Brake Feeling Simulator Device

Abstract

A brake feeling simulator device (1) for a brake system (2), the brake feeling simulator device (1) being adapted to be connected to a brake pedal (3), the brake feeling simulator device (1) comprising a thrust piston (11) and an electromechanical countermeasure device (5), the thrust piston (11) being configured to be biased in a translational direction with respect to the electromechanical countermeasure device (5) in response to actuation of the brake pedal (3), and the electromechanical countermeasure device (5) being configured to oppose the translation of the thrust piston (11).

Description

Technical Field

[0001] Technical Field to which the Invention Belongs

[0002] The present invention relates to a brake feeling simulator device for a brake-by-wire (hereinafter referred to as "BBW") type brake system of a vehicle with two or more wheels that can be operated by a driver using a brake pedal or a brake lever, and a brake system equipped with such a brake feeling simulator device.

Background Art

[0003] Background Art

[0004] In a BBW type brake system, there is a decoupling between the force and displacement applied to the brake pedal or brake lever by the driver and the brake force applied to the wheel by the caliper.

[0005] In a BBW brake system, the force and displacement applied by the driver to the brake pedal or lever are converted into an electrical signal, processed by a control unit, and used to control the operation of the caliper of the brake system.

[0006] Therefore, it is known to equip a BBW brake system with a brake feeling simulator device, which is connected to the brake pedal or lever and configured to simulate the feeling and rigidity of the brake pedal or lever of a conventional hydraulic brake system, thereby mimicking its "rigidity curve", and is called a "simulator device" for simplicity.

[0007] The "rigidity curve" refers to the relationship between the displacement along the stroke of the brake pedal or lever and the respective reaction forces applied to the brake pedal or lever by the simulator device, and thus the relationship applied to the driver by the brake pedal or lever. Generally, the rigidity curve has a first segment with low rigidity, a second segment with medium rigidity, and a third segment with high rigidity. Generally, a "harder" rigidity curve with a steeper gradient is preferred for an "aggressive" or "sporty" driving style, and a more gentle "softer" rigidity curve is preferred for a "city" or "eco" driving style.

[0008] In the prior art, the rigidity curve of the simulator device can be pre-designed based on the driver's needs, so that the brake pedal or lever has the "hardness" required by the driver.

[0009] Conventionally known simulator devices are usually configured to arrange a plurality of elastic elements, which are usually coil springs, in series or in parallel, and apply an overall reaction force that reproduces the rigidity curve of a conventional hydraulic braking system according to its tensile stress or compressive stress.

[0010] However, in a known simulator device, it is not possible to adjust the rigidity curve or the "hardness" of the brake pedal or lever unless the simulator device is completely redesigned. Therefore, a known simulator device cannot be customized or adjusted to meet the needs of different driving styles unless the simulator device is disassembled from the braking system and its components are redesigned and replaced.

[0011] Furthermore, the rigidity curve achieved by a known simulator device is mainly affected by the instability and temporal variations caused by the mechanical tolerances of a plurality of components inside the simulator device, especially the tolerances of the groups of springs and elastic elements arranged in series and in parallel inside the simulator device.

[0012] Furthermore, known simulator devices do not return haptic signals and feedback to the driver, such as the shaking of the brake pedal of a conventional braking system that occurs when the ABS intervenes. SUMMARY OF THE INVENTION

[0013] Solution

[0014] It is an object of the present invention to provide a simulator device and a braking system comprising such a simulator device, such as eliminating at least some of the drawbacks of the prior art.

[0015] In particular, it is an object of the present invention to provide a simulator device configured to allow adjustment and customization of its stiffness curve without requiring a complete redesign.

[0016] Furthermore, it is an object of the present invention to provide a simulator device that is more stable, more efficient, and less prone to mechanical degradation typical of known simulator devices.

[0017] Furthermore, it is a further specific object of the present invention to provide a simulator device configured to return haptic signals and feedback to the driver, such as the shaking of the brake pedal of a conventional braking system that occurs when the ABS intervenes.

[0018] These and other objects are achieved by a simulator device according to the independent claims and a braking system comprising such a simulator device.

[0019] The dependent claims relate to preferred advantageous embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Drawings

[0021] To better understand the invention and evaluate its advantages, the following describes its non-limiting exemplary embodiments with reference to the accompanying drawings.

[0022]

Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Figure 7

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Figure 8

[0030]

Figure 9

[0031]

Figure 10

[0032]

Figure 11

[0033]

Figure 12

[0034]

Figure 13

[0035]

Figure 14

[0036] Description of Some Preferred Embodiments

[0037] The present invention is suitable for application to a brake-by-wire (``BBW'') type brake system of a vehicle having two or more wheels that can be actuated by a driver by means of a brake pedal or a brake lever. Therefore, in this specification, unless otherwise specified, the term ``brake pedal'' means both a brake pedal of an automobile and the like and a brake lever of a motorcycle, a motor-assisted bicycle, and the like without distinction.

[0038] Furthermore, the "hydraulic fluid" is a fluid adapted to be pressurized by known pressurizing means during the operation of the brake pedal, the brake feeling simulator device, or the braking system.

[0039] Brake feeling simulator device 1

[0040] Referring to the figure, the brake feeling simulator device is generally indicated by reference numeral 1. The brake feeling simulator device 1 is adapted to be used in a braking system 2.

[0041] The brake feeling simulator device 1 is adapted to be fluidly connected to a brake pedal 3.

[0042] Desirably, the brake feeling simulator device 1 is adapted to be connected to the brake pedal 3 by hydraulic fluid.

