JP2012062836A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device in which versatility of an ECU 11 is improved for a 1 type engine 70.SOLUTION: This engine control device includes the engine 70, a fuel injection device 117 for injecting fuel into the engine 70, detection means 12-19 for detecting a driving state of the engine 70, and the ECU 11 for controlling operation of the fuel injection device 117 based on detection information of the detection means 12-19 and proper output characteristic data M of the engine 70, and includes a data storage means 21 for storing correction characteristic data RL for correcting the output characteristic data M. The ECU 11 corrects the output characteristic data M based on the correction characteristic data RL while receiving the correction characteristic data RL from the data storage means 21, and operates the fuel injection device 117 based on the corrected output characteristic data M and the detection information of the detection means 12-19.

Description

  The present invention relates to an engine control device mounted on a work vehicle such as a tractor.

  In recent engines, a common rail fuel injection device is used to supply high pressure fuel to the injector for each cylinder, and the injection pressure, injection timing, and injection period (injection amount) of the fuel from each injector are electronically controlled. Thus, there is known a technique for reducing nitrogen oxide (NOx) discharged from the engine and reducing noise and vibration of the engine (see Patent Document 1).

Japanese Patent Laid-Open No. 10-9033

  By the way, in a work vehicle such as a tractor equipped with this type of engine and using a torque rise portion of the engine output characteristics, the ECU uses a common rail type based on output characteristics data such as a map format or a function table format, rotation speed and torque, for example. By controlling the operation of the fuel injection device, the engine output is adjusted by the fuel injection amount corresponding to the operation amount of the shift lever or the like. The output characteristic data corresponds to the vehicle on which the engine is mounted, and usually, only one type or a limited type is stored in the ECU. Therefore, the conventional configuration has a problem that even if the engine type is the same, for example, the ECU of the tractor engine is difficult to apply as the ECU of the backhoe engine (that is, the versatility of the ECU is low). It was. Further, even in the same work vehicle, it is assumed that different torque rise characteristics are preferred depending on the type of work. Such a problem exists not only in the common rail fuel injection device but also in the electronic governor type.

  In view of this, the present invention has a technical object to provide an engine control apparatus that solves the above-described problems.

  According to a first aspect of the present invention, there is provided an engine mounted on a work vehicle, a fuel injection device that injects fuel into the engine, a detection unit that detects a driving state of the engine, detection information of the detection unit, and the engine uniqueness And an ECU for controlling the operation of the fuel injection device based on the output characteristic data of the engine, and has data storage means for storing correction characteristic data for correcting the output characteristic data The ECU corrects the output characteristic data based on the correction characteristic data while receiving the correction characteristic data from the data storage means, and corrects the output characteristic data and the detection information of the detection means. Based on the above, the fuel injection device is operated.

  According to a second aspect of the present invention, in the engine control apparatus according to the first aspect, when the ECU has not received the correction characteristic data from the data storage means, the output characteristic data and detection information of the detection means Based on the above, the fuel injection device is operated.

  According to a third aspect of the present invention, in the engine control apparatus according to the first or second aspect, the data storage means includes a fuel injection for a predetermined rotational speed as the corrected characteristic data as compared with a maximum characteristic line of the output characteristic data. A plurality of limit injection amount values with reduced amounts are stored, and the ECU determines the maximum of the output characteristic data in a direction in which the fuel injection amount for an arbitrary rotational speed decreases based on the plurality of limit injection amount values. The characteristic line is corrected.

  According to a fourth aspect of the present invention, in the engine control apparatus according to the third aspect, the plurality of limited injection amount values include an injection amount value with respect to a low-speed rotational speed, an injection amount value with respect to the rotational speed when the maximum torque is generated, and a rating. The three points of the injection amount value with respect to the rotational speed are set as one set.

