JP7579522B2 - Paddy field farming machine - Google Patents

Description

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

Conventionally, paddy field working machines equipped with an engine as a power source for the machine body are 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 speed change mechanism such as a hydrostatic continuously variable transmission (so-called HST), and then transmitted to a running device including front and rear wheels, and to a working machine constituted by a seedling planting section.

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 creates the problem of high engine fuel consumption and exhaust gas emissions.

In response to this problem, Patent Document 2 describes how an electric motor is installed in place of an engine 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.

JP 2022-030945 A JP 2022-000724 A

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.

The present invention aims to provide a paddy field working machine that is configured to reduce fuel consumption and exhaust gas emissions while reducing the effort required by the operator to charge the battery that supplies power to the electric motor.

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;
an electric motor for driving the working machine;
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,
This is achieved by a paddy field working machine characterized in that the electricity generated by the generator when the engine is operating is stored in a battery that supplies power to the electric working motor.

According to the present invention, the agricultural work machine is configured to be driven by an electric motor, so the engine output can be reduced, 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 to the generator by the power distribution means from the transmission mechanism that transmits the rotational power output from the engine to the traveling device, and the electricity generated by this generator is stored in a battery that supplies power to the electric motor for work, reducing the effort required by the worker to charge the battery.

In a preferred embodiment of the present invention,
The traveling device includes a pair of left and right front wheels and a pair of left and right rear wheels,
The transmission mechanism includes a hydrostatic continuously variable transmission that receives rotational power output from the engine and changes speed;
a front gear case that changes the speed of the rotational power output from the hydrostatic continuously variable transmission and transmits the rotational power to a rear wheel drive shaft that transmits the rotational power to the pair of left and right front wheels and the pair of left and right rear wheels;
A pair of left and right rear wheel gear cases,
The rear-wheel drive shafts are a pair of left and right rear-wheel drive shafts, including a left rear-wheel drive shaft that transmits power to the left rear wheel and a right rear-wheel drive shaft that transmits power to the right rear wheel,
the pair of left and right rear wheel gear cases includes a left rear wheel gear case that receives rotational power from the left rear wheel drive shaft and transmits the rotational power to a left rear wheel, and a right rear wheel gear case that receives rotational power from the right rear wheel drive shaft and transmits the rotational power to a right rear wheel,
The batteries are housed in a single battery case;
the power distribution means distributes a portion of the rotational power transmitted from the pair of left and right rear wheel gear cases to the pair of left and right rear wheels to the generator;
The generators are a pair of left and right generators, including a left generator to which a portion of the rotational power transmitted to the left rear wheel is distributed, and a right generator to which a portion of the rotational power transmitted to the right rear wheel is distributed, and are configured to receive the rotational power distributed by the power distribution means and store the generated electricity in the battery.

According to this preferred embodiment of the present invention, the power changed in speed by the hydrostatic continuously variable transmission and the front gear case is transmitted to a pair of rear wheel gear cases through a pair of rear wheel drive shafts, and then transmitted from the pair of rear wheel gear cases to a pair of left and right rear wheels, and is also distributed to a pair of generators by a power distribution means, so that the pair of generators can generate electricity effectively, and a large amount of power can be obtained.

In addition, according to this preferred embodiment of the present invention, the power generated by the pair of generators is stored in a battery housed in a single battery case, so the power generated by the pair of generators can be combined into one, eliminating the need for a mechanism and control to switch the power source of the work electric motor between multiple battery cases.

In a further preferred embodiment of the present invention,
Each of the pair of left and right generators is composed of a motor generator that has both a generator function and an electric motor function, and is configured to transmit rotational power to the pair of left and right rear wheels through the power distribution means and the pair of left and right rear wheel gear cases when power is supplied from the battery.

In this preferred embodiment of the present invention, when the generated electricity is supplied from the battery that stores it to a generator formed by a motor generator, rotational power is transmitted to a pair of rear wheels, making EV driving possible.

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.

The present invention makes it 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.

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 a current flow 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 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 constituted by a tractor.

Below, a detailed description of a preferred embodiment of the present invention will be given with reference to the attached 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 is referred to as the "rear", the left side facing the forward 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".

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.

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 pilot's seat 48 provided above the floor step 60, a pilot's seat 49 for piloting 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".

The steering section 49 includes a main shift lever 35 that changes the forward/reverse movement and vehicle speed of the traveling body 2, a brake pedal 81 (see FIG. 2) that stops the traveling 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 FIG. 2) that will be described in detail later.

