RADIAL DISC BRAKE FOR A COMMERCIAL VEHICLE

Description

[0001] The invention relates to a radial disc brake according to the preamble of claim 1.

[0002] The application device of such a radial disc brake usually has two brake pistons that are held parallel and spaced apart from each other in a bridge so that they can be adjusted axially.

[0003] The brake application system also includes a brake lever that can be pivoted pneumatically or electromechanically and has at least one eccentric section for engagement with the bridge. The brake lever rests on the brake caliper. The brake lever arm is housed in a lever dome, which is screwed as a separate part to a caliper housing.

[0004] The brake pistons are designed as threaded spindles with an external thread that engages with the internal thread of a threaded hole in the bridge.

[0005] To compensate for a wear-related change in the distance known as the air gap between the associated brake pad and the brake disc, an adjustment device is provided with which the brake pistons are adjusted axially by turning them.

[0006] In order to achieve a uniform rotation of the two brake pistons, the adjustment device has a synchronizing device which ensures a uniform feed movement of both brake pistons, thus avoiding uneven wear of the brake pads.

[0007] In the well-known radial disc brake, the synchronization device is designed as a traction drive, primarily in the form of a chain drive, with the two strands, which are deflected by sprockets of the brake pistons, running essentially linearly. The traction drive can consist of a roller-link chain, but other traction devices, such as toothed belts, are also conceivable.

[0008] Due to its design, the lever is guided around the chain drive, which requires the brake caliper to be constructed in multiple parts. The lever dome, which houses the lever arm of the brake lever, is connected to the caliper housing as a separate part, usually made of cast iron, like the brake caliper as a whole. Examples of radial disc brakes are known from EP 28 95760 A1 and DE 102015115856A1.

[0009] The disadvantage here is that, in addition to the use of a large number of screws for connection, sealing measures are also required to protect the interior of the brake caliper.

[0010] Process variations, such as those that occur during the assembly of the disc brake, particularly when attaching the lever dome to the caliper housing, are disadvantageous, as is the relatively high weight of the brake caliper resulting from its design, which contradicts the constant demands for weight minimization.

[0011] The invention is based on the object of further developing a radial disc brake of the generic type in such a way that it can be manufactured more quickly and thus more cost-effectively using simple structural means and that its operational reliability is improved.

[0012] This object is achieved by a radial disc brake having the features of claim 1.

[0013] According to the invention, by guiding the strands outside the lever dome, into which the lever arm of the brake lever projects, it is possible to form the lever dome and the caliper housing as a single piece as a cast part.

[0014] This significantly simplifies the assembly work, i.e. the assembly of the disc brake, since a separate lever dome no longer needs to be connected to the caliper housing.

[0015] The machining of the parts forming the brake calliper, namely the calliper housing and the lever dome, is also simplified and thus more cost-effective, with this particularly including the omission of threaded holes in the calliper housing in order to connect the lever dome to the calliper housing, as in the prior art.

[0016] Assembly is also simplified because a seal no longer needs to be provided and installed, as is necessary with a multi-part brake caliper.

[0017] Furthermore, the invention reduces the weight of the disc brake, especially the brake caliper, thus significantly meeting the demands for weight optimization. Since disc brakes are widely used in commercial vehicles, especially multi-axle ones, weight reduction is particularly important, as it also reduces fuel consumption.

[0018] As has been shown, the brake piston synchronization and consequently the braking performance is improved.

[0019] Since the traction mechanism according to the invention is arranged outside the lever dome, adjustment of the chain play is also possible more easily than was previously the case.

[0020] In one embodiment of the invention, the strands are guided via deflection bolts embedded in a flange surface of the brake calliper, whereby a chain play can be adjusted as required by adding or removing spacer sleeves on a deflection bolt or by turning at least one arranged eccentric

[0021] Preferably, the strands are guided in an imaginary approximately U- or trapezoidal path around the lever dome, with the eccentric bearing on the strand outer to the lever dome, while the inner strand bears on the spacer sleeves.

[0022] According to a further idea of the invention, guideways arranged in a U-shape around the lever dome are provided to guide the strands, on which the strands are supported.

[0023] These guideways are preferably formed from sheet metal, with an inner guideway being firmly connected to the brake calliper, while the outer guideway is adjustably attached to the brake calliper in such a way that chain play can be adjusted by moving the guideway in the vertical direction.

[0024] The guideways are secured to the brake caliper by a screw connection. Alternatively, or in addition, the guideways can also be held to the brake caliper by a positive fit.

[0025] In contrast to the aforementioned variant, in another embodiment of the invention the guidance of the strands is achieved by a support plate fastened to the brake calliper, which has a support collar on which the inner strand is supported, i.e. on which the inner strand is guided.

