WO2016023697A1

WO2016023697A1 - Brake application device for a disc brake actuated by a rotary lever

Info

Publication number: WO2016023697A1
Application number: PCT/EP2015/066096
Authority: WO
Inventors: Johann Iraschko
Original assignee: Knorr-Bremse Systeme für Nutzfahrzeuge GmbH
Priority date: 2014-08-13
Filing date: 2015-07-15
Publication date: 2016-02-18
Also published as: DE102014111547B4; DE102014111547A1

Abstract

A disc brake having a brake calliper and a brake application device (1) which has at least the following features: a) an inner rotary lever (5) with a lever axis (9a), a drive operative lever arm (30) and an output operative lever arm (31) of the rotary lever (5) forming an offset angle (γ) in the lever axis (9a); b) at least one rolling body tensioning unit (22) which has a spindle axis (12) and at least one tensioning piston which can be moved perpendicularly with respect to the brake disc, and which brake application device (1) is designed to overcome the work stroke or to set the application-side application piston with the brake lining against the brake disc as a consequence of pivoting of the rotary lever (5) during braking operations; c) wherein a drive connection between the rotary lever (5) and the at least one rolling body tensioning unit (22) is configured as a coupler mechanism (26). The offset angle (γ) lies in a range from 60° to 80° if the disc brake is configured as an axial brake, or the offset angle (γ) lies in a range from 150° to 170° if the disc brake is configured as a radial brake.

Description

Clamping device for a lever-operated disc brake

The invention relates to an application device of a rotary lever-actuated disc brake, in particular a disc brake which can be actuated by means of a piston rod of a pneumatically or electromotively operated brake cylinder, according to the preamble of claim 1.

Pneumatically actuated disc brakes usually have designed as a sliding caliper, swivel saddle or fixed caliper caliper, in which a brake application device is arranged, which serves to bring brake pads on both sides of a brake disc and the brake disc with each other in operative connection to achieve a braking effect by friction.

Pneumatically operated disc brakes are now standard equipment for heavy commercial vehicles. Such disc brakes need to generate the required application force a mechanical translation, since the force of the pneumatically actuated brake cylinder is limited because of the pressure level (currently about 10 bar) and the limited size of the brake cylinder. In the currently known pneumatically actuated disc brakes are ratios between 10: 1 and 20: 1.

Such Zuspannmechanismen or devices have now established themselves in various designs on the market. The power transmission is represented by a lever with two different Hebelarmlängen. In this case, the brake cylinder force acts on the long lever arm and thus generates on the lever ratio on the short lever arm, a high force, which is required for pressing the brake pads to the brake disc. For better distribution, the application of the application force in the brake pad is often done via two so-called plungers, which in turn are coupled via threaded or Zuspannstempel (with a threaded spindle and a threaded sleeve or traverse) with the translation mechanism. But there are also systems that are designed with only one pressure piece and a threaded temple.

In addition to the above-mentioned lever system, a ramp mechanism or a threaded mechanism for power transmission can also be used.

In WO 2013/143962 A1 describes some concepts. A feature of these concepts is a so-called ball ramp unit, which is driven by means of an operating lever integrated in the brake. Upon rotation or pivoting of the actuating lever and transmission of movement via a coupling element, such as bevel gear segments, ball, flattened ball, coupling rod, etc., a ramp drive pulley of the ball ramp unit is set in a pivoting movement. The ball ramp unit consists of two ramp discs, which are arranged with the respective ramp disc in opposite directions, and between which there are balls to reduce friction.

This is important for a meterability of the brake. This property is expressed by the amount of so-called hysteresis. The term hysteresis is here understood to mean a difference in the application force during pressure build-up and pressure reduction.

The hysteresis is in addition to the rolling resistance of the Rampenkugeln, Lagerwälzkörper also sliding movements of the cylinder plunger in a lever pan, the lever pivot bearing and the rolling and sliding behavior of Bewegungsübertragungs- elements influenced by the operating lever on the ball ramp unit.

Therefore, the object of the invention is to provide an improved application device with an improved hysteresis and at the same time with a simple structural design.

The invention solves this problem by the subject matter of claim 1.

Accordingly, a disc brake according to the invention, in particular a disc brake operable by means of a piston rod of a pneumatically or electromotively operated brake cylinder, a brake caliper, which preferably frame-like a peripheral region of a brake disc, on which both sides at least one brake pad is disposed overlaps, the caliper on a supply side the brake disc in an opening receives a brake application device which has at least the following features: a) an inner, ie arranged in the interior of the caliper pivot lever with a preferably aligned parallel to the brake lever lever axis, wherein a Antriebswirkhebelarm and a Abtriebswirkhebelarm the rotary lever in the lever axis a Form offset angles; b) at least one Wälzkörperzuspanneinheit having a spindle axis and at least one movable perpendicular to the brake disk Zuspannkolben, and for overcoming the working stroke or for applying the zuspann- c) wherein a drive connection between the rotary lever and the at least one Wälzkörperzuspanneinheit as a Coupling mechanism is formed with at least one rounded coupling element. The offset angle is less than 90 ° and is in a range of 60 ° to 80 ° when the disc brake is formed as an axial brake with an introduction of force in the Antriebswirkhebelarm the rotary lever in the axial direction to the brake disc, or the offset angle is less than 180 ° and is in a range of 150 ° to 1 70 °, when the disc brake is designed as a radial brake with an introduction of force into the Antriebswirkhebelarm the rotary lever in the radial direction of a brake disc axis to the brake disc.

The terms "axial" and "radial" are to be understood here as the reference directions of the brake cylinder or their directions of action relative to the brake disk. The term "axial" means that the reference direction of the brake cylinder to the brake disk is axial in the direction of the brake disk axis A disk brake with such a direction of action parallel to the brake disk axis, i.e., axially to the brake disk, is referred to as an "axial brake". The term "radial" means that the reference direction of the brake cylinder extends radially to the brake disk or to the brake disk axis. This type of disk brake is referred to as a "radial brake".

As part of the development and testing has been shown that especially the behavior of the coupling element of the coupling mechanism exerts a significant influence on the hysteresis of Zuspannmechanik and thus the disc brake. This behavior is surprisingly influenced by the offset angle of the drive rocker arm and the output rocker arm.

