Mechatronic braking system

Abstract

The present invention comprises an electromechanical braking module integrating an electric drive system for a brake caliper, including a housing (700) containing a main motor (100), the rotating shaft (115) of which has a coupling means with a transmission element of the brake caliper, and an electric actuator (200) controlling a locking system (400) immobilizing an element fixed to the shaft of said main motor (100), characterized in that said braking system comprises a single printed circuit board (500) disposed in a plane perpendicular to the axis of the main motor (100), the coils (150) of said main motor (100) being electrically and mechanically connected to said printed circuit board (500). In that the median plane (930) of said locking system is disposed between the plane (920) of said printed circuit board (500) and the plane of the front surface (910) of the stator head (120) of said main motor (100),the closest to said printed circuit board (500) And in that said element integral with the shaft of said main motor (100) and said drive means of said caliper transmission member are located on either side of the stator head of said main motor (100). Figure of the abstract: figure 1,

Description

Title of the invention: Mechatronic braking system Scope of the invention

[0001] The present invention relates to a complete electromechanical braking module integrating an electromechanical system for driving a brake caliper and an electronic parking brake (EPB) means, and more particularly, an EPB which acts on the caliper drive system to lock it in the closed position during parking phases.

[0002] When an ECU (electronic control unit) receiving electronic information drives a motor to generate torque and rotation during a braking operation, a screw-nut system coupled to said motor is moved towards a brake pad. The brake pad, receiving the axial displacement force from the screw-nut system, is moved towards a wheel disc and generates a braking force by pressurizing said wheel disc.

[0003] When parking brake functions are integrated, such a complex mechanism can become larger, heavier, and bulkier than a hydraulic caliper. Prior art

[0004] Prior art is known US patent 9568057 concerning an electronic braking system (EPB) comprising a housing unit, a drive unit installed in the housing unit, a deceleration unit connected to the drive unit to transfer power, and a pin connected to the deceleration unit to receive energy from the deceleration unit and move a brake pad. A locking unit is mounted in the housing. Its length is adjusted to limit the operation of the drive unit. A detection unit detects the operating state of the drive unit. A control unit, receiving a detection signal from the detection unit and a parking signal, controls the operation of the drive unit.

[0005] Patent application WO2023166434A1 relates to a brake caliper for a disc brake comprising a caliper body which includes two lateral walls spaced apart and defining a disc space to house a portion of a brake disc. A connecting structure extends across the disc space and connects the lateral walls to each other. At least one pad recess formed in each of said lateral walls is designed to receive at least one pad. A transmission housing extends between an associated front wall and an opposite rear wall. It is connected to the caliper body such that the front wall of the transmission housing is Oriented towards the disc space. Pushing means are designed to apply pressure to the brake pads against the brake disc along an actuation axis transverse to the side walls. These pushing means are at least partially housed within the transmission housing. A control unit is connected to the transmission housing at the rear wall of the transmission housing. The control unit supports and houses an electric motor comprising a drive shaft. The electric motor is designed to generate and transfer mechanical power to the pushing means via the drive shaft. This electric motor is at least partially housed within a motor housing formed by the control unit; a brake control unit designed to control the electric motor. The brake control unit is housed within a control compartment delimited by the control unit.The electric motor is electrically connected to the brake control unit. The drive shaft extends in a direction parallel to the actuation axis and protrudes from one front side of the electric motor opposite the caliper body. The brake control unit comprises at least one electronic circuit board. The electronic circuit board extends in a direction transverse to the actuation axis.

[0006] Patent application EP0974506 relates to a vehicle brake actuation device comprising an electric motor and a coupling element coupled in accordance with the movement, linearly movable and connectable to a brake tensioning mechanism, said coupling element being transferred from a braking position to an unlocking position by the driven electric motor. An electrically actuated locking device ensures that the movement of the coupling element is blocked, at least in the unlocking position. A spring accumulator is coupled to the storage equipment, storing elastic energy in the unlocking position and activating the braking position when the movement is released by means of this elastic energy.

