Abs device for hydraulic brake system of bicycle, motorcycle or light vehicle

Abstract

An ABS device for a hydraulic braking system of a cycle or motorcycle, in particular of a bicycle, comprises an electrically driven valve unit (13) which can be switched between a first operating condition, in which a master cylinder (2) associated with a brake lever is in communication with an actuator cylinder (3) of the braking device, and a second operating condition, in which the aforesaid communication is interrupted and the actuator cylinder (3) of the braking device is in communication with a fluid accumulator (9). The switching of the valve unit (13) between the first and second operating conditions is controlled by a solenoid (15) which is operatively associated with a movable member (11) of the fluid accumulator (9) and is configured and arranged so that, when the solenoid (15) is energized, it both causes the valve unit (13) to switch from the first operating condition to the second operating condition and exerts a force (F) on the movable member (11) of the fluid accumulator (9) which tends to push the movable member (11) into a starting position corresponding to a minimum volume of an accumulation chamber (10) of the fluid accumulator (9).

Description

Technical Field

[0001] This invention relates to an ABS device for a hydraulic braking system of a bicycle or motorcycle (e.g., for an electric bicycle or a two- or three-wheeled light electric vehicle), the type of ABS device comprising:

[0002] - Inlet for hydraulic connection to the master cylinder associated with the brake lever.

[0003] - Outlet, for hydraulic connection to the actuator cylinder associated with the braking device.

[0004] - A fluid accumulator having an energy storage chamber defined within a cavity by a movable member, the movable member typically being in a starting position corresponding to the minimum volume of the energy storage chamber.

[0005] - Electrically operated valve unit that can be switched between the following states:

[0006] - First operating state, wherein the inlet and the outlet are in communication with each other, and the energy storage chamber of the fluid accumulator is isolated, and

[0007] - Second operating state, wherein the communication between the inlet and the outlet is interrupted, and the storage chamber of the fluid accumulator is in communication with the outlet, and

[0008] - An electronic controller is configured to detect a state requiring activation of the ABS function, and in said state, is further configured to switch the valve unit from a first operating state to a second operating state, and to allow the movable component of the fluid accumulator to move in a direction corresponding to an increase in the volume of the accumulator chamber, thereby reducing the pressure in the line connecting the outlet to the actuator cylinder of the braking device. Existing technology

[0009] The above-mentioned type of ABS equipment is described and illustrated, for example, in EP 3 789 256 B1.

[0010] In general, ABS devices specifically designed for hydraulic bicycle braking systems, particularly for pedal-assist bicycles, have been under development for some time. The proposed solutions have essentially been of two different types.

[0011] The first type of solution involves: a first hydraulic line for connecting the master cylinder associated with the brake lever and the actuator cylinder (typically a disc brake caliper) associated with the braking device; and a second hydraulic line for connecting the actuator cylinder of the braking device to the accumulator chamber of a passive fluid accumulator having a movable member capable of moving against the force of a spring due to the inflow of pressurized fluid into the accumulator. An electrically driven normally open valve is inserted in the first hydraulic line to allow fluid to flow from the master cylinder associated with the brake lever to the actuator cylinder associated with the braking device during normal braking. The second hydraulic line also includes an electrically driven normally closed valve to isolate the fluid accumulator from the actuator cylinder of the braking device.

[0012] Typically, the need to activate ABS is detected using sensors configured to detect a decrease in the rotational speed of the wheel associated with the braking system (usually the front wheel of a bicycle), indicating that the wheel is about to lock up. Alternatively, the need to activate ABS is detected by monitoring the load acting on the rear axle of the bicycle, checking when the rear wheel tends to lift off the ground. Another way to detect the need for ABS intervention is by directly monitoring the pressure applied to the actuator cylinders of the braking system.

[0013] When the ABS function needs to be triggered, in this known scheme of the first type, the electronic controller causes the electrically driven valve inserted in the first hydraulic line to close, thereby isolating the master cylinder associated with the brake lever and the actuator cylinder associated with the braking device, and at the same time causes the electrically driven valve inserted in the second hydraulic line to open, so that fluid can flow from the actuator cylinder of the braking device to the fluid accumulator chamber.

[0014] Examples of this first type of ABS device are described and illustrated in DE 19508915 A1. Further examples of this type of ABS device are described in DE 101 58 382 A1, EP 2 943 395 B1, WO 2017 / 115171A2, WO 2019 / 159029 A1, EP 3 753 835 B1, and EP 3 789 256 B1.

[0015] Referring still to existing technology, the second type of solution involves: a single hydraulic line for connecting the master cylinder associated with the brake lever and the actuator cylinder associated with the braking device, and an ABS device inserted in this hydraulic line that essentially constitutes an active fluid accumulator, wherein the displacement of the movable member of the accumulator in both directions is actively controlled by a motor. The accumulator chamber of this device is permanently connected to a downstream section of the hydraulic line, which is connected to the actuator cylinder of the braking device. Simultaneously, by inserting a check valve including a valve spool that is resiliently returned to the closed position, the accumulator chamber of the device is also connected to an upstream section of the hydraulic line, which is connected to the master cylinder associated with the brake lever, thereby allowing fluid to flow only from the downstream section of the hydraulic line to the upstream section. When the movable member of the device is in its initial position, the movable member of the fluid accumulator is configured to engage the valve plug of the check valve and hold it in the open position.

[0016] 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 braking device, through the device's accumulator chamber, because the one-way valve is kept open by the device's movable member in its initial position. When the need to activate the ABS function is detected (in one of the ways described above), the motor controlling the movable member instructs the movable member to move away from its initial position, thereby closing the one-way valve and increasing the volume of the accumulator chamber. This results in a decrease in pressure in the actuator cylinder of the braking device, thereby reducing or eliminating the braking effect.

[0017] Examples of this second type of scheme are described in EP 3 789 256 B1. Further examples of this type of scheme are described in documents EP 2 985 198 B1, US 4 275 934 A, and US 2020 / 324752 A1. The applicant has also developed such schemes, which are described in documents EP 4 132 841 B1 and EP 4 132 821 B1.