Under the Antriebswirkhebelarm the arithmetic length of the underlying for the translation of the rotary lever lever from the point of application of the actuating force or from a plane which passes through this point to understand the lever axis of the rotary lever. Accordingly, the Abtriebschwirkhebelarm the arithmetic length of the underlying for the translation of the rotary lever lever from the lever axis of the rotary lever to a center of the coupling element or to the corresponding plane which passes through this center. In particular, it has been found that the rolling path and the sliding path of the coupling element can be reduced by the inventive design of the rotary lever so that an unfavorable influence of the friction work generated thereby is significantly reduced to the entire hysteresis of the application device.

Further investigations have shown that, contrary to the original design of the rotary lever with an offset angle of 90 ° with an axial brake an offset angle in the range of 60 ° to 80 ° is advantageous, with an offset angle of 75 ° is preferred.

In a radial brake, contrary to the original design of the rotary lever with an offset angle of 180 °, an offset angle in the range of 150 ° to 170 ° is advantageous. A particular advantage, i. a significantly reduced hysteresis can be achieved here with an offset angle of 155 °.

In this way, in contrast to the prior art advantageously lower loss work and thus a smaller hysteresis can be achieved by this design of the rotary lever.

Due to the design of the rotary lever may be to achieve a low hysteresis as long as possible, so-called subtraction phase between movements, e.g. Sliding and unwinding of the coupling element, can be achieved. As a result, an addition of movement sequences, that is to say a so-called addition phase, can be avoided almost in the entire working range of the coupling element, which is preferably designed here as a ball.

In addition, in another embodiment, the loss work to achieve a lower hysteresis can be further reduced when the lever axis is offset in a height direction of the disc brake by a distance to a plane of the spindle axis when the disc brake is formed as an axial brake. This advantageously influences a positioning of the coupling element of the coupling mechanism.

The rotary lever can be designed differently. Thus, in one embodiment, it has a lever arm which can be actuated at a drive end by a piston rod of a brake cylinder or another drive. Towards the other end, the rotary lever has at least one drive segment, wherein the at least one rounded coupling element is designed as at least one ball, a hemisphere or the like and is attached to the drive segment. In another embodiment, the rotary lever widens from the drive end to its other end like a fork in two or more lever arms and has at one end or both ends of the fork-like region each have a drive segment, said at least one rounded coupling element each as at least one Ball, a hemisphere or the like. Is formed and attached to the drive segment. In this way, in the case of a single-disc disk brake, the rotary lever can receive the rolling element clamping unit between its arms, which ensures a compact construction. In addition, the rotary lever can also be used in a two-stamped brake.

In a further embodiment, the rounded coupling element is a ball which is gimbal-mounted in the respective drive segment of the rotary lever in a calotte, whereby friction losses are reduced.

An additional embodiment according to claim 7, the embodiment with two preferably parallel aligned Wälzkörpereinheiten, in particular ball ramp mechanisms, which are driven by the advantageously in this case centrally or centrally positioned between these rotary lever.

In one embodiment, the rotatable parts of the at least one Wälzkörperzuspanneinheit, in particular the ball ramp units or the other ball units, penetrated by a Zuspannkolben acting on one or more plungers, resulting in a compact design.

The drive from the rotary lever to the / the Wälzkörpereinheit / s, in particular the ball ramp units or mechanisms, is effected by a drive connection, which may be a ball, hemisphere, part ball or coupling rod, with a ball is particularly preferred.

It is envisaged that the clamping piston is designed as a variable-length threaded sleeve / threaded spindle combinations / which, or enforce a centric opening in the at least one Wälzkörperzuspanneinheit. This also contributes to a space-saving design.

The fact that the ramp reaction disc is fixedly mounted in the brake housing, the reaction torque can thus be introduced directly into the brake housing or the caliper. Frictional losses are thereby further reduced. In a particularly preferred embodiment, the ramp drive disk is pivotable about a spindle axis and axially displaceable along the spindle axis in an application direction in the direction of a brake disk axis. Thus, reaction moments of the ball ramp assembly are passed through the ramp reaction disc in the caliper, wherein from the pivotal movement of the ramp drive disc simultaneously with it an axial movement for applying the brake is generated.

It is provided in a preferred embodiment that the at least one Wälz- bodyzuspanneinheit has at least: the Rampenantriebsscheibe with ramps, which is coupled to the rotary lever via the coupling mechanism with at least one rounded coupling element, Rampenwälzkörper and a ramp reaction disc with ramps, wherein the ramps for the Rampenwälzkörper are provided and are preferably ramped raceways, wherein the ramp reaction disc is fixedly mounted in the brake caliper, the thrust bearing which is axially displaceable together with the Rampenantriebsscheibe, a support plate which carries the thrust bearing and a threaded sleeve, and in each case one of the Zuspann- piston, which the at least one Wälzkörperzuspanneinheit centrally passes through. This ensures a robust arrangement in confined spaces.

In a further preferred embodiment, the at least one Wälzkörperzuspanneinheit in the axial direction of the spindle axis is constructed so that the ramp reaction disc with a top, which faces away from the brake disc, is firmly installed in the brake caliper, wherein arranged on the opposite side of the top of the ramp reaction disc, the ramps are that the ramps of the ramp drive disc are arranged opposite one another, wherein the Rampenwälzkörpern between the ramps are arranged contacting, that are arranged on the ramps opposite side of the ramp drive pulley Wälzkörperaufnahmen, facing Wälzkörperaufnahmen the Axiallagerscheibe, the rolling elements of the thrust bearing between the Wälzkörperaufnahmen these are arranged contacting, that the thrust washer is inserted both in a bore of the support plate and a threaded sleeve, which with the clamping piston in Verbindun g stands, is arranged coaxially around.

The ramp drive disc outputs the force acting in the axial direction on the low-friction thrust bearing, which is designed as a rolling bearing, in the thrust bearing from which passes on the support plate and the threaded sleeve, the force to the threaded rod and the pressure piece. The bearing torque caused by the thrust bearing is so small that the recording and passing on the caliper are unproblematic.

The arrangement according to the invention, in addition to a considerably improved hysteresis behavior compared to the prior art, offers many other advantages.

Thus, a non-cutting and cost-effective production of the components is possible by the preferred structural design of the components.

