Brake control device and brake control method

Abstract

A brake control device (1) according to the present invention controls mechanical brake devices (1, 2, 3, 4) including a power source (11), a pressing mechanism, a biasing mechanism, and a switching mechanism (14) that is in either an allowable state in which the biasing mechanism is allowed to bias a friction material toward a rotating body or a restricted state in which the biasing mechanism is restricted from biasing the friction material toward the rotating body. When a biasing mechanism operation command is cancelled, a mechanism control unit (33) switches the switching mechanism (14) from the allowable state to the restricted state for a relevant device that is at least one mechanical brake device (1, 2, 3, 4) from among a plurality of the mechanical brake devices (1, 2, 3, 4), and then switches the switching mechanism (14) of another mechanical brake device (1, 2, 3, 4) from among the plurality of mechanical brake devices (1, 2, 3, 4) from the allowable state to the restricted state.

Description

Brake control device and brake control method

[0001] The present disclosure relates to a brake control device and a brake control method.

[0002] A moving body, for example, a railway vehicle, is equipped with a mechanical brake device that generates a braking force by pressing a friction material against a rotating body that rotates during traveling. Mechanical brake devices include: pneumatic brake devices that press a friction material against a rotating body by a piston that linearly moves according to the pressure of air in a brake cylinder; electric brake devices that linearly move the output shaft of a rotary-linear motion conversion mechanism by the rotation of a motor, thereby pressing the friction material attached to the output shaft against the rotating body; and spring-type brake devices that press the friction material against the rotating body by the force of a spring.

[0003] An example of this type of mechanical brake device is disclosed in Patent Document 1. The brake caliper device disclosed in Patent Document 1 includes an electric cylinder that actuates a service brake by rotation of an electric motor, and a spring cylinder that functions as a safety brake. During service braking, a mechanical braking force is generated when a brake pad is pressed against a disc in accordance with the rotation of the electric motor. During safety braking, a rod pressed by the spring of the spring cylinder rotates a rotating lever, whereby both surfaces of the disc are pressed by brake pads to generate a mechanical braking force.

[0004] Japanese Unexamined Patent Application Publication No. 2024-016823

[0005] In the brake caliper device disclosed in Patent Document 1, when releasing the safety brake, the electric motor of the electric cylinder rotates in the reverse direction, whereby the spring of the spring cylinder is pushed back. When the springs of the spring cylinders included in the brake caliper devices provided for each wheel are pushed back all at once and the braking force decreases, it may be difficult to suppress rolling of a stopped moving body, specifically, a railway vehicle stopped at a station on a slope, or a railway vehicle stopped at a station with passengers on board.

[0006] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a brake control device and a brake control method capable of suppressing rolling of a moving body.

[0007] To achieve the above objective, the brake control device according to the present disclosure is a brake control device that controls a plurality of mechanical brake devices, each provided on a moving body for each rotating body that rotates when the moving body is in motion, and which generate a mechanical braking force, the control device comprising: a power source that rotates driven by supplied electricity; a pressing mechanism that generates a mechanical braking force by pressing a friction material against a rotating body in accordance with the rotational force transmitted from the power source; a biasing mechanism that generates a mechanical braking force by biasing the friction material toward the rotating body; and a switching mechanism that is in either an allowable state that allows the biasing mechanism to bias the friction material toward the rotating body or a restricting state that restricts the biasing mechanism from biasing the friction material toward the rotating body, the brake control device comprising: a mechanism control unit; a target brake force determination unit; and a drive unit. When the mechanism control unit receives a biasing mechanism operation command that instructs the operation of the biasing mechanism, it sets the switching mechanism to the allowable state, and when it has not received a biasing mechanism operation command, it sets the switching mechanism to the restricting state. The target brake force determination unit receives a brake command for the moving body and determines a target brake force, which is the brake force required to obtain the target deceleration indicated by the brake command. When the switching mechanism is in the restricted state, the drive unit determines a first target torque, which is a target value for the torque of the power source, from the target braking force, and drives the power source according to the first target torque. When the biasing mechanism operation command is released, the mechanism control unit switches the switching mechanism of the target device, which is at least one of the multiple mechanical brake devices, from the permitted state to the restricted state, and then switches the switching mechanisms of the other mechanical brake devices from the permitted state to the restricted state.

[0008] The brake control device according to this disclosure switches the switching mechanism of a target device, which is at least one of a plurality of mechanical brake devices, from an allowable state, which allows the biasing mechanism to bias the friction material toward the rotating body, to a restricting state, which restricts the biasing mechanism from biasing the friction material toward the rotating body. Subsequently, the brake control device switches the switching mechanism of the other mechanical brake devices from the allowable state to the restricting state. As a result, it becomes possible to suppress the rolling of the moving body.

[0009] A diagram showing an example of a railway vehicle equipped with the brake control device according to Embodiment 1. A diagram showing an example of mounting the mechanical brake device in Embodiment 1 on a bogie. A diagram showing the configuration of the mechanical brake device in Embodiment 1. A diagram showing a modified configuration of the mechanical brake device in Embodiment 1. A diagram showing a specific example of the configuration of the mechanical brake device in Embodiment 1. A diagram showing an example of the operation of the mechanical brake device in Embodiment 1. A block diagram showing the configuration of the brake control system according to Embodiment 1. A block diagram showing a modified configuration of the brake control system according to Embodiment 1. A diagram showing an example of mounting the brake control system according to Embodiment 1 on a railway vehicle. A block diagram showing the hardware configuration of the brake control device according to Embodiment 1. A flowchart showing an example of the operation of the brake control process performed by the brake control device according to Embodiment 1. A diagram showing another example of the operation of the mechanical brake device in Embodiment 1. A flowchart showing an example of the operation of the biasing mechanism stop process performed by the device. A figure showing another example of the operation of the mechanical brake device in Embodiment 1. A figure showing a modified example of the mounting of the brake control system according to Embodiment 1 to a railway vehicle. A figure showing a specific example of the mechanical brake device in Embodiment 2. A block diagram showing the configuration of the brake control system according to Embodiment 2. A figure showing an example of the operation of the mechanical brake device in Embodiment 2. A figure showing another example of the operation of the mechanical brake device in Embodiment 2. A figure showing another example of the operation of the mechanical brake device in Embodiment 2. A figure showing another example of the operation of the mechanical brake device in Embodiment 2. A figure showing another example of the operation of the mechanical brake device in Embodiment 2. A figure showing another example of the operation of the mechanical brake device in Embodiment 2. A figure showing another example of the operation of the mechanical brake device in Embodiment 2. A block diagram showing a modified example of the hardware configuration of the brake control device according to Embodiment 2.

[0010] The brake control device and brake control method according to the embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

[0011] (Embodiment 1) Using a mechanical brake device mounted on a railway vehicle, which is an example of a moving body, that is decelerated by mechanical braking force, and provided for each wheel, which is an example of a rotating body, as an example, a brake control device and a mechanical brake device controlled by the brake control device according to Embodiment 1 will be described. The railway vehicle 200 shown in Figure 1 comprises one or more vehicles, in the example of Figure 1, two vehicles 201 and 202, and four bogies 70 that support the vehicles 201 and 202. The bogies 70 that support vehicle 201 are distinguished as bogies 70a and 70b, and the bogies 70 that support vehicle 202 are distinguished as bogies 70c and 70d.

[0012] In Figure 1, the X-axis direction represents the width direction of vehicles 201 and 202. The Y-axis direction represents the direction of travel of the railway vehicle 200. The Z-axis is perpendicular to both the X-axis and the Y-axis. When the railway vehicle 200 is positioned horizontally, the Z-axis direction represents the vertical direction.

[0013] As shown in Figure 2, which is a view of the bogie 70 from above in the vertical direction, the bogie 70 comprises wheels 71, 72, 73, and 74, an axle 75 to which wheels 71 and 72 are attached at both ends, and an axle 76 to which wheels 73 and 74 are attached at both ends. The bogie 70 is fitted with electric motors 77 and 78 that rotate by receiving power from a power conversion device (not shown), gear units 81 and 82 that transmit rotational force transmitted from the electric motors 77 and 78 via couplings 79 and 80 to the axles 75 and 76, and mechanical brake units 1, 2, 3, and 4 that generate mechanical braking force.

[0014] The mechanical brake devices 1, 2, 3, and 4 are mounted on the railway vehicle 200 and are provided in correspondence with the wheels 71, 72, 73, and 74 of each bogie 70. Since the configurations of the mechanical brake devices 1, 2, 3, and 4 are the same, mechanical brake device 1 will be described first.

[0015] The mechanical brake device 1 shown in Figure 3 comprises a power source 11 that rotates when driven by supplied electricity, a pressing mechanism 12 that presses a friction material 50 against a wheel 71 in accordance with the rotational force transmitted from the power source 11, a biasing mechanism 13 that biases the friction material 50 toward the wheel 71, and a switching mechanism 14 that is in either an allowable state where the biasing mechanism 13 is allowed to bias the friction material 50 toward the wheel 71, or a restricting state where the biasing mechanism 13 is restricted from biasing the friction material 50 toward the wheel 71. Note that the biasing mechanism 13 biasing the friction material 50 toward the wheel 71 is not limited to the biasing mechanism 13 directly biasing the friction material 50 toward the wheel 71, but also includes the biasing mechanism 13 indirectly biasing the friction material 50 toward the wheel 71.

