Throttle opening detector

Abstract

To set an appropriate throttle closure value even when power generated by operating an internal combustion engine is supplied to a control unit without a battery.SOLUTION: A fuel injection control system 10 comprises an ECU 14 configured so that power generated by operating of an engine 12 can be supplied not via a battery. When the power generated by operating the engine 12 is supplied to the ECU 14 without the battery, a detection value VDTC of a throttle opening sensor 46 is set to a throttle closure value VCLS, which indicates that a throttle valve 38 is closed, until a predetermined condition is satisfied after the ECU 14 is started even when the detection value VDTC is not a minimum value after the ECU 14 is started.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a throttle opening detection device, and more particularly to a throttle opening detection device including a control unit configured to be able to supply electric power generated by the operation of an internal combustion engine without going through a battery. [Background technology]

[0002] An internal combustion engine is provided with a throttle valve for controlling intake air and a throttle opening sensor for detecting the opening of the throttle valve. The opening of the throttle valve is calculated using the detected value of the throttle opening sensor, with a throttle closure value indicating that the throttle valve is closed as a reference. A throttle valve opening detection device for an engine has been proposed (see Patent Document 1), which calculates the throttle closure value by increasing or decreasing the counter value of a learning value update request counter depending on whether the difference between the detected throttle valve opening and a throttle valve fully closed learned value is equal to or greater than a predetermined value, and updates the throttle valve fully closed learned value when the counter value reaches a predetermined set count value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 02-016349 Summary of the Invention [Problem to be solved by the invention]

[0004] Vehicles are equipped with an electronic control unit (ECU), which is a microcomputer, and the ECU updates the throttle opening value. However, there are cases where the vehicle is battery-less, or where the battery runs out and is unable to supply power to the ECU. To achieve appropriate throttle opening control in such cases, there is a technology that supplies power generated by the internal combustion engine to the ECU without going through the battery. However, after the ECU is started, it takes a short time for the generated voltage to reach a steady voltage at which the ECU operates normally. During this time, the detected value of the throttle opening sensor is lower than when a steady voltage is supplied to the ECU. If the throttle opening value is updated in such a case, the throttle opening value may be set to a value lower than the throttle opening value that should be set when a steady voltage is supplied to the ECU, making it difficult to control the throttle opening appropriately.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to set an appropriate throttle closing value even when the electric power generated by the operation of the internal combustion engine is supplied to the control unit without going through a battery. [Means for solving the problem]

[0006] In order to solve the above problems, a throttle opening detection device according to the present invention includes a control unit configured to allow electric power generated by operation of an internal combustion engine to be supplied without a battery. When electric power generated by operation of the internal combustion engine is supplied without a battery, the control unit sets the detected value of the throttle opening sensor to a throttle closed value indicating that the throttle valve is closed until a predetermined condition is satisfied after activation of the control unit, even if the detected value is not the minimum value after activation of the control unit.

[0007] According to this aspect, even if the throttle closing value is set to a value lower than the original value before the voltage applied to the control unit reaches a steady voltage, the throttle closing value can be updated to a more appropriate value thereafter, thereby enabling appropriate throttle opening control even when power generated by the operation of the internal combustion engine is supplied to the control unit without going through a battery.

[0008] The predetermined condition may be a condition that indicates that the voltage applied to the throttle position sensor after the control unit is started has reached a steady voltage at which the throttle position sensor operates steadily. According to this aspect, the throttle closing value can be continuously updated until the voltage applied to the control unit reaches the steady voltage. Therefore, the throttle closing value can be updated to a more appropriate value.

[0009] The predetermined condition may be that a predetermined time has elapsed since the control unit was started. The voltage applied to the control unit reaches a steady voltage at approximately the same time each time the internal combustion engine is started. According to this aspect, the throttle closing value can be updated to an appropriate value by simply counting the time after the control unit is started.

[0010] The control unit may avoid setting the detected value of the throttle opening sensor as the throttle closing value when the detected value of the throttle opening sensor exceeds a predetermined upper limit value.

[0011] Even if the voltage applied to the control unit has not yet reached a steady voltage immediately after the internal combustion engine has started, if the detected value of the throttle opening sensor is high, the throttle valve may be open. According to this aspect, it is possible to avoid setting the detected value of the throttle opening sensor when the throttle valve is open as the throttle closing value.

[0012] The control unit may set the throttle closing value to a predetermined upper limit when the detected value of the throttle opening sensor exceeds the predetermined upper limit. According to this aspect, it is possible to prevent the throttle closing value from being set to a value lower than the throttle closing value that should be set, and not being updated.

