HK1248789B - Disk brake for a utility vehicle - Google Patents

Description

Disc brakes for commercial vehicles

Technical Field

The invention relates to a disc brake for a commercial vehicle.

Background Art

DE 10 2008 036 765 A1 and DE 10 2009 018 223 A1 each disclose a disc brake in which a non-rotatable adjustment shaft of a brake plunger forms a nut part which is guided on a spindle rotatable relative thereto, the internal thread of the adjustment shaft and the external thread of the spindle forming a thread pair.

To compensate for wear-induced changes in the air gap (ie, the distance between the brake application-side brake lining and the vehicle-side brake disc), the spindle is rotated relative to a rotationally fixed adjustment shaft by means of an adjusting device provided in the brake caliper.

For this purpose, the adjusting device has a drive wheel which is connected in a rotationally fixed and axially fixed manner to a drive shaft of the adjusting device and which is operatively connected to an output wheel which is held in a rotationally fixed manner on the threaded spindle.

In this known disc brake, two parallel brake plungers spaced apart from one another are provided. For air gap compensation, the brake plungers can be driven to compensate for the air gap via a central adjustment device, i.e., an adjustment device arranged between the two brake plungers. A driven wheel is provided for each adjustment shaft, which is part of the gear transmission mechanism of the adjustment device.

DE102012012818 A1 relates to a similar disc brake, which, however, has only a centrally arranged brake plunger, the adjustment shaft of which is constructed as a threaded sleeve with an internal thread, which engages with a spindle rotatable relative to the threaded sleeve, and on the driven wheel of which in turn acts an axially fixed drive wheel of an adjustment device arranged to the side thereof.

In addition to the gear transmission known from the aforementioned prior art, other transmissions, such as traction transmissions, can also be used to transmit the rotation of the adjusting device to the brake plunger.

During braking, i.e., when the brake lever is actuated, the brake plunger, together with the driven wheel, which is held rotationally fixed on the spindle, moves axially toward the brake lining. As described above, the driven wheel is operatively connected to the drive wheel of the adjustment device, but the drive wheel is axially fixed. This means that the drive wheel and the driven wheel move axially relative to each other, which results in considerable mechanical loads that impair the service life of the brake system.

Summary of the Invention

The object of the present invention is to improve a disk brake of the generic type in such a way that the function is improved and the service life is prolonged.

The object is achieved by a disc brake for a vehicle, comprising:

a) Brake calipers straddling the brake disc;

b) a brake applying device arranged in the brake caliper, which is used to press the brake lining against the brake disc;

c) at least one brake plunger, said brake plunger being axially displaceable by means of a brake applying device;

d) an adjusting device positioned in the brake caliper, which is operatively connected to the brake plunger via a transmission mechanism so as to allow axial adjustment of the brake plunger to compensate for changes in the air gap caused by wear,

e) the transmission mechanism comprises a driving wheel (25) held on the adjusting device in a non-rotatable manner and a driven wheel held on the brake plunger in a non-rotatable manner,

In this case, a driven wheel connected to the brake plunger in a rotationally fixed manner and a drive wheel of the adjusting device corresponding to the driven wheel are arranged in an axially displaceable but rotationally fixed entrainment device.

For this purpose, the drive wheel of the adjusting device is mounted so as to be fixed in rotation but nevertheless axially displaceable, specifically axially displaceable both in the brake application direction, ie the braking direction, and also in the reset direction.

The previously troublesome mechanical loads can be avoided by the invention, in which a driver is provided, by means of which two operatively connected transmission wheels are coupled to one another in such a way that the braking-induced axial movement of the brake plunger is transmitted to the drive wheel of the adjusting device.

This, of course, increases the service life of the disk brake overall and thus significantly reduces the operating costs resulting from, on the one hand, the repair of the disk brake including the purchase of spare parts and, on the other hand, the downtime of the commercial vehicle during the repair work.

Furthermore, the present invention also improves the operational or functional reliability of the disk brake, since the adjustment device is now functionally reliable substantially throughout the entire service life of the brake lining, ie until it is replaced due to wear.

The entrainment device can be designed in various ways in terms of construction; what is important is that the cooperating drive wheels are connected to one another in such a way that they remain freely rotatable.

For this purpose, a coupling is provided which, according to a preferred embodiment of the invention, consists of two plates, preferably metal plates, arranged parallel and spaced apart from one another, between which a drive wheel, such as a gear wheel or similarly also a sprocket, is positioned.

At this, the two plates are connected to each other and are kept at a certain distance by suitable means, such as flanges, spacer sleeves or the like, which is designed to be substantially equal to the thickness of the transmission wheel. Of course, other designs of the coupling member may also be considered.

