HK1195931B - Disc brake for a motor vehicle and brake lining - Google Patents

Description

Disk brake and brake lining for a motor vehicle

Technical Field

The invention relates to a disk brake for a motor vehicle and to a brake lining.

Background

A conventional disc brake essentially comprises a brake disc which rotates with the axle during operation, at least one or more brake linings arranged on one side of the brake disc or preferably on both sides of the brake disc, a brake caliper and a brake carrier which extends preferably on one side or both sides of the brake disc. The disc brake with the brake bracket preferably has a sliding caliper or a pivoting caliper that is movable relative to the brake.

In order to ensure reliable functioning of the disc brake, it is necessary to reliably guide and support the brake pads in the brake caliper or brake carrier.

For this purpose, the brake carrier known in general (and also the brake carrier according to the invention) preferably has two carrier angles arranged one behind the other in the circumferential direction of the brake disk on each side of the brake disk, which carrier angles are connected to one another by at least one support element and project radially beyond the frame, which carrier angles laterally delimit the lining grooves for receiving the brake linings. In this case, according to the prior art, the lining groove is also preferably configured to open in the outward direction, so that the brake lining can be moved radially from the outside into the lining groove. After installation, the brake lining is radially fixed by the pressure bracket. Alternatively, a lining retention spring, in particular a lining retention spring which is arranged elastically and acts between the lining hold-down bracket and the brake lining, can be provided.

Brake linings are subjected to a variety of loads during operation. The brake linings are subjected to high thermal and mechanical loads. Different load states are generated in the two operating states of a) the operating brake and b) the non-operating brake.

When the brake is actuated, the brake linings are subjected to high pressures and transverse forces, wherein the brake linings enable the transverse forces generated at the friction surfaces of the brake linings to be introduced via the friction material into the lining carrier plate and from there into the brake caliper or the brake carrier. The transverse forces acting on the brake lining are thereby predominantly received by the bearing angle on the outlet side, i.e. in the direction of rotation of the brake disk in front.

Furthermore, the brake linings must convert the contact pressure generated by the brake caliper into a pressure which is distributed as uniformly as possible over the friction surfaces. For this purpose, the contact pressure generated by the brake caliper must be converted into a surface load by means of a flexurally rigid lining carrier plate.

The problem is that, due to the limited installation space conditions, the elongated flanks or support surfaces of the lining carrier plates of the known brake linings, which bear against the end faces of the brake carrier, cannot prevent a rotational movement of the brake lining during braking. This rotational movement can have a negative influence on the air gap, i.e. the clearance between the friction lining and the brake disk, and on the wear behavior of the brake lining, in particular in the form of a deflection wear, and also on the clearance of the lining.

DE 2926818 a1 is regarded as prior art.

Disclosure of Invention

The object of the invention is to further develop a disk brake of this type in such a way that the aforementioned adverse effects on the operating performance are avoided as far as possible.

This object is achieved by a motor vehicle disc brake. The disk brake has a brake caliper overlapping the brake disk, a brake carrier which can be fixed in a positionally fixed manner to the vehicle and in which at least one brake pad which is equipped with a pad carrier plate and a friction pad fixed on the pad carrier plate is guided, wherein the brake carrier has a bearing angle of the pad carrier plate supporting the brake pad on an inlet side and an outlet side in the main direction of rotation of the brake disk, wherein the bearing angle of the inlet side of the brake carrier and a bearing surface of the pad carrier plate adjacent to the bearing angle engage with one another, characterized in that the bearing angle of the outlet side and a corresponding bearing contour of the pad carrier plate have a bearing surface which is inclined at an inclination angle to the Y axis in its entirety, in regions or at least in the region of the radial highest point of the pad support on the brake carrier.

Here, the bearing angle in the rear direction in the main rotation direction of the brake disk, i.e., the rotation direction of the brake disk during forward travel of the vehicle is referred to as the inlet-side bearing angle.

Accordingly, the bearing angle at the front in the main rotation direction of the brake disc, i.e. the rotation direction of the brake disc, during forward travel of the vehicle is referred to as the bearing angle at the exit side.

The outlet-side bearing angle and the contour of the corresponding lining carrier plate have bearing surfaces which are each inclined relative to the Y axis at an inclination angle α >0 ° at least in the region of the radially highest bearing point, wherein the bearing surfaces are designed to bear against one another in the main movement direction during braking.

In order to prevent a tangential slip-off of the brake lining as a result of the inclined position of the highest support point a, the inclination angle is preferably smaller than the coefficient of friction μ at the support point between the force introduction angle and the bearing angle on the outlet side_aAn inclination α between 8 ° and 30 ° is particularly advantageous, also in order to ensure that the lining does not slip off tangentially at the bearing angle support, it is preferably provided that the angle α has a value between a minimum of 8 ° and a maximum of 30 °.

In the disc brake according to the invention, in which the entry-side bearing corner of the brake carrier of the disc brake and the support face of the lining carrier adjacent to the bearing corner engage with one another, the brake lining is supported at a support point on the exit-side bearing corner, which support point lies below a force action line representing the total friction force in the Y direction.

This force distribution which can be achieved at both bearing angles has a favourable effect on the braking performance.

On the one hand, a defined torque about a Z axis parallel to the axis of rotation of the brake disk results on the brake lining. The support force is also advantageously generated by this torque on the entry side at the support angle and therefore this side of the brake carrier is added to the force flow during braking, as a result of which a more effective force distribution or force transmission in the brake carrier is again achieved. In conventional brake carriers, there is no inlet-side support of the brake lining, but rather a very large proportion of the lining support at the bearing angle on the outlet side.

