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DE-102024133160-A1 - Vehicle drum brake, especially for commercial vehicles

DE102024133160A1DE 102024133160 A1DE102024133160 A1DE 102024133160A1DE-102024133160-A1

Abstract

The invention relates to a vehicle drum brake (1), in particular for commercial vehicles, comprising a brake carrier (5), a drum (3) rotatable relative to the brake carrier (5) about a drum axis (X) with a circumferentially formed inner friction surface (21), wherein the brake carrier (5) and the drum (3) define a drum housing (14), a brake lining assembly (7) with several radially movable lining carriers (11), on each of which a brake lining segment (9) is provided facing the friction surface (21), wherein the drum (3) and the brake lining assembly (7) are arranged on a first side (2) on the brake carrier (5), and the drum brake (1) has a service brake device (32) and a parking brake device (29) for actuating the brake lining assembly (7). It is proposed that the drum brake (1) is characterized in that the drum brake (1) has an actuator (23) with an actuator housing (22) which is arranged on the brake carrier (5) on a second side (8) opposite the first side (2), wherein the actuator housing (22) has the parking brake device (29).

Inventors

  • Artem Grig

Assignees

  • ZF CV SYSTEMS EUROPE BV

Dates

Publication Date
20260513
Application Date
20241113

Claims (20)

