Field work machines

Abstract

The present invention provides a field work machine capable of appropriately driving a work device and assisting travel. The field work machine shown as an example comprises: a travel machine body having a travel device; a work device supported by the travel machine body; a prime mover that supplies driving force to the travel device; a first rotating motor that is connected to an output shaft of the prime mover in a manner capable of transmitting power; and a second rotating motor that supplies driving force to the work device.

Description

Technical Field

[0001] The invention relates to a field working machine. Background Art

[0002] Conventionally, a hybrid working vehicle that uses an electric generator to assist an internal combustion engine is known (see, for example, Patent Document 1). In a hybrid working vehicle, the vehicle is driven by the power from the internal combustion engine, and when a large load is generated on the internal combustion engine, the electric generator is operated as a motor to assist the output of the internal combustion engine. When the electric generator does not assist the output of the internal combustion engine, it operates as a generator and charges the battery.

[0003] In the hybrid working vehicle of Patent Document 1, the internal combustion engine supplies driving force to the travel device and the working device via the power transmission unit. The output of the internal combustion engine is assisted by the power output from the motor generator to the power transmission unit.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-65349 Summary of the invention

[0007] In the structure for driving the travel device and the working device by means of the power transmission unit, the driving speed of the travel device and the driving speed of the working device are linked. In this structure, for example, even when the travel wheels slip, the working device operates at a speed that is linked to the driving speed of the travel device regardless of the slip. Therefore, for example, when the working device is a planting device, the planting interval becomes shorter than the target interval due to the slip.

[0008] An object of the present invention is to provide a farm working machine capable of appropriately driving a working device and assisting travel.

[0009] The field working machine shown as an example of the present invention comprises: a traveling body having a traveling device; a working device supported by the traveling body; a prime mover that supplies driving force to the traveling device; a first rotating motor that is connected to the output shaft of the prime mover in a manner capable of transmitting power; and a second rotating motor that supplies driving force to the working device.

[0010] Effects of the Invention

[0011] According to the present invention described as an example, it is possible to appropriately perform driving and travel assistance of the working device of the farmland working machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1This is a diagram showing a basic structure of a farmland working machine.

[0013] Figure 2 It is shown Figure 1 FIG. 2 is a diagram showing a modified example of the basic structure of the farmland working machine shown.

[0014] Figure 3 It is a side view which shows the schematic structure of a rice transplanter.

[0015] Figure 4 It is a top view which shows the schematic structure of a rice transplanter.

[0016] Figure 5 It is a top view which shows the schematic structure of the power transmission mechanism with which the rice transplanter is equipped.

[0017] Figure 6 This is a diagram showing a schematic configuration of a control system for a farm working machine.

[0018] Figure 7 1 is a flowchart showing an example of the control operation of the motor generator by the control device.

[0019] Figure 8 This is a flowchart illustrating the flow of processing executed by the control device to obtain the traveling load.

[0020] Fig. 9 This is a diagram for explaining an example of calculation of the traveling load using the load calculation map.

[0021] Fig.10 It is used to Figure 8 A diagram for explaining the rotation speed correction performed by the processing shown.

[0022] Fig.11 It is shown Figure 7 Flowchart of a modified example of the control action of the control device described in .

[0023] Fig.12 This is a block diagram showing a schematic configuration of a system for controlling the rotation of an engine included in a farmland working machine.

[0024] Fig.13 This is a diagram for explaining the rotation control of the engine of the field working machine having the travel assist function.

[0025] Fig.14 This is a diagram for explaining the rotation control of the engine of the field working machine having the travel assist function.

[0026] Fig.15A This is a flowchart illustrating the flow of engine rotation control executed by the control device.

[0027] Fig. 15B This is a flowchart illustrating the flow of engine rotation control executed by the control device.

[0028] Fig.16 This is a block diagram showing a modified example of a system for performing engine rotation control.

[0029] Fig.17 This is a diagram showing an example of the operation of the farm working machine in the field.

[0030] Fig.18 This is a graph showing the change over time of the remaining capacity of the storage battery when the power generation control is performed according to the present embodiment.

[0031] Description of Reference Numerals

[0032] 1…traveling body; 2…working device; 2A…planting device (working device); 3…engine (prime mover); 4…electric generator (first rotating motor); 5…motor (second rotating motor); 6…battery; 9…switching mechanism; 11…body frame; 12…traveling device; 12a, 12b…wheels; 41…control device; 61…continuously variable transmission; 62a…differential locking unit; 74…straight path; 75…turning path; 100, 100A…field working machine; 100R…rice transplanter (field working machine). DETAILED DESCRIPTION

[0033] Embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in the drawings, and the description thereof will not be repeated.

[0034] In this specification, the term “rotating electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor generator that functions as both a motor and a generator as necessary.

[0035] <1. Basic structure of field work machine>

[0036] Figure 1 1 is a diagram showing a basic structure (basic structure) of a field working machine 100 according to an embodiment of the present invention. Figure 1 In the figure, the thick solid lines connecting the elements represent the power lines. In addition, the thick dotted lines connecting the elements represent the signal lines. In addition, the white arrows represent the direction of power transmission. In the attached figure, the "F" representing the direction is the front side, "B" is the back side, "L" is the left side, and "R" is the right side. This point is Figure 1 The same is true for the other figures except Figure 1 The direction "U" which does not exist in the figure but is recorded in other drawings is the upper side, and "D" is the lower side.

[0037] The field working machine 100 widely includes a working machine that performs work while traveling in a field. The field working machine 100 may be, for example, a rice transplanter, a tractor, a combine harvester, a seed drill, a transplanter, or a liquid pesticide spreader. Figure 1 As shown, the farmland working machine 100 includes a traveling machine body 1 , a working device 2 , a prime mover 3 , a first rotating electric machine 4 , a second rotating electric machine 5 , and a battery 6 .

[0038] The traveling machine body 1 enables the field working machine 100 to travel in the field. The traveling machine body 1 has a machine frame 11 and a traveling device 12. The machine frame 11 constitutes the skeleton of the field working machine 100. The traveling device 12 supports the machine frame 11 so that it can travel. The traveling device 12 is constituted by, for example, wheels and tracks. In addition, in the present embodiment, the traveling device 12 is constituted by a pair of left and right front wheels 12a and a pair of left and right rear wheels 12b.

[0039] The working device 2 is supported on the machine frame 11. In other words, the working device 2 is supported on the traveling machine 1. In addition, in the present specification, supported on the machine frame 11 (traveling machine 1) includes both the case of a structure directly supported on the machine frame 11 (traveling machine 1) and a structure indirectly supported on the machine frame 11 (traveling machine 1). The working device 2 can be supported on the machine frame 11 in a movable manner (for example, rotatable, etc.). The working device 2 is, for example, a planting device, a harvesting device, a tilling device, a fertilizing device, a mowing device, or a sowing device. In addition, in the present embodiment, the working device 2 is arranged at the rear of the machine frame 11, but this is an example, and the working device 2 may also be arranged in front of or on the side of the machine frame 11.

[0040] The prime mover 3 is supported on the body frame 11. The prime mover 3 supplies driving force to the travel device 12. In the present embodiment, as a preferred mode, the prime mover 3 is an engine. Hereinafter, the prime mover 3 is described as its representative example, namely the engine 3. The engine 3 is, for example, a diesel engine, a gasoline engine, a hydrogen engine or a gas engine. The output of the engine 3 is transmitted to the travel device 12 by means of a transmission not shown in the figure. However, the transmission is not an indispensable structure. In addition, the drive control of the engine 3 is performed by a control device not shown in the figure.

[0041] In addition, Figure 1In the embodiment, the output of the engine 3 is transmitted to only one wheel (the left front wheel 12a), but this is just for the convenience of recording. In the present embodiment, the output of the engine 3 is transmitted to the left and right front wheels 12a and the rear wheels 12b. However, the output of the engine 3 may be transmitted to only the left and right front wheels 12a or the left and right rear wheels 12b. In addition, in the present embodiment, the output of the engine 3 is sometimes output to the first rotating motor 4. This will be described later.

[0042] The first rotating motor 4 is supported on the machine frame 11. The first rotating motor 4 is connected to the output shaft of the engine 3 in a manner capable of transmitting power. In detail, the first rotating motor 4 is connected to the engine 3 by means of a power transmission unit not shown in the figure. The power transmission unit widely includes a structure capable of transmitting power. The power transmission unit may be a structure that directly or indirectly connects the output shaft of the engine 3 to the rotating shaft of the first rotating motor 4. The power transmission unit may also be a structure that connects the output shaft of the engine 3 to the rotating shaft of the first rotating motor 4 by means of a power transmission shaft, or a structure that connects the output shaft of the engine 3 to the rotating shaft of the first rotating motor 4 by means of a speed change device. In addition, the first rotating motor 4 can switch the power transmission state between the first rotating motor 4 and the engine 3 to either a connected state or a disconnected state by means of a clutch.

[0043] The first rotating electric machine 4 may be a structure that imparts power to the output of the engine 3. That is, the first rotating electric machine 4 may be a structure that functions as a motor and assists the output of the engine 3. In addition, the first rotating electric machine 4 may be a structure that rotates using the output of the engine 3 and generates electricity. In other words, the first rotating electric machine 4 may be a structure that functions as a generator using the output of the engine 3. In addition, the first rotating electric machine 4 may be a structure that has the two functions described above. That is, the first rotating electric machine 4 may be a structure that has both the functions of functioning as a motor to assist the output of the engine 3 and rotating using the output of the engine 3 and functioning as a generator.

[0044] In the present embodiment, as a preferred mode, the first rotating electric machine 4 is an electric generator. That is, the first rotating electric machine 4 can play both the function of assisting the output of the engine 3 as a motor, and the function of generating electricity by rotating and generating electricity using the output of the engine 3. Hereinafter, the first rotating electric machine 4 will be described as its representative example, namely the electric generator 4. In detail, the electric generator 4 functions as a three-phase AC motor using the input of three-phase AC power, and rotates and functions as a three-phase AC generator by the input of power. By providing the electric generator 4, the output of the engine 3 to the travel device 12 (wheels) can be assisted. In addition, the electric generator 4 is controlled by means of the first inverter 7a and by a control device not shown in the figure.

[0045] The second rotary motor 5 is supported by the machine frame 11. The second rotary motor 5 supplies driving force to the working device 2. That is, in the present embodiment, power is transmitted to the working device 2 from a power source provided separately from the engine 3. According to this structure, the working device 2 can be driven without being affected by changes in the load on the engine 3.

[0046] In the present embodiment, as a preferred mode, the second rotating motor 5 is a motor. Hereinafter, the second rotating motor 5 is described as a representative example thereof, namely, the motor 5. Specifically, the motor 5 is a three-phase AC motor driven by three-phase AC power. In addition, the motor 5 is controlled by the second inverter 7b and by a control device not shown.

[0047] The battery 6 is supported by the machine frame 11. The battery 6 is, for example, a secondary battery composed of a lithium ion battery and capable of charging and discharging. In the present embodiment, the battery 6 is electrically connected to the electric generator 4 and the motor 5. Specifically, the battery 6 is electrically connected to the electric generator 4 via the first inverter 7a. In addition, the battery 6 is electrically connected to the motor 5 via the second inverter 7b.

[0048] The battery 6 can supply electric power to the motor generator 4 via the first inverter 7a. The motor generator 4 can supply electric power to the battery 6 via the first inverter 7a. That is, the motor generator 4 can charge the battery 6. The battery 6 can supply electric power to the motor 5 via the second inverter 7b.

