JP2019068686A - Battery-type industrial vehicle - Google Patents

Abstract

To provide a battery-type industrial vehicle which can avoid that a battery device is brought into a block state by suppressing the overdischarge/overvoltage of the battery device at a low temperature without remodeling the battery device, and can make an operator further surely recognize that there may arise an overdischarge/overvoltage state in the battery device if continuing work as it is by daringly making the battery-type industrial vehicle difficult in use at the low temperature.SOLUTION: A battery-type industrial vehicle comprises: a drive motor; a battery device for outputting power when the drive motor is driven, and inputted with power when the drive motor is regeneratively operated; temperature detection means for detecting a temperature of a battery in the battery device; and a control device for controlling an output of the drive motor so as to be limited according to the temperature of the battery when the temperature of the battery detected by the temperature detection means is in a first low-temperature state not higher than a prescribed limit start temperature.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a battery-powered industrial vehicle provided with a battery device and a drive motor as power sources for traveling and cargo handling.

  BACKGROUND ART In recent years, battery-powered industrial vehicles such as electric forklifts have been used to transport luggage in indoor warehouses and the like that dislike the exhaust gas of internal combustion engines. As an example of the battery type industrial vehicle of the present invention, a reach type forklift 10 shown in FIG. 1 will be described. The reach type forklift 10 uses a battery device and a drive motor as a driving power source, and is a stand-up type forklift that operates in a state where the operator stands. In FIG. 1, the X-axis, the Y-axis, and the Z-axis are orthogonal to one another, the Z-axis direction indicates a vertically upward direction, the X-axis direction indicates a forward direction, and the Y-axis direction indicates a left direction. .

  As shown in FIG. 1, the reach type forklift 10 includes a reach leg 11, a mast 17, a fork 16, a right driven wheel 18R, a left driven wheel 18L, a drive steering wheel 18D, a caster wheel 18C, an accelerator lever 12 and the like. . Although not shown, the reach type forklift 10 also has an operation lever for operating the fork 16 and the mast 17, a steering for steering, and the like.

  The reach legs 11 are provided as a pair on the left and right, and are provided to project forward from the lower part of the vehicle body. Further, a right driven wheel 18R and a left driven wheel 18L are provided in each of the pair of reach legs 11 (11R, 11L). The masts 17 (17R, 17L) are provided as a pair on the left and right, and can slide in the front-rear direction along the reach leg 11, and can tilt in the front-rear direction. The forks 16 are provided in a pair on the left and right, and are slidable (liftable) in the vertical direction along the mast 17.

  The right driven wheel 18R is provided in the vicinity of the front end of the reach leg 11R on the right side, and the direction is fixed in the front-rear direction of the reach type forklift 10 and is rotatably provided. The left driven wheel 18L is provided in the vicinity of the front end of the left reach leg 11L, and the direction of the reach type forklift 10 is fixed in the front-rear direction, and is rotatably provided. The right driven wheel 18R and the left driven wheel 18L are provided as a left / right pair.

  The drive steered wheels 18D are wheels that can change (steer) the angle of the reach forklift 10 with respect to the front-rear direction, and are rotationally driven by the drive motor. The caster wheel 18C is a wheel that is supported on the reach forklift 10 so as to change its direction freely in the XY plane, and is supported so as to be rotatable.

  The accelerator lever 12 is a lever that can be operated from an upright neutral position to a forward lean position, or from a neutral position to a reverse lean position. When the operator tilts the accelerator lever 12 forward from the neutral position, the drive motor drives the drive steered wheels 18D in the forward direction, and the reach type forklift 10 advances at a speed according to the forward inclination angle of the accelerator lever 12. Then, when the operator returns the accelerator lever 12 to the neutral position, the operation of the drive motor is changed from drive control to regeneration control, and the reach type forklift 10 is decelerated gently (weak braking is applied).

  When the operator causes the accelerator lever 12 to tilt backward from the neutral position, the reach forklift 10 moves backward as described above, and when the accelerator lever 12 is returned to the neutral position, the reach forklift 10 is gentle as described above. Slow down (weak braking (normal braking) is applied). Further, when the accelerator lever 12 is tilted in the opposite direction to the traveling direction during forward or reverse traveling, the reach type forklift 10 is regeneratively controlled with a large regenerative force, and strong braking (sudden braking) is applied.

  Various proposals have been made for drive control of a drive motor at low temperatures in a battery-type industrial vehicle. For example, in the battery control device mounted on the electric vehicle described in Patent Document 1 below, the output from the battery is controlled based on the battery temperature, the charging rate (SOC) of the battery, and the required output of the motor. ing. Also, since battery performance generally decreases when the battery is in a low temperature state, the output control means performs output suppression to suppress the output from the battery when the battery temperature is less than the threshold temperature, and the output from the battery corresponds to the battery performance. A configuration is described that controls to be limited within the range.

JP, 2015-118789, A

  For example, in a general lithium ion battery device (corresponding to a battery device), at low temperatures, the voltage drop at the time of output becomes large and it is likely to be in an overdischarged state. In addition, at low temperatures, the voltage rise at the time of input (at the time of charging) becomes large, and it is easy to be in the overvoltage state. Furthermore, a general lithium ion battery device is packaged with a built-in lithium ion battery (corresponding to a battery) and a controller, and when the controller detects an overdischarged state or an over voltage state of the lithium ion battery, the lithium ion Shut off battery input / output. When the input / output of the lithium ion battery is shut off, the battery type industrial vehicle equipped with the lithium ion battery device can not be used. Therefore, it is desired to suppress the frequency of the shut off of the input / output.

  In the battery control device described in Patent Document 1, only the output of the battery at low temperature is limited, and the overdischarge at low temperature is taken into consideration. Is not considered. Moreover, the battery control apparatus described in patent document 1 is corresponded to the controller in the above-mentioned lithium ion battery apparatus packaged. Therefore, although it is relatively easy for a supplier of the lithium ion battery device to improve the controller in the packaged lithium ion battery device, it is very difficult for the user of the lithium ion battery device. is there.

  In addition, when working at low temperatures using a battery-powered industrial vehicle, it is close to a display device (such as a display panel provided in the vicinity of an accelerator lever or the like) before the battery is in an overdischarge / overvoltage state (or shut off state). When the operator who is concentrating on the work in the freezer warehouse or the like does not notice the notification even if the operator warns the operator that there is a possibility of being in the overdischarge / overvoltage state (or shut off state) at one time. There is. It is desirable to be notified in a manner that allows the operator to more reliably recognize that the battery may become over-discharged / over-voltage (or shut off) in the near future.

  The present invention has been made in view of such a point, and the battery device is in a cut-off state by suppressing overdischarge and overvoltage of the battery device at low temperature in a simple manner without modifying the battery device. By making it difficult to use the battery-powered industrial vehicle at low temperatures while continuing to work, it is more reliably possible that the battery device may eventually become overdischarged / overvoltageed. An object is to provide a battery-powered industrial vehicle that can be recognized by an operator.

  In order to solve the above problems, a first invention of the present invention is a battery-type industrial vehicle provided with a battery device and a drive motor as a power source, wherein the drive motor and the drive motor are driven and operated. The battery device to which electric power is output and to which the electric power at the time of causing the drive motor to be regenerated is input, temperature detection means for detecting the temperature of the battery in the battery device, and the above detected by the temperature detection means A control device configured to control the output of the drive motor to be limited according to the temperature of the battery when the temperature of the battery is in a first low temperature state equal to or lower than a predetermined limit start temperature; is there.

  Next, according to a second aspect of the present invention, in the battery type industrial vehicle according to the first aspect, the output of the drive motor limited by the control device is the number of rotations of the drive motor or the number of the drive motor It is a battery-powered industrial vehicle that is torque.

  Next, a third invention of the present invention is a battery-type industrial vehicle including a battery device and a drive motor as a power source, which outputs the drive motor and electric power for driving the drive motor. The battery device to which power when the drive motor is caused to perform a regenerative operation is input, temperature detection means for detecting the temperature of the battery in the battery device, and the temperature of the battery detected by the temperature detection means A control device configured to control the regenerative power of the drive motor to be limited according to the temperature of the battery in a first low temperature state equal to or lower than a predetermined limit start temperature; is there.

  Next, according to a fourth aspect of the present invention, there is provided a battery-powered industrial vehicle including a battery device and a drive motor as a power source, which outputs the drive motor and electric power for driving the drive motor. The battery device to which power when the drive motor is caused to perform a regenerative operation is input, temperature detection means for detecting the temperature of the battery in the battery device, and the battery-powered industrial vehicle or the battery with an operation amount Accelerator lever capable of instructing the speed of a movable portion of a type industrial vehicle, operation state detection means for detecting an operation state of the accelerator lever, and the accelerator lever recognized based on a detection signal from the operation state detection means And a controller for controlling the output of the drive motor in accordance with an accelerator-recognizing operation amount, which is the operation amount. The accelerator recognition operation amount is limited according to the temperature of the battery when the temperature of the battery detected by the battery is in the first low temperature state equal to or lower than a predetermined limit start temperature, and the accelerator recognition operation amount is limited based on the limited amount. A battery-powered industrial vehicle that controls the output of the drive motor.

  Next, according to a fifth invention of the present invention, in the battery type industrial vehicle according to any one of the first to fourth inventions, the control device is in the first low temperature state. The battery-powered industrial vehicle is controlled such that the upper limit value of the control amount to be limited according to the temperature of the battery is set to gradually decrease as the temperature of the battery decreases from the predetermined restriction start temperature.

  Next, according to a sixth aspect of the present invention, in the battery type industrial vehicle according to any one of the first to fourth aspects, the control device is in the first low temperature state. The battery-powered industrial vehicle is controlled such that the upper limit value of the control amount to be limited according to the temperature of the battery is set to decrease stepwise as the temperature of the battery decreases from the predetermined restriction start temperature.

  Next, according to a seventh invention of the present invention, in the battery type industrial vehicle according to any one of the first invention to the sixth invention, the temperature of the battery device detected by the temperature detecting means is And, when the temperature is lower than the predetermined limit start temperature and not more than a predetermined temperature preset, the output of the power from itself and the input of the power to itself are cut off, and the control device detects by the temperature detection means The temperature of the battery is lower if the temperature of the battery is lower than the predetermined limit start temperature and is lower than a predetermined lower limit temperature higher than the predetermined temperature to the predetermined temperature; The battery-powered industrial vehicle is controlled to set the upper limit value of the control amount to be limited according to the minimum upper limit value.

  An eighth invention of the present invention is the battery-powered industrial vehicle according to any one of the first to seventh inventions, wherein the battery-powered industrial vehicle is a fork used to lift a load. And an electric traction vehicle capable of pulling a tow, the drive motor for traveling, or the drive motor for traveling and cargo handling, or the driving motor for cargo handling , A battery-powered industrial vehicle.

