CN116472210A - Electronic device for selecting and commanding an electrical signal to actuate an electrically actuated brake caliper of a parking brake system - Google Patents

Abstract

The invention relates to an electronic device (30) for selecting and routing an electrical signal for actuation of an electrically actuated brake caliper of a vehicle, in particular of a parking brake device (100) of a motor vehicle. The device comprises: -a first input (IN 1) and a second input (IN 2) for receiving electrical signals (S1, S2) for actuating an electrically actuated brake caliper; -a first output (OU 1) and at least a further first output (OU 1') connected to a first electrically actuated brake caliper (10) comprising at least two electric motors; -a second output (OU 2) and at least a further second output (OU 2') connected to a second electrically actuated brake caliper (20) comprising at least two electric motors. The device comprises electronic connection means (SW 1, SW2, SW3, SW 4) which can be controlled to assume an off-state and an on-state. When the parking brake apparatus is deactivated, the electronic connection means is controlled to assume an off state, thereby isolating the first and second inputs from the above-mentioned outputs; when the parking brake apparatus is activated, the electronic connection means is selectively controlled to switch from an off state to an on state, thereby connecting the first and second inputs to either: a first output, a second output, at least a further first output and at least a further second output. Thus, the electrical actuation signal is routed to a selected motor of the electrically actuated brake caliper.

Description

Electronic device for selecting and commanding an electrical signal to actuate an electrically actuated brake caliper of a parking brake system

Technical Field

The present invention relates to the field of electric brakes, and in particular to the field of Electric Parking Brakes (EPBs) of vehicles, and even more particularly to the field of electric parking brakes of motor vehicles. More particularly, the invention relates to an electronic device for selecting and routing an electrical signal for actuating an electronically actuated brake caliper of a brake apparatus, in particular a parking brake of a motor vehicle, even more particularly a motor vehicle.

Background

As is well known, braking systems are mainly used for two purposes: service braking and parking braking. The term "service brake" means any action on the brake system to apply a brake or slow down to a moving vehicle that produces an adjustable vehicle deceleration and is reversible, i.e., by removing a command, the action is cancelled. On the other hand, the term "parking brake" means a braking action that immobilizes the vehicle, which braking action, even after the command is removed, generates a force suitable for preventing the vehicle from moving. Such braking action is of an irreversible type and removal of this force preventing movement of the vehicle requires a specific release command. Both brake types may be activated upon command of the driver or other driver assistance system.

Currently, electric Parking Brakes (EPBs) are applied to motor vehicles, in particular automobiles, to keep the vehicle stationary on a slope and a flat road. In the past, manual park brakes have been used to achieve the same function.

Such an electric parking brake involves the use of an electrically actuated brake caliper, i.e. actuated by an electric motor dedicated to the parking brake function.

The holding mechanism of the electric parking brake of the vehicle can be activated by the driver acting on the push button. As a result of this activation, the electronic control system is configured to activate the motor positioned on the brake caliper to move the piston forward, which applies a bias to the corresponding brake pad associated with the vehicle wheel that abuts on the braking surface of the brake disc, thereby stopping the movement of the vehicle wheel. In most cases, a manual or EPB parking brake is applied to the rear axle wheels of the vehicle.

In some cases, the brake caliper for applying the parking brake action is a specially manufactured brake caliper, separate from the brake caliper for applying the service brake action. In fact, the energy involved in parking braking must be less than the energy that must be applied by service braking, due to the absence of moving objects.

Service brake calipers, which are also used as parking brake calipers, are known, as described in US3734248, US5343985, US2016167632, US5090518, US2009242338, US2014076672, US10525958 and US 2019120311.

The device for an electric parking brake EPB involves the use of an Electronic Control Unit (ECU) and an actuator adapted to act on the motor of the electrically actuated caliper. Thus, the EPB system may be considered as a subset of brake systems operating with brake-by-wire (BBW) technology.

For driving the motor to actuate the electrically actuated calipers of the EPB parking brake, it is known to use dedicated power electronic circuits, such as electronic circuits of a full bridge transistor configuration (in the case of circuit driving comprising solid state components) or electronic circuits using shunt relays (in the case of using switch driving).

In particular, the known and currently available EPB parking brake devices are made according to two different implementation types:

-the first type of parking brake comprises the use of a specific electronic control unit or ECU dedicated to the first type of parking brake, the electronic control unit or ECU comprising two power electronic circuits in a full bridge transistor configuration, each of which is usable for driving an electric motor associated with the brake caliper;

A second type of parking brake involves the use of two power electronic circuits in a full-bridge configuration, in which the transistors comprise or are integrated into an ABS/ESP control unit with which the vehicle is equipped. Likewise, each full-bridge power circuit may be used to drive a single motor associated with the brake caliper.

Recent research into new actuation solutions for electric parking brakes suitable for monolithic or floating brake calipers has devised electrically actuated calipers comprising two or more motors for each caliper, dedicated to the parking braking function.

For control purposes, this type of caliper would require a new electronic control unit capable of driving four or more motors or use a standard electronic control unit for each caliper, since currently known devices for controlling EPBs drive only two motors.

Therefore, such caliper control requires an EPB electric parking brake apparatus that is too complex and economically disadvantageous.

First, there remains a need for improved braking action, and in particular parking braking action.

Thus, there is a strong need to control electrically actuated calipers, each comprising two or more electric motors for each caliper, dedicated to the parking braking function of the vehicle, allowing to overcome the limitations and drawbacks of the known solutions described above.

When the brake caliper is also used as a parking brake caliper, it is also necessary to avoid abnormal behavior of the brake caliper. For example, it is also necessary for the caliper to have more than one motor to actuate the caliper to ensure that the action generated on the pad does not cause a "skew" of the pad itself, i.e. the action on the pad causes an abnormal movement of the pad in the seating portion of the pad provided in the caliper body, thus generating a particularly excessive asymmetric or unequal load on the brake caliper body.

Disclosure of Invention

A first object of the present invention is to devise and provide an electronic device configured to select and route electrical signals for actuating electrically actuated brake calipers of a vehicle, in particular of a parking brake device of a motor vehicle, such as a car, which allows to effectively drive electrically actuated brake calipers each comprising at least two electric motors, while limiting the complexity of the brake device.

Such object is achieved by an electronic device for selecting and routing an electrical signal for actuation of an electrically actuated brake caliper of a parking brake apparatus according to claim 1.

Specifically, an electronic device (30) for selecting and routing electrical signals includes:

-a first input (IN 1) and a second input (IN 2) for receiving electrical signals (S1, S2) for actuating an electrically actuated brake caliper;

-a first output (OU 1) connected to the first electrically actuated brake caliper (10) and at least a further first output (OU 1');

-a second output (OU 2) connected to a second electrically actuated brake caliper (20) and at least a further second output (OU 2');

-electronic connection means (SW 1, SW2, SW3, SW 4) controllable to assume an off-state and an on-state, wherein:

-when the parking brake device (100) is deactivated, said electronic connection means (SW 1, SW2, SW3, SW 4) are controlled to assume an off-state, isolating said first input (IN 1) and second input (IN 2) from the above-mentioned outputs (OU 1, OU2, OU1', OU 2');

-when the parking brake device (100) is activated, the electronic connection means (SW 1, SW2, SW3, SW 4) are selectively controlled to switch from an off-state to an on-state to connect the first input (IN 1) and the second input (IN 2) to either: a first output (OU 1), a second output (OU 2), at least a further first output (OU 1 ') and at least a further second output (OU 2'). Thus, the electric actuation signals (S1, S2) are routed to both motors of the electrically actuated brake caliper at a time.