[0043] Accordingly, the actuation of the brake pedal 3 corresponds to the pressurization of the hydraulic fluid in the brake feeling simulator device 1 and the subsequent actuation of the brake feeling simulator device 1.

[0044] The brake feeling simulator device 1 includes a thrust piston 11.

[0045] Furthermore, the brake feeling simulator device 1 includes an electromechanical reaction force device 5.

[0046] The thrust piston 11 is configured to be biased in a moving direction with respect to the electromechanical reaction force device 5 in response to the actuation of the brake pedal 3.

[0047] Desirably, the thrust piston 11 is configured to be biased with respect to the electromechanical reaction force device 5 by hydraulic fluid in response to the actuation of the brake pedal 3.

[0048] According to one aspect of the invention, the electromechanical reaction force device 5 is configured to oppose the translation of the thrust piston 11.

[0049] The brake feeling simulator device 1 configured in this way advantageously enables the adjustment and customization of the stiffness curve without the need for a complete redesign.

[0050] In fact, with the electromechanical reaction force device 5, the reaction force acting on the displacement of the thrust piston 11 caused by the operation of the brake pedal 3 can be changed and adjusted. As a result, the reaction force acting on the brake pedal 3 can be changed and adjusted, that is, the "hardness" of the stiffness curve of the brake feeling simulator device 1 can be changed and adjusted.

[0051] The high reaction force of the electromechanical reaction force device 5 against the movement of the thrust piston 11 corresponds to the high resistance to the movement of the thrust piston 11 actuated by the brake pedal 3, and thus corresponds to the high reaction force and the hard stiffness curve against the operation of the brake pedal 3.

[0052] Conversely, the low resistance of the electromechanical reaction force device 5 against the translation of the thrust piston 11 corresponds to the low resistance to the movement of the thrust piston 11 actuated by the brake pedal 3, and thus corresponds to the low reaction force and the softer stiffness curve against the operation of the brake pedal 3.

[0053] Furthermore, as an advantage, the brake feeling simulator 1 configured in this way is adapted to apply a reaction force to the brake pedal 3 against the operation of the brake pedal 3.

[0054] According to an embodiment, the electromechanical reaction force device 5 includes an electric motor 6 and a reaction force mechanism 40.

[0055] The reaction force mechanism 40 is configured to oppose the translation of the thrust piston 11.

[0056] The electric motor 6 is configured to operate the reaction force mechanism 40 such that the reaction force mechanism 40 opposes the translation of the thrust piston 11.

[0057] According to an embodiment, the reaction force mechanism 40 is an irreversible mechanism.

[0058] Advantageously, with such a configuration, when there is no operation by the electric motor 6, the reaction force mechanism 40 can perform a reverse movement. Therefore, when there is no operation by the electric motor 6, the reaction force mechanism 40 is configured to return to its stationary position.

[0059] According to an embodiment, the reaction force mechanism 40 is disposed so as to be interposed between the thrust piston 11 and the electric motor 6.

[0060]

[0061] According to an embodiment, the reaction force mechanism 40 is a screw nut screw assembly 8.

[0062] The screw nut screw assembly 8 faces the thrust piston 11.

[0063] The screw nut screw assembly 8 is coaxial with the operating shaft 13.

[0064] The screw nut screw assembly 8 is composed of a screw (9) and a nut screw 10.

[0065] The screw 9 and the nut screw 10 are connected to each other such that the relative translation of the nut screw 10 with respect to the screw 9 along the operating shaft 13 corresponds to the relative rotation of the nut screw 10 with respect to the screw 9 about the operating shaft 13.

[0066] The electric motor 6 includes a drive shaft 7 extending along the motor shaft 12.

[0067] The screw nut screw assembly 8 is connected to the drive shaft 7.

[0068] The electric motor 6 is configured to apply mechanical torque to at least one of the screw (9) and the nut screw 10.

[0069] Furthermore, the thrust piston 11 is configured to bias the screw nut screw assembly 8 in response to the actuation of the brake pedal 3.

[0070] Therefore, the thrust piston 11 moves at least one of the screw (9) and the nut screw 10 along the actuating shaft 13.

[0071] Furthermore, the electric motor 6 is configured to oppose the movement of the thrust piston 11 and the movement of at least one of the screw 9 and the nut screw 10 by applying a mechanical counter torque to the screw nut screw assembly 8.

[0072] The brake feeling simulator device 1 configured in this way makes it possible to change the stiffness curve to which a reaction force is applied in response to the actuation of the brake pedal 3.

[0073] In fact, depending on the strength of the mechanical counter torque applied by the electric motor 6 to the screw nut screw assembly 8, the brake feeling simulator device 1 applies reaction forces of different strengths to the actuation of the brake pedal 3.

[0074] The brake feeling simulator device 1 configured in this way can achieve a "soft" stiffness curve under the condition that the mechanical counter torque applied by the electric motor 6 is small. Under such conditions, the operation of the brake pedal 3, and thus the movement of the thrust piston 11 in the electromechanical reaction device 5, results in a small opposing action of the electric motor 6 against the movement of the thrust piston 11, causing the resistance by the brake feeling simulator device 1 to become small.

[0075] Conversely, the brake feeling simulator device 1 configured in this way enables the achievement of a "hard" stiffness curve under the condition that the mechanical counter torque applied by the electric motor 6 is of a larger magnitude. Under such conditions, the operation of the brake pedal 3, and thus the movement of the thrust piston 11 towards the electromechanical reaction device 5, results in a higher opposing action of the electric motor 6 against the movement of the thrust piston 11, causing the brake feeling simulator device 1 to receive a greater resistance.

