Agricultural machine

Abstract

To provide an agricultural machine capable of maintaining the ground in an appropriate condition when a tiller is lifted and transitions to a non-working state.SOLUTION: An agricultural machine includes: a vehicle body; a traveling device for supporting the vehicle body in a travelable manner; a tiller having rotatingly-driving tiller tines; a lifting / lowering device for connecting the tiller to the vehicle body in a liftable / lowerable manner; and a control device for performing reduction processing to gradually reduce output of power for rotatingly driving the tiller tines as the tiller transitions from a working state where the tiller is working, to a non-working state where the lifting / lowering device lifts the tiller and the tiller is not working.SELECTED DRAWING: Figure 6A

Description

[Technical Field]

[0001] The present invention relates to an agricultural machine equipped with a tillage implement. [Background technology]

[0002] The work vehicle disclosed in Patent Document 1 is equipped with a lifting mechanism that drives the rotary tillage device mounted on the rear of the running body to raise and lower it, and drives the lifting mechanism to raise the rotary tillage device from the lowered position to the intermediate position at a slower speed than the speed at which it is raised from the intermediate position to the raised position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-278840 Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration of Patent Document 1 can prevent the occurrence of tillage marks when the rotary tillage implement (tiller) is raised. However, because the operation of the rotary tillage implement is stopped after the rotary tillage implement is raised to the raised position, no attention is paid to the rotation of the rotary tines (tiller tines) when the rotary tillage implement is raised, leaving room for improvement.

[0005] The present invention has been made to solve the problems of the prior art, and aims to provide an agricultural machine that can maintain the ground in an appropriate condition when the tilling implement is raised and the machine is put into a non-working state. [Means for solving the problem]

[0006] An agricultural machine according to one embodiment of the present invention comprises a vehicle body, a traveling device that supports the vehicle body so that it can run, a tillage device having tillage tines that are driven to rotate, a lifting device that connects the tillage device to the vehicle body so that it can be raised and lowered, and a control device that performs a reduction process to gradually reduce the output of power that drives the tillage tines to rotate as the tillage device transitions from a working state in which it is performing work to a non-working state in which it is not performing work, in which the lifting device raises the tillage device. [Effects of the Invention]

[0007] According to the above configuration, the ground can be kept in an appropriate state when the tilling implement is raised and transitioned to a non-working state. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing an embodiment of an agricultural machine. [Figure 2] 1 is a block diagram showing an outline of the configuration of an embodiment of an agricultural machine; [Figure 3] FIG. [Figure 4A] 10 is an example showing the operation of the lifting device. [Figure 4B] 10 is another example showing the operation of the lifting device. [Figure 4C] 10 is another example showing the operation of the lifting device. [Figure 5A] FIG. 2 is a diagram illustrating the working state of the tillage implement. [Figure 5B] FIG. 10 is a diagram illustrating a non-working state of the tillage implement. [Figure 5C] FIG. 10 is a diagram showing the locus of the lowest point when transitioning from a working state to a non-working state. [Figure 5D] FIG. 10 is a diagram illustrating a problem of the present embodiment. [Figure 6A] FIG. 10 is a diagram showing the relationship between the height from the ground to the tillage implement and the rotation speed of the tillage tines. [Figure 6B] FIG. 10 is a diagram showing another example of the relationship between the height from the ground to the tillage implement and the rotation speed of the tillage tines. [Figure 6C]FIG. 10 is a diagram illustrating an example of a conversion map. [Figure 7] FIG. 2 is a basic flowchart according to the present embodiment. [Figure 8] FIG. 10 is a flowchart illustrating an example of a determination condition for a reduction process according to the present embodiment. [Figure 9] FIG. 2 is a diagram illustrating a farm field map and a planned driving route. [Figure 10] FIG. 10 is a flowchart showing an example of a determination condition for a reduction process according to a first modified example. [Figure 11] FIG. 11 is a flowchart showing an example of a determination condition for a reduction process according to a second modified example. [Figure 12] FIG. 11 is a flowchart showing an example of a determination condition for a reduction process according to a third modified example. [Figure 13] FIG. 11 is a flowchart showing another example of the determination conditions for the reduction process according to the third modified example. [Figure 14] FIG. 13 is a flowchart showing an example of a determination condition for a reduction process according to a fourth modified example. [Figure 15] FIG. 13 is a flowchart showing another example of the determination conditions for the reduction process according to the fourth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] 1 is a side view showing one embodiment of an agricultural machine 100. In this embodiment, the agricultural machine 100 will be described as an example of a work vehicle (tractor) 1 to which a tilling implement 2 is attached.

[0011] As shown in Fig. 1, the agricultural machine 100 has a vehicle body 3. The vehicle body 3 is provided with a driver's seat 6 in which an operator sits. In the following description, the direction that an operator seated in the driver's seat 6 of the tractor 1 (agricultural machine 100) faces (the direction of arrow A1 in Fig. 1) will be referred to as the forward direction, the opposite direction (the direction of arrow A2 in Fig. 1) will be referred to as the rearward direction, the left side of the operator (the front side in Fig. 1) will be referred to as the left side, and the right side of the operator (the back side in Fig. 1) will be referred to as the right side.

[0012] As shown in FIG. 1 , the agricultural machine 100 is equipped with a traveling device 4, a transmission 5, and a lifting device 8. The agricultural machine 100 is equipped with a drive source for driving the tilling device 2, and in this embodiment, the drive source for driving the tilling device 2 is an electric motor M1. The agricultural machine 100 also has an electric motor M2 as a power source for driving the traveling device 4. In other words, the agricultural machine 100 of this embodiment has a power source (drive source) for driving the tilling device 2 and a power source for driving the traveling device 4 that are separate. The electric motors M1 and M2 are driven by electricity supplied from an electricity storage device 30 provided on the vehicle body 3. The electricity storage device 30, the electric motors M1 and M2, the traveling device 4, and the transmission 5 are provided on the vehicle body 3. The lifting device 8 is provided on the vehicle body 3, and is connected to the tilling device 2.

[0013] FIG. 2 is a block diagram showing an outline of the configuration of the agricultural machine 100. As shown in FIGS. 1 and 2, the agricultural machine 100 (tractor 1) is equipped with a control device 40. The control device 40 is a controller for the agricultural machine 100 and performs various controls related to the agricultural machine 100. As shown in FIG. 2, the control device 40 has a processor 40a and a storage device 40b. The processor 40a is, for example, a CPU (Central Processing Unit). The storage device 40b is composed of volatile or non-volatile memory, etc. The storage device 40b includes, for example, an SSD (Solid State Drive) or an HDD (Hard Disk Drive). The storage device 40b of the control device 40 stores programs and various data used by the control device 40 to control the operation of each part of the agricultural machine 100 in a readable and writable manner. The processor 40a reads and executes the programs from the storage device 40b, thereby realizing the functions of the control device 40.

[0014] In addition, some or all of the configuration of the control device 40 may be realized by hardware (including processing circuits) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of a program (software) and hardware.

[0015] The control device 40 is communicably connected to a plurality of devices mounted on the agricultural machine 100 via a network N such as CAN, ISOBUS, LIN, or FlexRay. The control device 40 controls the operation of each part of the agricultural machine 100 as shown in FIGS.

[0016] The power storage device 30 includes a plurality of battery modules, such as lead batteries or lithium ion batteries, each including a plurality of battery cells (lithium ion batteries) electrically connected (in series), and a battery case that houses the plurality of battery modules. That is, the power storage device 30 is a battery pack in which a plurality of battery modules are housed in a battery case and the plurality of battery modules are electrically connected (in series, for example).

[0017] The electric motors M1 and M2 are driven by electric power supplied from the power storage device 30. The electric motors M1 and M2 are, for example, three-phase AC synchronous motors with embedded permanent magnets.

[0018] As shown in FIG. 2 , the agricultural machine 100 includes an inverter 31, a junction box 32, a DC / DC converter 33, and a charger 34. The inverter 31 is electrically connected to the electric motor M1 and the junction box 32. The inverter 31 converts DC power supplied from the power storage device 30 via the junction box 32 into three-phase AC power and supplies the AC power to the electric motors M1 and M2. That is, the electric motors M1 and M2 are connected to the power storage device 30 via the inverter 31. The inverter 31 can arbitrarily change the current and voltage of the power supplied to the electric motors M1 and M2. The control device 40 controls the operation of the inverter 31 to drive or stop the electric motors M1 and M2. The control device 40 can also control the operation of the inverter 31 to change the power output and / or rotation speed generated by the electric motors M1 and M2.

[0019] The DC / DC converter 33 is connected to the power storage device 30 and converts the voltage of the DC power supplied from the power storage device 30 into a different voltage. In this embodiment, the DC / DC converter 33 is a step-down converter that converts an input voltage into a lower voltage. The DC / DC converter 33 supplies power to, for example, a low-voltage battery 35 that supplies power to electronic devices provided in the tractor 1.

