Work vehicles

Abstract

To provide a work vehicle which enables reduction of fuel consumption and inhibits emission of exhaust gas.SOLUTION: A work vehicle according to one aspect of an embodiment includes: an engine; a transmission mechanism; a power generator; a battery; a working motor; and a work machine. The transmission mechanism transmits power generated by the engine to wheels. The power generator generates electric power by the power generated by the engine. The battery is charged by the electric power generated by the power generator. The working motor is supplied with electric power from the battery to be driven. The work machine is driven by the power generated by the working motor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] BACKGROUND ART Conventionally, a work vehicle that rocks a work implement for performing work in a farm field has been known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-222604 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned work vehicle, power generated by an engine is transmitted to the drive wheels and the work vehicle. There is room for improvement in the electrification of the above-mentioned work vehicle.

[0005] The present invention has been made in view of the above, and has an object to provide a work vehicle that reduces fuel consumption and suppresses exhaust gas emissions. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a work vehicle (1) according to one aspect of the embodiment includes an engine (30), a transmission mechanism (11a, 13, 42) that transmits power generated by the engine (30) to wheels (11), a generator (115) that generates power using the power generated by the engine (30), a battery (116) that is charged with the power generated by the generator (115), a work motor (117) that is driven by power supplied from the battery (116), and a work implement (4) that is driven by the power generated by the work motor (117). The generator (115) is a motor generator, and the work motor (117) is not driven when the work implement (4) is not driven, and the generator (115) functions as a motor that drives the rear wheels (11) when the work implement (4) is not driven. The generator (4) includes a first motor generator (115) that can drive the left rear wheel (11) and a second motor generator (115) that can drive the right rear wheel (11). Of the first motor generator (115) and the second motor generator (115), the motor generator on the inside of a turn generates electricity during turning, and the motor generator on the outside of a turn drives the rear wheel (11) on the outside of a turn during turning. [Effects of the Invention]

[0007] According to one aspect of the embodiment, the work vehicle can reduce fuel consumption and suppress exhaust gas emissions. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a work vehicle. [Figure 2] FIG. 2 is a diagram showing an outline of a power (electric power) transmission path of a work vehicle. [Figure 3] FIG. 3 is a diagram showing details of the power (electric power) transmission path of the work vehicle. [Figure 4] FIG. 4 is a block diagram showing a control system centered on the control device of the seedling transplanter. [Figure 5] FIG. 5 is a flowchart illustrating the driving process of the work motor according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating power transmission in a seedling transplanter according to a modified example. [Figure 7] FIG. 7 is a diagram illustrating a power generation mechanism of a work vehicle according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] A work vehicle 1 according to an embodiment will be described with reference to Figures 1 to 3. Figure 1 is a side view showing the work vehicle 1. Figure 2 is a diagram showing an outline of the power (electricity) transmission path of the work vehicle 1. Figure 3 is a diagram showing the details of the power (electricity) transmission path of the work vehicle 1.

[0010] In the following description, the forward / rearward direction refers to the direction of travel of the work vehicle 1 when traveling straight, with the front side of the traveling direction being defined as "front" and the rear side being defined as "rear." The traveling direction of the work vehicle 1 is the direction from the driver's seat 41 toward the handlebars 35 (steering device) when traveling straight (see Figures 1 and 2).

[0011] The left-right direction is a direction that is horizontally perpendicular to the front-rear direction and defines left and right facing the "front." In other words, when the operator (also referred to as an operator) is seated in the operator's seat 41 and facing forward, the left-hand side is the "left" and the right-hand side is the "right."

[0012] The up-down direction is the vertical direction. The front-rear direction, left-right direction, and up-down direction are perpendicular to each other. Each direction is defined for the convenience of explanation, and the present invention is not limited to these directions.

[0013] In the embodiment, the work vehicle 1 is described as a riding seedling transplanter 1 that is equipped with a seedling planting unit 4 (working machine) as a field work device and that receives seedlings in a field. As shown in Figure 1, the seedling transplanter 1 is equipped with the seedling planting unit 4 that can be raised and lowered via a lifting link mechanism 3 on the rear side of the traveling body 2 to plant seedlings in the field.

[0014] The main body of the fertilizer applicator 5 is disposed on the upper rear side of the traveling vehicle body 2.

[0015] The traveling vehicle body 2 is a four-wheel drive vehicle equipped with left and right front wheels 10, which are wheels and drive wheels, and rear wheels 11. On the front side of a main frame 15 that constitutes the body skeleton of the traveling vehicle body 2, there are provided a transmission case 13 (transmission mechanism) that transmits driving force to the front wheels 10 and rear wheels 11, etc., and a hydraulic continuously variable transmission 14 that outputs driving force supplied from an engine 30, i.e., rotation generated by the engine 30, to the transmission case 13.

[0016] The continuously variable transmission 14 is a hydrostatic continuously variable transmission known as an HST (Hydro Static Transmission). In the following, a case where the continuously variable transmission is the HST 14 will be described.

[0017] The transmission case 13 accommodates an auxiliary transmission mechanism 16, a front wheel differential device 110, and a rear wheel differential device 111. The auxiliary transmission mechanism 16 switches the driving mode of the traveling vehicle body 2 between high-speed mode when traveling on roads and low-speed mode when planting seedlings.

[0018] Front wheel gear cases 10a are provided on the left and right sides of the transmission case 13, and front wheels 10 are attached to left and right front wheel axles 10b that protrude outward from front wheel support parts that can change the steering direction of the left and right front wheel gear cases 10a. The power transmitted to the transmission case 13 is transmitted to the front axle 113a, vertical shaft 113b, rotating horizontal shaft 113c, front wheel axles 10b, and front wheels 10 via the auxiliary transmission mechanism 16 and the front wheel differential device 110.