[0016] An example of a mechanical brake device 1 is shown in Figure 4. The pressing mechanism 12 includes, as an example, a rotation-to-linear motion conversion mechanism 15 that presses the power-boosting mechanism 16 in accordance with the rotational force transmitted from the power source 11, and a power-boosting mechanism 16 that generates a mechanical braking force by pressing the friction material 50 against the wheel 71 in accordance with the applied force. The rotation-to-linear motion conversion mechanism 15 includes, as an example shown in Figure 5, a gear 18 that transmits the rotational force of the power source 11 to a ball screw 19, and a ball screw 19 that performs linear motion in accordance with the rotational force transmitted from the power source 11 via the gear 18.

[0017] Preferably, the mechanical brake device 1 further comprises a pressing member 17 attached to one end of the biasing mechanism 13 and pressed against the power assist mechanism 16, a housing 24 housing the biasing mechanism 13, the switching mechanism 14, and the pressing member 17, and a sensor 25 that measures at least the rotational speed and rotational position of the power source 11.

[0018] The power source 11 is, for example, a motor that rotates when power is supplied, specifically an AC motor. The power source 11 rotates when power is supplied from an external source and transmits the rotational force to the pressing mechanism 12. In detail, the power source 11 is driven by three-phase AC power supplied from an external source and rotates the drive shaft 11a. Preferably, the drive shaft 11a of the power source 11 is connected to the pressing mechanism 12 via a one-way clutch (not shown). This ensures that the rotational force is transmitted only in the direction from the power source 11 to the pressing mechanism 12.

[0019] The gear 18 is fitted onto the drive shaft 11a of the power source 11. The ball screw 19 has a nut 19a that rotates in conjunction with the rotation of the gear 18, an output shaft 19b attached to the nut 19a that performs linear motion in accordance with the rotation of the nut 19a, and a ball (not shown) that rolls between the nut 19a and the output shaft 19b. The outer surface of the nut 19a is gear-machined, and the nut 19a meshes with the gear 18. One end of the output shaft 19b is attached to the power assist mechanism 16. When the drive shaft 11a of the power source 11 and the gear 18 rotate together, the nut 19a that meshes with the gear 18 rotates, and the ball rolls between the nut 19a and the output shaft 19b. As a result, the output shaft 19b performs linear motion. As the output shaft 19b performs linear motion toward the power assist mechanism 16, the output shaft 19b presses against the power assist mechanism 16.

[0020] The power-amplifying mechanism 16 is a lever mechanism that, when one end is pressed by the rotation-to-linear motion conversion mechanism 15, presses the friction material 50 against the wheel 71 in the opposite direction to the pressing direction by the rotation-to-linear motion conversion mechanism 15. In detail, the power-amplifying mechanism 16 has an arm 16c that can rotate around a fulcrum 16b. A ball screw 19 is attached to one end of the arm 16c. The position where the ball screw 19 is attached becomes the point of force application 16a of the power-amplifying mechanism 16. The other end of the arm 16c, in other words, the end of the arm 16c opposite to the point of force application 16a with respect to the fulcrum 16b, is attached to the friction material 50 by a mounting member 20. The position where the friction material 50 is attached by the mounting member 20 becomes the point of application 16d. The power-amplifying mechanism 16 amplifies the force applied to the point of force application 16a by the ball screw 19 and outputs the amplified force from the point of application 16d, thereby pressing the friction material 50 against the wheel 71.

[0021] The biasing mechanism 13 is, for example, a coil spring, with one end attached to the pressing member 17 and the other end attached to the housing 24 that houses the switching mechanism 14. In the example shown in Figure 5, the biasing direction of the biasing mechanism 13 is opposite to the direction in which the rotation-to-linear motion conversion mechanism 15 presses the power-amplifying mechanism 16. The biasing mechanism 13 presses the power-amplifying mechanism 16 by biasing the pressing member 17 toward the power-amplifying mechanism 16.

[0022] The pressing member 17 is, for example, a plate-shaped member, which is pressed against the power assist mechanism 16 by the biasing mechanism 13. The pressing member 17 is pressed against the power assist mechanism 16 at a position that allows the power assist mechanism 16 to be activated and press the friction material 50 against the wheel 71. In the example of Figure 5, the pressing member 17 is pressed against the power assist mechanism 16 at a position near the point of application 16d, but further from the fulcrum 16b than the point of application 16d.

[0023] The switching mechanism 14 is in either an allowable state, which allows the biasing mechanism 13 to press against the power-amplifying mechanism 16, or a restricting state, which restricts the biasing mechanism 13 from pressing against the power-amplifying mechanism 16. For example, the switching mechanism 14 switches between the allowable state and the restricting state depending on the energized state. In other words, the switching mechanism 14 allows or restricts the biasing mechanism 13 from pressing against the power-amplifying mechanism 16 depending on the energized state. The switching mechanism 14 shown in Figure 5 is, as an example, an electromagnetic clutch having a rotor 21 with a coil 23 and an armature 22 to which a pressing member 17 is attached. The switching mechanism 14 is, as an example, a tooth clutch, in which teeth are formed on the surface of the rotor 21 facing the armature 22 and on the surface of the armature 22 facing the rotor 21. For example, the switching mechanism 14 may have a linear motion mechanism, such as a ball spline or ball screw, attached to the armature 22 and inserted into the rotor 21, in order to enable the armature 22 to perform smooth linear motion.

[0024] The housing 24 is attached to the trolley 70. The shape of the housing 24 is any shape that can accommodate the biasing mechanism 13, the switching mechanism 14, and the pressing member 17, and has an open end.

[0025] The sensor 25 is a pulse detection sensor that measures the rotational speed, rotational position, rotational amount, etc. of the power source 11 based on a pulse signal output by an encoder, for example, located near the drive shaft 11a.

[0026] The friction material 50 is a brake shoe. When the friction material 50 is pressed against a wheel 71, which is an example of a rotating body, a mechanical braking force is generated.

[0027] In the mechanical brake device 1 having the above configuration, when power is supplied to the coil 23, in other words, when the coil 23 is energized, the armature 22 is attracted to the rotor 21, as shown in Figure 5. Because the rotor 21 and the armature 22 are meshed with each other, the rotation and movement of the armature 22 are restricted, and the movement of the pressing member 17 attached to the armature 22 and the biasing mechanism 13 attached to the pressing member 17 are restricted. As a result, the biasing mechanism 13 biases the pressing member 17 toward the power assist mechanism 16, thereby limiting the pressing of the power assist mechanism 16. Note that when the armature 22 is attracted to the rotor 21, the length of the biasing mechanism 13 in the biasing direction is shorter than its natural length.

[0028] When no power is supplied to the coil 23, in other words, when the coil 23 is demagnetized, the rotor 21 and the armature 22 are positioned apart from each other, as shown in Figure 6. This allows the movement of the pressing member 17 attached to the armature 22 and the biasing mechanism 13 attached to the pressing member 17. Also, because the coil 23 is demagnetized, the spring of the biasing mechanism 13, whose movement was restricted by the armature 22 being attracted to the rotor 21, is released, and the length of the spring returns to its natural length. In other words, the biasing mechanism 13 is allowed to press the power-amplifying mechanism 16 by biasing the pressing member 17 against the power-amplifying mechanism 16. When the biasing mechanism 13 presses the other end of the power-amplifying mechanism 16, the friction material 50 is pressed against the wheel 71, generating a mechanical braking force.

[0029] Figure 7 shows a brake control system 100 comprising a mechanical brake device 1-4 having the above configuration and a brake control device 30 that controls the mechanical brake device 1-4. In Figure 7, only the components related to electrical control of the mechanical brake device 1-4 are shown.

[0030] The brake control device 30 includes a target brake force determination unit 31 that determines a target brake force, which is a target value of brake force, from the target deceleration indicated by the brake command included in the driving command S1 acquired from the master controller 41; a drive unit 32 that drives the power source 11 according to a first target torque based on the target brake force; and a mechanism control unit 33 that switches between an allowable state and a limiting state of the switching mechanism 14. The brake control device 30 may have a common drive unit 32 for the mechanical brake devices 1-4, or it may have the same number of drive units 32 as the mechanical brake devices 1-4. The drive unit 32 supplies power to the power source 11 of the corresponding mechanical brake device 1-4.

[0031] The drive unit 32 converts the power supplied from the power supply device 42 into power to be supplied to the power source 11, and drives the power source 11 by supplying the converted power to the power source 11. As an example, as shown in Figure 8, the drive unit 32 includes a speed control unit 34 that determines a first target torque from the target braking force, a torque control unit 35 that generates a PWM (Pulse Width Modulation) signal and outputs a PWM signal, and a power conversion circuit 36 ​​that converts the power supplied from the power supply device 42 into power to be supplied to the power source 11 of the mechanical brake device 1.