[0026] The outer strand, on the other hand, is guided by two opposing guide levers, at least one of which can be pivoted like a tensioning lever to adjust chain slack. For this purpose, the guide lever is mounted on a mounting bolt on one side and pivoted along a slotted hole through which a screw passes, allowing the guide lever to be fixed in the desired position.

[0027] To protect the traction drive, a cover plate is provided that covers the traction drive and is connected to the flange surface of the brake caliper by rivets. To adjust the traction drive or the strands, simply remove the cover plate, allowing free access to the traction drive.

[0028] Further advantageous embodiments of the invention are characterized in the subclaims.

[0029] Embodiments of the invention are described below with reference to the accompanying drawings.

[0030] They show: Fig. 1 and 2 a disc brake according to the prior art, each in different mounting positions in a perspective view Fig. 3 and 4 a disc brake according to the invention, also shown diagrammatically in different mounting positions Fig. 5 and 6 each a further embodiment of a disc brake according to the invention in a perspective view.

[0031] In the Fig. 1 a brake calliper 1 of a disc brake for a commercial vehicle according to the prior art is shown, which has a calliper housing 2 and a lever dome 3 fastened thereto by means of n 4. While the Fig. 1 The brake calliper 1 in its completed form is shown in the Fig. 2 the saddle housing 2 without the attached lever dome 3 can be seen.

[0032] It shows a traction drive 7, which in the example consists of a roller-link chain with two linearly guided strands 8 that run parallel to each other and engage with sprockets 5 of an adjustment device. The sprockets 5 are connected to brake pistons (not shown), by means of which a brake pad (also not shown) can be pressed against a brake disc.

[0033] The traction mechanism 7 is arranged on the outside of the caliper housing 2 and positioned below the lever arm 6 of a brake lever. In a completed disc brake, as is the case with the Figure 1 reproduces, the lever dome 3 covers the traction drive 7, with the lever arm 6 protruding into the lever dome 3.

[0034] Further in the Figure 2 Threaded holes 9 can be seen which are made in the saddle housing 2 and into which the n 4 for fastening the lever dome 3 to the saddle housing 2 are screwed.

[0035] In the Figure 3a disc brake according to the invention is shown, in which the traction mechanism drive 7 is guided outside the lever dome 3 formed integrally with the caliper housing 2, wherein the essentially parallel course of the two strands 8 is approximately U-shaped or trapezoidal.

[0036] To guide the strands 8, deflection pins 10 are arranged on a flange surface 18 of the caliper housing 2. A horizontal path of the strands 8 runs on the upper horizontal plane associated with a support surface 16 of the lever dome 3 for a pneumatic cylinder. The support surface 16 is also on the same side of the brake caliper as a mounting opening 13 of the caliper housing 2.

[0037] How to continue in the Figure 3As can be seen, some of the deflection bolts 10 are provided with spacer sleeves 17, by means of which a chain play can be adjusted if necessary, these spacer sleeves 17 being arranged on the deflection bolts 10, against which the lower run 8 facing the lever dome 3 rests.

[0038] Additionally or alternatively, the upper strand 8 is guided by a pivoting eccentric 11, which, depending on the adjustment, can also be used to adjust the chain play. The eccentric 11 can also serve to deflect the adjacent strand 8. Instead of the eccentric 11, a deflection pin 10 with a spacer sleeve 17 attached can also be provided.

[0039] In the Figure 4 the disc brake is shown completed in that the traction mechanism 7 is covered by a cover plate 14, this cover plate 14 being fixed by means of screws 15, which are inserted into threaded holes 12 ( Figure 3) of the flange surface 18. Preferably, the contour of the cover plate 14 corresponds to that of the flange surface 18.

[0040] A further embodiment of the disc brake according to the invention is shown in Figure 5 shown. For steering the strands 8 of the traction drive 7, an outer guide track 19 and an inner guide track 20 are provided as separate parts. These are bow-shaped and against each of which a strand 8 rests, specifically on the side of the respective guide track 19, 20 facing away from the support surface 16.

[0041] The inner guide track 20 closer to the lever dome 3 is firmly connected to the brake calliper 1 by screws, in which screws 23 are screwed into the flange surface 18.

[0042] The outer guide track 19 is also connected to the flange surface 18, but in such a way that a certain amount of pivoting is possible if necessary to adjust the chain tension. For this purpose, a fastening screw 21 is guided in a slotted hole 22 in the outer guide track 19, allowing the guide track 19 to move vertically. After appropriate adjustment, the outer guide track 19 can be secured by tightening the fastening screw 21.

[0043] The guideways 19, 20 can be designed as sheet metal parts, which form a support surface for the strands 8 on the outside in a bow-like, ie U-shaped course.

[0044] The Figure 6 shows a further embodiment of the invention, in which a carrier plate 24 is connected to the brake calliper 1 to guide the traction drive 7, for which purpose fastening bolts 27 and fastening screws 21 are provided.

