Brake device, operation abnormality determination method, and operation abnormality determination program

Abstract

To provide a brake device which can recognize operation abnormality of the brake device on the basis of information acquired from the brake device.SOLUTION: The brake device brakes a wheel by driving a friction member which is pressed to a member subjected to friction as either a wheel or a rotation body rotating integrally with the wheel. The brake device includes an acquisition part which acquires drive information of an electric actuator, a calculation part which calculates a calculated value which is at least either a moving distance of the friction member or a required time for the friction member to reach a predetermined position on the basis of the acquired drive information, and a determination part which determines operation abnormality by comparing the calculated value and a reference value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a brake device, an operation abnormality determination method, and an operation abnormality determination program. [Background technology]

[0002] Patent Document 1 describes an electric brake device that uses a motor as a power source to bring brake shoes into contact with a disk to obtain braking force. The electric brake device applies brakes to the wheels of a railway vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-19893 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the electric brake device as described above, an operational abnormality in the brake device is detected when the railway vehicle does not decelerate despite a brake command. For this reason, there is a need to detect an operational abnormality in the electric brake device based on information acquired from the electric brake device. Note that similar issues exist not only in electric brake devices for railway vehicles, but also in other electric brake devices. [Means for solving the problem]

[0005] The brake device that solves the above problem is a brake device that brakes a wheel by driving a friction material pressed against a friction target material, which is either a wheel or a rotating body that rotates integrally with the wheel, using an electric actuator, and is equipped with an acquisition unit that acquires drive information of the electric actuator, a calculation unit that calculates a calculated value that is at least one of the travel distance of the friction material and the time required for the friction material to reach a predetermined position based on the acquired drive information, and a judgment unit that compares the calculated value with a reference value to judge an operational abnormality.

[0006] According to the above configuration, the determination unit compares at least one of the travel distance and the required time of the friction material calculated by the calculation unit based on the drive information acquired by the acquisition unit with a reference value to determine an operational abnormality, so that the operational abnormality of the brake device can be identified based on the information acquired from the brake device.

[0007] For the above-mentioned brake device, it is preferable that the drive information is a current value of the electric actuator, and the calculated value is at least one of the travel distance and the required time when the current value reaches the current value when the friction material comes into contact with the frictioned material or a foreign object.

[0008] For the above-mentioned brake device, it is preferable that the drive information is a current value of the electric actuator, and the calculated value is at least one of the travel distance and the required time when the current value corresponds to a predetermined braking force.

[0009] For the above-mentioned brake device, it is preferable that the drive information is a current value of the electric actuator, and the calculated value is at least one of the travel distance and the required time when the current value corresponds to a target braking force.

[0010] For the above-mentioned brake device, it is preferable that the drive information is a current value of the electric actuator, and the calculated value is the required time from when the current value when the friction material comes into contact with the frictioned material or a foreign object to when the current value corresponds to a predetermined braking force.

[0011] In the above brake device, it is preferable that the drive information is a current value of the electric actuator, and the calculated value is the required time from acquisition of a brake command to when current flows through the electric actuator and the actuator starts up.

[0012] In the above brake device, it is preferable that the reference value is at least one of the travel distance and the required time in a normal state or in the past. For the above brake device, it is preferable that the reference value is at least one of the travel distance and the required time of a friction material of another brake device in the same train.

[0013] In the above brake device, it is preferable that the start point of the travel distance and the required time is the time point when the electric actuator is started. In the above-mentioned braking device, when brake control is performed in which the gradient of deceleration of the braking device is constant, the determination unit preferably compares the braking device with the reference value in a brake command under the same conditions.

[0014] The method for determining an operation abnormality that solves the above-mentioned problem is a method for determining an operation abnormality of a brake device that brakes a wheel by driving a friction material that is pressed against a friction target material, which is either a wheel or a rotating body that rotates integrally with the wheel, by an electric actuator, and includes an acquisition step of acquiring driving information of the electric actuator, a calculation step of calculating a calculated value that is at least one of the travel distance of the friction material and the time required for the friction material to reach a predetermined position based on the acquired driving information, and a determination step of comparing the calculated value with a reference value to determine an operation abnormality.

[0015] According to the above method, at least one of the travel distance and the required time of the friction material calculated based on the acquired drive information is compared with a reference value to determine an operational abnormality, so that an operational abnormality of the brake device can be identified based on information acquired from the brake device.

[0016] The operation abnormality detection program that solves the above problem is an operation abnormality detection program for a brake device that brakes a wheel by driving a friction material that is pressed against a friction target material, which is either a wheel or a rotating body that rotates integrally with the wheel, using an electric actuator, and causes a computer to execute an acquisition step of acquiring driving information of the electric actuator, a calculation step of calculating a calculated value that is at least one of the traveled distance of the friction material and the time required for the friction material to move based on the acquired driving information, and a determination step of comparing the calculated value with a reference value to determine an operation abnormality.

[0017] According to the program, at least one of the travel distance and the required time of the friction material calculated based on the acquired drive information is compared with a reference value to determine an operational abnormality, so that an operational abnormality of the brake device can be identified based on information acquired from the brake device. Effect of the Invention

[0018] According to the present invention, an operational abnormality in the brake device can be detected based on information acquired from the brake device. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing a configuration of a brake device according to a first embodiment. [Diagram 2] 5 is a diagram showing a change in deceleration over time according to the embodiment; FIG. [Diagram 3] 5 is a diagram showing a change in deceleration over time according to the embodiment; FIG. [Figure 4] 5 is a diagram showing changes in a brake command and a current value of a motor during braking in the embodiment; FIG. [Diagram 5]5 is a diagram showing changes in a brake command and a motor current value during release in the embodiment; FIG. [Figure 6] 4 is a flowchart showing a state monitoring process performed by the brake device of the embodiment. [Figure 7] 5 is a diagram showing changes in a brake command and a current value of a motor during braking in the embodiment; FIG. [Figure 8] 5 is a diagram showing changes in a brake command and a motor current value during release in the embodiment; FIG. [Figure 9] FIG. 11 is a diagram showing changes in a brake command and a current value of a main power supply during braking in the second embodiment. [Figure 10] 5 is a diagram showing changes in the brake command and the current value of the main power supply during release in the embodiment; FIG. [Figure 11] 5 is a diagram showing changes in a brake command and a current value of a main power supply during braking in the embodiment; FIG. [Figure 12] 5 is a diagram showing changes in the brake command and the current value of the main power supply during release in the embodiment; FIG. [Figure 13] FIG. 13 is a diagram showing changes in a brake command and a current value of a motor during braking in the third embodiment. [Figure 14] 5 is a diagram showing changes in a brake command and a motor current value during release in the embodiment; FIG. [Figure 15] 5 is a diagram showing changes in a brake command and a current value of a motor during braking in the embodiment; FIG. [Figure 16] 5 is a diagram showing changes in a brake command and a motor current value during release in the embodiment; FIG. [Figure 17] FIG. 13 is a diagram showing changes in a brake command and a current value of a main power supply during braking in the fourth embodiment. [Figure 18] 5 is a diagram showing changes in the brake command and the current value of the main power supply during release in the embodiment; FIG. [Figure 19] 5 is a diagram showing changes in a brake command and a current value of a main power supply during braking in the embodiment; FIG. [Figure 20] 5 is a diagram showing changes in the brake command and the current value of the main power supply during release in the embodiment; FIG. [Figure 21] FIG. 13 is a schematic diagram showing the configuration of a brake device according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (First embodiment) A first embodiment of a braking device will be described below with reference to Figures 1 to 8. The braking device is provided in a railway vehicle.

