JP2017015060A - Tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tractor capable of achieving low fuel consumption or a low noise property according to an individual situation.SOLUTION: An ECU, which an engine of a tractor has, stores beforehand a first injection control map which indicates a fuel injection state of preferentially suppressing fuel consumption by a relation between an engine rotation speed and output torque, and a second injection control map which indicates a fuel injection state of preferentially suppressing noise by a relation between the engine rotation speed and the output torque. The ECU, based on information acquired from the engine and information acquired from a vehicle body of the tractor, specifies the kind or state of a work machine connected to the tractor (steps S102-S104). Further, the ECU, according to the kind or state of the work machine, automatically selects either injection control map and controls the engine based on the selected injection control map (steps S105, S106, S108).SELECTED DRAWING: Figure 9

Description

  The present invention relates to a tractor. Specifically, the present invention relates to a configuration for automatically and appropriately controlling an engine that is a driving source of the tractor according to at least one of the type and state of the work machine connected to the tractor.

  2. Description of the Related Art Conventionally, a configuration is known in which output torque characteristics of an engine serving as a drive source are switched according to a change in a work environment of a tractor so that the control of the engine is appropriate for each work environment. Patent document 1 discloses this kind of tractor.

  The tractor of Patent Literature 1 stores a plurality of performance curves (specifically, a high torque line and a low fuel consumption line) indicating the relationship between the engine speed and the output torque in the engine control unit in advance. Patent Document 1 does not disclose how to select a high torque line or a low fuel consumption line, but it is possible to select any one by an appropriate operation of the operator. Conceivable. In the tractor of Patent Document 1, it is considered that the output torque of the engine can be appropriately controlled by appropriately selecting the high torque line or the low fuel consumption line by the operator.

JP 2011-12562 A

  By the way, in the engine of a tractor like patent document 1, as mentioned above, although control is performed about the output torque using several performance curves, about a fuel-injection state, an engine speed and output torque are used. In general, control is performed based on a single injection control information indicating the fuel injection state. In that case, in consideration of the fact that there is a trade-off between improving the fuel consumption of the engine and reducing the noise, it is possible to realize a fuel injection state that can provide a reasonable low fuel consumption and low noise. Control information is adopted. However, depending on the type or state of the work implement, there are cases where it is desired to suppress the fuel consumption even if the noise is somewhat increased, or conversely, it is desired to reduce the noise even if the fuel efficiency is somewhat deteriorated. When the fuel injection state of the tractor engine is controlled using a single injection control information, appropriate control cannot be performed according to the type or state of each work implement in such a case, and there is room for improvement. was there.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to automatically and appropriately control the fuel injection state of an engine, which is a drive source of a tractor, to reduce the fuel efficiency or noise of the engine. It is to provide a tractor that can be realized according to individual circumstances.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to an aspect of the present invention, a tractor having the following configuration is provided. That is, the tractor includes an engine as a driving source and an engine control unit that controls the engine, and can connect any of a plurality of work machines. The engine control unit stores in advance first injection control information and second injection control information. The first injection control information indicates a fuel injection state in which priority is given to suppressing fuel consumption in a relationship between the engine speed and the output torque. The second injection control information indicates a fuel injection state in which priority is given to suppressing noise in a relationship between the engine speed and the output torque. The engine control unit identifies at least one of a type or a state of the connected work implement based on information acquired from the engine and information acquired from a vehicle body of the tractor. The engine control unit automatically selects either the first injection control information or the second injection control information according to the type or state of the work implement, and based on the selected injection control information Control the engine.

  As a result, depending on the type or state of the work implement, either the control giving priority to suppressing fuel consumption or the control giving priority to suppressing noise is automatically selected and fuel injection is performed. Control can be performed so that the state is appropriate for each situation.

  The tractor preferably has the following configuration. That is, the engine control unit stores first speed control information and second speed control information in advance. The first speed control information indicates a control gain of engine speed control giving priority to increasing responsiveness to fluctuations in engine speed in relation to the output torque. The second speed control information indicates a control gain of engine speed control giving priority to maintaining high stability of the engine speed in a steady state in relation to the output torque. The engine control unit automatically selects either the first speed control information or the second speed control information according to the type or state of the work implement, and the selected speed control information The engine is controlled so that the engine speed is regulated based on the engine speed.

