Internal combustion engine control device

Abstract

In an internal combustion engine control device 100, a control unit 151 executes abnormality response control when one of either the angular acceleration ATCCP of the crankshaft of an internal combustion engine 1 in the compression stroke or a throttle opening TH detected by a throttle opening detection system including a throttle opening sensor 104 is outside a predetermined range for the one defined in correspondence with the other.

Description

Internal combustion engine control device

[0001] The present invention relates to an internal combustion engine control device.

[0002] In recent years, when an abnormality occurs in a throttle opening sensor that detects the throttle opening, which is the opening of the throttle valve of an internal combustion engine installed in a vehicle, etc., a configuration has been adopted in which abnormality response control is performed, such as closing the throttle valve and stopping the fuel injection operation and ignition operation of the internal combustion engine.

[0003] Under such circumstances, Patent Document 1 discloses a vehicle control device in which, if there is an abnormality in either the first or second throttle opening sensor, the ECU identifies which of the first and second throttle opening sensors has an abnormality based on the relationship between the difference between the target engine torque and the actual engine torque and a predetermined value, and performs feedback control using the first and second throttle opening sensor that is not abnormal to achieve the target throttle opening.

[0004] JP 2010-156215 A

[0005] However, according to the inventor's investigations, although the configuration of Patent Document 1 is intended to provide a vehicle control device that can appropriately control the vehicle even if an abnormality occurs in either the first or second throttle position sensor, it is still premised on the provision of the first and second throttle position sensors, and the configuration is complicated, and there is room for improvement in this respect.Furthermore, the same situation applies to a throttle position detection system that includes, in addition to the throttle position sensor, electrical wiring that electrically connects the throttle position sensor to an internal combustion engine control device that controls the operating state of the internal combustion engine, and an input circuit that is provided in the internal combustion engine control device and receives the electrical signal output from the throttle position sensor.

[0006] The present invention was made based on the above considerations, and aims to provide an internal combustion engine control device that can execute abnormality response control to respond to abnormalities in the throttle opening detection system with a simple configuration that does not use multiple throttle opening sensors.

[0007] In order to achieve the above object, one aspect of the present invention is an internal combustion engine control device that includes a control unit that executes abnormality response control in response to an abnormality in a throttle opening detection system that detects the throttle opening, which is the opening of the throttle valve of an internal combustion engine, wherein the control unit calculates the angular acceleration of the crankshaft during the compression stroke of the internal combustion engine, and executes the abnormality response control when either the calculated angular acceleration or the throttle opening detected by the throttle opening detection system is outside a predetermined range defined for the other.

[0008] According to one aspect of the internal combustion engine control device of the present invention, the control unit executes abnormality response control when either the angular acceleration of the crankshaft during the compression stroke of the internal combustion engine or the throttle opening detected by a throttle opening detection system including a throttle opening sensor is outside a predetermined range for that one defined corresponding to the other, so that abnormality response control that responds to an abnormality in the throttle opening detection system can be executed with a simple configuration that does not use multiple throttle opening sensors.

[0009] FIG. 1 is a schematic diagram showing the configuration of an internal combustion engine control device according to an embodiment of the present invention, together with an internal combustion engine to which the control device is applied. FIG. 2A is a flowchart showing an example of an abnormality response control process executed by the internal combustion engine control device according to this embodiment. FIG. 2B is a schematic diagram showing an example of table data used in the abnormality response control process executed by the internal combustion engine control device according to this embodiment. FIG. 3 is a flowchart showing an example of a compression stroke angular velocity calculation process in the abnormality response control process executed by the internal combustion engine control device according to this embodiment. FIG. 4A is a flowchart showing another example of the abnormality response control process executed by the internal combustion engine control device according to this embodiment. FIG. 4B is a schematic diagram showing another example of table data used in the abnormality response control process executed by the internal combustion engine control device according to this embodiment.

[0010] Hereinafter, an internal combustion engine control device according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[0011] <Configuration of Internal Combustion Engine> First, with reference to FIG. 1, the configuration of an internal combustion engine to which the internal combustion engine control device of this embodiment is applied will be described in detail.

[0012] FIG. 1 is a schematic diagram showing the configuration of an internal combustion engine control device according to this embodiment, together with an internal combustion engine to which the control device is applied.

