Paddy field farming machine

Abstract

To provide a rice field implement configured to reduce time and efforts for an operator to charge a battery for supplying electric power to an electric motor while suppressing fuel consumption and an amount of discharge of exhaust gas.SOLUTION: A rice field implement includes: an engine as a power source for a travelling device; a transmission mechanism for transmitting rotation power output from the engine to the travelling device; power distribution means for distributing part of the rotation power from the transmission mechanism; and an electric power generator for generating electric power by receiving the rotation power distributed by the power distribution means. The electric power generated by the electric power generator when the engine is actuated is configured to be stored in a battery. The travelling device is configured by including a pair of right and left wheels. The power distribution means distributes, to the electric power generator, part of the rotation power transmitted to the pair of right and left wheels from a pair of right and left wheel gear cases. The electric power generated by receiving the rotation power distributed by the power distribution means is configured to be stored in the battery.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to paddy field working machines such as rice transplanters, combine harvesters, and tractors that are capable of performing agricultural work in paddy fields. [Background technology]

[0002] BACKGROUND ART Paddy field working machines equipped with an engine as a power source for the machine body have been widely known.

[0003] For example, Patent Document 1 discloses a paddy field working machine (rice transplanter) in which the rotational power output from an engine is changed in speed by a transmission mechanism such as a hydrostatic continuously variable transmission (so-called HST), and then transmitted to a running device including front and rear wheels and a working machine consisting of a seedling planting section.

[0004] However, in the case of the paddy field working machine described in Patent Document 1, the engine is used as a power source to drive both the traveling device and the working machine, which poses the problem of increased engine fuel consumption and exhaust gas emissions.

[0005] To address this issue, Patent Document 2 describes a paddy field working machine configured as a combine harvester that is equipped with an electric motor as a power source for the traveling device and working machine, instead of or in addition to an engine. By using an electric motor as a power source, it is possible to eliminate or reduce engine fuel consumption and exhaust gas emissions. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-030945 [Patent Document 2] Japanese Patent Publication No. 2022-000724 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when an electric motor is used as a power source for a traveling device and / or a work machine, as in the invention described in Patent Document 2, the worker is required to charge the battery that supplies power to the electric motor each time, which increases the worker's workload.

[0008] Therefore, the present invention aims to provide a paddy field working machine that is configured to reduce fuel consumption and exhaust gas emissions while reducing the effort required by the operator to charge the battery that supplies power to the electric motor. [Means for solving the problem]

[0009] The object of the present invention is to A paddy field working machine having a traveling device and a working machine for performing agricultural work, an engine as a power source for the traveling device; a transmission mechanism that transmits rotational power output from the engine to the traveling device; a power distribution means for distributing a portion of the rotational power from the transmission mechanism; a generator that receives the rotational power distributed by the power distribution means and generates electricity, The electric power generated by the generator during operation of the engine is stored in a battery, The traveling device includes a pair of left and right wheels, The power distribution means left a part of the rotational power transmitted from the right pair of wheel gear cases to the pair of left and right wheels is distributed to the generator; This object is achieved by a paddy field working machine that is configured to receive the rotational power distributed by the power distribution means, generate electricity, and store the electricity in the battery.

[0010] According to the present invention, the agricultural work machine is configured to be driven by an electric work motor, so that the engine output can be reduced, thereby suppressing fuel consumption and exhaust gas emissions.

[0011] In addition, according to the present invention, a portion of the rotational power output from the engine is distributed by a power distribution means from the transmission mechanism that transmits the rotational power to the traveling device to a generator, and the electricity generated by this generator is stored in a battery that supplies the electricity, thereby reducing the effort required for the worker to charge the battery.

[0012] In a further preferred embodiment of the present invention, The generator is configured by a motor generator having a function as a generator and a function as an electric motor, and when power is supplied from the battery, the power distribution means, one The gear case is configured to transmit rotational power to a pair of the wheels through the pair of wheel gear cases.

[0013] According to this preferred embodiment of the present invention, when the generated electricity is supplied from a battery storing the electricity to a generator formed by a motor generator, rotational power is transmitted to a pair of wheels, thereby enabling EV driving.

[0014] In a further preferred embodiment of the present invention, The work machine is configured with a seedling planting unit that plants seedlings in a field, The seedling planting section includes a seedling tank on which a seedling mat is placed, a planting device that plants the seedlings located at the lower end of the seedling tank in a field, and a seedling feed belt that transports the seedling mat placed in the seedling tank to the lower end of the seedling tank. The seedling tank, the planting device, and the seedling feed belt are driven by the working electric motor. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a paddy field working machine that is configured to reduce fuel consumption and exhaust gas emissions while reducing the effort required by the operator to charge the battery that supplies power to the electric motor. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic left side view of a paddy field working machine according to a preferred embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view of the paddy field working machine shown in FIG. [Figure 3] FIG. 3 is a block diagram showing the flow of power in the paddy field working machine shown in FIG. [Figure 4] FIG. 4 is a schematic plan view of the vicinity of the engine shown in FIG. [Figure 5] FIG. 5 is a graph that schematically shows the relationship between the rotation speed and torque of the engine shown in FIG. [Figure 6] FIG. 6 is a schematic diagram showing the flow of current between the second motor generator and the second and third batteries shown in FIG. [Figure 7] FIG. 7 is a graph showing the relationship between the rotation speed and torque of the engine shown in FIG. [Figure 8] FIG. 8 is a schematic perspective view showing an engine of a paddy field working machine according to another preferred embodiment of the present invention. [Figure 9] FIG. 9 is a schematic perspective view showing an engine of a paddy field working machine according to still another preferred embodiment of the present invention. [Figure 10] FIG. 10 is a schematic front view of the engine shown in FIG. 9 with the various gears exposed. [Figure 11] FIG. 11 is a graph showing the relationship between the motor rotation speed and time when starting the engine shown in FIG. [Figure 12] FIG. 12 is a graph showing the relationship between the load on the engine and time of a paddy field working machine according to still another preferred embodiment configured as a tractor. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0018] FIG. 1 is a schematic left side view of a paddy field working machine 1 according to a preferred embodiment of the present invention, and FIG. 2 is a schematic plan view of the paddy field working machine 1 shown in FIG.

