JP2013244933A - Working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working vehicle having a power storage device regeneratively charged using regenerated energy during vehicle traveling, and capable of suppressing as much as possible generation of exhaust gas during working, and suppressing a situation where a working device cannot be driven due to a decrease in voltage of the power storage device at a work site.SOLUTION: A working vehicle includes: a monitor device 7 for monitoring voltage of a capacitor 2; and a control part 12 which has a regular charging mode for charging the capacitor 2 by using driving energy of a vehicle traveling engine 5, and a regenerative charging mode for charging the capacitor 2 by using regenerated energy during vehicle traveling, switches over to the regular charging mode when a voltage of the capacitor 2 monitored by the monitor device 7 is decreased to or below a predetermined voltage L higher than a minimum voltage allowing an electric motor 4 to be operated, and switches over to the regenerative charging mode when the voltage of the capacitor is increased to or above a predetermined voltage H lower than a fully charged voltage.

Description

  The present invention relates to a work vehicle that regeneratively charges an electric storage device using regenerative energy while the vehicle is traveling, and uses the electric power stored in the electric storage device as power for a working device.

  Conventionally, in various hybrid vehicles such as a battery forklift, a hybrid power shovel, an electric aerial work vehicle, a hybrid crane, and a railway vehicle, an electric system using a power storage device has been widely used. For example, in Patent Document 1, electrical energy generated by electric braking is regenerated in a power storage device, the regenerated electrical energy is converted into multiphase alternating current, and a three-phase alternating current machine is driven to accelerate the vehicle. It is described that a hybrid vehicle used for auxiliary acceleration at the time is applied to a garbage truck or other work vehicle, and a prototype test is being conducted. In this type of work vehicle, a separate electric motor is provided as a work device drive source, and the electric energy regenerated is supplied to the electric motor from the power storage device. In the garbage truck described in the embodiment of Patent Document 1, the vehicle traveling engine can be stopped at the work site to drive the work device. Therefore, generation of exhaust gas during work can be prevented as compared with the case where the work apparatus is driven by a conventional PTO (Power Take Off).

JP-A-7-75208

  However, in the garbage truck as in Patent Document 1 that regeneratively charges the power storage device using the regenerative energy of the vehicle during deceleration while traveling, the distance between work sites is short and sufficient deceleration time cannot be obtained. If the amount of charge of the power storage device is insufficient for a reason, the voltage of the power storage device may be abnormally lowered and the work device cannot be driven. In such a case, if the external power source cannot be used, the power storage device can be forcibly charged by driving the generator by the vehicle traveling engine at the work site. However, work cannot be performed until the power storage device is charged to some extent.

  In addition, even when the power storage device is fully charged, if the vehicle traveling engine is stopped at the work site and the work device is continuously driven for a long time only by the power of the power storage device, the power is stored until the work device cannot be driven. The voltage of the device may drop.

  Therefore, in the present invention, in a work vehicle that regeneratively charges the power storage device using regenerative energy while the vehicle is running, the generation of exhaust gas during work is suppressed as much as possible, and the work is performed by reducing the voltage of the power storage device at the work site. An object of the present invention is to provide a work vehicle that can suppress a situation in which the device cannot be driven.

  The work vehicle according to the present invention includes a work device and an electric drive device that drives the work device, and is a work vehicle that drives the electric drive device with electric power stored in the power storage device, and monitors the voltage of the power storage device. And a regenerative charging mode in which the power storage device is charged using regenerative energy while the vehicle is running, and is monitored by a monitor device. When the voltage of the power storage device to be reduced falls below a predetermined voltage higher than the lowest voltage at which the electric drive device can be operated, it switches to the constant charge mode, and when it rises above a predetermined voltage lower than the fully charged voltage, regenerative charging And a control unit for switching to the mode.

