DE102022203672A1 - Drum brake for a vehicle - Google Patents

Abstract

The invention relates to a drum brake (2) for a vehicle, with at least one brake drum (6) mounted rotatably about an axis of rotation (4), with at least one non-rotatable brake carrier (8), with at least one brake medium holder (10) arranged within the brake drum (6). ), which is movably fixed to the brake carrier (8), with at least one braking means (12) which is fixed to the brake medium holder (10) on the side of the brake medium holder (10) facing the brake drum (6) and which has a braking surface (16) comprehensive friction layer (14), with at least one actuating unit (18), which is fixed in a rotationally fixed manner on the brake carrier (8) and through which the brake medium holder (10) is moved from an unactuated basic position in which the braking surface (16) of the brake medium (12) is Brake drum (6) is spaced apart, can be moved into a braking position in which the braking surface (16) of the friction layer (14) rests in contact with the brake drum (6) and causes wear, and with at least one magnet unit (20), which has at least one magnetic means (22), which is fixed on a side of the actuating unit (18) facing the brake drum (6), which is spaced from the brake drum (6) when the vehicle is braked and through which magnetic or magnetizable brake abrasion, in particular from the friction layer (14) of the braking means (12) and/or the brake drum (6) can be magnetically attracted.

Description

The invention relates to a drum brake for a vehicle.

When operating a motor vehicle, in particular when braking the motor vehicle, a braking means is moved towards the brake drum. Here, the braking agent rests on the brake drum with a friction layer comprising a braking surface.

Due to the prevailing friction between the brake medium and the brake drum, it can never be completely avoided that particles come off from the friction layer of the brake medium or from the inner surface of the brake drum during braking. These brake particles can end up in the environment.

In the known drum brakes, at least the braking means, in particular the friction layer of the braking means, consists of a gray cast iron or a coated brake shoe. In this case, the abrasion generated during braking contains braking particles that are metallic. These can cause damage to the lungs and the human body.

One object of an exemplary embodiment of the invention is to propose a drum brake for a vehicle in which the number of brake particles released into the environment is at least reduced.

This object is achieved by a drum brake for a vehicle, with at least one brake drum rotatably mounted about an axis of rotation, with at least one non-rotatable brake carrier, with at least one brake medium holder arranged within the brake drum, which is movably fixed to the brake carrier, with at least one brake medium that is on the side of the brake medium holder facing the brake drum is fixed to the brake medium holder and which has a friction layer comprising a braking surface, with at least one actuating unit which is fixed in a rotationally fixed manner on the brake carrier and through which the brake medium holder is spaced from an unactuated basic position in which the braking surface of the brake medium is spaced from the brake drum is, can be transferred to a braking position in which the braking surface of the friction layer is in contact with the brake drum and produces wear, and with at least one magnetic unit, which comprises at least one magnetic means which is fixed on a side of the actuating unit facing the brake drum, which occurs during braking of the vehicle is spaced from the brake drum and through which magnetic or magnetizable brake abrasion, in particular from the friction layer of the brake medium and / or from the brake drum, can be magnetically attracted.

Because the drum brake comprises a magnetic unit which comprises at least one magnetic means which is fixed on a side of the actuating unit facing the brake drum, which is spaced from the brake drum when the vehicle is braked and through which magnetic or magnetizable brake abrasion can be magnetically attracted, the number of brake abrasion that can be released into the environment as a result of a braking process.

The braking means can be brake shoes and the friction layer can be a brake pad.

The actuating unit can basically have any technical design, provided that it can transfer the brake medium holder with brake means arranged on it from the unactuated basic position into the braking position. In such a case, the actuating unit can comprise a mechanical, electrical, pneumatic and/or hydraulic drive or actuator.

It proves to be advantageous if the actuating unit comprises at least one first brake cylinder, through which at least one, in particular at least two, brake medium holders can be moved from the basic position to the braking position and/or if the actuating unit comprises at least one clamping means through which the at least one brake medium holder can be preloaded into the unactuated basic position.

Because the actuating unit includes a brake cylinder, the brake medium holder can be easily transferred from the basic position to the braking position. Because the actuating unit comprises at least one clamping device, through which the at least one brake medium holder can be pretensioned into the unactuated basic position, the brake medium holder is automatically returned to the unactuated basic position when the braking process has ended.