  As a result, depending on the type or state of the work implement, priority was given to control that prioritizes maintaining high stability of the engine speed during steady operation, or priority was given to increasing responsiveness to fluctuations in engine speed. It is possible to automatically select one of the control and perform control so that the control gain of the engine speed control becomes appropriate according to each situation.

  The tractor preferably includes an operation tool that allows an operator to select either the first injection control information or the second injection control information.

  This allows the operator to manually switch between control that prioritizes reducing fuel consumption or control that prioritizes suppressing noise, and responds flexibly to changes in the work environment of the tractor. can do.

  The tractor preferably has the following configuration. That is, the engine includes an EGR device that recirculates the exhaust gas corresponding to the EGR rate to the intake side. Different EGR rates are set for the case where the engine is controlled based on the first injection control information and the case where the engine is controlled based on the second injection control information.

  As a result, the EGR rate can be varied depending on whether priority is given to suppressing fuel consumption or priority on suppressing noise, and engine control can be performed more appropriately in accordance with individual situations.

The side view which shows the whole structure of the tractor which concerns on one Embodiment of this invention. The figure which showed typically the structure of the engine mounted in a tractor. The block diagram which shows the main electrical structures of a tractor. The torque diagram of the engine of a tractor. Explanatory drawing which shows the injection control map and speed control map which are selected according to the operation | work / state of a tractor in automatic mode. The figure which shows the control map of the fuel injection pressure each contained in the 1st injection control map and the 2nd injection control map. The figure which shows the control map of the fuel-injection pattern each contained in the 1st injection control map and the 2nd injection map. The figure explaining the behavior of an engine speed in each case of the high responsiveness mode and the steady stability mode at the time of acceleration and steady state. The flowchart which shows the control which ECU performs. The figure which shows the specific example of the work content specific information memorize | stored in ECU.

  Next, embodiments of the present invention will be described with reference to the drawings. First, the basic configuration of the tractor 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a side view showing an overall configuration of a tractor 1 according to an embodiment of the present invention.

  The tractor 1 is a work vehicle for agricultural work, and can be equipped with various work machines (attachments) such as a rotary and a harrow as necessary to perform various work using the work machine.

  The tractor 1 includes a vehicle body 2, a pair of left and right front wheels 3, and a pair of left and right rear wheels 4. A bonnet 5 is disposed at the front of the vehicle body 2, and an engine 6 that is a drive source of the tractor 1 is disposed inside the bonnet 5.

  A mission case 7 is disposed between the left and right rear wheels 4. The output of the engine 6 is changed by the transmission mechanism in the transmission case 7 and transmitted to the rear wheel 4 and the work machine. More specifically, a part of the output of the engine 6 is appropriately shifted by a main transmission mechanism and an auxiliary transmission mechanism (not shown) disposed in the mission case 7 and transmitted to the rear wheel 4. Further, the remaining part of the output of the engine 6 is appropriately shifted by a PTO transmission mechanism (not shown) disposed in the mission case 7 and transmitted to the PTO shaft 9.

  A lower link 13, a top link 14, and a PTO shaft 9 are disposed at the rear part of the mission case 7. The work machine is connected to the lower link 13 and the top link 14 and is driven by the PTO shaft 9.

  A cabin 15 for an operator to board is disposed above the mission case 7 and behind the bonnet 5. A driver seat is provided inside the cabin 15, and a plurality of operating tools (not shown) for operation by an operator are provided in the vicinity of the driver seat.

  Next, a basic configuration of the engine 6 that is a drive source of the tractor 1 will be described with reference to FIG. FIG. 2 is a diagram schematically showing the configuration of the engine 6 mounted on the tractor 1.

  As shown in FIG. 2, the engine 6 includes an engine main body 18, a fuel injection device 19, an EGR device (exhaust gas recirculation device) 20, an exhaust turbine supercharger 21, an exhaust purification device 22, ECU (engine control unit) 17 as an engine control unit.

