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 at least one elastic element (4), a thrust piston (5) configured to be biased against the at least one elastic element (4) in response to actuation of the brake pedal (3), and an electromechanical preloading device (6) configured to apply a preload to the at least one elastic element (4).

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 brake system caliper.

[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 feel and stiffness of the brake pedal or lever of a conventional hydraulic brake system, thereby mimicking its "stiffness curve", and is called a "simulator device" for simplicity.

[0007] The "stiffness 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 stiffness curve has a first segment with low stiffness, a second segment with medium stiffness, and a third segment with high stiffness. Generally, a "harder" stiffness curve with a steeper gradient is preferred for an "aggressive" or "sporty" driving style, and a more gentle "softer" stiffness curve is preferred for a "city" or "eco" driving style.

[0008] In the prior art, the stiffness 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 usually arrange a plurality of elastic elements, which are usually coil springs, in series or in parallel, and are configured to apply an overall reaction force that reproduces the stiffness curve of a conventional hydraulic brake system according to its tensile stress or compressive stress.

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

[0011] Furthermore, the stiffness curve achieved by a known simulator device is mainly affected by the mechanical tolerances of a plurality of components inside the simulator device, particularly the instability and time-dependent variations caused by 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 tactile signals and feedback to the driver, such as the shaking of the brake pedal of a conventional braking system caused when the ABS intervenes. Summary of the Invention

[0013] Solution Means

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

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

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

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

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

[0023]

Figure 2

[0024]

Figure 3

[0025]

Figure 4

[0026]

Figure 5

[0027]

Figure 6

[0028]

Figure 7

[0029]

Figure 8

[0030]

Figure 9

[0031]

Figure 10

[0032]

Figure 11

[0033] - Description of Some Preferred Embodiments

[0034] 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 via a brake pedal or a brake lever. Accordingly, in this specification, unless otherwise specified, the term "brake pedal" is meant to include both a brake pedal of an automobile and a brake lever of a motorcycle, a motorized bicycle, etc., without distinction.

[0035] Referring to the figures, a brake feeling simulator device is generally indicated by reference numeral 1. The brake feeling simulator device 1 is adapted to be used in a brake system 2.

[0036] The brake feeling simulator device 1 is adapted to be connected to a brake pedal 3.

[0037] Preferably, the brake feeling simulator device 1 is adapted to be connected to the brake pedal 3 by hydraulic fluid.

[0038] The brake feeling simulator device 1 includes at least one elastic element 4.

[0039] Furthermore, the brake feeling simulator device 1 includes a thrust piston 5.

[0040] The thrust piston 5 is configured to be biased against at least one elastic element 4 in response to the operation of the brake pedal 3.

[0041] Desirably, the thrust piston 5 is configured to be biased against at least one elastic element 4 by hydraulic fluid in response to the operation of the brake pedal 3.

[0042] According to one aspect of the present invention, the brake feeling simulator device 1 includes an electromechanical preloading device 6.

[0043] The electromechanical preloading device 6 is configured to apply a preload to at least one elastic element 4.

[0044] The brake feeling simulator device 1 configured in this way enables adjustment and customization of the stiffness curve without requiring a complete redesign.

[0045] In fact, with the electromechanical preloading device 6, the preload of at least one elastic element 4 can be adjusted, thereby changing and adjusting the "hardness" of the stiffness curve of the brake feeling simulator device 1.

[0046] The greater the preload of at least one elastic element 4, the greater the resistance to the movement of the thrust piston 5 with respect to at least one elastic element 4. As a result, a high reaction force is obtained when the brake pedal 3 is operated, and the stiffness curve becomes hard.

[0047] Conversely, if the preload of at least one elastic element 4 is low, the resistance to the movement of the thrust piston 5 with respect to the at least one elastic element 4 becomes low. As a result, the reaction force during the operation of the brake pedal 3 becomes low, and the rigidity curve becomes gentler.

[0048] Furthermore, the brake feeling simulator device 1 configured as described above has the advantages of a simplified structure, less likelihood of mechanical deterioration typical of known simulator devices, being more stable, and more efficient.

[0049] According to an embodiment, the electromechanical preloading device 6 includes an electric motor 7 and a preloading mechanism 8.

[0050] The preloading mechanism 8 is configured to apply a preload to at least one elastic element 4.

[0051] The electric motor 7 is configured to operate the preloading mechanism 8 so that the preloading mechanism 8 applies a preload to at least one elastic element 4.

[0052] According to one embodiment, the preloading mechanism 8 is an irreversible mechanism.

[0053] Advantageously, with such a configuration, reverse movement of the preloading mechanism 8 in the absence of operation by the electric motor 7 is prevented.

[0054] Therefore, in the absence of operation by the electric motor 7, the preloading mechanism 8 is configured to maintain a predetermined preload on at least one elastic element 4.

[0055] Conversely, a change in the preload of at least one elastic element 4, for example, a decrease or increase in the preload, requires operation of the preloading mechanism 8 by the electric motor 7.

[0056] The brake feeling simulator device 1 configured as described above does not require the electric motor 7 to constantly operate in order to secure and maintain a predetermined preload level of at least one elastic element 4 due to the irreversibility of the preload mechanism 8, and thus can consume less energy.