  In the work vehicle of the present invention, charging of the power storage device that stores electric power for driving the electric drive device is normally performed in a regenerative charging mode in which the power storage device is charged using regenerative energy while the vehicle is running. When the voltage of the battery drops below a predetermined voltage higher than the minimum voltage at which the electric drive device can be operated, the power storage device is charged using the drive energy of the vehicle travel engine by switching to the constant charge mode. When the voltage rises above a predetermined voltage lower than the voltage, the mode is switched to the regenerative charging mode, so even if the charging amount of the power storage device is insufficient only by charging using regenerative energy while the vehicle is running, electric drive It is possible to prevent the voltage of the power storage device that drives the device from being abnormally reduced.

Further, even when the work device is continuously driven for a long time only by the power of the power storage device, it is possible to prevent the voltage of the power storage device from being lowered until the work device cannot be driven.
Also, since the voltage of the power storage device automatically switches to the constant charging mode only when the voltage drops below a predetermined voltage higher than the lowest voltage that can operate the electric drive device, at the work site, until it switches to the constant charging mode, The work device can be driven while the vehicle travel engine is stopped. Thereby, generation | occurrence | production of the exhaust gas during work can be suppressed as much as possible compared with the case where a working device is driven by PTO.

  Here, the work vehicle of the present invention has an idling stop device that stops the vehicle running engine in conjunction with an on signal of the parking brake, and the control unit operates the idling stop device during the regenerative charging mode to constantly charge the vehicle. It is desirable that the idling stop device is not operated during the mode.

  As a result, even if the work vehicle has an idling stop device that stops the vehicle running engine in conjunction with the on signal of the parking brake, the idling stop device is not operated during the above-described constant charging mode. The charging of the power storage device can be continued when the voltage is equal to or lower than a predetermined voltage higher than the lowest voltage at which the electric drive device can be operated. On the other hand, since the idling stop device is operated during the regenerative charge mode, it is possible to stop the vehicle travel engine and suppress the generation of exhaust gas when the voltage is higher than a predetermined voltage lower than the fully charged voltage.

  In addition, the work vehicle of the present invention has a generator driven by a vehicle travel engine, and the control unit charges the power storage device with the output of the generator when the accelerator of the vehicle travel engine is off during the regenerative charge mode. In the constant charge mode, it is desirable that the power storage device is charged by the output of the generator regardless of whether the accelerator is on or off.

  Thus, during the regenerative charging mode, the load on the generator is not applied to the vehicle travel engine when the accelerator is on (acceleration), and the influence on vehicle travel can be reduced. On the other hand, during the constant charge mode, the voltage of the power storage device has dropped below a predetermined voltage that is higher than the lowest voltage at which the electric drive device can be operated, so that the power storage device is charged by the output of the generator regardless of whether the accelerator is on or off. Thus, the power storage device can be quickly fully charged.

(1) A monitor device that monitors the voltage of the power storage device, a constant charge mode that charges the power storage device using driving energy of the vehicle travel engine, and a regeneration that charges the power storage device using regenerative energy while the vehicle is traveling When the voltage of the power storage device that has a charge mode and is monitored by the monitor device falls below a predetermined voltage that is higher than the lowest voltage at which the electric drive device can be operated, the mode is switched to the constant charge mode and is lower than the full charge voltage. According to the work vehicle including the control unit that switches to the regenerative charge mode when the voltage rises above a predetermined voltage, the charge amount of the power storage device is insufficient only by charging using regenerative energy while the vehicle is running. However, it is possible to prevent the voltage of the power storage device that drives the electric drive device from being abnormally reduced. Thereby, it is possible to suppress a situation in which the work device cannot be driven due to a voltage drop of the power storage device at the work site. Further, at the work site, the work device can be driven for a relatively long time while the vehicle running engine is stopped until the operation mode is switched to the constant charge mode. Thereby, generation | occurrence | production of the exhaust gas during work can be suppressed as much as possible compared with the case where a working device is driven by PTO.

