JP2023096960A - Working vehicle - Google Patents

Abstract

To prevent a flammable substance from catching a fire at the forcible regeneration of a diesel particulate filter, and to protect an engine control unit from a thermal influence.SOLUTION: In a working vehicle having a diesel particulate filter 46b for collecting particulate substances PM in an exhaust gas, when an accumulation quantity of the particulate substances PM in the diesel particulate filter 46b reaches a prescribed value or larger, forcible regeneration for reducing the PM accumulation quantity in the diesel particulate filter 46b is performed, and before a prescribed time at which the forcible regeneration is performed, a notification for promoting the manual regeneration of the diesel particulate filter 46b is provided by notification means.SELECTED DRAWING: Figure 6

Description

The present invention relates to a work vehicle equipped with a diesel particulate filter that removes particulate matter (PM) in exhaust gas emitted from a diesel engine.

A technology of forced regeneration means for forcibly burning and removing PM trapped in a diesel particulate filter to regenerate the diesel particulate filter has been disclosed (see, for example, Patent Document 1).

JP 2009-19534 A

In the above-described technology, the start of regeneration is notified after the start of forced regeneration.

SUMMARY OF THE INVENTION An object of the present invention is to provide a work vehicle that eliminates the problems described above.

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

That is, in the invention according to claim 1, in a work vehicle equipped with a diesel particulate filter (46b) for collecting particulate matter (PM) in exhaust gas, the particulate matter in the diesel particulate filter (46b) When the (PM) accumulation amount exceeds a predetermined value, forced regeneration is performed to reduce the PM accumulation amount in the diesel particulate filter (46b), and a notification means notifies a predetermined time before the forced regeneration is performed. The work vehicle is characterized in that it is configured as follows.

In the invention according to claim 2, in the working vehicle provided with the diesel particulate filter (46b) for collecting particulate matter (PM) in the exhaust gas, the particulate matter (PM) in the diesel particulate filter (46b) ) becomes a predetermined value or more, the diesel particulate filter (46b) is configured to perform forced regeneration to reduce the PM deposition amount, and the engine is operated regardless of the PM deposition amount in the diesel particulate filter (46b). The work vehicle is characterized in that, when the integrated time reaches a predetermined time, a notification means is provided to notify the user to prompt manual regeneration of the diesel particulate filter (46b).

In the invention according to claim 3, the work vehicle according to claim 2 is characterized in that the conditions for manual regeneration are displayed on the display means when the notifying means performs notification to prompt the manual regeneration. It is what I did.

Since the present invention is constructed as described above, in the invention according to claim 1, it is possible to know in advance that forced regeneration of the diesel particulate filter (46b) will start. can be done.

In the second aspect of the invention, manual regeneration of the diesel particulate filter (46b) is urged when the accumulated engine running time reaches the predetermined time regardless of the amount of PM accumulated in the diesel particulate filter (46b). performance can be properly maintained.

In the third aspect of the invention, in addition to the effect of the second aspect, the conditions for manual regeneration can be quickly known, and manual regeneration can be performed efficiently.

Overall configuration diagram of an accumulator fuel injection system Diagram showing relationship between engine speed and output torque depending on control mode Left side view of tractor Top view of tractor Schematic diagram of intake system and exhaust system DPF regeneration flow chart front view of display screen Schematic diagram near the EGR cooler Connection sectional view of EGR valve and intake manifold Connection sectional view of EGR valve and intake manifold Connection sectional view of EGR valve and intake manifold Sectional view of turbocharger inlet Engine performance chart Flowchart at engine start Layout plan of DPF and resonator Cross section of DPF and resonator DPF regeneration flow chart Common rail pressure switching flow chart Fuel injection flow chart Cross section of air cleaner Cross section of air cleaner Cross section of air cleaner EGR valve operation flow chart EGR valve operation flow chart EGR valve operation flow chart Cross-sectional schematic diagram of DOC and DPF

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

FIG. 1 is an overall configuration diagram of an accumulator fuel injection system. The accumulator fuel injection device is applied, for example, to a multi-cylinder diesel engine, but may be applied to a gasoline engine or other internal combustion engines. The accumulator type fuel injection device includes a common rail 1 for accumulating high-pressure fuel corresponding to the injection pressure, a pressure sensor 2 attached to the common rail 1, and a fuel tank 3 for pressurizing the fuel drawn up from the fuel tank 3 and forcing it to the common rail 1. A high-pressure pump 4, a fuel injection nozzle 6 for injecting the 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 and the fuel injection nozzle 6, etc. consists of ECU is an abbreviation for engine control unit.