[0018] All the aforementioned known solutions are effective in preventing wheel lock-up during braking due to loss of traction between the wheels and the ground. However, further improvements are still needed in several aspects of this field.

[0019] The first requirement is to manufacture an ABS device that is as simple in structure, lightweight, and low in cost as possible.

[0020] Another important requirement is to ensure the reliable operation of the equipment under all operating conditions, always guaranteeing user safety, even in the event of ABS failure. In particular, it is essential to ensure that the braking system remains fully operational even if the ABS fails or the vehicle's battery is depleted, or more generally, if the ABS fails to supply power for any reason.

[0021] Another important requirement is to minimize the energy required to activate the ABS equipment.

[0022] The type of ABS device referred to at the beginning of this specification is described and illustrated in EP 3 789 256 B1 mentioned above. In this known scheme, the fluid accumulator is also associated with an electric actuator (in the form of a solenoid), which has the sole function of pushing the movable member of the fluid accumulator back to its initial position when the ABS function is no longer needed, thereby allowing fluid to flow out of the fluid accumulator without the need for a spring to return the movable member to its initial position. However, this known scheme is complex and expensive, and does not allow for precise control of the pressure in the downstream line connected to the actuator cylinder of the braking device, on which the ABS effect depends.

[0023] To address the aforementioned shortcomings, the applicant has proposed a solution, the subject of Italian patent application IT 102023 0000 14 319, filed on July 10, 2023, which was not published prior to the priority date of this application. However, further improvements are still needed in this area.

[0024] Purpose of the invention

[0025] The main objective of this invention is to effectively solve all the problems of the known technologies mentioned above.

[0026] Specifically, the first objective of this invention is to provide an ABS device that is highly efficient in operation, simple in structure, and low in cost.

[0027] Another objective of this invention is to provide an ABS device that provides sufficient safety to the user under all operating conditions, ensuring that the braking system can still operate normally even when the ABS device fails (i.e., there is no power supply).

[0028] Another objective of this invention is to provide an ABS device with minimal power consumption when activating the ABS function. Summary of the Invention

[0029] To achieve one or more of the above objectives, the present invention aims at an ABS device having all the features set forth in the opening portion of this specification, characterized in that the switching of the valve unit between its first and second operating states is controlled by a solenoid operably associated with a movable member of the fluid accumulator, and configured and arranged such that, when the solenoid is energized, the following occurs:

[0030] - The valve unit switches from the first operating state to the second operating state.

[0031] - And a force is also applied to the movable component of the fluid accumulator, which tends to push the movable component toward its starting position corresponding to the minimum volume of the accumulator chamber.

[0032] According to a preferred feature of the invention, the electronic controller is programmed to provide a variable current to the solenoid, such that:

[0033] - When the electronic controller detects a state that requires activation of the ABS function, the electronic controller is configured to perform the following operations:

[0034] In the first step, the electronic controller supplies a relatively high level of current to the solenoid, causing the valve unit to switch from a first operating state to a second operating state, while simultaneously pushing the movable component of the fluid accumulator to its initial position.

[0035] - In the subsequent second step, the electronic controller supplies a relatively low level of current to the solenoid, so that the valve unit remains in its second operating state, while the movable member of the fluid accumulator is able to move freely away from its initial position, thereby reducing the pressure in the connection between the outlet and the actuator cylinder of the braking device (the current supplied to the solenoid is modulated to a level as a function of the pressure to be obtained, and this level corresponds to a given position of the movable member until braking is completed).

[0036] - In the subsequent third step, the electronic controller resumes supplying a relatively high level of current to the solenoid, causing the movable component of the fluid accumulator to return to its initial position, while the valve unit remains in its second operating state (the current level is modulated as a function of the pressure to be obtained, which corresponds to the given position of the movable component, until braking is complete).

[0037] - In the subsequent fourth step, after the movable component of the fluid accumulator has returned to its initial position, once the ABS function is no longer needed, the electronic controller cuts off the power supply to the solenoid, causing the valve unit to return to its first operating state, while the movable component of the fluid accumulator remains in its initial position.

[0038] In the second step described above, the current flowing in the solenoid is reduced in a manner proportional to the force exerted by the fluid on the movable component of the fluid accumulator, so as to allow the movable component to move and thus gradually reduce the pressure in the brake caliper to ensure safe braking.

[0039] According to another preferred feature, the valve unit includes a safety valve configured to connect the outlet to the inlet when the valve unit is in its second operating state and if, in this state, the pressure in the outlet tends to become greater than the pressure in the inlet.

[0040] In a preferred embodiment of the present invention, the valve unit includes:

[0041] - A main passage connecting the inlet and the outlet, which is in the open position in the first operating state of the valve unit.

[0042] - A first valve, which is inserted into the main passage between the inlet and the outlet, and is in the open position in the first operating state of the valve unit.

[0043] - A second valve, which controls the connection between the main passage and the chamber of the fluid accumulator, and is in the closed position in the first operating state of the valve unit, and

[0044] - An actuator element that is able to move against the force of a spring by energizing the solenoid, thereby simultaneously bringing the first valve to the closed position and the second valve to the open position.

[0045] The present invention also relates to a method for controlling the above-mentioned ABS equipment.

[0046] The method may also include a fifth stage, which is used to compensate for any oil leakage from the first valve to the second valve during the switching between the first and second valves by means of a "cleaning" cycle, wherein:

[0047] - The user did not brake.

[0048] - Supply current to the solenoid to open the second valve.

[0049] - The movable component of the fluid accumulator reaches its initial position, emptying the accumulator chamber.

[0050] - Due to the pressure relief function of the first valve, fluid then flows from the brake caliper line to the brake lever line. Detailed Implementation

[0051] Further features and advantages of the invention will become apparent from the following description with reference to the accompanying drawings, which are provided by way of non-limiting example only, wherein:

[0052] -Figure 1 , Figure 2 Schematic diagrams of a hydraulic braking system including an ABS device according to the present invention are shown, wherein the ABS device is in a first operating state and a second operating state.