[0021] As shown in FIG. 1, the brake device 10 is a tread brake device that generates a braking force by pressing a brake shoe 14 against a tread surface 2A of a wheel 2 of a railway vehicle. The brake device 10 includes a rotary motor 11 and is driven by the motor 11. The brake device 10 includes a transmission unit 12 that transmits the driving force of the motor 11 to the brake shoe 14, and a brake shoe holding member 13. The transmission unit 12 displaces the brake shoe holding member 13 by the driving force of the motor 11. The transmission unit 12 is provided with a holding mechanism 12A. The holding mechanism 12A holds the pressing force of the brake shoe holding member 13 even when the driving of the motor 11 is stopped. The holding mechanism 12A uses a one-way clutch or the like that mechanically holds the position of the brake shoe holding member 13. The holding mechanism 12A releases the holding when rotated in the releasing direction. In the brake device 10 including the holding mechanism 12A, the driving of the motor 11 can be stopped to make the current zero while the braking state is maintained. The brake shoe holding member 13 has a brake shoe 14 attached thereto, and is displaced in the radial direction of the wheel 2 by the transmission unit 12. The brake shoe 14 is displaced together with the brake shoe holding member 13 and is pressed against the tread 2A of the wheel 2. The transmission unit 12 is provided with a pressing force sensor 15. The pressing force sensor 15 detects the pressing force of the brake shoe 14 from the reaction force acting on the transmission unit 12, and outputs the detected force to the control device 20. The motor 11 corresponds to an electric actuator. Furthermore, the wheel 2 corresponds to the friction target material, and the brake shoe 14 corresponds to the friction material.

[0022] The brake device 10 is controlled by a control device 20. The control device 20 may be configured as one or more processors that execute various processes according to a computer program (software). The processes executed by the control device 20, i.e., the processor, include an operation abnormality determination method. The operation abnormality determination method includes a state monitoring process described below. The control device 20 may be configured as a circuit including one or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), or a combination thereof, that executes at least a part of the various processes. The processor includes a CPU and memories such as a RAM and a ROM. The memory stores program codes or instructions configured to cause the CPU to execute the processes. The memory, i.e., the computer readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer. The program stored in the computer readable medium includes an operation abnormality determination program. The operation abnormality determination program causes the computer to execute an acquisition step, a calculation step, and a determination step.

[0023] The control device 20 controls the braking force based on a braking command from the vehicle control panel 5. The control device 20 includes a control unit 21 that controls the brake device 10. The control unit 21 drives and controls the motor 11 according to the required braking force. The control unit 21 acquires a brake command and a release command from the vehicle control panel 5. The brake command is a command to brake the wheel 2 by pressing the brake shoe 14 against the tread 2A of the wheel 2. The release command is a command to release the pressure of the brake shoe 14 against the tread 2A of the wheel 2. The vehicle control panel 5 outputs, for example, 1 to 7 notch brake signals and 8 release signals to the brake device 10 by a combination of 0 and 1 on three signal lines in response to an operation by the driver. The control unit 21 moves the brake shoe 14 in a direction approaching the tread 2A of the wheel 2 by rotating the motor 11 in the braking direction. Meanwhile, the control unit 21 rotates the motor 11 in the releasing direction opposite to the braking direction, thereby moving the brake shoe 14 in a direction away from the tread 2A of the wheel 2. During releasing, the control unit 21 controls the brake shoe 14 to move to a position a predetermined distance away from the position where it contacts the tread 2A of the wheel 2. By controlling in this way, it is possible to keep constant the distance and time from when the brake shoe 14 contacts the tread 2A of the wheel 2 until braking begins.

[0024] The control device 20 includes a drive information acquisition unit 22, a calculation unit 23, a judgment unit 24, and a storage unit 25. The drive information acquisition unit 22 acquires drive information of the motor 11. The drive information is the current value of the motor 11 and the rotation speed of the motor 11. The calculation unit 23 calculates a calculation value C, which is at least one of the movement distance D of the brake shoe 14 and the time T required for the brake shoe 14 to reach a predetermined position, based on the acquired drive information of the motor 11. The judgment unit 24 compares the calculation value C with a reference value S to judge an operation abnormality. An operation abnormality is a state in which the operation of the transmission unit 12, the brake shoe holding member 13, and the brake shoe 14 is different from normal due to a foreign object being caught between the brake shoe 14 and the tread surface 2A of the wheel 2 or due to a jam. When an operation abnormality occurs, the calculation value C becomes larger or smaller than the reference value S. The reference value S is at least one of the movement distance D and the time T required under normal conditions.

[0025] The current value of the motor 11 is different when the brake shoe 14 is free to contact the tread 2A of the wheel 2 and when the brake shoe 14 is pressed against the tread 2A of the wheel 2. There is also control where the current value during free running is smaller than the current value during pressing, and control where the current value during free running is larger than the current value during pressing.

[0026] The brake device 10 includes a notification unit 26. The notification unit 26 issues a notification when the determination unit 24 determines that an operation abnormality has occurred. The notification unit 26 is a speaker that emits sound, a light that turns on, a display unit, or the like. The notification unit 26 is preferably provided on the vehicle control panel 5 so that the driver can notice it. In addition, the notification unit 26 is preferably installed near the brake device 10 so that an operator can notice it during a start-of-days inspection, a finish-of-days inspection, or the like.

[0027] The brake control by the control device 20 includes control so that the gradient of the deceleration is constant regardless of the target deceleration shown in FIG. 2, and control so that the time required to reach the target deceleration is constant as shown in FIG. 3. In the control so that the gradient of the deceleration is constant, the pressing time tT differs depending on the target deceleration. For this reason, the judgment unit 24 compares the reference value S and the calculated value C under the same conditions. Also, in the control so that the time required to reach the target deceleration is constant, the rotation speed of the motor 11 differs depending on the target deceleration. For this reason, the judgment unit 24 compares the reference value S and the calculated value C under the same conditions. The same conditions refer to the same control and the same target deceleration.

[0028] Next, referring to Fig. 4, a change in the current value of the motor 11 during braking will be described. The control unit 21 controls the current value during free running so that it is smaller than the current value during pressing. Fig. 4 shows the current value of the motor 11 when the control unit 21 acquires a brake command and performs braking. More specifically, this is the current value of one of the U, V, and W phases of a three-phase brushless DC motor. Note that while Fig. 4 shows only the brake command, the control unit 21 acquires a release command when there is no brake command.

[0029] As shown in FIG. 4, when the control unit 21 acquires a brake command, a current flows to the motor 11 after a delay of a start time t0A. The start time t0A is a short time. When a current flows to the motor 11, the brake shoe 14 moves toward the tread 2A of the wheel 2 via the transmission unit 12. When the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object, the movement of the brake shoe 14 is restricted, so that the current value exceeds the contact threshold value L0. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the current value reaches the contact threshold value L0. The free running time t0 is the time from when a brake command is issued until the current value reaches the contact threshold value L0. The actual free running time t0B is the time from when a current flows to the motor 11 until the current value reaches the contact threshold value L0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). When the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, the current value becomes larger than that during free running, reaches the brake threshold L1 corresponding to a predetermined braking force, and further reaches the target threshold LT corresponding to the target braking force. The current value does not increase when it reaches the target threshold LT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when it reaches the brake threshold L1 is defined as a first time t1. The time from when it reaches the brake threshold L1 to when it reaches the target threshold LT is defined as a second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The pressing force detected by the pressing force sensor 15 increases when the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, and stops increasing when the current value reaches the target threshold LT. After that, the pressing force of the brake shoe holding member 13 is held by the holding mechanism 12A, so the power supply to the motor 11 is stopped.

[0030] Next, referring to Fig. 5, the change in the current value of the motor 11 during release will be described. Although the control unit 21 performs control so that the current value during free running is smaller than the current value during pressing during braking, the control unit 21 performs control so that the current value during free running is larger than the current value during pressing during release. Fig. 5 shows the current value of the motor 11 when the control unit 21 acquires a release command, the brake command is removed, and braking is released. Note that while Fig. 5 only shows the brake command, the control unit 21 acquires the release command when there is no brake command.

