JP2012052459A - Working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve efficient regeneration of a post-process device (DPF: diesel particulate filter) for cleaning exhaust gas and reduction of fuel consumption during regeneration in an engine that can operate in a standard mode or a low fuel consumption mode.SOLUTION: A working vehicle for carrying out various kinds of control on an engine (E) by an ECU (engine control unit) (100) is provided with a DPF (46b) that removes particulate matter (PM) in exhaust gas. The ECU (100) includes a performance curve showing a relation between an engine rotational speed and torque, comprising at least a standard mode line (L1) and a low fuel consumption mode line (L2), and is configured to inhibit regeneration of the DPF (46b) when the low fuel consumption mode line (L2) is executed.

Description

  The present invention relates to a work vehicle, and more particularly, to a performance curve of an engine mounted on the work vehicle and regeneration of a post-processing device.

  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, since a technology for regulating regeneration of the exhaust gas aftertreatment device (DPF) with the energy saving mode selected is not disclosed, regeneration of the DPF in the energy saving mode results in poor regeneration efficiency and poor fuel consumption. There is a drawback.

  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, according to the first aspect of the present invention, in the work vehicle in which the ECU (100) performs various controls of the engine (E), the DPF (46b) for removing the particulate matter (PM) in the exhaust gas is provided, and the ECU (100) includes at least a standard mode line (L1) and a low fuel consumption mode line (L2) as a performance curve indicating the relationship between the engine speed and torque, and the low fuel consumption mode line (L2) is executed. In this case, the work vehicle is configured so that the DPF (46b) is not regenerated.

  When the fuel efficiency mode line (L2) is being executed, the regeneration of the DPF (46b) is not performed.

  The invention according to claim 2 is configured to automatically select the fuel-efficient mode line (L2) and advance the fuel injection timing when the coolant temperature of the engine (E) is lower than a predetermined value. The work vehicle according to claim 1, wherein the work vehicle is a vehicle.

  When the coolant temperature of the engine (E) is lower than a predetermined value, the fuel efficiency mode line (L2) is automatically selected and the fuel injection timing is advanced.

  In the invention according to claim 3, when the regeneration of the DPF (46b) is not performed or when the fuel-efficient mode line (L2) is automatically selected and the fuel injection timing is advanced, the monitor ( The work vehicle according to claim 1 or 2, wherein the work vehicle is configured to be displayed in (M).

  When the regeneration of the DPF (46b) is not performed, or when the low fuel consumption mode line (L2) is automatically selected and the fuel injection timing is advanced, it is displayed on the monitor (M).

Since the present invention is configured as described above, in the invention described in claim 1, the regeneration efficiency of the DPF 46b is improved, and the consumption of fuel used during regeneration can be reduced. In the invention described in claim 2, In addition to the effect of the first aspect, misfiring at a low temperature can be prevented and the discharge amount of the granulated material PM can be reduced.

  In the invention described in claim 3, in addition to the effect described in claim 1 or claim 2, the operating state of the engine can be easily confirmed.

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 engine intake and exhaust systems Flow chart of DPF regeneration conditions Flow chart of transition to low fuel consumption mode Standard mode transition flowchart (A) Relationship between output and EGR rate (b) Relationship between output and NOx emissions Diagram showing the relationship between engine speed and output torque Top view of the working depth adjustment dial Right side view of tractor Schematic diagram of engine intake and exhaust systems Partial perspective view of tractor

  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 accumulating 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.

  FIG. 6 is a schematic diagram of intake and exhaust into the cylinder 5 of the engine, which is an embodiment of a four-cycle diesel engine. The air supercharged by the intake turbine 45 a of the supercharger TB passes through the intake turbine 45 a and the intercooler 37 from the air cleaner 67 and is sent from the intake manifold 38 into the cylinder 5. Reference numeral 39 is an intake valve, and 40 is a piston. A cam 48 opens and closes the intake and exhaust valves 39 and 41 via a rocker arm 49.

  The exhaust gas combusted in the cylinder 5 passes through the exhaust manifold 42 from the exhaust valve 41 and is then discharged by driving the supercharger TB with the exhaust turbine 45 of the supercharger TB.

