Patent Description:
Up to now, there are railway vehicles, e.g., box wagons, which are not provided with an own electrical supply. Therefore, if a locomotive without a device for supplying the wagons with electrical energy, such as shunting locomotives, are used or if a wagon tears off from the locomotive or from another wagon, no electrical supply for the wagon is available. In particular, when electro-mechanical brakes are used, electrical energy is required for operating brakes, and, in addition, a wheel slide protection system only works with electrical energy. Therefore, an own energy supply for each railway vehicle is required because, otherwise, the electro-mechanical brakes do not work.

Moreover, due to legal requirements, an amount of energy which is sufficient for stopping a vehicle also in the case of a torn off wagon or wagons of a train part is to be provided in the wagon or in the wagons.

For such an energy supply, batteries, particularly accumulators, are provided and are usually charged from a traction unit. However, for fulfilling the above-mentioned requirement, the batteries have to have sufficient energy capacity and, therefore, they are big and have a high weight and cause increased costs.

Document <CIT> discloses a brake system comprising a controller, a wheel speed sensor system, a generator, and a brake actuator. The controller comprises a brake control unit and the generator generates electrical energy and can charge a battery for supplying the electronic system of a rail-borne wagon.

Therefore, the object underlying the invention is to remedy the above-mentioned disadvantages and problems and to provide a brake system, a railway vehicle, and a method for operating the brake system, enabling a safe operation of a railway vehicle while not excessively increasing manufacturing and operation costs.

The object is achieved by a brake system of a railway vehicle according to claim <NUM>, a railway vehicle according to claim <NUM>, and a method for operating the brake system according to claim <NUM>. Advantageous further developments of the invention are included in the dependent claims.

According to an aspect of the invention, a brake system of a railway vehicle comprises a controller, a wheel speed sensor system, a generator, and a brake actuator. The controller comprises a brake control unit and an energy control unit. The wheel speed sensor system comprises a cogwheel provided on an axle of the railway vehicle, and a wheel speed sensor attached to a non-rotating component of an axle mounting device of the axle in a stationary manner. The generator comprises a permanent magnet attached to the axle and a coil attached to the non-rotating component of the axle mounting device in a stationary manner, and the generator is configured to generate electrical energy and to supply the controller with electrical energy. The energy control unit is configured to control the generator, and the brake control unit is configured to process signals from the wheel speed sensor and to control the brake actuator based on the processed signals.

By this brake system, the generator can generate energy for the controller and the brake actuator can be operated such that the brake actuator, even in case of a malfunction of the external energy supply of the railway vehicle, can actuate a brake of the railway vehicle so that the safety can be ensured even though the railway vehicle is torn off.

Due to an advantageous implementation of the brake system, the controller comprises a wheel slide protection unit, and the wheel slide protection unit is configured to process signals from the wheel speed sensor and to control the brake actuator based on the processed signals.

This implementation enables a more safe operation since also wheel slide is prevented even in case of a malfunction of a regular energy supply of the controller.

According to the invention, the cogwheel is provided in a region of an end of the axle and the permanent magnet is attached to the axle in the region of the end of the axle.

When the cogwheel as well as the permanent magnet are located at the end of the axle, the respective collaborating parts, i.e., the wheel speed sensor and the coil, are also located in this area so that a functional unit is possible with an easy access for assembly and service.

Further, according to the invention, the end of the axle is accommodated in a non-rotating axle box of the railway vehicle, and the wheel speed sensor and the coil are attached to a lid of the axle box.

Thereby, already provided components of a carriage can be used for accommodating and protecting the parts of the functional unit so that there is no need to provide further components for attaching and protecting these parts which safes costs and installation space.

In a further advantageous implementation of the brake system, the brake system comprises a cable harness including at least two cables configured to transmit control signals from the controller to the generator, one cable configured to transmit energy generated by the generator, and one cable configured to connect the wheel speed sensor system and the controller.

When using the cable harness for these cables, the assembly work is reduced and the wiring can be done such that the cables can easily be fixed and protected from damage.

According to a further advantageous implementation of the brake system, it further comprises an energy storage device configured to store the electrical energy generated by the generator, and the energy control unit is configured to process data from the energy storage device and to control the generator based on the processed data.

This implementation enables the operation of the brake system also when the railway vehicle is separated from, e.g., a traction vehicle. Further, in particular, by the energy control unit, the available amount of energy in the storage device can be kept on a required level.

In a further advantageous implementation of the brake system, the generator is configured to supply another electric consumer of the railway vehicle with energy.

