Disc brake for a vehicle, particularly for a commercial vehicle

Abstract

A disc brake for a vehicle, particularly for a commercial vehicle, includes a brake caliper which straddles a brake disc and in which an application device is arranged, a single-piece rotary lever which has an eccentric element, and at least one brake plunger which is designed as a power screw arrangement having a rotational axis and with which, when the rotary lever is actuated, at least one brake pad can be pressed against the brake disc. The rotary lever is arranged in the brake caliper such that it can pivot relative thereto, and is supported directly or by way of one or more elements connected therebetween, on said brake caliper, in at least one support region. The rotary lever, which can pivot relative to the brake plunger, has at least one convexly-formed section on the side thereof that lies opposite the support point on the brake caliper, and this section lies against a matching concave end face in the axial extension of the rotational axis of said power screw arrangement.

Claims

1. A disc brake for a vehicle, comprising: a brake caliper which is configured to straddle a brake disc and in which a brake application device is arranged; a single-piece rotary lever which has an eccentric; and at least one brake plunger which is configured as a threaded spindle arrangement with a rotational axis, and by way of which at least one brake pad is pressable against the brake disc upon actuation of the rotary lever, wherein the rotary lever is arranged in the brake caliper so as to pivot relative thereto, and is supported on the brake caliper in at least one supporting region directly or via one or more elements which are connected in between, the rotary lever which is pivotable with respect to the brake plunger, has at least one convexly shaped section on a side which lies opposite the supporting region on the brake caliper, the at least one convexly shaped section abutting directly or via a plain bearing against a concave end side of a respective one of the at least one brake plunger which is adapted to the at least one convexly shaped section, in an axial extension of the rotational axis of the threaded spindle arrangement, on a side of the rotary lever which lies opposite the at least one convexly shaped section, the rotary lever is supported on at least one ball which bears against a bearing block which is held on the brake caliper, the ball lies in a recess which is adapted to its shape, and the bearing block is configured as a separate component.

2. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section is configured as a spherical section.

3. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section is configured as an elliptically shaped section.

4. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section is configured as a section shaped in a manner of a barrel section.

5. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section is configured as a cylinder section, a curvature extending in a pivoting direction of the rotary lever.

6. The disc brake as claimed in claim 1, further comprising: a gear mechanism wheel, which is operatively connected to an adjusting device, is arranged fixedly on the brake plunger so as to rotate with it, wherein the concave end side, against which the at least one convexly shaped section bears, is provided on the brake plunger or on the gear mechanism wheel.

7. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section and/or the concave end side which bears against it, are precision machined by way of vibratory grinding, lapping, polishing, honing, eroding or rolling.

8. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section and/or the concave end side of the brake plunger which is adapted to it are provided with a bearing shell.

9. The disc brake as claimed in claim 8, wherein the at least one convexly shaped section or the bearing shell of the rotary lever corresponds in terms of the extent in the pivoting direction of the rotary lever to a maximum pivoting travel of the rotary lever.

10. The disc brake as claimed in claim 1, wherein the at least one convexly shaped section is configured on the eccentric of the rotary lever.

11. The disc brake as claimed in claim 1, further comprising: at least one anti-friction body provided on the rotary lever on the side which lies opposite the at least one convexly shaped section.

12. The disc brake as claimed in claim 11, wherein at least one bearing device is provided between the anti-friction body and the rotary lever and/or between the anti-friction body and the brake caliper.

13. The disc brake as claimed in claim 12, wherein the at least one bearing device is configured as a plain bearing shell.

14. The disc brake as claimed in claim 12, wherein the at least one bearing device is configured as an anti-friction bearing shell.

15. The disc brake as claimed in claim 11, wherein a bearing shell on the at least one convexly shaped section of the rotary lever and/or a plain bearing shell are formed to receive an anti-friction body of a composite plain bearing.

16. The disc brake as claimed in claim 6, wherein the gear mechanism wheel, which is connected fixedly to the brake plunger so as to rotate with it, and an adjusting device gear mechanism wheel which corresponds therewith, are arranged in a driver device which is held on the adjusting device so as to be displaced axially but secured against rotation.

17. The disc brake as claimed in claim 16, wherein the driver device comprises two plates which are arranged parallel to and at a spacing from one another.

18. The disc brake as claimed in claim 17, further comprising: spacer sleeves provided in order to space the two plates apart, through which spacer sleeves screws are guided.

19. The disc brake as claimed in claim 1, wherein the bearing block has a cylindrical journal which adjoins a support pin of greater diameter and which is inserted into a bore of the brake caliper.

20. The disc brake as claimed in claim 1, wherein at least one of two bearing blocks which are arranged parallel to and at a spacing from one another is held on the brake caliper in a manner which compensates for tolerances.