  The diesel engine has an EGR (exhaust gas recirculation device) circuit 44 for mixing a part of the exhaust gas into the intake side. In the EGR circuit, a part of the exhaust gas is mixed into the intake side to reduce the amount of oxygen (O2), thereby reducing the generation of nitrogen oxide Nox. However, if the EGR rate increases too much, the amount of oxygen decreases and incomplete combustion occurs. Therefore, it is necessary to adjust the EGR rate according to the combustion state. This adjustment is performed by the EGR valve 43. The EGR circuit 44 connects between an exhaust pipe 55 on the downstream side of a post-processing device 46 described later and an intake pipe 56 on the upstream side of the intake turbine 36 of the supercharger TB. In addition, an EGR cooler 57 is provided in the middle of the EGR circuit 44. The amount of exhaust gas reduced into the cylinder 5 varies depending on how the EGR valve 43 is opened and closed.

  The exhaust gas that has passed through the exhaust turbine 45 passes through the aftertreatment device 46 and is discharged from the muffler 50 into the atmosphere. The post-processing device 46 includes an oxidation catalyst (DOC) 46a and a diesel particulate filter (DPF) 46b.

  The oxidation catalyst (DOC) burns the incombustible chamber, and the diesel particulate filter (DPF) is for collecting the particulate matter (PM). The EGR valve 43 and the throttle valve 47 are controlled by the ECU 100. The post-processing device 46 may be composed of only a diesel particulate filter (DPF) 46b. If an oxidation catalyst (DOC) is provided, the non-combustible material burns, resulting in cleaner exhaust gas.

  When the state of the exhaust gas is low (low load) continues for a long time, the DPF 46b has a concern that PM will accumulate and the capacity may be reduced. Therefore, a throttle valve 47 is provided on the lower side of the post-processing device 46, and when the throttle valve 47 is throttled, the pressure in the DPF 46b is kept high, so the temperature also rises. This makes it possible to regenerate the DPF 46b due to the influence of a high temperature. That is, when exhaust gas having a high temperature passes through the DPF 46b, the DPF 46b is regenerated by burning off the PM present in the DPF 46b.

  In the DPF regeneration operation for regenerating the DPF 46b, both the EGR valve 43 and the throttle valve 47 are throttled. Then, the gas temperature in the DPF 46b is raised together with the retard (retard) of the fuel injection timing so that the DPF 46b starts to be regenerated. This eliminates the need for fuel after-injection (in order to increase the exhaust gas temperature) or reduces the number of after-injections, so that the amount of fuel consumption can be suppressed and the environment is good.

  As a condition for performing such a DPF regeneration operation, the pressure sensor 52 is provided on the upper side of the post-processing device 46, the pressure sensor 53 is provided on the lower side of the post-processing device 46, and this pressure difference is a predetermined value or more. Then, since PM accumulates in the DPF 46b and becomes a resistance, the DPF regeneration operation is performed. Moreover, it is good also as a structure which provides the pressure sensor 58 between DOC46a and DPF46b instead of the pressure sensor 52. FIG.

  Further, if the state in which the DPF regeneration operation is started continues for a long time, the DPF 46b is damaged due to an overheating state. Therefore, a temperature sensor 59 is provided on the lower side of the post-processing device 46, and when the value of the temperature sensor 59 exceeds a predetermined value, the DPF regeneration operation is stopped and the normal operation is resumed.

  In normal operation, the EGR valve 43 and the throttle valve 47 are simultaneously controlled to appropriately control the EGR amount. In particular, by having the throttle valve 47, the gas temperature in the DPF 46b can be kept high.

  With the configuration as described above, an intake throttle is not required. In other words, since the intake side pressure is high in an engine with a supercharger, an exhaust throttle valve or an intake throttle is required to secure the amount of EGR gas, and control in conjunction with the EGR valve is required, but such a system is unnecessary. It becomes.