[0049] In detail, the first inverter 7a converts the DC power output from the battery 6 into AC power and supplies it to the motor generator 4. In addition, the first inverter 7a converts the AC power output from the motor generator 4 into DC power and supplies it to the battery 6. The second inverter 7b converts the DC power output from the battery 6 into AC power and supplies it to the motor 5. In addition, the inverters 7a and 7b may be provided or not provided depending on the type of the motor generator and the motor (for example, AC type, DC type). In addition, in the present embodiment, a structure is formed in which inverters are provided for the motor generator 4 and the motor 5 respectively, but a structure may also be formed in which one inverter is shared by the motor generator 4 and the motor 5.

[0050] In the present embodiment, the battery 6 and the first inverter 7a (motor generator 4) are configured to be switchable between an electrically connected state and an electrically disconnected state. In addition, the battery 6 and the second inverter 7b (motor 5) are configured to be switchable between an electrically connected state and an electrically disconnected state. The above switching is achieved by using a relay (not shown) provided in the junction box 8.

[0051] In addition, in the present embodiment, a relay not shown in the figure is arranged between the first inverter 7a and the second inverter 7b, which can switch between the state where the current flows and the state where the current does not flow. In other words, the electric generator 4 and the motor 5 are set to be able to switch between the state of being electrically connected and the state of being not electrically connected. This switching is also achieved by using a relay not shown in the figure in the junction box 8. By electrically connecting the electric generator 4 and the motor 5, the electric power generated by the electric generator 4 can be supplied to the motor 5.

[0052] The motor 5 may be driven by supplying power from the battery 6 or by supplying power from the motor generator 4. Furthermore, the motor 5 may be driven by supplying power from both the battery 6 and the motor generator 4. The motor generator 4 may charge the battery 6 and supply power to the motor 5. The battery 6 may supply power to the motor generator 4 and the motor 5 at the same time.

[0053] In addition, in order to facilitate the arrangement and protection of the wiring, it is preferable to provide the junction box 8, but it is not necessary to provide the junction box 8. It is also possible to adopt a configuration in which the relay wiring is provided separately without providing the junction box 8.

[0054] The field working machine 100 having the basic structure described above performs the following actions, for example. When traveling in a field, the engine 3 usually supplies driving force to the traveling device 12 and supplies driving force for driving the electric generator 4 as a generator. Furthermore, if the travel load, which is a load applied to the engine 3 during travel, increases and a danger such as engine stalling is detected, the electric generator 4 stops generating power, and the output of the engine 3 used for power generation is used as the driving force for traveling. In the case where it is determined that the increase in the travel load cannot be adequately dealt with by simply stopping power generation, the electric generator 4 is made to function as a motor to assist the output of the engine 3 and compensate for the increase in the travel load.

[0055] Furthermore, instead of simply turning on or off the power generation function, a configuration may be adopted in which the amount of power generated by the motor generator 4 is increased or decreased according to the travel load.

[0056] The running load can be obtained based on control information of the engine 3 and detection information of various sensors. The running load can be obtained based on, for example, the rotation speed of the output shaft of the engine 3, the engine torque, the vehicle speed, the fuel injection amount, etc. An example of a method for obtaining the running load is described below.

[0057] Figure 2 It is shown Figure 1 FIG. 2 is a diagram showing a modified example of the basic structure of the farmland working machine 100 shown in FIG. Figure 2The farmland working machine 100A of the modified example shown has Figure 1 The farmland working machines 100 shown have substantially the same structure. The description of the same structure parts will be omitted, and the description will be focused on the different parts.

[0058] like Figure 2 As shown, the farmland working machine 100A of the modification example includes a switching mechanism 9 for switching the power transmission state between the motor generator 4 and the motor 5 to either a connected state or a disconnected state. The switching mechanism 9 is a so-called clutch. By providing the switching mechanism 9, for example, the following utilization method can be realized.

[0059] For example, in the event of a malfunction in a system related to the electric drive using the motor 5 (electric related system), the switching mechanism 9 can be connected as an emergency action. As a result, the working device 2 can be driven by the output of the engine 3 instead of the output of the motor 5. In addition, a speed reduction mechanism can be provided between the switching mechanism 9 and the motor 5 as required. Examples of malfunctions in the electric related system include insufficient charging of the battery 6 and a malfunction in the electric related system. Examples of malfunctions in the electric related system include malfunctions or disconnections in the first inverter 7a, the second inverter 7b, the junction box 8, the electric generator 4, the motor 5, the battery 6, or the wiring connected thereto.

[0060] In addition, for example, when it is determined that the increase in the travel load cannot be adequately dealt with by only making the electric generator 4 function as a motor to assist the output of the engine 3, the switching mechanism 9 can be placed in a connected state. As a result, the output of the electric generator 4 (and ultimately the engine 3) can be assisted by the driving force of the motor 5 to deal with the increase in the travel load. In addition, when the driving force of the motor 5 is used to assist the output of the engine 3, it is preferable to stop the driving of the working device 2. Alternatively, it is preferable to assist the output of the engine 3 using the driving force of the motor 5 when the working device 2 is not working.

[0061] <2. Rice transplanter>

[0062] Next, a specific configuration example in the case where the farmland working machine 100 having the above-mentioned basic configuration is a rice transplanter 100R will be described. Figure 3 1 is a side view showing a schematic structure of a rice transplanter 100R according to an embodiment of the present invention. Figure 3 In the figure, in order to facilitate understanding of the structure of a portion that is originally hidden from the rear wheel 12b, the rear wheel 12b is indicated by a virtual line (two-dot chain line). Figure 4 It is a top view which shows the schematic structure of the rice transplanter 100R. Figure 5It is a top view which shows the schematic structure of the power transmission mechanism with which the rice transplanter 100R is equipped.

[0063] In the description of the rice transplanter 100R, the travel plane S (see Figure 3 ) is defined as the up-down direction, and the up-down direction is defined by setting the rice transplanter 100R side as the top relative to the driving plane S. In addition, the direction in which the rice transplanter 100R travels straight is defined as the front-back direction, and the direction relative to the driver's seat 20 (refer to Figure 3 , Figure 4 ) defines the front and rear by setting the steering wheel 21 as the front side. In addition, the direction perpendicular to the up-down direction and the front-back direction is defined as the left-right direction, and the right side is defined as the right and the left side is defined as the left from the back to the front. In addition, the above directions are only names for explanation, and are not intended to limit the actual positional relationship and direction.

[0064] The rice transplanter 100R performs a planting operation of planting rice seedlings on the ground of the field while traveling in the field. Figure 3 and Figure 4 As shown, the rice transplanter 100R includes a traveling body 1 and a working device 2 .

[0065] The traveling machine 1 includes a machine frame 11 and a traveling device 12. The traveling device 12 includes front wheels 12a arranged at intervals in the left-right direction at the front of the machine frame 11. The traveling device 12 includes rear wheels 12b arranged at intervals in the left-right direction at the rear of the machine frame 11. An engine 3 covered from above by an engine cover 13 is arranged at the left-right center of the front of the machine frame 11. Figure 3 and Figure 4 In the figure, the engine 3 is not visible because it is covered by the engine cover 13, so the engine 3 is represented by a virtual line (dashed line). In addition, as mentioned above, the engine 3 is an example of a prime mover, specifically a diesel engine, but it can also be a structure (such as a motor) that replaces the diesel engine. In addition, the position of the engine 3 can be set to a position different from the position of the present embodiment.

[0066] like Figure 3 and Figure 5 As shown, a transmission 15 is arranged behind the engine 3. In addition, the transmission 15 is not an indispensable structure. In the case where the prime mover is composed of a structure that replaces the engine, etc., a structure without a transmission can be formed. The transmission 15 is configured to be able to change the speed of the driving force generated by the engine 3. A front axle 16 is arranged on the left and right sides of the transmission 15. The front wheel 12a is mounted on a front wheel shaft 16a provided on the front axle 16, and is driven by the driving force transmitted from the transmission 15.

[0067] A rear axle 17 is disposed behind the transmission 15. Specifically, the rear axle 17 is coupled to the transmission 15 by a coupling 18 extending in the front-rear direction. A rear-wheel drive shaft 19 is disposed along the coupling 18. The rear-wheel drive shaft 19 transmits a driving force from the transmission 15 to the rear axle 17. The rear wheel 12b is mounted on a rear wheel shaft 17a provided on the rear axle 17. The rear wheel 12b is driven by the driving force transmitted from the transmission 15 via the rear-wheel drive shaft 19.

[0068] In addition, the motor generator 4 is connected to the transmission 15 in a manner capable of transmitting power. In addition, as described above, the motor generator 4 is an example of a first rotating electrical machine. In detail, the motor generator 4 is arranged at the rear of the transmission 15. However, the arrangement of the motor generator 4 is not limited to that of the present embodiment, and can be appropriately changed.

[0069] When the motor generator 4 functions as a motor, it assists the output of the engine 3 via the transmission 15. When the motor generator 4 functions as a generator, it rotates using the driving force from the engine 3 transmitted via the transmission 15 to generate electricity. In addition, in the present embodiment, power transmission is performed so that the rotation speed of the engine 3 is the same as the rotation speed of the motor generator 4. The electric power generated by the motor generator 4 is supplied to at least one of the battery 6 and the motor 5 via the first inverter 7a and the junction box 8.

[0070] As described above, the motor 5 is an example of a second rotating electrical machine. The motor 5 is supported by the machine frame 11 above the rear axle 17. Specifically, the motor 5 is arranged at a position further to the right than the left-right center above the rear axle 17. By arranging the motor 5 in such a position, when working in the field, the possibility of the motor 5 being immersed in water or soiled by mud can be reduced. However, the configuration of the motor 5 is not limited to this and can also be appropriately changed. The motor 5 is supplied with power from at least one of the battery 6 and the electric generator 4 via the junction box 8 and the second inverter 7b.

[0071] In addition, Figures 3 to 5 In the figure, the battery 6, the first inverter 7a, the second inverter 7b and the junction box 8 are not shown, but these components are arranged at appropriate positions of the traveling body 1 (preferably the body frame 11).

[0072] In the present embodiment, the motor generator 4 and the motor 5 are not connected in a power-transmittable manner, but the motor generator 4 and the motor 5 may be connected in a power-transmittable manner via the switching mechanism 9 as in the modified example of the above-mentioned basic structure. Figure 5 The thick dotted line in Schematically shows that the motor generator 4 and the motor 5 are connected via the switching mechanism 9 in a power-transmittable manner.

[0073] The traveling machine body 1 includes a driver's seat 20 supported by a machine body frame 11. The driver's seat 20 is arranged above the joint 18. A steering wheel 21, which is a steering wheel for an operator to steer the rice transplanter 100R, is arranged in front of the driver's seat 20. In addition, operating devices such as a shift lever, a shift pedal, and a brake pedal (not shown) are arranged around the driver's seat 20.

[0074] The traveling body 1 is provided with a preliminary seedling loading platform 22 arranged on the left and right outer sides of the engine cover 13. A seedling raising mat for supplementation is placed on the preliminary seedling loading platform 22. The preliminary seedling loading platform 22 is arranged on the left and right sides, respectively. A plurality of preliminary seedling loading platforms 22 are arranged in the vertical direction on the left and right sides, respectively.

[0075] The working device 2 is supported by the machine frame 11. Specifically, the working device 2 is a planting device 2A. The planting device 2A is supported by the machine frame 11 in a manner that allows it to swing in the up and down directions. The planting device 2A includes: a seedling loading platform 30 on which a seedling mat is loaded; and a main frame 31. The main frame 31 is a rod-shaped member extending in the left-right direction, and is provided with a central box 32 in the center of the left-right direction (see Figure 3 , 5 ).