(2) It has an idling stop device that stops the vehicle running engine in conjunction with the on signal of the parking brake, and the control unit operates the idling stop device during the regenerative charging mode, and the idling stop device during the constant charging mode. By not operating the power storage device, it is possible to continue charging the power storage device when the voltage of the power storage device is equal to or lower than a predetermined voltage higher than the lowest voltage at which the electric drive device can be operated, and to fully charge the power storage device. Become. Moreover, since the idling stop device is operated during the regeneration mode, generation of exhaust gas during work can be suppressed.

(3) It has a generator driven by the vehicle traveling engine, and the control unit charges the power storage device by the output of the generator when the accelerator of the vehicle traveling engine is off during the regenerative charging mode, and during the constant charging mode Regardless of whether the accelerator is on or off, since the power storage device is charged by the output of the generator, when the voltage of the power storage device is lower than a predetermined voltage higher than the lowest voltage at which the electric drive device can be operated, the accelerator is turned on / off. Regardless, it is possible to continue charging of the power storage device by the output of the generator and to quickly charge the power storage device fully.

It is a schematic diagram of the electric system for a working device drive with which a garbage truck in an embodiment of the invention is provided. It is a principal part enlarged view which shows the operation part of the garbage truck of FIG. It is a flowchart which shows the process of the control part at the time of selecting "regenerative charge" with a charge selection switch. It is a figure which shows a time chart at the time of selecting "regenerative charge" with a charge selection switch. It is a figure which shows a time chart at the time of selecting "always charge" with a charge selection switch.

  FIG. 1 is a schematic diagram of an electric system for driving a work device provided in a garbage truck as a work vehicle according to an embodiment of the present invention. A garbage truck as a work vehicle in the present embodiment includes an electric system 1 shown in FIG. The electric system 1 includes a capacitor 2 as a power storage device that stores electric power, an inverter device 3 that adjusts electric power from the capacitor 2, and an electric motor as an electric drive device that is driven by electric power adjusted by the inverter device 3. 4 is provided. The capacitor 2 and the inverter device 3 are electrically connected by a single electric path a. “One electric path” indicates a path through which electric power is supplied from one type of power supply without making another detour.

  Although the details of the garbage truck in this embodiment are not shown, a dust container box provided at the rear of the cab and a dust container box provided at the rear of the dust container box, as in a normal garbage truck, It has. In the dust input box, a dust collecting device 20 is mounted as a working device composed of a dust pushing plate, a rotating plate, a discharge plate and the like for loading the dust put in the dust input box into the dust containing box. Yes.

  The dust collecting device 20 includes a hydraulic pump 21 driven by the electric motor 4, a hydraulic cylinder 22 driven by the hydraulic pressure generated by the hydraulic pump 21, and a hydraulic motor 23. The hydraulic pump 21 is connected to the rotating shaft of the electric motor 4. The hydraulic pump 21 is a variable discharge pump, for example, and is normally driven by the electric motor 4 at, for example, 1500 to 1800 rpm, so that the discharge amount can be changed. The discharge amount is automatically adjusted according to the load by a hydraulic mechanism (not shown).

  The capacitor 2 is an electric double layer capacitor (so-called capacitor), and utilizes a physical phenomenon that does not use a chemical reaction and simply stores electric charges unlike a battery. Since the electric double layer capacitor has a very long life and can be charged with a large current, the charging time is very short and it is relatively inexpensive. The capacitor 2 of the present embodiment is composed of a plurality of units, and is disposed in an equipment storage box provided between the cab and the dust storage box and on the side (not shown) of the chassis, and is electrically connected. Are connected in series. Thereby, voltage output of several hundred volts is possible in total.

  The capacitor 2 is electrically connected to a DC power generation device 6 that is provided inside the vehicle and generates electric power using a vehicle travel engine 5 as a vehicle travel drive source through a single power transmission path b for charging. Can be charged.

  The DC power generator 6 includes a generator 6a that is installed separately from a small power generator (dynamo) that is normally mounted on a vehicle. The generator 6a is driven by its fan belt (not shown) while the vehicle travel engine 5 is being driven.