[0076] As an additional advantage, the brake feeling simulator device 1 configured in this way can change the stiffness curve to which a reaction force is applied to the operation of the brake pedal 3 simply by changing the strength of the mechanical counter torque applied by the electric motor 6, without the need for redesign or replacement of the components of the simulator device.

[0077] Furthermore, the brake feeling simulator device 1 configured in this way also has the advantages of a simplified structure, less susceptibility to mechanical deterioration typical of known simulator devices, greater stability, and higher efficiency.

[0078] As a further advantage, the brake feeling simulator device 1 configured in this way can provide the driver with tactile signals and feedback such as the vibration of the brake pedal in a conventional braking system that occurs when the ABS intervenes. This is achieved by the action of an electric motor 6 configured to change the strength of the mechanical reaction torque applied to the screw nut screw assembly 8 and transmitted to the brake pedal 3 in order to obtain a desired tactile signal or vibration.

[0079] According to an embodiment, the electromechanical reaction device 5 includes a housing 16 extending along the operating shaft 13.

[0080] The housing 16 defines a housing compartment 17 therein.

[0081] The screw nut screw assembly 8 is housed inside the housing compartment 17.

[0082] Preferably, the housing 16 is substantially cylindrical and coaxial with the operating shaft 13.

[0083] According to one embodiment, the screw 9 of the screw nut screw assembly 8 is connected to the drive shaft 7 of the electric motor 6.

[0084] Therefore, the screw 9 is configured to receive mechanical torque from the electric motor 6.

[0085] The nut screw 10 of the screw nut screw assembly 8 is configured to translate along the operating shaft 13 with respect to the screw 9 and the electric motor 6.

[0086] Furthermore, the nut screw 10 is configured to translate with respect to the housing 16 but not to rotate.

[0087] The thrust piston 11 is configured to be biased against the nut screw 10, preferably by a hydraulic fluid, in response to the actuation of the brake pedal 3.

[0088] Accordingly, the thrust piston 11 moves the nut screw 10 along the actuating shaft 13.

[0089] According to this embodiment, the electric motor 6 is configured to oppose the movement of the nut screw 10 along the actuating shaft 13 by applying a mechanical counter-torque to the screw 9.

[0090] Specifically, the mechanical counter-torque applied by the electric motor 6 to the screw 9 biases the screw 9 in a rotational direction opposite to the direction in which the screw 9 rotates when the nut screw 10 moves due to the displacement of the thrust piston 11. Accordingly, the mechanical counter-torque counteracts the rotation of the screw (9) caused by the movement of the nut screw 10 displaced by the thrust piston 11.

[0091] Advantageously, the mechanical counter-torque of the electric motor 6 against the movement of the nut screw 10 achieved by the screw (9) changes the magnitude of the overall reaction force applied to the brake pedal 3 by the brake feeling simulator device 1. In particular, adjusting the strength of the mechanical counter-torque applied by the electric motor 6 adjusts the stiffness curve of the reaction force returned to the driver operating the brake pedal 3, and thus the stiffness curve of the brake feeling simulator device 1.

[0092] According to an embodiment, the screw nut screw assembly 8 and the electric motor 6 are arranged such that the actuating shaft 13 coincides with the motor shaft 12.

[0093] According to an embodiment, the electric motor 6 is arranged on the side opposite to the thrust piston 11 with respect to the screw nut screw assembly 8.

[0094] Advantageously, such a configuration ensures the integrity and structural strength of the electromechanical reaction device 5.

[0095] According to one embodiment, the nut screw 10 is arranged to face the electric motor 6 with respect to the screw 9.

[0096] According to this embodiment, the thrust piston 11 is configured to move the nut screw 10 in the direction of the electric motor 6.

[0097] Advantageously, such a configuration reduces the overall distortion that the electromechanical reaction device 5 undergoes during its operation.

[0098] According to one embodiment of the invention, the electromechanical reaction device 5 comprises a transmission 14.

[0099] The transmission 14 is interposed between the electric motor 6 and the screw nut screw assembly 8.

[0100] Preferably, the transmission 14 is a reversible transmission. For example, the transmission 14 is a planetary gear transmission, a harmonic gear or a cycloid speed reducer, or a cascade gear distribution device.

[0101] According to an embodiment, the electromechanical reaction device 5 comprises a bearing 15 interposed between the electric motor 6 and the screw nut screw assembly 8.

[0102] Preferably, the bearing 15 is a thrust type bearing. Preferably, the bearing 15 is a ball type or roller type bearing.

[0103] According to an embodiment, the screw nut 10 is movable between a stroke start position 24 located on the thrust piston 11 and a stroke stop position 25 on the opposite side of the thrust piston 11 with respect to the nut screw 10.

[0104] According to an embodiment, the electromechanical reaction force device 5 includes a first elastic element 23.

[0105] The first elastic element 23 is configured to bias the nut screw 10 toward the stroke start position.

[0106] Therefore, during the operation of the brake feeling simulator device 1, the nut screw 10 moves in the direction from the stroke start position 24 to the stroke stop position 25 by the thrust piston 11. Such movement of the nut screw 10 is opposed by the mechanical reaction torque of the electric motor 6 and the elastic force applied by the first elastic element 23. When the operation of the brake feeling simulator device 1 is interrupted, the first elastic element 23 biases the nut screw 10 to return it to the stroke start position 24.