[0020] The charger 34 is electrically connected to the junction box 32. The charger 34 has a connector that can be fitted with a charging cable, a rectifier that converts three-phase AC power into DC power, and an electronic circuit that adjusts the current and voltage of the DC power supplied to the junction box 32. When the charging cable is fitted into the connector, the charger 34 converts the three-phase AC power input from an external power source via the charging cable into DC power and supplies the DC power to the junction box 32. The power storage device 30 can be charged by power supplied from the external power source via the charger 34.

[0021] As shown in Fig. 1, the traveling device 4 supports the vehicle body 3 so that it can travel. In this embodiment, the traveling device 4 has a pair of left and right front wheels 4F and a pair of left and right rear wheels 4R that are driven to rotate, and is driven by power generated by an electric motor M2. The front wheels 4F and rear wheels 4R may be of a tire type or a crawler type.

[0022] The transmission 5 is connected to the drive shaft of the electric motor M2. Therefore, the power output by the electric motor M2 is transmitted to the transmission 5, and the traveling device 4 is driven by the power whose speed has been changed by the transmission 5. Note that the front wheels 4F and / or the rear wheels 4R may be driven by the power generated by a single electric motor M2, or the front wheels 4F and the rear wheels 4R may be driven by separate electric motors M2. Furthermore, the pair of front wheels 4F and the pair of rear wheels 4R may each be driven by a separate electric motor M2.

[0023] As shown in FIG. 2, the tractor 1 is equipped with a steering device 11. The steering device 11 has a handle (steering wheel) 11a, a rotating shaft (steering shaft) 11b that rotates in conjunction with the rotation of the handle 11a, and an assist mechanism (power steering mechanism) 11c that assists in steering the handle 11a. The assist mechanism 11c includes a hydraulic pump 21, a control valve 22 to which hydraulic oil discharged from the hydraulic pump 21 is supplied, and a steering cylinder 23 that is operated by the control valve 22. The control valve 22 is an electromagnetic valve that operates based on a control signal input from the control device 40. The control valve 22 is, for example, a three-position switching valve that can be switched by moving a spool or the like. The control valve 22 can also be switched by steering the steering shaft 11b. The front wheels 4F are supported by a front axle 21F. The steering cylinder 2 3 is connected to an arm (knuckle arm) 24 that changes the direction of the front wheel 4F.

[0024] Therefore, when the handle 11a is operated, the switching position and opening degree of the control valve 22 are switched in response to the handle 11a, and the steering cylinder 23 expands or contracts to the left or right in response to the switching position and opening degree of the control valve 22, thereby changing the steering direction (steering angle) of the front wheels 4F. In this way, the traveling device 4 can change the degree of straightness of the vehicle body 3. Note that the above-described steering device 11 is an example, and is not limited to the above-described configuration. Furthermore, it is sufficient for the traveling device 4 to change the degree of straightness of the vehicle body 3 by at least changing the steering angle, and for example, the steering angle may be changed by generating a rotational difference between the left and right front wheels 4F and rear wheels 4R.

[0025] As shown in Fig. 2, the tractor 1 (agricultural machine 100) is equipped with a steering angle detection device 71. The steering angle detection device 71 detects the steering angle of the traveling device 4 or the steering device 11. For example, the steering angle detection device 71 is configured by a potentiometer (angle sensor) provided in the steering device 11 (handle 11a).

[0026] The steering angle detection device 71 only needs to be able to detect the steering angle of the vehicle body 3, and may include a calculator to detect (calculate) the steering angle of the traveling device 4 based on a control signal input to the control valve 22. The steering angle detection device 71 outputs the detection result (steering angle) to the control device 40 periodically or at a predetermined timing. In the following explanation, the steering angle is set to zero when the tractor 1 is traveling straight (when traveling straight), and will be explained as the absolute value of the deviation from the steering angle when traveling straight unless otherwise specified.

[0027] The tillage implement 2 is an implement that performs work (plowing) in a field. In this embodiment, the tillage implement 2 is detachably attached to a lifting device 8 provided on the vehicle body 3. The tillage implement 2 has rotatably driven tillage tines 2A. The tillage tines 2A are rotated by power generated by a drive source (electric motor M1). Therefore, the tillage implement 2 is driven by the power generated by the electric motor M1 to perform work (plowing) in the field. Specifically, the tillage implement 2 receives power output from the electric motor M1 via a PTO shaft 16 that is provided so as to protrude rearward from the rear of the vehicle body 3.

[0028] The tillage implement 2 has the tines 2A described above, as well as a tine shaft 2B and a tillage cover 2C. The tine shaft 2B rotates in the direction of arrow Y1 in FIG. 1 by power transmitted by the PTO shaft 16. The tillage tines 2A are attached to the tine shaft 2B and rotate about the axis of the tine shaft 2B, penetrating the soil (ground surface G) of the field, tilling the soil, and throwing the tilled soil rearward. The tillage cover 2C is a cover that covers the tines 2A. The tillage cover 2C covers the upper and rear sides of the tines 2A and the rear sides of the lower ends of both sides in the width direction of the vehicle body, and a soil leveling cover is detachably attached to the lower end. The tillage cover 2C is pivotally supported about a pivot axis extending in the width direction of the vehicle body and can swing vertically. The tillage cover 2C is urged downward by a bomb lowering device 2D provided on the tillage implement 2.

[0029] As shown in FIG. 2, the tillage implement 2 may include a work control device 2a. The work control device 2a is a controller for the tillage implement 2 and performs various controls of the tillage implement 2. Like the control device 40, the work control device 2a has a configuration that includes a processor (CPU) and a storage device (memory), and detailed description of these will be omitted. In this embodiment, the tractor 1 has a connection unit 80, and the work control device 2a of the tillage implement 2 is connected to the network N via the connection unit 80. Note that in this embodiment, the control device 40 is connected to the work control device 2a via the connection unit 80 via a wired connection. However, the control device 40 may also be connected to the work control device 2a wirelessly via the connection unit 80, and the communication method is not limited.

[0030] The lifting device 8 connects the tillage implement 2 to the vehicle body 3 so that it can be raised and lowered. The lifting device 8 is provided at the rear of the vehicle body 3 and is configured with a three-point linkage mechanism or the like. Therefore, the vehicle body 3 can tow the tillage implement 2 by connecting the tillage implement 2 to the lifting device 8. In addition to the tillage implement 2, work implements such as a spraying device or a mowing device can be detachably connected to the lifting device 8.

[0031] 3 is a perspective view showing the lifting device 8. To explain the lifting device 8 in detail, as shown in FIG. 3, the lifting device 8 includes a lift arm 8a, a lower link 8b, a top link 8c, The lifting device 8 has a lift rod 8d and a lift cylinder 8e. The lifting device 8 can be switched between a working state C1 in which the tilling implement 2 is lowered so that the tilling implement 2 performs work, and a non-working state C2 in which the tilling implement 2 is raised so that the tilling implement 2 does not perform work. The front end of the lift arm 8a is supported on the upper rear part of the vehicle body 3 so that it can swing upward or downward. The lift arm 8a swings (lifts and lowers) when driven by the lift cylinder 8e.

[0032] The lift cylinder 8e is composed of a hydraulic cylinder. The lift cylinder 8e is connected to a hydraulic pump 21 (Fig. 2) via a control valve 19 (Fig. 2). The control valve 19 is an electromagnetic valve that operates in response to an applied current (control signal) and extends or retracts the lift cylinder 8e. The control valve 19 operates in response to a control signal (current value) input from the control device 40 and controls the operation of the lift cylinder 8e.

[0033] The control valve 19 is operated by a control signal to switch between supplying hydraulic oil to the lift cylinder 8e and discharging hydraulic oil from the lift cylinder 8e. Specifically, when hydraulic oil is supplied from the hydraulic pump 21 to the lift cylinder 8e via the control valve 19, the lift cylinder 8e extends. On the other hand, when hydraulic oil is discharged from the lift cylinder 8e via the control valve 19 due to the weight of the tilling implement 2 (work implement) connected to the lifting device 8, the lift cylinder 8e contracts.

[0034] As shown in Figure 3, the front end of lower link 8b is supported on the lower rear part of the vehicle body 3 so as to be able to swing upward or downward. The front end of top link 8c is supported on the rear part of the vehicle body 3 above lower link 8b so as to be able to swing upward or downward. Lift rod 8d connects lift arm 8a and lower link 8b. The rear part of lower link 8b and the rear part of top link 8c are connected to tillage implement 2.

