JP6304053B2 - Battery powered industrial vehicle - Google Patents

Description

  The present invention relates to a battery-powered industrial vehicle equipped with a battery.

  A battery-powered industrial vehicle that travels by driving a traveling motor is equipped with a battery for driving the traveling motor. Deterioration of the battery is promoted when the battery enters an overdischarge state where the remaining capacity is lower than a predetermined remaining capacity. For this reason, in battery-powered industrial vehicles, it is recommended to charge the battery before it reaches the overdischarged state. However, due to factors such as busy periods and forgetting to charge the battery, the battery is further overcharged. In some cases, the battery is maintained in an overdischarged state, such as being discharged or not being charged in an overdischarged state.

  Patent Document 1 describes a management method for collecting operating state data of a battery-type industrial vehicle in an external computer and managing the battery life based on the operating state data. From the operating state data, data related to the battery such as the battery discharge amount, the charge amount, and the overdischarge time can be obtained. The field engineer makes recommendations on the use of the battery from this data, thereby extending the battery life.

JP 2002-120999 A

Incidentally, in battery-powered industrial vehicles, further suppression of battery deterioration is desired.
An object of the present invention is to provide a battery-powered industrial vehicle that can suppress battery deterioration.

  A battery-powered industrial vehicle that solves the above problem is a battery-powered industrial vehicle that travels using a battery as a driving source, and a remaining capacity measuring member that measures the remaining capacity of the battery, and the remaining capacity of the battery is used for overdischarge determination. An overdischarge time integration unit that measures an integration time maintained below a threshold value, and a control unit that causes the notification unit to perform notification according to the remaining capacity of the battery, wherein the control unit integrates the overdischarge time integration When the accumulated time measured by the unit is less than the accumulation threshold, the notification unit performs a first notification when the remaining capacity of the battery becomes equal to or less than the overdischarge determination threshold, and the overdischarge time integration is performed. When the accumulated time measured by the unit is equal to or greater than the accumulated threshold, when the remaining capacity of the battery becomes equal to or less than the notification threshold, the notification unit performs a second notification, Excessive Is the value remaining capacity of the battery is larger than the electrostatic determination threshold.

  According to this, when the remaining capacity of the battery is equal to or less than the overdischarge determination threshold (hereinafter referred to as an overdischarge state), the first notification by the notification unit prompts the operator to charge and the battery is in the overdischarge state. It can suppress that it is maintained as it is. In addition, when the accumulated time during which the battery is maintained in the overdischarged state becomes equal to or greater than the accumulated threshold value, a second notification is given by the notification unit when the remaining battery capacity becomes equal to or less than the notification threshold value, and the battery is in the overdischarged state. The operator can be urged to charge before becoming. For this reason, it is suppressed that a battery will be in an overdischarge state, and deterioration of a battery can be suppressed.

About the said battery type industrial vehicle, it is preferable that said 1st alerting | reporting and said 2nd alerting | reporting are the alerting | reporting of a different aspect.
According to this, the operator can grasp whether the remaining capacity of the battery is equal to or less than the overdischarge determination threshold value or more than the overdischarge determination threshold value and less than the notification threshold value by notification in different modes.

  In the battery-powered industrial vehicle, it is preferable that the overdischarge time integration unit stops measuring the integration time when the remaining capacity of the battery exceeds the overdischarge determination threshold. According to this, the integration time during which the battery is maintained in the overdischarged state can be appropriately measured.

  About the said battery type industrial vehicle, it is preferable that the said alerting | reporting part is a display, and the said control part alert | reports by displaying the capacity | capacitance display of the said battery displayed on the said display with the display form different from normal. . According to this, the battery capacity display can be emphasized by displaying the battery capacity display in a display form different from the normal display form. Visual notification can be performed by emphasizing the battery capacity display.

  According to the present invention, battery deterioration can be suppressed.

The schematic side view which shows a forklift. The perspective view which shows the cab of a forklift. The schematic diagram which shows the display of a forklift. The block diagram which shows the structure of a forklift. The flowchart which shows the process which the controller of a forklift and a display unit perform. The schematic diagram which shows the capacity | capacitance display displayed on a display when the remaining capacity of a battery is below the threshold value for overdischarge determination. The schematic diagram which shows the capacity | capacitance display displayed on a display when the remaining capacity of a battery is more than the threshold value for overdischarge determination and below a notification threshold value.