  According to invention of Claim 1, the engine mounted in a work vehicle, the fuel-injection apparatus which injects a fuel into the engine, the detection means which detects the drive state of the engine, the detection information of the detection means, and the engine An engine control device comprising an ECU for controlling the operation of the fuel injection device based on unique output characteristic data, comprising data storage means for storing correction characteristic data for correcting the output characteristic data. The ECU corrects the output characteristic data based on the correction characteristic data while receiving the correction characteristic data from the data storage means, and detects the corrected output characteristic data and the detection means. Since the fuel injection device is operated based on the information, the engine manufacturer stores in the ECU if the engine model is the same. The possible output characteristics data in common that. By using the modified characteristic data, the engine purchase manufacturer can execute optimal fuel injection control for the company's specifications without replacing the output characteristic data with the company's specifications. Therefore, there is an effect that both the advantage of the engine manufacturer that improves the versatility of the ECU and the advantage of the engine purchase manufacturer that the compatibility of the ECU with the work vehicle is ensured.

  According to a second aspect of the invention, in the engine control apparatus according to the first aspect, the ECU detects the output characteristic data and the detection means when the correction characteristic data is not received from the data storage means. Since the fuel injection device is operated based on the information, efficient fuel injection control can be easily executed, for example, depending on whether or not the work machine is installed or the use status of the work vehicle, without performing detailed setting operations. There is an effect that can be done.

  According to a third aspect of the present invention, in the engine control device according to the first or second aspect, the data storage means includes a fuel corresponding to a predetermined rotational speed as the corrected characteristic data as compared with a maximum characteristic line of the output characteristic data. A plurality of limit injection amount values in which the injection amount is decreased are stored, and the ECU is configured to reduce the fuel injection amount for an arbitrary rotation speed based on the plurality of limit injection amount values. Since the maximum characteristic line is corrected, it becomes possible to maintain the droop characteristic of the output characteristic data after correction in a state close to the droop characteristic of the output characteristic data before correction. Therefore, the fuel injection control can be executed in a state close to the design philosophy of the engine manufacturer and in conformity with the specifications of the engine purchase manufacturer. In addition, variations of the droop characteristic based on the limited injection amount value can be easily set, and there is an advantage that it is easy to cope with various fuel injection control settings.

  According to a fourth aspect of the present invention, in the engine control apparatus according to the third aspect, the plurality of limited injection amount values include an injection amount value for a low speed rotation speed, an injection amount value for a rotation speed when maximum torque is generated, and Since the three points of the injection amount value with respect to the rated rotational speed are set as one set, the downward correction of the maximum characteristic line can be efficiently performed with a small number of points.

It is a conceptual explanatory drawing which summarized embodiment of this invention. It is fuel system explanatory drawing of an engine. It is explanatory drawing of an output characteristic map. It is explanatory drawing of the output characteristic map after correction. It is a flowchart of fuel injection control. It is an external appearance perspective view of a diesel engine. It is a side view of a tractor.

  Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings when applied to an engine mounted on a tractor as a work vehicle.

(1). First, the fuel system structure of the common rail device 117 (common rail fuel injection device) and the engine 70 will be described with reference to FIG. The engine 70 is a four-cylinder type diesel engine. As shown in FIG. 2, a fuel tank 118 is connected to injectors 115 for four cylinders provided in the engine 70 via a common rail device 117 and a fuel supply pump 116. Each injector 115 is provided with an electromagnetic switching control type fuel injection valve 119. The common rail device 117 includes a cylindrical common rail 120.

  As shown in FIG. 2, a fuel tank 118 is connected to the suction side of the fuel supply pump 116 via a fuel filter 121 and a low pressure pipe 122. The fuel in the fuel tank 118 is sucked into the fuel supply pump 116 via the fuel filter 121 and the low pressure pipe 122. The fuel supply pump 116 of the embodiment is disposed in the vicinity of the intake manifold 73 (see FIG. *). Specifically, the cylinder block 75 is provided on the right side surface (the intake manifold 73 installation side) and below the intake manifold 73. On the other hand, the common rail 120 is connected to the discharge side of the fuel supply pump 116 via a high-pressure pipe 123. In addition, injectors 115 for four cylinders are connected to the common rail 120 via four fuel injection pipes 126, respectively.