  According to the first invention, when it is determined that the temperature of the battery is in the first low temperature state equal to or lower than the predetermined limit start temperature, the output of the drive motor is limited according to the temperature of the battery. The operation of the drive motor of the industrial vehicle can be restricted and hard to use. As a result, at the time of low temperature operation, if the operation is continued as it is, the operator can be surely recognized that the battery will be in the overdischarge / overvoltage state (or shut off state) in a short time. In addition, by limiting the output of the drive motor, overdischarge and overvoltage of the battery device at low temperature can be suppressed by an easy method without touching the battery device, and the battery device can be prevented from being cut off. be able to.

  According to the second invention, when it is determined that the temperature of the battery is in the first low temperature state equal to or lower than the predetermined limit start temperature, the number of rotations of the drive motor or the torque of the drive motor is limited. When the motor is for traveling, the traveling speed and the acceleration state become slower according to the temperature of the battery. As a result, it becomes difficult to use according to the temperature of the battery during low temperature work, so that if the work continues, the operator is surely made to recognize that the battery will be in the overdischarge / overvoltage state (or shut off state) in the future. Can. In addition, by limiting the number of rotations or torque of the drive motor, overdischarge and overvoltage of the battery device at low temperature can be suppressed by an easy method without changing the battery device, and the battery device will be in a disconnected state. Can be suppressed.

  According to the third invention, when it is determined that the temperature of the battery device is in the first low temperature state equal to or lower than the predetermined limit start temperature, the regenerative force by the regenerative operation of the drive motor is limited according to the temperature of the battery. Therefore, the braking operation of the battery-powered industrial vehicle can be limited to make it difficult to use. As a result, at the time of low temperature operation, if the operation is continued as it is, the operator can be surely recognized that the battery will be in the overdischarge / overvoltage state (or shut off state) in a short time. Further, by limiting the regenerative force of the drive motor, it is possible to suppress the overvoltage of the battery device at a low temperature by an easy method without touching the battery device and to suppress the battery device from being in the disconnected state. it can.

  According to the fourth invention, when it is determined that the battery temperature is in the first low temperature state equal to or lower than the predetermined limit start temperature, the accelerator recognized based on the operation amount of the accelerator lever according to the battery temperature The recognition operation amount is limited. Then, the output of the drive motor is controlled based on the limited accelerator recognition operation amount. That is, for example, when the drive motor is for traveling, the traveling operation of the battery-powered industrial vehicle with respect to the operation amount of the accelerator lever can be reliably restricted according to the temperature of the battery to make it more difficult to use. As a result, at the time of low temperature operation, if the operation is continued as it is, the operator can be surely recognized that the battery will be in the overdischarge / overvoltage state (or shut off state) in a short time. In addition, by limiting the accelerator recognition operation amount, overdischarge and overvoltage of the battery device at low temperature can be suppressed by an easy method without touching the battery device, and the battery device can be prevented from being shut off. be able to.

  According to the fifth aspect of the invention, the upper limit value of the control amount to be limited according to the temperature of the battery is set to be gradually decreased as the temperature of the battery decreases from the predetermined limit start temperature in the first low temperature state. Therefore, the operation of the drive motor of the battery-powered industrial vehicle can be gradually reduced. As a result, if the low temperature operation is continued, the operator can be surely recognized that the battery will be in the overdischarge / overvoltage state (or in the cut-off state) eventually. In addition, by gradually reducing the upper limit value of the control amount as the battery temperature decreases, overdischarge and overvoltage of the battery device at low temperatures can be suppressed by an easy method without modifying the battery device. It is possible to prevent the battery device from being in the disconnected state. Therefore, by gradually decreasing (lowering) the upper limit value, it is possible to urge the operator to charge while avoiding an immediate interruption of work.

  According to the sixth aspect of the invention, the upper limit value of the control amount to be limited according to the temperature of the battery in the first low temperature state is decreased stepwise as the temperature of the battery decreases from the predetermined limit start temperature. Since the setting is made, the operation of the drive motor of the battery-powered industrial vehicle can be reduced stepwise. As a result, if the low temperature operation is continued, the operator can be surely recognized that the battery will be in the overdischarge / overvoltage state (or in the cut-off state) eventually. In addition, the upper limit value of the control amount is reduced stepwise as the battery temperature decreases, thereby suppressing overdischarge / overvoltage of the battery device at low temperature by an easy method without modifying the battery device. Thus, the battery device can be prevented from being disconnected.

  According to the seventh invention, when it is determined that the temperature of the battery is lower than the predetermined limit start temperature, and is the second low temperature state from the predetermined usable lower limit temperature higher than the prescribed temperature to the prescribed temperature. In order to drive the drive motor, the upper limit value of the control amount to be limited according to the temperature of the battery is set to the minimum upper limit value. Therefore, the operator can be more surely recognized that the operation of the drive motor of the battery-powered industrial vehicle is maximally limited and the overdischarge / overvoltage state (or cutoff state) will soon be realized. Therefore, it is possible to reliably urge the operator to stop the work and move the battery-powered industrial vehicle to the charging place, and to prevent a stop during the operation of the battery-powered industrial vehicle or so-called regeneration failure. Can. Further, in the second low temperature state, the operation of the drive motor is not stopped but the drive motor is operated with the maximum restriction applied, so that the stop of the battery-powered industrial vehicle can be suppressed during the operation.

  According to the eighth invention, when the operator of the electric forklift or the electric traction vehicle working in the freezing warehouse, the extremely cold airport, or the port continues the work as it is, the battery is overdischarged / overvoltageed (or shut off) Can be recognized more reliably. Further, overdischarge and overvoltage of the battery device at low temperature can be suppressed by an easy method without changing the battery device, and the battery device can be prevented from being in the disconnected state.

It is a perspective view which shows the example of the external appearance of the battery type industrial vehicle which concerns on 1st Embodiment. It is a figure explaining the input-output of the traveling control system containing the battery apparatus and drive motor of the battery type industrial vehicle of FIG. It is a flowchart which shows the 1st low temperature warning process which a machine control apparatus performs in the control system shown in FIG. It is a figure which shows an example of the operation mode table which a machine control apparatus memorize | stores. It is a figure which shows an example of the upper limit rotation speed of a drive motor according to the battery temperature in a low temperature state. It is a flowchart which shows the low temperature output process which a battery control apparatus performs in the control system shown in FIG. It is a flowchart which shows the low temperature drive processing which an inverter control apparatus performs in the control system shown in FIG. It is a flow chart which shows the 2nd low temperature warning processing which the machine control control device of the battery type industrial vehicle concerning a 2nd embodiment performs. It is a figure which shows an example of the upper limit regenerative power of the normal braking of the drive motor according to the battery temperature in the low temperature state of the battery type industrial vehicle which concerns on 2nd Embodiment. It is a figure which shows an example of the upper limit regenerative power of rapid braking of the drive motor according to the battery temperature in the low temperature state of the battery type industrial vehicle which concerns on 2nd Embodiment. It is a flow chart which shows the 3rd low temperature warning processing which the machine control control device of the battery type industrial vehicle concerning a 3rd embodiment performs. It is a figure which shows an example of the accelerator opening degree ratio according to the battery temperature in the low temperature state of the battery type industrial vehicle which concerns on 3rd Embodiment.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a battery type industrial vehicle according to the present invention will be described in detail with reference to the drawings based on first to third embodiments in which a reach type forklift is embodied. First, the reach-type forklift 10 according to the first embodiment will be described based on FIGS. 1 to 7.

First Embodiment (FIGS. 1 to 7)
The appearance of the reach-type forklift 10 (an example of a battery-powered industrial vehicle) according to the first embodiment shown in FIG. 1 has already been described, and thus the description thereof is omitted.

● [Travel control system including the battery device 30 and the drive motor 21 (FIG. 2)]
Next, a travel control system of the reach type forklift 10 will be described based on FIG. As shown in FIG. 2, the travel control system of the reach type forklift 10 includes a battery 30, an inverter 40, a drive motor 21, a gear 22, a drive steering wheel 18D, a machine control 50, an accelerator lever 12, and a display 55. Etc.

  The battery device 30 includes a battery control device 31 and a battery 32. The battery 32 includes a shutoff switch 38, a plurality of battery module units 33, and the like. The cutoff switch 38 may be included in each battery module unit. The battery module unit 33 includes a battery module 34 configured of a plurality of battery cells 36 (for example, lithium ion batteries), a module controller 35 that controls the battery module 34, and a temperature detection unit 37 that detects the temperature of the battery module 34 ( It has a temperature sensor etc.). The module controller 35 performs temperature monitoring of the battery module 34, status monitoring of each battery cell 36, charge / discharge control, and the like.

  The battery control device 31 transmits / receives various information to / from each module controller 35 via the communication line T31, and controls the cutoff switch 38 via the control signal line C31. In addition, the battery control device 31 transmits and receives various information to and from the machine control device 50 via the communication line T53. Then, when driving the drive motor 21, the battery device 30 outputs the supplied power Wout1 (DC power) from the terminal 33A and the terminal 33B. In addition, when the drive motor 21 is operated for regeneration, the charging power Win2 (DC power) is input to the terminal 33A and the terminal 33B.

  The inverter device 40 includes an inverter control device 41 and an inverter 42. The inverter 42 includes an inverter circuit 43 and the like. When driving the drive motor 21, the inverter circuit 43 is controlled based on a control signal from the inverter control device 41 via the communication line T41, and supplies the supply power Wout1 input from the battery device 30 with the drive power Wout2 (AC Power, and output to the drive motor 21. In addition, when the drive motor 21 is caused to perform a regenerative operation, the inverter circuit 43 is controlled based on the control signal from the inverter control device 41 and charges the regenerative power Win1 (AC power) input from the drive motor 21 to the charging power Win2 (DC Power, and output to the battery device 30.

  The inverter control device 41 transmits and receives various information to and from the machine control device 50 via the communication line T54. When inverter control device 41 receives from drive control device 50 an instruction (for example, the rotation direction of the drive motor) of the drive operation of drive motor 21 and drive information including the target number of revolutions etc., based on the received drive information And control the inverter circuit 43 via the communication line T41.

  In addition, when the inverter control device 41 receives from the machine control device 50 an instruction (for example, the rotation direction of the drive motor) of the regenerative operation of the drive motor 21 and regenerative information including regenerative force etc., based on the received regenerative information. Thus, the inverter circuit 43 is controlled via the communication line T41. Further, a detection signal from a motor rotation detection means 23 (rotation sensor etc.) capable of detecting the rotational direction and the number of rotations of the drive motor 21 is inputted to the inverter control device 41 through the signal line C41. The rotational direction and rotational speed of the motor shaft 21 can be detected.

  When drive operation is performed, the drive motor 21 is rotationally driven in the forward direction or the reverse direction by the drive power Wout2 from the inverter device 40. The rotational driving force is, for example, transmitted to the drive steering wheel 18D via the gear 22. Further, when the drive motor 21 is operated for regeneration, it is rotationally driven from the drive steering wheel 18D via the gear 22 and generates regenerative electric power Win1.

