Internal combustion engine control device and internal combustion engine control method

Abstract

An internal combustion engine control device (12) comprises: a control unit (56) that controls an opening degree (θt) of a throttle valve (40a) on the basis of an operation amount (θg) of an operation member (50); and a limitation processing unit (58) that enables or disables limitation processing for limiting the opening degree to a predetermined upper-limit opening degree (θtu) or less. The control unit executes drivability improvement processing that sets the opening degree corresponding to an operation amount when the limitation processing is enabled to be smaller than the opening degree corresponding to an operation amount when the limitation processing is disabled.

Description

Internal Combustion Engine Control Device and Internal Combustion Engine Control Method

[0001] The present disclosure relates to an internal combustion engine control device and an internal combustion engine control method.

[0002] Japanese Patent Application Laid-Open No. 2000-54888 discloses an intake control device for an engine. In this intake control device, a target throttle valve opening is calculated based on an accelerator operation amount signal, and the calculated target throttle valve opening is compared with a predetermined opening. When the target throttle valve opening is greater than or equal to the predetermined opening, the predetermined opening is output as a throttle valve opening command.

[0003] Techniques for improving the drivability of a vehicle are desired.

[0004] The present disclosure aims to solve the above-described problems.

[0005] A first aspect of the present disclosure is an internal combustion engine control device including: a control unit that controls an opening of a throttle valve of an internal combustion engine based on an operation amount of an operation member provided in a vehicle; and a limit processing unit that enables or disables a limit processing for limiting the opening of the throttle valve to be less than or equal to a predetermined upper limit opening. The control unit executes a drivability improvement process for making the opening corresponding to the operation amount of the operation member when the limit processing unit enables the limit processing smaller than the opening corresponding to the operation amount of the operation member when the limit processing unit disables the limit processing.

[0006] A second aspect of the present disclosure is an internal combustion engine control method including: a first step of enabling or disabling a limit processing for limiting an opening of a throttle valve of an internal combustion engine provided in a vehicle to be less than or equal to a predetermined upper limit opening; and a second step of controlling the opening of the throttle valve based on an operation amount of an operation member provided in the vehicle. In the second step, a drivability improvement process is executed for making the opening corresponding to the operation amount of the operation member when the limit processing is enabled smaller than the opening corresponding to the operation amount of the operation member when the limit processing is disabled.

[0007] According to the present disclosure, the drivability of a vehicle can be improved.

[0008] Figure 1 is a schematic diagram of an internal combustion engine and an internal combustion engine control device according to one embodiment. Figure 2 is a diagram showing the time change between the throttle valve opening and vehicle speed in relation to the amount of operation of the operating member in a comparative example. Figure 3 is a diagram showing the relationship between the rotational speed of the internal combustion engine and the upper limit of the throttle valve opening. Figure 4A is a diagram showing the relationship between the amount of operation of the operating member and the throttle valve opening in a comparative example, and Figure 4B is a diagram showing the relationship between the amount of operation of the operating member and the throttle valve opening in one embodiment. Figure 5 is a diagram showing the time change between the throttle valve opening and vehicle speed in relation to the amount of operation of the operating member in one embodiment. Figure 6 is a diagram showing the relationship between the amount of operation of the operating member and the throttle valve opening. Figure 7 is a flowchart showing the operation of the control unit and the limiting unit (internal combustion engine control method).

[0009] To prevent the vehicle from running rich, a limiting process may be implemented that restricts the throttle valve opening to below a predetermined upper limit. If this limiting process is simply implemented, the engine's output will stop increasing before the throttle valve operation reaches its maximum. This may cause discomfort to the driver.

[0010] According to this disclosure, it is possible to provide an internal combustion engine control device and an internal combustion engine control method that can reduce driver discomfort and improve the drivability of a vehicle.

[0011] Figure 1 is a schematic diagram of an internal combustion engine 10 and an internal combustion engine control device 12 according to one embodiment. The internal combustion engine 10 and the internal combustion engine control device 12 are installed in a vehicle 14. The vehicle 14 is, for example, a motorcycle 16 such as a scooter, but is not limited to this. The vehicle 14 may be various types of vehicles, including motorcycles.