  In the present embodiment, the engine 6 is configured as an in-line four-cylinder diesel engine. The engine body 18 includes a cylinder block and a cylinder head. Four cylinders 33 are formed in the cylinder block. A combustion chamber is formed inside each cylinder 33, and a piston (not shown) is slidably disposed. This piston is connected to a crankshaft (not shown) that is an output shaft of the engine 6.

  The engine main body 18 includes an intake manifold 23 and an exhaust manifold 24. An intake pipe 25 that introduces intake air to the intake manifold 23 is connected to the intake manifold 23. An exhaust pipe 26 through which exhaust from the exhaust manifold 24 is discharged is connected to the exhaust manifold 24.

  The fuel injection device 19 includes an injector 27 corresponding to each cylinder 33. The fuel that is pumped by a fuel pump (not shown) is distributed to the injector 27 via a common rail (not shown). The electronic control valve included in the injector 27 is electrically connected to the ECU 17, and fuel is injected from the injector 27 into the combustion chamber when a signal from the ECU 17 is input to the electronic control valve. The ECU 17 controls the fuel injection timing from the injector 27, the injection pressure (the pressure of the common rail), and the injection pattern.

  The EGR device 20 includes an EGR pipe 28, an EGR valve 29, and an EGR cooler 30. The EGR pipe 28 connects the intake pipe 25 and the exhaust pipe 26, and the exhaust gas is recirculated to the intake air via the EGR pipe 28. The EGR valve 29 is provided inside the EGR pipe 28, and the EGR valve 29 is electrically connected to the ECU 17. By controlling the opening degree of the EGR valve 29 by the ECU 17, the rate of exhaust gas recirculated to the intake side of the exhaust gas (hereinafter referred to as “EGR rate”) is adjusted. The EGR cooler 30 cools the exhaust gas flowing through the EGR pipe 28.

  The supercharger 21 includes a turbine 31 that is rotated by exhaust flowing through the exhaust pipe 26, and a compressor 32 that rotates integrally with the turbine 31. The compressor 32 is disposed in the intake pipe 25, and the intake air is compressed by the rotation of the compressor 32 and sent into the cylinder 33 of the engine body 18.

  The exhaust purification device 22 is provided at the outlet of the exhaust pipe 26. The exhaust purification device 22 includes a DOC (diesel oxidation catalyst) and a DPF (diesel particulate filter). The exhaust gas is purified by passing through the exhaust purification device 22 and then discharged to the outside.

  Next, a configuration related to the control of the engine 6 will be described with reference to FIG. FIG. 3 is a block diagram showing the main electrical configuration of the tractor 1.

  The ECU 17 as an engine control unit is configured as a computer including a CPU, a ROM, a RAM, and the like. The ECU 17 acquires information from various sensors and operating tools shown in FIG. 3 and performs control related to the engine 6 based on these information.

  This will be specifically described below. The auxiliary transmission mechanism included in the vehicle body 2 of the tractor 1 is provided with an auxiliary transmission sensor 10 that detects the shift speed of the auxiliary transmission mechanism. Further, the PTO transmission mechanism is provided with a PTO speed sensor 11 for detecting a gear position of the PTO transmission mechanism. Further, a vehicle speed sensor 12 that detects the vehicle speed of the tractor 1 is provided at an appropriate position on the drive transmission path from the engine 6 to the rear wheel 4. The auxiliary transmission sensor 10, the PTO speed sensor 11, and the vehicle speed sensor 12 are electrically connected to the ECU 17.

  The above-described operation tool included in the vehicle body 2 (specifically, disposed inside the cabin 15) includes a mode switching operation tool 16. The mode switching operation tool 16 is operated by the operator to switch the control mode of the engine 6 to any one of “manual mode” and “automatic mode” described later. The mode switching operation tool 16 is electrically connected to the ECU 17.

  The engine body 18 is provided with an engine speed sensor 34 that detects the engine speed and a torque detection sensor 35 that detects the output torque of the engine. The engine speed sensor 34 and the torque detection sensor 35 are electrically connected to the ECU 17.