A further object of the present invention is to be able to drive the motors of the two brake calipers of the EPB parking brake device alternately.

A further object is to be able to drive the motors of the two brake calipers for a predetermined time interval between tens to hundreds of milliseconds, to produce a more uniform forward movement of the piston.

Further objects of the invention are an EPB parking brake device according to claim 8 and a motor vehicle comprising such a device according to claim 14.

Some advantageous embodiments are the subject of the dependent claims.

Drawings

Further features and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention, given by way of non-limiting indication with reference to the accompanying drawings, in which:

fig. 1 diagrammatically shows an example of an EPB parking brake apparatus according to the invention, comprising electronics for selecting and routing electrical signals for actuating an electrically actuated brake caliper, connected between an electronic control unit of the EPB apparatus and an electrically actuated brake caliper of a motor vehicle, comprising two motors for each caliper;

fig. 2 shows a schematic diagram of the control signals of the electronic switches included in the electronic selection and routing device of fig. 1 controlling the switching over time;

Fig. 3 depicts diagrammatically a car and an extremely enlarged independent part, namely: two brake calipers, each brake calipers being monolithic, having four pistons and four independent motors, each brake calipers being associated with a respective front wheel; and, two floating brake calipers, each having only one piston and a respective motor associated with two rear wheels;

fig. 4 also diagrammatically shows a second vehicle configuration and an extremely enlarged independent part, namely: two brake calipers, each brake calipers being a floating brake calipers, having two pistons and four independent motors, each brake calipers being associated with a respective front wheel; and two floating brake calipers, each having only one piston and a corresponding motor, each floating brake caliper being associated with each rear wheel;

fig. 5 depicts an isometric view of a monolithic brake caliper associated with a brake disc, the monolithic brake caliper having four pistons driven by four independent motors;

figure 6 shows an isometric view of a floating brake caliper with two pistons driven by two independent motor reducers;

figure 7 depicts an isometric view of a floating brake caliper with a single piston driven by a motor reducer;

FIG. 8 depicts an isometric view of a hydraulic and electromechanical service and parking disc brake including a single-piece brake caliper having two hydraulically actuated pistons (service brakes) and two independent motors (parking brakes);

FIG. 9 depicts a cross-sectional view of a brake caliper for the disc brake in FIG. 8;

fig. 10 depicts an enlarged view of the detail in fig. 9.

Like or identical elements in the above-described figures are denoted by the same reference numerals.

Detailed Description

Referring to fig. 1, a simplified block diagram of a device according to the invention for a parking brake (electric parking brake or EPB) of a motor vehicle 2, in particular of a motor vehicle, is indicated as a whole by reference numeral 100.

In this specification, the term "stationary" is used to denote that the vehicle is parked and the (off) engine is turned off. In this case, the holding mechanism of the electric parking brake of the vehicle may be activated by the driver, for example, by acting on a button. After such activation, the brake calipers are actuated by the electric motor to apply the respective pads to the brake discs of the vehicle wheels, blocking them.

Also, the electric parking brake holding mechanism is deactivated by the driver by pressing the button again.

It is noted that the above-described parking brake apparatus 100 is configured to realize an electric parking brake function by using components already included in an electrically actuated brake apparatus equipped in an automobile, including an electronic control unit 50 of the brake apparatus and electrically actuated brake calipers 10, 20 acting on a brake disc of a wheel of the automobile.

In particular, in the present invention, the electrically actuated brake calipers 10, 20 of the above-described apparatus 100 may comprise one, two or more motors for each caliper. Referring to the example in fig. 1, each of the electrically actuated brake calipers 10, 20 includes two electric motors. As is well known, each such motor is adapted to actuate a respective piston (not shown in fig. 1) to tighten and release the caliper on the brake disc by acting on one or the other of the half calipers forming each brake caliper 10, 20, and vice versa.

In particular, in the example of fig. 1, the parking brake apparatus 100 comprises a first electrically actuated brake caliper 10 and a second electrically actuated brake caliper 20.

The first electrically actuated brake caliper 10 includes, for example, a first electric motor RI and at least an additional first electric motor RE. The second electrically actuated brake caliper 20 includes, for example, a second electric motor LE and at least a further second electric motor LI.

In other words, each caliper 10, 20 comprises: a first electric motor RI, LI adapted to act on a half-caliper facing the inside of the vehicle; and a second electric motor RE, LE adapted to act on a half-caliper facing the outside of the vehicle.

In an exemplary embodiment, the first and second electrically actuated brake calipers 10, 20 described above are associated with wheels of the rear axle 5 of the automobile 2.

In further exemplary embodiments, the first and second electrically actuated brake calipers 10, 20 described above are associated with wheels of the front axle 6 of the automobile 2.

These solutions are equally applicable to keeping the vehicle stationary on a slope and a flat road.

In a further different example embodiment, the first electrically actuated brake caliper 10 is associated with a wheel of the rear axle 5 of the vehicle 2 and the second electrically actuated brake caliper 20 is associated with a wheel of the front axle 6 of the vehicle 2.

Such a configuration is particularly advantageous because it allows to keep the car stationary if it is parked on uneven roads with different slopes at the wheels of the rear axle and the front axle.

Further, the parking brake apparatus 100 comprises the above-mentioned electronic control unit 50 (or ECU) comprising, for example, a microcontroller or microprocessor, configured to generate a first electrical signal S1 and a second electrical signal S2 for driving the electrically actuated brake calipers 10, 20.

In the following, we will refer generally to the aforementioned electrical actuation signals S1, S2, which means that these signals can actuate the motor (and the corresponding piston) unaffected, tightening the caliper on the brake disc, and vice versa, releasing the caliper from the brake disc.

In an exemplary embodiment, such an electronic control unit 50 is comprised in a dedicated electronic control unit comprising a first power electronic circuit CP1 and a second power electronic circuit CP2, for example, the first power electronic circuit CP1 and the second power electronic circuit CP2 in a full bridge transistor configuration, configured to generate a first electrical signal S1 and a second electrical signal S2, respectively, for actuating the electrically actuated brake calipers 10, 20.

In a further exemplary embodiment, such an electronic control unit 50 is contained in an ABS/ESP control unit with which the vehicle is already equipped. In this case, the use of a first additional power electronic circuit CP1 and a second additional power electronic circuit CP2 is included, for example in a full bridge transistor configuration, including or integrated into such an ABS/ESP control unit, and adapted to generate a first electrical signal S1 and a second electrical signal S2 for actuating the electrically actuated brake calipers 10, 20.

