JP2013188161A - Lawn mowing vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lawn mowing vehicle, achieving energy-saving according to user's mode selection and realizing the configuration for obtaining an excellent lawn state by an efficient operation.SOLUTION: This lawn mowing vehicle includes an ECU 50. The ECU 50 sets the relationship between the vehicle speed and the mower related target rotational speed to the lawn mowing travel cooperative relationship in which the mower related target rotational speed of a deck motor 46 increases according to an increase in the vehicle speed of the lawn mowing vehicle at least in a predetermined vehicle speed region of the lawn mowing vehicle according to the establishment of preset designated conditions, and controls the deck motor 46 to execute a nice mode which is a lawn mowing travel cooperative mode in which the deck motor 46 is driven at the mower related target rotational speed based on the lawn mowing travel cooperative relationship.

Description

  The present invention relates to a lawnmower vehicle including a drive wheel motor that drives at least one drive wheel, a mower-related motor that drives at least one lawnmower, and at least one controller.

  2. Description of the Related Art Conventionally, a lawnmower vehicle including a working machine that is driven to perform a lawn mowing work is known. Further, in such a lawnmower vehicle, there is also a lawnmower vehicle provided with left and right wheels, which are main drive wheels driven by different or common motors such as an electric motor and a hydraulic motor, and steering wheels such as caster wheels. It is considered.

  For example, there is a lawnmower vehicle capable of running on its own by running and driving a lawn mower on an operator, which is called a riding lawn mower vehicle. An example of a lawn mower is a lawn mowing rotary tool.

  Riding lawn mowers are used exclusively in so-called off-roads such as gardens, and move on the ground for mowing work.

  For example, Patent Document 1 discloses a hybrid power unit equipped with an engine / generator integrated type in which a rotor is connected to an engine shaft of an internal combustion engine. The lawn mower exemplified as a power unit is connected to a plurality of drive wheels with independent electric motors, and each drive wheel can be controlled independently at a variable speed, thereby enabling smooth start and stop of the lawn mower. It is stated that speed change, direction change, and turn can be performed. As examples of turning by changing the independent speed of the drive wheels, there are described cases in which an electric motor is connected to each of the left and right rear wheels. Moreover, there are also Patent Documents 2 to 6 as prior art documents related to the present invention.

Japan Special Table 2006-507789 US Patent Application Publication No. 2005 / 0126145A1 US Patent Application Publication No. 2009 / 0065273A1 Specification US Patent Application Publication No. 2009 / 0069964A1 US Patent Application Publication No. 2009 / 0201650A1 US Patent No. 8055399B2

  2. Description of the Related Art Conventionally, in a lawnmower vehicle, a lawnmower is sometimes switched between driving and stopping by switching on and off a deck switch that is a lawnmower start switch. However, only one mode can be selected when the deck switch is turned on. That is, the lawn mower rotates at a constant rotation speed regardless of the vehicle speed. Further, the vehicle speed is set according to the operation of an operation lever such as an operation lever or an accelerator pedal by a user operation. For this reason, when the vehicle speed is high, the resistance from the turf increases, so that only once the mowing work is done, it is sufficiently clean, that is, a good turf state where most of the turf is aligned to the desired length can be obtained. There is a possibility that it cannot be reaped. On the other hand, it is conceivable to increase the rotation speed of the lawn mower sufficiently. However, in that case, useless over-rotation occurs, fuel and power consumption increase, and this is not preferable in terms of energy saving. . Therefore, it is desired to realize a lawnmower vehicle that can save energy and obtain a good turf state through efficient work. In Patent Document 1 to Patent Document 6 described above, there is room for improvement from the viewpoint of achieving energy saving and realizing a good turf state with efficient work.

  An object of the present invention is to realize a configuration capable of saving energy and obtaining a good turf state with an efficient work in a lawn mower vehicle.

  A first lawnmower vehicle according to the present invention is a lawnmower vehicle including a drive wheel motor that drives at least one drive wheel, a mower-related motor that drives at least one lawn mower, and at least one controller. The at least one controller has a mower-related target rotational speed of the mower-related motor according to an increase in the vehicle speed of the lawnmower vehicle at least in a predetermined vehicle speed region of the lawnmower vehicle by satisfying a predetermined condition set in advance. A lawn in which the relationship between the vehicle speed and the mower-related target rotational speed is set in an increasing lawn mowing traveling cooperative relationship, and the mower-related motor is driven at the mower-related target rotational speed based on the lawn mowing traveling cooperative relationship. A mower-related motor that controls the mower-related motor so as to execute a mowing travel cooperative mode.

  A second lawnmower vehicle according to the present invention comprises a drive wheel motor that drives at least one drive wheel, a mower-related motor that drives at least one lawnmower, and at least one controller. And at least one operation sensor for detecting an operation amount of at least one operation element, and a mode instruction device for instructing switching between the economy mode and at least one other operation mode by a user operation. A mower activation switch that instructs activation of the mower-related motor by a user operation, and the at least one controller calculates a target vehicle speed of the lawnmower vehicle according to a signal from the at least one operator sensor. The operation of the drive wheel motor is controlled according to signals from a vehicle speed calculation unit and the at least one operator sensor. And a mower related control unit that controls the operation of the mower related motor, and when the mode indicating device is switched to the economy mode and the mower start switch is turned on. Sometimes changing the permitted maximum speed of the target vehicle speed of the lawn mower vehicle to an economy maximum speed that is lower than when switching to the other operation mode, and controlling the rotational speed of the drive wheel motor; and The mower-related control unit controls the mower-related motor so as to rotate at a predetermined constant speed.

  According to the lawnmower vehicle according to the present invention, it is possible to realize a lawnmower vehicle that can obtain a good lawn state by efficient work. For example, according to the first lawnmower vehicle, when a predetermined condition is satisfied, the rotational speed of the mower-related motor increases in accordance with the increase in the vehicle speed in at least a predetermined vehicle speed region of the lawnmower vehicle. For this reason, even when the vehicle speed is high, a desired good turf state can be realized in a short working time, and at the low vehicle speed, the rotational speed of the mower-related motor becomes low, so that energy saving can be achieved. Further, a lawnmower vehicle that can obtain a good turf state by an efficient work can be realized.