  As described above, the tractor 1 of the present embodiment can be operated by connecting various working machines such as a rotary and a harrow. Should control be performed with priority on low fuel consumption rather than low noise? The control that prioritizes low noise over low fuel consumption depends on the work or state of the tractor 1 (that is, what kind of work machine is connected to the tractor 1, what kind of work is being performed, and the tractor 1). Depending on the state).

  By the way, the torque-rotation speed region mainly used in the engine 6 differs depending on the operation / state of the tractor 1. In FIG. 4, when the tractor 1 performs various work (for example, tilling work, plowing work, etc.), the high-idle state, the low-idle state, etc., the torque-rotation speed region is the engine of the tractor 1. 6 is superimposed on the torque diagram. In the following description, in order to simplify the notation, various operations / states of the tractor 1 may be expressed by abbreviations using alphabets such as “operation A”, “state H / I”, and the like. .

  As described above, since the torque-rotation speed region varies depending on the operation / state of the tractor 1, it is based on the engine speed detected by the engine speed sensor 34 and the output torque detected by the torque detection sensor 35. Thus, it is considered possible to specify the work / state of the tractor 1 to some extent and select and control which of the low noise and the low fuel consumption should be given priority based on this.

  However, even if the work / state of the tractor 1 is different, the torque-rotation speed region used may be similar to each other. Specifically, as illustrated in FIG. 4, for example, the work A and the work C partially overlap with each other, and the work E and the work F partially overlap. Therefore, as described above, the work / state of the tractor 1 cannot be accurately specified only by the information acquired from the engine, and it may not be possible to perform control suitable for the needs.

  Therefore, the tractor 1 of the present embodiment is configured to specify the work / state of the tractor 1 by considering information acquired from the vehicle body 2 in addition to information acquired from the engine 6 as a determination material. Thereby, since the information regarding the work / state of the tractor 1 can be acquired accurately, appropriate control according to the situation can be performed.

  The needs required for engine control vary depending on the situation, but as a general trend, in most of the work performed on the field (work A, work B, work C, work D, and work F), Considering work in a vast field, it is important to keep fuel consumption low. On the other hand, when it is assumed that there is an operator in the vicinity of the engine 6 (operation E, state H / I, and state L / I), it is important to reduce noise from the viewpoint of improving the working environment. The

  Therefore, the tractor 1 of the present embodiment is configured such that the operator can select the “automatic mode” by operating the mode switching operation tool 16. This automatic mode automatically selects one of the low fuel consumption mode prioritizing low fuel consumption over low noise and the low noise mode prioritizing low noise over low fuel consumption based on information on the work / state of the tractor 1. To select and control.

  This will be specifically described below. In the present embodiment, for each possible work / state of the tractor 1, any of the fuel-efficient mode and the low-noise mode, which is generally preferable, is determined as a standard setting for fuel injection control. Specifically, in consideration of the above circumstances, a fuel-efficient mode is assigned as a standard setting for work A, work B, work C, work D, and work F, and work E, state H / I, and A low noise mode is assigned as a standard setting to the state L / I. In FIG. 5, for each operation / state, a mode assigned as a standard setting for the fuel injection control is indicated by a solid frame. When the “automatic mode” is selected, the fuel injection control in the low fuel consumption mode or the low noise mode is performed according to the mode set as the standard setting.

  However, even if it is an operation that usually prioritizes keeping fuel consumption low, there may be a case where the workplace is in the vicinity of a house and priority is given to reducing noise. Or, even if it is an operation that is usually prioritized to suppress noise, there may be a case where it is desirable to emphasize fuel consumption when the operation time is long.

  Therefore, in the tractor 1 of the present embodiment, the “manual mode” in which the mode is manually specified can be selected by the operator operating the mode switching operation tool 16. When “manual mode” is selected, by further operating another operation tool (not shown), in the case of the work A, the work B, the work D, or the work F, the low fuel consumption that is a standard setting It is also possible to specify that the control is performed in the low noise mode instead of the mode. When “manual mode” is selected, the control is performed in the low fuel consumption mode instead of the standard low noise mode in the case of the work E, the state H / I, or the state L / I. Can also be specified. In FIG. 5, modes that can be set in the manual mode with respect to the fuel injection control for each operation / state are indicated by broken-line frames.