It is therefore advantageous that a more uniform force distribution is present over both bearing angles during braking compared to the prior art, which relatively low highest support point (in the Y direction) also contributes significantly to the force distribution.

This is illustrated on the basis of a first model study. Briefly, for the purposes of describing the lining, a model can be assumed of a short annular segment in the circumferential direction (i.e. the angle of coverage in the circumferential direction)Considered relatively small for simplicity), for which there is a force action line or force action vector which passes through the center of gravity of the brake lining in the X direction (perpendicular to the rotor axis of rotation). In fig. 2 and in the further figures, the force action vector is located in the variant shown in the figures exactly or approximately radially in the center of the brake lining and in the circumferential direction in the center of the brake lining or approximately in the center of the brake lining. On the contrary, for this purpose, see fig. 3 and 4 and also further figures in addition to fig. 1, the support of the outlet side of the brake carrier is preferably and advantageously further carried out to the inside in the Y direction perpendicular to the axial direction of the brake disk, with respect to the force action vector set at the center of gravity. This also applies to those figures in which the brake carrier is not drawn.

The highest support point a of the brake lining in the direction Y at the bearing angle of the outlet side particularly preferably has a spacing h from the force action line which is at least 0.1 times the length of the brake lining in the direction of the force action line of the total friction force and/or between 0.1 and 0.25 times the width of the brake lining perpendicular to the force action line of the total friction force. In this way, the introduction and distribution of the forces on the inlet side is also advantageous, as will be explained in more detail further below.

Furthermore, it is particularly advantageous if the outlet-side bearing angle and the corresponding contour of the lining carrier plate each have a bearing surface which is inclined by a certain inclination angle α >0 ° relative to the Y axis, wherein the bearing surfaces are defined in the main travel direction for bearing against one another during braking.

In order to prevent the brake lining from sliding tangentially due to the inclined position of the highest support point a, the inclination angle is preferably smaller than the coefficient of friction μ at the support point at the force introduction angle and at the bearing angle on the outlet side_aAn inclination angle α of between 8 ° and 30 ° has proved particularly advantageous, also in order to ensure that the lining does not slide off tangentially at the support of the support angle, an angle α of a value of between a minimum of 8 ° and a maximum of 30 ° is preferably obtained.

The above-detailed considerations apply to the braking process in the forward direction. However, in order to be able to brake in the reverse direction without functional impairment, the brake bearing angle pointing in the forward direction toward the inlet side must have a minimum height. The rule that the height of the brake application angle should be greater than the height position of the line of action of the lining friction forces oriented in the circumferential direction is advantageous here. This ensures that no additional back-out torque is generated on the brake lining by the support of the brake lining.

According to an advantageous embodiment, the exit-side support angle of the brake carrier is configured to be lower than the entry-side support angle. This relates in particular to the radial distance from the axis of rotation (Z axis) of the brake disk. The inlet-side support angle, which is formed in a radially raised manner relative to the outlet-side support angle, ensures in particular a secure and secure fixing and prevents the brake lining from being unscrewed from the brake carrier on the inlet side.

In particular, the entry-side bearing angle is higher than the intersection of the line of force action and the entry-side bearing angle, which also improves the holding capacity of the brake lining during backward travel.

According to a further embodiment, the bearing angle of the outlet side of the brake carrier and the support surface of the lining carrier plate adjacent thereto are shaped in such a way that the lining carrier plate can be pivoted radially away from the axis of rotation of the brake disk in the brake carrier on the outlet side. This makes it possible to provide a structural design of the brake carrier and of the lining carrier plate for preventing a rotational movement of the brake lining, while at the same time a simple installation and removal of the brake lining is possible. The brake lining can be inserted into and removed from the brake carrier in a simple manner by a pivoting movement.

According to an advantageous embodiment, the support surface of the lining carrier plate adjacent to the entry-side carrier corner of the brake carrier has an offset which engages in an undercut on the entry-side carrier corner corresponding to the offset. In this way, the friction lining is not only prevented from unscrewing on the inlet side by the sufficient frictional forces present but also by the shaping of the lining carrier plate and the carrier on the inlet side, as a result of which a redistribution of the relatively high supporting forces on the inlet side is also achieved. In this case, it is particularly advantageous if the offset engages in an undercut on the entry-side support corner, for example, in a form-fitting manner, in that the entry-side support corner has a head part which overlaps the offset of the support surface of the lining carrier plate adjacent to the entry-side support corner.

According to a further preferred embodiment, the lining carrier plate is shaped by forming the respective offset asymmetrically with respect to a mirror axis which runs centrally through the brake lining and through the axis of rotation of the brake disk. Various advantages are thereby also obtained. The rotation effect of the brake lining is thus prevented during the braking process by the inlet-side introduction of the brake lining in a manner acting in the radial direction. Furthermore, the asymmetry creates the possibility of asymmetrically arranging the friction material of the brake lining, for example for compensating for the skewed wear of the friction material. Furthermore, the asymmetrical design eliminates the possibility of incorrect installation of the brake lining into the brake carrier to some extent. The undercut thus preferably extends as a projection in the direction of the main direction of rotation of the brake disk and is engaged by the lining carrier plate on the inlet side below, so that the brake lining cannot be removed from the brake carrier directly radially with respect to the brake disk center.

Drawings

Embodiments of the present invention are described in detail below with reference to the accompanying drawings.