  Further, according to the second lawnmower vehicle, when the user operates the mode indicating device and switches to the economy mode, when the mower start switch is turned on, the rotational speed of the mower-related motor becomes constant. It is maintained and the maximum vehicle speed is changed to a lower economy maximum speed than when switching to another driving mode, so by allowing driving at a lower maximum speed than in another driving mode, saving is possible. Energy can be achieved. Further, a lawnmower vehicle that can obtain a good turf state by an efficient work can be realized.

It is the schematic which looked at the structure of the lawnmower vehicle of embodiment which concerns on this invention from the upper direction. It is a block diagram which shows the structure of the control system of the lawnmower vehicle of FIG. FIG. 3 is a block diagram illustrating a connection configuration of an ECU, a drive motor controller, and a drive motor in the control system of FIG. 2. In FIG. 3, it is a block diagram which shows the structure of ECU in detail. It is a figure which shows one example of the mode switch shown in FIG. In embodiment which concerns on this invention, it is a figure which shows the relationship between the vehicle speed corresponding to the lawn mowing driving | running | working cooperative relationship set by nice mode, and the peripheral speed of a deck blade. In embodiment which concerns on this invention, it is a figure for demonstrating the rotation speed corresponding to the high efficient constant speed of the deck motor set in economy mode. It is a figure which shows the 1st example of another example of a mode switch. It is a figure which shows the 2nd example of another example of a mode switch. It is a figure which shows the 3rd example of another example of a mode switch.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1-7 illustrate one embodiment of the present invention. FIG. 1 is a schematic view of a configuration of a lawnmower vehicle according to an embodiment of the present invention as viewed from above. FIG. 1 shows a case where a left and right lever type operation element 44 having two left and right operation levers 40 and 42 is used as a structure having both functions of a turning instruction tool and an acceleration instruction tool. A certain steering operator can be used as a turning indicator, and an accelerator pedal, which is an operator provided on the front side of the seat, can also be used as an acceleration indicator. In the following, a case where three deck motors are provided in the lawnmower vehicle 10 will be described. However, one, two, or four or more deck motors may be provided in the lawn mower vehicle.

  As shown in FIG. 1, a lawn mower vehicle 10 that is a riding-type ground working vehicle without an engine is a self-propelled off-road vehicle suitable for lawn mowing, and is a front-rear direction of the main frame 12 (left and right in FIG. The two left and right caster wheels 14 and 16 and the two left and right wheels 18 and 20 are supported and provided at positions separated in the direction). The left and right caster wheels 14 and 16 are front wheels and steered wheels. The two left and right wheels 18 and 20 are rear wheels and are main drive wheels. Each of the left and right wheels 18 and 20 is two left and right traveling rotary electric machines, and is independently driven by left and right drive motors 22 and 24 that are drive wheel electric motors. That is, the left and right drive motors 22 and 24 are connected to the left and right wheels 18 and 20 via a power transmission unit including a reduction mechanism (not shown) so that power can be transmitted.

  By making the rotational speeds of the left and right wheels 18 and 20 coincide with each other by the left and right drive motors 22 and 24, the vehicle can travel straight, and by generating a difference in rotational speed between the left and right wheels 18 and 20, the vehicle can turn. Make it possible. Thus, the lawnmower vehicle 10 includes the drive motors 22 and 24 as drive sources. Moreover, the reduction mechanism provided in a power transmission part uses the reduction gear apparatus of 1 step | paragraph or multiple steps | paragraphs, for example. In FIG. 1, power generation units 26 and 28 are provided corresponding to the left and right wheels 18 and 20, and drive motors 22 and 24, a reduction mechanism (not shown) are provided in a housing 30 constituting each power generation unit 26 and 28. Are provided. Each housing 30 is supported by the main frame 12. In addition, you may employ | adopt the structure which transmits the motive power of the drive motors 22 and 24 to the right-and-left wheels 18 and 20 without decelerating through a deceleration mechanism. Further, the caster wheels 14 and 16 are capable of free steering of 360 degrees or more around the axis in the vertical direction (front and back direction in FIG. 1).

  The lawnmower vehicle 10 includes a lawn mower (mower) 32 that is a working machine supported on the lower side in the front-rear direction intermediate portion of the main frame 12. The lawn mower includes one or a plurality of lawn mowing blades (not shown), which is a lawn mowing rotating tool that is rotatable about a vertical axis inside the mower deck 34. The lawn mowing blade includes a plurality of cutting blade elements arranged around a vertical axis, and the cutting blade element is rotated so that the lawn or the like can be broken and mowed.

  Further, each of the drive motors 22 and 24 is driven by power supplied from a battery 36 (FIG. 2 and the like) as a power source. The battery 36 can employ a lead storage battery, a nickel metal hydride battery, a lithium battery, or the like, and has a voltage of 48 V, for example. The battery 36 can be charged from an external commercial AC power source via a charger.

  The lawnmower vehicle 10 may be a so-called hybrid type equipped with an engine and a generator. In this case, a generator is generated using the power of the engine, and the generated power can be supplied to the battery 36. In addition, as a power source, a battery 36 having a self-power generation function such as a fuel cell or a solar cell can be used together with the battery 36 that is supplied with charging power from the outside. Further, another power source such as a capacitor may be used instead of the battery 36.

  Further, the rotating shaft of a mower-related blade (not shown) provided inside the mower deck 34 is a corresponding mower-related motor, and the rotating shaft (not shown) of the deck motor 46 (FIG. 2), which is an electric motor, transmits power. Connected as possible. FIG. 2 shows a case where three deck motors 46 are provided. Electric power is supplied to each deck motor 46 from a battery 36 (FIG. 2).

  FIG. 2 is a block diagram showing the configuration of the control system for the lawnmower vehicle of FIG. As shown in FIG. 2, a deck switch 47, which is a mower activation switch for instructing activation of the deck motor 46 by a user operation, is provided near a seat (not shown) provided on the upper side of the main frame 12 (FIG. 1). When a signal indicating whether the deck switch 47 is on or off is input to an ECU (Electronic Control Unit) 50 that is a host controller constituting the controller unit 48 (FIG. 1), the ECU 50 1 A command signal is output to the deck motor controller 52 which is one or a plurality of subordinate controllers, and the operating state of each deck motor 46 is controlled. That is, the deck motor controller 52 includes a deck inverter (not shown) that is a driver that drives the deck motor 46 and a control circuit (not shown) that controls the deck inverter. The control circuit of the deck motor controller 52 includes a storage unit such as a CPU and a memory, and a signal representing the target rotational speed that is the target rotational speed of the deck motor 46 from the ECU 50 and is the rotational speed per unit time is supplied to the deck inverter. Entered. Each deck inverter controls the corresponding deck motor 46 to rotate at the target rotational speed. Each deck motor controller 52 is connected to the ECU 50 via a CAN communication line.