  And in this embodiment, in order to implement | achieve the fuel-injection state according to each condition as mentioned above, in ECU17 of the tractor 1, the injection control map (1st injection) as the following two types of injection control information A control map M1 and a second injection control map M2) are stored in advance. The ECU 17 controls the two types of injection control maps depending on whether priority is given to suppressing fuel consumption or priority to suppressing noise.

  The first injection control map M1 shows the fuel injection timing, the fuel injection pressure, and the fuel injection pattern that should be targeted when priority is given to suppressing fuel consumption, in relation to the engine speed and the output torque. is there. Specifically, the fuel injection timing of the first injection control map M1 is set to a timing slightly delayed from the crank angle position at the compression top dead center of the piston. The first injection control map M1 includes a fuel injection pressure control map (FIG. 6A). This fuel injection pressure is a fuel injection pressure control map of a second injection control map M2 described later. Is set to a relatively high value. By bringing the fuel injection timing and fuel injection pressure close to the target fuel injection timing and fuel injection pressure as described above, an explosion can be caused with a small amount of fuel, and fuel consumption can be suppressed. The first injection control map M1 includes a fuel injection pattern control map (FIG. 7A). This fuel injection pattern is single injection when the load is large, while the load is small. In this case, the multi-injection is set. Thus, fuel consumption can be suppressed by reducing the number of times of fuel injection at high load.

  On the other hand, the second injection control map M2 indicates the fuel injection timing, the fuel injection pressure, and the fuel injection pattern that should be targeted when priority is given to suppressing noise in relation to the engine speed and the output torque. Is. Specifically, the fuel injection timing of the second injection control map M2 is set to a timing delayed somewhat from the crank angle position at the compression top dead center of the piston. That is, the fuel injection timing of the second injection control map M2 is set to a timing delayed from the fuel injection timing of the first injection control map M1. The second injection control map M2 includes a fuel injection pressure control map (FIG. 6B), which is higher than the fuel injection pressure control map of the first injection control map M1. It is set to a relatively low value. By bringing the fuel injection timing closer to the target fuel injection timing and the fuel injection pressure as described above, the pressure in the cylinder 33 is reduced, so that combustion can be suppressed and noise can be suppressed. Further, the second injection control map M2 includes a fuel injection pattern control map (FIG. 7B), and this fuel injection pattern is set to multi-injection both when the load is large and small. Is set to In this way, by using multi-injection regardless of the load, explosion sound can be suppressed and noise can be reduced.

  Regarding the speed control of the engine speed, whether the priority should be given to the responsiveness to fluctuations in the engine speed or the stable speed of the engine speed in the steady state should be determined by the work implement connected to the tractor 1. It depends on the type or condition. In general, it is important to increase the responsiveness to fluctuations in the engine speed for work with large load fluctuations, while maintaining stability of the engine speed in a steady state during light load work and the like. Emphasized. Therefore, in the tractor 1 of the present embodiment, priority is given to increasing the responsiveness to fluctuations in the engine speed as a standard setting for speed control for the work A, the work C, the work D, and the work F. Control (high response mode) is assigned. On the other hand, for work B, work E, state H / I, and state L / I, as a standard setting for speed control, priority is given to maintaining high stability of the engine speed in a steady state ( Steady stability mode) is assigned.

  Although FIG. 5 does not illustrate manual selection of the mode related to speed control, when the mode switching operation tool 16 is set to the “manual mode”, the high-responsiveness mode and the steady state are set regardless of the standard setting. The stability mode can be selected and specified by another operation tool or the like.

  In order to realize high responsiveness or steady stability of the engine speed according to each situation, the ECU 17 of the tractor 1 has a speed control map (first speed control) as the following two types of speed control information. Map and second governing control map) are stored. The ECU 17 uses the two types of speed control maps depending on whether priority is given to increasing the responsiveness to fluctuations in engine speed or priority is given to maintaining high stability of the engine speed during steady state. Control.

  Hereinafter, the two speed control maps will be described with reference to the graph of FIG. In the graphs of FIGS. 8 (a) and 8 (b), the temporal change of the engine speed during engine rotation acceleration and steady state is shown for each of the speed control maps.