[0007] Patent application EP3289239 relates to an electromechanically controlled brake caliper locking device for a disc brake, comprising a ratchet having a rotating element comprising at least a first cam and a first follower pushed elastically against the rotating element, configured to act jointly with the first cam to permit the rotation of the rotating element in a first direction of rotation (A) and to prevent the rotation of the rotating element in a second direction of rotation (R) opposite to said first direction of rotation.

[0008] US patent application 20230151861 describes an actuator assembly for a vehicle brake, which includes a control assembly, installed as a separate subunit and which has a separation panel and a circuit board The printed material is attached to this partition panel. The actuator assembly also includes a drive assembly comprising a carrier unit on which are mounted an electric motor, a spindle drive, and a gearbox, which drives the electric motor and the spindle drive. The control unit and the drive assembly are housed in a common casing.

[0009] Patent application EP3663149 describes a locking device for an electromechanical service brake of a motor vehicle. The electromechanical service brake comprises a locking wheel, mounted to rotate about an axis of rotation connected to a drive shaft rotating about the same axis of a transmission line of the electromechanical service brake and the locking device.

[0010] A locking plunger is axially movable along a sliding axis between a first position in which the locking plunger releases the locking wheel and a second position in which the locking plunger locks the locking wheel. The locking plunger includes at least one marking segment that cooperates with the position determination device to determine the position of the locking plunger. Disadvantages of prior art

[0011] Prior art solutions present a space-related problem and do not allow for optimal integration of the main brake and the parking brake. The brake caliper is positioned on the vehicle to exert pressure via the brake pads on the brake disc, clamping the brake disc. It must be highly robust while occupying a limited volume to allow for its seamless integration. Solution provided by the invention

[0012] To address this space constraint, the present invention relates to an electromechanical braking module incorporating an electric drive system for a brake caliper, comprising a housing containing a main motor, the rotating shaft of which has a coupling means with a transmission element of the brake caliper, and an electric actuator controlling a locking system that immobilizes an element fixed to the shaft of said main motor. The braking system according to the invention comprises a single printed circuit board arranged in a plane perpendicular to the axis of the main motor, the coils of said main motor being electrically and mechanically connected to said printed circuit board. The median plane of the locking system is located between the plane of the printed circuit board and the plane of the front surface of the stator head of the main motor, closest to said printed circuit board.The element attached to the shaft of the main motor and the drive means for said transmission member of the caliper are located on either side of the stator cylinder head of said main motor.

[0013] The element attached to the shaft of said main motor, which is immobilized by the locking system, is a ratchet wheel, said locking system comprising a locking bar engaging in said ratchet wheel to ensure its immobilization.

[0014] The locking bar is engaged in a moving part in translation by a screw-nut transformation in cooperation with an axis driven by a secondary electric motor.

[0015] According to one variant, the entire locking system actuator is disposed between the transverse plane of the printed circuit board and the plane of the front surface of the stator cylinder head.

[0016] Advantageously, the coils of said locking actuator are also electrically and mechanically connected to said printed circuit board.

[0017] Preferably, the shaft of said main motor rotor is provided with a target mounted between the median plane of said locking system and said printed circuit board.

[0018] According to a particular embodiment, said target has magnetic indexing and said printed circuit board is equipped with a magnetosensitive sensor disposed opposite said target,

[0019] Alternatively, the target is secured to said element which is secured to the axis of said main motor.

[0020] According to a particular embodiment, the electric actuator of the locking system is a geared motor comprising a mechanism for transforming the rotary motion of an electric motor into a linear displacement motion of said locking bar.

[0021] Preferably, the electric actuator controlling said locking system is disposed between the transverse plane of the printed circuit board and the median longitudinal plane of said stator cylinder head of said main motor.

[0022] According to specific variants:

[0023] - the printed circuit board includes a position sensor disposed opposite a target fixed on said moving part of said locking system

[0024] - the locking system comprises a spring disposed between said moving part and said locking bar, to push said locking bar in the direction of said ratchet wheel

[0025] - the module further comprises a force sensor supplying said circuit electronic information based on the force exerted on the brake pads.