[0019] FIG. 3 is a block diagram showing the flow of power in the paddy field working machine 1 shown in FIG. 1, with the flow of power indicated by gray arrows.

[0020] In this specification, as shown by the arrows in Figures 1 and 2, the direction of travel of the paddy field working machine 1 is referred to as the "front" and the opposite side is referred to as the "rear", and the left side facing forward, which is the direction of travel of the paddy field working machine 1, is referred to as the "left" and the opposite side is referred to as the "right".

[0021] The paddy field working machine 1 includes a traveling body 2, a seedling planting unit 63 attached to the rear of the traveling body 2, a fertilizer applicator 26 that supplies fertilizer to the field, a power mechanism shown in Figure 3, and a control unit 87 that controls the entire machine. In this embodiment, the paddy field working machine 1 is configured as a rice transplanter.

[0022] The traveling body 2 comprises a main frame 3 located approximately in the center in the width direction of the body 2, a rear frame 6 attached to the rear end of the main frame 3 and extending in the width direction of the paddy field working machine 1, a link base frame 10 fixed to the rear frame 6, a floor step 60 located above the main frame 3, a driver's seat 48 provided above the floor step 60, a control section 49 for operating the machine, and a pair of left and right front wheels 8 and a pair of left and right rear wheels 9 that serve as traveling devices. Hereinafter, the pair of front wheels 8 and the pair of rear wheels 9 will also be referred to as "traveling wheels".

[0023] The control unit 49 includes a main speed change lever 35 for changing the forward / reverse movement and vehicle speed of the traveling body 2, a brake pedal 81 (see Figure 2) for stopping the traveling body 2, a steering mechanism 28 including a steering wheel 56 for steering the pair of left and right front wheels 8, an SS lever 79 connected to the brake pedal 81, and a green mode switch 23 (see Figure 2) which will be described in detail later.

[0024] In addition to the steering wheel 56, the steering mechanism 28 includes a steering shaft housed in a steering post 83, a pitman arm, and a tie rod (not shown).

[0025] The power mechanism includes an engine 7 located below the driver's seat 48, a transmission mechanism 15 that transmits the rotational power output from the engine 7 to a pair of left and right front wheels 8 and rear wheels 9, a pair of left and right first motor generators 33 that generate electricity using the power distributed from the transmission mechanism, an electric motor 18 that drives a seedling planting section 63, which is an example of a "work machine" of the present invention, and a first battery 17 that supplies power to the electric motor 18. The electric motor 18 corresponds to the "work electric motor" of the present invention.

[0026] 1, a hydrostatic continuously variable transmission (hereinafter referred to as "HST") 25 that changes the speed of the rotational power transmitted by the belt-type power transmission mechanism 4, a front gear case 30 that changes the speed of the power output from the HST 25 and then outputs it to the traveling wheels 8, 9, a pair of left and right front wheel final cases 13 arranged on the left and right of the front gear case 30, a pair of left and right rear wheel gear cases 51 arranged on the left rear and right rear of the front gear case 30, and a pair of left and right rear wheel transmission shafts 14 that transmit power from the front gear case 30 to the pair of rear wheel gear cases 51. The front gear case 30 corresponds to the "front gear case" of this invention.

[0027] The rotational power output from the engine 7 is transmitted to the HST 25 via the belt-type power transmission mechanism 4, and then the speed is changed within the HST 25 to a speed that corresponds to the operating position of the main shift lever 35, and then transmitted to the front gear case 30. The front gear case 30 is fixed to the front part of the main frame 3.

[0028] The rotational power transmitted to the front gear case 30 is changed in speed inside the front gear case 30 according to the operating position of the auxiliary speed change lever 36. After that, part of the rotational power is output to a pair of front wheel final cases 13, and is transmitted from the front wheel final cases 13 to a pair of front wheels 8 via a front wheel support section and a front wheel axle 31 whose steering direction can be changed, and also to a pair of rear wheels 9 via a pair of rear wheel transmission shafts 14 formed by a propeller shaft, a pair of rear wheel gear cases 51, and a rear wheel axle 82. As a result, the traveling vehicle body 2 moves forward or backward.

[0029] Here, a portion of the rotational power transmitted to the left and right rear wheel gear cases 51 through the left and right rear wheel transmission shafts 14 is distributed by a pair of left and right power distribution means 32 and transmitted to a pair of first motor generators 33 (see Figure 3).