  1. Vehicle drum brake (1), in particular for commercial vehicles, comprising a brake carrier (5), a drum (3) rotatable relative to the brake carrier (5) about a drum axis (X) with a circumferentially formed inner friction surface (21), wherein the brake carrier (5) and the drum (3) define a drum housing (14), a brake lining assembly (7) with several radially movable lining carriers (11), on each of which a brake lining segment (9) is provided facing the friction surface (21), wherein the drum (3) and the brake lining assembly (7) are arranged on a first side (2) on the brake carrier (5), and the drum brake (1) has a service brake device (32) and a parking brake device (29) for actuating the brake lining assembly (7), characterized in that the drum brake (1) has an actuator (23) with an actuator housing (22), which is attached to the second side (8) opposite the first side (2). brake carrier (5) is arranged, wherein the actuator housing (22) has the parking brake device (29).
  2. Vehicle drum brake (1) according Claim 1 , characterized in that the actuator housing (22) has an annular space (25) which has a service brake chamber (27), wherein the parking brake device (29) is arranged within the service brake chamber (27).
  3. Vehicle drum brake (1) according Claim 1 or 2 , characterized in that the brake carrier (5) has a flange section (5a), wherein the actuator housing (22) is mounted on the brake carrier (5) on a side of the flange section (5a) facing away from the drum (3).
  4. Vehicle drum brake (1) according to one of the preceding claims, characterized in that the service brake chamber (27) has one or more service brake pistons (30) with a piston rod (31) which is arranged to extend from the actuator housing (22), preferably from the service brake chamber (27), into the drum housing (14) and is operatively connected with the brake lining assembly (7).
  5. Vehicle drum brake (1) according Claim 4 , characterized in that the parking brake device (29) has a locking ring (37), wherein the locking ring (37) is arranged axially displaceably on the service brake piston (30), preferably on the piston rods (31), wherein the locking ring (37) is rotatably driven.
  6. Vehicle drum brake according to Claim 5 , characterized in that the locking ring (37) is arranged to be rotated back and forth between a locking position (V) and a release position (F), wherein the locking ring (37) engages positively in the brake carrier (5) in the locking position (V) and is axially movable through the brake carrier (5) in the release position (F).
  7. Vehicle drum brake according to Claim 6 , characterized in that the locking ring (37) has a ring body (53) and one or more webs (46) projecting axially from the ring body (53) in the direction of the brake carrier (5), and the brake carrier (5) has one or more through-openings (45) corresponding to the webs (46), wherein the webs (46) extend through the through-openings (45) and are configured to lock the brake pad assembly (7) in the locking position (V).
  8. Vehicle drum brake (1) according Claim 7 , characterized in that a wedge carrier (13) is arranged in the drum housing (14) on the first side of the brake carrier (5), which is arranged to be displaceable along the drum axis (X) in a clamping direction and in a clamping direction, wherein the wedge carrier (13) engages directly or indirectly with the webs (46), wherein the webs (46) in the locking position (V) block the movement of the wedge carrier (13) in the clamping direction.
  9. Vehicle drum brake (1) according to one of the Claims 6 until 8 , characterized in that the locking ring (37) has a bayonet section (50) which is designed to engage positively with the brake carrier (5) in the locking position (V), preferably with an edge section of the through opening (45) receiving the respective web (46), wherein the bayonet section (50) is preferably formed by a number of circumferentially oriented recesses (51) formed on the webs (46).
  10. Vehicle drum brake (1) according to one of the preceding claims, characterized in that the locking ring (37) is coupled to a drive ring (43), wherein the drive ring (43) is arranged on the locking ring (37) in a rotationally fixed and axially sliding manner, wherein the drive ring (43) is operatively connected to a parking brake actuator (39).
  11. Vehicle drum brake (1) according Claim 4 , characterized in that the parking brake device (29) has a rotatably driven threaded sleeve (57) and a threaded ring (59) connected to the threaded sleeve (57), which is designed to be rotationally fixed and axially movable back and forth between a release position (F) and a locking position (V), and which is designed to bear against the service brake piston (30) in the locking position (V) and to block the actuation of the service brake piston (30) in the clamping direction.
  12. Vehicle drum brake (1) according Claim 11 , characterized in that the service brake piston (30) divides the service brake chamber (27) into a service brake pressure chamber (26) and a service brake working chamber (28), wherein the threaded sleeve (57) and the threaded ring (59) are arranged in the service brake pressure chamber (26).
  13. Vehicle drum brake (1) according to one of the Claims 1 until 4 , characterized in that a wedge carrier (13) is arranged in the drum housing (14) on the first side (2) of the brake carrier (5), which is displaceably arranged along the drum axis (X) in a clamping direction and in a clamping direction, and the parking brake device (29) has a rotatably driven threaded sleeve (61) which is arranged in a thread (63) of the brake carrier (5) and is configured to be moved axially back and forth between a release position (F) and a locking position (V), wherein the threaded sleeve (61) is configured to bear against the wedge carrier (13) in the locking position (V) and to block the movement of the wedge carrier (13) in the clamping direction.
  14. Vehicle drum brake (1) according Claim 13 , characterized in that the piston rod (31) of the service brake piston (30) is inserted through the threaded sleeve (61) into the drum housing (14).
  15. Vehicle drum brake (1) according Claim 13 or 14 , characterized in that the service brake piston (30) divides the service brake chamber (27) into a service brake pressure chamber (26) and a service brake working chamber (28), wherein the threaded sleeve (61) is arranged in the service brake working chamber (28).
  16. Vehicle drum brake (1) according Claim 4 , characterized in that the parking brake device (29) has a rotatably driven threaded insert (67) which is arranged in a thread (69) of the actuator housing (22) and is designed to be moved axially back and forth between a release position (F) and a locking position (V) in order to bear against the service brake piston (30) in the locking position (V) and to block the actuation of the service brake piston (30) in the clamping direction.
  17. Vehicle drum brake (1) according Claim 16 , characterized in that the service brake piston (30) divides the service brake chamber (27) into a service brake pressure chamber (26) and a service brake working chamber (28), wherein the threaded insert (67) extends into the service brake pressure chamber (26).
  18. Vehicle drum brake (1) according Claim 4 , characterized in that a wedge carrier (13) is arranged in the drum housing (14) on the first side (2) of the brake carrier (5), which is slidably arranged along the drum axis (X) in a clamping direction and in a clamping direction, and the piston rod (31) has a first rod part (73) facing away from the drum housing (14) and a second rod part (75) facing the drum housing (14), wherein the two rod parts (73, 75) are connected to each other in an axially variable length by means of a thread (74), and wherein the second rod part (75) is rotatably driven such that the rod parts (73, 75) are adjustable between a release length (L<sub> F </sub>) and a locking length (L<sub>v</sub>), which is greater than the release length (L<sub> F</sub> ), wherein the piston rod (31) is arranged to engage the wedge carrier (13) in the locking length (L<sub>v</sub>). to be positioned and to block movement of the wedge carrier (13), and preferably of the service brake piston (30), in the clamping direction.
  19. Vehicle drum brake (1) according Claim 4 , characterized in that the piston rod (31) has one or more locking elements (55) which are arranged to be moved back and forth between a retracted release position (F) and an extended locking position (V), wherein the brake carrier (5) has a through-opening (52) through which the piston rod (31) extends, and wherein the locking elements (55) are arranged to move through the through-opening (52) with the piston rod (31) in the release position (F), and to bear against the brake carrier (5) inside the drum housing (14) in front of the through-opening (52) in order to block movement of the service brake piston (30) in the clamping direction.
  20. Brake actuator (23) for a vehicle drum brake (1), in particular for a commercial vehicle, wherein the drum brake (1) comprises a brake carrier (5), a drum (3) rotatable relative to the brake carrier (5) about a drum axis (X) with a circumferentially formed inner friction surface (21), wherein the brake carrier (5) and the drum (3) define a drum housing (14), and a brake lining assembly (7) with several radially movable lining carriers (11), each of which has a brake lining segment (9) facing the friction surface (21), wherein the drum (3) and the brake lining assembly (7) are arranged on a first side (2) on the brake carrier (5), characterized in that the brake actuator (23) has an actuator housing (22) which is configured to be arranged on a second side (8) opposite the first side (2) on the brake carrier (5), wherein the actuator housing (22) has a parking brake device (29) for actuating the brake pad assembly (7).

