JP2008265462A - Industrial vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably supply power from a power generator even when abnormality is caused in an electric storage means by stably and efficiently supply power to a system when the electric storage means is normally operated in an industrial vehicle. <P>SOLUTION: When a battery 106 (an electric storage means) is normally operated, the power is supplied to a running motor 105 for vehicle running at least from either an inverter power generator (102 and 103) or the battery 106. When abnormality occurs in the battery 106, the battery 106 is disconnected from the system. In the power generator inverter 103, the inverter control is stopped, and the generated power of the power generator 102 is converted from an alternating current to a direct current, and supplied to the running motor 105. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an industrial vehicle having an inverter controlled generator.

  2. Description of the Related Art Some industrial vehicles such as industrial vehicles for cargo handling work have an engine, a generator driven by the engine, and power storage means such as a battery. In such industrial vehicles, the traveling motor is driven by at least one of the electric power generated by the generator and the electric power supplied by the power storage means. In addition, since the power storage means serves as a voltage source, a system voltage that ensures stable operation of the system that constitutes the industrial vehicle may be secured.

  An inverter-controlled generator may be used as a generator for the industrial vehicle. Inverter-controlled generators have higher power generation efficiency compared to the case of using non-inverter-controlled DC generators and three-phase AC generators. It is also possible to function. For example, a generator can be used as a starter when starting the engine, or a cargo handling work device or the like can be driven by the generator. It is also possible to stably supply power to a system set at a predetermined system voltage regardless of the number of revolutions of the generator.

  By the way, in such an industrial vehicle, if the power storage means breaks down, problems such as the system voltage not being secured and the system not stably operating or the output of the travel motor being insufficient may occur.

  The hybrid vehicle of Patent Document 1 has an engine, a generator, a battery, and a motor. In Patent Document 1, when the engine drives the generator, the electric power generated by the generator is supplied to the motor via the rectifier and the inverter. The electric power from the battery is supplied to the motor via the inverter. In Patent Document 1, a switch is provided between a battery and an inverter. The controller controls the switch in accordance with a predetermined condition, thereby preventing a motor output shortage due to a battery voltage shortage.

  The hybrid vehicle of Patent Document 2 has a step-up / down converter. The output of the main battery is boosted by the step-up / down converter and supplied to the electric motor unit. Patent Document 2 has a DC-DC converter that is fed from a main battery. In Patent Document 2, when the DC-DC converter is not fed from the main battery, the output voltage of the electric motor unit is reduced within a predetermined range, and the DC-DC converter is connected in series with the electric motor unit. Thus, even when power is not supplied from the main battery, electric power is supplied from the electric motor unit to the DC-DC converter.

JP-A-7-87614 (FIG. 1) Japanese Patent Laying-Open No. 2003-134606 (FIG. 1)

  In Patent Document 1, the generator is not controlled by an inverter. Therefore, power is not stably supplied to the system, and power generation efficiency is low. Moreover, in patent document 2, when there is no voltage supply from a main battery, it only depends on the output from a generator. However, even in such a case, if inverter control is performed in the motor unit, for example, a high voltage may be fed back to the generator via the inverter, and power may not be stably supplied from the generator. In such a case, the hybrid vehicle of Patent Literature 2 may not travel stably and may stop completely.

  The object of the present invention is to supply power stably and efficiently to the system when the power storage means is operating normally, and to stabilize power from the generator even when the power storage means is not operating normally. It is to provide industrial vehicles to be supplied.

Means and effects for solving the problems

  In the first aspect, the industrial vehicle of the present invention includes an engine, power storage means, a normal mode that is driven by the engine to generate electric power and outputs the generated power while controlling the inverter, and the generated power is not controlled by the inverter. An inverter generator that selectively takes a rectification mode for converting from alternating current to direct current and outputting, a traveling motor for vehicle traveling driven by electric power supplied from at least one of the generator and power storage means, and Determining means for determining whether or not the power storage means is operating normally; and when the determination means determines that the power storage means is not operating normally, power is supplied from the power storage means to the travel motor. The normal mode is maintained in the inverter generator when the determining means determines that the stopping means to stop and the power storage means are operating normally. So, the accumulator unit is the determination unit and is not working properly when it is determined, and a control means to assume said rectification mode to the inverter generator.