[0030] As a result, power is generated by rotating the rotors of the pair of first motor generators 33. The pair of first motor generators 33 is an example of the "generator" of the present invention, but it is not necessarily required to use a motor generator as the generator.

[0031] The power distribution means 32 can be configured as follows, for example, as a belt-type power distribution mechanism. That is, first, a first pulley is attached to a downstream portion of each rear wheel transmission shaft 14 (a rear portion of each rear wheel transmission shaft 14 that is located inside the rear wheel gear case 51) so as to rotate integrally with the rear wheel transmission shaft 14. Also, a second pulley is attached to an input shaft to the first motor-generator 33 so as to rotate integrally with the input shaft. Then, by wrapping an endless belt around the first and second pulleys, when the engine 7 is operating, the first and second pulleys, the belt, and the input shaft to the first motor-generator 33 rotate as the rear wheel transmission shaft 14 rotates. Note that the power distribution means 32 may be configured with another distribution mechanism.

[0032] Meanwhile, the electric power generated by the left and right first motor generators 33 is stored in the first battery 17, which supplies power to the electric motor 18. In this way, the first battery 17 is automatically charged when the engine 7 is running, reducing the effort required for the worker to charge the first battery 17. The first battery 17 is housed in a single battery case (housing) 17a (see FIG. 3). The first battery 17 may have one or more battery cells and battery modules. Furthermore, in addition to charging using the first motor generators 33, the first battery 17 may also be configured to be charged using a home charger or the like. This prevents work from being interrupted in the unlikely event that the remaining battery power of the first battery 17 becomes low.

[0033] In this embodiment, a clutch for connecting and disconnecting power transmission is provided in the front gear case 30 and in each rear wheel gear case 51. When the clutch in the front gear case 30 is disconnected, rotation of the pair of rear wheel transmission shafts 14 stops, and power generation by the pair of first motor-generators 33 is stopped. In contrast, the clutch provided in the rear wheel gear case 51 is located downstream of the power distribution means 32 in the power transmission path to the rear wheels 9. Therefore, even when the clutch in the rear wheel gear case 51 is disconnected, power generation by the pair of first motor-generators 33 can continue. Note that the clutch in the rear wheel gear case 51 is disconnected in order to disconnect power transmission to the rear wheel 9 on the inside of the turn, for example, during turning. This allows the rice paddy work machine 1 to make smooth and tight turns.

[0034] The drive of the electric motor 18 is switched on and off by operating a planting on / off switch 19 (see Figure 1) provided on the main speed change lever 35. If the electric motor 18 is configured as a DC motor, for example, the control unit 87 can be configured to turn on and off the drive by connecting and disconnecting the power supply to the electric motor 18 via a driver circuit based on the operation signal of the planting on / off switch 19.

[0035] On the other hand, if the electric motor 18 is configured as an AC motor, for example, by interposing an inverter between the first battery 17 and the electric motor 18, when an operation signal of the planting on / off switch 19 is sent to the control unit 87, the inverter can connect and disconnect the power supply from the first battery 17 to the electric motor 18 based on a control signal output from the control unit 87, thereby switching the electric motor 18 on and off. In this case, the DC current supplied from the first battery 17 is converted to AC by the inverter, and the frequency of the power supplied to the electric motor 18 is adjusted by the inverter based on the control signal output from the control unit 87, thereby changing the motor rotation speed.

[0036] While the paddy field working machine 1 travels by the rotational drive of the traveling wheels 8, 9 and the electric motor 18 is driven, the first battery 17 is in a so-called pass-through state in which discharging and charging are carried out simultaneously.

[0037] When the electric motor 18 is driven by the power supplied from the first battery 17, the planting transmission shaft 59 shown in FIG. 1 is rotated, and the seedling planting unit 63 plants seedlings in the field as follows.

[0038] As shown in Figure 1, the seedling planting section 63 comprises a seedling tank 65 for placing mat-like seedlings with soil (hereinafter referred to as "seedling mats"), a plurality of planting devices 64 provided behind and below the seedling tank 65, and seedling feed belts 72 arranged on each row above the seedling tank 65. The plurality of planting devices 64 are arranged in a line in the width direction of the paddy field working machine 1, and each planting device 64 comprises two pairs of planting tools 69 arranged in the front-to-rear direction (see Figure 2).

[0039] When the planting transmission shaft 59 is rotated by the electric motor 18, power is transmitted to each planting device 64 and each seedling feed belt 72 via the planting transmission unit 71 shown in FIG. 2. As a result, in each planting device 64, the front planting tool 69 and the rear planting tool 69 rotate around the drive shaft 67 shown in FIG. 1, alternately removing seedlings from the seedling outlet 70 at the bottom of the seedling tank 65 and planting them in the field. At the same time, each seedling feed belt 72 is driven, transporting the seedling mat placed in the seedling tank 65 downward, i.e., to the bottom of the seedling tank 65. Furthermore, as the planting transmission shaft 59 rotates, the cross-feed mechanism causes the seedling tank 63 to reciprocate left and right in conjunction with the planting operation of the planting device 64. This allows the seedlings to be planted next by the planting tools 69 to be supplied to each seedling outlet 70. The configuration for laterally feeding the seedling tank 63 (moving it back and forth left and right) by rotating the planting transmission shaft 59 is described in detail in JP-A-2008-182926 and is a known technique.