[0026] Detailed description of a non-limiting example of embodiment

[0027] The present invention will be better understood upon reading the following description, concerning a non-limiting example of an embodiment illustrated by the accompanying drawings where:

[0028] [Fig-1] [Fig.1] represents an exploded view of a braking module electromechanical according to the invention,

[0029] [Fig.2] [Fig.2] represents a schematic view of a braking module according to the invention,

[0030] [Fig.3] [Fig.3] represents a side view of the braking module according to the embodiment shown in [Fig.1],

[0031] [Fig. 4] [Fig. 4] shows an exploded perspective view of the brake locking system according to the embodiment presented in [Fig. 1]. General principle of the invention

[0032] The invention relates to a braking module integrating the functions of service brake, progressive braking by a caliper activated by a main electric motor (100), and a locking system (400), motorized by an electric actuator (200), ensuring the parking brake function, by means of a ratchet wheel (450).

[0033] To reduce the transverse bulk and allow optimal integration on the car chassis, this module according to the invention provides for the arrangement of all the electromechanical components (100, 200, 400) in the volume of the housing (700) between the transverse bottom (710) of the housing (700), caliper side, and a single printed circuit board (500), the housing (700) being closed on the side opposite the bottom by a cover (800).

[0034] The main motor (100) is electrically and mechanically connected to this printed circuit board (500) by terminals (190). The locking system (400) has a median transverse plane (930), parallel to the plane (920) of the printed circuit board (500), and located between said plane (920) of the printed circuit board (500) and the plane (910) of the front surface of the stator head (120) of the main motor (100) facing the electronic board (500). Preferably, the locking system (400) interacts with the ratchet wheel (450) by means of a locking bar (230) driven in translation by the electric actuator (200). This locking bar (230) has a target (350) moving in relation to a position sensor (530) attached to the printed circuit board (500), and preferably directly soldered to the latter, to provide information on the actual position of the locking bar (230).The electric actuator (200) is also electrically and mechanically connected to the printed circuit board (500) by terminals (290).

[0035] The distal end of the main motor rotor (100) is provided with another target (300) placed opposite another sensor (520) attached to the same printed circuit board (500), and also preferably directly soldered to the latter, to provide information on the angular position of the rotor (110) causing the movement of the caliper.

[0036] Geometric positioning of the module components

[0037] The relative positioning of the components is illustrated by Figures 2 and 3, [Fig.2] representing a schematic cross-sectional view of a module according to the invention and [Fig.3] representing more particularly a side view of the embodiment shown in [Fig.1].

[0038] The housing (700) is made of a molded part, for example of plastic, and has a substantially cylindrical protrusion (710) in which the main motor (100) is housed. The bottom (711) of this cylindrical protrusion (710) is traversed by the shaft (115) of the rotor (110) of the main motor (100), to allow its coupling with the mechanical elements of the caliper ensuring the transfer of power to the jaws by means of a motion transformation mechanism.

[0039] Optionally, the housing (700) is made by overmolding the stator (120) of the main motor (100).

[0040] The shaft (115) of the motor rotor (100) has two bearings (116, 117). The rear bearing (116), located on the side of the shaft interfacing with the yoke, is inserted into a housing provided on the bottom (711) of the protrusion (710) of the housing (700). The front bearing (117) is housed in a support (118), preferably an overmolded plastic support, which is inserted into another housing (712) on the front face of the protrusion (710) of the housing (700), in which the stator (120) is housed, and which is then secured by welding, gluing, screwing or any other method known to those skilled in the art.

[0041] Optionally, the rear bearing (116) is replaced by a plain bearing, the shaft then being directly guided by the bearing (117), and said plain bearing.

[0042] The housing (700) further includes a secondary housing (720) to accommodate the components providing the EPB parking brake function, and in particular the electric actuator (200). It also includes an additional housing (740), on the side opposite the protrusion (710), to receive the large electronic components soldered onto the lower surface of the printed circuit board (500), for example, the capacitors.

[0043] The peripheral wall (760) of the housing (700) has shoulders (765) having screw holes for positioning and fixing the printed circuit board (500).

