Internal combustion engine control device

Abstract

Provided is an internal combustion engine control device capable of suppressing a decrease in the pressure of engine oil supplied to a hydraulic device when the rotational speed of an internal combustion engine decreases. An internal combustion engine control device (10) controls an internal combustion engine (20) that is applied to a vehicle (100) and that is provided with a dry sump type engine oil supply device (40) that supplies engine oil to hydraulic equipment. The internal combustion engine control device increases the amount of gas sucked into a cylinder (30) of the internal combustion engine when the rotational speed of the internal combustion engine is reduced.

Description

TECHNICAL FIELD

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

[0002] There is known an internal combustion engine provided with a dry sump type engine oil supply device (for example, refer to Patent Literature 1).

[0003] [Prior Art Literature] [Patent Literature] [Patent Literature 1] Japanese Patent Application Publication No. 2015-113820

[0004] In an internal combustion engine provided with a dry sump type engine oil supply device, the pressure inside the internal combustion engine including the crank chamber becomes very low, and therefore, for example, there is a tendency that the pressure (hydraulic pressure) of engine oil supplied to a hydraulic device such as a variable valve timing mechanism (VVT mechanism) mounted on the internal combustion engine becomes low. In addition, in a case where the oil pump that supplies engine oil is a mechanical oil pump that operates by the power of the internal combustion engine, when the rotational speed of the internal combustion engine decreases, the discharge pressure of the oil pump decreases, and therefore, there is a tendency that the hydraulic pressure gradually becomes low. If the hydraulic pressure becomes low like this, the operation of the hydraulic device can possibly become abnormal. SUMMARY

[0005] An object of the present application is to provide an internal combustion engine control device capable of suppressing a decrease in the pressure of engine oil supplied to a hydraulic device when the rotational speed of an internal combustion engine decreases.

[0006] The internal combustion engine control device of the present application controls an internal combustion engine that is applied to a vehicle and that is provided with a dry sump type engine oil supply device that supplies engine oil to a hydraulic device. The internal combustion engine control device of the present application is configured to increase the amount of gas taken into a cylinder of the internal combustion engine in a case where the rotational speed of the internal combustion engine decreases.

[0007] According to the present application, the amount of gas taken into a cylinder of an internal combustion engine increases when the rotational speed of the internal combustion engine decreases. Thereby, the amount of gas (so-called blow-by gas) that flows out of the cylinder to the crank chamber of the internal combustion engine increases. Therefore, a decrease in the pressure inside the crank chamber of the internal combustion engine and the like is suppressed, and as a result, a decrease in the pressure of engine oil supplied to a hydraulic device of the internal combustion engine is suppressed.

[0008] The constituent elements of the present application are not limited to the embodiments of the present application described below with reference to the drawings. Other objects, other features, and other advantages of the present application will be readily understood from the description of the embodiments of the present application given herein with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1is a diagram showing an internal combustion engine control device of an embodiment of the present application. Figure 2 is a flowchart showing a routine executed by an internal combustion engine control device of an embodiment of the present application. DETAILED DESCRIPTION

[0010] Hereinafter, an internal combustion engine control device of an embodiment of the present application will be described with reference to the drawings. Figure 1 An internal combustion engine control device 10 of an embodiment of the present application is shown in FIG. 1. The internal combustion engine control device 10 (hereinafter, simply referred to as "control device 10") is applied to an internal combustion engine 20, and controls the operation of the internal combustion engine 20 as shown in FIG. 1. The internal combustion engine 20 is mounted on a vehicle 100. Hereinafter, the vehicle 100 can be a vehicle directly driven by an operator (i.e., a driver of the vehicle 100) who is on board the vehicle 100, or can be a vehicle remotely driven by an operator (i.e., a remote operator of the vehicle 100) who is located at a remote place from the vehicle 100. In addition, the vehicle 100 can be a vehicle that travels only by a manual driving operation, or can be a vehicle that travels only by an automatic driving control, or can be a vehicle that travels by a manual driving operation and an automatic driving control. Figure 1

