JP2009284875A - Tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tractor easily recognizable of a proper vehicle speed for maintaining tilling depth or a proper tilling depth for maintaining a vehicle speed. <P>SOLUTION: The tractor comprises an engine provided with a common rail and an ECU for controlling the engine and an implement. The tractor is configured to comprise a tilling depth setting means for setting the depth to be tilled by the implement, an automatic tilling switch for setting the state of the function of the tilling depth setting means on, a selecting switch for selecting depth of tilling preference or vehicle speed preference when the automatic tilling switch is on, the implement is driven in a state when the automatic tilling switch is on and the depth of tilling preference or vehicle speed preference is selected, and the ECU detects the load factor and transmit it to the machine side when a working travel is started and the controlling system computes vehicle speed for maintaining the depth of tilling or vehicle speed for maintaining the tilling depth and displays on a monitor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tractor that is an agricultural machine.

Conventionally, a technique for measuring an engine load and changing the output of the engine in accordance with a change in the load is known (see, for example, Patent Document 1).
JP-A-1-253532

    The above-mentioned known technique detects a simple engine load and quickly changes the performance curve so as to obtain an appropriate load. However, there is no disclosure of a technique for notifying in order to maintain the tilling depth or the vehicle speed in accordance with the load on the work implement during the work travel of the tractor.

  The subject of this invention is providing the work vehicle which eliminates the above malfunctions.

The above object of the present invention is achieved by the following configuration.
That is, according to the first aspect of the present invention, in the tractor on which the engine (E) having the common rail (1), the ECU (100) for controlling the engine (E), and the work implement (21) are mounted, The tilling depth setting means (30) for setting the tilling depth by the machine (21), the automatic tilling depth switch (30a) for turning on the function of the tilling depth setting means (30), and the automatic tilling depth switch (30a) A selection switch (30b) is provided for selecting the plowing depth priority or the vehicle speed priority when the automatic plowing depth is on, and the plowing depth priority or the vehicle speed priority is set by the selection switch (30b) when the automatic plowing depth switch (30a) is on. When the working machine (21) is driven and the working travel is started in a state where any one of these is selected, the ECU (100) detects the load factor and transmits it to the control device (200) on the machine side. And the system Device (200) is obtained by a tractor, characterized in that the display on the monitor (M) to calculate the depth plowing for maintaining the vehicle speed to maintain the Kofuka, or vehicle speed.

  The plowing depth is set by the plowing depth setting means (30), and the automatic plowing depth switch (30a) that turns on the function of the plowing depth setting means (30) is turned on. Then, the plowing depth priority or the vehicle speed priority is selected by the selection switch (30b). When the working machine (21) is driven in this state to start working, the ECU (100) detects the load factor and transmits it to the control device (200) on the machine side. The control device (200) calculates the vehicle speed for maintaining the plowing depth or the plowing depth for maintaining the vehicle speed and displays it on the monitor (M).

  The invention according to claim 2 is characterized in that when the automatic tilling switch (30a) is in the off state, the load state of the engine (E) is displayed on the monitor (M). It is a tractor.

  When the automatic tilling switch (30a) is in the off state, the load state of the engine (E) is displayed on the monitor (M).

  Since the present invention is configured as described above, in the first aspect of the invention, an appropriate vehicle speed for maintaining the tilling depth or an appropriate tilling depth for maintaining the vehicle speed is displayed on the monitor (M). Therefore, good work can be performed without increasing the load on the engine (E). In addition, excessive consumption of fuel can be suppressed.

  In the invention of claim 2, in addition to the effect of claim 1, when the automatic tilling switch (30a) is in the off state, the load state of the engine (E) is displayed on the monitor (M). The load state of the engine (E) can be easily checked, and depending on the situation, the automatic plowing depth switch (30a) and the selection switch (30b) are turned on, and an appropriate vehicle speed or vehicle speed for maintaining the plowing depth. It is possible to quickly grasp the proper tilling depth for maintaining the plant.

The best mode for carrying out the present invention will be described.
FIG. 1 is an overall configuration diagram of a pressure accumulation type fuel injection device. The accumulator type fuel injection device is applied to, for example, a multi-cylinder diesel engine, but may be a gasoline engine. The accumulator fuel injection device pressurizes the common rail 1 that accumulates high-pressure fuel corresponding to the injection pressure, the pressure sensor 2 attached to the common rail 1, and the fuel pumped up from the fuel tank 3, and pumps the fuel to the common rail 1. A high-pressure pump 4, a fuel injection nozzle 6 for injecting high-pressure fuel accumulated in the common rail 1 into the cylinder 5 of the engine E, a control device (ECU) for controlling the operation of the high-pressure pump 4, the fuel injection nozzle 6 and the like Consists of ECU is an abbreviation for engine control unit.

