JP3156582U - Hybrid industrial vehicle - Google Patents

Abstract

An object of the present invention is to provide a hybrid industrial vehicle that does not reduce the work efficiency even when the discharge amount of the battery is limited when the battery is at a low temperature or a high temperature, or when the charging rate is lowered.
An engine, a generator motor, a cargo handling pump, a battery, and a travel motor are provided. The cargo handling pump 4 is driven by a generator motor 3 that is driven by electric power stored in the engine 2 or the battery 6, and the traveling motor 7 is driven by electric power stored in the battery 6. The battery 6 is set so that the discharge allowable power of the battery 6 becomes smaller than the limit value when the battery is at a low temperature and at a high temperature and when the charging rate of the battery is lowered. When the allowable discharge power of the battery 6 is smaller than the limit value, the hybrid ECU 9 increases the idling rotational speed.
[Selection] Figure 1

Description

  The present invention relates to a hybrid industrial vehicle.

In recent years, for example, a hybrid industrial vehicle as shown in FIG. 5 has been proposed.
In the hybrid forklift 51, an engine 52, a generator motor 53, and a cargo handling pump 54 are coaxially connected. When the cargo handling pump 54 is driven, the hydraulic oil in the hydraulic oil tank 55 is supplied to the cargo handling device 57 via the cargo handling valve 56, and the cargo handling work by the cargo handling device 57 is performed.
The generator motor 53 has a function as a generator that generates power by being driven by the power of the engine 52 and a function as an electric motor that is driven through the inverter 59 by the electric power stored in the battery 58.
On the other hand, the traveling motor 60 is driven via the inverter 59 by the power generated by the generator motor 53 and the power stored in the battery 58. The power of the traveling motor 60 is transmitted to the traveling device 61, and the hybrid forklift 51 travels. The electric motor 60 for driving is normally driven by being supplied with the electric power generated by the generator motor 53, and the electric power stored in the battery 58 is supplied when the electric power consumed is large, such as during acceleration. .
The engine 52, the inverter 59, and the cargo handling valve 56 are controlled by the hybrid ECU 62.
The engine 52 rotates at the idling speed when the hybrid forklift 51 is stopped and does not carry out work or cargo handling.

When the hybrid forklift 51 starts traveling, immediately after the traveling starts, the rotational speed of the engine 52 increases from the idling rotational speed, so that the electric power generated by the generator motor 53 is small. Therefore, the electric power generated by the generator motor 53 is smaller than the electric power consumed by the traveling motor 60, and the electric power becomes insufficient. Therefore, the electric power stored in the battery 58 is supplied to the electric motor 60 for traveling until the engine speed is increased and the required electric power generation amount is obtained by the generator motor 53 to compensate for the shortage of electric power.
When the cargo handling operation is started, the engine 52 has a small torque immediately after the cargo handling operation is started, and therefore the torque of the engine 52 is small. Therefore, the torque of the engine 52 is smaller than the torque required by the cargo handling pump 54 for the cargo handling operation. Therefore, the electric power stored in the battery 58 is supplied to the generator motor 53 until the engine speed is sufficiently increased and a necessary torque is obtained. The generator motor 53 is driven as an electric motor by the supply of electric power stored in the battery 58, and the deficiency in the torque of the engine 52 is compensated for by driving the generator motor 53.
In this way, at the start of traveling or at the start of cargo handling, the power stored in the battery 58 is supplied to the traveling motor 60 or the generator motor 53 to assist the shortage of the output of the engine 52 with the power of the battery 58. Yes.

Further, in the hybrid vehicle control device disclosed in Patent Document 1, the idling speed is increased when the amount of charge (remaining charge) of the battery falls below a predetermined threshold value (second threshold value). And increasing the amount of charge to the battery.
This increases the remaining battery charge and prevents the battery from being overdischarged.