  With the above configuration, the fuel in the fuel tank 118 is pumped to the common rail 120 by the fuel supply pump 116, and high-pressure fuel is stored in the common rail 120. Each fuel injection valve 119 is controlled to open and close, whereby high-pressure fuel in the common rail 120 is injected from each injector 115 to each cylinder of the engine 70. That is, by electronically controlling each fuel injection valve 119, the injection pressure, injection timing, and injection period (injection amount) of the fuel supplied from each injector 115 are controlled with high accuracy. Therefore, nitrogen oxide (NOx) from the engine 70 can be reduced, and noise and vibration of the engine 70 can be reduced.

  As shown in FIG. 2, a fuel supply pump 116 is connected to the fuel tank 118 via a fuel return pipe 129. A common rail return pipe 131 is connected to the end of the cylindrical common rail 120 in the longitudinal direction via a return pipe connector 130 that limits the pressure of fuel in the common rail 120. That is, surplus fuel from the fuel supply pump 116 and surplus fuel from the common rail 120 are collected in the fuel tank 118 via the fuel return pipe 129 and the common rail return pipe 131.

(2). Fuel Injection Control of Common Rail Device Next, fuel injection control of the common rail device 117 will be described with reference to FIGS. As shown in FIG. 2, an ECU 11 is provided for operating a fuel injection valve 119 for each cylinder in the engine 70. Although not shown in detail, the ECU 11 is a CPU that executes various arithmetic processes and controls, an EEPROM that stores control programs and data, a flash memory, a RAM that temporarily stores control programs and data, a CAN controller, and an input / output An interface or the like is provided, and the engine 70 or the vicinity thereof is disposed.

  On the input side of the ECU 11, at least the rail pressure sensor 12 that detects the fuel pressure in the common rail 120, the electromagnetic clutch 13 that rotates or stops the fuel pump 116, and the rotational speed of the engine 70 (the camshaft position of the crankshaft 74). An engine speed sensor 14 for detecting fuel, an injection setting device 15 for detecting and setting the number of fuel injections of each injector 115 (the number of fuel injections during the fuel injection period of one stroke), and an accelerator operating tool such as a throttle lever or an accelerator pedal ( (Not shown) a throttle position sensor 16 for detecting the operation position, a turbo booster sensor 17 for detecting the pressure of the turbocharger 100, an intake air temperature sensor 18 for detecting the intake air temperature of the intake manifold 73, and cooling of the engine 70 A cooling water temperature sensor 19 for detecting the water temperature is connected. These sensors 12 to 19 constitute detection means for detecting the driving state of the engine 70.

  At the output side of the ECU 11, electromagnetic solenoids of the fuel injection valves 119 for at least four cylinders are respectively connected. That is, the high-pressure fuel stored in the common rail 120 is injected from the fuel injection valve 119 in a plurality of times during one stroke while controlling the fuel injection pressure, the injection timing, the injection period, and the like, so that nitrogen oxide (NOx ), And complete combustion with reduced generation of soot and carbon dioxide is performed to improve fuel efficiency.

  The storage means (flash memory or EEPROM) provided in the ECU 11 has an output characteristic map as output characteristic data indicating the relationship between the rotational speed N of the engine 70 and the torque T (may be referred to as fuel injection amount or load). M (see FIG. 3) is stored in advance. This kind of output characteristic map M is obtained by experiments or the like. The output characteristic data is not limited to the map format as in the embodiment, and may be a function table, set data (data table), or the like. In the output characteristic map M shown in FIG. 3, the rotational speed N is taken on the horizontal axis and the torque T (fuel injection amount) is taken on the vertical axis. In the output characteristic map M, a solid line Tmx drawn in an upwardly convex curve is a maximum characteristic line (which may be referred to as a maximum torque line) representing the maximum torque for each rotational speed N. In this case, if the model of the engine 70 is the same, the output characteristic maps M stored in the ECU 11 are all the same (common).

  The ECU 11 basically obtains the torque T from the rotational speed N detected by the engine speed sensor 14 and the injection pressure / injection period of each injector 115 and uses the torque T and the output characteristic map M to target fuel injection amount. The fuel injection control is performed such that Ro is calculated and the common rail device 117 is operated based on the calculation result. Here, the fuel injection amount is adjusted by adjusting the valve opening period of each fuel injection valve 119 and changing the injection period to each injector 115.

