Brake control systems for industrial vehicles

Abstract

To provide a brake control device for an industrial vehicle, which can supply power to a brake unit during an operation of a cut-off switch without adding an exclusive component requiring a component cost and an installation space.SOLUTION: A brake control device 100 for an industrial vehicle comprises: a contactor 5 including a main contact 5a provided between a battery 4 and an inverter 8 to switch between a conduction state and a cut-off state and a coil 5d for driving the main contact 5a; a cut-off switch 6 that can cut off power supplied to the coil 5d so as to switch the contactor 5 to the cut-off state; a current sensor 7 that detects the power supplied to the coil 5d; and a controller 10 that controls the inverter 8. The controller 10 and an electromagnetic brake 3 receive power supplied from a circuit unit 9 between the contactor 5 and the inverter 8. The controller 10 controls the inverter 8 so as to cause a motor 2 to perform regenerative braking when cutting-off of power supplied from the battery 4 to the coil 5d is detected.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a braking control device for an industrial vehicle.

Background Art

[0002] Conventionally, in order to generate braking torque with a servo motor, a brake control device provided with a regenerative resistor for forming a path of the current generated by the servo motor is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technical field of industrial vehicles, measures against the occurrence of sudden braking due to the interruption of power supply to a braking unit when an emergency stop switch for stopping a running industrial vehicle is operated are being studied. However, the above conventional technology has a problem in that a dedicated regenerative resistor and an electromagnetic contactor for the above measures are additionally required, resulting in an increase in component costs and installation space.

[0005] An object of the present invention is to provide a braking control device for an industrial vehicle that enables power supply to a braking unit when an emergency stop switch is operated without adding dedicated components that require component costs and installation space.

Means for Solving the Problems

[0006] One aspect of the present invention is a braking control device for an industrial vehicle that controls the braking unit of an industrial vehicle, which comprises a motor, a braking unit that releases the braking of the motor by supplying power, a power supply unit capable of receiving regenerative power generated by the regenerative braking of the motor, and an inverter that supplies power to the motor and the power supply unit from each other. The braking control device for an industrial vehicle comprises a switch unit provided between the power supply unit and the inverter, which includes a main contact and a coil that drives the main contact, and in response to the power supply from the power supply unit, the coil drives the main contact to switch between a conductive state and a disconnected state, a disconnection switch capable of disconnecting the power supply from the power supply unit to the coil so as to switch the switch unit to a disconnected state, a detection unit that detects the power supply from the power supply unit to the coil, and a control unit that controls the inverter based on the detection result of the detection unit. The control unit and the braking unit are powered by a circuit portion between the switch unit and the inverter, and the control unit controls the inverter to cause the motor to perform regenerative braking when it detects that the power supply from the power supply unit to the coil has been disconnected.

[0007] In a braking control device for an industrial vehicle according to one aspect of the present invention, when the cutoff switch is operated and the power supply from the power supply unit to the coil is cut off, the switch unit enters a cutoff state. Based on the detection result of the detection unit, when the cutoff of the power supply from the power supply unit to the coil is detected, the control unit controls the inverter to perform regenerative braking on the motor. At this time, since the switch unit has been switched from a conductive state to a cutoff state, the regenerative power from the motor is supplied to the control unit and the braking unit from the circuit between the switch unit and the inverter. Therefore, power can be supplied to the braking unit when the cutoff switch is operated without requiring the addition of dedicated parts that would incur additional component costs and installation space.