Hereinafter, an embodiment of a battery-type industrial vehicle will be described.
As shown in FIGS. 1 and 2, drive wheels 12 are provided at the front lower part of the vehicle body 11 of the forklift 10 as a battery-powered industrial vehicle, and steering wheels 13 are provided at the rear lower part of the vehicle body 11. Yes. A cargo handling device 14 is provided at the front of the vehicle body 11. The cargo handling device 14 has a mast 15 erected on the front portion of the vehicle body 11. The mast 15 is provided with a pair of forks 17 via a lift bracket 16. The fork 17 is lifted and lowered together with the lift bracket 16 by driving a lift cylinder 18 connected to the mast 15. Further, the fork 17 is tilted together with the mast 15 by driving a tilt cylinder 19 connected to the mast 15.

  The vehicle body 11 is equipped with a traveling motor M1 that drives the driving wheels 12, a cargo handling motor M2 that drives the cargo handling device 14, and a battery 30. In the present embodiment, a lead battery is used as the battery 30. The traveling motor M1 and the cargo handling motor M2 are driven by electric power supplied from the battery 30. The forklift 10 travels by driving the drive wheels 12 using the battery 30 as a drive source.

  A cab 20 is provided in the center of the vehicle body 11. The driver's cab 20 is provided with a driving seat 21 on which a driver can sit. The cab 20 is provided with a cargo handling lever 22 for performing various operations such as raising and lowering operations and tilting operations of the cargo handling device 14. An accelerator pedal 23 is provided on the floor surface of the cab 20. In the cab 20, a handle column 24 is provided in front of the driving seat 21. A handle 25 is attached to the handle column 24. Further, the handle column 24 is provided with a display unit 31 having a display 32 for displaying various types of information related to the forklift 10.

  As shown in FIG. 3, in this embodiment, the capacity of the battery 30 is displayed on the display 32. In the present embodiment, the capacity display classification of the battery 30 is set to 10 levels. The display 32 displays ten symbols SY1 to SY10 set for each of the ten stages. The symbols SY1 to SY10 in each section correspond to the remaining capacity for 10%. Specifically, the symbol SY1 is 1% to 10%, the symbol SY2 is 11% to 20%, the symbol SY3 is 21% to 30%, the symbol SY4 is 31% to 40%, and the symbol SY5 is 41% to 50%. It corresponds to each remaining capacity. Symbol SY6 is 51% to 60%, Symbol SY7 is 61% to 70%, Symbol SY8 is 71% to 80%, Symbol SY9 is 81% to 90%, and Symbol SY10 is 91% to 100%. It corresponds to.

  Then, symbols SY <b> 1 to SY <b> 10 corresponding to the remaining capacity of the battery 30 are lit on the display 32. For example, as shown in FIG. 3, when the remaining capacity of the battery 30 is 81% to 90%, the symbols SY9 corresponding to 81% to 90% and the symbols SY1 to SY1 corresponding to less than the remaining capacity corresponding to the symbol SY9. Nine symbols SY1 to SY9 of SY8 are lit up. In FIG. 3, since the symbols SY <b> 1 to SY <b> 9 are lit, the operator can visually grasp from the screen display of the display 32 that the remaining capacity of the battery 30 is 81% to 90%. In the present embodiment, the remaining capacity of the battery 30 is monitored, and the number of symbols SY <b> 1 to SY <b> 10 that are lit and displayed sequentially is increased or decreased according to the increase or decrease of the remaining capacity of the battery 30. In the figure, a hatched symbol indicates “lighted display”, and a symbol not hatched indicates “off”.

  As shown in FIG. 4, the display unit 31 includes a display 32 on which various information is displayed, a timer 33 that measures time, a speaker 34, a program for performing various controls, data on past driving, and the like. Is stored, and a calculation unit 36 is provided.

  The display unit 31 is connected to a controller 40 that controls traveling and cargo handling. The controller 40 and the display unit 31 can communicate with each other via a CAN (Controller Area Network) or the like. The controller 40 includes a calculation unit 41 and a storage unit 42 in which programs for performing various controls are stored. A key switch 43 that is operated when starting and stopping the forklift 10 is connected to the controller 40. Then, the controller 40 starts the forklift 10 when the key switch 43 is turned on, and stops the forklift 10 when the key switch 43 is turned off.

