JP7012589B2 - Fuel cell type industrial vehicle - Google Patents

Description

The present invention relates to an industrial vehicle, and more particularly to a fuel cell type industrial vehicle.

In recent years, clean and energy-efficient fuel cells have been attracting attention as a drive source for vehicles such as industrial vehicles. In a fuel cell type industrial vehicle using a fuel cell as a drive source, a configuration is adopted in which the electric power generated by the fuel cell is stored in a power storage device and the power is supplied to the vehicle load via the power storage device (for example, patent documents). 1 and Patent Document 2).

In such a configuration, when electric power is supplied from the power storage device to the vehicle load, the voltage of the power storage device becomes low as the storage amount of the power storage device decreases. Therefore, in a fuel cell type industrial vehicle, in order to maintain the storage amount of the power storage device above a certain level, the voltage of the power storage device is detected by a sensor, and the power generation of the fuel cell is generated based on the detected voltage of the power storage device. It controls the state. Further, the fuel cell type industrial vehicle is equipped with a fuel cell unit including a compressor and a fuel cell stack, and when the operator operates the vehicle starting key from the stop position to the start position (hereinafter referred to as "key-on operation"). , The fuel cell stack is activated by sending air from the compressor to the fuel cell stack.

Japanese Unexamined Patent Publication No. 2006-351407 Japanese Unexamined Patent Publication No. 2009-23255

However, some failure may occur in the fuel cell type industrial vehicle, which may lead to a situation where the fuel cell stack cannot be started. In such a case, if the operator repeats the key-on operation many times without repairing the fuel cell type industrial vehicle, the fuel cell unit consumes power in an attempt to start the fuel cell stack, and the amount of electricity stored in the power storage device decreases. go. Then, when the voltage of the power storage device falls below the lower limit threshold voltage due to the decrease in the amount of storage, the fuel cell unit is regulated not to start the fuel cell stack even if the key-on operation is performed, in order to avoid further power consumption. The start regulation control is applied.

Whether or not the start regulation control is applied is determined by whether or not the voltage of the power storage device is less than the lower limit threshold voltage, and even after the serviceman or the like repairs the fuel cell type industrial vehicle to solve the failure, the power storage device It is applied unless the voltage recovers above the lower limit threshold voltage. Therefore, in order to release the start regulation control after repair, prepare a stabilized power supply as an external facility, connect it to the power storage device, and charge the power storage device with the power output by the stabilized power supply. It is necessary to recover the voltage above the lower limit threshold voltage.
In addition, charging from external equipment is different from charging with a normal fuel cell, so for example, when trying to restore the power storage device to full charge, a serviceman or the like will prevent the power storage device from becoming overcharged. It is necessary to charge slowly while checking the voltage of the power storage device. For this reason, it takes time and effort to recover the voltage of the power storage device after the repair of the fuel cell type industrial vehicle is completed.

The present invention has been made to solve the above problems, and an object thereof is to provide external equipment such as a regulated power supply when the voltage of the power storage device becomes low in the fuel cell unit and the start regulation control is applied. It is an object of the present invention to provide a fuel cell type industrial vehicle capable of recovering the voltage of a power storage device without using it.

The present invention includes a vehicle main body and a fuel cell unit mounted on the vehicle main body, and the fuel cell unit includes a fuel cell and a power storage device for storing electric power generated by the fuel cell, and the vehicle. The main body is a fuel cell type industrial vehicle operated by electric power supplied from the fuel cell unit via the power storage device, and has a first switch provided for controlling the vehicle main body and the fuel cell unit. A second switch provided to control the fuel cell stack, and a start-up regulation control that restricts the start-up of the fuel cell stack by a key-on operation when the voltage of the power storage device becomes less than a predetermined threshold voltage are applied. Also, when the first switch and the second switch are turned on so as to satisfy a predetermined condition, the fuel cell is activated to start charging the power storage device, and the power storage device is operated. A control unit for controlling to continue charging the power storage device until the voltage becomes equal to or higher than the predetermined threshold voltage is provided.

The fuel cell type industrial vehicle according to the present invention has a key switch whose on / off state is switched according to the operation of a key for starting the vehicle, and the control unit is in a period in which the key switch is in the on state. It may be determined whether or not the first switch and the second switch are turned on so as to satisfy the predetermined condition.

Further, the first switch may be an operation sensing switch whose on / off state is switched according to the movement of an operating member operated to control the operation of the vehicle body.

Further, the operation member may be a brake pedal, and the operation detection switch may be a brake pedal switch that is turned on when the brake pedal is pressed.

The vehicle body has an openable / closable cover that covers the fuel cell unit, and the second switch is a switch that is covered with the cover together with the fuel cell unit and can be operated by opening the cover. You may.

Further, the second switch may be an auto power off release switch for canceling the auto power off function.

Further, the control unit causes the fuel cell to start power generation with the maximum amount of power generation when the first switch and the second switch are turned on so as to satisfy the predetermined conditions. It may control the power generation state of the fuel cell stack .

According to the present invention, when the voltage of the power storage device becomes low in the fuel cell unit and the start regulation control is applied, the voltage of the power storage device is restored without using external equipment such as a regulated power supply. Can be done.