The steering mechanism 28 includes a steering wheel 56, 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 this transmission mechanism, an electric motor 18 that drives the seedling planting section 63, which is an example of the "work machine" of the present invention, and a first battery 17 that supplies power to this electric motor 18. The electric motor 18 corresponds to the "work electric motor" of the present invention.

The transmission mechanism 15 includes a belt-type power transmission mechanism 4 provided below the floor step 60 shown in FIG. 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 running 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.

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 in the HST 25 to a speed that corresponds to the operating position of the main shift lever 35, and the speed is 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 according to the operating position of the sub-shift lever 36. After that, part of the rotational power is 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 through a front wheel support part and a front wheel axle 31 that can change the steering direction, and is also transmitted to a pair of rear wheel 9 through a pair of rear wheel transmission shafts 14 composed of 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.

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

As a result, the rotors of the pair of first motor generators 33 are rotated to generate electricity. The pair of first motor generators 33 is an example of a "generator" of the present invention, but it is not necessarily necessary to use a motor generator as a 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 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 the input shaft to the first motor generator 33 so as to rotate integrally with the input shaft. Then, by wrapping an endless belt around the first pulley and the second pulley, when the engine 7 is operating, 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. Note that the power distribution means 32 may be configured as another distribution mechanism.

Meanwhile, the electricity generated by the left and right first motor generators 33 is stored in the first battery 17 that supplies 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 generator 33, the first battery 17 may be configured to be charged using a home charger or the like. This prevents work from being delayed in the unlikely event that the remaining battery charge of the first battery 17 becomes low.

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 continue. The clutch in the rear wheel gear case 51 is disconnected for the purpose of disconnecting the power transmission to the rear wheel 9 on the inside of the turn, for example, during turning. This allows the paddy field working machine 1 to turn smoothly and maneuverably.

The drive of the electric motor 18 is switched 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 configured as a DC motor, for example, the control unit 87 can be configured to turn the drive on and off by disconnecting the power supply to the electric motor 18 via a driver circuit based on the operation signal of the planting on/off switch 19.

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 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.

While the paddy field working machine 1 travels by the rotational drive of the running 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 performed simultaneously.

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

As shown in FIG. 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"), multiple 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 lined up in the front-to-rear direction (see FIG. 2).

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 the seedling tank 63 (moving it back and forth from side to side) 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 FIG. 2, a total of four rows of planting tools 69 are arranged in the left-right direction for 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 to operate the seedling planting section 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.

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, reducing the effort required for the operator to charge the first battery 17.

Meanwhile, in this embodiment, a power distribution means is extended from the planting transmission shaft 59 to the fertilizer transmission mechanism 21 so that power is transmitted to the fertilizer 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, rotational power is transmitted to the fertilizer application device 26 through this power distribution means and the fertilizer transmission mechanism 21. As a result, fertilizer is supplied to the field from the fertilizer hopper 26a of the fertilizer application device 26 through the fertilizer hose 26b. This power distribution means can be configured, for example, by a belt-type transmission mechanism, similar to the power distribution means 32.

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

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.

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.

In response to this, when the electronic hydraulic valve is controlled by the control unit 87 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.

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

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 (rotor) 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 arranged 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.

In FIG. 4, "7b" is a reference symbol for the cylinder block of the engine 7, "7c" is a reference symbol for each cylinder within the cylinder block 7c, and "7d" is a reference symbol for the timing gear case.

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 the batteries 42, 43 (see FIG. 6) described in detail later. When the engine 7 speed 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 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 speed drops.

Figure 5 is a graph that shows a schematic 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 rotation speed of the engine 7 drops significantly when making sharp turns (in other words, when making tight turns). To solve this problem, it is possible to configure the motor generator to assist the rotation of the engine, but constantly providing high assistance to the rotation of the engine will consume a lot of battery power.

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 assistance by the second motor generator 34 to be greater in accordance with the amount of 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 in accordance with the amount of 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 the second and third batteries 42, 43 described below as batteries that store the electricity generated by the second motor generator 34 and supply electricity to the second motor generator 34 when the second motor generator 34 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 of the batteries falls below a reference value, the control unit 87 assists the engine 7 by using the other battery as a power source for the second motor generator 34 when the engine 7 speed drops due to high load.

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

This increases the charging load and raises the temperature of the exhaust gas, allowing for efficient regeneration (combustion of soot) within the DPF 40. In addition, the load on the engine 7 is leveled out, improving fuel efficiency.