  The first speed control map shows the control gain of engine speed control that is targeted when priority is given to increasing the responsiveness to fluctuations in engine speed in relation to the output torque. The control gain of the first speed control map is set to a relatively high value so as to realize the behavior of the engine speed as shown by the solid line in the graph of FIG. As a result, the engine speed can reach the target speed in a short time when the engine is started or when the load fluctuates.

  The second governing control map shows the control gain of the engine speed control that is targeted when priority is given to maintaining high stability of the engine speed in a steady state in relation to the output torque. is there. The control gain of the second speed control map is set to a relatively low value so as to realize the behavior of the engine speed as indicated by the broken line in the graph of FIG. As a result, the difference between the target engine speed and the actual engine speed during normal operation is reduced, and the stability during normal operation of the engine can be maintained high.

  Next, specific processing performed by the tractor 1 of the present embodiment will be described. FIG. 9 is a flowchart showing the control performed by the ECU 17. Note that the flow shown in FIG. 9 is repeatedly executed at appropriate time intervals.

  First, the ECU 17 detects whether an “automatic mode” is selected by detecting an output signal from the mode switching operation tool 16 (step S101). As a result, when “manual mode” is selected instead of “automatic mode”, the ECU 17 performs control in the low fuel consumption mode or the low noise mode in accordance with the mode selected by the other operation tool described above. Then, control in the high response mode or the steady stability mode is performed (step S201).

  When “automatic mode” is selected, the ECU 17 acquires information from the engine 6 (step S102). Specifically, the ECU 17 of the present embodiment acquires the engine speed by detecting an output signal from the engine speed sensor.

  Moreover, ECU17 acquires the information from the vehicle body 2 of the tractor 1 (step S103). Specifically, the ECU 17 detects an output signal from the auxiliary transmission sensor 10 to detect a gear position of the auxiliary transmission mechanism. Further, the shift stage of the PTO transmission mechanism is detected by detecting an output signal from the PTO speed sensor 11. Further, the vehicle speed of the tractor 1 is detected by detecting an output signal from the vehicle speed sensor 12.

  Subsequently, the ECU 17 specifies the work / state of the tractor 1 by collating the information acquired in steps S102 and S103 with the work / state specifying information shown in FIG. 10 (step S104). The work / state specifying information includes each work or state (work A to work F, state H / I, state L / I), engine speed, sub-speed, and speed stage of the PTO transmission mechanism (PTO speed stage). ) And the vehicle speed of the vehicle body 2 are associated with each other and stored in the ECU 17 in advance. As described above, in the tractor 1 of the present embodiment, the ECU 17 uses the information acquired from the vehicle body 2 of the tractor 1 in addition to the information acquired from the engine 6, so that the operation / state of the tractor 1 (in other words, the tractor 1 The type and state of the work equipment connected to the machine. Thereby, even when there are a plurality of work / states in which the torque-rotation speed regions overlap each other, the work / state of the tractor 1 can be obtained accurately.

  After specifying the type and state of the work implement, the ECU 17 determines whether or not the low fuel consumption mode is set as the standard setting for the specified operation / state of the tractor 1 (step S105). Specifically, the ECU 17 determines whether the work / state of the tractor 1 identified in step S104 is work A, work B, work C, work D, or work F. When it is determined that the standard setting for the work / state of the identified tractor 1 is the low fuel consumption mode, the ECU 17 determines the fuel based on the first injection control map M1 that is an injection control map for realizing the low fuel consumption. The injection state is controlled (step S106). That is, the ECU 17 transmits a signal to the injector 27 so that the fuel injection state from the injector 27 approaches the target fuel injection timing, fuel injection pressure, and fuel injection pattern obtained from the first injection control map M1. Thereby, fuel consumption is improved. Further, the ECU 17 sets the EGR rate to a relatively high value in order to further reduce fuel consumption, and sets the EGR valve 29 so that the opening degree of the EGR valve 29 becomes an opening degree that realizes the EGR rate. A signal is transmitted (step S107). As a result, the amount of exhaust gas circulated to the intake side increases, and fuel efficiency is further improved.