  The machine control device 50 (corresponding to the control device) can transmit and receive various information to and from the battery control device 31 via the communication line T53. For example, the machine control device 50 transmits transmission request information for requesting transmission of battery information to the battery control device 31, and from the battery control device 31, the battery temperature, the battery voltage, and the battery state (for example, battery abnormality or normality). Receive battery information including

  Further, the machine control device 50 can transmit and receive various information to and from the inverter control device 41 via the communication line T54. For example, the machine control device 50 transmits transmission request information for requesting transmission of inverter information to the inverter control device 41, and receives inverter information including the number of rotations and the rotation direction of the drive motor 21 from the inverter control device 41. . Further, when driving the drive motor 21, the machine control device 50 transmits drive information including the drive operation, the number of rotations, and the rotation direction to the inverter control device 41. Further, the machine control device 50 transmits regeneration information including a regeneration operation and a regeneration force to the inverter control device 41 when the drive motor 21 performs the regeneration operation.

  The accelerator lever 12 is used by the operator to instruct the travel and stop of the reach type forklift 10, and is maintained in a substantially upright and neutral state when the operator does not touch the hand. The accelerator lever 12 is configured to be able to tilt forward from the neutral state, or to tilt rearward from the neutral state. In addition, in the accelerator lever 12, an operation state detection unit 12A (an encoder or the like that can detect the inclination direction to the front and back of the accelerator lever 12, and the inclination angle from the neutral state (accelerator opening (operation amount)) A rotation angle sensor etc. is provided. The detection signal from the operation state detection means 12A is input to the machine control device 50, and the machine control device 50 controls the inclination direction of the accelerator lever 12 and the inclination angle from the neutral state (accelerator opening The amount of operation) can be detected.

  When the operator operates the accelerator lever 12 to tilt forward from the neutral state with the reach type forklift 10 at a stop, the reach type forklift 10 starts to move forward, and the inclination angle of the accelerator lever 12 to the front is set. Accelerate to reach the desired speed. In addition, when the operator operates the accelerator lever 12 and makes it tilt backward from the neutral state with the reach type forklift 10 that is stopped, the reach type forklift 10 starts reverse movement, and the accelerator lever 12 inclines to the rear Accelerate to reach the speed according to the angle.

  The display device 55 is a liquid crystal monitor or the like provided at a position where the operator can easily view (for example, in the vicinity of the accelerator lever 12). The display device 55 displays various information based on the display information from the machine control device 50. The display device 55 may be omitted.

● [Process procedure of machine control device 50 (control device) (FIG. 3 to 5)]
The machine control device 50 (control device) activates the first low-temperature warning process shown in FIG. 3 at predetermined time intervals (for example, several ms to several 10 ms intervals), for example. Advance.

  In step S11, the machine control device 50 transmits transmission request information to the inverter control device 41, receives inverter information including the number of rotations and the rotation direction of the drive motor 21 from the inverter control device 41, and proceeds to step S12.

  At step S12, the machine control device 50 determines the operating direction of the accelerator lever 12 (forward direction, reverse direction or neutral position) and the neutral state of the accelerator lever 12 based on the detection signal input from the operation state detection means 12A. The inclination angle from the position of the vehicle, that is, the operation amount of the accelerator lever 12 (accelerator opening degree) (forward inclination angle or

  At step S13, the machine control device 50 controls the rotational state (rotational speed and rotational direction) of the drive motor 21 and the operating state of the accelerator lever 12 based on the stored operation mode table 61 (see FIG. 4). The operation mode is determined from the operation direction and the operation amount, and the determined operation mode is stored in the temporary operation mode. Further, the machine control device 50 obtains the rotational direction of the drive motor 21 based on the operation mode determined to be the rotational state of the drive motor 21 and the operation state of the accelerator lever 12 and stores it in the temporary rotational direction. The target rotational speed is calculated and stored in the temporary target rotational speed, and the target torque of the drive motor 21 is calculated and stored in the temporary target torque. Further, the machine control device 50 obtains the target regenerative power and stores it in the temporary target regenerative power, and proceeds to step S14. The details of the determination of the operation mode and the storage in the temporary operation mode and the like will be described below.

[Determination of operation mode (Fig. 4)]
As shown in FIG. 4, in the operation mode table 61 stored in the machine control device 50, operation modes corresponding to the operation state of the accelerator lever 12 and the rotation state of the drive motor 21 are stored. There is. For example, there are four types of operation modes: stop mode, travel start mode, travel continuation mode, and stop request mode.

  In the stop mode, when the current rotation of the drive motor 21 is stopped, and when the operation state of the accelerator lever 12 indicates the neutral position (the inclination angle input from the operation state detection means 12A is 0 degrees) And the operation mode determined in In the stop mode, the drive motor 21 is neither driven nor regenerated and the rotation of the drive motor 21 is stopped, and the reach type forklift 10 is stopped. When the machine control unit 50 determines that the stop mode is set, the machine control unit 50 stores the stop mode in the temporary operation mode, and stores 0 in the temporary target rotation speed and the temporary target torque.

  In the travel start mode, when the current rotation of the drive motor 21 is stopped, and when the operation state of the accelerator lever 12 instructs forward or reverse (before the operation state detection unit 12A is larger than 0 degrees) This is an operation mode determined when the tilt angle or the backward tilt angle is input. In the travel start mode, the drive motor 21 is driven to move forward or backward in accordance with the instruction of the accelerator lever 12, and the reach type forklift 10 which has been in the stopped state starts operating.

  When the machine control unit 50 determines that the vehicle is in the traveling start mode, the traveling start mode is stored in the temporary operation mode, and the forward or backward direction instructed by the accelerator lever 12 in the temporary rotation direction (input from the operation state detection means 12A Forward direction or backward direction) is stored. Further, the machine control device 50 stores the target rotation number obtained based on the operation amount of the accelerator lever 12 (forward tilt angle or back tilt angle input from the operation state detection unit 12A) in the temporary target rotation number. The torque corresponding to the target rotational speed is obtained and stored in the temporary target torque.

  In the traveling continuation mode, when the current drive motor 21 is rotating forward, and when the operation state of the accelerator lever 12 instructs to move forward (the forward inclination larger than 0 degree from the operation state detection means 12A) When an angle is input), or when the current drive motor 21 is rotating backward, and when the operation state of the accelerator lever 12 instructs reverse (from the operation state detection means 12A) This is an operation mode determined in the case where a backward inclination angle larger than an angle is input). That is, the traveling continuation mode is an operation mode in which the accelerator lever 12 is operated in the same direction as the traveling direction of the reach type forklift 10 during traveling.

  In the travel continuation mode, the drive motor 21 is driven in the same direction as the current rotation direction, and the number of rotations according to the amount of operation of the accelerator lever 12 (forward inclination angle or backward inclination angle input from the operation state detection means 12A) It is controlled by (or torque). If the machine control unit 50 determines that the running continuation mode is set, the running continuation mode is stored in the temporary operation mode, and the rotation direction of the current drive motor 21 in the temporary rotation direction or the direction instructed from the accelerator lever 12 (operation state The inclination direction input from the detection means 12A is stored. Further, the machine control device 50 stores, as the temporary target rotation number, the target rotation number obtained based on the operation amount of the accelerator lever 12 (forward tilt angle or back tilt angle input from the operation state detection means 12A), A torque corresponding to the target rotational speed is obtained and stored as a temporary target torque.

  In the stop request mode, when the current drive motor 21 is rotating forward (or backward) and when the operation state of the accelerator lever 12 instructs neutral (input from the operation state detection means 12A) (If the angle of inclination is 0 degrees), or if the current drive motor 21 is rotating forward, and if the operation state of the accelerator lever 12 instructs reverse (operation state detection means When a backward inclination angle larger than 0 degrees is input from 12A) or when the current drive motor 21 is rotating backward, and the operation state of the accelerator lever 12 instructs forward movement This is the case (when the forward tilt angle larger than 0 degrees is input from the operation state detection unit 12A).

  That is, the stop request mode is an operation mode in which the accelerator lever 12 is operated in the neutral position or in the direction opposite to the traveling direction with respect to the reach type forklift 10 during traveling. The regenerative power is roughly divided into two types of regenerative power: sudden braking and normal braking. In the rapid braking, a large braking corresponding to the rotational speed of the drive motor 21 is applied to stop the reach type forklift 10 at a relatively short distance. In normal braking, moderate braking corresponding to the rotational speed of the drive motor 21 is applied, and the reach forklift 10 stops at a relatively long distance.

  The normal braking stop request mode is an operation mode when the accelerator lever 12 is returned to the neutral position while the reach type forklift 10 is traveling forward (or backward), and corresponds to the number of rotations of the drive motor 21. The reach type forklift 10 which has been regenerated and operated with a medium regeneration force is stopped at a relatively long distance. The sudden braking stop request mode is an operation mode when the accelerator lever 12 is operated in the direction opposite to the traveling direction while the reach type forklift 10 is traveling forward (or backward), and is relatively The reach type forklift 10 which is being regenerated is operated with a large regenerative force and is traveling is stopped at a relatively short distance.

  When the machine control unit 50 determines that the stop request mode is set, the stop request mode is stored in the temporary operation mode, and the current rotation direction (forward or reverse side) of the drive motor 21 is stored in the temporary rotation direction. In addition, when neutral is instructed from the accelerator lever 12 (when the inclination angle input from the operation state detection means 12A is 0 degrees), the machine control device 50 sets the temporary target regeneration force to the drive motor 21 The regenerative force of normal braking corresponding to the rotational speed is stored. Further, when the traveling direction instructed from the accelerator lever 12 is reverse to the rotation direction of the drive motor 21, the machine control device 50 makes a sudden target regeneration force corresponding to the number of rotations of the drive motor 21. Store the regenerative power of braking.

  Returning to the explanation of the flowchart shown in FIG. 3, the machine control device 50 transmits transmission request information to the battery control device 31 in step S14, and the battery control device 31 includes a battery including battery voltage, battery temperature, and battery condition. After receiving the information, the process proceeds to step S15.

  In step S15, the machine control device 50 reads the battery temperature included in the battery information, and the battery temperature is equal to or less than the restriction start temperature T11 (° C.) at which the restriction on the upper limit rotational speed of the drive motor 21 starts. It is determined whether the temperature is lowered to the first low temperature state). The restriction start temperature T11 (° C.) is, for example, 0 ° C. to −5 ° C., and is a battery temperature preset for the battery 32 (for example, a lithium ion battery etc.). Are stored in advance. Then, when the machine control device 50 determines that the battery temperature has fallen below the restriction start temperature T11 (° C.) (S15: YES), the process proceeds to step S16, while the battery temperature is a restriction If it is determined that the temperature is higher than the start temperature T11 (° C.) (S15: NO), the process proceeds to step S15A described later.

  If the process proceeds to step S15A, the machine control device 50 cancels the display (when the display is erased) when “low temperature warning” (see step S20) is displayed on the display device 55, and the display device 55 is displayed. When the "stop warning" (see step S21) is displayed on the screen, the display is canceled (the display is turned off), and the process proceeds to step S22.

  In step S16, the machine control device 50 stores the battery temperature based on "Battery temperature · upper limit rotation number information (relationship information between battery temperature and upper limit rotation number of drive motor 21)" (see Fig. 5) stored in advance. After the upper limit rotational speed of the drive motor 21 corresponding to the above is determined and stored, the process proceeds to step S17.