Here, if only one battery is charged from the motor generator that assists 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 this situation can be prevented. The second battery 42 and the third battery 43 are housed in separate battery cases (housings). It is also possible to configure the system so that the second motor generator 34 is driven to increase the load on the engine 7 instead of or in addition to charging the battery 42 or 43 with the low battery level. This allows the regeneration of the DPF 40 to be completed in a short time.

Furthermore, the control unit 87 is configured to actively (in other words, selectively) charge the battery 42 or 43 with the low 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 (combustion of soot) within the DPF 40. In addition, the load on the engine 7 is leveled out, 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-thredding, 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.

Figure 7 is a graph showing the relationship between the 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 that draws a normal torque curve and a green mode that draws 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. Then, when the engine 7 speed falls below a specified value while in the green mode, the control unit 87 drives the second motor generator 34 to assist the rotation of the engine 7.

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

Furthermore, in this embodiment, when the remaining battery charge measured from the output voltage of the second and third batteries 42, 43 falls below a first predetermined value while set in green mode, the mode is automatically switched from green mode to normal mode. Thereafter, when the remaining charge 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 mode automatically transitions (returns) to 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 charge becomes low, making it highly convenient.

4 to 7 can also be applied to a configuration in which the seedling planting section is driven by power transmitted from the 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 be automatically switched to the normal mode when the remaining charge of the second battery 42 falls below the 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 the 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 that 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 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 running wheels 8, 9 to a pair of first motor generators 33 (an example of a generator), and the electricity generated by the 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 the operator to charge the first battery 17. The first motor generator 33 on the left side is an example of the "left side generator" of the present invention, and the first motor generator 33 on the right side is an example of the "right side generator" of the present invention.

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 rear wheel drive shaft 14 and right rear wheel drive shaft 14), and then transmitted from the pair of rear wheel gear cases 51 to the left and right rear wheels 9, and is also distributed to a pair of first motor generators 33 by the power distribution means 32, so that the pair of first motor generators 33 can effectively generate electricity and obtain a large amount of power.

In addition, 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 power source of the electric motor 18 between multiple battery cases.

On the other hand, FIG. 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. In this embodiment, except for the points described below, it is configured in the same way as the paddy field working machine 1 according to the embodiment shown in FIG. 1 to FIG. 7, and therefore can achieve the same effects.

The second motor generator 34 for assisting the engine 7 in 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 engine 7 speed drops by a specified number or more 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 attach a motor generator to the generator section, drive the motor generator when the engine is assisting, 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.

In contrast, in this embodiment, the second motor generator 34 for assist is configured to transmit 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 eliminating the load on the timing belt 7f and lengthening its life.

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 breaks, preventing damage to the second motor generator 34.

The configuration shown in FIG. 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 operation.

On the other hand, FIG. 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 FIG. 9(a) being a schematic perspective view showing the engine 7 with a gear case 7g attached, and FIG. 9(b) being a schematic perspective view showing the engine 7 with the gear case 7g removed.

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

In this embodiment, except for the points described below, it is configured in the same way as the paddy field working machine 1 according to the embodiment shown in Figures 1 to 7, and therefore 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 position corresponds to the portion where a hydropump is attached and power is transmitted by gear drive. In addition, the second motor generator 34 can generate electricity, eliminating the need for a conventional generator without motor function. For this reason, a belt tensioner (tension pulley) 7s is attached to the portion of the engine 7 where a generator without motor function was attached in conventional paddy field working machines. This configuration makes it possible to use the same parts configuration as in the past (in other words, parts can be shared).

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 when the engine 7 speed drops below a specified number even though the accelerator opening is constant. 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, and the life of the timing belt 7f can be extended, similar to the embodiment shown in FIG. 8. In addition, it is possible to install a motor generator to assist the engine in a conventional paddy field working machine, without making any major changes to its shape.

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, too, the engine output can 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, it is preferable that the gear diameter of the idle gear 7m is three or more 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 outside the high-pressure pump 7h in the width direction of the engine 7, and the motor generator gear 7o is preferably positioned on the opposite side of 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 the breather assembly with heat insulation is disposed 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 the second motor generator 34 until the engine 7 is started.