It is a block diagram schematically showing the structural example of the fuel cell type industrial vehicle which concerns on embodiment of this invention. It is a side view which shows the appearance of the fuel cell type industrial vehicle which concerns on embodiment of this invention. It is a figure which shows the power generation state of the fuel cell stack in the fuel cell type industrial vehicle which concerns on embodiment of this invention. It is a time chart explaining the restoration control process performed by the FC control device in the fuel cell type industrial vehicle which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Composition of fuel cell type industrial vehicle>
FIG. 1 is a block diagram schematically showing a configuration example of a fuel cell type industrial vehicle according to an embodiment of the present invention. The fuel cell type industrial vehicle according to the present invention is an industrial vehicle including a vehicle body 200 and a fuel cell unit 100 mounted on the vehicle body 200. In the embodiment of the present invention, the forklift 300 will be described as an example of the fuel cell type industrial vehicle.

(Fuel cell unit)
The fuel cell unit 100 includes a fuel cell stack 1, a hydrogen tank 2, and a compressor 3. The fuel cell stack 1 (hereinafter, also referred to as “FC stack”) has a configuration in which a plurality of power generation cells (not shown) are stacked. Each power generation cell is formed, for example, by sandwiching a solid polymer electrolyte between an anode electrode and a cathode electrode. The hydrogen tank 2 supplies hydrogen as a fuel gas for power generation to the FC stack 1. The compressor 3 supplies the FC stack 1 with air containing oxygen as an oxidant gas. A flow rate control valve 4 is provided between the FC stack 1 and the hydrogen tank 2. The flow rate control valve 4 adjusts the amount of hydrogen supplied from the hydrogen tank 2 to the FC stack 1.

The FC stack 1 generates electric energy by a chemical reaction between hydrogen supplied from the hydrogen tank 2 to the FC stack 1 through the flow control valve 4 and oxygen in the air supplied from the compressor 3 to the FC stack 1. That is, the FC stack 1 generates electricity by a chemical reaction between hydrogen and oxygen.

A cooling mechanism for cooling the FC stack 1 is connected to the FC stack 1. The cooling mechanism includes a cooling water channel 6, a water temperature sensor 7, a radiator 8, a water pump 9, and a cooling fan 10. The cooling water channel 6 is a water channel through which cooling water for cooling the FC stack 1 flows. A part of the cooling water channel 6 is arranged so as to be able to absorb the heat generated by the FC stack 1. As a result, heat exchange is performed between the FC stack 1 to be cooled and the cooling water flowing through the cooling water channel 6, and the FC stack 1 is cooled by this heat exchange.

The water temperature sensor 7 detects the temperature of the cooling water flowing through the cooling water channel 6. The water temperature sensor 7 is provided in the middle of the cooling water channel 6 from the FC stack 1 to the radiator 8. The temperature of the cooling water detected by the water temperature sensor 7 is input to the FC control device 5. The radiator 8 cools the cooling water flowing through the cooling water channel 6. The water pump 9 is a pump that circulates the cooling water flowing through the cooling water channel 6. The water pump 9 is provided in the middle of the cooling water channel 6 from the radiator 8 to the FC stack 1. The rotation speed of the water pump 9 is set based on the amount of power generated by the FC stack 1, and when the cooling fan 10 is rotating, the water pump 9 rotates at the maximum rotation speed to send cooling water.

The cooling fan 10 cools the radiator 8. The cooling fan 10 generates an air flow by the rotation of the cooling fan 10 itself. The air flow generated by the cooling fan 10 is blown onto the radiator 8 to cool the radiator 8.

A DC / DC converter 11 and a power storage device 12 are electrically connected to the output of the FC stack 1. The DC / DC converter 11 steps down the DC voltage output from the FC stack 1 to a predetermined DC voltage and outputs the DC voltage. The power storage device 12 serves to stabilize the DC power supplied to the vehicle load 20. The power storage device 12 has a charging function of storing the electric energy generated by the FC stack 1 by charging and a discharging function of discharging the electric energy stored by charging. The power storage device 12 is composed of, for example, a capacitor or a secondary battery. The electric power stored in the power storage device 12 by charging is consumed not only by the vehicle load 20 of the vehicle body 200 but also by the compressor 3 and the cooling fan 10 of the fuel cell unit 100.

A voltage sensor 13 is electrically connected to the power storage device 12. The voltage sensor 13 is a sensor that detects the voltage of the power storage device 12. The voltage value of the power storage device 12 detected by the voltage sensor 13 is input to the FC control device 5. A power generation sensor 14 is electrically connected between the FC stack 1 and the DC / DC converter 11. The power generation amount sensor 14 is a sensor that detects the amount of power generation generated by the FC stack 1. The power generation amount of the FC stack 1 detected by the power generation amount sensor 14 is input to the FC control device 5.

The FC control device 5 controls the processing and operation of the entire fuel cell unit 100. The FC control device 5 is configured by, for example, a microcomputer or the like. A compressor 3, a flow rate control valve 4, a cooling fan 10, and a DC / DC converter 11 are electrically connected to the FC control device 5 as control targets. Further, the water temperature sensor 7, the voltage sensor 13, and the power generation amount sensor 14 are electrically connected to the FC control device 5, respectively. These sensors are sensors that input reference information to the FC control device 5. The reference information is information referred to when the FC control device 5 controls the controlled object. Further, the auto power off release switch 15 and the lid sensing switch 16 are electrically connected to the FC control device 5, respectively. Both the auto power off release switch 15 and the lid sensing switch 16 are switches provided on the forklift 300 to control the fuel cell unit 100.