The figures show:

figure 1 shows a side plan view of a brake lining held in a brake carrier according to the prior art,

figure 2 shows a side view of a first design variant of a brake carrier according to the invention with a brake lining inserted into the brake carrier,

figure 3 shows a side view of the brake bracket and brake pad of figure 2 with the brake pad pivoted for installation and removal,

fig. 4a to 4d show side views of the brake lining and the brake carrier in fig. 2, wherein the brake disc and the forces acting on different points on the brake carrier or brake lining are shown,

fig. 5 shows a top view of the brake lining and brake carrier of fig. 2, wherein the forces acting at different points are shown,

figures 6a to 6e show different design variants of the shaping of the brake lining according to the invention,

figure 7 shows a perspective view of a second design variant of the disc brake according to the invention,

figure 8 shows a perspective view of a brake carrier of a design variant of the disc brake in figure 7,

figure 9 shows a perspective view of a brake lining of a design variant of the disc brake in figure 7,

FIGS. 10a to 10c show different design variants of the shaping of the friction lining of the brake lining according to the invention, and

fig. 11 and 12 show a side view of a design variant of the brake carrier according to the invention with a brake lining inserted into the brake carrier.

Detailed Description

In the following description of the figures, terms such as upper, lower, left, right, front, rear, etc. relate essentially to the exemplary views selected in the respective figures and the position of the disc brake, the lining carrier plate and the brake carrier in the figures. In the other installation position, the coordinate system used for the description is also jointly moved.

In a cartesian coordinate system, the Z axis runs parallel to the brake disk rotation axis (at C, see fig. 4a and 5), the X axis runs perpendicular to the brake disk rotation axis (at C, see fig. 4a) through the brake disk rotation axis or parallel to the straight line, and the Y axis runs perpendicular to the X axis and the Z axis. The Y axis also preferably extends through the center of gravity of the brake pad approximately in the center of the pad slot (in the circumferential direction).

Fig. 2 shows a schematic illustration of a detail of the disk brake. The lining carrier of the brake lining 4 is denoted by reference numeral 42, to the rear side of which, not visible in fig. 2, a friction lining 41 (which can be identified in fig. 5, 7 or 10) is fixed. The lining carrier 42 of the brake lining 4 is mounted on the vehicle-side brake carrier 1 in a stationary manner and is held in the brake carrier 1 on the brake caliper side by means of the lining holding carrier 6.

In this case, the brake carrier 1 can be designed as a separate component, as shown here, or as an integral component of the brake caliper 8. In order to fix the brake carrier 1 on the axle, the brake carrier is usually provided with a hole 7 into which a screw or bolt can be inserted and which holds the brake carrier on the axle. Other support elements for holding and/or supporting the brake lining 4 can also be considered.

As shown in fig. 4a, b and 7, the brake carrier 1 overlaps or tensions a radially outer section of the brake disk 5 in a frame-like manner and is essentially composed of two carrier angles 2, 3 which are connected to one another by a bridge 11 and which are arranged one behind the other in a plane parallel to the braking surface of the brake disk 5 and which support the lining carrier plates 42 of the brake lining 4 laterally, i.e. on the inlet side and the outlet side.

The brake carrier 1 shown in fig. 7 tensions the brake disk on the active side and on the reaction side. Design variants of brake carriers holding the brake lining only on the active side or only on the reaction side can also be considered. The brake linings 4 arranged on the other side of the brake disk 5 are preferably held directly in the brake caliper 8 in this alternative embodiment. The brake caliper 8 is preferably a brake caliper movably arranged on the brake carrier.

In this case, the lining carrier plate 42 of the brake lining 4 is inserted in the installed state without or almost without play into the radially outwardly open lining groove of the brake carrier 1 formed by the carrier angles 2, 3 and the web 11 connecting them.

In contrast to the disk brake according to the prior art as shown in the example in fig. 1, the entry-side support angle 3 of the brake carrier 1 is not designed here as a carrier 102 with a straight support surface 104 facing the brake lining, but rather has an undercut 32 which receives an offset 424 at a support surface 422 of the lining carrier plate 42 adjacent to the entry-side support angle 3 of the brake carrier 1.

The undercut 32 and the offset 424 on the support surface 422 of the lining carrier plate 42 adjacent to the entry-side carrying corner 3 of the brake carrier 1 are shaped in such a way that the brake lining 4 can be pivoted about a pivot axis parallel to the axis of rotation C of the brake disk 5 (shown in fig. 4a) counter to the main direction of rotation HDR of the brake disk 5. The undercut 32 extends as a projection in the direction of the main direction of rotation HDR of the brake disk 5 and is engaged by the lining carrier plate 42 on the inlet side, in particular the aforementioned offset 424, from below, i.e. the brake lining 4 cannot be removed from the brake carrier 1 directly radially with respect to the brake disk center C.

The bearing corner 2 on the outlet side of the brake carrier 1 and the support surface 41 of the lining carrier plate 42 adjacent thereto are correspondingly shaped in such a way that the brake lining 4 can be pivoted about a pivot axis parallel to the axis of rotation C of the brake disk 5 counter to the main direction of rotation HDR of the brake disk 5. The brake lining 4 is thus held in the brake carrier 1 such that a pivoting movement or a combination of a pivoting movement and a radial movement is required for installation and removal, wherein the radial movement is carried out after pivoting out of the brake lining 4 from the undercut 32 and removal of the brake lining 4 or before pivoting the brake lining 4 into the undercut 32 of the entry-side support angle 3. This ensures that the brake lining 4 is easily inserted into the brake carrier 1 or removed therefrom.