[0035] 4A to 4C show the operation of the lifting device 8. As shown in FIGS. 4A to 4C, when the lift cylinder 8e extends and retracts, the lift arm 8a rises and falls, and the lower link 8b, which is connected to the lift arm 8a via the lift rod 8d, rises and falls. This allows the lifting device 8 to switch between a working state C1 in which the tilling implement 2 is working, and a non-working state C2 in which the tilling implement 2 is not working. At this time, the tilling implement 2 swings (lifts and falls) upward or downward, with the front part of the lower link 8b as a fulcrum.

[0036] FIG. 4A shows a state in which the lifting device 8 has lowered the tilling implement 2 to its maximum extent. FIG. 4C shows a state in which the lifting device 8 has raised the tilling implement 2 to its maximum extent. In other words, the lifting device 8 lowers the tilling implement 2, and the state transitions in the order of FIG. 4A, FIG. 4B, and FIG. 4C. Also, the lifting device 8 raises the tilling implement 2, and the state transitions in the order of FIG. 4C, FIG. 4B, and FIG. 4A.

[0037] The control device 40 can change the power output that rotates and drives the tiller tines 2A of the tiller implement 2. As described above, the tiller implement 2 can perform work (tilling work) by using the power of the electric motor M1 as a drive source to rotate and drive the tiller tines 2A. Specifically, when the control device 40 inputs a control signal to the inverter 31, the inverter 31 changes the current and voltage of the power supplied to the electric motor M1 and changes the power output generated by the electric motor M1. Changing the power output generated by the electric motor M1 changes the power output and / or rotation speed transmitted from the electric motor M1 to the PTO shaft 16, thereby changing the rotation speed V of the tiller tines 2A. In other words, the control device 40 can arbitrarily change the rotation speed V of the tiller tines 2A by controlling the output of the electric motor M1 via the inverter 31.

[0038] The problems of this embodiment will be described below with reference to Figures 5A to 5D. In working state C1 where tilling work is being performed in a farm field, one end of the tiller tine 2A digs into the ground G and is driven to rotate, digging up the soil. As shown in Figure 5A, the lowest point P of the tiller tine 2A (the lowest point of the rotation trajectory of the tip of the tiller tine 2A) is located below the ground G, and the tiller tine 2A is driven to rotate, causing the tiller implement 2 to perform tilling work.

[0039] As shown in Figure 5B, in the non-working state C2 where no tilling work is being performed, the lowest point P of the tiller tine 2A is located above the ground surface G, one end of the tiller tine 2A does not touch the ground surface G, and the soil is not dug up.

[0040] FIG. 5C shows the trajectory of the lowest point P when transitioning from working state C1 to non-working state C2. In this figure, ground surface G is used as the reference (zero), and the lowest point P is shown as a positive value when it is above ground surface G and as a negative value when it is below ground surface G. As shown in FIG. 5C, as the working state C1 transitions to non-working state C2, the position of the lowest point P rises (section T1). If the same power as in working state C1 is transmitted to the tiller tines 2A during the transition from working state C1 to non-working state C2, in the section (section T2) where the lowest point P is below ground surface G, the soil dug up as the tiller tines 2A rise may be thrown behind the tiller tines 2A, leaving tilled marks on the ground surface G (FIG. 5D). Examples of tilled marks include furrows deeper than the ground surface G. In addition to furrows, examples of tilled marks include ridges higher than the ground surface G.

[0041] To solve this problem, the control device 40 performs a reduction process to gradually reduce the output of power that rotates the tiller tines 2A as the tiller transitions from a working state C1, in which the tiller 2 is working, to a non-working state C2, in which the lifting device 8 raises the tiller 2 and the tiller 2 is not working. This prevents tillage marks from being formed on the ground G.

[0042] As shown in Fig. 2, the control device 40 has a reduction processing unit 41. The reduction processing unit 41 is, for example, a program stored in the storage device 40b and executed by the processor 40a. The reduction processing unit 41 controls the power output and / or rotation speed transmitted from the electric motor M1, which serves as a drive source, to the tillage tines 2A, and gradually reduces the rotation speed V of the tillage tines 2A. The control device 40 (reduction processing unit 41) continuously reduces the rotation speed V of the tillage tines 2A, for example.

[0043] As shown in Fig. 2, the agricultural machine 100 is equipped with a height detection device 72 that detects height information h of the lifting device 8 and / or tilling implement 2 from the field. The height of the lifting device 8 from the field is the height of a predetermined reference position of the lifting device 8 (for example, the rear end of the lower link 8b) from the field, and the height of the tilling implement 2 from the field is the height of a predetermined reference position of the tilling implement 2 from the field (for example, the lowest point P). The height information h is information that indicates a fluctuation (tendency) in whether the height of at least the lifting device 8 and / or tilling implement 2 from the field is increasing or decreasing.

[0044] The height information h may be information that indicates the height of the lifting device 8 and / or tilling device 2 from the field itself. The control device 40 performs a reduction process based on the height information h detected by the height detection device 72. Specifically, when the control device 40 determines that the working state C1 is being transitioned to the non-working state C2, the control device 40 gradually reduces the rotation speed V of the tilling tines 2A based on the height information h as the height of the lifting device 8 and / or tilling device 2 from the field increases.

[0045] The height detection device 72 is a detection device such as a cylinder stroke sensor that detects the extension and retraction of the lift cylinder 8e or a potentiometer that detects the swing angle of the lift arm 8a. The control device 40 detects the extension and retraction state of the lift cylinder 8e based on the detection results of the detection device, and obtains height information h from the extension and retraction state of the lift cylinder 8e.

[0046] Furthermore, the height detection device 72 may have a configuration that includes a processor (CPU) and a storage device (memory) in addition to the cylinder stroke sensor or potentiometer, and the storage device may store a program for performing arithmetic processing. In such a case, the height detection device 72 detects, as height information h, information that indicates the height of the lifting device 8 and / or the tilling device 2 from the field.

[0047] The height detection device 72 detects height information h by executing a program that uses the value detected by the potentiometer or stroke sensor as an input parameter and converts (calculates) the height from the ground G to the lifting device 8 (tiller 2). Alternatively, the height information h may be detected by executing a program that uses the operation amount of the control device 50 (described later) as an input parameter and converts (calculates) the height from the ground G to the lifting device 8. Alternatively, the tillage depth X calculated by the tillage depth calculation unit 42 (described later) may be used as height information h.

[0048] Furthermore, the height detection device 72 may be a laser sensor that detects the height from the lifting device 8 to the ground G (field). In such a case, the height detection device 72 detects the height from the ground G to the tilling device 2. Furthermore, a plurality of height detection devices 72 may be provided, and both the height from the ground G to the lifting device 8 and the height from the ground G to the tilling device 2 may be detected.

[0049] The height detection device 72 outputs the detection result (height information h) to the control device 40 periodically or at a predetermined timing.

[0050] 6A is a diagram showing the relationship between the height from the ground G to the tillage implement 2 and the rotational speed V of the tillage tine 2A. As shown in FIG. 6A, when the working state C1 transitions to the non-working state C2 and the height from the ground G to the tillage implement 2 (height information h) increases, the control device 40 continuously reduces the rotational speed V of the tillage tine 2A until it reaches zero. The rotational speed V of the tillage tine 2A is monotonically proportional to the height from the ground G to the tillage implement 2 (height information h).

[0051] The relationship between the height from the ground G to the tiller implement 2 (height information h) and the rotational speed V of the tiller tine 2A may be a curve rather than a substantially linear line as shown in FIG. 6A . In such a case, the control device 40 may first reduce the rotational speed V of the tiller tine 2A relatively rapidly as the height from the ground G to the tiller implement 2 (height information h) increases, and then reduce the rotational speed V of the tiller tine 2A relatively gradually. In other words, the rotational speed V of the tiller tine 2A decreases exponentially with respect to the height from the ground G to the tiller implement 2 (height information h). Conversely, the control device 40 may first reduce the rotational speed V of the tiller tine 2A relatively gradually as the height from the ground G to the tiller implement 2 (height information h) increases, and then reduce the rotational speed V of the tiller tine 2A relatively rapidly. Furthermore, the relationship between the height (height information h) from the ground G to the tillage implement 2 and the rotational speed V of the tillage implement 2A does not have to be continuous, and the control device 40 may gradually reduce the rotational speed V of the tillage implement 2A as the height (height information h) from the ground G to the tillage implement 2 increases, as shown in Figure 6B, for example.

[0052] The storage device 40b pre-stores a conversion map T that associates an arithmetic expression with a calculation coefficient α of the rotation speed V of the tiller tine 2A corresponding to the height information h. The calculation expression for the rotation speed V is defined as V=αV1, where V1 is the rotation speed of the tiller tine 2A commanded by the operation signal of the control device 50 and V1 is multiplied by the calculation coefficient α. As shown in FIG. 6C, the conversion map T is stored as table-format data. The calculation coefficient α is defined as α=1 when the height information h is equal to or less than a predetermined value h1 (the value when the control device 40 determines that a lowering process should be performed). The calculation coefficient α decreases as the height information h increases. The calculation coefficient α is defined as α=0 when the height information h is equal to or greater than a predetermined value hx.