The auto power off release switch 15 is a switch for canceling the auto power off function of the forklift 300. The auto power off function is a function that automatically turns off the power of the forklift 300. The auto power off function is a function to prevent forgetting to turn off the key for starting the vehicle, and automatically turns on the power of the forklift 300 when the forklift 300 has been inactive or inactive for a predetermined time. Cut to.
On the other hand, the forklift 300 has an external power supply function of supplying the electric power generated by the fuel cell unit 100 to an external electronic device or the like. Then, the auto power off release switch 15 disables the auto power off function so that the power supply of the forklift 300 is not automatically cut off during the external power supply by the auto power off function when the external power supply function is used. It is a switch that is pressed.

As shown in FIG. 2, the auto power off release switch 15 is a switch that can be operated by lifting and opening the seat stand 201 provided in the vehicle body 200 of the forklift 300 in the A direction. The auto power off release switch 15 is, for example, a push button type switch, and is turned on when the switch is pressed, and is turned off otherwise. The seat stand 201 corresponds to an openable / closable cover that covers the fuel cell unit 100. The seat stand 201 has a seat 202 and a floor cover 203 integrally, and is provided so as to be openable and closable by a rotational operation about a support shaft (not shown).

During normal use of the forklift 300, the seat stand 201 is closed as shown by the solid line in FIG. 2, and the operator sits on the seat 202 to operate the forklift 300 in this closed state. Further, as shown by the alternate long and short dash line in FIG. 2, when the seat stand 201 is lifted in the A direction, the seat 202 and the floor cover 203 are lifted together with the seat stand 201. As a result, the seat stand 201 is opened.

When the seat stand 201 is closed, the auto power off release switch 15 is covered with the seat stand 201, so that the auto power off release switch 15 cannot be operated. On the other hand, when the seat stand 201 is open, the auto power off release switch 15 is exposed to the outside, so that the auto power off release switch 15 can be operated.

The lid sensing switch 16 is a switch that switches the on / off state according to the opening / closing state of the lid (not shown) that opens / closes the fuel gas filling hole. Specifically, the lid sensing switch 16 is turned off when the lid is closed and turned on when the lid is open. The fuel gas filling hole is provided in the fuel cell unit 100 for filling the hydrogen tank 2 with hydrogen as a fuel gas. The lid that opens and closes the fuel gas filling hole is normally closed and is opened when the fuel gas is filled.

Further, a gas leak detection sensor 17 is electrically connected to the FC control device 5 in order to detect the presence or absence of a gas leak during filling of the fuel gas. The FC control device 5 activates the gas leak detection sensor 17 when the lid detection switch 16 is turned on, and detects the presence or absence of a gas leak using the gas leak detection sensor 17. Further, when the FC control device 5 detects the occurrence of a gas leak by the gas leak detection sensor 17, the FC control device 5 performs a notification process for notifying the occurrence of the gas leak.

The FC control device 5 controls the output current taken out from the FC stack 1 by the DC / DC converter 11 by outputting a current command value to the DC / DC converter 11. Further, the FC control device 5 controls the rotation speed of the cooling fan 10 based on the power generation state of the FC stack 1.

The FC control device 5 controls the power generation state of the FC stack 1 by controlling the amount of air supplied by the compressor 3 and the amount of hydrogen supplied by the flow rate control valve 4. As the amount of hydrogen and the amount of oxygen supplied to the FC stack 1 increase, the amount of power generated by the FC stack 1 increases accordingly. Therefore, the FC control device 5 can control the power generation state of the FC stack 1 by controlling the compressor 3 and the flow rate control valve 4.

There are a plurality of power generation states of the FC stack 1 depending on the difference in the power generation amount of the FC stack 1. In the present embodiment, as an example, it is assumed that the FC stack 1 has four power generation states. The four power generation states are divided into power generation stop, low power generation, medium power generation, and high power generation. The power generation stop is a state in which the amount of power generated by the FC stack 1 is zero, that is, the FC stack 1 has stopped power generation. High power generation is a state in which the amount of power generated by the FC stack 1 is the maximum, that is, the highest power generation. Low power generation is a state in which the amount of power generated by the FC stack 1 is more than zero and less than the amount of power generated during medium power generation. In the medium power generation, the power generation amount of the FC stack 1 is larger than the power generation amount at the time of low power generation and less than the power generation amount at the time of high power generation.

The FC control device 5 controls the power generation state of the FC stack 1 to be one of one of power generation stop, low power generation, medium power generation, and high power generation. Specifically, as shown in FIG. 3, the FC control device 5 controls the power generation state of the FC stack 1 based on the voltage V of the power storage device 12 detected by the voltage sensor 13. Hereinafter, the method of controlling the power generation state of the FC stack 1 by the FC control device 5 will be described separately for the case of increasing the power generation amount and the case of reducing the power generation amount.

