DUO SERVO DRUM BRAKE COMPRISING A FIRST ACTUATOR SUPPORT SERVING AS A FIXED POINT

Abstract

The invention relates to a drum brake (2) for a motorized road vehicle wheel. The drum brake (2) is configured to brake the wheel in dual servo mode during parking braking and service braking of the vehicle. The brake (2) comprises a first actuator support (30) which is configured to mechanically connect a first actuator (5) to a plate (20) of the brake. The first actuator support (30) comprises a first force-recovery wall (31) and a second force-recovery wall (32). The first force-recovery wall (31) is configured to transmit to the plate (20) a thrust force exerted by the first segment (21) during braking. The second wall is configured to transmit to the plate (20) a thrust force exerted by the second segment (23) during braking. (figure 3)

Description

Title of the invention: DUO SERVO DRUM BRAKE COMPRISING A FIRST ACTUATOR SUPPORT SERVING AS A FIXED POINT Technical field of the invention

[0001] The invention relates to the braking of a motor vehicle. It relates to a drum brake for a road vehicle, such as a car or a van. The drum brake is in particular configured to brake in dual servo mode, in service braking and in parking braking. State of the prior art

[0002] [Fig. 1] shows a drum brake 2 for a motorized road vehicle 1 which is known from the state of the art. The drum brake 2 operates in duo servo mode both in service braking and in parking braking. The brake 2 comprises a first segment 21, a second segment 23, a first actuator 5, a fixed point 4, a first return spring 6, a second return spring 8 and a handbrake cable 19. The first actuator 5 is configured to provide service braking and the handbrake cable 19 is pulled during parking braking. The first spring 6 and the second spring 8 are configured to transmit forces from the segments 21, 23 to the fixed point 4 during braking in duo servo mode.

[0003] The drum brake 2 has a significant bulk, in particular near the first actuator 5. The bulk near the first actuator 5 complicates the installation of the brake 2 on a motorized road vehicle hub. As a result, the drum brake 2 is for example likely to be used on vehicles of significant mass and dimensions such as vans or small trucks, with a mass greater than 3.5 tonnes.

[0004] The first return spring 6, the second return spring 8 and the fixed point 4 near the first actuator 5 complicate the manufacture of the drum brake 2.

[0005] There is a need for a motorized road vehicle brake that allows very intense braking while limiting the mass and size of the motorized vehicle brake. Statement of the invention

[0006] The invention aims to remedy all or part of the drawbacks of the state of the art mentioned above.

[0007] In this regard, the invention relates to a drum brake module for a motorized road vehicle wheel. The brake module comprises a plate, a first braking segment, a second braking segment and a first actuator. The first brake segment and the second brake segment are connected to the plate by being rotatably movable relative to the plate. The first actuator is configured to bias the first brake segment or the second brake segment toward a drum to brake the wheel.

[0008] The drum brake is configured to brake the wheel in dual servo mode during parking braking and service braking of the motor vehicle. During braking in dual servo mode, the first braking segment and the second braking segment move in particular in rotation in the same direction relative to the plate, an intermediate element of the brake module transmitting in particular a force from one of the segments to the other of the segments.

[0009] According to the invention, the brake module comprises a first actuator support, the first actuator support is configured to mechanically connect the first actuator to the plate. The first actuator support comprises a first force-recovery wall and a second force-recovery wall. The first force-recovery wall is configured to transmit to the plate a thrust force exerted by the first segment during braking. The second wall is configured to transmit to the plate a thrust force exerted by the second segment during braking.

[0010] Thanks to the brake module as claimed, it is possible to brake a wheel of a motorized road vehicle intensely, while limiting the mass and size of the drum brake. The drum brake is configured to brake the wheel in dual servo mode both in service braking and in parking braking, which allows particularly intense braking of the wheel.

[0011] The mass and size of the drum brake are reduced compared to the mass and size of a duo servo drum brake in service braking and parking braking of known structure. The manufacture of the drum brake and the installation of the drum brake are facilitated compared to the manufacture and installation of the duo servo drum brake of known structure.

[0012] The drum brake tends to be lighter and less bulky than a drum brake of known structure with equivalent braking power, which would operate in simplex mode by spreading the segments during service braking. The drum brake tends to be more energy efficient and more responsive than a drum brake of known structure with equivalent braking power, which would operate in simplex mode during service braking.

[0013] With equivalent dimensions with a drum brake of known power structure, which would operate in simplex mode in service braking, the drum brake according to the invention has a reduced size. It thus becomes possible to install a duo servo drum brake both in service braking and in stationary braking. operation on vehicles of lower mass and smaller size, for example cars with a mass of less than 3.5 tonnes.

