JP2017155617A - Tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a fuel consumption through an appropriate selection of a mode at an engine having a standard mode and a low fuel consumption mode.SOLUTION: This invention relates to a tractor installed with an engine E having a common rail 1, an ECU 100 for controlling the engine E and a work machine 21. The tractor has a feature that a performance curve indicating a relation between an engine speed and a torque in the ECU 100 is constituted at least by a standard mode line L1 and a low fuel consumption mode line L2, and when the tractor is travelling for work under the standard mode line L1 and a state in which an engine load factor is a specified value or less is continued for more than a specified time, a display for promoting a changing-over to the low fuel consumption mode line L2 is displayed on a monitor M installed at the tractor.SELECTED DRAWING: Figure 5

Description

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

  Conventionally, a configuration in which the state of a working machine mounted on a machine body is determined and the output of the engine is switched to a standard mode or an energy saving mode is known (for example, see Patent Document 1).

JP 2007-231848 A

  The above-mentioned known technique is a configuration for switching the engine output to the standard mode or the energy saving mode. However, if an appropriate selection of the standard mode or the energy saving mode is not performed, improvement in fuel consumption may not be expected.

  An object of the present invention is to eliminate the above-described problems.

  The above object of the present invention is achieved by the following configuration.

  That is, in the invention according to claim 1, in the tractor equipped with the engine (E) having the common rail (1), the ECU (100) for controlling the engine (E), and the work implement (21), the ECU In (100), a performance curve indicating the relationship between the engine speed and the torque is composed of at least a standard mode line (L1) and a low fuel consumption mode line (L2), and the vehicle is running on the standard mode line (L1). A tractor characterized in that, when a state below a predetermined value of the engine load factor continues for a predetermined time or longer, a display prompting a change to the low fuel consumption mode line (L2) is performed on a monitor (M) provided in the tractor; It is what.

  In the second aspect of the present invention, after the display for prompting the change to the low fuel consumption mode line (L2) is performed on the monitor (M), the display is not changed to the low fuel consumption mode line (L2) even if a predetermined time elapses. 2. The system according to claim 1, wherein the automatic change to the low fuel consumption mode line (L <b> 2) and the automatic change to the low fuel consumption mode line (L <b> 2) are displayed on the monitor (M). It is a tractor.

  In a third aspect of the present invention, a dashboard (51) comprising a mode changeover switch (50) for switching between the standard mode line (L1) and the low fuel consumption mode line (L2) and equipped with a monitor (M). The tractor according to claim 1 or 2, wherein the mode changeover switch (50) is provided.

  Since the present invention is configured as described above, according to the first aspect of the present invention, even when the vehicle is running, even the standard mode line L1 can be handled by the low fuel consumption mode line L2, and the fuel consumption is improved.

  In addition to the effect of the first aspect, the invention according to claim 2 is automatically changed even if forgetting to change the low fuel consumption mode line L2, so that the fuel consumption is improved, and the automatic change to the low fuel consumption mode line L2 is achieved. Can be easily recognized.

  In the third aspect of the invention, in addition to the effect of the first or second aspect, the mode changeover switch 50 is arranged on the right side of the dashboard 51 to which the monitor M is attached, so that the operation becomes easy.

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 Diagram showing the relationship between engine speed and output torque Schematic diagram of intake to exhaust Flow chart Diagram showing the relationship between engine speed and output torque Flow chart Schematic diagram of engine intake and exhaust systems Block diagram of engine exhaust system control

  The best mode for carrying out the present invention will be described.

  In addition, although each Example described later is illustrated or described separately or mixed for easy understanding, these can be combined in various ways, and can be configured according to their description order and expression. -The action and the like are not limited, and there are of course cases where a synergistic effect is produced.

  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 35 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.

  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 in between, 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 of the low speed, medium speed, high speed and neutral positions is located behind the main transmission lever 26, and further on the right side thereof is the PTO transmission lever 28. 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.

