Disk brake and drive element of and adjusting device of a disk brake
20170370434 · 2017-12-28
Inventors
Cpc classification
F16D2125/28
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2121/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D65/567
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D65/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2125/64
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2125/26
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2125/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D55/22
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D55/2255
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16D65/56
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D65/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A disk brake is proposed for a vehicle, preferably a commercial vehicle, having a brake caliper which engages over a brake disk and brake linings on both sides of the brake disk, a brake application device (5) which can be actuated by way of a force element, preferably a pneumatic force element, an adjusting device (20) for compensating for the brake lining and brake disk wear, which adjusting device (20) is arranged on an adjusting axis (L) which extends in the brake application direction, and is provided with a drive element (27) which can be rotated about the adjusting axis (L), and a brake lever (10) which is a constituent part of the brake application device (5) and is composed of a brake application shaft (11) which on one hand is supported in relation to the brake caliper and on the other hand in relation to a pressure piece (8) which operates against one of the brake linings, and a lever arm (12) which can be pivoted with the brake application shaft (11) and the pivoting center line of which extends at a right angle with respect to the brake application shaft (11), and which lever arm (12) is provided with a support (16) for the force element in the region of its outer end (12A), the brake lever (10) having a clearance (40) in an extension of the lever arm (12) to the inside, through which clearance (40) the adjusting axis (L) extends, a mechanism which couples the brake lever (10) to the drive element (27), and which is composed of a first mechanism element (31) on the brake lever (10) and a second mechanism element (32) on the drive element (27), which second mechanism element (32) interacts with said first mechanism element (31).
In order to provide as much installation space as possible for the brake application shaft, the first mechanism element (31) is arranged at the inner end (12B) of the lever arm (12) in the plane (E) which is defined by the pivoting movement (S) of the lever arm (12).
Claims
1. A disk brake for a vehicle, preferably a commercial vehicle, having a brake caliper which engages over a brake disk and brake linings on both sides of the brake disk, a brake application device (5) which can be actuated by way of a force element and preferably a pneumatic cylinder, an adjusting device (20) for compensating for the brake lining and brake disk wear, which adjusting device (20) is arranged on an adjusting axis (L) which extends in the brake application direction, and is provided with a drive element (27) which can be rotated about the adjusting axis (L), and a brake lever (10) which is a constituent part of the brake application device (5) and is composed of a brake application shaft (11) which is mounted in the brake caliper on a pivoting axis and is supported such that it can be moved rotationally against a pressure piece (8) which operates against the brake application-side brake lining, and a lever arm (12) which is connected to the brake application shaft (11) and the pivoting center line of which extends at a right angle with respect to the brake application shaft (11), and which lever arm (12) is provided with a support (16) for the force element in the region of its outer end (12A), the brake lever (10) having a clearance (40) in an extension of the lever arm (12) to the inside, through which clearance (40) the adjusting axis (L) extends, a mechanism which couples the brake lever (10) to the drive element (27), and which is composed of a first mechanism element (31) on the brake lever (10) and a second mechanism element (32) on the drive element (27), which second mechanism element (32) interacts with said first mechanism element (31), characterized in that the first mechanism element (31) is arranged at the inner end (12B) of the lever arm (12) in the plane (E) which is defined by the pivoting movement (S) of the lever arm (12), and in that one of the two mechanism elements is a slotted guide (31, 32) and the other mechanism element is an element which is guided along the slotted guide (31, 32).
2. The disk brake as claimed in claim 1, characterized in that the first mechanism element (31) is a single or double pin which is fastened in the brake lever (10).
3. The disk brake as claimed in claim 1, characterized in that the brake lever (10) is a forged component or a cast component, and in that the first mechanism element (31) is forged or cast onto it.
4. The disk brake as claimed in claim 1, characterized in that the slotted guide (31, 32) extends at least over part of its length obliquely with respect to the plane (E) which is defined by the pivoting movement (S) of the lever arm (12).
5. The disk brake as claimed in claim 4, characterized in that the slotted guide (31, 32) extends over its entire length obliquely with respect to the plane (E) which is defined by the pivoting movement (S) of the lever arm (12).
6. The disk brake as claimed in claim 4 or 5, characterized in that the angle (W), at which the slotted guide (31, 32) extends obliquely with respect to the plane (E) which is defined by the pivoting movement (S) of the lever arm (12), varies over the length of the slotted guide (31, 32).
7. The disk brake as claimed in claim 6, characterized in that the angle (W) becomes smaller as the pivoting movement (S) increases during the brake application.
