JP2021055562A - Internal combustion engine control device and control method - Google Patents

Abstract

To improve fuel efficiency through appropriately controlling a start and stop of oil jet injection according to an operation state of an internal combustion engine.SOLUTION: A control device of an internal combustion engine provided with an oil jet capable of injecting oil toward a piston which can reciprocate in a cylinder comprises: an operation state acquisition section which acquires an operation state of the internal combustion engine; an estimation section which estimates a fuel efficiency improvement degree when oil injection of the oil jet is stopped on the basis of at least a relation between the operation state to be acquired and a fuel consumption degree related to friction, of the internal combustion engine, varied with a reduction in heat generation quantity transmitted from the piston to the oil when the oil injection of the oil jet is stopped; and a control section which stops the oil injection when the estimated fuel efficiency improvement degree exceeds a predetermined threshold degree and executes the oil injection when the estimated fuel efficiency improvement degree is equal to or less than the predetermined threshold degree.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a control device and a control method for an internal combustion engine, and more particularly to a control device and a control method for an internal combustion engine including an oil jet for injecting cooling oil toward a piston.

As an example of a control device for an internal combustion engine equipped with an oil jet, when the operating state of the internal combustion engine is low, the injection of cooling oil from the oil jet toward the piston is stopped to reduce the cooling loss in the combustion chamber. A technique for reducing fuel consumption by reducing the amount has been proposed (see, for example, Patent Document 1).

JP-A-2009-156186

By the way, in the technique described in Document 1 above, when the operating state of the internal combustion engine is a low load, the injection of the cooling oil is uniformly stopped. However, when the injection of the cooling oil is stopped, the amount of heat dissipated from the piston to the oil is reduced. Therefore, depending on the operating condition of the internal combustion engine, when the oil jet is stopped, the oil temperature decreases and the viscosity of the oil increases as the amount of heat dissipated from the piston to the oil decreases, resulting in increased friction and fuel efficiency. May cause deterioration.

An object of the present disclosure technique is to reduce fuel consumption by appropriately controlling the injection and stopping of an oil jet according to the operating state of an internal combustion engine.

The device of the present disclosure is a control device for an internal combustion engine including an oil jet capable of injecting oil toward a piston that can reciprocate in a cylinder, and includes an operation state acquisition unit that acquires the operation state of the internal combustion engine. At least, based on the relationship between the acquired operating state and the degree of fuel consumption according to the friction of the internal combustion engine, which changes as the amount of heat radiated from the piston to the oil decreases due to the stoppage of oil injection of the oil jet. , The fuel consumption reduction degree estimation unit that estimates the fuel consumption reduction degree when the oil injection is stopped, and when the estimated fuel consumption reduction degree exceeds a predetermined threshold degree, the oil injection is stopped and the fuel consumption is said. A control unit for executing the oil injection when the degree of reduction is equal to or less than a predetermined degree of threshold is provided.

In addition, the fuel consumption reduction degree estimation unit includes the acquired cooling state in the cylinder, the cooling loss in the cylinder that decreases with the decrease in the amount of heat radiation due to the stoppage of the oil injection, and the combustion gas from the combustion chamber of the internal combustion engine. The fuel consumption reduction degree is further estimated based on the relationship with the fuel consumption degree according to the leakage, and the control unit determines when the total of the estimated fuel consumption reduction degrees exceeds the threshold degree. It is preferable to stop the oil injection and execute the oil injection when the total of the plurality of fuel consumption reduction degrees is equal to or less than the threshold degree.

Further, the fuel consumption reduction degree estimation unit responds to the acquired operating state and the drive loss of the pump that supplies the oil to the oil jet, which increases as the oil pressure rises due to the oil injection stop. The fuel consumption reduction degree is further estimated based on the relationship with the fuel consumption degree, and the control unit performs the oil injection when the sum of the estimated fuel consumption reduction degrees exceeds the threshold degree. It is preferable to stop the oil injection and execute the oil injection when the total of the plurality of low fuel consumption degrees is equal to or less than the threshold degree.

The method of the present disclosure is a control method of an internal combustion engine including an oil jet capable of injecting oil toward a piston that can reciprocate in a cylinder, and acquires, at least, the operating state of the internal combustion engine. The oil injection is performed based on the relationship between the operating state and the degree of fuel consumption according to the friction of the internal combustion engine, which changes as the amount of heat radiated from the piston to the oil decreases due to the stoppage of oil injection of the oil jet. The degree of fuel reduction when stopped is estimated, and when the estimated degree of fuel reduction exceeds a predetermined degree of threshold, the oil injection is stopped and the degree of reduction of fuel is equal to or less than the predetermined degree of threshold. , The oil injection is executed.