[0008] In one embodiment, the control unit and the braking unit may be connected in parallel to the motor with respect to the power supply unit when the switch unit is in a conductive state, and in series with the motor when the switch unit is in a disconnected state. In this case, the circuit configuration can be switched by utilizing the switching between the conductive and disconnected states of the switch unit. [Effects of the Invention]

[0009] According to one aspect of the present invention, power can be supplied to the braking unit when the cutoff switch is operated without requiring the addition of dedicated parts that incur component costs and require installation space. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic block diagram illustrating a circuit configuration when the switch unit is in a conductive state in a braking control device for an industrial vehicle according to one embodiment. [Figure 2] This is a schematic block diagram illustrating a circuit configuration when the switch unit is in the off state in a braking control device for an industrial vehicle according to one embodiment. [Figure 3] This is a flowchart showing an example of controller processing. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

[0012] Figure 1 is a schematic block diagram illustrating a circuit configuration when the switch unit is in a conductive state in a braking control device for an industrial vehicle according to one embodiment. The braking control device 100 for an industrial vehicle according to this embodiment is a control device that controls the electromagnetic brake (braking unit) 3 of an industrial vehicle 1. An example of an industrial vehicle 1 on which the braking control device 100 for an industrial vehicle is mounted is an electric forklift.

[0013] As shown in Figure 1, the industrial vehicle 1 and the braking control device 100 for the industrial vehicle include a motor 2, an electromagnetic brake 3, a battery (power supply unit) 4, a contactor (switch unit) 5, a cutoff switch 6, a current sensor (detection unit) 7, an inverter 8, a circuit unit 9, a controller (control unit) 10, and an accelerator pedal 11.

[0014] Motor 2 is a motor generator for driving the industrial vehicle 1. Motor 2 is, for example, a three-phase AC rotary motor. Motor 2 generates driving force in response to the power supply from battery 4. During regenerative braking of the industrial vehicle 1, motor 2 generates electricity in response to the rotation of the drive wheels, producing regenerative power. The industrial vehicle 1 is configured to transmit the driving force generated by motor 2 to the drive wheels.

[0015] The electromagnetic brake 3 is a braking device used, for example, as a parking brake when an industrial vehicle 1 is parked. The electromagnetic brake 3 is provided to be able to brake the motor 2, which is a motor generator for driving. The electromagnetic brake 3 releases the brake on the motor 2 when power is supplied. The electromagnetic brake 3 brakes the motor 2 when power is no longer supplied. Therefore, for example, if power is no longer supplied to the electromagnetic brake 3 while the industrial vehicle 1 is in motion, the industrial vehicle 1 may be subjected to sudden braking.

[0016] Battery 4 is a power source that outputs DC power. Battery 4 can be charged by DC power input. Battery 4 is capable of receiving regenerative power generated by the regenerative braking of motor 2. For example, a secondary battery such as a lead-acid battery or a lithium-ion battery can be used as Battery 4. The positive electrode 4a of Battery 4 is connected to one end 5b of the main contact 5a of contactor 5 and to one end 6a of the cutoff switch 6.

[0017] The contactor 5 is a switch located between the battery 4 and the inverter 8. The contactor 5 switches the electrical connection and disconnection of the battery 4 as the main power source in response to the operation of, for example, the main switch (e.g., key switch) of the industrial vehicle 1. The contactor 5 is composed of a main contact 5a and a coil 5d that drives the main contact 5a. The contactor 5 switches between a conductive state and a disconnected state in response to the power supply from the battery 4 to the coil 5d. The conductive state is when the main contact 5a is closed, and the battery 4 and the inverter 8 are electrically connected. The disconnected state is when the main contact 5a is open, and the battery 4 and the inverter 8 are electrically disconnected.

[0018] The main contact 5a is a movable contact for switching the electrical connection and disconnection of the battery 4 as the main power source. One end 5b of the main contact 5a is connected to the positive electrode 4a of the battery 4. The other end 5c of the main contact 5a is connected to the first end 9a of the circuit portion 9 between the contactor 5 and the inverter 8.

[0019] The circuit portion 9 is a part of the circuit constituting the braking control device 100 of the industrial vehicle, and connects the contactor 5, the inverter 8, and the controller 10. In the example of FIG. 1, the circuit portion 9 has a wiring 9c extending from the first end 9a to the second end 9b, and a wiring 9e branching from the wiring 9c and extending to the third end 9d.

