DE202018002963U1 - Disc brake and brake actuation mechanism - Google Patents

Abstract

A brake actuation mechanism for a disc brake with a reinforcing mechanism (A) for introducing a clamping force for the braking operation, - a pressure element (C) for transmitting the application force to a brake disc, wherein the reinforcing mechanism (A) and the pressure element (C) cooperate so that the Pressure element (C) by a displacement movement of the reinforcing mechanism (A) performs a translational movement in the direction of the brake disc, - and an adjusting device (B) to compensate for pad wear, wherein an input element of the adjusting device (B) is set in rotation by this translational movement, the is formed as a spindle (8) of a ball screw (7) with a threaded portion (10) which is connected via balls (12) with a nut (14) of the ball screw drive (7) in a rotatable connection, wherein the balls (12) in at least a groove (15; 53) of the threaded portion (10) are guided, characterized in thatdi e has at least one groove (15, 53) at their two ends each stop (54) which limit the circumferential travel of the balls (12).

Description

The present invention relates to a brake actuation mechanism for a disc brake and a disc brake, in particular for commercial vehicles, having such a brake actuation mechanism.

In this case, the invention comprises disc brakes which have either a sliding caliper or a fixed caliper, and which engage over one or more brake discs. The invention relates primarily, but not exclusively, to partially coated disc brakes.

Disk brakes, especially for heavy trucks, are known in a variety of embodiments, both in terms of the type of brake actuation mechanism, the manner of transmitting the braking force to one or more discs and the nature of the adjustment to compensate for wear of the brake pads.

A particular embodiment of a brake actuator used in disc brakes is, for example, International Application WO 2011/113554 A2 the applicant known. The known from this application brake actuation mechanism is characterized by an extremely compact design, which is associated with a smaller footprint in the housing of the caliper and with a lower weight. All components of this brake actuation mechanism are functionally cooperatively mounted in the caliper by means of a rod mounted in the housing of the caliper in the axial direction so as to act in parallel with the axis of rotation of the brake disc. As a result of a displacement movement of the reinforcing mechanism performs a pressure element together with an adjusting a translational movement in the direction of the brake disc to transmit the clamping force.

The adjusting device for the compensation of wear has a torque clutch, which is torque-controlled and the selective transmission of a rotational direction-dependent rotation between components of the torque clutch is used. In addition, the adjusting device still has a one-way clutch, in which two rotatably mounted on the rod elements, an inner receiving sleeve and a hollow shaft are interconnected by means of a freewheeling spring, wherein the one-way clutch is designed so that it during a brake actuation rotational movement between the transmits both elements while slipping on brake release.

For exact operation in terms of delivery and transmission of the braking force and the readjustment in the known from the prior art brake actuation mechanism is hereby expressly to the disclosure of the WO 2011/113554 A2 directed. Other, similarly designed brake actuation mechanisms are for example from the WO 2013/083857 A2 , of the WO 2014/106672 A2 or the WO 2015/140225 A2 the applicant, to which also incorporated herein by reference.

The above-mentioned prior art brake operating mechanisms have in common that a hollow shaft rotatably supported on the rod serves as an input member for the adjusting device and is directly rotated by the lever of the reinforcing mechanism. For this purpose, a pin or similar element is provided on the hollow shaft at a suitable location, wherein the pin projects radially from the hollow shaft and is received by a recess in the lever, in the region of its pivot bearing surface with a defined game. In this way, the hollow shaft can be rotated by a pivoting movement of the lever in rotation, which is then introduced into the adjusting device.

In frequent brake applications, such as may occur in buses in public transport, however, the connection of pin and recess may be exposed to increased wear, which is undesirable for reasons of reliability and service life.

To achieve increased reliability in a simultaneously compact design of the disc brake and to reduce the wear of an adjuster used in such is used in the Int. Patent application WO 2018/015565 A1 the applicant proposed a disc brake with a brake actuation mechanism, wherein an input element of the adjusting device is formed as part of a ball screw.

The present invention relates to a development of such a brake actuation mechanism with the aim of further increasing the reliability of the adjuster.

For this purpose, the invention proposes a brake actuation mechanism according to claim 1 and a disc brake having such a brake actuation mechanism according to claim 8.