Thus, the common rail 1 injects fuel into each cylinder 5 of the engine E to bring the fuel supply to the 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 intake passage. He is stored.

The high-pressure fuel in the common rail 1 is supplied to the fuel injection nozzles 6 corresponding to the number of cylinders through each high-pressure fuel supply passage 9, and the fuel injection nozzles 6 are operated in each cylinder based on the command from the engine control unit (hereinafter referred to as ECU 100). Then, high-pressure fuel is injected into each chamber 5 of the engine E, and surplus fuel (return fuel) at each fuel injection nozzle 6 is led to a common return passage 10 by each return passage 10. is returned to the fuel tank 3 by .

A pressure control valve 11 is provided in the high pressure pump 4 to control the fuel pressure in the common rail 1 (common rail pressure). By adjusting the passage area of the return passage 10 for the surplus fuel to the common rail 1, it is possible to control the common rail pressure by adjusting the amount of fuel discharged to the common rail 1 side.

Specifically, a target common rail pressure is set according to engine operating conditions, and the common rail pressure is feedback-controlled via 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, an ECU 100 of a diesel engine E having a common rail 1 in a work vehicle (agricultural work machine) operates in three modes, a travel mode A, a normal work mode B, and a heavy work mode C, in terms of the relationship between the rotation speed and the output torque. It is configured to have a control mode.

Driving mode A is a droop control in which the output fluctuates as the engine speed fluctuates. It is used when traveling without doing farm work. For example, when the running speed is decelerated or stopped by applying the brakes, the engine speed decreases as the running load increases, so the running speed can be decelerated or stopped safely.

The normal work mode B is isochronous control in which the engine speed is constant even if the load fluctuates and the output is changed according to the load. It is used for normal farm work. For example, in the case of a tractor, resistance is applied to the plowing blade when the land is hard during plowing work, and in the case of a combine harvester, output fluctuates and the number of rotations is maintained even when the load increases due to the large amount of harvested material during harvesting work. It is time.

Heavy work mode C is similar to normal work mode B. In addition to isochronous control that changes the output according to the load at a constant engine speed even if the load fluctuates, when the load approaches the limit, the speed is increased and the output is increased. This is a control with heavy load control that raises In particular, it is used when agricultural work is performed near the load limit. For example, when plowing with a tractor, even if a particularly hard field is encountered, the engine output increases beyond the normal limit, enabling efficient work without interrupting the work. .

These work modes A, B, and C are operated by operating a work mode selector switch that can switch between the work modes A, B, and C, or by operating a travel gear shift lever of an agricultural vehicle (tractor, combine, rice transplanter, etc.), Alternatively, it is configured to be switched by on/off operation of a work clutch (rotary in the case of a tractor, and reaping section and threshing section in the case of a combine harvester).

In the diesel engine E, by performing pilot injection in which a small amount of fuel is injected in a pulsed manner prior to the main injection, it is possible to shorten the ignition delay, reduce the knocking sound peculiar to the diesel engine E, and reduce noise. configuration.

This pilot injection was performed only once or twice before the main injection. By changing the state of , it is possible to reduce noise and suppress the generation of white smoke or black smoke due to incomplete combustion. Further, by performing a pilot injection in which a small amount of fuel is pulse-injected prior to the 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 a common rail 1 as described above, and FIG. 4 shows a plan view thereof. The plan view shows a state in which the cabin 14 shown in FIG. 3 is omitted.

