JP2013203377A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle including a hydraulic vehicle operation device that performs motor-driven pump control more effective in battery consumption.SOLUTION: A vehicle includes: a hydraulic vehicle operation device 9 formed of a motor-driven hydraulic pump 93 for supplying oil pressure to a hydraulic actuator 92; a battery B which supplies electric power to the motor-driven hydraulic pump 93; an operation tool 21 which applies a manipulated variable for the vehicle operation device 9; a pump rotating speed calculation part 55 which calculates a rotating speed of the motor-driven hydraulic pump 93 required to supply the oil pressure to the hydraulic actuator 92 by using operation information on the manipulated variable as an input parameter; and a hydraulic pump control part 56 which outputs a control signal to the motor-driven hydraulic pump 93 so as to drive the motor-driven hydraulic pump 93 at the calculated pump rotating speed.

Description

  The present invention relates to a vehicle including a hydraulic vehicle operation device incorporating a hydraulic actuator and an electric hydraulic pump that supplies hydraulic pressure to the hydraulic actuator.

  As a vehicle that employs a transmission hydraulic operation mechanism as a hydraulic vehicle operation device, a transmission hydraulic pump provided in the transmission is driven by an electric motor for driving, and a transmission hydraulic pressure supplied from the transmission hydraulic pump is also provided. Is controlled by a controller to achieve a desired gear ratio. In a transmission in which such a transmission hydraulic pump is driven by an electric motor, in order to avoid a situation where a smooth shift cannot be performed due to a delay in the rise of the shift hydraulic pressure, the electric motor is constantly rotated to change the speed. The transmission hydraulic pressure is always supplied to the machine. However, if the electric motor is always rotated, the battery is wasted and it is uneconomical. In order to solve this problem, in the hydraulic control device for a transmission according to Patent Document 1, the shift lever is set to the parking range or the neutral range, and the hand brake is applied to the electric motor that drives the transmission hydraulic pump. In addition, the electric motor is stopped when the accelerator pedal is not depressed, and the electric motor is activated when at least the handbrake is returned or the accelerator pedal is depressed with the shift lever set to the parking range or the neutral range. ing. In other words, by determining the ON / OFF control timing of the electric hydraulic pump according to the vehicle operation state, the electric hydraulic pump, that is, the electric motor that drives the pump is prevented from rotating unnecessarily, and the battery consumption is suppressed. ing. In this hydraulic vehicle operation device, the battery consumption is suppressed by controlling the ON / OFF of the electric hydraulic pump at the timing when the hydraulic pressure is required. However, the hydraulic pressure is optimized by adjusting the rotation speed of the hydraulic pump. It is not taken into consideration to control such as.

  Further, Patent Document 2 discloses a vehicle equipped with a vehicle electrohydraulic power steering device using an electric hydraulic pump as a hydraulic vehicle operating device. In this vehicle electrohydraulic power steering apparatus, when the steering wheel is operated, the steering wheel is steered through the steering mechanism in accordance with this operation. At this time, the electric hydraulic pump operates using the electric motor as a drive source to drive the hydraulic oil, and this hydraulic oil is supplied to the piston mechanism through the hydraulic circuit, and the steering in the steering mechanism is assisted by the piston mechanism. . The operation of this electric hydraulic pump is controlled by the pump control means based on the detection signal from the steering angle detection means. In particular, the steering angle detected by the straight angle determination means by the steering angle detection means is less than a predetermined amount. If it is determined that the vehicle is in the straight traveling mode when the change frequency of the steering state is equal to or greater than a predetermined value, the operation of the electric hydraulic pump is stopped by the pump stop means provided in the pump control means. If the steering angle is constant during straight running, battery consumption is suppressed by stopping the electric hydraulic pump. However, in the case of a work vehicle such as a tractor that is operated at a large steering angle, various steering processes In this case, since the required hydraulic amount to be supplied to the hydraulic circuit is different, it is not sufficient to simply perform the ON / OFF control of the electric hydraulic pump on the condition of straight traveling and turning traveling.

Japanese Patent Laid-Open No. 07-174218 Japanese Patent Laid-Open No. 06-107215

  In view of the above circumstances, there is a demand for a vehicle including a hydraulic vehicle operation device that performs more effective electric pump control with respect to battery consumption.