[0013] As shown in FIG. 1 , the internal combustion engine 1 is typically a four-stroke reciprocating internal combustion engine mounted on a vehicle such as a motorcycle (not shown), and its operating state is controlled by an internal combustion engine control device 100. The internal combustion engine 1 includes a cylinder block 2. While the internal combustion engine 1 is shown in the figure as having only a single cylinder 2 a for ease of explanation, the internal combustion engine 1 may include multiple cylinders 2 a, and the cylinders 2 a may be arranged in an in-line, horizontally opposed, V-type, or other configuration. The internal combustion engine 1 is typically water-cooled, and a water temperature sensor 101 is provided in a cooling water passage 3 in the side wall of the cylinder block 2 to detect the temperature of the cooling water flowing through the cooling water passage 3. The water temperature sensor 101 outputs an electrical signal, exhibiting a voltage corresponding to the temperature of the cooling water flowing through the cooling water passage in the side wall of the cylinder block 2, to the internal combustion engine control device 100. If the internal combustion engine 1 is an air-cooled type, a temperature sensor (not shown) capable of detecting the temperature of the internal combustion engine 1 will be provided in the cylinder block 2 or the like instead of the water temperature sensor 101 .

[0014] A piston 4 is disposed inside the cylinder block 2. The piston 4 is connected to a crankshaft 6 via a connecting rod 5. A reluctor 7 is provided on the crankshaft 6 and rotates coaxially with the crankshaft 6. A plurality of teeth 7a are provided on the outer periphery of the reluctor 7, arranged in a predetermined pattern along the circumference. A crank angle sensor 102 is provided near the plurality of teeth 7a in a lower case (not shown) attached to the bottom of the cylinder block 2 and detects the rotational angle (rotational position) of the crankshaft 6 so that the internal combustion engine control device 100 can calculate the rotational speed of the internal combustion engine 1 and the position of the piston 4. The crank angle sensor 102 outputs an electrical signal to the internal combustion engine control device 100, exhibiting high and low voltages corresponding to the plurality of teeth 7a of the reluctor 7 that rotate with the rotation of the crankshaft 6 and the recesses between them.

[0015] A cylinder head 8 is attached to the top of the cylinder block 2. The inner wall surface of the cylinder block 2, the upper surface of the piston 4, and the inner wall surface of the cylinder head 8 cooperate to define an internal space which serves as a combustion chamber 9.

[0016] The cylinder block 2 and the cylinder head 8 are provided with a spark plug 10 for each cylinder 2a, which ignites an air-fuel mixture produced from fuel and air in the combustion chamber 9. The ignition operation of the spark plug 10 is controlled by the internal combustion engine control device 100, which controls the supply of electricity to an ignition coil (not shown).

[0017] The cylinder head 8 is provided with an intake valve 12 that freely opens and closes communication between the combustion chamber 9 and an intake passage 11a. The intake passage 11a is formed in the cylinder head 8 and an intake pipe 11 attached to the cylinder head 8. The intake pipe 11 is provided with a fuel injection valve 13 that injects fuel into the intake passage 11a and a throttle valve 14a that is located upstream of the fuel injection valve 13 and is a component of a throttle device 14. The intake pipe 11 is provided with an intake pressure sensor 103 between the intake valve 12 and the throttle valve 14a that detects the pressure (intake pressure) of air flowing into the intake pipe 11. The intake pressure sensor 103 outputs an electrical signal exhibiting a voltage corresponding to the intake pressure to the internal combustion engine control device 100. A throttle opening sensor 104 that detects the opening degree of the throttle valve 14a is attached to the main body of the throttle device 14, etc. The throttle opening sensor 104 outputs an electrical signal exhibiting a voltage corresponding to the opening of the throttle valve 14a (throttle opening) to the internal combustion engine control device 100. The fuel injection operation (valve opening operation) of the fuel injection valve 13 is controlled by the internal combustion engine control device 100 by controlling the supply of electricity to a solenoid valve (not shown). Here, the throttle opening detection system is a concept that includes not only the throttle opening sensor 104 but also an input circuit provided in the internal combustion engine control device 100 to receive the electrical signal output from the throttle opening sensor 104, and an electrical path such as electrical wiring between the throttle opening sensor 104 and the input circuit of the internal combustion engine control device 100. It should be noted that the fuel injection valve 13 may be a type that injects fuel directly into the combustion chamber 9.

[0018] An exhaust pipe 15 is attached to the cylinder head 8 on the opposite side of the intake pipe 11. An exhaust passage 15a communicating with the combustion chamber 9 is formed within the cylinder head 8 and the exhaust pipe 15. The cylinder head 8 is also provided with an exhaust valve 16 that freely opens and closes communication between the combustion chamber 9 and the exhaust passage 15a. A catalyst 17, typically a three-way catalyst, is provided in the exhaust pipe 15 downstream of the exhaust valve 16 to purify the exhaust gas discharged from the combustion chamber 9. An O2 sensor 105 is provided upstream of and adjacent to the catalyst 17 to detect the oxygen concentration in the exhaust gas. The O2 sensor 105 outputs an electrical signal, exhibiting a voltage corresponding to the oxygen concentration in the exhaust gas upstream of the catalyst 17, to the internal combustion engine control device 100. The O2 sensor may be provided not only upstream of the catalyst 17 but also downstream of the catalyst 17.