  Further, the DC power generator 6 includes an AVR (automatic voltage controller) 6b on the charging power transmission path b. The AVR 6b starts to operate in response to an activation signal supplied from the control unit 12 described later, and converts AC power of the generator 6a into DC. Further, the AVR 6b controls the operation and stop of the generator 6a, and makes the generator 6a idle so as not to apply a load to the vehicle travel engine 5 at the time of stop. The AVR 6b adjusts the output voltage of the generator 6a so that the target value is constant regardless of the change in the rotational speed of the vehicle travel engine 5. That is, a voltage exceeding a predetermined voltage is not supplied to the capacitor 2 by the voltage upper limit control function of the DC power generator 6 (AVR 6b).

  A permanent magnet synchronous electric motor is adopted as the electric motor 4. This permanent magnet synchronous electric drive device has a feature that the electric energy stored in the capacitor 2 can be efficiently used by performing vector control drive.

  The electric system 1 in the present embodiment further includes a monitor device 7 mounted on the vehicle, a parking brake sensor 8 that detects the parking brake on the vehicle, an accelerator off sensor 9 that detects the accelerator off of the vehicle, and the traveling of the vehicle A vehicle speed sensor 10 for monitoring the speed, an idling stop device 11, and a control unit 12 are provided. The monitor device 7 includes a temperature sensor, a voltage sensor, and the like, and monitors the temperature (cell temperature), voltage (cell voltage), and the like of the capacitor 2. Power for operation is supplied to the control unit 12 from the vehicle battery 13.

  The control unit 12 controls the inverter device 3, the AVR 6b, the idling stop device 11, and the like based on input signals from the monitor device 7, the parking brake sensor 8, the accelerator off sensor 9, the vehicle speed sensor 10, and the like. Further, the control unit 12 controls the movement of the hydraulic motor 23 and the hydraulic cylinder 22 of the dust collecting device 20. Specifically, rotation control of the hydraulic motor 23 and expansion / contraction of the hydraulic cylinder 22 are performed by switching the operation of the electromagnetic valve 24 provided in the dust collecting device 20. The control unit 12 and the electromagnetic valve 24 are electrically connected through an electric path c.

  Further, the signal from the monitor device 7 is input to the control unit 12 as described above, and is provided in or near the capacitor 2. The monitoring device 7 may also monitor other elements such as current. The control unit 12 is input with an operation signal from the operation unit 14 provided in the cab of the garbage truck or the operation unit provided in the garbage throwing box.

  FIG. 2 is an enlarged view of a main part of the operation unit 14. As shown in FIG. 2, the operation unit 14 is provided with a main switch 14a in place of a PTO switch of a garbage truck equipped with a conventional PTO (power take-off device). In the garbage truck that drives the dust collecting device 20 with the electric power from the capacitor 2, the PTO switch is not provided. On the other hand, when the operation unit provided in the dust container box is operated, the garbage traveling engine 5 is not activated. The collecting device 20 can be moved. Therefore, in order to prevent the dust collecting apparatus 20 from moving other than during work due to mischief or the like, in the present embodiment, the main switch 14a is provided in the locked driver's cab, and the main switch 14a is turned on for the first time. The dust collecting device 20 can be moved.

  In addition, the operation unit 14 is provided with a plurality of charging status display lamps 14 b that indicate the charging state of the capacitor 2. These charging status display lamps 14b indicate charging states such as “requires charging”, “usable”, and “full charge”, for example. In addition, the operation unit 14 is provided with a charge selection switch 14c for selecting “regenerative charge” and “always charge”, and an operation switch 14d such as a loading / discharging switch and a dust box opening / closing switch.

  In the garbage truck having the above-described configuration, the DC power from the charged capacitor 2 is sent to the inverter device 3 to drive the electric motor 4 and the hydraulic pump 21 at the time of garbage collection work on site. Thus, the work can be performed while the vehicle traveling engine 5 is stopped. Therefore, noise is reduced and no exhaust gas is discharged during operation, compared with a garbage truck using a PTO.