The tractor has front wheels 12, 12 and rear wheels 13, 13 at the front and rear parts of the body. , 12 and rear wheels 13, 13.

A steering handle 16 is supported on a handle post 15 in the cabin 14 at the center of the aircraft body, and a seat 17 is provided behind it. Below the steering handle 16, a forward/reverse lever 18 is provided for switching the direction of travel of the machine body to the forward/rearward direction. When the forward/reverse lever 18 is moved forward, the fuselage moves forward, and when it is moved backward, the fuselage moves backward.

An accelerator lever 25 for adjusting the engine speed is provided on the opposite side of the forward/reverse lever 18 across the handle post 15, and an accelerator for adjusting the engine speed is provided at the right corner of the step floor 19. A pedal 23 and left and right brake pedals 24L and 24R for applying brakes to the left and right rear wheels 13 and 13 are provided. A clutch pedal 20 is provided at the left corner of the step floor 19 .

A main gearshift lever 26 is located in front of the left side of the seat 17, an auxiliary gearshift lever 27 which can select any of low speed, medium speed, high speed and neutral position is located behind it, and a PTO gearshift lever 28 is located on the right side thereof. is provided. Further, on the right side of the seat 17, a position lever 29 for setting the height of the working machine 21 (such as a rotary) and an automatic plowing depth lever 30 for automatically setting the plowing depth of the field. A right raising switch 31 and a right lowering switch 32 are arranged, and an automatic leveling switch 33 and a backup switch 34 of the working machine 21 are further arranged after that. The backup switch 34 automatically raises the work implement 21 when the machine body moves backward. The working machine 21 is configured to be connected to the rear of the machine body by a link 22 . The tractor performs work such as plowing in a field by driving the working machine 21 to make the machine body travel. A hydraulic cylinder 21a moves the work machine 21 up and down.

FIG. 5 is a schematic diagram of the intake and exhaust into the cylinder 5 of the engine, which is an example of a four-cycle diesel engine. The air supercharged by the intake turbine 36 of the supercharger TB passes from the air cleaner 35 through the intake turbine 36 and the intercooler 37 and is sent from the intake manifold 38 into the cylinder 5 . 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 .

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

This diesel engine has an EGR (exhaust gas recirculation device) circuit 44 for mixing part of the exhaust gas into the intake side. By returning part of the exhaust gas to the intake side, the combustion temperature is lowered and the emission of NOx in the exhaust gas is suppressed. Since there is little oxygen in the exhaust gas, fuel injection is suppressed accordingly, reducing NOx.

In this manner, the EGR circuit is configured to reduce the amount of oxygen (O2) by mixing part of the exhaust gas into the intake side, thereby reducing the generation of nitrogen oxides Nox. However, if the EGR rate rises too much, the amount of oxygen will decrease, resulting in incomplete combustion. 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 an aftertreatment device 46 and an intake pipe 56 on the upstream side of the intake turbine 36 of the supercharger TB. Also, an EGR cooler 57 is provided in the middle of the EGR circuit 44 . The amount of exhaust gas returned to the cylinder 5 changes depending on how the EGR valve 43 is opened or closed.

After passing through the exhaust turbine 45, the exhaust gas passes through the aftertreatment device 46 and is discharged from the muffler 50 into the atmosphere. The aftertreatment device 46 is composed of 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) collects the particulate matter chamber (PM). The EGR valve 43 and throttle valve 47 are configured to be controlled by the ECU 100 . The post-treatment device 46 may be composed only of a diesel particulate filter (DPF) 46b. If an oxidation catalyst (DOC) is provided, incombustible substances are burned, resulting in cleaner exhaust gas.

If the temperature of the exhaust gas is low (low load) continues for a long period of time, the DPF 46b is likely to be deteriorated due to accumulation of PM. Therefore, if a throttle valve 47 is provided on the downstream side of the post-processing device 46 and the throttle valve 47 is throttled, the pressure in the DPF 46b is kept high and the temperature also rises. Thereby, regeneration of the DPF 46b becomes possible due to the influence of the high temperature. That is, when high-temperature exhaust gas passes through the DPF 46b, the DPF 46b is regenerated by burning off the PM present in the DPF 46b.

