DE102020100516B4 - Internally ventilated brake disc - Google Patents

Abstract

Internally ventilated brake disc, in particular for commercial vehicles, with two spaced friction rings (1) which are connected to one another by webs (2) delimiting cooling ducts (3) and arranged on several concentric circles (4) to (7), with each circle (4) to (7) associated webs (2) are arranged at the same distance from one another and the distances between the webs (2) and their number on the circle (4, 5, 6) with a smaller diameter are smaller than the distances and the number of webs (2 ) on the circle (5, 6, 7) with a larger diameter, characterized in that the number of webs (2) associated with the respective circles (4 to 7) increases, starting from the inner, i.e. smallest diameter, towards the outside, so that the fewest webs (2) are arranged on the inner circle (4) and the most webs (2) on the outer circle (7).

Description

The invention relates to an internally ventilated brake disc according to the preamble of claim 1.

Brake discs of this type are used in particular in the brake systems of commercial vehicles, and when they are functional, i.e. when braking, they correspond to brake pads which are pressed with their friction sides against the brake disc on both sides.

Generic brake discs are in the DE 10 2014 114 934 A1 as well as the JP H11-336 804 A themed.

In order to reduce the thermal load on the brake disk due to the frictional heat generated during braking, the known brake disks have cooling channels in the intermediate space formed between two friction rings, via which heat is emitted in the form of convection and thermal radiation.

To connect the two friction rings, which are positioned parallel and spaced apart from one another, webs are provided between which the cooling channels are formed.

According to the genus, these webs, which are preferably bolt-shaped, with a round or non-round cross-section, are arranged on several concentric circles. Such a brake disc is also in the DE 102 41 655 A1 disclosed, wherein the number of all the lands associated with the respective circles is the same.

However, it has been shown that so-called hotspots form with such a design, i.e. hot spots on the friction rings that are distributed evenly over the circumference.

These hotspots result in more heat cracks forming, which significantly reduce the service life of the brake disc.

Furthermore, due to the effect of heat, a change in the surface of the outside of the friction rings can be observed, which is referred to as "hot juddering".

Although attempts have already been made to achieve homogeneous pressure distribution by selecting a suitable friction material for the brake pads, these above-described harmonic hotspots, which lead to local overheating of the friction surface, always occur.

This results in metallic transformations and, as a result, embrittlement of the surface of the friction rings, which in turn contributes to the formation of cracks mentioned. This cracking reduces the service life of the brake disc considerably.

Further attempts to minimize or completely eliminate the formation of hotspots, in particular by changing the configuration of the webs or cooling channels or by blade ribs that connect the friction rings to one another, were not effective. Examples in this regard are the WO 2012/164 465 A1 , the WO 2015/092671 A1 or the DE 40 40 423 A1 called.

The invention is therefore based on the object of further developing a brake disc of the generic type in such a way that its service life is improved.

This problem is solved by a brake disk with the features of claim 1 or 3 .

The invention creates an arrangement pattern of the webs in such a way that only one radially aligned row of webs results. In other words, starting from the outer to the inner diameter of the friction rings, the alignment of the individual rows differs from one another, resulting in an uneven arrangement on the surface. The number of ridges assigned to the respective circles increases outwards, starting from the inner, i.e. smallest, diameter, preferably by one ridge each, so that the fewest ridges are arranged on the inner circle and the most ridges on the outer circle.

This results in a pattern in which, starting from the aforementioned radially aligned single-row arrangement of the webs, the webs of the following rows are arranged increasingly offset from one another.

As has surprisingly been shown, the resistance to buckling varies continuously in the circumferential direction due to the changed arrangement of the webs. This variation disturbs the harmonic formation of ripples, reducing the number of so-called hot spots, with the result that surface damage from overheating is minimized.

By avoiding ripples on the friction ring surfaces, not only is braking comfort improved, since a juddering described in the prior art no longer occurs during a braking operation, but also due to the significant reduction in The service life of the brake disc is also noticeably increased due to the formation of heat cracks.

Since a large number of brakes and thus brake discs are installed in a commercial vehicle, this result of the invention is of particular importance, in particular with regard to the cost minimization that is always sought. This results from the reduced downtimes of the vehicle as well as from the procurement and installation of the brake discs.

In addition, the new brake disc can be produced at no additional cost compared to one based on the prior art, with such brake discs usually being made of cast iron.

According to a further idea of the invention, the cross-sectional dimensions of the webs arranged on the smaller circle are smaller than those of the webs of the adjacent larger circle.

According to the invention, the ridges are arranged in a plurality of concentric circles, preferably in four circles. However, a smaller or larger number of circles is also conceivable, with the bars of a circle being arranged at equal distances from one another.