[0076] The center case 32 is provided with a gear train including bevel gears (not shown). The drive shaft 52 is connected to the input shaft 32a of the center case 32 via a universal joint 51. The end of the drive shaft 52 on the opposite side to the side connected to the input shaft 32a of the center case 32 is connected to the output shaft 5a of the motor 5 via a universal joint 51. The output shaft 5a of the motor 5 extends in the front-rear direction and protrudes to the rear. The output shaft 32b of the center case 32 (see Figure 5 ) is arranged along the main frame 31. That is, the output shaft 32b of the center box 32 extends in the left-right direction.

[0077] In addition, in the present embodiment, the output shaft 5a of the motor 5 is connected to the drive shaft 52, but this is an example. For example, as a structure in which the speed change device is connected to the output shaft 5a of the motor 5, a structure in which the speed change device is connected to the drive shaft 52 may be formed. In addition, a structure in which the output shaft 5a of the motor 5 is directly connected to the center case 32 may be formed.

[0078] The planting transmission box 33 is arranged at multiple locations (four locations as an example) in the left-right direction behind the main frame 31 at approximately equal intervals. The planting transmission box 33 is connected to the output shaft 32b of the central box 32. A pair of planting parts (transplanting mechanisms) 34 are arranged on the left and right sides of the planting transmission box 33.

[0079] A pair of planting parts 34 include a rotor box 35 and a planting claw 36. The rotor box 35 is mounted on the planting transmission box 33 in a manner that allows it to rotate around an axis extending in the left-right direction. Two planting claws 36 arranged on opposite sides of the rotation center of the rotor box 35 are mounted on each rotor box 35 in a manner that allows it to rotate around an axis extending in the left-right direction. The two planting claws 36 are displaced as the rotor box 35 rotates. Planting of one ridge of seedlings is performed by displacing the two planting claws 36.

[0080] The driving force generated by the motor 5 is transmitted to the planting section 34 via the driving shaft 52, the central box 32 and the planting transmission box 33. The planting device 2A is provided with a lateral conveying driving section (not shown) for moving the seedling loading platform 30 in the left-right direction. Each planting section 34 takes out the seedlings from the seedling loading platform 30 in parallel with the left-right direction of the seedling loading platform 30 and plants them in the field. In the present embodiment, there are a plurality of planting sections 34 (specifically, 8), so that planting for multiple ridges can be performed simultaneously.

[0081] In addition, the planting device 2A is provided so as to be able to be raised and lowered by the lifting device 37 (see Figure 3 ). The lifting device 37 includes a column frame 371, an upper link member 372, a lower link member 373 and a hydraulic cylinder 374. The column frame 371 extends upward from the rear axle 17 and is connected to the rear portion of the body frame 11. The upper link member 372 and the lower link member 373 constitute a pair of link members arranged parallel to each other. The column frame 371 and the seedling loading platform 30 are connected by the pair of link members 372 and 373. The nodes of the column frame 371, the seedling loading platform 30 and the pair of link members 372 and 373 constitute the four vertices of a parallelogram.

[0082] The hydraulic cylinder 374 is connected to the joint 18 and the lower link member 373. The pair of link members 372 and 373 are swung with the node on the column frame 371 side as a fulcrum by the extension and contraction of the hydraulic cylinder 374, thereby raising and lowering the planting device 2A. In addition, the hydraulic cylinder is extended and contracted by controlling the drive of a hydraulic pump (not shown) driven by the output from the engine 3.

[0083] In the rice transplanter 100R of the present embodiment, power is transmitted to the planting device 2A (working device 2) from the motor 5, which is a power source independently provided in the power transmission path relative to the engine 3. Therefore, the planting device 2A can be driven without being affected by the change in the load on the engine 3. For example, the rice seedlings can be planted at appropriate intervals without being affected by the slip of the running wheels 12a and 12b. In addition, the rice seedlings can be planted at any intervals without depending on the running speed of the rice transplanter 100R.

[0084] Moreover, about the rice transplanter 100R, the following operation|movement is performed, for example.

[0085] When traveling in a field, the engine 3 usually supplies driving force to the travel device 12, supplies driving force for driving the lifting device 37 to the hydraulic pump, and supplies driving force for driving the motor generator 4 as a generator. In addition, the electric power generated by the motor generator 4 is supplied to at least one of the motor 5 and the battery 6.

[0086] If the danger of engine stalling or the rice transplanter 100R sinking in the field is detected due to the increase in the travel load, the electric generator 4 is stopped from generating electricity, and the output of the engine 3 used for generating electricity is used as the driving force for traveling. In addition, when it is determined that the increase in the travel load cannot be fully dealt with by stopping the power generation, the electric generator 4 is made to function as a motor to assist the output of the engine 3, thereby arranging and supplying the output corresponding to the increase in the travel load. By driving the electric generator 4 as a motor to assist the output of the engine 3, the rice transplanter 100R can be prevented from sinking in a part (muddy part, etc.) with a high travel load in the field, or the sunken rice transplanter 100R can be separated by its own force.

[0087] Moreover, when the rice transplanter 100R is provided with the switching mechanism 9 which switches the power transmission state between the motor generator 4 and the motor 5 to either the connection state or the disconnection state, the rice transplanter 100R can be operated as follows.

[0088] For example, when a malfunction (failure, etc.) occurs in the electric related system driving the planting device 2A, the switching mechanism 9 can be connected as an emergency operation. Thus, the planting device 2A can be driven by the output of the engine 3 instead of the output of the motor 5.

[0089] In addition, for example, when it is determined that the output of the motor generator 4 assisting the engine 3 by only functioning as a motor cannot sufficiently cope with the increase in the travel load, the switching mechanism 9 can be placed in a connected state. Thus, the output of the motor generator 4 (and ultimately the engine 3) can be assisted by the driving force of the motor 5 to cope with the increase in the travel load. In addition, when the driving force of the motor 5 is used to assist the output of the engine 3, it is preferred to stop the driving of the planting device 2A. Alternatively, it is preferred to assist the output of the engine 3 using the driving force of the motor 5 when the planting operation of the planting device 2A is not being performed.

[0090] <3. Control systems for field work machines>

[0091] Figure 61 is a diagram showing a schematic configuration of a control system of a field working machine 100 according to an embodiment of the present invention. Figure 6 As shown, the farmland working machine 100 includes a control device 41 , a storage device 42 , and an operating device 43 .

[0092] The control device 41 is configured to include a computing circuit, a memory, and an input / output unit. The computing circuit is, for example, a processor or a microprocessor. The memory may be the storage device 42 or a device different from the storage device 42. The functions of the control device 41 are realized, for example, by the computing circuit executing computing processing according to a program stored in the memory. The control device 41 is disposed at an appropriate position of the traveling machine body 1 (preferably the machine body frame 11).

[0093] In addition, the control device 41 may be composed of one hardware or a plurality of hardwares that can communicate with each other. The functions of the control device 41 may be realized by a computing circuit that performs computing processing according to a program, i.e., software, as described above, but may also be realized by other methods. At least a portion of the functions of the control device 41 may be realized, for example, using an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or the like. That is, at least a portion of the functions of the control device 41 may be realized by hardware using a dedicated IC, etc. In addition, at least a portion of the functions of the control device 41 may be realized by using both software and hardware.

[0094] The storage device 42 is a main storage device such as ROM (Read Only Memory) and RAM (Random Access Memory). The storage device 42 may also include an auxiliary storage device such as HDD (Hard Disk Drive) or SSD (Solid State Drive). Various programs and data are stored in the storage device 42. For example, the load calculation map 42a described in detail later is stored in the storage device 42. The storage device 42 is arranged at an appropriate position of the traveling machine body 1 (preferably the machine body frame 11).

[0095] The operating device 43 can input control instructions to the control device 41 to the operator of the farm working machine 100. The operating device 43 can be composed of a single device or a plurality of devices. The operating device 43 may include a control device disposed on the driver's seat 20 (see Figure 3 Various rods, pedals, buttons, etc.

[0096] like Figure 6As shown, the control device 41 controls the engine ECU (Electronic Control Unit) 1a. Under the control of the control device 41, the engine ECU 1a performs electronic control for injecting fuel to the engine at an appropriate timing and in an optimal amount. The control device 41 obtains various information related to the engine from the engine ECU 1a. In addition, the engine ECU 1a is arranged at an appropriate position of the traveling machine body 1 (preferably the machine body frame 11). In addition, the control device 41 may have the functions of the engine ECU 1a, in which case, the engine ECU 1a is not required.

[0097] In addition, the control device 41 controls the first inverter 7a and the second inverter 7b. That is, the first inverter 7a controls the operation of the electric generator 4 under the control of the control device 41. The second inverter 7b controls the operation of the motor 5 under the control of the control device 41. The control device 41 obtains information related to the electric generator 4 and the motor 5 through the first inverter 7a and the second inverter 7b.

[0098] In addition, the control device 41 controls the battery management system (BMS: Battery Management System) 6a. The BMS 6a is configured as a control circuit, and monitors and controls the charging and discharging of the battery 6 under the control of the control device 41. The control device 41 obtains information related to the battery through the BMS 6a. In addition, the BMS 6a is configured at an appropriate position of the traveling machine body 1 (preferably the machine body frame 11).

[0099] In addition, the control device 41 controls the junction box 8 (see Figure 1 ) is used to control the operation of the relay 8a included in the control device 41. In the present embodiment, the number of relays 8a controlled by the control device 41 is multiple.

[0100] Figure 7 4 is a flowchart showing an example of the control operation of the control device 41 on the motor generator 4. Figure 7 Action shown.

[0101] In step S1, the control device 41 obtains the load applied to the engine 3 during driving, that is, the driving load. As described above, the driving load can be obtained based on the control information of the engine 3 and the detection information of various sensors. An example of a method for obtaining the driving load is described later. In addition, it is also possible to obtain an index value instead of the driving load itself. According to the processing content described below, with respect to the field working machine 100, the operating state of the electric generator 4 is changed according to the load applied to the engine 3 during driving, that is, the driving load or the index value of the driving load. As a result, the electric generator 4 can perform actions appropriately according to the situation, and the driving state of the field working machine 100 can be improved and the energy efficiency can be improved. If the driving load is obtained, the processing enters the next step S2.

[0102] In step S2, the control device 41 determines whether the acquired travel load is less than a preset first threshold value. If the travel load is less than the first threshold value (Yes in step S2), the process proceeds to the next step S3. If the travel load is greater than the first threshold value (No in step S2), the process proceeds to step S5.

[0103] In step S3, the control device 41 issues a power generation command to the first inverter 7a. This is because, based on the relationship between the travel load and the first threshold, it can be estimated that the load applied to the engine 3 is not large and there is a margin for using the output of the engine 3 for power generation. The first threshold is set to enable such an estimation. According to the control action of the first inverter 7a corresponding to the power generation command, the electric generator 4 is rotated by the driving force from the engine 3 to generate electricity. For example, when the working device 2 performs work, the generated power is supplied to the second inverter 7b and used to drive the motor 5. In addition, when there is no need to supply power to the motor 5 for reasons such as the working device 2 not working, the generated power is used to charge the battery 6. In addition, when the battery 6 is in a fully charged state and there is no need to supply power to the battery 6, the power generation command can be released and the power generation function of the electric generator 4 can be stopped. If the control device 41 issues a power generation command, the process enters the next step S4.