According to the technique of the present disclosure, it is possible to reduce fuel consumption by appropriately controlling the injection and stopping of the oil jet according to the operating state of the internal combustion engine.

It is a schematic overall block diagram which shows the internal combustion engine provided with the control device which concerns on this embodiment, and its peripheral structure. It is a schematic functional block diagram which shows the control apparatus which concerns on this embodiment and the related peripheral configurations. (A) is a first change factor map M1 showing the relationship between the operating state of the engine 10 and the degree of fuel consumption reduction, and (B) is a second change showing the relationship between the operating state of the engine 10 and the degree of fuel consumption reduction. The factor maps M2 and (C) are third change factor maps M3 showing the relationship between the operating state of the engine 10 and the degree of fuel consumption reduction. It is a chart diagram explaining the flow of oil injection and stop control by the control device which concerns on this embodiment.

Hereinafter, the control device and the control method for the internal combustion engine according to the present embodiment will be described with reference to the accompanying drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

[overall structure]
FIG. 1 is a schematic overall configuration diagram of an internal combustion engine (also referred to as an engine) provided with a control device according to the present embodiment and its peripheral configuration.

As shown in FIG. 1, the engine 10 includes a cylinder block 11 in which a cylinder 12 for accommodating a piston 20 so as to be reciprocally movable, a cylinder head 13 provided in an upper portion of the cylinder block 11, and a lower end of the cylinder block 11. It is provided with a crankcase 14 extending downward from the crankcase 14 and an oil pan 15 fixed to the lower part of the crankcase 14 to store oil. For the sake of illustration, FIG. 1 shows only one of the plurality of cylinders of the engine 10, and the other cylinders are not shown. The engine 10 may be either a plurality of cylinders or a single cylinder.

The cylinder head 13 is provided with an intake port 30 and an exhaust port 31. Further, the cylinder head 13 is provided with an injector 32 that directly injects fuel into the combustion chamber A partitioned by the top surface of the piston 20 and the wall surface of the cylinder 12. Further, the cylinder head 13 is provided with an intake valve 33 that introduces fresh air from the intake port 30 into the combustion chamber A by opening / closing operation, and an exhaust valve 34 that draws exhaust gas from the combustion chamber A to the exhaust port 31 by opening / closing operation. ing. The intake valve 33 and the exhaust valve 34 are opened and closed by the valve operating mechanisms 35 and 36 arranged on the upper part of the cylinder head 13, respectively. Oil is supplied to the valve operating mechanisms 35 and 36 from the oil gallery 40 described later. The engine 10 is not limited to the direct injection engine, and may be a premixed engine.

A small end portion 23 of the connecting rod 22 is connected to the piston 20 via a piston pin 21. A crankshaft 27 is connected to the large end 24 of the connecting rod 22 via a crank pin 25 and a crank arm 26. When the piston 20 reciprocates in the cylinder 12, this reciprocating motion is converted into a rotary motion by the connecting rod 22, and the crankshaft 27 rotates. Oil is supplied from the oil gallery 40 to a bearing (not shown) that pivotally supports the crank journal portion of the crankshaft 27 via an oil passage (not shown).

Further, inside the piston 20, an annular cooling channel 41 is formed in which oil is circulated to positively cool the piston 20. An oil inflow port 42 that opens downward and an oil outflow port 43 are communicated with the cooling channel 41. The oil injected from the oil jet 45, which will be described later, is taken into the cooling channel 41 from the oil inflow port 42 and circulated, and then discharged from the oil outflow port 43 toward the lower oil pan 15. .. A piston ring 28 that is in sliding contact with the inner wall of the cylinder 12 is mounted on the outer periphery of the piston 20. Oil discharged via the oil jet 45 is supplied to the sliding contact surface between the piston ring 28 and the cylinder 12.