  A work machine ECU 21 as data storage means is electrically connected to the ECU 11 via a CAN communication bus 23 (see FIG. 2). The work machine ECU 21 has a function of controlling the drive of a work machine (cultivator, plow, bucket, etc.) mounted on the work vehicle. Like the ECU 11, the work machine ECU 21 includes a CPU, an EEPROM, a flash memory, a RAM, a CAN controller, an input / output interface, and the like, and can be disposed at any location of the work machine. Of course, it is possible to arrange the engine 11 or the main body of the work vehicle together with the ECU 11.

  The CAN communication bus 23 is a communication line for data communication using a CAN (controller area network) protocol. As is clear from this point, the CAN communication environment is applied to the ECU 11 and the work machine ECU 21. Data communication based on the CAN communication protocol is an extension of the LAN communication environment. The CAN communication protocol is a differential two-wire having a common return (an instruction to return a program that has moved to a subroutine or interrupt routine to the main routine). A serial communication protocol that uses a bus line to maintain distributed real-time control and multiplexing.

  In the storage means (flash memory or EEPROM) of the work machine ECU 21, the fuel injection amount with respect to the predetermined rotational speed N as correction characteristic data for correcting the operation of the common rail device 117 as compared with the maximum characteristic line Tmx of the output characteristic map M. A plurality of limit injection amount values RL for decreasing the value are stored. As shown in FIGS. 1, 2 and 4, the limited injection amount value RL corresponds to the first injection amount value RL1 for the low speed rotation speed N1 such as the low idle rotation speed, and the rotation speed N2 when the maximum torque is generated. The three points of the second injection amount value RL2 and the injection amount value RL3 for the rated rotational speed N3 are stored as one set in the storage unit of the work machine ECU 21. The first injection amount value RL1 of the embodiment is set to a value approximately equal to the injection amount value for the low speed rotation speed N1 in the original output characteristic map M. The second injection amount value RL2 is set to a value of about 80% of the injection amount value with respect to the rotational speed N2 when the maximum torque is generated in the original output characteristic map M. The third injection amount value RL3 is also set to a value of about 80% of the injection amount value with respect to the rated rotational speed N3 in the original output characteristic map M.

  The ECU 11 to which the work implement ECU 21 is connected is configured to correct the maximum characteristic line Tmx of the output characteristic map M in a direction in which the fuel injection amount for an arbitrary rotation speed N decreases based on the limit injection amount value RL. (Refer to the maximum characteristic line Tmx ′ after correction, FIG. 4). In this case, the corrected maximum characteristic line Tmx ′ is a line formed by connecting the first to third injection amount values RL1 to RL3. Then, the ECU 11 calculates the torque T based on the rotational speed N, the injection pressure / injection period of each injector 115, and the corrected output characteristic map M (maximum characteristic line Tmx ′) to obtain the target fuel injection amount Ro. The common rail device 117 is operated so as to limit the fuel injection amount for the predetermined rotational speed N based on the calculation result.

  The corrected maximum characteristic line Tmx ′ (indicated by a solid line in FIG. 4) limits the fuel injection amount for the predetermined rotational speed N as compared with the maximum characteristic line Tmx before correction (indicated by a broken line in FIG. 4). The droop characteristic is exhibited. That is, the maximum torque at the same rotational speed N is smaller when it is obtained from the output characteristic map M after correction than when it is obtained from the output characteristic map M before correction (the maximum characteristic line Tmx before correction). The maximum characteristic line Tmx ′ after correction is located on the inner side (lower side).

  Various settings can be adopted as the setting of the limit injection amount value RL. For example, in order to suppress the engine stall for work with large load fluctuations, the limit injection amount value RL becomes a maximum characteristic line Tmx ′ for obtaining high torque over a wide rotational speed range, or for work with small load fluctuations. In order to increase the work efficiency, the limit injection amount value RL becomes a maximum characteristic line Tmx ′ that reduces the rotation fluctuation due to the load fluctuation, or the rotation before the connection in order to reduce the shock of the connection for the clutch connection work. The limit injection amount value RL can be set to a maximum characteristic line Tmx ′ for decreasing the speed.