Due to the conceptual arrangement of the components results in a very compact design for the caliper housing.

The direct power flow results in lower deformation paths on the mechanism and on the brake caliper (no force deflection, in the main force direction, no bending stress on the components, due to the far outside of the center held force introduction into the caliper results in a lower bending load for the caliper housing). This results in a relatively low lifting requirement.

In a two-temple design of the disc brake and the high directivity on the brake pad is advantageous because the Zuspannmechanik is stored directly in the saddle with large span. This results in a low peripheral oblique wear.

Particularly advantageous is a clear linear movement of the application elements (plungers) can be realized. This results in the advantages of a favorable introduction of force in the brake pad and a simple detection of the Zuspannwegs for the realization of additional functions.

The invention will be described in more detail by means of exemplary embodiments with reference to the drawing. It shows:

Fig. 1 is a perspective view of a disc brake according to the invention;

FIG. 2 shows a sectional view of an exemplary embodiment of a brake application device according to the invention of the disc brake according to FIG. 1; FIG.

3 is a plan view of the embodiment of the inventive application device of the disc brake according to the invention of Fig. 2. Fig. 4-4a are side views of the application device of Figure 2-3 with a first rotary lever in different positions.

Fig. 5-5a are side views of the application device of Figure 2-3 with a second rotary lever in different positions.

Fig. 6-6b are schematic representations of a coupling mechanism with the first

Rotary lever of Figure 4-4a in different positions.

Fig. 7-7b are schematic representations of a coupling mechanism with the second rotary lever of Figure 5-5a in different positions.

Fig. 8 is a graph showing a relationship of ball rolling angle and cylinder stroke of a coupling mechanism of Figs. 6-6b;

FIG. 9 is a graph showing a relationship between ball rolling angle and cylinder stroke of a coupling mechanism of FIGS. 7-7b; FIG. and

Fig. 10-1 1 perspective views of a variation of the invention

Disc brake and the application device according to Fig. 1 -3.

A disc brake 10 according to the invention is shown in Fig. 1 in a perspective view. FIG. 2 shows a sectional view of an exemplary embodiment of a brake application device 1 according to the invention of the disc brake 10 according to FIG. 1. In Fig. 3 is a plan view of the embodiment of the application device 1 of the disc brake according to the invention of FIG. 2 is shown. The disc brake 10 shown in FIG. 3 is embodied here as a so-called single-plate disc brake 10.

Brake coordinates U, V, X are for orientation. In this case, the U direction runs in a main direction of travel of a vehicle, not shown, to which the disc brake 10 is assigned. The V direction is referred to below as the height direction, wherein X has an application direction of the disc brake 10 in the direction of a brake disc axis 2 a.

The application device 1 is received in a portion of a Zuspannseite ZS a one or more parts caliper 3, which is preferably designed as a sliding caliper, the disc brake 10. The caliper 3 is mounted on a brake carrier 2 - for example, not shown here camps on one or usually two bearing pins - slidably guided. The caliper 3 encompasses - For example, in the manner of the prior art of EP 0 248 385 A1 - like a frame edge portion of a not shown, but easily imaginable brake disc with the brake disc axis 2a. On both sides of the brake disc are brake pads 4, 4a (brake application side brake pad 4, reaction-side brake pad 4a) with a respective back plate 4b, 4c arranged (Fig. 1).

The brake caliper 3 receives on its reaction side RS the reaction-side brake pad 4a and is provided on its Zuspannseite ZS with a lever housing 3a, in which a rotary lever 5 is arranged. A mounting flange 3b serves for fastening a pneumatic, electromotive or spring-actuated brake cylinder (not shown here). The effective direction of such a brake cylinder runs parallel to the brake disk axis 2a in the disk brake 10 shown in FIG. A disc brake 10 having such a direction of action parallel to the disc axis 2a, i. axially to the brake disc, also referred to as Axialbremse.

With the application device 1, the application-side brake pad 4 is pressed parallel to the brake disk axis 2a in the application direction X (FIGS. 2 and 3) directly against the brake disk, whereas the reaction-side brake pad 4a is pulled with the displaceable brake caliper 3 against the application direction X against the brake disk ,

The application device 1 has as a drive element to the rotary lever 5, which is adapted to be moved by a piston rod of the brake cylinder, not shown here. For this purpose, the rotary lever 5 has a drive end 5a with a recess 7 for cooperation with such a piston rod, wherein the piston rod of the brake cylinder through an opening 3c (see Fig. 10) can engage in the mounting flange 3b of the caliper 3. The rotary lever 5 will be described below in more detail.

The terms "bottom" and "top" of various components of the application device 1 indicate the orientation of these components with each other. Thus, the upper side is to be understood as that side of a component which is remote from the brake pad 4, the underside facing the brake pad 4.

A special feature of the application device 1 is a ball ramp unit 20, which is driven by means of the rotary lever 5. The application device 1 has a Wälzkörperzuspanneinheit 22 with a spindle axis 12, which comprises the following components and functional units, which are arranged in the order shown in the direction of the brake pad 4, comprising: the ball ramp unit 20 with a ramp reaction disc 14 with ramps 18a, Rampenwälzkörper 18, and a ramp drive pulley 13 with ramps 18b; a thrust bearing 21 with rolling elements 19 and a thrust washer 15, a support plate 24, a threaded sleeve 16 with an internal thread 16a, a threaded spindle 17 with an external thread 17a and a pressure piece 23rd

The Wälzkörperzuspanneinheit 22 is penetrated by the threaded spindle 17, at the brake pad 4 facing the end of the pressure piece 23 is arranged or formed. The threaded spindle 17 is formed with the threaded sleeve 16 as Gewindehülsen- / threaded spindle combination, which is also referred to as so-called Zuspann- piston. The threaded spindle 17 and the threaded sleeve 16 are screwed together so that wear of the brake pads 4, 4a and the brake disc can be compensated by a relative screwing this threaded sleeve / threaded spindle combinations, since the total length of the application unit 1 in the direction X between the support on the brake pad 4th and the caliper 3 is changed.

The ramp reaction disc 14 has an upper surface 14a with attachment portions 14b and is secured by fasteners 14c, e.g. through the mounting portions 14 b are inserted through (see Fig. 1 1), mounted in the caliper 3 against rotation and immovable. The fasteners 14c may be e.g. Screws, bolts, studs or the like. be. The top 14a is here formed as a plane surface, but it may also be e.g. be provided with projections and / or recess for receiving projections to form a rotationally fixed attachment.