[0057] Furthermore, as an advantage, the brake feeling simulator device 1 configured as described above can provide a tactile signal and feedback to the driver, such as the vibration of the brake pedal of a conventional braking system that occurs when the ABS intervenes. This is achieved by the action of the electric motor 7 configured to change the preload acting on at least one elastic element 4 by the preload mechanism 8. Such a change in preload is transmitted to the brake pedal 3 in order to obtain a desired tactile signal or vibration.

[0058] According to an embodiment, at least one elastic element 4 is disposed intervening between the thrust piston 5 and the electromechanical preloading device 6.

[0059] According to one embodiment, at least one elastic element 4 is disposed intervening between the thrust piston 5 and the preloading device 8.

[0060] According to one embodiment, at least one elastic element 4 includes a first end portion and a second end portion opposing the first end portion. The first end portion of at least one elastic element 4 is positioned to abut against the thrust piston 5, and the second end portion of at least one elastic element 4 is positioned to abut against the preload mechanism 8.

[0061] Screw nut screw assembly 10

[0062] According to an embodiment, the preload mechanism 8 is a screw nut screw assembly 10.

[0063] The screw nut screw assembly 10 faces at least one elastic element 4.

[0064] Furthermore, the screw nut screw assembly 10 is coaxial with the operating shaft 9.

[0065] The screw nut screw assembly 10 is composed of a screw 11 and a nut screw 12.

[0066] The screw 11 and the nut screw 12 are connected to each other such that the relative translation of the nut screw 12 with respect to the screw 11 along the operating shaft 9 corresponds to the relative rotation of the nut screw 12 with respect to the screw 11 about the operating shaft 9.

[0067] The electric motor 7 includes a drive shaft 13 extending along the motor shaft 14.

[0068] The screw nut screw assembly 10 is connected to the drive shaft 13.

[0069] The electric motor 7 is configured to apply mechanical torque to at least one of the screw 11 and the nut screw 12 to move at least one of the screw 11 and the nut screw 12 along the operating shaft 9 towards or away from the thrust piston 5, thereby increasing or decreasing the preload of at least one elastic element 4.

[0070] Specifically, the movement of the screw 11 or the nut screw 12 towards the thrust piston 5 corresponds to an increase in the preload of at least one elastic element 4 intervening between the screw nut screw assembly 10 and the thrust piston 5.

[0071] Conversely, when the screw 11 or the nut screw 12 moves towards the thrust piston 5, the preload of at least one elastic element 4 intervening between the screw nut screw assembly 10 and the thrust piston 5 will decrease.

[0072] According to an embodiment, the brake feeling simulator device 1 includes a housing wall 15 extending along the operating shaft 9.

[0073] The housing wall 15 defines a housing compartment 16 therein.

[0074] The screw nut screw assembly 10 is housed within the housing compartment 16.

[0075] According to an embodiment, the screw 11 of the screw nut screw assembly 10 is connected to the drive shaft 13 of the electric motor 7 such that the screw 11 receives mechanical torque from the electric motor 7.

[0076] The screw 11 is configured to rotate with respect to the housing wall 15, but not to translate with respect to the housing wall 15.

[0077] Furthermore, the nut screw 12 of the screw nut screw assembly 10 is configured to translate along the operating shaft 9 with respect to the housing wall 15, but not to rotate with respect to the housing wall 15.

[0078] Furthermore, the nut screw 12 is configured to move along the operating shaft 9 towards or away from the thrust piston 5, thereby increasing or decreasing the preload of at least one elastic element 4.

[0079] Specifically, the movement of the nut screw 12 towards the thrust piston 5 corresponds to an increase in the preload of at least one elastic element 4 interposed between the nut screw 12 and the thrust piston 5.

[0080] Conversely, the movement of the nut screw 12 away from the thrust piston 5 corresponds to a decrease in the preload of at least one elastic element 4 interposed between the nut screw 12 and the thrust piston 5.

[0081] According to this embodiment, the first end of at least one elastic element 4 abuts against the thrust piston 5, and the second end of at least one elastic element 4 abuts against the nut screw 12.

[0082] According to an alternative embodiment, the nut screw 12 of the screw nut screw assembly 10 is connected to the drive shaft 13 of the electric motor 7 such that the nut screw 12 receives mechanical torque from the electric motor 7.

[0083] The nut screw 12 is configured to rotate relative to the housing wall 15 but not to translate relative to the housing wall 15.

[0084] Furthermore, the screw 11 of the screw nut screw assembly 10 is configured to translate along the actuating shaft 9 relative to the housing wall 15 without rotating relative to the housing wall 15.

[0085] Furthermore, the screw 11 is configured to move along the actuating shaft 9 towards or away from the thrust piston 5, thereby increasing or decreasing the preload of at least one elastic element 4.

[0086] Specifically, the movement of the screw 11 in the direction towards the thrust piston 5 corresponds to an increase in the preload of at least one elastic element 4 interposed between the screw 11 and the thrust piston 5.

[0087] Conversely, the movement of the screw 11 in the direction away from the thrust piston 5 corresponds to a decrease in the preload of at least one elastic element 4 interposed between the screw 11 and the thrust piston 5.

[0088] According to this embodiment, the first end of at least one elastic element 4 abuts against the thrust piston 5, and the second end of at least one elastic element 4 abuts against the screw 11.

[0089] According to this embodiment, the screw of the screw nut screw assembly 10 is irreversible.