  In order to solve the above-described problems, a vehicle according to the present invention includes a hydraulic vehicle operating device incorporating a hydraulic actuator, an electric hydraulic pump that supplies hydraulic pressure to the hydraulic actuator, and a battery that supplies electric power to the electric hydraulic pump. An operation tool that provides an operation amount for the hydraulic vehicle operation device, an operation amount detection unit that detects the operation amount, and operation information related to the operation amount that is necessary for supplying hydraulic pressure to the hydraulic actuator as input parameters. A pump rotation number calculation unit that calculates the pump rotation number of the electric hydraulic pump, and a control signal is output to the electric hydraulic pump so that the electric hydraulic pump is driven at the pump rotation number calculated by the pump rotation number calculation unit And a hydraulic pump control unit.

  With this configuration, the pump rotation speed of the electric hydraulic pump that should satisfy the hydraulic pressure required by the operation is calculated according to the operation amount of the operation tool for the hydraulic vehicle operation device, and the calculated pump rotation speed is calculated. The electric hydraulic pump is driven and controlled as a target. Thereby, compared with simple ON / OFF control of the electric hydraulic pump, more effective electric pump control with respect to battery consumption is realized.

  If the battery rises, it will adversely affect the quality maintenance of the battery, and the vehicle may become inoperable. Therefore, it is necessary to prevent the battery from going up. For this reason, it is preferable not only to control the rotational speed of the electric hydraulic pump only from the operability of the hydraulic vehicle operating device but also to consider the charge amount of the battery. For this reason, in a preferred embodiment of the present invention, a charge amount calculation unit for calculating the charge amount of the battery is provided, and the charge amount is an additional input parameter. Used to calculate numbers.

  In one preferred embodiment of the present invention, the operation tool is a steering wheel, the hydraulic vehicle operation device is a power steering device, and the operation information related to the operation amount is a steering angle or a steering angular velocity or a steering angle velocity thereof. Both. In a work vehicle or the like, a steering operation with a large steering angle is frequently performed. Therefore, it is important to supply an appropriate hydraulic pressure to the hydraulic circuit of the power steering apparatus. In the operation of the steering wheel, the amount of hydraulic pressure required also varies depending on the angle value of the steering angle and the operating speed during the operation, that is, the steering angular speed. Therefore, it is convenient if the rotation speed of the electric hydraulic pump is calculated based on the steering angle and the steering angular velocity.

  The electric hydraulic pump control of the hydraulic vehicle operating device described above is particularly advantageous in a vehicle that has severe restrictions on battery consumption, such as a hybrid vehicle, because the battery consumption is optimally suppressed. Therefore, a preferred application example of the vehicle according to the present invention is an electrically driven vehicle in which the battery is also used as a travel drive motor generator.

It is a schematic diagram explaining the basic principle of the hydraulic vehicle operating device employ | adopted by this invention. It is a schematic diagram which shows the specific control structure and its control flow in the power steering apparatus by FIG. It is a graph which shows the relationship between the steering angle and the required pump rotation speed estimated from the steering angle. It is a graph which shows the relationship between steering angular velocity and the required pump rotation speed estimated from the steering angular velocity. 1 is a perspective view of a general-purpose tractor that is one embodiment of a vehicle according to the present invention. It is a schematic diagram which shows the power system of a tractor. It is sectional drawing of the motor generator with which the tractor was equipped. It is a perspective view which shows the outline | summary of the power steering apparatus of a tractor. It is a hydraulic circuit diagram which shows the outline of the hydraulic system of a tractor.

  Before explaining a specific embodiment of a vehicle equipped with a hydraulic vehicle operating device according to the present invention, the basic principle of the hydraulic vehicle operating device employed in the present invention will be described with reference to FIG. To do. The vehicle illustrated in FIG. 1 is a hybrid work vehicle, and a power steering device 9 is handled as a hydraulic vehicle operation device.

  The power steering device 9 includes a steering wheel 21 disposed above the handle post 22 and a power steering hydraulic circuit 90 that changes the steering angle of the steering wheel 2a using the steering operation by the steering wheel 21 as an input. ing. The power steering hydraulic circuit 90 includes a power steering hydraulic control unit 91 that functions as a power steering control valve that receives the rotational displacement of the steering wheel 21 as an operation input, and a power steering hydraulic cylinder 92 as a hydraulic actuator that changes the steering angle of the steering wheel 2a. And a power steering electric hydraulic pump 93 as a hydraulic supply source, and each is connected by a hydraulic pipe. A power steering electric hydraulic pump (hereinafter simply referred to as an electric hydraulic pump) 93 includes a pump unit and a motor unit that provides rotational power to the pump unit. The electric power is supplied to the electric hydraulic pump 93, more precisely, the motor unit by the driver 71, and the motor unit, that is, the electric hydraulic pump 93 is rotated at a rotational speed (rotational speed per hour; rotational speed) depending on the amount of power supplied. Changes.