Embodiments of the drum brake are conceivable in which the actuating unit comprises at least one bearing means which is arranged on the side of the brake medium holder facing away from the first brake cylinder and through which the at least one brake medium holder can be rotated about an axis of rotation, the brake medium holder being transferred from the basic position to the braking position comprises a rotational movement or in which the actuating unit comprises at least one second brake cylinder which is arranged on the side of the brake medium holder facing away from the first brake cylinder, wherein the brake medium holder comprises a translational movement when transferred from the basic position to the braking position.

If the actuating unit comprises at least one bearing means which is arranged on the side of the brake cylinder facing away from the first brake cylinder and through which the at least one brake cylinder can be rotated about an axis of rotation, the actuating unit can be manufactured simply and inexpensively.

If the actuating unit comprises at least two brake cylinders that are arranged at both ends of the brake medium holder, higher braking forces can be exerted.

In addition, it is conceivable that a brake cylinder of an actuating unit transfers two brake medium holders from the unactuated basic position into the braking position when actuated. In this case, both brake medium holders can be connected to a common brake cylinder on the same side and can each be rotated about their own bearing means on the side facing away from the brake cylinder. If the actuating unit comprises two brake cylinders, these can be arranged at opposite ends of the brake medium holders and can also control two brake medium holders.

The bearing means can basically be of any design, provided that it fulfills the technical function of rotating the brake medium holder about an axis of rotation when the brake cylinder is actuated. In such a case, embodiments are conceivable in which the bearing means comprises a bearing pin fixed to the brake carrier or a rod element which is rotatably fixed to a first brake medium holder and rotatably fixed to a second brake medium holder.

If the bearing means comprises a bearing pin fixed to the brake carrier, the brake medium holder is only coupled to the brake cylinder and the bearing pin.

If the bearing means comprises a rod element which is rotatably fixed to a first brake medium holder and rotatably fixed to a second brake medium holder, the two brake medium holders are coupled to one another in their kinematics via the rod element.

It proves to be advantageous if at least one of the at least one magnetic means of the magnetic unit comprises a magnetic body comprising a three-dimensional shape, a substantially planar magnetic film, a substantially planar magnetic tape or a magnetic coating, such as magnetic paint.

If the at least one magnetic means comprises a three-dimensional magnetic body, this can ensure increased magnetic forces. In addition, the external surface on which the magnetic braking particles can rest is increased.

If at least one of the at least one magnetic body comprises a flat magnetic film, a substantially flat magnetic tape or a magnetic coating, at least one of the at least one magnetic means can be designed to have a reduced volume.

The at least one magnetic means can comprise a neodymium magnet, a hard ferrite magnet or an electromagnet.

In addition, embodiments of the drum brake are conceivable in which at least one of the at least one magnetic means comprises a recess that recesses in the direction of the actuating unit on the side facing the brake drum. This further increases the surface area of the magnetic means and creates a storage space into which magnetic particles can be displaced.

In addition, when developing the drum brake, it is provided that at least one of the at least one magnetic means is fixed directly on the actuating unit or that the magnet unit comprises at least one magnet holder which can be fixed or fixed on the actuating unit and on which the at least one magnetic means can be fixed or fixed .

If the magnetic means is fixed directly to the actuating unit, the magnetic means and the actuating unit can form a pre-assembly assembly. If the magnet unit includes a magnet holder, the drum brake can be easily retrofitted. In addition, the provision of a magnet holder makes it easier to arrange the magnetic means, since this can be fixed independently of the geometry of the actuating unit.

If a magnet holder is provided, the magnet unit can comprise two magnet means, with one magnet means being arranged on one side of the magnet holder.

In this case, magnetic brake particles can also be attracted by the magnet unit, which have flowed past unattracted on the side facing the brake drum and are attracted and held by the magnetic means at the rear area.

In order to further increase the number of magnetic brake particles that are attracted by the magnet unit, it proves to be advantageous if the magnet unit has at least one Deflection means comprises, which can be fixed to the actuating unit or to the magnet holder, which is spaced from the brake drum when the vehicle is braked, which surrounds the at least one magnetic means in an arc shape on the side of the magnetic means facing the direction of rotation and through which magnetic brake abrasion passes through the magnetic means unattracted can be redirected in the direction of the magnetic means with regard to its movement vector.

