JP2011132924A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently regenerate a diesel particulate filter provided in an engine room. <P>SOLUTION: In this working vehicle mounted with a diesel engine provided with the diesel particulate filter for capturing a granulated substance in exhaust emission discharged from a cylinder of the diesel engine, the diesel particulate filter is provided in a place for passing some of cooling air from a cooling fan for blowing cooling air to the diesel engine in the engine room where the diesel engine is mounted. A partition plate is provided between the diesel particulate filter and the engine, and in regenerating the diesel particulate filter, the drive of the cooling fan is stopped. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a work vehicle including a diesel engine including a diesel particulate filter.

  A diesel particulate filter (DPF) is disposed in the engine room (see, for example, Patent Document 1).

JP 2008-31955 A

The above-described technique has a problem in that when the cooling air hits the DPF, the temperature rise of the DPF is suppressed during the regeneration of the DPF, and the regeneration cannot be performed efficiently.
The subject of this invention is providing the work vehicle which eliminates the above malfunctions.

The above object of the present invention is achieved by the following configuration.
That is, in the invention according to claim 1, a diesel engine provided with a diesel particulate filter (46 b) that collects the particulate matter (PM) in the exhaust gas discharged from the cylinder (5) of the diesel engine (E) ( In the work vehicle equipped with E), a part of the cooling air from the cooling fan (61) that blows the cooling air to the diesel engine (E) passes through the engine room where the diesel engine (E) is installed. A diesel particulate filter (46b) is provided at a location, a partition plate (63) is provided between the diesel particulate filter (46b) and the engine (E), and when the diesel particulate filter (46b) is regenerated. The cooling fan (61) is configured to stop driving. It is obtained by a work vehicle.

  The combusted exhaust gas exits from the cylinder (5) of the diesel engine. On the way, the exhaust gas passes through the diesel particulate filter (46b) in the engine room. At this time, the granulated material (PM) contained in the exhaust gas is collected by the diesel particulate filter (46b). For this reason, the diesel particulate filter (46b) needs to be regenerated. When regenerating the diesel particulate filter (46b), the drive of the cooling fan (61) is stopped.

  In invention of Claim 2, the cooling water temperature sensor (E1) which detects the cooling water temperature of the said diesel engine (E) is provided, and the exhaust pipe (between a diesel engine (E) and a diesel particulate filter (46b)) ( 64) is provided with an exhaust pipe heating means (65), and when the detected value of the cooling water temperature sensor (E1) is a predetermined value or more, the exhaust pipe heating means (65) is stopped without stopping the driving of the cooling fan (61). 65) The work vehicle according to claim 1, wherein the exhaust pipe (64) is heated in step 65).

  When the detected value of the cooling water temperature sensor (E1) of the diesel engine is equal to or greater than a predetermined value, the exhaust pipe (64) is heated by the exhaust pipe heating means (65) without stopping the driving of the cooling fan (61).

  Since the present invention is configured as described above, according to the first aspect of the present invention, the driving of the cooling fan (61) is stopped when the DPF (46b) is regenerated, so that the temperature of the DPF (46b) increases rapidly. Thus, the regeneration of the DPF (46b) can be performed efficiently.

  In the invention according to claim 2, in addition to the effect of claim 1, when the detected value of the cooling water temperature sensor (E1) is equal to or greater than a predetermined value, the driving of the cooling fan (61) is not stopped. ) Overheating can be prevented. Further, since the exhaust pipe (64) between the diesel engine (E) and the diesel particulate filter (46b) is heated by the exhaust pipe heating means (65), the exhaust gas temperature rises. As a result, the DPF (46b ) Is efficiently performed.

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 Schematic diagram of intake and exhaust systems Perspective view around the engine Cross section of exhaust pipe Schematic diagram of temperature sensor layout Time chart of time and temperature change of post-processing equipment Left side view around the engine Right side view around the engine Perspective view around the engine Flow chart Time chart of time and temperature change of post-processing equipment Time chart of time and temperature change of post-processing equipment Time chart of time and temperature change of post-processing equipment (A) Left side view around the engine, (b) Top view around the engine Left side view around the engine

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 and the fuel injection nozzle 6, etc. Consists of ECU is an abbreviation for engine control unit. The ECU 100 is connected to the CPU 200 on the machine side and exchanges information with each other.

