JP5245927B2 - Control system for hybrid forklift - Google Patents

Description

  The present invention relates to a control system for a hybrid forklift.

  In recent years, various hybrid automobiles and forklifts that include an internal combustion engine and a motor generator as drive sources have been proposed. In such a hybrid type vehicle, the driving power of the internal combustion engine and the motor generator is combined in accordance with the traveling state of the vehicle, thereby improving the fuel consumption rate and emission performance while ensuring sufficient vehicle power performance. It can be made to. An example of such a hybrid vehicle control system is disclosed in Patent Document 1.

  In Patent Document 1, a control system of a hybrid electric vehicle (hereinafter referred to as HEV (Hybrid Electric Vehicle)) includes an HCM (Hybrid Controller Module) that is a higher-level control unit that performs integrated control of the vehicle. The HEV control system includes an ECM (Engine Controller Module) for controlling the engine, an M / C (Motor Controller) for controlling the motor, and an ATCU (Automatic Transmission Control Unit) for issuing a shift control command to the transmission. A control unit lower than the HCM is provided. The HCM and each control unit (ECM, M / C, ATCU) are communicably connected via a serial communication bus. The HCM calculates a command to each control unit from various signals, and outputs a control command based on the calculation result to each lower control unit via the serial communication bus. As a result of each control unit controlling the engine, motor, and transmission according to the control command, the HEV can be operated in an optimum state.

  In addition, in a control system having upper and lower control units, if either the upper or lower control unit fails, the lower control unit may not be controlled, so the HEV stops running. Resulting in. However, the control system of Patent Document 1 has a fail-safe function for preventing the vehicle from stopping.

  In order to realize this fail-safe function, the HCM of the control system in Patent Document 1 includes a part of the functions installed in each control unit, and the HCM is an ECU failure control in addition to the HEV integrated control. Can be executed. The HCM exchanges the input information and output information of each control unit with the control information of each control unit in the control of the HCM ECU through the serial communication bus, and receives information from each control unit. HCM is collating. As a result of this collation, if the information from each control unit is different from the internal calculation value of the HCM, it is determined that the hardware (CPU or the like) of each control unit has failed. After the failure determination, the HCM controls the control unit to be controlled by the fail-safe function, so that the HCM realizes a function instead of the control unit, and the vehicle can travel.

JP 2006-335180 A

  However, in the control system of the hybrid electric vehicle of Patent Document 1, in order to shift to the fail-safe function when a control unit failure occurs, information from each control unit via the serial communication bus and when the ECU of the HCM fails The control information of each control unit is always checked in the control. And since the collation of this information is performed by both the HCM and each control unit performing internal calculations in synchronization, the control by the control system is complicated. Further, since the forklift performs traveling and cargo handling work, if the control system having the fail-safe function disclosed in Patent Document 1 is used for the forklift, the control may be further complicated.

  An object of the present invention is to provide a control system for a hybrid forklift that can simplify control in the hybrid forklift.

  In order to achieve the above object, the invention described in claim 1 is characterized in that the power generated by the motor generator is performed while running and cargo handling work using the power of at least one of the internal combustion engine and the motor generator. Control system for a hybrid forklift having a battery that can store electric power and supply electric power to the motor generator, and controls a drive of the motor generator used to perform the cargo handling operation A cargo handling control unit that computes a command required for cargo handling work, and a hybrid control unit that performs integrated control of the hybrid forklift and has a computing function of the cargo handling control unit, the hybrid control unit and the cargo handling Communication with the control unit is possible In this state, input information necessary for the cargo handling operation input to the cargo handling control unit is input from the cargo handling control unit to the hybrid control unit, so that the hybrid control unit calculates a command necessary for the cargo handling operation. On the other hand, when the hybrid control unit and the cargo handling control unit cannot communicate with each other, the cargo handling control unit executes a fail-safe function for calculating a command necessary for the cargo handling operation.