  The battery 30 includes a current sensor 51 that measures the current of the battery 30 and outputs the current to the controller 40, a voltage sensor 52 that measures the voltage of the battery 30 and outputs the voltage to the controller 40, and measures and displays the temperature of the battery 30. A temperature sensor 53 that outputs to the unit 31 is provided. The battery 30 is connected to a charger (charging transformer) 54 to which an external power supply 55 is connected. When the external power supply 55 is connected to the charger 54, the battery 30 is charged by controlling the charger 54 by the controller 40.

  The controller 40 and the display unit 31 monitor the remaining capacity of the battery 30 and suppress the deterioration of the battery 30 by urging the operator to charge the battery 30 according to the remaining capacity of the battery 30. Regardless of whether the key switch 43 is on or off, the controller 40 and the display unit 31 perform the following processing at regular time intervals (for example, several tens of ms) using the power of the sub battery different from the battery 30 to thereby 30 monitoring is performed.

Hereinafter, processes performed by the controller 40 and the display unit 31 will be described together with actions.
As shown in FIG. 5, in step S10, the calculation unit 41 of the controller 40 measures the remaining capacity (charge rate) of the battery 30, and the process proceeds to step S11. The remaining capacity of the battery 30 is obtained from the current data of the battery 30 input from the current sensor 51, the voltage data of the battery 30 input from the voltage sensor 52, and the temperature data of the battery 30 input from the display unit 31. . Specifically, the remaining capacity of the battery 30 is measured by correcting the remaining capacity of the battery 30 obtained from the current data and voltage data of the battery 30 with the temperature data. Therefore, in this embodiment, the remaining capacity of the battery 30 is measured by the current sensor 51, the voltage sensor 52, the temperature sensor 53, the display unit 31, and the controller 40, and these function as a remaining capacity measuring member. In step S <b> 11, the controller 40 transmits the measured remaining capacity data to the display unit 31. The remaining capacity data may be digitized data indicating the remaining capacity, or data in which the remaining capacity is associated with the capacity display category. That is, any form of data may be used as long as the display unit 31 can display the capacity.

  In step S20, when receiving the remaining capacity data, the calculation unit 36 of the display unit 31 reflects the remaining capacity of the battery 30 on the capacity display of the display 32, and the process proceeds to step S21. In step S <b> 21, the display unit 31 determines whether or not the battery 30 is in an overdischarged state from data indicating the remaining capacity of the battery 30. Whether or not the battery 30 is in the overdischarge state is determined by whether or not the remaining capacity of the battery 30 is equal to or less than the overdischarge determination threshold value. When the remaining capacity of the battery 30 is equal to or less than the overdischarge determination threshold, the display unit 31 determines that the battery 30 is in an overdischarge state. When the remaining capacity of the battery 30 is greater than the overdischarge determination threshold, the display unit 31 determines that the battery 30 is not in an overdischarge state. This threshold value for overdischarge determination is set to a remaining capacity that promotes deterioration of the battery 30 due to an excessive decrease in the remaining capacity of the battery 30, and in this embodiment, 20% of the total capacity of the battery 30 (remaining capacity 20 %). The overdischarge determination threshold value is stored in the storage unit 35 of the display unit 31. If the determination result in step S21 is affirmative, that is, if the battery 30 is in an overdischarged state, the display unit 31 proceeds to step S22.

  In step S22, the calculation unit 36 of the display unit 31 starts measuring the time by the timer 33, thereby starting the measurement of the time during which the battery 30 is maintained in the overdischarged state, and shifts the processing to step S23. . Specifically, when the time measurement by the timer 33 has already been performed, the calculation unit 36 of the display unit 31 maintains the time measurement by the timer 33 and the time measurement by the timer 33 is performed. If not, the time measurement by the timer 33 is started. When the time measurement by the timer 33 is started, the time is measured continuously from the time measured in the past without resetting the time measured in the past. Thus, the accumulated time during which the battery 30 is maintained in the overdischarged state is measured by the timer 33. Therefore, the timer 33 functions as an overdischarge time integration unit.