[0032] The master controller 41 outputs an operation command S1 in response to the operator's input. The operation command S1 includes one of the following: a power command instructing the railway vehicle 200 to accelerate, a brake command instructing the railway vehicle 200 to decelerate, and a coasting command instructing the railway vehicle 200 to coast. The power command indicates a target acceleration, which is the target value of the acceleration of the railway vehicle 200. The target acceleration corresponds to the notch in response to the operator's input.

[0033] A brake command includes one of the following: a service brake command, an emergency brake command, or a biasing mechanism operation command. The service brake command indicates a target deceleration, which is a target value for the degree of deceleration of the railway vehicle 200. The target deceleration corresponds to the notch according to the operator's operation. The emergency brake command indicates an emergency target deceleration, which has an absolute value greater than the target deceleration that can be indicated by the service brake command. The biasing mechanism operation command is a command that instructs the operation of the biasing mechanism 13, and is either a safety brake command to decelerate the railway vehicle 200 in the event of a malfunction of the service brake, or a parking brake command to prevent the stationary railway vehicle 200 from rolling when the service brake is functioning normally. When a biasing mechanism operation command is input, the brake control device 30 sets the switching mechanism 14 of the mechanical brake device 1-4 to an allowable state. As a result, the biasing mechanism 13 presses against the power assist mechanism 16, pressing the friction material 50 against the wheels 71-74 and generating a mechanical braking force.

[0034] The power supply unit 42 converts the power supplied from a current collector (not shown) into power for supply to the power conversion circuit 36 ​​and the switching mechanism 14 of the mechanical brake device 1-4, and outputs the converted power to the power conversion circuit 36 ​​and the switching mechanism 14 of the mechanical brake device 1-4. As an example, the power supply unit 42 has an inverter that receives DC power from a current collector that acquires power from a substation via a power supply line and converts the DC power into AC power, and a rectifier circuit that rectifies the AC power into DC power. The power supply unit 42 may be a common power supply unit for the mechanical brake devices 1-4, or it may be a power supply unit provided in accordance with each of the mechanical brake devices 1-4.

[0035] Relay 43 is switched on and off by the mechanism control unit 33. By turning relay 43 on, the mechanism control unit 33 allows power to be supplied from the power supply unit 42 to the switching mechanism 14, and by turning relay 43 off, it stops the power supply from the power supply unit 42 to the switching mechanism 14. Relay 43 may be a relay common to at least some of the mechanical brake devices 1-4, or it may be a relay provided according to each of the mechanical brake devices 1-4.

[0036] The brake control system 100 having the above configuration is mounted on vehicles 201 and 202, as shown in Figure 9. A brake control device 30 is provided in each of the vehicles 201 and 202. The brake control device 30 provided in vehicle 201 is referred to as brake control device 30a, and the brake control device 30 provided in vehicle 202 is referred to as brake control device 30b.

[0037] As an example, power supply units 42 are provided in both vehicles 201 and 202. The power supply unit 42 provided in vehicle 201 is designated as power supply unit 42a, and the power supply unit 42 provided in vehicle 202 is designated as power supply unit 42b. The relay 43 provided in vehicle 201 is designated as relay 43a, and the relay 43 provided in vehicle 202 is designated as relay 43b.

[0038] As shown in Figure 1, each of the trolleys 70a, 70b, 70c, and 70d is equipped with a mechanical brake device 1-4, as shown in Figure 2. In Figure 9, the mechanical brake devices 1, 2, 3, and 4 installed on trolley 70a are shown as mechanical brake devices 1a, 2a, 3a, and 4a. Similarly, the mechanical brake devices 1, 2, 3, and 4 installed on trolley 70b are shown as mechanical brake devices 1b, 2b, 3b, and 4b. Similarly, the mechanical brake devices 1, 2, 3, and 4 installed on trolley 70c are shown as mechanical brake devices 1c, 2c, 3c, and 4c. Similarly, the mechanical brake devices 1, 2, 3, and 4 installed on trolley 70d are shown as mechanical brake devices 1d, 2d, 3d, and 4d.

[0039] The brake control device 30a installed on vehicle 201 controls the mechanical brake devices 1a, 2a, 3a, 4a, 1b, 2b, 3b, and 4b installed on bogies 70a and 70b corresponding to vehicle 201. Similarly, the brake control device 30b installed on vehicle 202 controls the mechanical brake devices 1c, 2c, 3c, 4c, 1d, 2d, 3d, and 4d installed on bogies 70c and 70d corresponding to vehicle 202. The brake control devices 30a and 30b control the mechanical brake devices 1a-1d, 2a-2d, 3a-3d, and 4a-4d in accordance with the driving command S1 obtained from a common master controller 41.

[0040] Figure 10 shows the hardware configuration of the brake control device 30 having the above configuration. The brake control device 30 comprises a processor 91, a memory 92, and an interface 93. The processor 91, the memory 92, and the interface 93 are connected to each other by a bus 90. The processor 91 includes any electronic circuit including transistors and is considered a circuit or processor circuit.

[0041] The functions of the brake control device 30 are realized by software, firmware (software embedded in electronic equipment), or a combination of software and firmware. The software is written as a program and stored in memory 92. The processor 91 reads and executes the program stored in memory 92, thereby realizing the functions of each of the above-mentioned parts. In other words, memory 92 stores a program for executing the processing of the brake control device 30.

[0042] The memory 92 includes, for example, non-volatile or volatile semiconductor memories such as RAM (Random Access Memory), ROM (Read-Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable and Programmable Read-Only Memory), as well as magnetic disks, flexible disks, optical disks, compact disks, minidiscs, DVDs (Digital Versatile Discs), and the like.

[0043] The brake control device 30 is connected to the master controller 41, the power supply unit 42, the relay 43, and the mechanical brake devices 1-4 via the interface 93. The interface 93 has one or more interface modules conforming to standards, depending on the connection destination.

[0044] In FIG. 10, one processor 91 and one memory 92 are shown, but the brake control device 30 may be implemented by a plurality of processors 91 and a plurality of memories 92. In this case, each function in the brake control device 30 only needs to be executed through cooperation between the plurality of processors 91 and the plurality of memories 92.

[0045] The brake control device 30 having the above configuration, as an example, continuously executes the brake control process shown in FIG. 11 while the railway vehicle 200 is traveling. Taking the case where the brake control devices 30a and 30b independently perform the same brake control as an example, the biasing mechanism stop processing performed by the brake control device 30a will be described below. The brake control device 30a places the booster mechanism 16 at an initial position, specifically, at a position where the friction material 50 attached to the booster mechanism 16 is separated from the wheel 71 (step S11). Specifically, the drive unit 32 rotates the power source 11 to an initial rotational position, which is the rotational position of the power source 11 when the booster mechanism 16 is at the initial position. It is assumed that the drive unit 32 holds information about the initial rotational position in advance. After rotating the power source 11 to the initial rotational position, the drive unit 32 maintains a state where power supply to the power source 11 is stopped. In addition, in order to arrange the friction material 50 at a position away from the wheel 71, the mechanism control unit 33 turns on the relay 43 and supplies electric power to the switching mechanism 14, thereby putting the switching mechanism 14 into a restricted state. As a result, as shown in FIG. 5, the booster mechanism 16 is located at the initial position, which is the position where the friction material 50 and the wheel 71 are separated from each other.

[0046] As shown in FIG. 11, while the target brake force determination unit 31 provided in the brake control device 30a has not acquired an operation command S1 including a brake command from the master controller 41 (step S12; No), the above processing from step S11 is repeated. Note that arranging the booster mechanism 16 at the initial position in step S11 includes maintaining the position of the booster mechanism 16 that is already at the initial position.

[0047] A target braking force determining unit (31) acquires an operation command S1 including a brake command from a master controller (41) (step S12; Yes). When the brake command includes an urging mechanism operation command (step S13; Yes), a mechanism control unit (33) turns off a relay (43) to stop power supply from a power supply device (42) to a switching mechanism (14), thereby bringing the switching mechanism (14) into an enabled state (step S14). When the switching mechanism (14) is in the enabled state, as shown in FIG. 6, an urging mechanism (13) urges a pressing member (17) toward a booster mechanism (16). As a result, the friction material (50) is pressed against wheels (71-74) by the booster mechanism (16), generating a mechanical braking force.

[0048] Thereafter, as shown in FIG. 11, a driving unit (32) stops power supply to a power source (11) (step S15). It should be noted that stopping the power supply to the power source (11) includes maintaining a state where the power supply has been stopped when the power supply has already been stopped. Until the urging mechanism operation command is canceled (step S16; No), the process of step S16 is repeated. Accordingly, the urging mechanism (13) continues to urge the pressing member (17) toward the booster mechanism (16) until the urging mechanism operation command is canceled, whereby the booster mechanism (16) continues to press the friction material (50) against the wheels (71-74).

