Brake Shoe

Abstract

Brake shoe, in particular of a drum brake for utility vehicles, includes a lining plate and a bridge unit, wherein the bridge unit is formed as a one-piece body comprising at least two bridge plates.

Claims

1. A brake shoe for utility vehicles, comprising: a lining plate; and a bridge unit; wherein the bridge unit is a one-piece body comprising at least two bridge plates.

2. The brake shoe as claimed in claim 1, wherein the bridge unit is a deep-drawn part, and wherein the bridge unit and the lining plate are connected via a welded connection.

3. The brake shoe as claimed in claim 2, wherein the bridge unit has a connecting plate which connects the two bridge plates.

4. The brake shoe as claimed in claim 3, wherein the connecting plate has at least one opening.

5. The brake shoe as claimed in claim 4, wherein the bridge plates extend substantially in the form of a curve with reference to a mid-plane of the lining plate.

6. The brake shoe as claimed in claim 5, wherein the bridge plates extend in a convex curve.

7. The brake shoe as claimed in claim 5, wherein the bridge plates are inclined toward a mid-plane of the lining plate.

8. The brake shoe as claimed in claim 7, wherein a stiffness of the bridge unit increases towards a center of the brake shoe.

9. The brake shoe as claimed in claim 7, wherein the bridge unit comprises a trapezoidal shape in cross section.

10. The brake shoe as claimed in claim 9, comprising two bridge units which are connected to each other along a dividing plane.

11. The brake shoe as claimed in claim 10, wherein the two bridge units are welded to each other along the dividing plane.

12. The brake shoe as claimed in claim 10, wherein the bridge unit includes at least one bearing section.

13. The brake shoe as claimed in claim 12, wherein the bearing section is configured for the arrangement of a needle bearing.

14. The brake shoe as defined in claim 13, wherein the bearing section is at least one of spherical and cylindrical.

15. The brake shoe as claimed in claim 12, wherein a needle bearing is arranged on the functional area.

16. The brake shoe as claimed in claim 1, wherein the bridge plates extend substantially in the form of a curve with reference to a mid-plane of the lining plate.

17. The brake shoe as claimed in claim 16, wherein the bridge plates extend in a convex curve.

18. The brake shoe as claimed in claim 1, wherein the bridge plates are inclined toward a mid-plane of the lining plate.

19. The brake shoe as claimed in claim 1 wherein a stiffness of the bridge unit increases towards a center of the brake shoe.

20. The brake shoe as claimed in claim 1, wherein the bridge unit comprises a trapezoidal shape in cross section.

21. The brake shoe as claimed in claim 1, comprising two bridge units which are connected to each other along a dividing plane.

22. The brake shoe as claimed in claim 1, wherein the bridge unit includes at least one bearing section.

23. The brake shoe as claimed in claim 1, wherein a needle bearing is arranged on the functional area.

24. A bridge unit of a brake shoe for drum brakes for utility vehicles, which is formed as a one-piece body and has two bridge plates.

25. The bridge unit as claimed in claim 24, further comprising: a functional area which is part of the one-piece body.

26. A drum brake, comprising: at least one brake shoe as claimed in claim 1; and a cam element configured to actuate the at least one brake shoe; wherein a contact surface of the cam element has a friction-reducing layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further advantages and features can be gathered from the following description of preferred embodiments of the brake shoe according to the invention and of the drum brake according to the invention, with reference to the appended figures. Here, individual features of the individual embodiments can be combined with one another within the scope of the invention.

[0017] FIG. 1 shows an embodiment of a bridge unit in a perspective illustration;

[0018] FIG. 2 shows the bridge unit known from FIG. 1, viewed along a longitudinal direction/circumferential direction;

[0019] FIG. 3 shows the section A-A as sketched in FIG. 2;

[0020] FIG. 4 shows the section B-B as sketched in FIG. 3;

[0021] FIG. 5 shows a plan view of the bridge unit known from FIG. 1;

[0022] FIG. 6 shows a perspective illustration of an embodiment of a brake shoe;

[0023] FIG. 7 shows a further perspective illustration of an embodiment of a brake shoe;

[0024] FIG. 8 shows an embodiment of a cam element;

[0025] FIG. 9 shows a further embodiment of a cam element, the brake shoe being provided with needle bearings;

[0026] FIG. 10 shows an embodiment of a needle bearing; and

[0027] FIG. 11 shows an embodiment of a bridge unit with a needle bearing arranged thereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] FIG. 1 shows in a perspective illustration a bridge unit 40 comprising two bridge plates 42, which are connected via transverse plates 45. The bridge unit 40 extends along a longitudinal direction L (or along a circumferential direction of the brake drum) and, at its respective ends, respectively forms functional areas 60, the (rear) one being formed spherically, in particular in the shape of a ball, the front one more likely cylindrically. It is possible to see clearly the one-piece configuration on the bridge unit 40, comprising the two bridge plates 42, the transverse plates 45 and the functional areas 60. The bridge unit 40 forms a circumferential arrangement surface 41, via which the arrangement and fixing on a brake lining, not illustrated here, is carried out, for example via a welded connection. Here, the great advantage of the bridge unit 40 becomes clear, specifically that only one component has to be handled. In addition, the decreasing height of the bridge plates 42 toward the functional areas 60 is shown clearly. The height of the bridge plates 42 is therefore greatest in the center of the bridge unit 40 and decreases steadily or continuously toward the ends.