  In step S23, the display unit 31 transmits the determination result of step S21, that is, data indicating that the battery 30 is in an overdischarged state to the controller 40. Furthermore, in step S24, the display unit 31 performs a first notification that notifies the operator that the battery 30 is in an overdischarged state, and the process proceeds to step S26. Hereinafter, the first notification will be described in detail.

  As shown in FIG. 6, in the present embodiment, the calculation unit 36 of the display unit 31 blinks the capacity display of the battery 30 displayed on the display 32 to inform the operator that the battery 30 is in an overdischarged state. A first notification is made. That is, during the normal time when the first notification is not performed, the capacity display of the battery 30 is always lit, whereas when the first notification is performed, the capacity display of the battery 30 is indicated by a blinking display which is a display form different from the normal display. As a result, the capacity display of the battery 30 is emphasized. This prompts the operator to charge the battery 30 and suppresses the battery 30 from being maintained in an overdischarged state. Therefore, the display 32 functions as a notification unit, and the calculation unit 36 of the display unit 31 functions as a control unit.

  As shown in FIG. 5, when the determination result of step S21 is negative, that is, when the battery 30 is not in an overdischarged state, the display unit 31 proceeds to step S25. In step S25, the display unit 31 stops the time measurement by the timer 33, and the process proceeds to step S26. Specifically, the calculation unit 36 of the display unit 31 stops the timer 33 when the time is measured by the timer 33, and when the time is not measured by the timer 33, The state where the time measurement by the timer 33 is not performed is maintained. When the time measurement is stopped from the state in which the accumulated time during which the battery 30 is maintained in the overdischarged state by the timer 33 is being measured, the battery 30 in the overdischarged state is charged by charging the battery 30 in the overdischarged state. This is when the remaining capacity exceeds 20%. That is, the measurement of the accumulated time during which the battery 30 is maintained in the overdischarged state is stopped on the condition that the remaining capacity of the battery 30 exceeds the overdischarge determination threshold.

  In step S <b> 26, the display unit 31 determines whether or not the accumulated time during which the battery 30 is maintained in the overdischarged state is equal to or greater than the accumulated threshold. The integration threshold is set to a time shorter than the lifetime determination threshold for determining the lifetime of the battery 30, and in this embodiment, about half of the lifetime determination threshold is set as the integration threshold. When the accumulated time during which the battery 30 is maintained in the overdischarged state is equal to or greater than the lifetime determination threshold value, it is determined that the performance of the battery 30 has deteriorated until it cannot be practically used, and reference symbol A in FIG. As shown, the display 32 prompts the user to replace the battery 30. The integration threshold indicates that the deterioration of the battery 30 is progressing by maintaining the battery 30 in the overdischarge state before the integration time during which the battery 30 is maintained in the overdischarge state reaches the lifetime determination threshold. It is set to notify the person. The integration threshold value and the life determination threshold value are stored in the storage unit 35 of the display unit 31. As shown in FIG. 5, when the determination result of step S26 is affirmative, that is, when the accumulated time during which the battery 30 is maintained in the overdischarged state is equal to or greater than the accumulated threshold, the display unit 31 proceeds to step S27. On the other hand, when the determination result of step S26 is negative, that is, when the accumulated time during which the battery 30 is maintained in the overdischarged state is less than the accumulated threshold value, the display unit 31 ends the process.

  In step S <b> 27, the display unit 31 determines whether or not the accumulated time during which the battery 30 is maintained in the overdischarged state is equal to or greater than a life determination threshold value. If the determination result in step S27 is affirmative, that is, if the accumulated time during which the battery 30 is maintained in the overdischarged state exceeds the lifetime determination threshold value, the display unit 31 proceeds to step S28. On the other hand, if the determination result in step S27 is negative, that is, if the accumulated time during which the battery 30 is maintained in the overdischarged state is less than the lifetime determination threshold value, the display unit 31 proceeds to step S29.

  In step S <b> 28, the display unit 31 performs a display prompting replacement of the battery 30. That is, the display unit 31 performs the display indicated by the symbol A in FIG. 3, and the process proceeds to step S30. In step S29, the display unit 31 proceeds to step S30 without performing a display prompting the replacement of the battery 30. Therefore, when the performance of the battery 30 deteriorates until it cannot withstand practical use, a display prompting replacement of the battery 30 is performed. This display is performed in parallel with a display prompting charging of the battery 30.