[0104] In step S4, the control device 41 determines whether there is a control termination reason. As the case where there is a control termination reason, for example, there is a driving stop instruction based on the operator, and the engine is turned off. If there is a control termination reason (Yes in step S4), the control device 41 terminates. Figure 7 If there is no control end reason (No in step S4), the process returns to step S1, and the process after step S1 is executed again.

[0105] In step S5, the control device 41 determines whether the travel load greater than the first threshold is less than a preset second threshold. In addition, the second threshold is greater than the first threshold. When the travel load is less than the second threshold (Yes in step S5), the process proceeds to the next step S6. When the travel load reaches or exceeds the second threshold (No in step S5), the process proceeds to step S7.

[0106] In step S6, the control device 41 issues a power generation stop command to the first inverter 7a. This is because, based on the relationship between the driving load and the first threshold and the second threshold, it is estimated that the load applied to the engine 3 has increased to a certain extent and there is no surplus of the output of the engine 3 for power generation. The first threshold and the second threshold are set to enable such an estimation. The electric generator 4 stops generating electricity through the control action of the first inverter 7a corresponding to the power generation stop command. If the power generation stop command based on the control device 41 is issued, the processing enters step S4. Thereafter, as described above, when there is a reason for the control to end, the control ends. Figure 7 In the control flow shown, when there is no control end event, the process returns to step S1.

[0107] In step S7, the control device 41 issues an assist command to the first inverter 7a. This is because, based on the relationship between the driving load and the second threshold, it is estimated that the load applied to the engine 3 is large and there is a risk of engine stalling. The second threshold is set to enable such an inference. Through the control action of the first inverter 7a corresponding to the assist command, the electric generator 4 functions as a motor to assist the output of the engine 3. If the assist command is issued, the process enters step S4. Thereafter, as described above, when there is a reason for the control to end, the control ends. Figure 7 In the control flow shown, when there is no control end event, the process returns to step S1.

[0108] As can be seen from the above description, if the running load or the index value of the running load reaches or exceeds the first threshold value, the electric generator 4 stops generating electricity. As a result, the engine 3 can use the output of the amount used for power generation for running. In addition, if the running load or the index value of the running load reaches or exceeds the second threshold value greater than the first threshold value, the electric generator 4 assists the output of the engine 3. As a result, in the case where the output is insufficient by using the output for power generation for running, the output of the electric generator 4 can be used to supply the insufficient output.

[0109] As in the present embodiment, by switching the operation of the motor generator 4 in stages, it is possible to improve the energy utilization efficiency and enable the farm working machine 100 to travel appropriately. However, when it is determined that the load of the engine 3 during travel is high, the power generation function of the motor generator 4 may be stopped and the motor generator 4 may be immediately made to function as a motor to assist the output of the engine 3.

[0110] Figure 8 2 is a flowchart illustrating the flow of processing executed by the control device 41 to acquire the travel load. Figure 8 yes Figure 7 A specific example of the processing of step S1.

[0111] In step S11, the control device 41 detects the current throttle opening. The throttle opening can be detected, for example, by a potential sensor that detects the position of a lever that controls the rotation of the engine 3. When the current throttle opening is detected, the process proceeds to the next step S12.

[0112] In step S12, the control device 41 detects the current engine speed. The current engine speed of the engine 3 can be obtained, for example, based on the speed of the motor generator 4. The speed of the motor generator 4 can be detected by using a rotation sensor provided in the motor generator 4. The control device 41 can obtain the detection value of the rotation sensor by means of the first inverter 7a. If the current engine speed is detected, the process proceeds to the next step S13. In addition, the processing order of the processing of step S11 and the processing of step S12 can be reversed, or the processing can be performed in parallel.

[0113] In step S13, the control device 41 reads the load calculation map 42a from the storage device 42. The load calculation map 42a is a map for calculating the travel load, and in this embodiment, it is a map (curve graph) representing the characteristics of the engine 3. The characteristics of the engine 3 are so-called cyclic speed regulation characteristics. If the load calculation map 42a is read, the processing enters the next step S14. In addition, the processing of step S13 can be performed before the processing of step S11, and the processing of step S11 and step S12 can also be performed in parallel.

[0114] In step S14, the control device 41 determines whether driving assistance is being performed using the electric generator 4. For example, it can be determined whether driving assistance is being performed based on the history of control commands for the electric generator 4. If driving assistance is not being performed (No in step S14), the process proceeds to the next step S15. If driving assistance is being performed (Yes in step S14), the process proceeds to step S16.

[0115] In step S15, the control device 41 calculates the travel load using the previously acquired current throttle opening, current engine speed, and load calculation map 42a. Fig. 9 An example of calculation of the travel load will be described.

[0116] Fig. 9 4 is a diagram for explaining an example of calculation of the traveling load using the load calculation map 42a. In this example, the load calculation map 42a is a graph showing engine characteristics. Fig. 9 The horizontal axis of the graph shown in is the rotation speed, and the vertical axis is the torque. In this graph, a straight line representing the relationship between the rotation speed and the torque is formed for each throttle opening (shown as a percentage in the figure). In addition, the single-point dashed line in the graph represents the torque limit value.

[0117] Here, the throttle opening obtained by the processing of step S1 is set to 60%. In this case, in the curve diagram representing the engine characteristics, a straight line with a throttle opening of 60% (a straight line representing the relationship between the speed and the torque) is used. On this straight line, the speed X1 at which the torque is zero is the current target engine speed. However, due to the existence of the driving load, the current engine speed becomes a speed R1 that is less than the engine target speed X1. The speed at which the driving load is maximum when the throttle opening is 60% is assumed to be the speed X2 at which the straight line with a throttle opening of 60% intersects with the torque limit value. It can be assumed that the load factor of the driving load is 0% at the speed X1 and the load factor of the driving load is 100% at the speed X2. Therefore, the current driving load (load factor) can be calculated by using the following calculation formula (1) using proportional distribution.

[0118] Driving load (load rate) = (X1-R1) / (X1-X2)*100(1)

[0119] The driving load thus acquired is used to control the operation of the motor generator 4 (see the above Figure 7 ). In addition, as described above, instead of calculating the driving load, an index value of the driving load may be used. For example, the difference between the current engine target speed and the actual engine speed may be used as an index value of the driving load. In addition, a configuration may be formed such that the driving load is used for controlling the operation of the motor generator 4 and the operator is notified. This can assist the operator's driving operation in the case of manual operation.

[0120] In step S16, the control device 41 corrects the current engine speed. This is because the speed of the motor generator 4 acquired by the control device 41 via the first inverter 7a is different from the speed originally output by the engine 3 because the motor generator 4 is used for driving assistance. Fig.10 An example of rotation speed correction will be described.

[0121] Fig.10 It is used to Figure 8 A diagram for explaining the rotation speed correction performed by the processing shown. Fig.10 It is intercepted Fig. 9 A part of the image is enlarged and elements necessary for explaining the correction are added. Fig.10 In the description, the accelerator opening is also set to 60%. Figure 8 The current engine speed R1 obtained in step S12 is the speed obtained by adding the speed xa to the speed R2 originally output by the engine 3. Figure 8 The current engine speed R1 obtained in step S12 is corrected.

[0122] The torque (assist torque Y) output by the motor generator 4 for assisting is obtained from the first inverter 7a. Figure 8 The current engine speed R1 obtained in step S12 is subtracted from the speed corresponding to the assist torque Y obtained from the straight line representing the relationship between the speed and the torque when the accelerator opening is 60% (in Fig.10 In the example shown, this corresponds to the rotation speed xa), and thereby the rotation speed R2 originally output by the engine 3 (corrected rotation speed R2) can be obtained.

[0123] When the corrected rotation speed R2 is obtained, the process proceeds to step S15, and the current running load (load rate) when the running assist is performed can be calculated by the following equation (2) using the corrected rotation speed R2 obtained in step S16.

[0124] Driving load (load rate) = (X1-R2) / (X1-X2)*100(2)

[0125] Next, a modification of the control operation of the control device 41 will be described. Fig.11 It is shown Figure 7 Flowchart of a modified example of the control operation of the control device 41 described above. Figure 7 In the embodiment, it is assumed that there is no switching mechanism 9 for switching the power transmission state between the electric generator 4 and the motor 5 (see Figure 2 ) situation. Fig.11 In FIG. 4 , a case where a switching mechanism (clutch) 9 controlled by the control device 41 is present is assumed.

[0126] Fig.11 The flowchart shown is similar to Figure 7 The flowchart shown is roughly the same. However, Fig.11 In the flowchart shown, relative to Figure 7The flowchart shown in the figure has the process of step S7A and the process of step S8 added. The following description will focus on the added parts.

[0127] In this modification, when the travel load reaches or exceeds the second threshold value (No in step S5), the process does not proceed to step S7 but to step S7A. In step S7A, the control device 41 determines whether the travel load greater than the second threshold value is less than a third threshold value set in advance. In addition, the third threshold value is greater than the second threshold value. When the travel load is less than the third threshold value (Yes in step S7A), the process proceeds to step S7. In step S7, Figure 7 Similarly, an assist command is issued to the motor generator 4, thereby assisting the output of the engine 3 by the motor generator 4. When the running load is equal to or greater than the third threshold value (No in step S7A), the process proceeds to step S8.

[0128] In step S8, the control device 41 issues an assist instruction to the first inverter 7a and the second inverter 7b. This is because, based on the relationship between the driving load and the third threshold value, it is estimated that the load applied to the engine 3 is very large, and there is a risk of engine stalling, etc., with the assistance of the electric generator 4 alone. The third threshold value is set to enable such an inference. Through the control action of the first inverter 7a corresponding to the assist instruction, the electric generator 4 assists the output of the engine 3. In addition, through the control action of the second inverter 7b corresponding to the assist instruction, the motor 5 assists the output of the electric generator 4. In other words, the output of the engine 3 is assisted by both the electric generator 4 and the motor 5. In addition, when the motor 5 is used to assist the output of the electric generator 4, the switching mechanism 9 is placed in a connected state. Thereafter, the processing enters step S4, and Figure 7 Same as the situation, if there is a reason for the end of control, the end Fig.11 In the control flow shown, when there is no control end event, the process returns to step S1.

[0129] Furthermore, when the assist command is issued to the second inverter 7b, the driving of the working device 2 is stopped when the working device 2 is driven. Alternatively, the following configuration may be adopted: the assist command is issued to the second inverter 7b only when the driving of the working device 2 is stopped. Furthermore, after the motor 5 starts assisting the output of the engine 3 by the processing of step S8, when the processing after step S1 is performed and it is determined that the travel load is less than the third threshold value, the assist of the motor 5 is stopped. In this case, the driving of the working device 2 using the motor 5 can be appropriately started.

[0130] As can be seen from the above description, in this modification, if the travel load or the index value of the travel load reaches or exceeds the third threshold value that is greater than the second threshold value, the switching mechanism 9 is connected, and the motor 5 does not supply driving force to the working device 2 but assists the output of the electric generator 4. As a result, it is possible to increase the force that assists the output of the engine 3. According to this, for example, even if the field working machine 100 is about to sink into a muddy part of the field, a large assist force can be obtained to avoid sinking.

[0131] <4. Engine rotation control>

[0132] Next, a detailed example of the rotation control of the engine 3 configured to assist the electric generator 4 will be described. In addition, the rotation control of the engine 3 described below can be applied to a system that uses a motor instead of the electric generator 4. In addition, the following structure can be used: the engine 3 supplies power to the working device 2 via a PTO (Power-take-off) shaft. In this case, the field working machine 100 does not need to include the second rotating electric machine (motor) 5.