[0020] The coil 5d is excited or demagnetized in response to the power supply from the battery 4, and drives to open and close the main contact 5a of the contactor 5. One end 5e of the coil 5d is connected to the other end 6b of the cutoff switch 6. A part between one end 5e of the coil 5d and the other end 6b of the cutoff switch 6 may pass through the inside of the controller 10. The other end 5f of the coil 5d is connected to the negative electrode 4b side of the battery 4 (for example, the body ground portion of the industrial vehicle 1). A part between the other end 5f of the coil 5d and the negative electrode 4b side of the battery 4 may pass through the inside of the controller 10.

[0021] The cutoff switch 6 is operated to stop the industrial vehicle 1 in motion in an emergency. The cutoff switch 6 is, for example, an emergency stop button. The cutoff switch 6 is installed, for example, at a position where the driver can operate it in the driver's seat of the industrial vehicle 1. The cutoff switch 6 is provided between the battery 4 and one end 5e of the coil 5d. The cutoff switch 6 electrically connects the battery 4 and the coil 5d in a non-operated state. The cutoff switch 6 electrically disconnects the battery 4 and the coil 5d in an operated state. That is, the cutoff switch 6 can cut off the power supply from the battery 4 to the coil 5d so as to switch the contactor 5 to the cutoff state when operated.

[0022] According to the configuration as described above, in the contactor 5, when the cutoff switch 6 is not operated, power is supplied from the battery 4 to the coil 5d, so the main contact 5a is driven to close by the coil 5d. Therefore, when the cutoff switch 6 is not operated, the contactor 5 is in a conductive state that electrically connects the battery 4 and the inverter 8. On the other hand, in the contactor 5, when the cutoff switch 6 is operated, the power supply from the battery 4 to the coil 5d is cut off, so the main contact 5a that is no longer driven by the coil 5d opens. Therefore, when the cutoff switch 6 is operated, the contactor 5 is in a cutoff state that electrically disconnects the battery 4 and the inverter 8.

[0023] An electric current sensor 7 is provided between one end 5e of the coil 5d and the other end 6b of the cutoff switch 6. The electric current sensor 7 is a detection unit that detects the power supply from the battery 4 to the coil 5d. The electric current sensor 7 is provided, for example, at a portion passing through the inside of the controller 10 between one end 5e of the coil 5d and the other end 6b of the cutoff switch 6. The electric current sensor 7 detects the current flowing from the battery 4 to the coil 5d and transmits the detected current information to the controller 10.

[0024] The inverter 8 converts and supplies power between the motor 2 and the battery 4. The inverter 8 converts DC power from the battery 4 into AC power to supply to the motor 2. The inverter 8 is a known three-phase inverter, for example, comprising IGBTs. The DC positive terminal 8a of the inverter 8 is connected to the second terminal 9b of the wiring 9c of the circuit section 9. The DC negative terminal 8b of the inverter 8 is connected to the negative terminal 4b side of the battery 4 (for example, the vehicle body ground). The AC terminal 8c of the inverter 8 is connected to the motor 2. The dashed lines L1 to L14 in Figures 1 and 2 indicate the flow of current, with the current flowing towards the tip of the arrow. As shown by the dashed line L1 in Figure 1, the inverter 8 is supplied with DC power from the battery 4 via the contactor 5 when the cutoff switch 6 is not operated. As shown by the dashed line L2 in Figure 1, the inverter 8 converts the supplied DC power into AC power and outputs it to the motor 2. In this case, the path from motor 2 to battery 4 is the path shown by dashed lines L3 to L5 in Figure 1, forming a closed circuit.

[0025] A DC / DC converter may be interposed between the contactor 5 and the inverter 8 (for example, on wiring 9c). The DC / DC converter, for example, boosts the voltage of the DC power from the battery 4 to the inverter 8. In this case, the inverter 8 converts the DC power from the DC / DC converter into AC power.

