JP2004236609A - Agricultural tractor - Google Patents

Abstract

An object of the present invention is to improve the working efficiency of a farm tractor, reduce fuel consumption rate, reduce harmful components in exhaust gas of an internal combustion engine, and improve "dashing phenomenon" that occurs during rotary tillage work.
A traveling unit (1A, 1B, 2A, 2B, 3A, 3B, 4) and a working machine driving unit (6, 7), an internal combustion engine 8 and a motor generator 9A serving as power sources for these, or an internal combustion engine An engine 8, a motor generator 9A, 9B, a power supply device 12 for storing electricity generated by one or both of the motor generators 9A, 9B and supplying electricity to one or both of the motor generators 9A, 9B, A control unit 13 for controlling the driving of the power source, transmitting power from the first motor generator 9A to the traveling unit, and performing work from the internal combustion engine 8 or from the internal combustion engine 8 and the second motor generator 9B. A transmission means 10 for transmitting power to the machine drive unit is provided, and the propulsion force of the machine body by driving the work machine drive unit is absorbed by the power generation of the motor generator 9A via the traveling unit, and the control unit 13 controls the first unit. Motor generator 9A, or the first By controlling the dynamic power generator 9A and the second motor generator 9B controls the speed of the aircraft.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an agricultural tractor including a traveling unit and a work implement driving unit as driving units, and more particularly to an agricultural tractor using an electric motor as a power source of the driving unit together with an internal combustion engine.
[0002]
[Prior art]
Although the agricultural tractor includes a traveling unit and a working machine driving unit as driving units, a general tractor drives the traveling unit and the working machine driving unit by only a single internal combustion engine. Fluctuation is large, and an increase in fuel consumption rate and an increase in harmful components in exhaust gas are regarded as problems.
[0003]
In order to cope with this problem, various types of so-called hybrid agricultural tractors equipped with an electric motor in addition to an internal combustion engine as a power source of a driving unit have been proposed. One of the methods includes a configuration in which a generator is mounted and power of an internal combustion engine is transmitted to a working machine drive unit and a driving system of the generator, as described in Patent Document 1 below, for example. When the load on the internal combustion engine is small, the internal combustion engine and the electric motor drive the generator in addition to the running unit and the working machine drive unit, and the generator is driven with the extra power of the internal combustion engine, thereby increasing the load on the internal combustion engine. On the other hand, when the load on the internal combustion engine by the work machine is large, the running unit and the work machine drive unit are driven by an electric motor driven by the electric power generated and stored in the internal combustion engine and the generator. . Further, as another method, as described in Patent Document 2 below, a generator is similarly mounted, a running unit and a generator are driven by an internal combustion engine, and a working machine drive unit is driven by an electric motor. is there.
[0004]
[Patent Document 1]
JP 2001-161114 A [Patent Document 2]
JP, 2001-161104, A
[Problems to be solved by the invention]
However, in the hybrid agricultural tractor of each of the above-described methods, it is difficult to work at a working speed such that the load on the internal combustion engine is always near the rated output, since the traveling portion of the agricultural tractor is usually stepped, In addition to the low effect of reducing the fuel consumption rate due to the hybridization, improvement in working efficiency is not so much expected as compared with the conventional agricultural tractor driven only by the internal combustion engine.
[0006]
In addition, in each of the above-mentioned hybrid agricultural tractors, the “dashing phenomenon” caused by the reaction force when the rotary claw cuts the soil during the rotary plowing operation, which is a typical operation of the agricultural tractor (far from the set operation speed). The problem is that the agricultural tractor itself runs at a high speed and becomes inoperable as in the case of the conventional agricultural tractor.
[0007]
Furthermore, in the above-mentioned hybrid agricultural tractor of the former type, in a relatively high load operation such as a rotary tilling operation, which is a main tractor operation in Japan, a low load operation capable of driving a mounted generator. The ratio is low and there is a problem that sufficient charging cannot be performed.In addition, in the latter case of the hybrid agricultural tractor described above, in the case of work such as rotary plowing work in which the load by the working machine is much larger than the running load, the internal combustion In spite of the fact that work can be performed near the efficient rated output of the engine, most of the load is covered by the electric motor, so that there is a problem that the fuel consumption rate increases.
