Internal combustion engine control device

Abstract

To provide an internal combustion engine control device which enables low fuel consumption.SOLUTION: An internal combustion engine control device 100 derives a torque TQRLLINE associated with a detected rotation speed NE in a first table that associates a rotation speed NE of the internal combustion engine 1 with the torque TQRLLINE for a steady operation state; derives a correction value MTQPACT associated with the detected rotation speed NE in a second table that associates the rotation speed NE with the correction value MTQPACT; derives an acceptable torque TQTRGPACT by correcting the torque TQRLLINE derived from the first table with the correction value MTQPACT derived from the second table; and derives an upper limit value THLIM on an opening of a throttle valve 14 of the internal combustion engine 1 based on the derived acceptable torque TQTRGPACT and the detected rotation speed NE.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, there is known an internal combustion engine control device that controls the amount of fuel supplied depending on the operating state of the internal combustion engine. Patent Document 1 discloses an internal combustion engine control device that increases the amount of fuel supplied depending on the change in the throttle opening when the throttle opening exceeds a predetermined value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2-201048 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, there is a problem that fuel efficiency decreases when the fuel supply amount is increased more frequently than necessary in response to changes in the throttle opening.

[0005] The present invention has been made in light of the above considerations, and an object of the present invention is to provide an internal combustion engine control device that can achieve low fuel consumption. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one aspect of the present invention is an internal combustion engine control device that derives an upper limit value of the opening degree of a throttle valve of an internal combustion engine based on the rotational speed of the internal combustion engine, the control device having: a memory unit that stores a first table that corresponds the rotational speed with the torque in a steady operating state of the internal combustion engine, and a second table that corresponds the rotational speed with a correction value for correcting the torque; and a control unit that derives the torque corresponding to the rotational speed detected in the first table, derives the correction value corresponding to the rotational speed detected in the second table, corrects the torque derived from the first table with the correction value derived from the second table to derive an allowable torque, and derives the upper limit value based on the derived allowable torque and the detected rotational speed. [Effects of the Invention]

[0007] According to one aspect of the present invention, there is provided an internal combustion engine control device that derives an upper limit value for the opening degree of a throttle valve of an internal combustion engine based on the rotational speed of the internal combustion engine, and includes a memory unit that stores a first table that corresponds the rotational speed with the torque in the steady operating state of the internal combustion engine, and a second table that corresponds the rotational speed with a correction value for correcting the torque, and a control unit that derives the torque corresponding to the rotational speed detected in the first table, derives the correction value corresponding to the rotational speed detected in the second table, corrects the torque derived from the first table with the correction value derived from the second table, derives the allowable torque, and derives an upper limit value based on the derived allowable torque and the detected rotational speed, thereby achieving low fuel consumption. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of an internal combustion engine control device according to an embodiment of the present invention. [Figure 2]FIG. 2 is a diagram showing an example of a table correlating rotation speeds with torque in a steady operating state and a table correlating rotation speeds with correction values, both of which are stored in the internal combustion engine control device according to the embodiment of the present invention. [Figure 3] FIG. 3 is a diagram showing an upper limit value derivation table stored in the internal combustion engine control device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a timing chart showing the operation of the internal combustion engine control device according to the embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing a high load operating region of an internal combustion engine controlled by an internal combustion engine control device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] 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.

[0010] <Configuration of an internal combustion engine> The configuration of an internal combustion engine 1 according to an embodiment of the present invention will be described in detail with reference to FIG.

[0011] The internal combustion engine 1 to which the internal combustion engine control device 100 of this embodiment is applied is an engine mounted on a vehicle such as a motorcycle (not shown), and includes a cylinder block 2 for each cylinder 2a.

[0012] A piston 4 is disposed inside the cylinder 2a. 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 are formed on the outer circumferential surface of the reluctor 7 along the circumferential direction.

[0013] 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 a combustion chamber 9 of the cylinder 2a.

[0014] The cylinder head 8 is provided with a spark plug 10 that ignites a mixture of fuel and air in the combustion chamber 9 under the control of the internal combustion engine control device 100. Note that the number of spark plugs 10 that ignite the mixture in the combustion chamber 9 may be multiple.

[0015] An intake pipe 11 communicating with the combustion chamber 9 is provided in the cylinder head 8. An intake passage 11a communicating between the combustion chamber 9 and the intake pipe 11 is formed inside the cylinder head 8. An intake valve 12 is provided at the connection between the combustion chamber 9 and the intake passage 11a. The number of intake pipes 11 and intake passages 11a is equal to the number of cylinders 2a.

