JP2016217300A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work vehicle capable of reliably saving fuel without requiring operation of an operator.SOLUTION: A work vehicle comprises: an engine E; a starter switch 102; an accelerator operation tool 106; a rotation sensor 104; a fuel injection valve 105 which changes an amount of fuel injected into the engine E so that a rotation speed N detected by the rotation sensor 104 becomes a target rotation speed set through the accelerator operation tool 106; a speed meter 109; a transmission mechanism 107; a machine control section 100 and an engine controller 101 which calculate a load of the engine E on the basis of the rotation speed N and control the rotation speed N and a traveling speed; and an engine rotation reduction range setting dial 70 to set a reduction range of the rotation speed N. When the engine E is started up with the starter switch 102 operated, the rotation speed N thereof is controlled to a difference calculated by subtracting the reduction range from the target rotation speed by the engine controller 101.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a work vehicle, and more particularly to a work vehicle in which fuel is saved.

  Efforts to reduce the burden on the global environment are urgently needed. For example, work vehicles such as tractors are no exception, and exhaust gas regulations are gradually being tightened around the world. For this reason, by improving fuel efficiency, tractors that suppress fuel consumption and realize low exhaust gas amount are provided one after another.

  On the other hand, the tractor has a wide range of use, and the required output (load) varies greatly depending on the work contents. Therefore, there is a tractor equipped with a fuel-saving mode as a function that uses the property that fuel consumption is reduced by lowering the engine speed when work with a sufficient load on the maximum output is performed. To do.

  Patent Document 1 discloses a sub-transmission unit that switches a plurality of travel sections including work travel and road travel, and an accelerator pedal operation and an engine load by automatic shift control applied to a road travel section by the sub-transmission unit. And a main transmission for shifting gears that shifts in multiple stages at the shift position corresponding to the engine, and the engine control is performed by switching between a standard mode (N) with normal fuel consumption characteristics and a low fuel consumption mode (S) with low fuel consumption characteristics. A work vehicle is disclosed that is configured to be capable of mode switching, and is provided with a mode setting section (M) for each traveling section that determines an engine control mode in response to switching of the traveling section of the sub-transmission section. .

JP 2012-047141 A

  According to the configuration of Patent Document 1, when the vehicle shifts to road running by switching the sub-transmission unit, the engine control mode set separately is applied, and the gear is shifted in multiple stages according to the operation of the accelerator pedal by automatic shift control. Therefore, it is possible to shift to road running in a mode in line with the operator's will without requiring annoying mode switching operation after work traveling, while ensuring arbitrary mode switching by switching operation of the engine control mode. It is supposed to be possible. However, in the work vehicle of the cited document 1, it is necessary to store the fuel consumption mode to be applied to each travel section by separately setting the fuel consumption mode. Therefore, in the work vehicle of the cited document 1, not only the operation for applying the low fuel consumption mode becomes complicated, but also the low fuel consumption mode is not necessarily applied. That is, in the work vehicle of the cited document 1, there is a possibility that the low fuel consumption mode may not be effectively utilized due to troublesome operation, inappropriate settings, and the like.

  Therefore, an object of the present invention is to provide a work vehicle that can reliably save fuel without requiring an operation by an operator.

  In order to solve the above-described problems, the present invention provides an engine, a starting unit that starts the engine, a rotation number setting unit that sets a target rotation number of the engine, and a rotation number detection unit that detects the rotation number of the engine. A rotational speed changing unit that changes a fuel injection amount to the engine so that the rotational speed detected by the rotational speed detecting unit becomes the target rotational speed set by the rotational speed setting unit; A work comprising: a speed detecting unit for detecting; a speed change mechanism for adjusting the traveling speed; and a controller for calculating the engine load based on the rotational speed and controlling the rotational speed and the traveling speed. The vehicle further includes a rotation speed adjustment unit that sets a reduction range of the rotation speed, and when the starter is operated and the engine is started, the control unit is configured to calculate the reduction range from the target rotation speed. Only Characterized in that it is configured to control the rotational speed was made.

  Further, the control unit determines whether or not the rotational speed can be reduced based on the load, and if possible, reduces the rotational speed without changing the traveling speed. The rotational speed changing unit and the speed change mechanism are configured to be controlled.

  Further, the control unit further determines whether or not the rotation speed can be reduced based on the amount of reduction, and if possible, reduces the rotation speed without changing the traveling speed. The rotation speed changing unit and the speed change mechanism are configured to be controlled.

Further, the lowering amount is configured to be adjusted in a range of 100 min ⁻¹ to 800 min ⁻¹ .

Further, the lowering width is configured to be adjusted in increments of 100 min ⁻¹ .

  Furthermore, the said rotation speed adjustment part is further provided with the indicator which shows the said reduced width | variety reduced.

  According to the present invention, an engine, a starting unit for starting the engine, a rotational speed setting unit for setting a target rotational speed of the engine, a rotational speed detection unit for detecting the rotational speed of the engine, and detection of the rotational speed detection unit A rotation speed changing unit that changes the amount of fuel injected into the engine so that the rotation speed to be set becomes a target rotation speed set by the rotation speed setting unit, a speed detection unit that detects a traveling speed, and a gear that adjusts the traveling speed A work vehicle that includes a mechanism and a control unit that calculates the engine speed based on the number of revolutions and controls the number of revolutions and the traveling speed, and further includes a number of revolutions adjusting unit that sets a reduction range of the number of revolutions. When the starting unit is operated and the engine is started, the control unit is configured to control the engine speed to be reduced by the amount of reduction from the target engine speed. Ensure fuel savings It is possible to provide a work vehicle for performing.

