Rice field implement

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, tractors, etc. capable of performing agricultural work in paddy fields. [Background technology]

[0002] 2. Description of the Related Art Paddy field working machines equipped with an engine as a power source for the machine body are 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 gear including front and rear wheels, and a working machine composed 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 the power source to drive both the traveling device and the working machine, which results in high engine fuel consumption and exhaust gas emissions.

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

[0006] [Patent Document 1] Patent Publication No. 2022-030945 [Patent Document 2] JP 2022-000724 A 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 battery that supplies power to the electric motor must be charged by the worker each time, which increases the worker's workload.

[0008] Therefore, an object of the present invention is 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 part 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; 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, since the working machine for performing agricultural work is configured to be driven by an electric working motor, the engine output can be reduced, and fuel consumption and exhaust gas emissions can be suppressed.

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

[0012] In a further preferred embodiment of the present invention, 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 a pair of wheels through the power distribution means and the pair of wheel gear cases when power is supplied from the battery.

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

[0014] In a further preferred embodiment of the present invention, The working 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 transport 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 configured to be driven by the working electric motor. Effect 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 description 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. [Diagram 2] FIG. 2 is a schematic plan view of the paddy field working machine shown in FIG. [Diagram 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. [Diagram 5] FIG. 5 is a graph that illustrates the relationship between the rotation speed and the torque of the engine shown in FIG. [Figure 6] FIG. 6 is a schematic diagram showing a current flow 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 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 constituted by a tractor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 grey 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 Fig. 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 arranged 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 arranged above the main frame 3, a driver's seat 48 provided above the floor step 60, a control section 49 for controlling the machine, and a pair of left and right front wheels 8 and a pair of left and right rear wheels 9 as traveling devices. Hereinafter, the pair of front wheels 8 and the pair of rear wheels 9 are also referred to as "traveling wheels".

[0023] The steering section 49 includes a main shift 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 provided 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 outputs the power output from the HST 25 to the traveling wheels 8, 9 after changing the speed, 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 the present 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 a 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 shift lever 36. After that, a part of the rotational power is output to a pair of front wheel final cases 13, and transmitted from the front wheel final cases 13 to a pair of front wheels 8 through 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 through a pair of rear wheel transmission shafts 14 constituted 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 FIG. 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 a "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, 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 winding an endless belt around the first pulley and the second pulley, the first and second pulleys, the belt, and the input shaft to the first motor generator 33 rotate in conjunction with the rotation of the rear wheel transmission shaft 14 when the engine 7 is operating. Note that the power distribution means 32 may be configured by 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 that supplies electric power to the electric motor 18. In this way, the first battery 17 is automatically charged when the engine 7 is operating, reducing the effort required of 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. In addition to charging using the first motor generators 33, the first battery 17 may be configured to be charged using a home charger or the like. This makes it possible to prevent work from being delayed 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 the 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, the rotation of the pair of rear wheel transmission shafts 14 is stopped, and the 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 disposed downstream of the power distribution means 32 in the power transmission path to the rear wheels 9. Therefore, even if the clutch in the rear wheel gear case 51 is disconnected, the power generation by the pair of first motor generators 33 can be continued. Note that the clutch in the rear wheel gear case 51 is disconnected for the purpose of disconnecting the power transmission to the rear wheels 9 on the inside of the turn, for example, during turning. This allows the paddy field working machine 1 to turn smoothly and with small turning radius.

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

[0035] On the other hand, when 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 power supply from the first battery 17 to the electric motor 18 can be connected and disconnected by the inverter to switch the electric motor 18 on and off based on a control signal output from the control unit 87. 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 seedlings are planted in the field by the seedling planting unit 63 as follows.