[0012] The internal combustion engine 10 is a single-cylinder engine. The internal combustion engine 10 comprises a cylinder 18 and a cylinder head 20. A piston 22 is provided inside the cylinder 18. The piston 22 is connected to the crankshaft 26 via a connecting rod 24. A combustion chamber 28 is formed between the piston 22 inside the cylinder 18 and the cylinder head 20. An intake port 30 and an exhaust port 32 are formed in the cylinder head 20. The intake port 30 and the exhaust port 32 communicate with the combustion chamber 28.

[0013] The internal combustion engine 10 is further equipped with an intake pipe 34 and an exhaust pipe 38. The intake pipe 34 is connected to an intake port 30. An intake valve 36 is provided in the intake port 30. The exhaust pipe 38 is connected to an exhaust port 32. An exhaust valve 39 is provided in the exhaust port 32.

[0014] The internal combustion engine 10 is further equipped with an electronically controlled throttle 40. The electronically controlled throttle 40 is located in the intake manifold 34. The electronically controlled throttle 40 includes a throttle valve 40a, a throttle drive unit 40b, and a throttle position sensor 40c.

[0015] The throttle valve 40a is located inside the intake manifold 34. The throttle valve 40a is a butterfly valve. The throttle drive unit 40b drives the throttle valve 40a to open and close it. The opening and closing of the throttle valve 40a adjusts the amount of air supplied to the intake port 30 (intake volume). The throttle position sensor 40c detects the opening degree θt of the throttle valve 40a.

[0016] A fuel injector 42 is provided in the intake port 30. The fuel injector 42 is located between the intake valve 36 and the intake pipe 34. The fuel injector 42 has a fuel injector valve 42a. The fuel injector valve 42a injects fuel into the intake port 30. When fuel is injected, a mixture of fuel and air is created. When the intake valve 36 is open, the mixture flows into the combustion chamber 28.

[0017] The fuel used in the internal combustion engine 10 is, for example, gasoline. The fuel used in the internal combustion engine 10 may also be diesel fuel, biomass ethanol, liquefied petroleum gas, etc.

[0018] If the internal combustion engine 10 is a direct fuel injection engine, the fuel injection device 42 may be provided in the cylinder head 20. In this case, the fuel injection valve 42a directly injects fuel into the combustion chamber 28.

[0019] An ignition device 44 is provided in the cylinder head 20. The ignition device 44 has a spark plug 44a and an ignition coil 44b. The ignition coil 44b boosts the voltage supplied from a battery (not shown). The spark plug 44a discharges due to the boosted voltage, igniting the air-fuel mixture flowing into the combustion chamber 28. The explosion of the ignited air-fuel mixture causes the piston 22 to reciprocate along the axial direction of the cylinder 18.

[0020] The connecting rod 24 converts the reciprocating motion of the piston 22 into rotational motion of the crankshaft 26, thereby rotating the crankshaft 26. Based on the rotation of the crankshaft 26, the wheels (not shown) of the vehicle 14 rotate, causing the vehicle 14 to move. When the exhaust valve 39 is open, the exhaust gas generated by the explosion of the fuel-air mixture is discharged to the outside of the vehicle 14 through the exhaust pipe 38.

[0021] A signal rotor 46 is coaxially connected to the crankshaft 26. Multiple protrusions 46a are provided on the outer circumferential surface of the signal rotor 46 at intervals in the circumferential direction. The vehicle 14 is further equipped with a crank angle sensor 48. The crank angle sensor 48 detects the rotation angle of the crankshaft 26 by detecting the protrusions 46a of the signal rotor 46 when the signal rotor 46 rotates together with the crankshaft 26.