[0014] According to a particular embodiment, the first actuator comprises a first pusher and a second pusher. The first pusher is configured to push the first segment against the drum. The second pusher is configured to push the second segment against the drum. The first force-recovery wall is configured to transmit to the plate a thrust force exerted by the first segment on the first pusher during braking. The second force-recovery wall is configured to transmit to the plate a thrust force exerted by the second segment on the second pusher during braking.

[0015] According to a particular embodiment, the first force-recovery wall and / or the first pusher comprises a first axial stop of the first pusher relative to the first force-recovery wall. The first axial stop is configured to axially stop the first pusher during a pushing force of the first segment on the first pusher.

[0016] According to another embodiment feature, the second force-recovery wall and / or the second pusher comprises a second axial stop of the second pusher relative to the second force-recovery wall. The second axial stop is configured to axially stop the second pusher during a thrust force of the second segment on the second pusher.

[0017] According to a particular embodiment, the first force-recovery wall is a first transverse wall. The first transverse wall is perpendicular to an actuation direction of the first actuator.

[0018] According to another embodiment feature, the second force-recovery wall is a second transverse wall. The second transverse wall is perpendicular to an actuation direction of the first actuator.

[0019] According to a particular embodiment, the first actuator support comprises a first longitudinal wall which extends from the first force-recovery wall towards the second force-recovery wall.

[0020] According to another particular embodiment, the first actuator support comprises a second longitudinal wall which extends from the second force-recovery wall towards the first force-recovery wall.

[0021] Preferably, the first longitudinal wall extends from the first force-recovery wall to the second force-recovery wall. Preferably, the second longitudinal wall extends from the second force-recovery wall to the first force-recovery wall.

[0022] According to a particular embodiment, the first longitudinal wall is substantially perpendicular to the first transverse wall. According to another particular feature of embodiment, the second longitudinal wall is substantially perpendicular to the second transverse wall. According to a particular embodiment, the second longitudinal wall is substantially parallel to the first longitudinal wall.

[0023] According to a particular embodiment, the first actuator support is fixed to the plate.

[0024] According to a particular embodiment, the first actuator support comprises a first support fixing wall for fixing the first actuator support to the plate. According to another particular embodiment, the first actuator support comprises a second support fixing wall for fixing the first actuator support to the plate.

[0025] Preferably, the first fixing wall is fixed by a fixing rod to the tray. Preferably, the second fixing wall is fixed by a fixing rod to the tray.

[0026] According to a particular embodiment, the first actuator is a hydraulic actuator. The first actuator is configured to be supplied with hydraulic brake fluid to urge the movement of the first segment or the second segment against the drum.

[0027] According to another particular embodiment, the first actuator is configured to urge the first segment or the second segment against the drum during service braking of the vehicle.

[0028] According to a particular embodiment, the brake module comprises a brake lever which is configured to pivot by urging the first segment towards the drum, during parking braking of the vehicle.

[0029] According to a particular embodiment, the brake module comprises a second actuator configured to urge the first braking segment or the second braking segment towards a drum to brake the wheel.

[0030] According to a particular embodiment, the second actuator is an electromechanical actuator. According to another particular embodiment, the second actuator is configured to urge the first segment or the second segment towards the drum during parking braking of the motorized vehicle.

[0031] According to a particular embodiment, the brake module comprises a first intermediate element, in particular for taking up play, a second intermediate element and a retaining spring. The first intermediate element connects a first longitudinal end of the first segment to a first longitudinal end of the second segment. The second intermediate element and the retaining spring connect a second longitudinal end of the first segment to a second longitudinal end of the second segment.

[0032] Preferably, the first intermediate element comprises a connecting rod. Preferably, the second intermediate element comprises a connecting rod.

[0033] According to a particular embodiment, during service braking and when the wheel and the drum rotate forward, the first actuator exerts an input braking force on the first segment by urging the first segment towards the drum, the first segment rubs against the drum, the second intermediate element transmits the force an intermediate force from the first segment to the second segment, the second segment rubs against the drum, the first longitudinal end of the second segment exerts an output thrust force on the second pusher and on the second force-recovery wall.

[0034] According to a particular embodiment, during parking braking and when the wheel and the drum are rotated rearwardly, when the first longitudinal end of the brake lever is pulled with an input force, the lever pivots around the second longitudinal end of the lever and the lever urges the first segment towards the drum, the first intermediate element transmits the force, a first intermediate force from the first segment to the second segment, the second segment rubs against the drum with a second intermediate force, the second intermediate element transmits the second intermediate force from the second segment to the first segment, the first longitudinal end of the first segment exerts an output thrust force on the first pusher and on the first force-recovery wall. brief description of the figures

[0035] The present invention will be better understood upon reading the description of non-limiting exemplary embodiments, with reference to the appended drawings in which illustrate: • [Fig.l]: a schematic perspective representation of a dual servo drum brake in parking braking and service braking, according to an embodiment known from the state of the art; • [Fig.2]: a perspective representation of a drum brake according to a first embodiment, which is installed on a motorized vehicle; • [Fig.3]: a front view representation of a drum brake according to the first embodiment; • [Fig.4]: a cross-sectional representation along line IV-IV of the [Fig.3] of a drum brake according to the first embodiment; • [Fig.5]: a perspective representation seen from the front of a first ac tioner and a support of the first actuator of the drum brake according to the first embodiment; • [Fig.6]: a perspective representation seen from behind of the first ac tioner and support of the first drum brake actuator according to the first embodiment; • [Fig.7]: a front view representation of a drum brake according to a second embodiment; • [Fig.8]: operation in dual servo mode of a drum brake according to the first or second embodiment in service braking; • [Fig.9]: operation in dual servo mode of a drum brake according to the first or second embodiment in parking braking.