[0107] Furthermore, the first elastic element 23 is configured to bias the electromechanical reaction force device 5 toward the stationary position of the electromechanical reaction force device 5. The stationary position means the position of the electromechanical reaction force device 5 in a state where it is not biased by the hydraulic fluid, that is, in a state where the electromechanical reaction force device 5 is not operating in response to the operation of the brake pedal 3.

[0108] Advantageously, the return of the nut screw 10 to the stroke start position 24 is facilitated by the reversible transmission 14.

[0109] According to one embodiment, the first elastic element 23 is a helical compression spring.

[0110] According to a preferred embodiment, the helical compression spring 23 is arranged coaxially with the screw (9) of the screw nut screw assembly 8.

[0111] Advantageously, such an arrangement reduces the overall dimensions of the electromechanical reaction force device 5.

[0112] According to one embodiment, the electromechanical reaction force device 5 includes a second backing body 19.

[0113] The backing body 19 is fixed inside the housing section 17 on the side opposite to the thrust piston 11 with respect to the nut screw 10.

[0114] According to the embodiment, the backing body 19 forms a stroke stop wall 26 facing the nut screw 10.

[0115] The stroke stop wall 26 defines the stroke stop position 25 of the nut screw 10.

[0116] Specifically, the stroke stop wall 26 is positioned such that the nut screw 10 moved by the thrust piston 11 abuts against the stroke stop wall 25 of the nut screw 10.

[0117] Advantageously, the backing body 19 can adjust the stroke stop for the operation of the electromagnetic reaction force device 5, thereby adjusting the stroke stop for the brake feeling simulator device 1 and the brake pedal 3.

[0118] According to the embodiment, the back body 19 is hollow in a direction parallel to the operating axis 13.

[0119] According to this embodiment, the screw 9 of the screw nut screw assembly 8 at least partially passes through the backing body 19 along the operating axis 13.

[0120] According to the embodiment, the backing body 19 preferably includes an outer peripheral wall 20 extending along the operating axis 13 and coaxial with the operating axis 13.

[0121] Furthermore, the backing body 19 includes a backing wall 21 transverse to the operating axis 13.

[0122] The backing wall 21 extends radially from the outer peripheral wall 20 and reaches the operating shaft 13.

[0123] According to one embodiment, the backing wall 21 defines a through hole 22 that is coaxial with the operating shaft 13.

[0124] The screw 9 of the screw nut screw assembly 8 extends through the through hole 22 of the backing wall 21.

[0125] The backing wall 21 forms a first backing surface 27 facing the nut screw 10 and a second backing surface 28 on the opposite side facing the electric motor 6.

[0126] According to an embodiment, the first end of the first elastic element 23 is positioned to abut against the nut screw 10, and the second end on the opposite side of the first elastic element 23 is positioned to abut against the first backing surface 27 of the backing body 19.

[0127] According to an embodiment, either the transmission 14 or the bearing 15 is arranged to abut against the second backing surface 28.

[0128] According to a preferred embodiment, the bearing 15 is arranged to abut against the second backing surface 28, and the transmission 14 is arranged to abut against the bearing 15.

[0129] According to this embodiment, the bearing 15 and the transmission 14 are at least partially, preferably entirely, housed within the backing housing 19.

[0130] Advantageously, with such a configuration, the overall dimensions of the electromechanical reaction device 5 are reduced.

[0131] According to one embodiment, the electromechanical reaction device 5 comprises a second elastic element 29.

[0132] The second elastic element 29 is interposed between the screw nut screw assembly 8 and the thrust piston 11.

[0133] The second elastic element 29 is configured to bias the screw nut screw assembly 8 in a direction away from the thrust piston 11.

[0134] According to an embodiment, the second elastic element 29 is interposed between the nut screw 10 and the thrust piston 11, and the second elastic element 29 is configured to bias the nut screw 10 in a direction away from the thrust piston 11.

[0135] Advantageously, the second elastic element 29 prevents the thrust piston 11, which has been displaced by the hydraulic fluid, from suddenly colliding with the nut screw 10 with the risk of damaging such components. Conversely, the second elastic element 29 is configured to allow movement, approach, and relative contact between the thrust piston 11 and the nut screw 10.

[0136] According to an embodiment, the second elastic element 29 is a helical compression spring.

[0137] According to an embodiment, the thrust device 11 forms a blind piston cavity. The blind piston cavity is open in the direction of the nut screw 10.

[0138] According to an embodiment, the second elastic element 29 is at least partially received within the blind piston cavity.

[0139] Advantageously, such a configuration reduces the overall dimensions of the electromechanical reaction device 5.

[0140] According to one embodiment, the first end of the second elastic element 29 is positioned to abut against the thrust piston 11 inside the blind piston cavity, and the second end on the opposite side of the second elastic element 29 is positioned to abut against the nut screw 10.

[0141] According to an embodiment, the thrust piston 11 includes a bias wall 30 that substantially crosses the operating axis 13.

[0142] Furthermore, the thrust piston 11 includes a thrust wall 31 that extends in a direction parallel to the operating axis 13 and crosses the thrust wall 31.

[0143] The thrust piston 11 is configured to receive a hydraulic fluid bias on the bias wall 30 so as to translate the thrust piston 11 toward a screw nut screw assembly 8, which is preferably a nut screw 10.

[0144] The bias wall 30 faces the transfer pipe 32.

[0145] The transfer pipe 32 is configured to fluidly connect the brake feeling simulator device 1 to the brake pedal 3 by hydraulic fluid.

[0146] Specifically, the transfer pipe 32 is configured to convey hydraulic fluid to the brake feeling simulator device 1 when the brake feeling simulator device 1 is activated and the brake pedal 3 is depressed, and to discharge the hydraulic fluid from the brake feeling simulator device 1 when the brake feeling simulator device 1 is stopped and the brake pedal 3 is released.