  Further, the control unit determines whether or not the rotation speed can be reduced based on the load, and when possible, the rotation speed changing unit and the rotation speed changing unit are configured to reduce the rotation speed without changing the traveling speed. According to the configuration that controls the speed change mechanism, it is possible to provide a work vehicle that saves fuel reliably and as much as possible without requiring an operation by an operator.

  Further, the control unit further determines whether or not the rotational speed can be reduced based on the amount of reduction, and if possible, the rotational speed is reduced so as to reduce the rotational speed without changing the traveling speed. According to the configuration that controls the changing unit and the speed change mechanism, it is possible to provide a work vehicle that reliably saves fuel without requiring an operation by an operator and has workability corresponding to a load.

Furthermore, according to the configuration in which the lowering amount is adjusted in the range of 100 min ⁻¹ to 800 min ⁻¹ , workability according to the load is ensured while fuel is reliably saved without requiring an operation by the operator. A work vehicle having the following can be provided.

Further, according to the configuration in which the lowering width is adjusted in increments of 100 min ⁻¹ , a work vehicle having workability corresponding to the load while reliably saving fuel without requiring an operation by an operator is provided. can do.

  Further, according to the configuration in which the rotation speed adjustment unit further includes an indicator that presents the lowered width, it is possible for the worker to reliably save fuel without requiring an operation by the worker. The work vehicle shown can be provided.

It is a side view which shows the form with which the rotary cultivator as an example of a working device was mounted | worn with the tractor as an example of the working vehicle which concerns on this embodiment. It is the top view in which the outline of the inside of a cabin and its periphery was shown. It is the schematic of an engine rotation fall width setting dial. It is a principal part schematic of an instrument panel. It is a principal part block diagram of the control system of a tractor. It is a flowchart of the control method of a tractor. It is the schematic by which an example of the output characteristic map (engine speed-torque diagram) was shown.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a form in which a rotary cultivator 30 as an example of a work device is mounted on a tractor 10 as an example of a work vehicle according to the present embodiment. In the following, for convenience of explanation, the left side in FIG. 1 which is the traveling direction of the tractor 10 is defined as the front direction, and is orthogonal to the traveling direction and extends to the near side and the far side in FIG. The direction is the left-right direction.

  A tractor 10 illustrated in FIG. 1 includes an engine E, a battery BT, a generator (not shown), a radiator, a cooling fan, an air cleaner, and the like in a bonnet 11. The engine E, the battery BT, the generator, and the radiator are placed on the chassis 12. As the engine E, for example, an electronically controlled common rail diesel engine is used. The common rail is also called a pressure accumulation type. The generator is connected to the output portion of the engine E so as to operate using the engine E as power. The battery BT is connected to the generator. Electricity generated by the generator is stored in the battery BT.

  The tractor 10 includes front wheels 13 and 13 on the left and right sides of the front part corresponding to the traveling direction of the airframe, and includes rear wheels 14 and 14 on the left and right sides of the rear part, respectively. That is, the tractor 10 is supported so that the traveling machine body can travel by the wheels. Fenders 15 and 15 are provided so as to cover the left and right rear wheels 14 and 14 from above and from the inside of the tractor 10, respectively. The tractor 10 may have a configuration in which a crawler is used for the traveling device.

  A dashboard 16 is provided behind the bonnet 11 via an air cut plate (not shown). The dashboard 16 is provided with an instrument panel 40 as a display unit for displaying speed, fuel remaining amount, and the like. A steering column cover 17 is provided adjacent to the rear of the dashboard 16. A steering wheel 18 projects from the upper end of the steering column cover 17.

  A driver's seat 20 is provided behind the steering column cover 17 at a predetermined distance. The driver's seat 20 is disposed between the left and right fenders 15 and 15. The driver's seat 20 and the steering wheel 18 are covered with a cabin 19.

  The tractor 10 is not limited to the configuration having the cabin 19, and may be configured such that ROPS (Roll-Over Protective Structures) protrudes upward from the rear ends of the left and right fenders 15, 15. .

  A fuel tank 21 for supplying fuel to the engine E is provided below the cabin 19. The position of the fuel tank 21 is not limited, and may be, for example, the side surface of the cabin 19 or the rear of the driver seat 20. A fuel supply path (not shown) from the fuel tank 21 to the engine E includes a fuel pump, a common rail, and a plurality of cylinders included in the engine E through respective fuel injection valves of a plurality of injectors connected to the common rail. Connected to each. The fuel pump for supplying fuel is configured to pump the fuel in the fuel tank 21 to the common rail. The common rail is configured to store high-pressure fuel. The electromagnetic opening / closing control type fuel injection valve is configured to be opened / closed so that high-pressure fuel in the common rail is injected from the injector into each cylinder of the engine E.

  Below the driver's seat 20, a transmission case TM having a transmission as a transmission mechanism (not shown) that changes the traveling speed of the tractor 10 continuously, for example, is disposed. The transmission case TM is fixed to the rear part of the chassis 12. The transmission has a function of transmitting the power of the engine E to the rear wheels 14 and 14. The tractor 10 may be configured so that the power of the engine E is transmitted to the front wheels 13 and 13.

  On the rear upper surface of the transmission case TM, for example, a hydraulic working device lifting mechanism 22 for lifting and lowering the rotary tiller 30 mounted as a working device is attached. The working device lifting mechanism 22 is not limited to a hydraulic type, and may be a mechanical type using a gear, for example, as long as the working device can be raised and lowered.

  The rotary tiller 30 is connected to the rear of the transmission case TM of the tractor 10 via a three-point link mechanism including a pair of left and right lower links 23 and 23 and a top link 24. The front end sides of the left and right lower links 23 are connected to the left and right side surfaces of the rear portion of the transmission case TM so as to be rotatable. The front end side of the top link 24 is rotatably connected to the rear part of the work device lifting mechanism 22. A PTO (Power Take-Off) shaft 25 for transmitting the driving force of the engine E is linked to the engine E and protrudes rearward from the rear surface of the transmission case TM.