Such a brake system enables the operation of the other electric consumer, such as electric doors, when the railway vehicle is separated from other parts of the train or when the locomotive is not provided with an energy supply system for the railway vehicle.

According to a further aspect of the invention, a railway vehicle comprises a brake system according to the invention so that, even in case of a malfunction of the external energy supply of the railway vehicle, a brake of the railway vehicle can be operated so that the safety can be ensured even though the railway vehicle is torn off.

According to another aspect of the invention, a method for controlling a brake system according to the invention comprises the steps: monitoring operating parameters of the railway vehicle by the energy control unit and activating the generator by the energy control unit for generating electrical energy based on the operating parameters.

Based on results of the monitoring of the operating parameters, e.g., the results of a motion or of a speed of the railway vehicle, the generator can be activated and it can be controlled such as to provide a currently sufficient amount of energy. Thus, the operation of the railway vehicle with the brake system becomes safe.

In an advantageous implementation of the method, one of the operating parameters is a supply voltage of the controller automatically detected by a voltmeter and processed by the energy control unit, and the generator is activated by the energy control unit when the supply voltage falls below a predetermined threshold.

In this manner, an energy supply having an appropriated voltage can be provided and a failure of a main supply can be detected in order to ensure safe operation of the brake system even in case of a malfunction of the main supply.

According to the invention, one of the operating parameters is a current energy capacity of the energy storage device detected by a voltmeter and processed by the energy control unit, and the generator is activated by the energy control unit when the current energy capacity falls below a predetermined threshold.

By this function, a sufficient energy supply for braking actions can be provided.

Further, according to the invention, the predetermined threshold of the current energy capacity is determined based on an estimated energy consumption for braking the railway vehicle from a current speed to a standstill.

Thereby, the subsequent safe stopping can be ensured, e.g., in case of a torn off of the railway vehicle.

Due to a further advantageous implementation of the method, one of the operating parameters is an actuation signal for the brake actuator, and the generator is activated when the brake actuator is actuated.

This function enables an economic provision of energy since the generator does not generate energy during travelling of the railway vehicle with a constant speed or during acceleration but merely when the railway vehicle is decelerated. Thereby, the generator can also assist the brakes such that also the wear of the brakes is reduced.

In yet a further advantageous implementation of the method, the generator supplies energy to another electric consumer of the railway baking.

This implementation enables an operation of the other electric consumer although no energy supply from, e.g., a locomotive, is provided for this consumer in order to save electric lines.

Subsequently, the invention is elucidated by means of embodiment referring to the attached drawings.

<FIG> shows a block diagram of a brake system <NUM> of a railway vehicle <NUM>.

The brake system <NUM> comprises a controller <NUM> which, in turn, comprises a brake control unit <NUM>, an energy control unit <NUM>, and a wheel slide protection unit <NUM>. In an alternative embodiment, the wheel slide protection unit <NUM> is omitted.

The brake system <NUM> further comprises four wheel speed sensor systems <NUM> respectively providing operating parameters whether the railway vehicle <NUM> moves or is in standstill and, also, operating parameters about the speed of the railway vehicle <NUM>. In alternative embodiments, another number of wheel speed sensor systems <NUM>, nevertheless, at least one wheel speed sensor system <NUM>, is provided.

Furthermore, the brake system <NUM> comprises a generator <NUM>. The generator <NUM> is configured to supply the controller <NUM> with electrical energy. In alternative embodiments, another quantity of generators <NUM> is provided and/or the generator <NUM> also supplies electrical energy to at least one other electrical consumer of the railway vehicle <NUM>.

Moreover, the brake system <NUM> comprises four electro-mechanical brake actuators <NUM>. In alternative embodiments, another quantity of the electromechanical brake actuators <NUM>, nevertheless, at least one brake actuator <NUM>, is provided. The brake actuators <NUM> are actuated by actuation signals from the brake control unit <NUM> as indicated by the arrows "FB1" to "FB4".

Finally, the brake system <NUM> comprises an accumulator as an energy storage device <NUM>, nevertheless, in alternative embodiments, another quantity of energy storage devices <NUM> is provided or the energy storage device <NUM> is not provided but it is omitted. The energy storage device <NUM> is configured to store the electrical energy generated by the generator <NUM> and the energy control unit <NUM> is configured to process data being operating parameters from the energy storage device <NUM> and to control the generator <NUM> based on the processed data. Alternatively, the energy control unit <NUM> does not control the generator <NUM> based on the processed data from the energy storage device but based on other operating parameters.