As the DPF regeneration operation for regenerating the DPF 46b, both the EGR valve 43 and the throttle valve 47 are throttled. Together with retarding the fuel injection timing, the gas temperature in the DPF 46b is increased so that the DPF 46b enters regeneration. This eliminates the need for after-injection of fuel (to raise the temperature of the exhaust gas) and reduces the number of times of after-injection, which reduces fuel consumption and is good for the environment.

As a condition for performing such a DPF regeneration operation, a pressure sensor 52 is provided on the upstream side of the aftertreatment device 46, and when the value of this pressure sensor 52 exceeds a predetermined value, PM accumulates in the DPF 46b. Therefore, the DPF regeneration operation is performed.

Further, if the DPF regeneration operation continues for a long time, the DPF 46b will be damaged due to overheating. Therefore, a temperature sensor 53 is provided downstream of the aftertreatment device 46, and when the value of this temperature sensor 53 exceeds a predetermined value, the DPF regeneration operation is stopped and normal operation is resumed.

In normal operation, the EGR valve 43 and 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.

By adopting the configuration as described above, an intake throttle becomes unnecessary. That is, since the intake side pressure is high in an engine with a supercharger, an exhaust throttle valve or an intake throttle is provided to secure the amount of EGR gas, and control in conjunction with the EGR valve is required, but such a system is unnecessary. becomes.

In addition, since the exhaust gas is taken out downstream of the DPF 46b, it is possible to prevent the performance from deteriorating due to dirt on the supercharger TB. Since the EGR gas is cooled by the EGR cooler 57, the effect of reducing NOx is increased.

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

Further, when the engine speed shifts to low idle during forced regeneration of the DPF 46b, the EGR valve 43 is fully opened. Since the temperature sensor 53 is provided on the downstream side of the DPF 46b, the fact that the detected value by the temperature sensor 53 has risen above a predetermined value may be added to the condition.

When manual regeneration of the DPF 46b becomes necessary, the engine speed and output are reduced. Then, at this time, a configuration is adopted in which a buzzer, a lamp, or the like is used to notify the user. Furthermore, when the amount of PM in the DPF 46b approaches 100% and emergency manual regeneration is required, the speed is reduced. Moreover, it is configured such that the drive of the working machine such as the PTO is stopped. In case of emergency, the configuration as described above enables regeneration without damaging the DPF. In addition, in case of emergency, the mobile terminal is configured to be notified, and furthermore, the manual regeneration operation procedure is displayed on the mobile terminal, so that the manual regeneration can be performed reliably.

FIG. 6 shows a flow chart during regeneration of the DPF 46b.

In Step B, the condition for automatic regeneration is satisfied, but when about 10 minutes before automatic regeneration is recognized in Step A, which is a predetermined time (about 10 minutes before) of this Step B, the notifying means is activated in Step A1, and automatic regeneration is performed. will start soon. As a result, it is possible to know in advance that high-temperature exhaust gas will be discharged, so that it is possible to prevent igniting combustibles.

Regardless of whether automatic regeneration is executed or not and the number of times of automatic regeneration, Step C is configured to forcibly satisfy the manual regeneration condition. Specifically, when a predetermined time (50 hours) has elapsed from the start of operation, the manual regeneration flag is established. The aforementioned time from the start of operation is determined by the displacement of the engine and the capacity of the DPF. As a result, the performance of the DPF can be properly maintained.

FIG. 7 shows manual regeneration conditions. A monitor screen 15a attached to a handle post 15 is configured to display regeneration conditions during manual regeneration. For example, if the parking brake is not operating, a display prompting the user to apply the parking brake is displayed. This enables efficient manual regeneration.

