JP2002128495A - Electric power unit controller for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maximize battery usable time and to provide positive operation even during concurrent operation of a plurality of hydraulic actuators. SOLUTION: A vehicle for high lift work has a high lift work device operated by the hydraulic actuators, and operating device 20 operated by a workman, and a control valve 36 controlling feeding of hydraulic pressure to the hydraulic actuators by receiving a manipulate signal outputted in accordance with operations of the operating device. An electric power unit 30 is composed of a hydraulic pump 31 generating the hydraulic pressure fed to the hydraulic actuator via the control valve 36 and an electric motor 32 driving the hydraulic pump 31. Drive of the electric motor 32 is controlled in accordance with the manipulate signal so as to provide an oil amount necessary for the hydraulic actuators to operate the high lift work device in accordance with the manipulate signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working vehicle having a working device operated by a hydraulic actuator, and more particularly, to a working vehicle which supplies operating hydraulic pressure to a hydraulic actuator from an electric power unit including an electric motor and a hydraulic pump. The present invention relates to a work vehicle configured to cause an operation of a device.

[0002]

2. Description of the Related Art As a working vehicle having a working device operated by a hydraulic actuator as described above, for example,
There is an aerial work vehicle. An aerial work vehicle, for example, is equipped with a swivel on the body of a truck vehicle so that it can turn freely, and attaches a boom to the turntable so that it can be raised and lowered and telescopically attached, and attaches a work platform for worker boarding to the tip of the boom. Be composed. In the aerial work vehicle having such a configuration, the turning of the swivel base, the raising and lowering of the boom, and the expansion and contraction operations are generally performed by a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder. Supply of the working oil pressure to these hydraulic actuators is performed by a hydraulic pump.

[0003] In an aerial work vehicle, a hydraulic pump is driven by an engine mounted on the work vehicle or by an electric motor. As for the driving by the engine, the power of the engine used for running the vehicle in the truck vehicle constituting the aerial work vehicle is defined as PTO (Powe
r Take-Off) to drive the hydraulic pump by taking it out through the mechanism, or to drive the hydraulic pump by mounting a hydraulic pump driving engine separate from the traveling engine on the vehicle body (that is, the engine drive power unit) Is known). On the other hand, in the case of driving by an electric motor, an electric power unit is constituted by an electric motor driven by receiving power supply from a battery disposed on a vehicle body and a hydraulic pump driven by the electric motor. A device that uses a power unit to supply hydraulic pressure from a hydraulic pump is generally used.

[0004]

However, when an electric power unit is used, there is a problem that the usable time of a battery for supplying drive power to the electric motor is short. In particular, the electric power unit is configured to always drive a hydraulic pump by an electric motor to consume a certain amount of power, regardless of the operation amount and speed of the hydraulic actuator, when working by operating the hydraulic actuator. However, there has been a problem that the usable time of the battery tends to be short. Furthermore, there is a case where a plurality of hydraulic actuators are simultaneously operated to supply a hydraulic pressure higher than the maximum output of the electric motor. In such a case, the electric motor is in an insufficient output state and the hydraulic actuator does not operate. There was a problem that there is.

The present invention has been made in view of such a problem.
It is an object of the present invention to provide an electric power unit control device having a configuration in which the battery usable time can be made as long as possible. The present invention also provides an electric power unit control device configured to prevent occurrence of a situation in which power is insufficient and a hydraulic actuator does not operate even when a plurality of hydraulic actuators are simultaneously operated. With the goal.

[0006]

In order to achieve the above object, according to the present invention, there is provided a working device mounted on a vehicle and operated by a hydraulic actuator, and an operator for controlling the operation of the working device. An operating device to be operated;
A work valve having a control valve for receiving supply of an operation signal output in response to the operation of the operation device and controlling supply of a working oil pressure to the hydraulic actuator, is supplied to the hydraulic actuator via the control valve. An electric power unit is composed of a hydraulic pump for producing an operating hydraulic pressure and an electric motor for driving the hydraulic pump. Then, the electric power unit control device controls the drive of the electric motor in response to the operation signal so that the amount of oil required for the hydraulic actuator to perform the operation of the working device in accordance with the operation signal is obtained. Be composed.

With the electric power unit control device having the above configuration, when an operation signal is output from the operation device in response to the operation of the operation device, the oil required by the hydraulic actuator to perform the operation according to the operation signal is obtained. Drive control of the electric motor is performed to supply the quantity. In other words, the electric motor is driven to supply only the amount of oil required for the operation at that time from the hydraulic pump, and no extra power is used for driving the electric motor. Can be minimized.
As a result, the battery usage time is prolonged, and long-time high-place work becomes possible.