  In step S30, the display unit 31 determines whether or not the remaining capacity of the battery 30 is equal to or less than a notification threshold. If the determination result of step S30 is affirmative, that is, if the remaining capacity of the battery 30 is equal to or less than the notification threshold, the display unit 31 proceeds to step S31. On the other hand, if the determination result of step S30 is negative, that is, if the remaining capacity of the battery 30 is greater than the notification threshold, the display unit 31 ends the process. As the notification threshold, a value having a larger remaining capacity of the battery 30 than the overdischarge determination threshold is set. In this embodiment, the notification threshold is set to 30% of the total capacity of the battery 30 (remaining capacity 30%). As described above, even when the battery 30 is not in the overdischarged state, the deterioration of the battery 30 is progressing when the accumulated time during which the battery 30 is maintained in the overdischarged state exceeds the accumulated time. For this reason, when the remaining time of the battery 30 is less than or equal to the notification threshold value in order to suppress the accumulated time during which the battery 30 has been maintained in the overdischarged state from further increasing and reaching the lifetime determination threshold value, in step S31 Even when the battery 30 is not in the overdischarged state, the second notification is performed to suppress the battery 30 from being in the overdischarged state. The notification threshold value is stored in the storage unit 35 of the display unit 31.

  As shown in FIG. 7, in this embodiment, the display unit 31 causes the capacity display of the battery 30 displayed on the display 32 to blink, thereby highlighting the capacity display of the battery 30 and prompting the operator to charge. Notification of 2 is performed. At this time, the display unit 31 performs notification in a manner different from the first notification performed when the battery 30 is in an overdischarged state. In the present embodiment, in the first notification, all symbols corresponding to the remaining capacity of the battery 30 are turned on, whereas in the second notification, only some symbols are blinked and the remaining symbols are always displayed. Announcement is performed in the state of lighting. When the battery 30 reaches an overdischarged state (remaining capacity of 20% or less) while the second notification is being performed, the second notification is stopped and the first notification is performed. In addition, when the first notification is performed, if the integration time during which the battery 30 is maintained in the overdischarged state exceeds the integration threshold, the first notification is continued.

  As described above, the display unit 31 changes the notification timing depending on whether or not the accumulated time during which the battery 30 is maintained in the overdischarged state is equal to or greater than the accumulated threshold. When the accumulated time during which the battery 30 is maintained in the overdischarged state is less than the accumulated threshold value, the display unit 31 performs the first notification when the remaining capacity of the battery 30 becomes equal to or less than the overdischarge determination threshold value. On the other hand, the display unit 31 performs the second notification when the remaining capacity of the battery 30 is equal to or less than the notification threshold when the integration time during which the battery 30 is maintained in the overdischarged state is equal to or greater than the integration threshold. .

  As shown in FIG. 5, after transmitting the remaining capacity data to the display unit 31 in step S <b> 11, the controller 40 determines whether or not data indicating that the battery 30 is in an overdischarged state is received in step S <b> 12. When the battery 30 is in an overdischarged state, a message to that effect is transmitted from the display unit 31, so that the controller 40 can grasp whether or not the battery 30 is in an overdischarged state. If the determination result of step S12 is affirmative, that is, if the battery 30 is in an overdischarged state, the controller 40 proceeds to step S13. On the other hand, when the determination result of step S12 is negative, the controller 40 ends the process.

  In step S13, the controller 40 performs cargo handling restriction. The cargo handling restriction of the present embodiment means that when the traveling operation and the cargo handling operation of the forklift 10 are performed simultaneously, that is, when the cargo handling lever 22 and the accelerator pedal 23 are operated simultaneously, the forklift 10 performs the traveling operation. This indicates that the lifting / lowering operation and the tilting operation of the cargo handling device 14 are not performed.

Therefore, according to the above embodiment, the following effects can be obtained.
(1) When the accumulated time in which the battery 30 is maintained in the overdischarged state is equal to or greater than the accumulated threshold, the second notification is performed when the remaining capacity of the battery 30 is equal to or less than the notification threshold. For this reason, when the accumulated time in which the battery 30 is maintained in the overdischarged state is equal to or greater than the accumulated threshold, a notification is made to prompt charging in a state where the remaining capacity of the battery 30 is greater than when the accumulated value is less than the accumulated threshold. Person can be charged. For this reason, it can suppress that the battery 30 will be in an overdischarge state, and can suppress deterioration of the battery 30. FIG.