As described above, the present invention can be implemented both in a disc brake with only one brake plunger, in which case the brake plunger is arranged centrally and the adjustment device is positioned laterally, and in a disc brake with two brake plungers, in which case the adjustment device is arranged between the brake plungers.

The drive wheel rests against the two plates, preferably indirectly, ie with the involvement of a slip ring, on which the drive wheel is supported and which, corresponding to the drive wheel, is made of a material with a low coefficient of friction.

The slip ring may be embedded in a plate or in the transmission wheel itself, and has a circular ring shape so as to have a small contact area with the component rotatable relative to it.

Furthermore, the drive can be manufactured very cost-effectively, since the plate which essentially forms the drive is designed as a simple sheet metal stamping, into which a flange can be formed at the same time as a spacer, which projects into the intermediate space formed by the two plates arranged at a distance from one another and rests against one another in such a way that they can be connected to one another, for example, by welding.

Distance sleeves, also known as spacers, can also be produced simply and cost-effectively, in particular as pipe sections.

Furthermore, it is preferably provided according to the invention that the entrainment device is fastened to the brake plunger and/or the adjusting device.

Furthermore, it is preferably provided according to the invention that the entrainment device is held axially fixed on a receiving sleeve of the adjusting device, which carries the drive wheel and is rotatably held in the entrainment device.

Furthermore, it is preferably provided according to the invention that the entrainment device comprises two coupling parts which are arranged at a distance from one another and are connected to one another.

Furthermore, it is preferably provided according to the present invention that the coupling element is composed of plates arranged parallel to each other and spaced apart, forming an intermediate space for accommodating the drive wheel and the driven wheel. Furthermore, it is preferably provided according to the present invention that the plates are connected to each other by bolts, on which spacer sleeves are guided, and the end sides of the spacer sleeves are respectively supported on the inner surface of the plates. Furthermore, it is preferably provided according to the present invention that flanges connected to each other are provided in at least one of the plates. Furthermore, it is preferably provided according to the present invention that the plates are connected to each other by a pin, on which a spacer sleeve is guided and which is connected to at least one of the plates by arc welding. Furthermore, it is preferably provided according to the present invention that the drive wheel and/or driven wheel each rest on at least one slip ring. Furthermore, it is preferably provided according to the present invention that the slip ring is embedded in the plate. Furthermore, it is preferably provided according to the present invention that the friction pair formed by the slip ring and the drive wheel and/or driven wheel has a low friction coefficient. Furthermore, it is preferably provided according to the present invention that the vehicle is a commercial vehicle. Furthermore, it is preferably provided according to the present invention that flanges connected to each other are provided in the two plates.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present invention are described below with reference to the accompanying drawings.

FIG1 shows a disc brake according to the prior art in a partially cutaway top view;

FIG2 shows a detailed perspective view of the brake application device and the adjustment device;

FIG3 shows the brake application device according to FIG2 in a schematic sectional side view;

FIG4 also shows a detail of the brake application device according to FIG2 in a perspective view;

FIG5 shows a perspective view of a partial detail of a disc brake;

FIG. 6 shows another detail of the disk brake, also in a schematic sectional view.

DETAILED DESCRIPTION

1 shows a schematic diagram of a disk brake according to the prior art, comprising a brake caliper 1 designed as a sliding caliper, which bridges a brake disk 2 and in which two brake linings 3 are arranged, which press against the brake disk 2 during operation, ie during braking.

First, the brake application side brake lining 3 is pressed against the brake disk 2 by means of the brake application device 8 , and then the reaction side brake lining 3 is pressed against the brake disk 2 due to the reaction force, entrained by the moving brake caliper 1 .

The brake application device has a central brake plunger 4 which is pressed axially displaceably against the brake lining 3 on the brake application side via a brake lever 9 .

The brake plunger 4 comprises a rotatable threaded spindle 6 and a non-rotatably held threaded sleeve 7, the internal thread of which engages in the external thread of the threaded spindle 6. On the side facing the associated brake lining 3, a plate-shaped pressure piece 10 is fixed to the threaded sleeve 7, which bears against the brake lining 3 in the braking situation and is otherwise held in a form-fitting manner on the threaded sleeve to prevent rotation of the threaded sleeve 7.

The adjusting device 5 is connected to the threaded spindle 6 in order to compensate for the air gap, ie the distance between the brake lining 3 and the brake disk 2 , which changes due to wear.