JP 2001-50077 A

However, in the conventional hybrid forklift 51 shown in FIG. 5, a nickel metal hydride battery or a lithium ion battery is used as the battery 58, and the nickel metal hydride battery or the lithium ion battery has a characteristic when the battery 58 is at a low temperature or a high temperature. Alternatively, when the remaining charge amount is low, it is necessary to limit the amount of power discharged from the battery 58.
For this reason, when the battery 58 is at a low temperature or a high temperature, or when the remaining charge is low, the supply of the electric power stored in the battery 58 to the electric motor 60 and the generator motor 53 is restricted. Therefore, when the operation of running or cargo handling is started when the battery 58 is at a low temperature or a high temperature, or when the remaining charge amount is low, the power of the battery 58 depends on the shortage of the output of the engine 52. Assistance will not be sufficient. Specifically, sufficient electric power cannot be supplied for the shortage of electric power of the electric motor 60 for traveling, or the engine 52 cannot be sufficiently assisted by the generator motor 53.
As a result, when the running or cargo handling operation is started when the battery 58 is at a low temperature or a high temperature, or when the remaining charge level is low, the capacity of the forklift traveling or the cargo handling operation is limited, and the work efficiency is lowered. There is a problem that it will.

  Further, in the hybrid vehicle control device disclosed in Patent Document 1, when the remaining charge of the battery is low, the idling rotational speed is increased in order to charge the battery. It does not deal with the limitation of the ability of traveling and cargo handling work due to restrictions.

  The present invention has been made in view of the above problems, and the purpose of the present invention is when the amount of discharge is limited when the battery is cold or hot, or when the remaining charge level is low. The object is to provide a hybrid industrial vehicle that does not reduce the work efficiency.

  In order to solve the above-mentioned problem, the invention according to claim 1 is driven by an engine, a battery, a function connected to the engine and generating electricity by driving the engine, and electric power supplied from the battery. A cargo handling generator motor having a function as an electric motor to be driven, a cargo handling pump driven by the engine or the cargo handling generator motor, and a power generated by the cargo handling generator motor or driven by power from the battery. A traveling motor, the engine, the battery, the cargo handling generator motor, a control means for controlling the traveling motor, a temperature detecting means for detecting the temperature of the battery, and a charge for detecting a remaining charge of the battery A remaining amount detecting means; at least one of the detected temperature of the battery and the remaining charge of the battery; Discharge allowable power calculation means for calculating the discharge allowable power of the battery based on the information, and the control means controls the cargo handling generator motor and the traveling motor based on the calculated discharge allowable power, When the discharge allowable power is smaller than a limit value, the idling speed of the engine is increased.

According to the first aspect of the present invention, the discharge allowable power calculation means calculates the discharge allowable power based on at least one of the battery temperature and the remaining battery charge.
When the calculated discharge allowable power is smaller than the limit value and the discharge amount is limited, the engine idling speed is increased.
As described above, at the start of traveling and at the start of cargo handling, when the assist by the battery power is not sufficiently performed due to the limitation of the discharge amount of the battery, the control means increases the idling rotational speed and increases the output of the engine. . Therefore, the forklift traveling and cargo handling capabilities are not limited, and the working efficiency of the forklift is not reduced.

  The invention according to claim 2 is the invention according to claim 1, wherein the control means increases the idling speed of the engine as the calculated discharge allowable power becomes smaller than the limit value. The engine is controlled to be large.

  According to the second aspect of the present invention, the engine controls the idling speed according to the magnitude of the discharge allowable power, so that the idling speed does not increase more than necessary. Therefore, an increase in fuel consumption due to an increase in the idling speed can be minimized.

  Invention of Claim 3 is an invention of Claim 2, Comprising: The said discharge allowable electric power becomes a low temperature area | region where the temperature of a battery becomes below 1st temperature, and the temperature of a battery becomes above 2nd temperature. The control means is set to be smaller than a limit value in the high temperature region, and the control means controls the engine so that the idling speed of the engine increases as the battery temperature decreases in the low temperature region, In the region, the engine is controlled such that the idling speed of the engine increases as the temperature of the battery increases.

According to the third aspect of the present invention, in the low temperature region where the temperature is equal to or lower than the first temperature, the discharge allowable power is smaller than the limit value as the battery temperature is lower. Therefore, the idling speed is decreased as the battery temperature is lower. In the high temperature region where the temperature is higher than the second temperature, the discharge allowable power is smaller than the limit value as the battery temperature is higher. Therefore, the idling speed is increased as the battery temperature is higher.
Thereby, the idling speed can be appropriately increased with respect to the limit value of the battery discharge amount in the low temperature region and the high temperature region of the battery.