When a plurality of operations are performed by an operator and a plurality of operation signals are output from the operation device, a hydraulic pressure is required to cause the operation device to perform a plurality of operations in accordance with the plurality of operation signals. The total oil amount required for the actuator is obtained, and drive control of the electric motor is performed so as to obtain the total oil amount. Thus, even when a plurality of operations are performed, it is possible to supply the oil amount without excess and deficiency with the necessary minimum battery power consumption, and the battery usage time is prolonged.

However, in this case, when the total oil amount exceeds the maximum oil amount output from the hydraulic pump at the maximum output of the electric motor, the total oil amount supplied to the hydraulic actuator is suppressed to the maximum oil amount or less. The operation of the control valve is controlled as described above. As a result, the amount of oil supplied to the hydraulic actuator is suppressed and the operating speed is reduced, but the operation of the hydraulic actuator can be reliably performed. That is, if the control valve opening is set as it is in accordance with each operation signal without performing the operation control of the control valve so as to suppress the total oil supply amount to the hydraulic actuator to the maximum oil amount or less, the hydraulic resistance is small. There is a possibility that a large amount of hydraulic oil is supplied to the actuator and the actuator with high hydraulic resistance may not operate.However, if the operation control is performed to keep the oil amount below the maximum oil amount as described above, the operation speed of the actuator decreases. However, there is no danger that the hydraulic actuator will not operate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of the aerial work vehicle 1 having the electric power unit 30 according to the present invention. The aerial work vehicle 1 is capable of traveling with front and rear wheels 3a and 3b, and includes a truck vehicle having a driving cabin 2a at a front portion. A turntable 5 is disposed on the vehicle body 2 so as to be horizontally turnable. The turntable 5 is driven to turn by a turn motor 15 (hydraulic motor) (not shown). Outrigger jacks 4 are provided at four front, rear, left, and right sides of the vehicle body 2, and extend downward to lift and support the vehicle body 2 when working at a high place, as shown in the figure. A boom 6 is pivotally attached to the swivel 5 and is connected to the boom 6.
Is raised and lowered by a lifting cylinder 7. This boom 6
Is telescopic, and is telescopically operated by a built-in telescopic cylinder 8.

A vertical post 9 is attached to the end of the boom 6 so as to swing up and down. The vertical post 9 is leveled by a leveling mechanism (not shown) so that it always faces vertically upward regardless of the elevation angle of the boom 6. A worktable 10 is attached to the vertical post 9 so as to be freely rotatable (swingable). A lifting device 11 is provided at the upper end of the vertical post 9.
The work table 10 is provided with an upper operation device 20 operated by an operator who gets on the work table 10. The upper operation device 20 has a turning operation lever 21 for performing a turning operation of the swivel 5, an up / down operating lever 22 for performing an up / down operation of the boom 6, and an expansion / contraction operation lever 23 for performing an expanding / contracting operation of the boom 6. A lower operating device 20 'is provided at the rear end of the vehicle body 2.

An electric power unit 30 and a battery 37 are arranged on the vehicle body 2 of the aerial work vehicle 1 having such a configuration. As shown in FIG. 1, the electric power unit 30 controls an electric motor 32 that rotates by receiving power supply from a battery 37, a hydraulic pump 31 driven by the electric motor 32, and drive current control for the electric motor 32. And a motor drive circuit 33. Electric motor 32
When the hydraulic pump 31 is driven by the
5 is discharged from a hydraulic pump 31, and the hydraulic oil is controlled by a control valve 36 and supplied to hydraulic actuators, that is, a swing motor 15, an up-and-down cylinder 7, and a telescopic cylinder 8. And
The up / down and extension / retraction operation of the boom 6 is controlled. It should be noted that a temperature sensor 34 for detecting the temperature when the electric motor 32 operates is used.
Is provided.

An operation control device of the aerial work vehicle 1 including the operation of the electric power unit 30 will be described below with reference to FIG.
This will be described with reference to FIG. This operation control device is configured to perform the operation of the control valve 35 and the drive current control by the motor drive circuit 33 in response to a control signal from the controller 25. Operation signals from the turning operation lever 21, the up / down operation lever 22, and the telescopic operation lever 23 are input to the controller 25. Each of these operation levers is configured to be tiltable from a standing state to at least one of front, rear, left, and right. When the tilt operation is performed, an operation signal proportional to the tilt angle is output to the controller 25.