[0090] The preload of at least one elastic element 4, which is realized by the nut screw 12 or by the screw 11 abutting against at least one elastic element 4, is maintained even in the absence of actuation from the electric motor 7.

[0091] According to an embodiment, the screw nut screw assembly 10 and the electric motor 7 are arranged such that the operating axis 9 coincides with the motor axis 14.

[0092] According to an embodiment, the electric motor 7 is arranged on the side opposite to the thrust piston 5 with respect to the screw nut screw assembly 10.

[0093] Advantageously, such a configuration ensures the integrity and structural strength of the brake feeling simulator device 1.

[0094] According to an embodiment, the nut screw 12 is arranged opposite to the electric motor 7 with respect to the screw 11.

[0095] Advantageously, such a configuration reduces the overall distortion that the brake feeling simulator device 1 undergoes during its operation.

[0096] According to an embodiment, the brake feeling simulator device 1 comprises a transmission 17.

[0097] The transmission 17 is interposed between the electric motor 7 and the preloading mechanism 8.

[0098] For example, the transmission 17 is a planetary gear type transmission, a harmonic gear type or a cycloid speed reducer, or a cascade gear distribution.

[0099] According to one embodiment, the brake feeling simulator device 1 includes a bearing 18 interposed between the electric motor 7 and the preloading mechanism 8.

[0100] Preferably, the bearing 18 is a thrust type bearing. Preferably, the bearing 18 is a ball type or roller type bearing.

[0101] According to one embodiment, the transmission 17 is interposed between the bearing 18 and the preloading mechanism 8.

[0102] According to an embodiment, at least one elastic element 4 is disposed inside the housing compartment 16.

[0103] At least one elastic element 4 is configured to apply a reaction force in response to the operation of the brake feeling simulator device 1. Specifically, at least one elastic element 4 is configured to apply a reaction force to the thrust piston 5 that moves translationally with respect to at least one elastic element 4 in response to the operation of the brake pedal 3 by the driver. Therefore, at least one elastic element 4 is configured to apply a reaction force to the brake pedal 3 in response to the operation of the brake pedal 3 by the driver.

[0104] According to an embodiment, at least one elastic element 4 is configured to be biased along a direction substantially parallel to the operating axis 9. Preferably, at least one elastic element 4 is configured to be biased along a direction substantially coinciding with the operating axis 9.

[0105] Furthermore, at least one elastic element 4 is configured to bias the thrust piston 5 toward its rest position.

[0106] Therefore, during the operation of the brake feeling simulator device 1, the thrust piston 5 is moved from its rest position against at least one elastic element 4. When the operation of the brake feeling simulator device 1 is interrupted, at least one elastic element 4 biases the thrust piston 5 back to its rest position.

[0107] According to an embodiment, at least one elastic element 4 is constituted by at least one compression coil spring arranged substantially coaxially with the actuating shaft 9.

[0108] According to an embodiment, the first end of at least one compression coil spring is positioned to abut against the thrust piston 5, and the second end of at least one compression coil spring is positioned to abut preferably against the mechanism 8, preferably the screw nut screw assembly 10, more preferably the nut screw 12, or the screw 11, or the worm screw 28, or the gear 27.

[0109] According to an embodiment, the brake feeling simulator device 1 comprises a plurality of elastic elements 4 arranged in series and / or in parallel inside the brake feeling simulator device 1 and preferably inside the housing compartment 16.

[0110] According to an embodiment, the plurality of elastic elements 4 consists of coil springs and / or angular springs and / or screw springs and / or band springs and / or shaped springs.

[0111] According to an embodiment, the thrust device 5 forms a blind piston cavity. The blind piston cavity is open in the direction of the preloading mechanism 8.

[0112] According to an embodiment, the first end of at least one elastic element 4 is received within the blind piston cavity.

[0113] According to an embodiment, the thrust device 5 includes a bias wall 19.

[0114] The bias wall faces at least one elastic element 4.

[0115] The bias wall is substantially transverse to the working wall 9.

[0116] The thrust piston 5 is configured to receive a bias of hydraulic fluid on the bias wall 19 so as to cause the thrust piston 5 to translate toward at least one elastic element 4.

[0117] The bias wall 19 faces the conveying pipe 21.

[0118] The conveying pipe 21 is configured to fluidly connect the brake pedal 3 to the brake feeling simulator device 1 by hydraulic fluid.

[0119] Specifically, the conveying pipe 21 is configured to convey hydraulic fluid to the brake feeling simulator device 1 when the brake pedal 3 is actuated, and to discharge the hydraulic fluid from the brake feeling simulator device 1 when the brake pedal 3 is released.

[0120] Preferably, the conveying pipe 21 is at least partially defined by the housing wall 15.

[0121] According to an embodiment, the brake feeling simulator device 1 includes at least one auxiliary elastic element 22.

[0122] At least one auxiliary elastic element 22 is interposed between the thrust piston 5 and the conveying pipe 21.

[0123] At least one auxiliary elastic element 22 is arranged to abut against the thrust piston 5.

[0124] Advantageously, at least one auxiliary elastic element 22 is configured to prevent the thrust piston 5 from colliding with the conveying pipe 21 under the bias of at least one elastic element 4 in the absence of actuation by the brake pedal 3.

[0125] According to an embodiment, at least one auxiliary elastic element 22 is constituted by at least one compression coil spring arranged substantially coaxially with the actuating shaft 9.