  According to the present invention, even when the battery discharge amount is limited when the battery temperature is low or high, or when the remaining charge level is low, the work efficiency is reduced at the start of traveling or at the start of cargo handling work. It is possible to carry out operations such as traveling and cargo handling.

It is a block diagram which shows the structure of the hybrid type industrial vehicle which concerns on embodiment of this invention. It is a figure which shows the map of the discharge allowable electric power of the battery of the hybrid type industrial vehicle which concerns on embodiment of this invention. It is a figure which shows the engine speed and torque characteristic of the engine of the hybrid type industrial vehicle which concerns on embodiment of this invention. It is a flowchart which shows the flow of a setting of the idling rotation speed of the hybrid type industrial vehicle which concerns on embodiment of this invention. It is a block diagram which shows the structure of the conventional hybrid forklift which concerns on the conventional embodiment.

Hereinafter, a hybrid industrial vehicle according to an embodiment of the present invention will be described with reference to FIG.
In this embodiment, an example in which the present invention is applied to a forklift is shown.
A hybrid forklift 1 shown in FIG. 1 (hereinafter simply referred to as “forklift 1”) includes an engine 2, a generator motor 3 as a cargo handling generator motor, and a cargo handling pump 4, which are connected coaxially to the generator motor 3. Is electrically connected to the battery 6 via the inverter 5. A traveling motor 7 is electrically connected to the battery 6 via an inverter 5, and a traveling device 8 is coupled to the traveling motor 7.
The engine 2, the generator motor 3, and the cargo handling pump 4 are connected coaxially, and the cargo handling pump 4 is driven by the power from the engine 2 and the generator motor 3. A cargo handling system based on such a configuration is generally called a “cargo handling parallel system”.
Further, the traveling motor 7 is driven by the power generated by the generator motor 3 and the power stored in the battery 6. A traveling system based on such a configuration is generally called a “traveling series system”.
Therefore, the forklift 1 is referred to as a “loading parallel, traveling series hybrid forklift”.

A hybrid ECU 9 (Electronic Control Unit) is electrically connected to the engine 2, the inverter 5 and the cargo handling valve 15.
Furthermore, the forklift 1 is provided with sensors such as an accelerator sensor 11 that detects the amount of depression of the accelerator pedal 10 and a cargo handling lever sensor 13 that detects the amount of operation of the cargo handling lever 12 such as a lift lever and a tilt lever. These sensors are each connected to the hybrid ECU 9.
The hybrid ECU 9 governs the entire system of the forklift 1, and a part of the control means in this device is constituted by the hybrid ECU 9.
Further, the hybrid ECU 9 is provided with a hybrid memory 14 for storing various information of the forklift 1.

The engine 2 is a diesel engine, and the fuel injection amount and the engine speed (idling speed) are controlled based on an output command value given from the hybrid ECU 9.
The generator motor 3 is driven by the engine 2 to generate power, and supplies power to the traveling motor 7 via the inverter 5 or supplies power to the battery 6 to charge the battery 6. And a function as an electric motor driven by electric power supplied from the battery 6 via the inverter 5. When the generator motor 3 operates as a generator, the engine 2 serves as a drive source for the generator motor 3 and the cargo handling pump 4, and when the generator motor 3 operates as an electric motor, the engine 2 and the generator motor 3 serve as the cargo handling pump 4. It becomes a driving source.
The cargo handling pump 4 is connected to the cargo handling valve 15 and the hydraulic oil tank 17 by a hydraulic circuit. The cargo handling valve 15 is connected to the cargo handling device 16 and the hydraulic oil tank 17 by a hydraulic circuit.
When the engine 2 and the generator motor 3 are controlled by the hybrid ECU 9, the speed of the cargo handling pump 4 is controlled, and hydraulic oil is supplied to the cargo handling device 16, and the cargo handling device 16 responds to the operation of the cargo handling lever 12. Operates with. The cargo handling device 16 includes a fork, a mast, a lift cylinder, a tilt cylinder, and the like (not shown).
The electric power generated by the generator motor 3 and the electric power stored in the battery 6 are supplied via the inverter 5 controlled by the hybrid ECU 9, whereby the electric motor 7 for driving is driven, and is composed of an axle, tires, etc. (not shown). Power is transmitted to the traveling device 8. Thereby, the forklift 1 travels at a speed corresponding to the depression amount of the accelerator pedal 10.
Further, the traveling motor 7 has a function of performing regeneration during deceleration of the forklift 1 while traveling, and the regenerated electric power is charged to the battery 6 through the inverter 5.