To protect the receiving space of the brake caliper 1 accommodating the brake application device 8 and the adjustment device 5 , the mounting hole of the brake caliper 1 is closed on the side facing the brake disc 2 by a closing plate 11 , which is connected to the brake caliper 1 by screws 12 .

The brake plunger 4 passes through the closing plate 11 , while the adjusting device 5 is supported on the closing plate 11 in a loaded manner by a compression spring 14 .

The passage area of the brake plunger 4 is sealed by means of a bellows 13 which rests sealingly on the closure plate 11 on one side and on the pressure piece 10 or the brake plunger 4 on the other side.

The brake lever 9 is pivotably supported on the brake plunger 4 via a ball as an intermediate element, just as it is supported on the brake caliper 1 via a ball.

FIG2 shows a detail of a brake application device 8 and an adjacent adjustment device 5, which corresponds in its functional design to the prior art shown in FIG1. Specifically, a central brake plunger 4 and an adjacent adjustment device 5 are provided, by means of which a rotationally fixed drive wheel 25 of a gear train 24, designed as a gear, can be driven.

In order to transmit the rotational movement for air gap compensation, the drive wheel 25 meshes with a driven wheel 26 , which is also designed as a gear and is connected to the threaded spindle 6 in a rotationally fixed manner, so that when the driven wheel 26 and thus the threaded spindle 6 rotate, the threaded sleeve 7 guided on the threaded spindle is axially adjusted.

The arrangement of the driven wheel 26 can also be seen in FIGS. 3 and 4 .

In the example shown in FIG. 3 , the convex section 21 of the brake lever 9 is supported via a bearing shell 22 on a driven wheel 26 , for which purpose the driven wheel is in the form of a spur gear and has a closed bottom.

However, it is also conceivable for the convex section 21 of the brake lever 9 to rest against the facing end side of the threaded spindle 6 .

2 to 4 , it can be seen that the drive wheel 25 and the driven wheel 26 of the transmission 24 are positioned according to the invention in a carrier 27 which comprises two parallel plates 28 , 28 ′ arranged at a distance from one another as coupling elements.

The plates are in turn connected to one another by means of screws 29 , on which are guided spacer sleeves 30 which are supported with their ends on the mutually facing inner surfaces of the plates 28 , 28 ′, thereby forming an intermediate space for accommodating the transmission 24 .

5 and 6 each show further examples of how the intermediate space for accommodating the transmission mechanism 24 can be formed.

FIG. 5 shows mutually opposing flanges 15 which are pressed into opposing plates 28 , 28 ′ and which rest against each other in a pin-like manner with their mutually facing end faces and are, for example, welded together.

In FIG6 , a pin 18 is guided through a plate 28 , the pin resting on one side with its head on the outer side of the plate 28 and on the other side resting on the inner side of the plate 28 ′, where it forms a weld spot 23 , which is produced by arc welding with the plate 28 ′, by means of which the plates 28 , 28 ′ are connected to one another. According to the embodiment of FIG4 , the spacing for forming the intermediate space between the two plates 28 , 28 ′ is achieved by a spacer sleeve 30 , through which the pin 18 is guided.

When the brake lever 9 is pivoted to apply the brake, the brake plunger 4 is moved axially toward the brake lining 3 ( FIG. 1 ) via the eccentric 16, simultaneously driving the driven wheel 26. The drive wheel 25 of the adjustment device 5 is also driven by means of the driver 27, which is held on the adjustment device 5 in a rotationally fixed but axially displaceable manner.

Since the driving wheel 25 and the driven wheel 26 rotate relative to the plates 28, 28' during operation, a slip ring 31 is provided to reduce the frictional resistance between the driving wheel and the driven wheel 25, 26 and the plates 28, 28', as clearly visible in Figure 3. In this example, the slip ring is embedded in the plate 28 and protrudes into the resulting intermediate space with a small protrusion, so that the driving wheel 25 and the driven wheel 26 are held relative to the plate 28 without any gap.

After releasing the brake, the brake plunger 4 and thus the driven wheel 26 are reset by means of a compression spring 14 which is supported on one side on the closure cover 11 and on the other side on an associated plate 28 and which is guided on the brake plunger 4 .

As can be seen particularly clearly in FIG. 4 , the plate 28 ′ facing the brake lever 9 rests against the driven wheel 26 only over a partial region, but it surrounds the receiving sleeve 33 .

The drive wheel 25 is fixedly held on the receiving sleeve 33 not only in the axial direction but also in the circumferential direction and is connected to the adjusting device 5 in such a way that it can be moved axially but is simultaneously held against relative rotation. The receiving sleeve 33 and the drive wheel 25 can be constructed as one component or as two separate components.