[0019] In addition, rear wheel gear cases 11a (transmission mechanism) are attached to both the left and right sides of the rear frame, which is arranged laterally on the rear side of the main frame 15, and rear wheels 11 are attached to left and right rear wheel axles 11b that protrude outward from the rear wheel gear cases 11a, respectively.

[0020] Left and right drive shafts 42 (transmission mechanisms) are provided at the rear of the transmission case 13. The power transmitted to the transmission case 13 is transmitted to the left and right rear wheel gear cases 11a via the auxiliary transmission mechanism 16, the rear wheel differential device 111, and the drive shafts 42.

[0021] The rear wheel gear case 11a has left and right rear wheel input shafts 114a, left and right rear wheel transmission shafts 114b, and left and right rear wheel axles 11b. The left and right rear wheel input shafts 114a receive rotational power from the engine 30 via the corresponding left and right drive shafts 42. The power transmitted to the rear wheel gear case 11a is then transmitted to the rear wheel input shafts 114a, rear wheel transmission shafts 114b, rear wheel axles 11b, and rear wheels 11.

[0022] A side clutch 44 that turns on and off the power transmission to the left and right drive shafts 42 is disposed upstream of the left and right drive shafts 42 in the power transmission direction. As shown in Figure 1, a side clutch pedal 43a that turns on and off the left and right side clutches 44 is provided at the front lower part of the cockpit 41 and on one of the left and right sides.

[0023] Of the left and right side clutch pedals 43a, when the side clutch pedal 43a on the inside of the turn is depressed to turn off the side clutch 44, and then the steering wheel 35 is operated to turn, the driving rotation from the engine 30 to the rear wheel 11 on the inside of the turn can be completely cut off.

[0024] Left and right motor generators 115 are provided near the rear wheel gear case 11a. The left and right motor generators 115 generate electricity using power generated by the engine 30. The left and right motor generators 115 receive power generated by the engine 30 via left and right rear wheel transmission shafts 114b. The left motor generator 115 receives power via the left rear wheel transmission shaft 114b. The right motor generator 115 receives power via the right rear wheel transmission shaft 114b. A clutch may be provided between the motor generator 115 and the rear wheel transmission shaft 114b to switch power transmission between the motor generator 115 and the rear wheel transmission shaft 114b. Because the rotation of the rear wheel transmission shaft 114b is transmitted to the motor generator 115, the speed of rotation input to the rotary shaft of the motor generator 115 becomes relatively high.

[0025] The electric power generated by the left and right motor generators 115 is stored in the battery 116. That is, the battery 116 is charged with the electric power generated by the left and right motor generators 115. The battery 116 is, for example, a lithium ion battery.

[0026] Furthermore, left and right link support frames 23 that support the lifting link mechanism 3 protrude upward from the upper part of the rear frame. A pair of left and right lower link arms 24 are provided below and between the left and right link support frames 23. A hydraulically operated lifting cylinder 25 is provided between the left and right lower link arms 24.

[0027] An upper link arm 26 is provided above the lifting cylinder 25, forming a parallel link mechanism, the lifting link mechanism 3. The left and right lower link arms 24, the lifting cylinder 25, and the other end of the upper link arm 26, each of which has one end connected to the traveling vehicle body 2, are attached to the front of the seedling planting section 4.

[0028] An engine 30 is mounted on the main frame 15. Rotational power of the engine 30 is transmitted to the transmission case 13 via the belt transmission device 21 and the HST 14. The rotational power transmitted to the transmission case 13 is changed in speed by the sub-transmission mechanism 16 inside the transmission case 13.

[0029] The rotational power of the engine 30 is transmitted to a hydraulic pump (not shown). The hydraulic pressure generated by the hydraulic pump is supplied to the HST 14, a power steering mechanism 88 (see FIG. 4) of the handle 35, the lift cylinder 25, etc.

[0030] A bonnet 39 with an operation panel 38 arranged on top for operating each section is provided on the upper front side of the traveling vehicle body 2. The operation panel 38 is provided with a monitor 86 (see FIG. 4) and the like.

[0031] The bonnet 39 is also provided with a handle 35 for steering the vehicle body 2, a speed change operation lever 36 for operating the HST 14, an auxiliary speed change operation lever 37 for operating the auxiliary transmission mechanism 16 (see FIG. 4), and the like.

[0032] An openable front cover 40 is provided in front of the hood 39. Inside the front cover 40, a fuel tank, a battery 116, and an interlocking mechanism that rotates the left and right front wheels 10 and the lower sides of the left and right front wheel gear cases 10a in response to steering of the handlebars 35 are provided. The front wheels 10 are, for example, steered wheels that turn in response to steering of the handlebars 35.

[0033] An engine cover 30a that covers the top and sides of the engine 30 is provided behind the hood 39 and above the engine 30, and a pilot's seat 41 where the pilot sits is provided above the engine cover 30a.

[0034] The fertilizer applicator 5 is provided behind the driver's seat 41, at the rear end of the main frame 15. The driving force of the fertilizer applicator 5 is transmitted by a fertilizer transmission mechanism provided so as to face the fertilizer applicator 5 from one of the left and right rear wheel gear cases 11a.

[0035] Approximately horizontal floor steps 33 are formed on both the left and right sides of the lower part of the engine cover 30a and the hood 39. Part of the floor step 33 is lattice-shaped, so that even if mud gets on the shoes of an operator walking on the floor step 33, the mud will fall into the field.