  The work device lifting mechanism 22 includes a pair of left and right lift arms 26 and 26 that are rotated by a lifting hydraulic cylinder (not shown). The left and right lift arms 26 and 26 are connected to the left and right lower links 23 and 23 via left and right lift rods 27 and 27, respectively. Each of the left and right lift arms 26 and 26 is configured such that the rotary tiller 30 moves up and down via the left and right lift rods 27 and 27 and the left and right lower links 23 and 23, respectively, by rotating. .

  Next, the structure of the driver's seat 20 and its surroundings will be described in detail. FIG. 2 is a plan view schematically showing the interior of the cabin 19 (see FIG. 1) and its periphery. As described above, the dashboard 16 is provided with the instrument panel 40, and the steering column cover 17 is provided with the substantially round steering 18 in a plan view.

  On the right side of the steering column cover 17, there is provided an accelerator lever 50 for setting and holding the output rotational speed (rotational speed) of the engine E. On the left side of the steering column cover 17, a reverser lever 51 (forward / reverse switching lever) for switching the traveling direction of the tractor 10 between forward and reverse is provided. On the lower right side of the steering column cover 17, left and right brake pedals 52, 52 for braking the tractor 10 are provided. On the lower left side of the steering column cover 17, a clutch pedal 53 for operating a main clutch for interrupting power transmission from the engine E is provided.

  The entire upper surface of the floor 54 in front of the driver's seat 20 is substantially flat. An accelerator pedal 55 for controlling the rotational speed of the engine E is provided on the floor 54 on the right side of the steering column cover 17.

  On both the left and right sides of the driver's seat 20, armrests 56 are provided for an operator sitting on the driver's seat 20 to place his arms and elbows. The position of the armrest 56 is configured to be adjustable up and down and up and down. A PTO speed change lever 57 that is connected to a PTO speed change mechanism in the transmission case TM (see FIG. 1) and switches the rotational speed of the PTO shaft 25 is provided below the left side of the driver seat 20.

  A main transmission lever 58 that is connected to a transmission mechanism in the transmission case TM (see FIG. 1) and accelerates or decelerates the traveling speed of the tractor 10 is provided in front of the driver seat 20 on the right side. Further, an auxiliary transmission lever 59 is provided adjacent to the main transmission lever 58 for switching the gear ratio of the traveling auxiliary transmission gear mechanism in the transmission case TM (see FIG. 1) to, for example, two stages of high speed and low speed. .

  Next to the auxiliary transmission lever 59, there is provided a PTO drive switch 60 which is connected to a PTO clutch (not shown) and used for driving the PTO. The PTO drive switch 60 is configured to connect and disconnect the PTO clutch and switch the PTO shaft 25 between an operating state and an inactive state. In other words, when the PTO shaft 25 is in an operating state, the PTO clutch is engaged, and the PTO shaft 25 rotates at the rotational speed selected by the PTO speed change lever 57. On the other hand, when the PTO shaft 25 is not in operation, the PTO shaft 25 stops. The PTO drive switch 60 is configured to be activated when it is turned to the left or right while being pressed, and is deactivated when it is pressed once in the activated state. Can be stopped and operability is good.

  In this embodiment, when the clutch pedal 53 is depressed, the rotation of the PTO shaft 25 and the traveling of the tractor 10 are stopped simultaneously. However, a changeover switch (not shown) that switches to an operation that does not stop the rotation of the PTO shaft 25 even when the clutch pedal 53 is depressed may be provided.

  An operation panel 61 is provided on the right side of the armrest 56. The operation panel 61 is configured such that switches for adjusting the operation of the rotary tiller 30 are intensively arranged. The operation panel 61 includes, for example, a depth setting dial and an inclination setting dial.

  Further, on the right side of the operation panel 61, an engine rotation reduction width setting dial 70 is provided as a rotation speed adjustment unit for setting a reduction speed of the rotation speed of the engine E. The engine rotation reduction width setting dial 70 is for carrying out a so-called eco (energy saving) operation mode. The arrangement of the engine rotation reduction width setting dial 70 shown in FIG. 2 is merely an example, and the engine rotation reduction width setting dial 70 may be provided at a location with good operability. For example, it is provided on the dashboard 16. Or may be provided in the instrument panel 40 in the form of a touch panel.

FIG. 3 is a schematic view of the engine rotation reduction width setting dial 70. The engine rotation lowering width setting dial 70 is used to set the lowering range of the rotational speed of the engine E. The engine rotation reduction width setting dial 70 is configured so that, for example, the rotation speed of the engine E is increased (the rotation speed of the engine E is further decreased) by rotation in the clockwise direction. In the example of FIG. 3, the engine rotation reduction width setting dial 70 is provided with a scale 71 in the range of 100 min ⁻¹ to 800 min ⁻¹ . In the tractor 10 according to the present embodiment, the rotation speed reduction range of the engine E is manually adjusted by adjusting the indicator 72 of the engine rotation reduction width setting dial 70 to the position of the scale 71 of the reduction width intended by the operator. It is configured to be.

This is because, for example, the instruction section 72 of the engine rotation reduction width setting dial 70 is set to 800 min ⁻¹ , and the operation of the engine E is performed at 2600 rpm (Revolutions Per Minute: = min ⁻¹ ). If it is determined that there is a margin in the load, the rotational speed of the engine E is reduced to 1800 rpm.