[0040] In this embodiment, as shown in Figure 2, a total of four rows of planting tools 69 are arranged in the left-right direction, forming a four-row planting configuration.Therefore, when the paddy field work machine 1 travels straight while planting seedlings in the field, four rows of seedlings are formed in the field.

[0041] As described above, in this embodiment, the electric motor 18 is driven by power supplied from the first battery 17 to operate the seedling planting unit 63. Therefore, the output of the engine 7 can be reduced compared to when both the traveling device and the work implement are driven by the engine, and the fuel consumption of the engine 7 and the amount of exhaust gas emitted can be kept low.

[0042] Furthermore, the transmission mechanism 15 transmits the rotational power output from the engine 7 to the running wheels 8, 9, and distributes the power to the first motor generator 33 to generate electricity, which is then stored in the first battery 17, thereby reducing the effort required for the operator to charge the first battery 17.

[0043] On the other hand, in this embodiment, a power distribution means is extended from the planting transmission shaft 59 to the fertilizer application transmission mechanism 21 (see FIG. 1 ) so that power is transmitted to the fertilizer application device 26 while the electric motor 18 is being driven. When the planting on / off switch 19 is operated and the electric motor 18 is driven, rotational power is transmitted to the fertilizer application device 26 via this power distribution means and the fertilizer application transmission mechanism 21. As a result, fertilizer is supplied to the field from the fertilizer application hopper 26a of the fertilizer application device 26 through the fertilizer application hose 26b. This power distribution means can be configured, for example, as with the power distribution means 32, by a belt-type transmission mechanism.

[0044] As shown in Figure 1, the seedling planting unit 63 is attached to the rear of the traveling body 2 so as to be able to rotate up and down by a lifting link device 5. The lifting link device 5 has an upper link arm 85 and a pair of lower link arms 86 on the left and right.

[0045] The front ends of the upper link arm 85 and the lower link arm 86 are attached to the link base frame 10 of the vehicle body 2, and the other ends are attached to the upper and lower link arms 11 located below the seedling planting section 63.

[0046] When the electronic hydraulic valve is controlled by the control unit 87 and the lifting hydraulic cylinder 12 shown in Figure 1 is hydraulically contracted, the upper link arm 85 is rotated rearward and upward, and the seedling planting unit 63 is raised to the non-working position. When the seedling planting unit 63 is in the non-working position, its lower end is positioned at approximately the same height as the bottom of the main frame 3.

[0047] In response to this, when the control unit 87 controls the electronic hydraulic valve and the lifting hydraulic cylinder 12 is extended hydraulically, the upper link arm 85 is rotated backward and downward, and the seedling planting unit 63 is lowered to a working position (see Figure 1) where seedlings can be planted.

[0048] FIG. 4 is a schematic plan view of the vicinity of the engine 7 shown in FIG.

[0049] In this embodiment, a timing gear 7a in the engine 7 transmits the rotation of the crankshaft to the camshaft, and a first PTO gear 37 that rotates and drives a hydraulic pump 39 and a second PTO gear 38 that rotates and drives a second motor generator 34 (rotor) that assists the rotation of the engine 7 are connected to the timing gear 7a.

[0050] In this way, by attaching the second motor generator 34 to the second PTO gear 38, The second motor-generator 34 that assists the rotation of the engine 7 can be mounted on the machine body without making major changes to the configuration around the engine of an existing paddy field working machine. The first and second PTO gears 37, 38 are located on the left and right sides of the engine 7, and the hydraulic pump 39 and second motor-generator 34 can be attached to either the left or right side of the engine 7.

[0051] In FIG. 4, "7b" denotes the cylinder block of the engine 7, "7c" denotes each cylinder in the cylinder block 7c, and "7d" denotes the timing gear case.

[0052] The second motor generator 34 receives rotational power output from the engine 7 via the second PTO gear 38, generates electricity through regenerative driving, and charges batteries 42, 43 (see FIG. 6), which will be described in detail later. When the rotation speed of the engine 7 drops by a specified number or more despite the accelerator opening remaining constant, the second motor generator 34 is driven to temporarily assist the rotation of the engine 7 using the electric power stored in the batteries 42, 43 under the control of the control unit 87. However, it is not necessarily necessary for the second motor generator 34 to assist when the engine rotation speed drops.

[0053] FIG. 5 is a graph that schematically shows the relationship between the rotation speed and torque of the engine 7 shown in FIG.

[0054] Conventional paddy field working machines have a problem in that the rotation speed of the engine 7 drops significantly when making sharp turns (in other words, turning with a small radius). To solve this problem, it is possible to configure the machine to assist the rotation of the engine with a motor generator, but constantly providing a large assist to the rotation of the engine increases battery consumption.

[0055] In light of this situation, when the rotation speed of the engine 7 drops by a specified number or more, the control unit 87 controls the amount of assist by the second motor generator 34 to be greater as the steering angle of the steering wheel 56 increases, based on the detection signal of a steering sensor that detects the turning angle of the steering wheel 56. In other words, the control unit 87 controls the amount of assist by the second motor generator 34 to be smaller as the turning angle of the steering wheel 56 decreases.

[0056] This makes it possible to reduce battery consumption while assisting the rotation of the engine 7 with the second motor generator 34 when the paddy field working machine 1 makes a sharp turn. The paddy field working machine 1 according to this embodiment is equipped with second and third batteries 42, 43, which will be described below, as batteries that store the electric power generated by the second motor generator 34 and supply electric power to the second motor generator 34 when the second motor generator 34 is driven (during engine assist).

