JP7803390B2 - Paddy field farming machine - Google Patents

Description

The present invention relates to rice planters, combine harvesters, tractors, and other rice paddy farming machines capable of performing agricultural work in rice paddies.

Rice paddy farming machines equipped with engines as the power source for the machine have been widely known.

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 made up of a seedling planting unit.

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.

In response to this issue, Patent Document 2 describes how a paddy field working machine configured as a combine harvester is equipped with an electric motor, either in place of or in addition to an engine, as the power source for the traveling gear and working equipment. By using an electric motor as the power source, it is possible to eliminate or reduce engine fuel consumption and exhaust gas emissions.

Japanese Patent Application Laid-Open No. 2022-030945 Japanese Patent Application Laid-Open No. 2022-000724

However, when an electric motor is used as a power source for the travel device and/or work equipment, 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.

The present invention aims to provide a paddy field farming machine that is designed 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.

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 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.

According to the present invention, agricultural work machines are configured to be driven by electric motors, allowing engine output to be reduced, thereby reducing fuel consumption and exhaust gas emissions.

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

In a further preferred embodiment of the present invention,
The generator is composed of a motor generator that functions as 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 a pair of wheel gear cases when power is supplied from the battery.

In this preferred embodiment of the present invention, when 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, making EV driving possible.

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.

This invention makes it possible to provide a paddy field farming machine that is designed 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.

FIG. 1 is a schematic left side view of a paddy field working machine according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view of the paddy field working machine shown in FIG. FIG. 3 is a block diagram showing the flow of power in the paddy field working machine shown in FIG. FIG. 4 is a schematic plan view of the vicinity of the engine shown in FIG. FIG. 5 is a graph showing a schematic relationship between the rotation speed and the torque of the engine shown in FIG. 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. FIG. 7 is a graph showing the relationship between the rotation speed and torque of the engine shown in FIG. 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. 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. FIG. 10 is a schematic front view of the engine shown in FIG. 9 with the various gears exposed. FIG. 11 is a graph showing the relationship between the motor rotation speed and time when starting the engine shown in FIG. 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.

Below, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

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

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

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 as the "rear," and the left side of the forward direction of travel of the paddy field working machine 1 is referred to as the "left" and the opposite side as the "right."

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.

The traveling vehicle body 2 comprises a main frame 3 located approximately in the center of the vehicle body 2 in the width direction, 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 located above the floor step 60, a control unit 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".

The steering unit 49 includes a main speed change lever 35 that changes the forward/reverse movement and speed of the traveling vehicle body 2, a brake pedal 81 (see Figure 2) that stops the traveling vehicle body 2, a steering mechanism 28 including a steering wheel 56 that steers 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.

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).

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 the seedling planting section 63, which is an example of a "working 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 "working electric motor" of the present invention.

The transmission mechanism 15 includes a belt-type power transmission mechanism 4 located below the floor step 60 shown in FIG. 1; a hydrostatic continuously variable transmission (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 located on the left and right of the front gear case 30; a pair of left and right rear wheel gear cases 51 located to the left 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" in this invention.

The rotational power output from the engine 7 is transmitted to the HST 25 via the belt-type power transmission mechanism 4, and then within the HST 25, the speed is changed to a value 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 of the main frame 3.

The rotational power transmitted to the front gear case 30 is changed in speed inside the front gear case 30 depending on the operating position of the auxiliary speed change lever 36. A portion of the rotational power is then output to a pair of front wheel final cases 13, and from the front wheel final cases 13, it is transmitted to a pair of front wheels 8 via a front wheel support section and front wheel axles 31, which can change the steering direction, and to a pair of rear wheels 9 via a pair of rear wheel transmission shafts 14, which are composed of propeller shafts, 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.

Here, a portion of the rotational power transmitted to the left and right rear wheel gear cases 51 via 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).

As a result, the rotors of the pair of first motor-generators 33 are rotated, generating electricity. The pair of first motor-generators 33 are an example of a "generator" in the present invention, but it is not necessarily necessary to use a motor-generator as the generator.