[0049] Thereafter, when the urging mechanism operation command is canceled (step S16; Yes), a brake control device (30) performs an urging mechanism stopping process (step S17). In step S17, for example, for a target device which is at least one of the mechanical brake devices 1a-4a, 1b-4b, the brake control device 30a switches the switching mechanism (14) of the target device from an enabled state to a restricted state, and then switches the switching mechanism (14) of another mechanical brake device among the mechanical brake devices 1a-4a, 1b-4b from the enabled state to the restricted state. When the process of step S17 is completed, the above process from step S12 is repeated. As described above, by sequentially bringing the urging mechanisms (13) pressing the pressing member (17) against the booster mechanism (16) into a state where the urging is restricted by the switching mechanisms (14), it is suppressed that the braking force decreases sharply and causes the railway vehicle (200) to roll.

[0050] The control unit 33 receives an operation command S1 including a brake command from the master controller 41 (step S12; Yes), and if the brake command does not include a biasing mechanism operation command, in other words, if a biasing mechanism operation command has not been received (step S13; No), the control unit 33 turns on the relay 43 to allow power supply from the power supply unit 42 to the switching mechanism 14, thereby restricting the switching mechanism 14 (step S18). When the switching mechanism 14 is in a restricted state, the biasing mechanism 13 is restricted from pressing the pressing member 17 against the power assist mechanism 16. Note that restricting the switching mechanism 14 includes maintaining the state of the switching mechanism 14 which is already in a restricted state.

[0051] The target braking force determination unit 31 determines the target braking force, which is the braking force required to achieve the target deceleration (step S19). Specifically, the target braking force determination unit 31 acquires the service brake command, which is a brake command included in the driving command S1, and acquires the weight of the vehicle 201 on which the brake control device 30a is mounted from a load-sensitive detector (not shown). The target braking force determination unit 31 calculates the target braking force for each of the mechanical brake devices 1a-4a and 1b-4b by multiplying the target deceleration indicated by the service brake command by the weight of the vehicle 201 and dividing the result by the number of mechanical brake devices 1a-4a and 1b-4b mounted on the vehicle 201. The target braking force determination unit 31 sends the calculated target braking force to the drive unit 32.

[0052] As described above, while a service brake command is input, in other words, when the switching mechanism 14 is in a restricted state, the drive unit 32 determines a first target torque, which is the target value of the torque of the power source 11 required to obtain the target brake force, from the target brake force determined in step S19 (step S20). Specifically, the speed control unit 34 of the drive unit 32 obtains the target brake force from the target brake force determination unit 31 and obtains the rotational speed of the power source 11 from the sensors 25 of the mechanical brake devices 1a-4a and 1b-4b. From the target brake force, the speed control unit 34 determines the target pressing force, which is the target value of the force with which the mechanical brake device 1a-4a presses the friction material 50 against the wheels 71-74 and the force with which the mechanical brake device 1b-4b presses the friction material 50 against the wheels 71-74.

[0053] The speed control unit 34 determines the first target torque from the target pressing force and the parameters of the mechanical brake devices 1a-4a and 1b-4b. The parameters of the mechanical brake devices 1a-4a and 1b-4b are for converting the pressing force into torque of the power source 11. The parameters for converting the pressing force into torque are determined by the positional relationship of the effort point 16a, fulcrum 16b, and application point 16d of the power assist mechanism 16, the ratio of rotational momentum (input) to linear momentum (output) of the rotation-to-linear motion conversion mechanism 15, etc. The speed control unit 34 is assumed to have pre-stored information on parameters common to the mechanical brake devices 1a-4a and 1b-4b. The speed control unit 34 adjusts the first target torque to gradually increase the rotational speed of the power source 11 and outputs the adjusted first target torque to the torque control unit 35.

[0054] The drive unit 32 drives the power source 11 according to the first target torque (step S21). Specifically, the torque control unit 35 obtains the first target torque of the power source 11 from the speed control unit 34 and obtains the measured value of the output current of the power conversion circuit 36 ​​from the current sensor 37. Specifically, the torque control unit 35 obtains the measured values ​​of the U-phase current and V-phase current from the current sensor 37 and determines the value of the W-phase current from the measured values ​​of the U-phase current and V-phase current. The torque control unit 35 determines the actual torque of the power source 11 from the U-phase current, V-phase current, and W-phase current. The torque control unit 35 performs feedback control based on the first target torque and the actual torque to generate a PWM signal to bring the actual torque closer to the first target torque. The torque control unit 35 outputs the PWM signal to each of the multiple switching elements of the power conversion circuit 36.

[0055] The torque control unit 35 outputs a PWM signal that controls multiple switching elements in the power conversion circuit 36. The power conversion circuit 36 ​​converts the DC power supplied from the power supply unit 42 into three-phase AC power and supplies the three-phase AC power to the power sources 11 of the mechanical brake devices 1a-4a and 1b-4b.

[0056] As described above, when power is supplied to the power source 11, the power source 11 rotates, as shown in Figure 12, and rotational force is transmitted from the drive shaft 11a of the power source 11 to the nut 19a of the ball screw 19 via the gear 18. The output shaft 19b of the ball screw 19 performs linear motion in response to the rotation of the nut 19a.

[0057] When the power source 11 rotates in the forward direction, the output shaft 19b moves toward the power assist mechanism 16. As shown in Figure 12, as the output shaft 19b moves toward the power assist mechanism 16, the point of force application 16a of the power assist mechanism 16 to which one end of the output shaft 19b is attached is pressed. As a result, the arm 16c rotates around the fulcrum 16b. Consequently, the friction material 50 attached to the point of application 16d is pressed against the wheel 71, generating a mechanical braking force.

[0058] As shown in Figure 11, as long as the brake command does not change (step S22; No), the process described above from step S21 is repeated. The brake command not changing means that the target deceleration indicated by the service brake command, which is included in the driving command S1, remains constant.

[0059] When the brake command changes (step S22; Yes), the process described above is repeated from step S12. A change in the brake command includes a change in the target deceleration indicated by the service brake command, which is a brake command included in the driving command S1; a switch in the brake command between the service brake command, the emergency brake command, and the biasing mechanism stop command; and a change from a state in which the driving command S1 includes a brake command to a state in which the driving command S1 includes a power command or a coasting command.

[0060] Figure 13 shows the details of the biasing mechanism stop process in step S17 of Figure 11. The biasing mechanism stop process performed by the brake control device 30a will be described below, using the case where the brake control devices 30a and 30b each independently perform the same biasing mechanism stop process as an example. The drive unit 32 of the brake control device 30a reverses the power source 11 of the mechanical brake devices 1a and 2a, which are provided in correspondence with the target device, for example, the wheels 71 and 72 attached to the axle 75 of the trolley 70a (step S31).

[0061] In detail, when the biasing mechanism operation command included in the operation command S1 acquired from the master controller 41 is released, the torque control unit 35 of the drive unit 32 transmits a PWM signal to the power conversion circuit 36 ​​to reverse the rotation of the power source 11 of the target device.

[0062] As shown in Figure 14, when the power source 11 rotates in the reverse direction, the output shaft 19b of the ball screw 19 moves away from the power assist mechanism 16. As a result, the arm 16c rotates around the pivot point 16b, and the other end of the arm 16c presses the pressing member 17 and the biasing mechanism 13 away from the wheel 71 or wheel 72. In other words, the power assist mechanism 16 pushes the pressing member 17 and the biasing mechanism 13 in the opposite direction to the biasing direction of the biasing mechanism 13. As an example, the torque control unit 35 is assumed to have a predetermined amount of rotation required to move the friction material 50 to the position shown in Figure 14, based on the rotational position of the power source 11 when the friction material 50 is pressed against the wheel 71. The torque control unit 35 rotates the power source 11 in the reverse direction by that amount of rotation.

[0063] When the torque control unit 35 reverses the rotation of the power source 11 to the position shown in Figure 14, it notifies the mechanism control unit 33 of this fact. The torque control unit 35 can determine whether or not the power source 11 has rotated to the position shown in Figure 14 based on the rotation position of the power source 11 obtained from the measurement value of the sensor 25. Upon receiving this notification, the mechanism control unit 33 turns on the relay 43 connected to the mechanical brake devices 1a and 2a, as shown in Figure 13, thereby allowing power supply from the power supply unit 42 to the switching mechanism 14 of the mechanical brake devices 1a and 2a, and thus restricting the switching mechanism 14 of the target device (step S32). When power is supplied from the power supply unit 42 to the switching mechanism 14 and the coil 23 is energized, the armature 22 is attracted to the rotor 21. As a result, the biasing mechanism 13, which is pushed in the opposite direction to the biasing direction of the biasing mechanism 13 by the power boosting mechanism 16, is held by the switching mechanism 14.