[0019] An accelerator opening sensor 106 is attached to a steering wheel or the like (not shown) of the vehicle, and detects the amount of operation (accelerator opening) of an accelerator grip or other accelerator operating member (not shown) of the vehicle. The accelerator opening sensor 106 outputs an electrical signal exhibiting a voltage corresponding to the accelerator opening to the internal combustion engine control device 100. In addition, a vehicle speed sensor 107 is attached to the front wheels (not shown) which are driven wheels of the vehicle, and the vehicle speed sensor 107 detects the rotation speed of the front wheels so that the internal combustion engine control device 100 calculates the vehicle speed. The vehicle speed sensor 107 outputs an electrical signal exhibiting a voltage corresponding to the rotation speed of the front wheels to the internal combustion engine control device 100. Note that the vehicle speed sensors may be attached not only to the front wheels but also to the rear wheels. Furthermore, the throttle device 14 is typically an electronically controlled type in which the throttle opening of the throttle valve 14a is controlled by the internal combustion engine control device 100 via a throttle motor, but it may also be a mechanical type in which the throttle opening changes directly and mechanically in response to the accelerator pedal position. If the throttle device 14 is a mechanical type, the throttle opening is determined only in accordance with the accelerator pedal position, whereas if the throttle device 14 is an electronically controlled type, the throttle opening is controlled based on the accelerator pedal position as well as other parameters.

[0020] <Configuration of Internal Combustion Engine Control Device> Next, with reference to FIG. 1, the configuration of the internal combustion engine control device 100 according to this embodiment will be described in detail.

[0021] First, as shown in FIG. 1, an internal combustion engine control device 100 is configured by an ECU (Electronic Control Unit), which is an electronic control device mounted on a vehicle and controls the operation of an internal combustion engine 1 .

[0022] Such an ECU is an arithmetic processing device consisting of a CPU (Central Processing Unit) 150, a memory (not shown), etc., in which the necessary control / processing programs and control / processing data are stored, and the CPU 150, the memory, etc. constitute a microcomputer.

[0023] Specifically, the CPU 150 includes a control unit 151. The control unit 151 controls the operation of the various control targets, such as the spark plug 10, the fuel injection valve 13, and the throttle valve 14a, based on values ​​acquired from electrical signals output from various sensors, namely, the water temperature sensor 101, the crank angle sensor 102, the intake pressure sensor 103, the throttle opening sensor 104, the O2 sensor 105, the accelerator opening sensor 106, and the vehicle speed sensor 107, and also reads out necessary control / processing programs and control / processing data from memory, and executes the control / processing programs to thereby control the operating state of the internal combustion engine 1. Note that in the drawing, the control unit 151 is shown as a functional block when the CPU 150 executes the control / processing programs.

[0024] In addition, the control unit 151 determines whether there is an abnormality in the throttle opening detection system, which includes the throttle opening sensor 104 and detects the throttle opening of the throttle valve 14a, and if it determines that there is an abnormality, executes abnormality response control that stops the ignition operation of the spark plug 10, stops the fuel injection operation of the fuel injection valve 13, and, if the throttle device 14 is electronically controlled, sets the throttle opening of the throttle valve 14a to a fully closed opening, in whole or in part.

[0025] More specifically, the control unit 151 calculates the angular acceleration of the crankshaft (the rotation axis of the crankshaft 6) during the compression stroke of the internal combustion engine 1 based on the electrical signal output from the crank angle sensor 102, and executes abnormality response control when either the angular acceleration calculated in this way or the throttle opening detected by the throttle opening detection system, i.e., calculated based on the electrical signal output from the throttle opening sensor 104, is outside a predetermined range defined for the other. This makes it possible to execute abnormality response control that responds to an abnormality in the throttle opening detection system with a simple configuration that does not use multiple throttle opening sensors.

[0026] Here, based on the inventor's finding that a correlation reliably exists between the angular acceleration value of the crankshaft, particularly during the compression stroke, of the internal combustion engine 1, and the throttle opening value when the throttle opening detection system including the throttle opening sensor 104 is normal, the control unit 151 is provided with a function for determining that the throttle opening detection system is normal if such a correlation is satisfied, and determining that the throttle opening detection system is abnormal otherwise. In this case, the reason why attention is focused on the angular acceleration value of the crankshaft, particularly during the compression stroke of the internal combustion engine 1 (compression stroke angular acceleration, which is angular deceleration) is that, during the compression stroke, the negative angular acceleration of the crankshaft, which corresponds to the compression resistance that increases as the throttle opening increases (the intake amount increases), can be reliably detected, and therefore a practical range in which the correlation exists between the angular acceleration value of the crankshaft and the throttle opening value can be reliably defined.