On its underside, the ramp reaction disc 14 is provided with the ramps 18a, which cooperate with the Rampenwälzkörpern 18, which are formed here as balls.

The ramp drive pulley 13 is provided on its upper side with ramps 18b, which opposite to the ramps 18a of the underside of the ramp reaction disc 14 in opposite directions. Between the ramps 18a and 18b, the Rampenwälzkörper 18 are arranged. The ramp reaction disc 14 with its ramps 18a, the ramp roller bodies 18 and the ramp drive disc 13 with the ramps 18b ih- Here top form here a ramp mechanism, in particular a ball ramp mechanism, the ball ramp unit 20th

Formed on the circumference of the ramp drive pulley 13 is a radially outwardly extending projection as a coupling section 29 (see Figures 5-5a, best seen in Figure 11), which together with a coupling element 27, here formed as a ball (Fig. 5-5a), with a drive segment 8 of the rotary lever 5 forms a coupling mechanism 26. The coupling mechanism 26 will be described below in detail.

The bottom of the ramp drive pulley 13 has a Wälzkörperaufnahme 19 a for cooperation with the rolling elements 19. Opposite, the thrust washer 15 is arranged, which has on its upper side a further Wälzkörperaufnahme 19b, which points to the one Wälzkörperaufnahme 19a. Between the Wälzkörperaufnahmen 19 a, 19 b, the rolling elements 19 are arranged and received in these. The rolling body receivers 19a, 19b are e.g. Grooves as in a thrust bearing. The ramp drive disc 13 with the one Wälzkörperaufnahme 19a, the rolling elements 19 and the thrust washer 15 with the other Wälzkörperaufnahme 19b form the thrust bearing 21st

The thrust washer 15 is received together with the threaded sleeve 16 in a bore of the support plate 24.

The internal thread 16a of the threaded sleeve 16 corresponds to the external thread 17a of the threaded spindle 17, which is screwed into the internal thread 16a of the threaded sleeve 16.

At the lower end of the threaded spindle 17, the pressure piece 23 is mounted, which is arranged with its lower end in a recess of the back plate 4b of the tension-side brake pad 4.

The ramps 18a, 18b of the ball ramp unit 20 of the Wälzkörperzuspanneinheit 22 are formed in the bottom of the ramp reaction disc 14 and in the top of the ramp drive pulley 13 and extend in each case inclined at a constant or variable angle to the respective sides of the discs 13 and 14 and . inclined to the brake disc plane (or parallel to the friction surface of the brake pad 4). The application device 1 is arranged in an opening of the application side ZS of the brake caliper 3. The opening is closed by a cover plate 25. The Zuspannvorhchtung 1 is sealed to the cover plate 25 with seals, not shown, for example, bellows against the environment. Between the cover plate 25 and the carrier plate 24 of the application device 1, a return spring 11 is provided on each side of the application device 1 (FIG. 3).

The rotary lever 5 has two lever arms 6, which spread starting from the drive end 5a with the recess 7 here in a preferred embodiment fork-like. In this embodiment, one of the lever arms 6 is connected to a further lever arm at an angle. The other lever arm is formed as a drive segment 8, which is additionally connected to the associated lever arm 6 via a stiffener 6a.

Between the fork-like spread lever arms 6, the Wälzkörperzuspannein- unit 22, preferably centrally located.

Both ends of the lever arms 6 are pivotable - for example, each by means of a sliding bearing - mounted on a lever bearing pin 9 with a lever axis 9 a, which is supported in a region around the ends of the lever arms 6 around on the inner wall of the caliper 3.

The lever bearing bolts 9 may also be formed integrally directly with the rotary lever 5, which then has a corresponding bearing pin-like contouring, which is supported in a corresponding bearing contour, if necessary with plain bearings or roller bearings on the brake caliper (not shown here).

In this case, the end of the drive segment 8 for receiving the coupling element 27 of the coupling mechanism 26 with a cap 28 (in dashed lines in Fig. 4-4a and 5-5a indicated) is formed.

In the drive segment 8 of the rotary lever 5, the ball 27 is mounted and guided in the hemispherical dome 28 with low friction. The cap 28 performs the function of a ball joint and is preferably designed as a sliding bearing. The ball as a coupling element 27 serves as a coupling member between the drive element "rotary lever 5" and the output element "ramp drive pulley 13".

The rotary lever 5 is only a drive element, but does not directly generate a movement in the application direction X in order to effect the working stroke on the pressure piece 23. The rotary lever 5 can thus be designed compact and inexpensive. Also, it can be dispensed with a rolling bearing on him - preferably but not mandatory.

When applying and releasing the brake, a pivoting of the rotary lever 5 via the coupling mechanism 26 is transmitted to the ramp drive pulley 13 in a pivoting movement of the ramp drive pulley 13 about the spindle axis 12. The return springs 1 1 are provided to reset the brake when releasing.

To clamp the disc brake 10, the rotary lever 5 is pivoted about the lever axis 9a during a movement of the piston rod of the brake cylinder, wherein the ramp drive disc 13 of the rolling element ancillary units 15 is pivoted via the coupling mechanism 26. In this case, the pivoting movement of the ramp drive pulley 13 about the spindle axis 12 via the ball ramp unit 20 in a longitudinal movement, i. an axial movement of the threaded sleeve 16 with the threaded spindle 17 in the direction of the spindle axis 12 in the application direction X parallel to the brake disk axis 2a, overcoming the Bremshubes / stroke until the brake pad 4 comes to rest against the brake disc to decelerate their rotation.

It is particularly advantageous that the reaction forces to move the

Support caliper 3 directly on the ramp reaction disc 1 of Wälzkörperzuspan- neinheit 22 on the inside of the caliper 3, and that these forces are not supported by a cross member and / or the rotary lever 5 rear of the caliper 3.

It should be mentioned that in FIGS. 2 and 3, for the sake of simplicity, no seals to the pressure piece 21 are shown, as they are basically known from the prior art and can also be provided here. Also, the caliper 3 may well be designed as a one-piece caliper 3.