21. The disc brake as claimed in claim 1, wherein the bearing block is configured as a cold pressed part.

22. The disc brake as claimed in claim 19, wherein a stepped supporting face is formed between the support pin and the journal, which supporting face extends circumferentially transversely with respect to the longitudinal axis of the bearing block, and bears against a machined bearing face of the brake caliper.

23. The disc brake as claimed in claim 22, wherein the bearing block is rotationally symmetrical.

24. The disc brake as claimed in claim 20, wherein a journal of the two bearing blocks is connected fixedly to the brake caliper.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a disc brake according to the prior art in a partially sectioned plan view.

(2) FIG. 2 shows a brake application device according to an embodiment of the invention in a perspective view.

(3) FIG. 3 shows one exemplary embodiment of the brake application device in a sectioned side view.

(4) FIG. 4 shows a detail of the brake application device according to FIG. 3 in a rear-side perspective view.

(5) FIG. 5 shows a further exemplary embodiment of the brake application device in a diagrammatic perspective view.

(6) FIG. 6 shows the brake application device according to FIG. 5 in a diagrammatic sectioned side view.

(7) FIG. 7 shows a detail of the brake application device in a perspective front view.

(8) FIG. 8 shows the brake application device in a side view.

(9) FIG. 9 shows a further exemplary embodiment of the invention in a sectioned, perspectively illustrated side view.

(10) FIG. 10 shows a part view of FIG. 9, likewise in a perspective illustration.

(11) FIG. 11 shows the part view according to FIG. 10 in a tilted side view.

(12) FIG. 12 shows a detail of the brake application device according to FIG. 9 in a perspective rear view.

(13) FIG. 13 shows a part view of the detail according to FIG. 12.

(14) FIG. 14 shows the design variant according to FIG. 9 in a sectioned plan view.

(15) FIG. 15 shows a detail of FIG. 14 in a sectioned plan view.

(16) FIG. 16 shows a sectioned side view of the brake application device according to the line XVI-XVI in FIG. 14.

DETAILED DESCRIPTION OF THE DRAWINGS

(17) FIG. 1 shows a diagrammatic view of a disc brake according to the prior art, having a brake caliper 1 which straddles a brake disc 2, is configured as a sliding caliper, and in which two brake pads 3 are arranged which are pressed against the brake disc 2 during operation, that is to say in the case of a braking operation.

(18) Here, first of all, the brake application-side brake pad 3 is pressed against the brake disc 2 by means of a brake application device 8, whereas subsequently, on account of the reaction forces, the reaction-side brake pad 3 is pressed against the brake disc 2 by way of driving of the brake caliper 1 which is displaced.

(19) The brake application device has a central threaded spindle arrangement 4 which can be pressed against the brake application-side brake pad 3 in an axially displaceable manner via a rotary lever 9.

(20) The threaded spindle arrangement 4 consists of a rotatable screw 6 and a threaded sleeve 7 which is held such that it cannot rotate with respect to said screw 6. The internal thread of the threaded sleeve 7 engages into the external thread of the screw 6. On the side which faces the action-side brake pad 3, a plate-shaped pressure piece 10 which bears against the brake pad 3 in the case of braking is connected on the threaded sleeve 7.

(21) An adjuster 5 is connected to the screw 6 for compensating for an air play which changes in a wear-induced manner, that is to say the spacing between the brake pad 3 and the brake disc 2.

(22) In order to protect a receiving chamber of the brake caliper 1, which receiving chamber receives the brake application device 8 and the adjuster 5, an assembly opening of the brake caliper 1 is closed on that side which faces the brake disc 2 by way of a closure plate 11 which is connected to the brake caliper 1 by way of screws 12.

(23) The threaded spindle arrangement 4 passes through the closure plate 11, whereas the adjuster 5 is supported on the closure plate 11 in a manner which is loaded by way of a compression spring 15.

(24) The passage region of the threaded spindle arrangement 4 is sealed by way of a bellows 13 which bears sealingly on one side against the closure plate 11 and on the other side against the pressure piece 10 or against the threaded spindle arrangement 4.

(25) The rotary lever 9 bears pivotably against the threaded spindle arrangement 4 via a ball 36 as an intermediate element, just like it is supported via balls 34 on the brake caliper 1. To this end, on that side of the rotary lever 9 which faces away from the threaded spindle arrangement 4 and forms a caliper head, the brake caliper 1 has two formed bearing blocks 33 which are arranged parallel to and at a spacing from one another, protrude into a receiving space of the brake caliper 1, and have a recess 35 which is adapted to the ball 34 which lies in it in order to receive the balls 34 on the side of said bearing blocks 33 which faces the rotary lever 9.