[0031] As shown in FIG. 5, while the brake command is being acquired, the motor 11 is stopped from being energized. When the control unit 21 acquires the release command, current flows through the motor 11 after a delay of a start time t0A'. The start time t0A' is a short time. When the current flows through the motor 11, the holding force of the holding mechanism 12A is first released, and the pressing force becomes zero. The time from when the current flows through the motor 11 until the pressing force reaches zero is the holding force release time tB. When the holding force of the holding mechanism 12A is released, the brake shoe 14 moves in a direction away from the tread 2A of the wheel 2 via the transmission unit 12. The current value becomes larger than during the holding force release time tB for releasing the holding force of the holding mechanism 12A. The control unit 21 stops the motor 11 after a predetermined pullback time tC has elapsed from the time when the current flows through the motor 11. The pullback time tC is the time when the braking force is released and the brake shoe 14 moves to the original position. The control unit 21 may move the brake shoe 14 at a moving speed obtained by converting a predetermined number of rotations of the motor 11 into a stroke of the brake shoe 14 after obtaining the release command, and the product of this moving speed and a predetermined time. In this way, it becomes unnecessary to detect the pressing force. The control unit 21 may also stop the motor 11 after a predetermined time has elapsed from the time when the current value became large. In this way, it becomes unnecessary to detect the pressing force. The control unit 21 may also stop the motor 11 after a predetermined time has elapsed from the time when the pressing force becomes zero.

[0032] The calculation unit 23 calculates at least one of the following first calculated value C1 to fifth calculated value C5. The first calculated value C1 is at least one of the first travel distance D1 and the first required time T1 when the brake shoe 14 reaches the contact threshold value L0, which is the current value when the brake shoe 14 comes into contact with the tread 2A of the wheel 2 or a foreign object. The first required time T1 is the free running time t0, and the first travel distance D1 is the product of the travel speed, which is obtained by converting the rotation speed of the motor 11 into the stroke of the brake shoe 14, and the free running time t0. If the brake shoe 14 comes into contact with a foreign object or if a jam occurs in the transmission part 12, the free running time t0 becomes shorter than the first reference value S1. The first reference value S1 is the first travel distance D1 and the first required time T1 under normal conditions.

[0033] The second calculated value C2 is at least one of the second travel distance D2 and the second required time T2 when the brake threshold L1, which is a current value corresponding to a predetermined braking force, is reached. The second required time T2 is the first time t1 or the sum of the free running time t0 and the first time t1. The second travel distance D2 is the product of the moving speed of the brake shoe 14 obtained by converting the rotation speed of the motor 11 and the first time t1, or the product of the moving speed of the brake shoe 14 obtained by converting the rotation speed of the motor 11 and the sum of the free running time t0 and the first time t1. The second reference value S2 is the second required time T2 and the second travel distance D2 under normal conditions.

[0034] The third calculated value C3 is at least one of the third travel distance D3 and the third required time T3 when the current reaches the target threshold LT, which is a current value corresponding to the target braking force. The third required time T3 is the second time t2 or the sum of the free running time t0, the first time t1, and the second time t2. The third travel distance D3 is the product of the moving speed of the brake shoe 14 obtained by converting the rotation speed of the motor 11 and the second time t2, or the product of the moving speed of the brake shoe 14 obtained by converting the rotation speed of the motor 11 and the sum of the free running time t0, the first time t1, and the second time t2. The third reference value S3 is the third required time T3 and the third travel distance D3 in a normal state.

[0035] The fourth calculated value C4 is a fourth required time T4 from when the current value reaches the contact threshold value L0, which is the current value when the brake shoe 14 comes into contact with the tread 2A of the wheel 2 or a foreign object, to when the current value reaches the brake threshold value L1, which is the current value corresponding to a predetermined braking force. The fourth required time T4 is the first time t1. The fourth reference value S4 is the first time t1 under normal conditions.

[0036] The fifth calculated value C5 is a fifth required time T5 from when a brake command is obtained until current flows through the motor 11 and the motor 11 starts to operate. The fifth required time T5 is the start-up time t0A when braking or the start-up time t0A' when releasing the brake. When the electric circuit of the motor 11 deteriorates, the responsiveness decreases and the start-up times t0A and t0A' may become longer. The fifth reference value S5 is the respective start-up times t0A and t0A' under normal conditions.

[0037] Furthermore, the calculation unit 23 may calculate at least one of the following sixth calculated value C6 and seventh calculated value C7, in addition to the above first calculated value C1 to fifth calculated value C5. The sixth calculated value C6 is a holding force release time tB, which is the time from when the current flows to the motor 11 until the pressing force reaches zero. If the holding mechanism 12A becomes stuck, the holding force release time tB may become longer. The sixth reference value S6 is the holding force release time tB under normal conditions.

[0038] The seventh calculated value C7 is a pullback time tC, which is a predetermined time from the time when the current flows to the motor 11. The pullback time tC may be shortened if a jam occurs in the transmission unit 12. The seventh reference value S7 is the pullback time tC in a normal state.

[0039] The calculation unit 23 calculated the first calculated value C1 to the fifth calculated value C5 using the time when the brake command was acquired as the starting point. However, the calculation unit 23 may calculate the first calculated value C1 to the fifth calculated value C5 using the time when the motor 11 was started as the starting point. The calculation unit 23 stores the calculated calculation value C in the storage unit 25. The determination unit 24 uses the calculation value C stored in the storage unit 25 as the reference value S. For example, the calculation value C when the brake device 10 is fitted to the railway vehicle or when a final inspection is performed is set as the reference value S.

[0040] The determination unit 24 determines that an operation abnormality has occurred when a determination condition is met. The determination condition is that the difference between the calculated value C and the reference value S is equal to or greater than a predetermined value. When using a plurality of calculated values ​​C among the first calculated value C1 to the seventh calculated value C7, the determination unit 24 may determine that an operation abnormality has occurred when the number of calculated values ​​C whose difference from the reference value S is equal to or greater than a predetermined value is equal to or greater than a specified number. Note that the maximum value of the specified number is the number of calculated values ​​C.

[0041] Next, the procedure of the state monitoring process by the control device 20 will be described with reference to Fig. 6. Fig. 6 shows the process of monitoring the operation abnormality of the braking device 10 when the braking device 10 is activated.

[0042] First, the control device 20 acquires driving information (step S1). That is, the driving information acquisition unit 22 acquires a current value of the motor 11, and acquires the number of rotations of the motor 11 when calculating the moving distance D. Note that step S1 corresponds to an acquisition step.

[0043] Next, the control device 20 calculates the calculated value C (step S2). That is, the calculation unit 23 calculates the calculated value C, which is at least one of the moving distance D of the brake shoe 14 and the time T required for the brake shoe 14 to reach a predetermined position, based on the acquired driving information of the motor 11. Note that step S2 corresponds to a calculation step.

[0044] Next, the control device 20 stores the calculated value C (step S3). That is, the calculation unit 23 stores the calculated calculated value C in the storage unit 25. When the control unit 21 determines the calculated calculated value C as the reference value S, it stores the calculated calculated value C in the storage unit 25 as the reference value S.

[0045] Next, the control device 20 judges whether or not the judgment condition for the operational abnormality is satisfied (step S4). That is, the judgment unit 24 compares the calculated value C with the reference value S to judge whether or not the difference between the calculated value C and the reference value S is equal to or greater than a predetermined value. Then, when the judgment unit 24 judges that the judgment condition for the operational abnormality is not satisfied (step S4: NO), the process ends. Note that step S4 corresponds to a judgment step.

[0046] On the other hand, when the determination unit 24 determines that the determination condition for the operation abnormality is satisfied (step S4: YES), it outputs "operation abnormality" (step S5). That is, the control unit 21 notifies the "operation abnormality" by the notification unit 26. Therefore, the operation abnormality of the brake device 10 can be grasped based on the information acquired from the brake device 10.

[0047] Next, a change in the current value of the motor 11 during braking will be described with reference to Fig. 7. The control unit 21 controls the current value during free running so that it is greater than the current value during pressing. Fig. 7 shows the current value of the motor 11 when the control unit 21 obtains a brake command and performs braking. More specifically, this is the current value of one of the U, V, and W phases of a three-phase brushless DC motor.