  In a second aspect, the industrial vehicle of the present invention is an engine, power storage means, a normal mode that is driven by the engine to generate electric power and outputs the generated electric power while controlling the inverter, and the generated electric power is controlled by the inverter. An inverter generator that selectively takes a rectifying mode that is converted from alternating current to direct current and output, a traveling motor for vehicle traveling that is driven by electric power supplied from at least one of the generator and the storage means, Determining means for determining whether or not the power storage means is operating normally; and when the determination means determines that the power storage means is not operating normally, power from the power storage means to the travel motor Stop means for stopping supply, and the storage means is not operating normally when the determination means determines that the storage means is not operating normally The inverter generator is maintained in the normal mode when the determination unit determines that the notification unit is configured to notify the operator, the operation unit that receives an operation from the operator, and the storage unit is operating normally. When the notification means notifies the operator that the power storage means is not operating normally, and the operation means receives an operation from the operator thereafter, the inverter generator is caused to take the rectification mode. Control means.

  According to the industrial vehicle of the present invention, the power supply is stopped when the power storage means is not operating normally, and the inverter control is stopped in the inverter generator so that the inverter functions as a rectifier. As a result, there is no possibility that a high voltage is fed back to the power generation circuit in the inverter generator, and even when the power storage means is not operating normally, power is stably supplied from the inverter generator to the traveling motor. Therefore, the traveling of the industrial vehicle is prevented from becoming unstable, and the situation where the industrial vehicle stops is avoided. In the first aspect, a configuration is realized in which the inverter generator is automatically shifted to the rectification mode when the power storage means is not normal. In the second aspect, the operator can accurately grasp that the power storage means is not normal, and a configuration is realized in which the inverter generator is manually shifted to the rectification mode. In addition, when the generator is inverter-controlled as in the present invention, power is stably supplied to the system, and the power generation efficiency is increased.

  In the present invention, the voltage supplied to the travel motor by the power storage means during normal operation is adjusted to a predetermined system voltage, and the control means operates normally with the power storage means. If the determination means determines that the motor has not been operated, the rotation of the engine when the travel motor is driven so that the voltage supplied from the inverter generator is maintained in the vicinity of the predetermined system voltage. It is preferable to control the number. When voltage supply by the power storage means is stopped and inverter control is stopped in the inverter generator, the system voltage in the industrial vehicle changes according to the engine speed. According to the above configuration, when the traveling motor is driven, the engine speed is maintained so that a predetermined system voltage when the power storage unit is operating normally is supplied from the inverter generator. Industrial vehicles run stably.

  Further, the present invention further includes a traveling inverter that performs inverter control of electric power supplied from the inverter generator to the traveling motor, and the control unit is configured so that the power storage unit is not operating normally. When the determination means determines, the rotation speed of the travel motor is set so that the rotation speed of the travel motor is equal to or less than the rotation speed corresponding to the upper limit of the output of the engine whose rotation speed is controlled by the control means. It is preferable to limit. According to this configuration, for example, when a traveling inverter that increases the rotational speed of the traveling motor by an accelerator pedal or the like is provided, the rotational speed is limited so as not to exceed the output of the engine. The power supply becomes stable.

  Further, in the present invention, the travel inverter selectively takes a regeneration mode in which power can be regenerated from the travel motor and a non-regeneration mode in which power is not regenerated from the travel motor, and the control means includes the control unit, When the determination means determines that the power storage means is operating normally, the traveling inverter holds the regeneration mode, and when the determination means determines that the power storage means is not operating normally, It is preferable to make the traveling inverter take the non-regenerative mode. According to this configuration, the regeneration of electric power is prevented, so that the situation where electric power is not stably supplied from the inverter generator due to the regeneration of electric power to the inverter generator is prevented.

  Further, the present invention further includes a cargo handling work device, wherein the inverter generator is driven by a generator mode driven by the engine to generate power in the normal mode, and by electric power supplied from the power storage means. And the load handling work device is driven by at least one of the engine and the inverter generator in the electric motor mode, and the control means includes the power storage device. When the determination means determines that the means is not operating normally, the cargo handling work device is driven only by the engine and is supplied from the inverter generator only when the travel motor is driven. Controlling the engine speed so that a voltage is maintained in the vicinity of the predetermined system voltage; Masui. According to this configuration, since the output of the engine is not limited when the traveling motor is not driven, sufficient output is supplied to the cargo handling work device even when the power storage means is not operating normally.

  The present invention further includes a cargo handling work device driven by electric power supplied from at least one of the inverter generator and the power storage means, and the stop means is configured such that the power storage means operates normally. If the determination means determines that there is not, both the power supply from the power storage means to the cargo handling work device and the travel motor are stopped, and the control means determines that the power storage means is not operating normally. When the means determines, the voltage supplied from the inverter generator is close to the predetermined system voltage both when the travel motor is driven and when the cargo handling work device is driven. You may control the rotation speed of the said engine so that it may be hold | maintained. According to this configuration, even when the cargo handling work device is driven by the power supplied from the inverter generator when the power storage means is not operating normally, a predetermined system voltage is supplied to the system including the cargo handling work device. As a result, the cargo handling work device and the traveling motor operate stably.

