JP2012233430A - Working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an efficient work by grasping the status of a diesel particulate filter provided in the discharge path of an exhaust gas.SOLUTION: The working vehicle equipping a diesel engine provided with a diesel particulate filter 46b which collects particulate materials PM from the exhaust gas includes: accumulated amount detection means 58 and 53 which detect the accumulate amount of the particulate materials PM in a diesel particulate filter 46b to indicate the accumulated amount P2 detected by the accumulated amount detection means 58 and 53 on an indication means 68 of the working vehicle.

Description

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

  A technique is disclosed in which clogging of a diesel particulate filter (DPF) is determined and self-regeneration processing of the DPF is performed when the DPF is clogged (see, for example, Patent Document 1).

JP 2010-270610 A

  With the above-described technology, the driver of the vehicle cannot know how much the DPF is clogged. Further, when the DPF becomes clogged, the DPF self-regenerates. However, there is a drawback that the work content is limited depending on conditions during the self-regeneration.

  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 a work vehicle equipped with a diesel engine equipped with a diesel particulate filter (46b) that collects particulate matter (PM) in exhaust gas, the diesel particulate filter (46b) A deposit amount detecting means (58, 53) for detecting the amount of particulate matter (PM) in the inside is provided, and the deposit amount (P2) detected by the deposit amount detecting means (58, 53) is displayed on the display means ( 68), the work vehicle is characterized by being configured to display.

  The operation of claim 1 displays the particulate matter (PM) deposition amount (P2) detected by the deposition amount detection means (58, 53) on the display means (68) of the work vehicle.

  According to the second aspect of the present invention, the PM accumulation amount (R) per unit time in the past predetermined time during engine operation and the PM amount (P) that can be accumulated in the diesel particulate filter (46b) are calculated from the PM accumulation amount (R). The work vehicle according to claim 1, wherein the operation possible time (J) until manual regeneration is calculated and displayed on the display means (68).

  The operation of claim 2 calculates the remaining operable time (J) until manual regeneration of the diesel particulate filter (46b) and displays it on the display means (68).

  In the third aspect of the present invention, the particulate matter (PM) removal amount (S) per unit time when the diesel particulate filter (46b) is manually regenerated and the accumulation amount detection means (58, 53) From the state of the detected amount (P2) of granulated material (PM), manual regeneration is performed to calculate the time (J1) required for removing the granulated material (PM) and display it on the display means (68). The work vehicle according to claim 1 or 2, wherein the work vehicle is configured.

  According to the third aspect of the present invention, manual regeneration of the diesel particulate filter (46b) is performed to calculate the time (J1) required for removing the particulate matter (PM) and display it on the display means (68).

  In the invention according to claim 4, the post injection integrated amount (H) of the post injection amount that is performed at the time of regeneration of the diesel particulate filter (46b) is calculated, and if the post injection integrated amount (H) exceeds a predetermined value, the engine The work vehicle according to claim 3, wherein a display for prompting oil change is displayed on the display means (68).

  The operation of claim 4 is to calculate the post injection integrated amount (H) of the post injection amount performed at the time of regeneration of the diesel particulate filter (46b), and when the post injection integrated amount (H) exceeds a predetermined value, the oil change of the engine Is displayed on the display means (68).

  Since the present invention is configured as described above, according to the first aspect of the present invention, the work can be efficiently performed while determining the amount (P2) of the granulated material (PM) deposited.

  In the invention according to the second aspect, efficient work can be performed while referring to the remaining operable time (J) until the manual regeneration of the diesel particulate filter (46b).

  In the invention according to claim 3, by referring to the time (J1) required for removing the particulate matter (PM) from the diesel particulate filter (46b), it is possible to efficiently prepare for the next operation.

  In the invention according to the fourth aspect, the engine oil can be prevented from being diluted more than necessary, and the optimum engine oil replacement time can be set, so that economical operation management is possible.

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 Block diagram of accumulation amount detection means and display means Flow chart of engine oil change Schematic diagram of DPF burner DPF burner enlarged schematic diagram Relationship between accelerator operation and fuel injection Governor control block diagram Engine performance curve

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

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

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

  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 led 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.

  As described above, by measuring the differential pressure across the DPF 46b with the front pressure sensor 58 and the rear pressure sensor 53, it is possible to estimate the PM accumulation amount P2 grams (g) in the DPF 46b. The PM accumulation amount P2 is calculated by the ECU 100 and transmitted to the tractor-side CPU 200 by CAN communication to display the current PM accumulation amount P2 on the tractor meter panel 68 (DPF indicator in FIG. 6). As a result, it is possible to perform work efficiently while taking into account the PM accumulation amount P2. Other methods may be used for calculating the PM deposition amount P2.