[0036] For clarity, identical or similar elements are identified by identical reference signs throughout the figures. DETAILED description of an embodiment

[0037] [Fig. 2] represents a motorized road vehicle 1 which comprises a drum brake 2 according to the first embodiment of the invention which is installed around a hub 12 of the vehicle, to brake a wheel of the vehicle 1. The drum brake 2 comprises a drum 3 which is fixed to the wheel and a brake module which is fixed to a fixed part of the vehicle 1 such as a chassis 11 of the vehicle.

[0038] With joint reference to Figures 2 to 9, the drum brake 2 comprises a drum 3, a plate 20, a first braking segment 21, a second braking segment 23, a first actuator 5, a first actuator support 30 and a lever 9. The drum brake 2 also comprises a first play-compensating insert 22, a second insert 26 and a retaining spring 24. In the first embodiment shown in Figures 2 to 6, the drum brake 2 comprises a second actuator 7.

[0039] The drum brake 2 is configured to brake the wheel in dual servo mode during parking braking and service braking of the vehicle 1. During dual-servo braking, the first segment 21 and the second segment 23 move in rotation in the same direction relative to the plate 20, an intermediate element 22, 26 of the brake transmitting a braking force from one of the segments 21, 23 to the other of the segments 21, 23.

[0040] The plate 20 serves as a support for the brake module, in particular for the segments 21, 23, for the first actuator 5 and for the second actuator 7. The plate 20 comprises an insertion hole 25 for a vehicle hub. The plate 20 also serves in particular as a support for the first actuator support 30 which is fixed to the plate 20. The plate 20 has substantially the shape of a disc hollowed out in its center around the insertion hole 25 of the hub. The plate 20 is substantially symmetrical in revolution around a direction of rotation XX which corresponds substantially to the longitudinal direction of the vehicle hub 12, when the brake 2 is installed on the vehicle 1.

[0041] In this document, a direction of rotation XX is a direction which parallel with the axis of revolution of the plate 20. In the absence of specific specification to the contrary, an axial direction is a direction parallel to the longitudinal direction ZZ of the first actuator. An axial direction is also a direction parallel to the actuation direction of the first actuator 5 on the first segment 21 or on the second segment 23. A transverse direction is a direction orthogonal to the direction of rotation XX and to the axial direction. A radial direction is a direction of a radius of the plate 20 which is locally perpendicular to the direction of rotation XX.

[0042] The first braking segment 21 and the second braking segment 23 are connected to the plate 20 while being movable in rotation relative to the plate 20. The first braking segment 21 extends longitudinally between a first longitudinal end 21a which is located near the first actuator 5 and a second longitudinal end 21b which is located near the second intermediate element 26 and the holding spring 24. The second segment 23 extends longitudinally between a first longitudinal end 23a which is located near the first actuator 5 and a second longitudinal end 23b which is located near the second intermediate element 26 and the holding spring 24. When the segments 21, 23 are at rest, they extend for example transversely.The first segment 21 and the second segment 23 are configured to brake the wheel by friction against the drum 3, when they are actuated relative to the plate 20.

[0043] The lever 9 is connected to the plate 20 while being pivotally movable relative to the plate 20. The lever 9 extends longitudinally between a first longitudinal end 9a which is located near the second intermediate element 26 and the holding spring 24 and a second longitudinal end 9b which is located near the first actuator 5. During parking braking of the vehicle, the lever 9 is configured to be pulled at its first longitudinal end 9a and to pivot about its second longitudinal end 9b. The lever 9 is configured to pivot by urging the first segment 21 towards the drum 3, during parking braking of the vehicle.

[0044] The first intermediate element 22 comprises a connecting rod and a spring. The first intermediate element 22 is located near the first actuator 5, being located between the first actuator 5 and the insertion orifice 25 of the hub. The first intermediate element 22 extends axially between the first segment 21 and the second segment 23. The first intermediate element 22 connects the first longitudinal end 21a of the first segment to the first longitudinal end 23a of the second segment. The first intermediate element 22 is a member for incrementally taking up play related to the wear of the segment linings 21, 23. The first intermediate element 22 is configured to maintain a constant spacing between the segments 21, 23 at rest. taking into account the wear of the segments 21, 23. In dual servo mode, the first intermediate element 22 is in particular configured to transmit a displacement of the first longitudinal end 21a of the first segment relative to the first end 23a of the second segment, tending to move them parallel to each other relative to the plate 20.