[0036] A rear step is connected to the rear of the floor step 33. The surface of the rear step is preferably provided with an anti-slip finish, for example, with a pattern of multiple projections, to prevent feet from slipping during work.

[0037] In addition, on the front side of the traveling body 2 and on both the left and right sides, spare seedling frames 50 are provided, each with a seedling frame support 51 on which multiple spare seedling loading tables 52 are arranged at intervals in the vertical direction, so that work materials such as seedlings and fertilizer bags to be replenished in the seedling planting section 4 can be placed.

[0038] Additionally, a seedling planting unit 4 is provided at the rear end of the lifting link mechanism 3. Specifically, a seedling tank 53 for loading seedlings to be planted in the field is attached to the rear end of the lifting link mechanism 3, along with a sliding mechanism for sliding it left and right. Seedling partition fences that are long in the vertical direction are placed on the seedling tank 53 at predetermined intervals left and right. Below the seedling tank 53 is a seedling planting device 55 that picks up the loaded seedlings and plants them in the field.

[0039] The seedling planting device 55 plants eight rows at the same time, the same number as the number of rows to be planted separated by the seedling partition fence. Four planting transmission cases 56 are arranged at intervals below the seedling tank 53, and planting rotaries 57 are attached to both the left and right sides of the planting transmission cases 56, which rotate to pick up seedlings using planting rods 58 and plant them in the field.

[0040] The seedling planting section 4 is driven by a working motor 117. For example, the planting rotary 57 is driven by the power generated by the working motor 117. The working motor 117 is supplied with power from a battery 116. Multiple working motors 117 are provided. Multiple working motors 117 are provided according to the driving positions in the seedling planting section 4.

[0041] In the fertilizer applicator 5, the fertilizer hopper 70 that stores the fertilizer is divided into the same number of sections as the number of working rows in the seedling planting section 4 (eight rows in the example shown in FIG. 2). Note that the eight-row fertilizer hopper 70 is long in the left-right direction, which reduces the convenience of adding fertilizer and attaching and detaching it, so it may have a so-called side fertilizer application structure, in which sections divided into four rows are lined up on each side.

[0042] Below the fertilizer hopper 70, a dispensing device 71 that supplies a set amount of fertilizer is provided for each row. Below the dispensing device 71, a ventilation duct 72 is provided in the left-right direction, through which conveying air passes to move the fertilizer. Below the dispensing device 71, a fertilizer hose 73 is provided to guide the fertilizer near the seedling planting position in the seedling planting section 4. Also, at one end of the ventilation duct 72, a blower 74 that is operated by an electric blower motor 76 to generate conveying air is provided.

[0043] As shown in Figure 1, a center float 62C that slides on the field surface and two side floats 62L and 62R are provided below the seedling planting section 4 and are rotatable about axes. Note that the center float 62C and the left and right side floats 62L and 62R may be collectively referred to as floats 62.

[0044] In addition, below the seedling planting section 4, and forward of the float 62, a ground leveling rotor 63 for leveling unevenness in the field is provided. Driving force is transmitted to the ground leveling rotor 63 from the rear wheel gear case 11a on the other left or right side via a rotor transmission shaft 63a.

[0045] 1, line-drawing markers 65 are provided on both the left and right sides of the seedling planting section 4. One of the markers 65 touches the ground on the field surface to form a groove that serves as a guide for traveling in the next work row (next process). When one of the markers 65 touches the ground, the other moves upward, and when the seedling planting section 4 is raised during rotation, both the left and right sides move upward, and when the seedling planting section 4 is lowered after rotation, one of the markers 65 moves upward and the other moves downward.

[0046] 1, a center mascot 66 that is long in the vertical direction is provided in the center of the left and right of the traveling vehicle body 2, in front of the hood 39. By aligning the center mascot 66 with the grooves formed in the field by the left and right line markers 65, it becomes possible to travel in accordance with the work position of the previous work row, improving work accuracy and preventing non-working.

[0047] Depending on the soil quality of the field, the guide lines formed by the left and right line-drawing markers 65 may quickly become buried, causing the guide for going straight to disappear. In such cases, it is advisable to use the left and right side markers 19, which are located forward of the left and right line-drawing markers 65. In other words, by moving the left and right side markers 19 outward and positioning them above the planted seedlings, planting work can be performed in accordance with the planting of the seedlings in the previous work row.

[0048] As shown in FIG. 1, the seedling transplanter 1 is also equipped with a position acquisition device 150. The position acquisition device 150 acquires the current position and orientation of the seedling transplanter 1. The position acquisition device 150 includes, for example, an orientation sensor and a positioning means such as a Global Positioning System (GPS) or a Global Navigation Satellite System (GNSS). The position acquisition device 150 may be composed of multiple devices. The position acquisition device 150 may include a camera or an ultrasonic sensor, and may acquire a turning position in the field and detect the distance to the turning position.

[0049] For example, the position acquisition device 150 receives positioning information from a positioning means, creates current position information and direction information of the traveling vehicle body 2 based on the received positioning information, and acquires the current position and direction. The position acquisition device 150 is attached to the mounting stay 59, for example, and disposed above the traveling vehicle body 2.

[0050] A straight-line control program and a turning control program, which are created based on position information from position acquisition device 150, are stored in different locations. The straight-line control program is stored, for example, in a straight-line control ECU (Electronic Control Unit) 100a in position acquisition device 150, and the turning control program is stored, for example, in a turning control ECU 100b housed in hood 39. Note that straight-line control ECU 100a and turning control ECU 100b are included in control device 100 (see FIG. 3), which will be described later. Straight-line control ECU 100a and turning control ECU 100b may be stored in the same ECU.