  Further, since the exhaust gas downstream of the DPF 46b is taken out, it is possible to prevent the performance deterioration caused by the dirt of the supercharger TB. And since EGR gas is cooled by the EGR cooler 57, an effect becomes large with respect to NOx reduction.

  As described above, in the DPF forced regeneration mode in which the regeneration operation of the DPF is performed, the exhaust throttle valve 47 is throttled and the EGR valve 43 is fully closed by ON-OFF control. Therefore, NO is increased because the exhaust gas is not reduced, and this NO is converted to NO2 by the oxidation catalyst (DOC) 46a, and regeneration of the DPF 46b is promoted.

  Further, when the engine rotation shifts to low idle during the forced regeneration of the DPF 46b, the EGR valve 43 is fully opened. Since the temperature sensor 59 is provided on the downstream side of the DPF 46b, it may be added to the condition that the detection value by the temperature sensor 59 has risen to a predetermined value or more.

  When the DPF 46b is forcibly regenerated by restricting the throttle valve 47, the engine speed is reduced to increase the supply oxygen amount, and the exhaust gas flow rate is decreased to increase the temperature easily. However, when the engine speed is changed to low idle or in the vicinity thereof during regeneration, soot burns rapidly due to an increase in the amount of supplied oxygen and a decrease in the flow velocity. As a result, the temperature may rise rapidly and the DPF 46b may be damaged. Therefore, it is necessary to manage the soot that the maximum temperature does not exceed the allowable temperature.

  For this reason, when the temperature sensor 59 exceeds a predetermined value, the engine speed is increased to a medium speed range. As a result, the flow rate of the exhaust gas is increased, so that the maximum temperature is lowered and damage to the DPF 46b can be prevented. Further, when the predetermined value of the temperature sensor 59 is controlled in the vicinity of the limit value, the DPF 46b can be efficiently regenerated.

  In order to increase the engine speed to the middle speed range, it may be configured to once increase to the maximum speed and then decelerate to the middle speed range, so that the exhaust gas once flows at the maximum speed. For example, it is possible to prevent the DPF 46b from being heated and exceeding the threshold temperature.

  Further, during the forced regeneration of the DPF 46b, when the engine speed is shifted to low idle as described above, the post-injection is interrupted, and then the engine speed is increased to the maximum speed and shifted to the medium speed range. Then, post-injection is resumed. Thereby, since the rapid rise in the exhaust gas temperature can be suppressed, damage to the DPF 46b can be prevented.

  When the differential pressure before and after the DPF 46b exceeds a predetermined value, the driver selects the regeneration mode of the DPF 46b after the work so that the DPF 46b is automatically regenerated, and the engine is automatically stopped after the DPF 46b is regenerated. To do. The differential pressure across the DPF 46b is monitored by pressure sensors 58 and 53. If the differential pressure across the DPF 46b immediately before the engine stops is equal to or greater than a predetermined value, a warning lamp or alarm notifies the driver, and the driver operates a switch (not shown) for regenerating the DPF 46b.

  Even when the engine key is in the cut position, since the regeneration mode is selected, the engine keeps rotating in the idling state and performs regeneration of the DPF 46b. When the differential pressure before and after the DPF 46b falls below a predetermined value, the engine is automatically stopped.

  Thus, even after the work is completed, the DPF 46b can be automatically regenerated and the engine can be stopped, so that the driver can leave the machine and perform other work.

  An air-fuel ratio sensor 63 is provided on the downstream side of the DPF 46b. When the post-injection is performed to regenerate the DPF 46b, if the fuel injection amount is too large, the fuel consumption is deteriorated. If the fuel injection amount is small, the temperature does not increase and the regeneration cannot be performed. Therefore, the injection amount is determined by feeding back the value of the air-fuel ratio sensor 63 to the ECU 100. As a result, the fuel consumption becomes appropriate and the DPF 46b can be regenerated. Further, instead of the air-fuel ratio sensor 63, a pressure value in the intake manifold may be fed back.

  When regenerating the DPF 46b as described above, in the case of a plurality of cylinders, the combustion of some cylinders may be stopped. Thus, by stopping the combustion of some cylinders, the exhaust temperature may be increased by increasing the load per cylinder even if the engine friction is the same.