[0126] According to this embodiment, the first end portion of at least one compression coil spring is arranged to abut against the thrust piston 5, specifically the bias wall 19, and the second end portion of at least one compression coil spring is arranged to abut against the housing wall 15 forming the conveying pipe 21.

[0127] According to an embodiment, the brake feeling simulator device 1 comprises a plurality of auxiliary elastic elements 22 arranged in series and / or in parallel inside the brake feeling simulator device 1.

[0128] According to an embodiment, the plurality of auxiliary elastic elements 22 comprise coil springs and / or angular springs and / or screw springs and / or band springs and / or shaped springs.

[0129] Furthermore, the thrust piston 5 comprises a thrust wall 20 facing the bias wall 19.

[0130] The thrust wall 20 faces at least one elastic element 4. Specifically, the first end portion of at least one elastic element 4 is positioned to abut against the thrust wall 20.

[0131] According to an embodiment, the thrust piston 5 comprises a guide rod 23 extending in a direction parallel to the actuating shaft 9.

[0132] Preferably, the guide rod 23 extends along the actuating shaft 9.

[0133] Preferably, the guide rod 23 is connected to the thrust wall 20 of the thrust piston 5.

[0134] According to this embodiment, the nut screw 12 is the guide rod 23 and forms a through hole 24. Preferably, the through hole 24 is coaxial with the operating shaft 9.

[0135] The guide rod 23 is positioned to pass through the through hole 24 of the nut screw 12.

[0136] In this way, the guide rod 23 and the nut screw 12 achieve a geometric coupling.

[0137] The guide rod 23 is configured to translate along the operating shaft 9 passing through the through hole 24 of the nut screw 12 as the thrust piston 5 translates.

[0138] Advantageously, the geometric coupling between the guide rod 23 and the nut screw 12 ensures the correct orientation of the thrust piston 5 within the brake feeling simulator device 1, and in particular with respect to the screw nut screw assembly 10, avoids misalignments and misplacements that could cause risks of damage, wear, or increased stress to the brake feeling simulator device 1.

[0139] According to the embodiment, at least one elastic element 4 is arranged substantially coaxially with the guide rod 23.

[0140] According to the embodiment, at least one auxiliary elastic element 22 is interposed between the thrust piston 5 and the guide rod 23.

[0141] According to this embodiment, at least one auxiliary elastic element 22 is configured to bias the guide rod 23 in a direction away from the thrust piston 5.

[0142] Advantageously, at least one auxiliary elastic element 22 prevents the thrust piston 5, which is deflected by the hydraulic fluid, from suddenly colliding with the guide rod 23 with the risk of damaging such components. Conversely, at least one auxiliary elastic element 22 is configured to allow movement, approach, and relative contact between the thrust piston 5 and the guide rod 23.

[0143] According to an embodiment, the brake feeling simulator device 1 comprises at least one hydraulic seal 25.

[0144] At least one hydraulic seal 25 is arranged on the preload piston 5 and is configured to prevent leakage of the hydraulic fluid towards at least one elastic element 4 and the electromechanical preloading device 6.

[0145] Specifically, at least one hydraulic seal 25 is interposed between the thrust piston 5 and the housing wall 15.

[0146] Advantageously, due to at least one hydraulic seal 25, the hydraulic fluid is confined within the brake feeling simulator device 1 in the space between the transfer tube 21 and the bias wall 19 of the thrust piston 5.

[0147] According to an embodiment, at least one hydraulic seal 25 is arranged on the preloading mechanism 8 and is configured to prevent leakage of the hydraulic fluid towards at least one elastic element 4 and the electromechanical preloading device 6.

[0148] Specifically, at least one hydraulic seal 25 is interposed between the preloading mechanism 8 and the housing wall 15.

[0149] Worm screw gear 26

[0150] According to an alternative embodiment, the preloading mechanism 8 is a worm screw gear 26.

[0151] The worm screw gear 26 faces at least one elastic element 4.

[0152] The worm screw gear 26 is composed of a gear 27 and a worm screw 28.

[0153] The worm screw 28 extends along the operating shaft 9.

[0154] The gear 27 is coaxial with an axis parallel to the operating shaft 9 or an axis transverse to the operating shaft 9, and extends substantially in a plane passing through the worm screw 28 and the operating shaft 9.

[0155] The gear 27 and the worm screw 28 are connected to each other such that the relative rotation of the worm screw 28 about the operating shaft 9 with respect to the gear 27 corresponds to the relative translation of the worm screw 28 along the operating shaft 9 with respect to the gear 27.

[0156] The electric motor 7 includes a drive shaft 13 extending along the motor shaft 14.

[0157] The worm screw gear 26 is connected to the drive shaft 13.

[0158] The electric motor 7 is configured to apply mechanical torque to at least one of the gear 27 and the worm screw 28, thereby moving at least one of the gear 27 and the worm screw 28 along an axis parallel to the operating shaft 9, either towards or away from the thrust piston 5, and increasing or decreasing the preload of at least one elastic element 4 that can increase or decrease the preload of at least one elastic element 4.

[0159] Specifically, the translation of the gear 27 or the worm screw 28 towards the thrust piston 5 corresponds to an increase in the preload of at least one elastic element 4 interposed between the worm screw gear 26 and the thrust piston 5.

