JP2011094575A - Tractor - Google Patents

Abstract

Since the remaining workable time in the selected standard mode or low fuel consumption mode cannot be recognized, work efficiency is not improved.
In a tractor equipped with an engine E provided with a common rail 1, an ECU 100 for controlling the engine E, and a work implement 21, at least a performance curve indicating the relationship between the engine speed and torque is standardized in the ECU 100. The mode line L1 and the low fuel consumption mode line L2 are configured, and the standard mode line L1 and the low fuel consumption mode line L2 are switched by the fuel consumption mode changing means 36, and the remaining when the standard mode line L1 is selected. The structure of the tractor is characterized in that the workable time and the remaining workable time when the low fuel consumption mode line L2 is selected are displayed on the display means M.
[Selection] Figure 7

Description

  The present invention relates to a tractor that is an agricultural machine.

  Conventionally, a configuration in which the state of a working machine mounted on a machine body is determined and the output of the engine is switched to a standard mode or an energy saving mode is known (for example, see Patent Document 1).

JP 2004-76649 A

  The above-mentioned known technique is a configuration for switching the engine output to the standard mode or the energy saving mode. However, since the remaining workable time is not displayed with the standard mode and the energy saving mode selected, there is a drawback that the work efficiency is not improved.

  An object of the present invention is to eliminate the above-described problems.

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 tractor equipped with an engine (E) having a common rail (1), an ECU (100) for controlling the engine (E), and a work implement (21), an ECU ( 100) includes at least a standard mode line (L1) and a low fuel consumption mode line (L2), and a performance curve indicating the relationship between the engine speed and the torque. The switching to (L2) is performed by the fuel consumption mode changing means (36), and the remaining workable time when the standard mode line (L1) is selected and when the low fuel consumption mode line (L2) is selected. The tractor is characterized in that the remaining workable time is displayed on the display means (M).

Switching to either the standard mode line (L1) or the low fuel consumption mode line (L2) is performed by the fuel consumption mode changing means (36). The remaining working time of the selected standard mode line (L1) or low fuel consumption mode line (L2) is displayed on the display means (M). In the invention according to claim 2, the fuel tank of the tractor is filled. By providing a reset button (37) that is operated when the fuel is in the quantity state, and operating the reset button (37), the remaining fuel amount is calculated from the relationship between the fuel injection amount and the time associated with the operation of the engine (E). The calculation time is displayed on the monitor (M) on each of the standard mode line (L1) and the low fuel consumption mode line (L2), and the remaining fuel amount is also displayed on the display means (M). The tractor according to claim 1, wherein the tractor is provided.

  When the fuel tank is full, the reset button (37) is turned on. From this time, the remaining fuel amount is calculated from the relationship between the fuel injection amount accompanying the operation of the engine (E) and time. The workable time in each of the standard mode line (L1) or the low fuel consumption mode line (L2) and the remaining fuel amount are also displayed on the display means (M).

  Since the present invention is configured as described above, in the invention described in claim 1, since the remaining workable time of the selected standard mode line (L1) or low fuel consumption mode line (L2) can be constantly confirmed, Efficiency will be improved.

  In the invention according to claim 2, in addition to the effect of claim 1, the remaining fuel amount can be calculated with high accuracy from the relationship between the fuel injection amount and time by once resetting the fuel tank when it is full. Become. The remaining fuel amount is also displayed as a numerical value, so that the work efficiency is further 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 Diagram showing the relationship between engine speed and output torque Flow chart for displaying the remaining work time Plan view of display means (monitor) Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and output torque Diagram showing the relationship between engine speed and engine idle load (A) Front view of the engine stored in the bonnet (b) Side view of the engine stored in the bonnet Side view of the engine in the hood

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.

As described above, the common rail 1 injects fuel to each cylinder 5 of the engine E, and supplies the fuel with 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 35 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 / lowers the working machine 21.

  The ECU 100 shown in FIG. 1 is connected to a control device 200 on the machine side. This control device 200 includes a plowing depth setting means (automatic plowing depth lever) 30 for automatically setting the plowing depth of the field, an automatic plowing depth switch 30a for turning on the functions of the plowing depth setting means 30, and a plowing depth. A selection switch (30b) for selecting either priority or vehicle speed priority and a display means (monitor) M are connected. FIG. 4 shows these arrangement positions.

  Then, when the automatic plowing depth switch 30a is in the on state, when the working switch 21 is driven in the state where either the plowing depth priority or the vehicle speed priority is selected by the selection switch 30b, the work traveling is started. The ECU 100 detects the engine load factor and transmits it to the control device 200 on the machine side. The control device 200 calculates the vehicle speed for maintaining the plowing depth or the plowing depth for maintaining the vehicle speed to the monitor M. It is configured to display. The engine load state is detected from the fuel injection state and the engine speed sensor E1, but other means may be used.

  As a result, an appropriate vehicle speed for maintaining the plowing depth or an appropriate plowing depth for maintaining the vehicle speed is displayed on the monitor M, so that good work can be performed without increasing the load on the engine E. In addition, excessive consumption of fuel can be suppressed. In particular, since the common rail 1 is mounted on the engine, fuel injection control for maintaining an appropriate vehicle speed can be performed with high accuracy, and fuel efficiency is improved.