[0064] When the mechanism control unit 33 turns on the relay 43 connected to the mechanical brake devices 1a and 2a, it notifies the torque control unit 35 of this fact. Upon receiving this notification, the torque control unit 35 drives the power sources 11 of the mechanical brake devices 1a and 2a according to the second target torque, which is the target value of the torque of the power source 11 for suppressing the rolling of the railway vehicle 200 (step S33).

[0065] In detail, the torque control unit 35 performs feedback control based on the second target torque and the actual torque to generate a PWM signal to bring the actual torque closer to the second target torque. The torque control unit 35 outputs the PWM signal to each of the multiple switching elements in the power conversion circuit 36. The torque control unit 35 is assumed to have information about the second target torque stored in advance. The second target torque is, for example, the same value as the first target torque corresponding to the maximum value of the target deceleration indicated by the service brake command. The multiple switching elements in the power conversion circuit 36 ​​are controlled by the PWM signal output by the torque control unit 35, so that the power conversion circuit 36 ​​converts the DC power supplied from the power supply unit 42 into three-phase AC power and supplies the three-phase AC power to the power source 11 of the mechanical brake unit 1.

[0066] As described above, when power is supplied to the power source 11, the power source 11 rotates, and rotational force is transmitted from the drive shaft 11a of the power source 11 to the nut 19a of the ball screw 19 via the gear 18. The output shaft 19b of the ball screw 19 performs linear motion in response to the rotation of the nut 19a.

[0067] When the power source 11 rotates in the forward direction, the output shaft 19b moves toward the power assist mechanism 16. As shown in Figure 12, as the output shaft 19b moves toward the power assist mechanism 16, the point of force application 16a of the power assist mechanism 16 to which one end of the output shaft 19b is attached is pressed. As a result, the arm 16c rotates around the fulcrum 16b. Consequently, the friction material 50 attached to the point of application 16d is pressed against the wheels 71 and 72, respectively, generating a mechanical braking force.

[0068] As shown in Figure 6, if the biasing mechanism 13 is pressing the pressing member 17 against the power-amplifying mechanism 16, and then the power source 11 generates a mechanical braking force, a large load is placed on the power source 11. For this reason, as described above, it is preferable to stop the biasing mechanism 13 from pressing the power-amplifying mechanism 16 before generating the mechanical braking force with the power source 11.

[0069] In mechanical brake devices 1a and 1b, from the time the biasing mechanism 13 stops pressing the power-boosting mechanism 16 until the output shaft 19b of the ball screw 19 starts pressing the power-boosting mechanism 16 in response to the rotational force of the power source 11, the friction material 50 is located away from the wheels 71 and 72, respectively, and therefore no mechanical braking force is generated. While no mechanical braking force is generated in mechanical brake devices 1a and 2a, in mechanical brake devices 3a, 4a, and 1b-4b, the biasing mechanism 13 presses the power-boosting mechanism 16, thereby generating a mechanical braking force. Similarly in vehicle 202, while no mechanical braking force is generated in mechanical brake devices 1c and 2c, in mechanical brake devices 3c, 4c, and 1d-4d, the biasing mechanism 13 presses the power-boosting mechanism 16, thereby generating a mechanical braking force. As a result, rolling of the railway vehicle 200 is suppressed.

[0070] As shown in Figure 13, the brake control device 30a switches the switching mechanism 14 of the mechanical brake device corresponding to the wheels mounted on both ends of the axle from an allowable state to a restricted state for each control unit including at least one axle. For example, the brake control device 30a switches the biasing mechanism 13 that presses the pressing member 17 against the power assist mechanism 16 from an allowable state to a restricted state at different timings for the axle 76 of the bogie 70a, the axle 75 of the bogie 70b, and the axle 76 of the bogie 70b.

[0071] In detail, the drive unit 32 of the brake control device 30a reverses the power source 11 of the other mechanical brake devices among the mechanical brake devices 1a-4a and 1b-4b, for example, the mechanical brake devices 3a and 4a provided in correspondence with the wheels 73 and 74 attached to the axle 76 of the trolley 70a (step S34). The process in step S34 is the same as the process in step S31.

[0072] Upon receiving notification that the power source 11 has been reversed to the position shown in Figure 14, the mechanism control unit 33 turns on the relay 43 connected to the mechanical brake devices 3a and 4a, as shown in Figure 13, thereby allowing power to be supplied from the power supply unit 42 to the switching mechanism 14 of the mechanical brake devices 3a and 4a, and putting the switching mechanism 14 into a restricted state (step S35). The process in step S35 is the same as the process in step S32.

[0073] Upon receiving notification that relay 43 has been turned on, the drive unit 32 drives the power sources 11 of the mechanical brake devices 3a and 4a in accordance with the second target torque (step S36). The process in step S36 is the same as the process in step S33.

[0074] The brake control device 30a repeats the above process from step S34 until the above process is completed for all mechanical brake devices 1a-4a, 1b-4b that are to be controlled (step S37; No). For example, after performing the above process from steps S34 to S36 for mechanical brake devices 1b, 2b, the brake control device 30a performs the above process from steps S34 to S36 for mechanical brake devices 3b, 4b. Once the above process is completed for all mechanical brake devices 1a-4a, 1b-4b that are to be controlled (step S37; Yes), the brake control device 30a terminates the biasing mechanism stop process.

[0075] After the brake control device 30 has finished the biasing mechanism stop process, it repeats the process from step S12 in Figure 11. At this time, if the operation command S1 obtained from the master controller 41 includes a service brake command or an emergency brake command as a brake command, the drive unit 32 of the brake control device 30a controls the power source 11 according to the first target torque. This generates a mechanical braking force corresponding to the operation in the master controller 41.

[0076] The control unit is not limited to an axle, but may also be a bogie, a wheel, or a vehicle. Furthermore, the control unit may consist of multiple axles, multiple bogies, multiple wheels, or multiple vehicles. As an example, the brake control device 30a may switch the switching mechanism 14 from an allowable state to a restricted state for each control range that includes at least one bogie. In detail, the brake control device 30a may perform the above-described steps S31-S33 at the same timing for the mechanical brake devices 1a-4a mounted on bogie 70a, and then perform the above-described steps S34-S36 at the same timing for the mechanical brake devices 1b-4b mounted on bogie 70b.

[0077] As another example, the brake control device 30a may switch the switching mechanism 14 from an allowable state to a restricted state for each control range that includes at least one wheel. More specifically, the brake control device 30a may perform the above-described steps S31-S33 for mechanical brake device 1a, one of the mechanical brake devices 1a-4a corresponding to the wheels 71, 72, 73, and 74 mounted on the bogie 70a and mechanical brake devices 1b-4b corresponding to the wheels 71, 72, 73, and 74 mounted on the bogie 70b, and then perform the above-described steps S34-S36 for each of the mechanical brake devices 2a-4a and 1b-4b at different timings. Alternatively, the brake control device 30a may perform the above-described steps S31-S33 for mechanical brake devices 1a, 4a, 1b, and 4b, and then perform the above-described steps S34-S36 for mechanical brake devices 2a, 3a, 2b, and 3b.

[0078] As another example, the brake control device 30 may switch the switching mechanism 14 from an allowable state to a restricted state for each control range that includes at least one vehicle. More specifically, the brake control device 30 may perform the above-described steps S31-S33 at the same timing for the mechanical brake devices 1a-4a, 1b-4b mounted on vehicle 201, and then perform the above-described steps S34-S36 at the same timing for the mechanical brake devices 1c-4c, 1d-4d mounted on vehicle 202. In this case, the brake control device 30 may be mounted on only one of the vehicles 201 or 202, or it may be implemented as a brake control circuit 30c mounted on vehicle 201 and a brake control circuit 30d mounted on vehicle 202, as shown in Figure 15. The configuration of the brake control circuits 30c and 30d is the same as that of the brake control device 30 shown in Figures 7 and 8.

[0079] If a brake malfunction occurs, for example, in the power supply unit 42, the drive unit 32, or the electrical circuit from the power supply unit 42 through the drive unit 32 to the power source 11, the power source 11 will be unable to generate mechanical braking force. The operation of the mechanical brake device 1 and the brake control device 30 in the event of a brake malfunction will be described below.

[0080] For example, if a malfunction occurs in the power supply unit 42, the mechanical brake device 1-4 generates a mechanical brake force by pressing the power assist mechanism 16 with the biasing mechanism 13, independently of the control of the brake control device 30. When a malfunction occurs in the power supply unit 42, the power supply from the power supply unit 42 to the switching mechanism 14 is stopped regardless of the operation of the mechanism control unit 33, so that the switching mechanism 14 enters an acceptable state.

[0081] When the switching mechanism 14 is in an acceptable state, specifically when the coil 23 is demagnetized, the rotor 21 and the armature 22 are positioned apart from each other, as shown in Figure 6. This allows the movement of the pressing member 17 attached to the armature 22 and the biasing mechanism 13 attached to the pressing member 17. Also, because the coil 23 is demagnetized, the spring of the biasing mechanism 13, which was attracted to the rotor 21, is released, and the length of the spring returns to its natural length. In other words, the biasing mechanism 13 is allowed to press the power-amplifying mechanism 16 by biasing the pressing member 17 against the power-amplifying mechanism 16. When the biasing mechanism 13 presses the other end of the power-amplifying mechanism 16, the friction material 50 is pressed against the wheel 71, generating a mechanical braking force.