[0045] The inner strand 8, relative to the lever dome 3, is guided on a molded support collar 28 that extends in a U-shape. The outer strand 8, on the other hand, rests on guide levers 25, at least one of which is pivotable about the fastening bolt 27, with which the guide lever 25 and thus the carrier plate 24 are attached to the brake caliper 1.

[0046] By pivoting the guide lever 25, the outer strand 8 can be tensioned as required, for which purpose the fastening screw 21 is guided in a slotted hole 26 provided in the guide lever 25. Just as in the Figure 5 In the example shown, the guide lever 25 is fixed by tightening the fastening screw 21 after tensioning the outer run 8.

[0047] The shaping of the carrier plate 24 is also carried out by forming into a bow-like U-shaped configuration. LIST OF REFERENCE SYMBOLS

[0048] 1 Brake caliper 2 Caliper housing 3 Lever dome 4 Screw 5 Sprocket 6 Lever arm 7 Traction drive 8 Strand 9 Threaded hole 10 Deflection pin 11 Eccentric 12 Threaded hole 13 Mounting opening 14 Cover plate 15 Screw 16 Support surface 17 Spacer sleeve 18 Flange surface 19 Guide track 20 Guide track 21 Fastening screw 22 Slotted hole 23 Screw 24 Support plate 25 Guide lever 26 Slotted hole 27 Fastening bolt 28 Support collar

Claims

1. Radial disc brake for a utility vehicle having - a tensioning device positioned in a receiving space of a brake caliper (1) with a caliper housing (2) and a lever dome (3) arranged thereon, comprising - a pivotable brake lever, which is provided with at least one eccentric section and an adjoining lever arm (6) which extends approximately parallel to the axis of rotation of the brake disc and projects into the lever dome (3), - two brake plungers mounted in an axially adjustable manner in a bridge and bearing against a brake pad during braking, - an adjustment device for compensating a change in air play caused by wear, - a synchronizing device which is functionally connected to the brake plungers and has a traction mechanism drive (7), characterized in that the traction mechanism drive (7) is arranged outside the lever dome (3), wherein the strands (8) of the traction mechanism drive (7) are guided around a partial region of the lever dome (3).

2. Brake disc according to claim 1, characterized in that the strands (8) bear against deflection bolts (10).

3. Disc brake according to claim 1 or 2, characterized in that the strands (8) extend along an imaginary U-shaped or trapezoidal path.

4. Disc brake according to any one of the preceding claims, characterized in that at least some of the deflection bolts (10) are provided with spacer sleeves (17) for adjusting a chain play.

5. Disc brake according to any one of the preceding claims, characterized in that the spacer sleeve (17) is arranged on the strand (8) facing the lever dome (3).

6. Disc brake according to any one of the preceding claims, characterized in that at least one pivotable eccentric (11) is provided for adjusting a chain play.

7. Disc brake according to any one of the preceding claims, characterized in that the eccentric (11) is arranged on a deflection bolt.

8. Disc brake according to any one of the preceding claims, characterized in that the eccentric (11) bears against the strand (8) facing away from the lever dome (3).

9. Disc brake according to any one of the preceding claims, characterized in that the deflection bolts (10) are secured to a flange surface (18) of the caliper housing (2).

10. Disc brake according to any one of the preceding claims, characterized in that the traction mechanism drive (7) is covered by a cover plate (14), which is connected to the flange surface (18).

11. Disc brake according to any one of the preceding claims, characterized in that the contour of the cover plate (14) corresponds to the contour of the flange surface (18).

12. Disc brake according to any one of the preceding claims, characterized in that the strands (8) of the traction mechanism drive (7) are each guided over a guide track (19, 20), which is bow-shaped and are connected to the brake caliper (1).

13. Disc brake according to any one of the preceding claims, characterized in that an outer guide track (19) is secured pivotably to the flange surface (18), wherein a fastening screw (21) is held in an elongated hole (22) of the outer guide track (19).

14. Disc brake according to any one of the preceding claims, characterized in that the guide tracks (19, 20) have a contact surface on the outer side for the strands (8).

15. Disc brake according to any one of the preceding claims, characterized in that a carrier plate (24) is secured to the flange surface (18), wherein guide levers (25) are arranged on the carrier plate (24) for guiding the outer strand (8) against which the outer strand (8) bears.

16. Disc brake according to any one of the preceding claims, characterized in that a support collar (28) is arranged on the carrier plate (24) for guiding the inner strand (8).

17. Disc brake according to any one of the preceding claims, characterized in that at least one of the guide levers (25) is pivotably attached to the carrier plate (24).

18. Disc brake according to any one of the preceding claims, characterized in that the pivotable guide lever (25) has an elongated hole (26), through which a fastening screw (21) is guided.