In order to make the drum brake compact, it proves to be advantageous in a further development of the latter embodiment if the deflection means and the magnet holder form a common, one-piece component.

Over the life cycle of a drum brake, the at least one magnetic element of the magnetic unit becomes increasingly clogged with magnetic brake dust. In this case, a gap existing between the magnetic means and the brake drum is increasingly reduced.

In order to continue to stock the brake output that has been attracted and stored, it proves to be advantageous if the magnet unit comprises a material-free storage section which is arranged between the deflection means and the magnet holder. In such a case, brake abrasion can be stored there or displaced there if a gap between the magnetic means and the brake drum is blocked.

When arranging the magnetic unit, in particular the at least one magnetic means on the actuating unit, the magnetic unit is spaced from the location where brake abrasion occurs, namely between the brake medium holder and the brake drum. Due to the rotating drive of the brake drum when the vehicle is in operation, air flows and turbulences occur within the drum brake. This allows the magnetic particles to be swirled without being deflected towards the magnet unit. In order to attract and store the number of magnetic or magnetizable particles of brake abrasion through the magnet unit, it proves to be advantageous if the drum brake comprises at least one guide means which can be fixed to the brake medium holder, which is spaced apart from the brake drum in the braking position of the brake medium holder and through that magnetic brake abrasion can be guided or steered in the direction of the magnetic means with regard to its movement vector.

It proves to be advantageous if the magnet holder is designed to be flat and comprises a flat or curved surface, with the surface of the magnet holder being inclined to the outer contour of the actuating unit or with an inclination between the surface of the magnet holder and the outer contour of the actuating unit being adjustable and/or if that Conducting means is flat and comprises a flat or curved surface, wherein the surface of the conducting means is inclined to the outer contour of the braking means holder and/or wherein an inclination between the surface of the conducting means and the outer contour of the braking means holder is adjustable.

If the magnet holder is flat and includes a flat or curved surface and is adjustable relative to the surface to the actuating unit or an inclination, a gap between the magnetic means and the brake drum can be made as small as possible and the number of brake particles attracted by the magnetic means can be increased.

If the guide means is designed to be flat and includes a flat or curved surface and is inclined to the brake medium holder or an inclination between the guide means and the outer contour of the brake medium holder can be adjusted, a flow that builds up within the drum brake can be adjusted in such a way that it flows past the magnet unit in an improved manner.

When developing the drum brake, it is provided that the magnet holder continues the outer contour of the actuating unit with a step or continuously and/or with a joint or seamlessly and/or that the guide means the outer contour of the brake medium holder with a step or continuously and/or with a joint or continues seamlessly.

In order to further improve the redirection or directing of the flow that carries the brake particles, it proves to be advantageous if the guide means and the inner surface of the brake drum form a nozzle-like cross section through which the magnetic brake particles flow, in particular a conical nozzle Form a diffuser or a Venturi nozzle.

If the guide means and the inner surface of the brake drum form a nozzle-like cross section, the flow behavior of the drum brake can be improved. Here circulating and/or flowing particles can be directed towards magnetic means for collection.

In addition, in embodiments of the drum brake it is provided that at least one of the at least one magnetic means is releasable, in particular positively or non-positively, in particular by means of screwing, clipping or clamping, or non-detachable, in particular by material, positive and/or non-positive fit, in particular by means of gluing. Riveting, soldering or welding, it is specified on the actuating unit or on the magnet holder that min at least one of the at least one magnet holder releasable, in particular positively or non-positively, in particular by means of screwing, clipping or clamping, or non-detachable, in particular materially, positively and/or non-positively, in particular by means of gluing, riveting, soldering or welding, on, on the Actuating unit is fixed and / or that at least one of the at least one guide means is releasable, in particular positively or non-positively, in particular by means of screwing, clipping or clamping, or non-detachable, in particular materially, positively and / or non-positively, in particular by means of gluing, riveting, soldering or welding, to which the brake fluid holder is fixed.

Finally, it proves to be advantageous if the at least one magnet holder and/or the deflection means comprise a magnetic or magnetizable material, in particular a metal, or a non-magnetic material, in particular a plastic, and/or if the guide means comprises a non-magnetizable material , especially a plastic.