Thus, the common rail 1 injects fuel to each cylinder 5 of the engine E, and makes the fuel supply 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 travel mode A is droop control in which the engine speed changes due to load fluctuations. As the engine speed changes, the output also changes. It is used when traveling without farming. For example, if the running speed is decelerated or stopped by applying a brake, the engine speed fluctuates (decreases) as the running load increases, so the running speed can be reduced or stopped safely. is there.

  The normal work mode B is isochronous control that keeps the engine speed constant even when the load fluctuates. It is used for normal farm work. For example, in the case of a tractor, the cultivated land is hard at the time of plowing work and resistance is applied to the plowing blade.

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

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

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

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

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

  The tractor includes front wheels 12 and 12 and rear wheels 13 and 13 at the front and rear portions of the fuselage, and the rotational power of the engine E mounted on the front portion of the fuselage is appropriately decelerated by a transmission in the transmission case T, so , 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 and lowers the working machine 21.

  FIG. 5 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 36 of the supercharger TB passes through the intake turbine 36 and the intercooler 37 from the air cleaner 35 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.
This 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 material chamber, and the diesel particulate filter (DPF) is for collecting the granulated material chamber (PM). The EGR valve 43 and the throttle valve 47 are controlled by the ECU 100. The post-treatment device 46 may be constituted only by a diesel particulate filter (DPF) 46b. If an oxidation catalyst (DOC) 46a is provided, the non-combustible material burns, so that the exhaust gas becomes cleaner.

  When the state of the exhaust gas temperature is low (low load) continues for a long time, the DPF 46b has a concern that PM accumulates and the capacity is lowered. 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. As a result, the DPF 46b can be regenerated under 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 DPF regeneration operation, a pressure sensor 52 is provided on the upper side of the post-processing device 46, and when the value of the pressure sensor 52 exceeds a predetermined value, PM accumulates in the DPF 46b. Therefore, the DPF regeneration operation is performed.

  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 53 is provided on the lower side of the post-processing device 46, and when the value of the temperature sensor 53 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 53 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 53 has risen to a predetermined value or more. 58 is a temperature sensor, 59 is a pressure sensor, and 60 is a temperature sensor, which are used for other controls.

  In the post-processing device 46 configured as described above, where to mount the tractor becomes a problem. Therefore, the arrangement is as shown in FIG. Specifically, it is configured to be disposed above the engine E mounted in the engine room covered with the bonnet.

Next, FIG. 6 will be described.
This figure shows an example in which the DPF 46b is placed horizontally above the engine E. 61 is a cooling fan, and 62 is a cooling fan motor for driving the cooling fan 61. Reference numeral 63 denotes a partition plate that partitions the DPF 46b and the engine E main body. Therefore, the wind generated by the cooling fan 61 flows toward the engine E side and the DPF 46b side to be cooled. Since a radiator (not shown) is disposed in front of the cooling fan 61, the wind generated by the cooling fan 61 also cools the radiator. Thus, by disposing the DPF 46b above the engine E in the engine room, the appearance of the entire body is improved and a compact configuration is obtained. Further, by providing the partition plate 63, it is possible to prevent the influence of the heat of the DPF 46b from being exerted on the engine and peripheral devices. Since a part of the cooling air from the cooling fan 61 is directed toward the DPF 46b, it is possible to lower the ambient temperature around the DPF 46b, and to prevent thermal damage.

  However, when the DPF 46b is regenerated, the temperature of the DPF 46b itself must rise to a predetermined value or more. However, in the configuration shown in FIG. There is a problem that the DPF 46b cannot be regenerated efficiently.

  Therefore, when the regeneration (manual regeneration, automatic regeneration) of the DPF 46b is started, the driving of the cooling fan motor 62 driving the cooling fan 61 is stopped. Thereby, the temperature rise of the DPF 46b is accelerated, and the DPF 46b can be efficiently regenerated.