[0082] As another example, if an abnormality occurs in either the drive unit 32 or the electrical circuit from the power supply unit 42 to the power source 11 via the drive unit 32, mechanical braking force will not be obtained even though the operation command S1 includes a brake command. The mechanism control unit 33 turns off the relay 43 if the period during which the actual torque deviates from the target torque continues for a predetermined reference period or longer when the operation command S1 includes a brake command. As a result, the power supply from the power supply unit 42 to the switching mechanism 14 is stopped, the switching mechanism 14 enters an acceptable state, and mechanical braking force is generated as described above.

[0083] The reference period can be determined according to the rise time caused by the mechanical operation of the mechanical brake device 1-4. When the actual torque deviates from the target torque, it means that the railway vehicle 200 is not being decelerated by the mechanical braking force of the mechanical brake device 1-4, for example, when the actual torque is less than 63% of the target torque. The mechanism control unit 33 can obtain the operation command S1 from the master controller 41 and the target torque and actual torque from the drive unit 32.

[0084] As described above, in the event of a brake malfunction, the switching mechanism 14 automatically enters an acceptable state, specifically independently of the operation of the mechanism control unit 33, and a mechanical braking force is generated by the biasing mechanism 13. Subsequently, for example, when a power command is input to the master controller 41, the brake control device 30 performs the biasing mechanism stop process shown in Figure 13. As a result, even when a mechanical braking force is automatically generated by the biasing mechanism 13 due to a brake malfunction, the rolling of the railway vehicle 200 is suppressed.

[0085] As described above, the brake control device 30 according to Embodiment 1 switches the switching mechanism 14 of at least one of the mechanical brake devices 1-4 from an allowable state to a restricted state, and then switches the switching mechanism 14 of the other mechanical brake devices from an allowable state to a restricted state. As a result, it becomes possible to suppress the rolling of the moving body on which the brake control device 30 is mounted.

[0086] (Embodiment 2) The configuration of the mechanical brake device 1-4 is not limited to the example described above. Embodiment 2 will describe a brake control device 30 that controls a mechanical brake device with a configuration different from that of the mechanical brake device 1-4 according to Embodiment 1, focusing on the differences from Embodiment 1.

[0087] The mechanical brake device 5 according to Embodiment 2 is provided corresponding to each of the wheels 71-74, similar to the mechanical brake devices 1-4. The configuration of the mechanical brake device 5 is the same as that of the mechanical brake device 1 shown in Figure 3, but as shown in Figure 16, the rotary-to-linear motion conversion mechanism 15 and the biasing mechanism 13 press the power assist mechanism 16 in the same direction. The power source 11 is, for example, a hollow motor through which the output shaft 15b of the rotary-to-linear motion conversion mechanism 15 is inserted. A through hole is formed in the center of the pressing member 17 attached to one end of the biasing mechanism 13, and the output shaft 15b of the rotary-to-linear motion conversion mechanism 15 is inserted through the through hole of the pressing member 17.

[0088] In detail, the mechanical brake device 5 has a rotary-to-linear motion conversion mechanism 15 which is a ball screw that receives rotational force from a power source 11. The rotary-to-linear motion conversion mechanism 15 includes a nut 15a that fits onto a drive shaft 11a, an output shaft 15b that performs linear motion in accordance with the rotation of the nut 15a, a solenoid 15c provided at one end of the output shaft 15b, a locking member 15e housed in a hole 15d formed at one end of the output shaft 15b, and a biasing member 15f that biases the locking member 15e radially with respect to the direction of motion of the output shaft 15b. The solenoid 15c is provided around the hole 15d. The biasing member 15f is, for example, a coil spring.

[0089] As shown in Figure 16, when the power assist mechanism 16 is in its initial position and no power is supplied to the solenoid 15c, in other words, when the solenoid 15c is demagnetized, the locking member 15e, which is biased by the biasing member 15f, is partially housed in the hole 17a formed in the pressing member 17. The locking member 15e, with part of it housed in the hole 17a, locks into the pressing member 17, causing the rotary-to-linear motion conversion mechanism 15, the pressing member 17, and the biasing mechanism 13, one end of which is attached to the pressing member 17, to move together as a single unit.

[0090] The brake control system 101 shown in Figure 17 comprises a brake control device 30 that controls the mechanical brake device 5, and the mechanical brake device 5. In Figure 17, only one mechanical brake device 5 is shown to avoid complicating the diagram, but the brake control device 30 controls multiple mechanical brake devices 5 that are provided in correspondence with each of the wheels 71, 72, 73, and 74 on each trolley 70.

[0091] The configuration of the brake control device 30 according to Embodiment 2 is the same as the configuration of the brake control device 30 according to Embodiment 1. The mechanism control unit 33 of the brake control device 30 switches the on and off of relay 44 in addition to relay 43. By switching the on and off of relay 44, the mechanism control unit 33 allows or stops the power supply from the power supply device 42 to the solenoid 15c.

[0092] The hardware configuration of the brake control device 30 according to Embodiment 2 is the same as that of the brake control device 30 according to Embodiment 1. The brake control device 30 according to Embodiment 2 is connected to the master controller 41, the power supply unit 42, the relays 43 and 44, and the mechanical brake device 1-4 via the interface 93.

[0093] The brake control process performed by the brake control device 30 is the same as the brake control process performed by the brake control device 30 according to Embodiment 1 shown in Figure 11. In step S11, the drive unit 32 rotates the power source 11 to the initial rotation position, which is the rotation position of the power source 11 when the power assist mechanism 16 is in its initial position. At this time, the mechanism control unit 33 stops the power supply from the power supply device 42 to the solenoid 15c by turning off the relay 44. As a result, as shown in Figure 18, the locking member 15e protrudes radially and a part of it is positioned in the hole 17a of the pressing member 17, causing the rotary-to-linear motion conversion mechanism 15, the pressing member 17, and the biasing mechanism 13 to move linearly as a whole. In the state shown in Figure 18, the relay 43 is off and the switching mechanism 14 is in an allowable state. Also, the rotary-to-linear motion conversion mechanism 15 is in contact with the power assist mechanism 16, but it is not pressing the power assist mechanism 16.

[0094] As shown in Figure 18, from the initial position of the rotary-to-linear motion conversion mechanism 15, the drive unit 32 reverses the rotation of the power source 11. As a result, the pressing member 17 is returned to the position shown in Figure 16. As an example, the torque control unit 35 of the drive unit 32 is assumed to have a predetermined amount of rotation required to move the pressing member 17 to the position shown in Figure 16, based on the rotational position of the power source 11 when the rotary-to-linear motion conversion mechanism 15 is in its initial position. The torque control unit 35 reverses the rotation of the power source 11 by that amount of rotation. The mechanism control unit 33 sets the switching mechanism 14 to a restricted state by turning on the relay 43. When the coil 23 is energized, the armature 22 is attracted to the rotor 21. Because the rotor 21 and the armature 22 are meshed with each other, the rotation of the armature 22 is restricted, and the movement of the pressing member 17 attached to the armature 22 and the biasing mechanism 13 attached to the pressing member 17 is restricted. Furthermore, the mechanism control unit 33 energizes the solenoid 15c by turning on the relay 44. As a result, as shown in Figure 19, the entire locking member 15e is housed in the hole 15d.

[0095] As shown in Figure 11, the target brake force determination unit 31 receives an operation command S1 including a brake command from the master controller 41 (step S12; Yes), and if the brake command includes a biasing mechanism operation command (step S13; Yes), the mechanism control unit 33 turns off the relay 43 and stops the power supply from the power supply unit 42 to the switching mechanism 14, thereby putting the switching mechanism 14 into an acceptable state (step S14). The mechanism control unit 33 also turns off the relay 44 and stops the power supply to the solenoid 15c.

[0096] When the switching mechanism 14 enters the permissible state, the spring, which is the biasing mechanism 13, returns to its natural length, causing the pressing member 17, which is biased by the biasing mechanism 13, to move toward the power-amplifying mechanism 16. Also, when the power supply to the solenoid 15c is stopped and the solenoid 15c becomes demagnetized, the locking member 15e protrudes radially. For example, if the pressing member 17 moves toward the power-amplifying mechanism 16 before the locking member 15e moves into the hole 17a of the pressing member 17, then, as shown in Figure 20, the pressing member 17, which is biased by the biasing mechanism 13, presses against the power-amplifying mechanism 16, generating a mechanical braking force. The subsequent steps S15 and S16 in Figure 11 are the same as in Embodiment 1.