In addition, by calculating the PM accumulation amount R (g / min) per unit time within the past predetermined time, and calculating the operable time J (min) until manual regeneration and displaying it on the meter panel 68. Considering the work contents, the field condition, the field area, etc., the work can be performed efficiently.
Let P1 (g) be the limit value at which PM can accumulate in the DPF 46b.
If the current PM amount in the DPF 46b is P2 (g),
The remaining depositable amount is P (g) = P1−P2.
Then, the operable time J (min) until manual regeneration is calculated by P / R.
Since the DPF indicator of FIG. 6 is a liquid crystal display, the time display may be switched to the time display or the PM amount may be displayed simultaneously.

  Further, as described above, when performing manual regeneration (performed when the PM accumulation amount reaches the limit), it is necessary to interrupt the work. Therefore, the amount of PM accumulation can be reduced by performing automatic regeneration during work. However, if the engine load during work is small and the exhaust temperature does not rise above the specified value, automatic regeneration may not be possible. Therefore, the vehicle speed may be shifted to a higher speed or the engine load may be increased by increasing the PTO speed. You may make it raise. Even during such automatic regeneration, by displaying the current PM amount P2 on the meter panel 68, it becomes possible to know whether automatic regeneration is being performed, thereby improving work efficiency.

When the manual regeneration as described above is performed with the operation suspended, the current PM accumulation amount P2 is displayed on the meter panel 68 and the remaining time J1 of the manual regeneration is displayed. It becomes easy to make a work plan.
The amount of PM removed per unit time is S (g / min),
If the current PM amount in the DPF 46b is P2 (g),
The remaining time required for manual regeneration is J2 (min) = P2 / S.

  As described above, when the DPF 46b is regenerated (automatic or manual), post injection is performed after the main injection, and combustion is performed from the cylinder to the exhaust pipe to raise the exhaust gas temperature. However, when post-injection is performed, oil dilution (a part of fuel enters the oil pan) occurs and engine oil is diluted, which adversely affects the engine.

Accordingly, the ECU 100 calculates the oil dilution amount by integrating the post injection amount H, and when the calculated oil dilution amount exceeds a predetermined amount, the meter panel 68 is displayed to prompt oil replacement. And As a result, the engine can be protected and the optimal oil change time can be known, so that efficient and economical operation management can be performed.
The injection amount per post injection is H1 (g / time),
If the number of post injections is x times,
The post injection integrated amount H (g) = H1 * x.

  FIG. 8 shows a configuration in which a burner 69 is provided on the upstream side of the DPF 46b. When fuel is injected and burned by the burner 69, the exhaust gas temperature rises, so that the regeneration of the DPF 46b can be performed efficiently. Further, if the exhaust gas temperature rises too much, the DPF 46b is damaged, so it is necessary to measure the exhaust gas temperature with a temperature sensor on the downstream side of the burner 69 and to control the combustion of the burner 69.

  However, since the tractor uses light oil, the fuel injection nozzle is a high-pressure type, but the high-pressure type is disadvantageous in that it is expensive. Therefore, although the low pressure type fuel injection nozzle 70 is used, the low pressure type generates a lot of fuel that does not form a mist and wastes fuel wastefully.

  Therefore, as shown in FIG. 9, the fuel fed from the fuel pump 4 is injected from the low-pressure fuel injection nozzle 70 and ignited by the glow plug 71 and burned. The unburned fuel collides with the collision plate 72, falls downward, is received by the inclined plate 73, and gathers in one place. Since the relatively hot exhaust gas passes below the inclined plate 73, the fuel received by the inclined plate 73 evaporates and combines with the oxygen in the exhaust gas to burn. Thereby, fuel can be used effectively.

  When the fuel injection response is improved with respect to the accelerator operation, a large amount of PM is generated, and when the fuel injection response is deteriorated, the PM is less likely to be generated. Therefore, as shown in FIG. 10, the fuel injection sensitivity adjustment dial 74 (FIG. 6) is provided to improve or deteriorate the response of fuel injection to the accelerator operation. Line L1 is an accelerator operation, and line L2 indicates fuel injection. 10A shows a state where the fuel injection response is good, and FIG. 10B shows a state where the fuel injection response is bad. As described above, although the fuel injection response is deteriorated, the regeneration interval of the DPF 46b can be extended by configuring the PM generation amount so that the operator can intentionally select it.

