JP2014148914A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently regenerate a diesel particulate filter provided in an exhaust passage of exhaust gas.SOLUTION: A diesel engine having a diesel particulate filter 46b for collecting particulate matters PM in exhaust gas is mounted on a work vehicle. In the work vehicle, an amount of the particulate matters PM accumulated in the diesel particulate filter 46b is displayed using an engine rotation meter 69 for displaying a number of revolution of an engine. Also, the work vehicle is provided with a PM amount switch 74 for switching on and off a function for displaying a PM amount in the diesel particulate filter 46b using the engine rotation meter 69.

Description

  The present invention relates to a work vehicle equipped with a diesel engine equipped with a diesel particulate filter (DPF).

  The accumulation amount of soot (PM) accumulated in the diesel particulate filter (DPF) is calculated, and this value is displayed on a dedicated display device (see, for example, Patent Document 1).

JP 2011-256882 A

In the technique as described above, a dedicated display device for displaying the amount of soot (PM) in the diesel particulate filter (DPF) is required, which increases the cost.
The subject of this invention is providing the work vehicle carrying the diesel engine which eliminates the above malfunctions.

The above object of the present invention is achieved by the following configuration.
That is, according to the first aspect of the present invention, in the work vehicle equipped with the diesel engine equipped with the diesel particulate filter (46b) for collecting the particulate matter (PM) in the exhaust gas, the engine speed is displayed. The work vehicle is characterized in that the amount of granulated material (PM) accumulated in the diesel particulate filter (46b) is displayed using an engine tachometer (69).

  The invention according to claim 2 is characterized in that a PM amount changeover switch (74) for turning on and off the function of displaying the PM amount in the diesel particulate filter (46b) using the engine tachometer (69) is provided. A work vehicle according to claim 1.

  According to the third aspect of the present invention, a diesel particulate filter (46b) is provided using the engine tachometer (69) only while the PM amount display switch (75) is provided and the PM amount display switch (75) is turned on. ) Is displayed, and the work vehicle according to claim 1 is displayed.

  In the invention according to claim 4, in a predetermined time after the power is turned on by the key switch for starting the engine, the engine speed sensor (69) is used to automatically set the power in the diesel particulate filter (46b). The work vehicle according to claim 1, wherein the work vehicle is configured to display a PM amount.

  Since the present invention is configured as described above, in the first aspect of the present invention, the particulates accumulated in the diesel particulate filter (46b) using the engine tachometer (69) for displaying the engine speed. Since the chemical substance (PM) is displayed, it is not necessary to provide a dedicated display unit, and the structure is inexpensive.

  In the invention according to claim 2, since the PM amount changeover switch (74) for turning on and off the function of displaying the PM amount in the diesel particulate filter (46b) using the engine tachometer (69) is provided, the driver It is possible to reflect the intentions of the company and to perform efficient work.

  In the invention of claim 3, since the PM amount in the diesel particulate filter (46b) is displayed using the engine tachometer (69) only while the PM amount display switch (75) is turned on, Even when the engine speed is displayed while traveling, the PM amount can be easily confirmed.

  In a fourth aspect of the present invention, in the diesel particulate filter (46b) automatically using the engine tachometer (69) for a predetermined time after the power is turned on by a key switch for starting the engine. Since the PM amount is displayed, it is possible to recognize the PM amount before work, and the work efficiency is improved.

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 Top view of meter panel Front view of tractor (A) Left side view of tractor (b) Rear view of tractor Rear view of tractor Front view of tractor (A) Front view of exhaust pipe (b) Partial enlarged front view of exhaust pipe Enlarged front view of part of the exhaust pipe

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

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

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

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

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

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

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

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

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

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

  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.
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 across the DPF 46b exceeds a predetermined value, the driver selects the regeneration mode of the DPF 46b after the operation with the selection switch 67, so that the DPF 46b is automatically regenerated. After the DPF 46b is regenerated, the engine is automatically stopped. To be configured. 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.
When the DPF 46b is regenerated, the intake side air may be sent from the pipe 61 to the upstream side of the DPF 46b as shown in FIG. That is, when the DPF 46b is regenerated, the valve 60 may be opened so that the intake air on the upstream side of the turbocharger TB having a large amount of oxygen is sent to the upstream side of the DPF 46b. Thereby, the reproduction efficiency is improved.

  Alternatively, the temperature of the DPF 46b may be monitored by the temperature sensors 62 and 59, and the temperature increase during regeneration may be confirmed in three steps. First, the intake is throttled (not shown), and the temperature rise in the throttled state of intake is confirmed. Next, the first post injection is performed to check the temperature rise. At this time, if the temperature before and after the DPF 46b does not reach 250 degrees, further temperature rise cannot be expected even if the second post-injection is performed. Therefore, the regeneration is temporarily interrupted. Of course, if it is 250 degrees or more, the second post injection is performed to regenerate the DPF 46b.

  As shown in FIG. 5, 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.

