JP6744166B2 - Electric work vehicle and its control device - Google Patents

Description

The present invention relates to an electric work vehicle including a PTO driven by an engine, a battery, an electric motor driven by the electric power of the battery, and a hydraulic pump driven by the PTO or the electric motor, and a control device therefor.

Conventionally, it is known that an electric work vehicle of this type includes a control device that switches to a PTO mode in which a hydraulic pump is driven by a PTO or an electric mode in which a hydraulic pump is driven by an electric motor.

In order to prevent the work machine from performing unexpected operation when the electric motor cannot drive the pump normally due to the battery exhaustion or electric system failure while the hydraulic pump electric motor is being driven. For example, in Patent Document 1, the control device controls the operation of the valve device so as to make an emergency stop of the work machine when the remaining amount of the battery drops below a predetermined lower limit value in the electric motor drive state.

Further, there is known an electric work vehicle such as Patent Document 2 in which the engine is automatically returned to switch to the PTO mode when the SOC decreases in the electric mode.

JP-A-2014-122100 JP, 2013-060280, A

However, in the electric work vehicle described in Patent Document 1, if the remaining amount of the battery decreases while the work machine is operating, the work machine is stopped and the work is interrupted each time, so there is a problem in workability. ..

On the other hand, in the electric work vehicle described in Patent Document 2, the work mode is automatically switched from the electric mode to the PTO mode while the work machine is operating, and thus the work is not normally interrupted.

However, when switching from the electric mode to the PTO mode, switching time is required because the PTO device is connected and disconnected and the clutch is connected and disconnected. If this switching time becomes longer than usual due to some reason such as a failure, the driving force to the hydraulic pump will be temporarily cut off. Then, while the working machine that is operating seems to be temporarily stopped by the worker, it suddenly starts to move after the switching, and the worker may not be able to cope with the unexpected movement.

The present invention has been made in view of the above points, and an object of the present invention is to allow a worker to safely and as little as possible when switching from the electric mode while the working machine is operating to the PTO mode. To be able to work.

In order to achieve the above object, in the present invention, the power supply from the battery to the electric motor is stopped when the switching time is longer than the upper limit value.

Specifically, in the first invention,
Engine,
A PTO driven by the engine,
A battery,
An electric motor driven by the power of the battery,
A hydraulic pump driven by the PTO or the electric motor,
A working machine driven by the hydraulic pump,
It is assumed that the electric work vehicle is equipped with a control device that switches the PTO mode in which the hydraulic pump is driven by the PTO or the electric mode in which the hydraulic pump is driven by the electric motor. Further, the fourth aspect of the invention is premised on the control device provided in the electric work vehicle.

An engine restart mode controlled by the control device is provided between the electric mode and the PTO mode,
In the engine restart mode, the engine is started when the charging rate of the battery is smaller than a lower limit value when the engine is stopped and the work machine is operating in the electric mode, and the PTO is changed from the electric mode. Configured to switch to mode
The control device includes a timer for measuring a switching time for switching from the electric mode to the PTO mode after starting the engine restart mode, and when the switching time measured by the timer is longer than an upper limit value, The power supply from the battery to the electric motor is stopped.

According to the above configuration, during operation of the work machine, the engine is automatically started when the state of charge (SOC) of the battery is smaller than the lower limit value, which does not bother the operator. For some reason, even if the SOC is less than the lower limit, the time it takes to switch from the electric mode to the PTO mode takes longer than the upper limit. If the working machine continues to operate, the hydraulic pump will be driven. Since the force is temporarily cut off, the working machine may stop and start suddenly, which is dangerous for the worker. On the other hand, according to the above configuration, the control device determines the length of the switching time, and if the range is not a problem, the work machine is continuously operated to eliminate the work interruption of the worker, while the range is not a problem. For example, by stopping the work machine, the safety of workers can be secured. Thereby, when switching from the electric mode to the PTO mode, the worker can perform the work safely without interrupting the work as much as possible.

In addition, in the case of an electric dust truck, even if the electric power supply to the electric motor is stopped and there is an emergency stop, unlike the aerial work vehicle, for example, only the dust loading device stops and the safety of the worker is ensured. To be done.

In a second invention, in the first invention,
The control device is
A vehicle-side control device for controlling the vehicle,
It is equipped with a bodywork side control device that controls the bodywork mounted on the vehicle,
The power supply to the electric motor from the battery is stopped by turning off the power of the mounting-side control device.

According to the above configuration, the power supply from the battery to the electric motor is reliably stopped by the simple configuration.

In the third invention, in the second invention,
The PTO switch for setting the PTO mode is a momentary switch that self-returns after being pressed regardless of the PTO mode or the electric mode.