  According to the present invention, when the hybrid control unit and the cargo handling control unit become unable to communicate with each other, the control system performs a fail-safe function, and the cargo handling control unit executes a command calculation for cargo handling control, while the hybrid control unit Then, command calculation is not performed. Therefore, in order to enable execution of the fail-safe function, as in Patent Document 1, the hybrid control unit and the cargo handling control unit execute internal calculations synchronously and compare the calculation results, Control by the control system can be simplified. As a result, the control can be simplified as compared with the case where the control system having the fail-safe function disclosed in Patent Document 1 is used for the forklift that performs traveling and cargo handling work.

  According to a second aspect of the present invention, in the first aspect of the invention, when the hybrid control unit and the cargo handling control unit can communicate with each other, the calculation function of the cargo handling control unit is stopped. The gist.

  According to the present invention, when the hybrid control unit and the cargo handling control unit are in a communicable state, the computation function of the cargo handling control unit is stopped among the computation functions mounted on the hybrid control unit and the cargo handling control unit. By doing so, it is possible to eliminate redundant useless control. Therefore, the control in the hybrid forklift can be further simplified.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the hybrid control unit may be configured such that the hybrid control unit does not communicate between the hybrid control unit and the cargo handling control unit. The gist of the invention is to control the driving of the vehicle so that it is stopped or constant, and to cause the battery to store or output the surplus or deficiency of the energy required for the cargo handling work in the hybrid forklift from the battery.

  If communication between the hybrid control unit and the cargo handling control unit becomes impossible, the hybrid control unit cannot operate the internal combustion engine along the minimum fuel consumption curve in consideration of the energy required for the cargo handling operation. . Therefore, since the hybrid control unit controls the internal combustion engine in a state where energy information necessary for the cargo handling work cannot be obtained, the hybrid control unit is actually used for the energy output for the cargo handling work and the cargo handling work. A difference occurs with energy, and it is desirable to compensate for this difference in view of problems such as fuel consumption of the internal combustion engine.

  According to this invention, when the communication between the hybrid control unit and the cargo handling control unit is impossible, the hybrid control unit preliminarily supplies energy necessary for the cargo handling work so that the cargo handling work can be performed at a minimum. The drive of the internal combustion engine is controlled so that it can be set and output as a constant value. Further, if the amount of power stored in the battery is excessive, the driving of the internal combustion engine is stopped. The hybrid control unit controls the battery so as to supply electric power to the motor generator in order to output the energy necessary for the cargo handling work to the motor generator so that the cargo handling work can be performed at a minimum. On the other hand, if the storage amount of the battery is insufficient, the internal combustion engine is controlled so that the drive of the internal combustion engine can be restarted from the stopped state and output as the constant value. Therefore, even if the hybrid control unit cannot obtain information on the energy required for the cargo handling operation, the energy output by the internal combustion engine for the cargo handling operation and the energy actually used in the cargo handling operation Generation of a difference can be suppressed.

  According to the present invention, control in a hybrid forklift can be simplified.

The schematic side view of the hybrid type forklift in this embodiment. The schematic block diagram of a hybrid type forklift. The block diagram for demonstrating the control system of a hybrid type forklift. The graph which shows the relationship between the engine speed and engine torque with which fuel consumption becomes the minimum.

  Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. In the following description, “front”, “back”, “left”, “right”, “up”, and “down” are based on the state in which the forklift driver faces the front (forward direction) of the vehicle. “Front”, “Back”, “Left”, “Right”, “Up”, “Down” are shown.