  The vehicle power management unit 5 substantially constructed as a computer system includes a pump rotation number calculation unit 55 and a hydraulic pump control unit 56 as functional units related to the power steering device 9. The power management unit 5 is connected to a vehicle state detection unit S to which signals such as various sensors and switches are input. The power management unit 5 is a rotation angle as an operation amount of the steering wheel 21, that is, a steered wheel 2a. Steering angle information related to the steering angle from the steering angle sensor S1 as an operation amount detection unit that detects the steering angle of the vehicle can also be received via the vehicle state detection unit S.

  The pump rotation speed calculation unit 55 calculates the pump rotation speed of the electric hydraulic pump 93 required for supplying hydraulic pressure to the power steering hydraulic cylinder 92 using the steering angle information as an input parameter. The hydraulic pump control unit 56 outputs a control signal to the driver 71 so that the electric hydraulic pump 93 is driven at the pump rotation number calculated by the pump rotation number calculation unit 55. Based on this control signal, the driver 71 supplies the necessary amount of power from the battery B to the electric hydraulic pump 93, so that the electric hydraulic pump 93 is driven at a desired rotational speed, and an appropriate amount of hydraulic pressure is supplied to the power steering hydraulic circuit 90. Will be supplied.

  This hybrid work vehicle includes an internal combustion engine E and a motor generator 4 as drive sources, and travels with at least the rear wheels 2b as drive wheels. The motor generator 4 generates rotational power as a power supply source from the battery B and runs the hybrid work vehicle in cooperation with the internal combustion engine E. However, the motor generator 4 is driven by the internal combustion engine E or is hybrid. The motor generator 4 can function as a generator for supplying electric power to the battery B under a situation where the work vehicle is decelerating or under an inertia traveling downhill.

  The rotation control of the internal combustion engine E is performed by the engine control unit 6 via an engine control device 60 such as an electronic governor mechanism or a common rail mechanism. The drive control of the motor generator 4 is performed by the motor control unit 7 via the inverter unit 70. The engine control unit 6 is a computer unit for controlling the fuel injection amount of the internal combustion engine E and has a constant speed control function for controlling the engine control device 60 so as to maintain the rotation speed of the internal combustion engine E constant. . The motor control unit 7 is also a computer unit, and gives a control signal to the inverter unit 70 in order to control the rotation speed and torque of the motor generator 4. Further, the motor control unit 7 includes an assist drive mode for outputting power to the power transmission shaft 30 and a charge drive mode for outputting charging power to the battery B as drive modes for the motor generator 4. As is well known, the inverter unit 70 converts the DC voltage of the battery B into an AC voltage and supplies it to the motor generator 4. When the motor generator 4 operates as a generator, the inverter unit 70 applies the DC voltage to the battery B. It also functions as a rectifier and a voltage regulator for supplying. That is, the battery B operates in a discharging process for supplying electric power to the motor generator 4 via the inverter unit 70, and is charged by the electric power generated by the motor generator 4 when the motor generator 4 operates as a generator. It works with the charging process.

Next, a specific control structure and control flow in the power steering device 9 operating on the basic principle described above will be described with reference to FIG.
When the steering wheel 21 is operated by the driver, the steering angle (indicated by θ in FIG. 2), which is the operation amount, is detected by the steering angle sensor S1. A steering angle detection signal indicating the detected steering angle is sent to the vehicle state detection unit S, and necessary preprocessing is performed. Here, the vehicle state detection unit S generates a steering angle and a steering angular velocity (shown as dθ / dt in FIG. 2) from the steering angle detection signal sent over time, and rotates the pump. It is sent to the number calculation unit 55. The pump rotation speed calculation unit 55 calculates a pump rotation speed that is a control target of the electric hydraulic pump 93 that constitutes the power steering hydraulic circuit 3 using the steering angle and the steering angular velocity. At that time, the pump rotation speed: rpm per minute is calculated by weight calculation using the steering angle: θ and the steering angular speed: dθ / dt as parameters (variables), and an example of the weight calculation formula is as follows:
rpm = 1200 + θ × α + dθ / dt × β
Here, α is a steering angle weighting factor, and β is a steering angular velocity weighting factor.
The constant term “1200” is the basic rotational speed, for example, the pump rotational speed when the steering wheel 21 is positioned in the neutral region. By driving the electric hydraulic pump at this basic rotational speed, the minimum required hydraulic amount is secured in the target power steering hydraulic circuit 90. For example, in the case of a gear-type pump, the hydraulic pressure required for gear lubrication is not supplied. Realize.