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 the downstream portion of each rear wheel transmission shaft 14 (the rear portion of each rear wheel transmission shaft 14, located within the rear wheel gear case 51) so as to rotate integrally with the rear wheel transmission shaft 14. A second pulley is attached to the input shaft to the first motor-generator 33 so as to rotate integrally with the input shaft. An endless belt is then wound around the first and second pulleys. When the engine 7 is operating, the rotation of the rear wheel transmission shaft 14 rotates the first and second pulleys, the belt, and the input shaft to the first motor-generator 33. Note that the power distribution means 32 may also be configured with other distribution mechanisms.

Meanwhile, the electricity 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 operator's need to charge the first battery 17. The first battery 17 is housed in a single battery case (housing) 17a (see Figure 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 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 charge of the first battery 17 becomes low.

In this embodiment, a clutch that connects and disconnects power transmission is provided in the front gear case 30 and 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 to disconnect power transmission to the rear wheel 9 on the inside of the turn, for example, during turning. This allows the rice paddy farming implement 1 to make smooth, tight turns.

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

On the other hand, if the electric motor 18 is an AC motor, for example, by interposing an inverter between the first battery 17 and the electric motor 18, when an operation signal from 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 the 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.

While the paddy field working machine 1 travels by rotating 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 occur simultaneously.

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

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 a "seedling mat"), multiple planting devices 64 provided behind and below the seedling tank 65, and seedling feed belts 72 arranged in each row on the seedling tank 65. The multiple planting devices 64 are arranged in a line across the width of the paddy field working machine 1, and each planting device 64 comprises two pairs of left and right planting tools 69 aligned in the front-to-rear direction (see Figure 2).

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 lateral feed mechanism moves the seedling tank 63 back and forth in tandem 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 2008-182926 A and is a publicly known technology.

In this embodiment, as shown in Figure 2, a total of four rows of planting tools 69 are arranged side by side in a four-row planting configuration. Therefore, 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.

As described above, in this embodiment, the electric motor 18 is driven by power supplied from the first battery 17, operating the seedling planting unit 63. Therefore, compared to when the engine drives both the traveling device and the work machine, the output of the engine 7 can be reduced, thereby keeping the fuel consumption and exhaust gas emissions of the engine 7 low.

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

In contrast, in this embodiment, a power distribution means extends from the planting transmission shaft 59 to the fertilizer transmission mechanism 21 (see Figure 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 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 a belt-type transmission mechanism, similar to the power distribution means 32.

As shown in Figure 1, the seedling planting unit 63 is attached to the rear of the traveling vehicle body 2 so that it can rotate up and down via a lifting link device 5. The lifting link device 5 includes an upper link arm 85 and a pair of left and right lower link arms 86.

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.

When the control unit 87 controls the electronic hydraulic valve and hydraulically retracts the lifting hydraulic cylinder 12 shown in Figure 1, the upper link arm 85 rotates rearward and upward, raising the seedling planting unit 63 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.

In response to this, the control unit 87 controls the electronic hydraulic valve, and when 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.

Figure 4 is a schematic plan view of the vicinity of the engine 7 shown in Figure 1.

In this embodiment, the timing gear 7a in the engine 7 transmits the rotation of the crankshaft to the camshaft, and 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 (the rotor of) a second motor generator 34 that assists the rotation of the engine 7.

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.

In Figure 4, "7b" indicates the cylinder block of engine 7, "7c" indicates each cylinder within cylinder block 7c, and "7d" indicates the timing gear case.

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 Figure 6), which will be described in detail later. If the engine 7 rotation speed drops by more than a specified number even though the accelerator pedal position remains constant, the second motor generator 34 is configured to temporarily assist the rotation of the engine 7 using the electricity 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.

Figure 5 is a graph that schematically shows the relationship between the rotation speed and torque of the engine 7 shown in Figure 1.