  Returning to FIG. 1, the lawnmower vehicle 10 cuts the turf by driving the deck motor 46 (FIG. 2), and discharges the cut turf from the inside of the mower deck 34 to one side in the vehicle width direction. It is also possible to mount a grass collection tank (not shown) on the lawn mowing vehicle 10 and connect the grass collection tank and the mower deck 34 by a duct so that the cut grass can be collected in the grass collection tank.

  In addition to the lawn mowing blade type, the lawn mowing rotary tool has a configuration in which, for example, a spiral blade is arranged in a cylinder having a rotation axis parallel to the ground surface, and the lawn is sandwiched and mowed. A lawn mower reel driven by a deck motor can also be used.

  The left and right caster wheels 14 and 16 are supported at the same position in the front-rear direction (left-right direction in FIG. 1) of the front side (left side in FIG. 1) of the main frame 12. Further, a seat (not shown) is provided on the upper surface side of the intermediate portion in the left-right direction (vertical direction in FIG. 1) in the middle portion in the front-rear direction of the main frame 12. In the present specification, the front side refers to the front side of the vehicle on the left side of FIG. 1, and the rear side refers to the rear side of the vehicle on the right side of FIG. The left and right wheels 18 and 20 are supported at the same position in the front-rear direction on the rear side of the main frame 12. As the main frame 12, a metal material such as a steel material can be used and formed into a beam structure or the like. A support portion such as a plate portion (not shown) for supporting the seat and the operation portions such as the left and right operation levers 40 and 42 is fixed to the upper side of the main frame 12.

  In addition, the caster wheels 14 and 16 other than two, for example, only one can also be provided in the lawnmower vehicle 10, and three or more can also be provided. In the present embodiment, the left and right wheels 18 and 20 that are main driving wheels are used as rear wheels, and the caster wheels 14 and 16 are used as front wheels, but the left and right wheels 18 and 20 that are main driving wheels are used as front wheels. 14 and 16 can be rear wheels.

  The drive motors 22 and 24 have a function of outputting rotational driving force to the wheels 18 and 20 when electric power is supplied, but a generator that recovers regenerative energy when the wheels are braked. You may give the function as. The drive motors 22 and 24 are, for example, permanent magnet type three-phase synchronous electric motors or induction electric motors.

  The lawn mower vehicle 10 is provided with the above-described controller unit 48. The controller unit 48 is an upper controller, and an ECU 50 (FIG. 2) that comprehensively controls the drive motors 22, 24 and the deck motor 46 (FIG. 2). The left drive motor controller 54 and the right drive motor controller 56 (FIG. 2) corresponding to the left and right drive motors 22 and 24 are integrally provided. As shown in FIG. 2, the drive motor controllers 54 and 56 are connected to the ECU 50 through a CAN communication line that is a signal cable. It should be noted that the deck motor controller 52 may be provided integrally with the controller unit 48, and the motor controllers 52, 54, and 56 and the ECU 50 may be separately disposed on the lawnmower vehicle 10.

  The lawnmower vehicle 10 is equipped with a control system 58 shown in FIG. 2, and the control system 58 includes the left and right drive motors 22 and 24, the three deck motors 46, and a left and right lever as a plurality of operating element sensors. Sensors 60 and 62, ECU 50 and motor controllers 52, 54 and 56, which are a plurality of controllers, a battery 36, and an indicator 64 are included. The battery 36 supplies power to the drive motors 22 and 24 and the deck motors 46.

  A positive line and a negative line connected to the positive side and the negative side of the battery 36 are respectively connected to the positive side and the negative side of an inverter (not shown) which is a driver for right and left driving wheels via a relay. It is connected. The right and left inverters are provided as part of the right drive motor controller 56 and the left drive motor controller 54 connected to the battery 36, respectively. That is, each drive motor controller 54, 56 includes an inverter and an inverter control circuit (not shown) having a CPU for controlling the inverter. Each inverter is connected to a corresponding drive motor 22, 24 and drives the drive motor 22, 24.

  Each inverter includes a three-phase arm in which two switching elements such as transistors and IGBTs are connected in series. Each inverter control circuit controls the switching of each switching element in response to the input of a rotational speed command signal, which is a command signal for the number of rotations of the motor per unit time, from the ECU 50, and the corresponding drive. The motors 22 and 24 can be driven at a rotational speed corresponding to the rotational speed command signal. That is, the ECU 50 transmits a control signal to the drive motor controllers 54 and 56. The ECU 50 includes a control circuit unit having a storage unit such as a CPU and a memory.

  As shown in FIG. 1, a left and right lever type operation element 44 having two left and right operation levers 40 and 42 provided on both sides in the left and right direction which is the width direction with respect to the seat of the lawn mower vehicle 10 is provided. The control system 58 in FIG. 2 is provided with left and right lever sensors 60 and 62 for detecting the operation amount and the operation direction of the left and right lever type operation element 44, and detection signals from the left and right lever sensors 60 and 62 are sent to the ECU 50. Have been entered. In FIG. 2, each lever sensor 60, 62 includes a main sensor and a sub sensor, and in the corresponding lever sensor 60, 62, when the difference between the main sensor and the sub sensor is equal to or greater than a preset threshold value, The ECU 50 can also recognize that an abnormality has occurred in the sensor value and control the vehicle speed to be reduced or stopped. In addition, when the ECU 50 recognizes that an abnormality has occurred in the vehicle, the indicator 64 can display the occurrence of the abnormality or notify the user with a lighting unit or the like. The indicator 64 can also have a function of displaying that the battery 36 is being charged by an external AC power source. When a steering operation element is used as the turning instruction tool, a detection signal of a steering sensor that detects an operation amount and an operation direction of the steering operation element is input to the ECU 50. When an accelerator pedal is used as an acceleration indicator that is an operator, a detection signal of an accelerator sensor that detects an operation amount of the accelerator pedal is input to the ECU 50.