[0022] Vehicle 14 further includes an operating member 50, an accelerator sensor 52, and a vehicle speed sensor 54. The operating member 50 is, for example, a throttle grip on the handlebars of a motorcycle 16. The operating member 50 can be operated by the driver of vehicle 14. The accelerator sensor 52 detects the amount of operation θg of the operating member 50 when the driver operates the operating member 50. The accelerator sensor 52 detects the current position of the operating member 50 relative to its initial position (origin position) (for example, the rotation angle of the throttle grip) as the amount of operation θg of the operating member 50. Alternatively, the accelerator sensor 52 detects the amount of change of the operating member 50 due to the driver's operation (for example, the amount of rotation of the throttle grip) as the amount of operation θg of the operating member 50. The vehicle speed sensor 54 detects the vehicle speed V of vehicle 14.

[0023] The detection results from the crank angle sensor 48, the throttle position sensor 40c, the accelerator sensor 52, and the vehicle speed sensor 54 are output to the internal combustion engine control device 12.

[0024] The internal combustion engine control device 12 comprises a calculation unit 12a, a storage unit 12b, and a drive circuit 12c. The calculation unit 12a is, for example, a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The calculation unit 12a has a control unit 56 and a limiting processing unit 58. The control unit 56 and the limiting processing unit 58 are realized by the execution of a program stored in the storage unit 12b in the calculation unit 12a. At least a part of the control unit 56 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). At least a part of the control unit 56 may be realized by an electronic circuit including discrete devices.

[0025] The storage unit 12b is a computer-readable storage medium. The storage unit 12b is composed of a volatile memory (not shown) and a non-volatile memory (not shown). The volatile memory is, for example, RAM (Random Access Memory). The non-volatile memory is, for example, ROM (Read Only Memory), flash memory, etc. Data is stored in the volatile memory, for example. Programs, tables, maps, etc. are stored in the non-volatile memory, for example. At least a part of the storage unit 12b may be provided in the processor, integrated circuit, etc. mentioned above.

[0026] The limiting processing unit 58 can perform a limiting process to restrict the opening degree θt of the throttle valve 40a to less than or equal to a predetermined upper limit opening degree θtu. The limiting processing unit 58 can enable or disable this limiting process. The control unit 56 controls the opening degree θt of the throttle valve 40a based on the operation amount θg input from the accelerator sensor 52. Specifically, the control unit 56 outputs a control command to the drive circuit 12c that includes the opening degree θt corresponding to the operation amount θg of the operating member 50.

[0027] Furthermore, the control unit 56 may perform drivability improvement processing (drivability improvement mode, discomfort reduction processing). Drivability improvement processing is a process that makes the opening degree θt corresponding to the manipulated amount θg when the limiting processing is set to enabled smaller than the opening degree θt corresponding to the manipulated amount θg when the limiting processing is set to disabled. When performing drivability improvement processing, the control unit 56 outputs a control command including the reduced opening degree θt to the drive circuit 12c.

[0028] The drive circuit 12c drives the throttle drive unit 40b based on control commands from the control unit 56. Details of the limiting process and the drivability improvement process will be described later.

[0029] Furthermore, the control unit 56 calculates the rotational speed N of the internal combustion engine 10 based on the crank angle input from the crank angle sensor 48. The control unit 56 determines the upper limit opening θtu according to the calculated rotational speed N. In addition, the control unit 56 controls the ignition of the ignition device 44 and the supply of fuel by the fuel injection device 42.

[0030] Figure 2 shows the time variation of the opening degree θt of the throttle valve 40a and the vehicle speed V with respect to the operating amount θg of the operating member 50 (see Figure 1) in the comparative example. In the comparative example, the limiting process can be performed, but the drivability improvement process is not performed.

[0031] When the driver starts operating the operating member 50 at time t0, the amount of operation θg of the operating member 50 increases over time. The control unit 56 determines the opening degree θt of the throttle valve 40a based on the amount of operation θg of the operating member 50. As a result, the opening degree θt of the throttle valve 40a (see Figure 1) increases over time, as shown by the dashed line in Figure 2. As the opening degree θt of the throttle valve 40a increases, the amount of air (intake volume) drawn into the combustion chamber 28 increases. Along with the increase in intake volume, the amount of fuel (fuel volume) supplied to the combustion chamber 28 also increases. As both intake volume and fuel volume increase, the output of the internal combustion engine 10 increases, and the vehicle speed V rises over time. Note that in Figure 2, the units of the operating amount θg and the opening degree θt are both in degrees [°].