[0048] As shown in FIG. 7, when the control unit 21 acquires a brake command, a current flows to the motor 11 after a delay of a start time t0A. The start time t0A is a short time. When a current flows to the motor 11, the brake shoe 14 moves toward the tread 2A of the wheel 2 via the transmission unit 12. Since the current value during free running is larger than the current value during pressing, it is not possible to know from the current value that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object. Therefore, the pressing force sensor 15 detects the pressing force, and the control unit 21 knows that the movement of the brake shoe 14 has been restricted. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the pressing force is detected. The free running time t0 is the time from when a brake command is issued until the current value reaches the contact threshold value L0. The actual free running time t0B is the time from when the current flows until the current value reaches the contact threshold value L0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). The current value gradually increases, reaches the brake threshold L1 corresponding to a predetermined braking force, and then reaches the target threshold LT corresponding to the target braking force. The current value does not increase when it reaches the target threshold LT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when it reaches the brake threshold L1 is defined as the first time t1. The time from when it reaches the brake threshold L1 to when it reaches the target threshold LT is defined as the second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The pressing force detected by the pressing force sensor 15 increases when the brake shoe 14 presses the tread 2A of the wheel 2 or a foreign object, and stops increasing when the current value reaches the target threshold LT. Thereafter, the pressing force of the brake shoe holding member 13 is held by the holding mechanism 12A, so that the supply of electricity to the motor 11 is stopped.

[0049] Next, referring to Fig. 8, the change in the current value of the motor 11 during release will be described. Because there is a holding mechanism 12A, the control unit 21 controls the current value during free running during release so that it is smaller than the current value during pressing. Fig. 8 is a diagram similar to Fig. 5, and shows the current value of the motor 11 when the control unit 21 acquires a release command, the brake command is removed, and braking is released. As it is similar to Fig. 5, the explanation will be omitted.

[0050] Even if the current value changes as shown in Figures 7 and 8 above, by performing a state monitoring process using the control device 20, it is possible to grasp an operational abnormality of the brake device 10 based on the information acquired from the brake device 10.

[0051] Next, the effects of the first embodiment will be described. (1-1) The judgment unit 24 compares at least one of the travel distance D and the required time T of the brake shoe 14 calculated by the calculation unit 23 based on the drive information acquired by the drive information acquisition unit 22 with a reference value S to judge an operational abnormality. Therefore, the operational abnormality of the brake device 10 can be grasped based on the information acquired from the brake device 10.

[0052] (1-2) In the case of control in which the current value during free running is greater than the current value during pressing during braking, when the brake shoe 14 comes into contact with the tread 2A of the wheel 2 or a foreign object, the movement of the brake shoe 14 stops, causing a large change in the current value. For this reason, it is possible to easily grasp an operational abnormality of the braking device 10 by comparing the first calculated value C1 when the brake shoe 14 comes into contact with the tread 2A of the wheel 2 or a foreign object.

[0053] (1-3) In the case of control in which the current value during free running is greater than the current value during pressing during braking, the current value rises as the movement of the brake shoe 14 stops after the brake shoe 14 comes into contact with the tread 2A of the wheel 2 or a foreign object. For this reason, by comparing the second calculated value C2 when a predetermined braking force is applied, it is possible to know whether the operational abnormality of the brake device 10 is stiff or not.

[0054] (1-4) In the control where the current value during free running is greater than the current value during pressing during braking, the current value rises as the movement of the brake shoe 14 stops after the brake shoe 14 comes into contact with the tread 2A of the wheel 2 or a foreign object. For this reason, by comparing the third calculated value C3 when the target braking force is applied, it can be determined whether the operational abnormality of the brake device 10 is stiff or not.

[0055] (1-5) The time T required for the brake shoe 14 to reach a predetermined braking force after contact is the same even if a foreign object is trapped. Therefore, when the time T is shorter than the reference value S, there is a possibility of a jam, and the details of the operational abnormality of the brake device 10 can be grasped.

[0056] (1-6) By comparing the time T required for the current to flow from when a brake command is obtained until the motor 11 starts, it is possible to grasp the deterioration of parts from the delayed response of the electronic circuit.

[0057] (1-7) By comparing at least one of the travel distance D and the required time T under normal conditions with the reference value S, it is possible to grasp an operational abnormality of the brake device 10. (1-8) Since the start of the motor 11 can be detected by the flow of current through the motor 11, it is possible to determine whether an operational abnormality of the brake device 10 exists without obtaining a brake command.

[0058] (1-9) There are those that control the deceleration rate so that the slope of the deceleration rate is constant regardless of the target deceleration rate, and those that control the time required to reach the target deceleration rate so that the time required to reach the target deceleration rate is constant. Therefore, by the determination unit 24 comparing the reference value S and the calculated value C under the same conditions, it is possible to accurately determine whether the brake device 10 is operating abnormally.

[0059] Second embodiment A second embodiment of the brake device will be described below with reference to Figures 9 and 10. The brake device of this embodiment differs from the first embodiment in that the current value of the main power supply is used as the current value of the motor. The following description will focus on the differences from the first embodiment.

[0060] 9 and 10 show the current value of the main power supply that supplies power to the motor 11. The control unit 21 controls the current value during idling to be smaller than the current value during pressing. FIG. 9 shows the current value of the main power supply when the control unit 21 obtains a brake command and performs braking. As shown in FIG. 9, when the control unit 21 obtains a brake command, a current flows from the main power supply with a delay of a start time t0A. The start time t0A is a short time. When a current flows from the main power supply, the motor 11 drives the brake shoe 14 to move toward the tread 2A of the wheel 2 via the transmission unit 12. When the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object, the current value becomes equal to or greater than the contact threshold value P0. Note that the current value that becomes equal to or greater than the contact threshold value P0 immediately after the current flows from the main power supply is ignored. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the current value becomes equal to or greater than the contact threshold value P0. The free running time t0 is the time from when the brake command is issued until the current value becomes equal to or greater than the contact threshold value P0. The actual free running time t0B is the time from when the current flows until the current value reaches the contact threshold value P0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). When the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, the current value becomes equal to or exceeds the brake threshold value P1 corresponding to a predetermined braking force, and further reaches the target threshold value PT corresponding to the target braking force. The current value does not increase when it reaches the target threshold value PT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when it reaches the brake threshold value P1 is defined as the first time t1. The time from when it reaches the brake threshold value P1 to when it reaches the target threshold value PT is defined as the second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The pressing force detected by the pressing force sensor 15 increases when the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, and stops increasing when the current value reaches the target threshold value PT. Thereafter, the pressing force of the brake shoe holding member 13 is held by the holding mechanism 12A, so that the supply of electricity to the motor 11 is stopped.

[0061] FIG. 10 shows the current value of the main power supply when the control unit 21 acquires a release command and releases the brake when the brake command is removed. As shown in FIG. 10, when the control unit 21 acquires a release command, current flows from the main power supply with a delay of a start time t0A'. The start time t0A' is a short time. When the current flows from the main power supply, the holding force of the holding mechanism 12A is first released and the pressing force becomes zero. The time from when the current flows from the main power supply to when the pressing force reaches zero is the holding force release time tB. When the holding force of the holding mechanism 12A is released, the brake shoe 14 moves in a direction away from the tread 2A of the wheel 2 via the transmission unit 12. The current value becomes larger than during the holding force release time tB when the holding force of the holding mechanism 12A is released. The control unit 21 turns off the main power supply after a predetermined pullback time tC has elapsed from the time when the current flows from the main power supply. The pullback time tC is the time when the braking force is released and the brake shoe 14 moves to the original position. The control unit 21 may move the brake shoe 14 at a moving speed obtained by converting a predetermined number of rotations of the motor 11 into a stroke of the brake shoe 14 after obtaining the release command, and the product of this moving speed and a predetermined time. In this way, it becomes unnecessary to detect the pressing force. The control unit 21 may also stop the supply of electricity from the main power supply after a predetermined time has elapsed from the time when the current value became large. In this way, it becomes unnecessary to detect the pressing force. The control unit 21 may also stop the supply of electricity from the main power supply after a predetermined time has elapsed from the time when the pressing force becomes zero.