[0045] The second intermediate element 26 comprises a connecting rod. The second intermediate element 26 is located near the retaining spring 24, being located substantially diametrically opposite the first intermediate element 22 relative to the insertion orifice 25 of the hub. The second intermediate element 26 extends, for example, substantially between the insertion orifice 25 of the hub and the retaining spring 24. The second intermediate element 26 extends axially between the first segment 21 and the second segment 23. The second intermediate element 26 connects the second longitudinal end 21b of the first segment to the second longitudinal end 23b of the second segment. The second intermediate element 26 is configured to transmit a displacement of the second longitudinal end 21b of the first segment relative to the second end 23b of the second segment, tending to move them parallel to each other relative to the plate 20.

[0046] The retaining spring 24 is diametrically opposite the first actuator 5 relative to the insertion orifice 25 of the hub. The retaining spring 24 extends axially between the first segment 21 and the second segment 23. The retaining spring 24 connects the second longitudinal end 21b of the first segment to a second longitudinal end 23b of the second segment. The retaining spring 24, the first intermediate element 22 and the second intermediate element 26 are for example strictly parallel two by two. The retaining spring 24 is configured to elastically bias the second longitudinal end 21b of the first segment and the second longitudinal end 23b of the second segment towards each other, in particular when the brake 2 is at rest.

[0047] With more specific reference to the first embodiment shown, the drum brake 2 comprises a second actuator 7. The second actuator 7 is an electromechanical actuator and it comprises a geared motor. The second actuator 7 is configured to urge the first braking segment 21 towards the drum 3 to brake the wheel, when the second actuator 7 pulls a braking cable 29 and pivots the lever 9 by urging the first segment 21 towards the drum 3. The second actuator 7 is configured to urge the first segment 21 towards the drum 3 during parking braking of the vehicle.

[0048] With reference to each of the two embodiments shown, the first actuator 5 comprises a body 50, a first piston 51, a first pusher 53, a second piston 54, a second pusher 56, a spacer spring 52, a member coupling 57. The first actuator 5 is a hydraulic actuator. The first actuator 5 is configured to be supplied with hydraulic brake fluid, by a hydraulic connection member 55, to request the movement of the first segment 21 or the second segment 23 against the drum 3. The first actuator 5 is also known as a “wheel cylinder”. The first actuator 5 is configured to brake the wheel during service braking of the vehicle.

[0049] The body 50 of the first actuator defines a hydraulic chamber for the brake fluid. The body 50 forms a housing of the first actuator. The body 50 extends longitudinally in the longitudinal direction ZZ of the first actuator and the actuation direction of the first actuator 5. The spacer spring 52 is located between the first piston 51 and the second piston 54. It is configured to urge the segments 21, 23 apart from each other.

[0050] The first pusher 53 is located between the first piston 51 and the first segment 21. The first pusher 53 is configured to push the first end 21a of the first segment when it is moved axially by the first piston 51 towards the outside of the body 50. The first pusher 53 is mechanically connected to the first piston 51 by the coupling member 57. The first pusher 53 is configured to push the first segment 21 against the drum 3. In particular, the first actuator 5 is configured to exert a hydraulic thrust force on the first segment 21 via the first piston 51 and the first pusher 53.

[0051] The second pusher 56 is located between the second piston 54 and the second segment 23. The second pusher 56 is configured to push the first end 23a of the second segment when it is moved axially by the second piston 54 towards the outside of the body 50. The second pusher 56 is mechanically connected to the second piston 54 by the coupling member 57. The second pusher 56 is configured to push the second segment 23 against the drum 3. In particular, the first actuator 5 is configured to exert a hydraulic thrust force on the second segment 23 via the second piston 54 and the second pusher 56.

[0052] The coupling member 57 is configured to mechanically rigidly connect by form cooperation the first piston 51 to the first pusher 53 and to mechanically rigidly connect by form cooperation the second piston 54 to the second pusher 56.

[0053] The first actuator support 30 comprises a first force-recovery wall 31, a second force-recovery wall 32, a first longitudinal wall 33, a second longitudinal wall 34, a first fixing wall 37, a second fixing wall 38 and fixing elements 39. The first actuator support 30 is configured to mechanically connect the first actuator 5 to the plate 20, transmitting thrust forces exerted by the first segment 21 and by the second segment 23 to the plate 20.