  Here, “battery temperature · upper limit rotational speed information (relationship information between battery temperature and upper limit rotational speed of drive motor 21)” will be described based on FIG. As shown in FIG. 5, the battery temperatures T12, T13, T14, T15, and T2 are battery temperatures that are each reduced by a predetermined temperature (for example, by -1.degree. C. to -4.degree. C.) from the restriction start temperature T11 (.degree. C.). ° C) is set. The battery temperature lower limit usable temperature T2 (° C) is set to a temperature slightly higher than the specified temperature T3 (° C) at which the battery 32 (for example, lithium ion battery etc.) is warned and input / output shutoff is performed. . For example, when the specified temperature T3 (LIB specified temperature T3) (° C) of the battery 32 (lithium ion battery etc.) is -10 ° C to -30 ° C, the usable lower limit temperature T2 (° C) is -6 It is set to ° C to -28 ° C.

  When the battery temperature is higher than the restriction start temperature T11 (° C.), the upper limit rotational speed of the drive motor 21 is set to the normal upper limit rotational speed N1 (rpm) (for example, 3600 rpm) (upper limit) It may be done or it may not be limited. On the other hand, when the battery temperature is a low temperature (first low temperature state) equal to or lower than the restriction start temperature T11 (° C.), the upper limit rotational speed of the drive motor 21 is each battery temperature T12, T13, T14, T15, T2 (° C.) The upper limit rotational speed N2, N3, N4, N5, N6, N7 (rpm) (upper limit value) which is sequentially reduced by about 10% to 15% in steps from the normal upper limit rotational speed N1 (rpm) each time Set to) and restricted.

  For example, when the battery temperature drops to the usable lower limit temperature T2 (° C.), the upper limit rotational speed of the drive motor 21 is reduced to about 30% to 40% of the normal upper limit rotational speed N1 (rpm) The rotational speed N7 (rpm) (minimum upper limit value) is set and limited. When the battery temperature falls below the usable lower limit temperature T2 (° C.) or lower (second low temperature state), the upper limit rotational speed of the drive motor 21 is set to the lowest upper limit rotational speed N7 (rpm) (minimum upper limit value). Set and restricted. The restriction start temperature T11 (° C.) is set as a temperature higher than the specified temperature T3 (° C.). Then, the usable lower limit temperature T2 (° C) is set between the specified temperature T3 (° C) and the restriction start temperature T11 (° C), and the restriction start temperature T11 (° C) and the usable lower limit temperature T2 (° C) , T12 to T15 (° C.) are set. The specified temperature T3 (° C.), the usable lower limit temperature T2 (° C.), the restriction start temperature T11 (° C.), and the battery temperature / upper limit rotational speed information (FIG. 5) are stored in the machine control device 50. Further, as described later, the battery control device 31 (see FIG. 2) enters the battery 32 (see FIG. 2) using the cutoff switch 38 (see FIG. 2) when the battery temperature becomes lower than the specified temperature T3. Shut off the output.

  That is, the upper limit rotational speed of the drive motor 21 is the lowest upper limit rotational speed until the battery temperature drops from the usable lower limit temperature T2 (° C.) to the specified temperature T3 (° C.) and input / output shutoff of the battery device 30 is performed. It is set to N7 (rpm) (minimum upper limit value). Therefore, the machine control device 50 sets the drive motor 21 at the lowest upper limit rotational speed N7 (rpm) (minimum upper limit value) until the battery temperature decreases from the usable lower limit temperature T2 (.degree. C.) to the specified temperature T3 (.degree. C.). It can be driven.

  Returning to FIG. 3, in step S17, the machine control device 50 determines that the temporary target rotational speed obtained in step S13 is higher than the upper limit rotational speed of the drive motor 21 set based on the battery temperature in step S16. A determination process is performed to determine whether the value is large. Then, when it is determined in step S16 that the temporary target rotation speed is equal to or less than the upper limit rotation speed of the drive motor 21 set based on the battery temperature (S17: NO), the machine control device 50 The process proceeds to step S19. On the other hand, when it is determined in step S16 that the temporary target rotation speed is larger than the upper limit rotation speed of the drive motor 21 set based on the battery temperature (S17: YES), the machine control device 50 performs step S18. Go to

  In step S <b> 18, the machine control device 50 stores the upper limit rotation number of the drive motor 21 set based on the battery temperature in step S <b> 16 as the temporary target rotation number. That is, the machine control device 50 stores, in the temporary target rotation speed, the upper limit rotation speed which is stepwise decreased based on the battery temperature. Further, the machine control device 50 obtains and stores, as the temporary target torque, the torque of the drive motor 21 corresponding to the upper limit rotational speed which is stepwise decreased based on the battery temperature.

  Further, when it is determined in step S13 that the normal braking stop request mode is set, regeneration of the normal braking corresponding to the temporary target regenerative force and the upper limit rotational speed which is gradually decreased based on the battery temperature Remember the power. Further, when it is determined in step S13 that the sudden braking stop request mode is set, regeneration of the sudden braking corresponding to the upper limit rotational speed stepwise decreased based on the battery temperature is made to the temporary target regenerative force. Remember the power.

  For example, as shown in FIG. 5, in the case of a battery temperature T13 (° C.) where the battery temperature is about −2 ° C. to −10 ° C. lower than the restriction start temperature T11 (° C.), the upper limit rotational speed N4 of the drive motor 21 ( The rpm) is reduced by about 30% from the normal upper limit rotational speed N1 (rpm). For this reason, the traveling speed of the reach type forklift 10 is reduced to about 5 (km / h) or less from the usual about 8 (km / h) or less. As a result, the torque of the drive motor 21 with respect to the upper limit rotational speed N4 (rpm) also decreases to the same extent, so that the operator feels that the power is insufficient. In addition, since the regenerative power for normal braking and the regenerative power for rapid braking with respect to the upper limit rotational speed N4 (rpm) also decrease to the same extent, the operator who operates the accelerator lever 12 feels as if it stalls. Thereby, the operator can easily recognize that the battery 32 will be in the overdischarged state soon after continuing the work as it is.

  Further, as shown in FIG. 5, for example, in the case where the battery temperature is usable lower limit temperature T2 (° C.) lower by about −5 ° C. to −25 ° C. than restriction start temperature T11 (° C.), the upper limit of drive motor 21 The rotational speed N7 (rpm) is reduced by about 60% from the normal upper limit rotational speed N1 (rpm). For this reason, the traveling speed of the reach type forklift 10 is reduced to about 3 (km / h) or less from the usual about 8 (km / h) or less.

  As a result, since the torque of the drive motor 21 with respect to the upper limit rotational speed N7 (rpm) also decreases to the same extent, the operator experiences extreme power shortage. In addition, since the regenerative power of normal braking and the regenerative power of rapid braking with respect to the upper limit rotational speed N7 (rpm) are reduced to the same extent, the operator who operates the accelerator lever 12 feels as if it stalls greatly. As a result, when the operator continues the work as it is, the battery 32 will be overdischarged soon, and the operator can surely recognize that the reach type forklift 10 will stop.

  Subsequently, in step S19, the machine control device 50 reads the battery temperature acquired in step S14, and determines whether the battery temperature is equal to or lower than the usable lower limit temperature T2 (° C.). When it is determined that the battery temperature is lower than the restriction start temperature T11 (° C.) and higher than the usable lower limit temperature T2 (° C.) (the first low temperature state) (S19: (NO), the machine control device 50 proceeds to step S20.

  In step S20, the machine control device 50 warns that the battery temperature of the battery 32 has become a low temperature equal to or lower than the restriction start temperature T11 (° C.) (for example, 0 ° C. to -5 ° C. or lower). After displaying on the display device 55 and notifying the operator, the process proceeds to step S22 described later. For example, the machine control device 50 displays on the display 55 that “The battery temperature is low. Please move to an external charging place.” And move from the freezer warehouse etc. to an external charging place After prompting the user, the process proceeds to step S22 described later.

  On the other hand, when it is determined in step S19 that the battery temperature is a low temperature equal to or lower than the usable lower limit temperature T2 (° C.) (a second low temperature state) (S19: YES), the machine control device 50 , And proceeds to step S21. In step S21, the machine control device 50 sets the battery temperature of the battery 32 to a low temperature equal to or lower than the usable lower limit temperature T2 (° C.) (eg, -6 ° C. to -28 ° C. or less). After the "stop warning" is displayed on the display device 55 to warn the operator that the input / output of the device 30 is blocked and stopped, the operator is notified, and then the process proceeds to step S22 described later. The “informing” in step S20 and step S21 is not limited to the display on the display device 55, and may be notified by a buzzer or a lamp.

  Subsequently, in step S22, the machine control device 50 stores the operation mode stored in the temporary operation mode in the final operation mode, and stores the rotation direction stored in the temporary rotation direction in the final rotation direction, The rotation speed stored in the temporary target rotation speed is stored in the final target rotation speed, the torque stored in the temporary target torque is stored in the final target torque, and the regenerative force stored in the temporary target regeneration force is final The target regenerative force is stored, and the process proceeds to step S23.

  In step S23, the machine control device 50 transmits motor control information including the final operation mode, the final rotation direction, the final target rotation speed, the final target torque, and the final target regenerative force to the inverter control device 41, and proceeds to step S24. . The process of the inverter control device 41 that has received the motor control information will be described later (see FIG. 7).

  In step S24, the machine control device 50 receives, from the battery control device 31, interruption message information indicating that the input / output is interrupted after X seconds, that is, the power supply of the battery device 30 is interrupted after X seconds. It is determined whether or not. When the machine control device 50 determines that the shutoff message information is not input from the battery control device 31 (S24: NO), the process proceeds to step S26, and the shutoff message information is input from the battery control device 31. If it is determined (S24: YES), the process proceeds to step S25.

  If the process proceeds to step S25, the machine control unit 50 displays a shutoff warning indicating that the input / output of the battery device 30 is shut off and stopped after X seconds, for example, the message “stops after X seconds”. After displaying on the device 55, the first low temperature warning processing is ended. The “warning” in step S25 is not limited to the display on the display device 55, and may be notified by a buzzer or a lamp.

  When the process proceeds to step S26, when the "cut-off warning" is displayed on the display device, the machine control device 50 cancels the display of the "cut-off warning" (disappears the display), and the first low temperature End the warning process.

[Process procedure of the battery control device 31 (FIG. 6)]
Next, an example of the processing procedure of the battery control device 31 will be described using the flowchart shown in FIG. For example, the battery control device 31 starts the process shown in FIG. 6 at predetermined time intervals (for example, several ms to several 10 ms), and advances the process to step S112 when started.

  In step S112, the battery control device 31 determines whether or not the battery temperature of the battery 32 detected using the temperature detection means 37 is equal to or lower than a preset low temperature specified temperature, and determines that the temperature is lower than the predetermined temperature. If it has (S112: YES), the process proceeds to step S117. On the other hand, when it is determined that the temperature is higher than the specified temperature (S112: NO), the battery control device 31 proceeds to step S113.