  Next, the processing of the control unit 12 when “regenerative charging” is selected by the charge selection switch 14c will be described based on the flowchart of FIG.

  Normally, the control unit 12 is in a regenerative charging mode in which the capacitor 2 is charged using regenerative energy during vehicle travel (step S101). In the regenerative charging mode, when the accelerator off sensor 9 detects the accelerator off while the vehicle is running, the control unit 12 supplies the regenerative power generated in the generator 6a to the capacitor 2 through the AVR 6b and charges it. Note that the case where the accelerator is turned off by the accelerator off sensor 9 includes not only the case where the vehicle is decelerated by applying a brake, but also the case where the vehicle is driven at a constant speed due to inertia.

  Moreover, in this regenerative charge mode, the control part 12 performs the idling stop of the vehicle travel engine 5 by the idling stop apparatus 11 (step S102). The idling stop is performed when the parking brake sensor 8 detects that the parking brake is turned on, and the idling stop device 11 stops the vehicle travel engine 5 in conjunction with the parking brake on signal from the parking brake sensor 8.

  Next, the control unit 12 monitors whether or not the voltage of the capacitor 2 is equal to or lower than a predetermined voltage (hereinafter referred to as “always charge switching value”) L higher than the lowest voltage at which the dust collecting device 20 can be operated. Monitoring is performed by the device 7 (step S103), and when it is equal to or less than the constant charge switching value L, the driving energy of the vehicle travel engine 5 is used to switch to the constant charge mode in which the capacitor 2 is charged (step S104). In the constant charge mode, the control unit 12 supplies the electric power generated when the generator 6a is driven by the vehicle traveling engine 5 to the capacitor 2 through the AVR 6b, regardless of the detection result of the accelerator off sensor 9, and charges the capacitor 2. Moreover, in this constant charge mode, the control part 12 cancels the idling stop of the vehicle travel engine 5 by the idling stop apparatus 11 (step S105). Then, the controller 12 monitors whether or not the voltage of the capacitor 2 is equal to or higher than a predetermined voltage (hereinafter referred to as “regenerative charge switching value”) H lower than the fully charged voltage by the monitor device 7 (Step S12). S106) If the value is greater than or equal to the regenerative charge switching value H, the mode is switched to the regenerative charge mode described above (step S101).

  Next, specific processing of the control unit 12 will be described in more detail with reference to the time charts of FIGS. 4 and 5. FIG. 4 is a diagram showing a time chart when “regenerative charging” is selected by the charge selection switch 14c, and FIG. 5 is a diagram showing a time chart when “always charging” is selected by the charge selection switch 14c.

  When “regenerative charging” is selected by the charge selection switch 14c, as shown in FIG. 4, the dust collecting device 20 is operating in the idling stop state between a and b. It decreases linearly as the amount of electricity stored decreases. In this section, the voltage of the capacitor 2 is constantly maintained at the charge switching value L or more from the start to the stop of the dust collecting device 20, and the control unit 12 is in the regenerative charge mode.

  Next, when the parking brake is released at the point c, the idling stop is turned off and the vehicle travel engine 5 is driven. Then, the accelerator is turned on, and the vehicle is accelerating during ef. At this time, the regenerative charging mode is continuing as described above, and the accelerator off sensor 9 does not detect the accelerator off, so that the capacitor 2 is not charged.

  The next f-g is a section in which the accelerator is turned off and the vehicle is traveling at a constant speed while the vehicle is traveling. At this time, since the accelerator off is detected by the accelerator off sensor 9, the electric power generated in the generator 6a by driving the vehicle traveling engine 5 is supplied to the capacitor 2 through the AVR 6b and charged. Between the next gh is a section where the accelerator is off and the vehicle is decelerating. Similarly, since the accelerator off sensor 9 detects the accelerator off, the regenerative power generated in the generator 6a is supplied to the capacitor 2 through the AVR 6b. Will be charged.