• - einen Verstärkungsmechanismus zur Einleitung einer Zuspannkraft für den Bremsvorgang,
• - ein Druckelement zur Übertragung der Zuspannkraft auf eine Bremsscheibe, wobei der Verstärkungsmechanismus und das Druckelement so zusammenwirken, dass das Druckelement durch eine Verlagerungsbewegung des Verstärkungsmechanismus eine Translationsbewegung in Richtung auf die Bremsscheibe ausführt,
• - und eine Nachstelleinrichtung zum Ausgleich eines Belagverschleißes, wobei ein Eingangselement der Nachstelleinrichtung durch diese Translationsbewegung in Drehung versetzbar ist, das als Spindel eines Kugelgewindetriebs mit einem Gewindeabschnitt ausgebildet ist, der über Kugeln mit einer Mutter des Kugelgewindeantriebs in einer drehbaren Verbindung steht, wobei die Kugeln in zumindest einer Rille des Gewindeabschnitts geführt sind,

und wobei die zumindest eine Rille zu ihren beiden Enden jeweils Anschläge aufweist, die den Umfangsweg der Kugeln begrenzen.Generally, in principle, regardless of the specific embodiment of the brake actuation mechanism and the implemented therein Adjustment device, the gist of the present invention is to provide a brake actuation mechanism for a disc brake, comprising:

• a reinforcing mechanism for introducing a clamping force for the braking operation,
• a pressure element for transmitting the application force to a brake disk, the reinforcement mechanism and the pressure element cooperating in such a way that the pressure element performs a translatory movement in the direction of the brake disk by means of a displacement movement of the reinforcement mechanism,
• - And an adjusting device for compensating a lining wear, wherein an input element of the adjusting device is displaceable by this translational movement in rotation, which is formed as a spindle of a ball screw with a threaded portion which is connected via balls with a nut of the ball screw drive in a rotatable connection, wherein the balls are guided in at least one groove of the threaded portion,

and wherein the at least one groove has stoppers at both ends thereof defining the circumferential path of the balls.

Due to the fact that the two-sided ends of the grooves are provided with stops against which the balls, which may be arranged in a ball cage accumulate, the circumferential travel of the balls and thus the amount of possible rotation of the spindle is limited. In addition, this prevents in the assembled state that the balls can fall out of the grooves. Overall, the unit of nut and spindle can be better held together by the inventive measure in functional terms.

In a further development of the brake actuation mechanism a plurality of grooves are provided, each extending over only a partial circumference of the spindle and overlap each other over a certain extent.

By a selective selection of the extent of the overlap and the circumferential extent of the grooves, the rotational behavior of the hollow spindle in coordination with the other design specifications of the adjusting device and thereby their Nachstellverhalten be specifically determined.

In an analogous manner, the nut may have grooves in which the balls are guided. According to the invention, in this case the number, the pitch angle and / or the circumferential extent of the grooves of the nut and / or the grooves of the threaded portion can be configured differently.

In particular, the grooves of the nut and / or the grooves of the threaded portion may have a varying pitch.

In an advantageous embodiment of the brake actuating mechanism according to the invention, the grooves of the nut and the grooves of the threaded portion are configured such that a first adjustment at low rotational speeds of the spindle and a further, beyond adjustment at higher rotational speeds of the spindle is accomplished by the adjusting device.

The brake actuating mechanism according to an embodiment of the invention is designed so that the input element of the adjusting device interacts directly or indirectly with a torque clutch to realize a more compact structure, and further configured such that the reinforcing mechanism, the pressure element and the adjusting device by means of a in a Housing a brake caliper of the disc brake in the axial direction immovable and non-rotatably mounted rod are functionally cooperatively mounted in the caliper, wherein the input element of the adjusting device is designed as a rotatably mounted on the rod hollow spindle of a ball screw.

The advantage in the use of a ball screw is basically that inherent in such a mechanism basically less friction, along with a lower wear. The thus required lower drive power at the same time possible higher speeds of movement proves to be particularly advantageous for adjusting because they allow for a lower effort more accurate adjustment in the compensation of the wear-related clearance.

Since the ball screw converts a translational movement into a rotation, according to the invention, the movement of the pressure element directed forwardly onto the brake disk can be used in order to produce a rotation in the ball screw drive. Here, the low internal friction of a ball screw is advantageous because even the application of the spindle, which is used as an input element for the adjusting, with a linear pressure force to a rotation of the nut or spindle leads, depending on which of the elements against rotation within the Adjustment device is arranged.

This makes it possible according to the invention, the reinforcing mechanism, or the components of the reinforcing mechanism, on the adjusting device, or on the Input element of it, with brake application and if necessary act on brake release, mechanically decouple. Lack of direct mechanical connection via coupling elements, such as pins and recess in the prior art, such a brake actuation mechanism is exposed to less wear and has a longer life.