[0027] Furthermore, since the correlation between the angular acceleration of the crankshaft during the compression stroke and the throttle opening is relative, when determining whether the throttle opening detection system is normal depending on whether the angular acceleration of the crankshaft during the compression stroke is correlated with the throttle opening, the predetermined range of the angular acceleration of the crankshaft during the compression stroke that has an appropriate correlation with the throttle opening can be set to a range that is equal to or greater than a predetermined upper limit and equal to or less than a predetermined lower limit, each of which is set corresponding to the throttle opening. Furthermore, since the compression resistance tends to increase as the throttle opening increases, it is preferable to set the upper and lower limits of the compression stroke angular acceleration so that they decrease as the throttle opening increases.

[0028] On the other hand, if the normality of the throttle opening detection system is determined based on whether the throttle opening has an appropriate correlation with the angular acceleration of the crankshaft during the compression stroke, the predetermined range of throttle opening that has an appropriate correlation with the angular acceleration of the crankshaft during the compression stroke can be set to a range between a predetermined upper limit and a predetermined lower limit, each of which is defined corresponding to the angular acceleration of the crankshaft during the compression stroke. Furthermore, since the throttle opening tends to decrease as the compression resistance decreases, it is preferable to set the upper and lower limits of the throttle opening so that the corresponding upper and lower limits decrease as the angular acceleration of the crankshaft during the compression stroke increases.

[0029] <Example of Abnormality Response Control Processing> An example of abnormality response control processing in which the internal combustion engine control device 100 configured as described above executes abnormality response control will be described in detail below with further reference to FIGS. 2A to 3.

[0030] Fig. 2A is a flowchart showing an example of an abnormality response control process executed by the internal combustion engine control device 100 in this embodiment. Fig. 2B is a schematic diagram showing an example of table data used in the abnormality response control process executed by the internal combustion engine control device 100 in this embodiment. Fig. 3 is a flowchart showing an example of a compression stroke angular velocity calculation process in the abnormality response control process executed by the internal combustion engine control device 100 in this embodiment.

[0031] 2A typically starts when a power switch (not shown) of the vehicle is switched from an off state to an on state and the CPU 150 of the internal combustion engine control device 100 starts operating, and the abnormality response control process proceeds to the processing of step S1. Note that this abnormality response control process is executed repeatedly by reading the necessary control program and control data from memory at predetermined intervals, such as every 10 ms, while the CPU 150 is operating.

[0032] In the process of step S1, the control unit 151 calculates the throttle opening TH. Specifically, the control unit 151 calculates the throttle opening TH based on an electrical signal output from the throttle opening sensor 104 of the throttle opening detection system. This completes the process of step S1, and the abnormality response control process proceeds to the process of step S2.

[0033] In the process of step S2, the control unit 151 calculates upper and lower limit values ​​for the compression stroke angular acceleration ATCCP based on the throttle opening TH calculated in the process of step S1. Specifically, the control unit 151 reads the table data shown in FIG. 2B from memory and calculates the upper and lower limit values ​​for the compression stroke angular acceleration ATCCP that correspond to the value of the throttle opening TH calculated in the process of step S1. This completes the process of step S2, and the abnormality response control process proceeds to the process of step S3.

[0034] 2B, a two-axis Cartesian coordinate system is defined, with the horizontal axis representing the throttle opening TH and the vertical axis representing the compression stroke angular acceleration ATCCP (negative values). Upper and lower limits AU and AL for the compression stroke angular acceleration ATCCP are defined, each of which decreases as the throttle opening TH increases. The upper limit AU corresponds to the largest (negative) value among the values ​​of compression stroke angular acceleration ATCCP at which the compression stroke angular acceleration ATCCP is evaluated to have a practically appropriate correlation with the throttle opening TH. The lower limit AL corresponds to the smallest value among the values ​​of compression stroke angular acceleration ATCCP at which the compression stroke angular acceleration ATCCP is evaluated to have a practically appropriate correlation with the throttle opening TH. In other words, the range between the lower limit AL and the upper limit AU is the range at which the compression stroke angular acceleration ATCCP is evaluated to have a practically appropriate correlation with the throttle opening TH. For example, if the throttle opening TH calculated in step S1 is TH1, the upper limit AU and lower limit AL of the compression stroke angular acceleration ATCCP corresponding to the throttle opening TH value TH1 are AU1 and AL1, respectively, and therefore the upper limit AU and lower limit AL are calculated as the upper limit AU and lower limit AL of the compression stroke angular acceleration ATCCP corresponding to the throttle opening TH value TH1. Note that in the figure, the upper limit AU and lower limit AL are shown as values ​​forming a continuous straight line for convenience, but they may also be values ​​forming a continuous curve or a set of multiple discrete points (values).

[0035] In the process of step S3, the control unit 151 calculates the compression stroke angular acceleration ATCCP. Specifically, the control unit 151 calculates the compression stroke angular acceleration ATCCP by executing the compression stroke angular acceleration calculation process shown in Fig. 3. This completes the process of step S3, and the abnormality response control process proceeds to the process of step S4.