[0133] Fig.12 1 is a block diagram showing a schematic configuration of a system for controlling the rotation of the engine 3 included in the farmland working machine 100. Fig.12 The solid arrows shown represent control flow and the white arrows represent power flow.

[0134] like Fig.12 As shown, the farm working machine 100 includes a continuously variable transmission 61 that changes the speed of the power from the engine 3 and outputs it to the travel device 12. The continuously variable transmission 61 may be, for example, a hydraulic transmission, and more specifically, may be an HST (Hydraulic Static Transmission) or an HMT (Hydro Mechanical Transmission). In addition, the continuously variable transmission 61 may be a mechanical transmission instead of a hydraulic transmission.

[0135] Specifically, the power after the speed change by the continuously variable transmission device 61 is transmitted to the travel device 12 by means of the power transmission element included in the transmission 62. The transmission 62 includes a travel speed change gear mechanism, a differential mechanism, etc. In addition, in the case of a structure in which the power of the engine 3 is supplied to the working device 2 by means of a PTO shaft, the transmission 62 may include a PTO speed change mechanism for appropriately changing the rotation speed of the PTO shaft.

[0136] like Fig.12As shown, the control device 41 includes an assist control unit 41a, an acceleration control unit 41b, and a speed control unit 41c as its functions. As described above, the functions of the functional units 41a to 41c can be implemented by software or hardware. In addition, the functions of the functional units 41a to 41c can be implemented by a combination of software and hardware.

[0137] The assist control unit 41a controls the motor generator 4 via the first inverter 7a to change the assist state of the motor generator 4 to the output of the engine 3. The acceleration control unit 41b controls the engine 3 via the engine ECU 1a to increase or decrease the rotation speed of the engine 3. The speed change control unit 41c controls the continuously variable transmission 61 to change the travel speed (vehicle speed) of the farm working machine 100. That is, the farm working machine 100 includes a control device 41 that controls the engine 3, the motor generator (first rotating electrical machine) 4, and the continuously variable transmission 61.

[0138] In the present embodiment, the speed control unit 41c calculates the target speed of the engine 3 based on the operation amount of a speed change operating member (not shown) such as a speed change pedal. Figure 6 ) may include a speed change operating member. The acceleration control unit 41b controls the speed of the engine 3 so that it reaches the target speed calculated by the speed change control unit 41c. If it is formed into such a structure, the operator of the field working machine 100 can obtain the appropriate speed of the engine 3 corresponding to it only by operating the speed change operating member.

[0139] In the farm working machine 100 of this embodiment, when a deviation occurs between the target speed and the actual speed of the engine 3 due to the load during field travel, the motor generator 4 assists the output of the engine 3 (travel assistance). The rotation control of the engine 3 in consideration of the travel assistance is described below with reference to a specific example. Fig.13 and Fig.14 This is a diagram for explaining the rotation control of the engine 3 of the farm working machine 100 having the travel assist function. Fig.13 It is a diagram showing an example in which the engine 3 is restarted by the driving assist. Fig.14 This is a diagram showing an example in which the engine 3 is restarted without driving assistance.

[0140] In addition, Fig.13 and Fig.14 In the example, the “target speed” is the target speed of the engine 3. As described above, the target speed of the engine 3 is determined according to the operation amount of the speed change operation member. Fig.13 and Fig.14In the above, the “actual speed” is the actual speed of the engine 3, and the control device 41 can appropriately obtain the actual speed of the engine 3 from the engine ECU 1a or the like, for example. Fig.13 and Fig.14 In the figure, the “speed ratio” is the speed transmission ratio of the continuously variable transmission device 61, which can be replaced by the travel speed (vehicle speed) of the farm working machine 100. Fig.13 and Fig.14 In , "assist torque" indicates the magnitude of torque when the motor generator 4 assists the output of the engine 3 (assistance based on the motor function: driving assist). In addition, the speed difference between the target speed and the actual speed of the engine 3 can be called an index value of the driving load.

[0141] First, refer to Fig.13 The case where the engine 3 is restored to rotate by the driving assist is described below. Fig.13 In the example shown, at time t1, the driving load increases, and the actual speed of the engine 3 begins to deviate from the target speed. Moreover, at time t2, the actual speed of the engine 3 deviates from the target speed by a predetermined speed difference (first threshold TH1). In addition, at the time point of time t1, driving assistance is not performed, and the assist torque is zero.

[0142] At time t2, driving assistance using the electric generator 4 is started. That is, the control device 41 detects the speed difference between the target speed and the actual speed of the engine 3, and when the speed difference reaches a predetermined speed difference (first threshold value TH1 in this example) or more, the electric generator (first rotating electric machine) 4 assists the output of the engine 3. When the load of the engine 3 increases and the speed of the engine 3 decreases, driving assistance is automatically started, so the operator can avoid engine stalling without performing special operations.

[0143] In addition, preferably, the magnitude of the assist torque during driving assistance is determined according to the magnitude of the speed difference between the target speed and the actual speed of the engine 3. However, the magnitude of the assist torque during driving assistance may also be a predetermined amount. In addition, as described below, preferably, the magnitude of the assist torque during driving assistance is increased in stages.

[0144] In addition, in the present embodiment, at time t2, the target speed of the engine 3 is increased. That is, when the speed difference between the target speed and the actual speed of the engine 3 reaches a predetermined speed difference or more, the control device 41 increases the target speed of the engine 3 and performs driving assistance. By configuring in this way, the possibility of increasing the actual speed of the engine 3 can be increased. In addition, by forming a structure that increases the target speed of the engine 3 to the maximum limit, the reduction amount of the actual speed relative to the target speed (in other words, the driving load) can be detected with good reproducibility. As a result, the auxiliary torque determined according to the size of the speed difference between the target speed and the actual speed of the engine 3 can be appropriately determined. In addition, according to this viewpoint, in detail, when the speed difference between the target speed and the actual speed of the engine 3 reaches a predetermined speed difference or more, it is preferred to start driving assistance after increasing the target speed of the engine 3.

[0145] exist Fig.13 In the example shown, at time t3 when a predetermined time T1 has passed after the start of driving assistance (which may also be referred to as the increase timing of the auxiliary torque), the speed ratio of the continuously variable transmission 61 is reduced. The driving speed of the field working machine 100 is reduced due to the reduction in the speed ratio of the continuously variable transmission 61. That is, when the speed difference between the target speed and the actual speed of the engine 3 reaches or exceeds the predetermined speed difference, the control device 41 performs a reduction in the driving speed based on the change in the speed ratio of the continuously variable transmission 61. By configuring in this way, the driving load itself can be reduced, and the excessive torque burden on the electric generator 4 that performs driving assistance can be suppressed. In addition, by reducing the driving load itself, the possibility of eliminating the deviation between the target speed and the actual speed can be increased.

[0146] In the present embodiment, as a preferred structure, the control device 41 performs a change in the speed ratio of the continuously variable transmission 61 after starting the assistance (driving assistance). The start of driving assistance and the change (reduction) of the speed ratio can be performed at the same timing. However, in the case of a structure in which the speed ratio of the continuously variable transmission 61 is changed after starting the driving assistance as in the present embodiment, when the deviation between the target speed and the actual speed of the engine 3 can be eliminated only by driving assistance, the speed ratio of the continuously variable transmission 61 does not need to be changed. That is, the driving speed of the field working machine 100 does not need to be reduced arbitrarily.

[0147] The amount of change in the speed ratio of the continuously variable transmission 61 may be determined, for example, based on the magnitude of the speed difference between the target speed and the actual speed of the engine 3 , or may be a predetermined amount.

[0148] As with the case of the assist torque, the speed ratio of the continuously variable transmission 61 is preferably changed in stages. Fig.13In the example shown, the control device 41 performs driving assistance and speed ratio changes in stages. Even if the assist torque during driving assistance and the speed of the field working machine 100 are only slightly reduced, the deviation between the target speed of the engine 3 and the actual speed can be eliminated. Therefore, by performing driving assistance in stages, the burden imposed on the electric generator 4 during driving assistance can be minimized, and the power consumption of the battery 6 can be minimized. In addition, by performing the speed ratio change of the continuously variable transmission 61 in stages, the speed of the field working machine 100 can be minimized. In addition, when working in the field where the driving load is easy to change and it is difficult to judge to what extent the speed ratio can be reduced, the speed ratio can be reduced while observing the changes in the driving load conditions.

[0149] exist Fig.13 In the example shown, in detail, the assist torque is increased for the second time at a timing (time t4) after time T2 relative to the timing (time t2) at which the assist torque is about to increase. In addition, the speed ratio of the continuously variable transmission 61 is reduced for the second time at a timing (time t5) after time T1 relative to the timing (time t4) at which the assist torque is about to increase. The timing at which the assist torque is increased and the speed ratio of the continuously variable transmission 61 is reduced can be arbitrarily determined.

[0150] exist Fig.13 In the example shown, after the second reduction in the speed ratio of the continuously variable transmission 61 (specifically, at time t6), the speed difference between the target speed and the actual speed of the engine 3 is less than the predetermined speed difference (the second threshold value TH2 in this example). As a result, it is determined that the deviation between the target speed and the actual speed of the engine 3 accompanying the increase in the driving load has been eliminated, and the driving assistance is terminated in stages. By terminating the driving assistance, the consumption of the power of the battery 6 can be suppressed. In addition, by terminating the driving assistance, it is possible to suppress excessive application of torque to the driving transmission system.

[0151] In addition, the driving assistance can be suddenly set to a state where no driving assistance is performed (the assist torque is set to zero) at the time point when it is determined that the deviation between the target speed and the actual speed of the engine 3 has been eliminated. However, by terminating the driving assistance in stages as in the present embodiment, the possibility of the engine stalling due to a sudden decrease in the engine speed can be reduced.

[0152] exist Fig.13In the example shown, after the driving assistance is terminated (specifically, at time t7), the target speed of the engine 3 is restored to the original target speed. The original target speed refers to the target speed before the increase when the target speed is first increased (refer to time t2). The timing for restoring the target speed of the engine 3 to the original speed can be set to be the same as the timing for ending the driving assistance. However, as in the present embodiment, if it is configured to restore the target speed of the engine 3 to the original target speed after the driving assistance is terminated, the possibility of the engine 3 stalling due to a sharp decrease in the speed of the engine 3 can be reduced.

[0153] In addition, Fig.13 In the example shown, after the target speed of the engine 3 is restored to the original target speed (specifically, at time t8), the speed ratio of the continuously variable transmission 61 is restored to the original speed ratio. The original speed ratio refers to the speed ratio before the speed ratio is reduced when the speed ratio of the continuously variable transmission 61 is initially reduced (refer to time t3). The timing for restoring the speed ratio of the continuously variable transmission 61 to the original speed ratio can be set to be the same as the end timing of the driving assistance. However, as in the present embodiment, by setting the driving assistance to end and the target speed of the engine 3 to return to the original target speed, the speed ratio of the continuously variable transmission 61 can be increased on the basis of confirming that the speed of the engine 3 is stable at the target speed. In this way, it is possible to avoid the occurrence of a situation in which the load applied to the engine 3 is increased sharply at the time point when the speed of the engine 3 is not stable at the target speed, thereby causing the engine to stall.

[0154] exist Fig.14 In, also with Fig.13 Similarly, at the timing (time t2) when it is determined that the actual speed of the engine 3 deviates from the target speed, the driving assistance is started and the target speed of the engine 3 is increased. In addition, the speed ratio of the continuously variable transmission 61 is then reduced to increase the assist torque and reduce the speed ratio in stages. Fig.14 In the example shown, Fig.13 Unlike the example of , regardless of the above-mentioned measures, the state in which the deviation between the target rotation speed and the actual rotation speed of the engine 3 is not eliminated will continue.

