JP3025657U - Work vehicle engine power plant - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a hydraulic work vehicle with a power supply function. SOLUTION: A variable displacement hydraulic pump 14 and a quantitative hydraulic pump 16 that are simultaneously driven by an output shaft of an engine of a work vehicle are provided. A hydraulic motor 20 driven by one of the variable displacement hydraulic pumps 14 is provided, and the traveling device of the work vehicle can be driven by this hydraulic motor. At the same time, the other metering hydraulic pump 16 is provided with two systems of oil passages 24 and 26 that can be switched via a switching valve 22, and one oil passage 24 can drive a hydraulic working machine via a hydraulic unit 28. In addition, the fixed hydraulic pump 1 is provided in the other oil passage 26.
The pressure oil from No. 6 is supplied via the flow rate control valve 36, and a power supply means including a hydraulic motor 34 that can be driven and a generator 32 connected to the hydraulic motor is provided.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to an engine power unit for a working vehicle, and more particularly to an engine power unit for a working vehicle having a power supply function in addition to a driving unit of a hydraulic machine.

[0002]

[Prior art]

 Generally, a work vehicle powered by an engine has a hydraulic work device such as a construction machine work vehicle in addition to a structure in which the traveling device and the work device are mechanically driven by the engine output as they are. Among them, there is known one that utilizes the hydraulic pressure generated by driving a hydraulic pump by an engine.

A work vehicle equipped with the hydraulic work machine has a hydraulic pump driven by an engine of the vehicle, and a motor is driven by a hydraulic pressure supplied from the pump. The hydraulic motor supplies pressure oil to each hydraulic cylinder of the hydraulic machine, causing the working machine to perform various operations. Further, the hydraulic traveling device drives the running wheels to rotate by a hydraulic motor and is widely used in construction machinery and agricultural machinery.

[0004]

[Problems to be solved by the device]

 By the way, a hydraulic vehicle equipped with a work vehicle is suitable for soil treatment and cargo handling that require force, but it is difficult to use for light work involving tools and measuring equipment. Therefore, when the work that depends on electricity such as handling tools and measuring equipment is incidental, the work vehicle and the vehicle equipped with the power supply device are towed to separately supply power.

In view of the above-mentioned conventional problems, the present invention has an object to provide an engine power unit for a working vehicle that has a power supply function in addition to a driving unit of a hydraulic machine. Secondly, it is an object of the present invention to provide an engine power unit that can stably generate electric power while using an engine as a power source. Thirdly, it is an object of the present invention to provide an engine power unit for a work vehicle having a structure in which the hydraulic working machine and the power feeding means can be switched and operated as needed, and the engine power can be effectively utilized.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, an engine power unit for a work vehicle according to the present invention firstly includes a variable displacement hydraulic pump and a constant amount hydraulic pump that are simultaneously driven by an output shaft of an engine of the work vehicle. A hydraulic motor driven by one of the variable displacement hydraulic pumps is provided so that the traveling device of the work vehicle can be driven by this hydraulic motor, and the other quantitative hydraulic pump can be switched through a switching valve. An oil passage of the system is provided, and one of the oil passages can drive the hydraulic working machine via the hydraulic unit, and the other oil passage receives the pressure oil from the above-mentioned quantitative hydraulic pump through the flow control valve. It is characterized in that it is provided with a power feeding means composed of a hydraulic motor that can be supplied and driven by a hydraulic motor and a generator connected to the hydraulic motor.

Secondly, a variable displacement hydraulic pump and a constant pressure hydraulic pump that are simultaneously driven by the output shaft of the engine of the work vehicle are provided, and a hydraulic motor that is driven by one variable displacement hydraulic pump is provided. The hydraulic motor can drive the traveling device of the work vehicle, and the other fixed type hydraulic pump is provided with two oil passages that can be switched through the switching valve, and one oil passage is provided with a hydraulic unit. The hydraulic working machine can be driven via the hydraulic working machine, and the hydraulic oil from the quantitative hydraulic pump is supplied to the other oil passage via the flow rate control valve and is connected to the hydraulic motor that can be driven and the hydraulic motor. A power supply means including a generator is provided, and the power supply means is provided with a control unit for controlling the flow rate of the flow rate control valve so as to maintain the generator output at a rated output.