The controller 25 controls the opening of the control valve 36 so that the flow rate corresponding to these operation signals is supplied to each hydraulic actuator. In this case,
The relationship between the operation signal (that is, the tilt operation angle of the operation lever) and the valve opening (that is, the flow rate supplied to the hydraulic actuator) is set to be proportional, for example, as shown in FIG. As a result, if the turning operation lever 21 is tilted, the operating oil pressure corresponding to the tilt angle is supplied to the turning motor 15, and the turning table 5 turns at a speed corresponding to the tilt angle of the turning operation lever 21. . Similarly, even when the up / down operation lever 22 or the expansion / contraction operation lever 23 is tilted, the operating oil pressure of the oil amount corresponding to each tilt angle is supplied to the up / down cylinder 7 or the expansion / contraction cylinder 8, and the tilt angle of each of the operation levers 22 and 23. The boom 6 is moved up and down at a speed corresponding to the speed of, and the telescopic operation is performed. As can be seen from this, the supply oil amount required for each actuator corresponds to the operation amount of the operation levers 21, 22, 23.

For this reason, the hydraulic oil supplied to each hydraulic actuator is supplied from the hydraulic pump 31 of the electric power unit 30 as described above.
The drive control of the electric motor 32 is performed so that the required supply oil amount corresponding to the operation amounts of 1, 2, 23 is supplied from the hydraulic pump 31 to the control valve 36. This drive control is performed by the controller 25 by the motor drive circuit 3.
The control signal is sent to the motor drive circuit 3 and the drive current from the battery 37 to the electric motor 32 is controlled by the motor drive circuit 33.

The details of this control will be described with reference to FIG. First, in step S1, the operation lever 21,
Operation signals from the operation signals 22 and 23 are detected, and a required supply flow rate Q required to operate the corresponding hydraulic actuator at a speed corresponding to the operation signals is calculated (step S2). In this case, if only one of the operation levers is operated and only one operation signal is input to the controller 25, the operation of the hydraulic actuator corresponding to the single operation signal is performed. The required flow Q to be supplied to the hydraulic actuator is calculated. on the other hand,
When a plurality of operation levers are simultaneously operated and a plurality of operation signals are input to the controller 25, a flow rate required to operate the hydraulic actuator corresponding to each operation signal is calculated, The total flow rate is calculated as the required supply flow rate Q.

Next, the process proceeds to step S3, where the temperature sensor 3
4, the operating temperature of the electric motor 32 is detected. Then, in step S4, the maximum output (motor maximum power) that the electric motor 32 can exhibit by receiving the power supply from the battery 37 with respect to the operating temperature thus detected.
Is calculated. The motor maximum power exhibits a predetermined power when the motor operating temperature is within the normal range, but when the electric motor 32 is continuously operated under a high load and the motor operating temperature becomes high, the motor operating efficiency decreases, As shown in FIG. 5, the motor maximum power decreases. For this reason,
In step S4, the motor maximum power corresponding to the motor operating temperature detected in step S3 is calculated based on, for example, the relationship in FIG. Here, the voltage of the battery 37 may be detected, and the maximum motor power may be corrected based on the detected voltage.

Next, the process proceeds to step S5, and step S4
When the electric pump 32 is driven by driving the electric motor 32 with the motor maximum power calculated in the above, the maximum discharge amount QMAX discharged from the hydraulic pump 31 is calculated. Then, in step S6, it is determined whether or not the maximum discharge amount QMAX is larger than the required supply flow rate Q calculated in step S2. Here, if it is determined that Q ≦ QMAX, there is no problem of insufficient flow rate, so the process proceeds to step S9, and drive control of the electric motor 32 is performed so that the required supply flow rate Q is obtained. Specifically, the control signal is sent from the controller 25 by the motor drive circuit 33, and the drive control of the electric motor 32 is performed so that the discharge amount of the hydraulic pump 31 becomes the required supply flow rate Q (or a slightly higher flow rate).

At this time, the opening of the control valve 36 is controlled in accordance with the operation signal. The opening degree set by this opening degree control is an opening degree for flowing the required supply flow rate Q, and supplies the discharge oil from the hydraulic pump 31 at a flow rate corresponding to the operation signal to the corresponding hydraulic actuator. Can be operated at a speed corresponding to the operation signal.

On the other hand, in step S6, Q> QMAX
If it is determined that the required supply flow rate is equal to or less than the maximum discharge rate QMAX, the flow proceeds to step S7.
Is calculated. Further, the opening of the control valve 36 corresponding to the operation signal is corrected so that each actuator can be operated according to the operation signal using the corrected flow rate Q '. Specifically, the corrected flow rate Q 'is corrected so as to be smaller than the required supply flow rate Q corresponding to the operation signal calculated in step S2, and the control valve opening is reduced using the same relationship as this correction. Make corrections.