As can be seen from fig. 2, the support surface 41 of the lining carrier plate 42 adjacent to the carrier corner 2 on the outlet side of the brake carrier 1 has an offset 43 which at least partially overlaps the carrier corner 2. The design and arrangement of the offset 43, 44 of the lining carrier plate 42 on which the friction lining 41 is arranged and the undercut 32 of the brake carrier 1 in this case make it possible for the lining carrier plate 42 and also the brake carrier 1 to have an asymmetrical shape, which is advantageous for the insertion and removal of brake linings and also for improved support of the brake lining or lining carrier plate on the brake carrier 1.

The pivot axis about which the brake lining 4 can pivot is preferably located in the vicinity of the head region 33 of the entry-side carrier corner 3 in the region of the support surface 422 of the lining carrier plate 42 adjacent to the entry-side carrier corner 3 of the brake carrier 1, preferably in the region of 20mm (< ═ 20mm) in the vicinity of the head region 33 of the entry-side carrier corner 3.

In the brake carrier and lining carrier plate according to the prior art, the brake carrier 100 (shown in fig. 1) is designed with carrier angles 101, 102 which support the lining carrier plate 105 on the inlet side and the outlet side, respectively. For inserting or removing the lining carrier plate 105, the lining carrier plate is inserted vertically into the gap between the two carrier corners 101, 102, wherein the carrier corners 101, 102 extend to the radially outer edge or almost to the edge of the lining holding carrier 105. The support surfaces 103, 104 of the carrier plate 105 adjacent to the carrier corners and the inner surfaces 101, 102 of the carrier corners are configured as flat surfaces. In particular, the outlet-side carrier angle 101 must withstand the highly concentrated forces at the upper end, which is accompanied by high loads and deformations of the carrier angle and by an unfavorable force distribution in the lining retention carrier 105 of the brake lining and the brake carrier 100.

In contrast, as shown in fig. 2, 3 and 4a to 4d, the outlet-side support angle 2 is designed to be relatively low or flat, so that the upper support point a of the lining retainer 42 on the outlet-side support angle 2 is not located at the upper end of the support surface 421, but rather is located on a force action line F which describes the total frictional force acting on the brake lining 4_RxgesAs shown in particular in fig. 4b, below. Here, the force action line F_RxgesRadially at the level of the centre of gravity of the brake lining. In this case, the support point is located approximately in the center or below the center of the support surface 421 on the brake lining. As a result, a defined torque about the Z axis acts on the lining retention carrier 42 of the brake lining 4 during braking. This torque produces a supporting force which also acts on the undercut 32 and the offset 424 on the entry-side carrier limb 3 and thus also merges the entry side of the brake carrier 1 into the force flow during the braking process.

The outlet-side bearing angle 2 and the inlet-side bearing angle 3 have bearing surfaces 21, 31 at the base of the respective bearing angle, which are parallel to one another or, as shown in fig. 2, are preferably separated at an acute angle with respect to a line parallel to the y axis in a coordinate system defined further below.

The length of the support surfaces 21, 31 which laterally partially enclose the lining retainer carrier 4 is preferably approximately half the height hB of the lining carrier plate 42 or less, in order to achieve, on the one hand, pivoting of the lining carrier plate 42 into or out of the brake bracket 1 and, on the other hand, to keep the torque acting on the outlet-side carrier angle 2 during the braking process as low as possible.

In accordance with the design of the offset 43 on the support surface 41 of the lining carrier plate 4, the support surface 21 is inclined away from the lining carrier plate 42 above the support surface 21 of the bearing corner 2 on the outlet side to form the inclined surface 22.

In accordance with the configuration of the offset 44 of the entry-side support face 42 of the lining carrier plate 4, the support face of the lining carrier plate 42 is inclined inward above the support face 31 of the entry-side support corner 3, forming an undercut 32.

Fig. 3 shows that the lining with the lining carrier plate 42 is particularly easy to insert into the brake carrier 1 or to remove from the brake carrier. In this case, it can be easily recognized that the lining carrier plate 42 is disengaged from the undercut 32 on the head 33 of the entry-side carrier corner 3 by a simple pivoting movement.

In fig. 4a to 4d, force arrows representing forces acting on different points of the component are shown in addition to the component. The axis of rotation of the brake disk 5, which at the same time defines the Z axis as a cartesian coordinate system, is denoted by the reference symbol C. The horizontal dotted line (X-axis) and the vertical dotted line (Y-axis) orthogonally intersecting at C serve as the X-axis and the Y-axis of the coordinate system.

If the forces on the brake lining 4 are taken into account more precisely in a plane and if, in particular, a short covering angle of the lining is no longer simply assumed, but rather a covering angle in the circumferential directionThe cover angle is substantially larger (and preferably greater than 25 °, particularly preferably greater than 35 °, when viewed from the center of the circle), then it applies (see fig. 4 a):

for the inlet-side lining halves:

a disk rotation axis in the x direction (having a as viewed in a cartesian coordinate system) as the Z axis; b) a Y axis perpendicular to and intersecting the Z axis; and c) an X-axis that perpendicularly intersects the Y-axis, but does not intersect the Z-axis):

wherein

p: surface pressure of brake lining

b: width of lining

r_m: radius of friction

μ: coefficient of friction of lining

Angle of coverage in the inlet or outlet direction

Kappa: angle of coverage in the inlet or outlet direction at the contact point of the bearing angle of the inlet or outlet side

F_Rxe: lining friction force component in x direction on lining inlet side

Radius of friction r_mIs assumed to be located in the center of the brake disc or brake lining in the radial direction.