An essential advantage of the brake actuating mechanism according to the invention is that the ball screw of the adjusting device with regard to the desired Nachstellverhalten, taking into account the further embodiment of the adjusting device and the brake actuation mechanism, individually configure and vote individually, with a constructive targeted on the type the thread used, such as on the type of grooves and balls, the type of threads, etc. influence is taken.

The invention also relates to a disc brake having a brake actuation mechanism according to at least one of the above-described embodiments. In particular, the invention relates to a disc brake in which a brake actuation mechanism according to at least one of the above-described embodiments by a rod in a housing of a brake caliper of the disc brake is mounted at least in modules or in total as a self-supporting unit.

• 1 einen Längsschnitt in Axialrichtung eines Bremsbetätigungsmechanismus gemäß dem Stand der Technik;
• 2a eine Explosionsdarstellung dieses Bremsbetätigungsmechanismus in einer ersten Ansicht;
• 2b eine Explosionsdarstellung dieses Bremsbetätigungsmechanismus in einer weiteren Ansicht;
• 3 einen Längsschnitt in Axialrichtung durch eine Nachstelleinrichtung und Rückstelleinrichtung dieses Bremsbetätigungsmechanismus;
• 4 eine Explosionsdarstellung der Nachstelleinrichtung und Rückstelleinrichtung aus 3;
• 5 einen Längsschnitt in Axialrichtung durch einen Kugelgewindetrieb der Nachstelleinrichtung nach dem Stand der Technik;
• 6 eine alternative Ausführungsform der Gewindestruktur des Kugelgewindetriebs nach dem Stand der Technik; und
• 7 eine Ausführungsform der Gewindestruktur des Kugelgewindetriebs gemäß der Erfindung.

Further advantages and features of the invention will become apparent from the following description of the embodiments illustrated with reference to the drawings. Show it

• 1 a longitudinal section in the axial direction of a brake actuation mechanism according to the prior art;
• 2a an exploded view of this brake actuation mechanism in a first view;
• 2 B an exploded view of this brake actuation mechanism in another view;
• 3 a longitudinal section in the axial direction by an adjusting and restoring device of this brake actuation mechanism;
• 4 an exploded view of the adjusting and restoring 3 ;
• 5 a longitudinal section in the axial direction by a ball screw of the adjusting device according to the prior art;
• 6 an alternative embodiment of the threaded structure of the ball screw according to the prior art; and
• 7 an embodiment of the thread structure of the ball screw according to the invention.

The 1 to 6 generally show all components of a brake actuation mechanism according to the prior art, as exemplified in the Int. registration WO 2018/015565 A1 is described, the disclosure of which is hereby incorporated by reference.

Such a prior art brake actuating mechanism consists essentially of four modules which functionally cooperate, namely a reinforcing mechanism A, an adjuster B, a pressure element C and a return device D, the brake actuation mechanism acting as a self-supporting unit by means of a centrally located rod 1 can be mounted on this itself and thereby in a housing of the caliper.

The reinforcing mechanism A serves to introduce an actuating force from a hydraulic, pneumatic or electromechanical actuator (not shown) as a clamping force into the brake actuating mechanism and to reinforce it according to a gear ratio dictated by its construction. A lever 2 is pivotally mounted in a rear housing portion of a (also not shown here) caliper by this against a roller 3 is rotatably arranged, wherein the roller 3 relative to the axis of rotation of the lever 2 is positioned eccentrically. Between the roller 3 and the corresponding area of the lever 2 are needle roller bearings or needle roller cages 4 intended.

At the roller 3 opposite side is the lever 2 via corresponding needle roller bearings or needle bearing cages 5 in corresponding bearing surfaces of a one-piece bearing seat body 6 pivoted.

The reinforcing mechanism A is designed so that by rotation about the roller 3 the lever 2 this opposite performs an eccentric displacement movement, which leads to a corresponding increase in the lever 2 acting actuating force, which then as a clamping force via a translational movement of the bearing seat body 6 which may be linearly guided for this purpose in the housing of the caliper, is transmitted to the adjusting device B and the pressure element C.

The adjusting device B follows in the axial direction with respect to a (not shown here) Brake disc seen immediately after the bearing seat body 6 and has a ball screw 7 on how best he is from the 5 and 6 can be seen.

The ball screw 7 has a hollow spindle 8th on, inter alia, via a plain bearing bush 9 on the bar 1 is rotatably mounted.

The hollow spindle 8th is divided into a brake disc facing away, the bearing seat body 6 facing threaded portion 10 and a brake disk facing cylinder portion 11 ,

The threaded section 10 stands over balls 12 that in a double row Kugelkä 13 are stored, with a threaded portion 10 radially surrounding nut 14 in connection.