  The ECU 100 shown in FIG. 1 is connected to a control device 200 on the machine side. 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 display means (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 is a performance curve showing the relationship between the engine speed and the torque. The line L1 indicates the standard mode (power mode), and the line L2 indicates the low fuel consumption mode. The maximum torque point of the standard mode line L1 is T1, and the maximum torque point of the low fuel consumption mode line L2 is T2. The switching selection between the standard mode line L1 and the low fuel consumption mode line L2 is performed by the fuel consumption mode dial 36 (FIG. 4). As a form of the fuel consumption mode dial 36, an on / off type switch (a fuel consumption mode in an on state) or a changeover switch for switching to either one may be used.

  As shown in FIG. 6, an aftertreatment device 37 is provided in the exhaust system of the engine E. The exhaust gas passes through the aftertreatment device 37 and is discharged from the muffler 38 to the atmosphere. The post-processing device 37 includes an oxidation catalyst (DOC) 39 and a diesel particulate filter (DPF) 40.

  The oxidation catalyst (DOC) 39 burns the incombustible chamber, and the diesel particulate filter (DPF) 40 is for collecting the granulated material (PM). As a property of the DPF 40, when the state of the exhaust gas is low (low load) continues for a long time, PM accumulates in the DPF 40 and the trapping ability is lowered. Reference numeral 42 denotes an EGR valve, and reference numeral 41 denotes an EGR reduction circuit. Reference numeral 43 denotes a burner that burns off PM in the exhaust gas.

  As shown in the flowchart of FIG. 7, when working on the standard mode line L1, the load factor is continuously calculated by the ECU 100, and the engine load factor is low (about 80 minutes) for a predetermined time (about 5 minutes). % Or less) continues, it is configured to display on the monitor M that the fuel consumption is improved by switching to the low fuel consumption mode line L2. The state where the engine load factor is low (about 80% or less) varies depending on how the fuel efficiency mode line L2 is set with respect to the standard mode line L1.

  As a result, even when the vehicle is working, even the standard mode line L1 can be handled by the low fuel consumption mode line L2, thereby improving the fuel consumption. Switching between the standard mode line L1 and the low fuel consumption mode line L2 is performed by the mode switch 50 (FIG. 1). Further, as shown in FIG. 4, the mode changeover switch 50 is arranged on the right side of the dashboard 51 to which the monitor M is attached, so that the operation is easy.

  Further, after the display prompting the monitor M to change to the low fuel consumption mode line L2, if the predetermined time (about 2 to 3 minutes) has not passed and the change to the low fuel consumption mode line L2 is not made, the low fuel consumption mode is automatically set. Change to mode line L2. And it is set as the structure which displays on the monitor M that it changed into the fuel-efficient mode line L2 automatically.

  Thereby, even if it forgets to change the low fuel consumption mode line L2, since it is automatically changed, a fuel consumption improves and it can recognize easily that it was automatically changed to the low fuel consumption mode line L2.

  The standard mode line L3 and the low fuel consumption mode line L4 shown in FIG. 8 will be described. The output near the maximum torque point where there is a large amount of emissions is cut to reduce the overall emission rate. Next, the pressure of the common rail 1 is increased around the middle load and the high load portion of the rated rotation range, and the fuel injection timing is advanced. Thereby, the fuel consumption near rated rotation improves. At this time, NOx also increases at the same time, but is not different from the discharge rate of the standard mode line L3. Specifically, a low fuel consumption mode line L4 is configured in which the maximum torque point torque having a low EGR rate is greatly reduced with respect to the standard mode line L3. When the fuel efficiency mode line L4 is used, the pressure of the common rail 1 in the rated rotation middle and high load region is increased at the same time and the fuel injection timing is advanced.

  As a result, near the maximum torque point, the EGR reduction rate is low due to the increase in turbocharger efficiency, so the amount of NOx emissions is large, but this area is cut and NOx is allocated to the rated speed range. Thus, the overall NOx emission rate does not change, and the low fuel consumption mode line L4 with improved rated rotational fuel consumption can be created.