Conventional rice paddy farming machines have a problem in that the engine 7 rotation speed drops significantly when making sharp turns (in other words, tight turns). To solve this problem, it is possible to configure the machine to assist engine rotation with a motor generator, but constantly providing significant assistance to engine rotation results in significant battery consumption.

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

As a result, when the paddy field working machine 1 makes sharp turns, the second motor-generator 34 can assist the rotation of the engine 7 while reducing battery consumption. The paddy field working machine 1 according to this embodiment is equipped with second and third batteries 42, 43, described below, which store the electricity generated by the second motor-generator 34 and supply power to the second motor-generator 34 when it is driven (during engine assistance).

Figure 6 is a schematic diagram showing the current flow between the second motor generator 34 and the second and third batteries 42, 43 shown in Figure 4.

The engine 7 in this embodiment is configured as a diesel engine and is equipped with a DPF (Diesel Particulate Filter) 40 that removes harmful substances from the exhaust gas.

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).

Specifically, when the remaining charge of one battery falls below a reference value, the control unit 87 uses the other battery as a power source for the second motor generator 34 to assist the engine 7 when the engine speed drops due to a high load.

Furthermore, 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 with the lowest remaining battery charge.

This increases the charging load and raises the temperature of the exhaust gas, allowing for efficient regeneration (burning of soot) within the DPF 40. It also equalizes the load on the engine 7, improving fuel efficiency.

However, if only one battery is charged by the motor generator assisting the engine, there is a problem in that charging cannot be performed when that battery is fully charged. In contrast, in this embodiment, second and third batteries 42, 43 are provided as destinations for power supplied from the motor generator, thereby preventing this situation. 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 with low battery charge, it is also possible to configure the system to drive the second motor generator 34 to increase the load on the engine 7. This allows regeneration of the DPF 40 to be completed in a short period of time.

Furthermore, the control unit 87 is configured to actively (in other words, selectively) charge the battery 42 or 43 with the lowest remaining battery charge during DPF active regeneration operation, which is performed when soot accumulates in the DPF 40 to a reference value or more.

This increases the charging load and raises the temperature of the exhaust gas, allowing for efficient regeneration (burning of soot) within the DPF 40. It also equalizes the load on the engine 7, improving fuel efficiency.

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-threshing, the exhaust temperature is low and passive regeneration of the DPF 40 cannot be performed. In such cases, it is desirable to configure the control unit to select and charge the battery with the lowest remaining battery charge.

Figure 7 is a graph showing the relationship between rotation speed and torque of the engine 7 shown in Figure 1.

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 that is 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 green mode and the engine speed falls below a specified value, the control unit 87 drives the second motor-generator 34 to assist the rotation of the engine 7.

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

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 green mode to 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 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.

The configurations shown in Figures 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. Additionally, the green mode configuration shown in Figure 7 can also be applied to a configuration in which only a second battery housed in a single battery case is used as the power source (electric power source) for the second motor generator 34. In this case, it is preferable to automatically switch from green mode to normal mode when the remaining charge of the second battery 42 falls below a first predetermined value, and then automatically switch (return) to green mode when the remaining battery charge reaches or exceeds a second predetermined value.

<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.

Furthermore, according to this embodiment, a portion of the power from a pair of rear wheel gear cases 51 of the transmission mechanism 15, which transmits the rotational power output from the engine 7 to the running 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 electricity generated by these first motor-generators 33 is stored in the first battery 17, which supplies power to the electric motor 18. This reduces the effort required of the operator to charge the first battery 17. The left-side first motor-generator 33 is an example of a "left-side generator" in the present invention, and the right-side first motor-generator 33 is an example of a "right-side generator" in the present invention.

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 via 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 distributed to a pair of first motor generators 33 by the power distribution means 32. This allows the pair of first motor generators 33 to generate electricity effectively, resulting in a large amount of power.

Furthermore, according to this embodiment, the electric power generated by the pair of first motor-generators 33 is stored in the first battery 17 housed in a single battery case 17a. This allows the electric power generated by the pair of first motor-generators 33 to be combined into one, eliminating the need for a mechanism and control to switch the electric motor 18's power source between multiple battery cases.