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

[0039] When the planting transmission shaft 59 is rotated by the drive of the electric motor 18, the rotation is transmitted to each planting device 64 and each seedling feed belt 72 through the planting transmission part 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 taking out seedlings from the seedling outlet 70 provided at the lower end of the seedling tank 65 and planting them in the field. At the same time, each seedling feed belt 72 is driven, and the seedling mat placed on the seedling tank 65 is transported downward, that is, to the lower end of the seedling tank 65. In addition, as the planting transmission shaft 59 rotates, the seedling tank 63 is configured to reciprocate left and right in conjunction with the planting operation of the planting device 64 by the lateral feed mechanism. As a result, the seedlings to be planted by the planting tool 69 next are supplied to each seedling outlet 70. The configuration for laterally feeding (reciprocating left and right) the seedling tank 63 by rotating the planting transmission shaft 59 is described in detail in JP 2008-182926 A and is a publicly 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 in a four-row planting configuration, so that when the paddy field working machine 1 travels straight ahead 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, compared to when both the traveling device and the working machine are driven by the engine, the output of the engine 7 can be reduced, 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] Meanwhile, in this embodiment, a power distribution means is extended from the planting transmission shaft 59 to the fertilization transmission mechanism 21 so that power is transmitted to the fertilization transmission mechanism 21 (see FIG. 1) which transmits power 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, the rotational power is transmitted to the fertilizer application device 26 through this power distribution means and the fertilization transmission mechanism 21. As a result, fertilizer is supplied to the field from the fertilization hopper 26a of the fertilizer application device 26 through the fertilization hose 26b. This power distribution means can be configured, for example, by a belt-type transmission mechanism, similar to the power distribution means 32.

[0044] 1, the seedling planting unit 63 is attached to the rear of the traveling body 2 so as to be vertically rotatable by a lifting link device 5. The lifting link device 5 includes 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 at the bottom of 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 Fig. 1 is hydraulically contracted, the upper link arm 85 is rotated upward and rearward, 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 hydraulically extended, 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 that transmits the rotation of the crankshaft to the camshaft in the engine 7 is connected to 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 (its rotor) that assists the rotation of the engine 7.

[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 body of the machine 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 disposed on the left and right sides of the engine 7, and the hydraulic pump 39 and the second motor generator 34 can be attached to either the left or right side of the engine 7.

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

[0052] The second motor generator 34 receives the 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 even though the accelerator opening is 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 to use the second motor generator 34 to assist when the engine rotation speed drops.

[0053] FIG. 5 is a graph that illustrates the relationship between the rotation speed and the 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 a sharp turn (in other words, a tight turn). To solve this problem, it is possible to configure the motor generator to assist the rotation of the engine, but constantly providing a large assist to the rotation of the engine will consume a lot of battery power.

[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 turning angle of the steering wheel 56 increases, based on a detection signal from 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] As a result, when the paddy field working machine 1 makes a sharp turn, battery consumption can be reduced while the second motor generator 34 assists the rotation of the engine 7. The paddy field working machine 1 according to this embodiment includes second and third batteries 42, 43 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 the 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 into a low remaining state 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 speed drops due to high load.

[0061] In addition, when the load on the engine 7 is low, causing the exhaust temperature to be low 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 with the lowest remaining battery charge.

[0062] This makes it possible to increase the charging load and raise the temperature of the exhaust gas, thereby enabling efficient regeneration (combustion of soot) within the DPF 40. In addition, the load on the engine 7 is also leveled, improving fuel efficiency.

[0063] Here, when only one battery is charged from the motor generator assisting the engine, there is a problem that charging cannot be performed when the battery level 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, so that such a situation can be prevented. The second battery 42 and the third battery 43 are housed in separate battery cases (housings). Instead of or in addition to charging the battery 42 or 43 on the side with the low battery level, it is also possible to configure 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 with the low battery charge during DPF active regeneration operation, which is performed when soot accumulates in the DPF 40 at or above a reference value.

[0065] This makes it possible to increase the charging load and raise the temperature of the exhaust gas, thereby enabling efficient regeneration (combustion of soot) within the DPF 40. In addition, the load on the engine 7 is also leveled, improving fuel efficiency.

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

[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 that of the normal torque curve, each time the green mode switch 23 shown in Fig. 2 is pressed. When the engine 7 is in 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 a reduced torque, low fuel consumption can be realized, but there is a problem that the 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 obtained while low fuel consumption is realized.