[0051] Next, the control system of the seedling transplanter 1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the control system centered on the control device 100 of the seedling transplanter 1. The seedling transplanter 1 is capable of controlling each part by electronic control, and is equipped with a control device (hereinafter referred to as a controller) 100 that controls each part.

[0052] The controller 100 is a computer. The controller 100 is provided with a processing unit having a CPU (Central Processing Unit) and the like, a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an input / output unit, which are interconnected and capable of transmitting and receiving signals between them. The storage unit stores computer programs and the like for controlling the seedling transplanter 1. The controller 100 performs each function by reading out the computer programs and the like stored in the storage unit.

[0053] The controller 100 is connected to actuators such as a throttle motor 80, hydraulic control valves 81, 82, a planting clutch actuation solenoid 83, a side clutch actuation solenoid 84, an HST motor 85, a line drawing marker lifting motor 87, a steering motor 95, and a work motor 117.

[0054] The throttle motor 80 increases or decreases the rotation speed of the output shaft of the engine 30 by operating a throttle that adjusts the amount of air intake into the engine 30. The hydraulic control valve 81 controls the extension and retraction of the lift cylinder 25. The hydraulic control valve 82 controls the power steering mechanism 88. The planting clutch operating solenoid 83 operates the planting clutch 27a.

[0055] The side clutch actuation solenoid 84 actuates the side clutch 44, which switches the state of power transmission to the rear wheels 11 (see FIG. 1). The side clutch 44 is provided on each of the left and right rear wheels 11, and two side clutch actuation solenoids 84 are provided corresponding to each side clutch 44.

[0056] The HST motor 85 changes the rotation angle of the trunnion of the HST 14, thereby changing the tilt angle of the swash plate of the HST 14. The steering motor 95 is a motor that drives the handle 35, which is a steering device that adjusts the steering amount (steering angle) of the front wheels 10 (see Figure 1) when automatic turning control is performed. The steering motor 95 rotates the handle 35. The line drawing marker lifting motor 87 lifts and lowers the line drawing marker 65.

[0057] The controller 100 is connected to detection devices such as a rotation speed sensor 90, a steering amount sensor 91, and a voltage sensor 92. Two rotation speed sensors 90 are provided corresponding to the left and right rear wheels 11, and detect the rotation speeds of the left and right rear wheels 11, respectively. Note that the rotation speed sensors 90 may also detect the rotation speeds of the left and right front wheels 10.

[0058] The steering amount sensor 91 detects the amount of operation of the steering wheel 35, which is a steering device, i.e., the steering amount (steering angle) of the front wheels 10. The steering amount sensor 91 is provided, for example, on a shaft connected to a pitman arm. The steering amount is detected in both the left and right directions, with the value when the steering wheel 35 is in a preset straight-ahead position being used as a reference value.

[0059] The voltage sensor 92 detects the remaining charge of the battery 116. Note that the remaining charge of the battery 116 may be detected by a current sensor, or may be calculated based on values ​​detected by the voltage sensor 92 and the current sensor.

[0060] In addition, signals are input to the controller 100 as operation signals from the speed change operation lever 36, the auxiliary speed change operation lever 37, the autonomous driving switch 46, the planting section lifting / lowering switch 47, the automatic straight-line movement switch 45, the automatic turning switch 48, the line drawing marker automatic lifting / lowering switch 49, etc.

[0061] The autonomous driving selector switch 46 is a switch that switches whether autonomous driving is performed. Specifically, the autonomous driving selector switch 46 is a switch that switches the driving mode between the autonomous driving mode and the manual driving mode. For example, when the autonomous driving selector switch 46 is "ON," the driving mode is set to the autonomous driving mode. When the autonomous driving selector switch 46 is "OFF," the driving mode is set to the manual driving mode. When the autonomous driving selector switch 46 is turned "ON," the automatic straight driving selector switch 45 and the automatic turning selector switch 48 are turned "ON." In other words, once the driving mode is set to the autonomous driving mode, the automatic straight driving selector switch 45 and the automatic turning selector switch 48 can be changed to "OFF" by the operator, even if they have been turned "ON" once.

[0062] The planting section lifting / lowering switch 47 is a switch that switches whether to lift or lower the seedling planting section 4. The planting section lifting / lowering switch 47 can be changed to the "up" and "down" positions.

[0063] When the planting unit lift switch 47 is in the "up" position, the seedling planting unit 4 rises to a predetermined non-working position and the seedling planting device 55 stops, putting it into a non-working state. When the planting unit lift switch 47 is in the "down" position, the seedling planting unit 4 descends to a predetermined working position and the seedling planting device 55 operates, putting it into a working state. In other words, the planting unit lift switch 47 is a switch that detects the working state of the seedling planting unit 4. Note that a separate switch that detects the working state of the seedling planting unit 4 may also be provided.

[0064] The automatic line drawing marker lifting / lowering switch 49 is a switch that switches whether or not the line drawing marker 65 is automatically lifted / lowered in conjunction with the amount of operation of the handlebars 35, i.e., the amount of steering of the front wheels 10. When the automatic line drawing marker lifting / lowering switch 49 is "ON," control is executed to automatically lift / lower the line drawing marker 65 in conjunction with the amount of steering. On the other hand, when the automatic line drawing marker lifting / lowering switch 49 is "OFF," control is not executed to automatically lift / lower the line drawing marker 65 in conjunction with the amount of steering.

[0065] The automatic straight-line driving selector switch 45 is a switch that switches whether or not automatic straight-line driving is enabled. When the automatic straight-line driving selector switch 45 is set to "ON," the driving assist function is enabled, and automatic straight-line driving can be performed. When the automatic straight-line driving selector switch 45 is set to "OFF," the driving assist function is disabled, and automatic straight-line driving cannot be performed.