  As shown in FIG. 1, a hybrid forklift 10 (hereinafter simply referred to as “forklift 10”) is provided with a cargo handling device 12 at the front portion of a vehicle body 11. A driving wheel (front wheel) 13 is provided at the front lower part of the vehicle body 11, and a steering wheel (rear wheel) 14 is provided at the rear lower part of the vehicle body 11. A cab 15 is provided in the center of the vehicle body 11. The driver's cab 15 is provided with a driving seat 16 on which a driver can sit. Below the operation seat 16, an engine 17 as an internal combustion engine, a travel motor 19, and an oil pump 20 are fixed to the rear portion of the vehicle body frame F and are installed in a state covered with a hood 21. The oil pump 20 pumps up the hydraulic oil stored in the oil tank 22 (see FIG. 2), and the pumped up hydraulic oil is supplied to the tilt cylinder 24 and the lift cylinder 25 via the cargo handling valve 23 (see FIG. 2). It has become so. The cargo handling valve 23 is connected to the tilt cylinder 24, the lift cylinder 25, the oil tank 22, and the oil pump 20 through a pipe line that forms a flow path for hydraulic oil.

  The cargo handling device 12 will be described. A mast 26 is erected on the front portion of the vehicle body 11. The mast 26 is a multistage type including a pair of left and right outer masts 27 and an inner mast 28. A hydraulic tilt cylinder 24 is connected to the outer mast 27 and can be tilted back and forth with respect to the vehicle body 11 by operation of the tilt cylinder 24. A hydraulic lift cylinder 25 is connected to the inner mast 28, and the inside of the outer mast 27 can be slid up and down by the operation of the lift cylinder 25. The mast 26 is provided with a pair of left and right forks 29 via a lift bracket 30. The lift bracket 30 is provided on the inner mast 28 so as to be movable up and down.

  A handle column 31 is provided in front of the operation seat 16 in the cab 15. A steering handle 32 for changing the steering angle of the steering wheel 14 is mounted on the handle column 31. A forward / reverse lever (direction lever) 33 is provided on the left side of the handle column 31 to instruct the traveling direction (traveling direction) of the vehicle. On the other hand, on the right side of the handle column 31, a lift lever 34 (see FIG. 3) operated when the cargo handling device 12 (fork 29) is moved up and down and an operation performed when the cargo handling device 12 (mast 26) is tilted. A tilt lever 35 (see FIG. 3) is provided. Further, an accelerator pedal A is provided below (floor) the operation seat 16.

Next, a schematic configuration of the forklift 10 according to the present embodiment will be described with reference to FIG.
As shown in FIG. 2, the forklift 10 includes a traveling motor 19, and the traveling wheels 19 are connected to the traveling motor 19 via a torque converter 41 and a transmission 42. The output shaft 17a of the engine 17 included in the forklift 10 is connected to one end of a rotating shaft of a cargo handling motor 43 as a motor generator for driving the oil pump 20 via the clutch 18, and the cargo handling motor. An oil pump 20 is connected to the other end of the rotating shaft at 43. The clutch 18 connects / disconnects the engine 17 and the cargo handling motor 43. In addition, an inverter 19a is connected to the cargo handling motor 43, and a battery 55 is connected via the inverter 19a. A traveling motor 19 is connected to the inverter 19a. The battery 55 stores the electric power generated when the cargo handling motor 43 is in the power generation state. Further, when the cargo handling motor 43 is in an electric state, electric power is supplied from the battery 55 to the cargo handling motor 43. For example, when sufficient power is stored in the battery 55 or when the load of the cargo handling work is small, the clutch 18 disconnects the output shaft 17a of the engine 17 from the cargo handling motor 43 to cut off the transmission of power. To do. Then, the engine 17 is stopped and power is supplied from the battery 55 to the cargo handling motor 43 to drive the cargo handling motor 43, so that the cargo handling operation can be performed only by the power of the cargo handling motor 43.