[0026] The inverter 8 converts the regenerative power from the motor 2 into DC power. When the cutoff switch 6 is not operated, the inverter 8 converts the regenerative power from the motor 2 into DC power and outputs the converted DC power to the battery 4 via the wiring 9c of the circuit section 9 and the contactor 5. In this case, a closed circuit is formed such that the current flows in the opposite direction to the dashed lines L1 to L5 in Figure 1.

[0027] Controller 10 is an electronic control unit that controls the electromagnetic brake 3 of the industrial vehicle 1. Controller 10 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), CAN (Controller Area Network) communication circuit, etc. Controller 10 implements various functions, for example, by loading a program stored in ROM into RAM and executing the program loaded into RAM with the CPU. Controller 10 may be composed of multiple electronic control units.

[0028] The controller 10 may control the inverter 8 based on the detection result of the amount of operation of the accelerator pedal 11. The accelerator pedal 11 may include a sensor for detecting the amount of operation. For example, if the cutoff switch 6 is not operated, the controller 10 controls the inverter 8 to output AC power to the motor 2 according to the amount of operation of the accelerator pedal 11.

[0029] The positive terminal 10a of the power terminal of the controller 10 is connected to the third terminal 9d of the wiring 9e of the circuit section 9. The negative terminal 10b of the power terminal of the controller 10 is connected to the negative terminal 4b side of the battery 4 (for example, the vehicle body ground). The controller 10 operates when power is supplied to the positive terminal 10a from the wiring 9e of the circuit section 9, as shown by the dashed line L6 in Figure 1. The output terminal 10c of the controller 10 is connected to the electromagnetic brake 3. As shown by the dashed lines L7 and L8 in Figure 1, the controller 10 can supply a portion of the power supplied to the positive terminal 10a to the electromagnetic brake 3.

[0030] Figure 2 is a schematic block diagram illustrating a circuit configuration in an industrial vehicle braking control device according to one embodiment, when the switch unit is in the off state. Figure 2 illustrates a circuit configuration where the off switch 6 is operated and the contactor 5 is switched to the off state.

[0031] The controller 10 detects the interruption of power supply from the battery 4 to the coil 5d based on the detection result of the current sensor 7. For example, the controller 10 detects the interruption of power supply from the battery 4 to the coil 5d when it detects that the current has stopped flowing from the battery 4 to the coil 5d due to the operation of the cutoff switch 6, based on the current information detected by the current sensor 7. For example, the controller 10 detects the interruption of power supply from the battery 4 to the coil 5d when the current value from the battery 4 to the coil 5d falls below a predetermined cutoff threshold. The cutoff threshold may be, for example, 0A, or a current value slightly greater than 0A.

[0032] The controller 10 controls the inverter 8 to regenerate braking the motor 2 when it detects that the power supply from the battery 4 to the coil 5d has been interrupted. The controller 10 may also control the inverter 8 so that the regenerative power of the motor 2 is equal to or greater than a predetermined regenerative power at the time of interruption when it detects that the power supply from the battery 4 to the coil 5d has been interrupted due to the operation of the cutoff switch 6. The regenerative power at the time of interruption is the regenerative power generated by the motor 2 when the cutoff switch 6 is operated. The regenerative power at the time of interruption can be set to a power level that is greater than the power required to operate the controller 10 and the electromagnetic brake 3 by a predetermined margin. The predetermined margin is a power margin that is sufficient to prevent the operation of the controller 10 and the electromagnetic brake 3 from stopping midway, even if fluctuations in regenerative power occur, for example.

