JP6984208B2 - Internal combustion engine control device - Google Patents

Description

The present invention relates to a control device for an internal combustion engine.

For example, in an internal combustion engine for a vehicle, one provided with an oil jet for injecting cooling oil toward a piston is known. In such an internal combustion engine, the oil discharged from the oil pump rotationally driven by the crankshaft is stored in the oil gallery, and the supply of oil from the oil gallery to the oil jet is controlled by opening and closing the oil jet valve. ing.

JP-A-2015-169113 Japanese Unexamined Patent Publication No. 2015-045287

However, in such an internal combustion engine, when the oil jet valve is closed to stop the oil injection from the oil jet, the oil pressure in the oil gallery increases and the pump driving force required to drive the oil pump increases. do. This may increase the pump drive loss of the internal combustion engine and deteriorate fuel efficiency.

Therefore, the present invention has been conceived in view of such circumstances, and an object thereof is to provide a control device for an internal combustion engine capable of suppressing an increase in pump drive loss when oil injection from an oil jet is stopped.

According to one aspect of the invention
It is a control device for an internal combustion engine.
The internal combustion engine is directed toward a piston, an oil pump that is rotationally driven by a crank shaft, a variable mechanism for making the discharge flow rate of the oil pump variable, an oil gallery that stores oil discharged from the oil pump, and a piston. It is equipped with an oil jet that injects oil and an oil jet valve that controls the supply of oil from the oil gallery to the oil jet.
The control device comprises the variable mechanism and a control unit configured to control the oil jet valve.
The control unit is provided with a control device for an internal combustion engine, which controls the variable mechanism according to the opening degree of the oil jet valve and controls the discharge flow rate of the oil pump.

Preferably, the control unit controls the variable mechanism so that the smaller the opening degree of the oil jet valve, the smaller the discharge flow rate of the oil pump.

Preferably, the control device further comprises a hydraulic sensor for detecting the hydraulic pressure of the oil gallery.
The control unit calculates the basic target flow rate of the oil pump based on the opening degree of the oil jet valve, and calculates a feedback correction term based on the difference between the hydraulic pressure detected by the hydraulic pressure sensor and the predetermined target hydraulic pressure. Then, the basic target flow rate is corrected by the feedback correction term to calculate the corrected target flow rate, and the variable mechanism is controlled so that the actual discharge flow rate becomes equal to the corrected target flow rate.

According to the present invention, it is possible to suppress an increase in pump drive loss when the oil injection from the oil jet is stopped.

It is a schematic diagram which shows the structure of embodiment of this invention. It is a flowchart of a control routine. A map for calculating the target flow rate of the oil pump is shown. It is a flowchart of the control routine of another embodiment. It is a schematic diagram which shows the structure of the modification.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the present invention is not limited to the following embodiments.

FIG. 1 shows a lubricating oil supply system mounted on an internal combustion engine (also referred to as an engine) according to an embodiment of the present invention. The engine is a diesel engine for vehicles, and the vehicle is a large vehicle such as a truck. However, the type, type, use and the like of the vehicle and the engine are not particularly limited. For example, the vehicle may be a small vehicle such as a passenger car, and the engine may be a gasoline engine.

The engine (indicated by E for convenience) includes an oil pan 1 for storing oil and an oil pump 2 for sucking and discharging the oil stored in the oil pan 1. The oil pump 2 is rotationally driven by the crankshaft 3 of the engine. The oil pump 2 is a well-known variable capacity oil pump, and is integrally provided with a variable mechanism 4 for making the discharge flow rate variable. The variable mechanism 4 may be provided separately.

A bypass valve 5, an inlet gallery 6 and an oil cooler 7 are provided on the downstream side of the oil pump 2. The bypass valve 5 is composed of a three-way solenoid valve, and distributes the oil supplied from the oil pump 2 to the inlet gallery 6 and the oil cooler 7 at a predetermined distribution ratio. The oil cooler 7 is a water-cooled type and has a cooling water passage 8 through which engine cooling water as a refrigerant flows. The oil cooled through the oil cooler 7 is sent to the inlet gallery 6 where it is mixed with the uncooled oil that has not passed through the oil cooler 7. As a result, the temperature of the oil is adjusted.

