Brake caliper consisting of cast iron

Abstract

The invention relates to a brake caliper consisting of cast iron for a disc brake for a commercial vehicle, having a receiving space (2), which can be closed by a closure cover and is arranged in a caliper housing (1), for a bridge (9) of an application device, said bridge receiving at least one brake piston, wherein in the mounted position the bridge (9) can be displaced along at least two guide paths (4) of the caliper housing (1), the brake caliper being designed such that the guide paths (4) lying opposite one another transverse to the displacement direction of the bridge (9) are concave in cross-section.

Description

[0001] DESCRIPTION

[0002] Cast iron brake caliper

[0003] The invention relates to a cast iron brake caliper of a disc brake according to the preamble of claim 1.

[0004] Such a brake caliper of a disc brake, in particular a sliding-caliper disc brake, serves to accommodate functional parts such as an application device, which is positioned in a receiving space of a caliper housing. This caliper housing has an insertion opening that can be closed by a cover.

[0005] A component of the application device is a pneumatically or electric motor-operated brake lever which, when actuated, acts on a bridge which is movably mounted in the receiving space and in which at least one brake piston is positioned.

[0006] When braking, the brake piston presses a brake pad on the application side against a brake disc on the vehicle side.

[0007] The bridge is guided on molded guideways of the brake calliper, with the bridge having areas corresponding to the guideways.

[0008] A disc brake with the aforementioned features is known from WO 2011 / 101076 A1.

[0009] To form the guideways, the side walls of the brake calliper that define the receiving space are made very solid, i.e. thick, whereby these walls also form the outer walls of the calliper housing.

[0010] To ensure optimal sliding of the bridge on the guideways, these are machined, whereby the guideways of the brake caliper are designed to be flat according to the state of the art, which naturally makes machining in the caliper housing more difficult and is only possible with a relatively high manufacturing effort, which leads to high manufacturing costs, so that the known brake caliper does not meet the constant demands for cost minimization.

[0011] The high material usage required to form the guideways on the walls of the caliper housing also leads to relatively high costs, as well as to a correspondingly high weight of the brake caliper as a whole, also accompanied by corresponding costs of the casting.

[0012] The invention is based on the object of further developing a brake caliper of the generic type in such a way that its manufacturing costs are reduced and its service life is improved.

[0013] This object is achieved by a brake caliper having the features of claim 1.

[0014] According to the invention, the guideways are now concave in cross-section transverse to the direction of displacement of the bridge, preferably with the same radius of curvature. This means that the guideways have identical contours.

[0015] This now makes it possible to insert a rotating, cutting tool, for example a milling cutter or the like, through an adjustment opening for components of an adjustment device opposite the insertion opening for the clamping device, which results in a significantly shortened machining time, with correspondingly reduced manufacturing costs.

[0016] According to a further concept of the invention, the guideways are arranged at a distance from one another in the X, Y and Z directions, which results in less material being used than in the prior art, thereby lowering both the material costs of the cast iron brake caliper and the weight of the brake caliper. The latter contributes to a weight-optimised design, which is increasingly required, particularly with regard to fuel savings. The concave, i.e. circular, arc-shaped design of the guideways also results in a smaller number of guideways compared to the prior art, since the bridge, which has convex guide strips in cross-section with the same radius of curvature as the guideways, is secured in every lateral direction.

[0017] In the case of the flat guideways known from the state of the art, however, the guideways must be arranged not only on the upper and lower inner walls of the receiving space, but also on both lateral inner walls.

[0018] The bridge's guide rails are also molded onto the cast iron bridge. The axial length of the guide rails can be dimensioned such that the bridge rests against two guideways arranged one behind the other in the axial direction in any sliding position.

[0019] Furthermore, the new brake caliper can be manufactured without any additional design or manufacturing effort. Only the core geometry of the casting mold needs to be designed accordingly.

[0020] The reduced material thickness in the area of ​​the guideways made possible by the invention ensures that the casting quality of the brake caliper is improved, since, for example, the risk of the formation of blowholes, which is a problem with a brake caliper according to the state of the art, no longer exists, at least only to a negligible extent.

[0021] This also results in higher material hardness, which minimizes wear on the guideways.

[0022] Furthermore, the guideways can be designed to be relatively narrow and yet still fully perform the guiding function on the one hand and the position securing of the bridge on the other.

[0023] As is well known, the brake caliper or caliper housing is made of spheroidal graphite cast iron (GJS), in which carbon is present in the form of spheroidal graphite. This material is characterized by strength comparable to steel, as well as high toughness and tensile strength, which result in properties that are particularly advantageous for the function of the brake caliper and are therefore desirable.