[0036] 3, the flowchart shown in FIG. 3 starts when step S3 of the flowchart of the abnormality response control process shown in FIG. 2A starts, and the compression stroke angular acceleration calculation process proceeds to step S11. The compression stroke angular acceleration calculation process is repeatedly executed by the control unit 151 by reading the necessary control program and control data from memory each time step S3 of the flowchart of the abnormality response control process shown in FIG. 2A starts.

[0037] In the process of step S11, the control unit 151 detects the position of the piston 4 of the internal combustion engine 1 based on the electrical signal input from the crank angle sensor 102, determines whether or not it is at exhaust top dead center, and acquires the timing. If the result of the determination is that the piston 4 of the internal combustion engine 1 is at exhaust top dead center, the current series of compression stroke angular acceleration calculation processes ends. On the other hand, if the piston 4 of the internal combustion engine 1 is not at exhaust top dead center, the compression stroke angular acceleration calculation process proceeds to the process of step S12.

[0038] In the process of step S12, the control unit 151 detects the position of the piston 4 of the internal combustion engine 1 based on the electrical signal input from the crank angle sensor 102, and determines whether or not it is at the intake bottom dead center. If the result of the determination is that the position of the piston 4 of the internal combustion engine 1 is at the intake bottom dead center, the control unit 151 advances the compression stroke angular acceleration calculation process to the process of step S13. On the other hand, if the position of the piston 4 of the internal combustion engine 1 is not at the intake bottom dead center, the control unit 151 advances the compression stroke angular acceleration calculation process to the process of step S14.

[0039] In the process of step S13, the control unit 151 calculates and acquires the time interval between the timing of the exhaust top dead center acquired in the process of step S11 in the previous compression stroke angular acceleration calculation process and the timing of the intake bottom dead center acquired in the process of step S12 as the stroke time TCSC of the intake stroke of the internal combustion engine 1. This completes the process of step S13, and the compression stroke angular acceleration calculation process proceeds to the process of step S15.

[0040] In the process of step S15, the control unit 151 divides the crank angle of 180° (180 CA) by the stroke time TCSC of the intake stroke acquired in the process of step S13 to calculate the angular velocity VTCSC of the intake stroke of the internal combustion engine 1. This completes the process of step S15, and the current series of compression stroke angular acceleration calculation processes ends.

[0041] Meanwhile, in the processing of step S14, the control unit 151 detects the position of the piston 4 of the internal combustion engine 1 based on the electrical signal input from the crank angle sensor 102, and determines whether or not it is at compression top dead center. If the result of the determination is that the position of the piston 4 of the internal combustion engine 1 is at compression top dead center, the control unit 151 advances the compression stroke angular acceleration calculation processing to the processing of step S16. On the other hand, if the position of the piston 4 of the internal combustion engine 1 is not at compression top dead center, the current series of compression stroke angular acceleration calculation processing ends.

[0042] In the process of step S16, the control unit 151 calculates and acquires the time interval between the timing of the intake bottom dead center acquired in the process of step S12 in the previous compression stroke angular acceleration calculation process and the timing of the compression top dead center acquired in the process of step S14 as the stroke time TCPP of the compression stroke of the internal combustion engine 1. This completes the process of step S16, and the compression stroke angular acceleration calculation process proceeds to the process of step S17.

[0043] In the process of step S17, the control unit 151 divides the crank angle of 180° (180 CA) by the stroke time TCPP of the compression stroke acquired in the process of step S16 to calculate the angular velocity VTCCP of the compression stroke of the internal combustion engine 1. This completes the process of step S17, and the compression stroke angular acceleration calculation process proceeds to the process of step S18.

[0044] In the process of step S18, the control unit 151 subtracts the intake stroke angular velocity VTCSC calculated in the process of step S15 of the previous compression stroke angular acceleration calculation process from the compression stroke angular velocity VTCCP calculated in the process of step S17 to calculate the compression stroke angular velocity difference DVCPSC of the internal combustion engine 1. This completes the process of step S18, and the compression stroke angular acceleration calculation process proceeds to the process of step S19.

[0045] In the process of step S19, the control unit 151 divides the compression stroke angular velocity difference DVCPSC calculated in the process of step S18 by the compression stroke time TCPP acquired in the process of step S16 to calculate the compression stroke angular acceleration ATCCP of the internal combustion engine 1. This completes the process of step S19, and the current series of compression stroke angular acceleration calculation processes ends.