[0097] In step S31 of the biasing mechanism stop process shown in Figure 13, which is performed in step S17 of Figure 11, the mechanism control unit 33 turns on the relay 44 to allow power supply to the solenoid 15c. As a result, the locking member 15e is housed in the hole 15d of the output shaft 15b. The drive unit 32 moves the output shaft 15b from the position shown in Figure 20 to the position shown in Figure 21 by rotating the power source 11 in the forward direction. As an example, the torque control unit 35 is assumed to have a predetermined amount of rotation required to move the output shaft 15b from the position shown in Figure 20 to the position shown in Figure 21. The torque control unit 35 rotates the power source 11 in the forward direction by that amount of rotation.

[0098] In the state shown in Figure 21, the mechanism control unit 33 turns off the relay 44 and stops the power supply to the solenoid 15c. As a result, the locking member 15e protrudes into the hole 17a of the pressing member 17 and locks onto the pressing member 17. Consequently, the rotary-to-linear motion conversion mechanism 15, the pressing member 17, and the biasing mechanism 13 become movable as a single unit. Subsequently, the drive unit 32 moves the rotary-to-linear motion conversion mechanism 15, the pressing member 17, and the biasing mechanism 13 from the position shown in Figure 21 to the position shown in Figure 16 by reversing the rotation of the power source 11. As an example, the torque control unit 35 is assumed to have a predetermined amount of rotation required to move the output shaft 15b from the position shown in Figure 21 to the position shown in Figure 16. The torque control unit 35 reverses the rotation of the power source 11 by that amount of rotation.

[0099] In step S32 of Figure 13, the mechanism control unit 33 turns on the relay 43 to limit the switching mechanism 14. In step S33 of Figure 13, the mechanism control unit 33 turns on the relay 44 to allow power supply to the solenoid 15c, and the drive unit 32 drives the power source 11 according to the second target torque. As a result, as shown in Figure 22, the output shaft 15b presses the power assist mechanism 16 while the positions of the biasing mechanism 13 and the pressing member 17 are maintained. As a result, a mechanical braking force is generated.

[0100] Subsequently, similar to the first embodiment, the brake control device 30 sequentially sets the switching mechanism 14 to a restricted state for each control unit. This suppresses the rolling of the railway vehicle 200.

[0101] The process in steps S18-S20 of Figure 11 is the same as in Embodiment 1. In step S21, the mechanism control unit 33 turns on the relay 44 to allow power supply to the solenoid 15c, and the drive unit 32 drives the power source 11 according to the first target torque. As a result, as shown in Figure 22, the output shaft 15b presses against the power assist mechanism 16. As a result, a mechanical braking force is generated. The process in step S22 of Figure 11 is the same as in Embodiment 1.

[0102] When the power supply unit 42 malfunctions, the power supply from the power supply unit 42 to the switching mechanism 14 and the solenoid 15c is stopped, regardless of the operation of the mechanism control unit 33. As a result, the switching mechanism 14 enters an open state, and the locking member 15e protrudes radially. For example, in the state shown in Figure 22, if a malfunction occurs in the power supply unit 42, as shown in Figure 23, the pressing member 17 moves toward the power assist mechanism 16 and locks into the protruding locking member 15e. This causes the pressing member 17 to push the output shaft 15b toward the power assist mechanism 16. As a result, the output shaft 15b presses against the power assist mechanism 16, generating a mechanical braking force.

[0103] Subsequently, when the power supply unit 42 returns to normal operation, the mechanism control unit 33 turns off relay 43 and turns on relay 44. As a result, as shown in Figure 24, the locking member 15e is housed in the hole 15d, and the pressing member 17 moves toward the power assist mechanism 16. From the state in Figure 24, when the mechanism control unit 33 turns off relay 44, the locking member 15e protrudes radially and locks onto the pressing member 17. Subsequently, the drive unit 32 reverses the rotation of the power source 11, causing the pressing member 17 and output shaft 15b to return to the position shown in Figure 19. As an example, the torque control unit 35 is assumed to have a predetermined amount of rotation required to move the output shaft 15b from the position shown in Figure 24 to the position shown in Figure 19. The torque control unit 35 reverses the rotation of the power source 11 by that amount of rotation.

[0104] As described above, the brake control device 30 according to Embodiment 2 controls a mechanical brake device 5 which includes a rotation-to-linear motion conversion mechanism 15 and a biasing mechanism 13 that press the power assist mechanism 16 in the same direction, and when the biasing mechanism operation command is released, the switching mechanism 14 is sequentially set to a restricted state for each control unit, thereby suppressing the rolling of the railway vehicle 200.

[0105] This disclosure is not limited to the embodiments described above. The mechanical brake device 1-5 is not limited to the examples described above. For example, the power source 11 and the rotary-to-linear motion conversion mechanism 15 of the mechanical brake device 1-4 may be implemented with electric actuators.

[0106] The switching mechanism 14 is not limited to the above example, and is any clutch that can switch between an allowable state in which the biasing mechanism 13 is allowed to bias the pressing member 17 toward the power-multiplier mechanism 16, and a restricting state in which the biasing mechanism 13 is restricted from biasing the pressing member 17 toward the power-multiplier mechanism 16. The switching mechanism 14 is not limited to an electromagnetic clutch, but may also be a mechanical clutch. The mechanism control unit 33 can switch between the allowable state and the restricting state of the switching mechanism 14 using a control method appropriate to the structure of the switching mechanism 14. Furthermore, the installation position of the switching mechanism 14 is not limited to the above example, and may be any position that holds the coil spring, which is the biasing mechanism 13, shorter than its natural length in the restricting state, and allows the biasing mechanism 13 to bias the power-multiplier mechanism 16 in the allowable state.

[0107] The rotation-to-linear motion conversion mechanism 15 is not limited to the above example, but is any mechanism that converts rotational motion to linear motion. For example, the rotation-to-linear motion conversion mechanism 15 may have a ball spline that performs linear motion in response to the rotational force transmitted from the power source 11 via the gear 18.

[0108] The power assist mechanism 16 is not limited to a lever mechanism; for example, it may be a toggle mechanism, a link mechanism, or the like.

[0109] The target braking force determination unit 31 may acquire the operation command S1 from a train information management system, ATC, ATS (Automatic Train Stop), etc.

[0110] The drive unit 32 may determine the rotational position and amount of rotation of the power source 11 based on measurement results from a load sensor provided on the power assist mechanism 16, a photosensor provided near the power assist mechanism 16, a rotation angle sensor attached to the power assist mechanism 16, etc., instead of the pulse detection sensor 25.

[0111] The power supply unit 42 may be installed in only one of the vehicles 201 or 202. For example, the power supply unit 42 may be installed in vehicle 201 and supply power to the brake control device 30a installed in vehicle 201 and the brake control device 30b installed in vehicle 202. In this case, the power supply unit 42 may be connected to the mechanical brake devices 1a-4a and 1b-4b installed in vehicle 201 via relay 43a, and to the mechanical brake devices 1c-4c and 1d-4d installed in vehicle 202 via relay 43b. Relay 43b may be installed in either vehicle 201 or vehicle 202.

[0112] The mechanical brake devices 1-5 and the brake control device 30 are not limited to the railway vehicle 200, but may also be installed on other mobile vehicles such as automobiles and trolleybuses.

[0113] The number of vehicles that the railway vehicle 200 has is not limited to the example described above; the railway vehicle 200 may have only one vehicle or three or more vehicles. Also, the number of bogies 70 that the railway vehicle 200 has is not limited to the example described above; the railway vehicle 200 may have articulated bogies.

[0114] The rotating body is not limited to wheels 71-74, but may also be a disc rotor. In this case, the friction material 50 may be a brake pad.

[0115] The railway vehicle 200 equipped with the brake control device 30 may be a railway vehicle that decelerates by electric braking force generated by consuming the power generated when the main motor that generates the propulsion force of the railway vehicle 200 operates as a generator, and by mechanical braking force from the mechanical braking device 1-5. In this case, the target brake force determination unit 31 determines the target electric brake force, which is the target value of the electric brake force, from the target brake force, and sends a regenerative pattern corresponding to the target electric brake force to the control circuit of the power conversion device that supplies power to the main motor. The target brake force determination unit 31 also obtains regenerative feedback from the control circuit of the power conversion device that indicates the actual electric brake force, which is the electric brake force that was actually generated, and determines the target mechanical brake force, which is the target value of the mechanical brake force, by subtracting the actual electric brake force indicated by the regenerative feedback from the target brake force. The speed control unit 34 determines the first target torque from the target mechanical brake force.

[0116] The hardware configuration and flowchart shown above are examples and can be changed and modified as needed.

[0117] As an example, a modified example of the hardware configuration of the brake control device 30 is shown in Figure 25. The brake control device 30 according to Embodiment 1 may be implemented with a processing circuit 94, as shown in Figure 25. The processing circuit 94 shown in Figure 25 is connected to an external device via an interface circuit 95. In detail, the brake control device 30 is connected to a master controller 41, a power supply 42, a relay 43, and a mechanical brake device 1-4 via the interface circuit 95. The same applies to the brake control device 30 according to Embodiment 2. The brake control device 30 according to Embodiment 2 is connected to a master controller 41, a power supply 42, a relay 43, and a mechanical brake device 5 via the interface circuit 95.