[0062] The calculation unit 23 calculates at least one of the first calculated value C1 to the seventh calculated value C7, as in the first embodiment. The judgment unit 24 judges that an operation abnormality has occurred when a judgment condition is met. The judgment condition is that the difference between the calculated value C and the reference value S is equal to or greater than a predetermined value. When using a plurality of calculated values ​​C among the first calculated value C1 to the seventh calculated value C7, the judgment unit 24 may judge that an operation abnormality has occurred when the number of calculated values ​​C whose difference from the reference value S is equal to or greater than a predetermined value is equal to or greater than a specified number. Note that the maximum value of the specified number is the number of calculated values ​​C.

[0063] The control device 20 performs the state monitoring process similarly to the first embodiment, using the current value of the main power supply as the current value of the motor 11 and the first calculated value C1 to the seventh calculated value C7 as the calculated value C. Thus, it is possible to grasp an operational abnormality of the brake device 10 based on information acquired from the brake device 10.

[0064] Next, a change in the current value of the main power supply during braking will be described with reference to Fig. 11. The control unit 21 controls the current value during free running to be larger than the current value during pressing. Fig. 11 shows the current value of the main power supply when the control unit 21 obtains a brake command and performs braking.

[0065] As shown in FIG. 11, when the control unit 21 acquires a brake command, a current flows to the motor 11 after a delay of a start time t0A. The start time t0A is a short time. When a current flows to the motor 11, the brake shoe 14 moves toward the tread 2A of the wheel 2 via the transmission unit 12. Since the current value during free running is larger than the current value during pressing, it is not possible to know from the current value that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object. Therefore, the pressing force sensor 15 detects the pressing force, and the control unit 21 knows that the movement of the brake shoe 14 has been restricted. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the pressing force is detected. The free running time t0 is the time from when a brake command is issued until the current value reaches the contact threshold value P0. The actual free running time t0B is the time from when a current flows from the main power source until the current value reaches the contact threshold value P0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). The current value gradually increases, reaches the brake threshold value P1 corresponding to a predetermined braking force, and further reaches the target threshold value PT corresponding to the target braking force. The current value does not increase when it reaches the target threshold value PT. The time from when the brake shoe 14 contacts the tread surface 2A of the wheel 2 or a foreign object to when it reaches the brake threshold value P1 is defined as the first time t1. The time from when it reaches the brake threshold value P1 to when it reaches the target threshold value PT is defined as the second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The pressing force detected by the pressing force sensor 15 increases when the brake shoe 14 presses the tread surface 2A of the wheel 2 or a foreign object, and stops increasing when the current value reaches the target threshold value PT. Thereafter, the pressing force of the brake shoe holding member 13 is held by the holding mechanism 12A, so that the supply of electricity from the main power source is stopped.

[0066] Next, referring to Fig. 12, the change in the current value of the motor 11 during release will be described. Even if the control unit 21 controls the current value during free running during braking to be greater than the current value during pressing, the control unit 21 controls the current value during free running during release to be smaller than the current value during pressing because of the holding mechanism 12A. Fig. 12 is a diagram similar to Fig. 10, and shows the current value of the motor 11 when the control unit 21 acquires a release command, the brake command is removed, and braking is released. As it is similar to Fig. 10, the explanation will be omitted.

[0067] Even if the current value changes as shown in Figures 11 and 12 above, by performing a state monitoring process using the control device 20, it is possible to grasp an operational abnormality of the brake device 10 based on the information obtained from the brake device 10.

[0068] Next, the effects of the second embodiment will be described. In addition to the effects (1-1) to (1-9) of the first embodiment, the following effects are achieved. (2-1) By using the current value of the main power supply as the current value of the motor 11, an operational abnormality of the brake device 10 can be detected based on information acquired from the brake device 10.

[0069] Third embodiment A third embodiment of the brake device will be described below with reference to Figs. 13 to 16. The brake device of this embodiment differs from the first embodiment in that it does not include a holding mechanism 12A. The following mainly describes the differences from the first embodiment. Since the brake device 10 does not include a holding mechanism 12A, it maintains the braking state by continuing to pass a current while it has acquired a braking command.

[0070] Changes in the current value of motor 11 during braking will be described with reference to Fig. 13. Control unit 21 controls motor 11 so that the current value during free running is smaller than the current value during pressing. Fig. 13 shows the current value of motor 11 when control unit 21 obtains a brake command and performs braking. More specifically, this is the current value of one of the U, V, and W phases of a three-phase brushless DC motor.

[0071] As shown in FIG. 13, when the control unit 21 acquires a brake command, a current flows to the motor 11 after a delay of a start time t0A. The start time t0A is a short time. When a current flows to the motor 11, the brake shoe 14 moves toward the tread 2A of the wheel 2 via the transmission unit 12. When the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object, the movement of the brake shoe 14 is restricted, so that the current value exceeds the contact threshold value L0. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the current value reaches the contact threshold value L0. The free running time t0 is the time from when a brake command is issued until the current value reaches the contact threshold value L0. The actual free running time t0B is the time from when a current flows to the motor 11 until the current value reaches the contact threshold value L0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). When the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, the current value becomes larger than when the vehicle is free running, reaches a brake threshold L1 corresponding to a predetermined braking force, and further reaches a target threshold LT corresponding to the target braking force. The current value does not increase after reaching the target threshold LT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when the brake threshold L1 is reached is defined as a first time t1. The time from when the brake threshold L1 is reached to when the target threshold LT is reached is defined as a second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The control unit 21 continues to flow a current of the target threshold LT while it is acquiring a brake command.

[0072] Changes in the current value of motor 11 during release will be described with reference to Fig. 14. Control unit 21 controls the current value during free running to be smaller than the current value during pressing. Fig. 14 shows the current value of motor 11 when control unit 21 acquires a release command, the brake command is removed and braking is released.

[0073] As shown in FIG. 14, the current of the target threshold value LT continues to flow while the brake command is being acquired. When the control unit 21 acquires the release command, the current of the motor 11 is reduced after a delay of a start time t0A'. The start time t0A' is a short time. The current value decreases because the pressure of the brake shoe 14 against the tread surface 2A of the wheel 2 is released. The time from when the current of the motor 11 is reduced to when the pressing force reaches zero is the holding force release time tB. The current value becomes smaller than during the holding force release time tB. The control unit 21 stops the motor 11 after a pullback time tC, which is a predetermined time from the time when the current of the motor 11 is reduced, has elapsed. The pullback time tC is the time when the braking force is released and the brake shoe 14 moves to the original position. The control unit 21 may move the brake shoe 14 at a moving speed obtained by converting a predetermined number of revolutions of the motor 11 into a stroke of the brake shoe 14 and a predetermined time after acquiring the release command. In this way, it is not necessary to detect the pressing force. The control unit 21 may also stop the motor 11 after a predetermined time has elapsed since the time when the current value became small. In this way, it becomes unnecessary to detect the pressing force. The control unit 21 may also stop the motor 11 after a predetermined time has elapsed since the time when the pressing force became zero.

[0074] The calculation unit 23 calculates at least one of the first calculated value C1 to the seventh calculated value C7, as in the first embodiment. The judgment unit 24 judges that an operation abnormality has occurred when a judgment condition is met. The judgment condition is that the difference between the calculated value C and the reference value S is equal to or greater than a predetermined value. When using a plurality of calculated values ​​C among the first calculated value C1 to the seventh calculated value C7, the judgment unit 24 may judge that an operation abnormality has occurred when the number of calculated values ​​C whose difference from the reference value S is equal to or greater than a predetermined value is equal to or greater than a specified number. Note that the maximum value of the specified number is the number of calculated values ​​C.

[0075] The control device 20 performs the state monitoring process in the same manner as in the first embodiment, using the current value of the motor 11 to set the first calculated value C1 to the seventh calculated value C7 as the calculated value C. Thus, the operation abnormality of the brake device 10 can be grasped based on the information acquired from the brake device 10.

[0076] Next, a change in the current value of the motor 11 during braking will be described with reference to Fig. 15. The control unit 21 controls the current value during free running to be larger than the current value during pressing. Fig. 15 shows the current value of the motor 11 when the control unit 21 obtains a brake command and performs braking. More specifically, this is the current value of one of the U, V, and W phases of a three-phase brushless DC motor.