[0053] - Figure 3 , Figure 4 These are schematic diagrams of the first embodiment of the ABS device according to the present invention in a first operating state and a second operating state; and

[0054] - Figure 5 This is a perspective view of a second embodiment of the ABS device according to the present invention.

[0055] - Figure 6-9 yes Figure 5 The diagram shows cross-sectional views of the equipment under different operating conditions.

[0056] - Figure 10-13 This is a cross-sectional view of another embodiment under different operating conditions.

[0057] refer to Figure 1 , Figure 2 Reference numeral 1 generally indicates a hydraulic braking system for a bicycle, including a master cylinder 2, which is associated with a bicycle brake lever (not shown) in any known manner; an actuator cylinder 3, which is associated with a braking device, typically a disc brake caliper (not shown), in any known manner; and an ABS device, which is schematically indicated in whole by 4.

[0058] The ABS device 4 includes an inlet 5, which is hydraulically connected to the master cylinder 2 of the brake lever via a hydraulic line 6; and an outlet 7, which is hydraulically connected to the actuator cylinder 3 of the brake caliper via a hydraulic line 8.

[0059] The ABS device 4 includes a fluid accumulator 9 having an energy storage chamber 10 defined by a movable member 11, which in this example is a plunger provided with a rod 12. The plunger 11 is movable within a cavity in the body of the fluid accumulator 9 and is typically in a starting position corresponding to the minimum volume of the energy storage chamber 10. Figure 1 (As shown).

[0060] The ABS device 4 also includes a valve unit, generally indicated by 13, which is electrically operated and can be switched between a first operating state and a second operating state.

[0061] In the first operating state of valve unit 13 ( Figure 1As shown, valve unit 13 connects inlet 5 and outlet 7 to each other, allowing the braking system to operate normally in this state and enabling the user to activate the brake calipers by operating the brake lever. Valve unit 13 is typically held in place by spring device 14. Figure 1 The first operating state shown above.

[0062] By energizing solenoid 15 (described in more detail below), valve unit 13 can... Figure 1 The first operation state shown has been switched to Figure 2 The second operating state is shown in which the communication between inlet 5 and outlet 7 is interrupted, and the energy storage chamber 10 of the fluid accumulator 9 enters communication with outlet 7.

[0063] The power supply to solenoid 15 is controlled by the electronic controller E of the ABS device. The electronic controller E is configured to detect the need by receiving a signal S indicating that the ABS function needs to be activated from any known type of sensor equipped on the bicycle (e.g., an angular velocity sensor for the rotation of the bicycle's front wheel, a load sensor on the bicycle's rear wheel axle, or a pressure sensor in the brake caliper actuator cylinder).

[0064] When the electronic controller E receives a signal S indicating that the ABS function needs to be activated, the electronic controller E supplies current to the solenoid 15 in a manner that will be described in more detail below, so that the valve unit 13... Figure 1 The first operation state shown has been switched to Figure 2 The second operating state is shown.

[0065] According to an important feature of the invention, the solenoid 15 for switching the control valve unit 13 is a solenoid operatively associated with the movable member 11 of the fluid accumulator 9, and is configured and arranged such that when operated, it tends to apply a force F to the movable member 11 of the fluid accumulator 9, which tends to hold the movable member 11 in its initial position corresponding to the minimum volume of the accumulator chamber 10.

[0066] Therefore, the solenoid 15 can simultaneously control the switching of the valve unit 13 (because when the solenoid is working, the movable member 18 is attracted toward the fixed member 152) and the thrust applied to the movable member 11 of the fluid accumulator 9, which tends to push the movable member 11 toward its starting position corresponding to the minimum volume of the accumulator chamber 10.

[0067] In a practical embodiment, as will be shown below, the solenoid 15 is coaxially mounted around the fluid accumulator 9 in a position that is also acted upon to cooperate with the actuator components (described in detail below) in the operating state of the control valve unit 13.

[0068] The pressure sensor P is adapted to detect the pressure in the brake caliper actuator cylinder 3 and send a signal indicating the detected pressure to the electronic controller E.

[0069] exist Figure 1 , Figure 2 The operation of the ABS equipment is illustrated below.

[0070] During normal use of the bicycle, when the ABS function is not required, solenoid 15 is not powered, and valve unit 13 is in a state of... Figure 1 The first operating state is shown. In this state, operating the brake lever causes fluid to be delivered from the master cylinder 2, through line 6, valve unit 13, and line 8, to the actuator cylinder 3 of the brake caliper, thereby activating it normally.

[0071] Spring 14 is configured to balance the hydraulic pressure generated by the brake lever side pressure even when the user presses it with maximum force.

[0072] If the electronic controller E receives a signal S indicating that ABS function intervention is required, in the first step, the electronic controller E supplies a relatively high level of current to the solenoid 15 to switch the valve unit 13 from the first operating state to the second operating state, but pushes the movable member 11 of the fluid accumulator 9 towards... Figure 1 As shown in its initial position, the energy storage chamber 9 receives pressurized fluid from the line 8 connected to the actuator cylinder 3 of the brake caliper.

[0073] In the subsequent second step, the electronic controller supplies a relatively low level of current to the solenoid (capable of modulating the current by gradually decreasing it from a high level to a low level), so that the valve unit 13 remains... Figure 2 The second operating state is shown, while the movable component of the fluid accumulator moves from its initial position (e.g., Figure 2 (As shown), this is because the pressure of the fluid reaching chamber 10 generates a force that exceeds the force applied to the movable member 11 by solenoid 15. The increase in the volume of chamber 10 leads to a decrease in pressure in the line 8 connected to the brake caliper actuator cylinder 3, thereby producing an ABS effect to prevent the wheels from locking up during braking.

[0074] In this state, if for any reason the pressure in the downstream line 8 tends to exceed the pressure in the upstream line 6, the check valve, which is part of the valve unit 13, automatically opens, connecting the downstream line 8 of the actuator cylinder 3 connected to the brake caliper to the upstream line 6 of the actuator cylinder 2 connected to the rod.