[0054] The first force-recovery wall 31 is a first transverse wall in the two embodiments shown. The first force-recovery wall 31 comprises a first axial stop 60. The first force-recovery wall 31 is configured to transmit a thrust force exerted by the first segment 21 to the plate 20. The first force-recovery wall 31 transmits to the plate 20 a thrust force exerted by the first segment 21 on the first force-recovery wall 31 during braking. The first force-recovery wall 31 transmits to the plate 20 a thrust force exerted by the first segment 21 on the first pusher 53 during braking. The first force-recovery wall 31 acts as a first fixed point 5a for the brake.

[0055] The second force-recovery wall 32 is a second transverse wall in the two embodiments shown. The second force-recovery wall 32 comprises a second axial stop 64. The second force-recovery wall 32 is configured to transmit a thrust force exerted by the second segment 23 to the plate 20. The second force-recovery wall 32 transmits to the plate 20 a thrust force exerted by the second segment 23 on the second force-recovery wall 32 during braking. The second force-recovery wall 32 transmits to the plate 20 a thrust force exerted by the second segment 23 on the second pusher 56 during braking. The second force-recovery wall 32 acts as a second fixed point 5b for the brake.

[0056] In each of the embodiments shown, the first force-recovery wall 31 is a transverse wall. The first force-recovery wall 31 is substantially perpendicular to the actuation direction ZZ of the first actuator. More generally, the first force-recovery wall 31 has a non-zero component in the transverse direction. The first force-recovery wall 31 may be curved. In each of the embodiments shown, the second force-recovery wall 32 is a transverse wall. The second force-recovery wall 32 is substantially perpendicular to the actuation direction ZZ of the first actuator. More generally, the second force-recovery wall 32 has a non-zero component in the transverse direction. The second force-recovery wall 32 may be curved.

[0057] The first axial stop 60 is an axial stop of the first pusher 53 relative to the first force-recovering wall 31. The first axial stop 60 is configured to axially stop the first pusher 53 during a thrust force of the first segment 21 on the first pusher 53. In each of the embodiments shown, the first axial stop 60 is formed by the shape cooperation between a protrusion of the first pusher 53 and of the first force-recovery wall 31.

[0058] The second axial stop 64 is an axial stop of the second pusher 56 relative to the second force-recovery wall 32. The second axial stop 64 is configured to axially stop the second pusher 56 during a thrust force of the second segment 23 on the second pusher 56. In each of the embodiments shown, the second axial stop 64 is formed by the shape cooperation between a protuberance of the second pusher 56 and the second force-recovery wall 32.

[0059] The first longitudinal wall 33 extends from the first force-recovery wall 31 to the second force-recovery wall 32. More generally, the first longitudinal wall 33 extends from the first force-recovery wall 31 to the second force-recovery wall 32. The first longitudinal wall 33 extends with a non-zero axial component between the first pusher 53 and the second pusher 56. The first longitudinal wall 33 serves to transfer thrust forces from the first force-recovery wall 31 or from the second force-recovery wall 32 to the plate 20.

[0060] In each of the embodiments shown, the first longitudinal wall 33 extends substantially axially. The first longitudinal wall 33 is substantially perpendicular to the first transverse wall 31. The first longitudinal wall 33 serves to transfer thrust forces between the first force-recovery wall 31 and the second force-recovery wall 32.

[0061] The second longitudinal wall 34 extends from the second force-recovery wall 32 to the first force-recovery wall 31. More generally, the second longitudinal wall 34 extends from the second force-recovery wall 32 to the first force-recovery wall 31. The second longitudinal wall 34 extends with a non-zero axial component between the first pusher 53 and the second pusher 56. The second longitudinal wall 34 serves to transfer thrust forces from the first force-recovery wall 31 or from the second force-recovery wall 32 to the plate 20.

[0062] In each of the embodiments shown, the second longitudinal wall 34 extends substantially axially. The second longitudinal wall 34 is substantially perpendicular to the second force-recovering wall 32. The second longitudinal wall 34 is substantially parallel to the first longitudinal wall 33. The second longitudinal wall 34 serves to transfer thrust forces between the first force-recovering wall 31 and the second force-recovering wall 32.

[0063] The first fixing wall 37 extends substantially perpendicular to the first force-recovery wall 31 and to the first longitudinal wall 33. The first fixing wall 37 serves to fix the support 30 of the first actuator to the plate 20. The first fixing wall 37 is fixed to the plate 20 through a fixing hole 41 by a fixing element 39 which comprises a rod. In the embodiments shown, this fixing element 39 is a rivet.

[0064] The second fixing wall 38 extends substantially perpendicular to the second force-recovery wall 32 and to the second longitudinal wall 34. The second fixing wall 38 serves to fix the first actuator support 30 to the plate 20. The second fixing wall 38 is fixed to the plate 20 through a fixing orifice 41 by a fixing element 39 which comprises a rod. In the embodiments shown, the fixing element 39 is a rivet.