[0066] When the travel assist function is enabled and automatic straight-line driving is performed, the traveling vehicle body 2 travels straight without the driver's operation while the seedling planting unit 4 plants seedlings in the field. In automatic straight-line driving, the steering motor 95 is controlled so that the traveling vehicle body 2 travels straight along a preset straight-line route.

[0067] The automatic turning selector switch 48 is a switch that switches whether or not automatic turning is enabled. When the automatic turning selector switch 48 is set to "ON," the turning assist function is enabled, and automatic turning can be performed. When the automatic turning selector switch 48 is set to "OFF," the turning assist function is disabled, and automatic turning cannot be performed.

[0068] When the turning assist function is enabled and automatic turning is performed, the seedling planting unit 4 stops planting seedlings, and the steering motor 95 is controlled to turn the traveling body 2 so that the traveling body 2 follows a preset turning path. When automatic turning is performed, the seedling planting unit 4 rises and enters a non-working state.

[0069] The controller 100 receives input of information such as the current position of the traveling vehicle body 2 from the position acquisition device 150.

[0070] Various information may be input to the controller 100 from a remote control device 170 (hereinafter referred to as "remote control"). The remote control 170 can remotely control the seedling transplanter 1. The remote control 170 may be a terminal device such as a smartphone. The remote control 170 transmits control signals in response to operations by an operator. The remote control 170 is communicably connected to the controller 100 via short-range wireless communication such as Wi-fi (registered trademark) or BLE (Bluetooth (registered trademark) Low Energy), but is not limited thereto, and may be communicably connected via a communication network or the like in addition to or instead of short-range wireless communication.

[0071] The controller 100 controls the motor generator 115. The controller 100 causes the motor generator 115 to function as a generator, and causes the motor generator 115 to generate electricity using power generated by the engine 30, thereby charging the battery 116. For example, when driving the work motor 117, the controller 100 causes the motor generator 115 to function as a generator, and charges the battery 116.

[0072] Furthermore, when the traveling vehicle body 2 decelerates, the controller 100 causes the motor generator 115 to function as a generator to generate electricity and charge the battery 116. In other words, when the traveling vehicle body 2 decelerates, the controller 100 charges the battery 116 with regenerative power.

[0073] Furthermore, the controller 100 causes the motor generator 115 to function as a motor, and drives the rear wheels 11 using the electric power stored in the battery 116. For example, when the work motor 117 is not driven, the controller 100 supplies electric power from the battery 116 to the motor generator 115, and causes the motor generator 115 to generate power. The power generated by the motor generator 115 is transmitted to the rear wheels 11 via the rear wheel transmission shaft 114b and the rear wheel axle 11b. In this case, the side clutch 44 is disengaged (disengaged), and the power generated by the engine 30 is not transmitted to the rear wheels 11. For example, when the traveling body 2 is turning to head for the next process in a farm field, the controller 100 does not drive the work motor 117, and causes the motor generator 115 to drive the rear wheels 11.

[0074] When driving the seedling planting device 55, i.e., when putting the seedling planting unit 4 into a working state, the controller 100 drives the work motor 117. The controller 100 drives the work motor 117 with power supplied from the battery 116. For example, when the planting unit lift switch 47 is in the "down" position, the controller 100 drives the work motor 117. Furthermore, when the driving assist function is enabled and automatic straight-line driving is to be performed, the controller 100 drives the work motor 117.

[0075] The controller 100 stops the work motor 117 when the seedling planting device 55 is not driven, i.e., when the seedling planting unit 4 is in a non-working state. For example, the controller 100 does not drive the work motor 117 when the planting unit lift switch 47 is in the "up" position. The controller 100 also stops the work motor 117 when turning in the field, for example, when turning to move to the next process. For example, the controller 100 stops the work motor 117 when the turning assist function is enabled and automatic turning is to be performed.

[0076] Next, the drive process of the work motor 117 according to this embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart illustrating the drive process of the work motor 117 according to this embodiment.

[0077] The controller 100 determines whether or not to perform work by the seedling planting unit 4 (S100). If the controller 100 determines to perform work by the seedling planting unit 4 (S100: Yes), it drives the work motor 117 (S101). The controller 100 supplies power from the battery 116 to the work motor 117 to drive the work motor 117.

[0078] When the seedling planting unit 4 is not to perform work (S100: No), the controller 100 does not drive the work motor 117 (S102). The controller 100 does not supply power from the battery 116 to the work motor 117, and does not drive the work motor 117.

[0079] The seedling transplanter 1 includes an engine 30, a transmission case 13, a drive shaft 42, a rear wheel gear case 11a, a motor generator 115, a battery 116, a work motor 117, and a seedling planting unit 4. The transmission case 13, the drive shaft 42, and the rear wheel gear case 11a transmit power generated by the engine 30 to the rear wheels 11. The motor generator 115 generates electricity using the power generated by the engine 30. The battery 116 is charged with the power generated by the motor generator 115. The work motor 117 is driven by power supplied from the battery 116. The seedling planting unit 4 is driven by the power generated by the work motor 117.

[0080] As a result, the seedling transplanter 1 can reduce the output of the engine 30 by driving the seedling planting unit 4 with the work motor 117. This allows the seedling transplanter 1 to reduce fuel consumption by the engine 30 and reduce exhaust gas emissions. The seedling transplanter 1 can also reduce fluctuations in the rotation speed of the engine 30 in response to changes in the working state of the seedling planting unit 4, for example. This allows the seedling transplanter 1 to operate the engine 30 in a fuel-efficient range to charge the battery 116 and drive the work motor 117 with power supplied from the battery 116. This allows the seedling transplanter 1 to reduce fuel consumption by the engine 30 and reduce exhaust gas emissions.