  When the process proceeds to step S113, the battery control device 31 determines whether the battery voltage is equal to or higher than the overvoltage (overvoltage state), and determines that the battery voltage is equal to or higher than the overvoltage (S113: YES). The process proceeds to step S117. On the other hand, when it is determined that the battery voltage is lower than the overvoltage (not in the overvoltage state) (S113: NO), the battery control device 31 proceeds to step S114.

  If the process proceeds to step S114, the battery control device 31 determines whether the battery voltage is less than or equal to the overdischarge voltage (overdischarge state), and if it is determined that the battery voltage is less than or equal to the overdischarge voltage (S114) : YES), the process proceeds to step S117. On the other hand, when it is determined that the battery voltage is higher than the overdischarge voltage (not in the overdischarge state) (S114: NO), the battery control device 31 proceeds to step S115.

  If the process proceeds to step S115, the battery control device 31 determines whether or not the transmission request information from the machine control device 50 has been received, and if the transmission request information has been received (S115: YES), The process proceeds to step S116. On the other hand, when the transmission request information has not been received (S115: NO), the battery control device 31 ends the process.

  When the process proceeds to step S116, the battery control device 31 transmits battery information including the battery voltage and the battery temperature to the machine control device 50, and ends the processing.

  When the process proceeds to step S117, the battery control device 31 transmits the shutoff message information to the machine control device 50, and the process proceeds to step S118. For example, the battery control device 31 transmits information of the summary "The battery temperature is low. The battery input / output is shut off after X seconds" toward the machine control device 50. In step S25 shown in FIG. 3, the machine control device 50 that has received the shutoff message information notifies a “cutoff warning” based on the information included in the shutoff message information.

  Subsequently, in step S118, the battery control device 31 determines whether transmission of the shutoff message information in step S117 is continued for a predetermined time (for example, about 10 seconds) or more, and continues for a predetermined time or more. If it is (S118: YES), the process proceeds to step S119. On the other hand, when the process has not been continued for the predetermined time or more (S118: NO), the process ends.

  When the process proceeds to step S119, the battery control device 31 cuts off the output of the power from the battery 32 and the input of the power to the battery 32, and ends the processing. In this case, the battery control device 31 controls the cutoff switch 38 shown in FIG. 2 from the conductive state to the open state. When the battery 32 is cut off, the supply of power to the battery control device 31, the inverter control device 41, and the machine control device 50 is stopped, and the operation of the reach type forklift 10 is stopped.

● [Processing procedure of inverter control device 41 (FIG. 7)]
Next, an example of the processing procedure of the inverter control device 41 will be described using the flowchart shown in FIG. For example, the inverter control device 41 starts the process shown in FIG. 7 at predetermined time intervals (for example, several ms to several 10 ms), and advances the process to step S211 when started.

  In step S211, the inverter control device 41 determines whether transmission request information from the machine control device 50 has been received. When the inverter control device 41 determines that the transmission request information is received (S211: YES), the process proceeds to step S212. On the other hand, when it is determined that the transmission request information has not been received (S211: NO), the process proceeds to step S213.

  When the process proceeds to step S212, the inverter control device 41 transmits inverter information including the number of rotations and the rotational direction of the drive motor 21 to the machine control device 50, and the process proceeds to step S213.

  In step S213, the inverter control device 41 determines whether motor control information has been received from the machine control device 50. When the inverter control device 41 determines that the motor control information is received (S213: YES), the process proceeds to step S214. On the other hand, when it is determined that the motor control information has not been received (S213: NO), the process ends.

  In step S214, the inverter control device 41 determines whether the final operation mode included in the received motor control information is the traveling start mode. When the inverter control device 41 determines that the final operation mode is the travel start mode (S214: YES), the process proceeds to step S216 described later. On the other hand, when it is determined that the final operation mode is not the traveling start mode (S214: NO), the process proceeds to step S215.

  In step S215, the inverter control device 41 determines whether the final operation mode included in the received motor control information is the traveling continuation mode. Then, when it is determined that the final operation mode is the traveling continuation mode (S215: YES), the inverter control device 41 proceeds to step S216. On the other hand, when it is determined that the final operation mode included in the received motor control information is not the traveling continuation mode (S215: NO), the inverter control device 41 proceeds to step S217.

  In step S216, the inverter control device 41 drives and controls the drive motor 21 based on the final rotation direction, the final target rotation speed, and the final target torque included in the received motor control information, and ends the processing. .

  In step S217, the inverter control device 41 determines whether the final operation mode included in the received motor control information is the stop request mode. When the inverter control device 41 determines that the final operation mode is the stop request mode (S217: YES), the process proceeds to step S218. On the other hand, when it is determined that the final operation mode included in the received motor control information is not the stop request mode, that is, when it is determined that the final operation mode is the stop mode (S217: NO), the inverter control device 41 proceeds to step S219.

  In step S218, the inverter control device 41 performs regeneration control of the drive motor 21 based on the final rotation direction and the final target regenerative force included in the received motor control information, and ends the process.

In step S219, the inverter control device 41 stops energization of the drive motor 21 and ends the process.

  As described above in detail, in the reach type forklift 10 according to the first embodiment, the machine control device 50 starts the restriction in which the battery temperature of the battery device 30 starts to limit the upper limit rotational speed of the drive motor 21. If it is determined that the temperature has dropped below T11 (° C.), each battery temperature T12, T13, etc. decreased by a predetermined temperature (eg, -1 ° C. to -4 ° C.) from the limit start temperature T11 (° C.) Set T14, T15, and T2 (° C). The battery temperature useable lower limit temperature T2 (° C) is slightly higher than the specified temperature T3 (eg -10 ° C to -30 ° C) at which the battery 32 (eg lithium ion battery etc.) is warned / input / output shut off The temperature is set (for example, -6 ° C to -28 ° C).

  Then, when the battery temperature is a low temperature equal to or less than the restriction start temperature T11 (° C.), the upper limit rotational speed of the drive motor 21 decreases to each battery temperature T12, T13, T14, T15, T2 (° C.) The upper limit rotational speed N2, N3, N4, N5, N6, N7 (rpm) (upper limit value) which is sequentially reduced in steps of approximately 10% to 15% from the normal upper limit rotational speed N1 (rpm) Be done. Then, the upper limit rotational speed of the drive motor 21 is the lowest upper limit rotational speed until the battery temperature drops from the usable lower limit temperature T2 (° C.) to the specified temperature T3 (° C.) and input / output cutoff of the battery device 30 is performed. It is set to N7 (rpm) (minimum upper limit value).

  Therefore, the upper limit rotational speed of the drive motor 21 is the upper limit rotational speed N1 (rpm) each time the battery temperature falls from the restriction start temperature T11 (° C.) to each battery temperature T12, T13, T14, T15, T2 (° C.) From about 10% to 15%. As a result, the torque of the drive motor 21 also decreases stepwise in the same degree, so that the operator feels that the power decreases stepwise. In addition, since the regenerative power of the normal braking and the regenerative power of the sudden braking are reduced to the same extent, the operator who operates the accelerator lever 12 feels as if the vehicle is stalled. Thus, the operator can easily recognize that the battery 32 will be in the overdischarge / overvoltage state eventually when the operation is continued.

  In addition, when the battery temperature of battery 32 falls below usable lower limit temperature T2 (° C.) or less, the drive motor for upper limit rotation number N7 (rpm) decreased by about 60% from the normal upper limit rotation number N1 (rpm) Since the torque of 21 is reduced to the same extent, the operator experiences extreme power shortage. In addition, since the regenerative power of normal braking and the regenerative power of rapid braking with respect to the upper limit rotational speed N7 (rpm) are reduced to the same extent, the operator who operates the accelerator lever 12 feels as if it stalls greatly.

  As a result, when the operator continues the work as it is, the battery 32 will soon be in the overdischarge / overvoltage state (or shut off state), and it can be surely recognized that the reach type forklift 10 will stop. Therefore, it is possible to reliably urge the operator to stop the work and move the reach type forklift 10 to the charging place, and to stop the reach type forklift 10 during the work and to prevent so-called regeneration omission. Can.

  In FIG. 5, as the battery temperature of the battery 32 decreases from the limit start temperature T11 (° C.) to the usable lower limit temperature T2 (° C.), the upper limit rotational speed of the drive motor 21 is set to the normal upper limit rotational speed N1. It may be made to decrease stepwise in six steps or more, from (rpm) to the minimum upper limit rotation number N7 (rpm), or from the normal upper limit rotation number N1 (rpm) to the minimum upper limit rotation number N7 (rpm ) May be lowered linearly.

  As a result, the operator can reliably recognize that the battery 32 is in the overdischarge / overvoltage state if the operation is continued. Therefore, it is possible to reliably urge the operator to stop the work and move the reach type forklift 10 to the charging place, and to stop the reach type forklift 10 during the work and to prevent so-called regeneration omission. Can. Further, by limiting the output (rotational speed) of the drive motor at low temperature, the output from the battery device to the drive motor is limited, and the input from the drive motor to the battery device is limited at the time of regeneration. Therefore, it is possible to suppress the overdischarge / overvoltage of the battery device at the time of low temperature by an easy method without modifying the battery device, and to suppress the battery device from being in the shutoff state.

Second Embodiment (FIGS. 8 to 10)
Next, a reach-type forklift 71 according to a second embodiment will be described based on FIGS. The same reference numerals as in the reach type forklift 10 according to the first embodiment denote the same or corresponding parts as the reach type forklift 10 according to the first embodiment.

  The entire configuration of the reach-type forklift 71 according to the second embodiment is substantially the same as that of the reach-type forklift 10 according to the first embodiment. The control configuration and control process of the reach-type forklift 71 according to the second embodiment are substantially the same as the control configuration and control process of the reach-type forklift 10 according to the first embodiment. However, the machine control device 50 of the reach-type forklift 71 according to the second embodiment is replaced with the above-mentioned "first low temperature warning process" (see FIG. 3), and later described "second low temperature warning process" (see FIG. 8). And the reach type forklift 10 according to the first embodiment. In the flowchart shown in FIG. 8, the steps given the same reference numerals as those in the flowchart shown in FIG. 3 are the same processes as those in the flowchart shown in FIG. The main differences will be explained. In the flowchart shown in FIG. 8, the difference from the flowchart shown in FIG. 3 is that steps S16, S17 and S18 shown in FIG. 3 are changed to steps S16B, S17B and S18B, and the other steps Are identical.

  Here, the “second low temperature warning process” performed by the machine control device 50 of the reach type forklift 71 will be described based on the flowchart shown in FIG. 8. In the program shown in the flowchart in FIG. 8, when the operator activates the reach type forklift 71, the machine control device 50 (control device) operates, for example, at predetermined time intervals (for example, several ms to several 10 ms). The process proceeds to step S11 of the "second low temperature warning process" shown in FIG.

  As shown in FIG. 8, the processing of step S11 to step S15A in the machine control device 50 is the same as the processing of step S11 to step S15A shown in FIG.