On the other hand, 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. 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.

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

In this way, by configuring the output to be extracted from the crank pulley 7e during regenerative driving, it becomes easier to position the second motor generator 34.

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 assisting, and transmit the output of the motor generator to the engine's timing belt. However, in this case, power is transmitted to a belt, which results in low transmission efficiency and a high load on the timing belt, shortening its lifespan.

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

In addition, 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, preventing damage to the second motor generator 34.

The configuration shown in Figure 8 can also be applied when the seedling planting section is driven by power transmitted from the engine, rather than by the electric motor 18 for work.

On the other hand, Figure 9 is a schematic perspective view showing the engine 7 of a paddy field working machine 1 according to yet another preferred embodiment of the present invention, with Figure 9(a) being a schematic perspective view showing the engine 7 with a gear case 7g attached, and Figure 9(b) being a schematic perspective view showing the engine 7 with the gear case 7g removed.

Also, Figure 10 is a simplified front view showing the various gears of the engine 7 shown in Figure 9.

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.

The second motor-generator 34 for assisting the engine 7 in 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 hydro pump 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. For this reason, a belt tensioner (tension pulley) 7s is installed in the part of 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 conventional machines (in other words, parts can be shared).

When the engine 7 rotation speed drops by more than a specified number even though the accelerator opening is constant, the power output from the second motor generator 34 is transmitted to the engine 7 side via the gear train 7k, which drives the valves. In other words, the gear train 7k is driven by the second motor generator 34.

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, as in the embodiment shown in Figure 8, and the life of the timing belt 7f can be extended. 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.

Furthermore, by sharing the gear train 7k with the balancer drive, the second motor generator 34 can be positioned compactly. Note that a motor without power generation function can also be installed in place of the second motor generator 34. In this case, the engine output can still be assisted by the motor.

In this embodiment, if abnormal combustion (overrun) occurs in the engine 7, deceleration is performed using the torque of the second motor-generator 34.

As shown in FIG. 10, the gear diameter of the idle gear 7m is preferably at least three times larger than that of the crank gear 7n, the motor generator gear 7o is preferably positioned below the high-pressure pump gear 7q, the motor generator gear 7o is preferably positioned above the crank gear 7n, the motor generator gear 7o is preferably positioned outward in the width direction of the engine 7 than the high-pressure pump 7h, and the motor generator gear 7o is preferably positioned on the side opposite the cam gear 7p. Note that "7r" in FIG. 10 is the symbol for the oil pump gear.

In addition, in this embodiment, the DPF 40 is disposed horizontally above the engine 7, and a breather assembly with heat insulation is located rearward of the rear end of the rear plate.

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

The paddy field working machine 1 according to this embodiment is equipped with a second motor-generator 34 that assists the engine 7, as well as a starter motor that starts the engine 7. If the engine 7 rotation speed 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 engine 7 rotation speed 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, preventing engine stalling or sluggish starting after the starter motor is stopped, particularly at low temperatures, and ensuring a smooth start of the engine 7.

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

The present invention is not limited to the above 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 encompassed within the scope of the present invention.

For example, in each embodiment shown in Figures 1 through 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 implements such as the seedling planting unit 63 and the fertilizer applicator 26, for example, when the implement is not traveling. In this case, the motor-generator 33 serves as both a "generator" and a "working electric motor" in the present invention. Furthermore, the first motor-generator 33 may be driven, and power transmitted (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 and 9 via the rear wheel gear case 51 and the rear wheel axle 82. In this case, the paddy field implement 1 can be driven in electric vehicle mode by the motor-generator 33, without operating the engine 7, using rear-wheel drive, thereby preventing exhaust gas emissions. In addition, the implement can continue traveling even if the engine 7 stops due to lack of fuel. In this case, 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, or power transmission to the pair of front wheels 8 may be interrupted.

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.