[0081] The motor generator 115 receives power from a rear wheel gear case 11 a that transmits power to the rear wheels 11 and generates electricity.

[0082] This allows the seedling transplanter 1 to place the motor generator 115, the battery 116, and the work motor 117 in a location close to the seedling planting section 4. Therefore, the seedling transplanter 1 can shorten the power lines connecting the motor generator 115, the battery 116, and the work motor 117.

[0083] The working motor 117 is not driven when the seedling planting unit 4 is not driven. In addition, when the working motor 117 is not driven, the motor generator 115 functions as a motor that drives the rear wheels 11.

[0084] As a result, the seedling transplanter 1 can reduce fuel consumption of the engine 30 and reduce exhaust gas emissions.

[0085] The work motor 117 is not driven when turning during work in the field.

[0086] This allows the seedling transplanter 1 to reduce the power consumed by the working motor 117, for example, when turning to move to the next process.

[0087] When the seedling transplanter 1 is turning, the motor generator 115 on the inside of the turning direction may function as a generator to generate electricity, and the motor generator 115 on the outside of the turning direction may function as a motor to drive the rear wheel 11 on the outside of the turning direction with the power generated by the motor generator 115.

[0088] As a result, the seedling transplanter 1 can suppress the fuel consumption of the engine 30 while suppressing the decrease in the remaining charge of the battery 116.

[0089] When the remaining charge of the battery 116 falls below a first predetermined remaining charge, the seedling transplanter 1 generates electricity using the motor generator 115 to charge the battery 116. The first predetermined remaining charge is a preset remaining charge. For example, when the motor generator 115 is functioning as a motor to drive the rear wheels 11, if the remaining charge of the battery 116 falls below the first predetermined remaining charge, the controller 100 causes the motor generator 115 to function as a generator to generate electricity and charge the battery 116. In this case, the rear wheels 11 are driven by power generated by the engine 30.

[0090] When the remaining charge of the battery 116 is equal to or greater than a second predetermined remaining charge, the seedling transplanter 1 may cause the motor generator 115 to function as a motor and drive the rear wheels 11 with power generated by the motor generator 115. For example, when the remaining charge of the battery 116 is equal to or greater than the second predetermined remaining charge, the seedling transplanter 1 supplies power from the battery 116 to the working motor 117 and the motor generator 115.

[0091] This allows the seedling transplanter 1 to have the motor generator 115 function as a motor or a generator depending on the remaining charge of the battery 116, and allows the rear wheels 11 to be driven by the power generated by the motor generator 115 while preventing the remaining charge of the battery 116 from decreasing.

[0092] When the amount of slip of the rear wheels 11 is equal to or greater than a predetermined amount, the seedling transplanter 1 may cause the motor generator 115 to function as a motor, and drive the rear wheels 11 with the power generated by the motor generator 115. The power generated by the motor generator 115 is controlled to suppress slip of the rear wheels 11. The predetermined amount of slip is set in advance. The amount of slip of the rear wheels 11 is calculated, for example, according to the difference between the speed of the traveling vehicle body 2 based on the number of rotations detected by the rotation speed sensor 90 and the speed of the traveling vehicle body 2 based on the positioning information measured by the position acquisition device 150.

[0093] This allows the seedling transplanter 1 to prevent slippage in the field.

[0094] As shown in Fig. 6, the seedling transplanter 1 may be provided with a generator 121 to which power generated by the engine 30 is input via a transmission mechanism 120 without going through the transmission case 13. Fig. 6 is a diagram illustrating power transmission in the seedling transplanter 1 according to a modified example.

[0095] The seedling transplanter 1 may be provided with a speed change device such as a gear mechanism between the rear wheel transmission shaft 114b and the motor generator 115. The speed change device increases the rotation speed of the rear wheel transmission shaft 114b and transmits it to the motor generator 115.

[0096] The work vehicle 1 may have the following configuration.

[0097] The work vehicle 1 may be provided with a heater that heats the battery 116. When the work vehicle 1 is cold and the temperature of the battery 116 is lower than a predetermined temperature, the work vehicle 1 supplies regenerative power to the heater, which heats the battery 116. In this way, the work vehicle 1 can warm the battery 116 and increase the efficiency of the battery 116.

[0098] The work vehicle 1 may supply the regenerative power to a seat heater. This allows the work vehicle 1 to warm the seat. For example, the work vehicle 1 can warm the worker using the seat heater until the warm-up of the engine 30 is complete.

[0099] The work vehicle 1 may be provided with a heater that warms the coolant for the engine 30. When the work vehicle 1 is cold and the engine 30 (coolant for the engine 30) is low, regenerative electric power may be supplied to the heater that warms the coolant for the engine 30. This allows the work vehicle 1 to warm up the engine 30 quickly.

[0100] The work vehicle 1 may be equipped with a motor (or a motor generator) that drives the hydraulic pump. This allows the work vehicle 1 to drive the hydraulic pump without using a belt mechanism for driving the hydraulic pump. Therefore, the work vehicle 1 can drive the hydraulic pump without being affected by belt deterioration, for example.

[0101] The work vehicle 1 may be equipped with a motor (or a motor generator) that drives the cooling fan of the engine 30. This allows the work vehicle 1 to rotate the cooling fan using the motor to cool the engine 30. The work vehicle 1 can reduce the load on the engine 30.

