Anti-lock braking system, vehicle and method for braking a vehicle

Abstract

An anti-lock braking system (12) for vehicles is specified, in particular for vehicles driven by muscle power and / or motor power, comprising a first hydraulic connection (18) to which a brake force transmitter (14) can be connected, a second hydraulic connection (20) to which a brake force receiver (16) can be connected, wherein the first hydraulic connection (18) is connected to the second hydraulic connection (18) via a hydraulic path (22), a 2 / 2-way valve (24) arranged between the first hydraulic connection (18) and the second hydraulic connection (20) in the hydraulic path (22), and a reversibly operable hydraulic pump (28) arranged fluidically between the 2 / 2-way valve (24) and the second hydraulic connection (20), which in delivery mode delivers hydraulic fluid into the hydraulic path (22) and in suction mode draws hydraulic fluid from the hydraulic path (22), wherein the hydraulic pump (28) is driven by an electric motor (31).Furthermore, a vehicle and a method for braking a vehicle (10) are specified.

Description

[0001] The invention relates to an anti-lock braking system for vehicles, in particular for vehicles propelled by muscle power and / or motor power, for example, bicycles and electric bicycles. The vehicle can be a two-wheeler or a three-wheeler. Furthermore, the invention relates to a vehicle with an anti-lock braking system and a method for braking a vehicle.

[0002] Passive anti-lock braking systems with valves and a pressure accumulator are known for vehicles, especially smaller vehicles such as bicycles and electric bicycles. However, such passive systems are not capable of increasing brake pressure independently, so these systems require repeated actuation of a brake force sensor.

[0003] Active anti-lock braking systems are also known, which control brake pressure based on brake pressure, wheel speed, and the position of a control piston. However, such systems require the position of the control piston to be detected by a sensor, making the system complex and costly to manufacture.

[0004] It is therefore an object of the invention to provide an anti-lock braking system for vehicles which is simple and inexpensive to manufacture.

[0005] This object is achieved according to the invention by an anti-lock braking system for vehicles, in particular for vehicles driven by muscle power and / or engine power, with a first hydraulic connection to which a brake force transmitter can be connected, a second hydraulic connection to which a brake force receiver can be connected, wherein the first hydraulic connection is connected to the second hydraulic connection via a hydraulic path, a 2 / 2-way valve which is arranged between the first hydraulic connection and the second hydraulic connection in the hydraulic path, and a reversibly operable hydraulic pump which is arranged fluidically between the 2 / 2-way valve and the second hydraulic connection and which, in delivery mode, delivers hydraulic fluid into the hydraulic path and, in suction mode, sucks hydraulic fluid out of the hydraulic path, wherein the hydraulic pump is driven by an electric motor.

[0006] When the anti-lock braking system is activated, the hydraulic pump makes it particularly easy to modulate the brake pressure by changing the flow direction of the hydraulic pump, which enables the system to both actively reduce and actively increase the brake pressure.

[0007] At the same time, the design of the anti-lock braking system is particularly simple. More specifically, a sensor for detecting the position of a control piston is no longer required.

[0008] The brake force sensor is, for example, a manually operated brake lever or a brake pedal.

[0009] The brake force sensor, for example, is a brake piston that is pressurized with hydraulic fluid.

[0010] The 2 / 2-way valve is preferably normally open. When the 2 / 2-way valve is open, the first hydraulic port and the second hydraulic port are fluidly connected, allowing brake pressure to be built up in the brake piston by means of a brake force sensor connected to the first hydraulic port. The 2 / 2-way valve's normally open design ensures that brake pressure can still be built up manually in the event of an electronic failure, allowing the vehicle to be decelerated in any situation.

[0011] The anti-lock braking system may include at least one rotation sensor associated with a front or rear wheel of a vehicle. This allows the rotational speed of the associated wheel to be detected and thus determine whether a wheel is locking. If the rotational speed is zero when the brake force sensor is actuated, the wheel is locked.

[0012] According to one embodiment, a pressure sensor is arranged in the hydraulic path. This allows the brake pressure to be monitored, allowing the hydraulic pump to adjust the brake pressure as needed. This allows the brake pressure to be precisely adjusted.

[0013] The anti-lock braking system, for example, has a control unit configured to control the 2 / 2-way valve and the electric motor. The control unit is specifically configured to close the 2 / 2-way valve before the electric motor, and thus also the hydraulic pump, is activated. Closing the 2 / 2-way valve blocks the hydraulic path between the first hydraulic port and the second hydraulic port, so that brake pressure can no longer be modified manually, but only via the hydraulic pump. Consequently, no manual intervention by the driver is necessary when the anti-lock braking system is active. This makes the anti-lock braking system particularly effective.