  In step S16B, the machine control device 50 stores, in advance, "Battery temperature · upper limit regenerative force information of normal braking (relationship information between battery temperature and upper limit regenerative force of the drive motor 21)" (see Fig. 9) and Upper limit regenerative force of normal braking of the drive motor 21 corresponding to the battery temperature based on the battery temperature / upper limit regenerative force information (relevant information of the battery temperature and the upper limit regenerative force of the drive motor 21) (see FIG. 10) After the upper limit regenerative force of sudden braking is determined and stored, the process proceeds to step S17B.

  Here, “battery temperature / upper limit regenerative force information for normal braking (relationship information between battery temperature and upper limit regenerative force of drive motor 21)” will be described based on FIG. As shown in FIG. 9, each battery temperature T12, T13, T14, T15, T2 (a temperature which is reduced by a predetermined temperature (for example, every -1.degree. C. to -4.degree. C.) from the restriction start temperature T11 (.degree. C.). ° C) is set. The limitation start temperature T11 (° C.), the battery temperatures T12, T13, T14, and T15, the usable lower limit temperature T2 (° C.), and the specified temperature T3 (° C.) are the same as in the first embodiment described above. Omit. The specified temperature T3 (° C.), the usable lower limit temperature T2 (° C.), the restriction start temperature T11 (° C.), and the battery temperature and upper limit regenerative force information for normal braking (FIG. 9) are stored in the machine control device 50 ing.

  Then, when the battery temperature is higher than the restriction start temperature T11 (° C.), the upper limit regeneration force of the normal braking of the drive motor 21 may be set to the normal upper limit regeneration force W11 (upper limit value) And may not be limited. On the other hand, when the battery temperature is a low temperature (first low temperature state) equal to or lower than the restriction start temperature T11 (° C.), the upper limit regenerative force of the normal braking of the drive motor 21 is each battery temperature T12, T13, T14, T15, T2 The upper limit regenerative power W12, W13, W14, W15, W16, W17 (upper limit value) of the normal braking which is sequentially decreased stepwise by about 10% to 15% from the normal upper limit regenerative force W11 each time it decreases to (° C.) Set to) and restricted.

  For example, when the battery temperature drops to the usable lower limit temperature T2 (° C.), the upper limit regenerative force of the normal braking of the drive motor 21 is reduced to about 30% to 40% of the normal upper limit regenerative force W11. Is set and limited to the lowest upper limit regenerative force W17 (minimum upper limit value). Then, when the battery temperature drops to the usable lower limit temperature T2 (° C.) or lower (second low temperature state), the upper limit regenerative force of the normal braking of the drive motor 21 is set to the minimum upper limit regenerative force W17 (minimum upper limit value). Set and restricted.

  That is, the upper limit regenerative force of the normal braking of the drive motor 21 is at least the minimum until the battery temperature drops from the usable lower limit temperature T2 (.degree. C.) to the specified temperature T.sub.3 (.degree. C.) and input / output shutoff of the battery device 30 is performed. The upper limit regenerative force W17 (minimum upper limit value) is set. Therefore, the machine control device 50 sets the reach type forklift 71 to the minimum upper limit regenerative force W17 (minimum upper limit value) of normal braking until the battery temperature decreases from the usable lower limit temperature T2 (° C) to the specified temperature T3 (° C). Can be braked.

  Next, “shatter braking battery temperature / upper limit regenerative force information (relationship information between battery temperature and upper limit regenerative force of drive motor 21)” will be described based on FIG. As shown in FIG. 10, when the battery temperature is higher than the restriction start temperature T11 (° C.), the upper limit regenerative force of the rapid braking of the drive motor 21 is set to the normal upper limit regenerative force W21 (upper limit value). It may be done or it may not be limited. On the other hand, when the battery temperature is a low temperature (first low temperature state) equal to or lower than the restriction start temperature T11 (° C.), the upper limit regenerative force of the rapid braking of the drive motor 21 is each battery temperature T12, T13, T14, T15, T2 The upper limit regenerative force W22, W23, W24, W25, W26, W27 (upper limit value) of the rapid braking which gradually decreases by about 10% to 15% step by step from the normal upper limit regenerative force W21 each time it decreases to (° C.) Set to) and restricted. The limitation start temperature T11 (° C.), the battery temperatures T12, T13, T14, and T15, the usable lower limit temperature T2 (° C.), and the specified temperature T3 (° C.) are the same as in the first embodiment described above. Omit. The specified temperature T3 (° C.), the usable lower limit temperature T2 (° C.), the restriction start temperature T11 (° C.), the battery temperature and the upper limit regenerative force information of the rapid braking (FIG. 10) are stored in the machine control device 50 ing.

  For example, when the battery temperature drops to the usable lower limit temperature T2 (° C.), the upper limit regenerative force of the rapid braking of the drive motor 21 decreases to about 30% to 40% of the normal upper limit regenerative force W21. Is set and limited to the lowest upper limit regenerative force W27 (minimum upper limit value). Then, when the battery temperature drops to the usable lower limit temperature T2 (° C.) or less (second low temperature state), the upper limit regenerative force of the rapid braking of the drive motor 21 becomes the lowest upper limit regenerative force W27 (minimum upper limit value). Set and restricted.

  That is, the upper limit regenerative force of the rapid braking of the drive motor 21 is the minimum until the battery temperature drops from the usable lower limit temperature T2 (° C.) to the specified temperature T 3 (° C.) and input / output shutoff of the battery device 30 is performed. The upper limit regenerative force W27 (minimum upper limit value) is set. Accordingly, the machine control device 50 controls the drive motor 21 with the minimum upper limit regenerative force W27 (minimum upper limit value) of rapid braking until the battery temperature drops from the usable lower limit temperature T2 (° C) to the specified temperature T3 (° C). It can be braked.

  Returning to FIG. 8, in step S17B, when the temporary target regenerative force determined in step S13 is the regenerative force of the normal braking, the temporary target regenerative force is the process in step S16B. A determination process is performed to determine whether or not the upper limit regenerative force of normal braking of the drive motor 21 set based on the battery temperature is larger. When it is determined in step S16B that the temporary target regenerative force is equal to or less than the upper limit regenerative force of the normal braking of the drive motor 21 set based on the battery temperature (S17B: NO), the machine control device 50 The process proceeds to step S19 described later. On the other hand, when it is determined in step S16B that the temporary target regeneration force is larger than the upper limit regeneration force of the normal braking of the drive motor 21 set based on the battery temperature (S17B: YES), the machine control device 50 The process proceeds to step S18B.

  Further, when the temporary target regeneration force obtained in step S13 is the rapid braking regeneration force, the machine control device 50 sets the temporary target regeneration force based on the battery temperature in step S16B. A determination process is performed to determine whether the upper limit regenerative force of the sudden braking of the drive motor 21 is larger. When it is determined in step S16B that the temporary target regenerative force is less than or equal to the upper limit regenerative force of the rapid braking of the drive motor 21 set based on the battery temperature (S17B: NO), the machine control device 50 The process proceeds to step S19 described later. On the other hand, when it is determined that the temporary target regeneration force is larger than the upper limit regeneration force of the rapid braking of the drive motor 21 set based on the battery temperature in step S16B (S17B: YES), the machine control device 50 The process proceeds to step S18B.

  In step S18B, when the temporary target regenerative force determined in step S13 is the regenerative force of the normal braking in step S18B, the temporary target regenerative force is based on the battery temperature in step S16B. The set upper limit regenerative force of the normal braking of the drive motor 21 is stored. That is, the machine control device 50 stores, as the temporary target regeneration force, the upper limit regeneration force of the normal braking which is stepwise decreased based on the battery temperature. On the other hand, when the temporary target regeneration force obtained in step S13 is the rapid braking regeneration force, the machine control device 50 sets the temporary target regeneration force based on the battery temperature in step S16B. The upper limit regenerative force of the rapid braking of the drive motor 21 is stored. That is, the machine control device 50 stores, as the temporary target regeneration force, the upper limit regeneration force of the rapid braking which is stepwise decreased based on the battery temperature.

  Further, the machine control device 50 obtains and stores, as the temporary target torque, the torque of the drive motor 21 corresponding to the temporary target regenerative power set based on the battery temperature. Further, the machine control device 50 obtains and stores the number of rotations of the drive motor 21 corresponding to the temporary target torque as the temporary target rotation number. Thereafter, the machine control device 50 proceeds to step S19.

  For example, as shown in FIG. 9, in the case of a battery temperature T13 (° C.) where the battery temperature is about −2 ° C. to −10 ° C. lower than the restriction start temperature T11 (° C.), upper limit regeneration of normal braking of the drive motor 21 The force W14 is reduced by about 30% from the normal upper limit regenerative force W11. Further, as shown in FIG. 10, in the case of a battery temperature T13 (° C.) where the battery temperature is approximately −2 ° C. to −10 ° C. lower than the restriction start temperature T11 (° C.), the upper limit regeneration of rapid braking of the drive motor 21 The force W24 is reduced by about 30% from the normal upper limit regenerative force W21.

  As a result, since the braking torque of the drive motor 21 for the upper braking power W14 of normal braking of the reach type forklift 71 or the upper braking power W24 of sudden braking is also reduced to the same extent, the operator operating the accelerator lever 12 , To experience the lack of braking power. As a result, the operator can easily recognize that the battery 32 will be in the overdischarge / overvoltage state eventually when the work is continued.

  Further, as shown in FIG. 9, for example, when the battery temperature is lower than the restriction start temperature T11 (.degree. C.) by about -5.degree. C. to -25.degree. C., the usable lower limit temperature T.sub.2 (.degree. C.) The upper limit regenerative force W17 for braking is reduced by about 60% from the normal upper limit regenerative force W11. Further, as shown in FIG. 10, in the case where the battery temperature is lower than the restriction start temperature T11 (° C.) by about -5 ° C. to -25 ° C. and the usable lower limit temperature T2 (° C.) The upper limit regenerative force W27 is reduced by about 60% from the normal upper limit regenerative force W21.

  As a result, since the braking torque of the drive motor 21 for the upper braking power W17 for normal braking of the reach type forklift 71 or the upper braking power W27 for sudden braking is also reduced to the same extent, the operator operating the accelerator lever 12 , You feel as if the lack of braking power has surged. As a result, the operator can recognize that the battery 32 will be overdischarged / overvoltage soon and the reach type forklift 71 will stop when the work continues.

  Then, since the process of step S19-step S26 shown in FIG. 8 is the same as the process of step S19-S26 shown in FIG. 3, description is abbreviate | omitted.

  As described above in detail, in the reach-type forklift 71 according to the second embodiment, the machine control device 50 determines that the battery temperature of the battery device 30 has fallen below the restriction start temperature T11 (° C.) In this case, each time battery temperatures T12, T13, T14, T15, and T2 (° C.) lower by a predetermined temperature (for example, -1 ° C. to -4 ° C.) from the restriction start temperature T11 (° C.) The upper limit regenerative power of the normal braking and the rapid braking of the motor 21 is gradually reduced by about 10% to 15% and limited.