[0053] Alternatively, a software program in which the height information h is converted into a function as an input parameter may be stored in the storage device 40b, and the value of the rotation speed V may be acquired by the reduction processing unit 41 executing the software program.

[0054] When height information h detected by the height detection device 72 is input, the reduction processing unit 41 references the conversion map T to obtain the value of the corresponding calculation coefficient α and executes a calculation formula to obtain the value of the rotation speed V. The reduction processing unit 41 inputs a control signal to the inverter 31 to control the power supplied to the electric motor M1, thereby changing the power output or rotation speed generated by the electric motor M1 and changing (reducing) the rotation speed V of the tiller tines 2A. Note that the reduction processing unit 41 obtains the value of the rotation speed V based on the height information h and controls the electric motor M1, but the method of obtaining the value is not limited to the example described above. For example, the reduction processing unit 41 may reduce the rotation speed V of the tiller tines 2A based on the elapsed time since the reduction processing was executed.

[0055] Before the reduction processing unit 41 executes the reduction processing, it is determined whether the tiller implement 2 will transition from the working state C1 to the non-working state C2. The control device 40 determines whether to execute the reduction processing based on the state of the agricultural machine 100.

[0056] Fig. 7 is a basic flowchart according to this embodiment. As shown in Fig. 7, the control device 40 acquires the state of the agricultural machine 100 (S1), and determines whether or not to perform the lowering process (S2). When the control device 40 determines that the lowering process should be performed (S2: Yes), the lowering processing unit 41 acquires height information h and performs the lowering process based on the acquired height information h (S3).

[0057] The control device 40 determines whether or not to perform reduction processing by the reduction processing unit 41 based on, for example, the steering angle as the state of the agricultural machine 100. Here, when the steering angle becomes relatively large and the vehicle body 3 turns, the agricultural machine 100 turns smoothly and reduces damage to the tiller implement 2. The agricultural machine 100 transitions from the normal working state C1 to the non-working state C2 based on the turning (steering angle) of the vehicle body 3. Therefore, it is possible to determine whether the agricultural machine 100 will transition from the working state C1 to the non-working state C2 based on the turning (steering angle) of the vehicle body 3. Therefore, when the steering angle is equal to or greater than a predetermined value, the control device 40 determines that the agricultural machine 100 is transitioning from the working state C1 to the non-working state C2, and performs reduction processing.

[0058] As shown in Fig. 8, the control device 40 acquires the steering angle of the vehicle body 3 from the steering angle detection device 71 (S1a). The control device 40 determines whether the steering angle is equal to or greater than a predetermined value (S2a). If the steering angle is equal to or greater than the predetermined value (S2a: Yes), the control device 40 determines that reduction processing should be performed, and proceeds to step S3. The control device 40 (reduction processing unit 41) performs reduction processing based on the acquired height information h (S3). If the steering angle is not equal to or greater than a predetermined value (S2a: No), the process returns to step S1a.

[0059] In the above example, the control device 40 performs the reduction process when the steering angle is equal to or greater than a predetermined value, but the conditions are not limited to the above. For example, the control device 40 may be configured to perform the reduction process when the steering angle has been increasing or decreasing continuously for a predetermined period of time. In other words, the control device 40 may be configured to perform the reduction process when the vehicle body 3 has a tendency to continuously turn in a predetermined direction.

[0060] <First Modification> Furthermore, in the above-described embodiment, the control device 40 determines whether or not to perform the reduction processing based on the steering angle as the state of the agricultural machine 100. However, the control device 40 may determine whether or not to perform the reduction processing based on the field map MP showing the field and the position of itself (the vehicle body 3) instead of or in addition to the steering angle.

[0061] In such a case, the agricultural machine 100 is equipped with a position detection device 60, as shown in FIG. 2. The position detection device 60 can detect its own position (positioning information including latitude and longitude) using a satellite positioning system (positioning satellite), such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki. That is, the position detection device 60 receives satellite signals (positions of the positioning satellites, transmission times, correction information, etc.) transmitted from the positioning satellites, and detects the position (e.g., latitude and longitude) of the tractor 1 (body 3), i.e., the body position, based on the satellite signals. The position detection device 60 includes a positioning device 61 and an inertial measurement unit (IMU) 62. The positioning device 61 is a device that has an antenna and receives satellite signals transmitted from the positioning satellites, and is attached to the body 3 separately from the inertial measurement unit 62. In this embodiment, as shown in FIG. 1, the positioning device 61 is attached to the top of a rope provided on the body 3. The installation position of the positioning device 61 is not limited to the above position, but may be in the center of the hood, or if the vehicle body 3 is provided with a protective mechanism such as a cabin, it may be above the protective mechanism, or it may be attached to the tillage device 2.

[0062] The inertial measurement unit 62 has an acceleration sensor that detects the acceleration of the vehicle body 3, a gyro sensor that detects the angular velocity of the vehicle body 3, and the like. The inertial measurement unit 62 is provided in the vehicle body 3, for example, below the driver's seat 6. The inertial measurement unit 62 can detect the roll angle, pitch angle, yaw angle, and the like of the vehicle body 3.

[0063] In this modification, the position detection device 60 detects the position of the vehicle body 3 based on satellite signals. However, the position detection device 60 is not limited to the above configuration as long as it can detect the position of the vehicle body 3. For example, the position detection device 60 may be a device that detects the position of the vehicle body 3 based on acceleration detected by the inertial measurement unit 62 and predetermined position information. The position detection device 60 may also be a laser sensor, i.e., a LiDAR (Light Detection and Ranging) sensor. A laser sensor (LIDAR) emits pulsed infrared light or the like millions of times per second and measures the time it takes for the light to bounce back, thereby estimating a 3D map of the area around the vehicle body 3 and the position of the vehicle body 3 on the 3D map.

[0064] The agricultural machine 100 is equipped with a storage device 40b that stores a field map MP that indicates the field. FIG. 9 is a diagram illustrating the field map MP and the planned travel line L. The field map MP is data that indicates the contour (outline) H1 of the field. The field map MP is defined, for example, by the travel trajectory obtained by the agricultural machine 100 traveling around the field and detecting a plurality of vehicle positions by the position detection device 60. The field map MP stores field identification information (for example, The field map MP is associated with a certain field (for example, "field A") and stored in the storage device 40b. The method for defining the field map MP is not limited to the method described above. For example, the field map MP may be defined using position information of the field's edge points measured by a terminal capable of acquiring positioning information. In this case, the field map MP is stored in the storage device 40b via wireless or wired communication or a storage medium. The data format of the field map MP may be data represented by position (latitude, longitude) or data represented by a coordinate system (X-axis, Y-axis). Furthermore, the data may be represented as a 3D map showing a 3D shape, or may be represented in other ways.

[0065] As shown in Fig. 9, the field map MP includes a turning area E1 in which the agricultural machine 100 (body 3) turns. The turning area E1 is, for example, an area (headland area) surrounded by a contour H2 that is offset inward from a contour H1 of the field map MP by a distance equal to a headland width W1. The headland width W1 is a value that is input (defined) by the operator through a predetermined operation, and is stored in advance in the storage device 40b. In addition to the turning area E1, the field map MP also includes a work area E2 that is an area other than the turning area E1 and in which work (plowing work) is performed.

[0066] The control device 40 determines whether to perform lowering processing based on the position of the vehicle body 3 on the field map MP. The vehicle body 3 turns when it is located in the turning area E1 defined in the field map MP. As described above, when the vehicle body 3 turns, the agricultural machine 100 raises the tilling implement 2 and transitions to the non-working state C2 in order to turn smoothly and prevent damage to the tilling implement 2. Therefore, when the vehicle body 3 approaches the turning area E1, it can be determined that the agricultural machine 100 will transition from the working state C1 in which tilling work is performed to the non-working state C2 in which the tilling implement 2 is raised and no work is performed. Therefore, when the vehicle body 3 is approaching the vicinity of the turning area E1 or located in the turning area E1, the control device 40 determines that the agricultural machine 100 is transitioning from the working state C1 to the non-working state C2, and performs lowering processing.

[0067] As shown in Fig. 10, the control device 40 acquires the vehicle body position of the vehicle body 3 from the position detection device 60 (S1b). The control device 40 refers to the field map MP stored in the storage device 40b and determines whether the vehicle body position of the vehicle body 3 is approaching the vicinity of the turning area E1 (S2b). If the vehicle body position of the vehicle body 3 is approaching the vicinity of the turning area E1 (S2b: Yes), the control device 40 determines that lowering processing should be performed and proceeds to step S3. If the vehicle body position of the vehicle body 3 is not approaching the vicinity of the turning area E1 (S2b: No), the control device 40 returns to step S1b.