In FIG. 8, in order to prevent overcooling by the EGR cooler 57, a thermostat 60 is provided in the cooling water pipe 58 on the upstream side of the EGR cooler 57, and when the cooling water temperature drops below a predetermined value, the cooling water flow is cut off. . A reference numeral 59 denotes a downstream cooling water pipe of the EGR cooler 57 . Reference numeral 61 denotes a bypass line that connects the upstream side cooling water line 58 and the downstream side cooling water line 59 of the EGR cooler 57 . When the thermostat 60 interrupts the flow of cooling water, the cooling water passes through the bypass pipe 61 and flows into the downstream cooling water pipe 59 . This can prevent excessive water pressure from acting on the pipeline.

A temperature sensor 62 is provided in the upstream cooling water pipe 58, and when the water temperature exceeds a predetermined value, an alarm is issued to stop the engine. As a result, it is possible to prevent dry-heating operation when the amount of cooling water is abnormally low.

FIG. 9 shows a cross-sectional view from the EGR valve 43 to the intake manifold 63. As shown in FIG. At the inlet portion of the intake manifold 63, a plurality of gaskets (in this embodiment, two gaskets, numerals 64 and 65) are provided. A hole 64a is formed in the gasket 64 on the upstream side, and a hole 65a is formed in the gasket 65 on the downstream side. The holes 64a on the upstream side and the holes 65a on the downstream side are not concentric but offset.

As a result, the exhaust gas that is returned from the exhaust side to the intake side flows meanderingly, so that the soot in the exhaust gas falls and is removed to some extent. FIG. 10 shows another configuration of the gasket. In forming the hole 66a of the gasket 66, a raised portion 66b is formed toward the downstream side, and the exit diameter 66c of the hole 66a of the gasket 66 is formed smaller than the exit diameter 43a of the EGR valve 43. 11 also shows another configuration of the gasket 67. FIG. The protrusion 67a of the gasket 67 overlaps the outlet end 43b of the EGR valve 43 and enters the EGR valve 43 side.

In FIG. 12, a gasket 68 is provided at the inlet of the supercharger TB and bent at a bent portion 68a. As a result, the flow velocity of the exhaust gas toward the supercharger TB is increased, and the rotational efficiency of the supercharger TB is improved.

FIG. 13 shows performance lines of the engine. Normally, there is only the 100% line L1, but it has a 90% line L2, an 80% line L3, and a 75% line L4. In the fuel injection amount of the engine, the average injection amount in the latest specified time is calculated, and the optimum line is automatically selected from the lines L1 to L4 according to the average injection amount. Since the smaller the average injection amount, the smaller the engine load, the smaller the engine load, the more the line L4 is changed. This makes it possible to prevent excessive fuel injection. Further, the line selected automatically from the lines L1 to L4 is displayed on the display unit.

As shown in FIG. 5, an air flow sensor 69 is provided on the downstream side of the air cleaner 35 to measure the amount of intake air and perform fuel injection control and other controls. When the engine speed is below a predetermined speed, the measured value of the airflow sensor 69 is used. The theoretical intake air amount calculated from the concentration is used. When the engine speed is high, the air pulsates on the downstream side of the air cleaner 35 and the measured value of the air flow sensor becomes unstable. Since the intake air amount can be calculated accurately, it is possible to accurately perform DPF regeneration control and EGR valve control.

Further, a plurality of air flow sensors 69 may be provided, and the measurement result without pulsation among the measurement values may be used, or the measurement result with the least pulsation may be used.

Alternatively, the intake air amount may be measured from the differential pressure across the air cleaner 35, the engine speed, the fuel injection amount, and the atmospheric pressure. In this case, since the air flow sensor 69 does not have to be used, the construction is inexpensive.

As described above, when measuring the intake air amount using the measured value of the air flow sensor 69, the first calculation means J1 is used, and the air flow sensor is not used, and the theoretical value is calculated from the engine speed, the atmospheric pressure, and the oxygen concentration from the lambda sensor. The case of calculating the intake air amount is referred to as second calculating means J2. During the regeneration of the DPF 46b, the first calculation means J1 is normally used, and when the exhaust gas temperature does not rise to the reference value and regeneration progresses poorly, the second calculation means J2 is used.