[0033] Incidentally, when the cutoff switch 6 is operated, there is a short period of time before the main contact 5a opens and the contactor 5 becomes closed. During this short period, power is supplied from the battery 4 to the controller 10. Therefore, during this short period, the controller 10 sends a control signal to control the inverter 8 to perform regenerative braking on the motor 2. More precisely, the communication cycle of the CAN communication circuit between the controller 10 and the inverter 8 may also be considered. For example, when the controller 10 detects that the power supply from the battery 4 to the coil 5d has been cut off, it may send a control signal to control the inverter 8 to perform regenerative braking on the motor 2 asynchronously with respect to the communication cycle of the CAN communication circuit (without waiting until the next communication cycle). When the controller 10 detects that the power supply from the battery 4 to the coil 5d has been cut off, it may change the communication cycle to a shorter one than when the power supply cutoff has not been detected and send a control signal to control the inverter 8 to perform regenerative braking on the motor 2. Alternatively, by increasing the size of the energy storage element such as a capacitor included in the controller 10, it may be possible to send a control signal to the inverter 8 for a predetermined time after the contactor 5 becomes closed.

[0034] When the inverter 8 detects a disruption in the power supply from the battery 4 to the coil 5d, it converts the regenerative power from the motor 2 into DC power in accordance with a control signal from the controller 10. The regenerative power converted into DC power by the inverter 8 is supplied to the controller 10 and the electromagnetic brake 3 via the wiring 9e of the circuit section 9, without passing through the contactor 5, as shown by the dashed lines L9 to L11 in Figure 2, because the cutoff switch 6 has been operated and the contactor 5 has been switched to the cutoff state. Specifically, as shown by the dashed line L9 in Figure 2, the regenerative power from the motor 2 is supplied to the inverter 8 and converted into DC power by the inverter 8. Because the cutoff switch 6 has been operated, the DC power from the inverter 8 is supplied to the positive terminal 10a of the controller 10 via the wiring 9e of the circuit section 9, without passing through the contactor 5, as shown by the dashed line L10 in Figure 2. As shown by the dashed lines L11 and L12 in Figure 2, a portion of the DC power supplied to the controller 10 is supplied to the electromagnetic brake 3. Because the cutoff switch 6 is operated, a closed circuit is not formed on the battery 4 side, so the DC power returning from the electromagnetic brake 3 does not pass through the negative terminal 4b of the battery 4, as shown by the dashed line L13 in Figure 2, but returns from the negative terminal 10b of the controller 10 to the negative terminal 8b on the DC side of the inverter 8. The power converted by the inverter 8 returns to the motor 2 from the AC side terminal 8c of the inverter 8, as shown by the dashed line L14 in Figure 2. In this way, when the cutoff switch 6 is operated, a closed circuit is formed in which the motor 2, inverter 8, controller 10, and electromagnetic brake 3 are connected in series, as shown by the dashed lines L9 to L14 in Figure 2.

[0035] Figure 3 is a flowchart illustrating an example of controller processing. The processing shown in the flowchart in Figure 3 is repeatedly executed at predetermined calculation cycles, for example, while the industrial vehicle 1 is in motion.

[0036] In S10, the controller 10 of the industrial vehicle's braking control device 100 acquires the detection result of the current sensor 7, which is the detection unit. For example, the controller 10 receives current information from the current sensor 7 regarding the current flowing from the battery 4 to the coil 5d, as detected by the current sensor 7.

[0037] In S11, the controller 10 determines whether or not it has detected a disruption in the power supply from the battery 4 to the coil 5d. For example, if the controller 10 detects that the current has stopped flowing from the battery 4 to the coil 5d due to the operation of the cutoff switch 6, it detects a disruption in the power supply from the battery 4 to the coil 5d.

[0038] If the controller 10 does not detect a disruption in the power supply from the battery 4 to the coil 5d (S11: NO), the controller 10 controls the inverter 8 in S12 according to the amount of operation of the accelerator pedal 11. For example, the controller 10 controls the inverter 8 to output AC power to the motor 2 according to the amount of operation of the accelerator pedal 11. After that, the controller 10 terminates the process shown in Figure 3.