[0044] The housing (700) is closed on the opposite side of the bottom (750) and the shaft exit by a cover (800). This cover (800) may, but is not limited to, be metallic to also provide a cooling function for the electronic components soldered onto the upper surface of the printed circuit board (500).

[0045] The housing (700) also includes a connector (730), placed in the described example on the peripheral wall (760), but which could also extend from the bottom (750) of the housing or be associated with the cover (800).

[0046] In sagittal (transverse-longitudinal) section illustrated by [Fig. 2], the printed circuit board (500) is positioned in the upper part of the housing (700), just below the cover (800), all the mechanical components being located in the lower part of the housing (700), below the printed circuit board (500).

[0047] All interaction functions between the electronics and the electromechanical components are ensured from the lower surface of the printed circuit (500).

[0048] In particular: - The angular position of the rotor (110) is read by a sensor (520) soldered to the underside of the printed circuit board (500), opposite the target (300). In the example described, the target (300) is a diametrically magnetized disc magnet mounted on the front end of the rotor shaft (115). The sensor (520) in this case is a magnetosensitive probe, typically a Hall effect probe. - The linear position reading of the locking bar (230) is ensured by a sensor (530) soldered to the lower surface of the printed circuit board (500), opposite the target (350). In the example described, the target (350) consists of a rotating magnet, as described in patent WO2007099238, attached to the locking bar (230). The sensor (530) in this case consists of a magnetosensitive probe, typically a Hall effect probe. - The power supply to the coils (150) of the main motor (100) is provided by "pressfit" type lugs (190) (trade name) inserted into conductive holes in the printed circuit board (500). - The power supply to the electric actuator (200) is provided by "pressfit" type lugs (290) (trade name) inserted into conductive holes in the printed circuit board (500). - The power supply and reading of signals from a force sensor connected to a connector (735) housed in the bottom (711) of the housing (700) is ensured by "pressfit" type lugs (290) (trade name) inserted into conductive holes in the printed circuit board (500).

[0049] Furthermore, the grounding of the stator (120) of the main motor (100) is ensured by a bore provided in the stator lamination block, in which a pin (196) is housed, the front head of which bears against a metallic elastic element (195) welded to a conductive track of the printed circuit board (500). Positioning the printed circuit board (500) compresses the elastic element (195) against the end of the pin (196), ensuring proper electrical conductivity between the conductive track and the stator lamination block (120).

[0050] In order to make the system very compact, the locking system (400) is arranged between the electronic board (500) and the main motor (100) and is suitable for to engage with the ratchet wheel (450) carried by the shaft (115) of the main motor (100). More specifically, the shaft (115) carrying the rotor (110) extends beyond the plane of the front surface (910) of the stator lamination stack (120) in the direction of the electronic board (500), and its end carries a target (300) cooperating with a position sensor (520) welded to the surface of the electronic board (500) to measure the angular position of the rotor (110). The ratchet wheel (450) is supported by the protruding portion of the shaft (115) located between the front surface (910) and the target (300). The locking system (400) has a median plane (930), this median plane (930) being located between the front surface (910) of the stator head (120) and the transverse plane (920) of the printed circuit board (500).More specifically, the electric actuator (200) driving the locking system (400) is entirely located between the front surface (910) of the stator head (120) and the transverse plane (920) of the printed circuit board (500). In an even more advantageous configuration, the entire locking system (400) is located between the front surface (910) of the stator head (120) and the transverse plane (920) of the printed circuit board (500).

[0051] Detailed operation of the locking system (400)

[0052] Figure 4 shows an exploded view of a locking system (400) for the main motor (100), which, in conjunction with the ratchet wheel (450), provides the parking brake function. The electric actuator (200) of the locking system (400), in the form of a secondary electric motor with a motion converter, is integrated into a secondary housing (790) that is attached to the main housing (700). This secondary housing (790) has two parts: the upper part (791), located on the side of the electronic board, is preferably made of plastic by overmolding the stator (220) of the secondary motor; the lower part (792) is preferably made of molded plastic and accommodates the moving parts before assembly with the upper part (791) of the secondary housing (790).The housing includes a wound stator (220) positioned beneath the printed circuit board (500), the coils (250) being electrically connected to the printed circuit board (500) by terminals (290). This stator (220) has a transverse plane parallel to the plane (920) of the printed circuit board (500) and drives the rotation of a rotor (210) oriented perpendicular to the plane of the printed circuit board (500). The rotor (210) has a worm gear (211) driving a pinion (212) mounted on a longitudinal shaft (215), so as to provide an irreversible motion transformation, only the rotation of the longitudinal shaft by the rotor (210) being possible. This shaft (215) has reverse threads (213, 214) on either side of the pinion (212) that interact with nuts (240, 245). The rear nut (245) is integral with the lower part (792) of the secondary housing (790). The front nut (240) is integral with a part (260) guided in longitudinal translation by the secondary housing (790).