  Further, the load state of the engine E is displayed on the monitor M when the automatic tilling switch 30a is in the cut state. Thus, when the automatic tilling switch 30a is in the off state, the load state of the engine E is displayed on the monitor M, so that the operator can easily check the load state of the engine E, and depending on the situation, the automatic tilling depth With the switch 30a and the selection switch 30b turned on, it is possible to quickly grasp the appropriate vehicle speed for maintaining the tilling depth or the appropriate tilling depth for maintaining the vehicle speed.

  FIG. 5 is a performance curve showing the relationship between the engine speed and the torque. The line L1 indicates the standard mode (power mode), and the line L2 indicates the low fuel consumption mode. The maximum torque point of the standard mode line L1 is T1, and the maximum torque point of the low fuel consumption mode line L2 is T2. The switching selection between the standard mode line L1 and the low fuel consumption mode line L2 is performed by the fuel consumption mode dial 36 (FIG. 4). As a form of the fuel consumption mode dial 36, an on / off type switch (a fuel consumption mode in an on state) or a changeover switch for switching to either one may be used.

  As shown in FIG. 6, when the tractor fuel tank is full, the reset button 37 (FIG. 4) is pushed (S1), and the remaining fuel amount is calculated from the relationship between the fuel injection amount and time associated with the operation of the engine. Calculation (S2, S3) and display (S4). The workable time in each of the standard mode line L1 and the low fuel consumption mode line L2 is displayed on the monitor M (S5). FIG. 7 shows an example of this display. Thereby, it becomes possible to work efficiently in the standard mode line L1 and the low fuel consumption mode line L2.

  When the fuel economy mode dial 36 is not provided, the standard mode line L1 is basically used, and when the engine load factor of 90% or less continues for 10 seconds, the fuel economy mode dial 36 automatically shifts to the fuel efficiency mode line L2. To do. In this case, the standard mode line L1 may be selected by the fuel consumption mode dial 36. And while using the fuel-efficient mode L2, it is set as the structure which returns to the standard mode line L1 automatically at the moment when an engine load factor exceeds 90%. Thereby, fuel consumption can be reduced by actively using the low fuel consumption mode even in a short time, by accumulating the short time.

  Further, when switching to the low fuel consumption mode line L2, the tillering depth of the tractor using the rotary working machine is automatically reduced by a predetermined amount or the PTO rotational speed is reduced. Thereby, fuel consumption comes to improve further. However, a switch or the like for checking the function may be provided for an operator who does not want to reduce the tillage depth or decelerate the PTO rotation speed. Further, when the mode is switched to the low fuel consumption mode line L2, the main speed change and the sub speed change may be automatically decelerated to reduce the vehicle speed. Even in this case, a switch or the like for checking such a function may be provided.

  FIG. 8 shows a configuration in which a plurality of performance curves (three lines in the embodiment) are provided. The output characteristic curves L3, L4, and L5 are automatically switched according to the engine speed. In other words, when the engine speed is below a specific threshold, the output characteristic curve of the higher output is sequentially shifted. On the other hand, when the engine speed exceeds the threshold value, the output characteristic curve of the lower output is sequentially shifted. The operator can arbitrarily set the presence or absence of the output characteristic curve transition and the threshold value of the engine speed for the transition. Since the fuel efficiency output characteristic curve is selected autonomously, fuel consumption can be suppressed.

  FIG. 9 shows the electronic governor characteristics. P1 is the lowest fuel consumption point, and L6 is the full load performance characteristic. L7 represents a conventional governor characteristic, and L8 represents a new governor characteristic.

  Fuel consumption characteristics according to engine operating conditions determined from engine specific fuel consumption per unit time / unit output (g / ps · h) and fuel consumption characteristics are set on an equal fuel consumption curve. For the full load performance, the governor characteristic was conventionally linear (L7). On the other hand, by controlling the governor characteristic toward the full load so as to pass through a region with better fuel efficiency on the iso-fuel consumption curve, it becomes possible to improve the fuel efficiency at the partial load. The fuel consumption can be improved without deteriorating the practical performance.

  FIG. 10 shows control related to switching between droop control and isochronous control. The governor mode is droop characteristic L10 on the full load performance characteristic L9 region of the engine. When the engine is operated under an arbitrary load condition with the accelerator opening (a%), the governor mode is isochronous in this state. When switching to the characteristic L11, a speed drop (b) occurs.

  Therefore, assuming that the current operation point is P2, the speed drop (b0) is predicted by holding a predicted speed drop according to the load factor at the time of switching as a map. The target value for isochronous control is changed based on the predicted value (b0). In FIG. 10, the isochronous characteristic is changed from L11 to L12. As a result, the governor mode can be switched in a state where there is no drop in the engine speed. An instruction value (n) of the engine speed of the changed isochronous characteristic is stored, and the isochronous control is performed based on the n speed.