[0065] With more specific reference to the second embodiment which is shown in [Fig.7], the drum brake 2 differs from that of the first embodiment in that it is devoid of a second actuator 7. The drum brake 2 according to the second embodiment comprises a handbrake cable (not shown) which is designed to be pulled by a handbrake lever (not shown) located in a passenger compartment of the vehicle 1, during parking braking of the vehicle 1. The handbrake cable is connected to the first longitudinal end 9a of the lever 9 and to the handbrake lever.

[0066] [Fig.8] illustrates a duo servo service braking by a drum brake 2 according to the first embodiment or according to the second embodiment. In service braking, the wheel and the drum 3 generally rotate forward, as symbolized by the arrow RL. The first actuator 5 exerts an input braking force F1 on the first segment 21 by urging the first segment 21 towards the drum 3. The first segment 21 rubs against the drum near its first longitudinal end 21a. The second intermediate element 26 transmits the force, an intermediate force 2F1, from the first segment 21 to the second segment 23. The second segment 23 rubs against the drum near its second longitudinal end 23b. The first longitudinal end 23a of the second segment exerts an output thrust force 4F1 on the second pusher 56 and on the second force-recovery wall 32.The braking of the wheel is particularly intense.

[0067] [Fig. 9] illustrates a dual servo parking brake by a drum brake 2 according to the first embodiment or according to the second embodiment. In parking braking, the wheel and the drum 3 are for example likely to be rotated backwards due to a slope of the road, as symbolized by the arrow R2. When it is pulled on the first longitudinal end 9a of the brake lever with an input force F2, the lever 9 pivots around its second longitudinal end 9b and the lever 9 urges the first segment 21 towards the drum 3, close to the first longitudinal end 21a of the first segment. The first intermediate element 22 transmits the force a first intermediate force F3 from the first segment 21 to the second segment 23. The second segment 23 rubs against the drum near its second longitudinal end 23b, with a second intermediate force 2F3. The second intermediate element 26 transmits the second intermediate force 2F3 from the second segment 23 to the first segment 21. The first longitudinal end 21a of the first segment exerts an output thrust force 4F3 on the first pusher 53 and on the first force-recovery wall 31. The braking of the wheel is particularly intense.

[0068] Thanks to the drum brake 2 according to the invention, it is possible to brake a wheel of a motorized road vehicle 1 intensely, while limiting the mass and size of the drum brake 2. The drum brake 2 is configured to brake the wheel in dual servo mode both in service braking and in parking braking, which allows particularly intense braking of the wheel of the vehicle 1.

[0069] By replacing a first return spring 6, a second return spring 8 and a fixed point 4 with a first actuator support 30, the mass and size of the drum brake 2 are reduced compared to the mass and size of a drum brake 2 of known structure which is a dual servo in service and parking braking. In particular, the size is limited in the vicinity of the first actuator 5 and an insertion hole 25 of the vehicle hub. Due to the reduced mass and bulk of the drum brake 2, it is easier to install the brake 2 around a hub 12 of the motorized vehicle 1, which is generally a crowded region of the brake 2. By replacing a first return spring 6, a second return spring 8 and a fixed point 4 with a first actuator support 30, the manufacture of the drum brake 2 is facilitated compared to a duo servo drum brake 2 of known structure.

[0070] The drum brake 2 tends to be lighter and less bulky than a drum brake 2 of known structure with equivalent braking power, which would operate in simplex mode by spreading the segments during service braking. In particular, the size and mass of the plate 20, the segments 21, 23 and the first actuator 5 are likely to be further limited.

[0071] The drum brake 2 tends to be more energy efficient and more responsive than a drum brake 2 of known structure with equivalent braking power, which would operate in simplex mode in service braking. When the first actuator 5 is a hydraulic actuator, it is in particular possible to reduce the diameter of the brake piston 51, 54 and to increase the responsiveness of the hydraulic braking.

[0072] With equivalent dimensions with a drum brake 2 of known power structure, which would operate in simplex mode in service braking, the brake 2 drum according to the invention has a reduced footprint. It thus becomes possible to install a dual servo drum brake 2 both for service braking and for parking braking on vehicles 1 of lower mass and smaller size than those on which dual servo service brakes are usually installed. For example, the drum brake 2 according to the invention can be installed to brake a wheel of an automobile whose mass is less than 3.5 tonnes.

[0073] Of course, various modifications can be made by those skilled in the art to the invention which has just been described without departing from the scope of the disclosure of the invention.

[0074] Alternatively, the first actuator support 30 is in one piece with the plate 20.

[0075] Alternatively, the first intermediate element 22 comprises a connecting rod and a spring. retaining springs which are strictly parallel to each other. Additionally or alternatively, the retaining spring 24 is closer to the first spacer element 22 than to the second spacer element 26.

[0076] Alternatively, the second actuator 7 is a hydraulic actuator. The second actuator 7 comprises a hydraulic chamber. As a further alternative, the second actuator 7 is replaced by a hand lever 9 in a passenger compartment of the motor vehicle.