[0039] On the other hand, if the controller 10 detects that the power supply from the battery 4 to the coil 5d has been interrupted (S11: YES), the controller 10 controls the inverter 8 in S13 to regenerate braking the motor 2. For example, the controller 10 controls the inverter 8 so that the regenerative power of the motor 2 is equal to or greater than a predetermined regenerative power at the time of interruption. After that, the controller 10 terminates the process shown in Figure 3.

[0040] With the industrial vehicle braking control device 100 configured as described above, when the cutoff switch 6 is operated and the power supply from the battery 4 to the coil 5d is cut off, the contactor 5 enters a cutoff state. Based on the detection result of the current sensor 7, when the cutoff of the power supply from the battery 4 to the coil 5d is detected, the controller 10 controls the inverter 8 to regenerate braking of the motor 2. At this time, since the contactor 5 has been switched from a conductive state to a cutoff state, the regenerative power from the motor 2 is supplied to the controller 10 and the electromagnetic brake 3 from the wiring 9e of the circuit section 9 between the contactor 5 and the inverter 8 (dashed lines L9, L10, L11). The industrial vehicle 1 decelerates and comes to a stop due to the regenerative braking of the motor 2. Regenerative power from the motor 2 can be supplied to the controller 10 and the electromagnetic brake 3 until the industrial vehicle 1 comes to a stop. Therefore, power can be supplied to the braking unit when the cutoff switch is operated without adding dedicated parts that require additional parts cost and installation space. Furthermore, since the addition of a regenerative resistor as a dedicated component is eliminated, power is not consumed by the regenerative resistor, which would otherwise reduce efficiency.

[0041] In the industrial vehicle braking control device 100, when the contactor 5 is conducting, the controller 10 and electromagnetic brake 3 are connected in parallel with the motor 2 to the battery 4, and when the contactor 5 is disconnected, the controller 10 and electromagnetic brake 3 are connected in series with the motor 2. Specifically, when the contactor 5 is conducting, as shown by dashed lines L1 and L6 in Figure 1, power from the battery 4 branches into wiring 9c and wiring 9e in the circuit section 9 and flows to the controller 10 and electromagnetic brake 3 and the motor 2, respectively. Current from the motor 2 and electromagnetic brake 3 returns to the battery 4 via paths that merge from dashed lines L3, L4 and L8 in Figure 1 to dashed line L5. That is, when the contactor 5 is conducting, the controller 10 and electromagnetic brake 3 are connected in parallel with the motor 2 to the battery 4 and powered from the circuit section 9 between the contactor 5 and the inverter 8. On the other hand, as shown in Figure 2, when the contactor 5 is in the closed state, the regenerative power from the motor 2, as shown by the dashed lines L9 to L11 in Figure 2, can pass through the wiring 9e of the circuit section 9 to the controller 10 and the electromagnetic brake 3 instead of passing through the contactor 5. The DC power returning from the electromagnetic brake 3, as shown by the dashed line L13 in Figure 2, does not pass through the negative terminal 4b of the battery 4, but returns from the negative terminal 10b of the controller 10 to the negative terminal 8b on the DC side of the inverter 8. The power converted by the inverter 8 returns to the motor 2 from the AC side terminal 8c of the inverter 8, as shown by the dashed line L14 in Figure 2. In other words, a closed circuit is formed in which the motor 2, inverter 8, controller 10, and electromagnetic brake 3 are connected in series, as shown by the dashed lines L9 to L14 in Figure 2. In this way, the circuit configuration can be switched by utilizing the switching between the conducting and closed states of the contactor 5.

[0042] [Differentiation] The present invention is not limited to the embodiments described above. The present invention can be implemented in various forms, including the embodiments described above, with various modifications and improvements based on the knowledge of those skilled in the art.