If the magnet holder and/or deflection means comprises a magnetic or magnetizable material, this also becomes at least partially magnetic by arranging the magnetic means of the magnet unit. In such a case, the magnet holder and/or the deflection means also serves to store attracted brake particles. Because the conductive agent comprises a non-magnetic material, it can be avoided that the conductive agent is contaminated with braking particles.

Further features, details and advantages of the invention result from the attached patent claims, from the graphic representation and subsequent description of two preferred embodiments of the drum brake.

• 1 Eine Schnittansicht auf ein erstes Ausführungsbeispiel der Trommelbremse;
• 2 Eine Detailansicht des Ausführungsbeispiels gemäß 1;
• 3 Eine Detailansicht eines zweiten Ausführungsbeispiels der Trommelbremse.

In the drawing shows:

• 1 A sectional view of a first embodiment of the drum brake;
• 2 A detailed view of the exemplary embodiment according to 1 ;
• 3 A detailed view of a second embodiment of the drum brake.

The figures show two exemplary embodiments of a drum brake for a vehicle, provided overall with the reference number 2. This includes a brake drum 6 which is rotatably mounted about an axis of rotation 4.

The drum brake 2 comprises a rotationally fixed brake carrier 8 and a brake medium holder 10 which is movably fixed within the brake drum 6 on the brake carrier 8. In the exemplary embodiments shown in the figures, the drum brake 2 each comprises two brake medium holders 10, which are arranged mirror-symmetrically to one another.

Braking means 12 are arranged on the brake medium holders 10 and are fixed on the side of the respective brake medium holder 10 facing the brake drum 6. The braking means 12 include a friction layer 14, which includes a braking surface 16 on the side facing the brake drum 6.

In addition, the drum brake 2 comprises an actuating unit 18, which is fixed in a rotationally fixed manner on the brake carrier 8 and through which, in the exemplary embodiments shown in the figures, both brake medium holders 10 are moved from an unactuated basic position in which the braking surface 16 of the brake medium 12 is spaced from the brake drum 6 a braking position can be transferred in which the braking surface 16 of the friction layer 14 is in contact with the brake drum 6 and causes wear.

When braking, i.e. when transferring the brake medium holder 10 into the braking position, brake abrasion occurs due to friction. This can be magnetic or magnetizable. In order to prevent it from reaching the environment or at least to reduce the number of brake particles that are released into the environment, the drum brake includes a magnet unit 20, which includes at least one magnet means 22. In the exemplary embodiments shown in the figures, the magnetic means 22 is fixed on a side of the actuating unit 18 facing the brake drum 6. Here, the magnetic means 22 is designed such that it is spaced from the brake drum 6 when the vehicle is braked.

Due to the at least one magnetic means 22 of the magnet unit 20, magnetic brake abrasion, in particular from the friction layer 14 of the brake means 12 and/or from the brake drum 6, can be magnetically attracted.

In the exemplary embodiments shown in the figures, the magnet unit 20 comprises a magnet holder 24 to which the magnet means 22 is fixed.

The exemplary embodiment according to 1 and 2 differs from the exemplary embodiment 3 in that the magnet unit 20 of the exemplary embodiment according to 3 a deflection means 26 comprises that surrounds the at least one magnetic means 22 in an arc shape on the side of the magnetic means 22 facing the direction of rotation and through which magnetic brake abrasion that has passed through the magnetic means 22 without being attracted is referred to Lich its movement vector can be redirected in the direction of magnetic means 22.

In the exemplary embodiment according to 3 include deflection means 26 and magnet holder 24 a common one-piece component.

In the exemplary embodiments shown in the figures, the brake medium holders 10 can be moved from the unactuated basic position into the braking position by an actuating unit 18 formed by a brake cylinder 28. The brake cylinder 28 transfers both brake medium holders 10 from the unactuated basic position into the braking position.

On the side facing away from the brake cylinder 28, the actuating unit 18 includes bearing means 30, through which the respective brake medium holder 10 can be rotated from the unactuated basic position into the braking position by rotation about an axis of rotation 32. The bearing means 30 include bearing pins 34. The two exemplary embodiments according to 1 and 2 on the one hand and 3 on the other hand, include a guide means 36, which is fixed to a brake means holder 10, which is spaced from the brake drum 6 in the braking position of the brake means holder 10 and through which magnetic brake abrasion can be guided or steered in the direction of the magnetic means 22 with respect to its movement vector.