[0147] Preferably, the transfer pipe 32 is at least partially defined by the housing 16.

[0148] The thrust wall 31 faces the screw nut screw assembly 8 and is configured to abut against the screw nut screw assembly 8, preferably the nut screw 10, when the brake feeling simulator device 1 is operated.

[0149] According to an embodiment, the electric motor 6 is arranged to abut against the housing 16 on the side opposite to the thrust piston 11 and the conveyance pipe 32.

[0150] Advantageously, with such a configuration, the overall stress acting on the brake feeling simulator device 1 is reduced.

[0151] Brake system 2

[0152] Furthermore, according to another aspect of the present invention, the brake system 2 includes the brake feeling simulator device 1 described above.

[0153] Furthermore, the brake system 2 includes a brake pedal 3 operatively connected to the brake feeling simulator device 1.

[0154] The brake system 2 configured in this way enables the brake pedal simulator 1 to achieve a reaction force against the operation of the brake pedal 3 that follows a stiffness curve. Furthermore, such a stiffness curve can be modified and adjusted by the brake pedal simulator 1.

[0155] According to a possible embodiment, the brake system 2 includes an absorber 4 configured to apply a reaction force to the brake pedal 3 against the operation of the brake pedal 3.

[0156] In particular, the absorber 4 is configured to apply a reaction force to the brake pedal 3 against the operation of the brake pedal 3 in accordance with a stiffness curve, that is, a defined relationship between the displacement of the brake pedal 3 along the stroke and the respective reaction force applied by the absorber 4.

[0157] According to an embodiment, the brake feeling simulator device 1 is fluidly connected to the absorber 4.

[0158] Specifically, the electromechanical reaction force device 5 is fluidly connected to the absorber 4.

[0159] The absorber 4 and the electromechanical reaction force device 5 are fluidly connected by hydraulic oil.

[0160] The absorber 4 and the brake feeling simulator device 1 are operable by hydraulic fluid in response to the operation of the brake pedal 3.

[0161] The absorber 4 is an absorber of a well-known type, that is, it is configured by arranging a plurality of elastic elements, which are generally helical springs, in series or in parallel, and is configured to apply an overall reaction force that reproduces the stiffness curve of a conventional hydraulic brake system with respect to its tensile stress or compressive stress.

[0162] The brake system 2 configured in this way enables, by the combined action of the absorber 4 and the brake feeling simulator device 1, the brake pedal 3 to achieve a reaction force against the operation of the brake pedal that follows the stiffness curve. Furthermore, such a stiffness curve can be modified and adjusted by the brake feeling simulator device 1.

[0163] The stiffness curve achieved only by the absorber 4 is predetermined. Such a stiffness curve is variable and changeable by the electromechanical reaction force device 5 fluidly connected to the absorber 4 by hydraulic fluid.

[0164] Advantageously, in the brake system 2 configured in this way, the brake feeling simulator device 1 is connected to the absorber 4, and the absorber 4 can change and adjust a predetermined stiffness curve achievable on the brake pedal 3, and thus a brake system 2 with a changeable and adjustable stiffness curve can be obtained.

[0165] According to this embodiment, when the mechanical counter torque applied by the electric motor 6 is substantially zero, the reaction force applied to the brake pedal 3 substantially follows the stiffness curve of the absorber 4 itself, and the influence of the electromechanical countermeasure device 5 on the absorber 4 is only due to the inertial force of the electric motor 6 connected to the reaction force mechanism 40.

[0166] According to the embodiment, the transfer pipe 32 of the brake feeling simulator device 1 is configured to fluidly connect the brake feeling simulator device 1 to the absorber 4 by means of a hydraulic fluid.

[0167] According to the embodiment, the brake system 2 includes an electronic processing unit 18 electrically connected to the electric motor 6 of the brake feeling simulator device 1.

[0168] Furthermore, the brake system 2 includes at least one sensor configured to detect the actuation and / or movement of the brake pedal 3.

[0169] The electronic processing unit 18 is configured to operate the electric motor 6 of the electromechanical reaction force device 5 only when the actuation and / or movement of the brake pedal 3 is detected by at least one sensor.

[0170] Advantageously, such a configuration enables energy saving and stress reduction of the brake feeling simulator device 1.

[0171] According to an alternative embodiment, the electronic processing unit 18 is configured to operate the electric motor 6 of the electromechanical reaction force device 5 so as to always bias the nut screw 10 of the screw nut screw assembly 8 towards the stroke start position 24 of the nut screw 10, regardless of the actuation of the brake pedal 3.

[0172] Advantageously, with such a configuration, even the slight response delay in the brake feeling simulator device 1 due to the transmission of the actuation command from the electronic processing unit 18 to the electric motor 6 is canceled, so that the response time by the brake feeling simulator device 1 can be further shortened.

[0173] According to an embodiment, the electronic processing unit 18 is configured to command the brake feeling simulator device 1 to achieve a stiffness curve selectable from a plurality of stiffness curves.

[0174] According to this embodiment, each selectable stiffness curve corresponds to a predetermined value of the mechanical counter torque applied by the electric motor 6 to the screw nut screw assembly 8.

[0175] Alternatively, each selectable stiffness curve corresponds to a predetermined tendency of the mechanical counter torque applied by the electric motor 6 to the screw nut screw assembly 8, which changes as a function of the movement of the brake pedal 3 and / or the movement of the nut screw 10.