  FIG. 3 shows a block diagram of the control system of the forklift 10. As shown in FIG. 3, the cargo handling motor 43 is connected to a cargo handling motor control unit 51 (hereinafter simply referred to as “LM ECU 51”) that controls the driving of the cargo handling motor 43. The LMECU 51 controls the rotation speed of the cargo handling motor 43. The LMECU 51 is connected to a cargo handling control unit 52 (hereinafter simply referred to as “LECU 52”). The LMECU 51 and the LECU 52 can communicate with each other. The LECU 52 receives the output from the lift lever 34 or the tilt lever 35 to the LECU 52, thereby opening / closing command calculation function of the cargo handling valve 23 for calculating the opening / closing command value of the cargo handling valve 23, and a command for the rotational speed of the cargo handling motor 43. It has a rotation speed command calculation function of the cargo handling motor 43 that calculates the value. Further, the LECU 52 performs other cargo handling control. The LECU 52 can execute a rotational speed command calculation and transmit a rotational speed command of the cargo handling motor 43 to the LMECU 51.

  Further, the forklift 10 is provided with a hybrid control unit 53 (hereinafter simply referred to as “HVECU 53”) that integrally controls the forklift 10 such as the engine 17, the traveling motor 19, the cargo handling motor 43, and the battery 55. The HVECU 53 can communicate with the LECU 52, and input information input from the lift lever 34 or the tilt lever 35 to the LECU 52 is bypassed from the LECU 52 to the HVECU 53. The HVECU 53 includes an engine control unit (hereinafter simply referred to as “ECU 54”) that controls the driving of the engine 17. The ECU 54 performs various controls of the engine 17 such as the rotational speed of the engine 17. The HVECU 53 has an engine output command calculation function.

  The HVECU 53 has a rotation speed command calculation function of the cargo handling motor 43 included in the LECU 52 and an opening / closing command calculation function of the cargo handling valve 23. Then, the HVECU 53 calculates an opening / closing command for the cargo handling valve 23 based on the input information bypassed from the LECU 52, calculates a rotation speed command for the cargo handling motor 43, and sends an opening / closing command for the cargo handling valve 23 to the LECU 52 and the cargo handling motor 43. The rotation speed command can be transmitted. The opening / closing command for the cargo handling valve 23 and the rotational speed command for the cargo handling motor 43 are commands necessary for the cargo handling operation of the forklift 10.

  In a state where the HVECU 53 and the LECU 52 can communicate with each other in the control system, input information input from the lift lever 34 or the tilt lever 35 to the LECU 52 is input by bypassing from the LECU 52 to the HVECU 53. Opening / closing command calculation and rotation speed command calculation of the cargo handling motor 43 are executed. Then, the rotation speed command of the cargo handling motor 43 is transmitted to the LECU 52 and further transmitted from the LECU 52 to the LMECU 51. The LMECU 51 that has received the rotational speed command controls the rotational speed of the cargo handling motor 43 based on the rotational speed command. The opening / closing command for the cargo handling valve 23 is transmitted to the LECU 52, and the LECU 52 that receives the opening / closing command controls the opening / closing of the cargo handling valve 23 based on the opening / closing command. When the HVECU 53 and the LECU 52 can communicate with each other, the rotation speed command calculation function of the cargo handling motor 43 and the opening / closing command calculation function of the cargo handling valve 23 in the LECU 52 are stopped.

  On the other hand, the control system of the forklift 10 has a fail-safe function for avoiding that the cargo handling control is stopped when the communication between the HVECU 53 and the LECU 52 is not possible. When communication between the HVECU 53 and the LECU 52 is impossible, that is, when the input information input from the lift lever 34 or the tilt lever 35 to the LECU 52 is no longer bypassed from the LECU 52 to the HVECU 53, the control system performs a fail-safe function. . At the time of executing the fail safe function, in the control system, the opening / closing command calculation of the cargo handling valve 23 and the rotation speed command calculation of the cargo handling motor 43 are executed by the LECU 52. Then, the rotational speed command of the cargo handling motor 43 obtained by the calculation of the LECU 52 is transmitted to the LMECU 51, and the LMECU 51 that has received the rotational speed command controls the rotational speed of the cargo handling motor 43 based on the rotational speed command. It has become. Further, when the opening / closing command for the cargo handling valve 23 is obtained by the calculation of the LECU 52, the LECU 52 controls the opening / closing of the cargo handling valve 23 based on the opening / closing command.