The amount of decrease in the rotational speed of the engine E may be continuously variable in the range of 100 min ⁻¹ to 800 min ⁻¹ . On the other hand, the amount of decrease in the rotational speed of the engine E may be adjusted in increments of 100 min ⁻¹ . It is possible to set the amount of decrease in the number of revolutions of the engine E in a fine and simple manner that can be set in steps of 100 min ⁻¹ . In this case, the engine rotation reduction width setting dial 70 may be configured to stop its rotation every 100 min ⁻¹ and obtain an operation feeling, that is, a click feeling. This configuration is realized by arranging a spring (not shown), a ball (not shown), and the like inside the engine rotation reduction width setting dial 70. According to such a configuration, the reduction range of the rotation speed of the engine E can be reliably set every 100 min ⁻¹ , and the operability is good. In addition, you may be comprised so that switching between a continuous adjustment and the adjustment in a predetermined step can be performed.

On the other hand, the tractor 10 according to the present embodiment is configured to be able to select a method in which the amount of decrease in the rotational speed of the engine E is automatically adjusted. In the example of FIG. 3, the engine rotation reduction width setting dial 70 is provided with an AUTO position 73 separately from the scale 71 in the range of 100 min ⁻¹ to 800 min ⁻¹ . Then, the tractor 10 according to the present embodiment automatically adjusts the instruction portion 72 of the engine rotation reduction width setting dial 70 to the AUTO position 73 so that the reduction amount of the rotation speed of the engine E is not automatically specified by the operator. It is configured to be adjusted. Note that when the engine E is started, the instruction portion 72 of the engine rotation reduction width setting dial 70 may be configured to automatically rotate to the AUTO position 73.

The engine rotation reduction width setting dial 70 may include an indicator that displays the current reduction amount of the engine E rotation speed. In the example of FIG. 3, the engine rotation reduction width indicator lamp 74 as an indicator that presents the current reduction amount of the rotation speed of the engine E by light emission is adjacent to the scale 71 in the range of 100 min ⁻¹ to 800 min ⁻¹ . It is provided with a plurality.

  For example, an LED (Light Emitting Diode) is used for the engine rotation reduction width indicator lamp 74. It is possible to easily identify the state at a glance by making each color of the engine rotation reduction width indicator lamp 74 multicolored such as a rainbow color. If the lowering range is set manually by the engine rotation lowering range indicator light 74, it can be determined whether or not the number of rotations of the engine E has been reduced. You can know the amount of reduction. Therefore, according to the configuration in which the engine rotation reduction width setting dial 70 is further provided with the engine rotation reduction width indicator lamp 74 that presents the reduced reduction width, the fuel can be reliably saved without requiring an operation by the operator. The tractor 10 can be provided to indicate to the operator that the Note that the display of the current reduction range of the engine E may be performed on the instrument panel 40.

  The engine rotation reduction width setting dial 70 can also be configured such that its function is stopped at the operator's discretion. In the example of FIG. 3, the engine rotation reduction width setting dial 70 is configured as a push button 75 that can perform a toggle operation for switching between a decrease in the rotation speed of the engine E and a stop. It should be noted that the switch for switching between the execution of the decrease in the rotational speed of the engine E and the stop may be provided at another location.

  Next, the instrument panel 40 will be described in detail. FIG. 4 is a schematic view of the main part of the instrument panel 40. The instrument panel 40 provided on the dashboard 16 (see FIG. 2) is located in front of the steering wheel 18 (see FIG. 2) as viewed from the operator seated on the driver's seat 20 (see FIG. 2). Therefore, the operator can confirm information on the instrument panel 40 by moving the line of sight slightly from the front during driving.

  The instrument panel 40 includes an engine speed display unit 41 that indicates the speed of the engine E with a pointer at the center. A plurality of display lamps 42 are provided on the left and right sides of the engine speed display unit 41. When each of the plurality of display lamps 42 is turned on, an abnormality of the tractor 10, a traveling state of the tractor 10, an operating state of the rotary tiller 30, and the like are indicated.

  The instrument panel 40 includes an information display unit 43 below the engine speed display unit 41. For the information display unit 43, for example, a touch panel type liquid crystal panel is used. The information display unit 43 displays various information about the tractor 10, warnings, and the like. The information includes the position of the reverser lever 51, the accumulated usage time (hour meter), the fuel remaining amount, the cooling water temperature, the vehicle speed, the rotational speed of the PTO shaft 25, the accumulated travel distance (odometer), the section travel distance (trip meter), There are various setting values for the tractor 10. The information display unit 43 can display a correct operation method, a warning message, an error message, and the like at the time of an erroneous operation.

  An operator can perform switching, selection, and the like of display items by touching the display of the information display unit 43. The information display unit 43 is not limited to a touch panel type, and may be operated by an operation button. In addition to the instrument panel 40, the tractor 10 according to the present embodiment is configured to display the above-described various information near the operator's eyes and easily operated, for example, in the vicinity of the armrest 56. May be.

  When the engine E is operating at a rated rotational speed, for example, 2600 rpm, and the work load has a margin, for example, when the load factor is about 50%, the rotational speed of the engine E is within a predetermined range, for example, 1500 to It is said that the fuel efficiency is improved by several tens of percent when it is lowered to 2100 rpm. Therefore, as illustrated in FIG. 4, the engine speed display unit 41 may be provided with an energy saving zone 44 as a mark in a speed range where the fuel efficiency is improved, for example, in the range of 1500 to 2100 rpm. Further, an energy saving lamp 45 that is turned on when the engine E is in the energy saving zone 44 and the work load is in a working state with a fuel efficiency of 45% or more, for example, greater than a predetermined value is a display lamp. It may be provided as 42 constituent elements. Further, an AUTO lamp 46 indicating that the amount of decrease in the rotational speed of the engine E is automatically adjusted may be provided as a component of the display lamp 42.