[0013] After the predetermined condition is satisfied, the control unit may set the minimum value of the detected values ​​of the throttle opening sensor after startup of the control unit as the throttle closing value. It is considered that a steady voltage is applied to the control unit after the predetermined condition is satisfied. Therefore, if the minimum value of the detected values ​​of the throttle opening sensor after startup of the control unit is detected after the predetermined condition is satisfied, that minimum value is considered to be an accurate value, and therefore, the minimum value is considered to be the throttle closing value. Therefore, according to this aspect, the throttle closing value can be updated to an appropriate value after the predetermined condition is satisfied. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram showing a configuration of a fuel injection control system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram illustrating an ECU and components connected to the ECU. [Figure 3] 10 is a flowchart showing a process for updating a throttle closing value. DETAILED DESCRIPTION OF THE INVENTION

[0015] FIG. 1 is a diagram showing the configuration of a fuel injection control system 10 according to this embodiment. The fuel injection control system 10 has an engine 12 and an ECU 14. The engine 12 is an internal combustion engine prime mover, and has a cylinder 16, a piston 18, a connecting rod 20, and a crankshaft 22. The piston 18 is housed in a cylinder chamber 26 of the cylinder 16. The piston 18 is connected to the crankshaft 22 via the connecting rod 20. The axial reciprocating motion of the piston 18 is converted into rotational motion of the crankshaft 22 via the connecting rod 20.

[0016] A combustion chamber 28 is formed on the tip side of the piston 18. An intake port 30 and an exhaust port 32 are connected to the combustion chamber 28. An intake valve 34 is disposed between the intake port 30 and the combustion chamber 28, and an exhaust valve 36 is disposed between the exhaust port 32 and the combustion chamber 28. The intake valve 34 regulates the flow of air from the intake port 30 to the combustion chamber 28, and the exhaust valve 36 regulates the flow of air from the combustion chamber 28 to the exhaust port 32.

[0017] A throttle valve 38 is rotatably disposed inside the intake port 30. The throttle valve 38 changes its opening as it rotates, thereby adjusting the amount of air supplied to the combustion chamber 28. The throttle valve 38 is configured so that its opening changes depending on the amount of accelerator depression by the driver.

[0018] The engine 12 further includes a spark plug 40, an ignition coil 42, a fuel injector 44, a throttle position sensor 46, an intake pressure sensor 48, and a pulser 50. The spark plug 40 is disposed in the combustion chamber 28 with its ignition portion facing the top surface of the piston 18. The spark plug 40 is connected to the ECU 14 via the ignition coil 42. The ECU 14 controls the supply of power to the spark plug 40, thereby controlling ignition by the spark plug 40 and combustion in the combustion chamber 28.

[0019] The fuel injection valve 44, throttle position sensor 46, intake pressure sensor 48, and pulser 50 are also connected to the ECU 14. The fuel injection valve 44 is disposed in the wall of the intake port 30 so as to inject fuel into the intake port 30. The ECU 14 adjusts the amount of fuel injected into the intake port 30 by controlling the drive signal given to the fuel injection valve 44. The throttle position sensor 46 is disposed near the throttle valve 38 and detects the opening of the throttle valve 38. The detection result of the throttle valve 38 is input to the ECU 14.

[0020] The intake pressure sensor 48 is disposed on the wall of the intake port 30 so as to detect the intake pressure inside the intake port 30. The detection result of the intake pressure sensor 48 is input to the ECU 14.

[0021] The pulser 50 generates a pulse signal in response to the rotational movement of the crankshaft 22. The pulse signal generated by the pulser 50 is input to the ECU 14. The ECU 14 uses this pulse signal to calculate the rotation angle of the crankshaft 22 and the engine speed. Therefore, the pulser 50 functions as an engine speed sensor.

[0022] 2 is a block diagram showing the ECU 14 and components connected to the ECU 14. The ECU 14 is a so-called microcomputer and includes a processing unit 60 and a storage unit 62. The storage unit 62 includes a writable RAM 64 and a non-writable ROM 66. The processing unit 60 performs calculations required for drive control of the engine 12 based on detection results from various sensors connected to the ECU 14, using tables stored in the ROM 66, etc. The calculated values ​​are stored in the RAM 64.

[0023] The ECU 14 controls the amount of fuel injected from the fuel injection valve 44 based on the detection results of the throttle opening sensor 46, the intake pressure sensor 48, and the pulser 50, i.e., the throttle opening, the intake pressure, and the engine speed. Thus, the ECU 14 functions as a fuel injection control device.