[0075] During the ABS activation phase, the electronic controller E controls the current supplied to the solenoid 15 based solely on the signal provided by the pressure sensor P, in order to establish a certain pressure level in the actuator cylinder of the brake caliper, thus eliminating the need for a sensor to determine the position of the movable component of the fluid accumulator.

[0076] In the subsequent third step, the electronic controller E resumes supplying a relatively high level of current to the solenoid (e.g., by modulating the current from a minimum to a maximum value), causing the movable component 11 of the fluid accumulator 9 to return to its initial position due to the increased force F applied by the solenoid (e.g., ...). Figure 1 (as shown), while valve unit 13 remains in its Figure 2 The second operating state is shown.

[0077] In the subsequent fourth step, after the movable component 11 of the fluid accumulator 9 returns to its initial position, once the ABS function is no longer needed, the electronic controller E interrupts the power supply to the solenoid 15, causing the valve unit to return to its initial position. Figure 1 The first operating state is shown, while the movable component of the fluid accumulator 9 remains in its... Figure 1 The starting position is shown.

[0078] Preferably, a fifth step is also provided to compensate for any fluid leakage from the first valve to the second valve during the switching of the first and second valves via a "cleaning" cycle, wherein:

[0079] - The user did not brake.

[0080] - Power is supplied to solenoid 15 to open the second valve V2.

[0081] - The movable component 11 of the fluid accumulator 9 reaches its initial position, emptying the energy storage chamber 10.

[0082] - Due to the pressure relief function of the first valve V1, fluid then flows from the brake caliper line 8 to the brake lever line 6.

[0083] Now for reference Figure 3 , Figure 4 This relates to the first specific embodiment of the invention, as shown in these figures, and... Figure 1 , Figure 2 The parts shown in the figure that correspond to each other in function use the same reference numerals.

[0084] Figure 3 An example of an ABS device 4 according to the invention is shown, wherein the valve unit 13, the fluid accumulator 9 and the solenoid 15 are interconnected within a common structure.

[0085] Specifically, in this exemplary embodiment, a solenoid 15 is installed between an inner tubular sleeve 150 and an outer cylindrical housing 151. A stator body 152 made of ferromagnetic material is disposed within the inner tubular sleeve 150, and this stator body 152 is passed through a central cylindrical cavity 152A, in which a plunger rod 12 constituting the movable member 11 of the fluid accumulator 9 is slidably mounted. A movable armature 153 made of ferromagnetic material is slidably mounted within the tubular sleeve 150, and this movable armature 153 contacts the end of the rod 12 relative to the plunger 11 and is held in contact with the rod 12 by a vibration damping spring 154.

[0086] Still referencing Figure 3 , Figure 4 The accumulator chamber 10 of the fluid accumulator 9 is defined in the body 16 of the valve 13 assembly. The body 16 also defines an inlet 5 for hydraulic connection to the master cylinder 2 of the brake lever, an outlet 7 for hydraulic connection to the actuator cylinder 3 of the brake caliper, and a main passage 17 connecting the inlet 5 and the outlet 7.

[0087] Refer again Figure 3 , Figure 4 The main body 16 of the valve unit 13 includes a first valve V1, which is inserted into the main passage 17 and connects the inlet 5 to the outlet 7; and a second valve V2, which controls the connection between the main passage 17 and the energy storage chamber 10 of the fluid energy storage device 9.

[0088] As will be described in detail below, when the ABS equipment is in Figure 1 The first operating state shown is that when the solenoid 15 is not energized, valve V1 is in the open state and valve V2 is in the closed state.

[0089] Valve unit 13 includes actuator element 18, which is configured to overcome the action of spring 14 due to energization of solenoid 15, thereby simultaneously switching valve V1 to the closed state and valve V2 to the open state. Figure 3 In the specific example shown, the actuator element 18 is in the form of an annular plate made of ferromagnetic material, and the spring 14 is a helical spring, axially inserted between one end of the plate 18 and the stator body 152, such that the spring 14 tends to press the plate 18 against the end face of the valve unit 13 body 16 facing the stator body 152. Figure 3 and Figure 4 As shown, in the example illustrated, plate 18 is rigidly connected to two pins S1 and S2, which control the operating states of valves V1 and V2, respectively. Specifically, in the example illustrated, valve V1 is composed of a ball that has been spring-returned to its seat in the closed state, and valve core S1 is configured to... Figure 3In the first operating state shown (in which solenoid 15 is not energized), the ball of valve V1 is pushed to the open position. Valve spool S2 is configured to serve as the valve spool element of valve V2 and is spring-returned to the open position of valve V2.

[0090] Associated with the valve unit body 13 is a pressure sensor P, which is configured to sense the pressure in the main passage 17.

[0091] exist Figure 3 , Figure 4 In this embodiment, the ABS device 4 is operated as follows.

[0092] When solenoid 15 is not energized, ABS device 4 is in the first operating state, such as... Figure 3 As shown, corresponding to Figure 1 The schematic diagram shows the state. In this state, spring 14 holds plate 18 in contact with one side of the body 16 of valve unit 13, such that pin S1 keeps valve V1 open while pin S2 is in the closed position of valve V2. Therefore, in this state, ABS device 4 connects inlet 5 to outlet 7 through main passage 17, thus enabling the braking system to operate normally. Whenever the brake lever is operated, pressurized fluid is delivered from master cylinder 2 of the brake lever through main passage 17 of ABS device 4 to actuator cylinder 3 of brake caliper ( Figure 1 In this state, it is precisely because the second valve V2 is closed that the movable member 11 is kept in its stationary position (corresponding to the position of minimum volume of the energy storage chamber 10) without any energy consumption, which is a fundamental advantage of the present invention.