[0160] Conversely, when the gear 27 or the worm screw 28 moves in a direction away from the thrust piston 5, the preload of at least one elastic element 4 interposed between the worm screw gear 26 and the thrust piston 5 will decrease.

[0161] According to an embodiment, the brake feeling simulator device 1 includes a housing wall 15 extending along the operating shaft 9.

[0162] The housing wall 15 defines a housing compartment 16 therein.

[0163] The worm screw gear 26 is housed inside the housing compartment 16.

[0164] According to an embodiment, the gear 27 of the worm screw gear 26 is connected to the drive shaft 13 of the electric motor 7, and the gear 27 is configured to receive mechanical torque from the electric motor 7.

[0165] The gear 27 is configured to rotate with respect to the housing wall 15 but not to translate with respect to the housing wall 15.

[0166] Furthermore, the worm screw 28 of the worm screw gear 26 is configured to translate along the operating shaft 9 with respect to the housing wall 15 but not to rotate with respect to the housing wall 15.

[0167] Furthermore, the worm screw 28 is configured to move along the operating shaft 9 towards or away from the thrust piston 5, thereby increasing or decreasing the preload of at least one elastic element 4.

[0168] Specifically, the movement of the worm screw 28 towards the thrust piston 5 corresponds to an increase in the preload of at least one elastic element 4 interposed between the worm screw 28 and the thrust piston 5.

[0169] Conversely, the translation of the worm screw 28 away from the thrust piston 5 corresponds to a decrease in the preload of at least one elastic element 4 interposed between the worm screw 28 and the thrust piston 5.

[0170] According to this embodiment, the first end of at least one elastic element 4 abuts against the thrust piston 5, and the second end of at least one elastic element 4 abuts against the worm screw 28.

[0171] According to an alternative embodiment, the worm screw 28 of the worm screw gear 26 is connected to the drive shaft 13 of the electric motor 7 such that the worm screw 28 receives mechanical torque from the electric motor 7.

[0172] The worm screw 28 is configured to rotate with respect to the housing wall 15 but not to translate with respect to the housing wall 15.

[0173] Furthermore, the gear 27 of the worm screw gear 26 is configured to translate along the actuating shaft 9 with respect to the housing wall 15 but not to rotate with respect to the housing wall 15.

[0174] Furthermore, the gear 27 is configured to move along the actuating shaft 9 towards or away from the thrust piston 5, thereby increasing or decreasing the preload of at least one elastic element 4.

[0175] Specifically, the movement of the gear 27 towards the thrust piston 5 corresponds to an increase in the preload of at least one elastic element 4 interposed between the gear 27 and the thrust piston 5.

[0176] Conversely, the movement of the gear 27 away from the thrust piston 5 corresponds to a decrease in the preload of at least one elastic element 4 interposed between the gear 27 and the thrust piston 5.

[0177] According to this embodiment, the first end of at least one elastic element 4 abuts against the thrust piston 5, and the second end of at least one elastic element 4 abuts against the gear 27.

[0178] According to this embodiment, the gear 27 is coaxial with an axis parallel to the operating shaft 9.

[0179] According to the embodiment, the screw of the worm gear 26 is of the irreversible type.

[0180] The preload of at least one elastic element 4, which is achieved by the worm screw 28 abutting against at least one elastic element 4 or the gear 27 abutting against at least one elastic element 4, is maintained even when there is no operation from the electric motor 7.

[0181] According to the embodiment, the worm gear 26 and the electric motor 7 are arranged such that the operating shaft 9 coincides with the motor shaft 14.

[0182] Brake system 2

[0183] Furthermore, according to another aspect of the present invention, the brake system 2 comprises the brake feeling simulator device 1 described above.

[0184] Furthermore, the brake system 2 comprises a brake pedal 3 operatively connected to the brake feeling simulator device 1.

[0185] According to one embodiment, the brake system 2 comprises an electronic processing unit electrically connected to the electromechanical preloading device 6 of the brake feeling simulator device 1.

[0186] The electronic processing unit is configured to operate the electromechanical preloading device 6 so as to obtain a predetermined preload of at least one elastic element 4.

[0187] Specifically, the electronic processing unit is configured to control the brake feeling simulator device 1 so as to obtain a stiffness curve selectable from a plurality of stiffness curves.

[0188] According to the present embodiment, each selectable stiffness curve corresponds to a predetermined overloading value of at least one elastic element 4 that can be implemented by the electromechanical preloading device 6.

[0189] According to the present embodiment, the brake system 2 includes at least one sensor.

[0190] The sensor is configured to directly or indirectly detect the mechanical torque applied by the electric motor 7.

[0191] Alternatively or additionally, the sensor is configured to directly or indirectly detect the translation or position along the operating axis 9 of the nut screw 12, the screw 11, the worm screw 28, or the gear 27.

[0192] According to an embodiment, the brake system 2 includes a selection device connected to the electronic processing unit.

[0193] 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.

[0194] According to an embodiment, each selectable stiffness curve corresponds to a predetermined value of the mechanical torque applied by the electric motor 7 or to a predetermined displacement or position along the operating axis 9 of the nut screw 12, the screw 11, the worm screw 28, or the gear 27.

[0195] According to an embodiment, the brake system 2 is configured to obtain at least two, preferably at least three, different stiffness curves.