  (2) The notification mode is different between the first notification and the second notification. For this reason, it can be grasped | ascertained from the alerting | reporting aspect whether the remaining capacity of the battery 30 is below the overdischarge determination threshold value or more than the overdischarge determination threshold value. In addition, the first notification that is performed when the remaining capacity of the battery 30 is equal to or less than the overdischarge determination threshold is greater than the notification that is performed when the remaining capacity of the battery 30 is greater than the overdischarge determination threshold and less than the notification threshold. In the case of emphasizing also, it is possible to emphasize the notification that prompts charging of the battery 30 when the remaining capacity of the battery 30 decreases. That is, the worker can recognize that the battery 30 should be charged immediately after confirming the first notification. Further, when confirming the second notification, the worker can recognize that the battery 30 has deteriorated and can charge the battery before the remaining capacity reaches the overdischarge determination threshold.

  (3) When the remaining capacity of the battery 30 exceeds the overdischarge determination threshold, measurement of the accumulated time during which the battery 30 is maintained in the overdischarge state is stopped. For this reason, the integration time during which the battery 30 is maintained in the overdischarged state can be appropriately measured.

  (4) The operator is notified by highlighting the capacity display displayed on the display 32. For this reason, visual notification can be performed. In addition, when the notification is continued when the battery 30 is in an overdischarged state in order for the worker to accurately grasp the notification, the notification by sound is difficult depending on the surrounding environment of the forklift 10, but the capacity display is emphasized. The display can be performed without being affected by the surrounding environment.

(5) By performing the cargo handling restriction when the battery 30 is in an overdischarged state, in addition to the capacity display, the operator can be notified by the cargo handling restriction.
(6) When the accumulated time during which the battery 30 is maintained in the overdischarged state exceeds the lifetime determination threshold value, the display unit 31 performs a display prompting replacement of the battery 30. According to this, the controller 40 can automatically notify the operator of the replacement timing of the battery 30 without requiring analysis work by the worker or field engineer.

In addition, you may change embodiment as follows.
The cargo handling restriction may be performed by making the speed of the lifting / lowering operation and the tilting motion of the cargo handling device 14 slower than the speed corresponding to the operation amount of the cargo handling lever 22.

The display unit 31 may display on the display 32 that the cargo handling restriction is performed when the cargo handling restriction is performed (when the battery 30 is in an overdischarged state).
In place of emphasizing the capacity display of the battery 30, the first notification or the second notification may be performed by a buzzer sound or a sound from the speaker 34. In addition to emphasizing the capacity display of the battery 30 Then, the first notification or the second notification may be performed by a buzzer sound or a sound from the speaker 34. Further, the first notification and the second notification may be performed by displaying on the display 32 that the battery 30 is in an overdischarged state without emphasizing the capacity display.

  A first notification performed when the remaining capacity of the battery 30 is equal to or less than the overdischarge determination threshold, and a second notification performed when the remaining capacity of the battery 30 is greater than the overdischarge determination threshold and equal to or less than the notification threshold. The mode of notification is not limited to the embodiment. For example, the second notification that is performed when the remaining capacity of the battery 30 is greater than the overdischarge determination threshold and less than or equal to the notification threshold is set to sound notification, and the first notification is performed when the battery 30 is in the overdischarge state. May be notified by emphasizing the capacity display. Moreover, you may change the aspect of a 1st alerting | reporting and a 2nd alerting | reporting by varying the blink speed of the symbol of a capacity | capacitance display. That is, the different notification modes may be notifications by different methods by the same notification unit or may be notifications by different members.

  A first notification performed when the remaining capacity of the battery 30 is equal to or less than the overdischarge determination threshold, and a second notification performed when the remaining capacity of the battery 30 is greater than the overdischarge determination threshold and equal to or less than the notification threshold. The notification mode may be the same.

  When the first notification and the second notification are different from each other and the first notification and the second notification can be performed simultaneously, the remaining capacity of the battery 30 is larger than the overdischarge determination threshold. The first notification and the second notification may be performed in parallel at the following times.