Furthermore, although the traveling gear of the paddy field working machine 1 in each embodiment shown in Figures 1 to 11 includes front wheels 8 and rear wheels 9, it may also include crawlers or the like.

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-transmission lever 36, and then transmitted to the left and right rear wheels 9 via a pair of rear wheel transmission shafts and a pair of rear wheel gear cases 51. However, for example, the power may be configured so that it is 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 via a single propeller shaft, and then transmitted to the left and right rear wheels via a differential mechanism located between the left and right rear wheels.

In this case, a power distribution means such as a belt can be placed on a single propeller shaft or on the rear wheel axles extending to the left and right from the differential mechanism, and power can be distributed to a generator or motor generator, allowing power transmitted from the engine to generate electricity and drive an electric motor for agricultural work.

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 power distribution means to a generator that does not function as a motor-generator or electric motor may also 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.

In addition, 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, tractor, etc.

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 even more preferable to increase the amount of power assist provided by the second motor generator when the engine speed drops by more than a specified number and the cutting unit is in operation. This reduces the drop in rotation speed during cutting work, improving workability, and by limiting the increase in the amount of assistance to cutting work, battery consumption can be reduced.

Furthermore, 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 provided by the second motor-generator the greater the amount of fuel in the fuel tank. Generally, when making sharp turns, engine speed can drop significantly, especially when there is a large amount of fuel. However, by configuring in this way, it is possible to reduce the drop in speed and also reduce battery consumption when there is a small amount of fuel.

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 even more preferable to increase the amount of power assist provided that 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 from the second motor generator, workability can be improved. In addition, by limiting the increase in the amount of assistance provided by the second motor generator to towing work, battery consumption can be reduced.

In addition, when the paddy field working machine is configured as a tractor, it is preferable to assist engine rotation with the second motor generator when the engine speed drops by more than a specified number even when the engine accelerator opening 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.

Furthermore, when the paddy field working machine is configured as a tractor, it is preferable to increase the amount of power assist provided by the second motor generator on the condition that the engine speed drops by more than a specified number within a predetermined time after the working machine lifting lever is moved to the lowered 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 assistance to when the machine touches the ground, battery consumption can be reduced.

Furthermore, when the paddy field working machine is configured as a tractor, as shown in Figure 12, it is preferable to assist engine rotation with the second motor generator for several seconds after 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. Because the load on the engine is heavy when plowing 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.

Here, it is more preferable to configure the time for which the second motor generator assists engine rotation so that it is longer the greater the remaining battery charge that supplies power to the second motor generator, and shorter the shorter the remaining battery charge. This configuration effectively prevents the battery from running out of power prematurely.

In addition, the power assistance for combines and tractors may be configured to be performed by a motor without power generation capabilities instead of the second motor generator.

1 Paddy field working machine 2 Traveling body 3 Main frame 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 arm 12 Lifting hydraulic cylinder 13 Front wheel final case 14 Rear wheel transmission shaft 15 Power transmission mechanism 17 Battery 18 Electric motor 19 Planting on/off switch 21 Fertilization transmission mechanism 23 Green mode switch 24 Sub-speed change lever 25 HST
26 Fertilizer applicator 27 Planting clutch motor 28 Steering mechanism 30 Transmission case 31 Front wheel axle 32 Power distribution means 33 First motor generator 34 Second motor generator 35 Main shift lever 36 Sub-shift lever 37 First 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 section
51 Rear wheel gear case 56 Steering wheel 59 Planting transmission shaft 60 Floor step 63 Seedling planting section 64 Planting device 65 Seedling tank 67 Drive shaft 69 Planting tool 70 Seedling take-out port 71 Planting transmission section 72 Seedling feed belt 79 SS lever 81 Brake pedal 82 Rear wheel axle 83 Steering post 85 Upper link arm 86 Lower link arm 87 Control section

Claims (3)

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; 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. 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 or 2, characterized in that the seedling tank, the planting device, and the seedling feed belt are driven by the working electric motor.