[0196] The stiffness curves differ in their different steepnesses, and thus differ in the hardness perceptible to the driver operating the brake pedal 3.

[0197] As an example, the driver can select from three different stiffness curves, for example called "Sports", "Drive", and "City", according to their respective hardnesses.

[0198] According to an embodiment, the braking system 2 comprises a master cylinder 29 connected to the brake pedal 3.

[0199] The master cylinder 29 includes a float 30, and the float 30 is moved by the mechanical action of the driver on the brake pedal 3. The float 30 has the function of pressurizing the hydraulic fluid.

[0200] Furthermore, the hydraulic fluid is accommodated in a reservoir 31 that is fluidly connected to the master cylinder 29.

[0201] The master cylinder 29 is fluidly connected to the brake feeling simulator device 1 by a first hydraulic duct 32 that houses the hydraulic fluid.

[0202] According to an embodiment, a first on-off valve 33 is arranged along the first hydraulic duct 32. The on-off valve 33 can be opened and closed. In the open state, it enables the fluid connection between the master cylinder 29 and the brake feeling simulator device 1, and in the closed state, it cuts off the brake feeling simulator device 1 from the master cylinder 29.

[0203] According to an embodiment, the braking system 2 further comprises a second hydraulic duct 34 operatively connected to at least one braking device associated with the wheels of the vehicle.

[0204] The second hydraulic duct 34 is connected to the first hydraulic duct 32 by a second on-off valve 35.

[0205] The second on-off valve 35 can be opened and closed in sequence. In the open state, the second on-off valve 35 enables the fluid connection between the master cylinder 29 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 35 prevents the direct hydraulic connection between the master cylinder 29 and the braking device. Therefore, the second hydraulic pipeline 34 functions as a backup in case of failure of the electric actuating means or power outage.

[0206] Naturally, 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.

Explanation of reference signs

[0207] List of reference numbers 1. Brake operation feeling simulator device 2. Braking system 3. Brake pedal 4. Elastic element 5. Thrust piston 6. Electromechanical preloading device 7. Electric motor 8. Preloading mechanism 9. Actuating shaft 10. Screw nut screw assembly 11. Screw 12. Nut screw 13. Drive shaft 14. Drive shaft 15. Housing wall 16. Housing compartment 17. Transmission 18. Bearing 19. Bias wall 20. Thrust wall 21. Delivery pipe 22. Auxiliary elastic element 23. Guide rod 24. Through hole 25. Hydraulic seal 26. Worm screw gear 27. Gear 28. Worm screw 29. Master cylinder 30. Float 31. Tank 32. First hydraulic duct 33. First on-off valve 34. Second hydraulic duct 35. Second on-off valve

Claims

1. A brake feeling simulator device (1) for a brake system (2), wherein the brake feeling simulator device (1) is adapted to be connected to a brake pedal (3), the brake feeling simulator device (1) comprising: at least one elastic element (4); a thrust piston (5) configured to be biased against the at least one elastic element (4) in response to actuation of the brake pedal (3); an electromechanical preloading device (6) configured to apply a preload to the at least one elastic element (4).

2. The brake feeling simulator device (1) according to claim 1, wherein the electromechanical preloading device (6) comprises an electric motor (7) and a preloading mechanism (8), the preloading mechanism (8) being configured to apply a preload to the at least one elastic element (4), the electric motor (7) being configured to operate the preloading mechanism (8) such that the preloading mechanism (8) applies a preload to the at least one elastic element (4), the preloading mechanism (8) being an irreversible mechanism, optionally, the at least one elastic element (4) being disposed intervening between the thrust piston (5) and the electromechanical preloading device (6).

3. The brake feeling simulator device (1) according to claim 1 or 2, wherein the electromechanical preloading device (6) comprises an electric motor (7) and a preloading mechanism (8), the preloading mechanism (8) being configured to apply a preload to the at least one elastic element (4), the electric motor (7) being configured to operate the preloading mechanism (8) such that the preloading mechanism (8) applies a preload to the at least one elastic element (4), the preloading mechanism (8) being a screw nut screw assembly (10), the screw nut screw assembly (10) facing the at least one elastic element (4) and being coaxial with an operating axis (9), the screw nut screw assembly (10) comprising a screw (11) and a nut screw (12). The screw (11) and the nut screw (12) are connected to each other, and the relative movement of the nut screw (12) with respect to the screw (11) along the operating shaft (9) corresponds to the relative rotation of the nut screw (12) with respect to the screw (11) about the operating shaft (9). The electric motor (7) has a drive shaft (13) extending along a drive axis (14). The screw nut screw assembly (10) is connected to the drive shaft (13). The electric motor (7) is configured to apply mechanical torque to at least one of the screw (11) or the nut screw (12) so as to move at least one of the screw (11) or the nut screw (12) along the operating shaft (9) towards or away from the thrust piston (5), thereby increasing or decreasing the preload of the at least one elastic element (4). A brake feeling simulator device (1).