  The tractor has a function of automatically lowering the engine speed when raising the work implement 21 attached to the rear and returning the engine speed when the work implement 21 is lowered again. Further, when the tractor is moving backward, there is a function of automatically reducing the engine speed and returning the engine speed when moving forward again. In such a function, the state set by the fuel injection sensitivity adjustment dial 74 is applied. Moreover, it is good also as a structure which provides the switch which selects the propriety of this application. As a result, the regeneration interval of the DPF 46b can be extended.

  In addition, there is a type in which a work dial is provided in the tractor. This work dial is configured to select travel (on the road) and work, and to select work content for the work. When road driving, towing work, loader work, or the like is selected with this work dial, the fuel injection response as shown in FIG. 10A regardless of the setting or presence of the fuel injection sensitivity adjustment dial 74. Is automatically improved. Further, when a rotary work with a large load is selected with the work dial, the fuel injection response is automatically deteriorated as shown in FIG. Thereby, agile movement is possible depending on the work content and the like, and when no agile movement is required, the amount of PM generated can be suppressed.

  Next, the standard mode and the low fuel consumption mode in the mechanical engine (operating the governor with the throttle) will be described. The tractor is provided with a low fuel consumption mode switch 75 at an arbitrary position. As shown in FIG. 11, when the low fuel consumption mode switch 75 is turned on, the governor actuating actuator 76 forcibly returns the throttle to the low rotation side by a predetermined amount (line L3 shown in FIG. 12). As a result, the engine speed can be easily suppressed in the mechanical engine, and the fuel consumption is improved.

  In this case, when a load is applied and the engine speed sensor 78 detects a decrease in the engine speed, the governor actuating actuator 76 is operated so that the engine speed indicated by the accelerator lever (pedal) is obtained. By controlling, stable work traveling becomes possible. Further, when the load is heavy and the engine speed is drastically reduced, when the engine speed fluctuates greatly, or when the engine speed is not stable, the engine speed (the line in FIG. 12) is higher than the value indicated by the accelerator lever (pedal). L4). As a result, the mechanical engine can be operated at a stable engine speed.

  The load factor in the mechanical engine is calculated by (current rotation speed / maximum rotation speed in the low fuel consumption mode). If the load ratio value is higher than a predetermined threshold value, the sub-shift of the tractor is set to 1. It is set as the structure which shifts in a step deceleration direction.

  Further, in the mechanical engine, when the low fuel consumption mode switch 75 is turned on and the low fuel consumption mode is selected, the full rack position is controlled by a predetermined value (Xmm) and the engine torque is controlled to be reduced (I / (The solenoid at the rear end of PUMP is operated by X mm to set the full rack position to (Full position−X mm).) Thereby, work traveling with low fuel consumption becomes possible.

PM Granulated substance P PM amount that can be accumulated in diesel particulate filter P2 PM accumulation amount detected by the accumulation amount detection means R PM accumulation amount per unit time within a predetermined time J Engine operating time until manual regeneration J1 Manual Time required for PM removal after regeneration S PM removal amount per unit time for manual regeneration H Post injection integration amount 46b Diesel particulate filter (DPF)
53 Deposit amount detection means (downstream pressure sensor)
58 Deposit amount detection means (upstream pressure sensor)
68 Display means (meter panel)

Claims (4)

  In a work vehicle equipped with a diesel engine equipped with a diesel particulate filter (46b) for collecting particulate matter (PM) in exhaust gas, the amount of particulate matter (PM) deposited in the diesel particulate filter (46b) The accumulation amount detection means (58, 53) for detecting the accumulation amount is provided, and the accumulation amount (P2) detected by the accumulation amount detection means (58, 53) is displayed on the display means (68) of the work vehicle. A working vehicle characterized by   The PM accumulation amount per unit time (R) within the past predetermined time during engine operation and the PM amount (P) that can be accumulated in the diesel particulate filter (46b) are calculated from this, and operation until manual regeneration is possible. The work vehicle according to claim 1, characterized in that the time (J) is calculated and displayed on the display means (68).   The amount of particulate matter (PM) removed per unit time (S) when manual regeneration of the diesel particulate filter (46b) is performed, and the amount of particulate matter (PM) detected by the accumulation amount detection means (58, 53). The time (J1) required for removing the granulated material (PM) is calculated from the state of the accumulation amount (P2) and calculated, and displayed on the display means (68). The work vehicle according to claim 1 or claim 2.   The post-injection integrated amount (H) of the post-injection amount that is performed at the time of regeneration of the diesel particulate filter (46b) is calculated. 4. The work vehicle according to claim 3, wherein the work vehicle is configured to display on the means (68).

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