8. The disk brake as claimed in one of claims 1 to 7, characterized in that the slotted guide (31, 32) describes an arc which is curved outward in relation to the adjusting axis (L) and the curved course of which corresponds at least over a part length to the path which is taken by the inner end (12B) of the lever arm (12) during its pivoting movement (S).
9. The disk brake as claimed in one of claims 1 to 8, characterized in that the drive element (27) is composed of the slotted guide (32), which is designed as a single or double arm, and a carrier (35), to which the slotted guide (32) is fastened, and in that the carrier (35) has a fastening region (36) for mounting the drive element (27) on the adjusting device fixedly so as to rotate with it.
10. The disk brake as claimed in claim 9, characterized in that the slotted guide (32) and the carrier (35) consist of the same material in one piece, preferably of plastic.
11. The disk brake as claimed in one of the preceding claims, characterized in that the first mechanism element (31) is arranged where the brake lever branches in a fork-shaped manner into a first limb (13A) which leads to a first section (11A) and a second limb (13B) which leads to a second section (11B) of the brake application shaft (11).
12. A drive element (27) of an adjusting device for compensating for the brake lining and brake disk wear of a disk brake, having a carrier (35), on which a fastening region (36) is configured for mounting the drive element (27) on the adjusting device fixedly so as to rotate with it, and a slotted guide (32) which is arranged on the carrier (35) in the shape of a simple or double arm and describes an arc which is curved outward in relation to the fastening region (36) of the carrier (35).
13. The drive element as claimed in claim 12, characterized in that the slotted guide (32) extends at least over part of its length obliquely with respect to the longitudinal axis of the adjusting device.
14. The drive element as claimed in claim 13, characterized in that the slotted guide (31, 32) extends over its entire length obliquely with respect to the longitudinal axis of the adjusting device.
15. The drive element as claimed in claim 13 or 14, characterized in that the angle (W), at which the slotted guide (32) extends obliquely with respect to the longitudinal axis of the adjusting device, varies over the length of the slotted guide (32).
16. The drive element as claimed in one of claims 12-15, characterized in that the slotted guide (32) and the carrier (35) consist of the same material in one piece, preferably of plastic.
Description
[0023] In the following text, the invention is described in greater detail using exemplary embodiments with reference to the drawings and the details which are illustrated therein. In the drawings:
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
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[0039]
[0040]
[0041] The drawings do not illustrate an entire disk brake, as installed, in particular, as a commercial vehicle brake which is actuated by compressed air, but rather only the brake application device 5 of the disk brake. With regard to further details of the disk brake including its brake caliper, the brake disk, the brake linings on both sides of the brake disk, reference is made, insofar as the customary design of a disk brake of this type is proposed, to disk brakes as described, for example, in DE 10 2008 037 774 B3 and in DE 43 07 018 A1.
[0042] The main constituent parts of the brake application device 5, the function of which is to boost, by way of lever action, braking forces which are produced by way of a force element, are a brake lever 10 which is mounted pivotably in a brake caliper of the disk brake, and a pressure piece 8 which operates against at least one of the brake linings of the disk brake, here in the shape of a crossmember which extends over the entire width of the brake lever 10.
[0043] The brake lever 10 is composed of a brake application shaft 11 which is divided into two sections, and a lever arm 12. The brake application shaft 11 is supported on its rear side from the inside against the brake caliper of the disk brake. Said support takes place via a pivot bearing, to which end two split bearings are arranged between the brake application shaft 11 and a corresponding face in the brake caliper. In the other direction, that is to say toward the brake lining and the brake disk, the brake application shaft 11 is supported pivotably via two further split bearings 17 against the pressure piece 8 which is of recess-shaped design in this region.
[0044] The brake application shaft 11 is configured as an eccentric. This is because the rear-side split bearings which are supported against the brake caliper have a rotational axis A2 which is arranged offset vertically in comparison with the rotational axis A1 of the split bearings 17 which are supported against the pressure piece 8. During a rotation of the brake application shaft 11 about the rotational axis A2 which defines the rotational movement with respect to the brake caliper, a forward movement of the pressure piece 8 therefore occurs in the direction of the brake disk of the disk brake, with the result that the brake is applied.
[0045] The lever arm 12, as a single-piece constituent part of the brake lever 10, serves to rotate the brake application shaft 11 by means of a boosting lever action. The center line of said lever arm 12 extends at a right angle with respect to the brake application shaft 11. Close to its outer end 12A, the lever arm 12 is provided with a support 16. The latter is preferably of spherical-like design and defines a supporting point, against which the force element of the disk brake operates. In the case of disk brakes which are actuated by compressed air, said force element is the tappet of a pneumatic brake cylinder.