  ○ Depending on whether or not the accumulated time during which the battery 30 is maintained in the overdischarge state is equal to or greater than the accumulation threshold, the first notification mode performed when the remaining capacity of the battery 30 is equal to or less than the overdischarge determination threshold may be varied. Good.

  The remaining capacity of the battery 30 may be measured from at least one of the current of the battery 30 and the voltage of the battery 30. Further, it may be measured from the current of the battery 30 and the temperature of the battery 30, or may be measured from the voltage of the battery 30 and the temperature of the battery 30.

The battery 30 may be a lithium ion battery or a nickel metal hydride battery.
The controller 40 may determine whether or not the battery 30 is in an overdischarged state. In this case, the controller 40 may perform notification using the display 32, the speaker 34, or the like.

  A single member that performs both the processing performed by the controller 40 in the embodiment and the processing performed by the display unit 31 may be provided. That is, in addition to running and cargo handling, a control device that performs overall display on the display 32 may be provided.

O There is no need to restrict the handling of the battery 30 in the overdischarged state. Also, cargo handling restriction may be performed when the remaining capacity of the battery 30 is equal to or less than the notification threshold.
The timer 33 may be reset each time the measurement of the accumulated time during which the battery 30 is maintained in the overdischarged state is stopped. In this case, before the timer 33 is reset, the measured overdischarge state maintenance time is stored in the storage unit 35. And the integration time of the time when the battery 30 was maintained in the overdischarged state is measured by adding the maintenance time memorize | stored in the memory | storage part 35. FIG.

The classification of the capacity display displayed on the display 32 may not be 10 levels, but may be 5 levels or 3 levels.
The battery type industrial vehicle may be other than the forklift 10. For example, a towing vehicle (conveyance vehicle) such as a towing tractor may be used.

  -The alerting | reporting part may be portable terminals, such as a smart phone which an operator has. In this case, when the battery 30 is in an overdischarged state, the controller 40 and the display unit 31 communicate with the smartphone to notify the smartphone. The notification may be displayed on the screen of the mobile terminal, or may be audio flowing from the speaker 34 of the mobile terminal.

The temperature sensor 53 may be connected to the controller 40.
The overdischarge determination threshold, the notification threshold, and the integration time threshold are set based on experiments and simulations, and may be arbitrarily changed.

  In the process shown in FIG. 5, when the key switch 43 is off, it is only necessary to be able to perform a process that can measure the accumulated time of the overdischarge state, and it is not necessary to perform notification.

  DESCRIPTION OF SYMBOLS 10 ... Forklift, 30 ... Battery, 31 ... Display unit, 32 ... Display, 33 ... Timer, 34 ... Speaker, 36 ... Calculation part, 40 ... Controller, 51 ... Current sensor, 52 ... Voltage sensor, 53 ... Temperature sensor.

Claims (4)

A battery-powered industrial vehicle that travels using a battery as a drive source,
A remaining capacity measuring member for measuring the remaining capacity of the battery;
An overdischarge time integration unit for measuring an integration time in which the remaining capacity of the battery is maintained below an overdischarge determination threshold;
A control unit for notifying the notification unit according to the remaining capacity of the battery,
The controller is
When the accumulated time measured by the overdischarge time accumulation unit is less than an accumulation threshold, when the remaining capacity of the battery becomes equal to or less than the overdischarge determination threshold, the notification unit performs a first notification,
If the accumulated time measured by the overdischarge time integrating unit is equal to or greater than the integrated threshold, the notification unit performs a second notification when the remaining capacity of the battery is equal to or less than a notification threshold;
The notification threshold is a battery-powered industrial vehicle having a larger remaining battery capacity than the overdischarge determination threshold.   The battery-powered industrial vehicle according to claim 1, wherein the first notification and the second notification are notifications of different modes.   The battery-powered industrial vehicle according to claim 1, wherein the overdischarge time integration unit stops measuring the integration time when a remaining capacity of the battery exceeds the overdischarge determination threshold. The notification unit is a display,
The battery control industry according to any one of claims 1 to 3, wherein the control unit performs notification by displaying a capacity display of the battery displayed on the display in a display form different from normal. vehicle.