(26) FIGS. 2-4 depict a part of the brake application device 8. The rotary lever 9, which is manufactured in one piece preferably by way of forging, tumbling or a comparable forming process, is configured as an eccentric 16 (or as an eccentric section) at its one end, whereas a coupling, in particular in the form of a depression 17, is preferably provided at the other end of the rotary lever 9. A tappet of a brake cylinder engages or can engage into the coupling 17, which tappet can in turn be actuated, for example, pneumatically and/or by electric motor.

(27) As can be seen, in particular, in FIGS. 2 and 3, the eccentric 16 of the rotary lever 9 lies directly in an axial extension of the threaded spindle arrangement 4, of which merely the screw 6 is depicted here, in particular in an axial extension of a rotational axis D which corresponds to the rotational axis of the screwing movement between the threaded sleeve 7 and the screw 6.

(28) On the opposite side of the eccentric 16, a channel 19 is configured in the eccentric 16 of the rotary lever 9, in which channel 19 a bearing device, in particular a (plain) bearing shell 18, is arranged in the example.

(29) A cylindrical anti-friction roller 20 lies in the bearing device, in the bearing shell 18 in the example, which cylindrical anti-friction roller 20 is supported at a supporting point which is provided on the caliper head of the brake caliper 1 and can be a bearing point. Here, the anti-friction roller 20 preferably configures a pivoting bearing for the rotary lever 9, which can be seen particularly clearly in FIG. 4.

(30) According to the invention, on its side which lies opposite the anti-friction roller 20 and forms the eccentric 16, the rotary lever 9 is provided with a convexly shaped section 21 which bears against a concave end side 23 of the screw 6, which end side 23 is adapted to said convexly shaped section 21. The curvature of the convexly shaped section 21 is preferably oriented in an opposed manner with respect to the curvature of the eccentric 16 of the rotary lever 9.

(31) In the example according to FIGS. 2 and 3, the section 21 is configured as a section of a cylinder shell, the curvature of which extends in the pivoting direction of the rotary lever 9. Here, the section 21 is covered by way of a bearing shell 22, preferably as a composite bearing which is otherwise dimensioned in such a way that it bears against the concave end side 23 of the screw 6 during the entire pivoting travel of the rotary lever 9.

(32) In another design variant, the convexly shaped section 21 of the rotary lever 9 is configured as a spherical section, whereas the end side 23 of the screw 6 is then designed as a dome, in which the section 21 or the bearing shell 22 lies.

(33) Whereas merely one brake plunger, that is to say one screw 6, is shown in the example, it goes without saying that there is also the possibility to realize the invention in the case of two brake plungers or two threaded spindle arrangements 4 which are arranged parallel to and at a spacing from one another.

(34) FIG. 5 depicts a brake application device 8 as a detail, the functional configuration of which brake application device 8 corresponds to that in FIG. 1 which represents the prior art. That is to say, a central brake plunger is provided here in the form of a threaded spindle arrangement 4, having an adjuster 5 which is arranged adjacently with respect thereto and by way of which a gearwheel 25 of a gearwheel mechanism 24 can be driven, which gearwheel 25 is connected fixedly so as to rotate with it.

(35) In order to transmit the rotational movement for the purpose of an air play compensation, the gearwheel 25 is in engagement with a gearwheel 26 which is connected fixedly to the screw 6 so as to rotate with it. The result is that the threaded sleeve 7 which is guided on the screw 6 is adjusted axially in the case of a rotation of the gearwheel 26 and therefore of said screw 6.

(36) The arrangement of the gearwheel 26 can also be seen in FIGS. 6 and 8.

(37) In the example which is shown in FIG. 6, the convex section 21 of the rotary lever 9 is supported via the bearing shell 22 on an attachment 32 of the gearwheel 26, to which end the gearwheel 26 in the form of a spur gear has a bottom which is closed to this extent with the elevated attachment 32, which can be seen particularly clearly in FIG. 7, in which the rotary lever 9 and the gearwheel 26 are depicted in interaction in a perspective illustration.

(38) In a deviation from this structural solution, FIG. 8 shows a variant, in which the convex section 21 of the rotary lever 9 bears against the facing end side of the screw 6, likewise with the bearing shell 22 being positioned in between, the end face 23 of the screw 6 being adapted to this end to the convex shape of the section 21.

(39) It can be seen in FIGS. 5 and 6 that the two gearwheels 25, 26 of the gearwheel mechanism 24 are positioned in a driver device 27 which is formed from two plates 28 which are arranged parallel to and at a spacing from one another.