[0102] For example, a motor generator that drives a cooling fan of engine 30 drives the cooling fan via a planetary gear mechanism. A sun gear of the planetary gear mechanism is connected to engine 30. A planetary gear of the planetary gear mechanism is connected to the cooling fan. An internal gear of the planetary gear mechanism is connected to the motor generator. When the temperature of engine 30 is high, the cooling fan is driven by the motor generator. When the temperature of engine 30 is not high, power is transmitted from engine 30 and motor generator 115 generates electricity.

[0103] The work vehicle 1 may be provided with a motor generator connected via an electromagnetic clutch to a crank pulley of the engine 30. The motor generator may be fixed to the gear case.

[0104] When the work vehicle 1 is a seedling transplanter, and the hand accelerator is positioned at a predetermined position for increasing the rotation speed of the engine 30 and the foot accelerator is depressed, the seedling transplanter 1 causes the motor generator 115 to function as a motor, and transmits the power generated by the motor generator 115 to the rear wheels 11. The power generated by the motor generator 115 may be controlled by the amount and speed of depression of the foot accelerator.

[0105] This allows the seedling transplanter 1 to adjust the power generated by the motor generator 115, that is, the power of the rear wheels 11, by a simple method of interlocking with the accelerator pedal depression by the operator.

[0106] When a switch provided near the handle 35 is operated (pushed down), the seedling transplanter 1 may cause the motor generator 115 to function as a motor and transmit the power generated by the motor generator 115 to the rear wheel 11.

[0107] The work vehicle 1 may be a tractor. For example, the work machine is a tiller. When the hand accelerator is positioned at a predetermined position to increase the engine speed and the foot accelerator is depressed, the tractor causes the motor generator to function as a motor, and the power generated by the motor generator is transmitted to the rear wheels. Note that the power generated by the motor generator may be controlled by the amount and speed of depression of the foot accelerator.

[0108] When a switch provided near the steering device is operated (depressed), the tractor may cause the motor generator to function as a motor and transmit power generated by the motor generator to the rear wheels.

[0109] When a switch provided on the gearshift lever is operated (pushed down), the tractor may cause the motor generator to function as a motor and transmit power generated by the motor generator to the rear wheels.

[0110] The work vehicle 1 may be a combine harvester. For example, the work machine is a harvesting device. The combine harvester may cause the motor generator to function as a motor and transmit power generated by the motor generator to the traveling device when the engine speed is equal to or higher than a preset specified value and a switch provided near the steering device is operated (depressed).

[0111] When a switch provided at the foot of the driver's seat is depressed, the combine harvester may cause the motor generator to function as a motor and transmit power generated by the motor generator to the traveling device. Note that the power generated by the motor generator may be controlled by the amount and speed at which the switch is depressed.

[0112] The work vehicle 1 may be a walk-behind work vehicle. For example, the work machine is a tiller. In the work vehicle 1, when the hand accelerator is in a predetermined position that increases the engine speed, the power generated by the motor generator may be controlled in accordance with the strength with which the steering device is gripped.

[0113] As shown in FIG. 7, the work vehicle 1 may be provided with a power generation mechanism 130, and the battery 116 may be charged with electric power generated by the power generation mechanism 130. FIG. 7 is a diagram illustrating the power generation mechanism 130 of a work vehicle 1 according to a modified example. The power generation mechanism 130 includes a roller 131, a shaft 132, a magnet 133, and a coil 134. The roller 131 is provided so as to contact a belt 140 of the engine 30. The shaft 132 is connected to the roller 131, and the magnet 133 is provided at the end of the shaft 132. The coil 134 is provided so as to surround the outer periphery of the magnet 133. A charging circuit that charges the battery 116 is connected to the coil 134. In the power generation mechanism 130, vibrations of the belt 140 are transmitted to the roller 131, the shaft 132, and the magnet 133, causing the magnet 133 to vibrate in the axial direction of the shaft 132. When the magnet 133 vibrates in the coil 134 in the axial direction of the shaft 132, the power generating mechanism 130 generates electricity and the battery 116 is charged.

[0114] This allows the work vehicle 1 to charge the battery 116 by the power generation mechanism 130 while the engine 30 is running.

[0115] The power generation mechanism 130 may be provided with a spring instead of the shaft 132 or as part of the shaft 132. The spring is provided so that the vibration frequency of the belt 140 matches the eigenvalue of the spring. This allows the power generation mechanism 130 to amplify the vibration of the belt 140 and generate electricity.

[0116] The power generating mechanism 130 may connect the roller 131 and the magnet 133 by a link mechanism instead of the shaft 132. The link mechanism is provided so as to amplify the vibration of the belt 140.

[0117] The work vehicle 1 may adjust the amount of power generated by the motor generator 115 according to the load on the work equipment.

[0118] For example, if the work vehicle 1 is a lawnmower, the load on the engine is calculated according to the height of the lawnmower's cutter and the position of the transmission gear. The engine's surplus power is then allocated to power generation by the motor generator. For example, if the cutter height is high, the engine load for driving the cutter is small, so the engine's surplus power is large. As a result, the amount of power generated by the motor generator is large. On the other hand, if the cutter height is low, the engine load for driving the cutter is large, so the engine's surplus power is small. As a result, the amount of power generated by the motor generator is small.

[0119] Similarly, if the work vehicle 1 is a tractor, the load on the engine is calculated according to the height of the tiller and the position of the transmission gear, and the engine's surplus power is allocated to power generation by the motor generator.

[0120] Furthermore, when the work vehicle 1 is a tractor, the power generation load of the motor generator is adjusted according to the state of the shift lever. For example, when the shift lever is in the reverse position, the tractor maximizes the power generation load of the motor generator, increasing the amount of power generated by the motor generator and charging the battery.