[0046] 2A again, in the process of step S4, the control unit 151 determines whether the compression stroke angular acceleration ATCCP is equal to or less than the upper limit value AU. Specifically, the control unit 151 determines whether the value of the compression stroke angular acceleration ATCCP calculated in the process of step S3 is equal to or less than the upper limit value AU in the table data shown in FIG. 2B read from memory. For example, if the value of the throttle opening TH calculated in the process of step S1 this time is TH1, the control unit 151 determines whether the value of the compression stroke angular acceleration ATCCP is equal to or less than the upper limit value AU1 of the compression stroke angular acceleration ATCCP corresponding to the throttle opening TH value TH1. If the result of the determination is that the value of the compression stroke angular acceleration ATCCP is equal to or less than the upper limit value AU in the table data shown in FIG. 2B read from memory (step S4: Yes), the value of the compression stroke angular acceleration ATCCP may be within a range evaluated to exhibit a practically appropriate correlation with the throttle opening TH, and the control unit 151 proceeds to the process of step S5 in the abnormality response control process. On the other hand, if the value of the compression stroke angular acceleration ATCCP is not less than the upper limit value AU (is greater than the upper limit value AU) (step S4: No), the value of the compression stroke angular acceleration ATCCP is outside the range evaluated as exhibiting a practically appropriate correlation with the throttle opening TH, so the control unit 151 proceeds with the abnormality response control processing to step S6.

[0047] In step S5, the control unit 151 determines whether the compression stroke angular acceleration ATCCP is equal to or greater than a lower limit AL. Specifically, the control unit 151 determines whether the value of the compression stroke angular acceleration ATCCP calculated in step S3 is equal to or greater than a lower limit AL in the table data shown in FIG. 2B read from memory. For example, if the value of the throttle opening TH calculated in step S1 this time is TH1, the control unit 151 determines whether the value of the compression stroke angular acceleration ATCCP is equal to or greater than a lower limit AL1 of the compression stroke angular acceleration ATCCP corresponding to the throttle opening TH value TH1. If the determination result shows that the value of the compression stroke angular acceleration ATCCP is equal to or greater than the lower limit AL in the table data shown in FIG. 2B read from memory (step S5: Yes), the value of the compression stroke angular acceleration ATCCP is within a range evaluated to exhibit a practically appropriate correlation with the throttle opening TH, and the current series of abnormality response control processes is terminated. On the other hand, if the value of the compression stroke angular acceleration ATCCP is not greater than or equal to the lower limit value AL (is less than the lower limit value AL) (step S5: No), the value of the compression stroke angular acceleration ATCCP is outside the range evaluated as exhibiting a practically appropriate correlation with the throttle opening TH, so the control unit 151 proceeds with the abnormality response control processing to step S6.

[0048] In the process of step S6, the control unit 151 executes abnormality response control. Specifically, the control unit 151 executes all or part of the following: stopping the ignition operation of the spark plug 10; stopping the fuel injection operation of the fuel injection valve 13; and, if the throttle device 14 is electronically controlled, setting the throttle opening of the throttle valve 14a to the fully closed position. This completes the process of step S6, and the current series of abnormality response control processes ends.

[0049] <Another example of abnormality response control processing> Furthermore, since other examples of the abnormality response control processing in which the internal combustion engine control device 100 executes abnormality response control are also possible, such other examples will be described in detail below with further reference to Figures 4A and 4B.

[0050] Fig. 4A is a flowchart showing another example of the abnormality response control process executed by the internal combustion engine control device 100 according to this embodiment. Also, Fig. 4B is a schematic diagram showing another example of table data used in the abnormality response control process executed by the internal combustion engine control device 100 according to this embodiment.

[0051] 3A typically starts when a power switch (not shown) of the vehicle is switched from an off state to an on state and the CPU 150 of the internal combustion engine control device 100 starts operating, and the abnormality response control process proceeds to the processing of step S21. Note that this abnormality response control process is executed repeatedly by reading the necessary control program and control data from memory at predetermined intervals, such as every 10 ms, while the CPU 150 is operating.

[0052] In the process of step S21, the control unit 151 calculates the compression stroke angular acceleration ATCCP. Specifically, the control unit 151 calculates the compression stroke angular acceleration ATCCP by executing the compression stroke angular acceleration calculation process shown in FIG. 3. This compression stroke angular acceleration calculation process is the same as that in the example of the abnormality response control process, so a detailed description thereof will be omitted. This completes the process of step S21, and the abnormality response control process proceeds to the process of step S22.

[0053] In the process of step S22, the control unit 151 calculates upper and lower limit values ​​for the throttle opening TH based on the compression stroke angular acceleration ATCCP calculated in the process of step S21. Specifically, the control unit 151 reads the table data shown in FIG. 4B from memory and calculates the upper and lower limit values ​​for the throttle opening TH that correspond to the value of the compression stroke angular acceleration ATCCP calculated in the process of step S21. This completes the process of step S22, and the abnormality response control process proceeds to the process of step S23.