[0032] At time t1, when the opening degree θt of the throttle valve 40a (see Figure 1) reaches the upper limit opening degree θtu, the filling efficiency η of the air drawn into the combustion chamber 28 reaches 100%. That is, the upper limit opening degree θtu is the opening degree θt of the throttle valve 40a when the filling efficiency η is 100%. The filling efficiency η is the ratio of the amount of intake air Ai drawn into the combustion chamber 28 to the amount of exhaust gas Ao discharged from the combustion chamber 28 (η = Ai / Ao). When η = 100%, as shown by the dashed line in Figure 2, even if the operating amount θg of the operating member 50 (see Figure 1) is increased to increase the opening degree θt of the throttle valve 40a, the amount of intake air drawn into the combustion chamber 28 does not increase, and the amount of fuel supplied to the combustion chamber 28 increases. When the opening degree θt of the throttle valve 40a becomes larger than the upper limit opening degree θtu, the output of the internal combustion engine 10 does not increase. As a result, vehicle 14 enters a rich-fuel driving state, and the fuel efficiency of vehicle 14 decreases.

[0033] Figure 3 shows the relationship between the rotational speed N of the internal combustion engine 10 (see Figure 1) and the upper limit of throttle opening θtu. The upper limit of throttle opening θtu is determined according to the rotational speed N of the internal combustion engine 10. In the region where the rotational speed N is relatively low, the upper limit of throttle opening θtu increases with increasing rotational speed N. In the region where the rotational speed N is relatively high, the upper limit of throttle opening θtu does not change with increasing rotational speed N. In Figure 3, in the region where the opening θt of the throttle valve 40a (see Figure 1) is greater than the upper limit of throttle opening θtu, η = 100%, and the vehicle 14 operates in rich mode. Furthermore, the relationship between rotational speed N and upper limit of throttle opening θtu shown in Figure 3 is stored as a table or map in the storage unit 12b (see Figure 1).

[0034] As shown in Figure 2, in the comparative example, when the opening degree θt of the throttle valve 40a (see Figure 1) reaches the upper limit opening degree θtu at time t1, a limiting process is activated that restricts the opening degree θt to the upper limit opening degree θtu or less. When the limiting process is activated, even if the driver of the vehicle 14 increases the amount θg of the operating member 50 after time t1, the opening degree θt of the throttle valve 40a is restricted to the upper limit opening degree θtu or less. In Figure 2, as shown by the dashed line, after time t1, the opening degree θt of the throttle valve 40a is maintained at the upper limit opening degree θtu in response to an increase in the amount θg of the operating member 50. As a result, the output of the internal combustion engine 10 is limited, and the vehicle speed V is maintained at a constant speed over time.

[0035] Thus, by enabling the limiting process, the opening degree θt of the throttle valve 40a does not exceed the upper limit opening degree θtu, so the vehicle 14 does not run rich, and fuel efficiency improves. However, the driver feels something is off because even if they increase the amount θg of the operating member 50 to accelerate the vehicle 14, the vehicle speed V does not increase.

[0036] More specifically, as shown in Figure 4A, if the operating member 50 (see Figure 1) is a throttle grip, the driver can rotate the throttle grip from the initial position (origin) of 0° to the maximum position of θgmax. When the limiting process is enabled, the opening degree θt of the throttle valve 40a is limited to a range from the initial position (origin) of 0° to the upper limit opening degree θtu. Therefore, even if the driver increases the amount θg of the throttle grip operation when the opening degree θt of the throttle valve 40a has reached the upper limit opening degree θtu, the opening degree θt will not exceed the upper limit opening degree θtu.

[0037] In this embodiment, a drivability improvement process can be performed to improve the drivability of the vehicle 14.