  As can be understood from the above weight calculation formula, the required hydraulic pressure (flow rate) is estimated from the two variables of the steering angle (cutting angle) and the steering angular speed of the steering wheel 21, and the required pump rotation speed is obtained. Yes. Each weighting factor is a function of the steering angle and the steering angular velocity, so that an accurate pump speed can be obtained.

  The relationship between the steering angle and the required pump speed estimated from the steering angle is illustrated in FIG. Further, FIG. 4 illustrates the relationship between the steering angular velocity and the necessary pump rotational speed estimated from the steering angular velocity. It is convenient to create a table for reading the pump rotation speed from the steering angle and the steering angular velocity based on such a relationship and set it in the pump rotation speed calculation unit 55.

  The pump speed finally calculated by this weight calculation is sent to the pump control unit 56. The pump control unit 56 sends a control signal to the motor of the electric hydraulic pump 93 via the driver 71 so that the electric hydraulic pump 93 is driven with the received pump rotation speed as the target rotation speed. As a result, the hydraulic pressure suitable for the amount of operation of the steering wheel 21 is supplied to the power steering hydraulic circuit 90 of the power steering device 9.

  It is also useful to use the charge amount (SOC) of the battery B calculated by the charge amount calculation unit 54 as an additional parameter when the pump rotation number calculation unit 55 calculates the pump rotation number. In other words, when the charge amount is low, the charge amount is used as a parameter for lowering the target pump rotation speed and / or the basic rotation speed. Use of the electric hydraulic pump 93 is realized.

  Next, a specific embodiment of a vehicle provided with a hydraulic vehicle operating device according to the present invention will be described. In this embodiment, the vehicle is a general-purpose tractor incorporating a hybrid drive system as shown in FIG. The power system of this tractor is schematically shown in FIG. The tractor vehicle body includes an internal combustion engine E, a motor generator 4, a hydraulically driven main clutch 31, a transmission 10, a driving unit 20, a pair of left and right front wheels 2a and a rear wheel 2b as the traveling device 2. . Further, a tilling device is mounted as a working device W at the rear portion of the vehicle body by a lifting mechanism (not shown). The lifting mechanism is operated by a hydraulic cylinder.

  As schematically shown in FIG. 6, the internal combustion engine E of this tractor is a diesel engine (hereinafter abbreviated as “engine E”) whose rotation is controlled by a common rail system, and a common rail control device is used as the engine control device 60. I have. The transmission 10 includes a hydraulic mechanical continuously variable transmission (hereinafter abbreviated as HMT) 12, a forward / reverse switching device 13, a gear transmission 14 that performs a multi-stage shift, and a differential mechanism 15. The drive wheel (front wheel 2a and / or rear wheel 2b or both) 2 is finally rotated through the transmission shaft 30. Each of the forward / reverse switching device 13 and the gear transmission 14 is provided with a hydraulically driven transmission clutch 10a. Further, the cultivator W mounted on the tractor can receive the rotational power via the PTO shaft W1 that constitutes a part of the power transmission shaft 30 that transmits the rotational power of the engine E and the motor generator 4, and thus the tillage power can be received. The rotor is driven to rotate at a predetermined tilling depth.

  The HMT 12 includes a hydrostatic transmission mechanism 12A including a swash plate type variable discharge hydraulic pump that receives power from the engine E and the motor generator 4, and a hydraulic motor that rotates by hydraulic pressure from the hydraulic pump and outputs power. And a gear mechanism 12B. The planetary gear mechanism 12B is configured to receive the power from the engine E and the motor generator 4 and the power from the hydraulic motor as inputs, and to supply the speed change output to the power transmission shaft 30 at the subsequent stage.