Description

The present invention relates to a vehicle drum brake, in particular for commercial vehicles, comprising a brake carrier, a drum rotatable relative to the brake carrier about a drum axis with a circumferentially formed inner friction surface, wherein the brake carrier and the drum define a drum housing, a brake lining arrangement with several radially movable lining carriers, on each of which a brake lining segment is provided facing the friction surface, wherein the drum and the brake lining arrangement are arranged on a first side on the brake carrier, and the drum brake has a service brake device and a parking brake device for actuating the brake lining arrangement. Drum brakes are widely known. They are typically used in applications where low-emission operation is desired, meaning operation where the smallest possible amounts of dust or other brake abrasion are released into the environment. Drum brakes are common in the commercial vehicle sector, and occasionally in the passenger car sector, for example, on the rear axle of private vehicles or in electric vehicles, where the possibility of regenerative braking via the electric motors reduces the need for conventional friction brakes. The general operating principle of drum brakes is that the brake lining assembly is pressed against the drum by means of an actuator mechanism. In the prior art, drum brakes with one or two brake linings are known, in which a linear actuator or a crescent-shaped cam head is moved against the brake lining assembly, pressing the brake lining assembly against the drum. Due to the principle and depending on the direction of rotation of the braked wheels, self-reinforcing effects occur, which can be undesirable when controlling braking behavior. Furthermore, during prolonged deceleration, temperature-related and speed-dependent brake fade presents a technical challenge that limits the application areas of drum brakes. In the drum brake described above, both in the prior art and according to the invention, the drum, together with the brake carrier on the first side of the brake carrier, defines a drum housing within which the brake lining assembly is movably arranged. The housing serves to shield the brake lining assembly from external influences and to collect brake dust and other harmful particles and substances that should not enter the environment. The drum housing also contains the mechanical part for moving the brake lining assembly. Due to the size of the brake pads, uneven wear is frequently observed in prior art brake pad arrangements, in particular higher wear on the outward side than on the inward side of the brake pads. It has therefore been proposed that, in a vehicle drum brake of the type described above, the brake pad assembly be equipped with a plurality of radially movable pad carriers, each of which has a brake pad segment facing the friction surface, wherein the pad carriers are each directly operatively connected to a common cam ring such that a rotational movement of the cam ring in a first direction causes a synchronous clamping movement of all pad carriers, and a rotational movement of the cam ring in an opposite second direction causes a synchronous unclamping movement of all pad carriers. This effectively reduces self-reinforcing effects. In DE102021115785 B3 A drum brake has been proposed which integrates a pneumatic actuator within the drum housing, axially overlapping with the brake lining carriers. The pneumatic actuator comprises both a service brake chamber and a spring accumulator chamber. Due to the design of this actuator principle, only very short stroke lengths can be achieved via pneumatic actuation. The component complexity is high, and there is little room within the drum housing for accommodating additional functional components such as particle extraction, sensors, or other mechanical components. The compressed air supply for the pneumatic actuator is also considered problematic, or at least difficult to implement. In contrast, the invention was based on the objective of improving a vehicle drum brake of the type described above in such a way that it overcomes the disadvantages described above as far as possible. In particular, the invention was based on the objective of providing a vehicle drum brake that can implement service brake and parking brake functionality without compromising installation and maintenance efficiency, and ideally, improving installation and maintenance efficiency. The invention solves its underlying problem by proposing a vehicle drum brake with the features of claim 1. In particular, the invention proposes that the drum brake has an actuator with an actuator housing arranged on a second side of the brake carrier opposite the first side, the actuator housing containing the parking brake device. In other words, it is proposed that the actuator housing, due to its attachment to the second side of the brake carrier, is located outside the drum housing. The pneumati