ABS device for hydraulic braking systems of bicycles, motorcycles, or light vehicles

Abstract

We provide an ABS device that is simple, lightweight, and low-cost, ensuring the complete operation of the braking system. [Solution] The ABS device for a two-wheeled bicycle comprises an electrically operated valve unit that can switch between a first operating state in which a master cylinder associated with the brake lever communicates with the actuator cylinder of the brake device, and a second operating state in which communication is interrupted and the actuator cylinder communicates with a fluid accumulator, and an electronic controller is configured to control the position of a movable member of the fluid accumulator to cause a gradual rather than abrupt fluctuation of pressure in the conduit connected to the actuator cylinder of the brake device as a function of the wheel rotation speed, or as a function of a second parameter which is the pressure in the actuator cylinder or the deceleration of the vehicle detected or calculated based on a sensor.

Description

Technical Field

[0001] The present invention relates to an ABS device for a hydraulic brake system of a bicycle or a motorcycle, for example, for an electric bicycle or a lightweight two- or three-wheeled electric vehicle, comprising: · an inlet port hydraulically connected to a master cylinder associated with a brake lever, · an outlet port hydraulically connected to an actuator cylinder associated with a brake device, · a fluid accumulator having a pressure accumulator chamber defined by a movable member within a cavity, the movable member normally being in a starting position corresponding to the minimum volume of the pressure accumulator chamber, · an electrically actuated valve unit, wherein · the inlet port and the outlet port communicate with each other, and a first operating state in which the pressure accumulator chamber of the fluid accumulator is disconnected, and · a second operating state in which the communication between the inlet port and the outlet port is blocked and the pressure accumulator chamber of the fluid accumulator communicates with the outlet port an electrically actuated valve unit that is switchable between them, and · an electronic controller configured to detect a state in which activation of the ABS function is required, and in which state, to cause switching of the valve unit from the first operating state to the second operating state, and to move the movable member of the fluid accumulator in a direction corresponding to an increase in the volume of the pressure accumulator chamber in order to cause a decrease in the pressure in the connection line between the outlet port and the actuator cylinder of the brake device. It relates to an ABS device of the type comprising.

Background Art

[0002] An ABS device of the type shown above is described and illustrated, for example, in document EP 3 789 256 B1.

[0003] Generally speaking, ABS devices specifically designed for hydraulic brake systems, particularly for two-wheeled bicycles, and especially for pedal-assist two-wheeled bicycles, have been under development for some time. The solutions proposed in the past are basically of two different types.

[0004] The first type of solution provides a first hydraulic conduit for connecting a master cylinder associated with a brake lever and an actuator cylinder associated with a brake device (typically a disc brake caliper), and a second hydraulic conduit for connecting the actuator cylinder of the brake device to a pressure accumulator chamber of a passive type fluid accumulator having a movable member that is movable against the action of a spring due to pressurized fluid entering the accumulator. An electrically operated valve, normally open, is interposed in the first hydraulic conduit to allow fluid flow from the master cylinder associated with the brake lever to the actuator cylinder associated with the brake device during normal braking. The second hydraulic conduit also includes an electrically operated valve, normally closed, to disconnect the fluid accumulator from the actuator cylinder of the brake device.

[0005] The need to activate the ABS function is typically detected using a sensor configured to detect a decrease in the rotational speed of the wheel to which the brake device is associated (typically the front wheel of a two-wheeled bicycle), indicating the initial locking of the wheel itself. Alternatively, the need to activate the ABS function can be detected by verifying when the rear wheel of a two-wheeled bicycle is likely to lift off the ground by monitoring the load acting on the axle of the rear wheel of a two-wheeled bicycle. A further method for detecting the need for intervention by the ABS function consists of directly monitoring the pressure applied to the actuator cylinder of the brake device.

[0006] When the ABS function must be activated, in this first type of known solution, the electronic controller causes an electrically operated valve interposed in a first hydraulic line to close in order to disconnect the master cylinder associated with the brake lever from the actuator cylinder associated with the brake device, and simultaneously causes an electrically operated valve interposed in a second hydraulic line to open in order to allow the flow of fluid from the actuator cylinder of the brake device to the accumulator chamber of the fluid accumulator.

[0007] An example of this first type of ABS device is described and illustrated in reference DE 19508915 A1. Further examples of this type of ABS device are described in reference DE 101 58 382 A1, EP 2 943 395 B1, WO 2017 / 115171 A2, WO 2019 / 159029 A1, EP 3 753 835 B1, and EP 3 789 256 B1.

[0008] Further reference to the prior art, a second type of solution provides a single hydraulic conduit for connecting a master cylinder associated with a brake lever and an actuator cylinder associated with a brake device, and an ABS device substantially comprising an active type fluid accumulator interposed within the hydraulic conduit, the bidirectional movement of a movable member of the accumulator being reliably controlled by an electric motor. The accumulator chamber of the device is permanently in communication with the downstream section of the hydraulic conduit connected to the actuator cylinder of the brake device. Simultaneously, the accumulator chamber of the device is also connected to the upstream section of the hydraulic conduit communicating with the master cylinder associated with the brake lever, and interposed is a one-way valve with a shutter that is elastically returned to a closed position to allow fluid flow only in the direction from the downstream section of the hydraulic conduit to the upstream section. The movable member of the fluid accumulator is configured to engage the shutter of the one-way valve and maintain it in an open position when the movable member of the device is in its starting position.

[0009] In this second type of device, during normal braking, fluid flows from the master cylinder associated with the brake lever to the actuator cylinder associated with the brake device, passing through the device's pressure accumulator chamber, because the one-way valve in its starting position remains open by the device's movable member. When the need to activate the ABS function is detected (in one of the methods described above), an electric motor controlling the movable member commands the movable member to move away from its starting position in order to cause the one-way valve to close and the volume of the pressure accumulator chamber to increase, which results in a decrease in the pressure in the brake device's actuator cylinder, leading to a resulting decrease or cessation of braking.

[0010] An example of this second type of solution is described in document EP 3 789 256 B1. Further examples of this type of solution are described in documents EP 2 985 198 B1, US 4 275 934 A, and US 2020 / 324752 A1. The same applicant has developed this type of solution, which is described in documents EP 4 132 841 B1 and EP 4 132 821 B1.

[0011] All of the aforementioned conventional solutions are effective in avoiding the risk of the wheel locking up after losing contact between the wheel and the ground during braking. However, there is a need for further improvements in this area from various perspectives.