The lining friction acting in the x direction must be received by the brake carrier angle 2 on the outlet side.

In the y direction:

wherein

F_Rye: liner side facing Friction force liner Friction force component entering in the y-direction

Pad friction acting in the y direction causes the brake pad to be withdrawn from the brake carrier groove.

For the outlet-side lining halves:

in the x direction, the same force action direction allows the relational expression to be called up without changing the inlet-side pad half.

In the y-direction the above relation applies, however with opposite sign. In this case, this force causes the brake lining to be pressed into the brake carrier groove.

Wherein

F_Rya: lining friction force component on the lining side away in the y direction

Due to this fact an asymmetrical force action in the y-direction on the brake lining results.

The total lining friction acting in the x direction is:

wherein:

F_Rxa: lining friction force component on the lining side away in the x direction

F_Rxges: at the x directionUpward total lining friction

This force must be received solely by the carrier angle 2 on the outlet side.

If now the force and moment balances about the Z axis in point a at the contact point a of the bearing angle on the exit side are taken into account (fig. 4b), the following formula results in consideration of the previously determined relationship:

ΣM_(A)＝0＝F_ey·1-F_Rxges·h-F_Rya·1/4 1-F_Rye·3/4 1

ΣF_(x)＝0＝F_ax-F_Rxges

ΣF_(y)＝0＝F_ay-F_Rya-F_Rye-F_ey

by means of F_Rya＝-F_RyeTo obtain:

wherein:

F_ey: supporting force of bearing angle of inlet side in y direction

F_ay: support force of bearing angle of outlet side in y direction

I: lining length of brake lining 4

h: the distance of the line of force action from the support point (A) on the exit-side support angle 2

It is surprisingly apparent from this formula that a supporting force can also be generated on the inlet side by a corresponding shaping of the brake carrier 1.

In order to achieve this, it is advantageously provided that the brake lining 4 in the brake carrier 1 is prevented from backing out on the inlet side. This can be achieved, for example, by a projection on the brake lining 4 engaging into the brake carrier 1 (see fig. 2).

The formula including the ratio h/l is likewise shown: the support force on the entry-side support angle 3 can surprisingly and advantageously be increased by the exit-side radial relatively low radial support point a, which can be easily achieved in particular by setting the exit-side support angle 2 lower than the entry-side support angle. (h should be as large as possible; the support point A is especially the extremely high/highest support point A in the radial direction).

By the measures described, a more favorable force distribution is achieved in the brake carrier 1. Conventional brake carriers without inlet-side support of the brake lining have a highly concentrated lining support force in the inlet-side bearing corner.

In conventional brake carriers, the friction force component on the inlet side of the lining acting in the y direction has to be introduced into the caliper support device primarily via the frictional contact between the lining carrier plate and the brake caliper or pressure element. The friction force component on the inlet side of the lining results in a high load on the caliper support device. To avoid premature wear or failure, relatively robust dimensions are therefore required, which in turn requires a large installation space.

Furthermore, there is the possibility that in the event of too little force fit between the brake lining and the brake caliper or pressure piece (for example in the presence of grease or oil) a unscrewing of the brake lining and thus a brake failure can occur.

As described above, the brake lining 4 should be suspended in the brake carrier angle 1 on the inlet side. In order to ensure simple mounting and dismounting, the mounting and dismounting should therefore be effected by a pivoting movement of the brake lining. To achieve this, the corresponding contours of the outlet-side carrier corner 2 and the lining carrier 42 have inclined support surfaces, as shown in fig. 3 and 6.

However, the inclination angle α of the support angle 2 of the outlet side with respect to the Y axis cannot be arbitrarily selected. In one aspect, the minimum tilt position is determined by the load and unload conditions. On the other hand, the maximum tilt position allowed is preset by observing a self-locking boundary. Beyond the self-locking limit, a tangential sliding away of the brake lining 4 may result. The self-locking limit is decisively dependent on the pad geometry, the friction behavior on the pad support and the direction of the force transmission between the brake pad 4 and the brake carrier 1.

The physical association is shown in fig. 4c and is determined by the following formula.

For the force action angle γ, the following applies:

Y＝arctan F_Ray/F_Rxges

wherein the content of the first and second substances,

wherein F_aN＝F_aR/μ_aAnd

F_aR＝F_aT(conditions of self-locking) gave:

wherein:

γ: angle of force action on the outlet-side support angle 2

α: inclination of the support surface at the bearing angle 2 on the outlet side

F_a: total support force at the bearing angle on the outlet side

F_aN: normal force at bearing angle of outlet side (perpendicular to support surface)

F_aT: tangential force at the bearing angle of the outlet side (parallel to the support surface)

μ_a: coefficient of friction at lining support on bearing angle of outlet side

The above formula defines the inclination of the bearing angle 2 on the mouth side and the friction μ at the bearing point_aAnd a force introduction angle gamma.

In order to ensure that the lining 4 does not slide off tangentially on the support of the bearing angle 2, the angle α selected must be significantly smaller than the angle calculated by means of the above relationship.

Actual friction conditions (mu) taking into account the usual dimensions and bearing angles of brake linings for heavy commercial vehicles_a0.1 to 0.2), an angle α that yields a value between a minimum of 8 ° and a maximum of 30 ° is preferred.