[0008]
The present invention has been proposed in order to cope with such a situation, and improves the working efficiency of agricultural tractors, reduces fuel consumption, reduces harmful components in exhaust gas of internal combustion engines, and performs rotary tillage work. The purpose is to improve the "dashing phenomenon" that occurs.
[0009]
[Means for Solving the Problems]
In order to achieve such an object, an agricultural tractor according to the present invention has the features according to the following claims.
[0010]
The invention according to claim 1 is an agricultural tractor, which includes a traveling unit and a working machine driving unit as a driving unit, an internal combustion engine and an electric motor as a power source of the driving unit, and electric power generated by driving the driving unit. A power generator for storing electricity generated by the generator and supplying power to the electric motor, and a controller for controlling the driving of the power source. Transmission means for transmitting power from the internal combustion engine or from the internal combustion engine and the second electric motor to the working machine drive unit, and driving the work machine drive unit It is characterized in that the propulsion is absorbed by the power generation of the generator through the traveling section, and the traveling speed of the body is controlled by controlling the first electric motor by the control device.
[0011]
The invention according to claim 2 is the agricultural tractor described above, wherein the control of the traveling speed is controlled so that the output of the internal combustion engine becomes substantially constant.
[0012]
The invention according to claim 3 is the agricultural tractor described above, wherein the first transmission state in which the work machine drive unit is driven only by the internal combustion engine when the load of the work machine drive unit is low, and the work machine drive unit In the high load state, the internal combustion engine and the second electric motor can switch between a second transmission state for driving the work machine drive unit.
[0013]
The invention according to claim 4 is the agricultural tractor described above, wherein the switching of the transmission state is performed according to the output of the internal combustion engine.
[0014]
The invention according to claim 5 is the agricultural tractor described above, wherein the first or second electric motor is a motor generator also serving as the generator.
[0015]
The invention according to each claim having the above features has the following operations.
[0016]
First, work efficiency can be improved by the above-described features. That is, in general, the work load of the agricultural tractor increases as the work speed increases. Therefore, the work load can be kept constant by controlling the work speed by controlling the driving of the traveling unit. According to the above-described feature, in a high-load operation such as a rotary tillage operation, the traveling speed is continuously controlled so as to be the highest operation speed within the range of the rated output of the internal combustion engine, so that the operation efficiency is reduced. improves.
[0017]
Second, the fuel consumption rate can be reduced by the above-described features. That is, the driving unit is driven by the first electric motor, and the rotation speed is controlled in accordance with the load state of the work implement driving unit, or when the output of the internal combustion engine is equal to or more than a certain value, the internal combustion engine and the second motor are driven. Since the work machine drive unit is driven by the electric motor, work under a low load condition where the fuel consumption rate of the internal combustion engine is high is reduced, and work can be performed at higher speed. Therefore, fuel consumption per work area can be reduced, and the amount of carbon dioxide, which is a global warming gas, can be reduced.
[0018]
Third, harmful exhaust gas can be reduced by the above-described features. That is, the internal combustion engine and the second electric motor are used to drive the traveling unit with the first electric motor and control the rotation speed thereof according to the load state of the work implement driving unit, or when the output of the internal combustion engine is equal to or more than a certain value. As a result, since the work machine drive unit is driven, work in an overload state is reduced, and when a diesel engine is used as an internal combustion engine, generation of particulate matter in exhaust gas can be reduced. In addition, since the operation can be completed in a short time by improving the operation efficiency, the emission amount of nitrogen oxides in the exhaust gas per area can be reduced.
[0019]
Fourth, the above-described features can improve the dashing phenomenon. That is, in a work that generates a force for propelling the tractor forward, such as a rotary tillage work, this force is absorbed by a generator, stored in a power supply device, and used for a work machine drive unit. It becomes possible to prevent the dashing phenomenon in which the agricultural tractor runs at a speed much higher than the speed.
[0020]
Fifth, due to the above-mentioned characteristics, in a work in which a force for propelling the tractor forward is generated, such as in a rotary tillage work, the power is absorbed by a generator and stored in electricity, so that a comparative work like a rotary tillage work is performed. Long-time charging is possible even in operations where a particularly high load continues.