  In the hydrostatic transmission mechanism 12A, power from the engine E and the motor generator 4 is input to the pump shaft, whereby pressure oil is supplied from the hydraulic pump to the hydraulic motor, and the hydraulic motor is rotated by the hydraulic pressure from the hydraulic pump. Driven to rotate the motor shaft. The rotation of the hydraulic motor is transmitted to the planetary gear mechanism 12B through the motor shaft. The hydrostatic transmission mechanism 12A changes the angle of the swash plate by displacing the cylinder that is linked to the swash plate of the hydraulic pump, so that the forward rotation state, the reverse rotation state, and the normal rotation state and the reverse rotation state are reversed. The hydraulic pump rotates by changing the rotational speed of the hydraulic pump steplessly, even when the gear is shifted to the neutral state located between the states and is shifted to the forward rotation state or the reverse rotation state. Change the speed (number of revolutions per hour) steplessly. As a result, the rotational speed of the power output from the hydraulic motor to the planetary gear mechanism 12B is changed steplessly. The hydrostatic transmission mechanism 12A stops the rotation of the hydraulic motor by the hydraulic pump when the swash plate is positioned in a neutral state, and consequently stops the output from the hydraulic motor to the planetary gear mechanism 12B.

  The planetary gear mechanism 12B meshes with the sun gear, the three planetary gears arranged at regular intervals around the sun gear, the carrier that rotatably supports each planetary gear, and the three planetary gears. A ring gear and an output shaft (one of the power transmission shafts 30) connected to the forward / reverse switching device 13 are provided. In this embodiment, the carrier forms a gear portion that meshes with an output gear attached to the power transmission shaft 30 on the engine E side on the outer periphery, and is supported by the boss portion of the sun gear so as to be relatively rotatable.

  With the above-described configuration, the HMT 12 changes the power transmission to the front wheels 2a and / or the rear wheels 2b that are driving wheels steplessly by changing the swash plate angle of the hydrostatic transmission mechanism 12A. Can do. This swash plate control is realized by hydraulic control of a hydraulic control unit 80 that operates based on a control command from the transmission control unit 8.

  Control of the motor generator 4 in this power system, that is, torque assist for the engine E is performed by a motor control unit 7 constructed in the power management unit 5. The power management unit 5 also includes the control function unit for the power steering device 9 described with reference to FIG. 1, that is, the charge amount calculation unit 54, the pump rotation number calculation unit 55, and the pump control unit 56. Has been. The power management unit 5 can transmit data with the vehicle state detection unit S, the shift control unit 8 for shifting operation in the transmission 10, the work device control unit 99 for operating the tilling device W, and the like via an in-vehicle LAN. It is connected. The transmission control unit 8 and the work device control unit 99 control the hydraulic equipment via the hydraulic control unit 80. Therefore, the pump rotation speed calculation unit 55 and the pump control unit 56 as the control function unit for the power steering device 9 may also be constructed without the transmission control unit 8 or the work device control unit 99, and independent from them. You may build it into a unit.

  The vehicle state detection unit S inputs signals from various sensors arranged in the tractor and operation input signals indicating the state of an operating device (clutch pedal or brake pedal) operated by the driver, and if necessary Then, signal conversion and evaluation calculation are performed, and the obtained signals and data are sent to the in-vehicle LAN.

  The motor generator 4 has both a function of a three-phase AC generator that generates electric power by the driving force of the engine E and a function of a three-phase AC motor that rotates by electric power supplied from the outside. Inverter unit 70 converts DC power from battery B into three-phase AC power and supplies it to motor generator 4. The inverter unit 70 converts the three-phase alternating current generated by the motor generator 4 into a direct current, boosts it, and supplies it to the battery B.

  As shown in FIG. 7, the engine E, the motor generator 4 and the main clutch 31 are provided in this order, and the motor housing 40 is connected to the rear end plate 40a connected to the rear portion of the engine E. 40 includes a motor generator 4 and a main clutch 31. The motor generator 4 includes a rotor 42 having a permanent magnet 41 on the outer periphery, and a stator 43 disposed at a position surrounding the rotor 42. The stator 43 is formed on a plurality of teeth (not shown) of the stator core. It has a structure in which a coil is wound. Opposite the shaft end of the output shaft Ex (crankshaft) of the engine E, the rotor 42 of the motor generator 4 is arranged coaxially with the rotational axis X of the output shaft Ex, and of the rotor 42, the output shaft Ex The base plate 31a of the main clutch 31 is disposed on the opposite surface, and the output shaft Ex, the rotor 42, and the base plate 31a of the main clutch 31 are screw-connected. Although the base plate 31a also has a function as a flywheel, as described above, the motor generator 4 partially performs the inertial force function that the flywheel has performed, and thus is lighter than the conventional one. The motor housing 40 has a structure in which the front housing 40A and the rear housing 40B are connected in a separable manner. When the motor generator 4 is assembled, the stator 43 is provided on the inner surface of the front housing 40A. The front housing 40A is connected to the rear end plate 40a, and then the rotor 42 is connected to the rear end of the output shaft Ex.