  Here, FIG. 4 shows a minimum fuel consumption curve representing the relationship between the engine speed and the engine torque at which the fuel consumption is minimized. That is, the curve L shown in FIG. 4 represents an operating condition in which the engine 17 can be operated in an optimal operation state in which the fuel consumption is minimized.

  In a state where communication between the HVECU 53 and the LECU 52 is possible, the HVECU 53 operates the engine 17 at an operating point (Ne, Te) on the minimum fuel consumption curve to perform traveling and cargo handling work on the forklift 10. That is, the HVECU 53 executes an engine output command calculation so as to drive the engine 17 along the minimum fuel consumption curve, and the ECU 54 controls the engine 17 based on the obtained engine output command. And when the motive power of the engine 17 output to the output shaft 17a is surplus, the HVECU 53 generates electric power by the cargo handling motor 43 that is operated by the surplus power of the engine 17 and is generated from the cargo handling motor 43. Control is performed so that electric power is stored in the battery 55.

  Further, the forklift 10 travels by driving the drive wheels 13 with the rotational power of the travel motor 19. Therefore, for example, when the travel energy in the forklift 10 is insufficient, the HVECU 53 performs control so that more power is supplied from the battery 55 to the travel motor 19 via the inverter 19a than usual. As a result, the travel motor 19 can supplement the power necessary for driving the drive wheels 13 with the power stored in the battery 55.

  When the power of the engine 17 is insufficient during the cargo handling work by the forklift 10, the HVECU 53 controls the power handling motor 43 to operate by supplying electric power from the battery 55 to the cargo handling motor 43. Therefore, the cargo handling motor 43 can assist the drive of the oil pump 20 to assist the cargo handling operation. On the other hand, when the motive power of the engine 17 is surplus, the HVECU 53 generates electric power by the cargo handling motor 43 that is operated by the surplus power of the engine 17 and stores the electric power generated from the cargo handling motor 43 in the battery 55. To control.

  When the communication between the HVECU 53 and the LECU 52 becomes impossible, the control system executes the fail-safe function, and the HVECU 53 transmits a command for controlling the engine 17 to the ECU 54. At this time, the HVECU 53 cannot execute the engine output command calculation so that the engine 17 is operated along the minimum fuel consumption curve in consideration of the energy required for the cargo handling work in the forklift 10. Therefore, the HVECU 53 does not obtain information on the energy required for the cargo handling operation, and causes the ECU 54 to control the engine 17. A difference occurs with the energy used.

  Therefore, in the present embodiment, the HVECU 53 sets energy necessary for the cargo handling work in advance so that the cargo handling work can be performed at a minimum, and the energy necessary for the cargo handling work is set at a constant value from the engine 17. Execute engine output command calculation so that output is possible. The ECU 54 that has received the engine output command controls the driving of the engine 17.

  Further, the HVECU 53 monitors the storage amount of the power stored in the battery 55, and if the storage amount of the battery 55 is excessive, the HVECU 53 disconnects the output shaft 17a of the engine 17 from the cargo handling motor 43. The power transmission is interrupted and the drive of the engine 17 is stopped. Then, the HVECU 53 supplies the battery 55 to the cargo handling motor 43 via the LMECU 51 in order to output the energy necessary for the cargo handling work to the cargo handling motor 43 so that the cargo handling work can be performed at a minimum. Control. On the other hand, if the charged amount of the battery 55 is insufficient, the drive of the engine 17 is restarted from the stopped state, and the engine 17 is controlled so that it can be output as the constant value. By doing so, even if the HVECU 53 cannot obtain information on energy necessary for the cargo handling work, the energy output by the engine 17 for the cargo handling work and the energy actually used in the cargo handling work It is possible to suppress the occurrence of the difference.