[0043] For example, in the above embodiment, the controller 10 and electromagnetic brake 3 were connected in parallel with the motor 2 to the battery 4 when the contactor 5 was conducting, and in series with the motor 2 when the contactor 5 was disconnected. However, the circuit configuration is not limited to this. In short, any circuit configuration is acceptable in which, when the contactor 5 is disconnected, regenerative power from the motor 2 is supplied to the controller 10 and electromagnetic brake 3 from the circuit section 9 between the contactor 5 and the inverter 8.

[0044] In the above embodiment, a battery 4, which is a secondary battery such as a lead-acid battery or lithium-ion battery, was shown as an example of a power supply unit, but the invention is not limited to this example. The power supply unit may be, for example, an electric double-layer capacitor. The power supply unit may include a fuel cell. The power supply unit may be a combination of an external power supply and a storage battery. The external power supply may be a DC power supply, or an AC power supply may be used by interposing an AC / DC converter.

[0045] In the above embodiment, an electromagnetic brake 3 was shown as an example of a braking unit, but the invention is not limited to this example. In short, it is sufficient that the braking of the motor 2 can be released by supplying power, and it may be a different braking device from the electromagnetic brake 3 used as a parking brake, for example.

[0046] In the above embodiment, a current sensor 7 was shown as an example of a detection unit for detecting power supply from the battery 4 to the coil 5d, but the invention is not limited to this example. For example, the detection unit may be a voltage sensor that detects the potential difference between the positive electrode 4a of the battery 4 and one end 5e of the coil 5d. Furthermore, the detection unit does not necessarily have to be provided in a portion that passes inside the controller 10 between one end 5e of the coil 5d and the other end 6b of the cutoff switch 6, as is the case with the current sensor 7.

[0047] In the above embodiment, a contactor 5 (electromagnetic contactor) was shown as an example of the switch section, but the invention is not limited to this example. For example, an electromagnetic switch (magnetic switch) may be used, which combines a thermal relay with the contactor 5.

[0048] In the above embodiment, an electric forklift was shown as the industrial vehicle 1 on which the industrial vehicle braking control device 100 is mounted, but the invention is not limited to this example. For example, the industrial vehicle may be other industrial vehicles such as towing vehicles or transport vehicles. The industrial vehicle may include a motor powered by a power supply unit and a braking unit that can release the motor's braking by supplying power, and may also be configured to use an engine in conjunction with the industrial vehicle. [Explanation of symbols]

[0049] 1...Industrial vehicle, 2...Motor, 3...Electromagnetic brake (braking unit), 4...Battery (power supply unit), 5...Contactor (switch unit), 5a...Main contact, 5d...Coil, 6...Cut-off switch, 7...Current sensor (detection unit), 8...Inverter, 9...Circuit section, 10...Controller (control unit), 100...Brake control device for industrial vehicles.

Claims

1. A braking control device for an industrial vehicle, comprising a motor for driving, a braking unit that releases the braking of the motor by supplying power, a power supply unit capable of receiving regenerative power generated by the regenerative braking of the motor, and an inverter that provides mutual power supply between the motor and the power supply unit, wherein the braking unit of the industrial vehicle is controlled by the braking control device for the industrial vehicle, A switch unit is provided between the power supply unit and the inverter, and includes a main contact and a coil for driving the main contact, wherein the coil drives the main contact in response to power supply from the power supply unit to switch between a conductive state and a disconnected state. A cutoff switch capable of cutting off the power supply from the power supply unit to the coil so as to switch the switch unit to the cutoff state, A detection unit for detecting the power supply from the power supply unit to the coil, A control unit that controls the inverter based on the detection result of the detection unit, Equipped with, The control unit and the braking unit are powered by the circuit between the switch unit and the inverter. The control unit controls the inverter to cause the motor to perform regenerative braking when it detects an interruption in the power supply from the power supply unit to the coil, in a braking control device for an industrial vehicle.

2. The control unit and the braking unit are, When the switch unit is in a conductive state, the motor is connected in parallel to the power supply unit. The braking control device for an industrial vehicle according to claim 1, wherein when the switch unit is in the off state, it is connected in series with the motor.

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