The above-implemented test method is suitable for braking processes in the forward direction. However, in order to be able to carry out the braking process in the reverse direction without functional impairment, the brake carrier angle 3 oriented in the forward direction toward the inlet side has a minimum height. Here, the same applies as is usual in conventional brake carriers. Advantageously, the height of the brake carrier should be greater than the radial height position of the lines of action of the lining friction forces oriented in the circumferential direction. This ensures that no additional back-out torque is generated on the brake lining by the support of the brake lining. The offset v of these two lines of action can be seen in fig. 4 d.

Since reverse braking in road vehicles is usually performed less frequently and with less force, the lining guide for reverse braking can be constructed in a simplified manner compared to forward braking without functional restrictions.

Due to the above-described requirements for forward braking and the requirements for the insertion and removal of the lining and for the lining support in reverse braking, an asymmetrical geometry of the brake lining 4 is obtained as a function of the system.

Typical for asymmetrical lining and brake carrier geometries are relatively low support angles on the brake carrier side oriented toward the outlet side; an inclination posture of the lining support part of the bearing angle on the outlet side, wherein the inclination posture angle is preferably more than or equal to 8 degrees and less than or equal to 30 degrees; the engagement between the brake carrier corner 3 and the brake lining 4 on the inlet side of the brake carrier 1 (for example by means of a projection on the brake lining and a corresponding convergence on the carrier corner 3) and the relatively high support corner 3 on the side of the brake carrier oriented towards the inlet side.

The following variables are also defined in fig. 4 b: f_ey: reaction force on the inlet side, l: length of lining, F_R: friction force of brake lining, h: the distance of the line of force action from the lining support; f_ax: lining support force; f_ay: reaction force on the outlet side.

It is important that, due to the shape of the support angles 2, 3 according to the invention and the support surfaces 41, 41 of the lining carrier plate 42, not only the support angle 2 on the outlet side but also the support angle 3 on the inlet side contribute to the support of the lining carrier plate 42 during braking.

As shown in fig. 5, the following equations apply for the forces and moments on the brake lining about the longitudinal axis (y-axis) during its displacement under the action of the force in the x-direction:

1.ΣF_(z)＝0＝F_Ra-F_z+F_P+F_Re

2.ΣF_(X)＝0＝F_ax-F_R

F_z: pressing force

F_P: pad pressing force on brake disc

F_Ra: friction force at outlet side

F_Re: friction force at inlet side

d: thickness of lining

x: distance between lines of force of the pressing

The asymmetry of the force action on the brake lining or lining carrier plate 42 therefore applies:

for F_Re0 (inlet side friction) and F_RaIf 0 (friction force on the outlet side) and d 0 (lining friction force and support force on the same plane) apply:

f in formula 1_z＝F_P

(ideally, uniform force distribution in the lining)

For a conventional brake lining without friction forces at the inlet-side friction lining support angle, the following applies:

the above-derived relationship applies for the brake lining 4 having a frictional force on the inlet-side brake carrier 3:

thus, the brake carrying angle on the inlet sideThe brake carrier 1 having the frictional force at 3 has a condition of the excess of the brake lining having no frictional force at the inlet side (F)_ReI) More appropriate force distribution.

The offset 423, 424 on the support surfaces 421, 422 of the lining carrier plate 42 and the undercut 32 on the entry-side support corner 3 allow the lining carrier plate 42 to be inserted into the brake carrier 1 without or with little play.

The corresponding shaping of the support angles 2, 3 of the brake carrier 1 shown by way of example in fig. 6a to 6e and the design variants of the lining carrier plate 42 can also be considered.

In fig. 6a, rectangular offset projections with support surfaces 423, 424 running parallel to the X axis are therefore molded on the lining carrier plate on the outlet side and the inlet side, respectively, wherein the inlet-side surface 4241 of the offset 424 bears against the correspondingly oriented undercut 32 of the inlet-side bearing corner 3 and the outlet-side support surface 423 rests on the outlet-side bearing corner 2.

In the design variant shown in fig. 6b, the offset projections 423, 424 are shaped as rounded portions, which bear on correspondingly shaped undercuts of the inlet-side bearing corner 3 and on correspondingly shaped resting faces 22 of the outlet-side bearing corner 2.

In the design variant shown in fig. 6c, the offset 424 is shaped as a semicircular bulge on the inlet side. The entry side 421 of the offset carrier plate 42 is shaped in the form of two straight faces running at an angle to one another for bearing on the bearing corner 2 of the exit side.

The lining carrier plate 4 shown in fig. 6d, 6e and 9 is characterized in that a rectangular offset projection 424 is provided on the entry side on a side 422 which depends outwardly at an acute angle β and which can be pivoted into a correspondingly shaped undercut 32 of the entry-side carrier corner 3, the height h of the offset 424 in fig. 6d here being equal to the height h of the offset 424_vIs smaller than the height h of the offset 424 of fig. 6e_vOn the outlet side, the side 421 of the lining carrier plate 4 is centrally formed as a side 423 which depends outwardly at an acute angle α.

Preferably, in order to make it easier for the lining carrier plate 4 to be pivoted into the undercut 32 of the entry-side bearing corner 3, the edge region 430 adjoining the upper side 428 and the edge region 432 adjoining the lower side 427 of the lining carrier plate 4 are designed slightly flat.

Likewise, a surface 4242 of the rectangular offset portion or offset projection 424 (in the installed state of the brake lining 4) pointing in the direction of the axis of rotation of the brake disk 5 is provided with a flattening 4243 to facilitate the pivoting movement of the brake lining 4 out of engagement with the brake carrier 1.