[0012] The primary need is to produce an ABS device that is as simple, lightweight, and low-cost as possible in terms of structure.

[0013] A more important need is to ensure the reliable operation of the device under all operating conditions, to always guarantee safety to the user even if the ABS device fails, and to particularly ensure the full operation of the braking system even if the ABS device fails, or the vehicle's power supply battery is depleted, or more generally, if power to the ABS device is lost for any reason.

[0014] Another important need is to reduce the energy required to activate the ABS device as much as possible.

[0015] The type of ABS device shown at the beginning of this specification is described and illustrated in the reference EP 3 789 256 B1 already cited above. In the above prior art solution, an electric actuator in the form of a solenoid is associated with a fluid accumulator, but this has the sole function of pushing a movable member of the fluid accumulator toward its starting position to cause the fluid to flow out of the fluid accumulator when the ABS function is no longer needed, and there is no need to provide a spring to return the movable member toward its starting position. However, the above prior art solution is complex and expensive and does not allow for precise control of the pressure in the downstream pipeline connected to the actuator cylinder of the brake device on which the ABS effect depends.

[0016] With consideration for addressing the aforementioned shortcomings, the applicant has already proposed several solutions, which are the subject matter of Italian patent applications IT 10 2023 0000 14 319 and IT 10 2023 000027030, both of which are still confidential as of the filing date of this application. However, there is a need for further improvement in this field.

[0017] Furthermore, an ABS device with the preamble of claim 1 is known from the document US 2023 / 234544 A1. The above document (see in particular paragraphs 0063 and 0064) illustrates a solution in which the pressure reduction during ABS activation is instantaneous, and the pressure restoration is also substantially instantaneous, as it is performed using a spring after the current supply to the solenoid is cut off without any modulation.

[0018] Another solution is known from reference JP 2006 069303 A.

[0019] Object of the invention The main objective of the present invention is to effectively solve all the problems of the prior art mentioned above.

[0020] In particular, the first objective of the present invention is to provide an ABS device that is efficient in operation, simple in structure, and low in cost.

[0021] A further objective of the present invention is to provide an ABS device that guarantees complete safety to the user in all operating conditions and ensures the correct operation of the braking system even when the ABS device is malfunctioning, i.e., even without power supply.

[0022] A further object of the present invention is to provide an ABS device that has minimal energy consumption to activate the ABS function. [Overview of the project]

[0023] With consideration to achieving one or more of the aforementioned objectives, the present invention provides an ABS device having all the characteristics described at the beginning of this specification. · The electronic controller is configured to control the position of the movable member of the fluid accumulator both during activation of the ABS function and during deactivation of the ABS function, in order to cause a gradual and not abrupt variation of the pressure in the connection pipe to the actuator cylinder of the brake device. · The gradual pressure variation is: · As a function of a first parameter which is the rotational speed of the wheel associated with the brake device, detected or calculated based on a signal emitted by a sensor intended to be associated with the wheel, and similarly: · A second parameter which is: the pressure in the actuator cylinder (3) of the brake device, or the deceleration of the vehicle detected or calculated based on a sensor intended to be associated with the vehicle and which is a second parameter as a function of determined by the electronic controller and further characterized in that it concerns an ABS device.

[0024] In a preferred form of the embodiment, the ABS device is · The switching of the valve unit between the first operating state and the second operating state is a solenoid, operably associated with the movable member of the fluid accumulator, and when the solenoid is energized, it: · Causes the switching of the valve unit from the first operating state to the second operating state, · And the application of a force to the movable member of the fluid accumulator tending to push it towards its starting position corresponding to the minimum volume of the accumulator chamber and is controlled by a solenoid configured and arranged to cause both, and When the electronic controller determines that the state requiring activation of the ABS function is met, the electronic controller performs the following actions: In the first phase, a relatively high level of current is supplied to the solenoid in order to switch the valve unit from the first operating state to the second operating state, pushing the movable member of the fluid accumulator to its starting position. In the subsequent second phase, the valve unit remains in its second operating state, while the current intensity of the current supplied to the solenoid is gradually reduced so that the movable member of the fluid accumulator moves away from its starting position to cause a gradual decrease in the pressure in the connecting pipeline between the outlet and the actuator cylinder of the brake device. In the subsequent third phase, the movable member of the fluid accumulator returns to its starting position, determining a gradual increase in the pressure in the connecting pipeline between the outlet and the actuator cylinder of the brake device, while gradually increasing the current intensity of the current supplied to the solenoid so that the valve unit remains in its second operating state. In the subsequent fourth phase, after the movable member of the fluid accumulator has returned to its starting position and the ABS functionality is no longer required, the electronic controller cuts off the supply of current to the solenoid, thereby returning the valve unit to its first operating state, while the movable member of the fluid accumulator remains in its starting position. It is programmed to execute This is a further characteristic.

[0025] In the second phase mentioned above, the current flowing through the solenoid is reduced in proportion to the force generated by the fluid acting on the moving member of the fluid accumulator, in order to ensure safe braking by allowing the movable member to move and, consequently, gradually reducing the pressure on the caliper. Similarly, when the ABS function is no longer needed, the pressure on the caliper is gradually restored.

[0026] In one example, the valve unit is: • Main passage connecting the inlet to the outlet, - A first valve interposed in the main passage between the inlet and outlet, which is in the open position in the first operating state of the valve unit, - Controls the connection between the main passage and the pressure accumulation chamber of the fluid accumulator, and the second valve which is in the closed position in the first operating state of the valve unit, • An actuator member that is movable against the action of a spring due to the energization of the solenoid, so as to move the first valve to the closed position and the second valve to the open position simultaneously. - If power to the solenoid is unavailable, the spring associated with the actuator member is configured to return the actuator member to a position in which it keeps the first valve open and the second valve closed, even in the presence of an increase in pressure in the main passage determined by the braking force. It has.