[0011] As shown in FIG. 1, the control device 10 is provided with an ECU (Electronic Control Unit) 90 as a control device. The ECU 90 is provided with a microcomputer as a main part. The microcomputer includes a CPU, a ROM, a RAM, and a storage medium such as a non-volatile memory, and an interface, and the like. The CPU realizes various functions by executing an instruction or a program or a routine stored in the storage medium. In particular, in the present example, the control device 10 stores a program that realizes various controls performed by the control device 10 in the storage medium. Figure 1

[0012] Further, in the present example, the control device 10 is provided with only one ECU 90, but can be configured to be provided with a plurality of ECUs, and the functions of the control device 10 described below can be respectively shared by the respective ECUs.

[0013] In addition, the control device 10 can be configured to be capable of updating (upgrading) the program stored in the storage medium by wireless communication (for example, Internet communication) with an external device.

[0014] A main body (internal combustion engine main body 21) of the internal combustion engine 20 is constituted by a cylinder head 22 and a cylinder block 23. In addition, the internal combustion engine 20 is provided with an intake valve 24, an exhaust valve 25, a spark plug 26, a fuel injection valve 27, and a piston 28. In addition, a plurality of (four in the present example) cylinders 30 are formed in the internal combustion engine main body 21.

[0015] ​​An intake passage 31 and an exhaust passage 32 are connected to the engine main body 21. A surge tank 33 is formed in the intake passage 31. A throttle valve 34 is provided in the intake passage 31 on the upstream side of the surge tank 33. Further, a compressor 35 of a supercharger is provided in the intake passage 31 on the upstream side of the throttle valve 34.

[0016] The internal combustion engine 20 is provided with an engine oil supply device 40 of a dry sump type. The engine oil supply device 40 is provided with an oil pickup pump 41, an oil pump 42, and an oil tank 43. The oil pickup pump 41 draws engine oil from the crank chamber 29 of the internal combustion engine 20, and delivers the drawn engine oil to the oil tank 43 via an oil discharge passage 47. The inside of the oil tank 43 is partitioned by a separator 44. In the engine oil delivered to the oil tank 43, so-called blow-by gas is contained, and the blow-by gas is separated from the engine oil by the separator 44.

[0017] The oil tank 43 is connected to the intake passage 31 on the upstream side of the compressor 35 via an upstream blow-by passage 45a. In addition, the oil tank 43 is connected to the surge tank 33 via a downstream blow-by passage 45b. In addition, an upstream flow rate adjusting valve 46a is provided in the upstream blow-by passage 45a, and a downstream flow rate adjusting valve 46b is provided in the downstream blow-by passage 45b. The upstream flow rate adjusting valve 46a is opened when the pressure in the intake passage 31 on the upstream side of the compressor 35 is lower than the pressure in the oil tank 43, whereby the blow-by gas is introduced into the intake passage 31 via the upstream blow-by passage 45a. In addition, the downstream flow rate adjusting valve 46b is opened when the pressure in the surge tank 33 is lower than the pressure in the oil tank 43, whereby the blow-by gas is introduced into the intake passage 31 via the downstream blow-by passage 45b.

[0018] The oil pump 42 supplies the engine oil stored in the oil tank 43 to movable portions and the like of the engine main body 21 via an oil supply passage 48, and supplies the engine oil to hydraulic equipment of the internal combustion engine 20. The engine oil supplied to the movable portions and the like of the engine main body 21 is used for lubricating the movable portions and the like. In addition, the engine oil supplied to the hydraulic equipment of the internal combustion engine 20 is used as working oil for operating the hydraulic equipment.

[0019] Further, in this example, the intake passage 31 on the upstream side of the connection portion of the upstream blow-by passage 45a and the intake passage 31 is connected to the inside of the engine main body 21 by a fresh air passage 49.