[0046] The brake lever 10 is fork-shaped overall and branches, starting from the lever arm 12 which is arranged on the pivoting center line, into two limbs 13A, 13B, of which the one limb 13A is connected to the first section 11A of the brake application shaft 11, and the second limb 13B is connected to the second section 11B of the brake application shaft 11. In this way, the brake lever 10 has a clearance 40 to the inside in an extension of the lever arm 12. Said clearance 40 is delimited, inter alia, by way of the end faces which face one another of the sections 11A, 11B of the brake application shaft 11, and, toward the lever arm 12, by way of the inner end 12B of the lever arm 12.
[0047] The inner end 12B of the lever arm 12 is that location on the lever arm 12, at which the limbs 13A, 13B branch. Said location is situated between the rotational axis A2, about which the brake lever 10 pivots relative to the brake caliper, and the support 16. Said location is preferably situated at approximately one third of the distance between the rotational axis A2, about which the brake lever 10 pivots relative to the brake caliper, and the support 16.
[0048] The clearance 40 which is necessitated by the double-limb fork shape of the brake lever 10 affords space for an adjusting device 20. Constituent parts of the adjusting device 20 are, inter alia, a drive element 10, an output element which reduces the air play of the brake, and, in the movement path between the drive element and the output element, a one-way clutch and an overload element.
[0049] Said constituent parts of the adjusting device 20 are arranged on a common adjusting axis L. The adjusting axis L extends in the brake application direction and therefore perpendicularly with respect to the plane of the brake disk. The adjusting axis L extends through the clearance 40 of the brake lever 10. It is preferably arranged in such a way that it intersects one of the rotational or pivoting axes A1, A2 of the brake lever 10.
[0050] In order to derive the adjustment of the brake from the pivoting of the brake lever 10, there is an adjusting mechanism which couples the brake lever 10 to the drive element 27 of the adjusting device. The adjusting mechanism is composed of a first mechanism element 31 which is situated on the brake lever 10 and a second mechanism element 32 which interacts therewith and is situated on the adjusting device 20. The two elements 31, 32 preferably engage into one another virtually without play, in order thus to prevent irritations of the brake adjustment as a result of shocks or vibrations of the disk brake.
[0051] The first (that is to say, the lever-side) mechanism element 31 is arranged in the clearance 40 at the inner end 12B of the lever arm 12 and therefore where the two limbs 13A, 13B branch. In this way, the first mechanism element 31 is situated at a location in that plane E, within which the lever arm 12 carries out its pivoting movement S during the brake application of the brake. The adjusting axis L also lies in said plane E. At the same time, the first mechanism element 31 is situated at a location between the adjusting axis L and the support 16 for the force element, which support 16 is arranged at the other end 12A of the lever arm 12.
[0052] In the embodiment according to
[0053] The second (that is to say, the adjustment-side) element 32 of the adjusting mechanism is a slotted guide comprising two arms which run equidistantly and a slot 33 which is arranged in between. In the slot which can also be designed as a groove 33 in accordance with the outline illustrations of
[0054] In order that a rotation of the drive element 27 about the adjusting axis L occurs during the brake application movement S, the slotted guide 32 runs on a slotted guide section 32B and therefore at least over a part of the entire length of the slotted guide obliquely with respect to the adjusting axis L.
[0055] In order to derive the transmission of movement from the pivoting movement S of the lever arm 12 with particularly low friction, the slotted guide 32 describes an arc which is curved to the outside in relation to the adjusting axis L. The curvature of said arc follows the likewise curved movement of the pin 31 which is arranged at the inner end 12B of the lever arm 12 during the pivoting of the brake lever 10. In accordance with the outline illustration of
[0056] The drive element 27 (illustrated in
[0057] In accordance with the outline illustrations of
[0058] In accordance with the outline illustrations of
[0059] Although the lever-side first mechanism element 31 experiences a pivoting movement about the rotational axis A1 or A2 which extends transversely with respect to the axis L, said rotation does not produce a drive movement on the second mechanism element 32. Only the axial relative movement parallel to the axis L of the first mechanism element 31 brings about the rotary drive of the drive element 27.
[0060] This takes place by the first mechanism element 31 coming into contact in the one pivoting direction of the brake lever 10 with the slotted guide face which is ramp-like with respect to the axis L, and always pressing said slotted guide face away laterally. In the opposite pivoting direction, the first mechanism element 31 comes into contact with the slotted guide face which is ramp-like with respect to the axis L, and always presses said slotted guide face away laterally. Here, the slotted guide faces are spaced apart in an unvarying manner over their length, and said spacing is dimensioned in such a way that the pin 31 lies virtually without play between the slotted guide faces or encloses them from the outside.