[0077] Alternatively, the first actuator 5 is an electromechanical actuator. The first actuator 5 comprises a geared motor.

[0078] Alternatively, the first pusher 53 is in one piece with the first piston. In addition or as a variant, the second pusher 56 is in one piece with the second piston.

[0079] As a variant, the first pusher 53 comprises a first axial stop 60 of the first pusher 53 relative to the first force-recovery wall 31. As a variant, the second pusher 56 comprises a second axial stop 64 of the second pusher 56 relative to the second force-recovery wall 32.

[0080] As a variant, the first axial stop 60 is formed by a projecting portion of the first force-recovery wall 31 which cooperates mechanically with the first pusher 53. As a variant, the second axial stop 64 is formed by a projecting portion of the second force-recovery wall 32 which cooperates mechanically with the second pusher 56.

[0081] Alternatively, the first force-recovery wall 31 is inclined relative to the transverse direction. In addition or as a variant, the second force-recovery wall 32 is inclined relative to the transverse direction.

[0082] Alternatively, the first longitudinal wall 33 is inclined relative to the axial direction. Additionally or alternatively, the second longitudinal wall 34 is inclined relative to the axial direction. LIST OF DIGITAL REFERENCES

[0083] 1: Vehicle

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[0121] 2: Brake 3: Drum 4: Fixed point 5: First actuator 5 a: First fixed point 5b: Second fixed point 6: First return spring 7: Second actuator 8: Second return spring 9: lever 9a: first longitudinal end of the lever 9b: second longitudinal end of the lever 11: Chassis 12: Hub 19: handbrake cable 20: Plateau 21: First segment 21a: first longitudinal end of the first segment 21b: second longitudinal end of the first segment 22: First intermediate element 23: Second segment 23 a: first longitudinal end of the second segment 23b: second longitudinal end of the second segment 24 Holding spring 25 Hub insertion hole 26 Second spacer 29 Brake cable 30 First actuator support 31 First force-recovery wall, First transverse wall 32 Second force-recovery wall, Second transverse wall 33 First longitudinal wall 34 Second longitudinal wall 37 First fixing wall 38 Second fixing wall 39 Fixing element 41 Fixing hole 50 First actuator body 51 First piston

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[0140] 52: Spreader spring 53: First pusher 54: Second piston 55: Hydraulic connection member 56: Second pusher 57: Coupling member 60: First axial stop 64: Second axial stop XX: Direction of the axis of rotation of the drum ZZ: Axial direction RI: Forward rotation of the wheel 2F1: Intermediate force 4F1: Output thrust force Fl: Input braking force R2: Backward rotation of wheel F2: Input force F3: Intermediate force 2F3: second intermediate force 4F3: Output thrust force

Claims

Claims

1. Drum brake module (2) for a wheel of a motorized road vehicle (1), comprising: a plate (20), a first braking segment (21) and a second braking segment (23) which are connected to the plate (20) while being rotatable relative to the plate (20), a first actuator (5) configured to urge the first braking segment (21) or the second braking segment (23) towards a drum (3) to brake the wheel, the drum brake (2) being configured to brake the wheel in dual servo mode during parking braking and service braking of the vehicle (1), during braking in dual servo mode, the first segment (21) and the first segment (23) being in particular each rotatable in the same direction relative to the plate (20), an intermediate element (22, 26) of the brake module transmitting in particular a braking force from one of the segments (21, 23) to the other of the segments (21, 23) ,characterized in that the brake module comprises a first actuator support (30), the first actuator support (30) being configured to mechanically connect the first actuator (5) to the plate (20), the first actuator support (30) comprising a first force-recovery wall (31) and a second force-recovery wall (32), the first force-recovery wall (31) being configured to transmit to the plate (20) a thrust force exerted by the first segment (21) during braking, the second wall being configured to transmit to the plate (20) a thrust force exerted by the second segment (23) during braking.,

2. Drum brake module (2) according to the preceding claim, wherein the first actuator (5) comprises a first pusher (53) and a second pusher (56), the first pusher (53) being configured to push the first segment (21) against the drum (3), the second pusher (56) being configured to push the second segment (23) against the drum (3), the first force-recovery wall (31) being configured to transmit to the plate (20) a thrust force exerted by the first segment (21) on the first pusher (53) during braking, the second force-recovery wall (32) being configured to transmit to the plate (20) a thrust force exerted by the second segment (23) on the second pusher (56) during braking.

3. Drum brake module (2) according to the preceding claim, in wherein the first force-recovery wall (31) and / or the first pusher (53) comprises a first axial stop (60) of the first pusher (53) relative to the first force-recovery wall (31), the first axial stop (60) being configured to axially stop the first pusher (53) during a pushing force of the first segment (21) on the first pusher (53), and / or wherein the second force-recovery wall (32) and / or the second pusher (56) comprises a second axial stop (64) of the second pusher (56) relative to the second force-recovery wall (32), the second axial stop (64) being configured to axially stop the second pusher (56) during a pushing force of the second segment (23) on the second pusher (56).