  The present invention further includes a power supply source that is different from the power storage means, and a starter for the engine that is driven by the power supplied from the power supply source. If the inverter generator is functioning as a starter after receiving power supply from the power storage means, the auxiliary starter will start the engine even if the power storage means does not operate normally and the normal means cannot start the engine. Can be started.

  Hereinafter, a forklift as an example of an industrial vehicle according to a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a forklift 100 according to the first embodiment.

[First Embodiment]
The forklift 100 includes an engine 101, a generator motor 102, a battery 106 (power storage means), a generator inverter 103, a travel inverter 104, a travel motor 105, and a travel unit 111. Moreover, it has the controller 120 which controls operation | movement of each part of the forklift 100. The rotation speed of the engine 101 is controlled by the controller 120. The crankshaft of the engine 101 is coaxially connected to the drive shaft of the generator motor 102 via a clutch (all of the crankshaft, the drive shaft, and the clutch are not shown). Such a clutch can take a state where the driving force from the engine 101 can be transmitted to the generator motor 102 and a state where the driving force from the engine 101 cannot be transmitted to the generator motor 102. The state of the clutch is switched by the controller 120.

  The generator motor 102 is electrically connected to the generator inverter 103. The generator inverter 103 is electrically connected to the traveling inverter 104 and is also electrically connected to the battery 106 via a relay 112 and a fuse 113. Note that the relay 112 is on during normal times. The generator motor 102 has a generator mode and a motor mode. The generator motor 102 is driven by the engine 101 to generate electric power in the generator mode, and operates as an electric motor by the electric power supplied from the battery 106 in the electric motor mode. In the electric motor mode, it also functions as a starter for starting the operation of the engine 101. The controller 120 switches between the generator mode and the motor mode in the generator motor 102 by appropriately controlling the rotational speed of the engine 101, switching of a switching element (described later) of the generator inverter 103, and the state of the clutch. .

  The generator inverter 103 has a plurality of switching elements such as MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and the like, and a plurality of diodes connected in parallel to each of these switching elements. The generator motor 102 is inverter-controlled while being controlled to be switched in the switching element by the controller 120 (normal mode). The generator motor 102 cooperates with the generator inverter 103 to function as an inverter generator that is inverter-controlled in the generator mode, and also functions as an inverter motor in the motor mode. The generator inverter 103 supplies the electric power from the battery 106 to the generator motor 102 in the electric motor mode, and supplies the electric power generated in the electric generator motor 102 in the electric generator mode to the traveling inverter 104 and the battery 106.

  As with the generator inverter 103, the traveling inverter 104 has a plurality of switching elements and a plurality of diodes connected in parallel thereto. The electric power supplied from the generator motor 102 and the electric power supplied from the battery 106 via the generator inverter 103 and the electric power supplied from the battery 106 are subjected to inverter control, and these electric power is supplied to the traveling motor 105. The operation of the traveling inverter 104 is controlled by the controller 120. For example, the controller 120 controls the switching timing in the switching element of the traveling inverter 104. Thereby, the frequency of the alternating current supplied to the traveling motor 105 and the magnitude of the electric power are controlled.

  In addition, the traveling inverter 104 has a regenerative mode in which regenerative power is regenerated to the battery 106 when regenerative power is supplied from the travel motor 105 as will be described later, and the battery 106 even if regenerative power is supplied from the travel motor 105. You can take a non-regenerative mode that doesn't regenerate. Switching between the regenerative mode and the non-regenerative mode is controlled by the controller 120.

  Similar to the generator motor 102, the travel motor 105 has a generator mode and a motor mode. In the electric motor mode, the traveling motor 105 is driven by the electric power supplied from the traveling inverter 104. On the other hand, the traveling unit 111 has driving wheels disposed at both ends of the shaft. The traveling unit 111 is configured such that a driving force is transmitted from the driving shaft of the traveling motor 105 to the shaft. When the travel motor 105 is driven, the drive wheels rotate and the forklift 100 travels. The traveling unit 111 also has a braking mechanism (not shown), and the braking mechanism brakes the rotation of the shaft of the traveling unit 111 when an operation unit 115 described later receives an operation from the operator.

  The traveling motor 105 is switched to the generator mode when the traveling unit 111 is braked. In the generator mode, the traveling motor 105 is driven from the traveling unit 111 to generate electric power and supplies generated electric power to the traveling inverter 104. As described above, traveling inverter 104 regenerates regenerative power from traveling motor 105 to battery 106 when in the regeneration mode. Accordingly, the battery 106 stores electricity. In addition, the braking force is transmitted to the traveling unit 111 via the traveling motor 105 by regenerating electric power to the battery 106 in this way. When the traveling inverter 104 is in the non-regenerative mode, the regenerative power is not supplied to the battery 106, and the traveling motor 105 rotates idly.