The tensioning on the reaction-side brake lining 4a can take place via a sliding caliper or, for example, via a reaction-side application device or a displaceable brake disk which is pressed against the brake lining on the opposite side of the brake disk. In the illustrated embodiment of the application device 1, the transmission of the pivoting movement of the rotary lever 5 by means of the coupling element 27, preferably a rolling element, in particular at least one ball takes place.

The ramp unit 20 has a ramp mechanism with the least possible friction, which is ensured by the ramp balls 28. By rolling the ramp balls 28 on the contours of the ramps 18a, 18b results in a very low rolling resistance and thus also a very low loss by frictional resistance. This is very important for the dosing of the disc brake 10. This property is expressed by the amount of so-called hysteresis. Under the hysteresis here is the difference of the clamping force during pressure build-up and pressure reduction to understand.

In addition to the rolling resistance of the ramp balls 18 and the rolling elements 19 of the thrust bearing 21, which is designed here as an axial ball bearing with balls as rolling elements 19, and the sliding movement of the cylinder plunger in the recess 7, which is also referred to as a lever pan, the pivot bearing of the rotary lever. 5 and the rolling and sliding behavior of the ball used as coupling element 27 on the hysteresis an influence. In the context of development and testing, it has been shown that especially the behavior of the coupling element 27 makes a clear influence on the hysteresis.

In the disk brake 10 in einstempeliger embodiment of FIG. 1 -3 performs the ramp drive pulley 13 as described above, both a pivoting movement and a linear lifting movement. These superimposed movements are compensated by the ball as a coupling element 27 of the coupling mechanism 26. The ball is gimballed in the drive segment 8 in the cap 28. For a level of friction work between ball and dome 28 is u.a. the relative movement of the ball as a transmission element or coupling element in the formed as a sliding bearing cap 28 of the drive segment 8 of the rotary lever 5 crucial.

FIGS. 4-4a show side views of the application device 1 according to FIGS. 2-3 with a first rotary lever 5. FIG. 4 shows the application device 1 in the released position, and FIG. 4a shows the application device 1 in the tightened position.

The first rotary lever 5 according to FIG. 4-4a has the lever arm 6, which at its free end has the drive end 5a with the recess 7 and with its other end in the lever axis 9a connected to one end of the drive segment 8. that is. The free end of the drive segment 8 is provided with the cap 28 for receiving the coupling element 27.

Furthermore, in Figures 4-4a and 5-5a a Antriebswirkhebelarm 30 and a driven Schwirkarm 31 are located. Under the Antriebswirkhebelarm 30, the arithmetic length of the underlying for the translation of the rotary lever 5 lever from the point of application of the actuating force in the recess 7 of the drive end 5a and from a plane passing through this point to the lever axis 9a of the rotary lever 5 to understand. Accordingly, the Abtriebswirkhebelarm 31 is the mathematical length of the underlying for the translation of the rotary lever 5 lever from the lever axis 9a of the rotary lever 5 to the center 32 of the coupling element 27 (see Fig. 6-6b, 7-7b) or to the corresponding level, which passes through this center 32.

The Antriebswirkhebelarm 30 and the Abtriebswirkhebelarm 31 form an angle in the lever axis 9a, which is referred to here as the offset angle γ. In the first rotary lever 5 shown in Fig. 4-4a, the offset angle γ 90 °.

A vertex axis 9b arranged parallel to the spindle axis 12 passes through the rotary lever axis 9a. In the side views of FIGS. 4-4a, the apex axis 9b coincides with the spindle axis 12.

The output drive lever arm 31 forms a vertex angle β with the vertex axis 9b.

The pivoting movement of the rotary lever 5 extends around the lever axis 9a. In this case, the coupling element 27 moves, i. the ball, on a circular arc around the lever axis 9a. An imaginary intersection of this circular arc with the apex axis 9b in the projection of Fig. 4a is referred to herein as a vertex of this circular arc. In this imaginary point of intersection, the vertex angle β of the Abtriebswirkhebelarms 31 with the apex axis 9b has a value of 0 °, which is not shown, but easy to imagine.

In the released position of the disc brake 10 shown in Fig. 4, i. in the initial position, the value of the vertex angle ß is about 30 °, wherein the ball is in Fig. 4 right of the apex axis 9b.

When the disc brake 10 is clamped, as shown in FIG. 4a, the ball pivots through the apex (point of intersection of the arc around lever axis 9a with the apex axis 9b) to an end point to the left of the apex axis 9b. there is the vertex angle ß in this example about 18 °. The ball pivots in the full stroke shown in Fig. 4a well above the apex of the circular arc of the ball (coupling element 27) about the lever axis 9a.

During such a complete working stroke of the first rotary lever 5 (FIG. 4 according to FIG. 4 a), it is shown that the sliding path of the ball has a non-linear behavior as a function of the travel of the rotary lever 5. This will be explained in more detail below in connection with FIGS. 6-6b and FIG. 8.

FIGS. 5-5a show side views of the application device 1 according to FIGS. 2-3 with a second rotary lever 5. FIG. 5 shows the application device 1 in the released position and FIG. 4a shows the application device 1 in the tensioned position.

In contrast to the first rotary lever 5 according to FIGS. 4-4a, the second rotary lever 5 has an offset angle γ of 75 °. In addition, the lever axis 9a is offset with the apex axis 9b by a distance V1 from the spindle axis 12 in the height direction V of the disc brake 10 (see FIG. 1).

In this arrangement, the apex angle ß in the initial position in Fig. 5 is about 45 ° and in the cocked position of Fig. 5a about only 3 °. The ball pivots at full stroke thus only slightly above the vertex, i. about the intersection of the circular arc of the ball about the lever axis 9a with the apex axis 9b.

For clarity, Figures 6-6b show schematic representations of the coupling mechanism 26 with the first rotary lever 5 of FIG. 4-4a in different positions. Figures 7-7b also show schematic representations of the coupling mechanism 26 with the second rotary lever 5 of FIG. 5-5a in different positions.