[0027] Furthermore, the present invention relates to a control method implemented using the ABS device defined above. [Brief explanation of the drawing]

[0028] Further characteristics and advantages of the present invention will be derived from the following description with reference to the accompanying drawings, which are provided only as non-limiting examples: [Figure 1] This is a schematic side view of a two-wheeled bicycle having an electric assist motor using an ABS device according to the present invention. [Figure 2] These are schematic diagrams of a hydraulic brake system including an ABS device according to the present invention in a first operating state and a second operating state, respectively. [Figure 3]These are schematic diagrams of a hydraulic brake system including an ABS device according to the present invention in a first operating state and a second operating state, respectively. [Figure 4] This is a cross-sectional view of an example of an embodiment of the ABS device according to the present invention in four different operating states. [Figure 5] This is a cross-sectional view of an example of an embodiment of the ABS device according to the present invention in four different operating states. [Figure 6] This is a cross-sectional view of an example of an embodiment of the ABS device according to the present invention in four different operating states. [Figure 7] This is a cross-sectional view of an example of an embodiment of the ABS device according to the present invention in four different operating states. [Figure 4A] This is a detailed view of Figure 4 at a magnified scale. [Figure 5A] This is a detailed view of Figure 5 at a magnified scale. [Figure 6A] This is a view of Figure 6 in detail, shown at a magnified scale. [Figure 7A] This is a detailed view of Figure 7 at a magnified scale. [Figure 8] Figures 4 to 7 are perspective views of the ABS device. [Figure 9] This is a block diagram showing a method for controlling the current supplied to a solenoid in an ABS device according to the present invention. [Figure 10] This diagram shows the fluctuations in signals indicating vehicle speed, front wheel rotation speed, factors indicating front wheel slip relative to the ground, pressure in the master cylinder, and pressure in the brake device actuator cylinder before and during ABS function activation. [Modes for carrying out the invention]

[0029] Figure 1 is a schematic diagram of a two-wheeled bicycle B having a frame T that rotatably supports a crank unit P, which is connected by a chain transmission CH to the hub of a rear wheel R2, which is rotatably supported by the frame T. An electric motor M is associated with the hub of the rear wheel R2 to assist the driver's action on the pedals. The frame T includes a steering tube that rotatably supports a steering stem having an upper end connected to a handlebar H and a lower end connected to the front fork of the two-wheeled bicycle, which rotatably supports a front wheel R1. A disc brake device F includes a disc D associated with wheel R1 and rotatably connected to the hub of the front wheel R1, and a hydraulically operated brake caliper C supported by one of the two arms of the front fork of the two-wheeled bicycle. Figure 1 does not show a brake device associated with the rear wheel R2, which may be, for example, a hydraulically operated disc brake device.

[0030] Brake device F associated with the front wheel is controlled by a hydraulic brake system, which includes an ABS device 1, which is described in detail below with reference to Figures 2 and 3, and is similarly described in detail below herein.

[0031] Figure 1 shows an example in which the ABS device 1 is supported by one of the two arms of the front fork of a two-wheeled bicycle, adjacent to the disc brake device F associated with the front wheel R1. However, the placement of the ABS device on a two-wheeled bicycle may vary. For example, the ABS device may be mounted inside one of the tubes that are part of the frame T, as taught by document DE 10 2019 118 949 A1, co-owned by the applicant, or it may be mounted inside the steering stem, as taught by document IT102023000027039 (not yet publicly disclosed as of the date of the invention).

[0032] Referring to Figures 2 and 3, reference numeral 1 denotes a hydraulic brake system for a two-wheeled bicycle as a whole, including an ABS device schematically shown as a whole, which comprises a master cylinder 2 associated with a brake lever (not shown) of the two-wheeled bicycle in any known manner, and actuator cylinders 3 and 4 associated with a brake device F in any known manner.

[0033] The ABS device 4 includes an inlet 5 that is hydraulically connected to the master cylinder 2 of the brake lever via a hydraulic pipeline 6, and an outlet 7 that is hydraulically connected to the actuator cylinder 3 of the brake caliper via a hydraulic pipeline 8.

[0034] The ABS device 4 comprises a fluid accumulator 9 having a pressure accumulation chamber 10 defined by a movable member 11, which is a piston provided with a rod 12 in this example. The piston 11 is movable within the cavity of the body of the fluid accumulator 9 and is normally in a starting position (shown in Figure 2) corresponding to the minimum volume of the pressure accumulation chamber 10.

[0035] The ABS device 4 further comprises a valve unit, which is shown as a whole in 13, is electrically operated, and is switchable between a first operating state and a second operating state.

[0036] In the first operating state of the valve unit 13 shown in Figure 2, the valve unit 13 connects the inlet 5 and the outlet 7 to each other, thereby allowing the brake system to operate normally and enabling the user to activate the brake caliper C (Figure 1) by acting on the brake lever. The valve unit 13 is normally maintained in the first operating state shown in Figure 2 by the elastic means 14.

[0037] The valve unit 13 can be switched from a first operating state shown in Figure 2 to a second operating state shown in Figure 3 via the energization of the solenoid 15 (described in more detail below), where communication between the inlet 5 and the outlet 7 is interrupted, and the accumulator chamber 10 of the fluid accumulator 9 communicates with the outlet 7.

[0038] The power supply to the solenoid 15 is controlled by the electronic controller E of the ABS device. The electronic controller E is configured to detect a condition requiring activation of the ABS function by receiving a signal S indicating such a need, which comes from any known type of sensor SE (see Figure 1) provided on the motorcycle and suitable for detecting or calculating the angular rotation speed of the front wheel R1 of the motorcycle. In the example in Figure 1, the sensor SE is supported adjacent to the brake disc D of the front wheel R1.

[0039] The main feature of the present invention is that, both during activation and deactivation of the ABS function, the electronic controller E is configured to control the position of the movable member 11 of the fluid accumulator 9 so as to cause a gradual rather than abrupt change in the pressure in the connecting pipeline to the actuator cylinder 3 of the brake device.

[0040] The progressive pressure fluctuation is determined by the electronic controller as a function of two parameters. The first parameter is the rotational speed of the wheel R1 to which the brake device is associated, which is detected or calculated based on a signal S emitted by a sensor SE. The second parameter is either the force applied to the brake device's operating lever (or a related parameter, e.g., pressure in the master cylinder 2), or the deceleration of the vehicle, which is detected or calculated based on a sensor intended to be associated with the vehicle (e.g., an accelerometer or an inertial platform).

[0041] The aforementioned characteristics are also applicable to ABS devices configured differently from those shown in Figures 2 and 3, for example, to ABS devices having a first solenoid valve for controlling communication between the master cylinder 2 and actuator cylinder 3 of the brake device, and a second solenoid valve for controlling communication between the chamber 10 of the fluid accumulator 9 and the conduit 8 connected to the actuator cylinder (3).

[0042] However, the implementation schematically shown in Figures 2 and 3 constitutes a preferred form of the embodiment of the present invention.

