Brake System

Abstract

The present invention relates to a brake system comprising an actuating part and a brake part, the actuating part having a pressure chamber and a restoring section, the pressure chamber and the restoring section being separated from one another in a fluid-tight manner by way of a piston, it being possible for the piston to be fixed on an engagement element in such a way that a movement of the piston brings about a movement of the engagement element, the engagement element protruding into the brake part and having, in the brake part, a force section which is designed to transmit a force to a brake means, the brake part and the predominant part of the actuating part being arranged in a housing.

Claims

1.-14. (canceled)

15. A brake system, comprising: an actuating part; and a brake part; wherein the actuating part has a pressure chamber and a restoring section, the pressure chamber and the restoring section being separated from one another in a fluid-tight manner by a piston, wherein the piston is configured to be fixed on an engagement element such that a movement of the piston brings about a movement of the engagement element, the engagement element protruding into the brake part and having, in the brake part, a force section configured to transmit a force to a brake structure, the brake part and the restoring section and at least half of the pressure chamber of the actuating part being arranged in a one-piece housing, the housing being configured as an expansion wedge unit in the region of the brake part.

16. The brake system as claimed in claim 15, the engagement element configured to move along an actuating axis by a maximum actuating travel, the maximum actuating travel being in a ratio of from 0.05 to 0.6 to the overall extent of the brake system along the actuating axis.

17. The brake system of claim 16, wherein the ratio is from 0.06 to 0.3.

18. The brake system of claim 17, wherein the ratio is from 0.075 to 0.13.

19. The brake system as claimed in claim 15, wherein the actuating part is configured for a maximum operating pressure in the pressure chamber of at least 15 bar.

20. The brake system as claimed in claim 19, wherein the maximum operating pressure is at least 17 bar.

21. The brake system as claimed claim 15, wherein the housing comprises a cylindrical configuration having a mean diameter, the housing having a minimum wall thickness in the region of the pressure chamber, the minimum wall thickness being in a ratio of from 0.01 to 0.2 to the mean diameter.

22. The brake system as claimed in claim 21, wherein the ratio of the minimum wall thickness to the mean diameter is from 0.03 to 0.1.

23. The brake system as claimed in claim 22, wherein the ratio of the minimum wall thickness to the mean diameter is from 0.06 to 0.1.

24. The brake system as claimed in claim 15, wherein the engagement element and the piston are arranged completely within the housing.

25. The brake system as claimed in claim 15, wherein the housing includes a fluid nozzle which is configured on an outer side of the housing for the connection of a pressure line and opens on an inner side of the housing into the pressure chamber.

26. The brake system as claimed in claim 15, wherein the housing includes a flange section which is configured to fix the housing on a chassis element of a commercial vehicle.

27. The brake system as claimed in claim 15, wherein a first restoring element is arranged in the restoring section, the first restoring element configured to exert a force on the piston along an actuating axis in the direction of the pressure chamber.

28. The brake system as claimed in claim 27, wherein the first restoring element is prestressed in every operating state of the brake system.

29. The brake system as claimed in claim 27, wherein the housing includes a supporting section against which the first restoring element is supported along the actuating axis and/or which secures the engagement element against movement transversely with respect to the actuating axis.

30. The brake system as claimed in claim 15, comprising a parking brake unit configured to adjoin the pressure chamber, the parking brake unit having a second restoring element and a parking brake accumulator which are separated from one another in a fluid-tight manner by way of a parking brake piston, the parking brake piston configured to transmit a force indirectly or directly to the engagement element.

31. The brake system as claimed in claim 30, wherein the parking brake unit includes a parking brake housing configured to be connected in a fluid-tight manner to the housing.

32. The brake system as claimed in claim 30, wherein the pressure chamber is delimited by a wall of the parking brake housing.

33. The brake system as claimed in claim 30, wherein the parking brake accumulator is delimited by a wall of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages and features of the present invention result from the following description with reference to the appended figures. It goes without saying here that individual features which are shown in only one of the embodiments can also be used in other embodiments of the brake system, as long as this has not been ruled out explicitly or is prohibited on account of the design of the brake system. In the drawing:

[0021] FIG. 1 shows a sectional view of a first preferred embodiment of the brake system according to the invention;

[0022] FIG. 2 shows a sectional view of a second embodiment of the brake system according to the invention; and

[0023] FIG. 3 shows a sectional view of the embodiment from FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] FIG. 1 diagrammatically shows a sectional view of a preferred brake system. Here, the brake system has an actuating part 2 and a brake part 4, both the actuating part 2 and the brake part 4 preferably being arranged completely within a housing 8. The actuating part 2 advantageously comprises a pressure chamber 22 and a restoring section 24 which are separated from one another in a fluid-tight manner by way of a piston 6. A first restoring element 12 is arranged in the restoring section 24, which first restoring element 12 exerts a force on the piston 6, in order to move the latter in the direction of the pressure chamber 22. The piston 6 is advantageously connected fixedly to an engagement element 42, with the result that a movement of the piston 6 along the actuating axis B always leads to a movement of the engagement element 42 together with the piston 6. Here, the piston 6 is particularly preferably configured in one piece with the engagement element 42. On its region which protrudes into the brake part 4, the engagement element 42 has a force section 44. Here, the force section 44 is preferably a wedge geometry which is designed for actuating the expansion wedge unit of an expansion wedge drum brake. Between the actuating part 2 and the brake part 4, the housing 8 advantageously has a supporting section 86 which firstly serves to support the first restoring element 12 and, as an alternative or in addition, preferably also prevents a movement of the engagement element 42 transversely with respect to the actuating axis B. Furthermore, the housing 8 preferably has a flange section 84 which, as shown diagrammatically in the figure, is designed for fixing on the indicated chassis of a commercial vehicle.