  In the embodiment, while the limited injection amount value RL is received from the work machine ECU 21, the ECU 11 corrects the output characteristic map M and operates the common rail device 117 using the corrected output characteristic map M. If not received, the common rail device 117 is operated using the original output characteristic map M. For example, when the working machine is not attached to the work vehicle, the work machine ECU 21 is not connected to the ECU 11, or the work machine ECU 21 does not store the limited injection quantity value RL. In addition, there are cases where communication is impossible.

  As shown in FIGS. 1 and 2, the engine control apparatus of the embodiment is shipped from an engine manufacturer with an output characteristic map M written in the ECU 11. When the engine purchase manufacturer mounts the engine 70 on the work vehicle, the work machine ECU 21 storing the limited injection amount value RL is connected to the ECU 11 via the CAN communication bus 23.

  The limited injection amount value RL as the correction characteristic data may be stored in a plurality of sets corresponding to each vehicle type on which the engine 70 is mounted or each work machine (cultivator, plow, bucket, etc.) mounted on the work vehicle. Is possible. In this case, the selection of the limited injection amount value RL for each group may be performed by, for example, a jumper pin provided in the ECU 11 or a selection switch provided in the cabin of the work vehicle. Moreover, the structure which selects the limited injection amount value RL of each group with the control signal from the work machine ECU21 is also possible.

  Although not described in detail, the embodiment is configured to select the limited injection amount value RL corresponding to the work machine by mounting the work machine on the work vehicle. For example, when a discrimination button for each work implement is arranged on the vehicle side hitch provided at the rear of the work vehicle and the work implement side hitch is connected to the vehicle side hitch, the discrimination button corresponding to the work implement is set by connection. What is necessary is just to comprise. Here, assuming that one set of limited injection amount values RL is for a tiller and another set of limited injection amount values RL is for a plow, if a tiller is mounted on the work vehicle, The machine discrimination button is set, and in order to correct the output characteristic map M, the ECU 11 refers to a set of limited injection amount values RL for the tiller. When the plow is attached, the plow discrimination button is set, and the ECU 11 refers to another set of limited injection amount values RL for plow.

  Hereinafter, an example of the fuel injection control in the embodiment will be described with reference to the flowchart of FIG. As shown in the flowchart of FIG. 5, the ECU 11 determines whether or not the limit injection amount value RL is being received from the work machine ECU 21 (S1). If the limited injection amount value RL has not been received (S1: NO), the rotational speed N and the injection pressure / injection period of each injector 115 are read at a predetermined timing (appropriately every time) (S2), and then the ECU 11 Referring to the output characteristic map M possessed by itself, the target fuel injection amount Ro is calculated by obtaining the torque T from the rotational speed N read earlier and the injection pressure / injection period of each injector 115 (S3). Then, the common rail device 117 is operated based on the target fuel injection amount R (S4). Thereafter, if the key switch for power supply (not shown) is turned on (S5: YES), the process returns to step S1 to continue the fuel injection control.

  If the limited injection amount value RL is received in step S1 (S1: YES), the rotational speed N and the injection pressure / injection period of each injector 115 are read at a predetermined timing (appropriately every time) (S6), Next, the ECU 11 corrects the maximum characteristic line Tmx of the output characteristic map M in the direction in which the fuel injection amount for an arbitrary rotational speed N decreases based on the limited injection amount value RL, and sets the maximum characteristic line to Tmx ′ (S7). ). Then, the torque T is obtained from the rotational speed N read earlier and the injection pressure / injection period of each injector 115, and the target fuel injection subjected to torque limitation is referred to with reference to the corrected output characteristic map M (maximum characteristic line Tmx ′). The amount Ro is calculated (S8). Then, the common rail device 117 is operated based on the target fuel injection amount Ro whose torque is limited (S9). Thereafter, if the key switch for power supply (not shown) is in the on state (S10: YES), the process returns to step S1 to continue the fuel injection control.