  Next, when the vehicle stops at point h, charging of the capacitor 2 is also stopped. The parking brake is turned on at point i, and the idling stop is also turned on.

  The next j−k is a section in which the dust collecting device 20 is operated in the idling stop state. In this section, the voltage of the capacitor 2 decreases linearly with a decrease in the charged amount of the capacitor 2. At the point k, the voltage of the capacitor 2 becomes equal to or less than the constant charge switching value L during the operation of the dust collecting device 20, and the control unit 12 switches from the regenerative charge mode to the constant charge mode.

  The next kl is a section in which the dust collecting device 20 is operated even after switching to the regular charging mode. In this section, the control unit 12 cancels the idling stop of the vehicle travel engine 5 by the idling stop device 11 and forcibly starts the vehicle travel engine 5 at the same time as switching to the constant charge mode. As a result, the generator 6a is driven by the vehicle travel engine 5, and the capacitor 2 is charged. In this embodiment, since the power consumption of the dust collecting device 20 is larger than the power generated by the generator 6a, the amount of electricity stored in the capacitor 2 is gradually reduced, and the voltage of the capacitor 2 is also correspondingly reduced. It's down.

  The next l-n is a section in which the dust collecting device 20 is stopped in the constant charging mode and the capacitor 2 is charged while the vehicle traveling engine 5 is idling. Then, the accelerator is turned on at the point n, and the vehicle is accelerating during the period n-o. Unlike the above-described period ef, the charging of the capacitor 2 is not performed because the vehicle is always in the charging mode. Has been done. Note that in this section, the amount of charge per unit time is larger than that between ln because the rotational speed of the vehicle travel engine 5 is higher than in the idling state.

  When the voltage of the capacitor 2 becomes equal to or higher than the regenerative charge switching value H at the point o, the control unit 12 switches from the constant charge mode to the regenerative charge mode. At this time, since the accelerator is on, charging of the capacitor 2 is stopped between op.

  On the other hand, when “always charging” is selected by the charge selection switch 14c, the idling stop is off regardless of whether the parking brake is on or off, and the vehicle travel engine 5 is driven. Therefore, as shown in FIG. 5, the capacitor 2 is charged during the operation of the dust collecting device 20 between a ′ and b ′. In this embodiment, since the electric power consumption of the electric motor 4 is larger than the electric power generated by the generator 6a, the amount of electricity stored in the capacitor 2 is gradually reduced, and the voltage of the capacitor 2 is also lowered accordingly. ing.

  The next b'-c 'is a section in which the dust collecting device 20 is stopped and the vehicle traveling engine 5 is charging the capacitor 2 in the idling state. Hereinafter, when “always charging” is selected by the charging selection switch 14c, the charging of the capacitor 2 is continued.

  In the present embodiment, the function of the DC power generation device 6 is not turned off with the capacitor 2 being fully charged as a trigger regardless of the above-described constant charge mode and regenerative charge mode. The reason why no problem occurs even if the capacitor 2 continues to be charged after full charge is that the voltage upper limit control function of the DC power generator 6 (AVR 6b) described above works. That is, by matching the rated output voltage of the DC power generator 6 (AVR 6b) with a desired full charge voltage of the capacitor 6, the capacitor 2 is in an equilibrium state when it is fully charged. It is possible to prevent the voltage from rising above the voltage.