[0118] If the processing circuit 94 is dedicated hardware, the processing circuit 94 may be, for example, a single circuit, a composite circuit, a processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. In the brake control device 30, each part may be implemented by an individual processing circuit 94, or each part may be implemented by a common processing circuit 94.

[0119] Some functions of the brake control device 30 may be implemented by dedicated hardware, while other functions may be implemented by software or firmware. For example, in the brake control device 30, the drive unit 32 and the mechanism control unit 33 may be implemented by the processing circuit 94 shown in Figure 25, and the target brake force determination unit 31 may be implemented by the processor 91 shown in Figure 10 reading and executing a program stored in the memory 92.

[0120] A brake control device 30 that performs the above-described operations may be realized by distributing a computer-readable recording medium such as a flexible disk, CD-ROM (Compact Disc-Read Only Memory), or DVD-ROM (Digital Versatile Disc-Read Only Memory) containing a computer program for performing the above-described operations, and installing the computer program on a computer. Alternatively, a brake control device 30 that performs the above-described operations may be realized by a dedicated system. The computer program may be superimposed on a carrier wave and provided via a communication network.

[0121] This disclosure allows for various embodiments and modifications without departing from the broad spirit and scope of this disclosure. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of this disclosure. In other words, the scope of this disclosure is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of the disclosure are considered to be within the scope of this disclosure.

[0122] 1, 1a, 1b, 1c, 1d, 2, 2a, 2b, 2c, 2d, 3, 3a, 3b, 3c, 3d, 4, 4a, 4b, 4c, 4d, 5 Mechanical brake device, 11 Power source, 11a Drive shaft, 12 Pressing mechanism, 13 Biasing mechanism, 14 Switching mechanism, 15 Rotary-to-linear motion conversion mechanism, 15a Nut, 15b Output shaft, 15c Solenoid, 15d Hole, 15e Locking member, 15f Biasing member, 16 Force boosting mechanism, 16a Point of force application, 16b Pivot, 16c Arm, 16d Point of application, 17 Pressing member, 17a Hole, 18 Gear, 19 Ball screw, 19a Nut, 19b Output shaft, 20 Mounting member, 21 Rotor, 22 Armature, 23 Coil, 24 100, 101 200 300 300 300 300 300 300 300 300 300 300 300 300 300 31 300 300 300 31 300 3200 31 300 300 31 300 300 Railway vehicles, vehicles 201 and 202, S1 operation control.

Claims

1. A brake control device for controlling a plurality of mechanical brake devices, each provided for a rotating body that rotates when the moving body is in motion, which generate a mechanical brake force, comprising: a power source that rotates when driven by supplied electricity; a pressing mechanism that generates the mechanical brake force by pressing a friction material against the rotating body in accordance with the rotational force transmitted from the power source; a biasing mechanism that generates the mechanical brake force by biasing the friction material toward the rotating body; and a switching mechanism that is in either an allowable state that allows the biasing mechanism to bias the friction material toward the rotating body or a restricting state that restricts the biasing mechanism from biasing the friction material toward the rotating body, wherein the control device sets the switching mechanism to the allowable state when it receives a biasing mechanism operation command that instructs the operation of the biasing mechanism, and sets the switching mechanism to the restricting state when it has not received the biasing mechanism operation command; and a target brake force determination unit that receives a brake command for the moving body and determines a target brake force which is the brake force to obtain the target deceleration indicated by the brake command. A brake control device comprising: a drive unit that, when the switching mechanism is in the limiting state, determines a first target torque, which is a target value of the torque of the power source, from the target braking force, and drives the power source according to the first target torque, wherein when the biasing mechanism operation command is released, the mechanism control unit switches the switching mechanism of at least one of the target devices, which is a mechanical brake device among the plurality of mechanical brake devices, from the allowable state to the limiting state, and then switches the switching mechanism of the other mechanical brake devices among the plurality of mechanical brake devices from the allowable state to the limiting state.

2. The brake control device according to claim 1, wherein, when the biasing mechanism operation command is released, the mechanism control unit, in the moving body which is a railway vehicle having a plurality of vehicles, switches the switching mechanism of each of the target devices, which are a plurality of mechanical brake devices mounted on at least one of the vehicles, from the permissible state to the restricted state, and then, for each control unit including at least one vehicle, switches the switching mechanism of each of the plurality of mechanical brake devices mounted on the vehicle corresponding to the control unit from the permissible state to the restricted state.

3. The brake control device according to claim 1, wherein, when the biasing mechanism operation command is released, the mechanism control unit, in the moving body which is a railway vehicle having a plurality of bogies, switches the switching mechanism of each of the target devices, which are a plurality of mechanical brake devices corresponding to a plurality of wheels attached to at least one of the bogies, from the permissible state to the restricted state, and then, for each control unit including at least one of the bogies, switches the switching mechanism of each of the plurality of mechanical brake devices corresponding to a plurality of vehicles attached to the bogie corresponding to the control unit, from the permissible state to the restricted state.

4. The brake control device according to claim 1, wherein when the biasing mechanism operation command is released, the mechanism control unit, with respect to the target devices which are a plurality of mechanical brake devices corresponding to the wheels attached to both ends of at least one axle, switches the switching mechanism of each target device from the allowable state to the limiting state, and then, for each control unit including at least one axle, switches the switching mechanism of each of the plurality of mechanical brake devices corresponding to the wheels attached to both ends of the axle corresponding to the control unit from the allowable state to the limiting state.

5. The brake control device according to claim 1, wherein when the biasing mechanism operation command is released, the mechanism control unit, with respect to at least one of the target devices which is a mechanical brake device corresponding to one of the multiple mechanical brake devices provided for each of the rotating bodies which are wheels, switches the switching mechanism of each target device from the allowable state to the limiting state, and then, for each control unit including at least one of the wheels, switches the switching mechanism of the mechanical brake device corresponding to the wheel corresponding to the control unit from the allowable state to the limiting state.

6. When the biasing mechanism operation command is released, the drive unit reverses the power source of the target device so that the pushing mechanism of the target device pushes the biasing mechanism of the target device in the opposite direction to the biasing direction of the biasing mechanism, and then reverses the power source of one of the other mechanical brake devices so that the pushing mechanism of the other mechanical brake device pushes the biasing mechanism of the other mechanical brake device in the opposite direction to the biasing direction of the biasing mechanism, and the mechanism control unit switches the switching mechanism from the allowable state to the limiting state while the biasing mechanism is pushed by the pushing mechanism in the opposite direction to the biasing direction, the brake control device according to any one of claims 1 to 5.

7. The brake control device according to claim 6, wherein when the biasing mechanism operation command is released, the drive unit reverses the rotation of the power source of the target device, thereby using the pressing mechanism of the target device to push the biasing mechanism of the target device in the opposite direction to the biasing direction of the biasing mechanism, and then drives the power source of the target device in accordance with a second target torque, which is a target value of the torque of the power source for suppressing the rolling of the moving body, and then reverses the rotation of the power source of one of the plurality of mechanical brake devices, thereby using the pressing mechanism of the other mechanical brake device to push the biasing mechanism of the other mechanical brake device in the opposite direction to the biasing direction of the biasing mechanism, and then drives the power source of the other mechanical brake device in accordance with the second target torque.

8. The brake control device according to claim 7, wherein the drive unit drives the drive units of all the mechanical brake devices in accordance with the second target torque, and then drives the power sources of all the mechanical brake devices in accordance with the first target torque.

9. The brake control device according to any one of claims 1 to 8, wherein the drive unit stops the power source when the switching mechanism enters the permissible state in response to the biasing mechanism operation command.

10. A brake control method performed by a brake control device that controls a plurality of mechanical brake devices, each provided for a rotating body that rotates when the moving body is in motion, the plurality of mechanical brake devices comprising: a power source that rotates when driven by supplied electricity; a pressing mechanism that generates the mechanical brake force by pressing a friction material against the rotating body in accordance with the rotational force transmitted from the power source; a biasing mechanism that generates the mechanical brake force by biasing the friction material toward the rotating body; and a switching mechanism that is in either an allowable state that allows the biasing mechanism to bias the friction material toward the rotating body or a restricting state that restricts the biasing mechanism from biasing the friction material toward the rotating body, wherein when a biasing mechanism operation command instructing the operation of the biasing mechanism is obtained, the switching mechanism is set to the allowable state, and when the biasing mechanism operation command has not been obtained, the switching mechanism is set to the restricting state; a brake command for the moving body is obtained, and a target brake force, which is the brake force required to obtain the target deceleration indicated by the brake command, is determined. A brake control method comprising: determining a first target torque, which is a target value of the torque of the power source, from the target braking force when the switching mechanism is in the limiting state; driving the power source according to the first target torque; and when the biasing mechanism operation command is released, switching the switching mechanism of at least one of the target devices, which is a mechanical brake device, from the allowable state to the limiting state, and then switching the switching mechanism of the other mechanical brake devices from the allowable state to the limiting state.

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