  In the above configuration, the voltage supplied to the generator inverter 103 and the traveling inverter 104 is held at a predetermined system voltage by the high voltage supplied from the battery 106. The system voltage is adjusted to such a level that the generator motor 102 and the traveling motor 105 are stably supplied with power for traveling from the generator inverter 103 and the traveling inverter 104 under the voltage supplied from the battery 106. ing.

  The forklift 100 includes a cargo handling drive 109 and a fork 110 (a cargo handling work device). A drive mechanism (not shown) of the cargo handling machine 109 moves the loading platform of the fork 110 in the vertical direction. By driving the load handling machine 109 and running the forklift 100, the forklift 100 can perform various cargo handling operations. The loading operation includes, for example, placing an object on the loading platform of the fork 110, moving the object on the loading platform in the vertical direction, and changing the object on the loading platform to another loading platform.

  The drive shaft of the generator motor 102 is coupled to the drive mechanism of the cargo handling drive 109 so that the drive force can be transmitted to the cargo handling drive 109. For example, the cargo handling drive 109 may be provided with a hydraulic pump for cargo handling work, and the hydraulic pump may be driven by the driving force transmitted from the drive shaft of the generator motor 102. As described above, the crankshaft of the engine 101 and the drive shaft of the generator motor 102 are coaxially connected via the clutch. Therefore, when the generator motor 102 is in the generator mode, the engine 101 serves as a drive source for both the generator motor 102 and the cargo handling drive 109 arranged on the same axis. On the other hand, when the generator motor 102 is in the motor mode, both the engine 101 and the generator motor 102 or only the generator motor 102 is the drive source of the cargo handling drive 109. The state in which the engine 101 is a driving source for the cargo handling drive 109 and the state in which the engine 101 is not a driving source are switched by a clutch.

  The forklift 100 has an auxiliary starter 108. A power supply source such as a battery is provided in the auxiliary starter 108. Such a power supply source is separate from the battery 106, but may be one that stores power by receiving power supply from the battery 106 or the generator motor 102 at normal times. The auxiliary starter 108 operates based on a control signal from the controller 120 and starts the operation of the engine 101.

  The forklift 100 has an auxiliary machine 107. The auxiliary machine 107 includes devices that are not directly used for traveling and cargo handling, such as an air conditioner and a battery that supplies electric power to other auxiliary machines such as an air conditioner.

  The forklift 100 has an alarm 114 and an operation unit 115. Although the alarm 114 is not normally activated, an alarm sound is generated when a control signal from the controller 120 is received. Alternatively, a warning lamp may be turned on or a warning mark may be displayed on the display panel.

  The operation unit 115 includes various levers and switches such as an accelerator lever, a shift lever, a cargo handling work lever, and an ignition switch. An operator of the forklift 100 can operate various levers and switches of the operation unit 115. When the operator operates these levers and switches, a signal indicating that the switch has been operated and a signal indicating the state of the lever are transmitted to the controller 120. The controller 120 controls the engine 101, the cargo handling drive 109, the generator inverter 103, and the like based on signals from the operation unit 115. For example, when a signal indicating the state of the accelerator lever is received, a control signal instructing to change the rotational speed to a predetermined magnitude is transmitted to the engine 101 based on the state indicated by the signal. When the engine 101 receives the control signal, the engine 101 operates at the rotation speed indicated by the control signal.

  The forklift 100 is provided with various sensors that detect whether or not the battery 106 is operating normally. Examples of such a sensor include a sensor that detects that the fuse 113 has been blown, a sensor that detects whether or not the temperature of the battery 106 is excessive, a voltage supplied from the battery 106 falls below a predetermined range, or , A sensor for detecting exceeding, and the like are included. A detection signal from such a sensor is transmitted to the controller 120. The controller 120 determines whether or not the battery 106 is operating normally based on the detection signal (determination means). For example, when the voltage supplied from the battery 106 and the predetermined system voltage are largely different, it is determined that the battery 106 is not operating normally. Note that the fuse 113 is configured to autonomously break when the voltage of the battery 106 becomes excessive. In this way, circuits and devices that operate by autonomously detecting an abnormality in the battery 106 are provided, and further, such a circuit or the like detects an abnormality in the battery 106, so that the battery 106 is properly operated. The controller 120 may perform control when it is not operating.

  If controller 120 determines that battery 106 is not operating normally, it turns off relay 112. This disconnects the battery 106 from the system. Then, the forklift 100 is switched from the normal travel mode to the low speed travel mode. The low-speed travel mode is a travel mode in which each part of the forklift 100 is controlled by the controller 120 as in the following (1) to (4).