  As is clear from the above description and FIGS. 1 to 5, the engine 70 mounted on the work vehicle, the fuel injection device 117 that injects fuel into the engine 70, and the detection means that detects the driving state of the engine 70. 12 to 19 and an ECU 11 that controls the operation of the fuel injection device 117 based on detection information of the detection means 12 to 19 and output characteristic data M unique to the engine 70, The ECU 11 includes data storage means 21 in which correction characteristic data RL for correcting the output characteristic data M is stored, and the ECU 11 receives the correction characteristic data RL from the data storage means 21 while the correction characteristic data RL is being received. Based on the corrected characteristic data RL, the output characteristic data M is corrected, the corrected output characteristic data M, the detection information of the detection means 12 to 19, and Since actuating the fuel injection device 117 on the basis of the engine manufacturer, the long type of engine 70 are the same, can the output characteristic data M to be stored in the ECU11 in common. By using the modified characteristic data RL, the engine purchase manufacturer can execute the optimum fuel injection control for the company specifications without replacing the output characteristic data M with the company-specific characteristic data. There is an effect that it is possible to achieve both the advantage of the engine manufacturer that improves the versatility of the ECU 11 and the advantage of the engine purchase manufacturer that ensures the suitability of the ECU 11 for the work vehicle.

  As is clear from the above description and FIGS. 1 to 5, the ECU 11 receives the output characteristic data M and the detection means 12 to 19 when the correction characteristic data RL is not received from the data storage means 21. The fuel injection device 117 is operated based on the detected information, so that it is possible to perform efficient fuel injection control, for example, depending on whether or not the work machine is installed or the use state of the work vehicle, without performing detailed setting operations. There is an effect that it can be easily executed.

  As is apparent from the above description and FIGS. 1 to 5, the data storage means 21 stores the fuel injection amount with respect to a predetermined rotational speed N as the corrected characteristic data as compared with the maximum characteristic line Tmx of the output characteristic data M. The ECU 11 stores the output characteristic data M in a direction in which the fuel injection amount with respect to an arbitrary rotational speed N decreases based on the plurality of limit injection amount values RL. Since the maximum characteristic line Tmx is corrected, the droop characteristic (Tmx ′) of the corrected output characteristic data M can be maintained in a state close to the droop characteristic (Tmx) of the output characteristic data M before correction. Become. Therefore, the fuel injection control can be executed in a state close to the design philosophy of the engine manufacturer and in conformity with the specifications of the engine purchase manufacturer. Further, there is an advantage that variations of the droop characteristic based on the limited injection amount value RL can be easily set, and it is easy to cope with various fuel injection control settings.

  As apparent from the above description and FIGS. 1 to 5, the plurality of limited injection amount values RL include the injection amount value RL1 for the low speed rotation speed N1, the injection amount value RL2 for the rotation speed N2 when the maximum torque is generated, and Since the three points of the injection amount value RL3 with respect to the rated rotational speed N3 are set as one set, downward correction (Tmx → Tmx ′) of the maximum characteristic line can be efficiently performed with a small number of points.

(3). Next, the overall structure of the engine 70 will be described with reference to FIG. The engine 70 according to the embodiment is of a four-cylinder type, and an exhaust manifold (not shown) is disposed on the left side surface of the cylinder head 72 in the engine 70. An intake manifold 73 is disposed on the right side surface of the cylinder head 72. The cylinder head 72 is mounted on a cylinder block 75 in which a crankshaft and a piston (not shown) are built. The front and rear front ends of the crankshaft protrude from the front and rear side surfaces of the cylinder block 75, respectively. A cooling fan 76 is provided on the front side of the cylinder block 75. The rotational force is transmitted from the front end side of the crankshaft to the cooling fan 76 via the V belt 77.

  A flywheel housing 78 is fixed to the rear surface of the cylinder block 75. A flywheel (not shown) is disposed in the flywheel housing 78. The flywheel is pivotally supported on the rear end side of the crankshaft, and is configured to rotate integrally with the crankshaft. It is comprised so that the motive power of the engine 70 may be taken out to the drive part of a work vehicle via a flywheel. An oil pan 81 is disposed on the lower surface of the cylinder block 75. Engine leg mounting portions 82 are respectively provided on the left and right side surfaces of the cylinder block 75 and the left and right side surfaces of the flywheel housing 78. An engine leg (not shown) having a vibration proof rubber is bolted to each engine leg mounting portion 82. The engine 70 is supported in an anti-vibration manner on the engine support chassis 84 of the tractor 201 via each engine leg.