[0024] The ECU 14 receives the detected value V of the throttle opening sensor 46. DTC The ECU 14 updates the throttle closing value based on the detected value V of the throttle opening sensor 46. DTC and the updated throttle closing value V CLS The ECU 14 calculates the opening of the throttle valve 38 using the above formula. Therefore, the ECU 14 also functions as a throttle opening detection device.

[0025] In this embodiment, power is normally supplied to the ECU 14 from a battery (not shown). While power is being supplied from the battery to the ECU 14, a stable steady voltage is supplied to the ECU 14. In this embodiment, the steady voltage is set to 5V. However, there are cases where the battery runs out.

[0026] However, if the battery runs out, power cannot be supplied from the battery to the ECU 14 until the battery is recharged. To achieve appropriate throttle opening control even in such a case, in this embodiment, the ECU 14 is configured to be able to receive power generated by the operation of the engine 12 without going through the battery. Specifically, the ECU 14 is configured to be able to receive power directly from a generator (not shown) that generates power through the operation of the engine 12. The ECU 14 determines whether the battery is dead based on the voltage provided by the battery, etc., immediately after startup of the ECU 14. If the ECU 14 determines that the battery is dead, it starts up using the power supplied from the generator. Since such technology is well known, detailed configuration thereof will not be described here.

[0027] However, it takes a short time for the generated voltage to reach a steady voltage at which the ECU 14 operates normally after the ECU 14 is started. In this way, until the voltage applied to the ECU 14 reaches the steady voltage, the detected value V of the throttle opening sensor 46 DTC In this case, the throttle closing value V CLSWhen the constant voltage is applied to the ECU 14, the throttle closing value V CLS Throttle closing value V CLS may be set.

[0028] Therefore, in this embodiment, even when the electric power generated by the operation of the engine 12 is supplied to the ECU 14 without going through the battery, an appropriate throttle closing value V CLS Configurable throttle closing value V CLS The throttle closing value V is updated as follows using the flowchart. CLS The update process will be explained in detail.

[0029] Figure 3 shows the throttle closing value V CLS 10 is a flowchart showing an update process of the ECU 14. The process in this flowchart is repeatedly executed at predetermined time intervals after the ECU 14 is started and predetermined initialization is completed.

[0030] ECU14 starts counter C START (S10) Start counter C START When the count is incremented, the ECU 14 starts the start counter C START Start counter C, calculated from START The time from the start of counting is the control switching time T CNG It is determined whether it is smaller than (S12).

[0031] Start Counter C START The time from the start of counting is the control switching time T CNG If it is determined that the detected value V of the throttle opening sensor 46 is smaller than the normal voltage (YES in S12), it is considered that the voltage applied to the ECU 14 has not reached the normal voltage. DTC is a predetermined upper limit value V LMT It is determined whether the upper limit value V is smaller than the upper limit value V (S14). LMT is the value detected by the throttle opening sensor 46, V DTCThe upper limit value V is a value that has been experimentally determined in advance as a value at which the throttle valve 38 is considered to be open even while the voltage applied to the ECU 14 has not yet reached a steady voltage. LMT is stored in ROM66.

[0032] Throttle opening sensor 46 detection value V DTC is a predetermined upper limit value V LMT If it is determined that the value is smaller than the threshold value V (YES in S14), the ECU 14 DTC The throttle closing value V CLS Specifically, the ECU 14 sets the detected value V of the throttle opening sensor 46 to DTC The throttle closing value V CLS The detected value V of the throttle opening sensor 46 is stored in the RAM 64. DTC is the throttle closing value V CLS When this is set, the processing in this flowchart is temporarily terminated.

[0033] In this way, when the electric power generated by the operation of the engine 12 is supplied without going through the battery, the ECU 14 does not detect the detected value V of the throttle opening sensor 46 until a predetermined condition is met after the start of the ECU 14. DTC Even if the detected value V of the throttle opening sensor 46 is not the minimum value after the start of the ECU 14, DTC a throttle closing value V indicating that the throttle valve 38 is closed; CLS As a result, the throttle closing value V that should be set is set to the normal value before the voltage applied to the ECU 14 reaches the steady voltage. CLS Throttle closure value V CLS Even if the throttle closing value V is set, CLS Therefore, even when the electric power generated by the operation of the engine 12 is supplied to the ECU 14 without going through the battery, the opening degree of the throttle valve 38 can be appropriately controlled.