[0077] As shown in FIG. 15, when the control unit 21 acquires a brake command, a current flows to the motor 11 after a delay of a start time t0A. The start time t0A is a short time. When a current flows to the motor 11, the brake shoe 14 moves toward the tread 2A of the wheel 2 via the transmission unit 12. Since the current value during free running is larger than the current value during pressing, it is not possible to know from the current value that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object. Therefore, the pressing force sensor 15 detects the pressing force, and the control unit 21 knows that the movement of the brake shoe 14 has been restricted. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the pressing force is detected. The free running time t0 is the time from when the brake command is issued until the current value reaches the contact threshold value L0. The actual free running time t0B is the time from when the current flows until the current value reaches the contact threshold value L0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). The current value gradually increases after reaching the contact threshold L0, reaches the brake threshold L1 corresponding to a predetermined braking force, and then reaches the target threshold LT corresponding to the target braking force. The current value does not increase after reaching the target threshold LT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when it reaches the brake threshold L1 is defined as the first time t1. The time from when it reaches the brake threshold L1 to when it reaches the target threshold LT is defined as the second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The control unit 21 continues to flow the current of the target threshold LT while it is acquiring a brake command.

[0078] Next, the change in the current value of the motor 11 during release will be described with reference to Fig. 16. The control unit 21 controls the current value during free running to be greater than the current value during pressing. Fig. 16 shows the current value of the motor 11 when the control unit 21 acquires a release command, the brake command is removed and braking is released.

[0079] As shown in FIG. 16, while the brake command is being acquired, the current of the target threshold value LT continues to flow. When the control unit 21 acquires the release command, the current of the motor 11 increases after a delay of a start time t0A'. The start time t0A' is a short time. The current value decreases because the pressure of the brake shoe 14 against the tread surface 2A of the wheel 2 is released. The time from when the current of the motor 11 increases until the pressing force reaches zero is the holding force release time tB. The current value becomes smaller than during the holding force release time tB. The control unit 21 stops the motor 11 after a pullback time tC, which is a predetermined time from the time when the current of the motor 11 is increased, has elapsed. The pullback time tC is the time when the braking force is released and the brake shoe 14 moves to the original position. The control unit 21 may move the brake shoe 14 at a moving speed obtained by converting a predetermined number of revolutions of the motor 11 into a stroke of the brake shoe 14 and a predetermined time after acquiring the release command. In this way, it is not necessary to detect the pressing force. The control unit 21 may also stop the motor 11 after a predetermined time has elapsed since the time when the current value became large. In this way, it is not necessary to detect the pressing force. The control unit 21 may also stop the motor 11 after a predetermined time has elapsed since the time when the pressing force became zero.

[0080] The calculation unit 23 calculates at least one of the first calculated value C1 to the seventh calculated value C7, as in the first embodiment. The judgment unit 24 judges that an operation abnormality has occurred when a judgment condition is met. The judgment condition is that the difference between the calculated value C and the reference value S is equal to or greater than a predetermined value. When using a plurality of calculated values ​​C among the first calculated value C1 to the seventh calculated value C7, the judgment unit 24 may judge that an operation abnormality has occurred when the number of calculated values ​​C whose difference from the reference value S is equal to or greater than a predetermined value is equal to or greater than a specified number. Note that the maximum value of the specified number is the number of calculated values ​​C.

[0081] The control device 20 performs the state monitoring process similarly to the first embodiment, using the current value of the main power supply as the current value of the motor 11 and the first calculated value C1 to the seventh calculated value C7 as the calculated value C. Thus, it is possible to grasp an operational abnormality of the brake device 10 based on information acquired from the brake device 10.

[0082] Even if the current value changes as shown in Figures 15 and 16 above, by performing a state monitoring process using the control device 20, it is possible to grasp an operational abnormality of the brake device 10 based on the information acquired from the brake device 10.

[0083] Next, the effects of the third embodiment will be described. In addition to the effects (1-1) to (1-9) of the first embodiment, the following effects are achieved. (3-1) In a brake device 10 that does not include a holding mechanism 12A, an operational abnormality of the brake device 10 can be detected based on information acquired from the brake device 10.

[0084] (Fourth embodiment) A fourth embodiment of the brake device will be described below with reference to Figs. 17 to 20. The brake device of this embodiment differs from the second embodiment in that the brake device does not include a holding mechanism 12A, which uses the current value of the main power supply as the current value of the motor. The following mainly describes the differences from the second embodiment. Note that since the brake device 10 does not include a holding mechanism 12A, the brake device 10 maintains the braking state by continuing to flow current while it has acquired a braking command.

[0085] Changes in the current value of the main power supply during braking will be described with reference to Fig. 17. The control unit 21 controls the current value during free running to be smaller than the current value during pressing. Fig. 17 shows the current value of the main power supply when the control unit 21 obtains a brake command and performs braking.

[0086] As shown in FIG. 17, when the control unit 21 acquires a brake command, a current flows from the main power supply after a delay of a start time t0A. The start time t0A is a short time. When a current flows from the main power supply, the motor 11 drives the brake shoe 14 to move toward the tread 2A of the wheel 2 via the transmission unit 12. When the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object, the current value becomes equal to or greater than the contact threshold value P0. Note that the current value that becomes equal to or greater than the contact threshold value P0 immediately after the current flows from the main power supply is ignored. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the current value becomes equal to or greater than the contact threshold value P0. The free running time t0 is the time from when a brake command is issued until the current value becomes equal to or greater than the contact threshold value P0. The actual free running time t0B is the time from when the current flows until the current value reaches the contact threshold value P0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). When the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, the current value becomes equal to or exceeds the brake threshold value P1 corresponding to a predetermined braking force, and further reaches the target threshold value PT corresponding to the target braking force. The current value does not increase when it reaches the target threshold value LT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when it reaches the brake threshold value P1 is defined as the first time t1. The time from when it reaches the brake threshold value P1 to when it reaches the target threshold value PT is defined as the second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The pressing force detected by the pressing force sensor 15 increases when the brake shoe 14 presses against the tread 2A of the wheel 2 or a foreign object, and stops increasing when the current value reaches the target threshold value LT. The control unit 21 continues to apply a current of the target threshold value LT while the brake command is being received.

[0087] Changes in the current value of the main power supply during release will be described with reference to Fig. 18. The control unit 21 controls the current value during free running to be smaller than the current value during pressing. Fig. 18 shows the current value of the main power supply when the control unit 21 acquires a release command, the brake command is removed and braking is released.

[0088] As shown in FIG. 18, while the brake command is being acquired, the current of the target threshold value PT continues to flow. When the control unit 21 acquires the release command, the current from the main power source decreases after a delay of a start time t0A'. The start time t0A' is a short time. The current value decreases because the pressure of the brake shoe 14 against the tread surface 2A of the wheel 2 is released. The time from when the current from the main power source decreases until the pressing force reaches zero is the holding force release time tB. The control unit 21 stops the current from the main power source after a pullback time tC, which is a predetermined time from the time when the current from the main power source decreases, has elapsed. The pullback time tC is the time when the braking force is released and the brake shoe 14 moves to the original position. Note that the control unit 21 may move the brake shoe 14 by the product of a moving speed obtained by converting a predetermined number of revolutions of the motor 11 into a stroke of the brake shoe 14 and a predetermined time after acquiring the release command. In this way, it is not necessary to detect the pressing force. The control unit 21 may also stop the supply of electricity from the main power supply after a predetermined time has elapsed since the time when the current value became large. In this way, it is not necessary to detect the pressing force. The control unit 21 may also stop the supply of electricity from the main power supply after a predetermined time has elapsed since the time when the pressing force became zero.