  (1) In the generator inverter 103, inverter control by switching of the switching element is stopped. Thus, the generator inverter 103 functions as a rectifier that rectifies the alternating current from the generator motor 102 into a direct current by the diode and outputs the direct current to the traveling inverter 104 (rectification mode).

  (2) When the traveling motor 105 is driven, the rotational speed of the engine 101 is limited to a predetermined magnitude or less. Here, the predetermined magnitude corresponds to the voltage supplied to the traveling inverter 104 via the generator inverter 103 when the engine 101 drives the generator motor 102 in the vicinity of the system voltage in the normal traveling mode. To do. Thus, even when the traveling motor 105 is driven by the traveling inverter 104, the voltage supplied from the engine 101 and the generator inverter 103 is limited to be close to the precision system voltage.

  (3) When the travel motor 105 is driven, the alternating current supplied to the travel motor 105 in the travel inverter 104 is adjusted so that the vehicle speed of the forklift 100 is limited to a predetermined magnitude or less. Here, the upper limit value of the vehicle speed is adjusted to a magnitude corresponding to that which does not exceed the maximum value of the output from the engine 101 whose rotational speed is limited in the above (1). As a result, the rotational speed of the traveling motor 105 is controlled to be equal to or lower than the rotational speed corresponding to the maximum value of the output from the engine 101, so that stable traveling is possible according to the output from the engine 101 whose rotational speed is limited. It becomes.

  (4) The traveling inverter 104 is set to the non-regenerative mode. As a result, the regenerative power from the traveling motor 105 is prevented from returning to the generator inverter 103 and the like.

  Hereinafter, with reference to FIG. 2, a series of steps in which the controller 120 shifts the travel mode from the normal travel mode to the low speed travel mode will be described.

  When the controller 120 determines that the battery 106 is operating normally (S101, Yes), the controller 120 maintains the normal travel mode (S100).

  When it is determined that the battery 106 is not operating normally (S101, No), the controller 120 sets the relay 112 to off (S102). As a result, the battery 106 that has stopped operating normally is disconnected from the system. Moreover, a control signal is transmitted to the alarm 114, and an alarm sound is generated in the alarm 114 (S102). As a result, the operator can know that the battery 106 does not operate normally. Next, the controller 120 determines whether or not the engine 101 has stopped (S103). If it determines with the engine 101 having stopped (S103, Yes), a control signal will be transmitted to the auxiliary starter 108, and the engine 101 will be started (S104). Thereafter, the process proceeds to step S105.

  If it is determined in S103 that the engine 101 is not stopped (S103, No), the controller 120 reduces the rotational speed of the engine 101 to an idling level (S105). As a result, when the battery 106 stops operating normally, the rotational speed of the engine 101 is quickly reduced, so that a stable operation of the forklift 100 is ensured promptly. Then, the inverter control of the generator motor 102 by the generator inverter 103 is stopped (S106; control (1) above), and the traveling inverter 104 is held in the non-regenerative mode (S106; control (4) above). ).

  Next, it is determined whether or not the traveling motor 105 is being driven, that is, whether or not the forklift 100 is traveling (S107). When it is determined that the travel motor 105 is being driven (S107, Yes), the controller 120 controls the engine 101 while limiting the rotational speed of the engine 101 and the rotational speed of the travel motor 105 (S108; the above (2) and ( 3) Control). In S108, the rotation speeds of the engine 101 and the traveling motor 105 are limited regardless of whether the cargo handling machine 109 is driven. On the other hand, if it is determined that the traveling motor 105 is not being driven (S107, No), the controller 120 does not limit the rotational speed of the engine 101 and controls the rotational speed necessary for the cargo handling drive 109 to perform the cargo handling operation. (S109). Then, the process returns to step S107.

  The following effects are produced by the above first embodiment.

  As soon as it is determined that the battery 106 does not operate normally, the battery 106 is disconnected from the system. This prevents a situation in which the forklift 100 does not operate normally due to the unstable system voltage supplied from the battery 106.

  Further, the inverter control is stopped in the low-speed traveling mode, and the generator inverter 103 operates as a rectifier. As a result, there is no possibility that a high voltage is fed back to the generator motor 102, and even when the battery 106 is not operating normally, power is stably supplied from the generator motor 102 to the traveling motor 105.

  Further, when the inverter control is stopped in the low speed traveling mode, a system voltage corresponding to the rotational speed of the engine 101 is supplied to a system including the generator inverter 103 and the traveling inverter 104. However, by limiting the rotational speed of the engine 101 as described above, the system voltage is adjusted so that the system operates stably. Moreover, since the rotation speed of the traveling motor 105 is also limited as described above, the forklift 100 can travel stably.