The railway vehicle <NUM> is further provided with a power line <NUM> as a main energy supply which supplies the controller <NUM> and the energy storage device <NUM> with electrical energy. In case of a proper function of a main energy supply, the energy storage device <NUM> stores the energy supplied by the power line <NUM>.

The wheel speed sensor systems <NUM> provide operating parameters concerning the wheel speed and, therefore, concerning the speed of the railway vehicle <NUM>, as indicated by the arrows "v1" to "v4".

The energy storage device <NUM> provides operating parameters "cec" concerning its current energy capacity and the current energy capacity of the energy storage device <NUM> is monitored by the energy control unit <NUM>.

Furthermore, the energy control unit <NUM> activates and deactivates the generator <NUM> by a switching signal "sw" based on the operating parameters.

<FIG> shows an axle <NUM> of the railway vehicle <NUM>. In particular, <FIG> shows an end <NUM> of the axle <NUM>.

In a region of the end <NUM>, the axle <NUM> is provided with a cogwheel <NUM>. Furthermore, also in the region of the end <NUM> of the axle <NUM>, permanent magnets <NUM> are attached to the axle <NUM>. The permanent magnets <NUM> are attached to the axle <NUM> directly. In alternative embodiments, the permanent magnets <NUM> are attached to the axle <NUM> through a separate component comprising the cogwheel <NUM>, in particular, the permanent magnets <NUM> are attached by fastening members extending through the component comprising the cogwheel <NUM> to fasten the permanent magnets <NUM> and the component comprising the cogwheel to the axle <NUM>.

According to the present invention, the railway vehicle <NUM> is provided with a non-rotating axle box <NUM> which accommodates the end <NUM> of the axle <NUM>. The axle box <NUM> accommodates bearings which are configured to support the axle <NUM> in a rotating manner with respect to the axle box <NUM>. Further, the axle box <NUM> is attached to the railway vehicle <NUM>, in particular, my means of springs, so as to transmit the weight of the railway vehicle <NUM> to the axle <NUM> and, therefore, to wheels of the railway vehicle <NUM>. Furthermore, the axle box <NUM> is closed by a lid <NUM> to which a wheel speed sensor <NUM> and coils <NUM> are attached. For the sake of visibility, the lid <NUM> is removed from the position where it closes the axle box <NUM> and it is located beside the axle box <NUM>. In alternative embodiments, at least one of the wheel speed sensor <NUM> and the coils <NUM> is not attached to the lid <NUM> but to another component of the axle box <NUM> or to another non-rotating part of an axle mounting device in a stationary manner with respect to the axle <NUM>.

The cogwheel <NUM> and the wheel speed sensor <NUM> form the wheel speed sensor system <NUM>. The permanent magnets <NUM> and the coils <NUM> form the generator <NUM> which generates electrical energy when the permanent magnets <NUM> pass along the coils <NUM>. The cogwheel <NUM>, the wheel speed sensor <NUM>, the permanent magnets <NUM> and the coils <NUM> are components of the brake system <NUM> of the railway vehicle <NUM>.

In alternative embodiments, not according to the claimed invention, the cogwheel <NUM> and the permanent magnets <NUM> are not provided in the region of the end <NUM> of the axle <NUM> but, also as separate components connected to the axle <NUM>, at other suitable locations on the axle <NUM>. Furthermore, alternatively, the wheel speed sensor <NUM> and the coils <NUM> are not provided in the shown quantity, but a suitable number of the wheel speed sensor <NUM> and the coils <NUM>, nevertheless, at least one wheel speed sensor <NUM> and at least one coil <NUM>, is provided. Also, in alternative embodiments, the quantity of the permanent magnets <NUM> does not correspond to the shown permanent magnets <NUM> but at least one permanent magnet <NUM> is provided.

Furthermore, the brake system <NUM> comprises a cable harness <NUM>. The cable harness <NUM> includes a cable configured to transmit control signals from the controller <NUM> to the generator <NUM>, a cable configured to transmit energy generated by the generator <NUM>, and a cable configured to connect the wheel speed sensor system <NUM> and the controller <NUM>, in particular, the wheel slide protection unit <NUM>. Alternatively, at least two of these cables or further cables are included in the cable harness <NUM>.