[0089] The calculation unit 23 calculates at least one of the first calculated value C1 to the seventh calculated value C7, as in the first embodiment. The judgment unit 24 judges that an operation abnormality has occurred when a judgment condition is met. The judgment condition is that the difference between the calculated value C and the reference value S is equal to or greater than a predetermined value. When using a plurality of calculated values ​​C among the first calculated value C1 to the seventh calculated value C7, the judgment unit 24 may judge that an operation abnormality has occurred when the number of calculated values ​​C whose difference from the reference value S is equal to or greater than a predetermined value is equal to or greater than a specified number. Note that the maximum value of the specified number is the number of calculated values ​​C.

[0090] The control device 20 performs the state monitoring process similarly to the first embodiment, using the current value of the main power supply as the current value of the motor 11 and the first calculated value C1 to the seventh calculated value C7 as the calculated value C. Thus, it is possible to grasp an operational abnormality of the brake device 10 based on information acquired from the brake device 10.

[0091] Next, a change in the current value of the main power supply during braking will be described with reference to Fig. 19. The control unit 21 controls the current value during free running to be larger than the current value during pressing. Fig. 19 shows the current value of the main power supply when the control unit 21 obtains a brake command and performs braking.

[0092] As shown in FIG. 19, when the control unit 21 acquires a brake command, a current flows to the motor 11 after a delay of a start time t0A. The start time t0A is a short time. When a current flows to the motor 11, the brake shoe 14 moves toward the tread 2A of the wheel 2 via the transmission unit 12. Since the current value during free running is larger than the current value during pressing, it is not possible to know from the current value that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object. Therefore, the pressing force sensor 15 detects the pressing force, and the control unit 21 knows that the movement of the brake shoe 14 has been restricted. The calculation unit 23 determines that the brake shoe 14 has contacted the tread 2A of the wheel 2 or a foreign object when the pressing force is detected. The free running time t0 is the time from when a brake command is issued until the current value reaches the contact threshold value P0. The actual free running time t0B is the time from when the current flows until the current value reaches the contact threshold value P0. Therefore, the free running time t0 is the sum of the start time t0A and the actual free running time t0B (t0=t0A+t0B). The current value gradually increases, reaches the brake threshold P1 corresponding to a predetermined braking force, and further reaches the target threshold PT corresponding to the target braking force. The current value does not increase when it reaches the target threshold PT. The time from when the brake shoe 14 contacts the tread 2A of the wheel 2 or a foreign object to when it reaches the brake threshold P1 is defined as the first time t1. The time from when it reaches the brake threshold P1 to when it reaches the target threshold PT is defined as the second time t2. The sum of the first time t1 and the second time t2 is the pressing time tT (tT=t1+t2). The pressing force detected by the pressing force sensor 15 increases when the brake shoe 14 presses the tread 2A of the wheel 2 or a foreign object, and stops increasing when the current value reaches the target threshold PT. The control unit 21 continues to pass the current of the target threshold LT while acquiring the brake command.

[0093] Next, the change in the current value of the main power supply during release will be described with reference to Fig. 20. The control unit 21 controls the current value during free running during release so that it is greater than the current value during pressing. Fig. 20 shows the current value of the main power supply when the control unit 21 acquires a release command, the brake command is removed and braking is released.

[0094] As shown in FIG. 20, while the brake command is being acquired, the current of the target threshold value LT continues to flow. When the control unit 21 acquires the release command, the current from the main power source increases after a delay of a start time t0A'. The start time t0A' is a short time. The time from when the current from the main power source increases until the pressing force reaches zero is the holding force release time tB. The control unit 21 stops the current from the main power source after a pullback time tC, which is a predetermined time, has elapsed from the time when the current from the main power source increased. The pullback time tC is the time when the braking force is released and the brake shoe 14 moves to the original position. The control unit 21 may move the brake shoe 14 by the product of a moving speed obtained by converting a predetermined number of revolutions of the motor 11 into a stroke of the brake shoe 14 and a predetermined time after acquiring the release command. In this way, it is not necessary to detect the pressing force. The control unit 21 may also stop the current from the main power source after a predetermined time has elapsed from the time when the current value becomes large. In this way, it is not necessary to detect the pressing force. Furthermore, the control unit 21 may stop the supply of electricity from the main power source when a predetermined time has elapsed since the time when the pressing force became zero.

[0095] Even if the current value changes as shown in Figures 19 and 20 above, by performing a state monitoring process using the control device 20, it is possible to grasp an operational abnormality of the brake device 10 based on the information acquired from the brake device 10.

[0096] Next, the effects of the fourth embodiment will be described. In addition to the effects (1-1) to (1-9) of the first embodiment, the following effects are achieved. (4-1) In a brake device 10 that does not have a holding mechanism 12A, the current value of the main power supply can be used as the current value of the motor 11, and operational abnormalities of the brake device 10 can be detected based on information obtained from the brake device 10.

[0097] Fifth embodiment Hereinafter, a fifth embodiment of the brake device will be described with reference to Fig. 21. This embodiment differs from the first to fourth embodiments in that the brake device is a disc brake device. Below, the differences from the first to fourth embodiments will be mainly described.

[0098] As shown in FIG. 21, the brake device 30 is a disc brake device that generates a braking force by pressing brake pads 34A, 34B against a disc 3 that rotates integrally with a wheel 2 of a railway vehicle. The brake device 30 includes a rotary motor 31 and is driven by the motor 31. The brake device 30 includes a transmission unit 32 that transmits the driving force of the motor 31 to the brake pads 34A, 34B, and a left arm 33A and a right arm 33B. The transmission unit 32 displaces the left arm 33A and the right arm 33B by the driving force of the motor 31. The transmission unit 32 is provided with a holding mechanism 32A. The holding mechanism 32A holds the pressing force of the left arm 33A and the right arm 33B even when the driving of the motor 31 is stopped. The holding mechanism 32A uses a one-way clutch or the like that mechanically holds the positions of the left arm 33A and the right arm 33B. The holding mechanism 32A releases the holding force when rotated in the releasing direction. In the brake device 30 equipped with the holding mechanism 32A, the current can be set to zero by stopping the driving of the motor 31 while maintaining the braking state. A brake pad 34A is attached to the left arm 33A, and a brake pad 34B is attached to the right arm 33B. The left arm 33A and the right arm 33B are displaced in a direction perpendicular to the side surface 3A of the disk 3 by the transmission unit 32. The brake pads 34A and 34B are displaced together with the left arm 33A and the right arm 33B, and pressed against the side surface 3A of the disk 3. A pressing force sensor 35 is provided on the transmission unit 32. The pressing force sensor 35 detects the pressing force of the brake pads 34A and 34B from the reaction force applied to the transmission unit 32, and outputs it to the control device 20. The motor 31 corresponds to an electric actuator. The disk 3 is a rotating body and corresponds to the friction material, and the brake pads 34A and 34B correspond to the friction material. The wheel 2 may be the friction material instead of the disk 3.

[0099] The braking device 30 is controlled by the control device 20 in the same manner as in the first to fourth embodiments. The control device 20 controls the braking force based on a braking command from the vehicle control panel 5. The control device 20 includes a control unit 21 that controls the braking device 30. The control unit 21 drives and controls the motor 11 according to the required braking force. The control unit 21 acquires a brake command and a release command from the vehicle control panel 5. The brake command is a command to brake the wheel 2 by pressing the brake pads 34A, 34B against the side surface 3A of the disk 3. The release command is a command to release the pressing of the brake pads 34A, 34B against the side surface 3A of the disk 3. The vehicle control panel 5 outputs, for example, 1 to 7 notch brake signals and 8 release signal signals to the braking device 30 by a combination of 0 and 1 on three signal lines in response to an operation by the driver. The control unit 21 rotates the motor 11 in the braking direction to move the brake pads 34A, 34B in a direction approaching the side surface 3A of the disk 3. Meanwhile, the control unit 21 rotates the motor 11 in a releasing direction opposite to the braking direction, thereby moving the brake pads 34A, 34B in a direction away from the side surface 3A of the disk 3. During releasing, the control unit 21 controls the brake pads 34A, 34B to move to a position a predetermined distance away from the position where they contact the side surface 3A of the disk 3. By controlling in this manner, it is possible to make constant the distance and time from when the brake pads 34A, 34B contact the side surface 3A of the disk 3 until braking begins.