That is, if the PTO switch is an alternate type switch as in the conventional case, the body side repeatedly stops and drives while the PTO switch is physically kept in the ON state. Therefore, when the PTO switch is automatically switched to the PTO mode. There may be a situation where the state of the PTO switch and the actual mode do not match, but according to the above configuration, the momentary switch is a so-called rebound type switch, and after operation, it returns to the state before pressing, Even if the vehicle-side control device switches the mode, there is no inconsistency with the PTO switch.

As described above, according to the present invention, after starting the engine restart mode, if the switching time for switching from the electric mode to the PTO mode is longer than the upper limit value, the power supply from the battery to the electric motor is stopped. By doing so, when switching from the electric mode to the PTO mode while the working machine is in operation, the worker can work safely without interruption as much as possible.

It is a flow chart which shows power switching control of an electric garbage truck. It is a side view showing the electric dust truck concerning the embodiment of the present invention. It is a schematic plan view of the electric dust truck according to the present invention. It is a partial block diagram of the electric dust collection vehicle which concerns on this invention.

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

FIG. 2 is a side view of an electric dust truck 1 as an electric work vehicle according to an embodiment of the present invention. The electric dust truck 1 performs a base vehicle 10 for traveling and a work for collecting dust. And a dust collecting device 20 as a bodywork.

The base vehicle 10 includes a chassis frame 11 and a cab 12 provided at a front portion of the chassis frame 11. The chassis frame 11 is provided with a pair of left and right wheels 11a at the front and a pair of left and right wheels 11b at the rear. Inside the cab 12, a driver's seat and a passenger seat are provided.

The dust collection device 20 includes a dust storage box 21 for storing dust, and a dust throwing box 22 provided behind the dust storage box 21 for loading the dust into the dust storage box 21. In the lower part of the rear surface of the dust throwing box 22, a rectangular dust throwing port 22a is provided. The dust input port 22a can be opened and closed by a door 22b.

Inside the dust throwing box 22, there is provided a dust throwing device 23 as a working machine for compressing the dust thrown through the dust throwing port 22a and pushing it toward the dust storing box 21. The dust throwing box 22 is provided with an operation switch 22c as an operating section for operating the dust loading device 23 adjacent to the dust throwing port 22a.

The dust loading device 23 includes a rotating plate 23a for scraping the dust thrown from the dust throwing port 22a to the dust storage box 21 side, and a pushing plate 23b for pushing the dust scraped by the rotating plate 23a into the dust storage box 21. And have. The rotary plate 23a is driven by a hydraulic motor 23c, and the pushing plate 23b is driven by a swing cylinder 23d.

FIG. 3 is a schematic plan view of the electric dust truck 1 according to the present embodiment. The electric dust truck 1 is mainly provided with an engine E, a transmission T provided behind the engine E, and a transmission T. A PTO (Power take off) device 24 and an electric motor 25 as an electric motor connected to the PTO device 24 by a PTO shaft 28. Further, a hydraulic pump 26 that is driven by at least one of the power of the engine E and the power of the electric motor 25 transmitted via the PTO device 24 is provided. The hydraulic pump 26 is connected to the electric motor 25. In the base vehicle 10 of this embodiment, the power of the electric motor 25 is used only by the hydraulic pump 26, and the vehicle is driven only by the power of the engine.

FIG. 4 is a partial block diagram of the electric dust truck 1 according to the present embodiment. The electric dust truck 1 is mainly provided with a vehicle body battery 13 for driving the dust loading device 23 and an inverter device 27. The electric motor 25 is driven at a predetermined rotation speed by the electric power from the inverter device 27, and accordingly, the hydraulic pump 26 connected to the electric motor 25 is driven. The high-pressure oil of the hydraulic pump 26 is supplied to the hydraulic motor 23c, the swing cylinder 23d, etc. via the accumulator 41 and the control valve 42, and these hydraulic actuators 23c, 23d are driven. The hydraulic oil is returned to the hydraulic oil tank 43, and the hydraulic oil that has passed through the suction filter 44 is supplied to the hydraulic pump 26 again. Although not shown, the electric motor 25 may be provided between the clutch C and the transmission T.

The power of the engine E is transmitted to the PTO device 24 via the clutch C and the transmission T. When the PTO device 24 is in the connected state (on state), the power transmitted to the PTO device 24 is transmitted to the hydraulic pump 26 via the PTO shaft 28 and the electric motor 25. When the power of the engine E is transmitted to the hydraulic pump 26, the electric motor 25 basically idles as the PTO shaft 28 rotates. On the other hand, during traveling in which the PTO device 24 is in the disconnected state (off state), the driving force of the transmission T is transmitted to the wheels 11b via the differential (differential gear) 40.