[0068] In step S2b, the determination condition may be whether the body position of the body 3 is located in the turning area E1. Also, the determination condition may be at least one of the body position of the body 3 being close to the turning area E1 and being located in the turning area E1.

[0069] <Second Modification> In the first variant, the control device 40 determines whether or not to perform the lowering process based on the field map MP and the position of the vehicle body 3 as the state of the agricultural machine 100. However, the control device 40 may determine whether or not to perform the lowering process based on the planned travel line L and the position of itself (the vehicle body 3) instead of, or in addition to, the state of the agricultural machine 100 described above.

[0070] Unlike the first modification, the storage device 40b of the second modification stores a planned travel line L, which is defined in the field and is a route along which the vehicle body 3 will travel. The planned travel line L is stored in association with the field map MP. The planned travel line L includes a straight section L1 along which the vehicle body 3 travels straight and a turning section L2 along which the vehicle body 3 turns. The straight section L1 is created mainly in the work area E2, and the turning section L2 is created mainly in the turning area E1. For example, the planned travel line L is defined by a calculation program using graph theory with the field map MP, the work start point ST, and the work end point ED as input parameters. When the operator performs a predetermined operation, the control device 40 executes the calculation program to calculate the planned travel line L and stores the calculated planned travel line L in the storage device 40b. The method for defining the planned travel line L is not limited to the above configuration. For example, the operator may manually define the planned travel line L using a touch panel provided on the agricultural machine 100. The planned travel line L may also be calculated (defined) by a server or terminal external to the agricultural machine 100. In this case, the planned travel line L may be stored in the storage device 40 via wireless or wired communication or a storage medium. It is stored in b.

[0071] The control device 40 determines whether to perform lowering processing based on the position of the vehicle body 3 on the planned travel line L. The vehicle body 3 turns when it is located at the turning section L2 defined on the planned travel line L. As described above, when the vehicle body 3 turns, the agricultural machine 100 raises the tiller implement 2 and transitions to the non-working state C2 in order to turn smoothly and prevent damage to the tiller implement 2. For this reason, when the vehicle body 3 is located at the turning section L2, it can be determined that the agricultural machine 100 will transition from the working state C1 in which tilling work is performed to the non-working state C2 in which the tiller implement 2 is raised and no work is performed. Therefore, when the vehicle body 3 is located at the turning section L2, the control device 40 determines that the agricultural machine 100 is transitioning from the working state C1 to the non-working state C2, and performs lowering processing.

[0072] As shown in Fig. 11, the control device 40 acquires the body position of the body 3 from the position detection device 60 (S1c). The control device 40 references the planned travel line L stored in the storage device 40b and determines whether the body position of the body 3 is located in the turning section L2 (S2c). If the body position of the body 3 is located in the turning section L2 (S2c: Yes), it determines that lowering processing should be performed and transitions to step S3. If the body position of the body 3 is not located in the turning section L2 (S2c: No), it returns to step S1c.

[0073] In the second variant described above, the control device 40 performs the reduction process when the vehicle body 3 is located in the turning section L2, but the reduction process may also be performed when, for example, the vehicle body 3 is located in the straight section L1 and is approaching the vicinity of the turning section L2.

[0074] <Third Modification> In the second variant, the control device 40 determines whether or not to perform the lowering process based on the planned travel line L and the position of the vehicle body 3 as the state of the agricultural machine 100. However, the control device 40 may determine whether or not to perform the lowering process based on the type of operating tool used to operate the tilling implement 2 instead of, or in addition to, the state of the agricultural machine 100 described above.

[0075] As shown in FIG. 2, the agricultural machine 100 is equipped with a control device 50 that can mainly operate the raising and lowering of the tillage implement 2. In this embodiment, the control device 50 includes a first operating device 51, a setting member 50a, and a second operating device 52a. The control device 40 operates the control valve 19 based on an operation signal input from the control device 50. In other words, the control device 40 can drive the lift cylinder 8e connected to the control valve 19. The control device 40 can adjust the height of the tillage implement 2 by driving the lift cylinder 8e.

[0076] The agricultural machine 100 is equipped with a first operating device 51 that operates the lifting device 8 and raises the tiller implement 2 to a desired height. The first operating device 51 is a member (position lever) that controls the raising and lowering of the tiller implement 2. By operating the first operating device 51, the angle of the lift arm 8a (second set angle) can be set. As shown in FIG. 4C, as the angle of the lift arm 8a increases, the height of the tiller implement 2 increases in proportion to the angle of the lift arm 8a. In other words, by operating the first operating device 51, the operator can set the height (second set position) of the tiller implement 2 to a desired position.

[0077] The setting member 50a is, for example, a dial-shaped switch, and is a member that sets the upper limit angle (first set angle) of the angle of the lift arm 8a. In other words, the setting member 50a is a member that sets the upper limit height (first set position) of the tillage implement 2. The amount of operation of the setting member 50a and the first set angle (first set position) are proportional, and by adjusting the amount of operation of the setting member 50a, the upper limit angle of the lift arm 8a (upper limit height of the tillage implement 2) can be set as desired. The setting member 50a may also be a selector switch with multiple switching positions.

[0078] The setting values ​​(second set angle, second set position) set by the first operating device 51 are input to the control device 40. The setting values ​​(first set angle, first set position) set by the setting member 50a are also input to the control device 40. The control device 40 controls the control valve 19 based on the detection results of the cylinder stroke sensor or potentiometer (such as the current angle of the lift arm 8a or the height of the tiller implement 2) and the setting values ​​(first set angle, first set position, second set angle, second set position).

[0079] The lift switch 52 is a member that is operated to lift and lower the tiller 2 to a predetermined set height. An operation signal of the lift switch 52 is input to the control device 40. The lift switch 52 includes a second operating device (up switch) 52a and a lowering switch 52b. In other words, the agricultural machine 100 is equipped with a second operating device 52a that is different from the first operating device 51 and operates the lifting device 8 to raise the tiller implement 2 to a predetermined height. When the lift switch 52 is operated, the control device 40 controls the control valve 19 based on the detection results of the cylinder stroke sensor or potentiometer and the setting values ​​(first set angle, first set position, second set angle, second set position). When the second operating device 52a is operated, the tiller implement 2 is raised to the upper limit height (first set position) set by the setting member 50a, while when the lowering switch 52b is operated, the tiller implement 2 is lowered to the position set by the first operating device 51 (second set position).

[0080] The first operating device (position lever) 51 can be operated in two ways: to adjust the height of the tilling implement 2 while maintaining the working state C1, and to transition from the working state C1 to the non-working state C2. Meanwhile, the second operating device (raise switch) 52a raises the tilling implement 2 to a predetermined height (first set position) previously set by the setting member 50a. Therefore, when the second operating device 52a is operated, it can be determined that the tilling implement 2 will transition from the working state C1 to the non-working state C2. Therefore, the control device 40 performs a lowering process when the second operating device 52a is operated to raise the tilling implement 2.

[0081] As shown in Fig. 12, the control device 40 determines whether the second operating tool 52a has been operated (S2d). Specifically, the control device 40 detects whether an operation signal for raising the tillage implement 2 has been input from the second operating tool 52a. If an operation signal from the second operating tool 52a is detected (S2d: Yes), the control device 40 transitions to step S3.

[0082] The agricultural machine 100 also includes a third operating device 53 that is different from the first operating device 51 and that accepts operation. In this embodiment, the agricultural machine 100 can execute a series of operations (operation sequence). The operation sequence includes a turning operation in which the agricultural machine 100 turns. The control device 40 controls the turning operation in which the tiller implement 2 is raised by the lifting device 8 and the vehicle body 3 is turned by the traveling device 4 in response to operation of the third operating device 53. The turning operation includes raising and lowering the lifting device 8, changing the speed of the traveling device 4, and the like. Specifically, when the third operating device 53 is operated, the control device 40 first raises the lifting device 8 and transitions the vehicle body 3 from the working state C1 to the non-working state C2. Next, the control device 40 controls the traveling device 4 and the steering device 11 to turn the vehicle body 3, and then lowers the lifting device 8 and transitions the vehicle body 3 from the non-working state C2 to the working state C1. At this time, the lifting device 8 raises the tiller implement 2 to the upper limit height (first set position) set by the setting member 50a. The operation sequence is registered in advance by the manufacturer, the operator, etc., and stored in the storage device 40b. When the third operating tool 53 is operated, the control device 40 controls each part of the agricultural machine 100 based on the operation sequence stored in the storage device 40b.

[0083] Therefore, when the operation sequence to be executed by operating the third operating device 53 is a turning operation, the control device 40 can determine, based on the operation of the third operating device 53, whether or not the agricultural machine 100 will transition from the working state C1 to the non-working state C2.