  If it is determined in step S105 that the standard setting for the work / state of the identified tractor 1 is not the fuel-efficient mode (in other words, the type and state of the work implement identified in step S104 is the work E, state H / I or when it is determined to correspond to the state L / I) means that the standard setting for the work / state of the identified tractor 1 is the low noise mode. In this case, the ECU 17 controls the fuel injection state based on the second injection control map M2, which is an injection control map for realizing low noise (step S108). That is, the ECU 17 transmits a signal to the injector 27 so that the fuel injection state from the injector 27 approaches the target fuel injection timing, fuel injection pressure, and fuel injection pattern obtained from the second injection control map M2. Thereby, noise is reduced. Further, the ECU 17 sets the EGR rate to a value relatively lower than the value set in step S107 in order to further suppress noise, and the opening degree at which the opening degree of the EGR valve 29 realizes the EGR ratio. Thus, a signal is transmitted to the EGR valve 29 (step S109). As a result, the amount of exhaust gas circulated to the intake side is reduced or no longer circulated, so that noise is further improved.

  After controlling the EGR rate in step S107 or step S109, the ECU 17 determines whether or not the standard setting for the work / state of the specified tractor 1 is the high-responsiveness mode (step S110). Specifically, the ECU 17 determines whether or not the work / state of the tractor 1 identified in step S104 is work A, work C, work D, or work F.

  When the high responsiveness mode is defined as the standard setting for the work / state of the specified tractor 1, the ECU 17 is a first speed control map that is a speed control map for realizing high responsiveness. The engine speed is adjusted based on As a result, the engine speed is controlled with a relatively high control gain, so that the responsiveness to fluctuations in the engine speed can be increased as shown in the “high response mode” of FIG.

  When it is determined in step S110 that the standard setting for the work / state of the specified tractor 1 is not the high-responsiveness mode (in other words, the work / state of the tractor 1 specified in step S104 is the work B , Operation E, state H / I, or state L / I) means that the standard state for the specified operation / state of the tractor 1 is the steady stability mode. In this case, the ECU 17 adjusts the engine speed based on the second speed control map that is a speed control map for realizing high steady stability (step S112). As a result, the engine speed is controlled with a relatively low control gain, and as shown in the “steady stability mode” in FIG.

  As described above, the tractor 1 of the present embodiment includes the engine 6 that is a drive source and the ECU 17 that controls the engine 6, and can connect any of a plurality of work machines. The ECU 17 includes a first injection control map M1 indicating a fuel injection state in which priority is given to suppressing fuel consumption in relation to an engine speed and an output torque, and a fuel injection state in which priority is given to suppressing noise to the engine speed and the A second injection control map M2 shown in relation to the output torque is stored in advance. Then, the ECU 17 determines the work / state of the tractor 1 (in other words, the type and state of the work implement connected to the tractor 1) based on the information acquired from the engine 6 and the information acquired from the vehicle body 2 of the tractor 1. Identify. Further, the ECU 17 automatically selects either the first injection control map M1 or the second injection control map M2 in accordance with the work / state of the tractor 1, and the engine 6 based on the selected injection control map. To control.

  Thus, according to the work / state of the tractor 1, either the control giving priority to suppressing fuel consumption or the control giving priority to suppressing noise is automatically selected, and the injector 27 It is possible to perform control so that the fuel injection state from is appropriate for each situation.

  Further, the tractor 1 of the present embodiment includes a first speed control map showing a control gain of engine speed control giving priority to increasing responsiveness to fluctuations in engine speed in relation to the output torque, and a constant speed control map. A second speed control map that indicates the control gain of engine speed control giving priority to maintaining high stability of the engine speed at all times in relation to the output torque is stored in advance. Then, the ECU 17 automatically selects either the first speed control map or the second speed control map according to the work / state of the tractor 1 and rotates the engine based on the selected speed control map. The engine 6 is controlled so that the number is regulated.

  As a result, depending on the type or state of the work implement, priority was given to control that prioritizes maintaining high stability of the engine speed during steady operation, or priority was given to increasing responsiveness to fluctuations in engine speed. It is possible to automatically select one of the control and perform control so that the control gain of the engine speed control becomes appropriate according to each situation.