Here, the flow of oil directly from the bypass valve 5 to the inlet gallery 6 is the main flow, and the flow of oil from the bypass valve 5 to the inlet gallery 6 via the oil cooler 7 is the bypass flow. Further, in the bypass valve 5, the valve state in which all the oil supplied from the oil pump 2 flows to the inlet gallery 6 and does not flow to the oil cooler 7 is set to a fully closed state, that is, a state of opening = 0 (%). On the other hand, the valve state in which all the oil supplied from the oil pump 2 flows into the oil cooler 7 and does not flow into the inlet gallery 6 is set to a fully open state, that is, a state of opening = 100 (%). The opening degree of the bypass valve 5 is continuously variable from 0 (%) to 100 (%) and therefore the supplied oil can be distributed to the inlet gallery 6 and the oil cooler 7 at any distribution ratio. Is. By controlling the flow rate of the oil distributed to the oil cooler 7, the temperature of the oil after being merged at the inlet gallery 6 can be appropriately controlled.

The oil stored in the inlet gallery 6 is sent to the main oil gallery 11 through the oil filter 9 and the overflow valve 10. Here, two oil filters 9 are installed in parallel, but the number is arbitrary. The overflow valve 10 is a valve that opens when the hydraulic pressure on the inlet side, that is, the inlet gallery 6 exceeds a predetermined valve opening pressure, and opens the valve when, for example, the oil filter 9 is closed to protect the system. ..

The oil gallery 11 is, for example, a relatively large-capacity oil reservoir formed inside a cylinder block, from which oil is supplied to each lubricating portion of the engine. Such a lubrication unit includes, for example, an intake / exhaust valve mechanism Lb1, a turbocharger Lb2, and an EGR valve Lb3.

The engine is also provided with an oil jet 12 that injects oil toward a piston (not shown), and oil is supplied from the oil gallery 11 to the oil jet 12.

However, an oil jet valve 13 is provided between the oil gallery 11 and the oil jet 12, and the oil jet valve 13 controls the supply of oil from the oil gallery 11 to the oil jet 12, and eventually the oil injection from the oil jet 12. It is supposed to be done.

The oil jet valve 13 is composed of a two-way solenoid valve, and its opening degree is continuously variable from 0 (%) to 100 (%). Therefore, an arbitrary flow rate of oil can be injected from the oil jet 12. When the opening degree of the oil jet valve 13 is 100 (%), that is, when the oil jet valve 13 is in the fully open state, the injection flow rate from the oil jet 12 becomes maximum. On the contrary, when the opening degree of the oil jet valve 13 is 0 (%), that is, when the oil jet valve 13 is in the fully closed state, the injection flow rate from the oil jet 12 becomes the minimum.

In the present embodiment, another oil filter 14 is provided by bypassing the oil jet valve 13, and even when the oil jet valve 13 is fully closed, the oil with a very small flow rate flows from the oil gallery 11 through the oil filter 14 to the oil jet 12. It flows to the oil jet 12 and is constantly discharged from the oil jet 12. However, such a bypass route and the oil filter 14 are not essential and can be omitted.

On the other hand, the control device according to the present embodiment includes a control unit or an electronic control unit (hereinafter referred to as "ECU") 100 forming a controller, and sensors described later. The ECU 100 includes a CPU, a ROM, a RAM, an input / output port, a storage device, and the like. The ECU 100 is configured and programmed to control the variable mechanism 4, the bypass valve 5, and the oil jet valve 13 of the oil pump 2.

Regarding the sensors, a hydraulic pressure sensor 21 for detecting the oil pressure in the oil gallery 11 and an oil temperature sensor 22 for detecting the oil temperature in the oil gallery 11 are provided, and the output signals of these sensors are transmitted to the ECU 100. Sent.

Next, the control of this embodiment will be described.

At the time of oil injection from the oil jet 12, the ECU 100 opens the oil jet valve 13. Then, the oil in the oil gallery 11 having a relatively high pressure is sent to the oil jet 12, and the oil is vigorously ejected from the oil jet 12 toward the piston. At this time, the ECU 100 controls the opening degree of the oil jet valve 13 according to a separately estimated piston temperature or the like, and controls the oil injection flow rate from the oil jet 12. For example, the higher the piston temperature, the higher the oil injection flow rate.

On the other hand, when the oil injection from the oil jet 12 is stopped, the ECU 100 controls the oil jet valve 13 to be closed, that is, in a fully closed state. As a result, as described above, the oil having a very small flow rate simply leaks from the oil jet 12.