Furthermore, the parking brake apparatus 100 of the present invention advantageously comprises electronic means 30 for selecting and routing electrical signals for actuating the electrically actuated brake calipers 10, 20 of the apparatus.

Specifically, the electronic device 30 comprises a first input IN1 and a second input IN2 for receiving the above-mentioned first and second electric drive signals S1 and S2 generated by the electronic control unit 50.

Further, the electronic device 30 includes:

a first output OU1 and at least a further first output OU1 of the first electrically actuated brake caliper 10 connected to the first electric motor RI and at least a further first electric motor RE, respectively;

a second output OU2 and at least a further second output OU2 of the second electrically actuated brake caliper 20 connected to the second electric motor LE and at least a further second electric motor LI, respectively.

In addition, the electronic device 30 of the present invention includes electronic connection devices SW1, SW2, SW3, SW4 controllable to take an off state and an on state.

Such electronic connection means SW1, SW2, SW3, SW4 are controlled to take an off state, particularly when the parking brake apparatus 100 is deactivated. Thus, the first input terminal IN1 and the second input terminal IN2 are isolated from the output terminals OU1, OU1', OU 2'.

Conversely, when the parking brake apparatus 100 is activated, the electronic connection means SW1, SW2, SW3, SW4 are selectively controlled to switch from the off state to the on state, connecting the above-described first input terminal IN1 and second input terminal IN2 of the device 30 to any of the first output terminal OU1, the second output terminal OU2, at least the further first output terminal OU1 'and at least the further second output terminal OU 2'.

Thus, the electric actuation signals S1, S2 are routed to the selected motor of the electrically actuated brake caliper.

In an exemplary embodiment provided by a non-limiting embodiment of the present invention, the above-described electronic switching device includes a first control switch SW1, a second control switch SW2, at least a third control switch SW3, and at least a fourth control switch SW4 that are controlled in terms of switching.

In particular, these electronic switches are controlled in terms of switching based on a first control signal EN1 and a second control signal EN2, which first control signal EN1 and second control signal EN2 are generated by the electronic control unit 50 and have a temporal trend, for example, as shown in fig. 2.

In the example of fig. 1, the parking brake apparatus 100 includes two calipers, and each caliper includes two motors. Thus, the selection and routing device 30 comprises a total of four electronic switches.

However, the teachings of the present invention are also applicable to the case of brake devices employing calipers, each comprising more than two motors. The person skilled in the art can modify the number and configuration of the electronic switches of the selection means 30 so that the two actuation signals S1, S2 are always routed to either two of these motors.

In the exemplary embodiment of fig. 1, the first control signal EN1 is adapted to simultaneously act on the first switch SW1 and the fourth switch SW4, and the second control signal EN2 may simultaneously act on the second switch SW2 and the third switch SW3.

In such an exemplary embodiment, when the parking brake apparatus 100 is activated:

the first switch SW1 and the fourth switch SW4 are controlled by a first control signal EN1 to switch from an off state to an on state, during a first time interval T1 the first input IN1 is connected to the first output OU1 of the device 30 and the second input IN2 is connected to at least the further second output OU2', respectively.

In this case, the second switch SW2 and the third switch SW3 are controlled by the second control signal EN2 to take an off state.

In the same embodiment, when the parking brake apparatus 100 is activated, at the end of the first time interval T1:

The first switch SW1 and the fourth switch SW4 are controlled by a first control signal EN1 to switch from an on state to an off state;

the second switch SW2 and the third switch SW3 are controlled by a second control signal EN2 to switch from an off state to an on state to connect the first input IN1 to the second output OU2 of the device 30 and to connect the second input IN2 to the at least further first output OU1', respectively, IN a second time interval T2 following the first time interval T1.

In a further exemplary embodiment, not shown in fig. 1, the first control signal EN1 may act on the first switch SW1 and the third switch SW3 simultaneously, and the second control signal EN2 is adapted to act on the second switch SW2 and the fourth switch SW4 simultaneously.

In such an exemplary embodiment, when the parking brake apparatus 100 is activated:

the first switch SW1 and the third switch SW3 are controlled by a first control signal EN1, switched from an off state to an on state, during a first time interval T1 the first input IN1 is connected to the first output OU1 of the device 30 and the second input IN2 is connected to said at least further first output OU1';

the second switch SW2 and the fourth switch SW4 are controlled to take an off state.

In the same example, when the parking brake apparatus 100 is activated, at the end of the first time interval T1:

controlling the first switch SW1 and the third switch SW3 to switch from an on state to an off state;

the second switch SW2 and the fourth switch SW4 are controlled to switch from an off-state to an on-state such that the first input IN1 is connected to the second output OU2 of the device 30 and the second input IN2 is connected to the at least further second output OU2', respectively, IN a second time interval T2 following the first time interval T1.

IN view of the above, the electronic means 30 for selecting and routing the input signals IN1, IN2 are adapted to operate as a demultiplexer on these signals.

In the above-described exemplary embodiment, referring to fig. 2, the first control signal EN1 and the second control signal EN2 are, for example, square wave signals having the same frequency but shifted from each other by 180 °.

In this case, the first time interval T1 and the second time interval T2 are equal to each other and coincide with half a period of the square wave signal.

The duration of this half period is fixed, for example, in the range of 10 milliseconds to 100 milliseconds.

In further exemplary embodiments, the first control signal EN1 coincides with the second control signal EN 2. In other words, the first switch SW1 and the fourth switch SW4 are controlled to take the on state simultaneously with the second switch SW2 and the third switch SW 3.

In this case, when the parking brake apparatus 100 is activated, the first switch SW1, the second switch SW2, the third switch SW3 and the fourth switch SW4 are controlled to be switched from the off state to the on state and simultaneously maintain the on state during a third time interval T3 (not shown in the drawing). IN this way, the first input terminal IN1 is connected to both the first output terminal OU1 and the second output terminal OU2, and the second input terminal IN2 is connected to both the at least further first output terminal OU1 'and the at least further second output terminal OU2'.

In particular, the applicant has verified that by incorporating the above-mentioned electronic device 30 for selecting and routing the electric actuation signals, it is possible to effectively drive two electrically actuated brake calipers, each comprising at least two electric motors, using the same electronic control unit 50 already provided in the electrically actuated brake control device, without excessively increasing the complexity of the braking apparatus.

Furthermore, the electronic selection and routing device 30 may be used to alternately drive the motors of any two brake calipers of the EPB parking brake apparatus. For example, the actuation of the motors RI, LI facing the inside of the vehicle may be controlled first, and then the actuation of the motors RE, LE facing the outside of the vehicle. Alternatively, the electronic selection and routing device 30 allows driving one internal motor and one external motor.

Furthermore, by means of the electronic selection and routing device 30, it is possible to drive the motors of the same caliper at the same time and then drive the motors of the other caliper.

Furthermore, the electronic selection and routing device 30 allows to drive the motors of the two brake calipers for a time interval of preset duration T1, T2 between tens to hundreds of milliseconds. Thus, a more uniform forward movement of the piston can be produced.

The invention also relates to a motor vehicle comprising an electrically actuated brake apparatus 100 according to any of the above embodiments.