  At this time, there is no problem if the temperature of the engine E itself, the temperature of the engine oil, and the temperature of the cooling water are low. However, in particular, when the temperature of the cooling water is high, if the driving of the cooling fan motor 62 is stopped, there is a possibility of overheating. Therefore, a cooling water temperature sensor E1 for detecting the temperature of the cooling water is provided (installed in the cooling water path system), and information on the cooling water temperature is input to the ECU 100. Rotate with. If there is still a possibility of overheating, the cooling fan motor 62 is driven at normal rotation. At this time, a configuration is adopted in which a current is passed through a hot wire 65 described later to raise the temperature of the exhaust gas before entering the DPF 46b. As a result, overheating of the engine E can be prevented and the regeneration efficiency of the DPF 46b is improved. Further, when the temperature of the exhaust gas measured by the temperature sensors 58 and 60 in the post-processing device 46 described above becomes equal to or higher than a predetermined value, the heating of the hot wire 65 is stopped. A configuration in which the DOC 46a is provided on the upstream side of the DPF 46b may be employed.

  Reference numeral 64 denotes an exhaust pipe between the supercharger TB and the DOC 46a (or DPF 46b), and is constituted by a flexivir pipe. And as shown in FIG. 7, it is set as the structure which winds the hot wire 65 to the recessed part of the flexivir pipe | tube which is an uneven | corrugated state. A heater circuit 66 is formed around the heat wire 65. The ECU 100 receives information from the temperature sensors 58 and 59 in the post-processing device 46, and determines whether the temperature has risen to a temperature required for regeneration of the DPF 46b. If the temperature reaches the required temperature, no current flows through the hot wire 65, but if the temperature does not rise to the required temperature, the current flows through the hot wire 65. As a result, the temperature of the hot wire 65 and the exhaust pipe 64 (flexible building pipe) rises, and the temperature of the exhaust gas passing through the exhaust pipe 64 rises, so that the regeneration efficiency of the DPF 46b is improved.

  FIGS. 8 and 9 are control configurations for reducing the target temperature arrival time in the DPF 46b. A temperature sensor T1 is provided on the upstream side of the DOC 46a, and a temperature sensor T2 is provided on the downstream side of the DOC 46a. Further, a temperature sensor T3 is provided on the downstream side of the DPF 46b. A line T0 in FIG. 9 is a target temperature in the DPF 46b when the DPF 46b is regenerated.

  When the DPF 46b is regenerated, post injection is performed after the main injection, and the post injection amount is changed according to the gradient of change in the value of the temperature sensor T2 installed on the downstream side of the DOC 46a. That is, the normal post injection amount is multiplied by a predetermined coefficient according to the degree of inclination. When the inclination is small, the coefficient is increased, and when the inclination is large, the coefficient is decreased. Thereby, the target temperature arrival time in the DPF 46b is shortened, and the DPF 46b is efficiently regenerated.

  In the configuration of FIG. 10, the DPF 46 b is installed above the engine E in the engine room and the upper portion is covered with the bonnet 68 as in the configuration of FIG. 6 described above. A shielding plate 70 is provided in front of the DPF 46b, and a shielding plate 71 is provided around the DPF 46b and between the engine E. In addition, a guide plate 71 is provided behind the DPF 46b, receives air from the cooling fan 61, guides it, and discharges it from the slit 69 of the bonnet 68 to the outside of the machine. The slit 69 is positioned near (above) the DPF 46b.

  Thereby, since the cooling air from the cooling fan 61 does not directly hit the DPF 46b, the temperature inside the DPF 46b can be maintained at a high temperature, and the regeneration of the DPF 46b can be efficiently performed.

  In addition, the temperature around the DPF 46b increases as a result of this configuration, which may cause thermal damage to peripheral devices. However, the wind from the cooling fan 61 is guided by the guide plate 72 and is located above the DPF 46b. Since the air is discharged from the slit 69 of the bonnet 68 to the outside of the machine, the air around the DPF 46b goes out together and the ambient temperature around the DPF 46b is lowered to cause heat damage to the equipment. Can be prevented.

  Reference numeral 14 denotes a cabin. The route for discharging the air in the cabin 14 to the outside of the aircraft is configured to be discharged through a route R1 as indicated by an arrow. That is, the air is discharged from the front portion of the cabin 14 into the engine room, passes through the outside of the guide plate 72, merges with the wind from the cooling fan 61, and is discharged from the slit 69 of the bonnet 68. As a result, the convection of the air in the engine room is increased, so that the ambient temperature is lowered, and heat damage to various devices in the engine room can be prevented.