  The ECU 50 has a drive control unit 66 as shown in FIG. The drive control unit 66 drives the left and right to drive the vehicle at a speed corresponding to the corresponding direction according to the detection signals of the left and right lever sensors 60 and 62 (FIG. 2) (or the steering sensor and the accelerator sensor). The target rotational speed of the motors 22 and 24 is calculated. The drive control unit 66 transmits the target rotational speeds of the drive motors 22 and 24 to the corresponding drive motor controllers 54 and 56, and the drive motor controllers 54 and 56 receive the corresponding drive motors via the corresponding inverters. 22 and 24 are controlled. In this way, the drive control unit 66 controls the operation of the left and right drive motors 22 and 24 via the drive motor controllers 54 and 56 in accordance with signals from the lever sensors 60 and 62 that are at least one operating element sensor. To do. Note that the ECU 50 controls the left and right drive motors 22 and 24 in order to drive the vehicle at a speed corresponding to the corresponding direction according to the detection signals of the left and right lever sensors 60 and 62 (or the steering sensor and the accelerator sensor). The target torque may be calculated by the target torque calculation unit. In this case, the ECU 50 transmits the target torque of the drive motors 22 and 24 corresponding to the drive motor controllers 54 and 56, and controls the operation of the drive motors 22 and 24. In the present application, “rotational speed” includes both the general meaning of the rotational speed and the meaning of the number of rotations per unit time (the same applies hereinafter).

  2, the battery 36 is connected to the ECU 50 via a DC / DC converter 70 and a switch connection relay (not shown) connected to a key switch 68 that is a main switch. The voltage is stepped down by the DC / DC converter 70 and supplied to the ECU 50. For example, when the voltage of the battery 36 is 48V, it is stepped down to 12V by the DC / DC converter 70 and supplied to the ECU 50, and the ECU 50 is operated, that is, turned on. Further, a self holding relay 72 is provided between the battery 36 and the ECU 50 and connected in parallel with the key switch 68 and switched on and off by a control signal from the ECU 50. The key switch 68 is turned on (or turned off) when a key is inserted and turned by the user, and transmits a signal indicating that the key is turned on (or turned off) to the ECU 50. For example, when the key switch is turned on, electric power is supplied from the battery 36 to the ECU 50 via the DC / DC converter 70 and the switch connection relay, and the ECU 50 turns on the self-holding relay 72. Thus, the self-holding relay 72 is connected between the battery 36 and the ECU 50 so that the electric power of the battery 36 can be supplied to the ECU 50. On the other hand, when the key switch 68 is switched from on to off, the switch connection relay is cut off, but the self-holding relay 72 is turned on only when all of the drive motors 22, 24 and the deck motors 46 are stopped. From the battery 36 to the ECU 50, and the power supply from the battery 36 to the ECU 50 is cut off. Therefore, as long as any one of the drive motors 22 and 24 and the deck motors 46 is being driven, the electric power of the ECU 50 is not immediately cut off even if the key switch 68 is accidentally turned off. Of course, it is also possible to supply electric power from the battery 36 to the ECU 50 via the DC / DC converter 70 and the key switch 68 without including the self-holding relay 72.

  As shown in FIG. 4 described later, the ECU 50 includes a mower relation control unit 74. The mower-related control unit 74 sets the three deck motors 46 in advance when the deck switch 47 (FIG. 2) is turned on and “economy mode” is selected by a mode switch 76 described later. A control signal is transmitted to each deck motor controller 52 so as to rotate at the high-efficiency constant rotation speed. The mower relation control unit 74 controls the operation of each deck motor 46 via the corresponding deck motor controller 52.

  As shown in FIG. 2, the positive and negative wires connected to the positive and negative sides of the battery 36 are respectively connected to three deck inverters (not shown) provided in the three deck motor controllers 52 via relays. To the positive electrode side and the negative electrode side. Each deck inverter is connected to a corresponding deck motor 46 and drives each deck motor 46. For example, each deck motor 46 can be a three-phase electric motor or the like similar to each drive motor 22, 24.

  Each deck inverter can be configured in the same manner as the inverter included in each of the drive motor controllers 54 and 56 described above. The control circuit of each deck motor controller 52 controls switching of each switching element in response to a rotational speed command signal corresponding to the target rotational speed of the deck motor 46 from the ECU 50, and the corresponding deck motor 46 is controlled. Can be driven at a corresponding rotational speed.

  The control system 58 also includes left and right electromagnetic brakes 78 corresponding to the wheels 18 and 20 in order to brake the wheels 18 and 20 (FIG. 1). Further, a brake pedal (not shown) is provided on the upper surface side of the main frame 12, and a detection signal of a brake sensor that detects an operation amount of the brake pedal is input to the ECU 50. In accordance with a signal from the brake sensor, the ECU 50 turns off or on a brake relay connected between each electromagnetic brake 78 and the battery 36 to thereby provide an electromagnetic brake provided in the periphery of the axle of each wheel 18, 20. 78 is turned on or off, and braking is executed or released.

  FIG. 3 is a block diagram illustrating a connection configuration of the ECU, the drive motor controller, and the drive motor in the present embodiment. FIG. 4 is a block diagram showing the configuration of the ECU in FIG. 3 in detail. In FIG. 3, the plurality of lever sensors 60 and 62 (FIG. 2) are collectively shown as an operation element sensor 80.

  As shown in FIG. 3, the detection signal of the operation element sensor 80 and the signals indicating the on / off states of the deck switch 47 and the key switch 68 are input to the ECU 50. Further, as shown in FIG. 4, rotation angle sensors 82 and 84 for detecting the rotation angles of the drive motors 22 and 24 and the deck motors 46 are provided. The detection signals of the rotation angle sensors 82 and 84 are input to the corresponding motor controllers (the drive motor controllers 54 and 56 or the deck motor controller 52). Each motor controller 52, 54, 56 includes a calculation unit that calculates the rotation speed of the drive motor 22, 24 or the deck motor 46 from the detected value of the rotation angle. A corresponding rotation speed detection unit is configured by the calculation unit of each motor controller 52, 54, 56 and the corresponding rotation angle sensor. It is also possible to provide a rotational speed sensor as a rotational speed detection unit for detecting the rotational speeds of the drive motors 22 and 24 and the deck motors 46, and to input the detection signals to the corresponding motor controllers 54, 56 and 52. it can. Note that the rotation angle sensor 84 that detects the rotation angle of each deck motor 46 may be omitted.

  Thus, the lawnmower vehicle 10 is a drive motor 22, 24 that drives the wheels 18, 20 as at least one drive wheel, a deck motor 46 that drives at least one lawnmower 32, and at least one controller. The ECU 50 and a plurality of motor controllers 52, 54, and 56 and left and right lever sensors 60 and 62 that are at least one operating element sensor that detects the operation amount of the left and right lever operating element 44 that is at least one operating element are provided.