Thirdly, a plurality of variable displacement hydraulic pumps that are simultaneously driven by the output shaft of the engine of the work vehicle are provided, and a hydraulic motor that is driven by one hydraulic pump is provided. In addition to being able to drive the vehicle's traveling device, the other variable displacement hydraulic pump is equipped with two oil passages that can be switched via a switching valve, and one oil passage is hydraulically operated via a hydraulic unit. A hydraulic motor capable of driving the machine and being driven by the hydraulic oil supplied from the quantitative hydraulic pump to the other oil passage via a flow control valve, and a generator connected to the hydraulic motor. And a control unit for controlling the discharge flow rate of the variable displacement hydraulic pump in order to maintain the generator output at the rated output.

[0009]

[Action]

 According to the above configuration, the hydraulic working machine or the traveling device can be driven by using hydraulic pressure that is easy to control, and it is possible to supply power to various working devices suitable for electrical control and measuring means by a single working vehicle. Become. In other words, the variable displacement hydraulic pump connected to the output shaft of the engine drives the hydraulic motor of the traveling device, which allows the work vehicle to travel at any speed while controlling the hydraulic flow rate. Become. In particular, in the first configuration, it is possible to drive the work machine such as the boom through the switching valve on the discharge side from the metering hydraulic pump, and at the same time, by switching the oil passage, the work vehicle is switched. The generator installed in the vehicle is driven by a hydraulic motor that is rotated by pressure oil. The generator will be rotated using the engine as the drive source, but by adjusting the flow control valve, stable rotation can be maintained and the generator can be operated at the rated speed. When an unstable power source is generated due to fluctuations in engine speed due to fluctuations in engine rotation, the generator output is detected as shown in the second configuration, and fluctuations are avoided if there is output fluctuation. As described above, the control means may be used to adjust the flow rate control valve.

Further, a plurality of pumps driven by the engine are set as variable displacement hydraulic pumps, one of which is used to drive a traveling device, and the other of which is a switching valve for an oil passage to two systems of a generator and a hydraulic working machine. It is possible to switch the power supply to the hydraulic working machine by supplying a predetermined discharge flow, and in order to stabilize the output when driving the generator, the generator output is detected and if there is a fluctuation in the output. The control means may adjust the discharge flow rate of the variable flow rate hydraulic pump so as to avoid the fluctuation. This is basically a variable displacement hydraulic pump configured as a swash plate pump, and the swash plate angle adjustment lever can be actuated by an actuator, or the electromagnetic adjustment means attached to the pump. Then, the control signal may drive the lever or the electromagnetic adjusting means to perform feedback control to stabilize the output and generate a stable power supply.

[0011]

[Embodiment of device]

 Hereinafter, specific embodiments of an engine power unit for a work vehicle according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment device. As shown in the figure, this engine power unit is driven by an engine 10 mounted on a bogie of a work vehicle as a power source. The output shaft 12 of the engine 10 is coaxially attached with a first pump 14 configured as a variable displacement type and a second pump 16 configured as a variable displacement type. It is driven. The variable displacement pump 16 is a swash plate pump, and the pump output can be adjusted by arbitrarily changing the swash plate angle by operating an operation lever (not shown).

The pumps 14 and 16 are used for driving a traveling device mounted on a work vehicle, a hydraulic work machine, and a generator, respectively. That is, as shown in FIG. 1, first, the variable displacement first pump 14 supplies pressure oil to a traveling hydraulic motor 20 that drives a drive wheel 18A of the traveling wheels 18 of the work vehicle. A swash plate angle of the first pump 14 is adjusted by a main controller (not shown), and the motor speed is arbitrarily changed from 0 to the maximum speed to control the speed of the work vehicle.

A fixed-quantity type second pump 18 attached to the engine output shaft 12 together with the first pump 14 simultaneously performs a pumping action, but a switching valve 22 is provided on the discharge side of the second pump 16. The switching valve 22 can selectively supply the pressure oil to the oil passages 24 and 26 of the two systems.

One of the oil passages 24 is used for driving the hydraulic working machine, and is adapted to supply pressure oil to the hydraulic cylinders 30A, 30B, 30C, ... Of the working machine via the hydraulic unit 28. , Such as driving the boom. The other oil passage 26 is used to drive the power supply means, and hydraulically drives the generator 32 mounted on the bogie of the work vehicle. As shown in the figure, a hydraulic motor 34 is directly connected to the generator 32. The hydraulic motor 34 is rotatably driven by supplying pressure oil from the second hydraulic pump 16 to the generator 32. To generate electricity.