From the above, the hydraulic pump 26 can be driven in the following states. Specifically, the PTO mode is directly driven by the power from the engine E via the PTO device 24, the electric mode is driven by the power from the electric motor 25 mainly driven by the electric power of the battery 13, and the engine is It is possible to switch between a simultaneous mode in which power is supplied from both E and the electric motor 25. Further, an engine restart mode is provided between the electric mode and the PTO mode.

As shown in FIG. 4, the electric dust truck 1 has, as a control device, a vehicle-side control device 30 that controls the base vehicle 10 and a mounting-side control device that controls the dust collecting device 20 mounted on the vehicle. PLC (programmable logic controller) 31 of.

The vehicle-side control device 30 plays a role of controlling the entire electric system of the base vehicle 10 including engine control, air-conditioner control, and the like, and the vehicle-side control device 30 drives the hydraulic pump 26 by the PTO device 24 in the PTO mode, electric Switching control can be performed to an electric mode in which the motor 25 drives the hydraulic pump 26 or an engine restart mode.

That is, the vehicle-side control device 30 starts the engine E when the charging rate of the battery 13 is smaller than the lower limit value when the engine E is stopped and in the electric mode, and the engine restart mode in which the electric mode is switched to the PTO mode. Is configured to do.

In addition, the vehicle-side control device 30 has a timer 33 that measures the switching time for switching from the electric mode to the PTO mode after starting the engine restart mode, and the switching time measured by the timer 33 is longer than the upper limit value. In this case, the power supply from the battery 13 to the electric motor 25 is stopped. In the present embodiment, the power supply to the electric motor 25 from the battery 13 is stopped by turning off the power of the PLC 31. The power source of the PLC 31 in the present embodiment is not the battery 13 but the auxiliary battery (not shown) provided separately for driving the auxiliary device of the base vehicle 10.

The PTO switch 32 for setting the PTO mode is a momentary switch that self-returns after being pressed regardless of the PTO mode or the electric mode. The PTO switch 32 is provided in the cab 12, for example, as shown in FIG.

With the above-described configuration, the engine E is automatically started when the state of charge (SOC) of the battery 13 is smaller than the lower limit value, which does not bother the operator. For some reason, if the time taken to switch from the electric mode to the PTO mode is longer than the upper limit value even though the SOC is smaller than the lower limit value, the battery of the battery 13 may run out. In the present embodiment, the power supply to the electric motor 25 is forcibly stopped, so that the battery can be surely prevented from running out. In addition, in the case of the electric dust truck 1, even if the electric power supply to the electric motor 25 is stopped and an emergency stop is made, unlike the case where a worker rides like an aerial work vehicle, the dust loading device 23 and the like are The worker's safety is ensured because it only stops at a predictable timing.

Also, if the PTO switch 32 is a conventional alternate type switch, the body side repeatedly stops and drives while the PTO switch 32 is physically kept in the ON state, so that the PTO mode automatically switches to the PTO mode. In this case, there is a problem in that the state of the PTO switch 32 and the actual mode may not match.

However, in the present embodiment, since the PTO switch 32 is a momentary switch that is a so-called rebound type switch, it does not match the PTO switch 32 even after the operation returns to the state before pressing and the vehicle-side control device switches the mode. Does not occur.

Next, the operation of the electric dust truck according to this embodiment will be described.

As shown in FIG. 1, first, in step S01, for example, an operator operates the controller to stop the engine E, and in step S02, the electric mode is set.

Next, in step S03, the vehicle side control device 30 determines whether the charging rate (SOC) is A% or more. If A% or more, the process proceeds to step S04, power is supplied from the battery 13 to the bodywork side, and the process returns to S02 again to maintain the electric mode.

On the contrary, if the SOC is smaller than A%, the charging of the battery 13 is insufficient, so the routine proceeds to step S05. The value of A is not particularly limited and may be, for example, 10 to 30%.

In step S05, the vehicle side control device 30 automatically starts the engine E, starts the measurement by the timer, and starts the measurement of the mode switching time.

Next, in step S06, the vehicle side control device 30 switches to the PTO mode and ends the measurement of the timer, and then in step S07, determines whether the switching time is shorter than T seconds. If it is shorter than T seconds, there is no abnormality, so the process proceeds to step S08, and the drive on the body side is continued in the PTO mode. The length of the switching time used as the criterion may be shorter than T seconds or longer than T seconds.