  Further, the traveling inverter 104 is maintained in the non-regenerative mode in the low-speed traveling mode, thereby preventing regenerative power from returning to the generator inverter 103. Therefore, the electric power from the generator motor 102 is stably supplied to the traveling inverter 104 via the generator inverter 103.

  Further, the rotational speed of the engine 101 is limited when the travel motor 105 is driven, but the rotational speed is not limited when the travel motor 105 is not driven. Therefore, when the forklift 100 is not traveling, the output of the engine 101 necessary for the cargo handling operation can be ensured. However, in the low-speed running mode, a system voltage corresponding to the rotation speed of the engine 101 is supplied to the system. Therefore, it is assumed that a configuration is realized in which at least the operation of the controller 120 is not hindered by the system voltage rising when the engine 101 is operated at the maximum number of revolutions necessary for the cargo handling operation.

  In addition, when the engine 101 stops in the low speed traveling mode, the auxiliary starter 108 starts the engine 101. Therefore, when the engine 101 is started with the electric power from the battery 106 at the normal time as in the present embodiment, it is possible to prevent the engine 101 from starting when the battery 106 does not operate normally.

  In addition, the generator motor 102 is inverter-controlled in the normal travel mode, so that power is stably supplied to the system and a configuration with high power generation efficiency is realized.

[Second Embodiment]
The second embodiment will be described below with reference to FIG. Note that the description of the same configuration as the first embodiment in the second embodiment is omitted. In the following description, the same reference numerals as those in the first embodiment indicate the same configurations as those in the first embodiment.

  In the forklift 200 according to the second embodiment, the operation unit 115 is provided with a low-speed mode switch (not shown) (operation means). And the controller 220 of 2nd Embodiment performs the step of FIG. 3 instead of the step of FIG. In FIG. 3, steps different from FIG. 2 are steps S200 and S201. In the second embodiment, when it is determined that the battery 106 is not operating normally (S101, No) and the alarm 114 (notification unit) is activated (S102), the low-speed mode switch is in a state of waiting for pressing. Transition (S200). If it is determined that the low-speed mode changeover switch has not been pressed (S200, No), the controller 220 holds the forklift 200 in the normal travel mode (S201). If it is determined that the low-speed mode switch is pressed (S200, Yes), the controller 220 executes steps after S103 in order to switch to the low-speed running mode.

  According to the second embodiment, a configuration is realized in which the operator switches to the low-speed running mode by operating the low-speed mode changeover switch after confirming the abnormality of the battery 106. If it is determined in S201 that the battery 106 has returned to normal operation, the controller 220 may be configured to return to normal operation from S100.

[Third Embodiment]
Hereinafter, a third embodiment will be described with reference to FIGS. 4 and 5. Note that the description of the same configuration as the first embodiment in the third embodiment is omitted. In the following description, the same reference numerals as those in the first embodiment indicate the same configurations as those in the first embodiment.

  In the forklift 300 (FIG. 4) according to the third embodiment, a configuration different from the first embodiment is a controller 320 and a step-up / down converter 316. The step-up / down converter 316 is connected between the battery 106 and the traveling inverter 104 and the generator inverter 103. The buck-boost converter 316 is a converter that converts the voltage supplied from the battery 106 into a larger voltage and supplies the converted voltage to the traveling inverter 104 and the generator inverter 103.

  FIG. 5 is a circuit diagram showing a more detailed configuration around the buck-boost converter 316 of FIG. The circuit diagram of FIG. 4 includes a battery 106, a relay 112, a fuse 113, an auxiliary machine 107, a step-up / down converter 316, a generator inverter 103, a generator motor 102, and a controller 320. Other configurations are omitted for the sake of clarity.

  The buck-boost converter 316 includes an inductor L, switching elements S7 and S8, and diodes D7 and D8. The generator inverter 103 includes switching elements S1 to S6 and diodes D1 to D6. In such a configuration, the voltage boosted from the battery 106 by the step-up / down converter 316 is supplied to the generator inverter 103. On the other hand, the voltage before boosting is supplied to the auxiliary machine 107.

  The controller 320 performs the same control as the control in the first or second embodiment in the low-speed traveling mode. As a result, switching of the switching elements S1 to S6 of the generator inverter 103 is stopped. Further, in the low speed running mode, the controller 320 keeps the switching element S7 on and keeps the switching element S8 off.

  When the battery 106 does not operate normally, the battery 106 is disconnected by the relay 112 and the fuse 113 as described above. Therefore, power from the battery 106 is not supplied to the auxiliary machine 107.