  As shown in FIG. 4, the ECU includes a vehicle speed calculation unit 86, a drive control unit 66, and a mower relation control unit 74. The vehicle speed calculation unit 86 calculates the vehicle speed of the lawnmower vehicle 10 (FIG. 1). For example, the vehicle speed calculation unit 86 calculates the actual vehicle speed according to the detection signals of the rotation speeds of the drive motors 22 and 24 from the rotation speed detection units such as the drive motor controllers 54 and 56. Further, the vehicle speed calculation unit 86 calculates the target vehicle speed of the lawnmower vehicle 10 in accordance with signals from the lever sensors 60 and 62. Then, when the speed difference between the target vehicle speed and the actual vehicle speed is equal to or less than a preset vehicle speed calculation threshold speed, the vehicle speed calculation unit 86 sets the target vehicle speed or the actual vehicle speed in accordance with an instruction of a mode switch 76 described later in a lawn mowing running cooperative mode. Is calculated as a vehicle speed for controlling the rotational speed of the deck motor 46 when the “nice mode” is executed, and when the speed difference between the target vehicle speed and the actual vehicle speed exceeds the vehicle speed calculation threshold speed, The actual vehicle speed is calculated as a vehicle speed for controlling the rotation speed of the deck motor 46 when the “nice mode” is executed.

  It should be noted that a current sensor for detecting a current of a part or all of each phase connecting each drive motor 22, 24 and each deck motor 46 and the corresponding inverter is provided, and the detection signal of the current sensor corresponds. It can also be input to the motor controllers 54, 56, 52. Each function of the ECU 50 can be realized by software by executing a stored program or the like, but a part or all of the functions can be realized by hardware.

  According to such a lawnmower vehicle 10, the operation levers 40 and 42 of the left and right lever type operation element 44 are swung around the horizontal axis in the vehicle width direction, thereby accelerating the vehicle forward or backward. Can be made. By tilting the left and right control levers 40, 42 forward, the vehicle can be advanced by the forward rotation of the left and right drive motors 22, 24, and by tilting the left and right control levers 40, 42 rearward, The vehicle can be moved backward by the reverse rotation of the left and right drive motors 22, 24. By changing the amount of tilting of the left and right control levers 40, 42, a difference in rotational speed between the left and right wheels 18, 20 can be produced, and the vehicle can be turned.

  In particular, the control system 58 of the lawnmower vehicle 10 according to the present embodiment allows the mower of the deck motor 46 to respond to an increase in the vehicle speed of the lawnmower vehicle 10 in at least a predetermined vehicle speed region of the lawnmower vehicle 10 by establishing a predetermined condition. The relation between the vehicle speed and the mower-related target rotational speed is set in the “turf mowing driving cooperative relation” in which the related target rotational speed increases, and the deck motor is set at the mower-related target rotational speed based on the above “mowing lawn driving cooperative relation”. Each deck motor 46 is controlled to execute a “nice mode”, which is a lawn mowing running cooperative mode for driving 46.

  More specifically, a mode switch 76 shown in FIG. 2 and FIG. 4 is provided at a position that can be operated by the user, for example, on an operation panel provided at the periphery of the seat such as the front side or the left or right side of the seat. FIG. 5 is a diagram showing an example of the mode switch 76 shown in FIG. As shown in FIG. 5, the mode switch 76 has a knob 88 that can be twisted with a finger, and is separated from a nice mode (Nice position in FIG. 5) that is a lawnmower running cooperative mode by a user operation. Can be switched to the economy mode (Eco position in FIG. 5), and the switching is instructed by the user's operation, and an instruction signal indicating the instructed mode is sent to the ECU 50 (FIG. 2 etc.) Output. In the following description, the same or corresponding elements as those shown in FIGS.

  The mower-related control unit 74 (FIG. 4) of the ECU 50 assumes that the above predetermined condition is satisfied when the mode switch 76 switches to the nice mode, and the relationship between the vehicle speed of each deck motor 46 and the mower-related target rotational speed. Is set to the above-mentioned “mowing lawn mowing cooperative relationship”. The mower relation control unit 74 executes the “nice mode” in which the deck motor 46 is driven at the mower relation target rotation speed based on the lawn mowing running cooperative relation and the vehicle speed calculated by the vehicle speed calculation unit 86. Thus, each deck motor 46 is controlled. That is, when the mower relation control unit 74 is switched to the nice mode, the mower relation control unit 74 transmits a command signal representing the mower relation target rotation speed based on the lawn mowing running cooperative relation and the vehicle speed to each deck motor controller 52, and Each deck motor 46 is controlled via the deck motor controller 52. That is, the ECU 50 selects the control logic of the selected mode in accordance with the instruction signal from the mode switch 76.

  When the nice mode is instructed by the mode switch 76, the mower relation control unit 74 is preset based on the lawn mowing driving cooperative relation stored in the storage unit with data such as a map. The mower-related target rotation speed is calculated according to the vehicle speed calculated by the vehicle speed calculation unit 86.

FIG. 6 is a diagram illustrating an example of the relationship between the vehicle speed and the peripheral speed of the deck blade corresponding to the lawn mowing traveling cooperative relationship set in the nice mode in the present embodiment. The peripheral speed of the deck blade is determined according to the length of the deck blade provided in the vehicle, that is, the length from the rotation center to the tip of each cutting blade element, and the rotation speed of the deck motor 46. That is, the peripheral speed Bv (m / s) at the tip of each cutting blade element, which is the peripheral speed of the deck blade, is the rotational speed DMn (min ⁻¹ ), which is the rotational speed of the deck motor 46, and the deck. Using the blade length VL (m), the following equation is obtained.

Bv = (DMn × π × VL) / 60 (1)

  In addition, the present inventor has defined the following coefficient called “Nice coefficient” as a coefficient representing the cleanness of the cut grass, that is, the good lawn condition. The nice coefficient Nk is defined by the following equation using the peripheral speed Bv (m / s) of each cutting blade element, where the vehicle speed is CV (m / s).