[0093] If the electronic controller E of the ABS device receives a signal S indicating that the ABS effect needs to be triggered ( Figure 1 , Figure 2 The electronic controller E supplies a relatively high level of current to the solenoid, sufficient to achieve two effects:

[0094] - A plate 18 made of ferromagnetic material is attracted by the magnetic field generated by the solenoid 15 and abuts against the adjacent end of the stator body 152, causing valve core S1 to move to the position corresponding to the closed valve V1, and valve core S2 to move to the position corresponding to the open valve V2. This state is as follows: Figure 4 As shown;

[0095] - At the same time, the magnetic field generated by the solenoid 15 causes the movable armature 153 to push against the rod 12 of the movable member 11 of the fluid accumulator 9 in a direction that tends to hold the movable member 11 in a position corresponding to the minimum volume of the energy storage chamber 10.

[0096] Once the two valves V1 and V2 are switched to the following positions... Figure 4In the closed and open states shown, the electronic controller E reduces the current level supplied to the solenoid 15 to a low level. At this low level, the force F applied to the rod 12 by the movable armature 153 is insufficient to resist the movement of the movable member 11 of the fluid accumulator in the direction corresponding to the increase in volume of the accumulator chamber 10 (to the right, see the attached figure). This is due to the fluid from the downstream line 8 of the brake caliper actuator cylinder entering the accumulator chamber 10 through valve V2. The pressure in the valley line 8, which is connected to the caliper actuator cylinder 3, is... Figure 1 , Figure 2 The current supplied to solenoid 15 is reduced, thereby achieving the ABS effect. Preferably, the transition from a high value to a low value is achieved by gradually reducing the current supplied to solenoid 15. This also allows the electronic controller E to achieve the desired ABS effect by modulating the supply current of solenoid 15 in any desired manner.

[0097] Once the ABS effect is no longer needed, the electronic controller increases the current level supplied to solenoid 15, preferably gradually, until it returns to a relatively high current level. This increases the force F applied by the movable armature 153 and pushes the movable member 11 back to its initial position, which corresponds to the minimum volume of the energy storage chamber 10. Once this state is reached, solenoid 15 is completely de-energized, allowing plate 18 to return under the thrust of spring 14. Figure 3 The valve is positioned at rest, thus switching valve V1 back to the open state and valve V2 back to the closed state.

[0098] In the operation state where the ABS effect is activated ( Figure 4 If the pressure in the main passage 17, which is connected to the downstream line 8 on the brake caliper side, tends to become greater than the pressure in the upstream line 6 on the brake lever side, valve V1 will act as a safety valve because it will open due to the aforementioned pressure difference.

[0099] Figure 5-9 A second specific example relating to an embodiment of the ABS device according to the present invention. In these figures, with Figure 1 , 2 and Figure 3 , 4 The same or equivalent parts shown are indicated by the same reference numerals.

[0100] exist Figure 5-9In this embodiment, the solenoid 15 is also housed between the inner tubular sleeve 150 and the outer cylindrical housing 151. Similarly, a stator 152 is disposed inside the cylindrical sleeve 151, through which a central cylindrical cavity 152A passes, and the rod 12 of the plunger constituting the movable member 11 of the fluid accumulator 9 is slidably mounted in the cavity. Similarly, a cylindrical movable armature 153 is disposed inside the tubular sleeve 150, which is held against the end of the rod 12 opposite to the plunger 11 by a vibration damping spring 154.

[0101] Also in Figure 5-9 In the example, the body 16 of valve unit 13 defines an inlet 5 for hydraulic connection to the master cylinder of the brake lever, an outlet 7 for hydraulic connection to the actuator cylinder of the brake caliper, and a main passage 17 connecting the inlet 5 and the outlet 7. Similarly, two valves V1 and V2, respectively in an open and closed state when the solenoid is not energized, are integrated in the body 16 of valve unit 13. Similarly, in its open state, valve V1 allows free communication between the inlet 5 and the outlet 7 through the main passage 17. Similarly, in its closed state, valve V2 prevents the side of the main passage 17 connected to the outlet 7 from communicating with the accumulator chamber 10 of the fluid accumulator 9. Figure 7 The best view is shown in the second operating state of the ABS equipment.

[0102] Figure 5-9 Examples and Figure 3 , 4 The main difference between the examples is that, Figure 5-9 In the example case, the two valves V1 and V2 are aligned along the same axis, rather than arranged along two parallel and spaced-apart axes.

[0103] exist Figure 5-9In the example, the actuator element 18, which switches valves V1 and V2 to the closed and open states respectively due to the energization of solenoid 15, is an annular metal body made of ferromagnetic material, slidably mounted within the outer cylindrical housing 151 of the solenoid. The annular body 18 has a central cylindrical cavity 18A through which the rod 12 of the movable member 11 of the fluid accumulator passes, and an outer annular portion that contacts the adjacent surface of the body 16 of the valve unit 13, driven by a series of helical springs 14. The annular body constituting the actuator element 18 is rigidly connected to an axial pin S2 of the valve core (ball in the example) controlling the second valve V2. The rod 12 of the movable member 9 of the fluid accumulator has a central slotted portion 12A to avoid interference with the pin S2; therefore, the movement of the pin S2 (along with the actuator element 18) is independent of the movement of the rod 12 and the movable member 11 of the fluid accumulator. For the same reason, the plunger of the movable member 11 constituting the fluid accumulator 9 (in this case, a cylinder rigidly connected to the central slotted portion of the rod 12) has an axial cavity through which the pin S2 passes. The cylinder constituting the movable member 11 of the fluid accumulator 9 has a sealing ring on its outer surface that engages with the cylindrical wall of the main cavity 16 (in which the movable member 11 is slidably mounted) and at least one additional inner sealing ring that engages with the pin S2.

[0104] In a preferred example, valve spool S2 is rigidly connected to the ball valve spool of the second valve V2. Furthermore, valve spool S1 is operably inserted between the ball valve plug of valve V2 and the ball valve plug of valve V1, the ball valve plug of valve V1 being returned to the closed position by a corresponding helical spring.