On the contrary, if the length is T seconds or more, the vehicle-side control device 30 determines that there is some abnormality, and stops the supply of the body-side power supply in step S09. Specifically, the power supply to the PLC 31 from the battery 13 or an in-vehicle battery (not shown), a generator or the like is stopped. As a result, the driving of the rocking cylinder 23d and the hydraulic motor 23c is stopped, and the operation of the dust loading device 23 is stopped. The value of T is not particularly limited and may be, for example, 0.5 to 2 seconds.

Then, in step S10, the work of charging the battery 13 and other abnormalities are eliminated, and then in step S11, the supply of the body-side power supply is started again. Specifically, the supply of electric power from the battery 13 or the like to the PLC 31 is restarted. Next, in step S12, an input to the mounting side by the hydraulic motor 23c or the like is waited, and if there is an input, the operation of the dust loading device 23 or the like is restarted. For this reason, unlike the conventional case, the dust loading device 23 in operation does not stop and then suddenly starts moving, so that there is no problem that the operator cannot properly cope with the unexpected movement.

Therefore, according to the electric dust truck 1 according to the present embodiment, when switching from the electric mode during the operation of the dust loading device 23 to the PTO mode, the worker can perform work safely without interruption as much as possible. it can.

Note that the above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, and uses.

For example, in the above-described embodiment, the dust loading device 23 is a rotary type, but may be a so-called press type or planetary gear type.

In the above-described embodiment, the electric work vehicle is the electric dust truck, but the present invention is not limited to this, and the present invention can be applied to any electric work vehicle as long as it is a work vehicle that performs work with the hydraulic pressure generated by the hydraulic pump driven by the electric motor. ..

1 Electric garbage truck (electric work vehicle)
10 Base Vehicle 11 Chassis Frame 11a Wheel 11b Wheel 12 Cab 13 Battery 20 Dust Collection Device 21 Dust Storage Box 22 Dust Input Box 22a Dust Input Port 22b Door 22c Operation Switch 23 Dust Loading Device (Working Machine)
23a Rotating plate 23b Pushing plate 23c Hydraulic motor 23d Oscillating cylinder 24 PTO device 25 Electric motor 26 Hydraulic pump 27 Inverter device 28 PTO shaft 30 Vehicle side control device (control device)
31 PLC (body-side control device (control device))
32 PTO Switch 41 Accumulator 42 Control Valve 43 Hydraulic Oil Tank 44 Suction Filter C Clutch E Engine T Transmission

Claims (4)

Engine,
A PTO driven by the engine,
A battery,
An electric motor driven by the power of the battery,
A hydraulic pump driven by the PTO or the electric motor,
A working machine driven by the hydraulic pump,
An electric work vehicle comprising: a control device for switching to a PTO mode in which the hydraulic pump is driven by the PTO or an electric mode in which the hydraulic pump is driven by the electric motor.
An engine restart mode controlled by the controller is provided between the electric mode and the PTO mode.
In the engine restart mode, the engine is started when the charging rate of the battery is smaller than a lower limit value when the engine is stopped and the work machine is operating in the electric mode, and the PTO is changed from the electric mode. Configured to switch to mode
The control device includes a timer for measuring a switching time for switching from the electric mode to the PTO mode after starting the engine restart mode, and when the switching time measured by the timer is longer than an upper limit value, An electric work vehicle configured to stop the supply of electric power from a battery to the electric motor. The electric work vehicle according to claim 1,
The control device is
A vehicle-side control device for controlling the vehicle,
It is equipped with a bodywork side control device that controls the bodywork mounted on the vehicle,
An electric work vehicle configured to stop power supply from the battery to the electric motor by turning off the power of the bodywork side control device. The electric work vehicle according to claim 2,
The electric work vehicle, wherein the PTO switch for setting the PTO mode is a momentary switch that self-returns after being pressed regardless of the PTO mode or the electric mode. Engine,
A PTO driven by the engine,
A battery,
An electric motor driven by the power of the battery,
A hydraulic pump driven by the PTO or the electric motor,
A working machine driven by the hydraulic pump,
In a control device provided in an electric work vehicle including:
It is configured to switch to a PTO mode for driving the hydraulic pump with the PTO or an electric mode for driving the hydraulic pump with the electric motor, and to execute an engine restart mode between the electric mode and the PTO mode. Composed,
In the engine restart mode, the engine is started when the charging rate of the battery is smaller than a lower limit value when the engine is stopped and the work machine is operating in the electric mode, and the PTO is changed from the electric mode. Configured to switch to mode
After the engine restart mode is started, a timer for measuring a switching time for switching from the electric mode to the PTO mode is provided, and when the switching time measured by the timer is longer than an upper limit value, the battery is switched to the electric motor. The control device is configured to stop the power supply of.