Figures 6 and 7 respectively show the released position, ie the starting position. FIGS. 6a and 7a each show a position with approximately half the stroke of the respective rotary lever 5, and FIGS. 6b and 7b respectively show the clamped position. Fig. 8 is a graph showing a relationship of ball rolling angle α and cylinder stroke of the coupling mechanism 26 of Figs. 6-6b, and Fig. 9 is a graph showing a relationship of ball rolling angle α and cylinder stroke of the coupling mechanism 26 of FIG. 7-7b. In FIGS. 6-6b and 7-7b, the coupling mechanism 26 and the ball ramp unit 20 are shown schematically projected onto the plane of the drawing. The ramp reaction disc 14 is fixedly connected to the caliper 3 at its upper side. The ramp balls 18 are not shown, only the ramp 18a of the ramp reaction disc 14 and the opposite opposing ramp 18b of the ramp drive pulley 13. The rotary lever 5 is shown symbolically only with its Antriebswirkhebelarm 30 and Abtriebswirkhebelarm 31, with its lever axis 9a with a bearing symbol fixed in the brake caliper is arranged.

The output drive lever arm 31 is shown at its free end with the cap 28, in which the ball is slidably received as a coupling element 27. The cap 28 is provided with an arrow as a reference cap 28a, which is fixedly connected to the cap 28 and constitutes a reference for the cap 28a relative to the coupling element 27.

The coupling element 27 has here as a ball on a center 32 by which the ball in a ball rolling angle α in the cap 28 is pivotable. The position of the ball is indicated by an arrow as a reference coupling element 33, which is in the starting position in Fig. 6 in a plane with the arrow reference calotte 28a. The coupling element 27 is constantly in contact with the coupling portion 29 of the ramp drive pulley 13, wherein the coupling portion 29 forms a non-descript rolling surface for the coupling element 27.

Scheme coordinates x, y, z are for orientation in the schematic figures 6-6b and 7-7b. They are not to be confused with the brake coordinates U, V, X. The coordinate x symbolizes the adjustment direction of the ramp drive pulley 13, which also moves axially in the direction of the coordinate z. The lever axis 9a and an imaginary axis through the center 32 of the coupling element 27 extend parallel to the y-direction here. The ball rolling angle α denotes a pivoting of the ball as a coupling element 27 about the y-direction.

In Fig. 8, the ball rolling angle α of the coupling element 27 of the first rotary lever of FIG. 4-4a is plotted over a cylinder stroke H. The cylinder stroke H acts on the drive end 5a of the rotary lever 5 and generates a pivoting of the rotary lever 5 about the lever axis 9a. Accordingly, FIG. 9 shows the ball rolling angle α of the coupling element of the second rotary lever according to FIGS. 5-5a as a function of the cylinder stroke H. With reference to FIGS. 6-6b, as the stroke or cylinder stroke H or increasing pivoting of the rotary lever 5 about the lever axis 9a increases, the angle of rotation as ball rolling angle .alpha. Of the ball increases disproportionately. In a hysteresis measurement, this is reflected in an ever-widening hysteresis curve.

In the following, the term transmission ball 27 is used for the coupling element 27.

The relative movement of the transmission ball 27 (indicated by the arrow reference coupling element 33) in the calotte 28 (relative to its arrow reference calotte 28a) of the rotary lever 5 results on the one hand from the pivoting angle of the rotary lever 5 about the lever axis 9a and on the other from the rolling movement the transmission ball 27 on the coupling portion 29 of the ramp drive pulley 13th

A more detailed analysis of this sequence of movements has shown that, depending on the pivoting angle of the rotary lever 5 (or the ramp drive pulley 13), both the addition and the subtraction can occur in the previously described components of motion. Measurement and simulation studies showed that in the first part of the actuation phase of the rotary lever 5 (Fig. 6-6a), the hysteresis is significantly smaller than in the second part. The reason for this behavior lies in the specific kinematics of the application mechanics. Since in the first part of the sequence of movements the rolling direction of the transmission ball 27 and the pivoting direction of the rotary lever 5 are in the same direction (FIGS. 6-6a), a subtraction of the two path components results (FIG. 6a). In the second part of the movement sequence (FIG. 6b), however, the previously described sequence is in opposite directions and thus leads to an addition of the path components.

When the position of Fig. 6a is taken, the transmission ball has 27 due to their unwinding at the coupling portion 29 of the ramp drive disc 13 is rotated slightly about its center 32 in a clockwise direction, with their relative movement to the cap 28 is slightly larger. This is shown by the angular distance from the arrows reference calotte 28a and reference coupling element 33. This results from the subtraction of the two path components.

In the position according to FIG. 6a, the ramp drive disk 13 is displaced in the x-direction (ie pivoted about the spindle axis 12) and simultaneously displaced in the axial direction in the negative z-direction downward due to the ramps 18a, 18b. After taking the clamped position of Fig. 6b, the transmission ball 27 has now rotated counterclockwise about its center 32, wherein the angular distance between their arrow reference coupling element 33 relative to the arrow reference dome 28a of the cap 28 has grown significantly, resulting from the addition the path components results.

The ramp drive pulley 13 is thereby displaced further in the x-direction and simultaneously adjusted further in the axial direction in the negative z-direction downwards.

The above-described operations are shown in the graph of FIG. 8. The subtraction phase can be seen in the first part of the curve in the range of a lever stroke H from 0 to about 30, wherein the subtraction phase then passes into the addition phase and leads to high ball rolling angles α.

In the sense of a low hysteresis, the longest possible subtraction phase should be sought. As already mentioned above, upon closer examination of the movements of the rotary lever 5 and ramp drive pulley 13, it can be seen that in the first phase (FIGS. 6-6a) both the transmission ball 27 and the ramp drive pulley 13 move in the axial, negative z-direction (corresponds to the application direction X in FIG. 3). In the second phase (Figure 6b), however, the direction of movement of the transferring ball 27 is in the opposite direction to the axial direction of movement of the ramp drive pulley 13 (i.e., in the positive z-direction).

This results in an addition of the path components with the previously described negative influence on the hysteresis (FIG. 6b), which is due to the large relative movement of the transmission ball 27 in the cap 28.

While in the first part of the application movement the transmission ball 27 moves on its circular path around the lever axis 9a from the starting point (FIG. 6 and FIG. 4) to the vertex (FIG. 6a), an opposite movement takes place in the second part. It should also be noted that with increasing distance from the vertex (Fig. 6b and Fig. 4a), this second component of motion increases disproportionately and thus the influence on the hysteresis, as in the curve of Fig. 8 is clearly visible.