As a result, the drive of the electric motor 32 is controlled so that the discharge amount of the corrected flow rate Q 'is obtained from the hydraulic pump 31, and the opening of the control valve 36 flows the required flow rate Q based on the operation signal. Is set to a small opening required to flow the corrected flow rate Q 'reduced and corrected, and the operating speed of the hydraulic actuator is reduced to some extent, but this can be reliably operated.

As described above, when the operation levers 21, 22, and 23 are operated, the control for driving the electric motor 32 is performed so that the supply oil amount necessary for operating the hydraulic actuator at the operation speed corresponding to the operation is obtained. Is performed, the driving of the electric motor 32 is minimized and the operation of the hydraulic actuator can be ensured. Therefore, efficient drive control of the electric motor 32 is achieved, the power consumption of the battery 37 can be minimized, and the battery usable time per charge, that is, the work time at a high place, can be extended. .

[0023]

As described above, according to the present invention,
When an operation signal is output according to the operation of the operation device, the drive control of the electric motor is performed so as to supply an oil amount required by the hydraulic actuator to perform an operation according to the operation signal. In other words, the electric motor is driven to supply only the amount of oil required for the operation at that time from the hydraulic pump, and no extra power is used for driving the electric motor. Can be minimized. As a result, the battery usage time is prolonged, and long-time high-place work becomes possible.

When a plurality of operations are performed by an operator and a plurality of operation signals are output from the operating device, a hydraulic pressure is required to cause the operating device to perform a plurality of operations in accordance with the plurality of operation signals. The total oil amount required for the actuator is obtained, and drive control of the electric motor is performed so as to obtain the total oil amount. Thus, even when a plurality of operations are performed, it is possible to supply the oil amount without excess and deficiency with the necessary minimum battery power consumption, and the battery usage time is prolonged.

However, in this case, if the total oil amount exceeds the maximum oil amount output from the hydraulic pump at the maximum output of the electric motor, the total oil amount supplied to the hydraulic actuator is suppressed to the maximum oil amount or less. The operation of the control valve is controlled as described above. As a result, the amount of oil supplied to the hydraulic actuator is suppressed and the operating speed is reduced, but the operation of the hydraulic actuator can be reliably performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control device for an aerial work vehicle including an electric power unit control device according to the present invention.

FIG. 2 is a perspective view of the aerial work vehicle.

FIG. 3 is a graph showing a relationship between a control valve opening degree and an operation angle of an operation lever.

FIG. 4 is a flowchart showing operation control contents by the electric power unit control device according to the present invention.

FIG. 5 is a graph showing the relationship between motor operating temperature and motor maximum power.

[Explanation of symbols]

 2 Body 5 Swivel table 6 Boom 7 Undulating cylinder (hydraulic actuator) 8 Telescopic cylinder (hydraulic actuator) 10 Workbench 15 Swing motor (hydraulic actuator) 20 Upper operating device 21 Swing operation lever 22 Undulating operation lever 23 Telescopic operation lever 30 Electric power unit 31 hydraulic pump 32 electric motor 36 control valve 37 battery

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroaki Mizuguchi 414-1 Higashimine Sugawa, Shinji-mura, Tone-gun, Gunma F-term (reference) 3F333 AA08 AB04 FA21 FA22 FA32 FB10 FH04 3H089 AA60 AA73 AA81 BB15 BB19 CC01 CC08 CC11 DA02 DA14 DB32 EE36 GG02 HH30 JJ20

Claims (3)

[Claims] An operating device mounted on a vehicle and operated by a hydraulic actuator, an operating device operated by an operator to control the operation of the operating device, and output in response to an operation of the operating device. An electric power unit control device for a working vehicle, comprising: a control valve that controls supply of operating hydraulic pressure to the hydraulic actuator in response to an operation signal received from the hydraulic actuator. The operating hydraulic pressure supplied to the hydraulic actuator via the control valve. And an electric motor that drives the hydraulic pump to form an electric power unit, and an oil amount required for the hydraulic actuator to operate the working device according to the operation signal is obtained. As described above, the electric power unit of the working vehicle performs the drive control of the electric motor according to the operation signal. Tsu door control device. 2. When a plurality of operations are performed simultaneously by an operator and a plurality of operation signals are simultaneously output from the operation device, a plurality of operations are performed by the operation device according to the plurality of operation signals. 2. The electric power unit control device according to claim 1, wherein a total oil amount required for the hydraulic actuator is determined to perform the driving, and drive control of the electric motor is performed so as to obtain the total oil amount. 3. 3. When the total oil amount exceeds the maximum oil amount output from the hydraulic pump at the maximum output of the electric motor, the total oil amount supplied to the hydraulic actuator is equal to or less than the maximum oil amount. 3. The operation control of the control valve is performed so as to suppress the pressure to a minimum.
3. The electric power unit control device according to claim 1.