As a result, the DPF can be stably regenerated even when the air flow sensor 69 has a characteristic deviation (such as pulsation).

In addition, in the manual regeneration of the DPF, after the engine speed rises, the air flow rate calculated by the first calculation means J1 is compared with the reference value. It is configured to perform playback. This enables stable regeneration of the DPF. Further, when the air flow rate by the first calculating means J1 is compared with the reference value after the engine speed is increased, the engine speed is set to be higher than the engine speed during manual regeneration during this comparison. As a result, the regeneration of the DPF can be stably performed, and the judgment can be made more accurately by increasing the engine speed. Further, the engine speed is increased during DPF regeneration, and the first calculation means is used during the period in which the engine speed is increased. When the air flow rate is outside the reference flow rate, the DPF is regenerated with the air flow rate calculated by the second calculating means. This makes it possible to stably regenerate the DPF.

FIG. 14 shows a flow chart from power-on to engine start-up. The starter motor starts rotating in Step D, and after a predetermined time (two seconds in this embodiment), fuel supply is started (Step E). Since the air is compressed by the piston during these 2 seconds, the inside of the cylinder chamber is warmed by the heat of compression. Smell can be suppressed. Further, the fuel supply may be turned on and off during the time from StepD to StepE. This fuel supply may be switched on and off once or a plurality of times. By instantaneously injecting the fuel in this way, the ignition quality is improved.

In the above-described ECU 100 (FIG. 5) for controlling the engine, the EGR valve 43 is forcibly closed when the ECU 100 fails and becomes uncontrollable and the engine rotation starts to run out of control. As a result, damage to the EGR valve 43 and the EGR cooler 57 can be prevented. Further, when the ECU 100 fails and becomes uncontrollable and the engine rotation starts to run out of control, the EGR valve 43 is fully opened when the amount of PM accumulated in the DPF 46b is equal to or greater than a predetermined value. As a result, the concentration of carbon dioxide in the intake air and the exhaust gas increases, so that unintended regeneration of the DPF can be suppressed.

In addition, when the ECU 100 fails and becomes uncontrollable and the engine rotation starts to run out of control, the intake throttle valve 70 (FIG. 5) that adjusts the intake air amount is operated to the closing side, and the air equivalent to the rotation of the low idle ring is operated. It is configured to close up to the amount. The air flow sensor 69 is used for determining the air flow. As a result, the rotation of the engine is suppressed, and the working machine and the hydraulic equipment can be stopped safely. FIG. 15 shows a configuration in which a resonator 71 and an intake pipe 72 for preventing intake vibration are integrated. Reference numeral 73 is an intake manifold, reference numeral 74 is an exhaust manifold, and reference numeral 46b is a DPF. FIG. 16 shows a cross-sectional view of the intake pipe 72, resonator 71, and DPF 46b. A space for the resonator 71 is provided between the DPF 46b and the intake pipe 72 to form a heat insulating structure. As a result, the air flowing through the intake pipe 72 is less likely to be affected by the heat of the DPF 46b, and a decrease in output due to an increase in intake air temperature can be suppressed.

FIG. 17 is a flow chart regarding the regeneration temperature of the DPF. A structure in which the target regeneration temperature of the DPF is temporarily lowered by a predetermined temperature (100 degrees in this embodiment) when the vehicle is stopped while traveling on the road, and the control target regeneration temperature is returned to the original value when the vehicle can be started again. and As a result, when the vehicle is stopped while the DPF is being regenerated during running, the post-injection amount is suppressed by lowering the DPF regeneration target temperature, thereby improving the fuel efficiency.

FIG. 18 shows a flowchart relating to noise reduction during acceleration. When the change in the degree of opening of the accelerator is large, or when the vehicle speed increases with the degree of opening of the accelerator being 100%, the common rail pressure is reduced to the value of 80%. This reduces diesel knock noise.

FIG. 19 shows a flowchart of injector abnormality diagnosis. If there is a large discrepancy in the correlation between the current fuel injection amount and oxygen concentration compared to the appropriate correlation between the oxygen concentration detected by the lambda sensor and the fuel injection amount, the injector is determined to be abnormal and inspected. It is configured to issue a warning prompting As a result, an abnormality in the fuel injection system and abnormal combustion in the cylinder chamber can be prevented.