When increasing the amount of power generation of the FC stack 1, the FC control device 5 controls the compressor 3 and the flow rate control valve 4 to increase the amount of hydrogen and the amount of oxygen supplied to the FC stack 1. .. Further, when reducing the amount of power generation of the FC stack 1, the FC control device 5 controls the compressor 3 and the flow rate control valve 4, thereby reducing the amount of hydrogen and the amount of oxygen supplied to the FC stack 1. .. Further, when the power generation of the FC stack 1 is stopped, the FC control device 5 controls the compressor 3 and the flow rate control valve 4 to stop both the supply of hydrogen and the supply of oxygen to the FC stack 1. Become.

(When increasing the amount of power generation)
When the voltage V of the power storage device 12 falls below the predetermined threshold voltage Vth01 when the power generation state of the FC stack 1 is stopped, the FC control device 5 changes the power generation state of the FC stack 1 from the power generation stop to low power generation. Switch to. Further, the FC control device 5 changes the power generation state of the FC stack 1 from the low power generation when the voltage V of the power storage device 12 falls below the predetermined threshold voltage Vth12 when the power generation state of the FC stack 1 is low power generation. Switch to medium power generation. Further, when the power generation state of the FC stack 1 is medium power generation and the voltage V of the power storage device 12 is lower than the predetermined threshold voltage Vth23, the FC control device 5 changes the power generation state of the FC stack 1 from the medium power generation. Switch to high power generation.

(When reducing the amount of power generation)
When the voltage V of the power storage device 12 exceeds the predetermined threshold voltage Vth32 when the power generation state of the FC stack 1 is high power generation, the FC control device 5 changes the power generation state of the FC stack 1 from high power generation to medium power generation. Switch to. Further, when the power generation state of the FC stack 1 is medium power generation, the FC control device 5 changes the power generation state of the FC stack 1 from the medium power generation when the voltage V of the power storage device 12 exceeds the predetermined threshold voltage Vth21. Switch to low power generation. Further, the FC control device 5 changes the power generation state of the FC stack 1 from the low power generation when the voltage V of the power storage device 12 exceeds the predetermined threshold voltage Vth10 when the power generation state of the FC stack 1 is low power generation. Switch to power generation stop.

Returning to the description of FIG. 1, the vehicle load 20 is electrically connected to the output side of the DC / DC converter 11 via the power storage device 12. In the present embodiment, the traveling motor 21 and the cargo handling motor 22 are given as an example of the vehicle load 20.

(Vehicle body)
The vehicle body 200 includes a traveling device (not shown) that travels with the traveling motor 21 as a drive source, a cargo handling device (not shown) that operates with the cargo handling motor 22 as a drive source, and a traveling operation and cargo handling device by the traveling device. It includes an operation member (described later) operated by an operator to control the cargo handling operation, and a vehicle control device 30 for controlling the processing and operation of the entire vehicle body 200. The vehicle control device 30 and the FC control device 5 are configured to be communicable with each other by, for example, a CAN (Controller Area Network).

The traveling motor 21 and the cargo handling motor 22 constituting the vehicle load 20 are each electrically connected to the vehicle control device 30. Further, the traveling motor 21 and the cargo handling motor 22 are each driven by the DC electric power supplied from the fuel cell unit 100 to the vehicle body 200. The vehicle control device 30 is configured by, for example, a microprocessor or the like. The vehicle control device 30 individually controls the traveling motor 21 and the cargo handling motor 22 to be controlled.

The vehicle control device 30 is electrically connected to an operation sensing switch that switches between on and off states according to the movement of an operating member operated to control the operation of the vehicle body 200. In the present embodiment, an accelerator pedal, a brake pedal, a lift lever, and a tilt lever (not shown) are given as examples of operating members. The accelerator pedal and the brake pedal are operated to control the traveling operation of the vehicle body 200. The lift lever and the tilt lever are operated to control the cargo handling operation of the vehicle body 200. Further, in the present embodiment, the accelerator pedal switch 33, the brake pedal switch 34, the lift lever switch 35, and the tilt lever switch 36 are electrically supplied to the vehicle control device 30 as operation sensing switches corresponding to the above-mentioned operation members. It is connected. The accelerator pedal switch 33, the brake pedal switch 34, the lift lever switch 35, and the tilt lever switch 36 are all switches provided on the forklift 300 to control the vehicle body 200.

The accelerator pedal switch 33 is a switch that switches the on / off state according to the movement of the accelerator pedal. The accelerator pedal switch 33 is turned on when the accelerator pedal is pressed, and turned off when the accelerator pedal is not pressed. The brake pedal switch is a switch that switches between on and off states according to the movement of the brake pedal. The brake pedal switch 34 is turned on when the brake pedal is pressed, and turned off when the brake pedal is not pressed.

The lift lever switch 35 is a switch that switches the on / off state according to the movement of the lift lever. The lift lever switch 35 is turned on when the lift lever is in the fork ascending command position (backward tilting position) or fork lowering commanding position (forward tilting position), and is turned off when the lift lever is in the neutral position. .. The tilt lever switch 36 is a switch that switches the on / off state according to the movement of the tilt lever. The tilt lever switch 36 is turned on when the tilt lever is in the mast forward tilt command position (forward tilt position) or mast backward tilt command position (backward tilt position), and is in the off state when the tilt lever is in the neutral position. Will be.