[0057] FIG. 6 is a schematic diagram showing the flow of current between the second motor generator 34 and the second and third batteries 42, 43 shown in FIG.

[0058] The engine 7 according to this embodiment is configured as a diesel engine, and is provided with a DPF (Diesel Particulate Filter) 40 that removes harmful substances from exhaust gas.

[0059] The control unit 87 is configured to switch the power source and power supply destination of the second motor generator 34 between the second battery 42 and the third battery 43 by sending a control signal to a battery management unit (not shown).

[0060] Specifically, when the remaining charge of one of the batteries falls below a reference value, the control unit 87 assists the engine 7 by using the other battery as a power source for the second motor generator 34 when the engine 7 rotation speed drops due to high load.

[0061] In addition, when the exhaust temperature is low due to a low load on the engine 7 and passive regeneration of the DPF 40 cannot be performed (for example, when the vehicle is stopped to replenish seedlings), the control unit 87 actively (selectively) charges the battery 42 or 43 on the side with the lowest remaining battery charge.

[0062] This increases the charging load and raises the temperature of the exhaust gas, enabling efficient regeneration (burning of soot) within the DPF 40. In addition, the load on the engine 7 is leveled, improving fuel efficiency.

[0063] However, if only one battery is charged by the motor generator that assists the engine, there is a problem that charging cannot be performed when the remaining battery charge is full. In contrast, in this embodiment, the second and third batteries 42, 43 are provided as destinations for the power supply from the motor generator, thereby preventing such a situation. The second battery 42 and the third battery 43 are housed in separate battery cases (housings). Note that instead of or in addition to charging the battery 42 or 43 with low remaining battery charge, it is also possible to configure the system so that the second motor generator 34 is driven to increase the load on the engine 7. This allows the regeneration of the DPF 40 to be completed in a short time.

[0064] Furthermore, the control unit 87 is configured to actively (in other words, selectively) charge the battery 42 or 43 on the side with low battery charge during DPF active regeneration operation, which is performed when soot accumulates in the DPF 40 at a level above a reference value.

[0065] This increases the charging load and raises the temperature of the exhaust gas, enabling efficient regeneration (burning of soot) within the DPF 40. In addition, the load on the engine 7 is leveled, improving fuel efficiency.

[0066] On the other hand, when the paddy field working machine is configured as a combine harvester, when the engine load is low, such as when unloading rice or when hand-threshing, the exhaust temperature is low and passive regeneration of the DPF 40 cannot be performed, so it is desirable to configure the control unit to select and charge the battery on the side with the lowest remaining battery charge.

[0067] FIG. 7 is a graph showing the relationship between the rotation speed and torque of the engine 7 shown in FIG.

[0068] The engine 7 according to this embodiment is configured to be switchable between a normal mode, which depicts a normal torque curve, and a green mode, which depicts a torque curve with a torque smaller than the normal torque curve, each time the green mode switch 23 shown in Fig. 2 is pressed. When the engine 7 is set to the green mode and the rotation speed of the engine 7 falls below a specified value, the control unit 87 drives the second motor generator 34 to assist the rotation of the engine 7.

[0069] Generally, in the green mode, which draws a torque curve with reduced torque, low fuel consumption can be achieved, but there is a problem that engine output is reduced. In contrast, in this embodiment, the torque of the engine 7 can be assisted by driving the second motor generator 34, so that powerful output can be achieved while low fuel consumption is achieved.

[0070] Furthermore, in this embodiment, if the remaining battery power measured from the output voltage of the second and third batteries 42, 43 falls below a first predetermined value while the green mode is selected, the device automatically switches from the green mode to the normal mode. Thereafter, when the remaining power of one of the second and third batteries 42, 43 reaches or exceeds a second predetermined value that is greater than the first predetermined value, the device automatically switches (returns) to the green mode. This allows the green mode to continue, and eliminates the need for the operator to switch the green mode switch 23 when the remaining battery power becomes low, providing greater convenience.

[0071] 4 to 7 can also be applied to a configuration in which the seedling planting unit is driven by power transmitted from the engine, rather than by the electric work motor 18. In addition, the green mode configuration in FIG. 7 can also be applied to a configuration in which only a second battery housed in a single battery case is provided as the power source (power source) for the second motor generator 34. In this case, it is preferable that the green mode be automatically switched to normal mode when the remaining charge of the second battery 42 falls below a first predetermined value, and then the green mode be automatically switched to (returned to) when the remaining battery charge reaches or exceeds a second predetermined value.

[0072] <Technical significance of this embodiment> According to this embodiment shown in Figures 1 to 7, the seedling planting section 63 that performs the seedling planting work is configured to be driven by an electric motor 18, so the output of the engine 7 can be reduced, thereby suppressing fuel consumption and exhaust gas emissions.

[0073] Furthermore, according to this embodiment, a portion of the power from a pair of rear wheel gear cases 51 of the transmission mechanism 15 that transmits the rotational power output from the engine 7 to the traveling wheels 8, 9 is distributed by the power distribution means 32 to a pair of first motor generators 33 (an example of a generator), and the electric power generated by these first motor generators 33 is stored in the first battery 17 that supplies power to the electric motor 18, thereby reducing the effort required of an operator to charge the first battery 17. The left first motor generator 33 is an example of a "left-side generator" in the present invention, and the right first motor generator 33 is an example of a "right-side generator" in the present invention.