[0105] like Figure 6-9 As shown in this embodiment, valves V1 and V2 are housed within coaxial cavities formed on two opposing surfaces of the body 16 of valve unit 13. These cavities communicate with cavities formed in the body 16 and orthogonal to the alignment axes of valves V1 and V2, defining a portion of a main passage 17 connecting outlet 7 and inlet. In the specific embodiment shown here, outlet 7 is defined by a connecting element 70 rigidly connected to the body 16 of valve unit 13, and a cylinder 71 having an axial bore is tightly fitted within the connecting element 70, the axial bore defining a portion of the main passage 17 communicating with a radial bore through a circumferential groove in the cylinder 71, defining an annular chamber communicating with outlet 7.

[0106] and Figure 3 , 4 Similar to the scheme, the main body 16 is also associated with a pressure sensor P, which is configured to detect the pressure in the main passage 17.

[0107] according to Figure 5-8 The operation of the ABS equipment in the illustrated embodiment is the same as described above. Figure 1 , 2 and Figure 3 , 4 The operations shown are very similar.

[0108] When solenoid 15 is not energized, the equipment is in its first operating state, such as... Figure 6 As shown. In this state, actuator element 18 is held in its illustrated position by spring 14 against the adjacent surface of body 16, whereby pin S2 holds valve spool V2 in the closed state. Therefore, pin S1, inserted between valve spool V2 and valve spool V1, holds valve spool V1 in the open state, overcoming the action of the corresponding spring. Thus, in this case, inlet 5 and outlet 7 are connected to each other via main passage 17 and first valve V1, while the storage chamber 10 of fluid accumulator 9 is isolated relative to the main passage 17.

[0109] When electronic controller E (see Figure 1 , Figure 2 When intervention requiring ABS is detected, the electronic controller energizes solenoid 15 at a relatively high current level to move actuator element 18 to... Figure 7 The operating position shown, simultaneously overcoming the action of the spring 14 and the force F applied by the rod 12 of the movable member 11 of the fluid accumulator 9 by the movable armature 153 abutting against it, tends to hold the movable member 11 in a position corresponding to the minimum volume of the accumulator chamber 10. In this state, as Figure 7 As shown, the displacement of actuator element 18 causes displacement of valve core S2 (refer to the left in the attached figure), which in turn causes valve V2 to open and causes displacement of valve core S1, which in turn causes valve V1 to close, with its ball valve plug pushed into the closed position by the corresponding helical spring. In this operating state, the side of the main passage 17 that communicates with outlet 7 is connected to the accumulator chamber 10 via valve V2. However, the movable member 11 of the fluid accumulator 9 cannot move away from its starting position because the solenoid energized at a relatively high current level applies sufficient force to the rod 12 of the movable member 11 via the movable armature 153 to resist such movement.

[0110] Once reached Figure 7 The operating state shown indicates that once valves V1 and V2 are switched to the closed and open states respectively, the electronic controller can reduce the supply current of solenoid 15 to a low level, preferably by gradually reducing it to a low level, so that actuator element 18 remains... Figure 7 The operating position is shown, and the moving armature 153 applies a small force to the rod 12, thereby allowing the movable member 11 to move away from its starting position, which in turn causes the volume of the energy storage chamber 10 to increase (see...). Figure 8This produces the ABS effect. In this state, if, for any reason, the pressure on the brake caliper side tends to become greater than the pressure on the brake lever side, valve V1 will automatically open, acting as a safety valve to release excess pressure from the line connected to outlet 7 to the line connected to inlet 5.

[0111] When the ABS effect is no longer needed, the electronic controller increases the supply current to the solenoid 15 again, preferably gradually, to a sufficiently high level so that the moving armature 153 pushes the rod 12 and the associated movable member 11 back to the starting position, which corresponds to the minimum volume of the accumulator chamber. Once this state is reached, the electronic controller de-energizes the solenoid 15, causing the ABS device 4 to return to normal operation. Figure 6 The initial state is shown.

[0112] Figure 10-13 Another form of actuation is shown, which is similar to Figure 5-9 The difference in actuation methods lies in the different arrangements of the fluid accumulators. In these figures, the same parts are indicated by the same reference numerals.

[0113] exist Figure 10-13 In a variant, the rod 120 carrying the plunger 110 (also stationary, and therefore stationary like the stator body 152) is rigidly connected to the stator body 152, and the plunger 110 is slidably engaged within the cavity 153A of the movable armature 153. Thus, the stationary plunger 110 defines a chamber within the cavity 153A, the volume of which varies with the movement of the movable armature 153 relative to the stationary plunger 110, serving as the energy storage chamber 10 of the fluid accumulator 9. Therefore, in this variant, the fluid accumulator 9 is constituted by the movable armature 153 itself, which is controlled by the solenoid 15. The energy storage chamber 10 within the movable armature 153 communicates with the valve unit 13 via passages formed within the rod 120 of the stator body 152 and within the actuator member 18. In the illustrated example, the actuator member 18 has an annular body with a tubular rod 180, as... Figure 5-9 As shown, the tubular rod 180 terminates in a head 181, which is slidably mounted within the axial cavity 160 of the body 16 of the valve unit 13.

[0114] Figure 10-13 Operation of actuation form and Figure 5-9 The operation of the actuation methods is very similar.

[0115] Figure 10 The diagram shows the normal state of the ABS when it is not activated, with valve V1 open to allow communication between inlet 5 and outlet 7, while valve V2 is closed so that chamber 10 of fluid accumulator 9 is not connected to the main passage 17.

[0116] Figure 11 The initial state of solenoid 15 triggered at maximum supply current is shown, which causes valves V1 and V2 to switch due to the movement of actuator component 18.

[0117] Figure 12 The current modulation phase of the solenoid 15 is shown, which causes the movable armature 153 to move, thereby increasing the volume of the energy storage chamber 10.

[0118] Figure 13 The diagram illustrates a state in which, for example, power to solenoid 15 is interrupted during the modulation phase, causing the actuator component to be returned to its rest position by spring 14, where the actuator component closes valve V2 and opens valve V1, allowing normal braking.