An oil jet 45 for injecting oil supplied from the oil gallery 40 toward the oil inlet 42 of the piston 20 is provided near the lower end of the cylinder 12 of the cylinder block 11 (near the boundary position with the crankcase 14). There is. An oil jet valve 46 is provided between the oil gallery 40 and the oil jet 45. The oil jet valve 46 controls the injection of oil from the oil jet 45 in response to a command from the control device 100. When the oil jet valve 46 is closed, the oil passage from the oil gallery 40 to the oil jet 45 is cut off, and oil is not injected from the oil jet 45. On the other hand, when the oil jet valve 46 is in the open state, the oil passage from the oil gallery 40 to the oil jet 45 is opened, and oil is injected from the oil jet 45.

[Lubricating oil circuit]
An oil strainer 16 for removing foreign substances contained in the oil is immersed in the oil in the oil pan 15. A main oil passage 17 is connected to the oil strainer 16. The main oil passage 17 connects the oil strainer 16 and the oil gallery 40. The main oil passage 17 is provided with an oil pump 18 that pumps and pumps the oil in the oil pan 15.

The oil pump 18 is connected to the crankshaft 27 via a belt pulley or the like (not shown), and is driven by the power of the engine 10. When the oil pump 18 is driven, oil is pumped to the oil gallery 40 via the main oil passage 17, and the sliding elements such as valve mechanisms 35 and 36 and the bearings of the crankshaft 27 and each lubricating element are pumped from the oil gallery 40. And supplied to the oil jet 45. The oil pump 18 is, for example, a variable displacement pump, and supplies oil to each sliding element, each lubricating element, and an oil jet 45 by appropriately increasing or decreasing the volume of the control pressure chamber by an actuator (not shown). It is controlled so that the oil pressure for the pump is secured.

The oil gallery 40 is provided with an oil temperature sensor 91 that acquires the temperature of the oil flowing in the oil gallery 40 and a hydraulic sensor 92 that acquires the pressure. The engine rotation speed sensor 93 acquires the engine rotation speed Ne from the crankshaft 27. The accelerator opening sensor 94 acquires the fuel injection amount Q (injection instruction value to the injector 32) of the engine 10 according to the depression amount of the accelerator pedal (not shown). The sensor values of each of these sensors 91 to 94 are transmitted to the electrically connected control device 100.

[Control device]
FIG. 2 is a schematic functional block diagram showing the control device 100 according to the present embodiment and related peripheral configurations.

The control device 100 performs various controls such as the engine 10, and is configured to include a known CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input port, output port, and the like. ing. Further, the control device 100 includes an engine rotation speed acquisition unit 110, a fuel injection amount acquisition unit 120, a hydraulic pressure determination unit 130, a piston temperature estimation unit 140, a piston cooling determination unit 150, and a first fuel consumption reduction degree estimation unit. It has 160, a second fuel consumption reduction degree estimation unit 170, a third fuel consumption reduction degree estimation unit 180, a fuel consumption effect determination unit 190, and an oil jet valve control unit 200 as some functional elements. Each of these functional elements will be described as being included in the control device 100, which is integrated hardware in the present embodiment, but any part of these may be provided in separate hardware.

The engine rotation speed acquisition unit 110 is an example of the operating state acquisition unit of the present disclosure, and acquires the engine rotation speed Ne transmitted from the engine rotation speed sensor 93. The engine rotation speed Ne acquired by the engine rotation speed acquisition unit 110 is transmitted to the piston temperature estimation unit 140 and the fuel consumption reduction degree estimation units 160 to 180.

The fuel injection amount acquisition unit 120 is an example of the operating state acquisition unit of the present disclosure, and acquires the fuel injection amount Q transmitted from the accelerator opening sensor 94. The fuel injection amount Q acquired by the fuel injection amount acquisition unit 120 is transmitted to the piston temperature estimation unit 140 and the fuel consumption reduction degree estimation units 160 to 180.

The oil pressure determination unit 130 reaches the required oil pressure P for supplying oil to each sliding element, each lubrication element, and an auxiliary machine (not shown) based on the oil pressure Po transmitted from the oil pressure sensor 92. Judge whether or not it is. The determination result of the oil pressure determination unit 130 is transmitted to the oil jet valve control unit 200.

The piston temperature estimation unit 140 is used from the operating state of the engine 10 such as the engine rotation speed Ne transmitted from the engine rotation speed acquisition unit 110 and the fuel injection amount Q transmitted from the fuel injection amount acquisition unit 120, and the oil temperature sensor 91. The piston temperature Tp is estimated based on a model formula including the transmitted oil temperature or the like as an input value, or a map or the like. The piston temperature Tp estimated by the piston temperature estimation unit 140 is transmitted to the piston cooling determination unit 150.