[0100] The control device 20 includes a drive information acquisition unit 22, a calculation unit 23, a determination unit 24, and a storage unit 25. The drive information acquisition unit 22 acquires drive information of the motor 31. The drive information is the current value of the motor 31 and the number of revolutions of the motor 31. The calculation unit 23 calculates a calculated value C, which is at least one of the moving distance D of the brake pads 34A, 34B and the time T required for the brake pads 34A, 34B to reach a predetermined position, based on the acquired drive information of the motor 31. The determination unit 24 compares the calculated value C with a reference value S to determine an operation abnormality. An operation abnormality is a state in which a foreign object is caught between the brake pads 34A, 34B and the side surface 3A of the disk 3, or a locking occurs, causing the operation of the transmission unit 32, the left arm 33A and the right arm 33B, and the brake pads 34A, 34B to be different from normal. When an operation abnormality occurs, the calculated value C becomes larger or smaller than the reference value S. The reference value S is at least one of the moving distance D and the required time T under normal circumstances.

[0101] As in the first to fourth embodiments, the control device 20 calculates at least one of the first calculated value C1 to the seventh calculated value C7 from the current value of the motor 11 as the calculated value C, and determines whether or not there is an operational abnormality in the brake device 30 by comparing the calculated value C with the reference value S. Thus, the operational abnormality of the brake device 30 can be grasped based on information acquired from the brake device 30.

[0102] Next, the effects of the fifth embodiment will be described. In addition to the effects (1-1) to (1-9) of the first embodiment, (2-1) of the second embodiment, (3-1) of the third embodiment, and (4-1) of the fourth embodiment, the following effects are achieved. (5-1) Even in the case of a disc brake device, an operational abnormality in the brake device 30 can be detected based on information acquired from the brake device 30, similarly to the first to fourth embodiments.

[0103] (Other embodiments) The above-described embodiments may be modified as follows: The above-described embodiments and the following modifications may be combined with each other to the extent that no technical contradiction occurs.

[0104] In the first and third embodiments, at least one of the first calculated value C1 to the seventh calculated value C7 is calculated as the calculated value C to determine whether or not there is an operational abnormality in the brake devices 10, 30. However, only the calculated value C used to determine whether or not there is an operational abnormality in the brake device 30 may be calculated.

[0105] In each of the above embodiments, the reference value S is at least one of the normal travel distance D and the required time T. However, the reference value S may be at least one of the past travel distance D and the required time T.

[0106] In the above embodiments, the reference value S is set to at least one of the moving distance D and the required time T under normal conditions. However, the reference value S may be set to at least one of the moving distance D and the required time T of the friction material of another brake device in the same train.

[0107] In the above embodiments, the operational abnormality of the brake device is determined based on the driving information of the brake device during braking. However, the operational abnormality of the brake device may be determined based on the driving information of the brake device during release. For example, the activation time t0A', the holding force release time tB, and the pullback time tC may be the calculated value C, and the reference value S may be the normal or past activation time t0A', the holding force release time tB, and the pullback time tC.

[0108] In the above embodiments, the current value of the electric actuator is used as the drive information. However, time-series information indicating the load of the electric actuator, such as the torque or rotation speed of the electric actuator, may be used as the drive information.

[0109] In each of the above-described embodiments, the brake device 10, 30 is provided with the notification unit 26 that notifies the driver of an operational abnormality in the brake device 10, 30. However, the notification unit 26 may be omitted. In the above embodiments, the friction material is driven via a transmission unit using the rotary motor 11, 31. However, the friction material may be driven via a transmission unit using a direct-acting actuator or a linear actuator.

[0110] In each of the above embodiments, if a product is made up of multiple objects, the multiple objects may be integrated, and conversely, if a product is made up of a single object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the product is configured to achieve the object of the invention.

[0111] In each of the above embodiments, where multiple functions are provided in a distributed manner, some or all of the multiple functions may be provided in an integrated manner, and conversely, where multiple functions are provided in an integrated manner, some or all of the multiple functions may be provided in a distributed manner. Regardless of whether the functions are integrated or distributed, it is sufficient that the configuration is such that the object of the invention can be achieved. [Explanation of symbols]

[0112] 2...Wheel (frictional material) 2A…Tread 3...Disc (friction material) 3A…Side 5…Vehicle control panel 10...Brake device 11…Motor 12...Transmission section 12A…Retention mechanism 13...Bracelet holding member 14... Brake shoe (friction material) 15...Pressing force sensor 20...Control device 21...Control unit 22...Drive information acquisition unit 23...Calculation section 24…Judgment section 25...Storage section 26…Information Department 30...Brake device 31…Motor 32...Transmission section 32A…Retention mechanism 33A…Left arm 33B…Right arm 34A…Brake pads (friction material) 34B…Brake pads (friction material) 35...Pressing force sensor

Claims

1. A braking device that brakes a wheel by driving a friction material that is pressed against a friction target material, which is either a wheel or a rotating body that rotates integrally with the wheel, by an electric actuator, comprising: an acquisition unit that acquires driving information of the electric actuator; a calculation unit that calculates a calculated value of at least one of a moving distance of the friction material and a time required for the friction material to reach a predetermined position based on the acquired drive information; A determination unit that compares the calculated value with a reference value to determine an operational abnormality. Brake device.

2. The drive information is a current value of the electric actuator, The calculated value is at least one of the moving distance and the required time when the current value reaches the value when the friction material comes into contact with the friction target material or the foreign object.

2. The braking device according to claim 1.

3. The drive information is a current value of the electric actuator, The calculated value is at least one of the travel distance and the required time when a current value corresponding to a predetermined braking force is reached.

2. The braking device according to claim 1.

4. The drive information is a current value of the electric actuator, The calculated value is at least one of the travel distance and the required time when the current value corresponds to the target brake force.

2. The braking device according to claim 1.

5. The drive information is a current value of the electric actuator, The calculated value is the required time from when the current value when the friction material comes into contact with the friction target material or a foreign object to when the current value corresponds to a predetermined braking force.

2. The braking device according to claim 1.

6. A braking device for braking a wheel by driving a friction material pressed against a friction target material, which is either a wheel or a rotating body rotating integrally with the wheel, by an electric actuator, comprising: An acquisition unit that acquires a current value of the electric actuator; a calculation unit that calculates a required value from when a brake command is acquired based on the acquired current value until a current flows through the electric actuator and the actuator is started; A determination unit that compares the calculated value with a reference value to determine an operational abnormality. Brake device.

7. The start point of the travel distance and the required time is the time when the electric actuator is started. A brake device according to any one of claims 1 to 4.

8. The reference value is at least one of the travel distance and the required time in a normal state or in the past. A brake device according to any one of claims 1 to 7.

9. A plurality of brake devices are provided within the same train of rail vehicles, The reference value is at least one of the travel distance and the required time of the friction material of another brake device in the same train. A brake device according to any one of claims 1 to 7.

10. The determination unit compares the braking command with the reference value under the same conditions when the braking control is performed with a constant deceleration gradient of the braking device. A brake device according to any one of claims 1 to 9.

11. A method for determining an operational abnormality of a brake device that brakes a wheel by driving a friction material that is pressed against a friction target material, which is either a wheel or a rotating body that rotates integrally with the wheel, by an electric actuator, comprising: an acquisition step of acquiring driving information of the electric actuator; a calculation step of calculating a calculated value of at least one of a moving distance of the friction material and a time required for the friction material to reach a predetermined position based on the acquired drive information; A determination step of comparing the calculated value with a reference value to determine an operational abnormality. How to determine abnormal operation.

12. 1. A program for determining an operational abnormality of a brake device that brakes a wheel by driving a friction material that is pressed against a friction target material, which is either a wheel or a rotating body that rotates integrally with the wheel, by an electric actuator, comprising: On the computer, an acquisition step of acquiring driving information of the electric actuator; a calculation step of calculating a calculated value that is at least one of a moving distance of the friction material and a required time for the friction material to move based on the acquired driving information; A determination step of comparing the calculated value with a reference value to determine an operational abnormality. Anomaly detection program.

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