[0034] In this embodiment, the predetermined condition is a condition under which it can be assumed that the voltage applied to the throttle opening sensor 46 after the start of the ECU 14 has reached a steady voltage at which the throttle opening sensor 46 operates steadily. Specifically, the predetermined condition is that a predetermined time has elapsed after the start of the ECU 14. In this embodiment, the predetermined time is the time after the start of the ECU 14 when initialization is completed and the start counter C START The predetermined time is calculated from these times as the time when the throttle opening sensor 46 reaches a steady voltage at which it operates normally, and is stored in the ROM 66. The predetermined time is calculated from these times as the time when the throttle opening sensor 46 can be considered to have reached a steady voltage at which it operates normally, and is stored in the ROM 66. The predetermined time is calculated from these times as the time when the throttle opening sensor 46 reaches ...

[0035] Throttle opening sensor 46 detection value V DTC is a predetermined upper limit value V LMT If it is determined that the upper limit value V LMT The throttle closing value V CLS Specifically, the ECU 14 sets the upper limit value V LMT The throttle closing value V CLS The upper limit value V is stored in RAM64. LMT is the throttle closing value V CLS When this is set, the processing in this flowchart is temporarily terminated.

[0036] In this way, the ECU 14 determines the detected value V of the throttle opening sensor 46. DTC exceeds a predetermined upper limit, the detected value V of the throttle opening sensor 46 DTC The throttle closing value V CLS Even if the voltage applied to the ECU 14 has not yet reached a steady voltage immediately after the ECU 14 is started, the detected value V of the throttle opening sensor 46 is set to DTCWhen the throttle valve 38 is open, the throttle opening sensor 46 detects a value V DTC The throttle closing value V CLS This can avoid setting

[0037] In this embodiment, the ECU 14 detects the detected value V of the throttle opening sensor 46. DTC is a predetermined upper limit value V LMT If it exceeds the upper limit V LMT The throttle closing value V CLS Specifically, the ECU 14 sets the upper limit value V LMT The throttle closing value V CLS and store it in RAM64.

[0038] Start Counter C START Start counter C, calculated from START The time from the start of counting is the control switching time T CNG If it is determined that the voltage applied to the ECU 14 is equal to or greater than the normal voltage (N in S12), it is considered that the voltage applied to the ECU 14 has reached a steady voltage. In this case, the ECU 14 determines whether the detected value V DTC is the throttle closing value V CLS It is determined whether the detected value V of the throttle opening sensor 46 is smaller than DTC is the throttle closing value V CLS If it is determined that the value V detected by the throttle opening sensor 46 is smaller than the threshold (YES in S20), the ECU 14 DTC The throttle closing value V CLS That is, the ECU 14 sets the control switching time T CNG After the time has elapsed, the detected value V of the throttle opening sensor 46 after the start of the ECU 14 DTC The minimum value of V is the throttle closing value. CLS The ECU 14 sets the detected value V DTC The throttle closing value V CLS The detected value V of the throttle opening sensor 46 is stored in the RAM 64. DTC is the throttle closing value VCLS When this is set, the processing in this flowchart is temporarily terminated.

[0039] Control switching time T CNG After the control switching time T CNG After the time has elapsed, the detected value V of the throttle opening sensor 46 after the start of the ECU 14 DTC If a minimum value of is found, it is considered to be the correct value and is used as the throttle closing value V. CLS Therefore, according to this embodiment, the control switching time T CNG After the elapse of time, the throttle closing value V CLS can be updated to the appropriate value.

[0040] Even when the battery can supply power to the ECU 14, the ECU 14 detects the throttle opening sensor 46 after the ECU 14 is started. DTC The minimum value of V is the throttle closing value. CLS Specifically, the ECU 14 sets the detected value V of the throttle opening sensor 46 to DTC The minimum value of the throttle closing value V CLS When power can be supplied from the battery to the ECU 14, it is considered that a steady voltage is being applied to the ECU 14. Therefore, in this case, the detected value V of the throttle opening sensor 46 is also DTC The minimum value of V is the throttle closing value. CLS As a result, even when power can be supplied from the battery to the ECU 14, the throttle closing value V CLS can be updated to the appropriate value.

[0041] Throttle opening sensor 46 detection value V DTC is the throttle closing value V CLS If it is determined that the value is equal to or greater than the threshold value V (N in S20), it is considered that the throttle valve 38 is open. CLS The process in this flowchart is temporarily terminated without updating the value.

[0042] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-described embodiments, and suitable combinations and substitutions of the configurations of the embodiments are also included in the present invention. Furthermore, it is possible to appropriately rearrange the combinations and processing orders in the embodiments based on the knowledge of a person skilled in the art, and to make modifications to the embodiments, such as various design changes, and such modified embodiments are also included in the scope of the present invention.