[0155] exist Fig.14 In the example shown, when it is determined that the deviation between the target speed and the actual speed of the engine 3 has not been eliminated even after a predetermined time (time T3) has passed since the start of the driving assistance, the control device 41 stops the driving assistance and stops the driving based on the change of the speed ratio of the continuously variable transmission 61. By configuring in this way, it is possible to avoid the continuation of a state where the farm working machine 100 is subjected to a significant driving load. In addition, it is possible to suppress the excessive load on the motor generator 4. As a result, it is possible to avoid the occurrence of an undesirable situation such as damage to the farm working machine 100.

[0156] In addition, Fig.14 In the example shown, in addition to stopping the driving assist and stopping the driving, a process is also performed to restore the target speed of the engine 3 to the original target speed (see time t9). This can suppress useless fuel consumption, noise of the engine 3, etc. In addition, when the driving assist and the driving stop are performed, it is preferable to inform the operator of this situation. This can prevent the operator from misjudging the driving stop due to a malfunction of the farm working machine 100.

[0157] In addition, Fig.14 In the example shown, the following configuration is used: when the deviation between the target speed and the actual speed of the engine 3 is not eliminated even after the predetermined time has passed after the start of the assistance, the driving assistance is stopped, etc., but this is an example. Instead of the predetermined time, the field working machine 100 may travel a predetermined distance. In addition, as another embodiment, the following configuration may be used: when the speed difference between the target speed and the actual speed of the engine 3 reaches or exceeds the third threshold value TH3 that is greater than the first threshold value TH1, the driving assistance is stopped, etc.

[0158] Fig.15A and Fig. 15B 4 is a flowchart showing, by way of example, the flow of the rotation control of the engine 3 executed by the control device 41. Fig.15A and Fig. 15B It is just that due to the large number of steps that make up a series of processes, it was originally represented by one picture, so it was divided into two pictures for convenience. Fig.15A and Fig. 15B The illustrated flow starts when the farm working machine 100 starts traveling.

[0159] In step S21, the control device 41 (speed control unit 41c) determines the target speed of the engine 3 according to the operation amount of the speed change operation element. When the target speed of the engine 3 is determined, the process proceeds to the next step S22.

[0160] In step S22, the control device 41 (acceleration control unit 41b) determines the accelerator opening so as to achieve the determined target speed of the engine 3. Thus, the engine 3 starts driving at the target speed. When the accelerator opening is determined, the process proceeds to the next step S23.

[0161] In step S23, the control device 41 (acceleration control unit 41b) monitors whether the speed difference between the target speed and the actual speed of the engine 3 reaches a predetermined speed difference ( Fig.13 and Fig.14In the example shown, it is above the first threshold value TH1). When the speed difference between the target speed and the actual speed of the engine 3 reaches or exceeds the predetermined speed difference (Yes in step S23), the process proceeds to the next step S24. When the speed difference between the target speed and the actual speed of the engine 3 is less than the predetermined speed difference (No in step S23), the monitoring of step S23 is continued.

[0162] In step S24, the control device 41 (acceleration control unit 41b) determines to increase the target speed (original target speed) previously determined by the speed change control unit 41c, so as to control the engine 3 in such a manner that the engine 3 performs an operation at the increased target speed. The increased target speed is, for example, set to the maximum speed (maximum speed) that can be achieved in the engine 3. In addition, in the case where the target speed of the engine 3 has reached the maximum speed, the processing of step S24 can be skipped. If the target speed of the engine 3 increases, the processing proceeds to the next step S25.

[0163] In step S25, the control device 41 (assist control unit 41a) causes the motor generator 4 to start driving assistance to assist the output of the engine 3. Driving assistance is preferably started substantially simultaneously with the increase in the previous target speed of the engine 3. When driving assistance is started, the process proceeds to the next step S26.

[0164] In step S26, the control device 41 (speed change control unit 41c) performs a process (speed ratio change process) of changing the speed ratio of the continuously variable transmission 61 so as to reduce the travel speed of the farm working machine 100. As a result, the speed of the farm working machine 100 is reduced. Preferably, after a predetermined time ( Fig.13 and Fig.14 In the example shown, the speed ratio changing process is executed after time T1. If the speed ratio changing process is executed, the process proceeds to the next step S27.

[0165] In addition, in this example, the following structure is formed: the speed ratio change process is always performed after the driving assistance is started, but the speed ratio change process may not be performed when the deviation between the target speed and the actual speed of the engine 3 is immediately eliminated by starting the driving assistance. In this case, the driving assistance can be terminated at any timing to restore the target speed of the engine 3 to the original target speed.

[0166] In step S27, the control device 41 (assist control unit 41a) monitors whether a predetermined time ( Fig.13 and Fig.14In the example shown, it is time T2. If the predetermined time has passed (Yes in step S27), the process proceeds to the next step S28. If the predetermined time has not passed (No in step S27), the monitoring in step S27 is continued.

[0167] In addition, in this example, the following structure is formed: the auxiliary torque increase process and the speed ratio change process that are performed in stages must be performed a specified number of times. However, in the case where the deviation between the target speed and the actual speed of the engine 3 is eliminated by the previous process of step S26 (speed ratio change process), the process of step S27 may not be performed. In this case, the end of driving assistance, the process of restoring the target speed of the engine 3 to the original target speed, and the process of restoring the speed ratio of the continuously variable transmission 61 to the original speed ratio can be performed at any timing. The content described here is the same as the case where the auxiliary torque is increased by step S28 described below to eliminate the deviation between the target speed and the actual speed of the engine 3.

[0168] In step S28, the control device 41 (assist control unit 41a) issues a command to increase the assist torque to the motor generator 4. As a result, the motor generator 4 increases the assist torque. When the assist torque increase command is issued, the process proceeds to the next step S29.

[0169] In step S29, the control device 41 (speed control unit 41c) performs a process (speed ratio change process) to change the speed ratio of the continuously variable transmission 61 so as to further reduce the travel speed of the farm working machine 100. As a result, the speed of the farm working machine 100 is further reduced. Preferably, a predetermined time ( Fig.13 and Fig.14 In the example shown, the speed ratio changing process is executed after time T1. If the speed ratio changing process is executed, the process proceeds to the next step S30.

[0170] In addition, in this example, the assist and the change of the speed ratio that are executed in stages are divided into two stages, but may be divided into three or more stages.

[0171] In step S30, the control device 41 (assist control unit 41a) determines whether the deviation between the target speed and the actual speed of the engine 3 has been eliminated. Specifically, the control device 41 determines whether the speed difference between the target speed and the actual speed of the engine 3 has been eliminated. Fig.13In the example shown, the second threshold value TH2 is below the target speed of the engine 3 to determine whether the deviation between the target speed and the actual speed of the engine 3 has been eliminated. If the speed difference between the two is below the predetermined threshold, it is determined that the deviation between the two has been eliminated (Yes in step S30), and the processing proceeds to the next step S31. If the speed difference between the two is greater than the predetermined threshold, it is determined that the deviation between the two has not been eliminated (No in step S30), and the processing proceeds to step S35.

[0172] In step S31, the control device 41 (auxiliary control unit 41a) determines whether a predetermined time has passed after the deviation between the target speed and the actual speed of the engine 3 is eliminated. The predetermined time can be arbitrarily determined. If the predetermined time has passed (Yes in step S31), the process proceeds to the next step S32. If the predetermined time has not passed (No in step S31), the process returns to step S30.

[0173] In step S32, the control device 41 (assist control unit 41a) controls the motor generator 4 and terminates the driving assistance in stages. Fig.13 In the example shown, the following structure is formed: at the time point when the deviation between the target speed and the actual speed of the engine 3 is eliminated, the end processing of the driving assistance is immediately started. In contrast, in the case of a structure in which the driving assistance is ended after a short time after the deviation is eliminated as in this example, the driving assistance can be ended in a state where the speed of the engine 3 is stable at the target speed. Therefore, compared with the case where the end processing of the driving assistance is started at a time point when the speed of the engine 3 may be unstable, the probability of the engine stalling can be reduced. If the end processing of the driving assistance is performed, the processing enters the next step S33.

[0174] In step S33, the control device 41 (acceleration control unit 41b) returns the target speed of the engine 3 to the original target speed. When the process of returning to the original target speed is performed, the process proceeds to the next step S34.

[0175] In step S34, the control device 41 (speed control unit 41c) performs processing to restore the speed ratio of the continuously variable transmission 61 to the original speed ratio so that the travel speed of the farm working machine 100 is restored to the original travel speed. If the speed ratio of the continuously variable transmission 61 is restored to the original speed ratio, the operation is temporarily terminated. Fig.15A and Fig. 15B Then, repeat as needed. Fig.15A and Fig. 15B Processing shown.

[0176] In step S35, the control device 41 (auxiliary control unit 41a) determines whether the deviation state between the target speed and the actual speed of the engine 3 continues for a predetermined time. The predetermined time can be arbitrarily determined. In the case where the deviation state continues for a predetermined time (Yes in step S35), the process proceeds to the next step S36. In the case where the deviation state does not continue for a predetermined time (No in step S35), the process returns to step S30.

[0177] In step S36, the control device 41 (assist control unit 41a) ends the driving assistance by the electric generator 4. In addition, the control device 41 (speed control unit 41c) changes the speed ratio of the continuously variable transmission 61 so that the field working machine 100 stops running (the running speed becomes zero). In addition, at this time, it is preferred that the control device 41 (acceleration control unit 41b) performs a process to restore the target speed of the engine 3 to the original target speed. If the process of step S36 is completed, the process proceeds to the next step S37.

[0178] In step S37, the control device 41 performs processing for notifying the operator that the farm work machine 100 is intentionally stopped. According to the notification processing, notification is performed based on a notification unit provided in the farm work machine 100 or a portable operation terminal for operating the farm work machine 100. As a result, the operator can understand the reason for stopping the farm work machine 100. The notification unit is, for example, a display device, a voice output device, etc.

[0179] In addition, in this example, if it is detected that the deviation state between the target speed and the actual speed of the engine 3 continues for a predetermined time, the driving stop is immediately executed based on the detection result of this one time. However, this structure is only an example. It is also possible to form a structure that repeatedly performs the following actions: when the deviation state continues for a predetermined time, for example, the driving assistance is temporarily terminated, and then, after the driving assistance is restarted, it is determined again whether the deviation state continues for a predetermined time. Moreover, it is possible to form a structure that performs the driving stop at the time point when the number of repeated actions reaches the predetermined number of times.

[0180] Fig.16 1 is a block diagram showing a modified example of a system for controlling the rotation of the engine 3. The system of the modified example is different in that the control device 41 has a differential lock control unit 41d as its function. In addition, in this modified example, a differential lock unit 62a is provided in the transmission 62 to stop the differential drive of a differential mechanism (not shown) that can differentially drive the left and right wheels 12a and 12b included in the travel device 12. That is, the field working machine 100 is provided with the differential lock unit 62a.

[0181] The differential lock control unit 41d (control device 41) controls the differential lock unit 62a to stop the differential drive according to the speed difference between the target speed and the actual speed of the engine 3. If the running load increases, the speed difference between the target speed and the actual speed of the engine 3 increases. Therefore, according to the structure of this modified example, when the running load increases, the differential drive can be stopped.