Further, a key switch 31 is electrically connected to the vehicle control device 30. The key switch 31 is a switch whose on / off state is switched according to the operation of a key for starting a vehicle (not shown). There are two types of key operations for starting the vehicle: on operation and off operation. The on operation is an operation of inserting the key for starting the vehicle into a key hole or the like and turning the key from the stop position to the start position, that is, a key on operation. The off operation is an operation of turning the vehicle starting key from the starting position to the stopping position, that is, a key-off operation. The key switch 31 is turned on when the vehicle starting key is in the starting position, and turned off when the vehicle starting key is in the stopped position.

<Processing and operation of fuel cell type industrial vehicles>
Next, as an example of the processing and operation of the fuel cell type industrial vehicle according to the embodiment of the present invention, the start control processing applied when starting the forklift 300 and the start control processing applied when the forklift 300 is recovered from a failure or the like are applied. The recovery control process will be described.

(Start control process)
When starting the forklift 300, the operator inserts a key for starting the vehicle into a key hole or the like to perform a key-on operation. As a result, the key switch 31 is switched from the off state to the on state. When the key switch 31 is turned on, a signal notifying that effect (hereinafter, also referred to as “key-on signal”) is output from the vehicle control device 30 to the FC control device 5, and the FC control device 5 receives this signal and FC. Start stack 1. At that time, the FC control device 5 reads the voltage V of the power storage device 12 from the voltage sensor 13 before starting the FC stack 1. At this time, if the voltage V of the power storage device 12 is equal to or higher than the lower limit threshold voltage Vmin, the FC control device 5 permits the activation of the FC stack 1, and if it is less than the lower limit threshold voltage Vmin, the FC control device 5 allows the FC stack 1 to start. Is not allowed to start.
That is, when the voltage V of the power storage device 12 becomes less than the lower limit threshold voltage Vmin, the FC control device 5 regulates that the FC stack 1 is not started even if the key switch 31 is turned on by the key-on operation.
When the lower limit voltage voltage Vmin continues to consume the power of the power storage device 12 without supplying power to the power storage device 12, the amount of power stored in the power storage device 12 becomes excessively small, and the power storage device 12 It is a preset threshold voltage in order to avoid further power consumption so as not to adversely affect the characteristics.

Further, the lower limit threshold voltage Vmin does not adversely affect the power storage device 12 when the FC stack 1 is started, and the power storage device 12 when the minimum power required for starting the FC stack 1 remains in the power storage device 12. Assuming that the voltage is Vp, it is set so as to satisfy the condition of Vmin> Vp. This condition is set with a certain margin so that the voltage of the power storage device 12 does not become Vp or less even due to some subsequent discharge or the like. The voltage Vp is determined by the type and structure of the power storage device 12, and the lower limit threshold voltage Vmin is used for experiments or calculations based on the value of the voltage Vp in consideration of information such as vehicle characteristics and usage conditions. Determine based on. Therefore, even if the voltage of the power storage device 12 is less than the lower limit threshold voltage Vmin, if the voltage is Vp or more, the power for starting the FC stack 1 is possessed without adversely affecting the characteristics of the power storage device. Further, the lower limit threshold voltage Vmin has a lower voltage value than any of the three threshold voltages Vth01, Vth12, and Vth23 (see FIG. 3) applied when controlling the power generation state of the FC stack 1. Set.

When the FC control device 5 permits the activation of the FC stack 1, the FC control device 5 uses the compressor when the key-on signal is output from the vehicle control device 30, that is, when the key switch 31 is turned on. 3 is activated to supply air to the FC stack 1, thereby activating the FC stack 1. However, when the forklift 300 or the fuel cell system has some trouble, even if the FC control device 5 tries to start the FC stack 1, the failure directly or indirectly causes the FC stack 1 to start. There are things you can't do. Since the power of the power storage device 12 is used when the FC stack 1 is started, the amount of electricity stored in the power storage device 12 is increased when the start is repeated, specifically, the key switch 31 is repeatedly switched from the off state to the on state. It will decrease.

Then, when the voltage V of the power storage device 12 becomes less than the lower limit threshold voltage Vmin, the FC control device 5 regulates the start of the FC stack 1 even if the key switch 31 is turned on by the key-on operation. To apply. That is, in the fuel cell unit 100, the start regulation control that restricts the start of the FC stack 1 by the key-on operation is applied by the FC control device 5. When the FC control device 5 disallows the activation of the FC stack 1, the FC control device 5 does not activate the FC stack 1 even when the key-on signal is output from the vehicle control device 30. The start regulation control is applied unless the voltage V of the power storage device 12 is restored to the lower limit threshold voltage Vmin or more.
Since the FC stack 1 cannot be started unless air is supplied from the compressor 3, the start of the compressor 3 and the start of the FC stack 1 are substantially synonymous.

(Recovery control processing)
When the above-mentioned start regulation control is applied, the voltage V of the power storage device 12 remains less than the lower limit threshold voltage Vmin even if the serviceman or the like subsequently repairs the forklift 300 to solve the failure. Therefore, in order to return the FC stack 1 to a state in which the FC stack 1 can be started by the key-on operation, it is necessary to recover the voltage V of the power storage device 12 to the lower limit threshold voltage Vmin or more. Therefore, the FC control device 5 performs the following recovery control processing. In this embodiment, the key switch 31 and the other two switches, that is, the auto power off release switch 15 and the accelerator pedal switch 33, are applied to perform the recovery control process. In this application example, the accelerator pedal switch 33 corresponds to the first switch, and the auto power off release switch 15 corresponds to the second switch.