[0038] Figure 4B shows the relationship between the operating amount θg of the operating member 50 (see Figure 1) and the opening degree θt of the throttle valve 40a in this embodiment. Note that in Figure 4A and Figures 5 and 6 described later, the operating amount θg of the operating member 50 is expressed as a percentage with the maximum operating amount θgmax, which is the maximum value of the operating amount θg, set to 100%. Also, the opening degree θt of the throttle valve 40a is expressed as a percentage with the upper limit opening degree θtu set to 100%.

[0039] In the drivability improvement process, as shown in Figure 4B, the upper limit opening degree θtu is made to correspond to the maximum operating amount θgmax of the operating member 50 (see Figure 1). That is, the maximum opening degree θtmax, which is the opening degree θt corresponding to the maximum operating amount θgmax of the operating member 50, is set to the upper limit opening degree θtu. As a result, when the driver operates the operating member 50 to the maximum operating amount θgmax, the throttle valve 40a reaches the upper limit opening degree θtu, thus reducing the driver's discomfort. Note that in the drivability improvement process, the maximum opening degree θtmax is not limited to the upper limit opening degree θtu.

[0040] Figure 5 shows the time change between the opening degree θt of the throttle valve 40a and the vehicle speed V with respect to the operating amount θg of the operating member 50 (see Figure 1) in this embodiment. In Figure 5, the dashed line shows a comparative example (see Figure 2).

[0041] As shown in FIG. 5, in the present embodiment, the opening degree θt of the throttle valve 40a (see FIG. 1) increases more gently over time than in the comparative example shown by the dashed line. As a result, the output of the internal combustion engine 10 in the present embodiment increases more gently than the output of the internal combustion engine 10 in the comparative example. As a result, in the present embodiment, the vehicle speed V gently increases over time. When the operation amount θg of the operation member 50 reaches the maximum operation amount θgmax at time t2, the opening degree θt of the throttle valve 40a reaches the upper limit opening degree θtu. The driver can feel that the vehicle speed V is gently increasing in response to the operation of the operation member 50. Thus, by executing the driving performance improvement process, the discomfort of the driver is reduced.

[0042] FIG. 6 is a diagram showing the relationship between the operation amount θg of the operation member 50 and the opening degree θt of the throttle valve 40a. The relationship between the operation amount θg and the opening degree θt shown in FIG. 6 is stored in the storage unit 12b (see FIG. 1) as a table or a map.

[0043] La indicates a case where the driving performance improvement process is not executed. Lb, Lc, and Ld indicate cases where the driving performance improvement process is executed.

[0044] In Lb, when the driver operates the operation member 50 to the maximum operation amount θgmax, the opening degree θt of the throttle valve 40a reaches the upper limit opening degree θtu (maximum opening degree θtmax). In Lb, the discomfort of the driver can be reduced well. In Lc, before the operation amount θg of the operation member 50 reaches the maximum operation amount θgmax, the opening degree θt of the throttle valve 40a reaches the upper limit opening degree θtu. Even in Lc, it is possible to reduce the discomfort of the driver to some extent. In Ld, even when the operation amount θg of the operation member 50 reaches the maximum operation amount θgmax, the opening degree θt of the throttle valve 40a does not reach the upper limit opening degree θtu. Even in Ld, it is possible to reduce the discomfort of the driver to some extent.

[0045] In La, in order to prioritize the driver's intention to accelerate, when the operation amount θg of the operation member 50 reaches the maximum operation amount θgmax, the opening degree θt of the throttle valve 40a reaches 100%.

[0046] FIG. 7 is a flowchart showing the operations of the control unit 56 and the restriction processing unit 58 (internal combustion engine control method).

[0047] In step S1 (first step), the restriction processing unit 58 (see FIG. 1) determines whether the increase amount Δθg of the operation amount θg of the operation member 50 per unit time is less than a predetermined value Δθgth.

[0048] When Δθg < Δθgth (step S1: YES), the restriction processing unit 58 proceeds to step S2 (first step). In step S2, the restriction processing unit 58 enables the restriction processing. In the next step S3 (second step), the control unit 56 executes an operation performance improvement process. In the operation performance improvement process, the control unit 56 refers to the map stored in the storage unit 12b and sets an upper limit opening θtu corresponding to the rotational speed N (see FIG. 3) and sets an opening θt corresponding to the operation amount θg (see FIG. 6). Therefore, in step S3, the control unit 56 sets the opening θt of the throttle valve 40a corresponding to the operation amount θg of the operation member 50 according to Lb, Lc, or Ld shown in FIG. 6.