The piston cooling determination unit 150 determines whether or not it is necessary to cool the piston 20 based on the piston temperature Tp transmitted from the piston temperature estimation unit 140. Specifically, the piston cooling determination unit 150 determines that the piston 20 needs to be cooled when the piston temperature Tp exceeds a predetermined threshold temperature T, and the piston temperature Tp is a predetermined threshold temperature T. In the following cases, it is determined that the piston 20 does not need to be cooled. Here, the threshold temperature T may be set according to the material of the piston 20 or the like in consideration of the life of the piston 20 or the like. The determination result of the piston cooling determination unit 150 is transmitted to the oil jet valve control unit 200.

The first fuel consumption reduction degree estimation unit 160 (an example of the fuel consumption reduction degree estimation unit of the present disclosure) is a friction change of each sliding element of the engine 10 when the oil injection from the oil jet 45 is stopped (hereinafter, the first change). Estimate the degree of fuel consumption reduction due to (called a factor). Here, the first change factor is a sliding element (for example, a crankshaft) due to a decrease in the amount of heat radiated from the piston 20 to the oil and a decrease in the oil temperature when the oil injection from the oil jet 45 is stopped. This includes an increase in friction between the bearings of 27, valve mechanisms 35, 36, etc.) and a decrease in friction between the piston 20 and the cylinder 12 due to an increase in the temperature of the piston 20.

Specifically, in the memory of the control device 100, the relationship between the operating state of the engine 10 and the degree of fuel consumption reduction (for example, points) according to the degree of fuel consumption due to the first change factor, which has been obtained in advance by experiments or the like. A defined first change factor map M1 (see FIG. 3A for details) is stored. In the present embodiment, the first change factor map M1 preferably has a plurality of maps M1 _{_1 for each oil temperature.} ~ M1 _{_n} is stored.

In these plurality of first change factor maps M1 _{_1 to M1 _n} , the degree of fuel consumption reduction is such that the operating state of the engine 10 moves from the low rotation / high load side region to the high rotation / low load side region (from the region ε). (The closer to the region λ), the greater the degree of fuel consumption reduction (higher score) is set. This is because when the injection of the oil jet is stopped, the friction of the sliding element increases due to the decrease in the oil temperature in any operating region, but in the region on the high rotation / low load side, the piston 20 This is because the friction between the sliding contact surface between the piston 20 and the cylinder 12 is reduced due to the temperature rise, and the fuel consumption is reduced.

The first fuel consumption reduction degree estimation unit 160 selects a map corresponding to the oil temperature transmitted from the oil temperature sensor 91 from _{a plurality of maps M1 _1 to M1 _n, and selects the selected map as the engine speed Ne and fuel.} By referring to the injection amount Q, the fuel consumption reduction degree D1 due to the first change factor when the oil injection from the oil jet 45 is stopped is estimated. The fuel consumption reduction degree D1 of the first change factor estimated by the first fuel consumption reduction degree estimation unit 160 is transmitted to the fuel consumption effect determination unit 190.

The second fuel consumption reduction degree estimation unit 170 (an example of the fuel consumption reduction degree estimation unit of the present disclosure) reduces the cooling loss in the cylinder 12 when the oil injection from the oil jet 45 is stopped, and the combustion from the combustion chamber A. The degree of fuel consumption reduction due to the reduction of gas leakage (hereinafter referred to as the second change factor) is estimated. Here, the second change factor is that the temperature of the piston 20 rises due to the stoppage of oil injection from the oil jet 45, and the amount of heat transfer from the combustion gas in the combustion chamber A to the piston 20 decreases accordingly. As a result, the change factor that reduces the cooling loss in the cylinder 12 and the temperature of the piston 20 rise, and the gap between the piston ring 28 and the cylinder 12 becomes narrower, so that combustion from the combustion chamber A into the crankcase 14 A change factor that reduces gas leakage.