(40) Said plates 28 in turn are connected to one another by way of screws 29, the spacing between the two plates 28 being formed by way of spacer sleeves 30 which are guided on the screws 29, as a result of which an intermediate space is provided for receiving the gearwheel mechanism 24. In order to form the intermediate space, at least one of the two plates 28, preferably both plates 28, can be provided with beads which protrude into the intermediate space and, for example, are welded to one another.

(41) In the case of pivoting of the rotary lever 9 in order to apply the brake, the threaded spindle arrangement 4 is displaced axially in the direction of the brake pad 3 via the eccentric 16 (FIG. 1), with driving of the gearwheel 26. By means of the driver device 27, the gearwheel 25 of the adjuster 5 is at the same time also driven, to which end the gearwheel 25 is held on the adjuster 5 fixedly so as to rotate with it but in an axially displaceable manner. Since the gearwheels 25, 26 rotate with respect to the plates 28 during operation, sliding rings 31 are provided in order to reduce a frictional resistance between the gearwheels 25, 26 and the plates 28.

(42) Otherwise, the restoring of the threaded spindle arrangement 4 and therefore also of the gearwheel 25 after the brake is released takes place by way of a compression spring 14 which is supported on one side on the closure cover 11 and on the other side on the associated plate 28 and is guided on the threaded spindle arrangement 4.

(43) FIGS. 9-16 show a further design variant of the invention, in which the bearing blocks 33 which are arranged parallel to and at a spacing from one another are held as separate components in the brake caliper 1.

(44) To this end, each bearing block 33 has a support pin 39 which is of conical configuration in the example and at the one end of which a journal 40 is formed which is plugged into a bore 41 of the brake caliper 1.

(45) As has already been described with respect to the prior art, that end side of the support pin 39 which lies opposite the journal 40 is configured as a recess 35, in which the associated ball 34 lies.

(46) Here, in order to receive the ball 34, the rotary lever 9 has a dome-like depression 37 which is lined by a plain bearing shell 38, it being possible for said plain bearing shell 38 to be configured as a composite plain bearing, with a carrier layer made from metal and a sliding layer made from plastic. As an alternative or in addition, the depression can also be covered by way of a plain bearing shell 38.

(47) By way of a stepped supporting face 42 which is formed between the support pin 39 and the journal 40, the bearing block 33 bears against a face of the brake caliper 1, which face is adapted, for example is machined.

(48) As has been mentioned, the connection between the bearing blocks 33 and the brake caliper 1 is configured in such a way that at least one bearing block 33 is configured in the sense of a floating bearing, with the option of compensating for manufacture-induced tolerances of the brake application device 8.

(49) In this way, a dimensional redundancy of the bearing of the rotary lever 9 is avoided, which dimensional redundancy would arise if the two bearing blocks 33 were held rigidly on the brake caliper 1, as a result of which increased wear and a reduction in the service life are reduced considerably.

(50) FIG. 9 depicts a sectioned side view of a part of a disc brake according to the invention. FIGS. 10 and 11 show different rear views of in each case the arrangement of the rotary lever 9 of the brake application device 8 and its mounting on the support pin 39 by way of the balls 34.

(51) FIG. 12 reproduces the rotary lever 9 with inset balls 34 on its own; the bearing blocks 33 can be seen as a detail.

(52) A comparable depiction can be seen in FIG. 13, it being possible here for a bearing block 33 to be seen on one side and the balls 34 without support in the support pin 39 on the other side.

(53) FIG. 14 depicts the detail which is shown in FIG. 9 in a sectioned plan view, whereas FIG. 15 shows a detail of the brake application device 8 of FIG. 14 in a likewise sectioned plan view, the illustration of the gear mechanism 24 and the brake caliper 1 being dispensed with here.

(54) FIG. 16 in turn shows a sectioned side view of the brake application device 8 in accordance with the sectional line XVI-XVI in FIG. 14.

LIST OF DESIGNATIONS

(55) 1 Brake caliper 2 Brake disc 3 Brake pad 4 Threaded spindle 5 Adjuster 6 Screw 7 Threaded sleeve 8 Brake application device 9 Rotary lever 10 Pressure piece 11 Closure plate 12 Screw 13 Bellows (gaiter) 14 Compression spring 15 Compression spring 16 Eccentric 17 Depression 18 Bearing shell 19 Channel 20 Anti-friction roller 21 Section 22 Bearing shell 23 End side 24 Gearwheel mechanism 25 Gearwheel 26 Gearwheel 27 Driver device 28 Plate 29 Screw 30 Spacer sleeve 31 Sliding ring 32 Attachment 33 Bearing block 34 Ball 35 Recess 36 Ball 37 Domed depression 38 Plain bearing shell 39 Support pin 40 Journal 41 Bore 42 Supporting face

(56) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.