In the above embodiment, the following effects can be obtained.
(1) The forklift 10 includes an HVECU 53 that is an upper control unit, and the HVECU 53 can execute an opening / closing command calculation of the cargo handling valve 23 and a rotation speed command calculation of the cargo handling motor 43. Further, the forklift 10 includes a LECU 52 that is a lower control unit of the HVECU 53. When the HVECU 53 and the LECU 52 can communicate with each other, input information input from the lift lever 34 or the tilt lever 35 to the LECU 52 is bypassed from the LECU 52 to the HVECU 53. The And while HVECU53 performs each command calculation, LECU52 does not perform each command calculation. On the other hand, when communication between HVECU 53 and LECU 52 becomes impossible, the control system executes a fail-safe function, and LECU 52 executes each command calculation, while HVECU 53 does not perform each command calculation. Therefore, in order to enable the fail-safe function to be executed, as in Patent Document 1, the control by the control system is compared with the case where the HVECU 53 and the LECU 52 execute internal calculations in synchronization and collate the calculation results. Can be simplified. As a result, the control can be simplified as compared with the case where the control system having the fail-safe function of Patent Document 1 is used for the forklift 10 that performs traveling and cargo handling work.

  (2) When the communication between the HVECU 53 and the LECU 52 is in a communicable state, it is possible to eliminate redundant control by stopping the calculation function of the LECU 52 among the calculation functions of the HVECU 53 and the LECU 52. Therefore, the control in the forklift 10 can be further simplified.

  (3) When the communication between the HVECU 53 and the LECU 52 is impossible, the HVECU 53 executes an engine output command calculation so that the energy required for the cargo handling work can be output from the engine 17 at a constant value. If the amount of power stored in the battery 55 is excessive, the clutch 18 disconnects the output shaft 17a of the engine 17 and the cargo handling motor 43 to cut off power transmission and stop the driving of the engine 17. Then, the HVECU 53 controls the battery 55 so as to supply electric power to the cargo handling motor 43 in order to output the energy necessary for the cargo handling work to the cargo handling motor 43 so that the cargo handling work can be performed at a minimum. . On the other hand, if the charged amount of the battery 55 is insufficient, the drive of the engine 17 is restarted from the stopped state, and the engine 17 is controlled so that it can be output as the constant value. Therefore, even if the HVECU 53 cannot communicate with the LECU 52 and cannot obtain energy information necessary for the cargo handling work, the energy output by the engine 17 for the cargo handling work and the actual use in the cargo handling work are used. It is possible to suppress a difference from the generated energy.

In addition, you may change the said embodiment as follows.
In the embodiment, when communication between the HVECU 53 and the LECU 52 becomes impossible, both the opening / closing command calculation of the cargo handling valve 23 and the rotation speed command calculation of the cargo handling motor 43 are calculated by the arithmetic processing function of the LECU 52. However, it is not limited to this. For example, a cargo handling motor rotation speed command for commanding the rotation speed of the cargo handling motor 43 that can secure a minimum amount of hydraulic fluid necessary for the cargo handling work is set in advance. When communication is disabled, the LECU 52 outputs a preset handling motor rotation speed command to the LMECU 51, and the cargo handling valve 23 obtained by the calculation of the LECU 52 in a state where the minimum required hydraulic oil flow rate is secured by the cargo handling motor 43. The opening / closing command may be appropriately changed to control the opening / closing of the cargo handling valve 23 to control the cargo handling speed.