The battery 6 is a nickel metal hydride battery, and accumulates electric power generated by the generator motor 3 and electric power regenerated by the traveling motor 7. Then, electric power is appropriately supplied to the electric motor 7 for traveling, the generator motor 3 and the like based on the command of the hybrid ECU 9 according to the traveling of the forklift 1 and the work of cargo handling.
Further, the battery 6 is provided with a current sensor 18 for detecting the current of the battery 6, a voltage sensor 19 for detecting the voltage, and a temperature sensor 20 as temperature detecting means for detecting the temperature of the battery 6. Further, the battery 6 is provided with a battery ECU 21 for monitoring the state of the battery 6, and the battery ECU 21 is connected to the hybrid ECU 9. The battery ECU 21 together with the hybrid ECU 9 constitutes a control means in the present invention. Further, the battery ECU 21 is provided with a battery memory 22 as storage means for storing information relating to the state of the battery 6.
Information on the current sensor 18, the voltage sensor 19, and the temperature sensor 20 is sent to the battery ECU 21, and the battery ECU 21 determines the charge rate (State of Charge, generally “SOC”) of the battery 6 from the current and voltage information of the battery 6. In other words, the ratio of the remaining charge to the charge capacity of the battery is calculated. The charging rate of the battery 6 is calculated by integrating the currents that have flowed from the fully charged state of the battery 6 until that time due to discharging or charging. However, since the remaining charge amount of the nickel metal hydride battery depends on the temperature and voltage of the battery 6, the charging rate is corrected by a correction map for the temperature and voltage. Therefore, the current sensor 18, the voltage sensor 19, the temperature sensor 20, and the battery ECU 21 constitute a remaining charge detection means.

Further, the battery ECU 21 calculates the discharge allowable power of the battery 6 from the temperature and the charging rate of the battery 6.
Here, the discharge allowable power of the battery 6 will be described.
Due to its characteristics, the battery 6 is limited in the amount of power that can be discharged (discharge allowable power) when the battery temperature is low or high, or when the charging rate is low (when the remaining charge level is low). Is done. That is, the allowable discharge power is set to be smaller than the limit value L.
The limit value L is a constant value determined based on the withstand voltage of the circuit components.
This is because, for example, when the battery temperature is low, the chemical reaction rate in the battery decreases and the power that can be supplied stably decreases, and when the battery temperature is high, the deterioration of the battery is accelerated when the discharge amount increases. This is because, when the charging rate is reduced, if the discharge amount is increased, the battery is overdischarged and the deterioration of the battery may be accelerated.

For this reason, the battery memory 22 stores, for example, a map in which the temperature of the battery 6 and the discharge allowable power of the battery 6 at that temperature are set in advance as shown in FIG. Then, the battery ECU 21 calculates the discharge allowable power of the battery 6 based on the map shown in FIG.
In this embodiment, the discharge allowable power of the battery 6 is set to be smaller than the limit value L in a low temperature region of 10 degrees or less as the first temperature and a high temperature region of 50 degrees or more as the second temperature. Note that the battery temperature at which the discharge allowable power is smaller than the limit value L is an example, and the battery temperature varies depending on the type and characteristics of the battery 6.
The allowable discharge power is set to be smaller with respect to the limit value L as the temperature of the battery 6 is lower in the low temperature region. Similarly, the discharge allowable power is smaller with respect to the limit value L as the temperature of the battery 6 is higher in the high temperature region. Is set to be
On the other hand, regarding the charging rate, for example, when the charging rate becomes 20% or less of the full charge, the charging from the battery 6 is prohibited. Therefore, when the charging rate of the battery 6 decreases, the discharge allowable power becomes zero regardless of the temperature of the battery 6. Here, the value of the charging rate of the battery set so that the discharge allowable power is smaller than the limit value L is also an example.
The battery ECU 21 calculates discharge allowable power based on at least one of the map information and the charge rate information on the temperature of the battery 6 and transmits the calculated discharge allowable power to the hybrid ECU 9.
Here, the battery ECU 21 corresponds to discharge allowable power calculation means of the present invention.