[0119] It should be noted that among all the actuation methods described above, spring 154 is a relatively low-load spring, and its sole function is to hold the movable armature 153 against the rod 12 to prevent vibration of the armature 153. In other words, spring 154 does not function as a return spring to return the movable member 11 to its initial position. In the ABS device of the present invention, this return action is performed by solenoid 15. In other words, the ABS device 4 can operate even without spring 154.

[0120] It should also be noted that the return function of solenoid 15 is not intended to ensure a safe state. This is because, due to the action of safety spring 14, movable member 18, even without power supply, can bring the system back to the initial state (brake lever side line 6 is connected to brake caliper side line 8) regardless of the position of movable member 152A. Therefore, in all the above actuation methods, spring 14 associated with actuator element 18 is configured such that, even without solenoid 15 being energized, even if there is a pressure rise in the main passage 17 caused by braking, actuator element 18 remains in the position that keeps first valve V1 open and second valve V2 closed, as long as ABS intervention is not required.

[0121] exist Figure 5-9 In the example shown, spring 154 is inserted between the protruding end of movable armature 153 outside device 4 and a wall made of a plastic cover (not visible in the figures), the sole function of which is to provide a reaction force for spring 154 and ensure a seal.

[0122] Of course, while the principles of the invention remain unchanged, the construction details and embodiments may vary considerably from what is described and illustrated herein by way of example only, without departing from the scope of the invention as defined by the appended claims.

Claims

1. An ABS device for a hydraulic braking system of a bicycle, motorcycle, or light vehicle, comprising: - Inlet (5), for hydraulic connection to the master cylinder (2) associated with the brake lever. - Outlet (7), for hydraulic connection to actuator cylinder (3) associated with braking equipment. - A fluid accumulator (9) having an energy storage chamber (10) defined within a cavity by a movable member (11), the movable member (11) typically being in a starting position corresponding to the minimum volume of the energy storage chamber (10). - Electrically operated valve unit (13) that can switch between the following states: - First operating state, wherein the inlet (5) and the outlet (7) are in communication with each other, while the energy storage chamber (10) of the fluid accumulator (9) is isolated, and - Second operating state, wherein the communication between the inlet (5) and the outlet (7) is interrupted, and the energy storage chamber (10) of the fluid accumulator (9) is in communication with the outlet (7), and - An electronic controller (E) is configured to detect a state requiring activation of the ABS function, and in said state, is further configured to switch the valve unit (13) from the first operating state to the second operating state, and to enable 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), thereby reducing the pressure in the line connecting the outlet (7) to the actuator cylinder (3) of the braking device. The ABS device is characterized in that the switching of the valve unit (13) between the first operating state and the second operating state is controlled by a solenoid (15), the solenoid (15) being operatively associated with a movable member (11) of the fluid accumulator (9), and the solenoid (15) being configured and arranged such that when the solenoid (15) is energized, the following occurs: - The valve unit (13) switches from the first operating state to the second operating state. - And a force (F) is also applied to the movable member (11) of the fluid accumulator (9), which tends to push the movable member (11) toward its starting position corresponding to the minimum volume of the accumulator chamber (10).

2. The ABS equipment according to claim 1, characterized in that, The electronic controller (E) is programmed to supply a variable current to the solenoid (15) such that: When the electronic controller (E) detects a state requiring activation of the ABS function, the electronic controller (E) is configured to perform the following operations: - In the first step, the electronic controller (E) supplies a relatively high level of current to the solenoid (15) to switch the valve unit (13) from the first operating state to the second operating state, while simultaneously pushing the movable member (11) of the fluid accumulator (9) to its initial position. - In the subsequent second step, the electronic controller (E) supplies a relatively low level of current to the solenoid (15), causing the valve unit (13) to remain in its second operating state, while the movable member (11) of the fluid accumulator (9) is able to move freely away from its initial position, thereby reducing the pressure in the line connecting the outlet (7) to the actuator cylinder (3) of the braking device. - In the subsequent third step, the electronic controller (E) resumes supplying a relatively high level of current to the solenoid (15), causing the movable component (11) of the fluid accumulator (9) to return to its initial position, while the valve unit (13) remains in its second operating state. - In the subsequent fourth step, after the movable component (11) of the fluid accumulator (9) returns to its initial position, and once the ABS function is no longer needed, the electronic controller (E) interrupts the power supply to the solenoid (15), causing the valve unit (13) to return to its first operating state, while the movable component (11) of the fluid accumulator (9) remains in its initial position.

3. The ABS equipment according to claim 1, characterized in that, It includes a pressure sensor (P) configured and arranged to sense the pressure in the actuator cylinder (3) of the braking device, and is characterized in that the electronic controller (E) controls the current supplied to the solenoid (15) based solely on the signal provided by the pressure sensor (P) during the activation of the ABS function, without the need to provide a position sensor for the movable member (11) of the fluid accumulator (9).

4. The ABS equipment according to claim 1, characterized in that, The valve unit (13) includes a safety valve configured to connect the outlet (7) to the inlet (5) when the valve unit (13) is in its second operating state and if, in this state, the pressure at the outlet (7) tends to become greater than the pressure at the inlet (5).

5. The ABS equipment according to claim 1, characterized in that, The valve unit (13) includes: - Main passage (17) connecting the inlet (5) and the outlet (7). - A first valve (V1) is inserted into the main passage (17) between the inlet (5) and the outlet (7) and is in the open position in the first operating state of the valve unit (13). - A second valve (V2) controls the connection between the main passage (17) and the energy storage chamber (10) of the fluid accumulator (9), and is in the closed position in the first operating state of the valve unit (13). - The actuator element (18) is able to move against the action of the spring (14) by energizing the solenoid (15), thereby simultaneously bringing the first valve (V1) to the closed position and the second valve (V2) to the open position.

6. The ABS equipment according to claim 1, characterized in that, The spring (14) associated with the actuator element (18) is configured such that, even when the solenoid (15) is not energized, the actuator element (18) remains in a position where the first valve (V1) is kept open and the second valve (V2) is closed, provided that the ABS function is not required to intervene, even if there is a pressure rise in the main passage (17) caused by braking operation.