[0021]
Further, by using the first or second electric motor as the electric generator also serving as the electric generator, the structure of the agricultural tractor having the above-described functions can be simplified.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a drive system of an agricultural tractor according to one embodiment of the present invention. The agricultural tractor of the present embodiment includes a traveling unit and a work implement driving unit as driving units. The traveling section includes a transmission system including front wheels 1A and 1B and rear wheels 2A and 2B, a traveling section transmission mechanism 4, and differential devices 3A and 3B for transmitting power from the traveling section transmission mechanism 4 to the front and rear wheels 1A and 2B. . The work implement drive unit includes a drive shaft 6 that transmits power to the work implement 5, and a work implement drive unit transmission mechanism 7.
[0023]
As a power source of these drive units, an internal combustion engine 8, a first motor generator 9A, and a second motor generator 9B are mounted. A transmission unit 10 for transmitting power is provided. The transmission unit 10 is provided with clutches 11A to 11D capable of connecting and disconnecting the transmission system. In this embodiment, the first motor generator 9A and the second motor generator 9B are used. However, the first motor generator 9A and the second motor generator 9B are used as the first or second motor to generate electric power in accordance with the driving of the driving unit described above. A machine may be provided separately. A power supply device 12 is provided for storing electricity generated by the first or second motor generators 9A, 9B and for supplying electricity to the first or second motor generators 9A, 9B. .
[0024]
Further, a control device 13 is provided. The control device 13 receives a signal 13a from an exhaust gas temperature sensor 8B provided in an exhaust pipe 8A of the internal combustion engine 8, and the control device 13 transmits the signal 13a described above. Clutch control signals 13b to 13d for controlling connection and disconnection of 11B to 11D, output control signal 13e of the internal combustion engine, rotation speed control signal 13f of the first motor, and rotation speed control signal 13g of the second motor are output, respectively. It has become so.
[0025]
The power transmission system of the power transmission unit 10 controlled by the clutch control signals 13b to 13d will be described. First, the power from the internal combustion engine 8 is output via the clutch 11A which is intermittently connected by the clutch petal, and the work machine drive speed is changed. The input is input to the mechanism 7 and can be input to the traveling section transmission mechanism 4 via the clutch 11B. The power from the first motor generator 9A is input to the traveling section speed change mechanism 4 via the clutch 11C. Further, the power from the second motor generator 9B is input to the work implement drive unit transmission mechanism 7 via the clutch 11D.
[0026]
Therefore, by running the clutch 11B and disengaging the clutch 11C, the traveling unit can be driven only by the first motor generator 9A. By disengaging the clutch 11B and the clutch 11D, only the internal combustion engine 8 can operate. The work machine drive can be driven, and the work machine drive can be driven by the internal combustion engine 8 and the second motor generator 9B by disengaging the clutch 11B and engaging the clutch 11D.
[0027]
FIG. 1 shows an embodiment having an internal combustion engine 8, a first motor generator 9A, and a second motor generator 9B as power sources, but the internal combustion engine 8 and the first motor generator 9B are used as power sources. An embodiment having only the generator 9A is also possible.
[0028]
The operation of the agricultural tractor having such a configuration will be described with reference to FIG. 1 and FIGS. 2 to 4 are control flows illustrating the flow of the control operation of the control device 13 described above. In the agricultural tractor of this embodiment, an engine traveling mode in which the traveling unit is driven by the internal combustion engine 8 and a motor traveling mode in which the traveling unit is driven by the first motor generator 9A can be selected.
[0029]
This will be described with reference to FIG. 2. When the engine traveling mode is selected in the traveling mode selection (S1), the clutch 11B is engaged (S2), and the clutch 11C is disconnected (S3). When driven, the vehicle travels in the engine traveling mode (S4). This mode is not particularly related to the characteristic operation in the present embodiment. The characteristic action in the embodiment of the present invention is when the motor drive mode is selected (S1). In this case, the clutch 11B is disconnected (S5) and the clutch 11C is engaged (S6). The traveling unit is driven by the first motor generator 9A (S7).