Figures 7, 7a and 7b show in comparison to the figures 6, 6a and 6b, the movements with the second rotary lever 5 of FIG. 5-5a.

The second rotary lever 5 has an offset angle γ of 75 ° and thus smaller than that of the first rotary lever 5 at 90 °. It can be seen in the first part of the movement sequence up to the half stroke (FIGS. 7-7a) that the transmission ball 27 moves on the one hand in the same direction of movement (in the negative z direction) as the ramp drive disk 13, and on the other hand only a very small relative movement between transmission ball 27 and the cap 28 occurs. This can be clearly recognized by the very small angular distance between the arrows reference coupling element 33 of the transmission ball 27 and reference calotte 28a of the cap 28.

Furthermore, it should be noted that the transmission ball 27 has not reached the apex on its circular path around the lever axis 9a at half stroke (FIG. 7a). This means that the subtraction phase is prolonged and only shortly before reaching the end position (clamped position) of FIG. 7b goes into the addition phase. In other words, the vertex is exceeded by the transmission ball 27 just before the end position.

Thus, Fig. 7b clearly shows that at the end of the second movement phase, the angular distance between the arrows reference coupling element 33 of the transmission ball 27 and reference calotte 28a of the cap 28 in comparison to the angular distance of Fig. 6b significantly lower fails. This means that less friction between the transfer ball 27 and the cap 28 is formed, resulting in a smaller hysteresis.

The rotary lever 5 in the second embodiment according to Fig. 5 and Fig. 7-7b is designed with the offset angle γ <90 ° such that almost in the entire working area, ie in the first and second movement phase until shortly before reaching the end position (Fig. 7b), the transmission ball 27 does not move or moves only slightly beyond the vertex of its circular path about the lever axis 9a. In this way, the phase with the unwanted addition of the path components can be avoided or significantly restricted.

This is also clearly illustrated by the curve of FIG. 9. The ball rolling angle α passes through at a cylinder stroke H from 0 to 20 about 15 ° and then to the maximum cylinder stroke H about 40 °, which together are about 55 °. In contrast, the ball rolling angle α of FIG. 8 undergoes a total range of about 85 °. In addition, the curve of FIG. 9 is flatter than that of FIG. 8.

In the present case of the exemplary embodiment with the second rotary lever 5 according to FIGS. 5 and 7-7b, an offset angle γ with the value of approximately 75 ° has proved to be the best solution on the basis of tests. This interpretation applies to an order of tion of the brake cylinder with a largely to the application direction X and to the brake disk axis 2a parallel operating direction as described in connection with FIG.

FIG. 10 shows a plan view of a variant of the disk brake 10 according to the invention with a tightening device 1 according to FIG. 11 with a so-called radial introduction of force. In contrast to the embodiment according to FIG. 1, the actuation direction of the brake cylinder (not shown) extends at right angles to the brake disk axis 2a or spindle axis 12. The term "radial" is to be understood here as meaning the reference direction of the brake cylinder to the brake disk. means that the reference direction of the brake cylinder to the brake disc extends axially in the direction of the brake disc axis 2a.

Fig. 1 1 shows the variation of the rotary lever 5 associated with the variant of the disc brake 10 shown in Fig. 10. The lever arm 6 is designed as a main lever arm with a plurality of creases such that the drive end 5a is centered, i. lies in the spindle axis 12. A stiffener as in the rotary lever 5, such. according to Fig. 3, is not required. The other lever arm is formed as a support arm 6b with a smaller cross section and connected at its end via a bearing pin sleeve 6c with the lever arm 6. Lever arm 6 and support arm 6b are arranged fork-shaped, but branch at a distance from the drive end 5a in the direction of the spindle axis 12th

Since in this embodiment of the radial disc brake 10 of FIG. 10, the brake cylinder has an axial disc brake 10 of FIG. 1 different angular position (which is easily recognizable due to the position of the mounting flange 3b of the caliper 3), accordingly, the offset angle γ of associated rotary lever 5.

In the rotary lever 5 of FIG. 1 1, the Antriebswirkhebelarm 30 and the Abtriebswirkhebelarm 31 are indicated including the offset angle γ indicated. Regardless of the subject matter described above, the offset angle γ has a value of 180 °. Taking into account the above theme, an offset angle γ smaller than 180 ° has the value of e.g. 155 ° proved to be favorable.

This relationship applies analogously to all other possible brake cylinder arrangements.

By the embodiments described above, the invention is not limited, but modifiable within the scope of the appended claims. For example, it is conceivable that the application device 1 can also be used for two- or multi-speed disc brakes.

Instead of a ball as a coupling element 27 and a differently shaped, rounded coupling element for coupling the rotary lever 5 with the ramp drive pulley 13 could be used, for example, designed as a hemisphere or part ball coupling element, or a coupling rod.

Reference numeral, r Zuspannvorrichtung

brake carrier

a brake disc axle

caliper

a lever housing

b Mounting flange opening

, 4a brake pad

b, 4c back plate

lever

a drive end

lever arm

a stiffening

b support arm

c bearing pin sleeve

deepening

drive segment

Lever bearing bolt A lever axle

b vertex axis

0 disc brake

1 return spring

2 spindle axis

3 ramp drive pulley4 ramp reaction disc4a top

4b Mounting section4c Mounting element5 Thrust bearing disc6 Threaded sleeve

6a internal thread

7 threaded spindle

7a external thread

8 ramp ball

8a, 18b ramps 19 rolling elements

19a, 19b Wälzkörperaufnahme

20 ball ramp unit

21 thrust bearings

22 Wälzkörperzuspanneinheit

23 pressure piece

24 carrier plate

25 cover plate

26 coupling mechanism

27 coupling element

28 dome

28a reference dome

29 coupling section

30 drive lever arm

31 Output swing arm

32 center point

33 reference coupling element

H cylinder stroke

RS back side

ZS Zuspannseite

U, V, X Brake Coordinates

V height direction

V1 distance

X application direction x, y, z scheme coordinates α ball rolling angle

ß vertex angle

Y offset angle

Claims

claims

1 . Disc brake (10), in particular a disc brake (10) which can be actuated by means of a piston rod of a pneumatically or electromotively operated brake cylinder, with a brake caliper (3), preferably frame-like, an edge region of a brake disc on which at least one brake pad (4, 4a) is arranged on both sides engages, wherein the brake caliper (3) on a Zuspannseite (ZS) of the brake disc in an opening a clamping device (1) receives, which has at least the following features: a) an inner, ie arranged inside the caliper (3)