The above processing is summarized as follows.
(A) Capacitor 2 charging timing <in regenerative charging mode>
Charging capacitor 2 is
(1) The vehicle speed sensor 10 is on (2) the accelerator off sensor 9 is on (3) and the parking brake sensor 8 is off.
That is, during acceleration of the vehicle, the capacitor 2 is not charged in order to reduce the load on the vehicle travel engine 5 as much as possible. On the other hand, when the vehicle is traveling at a constant speed due to inertia, the capacitor 2 is charged. Since the load by the generator 6a for charging the capacitor 2 is not so large as compared with the driving force of the vehicle travel engine 5, charging during this constant speed travel is possible. Further, since regenerative power is generated in the generator 6a during deceleration of the vehicle, the regenerative power is charged in the capacitor 2. Further, while the vehicle is stopped, the capacitor 2 is not charged even if the vehicle travel engine 5 is driven in an idling state.
<In the constant charging mode>
Charging of the capacitor 2 is always performed while the vehicle traveling engine 5 is driven and the generator 6a is operating.

(B) Idling stop timing <In regenerative charging mode>
For example, the idling stop is executed and canceled as follows.
・ Idle stop execution Parking brake on ・ Idling stop release Parking brake off <In case of constant charge mode>
Stop the idling stop function. That is, idling stop is not executed even when the vehicle stops.

(C) Switching timing between regenerative charge mode and constant charge mode The voltage of the capacitor 2 has a lower limit value and an upper limit value. The lower limit value is a voltage at which the electric motor 4 for driving the dust collecting device 20 does not operate (voltage at which the motor driver of the inverter device 3 does not operate). The upper limit value is a voltage at which the capacitor 2 is fully charged. A regenerative charge switching value H and a constant charge switching value L are set between the upper limit value and the lower limit value.

  When the voltage of the capacitor 2 is the upper limit value (full charge), the regenerative charge mode is set. When the dust collecting device 20 is driven from a state in which the voltage of the capacitor 2 is the upper limit value (full charge), the voltage of the capacitor 2 linearly decreases as the amount of stored electricity decreases. When the voltage of the capacitor 2 falls below the constant charge switching value L, the regenerative charge mode is switched to the constant charge mode. In addition, when the capacitor 2 is charged in the constantly charging mode and the voltage of the capacitor 2 exceeds the regenerative charging switching value H, the constantly charging mode is switched to the regenerative charging mode.

  As described above, in the garbage truck according to the present embodiment, charging of the capacitor 2 that accumulates electric power for driving the electric motor 4 is normally performed in the regenerative charging mode in which charging is performed using regenerative energy while the vehicle is running. When the voltage of the capacitor 2 falls below a predetermined voltage L higher than the lowest voltage at which the electric motor 4 can be operated, the capacitor 2 is charged using the driving energy of the vehicle travel engine 5 by switching to the constant charging mode. When the voltage rises above a predetermined voltage H lower than the fully charged voltage, the mode is switched to the regenerative charging mode. Therefore, even if the charging amount of the capacitor 2 is insufficient only by charging using regenerative energy while the vehicle is running, the voltage of the capacitor 2 that drives the electric motor 4 is prevented from abnormally decreasing. The charge amount of the capacitor 2 can be quickly fully charged, and when the vehicle is stopped, the capacitor 2 is fully charged. Therefore, the operation of stopping the vehicle travel engine 5 is relatively long. It becomes possible to do time.

  Moreover, the garbage truck in this embodiment has the idling stop apparatus 11 which stops the vehicle travel engine 5 in response to the on signal of the parking brake, and the control unit 12 operates the idling stop apparatus 11 during the regenerative charging mode. Since the idling stop device 11 is not operated during the constant charging mode, the charging of the capacitor 2 is continued when the voltage of the capacitor 2 is equal to or lower than a predetermined voltage L higher than the lowest voltage at which the electric motor 4 can be operated. be able to. On the other hand, in order to operate the idling stop device 11 during the regenerative charging mode, the vehicle traveling engine 5 is stopped when the voltage is higher than a predetermined voltage H lower than the fully charged voltage to reduce the generation of exhaust gas during work. Can do.