The threaded section 10 has corresponding grooves 15 and the mother 14 corresponding grooves 16 on, between which the two-row arranged balls 12 are guided.

The mother 14 forms the drive element of the ball screw 7 and is with the bearing seat body 6 non-rotatably connected by frontally to the mother 14 provided, extending in the axial direction projections 17 in corresponding recesses 18 of the bearing seat body 6 intervention.

This causes a translational movement of the bearing seat body upon initiation of the application force 6 and thus the mother 14 due to the kinematics of the ball screw 7 in a rotary motion of the hollow spindle 8th on the bar 1 results.

The hollow spindle 8th as output element of the ball screw 7 simultaneously forms the input element for the adjusting device B, as will be explained below.

On the hollow spindle 8th is in the area of the cylinder section 11 a coupling sleeve 19 arranged with the hollow spindle 8th is rotatably connected via an interference fit.

The coupling sleeve 19 has a circumferential flange ring 20 on, on which a spring 21 supported on the opposite side in a frontal recess 22 mother 14 is absorbed, so that the spring can not migrate radially.

The feather 21 is capable of the cones 17 in engagement with the recesses 18 to keep.

The coupling sleeve 19 is about a first freewheel spring 23 with a radial bearing hub 24 coupled. The coupling sleeve 19 and the radial bearing hub 24 close the first freewheel spring radially and thus form a first torque clutch M1.

The radial bearing hub 24 is about a radial bearing 25 with a front torque sleeve 26 in a torque transmitting connection. The radial bearing hub 24 has longitudinal grooves 27 and the front torque sleeve 26 has corresponding longitudinal grooves 28, between which the balls of the radial bearing 25 are stored, so that a torque transmission is provided with simultaneous axial displacement between these elements.

By forming a second torque clutch M2 is the front torque sleeve 26 via a second freewheel spring 29 with a rear torque sleeve 30 connected.

The rear torque sleeve 30 has radial projections 31 on that in corresponding recesses 32 an adjusting spindle 33 intervention. The adjusting spindle 33 encloses the other components of the adjuster B completely and has a thread on the outside 34 on, with an internal thread 35 a pot-like pressure piece 36 the pressure element C is in a threaded engagement. At the front of the pressure piece acts 36 with a (not shown here) brake pad holder together to transfer the clamping force to the brake disc.

The rear torque sleeve 30 is supported by a low-friction radial bearing 37 with the interposition of an intermediate ring 38 on the bearing seat body 6 from. The bearing seat body 6 again stands with the adjusting spindle 33 over a storage area 39 directly in contact (s. 2 B ), wherein radial sections, circumferential, axial projections 40 (S. 2a ) of the adjusting spindle 33 in an annular recess 41 of the bearing seat body 6 intervention. This ensures that the main force flow of the clamping force of the bearing seat body 6 directly into the adjusting spindle 33 and over the thread engagement 34 . 35 on the pressure piece 36 takes place while due to the low-friction radial bearing 37 the rear torque sleeve 30 and thus the adjuster B remains largely decoupled from the application force in the axial direction as far as possible.

At the radial bearing 37 opposite side is at the front torque sleeve 26 a sliding bearing ring 42 provided, which opposite a retaining ring 43 is guided.

On the retaining ring 43 comes a spring 44 the return device D to the plant. The spring designed as a helical spring 44 in turn relies on an abutment shell 45 starting at the brake disc facing the end of the Staff 1 by means of a fastening nut 46 is attached.

The abutment shell 45 This is between an abutment ring 47 and the fastening nut 46 clamped.

The hollow spindle 8th turn is on the abutment ring 47 via a retaining ring 48 and a thrust bearing 49 supported in a rotatable bearing, which is on the hollow spindle 8th absorb axially acting forces.

By forming a third torque clutch M3 is the abutment ring 47 via a third freewheel spring 50 with the radial bearing hub 24 coupled, which includes these components radially on the outside.

Like from the 1 It can be seen, the entire brake actuating mechanism is the brake disk side through the fastening nut 46 and brake disc facing away through a mounting ring 51 on the bar 1 held by the reinforcing mechanism A, the adjusting device B, the pressure element C and the return means D are arranged to functionally cooperate, wherein the hollow adjusting spindle 33 the remaining components of the adjusting device B and the restoring device D completely absorbs. The brake actuation mechanism can by means of the rod 1 mounted as a unit in a housing of the caliper and fastened. To seal against the housing of the caliper is a translational movement of the pressure element C axially rolling sealing sleeve 52 between the pressure piece 36 and the inner wall of a housing of the caliper provided.