As described above, the common rail 1 injects fuel to each cylinder 5 of the engine E, and supplies the fuel with a required pressure.
The fuel in the fuel tank 3 is sucked into the high-pressure pump 4 driven by the engine E through the fuel filter 7 through the suction passage, and the high-pressure fuel pressurized by the high-pressure pump 4 is guided to the common rail 1 through the discharge passage 8. Stored.

    The high-pressure fuel in the common rail 1 is supplied to the fuel injection nozzles 6 for the number of cylinders through the high-pressure fuel supply passages 9, and the fuel injection nozzles 6 are operated to the respective cylinders based on commands from the ECU 100. The surplus fuel (return fuel) from each fuel injection nozzle 6 is guided to a common return passage 10 by each return passage 10 and returned to the fuel tank 3 by this return passage 10.

    In addition, a pressure control valve 11 is provided in the high-pressure pump 4 to control the fuel pressure (common rail pressure) in the common rail 1. The pressure control valve 11 is connected to the fuel tank 3 from the high-pressure pump 4 by a duty signal from the ECU 100. The flow area of the return passage 10 for surplus fuel to the fuel is adjusted, whereby the amount of fuel discharged to the common rail 1 side can be adjusted to control the common rail pressure.

    Specifically, the target common rail pressure is set according to the engine operating conditions, and the common rail pressure is feedback-controlled through the pressure control valve 11 so that the common rail pressure detected by the rail pressure sensor 2 matches the target common rail pressure. It is configured.

    As shown in FIG. 2, the ECU 100 of the diesel engine E having the common rail 1 in the work vehicle (agricultural work machine) has three types of modes, a travel mode A, a normal work mode B, and a heavy work mode C in relation to the rotational speed and the output torque. The configuration has a control mode.

    The traveling mode A is droop control in which the output also varies with the variation of the engine speed. It is used when traveling without farming. For example, when the traveling speed is reduced or stopped by applying a brake, the engine speed decreases with an increase in the traveling load, so that the traveling speed can be safely reduced or stopped.

    The normal work mode B is isochronous control in which the engine speed is constant and the output is changed according to the load even when the load varies. It is used for normal farm work. For example, if it is a tractor, it is when the cultivated land is hard during plowing work and resistance is applied to the plowing blade. Is the time.

    In the heavy work mode C, in addition to the isochronous control in which the engine speed is constant and the output is changed according to the load even when the load fluctuates in the same manner as the normal work mode B, the engine speed is increased when the load is close to the limit. This is a control with heavy load control that increases In particular, it is used when farming near the load limit. For example, when plowing with a tractor, the engine output increases beyond the normal limit even when encountering hard cultivated land, so work can be performed efficiently without interruption. .

    These work modes A, B, and C are operations of a work mode changeover switch that can switch between the work modes A, B, and C, or a shift operation of a traveling speed change lever of a farm vehicle (tractor, combine, rice transplanter, etc.) Alternatively, it is configured to be switched by an on / off operation or the like of a work clutch (rotary if it is a tractor, and mowing part or threshing part if it is a combine).

    In diesel engine E, pilot injection that injects a small amount of fuel in a pulse manner prior to main injection makes it possible to shorten the ignition delay, reduce the knocking noise peculiar to diesel engine E, and reduce noise It has a simple structure.

    This pilot injection is performed only once or twice before the main injection. By using the accumulator fuel injection device of the common rail 1, pilot injection is performed according to the situation of the engine E. Thus, it becomes possible to reduce the noise and the generation of white smoke or black smoke due to incomplete combustion. Further, by performing pilot injection in which a small amount of fuel is pulse-injected prior to main injection, the amount of nitrogen oxides in the exhaust gas is reduced.

  FIG. 3 shows a side view of a tractor equipped with a diesel engine having the common rail 1 as described above, and FIG. 4 shows a plan view thereof. In the plan view, the cabin 14 shown in FIG. 3 is omitted.

  The tractor includes front wheels 12 and 12 and rear wheels 13 and 13 at the front and rear portions of the fuselage, and the rotational power of the engine E mounted on the front portion of the fuselage is appropriately decelerated by a transmission in the transmission case T so that the front wheels 12 , 12 and the rear wheels 13, 13.

  A steering handle 16 is supported on the handle post 15 in the cabin 14 at the center of the body, and a seat 17 is provided behind the steering handle 16. A forward / reverse lever 18 is provided below the steering handle 16 to switch the advancing direction of the aircraft to the front / rear direction. When the forward / reverse lever 18 is moved to the front side, the aircraft moves forward, and when it is moved backward, the aircraft moves backward.