Specifically, the memory of the control device 100 defines the relationship between the operating state of the engine 10 and the degree of fuel consumption reduction (for example, points) according to the degree of fuel consumption due to the second change factor, which was obtained in advance by experiments or the like. The second change factor map M2 (see FIG. 3B for details) is stored. In the present embodiment, the second change factor map M2 preferably stores a _{plurality of maps M2 _1 to M2 _n for each oil temperature.}

In these plurality of second change factor maps M2 _{_1 to M2 _n} , the degree of fuel consumption reduction is such that the operating state of the engine 10 moves from the low rotation / low load side region to the high rotation / high load side region (from region α). (Toward the region δ), the degree of fuel consumption reduction is set to be large (high score). This is because the amount of fuel injected into the combustion chamber A is small in the region on the low rotation / low load side, and even if the injection of the oil jet is stopped, the temperature of the piston 20 has the effect of reducing the cooling loss in the cylinder 12. Although it does not rise to the extent that it can be obtained, the amount of fuel injected into the combustion chamber A is large in the region on the high rotation / high load side, and when the injection of the oil jet is stopped, the temperature of the piston 20 cools in the cylinder 12. This is because the temperature rises to a temperature range where the effect of reducing loss can be obtained.

The second fuel consumption reduction degree estimation unit 170 selects a map corresponding to the oil temperature transmitted from the oil temperature sensor 91 from _{the plurality of maps M2 _1 to M2 _n, and selects the selected map as the engine speed Ne and the fuel.} By referring to the injection amount Q, the fuel consumption reduction degree D2 due to the second change factor when the oil injection from the oil jet 45 is stopped is estimated. The fuel consumption reduction degree D2 of the second change factor estimated by the second fuel consumption reduction degree estimation unit 170 is transmitted to the fuel consumption effect determination unit 190.

The third fuel consumption reduction degree estimation unit 180 (an example of the fuel consumption reduction degree estimation unit of the present disclosure) changes the work amount of the oil pump 18 when the oil injection from the oil jet 45 is stopped (hereinafter, also referred to as a third change factor). Estimate the degree of fuel consumption reduction. Here, the third change factor is that the work amount of the oil pump 18 is increased by increasing the oil pressure of the oil gallery 40 by stopping the oil injection of the oil jet 45, and the discharge flow rate of the oil pump 18 is decreased. The work load reduction of the oil pump 18 is included.

Specifically, the memory of the control device 100 defines the relationship between the operating state of the engine 10 and the degree of fuel consumption reduction (for example, points) according to the degree of fuel consumption due to the third change factor, which was obtained in advance by experiments or the like. The third change factor map M3 (see FIG. 3C for details) is stored. In the present embodiment, the third change factor map M3 preferably stores a _{plurality of maps M3 _1 to M3 _n for each oil temperature.}

In these plurality of third change factor maps M3 _{_1 to M3 _n} , the degree of fuel consumption reduction is such that the operating state of the engine 10 moves from the low rotation side region to the high rotation side region (from region μ to region υ). , The degree of fuel consumption reduction is set large (high score). This is because when the injection of the oil jet is stopped, the oil pressure in the oil gallery 40 rises, and the work load of the oil pump 18 increases accordingly, so that the pump drive loss of the engine 10 increases. In the region on the high engine speed side, the work of the oil pump 18 is due to the small difference between the pressure of the oil discharged from the oil pump 18 and the opening pressure of the relief valve (not shown) provided on the discharge outlet side of the oil pump 18. This is because the amount of increase is small. On the other hand, when a variable displacement type or a motor-driven oil pump is used, the target oil pressure is controlled according to the injection and stop of the oil jet. Therefore, by reducing the discharge amount of the oil pump 18 by stopping the oil jet, the drive loss of the oil pump of the engine 10 can be substantially reduced.

The third fuel consumption reduction degree estimation unit 180 selects a map corresponding to the oil temperature To transmitted from the oil temperature sensor 91 from _{the plurality of maps M3 _1 to M3 _n} , and sets the selected map as the engine rotation speed Ne. By referring to the fuel injection amount Q, the fuel consumption reduction degree D3 due to the third change factor when the oil injection from the oil jet 45 is stopped is estimated. The fuel consumption reduction degree D3 of the third change factor estimated by the third fuel consumption reduction degree estimation unit 180 is transmitted to the fuel consumption effect determination unit 190.

The fuel consumption effect determination unit 190 (an example of the control unit of the present disclosure) injects oil from the oil jet 45 based on the fuel consumption reduction degrees D1, D2, and D3 transmitted from the fuel consumption reduction degree estimation units 160 to 180. It is determined whether or not there is a fuel consumption reduction effect when the vehicle is stopped. Specifically, the fuel consumption effect determination unit 190 determines that there is a fuel consumption reduction effect when the total ΣD (= D1 + D2 + D3) of each fuel consumption reduction degree D1, D2, D3 exceeds a predetermined threshold score S. .. On the other hand, the fuel consumption effect determination unit 190 determines that there is no fuel consumption reduction effect when the total ΣD of each fuel consumption reduction degree D1, D2, D3 is equal to or less than a predetermined threshold score S. The determination result of the fuel efficiency effect determination unit 190 is transmitted to the oil jet valve control unit 200.