By the way, when the flow path is switched from the second pump 16 to the oil passage 26 side by the switching valve 22 by the engine 10 as a drive source, the generator 32 passes through the hydraulic motor 34 for power generation. Although it is driven, the rotation of the motor 34 fluctuates as the rotation speed of the engine 10 is changed, and the generated power is likely to be unstable. It is necessary for the generator 32 as a power supply device to perform stable rated operation, and therefore a flow control valve 36 is provided in the oil path from the switching valve 22 to the hydraulic motor 34. This is to adjust the flow rate supplied to the hydraulic motor 34 to be constant irrespective of the engine speed, which allows the generator 32 to always be operated at the rated operation.

Here, even when the output of the engine 10 is fixed to a predetermined value, a stable rotation speed cannot be maintained, and particularly when the flow rate is lower than the control flow rate by the flow rate control valve 36, power generation is performed even when performing flow rate control. Machine output becomes unstable. A configuration for coping with such a case is shown in FIG. In the second embodiment, the flow rate control valve 36 is provided with a rated operation control means 38 so that the output of the generator does not fluctuate. As shown in FIG. 2, this is the input of the output detection unit 40 that detects the rotational output of the generator 32 and the detection signal from this output detection unit 40, and the comparison with the reference signal corresponding to the rated operation. The comparison control unit 42 is provided, and the comparison control unit 42 includes a flow rate control unit 44 that adjusts and drives the flow rate control valve 36 so as to eliminate the deviation from the reference signal. As a result, when there is a fluctuation in the output of the generator 32, this fluctuation can be suppressed and constant rated operation can be ensured, and a stable power supply can be provided.

Next, FIG. 3 shows a third example. In the third embodiment, the pumps driven by the engine 10 are both configured as variable displacement hydraulic pumps 14 and 14A, and the hydraulic working machine and the generator 32 are driven by the variable displacement hydraulic pumps. I am sorry. That is, the variable displacement hydraulic pump 14A is used as the second pump, and the switching valve 22 is provided on the discharge side so that the pressure oil can be selectively supplied to the oil passages 24 and 26 of the two systems. A hydraulic unit 28 is connected to one of the oil passages 24 used for driving the hydraulic working machine to supply pressure oil to the hydraulic cylinders 30A, 30B, 30C, ... Of the working machine. When the working machine is driven, the discharge flow rate is fixed so that the second pump 14A has a constant flow rate. Further, the other oil passage 26 used for driving the power feeding means is not provided with the flow rate control valve 36, and the generator 32 is hydraulically driven via the hydraulic motor 32.

In the third example, in order to suppress the output fluctuation of the generator 32 and perform the rated operation, the output control of the second pump configured as the variable displacement type is performed. This constitutes the 2nd pump 14A as a swash plate pump, and makes a rated operation by adjusting control of a swash plate angle. The control means for this purpose is the same as that of the second embodiment, and the output detection unit 40 for detecting the rotation output of the generator 32 and the detection signal from this output detection unit 40 are input and the rated operation is supported. And a flow rate control unit 44 for controlling the discharge flow rate of the second pump 14A so as to eliminate the deviation from the reference signal in the comparison control unit 42. That is, the control lever of the second pump 14A is feedback-controlled so that the output fluctuation of the generator 32 does not occur. Therefore, the rotational fluctuation of the engine 10 is absorbed by the flow rate control of the second pump 14A, the generator 32 is driven at a stable constant rotation, and the rated operation can be performed even by the engine power.

In the engine power unit of the work vehicle configured as described above, the rotational output of the engine 10 causes the hydraulic pumps 14 and 16 (14A) to rotate, and the first pump 14 is the traveling device and the second pump 16 is (14A) can operate the hydraulic working machine or the power generator 32 for power supply at rated operation. Therefore, especially when the first pump 14 is used for driving the traveling device, the traveling control becomes extremely easy, and the second pump 16 (14A) changes the oil passage of the switching valve 22 so that the hydraulic working machine, the tool or the measuring instrument can be used. The generator 32, which can be used for light work using electricity such as equipment, can be operated at a rated rate, and as work vehicles, work using force and work using electricity can be performed in the same work vehicle. It will be. For this reason, the work vehicle may be applied to a vehicle such as an electric wire laying work vehicle that requires power supply equipment and requires traveling drive control.