Next, the operation of starting the forklift 1 during normal operation, that is, control of the forklift 1 during normal time when the discharge amount of the battery 6 is not limited will be described.
When the forklift 1 is stopped and the forklift 1 is not in operation, the engine 2 is controlled by the hybrid ECU 9 to rotate at the idling speed. The idling rotational speed at the normal time is the lowest rotational speed at which the engine rotational speed can be maintained in a state where no load is applied to the engine 2.
When the accelerator pedal 10 is depressed by the operator from the state where the forklift is stopped, the accelerator sensor 11 detects the amount of depression of the accelerator pedal 10 and transmits it to the hybrid ECU 9. The hybrid ECU 9 controls the engine 2, the generator motor 3, the travel motor 7, and the inverter 5 so that the forklift 1 travels at a speed corresponding to the depression amount of the accelerator pedal 10.
The engine 2 increases the fuel injection amount based on the output command from the hybrid ECU 9 and increases the engine speed. However, since the engine 2 increases the rotational speed from the idling rotational speed, the output of the engine 2 is small immediately after the start of traveling. Therefore, the electric power generated by the generator motor 3 driven by the engine 2 is small. Therefore, until the rotational speed of the engine 2 is sufficiently increased and the output is increased so that sufficient power is generated in the generator motor 3, the generator motor 3 generates power more than the power consumed by the traveling motor 7. The electric power is smaller and the electric power consumed by the traveling motor 7 is insufficient. Therefore, the hybrid ECU 9 controls the power shortage in the traveling motor 7 so as to supply the power stored in the battery 6, and the power is supplied from the battery 6.
As described above, the power shortaged by the traveling motor 7 is supplemented by the power stored in the battery 6 until the engine speed reaches a speed at which the generator motor 3 can generate enough power.

Next, the control at the start of cargo handling of the forklift 1 will be described.
When the handling lever 12 is operated by the operator from the state where the forklift is stopped, the handling lever sensor 13 detects the operation amount of the handling lever 12 and transmits the information to the hybrid ECU 9. The hybrid ECU 9 controls the engine 2, the generator motor 3, and the inverter 5 so that the cargo handling device 16 is operated at a cargo handling speed corresponding to the operation amount of the cargo handling lever 12.
The engine 2 increases the fuel injection amount based on the output command from the hybrid ECU 9 and increases the engine speed. However, since the engine 2 increases the rotational speed from the idling rotational speed, the torque from the engine 2 is small because the engine rotational speed is low immediately after the start of cargo handling, as shown in the torque characteristic diagram shown in FIG. Therefore, in order to operate the cargo handling device 16 at a cargo handling speed corresponding to the operation amount of the cargo handling lever 12, the torque of the engine is smaller than the torque required by the cargo handling pump 4, and the cargo handling pump 4 can be used only with the torque of the engine 2. Insufficient torque. Therefore, the hybrid ECU 9 drives the generator motor 3 as an electric motor by supplying the electric power stored in the battery 6 to the generator motor 3. Then, torque is added by the generator motor 3 so that the torque required for the cargo handling pump 4 is obtained. As a result, the generator motor 3 compensates for the insufficient torque in the engine 2 until the engine speed increases sufficiently to generate sufficient torque.
Therefore, the forklift 1 is operated at a cargo handling speed corresponding to the operation amount of the cargo handling lever 12 by operating the cargo handling lever 12 while the forklift is stopped.
As described above, the shortage of the output of the engine 2 is assisted by the electric power stored in the battery 6 at the start of traveling and at the start of cargo handling.