  Moreover, the garbage truck in this embodiment has the generator 6a driven by the vehicle travel engine 5, and the control part 12 is the output of the generator 6a when the accelerator of the vehicle travel engine 5 is OFF during the regenerative charge mode. Since the capacitor 2 is charged by the power supply and the capacitor 2 is charged by the output of the generator 6a regardless of whether the accelerator is on or off during the constant charging mode, the load on the generator 6a is not charged when the accelerator is on during the regenerative charging mode. It is possible not to be applied to the vehicle travel engine 5 and to reduce the influence on the vehicle travel. On the other hand, during the constant charge mode, the voltage of the capacitor 2 drops below a predetermined voltage L higher than the lowest voltage at which the electric motor 4 can be operated. Therefore, regardless of whether the accelerator is on or off, the output of the generator 6a By charging 2, the capacitor 2 can be quickly fully charged.

(Other embodiments)
In the present embodiment, the electric double layer capacitor 2 is used as the power storage device, but the present invention is not limited to this, and various power storage devices may be used. For example, it is also preferable to use a battery such as a lithium ion capacitor or a nickel metal hydride battery as the power storage device. Further, the power storage device is not limited to a dedicated work device, and may be used as a common power source for the hybrid vehicle.
In the present embodiment, the idling stop device 11 is provided. However, the present invention is not limited to this, and the present invention can also be applied to a vehicle that does not include the idling stop device.
In the present embodiment, the electric power consumption of the electric motor 4 is larger than the electric power generated by the generator 6a. However, the present invention is not limited to this, and the power generation of the generator is higher than the electric power consumption of the electric motor. It is also preferable that the force is greater.
Moreover, in this embodiment, although it comprised so that the function of the direct-current generator 6 triggered by the capacitor 2 being fully charged might not be turned off, this invention is not limited to this. For example, the voltage of the power storage device may be monitored by a monitor device, and when the fully charged voltage is reached, an output stop signal may be sent from the control unit to the DC power generator to stop the operation of the DC power generator. In this case, more reliable voltage control of the power storage device is possible.

  The work vehicle according to the present invention is useful as a vehicle that regeneratively charges a power storage device using regenerative energy while the vehicle is running, and uses the electric power stored in the power storage device as power for the work device.

DESCRIPTION OF SYMBOLS 1 Electric system 2 Capacitor 3 Inverter apparatus 4 Electric motor 5 Vehicle traveling engine 6 DC power generator 6a Generator 6b AVR
DESCRIPTION OF SYMBOLS 7 Monitor apparatus 8 Parking brake sensor 9 Accelerator off sensor 10 Vehicle speed sensor 11 Idling stop apparatus 12 Control part 13 Vehicle battery 14 Operation part 14a Main switch 14b Charging status display lamp 14c Charge selection switch 14d Operation switch 20 Dust collection apparatus 21 Hydraulic pump 22 Hydraulic cylinder 23 Hydraulic motor 24 Solenoid valve

Claims (3)

A work vehicle that includes a work device and an electric drive device that drives the work device, and that drives the electric drive device with electric power stored in a power storage device;
A monitoring device for monitoring the voltage of the power storage device;
Monitored by the monitor device having a constant charge mode for charging the power storage device using driving energy of a vehicle travel engine and a regenerative charge mode for charging the power storage device using regenerative energy during vehicle travel When the voltage of the power storage device drops below a predetermined voltage higher than the lowest voltage at which the electric drive device can be operated, switches to the constant charge mode, and rises above a predetermined voltage lower than the fully charged voltage And a control unit that switches to the regenerative charging mode. An idling stop device for stopping the vehicle travel engine in conjunction with an on signal of a parking brake;
The work vehicle according to claim 1, wherein the control unit operates the idling stop device during the regenerative charging mode and does not operate the idling stop device during the constant charging mode. Having a generator driven by the vehicle travel engine;
The control unit charges the power storage device with an output of the generator when the accelerator of the vehicle travel engine is off during the regenerative charge mode, and the power generation regardless of whether the accelerator is on or off during the constant charge mode. The work vehicle according to claim 1 or 2, wherein the power storage device is charged by an output of a machine.

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