The above-described electronic control unit 50 is stored in a corresponding memory application software configured to implement the method of the control logic of the present invention. Such application software is realized in particular by means of functional blocks.

In an exemplary embodiment, the parking brake method of the vehicle 2 includes the steps of:

-providing at least one first electrically actuated brake caliper 10 associated with a first wheel 3 of the vehicle 2;

-providing at least a second electrically actuated brake caliper 20 associated with a second wheel 4 of the vehicle 2;

-providing an electronic device 30 for selecting and transmitting an electrical signal, the device comprising:

-a first input IN1 and a second input IN2 for receiving electrical signals S1, S2 for actuating the electrically actuated brake calipers 10, 20;

A first output OU1 and at least a further first output OU1 of the at least first electrically actuated brake caliper 10 connected to the first electric motor RI and to the at least further first electric motor RE, respectively;

a second output OU2 and at least a further second output OU2 of the at least second electrically actuated brake caliper 20 connected to the second electric motor LE and to at least a further second electric motor LI, respectively.

The method is characterized in that the method comprises the further step of: the above-mentioned electric actuation signals S1, S2 are selectively routed by the electronic device 30 to at least two of the first output OU1, the second output OU2, at least the further first output OU1 'and at least the further second output OU2' to activate the motors of both the at least first brake caliper 10 and the at least second brake caliper 20 to generate a parking braking action for the vehicle 2.

In an exemplary embodiment, the method further comprises the steps of:

applying an at least temporary parking brake action using at least a first electric motor RI and at least a further first electric motor RE of the first electrically actuated brake caliper 10, at least a second electric motor LE and at least a further second electric motor LI of the second electrically actuated brake caliper 20;

Generating a parking brake action for the vehicle 2 using at least one of the first electric motor RI, at least the further first electric motor RE, the second electric motor LE and at least the further second electric motor LI, to apply a continuous parking brake action, i.e. until the user deactivates the continuous parking brake action.

In an exemplary embodiment, the method includes:

defining a first amount of temporary braking action F1, i.e. a first braking force;

defining a second amount of continuous braking action F2, i.e. a second braking force.

The first amount of such temporary braking F1 is smaller than the second amount of continuous braking action F2.

In an exemplary embodiment, the step of applying the at least temporary parking brake effect comprises the further step of:

-during a first time interval T1, activating the first RI and at least the second electric motor LI to apply a first amount of said temporary braking action F1 to the first and second electrically actuated brake calipers 10 and 20;

during a first time T1, keeping at least the further motor RE and the second motor LE inactive;

-during a second time interval T2, subsequent to the first time interval T1 and equal to the first time interval T1, activating at least the first electric motor RE and the second electric motor LE, applying a first amount of temporary braking action F1 to the first electrically actuated brake caliper 10 and the second electrically actuated brake caliper 20;

During a second time T2, the first electric motor RI and at least the further electric motor LI remain deactivated.

In an embodiment, the step of applying a continuous parking brake action comprises the further step of: at least one of the aforementioned first electric motor RI, at least the further first electric motor RE, the second electric motor LE, and at least the further second electric motor LI is activated to apply a second amount of the continuous braking action F2 to the first electrically actuated brake caliper 10 or to the second electrically actuated brake caliper 20 or to both the first electrically actuated brake caliper 10 and the second electrically actuated brake caliper 20 to generate a parking braking action for the vehicle 2 until deactivated by the user.

Furthermore, a release of the only temporary parking brake action from the electric motor is provided, and the continuous parking brake action is not involved.

With reference to fig. 8, 9 and 10, examples of hydraulic and electromechanical formation and parking disc brake 200 including a single-piece brake caliper 101 are described. The brake caliper 101 comprises two pistons actuated by two motors 117, which motors 117 are controlled by an electronic control unit 120. The electronic control unit 120 essentially corresponds to the electronic unit 50 described above, and the motor 117 can be controlled by the electronic routing device 30 proposed by the present invention.

Although a single-piece hydraulic and electromechanical disc brake caliper 101 with two motors is shown in fig. 8, the invention can also be advantageously applied to hydraulic and electromechanical disc brake calipers with a greater number of pistons, for example four or six pistons, and possibly with a correspondingly greater number of electric actuating motors.

The hydraulic and electromechanical service and parking disc brake 200 comprises a caliper 101, the caliper 101 having two side walls 102 which delimit a disc space 103 with each other for accommodating a portion of a brake disc 104.

Further, the disc brake 200 comprises means for fixing the caliper 101 to the vehicle suspension and two pads 105 each supporting one of the side walls 102 accordingly.

The disc brake 200 includes a service brake system 106 having one hydraulic actuator 107 located in each side wall 102. Each of the two hydraulic actuators 107 shown in fig. 9 includes: a hydraulic cylinder 108 formed in the side wall 102, and a piston 109 is housed in the hydraulic cylinder 108 and has a free end 110 facing the pad 105.

Such a hydraulic cylinder 108 communicates with a system 111 for supplying pressurized hydraulic fluid, thereby applying hydraulic pressure to the piston 109 and translating the piston 109 in an actuation direction 112 towards the brake disc 104 and bringing the pads 105 against the brake disc 104.

Furthermore, the disc brake 200 comprises a service brake system 113, which service brake system 113 has an electromechanical actuator 114 in each side wall 102, respectively. The caliper 101 includes two electromechanical actuators 114.

Each electromechanical actuator 114 comprises a screw-nut screw assembly 115, 116, the screw-nut screw assemblies 115, 116 having a rotary member 116 and a translational member 115 and being configured to convert a rotary motion of the rotary member 116 into a translational motion of the translational build 115.

The screw nut assemblies 115, 116 are connected within the hydraulic cylinder 108 such that the translating member 115 translates and tightens against the piston 109 in the actuation direction 112, locking the piston.

The two motors 117 of the disc brake 200 are each connected to a power source 118 to actuate the screw-nut-screw assemblies 115, 116 associated with each piston. The disc brake 200 further comprises a transmission 119 connected between the motor 117 and the rotating member 116.

Notably, the electromechanical actuator 114 is self-locking due to its irreversibility of transmission, and therefore, when the motor 117 is off, the translational bias of the translating member 115 cannot move the translating member 115 rearward from the brake disc 104.

According to alternative embodiments, for example, if the caliper and the so-called floating caliper, the parking brake system 113 may comprise a single electromechanical actuator 114 located at only one side wall 102, which can be activated to block the pads 105 against the brake disc 104. In this case, a single electromechanical actuator 114 may be configured as described above.

The electronic control unit 120 of the disc brake 200 is connected to the service brake system 106 and to the parking brake system 113 and the user interface 121. Such user interfaces 121 include, for example: a user interface 122 having, for example, a service brake control interface, such as a service pedal or a service button or a service lever, and a parking brake control interface 123, such as a parking pedal or a parking button or a parking lever.

Such a control unit 120 may comprise an electrical, electromechanical, electro-hydraulic and/or electronic control system adapted to control the pressurization of the hydraulic fluid and the actuation of the electric motor 117. Such a control unit 120 is configured and/or programmed to perform control functions for the brake 200 in a desired manner.