In this case, the offset 424 is integrally molded on the lining carrier plate 42 according to a preferred embodiment. Alternatively, it is also conceivable to fasten the lining 424 as a separate component to the lining carrier plate 42.

Fig. 7 shows a design variant of a brake carrier 1 with two brake linings 4 inserted therein, which uses the brake linings 4 shown in fig. 6d and 6 e. Fig. 8 shows the brake carrier 1 without brake lining. The asymmetrical configuration of the brake lining and the design of the component of the brake carrier 1 that receives the brake lining 4, in particular the head 33 of the entry-side carrier angle 3, and the v-shaped extension of the brake lining groove of the brake carrier formed by the carrier angles 2, 3 to one another can be easily recognized.

The friction lining 41 provided on the brake lining 4 is preferably shaped in accordance with the asymmetrical shaping of the lining carrier plate 42, as shown in fig. 10a and 10 c. The partial piece 413 of the friction lining 41, which covers the offset 424 of the lining carrier plate 42, is preferably formed in one piece with a partial piece 412 of the friction lining 41, which is preferably divided into two partial pieces 411, 412; however, in a variant of the design of a brake lining with a separately formed offset 424, the part 413 can also be mounted on the brake lining together with the offset 424. It is also conceivable that no friction lining is provided on the offset 424, as shown in fig. 10 b.

Fig. 11 and 12 show a side plan view of the brake carrier 1 and the brake lining 4 shown in fig. 7, wherein on the one hand a lining carrier plate 42 of the brake lining (fig. 11) and on the other hand a friction lining 41 of the brake lining (fig. 12) are shown. However, it can also be clearly recognized that the outlet-side support angle 2 is formed asymmetrically with respect to the inlet-side support angle 3 of the brake carrier 1 with respect to a mirror axis which passes through the brake lining 4 in the center and which runs through the axis of rotation C of the brake disk 5.

Thus, an improved force distribution is achieved by the friction-fitting support of the lining carrier plate 4 and the brake carrier 1 formed according to the invention via the inlet and outlet sides. Furthermore, a more uniform introduction of the forces transmitted from the brake linings 4 into the brake carrier 1 during braking is achieved, which is accompanied by a more uniform loading of the fixing elements of the brake and of the brake carrier 1 or of the brake caliper on the shaft carrying the brake carrier 1. Furthermore, the noise of the click is also reduced by the more precise radial introduction of the brake lining 4 into the brake carrier 1.

List of reference numerals

1 brake bracket

11 bridging piece

2 bearing angle

21 bearing surface

22 leaning surface

23 upper side

24 support surface

3 bearing angle

31 bearing surface

32 undercut

33 head part

34 support surface

4 brake lining

41 Friction lining

42 lining carrier plate

421 bearing surface

422 support surface

423 offset part

424 offset part

4241 the upper side

4242 lower side

4243 planishing section

4244 side surface

425 support surface

426 bearing surface

427 lower edge

428 upper edge

429 projection for a lining retaining spring

430 edge region

431 support surface

432 support surface

5 brake disc

6 lining retainer bracket

7 holes

8 brake caliper

100 brake carrier

101 bearing angle

102 bearing corner

103 bearing surface

104 bearing surface

105 lining carrier plate

C axis of rotation, midpoint of coordinate system

Point of action of force A

Main direction of rotation of HDR brake disc

h_BHeight of lining retaining plate

h_TeHeight of the entry-side bearing angle

h_TaHeight of bearing angle of outlet side

v: deviation of the line of force action during reverse braking

x: spacing of lining pressing force relative to lining support point

F_R: total lining friction

F_Rrw: lining friction force during reverse braking

F_arw: lining support force during reverse braking

F_Z: pressing force

F_P: gasket pressing force

F_Ra: frictional forces in the bearing surfaces of the bearing corners on the outlet side

F_Re: frictional forces in the bearing surfaces of the inlet-side bearing corners

Claims (29)

1. A motor vehicle disc brake having a brake caliper (8) overlapping a brake disc (5), a brake carrier (1) which can be fixed in a stationary manner to a vehicle and in which at least one brake lining (4) which is equipped with a lining carrier plate (42) and friction linings (41) which are fixed on the lining carrier plate is guided, wherein the brake carrier (1) has bearing angles (2, 3) of the lining carrier plate (42) which supports the brake lining (4) on the inlet side and the outlet side in a main direction of rotation (HDR) of the brake disc (5), wherein the inlet side of the brake carrier (1) has bearing angles (2, 3)The bearing corner (3) and a bearing surface (422) of the lining carrier plate (42) adjacent thereto engage with one another, characterized in that the bearing corner (2) on the outlet side and the corresponding bearing contour of the lining carrier plate (42) have a bearing surface (21) which is inclined in relation to the Y axis in its entirety, in regions, or at least in the region of the radial highest point of the lining support on the brake carrier, by an inclination angle (α), the inclination angle (α) being smaller than the force introduction angle (γ) and the coefficient of friction μ at the bearing point (A) on the bearing corner (2) on the outlet side_aWherein the Y-axis is an axis of a coordinate system in which a rotation axis of the brake disc forms a Z-axis, and the Y-axis extends through a center of gravity of the brake pad at a center of a pad groove in a circumferential direction and extends perpendicular to and intersects the rotation axis of the brake disc, and an X-axis is perpendicular to the Z-axis and the Y-axis.

2. The disc brake of claim 1, characterized in that for the inclination angle (a) it applies: alpha is more than or equal to 8 degrees and less than or equal to 30 degrees.