  Thus, the battery temperatures T12 and T13 at which the braking torques for the normal braking and the sudden braking of the reach type forklift 71 are decreased by a predetermined temperature (for example, by -1.degree. C. to -4.degree. C.) from the restriction start temperature T11 (.degree. C.) Each time T14, T15, and T2 (° C.) are reached, the braking operation can be limited and hard to use by reducing the speed to approximately 10% to 15%. As a result, at the time of low temperature work, if the work is continued as it is, the accelerator lever 12 is operated such that the battery 32 will be in the overdischarge / overvoltage state (or shut off state) soon and the reach type forklift 71 will stop. An operator can be made to recognize reliably. Therefore, it is possible to reliably urge the operator to stop the work and move the reach type forklift 71 to the charging place, and to stop the reach type forklift 71 during the work and to prevent so-called regeneration omission. Can.

  In FIG. 9, as the battery temperature of the battery 32 decreases from the restriction start temperature T11 (.degree. C.) to the usable lower limit temperature T.sub.2 (.degree. C.), the upper limit regenerative force of normal braking is changed from the normal upper limit regenerative force W11. The maximum upper limit regenerative force W17 may be reduced stepwise in six or more stages, or may be gradually reduced linearly from the normal upper limit regenerative force W11 to the minimum upper limit regenerative force W17. Good.

  Further, in FIG. 10, as the battery temperature of the battery 32 decreases from the restriction start temperature T11 (° C.) to the usable lower limit temperature T2 (° C.), the upper limit regenerative force of rapid braking is obtained from the normal upper limit regenerative force W21. The maximum upper limit regenerative force W27 may be reduced stepwise in six or more steps, or may be gradually reduced linearly from the normal upper limit regenerative force W21 to the minimum upper limit regenerative force W27. Good.

  Thus, the operator can easily recognize that the battery 32 is in the overdischarge / overvoltage state if the operation is continued. Therefore, it is possible to reliably urge the operator to stop the work and move the reach type forklift 71 to the charging place, and to stop the reach type forklift 71 during the work and to prevent so-called regeneration omission. Can. In addition, by limiting the regenerative force of the drive motor at low temperatures, the overvoltage of the battery device at low temperatures can be suppressed by an easy method without touching the battery device, and the battery device can be prevented from being disconnected. can do.

Third Embodiment (FIGS. 11 and 12)
Next, a reach type forklift 81 according to a third embodiment will be described based on FIGS. 11 and 12. The same reference numerals as in the reach type forklift 10 according to the first embodiment denote the same or corresponding parts as the reach type forklift 10 according to the first embodiment.

  The entire configuration of the reach-type forklift 81 according to the third embodiment is substantially the same as the reach-type forklift 10 according to the first embodiment. The control configuration and control process of the reach-type forklift 81 according to the third embodiment are substantially the same as the control configuration and control process of the reach-type forklift 10 according to the first embodiment. However, the machine control device 50 of the reach type forklift 81 according to the third embodiment is replaced with the above-mentioned "first low temperature warning process" (see Fig. 3), and "third low temperature warning process" described later (see Fig. 11). And the reach type forklift 10 according to the first embodiment. In the flowchart shown in FIG. 11, the steps given the same reference numerals as those in the flowchart shown in FIG. 3 are the same processes as those in the flowchart shown in FIG. The main differences will be explained. In the flowchart shown in FIG. 11, the difference from the flowchart shown in FIG. 3 is that steps S16, S17 and S18 shown in FIG. 3 are changed to steps S16C and S18C, and the other steps are the same. It is.

  Here, the “third low temperature warning process” executed by the machine control device 50 of the reach type forklift 81 will be described based on the flowchart shown in FIG. Note that when the operator activates the reach-type forklift 81, the machine control device 50 (control device) performs, for example, at predetermined time intervals (for example, intervals of several ms to several 10 ms) when the operator activates the reach type forklift 81. The process proceeds to step S11 of the "third low temperature warning process" shown in FIG.

  As shown in FIG. 11, the processing of step S11 to step S15A in the machine control device 50 is the same as the processing of step S11 to step S15A shown in FIG.

  In step S16C, machine control device 50 stores the battery based on "Battery temperature · accelerator opening ratio information (relationship information between battery temperature and opening ratio of accelerator lever 12)" (see Fig. 12). Determine the accelerator opening ratio corresponding to the temperature. Then, the machine control device 50 adds a value obtained by integrating the accelerator opening ratio to the inclination angle (operation amount) of the accelerator lever 12 input from the operation state detection means 12A, to the accelerator opening (acceleration operation recognition amount) After storing as, the process proceeds to step S18C.

  Here, “battery temperature / accelerator opening ratio information (relationship information between the battery temperature and the opening ratio of the accelerator lever 12)” will be described based on FIG. As shown in FIG. 12, the battery temperatures T12, T13, T14, T15, and T2 (which are each reduced by a predetermined temperature (for example, every -1 ° C. to -4 ° C.) from the restriction start temperature T11 (° C. ° C) is set. The limitation start temperature T11 (° C.), the battery temperatures T12, T13, T14, and T15, the usable lower limit temperature T2 (° C.), and the specified temperature T3 (° C.) are the same as in the first embodiment described above. Omit. The specified temperature T3 (° C.), the usable lower limit temperature T2 (° C.), the restriction start temperature T11 (° C.), the battery temperature / accelerator opening ratio information (FIG. 12) are stored in the machine control device 50. .

  When the battery temperature is higher than the restriction start temperature T11 (° C.), the accelerator opening ratio is set to 100% (the upper limit value) of the normal, and is not restricted. As a result, when the battery temperature is higher than the restriction start temperature T11 (° C.), the machine control device 50 sets the inclination angle of the accelerator lever 12 input from the operation state detection means 12A It stores as an accelerator operation recognition amount).

  On the other hand, when the battery temperature is a low temperature (first low temperature state) equal to or lower than the restriction start temperature T11 (° C.), the accelerator opening ratio decreases to each battery temperature T12, T13, T14, T15, T2 (° C.) Each time the accelerator opening ratio P1, P2, P3, P4, P5, P6 (%) (upper limit value) decreases gradually in steps of approximately 10 (%) to 15 (%) from the normal 100 (%) Set to and restricted.

  For example, when the battery temperature T13 (° C.) lower by about −2 ° C. to −10 ° C. than the restriction start temperature T11 (° C.), the accelerator opening ratio is about 100 (%) to about 70 (%) ) Is set and limited to the accelerator opening ratio P3 (%) that has dropped to a certain extent. As a result, when the battery temperature falls to the battery temperature T13 (° C.), the machine control device 50 sets the accelerator opening ratio P3 (%) to the inclination angle of the accelerator lever 12 input from the operation state detection means 12A. Is integrated, and a value of about 70 (%) of the inclination angle of the accelerator lever 12 is stored as an accelerator opening degree (acceleration operation recognition amount).

  For example, when the battery temperature falls to the lower limit usable temperature T2 (° C.), the accelerator opening ratio decreases from about 100 (%) to about 30 (%) to 40 (%). P6 (%) (minimum upper limit) is set and limited. As a result, when the battery temperature falls to the usable lower limit temperature T2 (° C.), the machine control device 50 sets the accelerator opening ratio P6 to the inclination angle of the accelerator lever 12 input from the operation state detection means 12A. %) Is accumulated, and a value of about 30 (%) to 40 (%) of the inclination angle of the accelerator lever 12 is stored as an accelerator opening degree (acceleration operation recognition amount).

  When the battery temperature falls to a low temperature (second low temperature state) lower than the usable lower limit temperature T2 (° C.), the accelerator opening ratio is set to the accelerator opening ratio P6 (%) (minimum upper limit value) And limited. That is, the accelerator opening ratio is the accelerator opening ratio P6 (%) until the battery temperature drops from the usable lower limit temperature T2 (.degree. C.) to the specified temperature T.sub.3 (.degree. C.) and input / output shutoff of the battery device 30 is performed. ) (Minimum upper limit) is set and limited. As a result, the machine control device 50 measures the inclination angle of the accelerator lever 12 input from the operation state detection means 12A until the battery temperature decreases from the usable lower limit temperature T2 (.degree. C.) to the specified temperature T.sub.3 (.degree. C.). A value of 30 (%) to 40 (%) is stored as the accelerator opening degree (acceleration operation recognition amount).

  Referring back to FIG. 11, in step S18C, the machine control device 50 reads out the accelerator opening (acceleration operation recognition amount) stored in step S16C, and then the accelerator opening (acceleration operation recognition amount) The rotational speed of the drive motor 21 is calculated from the speed of the reach-type forklift 81 at the normal time corresponding to the inclination angle as the inclination angle of the accelerator lever 12 in the above. Then, the machine control device 50 stores the calculated rotational speed of the drive motor 21 as the temporary target rotational speed. That is, the machine control device 50 obtains the accelerator opening degree (acceleration operation recognition amount) corresponding to the accelerator opening degree ratio lowered stepwise based on the battery temperature, and based on the accelerator opening degree (acceleration operation recognition amount) The number of rotations of the drive motor 21 is obtained and stored in the temporary target number of rotations.

  Further, the machine control device 50 obtains and stores, as the temporary target torque, the torque of the drive motor 21 corresponding to the temporary target rotational speed set based on the battery temperature. Further, when the machine control device 50 determines that the normal braking stop request mode is set in step S13, the temporary target regenerative force corresponds to the normal braking regenerative force corresponding to the temporary target rotational speed. Seek and store. If it is determined in step S13 that the sudden braking stop request mode is selected, the temporary target regenerative force is determined and stored as the rapid braking regenerative force corresponding to the temporary target rotational speed. Thereafter, machine control device 50 proceeds to step S18C.

  Here, as described above, for example, in the case of the battery temperature T13 (° C.) where the battery temperature is approximately −2 ° C. to −10 ° C. lower than the restriction start temperature T11 (° C.) Since the value of 70 (%) is stored as the accelerator opening degree (acceleration operation recognition amount), the temporary target rotational speed of the drive motor 21 decreases by about 30% from that at normal time. For this reason, the traveling speed of the reach type forklift 81 is reduced to about 5 (km / h) or less from the usual about 8 (km / h) or less.

  As a result, since the provisional target torque of the drive motor 21 is also reduced to the same extent as in the normal state, the operator experiences a lack of power. In addition, since the temporary target regeneration force with respect to the temporary target rotation speed is also reduced to the same extent as in the normal state, the operator who operates the accelerator lever 12 feels as if the vehicle is stalled. Thereby, the operator can easily recognize that the battery 32 will be in the overdischarged state soon after continuing the work as it is.

  Further, as described above, for example, when the battery temperature drops to the usable lower limit temperature T2 (° C.) lower than the restriction start temperature T11 (° C.) by about -5 ° C. to -25 ° C. Since a value of about 30 (%) to 40 (%) of the angle is stored as the accelerator opening (acceleration operation recognition amount), the provisional target rotational speed of the drive motor 21 decreases by about 60% from the normal time. . For this reason, the traveling speed of the reach type forklift 81 is reduced to about 3 (km / h) or less from the usual about 8 (km / h) or less.