In the case of the hydraulic and electromechanical service and parking disc brake 200 in fig. 8-10 comprising the brake caliper 101, a step of defining a pressure target value in the hydraulic circuit of the caliper 101 is provided before the above-described control step.

Notably, the hydraulic pressure may be generated by a hydraulic modulator on the vehicle, such as a stability control (ESC) modulator or an electric brake or an electro-hydraulic actuator hydraulically connected to the caliper.

In particular, in response to a parking brake user command, the control unit 120 is configured to actuate:

service brake system 106, moving piston 109 in actuation direction 112 towards brake disc 104 to a parking position in which the piston abuts pad 105 against brake disc 104, and

a parking brake system 113 for locking the piston 109 in the parking position and preventing a return movement of the piston 109.

In response to the parking brake user command, the control unit 120 is configured to:

actuating the service brake system 106 by moving the piston 109 to a parking position in which the piston pushes the pad 105 against the brake disc 104;

when the target pressure is reached in the hydraulic circuit of the caliper 101, after actuation of the running brake system 106 and with the piston 109 already in the parking position, the motor 117 is actuated in the forward direction, locking the piston in the parking position and preventing the return movement of the piston by translating the translating member 115 against the piston 109 in the actuation direction 112;

once the piston 109 is locked in the parking position, the braking system 106 is deactivated by reducing the pressure of the hydraulic fluid and turning off the motor 117.

Thus, the piston 109 remains locked due to the irreversibility of the transmission of the electromechanical actuator 114.

In response to a user command to release the park state, the control unit 120 is configured to:

first actuating the hydraulic actuator 107 to provide pressure on the piston 109 and unloading the screw-nut-screw assemblies 115, 116 of the electromechanical actuator 114;

-actuating the electromechanical actuator 114 to disengage the translating member 115 from the piston 109 when the screw-nut assemblies 115, 116 are unloaded;

when the translating member 115 is disengaged from the piston 109, the hydraulic actuator 107 is actuated to again reduce the hydraulic pressure and interrupt the parking.

One possible parking brake assembly according to the present invention is described below with reference to fig. 3-7.

According to a general embodiment, the parking brake assembly 1 of the vehicle 2 comprises at least a first brake caliper 10 associated with the wheels 3 of the rear axle 5 of the vehicle 2.

Furthermore, the assembly comprises at least a further first brake caliper 11 associated with the wheels 4 of the front axle 6 of the vehicle 2.

In the exemplary embodiment, all of the brake calipers 10, 11, 20, 21 of the brake system 1 of the vehicle 2 are electrically actuated brake calipers to avoid hydraulic braking devices and circuits on the vehicle 2.

In various exemplary embodiments, the brake calipers of the brake system 1 of the vehicle 2 include electrically actuated brake calipers and hydraulic and electromechanical service and parking brake calipers 101 similar to those described with reference to fig. 8-10.

Although in the exemplary embodiments mentioned below all vehicle brake calipers 2 are electrically actuated brake calipers, the features of the present invention are also applicable to hydraulic and electromechanical service and parking brake calipers 101.

There is the further advantage that said first brake caliper 10 and said further said first brake caliper 11 are also at least parking brake calipers.

According to an embodiment, the system 1 comprises an electronic control unit 50 configured to generate a first and a second electric parking command signal S1, S2 for actuating the electrically actuated brake calipers 10, 11, 20, 21.

According to an embodiment, said electrically actuated brake calipers 10, 11, 20, 21 and/or said electronic control unit 50 are configured to exert a constant parking effect on the vehicle 2 also when the vehicle is parked.

According to an embodiment, said electrically actuated brake calipers 10, 11, 20, 21 and/or said electronic control unit 50 are configured to exert a constant parking effect on the vehicle 2 also when the vehicle is parked and shut down.

According to an embodiment, each electrically actuated caliper 10, 11, 20, 21 comprises at least one electric motor RI, RE, LE, LI, 12, 13, 14, 15 acting directly or through a reducer 60 on a piston 61, the piston 61 biasing a brake pad 62, the brake pad 62 abutting a braking surface 63 of a brake disc 64 during braking action.

Alternatively, the at least one electric motor RI, RE, LE, LI, 12, 13, 14, 15 comprises a motor locking device 65 (not shown in the figures), the motor locking device 65 acting by blocking the movement of the electric motor when the electric motor RI, RE, LE, LI, 12, 13, 14, 15 is stopped with the vehicle 2; or the decelerator 60 is an irreversible decelerator, i.e. if actuated by the motors RI, RE, LE, LI, 12, 13, 14, 15, the decelerator allows movement of the piston 61 but does not allow the piston 61 to retract with the only bias of the brake pads 62 that the piston acts upon.

According to an embodiment, at least a second brake caliper 20 is associated with the wheel 3 of the rear axle 5 of said vehicle 2.

At least a further second brake caliper 21 is associated with the wheel 4 of the front axle 6 of said vehicle 2.

All four brake calipers 10, 11, 20, 21 of the brake system 1 of the vehicle 2 are electrically actuated brake calipers.

At least one of the electrically actuated brake calipers 10 or 11 of the rear axle 5 and at least one of the electrically actuated brake calipers 20 or 21 of the front axle 6 are also at least parking brake calipers of the vehicle 2.

According to an embodiment, at least two electrically actuated brake calipers 10 and 11 of the rear axle 5 and at least two electrically actuated brake calipers 20 and 21 of the front axle 6 are at least also parking brake calipers of the vehicle 2.

According to an embodiment, at least one electrically actuated caliper 10, 11, 20, 21 comprises at least two electric motors RI, RE, LE, LI, 12, 13, 14, 15.

At least one of the at least two electric motors RI, RE, LE, LI, 12, 13, 14, 15 generates a parking effect of the vehicle 2.

According to an embodiment, the rear axle 5 comprises two opposite rear wheels 3, and each rear wheel 3 cooperates with at least one electrically actuated rear axle caliper 10, 11.

Each of the electrically actuated calipers 10, 11 includes at least two motors RI, RE, LE, LI.

At least one of the at least two motors RI, RE, LE, LI of each of the electrically actuated calipers 10, 11 produces a parking effect of the vehicle 2.

According to an embodiment, said front axle 6 comprises two opposite front wheels 4, and each front wheel 4 cooperates with at least one electrically actuated front axle caliper 20, 21.

Each of said electrically actuated calipers 20, 21 comprises at least two electric motors 12, 13, 14, 15.

At least one of the at least two electric motors 12, 13, 14, 15 of each of the electrically actuated calipers 20, 21 generates a parking effect of the vehicle 2.

According to an embodiment, at least one electrically actuated caliper 10, 11, 20, 21 comprises at least two electric motors RI, RE, LE, LI, 12, 13, 14, 15.

Both of the at least two electric motors RI, RE, LE, LI, 12, 13, 14, 15 generate an at least temporary parking effect of the vehicle 2.

According to an embodiment, said front axle 6 comprises two opposite front wheels 4, and each front wheel 4 cooperates with at least one electrically actuated front axle caliper 20, 21.