The paddy field working machine 1 according to this embodiment is equipped with a starter motor that starts the engine 7, in addition to the second motor generator 34 that assists the engine 7. Then, when the starter motor is driven and stopped, if it is determined that the engine 7 rotation speed is below a predetermined value and the rotation speed has not increased 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 increased sufficiently. This allows the second motor generator 34 to assist the starting of the engine 7, which can prevent engine stall or sluggish starting after the starter motor is stopped, particularly at low temperatures, and allows the engine 7 to start smoothly.

The configurations shown in Figures 9 to 11 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 operation.

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 are also included within the scope of the present invention.

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 vehicle 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, which is composed of a belt-type power transmission mechanism or the like, and the running 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 work 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 fuel, the vehicle 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.

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 be configured to generate electricity using a generator that does not function as an electric motor.

Furthermore, the running 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, but may also include crawlers, etc.

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 speed within 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, it may be configured so that the power already changed in speed from the HST is electrically driven from the front gear case (which is further changed internally) to the vicinity between 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.

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 to drive an electric motor for work, thereby carrying out agricultural work.

Furthermore, in each embodiment shown in Figures 1 to 11, the 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, etc.

In addition, in each embodiment 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 be configured as a combine harvester, a 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 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, battery consumption can be reduced.

In addition, when the engine speed drops below a specified number and the second motor generator assists the engine, it is preferable to increase the amount of assistance by the second motor generator the more the amount of lumber in the grain tank. Generally, when making sharp turns, especially when there is a large amount of lumber, the engine speed can drop significantly, but by configuring in this way, it is possible to reduce the drop in speed and also suppress battery consumption when the amount of lumber is small.

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 towing mode is selected. During towing work, a large load is placed on 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 being performed, 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 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.

In addition, when the paddy field working machine is configured as a tractor, it is preferable to increase the amount of power assist by the second motor generator on the condition that the engine speed drops by a specified number or more 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 by limiting the increase in the amount of assist 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 FIG. 12, it is preferable to assist engine rotation by the second motor generator for several seconds from the time the rotary touches the ground (start of tilling) in conjunction with the "down" operation of the rotary lift switch that raises and lowers the rotary as the working machine. Since the load on the engine is large at the start of tilling immediately after the PTO is lowered and the rotary touches the ground, by configuring it in this way, it is possible to prevent deterioration of tilling characteristics and engine stall.

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 shorter as the remaining charge of the battery decreases. By configuring in this way, it is possible to effectively prevent the battery from running out of charge prematurely.

In addition, the power assist for combines and tractors may be configured to be performed by a motor without a power generating function instead of the second motor generator.

1 Paddy field working machine 2 Traveling vehicle 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 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 rotating shaft 47 Front cover 48 Pilot seat 49 Pilot 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 removal 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;
an electric motor for driving the working machine;
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 that supplies electric power to the work electric motor,
The traveling device includes a pair of left and right front wheels and a pair of left and right rear wheels,
The transmission mechanism includes a hydrostatic continuously variable transmission that receives rotational power output from the engine and changes speed;
a front gear case that changes the speed of the rotational power output from the hydrostatic continuously variable transmission and transmits the rotational power to a rear wheel drive shaft that transmits the rotational power to the pair of left and right front wheels and the pair of left and right rear wheels;
A pair of left and right rear wheel gear cases,
The rear-wheel drive shafts are a pair of left and right rear-wheel drive shafts, including a left rear-wheel drive shaft that transmits power to the left rear wheel and a right rear-wheel drive shaft that transmits power to the right rear wheel,
the pair of left and right rear wheel gear cases includes a left rear wheel gear case that receives rotational power from the left rear wheel drive shaft and transmits the rotational power to a left rear wheel, and a right rear wheel gear case that receives rotational power from the right rear wheel drive shaft and transmits the rotational power to a right rear wheel,
The batteries are housed in a single battery case;
the power distribution means distributes a portion of the rotational power transmitted from the pair of left and right rear wheel gear cases to the pair of left and right rear wheels to the generator;
The generators are a pair of left and right generators, comprising a left generator to which a portion of the rotational power transmitted to the left rear wheel is distributed, and a right generator to which a portion of the rotational power transmitted to the right rear wheel is distributed, and the paddy field working machine is configured to receive the rotational power distributed by the power distribution means and store the generated electricity in the battery. The paddy field working machine described in claim 1, characterized in that the pair of left and right generators are each composed of a motor generator that has both a generator function and an electric motor function, and when power is supplied from the battery , the power is transmitted to the pair of rear wheels through the power distribution means and the pair of rear wheel gear cases. 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.