When the oil jet valve control unit 200 (an example of the control unit of the present disclosure) determines that the oil pressure determination unit 130 needs to increase the oil pressure, and when the fuel consumption effect determination unit 190 stops the oil injection. When it is determined that there is an effect of reducing fuel consumption, the oil jet valve 46 is controlled to be closed and the oil injection is stopped. On the other hand, when the piston cooling determination unit 150 determines that the piston 20 needs to be cooled, and when the fuel efficiency effect determination unit 190 stops the oil injection, the oil jet valve control unit 200 has a fuel efficiency reduction effect. When it is determined that there is no oil jet valve 46, the oil jet valve 46 is controlled to be in the open state and oil is injected.

In this way, friction change and cooling are performed by appropriately switching the injection and stop of the oil jet based on the fuel consumption reduction degrees D1 to D3 estimated according to the operating state of the engine 10 and the first to third change factors. Optimal oil jet injection control in consideration of loss reduction, oil pump drive loss, and the like can be realized, and the fuel efficiency performance of the engine 10 can be effectively improved.

Next, the flow of oil injection and stop control by the control device 100 according to the present embodiment will be described with reference to FIG. This control is started, for example, at the same time as the ON operation of the ignition switch (not shown) of the engine 10.

First, in step S110, the oil pressure determination unit 130 determines whether or not the oil pressure Po has reached the required oil pressure P based on the oil Po pressure transmitted from the oil pressure sensor 92. If yes, the control proceeds to step S120, and if no, the control proceeds to step S160.

In step S120, the piston temperature estimation unit 140 estimates the piston temperature based on the engine rotation speed Ne transmitted from the engine rotation speed acquisition unit 110, the fuel injection amount Q transmitted from the fuel injection amount acquisition unit 120, and the like. To do.

In step S130, the piston cooling determination unit 150 determines whether or not the piston temperature Tp exceeds the threshold temperature T that requires cooling, based on the piston temperature Tp transmitted from the piston temperature estimation unit 140. If yes, the control proceeds to step S170, and if no, the control proceeds to step S140.

In step S140, each fuel consumption reduction degree estimation unit 160 to 180 maps based on the engine rotation speed Ne transmitted from the engine rotation speed acquisition unit 110 and the fuel injection amount Q transmitted from the fuel injection amount acquisition unit 120. By referring to M1 to M3, the degree of fuel consumption reduction when the oil injection is stopped is estimated.

In step S150, the fuel consumption effect determination unit 190 has a threshold value having a fuel consumption reduction effect when ΣD stops oil injection based on the fuel consumption reduction degrees D1 to D3 transmitted from the fuel consumption reduction degree estimation units 160 to 180. It is determined whether or not the score S is exceeded. If yes, the control proceeds to step S160, and if no, the control proceeds to step S170.

As described above, if the result is negative (No) in step S110, or if the result is positive (Yes) in step S150, the control proceeds to step S160.

In step S160, the oil jet valve control unit 200 controls the oil jet valve 46 in the closed state and stops the oil injection. After that, this control is returned.

As described above, if the result is affirmative (Yes) in step S130, or if the case is negative (No) in step S150, the control proceeds to step S170.

In step S170, the oil jet valve control unit 200 controls the oil jet valve 46 to be in the open state and executes oil injection. After that, this control is returned.

According to the present embodiment described in detail above, the degree of fuel consumption reduction D1 due to the friction change of each sliding element of the engine 10 is estimated from the first change factor map M1, and the cooling inside the cylinder 12 is estimated from the second change factor map M2. The fuel consumption reduction degree D2 due to the reduction of loss is estimated, and further, the fuel consumption reduction degree D3 due to the change in the work amount of the oil pump 18 is estimated from the third change factor map M3. Then, based on these estimated fuel consumption reduction degrees D1 to D3, the injection and stop of the oil jet are appropriately switched. As a result, optimum oil jet injection control in consideration of friction change of the engine 10, reduction of cooling loss, drive loss of the oil pump, etc. can be realized, and the fuel efficiency performance of the engine 10 can be effectively improved. Can be done.