[0053] In the example described, this part (260) is in the form of a rectangular protrusion of the nut (240) extending in the direction of the printed circuit board (500) on one side and the main motor (100) on the other so as to provide a support for the locking bar (230). Said locking bar (230) has a nose (231), adapted to engage in the ratchet wheel (450), and extends in the opposite direction by two legs (232, 233), each ending in a hook (234) so ​​as to form a slot (235) into which the part (260) is inserted. The locking bar (230) is guided in longitudinal translation in the upper part (791) and is stopped in longitudinal translation by the hooks (234) bearing against the part (260), itself being guided in translation and stopped longitudinally by the upper part (791).Since the opening (235) has a greater longitudinal extension than the part (260), movement in the direction of the ratchet wheel of the locking bar (230) relative to the part (260) is possible. The part (260) is also provided with a longitudinal cylindrical cavity, opening towards the front and closed at the bottom, on the side of the nut (240), this cylindrical cavity being suitable for receiving a compression spring (265), mounted in compression between the bottom of the cavity and the rear end (236) of the nose (231) of the locking bar (230). This spring (265) allows movement of the locking bar (230), when the secondary motor is not powered, so that when the locking bar (230) is engaged in the ratchet wheel (450), rotation of the ratchet wheel (450) in a direction ensuring clamping of the caliper is possible, but rotation in the direction of loosening is prohibited.Indeed, the tooth profile of the ratchet wheel (450) generates a longitudinal force capable of moving the locking bar (230) when the ratchet wheel (450) rotates in the direction of caliper clamping. Conversely, the force exerted by the teeth in the opposite direction causes the nose (231) of the locking bar to abut tangentially against a tooth, thus blocking rotation. During rotation in the caliper clamping direction, the spring (265) allows the nose (231) of the locking bar (230) to re-engage with the ratchet wheel (450) as each tooth passes. This spring therefore also ensures that the bar abuts against a tooth regardless of the position of the ratchet wheel (450) when the locking bar (230) reaches the engaged position, this position being determined by the position sensor consisting of a target (350) and a probe (530).Indeed, in the engaged position, the compressive force of the spring keeps the nose (231) always in frontal contact with the ratchet wheel (450) and thus prevents rotation in the loosening direction of more than one tooth.

[0054] The secondary motor is arranged in its housing so that its stator (220) is located on the printed circuit board side (500) and the worm gear driven by the rotor (210) is located on the opposite side.

[0055] The upper part (791) of the secondary housing (790), located opposite the printed circuit board (500), has a light (793) through which a magnet serving as a target (350) passes, mounted rigidly on the locking bar (230) and extending over the entire travel of said locking bar (230), allowing, by cooperation with a probe (530) soldered onto the electronic board, to provide information on the absolute position of the locking bar (230) to verify its state of engagement in the ratchet wheel (450).

[0056] The upper part (791) of the secondary housing (790) preferably has three slots (795) opposite the rotor (210) for positioning three magneto-sensitive probes, soldered to the lower part of the printed circuit board (500), necessary for driving the secondary motor. Driving with three probes is a computationally inexpensive solution, but any type of driving remains compatible with the invention, as long as the locking system ensures reliable and controlled engagement of the locking bar (230) in the ratchet wheel (450).