[0014] According to one embodiment, a hydraulic line branches off from the hydraulic path to a third hydraulic connection, to which another brake force sensor can be connected. For example, the second hydraulic connection is assigned to a front wheel of a vehicle, and the third hydraulic connection is assigned to a rear wheel. Thus, both the front and rear wheels can be braked during a braking operation.

[0015] The object is further achieved according to the invention by a vehicle, in particular a vehicle propelled by muscle power and / or engine power, with an anti-lock braking system according to the invention, wherein a brake force transmitter is connected to the first hydraulic connection and a brake force receiver is connected to the second hydraulic connection. As already described above, an anti-lock braking system is thus implemented in a vehicle in a particularly simple and cost-effective manner.

[0016] The brake force sensor can comprise a pressure chamber defined by a piston, with a hydraulic line running from the hydraulic pump to the pressure chamber, and with a check valve arranged in the hydraulic line that blocks flow toward the hydraulic pump. Consequently, when the brake force sensor is manually actuated, the hydraulic fluid can only flow from the brake force sensor directly to the brake force receiver via the hydraulic path and the 2 / 2-way valve. At the same time, hydraulic fluid can be drawn in from the hydraulic line running from the hydraulic pump to the pressure chamber.

[0017] For example, a reservoir for hydraulic fluid is arranged in the hydraulic line from which hydraulic fluid can be sucked in.

[0018] The object is further achieved according to the invention by a method for braking a vehicle, in particular a vehicle that can be driven by muscle power and / or engine power, with an anti-lock braking system according to the invention. In a first method step, the brake force sensor is actuated, in particular manually, by a driver of the vehicle with the 2 / 2-way valve open, whereby the hydraulic pressure in the brake force receiver increases and at least one of the two wheels of the vehicle is braked. When the braked wheel locks, the 2 / 2-way valve is closed and the hydraulic pump is operated alternately in delivery mode and in suction mode, so that the hydraulic pump alternately delivers hydraulic fluid into the hydraulic path and sucks it out of the hydraulic path, wherein the change between delivery mode and suction mode occurs at least once per second, in particular at least 10 times per second.Such a procedure prevents the vehicle's wheels from locking, which allows the vehicle to brake particularly safely.

[0019] The 2 / 2-way valve and the hydraulic pump are controlled in particular by the control unit of the anti-lock braking system.

[0020] The change between delivery mode and suction mode is preferably carried out in such a way that the brake pressure is modulated between two defined values.

[0021] It is also conceivable that the anti-lock braking system can generate brake pressure independently of the brake force sensor's activation. For example, it is possible to generate brake pressure to implement anti-theft protection or a rollback lock.

[0022] Further advantages and features of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. In the drawings: - Fig. 1 schematically shows a vehicle according to the invention with an anti-lock braking system according to the invention, and - Fig. 2 schematically shows a vehicle according to the invention according to a further embodiment.

[0023] In Fig. 1 illustrates a vehicle 10 with an anti-lock braking system 12.

[0024] The vehicle 10 is, in particular, a vehicle propelled by muscle power and / or motor power, more specifically a bicycle or an electric bicycle. Alternatively, the vehicle 10 can be a tricycle or an electric tricycle.

[0025] The vehicle 10 comprises a brake force transmitter 14, which is in particular a manually actuated brake lever, and a brake force receiver 16, which is in particular a brake piston.

[0026] The brake force sensor 14 can alternatively also be a pedal of a coaster brake.

[0027] Both the brake force sensor 14 and the brake force receiver 16 comprise a pressure chamber 13 which is delimited by a piston 15.

[0028] The anti-lock braking system 12 has a first hydraulic connection 18 and a second hydraulic connection 20, wherein the first hydraulic connection 18 is connected to the second hydraulic connection 20 via a hydraulic path 22.

[0029] The brake force sensor 14 is connected to the first hydraulic connection 18, and the brake force receiver 16 is connected to the second hydraulic connection 20. The brake force receiver 16 is assigned to the front wheel of the vehicle 10.

[0030] A 2 / 2-way valve 24 is arranged in the hydraulic path 22 between the first hydraulic port 18 and the second hydraulic port 20. The 2 / 2-way valve 24 is a normally open valve.