[0182] Regarding the field working machine 100, if the travel load increases, the driving force may not be transmitted evenly to the left and right wheels at a certain timing due to the action of the differential mechanism. Therefore, by forming a structure in which the differential drive is stopped when the speed difference between the target speed and the actual speed of the engine 3 reaches a predetermined speed difference or more, it is possible to prevent the differential drive from being performed at an unexpected timing due to the increase in the travel load. That is, when the travel load increases, the differential drive can be stopped and the driving force can be evenly distributed to the left and right wheels.

[0183] In addition, the predetermined speed difference for determining whether to stop the differential drive may be different from the predetermined speed difference for determining whether to start the driving assist ( Fig.13 The first threshold TH1) in is the same as that in , but can also be different.

[0184] In addition, the timing of stopping the differential drive can be any timing relative to the timing of increasing the target speed of the engine 3, the timing of starting the driving assist, and the timing of changing the speed ratio of the continuously variable transmission 61. For example, the timing of stopping the differential drive can be the same as the timing of starting the driving assist, or during the increase timing of the assist torque that increases in stages. In addition, it is preferred that the timing of stopping the differential drive can be changed and can be formed into a structure that can be arbitrarily set by the operator.

[0185] In addition, it is preferred that the stop of the differential drive executed in response to the increase of the driving load is released as the driving load decreases. Specifically, it is preferred that the differential lock control unit 41d controls the differential lock unit 62a to release the stop of the differential drive when it is determined that the deviation between the target speed and the actual speed of the engine has been eliminated. Fig.13 By releasing the stop of the differential drive according to the reduction of the travel load, for example, it is possible to avoid the adverse situation that the turning radius of the field working machine 100 becomes too large.

[0186] <5. Power generation control>

[0187] Next, a detailed example of control of power generation using the electric generator 4 will be described. In the following description, the control device 41 provided in the field working machine 100 controls the electric generator 4. The electric generator (first rotating electrical machine) 4 supplies power to the battery 6 by generating power using the driving force of the engine (prime mover) 3. The above contents are understandable from the above description, so detailed description is omitted.

[0188] In the field working machine 100 of the present embodiment, in addition to the case where the electric generator 4 is used as a motor to assist the output of the engine 3, it can also be continuously used as a generator. However, in the process of traveling in the field, the power of the engine 3 is preferably used as much as possible to drive the travel device 12. This is because if the proportion of the power of the engine 3 used for the power generation by the electric generator 4 is excessively increased, the output of the engine 3 cannot be fully supplied as the power for traveling when the traveling load increases, and there is a possibility of causing the engine to stall.

[0189] On the other hand, if the electric generator 4 is not used for power generation, the remaining capacity of the battery 6 may be excessively reduced in the field. If the remaining capacity of the battery 6 is excessively reduced, the working device 2 may not be driven by the motor 5, or the assist of the engine 3 by the electric generator 4 may not be achieved. Therefore, it is desirable to use the electric generator 4 to generate power within a possible range even when traveling in the field.

[0190] The power generation control of the electric generator 4 of the present embodiment is carefully designed based on the above viewpoints. To explain the overview, the control device 41 changes the setting of the power generation amount of the electric generator 4 based on the driving state of the driving machine body 1 of the field working machine 100. According to this structure, the power generation amount of the electric generator 4 can be reduced when the power allocated for driving should be increased, and the power generation amount of the electric generator 4 can be increased when it is not in such a state. That is, when there is a possibility that the driving load will increase, the power generation amount of the electric generator 4 can be reduced. As a result, it is possible to avoid the occurrence of a situation such as the engine stalling due to the output of the engine 3 not being able to be fully supplied as the power for driving in order to generate electricity.

[0191] In a little more detail, when the driving load is not large, in principle, the motor generator 4 supplies power to the battery 6 by generating power using the driving force of the engine 3 during the driving and stopping of the traveling body 1. Therefore, even during the driving of the traveling body 1, the reduction in the charging capacity of the battery 6 can be suppressed as much as possible. However, compared with the stopping of the traveling body 1, the control device 41 sets the power generation amount of the motor generator 4 during the driving of the traveling body 1 to be smaller. As a result, only the minimum power generation can be performed during the driving, and the power generation amount can be increased and the charging amount of the battery 6 can be increased during the driving stop when there is no need to allocate the power of the engine 3 to the driving.

[0192] In addition, the stop of the traveling body 1 mentioned here does not mean a stop for a very short time, but a state of stopping within a certain degree of concentrated time. Specifically, the stop of the traveling body 1 is a stop for the purpose of replenishing materials. Materials include seedlings, fertilizers, medicines, fuels, etc. Whether it is a stop for replenishing materials can be determined, for example, using the driving speed and the state of the working device 2. For example, when the driving speed is zero and the non-use state of the working device 2 continues for a certain period of time, it can be determined that it is a stop for replenishing materials. In the case where the field working machine 100 is a rice transplanter, for example, when the driving speed is zero and the non-grounding state of the float continues for a certain period of time, it can be determined that it is a stop for replenishing materials. In addition, the information on the replenishment location is pre-stored in the storage device 42 (refer to Figure 6 ), whether the stop is for material replenishment can be determined based on the position information of the field working machine 100 in addition to the travel speed.

[0193] Hereinafter, the power generation control of the motor generator 4 will be described by giving a specific example. Fig.17 1 is a diagram showing an example of the operation of the farm working machine 100 in the field 70. Here, the farm working machine 100 is a rice transplanter. Fig.17 The operation of the farm working machine 100 shown may be an operation based on manual driving or an operation based on automatic driving.

[0194] like Fig.17As shown, the field 70 includes a work area 71 and a headland area 72. The work area 71 is an area located in the central part of the field 70 and is used for work (transplanting of seedlings). The headland area 72 is an area located outside the work area 71 and is used to properly perform work in the work area 71. For example, the headland area 72 is used as an area for moving the field work machine 100 entering the field 70 to the work start position of transplanting work, etc., an area for turning the field work machine 100, and an area for moving the field work machine 100 to the supply location of materials such as seedlings and fertilizers. In addition, the supply location is set in the field ridge 73 adjacent to the headland area 72.

[0195] exist Fig.17 In FIG. 1 , a dashed line indicates a path along which the farm working machine 100 travels. An arrow included in the dashed line indicates a travel direction of the farm working machine 100. Fig.17 In FIG. 1 , the farm working machine 100 indicated by a dotted line indicates the farm working machine that has stopped for replenishment.

[0196] like Fig.17 As shown, the traveling machine body 1 of the field working machine 100 working in the field performs working travel along the straight path 74 and non-working travel along the turning path 75 connecting the straight paths 74. When the working starts, the field working machine 100 repeatedly plants (transplants) the rice seedlings on the straight path 74 and turns to move to the next straight path 74. In addition, the field working machine 100 periodically stops for replenishing the rice seedlings.

[0197] The electric generator 4 generates electricity at maximum output during the stop for seedling replenishment. The main purpose is that during the stop process, even if the electric generator 4 generates electricity at maximum output, there will be no problem such as insufficient power for driving, so the power of the engine 3 is used to charge the battery 6 as much as possible. In addition, the electric generator 4 generates the minimum required power during driving related to the operation (transplanting and turning). In addition, the minimum required power generation changes according to the remaining capacity of the battery 6, the content of the operation or the driving environment. Therefore, in this example, the following structure is formed: the optimal power generation during driving (the minimum required power generation) is calculated using information related to the energy balance of the previous operation.

[0198] More specifically, the following structure is formed: the period from the start of the operation travel to the completion of the stop for material replenishment is set as one cycle, and each time one cycle is completed, the optimal power generation in the next cycle of travel is obtained by using the information related to the energy balance of the one cycle. In addition, in this example, the following structure is formed: when solving the optimal power generation in the next cycle of travel, only the information related to the energy balance of the previous adjacent cycle is used, but it can also be formed as a structure that uses the information related to the energy balance of multiple cycles performed previously.

[0199] An example of a method for finding the optimal power generation during driving in the next cycle based on information related to the energy balance of a previous adjacent cycle is described. In addition, in the first cycle, it is impossible to find the optimal power generation during driving based on the information of the previous cycle. Therefore, for the first cycle, a default value, a value corresponding to previous actual performance, etc. are used as the optimal power generation during driving. It is preferred to prepare a plurality of default values ​​in a manner that can be selected according to the current remaining capacity of the battery 6. In addition, it is preferred to determine a value corresponding to previous actual performance based on the current remaining capacity of the battery 6.

[0200] When calculating the optimum power generation amount during the next cycle of traveling, the charging power required during the next cycle of traveling is obtained by the following formula (3). The values ​​of the items in formula (3) are absolute values.

[0201] AA=(BB-CC)+DD-EE×FF··· (3)

[0202] AA: Charging power required for the next cycle of driving [kWh]

[0203] BB: Capacity to be ensured [kWh]

[0204] CC: Current remaining capacity of the battery 6 [kWh]

[0205] DD: Discharge power of the current cycle [kWh]

[0206] EE: Power generation during shutdown [kW]

[0207] FF: Stop time of current cycle [hr]

[0208] The capacity BB to be secured is arbitrarily determined to be a capacity to such an extent that even if a situation occurs in which driving assistance is performed by the motor generator 4 , electric power for the remaining work can be secured.

[0209] The discharge power DD in the current cycle is an actual performance value of the current cycle, and is the total value of the power discharged by the motor 5 for the transplanting operation on each straight path 74. For example, when one cycle is "transplanting" → "turning" → "transplanting" → "turning" → "transplanting" → "turning" → "transplanting" → "stopping", the discharge power DD is the total value of the discharge power of each of the four "transplanting".

[0210] The power generation amount EE during stop is the power generation amount when the motor generator 4 generates power at the maximum output. The stop time FF in the current cycle is the actual performance value of the time stopped for replenishing materials (seedlings) in the current cycle.

[0211] The optimum power generation amount α [kW] during the next cycle of traveling is obtained by the following equation (4) using the charging power AA required during the next cycle of traveling obtained by equation (3).

[0212] α = AA / GG ··· (4)

[0213] GG: Total time required for transplanting and turning in the current cycle [hr]

[0214] In addition, the total time GG required for transplanting and turning in the current cycle is the actual performance value. For example, in the case where one cycle is "transplanting" → "turning" → "transplanting" → "turning" → "transplanting" → "turning" → "transplanting" → "stopping", it is the total time of each transplanting time of 4 "transplanting" and each turning time of 4 "turning".

[0215] Fig.18 Graph showing the change over time of the remaining capacity of the storage battery 6 when the power generation control is performed in this embodiment. Fig.18 In FIG. 6 , the horizontal axis is time [s] and the vertical axis is the remaining capacity of the battery 6. Fig.18 In the first cycle C1, the default value is used for the optimal power generation during transplanting and turning (driving). In the second cycle C2, the optimal power generation during transplanting and turning (driving) is the optimal power generation α during driving obtained based on the actual performance of the first cycle C1. In addition, each cycle is composed of "transplanting" → "turning" → "transplanting" → "turning" → "transplanting" → "turning" → "transplanting" → "stopping". That is, in each cycle, the combination of "transplanting" and "turning" is repeatedly executed 3 times, and then "stopping" is executed for replenishment after "transplanting" is executed again.

[0216] In each cycle, although the electric generator 4 is used to generate electricity during transplanting, the discharge power of the operation using the motor 5 is large, so the remaining capacity of the battery 6 decreases. In addition, in each cycle, the electric generator 4 is used to generate electricity only during turning, so the remaining capacity of the battery 6 increases. However, the turning time is short and the power generation is at a minimum, so the increase in the remaining capacity of the battery 6 during turning is small. In addition, in each cycle, during the stop for replenishment, the electric generator 4 is used to generate electricity only, so the remaining capacity of the battery 6 increases. Moreover, during the stop process, the power generation of the electric generator 4 is at the maximum output, and a certain degree of concentrated time can be ensured for charging the battery 6, so the remaining capacity of the battery 6 can be greatly increased.