[0030]
In this motor traveling mode, as shown in FIGS. 3 and 4, the output of the internal combustion engine is detected based on the signal 13a from the exhaust gas temperature sensor 8B input to the control device 13 (S11, S21). Then, the detected value is compared with a reference value (a value corresponding to the rated output of the internal combustion engine) to check the load state of the work implement drive unit (S12, S22).
[0031]
Then, in this motor traveling mode, a case where only the traveling speed control is performed without using the second motor generator will be described in steps S12 and subsequent steps in FIG. In this case, when the load state is the low load state, the rotation speed of the first motor generator 9A that drives the traveling unit is increased (S13), and the traveling speed is controlled to increase (S14), and the load state is increased. When the vehicle is in a high load state, control is performed to reduce the rotation speed of the first motor generator 9A that drives the traveling unit (S15) and to reduce the traveling speed (S16). According to this, the load state can be made uniform near the rated output by controlling the traveling speed.
[0032]
Next, in the motor traveling mode, the case where the traveling speed control by the first motor generator 9A and the power assist of the work implement drive unit by the second motor generator 9B are performed will be described in steps S22 and subsequent steps in FIG.
[0033]
In this case, first, when the load state is the low load state, the first transmission state in which the working machine drive unit is driven only by the internal combustion engine 8 is set. In this transmission state, a rotation speed control signal 13g is sent to first motor generator 9A, the rotation speed of first motor generator 9A is increased (S23), and the running speed is controlled to increase. (S24). Further, the clutch 11D is connected to the second motor generator 9B (S25), but the rotation speed is reduced (S26), and the second motor generator 9B is driven by the power to the work implement drive unit. Regardless of the transmission, it acts as a generator (S27) to charge the power supply device 12.
[0034]
That is, when the load is low, the working machine drive unit is driven only by the internal combustion engine 8 and the running speed is increased by controlling the rotation of the first motor generator 9A, thereby increasing the working speed and increasing the load state. Electric power is generated by the second motor generator 9B. As a result, the output of the internal combustion engine 8 can be maintained at a substantially constant value near the rated output, and the maximum working speed at that time can be obtained, so that the working efficiency can be improved.
[0035]
On the other hand, when the high load state is confirmed from the detected value of the internal combustion engine output, the rotation speed of the first motor generator 9A is reduced (S28), and the traveling speed is controlled to be reduced (S29). Further, the clutch 11D is connected to the second motor generator 9B (S30), and the rotation speed of the second motor generator 9B is increased (S31). Is transmitted to the work implement drive unit, and power assist is performed by the second motor generator 9B (S32).
[0036]
According to this, the state is switched to the second transmission state in which the work implement drive unit is driven by both the internal combustion engine 8 and the second motor generator 9B. In this case, when the working machine drive unit is under a high load, the traveling speed is reduced, and the output of the second electric motor 9B is assisted to the internal combustion engine 8. Can be suppressed. The running speed and the assist situation at this time are adjusted by the rotation speed control signals 13g, 13f sent to the first and second motor generators 9A, 9B.
[0037]
And, as described above, since the first motor generator 9A is connected to the traveling part during the work, in the work in which the propulsion force for pushing the body of the agricultural tractor forward is generated like the rotary plowing work, With this force, the first motor generator 9A is driven as a generator via the traveling unit, and this propulsion is absorbed by the power generation of the first motor generator 9A and stored in the power supply device 12, Since it can be used for driving a work machine, it is possible to prevent a dashing phenomenon associated with a rotary tillage operation.
[0038]
In addition, when such a rotary tillage operation is continued, the power storage based on the absorption of the propulsion force described above is continued. Therefore, even in an operation in which a relatively high load continues, such as the rotary tillage operation, the power supply device 12 does Long-term charging becomes possible.
[0039]
As described above, in the embodiment of the present invention, the work load can be kept constant by controlling the work speed by drive control of the traveling unit, and even in a high-load work such as a rotary tillage work, the internal combustion engine can be controlled. Within the range of the rated output, the traveling speed is steplessly controlled so as to become the highest working speed, so that the working efficiency can be improved.