[0016] A throttle valve 14 is provided inside the intake pipe 11. The throttle valve 14 is a component of a throttle device (not shown) and opens and closes under the control of the internal combustion engine control device 100. A main body of the throttle device is attached to the intake pipe 11. An injector 107 that injects fuel is provided inside the intake pipe 11 downstream of the throttle valve 14 in the intake direction of the intake air.

[0017] Additionally, the cylinder head 8 is provided with an exhaust pipe 15 that communicates with the combustion chamber 9. An exhaust passage 15a that communicates the combustion chamber 9 with the exhaust passage 15a is formed inside the cylinder head 8. An exhaust valve 16 is provided at the connection between the combustion chamber 9 and the exhaust pipe 15. The number of exhaust pipes 15 and exhaust passages 15a is equal to the number of cylinders 2a.

[0018] The internal combustion engine temperature sensor 101 outputs an electric signal corresponding to the temperature of the internal combustion engine 1 to the internal combustion engine control device 100 .

[0019] The crank angle sensor 102 is mounted on a lower case (not shown) or the like assembled to the lower part of the cylinder block 2, facing the teeth 7a formed on the outer peripheral surface of the reluctor 7. The crank angle sensor 102 detects the teeth 7a that rotate in conjunction with the rotation of the crankshaft 6, thereby detecting the rotation speed of the crankshaft 6 as the rotation speed (number of revolutions) of the internal combustion engine 1, and outputs an electric signal according to the detection result of the rotation speed to the internal combustion engine control device 100.

[0020] The intake pressure sensor 103 outputs to the internal combustion engine control device 100 an electric signal corresponding to the pressure (intake pressure) of the air flowing into the intake pipe 11 on the downstream side of the throttle valve 14 .

[0021] The throttle opening sensor 104 is attached to the main body of the throttle device, detects the opening of the throttle valve 14, and outputs an electric signal according to the detection result of the opening of the throttle valve 14 to the internal combustion engine control device 100.

[0022] The accelerator opening sensor 105 outputs an electric signal to the internal combustion engine control device 100 according to the amount of operation of an accelerator operating member (not shown) of the vehicle.

[0023] The vehicle speed sensor 106 outputs an electric signal to the internal combustion engine control device 100 according to the vehicle speed of the vehicle on which the internal combustion engine 1 is mounted.

[0024] An injector 107 is provided for each cylinder 2a. The injector 107 includes a coil (not shown), and when the coil is energized under the control of the internal combustion engine control device 100, the injector 107 opens a valve to inject and supply fuel to the internal combustion engine 1.

[0025] The catalyst 109 is provided midway through the exhaust pipe 15, and purifies the exhaust gas discharged from the combustion chamber 9. The catalyst 109 is exemplified here as a three-way catalyst.

[0026] The O2 sensor 110 communicates with the exhaust pipe 15 upstream of the catalyst 109 in the exhaust direction of the exhaust gas, and is disposed close to the catalyst 109. The O2 sensor 110 detects the oxygen concentration in the exhaust gas upstream of the catalyst 109, and outputs an electrical signal corresponding to the detected oxygen concentration to the internal combustion engine control device 100.

[0027] <Configuration of the internal combustion engine control device> The configuration of an internal combustion engine control device 100 according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG.

[0028] In FIG. 2, FIG. 2(a) is an example of the first table, and FIG. 2(b) is an example of the second table.

[0029] The internal combustion engine control device 100 is applied to a vehicle such as a motorcycle (not shown) to control the operation of the internal combustion engine 1, and is configured by an electronic control device such as an ECU (Electronic Control Unit). The internal combustion engine control device 100 is electrically connected to an internal combustion engine temperature sensor 101, a crank angle sensor 102, an intake pressure sensor 103, a throttle opening sensor 104, an accelerator opening sensor 105, a vehicle speed sensor 106, an injector 107, and an O2 sensor 110.

[0030] The internal combustion engine control device 100 includes a storage unit 50 and a control unit 51.

[0031] The storage unit 50 stores a control program and various tables. The storage unit 50 includes a torque storage unit 111, a correction value storage unit 112, and an upper limit value storage unit 113.

[0032] The torque memory unit 111 stores a first table that associates the rotation speed NE of the internal combustion engine 1 with the torque TQRLLINE in the steady operating state of the internal combustion engine 1. The relationship between the rotation speed NE of the internal combustion engine 1 and the torque TQRLLINE in the steady operating state of the internal combustion engine 1 in the first table stored in the torque memory unit 111 has, for example, the curved relationship shown in Figure 2(a) in which the torque TQRLLINE increases as the rotation speed NE increases. Here, the steady operating state is a state in which the amount of change per unit time of the rotation speed NE of the internal combustion engine 1 remains zero or less than a predetermined value close to zero for a certain period of time or more.