[0020] Thus, when the pressure in the inside of the engine main body 21 is lower than the pressure in the intake passage 31, fresh air is introduced from the intake passage 31 to the inside of the engine main body 21 via the fresh air passage 49.

[0021] In addition, the oil pickup pump 41 and the oil pump 42 are operated by the power of the internal combustion engine 20.

[0022] Additionally, a speed sensor 50 (or crankshaft angle sensor) is electrically connected to the ECU 90. The control unit 10 detects the speed of the internal combustion engine 20 via the speed sensor 50.

[0023] <Operation of the Control Device>

[0024] Next, the operation of the control device 10 will be explained.

[0025] As described above, the return oil pump 41 draws engine oil from the internal combustion engine body 21, resulting in a relatively low pressure inside the internal combustion engine body 21. Meanwhile, engine oil is supplied to the movable parts of the internal combustion engine body 21. Consequently, due to the low pressure inside the internal combustion engine body 21, the hydraulic pressure in the oil supply passage 48 decreases. Furthermore, when the speed of the internal combustion engine 20 decreases, the discharge pressure of the oil pump 42 decreases, further reducing the hydraulic pressure in the oil supply passage 48. Since the oil supply passage 48 also supplies engine oil to the hydraulic equipment of the internal combustion engine 20, the decrease in hydraulic pressure in the oil supply passage 48 affects the operation of the hydraulic equipment.

[0026] Therefore, the control device 10 executes at predetermined time intervals. Figure 2 The routine shown is used to suppress the drop in hydraulic pressure in the oil supply passage 48 when the speed of the internal combustion engine 20 decreases.

[0027] That is, when the predetermined timing is reached, the control device 10 starts from... Figure 2 The routine shown begins at step S200, which leads to step S210, where it is determined whether the incremental condition C1 is met. Incremental condition C1 is the condition that the speed of the internal combustion engine 20 decreases. Furthermore, the speed of the internal combustion engine 20 decreases at the start of deceleration of the vehicle 100 or immediately after the idling of the internal combustion engine 20 ends.

[0028] If the control device 10 determines "no" in step S210, it directly proceeds to step S295, temporarily terminating the current routine. On the other hand, if the control device 10 determines "yes" in step S210, it proceeds to step S220 to perform incremental intake gas control, and then proceeds to step S295, temporarily terminating the current routine.

[0029] Intake gas increment control is a control that increases the amount of gas drawn into the cylinder 30 of the internal combustion engine 20. In this example, intake gas increment control is a control that increases the opening of the throttle valve 34.

[0030] Thus, when the increase condition C1 is satisfied, i.e., when the rotational speed of the internal combustion engine 20 is reduced, the intake gas increase control is executed to increase the amount of the gas taken into the cylinder 30, whereby the amount of the gas (blow-by gas) flowing from the cylinder 30 through the space between the piston 28 and the cylinder inner wall 30s to the crank chamber 29 is increased. Therefore, the reduction in the pressure inside the internal combustion engine main body 21 can be suppressed, and as a result, the reduction in the pressure of the engine oil supplied to the hydraulic equipment can be suppressed.

[0031] In addition, the present application is not limited to the above-described embodiments, and various modifications can be employed within the scope of the present application.

[0032] [Label Explanation]

[0033] 10... control device, 20... internal combustion engine, 29... crank chamber, 30... cylinder, 34... throttle valve, 41... oil return pump, 42... oil pump, 43... oil tank, 50... rotational speed sensor, 90... ECU, 100... vehicle.

Claims

1. An internal combustion engine control device for controlling an internal combustion engine used in a vehicle, wherein the internal combustion engine includes a dry sump type engine oil supply device for supplying engine oil to a hydraulic system, wherein... The internal combustion engine control device is configured to increase the amount of gas drawn into the cylinder of the internal combustion engine when the engine speed decreases.

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