[0040]
Further, the driving unit is driven by the first motor generator 9A to control the number of revolutions according to the load state of the work implement driving unit, or when the output of the internal combustion engine 8 is equal to or more than a certain value. 8 and the second motor generator 9B drive the work implement drive unit, so that work under a low load condition where the fuel consumption rate of the internal combustion engine 8 is high is reduced, and work is performed at higher speed. The fuel consumption per work area can be reduced, and the amount of carbon dioxide, which is a global warming gas, can be reduced.
[0041]
Further, the driving unit is driven by the first motor generator 9A to control the rotation speed according to the load state of the work implement driving unit, or when the output of the internal combustion engine 8 is equal to or higher than a predetermined value, Since the working machine drive unit is driven by the second motor generator 9B, work in an overload state is reduced, and when a diesel engine is used as an internal combustion engine, the generation of particulate matter in the exhaust gas can be reduced. it can. In addition, since the work can be completed in a short time by improving the work efficiency, it is possible to reduce the amount of nitrogen oxides per unit area in the exhaust gas.
[0042]
Further, in a work in which a force for propelling the body forward is generated, such as in a rotary tillage work, this force is absorbed by the power generation action of the first motor generator 9A and stored in the power supply device 12, and this work is performed. Since it can be used for the machine drive unit, it becomes possible to effectively prevent the dashing phenomenon during the rotary tillage operation.
[0043]
Further, in a work in which a force for propelling the body forward is generated, such as a rotary tillage work, the power is absorbed and stored, so that even in a work with a relatively high load such as a rotary tillage work, a long time is required. Can be charged. Further, since the first or second motor generators 9A and 9B are used, the structure of the agricultural tractor can be simplified and the cost can be reduced as compared with the case where a generator is mounted separately from the motor. Becomes possible.
[0044]
【The invention's effect】
Since the present invention is configured as described above, the working efficiency of the agricultural tractor is improved, the fuel consumption rate is reduced, the harmful components in the exhaust gas of the internal combustion engine are reduced, and the “dashing phenomenon” that occurs during the rotary plowing operation is improved. Is possible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a drive system of an agricultural tractor according to an embodiment of the present invention.
FIG. 2 is a control flow showing a control operation of a control device according to the embodiment of the present invention.
FIG. 3 is a control flow showing a control operation of a control device according to the embodiment of the present invention.
FIG. 4 is a control flow showing a control operation of the control device according to the embodiment of the present invention.
[Explanation of symbols]
(Traveling part)
DESCRIPTION OF SYMBOLS 1A, 1B Front wheel 2A, 2B Rear wheel 3A, 3B Differential device 4 Traveling speed change mechanism 5 Work machine (work machine drive unit)
Reference Signs List 6 drive shaft 7 work implement drive unit transmission mechanism 8 internal combustion engine 9A first motor generator 9B second motor generator 10 transmission unit 11A to 11D clutch 12 power supply device 13 control device 13a signal 13b to 13d clutch control signal 13e output Control signal 13f, 13g Rotation speed control signal

Claims (5)

A traveling unit and a working machine driving unit as a driving unit, an internal combustion engine and an electric motor as a power source of the driving unit, a generator that generates electric power by driving the driving unit, and stores electricity generated by the generator. A power supply device for supplying electricity to the electric motor, and a control device for controlling the drive of the power source,
And a transmission unit that transmits power from the first electric motor to the traveling unit, and transmits power from the internal combustion engine or from the internal combustion engine and the second electric motor to the working machine drive unit,
The driving force of the airframe by driving the work machine drive unit is absorbed by the power generated by the generator via the traveling unit, and the control unit controls the first electric motor to control the traveling speed of the airframe. Agricultural tractor characterized by the following. The agricultural tractor according to claim 1, wherein the control of the traveling speed is controlled so that the output of the internal combustion engine becomes substantially constant. The transmission means includes: a first transmission state in which the work machine drive unit is driven only by the internal combustion engine when the work machine drive unit is under a low load; and the internal combustion engine and the second The agricultural tractor according to claim 1 or 2, wherein the electric motor is capable of switching between a second transmission state in which the work machine driving unit is driven. The agricultural tractor according to claim 3, wherein the switching of the transmission state is performed according to an output of the internal combustion engine. The agricultural tractor according to any one of claims 1 to 4, wherein the first or second electric motor is a motor generator also serving as the generator.

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