  However, when the controller 320 controls the switching elements S7 and S8 as described above in the low-speed traveling mode, the electric power from the generator motor 102 is supplied to the auxiliary machine 107 via the generator inverter 103. As a result, even when the battery 106 is disconnected, power is stably supplied to the auxiliary machine 107.

[Fourth Embodiment]
Hereinafter, a fourth embodiment will be described with reference to FIG. Note that the description of the same configuration as the first embodiment in the fourth embodiment is omitted. In the following description, the same reference numerals as those in the first embodiment indicate the same configurations as those in the first embodiment.

  The forklift 400 according to the fourth embodiment is different from the first embodiment in a controller 420 and a cargo handling drive 409. The cargo handling drive 409 is not connected to the drive shaft of the generator motor 102. The cargo handling drive 409 is configured to be driven by at least one of power supplied from the generator motor 102 via the generator inverter 103 and power supplied from the battery 106. Further, the fourth embodiment is configured such that a system voltage of a predetermined magnitude is supplied from the battery 106 to the entire system including the generator inverter 103, the traveling inverter 104, and the cargo handling drive 409. .

  Therefore, if the battery 106 does not operate normally and a predetermined system voltage is not supplied to the system, the cargo handling machine 409 may not operate stably.

  Therefore, the controller 420 limits the rotational speed of the engine 101 to such a magnitude as to ensure the predetermined system voltage not only when the traveling motor 105 is driven but also when the cargo handling machine 409 is driven. To do. That is, in step S107 of FIG. 2, it is determined not only whether the traveling motor 105 is driven, but also whether the cargo handling drive 409 is driven. If either is driven, the engine 101 is determined in S108. And the rotational speed of the traveling motor 105 is controlled. As a result, even when the cargo handling drive 409 as shown in FIG. 6 is provided, a configuration in which the forklift 400 can travel stably and the cargo handling operation can be performed stably is realized.

<Modification>
The above is a description of a preferred embodiment of the present invention. However, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the means for solving the problem. It can be changed.

  For example, in the above-described embodiment, the forklift has been described as an example, but the present invention may be applied to a work vehicle other than the forklift.

  Further, in the above-described embodiment, the controller 120 performs all the controls (1) to (4) in the low-speed traveling mode. However, only the control (1) for stopping the switching in the generator inverter 103 may be performed. Further, the control of (1) and the controls of (2) to (4) may be appropriately combined.

  In the above-described embodiment, even if the forklift has a configuration in which the engine 101 is started by the auxiliary starter 108 when the operator operates the operation unit 115 when the engine 101 is stopped due to an abnormality in the battery 106. Good. In the second embodiment, the traveling mode is switched to the low-speed traveling mode only when the engine 101 is stopped or not, only when the operator operates. However, when the engine 101 is stopped, the operation is switched to the low-speed traveling mode by the operation of the operator, and when the engine 101 is not stopped, it is automatically switched to the low-speed traveling mode as in the first embodiment. There may be.

  Moreover, in FIG.2 and FIG.3, after switching to low speed driving mode, the step which maintains the driving mode is shown. However, the controller 120 executes a step of determining whether or not the battery 106 has returned to normal operation after switching to the low-speed driving mode, and returning to the normal driving mode if it is determined that the battery 106 has returned to normal operation. May be.

  In the above-described embodiment, the traveling inverter 104 selectively takes the regeneration mode and the non-regeneration mode. However, a configuration may be adopted in which the regenerative operation of the travel motor 105 is stopped by separating the drive shaft of the travel motor 105 from the rotation of the shaft of the travel unit 111. In this case, the controller 120 switches between a state in which the driving force is transmitted to the shaft via the drive shaft in the travel motor 105 and a state in which the drive shaft is separated from the shaft, so that the regeneration mode and the non-regeneration mode are switched. Can be switched. Furthermore, a consumption circuit for consuming electric power regenerated from the traveling motor 105 in the non-regenerative mode may be provided, and the traveling inverter 104 may supply regenerative electric power to the consumption circuit.

It is a block diagram which shows the structure of the forklift which concerns on 1st Embodiment which is one Embodiment of this invention. FIG. 2 is a flowchart illustrating a series of steps in which the controller of FIG. 1 causes the controller to shift a travel mode from a normal travel mode to a low speed travel mode. It is a flowchart which shows a series of steps replaced with FIG. 2 which the controller of the forklift which concerns on 2nd Embodiment performs. It is a block diagram which shows the structure of the forklift truck concerning 3rd Embodiment. FIG. 5 is a circuit diagram showing a detailed configuration around a step-up / down inverter of FIG. 4. It is a block diagram which shows the structure of the forklift which concerns on 4th Embodiment.