[0043] Referring again to Figures 2 and 3, when the electronic controller E determines that it is necessary to activate the ABS function based on the signal S indicating the angular velocity of the front wheel R1, the electronic controller E supplies current to the solenoid 15 in a manner that will be described in more detail below, in order to switch the valve unit 13 from its first operating state shown in Figure 2 to its second operating state shown in Figure 3.

[0044] In a preferred embodiment of the present invention, the solenoid 15 that controls the switching of the valve unit 13 is operably associated with a movable member 11 of the fluid accumulator 9 and is configured and arranged such that, when activated, it tends to apply a force F1 to the movable member 11 of the fluid accumulator 9 that attempts to maintain the movable member 11 in its starting position corresponding to the minimum volume of the accumulator chamber 10.

[0045] Therefore, the solenoid 15 can simultaneously control both the switching of the valve unit 13 (in a manner that will be described in detail below) and the pressure applied to the movable member 11 of the fluid accumulator 9, which attempts to push the movable member 11 toward its starting position corresponding to the minimum volume of the accumulator chamber 10.

[0046] In a preferred embodiment of the design, the solenoid 15 is mounted coaxially around the fluid accumulator 9 in a position where it is also suitable to cooperate with an actuator member (described in detail below) that controls the operating state of the valve unit 13, as will be apparent below.

[0047] The pressure sensor P1 is suitable for detecting the pressure inside the actuator cylinder 3 of the brake caliper and for sending a signal indicating the detected pressure to the electronic controller E.

[0048] The operation of the ABS device, as illustrated in Figures 2 and 3, is as follows:

[0049] During normal use of the two-wheeled bicycle, when the ABS function is not needed, the solenoid 15 is not supplied with current, and the valve unit 13 is in its first operating state as shown in Figure 2. In this state, the action on the brake lever causes fluid to be transferred from the master cylinder 2 through conduit 6, valve unit 13, and conduit 8 to the actuator cylinder 3 of the brake caliper, and the actuator cylinder 3 is thus activated as usual.

[0050] The spring 14 is configured to be able to counteract the hydraulic pressure generated by the pressure applied to the brake lever side, even when the user applies maximum force.

[0051] If the electronic controller E determines the need for ABS function intervention based on a signal S indicating the rotational speed of the front wheel R1, in the first phase, the electronic controller E supplies a relatively high level of current to the solenoid 15 to switch the valve unit 13 from a first operating state to a second operating state, but pushes the movable member 11 of the fluid accumulator 9 to its starting position as shown in Figure 2, even though the accumulator chamber 9 receives pressurized fluid from the conduit 8 connected to the actuator cylinder 3 of the brake caliper.

[0052] In the subsequent second phase, the electronic controller progressively reduces the current intensity supplied to the solenoid 15 so that the valve unit 13 remains in its second operating state as illustrated in Figure 3, while the movable member 11 of the fluid accumulator 9 moves away from its starting position (as shown in Figure 3) because the force due to the pressure of the fluid reaching the chamber 10 exceeds the force applied to the movable member 11 by the solenoid 15. The increase in the volume of the chamber 10 causes a progressive decrease in the pressure in the conduit 8 connected to the actuator cylinder 3 of the brake caliper, resulting in an ABS effect, which prevents wheel lock-up during braking.

[0053] In this phase, the gradual decrease in pressure within the conduit 8 is controlled by the controller E as a function of the signal S indicating the angular velocity of the front wheel R1, and based on the feedback signal from the sensor P1 that detects the pressure within the conduit 8.

[0054] In the above state, if for any reason the pressure in the downstream conduit 8 tends to exceed the pressure in the upstream conduit 6, the one-way valve 13A, which forms part of the valve unit 13, automatically opens, connecting the downstream conduit 8, which is connected to the actuator cylinder 3 of the brake caliper, to the upstream conduit 6, which is connected to the master cylinder 2 of the lever.

[0055] As shown, in the phase of activating the ABS function, the electronic controller E controls the current supplied to the solenoid 15 in order to establish a specific pressure level in the actuator cylinder of the brake caliper, solely as a function of the rotational speed of the wheel R1 and solely based on the feedback signal provided by the pressure sensor P1, and therefore without the need to provide a sensor regarding the position of the movable member of the fluid accumulator.

[0056] In the subsequent third phase, the electronic controller E progressively increases the current intensity supplied to the solenoid 15 so that the movable member 11 of the fluid accumulator 9 returns to its starting position (as shown in Figure 2) due to the increase in the force F1 applied by the solenoid 15, while the valve unit 13 remains in its second operating state as shown in Figure 3.

[0057] In this phase, the controller E controls the current supplied to the solenoid 15 only as a function of the rotational speed of the wheel R1 and based only on the feedback signal provided by the pressure sensor P1, in order to establish a specific pressure level within the actuator cylinder of the brake caliper.

[0058] In the subsequent fourth phase, after the movable member 11 of the fluid accumulator 9 returns to its starting position and the ABS functionality is no longer required, the electronic controller E cuts off the supply of current to the solenoid 15, thereby returning the valve unit to its first operating state as shown in Figure 2, while the movable member of the fluid accumulator 9 remains in its starting position as shown in Figure 2.

[0059] Referring now to Figures 4 to 8, with respect to specific examples of embodiments of the present invention, the parts shown in Figures 2 and 3 that functionally correspond to the parts shown in these figures are indicated by the same reference numerals.

[0060] In this example, the solenoid 15 is housed between an inner tubular sleeve 150 and an outer cylindrical housing 151. Inside the cylindrical sleeve 151 is a stator body 152 traversed by a central cylindrical cavity 152A, within which the rod 12 of the piston constituting the movable member 11 of the fluid accumulator 9 is slidably mounted. Inside the tubular sleeve 150 is a movable armature 153 in the shape of a cylindrical body, which is held in place by a vibration-damping spring 154 pressed against the end of the rod 12 opposite the piston 11.

[0061] The main body 16 of the valve unit 13 defines an inlet 5 that can be connected hydraulically to the master cylinder of the brake lever, an outlet 7 that is connected hydraulically to the actuator cylinder of the brake caliper, and a main passage 17 that connects the inlet 5 to the outlet 7.

[0062] A cylindrical body 16A is mounted within the main body 16 of the valve unit 13, which contains two valves V1 and V2 that control the communication between the fluid accumulator 9, the inlet 5 and the outlet 7, and the communication between the outlet 7 and the chamber 10 of the fluid accumulator 9, respectively.