  In addition to the route R1, the route for discharging the air inside the cabin 14 to the outside is configured to be provided with a route R2. Normally, the exhaust gas is discharged from the route R2 to the outside of the apparatus. However, the exhaust gas may be switched from the route R2 to the route R1 due to the temperature rise of the exhaust gas downstream of the DPF 46b. The exhaust gas temperature measuring sensor on the downstream side of the DPF 46b is measured by the temperature sensor T3 shown in FIG.

  As shown in FIG. 11, the engine E and the DPF 46 b arranged in the engine room 80 are separated by a partition plate 73 and are arranged independently. A fan 81 is provided so that the ambient temperature of the air around the DPF 46b does not rise too much. The driving of the fan 81 is configured such that the fan 81 is rotationally driven by being transmitted from a pulley 77 provided on the crankshaft 76 to a pulley 79 provided on the fan 81 via a belt 78. FIG. 12 shows a perspective view.

  Further, an air intake port 74 is provided in the bonnet 68 so that air is taken in by the suction force of the fan 81. And it is comprised so that it may exhaust from the air discharge port 75 outside the apparatus. The position of the discharge port 75 is a position where the air around the DPF 46b is efficiently discharged to the outside of the machine. As a result, the ambient temperature of the air around the DPF 46b, which is considerably high during regeneration, can be lowered. Further, if the wind generated from the fan 81 is too strong, the temperature of the main body of the DPF 46b is lowered, so that the speed ratio of the pulley 77 and the pulley 79 is set so that the rotational speed of the fan 81 does not become too fast. To be determined.

  The flowchart of FIG. 13 is a method for dealing with a case where PM abnormally burns in the DPF 46b. If the abnormal combustion is left unattended, the DPF 46b may be melted. The measured temperature value after DPF in this flowchart is a measured value by the temperature sensor T3 shown in FIG.

The relationship of the reference temperature is
Reference temperature T4 <reference temperature T5 <reference temperature T6
It is.

  If the post-DPF temperature is higher than the reference temperature T4 in step S1, post injection is stopped in step S2. Next, when the post-DPF temperature is higher than the reference temperature T5 in step S3, the closing amount of the intake valve is increased in step S4. If the post-DPF temperature is not lower than the reference temperature T6 in step S5, that is, if it is higher than the reference temperature T6, the engine is urgently stopped. If the post-DFF temperature is lower than the reference temperature T6 in step S5, the progress is monitored in step S6. If the post-DFF temperature becomes lower than the reference temperature T7 in step S7, the engine is instructed to stop.

  When the temperature is higher than the reference temperature T5, the regeneration control (post injection) of the DPF 46b is not performed even if the temperature once falls. Then, the regeneration control (post-injection) is resumed when the temperature drops to the temperature at which the regeneration control of the DPF 46b is started. However, since the regeneration is performed to some extent until the temperature exceeds the reference temperature T5, the regeneration is performed again. You may comprise so that regeneration control may be performed after it must be in a state (pressure value rise).

  FIG. 14 is a graph showing the flow of the flowchart of FIG. 13, where the horizontal axis is the time flow and the vertical axis is the temperature. Once the DPF 46b is in a high temperature state, it is a temperature that has dropped to near the normal temperature of the reference temperature T7. Although it has been lowered to a temperature close to the normal temperature, but once raised to a high reference temperature T5, when the temperature drops to the reference temperature T7, the engine is stopped (not urgent) and maintenance is performed. To do. In this manner, by suppressing the combustion speed in the DPF 46b, abnormal combustion in the DPF 46b can be eliminated, and the DPF 46b itself can be prevented from being melted.