  In the embodiment, when communication between the HVECU 53 and the LECU 52 becomes impossible, both the opening / closing command calculation of the cargo handling valve 23 and the rotation speed command calculation of the cargo handling motor 43 are calculated by the arithmetic processing function of the LECU 52. However, it is not limited to this. For example, the opening / closing command and control of the cargo handling valve 23 obtained by the calculation of the LECU 52 is performed so that the cargo handling valve 23 is opened and closed only to the minimum necessary, and the rotation speed command of the cargo handling motor 43 obtained by the calculation of the LECU 52 is appropriately set. It may be changed to control the cargo handling speed.

  In the embodiment, the calculation function of the LECU 52 is stopped when the HVECU 53 and the LECU 52 are communicable. However, even if the communication between the HVECU 53 and the LECU 52 is communicable, It is not necessary to stop the calculation function.

  In the embodiment, when communication between the HVECU 53 and the LECU 52 is impossible, the HVECU 53 executes the engine output command calculation so that the energy required for the cargo handling work can be output from the engine 17 at a constant value. However, it is not limited to this. When the communication between the HVECU 53 and the LECU 52 is impossible, the HVECU 53 performs control so as to output an engine torque on the minimum fuel consumption curve that maximizes the thermal efficiency at the engine speed at a predetermined interval (predetermined time). Then, the electric power generated by the cargo handling motor 43 being operated by the surplus power of the engine 17 may be stored in the battery 55.

  In the embodiment, when communication between the HVECU 53 and the LECU 52 is impossible, the HVECU 53 executes the engine output command calculation so that the energy required for the cargo handling work can be output from the engine 17 at a constant value. However, it is not limited to this. When the communication between the HVECU 53 and the LECU 52 is impossible, the HVECU 53 performs control so as to output an engine torque on the minimum fuel consumption curve that maximizes the thermal efficiency at the engine speed at a predetermined interval (predetermined time). Then, the cargo handling motor 43 may be operated by the electric power stored in the battery 55 to assist the shortage of power of the engine 17.

  In the embodiment, the inverter 19a connected to both the cargo handling motor 43 and the traveling motor 19 is provided. However, the LMECU 51 has a function as an inverter that performs power conversion between the cargo handling motor 43 and the battery 55. The inverter 19a may perform only power conversion between the traveling motor 19 and the battery 55.

  DESCRIPTION OF SYMBOLS 10 ... Hybrid type forklift, 17 ... Engine as internal combustion engine, 43 ... Cargo handling motor as motor generator, 51 ... Cargo handling motor control unit (LMCU), 52 ... Cargo handling control unit (LECU), 53 ... Hybrid control unit (HVECU) ), 55 ... battery.

Claims (3)

A battery capable of running and handling work using power of at least one of an internal combustion engine and a motor generator, storing electric power generated by the motor generator, and supplying the electric power to the motor generator; A hybrid forklift control system,
A cargo handling motor control unit that controls the driving of the motor generator used for performing the cargo handling work, a cargo handling control unit that calculates a command necessary for the cargo handling work, and the hybrid forklift are integratedly controlled and the cargo handling control. A hybrid control unit having an arithmetic function of the unit,
In a state where communication between the hybrid control unit and the cargo handling control unit is possible, input information necessary for the cargo handling operation input to the cargo handling control unit is input from the cargo handling control unit to the hybrid control unit. Thus, while the hybrid control unit calculates a command required for cargo handling work,
Control of a hybrid forklift characterized in that, in a state where communication between the hybrid control unit and the cargo handling control unit is impossible, the cargo handling control unit executes a fail-safe function for calculating a command necessary for cargo handling work. system.   2. The hybrid forklift control system according to claim 1, wherein in a state in which communication between the hybrid control unit and the cargo handling control unit is possible, the calculation function of the cargo handling control unit is stopped.   In a state in which communication between the hybrid control unit and the cargo handling control unit is not possible, the hybrid control unit controls the internal combustion engine to stop or keep the drive constant, and performs a cargo handling operation in the hybrid forklift. 3. The hybrid forklift control system according to claim 1, wherein a surplus or deficiency of necessary energy is stored in the battery or output from the battery. 4.

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