[0061] This play-free insertion makes it possible to keep the mechanism elements 31 and 32 permanently in lateral engagement without appreciable hysteresis and at the same time to fixedly stipulate the idle stroke (without a transmission of movement) and the drive stroke (with a transmission of movement) via different curvature angles of the one mechanism element. The permanent lateral contact of the mechanism elements 31, 32 with respect to one another rules out an undesired influence of the adjustment by way of, for example, vibrations, since the mechanism elements 31 and 32 do not perform any uncontrolled lateral movements with respect to one another, for instance lateral to and fro knocking.
[0062]
[0063]
[0064] As long as the pin 31 is arranged perpendicularly with respect to the axis A1, A2, virtually only the axial relative movement enters into the drive movement. If, in contrast, the pin 31 lies at an angle of between 89° and 0° with respect to the axis A1, A2, that component of the axial relative movement which influences the rotary drive decreases as the actuating angle decreases, and that component of the pivoting movement which has an influence increases. If the pin 31 lies parallel to the axis A1, A2 (angle=0°), a rotary drive can no longer take place. In an angular range of from 45° to 135° with respect to the axis A1, A2, the utilization of the axial relative movement for a sufficient rotary drive is possible. The adjusting mechanism operates in an optimum manner in an angular range between 80° and 100°.
[0065] By virtue of the fact that the slotted guide runs on the slotted guide section 32A parallel to the movement of the engaging element 31, no transmission of movement takes place via said passive section of the slotted guide. If the movement along the slotted guide course is considered, said section 32A therefore leads to that limited play which is absolutely necessary within the context of the mechanical adjustment of the disk brake. The transmission of movement starts only when the passive slotted guide section 32A and therefore the limited play has been passed through, as soon as the other, obliquely arranged slotted guide section 32B is passed through.
[0066] It is important in said embodiment that all the components of the adjustment means which follow in the transmission of movement operate without play with respect to one another, in particular the components which are combined in the adjusting device 20. This is because the play which is absolutely necessary for the brake adjustment is realized structurally exclusively by way of the described two-phase course of the slotted guide 32.
[0067]
[0068] If the brake lever 10 is a cast component or a forged component, the groove 31 can be cast or forged thereon, with the result that no further component is required. This also otherwise applies to the embodiment with a lever-side pin 31 as a first mechanism element. Said pin 31 or an element in the shape of a pin of this type can also be cast or forged directly on the lever 10.
[0069] In
[0070] In order that a rotation of the drive element 27 about the adjusting axis L occurs during the brake application movement, the groove 31 runs over at least a part of its length, namely over a slotted guide section 31B, obliquely with respect to the adjusting axis L.
[0071] The angle, at which the groove 31 runs with respect to the adjusting axis L, can vary over the length of the groove. At the beginning of the brake application movement of the lever 10, that section of the groove which is situated in engagement with the pin 32, namely the slotted guide section 31A, has a rather straight course, with the result that the drive element first of all experiences no rotation or only a small rotation. Instead, a rotation of the drive element about the adjusting axis L takes place only in the further course of the movement of the brake lever 10 when the pin 32 runs through the groove or slotted guide section 31B.
[0072]
[0073]
[0074] In said embodiment, there is therefore no quasi passive slotted guide section. Rather, the transmission of movement starts immediately and directly. This function is appropriate when the components of the adjusting device 20 which follow with regard to the transmission of movement operate with a certain mutual play, in particular the components which are combined in the adjusting device. In this case, the play which is absolutely necessary for a mechanical brake adjustment is therefore not achieved by way of the course of the slotted guide, but rather by way of the existing system play in the individual components of the adjusting device 20.
[0075] In the embodiments according to
[0076] In accordance with the variant of
LIST OF DESIGNATIONS
[0077] 5 Brake application device [0078] 8 Pressure piece [0079] 10 Brake lever [0080] 11 Brake application shaft [0081] 12 Lever arm [0082] 12A Outer end of the lever arm [0083] 12B Inner end of the lever arm [0084] 13A Limb [0085] 13B Limb [0086] 16 Support [0087] 17 Split bearing [0088] 20 Adjusting device [0089] 27 Drive element [0090] 31 First mechanism element [0091] 31A Slotted guide section [0092] 31B Slotted guide section [0093] 32 Second mechanism element [0094] 32A Slotted guide section [0095] 32B Slotted guide section [0096] 33 Slot, groove [0097] 35 Carrier [0098] 36 Fastening region [0099] 39 Inner edge [0100] 40 Clearance [0101] A1 Rotational axis [0102] A2 Rotational axis [0103] E Plane of the pivoting movement [0104] L Adjusting axis [0105] S Pivoting movement of the brake lever [0106] W Angle