[0054] 4B, a two-axis Cartesian coordinate system is defined in which the horizontal axis represents the compression stroke angular acceleration ATCCP (negative values) and the vertical axis represents the throttle opening TH. Upper and lower limits TU and TL of the throttle opening TH are defined, each of which decreases as the value (negative value) of the compression stroke angular acceleration ATCCP increases. The upper limit TU corresponds to the largest value of the throttle opening TH at which the throttle opening TH is evaluated to have a practically appropriate correlation with the compression stroke angular acceleration ATCCP, and the lower limit TL corresponds to the smallest value of the throttle opening TH at which the throttle opening TH is evaluated to have a practically appropriate correlation with the compression stroke angular acceleration ATCCP. In other words, the range between the lower limit TL and the upper limit TU is the range at which the throttle opening TH is evaluated to have a practically appropriate correlation with the compression stroke angular acceleration ATCCP. For example, if the value of the compression stroke angular acceleration ATCCP calculated in the current processing of step S21 is ATCCP1, the upper limit value TU and the lower limit value TL of the throttle opening TH corresponding to the value ATCCP1 of the compression stroke angular acceleration ATCCP are the upper limit value TU1 and the lower limit value TL1, so the upper limit value TU and the lower limit value TL1 of the throttle opening TH corresponding to the value ATCCP1 of the compression stroke angular acceleration ATCCP are calculated as the upper limit value TU and the lower limit value TL1. Note that in the figure, the upper limit value TU and the lower limit value TL are shown as values ​​that form a continuous straight line for convenience, but they may also be values ​​that form a continuous curve or a set of a plurality of discrete points (values).

[0055] In the process of step S23, the control unit 151 calculates the throttle opening TH. Specifically, the control unit 151 calculates the throttle opening TH based on an electrical signal output from the throttle opening sensor 104 of the throttle opening detection system. This completes the process of step S23, and the abnormality response control process proceeds to the process of step S24.

[0056] In step S24, the control unit 151 determines whether the throttle opening TH is equal to or less than the upper limit TU. Specifically, the control unit 151 determines whether the throttle opening TH calculated in step S23 is equal to or less than the upper limit TU in the table data shown in FIG. 4B read from memory. For example, if the compression stroke angular acceleration ATCCP calculated in step S21 is ATCCP1, the control unit 151 determines whether the throttle opening TH is equal to or less than the upper limit TU1 of the throttle opening TH corresponding to the compression stroke angular acceleration ATCCP1. If the determination result shows that the throttle opening TH is equal to or less than the upper limit TU in the table data shown in FIG. 2B read from memory (step S24: Yes), the throttle opening TH may be within a range evaluated as exhibiting a practically appropriate correlation with the compression stroke angular acceleration ATCCP. Therefore, the control unit 151 advances the abnormality response control process to step S25. On the other hand, if the value of the throttle opening TH is not less than the upper limit value TU (greater than the upper limit value TU) (step S24: No), the throttle opening TH is outside the range evaluated as exhibiting a practically appropriate correlation with the compression stroke angular acceleration ATCCP, so the control unit 151 proceeds with the abnormality response control processing to step S26.

[0057] In step S25, the control unit 151 determines whether the throttle opening TH is equal to or greater than the lower limit TL. Specifically, the control unit 151 determines whether the throttle opening TH calculated in step S23 is equal to or greater than the lower limit TL in the table data shown in FIG. 4B read from memory. For example, if the compression stroke angular acceleration ATCCP calculated in step S21 this time is ATCCP1, the control unit 151 determines whether the throttle opening TH is equal to or greater than the lower limit TL1 of the throttle opening TH corresponding to the compression stroke angular acceleration ATCCP1. If the determination result shows that the throttle opening TH is equal to or greater than the lower limit TL in the table data shown in FIG. 2B read from memory (step S25: Yes), the throttle opening TH is within a range evaluated as exhibiting a practically appropriate correlation with the compression stroke angular acceleration ATCCP, and the current series of abnormality response control processes is terminated. On the other hand, if the value of the throttle opening TH is not greater than or equal to the lower limit TL (is less than the lower limit TL) (step S25: No), the throttle opening TH is outside the range evaluated as exhibiting a practically appropriate correlation with the compression stroke angular acceleration ATCCP, so the control unit 151 proceeds with the abnormality response control processing to step S26.

[0058] In the process of step S26, the control unit 151 executes abnormality response control. Specifically, the control unit 151 executes all or part of the following: stopping the ignition operation of the spark plug 10; stopping the fuel injection operation of the fuel injection valve 13; and, if the throttle device 14 is electronically controlled, setting the throttle opening of the throttle valve 14a to the fully closed position. This completes the process of step S26, and ends the current series of abnormality response control processes.