Each of said electrically actuated calipers 20, 21 comprises at least two electric motors 12, 13, 14, 15.

Both of the at least two electric motors 12, 13, 14, 15 of each of said electrically actuated calipers 20, 21 generate an at least temporary parking effect of the vehicle 2.

According to an embodiment, the rear axle 5 comprises two opposite rear wheels 3, and each rear wheel 3 cooperates with at least one electrically actuated rear axle caliper 10, 11.

Each of the electrically actuated calipers 10, 11 includes at least two motors RI, RE, LE, LI.

At least two electric motors RI, RE, LE, LI of each of the electrically actuated calipers 10, 11 generate at least a temporary parking effect of the vehicle 2.

According to an embodiment, said front axle 6 comprises two opposite front wheels 4, and each front wheel 4 cooperates with at least one electrically actuated front axle caliper 20, 21.

The electrically actuated front axle calipers 20, 21 are floating calipers.

The electrically actuated front axle calipers 20, 21 each include two motors 12, 13, 14, 15.

At least one of the at least two electric motors 12, 13, 14, 15 of each of the electrically actuated calipers 20, 21 generates a parking effect of the vehicle 2.

According to an embodiment, said front axle 6 comprises two opposite front wheels 4, and each front wheel 4 cooperates with at least one electrically actuated front axle caliper 20, 21.

The front axle of the electrically actuated calipers 20, 21 is an integral caliper or is fixed relative to its support, such as a vehicle stub axle.

The electrically actuated front axle calipers 20, 21 each include two pairs of opposing motors 12, 13, 14, 15.

At least two of said motors 12, 13, 14, 15 of said two electrically actuated calipers 20, 21, arranged opposite each other, generate a parking effect of the vehicle 2.

According to an embodiment, the rear axle 5 comprises two opposite rear wheels 3, and each rear wheel 3 cooperates with at least one electrically actuated rear axle caliper 10, 11.

The electrically actuated rear axle calipers 10, 11 are floating calipers.

The electrically actuated rear axle calipers 10, 11 each include a single motor RI, RE, LE, LI.

Each motor RI, RE, LE, LI of the electrically actuated calipers 10, 11 generates a parking effect of the vehicle 2.

The procedure for activating the parking brake assembly will be described below.

According to a general embodiment, the parking brake method of the vehicle 2 includes the steps of:

-providing at least one electrically actuated first brake caliper 10 associated with a wheel 3 of a rear axle 5 of said vehicle 2;

-providing at least a further electrically actuated first brake caliper 11 associated with the wheels 4 of the front axle 6 of said vehicle 2;

avoiding hydraulic braking devices and circuits on the vehicle 2;

-applying a parking brake effect using said brake caliper 10 and said further first brake caliper 11 to generate a parking brake effect for said vehicle 2.

According to a further embodiment, the method comprises the steps of:

-providing two opposite rear wheels 4 in said front axle 6, wherein each front wheel 4 cooperates with at least one electrically actuated front axle caliper 20, 21;

-providing two opposite rear wheels 3 in said rear axle 5, wherein each rear wheel 3 cooperates with at least one electrically actuated rear axle caliper 10, 11;

all the electrically actuated calipers 20, 21 of the front axle and all the electrically actuated calipers 10, 11 of the rear axle are used to exert a parking brake effect.

According to a further embodiment, the method comprises the steps of:

-providing at least two motors RI, RE, LI, LE, 12, 13, 14, 15 for each electrically actuated caliper 10, 11, 20, 21;

-applying a parking brake effect using at least one of said at least two electric motors RI, RE, LI, LE,12, 13, 14, 15 to generate a parking brake effect for said vehicle 2.

According to a further embodiment, the method comprises the steps of:

-providing at least two motors RI, RE, LI, LE,12, 13, 14, 15 for each electrically actuated caliper 10, 11, 20, 21;

-applying an at least temporary parking brake action using said at least two electric motors RI, RE, LI, LE,12, 13, 14, 15;

-generating a parking brake effect for said vehicle 2 using at least one of said at least two electric motors RI, RE, LI, LE,12, 13, 14, 15, applying a continuous parking brake effect, i.e. until the user deactivates the continuous parking brake effect.

According to a further embodiment, the method comprises the steps of:

-providing at least two motors RI, RE, LI, LE,12, 13, 14, 15 for each electrically actuated caliper 10, 11, 20, 21;

-applying an at least temporary parking brake action using said at least two electric motors RI, RE, LI, LE,12, 13, 14, 15;

-generating a parking brake effect on the vehicle 2 using at least one of the at least two electric motors RI, RE, LI, LE,12, 13, 14, 15 to apply a continuous parking brake effect, i.e. until a user is deactivated;

Releasing only a temporary parking brake action from the electric motor RI, RE, LI, LE, 12, 13, 14, 15 without involving the above-mentioned continuous parking brake action.

According to a further embodiment, the method comprises the steps of:

-defining a first amount of temporary braking F1;

-defining a second amount of sustained braking F2;

-providing at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 for at least one electrically actuated caliper 10, 11, 20, 21;

-applying said temporary parking brake action F1 with said at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15;

-generating a parking brake action for the vehicle 2 using at least one of said at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 to apply said continued parking brake action F2, i.e. until the user is deactivated;

releasing the only temporary parking brake action F1 from the electric motor RI, RE, LI, LE, 12, 13, 14, 15 without involving the above-mentioned continuous parking brake action.

According to a further embodiment, the method comprises the steps of:

-defining a first amount of temporary braking F1;

-defining a second amount of sustained braking F2;

-wherein the first amount of temporary braking action F1 is defined as being equal to half of the second amount of continuous braking action F2;

-providing at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 for at least one electrically actuated caliper 10, 11, 20, 21;

-applying said temporary parking brake action F1 with said at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15;

-generating a parking brake action for the vehicle 2 using at least one of said at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 to apply said continued parking brake action F2, i.e. until the user is deactivated;

releasing the only temporary parking brake action F1 from the electric motor RI, RE, LI, LE, 12, 13, 14, 15 without involving the above-mentioned continuous parking brake action.

According to a further embodiment, the method comprises the steps of:

-defining a first amount of temporary braking F1;

-defining a second amount of sustained braking F2;

-providing at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 for at least one electrically actuated caliper 10, 11, 20, 21;

-applying the temporary parking brake action F1 using the at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15;

-generating a parking brake action for the vehicle 2 using at least one of said at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 to apply said continued parking brake action F2, i.e. until the user is deactivated;

Releasing the only temporary parking brake action F1 from the electric motor RI, RE, LI, LE, 12, 13, 14, 15 without involving the above-mentioned continuous parking brake action;

-at the end of parking, releasing the continuous parking brake action F2 using at least one of the at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15 until the temporary parking brake action F1 is achieved; thus (2)

-releasing said temporary parking brake action F1 using said at least two electric motors RI, RE, LI, LE, 12, 13, 14, 15.

Many modifications and adaptations to the embodiment of the electronic device for selecting and routing the electric signals for driving the electrically actuated calipers of the above-described electric parking brake apparatus may be made by those skilled in the art, or the elements may be replaced with other elements equivalent thereto, without departing from the scope of the following claims.