By the way, when the oil jet valve 13 is fully closed, the hydraulic pressure in the oil gallery 11 increases, and eventually the pressure of the entire system on the outlet side of the oil pump 2 increases. Then, the pump driving force required to drive the oil pump 2 increases. As a result, the pump drive loss of the engine E increases, and the fuel consumption may deteriorate.

Therefore, the ECU 100 of the present embodiment controls the variable mechanism 4 according to the opening degree of the oil jet valve 13 to control the discharge flow rate of the oil pump 2. Specifically, the ECU 100 controls the variable mechanism 4 so that the smaller the opening degree of the oil jet valve 13, the smaller the discharge flow rate of the oil pump 2.

More specifically, the ECU 100 controls the discharge flow rate of the oil pump 2 by repeatedly executing the routine shown in FIG. 2 every predetermined calculation cycle τ (for example, 10 msec).

In step S101, the ECU 100 acquires (%) the opening degree V of the oil jet valve 13. Since the opening degree V of the oil jet valve 13 is controlled by the ECU 100 itself, the indicated opening degree sent from the ECU 100 to the oil jet valve 13 is acquired here.

Next, in step S102, the ECU 100 calculates the target flow rate Qb, which is the target value of the discharge flow rate of the oil pump 2 corresponding to the opening degree V, from a predetermined map as shown in FIG. As shown in the figure, in the map, the target flow rate Qb that becomes smaller as the opening degree V becomes smaller is input. The target flow rate Qb is maximum when the fully open opening = 100 (%) and minimum when the fully closed opening = 0 (%).

Next, in step S103, the ECU 100 controls the variable mechanism 4 so that the actual discharge flow rate of the oil pump 2 becomes equal to the calculated target flow rate Qb, and controls the discharge flow rate (pump flow rate) of the oil pump 2.

According to this control, when the oil jet valve 13 is in the fully closed state, the target flow rate Qb is minimized, so that the pump driving force can be effectively reduced. Therefore, it is possible to effectively suppress an increase in pump drive loss when the oil injection from the oil jet 12 is stopped, and eventually deterioration in fuel efficiency.

Further, even when the opening degree of the oil jet valve 13 is an intermediate opening degree between 0 (%) and 100 (%), the target flow rate Qb can be lowered from the maximum value, and the pump driving force is lowered. Can be made to. Therefore, even at this time, it is possible to effectively suppress an increase in pump drive loss and deterioration of fuel efficiency.

On the other hand, when the opening degree of the oil jet valve 13 is 100 (%), the target flow rate Qb is set as the maximum value, oil injection at a sufficient flow rate can be executed from the oil jet 12, and the piston can be reliably cooled. Therefore, the desired performance of the oil jet 12 can be surely satisfied.

As described above, according to the present embodiment, the ECU 100 controls the variable mechanism 4 according to the opening degree V of the oil jet valve 13 and controls the discharge flow rate of the oil pump 2, so that the oil injection from the oil jet 12 is stopped. It is possible to suppress an increase in pump drive loss over time.

Next, another embodiment will be described. While the above-mentioned basic embodiment controls the variable mechanism 4 by the feedforward (F / F) control as shown in FIG. 2, the other embodiment has the feedforward control as shown in FIG. It differs from the above-mentioned basic embodiment in that the variable mechanism 4 is controlled by a combination of feedback (F / B) control.

In step S201, the ECU 100 acquires the opening degree V (%) of the oil jet valve 13 and the oil pressure (gallery pressure) P in the oil gallery 11 detected by the oil pressure sensor 21.

Next, in step S202, the ECU 100 calculates the target flow rate Qb corresponding to the opening degree V from the map shown in FIG. 3, as in step S102. This target flow rate Qb forms a feedforward term corresponding to the feedforward control portion, and also forms a basic target flow rate that is the basis of the corrected target flow rate Qb'calculated later.

Next, in step S203, the ECU 100 calculates the feedback (F / B) correction term ΔQ based on the difference ΔP (= Pt−P) between the acquired oil pressure P and the predetermined target oil pressure Pt. This feedback correction term ΔQ forms a feedback term corresponding to the feedback control portion, and also forms a correction term for correcting the basic target flow rate Qb. The feedback correction term ΔQ is zero when the difference ΔP is zero, and is a value that increases as the difference ΔP increases. The feedback correction term ΔQ is calculated based on the difference ΔP according to a known method such as PID control.