    Further, an accelerator lever 25 for adjusting the engine speed is provided on the opposite side of the forward / reverse lever 18 with the handle post 15 interposed therebetween, and an accelerator for similarly adjusting the engine speed is provided at the right corner of the step floor 19. The pedal 23 and left and right brake pedals 24L, 24R for operating the left and right rear wheels 13, 13 are provided. A clutch pedal 20 is provided at the left corner of the step floor 19.

  The main transmission lever 26 is located at the left front portion of the seat 17, the auxiliary transmission lever 27 capable of selecting any one of the low speed, medium speed, high speed and neutral positions is located behind the main transmission lever 26. Is provided. Further, on the right side of the seat 17, a position lever 29 for setting the height of the working machine 21 (rotary or the like), an automatic tilling lever 30 for automatically setting the tilling depth of the field, and the working machine 21 after these levers. The right-up switch 31 and the right-down switch 32 are arranged, and then the automatic horizontal switch 33 and the backup switch 34 of the work machine 21 are arranged. The backup switch 34 automatically raises the work machine 21 when the machine moves backward. The work machine 21 has a configuration in which a link 22 is connected to the rear of the machine body. The tractor performs work such as tillage in the field by driving the work machine 21 and running the machine body. 21a is a hydraulic cylinder which raises / lowers the working machine 21.

  A control device 200 on this machine side is connected to the ECU 100 shown in FIG. This control device 200 includes a plowing depth setting means (automatic plowing depth lever) 30 for automatically setting the plowing depth of the field, an automatic plowing depth switch 30a for turning on the functions of the plowing depth setting means 30, and a plowing depth. A selection switch (30b) for selecting either priority or vehicle speed priority and a monitor (M) are connected. FIG. 4 shows these arrangement positions.

  Then, when the automatic plowing depth switch 30a is in the on state, when the working switch 21 is driven in the state where either the plowing depth priority or the vehicle speed priority is selected by the selection switch 30b, the work traveling is started. The ECU 100 detects the engine load factor and transmits it to the control device 200 on the machine side. The control device 200 calculates the vehicle speed for maintaining the plowing depth or the plowing depth for maintaining the vehicle speed to the monitor M. It is configured to display. The engine load state is detected from the fuel injection state and the engine speed sensor E1, but other means may be used.

    As a result, an appropriate vehicle speed for maintaining the plowing depth or an appropriate plowing depth for maintaining the vehicle speed is displayed on the monitor M, so that good work can be performed without increasing the load on the engine E. In addition, excessive consumption of fuel can be suppressed. In particular, since the common rail 1 is mounted on the engine, fuel injection control for maintaining an appropriate vehicle speed can be performed with high accuracy, and fuel efficiency is improved.

  Further, the load state of the engine E is displayed on the monitor M when the automatic tilling switch 30a is in the cut state. Thus, when the automatic tilling switch 30a is in the off state, the load state of the engine E is displayed on the monitor M, so that the operator can easily check the load state of the engine E, and depending on the situation, the automatic tilling depth With the switch 30a and the selection switch 30b turned on, it is possible to quickly grasp the appropriate vehicle speed for maintaining the tilling depth or the appropriate tilling depth for maintaining the vehicle speed.

  FIG. 5 will be described. ECU 100 detects that the external load of the engine is neutral. As a detection method, the neutral of the traveling mission is detected or the fact that the traveling clutch is depressed is detected by a switch or the like. Moreover, the stop state of the work machine 21 is detected by a mission, a drive lever, a switch, or the like. The air conditioner is switched off and detects the state.

The fact that there is no external load is transmitted from the control device 200 on the machine body side to the ECU 100 by CAN communication or the like.
In such a state, it is determined whether or not the fuel injection amount at the time of low idling is within a set value, and if it is greater than or equal to the set value, an alarm is issued as an engine friction abnormality. As a condition, it is assumed that the fuel injection amount set value at the time of low idling takes into account the charging load and the drag load of the working machine hydraulic pump.

This makes it possible to detect problems in the engine (piston ring sticking, piston seizure, metal seizure, valve sliding failure, etc.) at an early stage.
FIG. 6 will be described. The balancer housing 35 is disposed so as to protrude in the lateral direction of the cylinder block 36, and the high pressure pump 4 for fuel pressure feeding is provided below the balancer housing 35. Thereby, the high pressure pump 4 can be protected from falling objects such as tools.