[0031] In addition, a pressure sensor 26 is arranged in the hydraulic path 22, which detects the fluid pressure prevailing in the hydraulic path 22. Specifically, the pressure sensor 26 is arranged between the 2 / 2-way valve 24 and the second hydraulic connection 20. Thus, the pressure sensor 26 can detect the brake pressure both when the brake force sensor 14 is manually actuated and when the anti-lock braking system 12 is activated.

[0032] The anti-lock braking system 12 further includes a reversibly operable hydraulic pump 28, which is fluidically arranged between the 2 / 2-way valve 24 and the second hydraulic connection 20. In discharge mode, the hydraulic pump delivers hydraulic fluid into the hydraulic path 22 and, in suction mode, draws hydraulic fluid from the hydraulic path 22. The hydraulic pump can be a gerotor pump or a vane pump.

[0033] In the exemplary embodiment, a hydraulic line 30 branches off from the hydraulic path 22, with the hydraulic pump 28 being arranged in the hydraulic line 30.

[0034] The hydraulic pump 28 is driven by an electric motor 31.

[0035] The electric motor 31 is a brushed DC motor. Such motors have a short response time.

[0036] Starting from the hydraulic pump 28, the hydraulic line 30 continues to the pressure chamber 13 of the brake force sensor 14, wherein a check valve 32 blocking in the direction of the hydraulic pump 28 is arranged in the hydraulic line 30 between the first hydraulic connection 18 and the hydraulic pump 28.

[0037] In addition, a reservoir 34 with hydraulic fluid is arranged in the hydraulic line 30 between the check valve 32 and the hydraulic pump 28.

[0038] The anti-lock braking system 12 also includes a rotation sensor 36, which in the exemplary embodiment is assigned to the front wheel of the vehicle 10. Depending on the brake design, it is also conceivable that the rotation sensor 36 is assigned to the rear wheel of the vehicle 10. In this case, the brake force sensor would be assigned to the rear wheel of the vehicle 10.

[0039] In addition, the anti-lock braking system 12 has a control unit 38.

[0040] The control unit 38 is signal-connected to the pressure sensor 26 and to the rotation sensor 36.

[0041] In addition, the control unit 38 is signal-connected to the electric motor 31 and to the 2 / 2-way valve 24. In particular, the control unit 38 is configured to control the electric motor 31 to operate the hydraulic pump 28. Furthermore, the control unit 38 is configured to control the 2 / 2-way valve 24 to open or close it.

[0042] It is conceivable that the system is designed redundantly.

[0043] A method for braking the vehicle 10 is described below.

[0044] If a driver wishes to perform a braking maneuver, he or she will manually actuate the brake force sensor 14. The 2 / 2-way valve 24 is initially open.

[0045] By actuating the brake force sensor 14, the hydraulic pressure in the brake force receiver 16 increases and the front wheel of the vehicle 10 is braked.

[0046] Based on the pressure detected by the pressure sensor 26, the control unit 38 can determine whether the brake force sensor 16 has been actuated.

[0047] By means of the rotation sensor 36, a rotational speed of the braked wheel is also monitored, in particular by the control unit 38.

[0048] As long as the braked wheel does not lock, the 2 / 2-way valve 24 remains open so that the braking process is controlled purely manually.

[0049] If the control unit 38 determines, based on the rotational speed detected by the rotation sensor 36, that the associated wheel is locked, the control unit 38 controls the 2 / 2-way valve 24 to close it. At the same time, the control unit 38 controls the electric motor 31 such that the hydraulic pump 28 is alternately operated in delivery mode and in suction mode, so that the hydraulic pump 28 alternately delivers hydraulic fluid into the hydraulic path 22 and draws it out of the hydraulic path 22.

[0050] In suction mode, the hydraulic fluid is fed into the reservoir 34, and in delivery mode, hydraulic fluid is sucked from the reservoir 34.

[0051] The change between conveying mode and suction mode occurs at least once per second, in particular at least 10 times per second.

[0052] In this way, the brake pressure is modulated, preventing the braked wheel from locking.

[0053] Preferably, the brake pressure is modulated between two defined values.

[0054] The brake pressure is continuously monitored by the control unit 38.

[0055] Fig. 2 shows an alternative embodiment of a vehicle 10 with an anti-lock braking system 12.

[0056] For identical structures with identical functions known from the above embodiment, the same reference numerals are used below and reference is made to the previous explanations, with the differences between the respective embodiments being discussed below in order to avoid repetition.

[0057] In contrast to the previously described embodiment, in the embodiment according to Fig. 2, starting from the hydraulic path 22, a hydraulic line 40 leads to a third hydraulic connection 42, to which a further brake force sensor 44 is connected.