  And as shown in FIG. 7, when the low fuel consumption mode line L2 mentioned above is performed, it is set as the structure which checks automatic regeneration of DPF46b. In the low fuel consumption mode, the engine output is low and the exhaust temperature is low, so that there is a problem that the regeneration efficiency is low. Since the automatic regeneration of the post-processing device is performed only when the standard mode line L1 with a high exhaust temperature is being executed, the regeneration efficiency is improved and the fuel consumption can be reduced by regeneration.

  As shown in FIG. 8, when the coolant temperature is lower than the threshold, the fuel efficiency mode line L2 is automatically selected to advance the fuel injection timing. Thereby, misfire etc. at the time of low temperature can be prevented and the discharge | emission amount of granulated substance PM can be reduced. By displaying such a situation on the monitor M, the operator can easily grasp the situation of the engine.

  Also, as shown in FIG. 9, when the engine speed is lower than the threshold value, the standard mode line L1 is automatically executed to improve the torque, thereby reducing the engine speed fluctuation and speeding up the engine speed recovery. Will be able to.

  A configuration using the above-described EGR circuit 44 of FIG. 6 will be described. A low PM discharge mode change-over switch (not shown) that reduces PM (granulated material) discharge is provided at any position on the machine. When this switch is turned on, the output is 20% higher than the standard mode line L1. The control is performed with a low PM discharge mode line (not shown) limited by about 40%, and the EGR valve 43 is further throttled to control the EGR rate by half. The low PM emission mode line is different from the low fuel consumption mode line L2. If the injection conditions are the same, the PM emission amount decreases as the EGR rate decreases.

  By configuring in this way, a high load range with a large amount of NOx emission can be cut, so even if the EGR rate is lowered, the NOx emission amount per unit output does not change and the PM emission amount can be lowered.

  As shown in FIG. 10A, when the opening degree of the EGR valve 43 is controlled so that the EGR rate decreases as the output increases, the output increases in the standard mode L3 as shown in FIG. 10B. As a result, the NOx emission increases in a quadratic curve. The low fuel consumption mode is advanced by 2 to 4 degrees with respect to the standard mode. However, since the output is limited by reducing the total load injection amount, the entire fuel consumption mode is larger than the NOx emission curve L3 of the base standard mode. Even if it shifts to the larger side, the NOx emission amount per output is the same in all of the reference emission line, the standard mode, and the low fuel consumption mode. When viewed at the same load, the fuel consumption in the low fuel consumption mode is better than that in the standard mode.

  As described above, the EGR rate of each rotation is gradually decreased with the quadratic curve as the output increases so that the NOx emission amount in each rotation increases with the quadratic curve with respect to the output. And the low fuel consumption mode which reduced the full load injection quantity and advanced the injection timing 2 to 4 degree | times is set. Each mode can be switched arbitrarily with a changeover switch. Therefore, at each rotation, the EGR rate decreases as the output increases, so that the NOx emission amount can be increased in a quadratic curve as the output increases. With this NOx emission characteristic, the fuel consumption can be improved without increasing the NOx emission amount per output by advancing the injection timing and reducing the total load injection amount.

  FIG. 11 shows a configuration in which a power mode line L5 is provided. The power mode is switched by a switch (not shown). When the switch is turned on, the opening degree of the EGR valve 43 is set to 0% (fully closed) only in the rated rotation high load range, and the output (fuel injection amount) outside the rated rotation range is limited.

  When the EGR rate is lowered, the amount of intake air increases, and the fuel efficiency improves. In particular, in the high load range, the air-fuel ratio is small (the amount of air relative to the fuel is small), and therefore, the influence of the change in the intake air amount on the fuel efficiency is greater than in the light and medium load range.

  By setting the EGR rate in the high load range to 0%, the output increases without increasing the injection amount. On the other hand, if the EGR rate is reduced, the NOx emission amount increases, so the output in the high load region below the middle rotation is lowered to reduce the NOx emission amount.