  It is desirable to inform the driver about the amount of PM accumulated in the DPF 46b during regeneration. Therefore, a configuration is adopted in which the accumulation amount in the DPF 46b is notified using the engine tachometer 69 shown in FIG. FIG. 6 is a front view of the meter panel 68. A liquid crystal display unit 70 is disposed at the center of the meter panel 68, and an engine tachometer 69 is disposed on the left side of the liquid crystal display unit 70. A course direction instruction unit 71 is disposed above the liquid crystal display unit 70, and various warning display units 72 are disposed below. Various warning display units and a traveling state display unit 73 are arranged on the right side of the liquid crystal display unit 70.

  The remaining fuel display section 70a is displayed on the left side of the liquid crystal display section 70, and the engine coolant temperature display section 70b is displayed on the right side. The central display unit 70c of the liquid crystal display unit 70 is configured to display the running state, usage time, engine load, and the like.

  When the DPF 46b is in the regeneration state, the character “DPF regeneration” is displayed on the central display portion 70c of the liquid crystal display unit 70. When the character during the DPF regeneration is displayed, the engine tachometer 69 indicates the PM amount in the DPF 46b. Is displayed. The PM amount is 100% at an engine speed of 2000 rpm, the PM amount is 50% at an engine speed of 1000 rpm, and the PM amount is 0% at an engine speed of 0 rpm.

  As described above, since the PM amount in the DPF 46b is displayed using the engine tachometer 69, it is not necessary to provide a display unit dedicated to the DPF, and the price is low. In addition, the driver can easily visually recognize that the regeneration of the DPF 46b is normally executed. In particular, the engine tachometer 69 is easy to recognize by analog display.

  As described above, when displaying the PM amount using the engine tachometer 69, it is basically during manual regeneration performed by stopping the aircraft, but may be displayed during automatic regeneration performed during traveling. . In this case, since the driver wants to recognize the engine speed, it is desirable to display it every predetermined time.

  Further, a PM amount changeover switch 74 for turning on and off the function of displaying the PM amount in the DPF 46b using the engine tachometer 69 may be provided so that the driver can select it. As a result, it is possible to reflect the intention of the driver and to drive efficiently.

  Further, a PM amount display switch 75 may be provided, and the PM amount in the DPF 46b may be displayed using the engine tachometer 69 only while the PM amount display switch 75 is being pressed. Thereby, it becomes easy to use especially at the time of automatic reproduction performed during traveling.

  Further, at a predetermined time (several seconds) after the key switch is turned on when the engine is started, or for a predetermined time (several seconds) after the engine is started, the PM amount in the DPF 46b is calculated using the engine tachometer 69. By configuring to display, it becomes possible to recognize the PM amount during traveling or before work, and work efficiency is improved.

  When the PM amount in the DPF 46b becomes a dangerous area (for example, 90% or more), the left and right lamps 71a and 71b of the course direction instructing unit 71 are blinked simultaneously. In this case, even when the PM amount in the DPF 46b is displayed using the engine tachometer 69, the left and right lamps 71a and 71b of the course direction indicating unit 71 are blinked simultaneously. Thereby, it becomes possible to easily recognize that the PM amount in the DPF 46b has entered the dangerous area. Further, the display of “DPF over-deposition” may be displayed on the central display portion 70 c of the liquid crystal display portion 70.

  In addition, the left and right direction indicators 76a and 76b (FIG. 3) on the outside of the fuselage are simultaneously blinked. However, the left and right direction indicators 76a and 76b and the left and right lamps 71a and 71b of the course direction indicating unit 71 are not blinked during automatic regeneration during traveling. Further, the driver's recognition is further increased by making an alarm sound with the buzzer 77 or automatically operating the wiper 78 as shown in FIG.

  Further, when the amount of PM in the DPF 46b enters the danger region, the work can be performed by checking the rotation of the PTO shaft that drives the work machine 21 (checking the connection of the PTO clutch) during work travel. It becomes possible to prevent damage due to excessive deposition of the DPF 46b.

  In addition, if another lamp 79 is provided and the lamp 79 blinks and the operation is continued as it is, the operation can be performed but the DPF needs to be regenerated in a short time (before the dangerous area or the dangerous area). May be configured to emit. Further, in the blinking of the lamp 79, the PM deposition amount in the operation state averaged over the past 10 seconds may be 0.5 g / L or more per hour. As a result, it becomes easier for the driver to recognize that driving over a long period of time will not be possible, and driving considering the work efficiency becomes possible.

  As shown in FIGS. 8A and 8B, a first exhaust pipe 80 is provided below the cabin 82, a second exhaust pipe 81 is provided behind the cabin 82, and exhaust gas from the engine E is supplied to the first exhaust pipe 80. The exhaust pipe 80 and the second exhaust pipe 81 are passed through and exhausted from the rear of the machine body. The DPF 46 b is provided between the first exhaust pipe 80 and the second exhaust pipe 81. In the first exhaust pipe 80, in order not to affect the cabin 82, for example, a vacuum double pipe configuration is adopted as a heat insulating pipe.

As described above, by not disposing the DPF 46b in the engine room E1, it is possible to prevent heat damage to the devices in the engine room E1.
Further, as shown in FIG. 9, in the second exhaust pipe 81, the rear view is not hindered by being along the vicinity of the rear column 82a of the cabin 82.