Next, FIG. 15 will be described.
This is a control configuration in the case where the engine is manually stopped (may be automatically stopped) without completion of regeneration in a state where the rear temperature of the DPF 46b (the value of the temperature sensor T3 shown in FIG. 8) exceeds a certain reference temperature T8. . In this case, a configuration is adopted in which the restart of the engine is checked if the post-temperature of the DPF 46b and the coolant temperature of the engine are not lowered below the safety determination temperature. When the rear temperature of the DPF 46b and the cooling water temperature of the engine fall below a predetermined safety judgment temperature, the engine can be started. Then, after the engine is restarted, the DPF 46b is urged to be played back by voice or a display device. As described above, when the rear temperature of the DPF 46b exceeds a certain reference temperature T8, the engine is automatically stopped, thereby preventing abnormal combustion or melting of the DPF 46b. Further, when the rear temperature of the DPF 46b and the cooling water temperature of the engine fall below a predetermined safety judgment temperature, the engine can be started and the regeneration control of the DPF 46b is restarted, thereby improving the safety.

  Further, as shown in FIG. 16, when the rear temperature of the DPF 46b becomes an abnormally high temperature T9, the engine is urgently stopped. Even in this case, when the rear temperature of the DPF 46b and the cooling water temperature of the engine are equal to or lower than a predetermined safety judgment temperature, control for permitting restart of the engine is performed. In this case, since the temperature of the DPF 46b has risen to the abnormally high temperature T9, after the engine is restarted, it is configured to check work operations such as driving the PTO that have a large load and only move the work vehicle. The configuration is allowed. In addition, after the engine is restarted, a DPF replacement instruction is urged (sound, display device, etc.), and the replacement is executed and the work operation is permitted after the error is reset. Thereby, abnormal combustion and melting loss of DPF are prevented, and safety is improved.

FIG. 17A is a left side view around the engine, and FIG. 17B is a plan view around the engine in FIG.
As shown in FIG. 17A, the DPF 46 b is provided on the left side of the engine E and inside the side cover 82. A part of the side cover 82 is cut away to arrange the DPF 46 b, and the outside of the DPF 46 b is covered with the cover 83. The cover 83 may be integrated with the side cover 82 by plastic deformation. The DPF 46b is attached to the cover 83 via a stay 83 (anti-vibration rubber or the like). Reference numeral 85 denotes a slit opening for exhaust heat.

  Further, since the DPF 46b and the engine E are connected by a flexible pipe 86, the DPF 46b rotates sideways around the rotation fulcrum 84 together with the side cover 82 and the cover 83. Thereby, maintenance of the engine E main body, the DPF 46b, and the like can be easily performed.

  FIG. 18 shows a configuration when the DPF 46 b is provided inside the hood 68. The DPF 46b is attached to the inside of the bonnet 68 via a support member 89 (vibration isolation rubber or the like). Since the DPF 46b and the engine E are connected by the flexible pipe 87, when the bonnet 68 is opened around the rotation fulcrum 88, the DPF 46b is also rotated. Thereby, maintenance of the engine E main body, the DPF 46b, and the like can be easily performed.

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

5 Diesel engine cylinder 46b Diesel particulate filter (DPF)
61 Cooling fan 63 Partition plate 64 Exhaust pipe (flexible building pipe)
65 Exhaust pipe heating means (heat wire)
E Diesel engine E1 Cooling water temperature sensor PM Granulated material

Claims (2)

  In a work vehicle equipped with a diesel engine (E) provided with a diesel particulate filter (46b) for collecting particulate matter (PM) in exhaust gas discharged from a cylinder (5) of the diesel engine (E), diesel A diesel particulate filter (46b) is placed in a place where a part of the cooling air from the cooling fan (61) for blowing cooling air to the diesel engine (E) passes in the engine room in which the engine (E) is mounted. The partition plate (63) is provided between the diesel particulate filter (46b) and the engine (E), and the driving of the cooling fan (61) is stopped when the diesel particulate filter (46b) is regenerated. A work vehicle characterized by being configured to do so.   A cooling water temperature sensor (E1) for detecting the cooling water temperature of the diesel engine (E) is provided, and an exhaust pipe heating means (in the exhaust pipe (64) between the diesel engine (E) and the diesel particulate filter (46b)). 65), and when the detected value of the cooling water temperature sensor (E1) is equal to or greater than a predetermined value, the exhaust pipe heating means (65) does not stop the driving of the cooling fan (61) and the exhaust pipe (64) The work vehicle according to claim 1, wherein the work vehicle is configured to be heated.

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