[0049] In step S1, when Δθg ≧ Δθgth (step S1: NO), the restriction processing unit 58 proceeds to step S4 (first step). In step S4, the restriction processing unit 58 disables the restriction processing. In the next step S5 (second step), the control unit 56 cancels the operation performance improvement process. In this case, the control unit 56 refers to the map stored in the storage unit 12b and sets an opening θt corresponding to the operation amount θg (see FIG. 6). Therefore, in step S5, the control unit 56 sets the opening θt of the throttle valve 40a corresponding to the operation amount θg of the operation member 50 according to La shown in FIG. 6.

[0050] Note that in the present embodiment, the internal combustion engine 10 is not limited to a single-cylinder engine. The internal combustion engine 10 may be a multi-cylinder engine with a relatively small displacement. Further, the operation member 50 is not limited to a throttle grip. The operation member 50 may be an accelerator pedal. <<ID=14>>

[0051] Regarding the above embodiment, the following additional remarks are disclosed.

[0052] (Note 1) An internal combustion engine control device (12) in a first aspect of the present disclosure includes a control unit (56) that controls the opening degree (θt) of a throttle valve (40a) of an internal combustion engine (10) based on an operating amount (θg) of an operating member (50) provided on a vehicle (14), and a restriction processing unit (58) that enables or disables a restriction processing that limits the opening degree of the throttle valve to a predetermined upper limit opening degree (θtu) or less, wherein the control unit performs a drivability improvement processing that makes the opening degree corresponding to the operating amount of the operating member when the restriction processing unit has enabled the restriction processing smaller than the opening degree corresponding to the operating amount when the restriction processing unit has disabled the restriction processing.

[0053] This configuration can reduce driver discomfort and improve the vehicle's drivability. Specifically, it avoids a situation where increasing the throttle valve opening does not increase the output of the internal combustion engine. As a result, it avoids a situation where the vehicle speed does not change in response to changes in the amount of operation of the control member.

[0054] (Note 2) In the internal combustion engine control device described in Note 1, the control unit may, when the limiting processing unit has enabled the limiting process, set the maximum opening degree (θtmax), which is the opening degree corresponding to the maximum operating amount (θgmax), which is the maximum value of the operating amount of the operating member, to be less than or equal to the upper limit opening degree.

[0055] This effectively improves the vehicle's drivability.

[0056] (Note 3) In the internal combustion engine control device described in Note 2, the maximum opening degree may be the upper limit opening degree.

[0057] This ensures that when the driver operates the control element to its maximum extent, the throttle valve opening reaches its upper limit, further improving the vehicle's drivability.

[0058] (Note 4) In the internal combustion engine control device described in any one of Notes 1 to 3, the limiting processing unit may disable the limiting processing when the increase per unit time (Δθg) of the amount of operation of the operating member is equal to or greater than a predetermined value (Δθgth).

[0059] This allows the throttle valve opening degree to be set according to the amount of operation of the control member, prioritizing the driver's intention to accelerate.

[0060] (Note 5) In the internal combustion engine control device described in any one of Notes 1 to 4, the control unit may release the drivability improvement process when the amount of the operation of the operating member increases per unit time by a predetermined value or more.

[0061] This allows the throttle valve opening degree to be set according to the amount of operation of the control member, prioritizing the driver's intention to accelerate.

[0062] (Note 6) In the internal combustion engine control device described in any one of Notes 1 to 5, the upper limit opening degree may be determined according to the rotational speed (N) of the internal combustion engine.

[0063] (Note 7) In the internal combustion engine control device described in any one of Notes 1 to 6, the internal combustion engine may be a single-cylinder internal combustion engine.

