. Consequently, at high Precision a lightweight brake disc with greatly improved concentricity.

The drawing documents a preferred embodiment of a ventilated brake disc according to the present invention respectively in different views and in section on a different scale, partially reduced in size

or partially enlarged and simplified. In the drawing shows:

Fig.l Radseitige or front view of a

According to the invention cast in one piece and braced brake disc in plan view (a) and isometric (b).

Fig.2 hub side or rear view of

Embodiment according to Fig.l in plan view (a) and isometric (b) Fig.3 brake disc according to the invention in sectional view V-V

Section along the line V-V according to Fig.l with partly and simplified illustrated wheel hub and wheel with enlarged sections of two different inventive

Embodiments (A, B) of the profiling of the pot bottom.

4 shows the embodiment as in Fig.l in plan view with partially broken friction ring

5 partial section of the hub-side pot bottom

or the inside of the brake disk hub in a spatial representation.

Fig.1 An inventive embodiment of the brake disc 1 is substantially rotationally symmetrical with respect to the

Raddrehachse 6 is formed and has a cup-shaped

Brake disk cup 2 and a connected thereto and radially outwardly from this trimmed friction ring 3. In the illustrated embodiment, the brake disc 1 is in one piece, made of a cast. A built, multi-part design of the brake disc 1 with each other via an interface brake disc hub 2 and friction ring 3 is also allowed within the invention, however, the

 Bremsscheibentopf 2 particularly preferably urformend particular casting technology and not produced by forming process.

The brake disk cup 2 a pot bottom 5 with an outside 7 for conditioning a wheel, not shown. In the bottom of the pot 5 more arranged on a common pitch circle 14 arranged in a regular pitch to each other arranged

Through holes 13 are provided, which are aligned axially parallel to the Raddrehachse 6., The through holes are used to push through screws or bolts, not shown, when mounting the wheel to a hub. Of the

 Brake disk cup 2 further comprises a substantially cylindrical cup wall 12 directed from the bottom of the pot 5 approximately axially and largely parallel to the axis of rotation (6) with a non-rotatable connection to the friction ring 3. In particular because of

technologically required draft angles, the pot wall 12 may also be formed slightly conical.

The friction ring 3 may be hollow within the invention, or as shown hollow, so ventilated, also be formed. In this case, the connection between the pot wall 12 and the friction ring 3 can be present both axially outside as shown, or wheel side or axially inside or wheel hub side. ^

On its visible surface of the outside 7 of the bottom of the pot 5 is formed plan and this either machined just or has in rationalization on a flat Gußhaut.

Fig.2

 The inside 8 of the pot bottom 5 of the invention

Brake disc 1 is not formed evenly but has a separate profiling 9. Radially between two annular contact surfaces 10, 10 which are provided for engagement with the wheel hub and act as a support, an axially inwardly outstretched circumferential projection 11 is formed. In the manufacture of the shown one-piece brake disc 1 according to the invention or the brake disc pot 2 according to the invention, not shown as an assembly component for downstream fixation on the friction ring 3, a blank of a casting material with a thin-walled with respect to the wall thickness of the cup wall 12 pot bottom 5 is first generated. The supports respectively

Contact surfaces 10, 10 ^λ as well as the through holes 13 and possibly further required holes and

Steps / transitions for the profiling 9 are machined according to the pattern described above, time after the cast plaster,

carried out .

Figure 3

 In the sectional view of Figure 3 are in addition to the brake disc 1 in addition to the wheel hub 4 and the wheel 15 partially and simplified to illustrate the component assembly in the assembled state.

The inside 8 of the bottom of the pot 5 is not flat, but designed graduated, which forms a profile 9 in cross-sectional view. The wall thickness of the bottom of the pot 5 is in relation to the largely constant wall thickness (Ww) of the

Pot wall 12 partially reduced and amounts to the sections with the lowest wall thickness Wb in the

Areas of the contact surfaces 10,10 ^λ preferably about 2 to 3.5 mm, more preferably 2.5 mm.

As already described above includes the profiling 9 for forming the reduction of the wall thickness over in the preferred embodiment shown two, radially spaced apart annularly stepped stepped, recesses. As a result, two at a given distance from each other and annular shaped defined support or contact surfaces 10, 11 ^{λ defined} for axial contact with an end face of the vehicle-side hub 4. Between the two

Contact surfaces 10, 11 ^λ is thus a circumferential, inwardly directed projection 11 is formed. The height transitions between this and the contact surfaces 10, 11 ^λ are designed angled so that the projection 11 appears to be trapezoidal in cross-section. Other transitional forms such as wounds, steps, fillets or other helix angles and the like are also permissible within the invention.

The partial circle 14 with through-holes 13 is provided radially in the region of the projection 11, so that the through-holes 13 are arranged completely within a local thickening of the wall thickness of the pot base 5 formed by the projection 11. In comparison with the reduced

Wall thickness (Wb) in the region of the two contact surfaces 10, 10 ^λ , the wall thickness in the region of the projection is preferably about twice, in particular about 5 mm. Because the thickening is provided according to the claim, according to the invention there is not necessarily a strict doubling in a thickness ratio of 1: 2 (50% / 100%). Rather, in particular By varying the quality of the cast material, gradual variations of the thickness ratio ranging between about 1:10 (10% / 100%) to about 9:10 (90% / 100%) are conceivable without departing from the basic essence of the invention.