4. Drum brake module (2) according to any one of the preceding claims, in which the first force-recovering wall (31) is a first transverse wall, the first transverse wall being perpendicular to an actuation direction (ZZ) of the first actuator, and / or in which the second force-recovering wall (32) is a second transverse wall, the second transverse wall being perpendicular to an actuation direction (ZZ) of the first actuator.

5. A drum brake module (2) according to any one of the preceding claims, wherein the first actuator support (30) comprises a first longitudinal wall (33) which extends from the first force-recovering wall (31) to the second force-recovering wall (32), the first longitudinal wall (33) preferably extending from the first force-recovering wall (31) to the second force-recovering wall (32), and / or wherein the first actuator support (30) comprises a second longitudinal wall (34) which extends from the second force-recovering wall (32) to the first force-recovering wall (31), the second longitudinal wall (34) preferably extending from the second force-recovering wall (32) to the first force-recovering wall (31).

6. Drum brake module (2) according to the preceding claim, in which the first longitudinal wall (33) is substantially perpendicular to the first transverse wall (31), the second longitudinal wall (34) being substantially perpendicular to the second transverse wall (32), and / or the second longitudinal wall (34) being substantially parallel to the first longitudinal wall (33).

7. Drum brake module (2) according to any one of the preceding claims, wherein the first actuator support (30) is fixed to the plate (20), wherein the first actuator support (30) comprises in particular a first fixing wall (37) of the support for fixing the first actuator support (30) to the plate (20), the first fixing wall (37) preferably being fixed by a fixing rod to the plate (20), and / or wherein the first actuator support (30) comprises in particular a second fixing wall (38) of the support for fixing the first actuator support (30) to the plate (20), the second fixing wall (38) preferably being fixed by a fixing rod to the plate (20).

8. A drum brake module (2) according to any one of the preceding claims, wherein the first actuator (5) is a hydraulic actuator, the first actuator (5) being configured to be supplied with hydraulic brake fluid to urge the movement of the first segment (21) or the second segment (23) against the drum (3), and / or wherein the first actuator (5) is configured to urge the first segment (21) or the second segment (23) against the drum (3) during service braking of the vehicle.

9. Drum brake module (2) according to any one of the preceding claims, wherein the brake module comprises a brake lever (9) which is configured to pivot by urging the first segment (21) towards the drum (3), during parking braking of the vehicle.

10. A drum brake module (2) according to any preceding claim, wherein the brake module comprises a second actuator (7) configured to bias the first braking segment (21) or the second braking segment (23) towards a drum (3) to brake the wheel, the second actuator (7) being an electromechanical actuator, and / or the second actuator (7) being configured to bias the first segment (21) or the second segment (23) towards the drum (3) during parking braking of the vehicle.

11. Drum brake module (2) according to any one of the preceding claims, in which the brake module comprises a first intermediate element (22), in particular for taking up play, a second intermediate element (26) and a retaining spring (24), the first intermediate element (22) connecting a first end Ion- longitudinal (21a) of the first segment to a first longitudinal end (23a) of the second segment, the second intermediate element (26) and the holding spring (24) connecting a second longitudinal end (21b) of the first segment to a second longitudinal end (23b) of the second segment, the first intermediate element (22) preferably comprising a connecting rod, the second intermediate element (26) preferably comprising a connecting rod.

12. Drum brake module (2) according to claims 8 to 11 and according to claim 2, wherein in service braking and when the wheel and the drum (3) rotate forward, the first actuator (5) exerts an input braking force (F1) on the first segment (21) by urging the first segment (21) towards the drum (3), the first segment (21) rubs against the drum (3), the second intermediate element (26) transmits the force an intermediate force (2F1) from the first segment (21) to the second segment (23), the second segment (23) rubs against the drum (3), the first longitudinal end (23a) of the second segment exerts an output thrust force (4F1) on the second pusher (56) and on the second force-recovery wall (32).

13. Drum brake module (2) according to claims 8 to 12 and according to claim 2, wherein in parking braking and when the wheel and the drum (3) are rotated rearwardly, when the first longitudinal end (9a) of the brake lever is pulled with an input force (F2), the lever (9) pivots about the second longitudinal end (9b) of the lever and the lever (9) urges the first segment (21) towards the drum (3), the first intermediate element (22) transmits the force a first intermediate force (F3) from the first segment (21) to the second segment (23), the second segment (23) rubs against the drum (3), with a second intermediate force (2F3), the second intermediate element (26) transmits the second intermediate force (2F3) from the second segment (23) to the first segment (21),the first longitudinal end (21a) of the first segment exerts an output thrust force (4F3) on the first pusher (53) and on the first force-recovery wall (31).

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