[0064] Single-cylinder internal combustion engines have lower output compared to multi-cylinder internal combustion engines. Therefore, when the limiting mechanism is disabled, the throttle valve opening is likely to reach its upper limit before the amount of operation of the operating member reaches its maximum. For vehicles equipped with single-cylinder internal combustion engines, enabling the limiting mechanism and performing drivability improvement processing can effectively improve the vehicle's drivability.

[0065] (Note 8) In the internal combustion engine control device described in any one of Notes 1 to 7, the vehicle may be a motorcycle (16).

[0066] Motorcycles have smaller internal combustion engine outputs compared to relatively large motorcycles. Therefore, when the limiting mechanism is disabled, the throttle valve opening is likely to reach its upper limit before the amount of operation of the control member reaches its maximum. For motorcycles, enabling the limiting mechanism and simultaneously performing drivability improvement processing can effectively improve the drivability of the motorcycle.

[0067] (Note 9) A second embodiment of the internal combustion engine control method of the present disclosure includes a first step (S1, S2, S4) of enabling or disabling a limiting process that limits the opening degree of a throttle valve of an internal combustion engine provided in a vehicle to a predetermined upper limit opening degree or less, and a second step (S3, S5) of controlling the opening degree of the throttle valve based on the amount of operation of an operating member provided in the vehicle, wherein the second step is to perform a drivability improvement process that makes the opening degree corresponding to the amount of operation of the operating member when the limiting process is enabled smaller than the opening degree corresponding to the amount of operation when the limiting process is disabled.

[0068] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the intent of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

[0069] 10...Internal combustion engine 12...Internal combustion engine control device 14...Vehicle 16...Motorcycle 40a...Throttle valve 50...Operating member 56...Control unit 58...Restriction processing unit

Claims

1. An internal combustion engine control device (12) comprising: a control unit (56) that controls the opening degree (θt) of a throttle valve (40a) of an internal combustion engine (10) based on the amount of operation (θg) of an operating member (50) provided on a vehicle (14); and a restriction processing unit (58) that enables or disables a restriction processing that limits the opening degree of the throttle valve to a predetermined upper limit opening degree (θtu) or less, wherein the control unit executes a drivability improvement processing that makes the opening degree corresponding to the amount of operation of the operating member when the restriction processing unit has enabled the restriction processing smaller than the opening degree corresponding to the amount of operation when the restriction processing unit has disabled the restriction processing.

2. An internal combustion engine control device according to claim 1, wherein the control unit, when the limiting processing unit has enabled the limiting process, sets the maximum opening degree (θtmax), which is the opening degree corresponding to the maximum operating amount (θgmax), which is the maximum value of the operating amount of the operating member, to be less than or equal to the upper limit opening degree.

3. An internal combustion engine control device according to claim 2, wherein the maximum opening degree is the upper limit opening degree.

4. An internal combustion engine control device according to any one of claims 1 to 3, wherein the limiting processing unit disables the limiting processing when the increase per unit time (Δθg) of the operating amount of the operating member is equal to or greater than a predetermined value (Δθgth).

5. An internal combustion engine control device according to any one of claims 1 to 3, wherein the control unit releases the drivability improvement process when the amount of the operation of the operating member increases per unit time by a predetermined value or more.

6. An internal combustion engine control device according to any one of claims 1 to 3, wherein the upper limit opening is determined according to the rotational speed (N) of the internal combustion engine.

7. An internal combustion engine control device according to any one of claims 1 to 3, wherein the internal combustion engine is a single-cylinder internal combustion engine.

8. An internal combustion engine control device according to any one of claims 1 to 3, wherein the vehicle is a motorcycle (16).

9. An internal combustion engine control method comprising: a first step (S1, S2, S4) of enabling or disabling a limiting process that restricts the opening degree of a throttle valve of an internal combustion engine provided in a vehicle to a predetermined upper limit opening degree; and a second step (S3, S5) of controlling the opening degree of the throttle valve based on the amount of operation of an operating member provided in the vehicle, wherein in the second step, a drivability improvement process is performed to make the opening degree corresponding to the amount of operation of the operating member when the limiting process is enabled smaller than the opening degree corresponding to the amount of operation when the limiting process is disabled.

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