[0074] In addition, according to this embodiment, the power shifted by the HST 25 and the front gear case 30 is transmitted to a pair of rear wheel gear cases 51 through a pair of rear wheel drive shafts 14 (left rear wheel drive shaft 14 and right rear wheel drive shaft 14), and then transmitted from the pair of rear wheel gear cases 51 to the left and right rear wheels 9, and is also distributed to a pair of first motor generators 33 by a power distribution means 32, so that electricity can be generated effectively by the pair of first motor generators 33, resulting in a large amount of power.

[0075] Furthermore, according to this embodiment, the electricity generated by the pair of first motor generators 33 is configured to be stored in the first battery 17 housed in a single battery case 17a, so the electricity generated by the pair of first motor generators 33 can be combined into one, eliminating the need for a mechanism and control to switch the power source of the electric motor 18 between multiple battery cases.

[0076] Meanwhile, Figure 8 is a schematic perspective view showing the engine 7 of a paddy field working machine 1 according to another preferred embodiment of the present invention. Except for the points described below, this embodiment is configured in the same way as the paddy field working machine 1 according to the embodiment shown in Figures 1 to 7, and therefore provides the same effects.

[0077] The second motor generator 34 for assisting the engine 7 according to this embodiment is mounted on the crank pulley 7e connected to the crankshaft of the engine 7. Therefore, the second motor generator 34 generates electricity by being regeneratively driven in conjunction with the rotation of the crank pulley 7e, and is driven based on a control signal from the control unit 87 to assist the rotation of the crank pulley 7e when the rotation speed of the engine 7 drops by a specified number or more even though the accelerator opening is constant.

[0078] In this way, by configuring the output to be extracted from the crank pulley 7e during regenerative driving, the arrangement of the second motor generator 34 becomes easy.

[0079] In addition, in conventional work machines, it is common to install a motor generator in the generator unit, drive the motor generator when the engine is assisted, and transmit the output of the motor generator to the engine's timing belt. However, in this case, power is transmitted to the belt, which results in low transmission efficiency and a high load on the timing belt, shortening the life of the timing belt.

[0080] In contrast, in this embodiment, the output of the assist second motor generator 34 is transmitted to the crank pulley 7e when the second motor generator 34 is driven. This allows the power of the second motor generator 34 to be transmitted efficiently to the engine 7, and also eliminates the load on the timing belt 7f, thereby extending its lifespan.

[0081] Furthermore, if an abnormally high load is applied from the crank pulley 7e to the second motor generator 34, the connection between the second motor generator 34 and the crank pulley 7e will break, thereby preventing damage to the second motor generator 34.

[0082] The configuration according to FIG. 8 can also be applied to a configuration in which the seedling planting section is driven by power transmitted from an engine, rather than by the electric motor 18 for work.

[0083] On the other hand, Figure 9 is a schematic oblique view showing the engine 7 of a paddy field working machine 1 according to yet another preferred embodiment of the present invention, where Figure 9(a) is a schematic oblique view showing the state in which a gear case 7g is attached to the engine 7, and Figure 9(b) is a schematic oblique view showing the state in which the gear case 7g is removed from the engine 7.

[0084] FIG. 10 is a schematic front view showing various gears of the engine 7 shown in FIG. 9 exposed.

[0085] This embodiment is configured in the same way as the paddy field working machine 1 according to the embodiment shown in Figures 1 to 7, except for the points described below, and therefore can achieve the same effects.

[0086] The second motor generator 34 for assisting the engine 7 according to this embodiment is located below the high-pressure pump 7h of the engine 7 and above the side tap 7i, and is fixed to the front plate 7j. In conventional paddy field working machines, this location corresponds to where a hydropump is installed and power is transmitted via gear drive. Furthermore, the second motor generator 34 can generate electricity, eliminating the need for a conventional generator without motor functionality. Therefore, a belt tensioner (tension pulley) 7s is installed in the engine 7 where a generator without motor functionality was installed in conventional paddy field working machines. This configuration allows for the same component configuration as in the past (in other words, parts can be shared).

[0087] When the engine 7 speed drops below a predetermined value despite a constant accelerator opening, the power output from the second motor generator 34 is transmitted to the engine 7 side by the gear train 7k that drives the valves. In other words, the gear train 7k is driven by the second motor generator 34.

[0088] In this way, by using gear drive to transmit power from the second motor generator 34, the power of the second motor generator 34 can be efficiently transmitted to the engine 7, and the life of the timing belt 7f can be extended, similar to the embodiment shown in Figure 8. In addition, it is now possible to install a motor generator to assist the engine in a conventional paddy field working machine without requiring major changes to its shape.

[0089] Furthermore, by sharing the gear train 7k to drive the balancer, the second motor generator 34 can be arranged compactly. Note that it is also possible to install a motor without a power generation function instead of the second motor generator 34. In this case, the engine output can also be assisted by the motor.

[0090] In this embodiment, when abnormal combustion (overrun) occurs in the engine 7, the torque of the second motor generator 34 is used to decelerate the engine.