4. The brake feeling simulator device (1) according to claim 3, Comprising a housing wall (15) extending along the operating shaft (9). The housing wall (15) defines a housing compartment (16) within the housing wall (15). The screw nut screw assembly (10) is housed within the housing compartment (16). The screw (11) of the screw nut screw assembly (10) is connected to the drive shaft (13) of the electric motor (7) such that the screw (11) is configured to receive mechanical torque from the electric motor (7). The screw (11) is configured to rotate with respect to the housing wall (15) but not to translate with respect to the housing wall (15). The nut screw (12) of the screw nut screw assembly (10) is configured to translate along the operating shaft (9) with respect to the housing wall (15) but not to rotate with respect to the housing wall (15). The nut screw (12) is configured to move along the actuating shaft (9) towards or away from the thrust piston (5) so as to increase or decrease the preload of the at least one elastic element (4), in a brake feeling simulator device (1).

5. The brake feeling simulator device (1) according to claim 3, comprising a housing wall (15) extending along the actuating shaft (9), wherein the housing wall (15) defines a housing compartment (16) within the housing wall (15), wherein the screw nut screw assembly (10) is accommodated within the housing compartment (16), wherein the nut screw (12) of the screw nut screw assembly (10) is connected to the drive shaft (13) of the electric motor (7) such that the nut screw (12) is configured to receive mechanical torque from the electric motor (7), wherein the nut screw (12) is configured to rotate relative to the housing wall (15) but not to translate relative to the housing wall (15), wherein the screw (11) of the screw nut screw assembly (10) is configured not to translate relative to the housing wall (15) but to translate along the actuating shaft (9) relative to the housing wall (15), wherein the screw (11) is configured to move along the actuating shaft (9) towards or away from the thrust piston (5) so as to increase or decrease the preload of the at least one elastic element (4), in a brake feeling simulator device (1).

6. The brake feeling simulator device (1) according to claim 3, wherein the thread groove of the screw nut screw assembly (10) is of the irreversible type, in a brake feeling simulator device (1).

7. The brake feeling simulator device (1) according to claim 3, wherein the screw nut screw assembly (10) and the electric motor (7) are arranged such that the actuating shaft (9) coincides with the drive shaft (14), and / or, The electric motor (7) is arranged on the side opposite to the thrust piston (5) with respect to the screw nut screw assembly (10). and / or The nut screw (12) is arranged on the side opposite to the electric motor (7) with respect to the screw (11). and / or The brake feeling simulator device (1) includes a transmission (17) interposed between the electric motor (7) and the preloading mechanism (8). and / or, The brake feeling simulator device (1) includes a bearing (18) interposed between the electric motor (7) and the preloading mechanism (8). and / or, The transmission (17) is interposed between the bearing (18) and the preloading mechanism (8) in the brake feeling simulator device (1).

8. The brake feeling simulator device (1) according to any one of Claims 1 to 7, comprising a housing wall (15) extending along the operating shaft (9), The housing wall (15) defines a housing compartment (16) within the housing wall (15), The at least one elastic element (4) is arranged inside the housing compartment (16), The at least one elastic element (4) is configured to be biased along a direction substantially parallel to the operating shaft (9) so as to bias the thrust piston (5) towards the rest position of the thrust piston (5). The at least one elastic element (4) comprises at least one compression coil spring arranged substantially coaxially with the operating shaft (9), a first end of the at least one compression coil spring being arranged in contact with the thrust piston (5), and a second end of the at least one compression coil spring being arranged in contact with the electromechanical preloading device (6). or, The brake feeling simulator device (1) comprises a plurality of elastic elements (4) arranged in series and / or in parallel within the housing compartment (16), the plurality of elastic elements (4) comprising coil springs and / or square springs and / or screw springs and / or strip springs and / or shaped springs. and / or, A brake feeling simulator device (1), wherein the at least one elastic element (4) is configured to bias the thrust piston (5) towards the rest position of the thrust piston (5).

9. A brake feeling simulator device (1) according to any one of claims 1 to 8, wherein: (A) the thrust piston (5) forms a piston blind cavity opening in the direction of the preloading mechanism (8), and a first end of the at least one elastic element (4) is received within the piston blind cavity; or wherein: (B) the thrust piston (5) has a bias wall (19) facing the opposite side of the at least one elastic element (4) and substantially orthogonal to the actuating shaft (9), the thrust piston (5) is configured to receive a bias of hydraulic fluid adapted to translate the thrust piston (5) towards the at least one elastic element (4) on the bias wall (19), the bias wall (19) faces a conveyance pipe (21) configured to fluidly connect the brake feeling simulator device (1) to the brake pedal (3) by hydraulic fluid, the brake feeling simulator device (1) includes at least one auxiliary elastic element (22) interposed between the thrust piston (5) and the conveyance pipe (21), the at least one auxiliary elastic element (22) is arranged in contact with the thrust piston (5) and is configured to prevent the thrust piston (5) from colliding with the conveyance pipe (21) under the bias of the at least one elastic element (4) when the brake pedal (3) is not actuated.

10. A brake feeling simulator device (1) according to claim 4, wherein the thrust piston (5) has a guide rod (23) extending along the actuating shaft (9), the nut screw (12) forms a through hole (24) in the guide rod (23), the through hole (24) is coaxial with the actuating shaft (9). The guide rod (23) is positioned so as to pass through the through hole (24) of the nut screw (12), whereby a geometric coupling is achieved between the guide rod (23) and the nut screw (12), when the thrust piston (5) moves, the guide rod (23) moves along the operating shaft (9) through the through hole (24) of the nut screw (12), the brake feeling simulator device (1) selectively includes at least one auxiliary elastic element (22) interposed between the thrust piston (5) and the guide rod (23), the at least one auxiliary elastic element (22) is configured to bias the guide rod (23) in a direction away from the thrust piston (5), the brake feeling simulator device (1).