Explanation of symbols

100, 200, 300, 400 Forklift 101 Engine 102 Generator motor 103 Generator inverter 104 Traveling inverter 105 Traveling motor 105 Battery 107 Auxiliary machine 108 Auxiliary starter 109, 409 Carrying drive 110 Fork 111 Traveling unit 114 Alarm 115 Operation unit 120, 220 , 320, 420 Controller 316 Buck-Boost Converter

Claims (8)

Engine,
Power storage means;
A normal mode in which the engine is driven by the engine to generate power and the generated power is output while being controlled by an inverter, and a rectification mode that is driven by the engine to generate power and that the generated power is converted from AC to DC without inverter control and output. And an inverter generator that selectively takes
A travel motor for vehicle travel driven by electric power supplied from at least one of the generator and the power storage means;
Determination means for determining whether or not the power storage means is operating normally;
Stop means for stopping power supply from the power storage means to the travel motor when the determination means determines that the power storage means is not operating normally;
When the determination means determines that the power storage means is operating normally, the inverter generator is caused to hold the normal mode, and the determination means determines that the power storage means is not operating normally And an inverter that controls the inverter generator to take the commutation mode. Engine,
Power storage means;
Inverter power generation, which is driven by the engine to generate power and selectively outputs a normal mode in which the generated power is output while being controlled by an inverter and a rectification mode in which the generated power is converted from an alternating current to a direct current without being controlled by the inverter Machine,
A travel motor for vehicle travel driven by electric power supplied from at least one of the generator and the power storage means;
Determination means for determining whether or not the power storage means is operating normally;
Stop means for stopping power supply from the power storage means to the travel motor when the determination means determines that the power storage means is not operating normally;
Informing means for informing an operator that the power storage means is not operating normally when the determination means determines that the power storage means is not operating normally;
An operation means for receiving an operation from an operator;
When the determination means determines that the power storage means is operating normally, the inverter generator is caused to hold the normal mode, and the notification means informs the operator that the power storage means is not operating normally. An industrial vehicle comprising: control means for notifying and then causing the inverter generator to take the commutation mode when the operation means receives an operation from an operator. The voltage supplied to the travel motor when the power storage means is operating normally is adjusted to a predetermined system voltage,
The control means is
When the determination unit determines that the power storage unit is not operating normally, the travel motor is driven so that the voltage supplied from the inverter generator is maintained in the vicinity of the predetermined system voltage. The industrial vehicle according to claim 1, wherein the rotational speed of the engine is controlled. It further comprises a travel inverter that controls the power supplied from the inverter generator to the travel motor,
The control means is
When the determination means determines that the power storage means is not operating normally, the rotation speed of the travel motor is equal to or less than the rotation speed corresponding to the upper limit of the output of the engine whose rotation speed is controlled by the control means. The industrial vehicle according to claim 3, wherein the traveling inverter is controlled so as to become. The travel inverter selectively takes a regeneration mode in which power can be regenerated from the travel motor and a non-regeneration mode in which power is not regenerated from the travel motor;
When the determination unit determines that the power storage unit is operating normally, the control unit causes the traveling inverter to hold the regeneration mode, and the determination unit determines that the power storage unit is not operating normally. The industrial vehicle according to any one of claims 1 to 4, wherein the non-regenerative mode is set to the traveling inverter when the determination is made. Further equipped with a cargo handling device,
In the normal mode, the inverter generator is a generator motor that selectively takes a generator mode driven by the engine to generate power and a motor mode driven by electric power supplied from the power storage means,
The cargo handling work device is driven by at least one of the inverter generator and the engine taking the electric motor mode,
The control means is
When the determination unit determines that the power storage unit is not operating normally, the cargo handling work device is driven only by the engine and is supplied from the inverter generator only when the traveling motor is driven. The industrial vehicle according to any one of claims 3 to 5, wherein the rotational speed of the engine is controlled so that a voltage to be generated is maintained in the vicinity of the predetermined system voltage. It further comprises a cargo handling work device driven by power supplied from at least one of the inverter generator and the power storage means,
When the determination unit determines that the power storage unit is not operating normally, the stop unit stops both power supply from the power storage unit to the cargo handling work device and the travel motor,
The control means is
When the determination means determines that the power storage means is not operating normally, both when the traveling motor is driven and when the cargo handling work device is driven, the inverter generator The industrial vehicle according to any one of claims 3 to 5, wherein the rotational speed of the engine is controlled so that the supplied voltage is maintained in the vicinity of the predetermined system voltage. A power supply source different from the power storage means;
The industrial vehicle according to any one of claims 1 to 7, further comprising a starter for the engine driven by the electric power supplied from the power supply source.

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