  The ECU 100 includes a high torque map TM1 and a low torque map TM2 for normal work as shown in FIG. When the eco mode switch (not shown) provided in the driver's seat is turned on, the low torque map TM2 for low fuel consumption work is used. At this time, the main injection timing from the common rail 1 is advanced. Constitute. This synergistic effect further improves fuel economy. Further, in the low torque map TM2, the rated rotational speed may be reduced as in the line L1.

  The high torque map TM1 may be used during work, and the low torque map TM2 may be used during simple travel. Thereby, useless fuel consumption at the time of foot accelerator can be reduced.

Next, torque limitation will be described.
As shown in FIG. 8, a torque limit line L3 is configured for the full load torque line L2. Further, as shown in FIG. 9, the torque limit value is increased as the main shift position becomes higher (line L4). In this way, by limiting the torque, it is possible to cut a region where the fuel injection amount at the beginning of acceleration increases greatly, and by making the acceleration itself moderate, it is possible to suppress an increase in fuel consumption. In addition, it is possible to suppress an increase in fuel consumption due to the use of a region with a low fuel consumption rate in a low rotation and high load region due to depression of the accelerator with a high speed gear.

  The DPF 37 in FIG. 10 will be described. The exhaust gas discharged from the cylinder 5 of the engine passes through the aftertreatment device and is discharged from the muffler to the atmosphere. The aftertreatment device is composed of an oxidation catalyst (DOC) and a diesel particulate filter (DPF) 37.

The oxidation catalyst (DOC) burns the incombustible material chamber, and the diesel particulate filter (DPF) 37 is for collecting particulate matter (PM).
When the state of the exhaust gas is low (low load) continues for a long time, DPF 37 accumulates PM, and there is a concern that the capacity may be reduced. Therefore, the bypass circuit 38 is provided as shown in FIG. When PM accumulates in the DPF 37, the pressure on the upstream side increases, and this pressure is measured by the pressure sensor 39. When the pressure exceeds a predetermined value, the regulating valve 40 is opened and the exhaust gas is passed to the bypass circuit 38. (Fig. 10 (b)). FIG. 10A shows a normal case. As a result, even if an abnormal state in which the DPF 37 is not regenerated continues, the exhaust gas is discharged, so that it does not affect the operation of the engine. However, since it is for emergency use, it is necessary to perform maintenance and inspection at an early stage.

  The performance curve in FIG. 11 will be described. Compared to the standard full load curve line L5, the maximum torque is reduced by about 20% and the injection timing in the rated high load range is advanced (2 to 4 degrees) to increase the rated output to the standard full load output. The full load curve line L6 in the fuel consumption mode is set to be equal to or less than that. Further, the lines L5 and L6 can be arbitrarily switched by a driver seat switch (not shown).

  As a result, by suppressing the maximum torque value, even if the injection timing near the rating is advanced, the overall NOx emission rate does not change, the fuel consumption rate near the rating can be improved, and the fuel consumption can be reduced. Can be reduced.

    It can be used for farm vehicles such as tractors and combiners as well as general vehicles.

Overall configuration diagram of accumulator fuel injection system Diagram showing the relationship between engine speed and output torque in control mode Left side view of tractor Top view of tractor Block diagram of engine ECU and main unit control device Engine perspective view Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and output torque Diagram showing torque limit value (A) Cross section of diesel particulate filter (b) Cross section of diesel particulate filter Diagram showing the relationship between engine speed and output torque

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Common rail 21 Working machine 30 Plowing depth setting means 30a Automatic plowing depth switch 30b Selection switch 100 ECU
200 Machine side controller E Engine M Monitor

Claims (2)

  In the tractor equipped with the engine (E) equipped with the common rail (1), the ECU (100) for controlling the engine (E), and the work machine (21), the plowing depth by the work machine (21) is set. Plowing depth setting means (30), automatic plowing depth switch (30a) for turning on the function of plowing depth setting means (30), or plowing depth priority when the automatic plowing depth switch (30a) is turned on or A selection switch (30b) for selecting vehicle speed priority is provided, and when either the automatic plowing depth switch (30a) is in the on state, either the plowing depth priority or the vehicle speed priority is selected by the selection switch (30b). When the work machine (21) is driven to start working, the ECU (100) detects the load factor and transmits it to the control device (200) on the machine side, and the control device (200) To keep the depth Of the vehicle speed, or tractor, characterized in that to calculate the depth plowing for maintaining the vehicle speed is displayed on the monitor (M).   The tractor according to claim 1, wherein when the automatic tilling switch (30a) is in a cut state, a load state of the engine (E) is displayed on the monitor (M).

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