[0084] As shown in FIG. 13, the control device 40 determines whether the third operating device 53 has been operated (S2e). More specifically, the control device 40 detects whether an operation signal has been input from the third operating device 53. When an operation signal from the third operating device 53 is detected (S2e: Yes), the control device 40 determines whether the tilling implement 2 is raised (S2f). For example, the control device 40 detects the actuation of the control valve 19 of the lifting device 8, and determines whether the tilling implement 2 connected to the lifting device 8 is raised by the extension and contraction of the lift cylinder 8e. When it determines that the tilling implement 2 is raised (S2f: Yes), the control device 40 transitions to step S3.

[0085] The setting member 50a sets the upper limit of the height that the tillage implement 2 can be raised, the lift switch 52 raises or lowers the tillage implement 2 to a predetermined set height, and the third operating device 53 controls the execution of a pre-stored operation sequence. For example, if the tractor 1 is provided with a display unit that displays information about the tractor 1 and the display unit is a control device 50 such as a touch panel, the setting member 50a, the lift switch 52 (second operating device 52a), and the third operating device 53 may be areas (switches) displayed on the display unit.

[0086] <Fourth Modification> In the third variant, the control device 40 determines whether or not to perform the lowering process based on the type of operating tool used to raise the tillage implement 2 as the state of the agricultural machine 100. However, the control device 40 may determine whether or not to perform the lowering process based on the tillage depth X of the tillage implement 2 (tillage tines 2A) instead of, or in addition to, the state of the agricultural machine 100 described above.

[0087] As shown in FIG. 2, the agricultural machine 100 is equipped with a tillage depth calculation unit 42 that calculates the tillage depth X (see FIG. 1) of the tillage implement 2. The tillage depth calculation unit 42 is stored in the storage device 40b of the control device 40 and is a program executed by the control device 40. The tillage depth calculation unit 42 (storage device 40b) has dimensional information of the tractor 1 and the tillage implement 2 stored in advance. The tillage depth calculation unit 42 also stores an arithmetic expression (tilling depth calculation program) that calculates the tillage depth X using the dimensional information of the tractor 1 and the tillage implement 2 and the height from the ground surface G to the tillage implement 2 as input parameters. The tillage depth calculation unit 42 also stores an arithmetic expression (height conversion program) that converts height information h detected by the height detection device 72 into the height from the ground surface G to the tillage implement 2. When a calculation instruction signal is input from the control device 40, the tillage depth calculation unit 42 executes a height conversion program and a tillage depth calculation program to calculate the tillage depth X of the tillage implement 2. Note that the calculation of the tillage depth X is not limited to the above-described method, and other methods may also be used.

[0088] The control device 40 can also provide assistance with tillage work based on the tillage depth X calculated by the tillage depth calculation unit 42. For example, the control device 40 notifies the operator of the difference between the calculated tillage depth X and a reference tillage depth Xsd. The reference tillage depth Xsd is registered in advance by the operator or the like and stored in the storage device 40b. When the control device 40 acquires the tillage depth X from the tillage depth calculation unit 42, it calculates the deviation ΔX between the tillage depth X and the reference tillage depth Xsd stored in the storage device 40b. The control device 40, for example, displays the tillage depth X, the reference tillage depth Xsd, and the deviation ΔX on a display unit provided on the tractor 1. By looking at the display unit, the operator can understand the difference between the tillage depth X for the currently being performed tillage work and the reference tillage depth Xsd. This allows the operator to determine whether the tillage work is being performed appropriately. Furthermore, when the operator sees by the display that the deviation ΔX between the tilling depth X and the standard tilling depth Xsd is large, he or she can operate the control device 50 to adjust the position (height) of the tilling implement 2 so that the deviation ΔX becomes smaller (so that the tilling depth X matches the standard tilling depth Xsd).

[0089] The control device 40 determines whether or not to perform a reduction process based on the tillage depth X calculated by the tillage depth calculation unit 42. As described above, when the vehicle body 3 turns, the agricultural machine 100 raises the tillage implement 2 and transitions to the non-working state C2 in order to turn smoothly and prevent damage to the tillage implement 2. Furthermore, when the agricultural machine 100 finishes tilling work, it transitions from the working state C1 to the non-working state C2 so that the tillage implement 2 (the tillage tines 2A) are away from the ground G. For this reason, when the tillage depth X calculated by the tillage depth calculation unit is smaller than a predetermined value, it is expected that the agricultural machine 100 will raise the tillage implement 2 (the tillage tines 2A) above the ground G and perform an operation to turn the vehicle body 3, or will stop tilling work.

[0090] On the other hand, it is also conceivable that the operator will grasp the deviation ΔX between the tilling depth X and the reference tilling depth Xsd by looking at the display unit, and will operate the first operating tool 51 to adjust the position (height) of the tilling implement 2 to a desired position while continuing the working state C1. For example, if the tilling depth X is shallower (smaller) than the reference tilling depth Xsd, the operator will operate the first operating tool 51 to lower the position (height) of the tilling implement 2 so as to reduce the deviation ΔX. When the tilling depth X is less than the reference tilling depth Xsd, the control device 40 can determine that the working state C1 will transition to the non-working state C2 at least if the first operating tool 51 is operated to raise the tilling implement 2 and the tilling depth X further decreases. For this reason, the control device 40 determines whether to perform a reduction process when the first operating tool 51 is operated to raise the tillage implement 2 and the tillage depth X is less than a predetermined value (for example, a reference tillage depth Xsd or a predetermined tillage depth Xth (Xsd>Xth) that is smaller than the reference tillage depth Xsd). For example, the memory device 40b has stored in advance a predetermined tillage depth Xth (Xsd>Xth) that is smaller than the reference tillage depth Xsd, and the control device 40 can determine whether the tillage depth X is equal to or smaller than the predetermined tillage depth Xth.

[0091] As shown in FIG. 14, the control device 40 determines whether the first operating tool 51 has been operated (S 2g). More specifically, the control device 40 detects whether an operation signal has been input from the first operating device 51. When the control device 40 detects an operation signal from the first operating device 51 (S2g: Yes), it determines whether the tillage implement 2 is raised (S2f). When the control device 40 determines that the tillage implement 2 is raised (S2f: Yes), it acquires the tillage depth X from the tillage depth calculation unit 42 (S1d) and determines whether the tillage depth X is equal to or less than a predetermined value (S2h). If the tillage depth X is equal to or less than the predetermined value (S2h: Yes), the control device 40 determines that a lowering process should be performed and transitions to step S3.

[0092] The control device 40 may also perform automatic lifting control, which automatically adjusts the position of the tillage implement 2 so that the tillage depth X matches the reference tillage depth Xsd. Specifically, when the operator performs a predetermined operation, the control device 40 starts the automatic lifting control. In the automatic lifting control, if the tillage depth X calculated by the tillage depth calculation unit 42 is smaller (shallower) than the reference tillage depth Xsd, the control device 40 inputs a control signal to the control valve 19 to lower the tillage implement 2 (lifting device 8) and moves the tillage tine 2A downward, thereby controlling the tillage depth X to match the reference tillage depth Xsd. If the tillage depth X is larger (deeper) than the reference tillage depth Xsd, the control device 40 inputs a control signal to the control valve 19 to raise the tillage implement 2 (lifting device 8) and moves the tillage tine 2A upward, thereby controlling the tillage depth X to match the reference tillage depth Xsd. This allows the agricultural machine 100 to maintain a constant tillage depth X, thereby enabling the agricultural machine 100 to perform tillage work appropriately.

[0093] When the control device 40 is performing automatic lift-down control, it can be said that the working state C1 is continuing. On the other hand, when the control device 40 is performing automatic lift-down control, if the tillage implement 2 is raised by an operation signal from the first operating device 51 and the tillage depth X decreases, it can be determined that the agricultural machine 100 will transition to the non-working state C2. Therefore, when the control device 40 is performing automatic lift-down control, the control device 40 determines whether or not to continue the automatic lift-down control based on the operation of the first operating device 51. If the control device 40 determines not to continue the automatic lift-down control, it determines whether or not to perform a reduction process based on the tillage depth X.

[0094] As shown in FIG. 15, when the control device 40 receives a predetermined operation, it starts automatic lifting / lowering control (S4). The control device 40 determines whether the first operating device 51 has been operated (S2g). When the control device 40 detects an operation signal from the first operating device 51 (S2g: Yes), it ends the automatic lifting / lowering control (S5) and determines whether the tillage implement 2 is raised (S2f). When the control device 40 determines that the tillage implement 2 is raised (S2f: Yes), it acquires the tillage depth X from the tillage depth calculation unit 42 (S1d) and determines whether the tillage depth X is equal to or less than a predetermined value (S2h). When the tillage depth X is equal to or less than the predetermined value (S2h: Yes), the control device 40 determines that a lowering process should be performed and proceeds to step S3.

