JP2009132310A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily suppress fuel consumption amount by using a changeover switch. <P>SOLUTION: In this working vehicle, an engine E provided with a common rail 1 is mounted. The working vehicle is provided with a normal mode line L1 of a full load condition on a performance curve showing the relation of engine speed and an output, an economy mode line L2 of a full load condition in which rated rotation is lowered and a rated output is lowered in relation to the normal mode line L1, and the changeover switch SW for switching the normal mode line L1 and the economy mode line L2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work vehicle equipped with an engine having a common rail.

In an engine equipped with a common rail, there is a technology for changing the common rail pressure and the fuel injection amount according to the engine load factor. When the load factor decreases, the common rail pressure is lowered to increase the fuel injection amount (see, for example, Patent Document 1).
JP 2007-291953 A

In the technology as described above, the amount of fuel used increases.
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, according to the first aspect of the present invention, in the work vehicle equipped with the engine (E) having the common rail (1), the normal mode line (L1) in the full load state is shown on the performance curve indicating the relationship between the engine speed and the output. The normal mode line (L1) and the economy mode line (L2) are provided with the economy mode line (L2) in the full load state in which the rated output is lowered to reduce the rated output. ), And a changeover switch (SW) is provided.

  According to the first aspect of the present invention, the engine is switched between the normal mode line (L1) and the economy mode line (L2) in which the rated output is reduced by operating the changeover switch (SW).

According to a second aspect of the present invention, the changeover switch (SW) is provided on a handle (16) of the work vehicle.
The operation of the second aspect is switched by the selector switch (SW) of the handle (16).

  Since the present invention is configured as described above, in the invention according to claim 1, as in the economy mode of the line (L2), the economy mode is a full load curve in a state where the rated output is lowered by lowering the rated rotational speed. By providing the fuel consumption rate is improved. In addition, since the vehicle speed is inevitably reduced, less output is required, and the fuel consumption is also reduced. The switching between the line (L1) and the line (L2) is facilitated by performing the switching with a dedicated switch (SW).

  In the invention according to claim 2, since the changeover switch (SW) is provided on the handle (16) of the work vehicle, the changeover switch (SW) can be switched while operating the handle (16) without releasing the handle (16). Operation becomes possible.

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 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.

  Further, 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 interposed therebetween, 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 one of the low speed, medium speed, high speed and neutral positions is located behind the main transmission lever 26. 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.

  In a tractor equipped with the diesel engine E having the common rail 1, a mode in which the rated rotational speed is lowered than in the normal mode and the work can be performed with another full load curve that uses a region with a good fuel consumption rate. (Economy mode) is provided.

  FIG. 5 shows a performance curve of the engine speed and output (torque) showing such a state. The line L1 is a performance curve in a normal state, and the line L2 is a performance curve in the economy mode. As in the economy mode of the line L2, the fuel consumption rate is improved by providing an economy mode that is a full load curve in a state where the rated output is lowered and the rated output is lowered. In addition, since the vehicle speed is inevitably reduced, less output is required, and the fuel consumption is also reduced. Further, the switching between the line L1 and the line L2 is performed by using a dedicated changeover switch SW, thereby facilitating the operation. As shown in FIG. 4, the change-over switch SW is provided on the handle 16 of the work vehicle. Thereby, the switching operation can be performed while operating the handle 16 without releasing the hand from the handle 16.

  Further, in the above-described economy mode, a diesel engine equipped with a turbo with an intercooler is configured such that the intake air temperature after passing through the intercooler does not exceed approximately 60 ° C. Specifically, the intake air temperature after passing through the intercooler is measured by a temperature sensor, and the accelerator opening is adjusted so that the intake air temperature does not exceed 60 ° C. By reducing the accelerator opening, the engine speed decreases and the vehicle speed decreases, and the lower the boost temperature, the lower the intake temperature after passing through the intercooler. As a result, it is possible to always work in an area where fuel consumption is good, and the fuel consumption is also reduced.

  Also, in order to prevent the intake air temperature after passing through the intercooler from exceeding approximately 60 ° C, the speed of the transmission with the continuously variable transmission is changed to change the vehicle speed, and the engine speed is made constant by isochronous control. You may comprise so that it may hold | maintain. This state is shown in FIG. Thereby, it is possible to always work in an area where fuel consumption is good, and the fuel consumption is reduced.

  As another method, the fuel injection timing and amount in the common rail can be changed by a setting switch. For example, there are a work mode, a road mode, an economy mode, and the like. In the economy mode, the fuel injection timing and amount are corrected in the direction in which the fuel consumption decreases. And control which reduces work implement load is performed.

  For example, an excessive heavy tillage is prevented by controlling the tilling depth in the tilling work of the working machine to a certain amount or less. When overheating occurs, the mode is forcibly shifted to the economy mode.