Rotary lever (5) with a preferably parallel to the brake disc aligned lever axis (9a), wherein a Antriebswirkhebelarm (30) and a Abtriebswirkhebelarm (31) of the rotary lever (5) in the lever axis (9a) form an offset angle (γ); b) at least one Wälzkörperzuspanneinheit (22) having a spindle axis

(12) and at least one supply piston movable perpendicular to the brake disk and designed to overcome the working stroke or to apply the application-side application piston with the brake lining (4) to the brake disk as a result of a pivoting of the rotary lever (5) during braking, wherein the at least one rolling element clamping unit (22) comprises a ball ramp unit (20) with a ramp drive pulley (13), ramp balls (18) and a ramp reaction disc (14), c) a drive connection between the rotary lever (5) and the at least one rolling element clamping unit (22 ) is formed as a coupling mechanism (26) with at least one rounded coupling element (27), characterized in that d) that the offset angle (γ) is less than 90 ° and in a range of 60 ° to 80 ° when the disc brake ( 10) as an axial brake with an introduction of force in the Antriebswirkhebelarm (30) of the rotary lever (5) in the axial direction to the brake disc is formed, or that the offset angle (γ) is less than 180 ° and is in a range of 150 ° to 170 ° when the disc brake (10) as a radial brake with a force application in the Antriebswirkhebelarm (30) of the rotary lever (5) in the radial direction of a brake disc axis (2a) is formed to the brake disc.

2. Disc brake (10) according to claim 1, characterized in that the offset angle (γ) has a value of 75 ° when the disc brake (10) is designed as an axial brake, or that the offset angle (γ) has a value of 155 ° when the disc brake (10) is designed as a radial brake.

3. Disc brake (10) according to claim 1 or 2, characterized in that the lever axis (9a) is offset in a height direction (V) of the disc brake (10) by a distance (V1) to a plane of the spindle axis (12), when the disc brake (10) is designed as an axial brake.

4. Disc brake (10) according to any one of the preceding claims, characterized in that the rotary lever (5) has at least one actuatable at a drive end (5a) of a piston rod of a brake cylinder or other drive lever arm (6).

5. Disc brake (10) according to claim 4, characterized in that the rotary lever (5) towards the other end at least one drive segment (8), wherein the at least one rounded coupling element (27) as at least one ball (27), a hemisphere or the like. Is formed and attached to the drive segment (8).

6. Disc brake (10) according to claim 4 or 5, characterized in that the rotary lever (5) widens towards the other end like a fork and at one or both ends of the fork-like region each having a drive segment (8), wherein the at least a rounded coupling element (27) is designed in each case as at least one ball (27), a hemisphere or the like and is attached to the drive segment (8).

7. Disc brake (10) according to any one of claims 4 to 6, characterized in that the rounded coupling element (27) is a ball (27) which in the respective drive segment (8) of the rotary lever (5) in a cap (28). is cardiac stored.

8. Disc brake (10) according to any one of the preceding claims, characterized in that two or more of Wälzkörperzuspanneinheiten (22) are provided.

9. Disc brake (10) according to claim 8, characterized in that the rotatable or pivotable parts of the at least one Wälzkörperzuspan- neinheit (22), in particular the ball ramp units (22) or the other ball units, are traversed by a Zuspannkolben on a or several pressure pieces (23) act.

10. Disc brake (10) according to any one of the preceding claims, characterized in that the Zuspannkolben is designed as a variable-length threaded sleeve / threaded spindle combination with a threaded sleeve (16) and a threaded spindle (17) or a central opening in the at least one Wälzkörperzuspanneinheit ( 22).

1 1. Disc brake (10) according to one of the preceding claims, characterized in that the ramp reaction disc (14) of the at least one Wälzkörperzuspanneinheit (22) fixed in the caliper (3) is installed.

12. Disc brake (10) according to any one of the preceding claims, characterized in that the ramp drive disc (13) about the spindle axis (12) pivotable and along the spindle axis (12) in a Zuspannrichtung (X) in the direction of a brake disc axis (2a) axially displaceable is.

13. Disc brake (10) according to claim 12, characterized in that the at least one Wälzkörperzuspanneinheit (22) has at least the following: a) the Rampenantriebsscheibe (13) with ramps (18b) with the rotary lever (5) via the coupling mechanism (26 ) is coupled to the at least one rounded coupling element (27), ramp balls (18) and a ramp reaction disc (14) with ramps (18a), the ramps (18a, 18b) being provided for the ramp rolling elements (18) and preferably being ramped raceways , wherein the ramp reaction disc (14) is fixedly mounted in the caliper (3), b) a thrust bearing (21) which together with the ramp drive disc

(13) is axially displaceable, c) a support plate (24) which carries the thrust bearing (21) and the threaded sleeve (16), and d) a clamping piston, which passes through the at least one Wälzkörperzuspanneinheit (22) centrally.

14. Disc brake (10) according to claim 13, characterized in that the at least one Wälzkörperzuspanneinheit (22) in the axial direction of the spindle axis (12) is constructed so that the ramp reaction disc (14) having an upper side (14 a) of the brake disc is fixedly mounted in the brake caliper (3), wherein at the top (14a) opposite side of the ramp reaction disc (14) the ramps (18a) are arranged such that the ramps (18a) opposite the ramps (18b) of the ramp drive disc (18a) 13) are arranged in opposite directions, wherein the Rampenwälzkörper (18) between the ramps (18 a, 18 b) are arranged contacting, that at the ramps (18 b) opposite side of the ramp drive pulley (13) Wälzkörperaufnahmen (19 a) are arranged, which Wälzkörperaufnahmen ( 19b) of an axial bearing disc (15) are opposite, wherein the rolling elements (19) of the axial bearing (21) between the Wälzkörperaufnahmen (19a, 19b) contacting them are ordered that the thrust washer (15) is inserted both in a bore of the support plate (24) and around the threaded sleeve (16), which is in communication with the clamping piston, is disposed around coaxially.