[0070] Furthermore, in this embodiment, when the remaining battery power measured from the output voltage of the second and third batteries 42, 43 falls below a first predetermined value while in the green mode, the mode is automatically switched 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 larger than the first predetermined value, the mode is automatically switched (returned) to the green mode. This allows the green mode to be continued, and eliminates the need for the operator to switch the green mode switch 23 when the remaining battery power is low, which is highly convenient.

[0071] 4 to 7 can also be applied to a configuration in which the seedling planting section is driven by power transmitted from an engine, not by the electric motor 18 for work. In addition, the green mode configuration in FIG. 7 can also be applied to a configuration in which only the 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 to configure the green mode to automatically switch to the normal mode when the remaining charge of the second battery 42 falls below a first predetermined value, and then to automatically switch (return) to the green mode when the remaining charge of the battery becomes equal to or greater than 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 that 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 is distributed by the power distribution means 32 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 to a pair of first motor generators 33 (an example of a generator), and the electricity 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 generator" in the present invention, and the right first motor generator 33 is an example of a "right generator" in the present invention.

[0074] In addition, according to this embodiment, the power changed in speed 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 side rear wheel drive shaft 14 and right side 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. Therefore, 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, Fig. 8 is a schematic perspective view showing the engine 7 of the paddy field working machine 1 according to another preferred embodiment of the present invention. This embodiment is configured similarly to the paddy field working machine 1 according to the embodiment shown in Figs. 1 to 7, except for the points described below, and therefore provides similar effects.

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

[0078] In this way, by configuring the output to be taken from the crank pulley 7e during regenerative driving, the second motor generator 34 can be easily disposed.

[0079] In addition, in conventional work machines, it is common to install a motor generator in the generator section, drive the motor generator when the engine is assisted, and transmit the output of the motor generator to the timing belt of the engine. However, in this case, since the power is transmitted to the belt, there are problems in that the transmission efficiency is low and the load on the timing belt is high, shortening the life of the timing belt.

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

[0081] Furthermore, when 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 breaks, 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 relating to yet another preferred embodiment of the present invention, 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 provide the same effects.

[0086] The second motor generator 34 for assisting the engine 7 according to this embodiment is disposed below the high pressure pump 7h of the engine 7 and above the side tap 7i, and is fixed to the front plate 7j. This position corresponds to the portion where a hydropump is attached and power is transmitted by gear drive in a conventional paddy field working machine. In addition, the second motor generator 34 can generate power, eliminating the need for a conventional generator without a motor function. For this reason, a belt tensioner (tension pulley) 7s is attached to the portion of the engine 7 where a generator without a motor function was attached in the conventional paddy field working machine. This configuration makes it possible to use the same parts configuration as in the past (in other words, parts can be shared).

[0087] When the rotation speed of the engine 7 drops by a specified number or more even though the accelerator opening is constant, 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 Fig. 8. In addition, it becomes possible to install a motor generator for the purpose of assisting the engine in a conventional paddy field working machine without making any major changes to its shape.

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

[0090] In this embodiment, when abnormal combustion (overrun) occurs in the engine 7, deceleration is performed by the torque of the second motor generator .

[0091] As shown in Fig. 10, the gear diameter of the idle gear 7m is preferably three times or more 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 outboard of the high-pressure pump 7h in the width direction of the engine 7, 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 portion of the rear plate.

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

[0094] The paddy field working machine 1 according to this embodiment includes a starter motor that starts the engine 7, in addition to the second motor generator 34 that assists the engine 7. When the starter motor is driven and stopped, if the rotation speed of the engine 7 is below a predetermined value and it is determined that the rotation speed has not increased 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 increased sufficiently. This allows the second motor generator 34 to assist the start of the engine 7, so that engine stall and sluggish start can be prevented, particularly at low temperatures, after the starter motor is stopped, and the engine 7 can be started smoothly.