As to be seen by the arrows FB1 to FB4 in <FIG>, the brake control unit <NUM> is configured to control the brake actuators <NUM>, by the arrow sw, the energy control unit <NUM> is configured to control the generator <NUM>, and the wheel slide protection unit <NUM> is configured to receive and to process signals, in particular, the operating parameters "wheel speed" v1 to v4 from the wheel speed sensors <NUM> of the wheel speed sensor systems <NUM> and to also control the brake actuators <NUM> based on the processed signals via the brake control unit <NUM> (FB1 to FB4).

In operation, a method for controlling the brake system <NUM> according to the invention is executed. The method comprises the steps: monitoring operating parameters of the railway vehicle <NUM> by the energy control unit <NUM>, and activating the generator <NUM> for generating electrical energy by the energy control unit <NUM> based on the operating parameters.

One of the monitored operating parameter is a supply voltage of the controller <NUM> which is automatically detected by a voltmeter (not shown) and processed by the energy control unit <NUM>. If the supply voltage of the controller <NUM> and, therefore, of the brake actuators <NUM>, is above a predetermined threshold, the supply with electrical energy from, e.g., a locomotive, is provided, the generator <NUM> is not activated.

However, if, due to, e.g., torn off of the railway vehicle <NUM> or a failure of the energy supply from the locomotive, the supply voltage detected by the voltmeter falls below the predetermined threshold, the generator <NUM> is activated by the energy control unit <NUM>. Therefore, then, the controller <NUM> and the brake actuators <NUM> are supplied by the electrical energy from the generator <NUM>, in particular, by the electrical energy generated by the generator <NUM> and stored in the energy storage device <NUM>.

Another monitored operating parameter is a current energy capacity of the energy storage device <NUM> also detected by the voltmeter. If the current energy capacity of the energy storage device <NUM> falls below a predetermined threshold, the generator <NUM> is activated for charging the energy storage device <NUM>. The predetermined threshold is determined based on an estimated energy consumption for braking the railway vehicle <NUM> from a current speed to a standstill. Alternatively, the threshold can be determined based on another possible maneuver, for example several brakings or a braking while the wheel slide protection unit <NUM> is in operation.

Furthermore, one of the operating parameters is an activation signal for the brake actuators <NUM>, and the generator <NUM> is activated when the brake actuators <NUM> are actuated. In particular, the generator <NUM> is activated when the brake actuators <NUM> are actuated and the supply voltage falls below the predetermined threshold. Alternatively, the generator <NUM> is activated during braking independently from the level of the supply voltage so that the current energy capacity of the energy storage device <NUM> is always maintained on a sufficient level. In further alternative embodiments, the operating parameters are considered for the decision if the generator <NUM> is operated in a suitable combination.

If necessary, the generator <NUM> also supplies another electric consumer (not shown) with electrical energy such that, e.g., in case of the torn off railway vehicle <NUM>, also the other electric consumer can be operated.

Claim 1:
A brake system (<NUM>) of a railway vehicle (<NUM>), the brake system (<NUM>) comprising
a controller (<NUM>),
a wheel speed sensor system (<NUM>),
a generator (<NUM>), and
a brake actuator (<NUM>),
wherein
the controller (<NUM>) comprises
a brake control unit (<NUM>), and
the generator (<NUM>) is configured to generate electrical energy and to supply the controller (<NUM>) with electrical energy,
characterized in that
the controller further comprises an energy control unit (<NUM>),
the wheel speed sensor system (<NUM>) comprises
a cogwheel (<NUM>) provided on an axle (<NUM>) of the railway vehicle (<NUM>), and
a wheel speed sensor (<NUM>) attached to a non-rotating component of an axle mounting device of the axle (<NUM>) in a stationary manner, and
the generator (<NUM>) comprises
a permanent magnet (<NUM>) attached to the axle (<NUM>), and
a coil (<NUM>) attached to the non-rotating component of the axle mounting device in a stationary manner,
wherein
the energy control unit (<NUM>) is configured to control the generator (<NUM>),
the brake control unit (<NUM>) is configured to process signals from the wheel speed sensor (<NUM>) and to control the brake actuator (<NUM>) based on the processed signals,
the cogwheel (<NUM>) is provided in the region of an end of the axle (<NUM>) and the permanent magnet (<NUM>) is attached to the axle (<NUM>) in the region of the end (<NUM>) of the axle (<NUM>),
the end (<NUM>) of the axle (<NUM>) is accommodated in a non-rotating axle box (<NUM>) of the railway vehicle (<NUM>), and
the wheel speed sensor (<NUM>) and the coil (<NUM>) are attached to a lid (<NUM>) of the axle box (<NUM>).