  As a result, since the temporary target torque of the drive motor 21 is also reduced to the same extent as in the normal state, the operator experiences extreme power shortage. Further, since the temporary target regeneration force with respect to the temporary target rotation speed is also reduced to the same extent as in the normal time, the operator who operates the accelerator lever 12 feels as if the vehicle stalled greatly. As a result, when the operator continues the work as it is, the operator can surely recognize that the battery 32 will be in the overdischarge / overvoltage state soon and the reach type forklift 81 will stop.

  Then, since the process of step S19-step S26 shown in FIG. 11 is the same as the process of step S19-S26 shown in FIG. 3, description is abbreviate | omitted.

  As described above in detail, in the reach type forklift 81 according to the third embodiment, the machine control device 50 determines that the battery temperature of the battery device 30 has fallen below the restriction start temperature T11 (° C.) In this case, each time battery temperatures T12, T13, T14, T15, and T2 (° C.) lower by a predetermined temperature (for example, -1 ° C. to -4 ° C.) from the restriction start temperature T11 (° C.) The provisional target rotational speed, the provisional target torque, and the provisional target regenerative force of the drive motor 21 corresponding to the inclination angle of the lever 12 are sequentially decreased stepwise by about 10 (%) to 15 (%) from 100 (%) , Limited.

  As a result, each battery temperature T12 at which the traveling speed corresponding to the inclination angle of the accelerator lever 12 of the reach type forklift 81 is decreased by a predetermined temperature (for example, by -1.degree. C. to -4.degree. C.) from the restriction start temperature T11 (.degree. C.) , T13, T15, and T2 (° C.) are sequentially reduced stepwise from 100 (%) to about 10 (%) to 15 (%) and limited. For this reason, the operator experiences a lack of power.

  In addition, the braking force of reach type forklift 81 is also lower than the limit start temperature T11 (° C.) by a predetermined temperature (for example, by -1 ° C. to -4 ° C.) at each battery temperature T12, T13, T14. , T15, and T2 (° C.), it gradually decreases in steps of 100 (%) to about 10 (%) to 15 (%). For this reason, the operator operating the accelerator lever 12 feels as if the vehicle is stalled. As a result, at the time of low temperature operation, when the operation is continued as it is, the operator can easily recognize that the battery 32 will be in the overdischarge / overvoltage state eventually.

  In addition, when the battery temperature of the battery 32 decreases to the usable lower limit temperature T 2 (° C.) or less, the traveling speed corresponding to the inclination angle of the accelerator lever 12 of the reach-type forklift 81 is approx. It falls to 30 (%)-40 (%). For this reason, the operator who is operating the accelerator lever 12 experiences extreme power shortage. Further, since the braking force of the reach type forklift 81 is also reduced to the same extent as in the normal state, the operator who operates the accelerator lever 12 feels as if the vehicle stalled greatly.

  As a result, at the time of low temperature work, if the work is continued as it is, the battery 32 will be in the overdischarge / overvoltage state (or shut off state) soon and the accelerator lever 12 is operated to stop the reach type forklift 81 An operator can be made to recognize reliably. Therefore, it is possible to reliably prompt the operator to move the reach type forklift 81 to the charging place by stopping the operation, and to stop the reach type forklift 81 during the operation or to prevent so-called regeneration failure. Can.

  In FIG. 12, as the battery temperature of battery 32 decreases from restriction start temperature T11 (.degree. C.) to usable lower limit temperature T.sub.2 (.degree. C.), the accelerator opening ratio is 100% to the normal upper limit lower limit. The accelerator opening ratio P6 (%) may be decreased stepwise in six or more steps, or linearly from the usual 100 (%) to the lowest upper limit accelerator opening ratio P6 (%) It may be made to decrease gradually.

  Thus, the operator can easily recognize that the battery 32 is in the overdischarged state if the operation is continued. Therefore, it is possible to reliably prompt the operator to move the reach type forklift 81 to the charging place by stopping the operation, and to stop the reach type forklift 81 during the operation or to prevent so-called regeneration failure. Can. In addition, by controlling the drive motor with the accelerator recognition operation amount recognized to decrease the actual operation amount of the accelerator lever at low temperature, the output from the battery device to the drive motor is limited, and at the time of regeneration Limit the input from the drive motor to the battery device. Therefore, it is possible to suppress the overdischarge / overvoltage of the battery device at the time of low temperature by an easy method without modifying the battery device, and to suppress the battery device from being in the shutoff state.

  The battery-powered industrial vehicle of the present invention is not limited to the configurations, structures, appearances, shapes, processing procedures, and the like described in the first to third embodiments, and the scope of the present invention is not changed. Various modifications, improvements, additions, and deletions are possible. In the following description, the same reference numerals as those of the reach-type forklift 10 according to the first embodiment of FIGS. 1 to 7 denote the same or corresponding parts as those of the reach-type forklift 10 according to the first embodiment. It shows the part.

  Further, the battery type industrial vehicle of the present invention is not limited to the reach type forklifts 10, 71, 81 described in the first to third embodiments, and a battery device and a drive motor can be used as a power source for traveling. It can be applied to a variety of battery-powered industrial vehicles such as electric powered vehicles capable of towing tow at the factory, airport, port, etc., and electric forklifts having a pair of forks used for lifting luggage. is there. In the first to third embodiments, the control of the drive motor for traveling has been described as an example, but the present invention can be applied to the control of a drive motor for cargo handling. Therefore, as the drive motor in various battery-type industrial vehicles having a drive motor for traveling, or each drive motor for traveling and cargo handling, or a driving motor for cargo handling, the first to third embodiments have been described. The control of the drive motor described in the third embodiment can be applied. In the description of the first to third embodiments, the accelerator lever 12 is described as an example of a so-called accelerator that instructs the operation of the drive motor for traveling, but instructs the operation of the drive motor for cargo handling. It can be applied as a cargo handling lever. In other words, the accelerator lever is a lever that can indicate the speed (vehicle speed) of the battery-powered industrial vehicle or the speed (operating speed) of the movable part (loading operation unit) of the battery-powered industrial vehicle by the operation amount.

  Although the example which comprised the battery apparatus 30 by the lithium ion battery was demonstrated by description of the said 1st Embodiment-3rd Embodiment, it is not limited to a lithium ion battery, Various kinds of batteries (for example, a nickel hydrogen battery etc.) ) May constitute the battery device 30.

  In the description of the first to third embodiments, an example of a configuration having three control devices of the machine control device 50, the battery control device 31, and the inverter control device 41 has been described. The devices may be combined into one control device, or may be configured of two or more control devices.

  Further, various information such as motor control information is not limited to the respective information described in the first to third embodiments. For example, the final target vehicle speed may be added to the motor control information.

  Further, the above (≧), the following (≦), the larger (>), the less than (<), etc. may or may not include the equal sign. The numerical values used in the description of the first to third embodiments are merely examples, and the present invention is not limited to these numerical values.

10, 71, 81 reach type forklift (battery operated industrial vehicle)
12 accelerator lever 12A operation state detection means 21 drive motor 22 gear 23 motor rotation detection means 30 battery device 31 battery control device 32 battery 33 battery module unit 34 battery module 35 module controller 36 battery cell 37 temperature detection means 38 shut off switch 40 inverter device 41 inverter control device 42 inverter 43 inverter circuit 50 machine control device (control device)
55 Display Device 61 Operation Mode Table T31, T41, T53, T54 Communication Line

Claims (8)

A battery-powered industrial vehicle comprising a battery device and a drive motor as power sources, comprising:
The drive motor,
The battery device outputs electric power at the time of driving operation of the drive motor and receives electric power at the time of regenerative operation of the drive motor;
Temperature detection means for detecting the temperature of the battery in the battery device;
A control device configured to control the output of the drive motor to be limited according to the temperature of the battery when the temperature of the battery detected by the temperature detection means is in a first low temperature state equal to or lower than a predetermined limit start temperature ,
Equipped with
Battery-powered industrial vehicle. In the battery type industrial vehicle according to claim 1,
The output of the drive motor limited from the control device is the number of rotations of the drive motor or the torque of the drive motor.
Battery-powered industrial vehicle. A battery-powered industrial vehicle comprising a battery device and a drive motor as power sources, comprising:
The drive motor,
The battery device outputs electric power at the time of driving operation of the drive motor and receives electric power at the time of regenerative operation of the drive motor;
Temperature detection means for detecting the temperature of the battery in the battery device;
When the temperature of the battery detected by the temperature detecting means is in the first low temperature state equal to or lower than a predetermined limit start temperature, control is performed to limit the regenerative force by the regenerative operation of the drive motor according to the temperature of the battery Controlling device,
Equipped with
Battery-powered industrial vehicle. A battery-powered industrial vehicle comprising a battery device and a drive motor as power sources, comprising:
The drive motor,
The battery device outputs electric power at the time of driving operation of the drive motor and receives electric power at the time of regenerative operation of the drive motor;
Temperature detection means for detecting the temperature of the battery in the battery device;
An accelerator lever capable of indicating the speed of the battery-powered industrial vehicle or the movable part of the battery-powered industrial vehicle by an operation amount;
Operation state detection means for detecting the operation state of the accelerator lever;
A control device that controls an output of the drive motor according to an accelerator recognition operation amount which is the operation amount of the accelerator lever recognized based on a detection signal from the operation state detection unit;
Equipped with
The control device limits the accelerator recognition operation amount in accordance with the temperature of the battery when the temperature of the battery detected by the temperature detection means is in the first low temperature state equal to or lower than a predetermined limit start temperature. Controlling the output of the drive motor based on the detected accelerator operation amount;
Battery-powered industrial vehicle. In the battery type industrial vehicle as described in any one of Claims 1-4,
The control device gradually reduces the upper limit value of the control amount to be limited according to the temperature of the battery when the first low temperature state is, as the temperature of the battery decreases from the predetermined limitation start temperature. Control to set,
Battery-powered industrial vehicle. In the battery type industrial vehicle as described in any one of Claims 1-4,
The control device decreases the upper limit value of the control amount to be limited according to the temperature of the battery in the first low temperature state in a stepwise manner as the temperature of the battery decreases from the predetermined limit start temperature. Control to set
Battery-powered industrial vehicle. The battery-powered industrial vehicle according to any one of claims 1 to 6,
When the temperature detected by the temperature detection means is equal to or less than a specified temperature preset as a temperature lower than the predetermined limit start temperature, the battery device outputs power from itself and inputs power to itself. Shut off
The control device is configured such that the temperature of the battery detected by the temperature detection means is lower than the predetermined limit start temperature, and is lower than a predetermined usable lower limit temperature higher than the specified temperature to the specified temperature. The upper limit value of the control amount to be limited according to the temperature of the battery is controlled to be set to the lowest upper limit value when the temperature is low.
Battery-powered industrial vehicle. In the battery-powered industrial vehicle according to any one of claims 1 to 7,
The battery type industrial vehicle is
An electric forklift with a fork used to lift the load,
Electric powered vehicles that can tow the tow,
Including
The drive motor for traveling, or the drive motor for traveling and cargo handling, or the driving motor for cargo handling,
Battery-powered industrial vehicle.

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