Next, in step S204, the ECU 100 adds the feedback correction term ΔQ to the target flow rate Qb to calculate the corrected target flow rate Qb'(Qb'= Qb + ΔQ).

Finally, in step S205, the ECU 100 controls the variable mechanism 4 so that the actual discharge flow rate of the oil pump 2 becomes equal to the calculated corrected target flow rate Qb', and adjusts the discharge flow rate (pump flow rate) of the oil pump 2. Control.

According to this control, the hydraulic pressure P in the oil gallery 11 is feedback-controlled so as to approach the target hydraulic pressure Pt. Therefore, this also effectively increases the pump drive loss and deteriorates the fuel consumption when the oil injection from the oil jet 12 is stopped. It can be suppressed. That is, when the oil jet valve 13 is fully closed when the oil injection is stopped and the oil pressure P in the oil gallery 11 rises from the target oil pressure Pt, the discharge flow rate of the oil pump 2 is reduced in order to lower the oil pressure P to the target oil pressure Pt. Can be reduced. Therefore, it is possible to further promote the decrease in hydraulic pressure in the oil gallery 11 and further suppress the increase in pump drive loss.

Although the embodiments of the present invention have been described in detail above, various other embodiments of the present invention can be considered.

(1) For example, the configuration shown in FIG. 1 can be changed as shown in FIG. In the modification shown in FIG. 5, the oil pump 2 itself is a constant capacity type that is not a variable capacity type, but by changing the relative rotation speed of the oil pump 2 with respect to the crankshaft of the engine E, the oil pump 2 The discharge flow rate is substantially variable. Therefore, a transmission 30 is provided between the crankshaft of the engine E and the oil pump 2, and the discharge flow rate of the oil pump 2 is changed by changing the gear ratio of the transmission 30. Therefore, the transmission 30 forms a variable mechanism 4 for making the discharge flow rate of the oil pump 2 variable. The transmission 30 is controlled by the ECU 100. The transmission 30 is preferably a continuously variable transmission such as a CVT.

(2) The oil jet valve 13 may be controlled only to be fully open and fully closed. That is, it may be controlled so as to be fully opened when the oil is injected from the oil jet 12 and fully closed when the oil injection is stopped. The map of FIG. 3 can be used at this time as well. Alternatively, instead of using the map of FIG. 3, two target flow rates, which are simply large when fully open and small when fully closed, may be set in advance.

(3) The configurations shown in FIGS. 1 and 5 can be changed to be simpler, for example. For example, the temperature control unit including the oil cooler 7 may be omitted. Further, the oil filter 9 does not necessarily have to be in the position shown in the figure, and may be omitted.

The embodiment of the present invention is not limited to the above-described embodiment, and all modifications, applications, and equivalents included in the idea of the present invention defined by the scope of claims are included in the present invention. Therefore, the present invention should not be construed in a limited manner and can be applied to any other technique belonging to the scope of the idea of the present invention.

2 Oil pump 3 Crankshaft 4 Variable mechanism 11 Oil gallery 12 Oil jet 13 Oil jet valve 100 Electronic control unit (ECU)
E Internal combustion engine (engine)

Claims (2)

It is a control device for an internal combustion engine.
The internal combustion engine is directed toward a piston, an oil pump that is rotationally driven by a crank shaft, a variable mechanism for making the discharge flow rate of the oil pump variable, an oil gallery that stores oil discharged from the oil pump, and a piston. It is equipped with an oil jet that injects oil and an oil jet valve that controls the supply of oil from the oil gallery to the oil jet.
The control device comprises the variable mechanism and a control unit configured to control the oil jet valve.
The control unit controls the variable mechanism according to the opening degree of the oil jet valve, and controls the discharge flow rate of the oil pump .
The control device further includes a hydraulic pressure sensor for detecting the hydraulic pressure of the oil gallery.
The control unit calculates the basic target flow rate of the oil pump based on the opening degree of the oil jet valve, and calculates a feedback correction term based on the difference between the hydraulic pressure detected by the hydraulic pressure sensor and the predetermined target hydraulic pressure. Then, the basic target flow rate is corrected by the feedback correction term to calculate the corrected target flow rate, and the variable mechanism is controlled so that the actual discharge flow rate becomes equal to the corrected target flow rate. Control device. The control device for an internal combustion engine according to claim 1, wherein the control unit controls the variable mechanism so that the smaller the opening degree of the oil jet valve is, the smaller the discharge flow rate of the oil pump is.

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