The receiving sleeve 33 is inserted into a guide sleeve 32 ( FIG. 2 ) fixed to the closing plate 11 , which simultaneously forms a support for the adjusting device 5 and relative to which the receiving sleeve 33 is axially displaceable during axial adjustment of the brake plunger 4 .

1 , the brake application device 8 shown in FIGS. 2 and 3 has a brake lever 9 which is not supported on the brake plunger 4 via a bearing ball, nor on the brake caliper head via a bearing ball.

Instead, a groove 19 is formed in the brake lever 9 on the side opposite the eccentric 16, in which an anti-friction roller 20 is arranged, which is supported on a support point, which can be a bearing point, provided on the caliper head of the brake caliper 1. The anti-friction roller 20 preferably forms a pivot bearing for the brake lever 9, as can be seen particularly clearly in FIG.

A recess 17 is provided at the end of the brake lever 9 opposite the eccentric 16 , into which a tappet of a brake cylinder can engage, which tappet can be actuated, for example, pneumatically and/or electrically, in order to pivot the brake lever 9 in the braking situation.

Reference Signs List

1 brake caliper

2 brake discs

3 brake linings

4 brake plungers

5. Adjustment device

6 screws

7 Threaded sleeve

8 Brake application device

9 brake lever

10 Pressure piece

11 Closing plate

12 bolts

13 bellows

14 Compression spring

15 flange

16 eccentric wheel

17 recess

18 pins

19 grooves

20 Anti-friction roller

21 sections

22 bearing

23 solder joints

24 Transmission Mechanism

25 driving wheels

26 driven pulley

27 Driving device

28 boards

28' board

29 bolts

30 Spacer Sleeve

31 slip ring

32 guide sleeve

33 Receiving sleeve

Claims (13)

1. A disc brake for a vehicle, the disc brake comprising: a) Brake caliper (1) bridging the brake disc (2); b) A brake application device (8) provided in the brake caliper (1) for pressing the brake pads (3) against the brake disc (2); c) At least one brake plunger (4) which can be axially moved by means of a brake application device (8); d) An adjusting device (5) located in the brake caliper (1), which is operatively connected to the brake plunger (4) via a transmission mechanism (24) to allow axial adjustment of the brake plunger to compensate for changes in the air gap caused by wear. e) The transmission mechanism (24) includes a drive wheel (25) that is non-rotatably held on the adjusting device (5) and a driven wheel (26) that is non-rotatably held on the brake plunger (4). The characteristic feature is that the driven wheel (26) which is non-rotatably connected to the brake plunger (4) and the drive wheel (25) of the adjusting device (5) corresponding to the driven wheel are arranged in a drive device (27) which is axially movable but non-rotatably held. 2. The disc brake according to claim 1, wherein the driving device (27) is fixed on the brake plunger (4) and/or the adjusting device (5). 3. The disc brake according to claim 1 or 2, characterized in that the driving device (27) is axially fixedly held on the receiving sleeve (33) of the supporting drive wheel (25) of the adjusting device (5), the receiving sleeve being rotatably held in the driving device (27). 4. The disc brake according to claim 1 or 2, characterized in that the driving device (27) comprises two coupling members that are spaced apart from each other and connected to each other. 5. The disc brake according to claim 4, characterized in that the coupling member is composed of plates (28, 28') arranged parallel to each other and spaced apart, forming an intermediate space for accommodating the drive wheel (25) and the driven wheel (26). 6. The disc brake according to claim 5, characterized in that the plates (28, 28') are connected to each other by bolts (29), and spacer sleeves (30) are guided on the bolts (29), the end sides of the spacer sleeves being supported on the inner surfaces of the plates (28, 28'). 7. The disc brake according to claim 5, characterized in that at least one plate (28, 28') is provided with flanges (15) connected to each other. 8. The disc brake according to claim 5, characterized in that the plates (28, 28') are connected to each other by a pin (18) on which a spacer sleeve (30) is guided and the pin is connected to at least one plate (28, 28') by arc welding. 9. The disc brake according to claim 1 or 2, characterized in that the drive wheel (25) and/or driven wheel (26) respectively abut against at least one slip ring (31). 10. The disc brake according to claim 9, wherein the slip ring (31) is embedded in the plate (28, 28'). 11. The disc brake according to claim 9, characterized in that the friction pair formed by the slip ring (31) and the drive wheel (25) and/or the driven wheel (26) has a low coefficient of friction. 12. The disc brake according to claim 1 or 2, wherein the vehicle is a commercial vehicle. 13. The disc brake according to claim 5, characterized in that flanges (15) are provided in the two plates (28, 28') that are connected to each other.