[0033] The correction value storage unit 112 stores a second table that associates the rotation speed of the internal combustion engine 1 with a correction value MTQPACT for correcting the torque TQRLLINE. The relationship between the rotation speed NE of the internal combustion engine 1 and the correction value MTQPACT in the second table stored in the correction value storage unit 112 has the relationship of a curve shown in Figure 2(b), in which the correction value MTQPACT decreases as the rotation speed NE increases.

[0034] The upper limit value storage unit 113 stores an upper limit value derivation table shown in FIG. 3, which associates the rotation speed NE of the internal combustion engine 1, the allowable torque TQTRGPACT, and the upper limit value THLIM.

[0035] The control unit 51 controls the overall operation of the internal combustion engine control device 100 by reading and executing a control program stored in the storage unit 50. The control unit 51 derives an upper limit value THLIM of the opening degree of the throttle valve 14 based on the rotation speed NE of the internal combustion engine 1. The control unit 51 controls the throttle valve 14 so that the opening degree of the throttle valve 14 does not exceed the derived upper limit value THLIM.

[0036] Specifically, the control unit 51 includes a torque derivation unit 114 , a correction value derivation unit 115 , an allowable torque derivation unit 116 , and an upper limit value derivation unit 117 .

[0037] The torque derivation unit 114 derives the torque TQRLLINE, which is associated with the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102, in a first table stored in the torque memory unit 111 of the memory unit 50. The torque derivation unit 114 outputs an electrical signal corresponding to the derived torque TQRLLINE to the allowable torque derivation unit 116.

[0038] The correction value derivation unit 115 derives the correction value MTQPACT, which is associated with the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102, in a second table stored in the correction value storage unit 112 of the storage unit 50. The correction value derivation unit 115 outputs an electrical signal corresponding to the derived correction value MTQPACT to the allowable torque derivation unit 116.

[0039] The allowable torque derivation unit 116 derives the allowable torque TQTRGPACT by correcting the torque TQRLLINE indicated by the electrical signal input from the torque derivation unit 114 with the correction value MTQPACT indicated by the electrical signal input from the correction value derivation unit 115. The allowable torque derivation unit 116 outputs an electrical signal corresponding to the derived allowable torque TQTRGPACT to the upper limit value derivation unit 117.

[0040] The upper limit value derivation unit 117 derives an upper limit value THLIM of the opening of the throttle valve 14 based on the allowable torque TQTRGPACT indicated by the electrical signal input from the allowable torque derivation unit 116 and the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102. Specifically, the upper limit value derivation unit 117 derives the upper limit value THLIM associated with the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102 and the allowable torque TQTRGPACT indicated by the electrical signal input from the allowable torque derivation unit 116, in an upper limit value derivation table stored in the upper limit value storage unit 113. The upper limit value derivation unit 117 controls the driving of the throttle valve 14 so that the opening of the throttle valve 14 does not exceed the derived upper limit value THLIM.

[0041] <Operation of the internal combustion engine control device> The operation of the internal combustion engine control device 100 according to the embodiment of the present invention will be described in detail with reference to FIGS.

[0042] First, at time t1, the driver operates an accelerator operating member (not shown) of the vehicle in the opening direction, and the throttle opening indicated by the electrical signal input from the throttle opening sensor 104 begins to change in the opening direction.

[0043] After time t1, the torque derivation unit 114 of the control unit 51 derives the torque TQRLLINE, which is associated with the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102, in a first table, an example of which is shown in Figure 2(a), which is stored in the torque memory unit 111 of the memory unit 50.

[0044] Next, the correction value derivation unit 115 of the control unit 51 derives the correction value MTQPACT, which is associated with the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102, in a second table, an example of which is shown in Figure 2(b), which is stored in the correction value memory unit 112 of the memory unit 50.

[0045] Next, the allowable torque derivation unit 116 of the control unit 51 corrects the torque TQRLLINE indicated by the electrical signal input from the torque derivation unit 114 with the correction value MTQPACT indicated by the electrical signal input from the correction value derivation unit 115 to derive the allowable torque TQTRGPACT.

[0046] Next, the upper limit value derivation unit 117 of the control unit 51 derives the upper limit value THLIM of the opening of the throttle valve 14 based on the allowable torque TQTRGPACT indicated by the electrical signal input from the allowable torque derivation unit 116 and the rotation speed NE of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102.

[0047] Next, the upper limit value derivation unit 117 controls the driving of the throttle valve 14 so that the opening degree of the throttle valve 14 does not exceed the derived upper limit value THLIM.