[0057] Grounding of the secondary motor stator is achieved by means of a bore provided in the stator lamination stack (220), in which a compression spring (295) is housed. The front end of this spring bears against a conductive track of the printed circuit board (500) at one of its longitudinal ends, and at its other end against an inclined plane (799) of the lower part (792) of the secondary housing (790). Positioning the printed circuit board (500) compresses the spring (295), and its contact with the inclined plane (799) of the housing induces a transverse displacement of the spring, thus forcing it into contact with the stator bore (220). Alternatively, the transverse expansion of the spring (295) during compression could also be used to ensure good electrical contact with the stator bore (220). Alternative embodiments

[0058] The illustrated examples are in no way limiting of the invention, and it is specifically envisaged that, in variants not shown, the position sensors may be inductive, capacitive, magnetoresistive, optical, or any other type of position sensor known to those skilled in the art. It is also envisaged that the locking system may be a solenoid-type linear actuator or a rotary system, the essential characteristic being that this locking system is disposed between the electronic board and the median plane of the main motor's stator.

Claims

Demands

1. An electromechanical braking module incorporating an electric drive system for a brake caliper, comprising a housing (700) containing a main motor (100), the rotary axis (115) of which has a coupling means with a transmission element of the brake caliper, and an electric actuator (200) controlling a locking system (400) immobilizing an element integral with the axis of said main motor (100), characterized in that said braking system comprises a single printed circuit board (500) disposed in a plane perpendicular to the axis of the main motor (100), the coils (150) of said main motor (100) being electrically and mechanically connected to said printed circuit board (500), and in that the median plane (930) of said locking system is disposed between the plane (920) of said printed circuit board (500) and the plane of the front surface (910) of the stator head (120) of said main motor (100)the closest to said printed circuit board (500) and in that said element integral with the shaft of said main motor (100) and said drive means of said caliper transmission member are located on either side of the stator head of said main motor (100).

2. Electromechanical braking module according to claim 1 characterized in that the element integral with the shaft of said main motor (100) immobilized by the locking system (400), is a ratchet wheel (450), said locking system (400) comprising a locking bar (230) engaging in said ratchet wheel (450) to ensure its immobilization.

3. Electromechanical braking module according to claim 2 characterized in that said locking bar (230) is engaged in a moving part (260) in translation by a screw-nut transformation in cooperation with an axis (215) driven by a secondary electric motor.

4. Electromechanical braking module according to claim 1 characterized in that the entire locking system actuator (400) is disposed between the transverse plane (920) of the printed circuit board and the plane of the front surface (910) of the stator cylinder head.

5. Electromechanical braking module according to claim 1 characterized in that the coils (250) of said locking actuator (200) are also electrically and mechanically connected to said printed circuit (500).

6. Electromechanical braking module according to claim 1 characterized in that the shaft of said rotor (110) of the main motor (100) is provided with a target (300) mounted between the median plane (930) of said locking system (400) and said printed circuit board (500).

7. Electromechanical braking module according to the preceding claim characterized in that said target (300) has magnetic indexing and in that said printed circuit board is provided with a magnetosensitive sensor (520) disposed opposite said target (300),

8. Electromechanical braking module according to claim 1 characterized in that said target (300) is fixed to said element fixed to the shaft of said main motor (100).

9. Electromechanical braking module according to claim 3 characterized in that said electric actuator (200) of said locking system (400) is a geared motor comprising a mechanism for transforming the rotary motion of an electric motor into a linear displacement motion of said locking bar (230).

10. Electromechanical braking module according to claim 1 characterized in that said electric actuator (200) controlling said locking system (400) is disposed between the transverse plane (920) of the printed circuit board (500) and the median longitudinal plane of said stator cylinder head of said main motor (100).

11. Electromechanical braking module according to claim 3 characterized in that said printed circuit board comprises a position sensor (530) disposed opposite a target (350) fixed on said moving part (260) of said locking system (400).

12. Electromechanical braking module according to claim 3 characterized in that said locking system (400) comprises a spring (265) disposed between said moving part (260) and said locking bar (230), to push said locking bar (230) in the direction of said ratchet wheel (450).

13. Electromechanical braking module according to claim 1 characterized in that it further comprises a force sensor providing the electronic circuit with information based on the force exerted on the brake pads.

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