FIG. 4 is a time chart illustrating the recovery control process performed by the FC control device.
First, the key switch 31 is turned on by a key-on operation by a serviceman or the like. However, if the voltage V of the power storage device 12 is less than the lower limit threshold voltage Vmin, the FC control device 5 does not start the FC stack 1 because the start regulation control by the key-on operation is applied. Then, the FC control device 5 is turned on so that the auto power off release switch 15 and the accelerator pedal switch 33 satisfy a predetermined condition by an operation by a serviceman or the like while the key switch 31 is turned on. Judge whether or not. The on / off state of the accelerator pedal switch 33 is notified from the vehicle control device 30 to the FC control device 5, and the FC control device 5 is configured to determine the on / off state of the accelerator pedal switch 33 in response to this notification. In the present embodiment, as an example, when both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on, the FC control device 5 is turned on so that the two switches satisfy a predetermined condition. It shall be judged that it has become.

Here, a specific operation method for turning on both the auto power off release switch 15 and the accelerator pedal switch 33 will be described. There are three methods for this operation. The first operation method is a case of operating so as to press the accelerator pedal while pressing the auto power off release switch 15. The second operation method is a case of operating so as to press the auto power off release switch 15 while pressing the accelerator pedal. The third operation method is a case where both the auto power off release switch 15 and the accelerator pedal are pressed at the same time.

In the first operation method, after the auto power off release switch 15 is turned on, the accelerator pedal switch 33 is turned on. Then, at the timing when the accelerator pedal switch 33 is turned on, both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on. In the second operation method, after the accelerator pedal switch 33 is turned on, the auto power off release switch 15 is turned on. Then, at the timing when the auto power off release switch 15 is turned on, both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on. In the third operation method, the auto power off release switch 15 and the accelerator pedal switch 33 are simultaneously turned on, whereby the auto power off release switch 15 and the accelerator pedal switch 33 are both turned on.

Regarding the auto power off release switch 15, the auto power off release switch 15 is hidden under the seat stand 201 during normal use of the forklift 300. Therefore, in order to operate the auto power off release switch 15, it is necessary to lift the seat stand 201 to expose the auto power off release switch 15 to the outside. Further, in order to turn on both the auto power off release switch 15 and the accelerator pedal switch 33, for example, an operator such as an operator or a serviceman standing beside the forklift 300 can use one hand to turn on the auto power off release switch. It is necessary to operate 15 and operate the accelerator pedal with the other hand.

In the example shown in FIG. 4, first, the key switch 31 rises from the off state to the on state at the timing T0, and then the auto power off release switch 15 rises from the off state to the on state at the timing T1. Next, the accelerator pedal switch 33 rises from the off state to the on state at the timing T2 within the period in which the auto power off release switch 15 is held in the on state. After that, both the auto power off release switch 15 and the accelerator pedal switch 33 are down from the on state to the off state at the timing T3. In this case, it can be seen that the operator has operated the auto power off release switch 15 and the accelerator pedal according to the first operation method described above.

In such a case, the FC control device 5 determines that both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on at the timing T2. Further, when the accelerator pedal switch 33 is turned on at the timing T2, the FC control device 5 permits the start of the FC stack 1 even in the situation where the above-mentioned start restriction control is applied. That is, the FC control unit 5 activates the FC stack 1 at the timing T2 when both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on. As a result, power generation by the FC stack 1 starts.
When starting the FC stack 1, even if the voltage of the power storage device 12 is less than the lower limit threshold voltage Vmin as described above, if the voltage is Vp or higher, the FC stack 1 is started without adversely affecting the characteristics of the power storage device 12. Has the power to do. If the failure of the forklift 300 is resolved, the FC stack 1 can be started by using the electric power remaining in the power storage device 12, and the power generation of the FC stack 1 can be started. At that time, the FC control device 5 controls the power generation state of the FC stack 1 so that the FC stack 1 starts power generation with the maximum power generation amount Wmax, that is, high power generation.

When the power generation of the FC stack 1 is started in this way, the electric power generated by the FC stack 1 is stored in the power storage device 12, thereby charging the power storage device 12. Therefore, the voltage V of the power storage device 12 gradually increases. While charging the power storage device 12, the FC control device 5 reads the voltage V of the power storage device 12 from the voltage sensor 13. Then, for example, at the timing T4, when the voltage V of the power storage device 12 reaches a predetermined upper limit threshold voltage Vmax, that is, when the power storage device 12 is in a fully charged state, the FC control device 5 causes the FC stack 1 to be in a fully charged state. Power generation is automatically stopped, and then the normal control mode is entered. As described with reference to FIG. 3, the normal control mode is a control mode for controlling the power generation state of the FC stack 1 based on the voltage V of the power storage device 12.
When starting the FC stack 1 in the recovery control process, the FC control device 5 determines whether or not the voltage of the power storage device 12 is Vp or higher. If the voltage of the power storage device 12 is less than Vp, the activation of the FC stack 1 is disallowed. In this case, it is necessary to prepare a stabilized power supply as an external facility and cancel the start regulation control.
Therefore, the FC stack 1 of the recovery control process is started when the voltage of the power storage device is less than Vmin and more than Vp.