Next, the control of the forklift 1 when the discharge amount of the battery 6 is limited, that is, when the discharge allowable power is smaller than the limit value L will be described.
As described above, when the battery 6 is at a low temperature, at a high temperature, or when the charging rate is lowered, the discharge allowable power becomes smaller than the limit value L and the discharge amount of the battery 6 is limited.
Therefore, the assist by the electric power stored in the battery 6 at the start of traveling or the start of cargo handling work cannot be sufficiently received. That is, at the start of traveling, the power shortage in the traveling motor 7 is compensated by the power stored in the battery 6, but the supply of the power is limited. In addition, at the start of cargo handling, the generator motor 3 is driven and compensated for the torque that is insufficient to rotate the cargo handling pump 4, but the power stored in the battery 6 supplied to the generator motor 3 is supplied. Is limited.
Therefore, when the hybrid ECU 9 receives information that the discharge allowable power from the battery ECU 21 is smaller than the limit value L, the discharge amount of the battery 6 is limited, so that the idling rotation speed of the engine 2 is increased (rotation speed). Control). The idling speed of the engine 2 is increased by issuing an output command from the hybrid ECU 9, and the engine 2 is controlled by controlling the fuel injection amount.
The idling speed to be increased is set according to the temperature of the battery 6 and the charging rate. Particularly regarding the temperature of the battery 6, the value of the idling rotational speed is set in a plurality of stages according to the temperature of the battery 6.
This is because the discharge allowable power of the battery 6 depends on the temperature of the battery 6 as shown in FIG. Therefore, in the region where the discharge allowable power is set to be smaller than the limit value L, when the discharge allowable power is large (when the discharge allowable power is not limited so much), the battery 6 supplies a certain amount of power. Although it is not necessary to increase the idling speed of the engine 2 more than necessary, when the discharge allowable power is small, the power supplied from the battery 6 is reduced, and therefore it is necessary to sufficiently increase the idling speed. That is, in the region where the allowable discharge power is set to be smaller than the limit value L, the idling rotational speed of the engine 2 is set to increase as the discharge allowable power decreases.
In this embodiment, as shown in FIG. 2, the battery 6 is set so that the discharge amount of the battery 6 becomes smaller than the limit value L, and the battery 6 has a low temperature region of 10 degrees or less and a high temperature region of 50 degrees or more. The idling rotation speed is set by dividing the section from A to D according to the temperature.

The idling speed is set so as to increase as the temperature of the battery 6 increases in the high temperature region. As shown in FIG. 2, in the high temperature region, it is provided in three stages (A, B, C) depending on the temperature. The idling speed is set so that A <B <C. For example, as shown in FIG. 3, when the idling speed at the normal time is 700 rpm, the speed is set in steps of 800 rpm in the A section, 900 rpm in the B section, and 1000 rpm in the C section.
On the other hand, in the low temperature region, the idling speed is set to increase as the temperature of the battery 6 decreases. In the low temperature region, it is provided in three stages (D, E, F) depending on the temperature. The idling speed is set so that D <E <F. For example, as shown in FIG. 3, it is set in steps of 800 rpm in the D section, 900 rpm in the E section, and 1000 rpm in the F section.
In the case where the charging rate of the battery 6 is lowered, the discharging of the battery 6 is prohibited when the charging rate of the battery 6 becomes 20% or less, and the discharge allowable power of the battery 6 becomes zero. Therefore, when the charging rate of the battery 6 becomes 20% or less, regardless of the temperature of the battery 6, the idling speed of the engine 2 is increased to, for example, 1000 rpm as shown in FIG.
As described above, when the discharge allowable power is smaller than the limit value L and the discharge amount of the battery 6 is limited, the idling rotational speed is derived based on the temperature or the charging rate of the battery 6.
When the idling speed is increased, the torque of the engine 2 increases as the engine speed increases as shown in FIG. In particular, in the low speed region of the engine 2, the effect of increasing torque by increasing the engine speed is great. Since the output of the engine is represented by the product of the engine speed and the torque, the output of the engine 2 increases by increasing the idling speed.
Therefore, by increasing the idling speed, the generated power immediately after the start of traveling of the generator motor 3 driven by the engine 2 can be increased in the operation of starting the traveling of the forklift 1. On the other hand, in the operation of starting the handling, the torque immediately after the start of the handling of the engine 2 increases, and a large torque can be applied to the cargo handling pump 4.