[0021]

[Effect of device]

 As described above, according to the present invention, the variable displacement hydraulic pump and the constant displacement hydraulic pump that are simultaneously driven by the output shaft of the engine of the work vehicle are provided, and the hydraulic motor driven by one of the variable displacement hydraulic pumps is provided. This hydraulic motor makes it possible to drive the traveling device of the work vehicle, and the other fixed type hydraulic pump is provided with two systems of oil passages that can be switched via the switching valve. The hydraulic engine can be driven via the unit, and the hydraulic oil from the metering hydraulic pump is supplied to the other oil passage via the flow rate control valve and can be driven by the hydraulic motor and the hydraulic motor. Control of hydraulic working machines, traveling equipment, etc. can be achieved by adopting a configuration that includes a power supply unit that is composed of a connected generator or that has a control unit that operates the generator output in rated operation. It is possible to perform power work using various hydraulic pressures, and at the same time, perform work that requires measurement and other electrical control with the engine power of the same work vehicle, and stabilizes the generator output for rated operation. Can be a power plant.

[Brief description of drawings]

FIG. 1 is a block diagram of an engine power unit according to a first example.

FIG. 2 is a block diagram of an engine power unit according to a second example.

FIG. 3 is a block diagram of an engine power unit according to a third example.

[Explanation of symbols]

 10 engine 12 output shaft 14 first pump (variable displacement hydraulic pump) 16 second pump (quantitative hydraulic pump) 14A second pump (variable displacement hydraulic pump) 18 traveling wheel 18A traveling drive wheel 20 traveling hydraulic motor 22 switching Valve 24 Oil path 26 Oil path 28 Hydraulic unit 30 Hydraulic cylinder 32 Generator 34 Hydraulic motor 36 Flow control valve 38 Rated operation control means 40 Output detection section 42 Comparison control section 44 Flow control section

Claims (3)

[Scope of utility model registration request] 1. A variable displacement hydraulic pump and a constant pressure hydraulic pump which are simultaneously driven by an output shaft of an engine of a work vehicle are provided, and a hydraulic motor driven by one of the variable displacement hydraulic pumps is provided. In addition to being able to drive the traveling device of the work vehicle, the other quantitative hydraulic pump is provided with two oil passages that can be switched via a switching valve, and one oil passage is provided with a hydraulic unit through a hydraulic unit. And a hydraulic motor that is capable of being driven by the pressure oil from the quantitative hydraulic pump supplied to the other oil passage through a flow control valve, and a generator connected to the hydraulic motor. An engine power unit for a work vehicle, which is provided with a power supply means. 2. A variable displacement hydraulic pump and a fixed amount hydraulic pump that are simultaneously driven by an output shaft of an engine of a work vehicle are provided, and a hydraulic motor driven by one of the variable displacement hydraulic pumps is provided. In addition to being able to drive the traveling device of the work vehicle, the other quantitative hydraulic pump is provided with two oil passages that can be switched via a switching valve, and one oil passage is provided with a hydraulic unit through a hydraulic unit. And a hydraulic motor that is capable of being driven by the pressure oil from the quantitative hydraulic pump supplied to the other oil passage through a flow control valve, and a generator connected to the hydraulic motor. An engine power unit for a work vehicle, comprising a power supply unit, and a control unit for controlling the flow rate of the flow rate control valve to maintain the generator output at a rated output. 3. A plurality of variable displacement hydraulic pumps simultaneously driven by an output shaft of an engine of a work vehicle are provided, a hydraulic motor driven by one hydraulic pump is provided, and a traveling device of the work vehicle is provided by the hydraulic motors. In addition to being drivable, the other variable displacement hydraulic pump is provided with two oil passages that can be switched via a switching valve, and one oil passage can drive a hydraulic working machine via a hydraulic unit. Along with the other oil passage, pressure oil from the quantitative hydraulic pump is supplied via a flow rate control valve, and a power supply means including a hydraulic motor that can be driven and a generator connected to the hydraulic motor is provided. An engine power unit for a work vehicle, wherein the power supply unit is provided with a control unit for controlling a discharge flow rate of the variable displacement hydraulic pump so as to maintain the generator output at a rated output.