[0063] Figures 4 and 4A (showing details of Figure 4 at a magnified scale) illustrate the "idle" state of the ABS device, i.e., when the ABS function is not needed and the solenoid 15 is de-energized. In this state, valves V1 and V2 are in the open and closed states, respectively.

[0064] Referring to Figure 4A, in the illustrated example, the valve V1 includes a sphere 50 and a spring 51 that causes the sphere 50 to return to the closed position on the valve seat 52. In the idle state illustrated in Figures 4 and 4A, i.e., when the solenoid is de-energized, the sphere 50 is held in the open position against the action of the spring 51 by the end of a pin 180 that is firmly connected to an actuator member 18 (see Figure 4) in the form of an annular disk of ferromagnetic material, which is slidably mounted within an outer cylindrical housing 151 and faces the end of the solenoid 15. When the solenoid 15 is de-energized, the actuator member 18 is held in the position (to the right when referring to Figures 4 to 7) by a spring 14 (interposed axially between the opposing surfaces of the solenoid 15 and the actuator member 18), where the pin 180 holds the sphere 50 of the valve V1 in the open position against the action of the spring 51. Therefore, in this state, the communication between the inlet 5 and the outlet 7 (i.e., between the brake lever and the brake caliper) is open.

[0065] Referring again to Figure 4A, in the illustrated example, the valve V2 includes a valve shutter formed by a conical portion 180A of a pin 180, which cooperates with a valve seat 180B defined by an annular element 180C mounted within the main body 16A.

[0066] In the state shown in Figures 4 and 4A, that is, when the solenoid is de-energized, the shutter 180A of valve V2 is in its closed position, thereby preventing communication between the outlet 7 and the accumulator chamber 10 of the fluid accumulator 9 (which is more clearly visible in Figure 6A illustrating the active operating state of the ABS device).

[0067] The annular disc constituting the actuator member 18 is made of a ferromagnetic material and has a central cylindrical cavity 18A that is traversed by the rod 12 of the movable member 11 of the fluid accumulator. The annular body constituting the actuator member 18 is firmly connected to the pin 180 that controls the valves V1 and V2 in the manner described above. The rod 12 of the movable member 11 of the fluid accumulator 9 has a grooved portion 12A in the center to avoid interference with the pin 180, so that the movement of the pin 180 and the movement of the actuator member 18 together with it, and the movement of the rod 12 and the movement of the movable member 11 of the fluid accumulator are independent of each other. For the same reason, the piston constituting the movable member 11 of the fluid accumulator 9, which consists of a cylindrical body firmly connected to the grooved portion in the center of the rod 12, has an axial cavity for the passage of the pin 180. The cylindrical body constituting the movable member 11 of the fluid accumulator 9 is provided with a sealing ring on its outer surface that cooperates with the cylindrical wall portion of the cavity of the main body 16A in which the movable member 11 is slidably mounted, and is provided with at least one further internal sealing ring that cooperates with the pin 180.

[0068] A pressure sensor P1 configured to detect the pressure in the main passage 17, and an electronic circuit board constituting the electronic controller E, are also associated with the main body 16.

[0069] As already shown with reference to Figures 4 and 4A, when the solenoid 15 is de-energized, the ABS function is not required, so the actuator member 18 is held in a position by the spring 14 in which the pin 180 keeps valve V1 open and valve V2 closed. Thus, in this situation, the inlet 5 and outlet 7 are in communication with each other through the main passage 17 and the first valve V1, while the accumulator chamber 10 of the fluid accumulator 9 is disconnected from the main passage 17. Therefore, the driver can operate the brake device F normally by acting on the brake lever.

[0070] When the electronic controller E (see Figures 2 and 3) detects the need for ABS function intervention based on a signal S that enables detection or calculation of the rotational speed of wheel R1, the electronic controller moves the actuator member 18 to its operating position shown in Figure 5 against the action of spring 14, and at the same time supplies a relatively high current level to the solenoid 15 to obtain the application of force F by the movable armature 153 to the rod 12 of the movable member 11 of the fluid accumulator 9, which attempts to maintain the movable member 11 in a position corresponding to the minimum volume of the accumulator chamber 10. In this state shown in Figures 5 and 5A, the movement of the actuator member 18 determines that the pin 180 moves (towards the left in the figures), resulting in valve V2 being in the open position and valve V1 being in the closed position, with the spherical shutter 50 being pushed to the closed position by its respective spring 51.

[0071] In this operating state, the connection between the brake lever side and the brake caliper side is broken (in the sense of interrupting communication), while the outlet 7 communicates with the accumulator chamber 10 via the valve V2. However, in the state shown in Figures 5 and 5A, the movable member 11 of the fluid accumulator 9 is not able to move away from its starting position because a solenoid supplied with a relatively high current level applies a force to the rod 12 of the movable member 11 via the movable armature 153 that is sufficient to resist such movement.

[0072] When the operating state shown in Figure 5 is reached, that is, when valves V1 and V2 are switched to the closed and open states, respectively, the electronic controller E can gradually reduce the supply current to the solenoid 15 so that the actuator member 18 remains in the operating position shown in Figure 7, while the force exerted by the movable armature 153 on the rod 12 gradually weakens, thereby allowing the movable member 11 to move away from its starting position, and consequently causing an increase in the volume of the accumulator chamber 10. This state is shown in Figures 6 and 6A.

[0073] The gradual decrease in pressure applied to the caliper is controlled by the electronic controller only as a function of the signal S indicating the rotational speed of the front wheel, and only based on the feedback signal provided by the pressure sensor P1.

[0074] In this state, if for any reason the pressure on the brake caliper side tends to be greater than the pressure on the brake lever side, valve V1 automatically opens and functions as a safety valve to release the excess pressure from the conduit connected to the outlet 7 to the conduit connected to the inlet 5.

[0075] When the need for the ABS effect ceases, the electronic controller gradually increases the supply current to the solenoid 15 again to a sufficiently high level, causing the movable armature 153 to push the rod 12 and the movable member 11 together with it back to the starting position corresponding to the minimum volume of the pressure chamber. Once this state is reached, the electronic controller E de-energizes the solenoid 15 to return the ABS device 4 to the starting state illustrated in Figure 4.

[0076] It should be noted that spring 154 is a relatively low-load spring and has the sole function of maintaining the movable armature 153 relative to the rod 12 and preventing vibration of the armature 153. In other words, spring 154 is not capable of functioning as a return spring to move the movable member 11 back to its starting position. In the ABS device of the present invention, this return action is performed by the solenoid 15. In other words, the ABS device 4 would be able to operate even if spring 154 were removed.