[Other]
The present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

For example, in the above embodiment, the control device 100 has been described as having the first to third fuel consumption reduction degree estimation units 160 to 180 as functional elements, but any one of these estimation units 160, 170, 180 or one of them or It may be configured to include two functional elements. When only one of the estimation units 160 to 180 is provided, the injection and stop of the oil jet can be determined by simply comparing the estimated fuel consumption reduction degrees D1, D2, or D3 with the threshold score S. Good.

Further, for example, in the above embodiment, the oil pump 18 has been described as a variable capacitance type driven by the power of the engine 10, but the oil pump 18 may be a fixed capacitance type. In this case, the load on the engine 10 can be reduced by connecting the oil pump 18 to the engine 10 via a disconnection mechanism such as a clutch and disconnecting the disconnection mechanism.

Further, the oil pump 18 may be an electric oil pump driven by the power of a motor. In this case, the power consumption can be reduced by stopping the oil pump 18.

10 engine (internal combustion engine)
12 Cylinder 18 Oil pump 20 Piston 27 Crankshaft 28 Piston ring 35, 36 Valve mechanism 40 Oil gallery 45 Oil jet 46 Oil jet valve 100 Control device 110 Engine rotation speed acquisition unit (operating state acquisition unit)
120 Fuel injection amount acquisition unit (operating state acquisition unit)
160 1st fuel consumption reduction degree estimation unit (fuel consumption reduction degree estimation part)
170 Second fuel consumption reduction degree estimation unit (fuel consumption reduction degree estimation unit)
180 Third fuel consumption reduction degree estimation unit (fuel consumption reduction degree estimation unit)
190 Fuel efficiency effect judgment unit (control unit)
200 Oil jet valve control unit (control unit)

Claims (4)

A control device for an internal combustion engine equipped with an oil jet capable of injecting oil toward a piston that can reciprocate in a cylinder.
An operating state acquisition unit that acquires the operating state of the internal combustion engine, and
At least, based on the relationship between the acquired operating state and the degree of fuel consumption according to the friction of the internal combustion engine, which changes as the amount of heat radiated from the piston to the oil decreases due to the stoppage of oil injection of the oil jet. , The fuel consumption reduction degree estimation unit that estimates the fuel consumption reduction degree when the oil injection is stopped, and
A control unit that stops the oil injection when the estimated fuel consumption reduction degree exceeds a predetermined threshold value and executes the oil injection when the fuel consumption reduction degree is equal to or less than a predetermined threshold value. A control device for an internal combustion engine, which comprises. The fuel consumption reduction degree estimation unit includes the acquired cooling state in the cylinder, the cooling loss in the cylinder, which decreases as the amount of heat radiation decreases due to the stoppage of oil injection, and the leakage of combustion gas from the combustion chamber of the internal combustion engine. The degree of fuel consumption reduction is further estimated based on the relationship with the degree of fuel consumption according to the above.
The control unit stops the oil injection when the estimated total of the plurality of fuel consumption reduction degrees exceeds the threshold value, and when the total of the plurality of fuel consumption reduction degrees is equal to or less than the threshold value. The control device for an internal combustion engine according to claim 1, wherein the oil injection is executed. The fuel consumption reduction degree estimation unit consumes fuel according to the drive loss of the pump that supplies the oil to the oil jet, which increases as the oil pressure rises due to the acquired operating state and the oil injection stop. Based on the relationship with the degree, the fuel consumption reduction degree is further estimated, and the fuel consumption reduction degree is further estimated.
The control unit stops the oil injection when the estimated total of the plurality of fuel consumption reduction degrees exceeds the threshold value, and when the total of the plurality of fuel consumption reduction degrees is equal to or less than the threshold value. The control device for an internal combustion engine according to claim 1 or 2, wherein the oil injection is executed. A control method for an internal combustion engine equipped with an oil jet capable of injecting oil toward a piston that can reciprocate in a cylinder.
Acquire the operating state of the internal combustion engine,
At least, based on the relationship between the acquired operating state and the degree of fuel consumption according to the friction of the internal combustion engine, which changes as the amount of heat dissipated from the piston to the oil decreases due to the stoppage of oil injection of the oil jet. , Estimate the degree of fuel consumption reduction when the oil injection is stopped,
The feature is that the oil injection is stopped when the estimated fuel consumption reduction degree exceeds a predetermined threshold value, and the oil injection is executed when the fuel consumption reduction degree is equal to or less than the predetermined threshold value. Control method of internal combustion engine.

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