Next, the flow of setting the idling speed by the battery ECU 21 and the hybrid ECU 9 shown in FIG. 4 will be described. This flow is performed at predetermined time intervals when the forklift is stopped.
First, the battery ECU 21 calculates the charging rate of the battery 6 and the discharge allowable power of the battery 6 from the information of the temperature sensor 20, the current sensor 18, and the voltage sensor 19 of the battery 6 (S1). The discharge allowable power is calculated based on at least one of the temperature of the battery 6 and the charging rate of the battery 6 as described above. Then, the discharge allowable power of the battery 6 is transmitted to the hybrid ECU 9.
The hybrid ECU 9 determines whether the allowable discharge power is smaller than the limit value L from the received allowable discharge power of the battery 6 (S2). When the discharge allowable power is equal to or greater than the limit value L (No in S2), the discharge amount of the battery 6 is not limited and is set to the idling speed at the normal time. Further, when the discharge allowable power of the battery 6 is smaller than the limit value L (S3 Yes), since the discharge amount of the battery 6 is limited, based on the map of the discharge allowable power at the temperature of the battery 6 and the charging rate, The idling rotational speed to be increased is derived (S4). Then, the hybrid ECU 9 sets the idling speed (S5), instructs the engine 2 regarding the idling speed, and controls the engine 2 to perform idling at the set idling speed.

According to the above embodiment, the following effects are obtained.
(1) Based on information on at least one of the temperature of the battery 6 and the charging rate of the battery 6, discharge allowable power that can be discharged by the battery 6 is calculated.
When the discharge allowable power becomes smaller than the limit value L and the discharge amount of the battery 6 is limited when the battery 6 is at a low temperature or a high temperature or when the charging rate is lowered, the hybrid ECU 9 sets the idling speed of the engine 2. Was increased from the idling speed at the normal time.
Thus, at the start of traveling, even when the supply of electric power stored in the battery 6 to the electric motor 7 for electric power is restricted, the idling rotational speed increases, so that the amount of electric power generated by the generator motor 3 is normal. Therefore, it is possible to supply the traveling electric motor 7 with a larger electric power than in the normal time. Therefore, the traveling electric motor 7 does not have a shortage of power consumption, and the traveling performance of the forklift 1 is not limited.
On the other hand, at the start of cargo handling, even if the supply of electric power stored in the battery 6 to the generator motor 3 is restricted and the torque to be supplemented from the generator motor 3 to the cargo handling pump 4 is restricted, the idling speed is increased. The torque of 2 is increasing. Therefore, the engine 2 can apply a larger torque to the cargo handling pump 4 than usual, and the cargo handling performance of the forklift 1 is not limited.
As a result, by increasing the idling speed of the engine 2, the work efficiency is not reduced by the output of the engine 2 even when the assist by the electric power stored in the battery 6 cannot be sufficiently performed.
(2) In the region where the allowable discharge power is set to be smaller than the limit value L, the hybrid ECU 9 is set so that the idling speed of the engine 2 increases as the allowable discharge power decreases.
The hybrid ECU 9 sets the idling speed of the engine 2 in accordance with the calculated discharge allowable power of the battery 6, so that the idling speed is not set higher than necessary.
As a result, an increase in fuel consumption of the engine 2 due to an increase in idling speed can be minimized.
(3) The discharge allowable power is set to be smaller than the limit value L in a low temperature region of 10 or less and a high temperature region of 50 degrees or more, for example. The lower the temperature, the higher the rotation speed, and the higher the temperature range of the battery 6, the higher the temperature of the battery 6, the higher the rotation speed.
Thereby, in the low temperature area | region of the battery 6, and the high temperature area | region of the battery 6, it can be set as the idling rotation speed which can compensate the electric power which is insufficient enough with respect to the restriction | limiting of the discharge amount of the battery 6. FIG.
(4) Even if the idling speed is increased, if the load on the engine 2 during idling is small, the fuel injection amount is small. Therefore, the increase in fuel consumption can be suppressed to the minimum.
(5) Since the engine 2 is a diesel engine, the output of the engine 2 can be immediately increased by increasing the fuel injection amount. Thereby, the discharge time of the battery 6 in the state where the discharge amount of the battery 6 is limited can be shortened, and the burden on the battery 6 can be reduced.