The guide means 36 includes a curved surface. This curved surface narrows a distance between the guide means 36 and the brake drum 6 down to a narrowest cross section and then widens again.

Both guide means 36 and magnet holder 24 are each detachably or non-detachably attached to the brake medium holder 10 or to the actuating unit 18.

• Beim Überführen der Bremsmittelhalter 10 von einer unbetätigten Grundstellung in eine Bremsstellung, wird das Bremsmittel 12 mit seiner die Bremsfläche 16 umfassenden Reibschicht 14 berührend an der Bremstrommel 6 angelegt. Hierdurch entsteht Abrieb.

The following briefly describes how the drum brake 2 works:

• When the brake medium holder 10 is transferred from an unactuated basic position to a braking position, the braking medium 12 is placed in contact with the brake drum 6 with its friction layer 14 encompassing the braking surface 16. This causes abrasion.

This abrasion can include magnetic or magnetizable particles that are entrained by the flow present within the drum brake 2. By passing through the guide means 36, the particles are deflected in the direction of the at least one magnetic means 22 of the magnet unit 20. As a result, they adhere to the magnetic means 22 and are stored there. In order to further increase this effect, in the exemplary embodiment 3 the magnet holder 24 is designed as a deflection means 26 in order to deflect the magnetic or magnetizable brake abrasion that has flowed past the magnet means 22 back and return it to the magnet means 22.

The features of the invention disclosed in the above description, in the claims and in the drawing may be essential both individually and in any combination in the implementation of the invention in its various embodiments within the scope of the following claims.

Reference symbol list

2

drum brake

4

Axis of rotation

6

brake drum

8th

Brake carrier

10

Brake fluid holder

12

braking agent

14

friction layer

16

braking surface

18

Actuator unit

20

Magnet unit

22

Magnetic means

24

Magnetic holder

26

Deflection means

28

Brake cylinder

30

storage means

32

Axis of rotation

34

bearing journal

36

Conducting means

Claims (15)