[0025] It is particularly preferred here that the flange section 84 is configured in one piece with the housing 8, in order for it to be possible particularly preferably to withstand high forces and in order to simplify the assembly of the brake system. Furthermore, the housing 8 advantageously has a fluid nozzle 82 which is provided for connecting a pressure line to the housing 8 and introducing a fluid, such as compressed air, into the pressure chamber 22. It is not shown in the figure that a cover element 14 can preferably be attached to the housing 8 on the right-hand side of the pressure chamber 22, which cover element 14 replaces the right-hand wall of the pressure chamber 22 which is shown only diagrammatically in the figure, and therefore ensures the delimiting of the pressure chamber 22 on the side which faces away from the piston 6. Furthermore, the figure shows the minimum wall thickness w of the housing. Here, the minimum wall thickness w is particularly preferably measured in the region of the actuating part 2; in particular, the minimum wall thickness w is preferably provided in the region of the pressure chamber 22. Furthermore, the mean diameter D of the housing is shown, which mean diameter D is preferably measured in each case in the center of the housing wall in the case of a preferably cylindrically configured housing 8.

[0026] FIG. 2 shows a further preferred embodiment of the brake system according to the invention, a parking brake unit 3 also being provided in addition to the brake part 4 and the actuating part 2, which parking brake unit 3 adjoins the pressure chamber 22. Here, in the preferred embodiment which is shown in FIG. 2, a cover element 14 is provided which is fixed to the housing 8 with a positively locking connection. Here, the cover element 14 preferably forms a part of the housing 8. Furthermore, the cover element 14 preferably has a fluid nozzle 82 here for the supply of pressure fluid, such as compressed air, into the pressure chamber 22. Furthermore, a feed stub (not shown) for feeding compressed air into the parking brake accumulator 36 is also preferably provided on the housing. Here, the brake part 4 and the actuating part 2 of the embodiment which is shown in FIG. 2 have substantially the same features as in the embodiment which is shown in FIG. 1. The parking brake unit 3 preferably comprises a parking brake piston 32 which can be moved along the actuating axis B within a parking brake housing 38, and a region, in which a second restoring element 34 is arranged and separates the parking brake accumulator 36 from one another in a fluid-tight manner. Moreover, the parking brake piston 32 has a parking brake means 33 which is designed to transmit a force which is applied by the second restoring element 34 to the piston 6. Here, FIG. 2 shows an operating state of the brake system, in which the parking brake element 33 does not transmit any force to the piston 6. The reason for this is that a fluid is introduced in the parking brake accumulator 36 at a pressure which overcomes the restoring force of the second restoring element 34 and therefore ensures that the parking brake piston 32 is moved to the right in the figure and therefore the parking brake element 33 also moves away from the piston 6 and does not transmit any force to the latter. Furthermore, the figure shows the overall length L of the brake system which is particularly preferably very low within the context of the present invention. Here, in the normal operation of the brake system, the actuating element 22 covers a maximum actuating travel v which is in a preferred ratio of from 0.05 to 0.6 to the overall extent L of the brake system along the actuating axis B. This dimension is an expression for the particularly preferred, compact overall design of the brake system. Furthermore, FIG. 2 shows a preferred pivoting angle , about which, pivoted relative to the horizontal, the actuating axis B of the brake system preferably runs. As a result of the compact overall design of the brake system and a resulting low risk of coming into contact with further components of the commercial vehicle chassis, the pivoting angle can be kept as low as possible. It is preferred here that the pivoting angle lies in the range from 5 to 12, preferably from 0 to 10 relative to the horizontal. Furthermore, preferably and in the case of a particularly preferred compact overall design, as shown in FIG. 2, the pivoting angle can lie in the range from 5 to 10. The maximum actuating travel v advantageously lies in a ratio of from 0.28 to 0.8, preferably of from 0.4 to 0.7 and particularly preferably of approximately 0.6 to the extent k of the actuating part 2 along the actuating axis B.

[0027] FIG. 3 shows the embodiment from FIG. 2, a conventional brake system being shown using dashed lines. Within the context of the present invention, a solution has been found, by way of which the installation space requirement of a brake system can be reduced drastically, the requirements on the brake system, in particular with regard to the force to be applied, and also with regard to the actuating travel v remaining the same. FIG. 3 illustrates here how pronounced the installation space saving is that results by way of a brake system according to the invention. Here, the overall extent L of the preferred embodiment of the brake system according to the invention is approximately one third lower than the overall length X of a conventional brake system. In addition, partially as a consequence of the low overall extent L, the brake system according to the invention can be arranged pivoted by a smaller pivoting angle between the axial direction of the chassis and the actuating axis B than the conventional brake system. As a result, the maximum extent of the brake system transversely with respect to the axial direction of the chassis is also reduced.

LIST OF DESIGNATIONS

[0028] 2Actuating part [0029] 3Parking brake part [0030] 4Brake part [0031] 6Piston [0032] 8Housing [0033] 12First restoring element [0034] 14Cover element [0035] 22Pressure chamber [0036] 24Restoring section [0037] 32Parking brake piston [0038] 33Parking brake means [0039] 34Second restoring element [0040] 36Parking brake accumulator [0041] 38Parking brake housing [0042] 42Engagement element [0043] 44Force section [0044] 82Fluid nozzle [0045] 84Flange section [0046] 86Supporting section [0047] Angle [0048] BActuating axis [0049] DMean diameter [0050] kExtent, actuating part [0051] LOverall extent [0052] vActuating travel [0053] wWall thickness [0054] XOverall length