<Effect of embodiment>
In the embodiment of the present invention, even in a situation where the voltage V of the power storage device 12 is less than the lower limit threshold voltage Vmin and the start regulation control for restricting the start of the fuel cell stack by the key-on operation is applied, the auto operation is performed. When both the power-off release switch 15 and the accelerator pedal switch 33 are turned on, the FC control device 5 activates the FC unit 1 to start charging the power storage device 12. Therefore, when the voltage V of the power storage device 12 becomes low in the fuel cell unit 100 and the start regulation control is applied, the recovery control process is performed as an urgent process to use external equipment such as a stabilized power supply. Even if this is not done, the voltage V of the power storage device 12 can be recovered.

Further, in the embodiment of the present invention, the accelerator pedal switch 33 provided for controlling the vehicle body 200 is used as the first switch, while the auto power off release switch 15 provided for controlling the fuel cell unit 100 is used. Is the second switch. In this case, in normal use of the forklift 300, the accelerator pedal switch 33 is turned on when the operator depresses the accelerator pedal while operating the forklift 300. On the other hand, the auto power off release switch 15 is not a switch for operating the forklift 300. Therefore, the auto power off release switch 15 is not accidentally pressed during normal use of the forklift 300. Therefore, according to the embodiment of the present invention, the auto power off release switch 15 is used for the recovery control process for recovering the voltage V of the power storage device 12, which is an application different from the normal use of the forklift 300. Two switches such as the accelerator pedal switch 33 can be effectively used.

Further, in normal use of the forklift 300, since the auto power off release switch 15 is hidden by the seat stand 201, the operator cannot operate the auto power off release switch 15 during normal use of the forklift 300. Therefore, the voltage V of the power storage device 12 can be recovered by using the first switch and the second switch only in the recovery control process, which is an urgent process.

Further, as a means for avoiding the application of the start regulation control, the application of the start regulation control is canceled so that the FC control device 5 permits the start of the FC unit 1 even if the voltage V of the power storage device 12 is less than the lower limit threshold voltage Vmin. It is conceivable to provide a new switch for this purpose. However, the current forklift has a large space limitation, and it is difficult to newly install such a switch. In addition, it is costly to install a new switch. On the other hand, in the embodiment of the present invention, the auto power off release switch 15 and the accelerator pedal switch 33, which are existing switches included in the forklift, are used. Therefore, it is possible to start the FC unit 1 without being restricted by space and without increasing the cost and avoiding the application of the start regulation control.

Further, in the embodiment of the present invention, when both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on, the FC control device starts power generation with the maximum power generation amount of the FC stack 1. 5 controls the power generation state of the FC stack 1. Therefore, the power storage device 12 can be rapidly charged and the voltage V of the power storage device 12 can be recovered in a short time. Further, it is possible to shorten the time from the start of charging of the power storage device 12 until the power storage device 12 is fully charged as much as possible.

<Modification example, etc.>
The technical scope of the present invention is not limited to the above-described embodiment, and includes various modifications and improvements as long as the specific effects obtained by the constituent requirements of the invention and the combination thereof can be derived.

For example, in the above embodiment, an example in which the power generation state of the FC stack 1 is controlled by dividing it into four categories of power generation stop, low power generation, medium power generation, and high power generation is shown, but the present invention is not limited to this. For example, a configuration may be adopted in which the power generation state of the FC stack 1 is controlled by dividing it into two, three, or five or more.

Further, in the above embodiment, when the FC unit 1 is started by the recovery control process, the power generation of the FC stack 1 is started with high power generation, but the present invention is not limited to this, and medium power generation or low power generation is not limited to this. You may start the power generation of FC stack 1 with.

Further, in the above embodiment, the accelerator pedal switch 33, which is one of the operation sensing sensors, has been described as an example as the first switch applied to the recovery control process, but the present invention is not limited to this. For example, instead of the accelerator pedal switch 33, the brake pedal switch 34, the lift lever switch 35, or the tilt lever switch 36 may be applied to the recovery control process. Further, a switch for turning on the light of the vehicle body 200 and a switch for sounding the horn may be applied to the recovery control process as the first switch.

In particular, when the brake pedal switch 34 is applied to the recovery control process, the corresponding brake pedal becomes an operating member operated when the traveling operation of the vehicle body 200 is forcibly stopped. Therefore, it is possible to give the operator who operates the brake pedal during the restoration control process a sense of security that "the vehicle body 200 does not move if the brake pedal is pressed". When the brake pedal switch 34, the lift lever switch 35, or the tilt lever switch 36 is applied to the recovery control process, the vehicle control device 30 notifies the FC control device 5 of the on / off state of the sensor to be actually applied, and this notification. In response to this, the FC control device 5 determines the on / off state of the sensor.

Further, in the above embodiment, the FC control device 5 determines whether or not both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on during the period when the key switch 31 is turned on. However, the present invention is not limited to this. For example, even when the key for starting the vehicle is pulled out from the key hole or the like and the key switch 31 is in the off state, whether or not both the auto power off release switch 15 and the accelerator pedal switch 33 are in the on state is FC. The control device 5 may make a determination, and the FC unit 1 may be controlled to be activated based on the determination result. In that case, the FC control device 5 automatically stops the power generation of the FC stack 1 when the power storage device 12 is fully charged, and thereafter, by the key-on operation as in the normal start-up. FC unit 1 can be started.