Reference numerals

1 brake system

2 vehicle

3 rear wheel

4 front wheel

5 rear axle

6 front axle

First electrically actuated brake caliper for 10 rear axle

11 further first electrically actuated brake calipers for rear axle

12 front caliper motor

13 front caliper motor

Additional motor for 14 front calipers

15 front caliper additional motor

Second electrically actuated brake caliper of 20 front axle

21 a further second electrically actuated brake caliper of the front axle

30 electronic device

50 electronic control unit

60 speed reducer

61 piston

62 brake pad

63 braking surface

64 brake disc

100 parking actuation device

IN1 first input terminal

IN2 second input terminal

S1 first electric signal

S2 second electric signal

CP1 first power circuit

CP2 second power circuit

OU1 first output terminal

OU1' further first output terminal

OU2 second output terminal

OU2' another second output terminal

First motor of RI first rear callipers

Additional first motor of RE first rear calipers

Second motor of LE second rear callipers

LI second rear Caliper further second Motor

SW1 electric connection device, first switch for controlling switching

SW2 electric connection device, second switch for controlling switching

SW3 electric connection device, third switch for controlling switching

SW4 electric connection device and fourth switch for controlling switching

EN1 first control signal

EN2 second control signal

T1 first time interval

T2 second time interval

100 parking brake apparatus

200 hydraulic and electromechanical service and parking disc brake

101 single-piece brake caliper

102 side wall

103 disc space

104 brake disc

105 pads

106 service brake system

107 hydraulic actuator

108 hydraulic cylinder

109 piston

110 free end

111 hydraulic fluid supply and pressurization system

112 actuation direction

113 parking brake system

114 electromechanical actuator

Translation member of 115 screw-nut screw assembly

Rotating member of 116 screw-nut screw assembly

117 motor

118 power supply

119 transmission mechanism

120 electronic control unit

121 user interface

122 service brake control interface

123 parking brake control interface.

Claims (21)

1. An electronic device (30) for selecting and routing an actuation electrical signal for an electrically actuated brake caliper of a parking brake apparatus (100) of a vehicle (2), the device comprising:

-a first input (IN 1) and a second input (IN 2) for receiving electrical signals (S1, S2) for actuating an electrically actuated brake caliper;

-a first output (OU 1) and at least a further first output (OU 1') connected to a first electrically actuated brake caliper (10) comprising at least two electric motors (RI, RE);

-a second output (OU 2) and at least a further second output (OU 2') connected to a second electrically actuated brake caliper (20) comprising at least two electric motors (LI, LE);

-an electronic connection device (SW 1, SW2, SW3, SW 4) controllable to assume an off-state and an on-state, wherein:

-when the parking brake device (100) is deactivated, the electronic connection means (SW 1, SW2, SW3, SW 4) are controlled to assume an off state, isolating the first input (IN 1) and the second input (IN 2) from the above mentioned outputs (OU 1, OU1', OU 2');

-when the parking brake device (100) is activated, the electronic connection means (SW 1, SW2, SW3, SW 4) are selectively controlled to switch from the off-state to the on-state, thereby connecting the first input (IN 1) and the second input (IN 2) to either: -a first output (OU 1), a second output (OU 2), at least a further first output (OU 1 ') and at least a further second output (OU 2'), said electric actuation signals (S1, S2) being routed to a selected motor of said electrically actuated brake caliper.

2. The electronic device (30) for selecting and routing electrical signals according to claim 1, wherein said electronic connection means comprise a first switch (SW 1), a second switch (SW 2), at least a third switch (SW 3) and at least a fourth switch (SW 4) controlled in terms of switching.

3. The electronic device (30) for selecting and routing electrical signals according to claim 2, wherein, when the parking brake apparatus (100) is activated:

-said first switch (SW 1) and at least a fourth switch (SW 4) are controlled to switch from said off state to an on state, connecting said first input (IN 1) to said first output (OU 1) and said second input (IN 2) to said at least a further second output (OU 2') during a first time interval (T1), respectively;

the second switch (SW 2) and at least a third switch (SW 3) are controlled to adopt the off state.

4. An electronic device (30) for selecting and routing electrical signals according to claim 3, wherein, at the end of said first time interval (T1):

-said first switch (SW 1) and at least a fourth switch (SW 4) are controlled to switch from said on-state to said off-state;

the second switch (SW 2) and at least a third switch (SW 3) are controlled to switch from the off state to the on state, so that during a second time interval (T2) after the first time interval (T1) the first input (IN 1) is connected to the second output (OU 2) and the second input (IN 2) is connected to the at least further first output (OU 1'), respectively.

5. The electronic device (30) for selecting and routing electrical signals according to claim 2, wherein, when the parking brake apparatus (100) is activated:

-said first switch (SW 1) and at least a third switch (SW 3) are controlled to switch from said off state to said on state, connecting said first input (IN 1) to said first output (OU 1) and said second input (IN 2) to said at least a further first output (OU 1') during a first time interval (T1), respectively;

the second switch (SW 2) and at least the fourth switch (SW 4) are controlled to adopt the off state.

6. The electronic device (30) for selecting and routing electrical signals according to claim 5, wherein, at the end of said first time interval (T1):

-the first switch (SW 1) and at least a third switch (SW 3) are controlled to switch from the on-state to the off-state;

the second switch (SW 2) and at least a fourth switch (SW 4) are controlled to switch from the off state to the on state, so that during a second time interval (T2) after the first time interval (T1) the first input (IN 1) is connected to the second output (OU 2) and the second input (IN 2) is connected to the at least further second output (OU 2'), respectively.

7. The electronic device (30) for selecting and routing an electrical signal according to claim 2, wherein, when the parking brake apparatus (100) is activated, during a third time interval (T3), the first switch (SW 1), the second switch (SW 2), at least the third switch (SW 3) and at least the fourth switch (SW 4) are controlled to switch from the off state to the on state, thereby connecting the first input (IN 1) to the first output (OU 1) and the second output (OU 2) simultaneously, and connecting the second input (IN 2) to at least the further first output (OU 1 ') and at least the further second output (OU 2') simultaneously.

8. A parking brake apparatus (100) of a motor vehicle, comprising:

-a first electrically actuated brake caliper (10) and a second electrically actuated brake caliper (20), wherein:

-said first electrically actuated brake caliper (10) comprises a first electric motor (RI) and at least a further first electric motor (RE);

-said second electrically actuated brake caliper (20) comprises a second electric motor (LE) and at least a further second electric motor (LI);

-an electronic control unit (50) configured to generate a first electrical signal (S1) and a second electrical signal (S2) to actuate the electrically actuated brake calipers (10, 20);

-an electronic device (30) for selecting and routing electrical signals according to any one of claims 1 to 7, said device comprising:

-a first input (IN 1) and a second input (IN 2) for receiving the first (S1) and second (S2) electrical actuation signals;

-a first output (OU 1) and at least a further first output (OU 1') of the first electrically actuated brake caliper (10) connected to the first electric motor (RI) and to at least a further first electric motor (RE), respectively;

-a second output (OU 2) and at least a further second output (OU 2') of the second electrically actuated brake caliper (20) connected to the second electric motor (LE) and to at least a further second electric motor (LI), respectively.