In principle, gray iron is in particular GG 15 for forming the brake disc 1 and

Brake disc pot 2 used.

The wheel hub 4 has a circumferential flange 17 arranged therein, with the through holes 13 corresponding mounting holes for fixing the not shown

Wheel fasteners such as bolts or screws. to

Housing the projection 11, a circumferential recess 16 is provided in the end face of the wheel hub 4.

It has been proven that the material GG 15, GG 20 is particularly suitable for the design of the brake disk pot. In a further improvement of the strength properties as well as the thermal - tribological properties can also

highly carbonated - ie HC gray cast iron - or alloyed gray cast iron grades are used.

 In particular, when using GG 20 HC, it is possible in a particularly thin-walled dimension of the

Thickness ratio of, for example, to reach about 1:10, whereby the brake disc 1 can be made very light and yet stable.

In the enlarged partial section A, the embodiment described above is illustrated while the partial section B is another embodiment of the invention or

 Variant shows. Here, in the region of the projection 11 in the outer side 7 of the pot bottom 5, a circumferential groove-like

Recess 19 introduced. In such a recess punching marks can be introduced, for example, without the thus thrown up material must be ground to the required for the installation of the wheel 15 flatness of the

To ensure outside 7. Figure 4

 The preferred embodiment of the invention

Brake disc 1 is formed with an internally ventilated friction ring 3, the interior of which has a plurality, preferably three concentric rows of connecting webs, between which air ducts for removing the heat in braking operation are formed.

Figure 5

 In FIG. 5, the invention is based on a spatial representation of a partial section of the pot bottom 5

Profiling 9 of the inside 8 illustrates.

Reference sign

1 brake disc

 2 brake disc pot

 3 friction ring

 4 wheel hub

 5 pot bottom

 6 wheel rotation axis

 7 outside

 8 inside

 9 profiling

 10 contact area

 11 lead

 12 pot wall

 13 through holes

 14 pitch circle

 15 wheel

 16 recess

 17 flange

 18 mounting opening

 19 recess

 Wb Smallest wall thickness of the pot bottom

Ww wall thickness of the pot wall

Claims

claims 1. Brake disc (1) comprise a brake disc hub (2) for connecting the brake disc (1) to a wheel hub (4) of a vehicle and at least one friction ring (3) for generating friction with at least one brake pad of a brake, wherein the brake disc hub (2 ) has a pot bottom (5) with respect to a Raddrehachse (6) wheel-side outside (7) and a wheel hub side inside (8), characterized in that at least the brake disk chamber (2) is produced by a casting process and the inner side (8) is provided with a non-planar profiling (9) as seen in a cross section through the wheel rotation axis (6). 2. Brake disc (1) according to claim 1, characterized in that the profiling (9) at least one level Contact surface (10) for axial abutment with the wheel hub (4) and at least one, relative to the contact surface (10) axially in the direction of the wheel hub (2) pre-stretched projection (11). 3. Brake disc (1) according to claim 2, characterized in that the profiling (9) at least two radially spaced planar contact surfaces (10,10 ^λ ) for axial contact with the wheel hub (4) and the projection (11) in the radial direction between the contact surfaces (10, 10 ^λ ) is arranged. 4. Brake disc (1) according to claim 1 or 2 characterized characterized in that the contact surface (10) or Contact surfaces (10, 10 ^λ ) and the projection (11) are circularly rotationally symmetrical to the Raddrehachse (6) of the inside (8) of the pot bottom (5) are formed. 5. Brake disc (1) according to claim 1, characterized in that the brake disc hub (2) has a substantially tubular has cylindrical pot wall (12) and a smallest wall thickness (Wb) in the bottom of the pot (5) is less than a smallest wall thickness (Ww) in the pot wall (12) is trained. 6. Brake disc (1) according to claim 5, characterized in that the smallest wall thickness (Wb) in the pot bottom (5) in the portion of the contact surface (10) and preferably in a size range 2.5 -0.5 / + l mm is provided. 7. Brake disc (1) according to claim 2, characterized in that in the bottom of the pot (5) several arranged in regular pitch offset each other, and parallel to Raddrehachse (6) axially aligned through holes (13) are positioned on a common pitch circle (14) and the Partial circle (14) is arranged radially within the projection (11). 8. Brake disc (1) according to claim 7, characterized in that the radial extension of the projection (11) is greater than Width of the through hole (13) is formed so that the through holes (13) are completely within the Projection (11) are located. 9. Brake disc (1) according to one of the preceding claims, characterized in that the brake disc (1) is produced in one piece with a casting process. 10. A manufacturing method for a brake disk chamber (2) or a brake disk (1) according to one of the preceding claims, characterized in that in an upstream Process step of the brake disk chamber (2) or the Brake disc (1) produced by casting as a blank and then subjected to a Gußputz and in a downstream process step the wall thickness of the Pot bottom (5) in the region of the contact surface (10) or Contact surfaces (10, 10 ^λ ), the wall thickness (Wb) is reduced by a machining of the inside (8).