[0043] In one modification, the ECU 14 is configured to receive power generated by the operation of the engine 12 without going through a battery. Specifically, although the vehicle is equipped with the above-mentioned batteries, the ECU 14 does not receive power from these batteries, but operates by receiving power from a generator that generates power through the operation of the engine 12. Regardless of whether these batteries are dead or not, the ECU 14 calculates the throttle closing value V shown in FIG. 3 every time the engine 12 starts. CLS As a result, even when the ECU 14 is configured so that the power generated by the operation of the engine 12 is supplied without going through a battery, the throttle closing value V CLS can be updated to the appropriate value.

[0044] In another variant, the ECU 14 is installed in a battery-less vehicle. Battery-less vehicles are well known, and therefore a detailed description of their configuration will be omitted. In this case, the ECU 14 also calculates the throttle closing value V shown in FIG. 3 each time the engine 12 is started. CLS As a result, even when the ECU 14 is installed in a battery-less vehicle, the ECU 14 can update the throttle closing value V CLS can be updated to the appropriate value.

[0045] In another modified example, the ECU 14 calculates the rotation angle of the crankshaft 22 based on the detection result of the pulser 50. In S12 of FIG. STARTThe time from the start of counting is the control switching time T CNG Rather than determining whether the rotation angle of the crankshaft 22 is smaller than the predetermined control switching angle, the system determines whether the rotation angle of the crankshaft 22 has reached a predetermined control switching angle. In other words, the predetermined condition is satisfied when the rotation angle of the crankshaft 22 reaches the predetermined control switching angle after detection of the rotation angle of the crankshaft 22 begins. The predetermined angle is experimentally determined in advance as the rotation angle of the crankshaft 22 at which the throttle opening sensor 46 can be considered to have reached a steady voltage at which it operates steadily, and is stored in the ROM 66.

[0046] ECU14 starts and start counter C START It has been found that there is a correlation between the time from when the ECU 14 starts counting until the voltage applied to the ECU 14 reaches a steady voltage, and the time from when the ECU 14 starts detecting the rotation angle of the crankshaft 22 until the rotation angle of the crankshaft 22 reaches a predetermined control switching angle. Therefore, even in this modified example, the throttle closing value V CLS can be updated to the appropriate value. In another modification, the fuel injection control system 10 may have a backup battery that is used only to start the internal combustion engine. The backup battery is, for example, a battery that is used only to rotate the starter motor. By having such a backup battery, even if the main battery runs out of power, the internal combustion engine can be properly started using the backup battery. In another modification, a reference voltage source may be provided inside or outside the ECU 14, and the power supply voltage may be compared with the voltage of the reference voltage source. The reference voltage source may be formed of a constant voltage element such as a Zener diode or a shunt regulator. In this modification, the predetermined condition is satisfied when the power supply voltage exceeds the voltage of the reference voltage source. [Explanation of symbols]

[0047] 10 fuel injection control system, 12 engine, 14 ECU, 16 cylinder, 18 piston, 20 connecting rod, 22 crankshaft, 26 cylinder chamber, 28 combustion chamber, 30 intake port, 32 exhaust port, 34 intake valve, 36 exhaust valve, 38 throttle valve, 40 spark plug, 42 ignition coil, 44 fuel injection valve, 46 throttle opening sensor, 48 intake pressure sensor, 50 pulser, 60 processing unit, 62 storage device

Claims

1. a control unit configured to supply electric power generated by operation of the internal combustion engine without using a battery; when the electric power generated by the operation of the internal combustion engine is supplied without passing through a battery, after the control unit is started up, until a predetermined condition is satisfied, even if the detected value of the throttle opening sensor is not the minimum value after the control unit is started up, the control unit sets the detected value to a throttle closing value indicating that the throttle valve is closed; The predetermined condition is: A throttle opening detection device characterized in that after the control unit is started, the voltage applied to the throttle opening sensor satisfies a condition that can be considered to have reached a steady-state voltage at which the throttle opening sensor operates steadily.

2. 2. The throttle opening detection device according to claim 1, wherein the predetermined condition is that a predetermined time has elapsed after activation of the control unit.

3. 3. The throttle opening detection device according to claim 1, wherein the control unit avoids setting the detection value of the throttle opening sensor as the throttle closing value when the detection value of the throttle opening sensor exceeds a predetermined upper limit value.

4. 4. The throttle opening detection device according to claim 3, wherein the control unit sets the throttle closing value to the predetermined upper limit value when the detected value of the throttle opening sensor exceeds the predetermined upper limit value.

5. 5. The throttle opening detection device according to claim 1, wherein after the predetermined condition is satisfied, the control unit sets the throttle closing value to a minimum value of the detection value of the throttle opening sensor after startup of the control unit.

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