[0217] In the power generation control of this embodiment, the power generation amount of the traveling machine body 1 is changed according to the content of the work performed during the work travel along the straight path 74. Thus, the power generation amount during each cycle is determined based on the actual performance value of the energy balance of the previous adjacent cycle.

[0218] For example, regarding an operation in which a large number of seedling mats are used per unit area (referred to as the first operation) and an operation in which a small number of seedling mats are used per unit area (referred to as the second operation), the number of transplanting and turning that are repeatedly performed during the period from the start of the operation until the stop for seedling replenishment (one cycle) changes. Specifically, in the case of the second operation, the number of repetitions of transplanting and turning in one cycle increases compared to the case of the first operation. Therefore, in the case of the second operation, the discharge power of the battery 6 during the execution of one cycle increases compared to the case of the first operation. In this case, it is necessary to prepare a larger discharge power supply, and therefore, regarding the optimal power generation during the execution of one cycle, it is sometimes preferred that the second operation be larger than the case of the first operation.

[0219] In addition, the field working machine 100 performs power generation control as described above in principle, but performs driving assistance using the electric generator 4 (assistance of the output of the engine 3) when the driving load increases. Therefore, power generation is sometimes stopped during operation and the electric generator 4 consumes power. In this case, power generation during operation is not performed, so the expected power generation amount cannot be ensured. Even in this case, if the above-mentioned method for solving the optimal power generation amount during driving is used, power generation including the amount lost due to driving assistance is performed in the next cycle, and the lost power can be basically recovered.

[0220] However, in a field environment where driving assistance is frequently performed, it is sometimes impossible to fully ensure the remaining capacity of the battery 6. When it is determined that a sufficient remaining battery capacity cannot be ensured, the control device 41 preferably notifies the operator in a manner of waiting for the start of the transplanting operation while the field working machine 100 is stopped. The means of the notification may be, for example, a voice guidance or a screen display.

[0221] <6. Notes, etc.>

[0222] Various technical features disclosed in this specification can be modified in various ways without departing from the spirit of the technical creation. In addition, the multiple embodiments and modifications shown in this specification can be combined and implemented within the possible range.

[0223] <7. Additional Notes>

[0224] The field working machine of the present invention shown as an example can be of the following structure (first structure), comprising: a traveling body having a traveling device; a working device supported on the traveling body; a prime mover that supplies driving force to the traveling device; a first rotating motor that is connected to the output shaft of the prime mover in a manner capable of transmitting power; and a second rotating motor that supplies driving force to the working device.

[0225] In the farmland working machine of the first structure, a structure (second structure) may be adopted in which the first rotating electrical machine is a motor generator and the second rotating electrical machine is a motor.

[0226] The farmland working machine of the first or second structure may be configured as follows (third structure) further including a battery electrically connected to the first rotating electric machine and the second rotating electric machine.

[0227] In the farmland working machine having any one of the first to third structures, the first rotating electric machine and the second rotating electric machine may be configured to be switchable between an electrically connected state and an electrically disconnected state (a fourth configuration).

[0228] Based on the field working machine of any one of the first to fourth structures mentioned above, it can be formed into the following structure (fifth structure), which also has a switching mechanism for switching the power transmission state between the first rotating motor and the second rotating motor to any one of a connected state and a disconnected state.

[0229] The farm working machine of any one of the first to fifth structures may be configured as follows (sixth structure) to change the operating state of the first rotating electrical machine according to the load applied to the prime mover during travel, i.e., the travel load, or an index value of the travel load.

[0230] In the field working machine of the sixth configuration, a configuration (seventh configuration) may be adopted in which, when the travel load or the index value reaches or exceeds a first threshold value, the first rotating electrical machine stops generating power.

[0231] The farm working machine of the seventh configuration may be configured as follows (eighth configuration) when the travel load or the index value reaches or exceeds a second threshold value greater than the first threshold value, the first rotating electrical machine assists the output of the prime mover.

[0232] On the basis of the field working machine of the eighth structure mentioned above, the following structure (ninth structure) can be formed, which is equipped with a switching mechanism for switching the power transmission state between the first rotating motor and the second rotating motor to any one of a connected state and a disconnected state. When the driving load or the index value reaches a third threshold value greater than the second threshold value, the switching mechanism is formed into the connected state, and the second rotating motor does not supply driving force to the working device but assists the output of the first rotating motor.

[0233] Based on a field working machine of any one of the first to fifth structures mentioned above, the following structure (the tenth structure) can be formed, wherein the prime mover is an engine and is provided with: a continuously variable transmission device, which changes the speed of the power from the engine and outputs it to the travel device; and a control device, which controls the engine, the first rotating motor and the continuously variable transmission device, wherein the control device detects the speed difference between the target speed and the actual speed of the engine, and when the speed difference reaches or exceeds a specified speed difference, the control device assists the output of the engine by the first rotating motor and reduces the travel speed based on the change of the speed ratio of the continuously variable transmission device.

[0234] The farm working machine of the tenth configuration may be configured as follows (eleventh configuration) wherein, when the rotation speed difference reaches or exceeds a predetermined rotation speed difference, the control device increases a target rotation speed of the engine to perform the assist.

[0235] In the above-mentioned farmland working machine of the tenth or eleventh structure, it may be configured as follows (twelfth structure) that the control device executes the change of the speed ratio after the assist is started.

[0236] In the farmland working machine of any one of the tenth to twelfth structures, a structure (thirteenth structure) may be adopted in which the control device executes the assist and the change of the speed ratio in stages.

[0237] Based on the field working machine of any one of the above-mentioned tenth to thirteenth structures, the following structure (fourteenth structure) can be formed, in which the control device executes the stop of the assistance and the driving stop based on the change of the speed ratio when it is determined that the deviation between the target speed and the actual speed of the engine has not been eliminated even after a prescribed time has passed after the assistance is started.

[0238] Based on a field working machine of any one of the above-mentioned tenth to fourteenth structures, the following structure (fifteenth structure) can be formed, which is equipped with a differential locking unit that stops the differential drive of the differential mechanism, and the differential mechanism can differentially drive the left and right wheels included in the traveling device, and the control device controls the differential locking unit according to the speed difference to stop the differential drive.

[0239] Based on the field working machine of the third or fourth structure mentioned above, the following structure (sixteenth structure) can be formed, which is equipped with a control device for controlling the electric generator, and the control device changes the setting of the power generation of the first rotating motor that supplies electricity to the battery by utilizing the driving force of the prime mover based on the driving state of the traveling body.

[0240] Based on the above-mentioned sixteenth structure of the field working machine, the following structure (seventeenth structure) can be formed, wherein the first rotating motor supplies electric power to the battery by utilizing the driving force of the prime mover to generate electricity during the travel and stop of the travel body, and the control device sets the power generation amount when the travel body is stopped to be larger than that when the travel body is traveling.

[0241] Based on the above-mentioned sixteenth or seventeenth structure of the field working machine, the following structure (eighteenth structure) can be formed, wherein the traveling body performs working travel along a straight path and non-working travel along a turning path connecting the straight paths, and the power generation during the travel of the traveling body is changed according to the content of the work performed during the working travel.

[0242] In the field working machine of any one of the sixteenth to eighteenth structures, a structure (nineteenth structure) may be adopted in which the stopping of the traveling body is a stopping for replenishing materials.

Claims

1. A field working machine, wherein: The field working machine comprises: A traveling body having a traveling device; A working device supported on the traveling body; a prime mover that supplies driving force to the travel device; A first rotating electrical machine connected to an output shaft of the prime mover in a power-transmitting manner; as well as A second rotating electric machine supplies driving force to the working device.

2. The field working machine according to claim 1, wherein: The first rotating electrical machine is a motor generator, The second rotating electrical machine is a motor.

3. The field working machine according to claim 1 or 2, wherein: The farmland working machine further includes a battery electrically connected to the first rotating electric machine and the second rotating electric machine.

4. The field working machine according to claim 3, wherein: The first rotating electrical machine and the second rotating electrical machine are provided so as to be switchable between an electrically connected state and an electrically disconnected state.

5. The field working machine according to claim 1 or 2, wherein: The farm working machine further includes a switching mechanism that switches a power transmission state between the first rotating electric machine and the second rotating electric machine to either a connected state or a disconnected state.

6. The field working machine according to claim 1 or 2, wherein: The operating state of the first rotating electrical machine is changed according to a travel load which is a load applied to the prime mover during travel, or an index value of the travel load.

7. The field working machine according to claim 6, wherein: When the travel load or the index value reaches or exceeds a first threshold, the first rotating electrical machine stops generating power.

8. The field working machine according to claim 7, wherein: When the travel load or the index value reaches or exceeds a second threshold value that is larger than the first threshold value, the first rotating electrical machine assists the output of the prime mover.

9. The field working machine according to claim 8, wherein: The farm working machine includes a switching mechanism for switching a power transmission state between the first rotating electric machine and the second rotating electric machine to either a connected state or a disconnected state. When the travel load or the index value reaches or exceeds a third threshold value that is larger than the second threshold value, the switching mechanism is in the connected state, and the second rotating electric machine assists the output of the first rotating electric machine without supplying driving force to the working device.

10. The field working machine according to claim 1, wherein: The prime mover is an engine, The field working machine comprises: a continuously variable transmission device that changes the speed of the power from the engine and outputs the power to the travel device; and a control device for controlling the engine, the first rotating electrical machine, and the continuously variable transmission device, The control device detects the speed difference between the target speed and the actual speed of the engine, and when the speed difference reaches or exceeds a specified speed difference, performs output assistance of the engine by the first rotating motor and reduces the driving speed based on the change of the speed ratio of the continuously variable transmission.

11. The field working machine according to claim 10, wherein: The control device increases the target speed of the engine and executes the assist when the speed difference reaches or exceeds a predetermined speed difference.

12. The field working machine according to claim 10 or 11, wherein: The control device executes the change of the speed ratio after the assist is started.

13. The field working machine according to claim 10, wherein: The control device executes the assist and the change of the speed ratio in stages.

14. The field working machine according to claim 10, wherein: The control device stops the assist and stops the vehicle from traveling by changing the speed ratio when it is determined that the deviation between the target speed and the actual speed of the engine has not been eliminated even after a predetermined time has passed since the assist was started.

15. The field working machine according to claim 10, wherein: The farm working machine includes a differential lock unit for stopping differential drive of a differential mechanism capable of differentially driving left and right wheels included in the travel device. The control device controls the differential locking portion according to the rotation speed difference to stop the differential drive.

16. The field working machine according to claim 3, wherein: The farm working machine includes a control device for controlling the electric generator. The control device changes setting of an amount of power generated by the first rotating electrical machine that supplies electric power to the battery by generating electric power using a driving force of the prime mover, based on a traveling state of the traveling machine body.

17. The field working machine according to claim 16, wherein: The first rotating electrical machine supplies electric power to the battery by generating electric power using the driving force of the prime mover while the traveling machine body is traveling or stopped. The control device sets the power generation amount to be larger when the traveling machine body is stopped than when the traveling machine body is traveling.

18. The field working machine according to claim 17, wherein: The traveling machine body performs working traveling along a straight path and non-working traveling along a curved path connecting the straight paths. The amount of power generation during travel of the travel machine body is changed according to the content of work performed during the work travel.

19. The field working machine according to claim 17, wherein: The stopping of the traveling machine body is a stopping for replenishing materials.

Images