[0058] In the exemplary embodiment, the brake force sensor 16 connected to the second hydraulic connection 18 is assigned to the rear wheel of the vehicle 10, while the brake force sensor 44 connected to the third hydraulic connection 42 is assigned to the front wheel. However, a reverse assignment is also conceivable.

[0059] Accordingly, the anti-lock braking system 12 comprises two rotation sensors 36, one of which is assigned to the front wheel and one to the rear wheel.

[0060] In the embodiment according to Fig. 2, it is therefore possible to brake both the front wheel and the rear wheel by means of the anti-lock braking system 12.

[0061] In a further alternative embodiment, which is not shown for the sake of simplicity, the brake force receiver 44 connected to the third hydraulic connection 42 is assigned its own brake force transmitter, so that the two brake force receivers 16, 44 can each be actuated separately from one another via their own brake force transmitters. For this purpose, for example, an additional hydraulic path separate from the first hydraulic path 22 is provided.

[0062] Furthermore, an additional distribution valve can be provided, which can be controlled by the control unit 38 to control the distribution of the hydraulic fluid between the two brake force sensors 16, 44. In this way, a braking force can be distributed in a defined manner between the two brake force sensors 16, 44.

[0063] In addition, an additional pressure sensor 26 may be present in the hydraulic path between the additional valve and the third hydraulic connection 42.

Claims

[1] Anti-lock braking system (12) for vehicles, in particular for vehicles driven by muscle power and / or motor power, with a first hydraulic connection (18) to which a brake force sensor (14) can be connected, a second hydraulic connection (20) to which a brake force sensor (16) can be connected, wherein the first hydraulic connection (18) is connected to the second hydraulic connection (18) via a hydraulic path (22), a 2 / 2-way valve (24) arranged between the first hydraulic connection (18) and the second hydraulic connection (20) in the hydraulic path (22), and a reversibly operable hydraulic pump (28) which is arranged fluidically between the 2 / 2-way valve (24) and the second hydraulic connection (20), and which delivers hydraulic fluid into the hydraulic path (22) in delivery mode and sucks hydraulic fluid from the hydraulic path (22) in suction mode, wherein the hydraulic pump (28) is driven by an electric motor (31). [2] Anti-lock braking system (12) according to claim 1, characterized by that the 2 / 2-way valve (24) is normally open. [3] Anti-lock braking system (12) according to one of the preceding claims, characterized by that the anti-lock braking system (12) comprises at least one rotation sensor (36) which is associated with a front wheel or a rear wheel of a vehicle (10). [4] Anti-lock braking system (12) according to one of the preceding claims, characterized by that a pressure sensor (26) is arranged in the hydraulic path (22). [5] Anti-lock braking system (12) according to one of the preceding claims, characterized by that the anti-lock braking system (12) has a control unit (38) which is arranged to control the 2 / 2-way valve (24) and the electric motor (31). [6] Anti-lock braking system (12) according to one of the preceding claims, characterized bythat starting from the hydraulic path (22) a hydraulic line (40) branches off to a third hydraulic connection (42) to which a further brake force sensor (44) can be connected. [7] Vehicle (10), in particular a vehicle driven by muscle power and / or motor power, with an anti-lock braking system (12) according to one of the preceding claims, characterized by that a brake force transmitter (14) is connected to the first hydraulic connection (18) and a brake force receiver (16) is connected to the second hydraulic connection (20). [8] Vehicle (10) according to claim 7, characterized by in that the brake force transmitter (14) comprises a pressure chamber (13) which is delimited by a piston (15), wherein a hydraulic line (30) runs from the hydraulic pump (28) to the pressure chamber (13), and wherein a check valve (32) blocking in the direction of the hydraulic pump (28) is arranged in the hydraulic line (30). [9] Method for braking a vehicle (10), in particular a vehicle driven by muscle power and / or motor power, with an anti-lock braking system (12) according to one of claims 1 to 6, comprising the following steps: - the brake force sensor (14) is actuated with the 2 / 2-way valve (24) open, whereby the hydraulic pressure in the brake force sensor (16) increases and at least one of the two wheels of the vehicle (10) is braked, - when the braked wheel locks, the 2 / 2-way valve (24) is closed and the hydraulic pump (28) is operated alternately in delivery mode and in suction mode, so that the hydraulic pump (28) alternately delivers hydraulic fluid into the hydraulic path (22) and sucks it out of the hydraulic path (22), the change between delivery mode and suction mode taking place at least once per second, in particular at least 10 times per second.

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