Further advantageous developments of the invention are characterized in the dependent claims.

An embodiment of the invention is described below with reference to the accompanying drawings

The only figure shows a section through a brake disk according to the invention in a plan view.

The figure shows a brake disc, in particular for a commercial vehicle, which has two friction rings 1 arranged parallel and at a distance from one another, with only one friction ring 1 being visible in the figure through the sectional view.

The two friction rings 1 are connected to one another by webs 2 and have a circular cross section in the example.

The webs 2 are arranged on concentric circles 4 to 7 indicated in the figure, four of these circles being provided in this arrangement.

According to the invention, the ridges 2 associated with each circle 4-7 are equidistant from one another, i.e. the ridges 2 are evenly distributed on each of the circles 4-7.

The distances of the ridges 2 and their number on the circle 4 with a smaller diameter are smaller than the distances and the number of ridges 2 on the adjacent circle 5 with a larger diameter, as are the distances of the ridges 2 of the circle 5 to the adjacent larger circle 6 or this to the outer circle 7.

This results in an arrangement pattern that results in only one row of webs 2 arranged in alignment on a radial line 8 .

On both sides of this radial line 8, the webs 2 of the individual circles 4-7 are increasingly offset from one another, with a corresponding alignment of cooling channels 3, which are delimited by the webs 2 and which are open towards the inner and outer circumferences.

Relative to the radial line 8, the webs 2 are arranged in a mirror-symmetrical manner and differ in their cross-sectional dimension towards the outside. That is, the cross-sectional dimensions of the webs 2 arranged on the inner, smaller circle 4 are smaller than those arranged on the circle 5 and these in turn are smaller than those arranged on the circle 6 and these are smaller than those arranged on the circle 7.

Moreover, the cross sections of the webs 2 can be contoured differently. Round as in the example, but also non-round such as oval, polygonal or the like.

Reference List

1

friction ring

2

web

3

cooling channel

4

circle

5

circle

6

circle

7

circle

8th

radial line

Claims (10)

Internally ventilated brake disc, in particular for utility vehicles, with two spaced friction rings (1) which are connected to one another by webs (2) delimiting cooling ducts (3) and arranged on several concentric circles (4) to (7), with each circle (4) to (7) associated webs (2) are arranged at the same distance from one another and the distances between the webs (2) and their number on the circle (4, 5, 6) with a smaller diameter are smaller than the distances and the number of webs (2 ) on the circle (5, 6, 7) with gr ßerem diameter, characterized in that the number of the respective circles (4 to 7) associated webs (2), starting from the inner, i.e. smallest, diameter increases outwards, so that on the inner circle (4) the fewest and on the outer circle (7) most of the webs (2) are arranged. Internally ventilated brake disc claim 1 , characterized in that the number of webs (2) associated with the respective circles (4 to 7) increases by one web (2) in each case, starting from the inner, ie smallest diameter, towards the outside. Internally ventilated brake disc, in particular for utility vehicles, with two spaced friction rings (1) which are connected to one another by webs (2) delimiting cooling ducts (3) and arranged on several concentric circles (4) to (7), with each circle (4) to (7) associated webs (2) are arranged at the same distance from one another and the distances between the webs (2) and their number on the circle (4, 5, 6) with a smaller diameter are smaller than the distances and the number of webs (2 ) on the circle (5, 6, 7) with a larger diameter, characterized in that only one row of webs (2) are arranged in alignment on a radial line (8). Internally ventilated brake disc claim 1 or 3 , characterized in that the number of webs (2) arranged on the smaller circle (4, 5, 6) is 1 less than the number of those arranged on the adjacent larger circle (5, 6, 7). Internally ventilated brake disk according to one of the preceding claims, characterized in that the webs (2) are arranged in up to five circles, preferably four circles (4-7). Internally ventilated brake disc according to one of the preceding claims, characterized in that the cross-sectional dimensions of the webs (2) of the respective circle (4-7) are the same. Internally ventilated brake disc according to one of the preceding claims, characterized in that the cross-sectional dimensions of the webs (2) of each circle (4-7) are different from the webs (2) of the adjacent circle. Internally ventilated brake disc according to one of the preceding claims, characterized in that the cross-sectional dimensions of the webs (2) of the smaller circle (4, 5, 6) are smaller than the cross-sectional dimensions of the adjacent larger circle (5, 6, 7). Internally ventilated brake disc according to one of the preceding claims, characterized in that the webs (2) of adjacent circles are arranged increasingly offset from one another in the circumferential direction, starting from the radial line (8). Internally ventilated brake disk according to one of the preceding claims, characterized in that the webs (2) are arranged mirror-symmetrically in relation to the radial line (8).

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