  Next, the control system of the tractor 10 according to the present embodiment will be described in detail. FIG. 5 is a principal block diagram of the control system of the tractor 10. The tractor 10 includes a body control unit 100, and the body control unit 100 is configured to control the operation of the tractor 10 and the rotary tiller 30 as a work device, and also enables various automatic controls. .

  The body control unit 100 is configured to control the operations of the tractor 10 and the rotary tiller 30 by reading input signals such as various set values and detection values by various sensors and outputting control signals. ing. The body control unit 100 includes a microcomputer including a CPU (Central Processing Unit) that performs arithmetic processing and control processing, a main storage device that stores data, a timer, an input circuit, an output circuit, a power supply circuit, and the like. Illustrated. A main storage device (not shown) exemplified by a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), and a RAM (Random Access Memory) has a control program for executing the operation according to this embodiment. Various data are stored. Note that data such as these various programs may be stored in an external storage unit and read by the body control unit 100.

  In addition, the structure of the body control part 100 is not specifically limited. The tractor 10 includes a plurality of control units, for example, control units that respectively control the engine E, display the instrument panel 40, control the rotary tiller 30, and the like, and each of them by in-vehicle communication such as CAN (Controller Area Network) communication. It may be configured to be able to communicate with each other. FIG. 5 illustrates a configuration in which an engine controller 101 that controls the operation of the engine E is electrically connected to the machine body control unit 100 via a CAN communication bus. The engine controller 101 includes a CPU, a main storage device, a timer, an input circuit, an output circuit, a power supply circuit, and the like, like the machine control unit 100. Therefore, in this embodiment, the airframe control unit 100 as the control unit and the engine controller 101 cooperate to control the tractor 10.

  The engine controller 101 is electrically connected to a starter switch 102, an accelerator sensor 103, a rotation sensor 104, and an electromagnetic solenoid of the fuel injection valve 105. Various sensors other than the configuration illustrated in FIG. 5 are electrically connected to the engine controller 101.

  The starter switch 102 serving as a starting unit is operated so that the engine E is started. The accelerator operating tool 106 serving as a rotation speed setting unit for adjusting the accelerator opening, such as the accelerator lever 50 and the accelerator pedal 55, is configured such that its operating position is detected by the accelerator sensor 103. A rotation sensor 104 serving as a rotation speed detection unit is provided on the output shaft of the engine E and is configured to detect the rotation speed of the engine E. As described above, the fuel injection valve 105 of the injector is configured as a rotation speed changing unit that injects fuel into the engine E when the valve is opened.

  The starter switch 102 may be a key cylinder type or a push button type. In the tractor 10 according to the present embodiment, when the starter switch 102 is turned on, the engine controller 101 operates the fuel injection valve 105 and transmits a control signal to a starter relay (not shown), and is operated by the starter relay (not shown). The engine E is configured to start by the power of the starter motor.

  In the main memory of the engine controller 101, for example, the EEPROM 110, output characteristics corresponding to the rotation speed and torque of the engine E are stored in advance as an output characteristic map M in a map format, for example.

  For example, the engine controller 101 uses the rotation speed of the engine E detected by the rotation sensor 104, the operation position of the accelerator operation tool 106 detected by the accelerator sensor 103, and the output characteristic map M to determine the rotation speed of the engine E. A target fuel injection amount that achieves the target rotational speed is calculated. Based on the result, the engine controller 101 is configured to output a control signal to the electromagnetic solenoid of the fuel injection valve 105 to execute fuel injection control. The fuel injection amount is adjusted, for example, by changing the opening time of the fuel injection valve 105. The tractor 10 is configured such that the fuel injection amount is output from the engine controller 101 to the body control unit 100.

  The body control unit 100 is electrically provided with a speed change actuator 108 that changes the speed change position of the speed change mechanism 107 of the tractor 10 and a speedometer 109 as a speed detection unit attached to the axles of the rear wheels 14 and 14, for example. It is connected. Note that various sensors other than the configuration illustrated in FIG. 5 are electrically connected to the body control unit 100.

  The speed change mechanism 107 is configured such that the speed change position is changed by driving the speed change actuator 108. The transmission mechanism 107 is configured by a continuously variable type such as a hydrostatic continuously variable transmission or a hydraulic mechanical continuously variable transmission.

  The speed change actuator 108 is, for example, a cylinder that changes and adjusts the inclination angle of the pump swash plate with respect to the axis of the input shaft of the speed change mechanism 107. The speed change actuator 108 is configured to be driven by the body control unit 100 in accordance with the speed change position of the main speed change lever 58. The shift actuator 108 is configured by an electric cylinder, a hydraulic cylinder, or the like. Therefore, the tractor 10 is configured to obtain a speed corresponding to the position of the main transmission lever 58.

  The speedometer 109 includes a magnetic pickup coil, a rotary encoder, and the like. The body control unit 100 reads the value of the speedometer 109 attached to the axles of the rear wheels 14 and 14, and feedback-controls the drive of the speed change actuator 108 so that the speed corresponding to the position of the main speed change lever 58 is obtained. It may be configured to.

  Further, an engine rotation reduction width setting dial 70 and an engine rotation reduction width indicator lamp 74 attached to the engine rotation reduction width setting dial 70 are electrically connected to the airframe control unit 100.

  As described above, the engine rotation reduction width setting dial 70 is for setting a reduction width of the rotation speed of the engine E. The engine controller 101 is configured to read the reduction width of the engine rotation reduction width setting dial 70 via the airframe control unit 100 and control the rotation speed to be reduced by the reduction width from the target rotation speed described above. ing. The engine speed reduction width indicator lamp 74 displays the current speed reduction range of the engine E. The airframe control unit 100 is configured to read the set value of the engine rotation reduction width setting dial 70 and instruct the engine rotation reduction width indicator lamp 74 to display the current reduction speed of the engine E.