[0095] The configuration 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 embodiment shown in FIG. 1 to FIG. 11, the first motor generator 33 is used only as a generator, but the first motor generator 33 having both a function as a generator and a function as an electric motor may be used to drive a work machine such as the seedling planting unit 63 or the fertilizer applicator 26, for example, when the machine is not traveling. In this case, the motor generator 33 serves as both the "generator" and the "work electric motor" of the present invention. Furthermore, the first motor generator 33 may be driven to transmit power (inversely) to the power distribution means 32 constituted by a belt-type power transmission mechanism or the like, and the traveling wheels 8, 9 may be rotated and driven via the rear wheel gear case 51 and the rear wheel axle 82. In this case, the paddy field working machine 1 can be driven in EV mode by the rear wheel drive by driving the motor generator 33 without operating the engine 7, and exhaust gas can be prevented from being discharged. In addition, even if the engine 7 stops due to lack of remaining fuel, the machine can continue traveling. 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 be interrupted.

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

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

[0100] In addition, in each embodiment 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-shift 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 changed inwardly) that receives the changed speed power from the HST to a position close to 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 type 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 an electric motor can be driven to perform agricultural work.

[0102] Furthermore, in each embodiment 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 a 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.

[0103] Further, 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, or the like.

[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 by 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] In addition, when the engine speed drops below a specified level and the second motor generator assists the engine, it is preferable to increase the amount of assistance by the second motor generator as the amount of fuel in the grain tank increases. Generally, when making a sharp turn, especially when the amount of fuel is large, the engine speed may drop significantly, but by configuring in this way, the drop in the engine speed can be reduced and battery consumption can be suppressed when the amount of fuel 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 to a specified number or more, but it is more preferable to increase the amount of power assist by the second motor generator on the condition that the engine speed drops to a specified number or more and the towing mode is selected. During towing work, a large load is applied to the tractor, so the engine speed is likely to drop, but by providing assistance from 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 when towing work is performed, battery consumption can be reduced.

[0107] In addition, when the paddy field working machine is a tractor, it is preferable to assist engine rotation with the second motor generator when the engine speed drops by a specified number or more even though the engine accelerator opening is constant. In this way, by performing motor assistance only when the engine speed drops, it is possible to prevent the battery from running out of power early.

[0108] In addition, when the paddy field working machine is 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 during a specified time after the working machine lift lever is moved to the lowered position. This reduces the drop in engine speed when the working machine touches the ground, improving workability and reducing the amount of assist by the second motor generator. By limiting the increase in strike amount to when the vehicle is on 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 rotary touching the ground (start of plowing) in conjunction with the "down" operation of the rotary lift switch that raises and lowers the rotary as the working machine, as shown in Figure 12. Since the load on the engine is large at the start of plowing immediately after the PTO is lowered and the rotary touches the ground, by configuring in this way, it is possible to prevent deterioration of plowing characteristics and engine stall.

[0110] Here, it is more preferable to configure the time for which the second motor generator assists the engine rotation to be longer as the remaining charge of the battery supplying power to the second motor generator increases and to be shorter as the remaining charge of the battery decreases. By configuring in this way, it is possible to effectively prevent the remaining charge of the battery from running out early.

[0111] Incidentally, the power assist for the combine harvester and the tractor may be configured to be performed by a motor that does not have a power generating function, instead of the second motor generator. [Explanation of symbols]

[0112] 1 Paddy field farming machine 2 Running vehicle 3. Mainframe 4. Belt-type power transmission mechanism 5 Lifting link device 6 Rear Frame 7 Engine 8 Front Wheel 9 Rear wheel 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 shift 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 shift lever 37 1st PTO gear 38 2nd PTO gear 39 Hydraulic Pump 40 DPF 42 Second Battery 43 Third Battery 45 Switching arm rotating shaft 47 Front cover 48 Cockpit 49 Control Department 51 Rear wheel gear case 56 Steering Wheel 59 Planting transmission shaft 60 Floor Step 63 Seedling Planting Department 64 Planting equipment 65 Seedling Tank 67 Drive shaft 69 Planting tools 70 Seedling outlet 71 Planting transmission part 72 Seedling transport 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 part 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 and store the generated electricity in the battery.

2. The paddy field working machine described in claim 1, characterized in that the generator is constituted by a motor generator that has a function as a generator and a function as 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. A working electric motor for driving the working machine is provided, The working 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 transport 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 or 2, characterized in that the seedling tank, the planting device, and the seedling feed belt are driven by the driving of the working electric motor.

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