[0024] Further advantageous embodiments of the invention are characterized in the subclaims.

[0025] An embodiment of the invention is described below with reference to the accompanying drawings.

[0026] They show:

[0027] Fig. 1 shows a caliper housing of a brake caliper according to the invention in a perspective view,

[0028] Fig. 2 shows a bridge that can be inserted into the saddle housing, also shown in perspective.

[0029] Figure 1 shows a caliper housing 1 of a brake caliper made of cast iron, with a receiving space 2 into which a bridge 9 of an application device, shown as a detail in Figure 2, can be inserted.

[0030] For this purpose, an insertion opening 3 is provided which is delimited by an edge-side contact surface 6, this contact surface 6 having threaded holes 7 for screwing a closure cover closing the insertion opening 3.

[0031] In the receiving space 2, guideways 4 are arranged, two of which are clearly arranged opposite each other transversely to the direction of displacement and which are concave in shape.

[0032] Not visible, but arranged on the upper side of the receiving space 2 opposite the base 8, are additional guideways 4, also with concave surfaces, whereby these guideways 4, lying in a cross-sectional plane, form a first group. The guideways 4 lie on a common imaginary circular path 5, which indicates the circumference of a cutting tool. To machine the concave surfaces of the guideways 4, the cutting tool, for example a milling head, can be inserted through an adjuster opening located on the rear of the saddle head, opposite the insertion opening 3.

[0033] According to a further variant of the saddle housing 1, in addition to the guideways 4 arranged at a distance from one another transversely to the direction of displacement of the bridge 9, further guideways 4 are arranged in the same configuration at an axial distance from the guideways 4 adjacent to the insertion opening 3, forming a second group, which, however, are not visible in the figure.

[0034] To guide the bridge 9 on the guideways 4, the bridge 9 has, as can be clearly seen in Figure 2, guide rails 10 which have the same radius of curvature as the guideways 4, but are convexly curved in the circumferential direction of the circular path 5.

[0035] With a corresponding length of the guideways 4, as well as the guide rails 10, only the four guideways 4 arranged along the circular path 5 in correspondence with the guide rails 10 of the bridge 9 provide sufficiently secure guidance. However, it is also conceivable that when the guideways 4 are arranged one behind the other in the direction of displacement of the bridge 9, their clear distances in the axial direction are smaller than the axial length of the guide rails 10, so that a secure contact of the bridge 9 with the guideways 4 is guaranteed in all cases.

[0036] Both the guideways 4 in the saddle housing 1 and the guide rails 10 of the bridge 9 are formed during casting, whereby only the core geometry of the respective casting mold needs to be adapted.

[0037] 1 saddle housing

[0038] 2 Receiving space 3 Insertion opening

[0039] 4 guideway

[0040] 5 circular path

[0041] 6 contact surface

[0042] 7 Threaded hole 8 Base

[0043] 9 Bridge

[0044] 10 Guide rail

Claims

Claims 1 . A cast iron brake caliper for a disc brake for a commercial vehicle, comprising a receiving space (2) arranged in a caliper housing (1) which can be closed by a cover and which is intended for receiving a bridge (9) of an application device which receives at least one brake piston, the bridge (9) being displaceable in the mounted position along at least two guide tracks (4) of the caliper housing (1), characterized in that the guide tracks (4) lying opposite one another transversely to the direction of displacement of the bridge (9) are concave in cross-section.

2. Brake calliper according to claim 1, characterized in that at least two guide tracks (4) are arranged at a distance from one another on the bottom of the receiving space (2) and on the opposite inner wall, which together form a first group.

3. Brake caliper according to claim 1 or 2, characterized in that a second group of guide tracks (4) is arranged at an axial distance from the first group.

4. Brake calliper according to one of the preceding claims, characterized in that the opposing guide tracks (4) of a group are arranged in a cross-sectional plane.

5. Brake caliper according to one of the preceding claims, characterized in that all guide tracks (4) have an identical contour.

6. Brake calliper according to one of the preceding claims, characterized in that the guide tracks (4) of the respective group are arranged on a common imaginary circular path (5).

7. Brake calliper according to one of the preceding claims, characterized in that the bridge (9) has guide strips (10) which are convexly curved according to the radius of curvature of the guide tracks (4).

8. Brake calliper according to one of the preceding claims, characterized in that the convex curvature of the guide rails (10) and the concave curvature of the guide tracks (4) run transversely to the direction of displacement.

9. Brake calliper according to one of the preceding claims, characterized in that the axial length of the guide rails (10) is greater than the clear distance between the guide tracks (4) of the two groups.

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