  In FIG. 10, the exhaust gas discharged from the upper part of the engine E passes through the DPF 46b in the engine room, and then the exhaust pipe 83 heads downward in the engine room and the exhaust pipe 84 heads laterally outside the engine room from the engine room. The exhaust gas is exhausted through the exhaust pipe 85 directed upward of the cabin 82. FIG. 11 shows the details.

  A gap hole portion 84a is formed at a connection portion between the exhaust pipe 83 that extends downward and the exhaust pipe 84 that extends laterally from the engine room to the outside of the machine. When the engine speed is increased and the exhaust gas flow rate is increased to increase the exhaust gas flow rate, the diffuser effect causes outside air to be taken in from the gap hole portion 84a, and the exhaust gas temperature discharged from the exhaust pipe 85 directed upwards. Will begin to decline. Further, when the engine is stopped or when the exhaust gas flow rate is small, the accumulated condensed water is discharged from the gap hole portion 84a, so that it is possible to prevent water from scattering from the exhaust pipe 85 directed upward. Become.

  Moreover, as shown in FIG. 12, the large diameter part 84b which enlarged the diameter of a part of exhaust pipe 84 which goes to a horizontal direction is comprised. Further, a drain plug 84c is provided in the large diameter portion 84b. Although condensed water accumulates in the large diameter portion 84b, even if the exhaust gas flow rate is high and the exhaust gas flow rate increases, the condensed gas accumulates in the large diameter portion 84b, so that the exhaust gas passes above the condensed water. Accordingly, it is possible to prevent water from being scattered from the exhaust pipe 85 directed upward. Moreover, since condensed water turns into water vapor | steam with progress of time, it will not scatter.

Further, removing the drain plug 84c and periodically discharging the condensed water is effective when the condensed water does not evaporate during cold or light load work.
When the DPF 46b is regenerated, post injection is performed as described above, but it is necessary to prevent post injection from being performed excessively. Therefore, the moving average value of the post injection amount at the target automatic regeneration interval is calculated. When this value is larger than the reference value, the automatic regeneration is prohibited. The automatic reproduction is resumed when the moving average value becomes equal to or less than the reference value.

  Specifically, for an engine design target with a target automatic regeneration interval of 10 h and an allowable post injection amount of 1000 cc, a 10 h moving average of the post injection amount is calculated, and a 10 h moving average value of the post injection amount is 100 cc / When h (1000 cc / 10h) is exceeded, automatic regeneration is prohibited, and only manual regeneration that allows regeneration of the DPF with a post injection amount smaller than automatic regeneration is permitted.

When automatic reproduction is prohibited, when the moving average value falls below a permission threshold provided in an area smaller than the prohibition threshold, resumption of automatic reproduction is permitted.
If the post-injection amount at the oil dilution limit is judged not by moving average but by short-term post-injection increase / decrease, automatic regeneration must be interrupted more than necessary, but the presence or absence of abnormality is judged by moving average against the design target. By doing so, it is possible to appropriately prevent excessive post-injection in the minimum necessary automatic regeneration prohibition period. Thereby, excessive oil dilution can be prevented.

  In addition, as described above, the moving average value of the post-injection amount at the target automatic regeneration interval is calculated, and if a period in which this value is greater than the reference value has exceeded a certain value, a warning is given to perform oil maintenance. A structure that emits

  Specifically, for an engine design target with a target automatic regeneration interval of 10 h and an allowable post injection amount of 1000 cc, a 10 h moving average of the post injection amount is calculated, and a 10 h moving average value of the post injection amount is 100 cc / When h (1000 cc / 10h) is exceeded, the time after the time is accumulated. A warning is issued so that oil maintenance is performed every time the accumulated time exceeds a certain time.

  When the moving average of the post injection amount falls below the reference value, the accumulated time is reset to zero. When there is an input notifying that the oil change has been performed, the moving average value of the post injection is reset to zero. As a result, it is possible to prevent engine damage by estimating the occurrence of excessive oil dilution with respect to the design target and issuing an oil maintenance instruction.

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

PM Granulated material 46b Diesel particulate filter (DPF)
69 Engine tachometer 74 PM amount changeover switch 75 PM amount display switch

Claims (4)

  In a work vehicle equipped with a diesel engine equipped with a diesel particulate filter (46b) that collects particulate matter (PM) in exhaust gas, an engine tachometer (69) that displays the engine speed is used. A work vehicle characterized by displaying the amount of granulated material (PM) accumulated in a diesel particulate filter (46b).   The work vehicle according to claim 1, further comprising a PM amount changeover switch (74) for turning on and off a function of displaying the PM amount in the diesel particulate filter (46b) using the engine tachometer (69).   A PM amount display switch (75) is provided, and the PM amount in the diesel particulate filter (46b) is displayed using the engine tachometer (69) only while the PM amount display switch (75) is turned on. The work vehicle according to claim 1.   It is configured to automatically display the PM amount in the diesel particulate filter (46b) using the engine tachometer (69) for a predetermined time after the power is turned on by a key switch for starting the engine. The work vehicle according to claim 1, wherein

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