[0121] If the work vehicle 1 is a combine harvester, the power generation load of the motor generator is adjusted according to the operating state of the auger and the traveling state of the vehicle. For example, if the operating state of the auger is transporting (discharging) grains and the vehicle is stopped, the combine harvester maximizes the power generation load of the motor generator, increases the amount of power generated by the motor generator, and charges the battery.

[0122] The work vehicle 1 may adjust the power generation in the motor generator according to the amount of fuel remaining in the fuel tank. For example, when there is a lot of fuel remaining in the fuel tank, the work vehicle 1 increases the number of opportunities for the motor generator to function as a motor, or increases the amount of power generated by the motor generator. When there is little fuel remaining in the fuel tank, the work vehicle 1 reduces the number of opportunities for the motor generator to function as a motor, or decreases the amount of power generated by the motor generator.

[0123] As a result, the work vehicle 1 prioritizes charging the battery when there is a large amount of fuel remaining in the fuel tank, and is able to prevent running out of fuel when there is little fuel remaining in the fuel tank.

[0124] The work vehicle 1 may have a normal mode and a high-output mode as drive assist modes in which the motor generator functions as a motor to drive the rear wheels. In the normal mode, drive assist is performed within the range of engine output. In the high-output mode, drive assist is performed beyond the range of engine output. The drive assist mode is changed by the operator operating a switch, etc.

[0125] The drive assist may be an assist for engine torque. The work vehicle 1 has a normal mode and a high torque mode as drive assist modes. In the normal mode, drive assist is performed within the range of engine torque. In the high torque mode, drive assist is performed beyond the range of engine torque.

[0126] The work vehicle 1 may use the engine exclusively for power generation. That is, the work vehicle 1 generates power using a generator driven by the engine to charge the battery. The work vehicle 1 then transmits the power generated by the motor to, for example, the wheels.

[0127] The work vehicle 1 may be provided with a motor where the hydraulic pump is attached. When the engine is started, the motor starts the engine by rotating the shaft of the hydraulic pump. A belt may be attached to the motor shaft, and the motor may rotate the pulley of the water pump via the belt. The rotation speed of the water pump is controlled by the motor. The motor may also be connected to a fan via a planetary gear mechanism and a belt. The rotation speed or rotation direction of the fan is changed by the planetary gear mechanism.

[0128] The work vehicle 1 may be provided with a generator directly connected to the crank pulley. The work vehicle 1 may be provided with a motor in the cam gear section.

[0129] The work vehicle 1 may have an output shaft that can be rotated by both the engine and the motor, and when the workload is heavy and the engine speed drops, the output shaft may be rotated by the motor in addition to the engine to automatically provide output assistance. For example, the work vehicle 1 has an auto mode in which the motor assist force is automatically set to an optimum value, and a manual mode in which the motor assist force can be manually adjusted using a dial or the like. In the auto mode, the sensitivity (frequency) at which the motor assist is performed may be automatically set to an optimum value.

[0130] When the work load of the work vehicle 1 is light and the temperature of the exhaust gas is not high enough to activate the catalyst in the aftertreatment device, the temperature of the exhaust gas may be increased by an electric heater provided in the aftertreatment device or in the exhaust path. When the temperature of the exhaust gas is increased by an electric heater, the power consumed by the electric heater is generated by a generator.

[0131] For example, an electric heater may be provided at the inlet end face of the oxidation catalyst of the aftertreatment device. If a deterioration in the function of the oxidation catalyst is detected, the electric heater may be activated. Also, an electric heater may be provided at the inlet end face of the DPF (Diesel Particulate Filter) of the aftertreatment device. If a specified amount or more of soot is accumulated in the DPF, the electric heater may be activated. In this case, the work vehicle 1 does not need to be provided with an intake throttle valve or an exhaust valve.

[0132] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0133] 1. Seedling transplanter (work vehicle) 2 Running vehicle 4 Seedling planting section (work machine) 10 Front wheels 11 Rear wheel 11a Rear wheel gear case (transmission mechanism) 13 Transmission case (transmission mechanism) 42 Drive shaft (transmission mechanism) 100 Controllers 115 Motor generator (generator) 116 Battery 117 Work motor

Claims

1. The engine and a transmission mechanism that transmits power generated by the engine to wheels; a generator that generates electricity using power generated by the engine; a battery that is charged by the power generated by the generator; a working motor that is driven by power supplied from the battery; a work machine driven by power generated by the work motor; Equipped with the generator is a motor generator, the work motor is not driven when the work machine is not driven, the generator functions as a motor that drives rear wheels when the work machine is not driven, The generator is a first motor generator capable of driving a left rear wheel; a second motor generator capable of driving the right rear wheel; Including, Of the first motor generator and the second motor generator, the motor generator on the inside of a turn generates electricity during turning, and the motor generator on the outside of a turn drives the rear wheel on the outside of the turn.

2. The work vehicle according to claim 1 , wherein the generator generates electricity by receiving power from the transmission mechanism that transmits power to rear wheels.

3. The work vehicle according to claim 1 , wherein the work motor is not driven when the work vehicle is turning while working in a field.

4. 2. The work vehicle according to claim 1, wherein the generator functions as a motor that drives the rear wheels when a slip amount of the rear wheels is equal to or greater than a predetermined slip amount.

5. 2. The work vehicle according to claim 1, wherein, when the remaining charge of the battery falls below a first predetermined remaining charge while the generator is functioning as a motor that drives the rear wheels, the generator generates electricity to charge the battery, and the rear wheels are driven by power generated by the engine.

6. The work vehicle according to claim 5, wherein when the remaining charge of the battery reaches or exceeds a second predetermined remaining charge that is greater than the first predetermined remaining charge, the generator functions as a motor that drives the rear wheels.

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