  Thereby, with respect to the standard output curve L1, it becomes the power mode line L5 in which the output below the middle rotation is low and the high rotation output is high. Therefore, the driver can select an output curve having a low rated output but a large torque rise and an output curve having a high rated rotation but a small torque rise depending on the work situation.

  FIG. 12 shows a plowing depth adjustment dial 68 that determines the plowing depth of the work machine (rotary work machine) 21. The scale 1 is in a shallow state and becomes deeper as the scale 8 is reached. The post-processing device (DPF 46b) is not automatically regenerated at a predetermined depth (scale 4) or less, and the DPF 46b is automatically regenerated at the scale 5 or more. As described above, since the post-treatment device is automatically regenerated only when the plowing depth is equal to or greater than a certain depth (large load) and the exhaust temperature is high, efficient regeneration is possible.

  In the type in which the rotational speed of the rotary work machine 21 can be changed, it is configured to determine whether or not the automatic regeneration of the DPF 41b is performed according to the number of shift stages. For example, automatic regeneration may not be performed at a low gear number (1st speed, 2nd gear), and automatic regeneration may be performed at a higher gear speed (3rd speed, 4th gear).

  Alternatively, the DPF 46b may be automatically regenerated when an air conditioner switch (not shown) in the cabin 14 is turned on. This is because the exhaust temperature rises due to the load acting on the engine because the compressor is driven when the air conditioner is driven.

  Reference numerals 69 and 70 shown in FIG. 6 will be described. Reference numeral 69 is a fuel injection nozzle, and reference numeral 70 is a pump. The pump 70 is controlled by the ECU 100. During regeneration of the DPF 46b, fuel is injected from the fuel injection nozzle 69 to raise the exhaust temperature. The exhaust temperature is raised to about 650 degrees on the rear side of the DPF 46b. As a result, the PM in the DPF 46b is burned off and the DPF 46b is regenerated.

  FIG. 13 shows an embodiment in which the DPF 46b is disposed in the engine room 71. However, since the DPF 46b is heated, the auxiliary devices in the engine room 71 are affected. Therefore, the cooling air outlet 72 in the cabin 14 is provided in the engine room 71. Thereby, it becomes possible to suppress an extreme temperature rise of auxiliary devices, resins, wirings and the like in the engine room 71, and protection is possible.

  FIG. 14 shows that the compressor 73 mounted on the fuselage is driven by the drive shaft 74 forward of the engine E (front PTO shaft in the case of a tractor) to apply a load to the engine (exhaust temperature rise) and regenerate the DPF 46b. (Automatic, manual). Further, by opening the valve 75 and supplying oxygen to the front of the DPF 46b, combustion is promoted and the regeneration efficiency is improved.

  FIG. 15 shows a configuration in which the DPF 46b is mounted above the engine E. A frame 76 is provided upright on the outer periphery of the engine E from the vehicle body frame 78, a hanging tool 77 is provided on the frame 76, and a DPF 46 b is provided on the hanging tool 77. As a result, the DPF 46b can be mounted with a simple configuration.

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

1 Common rail 46b DPF
100 ECU
E Engine L1 Standard mode line L2 Low fuel consumption mode line M Monitor PM Granulated material

Claims (3)

  In the work vehicle in which the ECU (100) performs various controls of the engine (E), a DPF (46b) for removing the particulate matter (PM) in the exhaust gas is provided, and the ECU (100) includes an engine speed and A performance curve indicating a relationship with torque is composed of at least a standard mode line (L1) and a low fuel consumption mode line (L2), and when the low fuel consumption mode line (L2) is executed, the DPF (46b) A work vehicle that is configured not to be regenerated.   2. The engine according to claim 1, wherein when the coolant temperature of the engine (E) is lower than a predetermined value, the fuel efficiency mode line (L2) is automatically selected and the fuel injection timing is advanced. The work vehicle described.   When the DPF (46b) is not regenerated, or when the fuel-efficient mode line (L2) is automatically selected and the fuel injection timing is advanced, the DPF (46b) is displayed on the monitor (M). The work vehicle according to claim 1, wherein the work vehicle is a vehicle.

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