[0176] Advantageously, such a tendency of the mechanical counter torque applied by the electric motor 6 to the screw nut screw assembly 8, which changes as a function of the movement of the brake pedal 3 and / or the translation of the nut screw 10, is customizable based on the requirements of a specific driver, whereby a stiffness curve customized for a specific driver is obtained.

[0177] According to an embodiment, the brake system 2 is configured to obtain at least two, preferably at least three, different stiffness curves.

[0178] The stiffness curves differ in their different steepnesses, and thus in the hardness perceivable by the driver operating the brake pedal 3.

[0179] As an example, the driver can select from three different stiffness curves, for example called "Sport", "Drive", and "City", depending on the respective hardness.

[0180] According to an embodiment, the braking system 2 comprises a selection device connected to the electronic processing unit 18.

[0181] The selection device is configured such that the driver can select a stiffness curve from a plurality of predetermined stiffness curves of the brake feeling simulator device 1.

[0182] According to one embodiment, the braking system 2 comprises a master cylinder 33 connected to the brake pedal 3.

[0183] The master cylinder 33 comprises a float 34 that is moved by the driver's mechanical action on the brake pedal 3. The float 34 has the function of pressurizing the hydraulic fluid.

[0184] Furthermore, the hydraulic fluid is accommodated in a reservoir 35 that is fluidly connected to the master cylinder 33.

[0185] The master cylinder 33 is fluidly connected to the absorber 4 by a first hydraulic duct 36 that accommodates the hydraulic fluid.

[0186] According to an embodiment, a first on-off valve 37 is arranged along the first hydraulic duct 36. The on-off valve 37 can be opened and closed, and in the open state enables fluid connection between the master cylinder 33 and the absorber 4, and in the closed state blocks the absorber 4 from the master cylinder 33.

[0187] According to an embodiment, the braking system 2 further comprises a second hydraulic duct 38 operatively connected to at least one braking device associated with the vehicle's wheels.

[0188] The second hydraulic duct 38 is connected to the first hydraulic duct 36 by a second on-off valve 39.

[0189] The second on-off valve can be opened and closed in sequence. In the open configuration, the second on-off valve 39 enables the fluid connection between the master cylinder 33 and the braking device, whereby the driver can directly operate the braking device by the conventional hydraulic actuation by stepping on the brake pedal 3. In the closed configuration, the second on-off valve 39 prevents the direct hydraulic connection between the master cylinder 33 and the braking device. Accordingly, the second hydraulic pipeline functions as a backup in case of failure of the electric actuating means or power outage.

[0190] Operation method

[0191] According to a further aspect of the invention, the method of operating the above-described braking system 2 includes the following steps.

[0192] - Selecting a stiffness curve from a plurality of predetermined stiffness curves achievable by the brake feeling simulator device 1 by means of a selection device.

[0193] Detecting the actuation of the brake pedal 3 by at least one sensor.

[0194] When the actuation of the brake pedal 3 is detected, the electric motor 6 of the brake feeling simulator device 1 is actuated by the electronic processing unit 18, and the electric motor 6 preferably applies a mechanical counter torque to the screw-screw nut assembly 8 with respect to the movement of the nut screw 10.

[0195] Desirably, this method includes the following steps following the above steps.

[0196] - Detecting the interruption of the actuation of the brake pedal 3 by at least one sensor.

[0197] - When the interruption of the operation of the brake pedal 3 is detected, the electric motor 6 of the brake feeling simulator device 1 is deactivated by the electronic processing unit 18.

[0198] According to an alternative embodiment, the method of operating the brake system 2 described above includes the following steps.

[0199] - A step of selecting a stiffness curve from a plurality of predetermined stiffness curves of the brake feeling simulator device 1 by a selection device.

[0200] - A step of operating the electric motor 6 of the brake feeling simulator device 1 so that the electric motor 6 applies a mechanical reverse torque to the screw nut screw assembly 8, preferably against the movement of the nut screw 10, by the electronic processing unit 18, independently of the operation of the brake pedal 3.

[0201] Of course, those skilled in the art will be able to make changes and modifications to the present invention without departing from the scope of the following claims.

[0202] 1. Brake feeling simulator device 2. Brake system 3. Brake pedal 4. Absorber 5. Electromechanical countermeasure device 6. Electric motor 7. Drive shaft 8. Screw nut screw assembly 9. Screw 10. Nut screw 11. Thrust piston 12. Motor shaft 13. Actuating shaft 14. Transmission 15. Bearing 16. Housing 17. Housing compartment 18. Electronic processing unit 19. Backing body 20. Peripheral wall 21. Backing wall 22. Through hole 23. First elastic element 24. Stroke start position 25. Stroke stop position 26. Stroke stop wall 27. First backing surface 28. Second backing surface 29. Second elastic element 30. Bias wall 31. Thrust wall 32. Conveyor pipe 33. Master cylinder 34. Float 35. Storage tank 36. First hydraulic duct 37. First on-off valve 38. Second hydraulic duct 39. Second on-off valve 40. Counter mechanism

Claims

1. A brake feeling simulator device (1) for a brake system (2), wherein the brake feeling simulator device (1) is configured to be connected to a brake pedal (3), the brake feeling simulator device (1) comprises: a thrust piston (11); and an electromechanical countermeasure device (5), the thrust piston (11) is configured to bias the electromechanical countermeasure device (5) in a translational direction in response to the operation of the brake pedal (3), the electromechanical countermeasure device (5) is configured to oppose the translation of the thrust piston (11), the brake feeling simulator device (1).