  The main clutch 31 includes a clutch disk 31c, a pressure plate 31d, and a diaphragm spring 31e disposed in a clutch cover 31b connected to the rear surface of the base plate 31a, and a power transmission shaft that transmits the driving force from the clutch disk 31c. 30 and a clutch shaft 30a as one component, and is operated by a clutch pedal (not shown). The clutch shaft 30a is supported so as to be rotatable about the rotational axis X with respect to the rear housing 40B, and the clutch disk 31c is capable of transmitting torque to the clutch shaft 30a by a spline structure, and is connected to the rotational axis X. The diaphragm spring 31e has a configuration in which a biasing force in the clutch engagement direction is applied to the clutch disk 31c via the pressure plate 31d. The power of the clutch shaft 30a is transmitted to an intermediate transmission shaft 30b as one component of the power transmission shaft 30 that serves as an input shaft of the transmission 10 via a gear transmission mechanism.

  Drive control of the engine E and the motor generator 4 is performed by the engine control unit 6 and the traveling motor control unit 7. The engine control unit 6 acquires a signal from an accelerator pedal sensor, an engine rotation signal, a fuel pressure signal in a common rail, an intake pressure signal of an intake portion, and the like, and fuel injection by a common rail fuel injection device as the engine control device 60 To control.

  The engine control unit 6 operates the engine E in a low speed region with good fuel efficiency in order to improve fuel efficiency, but when it is considered that the load acting on the engine E exceeds the threshold value, the motor control unit 6 Based on the control signal from the unit 7, the power from the battery B is converted into three-phase AC power by the inverter unit 70 and supplied to the motor generator 4. The engine E is assisted by the driving force of the motor generator 4 thereby. In particular, when a decrease in engine speed is detected due to a sudden increase in engine load during constant speed work, the traveling motor control unit 7 causes the motor generator to compensate at least partially for the increase in engine load. The torque assist process using 4 is executed, so that an unexpected decrease in engine speed and engine stall are avoided. Further, when it is considered that the load acting on the engine E is less than the threshold value, the traveling motor control unit 7 supplies the generated power from the motor generator 4 to the battery B via the inverter unit 70 and supplies the battery B Execute the control to charge.

  Although schematically shown in FIG. 8, the power steering device 9 of this tractor is substantially the same as that described in FIG. The handle post 22 has a fixed post portion 22b attached to the vehicle body extending in the transverse direction of the vehicle body, and a swing post portion 22a connected to the fixed post portion 22b through a tilt mechanism 23 so as to be swingable about the swing axis. It consists of. The fixed post portion 22b and the swing post portion 22a have a panel structure, the fixed post portion 22b is a cylinder having a quadrangular cross section formed of a side plate, and the swing post portion 22a is covered with an upper portion formed of the side plate and the top plate. Cylinder. The basic principle described with reference to FIGS. 1 and 2 is applied to the configuration and control of the power steering hydraulic circuit 90 as it is. The power steering hydraulic cylinder 92 is incorporated in the steering mechanism of the front wheel 2a which is the steering wheel of the work vehicle.

  FIG. 9 is a hydraulic circuit diagram of the hydraulic circuit system of the tractor. The hydraulic circuit 81 of the hydrostatic transmission mechanism 12A constituting the HMT 12, the hydraulic circuit 82 of the lifting mechanism that lifts and lowers the work device W, and the power steering hydraulic circuit described above. Although 90 is shown, the hydraulic circuit of the main clutch 31 and the transmission clutch 10a is omitted. The hydraulic circuit 81 of the hydrostatic transmission mechanism 12 </ b> A includes a swash plate control type hydraulic pump 81 a and a charge pump 82 b that are driven by the power of the engine E and the motor generator 4 as hydraulic supply sources. The rotational speed of the hydraulic motor rotated by the hydraulic oil supplied from the hydraulic pump 81a in the normal rotation and reverse rotation is changed by adjusting the swash plate angle of the hydraulic pump by the swash plate adjusting mechanism including the swash plate control valve. The hydraulic circuit 82 of the elevating mechanism includes an elevating electric hydraulic pump 82a driven by an electric motor M as a hydraulic supply source, and an elevating lever 25 as an operation tool. Also in the hydraulic circuit 82 of the lifting mechanism, control for calculating the rotation amount of the lifting electric hydraulic pump 82a may be performed so that only a necessary amount of hydraulic pressure is supplied based on the operation amount of the lifting lever 25. .