[0059] In the first aspect of the internal combustion engine control device 100 in this embodiment described above, the control unit 151 executes abnormality response control when either the angular acceleration ATCCP of the crankshaft during the compression stroke of the internal combustion engine 1 or the throttle opening TH detected by the throttle opening detection system including the throttle opening sensor 104 is outside a predetermined range for the one defined corresponding to the other, so that abnormality response control that responds to an abnormality in the throttle opening detection system can be executed with a simple configuration that does not use multiple throttle opening sensors.

[0060] Furthermore, in the second aspect of the internal combustion engine control device 100 of this embodiment, in addition to the first aspect, the predetermined range is a range that is less than an upper limit value AU and greater than a lower limit value AL specified for the angular acceleration ATCCP corresponding to the throttle opening TH, and the control unit 151 executes abnormality response control when the angular acceleration ATCCP is outside this predetermined range.Therefore, with a simple configuration that does not use multiple throttle opening sensors, abnormality response control that responds to abnormalities in the throttle opening detection system can be appropriately executed.

[0061] Furthermore, in a third aspect of the internal combustion engine control device 100 of this embodiment, in addition to the second aspect, the upper and lower limit values ​​in the specified range are set to decrease as the throttle opening TH increases, so that the specified range can be set appropriately.

[0062] In addition, in a fourth aspect of the internal combustion engine control device 100 in this embodiment, in addition to either the second or third aspect, since the upper limit value AU of the specified range is a negative value, it is possible to set a specified range using angular acceleration ATCCP that reflects compression resistance.

[0063] Furthermore, in a fifth aspect of the internal combustion engine control device 100 of this embodiment, in addition to the first aspect, the predetermined range is a range that is less than an upper limit value TU and greater than a lower limit value TL that are respectively specified for the throttle opening TH corresponding to the angular velocity ATCCP, and the control unit 151 executes abnormality response control when the throttle opening TH is outside this predetermined range.Therefore, with a simple configuration that does not use multiple throttle opening sensors, abnormality response control that responds to abnormalities in the throttle opening detection system can be appropriately executed.

[0064] Furthermore, in a sixth aspect of the internal combustion engine control device 100 of this embodiment, in addition to the fifth aspect, the upper and lower limit values ​​in the specified range are set to decrease as the angular velocity ATCCP increases, so that the specified range can be set appropriately.

[0065] The present invention is not limited to the above-described embodiments in terms of the type, shape, arrangement, number, etc. of the components, and it goes without saying that the components can be appropriately modified within the scope of the gist of the invention, such as by appropriately replacing them with components that have equivalent effects.

[0066] As described above, the present invention provides an internal combustion engine control device that can execute abnormality response control to respond to abnormalities in the throttle opening detection system with a simple configuration that does not use multiple throttle opening sensors, and because of its general-purpose, universal nature, it is expected to be widely applicable to internal combustion engine control devices for motorcycles.

[0067] DESCRIPTION OF SYMBOLS 1...internal combustion engine 2...cylinder block 2a...cylinder 3...coolant passage 4...piston 5...connecting rod 6...crankshaft 7...reluctor 7a...tooth portion 8...cylinder head 9...combustion chamber 10...spark plug 11...intake pipe 11a...intake passage 12...intake valve 13...fuel injection valve 14...throttle device 14a...throttle valve 15...exhaust pipe 15a...exhaust passage 16...exhaust valve 17...catalyst 100...internal combustion engine control device 101...water temperature sensor 102...crank angle sensor 103...intake pressure sensor 104...throttle opening sensor 105...O2 sensor 106...accelerator opening sensor 107...vehicle speed sensor 150...CPU 151...control unit

Claims

1. An internal combustion engine control device equipped with a control unit that executes abnormality response control in response to an abnormality in a throttle opening detection system that detects the throttle opening, which is the opening of the throttle valve of an internal combustion engine, wherein the control unit calculates the angular acceleration of the crankshaft during the compression stroke of the internal combustion engine, and executes the abnormality response control when either the calculated angular acceleration or the throttle opening detected by the throttle opening detection system is outside a predetermined range defined for the other.

2. The internal combustion engine control device described in claim 1, characterized in that the predetermined range is a range below an upper limit value and above a lower limit value specified for the angular acceleration corresponding to the throttle opening, and the control unit executes the abnormality response control when the angular acceleration is outside the predetermined range.

3. An internal combustion engine control device according to claim 2, wherein said upper limit value and said lower limit value in said predetermined range each become smaller as said throttle opening degree becomes larger.

4. The internal combustion engine control device according to claim 2 or 3, characterized in that the upper limit value is a negative value.

5. The internal combustion engine control device described in claim 1, characterized in that the predetermined range is a range below an upper limit value and above a lower limit value specified for the throttle opening corresponding to the angular velocity, and the control unit executes the abnormality response control when the throttle opening is outside the predetermined range.

6. An internal combustion engine control device according to claim 5, wherein said upper limit value and said lower limit value in said predetermined range each become smaller as said angular velocity increases.

Images