[0077] It should also be noted that since the actuator member 18 returns the system to its starting state due to the effect of the safety spring 14 when there is no power, the return action of the solenoid 15 does not need to guarantee a safe state (see Figures 7 and 7A).

[0078] Therefore, the spring 14 (or more springs 14) associated with the actuator member 18 is configured such that, in the absence of energization of the solenoid 15, unless there is a need for intervention of the ABS function, the actuator member 18 remains in a position that keeps the first valve V1 open and the second valve V2 closed, even in the presence of an increase in pressure in the main passage 17 determined for braking.

[0079] In the examples illustrated in Figures 4 to 8, the spring 154 is interposed between one end of the movable armature 153 protruding from the outside of the device 4 and a wall (not visible in the drawings) formed by a plastic cover that has the sole function of providing a reaction force to the spring 154 and ensuring a secure seal.

[0080] Figure 8 shows an overall view of the ABS device 4.

[0081] Figure 9 shows an example of a method for controlling the current supplied to the electrically operated valve unit of the ABS device during braking, which can be implemented within the electronic controller E of the ABS device. In the form of the embodiment illustrated here as an example, the method controls the current supplied to the solenoid 15.

[0082] The overall control method illustrated in Figure 9 is based on two parameters: the pressure CP in the conduit connected to the actuator cylinder 3 of the brake device, and the rotational speed ω of the front wheel of the vehicle to which the brake device is associated. As an alternative to pressure CP, the method may be based on the deceleration of the vehicle, which is detected by a sensor (e.g., an inertia platform) or calculated based on the detection of the vehicle's speed, for example.

[0083] In blocks 100 and 200, the pressure CP signal from sensor P1 and the rotational speed ω signal from sensor SE are processed and filtered so that the braking strength is estimated in block 101 and the vehicle speed is estimated in block 201.

[0084] Based on the braking strength estimation performed in block 101, signal 102 is sent to the supervisor module E1 of the electronic controller E, and the pressure CP is progressively adjusted (in this example, by transmitting a signal 300 that controls the current supplied to the solenoid 15 of the ABS device).

[0085] In parallel with signal 102, block 103 performs an estimation of the risk of the vehicle tipping forward, based on the estimation of braking strength in block 101 and the estimation of the vehicle speed in block 201. A signal 104 indicating this tipping risk is obtained from this and sent to supervisor E1.

[0086] In block 202, an estimate of the front wheel slip relative to the ground is performed based on the vehicle speed estimation performed in block 201 and the front wheel rotation speed value processed in block 200 (line 200A).

[0087] Based on the estimation performed in block 202, based on the signal 104 regarding the risk of forward tipping, and based on the signal 200A regarding the rotation speed of the front wheel, in block 203 the degree of adhesion of the front wheel to the ground is estimated according to a scale of values ​​that include at least a value corresponding to "high adhesion" and a value corresponding to "low adhesion".

[0088] The estimation performed in block 203 results in sending a signal 204 to the supervisor module E1 indicating a target value for the pressure CP in the actuator cylinder 3 of the brake device.

[0089] Based on the signal 102 indicating braking strength, the signal 104 indicating the risk of the vehicle rolling forward, the signal 202A indicating the estimation of the degree of contact of the vehicle's front wheels with the ground, and the signal 204 indicating a target value for pressure CP, the supervisor E1 can output a signal 300 that controls the supply current of the solenoid 15 to obtain the desired pressure CP according to the loop process, based on the feedback signal of pressure CP detected by sensor P1.

[0090] Thus, the system according to the present invention can optimally control braking by gradually varying the pressure CP during ABS function intervention and during pressure CP restoration when the ABS function is deactivated.

[0091] Figure 10 shows the temporal changes in several parameters (vehicle speed V, front wheel rotation speed ω, degree of wheel contact with the ground, pressure LP in the master cylinder 2 associated with the brake lever, and pressure CP in the actuator cylinder 3 of the brake device) during so-called "panic" braking (i.e., sudden and forceful braking resulting from an unforeseen situation) on a slippery surface.

[0092] The diagram at the top of Figure 10 shows the time-dependent fluctuations of the signals indicating the vehicle speed V and the front wheel rotation speed ω, around time t0 when the user activates the front wheel brake device.

[0093] The two signals match up to time t0, while after time t0, the wheel rotation speed ω decreases more sharply, indicating a tendency for the wheel to lock, which triggers the intervention of the ABS function. Following this intervention, the wheel rotation speed ω begins to rise again, returning to a variation that corresponds to the variation in the vehicle speed V.

[0094] The central diagram in Figure 10 shows the corresponding variation in the degree of wheel contact with the ground during braking.

[0095] The lower diagram in Figure 10 shows the corresponding fluctuations in pressure LP in the master cylinder 2 associated with the brake lever, and the corresponding fluctuations in pressure CP in the actuator cylinder 3 of the brake device (typically a brake caliper). This diagram shows that the system is configured to implement a non-abrupt, gradual fluctuation in pressure CP both when the ABS function intervenes and when it ceases to act.

[0096] Naturally, without impairing the principles of the present invention, the structural details and forms of embodiments may vary significantly with respect to those described and illustrated only as examples, as defined in the appended claims, without departing therefrom.

Claims

1. An ABS device for a hydraulic brake system of a bicycle or motorcycle, or a lightweight vehicle, which includes: - Inlet (5) connected hydraulically to the master cylinder (2) associated with the brake lever, - An outlet (7) hydraulically connected to an actuator cylinder (3) associated with a brake device intended to be associated with the wheel (R1) of the vehicle, - A fluid accumulator (9) having a pressure accumulation chamber (10) defined by a movable member (11) in a cavity, the movable member (11) is normally in a starting position corresponding to the minimum volume of the pressure accumulation chamber (10), - An electrically operated valve unit (13) - The inlet (5) and outlet (7) are in communication with each other, and the pressure accumulator (9) of the fluid accumulator (10) is disconnected in the first operating state, and - The communication between the inlet (5) and the outlet (7) is blocked, and the accumulating chamber (10) of the fluid accumulator (9) is in communication with the outlet (7) in the second operating state. An electrically operated valve unit (13) that can be switched between, and - An electronic controller (E) is configured to detect a condition requiring activation of the ABS function, and in that condition, to cause the valve unit (13) to switch from the first operating state to the second operating state, and to move the movable member (11) of the fluid accumulator (9) in a direction corresponding to an increase in the volume of the accumulator chamber (10) in order to cause a decrease in pressure in the connecting pipeline between the outlet (7) and the actuator cylinder (3) of the brake device. In an ABS device comprising, the ABS device is The electronic controller is configured to control the position of the movable member (11) of the fluid accumulator (9) in order to cause a non-abrupt, gradual fluctuation of the pressure (CP) in the conduit (8) connected to the actuator cylinder (3) of the brake device (F) both during the activation and deactivation of the ABS function, The aforementioned gradual pressure fluctuations are: - As a function of a first parameter which is the rotational speed (ω) of the wheel (R1) associated with the brake device, detected or calculated based on a signal emitted by a sensor (SE) intended to be associated with the wheel, and similarly: - A second parameter: the pressure in the actuator cylinder (3) of the brake device, Or the deceleration of the vehicle detected or calculated based on sensors intended to be associated with the vehicle. The second parameter is one of the following: as a function of Determined by the electronic controller (E) An ABS device characterized by the following features.