[0091] As shown in Fig. 10, the gear diameter of the idle gear 7m is preferably three or more times larger than that of the crank gear 7n, the motor generator gear 7o is preferably disposed below the high-pressure pump gear 7q, the motor generator gear 7o is preferably disposed above the crank gear 7n, the motor generator gear 7o is preferably disposed outward in the width direction of the engine 7 than the high-pressure pump 7h, and the motor generator gear 7o is preferably disposed on the side opposite to the cam gear 7p. Note that "7r" shown in Fig. 10 is a symbol indicating an oil pump gear.

[0092] In this embodiment, the DPF 40 is disposed horizontally above the engine 7, and a breather assembly with a heat insulating material is disposed rearward of the rear end of the rear plate.

[0093] FIG. 11 is a graph showing the relationship between the motor rotation speed and time when starting the engine 7 shown in FIG. 9, and also shows a time chart of the on / off driving of the starter motor and the second motor generator 34 until the engine 7 is started.

[0094] The paddy field working machine 1 according to this embodiment is equipped with a starter motor that starts the engine 7, in addition to a second motor generator 34 that assists the engine 7. If the rotation speed of the engine 7 is below a predetermined value when the starter motor is driven and then stopped, and it is determined that the rotation speed has not risen sufficiently, the control unit 87 is configured to drive the second motor generator 34 until the rotation speed of the engine 7 reaches or exceeds the predetermined value and is determined to have risen sufficiently. This allows the second motor generator 34 to assist in starting the engine 7, which prevents engine stalling or sluggish starting after the starter motor is stopped, particularly at low temperatures, and allows the engine 7 to start smoothly.

[0095] The configurations according to Figs. 9 to 11 can also be applied to a configuration in which the seedling planting section is driven by power transmitted from an engine, rather than by the electric motor 18 for work.

[0096] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these modifications are also included within the scope of the present invention.

[0097] For example, in each of the embodiments shown in FIGS. 1 to 11 , the first motor-generator 33 is used only as a generator. However, the first motor-generator 33, which functions both as a generator and an electric motor, may be configured to drive a work implement, such as the seedling planting unit 63 or the fertilizer applicator 26, when the vehicle is not traveling. In this case, the motor-generator 33 serves as both a "generator" and an "electric work motor" according to the present invention. Furthermore, the first motor-generator 33 may be driven to transmit power (reversely) to the power distribution means 32, which may be configured as a belt-type power transmission mechanism or the like, to rotate and drive the traveling wheels 8, 9 via the rear wheel gear case 51 and the rear wheel axle 82. In this case, the paddy field working implement 1 can be driven in EV mode by the motor-generator 33, without operating the engine 7, using rear-wheel drive, thereby preventing exhaust gas emissions. Furthermore, the vehicle can continue traveling even if the engine 7 stops due to a lack of fuel. In this case, the power transmission between the front gear case 30 and the HST 25 may be interrupted by disengaging the clutch within the front gear case 30, and the power transmission to the pair of front wheels 8 may also be interrupted.

[0098] In addition, the paddy field working machine 1 according to each embodiment shown in Figures 1 to 11 uses the first motor generator 33 as a "generator" that receives the rotational power distributed by the power distribution means and generates electricity, but it may also be configured to generate electricity using a generator that does not function as an electric motor.

[0099] Furthermore, the traveling device of the paddy field working machine 1 according to each embodiment shown in Figs. 1 to 11 includes the front wheels 8 and rear wheels 9, but may also include crawlers or the like.

[0100] In addition, in each of the embodiments shown in Figures 1 to 11, the rotational power changed in speed by the HST 25 is further changed in the front gear case 30 to a speed corresponding to the operating position of the sub-transmission lever 36, and then transmitted to the left and right rear wheels 9 through a pair of rear wheel transmission shafts and a pair of rear wheel gear cases 51. However, for example, the power may be electrically driven from the front gear case (which is further internally changed) that receives the changed power from the HST to a position near the left and right rear wheels by a single propeller shaft, and then transmitted to the left and right rear wheels via a differential mechanism arranged between the left and right rear wheels.

[0101] In this case, a power distribution means such as a belt is arranged on a single propeller shaft or on the rear wheel axles extending to the left and right from the differential mechanism, and power is distributed to a generator or motor generator, so that electricity can be generated using the power transmitted from the engine and used to drive an electric motor for work, allowing agricultural work to be carried out.

[0102] Furthermore, in each of the embodiments shown in Figures 1 to 11, power is distributed from the left and right rear wheel gear cases 51 to the first motor generator 33, but power distribution means to a generator that does not function as a motor generator or electric motor may be arranged, for example, in the power transmission path from the front gear case 30 to the front wheels 8, or in the power transmission path from the HST 25 to the front gear case 30, etc.

[0103] Furthermore, in each of the embodiments shown in Figures 1 to 11, the paddy field working machine 1 is configured as a rice transplanter, but the paddy field working machine according to the present invention may also be configured as a combine harvester, a tractor, etc.

[0104] For example, if the paddy field working machine is a combine harvester, it is preferable to assist the engine with the second motor generator when the engine speed drops by more than a specified number, but it is more preferable to increase the amount of power assist from the second motor generator on the condition that the engine speed drops by more than a specified number and the cutting unit is in operation. This reduces the drop in rotation during cutting work, improving workability, and by limiting the increase in the amount of assistance to the time of cutting work, it is possible to reduce battery consumption.