Drum brake (2) for a vehicle, with at least one brake drum (6) rotatably mounted about an axis of rotation (4), with at least one non-rotatable brake carrier (8), with at least one brake medium holder (10) arranged within the brake drum (6), which is on Brake carrier (8) is movably fixed, with at least one braking means (12), which is fixed to the brake medium holder (10) on the side of the brake medium holder (10) facing the brake drum (6) and which has a friction layer (14) comprising a braking surface (16). ). beab is stationary, can be moved into a braking position in which the braking surface (16) of the friction layer (14) rests in contact with the brake drum (6) and produces wear, and with at least one magnet unit (20) which comprises at least one magnet means (22). , which is fixed on a side of the actuating unit (18) facing the brake drum (6), which is spaced from the brake drum (6) when the vehicle is braked and through which magnetic or magnetizable brake abrasion can be magnetically attracted. Drum brake (2). Claim 1 , characterized in that the actuating unit (18) comprises at least one first brake cylinder (28), through which at least one, in particular at least two, brake medium holders (10) can be moved from the basic position to the braking position and / or that the actuating unit (18) at least comprises a clamping means through which the at least one brake medium holder (10) can be pretensioned into the unactuated basic position. Drum brake (2). Claim 1 or 2 , characterized in that the actuating unit (18) comprises at least one bearing means (30) which is arranged on the side of the brake medium holder (10) facing away from the first brake cylinder (28) and through which the at least one brake medium holder (10) rotates about an axis of rotation ( 32) is rotatable, wherein the brake medium holder (10) comprises a rotational movement when transferring from the basic position to the braking position or that the actuating unit (18) comprises at least one second brake cylinder (28) which is located on the side of the brake cylinder (28) facing away from the first brake cylinder (28). Brake medium holder (10) is arranged, wherein the brake medium holder (10) comprises a translational movement when transferred from the basic position to the braking position. Drum brake (2). Claim 3 , characterized in that the bearing means (30) comprises a bearing pin (34) fixed to the brake carrier (8) or a rod element which is rotatably fixed to a first brake means holder (10) and rotatably to a second brake means holder (10). Drum brake (2) according to one of the preceding claims, characterized in that at least one of the at least one magnetic means (22) of the magnet unit (20) has a magnetic body comprising a three-dimensional shape, a substantially flat magnetic film, a substantially flat magnetic tape or a magnetic coating , such as magnetic painting. Drum brake (2) according to one of the preceding claims, characterized in that at least one of the at least one magnet means (22) is fixed directly to the actuating unit (18) or that the magnet unit (20) comprises at least one magnet holder (24) which is attached to the Actuating unit (18) can be fixed or fixed and on which the at least one magnetic means (22) can be fixed or fixed. Drum brake (2) according to one of the preceding claims, characterized in that the magnet unit (20) comprises at least one deflection means (26) which can be fixed to the actuating unit (18) or to the magnet holder (24), which is used when the vehicle is braked Brake drum (6) is spaced apart, which surrounds the at least one magnetic means (22) in an arc shape on the side of the magnetic means (22) facing the direction of rotation and through which magnetic brake abrasion, which has passed through the magnetic means (22) unattracted, with respect to its movement vector in the direction of the magnetic means (22) can be diverted. Drum brake (2). Claim 7 , characterized in that the deflection means (26) and the magnet holder (24) form a common one-piece component. Drum brake (2) according to one of the Claims 6 until 8th , characterized in that the magnet unit (20) comprises a material-free storage section which is arranged between the deflection means (26) and the magnet holder (24). Drum brake (2) according to one of the preceding claims, characterized by at least one guide means (36) which can be fixed to the brake medium holder (10), which is spaced from the brake drum (6) in the braking position of the brake medium holder (10) and through which magnetic brake abrasion is prevented its movement vector can be guided or steered in the direction of the magnetic means (22). Drum brake (2) according to one of the Claims 6 until 10 , characterized in that the magnet holder (24) is flat and comprises a flat or curved surface, with the surface of the magnet holder (24) being inclined to the outer contour of the actuating unit (18) or with an inclination between the surface of the magnet holder (24) and Outer contour of the actuating unit (18) is adjustable and/or that the guide means (36) is flat and comprises a flat or curved surface, wherein the surface of the guide means (36) is inclined to the outer contour of the brake means holder (10) and/or wherein a Inclination between the surface of the guide means (36) and the outer contour of the brake medium holder (10) is adjustable. Drum brake (2) according to one of the Claims 6 until 11 , characterized in that the magnet holder (24) continues the outer contour of the actuating unit (18) with a step or continuously and / or with a joint or seamlessly and / or that the guide means (36) the outer contour of the brake medium holder (10) with a step or continues continuously and/or with a joint or seamlessly. Drum brake (2) according to one of the Claims 10 until 12 , characterized in that the guide means (36) and the inner surface of the brake drum (6) form a nozzle-like cross section through which the magnetic brake particles flow, in particular forming a conical nozzle, a diffuser or a Venturi nozzle. Drum brake (2) according to one of the preceding claims, characterized in that at least one of the at least one magnetic means (22) is releasable, in particular positively or non-positively, in particular by means of screwing, clipping or clamping, or non-detachable, in particular material, form and/or or it is fixed non-positively, in particular by means of gluing, riveting, soldering or welding, to the actuating unit (18) or to the magnet holder (24), so that at least one of the at least one magnet holder (24) is releasable, in particular positively or non-positively, in particular by means of a screw connection, Clipping or clamping, or non-detachable, in particular materially, positively and/or non-positively, in particular by means of gluing, riveting, soldering or welding, is fixed to the actuating unit (18) and/or that at least one of the at least one conductive means (36 ) releasably, in particular positively or non-positively, in particular by means of screwing, clipping or clamping, or non-detachable, in particular materially, positively and/or non-positively, in particular by means of gluing, riveting, soldering or welding, to the brake medium holder (10). Drum brake (2) according to one of the Claims 6 until 14 , characterized in that the at least one magnet holder (24) and/or the deflection means (26) comprise a magnetic or magnetizable material, in particular a metal, or a non-magnetic material, in particular a plastic, and/or that the conductive means (36 ) comprises a non-magnetizable material, in particular a plastic.

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