2. - The switching of the valve unit (13) between the first operating state and the second operating state is performed by a solenoid (15) which is operably associated with the movable member (11) of the fluid accumulator (9), and when the solenoid (15) is energized, it is: - Switching of the valve unit (13) from the first operating state to the second operating state, - The application of force (F) from the fluid accumulator (9) to the movable member (11) to push the movable member (11) toward its starting position corresponding to the minimum volume of the pressure chamber (10) Controlled by a solenoid (15) configured and positioned to cause both, When the electronic controller determines that the state in which the ABS function needs to be activated is met, the electronic controller (E) performs the following actions: - In the first phase, a relatively high level of current is supplied to the solenoid (15) in order to switch the valve unit (13) from the first operating state to the second operating state, pushing the movable member (11) of the fluid accumulator (9) to its starting position. In the subsequent second phase, the valve unit (13) remains in its second operating state, while the movable member (11) of the fluid accumulator (9) moves away from its starting position, thereby progressively reducing the current intensity of the current supplied to the solenoid (15). In the subsequent third phase, the movable member (11) of the fluid accumulator (9) returns to its starting position, determining a gradual increase in the pressure in the connecting pipeline between the outlet (7) and the actuator cylinder (3) of the brake device, while gradually increasing the current intensity of the current supplied to the solenoid (15) so that the valve unit (13) remains in its second operating state. In the subsequent fourth phase, after the movable member (11) of the fluid accumulator (9) returns to its starting position and the ABS function is no longer required, the electronic controller (E) cuts off the supply of current to the solenoid (15), thereby returning the valve unit (13) to its first operating state, while the movable member (11) of the fluid accumulator (9) remains in its starting position. It is programmed to execute The ABS device according to claim 1, characterized in that...

3. The ABS device according to claim 1, characterized in that the electronic controller (E) receives a signal from a sensor (P1) associated with the connection conduit (8) indicating the pressure in the connection conduit (8) to the actuator cylinder (3) of the brake device (F), and in the second and third phases, is configured to control the gradual fluctuation of the pressure in the connection conduit (8) to the actuator cylinder (3) of the brake device (F) as a function of a signal (S) indicating the rotational speed of the wheel (R1) to which the ABS device is intended to be associated, and based on the signal from the pressure sensor (P1).

4. The valve unit (13) is: - Main passage (17) connecting the inlet (5) to the outlet (7), - A first valve (V1) interposed in the main passage (17) between the inlet (5) and the outlet (7), which is in the open position in the first operating state of the valve unit (13), - Controlling the connection between the main passage (17) and the pressure accumulation chamber (10) of the fluid pressure accumulator (9), and the second valve (V2) which is in the closed position in the first operating state of the valve unit (13), - An actuator member (18) that is movable against the action of a spring (14) due to the energization of a solenoid (15) so as to move the first valve (V1) to the closed position and the second valve (V2) to the open position simultaneously. - If power to the solenoid is unavailable, the spring (14) associated with the actuator member (18) will return the actuator member (18) to a position that keeps the first valve (V1) open and the second valve (V2) closed, even in the presence of an increase in pressure in the main passage (17) determined by the braking action. The ABS device according to claim 1, characterized by having the following features.

5. The solenoid (15) is mounted between the inner tubular sleeve (150) and the outer cylindrical housing (151). - The stator body (152) and the movable armature (153) are arranged in axial alignment within the inner tubular sleeve (150), and the movable armature (153) is slidably mounted within the inner tubular sleeve (150) such that, after the solenoid (15) is energized, the movable armature (153) applies a force (F) to the movable member (11) in a direction that reduces the volume of the pressure accumulator (10), and is connected to the movable member (11) of the fluid accumulator (9). The ABS device according to claim 4, characterized in that...

6. The ABS device according to claim 5, characterized in that the stator body (152) has a central cylindrical cavity, within which a rod (12) that firmly connects the movable armature (153) to the movable member (11) of the fluid accumulator (9) is slidably mounted.

7. - The valve unit (13) has a valve body (16) that is firmly connected to the outer cylindrical housing (151) of the solenoid (15), - The actuator member (18) is an annular element interposed axially between one end of the stator body (152) and the body (16) of the valve unit (13), and the actuator member (18) is pushed by one or more springs (14) toward a first operating position that keeps the first valve (V1) open and the second valve (V2) closed, and is returnable to be pressed against the opposite end of the stator body (152) after energization of the solenoid (15), causing the first valve (V1) to close and the second valve (V2) to open. The ABS device according to claim 6, characterized in that...

8. The ABS device according to claim 7, characterized in that the actuator member (18) controls the first valve (V1) and the second valve (V2) using an axial pin having a portion that functions as a valve member of the second valve and an end that controls the position of the valve member of the first valve (V1).