9. Parking brake device (100) of a motor vehicle according to claim 8, wherein the motor vehicle is a car and the first and second electrically actuated brake calipers (10, 20) are associated with wheels of a rear axle of the car.

10. Parking brake device (100) of a motor vehicle according to claim 8, wherein the motor vehicle is a car and the first and second electrically actuated brake calipers (10, 20) are associated with wheels of a front axle of the car.

11. Parking brake device (100) of a motor vehicle according to claim 8, wherein the motor vehicle is a car and the first electrically actuated brake caliper (10) is associated with a wheel of a rear axle of the car and the second electrically actuated brake caliper (20) is associated with a wheel of a front axle of the car.

12. The parking brake apparatus (100) of a motor vehicle according to claim 8, wherein the electronic control unit (50) comprises a first electronic power circuit (CP 1) and a second electronic power circuit (CP 2) in a full-bridge transistor configuration, the first and second electronic power circuits being configured to generate the first and second electric actuation signals (S1, S2).

13. The parking brake apparatus (100) of a motor vehicle according to claim 8, wherein:

-the first electrically actuated brake calipers comprise a first electrically actuated brake caliper (10) and a further first electrically actuated brake caliper (11) each associated with a wheel (3) of a rear axle (5) of the vehicle (2);

-the second electrically actuated brake calipers comprise a second electrically actuated brake caliper (20) and a further second electrically actuated brake caliper (21), each associated with a wheel (4) of a front axle (6) of the vehicle (2);

The first electric motor (RI) and the further first electric motor (RE) are associated with a first electrically actuated brake caliper (10) and a further first electrically actuated brake caliper (11), respectively;

the second electric motor (LE) and the further second electric motor (LI) are associated with a second electrically actuated brake caliper (20) and a further second electrically actuated brake caliper (21), respectively.

14. A motor vehicle comprising a parking brake apparatus (100) according to claim 8.

15. A parking brake method for a vehicle (2), comprising the steps of:

-providing at least a first electrically actuated brake caliper (10) associated with a first wheel (3) of the vehicle (2);

-providing at least a second electrically actuated brake caliper (20) associated with a second wheel (4) of the vehicle (2);

-providing an electronic device (30) for selecting and routing electrical signals, the device comprising:

-a first input (IN 1) and a second input (IN 2) for receiving electrical signals (S1, S2) for actuating the electrically actuated brake caliper;

-a first output (OU 1) and at least a further first output (OU 1') of said at least first electrically actuated brake caliper (10), said first output and at least further first output being connected to a first electric motor (RI) and at least further first electric motor (RE), respectively;

-a second output (OU 2) and at least a further second output (OU 2') of said at least second electrically actuated brake caliper (20), said second output and at least further second output being connected to a second electric motor (LE) and at least further second electric motor (LI), respectively;

characterized in that the method comprises the following further steps: -routing by the electronic device (30) the above-mentioned electric actuation signals (S1, S2) to any of the first output (OU 1), the second output (OU 2), at least a further first output (OU 1 ') and at least a further second output (OU 2'), so as to activate the motors of both the at least first brake caliper (10) and the at least second brake caliper (20) to generate a parking braking action for the vehicle (2).

16. The method of claim 15, further comprising the step of:

-applying an at least temporary parking brake effect using each of: -said first electric motor (RI) and at least a further first electric motor (RE) of said at least first electrically actuated brake caliper (10); and said second electric motor (LE) and at least a further second electric motor (LI) of said at least a second electrically actuated brake caliper (20);

-generating a parking brake effect for the vehicle (2) using at least one of said first electric motor (RI), at least a further first electric motor (RE), a second electric motor (LE) and at least a further second electric motor (LI), so as to apply a continuous parking brake effect, i.e. until deactivated by the user.

17. The method of claim 16, further comprising the step of:

-defining a first amount (F1) of temporary braking action;

-defining a second amount (F2) of continuous braking action;

-wherein the first amount (F1) of temporary braking action is smaller than the second amount (F2) of continuous braking action.

18. A method according to claim 17, wherein the step of applying an at least temporary parking brake effect comprises the further step of:

-during a first time interval (T1), activating the first electric motor (RI) and the at least further second electric motor (LI) so as to apply a first amount (F1) of the temporary braking action to a first electrically actuated brake caliper (10) and a second electrically actuated brake caliper (20);

-during said first time interval (T1), said at least further first electric motor (RE) and said second electric motor (LE) remain deactivated;

-activating said at least first electric motor (RE) and said second electric motor (LE) during a second time interval (T2) which is subsequent to said first time interval (T1) and which is equal to the first time interval (T1), so as to apply a first amount (F1) of said temporary braking action to a first electrically actuated brake caliper (10) and a second electrically actuated brake caliper (20);

-during said second time interval (T2), said first electric motor (RI) and said at least further second electric motor (LI) remain deactivated.

19. A method according to claim 17, wherein the step of applying a continuous parking brake action comprises the further step of:

-activating at least one of the first electric motor (RI), at least a further first electric motor (RE), a second electric motor (LE) and at least a further second electric motor (LI) to apply to the first electrically actuated brake caliper (10) or to apply to a second electrically actuated brake caliper (20) or to apply to both the first electrically actuated brake caliper (10) and the second electrically actuated brake caliper (20) a second amount (F2) of the continuous braking action, generating a parking braking action for the vehicle (2) until deactivated by the user;

releasing only a temporary parking brake action from the electric motor, without involving said continuous parking brake action.

20. Parking brake method for a vehicle (2) according to claim 15, wherein said at least first electrically actuated brake caliper (10) or at least second electrically actuated brake caliper (20) is a caliper (101) of a hydraulic and electromechanical service and parking disc brake (200);

the method comprises the following steps:

-a step of providing a definition of a target value of pressure in a hydraulic circuit of the caliper (101);

in response to a parking brake command by a user,

-actuating a service braking system (106) of a disc brake (200) to move a piston (109) associated with the caliper (101) in an actuation direction (112) towards a brake disc (104) in a parking position in which the piston brings a pad (105) against the brake disc (104), and

-actuating a parking brake system (113) for locking the piston (109) in the parking position and preventing a return movement of the piston (109).

21. Parking brake method for a vehicle (2) according to claim 20, wherein in response to a user's parking brake command, the method comprises the steps of:

-actuating the service brake system (106) by moving the piston (109) towards a parking position in which it pushes the pads (105) against the brake disc (104);

-when a target pressure is reached in the hydraulic circuit of the caliper (101), after actuation of the service brake system (106) and with the piston (109) already in the parking position, actuating the motor (117) in a forward direction, locking the piston in the parking position and preventing its return movement by translating a translating member (115) against the piston (109) in an actuation direction (112);

-deactivating the service brake system (106) by reducing the pressure of the hydraulic fluid and switching off the motor (117) after the piston (109) is locked in the parking position,

the piston (109) remains locked due to the transmission irreversibility of the electromechanical actuator (114).