FIG. 20 shows a cross-sectional view of the air cleaner 35. As shown in FIG. At the outlet of the air cleaner 35, an air flow sensor 69 for measuring the intake air amount is provided. The case itself of the air cleaner 35 has a double element specification, and if only the cylindrical element 76 is actually used, turbulence will occur when the air leaves the air cleaner. Therefore, the rectifier 77 is provided at the second element mounting portion of the air cleaner 35 and at the exit portion of the air cleaner 35 . As a result, the rectified air can be sent out without requiring special modification of the main body of the air cleaner 35, so that the air flow sensor 69 can maintain the accuracy of detecting the amount of air.

Further, as shown in FIG. 21, a configuration in which a rectifying plate 78 is provided instead of the rectifier may be employed. The length L of the rectifying plate is configured to be (D×1/2) or more with respect to the diameter D of the pipe. As a result, the flow of air is rectified by the rectifying plate 78, so that the measurement of the air flow sensor 69 is stabilized. In FIG. 22, the configuration is such that air is sucked directly from the main body of the air cleaner 35, but the suction port 79 is configured to move from the suction port 79a. The length K from the main body of the air cleaner 35 is configured to be five times or more the inner diameter D of the suction port. As a result, intake pulsation especially in the low speed range is reduced, so that the measurement accuracy of the air flow sensor 69 is improved, the exhaust gas becomes cleaner, and the fuel consumption performance is improved.

The flowchart shown in FIG. 23 shows the operation of the EGR valve 43 at the time of sudden load. The EGR valve 43 is closed when the load suddenly acts and the accelerator change rate exceeds a predetermined value. This makes it possible to prevent a sudden rise in exhaust gas temperature.

The flowchart shown in FIG. 24 is configured such that the EGR valve 43 is closed when the upstream temperature sensor of the oxidation catalyst DOC 46a reaches a predetermined temperature or higher. This makes it possible to prevent a sudden rise in exhaust gas temperature.

The flowchart shown in FIG. 25 is configured such that the EGR valve 43 is closed when the rate of change of the fuel injection amount reaches or exceeds a predetermined value. This makes it possible to prevent a sudden rise in exhaust gas temperature.

FIG. 26 shows the structure of a case 81 covering the DOC 46a and the DPF 46b. A plug hole 80 is formed in the downstream end portion, and the plug hole 80 can be air-blown. This facilitates maintenance management. Also, the plug hole 80 may be provided between the DOC 46a and the DPF 46b, or may be provided in plurality.

It can be used for general vehicles as well as agricultural machinery such as tractors and combines.

E diesel engine PM particulate matter 46b diesel particulate filter (DPF)

Claims (3)

In a work vehicle equipped with a diesel particulate filter (46b) for collecting particulate matter (PM) in exhaust gas, the accumulated amount of particulate matter (PM) in the diesel particulate filter (46b) is equal to or greater than a predetermined value. When it becomes, it is configured to perform forced regeneration to reduce the PM deposition amount in the diesel particulate filter (46b), and is configured to notify by a notification means a predetermined time before performing the forced regeneration. vehicle. In a work vehicle equipped with a diesel particulate filter (46b) for collecting particulate matter (PM) in exhaust gas, the accumulated amount of particulate matter (PM) in the diesel particulate filter (46b) is equal to or greater than a predetermined value. Then, the diesel particulate filter (46b) is configured to perform forced regeneration to reduce the PM deposition amount, and when the accumulated engine operating time reaches a predetermined time regardless of the PM deposition amount in the diesel particulate filter (46b) 1. A working vehicle, characterized in that a notification means is used to notify that manual regeneration of a diesel particulate filter (46b) is urged. 3. The work vehicle according to claim 2, wherein the condition for the manual regeneration is displayed on the display means when the notification urging the manual regeneration is performed by the notification means.

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