  The engine controller 101 has a load calculation unit 111. The load calculation unit 111 is configured by a program, for example. The load calculation unit 111 calculates the current load factor of the engine E as a load. Here, the load factor of the engine E according to the present embodiment is the ratio of the actual torque at the present time with respect to the maximum torque (maximum engine load) at a predetermined rotation speed of the engine E. Note that the actual torque at the present time is obtained from the rotational speed of the engine E and the fuel injection amount. For the load factor, a load ratio of the PTO shaft 25 of the work machine may be used.

  The engine controller 101 further includes a determination unit 112. The determination unit 112 is also configured by a program, for example. The determination unit 112 determines whether or not the number of revolutions of the engine E can be reduced by the amount of reduction of the engine rotation reduction width setting dial 70.

  The number of revolutions of the engine E is controlled by the tractor 10 having the above configuration. Next, a method for controlling the tractor 10 according to the present embodiment will be described in detail. FIG. 6 is a flowchart of a method for controlling the tractor 10.

  First, the engine E is started by operating the starter switch 102 of the tractor 10 (step S1). When the engine E is started, the engine rotation reduction width setting dial 70 sets a reduction width of the rotation speed of the engine E (step S2).

As described above, the engine speed reduction range of the engine E is adjusted by the engine rotation reduction range setting dial 70 in the range of 100 min ⁻¹ to 800 min ⁻¹ . According to the method in which the lowering amount is adjusted in the range of 100 min ⁻¹ to 800 min ⁻¹ , a method for controlling the tractor 10 having workability corresponding to the load while reliably saving fuel is provided. Can do.

  Then, the body control unit 100 automatically reads the set value of the engine rotation reduction width setting dial 70 regardless of the operation by the worker (step S3). At this time, if the instruction unit 72 of the engine rotation reduction width setting dial 70 is at the AUTO position 73, the setting value is read into the machine control unit 100 as AUTO. The value read by the body control unit 100 is transmitted to the engine controller 101.

  Thus, the tractor 10 according to the present embodiment is configured such that the set value of the engine rotation reduction width setting dial 70 is automatically read in a state where the engine E is started. Therefore, it is possible to provide the tractor 10 having workability corresponding to the load while reliably saving fuel without requiring the operator to operate the eco-drive mode. On the other hand, as described above, the engine rotation reduction width setting dial 70 can also stop its function at the operator's discretion. However, in the tractor 10 according to the present embodiment, it is necessary to depress the push button 75 of the engine rotation reduction width setting dial 70 in order to decrease the rotational speed, that is, to stop the eco-operation mode. Therefore, in the tractor 10 according to the present embodiment, the function is not stopped unless the operator operates with the intention of stopping the eco-operation mode.

  Next, the target rotation speed of the engine E is set by operating the accelerator operating tool 106 by a worker (step S4). On the other hand, the rotation sensor 104 detects the rotation speed of the engine E (step S5). These values are read into the engine controller 101.

  Next, the engine controller 101 calculates a target fuel injection amount (step S6). More specifically, the engine controller 101 first outputs an output characteristic map M corresponding to the engine E rotation speed, the target engine E rotation speed, and the engine E rotation speed and torque stored in advance in the EEPROM 110. Is read. Next, the engine controller 101 uses these to calculate a target fuel injection amount such that the rotational speed of the engine E becomes the target rotational speed.

  Next, the fuel injection valve 105 changes the fuel injection amount to the engine E so that the rotation speed detected by the rotation sensor 104 becomes the target rotation speed set by the accelerator operating tool 106 (step S7). More specifically, the engine controller 101 outputs a control signal to the electromagnetic solenoid of the fuel injection valve 105 to execute fuel injection control. The fuel injection amount by the fuel injection valve 105 is read into the engine controller 101.

  Next, the load calculation unit 111 calculates the load factor of the engine E at the current time (step S8). As described above, the load factor of the engine E according to the present embodiment is the ratio of the actual torque at the current time with respect to the maximum torque (maximum engine load) at a predetermined rotation speed of the engine E. The actual torque at the present time is obtained from the rotational speed of the engine E and the fuel injection amount.

  Based on the current load factor of the engine E and the output characteristic map M, the determination unit 112 determines whether or not it is possible to decrease the rotational speed of the engine E by a reduction amount (step S9).

Here, an outline of the determination as to whether or not the rotational speed of the engine E can be reduced will be described. FIG. 7 is a schematic diagram showing an example of an output characteristic map M (rotational speed N-torque T diagram of engine E). In FIG. 7, the horizontal axis indicates the rotational speed N of the engine E, and the vertical axis indicates the torque T (load). The output characteristic map M shows the maximum torque Tm at a predetermined engine speed N. The output characteristic map M draws a convex mountain shape, and in the example, the torque T is maximum when the rotational speed N of the engine E is 2000 min ⁻¹ . Here, the most simplified determination and control method will be described.

For example, as indicated by a point a in FIG. 7, it is assumed that the current rotational speed N of the engine E is 2200 min ⁻¹ and the torque T is 250 N · m. Furthermore, it is assumed that the set value by the engine rotation reduction width setting dial 70 is 800 min ⁻¹ . In this case, when the rotational speed N of the engine E is decreased from 2200 min ⁻¹ to 800 min ^{−1 while the} torque T is kept constant at 250 N · m, 1400 as indicated by a point b. The maximum torque Tm at min ⁻¹ is exceeded. Therefore, in such a case, it is determined that the rotation speed N of the engine E cannot be reduced (step S9; NO). When it is determined that the rotation speed N of the engine E cannot be reduced (step S9; NO), the rotation speed N of the engine E is left as it is.