11. A brake feeling simulator device (1) according to any one of claims 1 to 10, the brake feeling simulator device (1) includes at least one hydraulic seal (25) disposed on the thrust piston (5) and configured to prevent leakage of hydraulic fluid toward the at least one elastic element (4) and the electromechanical preloading device (6), preferably, the brake feeling simulator device (1) includes a housing wall (15) extending along the operating shaft (9), the housing wall (15) defines a housing compartment (16) in the housing wall (15), the at least one hydraulic seal (25) is interposed between the thrust piston (5) and the housing wall (15), the brake feeling simulator device (1).

12. A brake feeling simulator device (1) according to claim 1 or 2, the electromechanical preloading device (6) includes an electric motor (7) and a preloading mechanism (8), the preloading mechanism (8) is configured to apply a preload to the at least one elastic element (4), the electric motor (7) is configured to operate the preloading mechanism (8) so that the preloading mechanism (8) applies a preload to the at least one elastic element (4), the preloading mechanism (8) is a worm screw gear (26) facing the at least one elastic element (4), The worm screw gear (26) includes a gear (27) and a worm screw (28), the worm screw (28) extends along the operating shaft (9), the gear (27) is coaxial with an axis parallel to the operating shaft (9) or coaxial with an axis perpendicular to the operating shaft (9), and extends substantially in a plane passing through the worm screw (28) and the operating shaft (9), the gear (27) and the worm screw (28) are connected to each other, and a relative rotation of the worm screw (28) about the operating shaft (9) with respect to the gear (27) corresponds to a relative translation of the worm screw (28) along the operating shaft (9) with respect to the gear (27), the electric motor (7) includes a drive shaft (13) extending along a motor shaft (14), the worm screw gear (26) is connected to the drive shaft (13), the electric motor (7) is configured to apply mechanical torque to at least one of the gear (27) and the worm screw (28), a brake feeling simulator device (1) that moves at least one of the at least gear (27) or the worm screw (28) along an axis parallel to the operating shaft (9) toward or away from the thrust piston (5) to increase or decrease the preload of at least one elastic element (4).

13. The brake feeling simulator device (1) according to claim 12, comprising a housing wall (15) extending along the operating shaft (9), the housing wall (15) defines a housing compartment (16) within the housing wall (15), the worm screw (26) is housed within the housing compartment (16), the gear (27) of the worm screw gear (26) is connected to the drive shaft (13) of the electric motor (7) such that the gear (27) receives mechanical torque from the electric motor (7), the gear (27) is configured to rotate with respect to the housing wall (15) but not to translate with respect to the housing wall (15), The worm screw (28) of the worm screw gear (26) is configured to translate along the operating shaft (9) with respect to the housing wall (15), but is configured not to rotate with respect to the housing wall (15). The worm screw (28) is configured to move along the operating shaft (9) towards the thrust piston (5) or away from the thrust piston (5), and is a brake feeling simulator device (1) that increases or decreases the preload of the at least one elastic element (4).

14. The brake feeling simulator device (1) according to claim 12, comprising a housing wall (15) extending along the operating shaft (9), the housing wall (15) defining a housing compartment (16) within the housing wall (15), the worm screw (26) being housed within the housing compartment (16), the worm screw (28) of the worm screw gear (26) being connected to the drive shaft (13) of the electric motor (7) such that the worm screw (28) is configured to receive mechanical torque from the electric motor (7), the worm screw (28) being configured to rotate with respect to the housing wall (15), but is configured not to translate with respect to the housing wall (15), the gear (27) of the worm screw gear (26) is configured to translate along the operating shaft (9) with respect to the housing wall (15), but is configured not to rotate with respect to the housing wall (15), the gear (27) moves along the operating shaft (9) towards the thrust piston (5) or away from the thrust piston (5), and is configured to increase or decrease the preload of the at least one elastic element (4), a brake feeling simulator device (1).

15. The brake feeling simulator device (1) according to claim 12, wherein the worm screw gear (26) is of an irreversible type, a brake feeling simulator device (1).

16. A braking system (2) comprising a brake feeling simulator device (1) according to any one of claims 1 to 15, and a brake pedal (3) operatively connected to the brake feeling simulator device (1).

17. The braking system (2) according to claim 16, further comprising an electronic processing unit electrically connected to the electromechanical preloading device (6) of the brake feeling simulator device (1), wherein the electronic processing unit is configured to operate the electromechanical preloading device (6) to apply a predetermined preload to the at least one elastic element (4), wherein the braking system (2) comprises at least one sensor configured to directly or indirectly detect the mechanical torque applied by the electric motor (7) and / or the movement or position of the nut screw (12) or the screw (11) or the worm screw (28) or the gear (27) along the actuating shaft (9).

18. The braking system (2) according to claim 17, comprising a selection device connected to the electronic processing unit in good faith, wherein the selection device is configured such that a driver can select a stiffness curve from a plurality of predetermined stiffness curves achievable by the brake feeling simulator device (1), wherein each of the selectable stiffness curves corresponds to a predetermined mechanical torque value applied by the electric motor (7) or to a predetermined displacement or position of the nut screw (12) or the screw (11) or the worm screw (28) or the gear (27) along the actuating shaft (9).

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