During a brake operation, when a translational movement of the bearing seat body 6 the hollow spindle 8th over the ball screw 7 set in rotation, locks the first freewheel spring 23 the first torque clutch M1, the coupling sleeve 19 with the radial bearing hub 24 , About the radial bearing 25 then the rotation corresponding to the front torque sleeve 26 transfer.

During brake release, ie when no more clamping force is transmitted, the spring causes 21 that the mother 14 the backward movement of the bearing seat body 6 follows. This is the hollow spindle 8th turned back to its original position.

In the 6 is an embodiment of a hollow spindle 8th shown in the prior art.

This hollow spindle 8th has in the region of its threaded portion 10 a plurality of grooves 53 on, each only over a partial circumference of the hollow spindle 8th extend and overlap each other to some extent. At one end of the grooves 53 are stops 54 provided against which the balls 55 in a single-row Kugelkä 56 are arranged, accumulate.

In the 7 is an embodiment of a hollow spindle 8th shown according to the invention, a further development of the hollow spindle 8th out 6 concerns.

In this are at both ends of the grooves 53 each attacks 54 provided to the circumferential path of the balls 55 to limit in both directions of rotation and, moreover, to prevent the bullets 55 In particular, they should not be in any ball k 56 be stored, out of the grooves 53 fall out.

As a result, the circumferential path of the balls 55 and thus the degree of possible rotation of the hollow spindle 8th limited. By a selective selection of the extent of overlap and the circumferential extent of the grooves 53 can the rotational behavior of the hollow spindle 8th in coordination with the other design specifications of the adjusting device B and thereby their Nachstellverhalten be specifically determined.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2011/113554 A2 [0004, 0006]
• WO 2013/083857 A2 [0006]
• WO 2014/106672 A2 [0006]
• WO 2015/140225 A2 [0006]
• WO 2018/015565 A1 [0009, 0026]

Claims (9)

A brake actuation mechanism for a disc brake, comprising - a reinforcing mechanism (A) for applying a brake application force, - a pressure element (C) for transmitting the application force to a brake disc, wherein the amplification mechanism (A) and the pressure element (C) cooperate such that the Pressure element (C) by a displacement movement of the reinforcing mechanism (A) performs a translational movement in the direction of the brake disc, - and an adjusting device (B) to compensate for pad wear, wherein an input element of the adjusting device (B) is set in rotation by this translational movement, the is formed as a spindle (8) of a ball screw (7) with a threaded portion (10) which is connected via balls (12) with a nut (14) of the ball screw drive (7) in a rotatable connection, wherein the balls (12) in at least a groove (15; 53) of the threaded portion (10) are guided, characterized in that the at least one groove (15; 53) has stoppers (54) at its two ends which delimit the circumferential path of the balls (12). Bremsbetätigungsmechanismus after Claim 1 in which a plurality of grooves (15; 53) are provided, each of which extends over only a partial circumference of the spindle (8) and overlap one another over a certain circumference. Bremsbetätigungsmechanismus after Claim 1 or 2 in which the nut (14) has grooves (16) in which the balls (12) are guided, and in which the number, the pitch angle and / or the circumferential extent of the grooves (16) of the nut (14) and / or the grooves (15; 53) of the threaded portion (10) are configured differently. Bremsbetätigungsmechanismus after Claim 3 in that the grooves (16) of the nut (14) and / or the grooves (15; 53) of the threaded portion (10) have a varying pitch. Bremsbetätigungsmechanismus after Claim 3 or 4 in that the grooves (16) of the nut (14) and the grooves (15; 53) of the threaded portion (10) are designed such that a first adjustment at low rotational speeds of the spindle (8) and a further, moreover adjustment at higher rotational speeds of the spindle (8) by the adjusting device (B) is accomplished. Brake actuation mechanism according to one of Claims 1 to 5 in which the input element of the adjusting device (B) interacts directly or indirectly with a torque clutch (M1). Bremsbetätigungsmechanismus after Claim 6 in that the reinforcing mechanism (A), the pressure element (C) and the adjusting device (B) are functionally cooperatively mounted in the caliper by means of a rod immovably and non-rotatably mounted in a housing of a brake caliper of the disc brake Input element of the adjusting device (B) as a on the rod (1) rotatably mounted hollow spindle (8) of a ball screw (7) is formed. Disc brake having a brake actuation mechanism according to at least one of Claims 1 to 7 , Disc brake after Claim 8 in which the brake actuating mechanism according to at least one of Claims 1 to 7 by a rod (1) in a housing of a caliper of the disc brake is mountable as a self-supporting unit.

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