  The fuel injection nozzle 6 may be clogged depending on the usage environment and time. In order to detect the clogging of the fuel injection nozzle 6, the instruction injection amount instructed by the ECU 100 is compared with the actual fuel flow rate by the fuel flow meter provided in the fuel piping of the vehicle, and the actual fuel flow rate is 15% of the instruction injection amount. If it decreases to some extent, the engine output is maintained by correcting the indicated fuel injection amount. In addition, an instruction to perform maintenance is output to the monitor M.

  As another method for detecting clogging of the fuel injection nozzle 6, the theoretical exhaust gas temperature is compared with the actual exhaust gas temperature, and when the actual exhaust gas temperature is reduced by about 30 degrees with respect to the theoretical exhaust gas temperature, the indicated fuel injection amount is corrected. To maintain the engine output. Here, the theoretical exhaust temperature is an exhaust temperature predicted when the commanded fuel injection amount is combusted. The actual exhaust temperature is a value detected by a temperature sensor provided on the upstream side of the DOC (oxidation catalyst).

  Another method for detecting clogging of the fuel injection nozzle 6 is to compare the predicted remaining amount of the fuel tank based on the commanded fuel injection amount with the actual remaining amount of the fuel tank, and the difference is 15%. You may comprise so that it may determine by becoming. Specifically, the amount of deviation between the cumulative amount per day instructed for injection and the amount consumed in one day by a level sensor provided in the fuel tank is calculated, and the change of the amount of deviation with respect to the operation time is calculated. When it is stored and the amount of deviation continues to increase, the monitor M displays contents such as “abnormality of fuel injection nozzle”.

  In an engine equipped with an EGR reduction circuit 41 (FIG. 6), an EGR valve 42 that sends exhaust gas from the exhaust side to the intake side is provided. The NOx concentration in the exhaust gas is measured by a NOx sensor, and when the NOx concentration becomes high, the EGR valve 42 is opened to reduce a part of the exhaust gas to the intake side to lower the NOx concentration.

  Thereby, a part of the exhaust gas is sent to the intake side, so that the amount of NOx emission can be reduced. However, in the EGR valve 42, the EGR valve 42 may be stuck and not operate due to the influence of unburned fuel in the exhaust gas.

  Therefore, as shown in FIG. 9, the EGR valve 42 is configured to operate in advance for a predetermined time when the key switch is turned on at the time of starting the engine (power is turned on). If the engine starts within a predetermined time, the pre-operation of the EGR valve 42 ends. Further, the EGR valve 42 is configured to operate for a predetermined time even after the engine is stopped. After the engine stops, the timer is operated for a predetermined time regardless of whether the power is on or off. Thereby, it can prevent that the EGR valve | bulb 42 adheres and does not operate | move.

  When the engine coolant temperature is low (60 degrees or less), the EGR valve 42 is not opened regardless of the NOx concentration value. As a result, moisture in the exhaust gas is condensed and adheres to the EGR valve 42, and rust may be generated to cause the EGR valve 42 to be fixed or malfunction, but such a phenomenon can be prevented.

  When the engine coolant temperature reaches 60 degrees or higher, the EGR valve 42 is configured to be operable.

  Further, the EGR valve 42 is configured to be operable when about 10 minutes or more have elapsed after the engine is started.

  The EGR in FIG. 10 will be described. An EGR reduction circuit 59 is configured between the exhaust manifold 55 and the intake manifold 56 of the engine E. The EGR reduction circuit 59 is provided with a first EGR valve 52, an EGR cooler 54, a second EGR valve 53, and a temperature sensor 58. Yes. Reference numeral 57 denotes a turbo.

  The exhaust gas temperature is measured by the temperature sensor 58. When the temperature is high, the second EGR valve 53 is fully opened, and the EGR rate is controlled by the first EGR valve 52. When the exhaust gas temperature is low, the first EGR valve 52 is fully opened and the EGR rate is controlled by the second EGR valve 53. The temperature is controlled by changing the flow rate (time) at which the exhaust gas passes through the EGR cooler 54. Depending on the operation status, the EGR rate and the EGR gas temperature are controlled by individually controlling the first EGR valve 52 and the second EGR valve 53. The exhaust gas performance and fuel efficiency are improved by changing the EGR temperature according to the operating conditions.