  FIG. 12 shows a method for calculating the load factor. L13 indicates the full load characteristic. If currently operating at a point P3 in a region exceeding the rated speed, the load factor at that speed is calculated as a ratio to the point P5. However, in reality, when the engine load is applied from the state of the point P3, the load becomes the full load (100% load factor) at the point P4, which is greatly different from the load factor for the point P5. For this reason, it cannot be used for control such as work load reduction and vehicle speed reduction.

  Therefore, by giving a virtual full load characteristic as indicated by the broken line L14 on the high speed side from the rated point P7, and calculating the load factor for the point P6 on the virtual full load characteristic L14, the control by the load factor closer to the actual situation is performed. Is possible.

  FIG. 13 is a configuration that improves the accuracy of the configuration of FIG. 12 described above. That is, the point P6 in FIG. 12 is brought close to the point P4. Currently, the load factor for the point P6 is calculated by the virtual full load performance characteristic L14 in the state of operating at the point P3 in the region exceeding the rated speed, but the full load performance for the point P3 is actually the point P11. Which is different from that calculated at point P6. Even in the case of driving at the point P8, an error occurs because the point P4 is 100% of the load factor, not the point P6 of the virtual total load characteristic L14.

  Therefore, the difference between the point P5 and the point P3 is (α), the difference between the point P5 and the point P8 is (β), a correction amount is calculated from the (α) and (β), and the correction amount is virtually calculated. By calculating the load factor with the values P10 and P9 of the respective values added to the point P6 on the total load characteristic L14 as 100%, highly accurate control is possible.

  The output T configuration in FIG. 14 shows idle load control. In an engine (electronic governor) that performs rotation and load control by electronic control, when the load factor is increased at low idle, the engine load increases from a certain engine load point until the load factor is constant, and the engine load increases. Control is performed to increase the rotational speed, and the idle load characteristics are improved. As a result, the engine output increases from a certain point as the engine speed increases, which is effective for loader work that uses a foot pedal or the like. In addition, operation characteristics such as idle start are improved.

  FIG. 15A is a front view in which a diesel engine is mounted in the hood 38 of the tractor, and FIG. 15B is a left side view thereof. Reference numeral 39 denotes a diesel particulate filter (DPF) that removes the particulate matter (PM) in the exhaust gas. Reference numeral 41 denotes a cooling fan for generating cooling air. The DPF 39 is mounted on the engine E in the direction perpendicular to the longitudinal direction of the vehicle body. A semi-cylindrical heat shield plate 40 is arranged in a substantially lower half of the DPF 39.

  The cooling air generated from the cooling fan 41 does not directly hit the DPF 39 but flows along the heat shield plate 40. And it is set as the structure from which the cooling air comes out from the slit 42 provided in the back upper side surface of the bonnet 38. FIG. Thereby, since the cooling air does not directly hit the DPF 39, the temperature inside the DPF 39 can be maintained at a high temperature, and the combustion of the PM collected in the DPF 39 is promoted.

  Since the cooling air flows outside the heat shield plate 40 and is discharged from the slit 42 of the bonnet 38, it is possible to prevent thermal damage to peripheral components due to heat generated during forced regeneration of the DPF 39. About the said slit 42, you may comprise so that it may provide in the back upper part of the bonnet 38 as another slit 42a.

  Further, as shown in FIG. 16, a cooling air guide plate 43 may be provided behind the DPF 39. The guide plate 43 smoothly guides the cooling air toward the slit 42b. In particular, the position of the slit 42b is slightly different from the positions of the slits 42 and 42a in FIG. That is, the position of the slit 42b shown in FIG. 16 is an upper position of the bonnet 38 and a position where the cooling air guided by the guide plate 43 hits. Thereby, the discharge efficiency of the cooling air to the outside of the machine is improved.

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

1 Common rail 21 Work implement 36 Fuel consumption mode change means (Fuel consumption mode dial)
37 Reset button 100 ECU
E Engine L1 Standard mode line L2 Fuel efficient mode line M Display means (monitor)

Claims (2)

  In a tractor equipped with an engine (E) having a common rail (1), an ECU (100) for controlling the engine (E), and a work implement (21), the engine speed and torque are included in the ECU (100). The performance curve indicating the relationship between the standard mode line (L1) and the low fuel consumption mode line (L2) is configured, and switching between the standard mode line (L1) and the low fuel consumption mode line (L2) changes the fuel consumption mode. The means (36) is configured to display the remaining workable time when the standard mode line (L1) is selected and the remaining workable time when the low fuel consumption mode line (L2) is selected. A tractor characterized by being displayed on the screen.   A reset button (37) that is operated when the fuel tank of the tractor is in a full state is provided. By operating the reset button (37), the relationship between the fuel injection amount associated with the operation of the engine (E) and time The remaining fuel amount is calculated from the standard mode line (L1) and the fuel efficient mode line (L2), and the remaining work amount is displayed on the monitor (M). The remaining fuel amount is also displayed on the display means (M). The tractor according to claim 1, wherein the tractor is configured to be displayed on the screen.

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