The above embodiment is not limited to the above, and may be modified as follows.
The forklift 1 of the above embodiment may further include seating detection means for detecting that an operator is seated on the seat. When the hybrid ECU 9 limits the discharge amount of the battery 6 and increases the idling speed, when the seating detection means detects that the operator has left the seat, the hybrid ECU 9 sets the engine speed to the idling at the normal time. Control to return to the rotation speed. As a result, when the worker leaves the seat, there is no immediate running or cargo handling work, so the fuel consumption of the engine 2 can be suppressed by returning to the normal idling speed. it can.
In the said embodiment, you may apply to the forklift 1 which has a power mode which raises acceleration performance and cargo handling performance more, and performs more powerful operation | movement. In this case, the discharge amount of the battery 6 is limited, and the idling speed may be further increased when the power mode is set while the idling speed is increasing. Thereby, even if it operates powerfully, the burden on the battery 6 can be reduced.
In the above embodiment, the idling rotational speed to be increased is described as three stages in the low temperature region and three stages in the high temperature region. However, the idling rotational speed of the engine is set higher as the battery temperature is lower. As long as the temperature of the battery is set so as to increase the idling speed of the engine, the number of stages and whether to provide the idling speed in stages are not particularly limited.
In the above embodiment, a diesel engine has been described as an example of the engine 2, but a gasoline engine may be used. In that case, the engine output is also controlled by the throttle opening.
In the said embodiment, although the nickel hydride battery was demonstrated as an example of the battery 6, if it is a battery which needs to restrict | limit the discharge amount of a battery with battery temperature and a charging rate, such as a lithium ion battery, it will not specifically limit.
In the above embodiment, the forklift 1 has been described as an example of an industrial vehicle. However, the industrial vehicle is not particularly limited as long as it is a cargo handling parallel and traveling series type industrial vehicle.

DESCRIPTION OF SYMBOLS 1 Hybrid type forklift 2 Engine 3 Generator motor 5 Battery 6 Driving motor 8 Cargo handling pump 9 Hybrid ECU
18 Current sensor 19 Voltage sensor 20 Temperature sensor 21 Battery ECU

Claims (3)

Engine,
Battery,
A cargo handling generator motor having a function as a generator connected to the engine and generating electric power by driving the engine, and a function as an electric motor driven by electric power supplied from the battery,
A cargo handling pump driven by the engine or the generator motor for cargo handling;
A traveling motor driven by power generated by the cargo handling generator motor or power from the battery;
Control means for controlling the engine, the battery, the cargo handling generator motor, and the traveling motor;
Temperature detecting means for detecting the temperature of the battery;
Remaining charge detection means for detecting the remaining charge of the battery;
Discharge allowable power calculation means for calculating discharge allowable power of the battery based on at least one information of the detected temperature of the battery and the remaining charge of the battery, and
The control means controls the cargo handling generator motor and the traveling motor based on the calculated discharge allowable power, and increases the idling speed of the engine when the discharge allowable power is smaller than a limit value. Hybrid type industrial vehicle characterized by   2. The hybrid according to claim 1, wherein the control unit controls the engine such that the idling rotational speed of the engine becomes larger as the calculated discharge allowable power becomes smaller than the limit value. Type industrial vehicle. The discharge allowable power is set to be smaller than a limit value in a low temperature region where the battery temperature is equal to or lower than the first temperature and in a high temperature region where the battery temperature is equal to or higher than the second temperature,
The control means controls the engine so that the idling speed of the engine increases as the temperature of the battery decreases in the low temperature region, and the idling rotation of the engine increases as the temperature of the battery increases in the high temperature region. The hybrid industrial vehicle according to claim 2, wherein the engine is controlled so as to increase the number.