7. The ABS equipment according to claim 5, characterized in that: - The solenoid (15) is installed between the inner tubular sleeve (150) and the outer cylindrical shell (151). - A stator body (152) and a movable armature (153) are axially aligned inside the inner tubular sleeve (150). The movable armature (153) is slidably mounted inside the inner tubular sleeve (150) and connected to the movable member (11) of the fluid accumulator (9), such that when the solenoid (15) is energized, the movable armature (153) applies a force (F) to the movable member (11) in the direction of decreasing volume of the accumulator chamber (10).

8. The ABS equipment according to claim 5, characterized in that, The stator (152) has a central cylindrical cavity (152A), and the rod (12) of the movable member (11) of the fluid accumulator (9) is slidably mounted in the central cylindrical cavity (152A).

9. The ABS equipment according to claim 5, characterized in that, The rod carrying the plunger (110) is rigidly connected to the stator body (152), and the plunger (110) is disposed in the cavity (153A) of the movable armature (153) in a sliding engagement manner so as to define a variable volume chamber within the movable armature (153), the variable volume chamber serving as the energy storage chamber (10) of the fluid energy storage device (9).

10. The ABS equipment according to claim 5, characterized in that, The energy storage chamber (10) within the movable armature (153) is connected to the valve unit (13) via passages formed within the rod of the stator body (152) and within the actuator component (18).

11. The ABS equipment according to claim 7, characterized in that: - The valve unit (13) includes a valve body (16) which is rigidly connected to the outer cylindrical housing (151) of the solenoid (15). - The actuator component (18) is an annular component that is axially inserted between one end of the stator body (152) and the body (16) of the valve unit (13). The actuator component (18) is pushed to a first operating position by one or more springs (14). In the first operating position, the actuator component (18) holds the first valve (V1) open and the second valve (V2) closed. The actuator component (18) is adapted to close the first valve (V1) and open the second valve (V2) in response to being pushed against the opposing end of the stator body (152) due to the energization of the solenoid (15).

12. The ABS equipment according to claim 11, characterized in that, The actuator element (18) controls the first valve (V1) and the second valve (V2) by means of the parallel and spaced-apart pins (S1, S2).

13. The ABS equipment according to claim 11, characterized in that, The actuator element (18) controls the first valve (V1) and the second valve (V2) by means of pins (S1, S2) that are aligned with each other and extend from each other.

14. A method for controlling the ABS function in a hydraulic braking system of a bicycle or motorcycle, particularly a bicycle, wherein the system includes: - Inlet (5), for hydraulic connection to the master cylinder (2) associated with the brake lever. - Outlet (7), for hydraulic connection to actuator cylinder (3) associated with braking equipment. - A fluid accumulator (9) having an energy storage chamber (10) defined within a cavity by a movable member (11), the movable member (11) typically being in a starting position corresponding to the minimum volume of the energy storage chamber (10). - Electrically operated valve unit (13) that can switch between the following states: - First operating state, wherein the inlet (5) and the outlet (7) are in communication with each other, while the energy storage chamber (10) of the fluid accumulator (9) is isolated, and - Second operating state, wherein the communication between the inlet (5) and the outlet (7) is interrupted, and the storage chamber (10) of the fluid accumulator (9) is connected to the outlet (7). The method includes detecting a state requiring ABS activation via an electronic controller (E), and in that state, switching the valve unit (13) from a first operating state to a second operating state, and also allowing 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), thereby reducing the pressure in the line connecting the outlet (7) to the actuator cylinder (3) of the braking device. The method is characterized in that the switching of the valve unit (13) between the first operating state and the second operating state is controlled by a solenoid (15), the solenoid (15) being operatively associated with the movable member (11) of the fluid accumulator (9), and the solenoid (15) being configured and arranged such that when the solenoid (15) is energized, the following occurs: - The valve unit (13) switches from the first operating state to the second operating state. - And a force (F) is also applied to the movable member (11) of the fluid accumulator (9), which tends to push the movable member (11) toward its starting position corresponding to the minimum volume of the accumulator chamber (10).

15. The method according to claim 10, characterized in that, The method includes supplying a variable current to the solenoid (15) via the electronic controller (E), such that: When the electronic controller (E) detects a state requiring activation of the ABS function, the electronic controller (E) is configured to perform the following operations: - In the first step, the electronic controller supplies a relatively high level of current to the solenoid (15) to switch the valve unit (13) from the first operating state to the second operating state, while simultaneously pushing the movable member (11) of the fluid accumulator (9) to its initial position. - In the subsequent second step, the electronic controller (E) supplies a relatively low level of current to the solenoid (15), causing the valve unit (13) to remain in its second operating state, while the movable member (11) of the fluid accumulator (9) is able to move freely away from its initial position, thereby reducing the pressure in the line connecting the outlet (7) to the actuator cylinder (3) of the braking device. - In the subsequent third step, the electronic controller resumes supplying a relatively high level of current to the solenoid (15), causing the movable component (11) of the fluid accumulator (9) to return to its initial position, while the valve unit (13) remains in its second operating state. - In the subsequent fourth step, after the movable component of the fluid accumulator returns to its initial position and once the ABS function is no longer needed, the electronic controller (E) interrupts the power supply to the solenoid, causing the valve unit (13) to return to its first operating state, while the movable component (11) of the fluid accumulator (9) remains in its initial position.

16. The method according to claim 11, characterized in that, The method includes a fifth stage for compensating for any fluid leakage from the first valve to the second valve during the switching of the first valve and the second valve by means of a "cleaning" cycle, wherein: - The user did not brake. - Supply current to the solenoid (15) to open the second valve (V2). - The movable component (11) of the fluid accumulator (9) reaches its starting position and empties the accumulator chamber (10). - Due to the pressure relief function of the first valve (V1), fluid then flows from the line (8) of the braking device to the line (6) of the brake lever.

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