2. The brake feeling simulator device (1) according to Claim 1, wherein the electromechanical countermeasure device (5) comprises an electric motor (6) and a countermeasure mechanism (40), the countermeasure mechanism (40) is configured to resist the translation of the thrust piston (11), the electric motor (6) is configured to operate the countermeasure mechanism (40) such that the countermeasure mechanism (40) resists the translation of the thrust piston (11), the countermeasure mechanism (40) is a reversible mechanism, the brake feeling simulator device (1).

3. The brake feeling simulator device (1) according to Claim 1 or 2, wherein the electromechanical countermeasure device (5) comprises an electric motor (6) and a countermeasure mechanism (40), the countermeasure mechanism (40) is configured to oppose the translation of the thrust piston (11), the electric motor (6) is configured to operate the countermeasure mechanism (40) such that the countermeasure mechanism (40) resists the translation of the thrust piston (11), the countermeasure mechanism (40) is a screw nut screw assembly (8) coaxial with an operating shaft (13), the screw nut screw assembly (8) comprises a screw (9) and a nut screw (10), the screw (9) and the nut screw (10) are connected to each other such that the relative translation of the nut screw (10) with respect to the screw (9) along the operating shaft (13) corresponds to the relative rotation of the screw (9) with respect to the nut screw (10) about the operating shaft (13). The electric motor (6) comprises a drive shaft (7) extending along a motor shaft (12), the screw nut screw assembly (8) is connected to the drive shaft (7), the electric motor (6) is configured to apply mechanical torque to at least one of the screw (9) or the nut screw (10), the thrust piston (11) is configured to be biased against the screw nut screw assembly (8) in response to actuation of the brake pedal (3) to move either the screw (9) or the nut screw (10) along the actuating shaft (13), the electric motor (6) is configured to apply a mechanical counter torque to the screw nut screw assembly (8) to oppose the movement of the thrust piston (11) and either the screw (9) or the nut screw (10) along the actuating shaft (13), a brake feeling simulator device (1).

4. The brake feeling simulator device (1) according to claim 3, wherein the electromechanical counter device (5) comprises a housing (16) extending along the actuating shaft (13), the housing (16) defines a housing compartment (17) inside the housing (16), the screw nut screw assembly (8) is housed within the housing compartment (17), the screw (9) of the screw nut screw assembly (8) is connected to the drive shaft (7) of the electric motor (6) such that the screw (9) receives mechanical torque from the electric motor (6), the nut screw (10) of the screw nut screw assembly (8) is configured to translate along the actuating shaft (13) relative to the screw (9) and the electric motor (6), but is configured not to rotate relative to the housing (16), the thrust piston (11) is configured to be biased against the nut screw (10) in response to actuation of the brake pedal (3) such that the thrust piston (11) moves the nut screw (10) along the actuating shaft (13), The brake feeling simulator device (1), wherein the electric motor (6) is configured to oppose the movement of the nut screw (10) along the operating shaft (13) by applying a mechanical counter torque to the screw (9).

5. The brake feeling simulator device (1) according to claim 3 or 4, wherein the screw nut screw assembly (8) and the electric motor (6) are arranged such that the operating shaft (13) coincides with the motor shaft (12), and / or, the electric motor (6) is arranged on the opposite side of the thrust piston (11) with respect to the screw nut screw assembly (8), and / or, the nut screw (10) is arranged on the opposite side of the electric motor (6) with respect to the screw (9), and the thrust piston (11) is configured to move the nut screw (10) in the direction of the electric motor (6), the brake feeling simulator device (1).

6. The brake feeling simulator device (1) according to claim 3, wherein the electromechanical countermeasure device (5) comprises a transmission (14), the transmission (14) is interposed between the electric motor (6) and the screw nut screw assembly (8), the transmission (14) is a reversible transmission, optionally, the transmission (14) is a planetary gear transmission, a harmonic reducer, a cycloid reducer, or a cascade gear reducer, and / or, the electromechanical countermeasure device (5) includes a bearing (15) interposed between the electric motor (6) and the screw nut screw assembly (8), optionally, the bearing (15) is a ball or roller thrust type bearing, the brake feeling simulator device (1).

7. The brake feeling simulator device (1) according to claim 4, wherein the nut screw (10) is movable between a stroke start position (24) located at the thrust piston (11) and a stroke stop position (25) located on the opposite side of the thrust piston (11) with respect to the nut screw (10), The electromechanical counteracting device (5) includes a first elastic element (23) configured to bias the nut screw (10) towards the stroke start position. Optionally, the first elastic element (23) is a helical compression spring. Optionally, the helical compression spring is arranged coaxially with the screw (9) of the screw nut screw assembly (8) in a brake feeling simulator device (1).

8. A brake feeling simulator device (1) according to claim 4, wherein the electromechanical counteracting device (5) comprises a backing body (19) fixed within the housing compartment (17) on the side opposite to the thrust piston (11) with respect to the nut screw (10). The backing body (19) forms a stroke stop wall (26) facing the nut screw (10). The stroke stop wall (26) defines a stroke stop position (25) of the nut screw (10). And / or The backing body (19) is hollow in a direction parallel to the actuating shaft (13). The screw (9) of the screw nut screw assembly (8) passes at least partially through the backing body (19) along the actuating shaft (13). And / or The backing body (19) comprises an outer peripheral wall (20) extending along the actuating shaft (13) and a backing wall (21) transverse to the actuating shaft (13). The backing wall (21) extends radially from the outer peripheral wall (20) towards the actuating shaft (13) and defines a through hole (22) coaxial with the actuating shaft (13). The screw (9) of the screw nut screw assembly (8) extends through the through hole (22) of the backing wall (21). Optionally, the backing wall (21) forms a first backing surface (27) facing the nut screw (10) and a second backing surface (28) on the opposite side facing the electric motor (6). A first end of the first elastic element (23) is positioned to abut against the nut screw (10). A second end of the first elastic element (23) on the opposite side is positioned to abut against the first backing surface (27) of the backing body (19). A brake feeling simulator device (1) in which a bearing (15) is arbitrarily placed in contact with the second backing surface (28), and a transmission (14) is arranged relative to the bearing (15).