[0029] FIG. 2 shows the bridge unit 40 known from FIG. 1, viewed along the longitudinal direction L or in the circumferential direction. It is possible to see the substantially symmetrical or axially symmetrical configuration of the bridge unit 40 with reference to a mid-plane M. In particular, in the view illustrated here, the connection of the two bridge plates 42 via the transverse plate 45 is illustrated. The functional area 60 extends away downward from the transverse plate 45. The sketched section A-A is illustrated in FIG. 3.

[0030] FIG. 3 shows the section A-A as sketched in FIG. 2. It is possible to see in particular the course of the arrangement surface 41 and the lateral contour of the two functional areas 60. It can also be seen that a height of the bridge unit 40 decreases toward its ends. The sketched section B-B is illustrated in FIG. 4.

[0031] FIG. 4 shows in particular the substantially trapezoidal configuration of the cross section of the bridge unit 40. In particular, the trapezoidal shape results from the position and orientation of the bridge plates 42 relative to the connecting plate 44. Thus, a width b40 of the bridge unit and a width b44 of the connecting plate 44 result, an advantageous ratio here lying in a range from about 1.0 to 2.0, preferably 1.3 to 1.7. Indicated dashed is the orientation of a lining plate. Between the lining plate and the bridge plate 42 there is an angle which, in preferred embodiments, for example, lies in a range from about 90 to 130, preferably 92 to 105.

[0032] FIG. 5 shows the bridge unit to be seen in FIG. 3 folded downward. Here, in particular the course of the bridge plates 42, which can substantially be designated as convex, becomes clear. In this case, the bridge plates 42 enclose an angle which, for example, lies in a range from about 2 to 30, preferably 4 to 25 or 10 to 20. The width ratios of the bridge unit 40 also become clear, a maximum width b.sub.max in a central region of the bridge unit lying at about 100 mm to 120 mm, while a minimum width b.sub.min lies in a range from about 40 mm to 50 mm. The minimum width is measured approximately in the area of the functional areas 60.

[0033] FIG. 6 shows a brake shoe 10, comprising a lining plate 20, to which two bridge units 40 are fixed via a welded connection. The two bridge units 40 are welded to each other along a welded connection 50 along a dividing plane T. The bridge units 40 comprise lateral bridge plates 42 and transverse plates 45. Moreover, the bridge plates 42 are connected by connecting plates 44, which extend in relation to the lining plate 20 in such a way that the connecting plates 44 have a greater radius of curvature than the lining plate 20. The connecting plate 44 forms an elongated opening 46. The bridge units 40 each comprise a functional area 60, both being formed spherically or in a ball shape here.

[0034] FIG. 7 shows a similar configuration of a brake shoe 10 as known from FIG. 6. The difference here resides in the fact that here only one bridge unit 40 is provided. Moreover, a right-hand functional area 60 is formed cylindrically here.

[0035] FIG. 8 shows a cam element 80 which is used to actuate two brake shoes 10, which are illustrated only in part here. The introduction of force is carried out onto the corresponding functional areas 60 of the brake shoes 10 and the bridge unit 40. A friction-reducing layer 86, which is arranged on the cam element 80 and which improves the frictional behavior between the cam element 80 and the functional areas 60, is indicated.

[0036] FIG. 9 substantially shows the configuration known from FIG. 8, here a needle bearing 62 being arranged on a functional area 60 of a brake shoe 10. Here, too, the cam element 80 is provided with a friction-reducing layer 86.

[0037] FIG. 10 shows the needle bearing 62 in a detailed illustration. Here it is possible to see in particular a bearing cage 63, which can be rotatably fixed to a functional area 60 of the bridge unit 40. Indicated here is a corresponding axis of rotation D, via which ultimately the (rotatable) arrangement on the corresponding functional area of the bridge unit is carried out.

[0038] FIG. 11 shows the arrangement of a needle bearing 62 with its bearing cage 63 on a bridge unit 40 and the functional area 60 of the latter. Appropriate mobility about an axis of rotation D is provided.

LIST OF DESIGNATIONS

[0039] 10 Brake shoe [0040] 20 Lining plate [0041] 40 Bridge unit [0042] b40 Width of the bridge unit [0043] b.sub.min Minimum width (of the bridge unit) [0044] b.sub.max Maximum width (of the bridge unit) [0045] 41 Arrangement surface [0046] 42 Bridge plates [0047] 44 Connecting plate [0048] 45 Transverse plate [0049] 46 Opening [0050] 50 Welded seam [0051] 60 Functional area, bearing section, force introduction area [0052] 62 Needle bearing [0053] 64 Bearing cage [0054] 80 Cam element [0055] 86 Friction-reducing layer [0056] M Mid-plane [0057] T Dividing plane [0058] L Longitudinal direction [0059] D Axis of rotation [0060] , Angle