Nk = Bv / CV (2)

  Therefore, the nice coefficient Nk increases as the vehicle speed CV decreases, increases as the peripheral speed Bv of each cutting blade element increases, and the nice coefficient Nk increases, that is, if the slope of the solid line X in FIG. A lawn state that is high in efficiency, that is, a good lawn can be obtained by a short mowing operation. Further, since the peripheral speed of the deck blade is low when the vehicle speed is low, energy consumption can be reduced compared to the case where the peripheral speed of the deck blade is increased regardless of the vehicle speed.

  For example, the relationship between the vehicle speed and the peripheral speed of the deck blade is defined in the nice mode as shown by the solid line X in FIG. 6, and the relationship between the vehicle speed and the rotation speed of the deck motor 46 is based on this relationship. Set “Moving lawn mowing cooperative relationship”. That is, since the length VL of the deck blade is uniquely determined in the vehicle, the rotation speed of the deck motor 46 is uniquely determined corresponding to the peripheral speed Bv of the deck blade. That is, the vertical axis in FIG. 6 can be replaced with the rotation speed of the deck motor 46.

  In this case, as is apparent from FIG. 6, when the vehicle speed is less than a preset threshold speed a (m / s), the rotational speed of the deck motor 46 is set to a constant rotational speed corresponding to the peripheral speed b of the deck blade in FIG. And Further, when the vehicle speed is equal to or higher than the threshold speed a (m / s), the rotation speed of the deck motor 46 is linearly increased in accordance with the increase in the vehicle speed. The vehicle speed a or higher in FIG. 6 is the application range of the nice coefficient Nk (range α in FIG. 6). That is, the ratio of the rotational speed of the deck motor 46 to the vehicle speed at the vehicle speed a or higher is preset according to a predetermined nice coefficient Nk. Then, the ECU 50 stores, in the storage unit, a “lawn mowing driving cooperative relationship” that represents the relationship between the vehicle speed and the rotation speed of the deck motor 46 in accordance with the relationship between the vehicle speed indicated by the solid line X in FIG. 6 and the peripheral speed of the deck blade. I remember it.

  When the mower-related control unit 74 of the ECU 50 is switched to the nice mode, the mower-related target rotational speed of the deck motor 46 is set in accordance with the “mowing lawn mowing cooperative relationship”, and the set mower-related target rotational speed is set. Thus, the deck motor 46 is controlled to be driven. For this reason, when the vehicle speed is less than a, each deck motor 46 rotates at a constant rotation speed, but when the vehicle speed is a or more, the rotation speed of each deck motor 46 increases as the vehicle speed increases. It should be noted that the relationship between the vehicle speed and the peripheral speed of the deck blade is linearly according to the nice coefficient as the vehicle speed increases from 0 when the vehicle is moving forward, as indicated by a broken line β in FIG. It can also be increased. Note that the threshold speed a and the constant rotational speed b defined in FIG. 6 can be determined in advance by performance specifications by a vehicle manufacturer, a parts manufacturer, or the like. The nice coefficient Nk can be set in advance by a vehicle manufacturer, a parts manufacturer, or the like conducting a test.

  Further, FIG. 6 illustrates the case where the relationship between the vehicle speed, the peripheral speed of the deck blade and the rotation speed of the deck motor 46 is defined according to the nice coefficient Nk, but the peripheral speed of the deck blade is increased by another coefficient as the vehicle speed increases. In addition, the rotational speed of the deck motor 46 can be increased linearly. Further, the peripheral speed of the deck blade and the rotational speed of the deck motor 46 can be increased in a curved manner as the vehicle speed increases. In any case, in the lawn mowing driving cooperative relationship set in the nice mode, the relationship between the mower-related target rotational speed of the deck motor 46 and the vehicle speed is set at least in a predetermined speed range with respect to the vehicle speed according to the increase in the vehicle speed. Set the target rotation speed to increase.

  In the above description, the vehicle speed calculation unit 86 calculates the target vehicle speed and the actual vehicle speed, but may be configured to always calculate only one of the target vehicle speed and the actual vehicle speed as the vehicle speed.

  On the other hand, when the mode switch 76 of FIG. 5 is switched to the economy mode and the deck switch 47 is turned on, the drive control unit 66 included in the ECU 50 causes the maximum allowable target vehicle speed to be permitted. The speed is changed to the economy maximum speed set in advance so as to be lower than when the mode is switched to the nice mode, that is, the speed is reduced, and the rotational speed of each of the drive motors 22 and 24 is changed to the maximum speed of the vehicle. Further, the mower-related control unit 74 controls each deck motor 46 so as to rotate at a preset high-efficiency constant speed.

  FIG. 7 is a diagram for explaining the rotation speed corresponding to the high-efficiency constant speed of the deck motor 46 set in the economy mode in the present embodiment. FIG. 7 shows the rotational speed that is the conventional mower-related target rotational speed set in the operation mode that is set in one example of the conventional lawnmower vehicle by NL. Further, in FIG. 7, the contour lines indicate the plurality of efficiencies of the deck motor 46, and indicate that the highest efficiency region has the region where the efficiency is highest in the portion painted in black. Thus, the efficiency of the deck motor 46 varies with the rotational speed and torque. In a conventional lawnmower vehicle, the number of revolutions of the deck motor 46 may be set in a portion deviating from the maximum efficiency region as indicated by NL in FIG.

  On the other hand, in this embodiment, when the economy mode is instructed by the mode switch 76, the mower relation control unit 74 is set to a high efficiency constant speed (NX in FIG. 7) that may enter the maximum efficiency region. Set the target rotational speed for mowers. When there is one maximum efficiency point at which the motor efficiency is maximum in the maximum efficiency region, the high efficiency constant speed may be the speed of this maximum efficiency point. In addition, the drive control unit 66 uses the above equations (1) and (2) to obtain a nice coefficient Nk that is set in advance, so that the vehicle speed when the mower-related target rotational speed becomes a highly efficient constant speed is obtained. And the calculated vehicle speed is set as the maximum economy speed that is the maximum permitted speed. For this reason, the maximum rotational speed at which the rotational speeds of the drive motors 22 and 24 are permitted is lower than that in the nice mode in both the straight traveling and the turning traveling, and the vehicle is permitted as compared with the nice mode. Maximum speed is reduced.