  An air cleaner (not shown) is connected to the inlet side of the intake manifold 73 via a collector 92 constituting an EGR device 91 (exhaust gas recirculation device). The outside air removed and purified by the air cleaner is sent to the intake manifold 73 via the collector 92 of the EGR device 91 and supplied to each cylinder of the engine 70. The EGR device 91 is a collector (EGR main body case) 92 that mixes recirculated exhaust gas of the engine 70 (EGR gas from the exhaust manifold 71) and fresh air (external air from the air cleaner) and supplies them to the intake manifold 73. The recirculation exhaust gas pipe 95 connected to the exhaust manifold 71 via the EGR cooler 94 and the EGR valve 96 communicating the collector 92 with the recirculation exhaust gas pipe 95 are provided.

  With the above configuration, external air is supplied from the air cleaner into the collector 92, while EGR gas (a part of the exhaust gas discharged from the exhaust manifold 71) is supplied from the exhaust manifold 71 into the collector 92 through the EGR valve 96. To do. After the external air from the air cleaner and the EGR gas from the exhaust manifold 71 are mixed in the collector 92, the mixed gas in the collector 92 is supplied to the intake manifold 73. That is, a part of the exhaust gas discharged from the engine 70 to the exhaust manifold 71 is recirculated from the intake manifold 73 to the engine 70, so that the maximum combustion temperature during high-load operation is lowered, and NOx (nitrogen) from the engine 70 is reduced. Oxide emissions are reduced.

  A turbocharger 100 is attached to the left side surface of the cylinder head 72. The turbocharger 100 includes a turbine case 101 with a turbine wheel (not shown) and a compressor case 102 with a blower wheel (not shown). An exhaust manifold is connected to the exhaust gas intake pipe 105 of the turbine case 101. Although illustration is omitted, a tail pipe is connected to the exhaust gas discharge pipe 103 of the turbine case 101 via a muffler or a diesel particulate filter. That is, the exhaust gas discharged from each cylinder of the engine 70 to the exhaust manifold 71 is discharged to the outside through the turbocharger 100 and the like from the tail pipe.

  On the other hand, the air intake side of the air cleaner is connected to the air intake side of the compressor case 102 via the air supply pipe 104. An intake manifold 73 is connected to the supply / discharge side of the compressor case 102 via a supercharging pipe 108. That is, the outside air removed by the air cleaner is supplied from the compressor case 102 to each cylinder of the engine 70 through the supercharging pipe 108.

  A fuel tank 118 (see FIG. 2) is connected to each of the injectors 115 for four cylinders provided in the engine 70 via a common rail device 117 and a fuel supply pump 116. Each injector 115 is provided with an electromagnetic switching control type fuel injection valve 119. The common rail device 117 includes a cylindrical common rail 120. A fuel tank 118 (see FIG. 2) is connected to the suction side of the fuel supply pump 116 via a fuel filter 121 and a low pressure pipe 122. A common rail 120 is connected to the discharge side of the fuel supply pump 116 via a high-pressure pipe 123.

(5). Outline of Tractor Next, an outline of a tractor 201 as a work vehicle on which the engine 70 is mounted will be described with reference to FIG. The tractor 201 supports the traveling machine body 202 with a pair of left and right rear wheels 204 as well as a pair of left and right front wheels 203, and drives the rear wheels 204 and the front wheels 203 with the engine 70 mounted on the front part of the traveling machine body 202. By doing so, it is configured to travel forward and backward.

  The engine 70 mounted on the front portion of the traveling machine body 202 is covered with a bonnet 206. A cabin 207 is installed on the upper surface of the traveling machine body 202. Inside the cabin 207, a steering seat 208 on which an operator sits, and a steering handle 209 having a round handle shape as steering means positioned in front of the steering seat 208 are provided. Is provided. When the operator seated on the control seat 208 rotates the control handle 209, the steering angle (steering angle) of the left and right front wheels 203 changes according to the amount of operation. At the bottom of the cabin 207, a step 210 for an operator to board is provided. The ECU 11 is disposed in the front column of the cabin 207.