[0095] <Other variations> In the above-described embodiment, the control device 40 provided in the tractor 1 determines whether or not to perform the lowering process, but it may also be linked to the work control device 2a provided in the tillage implement 2. For example, the height detection device 72 may be provided in the tillage implement 2, and the work control device 2a may operate as the tillage depth calculation unit 42, outputting the detected tillage depth X to the control device 40 via the network N.

[0096] Furthermore, in the above-described embodiment, the electric motor M1, which is the drive source of the tillage implement 2, and the power storage device 30, which supplies power to the electric motor M1, are provided in the tractor 1 (body 3), but they may also be provided in the tillage implement 2. In this case, a function equivalent to the reduction processing unit 41 is stored as a software program in the work control device 2a, and the electric motor M1 is controlled by executing the software program.

[0097] Furthermore, in the above-described embodiment, the agricultural machine 100 has been described as having power transmitted from different drive sources (electric motors M1, M2) to the tiller 2 and the traveling device 4, respectively. However, the drive source of the tiller 2 may also serve as the power source for the traveling device 4, etc. In such a case, power output from the drive source (electric motor M1, internal combustion engine, etc.) is transmitted to the transmission 5, and the traveling device 4 and the tiller 2 are driven by the power whose speed has been changed by the transmission 5. In other words, the power output from the drive source is output to the PTO shaft 16, which outputs the power to the outside, via the transmission 5. In this modified example, the transmission 5 has a PTO power transmission section that transmits the power output from the drive source to the PTO shaft 16 and changes the speed of the power.

[0098] The PTO power transmission unit includes a PTO propeller shaft, a PTO clutch, and a PTO speed change unit. The PTO propeller shaft is rotatably supported and can transmit power from a drive source. The PTO clutch is, for example, a hydraulic clutch, and by engaging or disengaging the hydraulic clutch, the state switches between transmitting power from the propeller shaft to the PTO propeller shaft and not transmitting power from the propeller shaft to the PTO propeller shaft. The PTO speed change unit includes a speed change clutch and multiple gears, and changes and outputs the power (rotation speed) input from the PTO propeller shaft to the PTO speed change unit. The power of the PTO speed change unit is connected to the PTO shaft via gears, etc. The PTO speed change unit changes and outputs the power (rotation speed) to the PTO shaft 16 based on a control signal output from the control device 40. The reduction processing unit 41 outputs a control signal to the PTO speed change unit to change the speed of the PTO shaft 16 and change (reduce) the rotation speed V of the tiller tines 2A.

[0099] A preferred embodiment of the present invention provides an agricultural machine 100 as described in the following items.

[0100] (Item A1) An agricultural machine 100 comprising a vehicle body 3, a traveling device 4 that supports the vehicle body 3 so that it can run, a tillage implement 2 having rotatably driven tillage tines 2A, a lifting device 8 that connects the tillage implement 2 to the vehicle body 3 so that it can be raised and lowered, and a control device 40 that performs a reduction process to gradually reduce the output of power that rotates and drives the tillage implement tines 2A as the tillage implement 2 transitions from a working state C1 in which it is performing work to a non-working state C2 in which the lifting device 8 raises the tillage implement 2 and the tillage implement 2 is not performing work.

[0101] According to the invention related to this item A1, the ground surface G can be maintained in an appropriate state when transitioning from working state C1 to non-working state C2 in which the tillage implement 2 is not working. Specifically, by performing a reduction process that gradually reduces the drive of the tillage tines 2A during the transition from working state C1 in which the tillage tines 2A are digging into the ground and tilling it to non-working state C2 in which the tillage tines 2A are positioned above the ground surface, the amount of soil that the tillage tines 2A dig out of the ground during the transition from working state C1 to non-working state C2 can be gradually reduced, and the formation of tillage marks on the ground surface G after work can be suppressed.

[0102] (Item A2) An agricultural machine 100 as described in Item A1, which is provided with a drive source that generates power to rotate the tiller tines 2A, and the control device 40 controls the output and / or rotational speed of the power transmitted from the drive source to the tiller tines 2A as the reduction process, thereby gradually reducing the rotational speed V of the tiller tines 2A.

[0103] According to the invention relating to item A2, by performing a reduction process to gradually reduce the rotational speed V of the tiller tines 2A during the transition from the working state C1 in which the tiller tines 2A are digging into the ground and tilling to the non-working state C2 in which the tiller tines 2A are positioned above the ground, the number of times the tiller tines 2A come into contact with the ground during the transition from the working state C1 to the non-working state C2 can be reduced, and the ground G can be maintained in an appropriate state.

[0104] (Item A3) An agricultural machine 100 according to item A2, which is equipped with a height detection device 72 that detects height information h of the lifting device 8 and / or the tilling device 2 from the field, and the control device 40 performs the lowering process based on the height information h detected by the height detection device 72.

[0105] According to the invention relating to this item A3, the control device 40 can determine that the lifting device 8 and / or the tilling device 2 are at a height to transition to the non-working state C2, and can perform a lowering process.

[0106] (Item A4) The agricultural machine 100 described in Item A3, in which the traveling device 4 changes the degree of straightness of the vehicle body 3 by changing the steering angle, and the control device 40 determines whether or not to perform the reduction processing based on the steering angle.

[0107] According to the invention related to this item A4, the control device 40 can estimate (determine) a transition to the non-working state C2 by using the steering angle as a substitute, without detecting an operation instruction to transition to the non-working state C2. Therefore, the control device 40 can appropriately determine, based on the steering angle, whether the traveling device 4 will continue in the working state C1 by moving straight, or whether the vehicle body 3 will turn and transition to the non-working state C2, and perform the reduction process.

[0108] (Item A5) The agricultural machine 100 according to item A4, wherein the control device 40 performs the reduction process when the steering angle is equal to or greater than a predetermined value.

[0109] According to the invention related to this item A5, the control device 40 receives an operation instruction for transitioning to the non-working state C2. Even if the steering angle is equal to or greater than a predetermined value, it is possible to estimate (determine) that the traveling device 4 will turn and transition to the non-working state C2, and to carry out appropriate reduction processing. Furthermore, it is possible to maintain the rotational drive output of the tillage tines 2A and perform tillage when the vehicle body 3 travels straight, and to carry out reduction processing when the traveling device 4 turns and transitions to the non-working state C2, thereby preventing tillage marks from being left on the ground G.

[0110] (Item A6) An agricultural machine 100 according to any one of items A3 to A5, which is provided with a memory device 40b that stores a field map MP showing a field, and the control device 40 determines whether or not to perform the reduction processing based on the position of the vehicle body 3 on the field map MP.

[0111] According to the invention relating to this item A6, the control device 40 can estimate (determine) the transition to the non-working state C2 by using the position of the vehicle body 3 on the field map MP as a substitute, without detecting an operation instruction to transition to the non-working state C2, and can perform the reduction processing appropriately.

[0112] (Item A7) The agricultural machine 100 described in Item A6, wherein the field map MP includes a turning area E1 in which the vehicle body 3 turns, and the control device 40 performs the reduction processing when the vehicle body 3 approaches the vicinity of the turning area E1 and / or is located in the turning area E1.

[0113] According to the invention related to item A7, the control device 40 can estimate (determine) that the vehicle body 3 will turn and transition to the non-working state C2 by using the position of the vehicle body 3 in the field map MP as a substitute, without detecting an operation instruction to transition to the non-working state C2. This makes it possible to cultivate while maintaining the rotational drive output of the tiller tines 2A in the working state C1, and to reduce the amount of tillage marks left on the ground G when transitioning to the non-working state C2.

[0114] (Item A8) An agricultural machine 100 according to any one of items A3 to A7, comprising a memory device 40b that stores a planned driving line L, which is defined in a field and is the route along which the vehicle body 3 will travel, and the control device 40 determines whether or not to perform the lowering processing based on the position of the vehicle body 3 on the planned driving line L.

[0115] According to the invention relating to this item A8, the control device 40 can estimate (determine) the transition to the non-working state C2 by using the position of the vehicle body 3 on the planned driving line L as a substitute, without detecting an operation instruction to transition to the non-working state C2, and can perform appropriate reduction processing.

[0116] (Item A9) The planned driving line L includes a straight section L1 along which the vehicle body 3 drives straight and a turning section L2 along which the vehicle body 3 drives in a turning direction, and the control device 40 performs the lowering processing when the vehicle body 3 is located at the turning section L2, in the agricultural machine 100 described in item A8.

[0117] According to the invention relating to item A9, the control device 40 can estimate (determine) that the vehicle body 3 will transition to the non-working state C2 as it is positioned in the turning section L2 and turns, even without detecting an operation instruction to transition to the non-working state C2, and can appropriately perform the reduction processing.