  According to such a lawnmower vehicle 10, it is possible to realize the lawnmower vehicle 10 that can obtain a good lawn state by efficient work. That is, the rotation speed of the deck motor 46 increases in accordance with the increase in the vehicle speed in at least a predetermined vehicle speed region of the lawnmower vehicle 10 when the predetermined condition is satisfied when the nice mode is selected by switching the mode switch 76 of the user. For this reason, even when the vehicle speed is high, a desired good turf state can be realized in a short working time, and the rotational speed of the deck motor 46 becomes low at a low vehicle speed, so that energy saving can be achieved. In addition, the lawnmower vehicle 10 that can obtain a good turf state through efficient work can be realized. As a result, the degree of freedom in selecting the vehicle performance by the user increases, and the functionality of the lawnmower vehicle 10 becomes rich. For example, when the user wants to finish the work quickly before it rains, the user can finish the work quickly by selecting the nice mode, and the cleanliness of the turf can be secured. Conventionally, there are cases where the user adjusts the vehicle speed while looking at the turf situation after cutting, but by leaving this function to the vehicle, the burden on the user can be reduced.

  Further, when the user operates the mode switch 76 to switch to the economy mode and when the deck switch 47 is turned on, the rotation speed of the deck motor 46 becomes a high efficiency constant speed (NX in FIG. 7). It is maintained and the maximum vehicle speed is changed to a lower economy maximum speed than when the nice mode is selected. For this reason, energy saving can be achieved by permitting traveling at a maximum speed lower than that in the nice mode. Moreover, a desired good turf state can be obtained by an efficient work.

  Next, FIG. 8 is a diagram illustrating a first example of another example of the mode switch 76. In the case of the lawnmower vehicle of the present embodiment using the mode switch 76 of another example of FIG. 8, in the above-described embodiments of FIGS. 1 to 7, the mode switch 76 is different from the nice mode and the economy mode by the user's operation. It is possible to switch between the three operation modes with the user mode (User position in FIG. 7) which is the operation mode. Then, the mode switch 76 instructs the switching by the user's operation, and outputs an instruction signal indicating the instructed mode to the ECU 50 (see FIG. 2 and the like). In the following description, the same or corresponding elements as those shown in FIGS. 1 to 5 are given the same reference numerals.

  When the mode switch 76 in FIG. 8 is used to switch to the user mode and the deck switch 47 is turned on, the mower relation control unit 74 sets the above-described high efficiency constant speed (in FIG. 7). NX) controls the operation of the deck motor 46 so as to maintain the mower-related target rotational speed. This high-efficiency constant speed is the same as that described with reference to FIG.

  In the user mode, unlike the economy mode, the permitted maximum rotational speed of the drive motors 22 and 24 is not lower than that in the nice mode, and the permitted maximum speed of the vehicle compared to the nice mode. Will not drop. For this reason, when the user operates the mode switch 76 to switch to the user mode, there is a possibility that the grass quality after the same work compared to the economy mode described above may be lower than the economy mode. Since the maximum speed of the vehicle is higher than that in the economy mode, it becomes easier to travel more comfortably according to the user's driving intention, and the degree of freedom of driving is increased. Also, in the user mode, as in the economy mode, the deck motor 46 can be rotated at a high efficiency and constant speed, so that energy saving can be achieved. For example, it is possible to provide comfortable travel while saving energy to a user who enjoys lawn mowing. Other configurations and operations are the same as those of the above-described embodiments of FIGS.

  Note that the mode switch 76 may be configured as shown in FIG. For example, in FIG. 9, it is possible to instruct switching between four operation modes of a normal mode (Normal position in FIG. 9), a nice mode, an economy mode, and a user mode. In this case, when the mode is switched to the normal mode and the deck switch 47 is turned on, the speed of each deck motor 46 is set to a high-efficiency constant speed which is the speed in the economy mode and the user mode (see FIG. 7). NX) at a normally constant speed (NL in FIG. 7). For this reason, there is a possibility that the energy saving effect may be reduced in the economy mode and the user mode, but the work can be completed earlier by increasing the speed of the deck motor 46. The mode switch 76 of FIG. 9 can be configured to enable switching between any two or three operation modes, and the ECU 50 is configured to switch the operation mode in accordance with the switching. You can also For example, the lawnmower vehicle can be configured to be switchable between an economy mode and a normal mode or a user mode.

  Further, the mode instruction device is not limited to the mode switch 76 (FIG. 5 and the like) as described above. For example, as shown in FIG. 10, the mode instruction device has push buttons 90 for a nice mode, an economy mode, and a user mode. A mode setting device 92 can also be employed. The mode setting device 92 is also provided on the operation panel, for example. In the example of FIG. 10, the mechanism of the push button 90 can be coordinated so that any one of the nice mode, the economy mode, and the user mode is always pressed. Further, assuming that the normal mode is instructed when all the push buttons 90 are not pressed, the ECU 50 can perform control when the mode is switched to the normal mode. Note that any one or two buttons in FIG. 10 may be omitted, and the lawnmower vehicle can be switched between two or three operation modes. Although not shown in the drawings, any one of the above modes may be instructed by an operation position of a mode switching lever supported by the vehicle so as to be swingable around the periphery of the seat.

  In the above description, the nice mode is executed assuming that the predetermined condition is satisfied when the mode switch 76 switches to the nice mode. However, the present invention is not limited to this. For example, the predetermined condition is satisfied on the condition that the key switch 68 is turned on, that is, the ECU 50 can be controlled to always execute the nice mode when the vehicle is started. In the above description, a case has been described in which a plurality of controllers including the ECU 50 and the drive motor controllers 54 and 56 and the deck motor controllers 52 are provided as controllers. However, in the motor control system and lawn mower vehicle, the ECU 50 and the drive motor controllers are provided. 54, 56 or each deck motor controller 52 may be integrated by one controller, or the ECU 50, each drive motor controller 54, 56 and each deck motor controller 52 may be integrated by one controller. it can. Further, the case where the drive motors 22 and 24 and the deck motor 46 are electric motors has been described above, but the present invention can also be applied to the case where either one or both of the motors are constituted by hydraulic motors.

  DESCRIPTION OF SYMBOLS 10 Lawn mower vehicle, 12 Main frame, 14 Left caster wheel, 16 Right caster wheel, 18 Left wheel, 20 Right wheel, 22 Left drive motor, 24 Right drive motor, 26, 28 Power generation unit, 30 Housing, 32 Lawn mower (More), 34 more deck, 36 battery, 40 left operation lever, 42 right operation lever, 44 left and right lever type operator, 46 deck motor, 47 deck switch, 50 ECU, 58 control system, 60 left lever sensor, 62 right lever Sensor, 66 Drive control unit, 74 More control unit, 76 mode switch, 80 operation sensor, 82, 84 rotation angle sensor, 86 vehicle speed calculation unit.