  Further, the tractor 1 of the present embodiment includes a mode switching operation tool 16 that allows the operator to select either the first injection control map M1 or the second injection control map M2.

  In other words, the tractor 1 of the present embodiment has a manual mode in which the engine 6 is controlled according to either the first injection control map M1 or the second injection control map M2 designated by the operator, and a first mode automatically selected by the ECU 17. And an automatic mode for controlling the engine 6 according to either the first injection control map M1 or the second injection control map M2.

  Accordingly, the operator can manually switch between performing control giving priority to suppressing fuel consumption and performing control giving priority to suppressing noise, and can respond flexibly to changes in the work environment of the tractor 1. Can respond.

  Furthermore, the tractor 1 of this embodiment includes an EGR device 20 that recirculates the exhaust gas corresponding to the EGR rate to the intake side. Then, different EGR rates are set when the engine 6 is controlled based on the first injection control map M1 and when the engine 6 is controlled based on the second injection control map M2.

  Accordingly, the EGR rate can be varied depending on whether priority is given to suppressing fuel consumption or priority on suppressing noise, and the engine 6 can be controlled more appropriately according to individual situations.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  In the above-described embodiment, the ECU 17 specifies the work of the tractor 1 (the type of connected working machine) and the state of the tractor 1. However, it can be changed so that only the operation of the tractor 1 is specified or only the state of the tractor 1 is specified.

  In the above-described embodiment, a rotary, a harrow, or the like is shown as a work machine that can be connected to the tractor 1. Even in that case, after considering which of the low fuel consumption and low noise is prioritized in the work machine (work), which mode is assigned as the standard setting between the low fuel consumption mode and the low noise mode. It can be configured that the control is performed in advance and the control is automatically performed accordingly.

  In the tractor 1 of the above embodiment, the ECU 17 acquires the engine speed detected by the engine speed sensor 34 as information from the engine. However, instead of this, or in addition to this, the ECU 17 acquires the output torque of the engine 6 detected by the torque detection sensor 35, and uses the information of the output torque to specify the work / state of the tractor 1. Also good.

  In the above-described embodiment, the fuel injection control and the speed control are performed by the control map. However, for at least one of the injection control information and the speed control information, for example, a function may be used instead of the control map.

  The present invention is not limited to the tractor 1 as an agricultural machine as in the above embodiment, but can be applied to, for example, a tractor as a construction machine.

1 Tractor 2 Car body 6 Engine 17 ECU
20 EGR device M1 first injection control map (first injection control information)
M2 second injection control map (second injection control information)

Claims (4)

The engine that is the drive source,
An engine control unit for controlling the engine;
With
In a tractor that can connect any of a plurality of work machines,
The engine control unit
First injection control information indicating a fuel injection state giving priority to suppressing fuel consumption in a relationship between an engine speed and an output torque;
Second injection control information indicating a fuel injection state giving priority to suppressing noise in relation to the engine speed and the output torque;
Is stored in advance,
Based on the information acquired from the engine and the information acquired from the body of the tractor, identify at least one of the type or state of the connected work implement,
According to the type or state of the work implement, either the first injection control information or the second injection control information is automatically selected, and the engine is controlled based on the selected injection control information. Tractor characterized by. The tractor according to claim 1,
The engine control unit
First speed control information indicating a control gain of engine speed control giving priority to increasing responsiveness to fluctuations in engine speed in relation to the output torque;
Second speed control information indicating a control gain of engine speed control giving priority to maintaining high stability of engine speed at a constant time in relation to the output torque;
Is stored in advance,
Depending on the type or state of the work implement, either the first speed control information or the second speed control information is automatically selected, and the engine speed is based on the selected speed control information. The tractor, wherein the engine is controlled so that the speed is controlled.   3. The tractor according to claim 1, further comprising an operating tool that allows an operator to select either the first injection control information or the second injection control information. 4. A tractor according to any one of claims 1 to 3,
The engine includes an EGR device that recirculates the exhaust gas corresponding to the EGR rate to the intake side,
A tractor, wherein the EGR rate is set to be different between when the engine is controlled based on the first injection control information and when the engine is controlled based on the second injection control information.

Images