[0105] Furthermore, when the engine speed drops below a predetermined level and the second motor-generator assists the engine, it is preferable to increase the amount of assistance provided by the second motor-generator the more fuel is stored in the fuel tank. Generally, when making sharp turns, especially when the amount of fuel is large, the engine speed can drop significantly. However, by configuring in this way, it is possible to reduce the drop in engine speed and also reduce battery consumption when the amount of fuel stored is small.

[0106] Furthermore, when the paddy field working machine is configured as a tractor, it is preferable to assist the engine with the second motor generator when the engine speed drops by more than a specified number, but it is more preferable to increase the amount of power assist by the second motor generator when the engine speed drops by more than a specified number and towing mode is selected. During towing work, a large load is placed on the tractor, which tends to cause the engine speed to drop, but by providing assistance with the second motor generator, workability can be improved. In addition, by limiting the increase in the amount of assistance by the second motor generator to towing work, battery consumption can be reduced.

[0107] Additionally, when the paddy field working machine is a tractor, it is preferable to use the second motor generator to assist engine rotation when the engine speed drops by more than a specified number even when the engine accelerator pedal position is constant. In this way, by providing motor assistance only when the engine speed drops, it is possible to prevent the battery from running out of power early.

[0108] Furthermore, when the paddy field working machine is configured as a tractor, it is preferable to increase the amount of power assist by the second motor generator on the condition that the engine speed drops by a specified number or more within a predetermined time after the working machine lifting lever is moved to the down position. This reduces the drop in engine speed when the working machine touches the ground, improving workability, and by limiting the increase in the amount of assist to when the machine touches the ground, battery consumption can be reduced.

[0109] Furthermore, when the paddy field working machine is configured as a tractor, it is preferable to have the second motor generator assist engine rotation for several seconds from the time the rotary touches the ground (start of tilling) in conjunction with the "down" operation of the rotary lift switch, which raises and lowers the rotary as the working machine, as shown in Figure 12. Since the load on the engine is large when tilling begins immediately after the PTO is lowered and the rotary touches the ground, configuring it in this way can prevent deterioration of tilling characteristics and engine stalling.

[0110] Here, it is more preferable to configure the second motor generator to assist the engine rotation for a longer period of time as the remaining battery charge that supplies power to the second motor generator increases, and to configure the second motor generator to assist the engine rotation for a shorter period of time as the remaining battery charge decreases, thereby effectively preventing the battery from running out of power early.

[0111] The power assist for the combine harvester and the tractor may be configured to be performed by a motor without a power generating function, instead of the second motor generator. [Explanation of symbols]

[0112] 1 Paddy field farming equipment 2 Running vehicle 3. Mainframe 4 Belt-type power transmission mechanism 5 Lifting link device 6 Rear frame 7 Engine 8 front wheels 9 rear wheels 10 Link base frame 11 Upper and lower link arms 12 Lifting hydraulic cylinder 13 Front wheel final case 14 Rear wheel drive shaft 15 Power transmission mechanism 17 Battery 18 Electric motor 19 Planting on / off switch 21 Fertilizer transmission mechanism 23 Green mode switch 24 Sub-gear lever 25 HST 26 Fertilizer application equipment 27 Planting clutch motor 28 Steering mechanism 30 Mission Case 31 Front axle 32 Power distribution means 33 First motor generator 34 Second motor generator 35 Main gear shift lever 36 Sub-gear lever 37 1st PTO gear 38 Second PTO gear 39 Hydraulic Pump 40 DPF 42 Second Battery 43 Third Battery 45 Switching arm rotation shaft 47 Front cover 48 cockpit 49 Control Unit 51 Rear wheel gear case 56 Steering wheel 59 Planting transmission shaft 60 Floor Steps 63 Seedling planting department 64 Planting equipment 65 Seedling Tank 67 Drive shaft 69 Planting tools 70 Seedling outlet 71 Planting transmission unit 72 Seedling feeding belt 79 SS lever 81 Brake pedal 82 rear wheel axle 83 Steering post 85 upper link arm 86 Lower link arm 87 Control Unit

Claims

1. A paddy field working machine having a traveling device and a working machine for performing agricultural work, an engine as a power source for the traveling device; a transmission mechanism that transmits rotational power output from the engine to the traveling device; a power distribution means for distributing a portion of the rotational power from the transmission mechanism; a generator that receives the rotational power distributed by the power distribution means and generates electricity, The electric power generated by the generator during operation of the engine is stored in a battery, The traveling device includes a pair of left and right wheels, the power distribution means distributes a portion of the rotational power transmitted from the pair of left and right wheel gear cases to the pair of left and right wheels to the generator; a paddy field working machine configured to receive the rotational power distributed by the power distribution means, generate electricity, and store the electricity in the battery;

2. The paddy field working machine described in claim 1, characterized in that the generator is composed of a motor generator that has the function of both a generator and an electric motor, and is configured to transmit rotational power to the pair of wheels through the power distribution means and the pair of wheel gear cases when power is supplied from the battery.

3. an electric motor for driving the work machine; The work machine is configured with a seedling planting unit that plants seedlings in a field, The seedling planting section includes a seedling tank on which a seedling mat is placed, a planting device that plants the seedlings located at the lower end of the seedling tank in a field, and a seedling feed belt that transports the seedling mat placed in the seedling tank to the lower end of the seedling tank.

3. The paddy field working machine according to claim 1, wherein the seedling tank, the planting device, and the seedling feed belt are driven by the electric working motor.

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