Claims (10)

A lawnmower vehicle comprising a drive wheel motor that drives at least one drive wheel, a mower-related motor that drives at least one lawnmower, and at least one controller,
The at least one controller comprises:
With the establishment of a predetermined condition set in advance, the mower-related target rotation speed of the mower-related motor increases in accordance with an increase in the vehicle speed of the lawnmower vehicle at least in a predetermined vehicle speed region of the lawnmower vehicle. A relationship between the vehicle speed and the mower-related target rotational speed is set, and a lawn mowing travel cooperative mode in which the mower-related motor is driven at the mower-related target rotational speed based on the lawn mowing travel cooperative relation is executed. A lawnmower vehicle that controls the mower-related motor. The lawnmower vehicle according to claim 1,
At least one operator sensor for detecting an operation amount of at least one operator;
A mode instruction device for instructing switching between the lawn mowing driving cooperation mode and at least one other operation mode by a user operation;
The at least one controller comprises:
A drive controller for controlling the operation of the drive wheel motor in response to a signal from the at least one operator sensor;
A vehicle speed calculation unit for calculating the vehicle speed of the lawnmower vehicle;
A mower-related control unit for controlling the operation of the mower-related motor,
When the mode instruction device is switched to the lawn mowing running cooperative mode, the mower relation control unit determines that the predetermined condition is satisfied, and determines that the relationship between the vehicle speed and the mower relation target rotation speed is the lawn mowing running. A lawnmower vehicle that is set to a cooperative relationship and controls the mower-related motor so as to execute the lawnmower traveling cooperative mode. The lawnmower vehicle according to claim 2,
The lawn mowing driving cooperative relationship is such that the mower-related target rotational speed of the mower-related motor is kept constant when the speed of the lawn mower vehicle is less than a threshold speed, and the speed of the lawn mower vehicle increases when the vehicle speed is equal to or higher than the threshold speed. A lawnmower vehicle characterized in that the mower-related target rotational speed of the mower-related motor increases in response to the motor. The lawnmower vehicle according to claim 2,
Comprising a mower start switch for instructing start of the mower-related motor by a user operation;
The mode instructing device instructs the switching between the lawn mowing running cooperation mode and the economy mode by a user operation,
The vehicle speed calculation unit calculates a target vehicle speed of the lawnmower vehicle according to a signal from the at least one operator sensor,
When the mode indicating device is switched to the economy mode and the mower activation switch is turned on, the drive control unit sets the permitted maximum speed of the target vehicle speed to the lawn mowing driving coordination. Change to the economy maximum speed that is lower than when switched to the mode, and control the rotational speed of the drive wheel motor, and the mower-related control unit is configured to rotate at a preset constant speed. A lawnmower vehicle that controls the mower-related motor. The lawnmower vehicle according to claim 2,
Comprising a mower start switch for instructing start of the mower-related motor by a user operation;
The mode instruction device instructs the switching between the lawn mowing running cooperative mode and the user mode by a user operation,
When the mode is switched to the user mode by the input of an instruction signal from the mode instruction device and the mower activation switch is turned on, the mower relation control unit is set at a predetermined constant speed. A lawnmower vehicle, wherein the mower-related motor is controlled to rotate. The lawnmower vehicle according to claim 2,
Comprising a mower start switch for instructing start of the mower-related motor by a user operation;
The mode instructing device instructs the switching between the lawn mowing driving cooperation mode, the economy mode, and the user mode by a user operation,
The vehicle speed calculation unit calculates a target vehicle speed of the lawnmower vehicle according to a signal from the at least one operator sensor,
When the mode indicating device is switched to the economy mode and the mower activation switch is turned on, the drive control unit sets the permitted maximum speed of the target vehicle speed to the lawn mowing driving coordination. Change to the economy maximum speed that is lower than when switched to the mode, and control the rotational speed of the drive wheel motor, and the mower-related control unit is configured to rotate at a preset constant speed. Controlling the mower-related motor,
When the mode indicating device is switched to the user mode and the mower activation switch is turned on, the mower relation control unit rotates the mower so as to rotate at a predetermined constant speed. Lawn mowing vehicle characterized by controlling a related motor. The lawnmower vehicle according to claim 2,
The lawn mowing vehicle, wherein the vehicle speed calculation unit calculates the vehicle speed according to a signal from the at least one operator sensor. The lawnmower vehicle according to claim 2,
A rotation speed detector for detecting the rotation speed of the drive wheel motor;
The lawn mowing vehicle, wherein the vehicle speed calculation unit calculates the vehicle speed according to a detection signal from the rotation speed detection unit. The lawnmower vehicle according to claim 2,
A rotation speed detector for detecting the rotation speed of the drive wheel motor;
The vehicle speed calculation unit calculates a target vehicle speed of the lawnmower vehicle according to a signal from the at least one operator sensor, and calculates an actual vehicle speed of the lawn mower vehicle according to a detection signal from the rotational speed detection unit. When the speed difference between the target vehicle speed and the actual vehicle speed is equal to or lower than a vehicle speed calculation threshold speed, the target vehicle speed or the actual vehicle speed is calculated as the vehicle speed, and the speed difference between the target vehicle speed and the actual vehicle speed is When the vehicle speed calculation threshold speed is exceeded, the actual vehicle speed is calculated as the vehicle speed. A lawnmower vehicle comprising a drive wheel motor that drives at least one drive wheel, a mower-related motor that drives at least one lawnmower, and at least one controller,
At least one operator sensor for detecting an operation amount of at least one operator;
A mode indicating device for instructing switching between the economy mode and at least one other operation mode by a user operation;
A mower start switch for instructing start of the mower-related motor by a user operation,
The at least one controller comprises:
A vehicle speed calculation unit that calculates a target vehicle speed of the lawnmower vehicle according to a signal from the at least one operator sensor;
A drive controller for controlling the operation of the drive wheel motor in response to a signal from the at least one operator sensor;
A mower-related control unit for controlling the operation of the mower-related motor,
When the mode indicating device is switched to the economy mode and the mower activation switch is turned on, the permitted maximum speed of the target vehicle speed of the lawn mower vehicle can be switched to the other operation mode. The motor-related motor is controlled so as to control the rotational speed of the driving wheel motor, and the mower-related control unit rotates at a preset constant speed. Lawn mowing vehicle characterized by controlling

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