3. The disc brake of claim 1, characterized in that the brake lining (4) is supported at a support point (a) on the outlet-side load angle (2), which support point is located with respect to the axis of rotation of the brake disc at a force action line (F) representing the total friction force acting on the brake lining (4)_Rxges) The following is a description.

4. The disc brake of claim 2, characterized in that the brake lining (4) is supported at a support point (a) on the outlet-side load angle (2), which support point is located with respect to the axis of rotation of the brake disc at a force action line (F) representing the total friction force acting on the brake lining (4)_Rxges) The following is a description.

5. The disc brake of claim 1, characterized in that the bearing angle (2) on the outlet side is configured to be lower than the bearing angle (3) on the inlet side.

6. The disc brake of claim 4, characterized in that the bearing angle (2) on the outlet side is configured to be lower than the bearing angle (3) on the inlet side.

7. The disc brake of claim 3, characterized in that the highest support point (A) at the bearing angle (2) on the outlet side has, as seen in the X-direction, up to the line of force action (F)_Rxges) Distance (h)>0 and is located below the line of force action.

8. The disc brake of claim 6, characterized in that the highest support point (A) at the bearing angle (2) on the outlet side has, as seen in the X-direction, up to the line of force action (F)_Rxges) Distance (h)>0 and is located below the line of force action.

9. The disc brake of claim 7, characterized in that the support point (A) at the bearing angle (2) on the outlet side is up to the line of force action (F)_Rxges) Is that the brake lining (4) is at the force action line (F)_Rxges) At least 0.1 times the length (I) in the direction.

10. The disc brake of claim 8, characterized in that the support point (A) at the bearing angle (2) on the outlet side is up to the line of force action (F)_Rxges) Is that the brake lining (4) is at the force action line (F)_Rxges) At least 0.1 times the length (I) in the direction.

11. Disc brake according to claim 3, characterized in that the bearing angle (3) of the inlet side is higher than the forceLine of action (F)_Rxges) The intersection with the entry-side carrying corner (3).

12. The disc brake of claim 10, characterized in that the load-bearing angle (3) on the inlet side is higher than the line of force action (F)_Rxges) The intersection with the entry-side carrying corner (3).

13. The disc brake of claim 1, characterized in that the support face (422) of the lining carrier plate (42) adjacent to the entry-side bearing corner (3) of the brake carrier (1) has an offset (424) which engages into an undercut (32) on the entry-side bearing corner (3) corresponding to the offset (424).

14. The disc brake of claim 12, characterized in that the support face (422) of the lining carrier plate (42) adjacent to the entry-side bearing corner (3) of the brake carrier (1) has an offset (424) which engages into an undercut (32) on the entry-side bearing corner (3) corresponding to the offset (424).

15. The disc brake of claim 1, characterized in that the bearing corner (3) of the inlet side of the brake carrier (1) and the support face (422) of the lining carrier plate (42) adjacent thereto engage in a form-fitting manner with one another.

16. The disc brake of claim 14, characterized in that the bearing corner (3) of the inlet side of the brake carrier (1) and the support face (422) of the lining carrier plate (42) adjacent thereto engage in a form-fitting manner with one another.

17. The disc brake of claim 16, characterized in that the disc brake is a commercial vehicle disc brake.

18. Brake lining (4) for a disc brake, having a lining carrier plate (42) and a friction lining (41) fixed thereto, wherein the lining carrier plate (42) has lateral support faces (421, 422) for supporting on lateral inner walls of a bearing corner (3) of a brake carrier (1) or on a further support element, wherein an offset (423, 424) is provided on at least one of the lateral support faces (421, 422) which is fixed in a form-fitting manner on one of the lateral inner walls of the bearing corner (3) of the brake carrier (1) or on the further support element, characterized in that the lining carrier plate has a bearing contour in the circumferential direction for bearing on a brake carrier on an outlet side and the bearing contour of the outlet side of the carrier plate (42) has a support face (21) which is inclined relative to the Y axis by an inclination angle (α), the inclination angle (α) being smaller than the coefficients of the force introduction angle (γ) on the outlet side and of the friction lining at a support point (a) at the bearing corner (2)_aThe sum of the arctangent of (c).

19. A brake lining according to claim 18, characterised in that the disc brake is a disc brake according to any one of claims 1 to 17.

20. A brake lining according to claim 18, characterized in that the angle of inclination (α) lies between 8 ° and 30 °.

21. A brake lining according to one of claims 18 to 20, characterized in that a rectangular offset is formed on the lateral support face of the lining carrier plate on the entry side and the offset on the entry side is formed close to the underside (427) of the lining carrier plate (42).

22. A brake lining according to claim 21, characterized in that the offset (423, 424) is formed as a projection from the lateral support surface (421, 422).

23. A brake lining as claimed in claim 22, characterized in that the offset is trapezoidal in design.

24. A brake lining according to claim 23, wherein the offset is a rectangular projection.

25. Brake lining according to claim 21, characterized in that the lining carrier plate (42) is asymmetrically shaped as a result of the offset (423, 424).

26. Brake lining according to claim 24, characterized in that the lining carrier plate (42) is asymmetrically shaped as a result of the offset (423, 424).

27. A brake lining according to any one of claims 18 to 20, wherein the angle covered by the friction surface of the brake lining in the circumferential direction is greater than 25 °.

28. A brake lining according to claim 26 wherein the angle covered in the circumferential direction by the friction surface of the brake lining is greater than 25 °.

29. A brake lining according to claim 27, wherein the angle is greater than 30 °.