  In the above-described tractor, when turning in the field, when the steering angle of the handle 16 exceeds a predetermined angle, it is determined that the vehicle is in a turning state, and the engine speed is reduced to a predetermined speed by isochronous control, and the turn is performed. . Then, immediately after the turn, the engine rotational speed is not returned to the original rotational speed, but is returned to approximately 50% of the original rotational speed as the rotary 21 is lowered. And it is set as the structure which returns an engine speed gradually to the original rotation speed (rated) simultaneously with the start of tilling. And it is set as the structure which maintains an engine speed by isochronous control to the original speed after a predetermined time. FIG. 7 shows a relationship diagram between the time series and the engine speed. This makes it possible to prevent engine rotation drop since the load applied first becomes smaller than when starting tilling at a stroke of 100% after the turn is completed. In addition, since the load applied suddenly is reduced, the generation of smoke can be suppressed.

  As indicated by an arrow Y in FIG. 8, the speed variation rate is changed depending on the accelerator opening. As in the line L3, the vehicle speed can be kept constant by configuring the speed fluctuation rate to be small at the time of work (during approximately 100% acceleration). Further, as shown by line L4, when turning (accelerator opening is small), the speed can be smoothly turned by configuring the speed fluctuation rate to be large. Further, at the time of turning, the rotational speed with respect to the accelerator opening may be reduced. This state is shown in FIG.

  As shown in FIG. 10, torque limits 1, 2, and 3 are provided, and this output characteristic can be switched by an automatic or manual selection switch. In the case of automatic, the output characteristics are automatically switched according to information such as the pressure of the diesel particulate filter (DPF) and the exhaust temperature. When the granulated material (PM) is clogged in the DPF and it becomes necessary to regenerate, for example, the pressure on the upstream side of the DPF increases, so that the torque limit 3 is automatically switched based on this pressure information.

  The ECU 100 monitors the fuel injection amount, and automatically raises the vehicle speed (continuously variable transmission mission) when the fuel injection amount is not fully used. This calculation is performed with the load factor. The load factor is the current injection amount (output) / the fuel injection amount at full load (output). When the load factor is 90% or less, the vehicle speed is increased as described above (FIG. 11). As a result, the engine output can be used without waste, and the work speed can be increased. Further, the vehicle speed is reduced when the load factor is 100% or more for a predetermined time or longer (2 seconds).

  A line L5 in FIG. 12 shows a change in engine speed, and a line L6 shows a change in the reduction ratio of the mission. As in the line L5, the engine rotational speed at the beginning of work is maintained at a low rotational speed by isochronous control, and the engine rotational speed is linearly increased by isochronous control when the engine output exceeds a predetermined output. At the same time, the speed reduction ratio of the mission is reduced to keep the vehicle speed constant. Thereby, when the output is low, the fuel consumption can be reduced by using low rotation with good fuel efficiency and increasing the engine rotation when the output increases. Further, since the engine speed is increased before the full load is reached, it is possible to prevent the engine speed from greatly decreasing even if the load is instantaneously applied.

  An arrow 37 in FIG. 13 indicates the flow of exhaust gas exhausted from the engine. An oxidation catalyst (DOC) 35 and a diesel particulate filter (DPF) 36 are provided in the middle of the exhaust gas flow. The DOC35 incombustible material is oxidized, and the DPF 36 collects the granulated material (PM) in the exhaust gas. The functions of the DOC 35 and the DPF 36 are lowered when the temperature is lowered. Therefore, the space 40 is formed by covering the periphery of the DOC 35 and the DPF 36 with the box 38, and the exhaust gas is discharged via the space 40 (arrow 39). As a result, it is possible to prevent functional degradation of the DOC 35 and the DPF 36.

  Further, the pressure in the DPF 36 may be measured to estimate the amount of PM, and whether to perform post injection with respect to the main injection, and when performing post injection, the post injection amount may be determined. Since PM is accumulated when the pressure in the DPF 36 is high, post injection is performed to raise the temperature in the DPF 36 so that the PM is burned off.

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

Overall configuration diagram of accumulator fuel injection system The diagram which shows the relationship between the engine speed and output torque by control mode. Left side view of tractor Top view of tractor The diagram which shows the relationship between an engine speed and output torque. The diagram which shows the relationship between an engine speed and output torque. The figure which shows the relationship between time and an engine speed. The diagram which shows the relationship between an engine speed and output torque. (A) The diagram which shows the relationship between an engine speed and output torque.

(B) The diagram which shows the relationship between an engine speed and output torque.
The diagram which shows the relationship between an engine speed and output torque. The diagram which shows the relationship between an engine speed and output torque. The diagram which shows the relationship between an engine speed and a reduction ratio, and output torque. The figure which shows an oxidation catalyst and a diesel particulate filter.

Explanation of symbols

E Engine 1 Common rail 16 Handle L1 Normal mode line L2 Economy mode line SW selector switch

Claims (2)

  In a work vehicle equipped with an engine (E) equipped with a common rail (1), a normal mode line (L1) in a full load state is provided on a performance curve indicating the relationship between the engine speed and output, and this normal mode line (L1 ) Is provided with an economy mode line (L2) in a full load state in which the rated rotation is lowered to reduce the rated output, and a changeover switch (SW) for switching between the normal mode line (L1) and the economy mode line (L2) is provided. A work vehicle characterized by being provided. The work vehicle according to claim 1, wherein the changeover switch (SW) is provided on a handle (16) of the work vehicle.

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