  FIG. 11 shows a configuration in which two DPFs are provided in the exhaust system from the engine E. A switching valve 60 is provided in the piping 68 at the engine outlet and branches into a first piping 61 and a second piping 62. The first pipe is provided with a first pressure sensor 65, a first DPF 63, a second pressure sensor 66, a second DPF 64, and a third pressure sensor 67 from the upstream side to the downstream side. The second pipe 62 is connected between the first DPF 63 and the second DPF 64.

  A configuration in which the ECU 100 judges the engine operating condition (fuel injection amount, EGR rate, etc.) to predict the PM emission amount, and when it is determined that the PM emission amount is small, the exhaust gas is caused to flow through the second pipe 62 And Thereby, exhaust resistance is suppressed and fuel consumption improves. Further, when it is determined that the PM emission amount is large, the exhaust gas is caused to flow through the first pipe 61. Thereby, PM removal in exhaust gas is performed efficiently. Further, even when there are many operating conditions where the exhaust gas temperature is low, by switching between the first pipe 61 and the second pipe 62, it is possible to secure time until the forced regeneration of the DPF is necessary.

  When the DPF is mounted, particularly in a tractor that is an agricultural machine, if the DPF is forcibly regenerated or manually regenerated during work, the work efficiency decreases.

  Therefore, manual regeneration may be performed to some extent before the first work in the morning. In this case, it is necessary to perform manual regeneration by raising the exhaust gas temperature quickly. Therefore, the following control is performed.

  Since the cooling water temperature is low at the start of the engine, the intake valve is fully opened, but the intake valve is gradually throttled as the cooling water temperature rises. If the fuel is squeezed in a short time, a large amount of HC is discharged, but by gradually squeezing with the rise in the cooling water temperature, the fuel injection amount can be increased without increasing the HC.

  As the fuel injection amount increases, the cooling water temperature rises faster, resulting in a shorter warm-up operation time. Further, since the exhaust gas temperature rises as the fuel injection amount increases, it is possible to shorten the time until the catalyst is activated when manual regeneration is started after the warm-up stroke.

  Further, in the mecha governor type engine, when overheating occurs frequently, an error is transmitted to a user or a communication device at the user's home via a communication line. An error is transmitted when the number of overheating per hour is 3 or more. Specifically, the error type is “overheat”. Then, the communication device transmits a confirmation message to the monitor M of the tractor. Specifically, confirmation 1 is transmitted as confirmation of the cooling water amount, confirmation 2 as confirmation of LLC concentration, confirmation 3 as confirmation of clogging of the radiator, and confirmation 4 as confirmation of the amount of water in the reserve tank. As a result, the user who continues to use the device while frequently overheating can re-recognize the error through the communication device, and the failure can be minimized or minimized.

E Engine M Monitor L1 Standard mode line L2 Fuel efficient mode line 1 Common rail 21 Work implement 50 Mode changeover switch 51 Dashboard 100 ECU

Claims (3)

  An engine (E) provided with a common rail (1), an ECU (100) for controlling the engine (E), and a tractor equipped with a work implement (21), the engine speed and torque in the ECU (100). The performance curve indicating the relationship between the engine load factor and the fuel efficiency mode line (L2) is at least composed of the standard mode line (L1), and the vehicle is running on the standard mode line (L1) and is below a predetermined engine load factor. The tractor is characterized in that when the state of is continued for a predetermined time or longer, a display prompting the change to the fuel-efficient mode line (L2) is performed on a monitor (M) provided in the tractor.   After the monitor (M) is displayed to prompt the change to the low fuel consumption mode line (L2), if it does not change to the low fuel consumption mode line (L2) even after a predetermined time has elapsed, the low fuel consumption mode line is automatically set. 2. The tractor according to claim 1, wherein the tractor is configured to display (L2) and to automatically display on the monitor (M) the fuel efficient mode line (L2).   A mode changeover switch (50) for switching between the standard mode line (L1) and the low fuel consumption mode line (L2) is configured, and the mode changeover switch (50) is provided on the dashboard (51) equipped with the monitor (M). The tractor according to claim 1, wherein the tractor is provided.

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