9. The brake feeling simulator device (1) according to claim 3, wherein the electromechanical countermeasure device (5) includes a second elastic element (29) interposed between the screw nut screw assembly (8) and the thrust piston (11), the second elastic element (29) being configured to bias the screw nut screw assembly (8) in a direction away from the thrust piston (11), optionally, the second elastic element (29) is interposed between the nut screw (10) and the thrust piston (11), the second elastic element (29) being configured to bias the nut screw (10) in a direction away from the thrust piston (11), the second elastic element (29) being a helical compression spring, the brake feeling simulator device (1).

10. The brake feeling simulator device (1) according to claim 9, wherein the thrust piston (11) forms a blind piston cavity, the blind piston cavity opening in the direction of the nut screw (10), the second elastic element (29) being at least partially received within the blind piston cavity, optionally, a first end portion of the second elastic element (29) is positioned inside the blind piston cavity so as to abut against the thrust piston (11), a second end portion opposite to the second elastic element (29) being positioned so as to abut against the nut screw (10), the brake feeling simulator device (1).

11. The brake feeling simulator device (1) according to claim 3, wherein the thrust piston (11) includes a bias wall (30) transverse to the operating shaft (13) and a thrust wall (31) extending in a direction parallel to the operating shaft (13). The thrust piston (11) is configured to receive, on the bias wall (30), the pressure of a hydraulic fluid suitable for causing the thrust piston (11) to translate towards the screw nut screw assembly (8), preferably the nut screw (10). The bias wall (30) faces the conveyance pipe (32). The conveyance pipe (32) is configured to fluidly connect the brake feeling simulator device (1) to the brake pedal (3) by means of the hydraulic fluid. The thrust wall (31) faces the screw nut screw assembly (8) and is configured to abut against the screw nut screw assembly (8), preferably the nut screw (10), when the brake feeling simulator device (1) is in operation. Brake feeling simulator device (1).

12. A brake system (2) comprising the brake feeling simulator device (1) according to any one of claims 1 to 11. The brake system (2) includes a brake pedal (3) operatively connected to the brake feeling simulator device (1).

13. The brake system (2) according to claim 12, further comprising an absorber (4) configured to apply a reaction force to the brake pedal (3) against the operation of the brake pedal (3). The absorber (4) is fluidly connected to the brake feeling simulator device (1). And / or The absorber (4) is fluidly connected to the electromechanical countermeasure device (5) of the brake feeling simulator device (1) by means of a hydraulic fluid. Brake system (2).

14. The brake system (2) according to claim 12 or 13, Comprising an electronic processing unit (18) electrically connected to the electric motor (6) of the brake feeling simulator device (1). Comprising at least one sensor configured to detect the operation and / or movement of the brake pedal (3). The electronic processing unit (18) is configured to operate the electric motor (6) of the electromechanical countermeasure device (5) only when the operation and / or movement of the brake pedal (3) is detected by at least one sensor. Or The braking system (2), wherein the electronic processing unit (18) is configured to operate the electric motor (6) of the electromechanical counteracting device (5) so as to always bias the nut screw (10) of the screw nut screw assembly (8) towards the stroke start position (24) of the nut screw (10), independently of the actuation of the brake pedal (3).

15. The braking system (2) according to claim 14, wherein the electronic processing unit (18) is configured to control the brake feel simulator device (1) so as to execute a stiffness curve selectable from a plurality of stiffness curves, each selectable stiffness curve corresponding to a predetermined value of the mechanical torque applied by the electric motor (6) to the screw nut screw assembly (8), or each selectable stiffness curve corresponding to a predetermined trend of the mechanical torque applied by the electric motor (6) to the screw nut screw assembly (8), the predetermined trend varying as a function of the movement of the brake pedal (3) and / or the movement of the nut screw (10), the braking system (2).

16. A method of operating the braking system (2) according to claims 14 and 15, - selecting a stiffness curve from a plurality of predetermined stiffness curves achievable by the brake feel simulator device (1) using a selection device; - detecting the actuation of the brake pedal (3) by means of at least one sensor; when the actuation of the brake pedal (3) is detected, operating the electric motor (6) of the brake feel simulator device (1) by the electronic processing unit (18), the electric motor (6) applying a mechanical counter torque to the screw nut screw assembly (8), preferably in a direction opposite to the movement of the nut screw (10); and optionally detecting the interruption of the actuation of the brake pedal (3) by means of at least one sensor; when the interruption of the actuation of the brake pedal (3) is detected, deactivating the electric motor (6) of the brake feel simulator device (1) by the electronic processing unit (18), a method of operating the braking system (2) comprising these steps.

17. A method of operating a brake system (2) according to claims 14 and 15, comprising: selecting a stiffness curve from a plurality of predetermined stiffness curves of the brake feeling simulator device (1) using a selection device; operating the electric motor (6) of the brake feeling simulator device (1) by an electronic processing unit (18) such that the electric motor (6) applies a mechanical counter torque to the screw nut screw assembly (8), preferably independently of the actuation of the brake pedal (3) and in contrast to the movement of the nut screw (10).

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