9. A method for controlling the ABS function in the hydraulic brake system of a bicycle or motorcycle, particularly a two-wheeled bicycle, - Inlet (5) connected hydraulically to the master cylinder (2) associated with the brake lever, - An outlet (7) hydraulically connected to an actuator cylinder (3) associated with a brake device intended to be associated with the wheel of the vehicle, - A fluid accumulator (9) having a pressure accumulation chamber (10) defined by a movable member (11) in a cavity, the movable member (11) is normally in a starting position corresponding to the minimum volume of the pressure accumulation chamber (10), - An electrically operated valve unit (13) - The inlet (5) and outlet (7) are in communication with each other, and the pressure accumulator (9) of the fluid accumulator (10) is disconnected in the first operating state, and - The communication between the inlet (5) and the outlet (7) is blocked, and the pressure accumulation chamber (10) of the fluid accumulator (9) is in a second operating state in which it is in communication with the outlet (7). An electrically operated valve unit (13) that can be switched between Provided The method includes an operation using an electronic controller (E) to detect a state in which activation of the ABS function is required, and an operation that, in that state, causes the valve unit (13) to switch from the first operating state to the second operating state, and also allows the movable member (11) of the fluid accumulator (9) to move in a direction corresponding to an increase in the volume of the accumulator chamber (10) in order to cause a decrease in the pressure in the connecting pipeline between the outlet (7) and the actuator cylinder (3) of the brake device. In the method, The aforementioned method is: - The method comprises a step of using the electronic controller (E) to control the position of the movable member (11) of the fluid accumulator (9) in order to cause a gradual rather than abrupt change in the pressure (CP) in the conduit (8) connected to the actuator cylinder (3) of the brake device (F) during both the activation and deactivation of the ABS function, The aforementioned gradual pressure fluctuations are - A first parameter which is the rotational speed of the wheel (R1) associated with the brake device, detected or calculated based on a signal emitted by a sensor (SE) intended to be associated with the wheel. As a function of, and similarly, The second parameter is: The pressure (CP) in the actuator cylinder (3) associated with the brake device, Or the deceleration of the vehicle detected or calculated based on sensors intended to be associated with the vehicle. The second parameter is as a function of Determined using the aforementioned electronic controller (E) A method characterized by the following features.

10. - The switching of the valve unit (13) between the first operating state and the second operating state is operably associated with a solenoid (15) which is connected to the movable member (11) of the fluid accumulator (9), and when the solenoid (15) is energized, it is: - Switching of the valve unit (13) from the first operating state to the second operating state, - The application of force (F) from the fluid accumulator (9) to the movable member (11) to push the movable member (11) toward its starting position corresponding to the minimum volume of the pressure chamber (10) Controlled by a solenoid (15) configured and positioned to cause both, The condition requiring activation of the ABS function is determined solely based on a signal (S) indicating the rotational speed of the wheel (R1) to which the brake device (F) is intended to be associated. - If the above-mentioned condition requiring activation of the ABS function is determined, the following actions will be taken: - In the first phase, a relatively high level of current is supplied to the solenoid (15) in order to switch the valve unit (13) from the first operating state to the second operating state, pushing the movable member (11) of the fluid accumulator (9) to its starting position. In the subsequent second phase, the valve unit (13) remains in its second operating state, while the current intensity of the current supplied to the solenoid (15) is gradually reduced so that the movable member (11) of the fluid accumulator (9) moves away from its starting position to cause a gradual decrease in the pressure in the connecting pipeline between the outlet (7) and the actuator cylinder (3) of the brake device. In the subsequent third phase, the movable member (11) of the fluid accumulator (9) returns to its starting position, determining a gradual increase in the pressure in the connecting pipeline between the outlet (7) and the actuator cylinder (3) of the brake device, while gradually increasing the current intensity of the current supplied to the solenoid (15) so that the valve unit (13) remains in its second operating state. In the subsequent fourth phase, after the movable member (11) of the fluid accumulator (9) returns to its starting position and the ABS function is no longer required, the electronic controller (E) cuts off the supply of current to the solenoid (15), thereby returning the valve unit (13) to its first operating state, while the movable member (11) of the fluid accumulator (9) remains in its starting position. The method according to claim 9, characterized in that the following is performed.

11. The method according to claim 9, characterized in that the electronic controller (E) includes the operation of receiving a signal (S) from a sensor (P1) associated with the connecting conduit (8) indicating the pressure in the conduit (8) connected to the actuator cylinder (3) of the brake device (F), and the operation of controlling, in the second and third phases, the gradual fluctuation of the pressure (CP) in the conduit (8) connected to the actuator cylinder (3) of the brake device (F) as a function of the signal (S) indicating the rotational speed of the wheel (R1) associated with the ABS device, and based on the signal from the pressure sensor (P1).

12. The “cleaning” cycle includes a fifth phase for compensating for any fluid leakage during their switching from the first valve to the second valve, and in the “cleaning” cycle: The user did not apply the brakes. - Current is supplied to the solenoid (15), opening the second valve (V2), - The movable member (11) of the fluid accumulator (9) moves toward its starting position, emptying the accumulator chamber (10), Subsequently, the fluid flows from the conduit (8) of the brake device to the conduit (6) of the brake lever due to the relief function of the first valve (V1). The method according to claim 9, characterized in that

13. During the activation of the brake device, the following operations are performed via the electronic controller (E): - The signal indicating the second parameter (CP) is processed (100) to estimate the braking strength (101). - The signal indicating the first parameter (ω) is processed (200) to estimate the vehicle speed (201). Based on the estimation of braking strength (101), a signal (102) is sent to the supervisor module (E1) of the electronic controller (E) to progressively adjust the pressure (CP) in the actuator cylinder (3) of the brake device by sending a signal 300 that controls the current supplied to the electrically operated valve unit. Based on the estimation of braking strength (101) and the estimation of vehicle speed (201), the risk of the vehicle tipping forward is estimated (103), and a signal (104) indicating the tipping risk is sent to the supervisor module (E1). Based on the aforementioned estimation of the vehicle's speed (201) and based on the signal (200A) indicating the first parameter (ω), the degree of slip of the vehicle's wheels relative to the ground is estimated (202). Based on the estimation (202) of the degree of slip, based on the signal (104) indicating the risk of tipping forward, and based on the signal (200A) indicating the rotational speed of the vehicle's wheels, the wheel grip condition relative to the ground is estimated (203) according to a scale of values ​​that includes at least a value corresponding to "high grip" and a value corresponding to "low grip". Based on the estimation (203) of the degree of grip, a signal (204) indicating a target value of the pressure (CP) in the actuator cylinder (3) of the brake device is sent to the supervisor module (E1). Based on the signal (102) indicating braking strength, based on the signal (104) indicating the risk of the vehicle tipping forward, based on the signal (202A) indicating the estimation of the degree of grip of the vehicle's wheels on the ground, and based on the signal (204) indicating the target value of the pressure (CP) in the actuator cylinder of the brake device, the supervisor module (E1) generates a signal (300) that controls the current supplied to the electrically operated valve unit to achieve the target pressure (CP) in the actuator cylinder of the brake device according to a loop process, based on the feedback signal of the pressure (CP) detected by the sensor (P1). The method according to claim 9, characterized by comprising the step of performing the following.

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