  The traveling machine body 202 includes an engine frame 214 having a front bumper 212 and a front axle case 213, and left and right machine body frames 216 that are detachably connected to the rear portion of the engine frame 214 by fastening bolts. The front wheel 203 is attached via a front axle case 213 mounted so as to protrude outward from the outer surface of the engine frame 214. In addition, a transmission case 217 is connected to the rear part of the body frame 216 for appropriately shifting the output from the engine 70 and transmitting it to the rear wheel 204 (front wheel 203). The rear wheel 204 is attached to the mission case 217 via a rear axle case (not shown) mounted so as to protrude outward from the outer surface of the mission case 217.

  On the rear upper surface of the transmission case 217, a hydraulic working machine lifting mechanism 220 for lifting and lowering a working machine (not shown) such as a tiller or a plow is detachably attached. The work machine is connected to the rear part of the mission case 217 via a lower link (not shown) and a top link 222 so as to be movable up and down. Further, a PTO shaft 223 for driving the work machine is provided on the rear side surface of the mission case 217.

  Although illustration is omitted, the rotational power of the engine 70 is transmitted from the rear surface side of the engine 70 to the front surface side of the transmission case 217 via a crankshaft and a flywheel. The rotational power of the engine 70 is transmitted to the transmission case 217, and then the rotational power of the engine 70 is appropriately changed by the hydraulic continuously variable transmission or the traveling auxiliary transmission gear mechanism of the transmission case 217, via a differential gear mechanism or the like. Thus, the driving force is transmitted from the mission case 217 to the rear wheel 204. Further, the rotation of the engine 70 that is appropriately shifted by the traveling auxiliary transmission gear mechanism is configured to be transmitted from the transmission case 217 to the front wheel 203 via the differential gear mechanism of the front axle case 213 or the like.

(6). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, the present invention is not limited to an engine control device for an engine mounted on a tractor, but can also be applied as an engine control device for an engine mounted on a farm work machine such as a combine or rice transplanter or a special work vehicle such as a wheel loader. . The fuel injection device is not limited to a common rail type, but may be an electronic governor type. The communication bus is not limited to the CAN communication bus, but may be another communication bus such as a LAN communication bus. The data storage means may be external storage means such as a flash memory or a hard disk as long as it is separate from the ECU 11. In addition, the configuration of each unit is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

M Output characteristics map (Output characteristics data)
RL Limit injection amount value (correction characteristic data)
Tmx Maximum characteristic line before correction Tmx 'Maximum characteristic line after correction N Rotational speed T Torque 11 ECU
12 Rail pressure sensor 13 Electromagnetic clutch 14 Engine speed sensor 15 Injection setter 16 Throttle position sensor 17 Turbo pressure increase sensor 18 Intake air temperature sensor 19 Cooling water temperature sensor 21 Work machine ECU (data storage means)
23 CAN communication bus 70 engine 115 injector 117 common rail device 120 common rail

Claims (4)

Based on an engine mounted on a work vehicle, a fuel injection device that injects fuel into the engine, a detection unit that detects a driving state of the engine, detection information of the detection unit, and output characteristic data unique to the engine An engine control device comprising an ECU for controlling the operation of the fuel injection device,
The ECU has data storage means for storing correction characteristic data for correcting the output characteristic data, and the ECU stores the correction characteristic data in the correction characteristic data while receiving the correction characteristic data from the data storage means. Correcting the output characteristic data based on the output characteristic data, and operating the fuel injection device based on the corrected output characteristic data and the detection information of the detection means,
Engine control device. The ECU operates the fuel injection device based on the output characteristic data and detection information of the detection means when the correction characteristic data is not received from the data storage means.
The engine control apparatus according to claim 1. The data storage means stores a plurality of limited injection amount values obtained by reducing the fuel injection amount for a predetermined rotational speed as the corrected characteristic data compared to the maximum characteristic line of the output characteristic data. Correcting the maximum characteristic line of the output characteristic data in a direction in which the fuel injection amount for an arbitrary rotation speed decreases based on the plurality of limit injection amount values;
The engine control apparatus according to claim 1 or 2. The plurality of limited injection amount values are a set of three points: an injection amount value with respect to a low speed rotation speed, an injection amount value with respect to the rotation speed when the maximum torque is generated, and an injection amount value with respect to the rated rotation speed.
The engine control apparatus according to claim 3.

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