[0118] (Item A10) An agricultural machine 100 described in any of items A3 to A9, comprising a first operating device 51 that operates the lifting device 8 and raises the tilling implement 2 to any height, and a second operating device 52a that is different from the first operating device 51 and operates the lifting device 8 and raises the tilling implement 2 to a predetermined height, wherein the control device 40 performs the lowering processing when the second operating device 52a is operated and the tilling implement 2 is raised.

[0119] According to the invention related to this item A10, the first operating tool 51 is used to arbitrarily adjust the height of the tillage implement 2. Therefore, the first operating tool 51 is assumed to be operated both to adjust the height of the tillage implement 2 while maintaining the working state C1, and to transition from the working state C1 to the non-working state C2. Meanwhile, the second operating tool 52a can be estimated (determined) to be operating to raise the tillage implement 2 to a predetermined height in order to transition from the working state C1 to the non-working state C2. Therefore, even if there is no operation indicating a transition to the non-working state C2, the control device 40 can estimate that the second operating tool 52a has been operated to transition to the non-working state C2, and by appropriately performing a lowering process, the ground G can be maintained in an appropriate state.

[0120] (Item A11) The tiller is provided with a first operating tool 51 that operates the lifting device 8 and raises the tilling device 2 to a desired height, and a third operating tool 53 that is different from the first operating tool 51 and accepts operation, and the control device 40 controls the lifting device 8 in response to operation of the third operating tool 53. Therefore, the agricultural machine 100 described in any of items A3 to A10 controls a turning operation in which the tilling implement 2 is raised and the traveling device 4 turns the vehicle body 3, and performs the lowering processing when the turning operation is performed.

[0121] According to the invention pertaining to this item A11, the first operating device 51 is used to arbitrarily adjust the height of the tillage implement 2. For this reason, it is conceivable that the first operating device 51 will be operated to adjust the height of the tillage implement 2 while maintaining the working state C1. On the other hand, the third operating device 53 can be operated to combine raising of the tillage implement 2 and turning of the vehicle body 3. Therefore, even if there is no operation to indicate a transition to the non-working state C2, the control device 40 can estimate (determine) that operation of the third operating device 53 will result in a transition from the working state C1 to the non-working state C2, and can appropriately perform the lowering process.

[0122] (Item A12) An agricultural machine 100 according to any one of items A3 to A11, which is provided with a tillage depth calculation unit 42 that calculates the tillage depth X of the tillage implement 2, and the control device 40 determines whether or not to perform the reduction processing based on the tillage depth X calculated by the tillage depth calculation unit 42.

[0123] According to the invention relating to this item A12, the control device 40 can use the tillage depth X as a substitute to estimate (determine) whether to continue the working state C1 or to transition to the non-working state C2, even without any operation to indicate that the working state C2 has been transitioned to, and can appropriately perform the reduction process.

[0124] (Item A13) The agricultural machine 100 described in item A12 is provided with a first operating device 51 that operates the lifting device 8 and raises the tilling implement 2 to any height, and the control device 40 determines whether to perform the lowering process when the first operating device 51 is operated to raise the tilling implement 2 and the tilling depth X is less than a predetermined value.

[0125] According to the invention relating to this item A13, even if there is no operation to indicate that the non-working state C2 has been entered, the control device 40 can use the operation by the first operating device 51 and the tillage depth X as a substitute to estimate (determine) whether to continue the working state C1 or to enter the non-working state C2, and can perform the reduction process appropriately.

[0126] (Item A14) The agricultural machine 100 described in any one of items A2 to A13, wherein the drive source is an electric motor M1 driven by electricity, and the control device 40 controls the output and / or rotation speed of the electric motor M1 in the reduction process, and gradually reduces the rotation speed V of the tiller tines 2A as the state transitions from the working state C1 to the non-working state C2.

[0127] According to the invention relating to item A14, when transitioning from working state C1 to non-working state C2, the rotational speed V of the tiller tines 2A is gradually reduced by controlling the electric motor M1, thereby suppressing the occurrence of tillage marks on the ground G and maintaining the ground in an appropriate state.

[0128] (Item A15) The agricultural machine 100 described in Item A14, wherein the control device 40 controls the electric motor M1 in the reduction process to continuously reduce the rotational speed V of the tiller tines 2A as the state transitions from the working state C1 to the non-working state C2.

[0129] According to the invention relating to item A15, when transitioning from working state C1 to non-working state C2, the tillage implement 2 is pulled, thereby reducing the load that the tillage tines 2A receive from the ground, while reducing the amount of soil that the tillage tines 2A dig into the ground, thereby suppressing the occurrence of tillage marks on the ground G.

[0130] Although the present invention has been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0131] 2: Tillage device 2A: Cultivating claw 3: Body 4: Running gear 8: Lifting device 40: Control device 40b: Storage device 42: Tillage depth calculation unit 51: 1st operating tool 52a: 2nd operating tool 53:Third operating tool 72: Height detection device 100:Agricultural machinery C1: Working status C2: Non-working state E1: Turning area L: Planned driving line L1: Straight section L2: Swivel part M1: Electric motor MP: Field Map V: Rotation speed X: Tillage depth h: Height information

Claims

1. The car body and a traveling device that supports the vehicle body so that it can travel; A tillage device having rotationally driven tillage tines; A lifting device that connects the tilling implement to the vehicle body so that it can be raised and lowered; A control device that performs a reduction process to gradually reduce the power output that rotates the tilling tines as the tilling implement moves from a working state in which the tilling implement is working to a non-working state in which the lifting device raises the tilling implement and the tilling implement is not working; Agricultural machinery equipped with

2. A drive source is provided that generates power to rotate the tillage tines, The agricultural machine according to claim 1 , wherein the control device controls the output and / or rotation speed of the power transmitted from the drive source to the tiller tines as the reduction process, thereby gradually reducing the rotation speed of the tiller tines.

3. A height detection device is provided to detect height information of the lifting device and / or the tilling device from the field, The agricultural machine according to claim 2 , wherein the control device performs the lowering process based on the height information detected by the height detection device.

4. the traveling device changes the degree of straightness of the vehicle body by changing a steering angle; The agricultural machine according to claim 3 , wherein the control device determines whether or not to perform the reduction process based on the steering angle.

5. The agricultural machine according to claim 4 , wherein the control device performs the reduction process when the steering angle is equal to or greater than a predetermined value.

6. a storage device that stores a field map showing the field; The agricultural machine according to claim 3 , wherein the control device determines whether or not to perform the lowering process based on the position of the vehicle body on the field map.

7. the field map includes a turning area in which the vehicle body turns, The agricultural machine according to claim 6 , wherein the control device performs the reduction process when the vehicle body approaches the vicinity of the turning area and / or is located in the turning area.

8. a storage device that stores a planned travel line that is defined in the field and is a route along which the vehicle body will travel; The agricultural machine according to claim 3 , wherein the control device determines whether or not to perform the lowering process based on a position of the vehicle body on the planned travel line.

9. the planned traveling line includes a straight section along which the vehicle body travels straight and a turning section along which the vehicle body travels turning, The agricultural machine according to claim 8 , wherein the control device performs the lowering process when the vehicle body is located at the turning section.

10. A first operating tool that operates the lifting device and raises the tilling device to an arbitrary height; A second operating tool different from the first operating tool and operating the lifting device to raise the tilling tool to a predetermined height; Equipped with The agricultural machine according to claim 3 , wherein the control device performs the lowering process when the second operating tool is operated to raise the tilling implement.

11. A first operating tool that operates the lifting device and raises the tilling device to an arbitrary height; a third operating tool different from the first operating tool and adapted to receive an operation; Equipped with The control device In response to the operation of the third operating tool, the lifting device is used to lift the tilling implement, and the traveling device is used to control a turning operation to turn the vehicle body; 4. The agricultural machine according to claim 3, wherein the lowering process is performed when the turning operation is performed.

12. A tillage depth calculation unit is provided to calculate the tillage depth of the tillage device, The agricultural machine according to claim 3 , wherein the control device determines whether or not to perform the reduction process based on the tilling depth calculated by the tilling depth calculation unit.

13. A first operating tool is provided to operate the lifting device and raise the tilling device to an arbitrary height, The agricultural machine according to claim 12, wherein the control device determines whether to perform the lowering process when the first operating tool is operated to raise the tillage implement and the tillage depth is less than a predetermined value.

14. the drive source is an electric motor driven by electricity, The agricultural machine according to any one of claims 2 to 13, wherein the control device controls the output and / or rotation speed of the electric motor in the reduction process, and gradually reduces the rotation speed of the tiller tines as the state transitions from the working state to the non-working state.

15. The agricultural machine according to claim 14, wherein the control device, in the reduction process, controls the electric motor to continuously reduce the rotational speed of the tiller tines as the agricultural machine transitions from the working state to the non-working state.

Images