  In each hydraulic circuit included in the hydraulic circuit system, the hydraulic oil supplied by the hydraulic pumps 81a, 82a, and 93 is also used as lubricating oil for gears and the like, so that the amount of operation by each operating tool is zero. Even if it is near zero, each hydraulic pump is rotated to the extent that a certain amount of oil pressure (necessary for lubrication purposes) is secured in the hydraulic circuit, avoiding inconvenience due to complete stop. .

[Other Embodiments]
(1) In the above-described embodiment, the operation amount of the operation tool (such as the steering wheel 21 and the lift lever 25) is detected by the sensor. Indirect manipulated variable detection, such as detecting, may be employed.
(2) In the pump rotation speed derivation based on the steering angle in the pump rotation speed calculation unit 55, the vehicle travel speed may be additionally employed as the input parameter. More specifically, when the map (table) in which the input parameters are the steering angle and the steering angular speed and the pump rotation speed is derived is used, the map is changed according to the vehicle traveling speed and the used shift position. Such a configuration can be adopted.
(3) In the above-described embodiment, the engine E and the motor generator 4 are directly connected, and the main clutch 31 is then mounted and the power is transmitted to the power transmission shaft 30. The main clutch 31 may be mounted between the motor generator 4 and the motor generator 4.
(4) Although the hybrid drive tractor is taken up as a vehicle in the above-described embodiment, a tractor or other vehicle driven only by the engine may be used.

  The present invention can be applied to various vehicles equipped with a hydraulic vehicle operation device incorporating a hydraulic actuator and an electric hydraulic pump that supplies hydraulic pressure to the hydraulic actuator. For example, in addition to a tractor, examples of such a vehicle include a riding rice transplanter, a lawn mower, a work vehicle such as a combine, or a bus or a truck.

2a: Front wheel (steering wheel / drive wheel)
2b: Rear wheel (drive wheel)
10: Transmission 16: Shift clutch 20: Driving unit 21: Steering wheel (operating tool)
4: Motor generator (motor generator for driving)
30: Power transmission shaft 31: Clutch 5: Vehicle control unit 54: Charge amount calculation unit 55: Pump rotation speed calculation unit 56: Pump control unit (hydraulic pump control unit)
6: Engine control unit 7: Motor control unit 70: Inverter unit 9: Power steering device (hydraulic vehicle operation device)
90: Power steering hydraulic circuit 91: Power steering control unit 92: Power steering hydraulic cylinder (hydraulic actuator)
93: Power steering electric hydraulic pump (electric hydraulic pump)
W: Work device W1: PTO shaft W2: PTO clutch S: Vehicle state detection unit S1: Steering angle sensor (operation amount detection unit)
B: Battery E: Internal combustion engine

Claims (4)

A hydraulic vehicle operating device incorporating a hydraulic actuator and an electric hydraulic pump for supplying hydraulic pressure to the hydraulic actuator;
A battery for supplying electric power to the electric hydraulic pump;
An operating tool for giving an operation amount to the hydraulic vehicle operating device;
An operation amount detection unit for detecting the operation amount;
A pump rotation number calculation unit for calculating a pump rotation number of the electric hydraulic pump required for supplying hydraulic pressure to the hydraulic actuator using operation information related to the operation amount as an input parameter;
A hydraulic pump controller that outputs a control signal to the electric hydraulic pump such that the electric hydraulic pump is driven at the pump rotational speed calculated by the pump rotational speed calculator;
Vehicle equipped with.   The vehicle according to claim 1, further comprising a charge amount calculation unit that calculates a charge amount of the battery, wherein the charge amount is used as an additional input parameter for calculating the pump rotation number in the pump rotation number calculation unit.   The vehicle according to claim 1, wherein the operation tool is a steering wheel, the hydraulic vehicle operation device is a power steering device, and the operation information regarding the operation amount is a steering angle and / or a steering angular velocity. .   The vehicle according to any one of claims 1 to 3, wherein the battery is also used as a travel drive motor generator.

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