Further, in the above embodiment, when both the auto power off release switch 15 and the accelerator pedal switch 33 are turned on, the FC control device 5 is turned on so that the two switches satisfy a predetermined condition. However, the present invention is not limited to this. That is, the predetermined conditions used as the judgment criteria in the FC control device 5 can be changed in various ways. For example, of the first switch and the second switch, the time from when one switch is turned on to when the other switch is turned on is measured by a timer or the like, and the measured time is determined in advance. A configuration may be adopted in which it is determined that the two switches are turned on so as to satisfy a predetermined condition when the specified time is within the specified time (for example, within 5 seconds). In addition to this, for example, when two switches are turned on in a predetermined order, a configuration is adopted in which it is determined that the two switches are turned on so as to satisfy a predetermined condition. You may.

Further, in the above embodiment, when the first switch and the second switch are both turned on under the condition that the activation regulation control by the key-on operation is applied, the fuel cell stack is activated to store electricity. The device is controlled to start charging, but the present invention is not limited to this.
That is, regardless of whether the start regulation control by the key-on operation is applied, when the first switch and the second switch are turned on so as to satisfy a predetermined condition, the fuel cell stack is started. A configuration may be adopted in which the power storage device is controlled to start charging. As a result, even when recovery control processing is required due to various factors, the fuel cell stack is activated and the power storage device is started to be charged by appropriately operating the first switch and the second switch. be able to.

Further, in the above embodiment, the forklift has been described as an example of the fuel cell type industrial vehicle, but the present invention is not limited to this, and the present invention is not limited to this, for example, to other fuel cell type industrial vehicles such as a towing car. May be applied. When applied to a towing vehicle, the fuel cell unit may be mounted under the bonnet arranged at the front or rear of the driver's seat, so the equivalent of the cover covering the fuel cell unit is the bonnet.

1 FC stack (fuel cell stack), 5 FC control device (control unit), 12 power storage device, 15 auto power off release switch (second switch), 33 accelerator pedal switch (first switch), 34 brake pedal switch (Operation detection switch), 100 fuel cell unit, 200 vehicle body, 201 seat stand (cover), 300 forklift.

Claims (8)

The vehicle body includes a vehicle body and a fuel cell unit mounted on the vehicle body, and the fuel cell unit has a fuel cell stack and a power storage device for storing electric power generated by the fuel cell stack, and the vehicle body is , A fuel cell type industrial vehicle operated by electric power supplied from the fuel cell unit via the power storage device.
A first switch provided to control the vehicle body,
A second switch provided to control the fuel cell unit, and
Even in a situation where the voltage of the power storage device becomes less than a predetermined threshold voltage and the start regulation control for restricting the start of the fuel cell stack by the key-on operation is applied, the first switch and the second switch are applied. Is turned on so as to satisfy a predetermined condition, the fuel cell stack is activated to start charging the power storage device, and the power storage device is charged until the voltage of the power storage device becomes equal to or higher than the predetermined threshold voltage. A control unit that controls the device to continue charging,
Fuel cell type industrial vehicle equipped with. It has a key switch that switches on and off according to the operation of the key for starting the vehicle.
The control unit determines whether or not the first switch and the second switch are turned on so as to satisfy the predetermined condition during the period when the key switch is turned on. Item 1. The fuel cell type industrial vehicle according to item 1. The fuel cell type industrial vehicle according to claim 1 or 2, wherein the first switch is an operation sensing switch whose on / off state is switched according to the movement of an operating member operated to control the operation of the vehicle body. .. The fuel cell type industrial vehicle according to claim 3, wherein the operating member is a brake pedal, and the operation sensing switch is a brake pedal switch that is turned on when the brake pedal is pressed. The vehicle body has an openable / closable cover that covers the fuel cell unit.
The fuel cell type industrial vehicle according to any one of claims 1 to 4, wherein the second switch is a switch that is covered with the cover together with the fuel cell unit and can be operated by opening the cover. The fuel cell type industrial vehicle according to claim 5, wherein the second switch is an auto power off release switch for canceling the auto power off function. The control unit causes the fuel cell stack to start power generation with the maximum amount of power generation when the first switch and the second switch are turned on so as to satisfy the predetermined conditions. The fuel cell type industrial vehicle according to any one of claims 1 to 6, which controls the power generation state of the fuel cell stack . The vehicle body includes a vehicle body and a fuel cell unit mounted on the vehicle body, and the fuel cell unit has a fuel cell stack and a power storage device for storing electric power generated by the fuel cell stack, and the vehicle body is , A fuel cell type industrial vehicle operated by electric power supplied from the fuel cell unit via the power storage device.
A first switch provided to control the vehicle body,
A second switch provided to control the fuel cell unit, and
When the first switch and the second switch are turned on so as to satisfy a predetermined condition, the fuel cell stack is activated to start charging the power storage device, and the voltage of the power storage device is started. A control unit that controls to continue charging the power storage device until the voltage becomes equal to or higher than a predetermined threshold voltage.
Fuel cell type industrial vehicle equipped with.

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