On the other hand, for example, as indicated by a point c, it is assumed that the current rotational speed N of the engine E is 2200 min ⁻¹ and the torque T is 200 N · m. Similarly, it is assumed that the set value by the engine rotation reduction width setting dial 70 is 800 min ⁻¹ . In this case, when the rotational speed N of the engine E is decreased from 2200 min ⁻¹ to 800 min ^{−1 while the} torque T is kept constant at 200 N · m, as indicated by a point d, 1400 It is below the maximum torque Tm at min- ¹ . Therefore, in such a case, it is determined that the rotational speed N of the engine E can be reduced (step S9; YES).

  As shown in FIG. 6, when it is determined that the rotation speed N of the engine E can be reduced (step S <b> 9; YES), the rotation speed N of the engine E is lowered by the engine rotation reduction width setting dial 70. It is lowered by the width (step S10). More specifically, the engine controller 101 reduces the target rotational speed in the above-described step S6 and step S7 by a reduction amount, and then the target fuel such that the rotational speed N of the engine E becomes the target rotational speed. The injection amount is calculated. Then, the engine controller 101 outputs a control signal to the electromagnetic solenoid of the fuel injection valve 105 to execute fuel injection control.

  In this way, the engine controller 101 determines whether or not the rotation speed N can be reduced based on the load factor by the determination unit 112, and if it is possible, the rotation speed is not changed and the rotation speed is not changed. The fuel injection valve 105 is controlled so as to reduce N. According to this method, it is possible to provide a method for controlling the tractor 10 that saves fuel reliably and as much as possible without requiring an operation by an operator.

  Here, when the setting of the engine rotation reduction width setting dial 70 is the AUTO position 73 in step S2, it is further determined whether or not the rotational speed N of the engine E can be reduced based on the reduction width. It may be made like this. That is, in the AUTO setting, control is performed so that the rotational speed N of the engine E is reduced to the maximum.

For example, as indicated by a point a in FIG. 7, it is assumed that the current rotational speed N of the engine E is 2200 min ⁻¹ and the torque T is 250 N · m. Then, it is determined whether or not the rotational speed N of the engine E can be decreased when the rotational speed N of the engine E is decreased by, for example, 100 min ⁻¹ . In the example of FIG. 7, as indicated by a point e, it is possible to decrease to 1800 min ⁻¹ and not to 1700 min ⁻¹ . Therefore, in the illustrated example, control is performed so that the rotational speed N of the engine E is reduced to 1800 min ⁻¹ . In this case, it is preferable from the viewpoint of fuel saving or the like that the maximum value of the lowering range for which determination is made is set in advance, for example, 800 min ⁻¹ . Further, the step size of the rotational speed N of the engine E for which it is determined whether or not the reduction is possible may not be 100 min ⁻¹ .

  In this way, the engine controller 101 further determines whether or not the rotation speed N of the engine E can be reduced based on the lowering range by the determination unit 112, and if it is possible, does not change the traveling speed. In addition, the fuel injection valve 105 is controlled so as to reduce the rotational speed N. According to this method, it is possible to provide a method for controlling the tractor 10 that reliably saves fuel without requiring an operation by an operator and has workability according to the load.

  In the above-described example, since only the torque T is kept constant so that the rotational speed N of the engine E is reduced, no consideration is given to output and fuel consumption. In the method according to the present embodiment, control may be performed so that the rotational speed N of the engine E is reduced based on the output and fuel consumption. For example, when the fuel efficiency is increased even if the engine speed N is reduced, the engine speed N may be controlled to be left as it is. Furthermore, control may be performed so as to determine whether or not it is possible to reduce the rotational speed N of the engine E based on the iso-output line.

Here, a signal indicating that the rotational speed N of the engine E has been reduced is transmitted from the engine controller 101 to the machine control unit 100. Then, the body control unit 100 may send a signal to the engine rotation reduction width indicator lamp 74 (see FIG. 3) so as to present the current reduction width of the engine speed N by light emission. In the example described above, it is only necessary that the 800 min ⁻¹ portion of the engine rotation reduction width indicator lamp 74 emits light. As described above, the engine rotation reduction width indicator lamp 74 further provided in the engine rotation reduction width setting dial 70 presents the lowered reduction width. Accordingly, it is possible to provide a method for controlling the tractor 10 that indicates to the worker that fuel is being saved reliably without requiring an operation by the worker.

  Further, the airframe control unit 100 has a fuel-efficient working state in which the rotational speed N of the engine E is in the range of the energy saving zone 44 (see FIG. 4) and the work load is a predetermined value or more, for example, 45% or more. A signal may be sent so that the energy saving lamp 45 (see FIG. 4) is lit. Further, the airframe control unit 100 may send a signal so that the AUTO lamp 46 (see FIG. 4) is lit when the reduction range of the rotational speed N of the engine E is automatically adjusted.

  While the rotation speed N of the engine E is controlled, the speedometer 109 detects the traveling speed (step S11). Then, the speed change mechanism 107 adjusts the traveling speed (step S12). If the rotational speed N of the engine E is decreased in step S10, the traveling speed of the tractor 10 is also decreased as it is. Therefore, the airframe controller 100 adjusts the gear ratio by driving the speed change actuator 108 of the speed change mechanism 107 based on the detected value of the speedometer 109, and the traveling speed before the rotational speed N of the engine E decreases is reduced. Control to be maintained. Airframe control unit 100 controls so that the traveling speed of tractor 10 is maintained even when engine speed N is not decreased (step S9; NO).