[0048] Specifically, at time t3, the torque derivation unit 114 derives the torque TQRLLINE2, the allowable torque derivation unit 116 corrects the torque TQRLLINE2 with the correction value MTQPACT to derive TQTRGPACT22 as the allowable torque, and the upper limit value derivation unit 117 obtains NE2 as the rotation speed of the internal combustion engine 1 indicated by the electrical signal input from the crank angle sensor 102, and derives THLIM2 as the upper limit value associated with the rotation speed NE2 and the allowable torque TQTRGPACT22 in the upper limit value derivation table shown in Figure 3.

[0049] Then, at time t4, the opening of the throttle valve 14 reaches the full opening.

[0050] In this way, if the control unit 51 does not perform the above operation after time t1, the opening of the throttle valve 14 changes rapidly in the opening direction and reaches the fully open position at time t2. On the other hand, if the control unit 51 repeats the above operation, the opening of the throttle valve 14 changes gradually in the opening direction, and therefore does not reach the fully open position at time t2 but reaches the fully open position at time t4.

[0051] Here, when the rotation speed NE is low and the driver suddenly operates the accelerator pedal of the vehicle in the opening direction, the internal combustion engine 1 enters a high-load operating state (see FIG. 5). In particular, the internal combustion engine 1 of a small motorcycle, due to its low output, is likely to have a large throttle valve 14 opening degree when going uphill or accelerating, and is therefore likely to enter a high-load operating state. When operating in this high-load operating state, the vehicle does not accelerate or decelerate because the intake air volume does not change even when the throttle valve 14 is opened or closed. In this high-load operating state where neither acceleration nor deceleration occurs, increasing the fuel injection amount according to the throttle opening degree results in a decrease in fuel efficiency.

[0052] In response to this, the control unit 51 controls the throttle valve 14 so that the opening of the throttle valve 14 does not exceed the upper limit value THLIM, thereby suppressing the fuel injection amount in the high load operating range and achieving low fuel consumption.

[0053] In the internal combustion engine control device 100 according to the present embodiment described above, a torque TQRLLINE corresponding to the detected rotation speed NE is derived from a first table that correlates the rotation speed NE of the internal combustion engine 1 with the torque TQRLLINE in a steady operating state, and a correction value MTQPACT corresponding to the detected rotation speed NE is derived from a second table that correlates the rotation speed NE with a correction value MTQPACT. The torque TQRLLINE derived from the first table is corrected with the correction value MTQPACT derived from the second table to derive the allowable torque TQTRGPACT, and an upper limit value THLIM of the opening of the throttle valve 14 of the internal combustion engine 1 is derived based on the derived allowable torque TQTRGPACT and the detected rotation speed NE, thereby achieving low fuel consumption.

[0054] 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. [Industrial Applicability]

[0055] As described above, the present invention can provide an internal combustion engine control device that can achieve low fuel consumption, and because of its versatile and universal nature, it is expected to be widely applicable to internal combustion engine control devices for vehicles such as saddle-ride vehicles. [Explanation of symbols]

[0056] 1...Internal combustion engine 2...Cylinder block 4...Piston 5...Connecting rod 6...Crankshaft 7...Relacta 8...Cylinder head 9...Combustion chamber 10...Spark plug 11...Intake pipe 12...Intake valve 14...Throttle valve 15...Exhaust pipe 16...Exhaust valve 50...Storage section 51...Control unit 100...Internal combustion engine control device 101...Internal combustion engine temperature sensor 102...Crank angle sensor 103...Intake pressure sensor 104...Throttle opening sensor 105...Accelerator opening sensor 106...Vehicle speed sensor 107...Injector 109...Catalyst 110...O2 sensor 111...Torque memory unit 112...Correction value storage unit 113...Upper limit value storage unit 114...Torque derivation section 115...Correction value derivation unit 116... Allowable torque calculation section 117...Upper limit value derivation section

Claims

[Claim 1] An internal combustion engine control device that derives an upper limit value of an opening degree of a throttle valve of an internal combustion engine based on a rotation speed of the internal combustion engine, a storage unit that stores a first table that associates the rotation speed with a torque in a steady operating state of the internal combustion engine, and stores a second table that associates the rotation speed with a correction value for correcting the torque; a control unit that derives the torque associated with the rotation speed detected in the first table, derives the correction value associated with the rotation speed detected in the second table, corrects the torque derived from the first table with the correction value derived from the second table, and derives an allowable torque, and derives the upper limit value based on the derived allowable torque and the detected rotation speed; An internal combustion engine control device comprising:

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