  And after control of the rotation speed N of the engine E and control of traveling speed are performed, a process returns to step S2. Then, when the traveling of the tractor 10 stops and the engine E is turned off, the control ends.

  As described above, in this embodiment, the starter switch 102 starts the engine E, the accelerator operating tool 106 sets the target rotation speed of the engine E, and the rotation sensor 104 detects the rotation speed N of the engine E. The fuel injection valve 105 changes the fuel injection amount to the engine E so that the rotation speed N detected by the rotation sensor 104 becomes the target rotation speed set by the accelerator operating tool 106, and the speedometer 109 The speed is detected, the speed change mechanism 107 adjusts the traveling speed, the engine controller 101 calculates the load of the engine E based on the rotational speed N, and the tractor 10 that controls the rotational speed N and the traveling speed. In the control method, the engine rotation lowering range setting dial 70 sets the lowering range of the rotation speed N, the starter switch 102 is operated, and the engine E is started. , The engine controller 101 controls the rotational speed N is lowered by the amount of the width reduced from the target speed.

  Therefore, according to the present embodiment, it is possible to provide a method for controlling the tractor 10 that reliably saves fuel without requiring an operation by an operator.

  As described above, the tractor 10 according to the present embodiment is configured such that the eco-operation mode functions already in a state where the engine E is started. Therefore, since the eco-operation mode is always set even if the worker is not conscious of anything, fuel can be reliably saved without requiring any operation by the worker.

Further, an AUTO position 73 is prepared on the engine rotation reduction width setting dial 70. Therefore, when an operation that does not require fine setting is performed, an operation that saves fuel can be performed very easily. On the other hand, the tractor 10 can set the reduction amount of the rotational speed N of the engine E finely in increments of 100 min ^{−1 in} the range of 100 min ⁻¹ to 800 min ⁻¹ , for example. Accordingly, while the eco-operation mode is functioning, the engine speed N is not automatically set, but can be set to the operator's desired speed N, and the engine E stops suddenly. That is, no engine stall occurs. This is particularly effective when the load fluctuation is large. And the tractor 10 which concerns on this embodiment can implement | achieve coexistence with the high working precision with which the rotation speed N required for work | work was maintained, and fuel saving.

  As described above, the engine E, the starter switch 102 that starts the engine E, the accelerator operating tool 106 that sets the target rotation speed of the engine E, the rotation sensor 104 that detects the rotation speed N of the engine E, and the rotation sensor A fuel injection valve 105 that changes the fuel injection amount to the engine E so that the rotational speed N detected by the 104 becomes a target rotational speed set by the accelerator operating tool 106; a speedometer 109 that detects the traveling speed; In a tractor 10 that includes a speed change mechanism 107 that adjusts the speed, a load on the engine E based on the rotational speed N, and a body control unit 100 and an engine controller 101 that control the rotational speed N and the traveling speed. Further provided is an engine rotation reduction width setting dial 70 for setting a reduction width of the rotational speed N, and the starter switch 102 is operated. When the engine E is started, the engine controller 101 is configured to control the rotational speed N of reduced width reduced from the target speed.

  And according to this embodiment, the tractor 10 which performs the saving of fuel reliably without requiring the operation by an operator can be provided.

  The work vehicle of the present invention is not limited to the combination of the tractor 10 and the rotary tiller 30. For example, the work vehicle such as a transplanter, a seedling planting device, a construction machine, and an attachment is used. The present invention can be applied to any work vehicle in which the load of the engine E fluctuates when the machine and the work device are combined and the work state of the work device changes.

10 Tractor (work vehicle)
40 Instrument panel (display section)
70 Engine rotation lowering width setting dial
74 Engine rotation lowering width indicator (indicator)
100 Airframe control unit (control unit)
101 Engine controller (control unit)
102 Starter switch (starting part)
104 Rotation sensor (Rotation speed detector)
105 Fuel injection valve (rotation speed changing part)
106 Accelerator (Rotation speed setting part)
107 Speed change mechanism 109 Speedometer (speed detector)
111 Load Calculation Unit 112 Judgment Unit E Engine

Claims (6)

Engine,
A starter for starting the engine;
A rotational speed setting unit for setting a target rotational speed of the engine;
A rotational speed detector for detecting the rotational speed of the engine;
A rotation speed changing section that changes a fuel injection amount to the engine so that the rotation speed detected by the rotation speed detection section becomes the target rotation speed set by the rotation speed setting section;
A speed detector for detecting the traveling speed;
A transmission mechanism for adjusting the traveling speed;
In a work vehicle that calculates a load of the engine based on the rotational speed and includes a control unit that controls the rotational speed and the traveling speed.
A rotation speed adjustment unit for setting a reduction width of the rotation speed;
When the starting unit is operated and the engine is started, the control unit is configured to control to the rotational speed that is reduced from the target rotational speed by an amount corresponding to the reduction width. Work vehicle. The control unit determines whether or not the rotation speed can be reduced based on the load, and when it is possible, the rotation speed is decreased without changing the traveling speed. The work vehicle according to claim 1, wherein the work vehicle is configured to control a number changing unit and the speed change mechanism. The control unit further determines whether or not the rotation speed can be reduced based on the amount of decrease, and if possible, reduces the rotation speed without changing the traveling speed. The work vehicle according to claim 2, wherein the work speed change unit and the speed change mechanism are controlled. 4. The work vehicle according to claim 1, wherein the lowering width is configured to be adjusted in a range of 100 min ⁻¹ to 800 min ⁻¹ . 5. The work vehicle according to claim 1, wherein the lowering width is configured to be adjusted in increments of 100 min ⁻¹ . The work vehicle according to any one of claims 1 to 5, wherein the rotation speed adjustment unit further includes an indicator for presenting the lowered width that has been lowered.

Images